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