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
 107         s = strrchr(arg, ':');
 108         if (s) {
 109                 host = arg;
 110                 port = s + 1;
 111                 *s = 0;
 112         }
 113
 114         return uh_socket_bind(host, port, tls);
 115 }
 116
 117 static int usage(const char *name)
 118 {
 119         fprintf(stderr,
 120                 "Usage: %s -p [addr:]port -h docroot\n"
 121                 "       -f              Do not fork to background\n"
 122                 "       -c file         Configuration file, default is '/etc/httpd.conf'\n"
 123                 "       -p [addr:]port  Bind to specified address and port, multiple allowed\n"
 124 #ifdef HAVE_TLS
 125                 "       -s [addr:]port  Like -p but provide HTTPS on this port\n"
 126                 "       -C file         ASN.1 server certificate file\n"
 127                 "       -K file         ASN.1 server private key file\n"
 128 #endif
 129                 "       -h directory    Specify the document root, default is '.'\n"
 130                 "       -E string       Use given virtual URL as 404 error handler\n"
 131                 "       -I string       Use given filename as index for directories, multiple allowed\n"
 132                 "       -S              Do not follow symbolic links outside of the docroot\n"
 133                 "       -D              Do not allow directory listings, send 403 instead\n"
 134                 "       -R              Enable RFC1918 filter\n"
 135                 "       -n count        Maximum allowed number of concurrent script requests\n"
 136                 "       -N count        Maximum allowed number of concurrent connections\n"
 137 #ifdef HAVE_LUA
 138                 "       -l string       URL prefix for Lua handler, default is '/lua'\n"
 139                 "       -L file         Lua handler script, omit to disable Lua\n"
 140 #endif
 141 #ifdef HAVE_UBUS
 142                 "       -u string       URL prefix for UBUS via JSON-RPC handler\n"
 143                 "       -U file         Override ubus socket path\n"
 144                 "       -a              Do not authenticate JSON-RPC requests against UBUS session api\n"
 145 #endif
 146                 "       -x string       URL prefix for CGI handler, default is '/cgi-bin'\n"
 147                 "       -i .ext=path    Use interpreter at path for files with the given extension\n"
 148                 "       -t seconds      CGI, Lua and UBUS script timeout in seconds, default is 60\n"
 149                 "       -T seconds      Network timeout in seconds, default is 30\n"
 150                 "       -k seconds      HTTP keepalive timeout\n"
 151                 "       -d string       URL decode given string\n"
 152                 "       -r string       Specify basic auth realm\n"
 153                 "       -m string       MD5 crypt given string\n"
 154                 "\n", name
 155         );
 156         return 1;
 157 }
 158
 159 static void init_defaults(void)
 160 {
 161         conf.script_timeout = 60;
 162         conf.network_timeout = 30;
 163         conf.http_keepalive = 20;
 164         conf.max_script_requests = 3;
 165         conf.max_connections = 100;
 166         conf.realm = "Protected Area";
 167         conf.cgi_prefix = "/cgi-bin";
 168         conf.cgi_path = "/sbin:/usr/sbin:/bin:/usr/bin";
 169
 170         uh_index_add("index.html");
 171         uh_index_add("index.htm");
 172         uh_index_add("default.html");
 173         uh_index_add("default.htm");
 174 }
 175
 176 static void fixup_prefix(char *str)
 177 {
 178         int len;
 179
 180         if (!str || !str[0])
 181                 return;
 182
 183         len = strlen(str) - 1;
 184
 185         while (len > 0 && str[len] == '/')
 186                 len--;
 187
 188         str[len + 1] = 0;
 189 }
 190
 191 int main(int argc, char **argv)
 192 {
 193         bool nofork = false;
 194         char *port;
 195         int opt, ch;
 196         int cur_fd;
 197         int bound = 0;
 198
 199 #ifdef HAVE_TLS
 200         int n_tls = 0;
 201         const char *tls_key = NULL, *tls_crt = NULL;
 202 #endif
 203
 204         BUILD_BUG_ON(sizeof(uh_buf) < PATH_MAX);
 205
 206         uh_dispatch_add(&cgi_dispatch);
 207         init_defaults();
 208         signal(SIGPIPE, SIG_IGN);
 209
 210         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) {
 211                 switch(ch) {
 212 #ifdef HAVE_TLS
 213                 case 'C':
 214                         tls_crt = optarg;
 215                         break;
 216
 217                 case 'K':
 218                         tls_key = optarg;
 219                         break;
 220
 221                 case 's':
 222                         n_tls++;
 223                         /* fall through */
 224 #else
 225                 case 'C':
 226                 case 'K':
 227                 case 's':
 228                         fprintf(stderr, "uhttpd: TLS support not compiled, "
 229                                         "ignoring -%c\n", opt);
 230                         break;
 231 #endif
 232                 case 'p':
 233                         bound += add_listener_arg(optarg, (ch == 's'));
 234                         break;
 235
 236                 case 'h':
 237                         if (!realpath(optarg, uh_buf)) {
 238                                 fprintf(stderr, "Error: Invalid directory %s: %s\n",
 239                                                 optarg, strerror(errno));
 240                                 exit(1);
 241                         }
 242                         conf.docroot = strdup(uh_buf);
 243                         break;
 244
 245                 case 'E':
 246                         if (optarg[0] != '/') {
 247                                 fprintf(stderr, "Error: Invalid error handler: %s\n",
 248                                                 optarg);
 249                                 exit(1);
 250                         }
 251                         conf.error_handler = optarg;
 252                         break;
 253
 254                 case 'I':
 255                         if (optarg[0] == '/') {
 256                                 fprintf(stderr, "Error: Invalid index page: %s\n",
 257                                                 optarg);
 258                                 exit(1);
 259                         }
 260                         uh_index_add(optarg);
 261                         break;
 262
 263                 case 'S':
 264                         conf.no_symlinks = 1;
 265                         break;
 266
 267                 case 'D':
 268                         conf.no_dirlists = 1;
 269                         break;
 270
 271                 case 'R':
 272                         conf.rfc1918_filter = 1;
 273                         break;
 274
 275                 case 'n':
 276                         conf.max_script_requests = atoi(optarg);
 277                         break;
 278
 279                 case 'N':
 280                         conf.max_connections = atoi(optarg);
 281                         break;
 282
 283                 case 'x':
 284                         fixup_prefix(optarg);
 285                         conf.cgi_prefix = optarg;
 286                         break;
 287
 288                 case 'i':
 289                         port = strchr(optarg, '=');
 290                         if (optarg[0] != '.' || !port) {
 291                                 fprintf(stderr, "Error: Invalid interpreter: %s\n",
 292                                                 optarg);
 293                                 exit(1);
 294                         }
 295
 296                         *port++ = 0;
 297                         uh_interpreter_add(optarg, port);
 298                         break;
 299
 300                 case 't':
 301                         conf.script_timeout = atoi(optarg);
 302                         break;
 303
 304                 case 'T':
 305                         conf.network_timeout = atoi(optarg);
 306                         break;
 307
 308                 case 'k':
 309                         conf.http_keepalive = atoi(optarg);
 310                         break;
 311
 312                 case 'A':
 313                         conf.tcp_keepalive = atoi(optarg);
 314                         break;
 315
 316                 case 'f':
 317                         nofork = 1;
 318                         break;
 319
 320                 case 'd':
 321                         port = alloca(strlen(optarg) + 1);
 322                         if (!port)
 323                                 return -1;
 324
 325                         /* "decode" plus to space to retain compat */
 326                         for (opt = 0; optarg[opt]; opt++)
 327                                 if (optarg[opt] == '+')
 328                                         optarg[opt] = ' ';
 329
 330                         /* opt now contains strlen(optarg) -- no need to re-scan */
 331                         if (uh_urldecode(port, opt, optarg, opt) < 0) {
 332                                 fprintf(stderr, "uhttpd: invalid encoding\n");
 333                                 return -1;
 334                         }
 335
 336                         printf("%s", port);
 337                         break;
 338
 339                 /* basic auth realm */
 340                 case 'r':
 341                         conf.realm = optarg;
 342                         break;
 343
 344                 /* md5 crypt */
 345                 case 'm':
 346                         printf("%s\n", crypt(optarg, "$1$"));
 347                         return 0;
 348                         break;
 349
 350                 /* config file */
 351                 case 'c':
 352                         conf.file = optarg;
 353                         break;
 354
 355 #ifdef HAVE_LUA
 356                 case 'l':
 357                         conf.lua_prefix = optarg;
 358                         break;
 359
 360                 case 'L':
 361                         conf.lua_handler = optarg;
 362                         break;
 363 #else
 364                 case 'l':
 365                 case 'L':
 366                         fprintf(stderr, "uhttpd: Lua support not compiled, "
 367                                         "ignoring -%c\n", opt);
 368                         break;
 369 #endif
 370 #ifdef HAVE_UBUS
 371                 case 'a':
 372                         conf.ubus_noauth = 1;
 373                         break;
 374
 375                 case 'u':
 376                         conf.ubus_prefix = optarg;
 377                         break;
 378
 379                 case 'U':
 380                         conf.ubus_socket = optarg;
 381                         break;
 382 #else
 383                 case 'a':
 384                 case 'u':
 385                 case 'U':
 386                         fprintf(stderr, "uhttpd: UBUS support not compiled, "
 387                                         "ignoring -%c\n", opt);
 388                         break;
 389 #endif
 390                 default:
 391                         return usage(argv[0]);
 392                 }
 393         }
 394
 395         uh_config_parse();
 396
 397         if (!bound) {
 398                 fprintf(stderr, "Error: No sockets bound, unable to continue\n");
 399                 return 1;
 400         }
 401
 402         if (!conf.docroot) {
 403                 if (!realpath(".", uh_buf)) {
 404                         fprintf(stderr, "Error: Unable to determine work dir\n");
 405                         return 1;
 406                 }
 407                 conf.docroot = strdup(uh_buf);
 408         }
 409
 410 #ifdef HAVE_TLS
 411         if (n_tls) {
 412                 if (!tls_crt || !tls_key) {
 413                         fprintf(stderr, "Please specify a certificate and "
 414                                         "a key file to enable SSL support\n");
 415                         return 1;
 416                 }
 417
 418                 if (uh_tls_init(tls_key, tls_crt))
 419                     return 1;
 420         }
 421 #endif
 422
 423 #ifdef HAVE_LUA
 424         if (conf.lua_handler || conf.lua_prefix) {
 425                 if (!conf.lua_handler || !conf.lua_prefix) {
 426                         fprintf(stderr, "Need handler and prefix to enable Lua support\n");
 427                         return 1;
 428                 }
 429                 if (uh_plugin_init("uhttpd_lua.so"))
 430                         return 1;
 431         }
 432 #endif
 433 #ifdef HAVE_UBUS
 434         if (conf.ubus_prefix && uh_plugin_init("uhttpd_ubus.so"))
 435                 return 1;
 436 #endif
 437
 438         /* fork (if not disabled) */
 439         if (!nofork) {
 440                 switch (fork()) {
 441                 case -1:
 442                         perror("fork()");
 443                         exit(1);
 444
 445                 case 0:
 446                         /* daemon setup */
 447                         if (chdir("/"))
 448                                 perror("chdir()");
 449
 450                         cur_fd = open("/dev/null", O_WRONLY);
 451                         if (cur_fd > 0) {
 452                                 dup2(cur_fd, 0);
 453                                 dup2(cur_fd, 1);
 454                                 dup2(cur_fd, 2);
 455                         }
 456
 457                         break;
 458
 459                 default:
 460                         exit(0);
 461                 }
 462         }
 463
 464         return run_server();
 465 }