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 #ifdef HAVE_CGI
  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                         if (!uh_interpreter_add(col1, col2))
  95                                 fprintf(stderr,
  96                                                 "Unable to add interpreter %s for extension %s: "
  97                                                 "Out of memory\n", col2, col1
  98                                 );
  99                 }
 100 #endif
 101         }
 102
 103         fclose(c);
 104 }
 105
 106 static int add_listener_arg(char *arg, bool tls)
 107 {
 108         char *host = NULL;
 109         char *port = arg;
 110         char *s;
 111
 112         s = strrchr(arg, ':');
 113         if (s) {
 114                 host = arg;
 115                 port = s + 1;
 116                 *s = 0;
 117         }
 118
 119         return uh_socket_bind(host, port, tls);
 120 }
 121
 122 static int usage(const char *name)
 123 {
 124         fprintf(stderr,
 125                 "Usage: %s -p [addr:]port -h docroot\n"
 126                 "       -f              Do not fork to background\n"
 127                 "       -c file         Configuration file, default is '/etc/httpd.conf'\n"
 128                 "       -p [addr:]port  Bind to specified address and port, multiple allowed\n"
 129 #ifdef HAVE_TLS
 130                 "       -s [addr:]port  Like -p but provide HTTPS on this port\n"
 131                 "       -C file         ASN.1 server certificate file\n"
 132                 "       -K file         ASN.1 server private key file\n"
 133 #endif
 134                 "       -h directory    Specify the document root, default is '.'\n"
 135                 "       -E string       Use given virtual URL as 404 error handler\n"
 136                 "       -I string       Use given filename as index for directories, multiple allowed\n"
 137                 "       -S              Do not follow symbolic links outside of the docroot\n"
 138                 "       -D              Do not allow directory listings, send 403 instead\n"
 139                 "       -R              Enable RFC1918 filter\n"
 140                 "       -n count        Maximum allowed number of concurrent requests\n"
 141 #ifdef HAVE_LUA
 142                 "       -l string       URL prefix for Lua handler, default is '/lua'\n"
 143                 "       -L file         Lua handler script, omit to disable Lua\n"
 144 #endif
 145 #ifdef HAVE_UBUS
 146                 "       -u string       URL prefix for HTTP/JSON handler\n"
 147                 "       -U file         Override ubus socket path\n"
 148 #endif
 149                 "       -x string       URL prefix for CGI handler, default is '/cgi-bin'\n"
 150                 "       -i .ext=path    Use interpreter at path for files with the given extension\n"
 151                 "       -t seconds      CGI, Lua and UBUS script timeout in seconds, default is 60\n"
 152                 "       -T seconds      Network timeout in seconds, default is 30\n"
 153                 "       -d string       URL decode given string\n"
 154                 "       -r string       Specify basic auth realm\n"
 155                 "       -m string       MD5 crypt given string\n"
 156                 "\n", name
 157         );
 158         return 1;
 159 }
 160
 161 static void init_defaults(void)
 162 {
 163         conf.script_timeout = 60;
 164         conf.network_timeout = 30;
 165         conf.http_keepalive = 20;
 166         conf.max_requests = 3;
 167         conf.realm = "Protected Area";
 168         conf.cgi_prefix = "/cgi-bin";
 169         conf.cgi_path = "/sbin:/usr/sbin:/bin:/usr/bin";
 170
 171         uh_index_add("index.html");
 172         uh_index_add("index.htm");
 173         uh_index_add("default.html");
 174         uh_index_add("default.htm");
 175 }
 176
 177 static void fixup_prefix(char *str)
 178 {
 179         int len;
 180
 181         if (!str || !str[0])
 182                 return;
 183
 184         len = strlen(str) - 1;
 185
 186         while (len > 0 && str[len] == '/')
 187                 len--;
 188
 189         str[len + 1] = 0;
 190 }
 191
 192 int main(int argc, char **argv)
 193 {
 194         const char *tls_key, *tls_crt;
 195         bool nofork = false;
 196         char *port;
 197         int opt, ch;
 198         int cur_fd;
 199         int bound = 0;
 200         int n_tls = 0;
 201
 202         BUILD_BUG_ON(sizeof(uh_buf) < PATH_MAX);
 203
 204         uh_dispatch_add(&cgi_dispatch);
 205         init_defaults();
 206         signal(SIGPIPE, SIG_IGN);
 207
 208         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) {
 209                 bool tls = false;
 210
 211                 switch(ch) {
 212                 case 's':
 213                         n_tls++;
 214                         tls = true;
 215                         /* fall through */
 216                 case 'p':
 217                         bound += add_listener_arg(optarg, tls);
 218                         break;
 219
 220                 case 'h':
 221                         if (!realpath(optarg, uh_buf)) {
 222                                 fprintf(stderr, "Error: Invalid directory %s: %s\n",
 223                                                 optarg, strerror(errno));
 224                                 exit(1);
 225                         }
 226                         conf.docroot = strdup(uh_buf);
 227                         break;
 228
 229                 case 'E':
 230                         if (optarg[0] != '/') {
 231                                 fprintf(stderr, "Error: Invalid error handler: %s\n",
 232                                                 optarg);
 233                                 exit(1);
 234                         }
 235                         conf.error_handler = optarg;
 236                         break;
 237
 238                 case 'I':
 239                         if (optarg[0] == '/') {
 240                                 fprintf(stderr, "Error: Invalid index page: %s\n",
 241                                                 optarg);
 242                                 exit(1);
 243                         }
 244                         uh_index_add(optarg);
 245                         break;
 246
 247                 case 'S':
 248                         conf.no_symlinks = 1;
 249                         break;
 250
 251                 case 'D':
 252                         conf.no_dirlists = 1;
 253                         break;
 254
 255                 case 'R':
 256                         conf.rfc1918_filter = 1;
 257                         break;
 258
 259                 case 'n':
 260                         conf.max_requests = atoi(optarg);
 261                         break;
 262
 263                 case 'x':
 264                         fixup_prefix(optarg);
 265                         conf.cgi_prefix = optarg;
 266                         break;
 267
 268                 case 'i':
 269                         port = strchr(optarg, '=');
 270                         if (optarg[0] != '.' || !port) {
 271                                 fprintf(stderr, "Error: Invalid interpreter: %s\n",
 272                                                 optarg);
 273                                 exit(1);
 274                         }
 275
 276                         *port++ = 0;
 277                         uh_interpreter_add(optarg, port);
 278                         break;
 279
 280                 case 't':
 281                         conf.script_timeout = atoi(optarg);
 282                         break;
 283
 284                 case 'T':
 285                         conf.network_timeout = atoi(optarg);
 286                         break;
 287
 288                 case 'A':
 289                         conf.tcp_keepalive = atoi(optarg);
 290                         break;
 291
 292                 case 'f':
 293                         nofork = 1;
 294                         break;
 295
 296                 case 'd':
 297                         port = alloca(strlen(optarg) + 1);
 298                         if (!port)
 299                                 return -1;
 300
 301                         /* "decode" plus to space to retain compat */
 302                         for (opt = 0; optarg[opt]; opt++)
 303                                 if (optarg[opt] == '+')
 304                                         optarg[opt] = ' ';
 305
 306                         /* opt now contains strlen(optarg) -- no need to re-scan */
 307                         if (uh_urldecode(port, opt, optarg, opt) < 0) {
 308                                 fprintf(stderr, "uhttpd: invalid encoding\n");
 309                                 return -1;
 310                         }
 311
 312                         printf("%s", port);
 313                         break;
 314
 315                 /* basic auth realm */
 316                 case 'r':
 317                         conf.realm = optarg;
 318                         break;
 319
 320                 /* md5 crypt */
 321                 case 'm':
 322                         printf("%s\n", crypt(optarg, "$1$"));
 323                         return 0;
 324                         break;
 325
 326                 /* config file */
 327                 case 'c':
 328                         conf.file = optarg;
 329                         break;
 330
 331                 case 'C':
 332                         tls_crt = optarg;
 333                         break;
 334
 335                 case 'K':
 336                         tls_key = optarg;
 337                         break;
 338                 default:
 339                         return usage(argv[0]);
 340                 }
 341         }
 342
 343         uh_config_parse();
 344
 345         if (!bound) {
 346                 fprintf(stderr, "Error: No sockets bound, unable to continue\n");
 347                 return 1;
 348         }
 349
 350         if (n_tls) {
 351                 if (!tls_crt || !tls_key) {
 352                         fprintf(stderr, "Please specify a certificate and "
 353                                         "a key file to enable SSL support\n");
 354                         return 1;
 355                 }
 356
 357 #ifdef HAVE_TLS
 358                 if (uh_tls_init(tls_key, tls_crt))
 359                     return 1;
 360 #else
 361                 fprintf(stderr, "Error: TLS support not compiled in.\n");
 362                 return 1;
 363 #endif
 364         }
 365
 366         /* fork (if not disabled) */
 367         if (!nofork) {
 368                 switch (fork()) {
 369                 case -1:
 370                         perror("fork()");
 371                         exit(1);
 372
 373                 case 0:
 374                         /* daemon setup */
 375                         if (chdir("/"))
 376                                 perror("chdir()");
 377
 378                         cur_fd = open("/dev/null", O_WRONLY);
 379                         if (cur_fd > 0) {
 380                                 dup2(cur_fd, 0);
 381                                 dup2(cur_fd, 1);
 382                                 dup2(cur_fd, 2);
 383                         }
 384
 385                         break;
 386
 387                 default:
 388                         exit(0);
 389                 }
 390         }
 391
 392         return run_server();
 393 }