networking/httpd.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * httpd implementation for busybox
   4  *
   5  * Copyright (C) 2002,2003 Glenn Engel <glenne@engel.org>
   6  * Copyright (C) 2003-2006 Vladimir Oleynik <dzo@simtreas.ru>
   7  *
   8  * Licensed under GPLv2 or later, see file LICENSE in this source tree.
   9  *
  10  *****************************************************************************
  11  *
  12  * Typical usage:
  13  * For non root user:
  14  *      httpd -p 8080 -h $HOME/public_html
  15  * For daemon start from rc script with uid=0:
  16  *      httpd -u www
  17  * which is equivalent to (assuming user www has uid 80):
  18  *      httpd -p 80 -u 80 -h $PWD -c /etc/httpd.conf -r "Web Server Authentication"
  19  *
  20  * When an url starts with "/cgi-bin/" it is assumed to be a cgi script.
  21  * The server changes directory to the location of the script and executes it
  22  * after setting QUERY_STRING and other environment variables.
  23  *
  24  * If directory URL is given, no index.html is found and CGI support is enabled,
  25  * cgi-bin/index.cgi will be run. Directory to list is ../$QUERY_STRING.
  26  * See httpd_indexcgi.c for an example GCI code.
  27  *
  28  * Doc:
  29  * "CGI Environment Variables": http://hoohoo.ncsa.uiuc.edu/cgi/env.html
  30  *
  31  * The applet can also be invoked as an url arg decoder and html text encoder
  32  * as follows:
  33  *      foo=`httpd -d $foo`             # decode "Hello%20World" as "Hello World"
  34  *      bar=`httpd -e "<Hello World>"`  # encode as "&#60Hello&#32World&#62"
  35  * Note that url encoding for arguments is not the same as html encoding for
  36  * presentation.  -d decodes an url-encoded argument while -e encodes in html
  37  * for page display.
  38  *
  39  * httpd.conf has the following format:
  40  *
  41  * H:/serverroot     # define the server root. It will override -h
  42  * A:172.20.         # Allow address from 172.20.0.0/16
  43  * A:10.0.0.0/25     # Allow any address from 10.0.0.0-10.0.0.127
  44  * A:10.0.0.0/255.255.255.128  # Allow any address that previous set
  45  * A:127.0.0.1       # Allow local loopback connections
  46  * D:*               # Deny from other IP connections
  47  * E404:/path/e404.html # /path/e404.html is the 404 (not found) error page
  48  * I:index.html      # Show index.html when a directory is requested
  49  *
  50  * P:/url:[http://]hostname[:port]/new/path
  51  *                   # When /urlXXXXXX is requested, reverse proxy
  52  *                   # it to http://hostname[:port]/new/pathXXXXXX
  53  *
  54  * /cgi-bin:foo:bar  # Require user foo, pwd bar on urls starting with /cgi-bin/
  55  * /adm:admin:setup  # Require user admin, pwd setup on urls starting with /adm/
  56  * /adm:toor:PaSsWd  # or user toor, pwd PaSsWd on urls starting with /adm/
  57  * /adm:root:*       # or user root, pwd from /etc/passwd on urls starting with /adm/
  58  * /wiki:*:*         # or any user from /etc/passwd with according pwd on urls starting with /wiki/
  59  * .au:audio/basic   # additional mime type for audio.au files
  60  * *.php:/path/php   # run xxx.php through an interpreter
  61  *
  62  * A/D may be as a/d or allow/deny - only first char matters.
  63  * Deny/Allow IP logic:
  64  *  - Default is to allow all (Allow all (A:*) is a no-op).
  65  *  - Deny rules take precedence over allow rules.
  66  *  - "Deny all" rule (D:*) is applied last.
  67  *
  68  * Example:
  69  *   1. Allow only specified addresses
  70  *     A:172.20          # Allow any address that begins with 172.20.
  71  *     A:10.10.          # Allow any address that begins with 10.10.
  72  *     A:127.0.0.1       # Allow local loopback connections
  73  *     D:*               # Deny from other IP connections
  74  *
  75  *   2. Only deny specified addresses
  76  *     D:1.2.3.        # deny from 1.2.3.0 - 1.2.3.255
  77  *     D:2.3.4.        # deny from 2.3.4.0 - 2.3.4.255
  78  *     A:*             # (optional line added for clarity)
  79  *
  80  * If a sub directory contains config file, it is parsed and merged with
  81  * any existing settings as if it was appended to the original configuration.
  82  *
  83  * subdir paths are relative to the containing subdir and thus cannot
  84  * affect the parent rules.
  85  *
  86  * Note that since the sub dir is parsed in the forked thread servicing the
  87  * subdir http request, any merge is discarded when the process exits.  As a
  88  * result, the subdir settings only have a lifetime of a single request.
  89  *
  90  * Custom error pages can contain an absolute path or be relative to
  91  * 'home_httpd'. Error pages are to be static files (no CGI or script). Error
  92  * page can only be defined in the root configuration file and are not taken
  93  * into account in local (directories) config files.
  94  *
  95  * If -c is not set, an attempt will be made to open the default
  96  * root configuration file.  If -c is set and the file is not found, the
  97  * server exits with an error.
  98  *
  99  */
 100  /* TODO: use TCP_CORK, parse_config() */
 101 //config:config HTTPD
 102 //config:       bool "httpd"
 103 //config:       default y
 104 //config:       help
 105 //config:         Serve web pages via an HTTP server.
 106 //config:
 107 //config:config FEATURE_HTTPD_RANGES
 108 //config:       bool "Support 'Ranges:' header"
 109 //config:       default y
 110 //config:       depends on HTTPD
 111 //config:       help
 112 //config:         Makes httpd emit "Accept-Ranges: bytes" header and understand
 113 //config:         "Range: bytes=NNN-[MMM]" header. Allows for resuming interrupted
 114 //config:         downloads, seeking in multimedia players etc.
 115 //config:
 116 //config:config FEATURE_HTTPD_SETUID
 117 //config:       bool "Enable -u <user> option"
 118 //config:       default y
 119 //config:       depends on HTTPD
 120 //config:       help
 121 //config:         This option allows the server to run as a specific user
 122 //config:         rather than defaulting to the user that starts the server.
 123 //config:         Use of this option requires special privileges to change to a
 124 //config:         different user.
 125 //config:
 126 //config:config FEATURE_HTTPD_BASIC_AUTH
 127 //config:       bool "Enable Basic http Authentication"
 128 //config:       default y
 129 //config:       depends on HTTPD
 130 //config:       help
 131 //config:         Utilizes password settings from /etc/httpd.conf for basic
 132 //config:         authentication on a per url basis.
 133 //config:         Example for httpd.conf file:
 134 //config:         /adm:toor:PaSsWd
 135 //config:
 136 //config:config FEATURE_HTTPD_AUTH_MD5
 137 //config:       bool "Support MD5 crypted passwords for http Authentication"
 138 //config:       default y
 139 //config:       depends on FEATURE_HTTPD_BASIC_AUTH
 140 //config:       help
 141 //config:         Enables encrypted passwords, and wildcard user/passwords
 142 //config:         in httpd.conf file.
 143 //config:         User '*' means 'any system user name is ok',
 144 //config:         password of '*' means 'use system password for this user'
 145 //config:         Examples:
 146 //config:         /adm:toor:$1$P/eKnWXS$aI1aPGxT.dJD5SzqAKWrF0
 147 //config:         /adm:root:*
 148 //config:         /wiki:*:*
 149 //config:
 150 //config:config FEATURE_HTTPD_CGI
 151 //config:       bool "Support Common Gateway Interface (CGI)"
 152 //config:       default y
 153 //config:       depends on HTTPD
 154 //config:       help
 155 //config:         This option allows scripts and executables to be invoked
 156 //config:         when specific URLs are requested.
 157 //config:
 158 //config:config FEATURE_HTTPD_CONFIG_WITH_SCRIPT_INTERPR
 159 //config:       bool "Support for running scripts through an interpreter"
 160 //config:       default y
 161 //config:       depends on FEATURE_HTTPD_CGI
 162 //config:       help
 163 //config:         This option enables support for running scripts through an
 164 //config:         interpreter. Turn this on if you want PHP scripts to work
 165 //config:         properly. You need to supply an additional line in your
 166 //config:         httpd.conf file:
 167 //config:         *.php:/path/to/your/php
 168 //config:
 169 //config:config FEATURE_HTTPD_SET_REMOTE_PORT_TO_ENV
 170 //config:       bool "Set REMOTE_PORT environment variable for CGI"
 171 //config:       default y
 172 //config:       depends on FEATURE_HTTPD_CGI
 173 //config:       help
 174 //config:         Use of this option can assist scripts in generating
 175 //config:         references that contain a unique port number.
 176 //config:
 177 //config:config FEATURE_HTTPD_ENCODE_URL_STR
 178 //config:       bool "Enable -e option (useful for CGIs written as shell scripts)"
 179 //config:       default y
 180 //config:       depends on HTTPD
 181 //config:       help
 182 //config:         This option allows html encoding of arbitrary strings for display
 183 //config:         by the browser. Output goes to stdout.
 184 //config:         For example, httpd -e "<Hello World>" produces
 185 //config:         "&#60Hello&#32World&#62".
 186 //config:
 187 //config:config FEATURE_HTTPD_ERROR_PAGES
 188 //config:       bool "Support for custom error pages"
 189 //config:       default y
 190 //config:       depends on HTTPD
 191 //config:       help
 192 //config:         This option allows you to define custom error pages in
 193 //config:         the configuration file instead of the default HTTP status
 194 //config:         error pages. For instance, if you add the line:
 195 //config:               E404:/path/e404.html
 196 //config:         in the config file, the server will respond the specified
 197 //config:         '/path/e404.html' file instead of the terse '404 NOT FOUND'
 198 //config:         message.
 199 //config:
 200 //config:config FEATURE_HTTPD_PROXY
 201 //config:       bool "Support for reverse proxy"
 202 //config:       default y
 203 //config:       depends on HTTPD
 204 //config:       help
 205 //config:         This option allows you to define URLs that will be forwarded
 206 //config:         to another HTTP server. To setup add the following line to the
 207 //config:         configuration file
 208 //config:               P:/url/:http://hostname[:port]/new/path/
 209 //config:         Then a request to /url/myfile will be forwarded to
 210 //config:         http://hostname[:port]/new/path/myfile.
 211 //config:
 212 //config:config FEATURE_HTTPD_GZIP
 213 //config:       bool "Support for GZIP content encoding"
 214 //config:       default y
 215 //config:       depends on HTTPD
 216 //config:       help
 217 //config:         Makes httpd send files using GZIP content encoding if the
 218 //config:         client supports it and a pre-compressed <file>.gz exists.
 219
 220 //applet:IF_HTTPD(APPLET(httpd, BB_DIR_USR_SBIN, BB_SUID_DROP))
 221
 222 //kbuild:lib-$(CONFIG_HTTPD) += httpd.o
 223
 224 //usage:#define httpd_trivial_usage
 225 //usage:       "[-ifv[v]]"
 226 //usage:       " [-c CONFFILE]"
 227 //usage:       " [-p [IP:]PORT]"
 228 //usage:        IF_FEATURE_HTTPD_SETUID(" [-u USER[:GRP]]")
 229 //usage:        IF_FEATURE_HTTPD_BASIC_AUTH(" [-r REALM]")
 230 //usage:       " [-h HOME]\n"
 231 //usage:       "or httpd -d/-e" IF_FEATURE_HTTPD_AUTH_MD5("/-m") " STRING"
 232 //usage:#define httpd_full_usage "\n\n"
 233 //usage:       "Listen for incoming HTTP requests\n"
 234 //usage:     "\n        -i              Inetd mode"
 235 //usage:     "\n        -f              Don't daemonize"
 236 //usage:     "\n        -v[v]           Verbose"
 237 //usage:     "\n        -p [IP:]PORT    Bind to IP:PORT (default *:80)"
 238 //usage:        IF_FEATURE_HTTPD_SETUID(
 239 //usage:     "\n        -u USER[:GRP]   Set uid/gid after binding to port")
 240 //usage:        IF_FEATURE_HTTPD_BASIC_AUTH(
 241 //usage:     "\n        -r REALM        Authentication Realm for Basic Authentication")
 242 //usage:     "\n        -h HOME         Home directory (default .)"
 243 //usage:     "\n        -c FILE         Configuration file (default {/etc,HOME}/httpd.conf)"
 244 //usage:        IF_FEATURE_HTTPD_AUTH_MD5(
 245 //usage:     "\n        -m STRING       MD5 crypt STRING")
 246 //usage:     "\n        -e STRING       HTML encode STRING"
 247 //usage:     "\n        -d STRING       URL decode STRING"
 248
 249 #include "libbb.h"
 250 #include "common_bufsiz.h"
 251 #if ENABLE_PAM
 252 /* PAM may include <locale.h>. We may need to undefine bbox's stub define: */
 253 # undef setlocale
 254 /* For some obscure reason, PAM is not in pam/xxx, but in security/xxx.
 255  * Apparently they like to confuse people. */
 256 # include <security/pam_appl.h>
 257 # include <security/pam_misc.h>
 258 #endif
 259 #if ENABLE_FEATURE_USE_SENDFILE
 260 # include <sys/sendfile.h>
 261 #endif
 262 /* amount of buffering in a pipe */
 263 #ifndef PIPE_BUF
 264 # define PIPE_BUF 4096
 265 #endif
 266
 267 #define DEBUG 0
 268
 269 #define IOBUF_SIZE 8192
 270 #if PIPE_BUF >= IOBUF_SIZE
 271 # error "PIPE_BUF >= IOBUF_SIZE"
 272 #endif
 273
 274 #define HEADER_READ_TIMEOUT 60
 275
 276 static const char DEFAULT_PATH_HTTPD_CONF[] ALIGN1 = "/etc";
 277 static const char HTTPD_CONF[] ALIGN1 = "httpd.conf";
 278 static const char HTTP_200[] ALIGN1 = "HTTP/1.0 200 OK\r\n";
 279 static const char index_html[] ALIGN1 = "index.html";
 280
 281 typedef struct has_next_ptr {
 282         struct has_next_ptr *next;
 283 } has_next_ptr;
 284
 285 /* Must have "next" as a first member */
 286 typedef struct Htaccess {
 287         struct Htaccess *next;
 288         char *after_colon;
 289         char before_colon[1];  /* really bigger, must be last */
 290 } Htaccess;
 291
 292 /* Must have "next" as a first member */
 293 typedef struct Htaccess_IP {
 294         struct Htaccess_IP *next;
 295         unsigned ip;
 296         unsigned mask;
 297         int allow_deny;
 298 } Htaccess_IP;
 299
 300 /* Must have "next" as a first member */
 301 typedef struct Htaccess_Proxy {
 302         struct Htaccess_Proxy *next;
 303         char *url_from;
 304         char *host_port;
 305         char *url_to;
 306 } Htaccess_Proxy;
 307
 308 enum {
 309         HTTP_OK = 200,
 310         HTTP_PARTIAL_CONTENT = 206,
 311         HTTP_MOVED_TEMPORARILY = 302,
 312         HTTP_BAD_REQUEST = 400,       /* malformed syntax */
 313         HTTP_UNAUTHORIZED = 401, /* authentication needed, respond with auth hdr */
 314         HTTP_NOT_FOUND = 404,
 315         HTTP_FORBIDDEN = 403,
 316         HTTP_REQUEST_TIMEOUT = 408,
 317         HTTP_NOT_IMPLEMENTED = 501,   /* used for unrecognized requests */
 318         HTTP_INTERNAL_SERVER_ERROR = 500,
 319         HTTP_CONTINUE = 100,
 320 #if 0   /* future use */
 321         HTTP_SWITCHING_PROTOCOLS = 101,
 322         HTTP_CREATED = 201,
 323         HTTP_ACCEPTED = 202,
 324         HTTP_NON_AUTHORITATIVE_INFO = 203,
 325         HTTP_NO_CONTENT = 204,
 326         HTTP_MULTIPLE_CHOICES = 300,
 327         HTTP_MOVED_PERMANENTLY = 301,
 328         HTTP_NOT_MODIFIED = 304,
 329         HTTP_PAYMENT_REQUIRED = 402,
 330         HTTP_BAD_GATEWAY = 502,
 331         HTTP_SERVICE_UNAVAILABLE = 503, /* overload, maintenance */
 332 #endif
 333 };
 334
 335 static const uint16_t http_response_type[] ALIGN2 = {
 336         HTTP_OK,
 337 #if ENABLE_FEATURE_HTTPD_RANGES
 338         HTTP_PARTIAL_CONTENT,
 339 #endif
 340         HTTP_MOVED_TEMPORARILY,
 341         HTTP_REQUEST_TIMEOUT,
 342         HTTP_NOT_IMPLEMENTED,
 343 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
 344         HTTP_UNAUTHORIZED,
 345 #endif
 346         HTTP_NOT_FOUND,
 347         HTTP_BAD_REQUEST,
 348         HTTP_FORBIDDEN,
 349         HTTP_INTERNAL_SERVER_ERROR,
 350 #if 0   /* not implemented */
 351         HTTP_CREATED,
 352         HTTP_ACCEPTED,
 353         HTTP_NO_CONTENT,
 354         HTTP_MULTIPLE_CHOICES,
 355         HTTP_MOVED_PERMANENTLY,
 356         HTTP_NOT_MODIFIED,
 357         HTTP_BAD_GATEWAY,
 358         HTTP_SERVICE_UNAVAILABLE,
 359 #endif
 360 };
 361
 362 static const struct {
 363         const char *name;
 364         const char *info;
 365 } http_response[ARRAY_SIZE(http_response_type)] = {
 366         { "OK", NULL },
 367 #if ENABLE_FEATURE_HTTPD_RANGES
 368         { "Partial Content", NULL },
 369 #endif
 370         { "Found", NULL },
 371         { "Request Timeout", "No request appeared within 60 seconds" },
 372         { "Not Implemented", "The requested method is not recognized" },
 373 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
 374         { "Unauthorized", "" },
 375 #endif
 376         { "Not Found", "The requested URL was not found" },
 377         { "Bad Request", "Unsupported method" },
 378         { "Forbidden", ""  },
 379         { "Internal Server Error", "Internal Server Error" },
 380 #if 0   /* not implemented */
 381         { "Created" },
 382         { "Accepted" },
 383         { "No Content" },
 384         { "Multiple Choices" },
 385         { "Moved Permanently" },
 386         { "Not Modified" },
 387         { "Bad Gateway", "" },
 388         { "Service Unavailable", "" },
 389 #endif
 390 };
 391
 392 struct globals {
 393         int verbose;            /* must be int (used by getopt32) */
 394         smallint flg_deny_all;
 395
 396         unsigned rmt_ip;        /* used for IP-based allow/deny rules */
 397         time_t last_mod;
 398         char *rmt_ip_str;       /* for $REMOTE_ADDR and $REMOTE_PORT */
 399         const char *bind_addr_or_port;
 400
 401         const char *g_query;
 402         const char *opt_c_configFile;
 403         const char *home_httpd;
 404         const char *index_page;
 405
 406         const char *found_mime_type;
 407         const char *found_moved_temporarily;
 408         Htaccess_IP *ip_a_d;    /* config allow/deny lines */
 409
 410         IF_FEATURE_HTTPD_BASIC_AUTH(const char *g_realm;)
 411         IF_FEATURE_HTTPD_BASIC_AUTH(char *remoteuser;)
 412         IF_FEATURE_HTTPD_CGI(char *referer;)
 413         IF_FEATURE_HTTPD_CGI(char *user_agent;)
 414         IF_FEATURE_HTTPD_CGI(char *host;)
 415         IF_FEATURE_HTTPD_CGI(char *http_accept;)
 416         IF_FEATURE_HTTPD_CGI(char *http_accept_language;)
 417
 418         off_t file_size;        /* -1 - unknown */
 419 #if ENABLE_FEATURE_HTTPD_RANGES
 420         off_t range_start;
 421         off_t range_end;
 422         off_t range_len;
 423 #endif
 424
 425 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
 426         Htaccess *g_auth;       /* config user:password lines */
 427 #endif
 428         Htaccess *mime_a;       /* config mime types */
 429 #if ENABLE_FEATURE_HTTPD_CONFIG_WITH_SCRIPT_INTERPR
 430         Htaccess *script_i;     /* config script interpreters */
 431 #endif
 432         char *iobuf;            /* [IOBUF_SIZE] */
 433 #define        hdr_buf bb_common_bufsiz1
 434 #define sizeof_hdr_buf COMMON_BUFSIZE
 435         char *hdr_ptr;
 436         int hdr_cnt;
 437 #if ENABLE_FEATURE_HTTPD_ERROR_PAGES
 438         const char *http_error_page[ARRAY_SIZE(http_response_type)];
 439 #endif
 440 #if ENABLE_FEATURE_HTTPD_PROXY
 441         Htaccess_Proxy *proxy;
 442 #endif
 443 #if ENABLE_FEATURE_HTTPD_GZIP
 444         /* client can handle gzip / we are going to send gzip */
 445         smallint content_gzip;
 446 #endif
 447 };
 448 #define G (*ptr_to_globals)
 449 #define verbose           (G.verbose          )
 450 #define flg_deny_all      (G.flg_deny_all     )
 451 #define rmt_ip            (G.rmt_ip           )
 452 #define bind_addr_or_port (G.bind_addr_or_port)
 453 #define g_query           (G.g_query          )
 454 #define opt_c_configFile  (G.opt_c_configFile )
 455 #define home_httpd        (G.home_httpd       )
 456 #define index_page        (G.index_page       )
 457 #define found_mime_type   (G.found_mime_type  )
 458 #define found_moved_temporarily (G.found_moved_temporarily)
 459 #define last_mod          (G.last_mod         )
 460 #define ip_a_d            (G.ip_a_d           )
 461 #define g_realm           (G.g_realm          )
 462 #define remoteuser        (G.remoteuser       )
 463 #define referer           (G.referer          )
 464 #define user_agent        (G.user_agent       )
 465 #define host              (G.host             )
 466 #define http_accept       (G.http_accept      )
 467 #define http_accept_language (G.http_accept_language)
 468 #define file_size         (G.file_size        )
 469 #if ENABLE_FEATURE_HTTPD_RANGES
 470 #define range_start       (G.range_start      )
 471 #define range_end         (G.range_end        )
 472 #define range_len         (G.range_len        )
 473 #else
 474 enum {
 475         range_start = -1,
 476         range_end = MAXINT(off_t) - 1,
 477         range_len = MAXINT(off_t),
 478 };
 479 #endif
 480 #define rmt_ip_str        (G.rmt_ip_str       )
 481 #define g_auth            (G.g_auth           )
 482 #define mime_a            (G.mime_a           )
 483 #define script_i          (G.script_i         )
 484 #define iobuf             (G.iobuf            )
 485 #define hdr_ptr           (G.hdr_ptr          )
 486 #define hdr_cnt           (G.hdr_cnt          )
 487 #define http_error_page   (G.http_error_page  )
 488 #define proxy             (G.proxy            )
 489 #if ENABLE_FEATURE_HTTPD_GZIP
 490 # define content_gzip     (G.content_gzip     )
 491 #else
 492 # define content_gzip     0
 493 #endif
 494 #define INIT_G() do { \
 495         setup_common_bufsiz(); \
 496         SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
 497         IF_FEATURE_HTTPD_BASIC_AUTH(g_realm = "Web Server Authentication";) \
 498         IF_FEATURE_HTTPD_RANGES(range_start = -1;) \
 499         bind_addr_or_port = "80"; \
 500         index_page = index_html; \
 501         file_size = -1; \
 502 } while (0)
 503
 504
 505 #define STRNCASECMP(a, str) strncasecmp((a), (str), sizeof(str)-1)
 506
 507 /* Prototypes */
 508 enum {
 509         SEND_HEADERS     = (1 << 0),
 510         SEND_BODY        = (1 << 1),
 511         SEND_HEADERS_AND_BODY = SEND_HEADERS + SEND_BODY,
 512 };
 513 static void send_file_and_exit(const char *url, int what) NORETURN;
 514
 515 static void free_llist(has_next_ptr **pptr)
 516 {
 517         has_next_ptr *cur = *pptr;
 518         while (cur) {
 519                 has_next_ptr *t = cur;
 520                 cur = cur->next;
 521                 free(t);
 522         }
 523         *pptr = NULL;
 524 }
 525
 526 static ALWAYS_INLINE void free_Htaccess_list(Htaccess **pptr)
 527 {
 528         free_llist((has_next_ptr**)pptr);
 529 }
 530
 531 static ALWAYS_INLINE void free_Htaccess_IP_list(Htaccess_IP **pptr)
 532 {
 533         free_llist((has_next_ptr**)pptr);
 534 }
 535
 536 /* Returns presumed mask width in bits or < 0 on error.
 537  * Updates strp, stores IP at provided pointer */
 538 static int scan_ip(const char **strp, unsigned *ipp, unsigned char endc)
 539 {
 540         const char *p = *strp;
 541         int auto_mask = 8;
 542         unsigned ip = 0;
 543         int j;
 544
 545         if (*p == '/')
 546                 return -auto_mask;
 547
 548         for (j = 0; j < 4; j++) {
 549                 unsigned octet;
 550
 551                 if ((*p < '0' || *p > '9') && *p != '/' && *p)
 552                         return -auto_mask;
 553                 octet = 0;
 554                 while (*p >= '0' && *p <= '9') {
 555                         octet *= 10;
 556                         octet += *p - '0';
 557                         if (octet > 255)
 558                                 return -auto_mask;
 559                         p++;
 560                 }
 561                 if (*p == '.')
 562                         p++;
 563                 if (*p != '/' && *p)
 564                         auto_mask += 8;
 565                 ip = (ip << 8) | octet;
 566         }
 567         if (*p) {
 568                 if (*p != endc)
 569                         return -auto_mask;
 570                 p++;
 571                 if (*p == '\0')
 572                         return -auto_mask;
 573         }
 574         *ipp = ip;
 575         *strp = p;
 576         return auto_mask;
 577 }
 578
 579 /* Returns 0 on success. Stores IP and mask at provided pointers */
 580 static int scan_ip_mask(const char *str, unsigned *ipp, unsigned *maskp)
 581 {
 582         int i;
 583         unsigned mask;
 584         char *p;
 585
 586         i = scan_ip(&str, ipp, '/');
 587         if (i < 0)
 588                 return i;
 589
 590         if (*str) {
 591                 /* there is /xxx after dotted-IP address */
 592                 i = bb_strtou(str, &p, 10);
 593                 if (*p == '.') {
 594                         /* 'xxx' itself is dotted-IP mask, parse it */
 595                         /* (return 0 (success) only if it has N.N.N.N form) */
 596                         return scan_ip(&str, maskp, '\0') - 32;
 597                 }
 598                 if (*p)
 599                         return -1;
 600         }
 601
 602         if (i > 32)
 603                 return -1;
 604
 605         if (sizeof(unsigned) == 4 && i == 32) {
 606                 /* mask >>= 32 below may not work */
 607                 mask = 0;
 608         } else {
 609                 mask = 0xffffffff;
 610                 mask >>= i;
 611         }
 612         /* i == 0 -> *maskp = 0x00000000
 613          * i == 1 -> *maskp = 0x80000000
 614          * i == 4 -> *maskp = 0xf0000000
 615          * i == 31 -> *maskp = 0xfffffffe
 616          * i == 32 -> *maskp = 0xffffffff */
 617         *maskp = (uint32_t)(~mask);
 618         return 0;
 619 }
 620
 621 /*
 622  * Parse configuration file into in-memory linked list.
 623  *
 624  * Any previous IP rules are discarded.
 625  * If the flag argument is not SUBDIR_PARSE then all /path and mime rules
 626  * are also discarded.  That is, previous settings are retained if flag is
 627  * SUBDIR_PARSE.
 628  * Error pages are only parsed on the main config file.
 629  *
 630  * path   Path where to look for httpd.conf (without filename).
 631  * flag   Type of the parse request.
 632  */
 633 /* flag param: */
 634 enum {
 635         FIRST_PARSE    = 0, /* path will be "/etc" */
 636         SIGNALED_PARSE = 1, /* path will be "/etc" */
 637         SUBDIR_PARSE   = 2, /* path will be derived from URL */
 638 };
 639 static void parse_conf(const char *path, int flag)
 640 {
 641         /* internally used extra flag state */
 642         enum { TRY_CURDIR_PARSE = 3 };
 643
 644         FILE *f;
 645         const char *filename;
 646         char buf[160];
 647
 648         /* discard old rules */
 649         free_Htaccess_IP_list(&ip_a_d);
 650         flg_deny_all = 0;
 651         /* retain previous auth and mime config only for subdir parse */
 652         if (flag != SUBDIR_PARSE) {
 653                 free_Htaccess_list(&mime_a);
 654 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
 655                 free_Htaccess_list(&g_auth);
 656 #endif
 657 #if ENABLE_FEATURE_HTTPD_CONFIG_WITH_SCRIPT_INTERPR
 658                 free_Htaccess_list(&script_i);
 659 #endif
 660         }
 661
 662         filename = opt_c_configFile;
 663         if (flag == SUBDIR_PARSE || filename == NULL) {
 664                 filename = alloca(strlen(path) + sizeof(HTTPD_CONF) + 2);
 665                 sprintf((char *)filename, "%s/%s", path, HTTPD_CONF);
 666         }
 667
 668         while ((f = fopen_for_read(filename)) == NULL) {
 669                 if (flag >= SUBDIR_PARSE) { /* SUBDIR or TRY_CURDIR */
 670                         /* config file not found, no changes to config */
 671                         return;
 672                 }
 673                 if (flag == FIRST_PARSE) {
 674                         /* -c CONFFILE given, but CONFFILE doesn't exist? */
 675                         if (opt_c_configFile)
 676                                 bb_simple_perror_msg_and_die(opt_c_configFile);
 677                         /* else: no -c, thus we looked at /etc/httpd.conf,
 678                          * and it's not there. try ./httpd.conf: */
 679                 }
 680                 flag = TRY_CURDIR_PARSE;
 681                 filename = HTTPD_CONF;
 682         }
 683
 684 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
 685         /* in "/file:user:pass" lines, we prepend path in subdirs */
 686         if (flag != SUBDIR_PARSE)
 687                 path = "";
 688 #endif
 689         /* The lines can be:
 690          *
 691          * I:default_index_file
 692          * H:http_home
 693          * [AD]:IP[/mask]   # allow/deny, * for wildcard
 694          * Ennn:error.html  # error page for status nnn
 695          * P:/url:[http://]hostname[:port]/new/path # reverse proxy
 696          * .ext:mime/type   # mime type
 697          * *.php:/path/php  # run xxx.php through an interpreter
 698          * /file:user:pass  # username and password
 699          */
 700         while (fgets(buf, sizeof(buf), f) != NULL) {
 701                 unsigned strlen_buf;
 702                 unsigned char ch;
 703                 char *after_colon;
 704
 705                 { /* remove all whitespace, and # comments */
 706                         char *p, *p0;
 707
 708                         p0 = buf;
 709                         /* skip non-whitespace beginning. Often the whole line
 710                          * is non-whitespace. We want this case to work fast,
 711                          * without needless copying, therefore we don't merge
 712                          * this operation into next while loop. */
 713                         while ((ch = *p0) != '\0' && ch != '\n' && ch != '#'
 714                          && ch != ' ' && ch != '\t'
 715                         ) {
 716                                 p0++;
 717                         }
 718                         p = p0;
 719                         /* if we enter this loop, we have some whitespace.
 720                          * discard it */
 721                         while (ch != '\0' && ch != '\n' && ch != '#') {
 722                                 if (ch != ' ' && ch != '\t') {
 723                                         *p++ = ch;
 724                                 }
 725                                 ch = *++p0;
 726                         }
 727                         *p = '\0';
 728                         strlen_buf = p - buf;
 729                         if (strlen_buf == 0)
 730                                 continue; /* empty line */
 731                 }
 732
 733                 after_colon = strchr(buf, ':');
 734                 /* strange line? */
 735                 if (after_colon == NULL || *++after_colon == '\0')
 736                         goto config_error;
 737
 738                 ch = (buf[0] & ~0x20); /* toupper if it's a letter */
 739
 740                 if (ch == 'I') {
 741                         if (index_page != index_html)
 742                                 free((char*)index_page);
 743                         index_page = xstrdup(after_colon);
 744                         continue;
 745                 }
 746
 747                 /* do not allow jumping around using H in subdir's configs */
 748                 if (flag == FIRST_PARSE && ch == 'H') {
 749                         home_httpd = xstrdup(after_colon);
 750                         xchdir(home_httpd);
 751                         continue;
 752                 }
 753
 754                 if (ch == 'A' || ch == 'D') {
 755                         Htaccess_IP *pip;
 756
 757                         if (*after_colon == '*') {
 758                                 if (ch == 'D') {
 759                                         /* memorize "deny all" */
 760                                         flg_deny_all = 1;
 761                                 }
 762                                 /* skip assumed "A:*", it is a default anyway */
 763                                 continue;
 764                         }
 765                         /* store "allow/deny IP/mask" line */
 766                         pip = xzalloc(sizeof(*pip));
 767                         if (scan_ip_mask(after_colon, &pip->ip, &pip->mask)) {
 768                                 /* IP{/mask} syntax error detected, protect all */
 769                                 ch = 'D';
 770                                 pip->mask = 0;
 771                         }
 772                         pip->allow_deny = ch;
 773                         if (ch == 'D') {
 774                                 /* Deny:from_IP - prepend */
 775                                 pip->next = ip_a_d;
 776                                 ip_a_d = pip;
 777                         } else {
 778                                 /* A:from_IP - append (thus all D's precedes A's) */
 779                                 Htaccess_IP *prev_IP = ip_a_d;
 780                                 if (prev_IP == NULL) {
 781                                         ip_a_d = pip;
 782                                 } else {
 783                                         while (prev_IP->next)
 784                                                 prev_IP = prev_IP->next;
 785                                         prev_IP->next = pip;
 786                                 }
 787                         }
 788                         continue;
 789                 }
 790
 791 #if ENABLE_FEATURE_HTTPD_ERROR_PAGES
 792                 if (flag == FIRST_PARSE && ch == 'E') {
 793                         unsigned i;
 794                         int status = atoi(buf + 1); /* error status code */
 795
 796                         if (status < HTTP_CONTINUE) {
 797                                 goto config_error;
 798                         }
 799                         /* then error page; find matching status */
 800                         for (i = 0; i < ARRAY_SIZE(http_response_type); i++) {
 801                                 if (http_response_type[i] == status) {
 802                                         /* We chdir to home_httpd, thus no need to
 803                                          * concat_path_file(home_httpd, after_colon)
 804                                          * here */
 805                                         http_error_page[i] = xstrdup(after_colon);
 806                                         break;
 807                                 }
 808                         }
 809                         continue;
 810                 }
 811 #endif
 812
 813 #if ENABLE_FEATURE_HTTPD_PROXY
 814                 if (flag == FIRST_PARSE && ch == 'P') {
 815                         /* P:/url:[http://]hostname[:port]/new/path */
 816                         char *url_from, *host_port, *url_to;
 817                         Htaccess_Proxy *proxy_entry;
 818
 819                         url_from = after_colon;
 820                         host_port = strchr(after_colon, ':');
 821                         if (host_port == NULL) {
 822                                 goto config_error;
 823                         }
 824                         *host_port++ = '\0';
 825                         if (is_prefixed_with(host_port, "http://"))
 826                                 host_port += 7;
 827                         if (*host_port == '\0') {
 828                                 goto config_error;
 829                         }
 830                         url_to = strchr(host_port, '/');
 831                         if (url_to == NULL) {
 832                                 goto config_error;
 833                         }
 834                         *url_to = '\0';
 835                         proxy_entry = xzalloc(sizeof(*proxy_entry));
 836                         proxy_entry->url_from = xstrdup(url_from);
 837                         proxy_entry->host_port = xstrdup(host_port);
 838                         *url_to = '/';
 839                         proxy_entry->url_to = xstrdup(url_to);
 840                         proxy_entry->next = proxy;
 841                         proxy = proxy_entry;
 842                         continue;
 843                 }
 844 #endif
 845                 /* the rest of directives are non-alphabetic,
 846                  * must avoid using "toupper'ed" ch */
 847                 ch = buf[0];
 848
 849                 if (ch == '.' /* ".ext:mime/type" */
 850 #if ENABLE_FEATURE_HTTPD_CONFIG_WITH_SCRIPT_INTERPR
 851                  || (ch == '*' && buf[1] == '.') /* "*.php:/path/php" */
 852 #endif
 853                 ) {
 854                         char *p;
 855                         Htaccess *cur;
 856
 857                         cur = xzalloc(sizeof(*cur) /* includes space for NUL */ + strlen_buf);
 858                         strcpy(cur->before_colon, buf);
 859                         p = cur->before_colon + (after_colon - buf);
 860                         p[-1] = '\0';
 861                         cur->after_colon = p;
 862                         if (ch == '.') {
 863                                 /* .mime line: prepend to mime_a list */
 864                                 cur->next = mime_a;
 865                                 mime_a = cur;
 866                         }
 867 #if ENABLE_FEATURE_HTTPD_CONFIG_WITH_SCRIPT_INTERPR
 868                         else {
 869                                 /* script interpreter line: prepend to script_i list */
 870                                 cur->next = script_i;
 871                                 script_i = cur;
 872                         }
 873 #endif
 874                         continue;
 875                 }
 876
 877 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
 878                 if (ch == '/') { /* "/file:user:pass" */
 879                         char *p;
 880                         Htaccess *cur;
 881                         unsigned file_len;
 882
 883                         /* note: path is "" unless we are in SUBDIR parse,
 884                          * otherwise it does NOT start with "/" */
 885                         cur = xzalloc(sizeof(*cur) /* includes space for NUL */
 886                                 + 1 + strlen(path)
 887                                 + strlen_buf
 888                                 );
 889                         /* form "/path/file" */
 890                         sprintf(cur->before_colon, "/%s%.*s",
 891                                 path,
 892                                 (int) (after_colon - buf - 1), /* includes "/", but not ":" */
 893                                 buf);
 894                         /* canonicalize it */
 895                         p = bb_simplify_abs_path_inplace(cur->before_colon);
 896                         file_len = p - cur->before_colon;
 897                         /* add "user:pass" after NUL */
 898                         strcpy(++p, after_colon);
 899                         cur->after_colon = p;
 900
 901                         /* insert cur into g_auth */
 902                         /* g_auth is sorted by decreased filename length */
 903                         {
 904                                 Htaccess *auth, **authp;
 905
 906                                 authp = &g_auth;
 907                                 while ((auth = *authp) != NULL) {
 908                                         if (file_len >= strlen(auth->before_colon)) {
 909                                                 /* insert cur before auth */
 910                                                 cur->next = auth;
 911                                                 break;
 912                                         }
 913                                         authp = &auth->next;
 914                                 }
 915                                 *authp = cur;
 916                         }
 917                         continue;
 918                 }
 919 #endif /* BASIC_AUTH */
 920
 921                 /* the line is not recognized */
 922  config_error:
 923                 bb_error_msg("config error '%s' in '%s'", buf, filename);
 924         } /* while (fgets) */
 925
 926         fclose(f);
 927 }
 928
 929 #if ENABLE_FEATURE_HTTPD_ENCODE_URL_STR
 930 /*
 931  * Given a string, html-encode special characters.
 932  * This is used for the -e command line option to provide an easy way
 933  * for scripts to encode result data without confusing browsers.  The
 934  * returned string pointer is memory allocated by malloc().
 935  *
 936  * Returns a pointer to the encoded string (malloced).
 937  */
 938 static char *encodeString(const char *string)
 939 {
 940         /* take the simple route and encode everything */
 941         /* could possibly scan once to get length.     */
 942         int len = strlen(string);
 943         char *out = xmalloc(len * 6 + 1);
 944         char *p = out;
 945         char ch;
 946
 947         while ((ch = *string++) != '\0') {
 948                 /* very simple check for what to encode */
 949                 if (isalnum(ch))
 950                         *p++ = ch;
 951                 else
 952                         p += sprintf(p, "&#%d;", (unsigned char) ch);
 953         }
 954         *p = '\0';
 955         return out;
 956 }
 957 #endif
 958
 959 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
 960 /*
 961  * Decode a base64 data stream as per rfc1521.
 962  * Note that the rfc states that non base64 chars are to be ignored.
 963  * Since the decode always results in a shorter size than the input,
 964  * it is OK to pass the input arg as an output arg.
 965  * Parameter: a pointer to a base64 encoded string.
 966  * Decoded data is stored in-place.
 967  */
 968 static void decodeBase64(char *Data)
 969 {
 970         const unsigned char *in = (const unsigned char *)Data;
 971         /* The decoded size will be at most 3/4 the size of the encoded */
 972         unsigned ch = 0;
 973         int i = 0;
 974
 975         while (*in) {
 976                 int t = *in++;
 977
 978                 if (t >= '0' && t <= '9')
 979                         t = t - '0' + 52;
 980                 else if (t >= 'A' && t <= 'Z')
 981                         t = t - 'A';
 982                 else if (t >= 'a' && t <= 'z')
 983                         t = t - 'a' + 26;
 984                 else if (t == '+')
 985                         t = 62;
 986                 else if (t == '/')
 987                         t = 63;
 988                 else if (t == '=')
 989                         t = 0;
 990                 else
 991                         continue;
 992
 993                 ch = (ch << 6) | t;
 994                 i++;
 995                 if (i == 4) {
 996                         *Data++ = (char) (ch >> 16);
 997                         *Data++ = (char) (ch >> 8);
 998                         *Data++ = (char) ch;
 999                         i = 0;
1000                 }
1001         }
1002         *Data = '\0';
1003 }
1004 #endif
1005
1006 /*
1007  * Create a listen server socket on the designated port.
1008  */
1009 static int openServer(void)
1010 {
1011         unsigned n = bb_strtou(bind_addr_or_port, NULL, 10);
1012         if (!errno && n && n <= 0xffff)
1013                 n = create_and_bind_stream_or_die(NULL, n);
1014         else
1015                 n = create_and_bind_stream_or_die(bind_addr_or_port, 80);
1016         xlisten(n, 9);
1017         return n;
1018 }
1019
1020 /*
1021  * Log the connection closure and exit.
1022  */
1023 static void log_and_exit(void) NORETURN;
1024 static void log_and_exit(void)
1025 {
1026         /* Paranoia. IE said to be buggy. It may send some extra data
1027          * or be confused by us just exiting without SHUT_WR. Oh well. */
1028         shutdown(1, SHUT_WR);
1029         /* Why??
1030         (this also messes up stdin when user runs httpd -i from terminal)
1031         ndelay_on(0);
1032         while (read(STDIN_FILENO, iobuf, IOBUF_SIZE) > 0)
1033                 continue;
1034         */
1035
1036         if (verbose > 2)
1037                 bb_error_msg("closed");
1038         _exit(xfunc_error_retval);
1039 }
1040
1041 /*
1042  * Create and send HTTP response headers.
1043  * The arguments are combined and sent as one write operation.  Note that
1044  * IE will puke big-time if the headers are not sent in one packet and the
1045  * second packet is delayed for any reason.
1046  * responseNum - the result code to send.
1047  */
1048 static void send_headers(int responseNum)
1049 {
1050         static const char RFC1123FMT[] ALIGN1 = "%a, %d %b %Y %H:%M:%S GMT";
1051         /* Fixed size 29-byte string. Example: Sun, 06 Nov 1994 08:49:37 GMT */
1052         char date_str[40]; /* using a bit larger buffer to paranoia reasons */
1053
1054         const char *responseString = "";
1055         const char *infoString = NULL;
1056 #if ENABLE_FEATURE_HTTPD_ERROR_PAGES
1057         const char *error_page = NULL;
1058 #endif
1059         unsigned i;
1060         time_t timer = time(NULL);
1061         int len;
1062
1063         for (i = 0; i < ARRAY_SIZE(http_response_type); i++) {
1064                 if (http_response_type[i] == responseNum) {
1065                         responseString = http_response[i].name;
1066                         infoString = http_response[i].info;
1067 #if ENABLE_FEATURE_HTTPD_ERROR_PAGES
1068                         error_page = http_error_page[i];
1069 #endif
1070                         break;
1071                 }
1072         }
1073
1074         if (verbose)
1075                 bb_error_msg("response:%u", responseNum);
1076
1077         /* We use sprintf, not snprintf (it's less code).
1078          * iobuf[] is several kbytes long and all headers we generate
1079          * always fit into those kbytes.
1080          */
1081
1082         strftime(date_str, sizeof(date_str), RFC1123FMT, gmtime(&timer));
1083         len = sprintf(iobuf,
1084                         "HTTP/1.0 %d %s\r\n"
1085                         "Content-type: %s\r\n"
1086                         "Date: %s\r\n"
1087                         "Connection: close\r\n",
1088                         responseNum, responseString,
1089                         /* if it's error message, then it's HTML */
1090                         (responseNum == HTTP_OK ? found_mime_type : "text/html"),
1091                         date_str
1092         );
1093
1094 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
1095         if (responseNum == HTTP_UNAUTHORIZED) {
1096                 len += sprintf(iobuf + len,
1097                                 "WWW-Authenticate: Basic realm=\"%.999s\"\r\n",
1098                                 g_realm /* %.999s protects from overflowing iobuf[] */
1099                 );
1100         }
1101 #endif
1102         if (responseNum == HTTP_MOVED_TEMPORARILY) {
1103                 /* Responding to "GET /dir" with
1104                  * "HTTP/1.0 302 Found" "Location: /dir/"
1105                  * - IOW, asking them to repeat with a slash.
1106                  * Here, overflow IS possible, can't use sprintf:
1107                  * mkdir test
1108                  * python -c 'print("get /test?" + ("x" * 8192))' | busybox httpd -i -h .
1109                  */
1110                 len += snprintf(iobuf + len, IOBUF_SIZE-3 - len,
1111                                 "Location: %s/%s%s\r\n",
1112                                 found_moved_temporarily,
1113                                 (g_query ? "?" : ""),
1114                                 (g_query ? g_query : "")
1115                 );
1116                 if (len > IOBUF_SIZE-3)
1117                         len = IOBUF_SIZE-3;
1118         }
1119
1120 #if ENABLE_FEATURE_HTTPD_ERROR_PAGES
1121         if (error_page && access(error_page, R_OK) == 0) {
1122                 iobuf[len++] = '\r';
1123                 iobuf[len++] = '\n';
1124                 if (DEBUG) {
1125                         iobuf[len] = '\0';
1126                         fprintf(stderr, "headers: '%s'\n", iobuf);
1127                 }
1128                 full_write(STDOUT_FILENO, iobuf, len);
1129                 if (DEBUG)
1130                         fprintf(stderr, "writing error page: '%s'\n", error_page);
1131                 return send_file_and_exit(error_page, SEND_BODY);
1132         }
1133 #endif
1134
1135         if (file_size != -1) {    /* file */
1136                 strftime(date_str, sizeof(date_str), RFC1123FMT, gmtime(&last_mod));
1137 #if ENABLE_FEATURE_HTTPD_RANGES
1138                 if (responseNum == HTTP_PARTIAL_CONTENT) {
1139                         len += sprintf(iobuf + len,
1140                                 "Content-Range: bytes %"OFF_FMT"u-%"OFF_FMT"u/%"OFF_FMT"u\r\n",
1141                                         range_start,
1142                                         range_end,
1143                                         file_size
1144                         );
1145                         file_size = range_end - range_start + 1;
1146                 }
1147 #endif
1148                 len += sprintf(iobuf + len,
1149 #if ENABLE_FEATURE_HTTPD_RANGES
1150                         "Accept-Ranges: bytes\r\n"
1151 #endif
1152                         "Last-Modified: %s\r\n"
1153                         "%s %"OFF_FMT"u\r\n",
1154                                 date_str,
1155                                 content_gzip ? "Transfer-length:" : "Content-length:",
1156                                 file_size
1157                 );
1158         }
1159
1160         if (content_gzip)
1161                 len += sprintf(iobuf + len, "Content-Encoding: gzip\r\n");
1162
1163         iobuf[len++] = '\r';
1164         iobuf[len++] = '\n';
1165         if (infoString) {
1166                 len += sprintf(iobuf + len,
1167                                 "<HTML><HEAD><TITLE>%d %s</TITLE></HEAD>\n"
1168                                 "<BODY><H1>%d %s</H1>\n"
1169                                 "%s\n"
1170                                 "</BODY></HTML>\n",
1171                                 responseNum, responseString,
1172                                 responseNum, responseString,
1173                                 infoString
1174                 );
1175         }
1176         if (DEBUG) {
1177                 iobuf[len] = '\0';
1178                 fprintf(stderr, "headers: '%s'\n", iobuf);
1179         }
1180         if (full_write(STDOUT_FILENO, iobuf, len) != len) {
1181                 if (verbose > 1)
1182                         bb_perror_msg("error");
1183                 log_and_exit();
1184         }
1185 }
1186
1187 static void send_headers_and_exit(int responseNum) NORETURN;
1188 static void send_headers_and_exit(int responseNum)
1189 {
1190         IF_FEATURE_HTTPD_GZIP(content_gzip = 0;)
1191         send_headers(responseNum);
1192         log_and_exit();
1193 }
1194
1195 /*
1196  * Read from the socket until '\n' or EOF. '\r' chars are removed.
1197  * '\n' is replaced with NUL.
1198  * Return number of characters read or 0 if nothing is read
1199  * ('\r' and '\n' are not counted).
1200  * Data is returned in iobuf.
1201  */
1202 static int get_line(void)
1203 {
1204         int count = 0;
1205         char c;
1206
1207         alarm(HEADER_READ_TIMEOUT);
1208         while (1) {
1209                 if (hdr_cnt <= 0) {
1210                         hdr_cnt = safe_read(STDIN_FILENO, hdr_buf, sizeof_hdr_buf);
1211                         if (hdr_cnt <= 0)
1212                                 break;
1213                         hdr_ptr = hdr_buf;
1214                 }
1215                 iobuf[count] = c = *hdr_ptr++;
1216                 hdr_cnt--;
1217
1218                 if (c == '\r')
1219                         continue;
1220                 if (c == '\n') {
1221                         iobuf[count] = '\0';
1222                         break;
1223                 }
1224                 if (count < (IOBUF_SIZE - 1))      /* check overflow */
1225                         count++;
1226         }
1227         return count;
1228 }
1229
1230 #if ENABLE_FEATURE_HTTPD_CGI || ENABLE_FEATURE_HTTPD_PROXY
1231
1232 /* gcc 4.2.1 fares better with NOINLINE */
1233 static NOINLINE void cgi_io_loop_and_exit(int fromCgi_rd, int toCgi_wr, int post_len) NORETURN;
1234 static NOINLINE void cgi_io_loop_and_exit(int fromCgi_rd, int toCgi_wr, int post_len)
1235 {
1236         enum { FROM_CGI = 1, TO_CGI = 2 }; /* indexes in pfd[] */
1237         struct pollfd pfd[3];
1238         int out_cnt; /* we buffer a bit of initial CGI output */
1239         int count;
1240
1241         /* iobuf is used for CGI -> network data,
1242          * hdr_buf is for network -> CGI data (POSTDATA) */
1243
1244         /* If CGI dies, we still want to correctly finish reading its output
1245          * and send it to the peer. So please no SIGPIPEs! */
1246         signal(SIGPIPE, SIG_IGN);
1247
1248         // We inconsistently handle a case when more POSTDATA from network
1249         // is coming than we expected. We may give *some part* of that
1250         // extra data to CGI.
1251
1252         //if (hdr_cnt > post_len) {
1253         //      /* We got more POSTDATA from network than we expected */
1254         //      hdr_cnt = post_len;
1255         //}
1256         post_len -= hdr_cnt;
1257         /* post_len - number of POST bytes not yet read from network */
1258
1259         /* NB: breaking out of this loop jumps to log_and_exit() */
1260         out_cnt = 0;
1261         pfd[FROM_CGI].fd = fromCgi_rd;
1262         pfd[FROM_CGI].events = POLLIN;
1263         pfd[TO_CGI].fd = toCgi_wr;
1264         while (1) {
1265                 /* Note: even pfd[0].events == 0 won't prevent
1266                  * revents == POLLHUP|POLLERR reports from closed stdin.
1267                  * Setting fd to -1 works: */
1268                 pfd[0].fd = -1;
1269                 pfd[0].events = POLLIN;
1270                 pfd[0].revents = 0; /* probably not needed, paranoia */
1271
1272                 /* We always poll this fd, thus kernel always sets revents: */
1273                 /*pfd[FROM_CGI].events = POLLIN; - moved out of loop */
1274                 /*pfd[FROM_CGI].revents = 0; - not needed */
1275
1276                 /* gcc-4.8.0 still doesnt fill two shorts with one insn :( */
1277                 /* http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47059 */
1278                 /* hopefully one day it will... */
1279                 pfd[TO_CGI].events = POLLOUT;
1280                 pfd[TO_CGI].revents = 0; /* needed! */
1281
1282                 if (toCgi_wr && hdr_cnt <= 0) {
1283                         if (post_len > 0) {
1284                                 /* Expect more POST data from network */
1285                                 pfd[0].fd = 0;
1286                         } else {
1287                                 /* post_len <= 0 && hdr_cnt <= 0:
1288                                  * no more POST data to CGI,
1289                                  * let CGI see EOF on CGI's stdin */
1290                                 if (toCgi_wr != fromCgi_rd)
1291                                         close(toCgi_wr);
1292                                 toCgi_wr = 0;
1293                         }
1294                 }
1295
1296                 /* Now wait on the set of sockets */
1297                 count = safe_poll(pfd, hdr_cnt > 0 ? TO_CGI+1 : FROM_CGI+1, -1);
1298                 if (count <= 0) {
1299 #if 0
1300                         if (safe_waitpid(pid, &status, WNOHANG) <= 0) {
1301                                 /* Weird. CGI didn't exit and no fd's
1302                                  * are ready, yet poll returned?! */
1303                                 continue;
1304                         }
1305                         if (DEBUG && WIFEXITED(status))
1306                                 bb_error_msg("CGI exited, status=%d", WEXITSTATUS(status));
1307                         if (DEBUG && WIFSIGNALED(status))
1308                                 bb_error_msg("CGI killed, signal=%d", WTERMSIG(status));
1309 #endif
1310                         break;
1311                 }
1312
1313                 if (pfd[TO_CGI].revents) {
1314                         /* hdr_cnt > 0 here due to the way poll() called */
1315                         /* Have data from peer and can write to CGI */
1316                         count = safe_write(toCgi_wr, hdr_ptr, hdr_cnt);
1317                         /* Doesn't happen, we dont use nonblocking IO here
1318                          *if (count < 0 && errno == EAGAIN) {
1319                          *      ...
1320                          *} else */
1321                         if (count > 0) {
1322                                 hdr_ptr += count;
1323                                 hdr_cnt -= count;
1324                         } else {
1325                                 /* EOF/broken pipe to CGI, stop piping POST data */
1326                                 hdr_cnt = post_len = 0;
1327                         }
1328                 }
1329
1330                 if (pfd[0].revents) {
1331                         /* post_len > 0 && hdr_cnt == 0 here */
1332                         /* We expect data, prev data portion is eaten by CGI
1333                          * and there *is* data to read from the peer
1334                          * (POSTDATA) */
1335                         //count = post_len > (int)sizeof_hdr_buf ? (int)sizeof_hdr_buf : post_len;
1336                         //count = safe_read(STDIN_FILENO, hdr_buf, count);
1337                         count = safe_read(STDIN_FILENO, hdr_buf, sizeof_hdr_buf);
1338                         if (count > 0) {
1339                                 hdr_cnt = count;
1340                                 hdr_ptr = hdr_buf;
1341                                 post_len -= count;
1342                         } else {
1343                                 /* no more POST data can be read */
1344                                 post_len = 0;
1345                         }
1346                 }
1347
1348                 if (pfd[FROM_CGI].revents) {
1349                         /* There is something to read from CGI */
1350                         char *rbuf = iobuf;
1351
1352                         /* Are we still buffering CGI output? */
1353                         if (out_cnt >= 0) {
1354                                 /* HTTP_200[] has single "\r\n" at the end.
1355                                  * According to http://hoohoo.ncsa.uiuc.edu/cgi/out.html,
1356                                  * CGI scripts MUST send their own header terminated by
1357                                  * empty line, then data. That's why we have only one
1358                                  * <cr><lf> pair here. We will output "200 OK" line
1359                                  * if needed, but CGI still has to provide blank line
1360                                  * between header and body */
1361
1362                                 /* Must use safe_read, not full_read, because
1363                                  * CGI may output a few first bytes and then wait
1364                                  * for POSTDATA without closing stdout.
1365                                  * With full_read we may wait here forever. */
1366                                 count = safe_read(fromCgi_rd, rbuf + out_cnt, PIPE_BUF - 8);
1367                                 if (count <= 0) {
1368                                         /* eof (or error) and there was no "HTTP",
1369                                          * so write it, then write received data */
1370                                         if (out_cnt) {
1371                                                 full_write(STDOUT_FILENO, HTTP_200, sizeof(HTTP_200)-1);
1372                                                 full_write(STDOUT_FILENO, rbuf, out_cnt);
1373                                         }
1374                                         break; /* CGI stdout is closed, exiting */
1375                                 }
1376                                 out_cnt += count;
1377                                 count = 0;
1378                                 /* "Status" header format is: "Status: 302 Redirected\r\n" */
1379                                 if (out_cnt >= 7 && memcmp(rbuf, "Status:", 7) == 0) {
1380                                         /* send "HTTP/1.0 " */
1381                                         if (full_write(STDOUT_FILENO, HTTP_200, 9) != 9)
1382                                                 break;
1383                                         rbuf += 7; /* skip "Status:" */
1384                                         count = out_cnt - 7;
1385                                         out_cnt = -1; /* buffering off */
1386                                 } else if (out_cnt >= 4) {
1387                                         /* Did CGI add "HTTP"? */
1388                                         if (memcmp(rbuf, HTTP_200, 4) != 0) {
1389                                                 /* there is no "HTTP", do it ourself */
1390                                                 if (full_write(STDOUT_FILENO, HTTP_200, sizeof(HTTP_200)-1) != sizeof(HTTP_200)-1)
1391                                                         break;
1392                                         }
1393                                         /* Commented out:
1394                                         if (!strstr(rbuf, "ontent-")) {
1395                                                 full_write(s, "Content-type: text/plain\r\n\r\n", 28);
1396                                         }
1397                                          * Counter-example of valid CGI without Content-type:
1398                                          * echo -en "HTTP/1.0 302 Found\r\n"
1399                                          * echo -en "Location: http://www.busybox.net\r\n"
1400                                          * echo -en "\r\n"
1401                                          */
1402                                         count = out_cnt;
1403                                         out_cnt = -1; /* buffering off */
1404                                 }
1405                         } else {
1406                                 count = safe_read(fromCgi_rd, rbuf, PIPE_BUF);
1407                                 if (count <= 0)
1408                                         break;  /* eof (or error) */
1409                         }
1410                         if (full_write(STDOUT_FILENO, rbuf, count) != count)
1411                                 break;
1412                         if (DEBUG)
1413                                 fprintf(stderr, "cgi read %d bytes: '%.*s'\n", count, count, rbuf);
1414                 } /* if (pfd[FROM_CGI].revents) */
1415         } /* while (1) */
1416         log_and_exit();
1417 }
1418 #endif
1419
1420 #if ENABLE_FEATURE_HTTPD_CGI
1421
1422 static void setenv1(const char *name, const char *value)
1423 {
1424         setenv(name, value ? value : "", 1);
1425 }
1426
1427 /*
1428  * Spawn CGI script, forward CGI's stdin/out <=> network
1429  *
1430  * Environment variables are set up and the script is invoked with pipes
1431  * for stdin/stdout.  If a POST is being done the script is fed the POST
1432  * data in addition to setting the QUERY_STRING variable (for GETs or POSTs).
1433  *
1434  * Parameters:
1435  * const char *url              The requested URL (with leading /).
1436  * const char *orig_uri         The original URI before rewriting (if any)
1437  * int post_len                 Length of the POST body.
1438  * const char *cookie           For set HTTP_COOKIE.
1439  * const char *content_type     For set CONTENT_TYPE.
1440  */
1441 static void send_cgi_and_exit(
1442                 const char *url,
1443                 const char *orig_uri,
1444                 const char *request,
1445                 int post_len,
1446                 const char *cookie,
1447                 const char *content_type) NORETURN;
1448 static void send_cgi_and_exit(
1449                 const char *url,
1450                 const char *orig_uri,
1451                 const char *request,
1452                 int post_len,
1453                 const char *cookie,
1454                 const char *content_type)
1455 {
1456         struct fd_pair fromCgi;  /* CGI -> httpd pipe */
1457         struct fd_pair toCgi;    /* httpd -> CGI pipe */
1458         char *script, *last_slash;
1459         int pid;
1460
1461         /* Make a copy. NB: caller guarantees:
1462          * url[0] == '/', url[1] != '/' */
1463         url = xstrdup(url);
1464
1465         /*
1466          * We are mucking with environment _first_ and then vfork/exec,
1467          * this allows us to use vfork safely. Parent doesn't care about
1468          * these environment changes anyway.
1469          */
1470
1471         /* Check for [dirs/]script.cgi/PATH_INFO */
1472         last_slash = script = (char*)url;
1473         while ((script = strchr(script + 1, '/')) != NULL) {
1474                 int dir;
1475                 *script = '\0';
1476                 dir = is_directory(url + 1, /*followlinks:*/ 1);
1477                 *script = '/';
1478                 if (!dir) {
1479                         /* not directory, found script.cgi/PATH_INFO */
1480                         break;
1481                 }
1482                 /* is directory, find next '/' */
1483                 last_slash = script;
1484         }
1485         setenv1("PATH_INFO", script);   /* set to /PATH_INFO or "" */
1486         setenv1("REQUEST_METHOD", request);
1487         if (g_query) {
1488                 putenv(xasprintf("%s=%s?%s", "REQUEST_URI", orig_uri, g_query));
1489         } else {
1490                 setenv1("REQUEST_URI", orig_uri);
1491         }
1492         if (script != NULL)
1493                 *script = '\0';         /* cut off /PATH_INFO */
1494
1495         /* SCRIPT_FILENAME is required by PHP in CGI mode */
1496         if (home_httpd[0] == '/') {
1497                 char *fullpath = concat_path_file(home_httpd, url);
1498                 setenv1("SCRIPT_FILENAME", fullpath);
1499         }
1500         /* set SCRIPT_NAME as full path: /cgi-bin/dirs/script.cgi */
1501         setenv1("SCRIPT_NAME", url);
1502         /* http://hoohoo.ncsa.uiuc.edu/cgi/env.html:
1503          * QUERY_STRING: The information which follows the ? in the URL
1504          * which referenced this script. This is the query information.
1505          * It should not be decoded in any fashion. This variable
1506          * should always be set when there is query information,
1507          * regardless of command line decoding. */
1508         /* (Older versions of bbox seem to do some decoding) */
1509         setenv1("QUERY_STRING", g_query);
1510         putenv((char*)"SERVER_SOFTWARE=busybox httpd/"BB_VER);
1511         putenv((char*)"SERVER_PROTOCOL=HTTP/1.0");
1512         putenv((char*)"GATEWAY_INTERFACE=CGI/1.1");
1513         /* Having _separate_ variables for IP and port defeats
1514          * the purpose of having socket abstraction. Which "port"
1515          * are you using on Unix domain socket?
1516          * IOW - REMOTE_PEER="1.2.3.4:56" makes much more sense.
1517          * Oh well... */
1518         {
1519                 char *p = rmt_ip_str ? rmt_ip_str : (char*)"";
1520                 char *cp = strrchr(p, ':');
1521                 if (ENABLE_FEATURE_IPV6 && cp && strchr(cp, ']'))
1522                         cp = NULL;
1523                 if (cp) *cp = '\0'; /* delete :PORT */
1524                 setenv1("REMOTE_ADDR", p);
1525                 if (cp) {
1526                         *cp = ':';
1527 #if ENABLE_FEATURE_HTTPD_SET_REMOTE_PORT_TO_ENV
1528                         setenv1("REMOTE_PORT", cp + 1);
1529 #endif
1530                 }
1531         }
1532         setenv1("HTTP_USER_AGENT", user_agent);
1533         if (http_accept)
1534                 setenv1("HTTP_ACCEPT", http_accept);
1535         if (http_accept_language)
1536                 setenv1("HTTP_ACCEPT_LANGUAGE", http_accept_language);
1537         if (post_len)
1538                 putenv(xasprintf("CONTENT_LENGTH=%d", post_len));
1539         if (cookie)
1540                 setenv1("HTTP_COOKIE", cookie);
1541         if (content_type)
1542                 setenv1("CONTENT_TYPE", content_type);
1543 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
1544         if (remoteuser) {
1545                 setenv1("REMOTE_USER", remoteuser);
1546                 putenv((char*)"AUTH_TYPE=Basic");
1547         }
1548 #endif
1549         if (referer)
1550                 setenv1("HTTP_REFERER", referer);
1551         setenv1("HTTP_HOST", host); /* set to "" if NULL */
1552         /* setenv1("SERVER_NAME", safe_gethostname()); - don't do this,
1553          * just run "env SERVER_NAME=xyz httpd ..." instead */
1554
1555         xpiped_pair(fromCgi);
1556         xpiped_pair(toCgi);
1557
1558         pid = vfork();
1559         if (pid < 0) {
1560                 /* TODO: log perror? */
1561                 log_and_exit();
1562         }
1563
1564         if (pid == 0) {
1565                 /* Child process */
1566                 char *argv[3];
1567
1568                 xfunc_error_retval = 242;
1569
1570                 /* NB: close _first_, then move fds! */
1571                 close(toCgi.wr);
1572                 close(fromCgi.rd);
1573                 xmove_fd(toCgi.rd, 0);  /* replace stdin with the pipe */
1574                 xmove_fd(fromCgi.wr, 1);  /* replace stdout with the pipe */
1575                 /* User seeing stderr output can be a security problem.
1576                  * If CGI really wants that, it can always do dup itself. */
1577                 /* dup2(1, 2); */
1578
1579                 /* Chdiring to script's dir */
1580                 script = last_slash;
1581                 if (script != url) { /* paranoia */
1582                         *script = '\0';
1583                         if (chdir(url + 1) != 0) {
1584                                 bb_perror_msg("can't change directory to '%s'", url + 1);
1585                                 goto error_execing_cgi;
1586                         }
1587                         // not needed: *script = '/';
1588                 }
1589                 script++;
1590
1591                 /* set argv[0] to name without path */
1592                 argv[0] = script;
1593                 argv[1] = NULL;
1594
1595 #if ENABLE_FEATURE_HTTPD_CONFIG_WITH_SCRIPT_INTERPR
1596                 {
1597                         char *suffix = strrchr(script, '.');
1598
1599                         if (suffix) {
1600                                 Htaccess *cur;
1601                                 for (cur = script_i; cur; cur = cur->next) {
1602                                         if (strcmp(cur->before_colon + 1, suffix) == 0) {
1603                                                 /* found interpreter name */
1604                                                 argv[0] = cur->after_colon;
1605                                                 argv[1] = script;
1606                                                 argv[2] = NULL;
1607                                                 break;
1608                                         }
1609                                 }
1610                         }
1611                 }
1612 #endif
1613                 /* restore default signal dispositions for CGI process */
1614                 bb_signals(0
1615                         | (1 << SIGCHLD)
1616                         | (1 << SIGPIPE)
1617                         | (1 << SIGHUP)
1618                         , SIG_DFL);
1619
1620                 /* _NOT_ execvp. We do not search PATH. argv[0] is a filename
1621                  * without any dir components and will only match a file
1622                  * in the current directory */
1623                 execv(argv[0], argv);
1624                 if (verbose)
1625                         bb_perror_msg("can't execute '%s'", argv[0]);
1626  error_execing_cgi:
1627                 /* send to stdout
1628                  * (we are CGI here, our stdout is pumped to the net) */
1629                 send_headers_and_exit(HTTP_NOT_FOUND);
1630         } /* end child */
1631
1632         /* Parent process */
1633
1634         /* Restore variables possibly changed by child */
1635         xfunc_error_retval = 0;
1636
1637         /* Pump data */
1638         close(fromCgi.wr);
1639         close(toCgi.rd);
1640         cgi_io_loop_and_exit(fromCgi.rd, toCgi.wr, post_len);
1641 }
1642
1643 #endif          /* FEATURE_HTTPD_CGI */
1644
1645 /*
1646  * Send a file response to a HTTP request, and exit
1647  *
1648  * Parameters:
1649  * const char *url  The requested URL (with leading /).
1650  * what             What to send (headers/body/both).
1651  */
1652 static NOINLINE void send_file_and_exit(const char *url, int what)
1653 {
1654         char *suffix;
1655         int fd;
1656         ssize_t count;
1657
1658         if (content_gzip) {
1659                 /* does <url>.gz exist? Then use it instead */
1660                 char *gzurl = xasprintf("%s.gz", url);
1661                 fd = open(gzurl, O_RDONLY);
1662                 free(gzurl);
1663                 if (fd != -1) {
1664                         struct stat sb;
1665                         fstat(fd, &sb);
1666                         file_size = sb.st_size;
1667                         last_mod = sb.st_mtime;
1668                 } else {
1669                         IF_FEATURE_HTTPD_GZIP(content_gzip = 0;)
1670                         fd = open(url, O_RDONLY);
1671                 }
1672         } else {
1673                 fd = open(url, O_RDONLY);
1674         }
1675         if (fd < 0) {
1676                 if (DEBUG)
1677                         bb_perror_msg("can't open '%s'", url);
1678                 /* Error pages are sent by using send_file_and_exit(SEND_BODY).
1679                  * IOW: it is unsafe to call send_headers_and_exit
1680                  * if what is SEND_BODY! Can recurse! */
1681                 if (what != SEND_BODY)
1682                         send_headers_and_exit(HTTP_NOT_FOUND);
1683                 log_and_exit();
1684         }
1685         /* If you want to know about EPIPE below
1686          * (happens if you abort downloads from local httpd): */
1687         signal(SIGPIPE, SIG_IGN);
1688
1689         /* If not found, default is "application/octet-stream" */
1690         found_mime_type = "application/octet-stream";
1691         suffix = strrchr(url, '.');
1692         if (suffix) {
1693                 static const char suffixTable[] ALIGN1 =
1694                         /* Shorter suffix must be first:
1695                          * ".html.htm" will fail for ".htm"
1696                          */
1697                         ".txt.h.c.cc.cpp\0" "text/plain\0"
1698                         /* .htm line must be after .h line */
1699                         ".htm.html\0" "text/html\0"
1700                         ".jpg.jpeg\0" "image/jpeg\0"
1701                         ".gif\0"      "image/gif\0"
1702                         ".png\0"      "image/png\0"
1703                         /* .css line must be after .c line */
1704                         ".css\0"      "text/css\0"
1705                         ".wav\0"      "audio/wav\0"
1706                         ".avi\0"      "video/x-msvideo\0"
1707                         ".qt.mov\0"   "video/quicktime\0"
1708                         ".mpe.mpeg\0" "video/mpeg\0"
1709                         ".mid.midi\0" "audio/midi\0"
1710                         ".mp3\0"      "audio/mpeg\0"
1711 #if 0  /* unpopular */
1712                         ".au\0"       "audio/basic\0"
1713                         ".pac\0"      "application/x-ns-proxy-autoconfig\0"
1714                         ".vrml.wrl\0" "model/vrml\0"
1715 #endif
1716                         /* compiler adds another "\0" here */
1717                 ;
1718                 Htaccess *cur;
1719
1720                 /* Examine built-in table */
1721                 const char *table = suffixTable;
1722                 const char *table_next;
1723                 for (; *table; table = table_next) {
1724                         const char *try_suffix;
1725                         const char *mime_type;
1726                         mime_type  = table + strlen(table) + 1;
1727                         table_next = mime_type + strlen(mime_type) + 1;
1728                         try_suffix = strstr(table, suffix);
1729                         if (!try_suffix)
1730                                 continue;
1731                         try_suffix += strlen(suffix);
1732                         if (*try_suffix == '\0' || *try_suffix == '.') {
1733                                 found_mime_type = mime_type;
1734                                 break;
1735                         }
1736                         /* Example: strstr(table, ".av") != NULL, but it
1737                          * does not match ".avi" after all and we end up here.
1738                          * The table is arranged so that in this case we know
1739                          * that it can't match anything in the following lines,
1740                          * and we stop the search: */
1741                         break;
1742                 }
1743                 /* ...then user's table */
1744                 for (cur = mime_a; cur; cur = cur->next) {
1745                         if (strcmp(cur->before_colon, suffix) == 0) {
1746                                 found_mime_type = cur->after_colon;
1747                                 break;
1748                         }
1749                 }
1750         }
1751
1752         if (DEBUG)
1753                 bb_error_msg("sending file '%s' content-type: %s",
1754                         url, found_mime_type);
1755
1756 #if ENABLE_FEATURE_HTTPD_RANGES
1757         if (what == SEND_BODY /* err pages and ranges don't mix */
1758          || content_gzip /* we are sending compressed page: can't do ranges */  ///why?
1759         ) {
1760                 range_start = -1;
1761         }
1762         range_len = MAXINT(off_t);
1763         if (range_start >= 0) {
1764                 if (!range_end || range_end > file_size - 1) {
1765                         range_end = file_size - 1;
1766                 }
1767                 if (range_end < range_start
1768                  || lseek(fd, range_start, SEEK_SET) != range_start
1769                 ) {
1770                         lseek(fd, 0, SEEK_SET);
1771                         range_start = -1;
1772                 } else {
1773                         range_len = range_end - range_start + 1;
1774                         send_headers(HTTP_PARTIAL_CONTENT);
1775                         what = SEND_BODY;
1776                 }
1777         }
1778 #endif
1779         if (what & SEND_HEADERS)
1780                 send_headers(HTTP_OK);
1781 #if ENABLE_FEATURE_USE_SENDFILE
1782         {
1783                 off_t offset = range_start;
1784                 while (1) {
1785                         /* sz is rounded down to 64k */
1786                         ssize_t sz = MAXINT(ssize_t) - 0xffff;
1787                         IF_FEATURE_HTTPD_RANGES(if (sz > range_len) sz = range_len;)
1788                         count = sendfile(STDOUT_FILENO, fd, &offset, sz);
1789                         if (count < 0) {
1790                                 if (offset == range_start)
1791                                         break; /* fall back to read/write loop */
1792                                 goto fin;
1793                         }
1794                         IF_FEATURE_HTTPD_RANGES(range_len -= count;)
1795                         if (count == 0 || range_len == 0)
1796                                 log_and_exit();
1797                 }
1798         }
1799 #endif
1800         while ((count = safe_read(fd, iobuf, IOBUF_SIZE)) > 0) {
1801                 ssize_t n;
1802                 IF_FEATURE_HTTPD_RANGES(if (count > range_len) count = range_len;)
1803                 n = full_write(STDOUT_FILENO, iobuf, count);
1804                 if (count != n)
1805                         break;
1806                 IF_FEATURE_HTTPD_RANGES(range_len -= count;)
1807                 if (range_len == 0)
1808                         break;
1809         }
1810         if (count < 0) {
1811  IF_FEATURE_USE_SENDFILE(fin:)
1812                 if (verbose > 1)
1813                         bb_perror_msg("error");
1814         }
1815         log_and_exit();
1816 }
1817
1818 static int checkPermIP(void)
1819 {
1820         Htaccess_IP *cur;
1821
1822         for (cur = ip_a_d; cur; cur = cur->next) {
1823 #if DEBUG
1824                 fprintf(stderr,
1825                         "checkPermIP: '%s' ? '%u.%u.%u.%u/%u.%u.%u.%u'\n",
1826                         rmt_ip_str,
1827                         (unsigned char)(cur->ip >> 24),
1828                         (unsigned char)(cur->ip >> 16),
1829                         (unsigned char)(cur->ip >> 8),
1830                         (unsigned char)(cur->ip),
1831                         (unsigned char)(cur->mask >> 24),
1832                         (unsigned char)(cur->mask >> 16),
1833                         (unsigned char)(cur->mask >> 8),
1834                         (unsigned char)(cur->mask)
1835                 );
1836 #endif
1837                 if ((rmt_ip & cur->mask) == cur->ip)
1838                         return (cur->allow_deny == 'A'); /* A -> 1 */
1839         }
1840
1841         return !flg_deny_all; /* depends on whether we saw "D:*" */
1842 }
1843
1844 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
1845
1846 # if ENABLE_PAM
1847 struct pam_userinfo {
1848         const char *name;
1849         const char *pw;
1850 };
1851
1852 static int pam_talker(int num_msg,
1853                 const struct pam_message **msg,
1854                 struct pam_response **resp,
1855                 void *appdata_ptr)
1856 {
1857         int i;
1858         struct pam_userinfo *userinfo = (struct pam_userinfo *) appdata_ptr;
1859         struct pam_response *response;
1860
1861         if (!resp || !msg || !userinfo)
1862                 return PAM_CONV_ERR;
1863
1864         /* allocate memory to store response */
1865         response = xzalloc(num_msg * sizeof(*response));
1866
1867         /* copy values */
1868         for (i = 0; i < num_msg; i++) {
1869                 const char *s;
1870
1871                 switch (msg[i]->msg_style) {
1872                 case PAM_PROMPT_ECHO_ON:
1873                         s = userinfo->name;
1874                         break;
1875                 case PAM_PROMPT_ECHO_OFF:
1876                         s = userinfo->pw;
1877                         break;
1878                 case PAM_ERROR_MSG:
1879                 case PAM_TEXT_INFO:
1880                         s = "";
1881                         break;
1882                 default:
1883                         free(response);
1884                         return PAM_CONV_ERR;
1885                 }
1886                 response[i].resp = xstrdup(s);
1887                 if (PAM_SUCCESS != 0)
1888                         response[i].resp_retcode = PAM_SUCCESS;
1889         }
1890         *resp = response;
1891         return PAM_SUCCESS;
1892 }
1893 # endif
1894
1895 /*
1896  * Config file entries are of the form "/<path>:<user>:<passwd>".
1897  * If config file has no prefix match for path, access is allowed.
1898  *
1899  * path                 The file path
1900  * user_and_passwd      "user:passwd" to validate
1901  *
1902  * Returns 1 if user_and_passwd is OK.
1903  */
1904 static int check_user_passwd(const char *path, char *user_and_passwd)
1905 {
1906         Htaccess *cur;
1907         const char *prev = NULL;
1908
1909         for (cur = g_auth; cur; cur = cur->next) {
1910                 const char *dir_prefix;
1911                 size_t len;
1912                 int r;
1913
1914                 dir_prefix = cur->before_colon;
1915
1916                 /* WHY? */
1917                 /* If already saw a match, don't accept other different matches */
1918                 if (prev && strcmp(prev, dir_prefix) != 0)
1919                         continue;
1920
1921                 if (DEBUG)
1922                         fprintf(stderr, "checkPerm: '%s' ? '%s'\n", dir_prefix, user_and_passwd);
1923
1924                 /* If it's not a prefix match, continue searching */
1925                 len = strlen(dir_prefix);
1926                 if (len != 1 /* dir_prefix "/" matches all, don't need to check */
1927                  && (strncmp(dir_prefix, path, len) != 0
1928                     || (path[len] != '/' && path[len] != '\0')
1929                     )
1930                 ) {
1931                         continue;
1932                 }
1933
1934                 /* Path match found */
1935                 prev = dir_prefix;
1936
1937                 if (ENABLE_FEATURE_HTTPD_AUTH_MD5) {
1938                         char *colon_after_user;
1939                         const char *passwd;
1940 # if ENABLE_FEATURE_SHADOWPASSWDS && !ENABLE_PAM
1941                         char sp_buf[256];
1942 # endif
1943
1944                         colon_after_user = strchr(user_and_passwd, ':');
1945                         if (!colon_after_user)
1946                                 goto bad_input;
1947
1948                         /* compare "user:" */
1949                         if (cur->after_colon[0] != '*'
1950                          && strncmp(cur->after_colon, user_and_passwd,
1951                                         colon_after_user - user_and_passwd + 1) != 0
1952                         ) {
1953                                 continue;
1954                         }
1955                         /* this cfg entry is '*' or matches username from peer */
1956
1957                         passwd = strchr(cur->after_colon, ':');
1958                         if (!passwd)
1959                                 goto bad_input;
1960                         passwd++;
1961                         if (passwd[0] == '*') {
1962 # if ENABLE_PAM
1963                                 struct pam_userinfo userinfo;
1964                                 struct pam_conv conv_info = { &pam_talker, (void *) &userinfo };
1965                                 pam_handle_t *pamh;
1966
1967                                 *colon_after_user = '\0';
1968                                 userinfo.name = user_and_passwd;
1969                                 userinfo.pw = colon_after_user + 1;
1970                                 r = pam_start("httpd", user_and_passwd, &conv_info, &pamh) != PAM_SUCCESS;
1971                                 if (r == 0) {
1972                                         r = pam_authenticate(pamh, PAM_DISALLOW_NULL_AUTHTOK) != PAM_SUCCESS
1973                                          || pam_acct_mgmt(pamh, PAM_DISALLOW_NULL_AUTHTOK)    != PAM_SUCCESS
1974                                         ;
1975                                         pam_end(pamh, PAM_SUCCESS);
1976                                 }
1977                                 *colon_after_user = ':';
1978                                 goto end_check_passwd;
1979 # else
1980 #  if ENABLE_FEATURE_SHADOWPASSWDS
1981                                 /* Using _r function to avoid pulling in static buffers */
1982                                 struct spwd spw;
1983 #  endif
1984                                 struct passwd *pw;
1985
1986                                 *colon_after_user = '\0';
1987                                 pw = getpwnam(user_and_passwd);
1988                                 *colon_after_user = ':';
1989                                 if (!pw || !pw->pw_passwd)
1990                                         continue;
1991                                 passwd = pw->pw_passwd;
1992 #  if ENABLE_FEATURE_SHADOWPASSWDS
1993                                 if ((passwd[0] == 'x' || passwd[0] == '*') && !passwd[1]) {
1994                                         /* getspnam_r may return 0 yet set result to NULL.
1995                                          * At least glibc 2.4 does this. Be extra paranoid here. */
1996                                         struct spwd *result = NULL;
1997                                         r = getspnam_r(pw->pw_name, &spw, sp_buf, sizeof(sp_buf), &result);
1998                                         if (r == 0 && result)
1999                                                 passwd = result->sp_pwdp;
2000                                 }
2001 #  endif
2002                                 /* In this case, passwd is ALWAYS encrypted:
2003                                  * it came from /etc/passwd or /etc/shadow!
2004                                  */
2005                                 goto check_encrypted;
2006 # endif /* ENABLE_PAM */
2007                         }
2008                         /* Else: passwd is from httpd.conf, it is either plaintext or encrypted */
2009
2010                         if (passwd[0] == '$' && isdigit(passwd[1])) {
2011                                 char *encrypted;
2012 # if !ENABLE_PAM
2013  check_encrypted:
2014 # endif
2015                                 /* encrypt pwd from peer and check match with local one */
2016                                 encrypted = pw_encrypt(
2017                                         /* pwd (from peer): */  colon_after_user + 1,
2018                                         /* salt: */ passwd,
2019                                         /* cleanup: */ 0
2020                                 );
2021                                 r = strcmp(encrypted, passwd);
2022                                 free(encrypted);
2023                         } else {
2024                                 /* local passwd is from httpd.conf and it's plaintext */
2025                                 r = strcmp(colon_after_user + 1, passwd);
2026                         }
2027                         goto end_check_passwd;
2028                 }
2029  bad_input:
2030                 /* Comparing plaintext "user:pass" in one go */
2031                 r = strcmp(cur->after_colon, user_and_passwd);
2032  end_check_passwd:
2033                 if (r == 0) {
2034                         remoteuser = xstrndup(user_and_passwd,
2035                                 strchrnul(user_and_passwd, ':') - user_and_passwd
2036                         );
2037                         return 1; /* Ok */
2038                 }
2039         } /* for */
2040
2041         /* 0(bad) if prev is set: matches were found but passwd was wrong */
2042         return (prev == NULL);
2043 }
2044 #endif  /* FEATURE_HTTPD_BASIC_AUTH */
2045
2046 #if ENABLE_FEATURE_HTTPD_PROXY
2047 static Htaccess_Proxy *find_proxy_entry(const char *url)
2048 {
2049         Htaccess_Proxy *p;
2050         for (p = proxy; p; p = p->next) {
2051                 if (is_prefixed_with(url, p->url_from))
2052                         return p;
2053         }
2054         return NULL;
2055 }
2056 #endif
2057
2058 /*
2059  * Handle timeouts
2060  */
2061 static void send_REQUEST_TIMEOUT_and_exit(int sig) NORETURN;
2062 static void send_REQUEST_TIMEOUT_and_exit(int sig UNUSED_PARAM)
2063 {
2064         send_headers_and_exit(HTTP_REQUEST_TIMEOUT);
2065 }
2066
2067 /*
2068  * Handle an incoming http request and exit.
2069  */
2070 static void handle_incoming_and_exit(const len_and_sockaddr *fromAddr) NORETURN;
2071 static void handle_incoming_and_exit(const len_and_sockaddr *fromAddr)
2072 {
2073         static const char request_GET[] ALIGN1 = "GET";
2074         struct stat sb;
2075         char *urlcopy;
2076         char *urlp;
2077         char *tptr;
2078 #if ENABLE_FEATURE_HTTPD_CGI
2079         static const char request_HEAD[] ALIGN1 = "HEAD";
2080         const char *prequest;
2081         char *cookie = NULL;
2082         char *content_type = NULL;
2083         unsigned long length = 0;
2084 #elif ENABLE_FEATURE_HTTPD_PROXY
2085 #define prequest request_GET
2086         unsigned long length = 0;
2087 #endif
2088 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
2089         smallint authorized = -1;
2090 #endif
2091         smallint ip_allowed;
2092         char http_major_version;
2093 #if ENABLE_FEATURE_HTTPD_PROXY
2094         char http_minor_version;
2095         char *header_buf = header_buf; /* for gcc */
2096         char *header_ptr = header_ptr;
2097         Htaccess_Proxy *proxy_entry;
2098 #endif
2099
2100         /* Allocation of iobuf is postponed until now
2101          * (IOW, server process doesn't need to waste 8k) */
2102         iobuf = xmalloc(IOBUF_SIZE);
2103
2104         rmt_ip = 0;
2105         if (fromAddr->u.sa.sa_family == AF_INET) {
2106                 rmt_ip = ntohl(fromAddr->u.sin.sin_addr.s_addr);
2107         }
2108 #if ENABLE_FEATURE_IPV6
2109         if (fromAddr->u.sa.sa_family == AF_INET6
2110          && fromAddr->u.sin6.sin6_addr.s6_addr32[0] == 0
2111          && fromAddr->u.sin6.sin6_addr.s6_addr32[1] == 0
2112          && ntohl(fromAddr->u.sin6.sin6_addr.s6_addr32[2]) == 0xffff)
2113                 rmt_ip = ntohl(fromAddr->u.sin6.sin6_addr.s6_addr32[3]);
2114 #endif
2115         if (ENABLE_FEATURE_HTTPD_CGI || DEBUG || verbose) {
2116                 /* NB: can be NULL (user runs httpd -i by hand?) */
2117                 rmt_ip_str = xmalloc_sockaddr2dotted(&fromAddr->u.sa);
2118         }
2119         if (verbose) {
2120                 /* this trick makes -v logging much simpler */
2121                 if (rmt_ip_str)
2122                         applet_name = rmt_ip_str;
2123                 if (verbose > 2)
2124                         bb_error_msg("connected");
2125         }
2126
2127         /* Install timeout handler. get_line() needs it. */
2128         signal(SIGALRM, send_REQUEST_TIMEOUT_and_exit);
2129
2130         if (!get_line()) /* EOF or error or empty line */
2131                 send_headers_and_exit(HTTP_BAD_REQUEST);
2132
2133         /* Determine type of request (GET/POST) */
2134         // rfc2616: method and URI is separated by exactly one space
2135         //urlp = strpbrk(iobuf, " \t"); - no, tab isn't allowed
2136         urlp = strchr(iobuf, ' ');
2137         if (urlp == NULL)
2138                 send_headers_and_exit(HTTP_BAD_REQUEST);
2139         *urlp++ = '\0';
2140 #if ENABLE_FEATURE_HTTPD_CGI
2141         prequest = request_GET;
2142         if (strcasecmp(iobuf, prequest) != 0) {
2143                 prequest = request_HEAD;
2144                 if (strcasecmp(iobuf, prequest) != 0) {
2145                         prequest = "POST";
2146                         if (strcasecmp(iobuf, prequest) != 0)
2147                                 send_headers_and_exit(HTTP_NOT_IMPLEMENTED);
2148                 }
2149         }
2150 #else
2151         if (strcasecmp(iobuf, request_GET) != 0)
2152                 send_headers_and_exit(HTTP_NOT_IMPLEMENTED);
2153 #endif
2154         // rfc2616: method and URI is separated by exactly one space
2155         //urlp = skip_whitespace(urlp); - should not be necessary
2156         if (urlp[0] != '/')
2157                 send_headers_and_exit(HTTP_BAD_REQUEST);
2158
2159         /* Find end of URL and parse HTTP version, if any */
2160         http_major_version = '0';
2161         IF_FEATURE_HTTPD_PROXY(http_minor_version = '0';)
2162         tptr = strchrnul(urlp, ' ');
2163         /* Is it " HTTP/"? */
2164         if (tptr[0] && strncmp(tptr + 1, HTTP_200, 5) == 0) {
2165                 http_major_version = tptr[6];
2166                 IF_FEATURE_HTTPD_PROXY(http_minor_version = tptr[8];)
2167         }
2168         *tptr = '\0';
2169
2170         /* Copy URL from after "GET "/"POST " to stack-allocated char[] */
2171         urlcopy = alloca((tptr - urlp) + 2 + strlen(index_page));
2172         /*if (urlcopy == NULL)
2173          *      send_headers_and_exit(HTTP_INTERNAL_SERVER_ERROR);*/
2174         strcpy(urlcopy, urlp);
2175         /* NB: urlcopy ptr is never changed after this */
2176
2177         /* Extract url args if present */
2178         /* g_query = NULL; - already is */
2179         tptr = strchr(urlcopy, '?');
2180         if (tptr) {
2181                 *tptr++ = '\0';
2182                 g_query = tptr;
2183         }
2184
2185         /* Decode URL escape sequences */
2186         tptr = percent_decode_in_place(urlcopy, /*strict:*/ 1);
2187         if (tptr == NULL)
2188                 send_headers_and_exit(HTTP_BAD_REQUEST);
2189         if (tptr == urlcopy + 1) {
2190                 /* '/' or NUL is encoded */
2191                 send_headers_and_exit(HTTP_NOT_FOUND);
2192         }
2193
2194         /* Canonicalize path */
2195         /* Algorithm stolen from libbb bb_simplify_path(),
2196          * but don't strdup, retain trailing slash, protect root */
2197         urlp = tptr = urlcopy;
2198         for (;;) {
2199                 if (*urlp == '/') {
2200                         /* skip duplicate (or initial) slash */
2201                         if (*tptr == '/') {
2202                                 goto next_char;
2203                         }
2204                         if (*tptr == '.') {
2205                                 if (tptr[1] == '.' && (tptr[2] == '/' || tptr[2] == '\0')) {
2206                                         /* "..": be careful */
2207                                         /* protect root */
2208                                         if (urlp == urlcopy)
2209                                                 send_headers_and_exit(HTTP_BAD_REQUEST);
2210                                         /* omit previous dir */
2211                                         while (*--urlp != '/')
2212                                                 continue;
2213                                         /* skip to "./" or ".<NUL>" */
2214                                         tptr++;
2215                                 }
2216                                 if (tptr[1] == '/' || tptr[1] == '\0') {
2217                                         /* skip extra "/./" */
2218                                         goto next_char;
2219                                 }
2220                         }
2221                 }
2222                 *++urlp = *tptr;
2223                 if (*urlp == '\0')
2224                         break;
2225  next_char:
2226                 tptr++;
2227         }
2228
2229         /* If URL is a directory, add '/' */
2230         if (urlp[-1] != '/') {
2231                 if (is_directory(urlcopy + 1, /*followlinks:*/ 1)) {
2232                         found_moved_temporarily = urlcopy;
2233                 }
2234         }
2235
2236         /* Log it */
2237         if (verbose > 1)
2238                 bb_error_msg("url:%s", urlcopy);
2239
2240         tptr = urlcopy;
2241         ip_allowed = checkPermIP();
2242         while (ip_allowed && (tptr = strchr(tptr + 1, '/')) != NULL) {
2243                 /* have path1/path2 */
2244                 *tptr = '\0';
2245                 if (is_directory(urlcopy + 1, /*followlinks:*/ 1)) {
2246                         /* may have subdir config */
2247                         parse_conf(urlcopy + 1, SUBDIR_PARSE);
2248                         ip_allowed = checkPermIP();
2249                 }
2250                 *tptr = '/';
2251         }
2252
2253 #if ENABLE_FEATURE_HTTPD_PROXY
2254         proxy_entry = find_proxy_entry(urlcopy);
2255         if (proxy_entry)
2256                 header_buf = header_ptr = xmalloc(IOBUF_SIZE);
2257 #endif
2258
2259         if (http_major_version >= '0') {
2260                 /* Request was with "... HTTP/nXXX", and n >= 0 */
2261
2262                 /* Read until blank line */
2263                 while (1) {
2264                         if (!get_line())
2265                                 break; /* EOF or error or empty line */
2266                         if (DEBUG)
2267                                 bb_error_msg("header: '%s'", iobuf);
2268
2269 #if ENABLE_FEATURE_HTTPD_PROXY
2270                         /* We need 2 more bytes for yet another "\r\n" -
2271                          * see near fdprintf(proxy_fd...) further below */
2272                         if (proxy_entry && (header_ptr - header_buf) < IOBUF_SIZE - 2) {
2273                                 int len = strlen(iobuf);
2274                                 if (len > IOBUF_SIZE - (header_ptr - header_buf) - 4)
2275                                         len = IOBUF_SIZE - (header_ptr - header_buf) - 4;
2276                                 memcpy(header_ptr, iobuf, len);
2277                                 header_ptr += len;
2278                                 header_ptr[0] = '\r';
2279                                 header_ptr[1] = '\n';
2280                                 header_ptr += 2;
2281                         }
2282 #endif
2283
2284 #if ENABLE_FEATURE_HTTPD_CGI || ENABLE_FEATURE_HTTPD_PROXY
2285                         /* Try and do our best to parse more lines */
2286                         if ((STRNCASECMP(iobuf, "Content-length:") == 0)) {
2287                                 /* extra read only for POST */
2288                                 if (prequest != request_GET
2289 # if ENABLE_FEATURE_HTTPD_CGI
2290                                  && prequest != request_HEAD
2291 # endif
2292                                 ) {
2293                                         tptr = skip_whitespace(iobuf + sizeof("Content-length:") - 1);
2294                                         if (!tptr[0])
2295                                                 send_headers_and_exit(HTTP_BAD_REQUEST);
2296                                         /* not using strtoul: it ignores leading minus! */
2297                                         length = bb_strtou(tptr, NULL, 10);
2298                                         /* length is "ulong", but we need to pass it to int later */
2299                                         if (errno || length > INT_MAX)
2300                                                 send_headers_and_exit(HTTP_BAD_REQUEST);
2301                                 }
2302                         }
2303 #endif
2304 #if ENABLE_FEATURE_HTTPD_CGI
2305                         else if (STRNCASECMP(iobuf, "Cookie:") == 0) {
2306                                 cookie = xstrdup(skip_whitespace(iobuf + sizeof("Cookie:")-1));
2307                         } else if (STRNCASECMP(iobuf, "Content-Type:") == 0) {
2308                                 content_type = xstrdup(skip_whitespace(iobuf + sizeof("Content-Type:")-1));
2309                         } else if (STRNCASECMP(iobuf, "Referer:") == 0) {
2310                                 referer = xstrdup(skip_whitespace(iobuf + sizeof("Referer:")-1));
2311                         } else if (STRNCASECMP(iobuf, "User-Agent:") == 0) {
2312                                 user_agent = xstrdup(skip_whitespace(iobuf + sizeof("User-Agent:")-1));
2313                         } else if (STRNCASECMP(iobuf, "Host:") == 0) {
2314                                 host = xstrdup(skip_whitespace(iobuf + sizeof("Host:")-1));
2315                         } else if (STRNCASECMP(iobuf, "Accept:") == 0) {
2316                                 http_accept = xstrdup(skip_whitespace(iobuf + sizeof("Accept:")-1));
2317                         } else if (STRNCASECMP(iobuf, "Accept-Language:") == 0) {
2318                                 http_accept_language = xstrdup(skip_whitespace(iobuf + sizeof("Accept-Language:")-1));
2319                         }
2320 #endif
2321 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
2322                         if (STRNCASECMP(iobuf, "Authorization:") == 0) {
2323                                 /* We only allow Basic credentials.
2324                                  * It shows up as "Authorization: Basic <user>:<passwd>" where
2325                                  * "<user>:<passwd>" is base64 encoded.
2326                                  */
2327                                 tptr = skip_whitespace(iobuf + sizeof("Authorization:")-1);
2328                                 if (STRNCASECMP(tptr, "Basic") != 0)
2329                                         continue;
2330                                 tptr += sizeof("Basic")-1;
2331                                 /* decodeBase64() skips whitespace itself */
2332                                 decodeBase64(tptr);
2333                                 authorized = check_user_passwd(urlcopy, tptr);
2334                         }
2335 #endif
2336 #if ENABLE_FEATURE_HTTPD_RANGES
2337                         if (STRNCASECMP(iobuf, "Range:") == 0) {
2338                                 /* We know only bytes=NNN-[MMM] */
2339                                 char *s = skip_whitespace(iobuf + sizeof("Range:")-1);
2340                                 if (is_prefixed_with(s, "bytes=") == 0) {
2341                                         s += sizeof("bytes=")-1;
2342                                         range_start = BB_STRTOOFF(s, &s, 10);
2343                                         if (s[0] != '-' || range_start < 0) {
2344                                                 range_start = -1;
2345                                         } else if (s[1]) {
2346                                                 range_end = BB_STRTOOFF(s+1, NULL, 10);
2347                                                 if (errno || range_end < range_start)
2348                                                         range_start = -1;
2349                                         }
2350                                 }
2351                         }
2352 #endif
2353 #if ENABLE_FEATURE_HTTPD_GZIP
2354                         if (STRNCASECMP(iobuf, "Accept-Encoding:") == 0) {
2355                                 /* Note: we do not support "gzip;q=0"
2356                                  * method of _disabling_ gzip
2357                                  * delivery. No one uses that, though */
2358                                 const char *s = strstr(iobuf, "gzip");
2359                                 if (s) {
2360                                         // want more thorough checks?
2361                                         //if (s[-1] == ' '
2362                                         // || s[-1] == ','
2363                                         // || s[-1] == ':'
2364                                         //) {
2365                                                 content_gzip = 1;
2366                                         //}
2367                                 }
2368                         }
2369 #endif
2370                 } /* while extra header reading */
2371         }
2372
2373         /* We are done reading headers, disable peer timeout */
2374         alarm(0);
2375
2376         if (strcmp(bb_basename(urlcopy), HTTPD_CONF) == 0 || !ip_allowed) {
2377                 /* protect listing [/path]/httpd.conf or IP deny */
2378                 send_headers_and_exit(HTTP_FORBIDDEN);
2379         }
2380
2381 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
2382         /* Case: no "Authorization:" was seen, but page might require passwd.
2383          * Check that with dummy user:pass */
2384         if (authorized < 0)
2385                 authorized = check_user_passwd(urlcopy, (char *) "");
2386         if (!authorized)
2387                 send_headers_and_exit(HTTP_UNAUTHORIZED);
2388 #endif
2389
2390         if (found_moved_temporarily) {
2391                 send_headers_and_exit(HTTP_MOVED_TEMPORARILY);
2392         }
2393
2394 #if ENABLE_FEATURE_HTTPD_PROXY
2395         if (proxy_entry != NULL) {
2396                 int proxy_fd;
2397                 len_and_sockaddr *lsa;
2398
2399                 proxy_fd = socket(AF_INET, SOCK_STREAM, 0);
2400                 if (proxy_fd < 0)
2401                         send_headers_and_exit(HTTP_INTERNAL_SERVER_ERROR);
2402                 lsa = host2sockaddr(proxy_entry->host_port, 80);
2403                 if (lsa == NULL)
2404                         send_headers_and_exit(HTTP_INTERNAL_SERVER_ERROR);
2405                 if (connect(proxy_fd, &lsa->u.sa, lsa->len) < 0)
2406                         send_headers_and_exit(HTTP_INTERNAL_SERVER_ERROR);
2407                 fdprintf(proxy_fd, "%s %s%s%s%s HTTP/%c.%c\r\n",
2408                                 prequest, /* GET or POST */
2409                                 proxy_entry->url_to, /* url part 1 */
2410                                 urlcopy + strlen(proxy_entry->url_from), /* url part 2 */
2411                                 (g_query ? "?" : ""), /* "?" (maybe) */
2412                                 (g_query ? g_query : ""), /* query string (maybe) */
2413                                 http_major_version, http_minor_version);
2414                 header_ptr[0] = '\r';
2415                 header_ptr[1] = '\n';
2416                 header_ptr += 2;
2417                 write(proxy_fd, header_buf, header_ptr - header_buf);
2418                 free(header_buf); /* on the order of 8k, free it */
2419                 cgi_io_loop_and_exit(proxy_fd, proxy_fd, length);
2420         }
2421 #endif
2422
2423         tptr = urlcopy + 1;      /* skip first '/' */
2424
2425 #if ENABLE_FEATURE_HTTPD_CGI
2426         if (is_prefixed_with(tptr, "cgi-bin/")) {
2427                 if (tptr[8] == '\0') {
2428                         /* protect listing "cgi-bin/" */
2429                         send_headers_and_exit(HTTP_FORBIDDEN);
2430                 }
2431                 send_cgi_and_exit(urlcopy, urlcopy, prequest, length, cookie, content_type);
2432         }
2433 #endif
2434
2435         if (urlp[-1] == '/') {
2436                 /* When index_page string is appended to <dir>/ URL, it overwrites
2437                  * the query string. If we fall back to call /cgi-bin/index.cgi,
2438                  * query string would be lost and not available to the CGI.
2439                  * Work around it by making a deep copy.
2440                  */
2441                 if (ENABLE_FEATURE_HTTPD_CGI)
2442                         g_query = xstrdup(g_query); /* ok for NULL too */
2443                 strcpy(urlp, index_page);
2444         }
2445         if (stat(tptr, &sb) == 0) {
2446 #if ENABLE_FEATURE_HTTPD_CONFIG_WITH_SCRIPT_INTERPR
2447                 char *suffix = strrchr(tptr, '.');
2448                 if (suffix) {
2449                         Htaccess *cur;
2450                         for (cur = script_i; cur; cur = cur->next) {
2451                                 if (strcmp(cur->before_colon + 1, suffix) == 0) {
2452                                         send_cgi_and_exit(urlcopy, urlcopy, prequest, length, cookie, content_type);
2453                                 }
2454                         }
2455                 }
2456 #endif
2457                 file_size = sb.st_size;
2458                 last_mod = sb.st_mtime;
2459         }
2460 #if ENABLE_FEATURE_HTTPD_CGI
2461         else if (urlp[-1] == '/') {
2462                 /* It's a dir URL and there is no index.html
2463                  * Try cgi-bin/index.cgi */
2464                 if (access("/cgi-bin/index.cgi"+1, X_OK) == 0) {
2465                         urlp[0] = '\0'; /* remove index_page */
2466                         send_cgi_and_exit("/cgi-bin/index.cgi", urlcopy, prequest, length, cookie, content_type);
2467                 }
2468         }
2469         /* else fall through to send_file, it errors out if open fails: */
2470
2471         if (prequest != request_GET && prequest != request_HEAD) {
2472                 /* POST for files does not make sense */
2473                 send_headers_and_exit(HTTP_NOT_IMPLEMENTED);
2474         }
2475         send_file_and_exit(tptr,
2476                 (prequest != request_HEAD ? SEND_HEADERS_AND_BODY : SEND_HEADERS)
2477         );
2478 #else
2479         send_file_and_exit(tptr, SEND_HEADERS_AND_BODY);
2480 #endif
2481 }
2482
2483 /*
2484  * The main http server function.
2485  * Given a socket, listen for new connections and farm out
2486  * the processing as a [v]forked process.
2487  * Never returns.
2488  */
2489 #if BB_MMU
2490 static void mini_httpd(int server_socket) NORETURN;
2491 static void mini_httpd(int server_socket)
2492 {
2493         /* NB: it's best to not use xfuncs in this loop before fork().
2494          * Otherwise server may die on transient errors (temporary
2495          * out-of-memory condition, etc), which is Bad(tm).
2496          * Try to do any dangerous calls after fork.
2497          */
2498         while (1) {
2499                 int n;
2500                 len_and_sockaddr fromAddr;
2501
2502                 /* Wait for connections... */
2503                 fromAddr.len = LSA_SIZEOF_SA;
2504                 n = accept(server_socket, &fromAddr.u.sa, &fromAddr.len);
2505                 if (n < 0)
2506                         continue;
2507
2508                 /* set the KEEPALIVE option to cull dead connections */
2509                 setsockopt_keepalive(n);
2510
2511                 if (fork() == 0) {
2512                         /* child */
2513                         /* Do not reload config on HUP */
2514                         signal(SIGHUP, SIG_IGN);
2515                         close(server_socket);
2516                         xmove_fd(n, 0);
2517                         xdup2(0, 1);
2518
2519                         handle_incoming_and_exit(&fromAddr);
2520                 }
2521                 /* parent, or fork failed */
2522                 close(n);
2523         } /* while (1) */
2524         /* never reached */
2525 }
2526 #else
2527 static void mini_httpd_nommu(int server_socket, int argc, char **argv) NORETURN;
2528 static void mini_httpd_nommu(int server_socket, int argc, char **argv)
2529 {
2530         char *argv_copy[argc + 2];
2531
2532         argv_copy[0] = argv[0];
2533         argv_copy[1] = (char*)"-i";
2534         memcpy(&argv_copy[2], &argv[1], argc * sizeof(argv[0]));
2535
2536         /* NB: it's best to not use xfuncs in this loop before vfork().
2537          * Otherwise server may die on transient errors (temporary
2538          * out-of-memory condition, etc), which is Bad(tm).
2539          * Try to do any dangerous calls after fork.
2540          */
2541         while (1) {
2542                 int n;
2543                 len_and_sockaddr fromAddr;
2544
2545                 /* Wait for connections... */
2546                 fromAddr.len = LSA_SIZEOF_SA;
2547                 n = accept(server_socket, &fromAddr.u.sa, &fromAddr.len);
2548                 if (n < 0)
2549                         continue;
2550
2551                 /* set the KEEPALIVE option to cull dead connections */
2552                 setsockopt_keepalive(n);
2553
2554                 if (vfork() == 0) {
2555                         /* child */
2556                         /* Do not reload config on HUP */
2557                         signal(SIGHUP, SIG_IGN);
2558                         close(server_socket);
2559                         xmove_fd(n, 0);
2560                         xdup2(0, 1);
2561
2562                         /* Run a copy of ourself in inetd mode */
2563                         re_exec(argv_copy);
2564                 }
2565                 argv_copy[0][0] &= 0x7f;
2566                 /* parent, or vfork failed */
2567                 close(n);
2568         } /* while (1) */
2569         /* never reached */
2570 }
2571 #endif
2572
2573 /*
2574  * Process a HTTP connection on stdin/out.
2575  * Never returns.
2576  */
2577 static void mini_httpd_inetd(void) NORETURN;
2578 static void mini_httpd_inetd(void)
2579 {
2580         len_and_sockaddr fromAddr;
2581
2582         memset(&fromAddr, 0, sizeof(fromAddr));
2583         fromAddr.len = LSA_SIZEOF_SA;
2584         /* NB: can fail if user runs it by hand and types in http cmds */
2585         getpeername(0, &fromAddr.u.sa, &fromAddr.len);
2586         handle_incoming_and_exit(&fromAddr);
2587 }
2588
2589 static void sighup_handler(int sig UNUSED_PARAM)
2590 {
2591         parse_conf(DEFAULT_PATH_HTTPD_CONF, SIGNALED_PARSE);
2592 }
2593
2594 enum {
2595         c_opt_config_file = 0,
2596         d_opt_decode_url,
2597         h_opt_home_httpd,
2598         IF_FEATURE_HTTPD_ENCODE_URL_STR(e_opt_encode_url,)
2599         IF_FEATURE_HTTPD_BASIC_AUTH(    r_opt_realm     ,)
2600         IF_FEATURE_HTTPD_AUTH_MD5(      m_opt_md5       ,)
2601         IF_FEATURE_HTTPD_SETUID(        u_opt_setuid    ,)
2602         p_opt_port      ,
2603         p_opt_inetd     ,
2604         p_opt_foreground,
2605         p_opt_verbose   ,
2606         OPT_CONFIG_FILE = 1 << c_opt_config_file,
2607         OPT_DECODE_URL  = 1 << d_opt_decode_url,
2608         OPT_HOME_HTTPD  = 1 << h_opt_home_httpd,
2609         OPT_ENCODE_URL  = IF_FEATURE_HTTPD_ENCODE_URL_STR((1 << e_opt_encode_url)) + 0,
2610         OPT_REALM       = IF_FEATURE_HTTPD_BASIC_AUTH(    (1 << r_opt_realm     )) + 0,
2611         OPT_MD5         = IF_FEATURE_HTTPD_AUTH_MD5(      (1 << m_opt_md5       )) + 0,
2612         OPT_SETUID      = IF_FEATURE_HTTPD_SETUID(        (1 << u_opt_setuid    )) + 0,
2613         OPT_PORT        = 1 << p_opt_port,
2614         OPT_INETD       = 1 << p_opt_inetd,
2615         OPT_FOREGROUND  = 1 << p_opt_foreground,
2616         OPT_VERBOSE     = 1 << p_opt_verbose,
2617 };
2618
2619
2620 int httpd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
2621 int httpd_main(int argc UNUSED_PARAM, char **argv)
2622 {
2623         int server_socket = server_socket; /* for gcc */
2624         unsigned opt;
2625         char *url_for_decode;
2626         IF_FEATURE_HTTPD_ENCODE_URL_STR(const char *url_for_encode;)
2627         IF_FEATURE_HTTPD_SETUID(const char *s_ugid = NULL;)
2628         IF_FEATURE_HTTPD_SETUID(struct bb_uidgid_t ugid;)
2629         IF_FEATURE_HTTPD_AUTH_MD5(const char *pass;)
2630
2631         INIT_G();
2632
2633 #if ENABLE_LOCALE_SUPPORT
2634         /* Undo busybox.c: we want to speak English in http (dates etc) */
2635         setlocale(LC_TIME, "C");
2636 #endif
2637
2638         home_httpd = xrealloc_getcwd_or_warn(NULL);
2639         /* -v counts, -i implies -f */
2640         opt_complementary = "vv:if";
2641         /* We do not "absolutize" path given by -h (home) opt.
2642          * If user gives relative path in -h,
2643          * $SCRIPT_FILENAME will not be set. */
2644         opt = getopt32(argv, "c:d:h:"
2645                         IF_FEATURE_HTTPD_ENCODE_URL_STR("e:")
2646                         IF_FEATURE_HTTPD_BASIC_AUTH("r:")
2647                         IF_FEATURE_HTTPD_AUTH_MD5("m:")
2648                         IF_FEATURE_HTTPD_SETUID("u:")
2649                         "p:ifv",
2650                         &opt_c_configFile, &url_for_decode, &home_httpd
2651                         IF_FEATURE_HTTPD_ENCODE_URL_STR(, &url_for_encode)
2652                         IF_FEATURE_HTTPD_BASIC_AUTH(, &g_realm)
2653                         IF_FEATURE_HTTPD_AUTH_MD5(, &pass)
2654                         IF_FEATURE_HTTPD_SETUID(, &s_ugid)
2655                         , &bind_addr_or_port
2656                         , &verbose
2657                 );
2658         if (opt & OPT_DECODE_URL) {
2659                 fputs(percent_decode_in_place(url_for_decode, /*strict:*/ 0), stdout);
2660                 return 0;
2661         }
2662 #if ENABLE_FEATURE_HTTPD_ENCODE_URL_STR
2663         if (opt & OPT_ENCODE_URL) {
2664                 fputs(encodeString(url_for_encode), stdout);
2665                 return 0;
2666         }
2667 #endif
2668 #if ENABLE_FEATURE_HTTPD_AUTH_MD5
2669         if (opt & OPT_MD5) {
2670                 char salt[sizeof("$1$XXXXXXXX")];
2671                 salt[0] = '$';
2672                 salt[1] = '1';
2673                 salt[2] = '$';
2674                 crypt_make_salt(salt + 3, 4);
2675                 puts(pw_encrypt(pass, salt, /*cleanup:*/ 0));
2676                 return 0;
2677         }
2678 #endif
2679 #if ENABLE_FEATURE_HTTPD_SETUID
2680         if (opt & OPT_SETUID) {
2681                 xget_uidgid(&ugid, s_ugid);
2682         }
2683 #endif
2684
2685 #if !BB_MMU
2686         if (!(opt & OPT_FOREGROUND)) {
2687                 bb_daemonize_or_rexec(0, argv); /* don't change current directory */
2688         }
2689 #endif
2690
2691         xchdir(home_httpd);
2692         if (!(opt & OPT_INETD)) {
2693                 signal(SIGCHLD, SIG_IGN);
2694                 server_socket = openServer();
2695 #if ENABLE_FEATURE_HTTPD_SETUID
2696                 /* drop privileges */
2697                 if (opt & OPT_SETUID) {
2698                         if (ugid.gid != (gid_t)-1) {
2699                                 if (setgroups(1, &ugid.gid) == -1)
2700                                         bb_perror_msg_and_die("setgroups");
2701                                 xsetgid(ugid.gid);
2702                         }
2703                         xsetuid(ugid.uid);
2704                 }
2705 #endif
2706         }
2707
2708 #if 0
2709         /* User can do it himself: 'env - PATH="$PATH" httpd'
2710          * We don't do it because we don't want to screw users
2711          * which want to do
2712          * 'env - VAR1=val1 VAR2=val2 httpd'
2713          * and have VAR1 and VAR2 values visible in their CGIs.
2714          * Besides, it is also smaller. */
2715         {
2716                 char *p = getenv("PATH");
2717                 /* env strings themself are not freed, no need to xstrdup(p): */
2718                 clearenv();
2719                 if (p)
2720                         putenv(p - 5);
2721 //              if (!(opt & OPT_INETD))
2722 //                      setenv_long("SERVER_PORT", ???);
2723         }
2724 #endif
2725
2726         parse_conf(DEFAULT_PATH_HTTPD_CONF, FIRST_PARSE);
2727         if (!(opt & OPT_INETD))
2728                 signal(SIGHUP, sighup_handler);
2729
2730         xfunc_error_retval = 0;
2731         if (opt & OPT_INETD)
2732                 mini_httpd_inetd();
2733 #if BB_MMU
2734         if (!(opt & OPT_FOREGROUND))
2735                 bb_daemonize(0); /* don't change current directory */
2736         mini_httpd(server_socket); /* never returns */
2737 #else
2738         mini_httpd_nommu(server_socket, argc, argv); /* never returns */
2739 #endif
2740         /* return 0; */
2741 }