/*
    * netifd - network interface daemon
    * Copyright (C) 2012 Felix Fietkau <nbd@openwrt.org>
    *
    * This program is free software; you can redistribute it and/or modify
    * it under the terms of the GNU General Public License version 2
    * as published by the Free Software Foundation
    *
    * This program is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   * GNU General Public License for more details.
   */
  #include <errno.h>
  #include <string.h>
  #include <stdlib.h>
  #include <stdio.h>
  #include <ctype.h>
  
  #include "netifd.h"
  #include "system.h"
  
  struct vlan_device {
          struct device dev;
          struct device_user dep;
  
          device_state_cb set_state;
          int id;
  };
  
  static void free_vlan_if(struct device *iface)
  {
          struct vlan_device *vldev;
  
          vldev = container_of(iface, struct vlan_device, dev);
          device_remove_user(&vldev->dep);
          device_cleanup(&vldev->dev);
          free(vldev);
  }
  
  static int
  __vlan_hotplug_op(struct device *dev, struct device *member, struct blob_attr *vlan, bool add)
  {
          struct vlan_device *vldev = container_of(dev, struct vlan_device, dev);
          /* local buffer: chained vlan devices re-enter this function with
           * the vlan attribute pointing into the caller's buffer */
          struct blob_buf b = {};
          void *a;
          int ret;
  
          dev = vldev->dep.dev;
          if (!dev || !dev->hotplug_ops)
                  return UBUS_STATUS_NOT_SUPPORTED;
  
          blob_buf_init(&b, 0);
          a = blobmsg_open_array(&b, "vlans");
          blobmsg_printf(&b, NULL, "%d:u", vldev->id);
          if (vlan && blobmsg_len(vlan))
                  blob_put_raw(&b, blobmsg_data(vlan), blobmsg_len(vlan));
          blobmsg_close_array(&b, a);
  
          if (add)
                  ret = dev->hotplug_ops->add(dev, member, blobmsg_data(b.head));
          else
                  ret = dev->hotplug_ops->del(dev, member, blobmsg_data(b.head));
  
          blob_buf_free(&b);
          return ret;
  }
  
  static int
  vlan_hotplug_add(struct device *dev, struct device *member, struct blob_attr *vlan)
  {
          return __vlan_hotplug_op(dev, member, vlan, true);
  }
  
  static int
  vlan_hotplug_del(struct device *dev, struct device *member, struct blob_attr *vlan)
  {
          return __vlan_hotplug_op(dev, member, vlan, false);
  }
  
  static int
  vlan_hotplug_prepare(struct device *dev, struct device **bridge_dev)
  {
          struct vlan_device *vldev = container_of(dev, struct vlan_device, dev);
  
          dev = vldev->dep.dev;
          if (!dev || !dev->hotplug_ops)
                  return UBUS_STATUS_NOT_SUPPORTED;
  
          return dev->hotplug_ops->prepare(dev, bridge_dev);
  }
  
  static void vlan_hotplug_check(struct vlan_device *vldev, struct device *dev)
  {
          static const struct device_hotplug_ops hotplug_ops = {
                  .prepare = vlan_hotplug_prepare,
                  .add = vlan_hotplug_add,
                 .del = vlan_hotplug_del
         };
 
         if (!dev || !dev->hotplug_ops || avl_is_empty(&dev->vlans.avl)) {
                 vldev->dev.hotplug_ops = NULL;
                 return;
         }
 
         vldev->dev.hotplug_ops = &hotplug_ops;
 }
 
 
 static int vlan_set_device_state(struct device *dev, bool up)
 {
         struct vlan_device *vldev;
         int ret = 0;
 
         vldev = container_of(dev, struct vlan_device, dev);
         if (!up) {
                 vldev->set_state(dev, false);
                 system_vlan_del(dev);
                 device_release(&vldev->dep);
                 return 0;
         }
 
         ret = device_claim(&vldev->dep);
         if (ret < 0)
                 return ret;
 
         /* tolerate a vlan device left behind by a previous netifd run */
         if (system_vlan_add(vldev->dep.dev, vldev->id) < 0 &&
             errno != EEXIST) {
                 ret = -1;
                 goto release;
         }
 
         ret = vldev->set_state(dev, true);
         if (ret)
                 goto delete;
 
         return 0;
 
 delete:
         system_vlan_del(dev);
 release:
         device_release(&vldev->dep);
         return ret;
 }
 
 static void vlan_dev_cb(struct device_user *dep, enum device_event ev)
 {
         char name[IFNAMSIZ];
         struct vlan_device *vldev;
 
         vldev = container_of(dep, struct vlan_device, dep);
         switch(ev) {
         case DEV_EVENT_ADD:
                 device_set_present(&vldev->dev, true);
                 break;
         case DEV_EVENT_REMOVE:
                 device_set_present(&vldev->dev, false);
                 break;
         case DEV_EVENT_UPDATE_IFNAME:
                 vlan_hotplug_check(vldev, dep->dev);
                 vldev->dev.hidden = dep->dev->hidden;
                 if (snprintf(name, sizeof(name), "%s.%d", dep->dev->ifname,
                              vldev->id) < (int)sizeof(name) &&
                     !device_set_ifname(&vldev->dev, name))
                         break;
 
                 /* freeing the device here would leave dangling device_user
                  * entries behind; detach it and let device_free_unused()
                  * reap it once the last user is gone */
                 device_set_present(&vldev->dev, false);
                 device_remove_user(&vldev->dep);
                 device_free_unused();
                 break;
         case DEV_EVENT_VLAN_UPDATE:
                 vlan_hotplug_check(vldev, dep->dev);
                 break;
         case DEV_EVENT_TOPO_CHANGE:
                 /* Propagate topo changes */
                 device_broadcast_event(&vldev->dev, DEV_EVENT_TOPO_CHANGE);
                 break;
         default:
                 break;
         }
 }
 
 static void
 vlan_config_init(struct device *dev)
 {
         struct vlan_device *vldev;
 
         vldev = container_of(dev, struct vlan_device, dev);
         vlan_hotplug_check(vldev, vldev->dep.dev);
 }
 
 static struct device *get_vlan_device(struct device *dev, char *id_str, bool create)
 {
         static struct device_type vlan_type = {
                 .name = "VLAN",
                 .config_params = &device_attr_list,
                 .config_init = vlan_config_init,
                 .free = free_vlan_if,
         };
         struct vlan_device *vldev;
         struct device_user *dep;
         char name[IFNAMSIZ];
         char *err = NULL;
         int id, *alias_id;
 
         id = strtoul(id_str, &err, 10);
         if (err && *err) {
                 alias_id = kvlist_get(&dev->vlan_aliases, id_str);
                 if (!alias_id)
                         return NULL;
 
                 id = *alias_id;
         }
 
         /* look for an existing interface before creating a new one */
         list_for_each_entry(dep, &dev->users.list, list.list) {
                 if (dep->cb != vlan_dev_cb)
                         continue;
 
                 vldev = container_of(dep, struct vlan_device, dep);
                 if (vldev->id != id)
                         continue;
 
                 return &vldev->dev;
         }
 
         if (!create)
                 return NULL;
 
         if (snprintf(name, sizeof(name), "%s.%d", dev->ifname, id) >= (int)sizeof(name))
                 return NULL;
 
         D(DEVICE, "Create vlan device '%s'", name);
 
         vldev = calloc(1, sizeof(*vldev));
         if (!vldev)
                 return NULL;
 
         vldev->id = id;
         vldev->dev.hidden = dev->hidden;
         strcpy(vldev->dev.ifname, name);
 
         if (device_init(&vldev->dev, &vlan_type, NULL) < 0)
                 goto error;
 
         vldev->dev.default_config = true;
         vldev->dev.config_pending = true;
 
         vldev->set_state = vldev->dev.set_state;
         vldev->dev.set_state = vlan_set_device_state;
 
         vldev->dep.cb = vlan_dev_cb;
         vlan_hotplug_check(vldev, vldev->dep.dev);
         device_add_user(&vldev->dep, dev);
 
         return &vldev->dev;
 
 error:
         device_cleanup(&vldev->dev);
         free(vldev);
         return NULL;
 }
 
 static char *split_vlan(char *s)
 {
         s = strchr(s, '.');
         if (!s)
                 return NULL;
 
         *s = 0;
         s++;
 
         return s;
 }
 
 struct device *get_vlan_device_chain(const char *ifname, int create)
 {
         struct device *dev = NULL, *vldev;
         char *buf, *s, *next;
 
         buf = strdup(ifname);
         if (!buf)
                 return NULL;
 
         s = split_vlan(buf);
         dev = __device_get(buf, create, false);
         if (!dev || !s)
                 goto out;
 
         /* for the first split, we need to check if we're using an alias or
          * if the . separator isn't being used as a vlan separator (e.g. for
          * AP WDS VLANs */
         if (!isdigit(s[0])) {
                 next = split_vlan(s);
                 vldev = get_vlan_device(dev, s, create);
                 if (!vldev) {
                         s[-1] = '.';
                         dev = __device_get(buf, create, false);
                         if (!dev)
                                 goto out;
 
                         if (next)
                                 next[-1] = '.';
                         s = next;
                 } else {
                         dev = vldev;
                         s = next;
                 }
         }
 
 
         while (s) {
                 next = split_vlan(s);
                 dev = get_vlan_device(dev, s, create);
                 if (!dev)
                         break;
 
                 s = next;
         }
 
 out:
         free(buf);
         return dev;
 }
 

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