AST-2013-002: Prevent denial of service in HTTP server
[asterisk/asterisk.git] / main / http.c
1 /*
2  * Asterisk -- An open source telephony toolkit.
3  *
4  * Copyright (C) 1999 - 2006, Digium, Inc.
5  *
6  * Mark Spencer <markster@digium.com>
7  *
8  * See http://www.asterisk.org for more information about
9  * the Asterisk project. Please do not directly contact
10  * any of the maintainers of this project for assistance;
11  * the project provides a web site, mailing lists and IRC
12  * channels for your use.
13  *
14  * This program is free software, distributed under the terms of
15  * the GNU General Public License Version 2. See the LICENSE file
16  * at the top of the source tree.
17  */
18
19 /*!
20  * \file
21  * \brief http server for AMI access
22  *
23  * \author Mark Spencer <markster@digium.com>
24  *
25  * This program implements a tiny http server
26  * and was inspired by micro-httpd by Jef Poskanzer
27  *
28  * GMime http://spruce.sourceforge.net/gmime/
29  *
30  * \ref AstHTTP - AMI over the http protocol
31  */
32
33 /*! \li \ref http.c uses the configuration file \ref http.conf
34  * \addtogroup configuration_file
35  */
36
37 /*! \page http.conf http.conf
38  * \verbinclude http.conf.sample
39  */
40
41 /*** MODULEINFO
42         <support_level>core</support_level>
43  ***/
44
45 #include "asterisk.h"
46
47 ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
48
49 #include <time.h>
50 #include <sys/time.h>
51 #include <sys/stat.h>
52 #include <sys/signal.h>
53 #include <fcntl.h>
54
55 #include "asterisk/paths.h"     /* use ast_config_AST_DATA_DIR */
56 #include "asterisk/cli.h"
57 #include "asterisk/tcptls.h"
58 #include "asterisk/http.h"
59 #include "asterisk/utils.h"
60 #include "asterisk/strings.h"
61 #include "asterisk/config.h"
62 #include "asterisk/stringfields.h"
63 #include "asterisk/ast_version.h"
64 #include "asterisk/manager.h"
65 #include "asterisk/_private.h"
66 #include "asterisk/astobj2.h"
67 #include "asterisk/netsock2.h"
68
69 #define MAX_PREFIX 80
70 #define DEFAULT_PORT 8088
71 #define DEFAULT_TLS_PORT 8089
72 #define DEFAULT_SESSION_LIMIT 100
73
74 /* See http.h for more information about the SSL implementation */
75 #if defined(HAVE_OPENSSL) && (defined(HAVE_FUNOPEN) || defined(HAVE_FOPENCOOKIE))
76 #define DO_SSL  /* comment in/out if you want to support ssl */
77 #endif
78
79 static int session_limit = DEFAULT_SESSION_LIMIT;
80 static int session_count = 0;
81
82 static struct ast_tls_config http_tls_cfg;
83
84 static void *httpd_helper_thread(void *arg);
85
86 /*!
87  * we have up to two accepting threads, one for http, one for https
88  */
89 static struct ast_tcptls_session_args http_desc = {
90         .accept_fd = -1,
91         .master = AST_PTHREADT_NULL,
92         .tls_cfg = NULL,
93         .poll_timeout = -1,
94         .name = "http server",
95         .accept_fn = ast_tcptls_server_root,
96         .worker_fn = httpd_helper_thread,
97 };
98
99 static struct ast_tcptls_session_args https_desc = {
100         .accept_fd = -1,
101         .master = AST_PTHREADT_NULL,
102         .tls_cfg = &http_tls_cfg,
103         .poll_timeout = -1,
104         .name = "https server",
105         .accept_fn = ast_tcptls_server_root,
106         .worker_fn = httpd_helper_thread,
107 };
108
109 static AST_RWLIST_HEAD_STATIC(uris, ast_http_uri);      /*!< list of supported handlers */
110
111 /* all valid URIs must be prepended by the string in prefix. */
112 static char prefix[MAX_PREFIX];
113 static int enablestatic;
114
115 /*! \brief Limit the kinds of files we're willing to serve up */
116 static struct {
117         const char *ext;
118         const char *mtype;
119 } mimetypes[] = {
120         { "png", "image/png" },
121         { "xml", "text/xml" },
122         { "jpg", "image/jpeg" },
123         { "js", "application/x-javascript" },
124         { "wav", "audio/x-wav" },
125         { "mp3", "audio/mpeg" },
126         { "svg", "image/svg+xml" },
127         { "svgz", "image/svg+xml" },
128         { "gif", "image/gif" },
129         { "html", "text/html" },
130         { "htm", "text/html" },
131         { "css", "text/css" },
132         { "cnf", "text/plain" },
133         { "cfg", "text/plain" },
134         { "bin", "application/octet-stream" },
135         { "sbn", "application/octet-stream" },
136         { "ld", "application/octet-stream" },
137 };
138
139 struct http_uri_redirect {
140         AST_LIST_ENTRY(http_uri_redirect) entry;
141         char *dest;
142         char target[0];
143 };
144
145 static AST_RWLIST_HEAD_STATIC(uri_redirects, http_uri_redirect);
146
147 static const struct ast_cfhttp_methods_text {
148         enum ast_http_method method;
149         const char *text;
150 } ast_http_methods_text[] = {
151         { AST_HTTP_UNKNOWN,     "UNKNOWN" },
152         { AST_HTTP_GET,         "GET" },
153         { AST_HTTP_POST,        "POST" },
154         { AST_HTTP_HEAD,        "HEAD" },
155         { AST_HTTP_PUT,         "PUT" },
156 };
157
158 const char *ast_get_http_method(enum ast_http_method method)
159 {
160         int x;
161
162         for (x = 0; x < ARRAY_LEN(ast_http_methods_text); x++) {
163                 if (ast_http_methods_text[x].method == method) {
164                         return ast_http_methods_text[x].text;
165                 }
166         }
167
168         return NULL;
169 }
170
171 const char *ast_http_ftype2mtype(const char *ftype)
172 {
173         int x;
174
175         if (ftype) {
176                 for (x = 0; x < ARRAY_LEN(mimetypes); x++) {
177                         if (!strcasecmp(ftype, mimetypes[x].ext)) {
178                                 return mimetypes[x].mtype;
179                         }
180                 }
181         }
182         return NULL;
183 }
184
185 uint32_t ast_http_manid_from_vars(struct ast_variable *headers)
186 {
187         uint32_t mngid = 0;
188         struct ast_variable *v, *cookies;
189
190         cookies = ast_http_get_cookies(headers);
191         for (v = cookies; v; v = v->next) {
192                 if (!strcasecmp(v->name, "mansession_id")) {
193                         sscanf(v->value, "%30x", &mngid);
194                         break;
195                 }
196         }
197         if (cookies) {
198                 ast_variables_destroy(cookies);
199         }
200         return mngid;
201 }
202
203 void ast_http_prefix(char *buf, int len)
204 {
205         if (buf) {
206                 ast_copy_string(buf, prefix, len);
207         }
208 }
209
210 static int static_callback(struct ast_tcptls_session_instance *ser,
211         const struct ast_http_uri *urih, const char *uri,
212         enum ast_http_method method, struct ast_variable *get_vars,
213         struct ast_variable *headers)
214 {
215         char *path;
216         const char *ftype;
217         const char *mtype;
218         char wkspace[80];
219         struct stat st;
220         int len;
221         int fd;
222         struct ast_str *http_header;
223         struct timeval tv;
224         struct ast_tm tm;
225         char timebuf[80], etag[23];
226         struct ast_variable *v;
227         int not_modified = 0;
228
229         if (method != AST_HTTP_GET && method != AST_HTTP_HEAD) {
230                 ast_http_error(ser, 501, "Not Implemented", "Attempt to use unimplemented / unsupported method");
231                 return -1;
232         }
233
234         /* Yuck.  I'm not really sold on this, but if you don't deliver static content it makes your configuration
235            substantially more challenging, but this seems like a rather irritating feature creep on Asterisk. */
236         if (!enablestatic || ast_strlen_zero(uri)) {
237                 goto out403;
238         }
239
240         /* Disallow any funny filenames at all */
241         if ((uri[0] < 33) || strchr("./|~@#$%^&*() \t", uri[0])) {
242                 goto out403;
243         }
244
245         if (strstr(uri, "/..")) {
246                 goto out403;
247         }
248
249         if ((ftype = strrchr(uri, '.'))) {
250                 ftype++;
251         }
252
253         if (!(mtype = ast_http_ftype2mtype(ftype))) {
254                 snprintf(wkspace, sizeof(wkspace), "text/%s", S_OR(ftype, "plain"));
255         }
256
257         /* Cap maximum length */
258         if ((len = strlen(uri) + strlen(ast_config_AST_DATA_DIR) + strlen("/static-http/") + 5) > 1024) {
259                 goto out403;
260         }
261
262         path = ast_alloca(len);
263         sprintf(path, "%s/static-http/%s", ast_config_AST_DATA_DIR, uri);
264         if (stat(path, &st)) {
265                 goto out404;
266         }
267
268         if (S_ISDIR(st.st_mode)) {
269                 goto out404;
270         }
271
272         fd = open(path, O_RDONLY);
273         if (fd < 0) {
274                 goto out403;
275         }
276
277         if (strstr(path, "/private/") && !astman_is_authed(ast_http_manid_from_vars(headers))) {
278                 goto out403;
279         }
280
281         /* make "Etag:" http header value */
282         snprintf(etag, sizeof(etag), "\"%ld\"", (long)st.st_mtime);
283
284         /* make "Last-Modified:" http header value */
285         tv.tv_sec = st.st_mtime;
286         tv.tv_usec = 0;
287         ast_strftime(timebuf, sizeof(timebuf), "%a, %d %b %Y %H:%M:%S GMT", ast_localtime(&tv, &tm, "GMT"));
288
289         /* check received "If-None-Match" request header and Etag value for file */
290         for (v = headers; v; v = v->next) {
291                 if (!strcasecmp(v->name, "If-None-Match")) {
292                         if (!strcasecmp(v->value, etag)) {
293                                 not_modified = 1;
294                         }
295                         break;
296                 }
297         }
298
299         if ( (http_header = ast_str_create(255)) == NULL) {
300                 return -1;
301         }
302
303         ast_str_set(&http_header, 0, "Content-type: %s\r\n"
304                 "ETag: %s\r\n"
305                 "Last-Modified: %s\r\n",
306                 mtype,
307                 etag,
308                 timebuf);
309
310         /* ast_http_send() frees http_header, so we don't need to do it before returning */
311         if (not_modified) {
312                 ast_http_send(ser, method, 304, "Not Modified", http_header, NULL, 0, 1);
313         } else {
314                 ast_http_send(ser, method, 200, NULL, http_header, NULL, fd, 1); /* static content flag is set */
315         }
316         close(fd);
317         return 0;
318
319 out404:
320         ast_http_error(ser, 404, "Not Found", "The requested URL was not found on this server.");
321         return -1;
322
323 out403:
324         ast_http_error(ser, 403, "Access Denied", "You do not have permission to access the requested URL.");
325         return -1;
326 }
327
328 static int httpstatus_callback(struct ast_tcptls_session_instance *ser,
329         const struct ast_http_uri *urih, const char *uri,
330         enum ast_http_method method, struct ast_variable *get_vars,
331         struct ast_variable *headers)
332 {
333         struct ast_str *out;
334         struct ast_variable *v, *cookies = NULL;
335
336         if (method != AST_HTTP_GET && method != AST_HTTP_HEAD) {
337                 ast_http_error(ser, 501, "Not Implemented", "Attempt to use unimplemented / unsupported method");
338                 return -1;
339         }
340
341         if ( (out = ast_str_create(512)) == NULL) {
342                 return -1;
343         }
344
345         ast_str_append(&out, 0,
346                 "<title>Asterisk HTTP Status</title>\r\n"
347                 "<body bgcolor=\"#ffffff\">\r\n"
348                 "<table bgcolor=\"#f1f1f1\" align=\"center\"><tr><td bgcolor=\"#e0e0ff\" colspan=\"2\" width=\"500\">\r\n"
349                 "<h2>&nbsp;&nbsp;Asterisk&trade; HTTP Status</h2></td></tr>\r\n");
350
351         ast_str_append(&out, 0, "<tr><td><i>Prefix</i></td><td><b>%s</b></td></tr>\r\n", prefix);
352         ast_str_append(&out, 0, "<tr><td><i>Bind Address</i></td><td><b>%s</b></td></tr>\r\n",
353                        ast_sockaddr_stringify_addr(&http_desc.old_address));
354         ast_str_append(&out, 0, "<tr><td><i>Bind Port</i></td><td><b>%s</b></td></tr>\r\n",
355                        ast_sockaddr_stringify_port(&http_desc.old_address));
356         if (http_tls_cfg.enabled) {
357                 ast_str_append(&out, 0, "<tr><td><i>SSL Bind Port</i></td><td><b>%s</b></td></tr>\r\n",
358                                ast_sockaddr_stringify_port(&https_desc.old_address));
359         }
360         ast_str_append(&out, 0, "<tr><td colspan=\"2\"><hr></td></tr>\r\n");
361         for (v = get_vars; v; v = v->next) {
362                 ast_str_append(&out, 0, "<tr><td><i>Submitted GET Variable '%s'</i></td><td>%s</td></tr>\r\n", v->name, v->value);
363         }
364         ast_str_append(&out, 0, "<tr><td colspan=\"2\"><hr></td></tr>\r\n");
365
366         cookies = ast_http_get_cookies(headers);
367         for (v = cookies; v; v = v->next) {
368                 ast_str_append(&out, 0, "<tr><td><i>Cookie '%s'</i></td><td>%s</td></tr>\r\n", v->name, v->value);
369         }
370         ast_variables_destroy(cookies);
371
372         ast_str_append(&out, 0, "</table><center><font size=\"-1\"><i>Asterisk and Digium are registered trademarks of Digium, Inc.</i></font></center></body>\r\n");
373         ast_http_send(ser, method, 200, NULL, NULL, out, 0, 0);
374         return 0;
375 }
376
377 static struct ast_http_uri statusuri = {
378         .callback = httpstatus_callback,
379         .description = "Asterisk HTTP General Status",
380         .uri = "httpstatus",
381         .has_subtree = 0,
382         .data = NULL,
383         .key = __FILE__,
384 };
385
386 static struct ast_http_uri staticuri = {
387         .callback = static_callback,
388         .description = "Asterisk HTTP Static Delivery",
389         .uri = "static",
390         .has_subtree = 1,
391         .data = NULL,
392         .key= __FILE__,
393 };
394
395
396 /* send http/1.1 response */
397 /* free content variable and close socket*/
398 void ast_http_send(struct ast_tcptls_session_instance *ser,
399         enum ast_http_method method, int status_code, const char *status_title,
400         struct ast_str *http_header, struct ast_str *out, const int fd,
401         unsigned int static_content)
402 {
403         struct timeval now = ast_tvnow();
404         struct ast_tm tm;
405         char timebuf[80];
406         int content_length = 0;
407
408         if (!ser || 0 == ser->f) {
409                 return;
410         }
411
412         ast_strftime(timebuf, sizeof(timebuf), "%a, %d %b %Y %H:%M:%S GMT", ast_localtime(&now, &tm, "GMT"));
413
414         /* calc content length */
415         if (out) {
416                 content_length += strlen(ast_str_buffer(out));
417         }
418
419         if (fd) {
420                 content_length += lseek(fd, 0, SEEK_END);
421                 lseek(fd, 0, SEEK_SET);
422         }
423
424         /* send http header */
425         fprintf(ser->f, "HTTP/1.1 %d %s\r\n"
426                 "Server: Asterisk/%s\r\n"
427                 "Date: %s\r\n"
428                 "Connection: close\r\n"
429                 "%s"
430                 "Content-Length: %d\r\n"
431                 "%s"
432                 "\r\n",
433                 status_code, status_title ? status_title : "OK",
434                 ast_get_version(),
435                 timebuf,
436                 static_content ? "" : "Cache-Control: no-cache, no-store\r\n",
437                 content_length,
438                 http_header ? ast_str_buffer(http_header) : ""
439                 );
440
441         /* send content */
442         if (method != AST_HTTP_HEAD || status_code >= 400) {
443                 if (out) {
444                         fprintf(ser->f, "%s", ast_str_buffer(out));
445                 }
446
447                 if (fd) {
448                         char buf[256];
449                         int len;
450                         while ((len = read(fd, buf, sizeof(buf))) > 0) {
451                                 if (fwrite(buf, len, 1, ser->f) != 1) {
452                                         ast_log(LOG_WARNING, "fwrite() failed: %s\n", strerror(errno));
453                                         break;
454                                 }
455                         }
456                 }
457         }
458
459         if (http_header) {
460                 ast_free(http_header);
461         }
462         if (out) {
463                 ast_free(out);
464         }
465
466         fclose(ser->f);
467         ser->f = 0;
468         return;
469 }
470
471 /* Send http "401 Unauthorized" responce and close socket*/
472 void ast_http_auth(struct ast_tcptls_session_instance *ser, const char *realm,
473         const unsigned long nonce, const unsigned long opaque, int stale,
474         const char *text)
475 {
476         struct ast_str *http_headers = ast_str_create(128);
477         struct ast_str *out = ast_str_create(512);
478
479         if (!http_headers || !out) {
480                 ast_free(http_headers);
481                 ast_free(out);
482                 return;
483         }
484
485         ast_str_set(&http_headers, 0,
486                 "WWW-authenticate: Digest algorithm=MD5, realm=\"%s\", nonce=\"%08lx\", qop=\"auth\", opaque=\"%08lx\"%s\r\n"
487                 "Content-type: text/html\r\n",
488                 realm ? realm : "Asterisk",
489                 nonce,
490                 opaque,
491                 stale ? ", stale=true" : "");
492
493         ast_str_set(&out, 0,
494                 "<!DOCTYPE HTML PUBLIC \"-//IETF//DTD HTML 2.0//EN\">\r\n"
495                 "<html><head>\r\n"
496                 "<title>401 Unauthorized</title>\r\n"
497                 "</head><body>\r\n"
498                 "<h1>401 Unauthorized</h1>\r\n"
499                 "<p>%s</p>\r\n"
500                 "<hr />\r\n"
501                 "<address>Asterisk Server</address>\r\n"
502                 "</body></html>\r\n",
503                 text ? text : "");
504
505         ast_http_send(ser, AST_HTTP_UNKNOWN, 401, "Unauthorized", http_headers, out, 0, 0);
506         return;
507 }
508
509 /* send http error response and close socket*/
510 void ast_http_error(struct ast_tcptls_session_instance *ser, int status_code, const char *status_title, const char *text)
511 {
512         struct ast_str *http_headers = ast_str_create(40);
513         struct ast_str *out = ast_str_create(256);
514
515         if (!http_headers || !out) {
516                 ast_free(http_headers);
517                 ast_free(out);
518                 return;
519         }
520
521         ast_str_set(&http_headers, 0, "Content-type: text/html\r\n");
522
523         ast_str_set(&out, 0,
524                 "<!DOCTYPE HTML PUBLIC \"-//IETF//DTD HTML 2.0//EN\">\r\n"
525                 "<html><head>\r\n"
526                 "<title>%d %s</title>\r\n"
527                 "</head><body>\r\n"
528                 "<h1>%s</h1>\r\n"
529                 "<p>%s</p>\r\n"
530                 "<hr />\r\n"
531                 "<address>Asterisk Server</address>\r\n"
532                 "</body></html>\r\n",
533                         status_code, status_title, status_title, text);
534
535         ast_http_send(ser, AST_HTTP_UNKNOWN, status_code, status_title, http_headers, out, 0, 0);
536         return;
537 }
538
539 /*! \brief
540  * Link the new uri into the list.
541  *
542  * They are sorted by length of
543  * the string, not alphabetically. Duplicate entries are not replaced,
544  * but the insertion order (using <= and not just <) makes sure that
545  * more recent insertions hide older ones.
546  * On a lookup, we just scan the list and stop at the first matching entry.
547  */
548 int ast_http_uri_link(struct ast_http_uri *urih)
549 {
550         struct ast_http_uri *uri;
551         int len = strlen(urih->uri);
552
553         AST_RWLIST_WRLOCK(&uris);
554
555         if ( AST_RWLIST_EMPTY(&uris) || strlen(AST_RWLIST_FIRST(&uris)->uri) <= len ) {
556                 AST_RWLIST_INSERT_HEAD(&uris, urih, entry);
557                 AST_RWLIST_UNLOCK(&uris);
558                 return 0;
559         }
560
561         AST_RWLIST_TRAVERSE(&uris, uri, entry) {
562                 if (AST_RWLIST_NEXT(uri, entry) &&
563                         strlen(AST_RWLIST_NEXT(uri, entry)->uri) <= len) {
564                         AST_RWLIST_INSERT_AFTER(&uris, uri, urih, entry);
565                         AST_RWLIST_UNLOCK(&uris);
566
567                         return 0;
568                 }
569         }
570
571         AST_RWLIST_INSERT_TAIL(&uris, urih, entry);
572
573         AST_RWLIST_UNLOCK(&uris);
574
575         return 0;
576 }
577
578 void ast_http_uri_unlink(struct ast_http_uri *urih)
579 {
580         AST_RWLIST_WRLOCK(&uris);
581         AST_RWLIST_REMOVE(&uris, urih, entry);
582         AST_RWLIST_UNLOCK(&uris);
583 }
584
585 void ast_http_uri_unlink_all_with_key(const char *key)
586 {
587         struct ast_http_uri *urih;
588         AST_RWLIST_WRLOCK(&uris);
589         AST_RWLIST_TRAVERSE_SAFE_BEGIN(&uris, urih, entry) {
590                 if (!strcmp(urih->key, key)) {
591                         AST_RWLIST_REMOVE_CURRENT(entry);
592                         if (urih->dmallocd) {
593                                 ast_free(urih->data);
594                         }
595                         if (urih->mallocd) {
596                                 ast_free(urih);
597                         }
598                 }
599         }
600         AST_RWLIST_TRAVERSE_SAFE_END;
601         AST_RWLIST_UNLOCK(&uris);
602 }
603
604 #define MAX_POST_CONTENT 1025
605
606 /*
607  * get post variables from client Request Entity-Body, if content type is
608  * application/x-www-form-urlencoded
609  */
610 struct ast_variable *ast_http_get_post_vars(
611         struct ast_tcptls_session_instance *ser, struct ast_variable *headers)
612 {
613         int content_length = 0;
614         struct ast_variable *v, *post_vars=NULL, *prev = NULL;
615         char *buf, *var, *val;
616         int res;
617
618         for (v = headers; v; v = v->next) {
619                 if (!strcasecmp(v->name, "Content-Type")) {
620                         if (strcasecmp(v->value, "application/x-www-form-urlencoded")) {
621                                 return NULL;
622                         }
623                         break;
624                 }
625         }
626
627         for (v = headers; v; v = v->next) {
628                 if (!strcasecmp(v->name, "Content-Length")) {
629                         content_length = atoi(v->value);
630                         break;
631                 }
632         }
633
634         if (content_length <= 0) {
635                 return NULL;
636         }
637
638         if (content_length > MAX_POST_CONTENT - 1) {
639                 ast_log(LOG_WARNING, "Excessively long HTTP content. %d is greater than our max of %d\n",
640                                 content_length, MAX_POST_CONTENT);
641                 ast_http_send(ser, AST_HTTP_POST, 413, "Request Entity Too Large", NULL, NULL, 0, 0);
642                 return NULL;
643         }
644
645         buf = ast_malloc(content_length + 1);
646         if (!buf) {
647                 return NULL;
648         }
649
650         res = fread(buf, 1, content_length, ser->f);
651         if (res < content_length) {
652                 /* Error, distinguishable by ferror() or feof(), but neither
653                  * is good. */
654                 goto done;
655         }
656         buf[content_length] = '\0';
657
658         while ((val = strsep(&buf, "&"))) {
659                 var = strsep(&val, "=");
660                 if (val) {
661                         ast_uri_decode(val, ast_uri_http_legacy);
662                 } else  {
663                         val = "";
664                 }
665                 ast_uri_decode(var, ast_uri_http_legacy);
666                 if ((v = ast_variable_new(var, val, ""))) {
667                         if (post_vars) {
668                                 prev->next = v;
669                         } else {
670                                 post_vars = v;
671                         }
672                         prev = v;
673                 }
674         }
675         
676 done:
677         ast_free(buf);
678         return post_vars;
679 }
680
681 static int handle_uri(struct ast_tcptls_session_instance *ser, char *uri,
682         enum ast_http_method method, struct ast_variable *headers)
683 {
684         char *c;
685         int res = -1;
686         char *params = uri;
687         struct ast_http_uri *urih = NULL;
688         int l;
689         struct ast_variable *get_vars = NULL, *v, *prev = NULL;
690         struct http_uri_redirect *redirect;
691
692         ast_debug(2, "HTTP Request URI is %s \n", uri);
693
694         strsep(&params, "?");
695         /* Extract arguments from the request and store them in variables. */
696         if (params) {
697                 char *var, *val;
698
699                 while ((val = strsep(&params, "&"))) {
700                         var = strsep(&val, "=");
701                         if (val) {
702                                 ast_uri_decode(val, ast_uri_http_legacy);
703                         } else  {
704                                 val = "";
705                         }
706                         ast_uri_decode(var, ast_uri_http_legacy);
707                         if ((v = ast_variable_new(var, val, ""))) {
708                                 if (get_vars) {
709                                         prev->next = v;
710                                 } else {
711                                         get_vars = v;
712                                 }
713                                 prev = v;
714                         }
715                 }
716         }
717         ast_uri_decode(uri, ast_uri_http_legacy);
718
719         AST_RWLIST_RDLOCK(&uri_redirects);
720         AST_RWLIST_TRAVERSE(&uri_redirects, redirect, entry) {
721                 if (!strcasecmp(uri, redirect->target)) {
722                         struct ast_str *http_header = ast_str_create(128);
723                         ast_str_set(&http_header, 0, "Location: %s\r\n", redirect->dest);
724                         ast_http_send(ser, method, 302, "Moved Temporarily", http_header, NULL, 0, 0);
725
726                         break;
727                 }
728         }
729         AST_RWLIST_UNLOCK(&uri_redirects);
730         if (redirect) {
731                 goto cleanup;
732         }
733
734         /* We want requests to start with the (optional) prefix and '/' */
735         l = strlen(prefix);
736         if (!strncasecmp(uri, prefix, l) && uri[l] == '/') {
737                 uri += l + 1;
738                 /* scan registered uris to see if we match one. */
739                 AST_RWLIST_RDLOCK(&uris);
740                 AST_RWLIST_TRAVERSE(&uris, urih, entry) {
741                         ast_debug(2, "match request [%s] with handler [%s] len %d\n", uri, urih->uri, l);
742                         l = strlen(urih->uri);
743                         c = uri + l;    /* candidate */
744                         if (strncasecmp(urih->uri, uri, l) /* no match */
745                             || (*c && *c != '/')) { /* substring */
746                                 continue;
747                         }
748                         if (*c == '/') {
749                                 c++;
750                         }
751                         if (!*c || urih->has_subtree) {
752                                 uri = c;
753                                 break;
754                         }
755                 }
756                 AST_RWLIST_UNLOCK(&uris);
757         }
758         if (urih) {
759                 res = urih->callback(ser, urih, uri, method, get_vars, headers);
760         } else {
761                 ast_http_error(ser, 404, "Not Found", "The requested URL was not found on this server.");
762         }
763
764 cleanup:
765         ast_variables_destroy(get_vars);
766         return res;
767 }
768
769 #ifdef DO_SSL
770 #if defined(HAVE_FUNOPEN)
771 #define HOOK_T int
772 #define LEN_T int
773 #else
774 #define HOOK_T ssize_t
775 #define LEN_T size_t
776 #endif
777
778 /*!
779  * replacement read/write functions for SSL support.
780  * We use wrappers rather than SSL_read/SSL_write directly so
781  * we can put in some debugging.
782  */
783 /*static HOOK_T ssl_read(void *cookie, char *buf, LEN_T len)
784 {
785         int i = SSL_read(cookie, buf, len-1);
786 #if 0
787         if (i >= 0)
788                 buf[i] = '\0';
789         ast_verbose("ssl read size %d returns %d <%s>\n", (int)len, i, buf);
790 #endif
791         return i;
792 }
793
794 static HOOK_T ssl_write(void *cookie, const char *buf, LEN_T len)
795 {
796 #if 0
797         char *s = ast_alloca(len+1);
798         strncpy(s, buf, len);
799         s[len] = '\0';
800         ast_verbose("ssl write size %d <%s>\n", (int)len, s);
801 #endif
802         return SSL_write(cookie, buf, len);
803 }
804
805 static int ssl_close(void *cookie)
806 {
807         close(SSL_get_fd(cookie));
808         SSL_shutdown(cookie);
809         SSL_free(cookie);
810         return 0;
811 }*/
812 #endif  /* DO_SSL */
813
814 static struct ast_variable *parse_cookies(char *cookies)
815 {
816         char *cur;
817         struct ast_variable *vars = NULL, *var;
818
819         while ((cur = strsep(&cookies, ";"))) {
820                 char *name, *val;
821
822                 name = val = cur;
823                 strsep(&val, "=");
824
825                 if (ast_strlen_zero(name) || ast_strlen_zero(val)) {
826                         continue;
827                 }
828
829                 name = ast_strip(name);
830                 val = ast_strip_quoted(val, "\"", "\"");
831
832                 if (ast_strlen_zero(name) || ast_strlen_zero(val)) {
833                         continue;
834                 }
835
836                 ast_debug(1, "HTTP Cookie, Name: '%s'  Value: '%s'\n", name, val);
837
838                 var = ast_variable_new(name, val, __FILE__);
839                 var->next = vars;
840                 vars = var;
841         }
842
843         return vars;
844 }
845
846 /* get cookie from Request headers */
847 struct ast_variable *ast_http_get_cookies(struct ast_variable *headers)
848 {
849         struct ast_variable *v, *cookies=NULL;
850
851         for (v = headers; v; v = v->next) {
852                 if (!strncasecmp(v->name, "Cookie", 6)) {
853                         char *tmp = ast_strdupa(v->value);
854                         if (cookies) {
855                                 ast_variables_destroy(cookies);
856                         }
857
858                         cookies = parse_cookies(tmp);
859                 }
860         }
861         return cookies;
862 }
863
864
865 static void *httpd_helper_thread(void *data)
866 {
867         char buf[4096];
868         char header_line[4096];
869         struct ast_tcptls_session_instance *ser = data;
870         struct ast_variable *headers = NULL;
871         struct ast_variable *tail = headers;
872         char *uri, *method;
873         enum ast_http_method http_method = AST_HTTP_UNKNOWN;
874
875         if (ast_atomic_fetchadd_int(&session_count, +1) >= session_limit) {
876                 goto done;
877         }
878
879         if (!fgets(buf, sizeof(buf), ser->f)) {
880                 goto done;
881         }
882
883         /* Get method */
884         method = ast_skip_blanks(buf);
885         uri = ast_skip_nonblanks(method);
886         if (*uri) {
887                 *uri++ = '\0';
888         }
889
890         if (!strcasecmp(method,"GET")) {
891                 http_method = AST_HTTP_GET;
892         } else if (!strcasecmp(method,"POST")) {
893                 http_method = AST_HTTP_POST;
894         } else if (!strcasecmp(method,"HEAD")) {
895                 http_method = AST_HTTP_HEAD;
896         } else if (!strcasecmp(method,"PUT")) {
897                 http_method = AST_HTTP_PUT;
898         }
899
900         uri = ast_skip_blanks(uri);     /* Skip white space */
901
902         if (*uri) {                     /* terminate at the first blank */
903                 char *c = ast_skip_nonblanks(uri);
904
905                 if (*c) {
906                         *c = '\0';
907                 }
908         }
909
910         /* process "Request Headers" lines */
911         while (fgets(header_line, sizeof(header_line), ser->f)) {
912                 char *name, *value;
913
914                 /* Trim trailing characters */
915                 ast_trim_blanks(header_line);
916                 if (ast_strlen_zero(header_line)) {
917                         break;
918                 }
919
920                 value = header_line;
921                 name = strsep(&value, ":");
922                 if (!value) {
923                         continue;
924                 }
925
926                 value = ast_skip_blanks(value);
927                 if (ast_strlen_zero(value) || ast_strlen_zero(name)) {
928                         continue;
929                 }
930
931                 ast_trim_blanks(name);
932
933                 if (!headers) {
934                         headers = ast_variable_new(name, value, __FILE__);
935                         tail = headers;
936                 } else {
937                         tail->next = ast_variable_new(name, value, __FILE__);
938                         tail = tail->next;
939                 }
940         }
941
942         if (!*uri) {
943                 ast_http_error(ser, 400, "Bad Request", "Invalid Request");
944                 goto done;
945         }
946
947         handle_uri(ser, uri, http_method, headers);
948
949 done:
950         ast_atomic_fetchadd_int(&session_count, -1);
951
952         /* clean up all the header information */
953         if (headers) {
954                 ast_variables_destroy(headers);
955         }
956
957         if (ser->f) {
958                 fclose(ser->f);
959         }
960         ao2_ref(ser, -1);
961         ser = NULL;
962         return NULL;
963 }
964
965 /*!
966  * \brief Add a new URI redirect
967  * The entries in the redirect list are sorted by length, just like the list
968  * of URI handlers.
969  */
970 static void add_redirect(const char *value)
971 {
972         char *target, *dest;
973         struct http_uri_redirect *redirect, *cur;
974         unsigned int target_len;
975         unsigned int total_len;
976
977         dest = ast_strdupa(value);
978         dest = ast_skip_blanks(dest);
979         target = strsep(&dest, " ");
980         target = ast_skip_blanks(target);
981         target = strsep(&target, " "); /* trim trailing whitespace */
982
983         if (!dest) {
984                 ast_log(LOG_WARNING, "Invalid redirect '%s'\n", value);
985                 return;
986         }
987
988         target_len = strlen(target) + 1;
989         total_len = sizeof(*redirect) + target_len + strlen(dest) + 1;
990
991         if (!(redirect = ast_calloc(1, total_len))) {
992                 return;
993         }
994         redirect->dest = redirect->target + target_len;
995         strcpy(redirect->target, target);
996         strcpy(redirect->dest, dest);
997
998         AST_RWLIST_WRLOCK(&uri_redirects);
999
1000         target_len--; /* So we can compare directly with strlen() */
1001         if (AST_RWLIST_EMPTY(&uri_redirects)
1002                 || strlen(AST_RWLIST_FIRST(&uri_redirects)->target) <= target_len ) {
1003                 AST_RWLIST_INSERT_HEAD(&uri_redirects, redirect, entry);
1004                 AST_RWLIST_UNLOCK(&uri_redirects);
1005
1006                 return;
1007         }
1008
1009         AST_RWLIST_TRAVERSE(&uri_redirects, cur, entry) {
1010                 if (AST_RWLIST_NEXT(cur, entry)
1011                         && strlen(AST_RWLIST_NEXT(cur, entry)->target) <= target_len ) {
1012                         AST_RWLIST_INSERT_AFTER(&uri_redirects, cur, redirect, entry);
1013                         AST_RWLIST_UNLOCK(&uri_redirects);
1014                         return;
1015                 }
1016         }
1017
1018         AST_RWLIST_INSERT_TAIL(&uri_redirects, redirect, entry);
1019
1020         AST_RWLIST_UNLOCK(&uri_redirects);
1021 }
1022
1023 static int __ast_http_load(int reload)
1024 {
1025         struct ast_config *cfg;
1026         struct ast_variable *v;
1027         int enabled=0;
1028         int newenablestatic=0;
1029         char newprefix[MAX_PREFIX] = "";
1030         struct http_uri_redirect *redirect;
1031         struct ast_flags config_flags = { reload ? CONFIG_FLAG_FILEUNCHANGED : 0 };
1032         uint32_t bindport = DEFAULT_PORT;
1033         struct ast_sockaddr *addrs = NULL;
1034         int num_addrs = 0;
1035         int http_tls_was_enabled = 0;
1036
1037         cfg = ast_config_load2("http.conf", "http", config_flags);
1038         if (cfg == CONFIG_STATUS_FILEMISSING || cfg == CONFIG_STATUS_FILEUNCHANGED || cfg == CONFIG_STATUS_FILEINVALID) {
1039                 return 0;
1040         }
1041
1042         http_tls_was_enabled = (reload && http_tls_cfg.enabled);
1043
1044         http_tls_cfg.enabled = 0;
1045         if (http_tls_cfg.certfile) {
1046                 ast_free(http_tls_cfg.certfile);
1047         }
1048         http_tls_cfg.certfile = ast_strdup(AST_CERTFILE);
1049
1050         if (http_tls_cfg.pvtfile) {
1051                 ast_free(http_tls_cfg.pvtfile);
1052         }
1053         http_tls_cfg.pvtfile = ast_strdup("");
1054
1055         if (http_tls_cfg.cipher) {
1056                 ast_free(http_tls_cfg.cipher);
1057         }
1058         http_tls_cfg.cipher = ast_strdup("");
1059
1060         AST_RWLIST_WRLOCK(&uri_redirects);
1061         while ((redirect = AST_RWLIST_REMOVE_HEAD(&uri_redirects, entry))) {
1062                 ast_free(redirect);
1063         }
1064         AST_RWLIST_UNLOCK(&uri_redirects);
1065
1066         ast_sockaddr_setnull(&https_desc.local_address);
1067
1068         if (cfg) {
1069                 v = ast_variable_browse(cfg, "general");
1070                 for (; v; v = v->next) {
1071
1072                         /* read tls config options while preventing unsupported options from being set */
1073                         if (strcasecmp(v->name, "tlscafile")
1074                                 && strcasecmp(v->name, "tlscapath")
1075                                 && strcasecmp(v->name, "tlscadir")
1076                                 && strcasecmp(v->name, "tlsverifyclient")
1077                                 && strcasecmp(v->name, "tlsdontverifyserver")
1078                                 && strcasecmp(v->name, "tlsclientmethod")
1079                                 && strcasecmp(v->name, "sslclientmethod")
1080                                 && strcasecmp(v->name, "tlscipher")
1081                                 && strcasecmp(v->name, "sslcipher")
1082                                 && !ast_tls_read_conf(&http_tls_cfg, &https_desc, v->name, v->value)) {
1083                                 continue;
1084                         }
1085
1086                         if (!strcasecmp(v->name, "enabled")) {
1087                                 enabled = ast_true(v->value);
1088                         } else if (!strcasecmp(v->name, "enablestatic")) {
1089                                 newenablestatic = ast_true(v->value);
1090                         } else if (!strcasecmp(v->name, "bindport")) {
1091                                 if (ast_parse_arg(v->value, PARSE_UINT32 | PARSE_IN_RANGE | PARSE_DEFAULT, &bindport, DEFAULT_PORT, 0, 65535)) {
1092                                         ast_log(LOG_WARNING, "Invalid port %s specified. Using default port %"PRId32, v->value, DEFAULT_PORT);
1093                                 }
1094                         } else if (!strcasecmp(v->name, "bindaddr")) {
1095                                 if (!(num_addrs = ast_sockaddr_resolve(&addrs, v->value, 0, AST_AF_UNSPEC))) {
1096                                         ast_log(LOG_WARNING, "Invalid bind address %s\n", v->value);
1097                                 }
1098                         } else if (!strcasecmp(v->name, "prefix")) {
1099                                 if (!ast_strlen_zero(v->value)) {
1100                                         newprefix[0] = '/';
1101                                         ast_copy_string(newprefix + 1, v->value, sizeof(newprefix) - 1);
1102                                 } else {
1103                                         newprefix[0] = '\0';
1104                                 }
1105                         } else if (!strcasecmp(v->name, "redirect")) {
1106                                 add_redirect(v->value);
1107                         } else if (!strcasecmp(v->name, "sessionlimit")) {
1108                                 if (ast_parse_arg(v->value, PARSE_INT32|PARSE_DEFAULT|PARSE_IN_RANGE,
1109                                                         &session_limit, DEFAULT_SESSION_LIMIT, 1, INT_MAX)) {
1110                                         ast_log(LOG_WARNING, "Invalid %s '%s' at line %d of http.conf\n",
1111                                                         v->name, v->value, v->lineno);
1112                                 }
1113                         } else {
1114                                 ast_log(LOG_WARNING, "Ignoring unknown option '%s' in http.conf\n", v->name);
1115                         }
1116                 }
1117
1118                 ast_config_destroy(cfg);
1119         }
1120
1121         if (strcmp(prefix, newprefix)) {
1122                 ast_copy_string(prefix, newprefix, sizeof(prefix));
1123         }
1124         enablestatic = newenablestatic;
1125
1126         if (num_addrs && enabled) {
1127                 int i;
1128                 for (i = 0; i < num_addrs; ++i) {
1129                         ast_sockaddr_copy(&http_desc.local_address, &addrs[i]);
1130                         if (!ast_sockaddr_port(&http_desc.local_address)) {
1131                                 ast_sockaddr_set_port(&http_desc.local_address, bindport);
1132                         }
1133                         ast_tcptls_server_start(&http_desc);
1134                         if (http_desc.accept_fd == -1) {
1135                                 ast_log(LOG_WARNING, "Failed to start HTTP server for address %s\n", ast_sockaddr_stringify(&addrs[i]));
1136                                 ast_sockaddr_setnull(&http_desc.local_address);
1137                         } else {
1138                                 ast_verb(1, "Bound HTTP server to address %s\n", ast_sockaddr_stringify(&addrs[i]));
1139                                 break;
1140                         }
1141                 }
1142                 /* When no specific TLS bindaddr is specified, we just use
1143                  * the non-TLS bindaddress here.
1144                  */
1145                 if (ast_sockaddr_isnull(&https_desc.local_address) && http_desc.accept_fd != -1) {
1146                         ast_sockaddr_copy(&https_desc.local_address, &https_desc.local_address);
1147                         /* Of course, we can't use the same port though.
1148                          * Since no bind address was specified, we just use the
1149                          * default TLS port
1150                          */
1151                         ast_sockaddr_set_port(&https_desc.local_address, DEFAULT_TLS_PORT);
1152                 }
1153         }
1154         if (http_tls_was_enabled && !http_tls_cfg.enabled) {
1155                 ast_tcptls_server_stop(&https_desc);
1156         } else if (http_tls_cfg.enabled && !ast_sockaddr_isnull(&https_desc.local_address)) {
1157                 /* We can get here either because a TLS-specific address was specified
1158                  * or because we copied the non-TLS address here. In the case where
1159                  * we read an explicit address from the config, there may have been
1160                  * no port specified, so we'll just use the default TLS port.
1161                  */
1162                 if (!ast_sockaddr_port(&https_desc.local_address)) {
1163                         ast_sockaddr_set_port(&https_desc.local_address, DEFAULT_TLS_PORT);
1164                 }
1165                 if (ast_ssl_setup(https_desc.tls_cfg)) {
1166                         ast_tcptls_server_start(&https_desc);
1167                 }
1168         }
1169
1170         return 0;
1171 }
1172
1173 static char *handle_show_http(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
1174 {
1175         struct ast_http_uri *urih;
1176         struct http_uri_redirect *redirect;
1177
1178         switch (cmd) {
1179         case CLI_INIT:
1180                 e->command = "http show status";
1181                 e->usage =
1182                         "Usage: http show status\n"
1183                         "       Lists status of internal HTTP engine\n";
1184                 return NULL;
1185         case CLI_GENERATE:
1186                 return NULL;
1187         }
1188
1189         if (a->argc != 3) {
1190                 return CLI_SHOWUSAGE;
1191         }
1192         ast_cli(a->fd, "HTTP Server Status:\n");
1193         ast_cli(a->fd, "Prefix: %s\n", prefix);
1194         if (ast_sockaddr_isnull(&http_desc.old_address)) {
1195                 ast_cli(a->fd, "Server Disabled\n\n");
1196         } else {
1197                 ast_cli(a->fd, "Server Enabled and Bound to %s\n\n",
1198                         ast_sockaddr_stringify(&http_desc.old_address));
1199                 if (http_tls_cfg.enabled) {
1200                         ast_cli(a->fd, "HTTPS Server Enabled and Bound to %s\n\n",
1201                                 ast_sockaddr_stringify(&https_desc.old_address));
1202                 }
1203         }
1204
1205         ast_cli(a->fd, "Enabled URI's:\n");
1206         AST_RWLIST_RDLOCK(&uris);
1207         if (AST_RWLIST_EMPTY(&uris)) {
1208                 ast_cli(a->fd, "None.\n");
1209         } else {
1210                 AST_RWLIST_TRAVERSE(&uris, urih, entry)
1211                         ast_cli(a->fd, "%s/%s%s => %s\n", prefix, urih->uri, (urih->has_subtree ? "/..." : "" ), urih->description);
1212         }
1213         AST_RWLIST_UNLOCK(&uris);
1214
1215         ast_cli(a->fd, "\nEnabled Redirects:\n");
1216         AST_RWLIST_RDLOCK(&uri_redirects);
1217         AST_RWLIST_TRAVERSE(&uri_redirects, redirect, entry)
1218                 ast_cli(a->fd, "  %s => %s\n", redirect->target, redirect->dest);
1219         if (AST_RWLIST_EMPTY(&uri_redirects)) {
1220                 ast_cli(a->fd, "  None.\n");
1221         }
1222         AST_RWLIST_UNLOCK(&uri_redirects);
1223
1224         return CLI_SUCCESS;
1225 }
1226
1227 int ast_http_reload(void)
1228 {
1229         return __ast_http_load(1);
1230 }
1231
1232 static struct ast_cli_entry cli_http[] = {
1233         AST_CLI_DEFINE(handle_show_http, "Display HTTP server status"),
1234 };
1235
1236 static void http_shutdown(void)
1237 {
1238         ast_cli_unregister_multiple(cli_http, ARRAY_LEN(cli_http));
1239 }
1240
1241 int ast_http_init(void)
1242 {
1243         ast_http_uri_link(&statusuri);
1244         ast_http_uri_link(&staticuri);
1245         ast_cli_register_multiple(cli_http, ARRAY_LEN(cli_http));
1246         ast_register_atexit(http_shutdown);
1247
1248         return __ast_http_load(0);
1249 }