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 //config:config HTTPD
 100 //config:       bool "httpd (32 kb)"
 101 //config:       default y
 102 //config:       help
 103 //config:       HTTP server.
 104 //config:
 105 //config:config FEATURE_HTTPD_RANGES
 106 //config:       bool "Support 'Ranges:' header"
 107 //config:       default y
 108 //config:       depends on HTTPD
 109 //config:       help
 110 //config:       Makes httpd emit "Accept-Ranges: bytes" header and understand
 111 //config:       "Range: bytes=NNN-[MMM]" header. Allows for resuming interrupted
 112 //config:       downloads, seeking in multimedia players etc.
 113 //config:
 114 //config:config FEATURE_HTTPD_SETUID
 115 //config:       bool "Enable -u <user> option"
 116 //config:       default y
 117 //config:       depends on HTTPD
 118 //config:       help
 119 //config:       This option allows the server to run as a specific user
 120 //config:       rather than defaulting to the user that starts the server.
 121 //config:       Use of this option requires special privileges to change to a
 122 //config:       different user.
 123 //config:
 124 //config:config FEATURE_HTTPD_BASIC_AUTH
 125 //config:       bool "Enable HTTP authentication"
 126 //config:       default y
 127 //config:       depends on HTTPD
 128 //config:       help
 129 //config:       Utilizes password settings from /etc/httpd.conf for basic
 130 //config:       authentication on a per url basis.
 131 //config:       Example for httpd.conf file:
 132 //config:       /adm:toor:PaSsWd
 133 //config:
 134 //config:config FEATURE_HTTPD_AUTH_MD5
 135 //config:       bool "Support MD5-encrypted passwords in HTTP authentication"
 136 //config:       default y
 137 //config:       depends on FEATURE_HTTPD_BASIC_AUTH
 138 //config:       help
 139 //config:       Enables encrypted passwords, and wildcard user/passwords
 140 //config:       in httpd.conf file.
 141 //config:       User '*' means 'any system user name is ok',
 142 //config:       password of '*' means 'use system password for this user'
 143 //config:       Examples:
 144 //config:       /adm:toor:$1$P/eKnWXS$aI1aPGxT.dJD5SzqAKWrF0
 145 //config:       /adm:root:*
 146 //config:       /wiki:*:*
 147 //config:
 148 //config:config FEATURE_HTTPD_CGI
 149 //config:       bool "Support Common Gateway Interface (CGI)"
 150 //config:       default y
 151 //config:       depends on HTTPD
 152 //config:       help
 153 //config:       This option allows scripts and executables to be invoked
 154 //config:       when specific URLs are requested.
 155 //config:
 156 //config:config FEATURE_HTTPD_CONFIG_WITH_SCRIPT_INTERPR
 157 //config:       bool "Support running scripts through an interpreter"
 158 //config:       default y
 159 //config:       depends on FEATURE_HTTPD_CGI
 160 //config:       help
 161 //config:       This option enables support for running scripts through an
 162 //config:       interpreter. Turn this on if you want PHP scripts to work
 163 //config:       properly. You need to supply an additional line in your
 164 //config:       httpd.conf file:
 165 //config:       *.php:/path/to/your/php
 166 //config:
 167 //config:config FEATURE_HTTPD_SET_REMOTE_PORT_TO_ENV
 168 //config:       bool "Set REMOTE_PORT environment variable for CGI"
 169 //config:       default y
 170 //config:       depends on FEATURE_HTTPD_CGI
 171 //config:       help
 172 //config:       Use of this option can assist scripts in generating
 173 //config:       references that contain a unique port number.
 174 //config:
 175 //config:config FEATURE_HTTPD_ENCODE_URL_STR
 176 //config:       bool "Enable -e option (useful for CGIs written as shell scripts)"
 177 //config:       default y
 178 //config:       depends on HTTPD
 179 //config:       help
 180 //config:       This option allows html encoding of arbitrary strings for display
 181 //config:       by the browser. Output goes to stdout.
 182 //config:       For example, httpd -e "<Hello World>" produces
 183 //config:       "&#60Hello&#32World&#62".
 184 //config:
 185 //config:config FEATURE_HTTPD_ERROR_PAGES
 186 //config:       bool "Support custom error pages"
 187 //config:       default y
 188 //config:       depends on HTTPD
 189 //config:       help
 190 //config:       This option allows you to define custom error pages in
 191 //config:       the configuration file instead of the default HTTP status
 192 //config:       error pages. For instance, if you add the line:
 193 //config:               E404:/path/e404.html
 194 //config:       in the config file, the server will respond the specified
 195 //config:       '/path/e404.html' file instead of the terse '404 NOT FOUND'
 196 //config:       message.
 197 //config:
 198 //config:config FEATURE_HTTPD_PROXY
 199 //config:       bool "Support reverse proxy"
 200 //config:       default y
 201 //config:       depends on HTTPD
 202 //config:       help
 203 //config:       This option allows you to define URLs that will be forwarded
 204 //config:       to another HTTP server. To setup add the following line to the
 205 //config:       configuration file
 206 //config:               P:/url/:http://hostname[:port]/new/path/
 207 //config:       Then a request to /url/myfile will be forwarded to
 208 //config:       http://hostname[:port]/new/path/myfile.
 209 //config:
 210 //config:config FEATURE_HTTPD_GZIP
 211 //config:       bool "Support GZIP content encoding"
 212 //config:       default y
 213 //config:       depends on HTTPD
 214 //config:       help
 215 //config:       Makes httpd send files using GZIP content encoding if the
 216 //config:       client supports it and a pre-compressed <file>.gz exists.
 217
 218 //applet:IF_HTTPD(APPLET(httpd, BB_DIR_USR_SBIN, BB_SUID_DROP))
 219
 220 //kbuild:lib-$(CONFIG_HTTPD) += httpd.o
 221
 222 //usage:#define httpd_trivial_usage
 223 //usage:       "[-ifv[v]]"
 224 //usage:       " [-c CONFFILE]"
 225 //usage:       " [-p [IP:]PORT]"
 226 //usage:        IF_FEATURE_HTTPD_SETUID(" [-u USER[:GRP]]")
 227 //usage:        IF_FEATURE_HTTPD_BASIC_AUTH(" [-r REALM]")
 228 //usage:       " [-h HOME]\n"
 229 //usage:       "or httpd -d/-e" IF_FEATURE_HTTPD_AUTH_MD5("/-m") " STRING"
 230 //usage:#define httpd_full_usage "\n\n"
 231 //usage:       "Listen for incoming HTTP requests\n"
 232 //usage:     "\n        -i              Inetd mode"
 233 //usage:     "\n        -f              Don't daemonize"
 234 //usage:     "\n        -v[v]           Verbose"
 235 //usage:     "\n        -p [IP:]PORT    Bind to IP:PORT (default *:80)"
 236 //usage:        IF_FEATURE_HTTPD_SETUID(
 237 //usage:     "\n        -u USER[:GRP]   Set uid/gid after binding to port")
 238 //usage:        IF_FEATURE_HTTPD_BASIC_AUTH(
 239 //usage:     "\n        -r REALM        Authentication Realm for Basic Authentication")
 240 //usage:     "\n        -h HOME         Home directory (default .)"
 241 //usage:     "\n        -c FILE         Configuration file (default {/etc,HOME}/httpd.conf)"
 242 //usage:        IF_FEATURE_HTTPD_AUTH_MD5(
 243 //usage:     "\n        -m STRING       MD5 crypt STRING")
 244 //usage:     "\n        -e STRING       HTML encode STRING"
 245 //usage:     "\n        -d STRING       URL decode STRING"
 246
 247 /* TODO: use TCP_CORK, parse_config() */
 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.
1198  * '\r' chars are removed.
1199  * '\n' is replaced with NUL.
1200  * Return number of characters read or 0 if nothing is read
1201  * ('\r' and '\n' are not counted).
1202  * Data is returned in iobuf.
1203  */
1204 static int get_line(void)
1205 {
1206         int count;
1207         char c;
1208
1209         alarm(HEADER_READ_TIMEOUT);
1210         count = 0;
1211         while (1) {
1212                 if (hdr_cnt <= 0) {
1213                         hdr_cnt = safe_read(STDIN_FILENO, hdr_buf, sizeof_hdr_buf);
1214                         if (hdr_cnt <= 0)
1215                                 goto ret;
1216                         hdr_ptr = hdr_buf;
1217                 }
1218                 hdr_cnt--;
1219                 c = *hdr_ptr++;
1220                 if (c == '\r')
1221                         continue;
1222                 if (c == '\n')
1223                         break;
1224                 iobuf[count] = c;
1225                 if (count < (IOBUF_SIZE - 1))      /* check overflow */
1226                         count++;
1227         }
1228  ret:
1229         iobuf[count] = '\0';
1230         return count;
1231 }
1232
1233 #if ENABLE_FEATURE_HTTPD_CGI || ENABLE_FEATURE_HTTPD_PROXY
1234
1235 /* gcc 4.2.1 fares better with NOINLINE */
1236 static NOINLINE void cgi_io_loop_and_exit(int fromCgi_rd, int toCgi_wr, int post_len) NORETURN;
1237 static NOINLINE void cgi_io_loop_and_exit(int fromCgi_rd, int toCgi_wr, int post_len)
1238 {
1239         enum { FROM_CGI = 1, TO_CGI = 2 }; /* indexes in pfd[] */
1240         struct pollfd pfd[3];
1241         int out_cnt; /* we buffer a bit of initial CGI output */
1242         int count;
1243
1244         /* iobuf is used for CGI -> network data,
1245          * hdr_buf is for network -> CGI data (POSTDATA) */
1246
1247         /* If CGI dies, we still want to correctly finish reading its output
1248          * and send it to the peer. So please no SIGPIPEs! */
1249         signal(SIGPIPE, SIG_IGN);
1250
1251         // We inconsistently handle a case when more POSTDATA from network
1252         // is coming than we expected. We may give *some part* of that
1253         // extra data to CGI.
1254
1255         //if (hdr_cnt > post_len) {
1256         //      /* We got more POSTDATA from network than we expected */
1257         //      hdr_cnt = post_len;
1258         //}
1259         post_len -= hdr_cnt;
1260         /* post_len - number of POST bytes not yet read from network */
1261
1262         /* NB: breaking out of this loop jumps to log_and_exit() */
1263         out_cnt = 0;
1264         pfd[FROM_CGI].fd = fromCgi_rd;
1265         pfd[FROM_CGI].events = POLLIN;
1266         pfd[TO_CGI].fd = toCgi_wr;
1267         while (1) {
1268                 /* Note: even pfd[0].events == 0 won't prevent
1269                  * revents == POLLHUP|POLLERR reports from closed stdin.
1270                  * Setting fd to -1 works: */
1271                 pfd[0].fd = -1;
1272                 pfd[0].events = POLLIN;
1273                 pfd[0].revents = 0; /* probably not needed, paranoia */
1274
1275                 /* We always poll this fd, thus kernel always sets revents: */
1276                 /*pfd[FROM_CGI].events = POLLIN; - moved out of loop */
1277                 /*pfd[FROM_CGI].revents = 0; - not needed */
1278
1279                 /* gcc-4.8.0 still doesnt fill two shorts with one insn :( */
1280                 /* http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47059 */
1281                 /* hopefully one day it will... */
1282                 pfd[TO_CGI].events = POLLOUT;
1283                 pfd[TO_CGI].revents = 0; /* needed! */
1284
1285                 if (toCgi_wr && hdr_cnt <= 0) {
1286                         if (post_len > 0) {
1287                                 /* Expect more POST data from network */
1288                                 pfd[0].fd = 0;
1289                         } else {
1290                                 /* post_len <= 0 && hdr_cnt <= 0:
1291                                  * no more POST data to CGI,
1292                                  * let CGI see EOF on CGI's stdin */
1293                                 if (toCgi_wr != fromCgi_rd)
1294                                         close(toCgi_wr);
1295                                 toCgi_wr = 0;
1296                         }
1297                 }
1298
1299                 /* Now wait on the set of sockets */
1300                 count = safe_poll(pfd, hdr_cnt > 0 ? TO_CGI+1 : FROM_CGI+1, -1);
1301                 if (count <= 0) {
1302 #if 0
1303                         if (safe_waitpid(pid, &status, WNOHANG) <= 0) {
1304                                 /* Weird. CGI didn't exit and no fd's
1305                                  * are ready, yet poll returned?! */
1306                                 continue;
1307                         }
1308                         if (DEBUG && WIFEXITED(status))
1309                                 bb_error_msg("CGI exited, status=%u", WEXITSTATUS(status));
1310                         if (DEBUG && WIFSIGNALED(status))
1311                                 bb_error_msg("CGI killed, signal=%u", WTERMSIG(status));
1312 #endif
1313                         break;
1314                 }
1315
1316                 if (pfd[TO_CGI].revents) {
1317                         /* hdr_cnt > 0 here due to the way poll() called */
1318                         /* Have data from peer and can write to CGI */
1319                         count = safe_write(toCgi_wr, hdr_ptr, hdr_cnt);
1320                         /* Doesn't happen, we dont use nonblocking IO here
1321                          *if (count < 0 && errno == EAGAIN) {
1322                          *      ...
1323                          *} else */
1324                         if (count > 0) {
1325                                 hdr_ptr += count;
1326                                 hdr_cnt -= count;
1327                         } else {
1328                                 /* EOF/broken pipe to CGI, stop piping POST data */
1329                                 hdr_cnt = post_len = 0;
1330                         }
1331                 }
1332
1333                 if (pfd[0].revents) {
1334                         /* post_len > 0 && hdr_cnt == 0 here */
1335                         /* We expect data, prev data portion is eaten by CGI
1336                          * and there *is* data to read from the peer
1337                          * (POSTDATA) */
1338                         //count = post_len > (int)sizeof_hdr_buf ? (int)sizeof_hdr_buf : post_len;
1339                         //count = safe_read(STDIN_FILENO, hdr_buf, count);
1340                         count = safe_read(STDIN_FILENO, hdr_buf, sizeof_hdr_buf);
1341                         if (count > 0) {
1342                                 hdr_cnt = count;
1343                                 hdr_ptr = hdr_buf;
1344                                 post_len -= count;
1345                         } else {
1346                                 /* no more POST data can be read */
1347                                 post_len = 0;
1348                         }
1349                 }
1350
1351                 if (pfd[FROM_CGI].revents) {
1352                         /* There is something to read from CGI */
1353                         char *rbuf = iobuf;
1354
1355                         /* Are we still buffering CGI output? */
1356                         if (out_cnt >= 0) {
1357                                 /* HTTP_200[] has single "\r\n" at the end.
1358                                  * According to http://hoohoo.ncsa.uiuc.edu/cgi/out.html,
1359                                  * CGI scripts MUST send their own header terminated by
1360                                  * empty line, then data. That's why we have only one
1361                                  * <cr><lf> pair here. We will output "200 OK" line
1362                                  * if needed, but CGI still has to provide blank line
1363                                  * between header and body */
1364
1365                                 /* Must use safe_read, not full_read, because
1366                                  * CGI may output a few first bytes and then wait
1367                                  * for POSTDATA without closing stdout.
1368                                  * With full_read we may wait here forever. */
1369                                 count = safe_read(fromCgi_rd, rbuf + out_cnt, PIPE_BUF - 8);
1370                                 if (count <= 0) {
1371                                         /* eof (or error) and there was no "HTTP",
1372                                          * so write it, then write received data */
1373                                         if (out_cnt) {
1374                                                 full_write(STDOUT_FILENO, HTTP_200, sizeof(HTTP_200)-1);
1375                                                 full_write(STDOUT_FILENO, rbuf, out_cnt);
1376                                         }
1377                                         break; /* CGI stdout is closed, exiting */
1378                                 }
1379                                 out_cnt += count;
1380                                 count = 0;
1381                                 /* "Status" header format is: "Status: 302 Redirected\r\n" */
1382                                 if (out_cnt >= 8 && memcmp(rbuf, "Status: ", 8) == 0) {
1383                                         /* send "HTTP/1.0 " */
1384                                         if (full_write(STDOUT_FILENO, HTTP_200, 9) != 9)
1385                                                 break;
1386                                         /* skip "Status: " (including space, sending "HTTP/1.0  NNN" is wrong) */
1387                                         rbuf += 8;
1388                                         count = out_cnt - 8;
1389                                         out_cnt = -1; /* buffering off */
1390                                 } else if (out_cnt >= 4) {
1391                                         /* Did CGI add "HTTP"? */
1392                                         if (memcmp(rbuf, HTTP_200, 4) != 0) {
1393                                                 /* there is no "HTTP", do it ourself */
1394                                                 if (full_write(STDOUT_FILENO, HTTP_200, sizeof(HTTP_200)-1) != sizeof(HTTP_200)-1)
1395                                                         break;
1396                                         }
1397                                         /* Commented out:
1398                                         if (!strstr(rbuf, "ontent-")) {
1399                                                 full_write(s, "Content-type: text/plain\r\n\r\n", 28);
1400                                         }
1401                                          * Counter-example of valid CGI without Content-type:
1402                                          * echo -en "HTTP/1.0 302 Found\r\n"
1403                                          * echo -en "Location: http://www.busybox.net\r\n"
1404                                          * echo -en "\r\n"
1405                                          */
1406                                         count = out_cnt;
1407                                         out_cnt = -1; /* buffering off */
1408                                 }
1409                         } else {
1410                                 count = safe_read(fromCgi_rd, rbuf, PIPE_BUF);
1411                                 if (count <= 0)
1412                                         break;  /* eof (or error) */
1413                         }
1414                         if (full_write(STDOUT_FILENO, rbuf, count) != count)
1415                                 break;
1416                         if (DEBUG)
1417                                 fprintf(stderr, "cgi read %d bytes: '%.*s'\n", count, count, rbuf);
1418                 } /* if (pfd[FROM_CGI].revents) */
1419         } /* while (1) */
1420         log_and_exit();
1421 }
1422 #endif
1423
1424 #if ENABLE_FEATURE_HTTPD_CGI
1425
1426 static void setenv1(const char *name, const char *value)
1427 {
1428         setenv(name, value ? value : "", 1);
1429 }
1430
1431 /*
1432  * Spawn CGI script, forward CGI's stdin/out <=> network
1433  *
1434  * Environment variables are set up and the script is invoked with pipes
1435  * for stdin/stdout.  If a POST is being done the script is fed the POST
1436  * data in addition to setting the QUERY_STRING variable (for GETs or POSTs).
1437  *
1438  * Parameters:
1439  * const char *url              The requested URL (with leading /).
1440  * const char *orig_uri         The original URI before rewriting (if any)
1441  * int post_len                 Length of the POST body.
1442  * const char *cookie           For set HTTP_COOKIE.
1443  * const char *content_type     For set CONTENT_TYPE.
1444  */
1445 static void send_cgi_and_exit(
1446                 const char *url,
1447                 const char *orig_uri,
1448                 const char *request,
1449                 int post_len,
1450                 const char *cookie,
1451                 const char *content_type) NORETURN;
1452 static void send_cgi_and_exit(
1453                 const char *url,
1454                 const char *orig_uri,
1455                 const char *request,
1456                 int post_len,
1457                 const char *cookie,
1458                 const char *content_type)
1459 {
1460         struct fd_pair fromCgi;  /* CGI -> httpd pipe */
1461         struct fd_pair toCgi;    /* httpd -> CGI pipe */
1462         char *script, *last_slash;
1463         int pid;
1464
1465         /* Make a copy. NB: caller guarantees:
1466          * url[0] == '/', url[1] != '/' */
1467         url = xstrdup(url);
1468
1469         /*
1470          * We are mucking with environment _first_ and then vfork/exec,
1471          * this allows us to use vfork safely. Parent doesn't care about
1472          * these environment changes anyway.
1473          */
1474
1475         /* Check for [dirs/]script.cgi/PATH_INFO */
1476         last_slash = script = (char*)url;
1477         while ((script = strchr(script + 1, '/')) != NULL) {
1478                 int dir;
1479                 *script = '\0';
1480                 dir = is_directory(url + 1, /*followlinks:*/ 1);
1481                 *script = '/';
1482                 if (!dir) {
1483                         /* not directory, found script.cgi/PATH_INFO */
1484                         break;
1485                 }
1486                 /* is directory, find next '/' */
1487                 last_slash = script;
1488         }
1489         setenv1("PATH_INFO", script);   /* set to /PATH_INFO or "" */
1490         setenv1("REQUEST_METHOD", request);
1491         if (g_query) {
1492                 putenv(xasprintf("%s=%s?%s", "REQUEST_URI", orig_uri, g_query));
1493         } else {
1494                 setenv1("REQUEST_URI", orig_uri);
1495         }
1496         if (script != NULL)
1497                 *script = '\0';         /* cut off /PATH_INFO */
1498
1499         /* SCRIPT_FILENAME is required by PHP in CGI mode */
1500         if (home_httpd[0] == '/') {
1501                 char *fullpath = concat_path_file(home_httpd, url);
1502                 setenv1("SCRIPT_FILENAME", fullpath);
1503         }
1504         /* set SCRIPT_NAME as full path: /cgi-bin/dirs/script.cgi */
1505         setenv1("SCRIPT_NAME", url);
1506         /* http://hoohoo.ncsa.uiuc.edu/cgi/env.html:
1507          * QUERY_STRING: The information which follows the ? in the URL
1508          * which referenced this script. This is the query information.
1509          * It should not be decoded in any fashion. This variable
1510          * should always be set when there is query information,
1511          * regardless of command line decoding. */
1512         /* (Older versions of bbox seem to do some decoding) */
1513         setenv1("QUERY_STRING", g_query);
1514         putenv((char*)"SERVER_SOFTWARE=busybox httpd/"BB_VER);
1515         putenv((char*)"SERVER_PROTOCOL=HTTP/1.0");
1516         putenv((char*)"GATEWAY_INTERFACE=CGI/1.1");
1517         /* Having _separate_ variables for IP and port defeats
1518          * the purpose of having socket abstraction. Which "port"
1519          * are you using on Unix domain socket?
1520          * IOW - REMOTE_PEER="1.2.3.4:56" makes much more sense.
1521          * Oh well... */
1522         {
1523                 char *p = rmt_ip_str ? rmt_ip_str : (char*)"";
1524                 char *cp = strrchr(p, ':');
1525                 if (ENABLE_FEATURE_IPV6 && cp && strchr(cp, ']'))
1526                         cp = NULL;
1527                 if (cp) *cp = '\0'; /* delete :PORT */
1528                 setenv1("REMOTE_ADDR", p);
1529                 if (cp) {
1530                         *cp = ':';
1531 #if ENABLE_FEATURE_HTTPD_SET_REMOTE_PORT_TO_ENV
1532                         setenv1("REMOTE_PORT", cp + 1);
1533 #endif
1534                 }
1535         }
1536         setenv1("HTTP_USER_AGENT", G.user_agent);
1537         if (G.http_accept)
1538                 setenv1("HTTP_ACCEPT", G.http_accept);
1539         if (G.http_accept_language)
1540                 setenv1("HTTP_ACCEPT_LANGUAGE", G.http_accept_language);
1541         if (post_len)
1542                 putenv(xasprintf("CONTENT_LENGTH=%u", post_len));
1543         if (cookie)
1544                 setenv1("HTTP_COOKIE", cookie);
1545         if (content_type)
1546                 setenv1("CONTENT_TYPE", content_type);
1547 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
1548         if (remoteuser) {
1549                 setenv1("REMOTE_USER", remoteuser);
1550                 putenv((char*)"AUTH_TYPE=Basic");
1551         }
1552 #endif
1553         if (G.referer)
1554                 setenv1("HTTP_REFERER", G.referer);
1555         setenv1("HTTP_HOST", G.host); /* set to "" if NULL */
1556         /* setenv1("SERVER_NAME", safe_gethostname()); - don't do this,
1557          * just run "env SERVER_NAME=xyz httpd ..." instead */
1558
1559         xpiped_pair(fromCgi);
1560         xpiped_pair(toCgi);
1561
1562         pid = vfork();
1563         if (pid < 0) {
1564                 /* TODO: log perror? */
1565                 log_and_exit();
1566         }
1567
1568         if (pid == 0) {
1569                 /* Child process */
1570                 char *argv[3];
1571
1572                 xfunc_error_retval = 242;
1573
1574                 /* NB: close _first_, then move fds! */
1575                 close(toCgi.wr);
1576                 close(fromCgi.rd);
1577                 xmove_fd(toCgi.rd, 0);  /* replace stdin with the pipe */
1578                 xmove_fd(fromCgi.wr, 1);  /* replace stdout with the pipe */
1579                 /* User seeing stderr output can be a security problem.
1580                  * If CGI really wants that, it can always do dup itself. */
1581                 /* dup2(1, 2); */
1582
1583                 /* Chdiring to script's dir */
1584                 script = last_slash;
1585                 if (script != url) { /* paranoia */
1586                         *script = '\0';
1587                         if (chdir(url + 1) != 0) {
1588                                 bb_perror_msg("can't change directory to '%s'", url + 1);
1589                                 goto error_execing_cgi;
1590                         }
1591                         // not needed: *script = '/';
1592                 }
1593                 script++;
1594
1595                 /* set argv[0] to name without path */
1596                 argv[0] = script;
1597                 argv[1] = NULL;
1598
1599 #if ENABLE_FEATURE_HTTPD_CONFIG_WITH_SCRIPT_INTERPR
1600                 {
1601                         char *suffix = strrchr(script, '.');
1602
1603                         if (suffix) {
1604                                 Htaccess *cur;
1605                                 for (cur = script_i; cur; cur = cur->next) {
1606                                         if (strcmp(cur->before_colon + 1, suffix) == 0) {
1607                                                 /* found interpreter name */
1608                                                 argv[0] = cur->after_colon;
1609                                                 argv[1] = script;
1610                                                 argv[2] = NULL;
1611                                                 break;
1612                                         }
1613                                 }
1614                         }
1615                 }
1616 #endif
1617                 /* restore default signal dispositions for CGI process */
1618                 bb_signals(0
1619                         | (1 << SIGCHLD)
1620                         | (1 << SIGPIPE)
1621                         | (1 << SIGHUP)
1622                         , SIG_DFL);
1623
1624                 /* _NOT_ execvp. We do not search PATH. argv[0] is a filename
1625                  * without any dir components and will only match a file
1626                  * in the current directory */
1627                 execv(argv[0], argv);
1628                 if (verbose)
1629                         bb_perror_msg("can't execute '%s'", argv[0]);
1630  error_execing_cgi:
1631                 /* send to stdout
1632                  * (we are CGI here, our stdout is pumped to the net) */
1633                 send_headers_and_exit(HTTP_NOT_FOUND);
1634         } /* end child */
1635
1636         /* Parent process */
1637
1638         /* Restore variables possibly changed by child */
1639         xfunc_error_retval = 0;
1640
1641         /* Pump data */
1642         close(fromCgi.wr);
1643         close(toCgi.rd);
1644         cgi_io_loop_and_exit(fromCgi.rd, toCgi.wr, post_len);
1645 }
1646
1647 #endif          /* FEATURE_HTTPD_CGI */
1648
1649 /*
1650  * Send a file response to a HTTP request, and exit
1651  *
1652  * Parameters:
1653  * const char *url  The requested URL (with leading /).
1654  * what             What to send (headers/body/both).
1655  */
1656 static NOINLINE void send_file_and_exit(const char *url, int what)
1657 {
1658         char *suffix;
1659         int fd;
1660         ssize_t count;
1661
1662         if (content_gzip) {
1663                 /* does <url>.gz exist? Then use it instead */
1664                 char *gzurl = xasprintf("%s.gz", url);
1665                 fd = open(gzurl, O_RDONLY);
1666                 free(gzurl);
1667                 if (fd != -1) {
1668                         struct stat sb;
1669                         fstat(fd, &sb);
1670                         file_size = sb.st_size;
1671                         last_mod = sb.st_mtime;
1672                 } else {
1673                         IF_FEATURE_HTTPD_GZIP(content_gzip = 0;)
1674                         fd = open(url, O_RDONLY);
1675                 }
1676         } else {
1677                 fd = open(url, O_RDONLY);
1678         }
1679         if (fd < 0) {
1680                 if (DEBUG)
1681                         bb_perror_msg("can't open '%s'", url);
1682                 /* Error pages are sent by using send_file_and_exit(SEND_BODY).
1683                  * IOW: it is unsafe to call send_headers_and_exit
1684                  * if what is SEND_BODY! Can recurse! */
1685                 if (what != SEND_BODY)
1686                         send_headers_and_exit(HTTP_NOT_FOUND);
1687                 log_and_exit();
1688         }
1689         /* If you want to know about EPIPE below
1690          * (happens if you abort downloads from local httpd): */
1691         signal(SIGPIPE, SIG_IGN);
1692
1693         /* If not found, default is to not send "Content-type:" */
1694         /*found_mime_type = NULL; - already is */
1695         suffix = strrchr(url, '.');
1696         if (suffix) {
1697                 static const char suffixTable[] ALIGN1 =
1698                         /* Shorter suffix must be first:
1699                          * ".html.htm" will fail for ".htm"
1700                          */
1701                         ".txt.h.c.cc.cpp\0" "text/plain\0"
1702                         /* .htm line must be after .h line */
1703                         ".htm.html\0" "text/html\0"
1704                         ".jpg.jpeg\0" "image/jpeg\0"
1705                         ".gif\0"      "image/gif\0"
1706                         ".png\0"      "image/png\0"
1707                         /* .css line must be after .c line */
1708                         ".css\0"      "text/css\0"
1709                         ".wav\0"      "audio/wav\0"
1710                         ".avi\0"      "video/x-msvideo\0"
1711                         ".qt.mov\0"   "video/quicktime\0"
1712                         ".mpe.mpeg\0" "video/mpeg\0"
1713                         ".mid.midi\0" "audio/midi\0"
1714                         ".mp3\0"      "audio/mpeg\0"
1715 #if 0  /* unpopular */
1716                         ".au\0"       "audio/basic\0"
1717                         ".pac\0"      "application/x-ns-proxy-autoconfig\0"
1718                         ".vrml.wrl\0" "model/vrml\0"
1719 #endif
1720                         /* compiler adds another "\0" here */
1721                 ;
1722                 Htaccess *cur;
1723
1724                 /* Examine built-in table */
1725                 const char *table = suffixTable;
1726                 const char *table_next;
1727                 for (; *table; table = table_next) {
1728                         const char *try_suffix;
1729                         const char *mime_type;
1730                         mime_type  = table + strlen(table) + 1;
1731                         table_next = mime_type + strlen(mime_type) + 1;
1732                         try_suffix = strstr(table, suffix);
1733                         if (!try_suffix)
1734                                 continue;
1735                         try_suffix += strlen(suffix);
1736                         if (*try_suffix == '\0' || *try_suffix == '.') {
1737                                 found_mime_type = mime_type;
1738                                 break;
1739                         }
1740                         /* Example: strstr(table, ".av") != NULL, but it
1741                          * does not match ".avi" after all and we end up here.
1742                          * The table is arranged so that in this case we know
1743                          * that it can't match anything in the following lines,
1744                          * and we stop the search: */
1745                         break;
1746                 }
1747                 /* ...then user's table */
1748                 for (cur = mime_a; cur; cur = cur->next) {
1749                         if (strcmp(cur->before_colon, suffix) == 0) {
1750                                 found_mime_type = cur->after_colon;
1751                                 break;
1752                         }
1753                 }
1754         }
1755
1756         if (DEBUG)
1757                 bb_error_msg("sending file '%s' content-type: %s",
1758                         url, found_mime_type);
1759
1760 #if ENABLE_FEATURE_HTTPD_RANGES
1761         if (what == SEND_BODY /* err pages and ranges don't mix */
1762          || content_gzip /* we are sending compressed page: can't do ranges */  ///why?
1763         ) {
1764                 range_start = -1;
1765         }
1766         range_len = MAXINT(off_t);
1767         if (range_start >= 0) {
1768                 if (!range_end || range_end > file_size - 1) {
1769                         range_end = file_size - 1;
1770                 }
1771                 if (range_end < range_start
1772                  || lseek(fd, range_start, SEEK_SET) != range_start
1773                 ) {
1774                         lseek(fd, 0, SEEK_SET);
1775                         range_start = -1;
1776                 } else {
1777                         range_len = range_end - range_start + 1;
1778                         send_headers(HTTP_PARTIAL_CONTENT);
1779                         what = SEND_BODY;
1780                 }
1781         }
1782 #endif
1783         if (what & SEND_HEADERS)
1784                 send_headers(HTTP_OK);
1785 #if ENABLE_FEATURE_USE_SENDFILE
1786         {
1787                 off_t offset = range_start;
1788                 while (1) {
1789                         /* sz is rounded down to 64k */
1790                         ssize_t sz = MAXINT(ssize_t) - 0xffff;
1791                         IF_FEATURE_HTTPD_RANGES(if (sz > range_len) sz = range_len;)
1792                         count = sendfile(STDOUT_FILENO, fd, &offset, sz);
1793                         if (count < 0) {
1794                                 if (offset == range_start)
1795                                         break; /* fall back to read/write loop */
1796                                 goto fin;
1797                         }
1798                         IF_FEATURE_HTTPD_RANGES(range_len -= count;)
1799                         if (count == 0 || range_len == 0)
1800                                 log_and_exit();
1801                 }
1802         }
1803 #endif
1804         while ((count = safe_read(fd, iobuf, IOBUF_SIZE)) > 0) {
1805                 ssize_t n;
1806                 IF_FEATURE_HTTPD_RANGES(if (count > range_len) count = range_len;)
1807                 n = full_write(STDOUT_FILENO, iobuf, count);
1808                 if (count != n)
1809                         break;
1810                 IF_FEATURE_HTTPD_RANGES(range_len -= count;)
1811                 if (range_len == 0)
1812                         break;
1813         }
1814         if (count < 0) {
1815  IF_FEATURE_USE_SENDFILE(fin:)
1816                 if (verbose > 1)
1817                         bb_perror_msg("error");
1818         }
1819         log_and_exit();
1820 }
1821
1822 static void if_ip_denied_send_HTTP_FORBIDDEN_and_exit(void)
1823 {
1824         Htaccess_IP *cur;
1825
1826         for (cur = ip_a_d; cur; cur = cur->next) {
1827 #if DEBUG
1828                 fprintf(stderr,
1829                         "checkPermIP: '%s' ? '%u.%u.%u.%u/%u.%u.%u.%u'\n",
1830                         rmt_ip_str,
1831                         (unsigned char)(cur->ip >> 24),
1832                         (unsigned char)(cur->ip >> 16),
1833                         (unsigned char)(cur->ip >> 8),
1834                         (unsigned char)(cur->ip),
1835                         (unsigned char)(cur->mask >> 24),
1836                         (unsigned char)(cur->mask >> 16),
1837                         (unsigned char)(cur->mask >> 8),
1838                         (unsigned char)(cur->mask)
1839                 );
1840 #endif
1841                 if ((rmt_ip & cur->mask) == cur->ip) {
1842                         if (cur->allow_deny == 'A')
1843                                 return;
1844                         send_headers_and_exit(HTTP_FORBIDDEN);
1845                 }
1846         }
1847
1848         if (flg_deny_all) /* depends on whether we saw "D:*" */
1849                 send_headers_and_exit(HTTP_FORBIDDEN);
1850 }
1851
1852 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
1853
1854 # if ENABLE_PAM
1855 struct pam_userinfo {
1856         const char *name;
1857         const char *pw;
1858 };
1859
1860 static int pam_talker(int num_msg,
1861                 const struct pam_message **msg,
1862                 struct pam_response **resp,
1863                 void *appdata_ptr)
1864 {
1865         int i;
1866         struct pam_userinfo *userinfo = (struct pam_userinfo *) appdata_ptr;
1867         struct pam_response *response;
1868
1869         if (!resp || !msg || !userinfo)
1870                 return PAM_CONV_ERR;
1871
1872         /* allocate memory to store response */
1873         response = xzalloc(num_msg * sizeof(*response));
1874
1875         /* copy values */
1876         for (i = 0; i < num_msg; i++) {
1877                 const char *s;
1878
1879                 switch (msg[i]->msg_style) {
1880                 case PAM_PROMPT_ECHO_ON:
1881                         s = userinfo->name;
1882                         break;
1883                 case PAM_PROMPT_ECHO_OFF:
1884                         s = userinfo->pw;
1885                         break;
1886                 case PAM_ERROR_MSG:
1887                 case PAM_TEXT_INFO:
1888                         s = "";
1889                         break;
1890                 default:
1891                         free(response);
1892                         return PAM_CONV_ERR;
1893                 }
1894                 response[i].resp = xstrdup(s);
1895                 if (PAM_SUCCESS != 0)
1896                         response[i].resp_retcode = PAM_SUCCESS;
1897         }
1898         *resp = response;
1899         return PAM_SUCCESS;
1900 }
1901 # endif
1902
1903 /*
1904  * Config file entries are of the form "/<path>:<user>:<passwd>".
1905  * If config file has no prefix match for path, access is allowed.
1906  *
1907  * path                 The file path
1908  * user_and_passwd      "user:passwd" to validate
1909  *
1910  * Returns 1 if user_and_passwd is OK.
1911  */
1912 static int check_user_passwd(const char *path, char *user_and_passwd)
1913 {
1914         Htaccess *cur;
1915         const char *prev = NULL;
1916
1917         for (cur = g_auth; cur; cur = cur->next) {
1918                 const char *dir_prefix;
1919                 size_t len;
1920                 int r;
1921
1922                 dir_prefix = cur->before_colon;
1923
1924                 /* WHY? */
1925                 /* If already saw a match, don't accept other different matches */
1926                 if (prev && strcmp(prev, dir_prefix) != 0)
1927                         continue;
1928
1929                 if (DEBUG)
1930                         fprintf(stderr, "checkPerm: '%s' ? '%s'\n", dir_prefix, user_and_passwd);
1931
1932                 /* If it's not a prefix match, continue searching */
1933                 len = strlen(dir_prefix);
1934                 if (len != 1 /* dir_prefix "/" matches all, don't need to check */
1935                  && (strncmp(dir_prefix, path, len) != 0
1936                     || (path[len] != '/' && path[len] != '\0')
1937                     )
1938                 ) {
1939                         continue;
1940                 }
1941
1942                 /* Path match found */
1943                 prev = dir_prefix;
1944
1945                 if (ENABLE_FEATURE_HTTPD_AUTH_MD5) {
1946                         char *colon_after_user;
1947                         const char *passwd;
1948 # if ENABLE_FEATURE_SHADOWPASSWDS && !ENABLE_PAM
1949                         char sp_buf[256];
1950 # endif
1951
1952                         colon_after_user = strchr(user_and_passwd, ':');
1953                         if (!colon_after_user)
1954                                 goto bad_input;
1955
1956                         /* compare "user:" */
1957                         if (cur->after_colon[0] != '*'
1958                          && strncmp(cur->after_colon, user_and_passwd,
1959                                         colon_after_user - user_and_passwd + 1) != 0
1960                         ) {
1961                                 continue;
1962                         }
1963                         /* this cfg entry is '*' or matches username from peer */
1964
1965                         passwd = strchr(cur->after_colon, ':');
1966                         if (!passwd)
1967                                 goto bad_input;
1968                         passwd++;
1969                         if (passwd[0] == '*') {
1970 # if ENABLE_PAM
1971                                 struct pam_userinfo userinfo;
1972                                 struct pam_conv conv_info = { &pam_talker, (void *) &userinfo };
1973                                 pam_handle_t *pamh;
1974
1975                                 *colon_after_user = '\0';
1976                                 userinfo.name = user_and_passwd;
1977                                 userinfo.pw = colon_after_user + 1;
1978                                 r = pam_start("httpd", user_and_passwd, &conv_info, &pamh) != PAM_SUCCESS;
1979                                 if (r == 0) {
1980                                         r = pam_authenticate(pamh, PAM_DISALLOW_NULL_AUTHTOK) != PAM_SUCCESS
1981                                          || pam_acct_mgmt(pamh, PAM_DISALLOW_NULL_AUTHTOK)    != PAM_SUCCESS
1982                                         ;
1983                                         pam_end(pamh, PAM_SUCCESS);
1984                                 }
1985                                 *colon_after_user = ':';
1986                                 goto end_check_passwd;
1987 # else
1988 #  if ENABLE_FEATURE_SHADOWPASSWDS
1989                                 /* Using _r function to avoid pulling in static buffers */
1990                                 struct spwd spw;
1991 #  endif
1992                                 struct passwd *pw;
1993
1994                                 *colon_after_user = '\0';
1995                                 pw = getpwnam(user_and_passwd);
1996                                 *colon_after_user = ':';
1997                                 if (!pw || !pw->pw_passwd)
1998                                         continue;
1999                                 passwd = pw->pw_passwd;
2000 #  if ENABLE_FEATURE_SHADOWPASSWDS
2001                                 if ((passwd[0] == 'x' || passwd[0] == '*') && !passwd[1]) {
2002                                         /* getspnam_r may return 0 yet set result to NULL.
2003                                          * At least glibc 2.4 does this. Be extra paranoid here. */
2004                                         struct spwd *result = NULL;
2005                                         r = getspnam_r(pw->pw_name, &spw, sp_buf, sizeof(sp_buf), &result);
2006                                         if (r == 0 && result)
2007                                                 passwd = result->sp_pwdp;
2008                                 }
2009 #  endif
2010                                 /* In this case, passwd is ALWAYS encrypted:
2011                                  * it came from /etc/passwd or /etc/shadow!
2012                                  */
2013                                 goto check_encrypted;
2014 # endif /* ENABLE_PAM */
2015                         }
2016                         /* Else: passwd is from httpd.conf, it is either plaintext or encrypted */
2017
2018                         if (passwd[0] == '$' && isdigit(passwd[1])) {
2019                                 char *encrypted;
2020 # if !ENABLE_PAM
2021  check_encrypted:
2022 # endif
2023                                 /* encrypt pwd from peer and check match with local one */
2024                                 encrypted = pw_encrypt(
2025                                         /* pwd (from peer): */  colon_after_user + 1,
2026                                         /* salt: */ passwd,
2027                                         /* cleanup: */ 0
2028                                 );
2029                                 r = strcmp(encrypted, passwd);
2030                                 free(encrypted);
2031                         } else {
2032                                 /* local passwd is from httpd.conf and it's plaintext */
2033                                 r = strcmp(colon_after_user + 1, passwd);
2034                         }
2035                         goto end_check_passwd;
2036                 }
2037  bad_input:
2038                 /* Comparing plaintext "user:pass" in one go */
2039                 r = strcmp(cur->after_colon, user_and_passwd);
2040  end_check_passwd:
2041                 if (r == 0) {
2042                         remoteuser = xstrndup(user_and_passwd,
2043                                 strchrnul(user_and_passwd, ':') - user_and_passwd
2044                         );
2045                         return 1; /* Ok */
2046                 }
2047         } /* for */
2048
2049         /* 0(bad) if prev is set: matches were found but passwd was wrong */
2050         return (prev == NULL);
2051 }
2052 #endif  /* FEATURE_HTTPD_BASIC_AUTH */
2053
2054 #if ENABLE_FEATURE_HTTPD_PROXY
2055 static Htaccess_Proxy *find_proxy_entry(const char *url)
2056 {
2057         Htaccess_Proxy *p;
2058         for (p = proxy; p; p = p->next) {
2059                 if (is_prefixed_with(url, p->url_from))
2060                         return p;
2061         }
2062         return NULL;
2063 }
2064 #endif
2065
2066 /*
2067  * Handle timeouts
2068  */
2069 static void send_REQUEST_TIMEOUT_and_exit(int sig) NORETURN;
2070 static void send_REQUEST_TIMEOUT_and_exit(int sig UNUSED_PARAM)
2071 {
2072         send_headers_and_exit(HTTP_REQUEST_TIMEOUT);
2073 }
2074
2075 /*
2076  * Handle an incoming http request and exit.
2077  */
2078 static void handle_incoming_and_exit(const len_and_sockaddr *fromAddr) NORETURN;
2079 static void handle_incoming_and_exit(const len_and_sockaddr *fromAddr)
2080 {
2081         static const char request_GET[] ALIGN1 = "GET";
2082         struct stat sb;
2083         char *urlcopy;
2084         char *urlp;
2085         char *tptr;
2086 #if ENABLE_FEATURE_HTTPD_CGI
2087         static const char request_HEAD[] ALIGN1 = "HEAD";
2088         const char *prequest;
2089         char *cookie = NULL;
2090         char *content_type = NULL;
2091         unsigned long length = 0;
2092 #elif ENABLE_FEATURE_HTTPD_PROXY
2093 #define prequest request_GET
2094         unsigned long length = 0;
2095 #endif
2096 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
2097         smallint authorized = -1;
2098 #endif
2099         char http_major_version;
2100 #if ENABLE_FEATURE_HTTPD_PROXY
2101         char http_minor_version;
2102         char *header_buf = header_buf; /* for gcc */
2103         char *header_ptr = header_ptr;
2104         Htaccess_Proxy *proxy_entry;
2105 #endif
2106
2107         /* Allocation of iobuf is postponed until now
2108          * (IOW, server process doesn't need to waste 8k) */
2109         iobuf = xmalloc(IOBUF_SIZE);
2110
2111         rmt_ip = 0;
2112         if (fromAddr->u.sa.sa_family == AF_INET) {
2113                 rmt_ip = ntohl(fromAddr->u.sin.sin_addr.s_addr);
2114         }
2115 #if ENABLE_FEATURE_IPV6
2116         if (fromAddr->u.sa.sa_family == AF_INET6
2117          && fromAddr->u.sin6.sin6_addr.s6_addr32[0] == 0
2118          && fromAddr->u.sin6.sin6_addr.s6_addr32[1] == 0
2119          && ntohl(fromAddr->u.sin6.sin6_addr.s6_addr32[2]) == 0xffff)
2120                 rmt_ip = ntohl(fromAddr->u.sin6.sin6_addr.s6_addr32[3]);
2121 #endif
2122         if (ENABLE_FEATURE_HTTPD_CGI || DEBUG || verbose) {
2123                 /* NB: can be NULL (user runs httpd -i by hand?) */
2124                 rmt_ip_str = xmalloc_sockaddr2dotted(&fromAddr->u.sa);
2125         }
2126         if (verbose) {
2127                 /* this trick makes -v logging much simpler */
2128                 if (rmt_ip_str)
2129                         applet_name = rmt_ip_str;
2130                 if (verbose > 2)
2131                         bb_error_msg("connected");
2132         }
2133
2134         /* Install timeout handler. get_line() needs it. */
2135         signal(SIGALRM, send_REQUEST_TIMEOUT_and_exit);
2136
2137         if (!get_line()) /* EOF or error or empty line */
2138                 send_headers_and_exit(HTTP_BAD_REQUEST);
2139
2140         /* Determine type of request (GET/POST) */
2141         // rfc2616: method and URI is separated by exactly one space
2142         //urlp = strpbrk(iobuf, " \t"); - no, tab isn't allowed
2143         urlp = strchr(iobuf, ' ');
2144         if (urlp == NULL)
2145                 send_headers_and_exit(HTTP_BAD_REQUEST);
2146         *urlp++ = '\0';
2147 #if ENABLE_FEATURE_HTTPD_CGI
2148         prequest = request_GET;
2149         if (strcasecmp(iobuf, prequest) != 0) {
2150                 prequest = request_HEAD;
2151                 if (strcasecmp(iobuf, prequest) != 0) {
2152                         prequest = "POST";
2153                         if (strcasecmp(iobuf, prequest) != 0)
2154                                 send_headers_and_exit(HTTP_NOT_IMPLEMENTED);
2155                 }
2156         }
2157 #else
2158         if (strcasecmp(iobuf, request_GET) != 0)
2159                 send_headers_and_exit(HTTP_NOT_IMPLEMENTED);
2160 #endif
2161         // rfc2616: method and URI is separated by exactly one space
2162         //urlp = skip_whitespace(urlp); - should not be necessary
2163         if (urlp[0] != '/')
2164                 send_headers_and_exit(HTTP_BAD_REQUEST);
2165
2166         /* Find end of URL and parse HTTP version, if any */
2167         http_major_version = '0';
2168         IF_FEATURE_HTTPD_PROXY(http_minor_version = '0';)
2169         tptr = strchrnul(urlp, ' ');
2170         /* Is it " HTTP/"? */
2171         if (tptr[0] && strncmp(tptr + 1, HTTP_200, 5) == 0) {
2172                 http_major_version = tptr[6];
2173                 IF_FEATURE_HTTPD_PROXY(http_minor_version = tptr[8];)
2174         }
2175         *tptr = '\0';
2176
2177         /* Copy URL from after "GET "/"POST " to stack-allocated char[] */
2178         urlcopy = alloca((tptr - urlp) + 2 + strlen(index_page));
2179         /*if (urlcopy == NULL)
2180          *      send_headers_and_exit(HTTP_INTERNAL_SERVER_ERROR);*/
2181         strcpy(urlcopy, urlp);
2182         /* NB: urlcopy ptr is never changed after this */
2183
2184         /* Extract url args if present */
2185         /* g_query = NULL; - already is */
2186         tptr = strchr(urlcopy, '?');
2187         if (tptr) {
2188                 *tptr++ = '\0';
2189                 g_query = tptr;
2190         }
2191
2192         /* Decode URL escape sequences */
2193         tptr = percent_decode_in_place(urlcopy, /*strict:*/ 1);
2194         if (tptr == NULL)
2195                 send_headers_and_exit(HTTP_BAD_REQUEST);
2196         if (tptr == urlcopy + 1) {
2197                 /* '/' or NUL is encoded */
2198                 send_headers_and_exit(HTTP_NOT_FOUND);
2199         }
2200
2201 #if ENABLE_FEATURE_HTTPD_PROXY
2202         proxy_entry = find_proxy_entry(urlcopy);
2203         if (proxy_entry)
2204                 header_buf = header_ptr = xmalloc(IOBUF_SIZE);
2205         else
2206 #endif
2207         {
2208                 /* (If not proxying,) decode URL escape sequences */
2209                 tptr = percent_decode_in_place(urlcopy, /*strict:*/ 1);
2210                 if (tptr == NULL)
2211                         send_headers_and_exit(HTTP_BAD_REQUEST);
2212                 if (tptr == urlcopy + 1) {
2213                         /* '/' or NUL is encoded */
2214                         send_headers_and_exit(HTTP_NOT_FOUND);
2215                 }
2216 //should path canonicalization also be conditional on not proxying?
2217         }
2218
2219         /* Canonicalize path */
2220         /* Algorithm stolen from libbb bb_simplify_path(),
2221          * but don't strdup, retain trailing slash, protect root */
2222         urlp = tptr = urlcopy;
2223         for (;;) {
2224                 if (*urlp == '/') {
2225                         /* skip duplicate (or initial) slash */
2226                         if (*tptr == '/') {
2227                                 goto next_char;
2228                         }
2229                         if (*tptr == '.') {
2230                                 if (tptr[1] == '.' && (tptr[2] == '/' || tptr[2] == '\0')) {
2231                                         /* "..": be careful */
2232                                         /* protect root */
2233                                         if (urlp == urlcopy)
2234                                                 send_headers_and_exit(HTTP_BAD_REQUEST);
2235                                         /* omit previous dir */
2236                                         while (*--urlp != '/')
2237                                                 continue;
2238                                         /* skip to "./" or ".<NUL>" */
2239                                         tptr++;
2240                                 }
2241                                 if (tptr[1] == '/' || tptr[1] == '\0') {
2242                                         /* skip extra "/./" */
2243                                         goto next_char;
2244                                 }
2245                         }
2246                 }
2247                 *++urlp = *tptr;
2248                 if (*tptr == '\0')
2249                         break;
2250  next_char:
2251                 tptr++;
2252         }
2253
2254         /* If URL is a directory, add '/' */
2255         if (urlp[-1] != '/') {
2256                 if (is_directory(urlcopy + 1, /*followlinks:*/ 1)) {
2257                         found_moved_temporarily = urlcopy;
2258                 }
2259         }
2260
2261         /* Log it */
2262         if (verbose > 1)
2263                 bb_error_msg("url:%s", urlcopy);
2264
2265         tptr = urlcopy;
2266         if_ip_denied_send_HTTP_FORBIDDEN_and_exit();
2267         while ((tptr = strchr(tptr + 1, '/')) != NULL) {
2268                 /* have path1/path2 */
2269                 *tptr = '\0';
2270                 if (is_directory(urlcopy + 1, /*followlinks:*/ 1)) {
2271                         /* may have subdir config */
2272                         parse_conf(urlcopy + 1, SUBDIR_PARSE);
2273                         if_ip_denied_send_HTTP_FORBIDDEN_and_exit();
2274                 }
2275                 *tptr = '/';
2276         }
2277
2278         if (http_major_version >= '0') {
2279                 /* Request was with "... HTTP/nXXX", and n >= 0 */
2280
2281                 /* Read until blank line */
2282                 while (1) {
2283                         if (!get_line())
2284                                 break; /* EOF or error or empty line */
2285                         if (DEBUG)
2286                                 bb_error_msg("header: '%s'", iobuf);
2287
2288 #if ENABLE_FEATURE_HTTPD_PROXY
2289                         if (proxy_entry) {
2290                                 /* Why 4, not 2?
2291                                  * We need 2 more bytes for yet another "\r\n" -
2292                                  * see near fdprintf(proxy_fd...) further below.
2293                                  */
2294                                 int maxlen = (IOBUF_SIZE-4) - (int)(header_ptr - header_buf);
2295                                 if (maxlen > 0) {
2296                                         int len = strnlen(iobuf, maxlen);
2297                                         memcpy(header_ptr, iobuf, len);
2298                                         header_ptr += len;
2299                                         header_ptr[0] = '\r';
2300                                         header_ptr[1] = '\n';
2301                                         header_ptr += 2;
2302                                 }
2303                         }
2304 #endif
2305
2306 #if ENABLE_FEATURE_HTTPD_CGI || ENABLE_FEATURE_HTTPD_PROXY
2307                         /* Try and do our best to parse more lines */
2308                         if ((STRNCASECMP(iobuf, "Content-Length:") == 0)) {
2309                                 /* extra read only for POST */
2310                                 if (prequest != request_GET
2311 # if ENABLE_FEATURE_HTTPD_CGI
2312                                  && prequest != request_HEAD
2313 # endif
2314                                 ) {
2315                                         tptr = skip_whitespace(iobuf + sizeof("Content-Length:") - 1);
2316                                         if (!tptr[0])
2317                                                 send_headers_and_exit(HTTP_BAD_REQUEST);
2318                                         /* not using strtoul: it ignores leading minus! */
2319                                         length = bb_strtou(tptr, NULL, 10);
2320                                         /* length is "ulong", but we need to pass it to int later */
2321                                         if (errno || length > INT_MAX)
2322                                                 send_headers_and_exit(HTTP_BAD_REQUEST);
2323                                 }
2324                         }
2325 #endif
2326 #if ENABLE_FEATURE_HTTPD_CGI
2327                         else if (STRNCASECMP(iobuf, "Cookie:") == 0) {
2328                                 if (!cookie) /* in case they send millions of these, do not OOM */
2329                                         cookie = xstrdup(skip_whitespace(iobuf + sizeof("Cookie:")-1));
2330                         } else if (STRNCASECMP(iobuf, "Content-Type:") == 0) {
2331                                 if (!content_type)
2332                                         content_type = xstrdup(skip_whitespace(iobuf + sizeof("Content-Type:")-1));
2333                         } else if (STRNCASECMP(iobuf, "Referer:") == 0) {
2334                                 if (!G.referer)
2335                                         G.referer = xstrdup(skip_whitespace(iobuf + sizeof("Referer:")-1));
2336                         } else if (STRNCASECMP(iobuf, "User-Agent:") == 0) {
2337                                 if (!G.user_agent)
2338                                         G.user_agent = xstrdup(skip_whitespace(iobuf + sizeof("User-Agent:")-1));
2339                         } else if (STRNCASECMP(iobuf, "Host:") == 0) {
2340                                 if (!G.host)
2341                                         G.host = xstrdup(skip_whitespace(iobuf + sizeof("Host:")-1));
2342                         } else if (STRNCASECMP(iobuf, "Accept:") == 0) {
2343                                 if (!G.http_accept)
2344                                         G.http_accept = xstrdup(skip_whitespace(iobuf + sizeof("Accept:")-1));
2345                         } else if (STRNCASECMP(iobuf, "Accept-Language:") == 0) {
2346                                 if (!G.http_accept_language)
2347                                         G.http_accept_language = xstrdup(skip_whitespace(iobuf + sizeof("Accept-Language:")-1));
2348                         }
2349 #endif
2350 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
2351                         if (STRNCASECMP(iobuf, "Authorization:") == 0) {
2352                                 /* We only allow Basic credentials.
2353                                  * It shows up as "Authorization: Basic <user>:<passwd>" where
2354                                  * "<user>:<passwd>" is base64 encoded.
2355                                  */
2356                                 tptr = skip_whitespace(iobuf + sizeof("Authorization:")-1);
2357                                 if (STRNCASECMP(tptr, "Basic") != 0)
2358                                         continue;
2359                                 tptr += sizeof("Basic")-1;
2360                                 /* decodeBase64() skips whitespace itself */
2361                                 decodeBase64(tptr);
2362                                 authorized = check_user_passwd(urlcopy, tptr);
2363                         }
2364 #endif
2365 #if ENABLE_FEATURE_HTTPD_RANGES
2366                         if (STRNCASECMP(iobuf, "Range:") == 0) {
2367                                 /* We know only bytes=NNN-[MMM] */
2368                                 char *s = skip_whitespace(iobuf + sizeof("Range:")-1);
2369                                 if (is_prefixed_with(s, "bytes=")) {
2370                                         s += sizeof("bytes=")-1;
2371                                         range_start = BB_STRTOOFF(s, &s, 10);
2372                                         if (s[0] != '-' || range_start < 0) {
2373                                                 range_start = -1;
2374                                         } else if (s[1]) {
2375                                                 range_end = BB_STRTOOFF(s+1, NULL, 10);
2376                                                 if (errno || range_end < range_start)
2377                                                         range_start = -1;
2378                                         }
2379                                 }
2380                         }
2381 #endif
2382 #if ENABLE_FEATURE_HTTPD_GZIP
2383                         if (STRNCASECMP(iobuf, "Accept-Encoding:") == 0) {
2384                                 /* Note: we do not support "gzip;q=0"
2385                                  * method of _disabling_ gzip
2386                                  * delivery. No one uses that, though */
2387                                 const char *s = strstr(iobuf, "gzip");
2388                                 if (s) {
2389                                         // want more thorough checks?
2390                                         //if (s[-1] == ' '
2391                                         // || s[-1] == ','
2392                                         // || s[-1] == ':'
2393                                         //) {
2394                                                 content_gzip = 1;
2395                                         //}
2396                                 }
2397                         }
2398 #endif
2399                 } /* while extra header reading */
2400         }
2401
2402         /* We are done reading headers, disable peer timeout */
2403         alarm(0);
2404
2405         if (strcmp(bb_basename(urlcopy), HTTPD_CONF) == 0) {
2406                 /* protect listing [/path]/httpd.conf or IP deny */
2407                 send_headers_and_exit(HTTP_FORBIDDEN);
2408         }
2409
2410 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
2411         /* Case: no "Authorization:" was seen, but page might require passwd.
2412          * Check that with dummy user:pass */
2413         if (authorized < 0)
2414                 authorized = check_user_passwd(urlcopy, (char *) "");
2415         if (!authorized)
2416                 send_headers_and_exit(HTTP_UNAUTHORIZED);
2417 #endif
2418
2419         if (found_moved_temporarily) {
2420                 send_headers_and_exit(HTTP_MOVED_TEMPORARILY);
2421         }
2422
2423 #if ENABLE_FEATURE_HTTPD_PROXY
2424         if (proxy_entry) {
2425                 int proxy_fd;
2426                 len_and_sockaddr *lsa;
2427
2428                 lsa = host2sockaddr(proxy_entry->host_port, 80);
2429                 if (lsa == NULL)
2430                         send_headers_and_exit(HTTP_INTERNAL_SERVER_ERROR);
2431                 proxy_fd = socket(lsa->u.sa.sa_family, SOCK_STREAM, 0);
2432                 if (proxy_fd < 0)
2433                         send_headers_and_exit(HTTP_INTERNAL_SERVER_ERROR);
2434                 if (connect(proxy_fd, &lsa->u.sa, lsa->len) < 0)
2435                         send_headers_and_exit(HTTP_INTERNAL_SERVER_ERROR);
2436                 fdprintf(proxy_fd, "%s %s%s%s%s HTTP/%c.%c\r\n",
2437                                 prequest, /* GET or POST */
2438                                 proxy_entry->url_to, /* url part 1 */
2439                                 urlcopy + strlen(proxy_entry->url_from), /* url part 2 */
2440                                 (g_query ? "?" : ""), /* "?" (maybe) */
2441                                 (g_query ? g_query : ""), /* query string (maybe) */
2442                                 http_major_version, http_minor_version);
2443                 header_ptr[0] = '\r';
2444                 header_ptr[1] = '\n';
2445                 header_ptr += 2;
2446                 full_write(proxy_fd, header_buf, header_ptr - header_buf);
2447                 free(header_buf); /* on the order of 8k, free it */
2448                 cgi_io_loop_and_exit(proxy_fd, proxy_fd, length);
2449         }
2450 #endif
2451
2452         tptr = urlcopy + 1;      /* skip first '/' */
2453
2454 #if ENABLE_FEATURE_HTTPD_CGI
2455         if (is_prefixed_with(tptr, "cgi-bin/")) {
2456                 if (tptr[8] == '\0') {
2457                         /* protect listing "cgi-bin/" */
2458                         send_headers_and_exit(HTTP_FORBIDDEN);
2459                 }
2460                 send_cgi_and_exit(urlcopy, urlcopy, prequest, length, cookie, content_type);
2461         }
2462 #endif
2463
2464         if (urlp[-1] == '/') {
2465                 /* When index_page string is appended to <dir>/ URL, it overwrites
2466                  * the query string. If we fall back to call /cgi-bin/index.cgi,
2467                  * query string would be lost and not available to the CGI.
2468                  * Work around it by making a deep copy.
2469                  */
2470                 if (ENABLE_FEATURE_HTTPD_CGI)
2471                         g_query = xstrdup(g_query); /* ok for NULL too */
2472                 strcpy(urlp, index_page);
2473         }
2474         if (stat(tptr, &sb) == 0) {
2475 #if ENABLE_FEATURE_HTTPD_CONFIG_WITH_SCRIPT_INTERPR
2476                 char *suffix = strrchr(tptr, '.');
2477                 if (suffix) {
2478                         Htaccess *cur;
2479                         for (cur = script_i; cur; cur = cur->next) {
2480                                 if (strcmp(cur->before_colon + 1, suffix) == 0) {
2481                                         send_cgi_and_exit(urlcopy, urlcopy, prequest, length, cookie, content_type);
2482                                 }
2483                         }
2484                 }
2485 #endif
2486                 file_size = sb.st_size;
2487                 last_mod = sb.st_mtime;
2488         }
2489 #if ENABLE_FEATURE_HTTPD_CGI
2490         else if (urlp[-1] == '/') {
2491                 /* It's a dir URL and there is no index.html
2492                  * Try cgi-bin/index.cgi */
2493                 if (access("/cgi-bin/index.cgi"+1, X_OK) == 0) {
2494                         urlp[0] = '\0'; /* remove index_page */
2495                         send_cgi_and_exit("/cgi-bin/index.cgi", urlcopy, prequest, length, cookie, content_type);
2496                 }
2497         }
2498         /* else fall through to send_file, it errors out if open fails: */
2499
2500         if (prequest != request_GET && prequest != request_HEAD) {
2501                 /* POST for files does not make sense */
2502                 send_headers_and_exit(HTTP_NOT_IMPLEMENTED);
2503         }
2504         send_file_and_exit(tptr,
2505                 (prequest != request_HEAD ? SEND_HEADERS_AND_BODY : SEND_HEADERS)
2506         );
2507 #else
2508         send_file_and_exit(tptr, SEND_HEADERS_AND_BODY);
2509 #endif
2510 }
2511
2512 /*
2513  * The main http server function.
2514  * Given a socket, listen for new connections and farm out
2515  * the processing as a [v]forked process.
2516  * Never returns.
2517  */
2518 #if BB_MMU
2519 static void mini_httpd(int server_socket) NORETURN;
2520 static void mini_httpd(int server_socket)
2521 {
2522         /* NB: it's best to not use xfuncs in this loop before fork().
2523          * Otherwise server may die on transient errors (temporary
2524          * out-of-memory condition, etc), which is Bad(tm).
2525          * Try to do any dangerous calls after fork.
2526          */
2527         while (1) {
2528                 int n;
2529                 len_and_sockaddr fromAddr;
2530
2531                 /* Wait for connections... */
2532                 fromAddr.len = LSA_SIZEOF_SA;
2533                 n = accept(server_socket, &fromAddr.u.sa, &fromAddr.len);
2534                 if (n < 0)
2535                         continue;
2536
2537                 /* set the KEEPALIVE option to cull dead connections */
2538                 setsockopt_keepalive(n);
2539
2540                 if (fork() == 0) {
2541                         /* child */
2542                         /* Do not reload config on HUP */
2543                         signal(SIGHUP, SIG_IGN);
2544                         close(server_socket);
2545                         xmove_fd(n, 0);
2546                         xdup2(0, 1);
2547
2548                         handle_incoming_and_exit(&fromAddr);
2549                 }
2550                 /* parent, or fork failed */
2551                 close(n);
2552         } /* while (1) */
2553         /* never reached */
2554 }
2555 #else
2556 static void mini_httpd_nommu(int server_socket, int argc, char **argv) NORETURN;
2557 static void mini_httpd_nommu(int server_socket, int argc, char **argv)
2558 {
2559         char *argv_copy[argc + 2];
2560
2561         argv_copy[0] = argv[0];
2562         argv_copy[1] = (char*)"-i";
2563         memcpy(&argv_copy[2], &argv[1], argc * sizeof(argv[0]));
2564
2565         /* NB: it's best to not use xfuncs in this loop before vfork().
2566          * Otherwise server may die on transient errors (temporary
2567          * out-of-memory condition, etc), which is Bad(tm).
2568          * Try to do any dangerous calls after fork.
2569          */
2570         while (1) {
2571                 int n;
2572
2573                 /* Wait for connections... */
2574                 n = accept(server_socket, NULL, NULL);
2575                 if (n < 0)
2576                         continue;
2577
2578                 /* set the KEEPALIVE option to cull dead connections */
2579                 setsockopt_keepalive(n);
2580
2581                 if (vfork() == 0) {
2582                         /* child */
2583                         /* Do not reload config on HUP */
2584                         signal(SIGHUP, SIG_IGN);
2585                         close(server_socket);
2586                         xmove_fd(n, 0);
2587                         xdup2(0, 1);
2588
2589                         /* Run a copy of ourself in inetd mode */
2590                         re_exec(argv_copy);
2591                 }
2592                 argv_copy[0][0] &= 0x7f;
2593                 /* parent, or vfork failed */
2594                 close(n);
2595         } /* while (1) */
2596         /* never reached */
2597 }
2598 #endif
2599
2600 /*
2601  * Process a HTTP connection on stdin/out.
2602  * Never returns.
2603  */
2604 static void mini_httpd_inetd(void) NORETURN;
2605 static void mini_httpd_inetd(void)
2606 {
2607         len_and_sockaddr fromAddr;
2608
2609         memset(&fromAddr, 0, sizeof(fromAddr));
2610         fromAddr.len = LSA_SIZEOF_SA;
2611         /* NB: can fail if user runs it by hand and types in http cmds */
2612         getpeername(0, &fromAddr.u.sa, &fromAddr.len);
2613         handle_incoming_and_exit(&fromAddr);
2614 }
2615
2616 static void sighup_handler(int sig UNUSED_PARAM)
2617 {
2618         int sv = errno;
2619         parse_conf(DEFAULT_PATH_HTTPD_CONF, SIGNALED_PARSE);
2620         errno = sv;
2621 }
2622
2623 enum {
2624         c_opt_config_file = 0,
2625         d_opt_decode_url,
2626         h_opt_home_httpd,
2627         IF_FEATURE_HTTPD_ENCODE_URL_STR(e_opt_encode_url,)
2628         IF_FEATURE_HTTPD_BASIC_AUTH(    r_opt_realm     ,)
2629         IF_FEATURE_HTTPD_AUTH_MD5(      m_opt_md5       ,)
2630         IF_FEATURE_HTTPD_SETUID(        u_opt_setuid    ,)
2631         p_opt_port      ,
2632         p_opt_inetd     ,
2633         p_opt_foreground,
2634         p_opt_verbose   ,
2635         OPT_CONFIG_FILE = 1 << c_opt_config_file,
2636         OPT_DECODE_URL  = 1 << d_opt_decode_url,
2637         OPT_HOME_HTTPD  = 1 << h_opt_home_httpd,
2638         OPT_ENCODE_URL  = IF_FEATURE_HTTPD_ENCODE_URL_STR((1 << e_opt_encode_url)) + 0,
2639         OPT_REALM       = IF_FEATURE_HTTPD_BASIC_AUTH(    (1 << r_opt_realm     )) + 0,
2640         OPT_MD5         = IF_FEATURE_HTTPD_AUTH_MD5(      (1 << m_opt_md5       )) + 0,
2641         OPT_SETUID      = IF_FEATURE_HTTPD_SETUID(        (1 << u_opt_setuid    )) + 0,
2642         OPT_PORT        = 1 << p_opt_port,
2643         OPT_INETD       = 1 << p_opt_inetd,
2644         OPT_FOREGROUND  = 1 << p_opt_foreground,
2645         OPT_VERBOSE     = 1 << p_opt_verbose,
2646 };
2647
2648
2649 int httpd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
2650 int httpd_main(int argc UNUSED_PARAM, char **argv)
2651 {
2652         int server_socket = server_socket; /* for gcc */
2653         unsigned opt;
2654         char *url_for_decode;
2655         IF_FEATURE_HTTPD_ENCODE_URL_STR(const char *url_for_encode;)
2656         IF_FEATURE_HTTPD_SETUID(const char *s_ugid = NULL;)
2657         IF_FEATURE_HTTPD_SETUID(struct bb_uidgid_t ugid;)
2658         IF_FEATURE_HTTPD_AUTH_MD5(const char *pass;)
2659
2660         INIT_G();
2661
2662 #if ENABLE_LOCALE_SUPPORT
2663         /* Undo busybox.c: we want to speak English in http (dates etc) */
2664         setlocale(LC_TIME, "C");
2665 #endif
2666
2667         home_httpd = xrealloc_getcwd_or_warn(NULL);
2668         /* We do not "absolutize" path given by -h (home) opt.
2669          * If user gives relative path in -h,
2670          * $SCRIPT_FILENAME will not be set. */
2671         opt = getopt32(argv, "^"
2672                         "c:d:h:"
2673                         IF_FEATURE_HTTPD_ENCODE_URL_STR("e:")
2674                         IF_FEATURE_HTTPD_BASIC_AUTH("r:")
2675                         IF_FEATURE_HTTPD_AUTH_MD5("m:")
2676                         IF_FEATURE_HTTPD_SETUID("u:")
2677                         "p:ifv"
2678                         "\0"
2679                         /* -v counts, -i implies -f */
2680                         "vv:if",
2681                         &opt_c_configFile, &url_for_decode, &home_httpd
2682                         IF_FEATURE_HTTPD_ENCODE_URL_STR(, &url_for_encode)
2683                         IF_FEATURE_HTTPD_BASIC_AUTH(, &g_realm)
2684                         IF_FEATURE_HTTPD_AUTH_MD5(, &pass)
2685                         IF_FEATURE_HTTPD_SETUID(, &s_ugid)
2686                         , &bind_addr_or_port
2687                         , &verbose
2688                 );
2689         if (opt & OPT_DECODE_URL) {
2690                 fputs(percent_decode_in_place(url_for_decode, /*strict:*/ 0), stdout);
2691                 return 0;
2692         }
2693 #if ENABLE_FEATURE_HTTPD_ENCODE_URL_STR
2694         if (opt & OPT_ENCODE_URL) {
2695                 fputs(encodeString(url_for_encode), stdout);
2696                 return 0;
2697         }
2698 #endif
2699 #if ENABLE_FEATURE_HTTPD_AUTH_MD5
2700         if (opt & OPT_MD5) {
2701                 char salt[sizeof("$1$XXXXXXXX")];
2702                 salt[0] = '$';
2703                 salt[1] = '1';
2704                 salt[2] = '$';
2705                 crypt_make_salt(salt + 3, 4);
2706                 puts(pw_encrypt(pass, salt, /*cleanup:*/ 0));
2707                 return 0;
2708         }
2709 #endif
2710 #if ENABLE_FEATURE_HTTPD_SETUID
2711         if (opt & OPT_SETUID) {
2712                 xget_uidgid(&ugid, s_ugid);
2713         }
2714 #endif
2715
2716 #if !BB_MMU
2717         if (!(opt & OPT_FOREGROUND)) {
2718                 bb_daemonize_or_rexec(0, argv); /* don't change current directory */
2719         }
2720 #endif
2721
2722         xchdir(home_httpd);
2723         if (!(opt & OPT_INETD)) {
2724                 signal(SIGCHLD, SIG_IGN);
2725                 server_socket = openServer();
2726 #if ENABLE_FEATURE_HTTPD_SETUID
2727                 /* drop privileges */
2728                 if (opt & OPT_SETUID) {
2729                         if (ugid.gid != (gid_t)-1) {
2730                                 if (setgroups(1, &ugid.gid) == -1)
2731                                         bb_perror_msg_and_die("setgroups");
2732                                 xsetgid(ugid.gid);
2733                         }
2734                         xsetuid(ugid.uid);
2735                 }
2736 #endif
2737         }
2738
2739 #if 0
2740         /* User can do it himself: 'env - PATH="$PATH" httpd'
2741          * We don't do it because we don't want to screw users
2742          * which want to do
2743          * 'env - VAR1=val1 VAR2=val2 httpd'
2744          * and have VAR1 and VAR2 values visible in their CGIs.
2745          * Besides, it is also smaller. */
2746         {
2747                 char *p = getenv("PATH");
2748                 /* env strings themself are not freed, no need to xstrdup(p): */
2749                 clearenv();
2750                 if (p)
2751                         putenv(p - 5);
2752 //              if (!(opt & OPT_INETD))
2753 //                      setenv_long("SERVER_PORT", ???);
2754         }
2755 #endif
2756
2757         parse_conf(DEFAULT_PATH_HTTPD_CONF, FIRST_PARSE);
2758         if (!(opt & OPT_INETD))
2759                 signal(SIGHUP, sighup_handler);
2760
2761         xfunc_error_retval = 0;
2762         if (opt & OPT_INETD)
2763                 mini_httpd_inetd(); /* never returns */
2764 #if BB_MMU
2765         if (!(opt & OPT_FOREGROUND))
2766                 bb_daemonize(0); /* don't change current directory */
2767         mini_httpd(server_socket); /* never returns */
2768 #else
2769         mini_httpd_nommu(server_socket, argc, argv); /* never returns */
2770 #endif
2771         /* return 0; */
2772 }