main.c

   1 /*
   2  * uhttpd - Tiny single-threaded httpd
   3  *
   4  *   Copyright (C) 2010-2012 Jo-Philipp Wich <xm@subsignal.org>
   5  *   Copyright (C) 2012 Felix Fietkau <nbd@openwrt.org>
   6  *
   7  *  Licensed under the Apache License, Version 2.0 (the "License");
   8  *  you may not use this file except in compliance with the License.
   9  *  You may obtain a copy of the License at
  10  *
  11  *      http://www.apache.org/licenses/LICENSE-2.0
  12  *
  13  *  Unless required by applicable law or agreed to in writing, software
  14  *  distributed under the License is distributed on an "AS IS" BASIS,
  15  *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  16  *  See the License for the specific language governing permissions and
  17  *  limitations under the License.
  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         uloop_run();
  44
  45         return 0;
  46 }
  47
  48 static void uh_config_parse(void)
  49 {
  50         const char *path = conf.file;
  51         FILE *c;
  52         char line[512];
  53         char *col1;
  54         char *col2;
  55         char *eol;
  56
  57         if (!path)
  58                 path = "/etc/httpd.conf";
  59
  60         c = fopen(path, "r");
  61         if (!c)
  62                 return;
  63
  64         memset(line, 0, sizeof(line));
  65
  66         while (fgets(line, sizeof(line) - 1, c)) {
  67                 if ((line[0] == '/') && (strchr(line, ':') != NULL)) {
  68                         if (!(col1 = strchr(line, ':')) || (*col1++ = 0) ||
  69                                 !(col2 = strchr(col1, ':')) || (*col2++ = 0) ||
  70                                 !(eol = strchr(col2, '\n')) || (*eol++  = 0))
  71                                 continue;
  72
  73                         uh_auth_add(line, col1, col2);
  74                 } else if (!strncmp(line, "I:", 2)) {
  75                         if (!(col1 = strchr(line, ':')) || (*col1++ = 0) ||
  76                                 !(eol = strchr(col1, '\n')) || (*eol++  = 0))
  77                                 continue;
  78
  79                         uh_index_add(strdup(col1));
  80                 } else if (!strncmp(line, "E404:", 5)) {
  81                         if (!(col1 = strchr(line, ':')) || (*col1++ = 0) ||
  82                                 !(eol = strchr(col1, '\n')) || (*eol++  = 0))
  83                                 continue;
  84
  85                         conf.error_handler = strdup(col1);
  86                 }
  87                 else if ((line[0] == '*') && (strchr(line, ':') != NULL)) {
  88                         if (!(col1 = strchr(line, '*')) || (*col1++ = 0) ||
  89                                 !(col2 = strchr(col1, ':')) || (*col2++ = 0) ||
  90                                 !(eol = strchr(col2, '\n')) || (*eol++  = 0))
  91                                 continue;
  92
  93                         uh_interpreter_add(col1, col2);
  94                 }
  95         }
  96
  97         fclose(c);
  98 }
  99
 100 static int add_listener_arg(char *arg, bool tls)
 101 {
 102         char *host = NULL;
 103         char *port = arg;
 104         char *s;
 105
 106         s = strrchr(arg, ':');
 107         if (s) {
 108                 host = arg;
 109                 port = s + 1;
 110                 *s = 0;
 111         }
 112
 113         return uh_socket_bind(host, port, tls);
 114 }
 115
 116 static int usage(const char *name)
 117 {
 118         fprintf(stderr,
 119                 "Usage: %s -p [addr:]port -h docroot\n"
 120                 "       -f              Do not fork to background\n"
 121                 "       -c file         Configuration file, default is '/etc/httpd.conf'\n"
 122                 "       -p [addr:]port  Bind to specified address and port, multiple allowed\n"
 123 #ifdef HAVE_TLS
 124                 "       -s [addr:]port  Like -p but provide HTTPS on this port\n"
 125                 "       -C file         ASN.1 server certificate file\n"
 126                 "       -K file         ASN.1 server private key file\n"
 127 #endif
 128                 "       -h directory    Specify the document root, default is '.'\n"
 129                 "       -E string       Use given virtual URL as 404 error handler\n"
 130                 "       -I string       Use given filename as index for directories, multiple allowed\n"
 131                 "       -S              Do not follow symbolic links outside of the docroot\n"
 132                 "       -D              Do not allow directory listings, send 403 instead\n"
 133                 "       -R              Enable RFC1918 filter\n"
 134                 "       -n count        Maximum allowed number of concurrent requests\n"
 135 #ifdef HAVE_LUA
 136                 "       -l string       URL prefix for Lua handler, default is '/lua'\n"
 137                 "       -L file         Lua handler script, omit to disable Lua\n"
 138 #endif
 139 #ifdef HAVE_UBUS
 140                 "       -u string       URL prefix for HTTP/JSON handler\n"
 141                 "       -U file         Override ubus socket path\n"
 142 #endif
 143                 "       -x string       URL prefix for CGI handler, default is '/cgi-bin'\n"
 144                 "       -i .ext=path    Use interpreter at path for files with the given extension\n"
 145                 "       -t seconds      CGI, Lua and UBUS script timeout in seconds, default is 60\n"
 146                 "       -T seconds      Network timeout in seconds, default is 30\n"
 147                 "       -d string       URL decode given string\n"
 148                 "       -r string       Specify basic auth realm\n"
 149                 "       -m string       MD5 crypt given string\n"
 150                 "\n", name
 151         );
 152         return 1;
 153 }
 154
 155 static void init_defaults(void)
 156 {
 157         conf.script_timeout = 60;
 158         conf.network_timeout = 30;
 159         conf.http_keepalive = 20;
 160         conf.max_requests = 3;
 161         conf.realm = "Protected Area";
 162         conf.cgi_prefix = "/cgi-bin";
 163         conf.cgi_path = "/sbin:/usr/sbin:/bin:/usr/bin";
 164
 165         uh_index_add("index.html");
 166         uh_index_add("index.htm");
 167         uh_index_add("default.html");
 168         uh_index_add("default.htm");
 169 }
 170
 171 static void fixup_prefix(char *str)
 172 {
 173         int len;
 174
 175         if (!str || !str[0])
 176                 return;
 177
 178         len = strlen(str) - 1;
 179
 180         while (len > 0 && str[len] == '/')
 181                 len--;
 182
 183         str[len + 1] = 0;
 184 }
 185
 186 int main(int argc, char **argv)
 187 {
 188         const char *tls_key = NULL, *tls_crt = NULL;
 189         bool nofork = false;
 190         char *port;
 191         int opt, ch;
 192         int cur_fd;
 193         int bound = 0;
 194         int n_tls = 0;
 195
 196         BUILD_BUG_ON(sizeof(uh_buf) < PATH_MAX);
 197
 198         uh_dispatch_add(&cgi_dispatch);
 199         init_defaults();
 200         signal(SIGPIPE, SIG_IGN);
 201
 202         while ((ch = getopt(argc, argv, "fSDRC:K:E:I:p:s:h:c:l:L:d:r:m:n:x:i:t:T:A:u:U:")) != -1) {
 203                 bool tls = false;
 204
 205                 switch(ch) {
 206                 case 's':
 207                         n_tls++;
 208                         tls = true;
 209                         /* fall through */
 210                 case 'p':
 211                         bound += add_listener_arg(optarg, tls);
 212                         break;
 213
 214                 case 'h':
 215                         if (!realpath(optarg, uh_buf)) {
 216                                 fprintf(stderr, "Error: Invalid directory %s: %s\n",
 217                                                 optarg, strerror(errno));
 218                                 exit(1);
 219                         }
 220                         conf.docroot = strdup(uh_buf);
 221                         break;
 222
 223                 case 'E':
 224                         if (optarg[0] != '/') {
 225                                 fprintf(stderr, "Error: Invalid error handler: %s\n",
 226                                                 optarg);
 227                                 exit(1);
 228                         }
 229                         conf.error_handler = optarg;
 230                         break;
 231
 232                 case 'I':
 233                         if (optarg[0] == '/') {
 234                                 fprintf(stderr, "Error: Invalid index page: %s\n",
 235                                                 optarg);
 236                                 exit(1);
 237                         }
 238                         uh_index_add(optarg);
 239                         break;
 240
 241                 case 'S':
 242                         conf.no_symlinks = 1;
 243                         break;
 244
 245                 case 'D':
 246                         conf.no_dirlists = 1;
 247                         break;
 248
 249                 case 'R':
 250                         conf.rfc1918_filter = 1;
 251                         break;
 252
 253                 case 'n':
 254                         conf.max_requests = atoi(optarg);
 255                         break;
 256
 257                 case 'x':
 258                         fixup_prefix(optarg);
 259                         conf.cgi_prefix = optarg;
 260                         break;
 261
 262                 case 'i':
 263                         port = strchr(optarg, '=');
 264                         if (optarg[0] != '.' || !port) {
 265                                 fprintf(stderr, "Error: Invalid interpreter: %s\n",
 266                                                 optarg);
 267                                 exit(1);
 268                         }
 269
 270                         *port++ = 0;
 271                         uh_interpreter_add(optarg, port);
 272                         break;
 273
 274                 case 't':
 275                         conf.script_timeout = atoi(optarg);
 276                         break;
 277
 278                 case 'T':
 279                         conf.network_timeout = atoi(optarg);
 280                         break;
 281
 282                 case 'A':
 283                         conf.tcp_keepalive = atoi(optarg);
 284                         break;
 285
 286                 case 'f':
 287                         nofork = 1;
 288                         break;
 289
 290                 case 'd':
 291                         port = alloca(strlen(optarg) + 1);
 292                         if (!port)
 293                                 return -1;
 294
 295                         /* "decode" plus to space to retain compat */
 296                         for (opt = 0; optarg[opt]; opt++)
 297                                 if (optarg[opt] == '+')
 298                                         optarg[opt] = ' ';
 299
 300                         /* opt now contains strlen(optarg) -- no need to re-scan */
 301                         if (uh_urldecode(port, opt, optarg, opt) < 0) {
 302                                 fprintf(stderr, "uhttpd: invalid encoding\n");
 303                                 return -1;
 304                         }
 305
 306                         printf("%s", port);
 307                         break;
 308
 309                 /* basic auth realm */
 310                 case 'r':
 311                         conf.realm = optarg;
 312                         break;
 313
 314                 /* md5 crypt */
 315                 case 'm':
 316                         printf("%s\n", crypt(optarg, "$1$"));
 317                         return 0;
 318                         break;
 319
 320                 /* config file */
 321                 case 'c':
 322                         conf.file = optarg;
 323                         break;
 324
 325                 case 'C':
 326                         tls_crt = optarg;
 327                         break;
 328
 329                 case 'K':
 330                         tls_key = optarg;
 331                         break;
 332 #ifdef HAVE_LUA
 333                 case 'l':
 334                         conf.lua_prefix = optarg;
 335                         break;
 336
 337                 case 'L':
 338                         conf.lua_handler = optarg;
 339                         break;
 340 #endif
 341                 default:
 342                         return usage(argv[0]);
 343                 }
 344         }
 345
 346         uh_config_parse();
 347
 348         if (!bound) {
 349                 fprintf(stderr, "Error: No sockets bound, unable to continue\n");
 350                 return 1;
 351         }
 352
 353         if (n_tls) {
 354                 if (!tls_crt || !tls_key) {
 355                         fprintf(stderr, "Please specify a certificate and "
 356                                         "a key file to enable SSL support\n");
 357                         return 1;
 358                 }
 359
 360 #ifdef HAVE_TLS
 361                 if (uh_tls_init(tls_key, tls_crt))
 362                     return 1;
 363 #else
 364                 fprintf(stderr, "Error: TLS support not compiled in.\n");
 365                 return 1;
 366 #endif
 367         }
 368
 369 #ifdef HAVE_LUA
 370         if (conf.lua_handler || conf.lua_prefix) {
 371                 if (!conf.lua_handler || !conf.lua_prefix) {
 372                         fprintf(stderr, "Need handler and prefix to enable Lua support\n");
 373                         return 1;
 374                 }
 375                 if (uh_plugin_init("uhttpd_lua.so"))
 376                         return 1;
 377         }
 378 #endif
 379
 380         /* fork (if not disabled) */
 381         if (!nofork) {
 382                 switch (fork()) {
 383                 case -1:
 384                         perror("fork()");
 385                         exit(1);
 386
 387                 case 0:
 388                         /* daemon setup */
 389                         if (chdir("/"))
 390                                 perror("chdir()");
 391
 392                         cur_fd = open("/dev/null", O_WRONLY);
 393                         if (cur_fd > 0) {
 394                                 dup2(cur_fd, 0);
 395                                 dup2(cur_fd, 1);
 396                                 dup2(cur_fd, 2);
 397                         }
 398
 399                         break;
 400
 401                 default:
 402                         exit(0);
 403                 }
 404         }
 405
 406         return run_server();
 407 }