/*
    * mstp.c      State machines from IEEE 802.1Q-2005
    *
    *  This program is free software; you can redistribute it and/or
    *  modify it under the terms of the GNU General Public License
    *  as published by the Free Software Foundation; either version
    *  2 of the License, or (at your option) any later version.
    *
    * Authors: Vitalii Demianets <dvitasgs@gmail.com>
   */
  
  /* NOTE: The standard messes up Hello_Time timer management.
   * The portTimes and msgTimes structures have it, while
   * designatedTimes, rootTimes and BridgeTimes do not!
   * And there are places, where standard says:
   * "portTimes = designatedTimes" (13.32)
   * "rootTimes = portTimes" (13.26.23)
   * ---- Bad IEEE! ----
   * For now I decide: All structures will hold Hello_Time,
   * because in 802.1D they do.
   * Besides, it is necessary for compatibility with old STP implementations.
   */
  
  /* 802.1Q-2005 does not define but widely use variable name newInfoXst.
   * From the 802.1s I can guess that it means:
   *   - "newInfo" when tree is CIST;
   *   - "newInfoMsti" when tree is not CIST (is MSTI).
   * But that is only a guess and I could be wrong here ;)
   */
  
  /* Important coding convention:
   *   All functions that have dry_run argument must follow the
   *   return value convention:
   *      They should return true if state change detected during dry run.
   *      Otherwise (!dry_run || !state_change) they return false.
   */
  
  #include <config.h>
  
  #include <string.h>
  #include <netinet/in.h>
  #include <linux/if_bridge.h>
  #include <asm/byteorder.h>
  #include <time.h>
  #include <sys/time.h>
  
  #include "mstp.h"
  #include "log.h"
  #include "driver.h"
  
  static void PTSM_tick(port_t *prt);
  static bool TCSM_run(per_tree_port_t *ptp, bool dry_run);
  static void BDSM_begin(port_t *prt);
  static void br_state_machines_begin(bridge_t *br);
  static void prt_state_machines_begin(port_t *prt);
  static void tree_state_machines_begin(tree_t *tree);
  static void br_state_machines_run(bridge_t *br);
  static void updtbrAssuRcvdInfoWhile(port_t *prt);
  
  #define FOREACH_PORT_IN_BRIDGE(port, bridge) \
      list_for_each_entry((port), &(bridge)->ports, br_list)
  #define FOREACH_TREE_IN_BRIDGE(tree, bridge) \
      list_for_each_entry((tree), &(bridge)->trees, bridge_list)
  #define FOREACH_PTP_IN_TREE(ptp, tree) \
      list_for_each_entry((ptp), &(tree)->ports, tree_list)
  #define FOREACH_PTP_IN_PORT(ptp, port) \
      list_for_each_entry((ptp), &(port)->trees, port_list)
  
  /* 17.20.11 of 802.1D */
  #define rstpVersion(br) ((br)->ForceProtocolVersion >= protoRSTP)
  /* Bridge assurance is operational only when NetworkPort type is configured
   * and the operation status is pointToPoint and version is RSTP/MSTP
   */
  #define assurancePort(prt) ((prt)->NetworkPort && (prt)->operPointToPointMAC \
                              && (prt)->sendRSTP)
  /*
   * Recalculate configuration digest. (13.7)
   */
  static void RecalcConfigDigest(bridge_t *br)
  {
      __be16 vid2mstid[MAX_VID + 2];
      unsigned char mstp_key[] = HMAC_KEY;
      int vid;
  
      vid2mstid[0] = vid2mstid[MAX_VID + 1] = 0;
      for(vid = 1; vid <= MAX_VID; ++vid)
          vid2mstid[vid] = br->fid2mstid[br->vid2fid[vid]];
  
      hmac_md5((void *)vid2mstid, sizeof(vid2mstid), mstp_key, sizeof(mstp_key),
               (caddr_t)br->MstConfigId.s.configuration_digest);
  }
  
  /*
   * 13.37.1 - Table 13-3
   */
  static __u32 compute_pcost(int speed)
  {
    /* speed is in MB/s*/
    if(speed > 0)
     return (speed < 20000000) ? 20000000 / speed : 1;
   else
     return MAX_PATH_COST;
 }
 
 static void bridge_default_internal_vars(bridge_t *br)
 {
     br->uptime = 0;
 }
 
 static void tree_default_internal_vars(tree_t *tree)
 {
     /* 12.8.1.1.3.(b,c,d) */
     tree->time_since_topology_change = 0;
     tree->topology_change_count = 0;
     tree->topology_change = false; /* since all tcWhile are initialized to 0 */
     strncpy(tree->topology_change_port, "None", IFNAMSIZ);
     strncpy(tree->last_topology_change_port, "None", IFNAMSIZ);
 
     /* The following are initialized in BEGIN state:
      *  - rootPortId, rootPriority, rootTimes: in Port Role Selection SM
      */
 }
 
 static void port_default_internal_vars(port_t *prt)
 {
     prt->infoInternal = false;
     prt->rcvdInternal = false;
     prt->rcvdTcAck = false;
     prt->rcvdTcn = false;
     assign(prt->rapidAgeingWhile, 0u);
     assign(prt->brAssuRcvdInfoWhile, 0u);
     prt->BaInconsistent = false;
     prt->num_rx_bpdu_filtered = 0;
     prt->num_rx_bpdu = 0;
     prt->num_rx_tcn = 0;
     prt->num_tx_bpdu = 0;
     prt->num_tx_tcn = 0;
     prt->num_trans_fwd = 0;
     prt->num_trans_blk = 0;
 
     /* The following are initialized in BEGIN state:
      * - mdelayWhile. mcheck, sendRSTP: in Port Protocol Migration SM
      * - helloWhen, newInfo, newInfoMsti, txCount: in Port Transmit SM
      * - edgeDelayWhile, rcvdBpdu, rcvdRSTP, rcvdSTP : in Port Receive SM
      * - operEdge: in Bridge Detection SM
      * - tcAck: in Topology Change SM
      */
 }
 
 static void ptp_default_internal_vars(per_tree_port_t *ptp)
 {
     ptp->rcvdTc = false;
     ptp->tcProp = false;
     ptp->updtInfo = false;
     ptp->master = false; /* 13.24.5 */
     ptp->disputed = false;
     assign(ptp->rcvdInfo, (port_info_t)0);
     ptp->mastered = false;
     memset(&ptp->msgPriority, 0, sizeof(ptp->msgPriority));
     memset(&ptp->msgTimes, 0, sizeof(ptp->msgTimes));
 
     /* The following are initialized in BEGIN state:
      * - rcvdMsg: in Port Receive SM
      * - fdWhile, rrWhile, rbWhile, role, learn, forward,
      *   sync, synced, reRoot: in Port Role Transitions SM
      * - tcWhile, fdbFlush: Topology Change SM
      * - rcvdInfoWhile, proposed, proposing, agree, agreed,
      *   infoIs, reselect, selected: Port Information SM
      * - forwarding, learning: Port State Transition SM
      * - selectedRole, designatedPriority, designatedTimes: Port Role Selection SM
      */
 }
 
 static tree_t * create_tree(bridge_t *br, __u8 *macaddr, __be16 MSTID)
 {
     /* Initialize all fields except anchor */
     tree_t *tree = calloc(1, sizeof(*tree));
     if(!tree)
     {
         ERROR_BRNAME(br, "Out of memory");
         return NULL;
     }
     tree->bridge = br;
     tree->MSTID = MSTID;
     INIT_LIST_HEAD(&tree->ports);
 
     memcpy(tree->BridgeIdentifier.s.mac_address, macaddr, ETH_ALEN);
     /* 0x8000 = default bridge priority (17.14 of 802.1D) */
     tree->BridgeIdentifier.s.priority = __constant_cpu_to_be16(0x8000) | MSTID;
     assign(tree->BridgePriority.RootID, tree->BridgeIdentifier);
     assign(tree->BridgePriority.RRootID, tree->BridgeIdentifier);
     assign(tree->BridgePriority.DesignatedBridgeID, tree->BridgeIdentifier);
     /* 13.23.4 */
     assign(tree->BridgeTimes.remainingHops, br->MaxHops);
     assign(tree->BridgeTimes.Forward_Delay, br->Forward_Delay);
     assign(tree->BridgeTimes.Max_Age, br->Max_Age);
     assign(tree->BridgeTimes.Message_Age, (__u8)0);
     assign(tree->BridgeTimes.Hello_Time, br->Hello_Time);
 
     tree_default_internal_vars(tree);
 
     return tree;
 }
 
 static per_tree_port_t * create_ptp(tree_t *tree, port_t *prt)
 {
     /* Initialize all fields except anchors */
     per_tree_port_t *ptp = calloc(1, sizeof(*ptp));
     if(!ptp)
     {
         ERROR_PRTNAME(prt->bridge, prt, "Out of memory");
         return NULL;
     }
     ptp->port = prt;
     ptp->tree = tree;
     ptp->MSTID = tree->MSTID;
 
     ptp->state = BR_STATE_DISABLED;
     /* 0x80 = default port priority (17.14 of 802.1D) */
     ptp->portId = __constant_cpu_to_be16(0x8000) | prt->port_number;
     assign(ptp->AdminInternalPortPathCost, 0u);
     assign(ptp->InternalPortPathCost, compute_pcost(GET_PORT_SPEED(prt)));
     /* 802.1Q leaves portPriority and portTimes uninitialized */
     assign(ptp->portPriority, tree->BridgePriority);
     assign(ptp->portTimes, tree->BridgeTimes);
 
     ptp->calledFromFlushRoutine = false;
 
     ptp_default_internal_vars(ptp);
 
     return ptp;
 }
 
 /* External events */
 
 bool MSTP_IN_bridge_create(bridge_t *br, __u8 *macaddr)
 {
     tree_t *cist;
 
     if (!driver_create_bridge(br, macaddr))
         return false;
 
     /* Initialize all fields except sysdeps and anchor */
     INIT_LIST_HEAD(&br->ports);
     INIT_LIST_HEAD(&br->trees);
     br->bridgeEnabled = false;
     memset(br->vid2fid, 0, sizeof(br->vid2fid));
     memset(br->fid2mstid, 0, sizeof(br->fid2mstid));
     assign(br->MstConfigId.s.selector, (__u8)0);
     sprintf((char *)br->MstConfigId.s.configuration_name,
             "%02hhX%02hhX%02hhX%02hhX%02hhX%02hhX",
             macaddr[0], macaddr[1], macaddr[2],
             macaddr[3], macaddr[4], macaddr[5]);
     assign(br->MstConfigId.s.revision_level, __constant_cpu_to_be16(0));
     RecalcConfigDigest(br); /* set br->MstConfigId.s.configuration_digest */
     br->ForceProtocolVersion = protoRSTP;
     assign(br->MaxHops, (__u8)20);       /* 13.37.3 */
     assign(br->Forward_Delay, (__u8)15); /* 17.14 of 802.1D */
     assign(br->Max_Age, (__u8)20);       /* 17.14 of 802.1D */
     assign(br->Transmit_Hold_Count, 6u); /* 17.14 of 802.1D */
     assign(br->Migrate_Time, 3u); /* 17.14 of 802.1D */
     assign(br->Ageing_Time, 300u);/* 8.8.3 Table 8-3 */
     assign(br->Hello_Time, (__u8)2);     /* 17.14 of 802.1D */
 
     bridge_default_internal_vars(br);
 
     /* Create CIST */
     if(!(cist = create_tree(br, macaddr, 0)))
         return false;
     list_add_tail(&cist->bridge_list, &br->trees);
 
     return true;
 }
 
 bool MSTP_IN_port_create_and_add_tail(port_t *prt, __u16 portno)
 {
     tree_t *tree;
     per_tree_port_t *ptp, *nxt;
     bridge_t *br = prt->bridge;
 
     if (!driver_create_port(prt, portno))
         return false;
 
     /* Initialize all fields except sysdeps and bridge */
     INIT_LIST_HEAD(&prt->trees);
     prt->port_number = __cpu_to_be16(portno);
 
     assign(prt->AdminExternalPortPathCost, 0u);
     /* Default for operP2P is false because by default AdminP2P
      * says to auto-detect p2p state, and it is derived from duplex
      * and initially port is in down state and in this down state
      * duplex is set to false (half) */
     prt->AdminP2P = p2pAuto;
     prt->operPointToPointMAC = false;
     prt->portEnabled = false;
     prt->restrictedRole = false; /* 13.25.14 */
     prt->restrictedTcn = false; /* 13.25.15 */
     assign(prt->ExternalPortPathCost, MAX_PATH_COST); /* 13.37.1 */
     prt->AdminEdgePort = false; /* 13.25 */
     prt->AutoEdge = true;       /* 13.25 */
     prt->BpduGuardPort = false;
     prt->BpduGuardError = false;
     prt->NetworkPort = false;
     prt->dontTxmtBpdu = false;
     prt->bpduFilterPort = false;
     prt->deleted = false;
 
     port_default_internal_vars(prt);
 
     /* Create PerTreePort structures for all existing trees */
     FOREACH_TREE_IN_BRIDGE(tree, br)
     {
         if(!(ptp = create_ptp(tree, prt)))
         {
             /* Remove and free all previously created entries in port's list */
             list_for_each_entry_safe(ptp, nxt, &prt->trees, port_list)
             {
                 list_del(&ptp->port_list);
                 list_del(&ptp->tree_list);
                 free(ptp);
             }
             return false;
         }
         list_add_tail(&ptp->port_list, &prt->trees);
         list_add_tail(&ptp->tree_list, &tree->ports);
     }
 
     /* Add new port to the tail of the list in the bridge */
     /* NOTE: if one wants add port NOT to the tail of the list of ports,
      * one should revise above loop (FOREACH_TREE_IN_BRIDGE)
      * because it heavily depends on the fact that port is added to the tail.
      */
     list_add_tail(&prt->br_list, &br->ports);
 
     prt_state_machines_begin(prt);
     return true;
 }
 
 void MSTP_IN_delete_port(port_t *prt)
 {
     per_tree_port_t *ptp, *nxt;
     bridge_t *br = prt->bridge;
 
     driver_delete_port(prt);
 
     prt->deleted = true;
     if(prt->portEnabled)
     {
         prt->portEnabled = false;
         br_state_machines_run(br);
     }
 
     list_for_each_entry_safe(ptp, nxt, &prt->trees, port_list)
     {
         list_del(&ptp->port_list);
         list_del(&ptp->tree_list);
         free(ptp);
     }
 
     list_del(&prt->br_list);
     br_state_machines_run(br);
 }
 
 void MSTP_IN_delete_bridge(bridge_t *br)
 {
     tree_t *tree, *nxt_tree;
     port_t *prt, *nxt_prt;
 
     driver_delete_bridge(br);
 
     br->bridgeEnabled = false;
 
     /* We SHOULD first delete all ports and only THEN delete all tree_t
      * structures as the tree_t structure contains the head for the per-port
      * list of tree data (tree_t.ports).
      * If this list_head will be deleted before all the per_tree_ports
      * bad things will happen ;)
      */
 
     list_for_each_entry_safe(prt, nxt_prt, &br->ports, br_list)
     {
         MSTP_IN_delete_port(prt);
         free(prt);
     }
 
     list_for_each_entry_safe(tree, nxt_tree, &br->trees, bridge_list)
     {
         list_del(&tree->bridge_list);
         free(tree);
     }
 }
 
 void MSTP_IN_set_bridge_address(bridge_t *br, __u8 *macaddr)
 {
     tree_t *tree;
     bool changed = false;
 
     FOREACH_TREE_IN_BRIDGE(tree, br)
     {
         if(0 == memcmp(tree->BridgeIdentifier.s.mac_address, macaddr, ETH_ALEN))
             continue;
         changed = true;
         memcpy(tree->BridgeIdentifier.s.mac_address, macaddr, ETH_ALEN);
         tree->BridgePriority.RootID = tree->BridgePriority.RRootID =
             tree->BridgePriority.DesignatedBridgeID = tree->BridgeIdentifier;
     }
 
     if(changed)
         br_state_machines_begin(br);
 }
 
 void MSTP_IN_set_bridge_enable(bridge_t *br, bool up)
 {
     port_t *prt;
     per_tree_port_t *ptp;
     tree_t *tree;
 
     if(br->bridgeEnabled == up)
         return;
     br->bridgeEnabled = up;
 
     /* Reset all internal states and variables,
      * except those which are user-configurable */
     bridge_default_internal_vars(br);
     FOREACH_TREE_IN_BRIDGE(tree, br)
     {
         tree_default_internal_vars(tree);
     }
     FOREACH_PORT_IN_BRIDGE(prt, br)
     {
         /* NOTE: Don't check prt->deleted here, as it is imposible condition */
         /* NOTE: In the port_default_internal_vars() rapidAgeingWhile will be
          *  reset, so we should stop rapid ageing procedure here.
          */
         if(prt->rapidAgeingWhile)
         {
             MSTP_OUT_set_ageing_time(prt, br->Ageing_Time);
         }
         port_default_internal_vars(prt);
         FOREACH_PTP_IN_PORT(ptp, prt)
         {
             if(BR_STATE_DISABLED != ptp->state)
             {
                 MSTP_OUT_set_state(ptp, BR_STATE_DISABLED);
             }
             ptp_default_internal_vars(ptp);
         }
     }
     br_state_machines_begin(br);
 }
 
 void MSTP_IN_set_port_enable(port_t *prt, bool up, int speed, int duplex)
 {
     __u32 computed_pcost, new_ExternalPathCost, new_InternalPathCost;
     per_tree_port_t *ptp;
     bool new_p2p;
     bool changed = false;
 
     if(up)
     {
         computed_pcost = compute_pcost(speed);
         new_ExternalPathCost = (0 == prt->AdminExternalPortPathCost) ?
                                  computed_pcost
                                : prt->AdminExternalPortPathCost;
         if(prt->ExternalPortPathCost != new_ExternalPathCost)
         {
             assign(prt->ExternalPortPathCost, new_ExternalPathCost);
             changed = true;
         }
         FOREACH_PTP_IN_PORT(ptp, prt)
         {
             new_InternalPathCost = (0 == ptp->AdminInternalPortPathCost) ?
                                     computed_pcost
                                    : ptp->AdminInternalPortPathCost;
             if(ptp->InternalPortPathCost != new_InternalPathCost)
             {
                 assign(ptp->InternalPortPathCost, new_InternalPathCost);
                 changed = true;
             }
         }
 
         switch(prt->AdminP2P)
         {
             case p2pForceTrue:
                 new_p2p = true;
                 break;
             case p2pForceFalse:
                 new_p2p = false;
                 break;
             case p2pAuto:
             default:
                 new_p2p = !!duplex;
                 break;
         }
         if(prt->operPointToPointMAC != new_p2p)
         {
             prt->operPointToPointMAC = new_p2p;
             changed = true;
         }
 
         if(!prt->portEnabled)
         {
             prt->portEnabled = true;
             prt->BpduGuardError = false;
             prt->BaInconsistent = false;
             prt->num_rx_bpdu_filtered = 0;
             prt->num_rx_bpdu = 0;
             prt->num_rx_tcn = 0;
             prt->num_tx_bpdu = 0;
             prt->num_tx_tcn = 0;
             changed = true;
             /* When port is enabled, initialize bridge assurance timer,
              * so that enough time is given before port is put in
              * inconsistent state.
              */
             updtbrAssuRcvdInfoWhile(prt);
         }
     }
     else
     {
         if(prt->portEnabled)
         {
             prt->portEnabled = false;
             changed = true;
         }
     }
 
     if(changed)
         br_state_machines_run(prt->bridge);
 }
 
 void MSTP_IN_one_second(bridge_t *br)
 {
     port_t *prt;
     tree_t *tree;
 
     ++(br->uptime);
 
     if(!br->bridgeEnabled)
         return;
 
     FOREACH_TREE_IN_BRIDGE(tree, br)
         if(!(tree->topology_change))
             ++(tree->time_since_topology_change);
 
     FOREACH_PORT_IN_BRIDGE(prt, br)
     {
         PTSM_tick(prt);
         /* support for rapid ageing */
         if(prt->rapidAgeingWhile)
         {
             if((--(prt->rapidAgeingWhile)) == 0)
             {
                 if(!prt->deleted)
                     MSTP_OUT_set_ageing_time(prt, br->Ageing_Time);
             }
         }
     }
 
     br_state_machines_run(br);
 }
 
 void MSTP_IN_all_fids_flushed(per_tree_port_t *ptp)
 {
     bridge_t *br = ptp->port->bridge;
     ptp->fdbFlush = false;
     if(!br->bridgeEnabled)
         return;
     if(!ptp->calledFromFlushRoutine)
     {
         TCSM_run(ptp, false /* actual run */);
         br_state_machines_run(br);
     }
 }
 
 /* NOTE: bpdu pointer is unaligned, but it works because
  * bpdu_t is packed. Don't try to cast bpdu to non-packed type ;)
  */
 void MSTP_IN_rx_bpdu(port_t *prt, bpdu_t *bpdu, int size)
 {
     int mstis_size;
     bridge_t *br = prt->bridge;
 
     ++(prt->num_rx_bpdu);
 
     if(prt->BpduGuardPort)
     {
         prt->BpduGuardError = true;
         ERROR_PRTNAME(br, prt,
                       "Received BPDU on BPDU Guarded Port - Port Down");
         MSTP_OUT_shutdown_port(prt);
         return;
     }
 
     if(prt->bpduFilterPort)
     {
         LOG_PRTNAME(br, prt,
                    "Received BPDU on BPDU Filtered Port - discarded");
         ++(prt->num_rx_bpdu_filtered);
         return;
     }
 
     if(!br->bridgeEnabled)
     {
         INFO_PRTNAME(br, prt, "Received BPDU while bridge is disabled");
         return;
     }
 
     if(prt->rcvdBpdu)
     {
         ERROR_PRTNAME(br, prt, "Port hasn't processed previous BPDU");
         return;
     }
 
     /* 14.4 Validation */
     if((TCN_BPDU_SIZE > size) || (0 != bpdu->protocolIdentifier))
     {
 bpdu_validation_failed:
         INFO_PRTNAME(br, prt, "BPDU validation failed");
         return;
     }
     switch(bpdu->bpduType)
     {
         case bpduTypeTCN:
             /* 14.4.b) */
             /* Valid TCN BPDU */
             bpdu->protocolVersion = protoSTP;
             LOG_PRTNAME(br, prt, "received TCN BPDU");
             break;
         case bpduTypeConfig:
             /* 14.4.a) */
             if(CONFIG_BPDU_SIZE > size)
                 goto bpdu_validation_failed;
             /* Valid Config BPDU */
             bpdu->protocolVersion = protoSTP;
             LOG_PRTNAME(br, prt, "received Config BPDU%s",
                         (bpdu->flags & (1 << offsetTc)) ? ", tcFlag" : ""
                        );
             break;
         case bpduTypeRST:
             if(protoRSTP == bpdu->protocolVersion)
             { /* 14.4.c) */
                 if(RST_BPDU_SIZE > size)
                     goto bpdu_validation_failed;
                 /* Valid RST BPDU */
                 /* bpdu->protocolVersion = protoRSTP; */
                 LOG_PRTNAME(br, prt, "received RST BPDU%s",
                             (bpdu->flags & (1 << offsetTc)) ? ", tcFlag" : ""
                            );
                 break;
             }
             if(protoMSTP > bpdu->protocolVersion)
                 goto bpdu_validation_failed;
             /* Yes, 802.1Q-2005 says here to check if it contains
              * "35 or more octets", not 36! (see 14.4.d).1) )
              * That's why I check size against CONFIG_BPDU_SIZE
              * and not RST_BPDU_SIZE.
              */
             if(CONFIG_BPDU_SIZE > size)
                 goto bpdu_validation_failed;
             mstis_size = __be16_to_cpu(bpdu->version3_len)
                          - MST_BPDU_VER3LEN_WO_MSTI_MSGS;
             if((MST_BPDU_SIZE_WO_MSTI_MSGS > size) || (0 != bpdu->version1_len)
                || (0 > mstis_size)
                || ((MAX_STANDARD_MSTIS * sizeof(msti_configuration_message_t))
                    < mstis_size)
                || (0 != (mstis_size % sizeof(msti_configuration_message_t)))
               )
             { /* 14.4.d) */
                 /* Valid RST BPDU */
                 bpdu->protocolVersion = protoRSTP;
                 LOG_PRTNAME(br, prt, "received RST BPDU");
                 break;
             }
             /* 14.4.e) */
             /* Valid MST BPDU */
             bpdu->protocolVersion = protoMSTP;
             prt->rcvdBpduNumOfMstis = mstis_size
                                       / sizeof(msti_configuration_message_t);
             LOG_PRTNAME(br, prt, "received MST BPDU%s with %d MSTIs",
                         (bpdu->flags & (1 << offsetTc)) ? ", tcFlag" : "",
                         prt->rcvdBpduNumOfMstis
                        );
             break;
         default:
             goto bpdu_validation_failed;
     }
 
     if((protoSTP == bpdu->protocolVersion) && (bpduTypeTCN == bpdu->bpduType))
     {
         ++(prt->num_rx_tcn);
     }
     else
     {
         if(bpdu->flags & (1 << offsetTc))
             ++(prt->num_rx_tcn);
     }
 
     assign(prt->rcvdBpduData, *bpdu);
     prt->rcvdBpdu = true;
 
     /* Reset bridge assurance on receipt of valid BPDU */
     if(prt->BaInconsistent)
     {
         prt->BaInconsistent = false;
         INFO_PRTNAME(br, prt, "Clear Bridge assurance inconsistency");
     }
     updtbrAssuRcvdInfoWhile(prt);
 
     br_state_machines_run(br);
 }
 
 /* 12.8.1.1 Read CIST Bridge Protocol Parameters */
 void MSTP_IN_get_cist_bridge_status(bridge_t *br, CIST_BridgeStatus *status)
 {
     tree_t *cist = GET_CIST_TREE(br);
     assign(status->bridge_id, cist->BridgeIdentifier);
     assign(status->time_since_topology_change,
            cist->time_since_topology_change);
     assign(status->topology_change_count, cist->topology_change_count);
     status->topology_change = cist->topology_change;
     strncpy(status->topology_change_port, cist->topology_change_port,
             IFNAMSIZ);
     strncpy(status->last_topology_change_port, cist->last_topology_change_port,
             IFNAMSIZ);
     assign(status->designated_root, cist->rootPriority.RootID);
     assign(status->root_path_cost,
            __be32_to_cpu(cist->rootPriority.ExtRootPathCost));
     assign(status->regional_root, cist->rootPriority.RRootID);
     assign(status->internal_path_cost,
            __be32_to_cpu(cist->rootPriority.IntRootPathCost));
     assign(status->root_port_id, cist->rootPortId);
     assign(status->root_max_age, cist->rootTimes.Max_Age);
     assign(status->root_forward_delay, cist->rootTimes.Forward_Delay);
     assign(status->bridge_max_age, br->Max_Age);
     assign(status->bridge_forward_delay, br->Forward_Delay);
     assign(status->max_hops, br->MaxHops);
     assign(status->tx_hold_count, br->Transmit_Hold_Count);
     status->protocol_version = br->ForceProtocolVersion;
     status->enabled = br->bridgeEnabled;
     assign(status->bridge_hello_time, br->Hello_Time);
     assign(status->Ageing_Time, br->Ageing_Time);
 }
 
 /* 12.8.1.2 Read MSTI Bridge Protocol Parameters */
 void MSTP_IN_get_msti_bridge_status(tree_t *tree, MSTI_BridgeStatus *status)
 {
     assign(status->bridge_id, tree->BridgeIdentifier);
     assign(status->time_since_topology_change,
            tree->time_since_topology_change);
     assign(status->topology_change_count, tree->topology_change_count);
     status->topology_change = tree->topology_change;
     strncpy(status->topology_change_port, tree->topology_change_port,
             IFNAMSIZ);
     strncpy(status->last_topology_change_port, tree->last_topology_change_port,
             IFNAMSIZ);
     assign(status->regional_root, tree->rootPriority.RRootID);
     assign(status->internal_path_cost,
            __be32_to_cpu(tree->rootPriority.IntRootPathCost));
     assign(status->root_port_id, tree->rootPortId);
 }
 
 /* 12.8.1.3 Set CIST Bridge Protocol Parameters */
 int MSTP_IN_set_cist_bridge_config(bridge_t *br, CIST_BridgeConfig *cfg)
 {
     bool changed, changedBridgeTimes, init;
     int r = 0;
     __u8 new_forward_delay, new_max_age;
     tree_t *tree;
     port_t *prt;
     per_tree_port_t *ptp;
 
     /* Firstly, validation */
     if(cfg->set_bridge_max_age)
     {
         new_max_age = cfg->bridge_max_age;
         if((6 > new_max_age) || (40 < new_max_age))
         {
             ERROR_BRNAME(br,
                 "Bridge Max Age must be between 6 and 40 seconds");
             r = -1;
         }
     }
     else
         new_max_age = br->Max_Age;
 
     if(cfg->set_bridge_forward_delay)
     {
         new_forward_delay = cfg->bridge_forward_delay;
         if((4 > new_forward_delay) || (30 < new_forward_delay))
         {
             ERROR_BRNAME(br,
                 "Bridge Forward Delay must be between 4 and 30 seconds");
             r = -1;
         }
     }
     else
         new_forward_delay = br->Forward_Delay;
 
     if(cfg->set_bridge_max_age || cfg->set_bridge_forward_delay)
     {
         if((2 * (new_forward_delay - 1)) < new_max_age)
         {
             ERROR_BRNAME(br, "Configured Bridge Times don't meet "
                 "2 * (Bridge Foward Delay - 1 second) >= Bridge Max Age");
             r = -1;
         }
     }
 
     if(cfg->set_protocol_version)
     {
         switch(cfg->protocol_version)
         {
             case protoSTP:
             case protoRSTP:
             case protoMSTP:
                 break;
             default:
                 ERROR_BRNAME(br, "Bad protocol version (%d)",
                              cfg->protocol_version);
                 r = -1;
         }
     }
 
     if(cfg->set_tx_hold_count)
     {
         if((1 > cfg->tx_hold_count) || (10 < cfg->tx_hold_count))
         {
             ERROR_BRNAME(br,
                 "Transmit Hold Count must be between 1 and 10 seconds");
             r = -1;
         }
     }
 
     if(cfg->set_max_hops)
     {
         if((6 > cfg->max_hops) || (40 < cfg->max_hops))
         {
             ERROR_BRNAME(br, "Bridge Max Hops must be between 6 and 40");
             r = -1;
         }
     }
 
     if(cfg->set_bridge_hello_time)
     {
         if((1 > cfg->bridge_hello_time) || (10 < cfg->bridge_hello_time))
         {
             ERROR_BRNAME(br, "Bridge Hello Time must be between 1 and 10");
             r = -1;
         }
     }
 
     if(cfg->set_bridge_ageing_time)
     {
         if((10 > cfg->bridge_ageing_time)||(1000000 < cfg->bridge_ageing_time))
         {
             ERROR_BRNAME(br,
                 "Bridge Ageing Time must be between 10 and 1000000 seconds");
             r = -1;
         }
     }
 
     if(r)
         return r;
 
     /* Secondly, do set */
     changed = changedBridgeTimes = init = false;
 
     if(cfg->set_bridge_max_age || cfg->set_bridge_forward_delay)
     {
         if(cmp(new_max_age, !=, br->Max_Age)
            || cmp(new_forward_delay, !=, br->Forward_Delay)
           )
         {
             assign(br->Max_Age, new_max_age);
             assign(br->Forward_Delay, new_forward_delay);
             changed = changedBridgeTimes = true;
         }
     }
 
     if((cfg->set_protocol_version)
        && (cfg->protocol_version != br->ForceProtocolVersion)
       )
     {
         br->ForceProtocolVersion = cfg->protocol_version;
         changed = init = true;
     }
 
     if(cfg->set_tx_hold_count)
     {
         if(cfg->tx_hold_count != br->Transmit_Hold_Count)
         {
             assign(br->Transmit_Hold_Count, cfg->tx_hold_count);
             FOREACH_PORT_IN_BRIDGE(prt, br)
                 assign(prt->txCount, 0u);
             changed = true;
         }
     }
 
     if(cfg->set_max_hops)
     {
         if(cfg->max_hops != br->MaxHops)
         {
             assign(br->MaxHops, cfg->max_hops);
             changed = changedBridgeTimes = true;
         }
     }
 
     if(cfg->set_bridge_hello_time)
     {
         if(cfg->bridge_hello_time != br->Hello_Time)
         {
             INFO_BRNAME(br, "bridge hello_time new=%hhu, old=%hhu",
                         cfg->bridge_hello_time, br->Hello_Time);
             assign(br->Hello_Time, cfg->bridge_hello_time);
             changed = changedBridgeTimes = true;
         }
     }
 
     if(cfg->set_bridge_ageing_time)
     {
         if(cfg->bridge_ageing_time != br->Ageing_Time)
         {
             INFO_BRNAME(br, "bridge ageing_time new=%u, old=%u",
                         cfg->bridge_ageing_time, br->Ageing_Time);
             assign(br->Ageing_Time, cfg->bridge_ageing_time);
         }
     }
 
     /* Thirdly, finalize changes */
     if(changedBridgeTimes)
     {
         FOREACH_TREE_IN_BRIDGE(tree, br)
         {
             assign(tree->BridgeTimes.remainingHops, br->MaxHops);
             assign(tree->BridgeTimes.Forward_Delay, br->Forward_Delay);
             assign(tree->BridgeTimes.Max_Age, br->Max_Age);
             assign(tree->BridgeTimes.Hello_Time, br->Hello_Time);
         /* Comment found in rstpd by Srinivas Aji:
          * Do this for any change in BridgeTimes.
          * Otherwise we fail UNH rstp.op_D test 3.2 since when administratively
          * setting BridgeForwardDelay, etc, the values don't propagate from
          * rootTimes to designatedTimes immediately without this change.
          */
             FOREACH_PTP_IN_TREE(ptp, tree)
             {
                 ptp->selected = false;
                 ptp->reselect = true;
                 /* TODO: change this when Hello_Time will be configurable
                  *   per-port. For now, copy Bridge's Hello_Time
                  *   to the port's Hello_Time.
                  */
                 assign(ptp->portTimes.Hello_Time, br->Hello_Time);
             }
         }
     }
 
     if(changed && br->bridgeEnabled)
     {
         if(init)
             br_state_machines_begin(br);
         else
             br_state_machines_run(br);
     }
 
     return 0;
 }
 
 /* 12.8.1.4 Set MSTI Bridge Protocol Parameters */
 int MSTP_IN_set_msti_bridge_config(tree_t *tree, __u8 bridge_priority)
 {
     per_tree_port_t *ptp;
     __u8 valuePri;
 
     if(15 < bridge_priority)
     {
         ERROR_BRNAME(tree->bridge,
                      "MSTI %hu: Bridge Priority must be between 0 and 15",
                      __be16_to_cpu(tree->MSTID));
         return -1;
     }
 
     valuePri = bridge_priority << 4;
     if(GET_PRIORITY_FROM_IDENTIFIER(tree->BridgeIdentifier) == valuePri)
         return 0;
     SET_PRIORITY_IN_IDENTIFIER(valuePri, tree->BridgeIdentifier);
     tree->BridgePriority.RootID = tree->BridgePriority.RRootID =
         tree->BridgePriority.DesignatedBridgeID = tree->BridgeIdentifier;
     /* 12.8.1.4.4 do not require reselect, but I think it is needed,
      *  because 12.8.1.3.4.c) requires it */
     FOREACH_PTP_IN_TREE(ptp, tree)
     {
         ptp->selected = false;
         ptp->reselect = true;
     }
     return 0;
 }
 
 /* 12.8.2.1 Read CIST Port Parameters */
 void MSTP_IN_get_cist_port_status(port_t *prt, CIST_PortStatus *status)
 {
     per_tree_port_t *cist = GET_CIST_PTP_FROM_PORT(prt);
     /* 12.8.2.2.3 b) */
     status->uptime = (signed int)((prt->bridge)->uptime)
                      - (signed int)(cist->start_time);
     status->state = cist->state;
     assign(status->port_id, cist->portId);
     assign(status->admin_external_port_path_cost,
            prt->AdminExternalPortPathCost);
     assign(status->external_port_path_cost, prt->ExternalPortPathCost);
     assign(status->designated_root, cist->portPriority.RootID);
     assign(status->designated_external_cost,
            __be32_to_cpu(cist->portPriority.ExtRootPathCost));
     assign(status->designated_bridge, cist->portPriority.DesignatedBridgeID);
     assign(status->designated_port, cist->portPriority.DesignatedPortID);
     assign(status->designated_regional_root, cist->portPriority.RRootID);
     assign(status->designated_internal_cost,
            __be32_to_cpu(cist->portPriority.IntRootPathCost));
     status->tc_ack = prt->tcAck;
     assign(status->port_hello_time, cist->portTimes.Hello_Time);
     status->admin_edge_port = prt->AdminEdgePort;
     status->auto_edge_port = prt->AutoEdge;
     status->oper_edge_port = prt->operEdge;
     status->enabled = prt->portEnabled;
     status->admin_p2p = prt->AdminP2P;
     status->oper_p2p = prt->operPointToPointMAC;
     status->restricted_role = prt->restrictedRole;
     status->restricted_tcn = prt->restrictedTcn;
     status->role = cist->role;
     status->disputed = cist->disputed;
     assign(status->admin_internal_port_path_cost,
            cist->AdminInternalPortPathCost);
     assign(status->internal_port_path_cost, cist->InternalPortPathCost);
     status->bpdu_guard_port = prt->BpduGuardPort;
     status->bpdu_guard_error = prt->BpduGuardError;
     status->network_port = prt->NetworkPort;
     status->ba_inconsistent = prt->BaInconsistent;
     status->bpdu_filter_port = prt->bpduFilterPort;
     status->num_rx_bpdu_filtered = prt->num_rx_bpdu_filtered;
     status->num_rx_bpdu = prt->num_rx_bpdu;
     status->num_rx_tcn = prt->num_rx_tcn;
     status->num_tx_bpdu = prt->num_tx_bpdu;
     status->num_tx_tcn = prt->num_tx_tcn;
     status->num_trans_fwd = prt->num_trans_fwd;
     status->num_trans_blk = prt->num_trans_blk;
     status->rcvdBpdu = prt->rcvdBpdu;
     status->rcvdRSTP = prt->rcvdRSTP;
     status->rcvdSTP = prt->rcvdSTP;
     status->rcvdTcAck = prt->rcvdTcAck;
     status->rcvdTcn = prt->rcvdTcn;
     status->sendRSTP = prt->sendRSTP;
 }
 
 /* 12.8.2.2 Read MSTI Port Parameters */
 void MSTP_IN_get_msti_port_status(per_tree_port_t *ptp,
                                   MSTI_PortStatus *status)
 {
     status->uptime = (signed int)((ptp->port->bridge)->uptime)
                      - (signed int)(ptp->start_time);
     status->state = ptp->state;
     assign(status->port_id, ptp->portId);
     assign(status->admin_internal_port_path_cost,
            ptp->AdminInternalPortPathCost);
     assign(status->internal_port_path_cost, ptp->InternalPortPathCost);
     assign(status->designated_regional_root, ptp->portPriority.RRootID);
     assign(status->designated_internal_cost,
            __be32_to_cpu(ptp->portPriority.IntRootPathCost));
     assign(status->designated_bridge, ptp->portPriority.DesignatedBridgeID);
     assign(status->designated_port, ptp->portPriority.DesignatedPortID);
     status->role = ptp->role;
     status->disputed = ptp->disputed;
 }
 
 /* 12.8.2.3 Set CIST port parameters */
 int MSTP_IN_set_cist_port_config(port_t *prt, CIST_PortConfig *cfg)
 {
     bool changed;
     __u32 new_ExternalPathCost;
     bool new_p2p;
     per_tree_port_t *cist;
     bridge_t *br = prt->bridge;
 
     /* Firstly, validation */
     if(cfg->set_admin_p2p)
     {
         switch(cfg->admin_p2p)
         {
             case p2pAuto:
             case p2pForceTrue:
             case p2pForceFalse:
                 break;
             default:
                 cfg->admin_p2p = p2pAuto;
         }
     }
 
     /* Secondly, do set */
     changed = false;
 
     if(cfg->set_admin_external_port_path_cost)
     {
         prt->AdminExternalPortPathCost = cfg->admin_external_port_path_cost;
         new_ExternalPathCost = (0 == prt->AdminExternalPortPathCost) ?
                                  compute_pcost(GET_PORT_SPEED(prt))
                                : prt->AdminExternalPortPathCost;
         if(prt->ExternalPortPathCost != new_ExternalPathCost)
         {
             assign(prt->ExternalPortPathCost, new_ExternalPathCost);
             changed = true;
             /* 12.8.2.3.4 */
             cist = GET_CIST_PTP_FROM_PORT(prt);
             cist->selected = false;
             cist->reselect = true;
         }
     }
 
     if(cfg->set_admin_p2p)
     {
         prt->AdminP2P = cfg->admin_p2p;
         switch(prt->AdminP2P)
         {
             case p2pForceTrue:
                 new_p2p = true;
                 break;
             case p2pForceFalse:
                 new_p2p = false;
                 break;
             case p2pAuto:
             default:
                 new_p2p = !!GET_PORT_DUPLEX(prt);
                 break;
         }
         if(prt->operPointToPointMAC != new_p2p)
         {
             prt->operPointToPointMAC = new_p2p;
             changed = true;
         }
     }
 
     if(cfg->set_admin_edge_port)
     {
         if(prt->AdminEdgePort != cfg->admin_edge_port)
         {
             prt->AdminEdgePort = cfg->admin_edge_port;
             BDSM_begin(prt);
             changed = true;
         }
     }
 
     if(cfg->set_auto_edge_port)
     {
         if(prt->AutoEdge != cfg->auto_edge_port)
         {
             prt->AutoEdge = cfg->auto_edge_port;
             changed = true;
         }
     }
 
     if(cfg->set_restricted_role)
     {
         if(prt->restrictedRole != cfg->restricted_role)
         {
             prt->restrictedRole = cfg->restricted_role;
             changed = true;
         }
     }
 
     if(cfg->set_restricted_tcn)
     {
         if(prt->restrictedTcn != cfg->restricted_tcn)
         {
             prt->restrictedTcn = cfg->restricted_tcn;
             changed = true;
         }
     }
 
     if(cfg->set_bpdu_guard_port)
     {
         if(prt->BpduGuardPort != cfg->bpdu_guard_port)
         {
             prt->BpduGuardPort = cfg->bpdu_guard_port;
             INFO_PRTNAME(br, prt,"BpduGuardPort new=%d", prt->BpduGuardPort);
         }
     }
 
     if(cfg->set_network_port)
     {
         if(prt->NetworkPort != cfg->network_port)
         {
             prt->NetworkPort = cfg->network_port;
             INFO_PRTNAME(br, prt, "NetworkPort new=%d", prt->NetworkPort);
             /* When Network port config is removed and bridge assurance
              * inconsistency is set, clear the inconsistency.
              */
             if(!prt->NetworkPort && prt->BaInconsistent)
             {
                 prt->BaInconsistent = false;
                 INFO_PRTNAME(br, prt, "Clear Bridge assurance inconsistency");
             }
             changed = true;
         }
     }
 
     if(cfg->set_dont_txmt)
     {
         if(prt->dontTxmtBpdu != cfg->dont_txmt)
         {
             prt->dontTxmtBpdu = cfg->dont_txmt;
             INFO_PRTNAME(br, prt, "donttxmt new=%d", prt->dontTxmtBpdu);
         }
     }
 
     if(cfg->set_bpdu_filter_port)
     {
         if (prt->bpduFilterPort != cfg->bpdu_filter_port)
         {
             prt->bpduFilterPort = cfg->bpdu_filter_port;
             prt->num_rx_bpdu_filtered = 0;
             INFO_PRTNAME(br, prt,"bpduFilterPort new=%d", prt->bpduFilterPort);
         }
     }
 
     if(changed && prt->portEnabled)
         br_state_machines_run(prt->bridge);
 
     return 0;
 }
 
 /* 12.8.2.4 Set MSTI port parameters */
 int MSTP_IN_set_msti_port_config(per_tree_port_t *ptp, MSTI_PortConfig *cfg)
 {
     __u8 valuePri;
     __u32 new_InternalPathCost;
     bool changed = false;
     port_t *prt = ptp->port;
     bridge_t *br = prt->bridge;
 
     if(cfg->set_port_priority)
     {
         if(15 < cfg->port_priority)
         {
             ERROR_MSTINAME(br, prt, ptp,
                            "Port Priority must be between 0 and 15");
             return -1;
         }
         valuePri = cfg->port_priority << 4;
         if(GET_PRIORITY_FROM_IDENTIFIER(ptp->portId) != valuePri)
         {
             SET_PRIORITY_IN_IDENTIFIER(valuePri, ptp->portId);
             changed = true;
         }
     }
 
     if(cfg->set_admin_internal_port_path_cost)
     {
         ptp->AdminInternalPortPathCost = cfg->admin_internal_port_path_cost;
         new_InternalPathCost = (0 == ptp->AdminInternalPortPathCost) ?
                                  compute_pcost(GET_PORT_SPEED(prt))
                                : ptp->AdminInternalPortPathCost;
         if(ptp->InternalPortPathCost != new_InternalPathCost)
         {
             assign(ptp->InternalPortPathCost, new_InternalPathCost);
             changed = true;
         }
     }
 
     if(changed && prt->portEnabled)
     {
         /* 12.8.2.4.4 */
         ptp->selected = false;
         ptp->reselect = true;
 
         br_state_machines_run(br);
     }
 
     return 0;
 }
 
 /* 12.8.2.5 Force BPDU Migration Check */
 int MSTP_IN_port_mcheck(port_t *prt)
 {
     bridge_t *br = prt->bridge;
     per_tree_port_t *cist = GET_CIST_PTP_FROM_PORT(prt);
 
     if(rstpVersion(br) && prt->portEnabled && br->bridgeEnabled)
     {
         prt->mcheck = true;
         cist->proposing = true;
         br_state_machines_run(br);
     }
 
     return 0;
 }
 
 /* 12.10.3.8 Set VID to FID allocation */
 bool MSTP_IN_set_vid2fid(bridge_t *br, __u16 vid, __u16 fid)
 {
     bool vid2mstid_changed;
 
     if((vid < 1) || (vid > MAX_VID) || (fid > MAX_FID))
     {
         ERROR_BRNAME(br, "Error allocating VID(%hu) to FID(%hu)", vid, fid);
         return false;
     }
 
     vid2mstid_changed =
         (br->fid2mstid[fid] != br->fid2mstid[br->vid2fid[vid]]);
     br->vid2fid[vid] = fid;
     if(vid2mstid_changed)
     {
         RecalcConfigDigest(br);
         br_state_machines_begin(br);
     }
 
     return true;
 }
 
 /* Set all VID-to-FID mappings at once */
 bool MSTP_IN_set_all_vids2fids(bridge_t *br, __u16 *vids2fids)
 {
     bool vid2mstid_changed;
     int vid;
 
     vid2mstid_changed = false;
     for(vid = 1; vid <= MAX_VID; ++vid)
     {
         if(vids2fids[vid] > MAX_FID)
         { /* Incorrect value == keep prev value */
             vids2fids[vid] = br->vid2fid[vid];
             continue;
         }
         if(br->fid2mstid[vids2fids[vid]] != br->fid2mstid[br->vid2fid[vid]])
             vid2mstid_changed = true;
     }
     memcpy(br->vid2fid, vids2fids, sizeof(br->vid2fid));
     if(vid2mstid_changed)
     {
         RecalcConfigDigest(br);
         br_state_machines_begin(br);
     }
 
     return true;
 }
 
 /* 12.12.2.2 Set FID to MSTID allocation */
 bool MSTP_IN_set_fid2mstid(bridge_t *br, __u16 fid, __u16 mstid)
 {
     tree_t *tree;
     __be16 MSTID;
     bool found;
     int vid;
 
     if(fid > MAX_FID)
     {
         ERROR_BRNAME(br, "Bad FID(%hu)", fid);
         return false;
     }
 
     MSTID = __cpu_to_be16(mstid);
     found = false;
     FOREACH_TREE_IN_BRIDGE(tree, br)
     {
         if(tree->MSTID == MSTID)
         {
             found = true;
             break;
         }
     }
     if(!found)
     {
         ERROR_BRNAME(br, "MSTID(%hu) not found", mstid);
         return false;
     }
 
     if(br->fid2mstid[fid] != MSTID)
     {
         br->fid2mstid[fid] = MSTID;
         /* check if there are VLANs using this FID */
         for(vid = 1; vid <= MAX_VID; ++vid)
         {
             if(br->vid2fid[vid] == fid)
             {
                 RecalcConfigDigest(br);
                 br_state_machines_begin(br);
                 break;
             }
         }
     }
 
     return true;
 }
 
 /* Set all FID-to-MSTID mappings at once */
 bool MSTP_IN_set_all_fids2mstids(bridge_t *br, __u16 *fids2mstids)
 {
     tree_t *tree;
     __be16 MSTID[MAX_FID + 1];
     bool found, vid2mstid_changed;
     int fid, vid;
     __be16 prev_vid2mstid[MAX_VID + 2];
 
     for(fid = 0; fid <= MAX_FID; ++fid)
     {
         if(fids2mstids[fid] > MAX_MSTID)
         { /* Incorrect value == keep prev value */
             fids2mstids[fid] = __be16_to_cpu(MSTID[fid] = br->fid2mstid[fid]);
         }
         else
             MSTID[fid] = __cpu_to_be16(fids2mstids[fid]);
         found = false;
         FOREACH_TREE_IN_BRIDGE(tree, br)
         {
             if(tree->MSTID == MSTID[fid])
             {
                 found = true;
                 break;
             }
         }
         if(!found)
         {
             ERROR_BRNAME(br,
                 "Error allocating FID(%hu) to MSTID(%hu): MSTID not found",
                 fid, fids2mstids[fid]);
             return false;
         }
     }
 
     for(vid = 1; vid <= MAX_VID; ++vid)
         prev_vid2mstid[vid] = br->fid2mstid[br->vid2fid[vid]];
     memcpy(br->fid2mstid, MSTID, sizeof(br->fid2mstid));
     vid2mstid_changed = false;
     for(vid = 1; vid <= MAX_VID; ++vid)
     {
         if(prev_vid2mstid[vid] != br->fid2mstid[br->vid2fid[vid]])
         {
             vid2mstid_changed = true;
             break;
         }
     }
     if(vid2mstid_changed)
     {
         RecalcConfigDigest(br);
         br_state_machines_begin(br);
     }
 
     return true;
 }
 
 /* 12.12.1.1 Read MSTI List */
 bool MSTP_IN_get_mstilist(bridge_t *br, int *num_mstis, __u16 *mstids)
 {
     tree_t *tree;
 
     *num_mstis = 0;
     FOREACH_TREE_IN_BRIDGE(tree, br)
     {
         mstids[*num_mstis] = __be16_to_cpu(tree->MSTID);
         /* Check for "<", not for "<=", as num_mstis include CIST */
         if(MAX_IMPLEMENTATION_MSTIS < ++(*num_mstis))
             break;
     }
 
     return true;
 }
 
 /* 12.12.1.2 Create MSTI */
 bool MSTP_IN_create_msti(bridge_t *br, __u16 mstid)
 {
     tree_t *tree, *tree_after, *new_tree;
     per_tree_port_t *ptp, *nxt, *ptp_after, *new_ptp;
     int num_of_mstis;
     __be16 MSTID;
 
     if((mstid < 1) || (mstid > MAX_MSTID))
     {
         ERROR_BRNAME(br, "Bad MSTID(%hu)", mstid);
         return false;
     }
 
     MSTID = __cpu_to_be16(mstid);
     /* Find place where to insert new MSTID.
      * Also check if such MSTID is already in the list.
      * Also count existing mstis.
      */
     tree_after = NULL;
     num_of_mstis = 0;
     FOREACH_TREE_IN_BRIDGE(tree, br)
     {
         if(tree->MSTID == MSTID)
         {
             INFO_BRNAME(br, "MSTID(%hu) is already in the list", mstid);
             return true; /* yes, it is success */
         }
         if(cmp(tree->MSTID, <, MSTID))
             tree_after = tree;
         ++num_of_mstis;
     }
     /* Sanity check */
     if(NULL == tree_after)
     {
         ERROR_BRNAME(br, "Can't add MSTID(%hu): no CIST in the list", mstid);
         return false;
     }
     /* End of Sanity check */
 
     /* Check for "<", not for "<=", as num_of_mstis include CIST */
     if(MAX_IMPLEMENTATION_MSTIS < num_of_mstis)
     {
         ERROR_BRNAME(br, "Can't add MSTID(%hu): maximum count(%u) reached",
                      mstid, MAX_IMPLEMENTATION_MSTIS);
         return false;
     }
 
     /* Create new tree and its list of PerTreePort structures */
     tree = GET_CIST_TREE(br);
     if(!(new_tree=create_tree(br,tree->BridgeIdentifier.s.mac_address,MSTID)))
         return false;
 
     FOREACH_PTP_IN_TREE(ptp_after, tree_after)
     {
         if(!(new_ptp = create_ptp(new_tree, ptp_after->port)))
         {
             /* Remove and free all previously created entries in tree's list */
             list_for_each_entry_safe(ptp, nxt, &new_tree->ports, tree_list)
             {
                 list_del(&ptp->port_list);
                 list_del(&ptp->tree_list);
                 free(ptp);
             }
             return false;
         }
         list_add(&new_ptp->port_list, &ptp_after->port_list);
         list_add_tail(&new_ptp->tree_list, &new_tree->ports);
     }
 
     list_add(&new_tree->bridge_list, &tree_after->bridge_list);
     /* There are no FIDs allocated to this MSTID, so VID-to-MSTID mapping
      *  did not change. So, no need in RecalcConfigDigest.
      * Just initialize state machines for this tree.
      */
     tree_state_machines_begin(new_tree);
     return true;
 }
 
 /* 12.12.1.3 Delete MSTI */
 bool MSTP_IN_delete_msti(bridge_t *br, __u16 mstid)
 {
     tree_t *tree;
     per_tree_port_t *ptp, *nxt;
     int fid;
     bool found;
     __be16 MSTID = __cpu_to_be16(mstid);
 
     if((mstid < 1) || (mstid > MAX_MSTID))
     {
         ERROR_BRNAME(br, "Bad MSTID(%hu)", mstid);
         return false;
     }
 
     /* Check if there are FIDs associated with this MSTID */
     for(fid = 0; fid <= MAX_FID; ++fid)
     {
         if(br->fid2mstid[fid] == MSTID)
         {
             ERROR_BRNAME(br,
                 "Can't delete MSTID(%hu): there are FIDs allocated to it",
                 mstid);
             return false;
         }
     }
 
     found = false;
     FOREACH_TREE_IN_BRIDGE(tree, br)
     {
         if(tree->MSTID == MSTID)
         {
             found = true;
             break;
         }
     }
     if(!found)
     {
         INFO_BRNAME(br, "MSTID(%hu) is not in the list", mstid);
         return true; /* yes, it is success */
     }
 
     list_del(&tree->bridge_list);
     list_for_each_entry_safe(ptp, nxt, &tree->ports, tree_list)
     {
         list_del(&ptp->port_list);
         list_del(&ptp->tree_list);
         free(ptp);
     }
     free(tree);
 
     /* There are no FIDs allocated to this MSTID, so VID-to-MSTID mapping
      *  did not change. So, no need in RecalcConfigDigest.
      * Give state machine a spare run, just for the case...
      */
     br_state_machines_run(br);
     return true;
 }
 
 /* 12.12.3.4 Set MST Configuration Identifier Elements */
 void MSTP_IN_set_mst_config_id(bridge_t *br, __u16 revision, __u8 *name)
 {
     __be16 valueRevision = __cpu_to_be16(revision);
     bool changed = (0 != strncmp((char *)name, (char *)br->MstConfigId.s.configuration_name,
                                  sizeof(br->MstConfigId.s.configuration_name))
                    )
                    || (valueRevision != br->MstConfigId.s.revision_level);
 
     if(changed)
     {
         assign(br->MstConfigId.s.revision_level, valueRevision);
         memset(br->MstConfigId.s.configuration_name, 0,
                sizeof(br->MstConfigId.s.configuration_name));
         strncpy((char *)br->MstConfigId.s.configuration_name, (char *)name,
                 sizeof(br->MstConfigId.s.configuration_name) - 1);
         br_state_machines_begin(br);
     }
 }
 
 /*
  * If hint_SetToYes == true, some tcWhile in this tree has non-zero value.
  * If hint_SetToYes == false, some tcWhile in this tree has just became zero,
  *  so we should check all other tcWhile's in this tree.
  */
 static void set_TopologyChange(tree_t *tree, bool hint_SetToYes, port_t *port)
 {
     per_tree_port_t *ptp;
     bool prev_tc_not_set = !tree->topology_change;
 
     if(hint_SetToYes)
     {
         tree->topology_change = true;
         tree->time_since_topology_change = 0;
         if(prev_tc_not_set)
             ++(tree->topology_change_count);
         strncpy(tree->topology_change_port, tree->last_topology_change_port,
                 IFNAMSIZ);
         strncpy(tree->last_topology_change_port, port->sysdeps.name, IFNAMSIZ);
         return;
     }
 
     /* Some tcWhile has just became zero. Check if we need reset
      * topology_change flag */
     if(prev_tc_not_set)
         return;
 
     tree->topology_change = false;
     FOREACH_PTP_IN_TREE(ptp, tree)
     {
         if(0 != ptp->tcWhile)
         {
             tree->topology_change = true;
             tree->time_since_topology_change = 0;
             return;
         }
     }
 }
 
 /* Helper functions, compare two priority vectors */
 static bool samePriorityAndTimers(port_priority_vector_t *vec1,
                                   port_priority_vector_t *vec2,
                                   times_t *time1,
                                   times_t *time2,
                                   bool cist)
 {
     if(cist)
     {
         if(cmp(time1->Forward_Delay, !=, time2->Forward_Delay))
             return false;
         if(cmp(time1->Max_Age, !=, time2->Max_Age))
             return false;
         if(cmp(time1->Message_Age, !=, time2->Message_Age))
             return false;
         if(cmp(time1->Hello_Time, !=, time2->Hello_Time))
             return false;
 
         if(cmp(vec1->RootID, !=, vec2->RootID))
             return false;
         if(cmp(vec1->ExtRootPathCost, !=, vec2->ExtRootPathCost))
             return false;
     }
 
     if(cmp(time1->remainingHops, !=, time2->remainingHops))
         return false;
 
     if(cmp(vec1->RRootID, !=, vec2->RRootID))
         return false;
     if(cmp(vec1->IntRootPathCost, !=, vec2->IntRootPathCost))
         return false;
     if(cmp(vec1->DesignatedBridgeID, !=, vec2->DesignatedBridgeID))
         return false;
     if(cmp(vec1->DesignatedPortID, !=, vec2->DesignatedPortID))
         return false;
 
     return true;
 }
 
 static bool betterorsamePriority(port_priority_vector_t *vec1,
                                  port_priority_vector_t *vec2,
                                  port_identifier_t pId1,
                                  port_identifier_t pId2,
                                  bool cist)
 {
     int result;
 
     if(cist)
     {
         if(0 < (result = _ncmp(vec1->RootID, vec2->RootID)))
             return false; /* worse */
         else if(0 > result)
             return true; /* better */
         /* The same. Check further. */
         if(0 < (result = _ncmp(vec1->ExtRootPathCost, vec2->ExtRootPathCost)))
             return false; /* worse */
         else if(0 > result)
             return true; /* better */
         /* The same. Check further. */
     }
 
     if(0 < (result = _ncmp(vec1->RRootID, vec2->RRootID)))
         return false; /* worse */
     else if(0 > result)
         return true; /* better */
     /* The same. Check further. */
 
     if(0 < (result = _ncmp(vec1->IntRootPathCost, vec2->IntRootPathCost)))
         return false; /* worse */
     else if(0 > result)
         return true; /* better */
     /* The same. Check further. */
 
     if(0 < (result = _ncmp(vec1->DesignatedBridgeID, vec2->DesignatedBridgeID)))
         return false; /* worse */
     else if(0 > result)
         return true; /* better */
     /* The same. Check further. */
 
     if(0 < (result = _ncmp(vec1->DesignatedPortID, vec2->DesignatedPortID)))
         return false; /* worse */
     else if(0 > result)
         return true; /* better */
     /* The same. Check further. */
 
     /* Port ID is a tie-breaker */
     return cmp(pId1, <=, pId2);
 }
 
 /* 13.26.1 betterorsameInfo */
 static bool betterorsameInfo(per_tree_port_t *ptp, port_info_origin_t newInfoIs)
 {
     if((ioReceived == newInfoIs) && (ioReceived == ptp->infoIs))
         return betterorsamePriority(&ptp->msgPriority,
                                     &ptp->portPriority,
                                     0, 0, (0 == ptp->MSTID));
     else if((ioMine == newInfoIs) && (ioMine == ptp->infoIs))
         return betterorsamePriority(&ptp->designatedPriority,
                                     &ptp->portPriority,
                                     0, 0, (0 == ptp->MSTID));
     return false;
 }
 
 /* 13.26.2 clearAllRcvdMsgs */
 static bool clearAllRcvdMsgs(port_t *prt, bool dry_run)
 {
     per_tree_port_t *ptp;
 
     if(dry_run)
     {
         FOREACH_PTP_IN_PORT(ptp, prt)
             if(ptp->rcvdMsg)
                 return true;
         return false;
     }
 
     FOREACH_PTP_IN_PORT(ptp, prt)
         ptp->rcvdMsg = false;
 
     return false;
 }
 
 /* 13.26.3 clearReselectTree */
 static void clearReselectTree(tree_t *tree)
 {
     per_tree_port_t *ptp;
 
     FOREACH_PTP_IN_TREE(ptp, tree)
         ptp->reselect = false;
 }
 
 /* 13.26.4 fromSameRegion */
 static bool fromSameRegion(port_t *prt)
 {
     /* Check for rcvdRSTP is superfluous here */
     if((protoMSTP > prt->rcvdBpduData.protocolVersion)/* || (!prt->rcvdRSTP)*/)
         return false;
     return cmp(prt->bridge->MstConfigId,
                ==, prt->rcvdBpduData.mstConfigurationIdentifier);
 }
 
 /* 13.26.5 newTcWhile */
 static void newTcWhile(per_tree_port_t *ptp)
 {
     if(0 != ptp->tcWhile)
         return;
 
     tree_t *tree = ptp->tree;
     port_t *prt = ptp->port;
 
     if(prt->sendRSTP)
     {
         per_tree_port_t *cist = GET_CIST_PTP_FROM_PORT(prt);
 
         ptp->tcWhile = cist->portTimes.Hello_Time + 1;
         set_TopologyChange(tree, true, prt);
 
         if(0 == ptp->MSTID)
             prt->newInfo = true;
         else
             prt->newInfoMsti = true;
         return;
     }
 
     times_t *times = &tree->rootTimes;
 
     ptp->tcWhile = times->Max_Age + times->Forward_Delay;
     set_TopologyChange(tree, true, prt);
 }
 
 /* 13.26.6 rcvInfo */
 static port_info_t rcvInfo(per_tree_port_t *ptp)
 {
     msti_configuration_message_t *msti_msg;
     per_tree_port_t *ptp_1;
     bool roleIsDesignated, cist;
     bool msg_Better_port, msg_SamePriorityAndTimers_port;
     port_priority_vector_t *mPri = &(ptp->msgPriority);
     times_t *mTimes = &(ptp->msgTimes);
     port_t *prt = ptp->port;
     bpdu_t *b = &(prt->rcvdBpduData);
 
     if(bpduTypeTCN == b->bpduType)
     {
         prt->rcvdTcn = true;
         FOREACH_PTP_IN_PORT(ptp_1, prt)
             ptp_1->rcvdTc = true;
         return OtherInfo;
     }
 
     if(0 == ptp->MSTID)
     { /* CIST */
         if(protoSTP != b->protocolVersion)
         {
             switch(BPDU_FLAGS_ROLE_GET(b->flags))
             {
                 case encodedRoleAlternateBackup:
                 case encodedRoleRoot:
                     roleIsDesignated = false;
                     break;
                 case encodedRoleDesignated:
                     roleIsDesignated = true;
                     break;
                 case encodedRoleMaster:
                     /* 802.1D-2004 S9.2.9 P61. The Unknown value of Port Role
                      * cannot be generated by a valid implementation; however,
                      * this value is accepted on receipt. roleMaster in MSTP is
                      * roleUnknown in RSTP.
                      * NOTE.If the Unknown value of the Port Role parameter is
                      * received, the state machines will effectively treat the RST
                      * BPDU as if it were a Configuration BPDU
                      */
                     if(protoRSTP == b->protocolVersion)
                     {
                         roleIsDesignated = true;
                         break;
                     }
                     else
                     {
                         return OtherInfo;
                     }
                     break;
                 default:
                     return OtherInfo;
             }
         }
         else
         { /* 13.26.6.NOTE: A Configuration BPDU implicitly conveys a
            *   Designated Port Role */
             roleIsDesignated = true;
         }
         cist = true;
 
         assign(mPri->RRootID, b->cistRRootID);
         assign(mPri->DesignatedPortID, b->cistPortID);
         assign(mPri->RootID, b->cistRootID);
         assign(mPri->ExtRootPathCost, b->cistExtRootPathCost);
         /* messageTimes */
 #define NEAREST_WHOLE_SECOND(msgTime)  \
     ((128 > msgTime[1]) ? msgTime[0] : msgTime[0] + 1)
         mTimes->Forward_Delay = NEAREST_WHOLE_SECOND(b->ForwardDelay);
         mTimes->Max_Age = NEAREST_WHOLE_SECOND(b->MaxAge);
         mTimes->Message_Age = NEAREST_WHOLE_SECOND(b->MessageAge);
         mTimes->Hello_Time = NEAREST_WHOLE_SECOND(b->HelloTime);
         if(protoMSTP > b->protocolVersion)
         { /* STP Configuration BPDU or RST BPDU */
             assign(mPri->IntRootPathCost, __constant_cpu_to_be32(0));
             assign(mPri->DesignatedBridgeID, b->cistRRootID);
             /* messageTimes.remainingHops */
             assign(mTimes->remainingHops, prt->bridge->MaxHops);
         }
         else
         { /* MST BPDU */
             assign(mPri->IntRootPathCost, b->cistIntRootPathCost);
             assign(mPri->DesignatedBridgeID, b->cistBridgeID);
             /* messageTimes.remainingHops */
             assign(mTimes->remainingHops, b->cistRemainingHops);
         }
     }
     else
     { /* MSTI */
         if(protoMSTP > b->protocolVersion)
             return OtherInfo;
         msti_msg = ptp->rcvdMstiConfig;
         switch(BPDU_FLAGS_ROLE_GET(msti_msg->flags))
         {
             case encodedRoleAlternateBackup:
             case encodedRoleRoot:
                 roleIsDesignated = false;
                 break;
             case encodedRoleDesignated:
                 roleIsDesignated = true;
                 break;
             default:
                 return OtherInfo;
         }
         cist = false;
 
         assign(mPri->RRootID, msti_msg->mstiRRootID);
         assign(mPri->IntRootPathCost, msti_msg->mstiIntRootPathCost);
         /* Build MSTI DesignatedBridgeID */
         assign(mPri->DesignatedBridgeID, b->cistBridgeID);
         assign(mPri->DesignatedBridgeID.s.priority, ptp->MSTID);
         SET_PRIORITY_IN_IDENTIFIER(msti_msg->bridgeIdentifierPriority,
                                    mPri->DesignatedBridgeID);
         /* Build MSTI DesignatedPortID */
         assign(mPri->DesignatedPortID, b->cistPortID);
         SET_PRIORITY_IN_IDENTIFIER(msti_msg->portIdentifierPriority,
                                    mPri->DesignatedPortID);
         /* messageTimes */
         assign(mTimes->remainingHops, msti_msg->remainingHops);
     }
 
     msg_Better_port = !betterorsamePriority(&(ptp->portPriority), mPri,
                                             0, 0, cist);
     if(roleIsDesignated)
     {
         /* a).1) */
         if(msg_Better_port
            || ((0 == memcmp(mPri->DesignatedBridgeID.s.mac_address,
                             ptp->portPriority.DesignatedBridgeID.s.mac_address,
                             ETH_ALEN)
                )
                && (0 == ((mPri->DesignatedPortID
                           ^ ptp->portPriority.DesignatedPortID
                          ) & __constant_cpu_to_be16(0x0FFF)
                         )
                   )
               )
           )
             return SuperiorDesignatedInfo;
 
         /* a).2) */
         /* We already know that msgPriority _IS_NOT_BETTER_than portPriority.
          * So, if msgPriority _IS_SAME_OR_BETTER_than portPriority then
          *   msgPriority _IS_SAME_as portPriority.
         */
         msg_SamePriorityAndTimers_port =
             samePriorityAndTimers(mPri, &(ptp->portPriority),
                                   mTimes, &(ptp->portTimes),
                                   cist);
         if((!msg_SamePriorityAndTimers_port)
            && betterorsamePriority(mPri, &(ptp->portPriority), 0, 0, cist)
           )
             return SuperiorDesignatedInfo;
 
         /* b) */
         if(msg_SamePriorityAndTimers_port && (ioReceived == ptp->infoIs))
             return RepeatedDesignatedInfo;
 
         /* c) */
         return InferiorDesignatedInfo;
     }
 
     /* d) */
     if(!msg_Better_port)
         return InferiorRootAlternateInfo;
 
     return OtherInfo;
 }
 
 /* 13.26.7 recordAgreement */
 static void recordAgreement(per_tree_port_t *ptp)
 {
     bool cist_agreed, cist_proposing;
     per_tree_port_t *cist;
     port_t *prt = ptp->port;
     bpdu_t *b = &(prt->rcvdBpduData);
 
     if(0 == ptp->MSTID)
     { /* CIST */
         if(rstpVersion(prt->bridge) && prt->operPointToPointMAC
            && (b->flags & (1 << offsetAgreement))
           )
         {
             ptp->agreed = true;
             ptp->proposing = false;
         }
         else
             ptp->agreed = false;
         cist_agreed = ptp->agreed;
         cist_proposing = ptp->proposing;
         if(!prt->rcvdInternal)
             list_for_each_entry_continue(ptp, &prt->trees, port_list)
             {
                 ptp->agreed = cist_agreed;
                 ptp->proposing = cist_proposing;
             }
         return;
     }
     /* MSTI */
     cist = GET_CIST_PTP_FROM_PORT(prt);
     if(prt->operPointToPointMAC 
        && cmp(b->cistRootID, ==, cist->portPriority.RootID)
        && cmp(b->cistExtRootPathCost, ==, cist->portPriority.ExtRootPathCost)
        && cmp(b->cistRRootID, ==, cist->portPriority.RRootID)
        && (ptp->rcvdMstiConfig->flags & (1 << offsetAgreement))
       )
     {
         ptp->agreed = true;
         ptp->proposing = false;
     }
     else
         ptp->agreed = false;
 }
 
 /* 13.26.8 recordDispute */
 static void recordDispute(per_tree_port_t *ptp)
 {
     port_t *prt;
 
     if(0 == ptp->MSTID)
     { /* CIST */
         prt = ptp->port;
         /* 802.1Q-2005(-2011) is somewhat unclear for the case
          *  (!prt->rcvdInternal): if we should record dispute for all MSTIs
          *  unconditionally or only when CIST Learning flag is set in BPDU.
          * I guess that in this case MSTIs should be in sync with CIST
          * so record dispute for the MSTIs only when the same is done for CIST.
          * Additional supporting argument to this guess is that in
          *  setTcFlags() we do the same.
          * But that is only a guess and I could be wrong here ;)
          */
         if(prt->rcvdBpduData.flags & (1 << offsetLearnig))
         {
             ptp->disputed = true;
             ptp->agreed = false;
             if(!prt->rcvdInternal)
                 list_for_each_entry_continue(ptp, &prt->trees, port_list)
                 {
                     ptp->disputed = true;
                     ptp->agreed = false;
                 }
         }
         return;
     }
     /* MSTI */
     if(ptp->rcvdMstiConfig->flags & (1 << offsetLearnig))
     {
         ptp->disputed = true;
         ptp->agreed = false;
     }
 }
 
 /* 13.26.9 recordMastered */
 static void recordMastered(per_tree_port_t *ptp)
 {
     port_t *prt = ptp->port;
 
     if(0 == ptp->MSTID)
     { /* CIST */
         if(!prt->rcvdInternal)
             list_for_each_entry_continue(ptp, &prt->trees, port_list)
                 ptp->mastered = false;
         return;
     }
     /* MSTI */
     ptp->mastered = prt->operPointToPointMAC
                     && (ptp->rcvdMstiConfig->flags & (1 << offsetMaster));
 }
 
 /* 13.26.f) recordPriority */
 static void recordPriority(per_tree_port_t *ptp)
 {
     assign(ptp->portPriority, ptp->msgPriority);
 }
 
 /* 13.26.10 recordProposal */
 static void recordProposal(per_tree_port_t *ptp)
 {
     bool cist_proposed;
     port_t *prt;
 
     /* 802.1Q-2005 says to check if received message conveys
      *  a Designated Port Role. But there is no need in this check,
      *  as it is always true. This function is called only in two states:
      *  PISM_SUPERIOR_DESIGNATED and PISM_REPEATED_DESIGNATED, which
      *  can be entered only if rcvInfo returns
      *  SuperiorDesignatedInfo or RepeatedDesignatedInfo.
      *  Which in turn can only happen if message conveys designated role
      *   (see rcvInfo).
      */
     if(0 == ptp->MSTID)
     { /* CIST */
         prt = ptp->port;
         if(prt->rcvdBpduData.flags & (1 << offsetProposal))
             ptp->proposed = true;
         cist_proposed = ptp->proposed;
         if(!prt->rcvdInternal)
             list_for_each_entry_continue(ptp, &prt->trees, port_list)
                 ptp->proposed = cist_proposed;
         return;
     }
     /* MSTI */
     if(ptp->rcvdMstiConfig->flags & (1 << offsetProposal))
         ptp->proposed = true;
 }
 
 /* 13.26.11 recordTimes */
 static void recordTimes(per_tree_port_t *ptp)
 {
     /* 802.1Q-2005 and 802.1D-2004 both say that we have to copy
      *   Hello_Time from msgTimes to portTimes.
      * 802.1Q-2011, on the other hand, says that Hello_Time should be set
      *   to the default here.
      * As we have configurable Hello_Time, I choose the third option:
      *   preserve the configured Hello_Time, It is in accordance with the
      *   spirit of 802.1Q-2011, if we allow Hello_Time to be configurable.
      */
     __u8 prev_Hello_Time = 0;
     assign(prev_Hello_Time, ptp->portTimes.Hello_Time);
     assign(ptp->portTimes, ptp->msgTimes);
     assign(ptp->portTimes.Hello_Time, prev_Hello_Time);
 }
 
 /* 13.24.s) + 17.19.7 of 802.1D : fdbFlush */
 static void set_fdbFlush(per_tree_port_t *ptp)
 {
     port_t *prt = ptp->port;
 
     if(prt->operEdge || prt->deleted)
     {
         ptp->fdbFlush = false;
         return;
     }
 
     bridge_t *br = prt->bridge;
 
     if(rstpVersion(br))
     {
         ptp->fdbFlush = true;
         ptp->calledFromFlushRoutine = true;
         MSTP_OUT_flush_all_fids(ptp);
         ptp->calledFromFlushRoutine = false;
     }
     else
     {
         per_tree_port_t *cist = GET_CIST_PTP_FROM_PORT(prt);
         unsigned int FwdDelay = cist->designatedTimes.Forward_Delay;
         /* Initiate rapid ageing */
         MSTP_OUT_set_ageing_time(prt, FwdDelay);
         assign(prt->rapidAgeingWhile, FwdDelay);
         ptp->fdbFlush = false;
     }
 }
 
 /* 13.26.12 setRcvdMsgs */
 static void setRcvdMsgs(port_t *prt)
 {
     msti_configuration_message_t *msti_msg;
     int i;
     __be16 msg_MSTID;
     bool found;
     per_tree_port_t *ptp = GET_CIST_PTP_FROM_PORT(prt);
     ptp->rcvdMsg = true;
 
     /* 802.1Q-2005 says:
      *   "Make the received CST or CIST message available to the CIST Port
      *    Information state machines"
      * No need to do something special here, we already have rcvdBpduData.
      */
 
     if(prt->rcvdInternal)
     {
         list_for_each_entry_continue(ptp, &prt->trees, port_list)
         {
             found = false;
             /* Find if message for this MSTI is conveyed in the BPDU */
             for(i = 0, msti_msg = prt->rcvdBpduData.mstConfiguration;
                 i < prt->rcvdBpduNumOfMstis;
                 ++i, ++msti_msg)
             {
                 msg_MSTID = msti_msg->mstiRRootID.s.priority
                             & __constant_cpu_to_be16(0x0FFF);
                 if(msg_MSTID == ptp->MSTID)
                 {
                     found = true;
                     break;
                 }
             }
             if(found)
             {
                 ptp->rcvdMsg = true;
                 /* 802.1Q-2005 says:
                  *   "Make available each MSTI message and the common parts of
                  *    the CIST message priority (the CIST Root Identifier,
                  *    External Root Path Cost and Regional Root Identifier)
                  *    to the Port Information state machine for that MSTI"
                  * We set pointer to the MSTI configuration message for
                  * fast access, while do not anything special for common
                  * parts of the message, as the whole message is available
                  * in rcvdBpduData.
                  */
                 ptp->rcvdMstiConfig = msti_msg;
             }
         }
     }
 }
 
 /* 13.26.13 setReRootTree */
 static void setReRootTree(tree_t *tree)
 {
     per_tree_port_t *ptp;
 
     FOREACH_PTP_IN_TREE(ptp, tree)
         ptp->reRoot = true;
 }
 
 /* 13.26.14 setSelectedTree */
 static void setSelectedTree(tree_t *tree)
 {
     per_tree_port_t *ptp;
 
     /*
      * 802.1Q-2005 says that I should check "reselect" var
      * and take no action if it is "true" for any of the ports.
      * But there is no need in this check as setSelectedTree is called
      * only from PRSSM_to_ROLE_SELECTION, which is atomic, and it is called
      * in this sequence (13.33):
      *   clearReselectTree(tree);
      *   updtRolesTree(tree);
      *   setSelectedTree(tree);
      * And we know that clearReselectTree resets "reselect" for all ports
      * and updtRolesTree() does not change value of "reselect".
      */
     FOREACH_PTP_IN_TREE(ptp, tree)
         ptp->selected = true;
 }
 
 /* 13.26.15 setSyncTree */
 static void setSyncTree(tree_t *tree)
 {
     per_tree_port_t *ptp;
 
     FOREACH_PTP_IN_TREE(ptp, tree)
         ptp->sync = true;
 }
 
 /* 13.26.16 setTcFlags */
 static void setTcFlags(per_tree_port_t *ptp)
 {
     __u8 cistFlags;
     port_t *prt;
 
     if(0 == ptp->MSTID)
     { /* CIST */
         prt = ptp->port;
         cistFlags = prt->rcvdBpduData.flags;
         if(cistFlags & (1 << offsetTcAck))
             prt->rcvdTcAck = true;
         if(cistFlags & (1 << offsetTc))
         {
             ptp->rcvdTc = true;
             if(!prt->rcvdInternal)
                 list_for_each_entry_continue(ptp, &prt->trees, port_list)
                     ptp->proposed = true;
         }
         return;
     }
     /* MSTI */
     if(ptp->rcvdMstiConfig->flags & (1 << offsetTc))
         ptp->rcvdTc = true;
 }
 
 /* 13.26.17 setTcPropTree */
 static void setTcPropTree(per_tree_port_t *ptp)
 {
     per_tree_port_t *ptp_1;
 
     if(ptp->port->restrictedTcn)
         return;
 
     FOREACH_PTP_IN_TREE(ptp_1, ptp->tree)
     {
         if(ptp != ptp_1)
             ptp_1->tcProp = true;
     }
 }
 
 /* 13.26.18 syncMaster */
 static void syncMaster(bridge_t *br)
 {
     per_tree_port_t *ptp;
     tree_t *tree = GET_CIST_TREE(br);
 
     /* For each MSTI */
     list_for_each_entry_continue(tree, &br->trees, bridge_list)
     {
         FOREACH_PTP_IN_TREE(ptp, tree)
         {
             /* for each Port that has infoInternal set */
             if(ptp->port->infoInternal)
             {
                 ptp->agree = false;
                 ptp->agreed = false;
                 ptp->synced = false;
                 ptp->sync = true;
             }
         }
     }
 }
 
 /* 13.26.19 txConfig */
 static void txConfig(port_t *prt)
 {
     bpdu_t b;
     per_tree_port_t *cist = GET_CIST_PTP_FROM_PORT(prt);
 
     if(prt->deleted || (roleDisabled == cist->role) || prt->dontTxmtBpdu)
         return;
 
     b.protocolIdentifier = 0;
     b.protocolVersion = protoSTP;
     b.bpduType = bpduTypeConfig;
     /* Standard says "tcWhile ... for the Port". Which one tcWhile?
      * I guess that this means tcWhile for the CIST.
      * But that is only a guess and I could be wrong here ;)
      */
     b.flags = (0 != cist->tcWhile) ? (1 << offsetTc) : 0;
     if(prt->tcAck)
         b.flags |= (1 << offsetTcAck);
     assign(b.cistRootID, cist->designatedPriority.RootID);
     assign(b.cistExtRootPathCost, cist->designatedPriority.ExtRootPathCost);
     assign(b.cistRRootID, cist->designatedPriority.DesignatedBridgeID);
     assign(b.cistPortID, cist->designatedPriority.DesignatedPortID);
     b.MessageAge[0] = cist->designatedTimes.Message_Age;
     b.MessageAge[1] = 0;
     b.MaxAge[0] = cist->designatedTimes.Max_Age;
     b.MaxAge[1] = 0;
     b.HelloTime[0] = cist->portTimes.Hello_Time; /* ! use portTimes ! */
     b.HelloTime[1] = 0;
     b.ForwardDelay[0] = cist->designatedTimes.Forward_Delay;
     b.ForwardDelay[1] = 0;
 
     MSTP_OUT_tx_bpdu(prt, &b, CONFIG_BPDU_SIZE);
 }
 
 static inline __u8 message_role_from_port_role(per_tree_port_t *ptp)
 {
     switch(ptp->role)
     {
         case roleRoot:
             return encodedRoleRoot;
         case roleDesignated:
             return encodedRoleDesignated;
         case roleAlternate:
         case roleBackup:
             return encodedRoleAlternateBackup;
         case roleMaster:
             return encodedRoleMaster;
         default:
             ERROR_PRTNAME(ptp->port->bridge, ptp->port,
                           "Attempt to send from port with Disabled role");
             return encodedRoleAlternateBackup;
     }
 }
 
 /* 802.1Q-2005: 13.26.20 txMstp
  * 802.1Q-2011: 13.27.27 txRstp
  */
 static void txMstp(port_t *prt)
 {
     bpdu_t b;
     bridge_t *br = prt->bridge;
     per_tree_port_t *cist = GET_CIST_PTP_FROM_PORT(prt);
     int msti_msgs_total_size;
     per_tree_port_t *ptp;
     msti_configuration_message_t *msti_msg;
 
     if(prt->deleted || (roleDisabled == cist->role) || prt->dontTxmtBpdu)
         return;
 
     b.protocolIdentifier = 0;
     b.bpduType = bpduTypeRST;
     /* Standard says "{tcWhile, agree, proposing} ... for the Port".
      * Which one {tcWhile, agree, proposing}?
      * I guess that this means {tcWhile, agree, proposing} for the CIST.
      * But that is only a guess and I could be wrong here ;)
      */
     b.flags = BPDU_FLAGS_ROLE_SET(message_role_from_port_role(cist));
     if(0 != cist->tcWhile)
         b.flags |= (1 << offsetTc);
     if(cist->proposing)
         b.flags |= (1 << offsetProposal);
     if(cist->learning)
         b.flags |= (1 << offsetLearnig);
     if(cist->forwarding)
         b.flags |= (1 << offsetForwarding);
     if(cist->agree)
         b.flags |= (1 << offsetAgreement);
     assign(b.cistRootID, cist->designatedPriority.RootID);
     assign(b.cistExtRootPathCost, cist->designatedPriority.ExtRootPathCost);
     assign(b.cistRRootID, cist->designatedPriority.RRootID);
     assign(b.cistPortID, cist->designatedPriority.DesignatedPortID);
     b.MessageAge[0] = cist->designatedTimes.Message_Age;
     b.MessageAge[1] = 0;
     b.MaxAge[0] = cist->designatedTimes.Max_Age;
     b.MaxAge[1] = 0;
     b.HelloTime[0] = cist->portTimes.Hello_Time; /* ! use portTimes ! */
     b.HelloTime[1] = 0;
     b.ForwardDelay[0] = cist->designatedTimes.Forward_Delay;
     b.ForwardDelay[1] = 0;
 
     b.version1_len = 0;
 
     if(br->ForceProtocolVersion < protoMSTP)
     {
         b.protocolVersion = protoRSTP;
         MSTP_OUT_tx_bpdu(prt, &b, RST_BPDU_SIZE);
         return;
     }
 
     b.protocolVersion = protoMSTP;
 
     /* MST specific fields */
     assign(b.mstConfigurationIdentifier, br->MstConfigId);
     assign(b.cistIntRootPathCost, cist->designatedPriority.IntRootPathCost);
     assign(b.cistBridgeID, cist->designatedPriority.DesignatedBridgeID);
     assign(b.cistRemainingHops, cist->designatedTimes.remainingHops);
 
     msti_msgs_total_size = 0;
     ptp = cist;
     msti_msg = b.mstConfiguration;
     /* 13.26.20.f) requires that msti configs should be inserted in
      * MSTID order. This is met by inserting trees in port's list of trees
      * in sorted (by MSTID) order (see MSTP_IN_create_msti) */
     list_for_each_entry_continue(ptp, &prt->trees, port_list)
     {
         msti_msg->flags =
             BPDU_FLAGS_ROLE_SET(message_role_from_port_role(ptp));
         if(0 != ptp->tcWhile)
             msti_msg->flags |= (1 << offsetTc);
         if(ptp->proposing)
             msti_msg->flags |= (1 << offsetProposal);
         if(ptp->learning)
             msti_msg->flags |= (1 << offsetLearnig);
         if(ptp->forwarding)
             msti_msg->flags |= (1 << offsetForwarding);
         if(ptp->agree)
             msti_msg->flags |= (1 << offsetAgreement);
         if(ptp->master)
             msti_msg->flags |= (1 << offsetMaster);
         assign(msti_msg->mstiRRootID, ptp->designatedPriority.RRootID);
         assign(msti_msg->mstiIntRootPathCost,
                ptp->designatedPriority.IntRootPathCost);
         msti_msg->bridgeIdentifierPriority =
             GET_PRIORITY_FROM_IDENTIFIER(ptp->designatedPriority.DesignatedBridgeID);
         msti_msg->portIdentifierPriority =
             GET_PRIORITY_FROM_IDENTIFIER(ptp->designatedPriority.DesignatedPortID);
         assign(msti_msg->remainingHops, ptp->designatedTimes.remainingHops);
 
         msti_msgs_total_size += sizeof(msti_configuration_message_t);
         ++msti_msg;
     }
 
     assign(b.version3_len, __cpu_to_be16(MST_BPDU_VER3LEN_WO_MSTI_MSGS
                                          + msti_msgs_total_size));
     MSTP_OUT_tx_bpdu(prt, &b, MST_BPDU_SIZE_WO_MSTI_MSGS
                               + msti_msgs_total_size);
 }
 
 /* 13.26.a) txTcn */
 static void txTcn(port_t *prt)
 {
     bpdu_t b;
     per_tree_port_t *cist = GET_CIST_PTP_FROM_PORT(prt);
 
     if(prt->deleted || (roleDisabled == cist->role) || prt->dontTxmtBpdu)
         return;
 
     b.protocolIdentifier = 0;
     b.protocolVersion = protoSTP;
     b.bpduType = bpduTypeTCN;
 
     MSTP_OUT_tx_bpdu(prt, &b, TCN_BPDU_SIZE);
 }
 
 /* 13.26.21 updtBPDUVersion */
 static void updtBPDUVersion(port_t *prt)
 {
     if(protoRSTP <= prt->rcvdBpduData.protocolVersion)
         prt->rcvdRSTP = true;
     else
         prt->rcvdSTP = true;
 }
 
 /* 13.26.22 updtRcvdInfoWhile */
 static void updtRcvdInfoWhile(per_tree_port_t *ptp)
 {
     port_t *prt = ptp->port;
     per_tree_port_t *cist = GET_CIST_PTP_FROM_PORT(prt);
     unsigned int Message_Age = cist->portTimes.Message_Age;
     unsigned int Max_Age = cist->portTimes.Max_Age;
     unsigned int Hello_Time = cist->portTimes.Hello_Time;
 
     /* NOTE: 802.1Q-2005(-2011) says that we should use
      *  "remainingHops ... from the CIST's portTimes parameter"
      *  As for me this is clear oversight in the standard,
      *  the remainingHops should be taken form the port's own portTimes,
      *  not from CIST's. After all, if we don't use port's own
      *  remainingHops here, they aren't used anywhere at all.
      *  Besides, there is a scenario which breaks if we use CIST's
      *  remainingHops here:
      *   1) Connect two switches (SW1,SW2) with two ports, thus forming a loop
      *   2) Configure them to be in the same region, with two trees:
      *      0 (CIST) and 1.
      *   3) at SW1# mstpctl settreeprio br0 1 4
      *      SW1 becomes regional root in tree 1
      *   4) at SW2# mstpctl settreeprio br0 1 14
      *   5) at SW1# mstpctl settreeprio br0 1 9
      *
      *  And now we have the classic "count-to-infinity" problem when the old
      *  info ("Regional Root is SW1 with priority 4") circulates in the loop,
      *  because it is better than current info ("Regional Root is SW1 with
      *  priority 9"). The only way to get rid of that old info is
      *  to age it out by the means of remainingHops counter.
      *  In this situation we certainly must use counter from tree 1,
      *  not CIST's.
      */
     if((!prt->rcvdInternal && ((Message_Age + 1) <= Max_Age))
        || (prt->rcvdInternal && (ptp->portTimes.remainingHops > 1))
       )
         ptp->rcvdInfoWhile = 3 * Hello_Time;
     else
         ptp->rcvdInfoWhile = 0;
 }
 
 static void updtbrAssuRcvdInfoWhile(port_t *prt)
 {
     per_tree_port_t *cist = GET_CIST_PTP_FROM_PORT(prt);
 
     prt->brAssuRcvdInfoWhile = 3 * cist->portTimes.Hello_Time;
 }
 
 /* 13.26.24 updtRolesDisabledTree */
 static void updtRolesDisabledTree(tree_t *tree)
 {
     per_tree_port_t *ptp;
 
     FOREACH_PTP_IN_TREE(ptp, tree)
         ptp->selectedRole = roleDisabled;
 }
 
 /* Aux function, not in standard.
  * Sets reselect for all MSTIs in the case CIST state for the port changes
  */
 static void reselectMSTIs(port_t *prt)
 {
     per_tree_port_t *ptp = GET_CIST_PTP_FROM_PORT(prt);
 
     /* For each non-CIST ptp */
     list_for_each_entry_continue(ptp, &prt->trees, port_list)
         ptp->reselect = true;
 }
 
 /* 13.26.23 updtRolesTree */
 static void updtRolesTree(tree_t *tree)
 {
     per_tree_port_t *ptp, *root_ptp = NULL;
     port_priority_vector_t root_path_priority;
     bridge_identifier_t prevRRootID = tree->rootPriority.RRootID;
     __be32 prevExtRootPathCost = tree->rootPriority.ExtRootPathCost;
     bool cist = (0 == tree->MSTID);
 
     /* a), b) Select new root priority vector = {rootPriority, rootPortId} */
       /* Initial value = bridge priority vector = {BridgePriority, 0} */
     assign(tree->rootPriority, tree->BridgePriority);
     assign(tree->rootPortId, __constant_cpu_to_be16(0));
       /* Now check root path priority vectors of all ports in tree and see if
        * there is a better vector */
     FOREACH_PTP_IN_TREE(ptp, tree)
     {
         port_t *prt = ptp->port;
         /* 802.1Q says to calculate root priority vector only if port
          * is not Disabled, but check (infoIs == ioReceived) covers
          * the case (infoIs != ioDisabled).
          */
         if((ioReceived == ptp->infoIs) && !prt->restrictedRole
            && cmp(ptp->portPriority.DesignatedBridgeID, !=,
                   tree->BridgeIdentifier)
           )
         {
             root_path_priority = ptp->portPriority;
             if(prt->rcvdInternal)
             {
                 assign(root_path_priority.IntRootPathCost,
                        __cpu_to_be32(__be32_to_cpu(root_path_priority.IntRootPathCost)
                                      + ptp->InternalPortPathCost)
                       );
             }
             else if(cist) /* Yes, this check might be superfluous,
                            * but I want to be on the safe side */
             {
                 assign(root_path_priority.ExtRootPathCost,
                        __cpu_to_be32(__be32_to_cpu(root_path_priority.ExtRootPathCost)
                                      + prt->ExternalPortPathCost)
                       );
                 assign(root_path_priority.RRootID, tree->BridgeIdentifier);
                 assign(root_path_priority.IntRootPathCost,
                        __constant_cpu_to_be32(0));
             }
             if(betterorsamePriority(&root_path_priority, &tree->rootPriority,
                                     ptp->portId, tree->rootPortId, cist))
             {
                 assign(tree->rootPriority, root_path_priority);
                 assign(tree->rootPortId, ptp->portId);
                 root_ptp = ptp;
             }
         }
     }
 
     /* 802.1q-2005 says, that at some point we need compare portTimes with
      * "... one for the Root Port ...". Bad IEEE! Why not mention explicit
      * var names??? (see 13.26.23.g) for instance)
      * These comparisons happen three times, twice in clause g)
      *   and once in clause i). Look for samePriorityAndTimers() calls.
      * So, now I should guess what will work for the "times for the Root Port".
      * Thanks to Rajani's experiments I know for sure that I should use
      *  designatedTimes here. Thank you, Rajani!
      * NOTE: Both Alex Rozin (author of rstplib) and Srinivas Aji (author
      *   of rstpd) also compare portTimes with designatedTimes.
      */
 
     /* c) Set new rootTimes */
     if(root_ptp)
     {
         assign(tree->rootTimes, root_ptp->portTimes);
         port_t *prt = root_ptp->port;
         if(prt->rcvdInternal)
         {
             if(tree->rootTimes.remainingHops)
                 --(tree->rootTimes.remainingHops);
         }
         else
             ++(tree->rootTimes.Message_Age);
     }
     else
     {
         assign(tree->rootTimes, tree->BridgeTimes);
     }
 
     FOREACH_PTP_IN_TREE(ptp, tree)
     {
         port_t *prt = ptp->port;
 
         /* d) Set new designatedPriority */
         assign(ptp->designatedPriority, tree->rootPriority);
         assign(ptp->designatedPriority.DesignatedBridgeID,
                tree->BridgeIdentifier);
         assign(ptp->designatedPriority.DesignatedPortID, ptp->portId);
         /* I am not sure which condition to check here, as 802.1Q-2005 says:
          * "... If {Port} is attached to a LAN that has one or more STP Bridges
          *  attached (as determined by the Port Protocol Migration state
          * machine) ..." -- why not to mention explicit var name? Bad IEEE.
          * But I guess that sendSTP (i.e. !sendRSTP) var will do ;)
          */
         if(cist && !prt->sendRSTP)
             assign(ptp->designatedPriority.RRootID, tree->BridgeIdentifier);
 
         /* e) Set new designatedTimes */
         assign(ptp->designatedTimes, tree->rootTimes);
         /* Keep the configured Hello_Time for the port.
          * NOTE: this is in accordance with the spirit of 802.1D-2004.
          *    Also, this does not contradict 802.1Q-2005(-2011), as in these
          *    standards both designatedTimes and rootTimes structures
          *    don't have Hello_Time member.
          */
         assign(ptp->designatedTimes.Hello_Time, ptp->portTimes.Hello_Time);
     }
 
     /* syncMaster */
     if(cist && cmp(tree->rootPriority.RRootID, !=, prevRRootID)
        && ((0 != tree->rootPriority.ExtRootPathCost)
            || (0 != prevExtRootPathCost)
           )
       )
         syncMaster(tree->bridge);
 
     FOREACH_PTP_IN_TREE(ptp, tree)
     {
         port_t *prt = ptp->port;
         per_tree_port_t *cist_tree = GET_CIST_PTP_FROM_PORT(prt);
 
         /* f) Set Disabled role */
         if(ioDisabled == ptp->infoIs)
         {
             ptp->selectedRole = roleDisabled;
             continue;
         }
 
         if(!cist && (ioReceived == cist_tree->infoIs) && !prt->infoInternal)
         {
             /* g) Set role for the boundary port in MSTI */
             if(roleRoot == cist_tree->selectedRole)
             {
                 ptp->selectedRole = roleMaster;
                 if(!samePriorityAndTimers(&ptp->portPriority,
                                           &ptp->designatedPriority,
                                           &ptp->portTimes,
                                           &ptp->designatedTimes,
                                           /*cist*/ false))
                     ptp->updtInfo = true;
                 continue;
             }
             /* Bad IEEE again! It says in 13.26.23 g) 2) that
              * MSTI state should follow CIST state only for the case of
              * Alternate port. This is obviously wrong!
              * In the descriptive clause 13.13 f) it says:
              *  "At a Boundary Port frames allocated to the CIST and
              *   all MSTIs are forwarded or not forwarded alike.
              *   This is because Port Role assignments are such that
              *   if the CIST Port Role is Root Port, the MSTI Port Role
              *   will be Master Port, and if the CIST Port Role is
              *   Designated Port, Alternate Port, Backup Port,
              *   or Disabled Port, each MSTI’s Port Role will be the same."
              * So, ignore wrong 13.26.23 g) 2) and do as stated in 13.13 f) !
              */
             /* if(roleAlternate == cist_tree->selectedRole) */
             {
                 ptp->selectedRole = cist_tree->selectedRole;
                 if(!samePriorityAndTimers(&ptp->portPriority,
                                           &ptp->designatedPriority,
                                           &ptp->portTimes,
                                           &ptp->designatedTimes,
                                           /*cist*/ false))
                     ptp->updtInfo = true;
                 continue;
             }
         }
         else
      /* if(cist || (ioReceived != cist_tree->infoIs) || prt->infoInternal) */
         {
             /* h) Set role for the aged info */
             if(ioAged == ptp->infoIs)
             {
                 ptp->selectedRole = roleDesignated;
                 ptp->updtInfo = true;
                 continue;
             }
             /* i) Set role for the mine info */
             if(ioMine == ptp->infoIs)
             {
                 ptp->selectedRole = roleDesignated;
                 if(!samePriorityAndTimers(&ptp->portPriority,
                                           &ptp->designatedPriority,
                                           &ptp->portTimes,
                                           &ptp->designatedTimes,
                                           cist))
                     ptp->updtInfo = true;
                 continue;
             }
             if(ioReceived == ptp->infoIs)
             {
                 /* j) Set Root role */
                 if(root_ptp == ptp)
                 {
                     ptp->selectedRole = roleRoot;
                     ptp->updtInfo = false;
                 }
                 else
                 {
                     if(betterorsamePriority(&ptp->portPriority,
                                              &ptp->designatedPriority,
                                              0, 0, cist))
                     {
                         if(cmp(ptp->portPriority.DesignatedBridgeID, !=,
                                tree->BridgeIdentifier))
                         {
                             /* k) Set Alternate role */
                             ptp->selectedRole = roleAlternate;
                         }
                         else
                         {
                             /* l) Set Backup role */
                             ptp->selectedRole = roleBackup;
                         }
                         /* reset updtInfo for both k) and l) */
                         ptp->updtInfo = false;
                     }
                     else /* designatedPriority is better than portPriority */
                     {
                         /* m) Set Designated role */
                         ptp->selectedRole = roleDesignated;
                         ptp->updtInfo = true;
                     }
                 }
                 /* This is not in standard. But we really should set here
                  * reselect for all MSTIs so that updtRolesTree is called
                  * for each MSTI and due to above clause g) MSTI role is
                  * changed to Master or reflects CIST port role.
                  * Because in 802.1Q-2005 this will not happen when BPDU arrives
                  * at boundary port - the rcvdMsg is not set for the MSTIs and
                  * updtRolesTree is not called.
                  * Bad IEEE !!!
                  */
                 if(cist && (ptp->selectedRole != ptp->role))
                     reselectMSTIs(prt);
                 continue;
             }
         }
     }
 }
 
 /* 13.27  The Port Timers state machine */
 
 static void PTSM_tick(port_t *prt)
 {
     per_tree_port_t *ptp;
 
     if(prt->helloWhen)
         --(prt->helloWhen);
     if(prt->mdelayWhile)
         --(prt->mdelayWhile);
     if(prt->edgeDelayWhile)
         --(prt->edgeDelayWhile);
     if(prt->txCount)
         --(prt->txCount);
     if(prt->brAssuRcvdInfoWhile)
         --(prt->brAssuRcvdInfoWhile);
 
     FOREACH_PTP_IN_PORT(ptp, prt)
     {
         if(ptp->fdWhile)
             --(ptp->fdWhile);
         if(ptp->rrWhile)
             --(ptp->rrWhile);
         if(ptp->rbWhile)
             --(ptp->rbWhile);
         if(ptp->tcWhile)
         {
             if(0 == --(ptp->tcWhile))
                 set_TopologyChange(ptp->tree, false, prt);
         }
         if(ptp->rcvdInfoWhile)
             --(ptp->rcvdInfoWhile);
     }
 }
 
 /* 13.28  Port Receive state machine */
 #define PRSM_begin(prt) PRSM_to_DISCARD((prt), false)
 static bool PRSM_to_DISCARD(port_t *prt, bool dry_run)
 {
     if(dry_run)
     {
         return (prt->PRSM_state != PRSM_DISCARD)
                || prt->rcvdBpdu || prt->rcvdRSTP || prt->rcvdSTP
                || (prt->edgeDelayWhile != prt->bridge->Migrate_Time)
                || clearAllRcvdMsgs(prt, dry_run);
     }
 
     prt->PRSM_state = PRSM_DISCARD;
 
     prt->rcvdBpdu = false;
     prt->rcvdRSTP = false;
     prt->rcvdSTP = false;
     clearAllRcvdMsgs(prt, false /* actual run */);
     assign(prt->edgeDelayWhile, prt->bridge->Migrate_Time);
 
     /* No need to run, no one condition will be met
      * if(!begin)
      *     PRSM_run(prt, false); */
     return false;
 }
 
 static void PRSM_to_RECEIVE(port_t *prt)
 {
     prt->PRSM_state = PRSM_RECEIVE;
 
     updtBPDUVersion(prt);
     prt->rcvdInternal = fromSameRegion(prt);
     setRcvdMsgs(prt);
     prt->operEdge = false;
     prt->rcvdBpdu = false;
     assign(prt->edgeDelayWhile, prt->bridge->Migrate_Time);
 
     /* No need to run, no one condition will be met
       PRSM_run(prt, false); */
 }
 
 static bool PRSM_run(port_t *prt, bool dry_run)
 {
     per_tree_port_t *ptp;
     bool rcvdAnyMsg;
 
     if((prt->rcvdBpdu || (prt->edgeDelayWhile != prt->bridge->Migrate_Time))
        && !prt->portEnabled)
     {
         return PRSM_to_DISCARD(prt, dry_run);
     }
 
     switch(prt->PRSM_state)
     {
         case PRSM_DISCARD:
             if(prt->rcvdBpdu && prt->portEnabled)
             {
                 if(dry_run) /* state change */
                     return true;
                 PRSM_to_RECEIVE(prt);
             }
             return false;
         case PRSM_RECEIVE:
             rcvdAnyMsg = false;
             FOREACH_PTP_IN_PORT(ptp, prt)
             {
                 if(ptp->rcvdMsg)
                 {
                     rcvdAnyMsg = true;
                     break;
                 }
             }
             if(prt->rcvdBpdu && prt->portEnabled && !rcvdAnyMsg)
             {
                 if(dry_run) /* at least rcvdBpdu will change */
                     return true;
                 PRSM_to_RECEIVE(prt);
             }
         default:
             return false;
     }
 }
 
 /* 13.29  Port Protocol Migration state machine */
 
 static bool PPMSM_run(port_t *prt, bool dry_run);
 #define PPMSM_begin(prt) PPMSM_to_CHECKING_RSTP(prt)
 
 static void PPMSM_to_CHECKING_RSTP(port_t *prt/*, bool begin*/)
 {
     prt->PPMSM_state = PPMSM_CHECKING_RSTP;
 
     bridge_t *br = prt->bridge;
     prt->mcheck = false;
     prt->sendRSTP = rstpVersion(br);
     assign(prt->mdelayWhile, br->Migrate_Time);
 
     /* No need to run, no one condition will be met
      * if(!begin)
      *     PPMSM_run(prt, false); */
 }
 
 static void PPMSM_to_SELECTING_STP(port_t *prt)
 {
     prt->PPMSM_state = PPMSM_SELECTING_STP;
 
     prt->sendRSTP = false;
     assign(prt->mdelayWhile, prt->bridge->Migrate_Time);
 
     PPMSM_run(prt, false /* actual run */);
 }
 
 static void PPMSM_to_SENSING(port_t *prt)
 {
     prt->PPMSM_state = PPMSM_SENSING;
 
     prt->rcvdRSTP = false;
     prt->rcvdSTP = false;
 
     PPMSM_run(prt, false /* actual run */);
 }
 
 static bool PPMSM_run(port_t *prt, bool dry_run)
 {
     bridge_t *br = prt->bridge;
 
     switch(prt->PPMSM_state)
     {
         case PPMSM_CHECKING_RSTP:
             if((prt->mdelayWhile != br->Migrate_Time)
                && !prt->portEnabled)
             {
                 if(dry_run) /* at least mdelayWhile will change */
                     return true;
                 PPMSM_to_CHECKING_RSTP(prt);
                 return false;
             }
             if(0 == prt->mdelayWhile)
             {
                 if(dry_run) /* state change */
                     return true;
                 PPMSM_to_SENSING(prt);
             }
             return false;
         case PPMSM_SELECTING_STP:
             if(0 == prt->mdelayWhile || !prt->portEnabled || prt->mcheck)
             {
                 if(dry_run) /* state change */
                     return true;
                 PPMSM_to_SENSING(prt);
             }
             return false;
         case PPMSM_SENSING:
             if(!prt->portEnabled || prt->mcheck
                || (rstpVersion(br) && !prt->sendRSTP && prt->rcvdRSTP))
             {
                 if(dry_run) /* state change */
                     return true;
                 PPMSM_to_CHECKING_RSTP(prt);
                 return false;
             }
             if(prt->sendRSTP && prt->rcvdSTP)
             {
                 if(dry_run) /* state change */
                     return true;
                 PPMSM_to_SELECTING_STP(prt);
             }
             return false;
     }
 
     return false;
 }
 
 /* 13.30  Bridge Detection state machine */
 static void BDSM_to_EDGE(port_t *prt/*, bool begin*/)
 {
     prt->BDSM_state = BDSM_EDGE;
 
     prt->operEdge = true;
 
     /* No need to run, no one condition will be met
      * if(!begin)
      *     BDSM_run(prt, false); */
 }
 
 static void BDSM_to_NOT_EDGE(port_t *prt/*, bool begin*/)
 {
     prt->BDSM_state = BDSM_NOT_EDGE;
 
     prt->operEdge = false;
 
     /* No need to run, no one condition will be met
      * if(!begin)
      *     BDSM_run(prt, false); */
 }
 
 static void BDSM_begin(port_t *prt/*, bool begin*/)
 {
     if(prt->AdminEdgePort)
         BDSM_to_EDGE(prt/*, begin*/);
     else
         BDSM_to_NOT_EDGE(prt/*, begin*/);
 }
 
 static bool BDSM_run(port_t *prt, bool dry_run)
 {
     per_tree_port_t *cist;
 
     switch(prt->BDSM_state)
     {
         case BDSM_EDGE:
             if(((!prt->portEnabled || !prt->AutoEdge) && !prt->AdminEdgePort)
                || !prt->operEdge
               )
             {
                 if(dry_run) /* state change */
                     return true;
                 BDSM_to_NOT_EDGE(prt);
             }
             return false;
         case BDSM_NOT_EDGE:
              cist = GET_CIST_PTP_FROM_PORT(prt);
             /* NOTE: 802.1Q-2005(-2011) is not clear, which of the per-tree
              *  "proposing" flags to use here, or one should combine
              *  them all for all trees?
              * So, I decide that it will be the "proposing" flag
              *  from CIST tree - it seems like a good bet.
              */
             if((!prt->portEnabled && prt->AdminEdgePort)
                || ((0 == prt->edgeDelayWhile) && prt->AutoEdge && prt->sendRSTP
                    && cist->proposing)
               )
             {
                 if(dry_run) /* state change */
                     return true;
                 BDSM_to_EDGE(prt);
             }
         default:
             return false;
     }
 }
 
 /* 13.31  Port Transmit state machine */
 
 static bool PTSM_run(port_t *prt, bool dry_run);
 #define PTSM_begin(prt) PTSM_to_TRANSMIT_INIT((prt), true, false)
 
 static bool PTSM_to_TRANSMIT_INIT(port_t *prt, bool begin, bool dry_run)
 {
     if(dry_run)
     {
         return (prt->PTSM_state != PTSM_TRANSMIT_INIT)
                || (!prt->newInfo) || (!prt->newInfoMsti)
                || (0 != prt->txCount);
     }
 
     prt->PTSM_state = PTSM_TRANSMIT_INIT;
 
     prt->newInfo = true;
     prt->newInfoMsti = true;
     assign(prt->txCount, 0u);
 
     if(!begin && prt->portEnabled) /* prevent infinite loop */
         PTSM_run(prt, false /* actual run */);
     return false;
 }
 
 static void PTSM_to_TRANSMIT_CONFIG(port_t *prt)
 {
     prt->PTSM_state = PTSM_TRANSMIT_CONFIG;
 
     prt->newInfo = false;
     txConfig(prt);
     ++(prt->txCount);
     prt->tcAck = false;
 
     PTSM_run(prt, false /* actual run */);
 }
 
 static void PTSM_to_TRANSMIT_TCN(port_t *prt)
 {
     prt->PTSM_state = PTSM_TRANSMIT_TCN;
 
     prt->newInfo = false;
     txTcn(prt);
     ++(prt->txCount);
 
     PTSM_run(prt, false /* actual run */);
 }
 
 static void PTSM_to_TRANSMIT_RSTP(port_t *prt)
 {
     prt->PTSM_state = PTSM_TRANSMIT_RSTP;
 
     prt->newInfo = false;
     prt->newInfoMsti = false;
     txMstp(prt);
     ++(prt->txCount);
     prt->tcAck = false;
 
     PTSM_run(prt, false /* actual run */);
 }
 
 static void PTSM_to_TRANSMIT_PERIODIC(port_t *prt)
 {
     prt->PTSM_state = PTSM_TRANSMIT_PERIODIC;
 
     per_tree_port_t *ptp = GET_CIST_PTP_FROM_PORT(prt);
     bool cistDesignatedOrTCpropagatingRootPort =
         (roleDesignated == ptp->role)
         || ((roleRoot == ptp->role) && (0 != ptp->tcWhile));
     bool mstiDesignatedOrTCpropagatingRootPort;
 
     mstiDesignatedOrTCpropagatingRootPort = false;
     list_for_each_entry_continue(ptp, &prt->trees, port_list)
     {
         if((roleDesignated == ptp->role)
            || ((roleRoot == ptp->role) && (0 != ptp->tcWhile))
           )
         {
             mstiDesignatedOrTCpropagatingRootPort = true;
             break;
         }
     }
 
     prt->newInfo = prt->newInfo || cistDesignatedOrTCpropagatingRootPort;
     prt->newInfoMsti = prt->newInfoMsti
                        || mstiDesignatedOrTCpropagatingRootPort;
 
     PTSM_run(prt, false /* actual run */);
 }
 
 static void PTSM_to_IDLE(port_t *prt)
 {
     prt->PTSM_state = PTSM_IDLE;
 
     per_tree_port_t *cist = GET_CIST_PTP_FROM_PORT(prt);
     prt->helloWhen = cist->portTimes.Hello_Time;
 
     PTSM_run(prt, false /* actual run */);
 }
 
 static bool PTSM_run(port_t *prt, bool dry_run)
 {
    /* bool allTransmitReady; */
     per_tree_port_t *ptp;
     port_role_t cistRole;
     bool mstiMasterPort;
 
     if(!prt->portEnabled)
     {
         return PTSM_to_TRANSMIT_INIT(prt, false, dry_run);
     }
 
     switch(prt->PTSM_state)
     {
         case PTSM_TRANSMIT_INIT:
            /* return; */
         case PTSM_TRANSMIT_CONFIG:
            /* return; */
         case PTSM_TRANSMIT_TCN:
            /* return; */
         case PTSM_TRANSMIT_RSTP:
            /* return; */
         case PTSM_TRANSMIT_PERIODIC:
             if(dry_run) /* state change */
                 return true;
             PTSM_to_IDLE(prt); /* UnConditional Transition */
             return false;
         case PTSM_IDLE:
             /* allTransmitReady = true; */
             ptp = GET_CIST_PTP_FROM_PORT(prt);
             if(!ptp->selected || ptp->updtInfo)
             {
                 /* allTransmitReady = false; */
                 return false;
             }
             cistRole = ptp->role;
             mstiMasterPort = false;
             list_for_each_entry_continue(ptp, &prt->trees, port_list)
             {
                 if(!ptp->selected || ptp->updtInfo)
                 {
                     /* allTransmitReady = false; */
                     return false;
                 }
                 if(roleMaster == ptp->role)
                     mstiMasterPort = true;
             }
             if(0 == prt->helloWhen)
             {
                 if(dry_run) /* state change */
                     return true;
                 PTSM_to_TRANSMIT_PERIODIC(prt);
                 return false;
             }
             if(!(prt->txCount < prt->bridge->Transmit_Hold_Count))
                 return false;
 
             if(prt->bpduFilterPort)
                 return false;
 
             if(prt->sendRSTP)
             { /* implement MSTP */
                 if(prt->newInfo || (prt->newInfoMsti && !mstiMasterPort)
                    || assurancePort(prt)
                   )
                 {
                     if(dry_run) /* state change */
                         return true;
                     PTSM_to_TRANSMIT_RSTP(prt);
                     return false;
                 }
             }
             else
             { /* fallback to STP */
                 if(prt->newInfo && (roleDesignated == cistRole))
                 {
                     if(dry_run) /* state change */
                         return true;
                     PTSM_to_TRANSMIT_CONFIG(prt);
                     return false;
                 }
                 if(prt->newInfo && (roleRoot == cistRole))
                 {
                     if(dry_run) /* state change */
                         return true;
                     PTSM_to_TRANSMIT_TCN(prt);
                     return false;
                 }
             }
             return false;
     }
 
     return false;
 }
 
 /* 13.32  Port Information state machine */
 
 #ifdef PISM_ENABLE_LOG
 #define PISM_LOG(_fmt, _args...) SMLOG_MSTINAME(ptp, _fmt, ##_args)
 #else
 #define PISM_LOG(_fmt, _args...) {}
 #endif /* PISM_ENABLE_LOG */
 
 static bool PISM_run(per_tree_port_t *ptp, bool dry_run);
 #define PISM_begin(ptp) PISM_to_DISABLED((ptp), true)
 
 static void PISM_to_DISABLED(per_tree_port_t *ptp, bool begin)
 {
     PISM_LOG("");
     ptp->PISM_state = PISM_DISABLED;
 
     ptp->rcvdMsg = false;
     ptp->proposing = false;
     ptp->proposed = false;
     ptp->agree = false;
     ptp->agreed = false;
     assign(ptp->rcvdInfoWhile, 0u);
     ptp->infoIs = ioDisabled;
     ptp->reselect = true;
     ptp->selected = false;
 
     if(!begin)
         PISM_run(ptp, false /* actual run */);
 }
 
 static void PISM_to_AGED(per_tree_port_t *ptp)
 {
     PISM_LOG("");
     ptp->PISM_state = PISM_AGED;
 
     ptp->infoIs = ioAged;
     ptp->reselect = true;
     ptp->selected = false;
 
     PISM_run(ptp, false /* actual run */);
 }
 
 static void PISM_to_UPDATE(per_tree_port_t *ptp)
 {
     PISM_LOG("");
     ptp->PISM_state = PISM_UPDATE;
 
     ptp->proposing = false;
     ptp->proposed = false;
     ptp->agreed = ptp->agreed && betterorsameInfo(ptp, ioMine);
     ptp->synced = ptp->synced && ptp->agreed;
     assign(ptp->portPriority, ptp->designatedPriority);
     assign(ptp->portTimes, ptp->designatedTimes);
     ptp->updtInfo = false;
     ptp->infoIs = ioMine;
     /* newInfoXst = TRUE; */
     port_t *prt = ptp->port;
     if(0 == ptp->MSTID)
         prt->newInfo = true;
     else
         prt->newInfoMsti = true;
 
     PISM_run(ptp, false /* actual run */);
 }
 
 static void PISM_to_SUPERIOR_DESIGNATED(per_tree_port_t *ptp)
 {
     PISM_LOG("");
     ptp->PISM_state = PISM_SUPERIOR_DESIGNATED;
 
     port_t *prt = ptp->port;
 
     prt->infoInternal = prt->rcvdInternal;
     ptp->agreed = false;
     ptp->proposing = false;
     recordProposal(ptp);
     setTcFlags(ptp);
     ptp->agree = ptp->agree && betterorsameInfo(ptp, ioReceived);
     recordAgreement(ptp);
     ptp->synced = ptp->synced && ptp->agreed;
     recordPriority(ptp);
     recordTimes(ptp);
     updtRcvdInfoWhile(ptp);
     ptp->infoIs = ioReceived;
     ptp->reselect = true;
     ptp->selected = false;
     ptp->rcvdMsg = false;
 
     PISM_run(ptp, false /* actual run */);
 }
 
 static void PISM_to_REPEATED_DESIGNATED(per_tree_port_t *ptp)
 {
     PISM_LOG("");
     ptp->PISM_state = PISM_REPEATED_DESIGNATED;
 
     port_t *prt = ptp->port;
 
     prt->infoInternal = prt->rcvdInternal;
     recordProposal(ptp);
     setTcFlags(ptp);
     recordAgreement(ptp);
     updtRcvdInfoWhile(ptp);
     ptp->rcvdMsg = false;
 
     PISM_run(ptp, false /* actual run */);
 }
 
 static void PISM_to_INFERIOR_DESIGNATED(per_tree_port_t *ptp)
 {
     PISM_LOG("");
     ptp->PISM_state = PISM_INFERIOR_DESIGNATED;
 
     recordDispute(ptp);
     ptp->rcvdMsg = false;
 
     PISM_run(ptp, false /* actual run */);
 }
 
 static void PISM_to_NOT_DESIGNATED(per_tree_port_t *ptp)
 {
     PISM_LOG("");
     ptp->PISM_state = PISM_NOT_DESIGNATED;
 
     recordAgreement(ptp);
     setTcFlags(ptp);
     ptp->rcvdMsg = false;
 
     PISM_run(ptp, false /* actual run */);
 }
 
 static void PISM_to_OTHER(per_tree_port_t *ptp)
 {
     PISM_LOG("");
     ptp->PISM_state = PISM_OTHER;
 
     ptp->rcvdMsg = false;
 
     PISM_run(ptp, false /* actual run */);
 }
 
 static void PISM_to_CURRENT(per_tree_port_t *ptp)
 {
     PISM_LOG("");
     ptp->PISM_state = PISM_CURRENT;
 
     PISM_run(ptp, false /* actual run */);
 }
 
 static void PISM_to_RECEIVE(per_tree_port_t *ptp)
 {
     PISM_LOG("");
     ptp->PISM_state = PISM_RECEIVE;
 
     ptp->rcvdInfo = rcvInfo(ptp);
     recordMastered(ptp);
 
     PISM_run(ptp, false /* actual run */);
 }
 
 static bool PISM_run(per_tree_port_t *ptp, bool dry_run)
 {
     bool rcvdXstMsg, updtXstInfo;
     port_t *prt = ptp->port;
 
     if((!prt->portEnabled) && (ioDisabled != ptp->infoIs))
     {
         if(dry_run) /* at least infoIs will change */
             return true;
         PISM_to_DISABLED(ptp, false);
         return false;
     }
 
     switch(ptp->PISM_state)
     {
         case PISM_DISABLED:
             if(prt->portEnabled)
             {
                 if(dry_run) /* state change */
                     return true;
                 PISM_to_AGED(ptp);
                 return false;
             }
             if(ptp->rcvdMsg)
             {
                 if(dry_run) /* at least rcvdMsg will change */
                     return true;
                 PISM_to_DISABLED(ptp, false);
             }
             return false;
         case PISM_AGED:
             if(ptp->selected && ptp->updtInfo)
             {
                 if(dry_run) /* state change */
                     return true;
                 PISM_to_UPDATE(ptp);
             }
             return false;
         case PISM_UPDATE:
             /* return; */
         case PISM_SUPERIOR_DESIGNATED:
             /* return; */
         case PISM_REPEATED_DESIGNATED:
             /* return; */
         case PISM_INFERIOR_DESIGNATED:
             /* return; */
         case PISM_NOT_DESIGNATED:
             /* return; */
         case PISM_OTHER:
             if(dry_run) /* state change */
                 return true;
             PISM_to_CURRENT(ptp);
             return false;
         case PISM_CURRENT:
             /*
              * Although 802.1Q-2005 does not define rcvdXstMsg and updtXstInfo
              *  from 802.1s we can conclude that they are:
              *  - rcvdXstMsg = rcvdCistMsg, if tree is CIST
              *                 rcvdMstiMsg, if tree is MSTI.
              *  - updtXstInfo = updtCistInfo, if tree is CIST
              *                  updtMstiInfo, if tree is MSTI.
              */
             if(0 == ptp->MSTID)
             { /* CIST */
                 rcvdXstMsg = ptp->rcvdMsg; /* 13.25.12 */
                 updtXstInfo = ptp->updtInfo; /* 13.25.16 */
             }
             else
             { /* MSTI */
                 per_tree_port_t *cist = GET_CIST_PTP_FROM_PORT(prt);
                 rcvdXstMsg = !cist->rcvdMsg && ptp->rcvdMsg; /* 13.25.13 */
                 updtXstInfo = ptp->updtInfo || cist->updtInfo; /* 13.25.17 */
             }
             if(rcvdXstMsg && !updtXstInfo)
             {
                 if(dry_run) /* state change */
                     return true;
                 PISM_to_RECEIVE(ptp);
                 return false;
             }
             if((ioReceived == ptp->infoIs) && (0 == ptp->rcvdInfoWhile)
                && !ptp->updtInfo && !rcvdXstMsg)
             {
                 if(dry_run) /* state change */
                     return true;
                 PISM_to_AGED(ptp);
                 return false;
             }
             if(ptp->selected && ptp->updtInfo)
             {
                 if(dry_run) /* state change */
                     return true;
                 PISM_to_UPDATE(ptp);
             }
             return false;
         case PISM_RECEIVE:
             switch(ptp->rcvdInfo)
             {
                 case SuperiorDesignatedInfo:
                     if(dry_run) /* state change */
                         return true;
                     PISM_to_SUPERIOR_DESIGNATED(ptp);
                     return false;
                 case RepeatedDesignatedInfo:
                     if(dry_run) /* state change */
                         return true;
                     PISM_to_REPEATED_DESIGNATED(ptp);
                     return false;
                 case InferiorDesignatedInfo:
                     if(dry_run) /* state change */
                         return true;
                     PISM_to_INFERIOR_DESIGNATED(ptp);
                     return false;
                 case InferiorRootAlternateInfo:
                     if(dry_run) /* state change */
                         return true;
                     PISM_to_NOT_DESIGNATED(ptp);
                     return false;
                 case OtherInfo:
                     if(dry_run) /* state change */
                         return true;
                     PISM_to_OTHER(ptp);
                     return false;
             }
             return false;
     }
 
     return false;
 }
 
 /* 13.33  Port Role Selection state machine */
 
 static bool PRSSM_run(tree_t *tree, bool dry_run);
 #define PRSSM_begin(tree) PRSSM_to_INIT_TREE(tree)
 
 static void PRSSM_to_INIT_TREE(tree_t *tree/*, bool begin*/)
 {
     tree->PRSSM_state = PRSSM_INIT_TREE;
 
     updtRolesDisabledTree(tree);
 
     /* No need to check, as we assume begin = true here
      * because transition to this state can be initiated only by BEGIN var.
      * In other words, this function is called via xxx_begin macro only.
      * if(!begin)
      *     PRSSM_run(prt, false); */
 }
 
 static void PRSSM_to_ROLE_SELECTION(tree_t *tree)
 {
     tree->PRSSM_state = PRSSM_ROLE_SELECTION;
 
     clearReselectTree(tree);
     updtRolesTree(tree);
     setSelectedTree(tree);
 
     /* No need to run, no one condition will be met
       PRSSM_run(tree, false); */
 }
 
 static bool PRSSM_run(tree_t *tree, bool dry_run)
 {
     per_tree_port_t *ptp;
 
     switch(tree->PRSSM_state)
     {
         case PRSSM_INIT_TREE:
             if(dry_run) /* state change */
                 return true;
             PRSSM_to_ROLE_SELECTION(tree);
             return false;
         case PRSSM_ROLE_SELECTION:
             FOREACH_PTP_IN_TREE(ptp, tree)
                 if(ptp->reselect)
                 {
                     if(dry_run) /* at least reselect will change */
                         return true;
                     PRSSM_to_ROLE_SELECTION(tree);
                     return false;
                 }
             return false;
     }
 
     return false;
 }
 
 /* 13.34  Port Role Transitions state machine */
 
 #ifdef PRTSM_ENABLE_LOG
 #define PRTSM_LOG(_fmt, _args...) SMLOG_MSTINAME(ptp, _fmt, ##_args)
 #else
 #define PRTSM_LOG(_fmt, _args...) {}
 #endif /* PRTSM_ENABLE_LOG */
 
 static bool PRTSM_runr(per_tree_port_t *ptp, bool recursive_call, bool dry_run);
 #define PRTSM_run(ptp, dry_run) PRTSM_runr((ptp), false, (dry_run))
 #define PRTSM_begin(ptp) PRTSM_to_INIT_PORT(ptp)
 
  /* Disabled Port role transitions */
 
 static void PRTSM_to_INIT_PORT(per_tree_port_t *ptp/*, bool begin*/)
 {
     PRTSM_LOG("");
     ptp->PRTSM_state = PRTSM_INIT_PORT;
 
     unsigned int MaxAge, FwdDelay;
     per_tree_port_t *cist = GET_CIST_PTP_FROM_PORT(ptp->port);
 
     ptp->role = roleDisabled;
     ptp->learn = false;
     ptp->forward = false;
     ptp->synced = false;
     ptp->sync = true;
     ptp->reRoot = true;
     /* 13.25.6 */
     FwdDelay = cist->designatedTimes.Forward_Delay;
     assign(ptp->rrWhile, FwdDelay);
     /* 13.25.8 */
     MaxAge = cist->designatedTimes.Max_Age;
     assign(ptp->fdWhile, MaxAge);
     assign(ptp->rbWhile, 0u);
 
     /* No need to check, as we assume begin = true here
      * because transition to this state can be initiated only by BEGIN var.
      * In other words, this function is called via xxx_begin macro only.
      * if(!begin)
      *     PRTSM_runr(ptp, false, false); */
 }
 
 static void PRTSM_to_DISABLE_PORT(per_tree_port_t *ptp)
 {
     PRTSM_LOG("");
     ptp->PRTSM_state = PRTSM_DISABLE_PORT;
 
     /* Although 802.1Q-2005 says here to do role = selectedRole
      * I have difficulties with it in the next scenario:
      *  1) port was designated (role == selectedRole == roleDesignated)
      *  2) some config event occurs, e.g. MAC address changes and
      *     br_state_machines_begin is called
      *  3) role == selectedRole == roleDisabled, PRTSM_state = PRTSM_INIT_PORT
      * Because port was not actually down, on the next run
      *  Port Role Selection state machine sets selectedRole = roleDesignated
      *  and updtInfo = true:
      *  4) we have unconditional transition to DISABLE_PORT, and because
      *     updtInfo = true we can not follow transition to DESIGNATED_PORT
      *  5) if we follow standard, role = selectedRole = roleDesignated and
      *     on the next run we have transition to the DISABLED_PORT
      * And there we stuck. role == selectedRole, so we can not transit to
      *  DESIGNATED_PORT (it requires role != selectedRole ).
      *
      * Solution: do not follow the standard, and do role = roleDisabled
      *  instead of role = selectedRole.
      */
     ptp->role = roleDisabled;
     ptp->learn = false;
     ptp->forward = false;
 
     PRTSM_runr(ptp, true, false /* actual run */);
 }
 
 static void PRTSM_to_DISABLED_PORT(per_tree_port_t *ptp, unsigned int MaxAge)
 {
     PRTSM_LOG("");
     ptp->PRTSM_state = PRTSM_DISABLED_PORT;
 
     assign(ptp->fdWhile, MaxAge);
     ptp->synced = true;
     assign(ptp->rrWhile, 0u);
     ptp->sync = false;
     ptp->reRoot = false;
 
     PRTSM_runr(ptp, true, false /* actual run */);
 }
 
  /* MasterPort role transitions */
 
 static void PRTSM_to_MASTER_PROPOSED(per_tree_port_t *ptp)
 {
     PRTSM_LOG("");
     ptp->PRTSM_state = PRTSM_MASTER_PROPOSED;
 
     setSyncTree(ptp->tree);
     ptp->proposed = false;
 
     PRTSM_runr(ptp, true, false /* actual run */);
 }
 
 static void PRTSM_to_MASTER_AGREED(per_tree_port_t *ptp)
 {
     PRTSM_LOG("");
     ptp->PRTSM_state = PRTSM_MASTER_AGREED;
 
     ptp->proposed = false;
     ptp->sync = false;
     ptp->agree = true;
 
     PRTSM_runr(ptp, true, false /* actual run */);
 }
 
 static void PRTSM_to_MASTER_SYNCED(per_tree_port_t *ptp)
 {
     PRTSM_LOG("");
     ptp->PRTSM_state = PRTSM_MASTER_SYNCED;
 
     assign(ptp->rrWhile, 0u);
     ptp->synced = true;
     ptp->sync = false;
 
     PRTSM_runr(ptp, true, false /* actual run */);
 }
 
 static void PRTSM_to_MASTER_RETIRED(per_tree_port_t *ptp)
 {
     PRTSM_LOG("");
     ptp->PRTSM_state = PRTSM_MASTER_RETIRED;
 
     ptp->reRoot = false;
 
     PRTSM_runr(ptp, true, false /* actual run */);
 }
 
 static void PRTSM_to_MASTER_FORWARD(per_tree_port_t *ptp)
 {
     PRTSM_LOG("");
     ptp->PRTSM_state = PRTSM_MASTER_FORWARD;
 
     ptp->forward = true;
     assign(ptp->fdWhile, 0u);
     ptp->agreed = ptp->port->sendRSTP;
 
     PRTSM_runr(ptp, true, false /* actual run */);
 }
 
 static void PRTSM_to_MASTER_LEARN(per_tree_port_t *ptp, unsigned int forwardDelay)
 {
     PRTSM_LOG("");
     ptp->PRTSM_state = PRTSM_MASTER_LEARN;
 
     ptp->learn = true;
     assign(ptp->fdWhile, forwardDelay);
 
     PRTSM_runr(ptp, true, false /* actual run */);
 }
 
 static void PRTSM_to_MASTER_DISCARD(per_tree_port_t *ptp, unsigned int forwardDelay)
 {
     PRTSM_LOG("");
     ptp->PRTSM_state = PRTSM_MASTER_DISCARD;
 
     ptp->learn = false;
     ptp->forward = false;
     ptp->disputed = false;
     assign(ptp->fdWhile, forwardDelay);
 
     PRTSM_runr(ptp, true, false /* actual run */);
 }
 
 static void PRTSM_to_MASTER_PORT(per_tree_port_t *ptp)
 {
     PRTSM_LOG("");
     ptp->PRTSM_state = PRTSM_MASTER_PORT;
 
     ptp->role = roleMaster;
 
     PRTSM_runr(ptp, true, false /* actual run */);
 }
 
  /* RootPort role transitions */
 
 static void PRTSM_to_ROOT_PROPOSED(per_tree_port_t *ptp)
 {
     PRTSM_LOG("");
     ptp->PRTSM_state = PRTSM_ROOT_PROPOSED;
 
     setSyncTree(ptp->tree);
     ptp->proposed = false;
 
     PRTSM_runr(ptp, true, false /* actual run */);
 }
 
 static void PRTSM_to_ROOT_AGREED(per_tree_port_t *ptp)
 {
     PRTSM_LOG("");
     ptp->PRTSM_state = PRTSM_ROOT_AGREED;
 
     ptp->proposed = false;
     ptp->sync = false;
     ptp->agree = true;
     /* newInfoXst = TRUE; */
     port_t *prt = ptp->port;
     if(0 == ptp->MSTID)
         prt->newInfo = true;
     else
         prt->newInfoMsti = true;
 
     PRTSM_runr(ptp, true, false /* actual run */);
 }
 
 static void PRTSM_to_ROOT_SYNCED(per_tree_port_t *ptp)
 {
     PRTSM_LOG("");
     ptp->PRTSM_state = PRTSM_ROOT_SYNCED;
 
     ptp->synced = true;
     ptp->sync = false;
 
     PRTSM_runr(ptp, true, false /* actual run */);
 }
 
 static void PRTSM_to_REROOT(per_tree_port_t *ptp)
 {
     PRTSM_LOG("");
     ptp->PRTSM_state = PRTSM_REROOT;
 
     setReRootTree(ptp->tree);
 
     PRTSM_runr(ptp, true, false /* actual run */);
 }
 
 static void PRTSM_to_ROOT_FORWARD(per_tree_port_t *ptp)
 {
     PRTSM_LOG("");
     ptp->PRTSM_state = PRTSM_ROOT_FORWARD;
 
     assign(ptp->fdWhile, 0u);
     ptp->forward = true;
 
     PRTSM_runr(ptp, true, false /* actual run */);
 }
 
 static void PRTSM_to_ROOT_LEARN(per_tree_port_t *ptp, unsigned int forwardDelay)
 {
     PRTSM_LOG("");
     ptp->PRTSM_state = PRTSM_ROOT_LEARN;
 
     assign(ptp->fdWhile, forwardDelay);
     ptp->learn = true;
 
     PRTSM_runr(ptp, true, false /* actual run */);
 }
 
 static void PRTSM_to_REROOTED(per_tree_port_t *ptp)
 {
     PRTSM_LOG("");
     ptp->PRTSM_state = PRTSM_REROOTED;
 
     ptp->reRoot = false;
 
     PRTSM_runr(ptp, true, false /* actual run */);
 }
 
 static void PRTSM_to_ROOT_PORT(per_tree_port_t *ptp, unsigned int FwdDelay)
 {
     PRTSM_LOG("");
     ptp->PRTSM_state = PRTSM_ROOT_PORT;
 
     ptp->role = roleRoot;
     assign(ptp->rrWhile, FwdDelay);
 
     PRTSM_runr(ptp, true, false /* actual run */);
 }
 
  /* DesignatedPort role transitions */
 
 static void PRTSM_to_DESIGNATED_PROPOSE(per_tree_port_t *ptp)
 {
     PRTSM_LOG("");
     ptp->PRTSM_state = PRTSM_DESIGNATED_PROPOSE;
 
     port_t *prt = ptp->port;
 
     ptp->proposing = true;
     /* newInfoXst = TRUE; */
     if(0 == ptp->MSTID)
     { /* CIST */
         /* 13.25.8. This tree is CIST. */
         unsigned int MaxAge = ptp->designatedTimes.Max_Age;
         /* 13.25.c) -> 17.20.4 of 802.1D : EdgeDelay */
         unsigned int EdgeDelay = prt->operPointToPointMAC ?
                                    prt->bridge->Migrate_Time
                                  : MaxAge;
         assign(prt->edgeDelayWhile, EdgeDelay);
         prt->newInfo = true;
     }
     else
         prt->newInfoMsti = true;
 
     PRTSM_runr(ptp, true, false /* actual run */);
 }
 
 static void PRTSM_to_DESIGNATED_AGREED(per_tree_port_t *ptp)
 {
     PRTSM_LOG("");
     ptp->PRTSM_state = PRTSM_DESIGNATED_AGREED;
 
     ptp->proposed = false;
     ptp->sync = false;
     ptp->agree = true;
     /* newInfoXst = TRUE; */
     port_t *prt = ptp->port;
     if(0 == ptp->MSTID)
         prt->newInfo = true;
     else
         prt->newInfoMsti = true;
 
     PRTSM_runr(ptp, true, false /* actual run */);
 }
 
 static void PRTSM_to_DESIGNATED_SYNCED(per_tree_port_t *ptp)
 {
     PRTSM_LOG("");
     ptp->PRTSM_state = PRTSM_DESIGNATED_SYNCED;
 
     assign(ptp->rrWhile, 0u);
     ptp->synced = true;
     ptp->sync = false;
 
     PRTSM_runr(ptp, true, false /* actual run */);
 }
 
 static void PRTSM_to_DESIGNATED_RETIRED(per_tree_port_t *ptp)
 {
     PRTSM_LOG("");
     ptp->PRTSM_state = PRTSM_DESIGNATED_RETIRED;
 
     ptp->reRoot = false;
 
     PRTSM_runr(ptp, true, false /* actual run */);
 }
 
 static void PRTSM_to_DESIGNATED_FORWARD(per_tree_port_t *ptp)
 {
     PRTSM_LOG("");
     ptp->PRTSM_state = PRTSM_DESIGNATED_FORWARD;
 
     ptp->forward = true;
     assign(ptp->fdWhile, 0u);
     ptp->agreed = ptp->port->sendRSTP;
 
     PRTSM_runr(ptp, true, false /* actual run */);
 }
 
 static void PRTSM_to_DESIGNATED_LEARN(per_tree_port_t *ptp, unsigned int forwardDelay)
 {
     PRTSM_LOG("");
     ptp->PRTSM_state = PRTSM_DESIGNATED_LEARN;
 
     ptp->learn = true;
     assign(ptp->fdWhile, forwardDelay);
 
     PRTSM_runr(ptp, true, false /* actual run */);
 }
 
 static void PRTSM_to_DESIGNATED_DISCARD(per_tree_port_t *ptp, unsigned int forwardDelay)
 {
     PRTSM_LOG("");
     ptp->PRTSM_state = PRTSM_DESIGNATED_DISCARD;
 
     ptp->learn = false;
     ptp->forward = false;
     ptp->disputed = false;
     assign(ptp->fdWhile, forwardDelay);
 
     PRTSM_runr(ptp, true, false /* actual run */);
 }
 
 static void PRTSM_to_DESIGNATED_PORT(per_tree_port_t *ptp)
 {
     PRTSM_LOG("");
     ptp->PRTSM_state = PRTSM_DESIGNATED_PORT;
 
     ptp->role = roleDesignated;
 
     PRTSM_runr(ptp, true, false /* actual run */);
 }
 
  /* AlternatePort and BackupPort role transitions */
 
 static void PRTSM_to_BLOCK_PORT(per_tree_port_t *ptp)
 {
     PRTSM_LOG("");
     ptp->PRTSM_state = PRTSM_BLOCK_PORT;
 
     ptp->role = ptp->selectedRole;
     ptp->learn = false;
     ptp->forward = false;
 
     PRTSM_runr(ptp, true, false /* actual run */);
 }
 
 static void PRTSM_to_BACKUP_PORT(per_tree_port_t *ptp, unsigned int HelloTime)
 {
     PRTSM_LOG("");
     ptp->PRTSM_state = PRTSM_BACKUP_PORT;
 
     assign(ptp->rbWhile, 2 * HelloTime);
 
     PRTSM_runr(ptp, true, false /* actual run */);
 }
 
 static void PRTSM_to_ALTERNATE_PROPOSED(per_tree_port_t *ptp)
 {
     PRTSM_LOG("");
     ptp->PRTSM_state = PRTSM_ALTERNATE_PROPOSED;
 
     setSyncTree(ptp->tree);
     ptp->proposed = false;
 
     PRTSM_runr(ptp, true, false /* actual run */);
 }
 
 static void PRTSM_to_ALTERNATE_AGREED(per_tree_port_t *ptp)
 {
     PRTSM_LOG("");
     ptp->PRTSM_state = PRTSM_ALTERNATE_AGREED;
 
     ptp->proposed = false;
     ptp->agree = true;
     /* newInfoXst = TRUE; */
     port_t *prt = ptp->port;
     if(0 == ptp->MSTID)
         prt->newInfo = true;
     else
         prt->newInfoMsti = true;
 
     PRTSM_runr(ptp, true, false /* actual run */);
 }
 
 static void PRTSM_to_ALTERNATE_PORT(per_tree_port_t *ptp, unsigned int forwardDelay)
 {
     PRTSM_LOG("");
     ptp->PRTSM_state = PRTSM_ALTERNATE_PORT;
 
     assign(ptp->fdWhile, forwardDelay);
     ptp->synced = true;
     assign(ptp->rrWhile, 0u);
     ptp->sync = false;
     ptp->reRoot = false;
 
     PRTSM_runr(ptp, true, false /* actual run */);
 }
 
 static bool PRTSM_runr(per_tree_port_t *ptp, bool recursive_call, bool dry_run)
 {
     /* Following vars do not need recalculating on recursive calls */
     static unsigned int MaxAge, FwdDelay, forwardDelay, HelloTime;
     static port_t *prt;
     static tree_t *tree;
     static per_tree_port_t *cist;
     /* Following vars are recalculated on each state transition */
     bool allSynced, reRooted;
     /* Following vars are auxiliary and don't depend on recursive_call */
     per_tree_port_t *ptp_1;
 
     if(!recursive_call)
     { /* calculate these intermediate vars only first time in chain of
        * recursive calls */
         prt = ptp->port;
         tree = ptp->tree;
 
         cist = GET_CIST_PTP_FROM_PORT(prt);
 
         /* 13.25.6 */
         FwdDelay = cist->designatedTimes.Forward_Delay;
 
         /* 13.25.7 */
         HelloTime = cist->portTimes.Hello_Time;
 
         /* 13.25.d) -> 17.20.5 of 802.1D */
         forwardDelay = prt->sendRSTP ? HelloTime : FwdDelay;
 
         /* 13.25.8 */
         MaxAge = cist->designatedTimes.Max_Age;
     }
 
     PRTSM_LOG("role = %d, selectedRole = %d, selected = %d, updtInfo = %d",
               ptp->role, ptp->selectedRole, ptp->selected, ptp->updtInfo);
     if((ptp->role != ptp->selectedRole) && ptp->selected && !ptp->updtInfo)
     {
         switch(ptp->selectedRole)
         {
             case roleDisabled:
                 if(dry_run) /* at least role will change */
                     return true;
                 PRTSM_to_DISABLE_PORT(ptp);
                 return false;
             case roleMaster:
                 if(dry_run) /* at least role will change */
                     return true;
                 PRTSM_to_MASTER_PORT(ptp);
                 return false;
             case roleRoot:
                 if(dry_run) /* at least role will change */
                     return true;
                 PRTSM_to_ROOT_PORT(ptp, FwdDelay);
                 return false;
             case roleDesignated:
                 if(dry_run) /* at least role will change */
                     return true;
                 PRTSM_to_DESIGNATED_PORT(ptp);
                 return false;
             case roleAlternate:
             case roleBackup:
                 if(dry_run) /* at least role will change */
                     return true;
                 PRTSM_to_BLOCK_PORT(ptp);
                 return false;
         }
     }
 
     /* 13.25.1 */
     allSynced = true;
     FOREACH_PTP_IN_TREE(ptp_1, tree)
     {
         /* a) */
         if(!ptp_1->selected
            || (ptp_1->role != ptp_1->selectedRole)
            || ptp_1->updtInfo
           )
         {
             allSynced = false;
             break;
         }
 
         /* b) */
         switch(ptp->role)
         {
             case roleRoot:
             case roleAlternate:
                 if((roleRoot != ptp_1->role) && !ptp_1->synced)
                     allSynced = false;
                 break;
             case roleDesignated:
             case roleMaster:
                 if((ptp != ptp_1) && !ptp_1->synced)
                     allSynced = false;
                 break;
             default:
                 allSynced = false;
         }
         if(!allSynced)
             break;
     }
 
     switch(ptp->PRTSM_state)
     {
      /* Disabled Port role transitions */
         case PRTSM_INIT_PORT:
             if(dry_run) /* state change */
                 return true;
             PRTSM_to_DISABLE_PORT(ptp);
             return false;
         case PRTSM_DISABLE_PORT:
             if(ptp->selected && !ptp->updtInfo
                && !ptp->learning && !ptp->forwarding
               )
             {
                 if(dry_run) /* state change */
                     return true;
                 PRTSM_to_DISABLED_PORT(ptp, MaxAge);
             }
             return false;
         case PRTSM_DISABLED_PORT:
             if(ptp->selected && !ptp->updtInfo
                && (ptp->sync || ptp->reRoot || !ptp->synced
                    || (ptp->fdWhile != MaxAge))
               )
             {
                 if(dry_run) /* one of (sync,reRoot,synced,fdWhile) will change */
                     return true;
                 PRTSM_to_DISABLED_PORT(ptp, MaxAge);
             }
             return false;
      /* MasterPort role transitions */
         case PRTSM_MASTER_PROPOSED:
             /* return; */
         case PRTSM_MASTER_AGREED:
             /* return; */
         case PRTSM_MASTER_SYNCED:
             /* return; */
         case PRTSM_MASTER_RETIRED:
             /* return; */
         case PRTSM_MASTER_FORWARD:
             /* return; */
         case PRTSM_MASTER_LEARN:
             /* return; */
         case PRTSM_MASTER_DISCARD:
             if(dry_run) /* state change */
                 return true;
             PRTSM_to_MASTER_PORT(ptp);
             return false;
         case PRTSM_MASTER_PORT:
             if(!(ptp->selected && !ptp->updtInfo))
                 return false;
             if(ptp->reRoot && (0 == ptp->rrWhile))
             {
                 if(dry_run) /* state change */
                     return true;
                 PRTSM_to_MASTER_RETIRED(ptp);
                 return false;
             }
             if((!ptp->learning && !ptp->forwarding && !ptp->synced)
                || (ptp->agreed && !ptp->synced)
                || (prt->operEdge && !ptp->synced)
                || (ptp->sync && ptp->synced)
               )
             {
                 if(dry_run) /* state change */
                     return true;
                 PRTSM_to_MASTER_SYNCED(ptp);
                 return false;
             }
             if((allSynced && !ptp->agree)
                || (ptp->proposed && ptp->agree)
               )
             {
                 if(dry_run) /* state change */
                     return true;
                 PRTSM_to_MASTER_AGREED(ptp);
                 return false;
             }
             if(ptp->proposed && !ptp->agree)
             {
                 if(dry_run) /* state change */
                     return true;
                 PRTSM_to_MASTER_PROPOSED(ptp);
                 return false;
             }
             if(((0 == ptp->fdWhile) || allSynced)
                && ptp->learn && !ptp->forward
               )
             {
                 if(dry_run) /* state change */
                     return true;
                 PRTSM_to_MASTER_FORWARD(ptp);
                 return false;
             }
             if(((0 == ptp->fdWhile) || allSynced)
                && !ptp->learn
               )
             {
                 if(dry_run) /* state change */
                     return true;
                 PRTSM_to_MASTER_LEARN(ptp, forwardDelay);
                 return false;
             }
             if(((ptp->sync && !ptp->synced)
                 || (ptp->reRoot && (0 != ptp->rrWhile))
                 || ptp->disputed
                )
                && !prt->operEdge && (ptp->learn || ptp->forward)
               )
             {
                 if(dry_run) /* state change */
                     return true;
                 PRTSM_to_MASTER_DISCARD(ptp, forwardDelay);
                 return false;
             }
             return false;
      /* RootPort role transitions */
         case PRTSM_ROOT_PROPOSED:
             /* return; */
         case PRTSM_ROOT_AGREED:
             /* return; */
         case PRTSM_ROOT_SYNCED:
             /* return; */
         case PRTSM_REROOT:
             /* return; */
         case PRTSM_ROOT_FORWARD:
             /* return; */
         case PRTSM_ROOT_LEARN:
             /* return; */
         case PRTSM_REROOTED:
             if(dry_run) /* state change */
                 return true;
             PRTSM_to_ROOT_PORT(ptp, FwdDelay);
             return false;
         case PRTSM_ROOT_PORT:
             if(!(ptp->selected && !ptp->updtInfo))
                 return false;
             if(!ptp->forward && !ptp->reRoot)
             {
                 if(dry_run) /* state change */
                     return true;
                 PRTSM_to_REROOT(ptp);
                 return false;
             }
             if((ptp->agreed && !ptp->synced) || (ptp->sync && ptp->synced))
             {
                 if(dry_run) /* state change */
                     return true;
                 PRTSM_to_ROOT_SYNCED(ptp);
                 return false;
             }
             if((allSynced && !ptp->agree) || (ptp->proposed && ptp->agree))
             {
                 if(dry_run) /* state change */
                     return true;
                 PRTSM_to_ROOT_AGREED(ptp);
                 return false;
             }
             if(ptp->proposed && !ptp->agree)
             {
                 if(dry_run) /* state change */
                     return true;
                 PRTSM_to_ROOT_PROPOSED(ptp);
                 return false;
             }
             /* 17.20.10 of 802.1D : reRooted */
             reRooted = true;
             FOREACH_PTP_IN_TREE(ptp_1, tree)
             {
                 if((ptp != ptp_1) && (0 != ptp_1->rrWhile))
                 {
                     reRooted = false;
                     break;
                 }
             }
             if((0 == ptp->fdWhile)
                || (reRooted && (0 == ptp->rbWhile) && rstpVersion(prt->bridge))
               )
             {
                 if(!ptp->learn)
                 {
                     if(dry_run) /* state change */
                         return true;
                     PRTSM_to_ROOT_LEARN(ptp, forwardDelay);
                     return false;
                 }
                 else if(!ptp->forward)
                 {
                     if(dry_run) /* state change */
                         return true;
                     PRTSM_to_ROOT_FORWARD(ptp);
                     return false;
                 }
             }
             if(ptp->reRoot && ptp->forward)
             {
                 if(dry_run) /* state change */
                     return true;
                 PRTSM_to_REROOTED(ptp);
                 return false;
             }
             if(ptp->rrWhile != FwdDelay)
             {
                 if(dry_run) /* state change */
                     return true;
                 PRTSM_to_ROOT_PORT(ptp, FwdDelay);
                 return false;
             }
             return false;
      /* DesignatedPort role transitions */
         case PRTSM_DESIGNATED_PROPOSE:
             /* return; */
         case PRTSM_DESIGNATED_AGREED:
             /* return; */
         case PRTSM_DESIGNATED_SYNCED:
             /* return; */
         case PRTSM_DESIGNATED_RETIRED:
             /* return; */
         case PRTSM_DESIGNATED_FORWARD:
             /* return; */
         case PRTSM_DESIGNATED_LEARN:
             /* return; */
         case PRTSM_DESIGNATED_DISCARD:
             if(dry_run) /* state change */
                 return true;
             PRTSM_to_DESIGNATED_PORT(ptp);
             return false;
         case PRTSM_DESIGNATED_PORT:
             if(!(ptp->selected && !ptp->updtInfo))
                 return false;
             if(ptp->reRoot && (0 == ptp->rrWhile))
             {
                 if(dry_run) /* state change */
                     return true;
                 PRTSM_to_DESIGNATED_RETIRED(ptp);
                 return false;
             }
             if((!ptp->learning && !ptp->forwarding && !ptp->synced)
                || (ptp->agreed && !ptp->synced)
                || (prt->operEdge && !ptp->synced)
                || (ptp->sync && ptp->synced)
               )
             {
                 if(dry_run) /* state change */
                     return true;
                 PRTSM_to_DESIGNATED_SYNCED(ptp);
                 return false;
             }
             if(allSynced && (ptp->proposed || !ptp->agree))
             {
                 if(dry_run) /* state change */
                     return true;
                 PRTSM_to_DESIGNATED_AGREED(ptp);
                 return false;
             }
             if(!ptp->forward && !ptp->agreed && !ptp->proposing
                && !prt->operEdge)
             {
                 if(dry_run) /* state change */
                     return true;
                 PRTSM_to_DESIGNATED_PROPOSE(ptp);
                 return false;
             }
             /* Dont transition to learn/forward when BA inconsistent */
             if(((0 == ptp->fdWhile) || ptp->agreed || prt->operEdge)
                && ((0 == ptp->rrWhile) || !ptp->reRoot) && !ptp->sync
                && !ptp->port->BaInconsistent
               )
             {
                 if(!ptp->learn)
                 {
                     if(dry_run) /* state change */
                         return true;
                     PRTSM_to_DESIGNATED_LEARN(ptp, forwardDelay);
                     return false;
                 }
                 else if(!ptp->forward)
                 {
                     if(dry_run) /* state change */
                         return true;
                     PRTSM_to_DESIGNATED_FORWARD(ptp);
                     return false;
                 }
             }
             /* Transition to discarding when BA inconsistent */
             if(((ptp->sync && !ptp->synced)
                 || (ptp->reRoot && (0 != ptp->rrWhile))
                 || ptp->disputed
                 || ptp->port->BaInconsistent
                )
                && !prt->operEdge && (ptp->learn || ptp->forward)
               )
             {
                 if(dry_run) /* state change */
                     return true;
                 PRTSM_to_DESIGNATED_DISCARD(ptp, forwardDelay);
                 return false;
             }
             return false;
      /* AlternatePort and BackupPort role transitions */
         case PRTSM_BLOCK_PORT:
             if(ptp->selected && !ptp->updtInfo
                && !ptp->learning && !ptp->forwarding
               )
             {
                 if(dry_run) /* state change */
                     return true;
                 PRTSM_to_ALTERNATE_PORT(ptp, forwardDelay);
             }
             return false;
         case PRTSM_BACKUP_PORT:
             /* return; */
         case PRTSM_ALTERNATE_PROPOSED:
             /* return; */
         case PRTSM_ALTERNATE_AGREED:
             if(dry_run) /* state change */
                 return true;
             PRTSM_to_ALTERNATE_PORT(ptp, forwardDelay);
             return false;
         case PRTSM_ALTERNATE_PORT:
             if(!(ptp->selected && !ptp->updtInfo))
                 return false;
             if((allSynced && !ptp->agree) || (ptp->proposed && ptp->agree))
             {
                 if(dry_run) /* state change */
                     return true;
                 PRTSM_to_ALTERNATE_AGREED(ptp);
                 return false;
             }
             if(ptp->proposed && !ptp->agree)
             {
                 if(dry_run) /* state change */
                     return true;
                 PRTSM_to_ALTERNATE_PROPOSED(ptp);
                 return false;
             }
             if((ptp->rbWhile != 2 * HelloTime) && (roleBackup == ptp->role))
             {
                 if(dry_run) /* state change */
                     return true;
                 PRTSM_to_BACKUP_PORT(ptp, HelloTime);
                 return false;
             }
             if((ptp->fdWhile != forwardDelay) || ptp->sync || ptp->reRoot
                || !ptp->synced)
             {
                 if(dry_run) /* state change */
                     return true;
                 PRTSM_to_ALTERNATE_PORT(ptp, forwardDelay);
                 return false;
             }
             return false;
     }
 
     return false;
 }
 
 /* 13.35  Port State Transition state machine */
 
 static bool PSTSM_run(per_tree_port_t *ptp, bool dry_run);
 #define PSTSM_begin(ptp) PSTSM_to_DISCARDING((ptp), true)
 
 static void PSTSM_to_DISCARDING(per_tree_port_t *ptp, bool begin)
 {
     ptp->PSTSM_state = PSTSM_DISCARDING;
 
     /* This effectively sets BLOCKING state:
     disableLearning();
     disableForwarding();
     */
     if(BR_STATE_BLOCKING != ptp->state)
     {
         if(!ptp->port->deleted)
             MSTP_OUT_set_state(ptp, BR_STATE_BLOCKING);
     }
     ptp->learning = false;
     ptp->forwarding = false;
 
     if(!begin)
         PSTSM_run(ptp, false /* actual run */);
 }
 
 static void PSTSM_to_LEARNING(per_tree_port_t *ptp)
 {
     ptp->PSTSM_state = PSTSM_LEARNING;
 
     /* enableLearning(); */
     if(BR_STATE_LEARNING != ptp->state)
     {
         if(!ptp->port->deleted)
             MSTP_OUT_set_state(ptp, BR_STATE_LEARNING);
     }
     ptp->learning = true;
 
     PSTSM_run(ptp, false /* actual run */);
 }
 
 static void PSTSM_to_FORWARDING(per_tree_port_t *ptp)
 {
     ptp->PSTSM_state = PSTSM_FORWARDING;
 
     /* enableForwarding(); */
     if(BR_STATE_FORWARDING != ptp->state)
     {
         if(!ptp->port->deleted)
             MSTP_OUT_set_state(ptp, BR_STATE_FORWARDING);
     }
     ptp->forwarding = true;
 
     /* No need to run, no one condition will be met
       PSTSM_run(ptp, false); */
 }
 
 static bool PSTSM_run(per_tree_port_t *ptp, bool dry_run)
 {
     switch(ptp->PSTSM_state)
     {
         case PSTSM_DISCARDING:
             if(ptp->learn)
             {
                 if(dry_run) /* state change */
                     return true;
                 PSTSM_to_LEARNING(ptp);
             }
             return false;
         case PSTSM_LEARNING:
             if(!ptp->learn)
             {
                 if(dry_run) /* state change */
                     return true;
                 PSTSM_to_DISCARDING(ptp, false);
             }
             else if(ptp->forward)
             {
                 if(dry_run) /* state change */
                     return true;
                 PSTSM_to_FORWARDING(ptp);
             }
             return false;
         case PSTSM_FORWARDING:
             if(!ptp->forward)
             {
                 if(dry_run) /* state change */
                     return true;
                 PSTSM_to_DISCARDING(ptp, false);
             }
             return false;
     }
 
     return false;
 }
 
 /* 13.36  Topology Change state machine */
 
 #define TCSM_begin(ptp) TCSM_to_INACTIVE((ptp), true)
 
 static void TCSM_to_INACTIVE(per_tree_port_t *ptp, bool begin)
 {
     ptp->TCSM_state = TCSM_INACTIVE;
 
     set_fdbFlush(ptp);
     assign(ptp->tcWhile, 0u);
     set_TopologyChange(ptp->tree, false, ptp->port);
     if(0 == ptp->MSTID) /* CIST */
         ptp->port->tcAck = false;
 
     if(!begin)
         TCSM_run(ptp, false /* actual run */);
 }
 
 static bool TCSM_to_LEARNING(per_tree_port_t *ptp, bool dry_run)
 {
     if(dry_run)
     {
         if((ptp->TCSM_state != TCSM_LEARNING) || ptp->rcvdTc || ptp->tcProp)
             return true;
         if(0 == ptp->MSTID) /* CIST */
         {
             port_t *prt = ptp->port;
             if(prt->rcvdTcn || prt->rcvdTcAck)
                 return true;
         }
         return false;
     }
 
     ptp->TCSM_state = TCSM_LEARNING;
 
     if(0 == ptp->MSTID) /* CIST */
     {
         port_t *prt = ptp->port;
         prt->rcvdTcn = false;
         prt->rcvdTcAck = false;
     }
     ptp->rcvdTc = false;
     ptp->tcProp = false;
 
     TCSM_run(ptp, false /* actual run */);
     return false;
 }
 
 static void TCSM_to_DETECTED(per_tree_port_t *ptp)
 {
     ptp->TCSM_state = TCSM_DETECTED;
 
     newTcWhile(ptp);
     setTcPropTree(ptp);
     /* newInfoXst = TRUE; */
     port_t *prt = ptp->port;
     if(0 == ptp->MSTID)
         prt->newInfo = true;
     else
         prt->newInfoMsti = true;
 
     TCSM_run(ptp, false /* actual run */);
 }
 
 static void TCSM_to_NOTIFIED_TCN(per_tree_port_t *ptp)
 {
     ptp->TCSM_state = TCSM_NOTIFIED_TCN;
 
     newTcWhile(ptp);
 
     TCSM_run(ptp, false /* actual run */);
 }
 
 static void TCSM_to_NOTIFIED_TC(per_tree_port_t *ptp)
 {
     ptp->TCSM_state = TCSM_NOTIFIED_TC;
 
     ptp->rcvdTc = false;
     if(0 == ptp->MSTID) /* CIST */
     {
         port_t *prt = ptp->port;
         prt->rcvdTcn = false;
         if(roleDesignated == ptp->role)
             prt->tcAck = true;
     }
     setTcPropTree(ptp);
 
     TCSM_run(ptp, false /* actual run */);
 }
 
 static void TCSM_to_PROPAGATING(per_tree_port_t *ptp)
 {
     ptp->TCSM_state = TCSM_PROPAGATING;
 
     newTcWhile(ptp);
     set_fdbFlush(ptp);
     ptp->tcProp = false;
 
     TCSM_run(ptp, false /* actual run */);
 }
 
 static void TCSM_to_ACKNOWLEDGED(per_tree_port_t *ptp)
 {
     ptp->TCSM_state = TCSM_ACKNOWLEDGED;
 
     assign(ptp->tcWhile, 0u);
     set_TopologyChange(ptp->tree, false, ptp->port);
     ptp->port->rcvdTcAck = false;
 
     TCSM_run(ptp, false /* actual run */);
 }
 
 static void TCSM_to_ACTIVE(per_tree_port_t *ptp)
 {
     ptp->TCSM_state = TCSM_ACTIVE;
 
     TCSM_run(ptp, false /* actual run */);
 }
 
 static bool TCSM_run(per_tree_port_t *ptp, bool dry_run)
 {
     bool active_port;
     port_t *prt = ptp->port;
 
     switch(ptp->TCSM_state)
     {
         case TCSM_INACTIVE:
             if(ptp->learn && !ptp->fdbFlush)
             {
                 if(dry_run) /* state change */
                     return true;
                 TCSM_to_LEARNING(ptp, false /* actual run */);
             }
             return false;
         case TCSM_LEARNING:
             active_port = (roleRoot == ptp->role)
                           || (roleDesignated == ptp->role)
                           || (roleMaster == ptp->role);
             if(active_port && ptp->forward && !prt->operEdge)
             {
                 if(dry_run) /* state change */
                     return true;
                 TCSM_to_DETECTED(ptp);
                 return false;
             }
             if(ptp->rcvdTc || prt->rcvdTcn || prt->rcvdTcAck || ptp->tcProp)
             {
                 return TCSM_to_LEARNING(ptp, dry_run);
             }
             else if(!active_port && !(ptp->learn || ptp->learning))
             {
                 if(dry_run) /* state change */
                     return true;
                 TCSM_to_INACTIVE(ptp, false);
             }
             return false;
         case TCSM_NOTIFIED_TCN:
             if(dry_run) /* state change */
                 return true;
             TCSM_to_NOTIFIED_TC(ptp);
             return false;
         case TCSM_DETECTED:
             /* return; */
         case TCSM_NOTIFIED_TC:
             /* return; */
         case TCSM_PROPAGATING:
             /* return; */
         case TCSM_ACKNOWLEDGED:
             if(dry_run) /* state change */
                 return true;
             TCSM_to_ACTIVE(ptp);
             return false;
         case TCSM_ACTIVE:
             active_port = (roleRoot == ptp->role)
                           || (roleDesignated == ptp->role)
                           || (roleMaster == ptp->role);
             if(!active_port || prt->operEdge)
             {
                 if(dry_run) /* state change */
                     return true;
                 TCSM_to_LEARNING(ptp, false /* actual run */);
                 return false;
             }
             if(prt->rcvdTcn)
             {
                 if(dry_run) /* state change */
                     return true;
                 TCSM_to_NOTIFIED_TCN(ptp);
                 return false;
             }
             if(ptp->rcvdTc)
             {
                 if(dry_run) /* state change */
                     return true;
                 TCSM_to_NOTIFIED_TC(ptp);
                 return false;
             }
             if(ptp->tcProp/* && !prt->operEdge */)
             {
                 if(dry_run) /* state change */
                     return true;
                 TCSM_to_PROPAGATING(ptp);
                 return false;
             }
             if(prt->rcvdTcAck)
             {
                 if(dry_run) /* state change */
                     return true;
                 TCSM_to_ACKNOWLEDGED(ptp);
                 return false;
             }
             return false;
     }
 
     return false;
 }
 
 /* Execute BEGIN state. We do not define BEGIN variable
  * but instead xxx_state_machines_begin execute begin state
  * abd do one step out of it
  */
 
 static void tree_state_machines_begin(tree_t *tree)
 {
     bridge_t *br = tree->bridge;
     per_tree_port_t *ptp;
 
     if(!br->bridgeEnabled)
         return;
 
     /* 13.32  Port Information state machine */
     FOREACH_PTP_IN_TREE(ptp, tree)
     {
         ptp->start_time = br->uptime; /* 12.8.2.2.3 b) */
         PISM_begin(ptp);
     }
 
     /* 13.33  Port Role Selection state machine */
     PRSSM_begin(tree);
 
     /* 13.34  Port Role Transitions state machine */
     FOREACH_PTP_IN_TREE(ptp, tree)
         PRTSM_begin(ptp);
     /* 13.35  Port State Transition state machine */
     FOREACH_PTP_IN_TREE(ptp, tree)
         PSTSM_begin(ptp);
     /* 13.36  Topology Change state machine */
     FOREACH_PTP_IN_TREE(ptp, tree)
         TCSM_begin(ptp);
 
     br_state_machines_run(br);
 }
 
 static void prt_state_machines_begin(port_t *prt)
 {
     bridge_t *br = prt->bridge;
     tree_t *tree;
     per_tree_port_t *ptp;
 
     if(!br->bridgeEnabled)
         return;
 
     /* 13.28  Port Receive state machine */
     PRSM_begin(prt);
     /* 13.29  Port Protocol Migration state machine */
     PPMSM_begin(prt);
     /* 13.30  Bridge Detection state machine */
     BDSM_begin(prt);
     /* 13.31  Port Transmit state machine */
     PTSM_begin(prt);
 
     /* 13.32  Port Information state machine */
     FOREACH_PTP_IN_PORT(ptp, prt)
     {
         ptp->start_time = br->uptime; /* 12.8.2.2.3 b) */
         PISM_begin(ptp);
     }
 
     /* 13.33  Port Role Selection state machine */
     FOREACH_TREE_IN_BRIDGE(tree, br)
         PRSSM_run(tree, false /* actual run */);
 
     /* 13.34  Port Role Transitions state machine */
     FOREACH_PTP_IN_PORT(ptp, prt)
         PRTSM_begin(ptp);
     /* 13.35  Port State Transition state machine */
     FOREACH_PTP_IN_PORT(ptp, prt)
         PSTSM_begin(ptp);
     /* 13.36  Topology Change state machine */
     FOREACH_PTP_IN_PORT(ptp, prt)
         TCSM_begin(ptp);
 
     br_state_machines_run(br);
 }
 
 static void br_state_machines_begin(bridge_t *br)
 {
     port_t *prt;
     per_tree_port_t *ptp;
     tree_t *tree;
 
     if(!br->bridgeEnabled)
         return;
 
     /* 13.28  Port Receive state machine */
     FOREACH_PORT_IN_BRIDGE(prt, br)
         PRSM_begin(prt);
     /* 13.29  Port Protocol Migration state machine */
     FOREACH_PORT_IN_BRIDGE(prt, br)
         PPMSM_begin(prt);
     /* 13.30  Bridge Detection state machine */
     FOREACH_PORT_IN_BRIDGE(prt, br)
         BDSM_begin(prt);
     /* 13.31  Port Transmit state machine */
     FOREACH_PORT_IN_BRIDGE(prt, br)
         PTSM_begin(prt);
 
     /* 13.32  Port Information state machine */
     FOREACH_PORT_IN_BRIDGE(prt, br)
     {
         FOREACH_PTP_IN_PORT(ptp, prt)
         {
             ptp->start_time = br->uptime; /* 12.8.2.2.3 b) */
             PISM_begin(ptp);
         }
     }
 
     /* 13.33  Port Role Selection state machine */
     FOREACH_TREE_IN_BRIDGE(tree, br)
         PRSSM_begin(tree);
 
     /* 13.34  Port Role Transitions state machine */
     FOREACH_PORT_IN_BRIDGE(prt, br)
     {
         FOREACH_PTP_IN_PORT(ptp, prt)
             PRTSM_begin(ptp);
     }
     /* 13.35  Port State Transition state machine */
     FOREACH_PORT_IN_BRIDGE(prt, br)
     {
         FOREACH_PTP_IN_PORT(ptp, prt)
             PSTSM_begin(ptp);
     }
     /* 13.36  Topology Change state machine */
     FOREACH_PORT_IN_BRIDGE(prt, br)
     {
         FOREACH_PTP_IN_PORT(ptp, prt)
             TCSM_begin(ptp);
     }
 
     br_state_machines_run(br);
 }
 
 /* Run each state machine.
  * Return false iff all state machines in dry run indicate that
  * state will not be changed. Otherwise return true.
  */
 static bool __br_state_machines_run(bridge_t *br, bool dry_run)
 {
     port_t *prt;
     per_tree_port_t *ptp;
     tree_t *tree;
 
     /* Check if bridge assurance timer expires */
     FOREACH_PORT_IN_BRIDGE(prt, br)
     {
         if(prt->portEnabled && assurancePort(prt)
            && (0 == prt->brAssuRcvdInfoWhile) && !prt->BaInconsistent
           )
         {
             if(dry_run) /* state change */
                 return true;
             prt->BaInconsistent = true;
             ERROR_PRTNAME(prt->bridge, prt, "Bridge assurance inconsistent");
         }
     }
 
     /* 13.28  Port Receive state machine */
     FOREACH_PORT_IN_BRIDGE(prt, br)
     {
         if(PRSM_run(prt, dry_run) && dry_run)
             return true;
     }
     /* 13.29  Port Protocol Migration state machine */
     FOREACH_PORT_IN_BRIDGE(prt, br)
     {
         if(PPMSM_run(prt, dry_run) && dry_run)
             return true;
     }
     /* 13.30  Bridge Detection state machine */
     FOREACH_PORT_IN_BRIDGE(prt, br)
     {
         if(BDSM_run(prt, dry_run) && dry_run)
             return true;
     }
     /* 13.31  Port Transmit state machine */
     FOREACH_PORT_IN_BRIDGE(prt, br)
     {
         if(PTSM_run(prt, dry_run) && dry_run)
             return true;
     }
 
     /* 13.32  Port Information state machine */
     FOREACH_PORT_IN_BRIDGE(prt, br)
     {
         FOREACH_PTP_IN_PORT(ptp, prt)
         {
             if(PISM_run(ptp, dry_run) && dry_run)
                 return true;
         }
     }
 
     /* 13.33  Port Role Selection state machine */
     FOREACH_TREE_IN_BRIDGE(tree, br)
     {
         if(PRSSM_run(tree, dry_run) && dry_run)
             return true;
     }
 
     /* 13.34  Port Role Transitions state machine */
     FOREACH_PORT_IN_BRIDGE(prt, br)
     {
         FOREACH_PTP_IN_PORT(ptp, prt)
         {
             if(PRTSM_run(ptp, dry_run) && dry_run)
                 return true;
         }
     }
     /* 13.35  Port State Transition state machine */
     FOREACH_PORT_IN_BRIDGE(prt, br)
     {
         FOREACH_PTP_IN_PORT(ptp, prt)
         {
             if(PSTSM_run(ptp, dry_run) && dry_run)
                 return true;
         }
     }
     /* 13.36  Topology Change state machine */
     FOREACH_PORT_IN_BRIDGE(prt, br)
     {
         FOREACH_PTP_IN_PORT(ptp, prt)
         {
             if(TCSM_run(ptp, dry_run) && dry_run)
                 return true;
         }
     }
 
     return false;
 }
 
 /* Run state machines until their state stabilizes.
  * Do not consume more than 1 second.
  */
 static void br_state_machines_run(bridge_t *br)
 {
     struct timespec tv, tv_end;
     signed long delta;
 
     if(!br->bridgeEnabled)
         return;
 
     clock_gettime(CLOCK_MONOTONIC, &tv_end);
     ++(tv_end.tv_sec);
 
     do {
         if(!__br_state_machines_run(br, true /* dry run */))
             return;
         __br_state_machines_run(br, false /* actual run */);
 
         /* Check for the timeout */
         clock_gettime(CLOCK_MONOTONIC, &tv);
         if(0 < (delta = tv.tv_sec - tv_end.tv_sec))
             return;
         if(0 == delta)
         {
             delta = tv.tv_nsec - tv_end.tv_nsec;
             if(0 < delta)
                 return;
         }
     } while(true);
 }