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                 "       -i .ext=path    Use interpreter at path for files with the given extension\n"
 159                 "       -t seconds      CGI, Lua and UBUS script timeout in seconds, default is 60\n"
 160                 "       -T seconds      Network timeout in seconds, default is 30\n"
 161                 "       -k seconds      HTTP keepalive timeout\n"
 162                 "       -d string       URL decode given string\n"
 163                 "       -r string       Specify basic auth realm\n"
 164                 "       -m string       MD5 crypt given string\n"
 165                 "\n", name
 166         );
 167         return 1;
 168 }
 169
 170 static void init_defaults_pre(void)
 171 {
 172         conf.script_timeout = 60;
 173         conf.network_timeout = 30;
 174         conf.http_keepalive = 20;
 175         conf.max_script_requests = 3;
 176         conf.max_connections = 100;
 177         conf.realm = "Protected Area";
 178         conf.cgi_prefix = "/cgi-bin";
 179         conf.cgi_path = "/sbin:/usr/sbin:/bin:/usr/bin";
 180 }
 181
 182 static void init_defaults_post(void)
 183 {
 184         uh_index_add("index.html");
 185         uh_index_add("index.htm");
 186         uh_index_add("default.html");
 187         uh_index_add("default.htm");
 188
 189         if (conf.cgi_prefix) {
 190                 char *str = malloc(strlen(conf.docroot) + strlen(conf.cgi_prefix) + 1);
 191                 strcpy(str, conf.docroot);
 192                 strcat(str, conf.cgi_prefix);
 193                 conf.cgi_docroot_path = str;
 194         };
 195 }
 196
 197 static void fixup_prefix(char *str)
 198 {
 199         int len;
 200
 201         if (!str || !str[0])
 202                 return;
 203
 204         len = strlen(str) - 1;
 205
 206         while (len >= 0 && str[len] == '/')
 207                 len--;
 208
 209         str[len + 1] = 0;
 210 }
 211
 212 int main(int argc, char **argv)
 213 {
 214         bool nofork = false;
 215         char *port;
 216         int opt, ch;
 217         int cur_fd;
 218         int bound = 0;
 219
 220 #ifdef HAVE_TLS
 221         int n_tls = 0;
 222         const char *tls_key = NULL, *tls_crt = NULL;
 223 #endif
 224
 225         BUILD_BUG_ON(sizeof(uh_buf) < PATH_MAX);
 226
 227         uh_dispatch_add(&cgi_dispatch);
 228         init_defaults_pre();
 229         signal(SIGPIPE, SIG_IGN);
 230
 231         while ((ch = getopt(argc, argv, "afqSDRXC:K:E:I:p:s:h:c:l:L:d:r:m:n:N:x:i:t:k:T:A:u:U:")) != -1) {
 232                 switch(ch) {
 233 #ifdef HAVE_TLS
 234                 case 'C':
 235                         tls_crt = optarg;
 236                         break;
 237
 238                 case 'K':
 239                         tls_key = optarg;
 240                         break;
 241
 242                 case 'q':
 243                         conf.tls_redirect = 1;
 244                         break;
 245
 246                 case 's':
 247                         n_tls++;
 248                         /* fall through */
 249 #else
 250                 case 'C':
 251                 case 'K':
 252                 case 'q':
 253                 case 's':
 254                         fprintf(stderr, "uhttpd: TLS support not compiled, "
 255                                         "ignoring -%c\n", ch);
 256                         break;
 257 #endif
 258                 case 'p':
 259                         optarg = strdup(optarg);
 260                         bound += add_listener_arg(optarg, (ch == 's'));
 261                         break;
 262
 263                 case 'h':
 264                         if (!realpath(optarg, uh_buf)) {
 265                                 fprintf(stderr, "Error: Invalid directory %s: %s\n",
 266                                                 optarg, strerror(errno));
 267                                 exit(1);
 268                         }
 269                         conf.docroot = strdup(uh_buf);
 270                         break;
 271
 272                 case 'E':
 273                         if (optarg[0] != '/') {
 274                                 fprintf(stderr, "Error: Invalid error handler: %s\n",
 275                                                 optarg);
 276                                 exit(1);
 277                         }
 278                         conf.error_handler = optarg;
 279                         break;
 280
 281                 case 'I':
 282                         if (optarg[0] == '/') {
 283                                 fprintf(stderr, "Error: Invalid index page: %s\n",
 284                                                 optarg);
 285                                 exit(1);
 286                         }
 287                         uh_index_add(optarg);
 288                         break;
 289
 290                 case 'S':
 291                         conf.no_symlinks = 1;
 292                         break;
 293
 294                 case 'D':
 295                         conf.no_dirlists = 1;
 296                         break;
 297
 298                 case 'R':
 299                         conf.rfc1918_filter = 1;
 300                         break;
 301
 302                 case 'n':
 303                         conf.max_script_requests = atoi(optarg);
 304                         break;
 305
 306                 case 'N':
 307                         conf.max_connections = atoi(optarg);
 308                         break;
 309
 310                 case 'x':
 311                         fixup_prefix(optarg);
 312                         conf.cgi_prefix = optarg;
 313                         break;
 314
 315                 case 'i':
 316                         optarg = strdup(optarg);
 317                         port = strchr(optarg, '=');
 318                         if (optarg[0] != '.' || !port) {
 319                                 fprintf(stderr, "Error: Invalid interpreter: %s\n",
 320                                                 optarg);
 321                                 exit(1);
 322                         }
 323
 324                         *port++ = 0;
 325                         uh_interpreter_add(optarg, port);
 326                         break;
 327
 328                 case 't':
 329                         conf.script_timeout = atoi(optarg);
 330                         break;
 331
 332                 case 'T':
 333                         conf.network_timeout = atoi(optarg);
 334                         break;
 335
 336                 case 'k':
 337                         conf.http_keepalive = atoi(optarg);
 338                         break;
 339
 340                 case 'A':
 341                         conf.tcp_keepalive = atoi(optarg);
 342                         break;
 343
 344                 case 'f':
 345                         nofork = 1;
 346                         break;
 347
 348                 case 'd':
 349                         optarg = strdup(optarg);
 350                         port = alloca(strlen(optarg) + 1);
 351                         if (!port)
 352                                 return -1;
 353
 354                         /* "decode" plus to space to retain compat */
 355                         for (opt = 0; optarg[opt]; opt++)
 356                                 if (optarg[opt] == '+')
 357                                         optarg[opt] = ' ';
 358
 359                         /* opt now contains strlen(optarg) -- no need to re-scan */
 360                         if (uh_urldecode(port, opt, optarg, opt) < 0) {
 361                                 fprintf(stderr, "uhttpd: invalid encoding\n");
 362                                 return -1;
 363                         }
 364
 365                         printf("%s", port);
 366                         return 0;
 367                         break;
 368
 369                 /* basic auth realm */
 370                 case 'r':
 371                         conf.realm = optarg;
 372                         break;
 373
 374                 /* md5 crypt */
 375                 case 'm':
 376                         printf("%s\n", crypt(optarg, "$1$"));
 377                         return 0;
 378                         break;
 379
 380                 /* config file */
 381                 case 'c':
 382                         conf.file = optarg;
 383                         break;
 384
 385 #ifdef HAVE_LUA
 386                 case 'l':
 387                         conf.lua_prefix = optarg;
 388                         break;
 389
 390                 case 'L':
 391                         conf.lua_handler = optarg;
 392                         break;
 393 #else
 394                 case 'l':
 395                 case 'L':
 396                         fprintf(stderr, "uhttpd: Lua support not compiled, "
 397                                         "ignoring -%c\n", ch);
 398                         break;
 399 #endif
 400 #ifdef HAVE_UBUS
 401                 case 'a':
 402                         conf.ubus_noauth = 1;
 403                         break;
 404
 405                 case 'u':
 406                         conf.ubus_prefix = optarg;
 407                         break;
 408
 409                 case 'U':
 410                         conf.ubus_socket = optarg;
 411                         break;
 412
 413                 case 'X':
 414                         conf.ubus_cors = 1;
 415                         break;
 416 #else
 417                 case 'a':
 418                 case 'u':
 419                 case 'U':
 420                 case 'X':
 421                         fprintf(stderr, "uhttpd: UBUS support not compiled, "
 422                                         "ignoring -%c\n", ch);
 423                         break;
 424 #endif
 425                 default:
 426                         return usage(argv[0]);
 427                 }
 428         }
 429
 430         uh_config_parse();
 431
 432         if (!conf.docroot) {
 433                 if (!realpath(".", uh_buf)) {
 434                         fprintf(stderr, "Error: Unable to determine work dir\n");
 435                         return 1;
 436                 }
 437                 conf.docroot = strdup(uh_buf);
 438         }
 439
 440         init_defaults_post();
 441
 442         if (!bound) {
 443                 fprintf(stderr, "Error: No sockets bound, unable to continue\n");
 444                 return 1;
 445         }
 446
 447 #ifdef HAVE_TLS
 448         if (n_tls) {
 449                 if (!tls_crt || !tls_key) {
 450                         fprintf(stderr, "Please specify a certificate and "
 451                                         "a key file to enable SSL support\n");
 452                         return 1;
 453                 }
 454
 455                 if (uh_tls_init(tls_key, tls_crt))
 456                     return 1;
 457         }
 458 #endif
 459
 460 #ifdef HAVE_LUA
 461         if (conf.lua_handler || conf.lua_prefix) {
 462                 if (!conf.lua_handler || !conf.lua_prefix) {
 463                         fprintf(stderr, "Need handler and prefix to enable Lua support\n");
 464                         return 1;
 465                 }
 466                 if (uh_plugin_init("uhttpd_lua.so"))
 467                         return 1;
 468         }
 469 #endif
 470 #ifdef HAVE_UBUS
 471         if (conf.ubus_prefix && uh_plugin_init("uhttpd_ubus.so"))
 472                 return 1;
 473 #endif
 474
 475         /* fork (if not disabled) */
 476         if (!nofork) {
 477                 switch (fork()) {
 478                 case -1:
 479                         perror("fork()");
 480                         exit(1);
 481
 482                 case 0:
 483                         /* daemon setup */
 484                         if (chdir("/"))
 485                                 perror("chdir()");
 486
 487                         cur_fd = open("/dev/null", O_WRONLY);
 488                         if (cur_fd > 0) {
 489                                 dup2(cur_fd, 0);
 490                                 dup2(cur_fd, 1);
 491                                 dup2(cur_fd, 2);
 492                         }
 493
 494                         break;
 495
 496                 default:
 497                         exit(0);
 498                 }
 499         }
 500
 501         return run_server();
 502 }