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Sources/uhttpd/client.c

  1 /*
  2  * uhttpd - Tiny single-threaded httpd
  3  *
  4  *   Copyright (C) 2010-2013 Jo-Philipp Wich <xm@subsignal.org>
  5  *   Copyright (C) 2013 Felix Fietkau <nbd@openwrt.org>
  6  *
  7  * Permission to use, copy, modify, and/or distribute this software for any
  8  * purpose with or without fee is hereby granted, provided that the above
  9  * copyright notice and this permission notice appear in all copies.
 10  *
 11  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 12  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 13  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 14  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 15  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 16  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 17  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 18  */
 19 
 20 #include <libubox/blobmsg.h>
 21 #include <ctype.h>
 22 
 23 #include "uhttpd.h"
 24 #include "tls.h"
 25 
 26 static LIST_HEAD(clients);
 27 static bool client_done = false;
 28 
 29 int n_clients = 0;
 30 struct config conf = {};
 31 
 32 const char * const http_versions[] = {
 33         [UH_HTTP_VER_0_9] = "HTTP/0.9",
 34         [UH_HTTP_VER_1_0] = "HTTP/1.0",
 35         [UH_HTTP_VER_1_1] = "HTTP/1.1",
 36 };
 37 
 38 const char * const http_methods[] = {
 39         [UH_HTTP_MSG_GET] = "GET",
 40         [UH_HTTP_MSG_POST] = "POST",
 41         [UH_HTTP_MSG_HEAD] = "HEAD",
 42         [UH_HTTP_MSG_OPTIONS] = "OPTIONS",
 43         [UH_HTTP_MSG_PUT] = "PUT",
 44         [UH_HTTP_MSG_PATCH] = "PATCH",
 45         [UH_HTTP_MSG_DELETE] = "DELETE",
 46 };
 47 
 48 void uh_http_header(struct client *cl, int code, const char *summary)
 49 {
 50         struct http_request *r = &cl->request;
 51         struct blob_attr *cur;
 52         const char *enc = "Transfer-Encoding: chunked\r\n";
 53         const char *conn;
 54         int rem;
 55 
 56         cl->http_code = code;
 57 
 58         if (!uh_use_chunked(cl))
 59                 enc = "";
 60 
 61         if (r->connection_close)
 62                 conn = "Connection: close";
 63         else
 64                 conn = "Connection: Keep-Alive";
 65 
 66         ustream_printf(cl->us, "%s %03i %s\r\n%s\r\n%s",
 67                 http_versions[cl->request.version],
 68                 code, summary, conn, enc);
 69 
 70         if (!r->connection_close)
 71                 ustream_printf(cl->us, "Keep-Alive: timeout=%d\r\n", conf.http_keepalive);
 72 
 73         blobmsg_for_each_attr(cur, cl->hdr_response.head, rem)
 74                 ustream_printf(cl->us, "%s: %s\r\n", blobmsg_name(cur),
 75                                blobmsg_get_string(cur));
 76 }
 77 
 78 static void uh_connection_close(struct client *cl)
 79 {
 80         cl->state = CLIENT_STATE_CLOSE;
 81         cl->us->eof = true;
 82         ustream_state_change(cl->us);
 83 }
 84 
 85 static void uh_dispatch_done(struct client *cl)
 86 {
 87         if (cl->dispatch.free)
 88                 cl->dispatch.free(cl);
 89         if (cl->dispatch.req_free)
 90                 cl->dispatch.req_free(cl);
 91 }
 92 
 93 static void client_timeout(struct uloop_timeout *timeout)
 94 {
 95         struct client *cl = container_of(timeout, struct client, timeout);
 96 
 97         cl->state = CLIENT_STATE_CLOSE;
 98         cl->request.connection_close = true;
 99         uh_request_done(cl);
100 }
101 
102 static void uh_set_client_timeout(struct client *cl, int timeout)
103 {
104         cl->timeout.cb = client_timeout;
105         uloop_timeout_set(&cl->timeout, timeout * 1000);
106 }
107 
108 static void uh_keepalive_poll_cb(struct uloop_timeout *timeout)
109 {
110         struct client *cl = container_of(timeout, struct client, timeout);
111         int sec = cl->requests > 0 ? conf.http_keepalive : conf.network_timeout;
112 
113         uh_set_client_timeout(cl, sec);
114         cl->us->notify_read(cl->us, 0);
115 }
116 
117 static void uh_poll_connection(struct client *cl)
118 {
119         cl->timeout.cb = uh_keepalive_poll_cb;
120         uloop_timeout_set(&cl->timeout, 1);
121 }
122 
123 void uh_request_done(struct client *cl)
124 {
125         uh_chunk_eof(cl);
126         uh_dispatch_done(cl);
127         blob_buf_init(&cl->hdr_response, 0);
128         memset(&cl->dispatch, 0, sizeof(cl->dispatch));
129 
130         if (!conf.http_keepalive || cl->request.connection_close)
131                 return uh_connection_close(cl);
132 
133         cl->state = CLIENT_STATE_INIT;
134         cl->requests++;
135         uh_poll_connection(cl);
136 }
137 
138 void __printf(4, 5)
139 uh_client_error(struct client *cl, int code, const char *summary, const char *fmt, ...)
140 {
141         struct http_request *r = &cl->request;
142         va_list arg;
143 
144         uh_http_header(cl, code, summary);
145         ustream_printf(cl->us, "Content-Type: text/html\r\n\r\n");
146 
147         uh_chunk_printf(cl, "<h1>%s</h1>", summary);
148 
149         if (fmt) {
150                 va_start(arg, fmt);
151                 uh_chunk_vprintf(cl, fmt, arg);
152                 va_end(arg);
153         }
154 
155         /* Close the connection even when keep alive is set, when it
156          * contains a request body, as it was not read and we are
157          * currently out of sync. Without handling this the body will be
158          * interpreted as part of the next request. The alternative
159          * would be to read and discard the request body here.
160          */
161         if (r->transfer_chunked || r->content_length > 0) {
162                 cl->state = CLIENT_STATE_CLOSE;
163                 cl->request.connection_close = true;
164         }
165 
166         uh_request_done(cl);
167 }
168 
169 static void uh_header_error(struct client *cl, int code, const char *summary)
170 {
171         uh_client_error(cl, code, summary, NULL);
172         uh_connection_close(cl);
173 }
174 
175 static int find_idx(const char * const *list, int max, const char *str)
176 {
177         int i;
178 
179         for (i = 0; i < max; i++)
180                 if (!strcmp(list[i], str))
181                         return i;
182 
183         return -1;
184 }
185 
186 static int client_parse_request(struct client *cl, char *data)
187 {
188         struct http_request *req = &cl->request;
189         char *type, *path, *version;
190         int h_method, h_version;
191 
192         type = strtok(data, " ");
193         path = strtok(NULL, " ");
194         version = strtok(NULL, " ");
195         if (!type || !path || !version)
196                 return CLIENT_STATE_DONE;
197 
198         blobmsg_add_string(&cl->hdr, "URL", path);
199 
200         memset(&cl->request, 0, sizeof(cl->request));
201         h_method = find_idx(http_methods, ARRAY_SIZE(http_methods), type);
202         h_version = find_idx(http_versions, ARRAY_SIZE(http_versions), version);
203         if (h_method < 0 || h_version < 0) {
204                 req->version = UH_HTTP_VER_1_0;
205                 return CLIENT_STATE_DONE;
206         }
207 
208         req->method = h_method;
209         req->version = h_version;
210         if (req->version < UH_HTTP_VER_1_1 || !conf.http_keepalive)
211                 req->connection_close = true;
212 
213         return CLIENT_STATE_HEADER;
214 }
215 
216 static bool client_init_cb(struct client *cl, char *buf, int len)
217 {
218         char *newline;
219 
220         newline = strstr(buf, "\r\n");
221         if (!newline)
222                 return false;
223 
224         if (newline == buf) {
225                 ustream_consume(cl->us, 2);
226                 return true;
227         }
228 
229         *newline = 0;
230         blob_buf_init(&cl->hdr, 0);
231         cl->state = client_parse_request(cl, buf);
232         ustream_consume(cl->us, newline + 2 - buf);
233         if (cl->state == CLIENT_STATE_DONE)
234                 uh_header_error(cl, 400, "Bad Request");
235 
236         return true;
237 }
238 
239 static bool rfc1918_filter_check(struct client *cl)
240 {
241         if (!conf.rfc1918_filter)
242                 return true;
243 
244         if (!uh_addr_rfc1918(&cl->peer_addr) || uh_addr_rfc1918(&cl->srv_addr))
245                 return true;
246 
247         uh_client_error(cl, 403, "Forbidden",
248                         "Rejected request from RFC1918 IP "
249                         "to public server address");
250         return false;
251 }
252 
253 static bool tls_redirect_check(struct client *cl)
254 {
255         int rem, port;
256         struct blob_attr *cur;
257         char *ptr, *url = NULL, *host = NULL;
258 
259         if (cl->tls || !conf.tls_redirect)
260                 return true;
261 
262         if ((port = uh_first_tls_port(cl->srv_addr.family)) == -1)
263                 return true;
264 
265         blob_for_each_attr(cur, cl->hdr.head, rem) {
266                 if (!strncmp(blobmsg_name(cur), "host", 4))
267                         host = blobmsg_get_string(cur);
268 
269                 if (!strncmp(blobmsg_name(cur), "URL", 3))
270                         url = blobmsg_get_string(cur);
271 
272                 if (url && host)
273                         break;
274         }
275 
276         if (!url || !host)
277                 return true;
278 
279         if ((ptr = strchr(host, ']')) != NULL)
280                 *(ptr+1) = 0;
281         else if ((ptr = strchr(host, ':')) != NULL)
282                 *ptr = 0;
283 
284         cl->request.disable_chunked = true;
285         cl->request.connection_close = true;
286 
287         uh_http_header(cl, 307, "Temporary Redirect");
288 
289         if (port != 443)
290                 ustream_printf(cl->us, "Location: https://%s:%d%s\r\n\r\n", host, port, url);
291         else
292                 ustream_printf(cl->us, "Location: https://%s%s\r\n\r\n", host, url);
293 
294         uh_request_done(cl);
295 
296         return false;
297 }
298 
299 static void client_header_complete(struct client *cl)
300 {
301         struct http_request *r = &cl->request;
302 
303         if (!rfc1918_filter_check(cl))
304                 return;
305 
306         if (!tls_redirect_check(cl))
307                 return;
308 
309         if (r->expect_cont)
310                 ustream_printf(cl->us, "HTTP/1.1 100 Continue\r\n\r\n");
311 
312         switch(r->ua) {
313         case UH_UA_MSIE_OLD:
314                 if (r->method != UH_HTTP_MSG_POST)
315                         break;
316 
317                 /* fall through */
318         case UH_UA_SAFARI:
319                 r->connection_close = true;
320                 break;
321         default:
322                 break;
323         }
324 
325         uh_handle_request(cl);
326 }
327 
328 static void client_parse_header(struct client *cl, char *data)
329 {
330         struct http_request *r = &cl->request;
331         char *err;
332         char *name;
333         char *val;
334 
335         if (!*data) {
336                 uloop_timeout_cancel(&cl->timeout);
337                 cl->state = CLIENT_STATE_DATA;
338                 client_header_complete(cl);
339                 return;
340         }
341 
342         val = uh_split_header(data);
343         if (!val) {
344                 cl->state = CLIENT_STATE_DONE;
345                 return;
346         }
347 
348         for (name = data; *name; name++)
349                 if (isupper(*name))
350                         *name = tolower(*name);
351 
352         if (!strcmp(data, "expect")) {
353                 if (!strcasecmp(val, "100-continue"))
354                         r->expect_cont = true;
355                 else {
356                         uh_header_error(cl, 412, "Precondition Failed");
357                         return;
358                 }
359         } else if (!strcmp(data, "content-length")) {
360                 r->content_length = strtoul(val, &err, 0);
361                 if ((err && *err) || r->content_length < 0) {
362                         uh_header_error(cl, 400, "Bad Request");
363                         return;
364                 }
365         } else if (!strcmp(data, "transfer-encoding")) {
366                 if (!strcmp(val, "chunked"))
367                         r->transfer_chunked = true;
368         } else if (!strcmp(data, "connection")) {
369                 if (!strcasecmp(val, "close"))
370                         r->connection_close = true;
371         } else if (!strcmp(data, "user-agent")) {
372                 char *str;
373 
374                 if (strstr(val, "Opera"))
375                         r->ua = UH_UA_OPERA;
376                 else if ((str = strstr(val, "MSIE ")) != NULL) {
377                         r->ua = UH_UA_MSIE_NEW;
378                         if (str[5] && str[6] == '.') {
379                                 switch (str[5]) {
380                                 case '6':
381                                         if (strstr(str, "SV1"))
382                                                 break;
383                                         /* fall through */
384                                 case '5':
385                                 case '4':
386                                         r->ua = UH_UA_MSIE_OLD;
387                                         break;
388                                 }
389                         }
390                 }
391                 else if (strstr(val, "Chrome/"))
392                         r->ua = UH_UA_CHROME;
393                 else if (strstr(val, "Safari/") && strstr(val, "Mac OS X"))
394                         r->ua = UH_UA_SAFARI;
395                 else if (strstr(val, "Gecko/"))
396                         r->ua = UH_UA_GECKO;
397                 else if (strstr(val, "Konqueror"))
398                         r->ua = UH_UA_KONQUEROR;
399         }
400 
401 
402         blobmsg_add_string(&cl->hdr, data, val);
403 
404         cl->state = CLIENT_STATE_HEADER;
405 }
406 
407 void client_poll_post_data(struct client *cl)
408 {
409         struct dispatch *d = &cl->dispatch;
410         struct http_request *r = &cl->request;
411         enum client_state st;
412         char *buf;
413         int len;
414 
415         if (cl->state == CLIENT_STATE_DONE)
416                 return;
417 
418         while (1) {
419                 char *sep;
420                 int offset = 0;
421                 int cur_len;
422 
423                 buf = ustream_get_read_buf(cl->us, &len);
424                 if (!buf || !len)
425                         break;
426 
427                 if (!d->data_send)
428                         return;
429 
430                 cur_len = min(r->content_length, len);
431                 if (cur_len) {
432                         if (d->data_blocked)
433                                 break;
434 
435                         if (d->data_send)
436                                 cur_len = d->data_send(cl, buf, cur_len);
437 
438                         r->content_length -= cur_len;
439                         ustream_consume(cl->us, cur_len);
440                         continue;
441                 }
442 
443                 if (!r->transfer_chunked)
444                         break;
445 
446                 if (r->transfer_chunked > 1)
447                         offset = 2;
448 
449                 sep = strstr(buf + offset, "\r\n");
450                 if (!sep)
451                         break;
452 
453                 *sep = 0;
454 
455                 r->content_length = strtoul(buf + offset, &sep, 16);
456                 r->transfer_chunked++;
457                 ustream_consume(cl->us, sep + 2 - buf);
458 
459                 /* invalid chunk length */
460                 if ((sep && *sep) || r->content_length < 0) {
461                         r->content_length = 0;
462                         r->transfer_chunked = 0;
463                         break;
464                 }
465 
466                 /* empty chunk == eof */
467                 if (!r->content_length) {
468                         r->transfer_chunked = false;
469                         break;
470                 }
471         }
472 
473         buf = ustream_get_read_buf(cl->us, &len);
474         if (!r->content_length && !r->transfer_chunked &&
475                 cl->state != CLIENT_STATE_DONE) {
476                 st = cl->state;
477 
478                 if (cl->dispatch.data_done)
479                         cl->dispatch.data_done(cl);
480 
481                 if (cl->state == st)
482                         cl->state = CLIENT_STATE_DONE;
483         }
484 }
485 
486 static bool client_data_cb(struct client *cl, char *buf, int len)
487 {
488         client_poll_post_data(cl);
489         return false;
490 }
491 
492 static bool client_header_cb(struct client *cl, char *buf, int len)
493 {
494         char *newline;
495         int line_len;
496 
497         newline = strstr(buf, "\r\n");
498         if (!newline)
499                 return false;
500 
501         *newline = 0;
502         client_parse_header(cl, buf);
503         line_len = newline + 2 - buf;
504         ustream_consume(cl->us, line_len);
505         if (cl->state == CLIENT_STATE_DATA)
506                 return client_data_cb(cl, newline + 2, len - line_len);
507 
508         return true;
509 }
510 
511 typedef bool (*read_cb_t)(struct client *cl, char *buf, int len);
512 static read_cb_t read_cbs[] = {
513         [CLIENT_STATE_INIT] = client_init_cb,
514         [CLIENT_STATE_HEADER] = client_header_cb,
515         [CLIENT_STATE_DATA] = client_data_cb,
516 };
517 
518 void uh_client_read_cb(struct client *cl)
519 {
520         struct ustream *us = cl->us;
521         char *str;
522         int len;
523 
524         client_done = false;
525         do {
526                 str = ustream_get_read_buf(us, &len);
527                 if (!str || !len)
528                         break;
529 
530                 if (cl->state >= array_size(read_cbs) || !read_cbs[cl->state])
531                         break;
532 
533                 if (!read_cbs[cl->state](cl, str, len)) {
534                         if (len == us->r.buffer_len &&
535                             cl->state != CLIENT_STATE_DATA &&
536                             cl->state != CLIENT_STATE_DONE)
537                                 uh_header_error(cl, 413, "Request Entity Too Large");
538                         break;
539                 }
540         } while (!client_done);
541 }
542 
543 static void client_close(struct client *cl)
544 {
545         if (cl->refcount) {
546                 cl->state = CLIENT_STATE_CLEANUP;
547                 return;
548         }
549 
550         client_done = true;
551         n_clients--;
552         uh_dispatch_done(cl);
553         uloop_timeout_cancel(&cl->timeout);
554         if (cl->tls)
555                 uh_tls_client_detach(cl);
556         ustream_free(&cl->sfd.stream);
557         close(cl->sfd.fd.fd);
558         list_del(&cl->list);
559         blob_buf_free(&cl->hdr);
560         blob_buf_free(&cl->hdr_response);
561         free(cl);
562 
563         uh_unblock_listeners();
564 }
565 
566 void uh_client_notify_state(struct client *cl)
567 {
568         struct ustream *s = cl->us;
569 
570         if (!s->write_error && cl->state != CLIENT_STATE_CLEANUP) {
571                 if (cl->state == CLIENT_STATE_DATA)
572                         return;
573 
574                 if (!s->eof || s->w.data_bytes)
575                         return;
576 
577 #ifdef HAVE_TLS
578                 if (cl->tls && cl->ssl.conn && cl->ssl.conn->w.data_bytes) {
579                         cl->ssl.conn->eof = s->eof;
580                         if (!ustream_write_pending(cl->ssl.conn))
581                                 return;
582                 }
583 #endif
584         }
585 
586         return client_close(cl);
587 }
588 
589 static void client_ustream_read_cb(struct ustream *s, int bytes)
590 {
591         struct client *cl = container_of(s, struct client, sfd.stream);
592 
593         uh_client_read_cb(cl);
594 }
595 
596 static void client_ustream_write_cb(struct ustream *s, int bytes)
597 {
598         struct client *cl = container_of(s, struct client, sfd.stream);
599 
600         if (cl->dispatch.write_cb)
601                 cl->dispatch.write_cb(cl);
602 }
603 
604 static void client_notify_state(struct ustream *s)
605 {
606         struct client *cl = container_of(s, struct client, sfd.stream);
607 
608         uh_client_notify_state(cl);
609 }
610 
611 static void set_addr(struct uh_addr *addr, void *src)
612 {
613         struct sockaddr_in *sin = src;
614         struct sockaddr_in6 *sin6 = src;
615 
616         addr->family = sin->sin_family;
617         if (addr->family == AF_INET) {
618                 addr->port = ntohs(sin->sin_port);
619                 memcpy(&addr->in, &sin->sin_addr, sizeof(addr->in));
620         } else {
621                 addr->port = ntohs(sin6->sin6_port);
622                 memcpy(&addr->in6, &sin6->sin6_addr, sizeof(addr->in6));
623         }
624 }
625 
626 bool uh_accept_client(int fd, bool tls)
627 {
628         static struct client *next_client;
629         struct client *cl;
630         unsigned int sl;
631         int sfd;
632         static int client_id = 0;
633         struct sockaddr_in6 addr;
634 
635         if (!next_client)
636                 next_client = calloc(1, sizeof(*next_client));
637 
638         cl = next_client;
639 
640         sl = sizeof(addr);
641         sfd = accept(fd, (struct sockaddr *) &addr, &sl);
642         if (sfd < 0)
643                 return false;
644 
645         set_addr(&cl->peer_addr, &addr);
646         sl = sizeof(addr);
647         getsockname(sfd, (struct sockaddr *) &addr, &sl);
648         set_addr(&cl->srv_addr, &addr);
649 
650         cl->us = &cl->sfd.stream;
651         if (tls) {
652                 uh_tls_client_attach(cl);
653         } else {
654                 cl->us->notify_read = client_ustream_read_cb;
655                 cl->us->notify_write = client_ustream_write_cb;
656                 cl->us->notify_state = client_notify_state;
657         }
658 
659         cl->us->string_data = true;
660         ustream_fd_init(&cl->sfd, sfd);
661 
662         uh_poll_connection(cl);
663         list_add_tail(&cl->list, &clients);
664 
665         next_client = NULL;
666         n_clients++;
667         cl->id = client_id++;
668         cl->tls = tls;
669 
670         return true;
671 }
672 
673 void uh_close_fds(void)
674 {
675         struct client *cl;
676 
677         uloop_done();
678         uh_close_listen_fds();
679         list_for_each_entry(cl, &clients, list) {
680                 close(cl->sfd.fd.fd);
681                 if (cl->dispatch.close_fds)
682                         cl->dispatch.close_fds(cl);
683         }
684 }
685 

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