07dcd71ff830030ff3ee12d3c1c5f7467bfd55ee
[oweals/busybox.git] / networking / httpd.c
1 /* vi: set sw=4 ts=4: */
2 /*
3  * httpd implementation for busybox
4  *
5  * Copyright (C) 2002,2003 Glenn Engel <glenne@engel.org>
6  * Copyright (C) 2003-2006 Vladimir Oleynik <dzo@simtreas.ru>
7  *
8  * simplify patch stolen from libbb without using strdup
9  *
10  * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
11  *
12  *****************************************************************************
13  *
14  * Typical usage:
15  *   for non root user
16  * httpd -p 8080 -h $HOME/public_html
17  *   or for daemon start from rc script with uid=0:
18  * httpd -u www
19  * This is equivalent if www user have uid=80 to
20  * httpd -p 80 -u 80 -h /www -c /etc/httpd.conf -r "Web Server Authentication"
21  *
22  *
23  * When a url starts by "/cgi-bin/" it is assumed to be a cgi script.  The
24  * server changes directory to the location of the script and executes it
25  * after setting QUERY_STRING and other environment variables.
26  *
27  * Doc:
28  * "CGI Environment Variables": http://hoohoo.ncsa.uiuc.edu/cgi/env.html
29  *
30  * The applet can also be invoked as a url arg decoder and html text encoder
31  * as follows:
32  *  foo=`httpd -d $foo`           # decode "Hello%20World" as "Hello World"
33  *  bar=`httpd -e "<Hello World>"`  # encode as "&#60Hello&#32World&#62"
34  * Note that url encoding for arguments is not the same as html encoding for
35  * presentation.  -d decodes an url-encoded argument while -e encodes in html
36  * for page display.
37  *
38  * httpd.conf has the following format:
39  *
40  * H:/serverroot     # define the server root. It will override -h
41  * A:172.20.         # Allow address from 172.20.0.0/16
42  * A:10.0.0.0/25     # Allow any address from 10.0.0.0-10.0.0.127
43  * A:10.0.0.0/255.255.255.128  # Allow any address that previous set
44  * A:127.0.0.1       # Allow local loopback connections
45  * D:*               # Deny from other IP connections
46  * E404:/path/e404.html # /path/e404.html is the 404 (not found) error page
47  * I:index.html      # Show index.html when a directory is requested
48  *
49  * P:/url:[http://]hostname[:port]/new/path
50  *                   # When /urlXXXXXX is requested, reverse proxy
51  *                   # it to http://hostname[:port]/new/pathXXXXXX
52  *
53  * /cgi-bin:foo:bar  # Require user foo, pwd bar on urls starting with /cgi-bin/
54  * /adm:admin:setup  # Require user admin, pwd setup on urls starting with /adm/
55  * /adm:toor:PaSsWd  # or user toor, pwd PaSsWd on urls starting with /adm/
56  * .au:audio/basic   # additional mime type for audio.au files
57  * *.php:/path/php   # run xxx.php through an interpreter
58  *
59  * A/D may be as a/d or allow/deny - only first char matters.
60  * Deny/Allow IP logic:
61  *  - Default is to allow all (Allow all (A:*) is a no-op).
62  *  - Deny rules take precedence over allow rules.
63  *  - "Deny all" rule (D:*) is applied last.
64  *
65  * Example:
66  *   1. Allow only specified addresses
67  *     A:172.20          # Allow any address that begins with 172.20.
68  *     A:10.10.          # Allow any address that begins with 10.10.
69  *     A:127.0.0.1       # Allow local loopback connections
70  *     D:*               # Deny from other IP connections
71  *
72  *   2. Only deny specified addresses
73  *     D:1.2.3.        # deny from 1.2.3.0 - 1.2.3.255
74  *     D:2.3.4.        # deny from 2.3.4.0 - 2.3.4.255
75  *     A:*             # (optional line added for clarity)
76  *
77  * If a sub directory contains a config file it is parsed and merged with
78  * any existing settings as if it was appended to the original configuration.
79  *
80  * subdir paths are relative to the containing subdir and thus cannot
81  * affect the parent rules.
82  *
83  * Note that since the sub dir is parsed in the forked thread servicing the
84  * subdir http request, any merge is discarded when the process exits.  As a
85  * result, the subdir settings only have a lifetime of a single request.
86  *
87  * Custom error pages can contain an absolute path or be relative to
88  * 'home_httpd'. Error pages are to be static files (no CGI or script). Error
89  * page can only be defined in the root configuration file and are not taken
90  * into account in local (directories) config files.
91  *
92  * If -c is not set, an attempt will be made to open the default
93  * root configuration file.  If -c is set and the file is not found, the
94  * server exits with an error.
95  *
96  */
97  /* TODO: use TCP_CORK, parse_config() */
98
99 #include "libbb.h"
100 #if ENABLE_FEATURE_HTTPD_USE_SENDFILE
101 # include <sys/sendfile.h>
102 #endif
103
104 #define DEBUG 0
105
106 #define IOBUF_SIZE 8192    /* IO buffer */
107
108 /* amount of buffering in a pipe */
109 #ifndef PIPE_BUF
110 # define PIPE_BUF 4096
111 #endif
112 #if PIPE_BUF >= IOBUF_SIZE
113 # error "PIPE_BUF >= IOBUF_SIZE"
114 #endif
115
116 #define HEADER_READ_TIMEOUT 60
117
118 static const char DEFAULT_PATH_HTTPD_CONF[] ALIGN1 = "/etc";
119 static const char HTTPD_CONF[] ALIGN1 = "httpd.conf";
120 static const char HTTP_200[] ALIGN1 = "HTTP/1.0 200 OK\r\n";
121
122 typedef struct has_next_ptr {
123         struct has_next_ptr *next;
124 } has_next_ptr;
125
126 /* Must have "next" as a first member */
127 typedef struct Htaccess {
128         struct Htaccess *next;
129         char *after_colon;
130         char before_colon[1];  /* really bigger, must be last */
131 } Htaccess;
132
133 /* Must have "next" as a first member */
134 typedef struct Htaccess_IP {
135         struct Htaccess_IP *next;
136         unsigned ip;
137         unsigned mask;
138         int allow_deny;
139 } Htaccess_IP;
140
141 /* Must have "next" as a first member */
142 typedef struct Htaccess_Proxy {
143         struct Htaccess_Proxy *next;
144         char *url_from;
145         char *host_port;
146         char *url_to;
147 } Htaccess_Proxy;
148
149 enum {
150         HTTP_OK = 200,
151         HTTP_PARTIAL_CONTENT = 206,
152         HTTP_MOVED_TEMPORARILY = 302,
153         HTTP_BAD_REQUEST = 400,       /* malformed syntax */
154         HTTP_UNAUTHORIZED = 401, /* authentication needed, respond with auth hdr */
155         HTTP_NOT_FOUND = 404,
156         HTTP_FORBIDDEN = 403,
157         HTTP_REQUEST_TIMEOUT = 408,
158         HTTP_NOT_IMPLEMENTED = 501,   /* used for unrecognized requests */
159         HTTP_INTERNAL_SERVER_ERROR = 500,
160         HTTP_CONTINUE = 100,
161 #if 0   /* future use */
162         HTTP_SWITCHING_PROTOCOLS = 101,
163         HTTP_CREATED = 201,
164         HTTP_ACCEPTED = 202,
165         HTTP_NON_AUTHORITATIVE_INFO = 203,
166         HTTP_NO_CONTENT = 204,
167         HTTP_MULTIPLE_CHOICES = 300,
168         HTTP_MOVED_PERMANENTLY = 301,
169         HTTP_NOT_MODIFIED = 304,
170         HTTP_PAYMENT_REQUIRED = 402,
171         HTTP_BAD_GATEWAY = 502,
172         HTTP_SERVICE_UNAVAILABLE = 503, /* overload, maintenance */
173         HTTP_RESPONSE_SETSIZE = 0xffffffff
174 #endif
175 };
176
177 static const uint16_t http_response_type[] ALIGN2 = {
178         HTTP_OK,
179 #if ENABLE_FEATURE_HTTPD_RANGES
180         HTTP_PARTIAL_CONTENT,
181 #endif
182         HTTP_MOVED_TEMPORARILY,
183         HTTP_REQUEST_TIMEOUT,
184         HTTP_NOT_IMPLEMENTED,
185 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
186         HTTP_UNAUTHORIZED,
187 #endif
188         HTTP_NOT_FOUND,
189         HTTP_BAD_REQUEST,
190         HTTP_FORBIDDEN,
191         HTTP_INTERNAL_SERVER_ERROR,
192 #if 0   /* not implemented */
193         HTTP_CREATED,
194         HTTP_ACCEPTED,
195         HTTP_NO_CONTENT,
196         HTTP_MULTIPLE_CHOICES,
197         HTTP_MOVED_PERMANENTLY,
198         HTTP_NOT_MODIFIED,
199         HTTP_BAD_GATEWAY,
200         HTTP_SERVICE_UNAVAILABLE,
201 #endif
202 };
203
204 static const struct {
205         const char *name;
206         const char *info;
207 } http_response[ARRAY_SIZE(http_response_type)] = {
208         { "OK", NULL },
209 #if ENABLE_FEATURE_HTTPD_RANGES
210         { "Partial Content", NULL },
211 #endif
212         { "Found", NULL },
213         { "Request Timeout", "No request appeared within 60 seconds" },
214         { "Not Implemented", "The requested method is not recognized" },
215 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
216         { "Unauthorized", "" },
217 #endif
218         { "Not Found", "The requested URL was not found" },
219         { "Bad Request", "Unsupported method" },
220         { "Forbidden", ""  },
221         { "Internal Server Error", "Internal Server Error" },
222 #if 0   /* not implemented */
223         { "Created" },
224         { "Accepted" },
225         { "No Content" },
226         { "Multiple Choices" },
227         { "Moved Permanently" },
228         { "Not Modified" },
229         { "Bad Gateway", "" },
230         { "Service Unavailable", "" },
231 #endif
232 };
233
234 static const char index_html[] ALIGN1 = "index.html";
235
236
237 struct globals {
238         int verbose;            /* must be int (used by getopt32) */
239         smallint flg_deny_all;
240
241         unsigned rmt_ip;        /* used for IP-based allow/deny rules */
242         time_t last_mod;
243         char *rmt_ip_str;       /* for $REMOTE_ADDR and $REMOTE_PORT */
244         const char *bind_addr_or_port;
245
246         const char *g_query;
247         const char *opt_c_configFile;
248         const char *home_httpd;
249         const char *index_page;
250
251         const char *found_mime_type;
252         const char *found_moved_temporarily;
253         Htaccess_IP *ip_a_d;    /* config allow/deny lines */
254
255         IF_FEATURE_HTTPD_BASIC_AUTH(const char *g_realm;)
256         IF_FEATURE_HTTPD_BASIC_AUTH(char *remoteuser;)
257         IF_FEATURE_HTTPD_CGI(char *referer;)
258         IF_FEATURE_HTTPD_CGI(char *user_agent;)
259         IF_FEATURE_HTTPD_CGI(char *host;)
260         IF_FEATURE_HTTPD_CGI(char *http_accept;)
261         IF_FEATURE_HTTPD_CGI(char *http_accept_language;)
262
263         off_t file_size;        /* -1 - unknown */
264 #if ENABLE_FEATURE_HTTPD_RANGES
265         off_t range_start;
266         off_t range_end;
267         off_t range_len;
268 #endif
269
270 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
271         Htaccess *g_auth;       /* config user:password lines */
272 #endif
273         Htaccess *mime_a;       /* config mime types */
274 #if ENABLE_FEATURE_HTTPD_CONFIG_WITH_SCRIPT_INTERPR
275         Htaccess *script_i;     /* config script interpreters */
276 #endif
277         char *iobuf;            /* [IOBUF_SIZE] */
278 #define hdr_buf bb_common_bufsiz1
279         char *hdr_ptr;
280         int hdr_cnt;
281 #if ENABLE_FEATURE_HTTPD_ERROR_PAGES
282         const char *http_error_page[ARRAY_SIZE(http_response_type)];
283 #endif
284 #if ENABLE_FEATURE_HTTPD_PROXY
285         Htaccess_Proxy *proxy;
286 #endif
287 };
288 #define G (*ptr_to_globals)
289 #define verbose           (G.verbose          )
290 #define flg_deny_all      (G.flg_deny_all     )
291 #define rmt_ip            (G.rmt_ip           )
292 #define bind_addr_or_port (G.bind_addr_or_port)
293 #define g_query           (G.g_query          )
294 #define opt_c_configFile  (G.opt_c_configFile )
295 #define home_httpd        (G.home_httpd       )
296 #define index_page        (G.index_page       )
297 #define found_mime_type   (G.found_mime_type  )
298 #define found_moved_temporarily (G.found_moved_temporarily)
299 #define last_mod          (G.last_mod         )
300 #define ip_a_d            (G.ip_a_d           )
301 #define g_realm           (G.g_realm          )
302 #define remoteuser        (G.remoteuser       )
303 #define referer           (G.referer          )
304 #define user_agent        (G.user_agent       )
305 #define host              (G.host             )
306 #define http_accept       (G.http_accept      )
307 #define http_accept_language (G.http_accept_language)
308 #define file_size         (G.file_size        )
309 #if ENABLE_FEATURE_HTTPD_RANGES
310 #define range_start       (G.range_start      )
311 #define range_end         (G.range_end        )
312 #define range_len         (G.range_len        )
313 #else
314 enum {
315         range_start = 0,
316         range_end = MAXINT(off_t) - 1,
317         range_len = MAXINT(off_t),
318 };
319 #endif
320 #define rmt_ip_str        (G.rmt_ip_str       )
321 #define g_auth            (G.g_auth           )
322 #define mime_a            (G.mime_a           )
323 #define script_i          (G.script_i         )
324 #define iobuf             (G.iobuf            )
325 #define hdr_ptr           (G.hdr_ptr          )
326 #define hdr_cnt           (G.hdr_cnt          )
327 #define http_error_page   (G.http_error_page  )
328 #define proxy             (G.proxy            )
329 #define INIT_G() do { \
330         SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
331         IF_FEATURE_HTTPD_BASIC_AUTH(g_realm = "Web Server Authentication";) \
332         bind_addr_or_port = "80"; \
333         index_page = index_html; \
334         file_size = -1; \
335 } while (0)
336
337
338 #define STRNCASECMP(a, str) strncasecmp((a), (str), sizeof(str)-1)
339
340 /* Prototypes */
341 enum {
342         SEND_HEADERS     = (1 << 0),
343         SEND_BODY        = (1 << 1),
344         SEND_HEADERS_AND_BODY = SEND_HEADERS + SEND_BODY,
345 };
346 static void send_file_and_exit(const char *url, int what) NORETURN;
347
348 static void free_llist(has_next_ptr **pptr)
349 {
350         has_next_ptr *cur = *pptr;
351         while (cur) {
352                 has_next_ptr *t = cur;
353                 cur = cur->next;
354                 free(t);
355         }
356         *pptr = NULL;
357 }
358
359 static ALWAYS_INLINE void free_Htaccess_list(Htaccess **pptr)
360 {
361         free_llist((has_next_ptr**)pptr);
362 }
363
364 static ALWAYS_INLINE void free_Htaccess_IP_list(Htaccess_IP **pptr)
365 {
366         free_llist((has_next_ptr**)pptr);
367 }
368
369 /* Returns presumed mask width in bits or < 0 on error.
370  * Updates strp, stores IP at provided pointer */
371 static int scan_ip(const char **strp, unsigned *ipp, unsigned char endc)
372 {
373         const char *p = *strp;
374         int auto_mask = 8;
375         unsigned ip = 0;
376         int j;
377
378         if (*p == '/')
379                 return -auto_mask;
380
381         for (j = 0; j < 4; j++) {
382                 unsigned octet;
383
384                 if ((*p < '0' || *p > '9') && *p != '/' && *p)
385                         return -auto_mask;
386                 octet = 0;
387                 while (*p >= '0' && *p <= '9') {
388                         octet *= 10;
389                         octet += *p - '0';
390                         if (octet > 255)
391                                 return -auto_mask;
392                         p++;
393                 }
394                 if (*p == '.')
395                         p++;
396                 if (*p != '/' && *p)
397                         auto_mask += 8;
398                 ip = (ip << 8) | octet;
399         }
400         if (*p) {
401                 if (*p != endc)
402                         return -auto_mask;
403                 p++;
404                 if (*p == '\0')
405                         return -auto_mask;
406         }
407         *ipp = ip;
408         *strp = p;
409         return auto_mask;
410 }
411
412 /* Returns 0 on success. Stores IP and mask at provided pointers */
413 static int scan_ip_mask(const char *str, unsigned *ipp, unsigned *maskp)
414 {
415         int i;
416         unsigned mask;
417         char *p;
418
419         i = scan_ip(&str, ipp, '/');
420         if (i < 0)
421                 return i;
422
423         if (*str) {
424                 /* there is /xxx after dotted-IP address */
425                 i = bb_strtou(str, &p, 10);
426                 if (*p == '.') {
427                         /* 'xxx' itself is dotted-IP mask, parse it */
428                         /* (return 0 (success) only if it has N.N.N.N form) */
429                         return scan_ip(&str, maskp, '\0') - 32;
430                 }
431                 if (*p)
432                         return -1;
433         }
434
435         if (i > 32)
436                 return -1;
437
438         if (sizeof(unsigned) == 4 && i == 32) {
439                 /* mask >>= 32 below may not work */
440                 mask = 0;
441         } else {
442                 mask = 0xffffffff;
443                 mask >>= i;
444         }
445         /* i == 0 -> *maskp = 0x00000000
446          * i == 1 -> *maskp = 0x80000000
447          * i == 4 -> *maskp = 0xf0000000
448          * i == 31 -> *maskp = 0xfffffffe
449          * i == 32 -> *maskp = 0xffffffff */
450         *maskp = (uint32_t)(~mask);
451         return 0;
452 }
453
454 /*
455  * Parse configuration file into in-memory linked list.
456  *
457  * Any previous IP rules are discarded.
458  * If the flag argument is not SUBDIR_PARSE then all /path and mime rules
459  * are also discarded.  That is, previous settings are retained if flag is
460  * SUBDIR_PARSE.
461  * Error pages are only parsed on the main config file.
462  *
463  * path   Path where to look for httpd.conf (without filename).
464  * flag   Type of the parse request.
465  */
466 /* flag param: */
467 enum {
468         FIRST_PARSE    = 0, /* path will be "/etc" */
469         SIGNALED_PARSE = 1, /* path will be "/etc" */
470         SUBDIR_PARSE   = 2, /* path will be derived from URL */
471 };
472 static void parse_conf(const char *path, int flag)
473 {
474         /* internally used extra flag state */
475         enum { TRY_CURDIR_PARSE = 3 };
476
477         FILE *f;
478         const char *filename;
479         char buf[160];
480
481         /* discard old rules */
482         free_Htaccess_IP_list(&ip_a_d);
483         flg_deny_all = 0;
484         /* retain previous auth and mime config only for subdir parse */
485         if (flag != SUBDIR_PARSE) {
486                 free_Htaccess_list(&mime_a);
487 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
488                 free_Htaccess_list(&g_auth);
489 #endif
490 #if ENABLE_FEATURE_HTTPD_CONFIG_WITH_SCRIPT_INTERPR
491                 free_Htaccess_list(&script_i);
492 #endif
493         }
494
495         filename = opt_c_configFile;
496         if (flag == SUBDIR_PARSE || filename == NULL) {
497                 filename = alloca(strlen(path) + sizeof(HTTPD_CONF) + 2);
498                 sprintf((char *)filename, "%s/%s", path, HTTPD_CONF);
499         }
500
501         while ((f = fopen_for_read(filename)) == NULL) {
502                 if (flag >= SUBDIR_PARSE) { /* SUBDIR or TRY_CURDIR */
503                         /* config file not found, no changes to config */
504                         return;
505                 }
506                 if (flag == FIRST_PARSE) {
507                         /* -c CONFFILE given, but CONFFILE doesn't exist? */
508                         if (opt_c_configFile)
509                                 bb_simple_perror_msg_and_die(opt_c_configFile);
510                         /* else: no -c, thus we looked at /etc/httpd.conf,
511                          * and it's not there. try ./httpd.conf: */
512                 }
513                 flag = TRY_CURDIR_PARSE;
514                 filename = HTTPD_CONF;
515         }
516
517 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
518         /* in "/file:user:pass" lines, we prepend path in subdirs */
519         if (flag != SUBDIR_PARSE)
520                 path = "";
521 #endif
522         /* The lines can be:
523          *
524          * I:default_index_file
525          * H:http_home
526          * [AD]:IP[/mask]   # allow/deny, * for wildcard
527          * Ennn:error.html  # error page for status nnn
528          * P:/url:[http://]hostname[:port]/new/path # reverse proxy
529          * .ext:mime/type   # mime type
530          * *.php:/path/php  # run xxx.php through an interpreter
531          * /file:user:pass  # username and password
532          */
533         while (fgets(buf, sizeof(buf), f) != NULL) {
534                 unsigned strlen_buf;
535                 unsigned char ch;
536                 char *after_colon;
537
538                 { /* remove all whitespace, and # comments */
539                         char *p, *p0;
540
541                         p0 = buf;
542                         /* skip non-whitespace beginning. Often the whole line
543                          * is non-whitespace. We want this case to work fast,
544                          * without needless copying, therefore we don't merge
545                          * this operation into next while loop. */
546                         while ((ch = *p0) != '\0' && ch != '\n' && ch != '#'
547                          && ch != ' ' && ch != '\t'
548                         ) {
549                                 p0++;
550                         }
551                         p = p0;
552                         /* if we enter this loop, we have some whitespace.
553                          * discard it */
554                         while (ch != '\0' && ch != '\n' && ch != '#') {
555                                 if (ch != ' ' && ch != '\t') {
556                                         *p++ = ch;
557                                 }
558                                 ch = *++p0;
559                         }
560                         *p = '\0';
561                         strlen_buf = p - buf;
562                         if (strlen_buf == 0)
563                                 continue; /* empty line */
564                 }
565
566                 after_colon = strchr(buf, ':');
567                 /* strange line? */
568                 if (after_colon == NULL || *++after_colon == '\0')
569                         goto config_error;
570
571                 ch = (buf[0] & ~0x20); /* toupper if it's a letter */
572
573                 if (ch == 'I') {
574                         if (index_page != index_html)
575                                 free((char*)index_page);
576                         index_page = xstrdup(after_colon);
577                         continue;
578                 }
579
580                 /* do not allow jumping around using H in subdir's configs */
581                 if (flag == FIRST_PARSE && ch == 'H') {
582                         home_httpd = xstrdup(after_colon);
583                         xchdir(home_httpd);
584                         continue;
585                 }
586
587                 if (ch == 'A' || ch == 'D') {
588                         Htaccess_IP *pip;
589
590                         if (*after_colon == '*') {
591                                 if (ch == 'D') {
592                                         /* memorize "deny all" */
593                                         flg_deny_all = 1;
594                                 }
595                                 /* skip assumed "A:*", it is a default anyway */
596                                 continue;
597                         }
598                         /* store "allow/deny IP/mask" line */
599                         pip = xzalloc(sizeof(*pip));
600                         if (scan_ip_mask(after_colon, &pip->ip, &pip->mask)) {
601                                 /* IP{/mask} syntax error detected, protect all */
602                                 ch = 'D';
603                                 pip->mask = 0;
604                         }
605                         pip->allow_deny = ch;
606                         if (ch == 'D') {
607                                 /* Deny:from_IP - prepend */
608                                 pip->next = ip_a_d;
609                                 ip_a_d = pip;
610                         } else {
611                                 /* A:from_IP - append (thus all D's precedes A's) */
612                                 Htaccess_IP *prev_IP = ip_a_d;
613                                 if (prev_IP == NULL) {
614                                         ip_a_d = pip;
615                                 } else {
616                                         while (prev_IP->next)
617                                                 prev_IP = prev_IP->next;
618                                         prev_IP->next = pip;
619                                 }
620                         }
621                         continue;
622                 }
623
624 #if ENABLE_FEATURE_HTTPD_ERROR_PAGES
625                 if (flag == FIRST_PARSE && ch == 'E') {
626                         unsigned i;
627                         int status = atoi(buf + 1); /* error status code */
628
629                         if (status < HTTP_CONTINUE) {
630                                 goto config_error;
631                         }
632                         /* then error page; find matching status */
633                         for (i = 0; i < ARRAY_SIZE(http_response_type); i++) {
634                                 if (http_response_type[i] == status) {
635                                         /* We chdir to home_httpd, thus no need to
636                                          * concat_path_file(home_httpd, after_colon)
637                                          * here */
638                                         http_error_page[i] = xstrdup(after_colon);
639                                         break;
640                                 }
641                         }
642                         continue;
643                 }
644 #endif
645
646 #if ENABLE_FEATURE_HTTPD_PROXY
647                 if (flag == FIRST_PARSE && ch == 'P') {
648                         /* P:/url:[http://]hostname[:port]/new/path */
649                         char *url_from, *host_port, *url_to;
650                         Htaccess_Proxy *proxy_entry;
651
652                         url_from = after_colon;
653                         host_port = strchr(after_colon, ':');
654                         if (host_port == NULL) {
655                                 goto config_error;
656                         }
657                         *host_port++ = '\0';
658                         if (strncmp(host_port, "http://", 7) == 0)
659                                 host_port += 7;
660                         if (*host_port == '\0') {
661                                 goto config_error;
662                         }
663                         url_to = strchr(host_port, '/');
664                         if (url_to == NULL) {
665                                 goto config_error;
666                         }
667                         *url_to = '\0';
668                         proxy_entry = xzalloc(sizeof(*proxy_entry));
669                         proxy_entry->url_from = xstrdup(url_from);
670                         proxy_entry->host_port = xstrdup(host_port);
671                         *url_to = '/';
672                         proxy_entry->url_to = xstrdup(url_to);
673                         proxy_entry->next = proxy;
674                         proxy = proxy_entry;
675                         continue;
676                 }
677 #endif
678                 /* the rest of directives are non-alphabetic,
679                  * must avoid using "toupper'ed" ch */
680                 ch = buf[0];
681
682                 if (ch == '.' /* ".ext:mime/type" */
683 #if ENABLE_FEATURE_HTTPD_CONFIG_WITH_SCRIPT_INTERPR
684                  || (ch == '*' && buf[1] == '.') /* "*.php:/path/php" */
685 #endif
686                 ) {
687                         char *p;
688                         Htaccess *cur;
689
690                         cur = xzalloc(sizeof(*cur) /* includes space for NUL */ + strlen_buf);
691                         strcpy(cur->before_colon, buf);
692                         p = cur->before_colon + (after_colon - buf);
693                         p[-1] = '\0';
694                         cur->after_colon = p;
695                         if (ch == '.') {
696                                 /* .mime line: prepend to mime_a list */
697                                 cur->next = mime_a;
698                                 mime_a = cur;
699                         }
700 #if ENABLE_FEATURE_HTTPD_CONFIG_WITH_SCRIPT_INTERPR
701                         else {
702                                 /* script interpreter line: prepend to script_i list */
703                                 cur->next = script_i;
704                                 script_i = cur;
705                         }
706 #endif
707                         continue;
708                 }
709
710 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
711                 if (ch == '/') { /* "/file:user:pass" */
712                         char *p;
713                         Htaccess *cur;
714                         unsigned file_len;
715
716                         /* note: path is "" unless we are in SUBDIR parse,
717                          * otherwise it does NOT start with "/" */
718                         cur = xzalloc(sizeof(*cur) /* includes space for NUL */
719                                 + 1 + strlen(path)
720                                 + strlen_buf
721                                 );
722                         /* form "/path/file" */
723                         sprintf(cur->before_colon, "/%s%.*s",
724                                 path,
725                                 (int) (after_colon - buf - 1), /* includes "/", but not ":" */
726                                 buf);
727                         /* canonicalize it */
728                         p = bb_simplify_abs_path_inplace(cur->before_colon);
729                         file_len = p - cur->before_colon;
730                         /* add "user:pass" after NUL */
731                         strcpy(++p, after_colon);
732                         cur->after_colon = p;
733
734                         /* insert cur into g_auth */
735                         /* g_auth is sorted by decreased filename length */
736                         {
737                                 Htaccess *auth, **authp;
738
739                                 authp = &g_auth;
740                                 while ((auth = *authp) != NULL) {
741                                         if (file_len >= strlen(auth->before_colon)) {
742                                                 /* insert cur before auth */
743                                                 cur->next = auth;
744                                                 break;
745                                         }
746                                         authp = &auth->next;
747                                 }
748                                 *authp = cur;
749                         }
750                         continue;
751                 }
752 #endif /* BASIC_AUTH */
753
754                 /* the line is not recognized */
755  config_error:
756                 bb_error_msg("config error '%s' in '%s'", buf, filename);
757          } /* while (fgets) */
758
759          fclose(f);
760 }
761
762 #if ENABLE_FEATURE_HTTPD_ENCODE_URL_STR
763 /*
764  * Given a string, html-encode special characters.
765  * This is used for the -e command line option to provide an easy way
766  * for scripts to encode result data without confusing browsers.  The
767  * returned string pointer is memory allocated by malloc().
768  *
769  * Returns a pointer to the encoded string (malloced).
770  */
771 static char *encodeString(const char *string)
772 {
773         /* take the simple route and encode everything */
774         /* could possibly scan once to get length.     */
775         int len = strlen(string);
776         char *out = xmalloc(len * 6 + 1);
777         char *p = out;
778         char ch;
779
780         while ((ch = *string++)) {
781                 /* very simple check for what to encode */
782                 if (isalnum(ch))
783                         *p++ = ch;
784                 else
785                         p += sprintf(p, "&#%d;", (unsigned char) ch);
786         }
787         *p = '\0';
788         return out;
789 }
790 #endif          /* FEATURE_HTTPD_ENCODE_URL_STR */
791
792 /*
793  * Given a URL encoded string, convert it to plain ascii.
794  * Since decoding always makes strings smaller, the decode is done in-place.
795  * Thus, callers should xstrdup() the argument if they do not want the
796  * argument modified.  The return is the original pointer, allowing this
797  * function to be easily used as arguments to other functions.
798  *
799  * string    The first string to decode.
800  * option_d  1 if called for httpd -d
801  *
802  * Returns a pointer to the decoded string (same as input).
803  */
804 static unsigned hex_to_bin(unsigned char c)
805 {
806         unsigned v;
807
808         v = c - '0';
809         if (v <= 9)
810                 return v;
811         /* c | 0x20: letters to lower case, non-letters
812          * to (potentially different) non-letters */
813         v = (unsigned)(c | 0x20) - 'a';
814         if (v <= 5)
815                 return v + 10;
816         return ~0;
817 }
818 /* For testing:
819 void t(char c) { printf("'%c'(%u) %u\n", c, c, hex_to_bin(c)); }
820 int main() { t(0x10); t(0x20); t('0'); t('9'); t('A'); t('F'); t('a'); t('f');
821 t('0'-1); t('9'+1); t('A'-1); t('F'+1); t('a'-1); t('f'+1); return 0; }
822 */
823 static char *decodeString(char *orig, int option_d)
824 {
825         /* note that decoded string is always shorter than original */
826         char *string = orig;
827         char *ptr = string;
828         char c;
829
830         while ((c = *ptr++) != '\0') {
831                 unsigned v;
832
833                 if (option_d && c == '+') {
834                         *string++ = ' ';
835                         continue;
836                 }
837                 if (c != '%') {
838                         *string++ = c;
839                         continue;
840                 }
841                 v = hex_to_bin(ptr[0]);
842                 if (v > 15) {
843  bad_hex:
844                         if (!option_d)
845                                 return NULL;
846                         *string++ = '%';
847                         continue;
848                 }
849                 v = (v * 16) | hex_to_bin(ptr[1]);
850                 if (v > 255)
851                         goto bad_hex;
852                 if (!option_d && (v == '/' || v == '\0')) {
853                         /* caller takes it as indication of invalid
854                          * (dangerous wrt exploits) chars */
855                         return orig + 1;
856                 }
857                 *string++ = v;
858                 ptr += 2;
859         }
860         *string = '\0';
861         return orig;
862 }
863
864 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
865 /*
866  * Decode a base64 data stream as per rfc1521.
867  * Note that the rfc states that non base64 chars are to be ignored.
868  * Since the decode always results in a shorter size than the input,
869  * it is OK to pass the input arg as an output arg.
870  * Parameter: a pointer to a base64 encoded string.
871  * Decoded data is stored in-place.
872  */
873 static void decodeBase64(char *Data)
874 {
875         const unsigned char *in = (const unsigned char *)Data;
876         /* The decoded size will be at most 3/4 the size of the encoded */
877         unsigned ch = 0;
878         int i = 0;
879
880         while (*in) {
881                 int t = *in++;
882
883                 if (t >= '0' && t <= '9')
884                         t = t - '0' + 52;
885                 else if (t >= 'A' && t <= 'Z')
886                         t = t - 'A';
887                 else if (t >= 'a' && t <= 'z')
888                         t = t - 'a' + 26;
889                 else if (t == '+')
890                         t = 62;
891                 else if (t == '/')
892                         t = 63;
893                 else if (t == '=')
894                         t = 0;
895                 else
896                         continue;
897
898                 ch = (ch << 6) | t;
899                 i++;
900                 if (i == 4) {
901                         *Data++ = (char) (ch >> 16);
902                         *Data++ = (char) (ch >> 8);
903                         *Data++ = (char) ch;
904                         i = 0;
905                 }
906         }
907         *Data = '\0';
908 }
909 #endif
910
911 /*
912  * Create a listen server socket on the designated port.
913  */
914 static int openServer(void)
915 {
916         unsigned n = bb_strtou(bind_addr_or_port, NULL, 10);
917         if (!errno && n && n <= 0xffff)
918                 n = create_and_bind_stream_or_die(NULL, n);
919         else
920                 n = create_and_bind_stream_or_die(bind_addr_or_port, 80);
921         xlisten(n, 9);
922         return n;
923 }
924
925 /*
926  * Log the connection closure and exit.
927  */
928 static void log_and_exit(void) NORETURN;
929 static void log_and_exit(void)
930 {
931         /* Paranoia. IE said to be buggy. It may send some extra data
932          * or be confused by us just exiting without SHUT_WR. Oh well. */
933         shutdown(1, SHUT_WR);
934         /* Why??
935         (this also messes up stdin when user runs httpd -i from terminal)
936         ndelay_on(0);
937         while (read(STDIN_FILENO, iobuf, IOBUF_SIZE) > 0)
938                 continue;
939         */
940
941         if (verbose > 2)
942                 bb_error_msg("closed");
943         _exit(xfunc_error_retval);
944 }
945
946 /*
947  * Create and send HTTP response headers.
948  * The arguments are combined and sent as one write operation.  Note that
949  * IE will puke big-time if the headers are not sent in one packet and the
950  * second packet is delayed for any reason.
951  * responseNum - the result code to send.
952  */
953 static void send_headers(int responseNum)
954 {
955         static const char RFC1123FMT[] ALIGN1 = "%a, %d %b %Y %H:%M:%S GMT";
956
957         const char *responseString = "";
958         const char *infoString = NULL;
959         const char *mime_type;
960 #if ENABLE_FEATURE_HTTPD_ERROR_PAGES
961         const char *error_page = NULL;
962 #endif
963         unsigned i;
964         time_t timer = time(NULL);
965         char tmp_str[80];
966         int len;
967
968         for (i = 0; i < ARRAY_SIZE(http_response_type); i++) {
969                 if (http_response_type[i] == responseNum) {
970                         responseString = http_response[i].name;
971                         infoString = http_response[i].info;
972 #if ENABLE_FEATURE_HTTPD_ERROR_PAGES
973                         error_page = http_error_page[i];
974 #endif
975                         break;
976                 }
977         }
978         /* error message is HTML */
979         mime_type = responseNum == HTTP_OK ?
980                                 found_mime_type : "text/html";
981
982         if (verbose)
983                 bb_error_msg("response:%u", responseNum);
984
985         /* emit the current date */
986         strftime(tmp_str, sizeof(tmp_str), RFC1123FMT, gmtime(&timer));
987         len = sprintf(iobuf,
988                         "HTTP/1.0 %d %s\r\nContent-type: %s\r\n"
989                         "Date: %s\r\nConnection: close\r\n",
990                         responseNum, responseString, mime_type, tmp_str);
991
992 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
993         if (responseNum == HTTP_UNAUTHORIZED) {
994                 len += sprintf(iobuf + len,
995                                 "WWW-Authenticate: Basic realm=\"%s\"\r\n",
996                                 g_realm);
997         }
998 #endif
999         if (responseNum == HTTP_MOVED_TEMPORARILY) {
1000                 len += sprintf(iobuf + len, "Location: %s/%s%s\r\n",
1001                                 found_moved_temporarily,
1002                                 (g_query ? "?" : ""),
1003                                 (g_query ? g_query : ""));
1004         }
1005
1006 #if ENABLE_FEATURE_HTTPD_ERROR_PAGES
1007         if (error_page && access(error_page, R_OK) == 0) {
1008                 strcat(iobuf, "\r\n");
1009                 len += 2;
1010
1011                 if (DEBUG)
1012                         fprintf(stderr, "headers: '%s'\n", iobuf);
1013                 full_write(STDOUT_FILENO, iobuf, len);
1014                 if (DEBUG)
1015                         fprintf(stderr, "writing error page: '%s'\n", error_page);
1016                 return send_file_and_exit(error_page, SEND_BODY);
1017         }
1018 #endif
1019
1020         if (file_size != -1) {    /* file */
1021                 strftime(tmp_str, sizeof(tmp_str), RFC1123FMT, gmtime(&last_mod));
1022 #if ENABLE_FEATURE_HTTPD_RANGES
1023                 if (responseNum == HTTP_PARTIAL_CONTENT) {
1024                         len += sprintf(iobuf + len, "Content-Range: bytes %"OFF_FMT"d-%"OFF_FMT"d/%"OFF_FMT"d\r\n",
1025                                         range_start,
1026                                         range_end,
1027                                         file_size);
1028                         file_size = range_end - range_start + 1;
1029                 }
1030 #endif
1031                 len += sprintf(iobuf + len,
1032 #if ENABLE_FEATURE_HTTPD_RANGES
1033                         "Accept-Ranges: bytes\r\n"
1034 #endif
1035                         "Last-Modified: %s\r\n%s %"OFF_FMT"d\r\n",
1036                                 tmp_str,
1037                                 "Content-length:",
1038                                 file_size
1039                 );
1040         }
1041         iobuf[len++] = '\r';
1042         iobuf[len++] = '\n';
1043         if (infoString) {
1044                 len += sprintf(iobuf + len,
1045                                 "<HTML><HEAD><TITLE>%d %s</TITLE></HEAD>\n"
1046                                 "<BODY><H1>%d %s</H1>\n%s\n</BODY></HTML>\n",
1047                                 responseNum, responseString,
1048                                 responseNum, responseString, infoString);
1049         }
1050         if (DEBUG)
1051                 fprintf(stderr, "headers: '%s'\n", iobuf);
1052         if (full_write(STDOUT_FILENO, iobuf, len) != len) {
1053                 if (verbose > 1)
1054                         bb_perror_msg("error");
1055                 log_and_exit();
1056         }
1057 }
1058
1059 static void send_headers_and_exit(int responseNum) NORETURN;
1060 static void send_headers_and_exit(int responseNum)
1061 {
1062         send_headers(responseNum);
1063         log_and_exit();
1064 }
1065
1066 /*
1067  * Read from the socket until '\n' or EOF. '\r' chars are removed.
1068  * '\n' is replaced with NUL.
1069  * Return number of characters read or 0 if nothing is read
1070  * ('\r' and '\n' are not counted).
1071  * Data is returned in iobuf.
1072  */
1073 static int get_line(void)
1074 {
1075         int count = 0;
1076         char c;
1077
1078         alarm(HEADER_READ_TIMEOUT);
1079         while (1) {
1080                 if (hdr_cnt <= 0) {
1081                         hdr_cnt = safe_read(STDIN_FILENO, hdr_buf, sizeof(hdr_buf));
1082                         if (hdr_cnt <= 0)
1083                                 break;
1084                         hdr_ptr = hdr_buf;
1085                 }
1086                 iobuf[count] = c = *hdr_ptr++;
1087                 hdr_cnt--;
1088
1089                 if (c == '\r')
1090                         continue;
1091                 if (c == '\n') {
1092                         iobuf[count] = '\0';
1093                         break;
1094                 }
1095                 if (count < (IOBUF_SIZE - 1))      /* check overflow */
1096                         count++;
1097         }
1098         return count;
1099 }
1100
1101 #if ENABLE_FEATURE_HTTPD_CGI || ENABLE_FEATURE_HTTPD_PROXY
1102
1103 /* gcc 4.2.1 fares better with NOINLINE */
1104 static NOINLINE void cgi_io_loop_and_exit(int fromCgi_rd, int toCgi_wr, int post_len) NORETURN;
1105 static NOINLINE void cgi_io_loop_and_exit(int fromCgi_rd, int toCgi_wr, int post_len)
1106 {
1107         enum { FROM_CGI = 1, TO_CGI = 2 }; /* indexes in pfd[] */
1108         struct pollfd pfd[3];
1109         int out_cnt; /* we buffer a bit of initial CGI output */
1110         int count;
1111
1112         /* iobuf is used for CGI -> network data,
1113          * hdr_buf is for network -> CGI data (POSTDATA) */
1114
1115         /* If CGI dies, we still want to correctly finish reading its output
1116          * and send it to the peer. So please no SIGPIPEs! */
1117         signal(SIGPIPE, SIG_IGN);
1118
1119         // We inconsistently handle a case when more POSTDATA from network
1120         // is coming than we expected. We may give *some part* of that
1121         // extra data to CGI.
1122
1123         //if (hdr_cnt > post_len) {
1124         //      /* We got more POSTDATA from network than we expected */
1125         //      hdr_cnt = post_len;
1126         //}
1127         post_len -= hdr_cnt;
1128         /* post_len - number of POST bytes not yet read from network */
1129
1130         /* NB: breaking out of this loop jumps to log_and_exit() */
1131         out_cnt = 0;
1132         while (1) {
1133                 memset(pfd, 0, sizeof(pfd));
1134
1135                 pfd[FROM_CGI].fd = fromCgi_rd;
1136                 pfd[FROM_CGI].events = POLLIN;
1137
1138                 if (toCgi_wr) {
1139                         pfd[TO_CGI].fd = toCgi_wr;
1140                         if (hdr_cnt > 0) {
1141                                 pfd[TO_CGI].events = POLLOUT;
1142                         } else if (post_len > 0) {
1143                                 pfd[0].events = POLLIN;
1144                         } else {
1145                                 /* post_len <= 0 && hdr_cnt <= 0:
1146                                  * no more POST data to CGI,
1147                                  * let CGI see EOF on CGI's stdin */
1148                                 close(toCgi_wr);
1149                                 toCgi_wr = 0;
1150                         }
1151                 }
1152
1153                 /* Now wait on the set of sockets */
1154                 count = safe_poll(pfd, 3, -1);
1155                 if (count <= 0) {
1156 #if 0
1157                         if (safe_waitpid(pid, &status, WNOHANG) <= 0) {
1158                                 /* Weird. CGI didn't exit and no fd's
1159                                  * are ready, yet poll returned?! */
1160                                 continue;
1161                         }
1162                         if (DEBUG && WIFEXITED(status))
1163                                 bb_error_msg("CGI exited, status=%d", WEXITSTATUS(status));
1164                         if (DEBUG && WIFSIGNALED(status))
1165                                 bb_error_msg("CGI killed, signal=%d", WTERMSIG(status));
1166 #endif
1167                         break;
1168                 }
1169
1170                 if (pfd[TO_CGI].revents) {
1171                         /* hdr_cnt > 0 here due to the way pfd[TO_CGI].events set */
1172                         /* Have data from peer and can write to CGI */
1173                         count = safe_write(toCgi_wr, hdr_ptr, hdr_cnt);
1174                         /* Doesn't happen, we dont use nonblocking IO here
1175                          *if (count < 0 && errno == EAGAIN) {
1176                          *      ...
1177                          *} else */
1178                         if (count > 0) {
1179                                 hdr_ptr += count;
1180                                 hdr_cnt -= count;
1181                         } else {
1182                                 /* EOF/broken pipe to CGI, stop piping POST data */
1183                                 hdr_cnt = post_len = 0;
1184                         }
1185                 }
1186
1187                 if (pfd[0].revents) {
1188                         /* post_len > 0 && hdr_cnt == 0 here */
1189                         /* We expect data, prev data portion is eaten by CGI
1190                          * and there *is* data to read from the peer
1191                          * (POSTDATA) */
1192                         //count = post_len > (int)sizeof(hdr_buf) ? (int)sizeof(hdr_buf) : post_len;
1193                         //count = safe_read(STDIN_FILENO, hdr_buf, count);
1194                         count = safe_read(STDIN_FILENO, hdr_buf, sizeof(hdr_buf));
1195                         if (count > 0) {
1196                                 hdr_cnt = count;
1197                                 hdr_ptr = hdr_buf;
1198                                 post_len -= count;
1199                         } else {
1200                                 /* no more POST data can be read */
1201                                 post_len = 0;
1202                         }
1203                 }
1204
1205                 if (pfd[FROM_CGI].revents) {
1206                         /* There is something to read from CGI */
1207                         char *rbuf = iobuf;
1208
1209                         /* Are we still buffering CGI output? */
1210                         if (out_cnt >= 0) {
1211                                 /* HTTP_200[] has single "\r\n" at the end.
1212                                  * According to http://hoohoo.ncsa.uiuc.edu/cgi/out.html,
1213                                  * CGI scripts MUST send their own header terminated by
1214                                  * empty line, then data. That's why we have only one
1215                                  * <cr><lf> pair here. We will output "200 OK" line
1216                                  * if needed, but CGI still has to provide blank line
1217                                  * between header and body */
1218
1219                                 /* Must use safe_read, not full_read, because
1220                                  * CGI may output a few first bytes and then wait
1221                                  * for POSTDATA without closing stdout.
1222                                  * With full_read we may wait here forever. */
1223                                 count = safe_read(fromCgi_rd, rbuf + out_cnt, PIPE_BUF - 8);
1224                                 if (count <= 0) {
1225                                         /* eof (or error) and there was no "HTTP",
1226                                          * so write it, then write received data */
1227                                         if (out_cnt) {
1228                                                 full_write(STDOUT_FILENO, HTTP_200, sizeof(HTTP_200)-1);
1229                                                 full_write(STDOUT_FILENO, rbuf, out_cnt);
1230                                         }
1231                                         break; /* CGI stdout is closed, exiting */
1232                                 }
1233                                 out_cnt += count;
1234                                 count = 0;
1235                                 /* "Status" header format is: "Status: 302 Redirected\r\n" */
1236                                 if (out_cnt >= 8 && memcmp(rbuf, "Status: ", 8) == 0) {
1237                                         /* send "HTTP/1.0 " */
1238                                         if (full_write(STDOUT_FILENO, HTTP_200, 9) != 9)
1239                                                 break;
1240                                         rbuf += 8; /* skip "Status: " */
1241                                         count = out_cnt - 8;
1242                                         out_cnt = -1; /* buffering off */
1243                                 } else if (out_cnt >= 4) {
1244                                         /* Did CGI add "HTTP"? */
1245                                         if (memcmp(rbuf, HTTP_200, 4) != 0) {
1246                                                 /* there is no "HTTP", do it ourself */
1247                                                 if (full_write(STDOUT_FILENO, HTTP_200, sizeof(HTTP_200)-1) != sizeof(HTTP_200)-1)
1248                                                         break;
1249                                         }
1250                                         /* Commented out:
1251                                         if (!strstr(rbuf, "ontent-")) {
1252                                                 full_write(s, "Content-type: text/plain\r\n\r\n", 28);
1253                                         }
1254                                          * Counter-example of valid CGI without Content-type:
1255                                          * echo -en "HTTP/1.0 302 Found\r\n"
1256                                          * echo -en "Location: http://www.busybox.net\r\n"
1257                                          * echo -en "\r\n"
1258                                          */
1259                                         count = out_cnt;
1260                                         out_cnt = -1; /* buffering off */
1261                                 }
1262                         } else {
1263                                 count = safe_read(fromCgi_rd, rbuf, PIPE_BUF);
1264                                 if (count <= 0)
1265                                         break;  /* eof (or error) */
1266                         }
1267                         if (full_write(STDOUT_FILENO, rbuf, count) != count)
1268                                 break;
1269                         if (DEBUG)
1270                                 fprintf(stderr, "cgi read %d bytes: '%.*s'\n", count, count, rbuf);
1271                 } /* if (pfd[FROM_CGI].revents) */
1272         } /* while (1) */
1273         log_and_exit();
1274 }
1275 #endif
1276
1277 #if ENABLE_FEATURE_HTTPD_CGI
1278
1279 static void setenv1(const char *name, const char *value)
1280 {
1281         setenv(name, value ? value : "", 1);
1282 }
1283
1284 /*
1285  * Spawn CGI script, forward CGI's stdin/out <=> network
1286  *
1287  * Environment variables are set up and the script is invoked with pipes
1288  * for stdin/stdout.  If a POST is being done the script is fed the POST
1289  * data in addition to setting the QUERY_STRING variable (for GETs or POSTs).
1290  *
1291  * Parameters:
1292  * const char *url              The requested URL (with leading /).
1293  * int post_len                 Length of the POST body.
1294  * const char *cookie           For set HTTP_COOKIE.
1295  * const char *content_type     For set CONTENT_TYPE.
1296  */
1297 static void send_cgi_and_exit(
1298                 const char *url,
1299                 const char *request,
1300                 int post_len,
1301                 const char *cookie,
1302                 const char *content_type) NORETURN;
1303 static void send_cgi_and_exit(
1304                 const char *url,
1305                 const char *request,
1306                 int post_len,
1307                 const char *cookie,
1308                 const char *content_type)
1309 {
1310         struct fd_pair fromCgi;  /* CGI -> httpd pipe */
1311         struct fd_pair toCgi;    /* httpd -> CGI pipe */
1312         char *script;
1313         int pid;
1314
1315         /* Make a copy. NB: caller guarantees:
1316          * url[0] == '/', url[1] != '/' */
1317         url = xstrdup(url);
1318
1319         /*
1320          * We are mucking with environment _first_ and then vfork/exec,
1321          * this allows us to use vfork safely. Parent doesn't care about
1322          * these environment changes anyway.
1323          */
1324
1325         /* Check for [dirs/]script.cgi/PATH_INFO */
1326         script = (char*)url;
1327         while ((script = strchr(script + 1, '/')) != NULL) {
1328                 struct stat sb;
1329
1330                 *script = '\0';
1331                 if (!is_directory(url + 1, 1, &sb)) {
1332                         /* not directory, found script.cgi/PATH_INFO */
1333                         *script = '/';
1334                         break;
1335                 }
1336                 *script = '/'; /* is directory, find next '/' */
1337         }
1338         setenv1("PATH_INFO", script);   /* set to /PATH_INFO or "" */
1339         setenv1("REQUEST_METHOD", request);
1340         if (g_query) {
1341                 putenv(xasprintf("%s=%s?%s", "REQUEST_URI", url, g_query));
1342         } else {
1343                 setenv1("REQUEST_URI", url);
1344         }
1345         if (script != NULL)
1346                 *script = '\0';         /* cut off /PATH_INFO */
1347
1348         /* SCRIPT_FILENAME is required by PHP in CGI mode */
1349         if (home_httpd[0] == '/') {
1350                 char *fullpath = concat_path_file(home_httpd, url);
1351                 setenv1("SCRIPT_FILENAME", fullpath);
1352         }
1353         /* set SCRIPT_NAME as full path: /cgi-bin/dirs/script.cgi */
1354         setenv1("SCRIPT_NAME", url);
1355         /* http://hoohoo.ncsa.uiuc.edu/cgi/env.html:
1356          * QUERY_STRING: The information which follows the ? in the URL
1357          * which referenced this script. This is the query information.
1358          * It should not be decoded in any fashion. This variable
1359          * should always be set when there is query information,
1360          * regardless of command line decoding. */
1361         /* (Older versions of bbox seem to do some decoding) */
1362         setenv1("QUERY_STRING", g_query);
1363         putenv((char*)"SERVER_SOFTWARE=busybox httpd/"BB_VER);
1364         putenv((char*)"SERVER_PROTOCOL=HTTP/1.0");
1365         putenv((char*)"GATEWAY_INTERFACE=CGI/1.1");
1366         /* Having _separate_ variables for IP and port defeats
1367          * the purpose of having socket abstraction. Which "port"
1368          * are you using on Unix domain socket?
1369          * IOW - REMOTE_PEER="1.2.3.4:56" makes much more sense.
1370          * Oh well... */
1371         {
1372                 char *p = rmt_ip_str ? rmt_ip_str : (char*)"";
1373                 char *cp = strrchr(p, ':');
1374                 if (ENABLE_FEATURE_IPV6 && cp && strchr(cp, ']'))
1375                         cp = NULL;
1376                 if (cp) *cp = '\0'; /* delete :PORT */
1377                 setenv1("REMOTE_ADDR", p);
1378                 if (cp) {
1379                         *cp = ':';
1380 #if ENABLE_FEATURE_HTTPD_SET_REMOTE_PORT_TO_ENV
1381                         setenv1("REMOTE_PORT", cp + 1);
1382 #endif
1383                 }
1384         }
1385         setenv1("HTTP_USER_AGENT", user_agent);
1386         if (http_accept)
1387                 setenv1("HTTP_ACCEPT", http_accept);
1388         if (http_accept_language)
1389                 setenv1("HTTP_ACCEPT_LANGUAGE", http_accept_language);
1390         if (post_len)
1391                 putenv(xasprintf("CONTENT_LENGTH=%d", post_len));
1392         if (cookie)
1393                 setenv1("HTTP_COOKIE", cookie);
1394         if (content_type)
1395                 setenv1("CONTENT_TYPE", content_type);
1396 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
1397         if (remoteuser) {
1398                 setenv1("REMOTE_USER", remoteuser);
1399                 putenv((char*)"AUTH_TYPE=Basic");
1400         }
1401 #endif
1402         if (referer)
1403                 setenv1("HTTP_REFERER", referer);
1404         setenv1("HTTP_HOST", host); /* set to "" if NULL */
1405         /* setenv1("SERVER_NAME", safe_gethostname()); - don't do this,
1406          * just run "env SERVER_NAME=xyz httpd ..." instead */
1407
1408         xpiped_pair(fromCgi);
1409         xpiped_pair(toCgi);
1410
1411         pid = vfork();
1412         if (pid < 0) {
1413                 /* TODO: log perror? */
1414                 log_and_exit();
1415         }
1416
1417         if (!pid) {
1418                 /* Child process */
1419                 char *argv[3];
1420
1421                 xfunc_error_retval = 242;
1422
1423                 /* NB: close _first_, then move fds! */
1424                 close(toCgi.wr);
1425                 close(fromCgi.rd);
1426                 xmove_fd(toCgi.rd, 0);  /* replace stdin with the pipe */
1427                 xmove_fd(fromCgi.wr, 1);  /* replace stdout with the pipe */
1428                 /* User seeing stderr output can be a security problem.
1429                  * If CGI really wants that, it can always do dup itself. */
1430                 /* dup2(1, 2); */
1431
1432                 /* Chdiring to script's dir */
1433                 script = strrchr(url, '/');
1434                 if (script != url) { /* paranoia */
1435                         *script = '\0';
1436                         if (chdir(url + 1) != 0) {
1437                                 bb_perror_msg("chdir %s", url + 1);
1438                                 goto error_execing_cgi;
1439                         }
1440                         // not needed: *script = '/';
1441                 }
1442                 script++;
1443
1444                 /* set argv[0] to name without path */
1445                 argv[0] = script;
1446                 argv[1] = NULL;
1447
1448 #if ENABLE_FEATURE_HTTPD_CONFIG_WITH_SCRIPT_INTERPR
1449                 {
1450                         char *suffix = strrchr(script, '.');
1451
1452                         if (suffix) {
1453                                 Htaccess *cur;
1454                                 for (cur = script_i; cur; cur = cur->next) {
1455                                         if (strcmp(cur->before_colon + 1, suffix) == 0) {
1456                                                 /* found interpreter name */
1457                                                 argv[0] = cur->after_colon;
1458                                                 argv[1] = script;
1459                                                 argv[2] = NULL;
1460                                                 break;
1461                                         }
1462                                 }
1463                         }
1464                 }
1465 #endif
1466                 /* restore default signal dispositions for CGI process */
1467                 bb_signals(0
1468                         | (1 << SIGCHLD)
1469                         | (1 << SIGPIPE)
1470                         | (1 << SIGHUP)
1471                         , SIG_DFL);
1472
1473                 /* _NOT_ execvp. We do not search PATH. argv[0] is a filename
1474                  * without any dir components and will only match a file
1475                  * in the current directory */
1476                 execv(argv[0], argv);
1477                 if (verbose)
1478                         bb_perror_msg("exec %s", argv[0]);
1479  error_execing_cgi:
1480                 /* send to stdout
1481                  * (we are CGI here, our stdout is pumped to the net) */
1482                 send_headers_and_exit(HTTP_NOT_FOUND);
1483         } /* end child */
1484
1485         /* Parent process */
1486
1487         /* Restore variables possibly changed by child */
1488         xfunc_error_retval = 0;
1489
1490         /* Pump data */
1491         close(fromCgi.wr);
1492         close(toCgi.rd);
1493         cgi_io_loop_and_exit(fromCgi.rd, toCgi.wr, post_len);
1494 }
1495
1496 #endif          /* FEATURE_HTTPD_CGI */
1497
1498 /*
1499  * Send a file response to a HTTP request, and exit
1500  *
1501  * Parameters:
1502  * const char *url  The requested URL (with leading /).
1503  * what             What to send (headers/body/both).
1504  */
1505 static NOINLINE void send_file_and_exit(const char *url, int what)
1506 {
1507         static const char *const suffixTable[] = {
1508         /* Warning: shorter equivalent suffix in one line must be first */
1509                 ".htm.html", "text/html",
1510                 ".jpg.jpeg", "image/jpeg",
1511                 ".gif",      "image/gif",
1512                 ".png",      "image/png",
1513                 ".txt.h.c.cc.cpp", "text/plain",
1514                 ".css",      "text/css",
1515                 ".wav",      "audio/wav",
1516                 ".avi",      "video/x-msvideo",
1517                 ".qt.mov",   "video/quicktime",
1518                 ".mpe.mpeg", "video/mpeg",
1519                 ".mid.midi", "audio/midi",
1520                 ".mp3",      "audio/mpeg",
1521 #if 0                        /* unpopular */
1522                 ".au",       "audio/basic",
1523                 ".pac",      "application/x-ns-proxy-autoconfig",
1524                 ".vrml.wrl", "model/vrml",
1525 #endif
1526                 NULL
1527         };
1528
1529         char *suffix;
1530         int fd;
1531         const char *const *table;
1532         const char *try_suffix;
1533         ssize_t count;
1534
1535         fd = open(url, O_RDONLY);
1536         if (fd < 0) {
1537                 if (DEBUG)
1538                         bb_perror_msg("can't open '%s'", url);
1539                 /* Error pages are sent by using send_file_and_exit(SEND_BODY).
1540                  * IOW: it is unsafe to call send_headers_and_exit
1541                  * if what is SEND_BODY! Can recurse! */
1542                 if (what != SEND_BODY)
1543                         send_headers_and_exit(HTTP_NOT_FOUND);
1544                 log_and_exit();
1545         }
1546         /* If you want to know about EPIPE below
1547          * (happens if you abort downloads from local httpd): */
1548         signal(SIGPIPE, SIG_IGN);
1549
1550         suffix = strrchr(url, '.');
1551
1552         /* If not found, set default as "application/octet-stream";  */
1553         found_mime_type = "application/octet-stream";
1554         if (suffix) {
1555                 Htaccess *cur;
1556                 for (table = suffixTable; *table; table += 2) {
1557                         try_suffix = strstr(table[0], suffix);
1558                         if (try_suffix) {
1559                                 try_suffix += strlen(suffix);
1560                                 if (*try_suffix == '\0' || *try_suffix == '.') {
1561                                         found_mime_type = table[1];
1562                                         break;
1563                                 }
1564                         }
1565                 }
1566                 for (cur = mime_a; cur; cur = cur->next) {
1567                         if (strcmp(cur->before_colon, suffix) == 0) {
1568                                 found_mime_type = cur->after_colon;
1569                                 break;
1570                         }
1571                 }
1572         }
1573
1574         if (DEBUG)
1575                 bb_error_msg("sending file '%s' content-type: %s",
1576                         url, found_mime_type);
1577
1578 #if ENABLE_FEATURE_HTTPD_RANGES
1579         if (what == SEND_BODY)
1580                 range_start = 0; /* err pages and ranges don't mix */
1581         range_len = MAXINT(off_t);
1582         if (range_start) {
1583                 if (!range_end) {
1584                         range_end = file_size - 1;
1585                 }
1586                 if (range_end < range_start
1587                  || lseek(fd, range_start, SEEK_SET) != range_start
1588                 ) {
1589                         lseek(fd, 0, SEEK_SET);
1590                         range_start = 0;
1591                 } else {
1592                         range_len = range_end - range_start + 1;
1593                         send_headers(HTTP_PARTIAL_CONTENT);
1594                         what = SEND_BODY;
1595                 }
1596         }
1597 #endif
1598         if (what & SEND_HEADERS)
1599                 send_headers(HTTP_OK);
1600 #if ENABLE_FEATURE_HTTPD_USE_SENDFILE
1601         {
1602                 off_t offset = range_start;
1603                 while (1) {
1604                         /* sz is rounded down to 64k */
1605                         ssize_t sz = MAXINT(ssize_t) - 0xffff;
1606                         IF_FEATURE_HTTPD_RANGES(if (sz > range_len) sz = range_len;)
1607                         count = sendfile(STDOUT_FILENO, fd, &offset, sz);
1608                         if (count < 0) {
1609                                 if (offset == range_start)
1610                                         break; /* fall back to read/write loop */
1611                                 goto fin;
1612                         }
1613                         IF_FEATURE_HTTPD_RANGES(range_len -= sz;)
1614                         if (count == 0 || range_len == 0)
1615                                 log_and_exit();
1616                 }
1617         }
1618 #endif
1619         while ((count = safe_read(fd, iobuf, IOBUF_SIZE)) > 0) {
1620                 ssize_t n;
1621                 IF_FEATURE_HTTPD_RANGES(if (count > range_len) count = range_len;)
1622                 n = full_write(STDOUT_FILENO, iobuf, count);
1623                 if (count != n)
1624                         break;
1625                 IF_FEATURE_HTTPD_RANGES(range_len -= count;)
1626                 if (range_len == 0)
1627                         break;
1628         }
1629         if (count < 0) {
1630  IF_FEATURE_HTTPD_USE_SENDFILE(fin:)
1631                 if (verbose > 1)
1632                         bb_perror_msg("error");
1633         }
1634         log_and_exit();
1635 }
1636
1637 static int checkPermIP(void)
1638 {
1639         Htaccess_IP *cur;
1640
1641         for (cur = ip_a_d; cur; cur = cur->next) {
1642 #if DEBUG
1643                 fprintf(stderr,
1644                         "checkPermIP: '%s' ? '%u.%u.%u.%u/%u.%u.%u.%u'\n",
1645                         rmt_ip_str,
1646                         (unsigned char)(cur->ip >> 24),
1647                         (unsigned char)(cur->ip >> 16),
1648                         (unsigned char)(cur->ip >> 8),
1649                         (unsigned char)(cur->ip),
1650                         (unsigned char)(cur->mask >> 24),
1651                         (unsigned char)(cur->mask >> 16),
1652                         (unsigned char)(cur->mask >> 8),
1653                         (unsigned char)(cur->mask)
1654                 );
1655 #endif
1656                 if ((rmt_ip & cur->mask) == cur->ip)
1657                         return (cur->allow_deny == 'A'); /* A -> 1 */
1658         }
1659
1660         return !flg_deny_all; /* depends on whether we saw "D:*" */
1661 }
1662
1663 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
1664 /*
1665  * Config file entries are of the form "/<path>:<user>:<passwd>".
1666  * If config file has no prefix match for path, access is allowed.
1667  *
1668  * path                 The file path
1669  * user_and_passwd      "user:passwd" to validate
1670  *
1671  * Returns 1 if user_and_passwd is OK.
1672  */
1673 static int check_user_passwd(const char *path, const char *user_and_passwd)
1674 {
1675         Htaccess *cur;
1676         const char *prev = NULL;
1677
1678         for (cur = g_auth; cur; cur = cur->next) {
1679                 const char *dir_prefix;
1680                 size_t len;
1681
1682                 dir_prefix = cur->before_colon;
1683
1684                 /* WHY? */
1685                 /* If already saw a match, don't accept other different matches */
1686                 if (prev && strcmp(prev, dir_prefix) != 0)
1687                         continue;
1688
1689                 if (DEBUG)
1690                         fprintf(stderr, "checkPerm: '%s' ? '%s'\n", dir_prefix, user_and_passwd);
1691
1692                 /* If it's not a prefix match, continue searching */
1693                 len = strlen(dir_prefix);
1694                 if (len != 1 /* dir_prefix "/" matches all, don't need to check */
1695                  && (strncmp(dir_prefix, path, len) != 0
1696                     || (path[len] != '/' && path[len] != '\0'))
1697                 ) {
1698                         continue;
1699                 }
1700
1701                 /* Path match found */
1702                 prev = dir_prefix;
1703
1704                 if (ENABLE_FEATURE_HTTPD_AUTH_MD5) {
1705                         char *md5_passwd;
1706
1707                         md5_passwd = strchr(cur->after_colon, ':');
1708                         if (md5_passwd && md5_passwd[1] == '$' && md5_passwd[2] == '1'
1709                          && md5_passwd[3] == '$' && md5_passwd[4]
1710                         ) {
1711                                 char *encrypted;
1712                                 int r, user_len_p1;
1713
1714                                 md5_passwd++;
1715                                 user_len_p1 = md5_passwd - cur->after_colon;
1716                                 /* comparing "user:" */
1717                                 if (strncmp(cur->after_colon, user_and_passwd, user_len_p1) != 0) {
1718                                         continue;
1719                                 }
1720
1721                                 encrypted = pw_encrypt(
1722                                         user_and_passwd + user_len_p1 /* cleartext pwd from user */,
1723                                         md5_passwd /*salt */, 1 /* cleanup */);
1724                                 r = strcmp(encrypted, md5_passwd);
1725                                 free(encrypted);
1726                                 if (r == 0)
1727                                         goto set_remoteuser_var; /* Ok */
1728                                 continue;
1729                         }
1730                 }
1731
1732                 /* Comparing plaintext "user:pass" in one go */
1733                 if (strcmp(cur->after_colon, user_and_passwd) == 0) {
1734  set_remoteuser_var:
1735                         remoteuser = xstrndup(user_and_passwd,
1736                                         strchrnul(user_and_passwd, ':') - user_and_passwd);
1737                         return 1; /* Ok */
1738                 }
1739         } /* for */
1740
1741         /* 0(bad) if prev is set: matches were found but passwd was wrong */
1742         return (prev == NULL);
1743 }
1744 #endif  /* FEATURE_HTTPD_BASIC_AUTH */
1745
1746 #if ENABLE_FEATURE_HTTPD_PROXY
1747 static Htaccess_Proxy *find_proxy_entry(const char *url)
1748 {
1749         Htaccess_Proxy *p;
1750         for (p = proxy; p; p = p->next) {
1751                 if (strncmp(url, p->url_from, strlen(p->url_from)) == 0)
1752                         return p;
1753         }
1754         return NULL;
1755 }
1756 #endif
1757
1758 /*
1759  * Handle timeouts
1760  */
1761 static void send_REQUEST_TIMEOUT_and_exit(int sig) NORETURN;
1762 static void send_REQUEST_TIMEOUT_and_exit(int sig UNUSED_PARAM)
1763 {
1764         send_headers_and_exit(HTTP_REQUEST_TIMEOUT);
1765 }
1766
1767 /*
1768  * Handle an incoming http request and exit.
1769  */
1770 static void handle_incoming_and_exit(const len_and_sockaddr *fromAddr) NORETURN;
1771 static void handle_incoming_and_exit(const len_and_sockaddr *fromAddr)
1772 {
1773         static const char request_GET[] ALIGN1 = "GET";
1774         struct stat sb;
1775         char *urlcopy;
1776         char *urlp;
1777         char *tptr;
1778 #if ENABLE_FEATURE_HTTPD_CGI
1779         static const char request_HEAD[] ALIGN1 = "HEAD";
1780         const char *prequest;
1781         char *cookie = NULL;
1782         char *content_type = NULL;
1783         unsigned long length = 0;
1784 #elif ENABLE_FEATURE_HTTPD_PROXY
1785 #define prequest request_GET
1786         unsigned long length = 0;
1787 #endif
1788 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
1789         smallint authorized = -1;
1790 #endif
1791         smallint ip_allowed;
1792         char http_major_version;
1793 #if ENABLE_FEATURE_HTTPD_PROXY
1794         char http_minor_version;
1795         char *header_buf = header_buf; /* for gcc */
1796         char *header_ptr = header_ptr;
1797         Htaccess_Proxy *proxy_entry;
1798 #endif
1799
1800         /* Allocation of iobuf is postponed until now
1801          * (IOW, server process doesn't need to waste 8k) */
1802         iobuf = xmalloc(IOBUF_SIZE);
1803
1804         rmt_ip = 0;
1805         if (fromAddr->u.sa.sa_family == AF_INET) {
1806                 rmt_ip = ntohl(fromAddr->u.sin.sin_addr.s_addr);
1807         }
1808 #if ENABLE_FEATURE_IPV6
1809         if (fromAddr->u.sa.sa_family == AF_INET6
1810          && fromAddr->u.sin6.sin6_addr.s6_addr32[0] == 0
1811          && fromAddr->u.sin6.sin6_addr.s6_addr32[1] == 0
1812          && ntohl(fromAddr->u.sin6.sin6_addr.s6_addr32[2]) == 0xffff)
1813                 rmt_ip = ntohl(fromAddr->u.sin6.sin6_addr.s6_addr32[3]);
1814 #endif
1815         if (ENABLE_FEATURE_HTTPD_CGI || DEBUG || verbose) {
1816                 /* NB: can be NULL (user runs httpd -i by hand?) */
1817                 rmt_ip_str = xmalloc_sockaddr2dotted(&fromAddr->u.sa);
1818         }
1819         if (verbose) {
1820                 /* this trick makes -v logging much simpler */
1821                 if (rmt_ip_str)
1822                         applet_name = rmt_ip_str;
1823                 if (verbose > 2)
1824                         bb_error_msg("connected");
1825         }
1826
1827         /* Install timeout handler. get_line() needs it. */
1828         signal(SIGALRM, send_REQUEST_TIMEOUT_and_exit);
1829
1830         if (!get_line()) /* EOF or error or empty line */
1831                 send_headers_and_exit(HTTP_BAD_REQUEST);
1832
1833         /* Determine type of request (GET/POST) */
1834         urlp = strpbrk(iobuf, " \t");
1835         if (urlp == NULL)
1836                 send_headers_and_exit(HTTP_BAD_REQUEST);
1837         *urlp++ = '\0';
1838 #if ENABLE_FEATURE_HTTPD_CGI
1839         prequest = request_GET;
1840         if (strcasecmp(iobuf, prequest) != 0) {
1841                 prequest = request_HEAD;
1842                 if (strcasecmp(iobuf, prequest) != 0) {
1843                         prequest = "POST";
1844                         if (strcasecmp(iobuf, prequest) != 0)
1845                                 send_headers_and_exit(HTTP_NOT_IMPLEMENTED);
1846                 }
1847         }
1848 #else
1849         if (strcasecmp(iobuf, request_GET) != 0)
1850                 send_headers_and_exit(HTTP_NOT_IMPLEMENTED);
1851 #endif
1852         urlp = skip_whitespace(urlp);
1853         if (urlp[0] != '/')
1854                 send_headers_and_exit(HTTP_BAD_REQUEST);
1855
1856         /* Find end of URL and parse HTTP version, if any */
1857         http_major_version = '0';
1858         IF_FEATURE_HTTPD_PROXY(http_minor_version = '0';)
1859         tptr = strchrnul(urlp, ' ');
1860         /* Is it " HTTP/"? */
1861         if (tptr[0] && strncmp(tptr + 1, HTTP_200, 5) == 0) {
1862                 http_major_version = tptr[6];
1863                 IF_FEATURE_HTTPD_PROXY(http_minor_version = tptr[8];)
1864         }
1865         *tptr = '\0';
1866
1867         /* Copy URL from after "GET "/"POST " to stack-allocated char[] */
1868         urlcopy = alloca((tptr - urlp) + 2 + strlen(index_page));
1869         /*if (urlcopy == NULL)
1870          *      send_headers_and_exit(HTTP_INTERNAL_SERVER_ERROR);*/
1871         strcpy(urlcopy, urlp);
1872         /* NB: urlcopy ptr is never changed after this */
1873
1874         /* Extract url args if present */
1875         g_query = NULL;
1876         tptr = strchr(urlcopy, '?');
1877         if (tptr) {
1878                 *tptr++ = '\0';
1879                 g_query = tptr;
1880         }
1881
1882         /* Decode URL escape sequences */
1883         tptr = decodeString(urlcopy, 0);
1884         if (tptr == NULL)
1885                 send_headers_and_exit(HTTP_BAD_REQUEST);
1886         if (tptr == urlcopy + 1) {
1887                 /* '/' or NUL is encoded */
1888                 send_headers_and_exit(HTTP_NOT_FOUND);
1889         }
1890
1891         /* Canonicalize path */
1892         /* Algorithm stolen from libbb bb_simplify_path(),
1893          * but don't strdup, retain trailing slash, protect root */
1894         urlp = tptr = urlcopy;
1895         do {
1896                 if (*urlp == '/') {
1897                         /* skip duplicate (or initial) slash */
1898                         if (*tptr == '/') {
1899                                 continue;
1900                         }
1901                         if (*tptr == '.') {
1902                                 /* skip extra "/./" */
1903                                 if (tptr[1] == '/' || !tptr[1]) {
1904                                         continue;
1905                                 }
1906                                 /* "..": be careful */
1907                                 if (tptr[1] == '.' && (tptr[2] == '/' || !tptr[2])) {
1908                                         ++tptr;
1909                                         if (urlp == urlcopy) /* protect root */
1910                                                 send_headers_and_exit(HTTP_BAD_REQUEST);
1911                                         while (*--urlp != '/') /* omit previous dir */;
1912                                                 continue;
1913                                 }
1914                         }
1915                 }
1916                 *++urlp = *tptr;
1917         } while (*++tptr);
1918         *++urlp = '\0';       /* terminate after last character */
1919
1920         /* If URL is a directory, add '/' */
1921         if (urlp[-1] != '/') {
1922                 if (is_directory(urlcopy + 1, 1, &sb)) {
1923                         found_moved_temporarily = urlcopy;
1924                 }
1925         }
1926
1927         /* Log it */
1928         if (verbose > 1)
1929                 bb_error_msg("url:%s", urlcopy);
1930
1931         tptr = urlcopy;
1932         ip_allowed = checkPermIP();
1933         while (ip_allowed && (tptr = strchr(tptr + 1, '/')) != NULL) {
1934                 /* have path1/path2 */
1935                 *tptr = '\0';
1936                 if (is_directory(urlcopy + 1, 1, &sb)) {
1937                         /* may have subdir config */
1938                         parse_conf(urlcopy + 1, SUBDIR_PARSE);
1939                         ip_allowed = checkPermIP();
1940                 }
1941                 *tptr = '/';
1942         }
1943
1944 #if ENABLE_FEATURE_HTTPD_PROXY
1945         proxy_entry = find_proxy_entry(urlcopy);
1946         if (proxy_entry)
1947                 header_buf = header_ptr = xmalloc(IOBUF_SIZE);
1948 #endif
1949
1950         if (http_major_version >= '0') {
1951                 /* Request was with "... HTTP/nXXX", and n >= 0 */
1952
1953                 /* Read until blank line for HTTP version specified, else parse immediate */
1954                 while (1) {
1955                         if (!get_line())
1956                                 break; /* EOF or error or empty line */
1957                         if (DEBUG)
1958                                 bb_error_msg("header: '%s'", iobuf);
1959
1960 #if ENABLE_FEATURE_HTTPD_PROXY
1961                         /* We need 2 more bytes for yet another "\r\n" -
1962                          * see near fdprintf(proxy_fd...) further below */
1963                         if (proxy_entry && (header_ptr - header_buf) < IOBUF_SIZE - 2) {
1964                                 int len = strlen(iobuf);
1965                                 if (len > IOBUF_SIZE - (header_ptr - header_buf) - 4)
1966                                         len = IOBUF_SIZE - (header_ptr - header_buf) - 4;
1967                                 memcpy(header_ptr, iobuf, len);
1968                                 header_ptr += len;
1969                                 header_ptr[0] = '\r';
1970                                 header_ptr[1] = '\n';
1971                                 header_ptr += 2;
1972                         }
1973 #endif
1974
1975 #if ENABLE_FEATURE_HTTPD_CGI || ENABLE_FEATURE_HTTPD_PROXY
1976                         /* Try and do our best to parse more lines */
1977                         if ((STRNCASECMP(iobuf, "Content-length:") == 0)) {
1978                                 /* extra read only for POST */
1979                                 if (prequest != request_GET
1980 #if ENABLE_FEATURE_HTTPD_CGI
1981                                  && prequest != request_HEAD
1982 #endif
1983                                 ) {
1984                                         tptr = skip_whitespace(iobuf + sizeof("Content-length:") - 1);
1985                                         if (!tptr[0])
1986                                                 send_headers_and_exit(HTTP_BAD_REQUEST);
1987                                         /* not using strtoul: it ignores leading minus! */
1988                                         length = bb_strtou(tptr, NULL, 10);
1989                                         /* length is "ulong", but we need to pass it to int later */
1990                                         if (errno || length > INT_MAX)
1991                                                 send_headers_and_exit(HTTP_BAD_REQUEST);
1992                                 }
1993                         }
1994 #endif
1995 #if ENABLE_FEATURE_HTTPD_CGI
1996                         else if (STRNCASECMP(iobuf, "Cookie:") == 0) {
1997                                 cookie = xstrdup(skip_whitespace(iobuf + sizeof("Cookie:")-1));
1998                         } else if (STRNCASECMP(iobuf, "Content-Type:") == 0) {
1999                                 content_type = xstrdup(skip_whitespace(iobuf + sizeof("Content-Type:")-1));
2000                         } else if (STRNCASECMP(iobuf, "Referer:") == 0) {
2001                                 referer = xstrdup(skip_whitespace(iobuf + sizeof("Referer:")-1));
2002                         } else if (STRNCASECMP(iobuf, "User-Agent:") == 0) {
2003                                 user_agent = xstrdup(skip_whitespace(iobuf + sizeof("User-Agent:")-1));
2004                         } else if (STRNCASECMP(iobuf, "Host:") == 0) {
2005                                 host = xstrdup(skip_whitespace(iobuf + sizeof("Host:")-1));
2006                         } else if (STRNCASECMP(iobuf, "Accept:") == 0) {
2007                                 http_accept = xstrdup(skip_whitespace(iobuf + sizeof("Accept:")-1));
2008                         } else if (STRNCASECMP(iobuf, "Accept-Language:") == 0) {
2009                                 http_accept_language = xstrdup(skip_whitespace(iobuf + sizeof("Accept-Language:")-1));
2010                         }
2011 #endif
2012 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
2013                         if (STRNCASECMP(iobuf, "Authorization:") == 0) {
2014                                 /* We only allow Basic credentials.
2015                                  * It shows up as "Authorization: Basic <user>:<passwd>" where
2016                                  * "<user>:<passwd>" is base64 encoded.
2017                                  */
2018                                 tptr = skip_whitespace(iobuf + sizeof("Authorization:")-1);
2019                                 if (STRNCASECMP(tptr, "Basic") != 0)
2020                                         continue;
2021                                 tptr += sizeof("Basic")-1;
2022                                 /* decodeBase64() skips whitespace itself */
2023                                 decodeBase64(tptr);
2024                                 authorized = check_user_passwd(urlcopy, tptr);
2025                         }
2026 #endif
2027 #if ENABLE_FEATURE_HTTPD_RANGES
2028                         if (STRNCASECMP(iobuf, "Range:") == 0) {
2029                                 /* We know only bytes=NNN-[MMM] */
2030                                 char *s = skip_whitespace(iobuf + sizeof("Range:")-1);
2031                                 if (strncmp(s, "bytes=", 6) == 0) {
2032                                         s += sizeof("bytes=")-1;
2033                                         range_start = BB_STRTOOFF(s, &s, 10);
2034                                         if (s[0] != '-' || range_start < 0) {
2035                                                 range_start = 0;
2036                                         } else if (s[1]) {
2037                                                 range_end = BB_STRTOOFF(s+1, NULL, 10);
2038                                                 if (errno || range_end < range_start)
2039                                                         range_start = 0;
2040                                         }
2041                                 }
2042                         }
2043 #endif
2044                 } /* while extra header reading */
2045         }
2046
2047         /* We are done reading headers, disable peer timeout */
2048         alarm(0);
2049
2050         if (strcmp(bb_basename(urlcopy), HTTPD_CONF) == 0 || !ip_allowed) {
2051                 /* protect listing [/path]/httpd.conf or IP deny */
2052                 send_headers_and_exit(HTTP_FORBIDDEN);
2053         }
2054
2055 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
2056         /* Case: no "Authorization:" was seen, but page does require passwd.
2057          * Check that with dummy user:pass */
2058         if (authorized < 0)
2059                 authorized = check_user_passwd(urlcopy, ":");
2060         if (!authorized)
2061                 send_headers_and_exit(HTTP_UNAUTHORIZED);
2062 #endif
2063
2064         if (found_moved_temporarily) {
2065                 send_headers_and_exit(HTTP_MOVED_TEMPORARILY);
2066         }
2067
2068 #if ENABLE_FEATURE_HTTPD_PROXY
2069         if (proxy_entry != NULL) {
2070                 int proxy_fd;
2071                 len_and_sockaddr *lsa;
2072
2073                 proxy_fd = socket(AF_INET, SOCK_STREAM, 0);
2074                 if (proxy_fd < 0)
2075                         send_headers_and_exit(HTTP_INTERNAL_SERVER_ERROR);
2076                 lsa = host2sockaddr(proxy_entry->host_port, 80);
2077                 if (lsa == NULL)
2078                         send_headers_and_exit(HTTP_INTERNAL_SERVER_ERROR);
2079                 if (connect(proxy_fd, &lsa->u.sa, lsa->len) < 0)
2080                         send_headers_and_exit(HTTP_INTERNAL_SERVER_ERROR);
2081                 fdprintf(proxy_fd, "%s %s%s%s%s HTTP/%c.%c\r\n",
2082                                 prequest, /* GET or POST */
2083                                 proxy_entry->url_to, /* url part 1 */
2084                                 urlcopy + strlen(proxy_entry->url_from), /* url part 2 */
2085                                 (g_query ? "?" : ""), /* "?" (maybe) */
2086                                 (g_query ? g_query : ""), /* query string (maybe) */
2087                                 http_major_version, http_minor_version);
2088                 header_ptr[0] = '\r';
2089                 header_ptr[1] = '\n';
2090                 header_ptr += 2;
2091                 write(proxy_fd, header_buf, header_ptr - header_buf);
2092                 free(header_buf); /* on the order of 8k, free it */
2093                 /* cgi_io_loop_and_exit needs to have two distinct fds */
2094                 cgi_io_loop_and_exit(proxy_fd, dup(proxy_fd), length);
2095         }
2096 #endif
2097
2098         tptr = urlcopy + 1;      /* skip first '/' */
2099
2100 #if ENABLE_FEATURE_HTTPD_CGI
2101         if (strncmp(tptr, "cgi-bin/", 8) == 0) {
2102                 if (tptr[8] == '\0') {
2103                         /* protect listing "cgi-bin/" */
2104                         send_headers_and_exit(HTTP_FORBIDDEN);
2105                 }
2106                 send_cgi_and_exit(urlcopy, prequest, length, cookie, content_type);
2107         }
2108 #endif
2109
2110         if (urlp[-1] == '/')
2111                 strcpy(urlp, index_page);
2112         if (stat(tptr, &sb) == 0) {
2113 #if ENABLE_FEATURE_HTTPD_CONFIG_WITH_SCRIPT_INTERPR
2114                 char *suffix = strrchr(tptr, '.');
2115                 if (suffix) {
2116                         Htaccess *cur;
2117                         for (cur = script_i; cur; cur = cur->next) {
2118                                 if (strcmp(cur->before_colon + 1, suffix) == 0) {
2119                                         send_cgi_and_exit(urlcopy, prequest, length, cookie, content_type);
2120                                 }
2121                         }
2122                 }
2123 #endif
2124                 file_size = sb.st_size;
2125                 last_mod = sb.st_mtime;
2126         }
2127 #if ENABLE_FEATURE_HTTPD_CGI
2128         else if (urlp[-1] == '/') {
2129                 /* It's a dir URL and there is no index.html
2130                  * Try cgi-bin/index.cgi */
2131                 if (access("/cgi-bin/index.cgi"+1, X_OK) == 0) {
2132                         urlp[0] = '\0';
2133                         g_query = urlcopy;
2134                         send_cgi_and_exit("/cgi-bin/index.cgi", prequest, length, cookie, content_type);
2135                 }
2136         }
2137         /* else fall through to send_file, it errors out if open fails: */
2138
2139         if (prequest != request_GET && prequest != request_HEAD) {
2140                 /* POST for files does not make sense */
2141                 send_headers_and_exit(HTTP_NOT_IMPLEMENTED);
2142         }
2143         send_file_and_exit(tptr,
2144                 (prequest != request_HEAD ? SEND_HEADERS_AND_BODY : SEND_HEADERS)
2145         );
2146 #else
2147         send_file_and_exit(tptr, SEND_HEADERS_AND_BODY);
2148 #endif
2149 }
2150
2151 /*
2152  * The main http server function.
2153  * Given a socket, listen for new connections and farm out
2154  * the processing as a [v]forked process.
2155  * Never returns.
2156  */
2157 #if BB_MMU
2158 static void mini_httpd(int server_socket) NORETURN;
2159 static void mini_httpd(int server_socket)
2160 {
2161         /* NB: it's best to not use xfuncs in this loop before fork().
2162          * Otherwise server may die on transient errors (temporary
2163          * out-of-memory condition, etc), which is Bad(tm).
2164          * Try to do any dangerous calls after fork.
2165          */
2166         while (1) {
2167                 int n;
2168                 len_and_sockaddr fromAddr;
2169
2170                 /* Wait for connections... */
2171                 fromAddr.len = LSA_SIZEOF_SA;
2172                 n = accept(server_socket, &fromAddr.u.sa, &fromAddr.len);
2173
2174                 if (n < 0)
2175                         continue;
2176                 /* set the KEEPALIVE option to cull dead connections */
2177                 setsockopt(n, SOL_SOCKET, SO_KEEPALIVE, &const_int_1, sizeof(const_int_1));
2178
2179                 if (fork() == 0) {
2180                         /* child */
2181                         /* Do not reload config on HUP */
2182                         signal(SIGHUP, SIG_IGN);
2183                         close(server_socket);
2184                         xmove_fd(n, 0);
2185                         xdup2(0, 1);
2186
2187                         handle_incoming_and_exit(&fromAddr);
2188                 }
2189                 /* parent, or fork failed */
2190                 close(n);
2191         } /* while (1) */
2192         /* never reached */
2193 }
2194 #else
2195 static void mini_httpd_nommu(int server_socket, int argc, char **argv) NORETURN;
2196 static void mini_httpd_nommu(int server_socket, int argc, char **argv)
2197 {
2198         char *argv_copy[argc + 2];
2199
2200         argv_copy[0] = argv[0];
2201         argv_copy[1] = (char*)"-i";
2202         memcpy(&argv_copy[2], &argv[1], argc * sizeof(argv[0]));
2203
2204         /* NB: it's best to not use xfuncs in this loop before vfork().
2205          * Otherwise server may die on transient errors (temporary
2206          * out-of-memory condition, etc), which is Bad(tm).
2207          * Try to do any dangerous calls after fork.
2208          */
2209         while (1) {
2210                 int n;
2211                 len_and_sockaddr fromAddr;
2212
2213                 /* Wait for connections... */
2214                 fromAddr.len = LSA_SIZEOF_SA;
2215                 n = accept(server_socket, &fromAddr.u.sa, &fromAddr.len);
2216
2217                 if (n < 0)
2218                         continue;
2219                 /* set the KEEPALIVE option to cull dead connections */
2220                 setsockopt(n, SOL_SOCKET, SO_KEEPALIVE, &const_int_1, sizeof(const_int_1));
2221
2222                 if (vfork() == 0) {
2223                         /* child */
2224                         /* Do not reload config on HUP */
2225                         signal(SIGHUP, SIG_IGN);
2226                         close(server_socket);
2227                         xmove_fd(n, 0);
2228                         xdup2(0, 1);
2229
2230                         /* Run a copy of ourself in inetd mode */
2231                         re_exec(argv_copy);
2232                 }
2233                 /* parent, or vfork failed */
2234                 close(n);
2235         } /* while (1) */
2236         /* never reached */
2237 }
2238 #endif
2239
2240 /*
2241  * Process a HTTP connection on stdin/out.
2242  * Never returns.
2243  */
2244 static void mini_httpd_inetd(void) NORETURN;
2245 static void mini_httpd_inetd(void)
2246 {
2247         len_and_sockaddr fromAddr;
2248
2249         memset(&fromAddr, 0, sizeof(fromAddr));
2250         fromAddr.len = LSA_SIZEOF_SA;
2251         /* NB: can fail if user runs it by hand and types in http cmds */
2252         getpeername(0, &fromAddr.u.sa, &fromAddr.len);
2253         handle_incoming_and_exit(&fromAddr);
2254 }
2255
2256 static void sighup_handler(int sig UNUSED_PARAM)
2257 {
2258         parse_conf(DEFAULT_PATH_HTTPD_CONF, SIGNALED_PARSE);
2259 }
2260
2261 enum {
2262         c_opt_config_file = 0,
2263         d_opt_decode_url,
2264         h_opt_home_httpd,
2265         IF_FEATURE_HTTPD_ENCODE_URL_STR(e_opt_encode_url,)
2266         IF_FEATURE_HTTPD_BASIC_AUTH(    r_opt_realm     ,)
2267         IF_FEATURE_HTTPD_AUTH_MD5(      m_opt_md5       ,)
2268         IF_FEATURE_HTTPD_SETUID(        u_opt_setuid    ,)
2269         p_opt_port      ,
2270         p_opt_inetd     ,
2271         p_opt_foreground,
2272         p_opt_verbose   ,
2273         OPT_CONFIG_FILE = 1 << c_opt_config_file,
2274         OPT_DECODE_URL  = 1 << d_opt_decode_url,
2275         OPT_HOME_HTTPD  = 1 << h_opt_home_httpd,
2276         OPT_ENCODE_URL  = IF_FEATURE_HTTPD_ENCODE_URL_STR((1 << e_opt_encode_url)) + 0,
2277         OPT_REALM       = IF_FEATURE_HTTPD_BASIC_AUTH(    (1 << r_opt_realm     )) + 0,
2278         OPT_MD5         = IF_FEATURE_HTTPD_AUTH_MD5(      (1 << m_opt_md5       )) + 0,
2279         OPT_SETUID      = IF_FEATURE_HTTPD_SETUID(        (1 << u_opt_setuid    )) + 0,
2280         OPT_PORT        = 1 << p_opt_port,
2281         OPT_INETD       = 1 << p_opt_inetd,
2282         OPT_FOREGROUND  = 1 << p_opt_foreground,
2283         OPT_VERBOSE     = 1 << p_opt_verbose,
2284 };
2285
2286
2287 int httpd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
2288 int httpd_main(int argc UNUSED_PARAM, char **argv)
2289 {
2290         int server_socket = server_socket; /* for gcc */
2291         unsigned opt;
2292         char *url_for_decode;
2293         IF_FEATURE_HTTPD_ENCODE_URL_STR(const char *url_for_encode;)
2294         IF_FEATURE_HTTPD_SETUID(const char *s_ugid = NULL;)
2295         IF_FEATURE_HTTPD_SETUID(struct bb_uidgid_t ugid;)
2296         IF_FEATURE_HTTPD_AUTH_MD5(const char *pass;)
2297
2298         INIT_G();
2299
2300 #if ENABLE_LOCALE_SUPPORT
2301         /* Undo busybox.c: we want to speak English in http (dates etc) */
2302         setlocale(LC_TIME, "C");
2303 #endif
2304
2305         home_httpd = xrealloc_getcwd_or_warn(NULL);
2306         /* -v counts, -i implies -f */
2307         opt_complementary = "vv:if";
2308         /* We do not "absolutize" path given by -h (home) opt.
2309          * If user gives relative path in -h,
2310          * $SCRIPT_FILENAME will not be set. */
2311         opt = getopt32(argv, "c:d:h:"
2312                         IF_FEATURE_HTTPD_ENCODE_URL_STR("e:")
2313                         IF_FEATURE_HTTPD_BASIC_AUTH("r:")
2314                         IF_FEATURE_HTTPD_AUTH_MD5("m:")
2315                         IF_FEATURE_HTTPD_SETUID("u:")
2316                         "p:ifv",
2317                         &opt_c_configFile, &url_for_decode, &home_httpd
2318                         IF_FEATURE_HTTPD_ENCODE_URL_STR(, &url_for_encode)
2319                         IF_FEATURE_HTTPD_BASIC_AUTH(, &g_realm)
2320                         IF_FEATURE_HTTPD_AUTH_MD5(, &pass)
2321                         IF_FEATURE_HTTPD_SETUID(, &s_ugid)
2322                         , &bind_addr_or_port
2323                         , &verbose
2324                 );
2325         if (opt & OPT_DECODE_URL) {
2326                 fputs(decodeString(url_for_decode, 1), stdout);
2327                 return 0;
2328         }
2329 #if ENABLE_FEATURE_HTTPD_ENCODE_URL_STR
2330         if (opt & OPT_ENCODE_URL) {
2331                 fputs(encodeString(url_for_encode), stdout);
2332                 return 0;
2333         }
2334 #endif
2335 #if ENABLE_FEATURE_HTTPD_AUTH_MD5
2336         if (opt & OPT_MD5) {
2337                 puts(pw_encrypt(pass, "$1$", 1));
2338                 return 0;
2339         }
2340 #endif
2341 #if ENABLE_FEATURE_HTTPD_SETUID
2342         if (opt & OPT_SETUID) {
2343                 xget_uidgid(&ugid, s_ugid);
2344         }
2345 #endif
2346
2347 #if !BB_MMU
2348         if (!(opt & OPT_FOREGROUND)) {
2349                 bb_daemonize_or_rexec(0, argv); /* don't change current directory */
2350         }
2351 #endif
2352
2353         xchdir(home_httpd);
2354         if (!(opt & OPT_INETD)) {
2355                 signal(SIGCHLD, SIG_IGN);
2356                 server_socket = openServer();
2357 #if ENABLE_FEATURE_HTTPD_SETUID
2358                 /* drop privileges */
2359                 if (opt & OPT_SETUID) {
2360                         if (ugid.gid != (gid_t)-1) {
2361                                 if (setgroups(1, &ugid.gid) == -1)
2362                                         bb_perror_msg_and_die("setgroups");
2363                                 xsetgid(ugid.gid);
2364                         }
2365                         xsetuid(ugid.uid);
2366                 }
2367 #endif
2368         }
2369
2370 #if 0
2371         /* User can do it himself: 'env - PATH="$PATH" httpd'
2372          * We don't do it because we don't want to screw users
2373          * which want to do
2374          * 'env - VAR1=val1 VAR2=val2 httpd'
2375          * and have VAR1 and VAR2 values visible in their CGIs.
2376          * Besides, it is also smaller. */
2377         {
2378                 char *p = getenv("PATH");
2379                 /* env strings themself are not freed, no need to xstrdup(p): */
2380                 clearenv();
2381                 if (p)
2382                         putenv(p - 5);
2383 //              if (!(opt & OPT_INETD))
2384 //                      setenv_long("SERVER_PORT", ???);
2385         }
2386 #endif
2387
2388         parse_conf(DEFAULT_PATH_HTTPD_CONF, FIRST_PARSE);
2389         if (!(opt & OPT_INETD))
2390                 signal(SIGHUP, sighup_handler);
2391
2392         xfunc_error_retval = 0;
2393         if (opt & OPT_INETD)
2394                 mini_httpd_inetd();
2395 #if BB_MMU
2396         if (!(opt & OPT_FOREGROUND))
2397                 bb_daemonize(0); /* don't change current directory */
2398         mini_httpd(server_socket); /* never returns */
2399 #else
2400         mini_httpd_nommu(server_socket, argc, argv); /* never returns */
2401 #endif
2402         /* return 0; */
2403 }