uhttpd: finish basic auth support, read realms from /etc/httpd.conf
[project/luci.git] / contrib / package / uhttpd / src / uhttpd.c
1 /*
2  * uhttpd - Tiny non-forking 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_config_parse(const char *path)
46 {
47         FILE *c;
48         char line[512];
49         char *user = NULL;
50         char *pass = NULL;
51         char *eol  = NULL;
52
53         if( (c = fopen(path ? path : "/etc/httpd.conf", "r")) != NULL )
54         {
55                 memset(line, 0, sizeof(line));
56
57                 while( fgets(line, sizeof(line) - 1, c) )
58                 {
59                         if( (line[0] == '/') && (strchr(line, ':') != NULL) )
60                         {
61                                 if( !(user = strchr(line, ':')) || (*user++ = 0) ||
62                                     !(pass = strchr(user, ':')) || (*pass++ = 0) ||
63                                         !(eol = strchr(pass, '\n')) || (*eol++  = 0) )
64                                                 continue;
65
66                                 if( !uh_auth_add(line, user, pass) )
67                                 {
68                                         fprintf(stderr,
69                                                 "Can not manage more than %i basic auth realms, "
70                                                 "will skip the rest\n", UH_LIMIT_AUTHREALMS
71                                         );
72
73                                         break;
74                                 } 
75                         }
76                 }
77
78                 fclose(c);
79         }
80 }
81
82 static int uh_socket_bind(
83         fd_set *serv_fds, int *max_fd, const char *host, const char *port,
84         struct addrinfo *hints, int do_tls, struct config *conf
85 ) {
86         int sock = -1;
87         int yes = 1;
88         int status;
89         int bound = 0;
90
91         struct listener *l = NULL;
92         struct addrinfo *addrs = NULL, *p = NULL;
93
94         if( (status = getaddrinfo(host, port, hints, &addrs)) != 0 )
95         {
96                 fprintf(stderr, "getaddrinfo(): %s\n", gai_strerror(status));
97         }
98
99         /* try to bind a new socket to each found address */
100         for( p = addrs; p; p = p->ai_next )
101         {
102                 /* get the socket */
103                 if( (sock = socket(p->ai_family, p->ai_socktype, p->ai_protocol)) == -1 )
104                 {
105                         perror("socket()");
106                         goto error;
107                 }
108
109                 /* "address already in use" */
110                 if( setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(yes)) == -1 )
111                 {
112                         perror("setsockopt()");
113                         goto error;
114                 }
115
116                 /* required to get parallel v4 + v6 working */
117                 if( p->ai_family == AF_INET6 )
118                 {
119                         if( setsockopt(sock, IPPROTO_IPV6, IPV6_V6ONLY, &yes, sizeof(yes)) == -1 )
120                         {
121                                 perror("setsockopt()");
122                                 goto error;
123                         }
124                 }
125
126                 /* bind */
127                 if( bind(sock, p->ai_addr, p->ai_addrlen) == -1 )
128                 {
129                         perror("bind()");
130                         goto error;
131                 }
132
133                 /* listen */
134                 if( listen(sock, UH_LIMIT_CLIENTS) == -1 )
135                 {
136                         perror("listen()");
137                         goto error;
138                 }
139
140                 /* add listener to global list */
141                 if( ! (l = uh_listener_add(sock, conf)) )
142                 {
143                         fprintf(stderr,
144                                 "uh_listener_add(): Can not create more than "
145                                 "%i listen sockets\n", UH_LIMIT_LISTENERS
146                         );
147
148                         goto error;
149                 }
150
151 #ifdef HAVE_TLS
152                 /* init TLS */
153                 l->tls = do_tls ? conf->tls : NULL;
154 #endif
155
156                 /* add socket to server fd set */
157                 FD_SET(sock, serv_fds);
158                 *max_fd = max(*max_fd, sock);
159
160                 bound++;
161                 continue;
162
163                 error:
164                 if( sock > 0 )
165                         close(sock);
166         }
167
168         freeaddrinfo(addrs);
169
170         return bound;
171 }
172
173 static struct http_request * uh_http_header_parse(struct client *cl, char *buffer, int buflen)
174 {
175         char *method  = &buffer[0];
176         char *path    = NULL;
177         char *version = NULL;
178
179         char *headers = NULL;
180         char *hdrname = NULL;
181         char *hdrdata = NULL;
182
183         int i;
184         int hdrcount = 0;
185
186         static struct http_request req;
187
188         memset(&req, 0, sizeof(req));
189
190
191         /* terminate initial header line */
192         if( (headers = strfind(buffer, buflen, "\r\n", 2)) != NULL )
193         {
194                 buffer[buflen-1] = 0;
195
196                 *headers++ = 0;
197                 *headers++ = 0;
198
199                 /* find request path */
200                 if( (path = strchr(buffer, ' ')) != NULL )
201                         *path++ = 0;
202
203                 /* find http version */
204                 if( (path != NULL) && ((version = strchr(path, ' ')) != NULL) )
205                         *version++ = 0;
206
207
208                 /* check method */
209                 if( strcmp(method, "GET") && strcmp(method, "HEAD") && strcmp(method, "POST") )
210                 {
211                         /* invalid method */
212                         uh_http_response(cl, 405, "Method Not Allowed");
213                         return NULL;
214                 }
215                 else
216                 {
217                         switch(method[0])
218                         {
219                                 case 'G':
220                                         req.method = UH_HTTP_MSG_GET;
221                                         break;
222
223                                 case 'H':
224                                         req.method = UH_HTTP_MSG_HEAD;
225                                         break;
226
227                                 case 'P':
228                                         req.method = UH_HTTP_MSG_POST;
229                                         break;
230                         }
231                 }
232
233                 /* check path */
234                 if( !path || !strlen(path) )
235                 {
236                         /* malformed request */
237                         uh_http_response(cl, 400, "Bad Request");
238                         return NULL;
239                 }
240                 else
241                 {
242                         req.url = path;
243                 }
244
245                 /* check version */
246                 if( strcmp(version, "HTTP/0.9") && strcmp(version, "HTTP/1.0") && strcmp(version, "HTTP/1.1") )
247                 {
248                         /* unsupported version */
249                         uh_http_response(cl, 400, "Bad Request");
250                         return NULL;
251                 }
252                 else
253                 {
254                         req.version = strtof(&version[5], NULL);
255                 }
256
257
258                 /* process header fields */
259                 for( i = (int)(headers - buffer); i < buflen; i++ )
260                 {
261                         /* found eol and have name + value, push out header tuple */
262                         if( hdrname && hdrdata && (buffer[i] == '\r' || buffer[i] == '\n') )
263                         {
264                                 buffer[i] = 0;
265
266                                 /* store */
267                                 if( (hdrcount + 1) < array_size(req.headers) )
268                                 {
269                                         req.headers[hdrcount++] = hdrname;
270                                         req.headers[hdrcount++] = hdrdata;
271
272                                         hdrname = hdrdata = NULL;
273                                 }
274
275                                 /* too large */
276                                 else
277                                 {
278                                         uh_http_response(cl, 413, "Request Entity Too Large");
279                                         return NULL;
280                                 }
281                         }
282
283                         /* have name but no value and found a colon, start of value */
284                         else if( hdrname && !hdrdata && ((i+2) < buflen) &&
285                                 (buffer[i] == ':') && (buffer[i+1] == ' ')
286                         ) {
287                                 buffer[i] = 0;
288                                 hdrdata = &buffer[i+2];
289                         }
290
291                         /* have no name and found [A-Z], start of name */
292                         else if( !hdrname && isalpha(buffer[i]) && isupper(buffer[i]) )
293                         {
294                                 hdrname = &buffer[i];
295                         }
296                 }
297
298                 /* valid enough */
299                 return &req;
300         }
301
302         /* Malformed request */
303         uh_http_response(cl, 400, "Bad Request");
304         return NULL;
305 }
306
307
308 static struct http_request * uh_http_header_recv(struct client *cl)
309 {
310         static char buffer[UH_LIMIT_MSGHEAD];
311         char *bufptr = &buffer[0];
312         char *idxptr = NULL;
313
314         struct timeval timeout;
315
316         fd_set reader;
317
318         ssize_t blen = sizeof(buffer)-1;
319         ssize_t rlen = 0;
320
321
322         memset(buffer, 0, sizeof(buffer));
323
324         while( blen > 0 )
325         {
326                 FD_ZERO(&reader);
327                 FD_SET(cl->socket, &reader);
328
329                 /* fail after 0.1s */
330                 timeout.tv_sec  = 0;
331                 timeout.tv_usec = 100000;
332
333                 /* check whether fd is readable */
334                 if( select(cl->socket + 1, &reader, NULL, NULL, &timeout) > 0 )
335                 {
336                         /* receive data */
337                         rlen = uh_tcp_peek(cl, bufptr, blen);
338
339                         if( rlen > 0 )
340                         {
341                                 if( (idxptr = strfind(buffer, sizeof(buffer), "\r\n\r\n", 4)) )
342                                 {
343                                         blen -= uh_tcp_recv(cl, bufptr, (int)(idxptr - bufptr) + 4);
344
345                                         /* header read complete ... */
346                                         return uh_http_header_parse(cl, buffer, sizeof(buffer) - blen - 1);
347                                 }
348                                 else
349                                 {
350                                         rlen = uh_tcp_recv(cl, bufptr, rlen);
351                                         blen -= rlen;
352                                         bufptr += rlen;
353                                 }
354                         }
355                         else
356                         {
357                                 /* invalid request (unexpected eof/timeout) */
358                                 uh_http_response(cl, 408, "Request Timeout");
359                                 return NULL;
360                         }
361                 }
362                 else
363                 {
364                         /* invalid request (unexpected eof/timeout) */
365                         uh_http_response(cl, 408, "Request Timeout");
366                         return NULL;
367                 }
368         }
369
370         /* request entity too large */
371         uh_http_response(cl, 413, "Request Entity Too Large");
372         return NULL;
373 }
374
375
376 int main (int argc, char **argv)
377 {
378 #ifdef HAVE_LUA
379         /* Lua runtime */
380         lua_State *L = NULL;
381 #endif
382
383         /* master file descriptor list */
384         fd_set used_fds, serv_fds, read_fds;
385
386         /* working structs */
387         struct addrinfo hints;
388         struct http_request *req;
389         struct path_info *pin;
390         struct client *cl;
391         struct sigaction sa;
392         struct config conf;
393
394         /* maximum file descriptor number */
395         int new_fd, cur_fd, max_fd = 0;
396
397         int tls = 0;
398         int keys = 0;
399         int bound = 0;
400         int nofork = 0;
401
402         /* args */
403         char opt;
404         char bind[128];
405         char *port = NULL;
406
407         /* clear the master and temp sets */
408         FD_ZERO(&used_fds);
409         FD_ZERO(&serv_fds);
410         FD_ZERO(&read_fds);
411
412         /* handle SIGPIPE, SIGCHILD */
413         sa.sa_handler = SIG_IGN;
414         sigaction(SIGPIPE, &sa, NULL);
415         sigaction(SIGCHLD, &sa, NULL);
416
417         sa.sa_handler = uh_sigterm;
418         sigaction(SIGINT,  &sa, NULL);
419         sigaction(SIGTERM, &sa, NULL);
420
421         /* prepare addrinfo hints */
422         memset(&hints, 0, sizeof(hints));
423         hints.ai_family   = AF_UNSPEC;
424         hints.ai_socktype = SOCK_STREAM;
425         hints.ai_flags    = AI_PASSIVE;
426
427         /* parse args */
428         memset(&conf, 0, sizeof(conf));
429         memset(bind, 0, sizeof(bind));
430
431 #ifdef HAVE_TLS
432         /* init SSL context */
433         if( ! (conf.tls = uh_tls_ctx_init()) )
434         {
435                 fprintf(stderr, "Failed to initalize SSL context\n");
436                 exit(1);
437         }
438 #endif
439
440         while( (opt = getopt(argc, argv, "fC:K:p:s:h:c:l:L:d:r:m:x:")) > 0 )
441         {
442                 switch(opt)
443                 {
444                         /* [addr:]port */
445                         case 'p':
446                         case 's':
447                                 if( (port = strrchr(optarg, ':')) != NULL )
448                                 {
449                                         if( (optarg[0] == '[') && (port > optarg) && (port[-1] == ']') )
450                                                 memcpy(bind, optarg + 1,
451                                                         min(sizeof(bind), (int)(port - optarg) - 2));
452                                         else
453                                                 memcpy(bind, optarg,
454                                                         min(sizeof(bind), (int)(port - optarg)));
455
456                                         port++;
457                                 }
458                                 else
459                                 {
460                                         port = optarg;
461                                 }
462
463                                 if( opt == 's' )
464                                         tls = 1;
465
466                                 /* bind sockets */
467                                 bound += uh_socket_bind(
468                                         &serv_fds, &max_fd, bind[0] ? bind : NULL, port,
469                                         &hints, tls, &conf
470                                 );
471
472                                 break;
473
474 #ifdef HAVE_TLS
475                         /* certificate */
476                         case 'C':
477                                 if( SSL_CTX_use_certificate_file(conf.tls, optarg, SSL_FILETYPE_ASN1) < 1 )
478                                 {
479                                         fprintf(stderr, "Invalid certificate file given\n");
480                                         exit(1);
481                                 }
482
483                                 keys++;
484                                 break;
485
486                         /* key */
487                         case 'K':
488                                 if( SSL_CTX_use_PrivateKey_file(conf.tls, optarg, SSL_FILETYPE_ASN1) < 1 )
489                                 {
490                                         fprintf(stderr, "Invalid private key file given\n");
491                                         exit(1);
492                                 }
493
494                                 keys++;
495                                 break;
496 #endif
497
498                         /* docroot */
499                         case 'h':
500                                 if( ! realpath(optarg, conf.docroot) )
501                                 {
502                                         fprintf(stderr, "Invalid directory %s: %s\n", optarg, strerror(errno));
503                                         exit(1);
504                                 }
505                                 break;
506
507 #ifdef HAVE_CGI
508                         /* cgi prefix */
509                         case 'x':
510                                 conf.cgi_prefix = optarg;
511                                 break;
512 #endif
513
514 #ifdef HAVE_LUA
515                         /* lua prefix */
516                         case 'l':
517                                 conf.lua_prefix = optarg;
518                                 break;
519
520                         /* lua handler */
521                         case 'L':
522                                 conf.lua_handler = optarg;
523                                 break;
524 #endif
525
526                         /* no fork */
527                         case 'f':
528                                 nofork = 1;
529                                 break;
530
531                         /* urldecode */
532                         case 'd':
533                                 if( (port = malloc(strlen(optarg)+1)) != NULL )
534                                 {
535                                         memset(port, 0, strlen(optarg)+1);
536                                         uh_urldecode(port, strlen(optarg), optarg, strlen(optarg));
537                                         printf("%s", port);
538                                         free(port);
539                                         exit(0);
540                                 }
541                                 break;
542
543                         /* basic auth realm */
544                         case 'r':
545                                 conf.realm = optarg;
546                                 break;
547
548                         /* md5 crypt */
549                         case 'm':
550                                 printf("%s\n", crypt(optarg, "$1$"));
551                                 exit(0);
552                                 break;
553
554                         /* config file */
555                         case 'c':
556                                 conf.file = optarg;
557                                 break;
558
559                         default:
560                                 fprintf(stderr,
561                                         "Usage: %s -p [addr:]port [-h docroot]\n"
562                                         "       -f              Do not fork to background\n"
563                                         "       -c file         Configuration file, default is '/etc/httpd.conf'\n"
564                                         "       -p [addr:]port  Bind to specified address and port, multiple allowed\n"
565 #ifdef HAVE_TLS
566                                         "       -s [addr:]port  Like -p but provide HTTPS on this port\n"
567                                         "       -C file         ASN.1 server certificate file\n"
568                                         "       -K file         ASN.1 server private key file\n"
569 #endif
570                                         "       -h directory    Specify the document root, default is '.'\n"
571 #ifdef HAVE_LUA
572                                         "       -l string       URL prefix for Lua handler, default is '/lua'\n"
573                                         "       -L file         Lua handler script, omit to disable Lua\n"
574 #endif
575 #ifdef HAVE_CGI
576                                         "       -x string       URL prefix for CGI handler, default is '/cgi-bin'\n"
577 #endif
578                                         "       -d string       URL decode given string\n"
579                                         "       -r string       Specify basic auth realm\n"
580                                         "       -m string       MD5 crypt given string\n"
581                                         "\n", argv[0]
582                                 );
583
584                                 exit(1);
585                 }
586         }
587
588 #ifdef HAVE_TLS
589         if( (tls == 1) && (keys < 2) )
590         {
591                 fprintf(stderr, "Missing private key or certificate file\n");
592                 exit(1);
593         }
594 #endif
595
596         if( bound < 1 )
597         {
598                 fprintf(stderr, "No sockets bound, unable to continue\n");
599                 exit(1);
600         }
601
602         /* default docroot */
603         if( !conf.docroot[0] && !realpath(".", conf.docroot) )
604         {
605                 fprintf(stderr, "Can not determine default document root: %s\n",
606                         strerror(errno));
607                 exit(1);
608         }
609
610         /* default realm */
611         if( ! conf.realm )
612                 conf.realm = "Protected Area";
613
614         /* config file */
615         uh_config_parse(conf.file);
616
617 #ifdef HAVE_CGI
618         /* default cgi prefix */
619         if( ! conf.cgi_prefix )
620                 conf.cgi_prefix = "/cgi-bin";
621 #endif
622
623 #ifdef HAVE_LUA
624         /* init Lua runtime if handler is specified */
625         if( conf.lua_handler )
626         {
627                 /* default lua prefix */
628                 if( ! conf.lua_prefix )
629                         conf.lua_prefix = "/lua";
630
631                 L = uh_lua_init(conf.lua_handler);
632         }
633 #endif
634
635         /* fork (if not disabled) */
636         if( ! nofork )
637         {
638                 switch( fork() )
639                 {
640                         case -1:
641                                 perror("fork()");
642                                 exit(1);
643
644                         case 0:
645                                 /* daemon setup */
646                                 if( chdir("/") )
647                                         perror("chdir()");
648
649                                 if( (cur_fd = open("/dev/null", O_WRONLY)) > -1 )
650                                         dup2(cur_fd, 0);
651
652                                 if( (cur_fd = open("/dev/null", O_RDONLY)) > -1 )
653                                         dup2(cur_fd, 1);
654
655                                 if( (cur_fd = open("/dev/null", O_RDONLY)) > -1 )
656                                         dup2(cur_fd, 2);
657
658                                 break;
659
660                         default:
661                                 exit(0);
662                 }
663         }
664
665         /* backup server descriptor set */
666         used_fds = serv_fds;
667
668         /* loop */
669         while(run)
670         {
671                 /* create a working copy of the used fd set */
672                 read_fds = used_fds;
673
674                 /* sleep until socket activity */
675                 if( select(max_fd + 1, &read_fds, NULL, NULL, NULL) == -1 )
676                 {
677                         perror("select()");
678                         exit(1);
679                 }
680
681                 /* run through the existing connections looking for data to be read */
682                 for( cur_fd = 0; cur_fd <= max_fd; cur_fd++ )
683                 {
684                         /* is a socket managed by us */
685                         if( FD_ISSET(cur_fd, &read_fds) )
686                         {
687                                 /* is one of our listen sockets */
688                                 if( FD_ISSET(cur_fd, &serv_fds) )
689                                 {
690                                         /* handle new connections */
691                                         if( (new_fd = accept(cur_fd, NULL, 0)) != -1 )
692                                         {
693                                                 /* add to global client list */
694                                                 if( (cl = uh_client_add(new_fd, uh_listener_lookup(cur_fd))) != NULL )
695                                                 {
696 #ifdef HAVE_TLS
697                                                         /* setup client tls context */
698                                                         uh_tls_client_accept(cl);
699 #endif
700
701                                                         /* add client socket to global fdset */
702                                                         FD_SET(new_fd, &used_fds);
703                                                         max_fd = max(max_fd, new_fd);
704                                                 }
705
706                                                 /* insufficient resources */
707                                                 else
708                                                 {
709                                                         fprintf(stderr,
710                                                                 "uh_client_add(): Can not manage more than "
711                                                                 "%i client sockets, connection dropped\n",
712                                                                 UH_LIMIT_CLIENTS
713                                                         );
714
715                                                         close(new_fd);
716                                                 }
717                                         }
718                                 }
719
720                                 /* is a client socket */
721                                 else
722                                 {
723                                         if( ! (cl = uh_client_lookup(cur_fd)) )
724                                         {
725                                                 /* this should not happen! */
726                                                 fprintf(stderr,
727                                                         "uh_client_lookup(): No entry for fd %i!\n",
728                                                         cur_fd);
729
730                                                 goto cleanup;
731                                         }
732
733                                         /* parse message header */
734                                         if( (req = uh_http_header_recv(cl)) != NULL )
735                                         {
736 #ifdef HAVE_LUA
737                                                 /* Lua request? */
738                                                 if( L && strstr(req->url, conf.lua_prefix) == req->url )
739                                                 {
740                                                         uh_lua_request(cl, req, L);
741                                                 }
742                                                 else
743 #endif
744                                                 /* dispatch request */
745                                                 if( (pin = uh_path_lookup(cl, req->url)) != NULL )
746                                                 {
747                                                         /* auth ok? */
748                                                         if( uh_auth_check(cl, req, pin) )
749                                                         {
750 #ifdef HAVE_CGI
751                                                                 if( strstr(pin->name, conf.cgi_prefix) == pin->name )
752                                                                 {
753                                                                         uh_cgi_request(cl, req, pin);
754                                                                 }
755                                                                 else
756 #endif
757                                                                 {
758                                                                         uh_file_request(cl, req, pin);
759                                                                 }
760                                                         }
761                                                 }
762
763                                                 /* 404 */
764                                                 else
765                                                 {
766                                                         uh_http_sendhf(cl, 404, "Not Found",
767                                                                 "No such file or directory");
768                                                 }
769                                         }
770
771                                         /* 400 */
772                                         else
773                                         {
774                                                 uh_http_sendhf(cl, 400, "Bad Request",
775                                                         "Malformed request received");
776                                         }
777
778 #ifdef HAVE_TLS
779                                         /* free client tls context */
780                                         uh_tls_client_close(cl);
781 #endif
782
783                                         cleanup:
784
785                                         /* close client socket */
786                                         close(cur_fd);
787                                         FD_CLR(cur_fd, &used_fds);
788
789                                         /* remove from global client list */
790                                         uh_client_remove(cur_fd);
791                                 }
792                         }
793                 }
794         }
795
796 #ifdef HAVE_LUA
797         /* destroy the Lua state */
798         if( L != NULL )
799                 lua_close(L);
800 #endif
801
802         return 0;
803 }
804