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 server 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 a url-encoded argument while -e encodes in html
  36  * for page display.
  37  *
  38  * httpd.conf has the following format:
  39  *
  40  * A:172.20.         # Allow address from 172.20.0.0/16
  41  * A:10.0.0.0/25     # Allow any address from 10.0.0.0-10.0.0.127
  42  * A:10.0.0.0/255.255.255.128  # Allow any address that previous set
  43  * A:127.0.0.1       # Allow local loopback connections
  44  * D:*               # Deny from other IP connections
  45  * E404:/path/e404.html # /path/e404.html is the 404 (not found) error page
  46  * /cgi-bin:foo:bar  # Require user foo, pwd bar on urls starting with /cgi-bin/
  47  * /adm:admin:setup  # Require user admin, pwd setup on urls starting with /adm/
  48  * /adm:toor:PaSsWd  # or user toor, pwd PaSsWd on urls starting with /adm/
  49  * .au:audio/basic   # additional mime type for audio.au files
  50  * *.php:/path/php   # running cgi.php scripts through an interpreter
  51  *
  52  * A/D may be as a/d or allow/deny - first char case insensitive
  53  * Deny IP rules take precedence over allow rules.
  54  *
  55  *
  56  * The Deny/Allow IP logic:
  57  *
  58  *  - Default is to allow all.  No addresses are denied unless
  59  *         denied with a D: rule.
  60  *  - Order of Deny/Allow rules is significant
  61  *  - Deny rules take precedence over allow rules.
  62  *  - If a deny all rule (D:*) is used it acts as a catch-all for unmatched
  63  *       addresses.
  64  *  - Specification of Allow all (A:*) is a no-op
  65  *
  66  * Example:
  67  *   1. Allow only specified addresses
  68  *     A:172.20          # Allow any address that begins with 172.20.
  69  *     A:10.10.          # Allow any address that begins with 10.10.
  70  *     A:127.0.0.1       # Allow local loopback connections
  71  *     D:*               # Deny from other IP connections
  72  *
  73  *   2. Only deny specified addresses
  74  *     D:1.2.3.        # deny from 1.2.3.0 - 1.2.3.255
  75  *     D:2.3.4.        # deny from 2.3.4.0 - 2.3.4.255
  76  *     A:*             # (optional line added for clarity)
  77  *
  78  * If a sub directory contains a config file it is parsed and merged with
  79  * any existing settings as if it was appended to the original configuration.
  80  *
  81  * subdir paths are relative to the containing subdir and thus cannot
  82  * affect the parent rules.
  83  *
  84  * Note that since the sub dir is parsed in the forked thread servicing the
  85  * subdir http request, any merge is discarded when the process exits.  As a
  86  * result, the subdir settings only have a lifetime of a single request.
  87  *
  88  * Custom error pages can contain an absolute path or be relative to
  89  * 'home_httpd'. Error pages are to be static files (no CGI or script). Error
  90  * page can only be defined in the root configuration file and are not taken
  91  * into account in local (directories) config files.
  92  *
  93  * If -c is not set, an attempt will be made to open the default
  94  * root configuration file.  If -c is set and the file is not found, the
  95  * server exits with an error.
  96  *
  97  */
  98
  99 #include "libbb.h"
 100 #if ENABLE_FEATURE_HTTPD_USE_SENDFILE
 101 #include <sys/sendfile.h>
 102 #endif
 103
 104 //#define DEBUG 1
 105 #define DEBUG 0
 106
 107 /* amount of buffering in a pipe */
 108 #ifndef PIPE_BUF
 109 # define PIPE_BUF 4096
 110 #endif
 111
 112 #define IOBUF_SIZE 8192    /* IO buffer */
 113
 114 #define HEADER_READ_TIMEOUT 60
 115
 116 static const char default_path_httpd_conf[] ALIGN1 = "/etc";
 117 static const char httpd_conf[] ALIGN1 = "httpd.conf";
 118 static const char HTTP_200[] ALIGN1 = "HTTP/1.0 200 OK\r\n";
 119
 120 typedef struct has_next_ptr {
 121         struct has_next_ptr *next;
 122 } has_next_ptr;
 123
 124 /* Must have "next" as a first member */
 125 typedef struct Htaccess {
 126         struct Htaccess *next;
 127         char *after_colon;
 128         char before_colon[1];  /* really bigger, must be last */
 129 } Htaccess;
 130
 131 /* Must have "next" as a first member */
 132 typedef struct Htaccess_IP {
 133         struct Htaccess_IP *next;
 134         unsigned ip;
 135         unsigned mask;
 136         int allow_deny;
 137 } Htaccess_IP;
 138
 139 enum {
 140         HTTP_OK = 200,
 141         HTTP_MOVED_TEMPORARILY = 302,
 142         HTTP_BAD_REQUEST = 400,       /* malformed syntax */
 143         HTTP_UNAUTHORIZED = 401, /* authentication needed, respond with auth hdr */
 144         HTTP_NOT_FOUND = 404,
 145         HTTP_FORBIDDEN = 403,
 146         HTTP_REQUEST_TIMEOUT = 408,
 147         HTTP_NOT_IMPLEMENTED = 501,   /* used for unrecognized requests */
 148         HTTP_INTERNAL_SERVER_ERROR = 500,
 149         HTTP_CONTINUE = 100,
 150 #if 0   /* future use */
 151         HTTP_SWITCHING_PROTOCOLS = 101,
 152         HTTP_CREATED = 201,
 153         HTTP_ACCEPTED = 202,
 154         HTTP_NON_AUTHORITATIVE_INFO = 203,
 155         HTTP_NO_CONTENT = 204,
 156         HTTP_MULTIPLE_CHOICES = 300,
 157         HTTP_MOVED_PERMANENTLY = 301,
 158         HTTP_NOT_MODIFIED = 304,
 159         HTTP_PAYMENT_REQUIRED = 402,
 160         HTTP_BAD_GATEWAY = 502,
 161         HTTP_SERVICE_UNAVAILABLE = 503, /* overload, maintenance */
 162         HTTP_RESPONSE_SETSIZE = 0xffffffff
 163 #endif
 164 };
 165
 166 static const uint16_t http_response_type[] = {
 167         HTTP_OK,
 168         HTTP_MOVED_TEMPORARILY,
 169         HTTP_REQUEST_TIMEOUT,
 170         HTTP_NOT_IMPLEMENTED,
 171 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
 172         HTTP_UNAUTHORIZED,
 173 #endif
 174         HTTP_NOT_FOUND,
 175         HTTP_BAD_REQUEST,
 176         HTTP_FORBIDDEN,
 177         HTTP_INTERNAL_SERVER_ERROR,
 178 #if 0   /* not implemented */
 179         HTTP_CREATED,
 180         HTTP_ACCEPTED,
 181         HTTP_NO_CONTENT,
 182         HTTP_MULTIPLE_CHOICES,
 183         HTTP_MOVED_PERMANENTLY,
 184         HTTP_NOT_MODIFIED,
 185         HTTP_BAD_GATEWAY,
 186         HTTP_SERVICE_UNAVAILABLE,
 187 #endif
 188 };
 189
 190 static const struct {
 191         const char *name;
 192         const char *info;
 193 } http_response[ARRAY_SIZE(http_response_type)] = {
 194         { "OK", NULL },
 195         { "Found", "Directories must end with a slash" }, /* ?? */
 196         { "Request Timeout", "No request appeared within 60 seconds" },
 197         { "Not Implemented", "The requested method is not recognized" },
 198 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
 199         { "Unauthorized", "" },
 200 #endif
 201         { "Not Found", "The requested URL was not found" },
 202         { "Bad Request", "Unsupported method" },
 203         { "Forbidden", ""  },
 204         { "Internal Server Error", "Internal Server Error" },
 205 #if 0   /* not implemented */
 206         { "Created" },
 207         { "Accepted" },
 208         { "No Content" },
 209         { "Multiple Choices" },
 210         { "Moved Permanently" },
 211         { "Not Modified" },
 212         { "Bad Gateway", "" },
 213         { "Service Unavailable", "" },
 214 #endif
 215 };
 216
 217 struct globals {
 218         int verbose;            /* must be int (used by getopt32) */
 219         smallint flg_deny_all;
 220
 221         unsigned rmt_ip;        /* used for IP-based allow/deny rules */
 222         time_t last_mod;
 223         off_t ContentLength;    /* -1 - unknown */
 224         char *rmt_ip_str;       /* for $REMOTE_ADDR and $REMOTE_PORT */
 225         const char *bind_addr_or_port;
 226
 227         const char *g_query;
 228         const char *configFile;
 229         const char *home_httpd;
 230
 231         const char *found_mime_type;
 232         const char *found_moved_temporarily;
 233         Htaccess_IP *ip_a_d;    /* config allow/deny lines */
 234
 235         USE_FEATURE_HTTPD_BASIC_AUTH(const char *g_realm;)
 236         USE_FEATURE_HTTPD_BASIC_AUTH(char *remoteuser;)
 237         USE_FEATURE_HTTPD_CGI(char *referer;)
 238         USE_FEATURE_HTTPD_CGI(char *user_agent;)
 239
 240 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
 241         Htaccess *g_auth;       /* config user:password lines */
 242 #endif
 243 #if ENABLE_FEATURE_HTTPD_CONFIG_WITH_MIME_TYPES
 244         Htaccess *mime_a;       /* config mime types */
 245 #endif
 246 #if ENABLE_FEATURE_HTTPD_CONFIG_WITH_SCRIPT_INTERPR
 247         Htaccess *script_i;     /* config script interpreters */
 248 #endif
 249         char *iobuf;            /* [IOBUF_SIZE] */
 250 #define hdr_buf bb_common_bufsiz1
 251         char *hdr_ptr;
 252         int hdr_cnt;
 253 #if ENABLE_FEATURE_HTTPD_ERROR_PAGES
 254         const char *http_error_page[ARRAY_SIZE(http_response_type)];
 255 #endif
 256 };
 257 #define G (*ptr_to_globals)
 258 #define verbose           (G.verbose          )
 259 #define flg_deny_all      (G.flg_deny_all     )
 260 #define rmt_ip            (G.rmt_ip           )
 261 #define bind_addr_or_port (G.bind_addr_or_port)
 262 #define g_query           (G.g_query          )
 263 #define configFile        (G.configFile       )
 264 #define home_httpd        (G.home_httpd       )
 265 #define found_mime_type   (G.found_mime_type  )
 266 #define found_moved_temporarily (G.found_moved_temporarily)
 267 #define ContentLength     (G.ContentLength    )
 268 #define last_mod          (G.last_mod         )
 269 #define ip_a_d            (G.ip_a_d           )
 270 #define g_realm           (G.g_realm          )
 271 #define remoteuser        (G.remoteuser       )
 272 #define referer           (G.referer          )
 273 #define user_agent        (G.user_agent       )
 274 #define rmt_ip_str        (G.rmt_ip_str       )
 275 #define g_auth            (G.g_auth           )
 276 #define mime_a            (G.mime_a           )
 277 #define script_i          (G.script_i         )
 278 #define iobuf             (G.iobuf            )
 279 #define hdr_ptr           (G.hdr_ptr          )
 280 #define hdr_cnt           (G.hdr_cnt          )
 281 #define http_error_page   (G.http_error_page  )
 282 #define INIT_G() do { \
 283         PTR_TO_GLOBALS = xzalloc(sizeof(G)); \
 284         USE_FEATURE_HTTPD_BASIC_AUTH(g_realm = "Web Server Authentication";) \
 285         bind_addr_or_port = "80"; \
 286         ContentLength = -1; \
 287 } while (0)
 288
 289
 290
 291
 292 #define STRNCASECMP(a, str) strncasecmp((a), (str), sizeof(str)-1)
 293
 294 /* Prototypes */
 295 static void send_file_and_exit(const char *url, int headers) ATTRIBUTE_NORETURN;
 296
 297 static void free_llist(has_next_ptr **pptr)
 298 {
 299         has_next_ptr *cur = *pptr;
 300         while (cur) {
 301                 has_next_ptr *t = cur;
 302                 cur = cur->next;
 303                 free(t);
 304         }
 305         *pptr = NULL;
 306 }
 307
 308 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH \
 309  || ENABLE_FEATURE_HTTPD_CONFIG_WITH_MIME_TYPES \
 310  || ENABLE_FEATURE_HTTPD_CONFIG_WITH_SCRIPT_INTERPR
 311 static ALWAYS_INLINE void free_Htaccess_list(Htaccess **pptr)
 312 {
 313         free_llist((has_next_ptr**)pptr);
 314 }
 315 #endif
 316
 317 static ALWAYS_INLINE void free_Htaccess_IP_list(Htaccess_IP **pptr)
 318 {
 319         free_llist((has_next_ptr**)pptr);
 320 }
 321
 322 /* Returns presumed mask width in bits or < 0 on error.
 323  * Updates strp, stores IP at provided pointer */
 324 static int scan_ip(const char **strp, unsigned *ipp, unsigned char endc)
 325 {
 326         const char *p = *strp;
 327         int auto_mask = 8;
 328         unsigned ip = 0;
 329         int j;
 330
 331         if (*p == '/')
 332                 return -auto_mask;
 333
 334         for (j = 0; j < 4; j++) {
 335                 unsigned octet;
 336
 337                 if ((*p < '0' || *p > '9') && *p != '/' && *p)
 338                         return -auto_mask;
 339                 octet = 0;
 340                 while (*p >= '0' && *p <= '9') {
 341                         octet *= 10;
 342                         octet += *p - '0';
 343                         if (octet > 255)
 344                                 return -auto_mask;
 345                         p++;
 346                 }
 347                 if (*p == '.')
 348                         p++;
 349                 if (*p != '/' && *p)
 350                         auto_mask += 8;
 351                 ip = (ip << 8) | octet;
 352         }
 353         if (*p) {
 354                 if (*p != endc)
 355                         return -auto_mask;
 356                 p++;
 357                 if (*p == '\0')
 358                         return -auto_mask;
 359         }
 360         *ipp = ip;
 361         *strp = p;
 362         return auto_mask;
 363 }
 364
 365 /* Returns 0 on success. Stores IP and mask at provided pointers */
 366 static int scan_ip_mask(const char *str, unsigned *ipp, unsigned *maskp)
 367 {
 368         int i;
 369         unsigned mask;
 370         char *p;
 371
 372         i = scan_ip(&str, ipp, '/');
 373         if (i < 0)
 374                 return i;
 375
 376         if (*str) {
 377                 /* there is /xxx after dotted-IP address */
 378                 i = bb_strtou(str, &p, 10);
 379                 if (*p == '.') {
 380                         /* 'xxx' itself is dotted-IP mask, parse it */
 381                         /* (return 0 (success) only if it has N.N.N.N form) */
 382                         return scan_ip(&str, maskp, '\0') - 32;
 383                 }
 384                 if (*p)
 385                         return -1;
 386         }
 387
 388         if (i > 32)
 389                 return -1;
 390
 391         if (sizeof(unsigned) == 4 && i == 32) {
 392                 /* mask >>= 32 below may not work */
 393                 mask = 0;
 394         } else {
 395                 mask = 0xffffffff;
 396                 mask >>= i;
 397         }
 398         /* i == 0 -> *maskp = 0x00000000
 399          * i == 1 -> *maskp = 0x80000000
 400          * i == 4 -> *maskp = 0xf0000000
 401          * i == 31 -> *maskp = 0xfffffffe
 402          * i == 32 -> *maskp = 0xffffffff */
 403         *maskp = (uint32_t)(~mask);
 404         return 0;
 405 }
 406
 407 /*
 408  * Parse configuration file into in-memory linked list.
 409  *
 410  * The first non-white character is examined to determine if the config line
 411  * is one of the following:
 412  *    .ext:mime/type   # new mime type not compiled into httpd
 413  *    [adAD]:from      # ip address allow/deny, * for wildcard
 414  *    /path:user:pass  # username/password
 415  *    Ennn:error.html  # error page for status nnn
 416  *
 417  * Any previous IP rules are discarded.
 418  * If the flag argument is not SUBDIR_PARSE then all /path and mime rules
 419  * are also discarded.  That is, previous settings are retained if flag is
 420  * SUBDIR_PARSE.
 421  * Error pages are only parsed on the main config file.
 422  *
 423  * path   Path where to look for httpd.conf (without filename).
 424  * flag   Type of the parse request.
 425  */
 426 /* flag */
 427 #define FIRST_PARSE          0
 428 #define SUBDIR_PARSE         1
 429 #define SIGNALED_PARSE       2
 430 #define FIND_FROM_HTTPD_ROOT 3
 431 static void parse_conf(const char *path, int flag)
 432 {
 433         FILE *f;
 434 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
 435         Htaccess *prev;
 436 #endif
 437 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH \
 438  || ENABLE_FEATURE_HTTPD_CONFIG_WITH_MIME_TYPES \
 439  || ENABLE_FEATURE_HTTPD_CONFIG_WITH_SCRIPT_INTERPR
 440         Htaccess *cur;
 441 #endif
 442         const char *cf = configFile;
 443         char buf[160];
 444         char *p0 = NULL;
 445         char *c, *p;
 446         Htaccess_IP *pip;
 447
 448         /* discard old rules */
 449         free_Htaccess_IP_list(&ip_a_d);
 450         flg_deny_all = 0;
 451 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH \
 452  || ENABLE_FEATURE_HTTPD_CONFIG_WITH_MIME_TYPES \
 453  || ENABLE_FEATURE_HTTPD_CONFIG_WITH_SCRIPT_INTERPR
 454         /* retain previous auth and mime config only for subdir parse */
 455         if (flag != SUBDIR_PARSE) {
 456 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
 457                 free_Htaccess_list(&g_auth);
 458 #endif
 459 #if ENABLE_FEATURE_HTTPD_CONFIG_WITH_MIME_TYPES
 460                 free_Htaccess_list(&mime_a);
 461 #endif
 462 #if ENABLE_FEATURE_HTTPD_CONFIG_WITH_SCRIPT_INTERPR
 463                 free_Htaccess_list(&script_i);
 464 #endif
 465         }
 466 #endif
 467
 468         if (flag == SUBDIR_PARSE || cf == NULL) {
 469                 cf = alloca(strlen(path) + sizeof(httpd_conf) + 2);
 470                 if (cf == NULL) {
 471                         if (flag == FIRST_PARSE)
 472                                 bb_error_msg_and_die(bb_msg_memory_exhausted);
 473                         return;
 474                 }
 475                 sprintf((char *)cf, "%s/%s", path, httpd_conf);
 476         }
 477
 478         while ((f = fopen(cf, "r")) == NULL) {
 479                 if (flag == SUBDIR_PARSE || flag == FIND_FROM_HTTPD_ROOT) {
 480                         /* config file not found, no changes to config */
 481                         return;
 482                 }
 483                 if (configFile && flag == FIRST_PARSE) /* if -c option given */
 484                         bb_perror_msg_and_die("%s", cf);
 485                 flag = FIND_FROM_HTTPD_ROOT;
 486                 cf = httpd_conf;
 487         }
 488
 489 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
 490         prev = g_auth;
 491 #endif
 492         /* This could stand some work */
 493         while ((p0 = fgets(buf, sizeof(buf), f)) != NULL) {
 494                 c = NULL;
 495                 for (p = p0; *p0 != '\0' && *p0 != '#'; p0++) {
 496                         if (!isspace(*p0)) {
 497                                 *p++ = *p0;
 498                                 if (*p0 == ':' && c == NULL)
 499                                         c = p;
 500                         }
 501                 }
 502                 *p = '\0';
 503
 504                 /* test for empty or strange line */
 505                 if (c == NULL || *c == '\0')
 506                         continue;
 507                 p0 = buf;
 508                 if (*p0 == 'd')
 509                         *p0 = 'D';
 510                 if (*c == '*') {
 511                         if (*p0 == 'D') {
 512                                 /* memorize deny all */
 513                                 flg_deny_all = 1;
 514                         }
 515                         /* skip default other "word:*" config lines */
 516                         continue;
 517                 }
 518
 519                 if (*p0 == 'a')
 520                         *p0 = 'A';
 521                 if (*p0 == 'A' || *p0 == 'D') {
 522                         /* storing current config IP line */
 523                         pip = xzalloc(sizeof(Htaccess_IP));
 524                         if (pip) {
 525                                 if (scan_ip_mask(c, &(pip->ip), &(pip->mask))) {
 526                                         /* syntax IP{/mask} error detected, protect all */
 527                                         *p0 = 'D';
 528                                         pip->mask = 0;
 529                                 }
 530                                 pip->allow_deny = *p0;
 531                                 if (*p0 == 'D') {
 532                                         /* Deny:from_IP move top */
 533                                         pip->next = ip_a_d;
 534                                         ip_a_d = pip;
 535                                 } else {
 536                                         /* add to bottom A:form_IP config line */
 537                                         Htaccess_IP *prev_IP = ip_a_d;
 538
 539                                         if (prev_IP == NULL) {
 540                                                 ip_a_d = pip;
 541                                         } else {
 542                                                 while (prev_IP->next)
 543                                                         prev_IP = prev_IP->next;
 544                                                 prev_IP->next = pip;
 545                                         }
 546                                 }
 547                         }
 548                         continue;
 549                 }
 550
 551 #if ENABLE_FEATURE_HTTPD_ERROR_PAGES
 552                 if (flag == FIRST_PARSE && *p0 == 'E') {
 553                         int i;
 554                         /* error status code */
 555                         int status = atoi(++p0);
 556                         /* c already points at the character following ':' in parse loop */
 557                         // c = strchr(p0, ':'); c++;
 558                         if (status < HTTP_CONTINUE) {
 559                                 bb_error_msg("config error '%s' in '%s'", buf, cf);
 560                                 continue;
 561                         }
 562
 563                         /* then error page; find matching status */
 564                         for (i = 0; i < ARRAY_SIZE(http_response_type); i++) {
 565                                 if (http_response_type[i] == status) {
 566                                         http_error_page[i] = concat_path_file((*c == '/') ? NULL : home_httpd, c);
 567                                         break;
 568                                 }
 569                         }
 570                         continue;
 571                 }
 572 #endif
 573
 574 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
 575                 if (*p0 == '/') {
 576                         /* make full path from httpd root / current_path / config_line_path */
 577                         cf = (flag == SUBDIR_PARSE ? path : "");
 578                         p0 = malloc(strlen(cf) + (c - buf) + 2 + strlen(c));
 579                         if (p0 == NULL)
 580                                 continue;
 581                         c[-1] = '\0';
 582                         sprintf(p0, "/%s%s", cf, buf);
 583
 584                         /* another call bb_simplify_path */
 585                         cf = p = p0;
 586
 587                         do {
 588                                 if (*p == '/') {
 589                                         if (*cf == '/') {    /* skip duplicate (or initial) slash */
 590                                                 continue;
 591                                         } else if (*cf == '.') {
 592                                                 if (cf[1] == '/' || cf[1] == '\0') { /* remove extra '.' */
 593                                                         continue;
 594                                                 } else if ((cf[1] == '.') && (cf[2] == '/' || cf[2] == '\0')) {
 595                                                         ++cf;
 596                                                         if (p > p0) {
 597                                                                 while (*--p != '/') /* omit previous dir */;
 598                                                         }
 599                                                         continue;
 600                                                 }
 601                                         }
 602                                 }
 603                                 *++p = *cf;
 604                         } while (*++cf);
 605
 606                         if ((p == p0) || (*p != '/')) {      /* not a trailing slash */
 607                                 ++p;                             /* so keep last character */
 608                         }
 609                         *p = '\0';
 610                         sprintf(p0, "%s:%s", p0, c);
 611                 }
 612 #endif
 613
 614 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH \
 615  || ENABLE_FEATURE_HTTPD_CONFIG_WITH_MIME_TYPES \
 616  || ENABLE_FEATURE_HTTPD_CONFIG_WITH_SCRIPT_INTERPR
 617                 /* storing current config line */
 618                 cur = xzalloc(sizeof(Htaccess) + strlen(p0));
 619                 if (cur) {
 620                         cf = strcpy(cur->before_colon, p0);
 621                         c = strchr(cf, ':');
 622                         *c++ = 0;
 623                         cur->after_colon = c;
 624 #if ENABLE_FEATURE_HTTPD_CONFIG_WITH_MIME_TYPES
 625                         if (*cf == '.') {
 626                                 /* config .mime line move top for overwrite previous */
 627                                 cur->next = mime_a;
 628                                 mime_a = cur;
 629                                 continue;
 630                         }
 631 #endif
 632 #if ENABLE_FEATURE_HTTPD_CONFIG_WITH_SCRIPT_INTERPR
 633                         if (*cf == '*' && cf[1] == '.') {
 634                                 /* config script interpreter line move top for overwrite previous */
 635                                 cur->next = script_i;
 636                                 script_i = cur;
 637                                 continue;
 638                         }
 639 #endif
 640 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
 641                         free(p0);
 642                         if (prev == NULL) {
 643                                 /* first line */
 644                                 g_auth = prev = cur;
 645                         } else {
 646                                 /* sort path, if current lenght eq or bigger then move up */
 647                                 Htaccess *prev_hti = g_auth;
 648                                 size_t l = strlen(cf);
 649                                 Htaccess *hti;
 650
 651                                 for (hti = prev_hti; hti; hti = hti->next) {
 652                                         if (l >= strlen(hti->before_colon)) {
 653                                                 /* insert before hti */
 654                                                 cur->next = hti;
 655                                                 if (prev_hti != hti) {
 656                                                         prev_hti->next = cur;
 657                                                 } else {
 658                                                         /* insert as top */
 659                                                         g_auth = cur;
 660                                                 }
 661                                                 break;
 662                                         }
 663                                         if (prev_hti != hti)
 664                                                 prev_hti = prev_hti->next;
 665                                 }
 666                                 if (!hti) {       /* not inserted, add to bottom */
 667                                         prev->next = cur;
 668                                         prev = cur;
 669                                 }
 670                         }
 671 #endif
 672                 }
 673 #endif
 674          }
 675          fclose(f);
 676 }
 677
 678 #if ENABLE_FEATURE_HTTPD_ENCODE_URL_STR
 679 /*
 680  * Given a string, html-encode special characters.
 681  * This is used for the -e command line option to provide an easy way
 682  * for scripts to encode result data without confusing browsers.  The
 683  * returned string pointer is memory allocated by malloc().
 684  *
 685  * Returns a pointer to the encoded string (malloced).
 686  */
 687 static char *encodeString(const char *string)
 688 {
 689         /* take the simple route and encode everything */
 690         /* could possibly scan once to get length.     */
 691         int len = strlen(string);
 692         char *out = xmalloc(len * 6 + 1);
 693         char *p = out;
 694         char ch;
 695
 696         while ((ch = *string++)) {
 697                 // very simple check for what to encode
 698                 if (isalnum(ch)) *p++ = ch;
 699                 else p += sprintf(p, "&#%d;", (unsigned char) ch);
 700         }
 701         *p = '\0';
 702         return out;
 703 }
 704 #endif          /* FEATURE_HTTPD_ENCODE_URL_STR */
 705
 706 /*
 707  * Given a URL encoded string, convert it to plain ascii.
 708  * Since decoding always makes strings smaller, the decode is done in-place.
 709  * Thus, callers should strdup() the argument if they do not want the
 710  * argument modified.  The return is the original pointer, allowing this
 711  * function to be easily used as arguments to other functions.
 712  *
 713  * string    The first string to decode.
 714  * option_d  1 if called for httpd -d
 715  *
 716  * Returns a pointer to the decoded string (same as input).
 717  */
 718 static unsigned hex_to_bin(unsigned char c)
 719 {
 720         unsigned v = c | 0x20; /* lowercase */
 721         v = v - '0';
 722         if (v <= 9)
 723                 return v;
 724         v = v + ('0' - 'a');
 725         if (v <= 5)
 726                 return v + 10;
 727         return ~0;
 728 }
 729 /* For testing:
 730 void t(char c) { printf("'%c' %u\n", c, hex_to_bin(c)); }
 731 int main() { t('0'); t('9'); t('A'); t('F'); t('a'); t('f');
 732 t('0'-1); t('9'+1); t('A'-1); t('F'+1); t('a'-1); t('f'+1); return 0; }
 733 */
 734 static char *decodeString(char *orig, int option_d)
 735 {
 736         /* note that decoded string is always shorter than original */
 737         char *string = orig;
 738         char *ptr = string;
 739         char c;
 740
 741         while ((c = *ptr++) != '\0') {
 742                 unsigned v;
 743
 744                 if (option_d && c == '+') {
 745                         *string++ = ' ';
 746                         continue;
 747                 }
 748                 if (c != '%') {
 749                         *string++ = c;
 750                         continue;
 751                 }
 752                 v = hex_to_bin(ptr[0]);
 753                 if (v > 15) {
 754  bad_hex:
 755                         if (!option_d)
 756                                 return NULL;
 757                         *string++ = '%';
 758                         continue;
 759                 }
 760                 v = (v * 16) | hex_to_bin(ptr[1]);
 761                 if (v > 255)
 762                         goto bad_hex;
 763                 if (!option_d && (v == '/' || v == '\0')) {
 764                         /* caller takes it as indication of invalid
 765                          * (dangerous wrt exploits) chars */
 766                         return orig + 1;
 767                 }
 768                 *string++ = v;
 769                 ptr += 2;
 770         }
 771         *string = '\0';
 772         return orig;
 773 }
 774
 775 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
 776 /*
 777  * Decode a base64 data stream as per rfc1521.
 778  * Note that the rfc states that non base64 chars are to be ignored.
 779  * Since the decode always results in a shorter size than the input,
 780  * it is OK to pass the input arg as an output arg.
 781  * Parameter: a pointer to a base64 encoded string.
 782  * Decoded data is stored in-place.
 783  */
 784 static void decodeBase64(char *Data)
 785 {
 786         const unsigned char *in = (const unsigned char *)Data;
 787         /* The decoded size will be at most 3/4 the size of the encoded */
 788         unsigned ch = 0;
 789         int i = 0;
 790
 791         while (*in) {
 792                 int t = *in++;
 793
 794                 if (t >= '0' && t <= '9')
 795                         t = t - '0' + 52;
 796                 else if (t >= 'A' && t <= 'Z')
 797                         t = t - 'A';
 798                 else if (t >= 'a' && t <= 'z')
 799                         t = t - 'a' + 26;
 800                 else if (t == '+')
 801                         t = 62;
 802                 else if (t == '/')
 803                         t = 63;
 804                 else if (t == '=')
 805                         t = 0;
 806                 else
 807                         continue;
 808
 809                 ch = (ch << 6) | t;
 810                 i++;
 811                 if (i == 4) {
 812                         *Data++ = (char) (ch >> 16);
 813                         *Data++ = (char) (ch >> 8);
 814                         *Data++ = (char) ch;
 815                         i = 0;
 816                 }
 817         }
 818         *Data = '\0';
 819 }
 820 #endif
 821
 822 /*
 823  * Create a listen server socket on the designated port.
 824  */
 825 static int openServer(void)
 826 {
 827         int n = bb_strtou(bind_addr_or_port, NULL, 10);
 828         if (!errno && n && n <= 0xffff)
 829                 n = create_and_bind_stream_or_die(NULL, n);
 830         else
 831                 n = create_and_bind_stream_or_die(bind_addr_or_port, 80);
 832         xlisten(n, 9);
 833         return n;
 834 }
 835
 836 /*
 837  * Log the connection closure and exit.
 838  */
 839 static void log_and_exit(void) ATTRIBUTE_NORETURN;
 840 static void log_and_exit(void)
 841 {
 842         /* Paranoia. IE said to be buggy. It may send some extra data
 843          * or be confused by us just exiting without SHUT_WR. Oh well. */
 844         shutdown(1, SHUT_WR);
 845         ndelay_on(0);
 846         while (read(0, iobuf, IOBUF_SIZE) > 0)
 847                 continue;
 848
 849         if (verbose > 2)
 850                 bb_error_msg("closed");
 851         _exit(xfunc_error_retval);
 852 }
 853
 854 /*
 855  * Create and send HTTP response headers.
 856  * The arguments are combined and sent as one write operation.  Note that
 857  * IE will puke big-time if the headers are not sent in one packet and the
 858  * second packet is delayed for any reason.
 859  * responseNum - the result code to send.
 860  */
 861 static void send_headers(int responseNum)
 862 {
 863         static const char RFC1123FMT[] ALIGN1 = "%a, %d %b %Y %H:%M:%S GMT";
 864
 865         const char *responseString = "";
 866         const char *infoString = NULL;
 867         const char *mime_type;
 868 #if ENABLE_FEATURE_HTTPD_ERROR_PAGES
 869         const char *error_page = 0;
 870 #endif
 871         unsigned i;
 872         time_t timer = time(0);
 873         char tmp_str[80];
 874         int len;
 875
 876         for (i = 0; i < ARRAY_SIZE(http_response_type); i++) {
 877                 if (http_response_type[i] == responseNum) {
 878                         responseString = http_response[i].name;
 879                         infoString = http_response[i].info;
 880 #if ENABLE_FEATURE_HTTPD_ERROR_PAGES
 881                         error_page = http_error_page[i];
 882 #endif
 883                         break;
 884                 }
 885         }
 886         /* error message is HTML */
 887         mime_type = responseNum == HTTP_OK ?
 888                                 found_mime_type : "text/html";
 889
 890         if (verbose)
 891                 bb_error_msg("response:%u", responseNum);
 892
 893         /* emit the current date */
 894         strftime(tmp_str, sizeof(tmp_str), RFC1123FMT, gmtime(&timer));
 895         len = sprintf(iobuf,
 896                         "HTTP/1.0 %d %s\r\nContent-type: %s\r\n"
 897                         "Date: %s\r\nConnection: close\r\n",
 898                         responseNum, responseString, mime_type, tmp_str);
 899
 900 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
 901         if (responseNum == HTTP_UNAUTHORIZED) {
 902                 len += sprintf(iobuf + len,
 903                                 "WWW-Authenticate: Basic realm=\"%s\"\r\n",
 904                                 g_realm);
 905         }
 906 #endif
 907         if (responseNum == HTTP_MOVED_TEMPORARILY) {
 908                 len += sprintf(iobuf + len, "Location: %s/%s%s\r\n",
 909                                 found_moved_temporarily,
 910                                 (g_query ? "?" : ""),
 911                                 (g_query ? g_query : ""));
 912         }
 913
 914 #if ENABLE_FEATURE_HTTPD_ERROR_PAGES
 915         if (error_page && !access(error_page, R_OK)) {
 916                 strcat(iobuf, "\r\n");
 917                 len += 2;
 918
 919                 if (DEBUG)
 920                         fprintf(stderr, "headers: '%s'\n", iobuf);
 921                 full_write(1, iobuf, len);
 922                 if (DEBUG)
 923                         fprintf(stderr, "writing error page: '%s'\n", error_page);
 924                 return send_file_and_exit(error_page, FALSE);
 925         }
 926 #endif
 927
 928         if (ContentLength != -1) {    /* file */
 929                 strftime(tmp_str, sizeof(tmp_str), RFC1123FMT, gmtime(&last_mod));
 930                 len += sprintf(iobuf + len, "Last-Modified: %s\r\n%s %"OFF_FMT"d\r\n",
 931                         tmp_str, "Content-length:", ContentLength);
 932         }
 933         iobuf[len++] = '\r';
 934         iobuf[len++] = '\n';
 935         if (infoString) {
 936                 len += sprintf(iobuf + len,
 937                                 "<HTML><HEAD><TITLE>%d %s</TITLE></HEAD>\n"
 938                                 "<BODY><H1>%d %s</H1>\n%s\n</BODY></HTML>\n",
 939                                 responseNum, responseString,
 940                                 responseNum, responseString, infoString);
 941         }
 942         if (DEBUG)
 943                 fprintf(stderr, "headers: '%s'\n", iobuf);
 944         if (full_write(1, iobuf, len) != len) {
 945                 if (verbose > 1)
 946                         bb_perror_msg("error");
 947                 log_and_exit();
 948         }
 949 }
 950
 951 static void send_headers_and_exit(int responseNum) ATTRIBUTE_NORETURN;
 952 static void send_headers_and_exit(int responseNum)
 953 {
 954         send_headers(responseNum);
 955         log_and_exit();
 956 }
 957
 958 /*
 959  * Read from the socket until '\n' or EOF. '\r' chars are removed.
 960  * '\n' is replaced with NUL.
 961  * Return number of characters read or 0 if nothing is read
 962  * ('\r' and '\n' are not counted).
 963  * Data is returned in iobuf.
 964  */
 965 static int get_line(void)
 966 {
 967         int count = 0;
 968         char c;
 969
 970         while (1) {
 971                 if (hdr_cnt <= 0) {
 972                         hdr_cnt = safe_read(0, hdr_buf, sizeof(hdr_buf));
 973                         if (hdr_cnt <= 0)
 974                                 break;
 975                         hdr_ptr = hdr_buf;
 976                 }
 977                 iobuf[count] = c = *hdr_ptr++;
 978                 hdr_cnt--;
 979
 980                 if (c == '\r')
 981                         continue;
 982                 if (c == '\n') {
 983                         iobuf[count] = '\0';
 984                         return count;
 985                 }
 986                 if (count < (IOBUF_SIZE - 1))      /* check overflow */
 987                         count++;
 988         }
 989         return count;
 990 }
 991
 992 #if ENABLE_FEATURE_HTTPD_CGI
 993 static void setenv1(const char *name, const char *value)
 994 {
 995         setenv(name, value ? value : "", 1);
 996 }
 997
 998 /*
 999  * Spawn CGI script, forward CGI's stdin/out <=> network
1000  *
1001  * Environment variables are set up and the script is invoked with pipes
1002  * for stdin/stdout.  If a post is being done the script is fed the POST
1003  * data in addition to setting the QUERY_STRING variable (for GETs or POSTs).
1004  *
1005  * Parameters:
1006  * const char *url              The requested URL (with leading /).
1007  * int bodyLen                  Length of the post body.
1008  * const char *cookie           For set HTTP_COOKIE.
1009  * const char *content_type     For set CONTENT_TYPE.
1010  */
1011 static void send_cgi_and_exit(
1012                 const char *url,
1013                 const char *request,
1014                 int bodyLen,
1015                 const char *cookie,
1016                 const char *content_type) ATTRIBUTE_NORETURN;
1017 static void send_cgi_and_exit(
1018                 const char *url,
1019                 const char *request,
1020                 int bodyLen,
1021                 const char *cookie,
1022                 const char *content_type)
1023 {
1024         struct { int rd; int wr; } fromCgi;  /* CGI -> httpd pipe */
1025         struct { int rd; int wr; } toCgi;    /* httpd -> CGI pipe */
1026         char *fullpath;
1027         char *script;
1028         char *purl;
1029         int buf_count;
1030         int status;
1031         int pid = 0;
1032
1033         /*
1034          * We are mucking with environment _first_ and then vfork/exec,
1035          * this allows us to use vfork safely. Parent don't care about
1036          * these environment changes anyway.
1037          */
1038
1039         /*
1040          * Find PATH_INFO.
1041          */
1042         purl = xstrdup(url);
1043         script = purl;
1044         while ((script = strchr(script + 1, '/')) != NULL) {
1045                 /* have script.cgi/PATH_INFO or dirs/script.cgi[/PATH_INFO] */
1046                 struct stat sb;
1047
1048                 *script = '\0';
1049                 if (!is_directory(purl + 1, 1, &sb)) {
1050                         /* not directory, found script.cgi/PATH_INFO */
1051                         *script = '/';
1052                         break;
1053                 }
1054                 *script = '/';          /* is directory, find next '/' */
1055         }
1056         setenv1("PATH_INFO", script);   /* set /PATH_INFO or "" */
1057         setenv1("REQUEST_METHOD", request);
1058         if (g_query) {
1059                 putenv(xasprintf("%s=%s?%s", "REQUEST_URI", purl, g_query));
1060         } else {
1061                 setenv1("REQUEST_URI", purl);
1062         }
1063         if (script != NULL)
1064                 *script = '\0';         /* cut off /PATH_INFO */
1065
1066         /* SCRIPT_FILENAME required by PHP in CGI mode */
1067         fullpath = concat_path_file(home_httpd, purl);
1068         setenv1("SCRIPT_FILENAME", fullpath);
1069         /* set SCRIPT_NAME as full path: /cgi-bin/dirs/script.cgi */
1070         setenv1("SCRIPT_NAME", purl);
1071         /* http://hoohoo.ncsa.uiuc.edu/cgi/env.html:
1072          * QUERY_STRING: The information which follows the ? in the URL
1073          * which referenced this script. This is the query information.
1074          * It should not be decoded in any fashion. This variable
1075          * should always be set when there is query information,
1076          * regardless of command line decoding. */
1077         /* (Older versions of bbox seem to do some decoding) */
1078         setenv1("QUERY_STRING", g_query);
1079         putenv((char*)"SERVER_SOFTWARE=busybox httpd/"BB_VER);
1080         putenv((char*)"SERVER_PROTOCOL=HTTP/1.0");
1081         putenv((char*)"GATEWAY_INTERFACE=CGI/1.1");
1082         /* Having _separate_ variables for IP and port defeats
1083          * the purpose of having socket abstraction. Which "port"
1084          * are you using on Unix domain socket?
1085          * IOW - REMOTE_PEER="1.2.3.4:56" makes much more sense.
1086          * Oh well... */
1087         {
1088                 char *p = rmt_ip_str ? rmt_ip_str : (char*)"";
1089                 char *cp = strrchr(p, ':');
1090                 if (ENABLE_FEATURE_IPV6 && cp && strchr(cp, ']'))
1091                         cp = NULL;
1092                 if (cp) *cp = '\0'; /* delete :PORT */
1093                 setenv1("REMOTE_ADDR", p);
1094                 if (cp) {
1095                         *cp = ':';
1096 #if ENABLE_FEATURE_HTTPD_SET_REMOTE_PORT_TO_ENV
1097                         setenv1("REMOTE_PORT", cp + 1);
1098 #endif
1099                 }
1100         }
1101         setenv1("HTTP_USER_AGENT", user_agent);
1102         if (bodyLen)
1103                 putenv(xasprintf("CONTENT_LENGTH=%d", bodyLen));
1104         if (cookie)
1105                 setenv1("HTTP_COOKIE", cookie);
1106         if (content_type)
1107                 setenv1("CONTENT_TYPE", content_type);
1108 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
1109         if (remoteuser) {
1110                 setenv1("REMOTE_USER", remoteuser);
1111                 putenv((char*)"AUTH_TYPE=Basic");
1112         }
1113 #endif
1114         if (referer)
1115                 setenv1("HTTP_REFERER", referer);
1116
1117         xpipe(&fromCgi.rd);
1118         xpipe(&toCgi.rd);
1119
1120         pid = vfork();
1121         if (pid < 0) {
1122                 /* TODO: log perror? */
1123                 log_and_exit();
1124         }
1125
1126         if (!pid) {
1127                 /* Child process */
1128                 xfunc_error_retval = 242;
1129
1130                 xmove_fd(toCgi.rd, 0);  /* replace stdin with the pipe */
1131                 xmove_fd(fromCgi.wr, 1);  /* replace stdout with the pipe */
1132                 close(fromCgi.rd);
1133                 close(toCgi.wr);
1134                 /* User seeing stderr output can be a security problem.
1135                  * If CGI really wants that, it can always do dup itself. */
1136                 /* dup2(1, 2); */
1137
1138                 /* script must have absolute path */
1139                 script = strrchr(fullpath, '/');
1140                 if (!script)
1141                         goto error_execing_cgi;
1142                 *script = '\0';
1143                 /* chdiring to script's dir */
1144                 if (chdir(fullpath) == 0) {
1145                         char *argv[2];
1146 #if ENABLE_FEATURE_HTTPD_CONFIG_WITH_SCRIPT_INTERPR
1147                         char *interpr = NULL;
1148                         char *suffix = strrchr(purl, '.');
1149
1150                         if (suffix) {
1151                                 Htaccess *cur;
1152                                 for (cur = script_i; cur; cur = cur->next) {
1153                                         if (strcmp(cur->before_colon + 1, suffix) == 0) {
1154                                                 interpr = cur->after_colon;
1155                                                 break;
1156                                         }
1157                                 }
1158                         }
1159 #endif
1160                         *script = '/';
1161                         /* set argv[0] to name without path */
1162                         argv[0] = (char*)bb_basename(purl);
1163                         argv[1] = NULL;
1164 #if ENABLE_FEATURE_HTTPD_CONFIG_WITH_SCRIPT_INTERPR
1165                         if (interpr)
1166                                 execv(interpr, argv);
1167                         else
1168 #endif
1169                                 execv(fullpath, argv);
1170                 }
1171  error_execing_cgi:
1172                 /* send to stdout
1173                  * (we are CGI here, our stdout is pumped to the net) */
1174                 send_headers_and_exit(HTTP_NOT_FOUND);
1175         } /* end child */
1176
1177         /* Parent process */
1178
1179         /* First, restore variables possibly changed by child */
1180         xfunc_error_retval = 0;
1181
1182         /* Prepare for pumping data.
1183          * iobuf is used for CGI -> network data,
1184          * hdr_buf is for network -> CGI data (POSTDATA) */
1185         buf_count = 0;
1186         close(fromCgi.wr);
1187         close(toCgi.rd);
1188
1189         /* If CGI dies, we still want to correctly finish reading its output
1190          * and send it to the peer. So please no SIGPIPEs! */
1191         signal(SIGPIPE, SIG_IGN);
1192
1193         /* This loop still looks messy. What is an exit criteria?
1194          * "CGI's output closed"? Or "CGI has exited"?
1195          * What to do if CGI has closed both input and output, but
1196          * didn't exit? etc... */
1197
1198         /* NB: breaking out of this loop jumps to log_and_exit() */
1199         while (1) {
1200                 fd_set readSet;
1201                 fd_set writeSet;
1202                 int nfound;
1203                 int count;
1204
1205                 FD_ZERO(&readSet);
1206                 FD_ZERO(&writeSet);
1207                 FD_SET(fromCgi.rd, &readSet);
1208                 if (bodyLen > 0 || hdr_cnt > 0) {
1209                         FD_SET(toCgi.wr, &writeSet);
1210                         nfound = toCgi.wr > fromCgi.rd ? toCgi.wr : fromCgi.rd;
1211                         if (hdr_cnt <= 0)
1212                                 FD_SET(0, &readSet);
1213                         /* Now wait on the set of sockets! */
1214                         nfound = select(nfound + 1, &readSet, &writeSet, NULL, NULL);
1215                 } else {
1216                         if (!bodyLen) {
1217                                 close(toCgi.wr); /* no more POST data to CGI */
1218                                 bodyLen = -1;
1219                         }
1220                         nfound = select(fromCgi.rd + 1, &readSet, NULL, NULL, NULL);
1221                 }
1222
1223                 if (nfound <= 0) {
1224                         if (waitpid(pid, &status, WNOHANG) <= 0) {
1225                                 /* Weird. CGI didn't exit and no fd's
1226                                  * are ready, yet select returned?! */
1227                                 continue;
1228                         }
1229                         close(fromCgi.rd);
1230                         if (DEBUG && WIFEXITED(status))
1231                                 bb_error_msg("CGI exited, status=%d", WEXITSTATUS(status));
1232                         if (DEBUG && WIFSIGNALED(status))
1233                                 bb_error_msg("CGI killed, signal=%d", WTERMSIG(status));
1234                         break;
1235                 }
1236
1237                 if (hdr_cnt > 0 && FD_ISSET(toCgi.wr, &writeSet)) {
1238                         /* Have data from peer and can write to CGI */
1239                         count = safe_write(toCgi.wr, hdr_ptr, hdr_cnt);
1240                         /* Doesn't happen, we dont use nonblocking IO here
1241                          *if (count < 0 && errno == EAGAIN) {
1242                          *      ...
1243                          *} else */
1244                         if (count > 0) {
1245                                 hdr_ptr += count;
1246                                 hdr_cnt -= count;
1247                         } else {
1248                                 hdr_cnt = bodyLen = 0; /* EOF/broken pipe to CGI */
1249                         }
1250                 } else if (bodyLen > 0 && hdr_cnt == 0
1251                  && FD_ISSET(0, &readSet)
1252                 ) {
1253                         /* We expect data, prev data portion is eaten by CGI
1254                          * and there *is* data to read from the peer
1255                          * (POSTDATA?) */
1256                         count = bodyLen > (int)sizeof(hdr_buf) ? (int)sizeof(hdr_buf) : bodyLen;
1257                         count = safe_read(0, hdr_buf, count);
1258                         if (count > 0) {
1259                                 hdr_cnt = count;
1260                                 hdr_ptr = hdr_buf;
1261                                 bodyLen -= count;
1262                         } else {
1263                                 bodyLen = 0; /* closed */
1264                         }
1265                 }
1266
1267 #define PIPESIZE PIPE_BUF
1268 #if PIPESIZE >= IOBUF_SIZE
1269 # error "PIPESIZE >= IOBUF_SIZE"
1270 #endif
1271                 if (FD_ISSET(fromCgi.rd, &readSet)) {
1272                         /* There is something to read from CGI */
1273                         char *rbuf = iobuf;
1274
1275                         /* Are we still buffering CGI output? */
1276                         if (buf_count >= 0) {
1277                                 /* HTTP_200[] has single "\r\n" at the end.
1278                                  * According to http://hoohoo.ncsa.uiuc.edu/cgi/out.html,
1279                                  * CGI scripts MUST send their own header terminated by
1280                                  * empty line, then data. That's why we have only one
1281                                  * <cr><lf> pair here. We will output "200 OK" line
1282                                  * if needed, but CGI still has to provide blank line
1283                                  * between header and body */
1284
1285                                 /* Must use safe_read, not full_read, because
1286                                  * CGI may output a few first bytes and then wait
1287                                  * for POSTDATA without closing stdout.
1288                                  * With full_read we may wait here forever. */
1289                                 count = safe_read(fromCgi.rd, rbuf + buf_count, PIPESIZE - 8);
1290                                 if (count <= 0) {
1291                                         /* eof (or error) and there was no "HTTP",
1292                                          * so write it, then write received data */
1293                                         if (buf_count) {
1294                                                 full_write(1, HTTP_200, sizeof(HTTP_200)-1);
1295                                                 full_write(1, rbuf, buf_count);
1296                                         }
1297                                         break; /* CGI stdout is closed, exiting */
1298                                 }
1299                                 buf_count += count;
1300                                 count = 0;
1301                                 /* "Status" header format is: "Status: 302 Redirected\r\n" */
1302                                 if (buf_count >= 8 && memcmp(rbuf, "Status: ", 8) == 0) {
1303                                         /* send "HTTP/1.0 " */
1304                                         if (full_write(1, HTTP_200, 9) != 9)
1305                                                 break;
1306                                         rbuf += 8; /* skip "Status: " */
1307                                         count = buf_count - 8;
1308                                         buf_count = -1; /* buffering off */
1309                                 } else if (buf_count >= 4) {
1310                                         /* Did CGI add "HTTP"? */
1311                                         if (memcmp(rbuf, HTTP_200, 4) != 0) {
1312                                                 /* there is no "HTTP", do it ourself */
1313                                                 if (full_write(1, HTTP_200, sizeof(HTTP_200)-1) != sizeof(HTTP_200)-1)
1314                                                         break;
1315                                         }
1316                                         /* Commented out:
1317                                         if (!strstr(rbuf, "ontent-")) {
1318                                                 full_write(s, "Content-type: text/plain\r\n\r\n", 28);
1319                                         }
1320                                          * Counter-example of valid CGI without Content-type:
1321                                          * echo -en "HTTP/1.0 302 Found\r\n"
1322                                          * echo -en "Location: http://www.busybox.net\r\n"
1323                                          * echo -en "\r\n"
1324                                          */
1325                                         count = buf_count;
1326                                         buf_count = -1; /* buffering off */
1327                                 }
1328                         } else {
1329                                 count = safe_read(fromCgi.rd, rbuf, PIPESIZE);
1330                                 if (count <= 0)
1331                                         break;  /* eof (or error) */
1332                         }
1333                         if (full_write(1, rbuf, count) != count)
1334                                 break;
1335                         if (DEBUG)
1336                                 fprintf(stderr, "cgi read %d bytes: '%.*s'\n", count, count, rbuf);
1337                 } /* if (FD_ISSET(fromCgi.rd)) */
1338         } /* while (1) */
1339         log_and_exit();
1340 }
1341 #endif          /* FEATURE_HTTPD_CGI */
1342
1343 /*
1344  * Send a file response to a HTTP request, and exit
1345  *
1346  * Parameters:
1347  * const char *url    The requested URL (with leading /).
1348  * headers            Don't send headers before if FALSE.
1349  */
1350 static void send_file_and_exit(const char *url, int headers)
1351 {
1352         static const char *const suffixTable[] = {
1353         /* Warning: shorter equivalent suffix in one line must be first */
1354                 ".htm.html", "text/html",
1355                 ".jpg.jpeg", "image/jpeg",
1356                 ".gif",      "image/gif",
1357                 ".png",      "image/png",
1358                 ".txt.h.c.cc.cpp", "text/plain",
1359                 ".css",      "text/css",
1360                 ".wav",      "audio/wav",
1361                 ".avi",      "video/x-msvideo",
1362                 ".qt.mov",   "video/quicktime",
1363                 ".mpe.mpeg", "video/mpeg",
1364                 ".mid.midi", "audio/midi",
1365                 ".mp3",      "audio/mpeg",
1366 #if 0                        /* unpopular */
1367                 ".au",       "audio/basic",
1368                 ".pac",      "application/x-ns-proxy-autoconfig",
1369                 ".vrml.wrl", "model/vrml",
1370 #endif
1371                 NULL
1372         };
1373
1374         char *suffix;
1375         int f;
1376         const char *const *table;
1377         const char *try_suffix;
1378         ssize_t count;
1379 #if ENABLE_FEATURE_HTTPD_USE_SENDFILE
1380         off_t offset = 0;
1381 #endif
1382
1383         suffix = strrchr(url, '.');
1384
1385         /* If not found, set default as "application/octet-stream";  */
1386         found_mime_type = "application/octet-stream";
1387         if (suffix) {
1388 #if ENABLE_FEATURE_HTTPD_CONFIG_WITH_MIME_TYPES
1389                 Htaccess *cur;
1390 #endif
1391                 for (table = suffixTable; *table; table += 2) {
1392                         try_suffix = strstr(table[0], suffix);
1393                         if (try_suffix) {
1394                                 try_suffix += strlen(suffix);
1395                                 if (*try_suffix == '\0' || *try_suffix == '.') {
1396                                         found_mime_type = table[1];
1397                                         break;
1398                                 }
1399                         }
1400                 }
1401 #if ENABLE_FEATURE_HTTPD_CONFIG_WITH_MIME_TYPES
1402                 for (cur = mime_a; cur; cur = cur->next) {
1403                         if (strcmp(cur->before_colon, suffix) == 0) {
1404                                 found_mime_type = cur->after_colon;
1405                                 break;
1406                         }
1407                 }
1408 #endif
1409         }
1410
1411         if (DEBUG)
1412                 bb_error_msg("sending file '%s' content-type: %s",
1413                         url, found_mime_type);
1414
1415         f = open(url, O_RDONLY);
1416         if (f < 0) {
1417                 if (DEBUG)
1418                         bb_perror_msg("cannot open '%s'", url);
1419                 if (headers)
1420                         send_headers_and_exit(HTTP_NOT_FOUND);
1421         }
1422
1423         if (headers)
1424                 send_headers(HTTP_OK);
1425
1426         /* If you want to know about EPIPE below
1427          * (happens if you abort downloads from local httpd): */
1428         signal(SIGPIPE, SIG_IGN);
1429
1430 #if ENABLE_FEATURE_HTTPD_USE_SENDFILE
1431         do {
1432                 /* byte count (3rd arg) is rounded down to 64k */
1433                 count = sendfile(1, f, &offset, MAXINT(ssize_t) - 0xffff);
1434                 if (count < 0) {
1435                         if (offset == 0)
1436                                 goto fallback;
1437                         goto fin;
1438                 }
1439         } while (count > 0);
1440         log_and_exit();
1441
1442  fallback:
1443 #endif
1444         while ((count = safe_read(f, iobuf, IOBUF_SIZE)) > 0) {
1445                 ssize_t n = count;
1446                 count = full_write(1, iobuf, count);
1447                 if (count != n)
1448                         break;
1449         }
1450 #if ENABLE_FEATURE_HTTPD_USE_SENDFILE
1451  fin:
1452 #endif
1453         if (count < 0 && verbose > 1)
1454                 bb_perror_msg("error");
1455         log_and_exit();
1456 }
1457
1458 static int checkPermIP(void)
1459 {
1460         Htaccess_IP *cur;
1461
1462         /* This could stand some work */
1463         for (cur = ip_a_d; cur; cur = cur->next) {
1464 #if DEBUG
1465                 fprintf(stderr,
1466                         "checkPermIP: '%s' ? '%u.%u.%u.%u/%u.%u.%u.%u'\n",
1467                         rmt_ip_str,
1468                         (unsigned char)(cur->ip >> 24),
1469                         (unsigned char)(cur->ip >> 16),
1470                         (unsigned char)(cur->ip >> 8),
1471                         (unsigned char)(cur->ip),
1472                         (unsigned char)(cur->mask >> 24),
1473                         (unsigned char)(cur->mask >> 16),
1474                         (unsigned char)(cur->mask >> 8),
1475                         (unsigned char)(cur->mask)
1476                 );
1477 #endif
1478                 if ((rmt_ip & cur->mask) == cur->ip)
1479                         return cur->allow_deny == 'A';   /* Allow/Deny */
1480         }
1481
1482         /* if unconfigured, return 1 - access from all */
1483         return !flg_deny_all;
1484 }
1485
1486 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
1487 /*
1488  * Check the permission file for access password protected.
1489  *
1490  * If config file isn't present, everything is allowed.
1491  * Entries are of the form you can see example from header source
1492  *
1493  * path      The file path.
1494  * request   User information to validate.
1495  *
1496  * Returns 1 if request is OK.
1497  */
1498 static int checkPerm(const char *path, const char *request)
1499 {
1500         Htaccess *cur;
1501         const char *p;
1502         const char *p0;
1503
1504         const char *prev = NULL;
1505
1506         /* This could stand some work */
1507         for (cur = g_auth; cur; cur = cur->next) {
1508                 size_t l;
1509
1510                 p0 = cur->before_colon;
1511                 if (prev != NULL && strcmp(prev, p0) != 0)
1512                         continue;       /* find next identical */
1513                 p = cur->after_colon;
1514                 if (DEBUG)
1515                         fprintf(stderr, "checkPerm: '%s' ? '%s'\n", p0, request);
1516
1517                 l = strlen(p0);
1518                 if (strncmp(p0, path, l) == 0
1519                  && (l == 1 || path[l] == '/' || path[l] == '\0')
1520                 ) {
1521                         char *u;
1522                         /* path match found.  Check request */
1523                         /* for check next /path:user:password */
1524                         prev = p0;
1525                         u = strchr(request, ':');
1526                         if (u == NULL) {
1527                                 /* bad request, ':' required */
1528                                 break;
1529                         }
1530
1531                         if (ENABLE_FEATURE_HTTPD_AUTH_MD5) {
1532                                 char *cipher;
1533                                 char *pp;
1534
1535                                 if (strncmp(p, request, u - request) != 0) {
1536                                         /* user doesn't match */
1537                                         continue;
1538                                 }
1539                                 pp = strchr(p, ':');
1540                                 if (pp && pp[1] == '$' && pp[2] == '1'
1541                                  && pp[3] == '$' && pp[4]
1542                                 ) {
1543                                         pp++;
1544                                         cipher = pw_encrypt(u+1, pp);
1545                                         if (strcmp(cipher, pp) == 0)
1546                                                 goto set_remoteuser_var;   /* Ok */
1547                                         /* unauthorized */
1548                                         continue;
1549                                 }
1550                         }
1551
1552                         if (strcmp(p, request) == 0) {
1553  set_remoteuser_var:
1554                                 remoteuser = strdup(request);
1555                                 if (remoteuser)
1556                                         remoteuser[u - request] = '\0';
1557                                 return 1;   /* Ok */
1558                         }
1559                         /* unauthorized */
1560                 }
1561         } /* for */
1562
1563         return prev == NULL;
1564 }
1565 #endif  /* FEATURE_HTTPD_BASIC_AUTH */
1566
1567 /*
1568  * Handle timeouts
1569  */
1570 static void exit_on_signal(int sig) ATTRIBUTE_NORETURN;
1571 static void exit_on_signal(int sig)
1572 {
1573         send_headers_and_exit(HTTP_REQUEST_TIMEOUT);
1574 }
1575
1576 /*
1577  * Handle an incoming http request and exit.
1578  */
1579 static void handle_incoming_and_exit(const len_and_sockaddr *fromAddr) ATTRIBUTE_NORETURN;
1580 static void handle_incoming_and_exit(const len_and_sockaddr *fromAddr)
1581 {
1582         static const char request_GET[] ALIGN1 = "GET";
1583
1584         struct stat sb;
1585         char *urlcopy;
1586         char *urlp;
1587         char *tptr;
1588         int http_major_version;
1589         int ip_allowed;
1590 #if ENABLE_FEATURE_HTTPD_CGI
1591         const char *prequest;
1592         unsigned long length = 0;
1593         char *cookie = 0;
1594         char *content_type = 0;
1595 #endif
1596         struct sigaction sa;
1597 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
1598         int credentials = -1;  /* if not required this is Ok */
1599 #endif
1600
1601         /* Allocation of iobuf is postponed until now
1602          * (IOW, server process doesn't need to waste 8k) */
1603         iobuf = xmalloc(IOBUF_SIZE);
1604
1605         rmt_ip = 0;
1606         if (fromAddr->sa.sa_family == AF_INET) {
1607                 rmt_ip = ntohl(fromAddr->sin.sin_addr.s_addr);
1608         }
1609         if (ENABLE_FEATURE_HTTPD_CGI || DEBUG || verbose) {
1610                 rmt_ip_str = xmalloc_sockaddr2dotted(&fromAddr->sa);
1611         }
1612         if (verbose) {
1613                 /* this trick makes -v logging much simpler */
1614                 applet_name = rmt_ip_str;
1615                 if (verbose > 2)
1616                         bb_error_msg("connected");
1617         }
1618
1619         /* Install timeout handler */
1620         memset(&sa, 0, sizeof(sa));
1621         sa.sa_handler = exit_on_signal;
1622         /* sigemptyset(&sa.sa_mask); - memset should be enough */
1623         /*sa.sa_flags = 0; - no SA_RESTART */
1624         sigaction(SIGALRM, &sa, NULL);
1625         alarm(HEADER_READ_TIMEOUT);
1626
1627         if (!get_line()) /* EOF or error or empty line */
1628                 send_headers_and_exit(HTTP_BAD_REQUEST);
1629
1630         /* Determine type of request (GET/POST) */
1631         urlp = strpbrk(iobuf, " \t");
1632         if (urlp == NULL)
1633                 send_headers_and_exit(HTTP_BAD_REQUEST);
1634         *urlp++ = '\0';
1635 #if ENABLE_FEATURE_HTTPD_CGI
1636         prequest = request_GET;
1637         if (strcasecmp(iobuf, prequest) != 0) {
1638                 prequest = "POST";
1639                 if (strcasecmp(iobuf, prequest) != 0)
1640                         send_headers_and_exit(HTTP_NOT_IMPLEMENTED);
1641         }
1642 #else
1643         if (strcasecmp(iobuf, request_GET) != 0)
1644                 send_headers_and_exit(HTTP_NOT_IMPLEMENTED);
1645 #endif
1646         urlp = skip_whitespace(urlp);
1647         if (urlp[0] != '/')
1648                 send_headers_and_exit(HTTP_BAD_REQUEST);
1649
1650         /* Find end of URL and parse HTTP version, if any */
1651         http_major_version = -1;
1652         tptr = strchrnul(urlp, ' ');
1653         /* Is it " HTTP/"? */
1654         if (tptr[0] && strncmp(tptr + 1, HTTP_200, 5) == 0)
1655                 http_major_version = (tptr[6] - '0');
1656         *tptr = '\0';
1657
1658         /* Copy URL from after "GET "/"POST " to stack-allocated char[] */
1659         urlcopy = alloca((tptr - urlp) + sizeof("/index.html"));
1660         /*if (urlcopy == NULL)
1661          *      send_headers_and_exit(HTTP_INTERNAL_SERVER_ERROR);*/
1662         strcpy(urlcopy, urlp);
1663         /* NB: urlcopy ptr is never changed after this */
1664
1665         /* Extract url args if present */
1666         tptr = strchr(urlcopy, '?');
1667         g_query = NULL;
1668         if (tptr) {
1669                 *tptr++ = '\0';
1670                 g_query = tptr;
1671         }
1672
1673         /* Decode URL escape sequences */
1674         tptr = decodeString(urlcopy, 0);
1675         if (tptr == NULL)
1676                 send_headers_and_exit(HTTP_BAD_REQUEST);
1677         if (tptr == urlcopy + 1) {
1678                 /* '/' or NUL is encoded */
1679                 send_headers_and_exit(HTTP_NOT_FOUND);
1680         }
1681
1682         /* Canonicalize path */
1683         /* Algorithm stolen from libbb bb_simplify_path(),
1684          * but don't strdup and reducing trailing slash and protect out root */
1685         urlp = tptr = urlcopy;
1686         do {
1687                 if (*urlp == '/') {
1688                         /* skip duplicate (or initial) slash */
1689                         if (*tptr == '/') {
1690                                 continue;
1691                         }
1692                         if (*tptr == '.') {
1693                                 /* skip extra '.' */
1694                                 if (tptr[1] == '/' || !tptr[1]) {
1695                                         continue;
1696                                 }
1697                                 /* '..': be careful */
1698                                 if (tptr[1] == '.' && (tptr[2] == '/' || !tptr[2])) {
1699                                         ++tptr;
1700                                         if (urlp == urlcopy) /* protect root */
1701                                                 send_headers_and_exit(HTTP_BAD_REQUEST);
1702                                         while (*--urlp != '/') /* omit previous dir */;
1703                                                 continue;
1704                                 }
1705                         }
1706                 }
1707                 *++urlp = *tptr;
1708         } while (*++tptr);
1709         *++urlp = '\0';       /* so keep last character */
1710         tptr = urlp;          /* end ptr */
1711
1712         /* If URL is a directory, add '/' */
1713         if (tptr[-1] != '/') {
1714                 if (is_directory(urlcopy + 1, 1, &sb)) {
1715                         found_moved_temporarily = urlcopy;
1716                 }
1717         }
1718
1719         /* Log it */
1720         if (verbose > 1)
1721                 bb_error_msg("url:%s", urlcopy);
1722
1723         tptr = urlcopy;
1724         ip_allowed = checkPermIP();
1725         while (ip_allowed && (tptr = strchr(tptr + 1, '/')) != NULL) {
1726                 /* have path1/path2 */
1727                 *tptr = '\0';
1728                 if (is_directory(urlcopy + 1, 1, &sb)) {
1729                         /* may be having subdir config */
1730                         parse_conf(urlcopy + 1, SUBDIR_PARSE);
1731                         ip_allowed = checkPermIP();
1732                 }
1733                 *tptr = '/';
1734         }
1735         if (http_major_version >= 0) {
1736                 /* Request was with "... HTTP/nXXX", and n >= 0 */
1737
1738                 /* Read until blank line for HTTP version specified, else parse immediate */
1739                 while (1) {
1740                         alarm(HEADER_READ_TIMEOUT);
1741                         if (!get_line())
1742                                 break; /* EOF or error or empty line */
1743                         if (DEBUG)
1744                                 bb_error_msg("header: '%s'", iobuf);
1745
1746 #if ENABLE_FEATURE_HTTPD_CGI
1747                         /* try and do our best to parse more lines */
1748                         if ((STRNCASECMP(iobuf, "Content-length:") == 0)) {
1749                                 /* extra read only for POST */
1750                                 if (prequest != request_GET) {
1751                                         tptr = iobuf + sizeof("Content-length:") - 1;
1752                                         if (!tptr[0])
1753                                                 send_headers_and_exit(HTTP_BAD_REQUEST);
1754                                         errno = 0;
1755                                         /* not using strtoul: it ignores leading minus! */
1756                                         length = strtol(tptr, &tptr, 10);
1757                                         /* length is "ulong", but we need to pass it to int later */
1758                                         /* so we check for negative or too large values in one go: */
1759                                         /* (long -> ulong conv caused negatives to be seen as > INT_MAX) */
1760                                         if (tptr[0] || errno || length > INT_MAX)
1761                                                 send_headers_and_exit(HTTP_BAD_REQUEST);
1762                                 }
1763                         } else if (STRNCASECMP(iobuf, "Cookie:") == 0) {
1764                                 cookie = strdup(skip_whitespace(iobuf + sizeof("Cookie:")-1));
1765                         } else if (STRNCASECMP(iobuf, "Content-Type:") == 0) {
1766                                 content_type = strdup(skip_whitespace(iobuf + sizeof("Content-Type:")-1));
1767                         } else if (STRNCASECMP(iobuf, "Referer:") == 0) {
1768                                 referer = strdup(skip_whitespace(iobuf + sizeof("Referer:")-1));
1769                         } else if (STRNCASECMP(iobuf, "User-Agent:") == 0) {
1770                                 user_agent = strdup(skip_whitespace(iobuf + sizeof("User-Agent:")-1));
1771                         }
1772 #endif
1773 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
1774                         if (STRNCASECMP(iobuf, "Authorization:") == 0) {
1775                                 /* We only allow Basic credentials.
1776                                  * It shows up as "Authorization: Basic <userid:password>" where
1777                                  * the userid:password is base64 encoded.
1778                                  */
1779                                 tptr = skip_whitespace(iobuf + sizeof("Authorization:")-1);
1780                                 if (STRNCASECMP(tptr, "Basic") != 0)
1781                                         continue;
1782                                 tptr += sizeof("Basic")-1;
1783                                 /* decodeBase64() skips whitespace itself */
1784                                 decodeBase64(tptr);
1785                                 credentials = checkPerm(urlcopy, tptr);
1786                         }
1787 #endif          /* FEATURE_HTTPD_BASIC_AUTH */
1788                 } /* while extra header reading */
1789         }
1790
1791         /* We read headers, disable peer timeout */
1792         alarm(0);
1793
1794         if (strcmp(bb_basename(urlcopy), httpd_conf) == 0 || ip_allowed == 0) {
1795                 /* protect listing [/path]/httpd_conf or IP deny */
1796                 send_headers_and_exit(HTTP_FORBIDDEN);
1797         }
1798
1799 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
1800         if (credentials <= 0 && checkPerm(urlcopy, ":") == 0) {
1801                 send_headers_and_exit(HTTP_UNAUTHORIZED);
1802         }
1803 #endif
1804
1805         if (found_moved_temporarily) {
1806                 send_headers_and_exit(HTTP_MOVED_TEMPORARILY);
1807         }
1808
1809         tptr = urlcopy + 1;      /* skip first '/' */
1810
1811 #if ENABLE_FEATURE_HTTPD_CGI
1812         if (strncmp(tptr, "cgi-bin/", 8) == 0) {
1813                 if (tptr[8] == '\0') {
1814                         /* protect listing "cgi-bin/" */
1815                         send_headers_and_exit(HTTP_FORBIDDEN);
1816                 }
1817                 send_cgi_and_exit(urlcopy, prequest, length, cookie, content_type);
1818         }
1819 #if ENABLE_FEATURE_HTTPD_CONFIG_WITH_SCRIPT_INTERPR
1820         {
1821                 char *suffix = strrchr(tptr, '.');
1822                 if (suffix) {
1823                         Htaccess *cur;
1824                         for (cur = script_i; cur; cur = cur->next) {
1825                                 if (strcmp(cur->before_colon + 1, suffix) == 0) {
1826                                         send_cgi_and_exit(urlcopy, prequest, length, cookie, content_type);
1827                                 }
1828                         }
1829                 }
1830         }
1831 #endif
1832         if (prequest != request_GET) {
1833                 send_headers_and_exit(HTTP_NOT_IMPLEMENTED);
1834         }
1835 #endif  /* FEATURE_HTTPD_CGI */
1836
1837         if (urlp[-1] == '/')
1838                 strcpy(urlp, "index.html");
1839         if (stat(tptr, &sb) == 0) {
1840                 /* It's a dir URL and there is index.html */
1841                 ContentLength = sb.st_size;
1842                 last_mod = sb.st_mtime;
1843         }
1844 #if ENABLE_FEATURE_HTTPD_CGI
1845         else if (urlp[-1] == '/') {
1846                 /* It's a dir URL and there is no index.html
1847                  * Try cgi-bin/index.cgi */
1848                 if (access("/cgi-bin/index.cgi"+1, X_OK) == 0) {
1849                         urlp[0] = '\0';
1850                         g_query = urlcopy;
1851                         send_cgi_and_exit("/cgi-bin/index.cgi", prequest, length, cookie, content_type);
1852                 }
1853         }
1854 #endif
1855         /* else {
1856          *      fall through to send_file, it errors out if open fails
1857          * }
1858          */
1859
1860         send_file_and_exit(tptr, TRUE);
1861 }
1862
1863 /*
1864  * The main http server function.
1865  * Given a socket, listen for new connections and farm out
1866  * the processing as a [v]forked process.
1867  * Never returns.
1868  */
1869 #if BB_MMU
1870 static void mini_httpd(int server_socket) ATTRIBUTE_NORETURN;
1871 static void mini_httpd(int server_socket)
1872 {
1873         /* NB: it's best to not use xfuncs in this loop before fork().
1874          * Otherwise server may die on transient errors (temporary
1875          * out-of-memory condition, etc), which is Bad(tm).
1876          * Try to do any dangerous calls after fork.
1877          */
1878         while (1) {
1879                 int n;
1880                 len_and_sockaddr fromAddr;
1881
1882                 /* Wait for connections... */
1883                 fromAddr.len = LSA_SIZEOF_SA;
1884                 n = accept(server_socket, &fromAddr.sa, &fromAddr.len);
1885
1886                 if (n < 0)
1887                         continue;
1888                 /* set the KEEPALIVE option to cull dead connections */
1889                 setsockopt(n, SOL_SOCKET, SO_KEEPALIVE, &const_int_1, sizeof(const_int_1));
1890
1891                 if (fork() == 0) {
1892                         /* child */
1893 #if ENABLE_FEATURE_HTTPD_RELOAD_CONFIG_SIGHUP
1894                         /* Do not reload config on HUP */
1895                         signal(SIGHUP, SIG_IGN);
1896 #endif
1897                         close(server_socket);
1898                         xmove_fd(n, 0);
1899                         xdup2(0, 1);
1900
1901                         handle_incoming_and_exit(&fromAddr);
1902                 }
1903                 /* parent, or fork failed */
1904                 close(n);
1905         } /* while (1) */
1906         /* never reached */
1907 }
1908 #else
1909 static void mini_httpd_nommu(int server_socket, int argc, char **argv) ATTRIBUTE_NORETURN;
1910 static void mini_httpd_nommu(int server_socket, int argc, char **argv)
1911 {
1912         char *argv_copy[argc + 2];
1913
1914         argv_copy[0] = argv[0];
1915         argv_copy[1] = (char*)"-i";
1916         memcpy(&argv_copy[2], &argv[1], argc * sizeof(argv[0]));
1917
1918         /* NB: it's best to not use xfuncs in this loop before vfork().
1919          * Otherwise server may die on transient errors (temporary
1920          * out-of-memory condition, etc), which is Bad(tm).
1921          * Try to do any dangerous calls after fork.
1922          */
1923         while (1) {
1924                 int n;
1925                 len_and_sockaddr fromAddr;
1926
1927                 /* Wait for connections... */
1928                 fromAddr.len = LSA_SIZEOF_SA;
1929                 n = accept(server_socket, &fromAddr.sa, &fromAddr.len);
1930
1931                 if (n < 0)
1932                         continue;
1933                 /* set the KEEPALIVE option to cull dead connections */
1934                 setsockopt(n, SOL_SOCKET, SO_KEEPALIVE, &const_int_1, sizeof(const_int_1));
1935
1936                 if (vfork() == 0) {
1937                         /* child */
1938 #if ENABLE_FEATURE_HTTPD_RELOAD_CONFIG_SIGHUP
1939                         /* Do not reload config on HUP */
1940                         signal(SIGHUP, SIG_IGN);
1941 #endif
1942                         close(server_socket);
1943                         xmove_fd(n, 0);
1944                         xdup2(0, 1);
1945
1946                         /* Run a copy of ourself in inetd mode */
1947                         re_exec(argv_copy);
1948                 }
1949                 /* parent, or vfork failed */
1950                 close(n);
1951         } /* while (1) */
1952         /* never reached */
1953 }
1954 #endif
1955
1956 /*
1957  * Process a HTTP connection on stdin/out.
1958  * Never returns.
1959  */
1960 static void mini_httpd_inetd(void) ATTRIBUTE_NORETURN;
1961 static void mini_httpd_inetd(void)
1962 {
1963         len_and_sockaddr fromAddr;
1964
1965         fromAddr.len = LSA_SIZEOF_SA;
1966         getpeername(0, &fromAddr.sa, &fromAddr.len);
1967         handle_incoming_and_exit(&fromAddr);
1968 }
1969
1970 #if ENABLE_FEATURE_HTTPD_RELOAD_CONFIG_SIGHUP
1971 static void sighup_handler(int sig)
1972 {
1973         struct sigaction sa;
1974
1975         parse_conf(default_path_httpd_conf, sig == SIGHUP ? SIGNALED_PARSE : FIRST_PARSE);
1976
1977         memset(&sa, 0, sizeof(sa));
1978         sa.sa_handler = sighup_handler;
1979         /*sigemptyset(&sa.sa_mask); - memset should be enough */
1980         sa.sa_flags = SA_RESTART;
1981         sigaction(SIGHUP, &sa, NULL);
1982 }
1983 #endif
1984
1985 enum {
1986         c_opt_config_file = 0,
1987         d_opt_decode_url,
1988         h_opt_home_httpd,
1989         USE_FEATURE_HTTPD_ENCODE_URL_STR(e_opt_encode_url,)
1990         USE_FEATURE_HTTPD_BASIC_AUTH(    r_opt_realm     ,)
1991         USE_FEATURE_HTTPD_AUTH_MD5(      m_opt_md5       ,)
1992         USE_FEATURE_HTTPD_SETUID(        u_opt_setuid    ,)
1993         p_opt_port      ,
1994         p_opt_inetd     ,
1995         p_opt_foreground,
1996         p_opt_verbose   ,
1997         OPT_CONFIG_FILE = 1 << c_opt_config_file,
1998         OPT_DECODE_URL  = 1 << d_opt_decode_url,
1999         OPT_HOME_HTTPD  = 1 << h_opt_home_httpd,
2000         OPT_ENCODE_URL  = USE_FEATURE_HTTPD_ENCODE_URL_STR((1 << e_opt_encode_url)) + 0,
2001         OPT_REALM       = USE_FEATURE_HTTPD_BASIC_AUTH(    (1 << r_opt_realm     )) + 0,
2002         OPT_MD5         = USE_FEATURE_HTTPD_AUTH_MD5(      (1 << m_opt_md5       )) + 0,
2003         OPT_SETUID      = USE_FEATURE_HTTPD_SETUID(        (1 << u_opt_setuid    )) + 0,
2004         OPT_PORT        = 1 << p_opt_port,
2005         OPT_INETD       = 1 << p_opt_inetd,
2006         OPT_FOREGROUND  = 1 << p_opt_foreground,
2007         OPT_VERBOSE     = 1 << p_opt_verbose,
2008 };
2009
2010
2011 int httpd_main(int argc, char **argv);
2012 int httpd_main(int argc, char **argv)
2013 {
2014         int server_socket = server_socket; /* for gcc */
2015         unsigned opt;
2016         char *url_for_decode;
2017         USE_FEATURE_HTTPD_ENCODE_URL_STR(const char *url_for_encode;)
2018         USE_FEATURE_HTTPD_SETUID(const char *s_ugid = NULL;)
2019         USE_FEATURE_HTTPD_SETUID(struct bb_uidgid_t ugid;)
2020         USE_FEATURE_HTTPD_AUTH_MD5(const char *pass;)
2021
2022         INIT_G();
2023
2024 #if ENABLE_LOCALE_SUPPORT
2025         /* Undo busybox.c: we want to speak English in http (dates etc) */
2026         setlocale(LC_TIME, "C");
2027 #endif
2028
2029         home_httpd = xrealloc_getcwd_or_warn(NULL);
2030         /* -v counts, -i implies -f */
2031         opt_complementary = "vv:if";
2032         /* We do not "absolutize" path given by -h (home) opt.
2033          * If user gives relative path in -h, $SCRIPT_FILENAME can end up
2034          * relative too. */
2035         opt = getopt32(argv, "c:d:h:"
2036                         USE_FEATURE_HTTPD_ENCODE_URL_STR("e:")
2037                         USE_FEATURE_HTTPD_BASIC_AUTH("r:")
2038                         USE_FEATURE_HTTPD_AUTH_MD5("m:")
2039                         USE_FEATURE_HTTPD_SETUID("u:")
2040                         "p:ifv",
2041                         &configFile, &url_for_decode, &home_httpd
2042                         USE_FEATURE_HTTPD_ENCODE_URL_STR(, &url_for_encode)
2043                         USE_FEATURE_HTTPD_BASIC_AUTH(, &g_realm)
2044                         USE_FEATURE_HTTPD_AUTH_MD5(, &pass)
2045                         USE_FEATURE_HTTPD_SETUID(, &s_ugid)
2046                         , &bind_addr_or_port
2047                         , &verbose
2048                 );
2049         if (opt & OPT_DECODE_URL) {
2050                 fputs(decodeString(url_for_decode, 1), stdout);
2051                 return 0;
2052         }
2053 #if ENABLE_FEATURE_HTTPD_ENCODE_URL_STR
2054         if (opt & OPT_ENCODE_URL) {
2055                 fputs(encodeString(url_for_encode), stdout);
2056                 return 0;
2057         }
2058 #endif
2059 #if ENABLE_FEATURE_HTTPD_AUTH_MD5
2060         if (opt & OPT_MD5) {
2061                 puts(pw_encrypt(pass, "$1$"));
2062                 return 0;
2063         }
2064 #endif
2065 #if ENABLE_FEATURE_HTTPD_SETUID
2066         if (opt & OPT_SETUID) {
2067                 if (!get_uidgid(&ugid, s_ugid, 1))
2068                         bb_error_msg_and_die("unrecognized user[:group] "
2069                                                 "name '%s'", s_ugid);
2070         }
2071 #endif
2072
2073 #if !BB_MMU
2074         if (!(opt & OPT_FOREGROUND)) {
2075                 bb_daemonize_or_rexec(0, argv); /* don't change current directory */
2076         }
2077 #endif
2078
2079         xchdir(home_httpd);
2080         if (!(opt & OPT_INETD)) {
2081                 signal(SIGCHLD, SIG_IGN);
2082                 server_socket = openServer();
2083 #if ENABLE_FEATURE_HTTPD_SETUID
2084                 /* drop privileges */
2085                 if (opt & OPT_SETUID) {
2086                         if (ugid.gid != (gid_t)-1) {
2087                                 if (setgroups(1, &ugid.gid) == -1)
2088                                         bb_perror_msg_and_die("setgroups");
2089                                 xsetgid(ugid.gid);
2090                         }
2091                         xsetuid(ugid.uid);
2092                 }
2093 #endif
2094         }
2095
2096 #if ENABLE_FEATURE_HTTPD_CGI
2097         {
2098                 char *p = getenv("PATH");
2099                 /* env strings themself are not freed, no need to strdup(p): */
2100                 clearenv();
2101                 if (p)
2102                         putenv(p - 5);
2103 //              if (!(opt & OPT_INETD))
2104 //                      setenv_long("SERVER_PORT", ???);
2105         }
2106 #endif
2107
2108 #if ENABLE_FEATURE_HTTPD_RELOAD_CONFIG_SIGHUP
2109         if (!(opt & OPT_INETD))
2110                 sighup_handler(0);
2111         else /* do not install HUP handler in inetd mode */
2112 #endif
2113                 parse_conf(default_path_httpd_conf, FIRST_PARSE);
2114
2115         xfunc_error_retval = 0;
2116         if (opt & OPT_INETD)
2117                 mini_httpd_inetd();
2118 #if BB_MMU
2119         if (!(opt & OPT_FOREGROUND))
2120                 bb_daemonize(0); /* don't change current directory */
2121         mini_httpd(server_socket); /* never returns */
2122 #else
2123         mini_httpd_nommu(server_socket, argc, argv); /* never returns */
2124 #endif
2125         /* return 0; */
2126 }