package/uhttpd/src/uhttpd.c

   1 /*
   2  * uhttpd - Tiny single-threaded httpd - Main component
   3  *
   4  *   Copyright (C) 2010 Jo-Philipp Wich <xm@subsignal.org>
   5  *
   6  *  Licensed under the Apache License, Version 2.0 (the "License");
   7  *  you may not use this file except in compliance with the License.
   8  *  You may obtain a copy of the License at
   9  *
  10  *      http://www.apache.org/licenses/LICENSE-2.0
  11  *
  12  *  Unless required by applicable law or agreed to in writing, software
  13  *  distributed under the License is distributed on an "AS IS" BASIS,
  14  *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  15  *  See the License for the specific language governing permissions and
  16  *  limitations under the License.
  17  */
  18
  19 #define _XOPEN_SOURCE 500       /* crypt() */
  20
  21 #include "uhttpd.h"
  22 #include "uhttpd-utils.h"
  23 #include "uhttpd-file.h"
  24
  25 #ifdef HAVE_CGI
  26 #include "uhttpd-cgi.h"
  27 #endif
  28
  29 #ifdef HAVE_LUA
  30 #include "uhttpd-lua.h"
  31 #endif
  32
  33 #ifdef HAVE_TLS
  34 #include "uhttpd-tls.h"
  35 #endif
  36
  37
  38 static int run = 1;
  39
  40 static void uh_sigterm(int sig)
  41 {
  42         run = 0;
  43 }
  44
  45 static void uh_sigchld(int sig)
  46 {
  47         while( waitpid(-1, NULL, WNOHANG) > 0 ) { }
  48 }
  49
  50 static void uh_config_parse(const char *path)
  51 {
  52         FILE *c;
  53         char line[512];
  54         char *user = NULL;
  55         char *pass = NULL;
  56         char *eol  = NULL;
  57
  58         if( (c = fopen(path ? path : "/etc/httpd.conf", "r")) != NULL )
  59         {
  60                 memset(line, 0, sizeof(line));
  61
  62                 while( fgets(line, sizeof(line) - 1, c) )
  63                 {
  64                         if( (line[0] == '/') && (strchr(line, ':') != NULL) )
  65                         {
  66                                 if( !(user = strchr(line, ':')) || (*user++ = 0) ||
  67                                     !(pass = strchr(user, ':')) || (*pass++ = 0) ||
  68                                         !(eol = strchr(pass, '\n')) || (*eol++  = 0) )
  69                                                 continue;
  70
  71                                 if( !uh_auth_add(line, user, pass) )
  72                                 {
  73                                         fprintf(stderr,
  74                                                 "Notice: No password set for user %s, ignoring "
  75                                                 "authentication on %s\n", user, line
  76                                         );
  77
  78                                         break;
  79                                 }
  80                         }
  81                 }
  82
  83                 fclose(c);
  84         }
  85 }
  86
  87 static int uh_socket_bind(
  88         fd_set *serv_fds, int *max_fd, const char *host, const char *port,
  89         struct addrinfo *hints, int do_tls, struct config *conf
  90 ) {
  91         int sock = -1;
  92         int yes = 1;
  93         int status;
  94         int bound = 0;
  95
  96         struct listener *l = NULL;
  97         struct addrinfo *addrs = NULL, *p = NULL;
  98
  99         if( (status = getaddrinfo(host, port, hints, &addrs)) != 0 )
 100         {
 101                 fprintf(stderr, "getaddrinfo(): %s\n", gai_strerror(status));
 102         }
 103
 104         /* try to bind a new socket to each found address */
 105         for( p = addrs; p; p = p->ai_next )
 106         {
 107                 /* get the socket */
 108                 if( (sock = socket(p->ai_family, p->ai_socktype, p->ai_protocol)) == -1 )
 109                 {
 110                         perror("socket()");
 111                         goto error;
 112                 }
 113
 114                 /* "address already in use" */
 115                 if( setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(yes)) == -1 )
 116                 {
 117                         perror("setsockopt()");
 118                         goto error;
 119                 }
 120
 121                 /* required to get parallel v4 + v6 working */
 122                 if( p->ai_family == AF_INET6 )
 123                 {
 124                         if( setsockopt(sock, IPPROTO_IPV6, IPV6_V6ONLY, &yes, sizeof(yes)) == -1 )
 125                         {
 126                                 perror("setsockopt()");
 127                                 goto error;
 128                         }
 129                 }
 130
 131                 /* bind */
 132                 if( bind(sock, p->ai_addr, p->ai_addrlen) == -1 )
 133                 {
 134                         perror("bind()");
 135                         goto error;
 136                 }
 137
 138                 /* listen */
 139                 if( listen(sock, UH_LIMIT_CLIENTS) == -1 )
 140                 {
 141                         perror("listen()");
 142                         goto error;
 143                 }
 144
 145                 /* add listener to global list */
 146                 if( ! (l = uh_listener_add(sock, conf)) )
 147                 {
 148                         fprintf(stderr,
 149                                 "uh_listener_add(): Can not create more than "
 150                                 "%i listen sockets\n", UH_LIMIT_LISTENERS
 151                         );
 152
 153                         goto error;
 154                 }
 155
 156 #ifdef HAVE_TLS
 157                 /* init TLS */
 158                 l->tls = do_tls ? conf->tls : NULL;
 159 #endif
 160
 161                 /* add socket to server fd set */
 162                 FD_SET(sock, serv_fds);
 163                 fd_cloexec(sock);
 164                 *max_fd = max(*max_fd, sock);
 165
 166                 bound++;
 167                 continue;
 168
 169                 error:
 170                 if( sock > 0 )
 171                         close(sock);
 172         }
 173
 174         freeaddrinfo(addrs);
 175
 176         return bound;
 177 }
 178
 179 static struct http_request * uh_http_header_parse(struct client *cl, char *buffer, int buflen)
 180 {
 181         char *method  = &buffer[0];
 182         char *path    = NULL;
 183         char *version = NULL;
 184
 185         char *headers = NULL;
 186         char *hdrname = NULL;
 187         char *hdrdata = NULL;
 188
 189         int i;
 190         int hdrcount = 0;
 191
 192         static struct http_request req;
 193
 194         memset(&req, 0, sizeof(req));
 195
 196
 197         /* terminate initial header line */
 198         if( (headers = strfind(buffer, buflen, "\r\n", 2)) != NULL )
 199         {
 200                 buffer[buflen-1] = 0;
 201
 202                 *headers++ = 0;
 203                 *headers++ = 0;
 204
 205                 /* find request path */
 206                 if( (path = strchr(buffer, ' ')) != NULL )
 207                         *path++ = 0;
 208
 209                 /* find http version */
 210                 if( (path != NULL) && ((version = strchr(path, ' ')) != NULL) )
 211                         *version++ = 0;
 212
 213
 214                 /* check method */
 215                 if( strcmp(method, "GET") && strcmp(method, "HEAD") && strcmp(method, "POST") )
 216                 {
 217                         /* invalid method */
 218                         uh_http_response(cl, 405, "Method Not Allowed");
 219                         return NULL;
 220                 }
 221                 else
 222                 {
 223                         switch(method[0])
 224                         {
 225                                 case 'G':
 226                                         req.method = UH_HTTP_MSG_GET;
 227                                         break;
 228
 229                                 case 'H':
 230                                         req.method = UH_HTTP_MSG_HEAD;
 231                                         break;
 232
 233                                 case 'P':
 234                                         req.method = UH_HTTP_MSG_POST;
 235                                         break;
 236                         }
 237                 }
 238
 239                 /* check path */
 240                 if( !path || !strlen(path) )
 241                 {
 242                         /* malformed request */
 243                         uh_http_response(cl, 400, "Bad Request");
 244                         return NULL;
 245                 }
 246                 else
 247                 {
 248                         req.url = path;
 249                 }
 250
 251                 /* check version */
 252                 if( strcmp(version, "HTTP/0.9") && strcmp(version, "HTTP/1.0") && strcmp(version, "HTTP/1.1") )
 253                 {
 254                         /* unsupported version */
 255                         uh_http_response(cl, 400, "Bad Request");
 256                         return NULL;
 257                 }
 258                 else
 259                 {
 260                         req.version = strtof(&version[5], NULL);
 261                 }
 262
 263
 264                 /* process header fields */
 265                 for( i = (int)(headers - buffer); i < buflen; i++ )
 266                 {
 267                         /* found eol and have name + value, push out header tuple */
 268                         if( hdrname && hdrdata && (buffer[i] == '\r' || buffer[i] == '\n') )
 269                         {
 270                                 buffer[i] = 0;
 271
 272                                 /* store */
 273                                 if( (hdrcount + 1) < array_size(req.headers) )
 274                                 {
 275                                         req.headers[hdrcount++] = hdrname;
 276                                         req.headers[hdrcount++] = hdrdata;
 277
 278                                         hdrname = hdrdata = NULL;
 279                                 }
 280
 281                                 /* too large */
 282                                 else
 283                                 {
 284                                         uh_http_response(cl, 413, "Request Entity Too Large");
 285                                         return NULL;
 286                                 }
 287                         }
 288
 289                         /* have name but no value and found a colon, start of value */
 290                         else if( hdrname && !hdrdata && ((i+2) < buflen) &&
 291                                 (buffer[i] == ':') && (buffer[i+1] == ' ')
 292                         ) {
 293                                 buffer[i] = 0;
 294                                 hdrdata = &buffer[i+2];
 295                         }
 296
 297                         /* have no name and found [A-Z], start of name */
 298                         else if( !hdrname && isalpha(buffer[i]) && isupper(buffer[i]) )
 299                         {
 300                                 hdrname = &buffer[i];
 301                         }
 302                 }
 303
 304                 /* valid enough */
 305                 return &req;
 306         }
 307
 308         /* Malformed request */
 309         uh_http_response(cl, 400, "Bad Request");
 310         return NULL;
 311 }
 312
 313
 314 static struct http_request * uh_http_header_recv(struct client *cl)
 315 {
 316         static char buffer[UH_LIMIT_MSGHEAD];
 317         char *bufptr = &buffer[0];
 318         char *idxptr = NULL;
 319
 320         struct timeval timeout;
 321
 322         fd_set reader;
 323
 324         ssize_t blen = sizeof(buffer)-1;
 325         ssize_t rlen = 0;
 326
 327
 328         memset(buffer, 0, sizeof(buffer));
 329
 330         while( blen > 0 )
 331         {
 332                 FD_ZERO(&reader);
 333                 FD_SET(cl->socket, &reader);
 334
 335                 /* fail after 0.1s */
 336                 timeout.tv_sec  = 0;
 337                 timeout.tv_usec = 100000;
 338
 339                 /* check whether fd is readable */
 340                 if( select(cl->socket + 1, &reader, NULL, NULL, &timeout) > 0 )
 341                 {
 342                         /* receive data */
 343                         rlen = uh_tcp_peek(cl, bufptr, blen);
 344
 345                         if( rlen > 0 )
 346                         {
 347                                 if( (idxptr = strfind(buffer, sizeof(buffer), "\r\n\r\n", 4)) )
 348                                 {
 349                                         blen -= uh_tcp_recv(cl, bufptr, (int)(idxptr - bufptr) + 4);
 350
 351                                         /* header read complete ... */
 352                                         return uh_http_header_parse(cl, buffer, sizeof(buffer) - blen - 1);
 353                                 }
 354                                 else
 355                                 {
 356                                         rlen = uh_tcp_recv(cl, bufptr, rlen);
 357                                         blen -= rlen;
 358                                         bufptr += rlen;
 359                                 }
 360                         }
 361                         else
 362                         {
 363                                 /* invalid request (unexpected eof/timeout) */
 364                                 uh_http_response(cl, 408, "Request Timeout");
 365                                 return NULL;
 366                         }
 367                 }
 368                 else
 369                 {
 370                         /* invalid request (unexpected eof/timeout) */
 371                         uh_http_response(cl, 408, "Request Timeout");
 372                         return NULL;
 373                 }
 374         }
 375
 376         /* request entity too large */
 377         uh_http_response(cl, 413, "Request Entity Too Large");
 378         return NULL;
 379 }
 380
 381 static int uh_path_match(const char *prefix, const char *url)
 382 {
 383         if( (strstr(url, prefix) == url) &&
 384             ((prefix[strlen(prefix)-1] == '/') ||
 385                  (strlen(url) == strlen(prefix))   ||
 386                  (url[strlen(prefix)] == '/'))
 387         ) {
 388                 return 1;
 389         }
 390
 391         return 0;
 392 }
 393
 394
 395 int main (int argc, char **argv)
 396 {
 397 #ifdef HAVE_LUA
 398         /* Lua runtime */
 399         lua_State *L = NULL;
 400 #endif
 401
 402         /* master file descriptor list */
 403         fd_set used_fds, serv_fds, read_fds;
 404
 405         /* working structs */
 406         struct addrinfo hints;
 407         struct http_request *req;
 408         struct path_info *pin;
 409         struct client *cl;
 410         struct sigaction sa;
 411         struct config conf;
 412
 413         /* signal mask */
 414         sigset_t ss;
 415
 416         /* maximum file descriptor number */
 417         int new_fd, cur_fd, max_fd = 0;
 418
 419 #ifdef HAVE_TLS
 420         int tls = 0;
 421         int keys = 0;
 422 #endif
 423
 424         int bound = 0;
 425         int nofork = 0;
 426
 427         /* args */
 428         int opt;
 429         char bind[128];
 430         char *port = NULL;
 431
 432 #if defined(HAVE_TLS) || defined(HAVE_LUA)
 433         /* library handle */
 434         void *lib;
 435 #endif
 436
 437         /* clear the master and temp sets */
 438         FD_ZERO(&used_fds);
 439         FD_ZERO(&serv_fds);
 440         FD_ZERO(&read_fds);
 441
 442         /* handle SIGPIPE, SIGINT, SIGTERM, SIGCHLD */
 443         sa.sa_flags = 0;
 444         sigemptyset(&sa.sa_mask);
 445
 446         sa.sa_handler = SIG_IGN;
 447         sigaction(SIGPIPE, &sa, NULL);
 448
 449         sa.sa_handler = uh_sigchld;
 450         sigaction(SIGCHLD, &sa, NULL);
 451
 452         sa.sa_handler = uh_sigterm;
 453         sigaction(SIGINT,  &sa, NULL);
 454         sigaction(SIGTERM, &sa, NULL);
 455
 456         /* defer SIGCHLD */
 457         sigemptyset(&ss);
 458         sigaddset(&ss, SIGCHLD);
 459         sigprocmask(SIG_BLOCK, &ss, NULL);
 460
 461         /* prepare addrinfo hints */
 462         memset(&hints, 0, sizeof(hints));
 463         hints.ai_family   = AF_UNSPEC;
 464         hints.ai_socktype = SOCK_STREAM;
 465         hints.ai_flags    = AI_PASSIVE;
 466
 467         /* parse args */
 468         memset(&conf, 0, sizeof(conf));
 469         memset(bind, 0, sizeof(bind));
 470
 471 #ifdef HAVE_TLS
 472         /* load TLS plugin */
 473         if( ! (lib = dlopen("uhttpd_tls.so", RTLD_LAZY | RTLD_GLOBAL)) )
 474         {
 475                 fprintf(stderr,
 476                         "Notice: Unable to load TLS plugin - disabling SSL support! "
 477                         "(Reason: %s)\n", dlerror()
 478                 );
 479         }
 480         else
 481         {
 482                 /* resolve functions */
 483                 if( !(conf.tls_init   = dlsym(lib, "uh_tls_ctx_init"))      ||
 484                     !(conf.tls_cert   = dlsym(lib, "uh_tls_ctx_cert"))      ||
 485                     !(conf.tls_key    = dlsym(lib, "uh_tls_ctx_key"))       ||
 486                     !(conf.tls_free   = dlsym(lib, "uh_tls_ctx_free"))      ||
 487                         !(conf.tls_accept = dlsym(lib, "uh_tls_client_accept")) ||
 488                         !(conf.tls_close  = dlsym(lib, "uh_tls_client_close"))  ||
 489                         !(conf.tls_recv   = dlsym(lib, "uh_tls_client_recv"))   ||
 490                         !(conf.tls_send   = dlsym(lib, "uh_tls_client_send"))
 491                 ) {
 492                         fprintf(stderr,
 493                                 "Error: Failed to lookup required symbols "
 494                                 "in TLS plugin: %s\n", dlerror()
 495                         );
 496                         exit(1);
 497                 }
 498
 499                 /* init SSL context */
 500                 if( ! (conf.tls = conf.tls_init()) )
 501                 {
 502                         fprintf(stderr, "Error: Failed to initalize SSL context\n");
 503                         exit(1);
 504                 }
 505         }
 506 #endif
 507
 508         while( (opt = getopt(argc, argv, "fSC:K:p:s:h:c:l:L:d:r:m:x:t:T:")) > 0 )
 509         {
 510                 switch(opt)
 511                 {
 512                         /* [addr:]port */
 513                         case 'p':
 514                         case 's':
 515                                 if( (port = strrchr(optarg, ':')) != NULL )
 516                                 {
 517                                         if( (optarg[0] == '[') && (port > optarg) && (port[-1] == ']') )
 518                                                 memcpy(bind, optarg + 1,
 519                                                         min(sizeof(bind), (int)(port - optarg) - 2));
 520                                         else
 521                                                 memcpy(bind, optarg,
 522                                                         min(sizeof(bind), (int)(port - optarg)));
 523
 524                                         port++;
 525                                 }
 526                                 else
 527                                 {
 528                                         port = optarg;
 529                                 }
 530
 531 #ifdef HAVE_TLS
 532                                 if( opt == 's' )
 533                                 {
 534                                         if( !conf.tls )
 535                                         {
 536                                                 fprintf(stderr,
 537                                                         "Notice: TLS support is disabled, "
 538                                                         "ignoring '-s %s'\n", optarg
 539                                                 );
 540                                                 continue;
 541                                         }
 542
 543                                         tls = 1;
 544                                 }
 545 #endif
 546
 547                                 /* bind sockets */
 548                                 bound += uh_socket_bind(
 549                                         &serv_fds, &max_fd, bind[0] ? bind : NULL, port,
 550                                         &hints, (opt == 's'), &conf
 551                                 );
 552
 553                                 memset(bind, 0, sizeof(bind));
 554                                 break;
 555
 556 #ifdef HAVE_TLS
 557                         /* certificate */
 558                         case 'C':
 559                                 if( conf.tls )
 560                                 {
 561                                         if( conf.tls_cert(conf.tls, optarg) < 1 )
 562                                         {
 563                                                 fprintf(stderr,
 564                                                         "Error: Invalid certificate file given\n");
 565                                                 exit(1);
 566                                         }
 567
 568                                         keys++;
 569                                 }
 570
 571                                 break;
 572
 573                         /* key */
 574                         case 'K':
 575                                 if( conf.tls )
 576                                 {
 577                                         if( conf.tls_key(conf.tls, optarg) < 1 )
 578                                         {
 579                                                 fprintf(stderr,
 580                                                         "Error: Invalid private key file given\n");
 581                                                 exit(1);
 582                                         }
 583
 584                                         keys++;
 585                                 }
 586
 587                                 break;
 588 #endif
 589
 590                         /* docroot */
 591                         case 'h':
 592                                 if( ! realpath(optarg, conf.docroot) )
 593                                 {
 594                                         fprintf(stderr, "Error: Invalid directory %s: %s\n",
 595                                                 optarg, strerror(errno));
 596                                         exit(1);
 597                                 }
 598                                 break;
 599
 600                         /* don't follow symlinks */
 601                         case 'S':
 602                                 conf.no_symlinks = 1;
 603                                 break;
 604
 605 #ifdef HAVE_CGI
 606                         /* cgi prefix */
 607                         case 'x':
 608                                 conf.cgi_prefix = optarg;
 609                                 break;
 610 #endif
 611
 612 #ifdef HAVE_LUA
 613                         /* lua prefix */
 614                         case 'l':
 615                                 conf.lua_prefix = optarg;
 616                                 break;
 617
 618                         /* lua handler */
 619                         case 'L':
 620                                 conf.lua_handler = optarg;
 621                                 break;
 622 #endif
 623
 624 #if defined(HAVE_CGI) || defined(HAVE_LUA)
 625                         /* script timeout */
 626                         case 't':
 627                                 conf.script_timeout = atoi(optarg);
 628                                 break;
 629 #endif
 630
 631                         /* network timeout */
 632                         case 'T':
 633                                 conf.network_timeout = atoi(optarg);
 634                                 break;
 635
 636                         /* no fork */
 637                         case 'f':
 638                                 nofork = 1;
 639                                 break;
 640
 641                         /* urldecode */
 642                         case 'd':
 643                                 if( (port = malloc(strlen(optarg)+1)) != NULL )
 644                                 {
 645                                         memset(port, 0, strlen(optarg)+1);
 646                                         uh_urldecode(port, strlen(optarg), optarg, strlen(optarg));
 647                                         printf("%s", port);
 648                                         free(port);
 649                                         exit(0);
 650                                 }
 651                                 break;
 652
 653                         /* basic auth realm */
 654                         case 'r':
 655                                 conf.realm = optarg;
 656                                 break;
 657
 658                         /* md5 crypt */
 659                         case 'm':
 660                                 printf("%s\n", crypt(optarg, "$1$"));
 661                                 exit(0);
 662                                 break;
 663
 664                         /* config file */
 665                         case 'c':
 666                                 conf.file = optarg;
 667                                 break;
 668
 669                         default:
 670                                 fprintf(stderr,
 671                                         "Usage: %s -p [addr:]port [-h docroot]\n"
 672                                         "       -f              Do not fork to background\n"
 673                                         "       -c file         Configuration file, default is '/etc/httpd.conf'\n"
 674                                         "       -p [addr:]port  Bind to specified address and port, multiple allowed\n"
 675 #ifdef HAVE_TLS
 676                                         "       -s [addr:]port  Like -p but provide HTTPS on this port\n"
 677                                         "       -C file         ASN.1 server certificate file\n"
 678                                         "       -K file         ASN.1 server private key file\n"
 679 #endif
 680                                         "       -h directory    Specify the document root, default is '.'\n"
 681                                         "       -S              Do not follow symbolic links outside of the docroot\n"
 682 #ifdef HAVE_LUA
 683                                         "       -l string       URL prefix for Lua handler, default is '/lua'\n"
 684                                         "       -L file         Lua handler script, omit to disable Lua\n"
 685 #endif
 686 #ifdef HAVE_CGI
 687                                         "       -x string       URL prefix for CGI handler, default is '/cgi-bin'\n"
 688 #endif
 689 #if defined(HAVE_CGI) || defined(HAVE_LUA)
 690                                         "       -t seconds      CGI and Lua script timeout in seconds, default is 60\n"
 691 #endif
 692                                         "       -T seconds      Network timeout in seconds, default is 30\n"
 693                                         "       -d string       URL decode given string\n"
 694                                         "       -r string       Specify basic auth realm\n"
 695                                         "       -m string       MD5 crypt given string\n"
 696                                         "\n", argv[0]
 697                                 );
 698
 699                                 exit(1);
 700                 }
 701         }
 702
 703 #ifdef HAVE_TLS
 704         if( (tls == 1) && (keys < 2) )
 705         {
 706                 fprintf(stderr, "Error: Missing private key or certificate file\n");
 707                 exit(1);
 708         }
 709 #endif
 710
 711         if( bound < 1 )
 712         {
 713                 fprintf(stderr, "Error: No sockets bound, unable to continue\n");
 714                 exit(1);
 715         }
 716
 717         /* default docroot */
 718         if( !conf.docroot[0] && !realpath(".", conf.docroot) )
 719         {
 720                 fprintf(stderr, "Error: Can not determine default document root: %s\n",
 721                         strerror(errno));
 722                 exit(1);
 723         }
 724
 725         /* default realm */
 726         if( ! conf.realm )
 727                 conf.realm = "Protected Area";
 728
 729         /* config file */
 730         uh_config_parse(conf.file);
 731
 732         /* default network timeout */
 733         if( conf.network_timeout <= 0 )
 734                 conf.network_timeout = 30;
 735
 736 #if defined(HAVE_CGI) || defined(HAVE_LUA)
 737         /* default script timeout */
 738         if( conf.script_timeout <= 0 )
 739                 conf.script_timeout = 60;
 740 #endif
 741
 742 #ifdef HAVE_CGI
 743         /* default cgi prefix */
 744         if( ! conf.cgi_prefix )
 745                 conf.cgi_prefix = "/cgi-bin";
 746 #endif
 747
 748 #ifdef HAVE_LUA
 749         /* load Lua plugin */
 750         if( ! (lib = dlopen("uhttpd_lua.so", RTLD_LAZY | RTLD_GLOBAL)) )
 751         {
 752                 fprintf(stderr,
 753                         "Notice: Unable to load Lua plugin - disabling Lua support! "
 754                         "(Reason: %s)\n", dlerror()
 755                 );
 756         }
 757         else
 758         {
 759                 /* resolve functions */
 760                 if( !(conf.lua_init    = dlsym(lib, "uh_lua_init"))    ||
 761                     !(conf.lua_close   = dlsym(lib, "uh_lua_close"))   ||
 762                     !(conf.lua_request = dlsym(lib, "uh_lua_request"))
 763                 ) {
 764                         fprintf(stderr,
 765                                 "Error: Failed to lookup required symbols "
 766                                 "in Lua plugin: %s\n", dlerror()
 767                         );
 768                         exit(1);
 769                 }
 770
 771                 /* init Lua runtime if handler is specified */
 772                 if( conf.lua_handler )
 773                 {
 774                         /* default lua prefix */
 775                         if( ! conf.lua_prefix )
 776                                 conf.lua_prefix = "/lua";
 777
 778                         L = conf.lua_init(conf.lua_handler);
 779                 }
 780         }
 781 #endif
 782
 783         /* fork (if not disabled) */
 784         if( ! nofork )
 785         {
 786                 switch( fork() )
 787                 {
 788                         case -1:
 789                                 perror("fork()");
 790                                 exit(1);
 791
 792                         case 0:
 793                                 /* daemon setup */
 794                                 if( chdir("/") )
 795                                         perror("chdir()");
 796
 797                                 if( (cur_fd = open("/dev/null", O_WRONLY)) > -1 )
 798                                         dup2(cur_fd, 0);
 799
 800                                 if( (cur_fd = open("/dev/null", O_RDONLY)) > -1 )
 801                                         dup2(cur_fd, 1);
 802
 803                                 if( (cur_fd = open("/dev/null", O_RDONLY)) > -1 )
 804                                         dup2(cur_fd, 2);
 805
 806                                 break;
 807
 808                         default:
 809                                 exit(0);
 810                 }
 811         }
 812
 813         /* backup server descriptor set */
 814         used_fds = serv_fds;
 815
 816         /* loop */
 817         while(run)
 818         {
 819                 /* create a working copy of the used fd set */
 820                 read_fds = used_fds;
 821
 822                 /* sleep until socket activity */
 823                 if( select(max_fd + 1, &read_fds, NULL, NULL, NULL) == -1 )
 824                 {
 825                         perror("select()");
 826                         exit(1);
 827                 }
 828
 829                 /* run through the existing connections looking for data to be read */
 830                 for( cur_fd = 0; cur_fd <= max_fd; cur_fd++ )
 831                 {
 832                         /* is a socket managed by us */
 833                         if( FD_ISSET(cur_fd, &read_fds) )
 834                         {
 835                                 /* is one of our listen sockets */
 836                                 if( FD_ISSET(cur_fd, &serv_fds) )
 837                                 {
 838                                         /* handle new connections */
 839                                         if( (new_fd = accept(cur_fd, NULL, 0)) != -1 )
 840                                         {
 841                                                 /* add to global client list */
 842                                                 if( (cl = uh_client_add(new_fd, uh_listener_lookup(cur_fd))) != NULL )
 843                                                 {
 844 #ifdef HAVE_TLS
 845                                                         /* setup client tls context */
 846                                                         if( conf.tls )
 847                                                                 conf.tls_accept(cl);
 848 #endif
 849
 850                                                         /* add client socket to global fdset */
 851                                                         FD_SET(new_fd, &used_fds);
 852                                                         fd_cloexec(new_fd);
 853                                                         max_fd = max(max_fd, new_fd);
 854                                                 }
 855
 856                                                 /* insufficient resources */
 857                                                 else
 858                                                 {
 859                                                         fprintf(stderr,
 860                                                                 "uh_client_add(): Can not manage more than "
 861                                                                 "%i client sockets, connection dropped\n",
 862                                                                 UH_LIMIT_CLIENTS
 863                                                         );
 864
 865                                                         close(new_fd);
 866                                                 }
 867                                         }
 868                                 }
 869
 870                                 /* is a client socket */
 871                                 else
 872                                 {
 873                                         if( ! (cl = uh_client_lookup(cur_fd)) )
 874                                         {
 875                                                 /* this should not happen! */
 876                                                 fprintf(stderr,
 877                                                         "uh_client_lookup(): No entry for fd %i!\n",
 878                                                         cur_fd);
 879
 880                                                 goto cleanup;
 881                                         }
 882
 883                                         /* parse message header */
 884                                         if( (req = uh_http_header_recv(cl)) != NULL )
 885                                         {
 886 #ifdef HAVE_LUA
 887                                                 /* Lua request? */
 888                                                 if( L && uh_path_match(conf.lua_prefix, req->url) )
 889                                                 {
 890                                                         conf.lua_request(cl, req, L);
 891                                                 }
 892                                                 else
 893 #endif
 894                                                 /* dispatch request */
 895                                                 if( (pin = uh_path_lookup(cl, req->url)) != NULL )
 896                                                 {
 897                                                         /* auth ok? */
 898                                                         if( uh_auth_check(cl, req, pin) )
 899                                                         {
 900 #ifdef HAVE_CGI
 901                                                                 if( uh_path_match(conf.cgi_prefix, pin->name) )
 902                                                                 {
 903                                                                         uh_cgi_request(cl, req, pin);
 904                                                                 }
 905                                                                 else
 906 #endif
 907                                                                 {
 908                                                                         uh_file_request(cl, req, pin);
 909                                                                 }
 910                                                         }
 911                                                 }
 912
 913                                                 /* 404 */
 914                                                 else
 915                                                 {
 916                                                         uh_http_sendhf(cl, 404, "Not Found",
 917                                                                 "No such file or directory");
 918                                                 }
 919                                         }
 920
 921                                         /* 400 */
 922                                         else
 923                                         {
 924                                                 uh_http_sendhf(cl, 400, "Bad Request",
 925                                                         "Malformed request received");
 926                                         }
 927
 928 #ifdef HAVE_TLS
 929                                         /* free client tls context */
 930                                         if( conf.tls )
 931                                                 conf.tls_close(cl);
 932 #endif
 933
 934                                         cleanup:
 935
 936                                         /* close client socket */
 937                                         close(cur_fd);
 938                                         FD_CLR(cur_fd, &used_fds);
 939
 940                                         /* remove from global client list */
 941                                         uh_client_remove(cur_fd);
 942                                 }
 943                         }
 944                 }
 945         }
 946
 947 #ifdef HAVE_LUA
 948         /* destroy the Lua state */
 949         if( L != NULL )
 950                 conf.lua_close(L);
 951 #endif
 952
 953         return 0;
 954 }
 955