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  * /adm:root:*       # or user root, pwd from /etc/passwd on urls starting with /adm/
  58  * /wiki:*:*         # or any user from /etc/passwd with according pwd on urls starting with /wiki/
  59  * .au:audio/basic   # additional mime type for audio.au files
  60  * *.php:/path/php   # run xxx.php through an interpreter
  61  *
  62  * A/D may be as a/d or allow/deny - only first char matters.
  63  * Deny/Allow IP logic:
  64  *  - Default is to allow all (Allow all (A:*) is a no-op).
  65  *  - Deny rules take precedence over allow rules.
  66  *  - "Deny all" rule (D:*) is applied last.
  67  *
  68  * Example:
  69  *   1. Allow only specified addresses
  70  *     A:172.20          # Allow any address that begins with 172.20.
  71  *     A:10.10.          # Allow any address that begins with 10.10.
  72  *     A:127.0.0.1       # Allow local loopback connections
  73  *     D:*               # Deny from other IP connections
  74  *
  75  *   2. Only deny specified addresses
  76  *     D:1.2.3.        # deny from 1.2.3.0 - 1.2.3.255
  77  *     D:2.3.4.        # deny from 2.3.4.0 - 2.3.4.255
  78  *     A:*             # (optional line added for clarity)
  79  *
  80  * If a sub directory contains config file, it is parsed and merged with
  81  * any existing settings as if it was appended to the original configuration.
  82  *
  83  * subdir paths are relative to the containing subdir and thus cannot
  84  * affect the parent rules.
  85  *
  86  * Note that since the sub dir is parsed in the forked thread servicing the
  87  * subdir http request, any merge is discarded when the process exits.  As a
  88  * result, the subdir settings only have a lifetime of a single request.
  89  *
  90  * Custom error pages can contain an absolute path or be relative to
  91  * 'home_httpd'. Error pages are to be static files (no CGI or script). Error
  92  * page can only be defined in the root configuration file and are not taken
  93  * into account in local (directories) config files.
  94  *
  95  * If -c is not set, an attempt will be made to open the default
  96  * root configuration file.  If -c is set and the file is not found, the
  97  * server exits with an error.
  98  *
  99  */
 100  /* TODO: use TCP_CORK, parse_config() */
 101 //config:config HTTPD
 102 //config:       bool "httpd (32 kb)"
 103 //config:       default y
 104 //config:       help
 105 //config:       HTTP server.
 106 //config:
 107 //config:config FEATURE_HTTPD_RANGES
 108 //config:       bool "Support 'Ranges:' header"
 109 //config:       default y
 110 //config:       depends on HTTPD
 111 //config:       help
 112 //config:       Makes httpd emit "Accept-Ranges: bytes" header and understand
 113 //config:       "Range: bytes=NNN-[MMM]" header. Allows for resuming interrupted
 114 //config:       downloads, seeking in multimedia players etc.
 115 //config:
 116 //config:config FEATURE_HTTPD_SETUID
 117 //config:       bool "Enable -u <user> option"
 118 //config:       default y
 119 //config:       depends on HTTPD
 120 //config:       help
 121 //config:       This option allows the server to run as a specific user
 122 //config:       rather than defaulting to the user that starts the server.
 123 //config:       Use of this option requires special privileges to change to a
 124 //config:       different user.
 125 //config:
 126 //config:config FEATURE_HTTPD_BASIC_AUTH
 127 //config:       bool "Enable HTTP authentication"
 128 //config:       default y
 129 //config:       depends on HTTPD
 130 //config:       help
 131 //config:       Utilizes password settings from /etc/httpd.conf for basic
 132 //config:       authentication on a per url basis.
 133 //config:       Example for httpd.conf file:
 134 //config:       /adm:toor:PaSsWd
 135 //config:
 136 //config:config FEATURE_HTTPD_AUTH_MD5
 137 //config:       bool "Support MD5-encrypted passwords in HTTP authentication"
 138 //config:       default y
 139 //config:       depends on FEATURE_HTTPD_BASIC_AUTH
 140 //config:       help
 141 //config:       Enables encrypted passwords, and wildcard user/passwords
 142 //config:       in httpd.conf file.
 143 //config:       User '*' means 'any system user name is ok',
 144 //config:       password of '*' means 'use system password for this user'
 145 //config:       Examples:
 146 //config:       /adm:toor:$1$P/eKnWXS$aI1aPGxT.dJD5SzqAKWrF0
 147 //config:       /adm:root:*
 148 //config:       /wiki:*:*
 149 //config:
 150 //config:config FEATURE_HTTPD_CGI
 151 //config:       bool "Support Common Gateway Interface (CGI)"
 152 //config:       default y
 153 //config:       depends on HTTPD
 154 //config:       help
 155 //config:       This option allows scripts and executables to be invoked
 156 //config:       when specific URLs are requested.
 157 //config:
 158 //config:config FEATURE_HTTPD_CONFIG_WITH_SCRIPT_INTERPR
 159 //config:       bool "Support running scripts through an interpreter"
 160 //config:       default y
 161 //config:       depends on FEATURE_HTTPD_CGI
 162 //config:       help
 163 //config:       This option enables support for running scripts through an
 164 //config:       interpreter. Turn this on if you want PHP scripts to work
 165 //config:       properly. You need to supply an additional line in your
 166 //config:       httpd.conf file:
 167 //config:       *.php:/path/to/your/php
 168 //config:
 169 //config:config FEATURE_HTTPD_SET_REMOTE_PORT_TO_ENV
 170 //config:       bool "Set REMOTE_PORT environment variable for CGI"
 171 //config:       default y
 172 //config:       depends on FEATURE_HTTPD_CGI
 173 //config:       help
 174 //config:       Use of this option can assist scripts in generating
 175 //config:       references that contain a unique port number.
 176 //config:
 177 //config:config FEATURE_HTTPD_ENCODE_URL_STR
 178 //config:       bool "Enable -e option (useful for CGIs written as shell scripts)"
 179 //config:       default y
 180 //config:       depends on HTTPD
 181 //config:       help
 182 //config:       This option allows html encoding of arbitrary strings for display
 183 //config:       by the browser. Output goes to stdout.
 184 //config:       For example, httpd -e "<Hello World>" produces
 185 //config:       "&#60Hello&#32World&#62".
 186 //config:
 187 //config:config FEATURE_HTTPD_ERROR_PAGES
 188 //config:       bool "Support custom error pages"
 189 //config:       default y
 190 //config:       depends on HTTPD
 191 //config:       help
 192 //config:       This option allows you to define custom error pages in
 193 //config:       the configuration file instead of the default HTTP status
 194 //config:       error pages. For instance, if you add the line:
 195 //config:               E404:/path/e404.html
 196 //config:       in the config file, the server will respond the specified
 197 //config:       '/path/e404.html' file instead of the terse '404 NOT FOUND'
 198 //config:       message.
 199 //config:
 200 //config:config FEATURE_HTTPD_PROXY
 201 //config:       bool "Support reverse proxy"
 202 //config:       default y
 203 //config:       depends on HTTPD
 204 //config:       help
 205 //config:       This option allows you to define URLs that will be forwarded
 206 //config:       to another HTTP server. To setup add the following line to the
 207 //config:       configuration file
 208 //config:               P:/url/:http://hostname[:port]/new/path/
 209 //config:       Then a request to /url/myfile will be forwarded to
 210 //config:       http://hostname[:port]/new/path/myfile.
 211 //config:
 212 //config:config FEATURE_HTTPD_GZIP
 213 //config:       bool "Support GZIP content encoding"
 214 //config:       default y
 215 //config:       depends on HTTPD
 216 //config:       help
 217 //config:       Makes httpd send files using GZIP content encoding if the
 218 //config:       client supports it and a pre-compressed <file>.gz exists.
 219
 220 //applet:IF_HTTPD(APPLET(httpd, BB_DIR_USR_SBIN, BB_SUID_DROP))
 221
 222 //kbuild:lib-$(CONFIG_HTTPD) += httpd.o
 223
 224 //usage:#define httpd_trivial_usage
 225 //usage:       "[-ifv[v]]"
 226 //usage:       " [-c CONFFILE]"
 227 //usage:       " [-p [IP:]PORT]"
 228 //usage:        IF_FEATURE_HTTPD_SETUID(" [-u USER[:GRP]]")
 229 //usage:        IF_FEATURE_HTTPD_BASIC_AUTH(" [-r REALM]")
 230 //usage:       " [-h HOME]\n"
 231 //usage:       "or httpd -d/-e" IF_FEATURE_HTTPD_AUTH_MD5("/-m") " STRING"
 232 //usage:#define httpd_full_usage "\n\n"
 233 //usage:       "Listen for incoming HTTP requests\n"
 234 //usage:     "\n        -i              Inetd mode"
 235 //usage:     "\n        -f              Don't daemonize"
 236 //usage:     "\n        -v[v]           Verbose"
 237 //usage:     "\n        -p [IP:]PORT    Bind to IP:PORT (default *:80)"
 238 //usage:        IF_FEATURE_HTTPD_SETUID(
 239 //usage:     "\n        -u USER[:GRP]   Set uid/gid after binding to port")
 240 //usage:        IF_FEATURE_HTTPD_BASIC_AUTH(
 241 //usage:     "\n        -r REALM        Authentication Realm for Basic Authentication")
 242 //usage:     "\n        -h HOME         Home directory (default .)"
 243 //usage:     "\n        -c FILE         Configuration file (default {/etc,HOME}/httpd.conf)"
 244 //usage:        IF_FEATURE_HTTPD_AUTH_MD5(
 245 //usage:     "\n        -m STRING       MD5 crypt STRING")
 246 //usage:     "\n        -e STRING       HTML encode STRING"
 247 //usage:     "\n        -d STRING       URL decode STRING"
 248
 249 #include "libbb.h"
 250 #include "common_bufsiz.h"
 251 #if ENABLE_PAM
 252 /* PAM may include <locale.h>. We may need to undefine bbox's stub define: */
 253 # undef setlocale
 254 /* For some obscure reason, PAM is not in pam/xxx, but in security/xxx.
 255  * Apparently they like to confuse people. */
 256 # include <security/pam_appl.h>
 257 # include <security/pam_misc.h>
 258 #endif
 259 #if ENABLE_FEATURE_USE_SENDFILE
 260 # include <sys/sendfile.h>
 261 #endif
 262 /* amount of buffering in a pipe */
 263 #ifndef PIPE_BUF
 264 # define PIPE_BUF 4096
 265 #endif
 266
 267 #define DEBUG 0
 268
 269 #define IOBUF_SIZE 8192
 270 #if PIPE_BUF >= IOBUF_SIZE
 271 # error "PIPE_BUF >= IOBUF_SIZE"
 272 #endif
 273
 274 #define HEADER_READ_TIMEOUT 60
 275
 276 static const char DEFAULT_PATH_HTTPD_CONF[] ALIGN1 = "/etc";
 277 static const char HTTPD_CONF[] ALIGN1 = "httpd.conf";
 278 static const char HTTP_200[] ALIGN1 = "HTTP/1.0 200 OK\r\n";
 279 static const char index_html[] ALIGN1 = "index.html";
 280
 281 typedef struct has_next_ptr {
 282         struct has_next_ptr *next;
 283 } has_next_ptr;
 284
 285 /* Must have "next" as a first member */
 286 typedef struct Htaccess {
 287         struct Htaccess *next;
 288         char *after_colon;
 289         char before_colon[1];  /* really bigger, must be last */
 290 } Htaccess;
 291
 292 /* Must have "next" as a first member */
 293 typedef struct Htaccess_IP {
 294         struct Htaccess_IP *next;
 295         unsigned ip;
 296         unsigned mask;
 297         int allow_deny;
 298 } Htaccess_IP;
 299
 300 /* Must have "next" as a first member */
 301 typedef struct Htaccess_Proxy {
 302         struct Htaccess_Proxy *next;
 303         char *url_from;
 304         char *host_port;
 305         char *url_to;
 306 } Htaccess_Proxy;
 307
 308 enum {
 309         HTTP_OK = 200,
 310         HTTP_PARTIAL_CONTENT = 206,
 311         HTTP_MOVED_TEMPORARILY = 302,
 312         HTTP_BAD_REQUEST = 400,       /* malformed syntax */
 313         HTTP_UNAUTHORIZED = 401, /* authentication needed, respond with auth hdr */
 314         HTTP_NOT_FOUND = 404,
 315         HTTP_FORBIDDEN = 403,
 316         HTTP_REQUEST_TIMEOUT = 408,
 317         HTTP_NOT_IMPLEMENTED = 501,   /* used for unrecognized requests */
 318         HTTP_INTERNAL_SERVER_ERROR = 500,
 319         HTTP_CONTINUE = 100,
 320 #if 0   /* future use */
 321         HTTP_SWITCHING_PROTOCOLS = 101,
 322         HTTP_CREATED = 201,
 323         HTTP_ACCEPTED = 202,
 324         HTTP_NON_AUTHORITATIVE_INFO = 203,
 325         HTTP_NO_CONTENT = 204,
 326         HTTP_MULTIPLE_CHOICES = 300,
 327         HTTP_MOVED_PERMANENTLY = 301,
 328         HTTP_NOT_MODIFIED = 304,
 329         HTTP_PAYMENT_REQUIRED = 402,
 330         HTTP_BAD_GATEWAY = 502,
 331         HTTP_SERVICE_UNAVAILABLE = 503, /* overload, maintenance */
 332 #endif
 333 };
 334
 335 static const uint16_t http_response_type[] ALIGN2 = {
 336         HTTP_OK,
 337 #if ENABLE_FEATURE_HTTPD_RANGES
 338         HTTP_PARTIAL_CONTENT,
 339 #endif
 340         HTTP_MOVED_TEMPORARILY,
 341         HTTP_REQUEST_TIMEOUT,
 342         HTTP_NOT_IMPLEMENTED,
 343 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
 344         HTTP_UNAUTHORIZED,
 345 #endif
 346         HTTP_NOT_FOUND,
 347         HTTP_BAD_REQUEST,
 348         HTTP_FORBIDDEN,
 349         HTTP_INTERNAL_SERVER_ERROR,
 350 #if 0   /* not implemented */
 351         HTTP_CREATED,
 352         HTTP_ACCEPTED,
 353         HTTP_NO_CONTENT,
 354         HTTP_MULTIPLE_CHOICES,
 355         HTTP_MOVED_PERMANENTLY,
 356         HTTP_NOT_MODIFIED,
 357         HTTP_BAD_GATEWAY,
 358         HTTP_SERVICE_UNAVAILABLE,
 359 #endif
 360 };
 361
 362 static const struct {
 363         const char *name;
 364         const char *info;
 365 } http_response[ARRAY_SIZE(http_response_type)] = {
 366         { "OK", NULL },
 367 #if ENABLE_FEATURE_HTTPD_RANGES
 368         { "Partial Content", NULL },
 369 #endif
 370         { "Found", NULL },
 371         { "Request Timeout", "No request appeared within 60 seconds" },
 372         { "Not Implemented", "The requested method is not recognized" },
 373 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
 374         { "Unauthorized", "" },
 375 #endif
 376         { "Not Found", "The requested URL was not found" },
 377         { "Bad Request", "Unsupported method" },
 378         { "Forbidden", ""  },
 379         { "Internal Server Error", "Internal Server Error" },
 380 #if 0   /* not implemented */
 381         { "Created" },
 382         { "Accepted" },
 383         { "No Content" },
 384         { "Multiple Choices" },
 385         { "Moved Permanently" },
 386         { "Not Modified" },
 387         { "Bad Gateway", "" },
 388         { "Service Unavailable", "" },
 389 #endif
 390 };
 391
 392 struct globals {
 393         int verbose;            /* must be int (used by getopt32) */
 394         smallint flg_deny_all;
 395 #if ENABLE_FEATURE_HTTPD_GZIP
 396         /* client can handle gzip / we are going to send gzip */
 397         smallint content_gzip;
 398 #endif
 399         unsigned rmt_ip;        /* used for IP-based allow/deny rules */
 400         time_t last_mod;
 401         char *rmt_ip_str;       /* for $REMOTE_ADDR and $REMOTE_PORT */
 402         const char *bind_addr_or_port;
 403
 404         const char *g_query;
 405         const char *opt_c_configFile;
 406         const char *home_httpd;
 407         const char *index_page;
 408
 409         const char *found_mime_type;
 410         const char *found_moved_temporarily;
 411         Htaccess_IP *ip_a_d;    /* config allow/deny lines */
 412
 413         IF_FEATURE_HTTPD_BASIC_AUTH(const char *g_realm;)
 414         IF_FEATURE_HTTPD_BASIC_AUTH(char *remoteuser;)
 415         IF_FEATURE_HTTPD_CGI(char *referer;)
 416         IF_FEATURE_HTTPD_CGI(char *user_agent;)
 417         IF_FEATURE_HTTPD_CGI(char *host;)
 418         IF_FEATURE_HTTPD_CGI(char *http_accept;)
 419         IF_FEATURE_HTTPD_CGI(char *http_accept_language;)
 420
 421         off_t file_size;        /* -1 - unknown */
 422 #if ENABLE_FEATURE_HTTPD_RANGES
 423         off_t range_start;
 424         off_t range_end;
 425         off_t range_len;
 426 #endif
 427
 428 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
 429         Htaccess *g_auth;       /* config user:password lines */
 430 #endif
 431         Htaccess *mime_a;       /* config mime types */
 432 #if ENABLE_FEATURE_HTTPD_CONFIG_WITH_SCRIPT_INTERPR
 433         Htaccess *script_i;     /* config script interpreters */
 434 #endif
 435         char *iobuf;            /* [IOBUF_SIZE] */
 436 #define        hdr_buf bb_common_bufsiz1
 437 #define sizeof_hdr_buf COMMON_BUFSIZE
 438         char *hdr_ptr;
 439         int hdr_cnt;
 440 #if ENABLE_FEATURE_HTTPD_ERROR_PAGES
 441         const char *http_error_page[ARRAY_SIZE(http_response_type)];
 442 #endif
 443 #if ENABLE_FEATURE_HTTPD_PROXY
 444         Htaccess_Proxy *proxy;
 445 #endif
 446 };
 447 #define G (*ptr_to_globals)
 448 #define verbose           (G.verbose          )
 449 #define flg_deny_all      (G.flg_deny_all     )
 450 #if ENABLE_FEATURE_HTTPD_GZIP
 451 # define content_gzip     (G.content_gzip     )
 452 #else
 453 # define content_gzip     0
 454 #endif
 455 #define rmt_ip            (G.rmt_ip           )
 456 #define bind_addr_or_port (G.bind_addr_or_port)
 457 #define g_query           (G.g_query          )
 458 #define opt_c_configFile  (G.opt_c_configFile )
 459 #define home_httpd        (G.home_httpd       )
 460 #define index_page        (G.index_page       )
 461 #define found_mime_type   (G.found_mime_type  )
 462 #define found_moved_temporarily (G.found_moved_temporarily)
 463 #define last_mod          (G.last_mod         )
 464 #define ip_a_d            (G.ip_a_d           )
 465 #define g_realm           (G.g_realm          )
 466 #define remoteuser        (G.remoteuser       )
 467 #define file_size         (G.file_size        )
 468 #if ENABLE_FEATURE_HTTPD_RANGES
 469 #define range_start       (G.range_start      )
 470 #define range_end         (G.range_end        )
 471 #define range_len         (G.range_len        )
 472 #else
 473 enum {
 474         range_start = -1,
 475         range_end = MAXINT(off_t) - 1,
 476         range_len = MAXINT(off_t),
 477 };
 478 #endif
 479 #define rmt_ip_str        (G.rmt_ip_str       )
 480 #define g_auth            (G.g_auth           )
 481 #define mime_a            (G.mime_a           )
 482 #define script_i          (G.script_i         )
 483 #define iobuf             (G.iobuf            )
 484 #define hdr_ptr           (G.hdr_ptr          )
 485 #define hdr_cnt           (G.hdr_cnt          )
 486 #define http_error_page   (G.http_error_page  )
 487 #define proxy             (G.proxy            )
 488 #define INIT_G() do { \
 489         setup_common_bufsiz(); \
 490         SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
 491         IF_FEATURE_HTTPD_BASIC_AUTH(g_realm = "Web Server Authentication";) \
 492         IF_FEATURE_HTTPD_RANGES(range_start = -1;) \
 493         bind_addr_or_port = "80"; \
 494         index_page = index_html; \
 495         file_size = -1; \
 496 } while (0)
 497
 498
 499 #define STRNCASECMP(a, str) strncasecmp((a), (str), sizeof(str)-1)
 500
 501 /* Prototypes */
 502 enum {
 503         SEND_HEADERS     = (1 << 0),
 504         SEND_BODY        = (1 << 1),
 505         SEND_HEADERS_AND_BODY = SEND_HEADERS + SEND_BODY,
 506 };
 507 static void send_file_and_exit(const char *url, int what) NORETURN;
 508
 509 static void free_llist(has_next_ptr **pptr)
 510 {
 511         has_next_ptr *cur = *pptr;
 512         while (cur) {
 513                 has_next_ptr *t = cur;
 514                 cur = cur->next;
 515                 free(t);
 516         }
 517         *pptr = NULL;
 518 }
 519
 520 static ALWAYS_INLINE void free_Htaccess_list(Htaccess **pptr)
 521 {
 522         free_llist((has_next_ptr**)pptr);
 523 }
 524
 525 static ALWAYS_INLINE void free_Htaccess_IP_list(Htaccess_IP **pptr)
 526 {
 527         free_llist((has_next_ptr**)pptr);
 528 }
 529
 530 /* Returns presumed mask width in bits or < 0 on error.
 531  * Updates strp, stores IP at provided pointer */
 532 static int scan_ip(const char **strp, unsigned *ipp, unsigned char endc)
 533 {
 534         const char *p = *strp;
 535         int auto_mask = 8;
 536         unsigned ip = 0;
 537         int j;
 538
 539         if (*p == '/')
 540                 return -auto_mask;
 541
 542         for (j = 0; j < 4; j++) {
 543                 unsigned octet;
 544
 545                 if ((*p < '0' || *p > '9') && *p != '/' && *p)
 546                         return -auto_mask;
 547                 octet = 0;
 548                 while (*p >= '0' && *p <= '9') {
 549                         octet *= 10;
 550                         octet += *p - '0';
 551                         if (octet > 255)
 552                                 return -auto_mask;
 553                         p++;
 554                 }
 555                 if (*p == '.')
 556                         p++;
 557                 if (*p != '/' && *p)
 558                         auto_mask += 8;
 559                 ip = (ip << 8) | octet;
 560         }
 561         if (*p) {
 562                 if (*p != endc)
 563                         return -auto_mask;
 564                 p++;
 565                 if (*p == '\0')
 566                         return -auto_mask;
 567         }
 568         *ipp = ip;
 569         *strp = p;
 570         return auto_mask;
 571 }
 572
 573 /* Returns 0 on success. Stores IP and mask at provided pointers */
 574 static int scan_ip_mask(const char *str, unsigned *ipp, unsigned *maskp)
 575 {
 576         int i;
 577         unsigned mask;
 578         char *p;
 579
 580         i = scan_ip(&str, ipp, '/');
 581         if (i < 0)
 582                 return i;
 583
 584         if (*str) {
 585                 /* there is /xxx after dotted-IP address */
 586                 i = bb_strtou(str, &p, 10);
 587                 if (*p == '.') {
 588                         /* 'xxx' itself is dotted-IP mask, parse it */
 589                         /* (return 0 (success) only if it has N.N.N.N form) */
 590                         return scan_ip(&str, maskp, '\0') - 32;
 591                 }
 592                 if (*p)
 593                         return -1;
 594         }
 595
 596         if (i > 32)
 597                 return -1;
 598
 599         if (sizeof(unsigned) == 4 && i == 32) {
 600                 /* mask >>= 32 below may not work */
 601                 mask = 0;
 602         } else {
 603                 mask = 0xffffffff;
 604                 mask >>= i;
 605         }
 606         /* i == 0 -> *maskp = 0x00000000
 607          * i == 1 -> *maskp = 0x80000000
 608          * i == 4 -> *maskp = 0xf0000000
 609          * i == 31 -> *maskp = 0xfffffffe
 610          * i == 32 -> *maskp = 0xffffffff */
 611         *maskp = (uint32_t)(~mask);
 612         return 0;
 613 }
 614
 615 /*
 616  * Parse configuration file into in-memory linked list.
 617  *
 618  * Any previous IP rules are discarded.
 619  * If the flag argument is not SUBDIR_PARSE then all /path and mime rules
 620  * are also discarded.  That is, previous settings are retained if flag is
 621  * SUBDIR_PARSE.
 622  * Error pages are only parsed on the main config file.
 623  *
 624  * path   Path where to look for httpd.conf (without filename).
 625  * flag   Type of the parse request.
 626  */
 627 /* flag param: */
 628 enum {
 629         FIRST_PARSE    = 0, /* path will be "/etc" */
 630         SIGNALED_PARSE = 1, /* path will be "/etc" */
 631         SUBDIR_PARSE   = 2, /* path will be derived from URL */
 632 };
 633 static void parse_conf(const char *path, int flag)
 634 {
 635         /* internally used extra flag state */
 636         enum { TRY_CURDIR_PARSE = 3 };
 637
 638         FILE *f;
 639         const char *filename;
 640         char buf[160];
 641
 642         /* discard old rules */
 643         free_Htaccess_IP_list(&ip_a_d);
 644         flg_deny_all = 0;
 645         /* retain previous auth and mime config only for subdir parse */
 646         if (flag != SUBDIR_PARSE) {
 647                 free_Htaccess_list(&mime_a);
 648 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
 649                 free_Htaccess_list(&g_auth);
 650 #endif
 651 #if ENABLE_FEATURE_HTTPD_CONFIG_WITH_SCRIPT_INTERPR
 652                 free_Htaccess_list(&script_i);
 653 #endif
 654         }
 655
 656         filename = opt_c_configFile;
 657         if (flag == SUBDIR_PARSE || filename == NULL) {
 658                 filename = alloca(strlen(path) + sizeof(HTTPD_CONF) + 2);
 659                 sprintf((char *)filename, "%s/%s", path, HTTPD_CONF);
 660         }
 661
 662         while ((f = fopen_for_read(filename)) == NULL) {
 663                 if (flag >= SUBDIR_PARSE) { /* SUBDIR or TRY_CURDIR */
 664                         /* config file not found, no changes to config */
 665                         return;
 666                 }
 667                 if (flag == FIRST_PARSE) {
 668                         /* -c CONFFILE given, but CONFFILE doesn't exist? */
 669                         if (opt_c_configFile)
 670                                 bb_simple_perror_msg_and_die(opt_c_configFile);
 671                         /* else: no -c, thus we looked at /etc/httpd.conf,
 672                          * and it's not there. try ./httpd.conf: */
 673                 }
 674                 flag = TRY_CURDIR_PARSE;
 675                 filename = HTTPD_CONF;
 676         }
 677
 678 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
 679         /* in "/file:user:pass" lines, we prepend path in subdirs */
 680         if (flag != SUBDIR_PARSE)
 681                 path = "";
 682 #endif
 683         /* The lines can be:
 684          *
 685          * I:default_index_file
 686          * H:http_home
 687          * [AD]:IP[/mask]   # allow/deny, * for wildcard
 688          * Ennn:error.html  # error page for status nnn
 689          * P:/url:[http://]hostname[:port]/new/path # reverse proxy
 690          * .ext:mime/type   # mime type
 691          * *.php:/path/php  # run xxx.php through an interpreter
 692          * /file:user:pass  # username and password
 693          */
 694         while (fgets(buf, sizeof(buf), f) != NULL) {
 695                 unsigned strlen_buf;
 696                 unsigned char ch;
 697                 char *after_colon;
 698
 699                 { /* remove all whitespace, and # comments */
 700                         char *p, *p0;
 701
 702                         p0 = buf;
 703                         /* skip non-whitespace beginning. Often the whole line
 704                          * is non-whitespace. We want this case to work fast,
 705                          * without needless copying, therefore we don't merge
 706                          * this operation into next while loop. */
 707                         while ((ch = *p0) != '\0' && ch != '\n' && ch != '#'
 708                          && ch != ' ' && ch != '\t'
 709                         ) {
 710                                 p0++;
 711                         }
 712                         p = p0;
 713                         /* if we enter this loop, we have some whitespace.
 714                          * discard it */
 715                         while (ch != '\0' && ch != '\n' && ch != '#') {
 716                                 if (ch != ' ' && ch != '\t') {
 717                                         *p++ = ch;
 718                                 }
 719                                 ch = *++p0;
 720                         }
 721                         *p = '\0';
 722                         strlen_buf = p - buf;
 723                         if (strlen_buf == 0)
 724                                 continue; /* empty line */
 725                 }
 726
 727                 after_colon = strchr(buf, ':');
 728                 /* strange line? */
 729                 if (after_colon == NULL || *++after_colon == '\0')
 730                         goto config_error;
 731
 732                 ch = (buf[0] & ~0x20); /* toupper if it's a letter */
 733
 734                 if (ch == 'I') {
 735                         if (index_page != index_html)
 736                                 free((char*)index_page);
 737                         index_page = xstrdup(after_colon);
 738                         continue;
 739                 }
 740
 741                 /* do not allow jumping around using H in subdir's configs */
 742                 if (flag == FIRST_PARSE && ch == 'H') {
 743                         home_httpd = xstrdup(after_colon);
 744                         xchdir(home_httpd);
 745                         continue;
 746                 }
 747
 748                 if (ch == 'A' || ch == 'D') {
 749                         Htaccess_IP *pip;
 750
 751                         if (*after_colon == '*') {
 752                                 if (ch == 'D') {
 753                                         /* memorize "deny all" */
 754                                         flg_deny_all = 1;
 755                                 }
 756                                 /* skip assumed "A:*", it is a default anyway */
 757                                 continue;
 758                         }
 759                         /* store "allow/deny IP/mask" line */
 760                         pip = xzalloc(sizeof(*pip));
 761                         if (scan_ip_mask(after_colon, &pip->ip, &pip->mask)) {
 762                                 /* IP{/mask} syntax error detected, protect all */
 763                                 ch = 'D';
 764                                 pip->mask = 0;
 765                         }
 766                         pip->allow_deny = ch;
 767                         if (ch == 'D') {
 768                                 /* Deny:from_IP - prepend */
 769                                 pip->next = ip_a_d;
 770                                 ip_a_d = pip;
 771                         } else {
 772                                 /* A:from_IP - append (thus all D's precedes A's) */
 773                                 Htaccess_IP *prev_IP = ip_a_d;
 774                                 if (prev_IP == NULL) {
 775                                         ip_a_d = pip;
 776                                 } else {
 777                                         while (prev_IP->next)
 778                                                 prev_IP = prev_IP->next;
 779                                         prev_IP->next = pip;
 780                                 }
 781                         }
 782                         continue;
 783                 }
 784
 785 #if ENABLE_FEATURE_HTTPD_ERROR_PAGES
 786                 if (flag == FIRST_PARSE && ch == 'E') {
 787                         unsigned i;
 788                         int status = atoi(buf + 1); /* error status code */
 789
 790                         if (status < HTTP_CONTINUE) {
 791                                 goto config_error;
 792                         }
 793                         /* then error page; find matching status */
 794                         for (i = 0; i < ARRAY_SIZE(http_response_type); i++) {
 795                                 if (http_response_type[i] == status) {
 796                                         /* We chdir to home_httpd, thus no need to
 797                                          * concat_path_file(home_httpd, after_colon)
 798                                          * here */
 799                                         http_error_page[i] = xstrdup(after_colon);
 800                                         break;
 801                                 }
 802                         }
 803                         continue;
 804                 }
 805 #endif
 806
 807 #if ENABLE_FEATURE_HTTPD_PROXY
 808                 if (flag == FIRST_PARSE && ch == 'P') {
 809                         /* P:/url:[http://]hostname[:port]/new/path */
 810                         char *url_from, *host_port, *url_to;
 811                         Htaccess_Proxy *proxy_entry;
 812
 813                         url_from = after_colon;
 814                         host_port = strchr(after_colon, ':');
 815                         if (host_port == NULL) {
 816                                 goto config_error;
 817                         }
 818                         *host_port++ = '\0';
 819                         if (is_prefixed_with(host_port, "http://"))
 820                                 host_port += 7;
 821                         if (*host_port == '\0') {
 822                                 goto config_error;
 823                         }
 824                         url_to = strchr(host_port, '/');
 825                         if (url_to == NULL) {
 826                                 goto config_error;
 827                         }
 828                         *url_to = '\0';
 829                         proxy_entry = xzalloc(sizeof(*proxy_entry));
 830                         proxy_entry->url_from = xstrdup(url_from);
 831                         proxy_entry->host_port = xstrdup(host_port);
 832                         *url_to = '/';
 833                         proxy_entry->url_to = xstrdup(url_to);
 834                         proxy_entry->next = proxy;
 835                         proxy = proxy_entry;
 836                         continue;
 837                 }
 838 #endif
 839                 /* the rest of directives are non-alphabetic,
 840                  * must avoid using "toupper'ed" ch */
 841                 ch = buf[0];
 842
 843                 if (ch == '.' /* ".ext:mime/type" */
 844 #if ENABLE_FEATURE_HTTPD_CONFIG_WITH_SCRIPT_INTERPR
 845                  || (ch == '*' && buf[1] == '.') /* "*.php:/path/php" */
 846 #endif
 847                 ) {
 848                         char *p;
 849                         Htaccess *cur;
 850
 851                         cur = xzalloc(sizeof(*cur) /* includes space for NUL */ + strlen_buf);
 852                         strcpy(cur->before_colon, buf);
 853                         p = cur->before_colon + (after_colon - buf);
 854                         p[-1] = '\0';
 855                         cur->after_colon = p;
 856                         if (ch == '.') {
 857                                 /* .mime line: prepend to mime_a list */
 858                                 cur->next = mime_a;
 859                                 mime_a = cur;
 860                         }
 861 #if ENABLE_FEATURE_HTTPD_CONFIG_WITH_SCRIPT_INTERPR
 862                         else {
 863                                 /* script interpreter line: prepend to script_i list */
 864                                 cur->next = script_i;
 865                                 script_i = cur;
 866                         }
 867 #endif
 868                         continue;
 869                 }
 870
 871 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
 872                 if (ch == '/') { /* "/file:user:pass" */
 873                         char *p;
 874                         Htaccess *cur;
 875                         unsigned file_len;
 876
 877                         /* note: path is "" unless we are in SUBDIR parse,
 878                          * otherwise it does NOT start with "/" */
 879                         cur = xzalloc(sizeof(*cur) /* includes space for NUL */
 880                                 + 1 + strlen(path)
 881                                 + strlen_buf
 882                                 );
 883                         /* form "/path/file" */
 884                         sprintf(cur->before_colon, "/%s%.*s",
 885                                 path,
 886                                 (int) (after_colon - buf - 1), /* includes "/", but not ":" */
 887                                 buf);
 888                         /* canonicalize it */
 889                         p = bb_simplify_abs_path_inplace(cur->before_colon);
 890                         file_len = p - cur->before_colon;
 891                         /* add "user:pass" after NUL */
 892                         strcpy(++p, after_colon);
 893                         cur->after_colon = p;
 894
 895                         /* insert cur into g_auth */
 896                         /* g_auth is sorted by decreased filename length */
 897                         {
 898                                 Htaccess *auth, **authp;
 899
 900                                 authp = &g_auth;
 901                                 while ((auth = *authp) != NULL) {
 902                                         if (file_len >= strlen(auth->before_colon)) {
 903                                                 /* insert cur before auth */
 904                                                 cur->next = auth;
 905                                                 break;
 906                                         }
 907                                         authp = &auth->next;
 908                                 }
 909                                 *authp = cur;
 910                         }
 911                         continue;
 912                 }
 913 #endif /* BASIC_AUTH */
 914
 915                 /* the line is not recognized */
 916  config_error:
 917                 bb_error_msg("config error '%s' in '%s'", buf, filename);
 918         } /* while (fgets) */
 919
 920         fclose(f);
 921 }
 922
 923 #if ENABLE_FEATURE_HTTPD_ENCODE_URL_STR
 924 /*
 925  * Given a string, html-encode special characters.
 926  * This is used for the -e command line option to provide an easy way
 927  * for scripts to encode result data without confusing browsers.  The
 928  * returned string pointer is memory allocated by malloc().
 929  *
 930  * Returns a pointer to the encoded string (malloced).
 931  */
 932 static char *encodeString(const char *string)
 933 {
 934         /* take the simple route and encode everything */
 935         /* could possibly scan once to get length.     */
 936         int len = strlen(string);
 937         char *out = xmalloc(len * 6 + 1);
 938         char *p = out;
 939         char ch;
 940
 941         while ((ch = *string++) != '\0') {
 942                 /* very simple check for what to encode */
 943                 if (isalnum(ch))
 944                         *p++ = ch;
 945                 else
 946                         p += sprintf(p, "&#%u;", (unsigned char) ch);
 947         }
 948         *p = '\0';
 949         return out;
 950 }
 951 #endif
 952
 953 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
 954 /*
 955  * Decode a base64 data stream as per rfc1521.
 956  * Note that the rfc states that non base64 chars are to be ignored.
 957  * Since the decode always results in a shorter size than the input,
 958  * it is OK to pass the input arg as an output arg.
 959  * Parameter: a pointer to a base64 encoded string.
 960  * Decoded data is stored in-place.
 961  */
 962 static void decodeBase64(char *Data)
 963 {
 964         const unsigned char *in = (const unsigned char *)Data;
 965         /* The decoded size will be at most 3/4 the size of the encoded */
 966         unsigned ch = 0;
 967         int i = 0;
 968
 969         while (*in) {
 970                 int t = *in++;
 971
 972                 if (t >= '0' && t <= '9')
 973                         t = t - '0' + 52;
 974                 else if (t >= 'A' && t <= 'Z')
 975                         t = t - 'A';
 976                 else if (t >= 'a' && t <= 'z')
 977                         t = t - 'a' + 26;
 978                 else if (t == '+')
 979                         t = 62;
 980                 else if (t == '/')
 981                         t = 63;
 982                 else if (t == '=')
 983                         t = 0;
 984                 else
 985                         continue;
 986
 987                 ch = (ch << 6) | t;
 988                 i++;
 989                 if (i == 4) {
 990                         *Data++ = (char) (ch >> 16);
 991                         *Data++ = (char) (ch >> 8);
 992                         *Data++ = (char) ch;
 993                         i = 0;
 994                 }
 995         }
 996         *Data = '\0';
 997 }
 998 #endif
 999
1000 /*
1001  * Create a listen server socket on the designated port.
1002  */
1003 static int openServer(void)
1004 {
1005         unsigned n = bb_strtou(bind_addr_or_port, NULL, 10);
1006         if (!errno && n && n <= 0xffff)
1007                 n = create_and_bind_stream_or_die(NULL, n);
1008         else
1009                 n = create_and_bind_stream_or_die(bind_addr_or_port, 80);
1010         xlisten(n, 9);
1011         return n;
1012 }
1013
1014 /*
1015  * Log the connection closure and exit.
1016  */
1017 static void log_and_exit(void) NORETURN;
1018 static void log_and_exit(void)
1019 {
1020         /* Paranoia. IE said to be buggy. It may send some extra data
1021          * or be confused by us just exiting without SHUT_WR. Oh well. */
1022         shutdown(1, SHUT_WR);
1023         /* Why??
1024         (this also messes up stdin when user runs httpd -i from terminal)
1025         ndelay_on(0);
1026         while (read(STDIN_FILENO, iobuf, IOBUF_SIZE) > 0)
1027                 continue;
1028         */
1029
1030         if (verbose > 2)
1031                 bb_error_msg("closed");
1032         _exit(xfunc_error_retval);
1033 }
1034
1035 /*
1036  * Create and send HTTP response headers.
1037  * The arguments are combined and sent as one write operation.  Note that
1038  * IE will puke big-time if the headers are not sent in one packet and the
1039  * second packet is delayed for any reason.
1040  * responseNum - the result code to send.
1041  */
1042 static void send_headers(unsigned responseNum)
1043 {
1044         static const char RFC1123FMT[] ALIGN1 = "%a, %d %b %Y %H:%M:%S GMT";
1045         /* Fixed size 29-byte string. Example: Sun, 06 Nov 1994 08:49:37 GMT */
1046         char date_str[40]; /* using a bit larger buffer to paranoia reasons */
1047
1048         struct tm tm;
1049         const char *responseString = "";
1050         const char *infoString = NULL;
1051 #if ENABLE_FEATURE_HTTPD_ERROR_PAGES
1052         const char *error_page = NULL;
1053 #endif
1054         unsigned len;
1055         unsigned i;
1056         time_t timer = time(NULL);
1057
1058         for (i = 0; i < ARRAY_SIZE(http_response_type); i++) {
1059                 if (http_response_type[i] == responseNum) {
1060                         responseString = http_response[i].name;
1061                         infoString = http_response[i].info;
1062 #if ENABLE_FEATURE_HTTPD_ERROR_PAGES
1063                         error_page = http_error_page[i];
1064 #endif
1065                         break;
1066                 }
1067         }
1068
1069         if (verbose)
1070                 bb_error_msg("response:%u", responseNum);
1071
1072         /* We use sprintf, not snprintf (it's less code).
1073          * iobuf[] is several kbytes long and all headers we generate
1074          * always fit into those kbytes.
1075          */
1076
1077         strftime(date_str, sizeof(date_str), RFC1123FMT, gmtime_r(&timer, &tm));
1078         /* ^^^ using gmtime_r() instead of gmtime() to not use static data */
1079         len = sprintf(iobuf,
1080                         "HTTP/1.0 %u %s\r\n"
1081                         "Date: %s\r\n"
1082                         "Connection: close\r\n",
1083                         responseNum, responseString,
1084                         date_str
1085         );
1086
1087         if (responseNum != HTTP_OK || found_mime_type) {
1088                 len += sprintf(iobuf + len,
1089                                 "Content-type: %s\r\n",
1090                                 /* if it's error message, then it's HTML */
1091                                 (responseNum != HTTP_OK ? "text/html" : found_mime_type)
1092                 );
1093         }
1094
1095 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
1096         if (responseNum == HTTP_UNAUTHORIZED) {
1097                 len += sprintf(iobuf + len,
1098                                 "WWW-Authenticate: Basic realm=\"%.999s\"\r\n",
1099                                 g_realm /* %.999s protects from overflowing iobuf[] */
1100                 );
1101         }
1102 #endif
1103         if (responseNum == HTTP_MOVED_TEMPORARILY) {
1104                 /* Responding to "GET /dir" with
1105                  * "HTTP/1.0 302 Found" "Location: /dir/"
1106                  * - IOW, asking them to repeat with a slash.
1107                  * Here, overflow IS possible, can't use sprintf:
1108                  * mkdir test
1109                  * python -c 'print("get /test?" + ("x" * 8192))' | busybox httpd -i -h .
1110                  */
1111                 len += snprintf(iobuf + len, IOBUF_SIZE-3 - len,
1112                                 "Location: %s/%s%s\r\n",
1113                                 found_moved_temporarily,
1114                                 (g_query ? "?" : ""),
1115                                 (g_query ? g_query : "")
1116                 );
1117                 if (len > IOBUF_SIZE-3)
1118                         len = IOBUF_SIZE-3;
1119         }
1120
1121 #if ENABLE_FEATURE_HTTPD_ERROR_PAGES
1122         if (error_page && access(error_page, R_OK) == 0) {
1123                 iobuf[len++] = '\r';
1124                 iobuf[len++] = '\n';
1125                 if (DEBUG) {
1126                         iobuf[len] = '\0';
1127                         fprintf(stderr, "headers: '%s'\n", iobuf);
1128                 }
1129                 full_write(STDOUT_FILENO, iobuf, len);
1130                 if (DEBUG)
1131                         fprintf(stderr, "writing error page: '%s'\n", error_page);
1132                 return send_file_and_exit(error_page, SEND_BODY);
1133         }
1134 #endif
1135
1136         if (file_size != -1) {    /* file */
1137                 strftime(date_str, sizeof(date_str), RFC1123FMT, gmtime_r(&last_mod, &tm));
1138 #if ENABLE_FEATURE_HTTPD_RANGES
1139                 if (responseNum == HTTP_PARTIAL_CONTENT) {
1140                         len += sprintf(iobuf + len,
1141                                 "Content-Range: bytes %"OFF_FMT"u-%"OFF_FMT"u/%"OFF_FMT"u\r\n",
1142                                         range_start,
1143                                         range_end,
1144                                         file_size
1145                         );
1146                         file_size = range_end - range_start + 1;
1147                 }
1148 #endif
1149                 len += sprintf(iobuf + len,
1150 #if ENABLE_FEATURE_HTTPD_RANGES
1151                         "Accept-Ranges: bytes\r\n"
1152 #endif
1153                         "Last-Modified: %s\r\n"
1154                         "%s-Length: %"OFF_FMT"u\r\n",
1155                                 date_str,
1156                                 content_gzip ? "Transfer" : "Content",
1157                                 file_size
1158                 );
1159         }
1160
1161         if (content_gzip)
1162                 len += sprintf(iobuf + len, "Content-Encoding: gzip\r\n");
1163
1164         iobuf[len++] = '\r';
1165         iobuf[len++] = '\n';
1166         if (infoString) {
1167                 len += sprintf(iobuf + len,
1168                                 "<HTML><HEAD><TITLE>%u %s</TITLE></HEAD>\n"
1169                                 "<BODY><H1>%u %s</H1>\n"
1170                                 "%s\n"
1171                                 "</BODY></HTML>\n",
1172                                 responseNum, responseString,
1173                                 responseNum, responseString,
1174                                 infoString
1175                 );
1176         }
1177         if (DEBUG) {
1178                 iobuf[len] = '\0';
1179                 fprintf(stderr, "headers: '%s'\n", iobuf);
1180         }
1181         if (full_write(STDOUT_FILENO, iobuf, len) != len) {
1182                 if (verbose > 1)
1183                         bb_perror_msg("error");
1184                 log_and_exit();
1185         }
1186 }
1187
1188 static void send_headers_and_exit(int responseNum) NORETURN;
1189 static void send_headers_and_exit(int responseNum)
1190 {
1191         IF_FEATURE_HTTPD_GZIP(content_gzip = 0;)
1192         send_headers(responseNum);
1193         log_and_exit();
1194 }
1195
1196 /*
1197  * Read from the socket until '\n' or EOF. '\r' chars are removed.
1198  * '\n' is replaced with NUL.
1199  * Return number of characters read or 0 if nothing is read
1200  * ('\r' and '\n' are not counted).
1201  * Data is returned in iobuf.
1202  */
1203 static int get_line(void)
1204 {
1205         int count = 0;
1206         char c;
1207
1208         alarm(HEADER_READ_TIMEOUT);
1209         while (1) {
1210                 if (hdr_cnt <= 0) {
1211                         hdr_cnt = safe_read(STDIN_FILENO, hdr_buf, sizeof_hdr_buf);
1212                         if (hdr_cnt <= 0)
1213                                 break;
1214                         hdr_ptr = hdr_buf;
1215                 }
1216                 iobuf[count] = c = *hdr_ptr++;
1217                 hdr_cnt--;
1218
1219                 if (c == '\r')
1220                         continue;
1221                 if (c == '\n') {
1222                         iobuf[count] = '\0';
1223                         break;
1224                 }
1225                 if (count < (IOBUF_SIZE - 1))      /* check overflow */
1226                         count++;
1227         }
1228         return count;
1229 }
1230
1231 #if ENABLE_FEATURE_HTTPD_CGI || ENABLE_FEATURE_HTTPD_PROXY
1232
1233 /* gcc 4.2.1 fares better with NOINLINE */
1234 static NOINLINE void cgi_io_loop_and_exit(int fromCgi_rd, int toCgi_wr, int post_len) NORETURN;
1235 static NOINLINE void cgi_io_loop_and_exit(int fromCgi_rd, int toCgi_wr, int post_len)
1236 {
1237         enum { FROM_CGI = 1, TO_CGI = 2 }; /* indexes in pfd[] */
1238         struct pollfd pfd[3];
1239         int out_cnt; /* we buffer a bit of initial CGI output */
1240         int count;
1241
1242         /* iobuf is used for CGI -> network data,
1243          * hdr_buf is for network -> CGI data (POSTDATA) */
1244
1245         /* If CGI dies, we still want to correctly finish reading its output
1246          * and send it to the peer. So please no SIGPIPEs! */
1247         signal(SIGPIPE, SIG_IGN);
1248
1249         // We inconsistently handle a case when more POSTDATA from network
1250         // is coming than we expected. We may give *some part* of that
1251         // extra data to CGI.
1252
1253         //if (hdr_cnt > post_len) {
1254         //      /* We got more POSTDATA from network than we expected */
1255         //      hdr_cnt = post_len;
1256         //}
1257         post_len -= hdr_cnt;
1258         /* post_len - number of POST bytes not yet read from network */
1259
1260         /* NB: breaking out of this loop jumps to log_and_exit() */
1261         out_cnt = 0;
1262         pfd[FROM_CGI].fd = fromCgi_rd;
1263         pfd[FROM_CGI].events = POLLIN;
1264         pfd[TO_CGI].fd = toCgi_wr;
1265         while (1) {
1266                 /* Note: even pfd[0].events == 0 won't prevent
1267                  * revents == POLLHUP|POLLERR reports from closed stdin.
1268                  * Setting fd to -1 works: */
1269                 pfd[0].fd = -1;
1270                 pfd[0].events = POLLIN;
1271                 pfd[0].revents = 0; /* probably not needed, paranoia */
1272
1273                 /* We always poll this fd, thus kernel always sets revents: */
1274                 /*pfd[FROM_CGI].events = POLLIN; - moved out of loop */
1275                 /*pfd[FROM_CGI].revents = 0; - not needed */
1276
1277                 /* gcc-4.8.0 still doesnt fill two shorts with one insn :( */
1278                 /* http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47059 */
1279                 /* hopefully one day it will... */
1280                 pfd[TO_CGI].events = POLLOUT;
1281                 pfd[TO_CGI].revents = 0; /* needed! */
1282
1283                 if (toCgi_wr && hdr_cnt <= 0) {
1284                         if (post_len > 0) {
1285                                 /* Expect more POST data from network */
1286                                 pfd[0].fd = 0;
1287                         } else {
1288                                 /* post_len <= 0 && hdr_cnt <= 0:
1289                                  * no more POST data to CGI,
1290                                  * let CGI see EOF on CGI's stdin */
1291                                 if (toCgi_wr != fromCgi_rd)
1292                                         close(toCgi_wr);
1293                                 toCgi_wr = 0;
1294                         }
1295                 }
1296
1297                 /* Now wait on the set of sockets */
1298                 count = safe_poll(pfd, hdr_cnt > 0 ? TO_CGI+1 : FROM_CGI+1, -1);
1299                 if (count <= 0) {
1300 #if 0
1301                         if (safe_waitpid(pid, &status, WNOHANG) <= 0) {
1302                                 /* Weird. CGI didn't exit and no fd's
1303                                  * are ready, yet poll returned?! */
1304                                 continue;
1305                         }
1306                         if (DEBUG && WIFEXITED(status))
1307                                 bb_error_msg("CGI exited, status=%u", WEXITSTATUS(status));
1308                         if (DEBUG && WIFSIGNALED(status))
1309                                 bb_error_msg("CGI killed, signal=%u", WTERMSIG(status));
1310 #endif
1311                         break;
1312                 }
1313
1314                 if (pfd[TO_CGI].revents) {
1315                         /* hdr_cnt > 0 here due to the way poll() called */
1316                         /* Have data from peer and can write to CGI */
1317                         count = safe_write(toCgi_wr, hdr_ptr, hdr_cnt);
1318                         /* Doesn't happen, we dont use nonblocking IO here
1319                          *if (count < 0 && errno == EAGAIN) {
1320                          *      ...
1321                          *} else */
1322                         if (count > 0) {
1323                                 hdr_ptr += count;
1324                                 hdr_cnt -= count;
1325                         } else {
1326                                 /* EOF/broken pipe to CGI, stop piping POST data */
1327                                 hdr_cnt = post_len = 0;
1328                         }
1329                 }
1330
1331                 if (pfd[0].revents) {
1332                         /* post_len > 0 && hdr_cnt == 0 here */
1333                         /* We expect data, prev data portion is eaten by CGI
1334                          * and there *is* data to read from the peer
1335                          * (POSTDATA) */
1336                         //count = post_len > (int)sizeof_hdr_buf ? (int)sizeof_hdr_buf : post_len;
1337                         //count = safe_read(STDIN_FILENO, hdr_buf, count);
1338                         count = safe_read(STDIN_FILENO, hdr_buf, sizeof_hdr_buf);
1339                         if (count > 0) {
1340                                 hdr_cnt = count;
1341                                 hdr_ptr = hdr_buf;
1342                                 post_len -= count;
1343                         } else {
1344                                 /* no more POST data can be read */
1345                                 post_len = 0;
1346                         }
1347                 }
1348
1349                 if (pfd[FROM_CGI].revents) {
1350                         /* There is something to read from CGI */
1351                         char *rbuf = iobuf;
1352
1353                         /* Are we still buffering CGI output? */
1354                         if (out_cnt >= 0) {
1355                                 /* HTTP_200[] has single "\r\n" at the end.
1356                                  * According to http://hoohoo.ncsa.uiuc.edu/cgi/out.html,
1357                                  * CGI scripts MUST send their own header terminated by
1358                                  * empty line, then data. That's why we have only one
1359                                  * <cr><lf> pair here. We will output "200 OK" line
1360                                  * if needed, but CGI still has to provide blank line
1361                                  * between header and body */
1362
1363                                 /* Must use safe_read, not full_read, because
1364                                  * CGI may output a few first bytes and then wait
1365                                  * for POSTDATA without closing stdout.
1366                                  * With full_read we may wait here forever. */
1367                                 count = safe_read(fromCgi_rd, rbuf + out_cnt, PIPE_BUF - 8);
1368                                 if (count <= 0) {
1369                                         /* eof (or error) and there was no "HTTP",
1370                                          * so write it, then write received data */
1371                                         if (out_cnt) {
1372                                                 full_write(STDOUT_FILENO, HTTP_200, sizeof(HTTP_200)-1);
1373                                                 full_write(STDOUT_FILENO, rbuf, out_cnt);
1374                                         }
1375                                         break; /* CGI stdout is closed, exiting */
1376                                 }
1377                                 out_cnt += count;
1378                                 count = 0;
1379                                 /* "Status" header format is: "Status: 302 Redirected\r\n" */
1380                                 if (out_cnt >= 8 && memcmp(rbuf, "Status: ", 8) == 0) {
1381                                         /* send "HTTP/1.0 " */
1382                                         if (full_write(STDOUT_FILENO, HTTP_200, 9) != 9)
1383                                                 break;
1384                                         /* skip "Status: " (including space, sending "HTTP/1.0  NNN" is wrong) */
1385                                         rbuf += 8;
1386                                         count = out_cnt - 8;
1387                                         out_cnt = -1; /* buffering off */
1388                                 } else if (out_cnt >= 4) {
1389                                         /* Did CGI add "HTTP"? */
1390                                         if (memcmp(rbuf, HTTP_200, 4) != 0) {
1391                                                 /* there is no "HTTP", do it ourself */
1392                                                 if (full_write(STDOUT_FILENO, HTTP_200, sizeof(HTTP_200)-1) != sizeof(HTTP_200)-1)
1393                                                         break;
1394                                         }
1395                                         /* Commented out:
1396                                         if (!strstr(rbuf, "ontent-")) {
1397                                                 full_write(s, "Content-type: text/plain\r\n\r\n", 28);
1398                                         }
1399                                          * Counter-example of valid CGI without Content-type:
1400                                          * echo -en "HTTP/1.0 302 Found\r\n"
1401                                          * echo -en "Location: http://www.busybox.net\r\n"
1402                                          * echo -en "\r\n"
1403                                          */
1404                                         count = out_cnt;
1405                                         out_cnt = -1; /* buffering off */
1406                                 }
1407                         } else {
1408                                 count = safe_read(fromCgi_rd, rbuf, PIPE_BUF);
1409                                 if (count <= 0)
1410                                         break;  /* eof (or error) */
1411                         }
1412                         if (full_write(STDOUT_FILENO, rbuf, count) != count)
1413                                 break;
1414                         if (DEBUG)
1415                                 fprintf(stderr, "cgi read %d bytes: '%.*s'\n", count, count, rbuf);
1416                 } /* if (pfd[FROM_CGI].revents) */
1417         } /* while (1) */
1418         log_and_exit();
1419 }
1420 #endif
1421
1422 #if ENABLE_FEATURE_HTTPD_CGI
1423
1424 static void setenv1(const char *name, const char *value)
1425 {
1426         setenv(name, value ? value : "", 1);
1427 }
1428
1429 /*
1430  * Spawn CGI script, forward CGI's stdin/out <=> network
1431  *
1432  * Environment variables are set up and the script is invoked with pipes
1433  * for stdin/stdout.  If a POST is being done the script is fed the POST
1434  * data in addition to setting the QUERY_STRING variable (for GETs or POSTs).
1435  *
1436  * Parameters:
1437  * const char *url              The requested URL (with leading /).
1438  * const char *orig_uri         The original URI before rewriting (if any)
1439  * int post_len                 Length of the POST body.
1440  * const char *cookie           For set HTTP_COOKIE.
1441  * const char *content_type     For set CONTENT_TYPE.
1442  */
1443 static void send_cgi_and_exit(
1444                 const char *url,
1445                 const char *orig_uri,
1446                 const char *request,
1447                 int post_len,
1448                 const char *cookie,
1449                 const char *content_type) NORETURN;
1450 static void send_cgi_and_exit(
1451                 const char *url,
1452                 const char *orig_uri,
1453                 const char *request,
1454                 int post_len,
1455                 const char *cookie,
1456                 const char *content_type)
1457 {
1458         struct fd_pair fromCgi;  /* CGI -> httpd pipe */
1459         struct fd_pair toCgi;    /* httpd -> CGI pipe */
1460         char *script, *last_slash;
1461         int pid;
1462
1463         /* Make a copy. NB: caller guarantees:
1464          * url[0] == '/', url[1] != '/' */
1465         url = xstrdup(url);
1466
1467         /*
1468          * We are mucking with environment _first_ and then vfork/exec,
1469          * this allows us to use vfork safely. Parent doesn't care about
1470          * these environment changes anyway.
1471          */
1472
1473         /* Check for [dirs/]script.cgi/PATH_INFO */
1474         last_slash = script = (char*)url;
1475         while ((script = strchr(script + 1, '/')) != NULL) {
1476                 int dir;
1477                 *script = '\0';
1478                 dir = is_directory(url + 1, /*followlinks:*/ 1);
1479                 *script = '/';
1480                 if (!dir) {
1481                         /* not directory, found script.cgi/PATH_INFO */
1482                         break;
1483                 }
1484                 /* is directory, find next '/' */
1485                 last_slash = script;
1486         }
1487         setenv1("PATH_INFO", script);   /* set to /PATH_INFO or "" */
1488         setenv1("REQUEST_METHOD", request);
1489         if (g_query) {
1490                 putenv(xasprintf("%s=%s?%s", "REQUEST_URI", orig_uri, g_query));
1491         } else {
1492                 setenv1("REQUEST_URI", orig_uri);
1493         }
1494         if (script != NULL)
1495                 *script = '\0';         /* cut off /PATH_INFO */
1496
1497         /* SCRIPT_FILENAME is required by PHP in CGI mode */
1498         if (home_httpd[0] == '/') {
1499                 char *fullpath = concat_path_file(home_httpd, url);
1500                 setenv1("SCRIPT_FILENAME", fullpath);
1501         }
1502         /* set SCRIPT_NAME as full path: /cgi-bin/dirs/script.cgi */
1503         setenv1("SCRIPT_NAME", url);
1504         /* http://hoohoo.ncsa.uiuc.edu/cgi/env.html:
1505          * QUERY_STRING: The information which follows the ? in the URL
1506          * which referenced this script. This is the query information.
1507          * It should not be decoded in any fashion. This variable
1508          * should always be set when there is query information,
1509          * regardless of command line decoding. */
1510         /* (Older versions of bbox seem to do some decoding) */
1511         setenv1("QUERY_STRING", g_query);
1512         putenv((char*)"SERVER_SOFTWARE=busybox httpd/"BB_VER);
1513         putenv((char*)"SERVER_PROTOCOL=HTTP/1.0");
1514         putenv((char*)"GATEWAY_INTERFACE=CGI/1.1");
1515         /* Having _separate_ variables for IP and port defeats
1516          * the purpose of having socket abstraction. Which "port"
1517          * are you using on Unix domain socket?
1518          * IOW - REMOTE_PEER="1.2.3.4:56" makes much more sense.
1519          * Oh well... */
1520         {
1521                 char *p = rmt_ip_str ? rmt_ip_str : (char*)"";
1522                 char *cp = strrchr(p, ':');
1523                 if (ENABLE_FEATURE_IPV6 && cp && strchr(cp, ']'))
1524                         cp = NULL;
1525                 if (cp) *cp = '\0'; /* delete :PORT */
1526                 setenv1("REMOTE_ADDR", p);
1527                 if (cp) {
1528                         *cp = ':';
1529 #if ENABLE_FEATURE_HTTPD_SET_REMOTE_PORT_TO_ENV
1530                         setenv1("REMOTE_PORT", cp + 1);
1531 #endif
1532                 }
1533         }
1534         setenv1("HTTP_USER_AGENT", G.user_agent);
1535         if (G.http_accept)
1536                 setenv1("HTTP_ACCEPT", G.http_accept);
1537         if (G.http_accept_language)
1538                 setenv1("HTTP_ACCEPT_LANGUAGE", G.http_accept_language);
1539         if (post_len)
1540                 putenv(xasprintf("CONTENT_LENGTH=%u", post_len));
1541         if (cookie)
1542                 setenv1("HTTP_COOKIE", cookie);
1543         if (content_type)
1544                 setenv1("CONTENT_TYPE", content_type);
1545 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
1546         if (remoteuser) {
1547                 setenv1("REMOTE_USER", remoteuser);
1548                 putenv((char*)"AUTH_TYPE=Basic");
1549         }
1550 #endif
1551         if (G.referer)
1552                 setenv1("HTTP_REFERER", G.referer);
1553         setenv1("HTTP_HOST", G.host); /* set to "" if NULL */
1554         /* setenv1("SERVER_NAME", safe_gethostname()); - don't do this,
1555          * just run "env SERVER_NAME=xyz httpd ..." instead */
1556
1557         xpiped_pair(fromCgi);
1558         xpiped_pair(toCgi);
1559
1560         pid = vfork();
1561         if (pid < 0) {
1562                 /* TODO: log perror? */
1563                 log_and_exit();
1564         }
1565
1566         if (pid == 0) {
1567                 /* Child process */
1568                 char *argv[3];
1569
1570                 xfunc_error_retval = 242;
1571
1572                 /* NB: close _first_, then move fds! */
1573                 close(toCgi.wr);
1574                 close(fromCgi.rd);
1575                 xmove_fd(toCgi.rd, 0);  /* replace stdin with the pipe */
1576                 xmove_fd(fromCgi.wr, 1);  /* replace stdout with the pipe */
1577                 /* User seeing stderr output can be a security problem.
1578                  * If CGI really wants that, it can always do dup itself. */
1579                 /* dup2(1, 2); */
1580
1581                 /* Chdiring to script's dir */
1582                 script = last_slash;
1583                 if (script != url) { /* paranoia */
1584                         *script = '\0';
1585                         if (chdir(url + 1) != 0) {
1586                                 bb_perror_msg("can't change directory to '%s'", url + 1);
1587                                 goto error_execing_cgi;
1588                         }
1589                         // not needed: *script = '/';
1590                 }
1591                 script++;
1592
1593                 /* set argv[0] to name without path */
1594                 argv[0] = script;
1595                 argv[1] = NULL;
1596
1597 #if ENABLE_FEATURE_HTTPD_CONFIG_WITH_SCRIPT_INTERPR
1598                 {
1599                         char *suffix = strrchr(script, '.');
1600
1601                         if (suffix) {
1602                                 Htaccess *cur;
1603                                 for (cur = script_i; cur; cur = cur->next) {
1604                                         if (strcmp(cur->before_colon + 1, suffix) == 0) {
1605                                                 /* found interpreter name */
1606                                                 argv[0] = cur->after_colon;
1607                                                 argv[1] = script;
1608                                                 argv[2] = NULL;
1609                                                 break;
1610                                         }
1611                                 }
1612                         }
1613                 }
1614 #endif
1615                 /* restore default signal dispositions for CGI process */
1616                 bb_signals(0
1617                         | (1 << SIGCHLD)
1618                         | (1 << SIGPIPE)
1619                         | (1 << SIGHUP)
1620                         , SIG_DFL);
1621
1622                 /* _NOT_ execvp. We do not search PATH. argv[0] is a filename
1623                  * without any dir components and will only match a file
1624                  * in the current directory */
1625                 execv(argv[0], argv);
1626                 if (verbose)
1627                         bb_perror_msg("can't execute '%s'", argv[0]);
1628  error_execing_cgi:
1629                 /* send to stdout
1630                  * (we are CGI here, our stdout is pumped to the net) */
1631                 send_headers_and_exit(HTTP_NOT_FOUND);
1632         } /* end child */
1633
1634         /* Parent process */
1635
1636         /* Restore variables possibly changed by child */
1637         xfunc_error_retval = 0;
1638
1639         /* Pump data */
1640         close(fromCgi.wr);
1641         close(toCgi.rd);
1642         cgi_io_loop_and_exit(fromCgi.rd, toCgi.wr, post_len);
1643 }
1644
1645 #endif          /* FEATURE_HTTPD_CGI */
1646
1647 /*
1648  * Send a file response to a HTTP request, and exit
1649  *
1650  * Parameters:
1651  * const char *url  The requested URL (with leading /).
1652  * what             What to send (headers/body/both).
1653  */
1654 static NOINLINE void send_file_and_exit(const char *url, int what)
1655 {
1656         char *suffix;
1657         int fd;
1658         ssize_t count;
1659
1660         if (content_gzip) {
1661                 /* does <url>.gz exist? Then use it instead */
1662                 char *gzurl = xasprintf("%s.gz", url);
1663                 fd = open(gzurl, O_RDONLY);
1664                 free(gzurl);
1665                 if (fd != -1) {
1666                         struct stat sb;
1667                         fstat(fd, &sb);
1668                         file_size = sb.st_size;
1669                         last_mod = sb.st_mtime;
1670                 } else {
1671                         IF_FEATURE_HTTPD_GZIP(content_gzip = 0;)
1672                         fd = open(url, O_RDONLY);
1673                 }
1674         } else {
1675                 fd = open(url, O_RDONLY);
1676         }
1677         if (fd < 0) {
1678                 if (DEBUG)
1679                         bb_perror_msg("can't open '%s'", url);
1680                 /* Error pages are sent by using send_file_and_exit(SEND_BODY).
1681                  * IOW: it is unsafe to call send_headers_and_exit
1682                  * if what is SEND_BODY! Can recurse! */
1683                 if (what != SEND_BODY)
1684                         send_headers_and_exit(HTTP_NOT_FOUND);
1685                 log_and_exit();
1686         }
1687         /* If you want to know about EPIPE below
1688          * (happens if you abort downloads from local httpd): */
1689         signal(SIGPIPE, SIG_IGN);
1690
1691         /* If not found, default is to not send "Content-type:" */
1692         /*found_mime_type = NULL; - already is */
1693         suffix = strrchr(url, '.');
1694         if (suffix) {
1695                 static const char suffixTable[] ALIGN1 =
1696                         /* Shorter suffix must be first:
1697                          * ".html.htm" will fail for ".htm"
1698                          */
1699                         ".txt.h.c.cc.cpp\0" "text/plain\0"
1700                         /* .htm line must be after .h line */
1701                         ".htm.html\0" "text/html\0"
1702                         ".jpg.jpeg\0" "image/jpeg\0"
1703                         ".gif\0"      "image/gif\0"
1704                         ".png\0"      "image/png\0"
1705                         /* .css line must be after .c line */
1706                         ".css\0"      "text/css\0"
1707                         ".wav\0"      "audio/wav\0"
1708                         ".avi\0"      "video/x-msvideo\0"
1709                         ".qt.mov\0"   "video/quicktime\0"
1710                         ".mpe.mpeg\0" "video/mpeg\0"
1711                         ".mid.midi\0" "audio/midi\0"
1712                         ".mp3\0"      "audio/mpeg\0"
1713 #if 0  /* unpopular */
1714                         ".au\0"       "audio/basic\0"
1715                         ".pac\0"      "application/x-ns-proxy-autoconfig\0"
1716                         ".vrml.wrl\0" "model/vrml\0"
1717 #endif
1718                         /* compiler adds another "\0" here */
1719                 ;
1720                 Htaccess *cur;
1721
1722                 /* Examine built-in table */
1723                 const char *table = suffixTable;
1724                 const char *table_next;
1725                 for (; *table; table = table_next) {
1726                         const char *try_suffix;
1727                         const char *mime_type;
1728                         mime_type  = table + strlen(table) + 1;
1729                         table_next = mime_type + strlen(mime_type) + 1;
1730                         try_suffix = strstr(table, suffix);
1731                         if (!try_suffix)
1732                                 continue;
1733                         try_suffix += strlen(suffix);
1734                         if (*try_suffix == '\0' || *try_suffix == '.') {
1735                                 found_mime_type = mime_type;
1736                                 break;
1737                         }
1738                         /* Example: strstr(table, ".av") != NULL, but it
1739                          * does not match ".avi" after all and we end up here.
1740                          * The table is arranged so that in this case we know
1741                          * that it can't match anything in the following lines,
1742                          * and we stop the search: */
1743                         break;
1744                 }
1745                 /* ...then user's table */
1746                 for (cur = mime_a; cur; cur = cur->next) {
1747                         if (strcmp(cur->before_colon, suffix) == 0) {
1748                                 found_mime_type = cur->after_colon;
1749                                 break;
1750                         }
1751                 }
1752         }
1753
1754         if (DEBUG)
1755                 bb_error_msg("sending file '%s' content-type: %s",
1756                         url, found_mime_type);
1757
1758 #if ENABLE_FEATURE_HTTPD_RANGES
1759         if (what == SEND_BODY /* err pages and ranges don't mix */
1760          || content_gzip /* we are sending compressed page: can't do ranges */  ///why?
1761         ) {
1762                 range_start = -1;
1763         }
1764         range_len = MAXINT(off_t);
1765         if (range_start >= 0) {
1766                 if (!range_end || range_end > file_size - 1) {
1767                         range_end = file_size - 1;
1768                 }
1769                 if (range_end < range_start
1770                  || lseek(fd, range_start, SEEK_SET) != range_start
1771                 ) {
1772                         lseek(fd, 0, SEEK_SET);
1773                         range_start = -1;
1774                 } else {
1775                         range_len = range_end - range_start + 1;
1776                         send_headers(HTTP_PARTIAL_CONTENT);
1777                         what = SEND_BODY;
1778                 }
1779         }
1780 #endif
1781         if (what & SEND_HEADERS)
1782                 send_headers(HTTP_OK);
1783 #if ENABLE_FEATURE_USE_SENDFILE
1784         {
1785                 off_t offset = range_start;
1786                 while (1) {
1787                         /* sz is rounded down to 64k */
1788                         ssize_t sz = MAXINT(ssize_t) - 0xffff;
1789                         IF_FEATURE_HTTPD_RANGES(if (sz > range_len) sz = range_len;)
1790                         count = sendfile(STDOUT_FILENO, fd, &offset, sz);
1791                         if (count < 0) {
1792                                 if (offset == range_start)
1793                                         break; /* fall back to read/write loop */
1794                                 goto fin;
1795                         }
1796                         IF_FEATURE_HTTPD_RANGES(range_len -= count;)
1797                         if (count == 0 || range_len == 0)
1798                                 log_and_exit();
1799                 }
1800         }
1801 #endif
1802         while ((count = safe_read(fd, iobuf, IOBUF_SIZE)) > 0) {
1803                 ssize_t n;
1804                 IF_FEATURE_HTTPD_RANGES(if (count > range_len) count = range_len;)
1805                 n = full_write(STDOUT_FILENO, iobuf, count);
1806                 if (count != n)
1807                         break;
1808                 IF_FEATURE_HTTPD_RANGES(range_len -= count;)
1809                 if (range_len == 0)
1810                         break;
1811         }
1812         if (count < 0) {
1813  IF_FEATURE_USE_SENDFILE(fin:)
1814                 if (verbose > 1)
1815                         bb_perror_msg("error");
1816         }
1817         log_and_exit();
1818 }
1819
1820 static int checkPermIP(void)
1821 {
1822         Htaccess_IP *cur;
1823
1824         for (cur = ip_a_d; cur; cur = cur->next) {
1825 #if DEBUG
1826                 fprintf(stderr,
1827                         "checkPermIP: '%s' ? '%u.%u.%u.%u/%u.%u.%u.%u'\n",
1828                         rmt_ip_str,
1829                         (unsigned char)(cur->ip >> 24),
1830                         (unsigned char)(cur->ip >> 16),
1831                         (unsigned char)(cur->ip >> 8),
1832                         (unsigned char)(cur->ip),
1833                         (unsigned char)(cur->mask >> 24),
1834                         (unsigned char)(cur->mask >> 16),
1835                         (unsigned char)(cur->mask >> 8),
1836                         (unsigned char)(cur->mask)
1837                 );
1838 #endif
1839                 if ((rmt_ip & cur->mask) == cur->ip)
1840                         return (cur->allow_deny == 'A'); /* A -> 1 */
1841         }
1842
1843         return !flg_deny_all; /* depends on whether we saw "D:*" */
1844 }
1845
1846 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
1847
1848 # if ENABLE_PAM
1849 struct pam_userinfo {
1850         const char *name;
1851         const char *pw;
1852 };
1853
1854 static int pam_talker(int num_msg,
1855                 const struct pam_message **msg,
1856                 struct pam_response **resp,
1857                 void *appdata_ptr)
1858 {
1859         int i;
1860         struct pam_userinfo *userinfo = (struct pam_userinfo *) appdata_ptr;
1861         struct pam_response *response;
1862
1863         if (!resp || !msg || !userinfo)
1864                 return PAM_CONV_ERR;
1865
1866         /* allocate memory to store response */
1867         response = xzalloc(num_msg * sizeof(*response));
1868
1869         /* copy values */
1870         for (i = 0; i < num_msg; i++) {
1871                 const char *s;
1872
1873                 switch (msg[i]->msg_style) {
1874                 case PAM_PROMPT_ECHO_ON:
1875                         s = userinfo->name;
1876                         break;
1877                 case PAM_PROMPT_ECHO_OFF:
1878                         s = userinfo->pw;
1879                         break;
1880                 case PAM_ERROR_MSG:
1881                 case PAM_TEXT_INFO:
1882                         s = "";
1883                         break;
1884                 default:
1885                         free(response);
1886                         return PAM_CONV_ERR;
1887                 }
1888                 response[i].resp = xstrdup(s);
1889                 if (PAM_SUCCESS != 0)
1890                         response[i].resp_retcode = PAM_SUCCESS;
1891         }
1892         *resp = response;
1893         return PAM_SUCCESS;
1894 }
1895 # endif
1896
1897 /*
1898  * Config file entries are of the form "/<path>:<user>:<passwd>".
1899  * If config file has no prefix match for path, access is allowed.
1900  *
1901  * path                 The file path
1902  * user_and_passwd      "user:passwd" to validate
1903  *
1904  * Returns 1 if user_and_passwd is OK.
1905  */
1906 static int check_user_passwd(const char *path, char *user_and_passwd)
1907 {
1908         Htaccess *cur;
1909         const char *prev = NULL;
1910
1911         for (cur = g_auth; cur; cur = cur->next) {
1912                 const char *dir_prefix;
1913                 size_t len;
1914                 int r;
1915
1916                 dir_prefix = cur->before_colon;
1917
1918                 /* WHY? */
1919                 /* If already saw a match, don't accept other different matches */
1920                 if (prev && strcmp(prev, dir_prefix) != 0)
1921                         continue;
1922
1923                 if (DEBUG)
1924                         fprintf(stderr, "checkPerm: '%s' ? '%s'\n", dir_prefix, user_and_passwd);
1925
1926                 /* If it's not a prefix match, continue searching */
1927                 len = strlen(dir_prefix);
1928                 if (len != 1 /* dir_prefix "/" matches all, don't need to check */
1929                  && (strncmp(dir_prefix, path, len) != 0
1930                     || (path[len] != '/' && path[len] != '\0')
1931                     )
1932                 ) {
1933                         continue;
1934                 }
1935
1936                 /* Path match found */
1937                 prev = dir_prefix;
1938
1939                 if (ENABLE_FEATURE_HTTPD_AUTH_MD5) {
1940                         char *colon_after_user;
1941                         const char *passwd;
1942 # if ENABLE_FEATURE_SHADOWPASSWDS && !ENABLE_PAM
1943                         char sp_buf[256];
1944 # endif
1945
1946                         colon_after_user = strchr(user_and_passwd, ':');
1947                         if (!colon_after_user)
1948                                 goto bad_input;
1949
1950                         /* compare "user:" */
1951                         if (cur->after_colon[0] != '*'
1952                          && strncmp(cur->after_colon, user_and_passwd,
1953                                         colon_after_user - user_and_passwd + 1) != 0
1954                         ) {
1955                                 continue;
1956                         }
1957                         /* this cfg entry is '*' or matches username from peer */
1958
1959                         passwd = strchr(cur->after_colon, ':');
1960                         if (!passwd)
1961                                 goto bad_input;
1962                         passwd++;
1963                         if (passwd[0] == '*') {
1964 # if ENABLE_PAM
1965                                 struct pam_userinfo userinfo;
1966                                 struct pam_conv conv_info = { &pam_talker, (void *) &userinfo };
1967                                 pam_handle_t *pamh;
1968
1969                                 *colon_after_user = '\0';
1970                                 userinfo.name = user_and_passwd;
1971                                 userinfo.pw = colon_after_user + 1;
1972                                 r = pam_start("httpd", user_and_passwd, &conv_info, &pamh) != PAM_SUCCESS;
1973                                 if (r == 0) {
1974                                         r = pam_authenticate(pamh, PAM_DISALLOW_NULL_AUTHTOK) != PAM_SUCCESS
1975                                          || pam_acct_mgmt(pamh, PAM_DISALLOW_NULL_AUTHTOK)    != PAM_SUCCESS
1976                                         ;
1977                                         pam_end(pamh, PAM_SUCCESS);
1978                                 }
1979                                 *colon_after_user = ':';
1980                                 goto end_check_passwd;
1981 # else
1982 #  if ENABLE_FEATURE_SHADOWPASSWDS
1983                                 /* Using _r function to avoid pulling in static buffers */
1984                                 struct spwd spw;
1985 #  endif
1986                                 struct passwd *pw;
1987
1988                                 *colon_after_user = '\0';
1989                                 pw = getpwnam(user_and_passwd);
1990                                 *colon_after_user = ':';
1991                                 if (!pw || !pw->pw_passwd)
1992                                         continue;
1993                                 passwd = pw->pw_passwd;
1994 #  if ENABLE_FEATURE_SHADOWPASSWDS
1995                                 if ((passwd[0] == 'x' || passwd[0] == '*') && !passwd[1]) {
1996                                         /* getspnam_r may return 0 yet set result to NULL.
1997                                          * At least glibc 2.4 does this. Be extra paranoid here. */
1998                                         struct spwd *result = NULL;
1999                                         r = getspnam_r(pw->pw_name, &spw, sp_buf, sizeof(sp_buf), &result);
2000                                         if (r == 0 && result)
2001                                                 passwd = result->sp_pwdp;
2002                                 }
2003 #  endif
2004                                 /* In this case, passwd is ALWAYS encrypted:
2005                                  * it came from /etc/passwd or /etc/shadow!
2006                                  */
2007                                 goto check_encrypted;
2008 # endif /* ENABLE_PAM */
2009                         }
2010                         /* Else: passwd is from httpd.conf, it is either plaintext or encrypted */
2011
2012                         if (passwd[0] == '$' && isdigit(passwd[1])) {
2013                                 char *encrypted;
2014 # if !ENABLE_PAM
2015  check_encrypted:
2016 # endif
2017                                 /* encrypt pwd from peer and check match with local one */
2018                                 encrypted = pw_encrypt(
2019                                         /* pwd (from peer): */  colon_after_user + 1,
2020                                         /* salt: */ passwd,
2021                                         /* cleanup: */ 0
2022                                 );
2023                                 r = strcmp(encrypted, passwd);
2024                                 free(encrypted);
2025                         } else {
2026                                 /* local passwd is from httpd.conf and it's plaintext */
2027                                 r = strcmp(colon_after_user + 1, passwd);
2028                         }
2029                         goto end_check_passwd;
2030                 }
2031  bad_input:
2032                 /* Comparing plaintext "user:pass" in one go */
2033                 r = strcmp(cur->after_colon, user_and_passwd);
2034  end_check_passwd:
2035                 if (r == 0) {
2036                         remoteuser = xstrndup(user_and_passwd,
2037                                 strchrnul(user_and_passwd, ':') - user_and_passwd
2038                         );
2039                         return 1; /* Ok */
2040                 }
2041         } /* for */
2042
2043         /* 0(bad) if prev is set: matches were found but passwd was wrong */
2044         return (prev == NULL);
2045 }
2046 #endif  /* FEATURE_HTTPD_BASIC_AUTH */
2047
2048 #if ENABLE_FEATURE_HTTPD_PROXY
2049 static Htaccess_Proxy *find_proxy_entry(const char *url)
2050 {
2051         Htaccess_Proxy *p;
2052         for (p = proxy; p; p = p->next) {
2053                 if (is_prefixed_with(url, p->url_from))
2054                         return p;
2055         }
2056         return NULL;
2057 }
2058 #endif
2059
2060 /*
2061  * Handle timeouts
2062  */
2063 static void send_REQUEST_TIMEOUT_and_exit(int sig) NORETURN;
2064 static void send_REQUEST_TIMEOUT_and_exit(int sig UNUSED_PARAM)
2065 {
2066         send_headers_and_exit(HTTP_REQUEST_TIMEOUT);
2067 }
2068
2069 /*
2070  * Handle an incoming http request and exit.
2071  */
2072 static void handle_incoming_and_exit(const len_and_sockaddr *fromAddr) NORETURN;
2073 static void handle_incoming_and_exit(const len_and_sockaddr *fromAddr)
2074 {
2075         static const char request_GET[] ALIGN1 = "GET";
2076         struct stat sb;
2077         char *urlcopy;
2078         char *urlp;
2079         char *tptr;
2080 #if ENABLE_FEATURE_HTTPD_CGI
2081         static const char request_HEAD[] ALIGN1 = "HEAD";
2082         const char *prequest;
2083         char *cookie = NULL;
2084         char *content_type = NULL;
2085         unsigned long length = 0;
2086 #elif ENABLE_FEATURE_HTTPD_PROXY
2087 #define prequest request_GET
2088         unsigned long length = 0;
2089 #endif
2090 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
2091         smallint authorized = -1;
2092 #endif
2093         smallint ip_allowed;
2094         char http_major_version;
2095 #if ENABLE_FEATURE_HTTPD_PROXY
2096         char http_minor_version;
2097         char *header_buf = header_buf; /* for gcc */
2098         char *header_ptr = header_ptr;
2099         Htaccess_Proxy *proxy_entry;
2100 #endif
2101
2102         /* Allocation of iobuf is postponed until now
2103          * (IOW, server process doesn't need to waste 8k) */
2104         iobuf = xmalloc(IOBUF_SIZE);
2105
2106         rmt_ip = 0;
2107         if (fromAddr->u.sa.sa_family == AF_INET) {
2108                 rmt_ip = ntohl(fromAddr->u.sin.sin_addr.s_addr);
2109         }
2110 #if ENABLE_FEATURE_IPV6
2111         if (fromAddr->u.sa.sa_family == AF_INET6
2112          && fromAddr->u.sin6.sin6_addr.s6_addr32[0] == 0
2113          && fromAddr->u.sin6.sin6_addr.s6_addr32[1] == 0
2114          && ntohl(fromAddr->u.sin6.sin6_addr.s6_addr32[2]) == 0xffff)
2115                 rmt_ip = ntohl(fromAddr->u.sin6.sin6_addr.s6_addr32[3]);
2116 #endif
2117         if (ENABLE_FEATURE_HTTPD_CGI || DEBUG || verbose) {
2118                 /* NB: can be NULL (user runs httpd -i by hand?) */
2119                 rmt_ip_str = xmalloc_sockaddr2dotted(&fromAddr->u.sa);
2120         }
2121         if (verbose) {
2122                 /* this trick makes -v logging much simpler */
2123                 if (rmt_ip_str)
2124                         applet_name = rmt_ip_str;
2125                 if (verbose > 2)
2126                         bb_error_msg("connected");
2127         }
2128
2129         /* Install timeout handler. get_line() needs it. */
2130         signal(SIGALRM, send_REQUEST_TIMEOUT_and_exit);
2131
2132         if (!get_line()) /* EOF or error or empty line */
2133                 send_headers_and_exit(HTTP_BAD_REQUEST);
2134
2135         /* Determine type of request (GET/POST) */
2136         // rfc2616: method and URI is separated by exactly one space
2137         //urlp = strpbrk(iobuf, " \t"); - no, tab isn't allowed
2138         urlp = strchr(iobuf, ' ');
2139         if (urlp == NULL)
2140                 send_headers_and_exit(HTTP_BAD_REQUEST);
2141         *urlp++ = '\0';
2142 #if ENABLE_FEATURE_HTTPD_CGI
2143         prequest = request_GET;
2144         if (strcasecmp(iobuf, prequest) != 0) {
2145                 prequest = request_HEAD;
2146                 if (strcasecmp(iobuf, prequest) != 0) {
2147                         prequest = "POST";
2148                         if (strcasecmp(iobuf, prequest) != 0)
2149                                 send_headers_and_exit(HTTP_NOT_IMPLEMENTED);
2150                 }
2151         }
2152 #else
2153         if (strcasecmp(iobuf, request_GET) != 0)
2154                 send_headers_and_exit(HTTP_NOT_IMPLEMENTED);
2155 #endif
2156         // rfc2616: method and URI is separated by exactly one space
2157         //urlp = skip_whitespace(urlp); - should not be necessary
2158         if (urlp[0] != '/')
2159                 send_headers_and_exit(HTTP_BAD_REQUEST);
2160
2161         /* Find end of URL and parse HTTP version, if any */
2162         http_major_version = '0';
2163         IF_FEATURE_HTTPD_PROXY(http_minor_version = '0';)
2164         tptr = strchrnul(urlp, ' ');
2165         /* Is it " HTTP/"? */
2166         if (tptr[0] && strncmp(tptr + 1, HTTP_200, 5) == 0) {
2167                 http_major_version = tptr[6];
2168                 IF_FEATURE_HTTPD_PROXY(http_minor_version = tptr[8];)
2169         }
2170         *tptr = '\0';
2171
2172         /* Copy URL from after "GET "/"POST " to stack-allocated char[] */
2173         urlcopy = alloca((tptr - urlp) + 2 + strlen(index_page));
2174         /*if (urlcopy == NULL)
2175          *      send_headers_and_exit(HTTP_INTERNAL_SERVER_ERROR);*/
2176         strcpy(urlcopy, urlp);
2177         /* NB: urlcopy ptr is never changed after this */
2178
2179         /* Extract url args if present */
2180         /* g_query = NULL; - already is */
2181         tptr = strchr(urlcopy, '?');
2182         if (tptr) {
2183                 *tptr++ = '\0';
2184                 g_query = tptr;
2185         }
2186
2187         /* Decode URL escape sequences */
2188         tptr = percent_decode_in_place(urlcopy, /*strict:*/ 1);
2189         if (tptr == NULL)
2190                 send_headers_and_exit(HTTP_BAD_REQUEST);
2191         if (tptr == urlcopy + 1) {
2192                 /* '/' or NUL is encoded */
2193                 send_headers_and_exit(HTTP_NOT_FOUND);
2194         }
2195
2196         /* Canonicalize path */
2197         /* Algorithm stolen from libbb bb_simplify_path(),
2198          * but don't strdup, retain trailing slash, protect root */
2199         urlp = tptr = urlcopy;
2200         for (;;) {
2201                 if (*urlp == '/') {
2202                         /* skip duplicate (or initial) slash */
2203                         if (*tptr == '/') {
2204                                 goto next_char;
2205                         }
2206                         if (*tptr == '.') {
2207                                 if (tptr[1] == '.' && (tptr[2] == '/' || tptr[2] == '\0')) {
2208                                         /* "..": be careful */
2209                                         /* protect root */
2210                                         if (urlp == urlcopy)
2211                                                 send_headers_and_exit(HTTP_BAD_REQUEST);
2212                                         /* omit previous dir */
2213                                         while (*--urlp != '/')
2214                                                 continue;
2215                                         /* skip to "./" or ".<NUL>" */
2216                                         tptr++;
2217                                 }
2218                                 if (tptr[1] == '/' || tptr[1] == '\0') {
2219                                         /* skip extra "/./" */
2220                                         goto next_char;
2221                                 }
2222                         }
2223                 }
2224                 *++urlp = *tptr;
2225                 if (*urlp == '\0')
2226                         break;
2227  next_char:
2228                 tptr++;
2229         }
2230
2231         /* If URL is a directory, add '/' */
2232         if (urlp[-1] != '/') {
2233                 if (is_directory(urlcopy + 1, /*followlinks:*/ 1)) {
2234                         found_moved_temporarily = urlcopy;
2235                 }
2236         }
2237
2238         /* Log it */
2239         if (verbose > 1)
2240                 bb_error_msg("url:%s", urlcopy);
2241
2242         tptr = urlcopy;
2243         ip_allowed = checkPermIP();
2244         while (ip_allowed && (tptr = strchr(tptr + 1, '/')) != NULL) {
2245                 /* have path1/path2 */
2246                 *tptr = '\0';
2247                 if (is_directory(urlcopy + 1, /*followlinks:*/ 1)) {
2248                         /* may have subdir config */
2249                         parse_conf(urlcopy + 1, SUBDIR_PARSE);
2250                         ip_allowed = checkPermIP();
2251                 }
2252                 *tptr = '/';
2253         }
2254
2255 #if ENABLE_FEATURE_HTTPD_PROXY
2256         proxy_entry = find_proxy_entry(urlcopy);
2257         if (proxy_entry)
2258                 header_buf = header_ptr = xmalloc(IOBUF_SIZE);
2259 #endif
2260
2261         if (http_major_version >= '0') {
2262                 /* Request was with "... HTTP/nXXX", and n >= 0 */
2263
2264                 /* Read until blank line */
2265                 while (1) {
2266                         if (!get_line())
2267                                 break; /* EOF or error or empty line */
2268                         if (DEBUG)
2269                                 bb_error_msg("header: '%s'", iobuf);
2270
2271 #if ENABLE_FEATURE_HTTPD_PROXY
2272                         /* We need 2 more bytes for yet another "\r\n" -
2273                          * see near fdprintf(proxy_fd...) further below */
2274                         if (proxy_entry && (header_ptr - header_buf) < IOBUF_SIZE - 4) {
2275                                 int len = strnlen(iobuf, IOBUF_SIZE - (header_ptr - header_buf) - 4);
2276                                 memcpy(header_ptr, iobuf, len);
2277                                 header_ptr += len;
2278                                 header_ptr[0] = '\r';
2279                                 header_ptr[1] = '\n';
2280                                 header_ptr += 2;
2281                         }
2282 #endif
2283
2284 #if ENABLE_FEATURE_HTTPD_CGI || ENABLE_FEATURE_HTTPD_PROXY
2285                         /* Try and do our best to parse more lines */
2286                         if ((STRNCASECMP(iobuf, "Content-Length:") == 0)) {
2287                                 /* extra read only for POST */
2288                                 if (prequest != request_GET
2289 # if ENABLE_FEATURE_HTTPD_CGI
2290                                  && prequest != request_HEAD
2291 # endif
2292                                 ) {
2293                                         tptr = skip_whitespace(iobuf + sizeof("Content-Length:") - 1);
2294                                         if (!tptr[0])
2295                                                 send_headers_and_exit(HTTP_BAD_REQUEST);
2296                                         /* not using strtoul: it ignores leading minus! */
2297                                         length = bb_strtou(tptr, NULL, 10);
2298                                         /* length is "ulong", but we need to pass it to int later */
2299                                         if (errno || length > INT_MAX)
2300                                                 send_headers_and_exit(HTTP_BAD_REQUEST);
2301                                 }
2302                         }
2303 #endif
2304 #if ENABLE_FEATURE_HTTPD_CGI
2305                         else if (STRNCASECMP(iobuf, "Cookie:") == 0) {
2306                                 if (!cookie) /* in case they send millions of these, do not OOM */
2307                                         cookie = xstrdup(skip_whitespace(iobuf + sizeof("Cookie:")-1));
2308                         } else if (STRNCASECMP(iobuf, "Content-Type:") == 0) {
2309                                 if (!content_type)
2310                                         content_type = xstrdup(skip_whitespace(iobuf + sizeof("Content-Type:")-1));
2311                         } else if (STRNCASECMP(iobuf, "Referer:") == 0) {
2312                                 if (!G.referer)
2313                                         G.referer = xstrdup(skip_whitespace(iobuf + sizeof("Referer:")-1));
2314                         } else if (STRNCASECMP(iobuf, "User-Agent:") == 0) {
2315                                 if (!G.user_agent)
2316                                         G.user_agent = xstrdup(skip_whitespace(iobuf + sizeof("User-Agent:")-1));
2317                         } else if (STRNCASECMP(iobuf, "Host:") == 0) {
2318                                 if (!G.host)
2319                                         G.host = xstrdup(skip_whitespace(iobuf + sizeof("Host:")-1));
2320                         } else if (STRNCASECMP(iobuf, "Accept:") == 0) {
2321                                 if (!G.http_accept)
2322                                         G.http_accept = xstrdup(skip_whitespace(iobuf + sizeof("Accept:")-1));
2323                         } else if (STRNCASECMP(iobuf, "Accept-Language:") == 0) {
2324                                 if (!G.http_accept_language)
2325                                         G.http_accept_language = xstrdup(skip_whitespace(iobuf + sizeof("Accept-Language:")-1));
2326                         }
2327 #endif
2328 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
2329                         if (STRNCASECMP(iobuf, "Authorization:") == 0) {
2330                                 /* We only allow Basic credentials.
2331                                  * It shows up as "Authorization: Basic <user>:<passwd>" where
2332                                  * "<user>:<passwd>" is base64 encoded.
2333                                  */
2334                                 tptr = skip_whitespace(iobuf + sizeof("Authorization:")-1);
2335                                 if (STRNCASECMP(tptr, "Basic") != 0)
2336                                         continue;
2337                                 tptr += sizeof("Basic")-1;
2338                                 /* decodeBase64() skips whitespace itself */
2339                                 decodeBase64(tptr);
2340                                 authorized = check_user_passwd(urlcopy, tptr);
2341                         }
2342 #endif
2343 #if ENABLE_FEATURE_HTTPD_RANGES
2344                         if (STRNCASECMP(iobuf, "Range:") == 0) {
2345                                 /* We know only bytes=NNN-[MMM] */
2346                                 char *s = skip_whitespace(iobuf + sizeof("Range:")-1);
2347                                 if (is_prefixed_with(s, "bytes=")) {
2348                                         s += sizeof("bytes=")-1;
2349                                         range_start = BB_STRTOOFF(s, &s, 10);
2350                                         if (s[0] != '-' || range_start < 0) {
2351                                                 range_start = -1;
2352                                         } else if (s[1]) {
2353                                                 range_end = BB_STRTOOFF(s+1, NULL, 10);
2354                                                 if (errno || range_end < range_start)
2355                                                         range_start = -1;
2356                                         }
2357                                 }
2358                         }
2359 #endif
2360 #if ENABLE_FEATURE_HTTPD_GZIP
2361                         if (STRNCASECMP(iobuf, "Accept-Encoding:") == 0) {
2362                                 /* Note: we do not support "gzip;q=0"
2363                                  * method of _disabling_ gzip
2364                                  * delivery. No one uses that, though */
2365                                 const char *s = strstr(iobuf, "gzip");
2366                                 if (s) {
2367                                         // want more thorough checks?
2368                                         //if (s[-1] == ' '
2369                                         // || s[-1] == ','
2370                                         // || s[-1] == ':'
2371                                         //) {
2372                                                 content_gzip = 1;
2373                                         //}
2374                                 }
2375                         }
2376 #endif
2377                 } /* while extra header reading */
2378         }
2379
2380         /* We are done reading headers, disable peer timeout */
2381         alarm(0);
2382
2383         if (strcmp(bb_basename(urlcopy), HTTPD_CONF) == 0 || !ip_allowed) {
2384                 /* protect listing [/path]/httpd.conf or IP deny */
2385                 send_headers_and_exit(HTTP_FORBIDDEN);
2386         }
2387
2388 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
2389         /* Case: no "Authorization:" was seen, but page might require passwd.
2390          * Check that with dummy user:pass */
2391         if (authorized < 0)
2392                 authorized = check_user_passwd(urlcopy, (char *) "");
2393         if (!authorized)
2394                 send_headers_and_exit(HTTP_UNAUTHORIZED);
2395 #endif
2396
2397         if (found_moved_temporarily) {
2398                 send_headers_and_exit(HTTP_MOVED_TEMPORARILY);
2399         }
2400
2401 #if ENABLE_FEATURE_HTTPD_PROXY
2402         if (proxy_entry != NULL) {
2403                 int proxy_fd;
2404                 len_and_sockaddr *lsa;
2405
2406                 lsa = host2sockaddr(proxy_entry->host_port, 80);
2407                 if (lsa == NULL)
2408                         send_headers_and_exit(HTTP_INTERNAL_SERVER_ERROR);
2409                 proxy_fd = socket(lsa->u.sa.sa_family, SOCK_STREAM, 0);
2410                 if (proxy_fd < 0)
2411                         send_headers_and_exit(HTTP_INTERNAL_SERVER_ERROR);
2412                 if (connect(proxy_fd, &lsa->u.sa, lsa->len) < 0)
2413                         send_headers_and_exit(HTTP_INTERNAL_SERVER_ERROR);
2414                 fdprintf(proxy_fd, "%s %s%s%s%s HTTP/%c.%c\r\n",
2415                                 prequest, /* GET or POST */
2416                                 proxy_entry->url_to, /* url part 1 */
2417                                 urlcopy + strlen(proxy_entry->url_from), /* url part 2 */
2418                                 (g_query ? "?" : ""), /* "?" (maybe) */
2419                                 (g_query ? g_query : ""), /* query string (maybe) */
2420                                 http_major_version, http_minor_version);
2421                 header_ptr[0] = '\r';
2422                 header_ptr[1] = '\n';
2423                 header_ptr += 2;
2424                 write(proxy_fd, header_buf, header_ptr - header_buf);
2425                 free(header_buf); /* on the order of 8k, free it */
2426                 cgi_io_loop_and_exit(proxy_fd, proxy_fd, length);
2427         }
2428 #endif
2429
2430         tptr = urlcopy + 1;      /* skip first '/' */
2431
2432 #if ENABLE_FEATURE_HTTPD_CGI
2433         if (is_prefixed_with(tptr, "cgi-bin/")) {
2434                 if (tptr[8] == '\0') {
2435                         /* protect listing "cgi-bin/" */
2436                         send_headers_and_exit(HTTP_FORBIDDEN);
2437                 }
2438                 send_cgi_and_exit(urlcopy, urlcopy, prequest, length, cookie, content_type);
2439         }
2440 #endif
2441
2442         if (urlp[-1] == '/') {
2443                 /* When index_page string is appended to <dir>/ URL, it overwrites
2444                  * the query string. If we fall back to call /cgi-bin/index.cgi,
2445                  * query string would be lost and not available to the CGI.
2446                  * Work around it by making a deep copy.
2447                  */
2448                 if (ENABLE_FEATURE_HTTPD_CGI)
2449                         g_query = xstrdup(g_query); /* ok for NULL too */
2450                 strcpy(urlp, index_page);
2451         }
2452         if (stat(tptr, &sb) == 0) {
2453 #if ENABLE_FEATURE_HTTPD_CONFIG_WITH_SCRIPT_INTERPR
2454                 char *suffix = strrchr(tptr, '.');
2455                 if (suffix) {
2456                         Htaccess *cur;
2457                         for (cur = script_i; cur; cur = cur->next) {
2458                                 if (strcmp(cur->before_colon + 1, suffix) == 0) {
2459                                         send_cgi_and_exit(urlcopy, urlcopy, prequest, length, cookie, content_type);
2460                                 }
2461                         }
2462                 }
2463 #endif
2464                 file_size = sb.st_size;
2465                 last_mod = sb.st_mtime;
2466         }
2467 #if ENABLE_FEATURE_HTTPD_CGI
2468         else if (urlp[-1] == '/') {
2469                 /* It's a dir URL and there is no index.html
2470                  * Try cgi-bin/index.cgi */
2471                 if (access("/cgi-bin/index.cgi"+1, X_OK) == 0) {
2472                         urlp[0] = '\0'; /* remove index_page */
2473                         send_cgi_and_exit("/cgi-bin/index.cgi", urlcopy, prequest, length, cookie, content_type);
2474                 }
2475         }
2476         /* else fall through to send_file, it errors out if open fails: */
2477
2478         if (prequest != request_GET && prequest != request_HEAD) {
2479                 /* POST for files does not make sense */
2480                 send_headers_and_exit(HTTP_NOT_IMPLEMENTED);
2481         }
2482         send_file_and_exit(tptr,
2483                 (prequest != request_HEAD ? SEND_HEADERS_AND_BODY : SEND_HEADERS)
2484         );
2485 #else
2486         send_file_and_exit(tptr, SEND_HEADERS_AND_BODY);
2487 #endif
2488 }
2489
2490 /*
2491  * The main http server function.
2492  * Given a socket, listen for new connections and farm out
2493  * the processing as a [v]forked process.
2494  * Never returns.
2495  */
2496 #if BB_MMU
2497 static void mini_httpd(int server_socket) NORETURN;
2498 static void mini_httpd(int server_socket)
2499 {
2500         /* NB: it's best to not use xfuncs in this loop before fork().
2501          * Otherwise server may die on transient errors (temporary
2502          * out-of-memory condition, etc), which is Bad(tm).
2503          * Try to do any dangerous calls after fork.
2504          */
2505         while (1) {
2506                 int n;
2507                 len_and_sockaddr fromAddr;
2508
2509                 /* Wait for connections... */
2510                 fromAddr.len = LSA_SIZEOF_SA;
2511                 n = accept(server_socket, &fromAddr.u.sa, &fromAddr.len);
2512                 if (n < 0)
2513                         continue;
2514
2515                 /* set the KEEPALIVE option to cull dead connections */
2516                 setsockopt_keepalive(n);
2517
2518                 if (fork() == 0) {
2519                         /* child */
2520                         /* Do not reload config on HUP */
2521                         signal(SIGHUP, SIG_IGN);
2522                         close(server_socket);
2523                         xmove_fd(n, 0);
2524                         xdup2(0, 1);
2525
2526                         handle_incoming_and_exit(&fromAddr);
2527                 }
2528                 /* parent, or fork failed */
2529                 close(n);
2530         } /* while (1) */
2531         /* never reached */
2532 }
2533 #else
2534 static void mini_httpd_nommu(int server_socket, int argc, char **argv) NORETURN;
2535 static void mini_httpd_nommu(int server_socket, int argc, char **argv)
2536 {
2537         char *argv_copy[argc + 2];
2538
2539         argv_copy[0] = argv[0];
2540         argv_copy[1] = (char*)"-i";
2541         memcpy(&argv_copy[2], &argv[1], argc * sizeof(argv[0]));
2542
2543         /* NB: it's best to not use xfuncs in this loop before vfork().
2544          * Otherwise server may die on transient errors (temporary
2545          * out-of-memory condition, etc), which is Bad(tm).
2546          * Try to do any dangerous calls after fork.
2547          */
2548         while (1) {
2549                 int n;
2550
2551                 /* Wait for connections... */
2552                 n = accept(server_socket, NULL, NULL);
2553                 if (n < 0)
2554                         continue;
2555
2556                 /* set the KEEPALIVE option to cull dead connections */
2557                 setsockopt_keepalive(n);
2558
2559                 if (vfork() == 0) {
2560                         /* child */
2561                         /* Do not reload config on HUP */
2562                         signal(SIGHUP, SIG_IGN);
2563                         close(server_socket);
2564                         xmove_fd(n, 0);
2565                         xdup2(0, 1);
2566
2567                         /* Run a copy of ourself in inetd mode */
2568                         re_exec(argv_copy);
2569                 }
2570                 argv_copy[0][0] &= 0x7f;
2571                 /* parent, or vfork failed */
2572                 close(n);
2573         } /* while (1) */
2574         /* never reached */
2575 }
2576 #endif
2577
2578 /*
2579  * Process a HTTP connection on stdin/out.
2580  * Never returns.
2581  */
2582 static void mini_httpd_inetd(void) NORETURN;
2583 static void mini_httpd_inetd(void)
2584 {
2585         len_and_sockaddr fromAddr;
2586
2587         memset(&fromAddr, 0, sizeof(fromAddr));
2588         fromAddr.len = LSA_SIZEOF_SA;
2589         /* NB: can fail if user runs it by hand and types in http cmds */
2590         getpeername(0, &fromAddr.u.sa, &fromAddr.len);
2591         handle_incoming_and_exit(&fromAddr);
2592 }
2593
2594 static void sighup_handler(int sig UNUSED_PARAM)
2595 {
2596         parse_conf(DEFAULT_PATH_HTTPD_CONF, SIGNALED_PARSE);
2597 }
2598
2599 enum {
2600         c_opt_config_file = 0,
2601         d_opt_decode_url,
2602         h_opt_home_httpd,
2603         IF_FEATURE_HTTPD_ENCODE_URL_STR(e_opt_encode_url,)
2604         IF_FEATURE_HTTPD_BASIC_AUTH(    r_opt_realm     ,)
2605         IF_FEATURE_HTTPD_AUTH_MD5(      m_opt_md5       ,)
2606         IF_FEATURE_HTTPD_SETUID(        u_opt_setuid    ,)
2607         p_opt_port      ,
2608         p_opt_inetd     ,
2609         p_opt_foreground,
2610         p_opt_verbose   ,
2611         OPT_CONFIG_FILE = 1 << c_opt_config_file,
2612         OPT_DECODE_URL  = 1 << d_opt_decode_url,
2613         OPT_HOME_HTTPD  = 1 << h_opt_home_httpd,
2614         OPT_ENCODE_URL  = IF_FEATURE_HTTPD_ENCODE_URL_STR((1 << e_opt_encode_url)) + 0,
2615         OPT_REALM       = IF_FEATURE_HTTPD_BASIC_AUTH(    (1 << r_opt_realm     )) + 0,
2616         OPT_MD5         = IF_FEATURE_HTTPD_AUTH_MD5(      (1 << m_opt_md5       )) + 0,
2617         OPT_SETUID      = IF_FEATURE_HTTPD_SETUID(        (1 << u_opt_setuid    )) + 0,
2618         OPT_PORT        = 1 << p_opt_port,
2619         OPT_INETD       = 1 << p_opt_inetd,
2620         OPT_FOREGROUND  = 1 << p_opt_foreground,
2621         OPT_VERBOSE     = 1 << p_opt_verbose,
2622 };
2623
2624
2625 int httpd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
2626 int httpd_main(int argc UNUSED_PARAM, char **argv)
2627 {
2628         int server_socket = server_socket; /* for gcc */
2629         unsigned opt;
2630         char *url_for_decode;
2631         IF_FEATURE_HTTPD_ENCODE_URL_STR(const char *url_for_encode;)
2632         IF_FEATURE_HTTPD_SETUID(const char *s_ugid = NULL;)
2633         IF_FEATURE_HTTPD_SETUID(struct bb_uidgid_t ugid;)
2634         IF_FEATURE_HTTPD_AUTH_MD5(const char *pass;)
2635
2636         INIT_G();
2637
2638 #if ENABLE_LOCALE_SUPPORT
2639         /* Undo busybox.c: we want to speak English in http (dates etc) */
2640         setlocale(LC_TIME, "C");
2641 #endif
2642
2643         home_httpd = xrealloc_getcwd_or_warn(NULL);
2644         /* We do not "absolutize" path given by -h (home) opt.
2645          * If user gives relative path in -h,
2646          * $SCRIPT_FILENAME will not be set. */
2647         opt = getopt32(argv, "^"
2648                         "c:d:h:"
2649                         IF_FEATURE_HTTPD_ENCODE_URL_STR("e:")
2650                         IF_FEATURE_HTTPD_BASIC_AUTH("r:")
2651                         IF_FEATURE_HTTPD_AUTH_MD5("m:")
2652                         IF_FEATURE_HTTPD_SETUID("u:")
2653                         "p:ifv"
2654                         "\0"
2655                         /* -v counts, -i implies -f */
2656                         "vv:if",
2657                         &opt_c_configFile, &url_for_decode, &home_httpd
2658                         IF_FEATURE_HTTPD_ENCODE_URL_STR(, &url_for_encode)
2659                         IF_FEATURE_HTTPD_BASIC_AUTH(, &g_realm)
2660                         IF_FEATURE_HTTPD_AUTH_MD5(, &pass)
2661                         IF_FEATURE_HTTPD_SETUID(, &s_ugid)
2662                         , &bind_addr_or_port
2663                         , &verbose
2664                 );
2665         if (opt & OPT_DECODE_URL) {
2666                 fputs(percent_decode_in_place(url_for_decode, /*strict:*/ 0), stdout);
2667                 return 0;
2668         }
2669 #if ENABLE_FEATURE_HTTPD_ENCODE_URL_STR
2670         if (opt & OPT_ENCODE_URL) {
2671                 fputs(encodeString(url_for_encode), stdout);
2672                 return 0;
2673         }
2674 #endif
2675 #if ENABLE_FEATURE_HTTPD_AUTH_MD5
2676         if (opt & OPT_MD5) {
2677                 char salt[sizeof("$1$XXXXXXXX")];
2678                 salt[0] = '$';
2679                 salt[1] = '1';
2680                 salt[2] = '$';
2681                 crypt_make_salt(salt + 3, 4);
2682                 puts(pw_encrypt(pass, salt, /*cleanup:*/ 0));
2683                 return 0;
2684         }
2685 #endif
2686 #if ENABLE_FEATURE_HTTPD_SETUID
2687         if (opt & OPT_SETUID) {
2688                 xget_uidgid(&ugid, s_ugid);
2689         }
2690 #endif
2691
2692 #if !BB_MMU
2693         if (!(opt & OPT_FOREGROUND)) {
2694                 bb_daemonize_or_rexec(0, argv); /* don't change current directory */
2695         }
2696 #endif
2697
2698         xchdir(home_httpd);
2699         if (!(opt & OPT_INETD)) {
2700                 signal(SIGCHLD, SIG_IGN);
2701                 server_socket = openServer();
2702 #if ENABLE_FEATURE_HTTPD_SETUID
2703                 /* drop privileges */
2704                 if (opt & OPT_SETUID) {
2705                         if (ugid.gid != (gid_t)-1) {
2706                                 if (setgroups(1, &ugid.gid) == -1)
2707                                         bb_perror_msg_and_die("setgroups");
2708                                 xsetgid(ugid.gid);
2709                         }
2710                         xsetuid(ugid.uid);
2711                 }
2712 #endif
2713         }
2714
2715 #if 0
2716         /* User can do it himself: 'env - PATH="$PATH" httpd'
2717          * We don't do it because we don't want to screw users
2718          * which want to do
2719          * 'env - VAR1=val1 VAR2=val2 httpd'
2720          * and have VAR1 and VAR2 values visible in their CGIs.
2721          * Besides, it is also smaller. */
2722         {
2723                 char *p = getenv("PATH");
2724                 /* env strings themself are not freed, no need to xstrdup(p): */
2725                 clearenv();
2726                 if (p)
2727                         putenv(p - 5);
2728 //              if (!(opt & OPT_INETD))
2729 //                      setenv_long("SERVER_PORT", ???);
2730         }
2731 #endif
2732
2733         parse_conf(DEFAULT_PATH_HTTPD_CONF, FIRST_PARSE);
2734         if (!(opt & OPT_INETD))
2735                 signal(SIGHUP, sighup_handler);
2736
2737         xfunc_error_retval = 0;
2738         if (opt & OPT_INETD)
2739                 mini_httpd_inetd(); /* never returns */
2740 #if BB_MMU
2741         if (!(opt & OPT_FOREGROUND))
2742                 bb_daemonize(0); /* don't change current directory */
2743         mini_httpd(server_socket); /* never returns */
2744 #else
2745         mini_httpd_nommu(server_socket, argc, argv); /* never returns */
2746 #endif
2747         /* return 0; */
2748 }