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