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 _GNU_SOURCE
  21 #define _XOPEN_SOURCE   700
  22 #include <sys/types.h>
  23 #include <sys/socket.h>
  24 #include <netinet/in.h>
  25
  26 #include <getopt.h>
  27 #include <errno.h>
  28 #include <netdb.h>
  29 #include <signal.h>
  30 #include <unistd.h>
  31
  32 #include <libubox/usock.h>
  33
  34 #include "uhttpd.h"
  35
  36 char uh_buf[4096];
  37
  38 static int run_server(void)
  39 {
  40         uloop_init();
  41         uh_setup_listeners();
  42         uloop_run();
  43
  44         return 0;
  45 }
  46
  47 static void uh_config_parse(void)
  48 {
  49         const char *path = conf.file;
  50         FILE *c;
  51         char line[512];
  52         char *col1;
  53         char *col2;
  54         char *eol;
  55
  56         if (!path)
  57                 path = "/etc/httpd.conf";
  58
  59         c = fopen(path, "r");
  60         if (!c)
  61                 return;
  62
  63         memset(line, 0, sizeof(line));
  64
  65         while (fgets(line, sizeof(line) - 1, c)) {
  66                 if ((line[0] == '/') && (strchr(line, ':') != NULL)) {
  67                         if (!(col1 = strchr(line, ':')) || (*col1++ = 0) ||
  68                                 !(col2 = strchr(col1, ':')) || (*col2++ = 0) ||
  69                                 !(eol = strchr(col2, '\n')) || (*eol++  = 0))
  70                                 continue;
  71
  72                         uh_auth_add(line, col1, col2);
  73                 } else if (!strncmp(line, "I:", 2)) {
  74                         if (!(col1 = strchr(line, ':')) || (*col1++ = 0) ||
  75                                 !(eol = strchr(col1, '\n')) || (*eol++  = 0))
  76                                 continue;
  77
  78                         uh_index_add(strdup(col1));
  79                 } else if (!strncmp(line, "E404:", 5)) {
  80                         if (!(col1 = strchr(line, ':')) || (*col1++ = 0) ||
  81                                 !(eol = strchr(col1, '\n')) || (*eol++  = 0))
  82                                 continue;
  83
  84                         conf.error_handler = strdup(col1);
  85                 }
  86 #ifdef HAVE_CGI
  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                         if (!uh_interpreter_add(col1, col2))
  94                                 fprintf(stderr,
  95                                                 "Unable to add interpreter %s for extension %s: "
  96                                                 "Out of memory\n", col2, col1
  97                                 );
  98                 }
  99 #endif
 100         }
 101
 102         fclose(c);
 103 }
 104
 105 static int add_listener_arg(char *arg, bool tls)
 106 {
 107         char *host = NULL;
 108         char *port = arg;
 109         char *s;
 110
 111         s = strrchr(arg, ':');
 112         if (s) {
 113                 host = arg;
 114                 port = s + 1;
 115                 *s = 0;
 116         }
 117
 118         return uh_socket_bind(host, port, tls);
 119 }
 120
 121 static int usage(const char *name)
 122 {
 123         fprintf(stderr,
 124                 "Usage: %s -p [addr:]port -h docroot\n"
 125                 "       -f              Do not fork to background\n"
 126                 "       -c file         Configuration file, default is '/etc/httpd.conf'\n"
 127                 "       -p [addr:]port  Bind to specified address and port, multiple allowed\n"
 128 #ifdef HAVE_TLS
 129                 "       -s [addr:]port  Like -p but provide HTTPS on this port\n"
 130                 "       -C file         ASN.1 server certificate file\n"
 131                 "       -K file         ASN.1 server private key file\n"
 132 #endif
 133                 "       -h directory    Specify the document root, default is '.'\n"
 134                 "       -E string       Use given virtual URL as 404 error handler\n"
 135                 "       -I string       Use given filename as index for directories, multiple allowed\n"
 136                 "       -S              Do not follow symbolic links outside of the docroot\n"
 137                 "       -D              Do not allow directory listings, send 403 instead\n"
 138                 "       -R              Enable RFC1918 filter\n"
 139                 "       -n count        Maximum allowed number of concurrent requests\n"
 140 #ifdef HAVE_LUA
 141                 "       -l string       URL prefix for Lua handler, default is '/lua'\n"
 142                 "       -L file         Lua handler script, omit to disable Lua\n"
 143 #endif
 144 #ifdef HAVE_UBUS
 145                 "       -u string       URL prefix for HTTP/JSON handler\n"
 146                 "       -U file         Override ubus socket path\n"
 147 #endif
 148                 "       -x string       URL prefix for CGI handler, default is '/cgi-bin'\n"
 149                 "       -i .ext=path    Use interpreter at path for files with the given extension\n"
 150                 "       -t seconds      CGI, Lua and UBUS script timeout in seconds, default is 60\n"
 151                 "       -T seconds      Network timeout in seconds, default is 30\n"
 152                 "       -d string       URL decode given string\n"
 153                 "       -r string       Specify basic auth realm\n"
 154                 "       -m string       MD5 crypt given string\n"
 155                 "\n", name
 156         );
 157         return 1;
 158 }
 159
 160 static void init_defaults(void)
 161 {
 162         conf.script_timeout = 60;
 163         conf.network_timeout = 30;
 164         conf.http_keepalive = 20;
 165         conf.max_requests = 3;
 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         BUILD_BUG_ON(sizeof(uh_buf) < PATH_MAX);
 200
 201         uh_dispatch_add(&cgi_dispatch);
 202         init_defaults();
 203         signal(SIGPIPE, SIG_IGN);
 204
 205         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) {
 206                 bool tls = false;
 207
 208                 switch(ch) {
 209                 case 's':
 210                         tls = true;
 211                         /* fall through */
 212                 case 'p':
 213                         bound += add_listener_arg(optarg, tls);
 214                         break;
 215
 216                 case 'h':
 217                         if (!realpath(optarg, uh_buf)) {
 218                                 fprintf(stderr, "Error: Invalid directory %s: %s\n",
 219                                                 optarg, strerror(errno));
 220                                 exit(1);
 221                         }
 222                         conf.docroot = strdup(uh_buf);
 223                         break;
 224
 225                 case 'E':
 226                         if (optarg[0] != '/') {
 227                                 fprintf(stderr, "Error: Invalid error handler: %s\n",
 228                                                 optarg);
 229                                 exit(1);
 230                         }
 231                         conf.error_handler = optarg;
 232                         break;
 233
 234                 case 'I':
 235                         if (optarg[0] == '/') {
 236                                 fprintf(stderr, "Error: Invalid index page: %s\n",
 237                                                 optarg);
 238                                 exit(1);
 239                         }
 240                         uh_index_add(optarg);
 241                         break;
 242
 243                 case 'S':
 244                         conf.no_symlinks = 1;
 245                         break;
 246
 247                 case 'D':
 248                         conf.no_dirlists = 1;
 249                         break;
 250
 251                 case 'R':
 252                         conf.rfc1918_filter = 1;
 253                         break;
 254
 255                 case 'n':
 256                         conf.max_requests = atoi(optarg);
 257                         break;
 258
 259                 case 'x':
 260                         fixup_prefix(optarg);
 261                         conf.cgi_prefix = optarg;
 262                         break;
 263
 264                 case 'i':
 265                         port = strchr(optarg, '=');
 266                         if (optarg[0] != '.' || !port) {
 267                                 fprintf(stderr, "Error: Invalid interpreter: %s\n",
 268                                                 optarg);
 269                                 exit(1);
 270                         }
 271
 272                         *port++ = 0;
 273                         uh_interpreter_add(optarg, port);
 274                         break;
 275
 276                 case 't':
 277                         conf.script_timeout = atoi(optarg);
 278                         break;
 279
 280                 case 'T':
 281                         conf.network_timeout = atoi(optarg);
 282                         break;
 283
 284                 case 'A':
 285                         conf.tcp_keepalive = atoi(optarg);
 286                         break;
 287
 288                 case 'f':
 289                         nofork = 1;
 290                         break;
 291
 292                 case 'd':
 293                         port = alloca(strlen(optarg) + 1);
 294                         if (!port)
 295                                 return -1;
 296
 297                         /* "decode" plus to space to retain compat */
 298                         for (opt = 0; optarg[opt]; opt++)
 299                                 if (optarg[opt] == '+')
 300                                         optarg[opt] = ' ';
 301
 302                         /* opt now contains strlen(optarg) -- no need to re-scan */
 303                         if (uh_urldecode(port, opt, optarg, opt) < 0) {
 304                                 fprintf(stderr, "uhttpd: invalid encoding\n");
 305                                 return -1;
 306                         }
 307
 308                         printf("%s", port);
 309                         break;
 310
 311                 /* basic auth realm */
 312                 case 'r':
 313                         conf.realm = optarg;
 314                         break;
 315
 316                 /* md5 crypt */
 317                 case 'm':
 318                         printf("%s\n", crypt(optarg, "$1$"));
 319                         return 0;
 320                         break;
 321
 322                 /* config file */
 323                 case 'c':
 324                         conf.file = optarg;
 325                         break;
 326
 327                 default:
 328                         return usage(argv[0]);
 329                 }
 330         }
 331
 332         uh_config_parse();
 333
 334         if (!bound) {
 335                 fprintf(stderr, "Error: No sockets bound, unable to continue\n");
 336                 return 1;
 337         }
 338
 339         /* fork (if not disabled) */
 340         if (!nofork) {
 341                 switch (fork()) {
 342                 case -1:
 343                         perror("fork()");
 344                         exit(1);
 345
 346                 case 0:
 347                         /* daemon setup */
 348                         if (chdir("/"))
 349                                 perror("chdir()");
 350
 351                         cur_fd = open("/dev/null", O_WRONLY);
 352                         if (cur_fd > 0) {
 353                                 dup2(cur_fd, 0);
 354                                 dup2(cur_fd, 1);
 355                                 dup2(cur_fd, 2);
 356                         }
 357
 358                         break;
 359
 360                 default:
 361                         exit(0);
 362                 }
 363         }
 364
 365         return run_server();
 366 }