main.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 #ifndef _DEFAULT_SOURCE
  21 # define _DEFAULT_SOURCE
  22 #endif
  23
  24 #define _BSD_SOURCE
  25 #define _GNU_SOURCE
  26 #define _XOPEN_SOURCE   700
  27 #include <sys/types.h>
  28 #include <sys/socket.h>
  29 #include <netinet/in.h>
  30
  31 #include <getopt.h>
  32 #include <errno.h>
  33 #include <netdb.h>
  34 #include <signal.h>
  35
  36 #include <libubox/usock.h>
  37 #include <libubox/utils.h>
  38
  39 #include "uhttpd.h"
  40 #include "tls.h"
  41
  42 char uh_buf[4096];
  43
  44 static int run_server(void)
  45 {
  46         uloop_init();
  47         uh_setup_listeners();
  48         uh_plugin_post_init();
  49         uloop_run();
  50
  51         return 0;
  52 }
  53
  54 static void uh_config_parse(void)
  55 {
  56         const char *path = conf.file;
  57         FILE *c;
  58         char line[512];
  59         char *col1;
  60         char *col2;
  61         char *eol;
  62
  63         if (!path)
  64                 path = "/etc/httpd.conf";
  65
  66         c = fopen(path, "r");
  67         if (!c)
  68                 return;
  69
  70         memset(line, 0, sizeof(line));
  71
  72         while (fgets(line, sizeof(line) - 1, c)) {
  73                 if ((line[0] == '/') && (strchr(line, ':') != NULL)) {
  74                         if (!(col1 = strchr(line, ':')) || (*col1++ = 0) ||
  75                                 !(col2 = strchr(col1, ':')) || (*col2++ = 0) ||
  76                                 !(eol = strchr(col2, '\n')) || (*eol++  = 0))
  77                                 continue;
  78
  79                         uh_auth_add(line, col1, col2);
  80                 } else if (!strncmp(line, "I:", 2)) {
  81                         if (!(col1 = strchr(line, ':')) || (*col1++ = 0) ||
  82                                 !(eol = strchr(col1, '\n')) || (*eol++  = 0))
  83                                 continue;
  84
  85                         uh_index_add(strdup(col1));
  86                 } else if (!strncmp(line, "E404:", 5)) {
  87                         if (!(col1 = strchr(line, ':')) || (*col1++ = 0) ||
  88                                 !(eol = strchr(col1, '\n')) || (*eol++  = 0))
  89                                 continue;
  90
  91                         conf.error_handler = strdup(col1);
  92                 }
  93                 else if ((line[0] == '*') && (strchr(line, ':') != NULL)) {
  94                         if (!(col1 = strchr(line, '*')) || (*col1++ = 0) ||
  95                                 !(col2 = strchr(col1, ':')) || (*col2++ = 0) ||
  96                                 !(eol = strchr(col2, '\n')) || (*eol++  = 0))
  97                                 continue;
  98
  99                         uh_interpreter_add(col1, col2);
 100                 }
 101         }
 102
 103         fclose(c);
 104 }
 105
 106 static int add_listener_arg(char *arg, bool tls)
 107 {
 108         char *host = NULL;
 109         char *port = arg;
 110         char *s;
 111         int l;
 112
 113         s = strrchr(arg, ':');
 114         if (s) {
 115                 host = arg;
 116                 port = s + 1;
 117                 *s = 0;
 118         }
 119
 120         if (host && *host == '[') {
 121                 l = strlen(host);
 122                 if (l >= 2) {
 123                         host[l-1] = 0;
 124                         host++;
 125                 }
 126         }
 127
 128         return uh_socket_bind(host, port, tls);
 129 }
 130
 131 static int usage(const char *name)
 132 {
 133         fprintf(stderr,
 134                 "Usage: %s -p [addr:]port -h docroot\n"
 135                 "       -f              Do not fork to background\n"
 136                 "       -c file         Configuration file, default is '/etc/httpd.conf'\n"
 137                 "       -p [addr:]port  Bind to specified address and port, multiple allowed\n"
 138 #ifdef HAVE_TLS
 139                 "       -s [addr:]port  Like -p but provide HTTPS on this port\n"
 140                 "       -C file         ASN.1 server certificate file\n"
 141                 "       -K file         ASN.1 server private key file\n"
 142                 "       -q              Redirect all HTTP requests to HTTPS\n"
 143 #endif
 144                 "       -h directory    Specify the document root, default is '.'\n"
 145                 "       -E string       Use given virtual URL as 404 error handler\n"
 146                 "       -I string       Use given filename as index for directories, multiple allowed\n"
 147                 "       -S              Do not follow symbolic links outside of the docroot\n"
 148                 "       -D              Do not allow directory listings, send 403 instead\n"
 149                 "       -R              Enable RFC1918 filter\n"
 150                 "       -n count        Maximum allowed number of concurrent script requests\n"
 151                 "       -N count        Maximum allowed number of concurrent connections\n"
 152 #ifdef HAVE_LUA
 153                 "       -l string       URL prefix for Lua handler, default is '/lua'\n"
 154                 "       -L file         Lua handler script, omit to disable Lua\n"
 155 #endif
 156 #ifdef HAVE_UBUS
 157                 "       -u string       URL prefix for UBUS via JSON-RPC handler\n"
 158                 "       -U file         Override ubus socket path\n"
 159                 "       -a              Do not authenticate JSON-RPC requests against UBUS session api\n"
 160                 "       -X              Enable CORS HTTP headers on JSON-RPC api\n"
 161 #endif
 162                 "       -x string       URL prefix for CGI handler, default is '/cgi-bin'\n"
 163                 "       -y alias[=path] URL alias handle\n"
 164                 "       -i .ext=path    Use interpreter at path for files with the given extension\n"
 165                 "       -t seconds      CGI, Lua and UBUS script timeout in seconds, default is 60\n"
 166                 "       -T seconds      Network timeout in seconds, default is 30\n"
 167                 "       -k seconds      HTTP keepalive timeout\n"
 168                 "       -A seconds      TCP keepalive timeout, default is unset\n"
 169                 "       -d string       URL decode given string\n"
 170                 "       -r string       Specify basic auth realm\n"
 171                 "       -m string       MD5 crypt given string\n"
 172                 "\n", name
 173         );
 174         return 1;
 175 }
 176
 177 static void init_defaults_pre(void)
 178 {
 179         conf.script_timeout = 60;
 180         conf.network_timeout = 30;
 181         conf.http_keepalive = 20;
 182         conf.max_script_requests = 3;
 183         conf.max_connections = 100;
 184         conf.realm = "Protected Area";
 185         conf.cgi_prefix = "/cgi-bin";
 186         conf.cgi_path = "/sbin:/usr/sbin:/bin:/usr/bin";
 187         INIT_LIST_HEAD(&conf.cgi_alias);
 188         INIT_LIST_HEAD(&conf.lua_prefix);
 189 }
 190
 191 static void init_defaults_post(void)
 192 {
 193         uh_index_add("index.html");
 194         uh_index_add("index.htm");
 195         uh_index_add("default.html");
 196         uh_index_add("default.htm");
 197
 198         if (conf.cgi_prefix) {
 199                 char *str = malloc(strlen(conf.docroot) + strlen(conf.cgi_prefix) + 1);
 200
 201                 strcpy(str, conf.docroot);
 202                 strcat(str, conf.cgi_prefix);
 203                 conf.cgi_docroot_path = str;
 204                 conf.cgi_prefix_len = strlen(conf.cgi_prefix);
 205         };
 206 }
 207
 208 static void fixup_prefix(char *str)
 209 {
 210         int len;
 211
 212         if (!str || !str[0])
 213                 return;
 214
 215         len = strlen(str) - 1;
 216
 217         while (len >= 0 && str[len] == '/')
 218                 len--;
 219
 220         str[len + 1] = 0;
 221 }
 222
 223 static void add_lua_prefix(const char *prefix, const char *handler) {
 224         struct lua_prefix *p;
 225         char *pprefix, *phandler;
 226
 227         p = calloc_a(sizeof(*p),
 228                      &pprefix, strlen(prefix) + 1,
 229                      &phandler, strlen(handler) + 1);
 230
 231         if (!p)
 232                 return;
 233
 234         p->prefix = strcpy(pprefix, prefix);
 235         p->handler = strcpy(phandler, handler);
 236
 237         list_add_tail(&p->list, &conf.lua_prefix);
 238 }
 239
 240 int main(int argc, char **argv)
 241 {
 242         struct alias *alias;
 243         bool nofork = false;
 244         char *port;
 245         int opt, ch;
 246         int cur_fd;
 247         int bound = 0;
 248 #ifdef HAVE_TLS
 249         int n_tls = 0;
 250         const char *tls_key = NULL, *tls_crt = NULL;
 251 #endif
 252 #ifdef HAVE_LUA
 253         const char *lua_prefix = NULL, *lua_handler = NULL;
 254 #endif
 255
 256         BUILD_BUG_ON(sizeof(uh_buf) < PATH_MAX);
 257
 258         uh_dispatch_add(&cgi_dispatch);
 259         init_defaults_pre();
 260         signal(SIGPIPE, SIG_IGN);
 261
 262         while ((ch = getopt(argc, argv, "A:aC:c:Dd:E:fh:H:I:i:K:k:L:l:m:N:n:p:qRr:Ss:T:t:U:u:Xx:y:")) != -1) {
 263                 switch(ch) {
 264 #ifdef HAVE_TLS
 265                 case 'C':
 266                         tls_crt = optarg;
 267                         break;
 268
 269                 case 'K':
 270                         tls_key = optarg;
 271                         break;
 272
 273                 case 'q':
 274                         conf.tls_redirect = 1;
 275                         break;
 276
 277                 case 's':
 278                         n_tls++;
 279                         /* fall through */
 280 #else
 281                 case 'C':
 282                 case 'K':
 283                 case 'q':
 284                 case 's':
 285                         fprintf(stderr, "uhttpd: TLS support not compiled, "
 286                                         "ignoring -%c\n", ch);
 287                         break;
 288 #endif
 289                 case 'p':
 290                         optarg = strdup(optarg);
 291                         bound += add_listener_arg(optarg, (ch == 's'));
 292                         break;
 293
 294                 case 'h':
 295                         if (!realpath(optarg, uh_buf)) {
 296                                 fprintf(stderr, "Error: Invalid directory %s: %s\n",
 297                                                 optarg, strerror(errno));
 298                                 exit(1);
 299                         }
 300                         conf.docroot = strdup(uh_buf);
 301                         break;
 302
 303                 case 'H':
 304                         if (uh_handler_add(optarg)) {
 305                                 fprintf(stderr, "Error: Failed to load handler script %s\n",
 306                                         optarg);
 307                                 exit(1);
 308                         }
 309                         break;
 310
 311                 case 'E':
 312                         if (optarg[0] != '/') {
 313                                 fprintf(stderr, "Error: Invalid error handler: %s\n",
 314                                                 optarg);
 315                                 exit(1);
 316                         }
 317                         conf.error_handler = optarg;
 318                         break;
 319
 320                 case 'I':
 321                         if (optarg[0] == '/') {
 322                                 fprintf(stderr, "Error: Invalid index page: %s\n",
 323                                                 optarg);
 324                                 exit(1);
 325                         }
 326                         uh_index_add(optarg);
 327                         break;
 328
 329                 case 'S':
 330                         conf.no_symlinks = 1;
 331                         break;
 332
 333                 case 'D':
 334                         conf.no_dirlists = 1;
 335                         break;
 336
 337                 case 'R':
 338                         conf.rfc1918_filter = 1;
 339                         break;
 340
 341                 case 'n':
 342                         conf.max_script_requests = atoi(optarg);
 343                         break;
 344
 345                 case 'N':
 346                         conf.max_connections = atoi(optarg);
 347                         break;
 348
 349                 case 'x':
 350                         fixup_prefix(optarg);
 351                         conf.cgi_prefix = optarg;
 352                         break;
 353
 354                 case 'y':
 355                         alias = calloc(1, sizeof(*alias));
 356                         if (!alias) {
 357                                 fprintf(stderr, "Error: failed to allocate alias\n");
 358                                 exit(1);
 359                         }
 360                         alias->alias = strdup(optarg);
 361                         alias->path = strchr(alias->alias, '=');
 362                         if (alias->path)
 363                                 *alias->path++ = 0;
 364                         list_add(&alias->list, &conf.cgi_alias);
 365                         break;
 366
 367                 case 'i':
 368                         optarg = strdup(optarg);
 369                         port = strchr(optarg, '=');
 370                         if (optarg[0] != '.' || !port) {
 371                                 fprintf(stderr, "Error: Invalid interpreter: %s\n",
 372                                                 optarg);
 373                                 exit(1);
 374                         }
 375
 376                         *port++ = 0;
 377                         uh_interpreter_add(optarg, port);
 378                         break;
 379
 380                 case 't':
 381                         conf.script_timeout = atoi(optarg);
 382                         break;
 383
 384                 case 'T':
 385                         conf.network_timeout = atoi(optarg);
 386                         break;
 387
 388                 case 'k':
 389                         conf.http_keepalive = atoi(optarg);
 390                         break;
 391
 392                 case 'A':
 393                         conf.tcp_keepalive = atoi(optarg);
 394                         break;
 395
 396                 case 'f':
 397                         nofork = 1;
 398                         break;
 399
 400                 case 'd':
 401                         optarg = strdup(optarg);
 402                         port = alloca(strlen(optarg) + 1);
 403                         if (!port)
 404                                 return -1;
 405
 406                         /* "decode" plus to space to retain compat */
 407                         for (opt = 0; optarg[opt]; opt++)
 408                                 if (optarg[opt] == '+')
 409                                         optarg[opt] = ' ';
 410
 411                         /* opt now contains strlen(optarg) -- no need to re-scan */
 412                         if (uh_urldecode(port, opt, optarg, opt) < 0) {
 413                                 fprintf(stderr, "uhttpd: invalid encoding\n");
 414                                 return -1;
 415                         }
 416
 417                         printf("%s", port);
 418                         return 0;
 419                         break;
 420
 421                 /* basic auth realm */
 422                 case 'r':
 423                         conf.realm = optarg;
 424                         break;
 425
 426                 /* md5 crypt */
 427                 case 'm':
 428                         printf("%s\n", crypt(optarg, "$1$"));
 429                         return 0;
 430                         break;
 431
 432                 /* config file */
 433                 case 'c':
 434                         conf.file = optarg;
 435                         break;
 436
 437 #ifdef HAVE_LUA
 438                 case 'l':
 439                 case 'L':
 440                         if (ch == 'l') {
 441                                 if (lua_prefix)
 442                                         fprintf(stderr, "uhttpd: Ignoring previous -%c %s\n",
 443                                                 ch, lua_prefix);
 444
 445                                 lua_prefix = optarg;
 446                         }
 447                         else {
 448                                 if (lua_handler)
 449                                         fprintf(stderr, "uhttpd: Ignoring previous -%c %s\n",
 450                                                 ch, lua_handler);
 451
 452                                 lua_handler = optarg;
 453                         }
 454
 455                         if (lua_prefix && lua_handler) {
 456                                 add_lua_prefix(lua_prefix, lua_handler);
 457                                 lua_prefix = NULL;
 458                                 lua_handler = NULL;
 459                         }
 460
 461                         break;
 462 #else
 463                 case 'l':
 464                 case 'L':
 465                         fprintf(stderr, "uhttpd: Lua support not compiled, "
 466                                         "ignoring -%c\n", ch);
 467                         break;
 468 #endif
 469 #ifdef HAVE_UBUS
 470                 case 'a':
 471                         conf.ubus_noauth = 1;
 472                         break;
 473
 474                 case 'u':
 475                         conf.ubus_prefix = optarg;
 476                         break;
 477
 478                 case 'U':
 479                         conf.ubus_socket = optarg;
 480                         break;
 481
 482                 case 'X':
 483                         conf.ubus_cors = 1;
 484                         break;
 485 #else
 486                 case 'a':
 487                 case 'u':
 488                 case 'U':
 489                 case 'X':
 490                         fprintf(stderr, "uhttpd: UBUS support not compiled, "
 491                                         "ignoring -%c\n", ch);
 492                         break;
 493 #endif
 494                 default:
 495                         return usage(argv[0]);
 496                 }
 497         }
 498
 499         uh_config_parse();
 500
 501         if (!conf.docroot) {
 502                 if (!realpath(".", uh_buf)) {
 503                         fprintf(stderr, "Error: Unable to determine work dir\n");
 504                         return 1;
 505                 }
 506                 conf.docroot = strdup(uh_buf);
 507         }
 508
 509         init_defaults_post();
 510
 511         if (!bound) {
 512                 fprintf(stderr, "Error: No sockets bound, unable to continue\n");
 513                 return 1;
 514         }
 515
 516 #ifdef HAVE_TLS
 517         if (n_tls) {
 518                 if (!tls_crt || !tls_key) {
 519                         fprintf(stderr, "Please specify a certificate and "
 520                                         "a key file to enable SSL support\n");
 521                         return 1;
 522                 }
 523
 524                 if (uh_tls_init(tls_key, tls_crt))
 525                     return 1;
 526         }
 527 #endif
 528
 529 #ifdef HAVE_LUA
 530         if (lua_handler || lua_prefix) {
 531                 fprintf(stderr, "Need handler and prefix to enable Lua support\n");
 532                 return 1;
 533         }
 534
 535         if (!list_empty(&conf.lua_prefix) && uh_plugin_init("uhttpd_lua.so"))
 536                 return 1;
 537 #endif
 538 #ifdef HAVE_UBUS
 539         if (conf.ubus_prefix && uh_plugin_init("uhttpd_ubus.so"))
 540                 return 1;
 541 #endif
 542
 543         /* fork (if not disabled) */
 544         if (!nofork) {
 545                 switch (fork()) {
 546                 case -1:
 547                         perror("fork()");
 548                         exit(1);
 549
 550                 case 0:
 551                         /* daemon setup */
 552                         if (chdir("/"))
 553                                 perror("chdir()");
 554
 555                         cur_fd = open("/dev/null", O_WRONLY);
 556                         if (cur_fd > 0) {
 557                                 dup2(cur_fd, 0);
 558                                 dup2(cur_fd, 1);
 559                                 dup2(cur_fd, 2);
 560                         }
 561
 562                         break;
 563
 564                 default:
 565                         exit(0);
 566                 }
 567         }
 568
 569         return run_server();
 570 }