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
  22  *
  23  * This program implements a tiny http server supporting the "get" method
  24  * only and was inspired by micro-httpd by Jef Poskanzer
  25  */
  26
  27 #include <sys/types.h>
  28 #include <stdio.h>
  29 #include <unistd.h>
  30 #include <stdlib.h>
  31 #include <time.h>
  32 #include <string.h>
  33 #include <netinet/in.h>
  34 #include <sys/time.h>
  35 #include <sys/socket.h>
  36 #include <sys/signal.h>
  37 #include <arpa/inet.h>
  38 #include <errno.h>
  39 #include <fcntl.h>
  40 #include <pthread.h>
  41
  42 #include "asterisk/cli.h"
  43 #include "asterisk/http.h"
  44 #include "asterisk/utils.h"
  45 #include "asterisk/strings.h"
  46
  47 #define MAX_PREFIX 80
  48 #define DEFAULT_PREFIX "asterisk"
  49
  50 struct ast_http_server_instance {
  51         FILE *f;
  52         int fd;
  53         struct sockaddr_in requestor;
  54         ast_http_callback callback;
  55 };
  56
  57 static struct ast_http_uri *uris;
  58
  59 static int httpfd = -1;
  60 static pthread_t master = AST_PTHREADT_NULL;
  61 static char prefix[MAX_PREFIX];
  62 static int prefix_len = 0;
  63 static struct sockaddr_in oldsin;
  64
  65
  66 static char *httpstatus_callback(struct sockaddr_in *req, const char *uri, struct ast_variable *vars, int *status, char **title, int *contentlength)
  67 {
  68         char result[4096];
  69         size_t reslen = sizeof(result);
  70         char *c=result;
  71         struct ast_variable *v;
  72         char iabuf[INET_ADDRSTRLEN];
  73
  74         ast_build_string(&c, &reslen,
  75                 "\r\n"
  76                 "<title>Asterisk HTTP Status</title>\r\n"
  77                 "<body bgcolor=\"#ffffff\">\r\n"
  78                 "<table bgcolor=\"#f1f1f1\" align=\"center\"><tr><td bgcolor=\"#e0e0ff\" colspan=\"2\" width=\"500\">\r\n"
  79                 "<h2>&nbsp;&nbsp;Asterisk&trade; HTTP Status</h2></td></tr>\r\n");
  80
  81         ast_build_string(&c, &reslen, "<tr><td><i>Prefix</i></td><td><b>%s</b></td></tr>\r\n", prefix);
  82         ast_build_string(&c, &reslen, "<tr><td><i>Bind Address</i></td><td><b>%s</b></td></tr>\r\n",
  83                         ast_inet_ntoa(iabuf, sizeof(iabuf), oldsin.sin_addr));
  84         ast_build_string(&c, &reslen, "<tr><td><i>Bind Port</i></td><td><b>%d</b></td></tr>\r\n",
  85                         ntohs(oldsin.sin_port));
  86         ast_build_string(&c, &reslen, "<tr><td colspan=\"2\"><hr></td></tr>\r\n");
  87         v = vars;
  88         while(v) {
  89                 ast_build_string(&c, &reslen, "<tr><td><i>Submitted Variable '%s'</i></td><td>%s</td></tr>\r\n", v->name, v->value);
  90                 v = v->next;
  91         }
  92         ast_build_string(&c, &reslen, "</table><center><font size=\"-1\"><i>Asterisk and Digium are registered trademarks of Digium, Inc.</i></font></center></body>\r\n");
  93         return strdup(result);
  94 }
  95
  96 static struct ast_http_uri statusuri = {
  97         .callback = httpstatus_callback,
  98         .description = "Asterisk HTTP General Status",
  99         .uri = "httpstatus",
 100         .has_subtree = 0,
 101 };
 102
 103 char *ast_http_error(int status, const char *title, const char *extra_header, const char *text)
 104 {
 105         char *c = NULL;
 106         asprintf(&c,
 107                 "Content-type: text/html\r\n"
 108                 "%s"
 109                 "\r\n"
 110                 "<!DOCTYPE HTML PUBLIC \"-//IETF//DTD HTML 2.0//EN\">\r\n"
 111                 "<html><head>\r\n"
 112                 "<title>%d %s</title>\r\n"
 113                 "</head><body>\r\n"
 114                 "<h1>%s</h1>\r\n"
 115                 "<p>%s</p>\r\n"
 116                 "<hr />\r\n"
 117                 "<address>Asterisk Server</address>\r\n"
 118                 "</body></html>\r\n",
 119                         (extra_header ? extra_header : ""), status, title, title, text);
 120         return c;
 121 }
 122
 123 int ast_http_uri_link(struct ast_http_uri *urih)
 124 {
 125         struct ast_http_uri *prev=uris;
 126         if (!uris || strlen(uris->uri) <= strlen(urih->uri)) {
 127                 urih->next = uris;
 128                 uris = urih;
 129         } else {
 130                 while (prev->next && (strlen(prev->next->uri) > strlen(urih->uri)))
 131                         prev = prev->next;
 132                 /* Insert it here */
 133                 urih->next = prev->next;
 134                 prev->next = urih;
 135         }
 136         return 0;
 137 }
 138
 139 void ast_http_uri_unlink(struct ast_http_uri *urih)
 140 {
 141         struct ast_http_uri *prev = uris;
 142         if (!uris)
 143                 return;
 144         if (uris == urih) {
 145                 uris = uris->next;
 146         }
 147         while(prev->next) {
 148                 if (prev->next == urih) {
 149                         prev->next = urih->next;
 150                         break;
 151                 }
 152                 prev = prev->next;
 153         }
 154 }
 155
 156 static char *handle_uri(struct sockaddr_in *sin, char *uri, int *status, char **title, int *contentlength)
 157 {
 158         char *c;
 159         char *turi;
 160         char *params;
 161         char *var;
 162         char *val;
 163         struct ast_http_uri *urih=NULL;
 164         int len;
 165         struct ast_variable *vars=NULL, *v, *prev = NULL;
 166
 167
 168         if (*uri == '/')
 169                 uri++;
 170         params = strchr(uri, '?');
 171         if (params) {
 172                 *params = '\0';
 173                 params++;
 174                 while ((var = strsep(&params, "&"))) {
 175                         val = strchr(var, '=');
 176                         if (val) {
 177                                 *val = '\0';
 178                                 val++;
 179                         } else
 180                                 val = "";
 181                         ast_uri_decode(val);
 182                         ast_uri_decode(var);
 183                         if ((v = ast_variable_new(var, val))) {
 184                                 if (vars)
 185                                         prev->next = v;
 186                                 else
 187                                         vars = v;
 188                                 prev = v;
 189                         }
 190                 }
 191         }
 192         ast_uri_decode(uri);
 193         if (!strncasecmp(uri, prefix, prefix_len)) {
 194                 uri += prefix_len;
 195                 if (!*uri || (*uri == '/')) {
 196                         if (*uri == '/')
 197                                 uri++;
 198                         urih = uris;
 199                         while(urih) {
 200                                 len = strlen(urih->uri);
 201                                 if (!strncasecmp(urih->uri, uri, len)) {
 202                                         if (!uri[len] || uri[len] == '/') {
 203                                                 turi = uri + len;
 204                                                 if (*turi == '/')
 205                                                         turi++;
 206                                                 if (!*turi || urih->has_subtree) {
 207                                                         uri = turi;
 208                                                         break;
 209                                                 }
 210                                         }
 211                                 }
 212                                 urih = urih->next;
 213                         }
 214                 }
 215         }
 216         if (urih) {
 217                 c = urih->callback(sin, uri, vars, status, title, contentlength);
 218                 ast_variables_destroy(vars);
 219         } else {
 220                 c = ast_http_error(404, "Not Found", NULL, "The requested URL was not found on this serer.");
 221                 *status = 404;
 222                 *title = strdup("Not Found");
 223         }
 224         return c;
 225 }
 226
 227 static void *ast_httpd_helper_thread(void *data)
 228 {
 229         char buf[4096];
 230         char timebuf[256];
 231         struct ast_http_server_instance *ser = data;
 232         char *uri, *c, *title=NULL;
 233         int status = 200, contentlength = 0;
 234         time_t t;
 235
 236         if (fgets(buf, sizeof(buf), ser->f)) {
 237                 /* Skip method */
 238                 uri = buf;
 239                 while(*uri && (*uri > 32)) uri++;
 240                 if (*uri) {
 241                         *uri = '\0';
 242                         uri++;
 243                 }
 244
 245                 /* Skip white space */
 246                 while (*uri && (*uri < 33)) uri++;
 247
 248                 if (*uri) {
 249                         c = uri;
 250                         while (*c && (*c > 32)) c++;
 251                         if (*c) {
 252                                 *c = '\0';
 253                         }
 254                 }
 255                 if (*uri) {
 256                         if (!strcasecmp(buf, "get"))
 257                                 c = handle_uri(&ser->requestor, uri, &status, &title, &contentlength);
 258                         else
 259                                 c = ast_http_error(501, "Not Implemented", NULL, "Attempt to use unimplemented / unsupported method");\
 260                 } else
 261                         c = ast_http_error(400, "Bad Request", NULL, "Invalid Request");
 262                 if (!c)
 263                         c = ast_http_error(500, "Internal Error", NULL, "Internal Server Error");
 264                 if (c) {
 265                         time(&t);
 266                         strftime(timebuf, sizeof(timebuf), "%a, %d %b %Y %H:%M:%S GMT", gmtime(&t));
 267                         ast_cli(ser->fd, "HTTP/1.1 GET %d %s\r\n", status, title ? title : "OK");
 268                         ast_cli(ser->fd, "Server: Asterisk\r\n");
 269                         ast_cli(ser->fd, "Date: %s\r\n", timebuf);
 270                         if (contentlength)
 271                                 ast_cli(ser->fd, "Content-length: %d\r\n", contentlength);
 272                         ast_cli(ser->fd, "Connection: close\r\n");
 273                         ast_cli(ser->fd, "%s", c);
 274                         free(c);
 275                 }
 276                 if (title)
 277                         free(title);
 278         }
 279         fclose(ser->f);
 280         free(ser);
 281         return NULL;
 282 }
 283
 284 static void *http_root(void *data)
 285 {
 286         int fd;
 287         struct sockaddr_in sin;
 288         int sinlen;
 289         struct ast_http_server_instance *ser;
 290         pthread_t launched;
 291         for (;;) {
 292                 ast_wait_for_input(httpfd, -1);
 293                 sinlen = sizeof(sin);
 294                 fd = accept(httpfd, (struct sockaddr *)&sin, &sinlen);
 295                 if (fd < 0) {
 296                         if ((errno != EAGAIN) && (errno != EINTR))
 297                                 ast_log(LOG_WARNING, "Accept failed: %s\n", strerror(errno));
 298                         continue;
 299                 }
 300                 if (!(ser = ast_calloc(1, sizeof(*ser)))) {
 301                         close(fd);
 302                         continue;
 303                 }
 304                 ser->fd = fd;
 305                 if ((ser->f = fdopen(ser->fd, "w+"))) {
 306                         if (ast_pthread_create(&launched, NULL, ast_httpd_helper_thread, ser)) {
 307                                 ast_log(LOG_WARNING, "Unable to launch helper thread: %s\n", strerror(errno));
 308                                 fclose(ser->f);
 309                                 free(ser);
 310                         }
 311                 } else {
 312                         ast_log(LOG_WARNING, "fdopen failed!\n");
 313                         close(ser->fd);
 314                         free(ser);
 315                 }
 316         }
 317         return NULL;
 318 }
 319
 320 static void http_server_start(struct sockaddr_in *sin)
 321 {
 322         char iabuf[INET_ADDRSTRLEN];
 323         int flags;
 324         int x = 1;
 325
 326         /* Do nothing if nothing has changed */
 327         if (!memcmp(&oldsin, sin, sizeof(oldsin))) {
 328                 ast_log(LOG_DEBUG, "Nothing changed in http\n");
 329                 return;
 330         }
 331
 332         memcpy(&oldsin, sin, sizeof(oldsin));
 333
 334         /* Shutdown a running server if there is one */
 335         if (master != AST_PTHREADT_NULL) {
 336                 pthread_cancel(master);
 337                 pthread_kill(master, SIGURG);
 338                 pthread_join(master, NULL);
 339         }
 340
 341         if (httpfd != -1)
 342                 close(httpfd);
 343
 344         /* If there's no new server, stop here */
 345         if (!sin->sin_family)
 346                 return;
 347
 348
 349         httpfd = socket(AF_INET, SOCK_STREAM, 0);
 350         if (httpfd < 0) {
 351                 ast_log(LOG_WARNING, "Unable to allocate socket: %s\n", strerror(errno));
 352                 return;
 353         }
 354
 355         setsockopt(httpfd, SOL_SOCKET, SO_REUSEADDR, &x, sizeof(x));
 356         if (bind(httpfd, (struct sockaddr *)sin, sizeof(*sin))) {
 357                 ast_log(LOG_NOTICE, "Unable to bind http server to %s:%d: %s\n",
 358                         ast_inet_ntoa(iabuf, sizeof(iabuf), sin->sin_addr), ntohs(sin->sin_port),
 359                         strerror(errno));
 360                 close(httpfd);
 361                 httpfd = -1;
 362                 return;
 363         }
 364         if (listen(httpfd, 10)) {
 365                 ast_log(LOG_NOTICE, "Unable to listen!\n");
 366                 close(httpfd);
 367                 httpfd = -1;
 368                 return;
 369         }
 370         flags = fcntl(httpfd, F_GETFL);
 371         fcntl(httpfd, F_SETFL, flags | O_NONBLOCK);
 372         if (ast_pthread_create(&master, NULL, http_root, NULL)) {
 373                 ast_log(LOG_NOTICE, "Unable to launch http server on %s:%d: %s\n",
 374                                 ast_inet_ntoa(iabuf, sizeof(iabuf), sin->sin_addr), ntohs(sin->sin_port),
 375                                 strerror(errno));
 376                 close(httpfd);
 377                 httpfd = -1;
 378         }
 379 }
 380
 381 static int __ast_http_load(int reload)
 382 {
 383         struct ast_config *cfg;
 384         struct ast_variable *v;
 385         int enabled=0;
 386         struct sockaddr_in sin;
 387         struct hostent *hp;
 388         struct ast_hostent ahp;
 389         char newprefix[MAX_PREFIX];
 390         memset(&sin, 0, sizeof(sin));
 391         sin.sin_port = 8088;
 392         strcpy(newprefix, DEFAULT_PREFIX);
 393         cfg = ast_config_load("http.conf");
 394         if (cfg) {
 395                 v = ast_variable_browse(cfg, "general");
 396                 while(v) {
 397                         if (!strcasecmp(v->name, "enabled"))
 398                                 enabled = ast_true(v->value);
 399                         else if (!strcasecmp(v->name, "bindport"))
 400                                 sin.sin_port = ntohs(atoi(v->value));
 401                         else if (!strcasecmp(v->name, "bindaddr")) {
 402                                 if ((hp = ast_gethostbyname(v->value, &ahp))) {
 403                                         memcpy(&sin.sin_addr, hp->h_addr, sizeof(sin.sin_addr));
 404                                 } else {
 405                                         ast_log(LOG_WARNING, "Invalid bind address '%s'\n", v->value);
 406                                 }
 407                         } else if (!strcasecmp(v->name, "prefix"))
 408                                 ast_copy_string(newprefix, v->value, sizeof(newprefix));
 409                         v = v->next;
 410                 }
 411                 ast_config_destroy(cfg);
 412         }
 413         if (enabled)
 414                 sin.sin_family = AF_INET;
 415         if (strcmp(prefix, newprefix)) {
 416                 ast_copy_string(prefix, newprefix, sizeof(prefix));
 417                 prefix_len = strlen(prefix);
 418         }
 419         http_server_start(&sin);
 420         return 0;
 421 }
 422
 423 static int handle_show_http(int fd, int argc, char *argv[])
 424 {
 425         char iabuf[INET_ADDRSTRLEN];
 426         struct ast_http_uri *urih;
 427         if (argc != 2)
 428                 return RESULT_SHOWUSAGE;
 429         ast_cli(fd, "HTTP Server Status:\n");
 430         ast_cli(fd, "Prefix: %s\n", prefix);
 431         if (oldsin.sin_family)
 432                 ast_cli(fd, "Server Enabled and Bound to %s:%d\n\n",
 433                         ast_inet_ntoa(iabuf, sizeof(iabuf), oldsin.sin_addr),
 434                         ntohs(oldsin.sin_port));
 435         else
 436                 ast_cli(fd, "Server Disabled\n\n");
 437         ast_cli(fd, "Enabled URI's:\n");
 438         urih = uris;
 439         while(urih){
 440                 ast_cli(fd, "/%s/%s%s => %s\n", prefix, urih->uri, (urih->has_subtree ? "/..." : "" ), urih->description);
 441                 urih = urih->next;
 442         }
 443         if (!uris)
 444                 ast_cli(fd, "None.\n");
 445         return RESULT_SUCCESS;
 446 }
 447
 448 int ast_http_reload(void)
 449 {
 450         return __ast_http_load(1);
 451 }
 452
 453 static char show_http_help[] =
 454 "Usage: show http\n"
 455 "       Shows status of internal HTTP engine\n";
 456
 457 static struct ast_cli_entry http_cli[] = {
 458         { { "show", "http", NULL }, handle_show_http,
 459           "Display HTTP status", show_http_help },
 460 };
 461
 462 int ast_http_init(void)
 463 {
 464         ast_http_uri_link(&statusuri);
 465         ast_cli_register_multiple(http_cli, sizeof(http_cli) / sizeof(http_cli[0]));
 466         return __ast_http_load(0);
 467 }