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 #include <sys/types.h>
  21 #include <sys/socket.h>
  22 #include <netinet/in.h>
  23
  24 #include <getopt.h>
  25 #include <errno.h>
  26 #include <netdb.h>
  27 #include <signal.h>
  28
  29 #include <libubox/usock.h>
  30
  31 #include "uhttpd.h"
  32
  33 char uh_buf[4096];
  34
  35 static int run_server(void)
  36 {
  37         uloop_init();
  38         uh_setup_listeners();
  39         uloop_run();
  40
  41         return 0;
  42 }
  43
  44 static void uh_config_parse(void)
  45 {
  46         const char *path = conf.file;
  47         FILE *c;
  48         char line[512];
  49         char *col1;
  50         char *col2;
  51         char *eol;
  52
  53         if (!path)
  54                 path = "/etc/httpd.conf";
  55
  56         c = fopen(path, "r");
  57         if (!c)
  58                 return;
  59
  60         memset(line, 0, sizeof(line));
  61
  62         while (fgets(line, sizeof(line) - 1, c)) {
  63                 if ((line[0] == '/') && (strchr(line, ':') != NULL)) {
  64                         if (!(col1 = strchr(line, ':')) || (*col1++ = 0) ||
  65                                 !(col2 = strchr(col1, ':')) || (*col2++ = 0) ||
  66                                 !(eol = strchr(col2, '\n')) || (*eol++  = 0))
  67                                 continue;
  68
  69                         uh_auth_add(line, col1, col2);
  70                 } else if (!strncmp(line, "I:", 2)) {
  71                         if (!(col1 = strchr(line, ':')) || (*col1++ = 0) ||
  72                                 !(eol = strchr(col1, '\n')) || (*eol++  = 0))
  73                                 continue;
  74
  75                         uh_index_add(strdup(col1));
  76                 } else if (!strncmp(line, "E404:", 5)) {
  77                         if (!(col1 = strchr(line, ':')) || (*col1++ = 0) ||
  78                                 !(eol = strchr(col1, '\n')) || (*eol++  = 0))
  79                                 continue;
  80
  81                         conf.error_handler = strdup(col1);
  82                 }
  83 #ifdef HAVE_CGI
  84                 else if ((line[0] == '*') && (strchr(line, ':') != NULL)) {
  85                         if (!(col1 = strchr(line, '*')) || (*col1++ = 0) ||
  86                                 !(col2 = strchr(col1, ':')) || (*col2++ = 0) ||
  87                                 !(eol = strchr(col2, '\n')) || (*eol++  = 0))
  88                                 continue;
  89
  90                         if (!uh_interpreter_add(col1, col2))
  91                                 fprintf(stderr,
  92                                                 "Unable to add interpreter %s for extension %s: "
  93                                                 "Out of memory\n", col2, col1
  94                                 );
  95                 }
  96 #endif
  97         }
  98
  99         fclose(c);
 100 }
 101
 102 static int add_listener_arg(char *arg, bool tls)
 103 {
 104         char *host = NULL;
 105         char *port = arg;
 106         char *s;
 107
 108         s = strrchr(arg, ':');
 109         if (s) {
 110                 host = arg;
 111                 port = s + 1;
 112                 *s = 0;
 113         }
 114
 115         return uh_socket_bind(host, port, tls);
 116 }
 117
 118 static int usage(const char *name)
 119 {
 120         fprintf(stderr,
 121                 "Usage: %s -p [addr:]port -h docroot\n"
 122                 "       -f              Do not fork to background\n"
 123                 "       -c file         Configuration file, default is '/etc/httpd.conf'\n"
 124                 "       -p [addr:]port  Bind to specified address and port, multiple allowed\n"
 125 #ifdef HAVE_TLS
 126                 "       -s [addr:]port  Like -p but provide HTTPS on this port\n"
 127                 "       -C file         ASN.1 server certificate file\n"
 128                 "       -K file         ASN.1 server private key file\n"
 129 #endif
 130                 "       -h directory    Specify the document root, default is '.'\n"
 131                 "       -E string       Use given virtual URL as 404 error handler\n"
 132                 "       -I string       Use given filename as index for directories, multiple allowed\n"
 133                 "       -S              Do not follow symbolic links outside of the docroot\n"
 134                 "       -D              Do not allow directory listings, send 403 instead\n"
 135                 "       -R              Enable RFC1918 filter\n"
 136                 "       -n count        Maximum allowed number of concurrent requests\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 HTTP/JSON handler\n"
 143                 "       -U file         Override ubus socket path\n"
 144 #endif
 145                 "       -x string       URL prefix for CGI handler, default is '/cgi-bin'\n"
 146                 "       -i .ext=path    Use interpreter at path for files with the given extension\n"
 147                 "       -t seconds      CGI, Lua and UBUS script timeout in seconds, default is 60\n"
 148                 "       -T seconds      Network timeout in seconds, default is 30\n"
 149                 "       -d string       URL decode given string\n"
 150                 "       -r string       Specify basic auth realm\n"
 151                 "       -m string       MD5 crypt given string\n"
 152                 "\n", name
 153         );
 154         return 1;
 155 }
 156
 157 static void init_defaults(void)
 158 {
 159         conf.script_timeout = 60;
 160         conf.network_timeout = 30;
 161         conf.http_keepalive = 20;
 162         conf.max_requests = 3;
 163         conf.realm = "Protected Area";
 164         conf.cgi_prefix = "/cgi-bin";
 165         conf.cgi_path = "/sbin:/usr/sbin:/bin:/usr/bin";
 166
 167         uh_index_add("index.html");
 168         uh_index_add("index.htm");
 169         uh_index_add("default.html");
 170         uh_index_add("default.htm");
 171 }
 172
 173 static void fixup_prefix(char *str)
 174 {
 175         int len;
 176
 177         if (!str || !str[0])
 178                 return;
 179
 180         len = strlen(str) - 1;
 181
 182         while (len > 0 && str[len] == '/')
 183                 len--;
 184
 185         str[len + 1] = 0;
 186 }
 187
 188 int main(int argc, char **argv)
 189 {
 190         bool nofork = false;
 191         char *port;
 192         int opt, ch;
 193         int cur_fd;
 194         int bound = 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                         tls = true;
 208                         /* fall through */
 209                 case 'p':
 210                         bound += add_listener_arg(optarg, tls);
 211                         break;
 212
 213                 case 'h':
 214                         if (!realpath(optarg, uh_buf)) {
 215                                 fprintf(stderr, "Error: Invalid directory %s: %s\n",
 216                                                 optarg, strerror(errno));
 217                                 exit(1);
 218                         }
 219                         conf.docroot = strdup(uh_buf);
 220                         break;
 221
 222                 case 'E':
 223                         if (optarg[0] != '/') {
 224                                 fprintf(stderr, "Error: Invalid error handler: %s\n",
 225                                                 optarg);
 226                                 exit(1);
 227                         }
 228                         conf.error_handler = optarg;
 229                         break;
 230
 231                 case 'I':
 232                         if (optarg[0] == '/') {
 233                                 fprintf(stderr, "Error: Invalid index page: %s\n",
 234                                                 optarg);
 235                                 exit(1);
 236                         }
 237                         uh_index_add(optarg);
 238                         break;
 239
 240                 case 'S':
 241                         conf.no_symlinks = 1;
 242                         break;
 243
 244                 case 'D':
 245                         conf.no_dirlists = 1;
 246                         break;
 247
 248                 case 'R':
 249                         conf.rfc1918_filter = 1;
 250                         break;
 251
 252                 case 'n':
 253                         conf.max_requests = atoi(optarg);
 254                         break;
 255
 256                 case 'x':
 257                         fixup_prefix(optarg);
 258                         conf.cgi_prefix = optarg;
 259                         break;
 260
 261                 case 'i':
 262                         port = strchr(optarg, '=');
 263                         if (optarg[0] != '.' || !port) {
 264                                 fprintf(stderr, "Error: Invalid interpreter: %s\n",
 265                                                 optarg);
 266                                 exit(1);
 267                         }
 268
 269                         *port++ = 0;
 270                         uh_interpreter_add(optarg, port);
 271                         break;
 272
 273                 case 't':
 274                         conf.script_timeout = atoi(optarg);
 275                         break;
 276
 277                 case 'T':
 278                         conf.network_timeout = atoi(optarg);
 279                         break;
 280
 281                 case 'A':
 282                         conf.tcp_keepalive = atoi(optarg);
 283                         break;
 284
 285                 case 'f':
 286                         nofork = 1;
 287                         break;
 288
 289                 case 'd':
 290                         port = alloca(strlen(optarg) + 1);
 291                         if (!port)
 292                                 return -1;
 293
 294                         /* "decode" plus to space to retain compat */
 295                         for (opt = 0; optarg[opt]; opt++)
 296                                 if (optarg[opt] == '+')
 297                                         optarg[opt] = ' ';
 298
 299                         /* opt now contains strlen(optarg) -- no need to re-scan */
 300                         if (uh_urldecode(port, opt, optarg, opt) < 0) {
 301                                 fprintf(stderr, "uhttpd: invalid encoding\n");
 302                                 return -1;
 303                         }
 304
 305                         printf("%s", port);
 306                         break;
 307
 308                 /* basic auth realm */
 309                 case 'r':
 310                         conf.realm = optarg;
 311                         break;
 312
 313                 /* md5 crypt */
 314                 case 'm':
 315                         printf("%s\n", crypt(optarg, "$1$"));
 316                         return 0;
 317                         break;
 318
 319                 /* config file */
 320                 case 'c':
 321                         conf.file = optarg;
 322                         break;
 323
 324                 default:
 325                         return usage(argv[0]);
 326                 }
 327         }
 328
 329         uh_config_parse();
 330
 331         if (!bound) {
 332                 fprintf(stderr, "Error: No sockets bound, unable to continue\n");
 333                 return 1;
 334         }
 335
 336         /* fork (if not disabled) */
 337         if (!nofork) {
 338                 switch (fork()) {
 339                 case -1:
 340                         perror("fork()");
 341                         exit(1);
 342
 343                 case 0:
 344                         /* daemon setup */
 345                         if (chdir("/"))
 346                                 perror("chdir()");
 347
 348                         cur_fd = open("/dev/null", O_WRONLY);
 349                         if (cur_fd > 0) {
 350                                 dup2(cur_fd, 0);
 351                                 dup2(cur_fd, 1);
 352                                 dup2(cur_fd, 2);
 353                         }
 354
 355                         break;
 356
 357                 default:
 358                         exit(0);
 359                 }
 360         }
 361
 362         return run_server();
 363 }