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  * Licensed under GPLv2 or later, see file LICENSE in this source tree.
   9  *
  10  *****************************************************************************
  11  *
  12  * Typical usage:
  13  * For non root user:
  14  *      httpd -p 8080 -h $HOME/public_html
  15  * For daemon start from rc script with uid=0:
  16  *      httpd -u www
  17  * which is equivalent to (assuming user www has uid 80):
  18  *      httpd -p 80 -u 80 -h $PWD -c /etc/httpd.conf -r "Web Server Authentication"
  19  *
  20  * When an url starts with "/cgi-bin/" it is assumed to be a cgi script.
  21  * The server changes directory to the location of the script and executes it
  22  * after setting QUERY_STRING and other environment variables.
  23  *
  24  * If directory URL is given, no index.html is found and CGI support is enabled,
  25  * cgi-bin/index.cgi will be run. Directory to list is ../$QUERY_STRING.
  26  * See httpd_indexcgi.c for an example GCI code.
  27  *
  28  * Doc:
  29  * "CGI Environment Variables": http://hoohoo.ncsa.uiuc.edu/cgi/env.html
  30  *
  31  * The applet can also be invoked as an url arg decoder and html text encoder
  32  * as follows:
  33  *      foo=`httpd -d $foo`             # decode "Hello%20World" as "Hello World"
  34  *      bar=`httpd -e "<Hello World>"`  # encode as "&#60Hello&#32World&#62"
  35  * Note that url encoding for arguments is not the same as html encoding for
  36  * presentation.  -d decodes an url-encoded argument while -e encodes in html
  37  * for page display.
  38  *
  39  * httpd.conf has the following format:
  40  *
  41  * H:/serverroot     # define the server root. It will override -h
  42  * A:172.20.         # Allow address from 172.20.0.0/16
  43  * A:10.0.0.0/25     # Allow any address from 10.0.0.0-10.0.0.127
  44  * A:10.0.0.0/255.255.255.128  # Allow any address that previous set
  45  * A:127.0.0.1       # Allow local loopback connections
  46  * D:*               # Deny from other IP connections
  47  * E404:/path/e404.html # /path/e404.html is the 404 (not found) error page
  48  * I:index.html      # Show index.html when a directory is requested
  49  *
  50  * P:/url:[http://]hostname[:port]/new/path
  51  *                   # When /urlXXXXXX is requested, reverse proxy
  52  *                   # it to http://hostname[:port]/new/pathXXXXXX
  53  *
  54  * /cgi-bin:foo:bar  # Require user foo, pwd bar on urls starting with /cgi-bin/
  55  * /adm:admin:setup  # Require user admin, pwd setup on urls starting with /adm/
  56  * /adm:toor:PaSsWd  # or user toor, pwd PaSsWd on urls starting with /adm/
  57  * .au:audio/basic   # additional mime type for audio.au files
  58  * *.php:/path/php   # run xxx.php through an interpreter
  59  *
  60  * A/D may be as a/d or allow/deny - only first char matters.
  61  * Deny/Allow IP logic:
  62  *  - Default is to allow all (Allow all (A:*) is a no-op).
  63  *  - Deny rules take precedence over allow rules.
  64  *  - "Deny all" rule (D:*) is applied last.
  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 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  /* TODO: use TCP_CORK, parse_config() */
  99
 100 //usage:#define httpd_trivial_usage
 101 //usage:       "[-ifv[v]]"
 102 //usage:       " [-c CONFFILE]"
 103 //usage:       " [-p [IP:]PORT]"
 104 //usage:        IF_FEATURE_HTTPD_SETUID(" [-u USER[:GRP]]")
 105 //usage:        IF_FEATURE_HTTPD_BASIC_AUTH(" [-r REALM]")
 106 //usage:       " [-h HOME]\n"
 107 //usage:       "or httpd -d/-e" IF_FEATURE_HTTPD_AUTH_MD5("/-m") " STRING"
 108 //usage:#define httpd_full_usage "\n\n"
 109 //usage:       "Listen for incoming HTTP requests\n"
 110 //usage:     "\nOptions:"
 111 //usage:     "\n        -i              Inetd mode"
 112 //usage:     "\n        -f              Don't daemonize"
 113 //usage:     "\n        -v[v]           Verbose"
 114 //usage:     "\n        -p [IP:]PORT    Bind to IP:PORT (default *:80)"
 115 //usage:        IF_FEATURE_HTTPD_SETUID(
 116 //usage:     "\n        -u USER[:GRP]   Set uid/gid after binding to port")
 117 //usage:        IF_FEATURE_HTTPD_BASIC_AUTH(
 118 //usage:     "\n        -r REALM        Authentication Realm for Basic Authentication")
 119 //usage:     "\n        -h HOME         Home directory (default .)"
 120 //usage:     "\n        -c FILE         Configuration file (default {/etc,HOME}/httpd.conf)"
 121 //usage:        IF_FEATURE_HTTPD_AUTH_MD5(
 122 //usage:     "\n        -m STRING       MD5 crypt STRING")
 123 //usage:     "\n        -e STRING       HTML encode STRING"
 124 //usage:     "\n        -d STRING       URL decode STRING"
 125
 126 #include "libbb.h"
 127 #if ENABLE_FEATURE_HTTPD_USE_SENDFILE
 128 # include <sys/sendfile.h>
 129 #endif
 130 /* amount of buffering in a pipe */
 131 #ifndef PIPE_BUF
 132 # define PIPE_BUF 4096
 133 #endif
 134
 135 #define DEBUG 0
 136
 137 #define IOBUF_SIZE 8192
 138 #if PIPE_BUF >= IOBUF_SIZE
 139 # error "PIPE_BUF >= IOBUF_SIZE"
 140 #endif
 141
 142 #define HEADER_READ_TIMEOUT 60
 143
 144 static const char DEFAULT_PATH_HTTPD_CONF[] ALIGN1 = "/etc";
 145 static const char HTTPD_CONF[] ALIGN1 = "httpd.conf";
 146 static const char HTTP_200[] ALIGN1 = "HTTP/1.0 200 OK\r\n";
 147 static const char index_html[] ALIGN1 = "index.html";
 148
 149 typedef struct has_next_ptr {
 150         struct has_next_ptr *next;
 151 } has_next_ptr;
 152
 153 /* Must have "next" as a first member */
 154 typedef struct Htaccess {
 155         struct Htaccess *next;
 156         char *after_colon;
 157         char before_colon[1];  /* really bigger, must be last */
 158 } Htaccess;
 159
 160 /* Must have "next" as a first member */
 161 typedef struct Htaccess_IP {
 162         struct Htaccess_IP *next;
 163         unsigned ip;
 164         unsigned mask;
 165         int allow_deny;
 166 } Htaccess_IP;
 167
 168 /* Must have "next" as a first member */
 169 typedef struct Htaccess_Proxy {
 170         struct Htaccess_Proxy *next;
 171         char *url_from;
 172         char *host_port;
 173         char *url_to;
 174 } Htaccess_Proxy;
 175
 176 enum {
 177         HTTP_OK = 200,
 178         HTTP_PARTIAL_CONTENT = 206,
 179         HTTP_MOVED_TEMPORARILY = 302,
 180         HTTP_BAD_REQUEST = 400,       /* malformed syntax */
 181         HTTP_UNAUTHORIZED = 401, /* authentication needed, respond with auth hdr */
 182         HTTP_NOT_FOUND = 404,
 183         HTTP_FORBIDDEN = 403,
 184         HTTP_REQUEST_TIMEOUT = 408,
 185         HTTP_NOT_IMPLEMENTED = 501,   /* used for unrecognized requests */
 186         HTTP_INTERNAL_SERVER_ERROR = 500,
 187         HTTP_CONTINUE = 100,
 188 #if 0   /* future use */
 189         HTTP_SWITCHING_PROTOCOLS = 101,
 190         HTTP_CREATED = 201,
 191         HTTP_ACCEPTED = 202,
 192         HTTP_NON_AUTHORITATIVE_INFO = 203,
 193         HTTP_NO_CONTENT = 204,
 194         HTTP_MULTIPLE_CHOICES = 300,
 195         HTTP_MOVED_PERMANENTLY = 301,
 196         HTTP_NOT_MODIFIED = 304,
 197         HTTP_PAYMENT_REQUIRED = 402,
 198         HTTP_BAD_GATEWAY = 502,
 199         HTTP_SERVICE_UNAVAILABLE = 503, /* overload, maintenance */
 200 #endif
 201 };
 202
 203 static const uint16_t http_response_type[] ALIGN2 = {
 204         HTTP_OK,
 205 #if ENABLE_FEATURE_HTTPD_RANGES
 206         HTTP_PARTIAL_CONTENT,
 207 #endif
 208         HTTP_MOVED_TEMPORARILY,
 209         HTTP_REQUEST_TIMEOUT,
 210         HTTP_NOT_IMPLEMENTED,
 211 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
 212         HTTP_UNAUTHORIZED,
 213 #endif
 214         HTTP_NOT_FOUND,
 215         HTTP_BAD_REQUEST,
 216         HTTP_FORBIDDEN,
 217         HTTP_INTERNAL_SERVER_ERROR,
 218 #if 0   /* not implemented */
 219         HTTP_CREATED,
 220         HTTP_ACCEPTED,
 221         HTTP_NO_CONTENT,
 222         HTTP_MULTIPLE_CHOICES,
 223         HTTP_MOVED_PERMANENTLY,
 224         HTTP_NOT_MODIFIED,
 225         HTTP_BAD_GATEWAY,
 226         HTTP_SERVICE_UNAVAILABLE,
 227 #endif
 228 };
 229
 230 static const struct {
 231         const char *name;
 232         const char *info;
 233 } http_response[ARRAY_SIZE(http_response_type)] = {
 234         { "OK", NULL },
 235 #if ENABLE_FEATURE_HTTPD_RANGES
 236         { "Partial Content", NULL },
 237 #endif
 238         { "Found", NULL },
 239         { "Request Timeout", "No request appeared within 60 seconds" },
 240         { "Not Implemented", "The requested method is not recognized" },
 241 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
 242         { "Unauthorized", "" },
 243 #endif
 244         { "Not Found", "The requested URL was not found" },
 245         { "Bad Request", "Unsupported method" },
 246         { "Forbidden", ""  },
 247         { "Internal Server Error", "Internal Server Error" },
 248 #if 0   /* not implemented */
 249         { "Created" },
 250         { "Accepted" },
 251         { "No Content" },
 252         { "Multiple Choices" },
 253         { "Moved Permanently" },
 254         { "Not Modified" },
 255         { "Bad Gateway", "" },
 256         { "Service Unavailable", "" },
 257 #endif
 258 };
 259
 260 struct globals {
 261         int verbose;            /* must be int (used by getopt32) */
 262         smallint flg_deny_all;
 263
 264         unsigned rmt_ip;        /* used for IP-based allow/deny rules */
 265         time_t last_mod;
 266         char *rmt_ip_str;       /* for $REMOTE_ADDR and $REMOTE_PORT */
 267         const char *bind_addr_or_port;
 268
 269         const char *g_query;
 270         const char *opt_c_configFile;
 271         const char *home_httpd;
 272         const char *index_page;
 273
 274         const char *found_mime_type;
 275         const char *found_moved_temporarily;
 276         Htaccess_IP *ip_a_d;    /* config allow/deny lines */
 277
 278         IF_FEATURE_HTTPD_BASIC_AUTH(const char *g_realm;)
 279         IF_FEATURE_HTTPD_BASIC_AUTH(char *remoteuser;)
 280         IF_FEATURE_HTTPD_CGI(char *referer;)
 281         IF_FEATURE_HTTPD_CGI(char *user_agent;)
 282         IF_FEATURE_HTTPD_CGI(char *host;)
 283         IF_FEATURE_HTTPD_CGI(char *http_accept;)
 284         IF_FEATURE_HTTPD_CGI(char *http_accept_language;)
 285
 286         off_t file_size;        /* -1 - unknown */
 287 #if ENABLE_FEATURE_HTTPD_RANGES
 288         off_t range_start;
 289         off_t range_end;
 290         off_t range_len;
 291 #endif
 292
 293 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
 294         Htaccess *g_auth;       /* config user:password lines */
 295 #endif
 296         Htaccess *mime_a;       /* config mime types */
 297 #if ENABLE_FEATURE_HTTPD_CONFIG_WITH_SCRIPT_INTERPR
 298         Htaccess *script_i;     /* config script interpreters */
 299 #endif
 300         char *iobuf;            /* [IOBUF_SIZE] */
 301 #define hdr_buf bb_common_bufsiz1
 302         char *hdr_ptr;
 303         int hdr_cnt;
 304 #if ENABLE_FEATURE_HTTPD_ERROR_PAGES
 305         const char *http_error_page[ARRAY_SIZE(http_response_type)];
 306 #endif
 307 #if ENABLE_FEATURE_HTTPD_PROXY
 308         Htaccess_Proxy *proxy;
 309 #endif
 310 #if ENABLE_FEATURE_HTTPD_GZIP
 311         /* client can handle gzip / we are going to send gzip */
 312         smallint content_gzip;
 313 #endif
 314 };
 315 #define G (*ptr_to_globals)
 316 #define verbose           (G.verbose          )
 317 #define flg_deny_all      (G.flg_deny_all     )
 318 #define rmt_ip            (G.rmt_ip           )
 319 #define bind_addr_or_port (G.bind_addr_or_port)
 320 #define g_query           (G.g_query          )
 321 #define opt_c_configFile  (G.opt_c_configFile )
 322 #define home_httpd        (G.home_httpd       )
 323 #define index_page        (G.index_page       )
 324 #define found_mime_type   (G.found_mime_type  )
 325 #define found_moved_temporarily (G.found_moved_temporarily)
 326 #define last_mod          (G.last_mod         )
 327 #define ip_a_d            (G.ip_a_d           )
 328 #define g_realm           (G.g_realm          )
 329 #define remoteuser        (G.remoteuser       )
 330 #define referer           (G.referer          )
 331 #define user_agent        (G.user_agent       )
 332 #define host              (G.host             )
 333 #define http_accept       (G.http_accept      )
 334 #define http_accept_language (G.http_accept_language)
 335 #define file_size         (G.file_size        )
 336 #if ENABLE_FEATURE_HTTPD_RANGES
 337 #define range_start       (G.range_start      )
 338 #define range_end         (G.range_end        )
 339 #define range_len         (G.range_len        )
 340 #else
 341 enum {
 342         range_start = 0,
 343         range_end = MAXINT(off_t) - 1,
 344         range_len = MAXINT(off_t),
 345 };
 346 #endif
 347 #define rmt_ip_str        (G.rmt_ip_str       )
 348 #define g_auth            (G.g_auth           )
 349 #define mime_a            (G.mime_a           )
 350 #define script_i          (G.script_i         )
 351 #define iobuf             (G.iobuf            )
 352 #define hdr_ptr           (G.hdr_ptr          )
 353 #define hdr_cnt           (G.hdr_cnt          )
 354 #define http_error_page   (G.http_error_page  )
 355 #define proxy             (G.proxy            )
 356 #if ENABLE_FEATURE_HTTPD_GZIP
 357 # define content_gzip     (G.content_gzip     )
 358 #else
 359 # define content_gzip     0
 360 #endif
 361 #define INIT_G() do { \
 362         SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
 363         IF_FEATURE_HTTPD_BASIC_AUTH(g_realm = "Web Server Authentication";) \
 364         bind_addr_or_port = "80"; \
 365         index_page = index_html; \
 366         file_size = -1; \
 367 } while (0)
 368
 369
 370 #define STRNCASECMP(a, str) strncasecmp((a), (str), sizeof(str)-1)
 371
 372 /* Prototypes */
 373 enum {
 374         SEND_HEADERS     = (1 << 0),
 375         SEND_BODY        = (1 << 1),
 376         SEND_HEADERS_AND_BODY = SEND_HEADERS + SEND_BODY,
 377 };
 378 static void send_file_and_exit(const char *url, int what) NORETURN;
 379
 380 static void free_llist(has_next_ptr **pptr)
 381 {
 382         has_next_ptr *cur = *pptr;
 383         while (cur) {
 384                 has_next_ptr *t = cur;
 385                 cur = cur->next;
 386                 free(t);
 387         }
 388         *pptr = NULL;
 389 }
 390
 391 static ALWAYS_INLINE void free_Htaccess_list(Htaccess **pptr)
 392 {
 393         free_llist((has_next_ptr**)pptr);
 394 }
 395
 396 static ALWAYS_INLINE void free_Htaccess_IP_list(Htaccess_IP **pptr)
 397 {
 398         free_llist((has_next_ptr**)pptr);
 399 }
 400
 401 /* Returns presumed mask width in bits or < 0 on error.
 402  * Updates strp, stores IP at provided pointer */
 403 static int scan_ip(const char **strp, unsigned *ipp, unsigned char endc)
 404 {
 405         const char *p = *strp;
 406         int auto_mask = 8;
 407         unsigned ip = 0;
 408         int j;
 409
 410         if (*p == '/')
 411                 return -auto_mask;
 412
 413         for (j = 0; j < 4; j++) {
 414                 unsigned octet;
 415
 416                 if ((*p < '0' || *p > '9') && *p != '/' && *p)
 417                         return -auto_mask;
 418                 octet = 0;
 419                 while (*p >= '0' && *p <= '9') {
 420                         octet *= 10;
 421                         octet += *p - '0';
 422                         if (octet > 255)
 423                                 return -auto_mask;
 424                         p++;
 425                 }
 426                 if (*p == '.')
 427                         p++;
 428                 if (*p != '/' && *p)
 429                         auto_mask += 8;
 430                 ip = (ip << 8) | octet;
 431         }
 432         if (*p) {
 433                 if (*p != endc)
 434                         return -auto_mask;
 435                 p++;
 436                 if (*p == '\0')
 437                         return -auto_mask;
 438         }
 439         *ipp = ip;
 440         *strp = p;
 441         return auto_mask;
 442 }
 443
 444 /* Returns 0 on success. Stores IP and mask at provided pointers */
 445 static int scan_ip_mask(const char *str, unsigned *ipp, unsigned *maskp)
 446 {
 447         int i;
 448         unsigned mask;
 449         char *p;
 450
 451         i = scan_ip(&str, ipp, '/');
 452         if (i < 0)
 453                 return i;
 454
 455         if (*str) {
 456                 /* there is /xxx after dotted-IP address */
 457                 i = bb_strtou(str, &p, 10);
 458                 if (*p == '.') {
 459                         /* 'xxx' itself is dotted-IP mask, parse it */
 460                         /* (return 0 (success) only if it has N.N.N.N form) */
 461                         return scan_ip(&str, maskp, '\0') - 32;
 462                 }
 463                 if (*p)
 464                         return -1;
 465         }
 466
 467         if (i > 32)
 468                 return -1;
 469
 470         if (sizeof(unsigned) == 4 && i == 32) {
 471                 /* mask >>= 32 below may not work */
 472                 mask = 0;
 473         } else {
 474                 mask = 0xffffffff;
 475                 mask >>= i;
 476         }
 477         /* i == 0 -> *maskp = 0x00000000
 478          * i == 1 -> *maskp = 0x80000000
 479          * i == 4 -> *maskp = 0xf0000000
 480          * i == 31 -> *maskp = 0xfffffffe
 481          * i == 32 -> *maskp = 0xffffffff */
 482         *maskp = (uint32_t)(~mask);
 483         return 0;
 484 }
 485
 486 /*
 487  * Parse configuration file into in-memory linked list.
 488  *
 489  * Any previous IP rules are discarded.
 490  * If the flag argument is not SUBDIR_PARSE then all /path and mime rules
 491  * are also discarded.  That is, previous settings are retained if flag is
 492  * SUBDIR_PARSE.
 493  * Error pages are only parsed on the main config file.
 494  *
 495  * path   Path where to look for httpd.conf (without filename).
 496  * flag   Type of the parse request.
 497  */
 498 /* flag param: */
 499 enum {
 500         FIRST_PARSE    = 0, /* path will be "/etc" */
 501         SIGNALED_PARSE = 1, /* path will be "/etc" */
 502         SUBDIR_PARSE   = 2, /* path will be derived from URL */
 503 };
 504 static void parse_conf(const char *path, int flag)
 505 {
 506         /* internally used extra flag state */
 507         enum { TRY_CURDIR_PARSE = 3 };
 508
 509         FILE *f;
 510         const char *filename;
 511         char buf[160];
 512
 513         /* discard old rules */
 514         free_Htaccess_IP_list(&ip_a_d);
 515         flg_deny_all = 0;
 516         /* retain previous auth and mime config only for subdir parse */
 517         if (flag != SUBDIR_PARSE) {
 518                 free_Htaccess_list(&mime_a);
 519 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
 520                 free_Htaccess_list(&g_auth);
 521 #endif
 522 #if ENABLE_FEATURE_HTTPD_CONFIG_WITH_SCRIPT_INTERPR
 523                 free_Htaccess_list(&script_i);
 524 #endif
 525         }
 526
 527         filename = opt_c_configFile;
 528         if (flag == SUBDIR_PARSE || filename == NULL) {
 529                 filename = alloca(strlen(path) + sizeof(HTTPD_CONF) + 2);
 530                 sprintf((char *)filename, "%s/%s", path, HTTPD_CONF);
 531         }
 532
 533         while ((f = fopen_for_read(filename)) == NULL) {
 534                 if (flag >= SUBDIR_PARSE) { /* SUBDIR or TRY_CURDIR */
 535                         /* config file not found, no changes to config */
 536                         return;
 537                 }
 538                 if (flag == FIRST_PARSE) {
 539                         /* -c CONFFILE given, but CONFFILE doesn't exist? */
 540                         if (opt_c_configFile)
 541                                 bb_simple_perror_msg_and_die(opt_c_configFile);
 542                         /* else: no -c, thus we looked at /etc/httpd.conf,
 543                          * and it's not there. try ./httpd.conf: */
 544                 }
 545                 flag = TRY_CURDIR_PARSE;
 546                 filename = HTTPD_CONF;
 547         }
 548
 549 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
 550         /* in "/file:user:pass" lines, we prepend path in subdirs */
 551         if (flag != SUBDIR_PARSE)
 552                 path = "";
 553 #endif
 554         /* The lines can be:
 555          *
 556          * I:default_index_file
 557          * H:http_home
 558          * [AD]:IP[/mask]   # allow/deny, * for wildcard
 559          * Ennn:error.html  # error page for status nnn
 560          * P:/url:[http://]hostname[:port]/new/path # reverse proxy
 561          * .ext:mime/type   # mime type
 562          * *.php:/path/php  # run xxx.php through an interpreter
 563          * /file:user:pass  # username and password
 564          */
 565         while (fgets(buf, sizeof(buf), f) != NULL) {
 566                 unsigned strlen_buf;
 567                 unsigned char ch;
 568                 char *after_colon;
 569
 570                 { /* remove all whitespace, and # comments */
 571                         char *p, *p0;
 572
 573                         p0 = buf;
 574                         /* skip non-whitespace beginning. Often the whole line
 575                          * is non-whitespace. We want this case to work fast,
 576                          * without needless copying, therefore we don't merge
 577                          * this operation into next while loop. */
 578                         while ((ch = *p0) != '\0' && ch != '\n' && ch != '#'
 579                          && ch != ' ' && ch != '\t'
 580                         ) {
 581                                 p0++;
 582                         }
 583                         p = p0;
 584                         /* if we enter this loop, we have some whitespace.
 585                          * discard it */
 586                         while (ch != '\0' && ch != '\n' && ch != '#') {
 587                                 if (ch != ' ' && ch != '\t') {
 588                                         *p++ = ch;
 589                                 }
 590                                 ch = *++p0;
 591                         }
 592                         *p = '\0';
 593                         strlen_buf = p - buf;
 594                         if (strlen_buf == 0)
 595                                 continue; /* empty line */
 596                 }
 597
 598                 after_colon = strchr(buf, ':');
 599                 /* strange line? */
 600                 if (after_colon == NULL || *++after_colon == '\0')
 601                         goto config_error;
 602
 603                 ch = (buf[0] & ~0x20); /* toupper if it's a letter */
 604
 605                 if (ch == 'I') {
 606                         if (index_page != index_html)
 607                                 free((char*)index_page);
 608                         index_page = xstrdup(after_colon);
 609                         continue;
 610                 }
 611
 612                 /* do not allow jumping around using H in subdir's configs */
 613                 if (flag == FIRST_PARSE && ch == 'H') {
 614                         home_httpd = xstrdup(after_colon);
 615                         xchdir(home_httpd);
 616                         continue;
 617                 }
 618
 619                 if (ch == 'A' || ch == 'D') {
 620                         Htaccess_IP *pip;
 621
 622                         if (*after_colon == '*') {
 623                                 if (ch == 'D') {
 624                                         /* memorize "deny all" */
 625                                         flg_deny_all = 1;
 626                                 }
 627                                 /* skip assumed "A:*", it is a default anyway */
 628                                 continue;
 629                         }
 630                         /* store "allow/deny IP/mask" line */
 631                         pip = xzalloc(sizeof(*pip));
 632                         if (scan_ip_mask(after_colon, &pip->ip, &pip->mask)) {
 633                                 /* IP{/mask} syntax error detected, protect all */
 634                                 ch = 'D';
 635                                 pip->mask = 0;
 636                         }
 637                         pip->allow_deny = ch;
 638                         if (ch == 'D') {
 639                                 /* Deny:from_IP - prepend */
 640                                 pip->next = ip_a_d;
 641                                 ip_a_d = pip;
 642                         } else {
 643                                 /* A:from_IP - append (thus all D's precedes A's) */
 644                                 Htaccess_IP *prev_IP = ip_a_d;
 645                                 if (prev_IP == NULL) {
 646                                         ip_a_d = pip;
 647                                 } else {
 648                                         while (prev_IP->next)
 649                                                 prev_IP = prev_IP->next;
 650                                         prev_IP->next = pip;
 651                                 }
 652                         }
 653                         continue;
 654                 }
 655
 656 #if ENABLE_FEATURE_HTTPD_ERROR_PAGES
 657                 if (flag == FIRST_PARSE && ch == 'E') {
 658                         unsigned i;
 659                         int status = atoi(buf + 1); /* error status code */
 660
 661                         if (status < HTTP_CONTINUE) {
 662                                 goto config_error;
 663                         }
 664                         /* then error page; find matching status */
 665                         for (i = 0; i < ARRAY_SIZE(http_response_type); i++) {
 666                                 if (http_response_type[i] == status) {
 667                                         /* We chdir to home_httpd, thus no need to
 668                                          * concat_path_file(home_httpd, after_colon)
 669                                          * here */
 670                                         http_error_page[i] = xstrdup(after_colon);
 671                                         break;
 672                                 }
 673                         }
 674                         continue;
 675                 }
 676 #endif
 677
 678 #if ENABLE_FEATURE_HTTPD_PROXY
 679                 if (flag == FIRST_PARSE && ch == 'P') {
 680                         /* P:/url:[http://]hostname[:port]/new/path */
 681                         char *url_from, *host_port, *url_to;
 682                         Htaccess_Proxy *proxy_entry;
 683
 684                         url_from = after_colon;
 685                         host_port = strchr(after_colon, ':');
 686                         if (host_port == NULL) {
 687                                 goto config_error;
 688                         }
 689                         *host_port++ = '\0';
 690                         if (strncmp(host_port, "http://", 7) == 0)
 691                                 host_port += 7;
 692                         if (*host_port == '\0') {
 693                                 goto config_error;
 694                         }
 695                         url_to = strchr(host_port, '/');
 696                         if (url_to == NULL) {
 697                                 goto config_error;
 698                         }
 699                         *url_to = '\0';
 700                         proxy_entry = xzalloc(sizeof(*proxy_entry));
 701                         proxy_entry->url_from = xstrdup(url_from);
 702                         proxy_entry->host_port = xstrdup(host_port);
 703                         *url_to = '/';
 704                         proxy_entry->url_to = xstrdup(url_to);
 705                         proxy_entry->next = proxy;
 706                         proxy = proxy_entry;
 707                         continue;
 708                 }
 709 #endif
 710                 /* the rest of directives are non-alphabetic,
 711                  * must avoid using "toupper'ed" ch */
 712                 ch = buf[0];
 713
 714                 if (ch == '.' /* ".ext:mime/type" */
 715 #if ENABLE_FEATURE_HTTPD_CONFIG_WITH_SCRIPT_INTERPR
 716                  || (ch == '*' && buf[1] == '.') /* "*.php:/path/php" */
 717 #endif
 718                 ) {
 719                         char *p;
 720                         Htaccess *cur;
 721
 722                         cur = xzalloc(sizeof(*cur) /* includes space for NUL */ + strlen_buf);
 723                         strcpy(cur->before_colon, buf);
 724                         p = cur->before_colon + (after_colon - buf);
 725                         p[-1] = '\0';
 726                         cur->after_colon = p;
 727                         if (ch == '.') {
 728                                 /* .mime line: prepend to mime_a list */
 729                                 cur->next = mime_a;
 730                                 mime_a = cur;
 731                         }
 732 #if ENABLE_FEATURE_HTTPD_CONFIG_WITH_SCRIPT_INTERPR
 733                         else {
 734                                 /* script interpreter line: prepend to script_i list */
 735                                 cur->next = script_i;
 736                                 script_i = cur;
 737                         }
 738 #endif
 739                         continue;
 740                 }
 741
 742 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
 743                 if (ch == '/') { /* "/file:user:pass" */
 744                         char *p;
 745                         Htaccess *cur;
 746                         unsigned file_len;
 747
 748                         /* note: path is "" unless we are in SUBDIR parse,
 749                          * otherwise it does NOT start with "/" */
 750                         cur = xzalloc(sizeof(*cur) /* includes space for NUL */
 751                                 + 1 + strlen(path)
 752                                 + strlen_buf
 753                                 );
 754                         /* form "/path/file" */
 755                         sprintf(cur->before_colon, "/%s%.*s",
 756                                 path,
 757                                 (int) (after_colon - buf - 1), /* includes "/", but not ":" */
 758                                 buf);
 759                         /* canonicalize it */
 760                         p = bb_simplify_abs_path_inplace(cur->before_colon);
 761                         file_len = p - cur->before_colon;
 762                         /* add "user:pass" after NUL */
 763                         strcpy(++p, after_colon);
 764                         cur->after_colon = p;
 765
 766                         /* insert cur into g_auth */
 767                         /* g_auth is sorted by decreased filename length */
 768                         {
 769                                 Htaccess *auth, **authp;
 770
 771                                 authp = &g_auth;
 772                                 while ((auth = *authp) != NULL) {
 773                                         if (file_len >= strlen(auth->before_colon)) {
 774                                                 /* insert cur before auth */
 775                                                 cur->next = auth;
 776                                                 break;
 777                                         }
 778                                         authp = &auth->next;
 779                                 }
 780                                 *authp = cur;
 781                         }
 782                         continue;
 783                 }
 784 #endif /* BASIC_AUTH */
 785
 786                 /* the line is not recognized */
 787  config_error:
 788                 bb_error_msg("config error '%s' in '%s'", buf, filename);
 789          } /* while (fgets) */
 790
 791          fclose(f);
 792 }
 793
 794 #if ENABLE_FEATURE_HTTPD_ENCODE_URL_STR
 795 /*
 796  * Given a string, html-encode special characters.
 797  * This is used for the -e command line option to provide an easy way
 798  * for scripts to encode result data without confusing browsers.  The
 799  * returned string pointer is memory allocated by malloc().
 800  *
 801  * Returns a pointer to the encoded string (malloced).
 802  */
 803 static char *encodeString(const char *string)
 804 {
 805         /* take the simple route and encode everything */
 806         /* could possibly scan once to get length.     */
 807         int len = strlen(string);
 808         char *out = xmalloc(len * 6 + 1);
 809         char *p = out;
 810         char ch;
 811
 812         while ((ch = *string++) != '\0') {
 813                 /* very simple check for what to encode */
 814                 if (isalnum(ch))
 815                         *p++ = ch;
 816                 else
 817                         p += sprintf(p, "&#%d;", (unsigned char) ch);
 818         }
 819         *p = '\0';
 820         return out;
 821 }
 822 #endif
 823
 824 /*
 825  * Given a URL encoded string, convert it to plain ascii.
 826  * Since decoding always makes strings smaller, the decode is done in-place.
 827  * Thus, callers should xstrdup() the argument if they do not want the
 828  * argument modified.  The return is the original pointer, allowing this
 829  * function to be easily used as arguments to other functions.
 830  *
 831  * string    The first string to decode.
 832  * option_d  1 if called for httpd -d
 833  *
 834  * Returns a pointer to the decoded string (same as input).
 835  */
 836 static unsigned hex_to_bin(unsigned char c)
 837 {
 838         unsigned v;
 839
 840         v = c - '0';
 841         if (v <= 9)
 842                 return v;
 843         /* c | 0x20: letters to lower case, non-letters
 844          * to (potentially different) non-letters */
 845         v = (unsigned)(c | 0x20) - 'a';
 846         if (v <= 5)
 847                 return v + 10;
 848         return ~0;
 849 /* For testing:
 850 void t(char c) { printf("'%c'(%u) %u\n", c, c, hex_to_bin(c)); }
 851 int main() { t(0x10); t(0x20); t('0'); t('9'); t('A'); t('F'); t('a'); t('f');
 852 t('0'-1); t('9'+1); t('A'-1); t('F'+1); t('a'-1); t('f'+1); return 0; }
 853 */
 854 }
 855 static char *decodeString(char *orig, int option_d)
 856 {
 857         /* note that decoded string is always shorter than original */
 858         char *string = orig;
 859         char *ptr = string;
 860         char c;
 861
 862         while ((c = *ptr++) != '\0') {
 863                 unsigned v;
 864
 865                 if (option_d && c == '+') {
 866                         *string++ = ' ';
 867                         continue;
 868                 }
 869                 if (c != '%') {
 870                         *string++ = c;
 871                         continue;
 872                 }
 873                 v = hex_to_bin(ptr[0]);
 874                 if (v > 15) {
 875  bad_hex:
 876                         if (!option_d)
 877                                 return NULL;
 878                         *string++ = '%';
 879                         continue;
 880                 }
 881                 v = (v * 16) | hex_to_bin(ptr[1]);
 882                 if (v > 255)
 883                         goto bad_hex;
 884                 if (!option_d && (v == '/' || v == '\0')) {
 885                         /* caller takes it as indication of invalid
 886                          * (dangerous wrt exploits) chars */
 887                         return orig + 1;
 888                 }
 889                 *string++ = v;
 890                 ptr += 2;
 891         }
 892         *string = '\0';
 893         return orig;
 894 }
 895
 896 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
 897 /*
 898  * Decode a base64 data stream as per rfc1521.
 899  * Note that the rfc states that non base64 chars are to be ignored.
 900  * Since the decode always results in a shorter size than the input,
 901  * it is OK to pass the input arg as an output arg.
 902  * Parameter: a pointer to a base64 encoded string.
 903  * Decoded data is stored in-place.
 904  */
 905 static void decodeBase64(char *Data)
 906 {
 907         const unsigned char *in = (const unsigned char *)Data;
 908         /* The decoded size will be at most 3/4 the size of the encoded */
 909         unsigned ch = 0;
 910         int i = 0;
 911
 912         while (*in) {
 913                 int t = *in++;
 914
 915                 if (t >= '0' && t <= '9')
 916                         t = t - '0' + 52;
 917                 else if (t >= 'A' && t <= 'Z')
 918                         t = t - 'A';
 919                 else if (t >= 'a' && t <= 'z')
 920                         t = t - 'a' + 26;
 921                 else if (t == '+')
 922                         t = 62;
 923                 else if (t == '/')
 924                         t = 63;
 925                 else if (t == '=')
 926                         t = 0;
 927                 else
 928                         continue;
 929
 930                 ch = (ch << 6) | t;
 931                 i++;
 932                 if (i == 4) {
 933                         *Data++ = (char) (ch >> 16);
 934                         *Data++ = (char) (ch >> 8);
 935                         *Data++ = (char) ch;
 936                         i = 0;
 937                 }
 938         }
 939         *Data = '\0';
 940 }
 941 #endif
 942
 943 /*
 944  * Create a listen server socket on the designated port.
 945  */
 946 static int openServer(void)
 947 {
 948         unsigned n = bb_strtou(bind_addr_or_port, NULL, 10);
 949         if (!errno && n && n <= 0xffff)
 950                 n = create_and_bind_stream_or_die(NULL, n);
 951         else
 952                 n = create_and_bind_stream_or_die(bind_addr_or_port, 80);
 953         xlisten(n, 9);
 954         return n;
 955 }
 956
 957 /*
 958  * Log the connection closure and exit.
 959  */
 960 static void log_and_exit(void) NORETURN;
 961 static void log_and_exit(void)
 962 {
 963         /* Paranoia. IE said to be buggy. It may send some extra data
 964          * or be confused by us just exiting without SHUT_WR. Oh well. */
 965         shutdown(1, SHUT_WR);
 966         /* Why??
 967         (this also messes up stdin when user runs httpd -i from terminal)
 968         ndelay_on(0);
 969         while (read(STDIN_FILENO, iobuf, IOBUF_SIZE) > 0)
 970                 continue;
 971         */
 972
 973         if (verbose > 2)
 974                 bb_error_msg("closed");
 975         _exit(xfunc_error_retval);
 976 }
 977
 978 /*
 979  * Create and send HTTP response headers.
 980  * The arguments are combined and sent as one write operation.  Note that
 981  * IE will puke big-time if the headers are not sent in one packet and the
 982  * second packet is delayed for any reason.
 983  * responseNum - the result code to send.
 984  */
 985 static void send_headers(int responseNum)
 986 {
 987         static const char RFC1123FMT[] ALIGN1 = "%a, %d %b %Y %H:%M:%S GMT";
 988
 989         const char *responseString = "";
 990         const char *infoString = NULL;
 991         const char *mime_type;
 992 #if ENABLE_FEATURE_HTTPD_ERROR_PAGES
 993         const char *error_page = NULL;
 994 #endif
 995         unsigned i;
 996         time_t timer = time(NULL);
 997         char tmp_str[80];
 998         int len;
 999
1000         for (i = 0; i < ARRAY_SIZE(http_response_type); i++) {
1001                 if (http_response_type[i] == responseNum) {
1002                         responseString = http_response[i].name;
1003                         infoString = http_response[i].info;
1004 #if ENABLE_FEATURE_HTTPD_ERROR_PAGES
1005                         error_page = http_error_page[i];
1006 #endif
1007                         break;
1008                 }
1009         }
1010         /* error message is HTML */
1011         mime_type = responseNum == HTTP_OK ?
1012                                 found_mime_type : "text/html";
1013
1014         if (verbose)
1015                 bb_error_msg("response:%u", responseNum);
1016
1017         /* emit the current date */
1018         strftime(tmp_str, sizeof(tmp_str), RFC1123FMT, gmtime(&timer));
1019         len = sprintf(iobuf,
1020                         "HTTP/1.0 %d %s\r\nContent-type: %s\r\n"
1021                         "Date: %s\r\nConnection: close\r\n",
1022                         responseNum, responseString, mime_type, tmp_str);
1023
1024 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
1025         if (responseNum == HTTP_UNAUTHORIZED) {
1026                 len += sprintf(iobuf + len,
1027                                 "WWW-Authenticate: Basic realm=\"%s\"\r\n",
1028                                 g_realm);
1029         }
1030 #endif
1031         if (responseNum == HTTP_MOVED_TEMPORARILY) {
1032                 len += sprintf(iobuf + len, "Location: %s/%s%s\r\n",
1033                                 found_moved_temporarily,
1034                                 (g_query ? "?" : ""),
1035                                 (g_query ? g_query : ""));
1036         }
1037
1038 #if ENABLE_FEATURE_HTTPD_ERROR_PAGES
1039         if (error_page && access(error_page, R_OK) == 0) {
1040                 strcat(iobuf, "\r\n");
1041                 len += 2;
1042
1043                 if (DEBUG)
1044                         fprintf(stderr, "headers: '%s'\n", iobuf);
1045                 full_write(STDOUT_FILENO, iobuf, len);
1046                 if (DEBUG)
1047                         fprintf(stderr, "writing error page: '%s'\n", error_page);
1048                 return send_file_and_exit(error_page, SEND_BODY);
1049         }
1050 #endif
1051
1052         if (file_size != -1) {    /* file */
1053                 strftime(tmp_str, sizeof(tmp_str), RFC1123FMT, gmtime(&last_mod));
1054 #if ENABLE_FEATURE_HTTPD_RANGES
1055                 if (responseNum == HTTP_PARTIAL_CONTENT) {
1056                         len += sprintf(iobuf + len, "Content-Range: bytes %"OFF_FMT"u-%"OFF_FMT"u/%"OFF_FMT"u\r\n",
1057                                         range_start,
1058                                         range_end,
1059                                         file_size);
1060                         file_size = range_end - range_start + 1;
1061                 }
1062 #endif
1063                 len += sprintf(iobuf + len,
1064 #if ENABLE_FEATURE_HTTPD_RANGES
1065                         "Accept-Ranges: bytes\r\n"
1066 #endif
1067                         "Last-Modified: %s\r\n%s %"OFF_FMT"u\r\n",
1068                                 tmp_str,
1069                                 content_gzip ? "Transfer-length:" : "Content-length:",
1070                                 file_size
1071                 );
1072         }
1073
1074         if (content_gzip)
1075                 len += sprintf(iobuf + len, "Content-Encoding: gzip\r\n");
1076
1077         iobuf[len++] = '\r';
1078         iobuf[len++] = '\n';
1079         if (infoString) {
1080                 len += sprintf(iobuf + len,
1081                                 "<HTML><HEAD><TITLE>%d %s</TITLE></HEAD>\n"
1082                                 "<BODY><H1>%d %s</H1>\n%s\n</BODY></HTML>\n",
1083                                 responseNum, responseString,
1084                                 responseNum, responseString, infoString);
1085         }
1086         if (DEBUG)
1087                 fprintf(stderr, "headers: '%s'\n", iobuf);
1088         if (full_write(STDOUT_FILENO, iobuf, len) != len) {
1089                 if (verbose > 1)
1090                         bb_perror_msg("error");
1091                 log_and_exit();
1092         }
1093 }
1094
1095 static void send_headers_and_exit(int responseNum) NORETURN;
1096 static void send_headers_and_exit(int responseNum)
1097 {
1098         IF_FEATURE_HTTPD_GZIP(content_gzip = 0;)
1099         send_headers(responseNum);
1100         log_and_exit();
1101 }
1102
1103 /*
1104  * Read from the socket until '\n' or EOF. '\r' chars are removed.
1105  * '\n' is replaced with NUL.
1106  * Return number of characters read or 0 if nothing is read
1107  * ('\r' and '\n' are not counted).
1108  * Data is returned in iobuf.
1109  */
1110 static int get_line(void)
1111 {
1112         int count = 0;
1113         char c;
1114
1115         alarm(HEADER_READ_TIMEOUT);
1116         while (1) {
1117                 if (hdr_cnt <= 0) {
1118                         hdr_cnt = safe_read(STDIN_FILENO, hdr_buf, sizeof(hdr_buf));
1119                         if (hdr_cnt <= 0)
1120                                 break;
1121                         hdr_ptr = hdr_buf;
1122                 }
1123                 iobuf[count] = c = *hdr_ptr++;
1124                 hdr_cnt--;
1125
1126                 if (c == '\r')
1127                         continue;
1128                 if (c == '\n') {
1129                         iobuf[count] = '\0';
1130                         break;
1131                 }
1132                 if (count < (IOBUF_SIZE - 1))      /* check overflow */
1133                         count++;
1134         }
1135         return count;
1136 }
1137
1138 #if ENABLE_FEATURE_HTTPD_CGI || ENABLE_FEATURE_HTTPD_PROXY
1139
1140 /* gcc 4.2.1 fares better with NOINLINE */
1141 static NOINLINE void cgi_io_loop_and_exit(int fromCgi_rd, int toCgi_wr, int post_len) NORETURN;
1142 static NOINLINE void cgi_io_loop_and_exit(int fromCgi_rd, int toCgi_wr, int post_len)
1143 {
1144         enum { FROM_CGI = 1, TO_CGI = 2 }; /* indexes in pfd[] */
1145         struct pollfd pfd[3];
1146         int out_cnt; /* we buffer a bit of initial CGI output */
1147         int count;
1148
1149         /* iobuf is used for CGI -> network data,
1150          * hdr_buf is for network -> CGI data (POSTDATA) */
1151
1152         /* If CGI dies, we still want to correctly finish reading its output
1153          * and send it to the peer. So please no SIGPIPEs! */
1154         signal(SIGPIPE, SIG_IGN);
1155
1156         // We inconsistently handle a case when more POSTDATA from network
1157         // is coming than we expected. We may give *some part* of that
1158         // extra data to CGI.
1159
1160         //if (hdr_cnt > post_len) {
1161         //      /* We got more POSTDATA from network than we expected */
1162         //      hdr_cnt = post_len;
1163         //}
1164         post_len -= hdr_cnt;
1165         /* post_len - number of POST bytes not yet read from network */
1166
1167         /* NB: breaking out of this loop jumps to log_and_exit() */
1168         out_cnt = 0;
1169         while (1) {
1170                 memset(pfd, 0, sizeof(pfd));
1171
1172                 pfd[FROM_CGI].fd = fromCgi_rd;
1173                 pfd[FROM_CGI].events = POLLIN;
1174
1175                 if (toCgi_wr) {
1176                         pfd[TO_CGI].fd = toCgi_wr;
1177                         if (hdr_cnt > 0) {
1178                                 pfd[TO_CGI].events = POLLOUT;
1179                         } else if (post_len > 0) {
1180                                 pfd[0].events = POLLIN;
1181                         } else {
1182                                 /* post_len <= 0 && hdr_cnt <= 0:
1183                                  * no more POST data to CGI,
1184                                  * let CGI see EOF on CGI's stdin */
1185                                 if (toCgi_wr != fromCgi_rd)
1186                                         close(toCgi_wr);
1187                                 toCgi_wr = 0;
1188                         }
1189                 }
1190
1191                 /* Now wait on the set of sockets */
1192                 count = safe_poll(pfd, toCgi_wr ? TO_CGI+1 : FROM_CGI+1, -1);
1193                 if (count <= 0) {
1194 #if 0
1195                         if (safe_waitpid(pid, &status, WNOHANG) <= 0) {
1196                                 /* Weird. CGI didn't exit and no fd's
1197                                  * are ready, yet poll returned?! */
1198                                 continue;
1199                         }
1200                         if (DEBUG && WIFEXITED(status))
1201                                 bb_error_msg("CGI exited, status=%d", WEXITSTATUS(status));
1202                         if (DEBUG && WIFSIGNALED(status))
1203                                 bb_error_msg("CGI killed, signal=%d", WTERMSIG(status));
1204 #endif
1205                         break;
1206                 }
1207
1208                 if (pfd[TO_CGI].revents) {
1209                         /* hdr_cnt > 0 here due to the way pfd[TO_CGI].events set */
1210                         /* Have data from peer and can write to CGI */
1211                         count = safe_write(toCgi_wr, hdr_ptr, hdr_cnt);
1212                         /* Doesn't happen, we dont use nonblocking IO here
1213                          *if (count < 0 && errno == EAGAIN) {
1214                          *      ...
1215                          *} else */
1216                         if (count > 0) {
1217                                 hdr_ptr += count;
1218                                 hdr_cnt -= count;
1219                         } else {
1220                                 /* EOF/broken pipe to CGI, stop piping POST data */
1221                                 hdr_cnt = post_len = 0;
1222                         }
1223                 }
1224
1225                 if (pfd[0].revents) {
1226                         /* post_len > 0 && hdr_cnt == 0 here */
1227                         /* We expect data, prev data portion is eaten by CGI
1228                          * and there *is* data to read from the peer
1229                          * (POSTDATA) */
1230                         //count = post_len > (int)sizeof(hdr_buf) ? (int)sizeof(hdr_buf) : post_len;
1231                         //count = safe_read(STDIN_FILENO, hdr_buf, count);
1232                         count = safe_read(STDIN_FILENO, hdr_buf, sizeof(hdr_buf));
1233                         if (count > 0) {
1234                                 hdr_cnt = count;
1235                                 hdr_ptr = hdr_buf;
1236                                 post_len -= count;
1237                         } else {
1238                                 /* no more POST data can be read */
1239                                 post_len = 0;
1240                         }
1241                 }
1242
1243                 if (pfd[FROM_CGI].revents) {
1244                         /* There is something to read from CGI */
1245                         char *rbuf = iobuf;
1246
1247                         /* Are we still buffering CGI output? */
1248                         if (out_cnt >= 0) {
1249                                 /* HTTP_200[] has single "\r\n" at the end.
1250                                  * According to http://hoohoo.ncsa.uiuc.edu/cgi/out.html,
1251                                  * CGI scripts MUST send their own header terminated by
1252                                  * empty line, then data. That's why we have only one
1253                                  * <cr><lf> pair here. We will output "200 OK" line
1254                                  * if needed, but CGI still has to provide blank line
1255                                  * between header and body */
1256
1257                                 /* Must use safe_read, not full_read, because
1258                                  * CGI may output a few first bytes and then wait
1259                                  * for POSTDATA without closing stdout.
1260                                  * With full_read we may wait here forever. */
1261                                 count = safe_read(fromCgi_rd, rbuf + out_cnt, PIPE_BUF - 8);
1262                                 if (count <= 0) {
1263                                         /* eof (or error) and there was no "HTTP",
1264                                          * so write it, then write received data */
1265                                         if (out_cnt) {
1266                                                 full_write(STDOUT_FILENO, HTTP_200, sizeof(HTTP_200)-1);
1267                                                 full_write(STDOUT_FILENO, rbuf, out_cnt);
1268                                         }
1269                                         break; /* CGI stdout is closed, exiting */
1270                                 }
1271                                 out_cnt += count;
1272                                 count = 0;
1273                                 /* "Status" header format is: "Status: 302 Redirected\r\n" */
1274                                 if (out_cnt >= 8 && memcmp(rbuf, "Status: ", 8) == 0) {
1275                                         /* send "HTTP/1.0 " */
1276                                         if (full_write(STDOUT_FILENO, HTTP_200, 9) != 9)
1277                                                 break;
1278                                         rbuf += 8; /* skip "Status: " */
1279                                         count = out_cnt - 8;
1280                                         out_cnt = -1; /* buffering off */
1281                                 } else if (out_cnt >= 4) {
1282                                         /* Did CGI add "HTTP"? */
1283                                         if (memcmp(rbuf, HTTP_200, 4) != 0) {
1284                                                 /* there is no "HTTP", do it ourself */
1285                                                 if (full_write(STDOUT_FILENO, HTTP_200, sizeof(HTTP_200)-1) != sizeof(HTTP_200)-1)
1286                                                         break;
1287                                         }
1288                                         /* Commented out:
1289                                         if (!strstr(rbuf, "ontent-")) {
1290                                                 full_write(s, "Content-type: text/plain\r\n\r\n", 28);
1291                                         }
1292                                          * Counter-example of valid CGI without Content-type:
1293                                          * echo -en "HTTP/1.0 302 Found\r\n"
1294                                          * echo -en "Location: http://www.busybox.net\r\n"
1295                                          * echo -en "\r\n"
1296                                          */
1297                                         count = out_cnt;
1298                                         out_cnt = -1; /* buffering off */
1299                                 }
1300                         } else {
1301                                 count = safe_read(fromCgi_rd, rbuf, PIPE_BUF);
1302                                 if (count <= 0)
1303                                         break;  /* eof (or error) */
1304                         }
1305                         if (full_write(STDOUT_FILENO, rbuf, count) != count)
1306                                 break;
1307                         if (DEBUG)
1308                                 fprintf(stderr, "cgi read %d bytes: '%.*s'\n", count, count, rbuf);
1309                 } /* if (pfd[FROM_CGI].revents) */
1310         } /* while (1) */
1311         log_and_exit();
1312 }
1313 #endif
1314
1315 #if ENABLE_FEATURE_HTTPD_CGI
1316
1317 static void setenv1(const char *name, const char *value)
1318 {
1319         setenv(name, value ? value : "", 1);
1320 }
1321
1322 /*
1323  * Spawn CGI script, forward CGI's stdin/out <=> network
1324  *
1325  * Environment variables are set up and the script is invoked with pipes
1326  * for stdin/stdout.  If a POST is being done the script is fed the POST
1327  * data in addition to setting the QUERY_STRING variable (for GETs or POSTs).
1328  *
1329  * Parameters:
1330  * const char *url              The requested URL (with leading /).
1331  * int post_len                 Length of the POST body.
1332  * const char *cookie           For set HTTP_COOKIE.
1333  * const char *content_type     For set CONTENT_TYPE.
1334  */
1335 static void send_cgi_and_exit(
1336                 const char *url,
1337                 const char *request,
1338                 int post_len,
1339                 const char *cookie,
1340                 const char *content_type) NORETURN;
1341 static void send_cgi_and_exit(
1342                 const char *url,
1343                 const char *request,
1344                 int post_len,
1345                 const char *cookie,
1346                 const char *content_type)
1347 {
1348         struct fd_pair fromCgi;  /* CGI -> httpd pipe */
1349         struct fd_pair toCgi;    /* httpd -> CGI pipe */
1350         char *script;
1351         int pid;
1352
1353         /* Make a copy. NB: caller guarantees:
1354          * url[0] == '/', url[1] != '/' */
1355         url = xstrdup(url);
1356
1357         /*
1358          * We are mucking with environment _first_ and then vfork/exec,
1359          * this allows us to use vfork safely. Parent doesn't care about
1360          * these environment changes anyway.
1361          */
1362
1363         /* Check for [dirs/]script.cgi/PATH_INFO */
1364         script = (char*)url;
1365         while ((script = strchr(script + 1, '/')) != NULL) {
1366                 *script = '\0';
1367                 if (!is_directory(url + 1, 1, NULL)) {
1368                         /* not directory, found script.cgi/PATH_INFO */
1369                         *script = '/';
1370                         break;
1371                 }
1372                 *script = '/'; /* is directory, find next '/' */
1373         }
1374         setenv1("PATH_INFO", script);   /* set to /PATH_INFO or "" */
1375         setenv1("REQUEST_METHOD", request);
1376         if (g_query) {
1377                 putenv(xasprintf("%s=%s?%s", "REQUEST_URI", url, g_query));
1378         } else {
1379                 setenv1("REQUEST_URI", url);
1380         }
1381         if (script != NULL)
1382                 *script = '\0';         /* cut off /PATH_INFO */
1383
1384         /* SCRIPT_FILENAME is required by PHP in CGI mode */
1385         if (home_httpd[0] == '/') {
1386                 char *fullpath = concat_path_file(home_httpd, url);
1387                 setenv1("SCRIPT_FILENAME", fullpath);
1388         }
1389         /* set SCRIPT_NAME as full path: /cgi-bin/dirs/script.cgi */
1390         setenv1("SCRIPT_NAME", url);
1391         /* http://hoohoo.ncsa.uiuc.edu/cgi/env.html:
1392          * QUERY_STRING: The information which follows the ? in the URL
1393          * which referenced this script. This is the query information.
1394          * It should not be decoded in any fashion. This variable
1395          * should always be set when there is query information,
1396          * regardless of command line decoding. */
1397         /* (Older versions of bbox seem to do some decoding) */
1398         setenv1("QUERY_STRING", g_query);
1399         putenv((char*)"SERVER_SOFTWARE=busybox httpd/"BB_VER);
1400         putenv((char*)"SERVER_PROTOCOL=HTTP/1.0");
1401         putenv((char*)"GATEWAY_INTERFACE=CGI/1.1");
1402         /* Having _separate_ variables for IP and port defeats
1403          * the purpose of having socket abstraction. Which "port"
1404          * are you using on Unix domain socket?
1405          * IOW - REMOTE_PEER="1.2.3.4:56" makes much more sense.
1406          * Oh well... */
1407         {
1408                 char *p = rmt_ip_str ? rmt_ip_str : (char*)"";
1409                 char *cp = strrchr(p, ':');
1410                 if (ENABLE_FEATURE_IPV6 && cp && strchr(cp, ']'))
1411                         cp = NULL;
1412                 if (cp) *cp = '\0'; /* delete :PORT */
1413                 setenv1("REMOTE_ADDR", p);
1414                 if (cp) {
1415                         *cp = ':';
1416 #if ENABLE_FEATURE_HTTPD_SET_REMOTE_PORT_TO_ENV
1417                         setenv1("REMOTE_PORT", cp + 1);
1418 #endif
1419                 }
1420         }
1421         setenv1("HTTP_USER_AGENT", user_agent);
1422         if (http_accept)
1423                 setenv1("HTTP_ACCEPT", http_accept);
1424         if (http_accept_language)
1425                 setenv1("HTTP_ACCEPT_LANGUAGE", http_accept_language);
1426         if (post_len)
1427                 putenv(xasprintf("CONTENT_LENGTH=%d", post_len));
1428         if (cookie)
1429                 setenv1("HTTP_COOKIE", cookie);
1430         if (content_type)
1431                 setenv1("CONTENT_TYPE", content_type);
1432 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
1433         if (remoteuser) {
1434                 setenv1("REMOTE_USER", remoteuser);
1435                 putenv((char*)"AUTH_TYPE=Basic");
1436         }
1437 #endif
1438         if (referer)
1439                 setenv1("HTTP_REFERER", referer);
1440         setenv1("HTTP_HOST", host); /* set to "" if NULL */
1441         /* setenv1("SERVER_NAME", safe_gethostname()); - don't do this,
1442          * just run "env SERVER_NAME=xyz httpd ..." instead */
1443
1444         xpiped_pair(fromCgi);
1445         xpiped_pair(toCgi);
1446
1447         pid = vfork();
1448         if (pid < 0) {
1449                 /* TODO: log perror? */
1450                 log_and_exit();
1451         }
1452
1453         if (!pid) {
1454                 /* Child process */
1455                 char *argv[3];
1456
1457                 xfunc_error_retval = 242;
1458
1459                 /* NB: close _first_, then move fds! */
1460                 close(toCgi.wr);
1461                 close(fromCgi.rd);
1462                 xmove_fd(toCgi.rd, 0);  /* replace stdin with the pipe */
1463                 xmove_fd(fromCgi.wr, 1);  /* replace stdout with the pipe */
1464                 /* User seeing stderr output can be a security problem.
1465                  * If CGI really wants that, it can always do dup itself. */
1466                 /* dup2(1, 2); */
1467
1468                 /* Chdiring to script's dir */
1469                 script = strrchr(url, '/');
1470                 if (script != url) { /* paranoia */
1471                         *script = '\0';
1472                         if (chdir(url + 1) != 0) {
1473                                 bb_perror_msg("chdir(%s)", url + 1);
1474                                 goto error_execing_cgi;
1475                         }
1476                         // not needed: *script = '/';
1477                 }
1478                 script++;
1479
1480                 /* set argv[0] to name without path */
1481                 argv[0] = script;
1482                 argv[1] = NULL;
1483
1484 #if ENABLE_FEATURE_HTTPD_CONFIG_WITH_SCRIPT_INTERPR
1485                 {
1486                         char *suffix = strrchr(script, '.');
1487
1488                         if (suffix) {
1489                                 Htaccess *cur;
1490                                 for (cur = script_i; cur; cur = cur->next) {
1491                                         if (strcmp(cur->before_colon + 1, suffix) == 0) {
1492                                                 /* found interpreter name */
1493                                                 argv[0] = cur->after_colon;
1494                                                 argv[1] = script;
1495                                                 argv[2] = NULL;
1496                                                 break;
1497                                         }
1498                                 }
1499                         }
1500                 }
1501 #endif
1502                 /* restore default signal dispositions for CGI process */
1503                 bb_signals(0
1504                         | (1 << SIGCHLD)
1505                         | (1 << SIGPIPE)
1506                         | (1 << SIGHUP)
1507                         , SIG_DFL);
1508
1509                 /* _NOT_ execvp. We do not search PATH. argv[0] is a filename
1510                  * without any dir components and will only match a file
1511                  * in the current directory */
1512                 execv(argv[0], argv);
1513                 if (verbose)
1514                         bb_perror_msg("can't execute '%s'", argv[0]);
1515  error_execing_cgi:
1516                 /* send to stdout
1517                  * (we are CGI here, our stdout is pumped to the net) */
1518                 send_headers_and_exit(HTTP_NOT_FOUND);
1519         } /* end child */
1520
1521         /* Parent process */
1522
1523         /* Restore variables possibly changed by child */
1524         xfunc_error_retval = 0;
1525
1526         /* Pump data */
1527         close(fromCgi.wr);
1528         close(toCgi.rd);
1529         cgi_io_loop_and_exit(fromCgi.rd, toCgi.wr, post_len);
1530 }
1531
1532 #endif          /* FEATURE_HTTPD_CGI */
1533
1534 /*
1535  * Send a file response to a HTTP request, and exit
1536  *
1537  * Parameters:
1538  * const char *url  The requested URL (with leading /).
1539  * what             What to send (headers/body/both).
1540  */
1541 static NOINLINE void send_file_and_exit(const char *url, int what)
1542 {
1543         char *suffix;
1544         int fd;
1545         ssize_t count;
1546
1547         if (content_gzip) {
1548                 /* does <url>.gz exist? Then use it instead */
1549                 char *gzurl = xasprintf("%s.gz", url);
1550                 fd = open(gzurl, O_RDONLY);
1551                 free(gzurl);
1552                 if (fd != -1) {
1553                         struct stat sb;
1554                         fstat(fd, &sb);
1555                         file_size = sb.st_size;
1556                         last_mod = sb.st_mtime;
1557                 } else {
1558                         IF_FEATURE_HTTPD_GZIP(content_gzip = 0;)
1559                         fd = open(url, O_RDONLY);
1560                 }
1561         } else {
1562                 fd = open(url, O_RDONLY);
1563         }
1564         if (fd < 0) {
1565                 if (DEBUG)
1566                         bb_perror_msg("can't open '%s'", url);
1567                 /* Error pages are sent by using send_file_and_exit(SEND_BODY).
1568                  * IOW: it is unsafe to call send_headers_and_exit
1569                  * if what is SEND_BODY! Can recurse! */
1570                 if (what != SEND_BODY)
1571                         send_headers_and_exit(HTTP_NOT_FOUND);
1572                 log_and_exit();
1573         }
1574         /* If you want to know about EPIPE below
1575          * (happens if you abort downloads from local httpd): */
1576         signal(SIGPIPE, SIG_IGN);
1577
1578         /* If not found, default is "application/octet-stream" */
1579         found_mime_type = "application/octet-stream";
1580         suffix = strrchr(url, '.');
1581         if (suffix) {
1582                 static const char suffixTable[] ALIGN1 =
1583                         /* Shorter suffix must be first:
1584                          * ".html.htm" will fail for ".htm"
1585                          */
1586                         ".txt.h.c.cc.cpp\0" "text/plain\0"
1587                         /* .htm line must be after .h line */
1588                         ".htm.html\0" "text/html\0"
1589                         ".jpg.jpeg\0" "image/jpeg\0"
1590                         ".gif\0"      "image/gif\0"
1591                         ".png\0"      "image/png\0"
1592                         /* .css line must be after .c line */
1593                         ".css\0"      "text/css\0"
1594                         ".wav\0"      "audio/wav\0"
1595                         ".avi\0"      "video/x-msvideo\0"
1596                         ".qt.mov\0"   "video/quicktime\0"
1597                         ".mpe.mpeg\0" "video/mpeg\0"
1598                         ".mid.midi\0" "audio/midi\0"
1599                         ".mp3\0"      "audio/mpeg\0"
1600 #if 0  /* unpopular */
1601                         ".au\0"       "audio/basic\0"
1602                         ".pac\0"      "application/x-ns-proxy-autoconfig\0"
1603                         ".vrml.wrl\0" "model/vrml\0"
1604 #endif
1605                         /* compiler adds another "\0" here */
1606                 ;
1607                 Htaccess *cur;
1608
1609                 /* Examine built-in table */
1610                 const char *table = suffixTable;
1611                 const char *table_next;
1612                 for (; *table; table = table_next) {
1613                         const char *try_suffix;
1614                         const char *mime_type;
1615                         mime_type  = table + strlen(table) + 1;
1616                         table_next = mime_type + strlen(mime_type) + 1;
1617                         try_suffix = strstr(table, suffix);
1618                         if (!try_suffix)
1619                                 continue;
1620                         try_suffix += strlen(suffix);
1621                         if (*try_suffix == '\0' || *try_suffix == '.') {
1622                                 found_mime_type = mime_type;
1623                                 break;
1624                         }
1625                         /* Example: strstr(table, ".av") != NULL, but it
1626                          * does not match ".avi" after all and we end up here.
1627                          * The table is arranged so that in this case we know
1628                          * that it can't match anything in the following lines,
1629                          * and we stop the search: */
1630                         break;
1631                 }
1632                 /* ...then user's table */
1633                 for (cur = mime_a; cur; cur = cur->next) {
1634                         if (strcmp(cur->before_colon, suffix) == 0) {
1635                                 found_mime_type = cur->after_colon;
1636                                 break;
1637                         }
1638                 }
1639         }
1640
1641         if (DEBUG)
1642                 bb_error_msg("sending file '%s' content-type: %s",
1643                         url, found_mime_type);
1644
1645 #if ENABLE_FEATURE_HTTPD_RANGES
1646         if (what == SEND_BODY /* err pages and ranges don't mix */
1647          || content_gzip /* we are sending compressed page: can't do ranges */  ///why?
1648         ) {
1649                 range_start = 0;
1650         }
1651         range_len = MAXINT(off_t);
1652         if (range_start) {
1653                 if (!range_end) {
1654                         range_end = file_size - 1;
1655                 }
1656                 if (range_end < range_start
1657                  || lseek(fd, range_start, SEEK_SET) != range_start
1658                 ) {
1659                         lseek(fd, 0, SEEK_SET);
1660                         range_start = 0;
1661                 } else {
1662                         range_len = range_end - range_start + 1;
1663                         send_headers(HTTP_PARTIAL_CONTENT);
1664                         what = SEND_BODY;
1665                 }
1666         }
1667 #endif
1668         if (what & SEND_HEADERS)
1669                 send_headers(HTTP_OK);
1670 #if ENABLE_FEATURE_HTTPD_USE_SENDFILE
1671         {
1672                 off_t offset = range_start;
1673                 while (1) {
1674                         /* sz is rounded down to 64k */
1675                         ssize_t sz = MAXINT(ssize_t) - 0xffff;
1676                         IF_FEATURE_HTTPD_RANGES(if (sz > range_len) sz = range_len;)
1677                         count = sendfile(STDOUT_FILENO, fd, &offset, sz);
1678                         if (count < 0) {
1679                                 if (offset == range_start)
1680                                         break; /* fall back to read/write loop */
1681                                 goto fin;
1682                         }
1683                         IF_FEATURE_HTTPD_RANGES(range_len -= sz;)
1684                         if (count == 0 || range_len == 0)
1685                                 log_and_exit();
1686                 }
1687         }
1688 #endif
1689         while ((count = safe_read(fd, iobuf, IOBUF_SIZE)) > 0) {
1690                 ssize_t n;
1691                 IF_FEATURE_HTTPD_RANGES(if (count > range_len) count = range_len;)
1692                 n = full_write(STDOUT_FILENO, iobuf, count);
1693                 if (count != n)
1694                         break;
1695                 IF_FEATURE_HTTPD_RANGES(range_len -= count;)
1696                 if (range_len == 0)
1697                         break;
1698         }
1699         if (count < 0) {
1700  IF_FEATURE_HTTPD_USE_SENDFILE(fin:)
1701                 if (verbose > 1)
1702                         bb_perror_msg("error");
1703         }
1704         log_and_exit();
1705 }
1706
1707 static int checkPermIP(void)
1708 {
1709         Htaccess_IP *cur;
1710
1711         for (cur = ip_a_d; cur; cur = cur->next) {
1712 #if DEBUG
1713                 fprintf(stderr,
1714                         "checkPermIP: '%s' ? '%u.%u.%u.%u/%u.%u.%u.%u'\n",
1715                         rmt_ip_str,
1716                         (unsigned char)(cur->ip >> 24),
1717                         (unsigned char)(cur->ip >> 16),
1718                         (unsigned char)(cur->ip >> 8),
1719                         (unsigned char)(cur->ip),
1720                         (unsigned char)(cur->mask >> 24),
1721                         (unsigned char)(cur->mask >> 16),
1722                         (unsigned char)(cur->mask >> 8),
1723                         (unsigned char)(cur->mask)
1724                 );
1725 #endif
1726                 if ((rmt_ip & cur->mask) == cur->ip)
1727                         return (cur->allow_deny == 'A'); /* A -> 1 */
1728         }
1729
1730         return !flg_deny_all; /* depends on whether we saw "D:*" */
1731 }
1732
1733 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
1734 /*
1735  * Config file entries are of the form "/<path>:<user>:<passwd>".
1736  * If config file has no prefix match for path, access is allowed.
1737  *
1738  * path                 The file path
1739  * user_and_passwd      "user:passwd" to validate
1740  *
1741  * Returns 1 if user_and_passwd is OK.
1742  */
1743 static int check_user_passwd(const char *path, const char *user_and_passwd)
1744 {
1745         Htaccess *cur;
1746         const char *prev = NULL;
1747
1748         for (cur = g_auth; cur; cur = cur->next) {
1749                 const char *dir_prefix;
1750                 size_t len;
1751
1752                 dir_prefix = cur->before_colon;
1753
1754                 /* WHY? */
1755                 /* If already saw a match, don't accept other different matches */
1756                 if (prev && strcmp(prev, dir_prefix) != 0)
1757                         continue;
1758
1759                 if (DEBUG)
1760                         fprintf(stderr, "checkPerm: '%s' ? '%s'\n", dir_prefix, user_and_passwd);
1761
1762                 /* If it's not a prefix match, continue searching */
1763                 len = strlen(dir_prefix);
1764                 if (len != 1 /* dir_prefix "/" matches all, don't need to check */
1765                  && (strncmp(dir_prefix, path, len) != 0
1766                     || (path[len] != '/' && path[len] != '\0'))
1767                 ) {
1768                         continue;
1769                 }
1770
1771                 /* Path match found */
1772                 prev = dir_prefix;
1773
1774                 if (ENABLE_FEATURE_HTTPD_AUTH_MD5) {
1775                         char *md5_passwd;
1776
1777                         md5_passwd = strchr(cur->after_colon, ':');
1778                         if (md5_passwd && md5_passwd[1] == '$' && md5_passwd[2] == '1'
1779                          && md5_passwd[3] == '$' && md5_passwd[4]
1780                         ) {
1781                                 char *encrypted;
1782                                 int r, user_len_p1;
1783
1784                                 md5_passwd++;
1785                                 user_len_p1 = md5_passwd - cur->after_colon;
1786                                 /* comparing "user:" */
1787                                 if (strncmp(cur->after_colon, user_and_passwd, user_len_p1) != 0) {
1788                                         continue;
1789                                 }
1790
1791                                 encrypted = pw_encrypt(
1792                                         user_and_passwd + user_len_p1 /* cleartext pwd from user */,
1793                                         md5_passwd /*salt */, 1 /* cleanup */);
1794                                 r = strcmp(encrypted, md5_passwd);
1795                                 free(encrypted);
1796                                 if (r == 0)
1797                                         goto set_remoteuser_var; /* Ok */
1798                                 continue;
1799                         }
1800                 }
1801
1802                 /* Comparing plaintext "user:pass" in one go */
1803                 if (strcmp(cur->after_colon, user_and_passwd) == 0) {
1804  set_remoteuser_var:
1805                         remoteuser = xstrndup(user_and_passwd,
1806                                         strchrnul(user_and_passwd, ':') - user_and_passwd);
1807                         return 1; /* Ok */
1808                 }
1809         } /* for */
1810
1811         /* 0(bad) if prev is set: matches were found but passwd was wrong */
1812         return (prev == NULL);
1813 }
1814 #endif  /* FEATURE_HTTPD_BASIC_AUTH */
1815
1816 #if ENABLE_FEATURE_HTTPD_PROXY
1817 static Htaccess_Proxy *find_proxy_entry(const char *url)
1818 {
1819         Htaccess_Proxy *p;
1820         for (p = proxy; p; p = p->next) {
1821                 if (strncmp(url, p->url_from, strlen(p->url_from)) == 0)
1822                         return p;
1823         }
1824         return NULL;
1825 }
1826 #endif
1827
1828 /*
1829  * Handle timeouts
1830  */
1831 static void send_REQUEST_TIMEOUT_and_exit(int sig) NORETURN;
1832 static void send_REQUEST_TIMEOUT_and_exit(int sig UNUSED_PARAM)
1833 {
1834         send_headers_and_exit(HTTP_REQUEST_TIMEOUT);
1835 }
1836
1837 /*
1838  * Handle an incoming http request and exit.
1839  */
1840 static void handle_incoming_and_exit(const len_and_sockaddr *fromAddr) NORETURN;
1841 static void handle_incoming_and_exit(const len_and_sockaddr *fromAddr)
1842 {
1843         static const char request_GET[] ALIGN1 = "GET";
1844         struct stat sb;
1845         char *urlcopy;
1846         char *urlp;
1847         char *tptr;
1848 #if ENABLE_FEATURE_HTTPD_CGI
1849         static const char request_HEAD[] ALIGN1 = "HEAD";
1850         const char *prequest;
1851         char *cookie = NULL;
1852         char *content_type = NULL;
1853         unsigned long length = 0;
1854 #elif ENABLE_FEATURE_HTTPD_PROXY
1855 #define prequest request_GET
1856         unsigned long length = 0;
1857 #endif
1858 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
1859         smallint authorized = -1;
1860 #endif
1861         smallint ip_allowed;
1862         char http_major_version;
1863 #if ENABLE_FEATURE_HTTPD_PROXY
1864         char http_minor_version;
1865         char *header_buf = header_buf; /* for gcc */
1866         char *header_ptr = header_ptr;
1867         Htaccess_Proxy *proxy_entry;
1868 #endif
1869
1870         /* Allocation of iobuf is postponed until now
1871          * (IOW, server process doesn't need to waste 8k) */
1872         iobuf = xmalloc(IOBUF_SIZE);
1873
1874         rmt_ip = 0;
1875         if (fromAddr->u.sa.sa_family == AF_INET) {
1876                 rmt_ip = ntohl(fromAddr->u.sin.sin_addr.s_addr);
1877         }
1878 #if ENABLE_FEATURE_IPV6
1879         if (fromAddr->u.sa.sa_family == AF_INET6
1880          && fromAddr->u.sin6.sin6_addr.s6_addr32[0] == 0
1881          && fromAddr->u.sin6.sin6_addr.s6_addr32[1] == 0
1882          && ntohl(fromAddr->u.sin6.sin6_addr.s6_addr32[2]) == 0xffff)
1883                 rmt_ip = ntohl(fromAddr->u.sin6.sin6_addr.s6_addr32[3]);
1884 #endif
1885         if (ENABLE_FEATURE_HTTPD_CGI || DEBUG || verbose) {
1886                 /* NB: can be NULL (user runs httpd -i by hand?) */
1887                 rmt_ip_str = xmalloc_sockaddr2dotted(&fromAddr->u.sa);
1888         }
1889         if (verbose) {
1890                 /* this trick makes -v logging much simpler */
1891                 if (rmt_ip_str)
1892                         applet_name = rmt_ip_str;
1893                 if (verbose > 2)
1894                         bb_error_msg("connected");
1895         }
1896
1897         /* Install timeout handler. get_line() needs it. */
1898         signal(SIGALRM, send_REQUEST_TIMEOUT_and_exit);
1899
1900         if (!get_line()) /* EOF or error or empty line */
1901                 send_headers_and_exit(HTTP_BAD_REQUEST);
1902
1903         /* Determine type of request (GET/POST) */
1904         urlp = strpbrk(iobuf, " \t");
1905         if (urlp == NULL)
1906                 send_headers_and_exit(HTTP_BAD_REQUEST);
1907         *urlp++ = '\0';
1908 #if ENABLE_FEATURE_HTTPD_CGI
1909         prequest = request_GET;
1910         if (strcasecmp(iobuf, prequest) != 0) {
1911                 prequest = request_HEAD;
1912                 if (strcasecmp(iobuf, prequest) != 0) {
1913                         prequest = "POST";
1914                         if (strcasecmp(iobuf, prequest) != 0)
1915                                 send_headers_and_exit(HTTP_NOT_IMPLEMENTED);
1916                 }
1917         }
1918 #else
1919         if (strcasecmp(iobuf, request_GET) != 0)
1920                 send_headers_and_exit(HTTP_NOT_IMPLEMENTED);
1921 #endif
1922         urlp = skip_whitespace(urlp);
1923         if (urlp[0] != '/')
1924                 send_headers_and_exit(HTTP_BAD_REQUEST);
1925
1926         /* Find end of URL and parse HTTP version, if any */
1927         http_major_version = '0';
1928         IF_FEATURE_HTTPD_PROXY(http_minor_version = '0';)
1929         tptr = strchrnul(urlp, ' ');
1930         /* Is it " HTTP/"? */
1931         if (tptr[0] && strncmp(tptr + 1, HTTP_200, 5) == 0) {
1932                 http_major_version = tptr[6];
1933                 IF_FEATURE_HTTPD_PROXY(http_minor_version = tptr[8];)
1934         }
1935         *tptr = '\0';
1936
1937         /* Copy URL from after "GET "/"POST " to stack-allocated char[] */
1938         urlcopy = alloca((tptr - urlp) + 2 + strlen(index_page));
1939         /*if (urlcopy == NULL)
1940          *      send_headers_and_exit(HTTP_INTERNAL_SERVER_ERROR);*/
1941         strcpy(urlcopy, urlp);
1942         /* NB: urlcopy ptr is never changed after this */
1943
1944         /* Extract url args if present */
1945         g_query = NULL;
1946         tptr = strchr(urlcopy, '?');
1947         if (tptr) {
1948                 *tptr++ = '\0';
1949                 g_query = tptr;
1950         }
1951
1952         /* Decode URL escape sequences */
1953         tptr = decodeString(urlcopy, 0);
1954         if (tptr == NULL)
1955                 send_headers_and_exit(HTTP_BAD_REQUEST);
1956         if (tptr == urlcopy + 1) {
1957                 /* '/' or NUL is encoded */
1958                 send_headers_and_exit(HTTP_NOT_FOUND);
1959         }
1960
1961         /* Canonicalize path */
1962         /* Algorithm stolen from libbb bb_simplify_path(),
1963          * but don't strdup, retain trailing slash, protect root */
1964         urlp = tptr = urlcopy;
1965         do {
1966                 if (*urlp == '/') {
1967                         /* skip duplicate (or initial) slash */
1968                         if (*tptr == '/') {
1969                                 continue;
1970                         }
1971                         if (*tptr == '.') {
1972                                 /* skip extra "/./" */
1973                                 if (tptr[1] == '/' || !tptr[1]) {
1974                                         continue;
1975                                 }
1976                                 /* "..": be careful */
1977                                 if (tptr[1] == '.' && (tptr[2] == '/' || !tptr[2])) {
1978                                         ++tptr;
1979                                         if (urlp == urlcopy) /* protect root */
1980                                                 send_headers_and_exit(HTTP_BAD_REQUEST);
1981                                         while (*--urlp != '/') /* omit previous dir */;
1982                                                 continue;
1983                                 }
1984                         }
1985                 }
1986                 *++urlp = *tptr;
1987         } while (*++tptr);
1988         *++urlp = '\0';       /* terminate after last character */
1989
1990         /* If URL is a directory, add '/' */
1991         if (urlp[-1] != '/') {
1992                 if (is_directory(urlcopy + 1, 1, NULL)) {
1993                         found_moved_temporarily = urlcopy;
1994                 }
1995         }
1996
1997         /* Log it */
1998         if (verbose > 1)
1999                 bb_error_msg("url:%s", urlcopy);
2000
2001         tptr = urlcopy;
2002         ip_allowed = checkPermIP();
2003         while (ip_allowed && (tptr = strchr(tptr + 1, '/')) != NULL) {
2004                 /* have path1/path2 */
2005                 *tptr = '\0';
2006                 if (is_directory(urlcopy + 1, 1, NULL)) {
2007                         /* may have subdir config */
2008                         parse_conf(urlcopy + 1, SUBDIR_PARSE);
2009                         ip_allowed = checkPermIP();
2010                 }
2011                 *tptr = '/';
2012         }
2013
2014 #if ENABLE_FEATURE_HTTPD_PROXY
2015         proxy_entry = find_proxy_entry(urlcopy);
2016         if (proxy_entry)
2017                 header_buf = header_ptr = xmalloc(IOBUF_SIZE);
2018 #endif
2019
2020         if (http_major_version >= '0') {
2021                 /* Request was with "... HTTP/nXXX", and n >= 0 */
2022
2023                 /* Read until blank line */
2024                 while (1) {
2025                         if (!get_line())
2026                                 break; /* EOF or error or empty line */
2027                         if (DEBUG)
2028                                 bb_error_msg("header: '%s'", iobuf);
2029
2030 #if ENABLE_FEATURE_HTTPD_PROXY
2031                         /* We need 2 more bytes for yet another "\r\n" -
2032                          * see near fdprintf(proxy_fd...) further below */
2033                         if (proxy_entry && (header_ptr - header_buf) < IOBUF_SIZE - 2) {
2034                                 int len = strlen(iobuf);
2035                                 if (len > IOBUF_SIZE - (header_ptr - header_buf) - 4)
2036                                         len = IOBUF_SIZE - (header_ptr - header_buf) - 4;
2037                                 memcpy(header_ptr, iobuf, len);
2038                                 header_ptr += len;
2039                                 header_ptr[0] = '\r';
2040                                 header_ptr[1] = '\n';
2041                                 header_ptr += 2;
2042                         }
2043 #endif
2044
2045 #if ENABLE_FEATURE_HTTPD_CGI || ENABLE_FEATURE_HTTPD_PROXY
2046                         /* Try and do our best to parse more lines */
2047                         if ((STRNCASECMP(iobuf, "Content-length:") == 0)) {
2048                                 /* extra read only for POST */
2049                                 if (prequest != request_GET
2050 # if ENABLE_FEATURE_HTTPD_CGI
2051                                  && prequest != request_HEAD
2052 # endif
2053                                 ) {
2054                                         tptr = skip_whitespace(iobuf + sizeof("Content-length:") - 1);
2055                                         if (!tptr[0])
2056                                                 send_headers_and_exit(HTTP_BAD_REQUEST);
2057                                         /* not using strtoul: it ignores leading minus! */
2058                                         length = bb_strtou(tptr, NULL, 10);
2059                                         /* length is "ulong", but we need to pass it to int later */
2060                                         if (errno || length > INT_MAX)
2061                                                 send_headers_and_exit(HTTP_BAD_REQUEST);
2062                                 }
2063                         }
2064 #endif
2065 #if ENABLE_FEATURE_HTTPD_CGI
2066                         else if (STRNCASECMP(iobuf, "Cookie:") == 0) {
2067                                 cookie = xstrdup(skip_whitespace(iobuf + sizeof("Cookie:")-1));
2068                         } else if (STRNCASECMP(iobuf, "Content-Type:") == 0) {
2069                                 content_type = xstrdup(skip_whitespace(iobuf + sizeof("Content-Type:")-1));
2070                         } else if (STRNCASECMP(iobuf, "Referer:") == 0) {
2071                                 referer = xstrdup(skip_whitespace(iobuf + sizeof("Referer:")-1));
2072                         } else if (STRNCASECMP(iobuf, "User-Agent:") == 0) {
2073                                 user_agent = xstrdup(skip_whitespace(iobuf + sizeof("User-Agent:")-1));
2074                         } else if (STRNCASECMP(iobuf, "Host:") == 0) {
2075                                 host = xstrdup(skip_whitespace(iobuf + sizeof("Host:")-1));
2076                         } else if (STRNCASECMP(iobuf, "Accept:") == 0) {
2077                                 http_accept = xstrdup(skip_whitespace(iobuf + sizeof("Accept:")-1));
2078                         } else if (STRNCASECMP(iobuf, "Accept-Language:") == 0) {
2079                                 http_accept_language = xstrdup(skip_whitespace(iobuf + sizeof("Accept-Language:")-1));
2080                         }
2081 #endif
2082 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
2083                         if (STRNCASECMP(iobuf, "Authorization:") == 0) {
2084                                 /* We only allow Basic credentials.
2085                                  * It shows up as "Authorization: Basic <user>:<passwd>" where
2086                                  * "<user>:<passwd>" is base64 encoded.
2087                                  */
2088                                 tptr = skip_whitespace(iobuf + sizeof("Authorization:")-1);
2089                                 if (STRNCASECMP(tptr, "Basic") != 0)
2090                                         continue;
2091                                 tptr += sizeof("Basic")-1;
2092                                 /* decodeBase64() skips whitespace itself */
2093                                 decodeBase64(tptr);
2094                                 authorized = check_user_passwd(urlcopy, tptr);
2095                         }
2096 #endif
2097 #if ENABLE_FEATURE_HTTPD_RANGES
2098                         if (STRNCASECMP(iobuf, "Range:") == 0) {
2099                                 /* We know only bytes=NNN-[MMM] */
2100                                 char *s = skip_whitespace(iobuf + sizeof("Range:")-1);
2101                                 if (strncmp(s, "bytes=", 6) == 0) {
2102                                         s += sizeof("bytes=")-1;
2103                                         range_start = BB_STRTOOFF(s, &s, 10);
2104                                         if (s[0] != '-' || range_start < 0) {
2105                                                 range_start = 0;
2106                                         } else if (s[1]) {
2107                                                 range_end = BB_STRTOOFF(s+1, NULL, 10);
2108                                                 if (errno || range_end < range_start)
2109                                                         range_start = 0;
2110                                         }
2111                                 }
2112                         }
2113 #endif
2114 #if ENABLE_FEATURE_HTTPD_GZIP
2115                         if (STRNCASECMP(iobuf, "Accept-Encoding:") == 0) {
2116                                 /* Note: we do not support "gzip;q=0"
2117                                  * method of _disabling_ gzip
2118                                  * delivery. No one uses that, though */
2119                                 const char *s = strstr(iobuf, "gzip");
2120                                 if (s) {
2121                                         // want more thorough checks?
2122                                         //if (s[-1] == ' '
2123                                         // || s[-1] == ','
2124                                         // || s[-1] == ':'
2125                                         //) {
2126                                                 content_gzip = 1;
2127                                         //}
2128                                 }
2129                         }
2130 #endif
2131                 } /* while extra header reading */
2132         }
2133
2134         /* We are done reading headers, disable peer timeout */
2135         alarm(0);
2136
2137         if (strcmp(bb_basename(urlcopy), HTTPD_CONF) == 0 || !ip_allowed) {
2138                 /* protect listing [/path]/httpd.conf or IP deny */
2139                 send_headers_and_exit(HTTP_FORBIDDEN);
2140         }
2141
2142 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
2143         /* Case: no "Authorization:" was seen, but page does require passwd.
2144          * Check that with dummy user:pass */
2145         if (authorized < 0)
2146                 authorized = check_user_passwd(urlcopy, ":");
2147         if (!authorized)
2148                 send_headers_and_exit(HTTP_UNAUTHORIZED);
2149 #endif
2150
2151         if (found_moved_temporarily) {
2152                 send_headers_and_exit(HTTP_MOVED_TEMPORARILY);
2153         }
2154
2155 #if ENABLE_FEATURE_HTTPD_PROXY
2156         if (proxy_entry != NULL) {
2157                 int proxy_fd;
2158                 len_and_sockaddr *lsa;
2159
2160                 proxy_fd = socket(AF_INET, SOCK_STREAM, 0);
2161                 if (proxy_fd < 0)
2162                         send_headers_and_exit(HTTP_INTERNAL_SERVER_ERROR);
2163                 lsa = host2sockaddr(proxy_entry->host_port, 80);
2164                 if (lsa == NULL)
2165                         send_headers_and_exit(HTTP_INTERNAL_SERVER_ERROR);
2166                 if (connect(proxy_fd, &lsa->u.sa, lsa->len) < 0)
2167                         send_headers_and_exit(HTTP_INTERNAL_SERVER_ERROR);
2168                 fdprintf(proxy_fd, "%s %s%s%s%s HTTP/%c.%c\r\n",
2169                                 prequest, /* GET or POST */
2170                                 proxy_entry->url_to, /* url part 1 */
2171                                 urlcopy + strlen(proxy_entry->url_from), /* url part 2 */
2172                                 (g_query ? "?" : ""), /* "?" (maybe) */
2173                                 (g_query ? g_query : ""), /* query string (maybe) */
2174                                 http_major_version, http_minor_version);
2175                 header_ptr[0] = '\r';
2176                 header_ptr[1] = '\n';
2177                 header_ptr += 2;
2178                 write(proxy_fd, header_buf, header_ptr - header_buf);
2179                 free(header_buf); /* on the order of 8k, free it */
2180                 cgi_io_loop_and_exit(proxy_fd, proxy_fd, length);
2181         }
2182 #endif
2183
2184         tptr = urlcopy + 1;      /* skip first '/' */
2185
2186 #if ENABLE_FEATURE_HTTPD_CGI
2187         if (strncmp(tptr, "cgi-bin/", 8) == 0) {
2188                 if (tptr[8] == '\0') {
2189                         /* protect listing "cgi-bin/" */
2190                         send_headers_and_exit(HTTP_FORBIDDEN);
2191                 }
2192                 send_cgi_and_exit(urlcopy, prequest, length, cookie, content_type);
2193         }
2194 #endif
2195
2196         if (urlp[-1] == '/')
2197                 strcpy(urlp, index_page);
2198         if (stat(tptr, &sb) == 0) {
2199 #if ENABLE_FEATURE_HTTPD_CONFIG_WITH_SCRIPT_INTERPR
2200                 char *suffix = strrchr(tptr, '.');
2201                 if (suffix) {
2202                         Htaccess *cur;
2203                         for (cur = script_i; cur; cur = cur->next) {
2204                                 if (strcmp(cur->before_colon + 1, suffix) == 0) {
2205                                         send_cgi_and_exit(urlcopy, prequest, length, cookie, content_type);
2206                                 }
2207                         }
2208                 }
2209 #endif
2210                 file_size = sb.st_size;
2211                 last_mod = sb.st_mtime;
2212         }
2213 #if ENABLE_FEATURE_HTTPD_CGI
2214         else if (urlp[-1] == '/') {
2215                 /* It's a dir URL and there is no index.html
2216                  * Try cgi-bin/index.cgi */
2217                 if (access("/cgi-bin/index.cgi"+1, X_OK) == 0) {
2218                         urlp[0] = '\0';
2219                         g_query = urlcopy;
2220                         send_cgi_and_exit("/cgi-bin/index.cgi", prequest, length, cookie, content_type);
2221                 }
2222         }
2223         /* else fall through to send_file, it errors out if open fails: */
2224
2225         if (prequest != request_GET && prequest != request_HEAD) {
2226                 /* POST for files does not make sense */
2227                 send_headers_and_exit(HTTP_NOT_IMPLEMENTED);
2228         }
2229         send_file_and_exit(tptr,
2230                 (prequest != request_HEAD ? SEND_HEADERS_AND_BODY : SEND_HEADERS)
2231         );
2232 #else
2233         send_file_and_exit(tptr, SEND_HEADERS_AND_BODY);
2234 #endif
2235 }
2236
2237 /*
2238  * The main http server function.
2239  * Given a socket, listen for new connections and farm out
2240  * the processing as a [v]forked process.
2241  * Never returns.
2242  */
2243 #if BB_MMU
2244 static void mini_httpd(int server_socket) NORETURN;
2245 static void mini_httpd(int server_socket)
2246 {
2247         /* NB: it's best to not use xfuncs in this loop before fork().
2248          * Otherwise server may die on transient errors (temporary
2249          * out-of-memory condition, etc), which is Bad(tm).
2250          * Try to do any dangerous calls after fork.
2251          */
2252         while (1) {
2253                 int n;
2254                 len_and_sockaddr fromAddr;
2255
2256                 /* Wait for connections... */
2257                 fromAddr.len = LSA_SIZEOF_SA;
2258                 n = accept(server_socket, &fromAddr.u.sa, &fromAddr.len);
2259                 if (n < 0)
2260                         continue;
2261
2262                 /* set the KEEPALIVE option to cull dead connections */
2263                 setsockopt(n, SOL_SOCKET, SO_KEEPALIVE, &const_int_1, sizeof(const_int_1));
2264
2265                 if (fork() == 0) {
2266                         /* child */
2267                         /* Do not reload config on HUP */
2268                         signal(SIGHUP, SIG_IGN);
2269                         close(server_socket);
2270                         xmove_fd(n, 0);
2271                         xdup2(0, 1);
2272
2273                         handle_incoming_and_exit(&fromAddr);
2274                 }
2275                 /* parent, or fork failed */
2276                 close(n);
2277         } /* while (1) */
2278         /* never reached */
2279 }
2280 #else
2281 static void mini_httpd_nommu(int server_socket, int argc, char **argv) NORETURN;
2282 static void mini_httpd_nommu(int server_socket, int argc, char **argv)
2283 {
2284         char *argv_copy[argc + 2];
2285
2286         argv_copy[0] = argv[0];
2287         argv_copy[1] = (char*)"-i";
2288         memcpy(&argv_copy[2], &argv[1], argc * sizeof(argv[0]));
2289
2290         /* NB: it's best to not use xfuncs in this loop before vfork().
2291          * Otherwise server may die on transient errors (temporary
2292          * out-of-memory condition, etc), which is Bad(tm).
2293          * Try to do any dangerous calls after fork.
2294          */
2295         while (1) {
2296                 int n;
2297                 len_and_sockaddr fromAddr;
2298
2299                 /* Wait for connections... */
2300                 fromAddr.len = LSA_SIZEOF_SA;
2301                 n = accept(server_socket, &fromAddr.u.sa, &fromAddr.len);
2302                 if (n < 0)
2303                         continue;
2304
2305                 /* set the KEEPALIVE option to cull dead connections */
2306                 setsockopt(n, SOL_SOCKET, SO_KEEPALIVE, &const_int_1, sizeof(const_int_1));
2307
2308                 if (vfork() == 0) {
2309                         /* child */
2310                         /* Do not reload config on HUP */
2311                         signal(SIGHUP, SIG_IGN);
2312                         close(server_socket);
2313                         xmove_fd(n, 0);
2314                         xdup2(0, 1);
2315
2316                         /* Run a copy of ourself in inetd mode */
2317                         re_exec(argv_copy);
2318                 }
2319                 /* parent, or vfork failed */
2320                 close(n);
2321         } /* while (1) */
2322         /* never reached */
2323 }
2324 #endif
2325
2326 /*
2327  * Process a HTTP connection on stdin/out.
2328  * Never returns.
2329  */
2330 static void mini_httpd_inetd(void) NORETURN;
2331 static void mini_httpd_inetd(void)
2332 {
2333         len_and_sockaddr fromAddr;
2334
2335         memset(&fromAddr, 0, sizeof(fromAddr));
2336         fromAddr.len = LSA_SIZEOF_SA;
2337         /* NB: can fail if user runs it by hand and types in http cmds */
2338         getpeername(0, &fromAddr.u.sa, &fromAddr.len);
2339         handle_incoming_and_exit(&fromAddr);
2340 }
2341
2342 static void sighup_handler(int sig UNUSED_PARAM)
2343 {
2344         parse_conf(DEFAULT_PATH_HTTPD_CONF, SIGNALED_PARSE);
2345 }
2346
2347 enum {
2348         c_opt_config_file = 0,
2349         d_opt_decode_url,
2350         h_opt_home_httpd,
2351         IF_FEATURE_HTTPD_ENCODE_URL_STR(e_opt_encode_url,)
2352         IF_FEATURE_HTTPD_BASIC_AUTH(    r_opt_realm     ,)
2353         IF_FEATURE_HTTPD_AUTH_MD5(      m_opt_md5       ,)
2354         IF_FEATURE_HTTPD_SETUID(        u_opt_setuid    ,)
2355         p_opt_port      ,
2356         p_opt_inetd     ,
2357         p_opt_foreground,
2358         p_opt_verbose   ,
2359         OPT_CONFIG_FILE = 1 << c_opt_config_file,
2360         OPT_DECODE_URL  = 1 << d_opt_decode_url,
2361         OPT_HOME_HTTPD  = 1 << h_opt_home_httpd,
2362         OPT_ENCODE_URL  = IF_FEATURE_HTTPD_ENCODE_URL_STR((1 << e_opt_encode_url)) + 0,
2363         OPT_REALM       = IF_FEATURE_HTTPD_BASIC_AUTH(    (1 << r_opt_realm     )) + 0,
2364         OPT_MD5         = IF_FEATURE_HTTPD_AUTH_MD5(      (1 << m_opt_md5       )) + 0,
2365         OPT_SETUID      = IF_FEATURE_HTTPD_SETUID(        (1 << u_opt_setuid    )) + 0,
2366         OPT_PORT        = 1 << p_opt_port,
2367         OPT_INETD       = 1 << p_opt_inetd,
2368         OPT_FOREGROUND  = 1 << p_opt_foreground,
2369         OPT_VERBOSE     = 1 << p_opt_verbose,
2370 };
2371
2372
2373 int httpd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
2374 int httpd_main(int argc UNUSED_PARAM, char **argv)
2375 {
2376         int server_socket = server_socket; /* for gcc */
2377         unsigned opt;
2378         char *url_for_decode;
2379         IF_FEATURE_HTTPD_ENCODE_URL_STR(const char *url_for_encode;)
2380         IF_FEATURE_HTTPD_SETUID(const char *s_ugid = NULL;)
2381         IF_FEATURE_HTTPD_SETUID(struct bb_uidgid_t ugid;)
2382         IF_FEATURE_HTTPD_AUTH_MD5(const char *pass;)
2383
2384         INIT_G();
2385
2386 #if ENABLE_LOCALE_SUPPORT
2387         /* Undo busybox.c: we want to speak English in http (dates etc) */
2388         setlocale(LC_TIME, "C");
2389 #endif
2390
2391         home_httpd = xrealloc_getcwd_or_warn(NULL);
2392         /* -v counts, -i implies -f */
2393         opt_complementary = "vv:if";
2394         /* We do not "absolutize" path given by -h (home) opt.
2395          * If user gives relative path in -h,
2396          * $SCRIPT_FILENAME will not be set. */
2397         opt = getopt32(argv, "c:d:h:"
2398                         IF_FEATURE_HTTPD_ENCODE_URL_STR("e:")
2399                         IF_FEATURE_HTTPD_BASIC_AUTH("r:")
2400                         IF_FEATURE_HTTPD_AUTH_MD5("m:")
2401                         IF_FEATURE_HTTPD_SETUID("u:")
2402                         "p:ifv",
2403                         &opt_c_configFile, &url_for_decode, &home_httpd
2404                         IF_FEATURE_HTTPD_ENCODE_URL_STR(, &url_for_encode)
2405                         IF_FEATURE_HTTPD_BASIC_AUTH(, &g_realm)
2406                         IF_FEATURE_HTTPD_AUTH_MD5(, &pass)
2407                         IF_FEATURE_HTTPD_SETUID(, &s_ugid)
2408                         , &bind_addr_or_port
2409                         , &verbose
2410                 );
2411         if (opt & OPT_DECODE_URL) {
2412                 fputs(decodeString(url_for_decode, 1), stdout);
2413                 return 0;
2414         }
2415 #if ENABLE_FEATURE_HTTPD_ENCODE_URL_STR
2416         if (opt & OPT_ENCODE_URL) {
2417                 fputs(encodeString(url_for_encode), stdout);
2418                 return 0;
2419         }
2420 #endif
2421 #if ENABLE_FEATURE_HTTPD_AUTH_MD5
2422         if (opt & OPT_MD5) {
2423                 char salt[sizeof("$1$XXXXXXXX")];
2424                 salt[0] = '$';
2425                 salt[1] = '1';
2426                 salt[2] = '$';
2427                 crypt_make_salt(salt + 3, 4);
2428                 puts(pw_encrypt(pass, salt, 1));
2429                 return 0;
2430         }
2431 #endif
2432 #if ENABLE_FEATURE_HTTPD_SETUID
2433         if (opt & OPT_SETUID) {
2434                 xget_uidgid(&ugid, s_ugid);
2435         }
2436 #endif
2437
2438 #if !BB_MMU
2439         if (!(opt & OPT_FOREGROUND)) {
2440                 bb_daemonize_or_rexec(0, argv); /* don't change current directory */
2441         }
2442 #endif
2443
2444         xchdir(home_httpd);
2445         if (!(opt & OPT_INETD)) {
2446                 signal(SIGCHLD, SIG_IGN);
2447                 server_socket = openServer();
2448 #if ENABLE_FEATURE_HTTPD_SETUID
2449                 /* drop privileges */
2450                 if (opt & OPT_SETUID) {
2451                         if (ugid.gid != (gid_t)-1) {
2452                                 if (setgroups(1, &ugid.gid) == -1)
2453                                         bb_perror_msg_and_die("setgroups");
2454                                 xsetgid(ugid.gid);
2455                         }
2456                         xsetuid(ugid.uid);
2457                 }
2458 #endif
2459         }
2460
2461 #if 0
2462         /* User can do it himself: 'env - PATH="$PATH" httpd'
2463          * We don't do it because we don't want to screw users
2464          * which want to do
2465          * 'env - VAR1=val1 VAR2=val2 httpd'
2466          * and have VAR1 and VAR2 values visible in their CGIs.
2467          * Besides, it is also smaller. */
2468         {
2469                 char *p = getenv("PATH");
2470                 /* env strings themself are not freed, no need to xstrdup(p): */
2471                 clearenv();
2472                 if (p)
2473                         putenv(p - 5);
2474 //              if (!(opt & OPT_INETD))
2475 //                      setenv_long("SERVER_PORT", ???);
2476         }
2477 #endif
2478
2479         parse_conf(DEFAULT_PATH_HTTPD_CONF, FIRST_PARSE);
2480         if (!(opt & OPT_INETD))
2481                 signal(SIGHUP, sighup_handler);
2482
2483         xfunc_error_retval = 0;
2484         if (opt & OPT_INETD)
2485                 mini_httpd_inetd();
2486 #if BB_MMU
2487         if (!(opt & OPT_FOREGROUND))
2488                 bb_daemonize(0); /* don't change current directory */
2489         mini_httpd(server_socket); /* never returns */
2490 #else
2491         mini_httpd_nommu(server_socket, argc, argv); /* never returns */
2492 #endif
2493         /* return 0; */
2494 }