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