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 #endif
 138                 "       -h directory    Specify the document root, default is '.'\n"
 139                 "       -E string       Use given virtual URL as 404 error handler\n"
 140                 "       -I string       Use given filename as index for directories, multiple allowed\n"
 141                 "       -S              Do not follow symbolic links outside of the docroot\n"
 142                 "       -D              Do not allow directory listings, send 403 instead\n"
 143                 "       -R              Enable RFC1918 filter\n"
 144                 "       -n count        Maximum allowed number of concurrent script requests\n"
 145                 "       -N count        Maximum allowed number of concurrent connections\n"
 146 #ifdef HAVE_LUA
 147                 "       -l string       URL prefix for Lua handler, default is '/lua'\n"
 148                 "       -L file         Lua handler script, omit to disable Lua\n"
 149 #endif
 150 #ifdef HAVE_UBUS
 151                 "       -u string       URL prefix for UBUS via JSON-RPC handler\n"
 152                 "       -U file         Override ubus socket path\n"
 153                 "       -a              Do not authenticate JSON-RPC requests against UBUS session api\n"
 154 #endif
 155                 "       -x string       URL prefix for CGI handler, default is '/cgi-bin'\n"
 156                 "       -i .ext=path    Use interpreter at path for files with the given extension\n"
 157                 "       -t seconds      CGI, Lua and UBUS script timeout in seconds, default is 60\n"
 158                 "       -T seconds      Network timeout in seconds, default is 30\n"
 159                 "       -k seconds      HTTP keepalive timeout\n"
 160                 "       -d string       URL decode given string\n"
 161                 "       -r string       Specify basic auth realm\n"
 162                 "       -m string       MD5 crypt given string\n"
 163                 "\n", name
 164         );
 165         return 1;
 166 }
 167
 168 static void init_defaults_pre(void)
 169 {
 170         conf.script_timeout = 60;
 171         conf.network_timeout = 30;
 172         conf.http_keepalive = 20;
 173         conf.max_script_requests = 3;
 174         conf.max_connections = 100;
 175         conf.realm = "Protected Area";
 176         conf.cgi_prefix = "/cgi-bin";
 177         conf.cgi_path = "/sbin:/usr/sbin:/bin:/usr/bin";
 178 }
 179
 180 static void init_defaults_post(void)
 181 {
 182         uh_index_add("index.html");
 183         uh_index_add("index.htm");
 184         uh_index_add("default.html");
 185         uh_index_add("default.htm");
 186 }
 187
 188 static void fixup_prefix(char *str)
 189 {
 190         int len;
 191
 192         if (!str || !str[0])
 193                 return;
 194
 195         len = strlen(str) - 1;
 196
 197         while (len > 0 && str[len] == '/')
 198                 len--;
 199
 200         str[len + 1] = 0;
 201 }
 202
 203 int main(int argc, char **argv)
 204 {
 205         bool nofork = false;
 206         char *port;
 207         int opt, ch;
 208         int cur_fd;
 209         int bound = 0;
 210
 211 #ifdef HAVE_TLS
 212         int n_tls = 0;
 213         const char *tls_key = NULL, *tls_crt = NULL;
 214 #endif
 215
 216         BUILD_BUG_ON(sizeof(uh_buf) < PATH_MAX);
 217
 218         uh_dispatch_add(&cgi_dispatch);
 219         init_defaults_pre();
 220         signal(SIGPIPE, SIG_IGN);
 221
 222         while ((ch = getopt(argc, argv, "afSDRC:K:E:I:p:s:h:c:l:L:d:r:m:n:N:x:i:t:k:T:A:u:U:")) != -1) {
 223                 switch(ch) {
 224 #ifdef HAVE_TLS
 225                 case 'C':
 226                         tls_crt = optarg;
 227                         break;
 228
 229                 case 'K':
 230                         tls_key = optarg;
 231                         break;
 232
 233                 case 's':
 234                         n_tls++;
 235                         /* fall through */
 236 #else
 237                 case 'C':
 238                 case 'K':
 239                 case 's':
 240                         fprintf(stderr, "uhttpd: TLS support not compiled, "
 241                                         "ignoring -%c\n", opt);
 242                         break;
 243 #endif
 244                 case 'p':
 245                         bound += add_listener_arg(optarg, (ch == 's'));
 246                         break;
 247
 248                 case 'h':
 249                         if (!realpath(optarg, uh_buf)) {
 250                                 fprintf(stderr, "Error: Invalid directory %s: %s\n",
 251                                                 optarg, strerror(errno));
 252                                 exit(1);
 253                         }
 254                         conf.docroot = strdup(uh_buf);
 255                         break;
 256
 257                 case 'E':
 258                         if (optarg[0] != '/') {
 259                                 fprintf(stderr, "Error: Invalid error handler: %s\n",
 260                                                 optarg);
 261                                 exit(1);
 262                         }
 263                         conf.error_handler = optarg;
 264                         break;
 265
 266                 case 'I':
 267                         if (optarg[0] == '/') {
 268                                 fprintf(stderr, "Error: Invalid index page: %s\n",
 269                                                 optarg);
 270                                 exit(1);
 271                         }
 272                         uh_index_add(optarg);
 273                         break;
 274
 275                 case 'S':
 276                         conf.no_symlinks = 1;
 277                         break;
 278
 279                 case 'D':
 280                         conf.no_dirlists = 1;
 281                         break;
 282
 283                 case 'R':
 284                         conf.rfc1918_filter = 1;
 285                         break;
 286
 287                 case 'n':
 288                         conf.max_script_requests = atoi(optarg);
 289                         break;
 290
 291                 case 'N':
 292                         conf.max_connections = atoi(optarg);
 293                         break;
 294
 295                 case 'x':
 296                         fixup_prefix(optarg);
 297                         conf.cgi_prefix = optarg;
 298                         break;
 299
 300                 case 'i':
 301                         port = strchr(optarg, '=');
 302                         if (optarg[0] != '.' || !port) {
 303                                 fprintf(stderr, "Error: Invalid interpreter: %s\n",
 304                                                 optarg);
 305                                 exit(1);
 306                         }
 307
 308                         *port++ = 0;
 309                         uh_interpreter_add(optarg, port);
 310                         break;
 311
 312                 case 't':
 313                         conf.script_timeout = atoi(optarg);
 314                         break;
 315
 316                 case 'T':
 317                         conf.network_timeout = atoi(optarg);
 318                         break;
 319
 320                 case 'k':
 321                         conf.http_keepalive = atoi(optarg);
 322                         break;
 323
 324                 case 'A':
 325                         conf.tcp_keepalive = atoi(optarg);
 326                         break;
 327
 328                 case 'f':
 329                         nofork = 1;
 330                         break;
 331
 332                 case 'd':
 333                         port = alloca(strlen(optarg) + 1);
 334                         if (!port)
 335                                 return -1;
 336
 337                         /* "decode" plus to space to retain compat */
 338                         for (opt = 0; optarg[opt]; opt++)
 339                                 if (optarg[opt] == '+')
 340                                         optarg[opt] = ' ';
 341
 342                         /* opt now contains strlen(optarg) -- no need to re-scan */
 343                         if (uh_urldecode(port, opt, optarg, opt) < 0) {
 344                                 fprintf(stderr, "uhttpd: invalid encoding\n");
 345                                 return -1;
 346                         }
 347
 348                         printf("%s", port);
 349                         return 0;
 350                         break;
 351
 352                 /* basic auth realm */
 353                 case 'r':
 354                         conf.realm = optarg;
 355                         break;
 356
 357                 /* md5 crypt */
 358                 case 'm':
 359                         printf("%s\n", crypt(optarg, "$1$"));
 360                         return 0;
 361                         break;
 362
 363                 /* config file */
 364                 case 'c':
 365                         conf.file = optarg;
 366                         break;
 367
 368 #ifdef HAVE_LUA
 369                 case 'l':
 370                         conf.lua_prefix = optarg;
 371                         break;
 372
 373                 case 'L':
 374                         conf.lua_handler = optarg;
 375                         break;
 376 #else
 377                 case 'l':
 378                 case 'L':
 379                         fprintf(stderr, "uhttpd: Lua support not compiled, "
 380                                         "ignoring -%c\n", opt);
 381                         break;
 382 #endif
 383 #ifdef HAVE_UBUS
 384                 case 'a':
 385                         conf.ubus_noauth = 1;
 386                         break;
 387
 388                 case 'u':
 389                         conf.ubus_prefix = optarg;
 390                         break;
 391
 392                 case 'U':
 393                         conf.ubus_socket = optarg;
 394                         break;
 395 #else
 396                 case 'a':
 397                 case 'u':
 398                 case 'U':
 399                         fprintf(stderr, "uhttpd: UBUS support not compiled, "
 400                                         "ignoring -%c\n", opt);
 401                         break;
 402 #endif
 403                 default:
 404                         return usage(argv[0]);
 405                 }
 406         }
 407
 408         uh_config_parse();
 409         init_defaults_post();
 410
 411         if (!bound) {
 412                 fprintf(stderr, "Error: No sockets bound, unable to continue\n");
 413                 return 1;
 414         }
 415
 416         if (!conf.docroot) {
 417                 if (!realpath(".", uh_buf)) {
 418                         fprintf(stderr, "Error: Unable to determine work dir\n");
 419                         return 1;
 420                 }
 421                 conf.docroot = strdup(uh_buf);
 422         }
 423
 424 #ifdef HAVE_TLS
 425         if (n_tls) {
 426                 if (!tls_crt || !tls_key) {
 427                         fprintf(stderr, "Please specify a certificate and "
 428                                         "a key file to enable SSL support\n");
 429                         return 1;
 430                 }
 431
 432                 if (uh_tls_init(tls_key, tls_crt))
 433                     return 1;
 434         }
 435 #endif
 436
 437 #ifdef HAVE_LUA
 438         if (conf.lua_handler || conf.lua_prefix) {
 439                 if (!conf.lua_handler || !conf.lua_prefix) {
 440                         fprintf(stderr, "Need handler and prefix to enable Lua support\n");
 441                         return 1;
 442                 }
 443                 if (uh_plugin_init("uhttpd_lua.so"))
 444                         return 1;
 445         }
 446 #endif
 447 #ifdef HAVE_UBUS
 448         if (conf.ubus_prefix && uh_plugin_init("uhttpd_ubus.so"))
 449                 return 1;
 450 #endif
 451
 452         /* fork (if not disabled) */
 453         if (!nofork) {
 454                 switch (fork()) {
 455                 case -1:
 456                         perror("fork()");
 457                         exit(1);
 458
 459                 case 0:
 460                         /* daemon setup */
 461                         if (chdir("/"))
 462                                 perror("chdir()");
 463
 464                         cur_fd = open("/dev/null", O_WRONLY);
 465                         if (cur_fd > 0) {
 466                                 dup2(cur_fd, 0);
 467                                 dup2(cur_fd, 1);
 468                                 dup2(cur_fd, 2);
 469                         }
 470
 471                         break;
 472
 473                 default:
 474                         exit(0);
 475                 }
 476         }
 477
 478         return run_server();
 479 }