networking/httpd.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * httpd implementation for busybox
   4  *
   5  * Copyright (C) 2002,2003 Glenn Engel <glenne@engel.org>
   6  * Copyright (C) 2003-2006 Vladimir Oleynik <dzo@simtreas.ru>
   7  *
   8  * Licensed under GPLv2 or later, see file LICENSE in this source tree.
   9  *
  10  *****************************************************************************
  11  *
  12  * Typical usage:
  13  * For non root user:
  14  *      httpd -p 8080 -h $HOME/public_html
  15  * For daemon start from rc script with uid=0:
  16  *      httpd -u www
  17  * which is equivalent to (assuming user www has uid 80):
  18  *      httpd -p 80 -u 80 -h $PWD -c /etc/httpd.conf -r "Web Server Authentication"
  19  *
  20  * When an url starts with "/cgi-bin/" it is assumed to be a cgi script.
  21  * The server changes directory to the location of the script and executes it
  22  * after setting QUERY_STRING and other environment variables.
  23  *
  24  * If directory URL is given, no index.html is found and CGI support is enabled,
  25  * cgi-bin/index.cgi will be run. Directory to list is ../$QUERY_STRING.
  26  * See httpd_indexcgi.c for an example GCI code.
  27  *
  28  * Doc:
  29  * "CGI Environment Variables": http://hoohoo.ncsa.uiuc.edu/cgi/env.html
  30  *
  31  * The applet can also be invoked as an url arg decoder and html text encoder
  32  * as follows:
  33  *      foo=`httpd -d $foo`             # decode "Hello%20World" as "Hello World"
  34  *      bar=`httpd -e "<Hello World>"`  # encode as "&#60Hello&#32World&#62"
  35  * Note that url encoding for arguments is not the same as html encoding for
  36  * presentation.  -d decodes an url-encoded argument while -e encodes in html
  37  * for page display.
  38  *
  39  * httpd.conf has the following format:
  40  *
  41  * H:/serverroot     # define the server root. It will override -h
  42  * A:172.20.         # Allow address from 172.20.0.0/16
  43  * A:10.0.0.0/25     # Allow any address from 10.0.0.0-10.0.0.127
  44  * A:10.0.0.0/255.255.255.128  # Allow any address that previous set
  45  * A:127.0.0.1       # Allow local loopback connections
  46  * D:*               # Deny from other IP connections
  47  * E404:/path/e404.html # /path/e404.html is the 404 (not found) error page
  48  * I:index.html      # Show index.html when a directory is requested
  49  *
  50  * P:/url:[http://]hostname[:port]/new/path
  51  *                   # When /urlXXXXXX is requested, reverse proxy
  52  *                   # it to http://hostname[:port]/new/pathXXXXXX
  53  *
  54  * /cgi-bin:foo:bar  # Require user foo, pwd bar on urls starting with /cgi-bin/
  55  * /adm:admin:setup  # Require user admin, pwd setup on urls starting with /adm/
  56  * /adm:toor:PaSsWd  # or user toor, pwd PaSsWd on urls starting with /adm/
  57  * /adm:root:*       # or user root, pwd from /etc/passwd on urls starting with /adm/
  58  * /wiki:*:*         # or any user from /etc/passwd with according pwd on urls starting with /wiki/
  59  * .au:audio/basic   # additional mime type for audio.au files
  60  * *.php:/path/php   # run xxx.php through an interpreter
  61  *
  62  * A/D may be as a/d or allow/deny - only first char matters.
  63  * Deny/Allow IP logic:
  64  *  - Default is to allow all (Allow all (A:*) is a no-op).
  65  *  - Deny rules take precedence over allow rules.
  66  *  - "Deny all" rule (D:*) is applied last.
  67  *
  68  * Example:
  69  *   1. Allow only specified addresses
  70  *     A:172.20          # Allow any address that begins with 172.20.
  71  *     A:10.10.          # Allow any address that begins with 10.10.
  72  *     A:127.0.0.1       # Allow local loopback connections
  73  *     D:*               # Deny from other IP connections
  74  *
  75  *   2. Only deny specified addresses
  76  *     D:1.2.3.        # deny from 1.2.3.0 - 1.2.3.255
  77  *     D:2.3.4.        # deny from 2.3.4.0 - 2.3.4.255
  78  *     A:*             # (optional line added for clarity)
  79  *
  80  * If a sub directory contains config file, it is parsed and merged with
  81  * any existing settings as if it was appended to the original configuration.
  82  *
  83  * subdir paths are relative to the containing subdir and thus cannot
  84  * affect the parent rules.
  85  *
  86  * Note that since the sub dir is parsed in the forked thread servicing the
  87  * subdir http request, any merge is discarded when the process exits.  As a
  88  * result, the subdir settings only have a lifetime of a single request.
  89  *
  90  * Custom error pages can contain an absolute path or be relative to
  91  * 'home_httpd'. Error pages are to be static files (no CGI or script). Error
  92  * page can only be defined in the root configuration file and are not taken
  93  * into account in local (directories) config files.
  94  *
  95  * If -c is not set, an attempt will be made to open the default
  96  * root configuration file.  If -c is set and the file is not found, the
  97  * server exits with an error.
  98  */
  99 //config:config HTTPD
 100 //config:       bool "httpd (32 kb)"
 101 //config:       default y
 102 //config:       help
 103 //config:       HTTP server.
 104 //config:
 105 //config:config FEATURE_HTTPD_RANGES
 106 //config:       bool "Support 'Ranges:' header"
 107 //config:       default y
 108 //config:       depends on HTTPD
 109 //config:       help
 110 //config:       Makes httpd emit "Accept-Ranges: bytes" header and understand
 111 //config:       "Range: bytes=NNN-[MMM]" header. Allows for resuming interrupted
 112 //config:       downloads, seeking in multimedia players etc.
 113 //config:
 114 //config:config FEATURE_HTTPD_SETUID
 115 //config:       bool "Enable -u <user> option"
 116 //config:       default y
 117 //config:       depends on HTTPD
 118 //config:       help
 119 //config:       This option allows the server to run as a specific user
 120 //config:       rather than defaulting to the user that starts the server.
 121 //config:       Use of this option requires special privileges to change to a
 122 //config:       different user.
 123 //config:
 124 //config:config FEATURE_HTTPD_BASIC_AUTH
 125 //config:       bool "Enable HTTP authentication"
 126 //config:       default y
 127 //config:       depends on HTTPD
 128 //config:       help
 129 //config:       Utilizes password settings from /etc/httpd.conf for basic
 130 //config:       authentication on a per url basis.
 131 //config:       Example for httpd.conf file:
 132 //config:       /adm:toor:PaSsWd
 133 //config:
 134 //config:config FEATURE_HTTPD_AUTH_MD5
 135 //config:       bool "Support MD5-encrypted passwords in HTTP authentication"
 136 //config:       default y
 137 //config:       depends on FEATURE_HTTPD_BASIC_AUTH
 138 //config:       help
 139 //config:       Enables encrypted passwords, and wildcard user/passwords
 140 //config:       in httpd.conf file.
 141 //config:       User '*' means 'any system user name is ok',
 142 //config:       password of '*' means 'use system password for this user'
 143 //config:       Examples:
 144 //config:       /adm:toor:$1$P/eKnWXS$aI1aPGxT.dJD5SzqAKWrF0
 145 //config:       /adm:root:*
 146 //config:       /wiki:*:*
 147 //config:
 148 //config:config FEATURE_HTTPD_CGI
 149 //config:       bool "Support Common Gateway Interface (CGI)"
 150 //config:       default y
 151 //config:       depends on HTTPD
 152 //config:       help
 153 //config:       This option allows scripts and executables to be invoked
 154 //config:       when specific URLs are requested.
 155 //config:
 156 //config:config FEATURE_HTTPD_CONFIG_WITH_SCRIPT_INTERPR
 157 //config:       bool "Support running scripts through an interpreter"
 158 //config:       default y
 159 //config:       depends on FEATURE_HTTPD_CGI
 160 //config:       help
 161 //config:       This option enables support for running scripts through an
 162 //config:       interpreter. Turn this on if you want PHP scripts to work
 163 //config:       properly. You need to supply an additional line in your
 164 //config:       httpd.conf file:
 165 //config:       *.php:/path/to/your/php
 166 //config:
 167 //config:config FEATURE_HTTPD_SET_REMOTE_PORT_TO_ENV
 168 //config:       bool "Set REMOTE_PORT environment variable for CGI"
 169 //config:       default y
 170 //config:       depends on FEATURE_HTTPD_CGI
 171 //config:       help
 172 //config:       Use of this option can assist scripts in generating
 173 //config:       references that contain a unique port number.
 174 //config:
 175 //config:config FEATURE_HTTPD_ENCODE_URL_STR
 176 //config:       bool "Enable -e option (useful for CGIs written as shell scripts)"
 177 //config:       default y
 178 //config:       depends on HTTPD
 179 //config:       help
 180 //config:       This option allows html encoding of arbitrary strings for display
 181 //config:       by the browser. Output goes to stdout.
 182 //config:       For example, httpd -e "<Hello World>" produces
 183 //config:       "&#60Hello&#32World&#62".
 184 //config:
 185 //config:config FEATURE_HTTPD_ERROR_PAGES
 186 //config:       bool "Support custom error pages"
 187 //config:       default y
 188 //config:       depends on HTTPD
 189 //config:       help
 190 //config:       This option allows you to define custom error pages in
 191 //config:       the configuration file instead of the default HTTP status
 192 //config:       error pages. For instance, if you add the line:
 193 //config:               E404:/path/e404.html
 194 //config:       in the config file, the server will respond the specified
 195 //config:       '/path/e404.html' file instead of the terse '404 NOT FOUND'
 196 //config:       message.
 197 //config:
 198 //config:config FEATURE_HTTPD_PROXY
 199 //config:       bool "Support reverse proxy"
 200 //config:       default y
 201 //config:       depends on HTTPD
 202 //config:       help
 203 //config:       This option allows you to define URLs that will be forwarded
 204 //config:       to another HTTP server. To setup add the following line to the
 205 //config:       configuration file
 206 //config:               P:/url/:http://hostname[:port]/new/path/
 207 //config:       Then a request to /url/myfile will be forwarded to
 208 //config:       http://hostname[:port]/new/path/myfile.
 209 //config:
 210 //config:config FEATURE_HTTPD_GZIP
 211 //config:       bool "Support GZIP content encoding"
 212 //config:       default y
 213 //config:       depends on HTTPD
 214 //config:       help
 215 //config:       Makes httpd send files using GZIP content encoding if the
 216 //config:       client supports it and a pre-compressed <file>.gz exists.
 217
 218 //applet:IF_HTTPD(APPLET(httpd, BB_DIR_USR_SBIN, BB_SUID_DROP))
 219
 220 //kbuild:lib-$(CONFIG_HTTPD) += httpd.o
 221
 222 //usage:#define httpd_trivial_usage
 223 //usage:       "[-ifv[v]]"
 224 //usage:       " [-c CONFFILE]"
 225 //usage:       " [-p [IP:]PORT]"
 226 //usage:        IF_FEATURE_HTTPD_SETUID(" [-u USER[:GRP]]")
 227 //usage:        IF_FEATURE_HTTPD_BASIC_AUTH(" [-r REALM]")
 228 //usage:       " [-h HOME]\n"
 229 //usage:       "or httpd -d/-e" IF_FEATURE_HTTPD_AUTH_MD5("/-m") " STRING"
 230 //usage:#define httpd_full_usage "\n\n"
 231 //usage:       "Listen for incoming HTTP requests\n"
 232 //usage:     "\n        -i              Inetd mode"
 233 //usage:     "\n        -f              Don't daemonize"
 234 //usage:     "\n        -v[v]           Verbose"
 235 //usage:     "\n        -p [IP:]PORT    Bind to IP:PORT (default *:80)"
 236 //usage:        IF_FEATURE_HTTPD_SETUID(
 237 //usage:     "\n        -u USER[:GRP]   Set uid/gid after binding to port")
 238 //usage:        IF_FEATURE_HTTPD_BASIC_AUTH(
 239 //usage:     "\n        -r REALM        Authentication Realm for Basic Authentication")
 240 //usage:     "\n        -h HOME         Home directory (default .)"
 241 //usage:     "\n        -c FILE         Configuration file (default {/etc,HOME}/httpd.conf)"
 242 //usage:        IF_FEATURE_HTTPD_AUTH_MD5(
 243 //usage:     "\n        -m STRING       MD5 crypt STRING")
 244 //usage:     "\n        -e STRING       HTML encode STRING"
 245 //usage:     "\n        -d STRING       URL decode STRING"
 246
 247 /* TODO: use TCP_CORK, parse_config() */
 248
 249 #include "libbb.h"
 250 #include "common_bufsiz.h"
 251 #if ENABLE_PAM
 252 /* PAM may include <locale.h>. We may need to undefine bbox's stub define: */
 253 # undef setlocale
 254 /* For some obscure reason, PAM is not in pam/xxx, but in security/xxx.
 255  * Apparently they like to confuse people. */
 256 # include <security/pam_appl.h>
 257 # include <security/pam_misc.h>
 258 #endif
 259 #if ENABLE_FEATURE_USE_SENDFILE
 260 # include <sys/sendfile.h>
 261 #endif
 262
 263 #define DEBUG 0
 264
 265 #define IOBUF_SIZE 8192
 266 #define MAX_HTTP_HEADERS_SIZE (32*1024)
 267
 268 #define HEADER_READ_TIMEOUT 60
 269
 270 static const char DEFAULT_PATH_HTTPD_CONF[] ALIGN1 = "/etc";
 271 static const char HTTPD_CONF[] ALIGN1 = "httpd.conf";
 272 static const char HTTP_200[] ALIGN1 = "HTTP/1.0 200 OK\r\n";
 273 static const char index_html[] ALIGN1 = "index.html";
 274
 275 typedef struct has_next_ptr {
 276         struct has_next_ptr *next;
 277 } has_next_ptr;
 278
 279 /* Must have "next" as a first member */
 280 typedef struct Htaccess {
 281         struct Htaccess *next;
 282         char *after_colon;
 283         char before_colon[1];  /* really bigger, must be last */
 284 } Htaccess;
 285
 286 /* Must have "next" as a first member */
 287 typedef struct Htaccess_IP {
 288         struct Htaccess_IP *next;
 289         unsigned ip;
 290         unsigned mask;
 291         int allow_deny;
 292 } Htaccess_IP;
 293
 294 /* Must have "next" as a first member */
 295 typedef struct Htaccess_Proxy {
 296         struct Htaccess_Proxy *next;
 297         char *url_from;
 298         char *host_port;
 299         char *url_to;
 300 } Htaccess_Proxy;
 301
 302 typedef enum CGI_type {
 303         CGI_NONE = 0,
 304         CGI_NORMAL,
 305         CGI_INDEX,
 306         CGI_INTERPRETER,
 307 } CGI_type;
 308
 309 enum {
 310         HTTP_OK = 200,
 311         HTTP_PARTIAL_CONTENT = 206,
 312         HTTP_MOVED_TEMPORARILY = 302,
 313         HTTP_BAD_REQUEST = 400,       /* malformed syntax */
 314         HTTP_UNAUTHORIZED = 401, /* authentication needed, respond with auth hdr */
 315         HTTP_NOT_FOUND = 404,
 316         HTTP_FORBIDDEN = 403,
 317         HTTP_REQUEST_TIMEOUT = 408,
 318         HTTP_NOT_IMPLEMENTED = 501,   /* used for unrecognized requests */
 319         HTTP_INTERNAL_SERVER_ERROR = 500,
 320         HTTP_ENTITY_TOO_LARGE = 413,
 321         HTTP_CONTINUE = 100,
 322 #if 0   /* future use */
 323         HTTP_SWITCHING_PROTOCOLS = 101,
 324         HTTP_CREATED = 201,
 325         HTTP_ACCEPTED = 202,
 326         HTTP_NON_AUTHORITATIVE_INFO = 203,
 327         HTTP_NO_CONTENT = 204,
 328         HTTP_MULTIPLE_CHOICES = 300,
 329         HTTP_MOVED_PERMANENTLY = 301,
 330         HTTP_NOT_MODIFIED = 304,
 331         HTTP_PAYMENT_REQUIRED = 402,
 332         HTTP_BAD_GATEWAY = 502,
 333         HTTP_SERVICE_UNAVAILABLE = 503, /* overload, maintenance */
 334 #endif
 335 };
 336
 337 static const uint16_t http_response_type[] ALIGN2 = {
 338         HTTP_OK,
 339 #if ENABLE_FEATURE_HTTPD_RANGES
 340         HTTP_PARTIAL_CONTENT,
 341 #endif
 342         HTTP_MOVED_TEMPORARILY,
 343         HTTP_REQUEST_TIMEOUT,
 344         HTTP_NOT_IMPLEMENTED,
 345 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
 346         HTTP_UNAUTHORIZED,
 347 #endif
 348         HTTP_NOT_FOUND,
 349         HTTP_BAD_REQUEST,
 350         HTTP_FORBIDDEN,
 351         HTTP_INTERNAL_SERVER_ERROR,
 352         HTTP_ENTITY_TOO_LARGE,
 353 #if 0   /* not implemented */
 354         HTTP_CREATED,
 355         HTTP_ACCEPTED,
 356         HTTP_NO_CONTENT,
 357         HTTP_MULTIPLE_CHOICES,
 358         HTTP_MOVED_PERMANENTLY,
 359         HTTP_NOT_MODIFIED,
 360         HTTP_BAD_GATEWAY,
 361         HTTP_SERVICE_UNAVAILABLE,
 362 #endif
 363 };
 364
 365 static const struct {
 366         const char *name;
 367         const char *info;
 368 } http_response[ARRAY_SIZE(http_response_type)] = {
 369         { "OK", NULL },
 370 #if ENABLE_FEATURE_HTTPD_RANGES
 371         { "Partial Content", NULL },
 372 #endif
 373         { "Found", NULL },
 374         { "Request Timeout", "No request appeared within 60 seconds" },
 375         { "Not Implemented", "The requested method is not recognized" },
 376 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
 377         { "Unauthorized", "" },
 378 #endif
 379         { "Not Found", "The requested URL was not found" },
 380         { "Bad Request", "Unsupported method" },
 381         { "Forbidden", ""  },
 382         { "Internal Server Error", "Internal Server Error" },
 383         { "Entity Too Large", "Entity Too Large" },
 384 #if 0   /* not implemented */
 385         { "Created" },
 386         { "Accepted" },
 387         { "No Content" },
 388         { "Multiple Choices" },
 389         { "Moved Permanently" },
 390         { "Not Modified" },
 391         { "Bad Gateway", "" },
 392         { "Service Unavailable", "" },
 393 #endif
 394 };
 395
 396 struct globals {
 397         int verbose;            /* must be int (used by getopt32) */
 398         smallint flg_deny_all;
 399 #if ENABLE_FEATURE_HTTPD_GZIP
 400         /* client can handle gzip / we are going to send gzip */
 401         smallint content_gzip;
 402 #endif
 403         time_t last_mod;
 404         char *rmt_ip_str;       /* for $REMOTE_ADDR and $REMOTE_PORT */
 405         const char *bind_addr_or_port;
 406
 407         char *g_query;
 408         const char *opt_c_configFile;
 409         const char *home_httpd;
 410         const char *index_page;
 411
 412         const char *found_mime_type;
 413         const char *found_moved_temporarily;
 414         Htaccess_IP *ip_a_d;    /* config allow/deny lines */
 415
 416         IF_FEATURE_HTTPD_BASIC_AUTH(const char *g_realm;)
 417         IF_FEATURE_HTTPD_BASIC_AUTH(char *remoteuser;)
 418
 419         off_t file_size;        /* -1 - unknown */
 420 #if ENABLE_FEATURE_HTTPD_RANGES
 421         off_t range_start;
 422         off_t range_end;
 423         off_t range_len;
 424 #endif
 425
 426 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
 427         Htaccess *g_auth;       /* config user:password lines */
 428 #endif
 429         Htaccess *mime_a;       /* config mime types */
 430 #if ENABLE_FEATURE_HTTPD_CONFIG_WITH_SCRIPT_INTERPR
 431         Htaccess *script_i;     /* config script interpreters */
 432 #endif
 433         char *iobuf;            /* [IOBUF_SIZE] */
 434 #define        hdr_buf bb_common_bufsiz1
 435 #define sizeof_hdr_buf COMMON_BUFSIZE
 436         char *hdr_ptr;
 437         int hdr_cnt;
 438 #if ENABLE_FEATURE_HTTPD_ERROR_PAGES
 439         const char *http_error_page[ARRAY_SIZE(http_response_type)];
 440 #endif
 441 #if ENABLE_FEATURE_HTTPD_PROXY
 442         Htaccess_Proxy *proxy;
 443 #endif
 444 };
 445 #define G (*ptr_to_globals)
 446 #define verbose           (G.verbose          )
 447 #define flg_deny_all      (G.flg_deny_all     )
 448 #if ENABLE_FEATURE_HTTPD_GZIP
 449 # define content_gzip     (G.content_gzip     )
 450 #else
 451 # define content_gzip     0
 452 #endif
 453 #define bind_addr_or_port (G.bind_addr_or_port)
 454 #define g_query           (G.g_query          )
 455 #define opt_c_configFile  (G.opt_c_configFile )
 456 #define home_httpd        (G.home_httpd       )
 457 #define index_page        (G.index_page       )
 458 #define found_mime_type   (G.found_mime_type  )
 459 #define found_moved_temporarily (G.found_moved_temporarily)
 460 #define last_mod          (G.last_mod         )
 461 #define ip_a_d            (G.ip_a_d           )
 462 #define g_realm           (G.g_realm          )
 463 #define remoteuser        (G.remoteuser       )
 464 #define file_size         (G.file_size        )
 465 #if ENABLE_FEATURE_HTTPD_RANGES
 466 #define range_start       (G.range_start      )
 467 #define range_end         (G.range_end        )
 468 #define range_len         (G.range_len        )
 469 #else
 470 enum {
 471         range_start = -1,
 472         range_end = MAXINT(off_t) - 1,
 473         range_len = MAXINT(off_t),
 474 };
 475 #endif
 476 #define rmt_ip_str        (G.rmt_ip_str       )
 477 #define g_auth            (G.g_auth           )
 478 #define mime_a            (G.mime_a           )
 479 #define script_i          (G.script_i         )
 480 #define iobuf             (G.iobuf            )
 481 #define hdr_ptr           (G.hdr_ptr          )
 482 #define hdr_cnt           (G.hdr_cnt          )
 483 #define http_error_page   (G.http_error_page  )
 484 #define proxy             (G.proxy            )
 485 #define INIT_G() do { \
 486         setup_common_bufsiz(); \
 487         SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
 488         IF_FEATURE_HTTPD_BASIC_AUTH(g_realm = "Web Server Authentication";) \
 489         IF_FEATURE_HTTPD_RANGES(range_start = -1;) \
 490         bind_addr_or_port = "80"; \
 491         index_page = index_html; \
 492         file_size = -1; \
 493 } while (0)
 494
 495
 496 #define STRNCASECMP(a, str) strncasecmp((a), (str), sizeof(str)-1)
 497
 498 /* Prototypes */
 499 enum {
 500         SEND_HEADERS     = (1 << 0),
 501         SEND_BODY        = (1 << 1),
 502         SEND_HEADERS_AND_BODY = SEND_HEADERS + SEND_BODY,
 503 };
 504 static void send_file_and_exit(const char *url, int what) NORETURN;
 505
 506 static void free_llist(has_next_ptr **pptr)
 507 {
 508         has_next_ptr *cur = *pptr;
 509         while (cur) {
 510                 has_next_ptr *t = cur;
 511                 cur = cur->next;
 512                 free(t);
 513         }
 514         *pptr = NULL;
 515 }
 516
 517 static ALWAYS_INLINE void free_Htaccess_list(Htaccess **pptr)
 518 {
 519         free_llist((has_next_ptr**)pptr);
 520 }
 521
 522 static ALWAYS_INLINE void free_Htaccess_IP_list(Htaccess_IP **pptr)
 523 {
 524         free_llist((has_next_ptr**)pptr);
 525 }
 526
 527 /* Returns presumed mask width in bits or < 0 on error.
 528  * Updates strp, stores IP at provided pointer */
 529 static int scan_ip(const char **strp, unsigned *ipp, unsigned char endc)
 530 {
 531         const char *p = *strp;
 532         int auto_mask = 8;
 533         unsigned ip = 0;
 534         int j;
 535
 536         if (*p == '/')
 537                 return -auto_mask;
 538
 539         for (j = 0; j < 4; j++) {
 540                 unsigned octet;
 541
 542                 if ((*p < '0' || *p > '9') && *p != '/' && *p)
 543                         return -auto_mask;
 544                 octet = 0;
 545                 while (*p >= '0' && *p <= '9') {
 546                         octet *= 10;
 547                         octet += *p - '0';
 548                         if (octet > 255)
 549                                 return -auto_mask;
 550                         p++;
 551                 }
 552                 if (*p == '.')
 553                         p++;
 554                 if (*p != '/' && *p)
 555                         auto_mask += 8;
 556                 ip = (ip << 8) | octet;
 557         }
 558         if (*p) {
 559                 if (*p != endc)
 560                         return -auto_mask;
 561                 p++;
 562                 if (*p == '\0')
 563                         return -auto_mask;
 564         }
 565         *ipp = ip;
 566         *strp = p;
 567         return auto_mask;
 568 }
 569
 570 /* Returns 0 on success. Stores IP and mask at provided pointers */
 571 static int scan_ip_mask(const char *str, unsigned *ipp, unsigned *maskp)
 572 {
 573         int i;
 574         unsigned mask;
 575         char *p;
 576
 577         i = scan_ip(&str, ipp, '/');
 578         if (i < 0)
 579                 return i;
 580
 581         if (*str) {
 582                 /* there is /xxx after dotted-IP address */
 583                 i = bb_strtou(str, &p, 10);
 584                 if (*p == '.') {
 585                         /* 'xxx' itself is dotted-IP mask, parse it */
 586                         /* (return 0 (success) only if it has N.N.N.N form) */
 587                         return scan_ip(&str, maskp, '\0') - 32;
 588                 }
 589                 if (*p)
 590                         return -1;
 591         }
 592
 593         if (i > 32)
 594                 return -1;
 595
 596         if (sizeof(unsigned) == 4 && i == 32) {
 597                 /* mask >>= 32 below may not work */
 598                 mask = 0;
 599         } else {
 600                 mask = 0xffffffff;
 601                 mask >>= i;
 602         }
 603         /* i == 0 -> *maskp = 0x00000000
 604          * i == 1 -> *maskp = 0x80000000
 605          * i == 4 -> *maskp = 0xf0000000
 606          * i == 31 -> *maskp = 0xfffffffe
 607          * i == 32 -> *maskp = 0xffffffff */
 608         *maskp = (uint32_t)(~mask);
 609         return 0;
 610 }
 611
 612 /*
 613  * Parse configuration file into in-memory linked list.
 614  *
 615  * Any previous IP rules are discarded.
 616  * If the flag argument is not SUBDIR_PARSE then all /path and mime rules
 617  * are also discarded.  That is, previous settings are retained if flag is
 618  * SUBDIR_PARSE.
 619  * Error pages are only parsed on the main config file.
 620  *
 621  * path   Path where to look for httpd.conf (without filename).
 622  * flag   Type of the parse request.
 623  */
 624 /* flag param: */
 625 enum {
 626         FIRST_PARSE    = 0, /* path will be "/etc" */
 627         SIGNALED_PARSE = 1, /* path will be "/etc" */
 628         SUBDIR_PARSE   = 2, /* path will be derived from URL */
 629 };
 630 static void parse_conf(const char *path, int flag)
 631 {
 632         /* internally used extra flag state */
 633         enum { TRY_CURDIR_PARSE = 3 };
 634
 635         FILE *f;
 636         const char *filename;
 637         char buf[160];
 638
 639         /* discard old rules */
 640         free_Htaccess_IP_list(&ip_a_d);
 641         flg_deny_all = 0;
 642         /* retain previous auth and mime config only for subdir parse */
 643         if (flag != SUBDIR_PARSE) {
 644                 free_Htaccess_list(&mime_a);
 645 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
 646                 free_Htaccess_list(&g_auth);
 647 #endif
 648 #if ENABLE_FEATURE_HTTPD_CONFIG_WITH_SCRIPT_INTERPR
 649                 free_Htaccess_list(&script_i);
 650 #endif
 651         }
 652
 653         filename = opt_c_configFile;
 654         if (flag == SUBDIR_PARSE || filename == NULL) {
 655                 filename = alloca(strlen(path) + sizeof(HTTPD_CONF) + 2);
 656                 sprintf((char *)filename, "%s/%s", path, HTTPD_CONF);
 657         }
 658
 659         while ((f = fopen_for_read(filename)) == NULL) {
 660                 if (flag >= SUBDIR_PARSE) { /* SUBDIR or TRY_CURDIR */
 661                         /* config file not found, no changes to config */
 662                         return;
 663                 }
 664                 if (flag == FIRST_PARSE) {
 665                         /* -c CONFFILE given, but CONFFILE doesn't exist? */
 666                         if (opt_c_configFile)
 667                                 bb_simple_perror_msg_and_die(opt_c_configFile);
 668                         /* else: no -c, thus we looked at /etc/httpd.conf,
 669                          * and it's not there. try ./httpd.conf: */
 670                 }
 671                 flag = TRY_CURDIR_PARSE;
 672                 filename = HTTPD_CONF;
 673         }
 674
 675 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
 676         /* in "/file:user:pass" lines, we prepend path in subdirs */
 677         if (flag != SUBDIR_PARSE)
 678                 path = "";
 679 #endif
 680         /* The lines can be:
 681          *
 682          * I:default_index_file
 683          * H:http_home
 684          * [AD]:IP[/mask]   # allow/deny, * for wildcard
 685          * Ennn:error.html  # error page for status nnn
 686          * P:/url:[http://]hostname[:port]/new/path # reverse proxy
 687          * .ext:mime/type   # mime type
 688          * *.php:/path/php  # run xxx.php through an interpreter
 689          * /file:user:pass  # username and password
 690          */
 691         while (fgets(buf, sizeof(buf), f) != NULL) {
 692                 unsigned strlen_buf;
 693                 unsigned char ch;
 694                 char *after_colon;
 695
 696                 { /* remove all whitespace, and # comments */
 697                         char *p, *p0;
 698
 699                         p0 = buf;
 700                         /* skip non-whitespace beginning. Often the whole line
 701                          * is non-whitespace. We want this case to work fast,
 702                          * without needless copying, therefore we don't merge
 703                          * this operation into next while loop. */
 704                         while ((ch = *p0) != '\0' && ch != '\n' && ch != '#'
 705                          && ch != ' ' && ch != '\t'
 706                         ) {
 707                                 p0++;
 708                         }
 709                         p = p0;
 710                         /* if we enter this loop, we have some whitespace.
 711                          * discard it */
 712                         while (ch != '\0' && ch != '\n' && ch != '#') {
 713                                 if (ch != ' ' && ch != '\t') {
 714                                         *p++ = ch;
 715                                 }
 716                                 ch = *++p0;
 717                         }
 718                         *p = '\0';
 719                         strlen_buf = p - buf;
 720                         if (strlen_buf == 0)
 721                                 continue; /* empty line */
 722                 }
 723
 724                 after_colon = strchr(buf, ':');
 725                 /* strange line? */
 726                 if (after_colon == NULL || *++after_colon == '\0')
 727                         goto config_error;
 728
 729                 ch = (buf[0] & ~0x20); /* toupper if it's a letter */
 730
 731                 if (ch == 'I') {
 732                         if (index_page != index_html)
 733                                 free((char*)index_page);
 734                         index_page = xstrdup(after_colon);
 735                         continue;
 736                 }
 737
 738                 /* do not allow jumping around using H in subdir's configs */
 739                 if (flag == FIRST_PARSE && ch == 'H') {
 740                         home_httpd = xstrdup(after_colon);
 741                         xchdir(home_httpd);
 742                         continue;
 743                 }
 744
 745                 if (ch == 'A' || ch == 'D') {
 746                         Htaccess_IP *pip;
 747
 748                         if (*after_colon == '*') {
 749                                 if (ch == 'D') {
 750                                         /* memorize "deny all" */
 751                                         flg_deny_all = 1;
 752                                 }
 753                                 /* skip assumed "A:*", it is a default anyway */
 754                                 continue;
 755                         }
 756                         /* store "allow/deny IP/mask" line */
 757                         pip = xzalloc(sizeof(*pip));
 758                         if (scan_ip_mask(after_colon, &pip->ip, &pip->mask)) {
 759                                 /* IP{/mask} syntax error detected, protect all */
 760                                 ch = 'D';
 761                                 pip->mask = 0;
 762                         }
 763                         pip->allow_deny = ch;
 764                         if (ch == 'D') {
 765                                 /* Deny:from_IP - prepend */
 766                                 pip->next = ip_a_d;
 767                                 ip_a_d = pip;
 768                         } else {
 769                                 /* A:from_IP - append (thus all D's precedes A's) */
 770                                 Htaccess_IP *prev_IP = ip_a_d;
 771                                 if (prev_IP == NULL) {
 772                                         ip_a_d = pip;
 773                                 } else {
 774                                         while (prev_IP->next)
 775                                                 prev_IP = prev_IP->next;
 776                                         prev_IP->next = pip;
 777                                 }
 778                         }
 779                         continue;
 780                 }
 781
 782 #if ENABLE_FEATURE_HTTPD_ERROR_PAGES
 783                 if (flag == FIRST_PARSE && ch == 'E') {
 784                         unsigned i;
 785                         int status = atoi(buf + 1); /* error status code */
 786
 787                         if (status < HTTP_CONTINUE) {
 788                                 goto config_error;
 789                         }
 790                         /* then error page; find matching status */
 791                         for (i = 0; i < ARRAY_SIZE(http_response_type); i++) {
 792                                 if (http_response_type[i] == status) {
 793                                         /* We chdir to home_httpd, thus no need to
 794                                          * concat_path_file(home_httpd, after_colon)
 795                                          * here */
 796                                         http_error_page[i] = xstrdup(after_colon);
 797                                         break;
 798                                 }
 799                         }
 800                         continue;
 801                 }
 802 #endif
 803
 804 #if ENABLE_FEATURE_HTTPD_PROXY
 805                 if (flag == FIRST_PARSE && ch == 'P') {
 806                         /* P:/url:[http://]hostname[:port]/new/path */
 807                         char *url_from, *host_port, *url_to;
 808                         Htaccess_Proxy *proxy_entry;
 809
 810                         url_from = after_colon;
 811                         host_port = strchr(after_colon, ':');
 812                         if (host_port == NULL) {
 813                                 goto config_error;
 814                         }
 815                         *host_port++ = '\0';
 816                         if (is_prefixed_with(host_port, "http://"))
 817                                 host_port += 7;
 818                         if (*host_port == '\0') {
 819                                 goto config_error;
 820                         }
 821                         url_to = strchr(host_port, '/');
 822                         if (url_to == NULL) {
 823                                 goto config_error;
 824                         }
 825                         *url_to = '\0';
 826                         proxy_entry = xzalloc(sizeof(*proxy_entry));
 827                         proxy_entry->url_from = xstrdup(url_from);
 828                         proxy_entry->host_port = xstrdup(host_port);
 829                         *url_to = '/';
 830                         proxy_entry->url_to = xstrdup(url_to);
 831                         proxy_entry->next = proxy;
 832                         proxy = proxy_entry;
 833                         continue;
 834                 }
 835 #endif
 836                 /* the rest of directives are non-alphabetic,
 837                  * must avoid using "toupper'ed" ch */
 838                 ch = buf[0];
 839
 840                 if (ch == '.' /* ".ext:mime/type" */
 841 #if ENABLE_FEATURE_HTTPD_CONFIG_WITH_SCRIPT_INTERPR
 842                  || (ch == '*' && buf[1] == '.') /* "*.php:/path/php" */
 843 #endif
 844                 ) {
 845                         char *p;
 846                         Htaccess *cur;
 847
 848                         cur = xzalloc(sizeof(*cur) /* includes space for NUL */ + strlen_buf);
 849                         strcpy(cur->before_colon, buf);
 850                         p = cur->before_colon + (after_colon - buf);
 851                         p[-1] = '\0';
 852                         cur->after_colon = p;
 853                         if (ch == '.') {
 854                                 /* .mime line: prepend to mime_a list */
 855                                 cur->next = mime_a;
 856                                 mime_a = cur;
 857                         }
 858 #if ENABLE_FEATURE_HTTPD_CONFIG_WITH_SCRIPT_INTERPR
 859                         else {
 860                                 /* script interpreter line: prepend to script_i list */
 861                                 cur->next = script_i;
 862                                 script_i = cur;
 863                         }
 864 #endif
 865                         continue;
 866                 }
 867
 868 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
 869                 if (ch == '/') { /* "/file:user:pass" */
 870                         char *p;
 871                         Htaccess *cur;
 872                         unsigned file_len;
 873
 874                         /* note: path is "" unless we are in SUBDIR parse,
 875                          * otherwise it does NOT start with "/" */
 876                         cur = xzalloc(sizeof(*cur) /* includes space for NUL */
 877                                 + 1 + strlen(path)
 878                                 + strlen_buf
 879                                 );
 880                         /* form "/path/file" */
 881                         sprintf(cur->before_colon, "/%s%.*s",
 882                                 path,
 883                                 (int) (after_colon - buf - 1), /* includes "/", but not ":" */
 884                                 buf);
 885                         /* canonicalize it */
 886                         p = bb_simplify_abs_path_inplace(cur->before_colon);
 887                         file_len = p - cur->before_colon;
 888                         /* add "user:pass" after NUL */
 889                         strcpy(++p, after_colon);
 890                         cur->after_colon = p;
 891
 892                         /* insert cur into g_auth */
 893                         /* g_auth is sorted by decreased filename length */
 894                         {
 895                                 Htaccess *auth, **authp;
 896
 897                                 authp = &g_auth;
 898                                 while ((auth = *authp) != NULL) {
 899                                         if (file_len >= strlen(auth->before_colon)) {
 900                                                 /* insert cur before auth */
 901                                                 cur->next = auth;
 902                                                 break;
 903                                         }
 904                                         authp = &auth->next;
 905                                 }
 906                                 *authp = cur;
 907                         }
 908                         continue;
 909                 }
 910 #endif /* BASIC_AUTH */
 911
 912                 /* the line is not recognized */
 913  config_error:
 914                 bb_error_msg("config error '%s' in '%s'", buf, filename);
 915         } /* while (fgets) */
 916
 917         fclose(f);
 918 }
 919
 920 #if ENABLE_FEATURE_HTTPD_ENCODE_URL_STR
 921 /*
 922  * Given a string, html-encode special characters.
 923  * This is used for the -e command line option to provide an easy way
 924  * for scripts to encode result data without confusing browsers.  The
 925  * returned string pointer is memory allocated by malloc().
 926  *
 927  * Returns a pointer to the encoded string (malloced).
 928  */
 929 static char *encodeString(const char *string)
 930 {
 931         /* take the simple route and encode everything */
 932         /* could possibly scan once to get length.     */
 933         int len = strlen(string);
 934         char *out = xmalloc(len * 6 + 1);
 935         char *p = out;
 936         char ch;
 937
 938         while ((ch = *string++) != '\0') {
 939                 /* very simple check for what to encode */
 940                 if (isalnum(ch))
 941                         *p++ = ch;
 942                 else
 943                         p += sprintf(p, "&#%u;", (unsigned char) ch);
 944         }
 945         *p = '\0';
 946         return out;
 947 }
 948 #endif
 949
 950 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
 951 /*
 952  * Decode a base64 data stream as per rfc1521.
 953  * Note that the rfc states that non base64 chars are to be ignored.
 954  * Since the decode always results in a shorter size than the input,
 955  * it is OK to pass the input arg as an output arg.
 956  * Parameter: a pointer to a base64 encoded string.
 957  * Decoded data is stored in-place.
 958  */
 959 static void decodeBase64(char *Data)
 960 {
 961         const unsigned char *in = (const unsigned char *)Data;
 962         /* The decoded size will be at most 3/4 the size of the encoded */
 963         unsigned ch = 0;
 964         int i = 0;
 965
 966         while (*in) {
 967                 int t = *in++;
 968
 969                 if (t >= '0' && t <= '9')
 970                         t = t - '0' + 52;
 971                 else if (t >= 'A' && t <= 'Z')
 972                         t = t - 'A';
 973                 else if (t >= 'a' && t <= 'z')
 974                         t = t - 'a' + 26;
 975                 else if (t == '+')
 976                         t = 62;
 977                 else if (t == '/')
 978                         t = 63;
 979                 else if (t == '=')
 980                         t = 0;
 981                 else
 982                         continue;
 983
 984                 ch = (ch << 6) | t;
 985                 i++;
 986                 if (i == 4) {
 987                         *Data++ = (char) (ch >> 16);
 988                         *Data++ = (char) (ch >> 8);
 989                         *Data++ = (char) ch;
 990                         i = 0;
 991                 }
 992         }
 993         *Data = '\0';
 994 }
 995 #endif
 996
 997 /*
 998  * Create a listen server socket on the designated port.
 999  */
1000 static int openServer(void)
1001 {
1002         unsigned n = bb_strtou(bind_addr_or_port, NULL, 10);
1003         if (!errno && n && n <= 0xffff)
1004                 n = create_and_bind_stream_or_die(NULL, n);
1005         else
1006                 n = create_and_bind_stream_or_die(bind_addr_or_port, 80);
1007         xlisten(n, 9);
1008         return n;
1009 }
1010
1011 /*
1012  * Log the connection closure and exit.
1013  */
1014 static void log_and_exit(void) NORETURN;
1015 static void log_and_exit(void)
1016 {
1017         /* Paranoia. IE said to be buggy. It may send some extra data
1018          * or be confused by us just exiting without SHUT_WR. Oh well. */
1019         shutdown(1, SHUT_WR);
1020         /* Why??
1021         (this also messes up stdin when user runs httpd -i from terminal)
1022         ndelay_on(0);
1023         while (read(STDIN_FILENO, iobuf, IOBUF_SIZE) > 0)
1024                 continue;
1025         */
1026
1027         if (verbose > 2)
1028                 bb_simple_error_msg("closed");
1029         _exit(xfunc_error_retval);
1030 }
1031
1032 /*
1033  * Create and send HTTP response headers.
1034  * The arguments are combined and sent as one write operation.  Note that
1035  * IE will puke big-time if the headers are not sent in one packet and the
1036  * second packet is delayed for any reason.
1037  * responseNum - the result code to send.
1038  */
1039 static void send_headers(unsigned responseNum)
1040 {
1041         static const char RFC1123FMT[] ALIGN1 = "%a, %d %b %Y %H:%M:%S GMT";
1042         /* Fixed size 29-byte string. Example: Sun, 06 Nov 1994 08:49:37 GMT */
1043         char date_str[40]; /* using a bit larger buffer to paranoia reasons */
1044
1045         struct tm tm;
1046         const char *responseString = "";
1047         const char *infoString = NULL;
1048 #if ENABLE_FEATURE_HTTPD_ERROR_PAGES
1049         const char *error_page = NULL;
1050 #endif
1051         unsigned len;
1052         unsigned i;
1053         time_t timer = time(NULL);
1054
1055         for (i = 0; i < ARRAY_SIZE(http_response_type); i++) {
1056                 if (http_response_type[i] == responseNum) {
1057                         responseString = http_response[i].name;
1058                         infoString = http_response[i].info;
1059 #if ENABLE_FEATURE_HTTPD_ERROR_PAGES
1060                         error_page = http_error_page[i];
1061 #endif
1062                         break;
1063                 }
1064         }
1065
1066         if (verbose)
1067                 bb_error_msg("response:%u", responseNum);
1068
1069         /* We use sprintf, not snprintf (it's less code).
1070          * iobuf[] is several kbytes long and all headers we generate
1071          * always fit into those kbytes.
1072          */
1073
1074         strftime(date_str, sizeof(date_str), RFC1123FMT, gmtime_r(&timer, &tm));
1075         /* ^^^ using gmtime_r() instead of gmtime() to not use static data */
1076         len = sprintf(iobuf,
1077                         "HTTP/1.0 %u %s\r\n"
1078                         "Date: %s\r\n"
1079                         "Connection: close\r\n",
1080                         responseNum, responseString,
1081                         date_str
1082         );
1083
1084         if (responseNum != HTTP_OK || found_mime_type) {
1085                 len += sprintf(iobuf + len,
1086                                 "Content-type: %s\r\n",
1087                                 /* if it's error message, then it's HTML */
1088                                 (responseNum != HTTP_OK ? "text/html" : found_mime_type)
1089                 );
1090         }
1091
1092 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
1093         if (responseNum == HTTP_UNAUTHORIZED) {
1094                 len += sprintf(iobuf + len,
1095                                 "WWW-Authenticate: Basic realm=\"%.999s\"\r\n",
1096                                 g_realm /* %.999s protects from overflowing iobuf[] */
1097                 );
1098         }
1099 #endif
1100         if (responseNum == HTTP_MOVED_TEMPORARILY) {
1101                 /* Responding to "GET /dir" with
1102                  * "HTTP/1.0 302 Found" "Location: /dir/"
1103                  * - IOW, asking them to repeat with a slash.
1104                  * Here, overflow IS possible, can't use sprintf:
1105                  * mkdir test
1106                  * python -c 'print("get /test?" + ("x" * 8192))' | busybox httpd -i -h .
1107                  */
1108                 len += snprintf(iobuf + len, IOBUF_SIZE-3 - len,
1109                                 "Location: %s/%s%s\r\n",
1110                                 found_moved_temporarily,
1111                                 (g_query ? "?" : ""),
1112                                 (g_query ? g_query : "")
1113                 );
1114                 if (len > IOBUF_SIZE-3)
1115                         len = IOBUF_SIZE-3;
1116         }
1117
1118 #if ENABLE_FEATURE_HTTPD_ERROR_PAGES
1119         if (error_page && access(error_page, R_OK) == 0) {
1120                 iobuf[len++] = '\r';
1121                 iobuf[len++] = '\n';
1122                 if (DEBUG) {
1123                         iobuf[len] = '\0';
1124                         fprintf(stderr, "headers: '%s'\n", iobuf);
1125                 }
1126                 full_write(STDOUT_FILENO, iobuf, len);
1127                 if (DEBUG)
1128                         fprintf(stderr, "writing error page: '%s'\n", error_page);
1129                 return send_file_and_exit(error_page, SEND_BODY);
1130         }
1131 #endif
1132
1133         if (file_size != -1) {    /* file */
1134                 strftime(date_str, sizeof(date_str), RFC1123FMT, gmtime_r(&last_mod, &tm));
1135 #if ENABLE_FEATURE_HTTPD_RANGES
1136                 if (responseNum == HTTP_PARTIAL_CONTENT) {
1137                         len += sprintf(iobuf + len,
1138                                 "Content-Range: bytes %"OFF_FMT"u-%"OFF_FMT"u/%"OFF_FMT"u\r\n",
1139                                         range_start,
1140                                         range_end,
1141                                         file_size
1142                         );
1143                         file_size = range_end - range_start + 1;
1144                 }
1145 #endif
1146
1147 //RFC 2616 4.4 Message Length
1148 // The transfer-length of a message is the length of the message-body as
1149 // it appears in the message; that is, after any transfer-codings have
1150 // been applied. When a message-body is included with a message, the
1151 // transfer-length of that body is determined by one of the following
1152 // (in order of precedence):
1153 // 1.Any response message which "MUST NOT" include a message-body (such
1154 //   as the 1xx, 204, and 304 responses and any response to a HEAD
1155 //   request) is always terminated by the first empty line after the
1156 //   header fields, regardless of the entity-header fields present in
1157 //   the message.
1158 // 2.If a Transfer-Encoding header field (section 14.41) is present and
1159 //   has any value other than "identity", then the transfer-length is
1160 //   defined by use of the "chunked" transfer-coding (section 3.6),
1161 //   unless the message is terminated by closing the connection.
1162 // 3.If a Content-Length header field (section 14.13) is present, its
1163 //   decimal value in OCTETs represents both the entity-length and the
1164 //   transfer-length. The Content-Length header field MUST NOT be sent
1165 //   if these two lengths are different (i.e., if a Transfer-Encoding
1166 //   header field is present). If a message is received with both a
1167 //   Transfer-Encoding header field and a Content-Length header field,
1168 //   the latter MUST be ignored.
1169 // 4.If the message uses the media type "multipart/byteranges" ...
1170 // 5.By the server closing the connection.
1171 //
1172 // (NB: standards do not define "Transfer-Length:" _header_,
1173 // transfer-length above is just a concept).
1174
1175                 len += sprintf(iobuf + len,
1176 #if ENABLE_FEATURE_HTTPD_RANGES
1177                         "Accept-Ranges: bytes\r\n"
1178 #endif
1179                         "Last-Modified: %s\r\n"
1180         /* Because of 4.4 (5), we can forgo sending of "Content-Length"
1181          * since we close connection afterwards, but it helps clients
1182          * to e.g. estimate download times, show progress bars etc.
1183          * Theoretically we should not send it if page is compressed,
1184          * but de-facto standard is to send it (see comment below).
1185          */
1186                         "Content-Length: %"OFF_FMT"u\r\n",
1187                                 date_str,
1188                                 file_size
1189                 );
1190         }
1191
1192         /* This should be "Transfer-Encoding", not "Content-Encoding":
1193          * "data is compressed for transfer", not "data is an archive".
1194          * But many clients were not handling "Transfer-Encoding" correctly
1195          * (they were not uncompressing gzipped pages, tried to show
1196          * raw compressed data), and servers worked around it by using
1197          * "Content-Encoding" instead... and this become de-facto standard.
1198          * https://bugzilla.mozilla.org/show_bug.cgi?id=68517
1199          * https://bugs.chromium.org/p/chromium/issues/detail?id=94730
1200          */
1201         if (content_gzip)
1202                 len += sprintf(iobuf + len, "Content-Encoding: gzip\r\n");
1203
1204         iobuf[len++] = '\r';
1205         iobuf[len++] = '\n';
1206         if (infoString) {
1207                 len += sprintf(iobuf + len,
1208                                 "<HTML><HEAD><TITLE>%u %s</TITLE></HEAD>\n"
1209                                 "<BODY><H1>%u %s</H1>\n"
1210                                 "%s\n"
1211                                 "</BODY></HTML>\n",
1212                                 responseNum, responseString,
1213                                 responseNum, responseString,
1214                                 infoString
1215                 );
1216         }
1217         if (DEBUG) {
1218                 iobuf[len] = '\0';
1219                 fprintf(stderr, "headers: '%s'\n", iobuf);
1220         }
1221         if (full_write(STDOUT_FILENO, iobuf, len) != len) {
1222                 if (verbose > 1)
1223                         bb_simple_perror_msg("error");
1224                 log_and_exit();
1225         }
1226 }
1227
1228 static void send_headers_and_exit(int responseNum) NORETURN;
1229 static void send_headers_and_exit(int responseNum)
1230 {
1231         IF_FEATURE_HTTPD_GZIP(content_gzip = 0;)
1232         send_headers(responseNum);
1233         log_and_exit();
1234 }
1235
1236 /*
1237  * Read from the socket until '\n' or EOF.
1238  * '\r' chars are removed.
1239  * '\n' is replaced with NUL.
1240  * Return number of characters read or 0 if nothing is read
1241  * ('\r' and '\n' are not counted).
1242  * Data is returned in iobuf.
1243  */
1244 static unsigned get_line(void)
1245 {
1246         unsigned count;
1247         char c;
1248
1249         count = 0;
1250         while (1) {
1251                 if (hdr_cnt <= 0) {
1252                         alarm(HEADER_READ_TIMEOUT);
1253                         hdr_cnt = safe_read(STDIN_FILENO, hdr_buf, sizeof_hdr_buf);
1254                         if (hdr_cnt <= 0)
1255                                 goto ret;
1256                         hdr_ptr = hdr_buf;
1257                 }
1258                 hdr_cnt--;
1259                 c = *hdr_ptr++;
1260                 if (c == '\r')
1261                         continue;
1262                 if (c == '\n')
1263                         break;
1264                 iobuf[count] = c;
1265                 if (count < (IOBUF_SIZE - 1))      /* check overflow */
1266                         count++;
1267         }
1268  ret:
1269         iobuf[count] = '\0';
1270         return count;
1271 }
1272
1273 #if ENABLE_FEATURE_HTTPD_CGI || ENABLE_FEATURE_HTTPD_PROXY
1274
1275 /* gcc 4.2.1 fares better with NOINLINE */
1276 static NOINLINE void cgi_io_loop_and_exit(int fromCgi_rd, int toCgi_wr, int post_len) NORETURN;
1277 static NOINLINE void cgi_io_loop_and_exit(int fromCgi_rd, int toCgi_wr, int post_len)
1278 {
1279         enum { FROM_CGI = 1, TO_CGI = 2 }; /* indexes in pfd[] */
1280         struct pollfd pfd[3];
1281         int out_cnt; /* we buffer a bit of initial CGI output */
1282         int count;
1283
1284         /* iobuf is used for CGI -> network data,
1285          * hdr_buf is for network -> CGI data (POSTDATA) */
1286
1287         /* If CGI dies, we still want to correctly finish reading its output
1288          * and send it to the peer. So please no SIGPIPEs! */
1289         signal(SIGPIPE, SIG_IGN);
1290
1291         // We inconsistently handle a case when more POSTDATA from network
1292         // is coming than we expected. We may give *some part* of that
1293         // extra data to CGI.
1294
1295         //if (hdr_cnt > post_len) {
1296         //      /* We got more POSTDATA from network than we expected */
1297         //      hdr_cnt = post_len;
1298         //}
1299         post_len -= hdr_cnt;
1300         /* post_len - number of POST bytes not yet read from network */
1301
1302         /* NB: breaking out of this loop jumps to log_and_exit() */
1303         out_cnt = 0;
1304         pfd[FROM_CGI].fd = fromCgi_rd;
1305         pfd[FROM_CGI].events = POLLIN;
1306         pfd[TO_CGI].fd = toCgi_wr;
1307         while (1) {
1308                 /* Note: even pfd[0].events == 0 won't prevent
1309                  * revents == POLLHUP|POLLERR reports from closed stdin.
1310                  * Setting fd to -1 works: */
1311                 pfd[0].fd = -1;
1312                 pfd[0].events = POLLIN;
1313                 pfd[0].revents = 0; /* probably not needed, paranoia */
1314
1315                 /* We always poll this fd, thus kernel always sets revents: */
1316                 /*pfd[FROM_CGI].events = POLLIN; - moved out of loop */
1317                 /*pfd[FROM_CGI].revents = 0; - not needed */
1318
1319                 /* gcc-4.8.0 still doesnt fill two shorts with one insn :( */
1320                 /* http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47059 */
1321                 /* hopefully one day it will... */
1322                 pfd[TO_CGI].events = POLLOUT;
1323                 pfd[TO_CGI].revents = 0; /* needed! */
1324
1325                 if (toCgi_wr && hdr_cnt <= 0) {
1326                         if (post_len > 0) {
1327                                 /* Expect more POST data from network */
1328                                 pfd[0].fd = 0;
1329                         } else {
1330                                 /* post_len <= 0 && hdr_cnt <= 0:
1331                                  * no more POST data to CGI,
1332                                  * let CGI see EOF on CGI's stdin */
1333                                 if (toCgi_wr != fromCgi_rd)
1334                                         close(toCgi_wr);
1335                                 toCgi_wr = 0;
1336                         }
1337                 }
1338
1339                 /* Now wait on the set of sockets */
1340                 count = safe_poll(pfd, hdr_cnt > 0 ? TO_CGI+1 : FROM_CGI+1, -1);
1341                 if (count <= 0) {
1342 #if 0
1343                         if (safe_waitpid(pid, &status, WNOHANG) <= 0) {
1344                                 /* Weird. CGI didn't exit and no fd's
1345                                  * are ready, yet poll returned?! */
1346                                 continue;
1347                         }
1348                         if (DEBUG && WIFEXITED(status))
1349                                 bb_error_msg("CGI exited, status=%u", WEXITSTATUS(status));
1350                         if (DEBUG && WIFSIGNALED(status))
1351                                 bb_error_msg("CGI killed, signal=%u", WTERMSIG(status));
1352 #endif
1353                         break;
1354                 }
1355
1356                 if (pfd[TO_CGI].revents) {
1357                         /* hdr_cnt > 0 here due to the way poll() called */
1358                         /* Have data from peer and can write to CGI */
1359                         count = safe_write(toCgi_wr, hdr_ptr, hdr_cnt);
1360                         /* Doesn't happen, we dont use nonblocking IO here
1361                          *if (count < 0 && errno == EAGAIN) {
1362                          *      ...
1363                          *} else */
1364                         if (count > 0) {
1365                                 hdr_ptr += count;
1366                                 hdr_cnt -= count;
1367                         } else {
1368                                 /* EOF/broken pipe to CGI, stop piping POST data */
1369                                 hdr_cnt = post_len = 0;
1370                         }
1371                 }
1372
1373                 if (pfd[0].revents) {
1374                         /* post_len > 0 && hdr_cnt == 0 here */
1375                         /* We expect data, prev data portion is eaten by CGI
1376                          * and there *is* data to read from the peer
1377                          * (POSTDATA) */
1378                         //count = post_len > (int)sizeof_hdr_buf ? (int)sizeof_hdr_buf : post_len;
1379                         //count = safe_read(STDIN_FILENO, hdr_buf, count);
1380                         count = safe_read(STDIN_FILENO, hdr_buf, sizeof_hdr_buf);
1381                         if (count > 0) {
1382                                 hdr_cnt = count;
1383                                 hdr_ptr = hdr_buf;
1384                                 post_len -= count;
1385                         } else {
1386                                 /* no more POST data can be read */
1387                                 post_len = 0;
1388                         }
1389                 }
1390
1391                 if (pfd[FROM_CGI].revents) {
1392                         /* There is something to read from CGI */
1393                         char *rbuf = iobuf;
1394
1395                         /* Are we still buffering CGI output? */
1396                         if (out_cnt >= 0) {
1397                                 /* HTTP_200[] has single "\r\n" at the end.
1398                                  * According to http://hoohoo.ncsa.uiuc.edu/cgi/out.html,
1399                                  * CGI scripts MUST send their own header terminated by
1400                                  * empty line, then data. That's why we have only one
1401                                  * <cr><lf> pair here. We will output "200 OK" line
1402                                  * if needed, but CGI still has to provide blank line
1403                                  * between header and body */
1404
1405                                 /* Must use safe_read, not full_read, because
1406                                  * CGI may output a few first bytes and then wait
1407                                  * for POSTDATA without closing stdout.
1408                                  * With full_read we may wait here forever. */
1409                                 count = safe_read(fromCgi_rd, rbuf + out_cnt, IOBUF_SIZE - 8);
1410                                 if (count <= 0) {
1411                                         /* eof (or error) and there was no "HTTP",
1412                                          * send "HTTP/1.0 200 OK\r\n", then send received data */
1413                                         if (out_cnt) {
1414                                                 full_write(STDOUT_FILENO, HTTP_200, sizeof(HTTP_200)-1);
1415                                                 full_write(STDOUT_FILENO, rbuf, out_cnt);
1416                                         }
1417                                         break; /* CGI stdout is closed, exiting */
1418                                 }
1419                                 out_cnt += count;
1420                                 count = 0;
1421                                 /* "Status" header format is: "Status: 302 Redirected\r\n" */
1422                                 if (out_cnt >= 8 && memcmp(rbuf, "Status: ", 8) == 0) {
1423                                         /* send "HTTP/1.0 " */
1424                                         if (full_write(STDOUT_FILENO, HTTP_200, 9) != 9)
1425                                                 break;
1426                                         /* skip "Status: " (including space, sending "HTTP/1.0  NNN" is wrong) */
1427                                         rbuf += 8;
1428                                         count = out_cnt - 8;
1429                                         out_cnt = -1; /* buffering off */
1430                                 } else if (out_cnt >= 4) {
1431                                         /* Did CGI add "HTTP"? */
1432                                         if (memcmp(rbuf, HTTP_200, 4) != 0) {
1433                                                 /* there is no "HTTP", do it ourself */
1434                                                 if (full_write(STDOUT_FILENO, HTTP_200, sizeof(HTTP_200)-1) != sizeof(HTTP_200)-1)
1435                                                         break;
1436                                         }
1437                                         /* Commented out:
1438                                         if (!strstr(rbuf, "ontent-")) {
1439                                                 full_write(s, "Content-type: text/plain\r\n\r\n", 28);
1440                                         }
1441                                          * Counter-example of valid CGI without Content-type:
1442                                          * echo -en "HTTP/1.0 302 Found\r\n"
1443                                          * echo -en "Location: http://www.busybox.net\r\n"
1444                                          * echo -en "\r\n"
1445                                          */
1446                                         count = out_cnt;
1447                                         out_cnt = -1; /* buffering off */
1448                                 }
1449                         } else {
1450                                 count = safe_read(fromCgi_rd, rbuf, IOBUF_SIZE);
1451                                 if (count <= 0)
1452                                         break;  /* eof (or error) */
1453                         }
1454                         if (full_write(STDOUT_FILENO, rbuf, count) != count)
1455                                 break;
1456                         if (DEBUG)
1457                                 fprintf(stderr, "cgi read %d bytes: '%.*s'\n", count, count, rbuf);
1458                 } /* if (pfd[FROM_CGI].revents) */
1459         } /* while (1) */
1460         log_and_exit();
1461 }
1462 #endif
1463
1464 #if ENABLE_FEATURE_HTTPD_CGI
1465
1466 static void setenv1(const char *name, const char *value)
1467 {
1468         setenv(name, value ? value : "", 1);
1469 }
1470
1471 /*
1472  * Spawn CGI script, forward CGI's stdin/out <=> network
1473  *
1474  * Environment variables are set up and the script is invoked with pipes
1475  * for stdin/stdout.  If a POST is being done the script is fed the POST
1476  * data in addition to setting the QUERY_STRING variable (for GETs or POSTs).
1477  *
1478  * Parameters:
1479  * const char *url              The requested URL (with leading /).
1480  * const char *orig_uri         The original URI before rewriting (if any)
1481  * int post_len                 Length of the POST body.
1482  */
1483 static void send_cgi_and_exit(
1484                 const char *url,
1485                 const char *orig_uri,
1486                 const char *request,
1487                 int post_len) NORETURN;
1488 static void send_cgi_and_exit(
1489                 const char *url,
1490                 const char *orig_uri,
1491                 const char *request,
1492                 int post_len)
1493 {
1494         struct fd_pair fromCgi;  /* CGI -> httpd pipe */
1495         struct fd_pair toCgi;    /* httpd -> CGI pipe */
1496         char *script, *last_slash;
1497         int pid;
1498
1499         /* Make a copy. NB: caller guarantees:
1500          * url[0] == '/', url[1] != '/' */
1501         url = xstrdup(url);
1502
1503         /*
1504          * We are mucking with environment _first_ and then vfork/exec,
1505          * this allows us to use vfork safely. Parent doesn't care about
1506          * these environment changes anyway.
1507          */
1508
1509         /* Check for [dirs/]script.cgi/PATH_INFO */
1510         last_slash = script = (char*)url;
1511         while ((script = strchr(script + 1, '/')) != NULL) {
1512                 int dir;
1513                 *script = '\0';
1514                 dir = is_directory(url + 1, /*followlinks:*/ 1);
1515                 *script = '/';
1516                 if (!dir) {
1517                         /* not directory, found script.cgi/PATH_INFO */
1518                         break;
1519                 }
1520                 /* is directory, find next '/' */
1521                 last_slash = script;
1522         }
1523         setenv1("PATH_INFO", script);   /* set to /PATH_INFO or "" */
1524         setenv1("REQUEST_METHOD", request);
1525         if (g_query) {
1526                 putenv(xasprintf("%s=%s?%s", "REQUEST_URI", orig_uri, g_query));
1527         } else {
1528                 setenv1("REQUEST_URI", orig_uri);
1529         }
1530         if (script != NULL)
1531                 *script = '\0';         /* cut off /PATH_INFO */
1532
1533         /* SCRIPT_FILENAME is required by PHP in CGI mode */
1534         if (home_httpd[0] == '/') {
1535                 char *fullpath = concat_path_file(home_httpd, url);
1536                 setenv1("SCRIPT_FILENAME", fullpath);
1537         }
1538         /* set SCRIPT_NAME as full path: /cgi-bin/dirs/script.cgi */
1539         setenv1("SCRIPT_NAME", url);
1540         /* http://hoohoo.ncsa.uiuc.edu/cgi/env.html:
1541          * QUERY_STRING: The information which follows the ? in the URL
1542          * which referenced this script. This is the query information.
1543          * It should not be decoded in any fashion. This variable
1544          * should always be set when there is query information,
1545          * regardless of command line decoding. */
1546         /* (Older versions of bbox seem to do some decoding) */
1547         setenv1("QUERY_STRING", g_query);
1548         putenv((char*)"SERVER_SOFTWARE=busybox httpd/"BB_VER);
1549         putenv((char*)"SERVER_PROTOCOL=HTTP/1.0");
1550         putenv((char*)"GATEWAY_INTERFACE=CGI/1.1");
1551         /* Having _separate_ variables for IP and port defeats
1552          * the purpose of having socket abstraction. Which "port"
1553          * are you using on Unix domain socket?
1554          * IOW - REMOTE_PEER="1.2.3.4:56" makes much more sense.
1555          * Oh well... */
1556         {
1557                 char *p = rmt_ip_str ? rmt_ip_str : (char*)"";
1558                 char *cp = strrchr(p, ':');
1559                 if (ENABLE_FEATURE_IPV6 && cp && strchr(cp, ']'))
1560                         cp = NULL;
1561                 if (cp) *cp = '\0'; /* delete :PORT */
1562                 setenv1("REMOTE_ADDR", p);
1563                 if (cp) {
1564                         *cp = ':';
1565 #if ENABLE_FEATURE_HTTPD_SET_REMOTE_PORT_TO_ENV
1566                         setenv1("REMOTE_PORT", cp + 1);
1567 #endif
1568                 }
1569         }
1570         if (post_len)
1571                 putenv(xasprintf("CONTENT_LENGTH=%u", post_len));
1572 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
1573         if (remoteuser) {
1574                 setenv1("REMOTE_USER", remoteuser);
1575                 putenv((char*)"AUTH_TYPE=Basic");
1576         }
1577 #endif
1578         /* setenv1("SERVER_NAME", safe_gethostname()); - don't do this,
1579          * just run "env SERVER_NAME=xyz httpd ..." instead */
1580
1581         xpiped_pair(fromCgi);
1582         xpiped_pair(toCgi);
1583
1584         pid = vfork();
1585         if (pid < 0) {
1586                 /* TODO: log perror? */
1587                 log_and_exit();
1588         }
1589
1590         if (pid == 0) {
1591                 /* Child process */
1592                 char *argv[3];
1593
1594                 xfunc_error_retval = 242;
1595
1596                 /* NB: close _first_, then move fds! */
1597                 close(toCgi.wr);
1598                 close(fromCgi.rd);
1599                 xmove_fd(toCgi.rd, 0);  /* replace stdin with the pipe */
1600                 xmove_fd(fromCgi.wr, 1);  /* replace stdout with the pipe */
1601                 /* User seeing stderr output can be a security problem.
1602                  * If CGI really wants that, it can always do dup itself. */
1603                 /* dup2(1, 2); */
1604
1605                 /* Chdiring to script's dir */
1606                 script = last_slash;
1607                 if (script != url) { /* paranoia */
1608                         *script = '\0';
1609                         if (chdir(url + 1) != 0) {
1610                                 bb_perror_msg("can't change directory to '%s'", url + 1);
1611                                 goto error_execing_cgi;
1612                         }
1613                         // not needed: *script = '/';
1614                 }
1615                 script++;
1616
1617                 /* set argv[0] to name without path */
1618                 argv[0] = script;
1619                 argv[1] = NULL;
1620
1621 #if ENABLE_FEATURE_HTTPD_CONFIG_WITH_SCRIPT_INTERPR
1622                 {
1623                         char *suffix = strrchr(script, '.');
1624
1625                         if (suffix) {
1626                                 Htaccess *cur;
1627                                 for (cur = script_i; cur; cur = cur->next) {
1628                                         if (strcmp(cur->before_colon + 1, suffix) == 0) {
1629                                                 /* found interpreter name */
1630                                                 argv[0] = cur->after_colon;
1631                                                 argv[1] = script;
1632                                                 argv[2] = NULL;
1633                                                 break;
1634                                         }
1635                                 }
1636                         }
1637                 }
1638 #endif
1639                 /* restore default signal dispositions for CGI process */
1640                 bb_signals(0
1641                         | (1 << SIGCHLD)
1642                         | (1 << SIGPIPE)
1643                         | (1 << SIGHUP)
1644                         , SIG_DFL);
1645
1646                 /* _NOT_ execvp. We do not search PATH. argv[0] is a filename
1647                  * without any dir components and will only match a file
1648                  * in the current directory */
1649                 execv(argv[0], argv);
1650                 if (verbose)
1651                         bb_perror_msg("can't execute '%s'", argv[0]);
1652  error_execing_cgi:
1653                 /* send to stdout
1654                  * (we are CGI here, our stdout is pumped to the net) */
1655                 send_headers_and_exit(HTTP_NOT_FOUND);
1656         } /* end child */
1657
1658         /* Parent process */
1659
1660         /* Restore variables possibly changed by child */
1661         xfunc_error_retval = 0;
1662
1663         /* Pump data */
1664         close(fromCgi.wr);
1665         close(toCgi.rd);
1666         cgi_io_loop_and_exit(fromCgi.rd, toCgi.wr, post_len);
1667 }
1668
1669 #endif          /* FEATURE_HTTPD_CGI */
1670
1671 /*
1672  * Send a file response to a HTTP request, and exit
1673  *
1674  * Parameters:
1675  * const char *url  The requested URL (with leading /).
1676  * what             What to send (headers/body/both).
1677  */
1678 static NOINLINE void send_file_and_exit(const char *url, int what)
1679 {
1680         char *suffix;
1681         int fd;
1682         ssize_t count;
1683
1684         if (content_gzip) {
1685                 /* does <url>.gz exist? Then use it instead */
1686                 char *gzurl = xasprintf("%s.gz", url);
1687                 fd = open(gzurl, O_RDONLY);
1688                 free(gzurl);
1689                 if (fd != -1) {
1690                         struct stat sb;
1691                         fstat(fd, &sb);
1692                         file_size = sb.st_size;
1693                         last_mod = sb.st_mtime;
1694                 } else {
1695                         IF_FEATURE_HTTPD_GZIP(content_gzip = 0;)
1696                         fd = open(url, O_RDONLY);
1697                 }
1698         } else {
1699                 fd = open(url, O_RDONLY);
1700         }
1701         if (fd < 0) {
1702                 if (DEBUG)
1703                         bb_perror_msg("can't open '%s'", url);
1704                 /* Error pages are sent by using send_file_and_exit(SEND_BODY).
1705                  * IOW: it is unsafe to call send_headers_and_exit
1706                  * if what is SEND_BODY! Can recurse! */
1707                 if (what != SEND_BODY)
1708                         send_headers_and_exit(HTTP_NOT_FOUND);
1709                 log_and_exit();
1710         }
1711         /* If you want to know about EPIPE below
1712          * (happens if you abort downloads from local httpd): */
1713         signal(SIGPIPE, SIG_IGN);
1714
1715         /* If not found, default is to not send "Content-type:" */
1716         /*found_mime_type = NULL; - already is */
1717         suffix = strrchr(url, '.');
1718         if (suffix) {
1719                 static const char suffixTable[] ALIGN1 =
1720                         /* Shorter suffix must be first:
1721                          * ".html.htm" will fail for ".htm"
1722                          */
1723                         ".txt.h.c.cc.cpp\0" "text/plain\0"
1724                         /* .htm line must be after .h line */
1725                         ".htm.html\0" "text/html\0"
1726                         ".jpg.jpeg\0" "image/jpeg\0"
1727                         ".gif\0"      "image/gif\0"
1728                         ".png\0"      "image/png\0"
1729                         ".svg\0"      "image/svg+xml\0"
1730                         /* .css line must be after .c line */
1731                         ".css\0"      "text/css\0"
1732                         ".js\0"       "application/javascript\0"
1733                         ".wav\0"      "audio/wav\0"
1734                         ".avi\0"      "video/x-msvideo\0"
1735                         ".qt.mov\0"   "video/quicktime\0"
1736                         ".mpe.mpeg\0" "video/mpeg\0"
1737                         ".mid.midi\0" "audio/midi\0"
1738                         ".mp3\0"      "audio/mpeg\0"
1739 #if 0  /* unpopular */
1740                         ".au\0"       "audio/basic\0"
1741                         ".pac\0"      "application/x-ns-proxy-autoconfig\0"
1742                         ".vrml.wrl\0" "model/vrml\0"
1743 #endif
1744                         /* compiler adds another "\0" here */
1745                 ;
1746                 Htaccess *cur;
1747
1748                 /* Examine built-in table */
1749                 const char *table = suffixTable;
1750                 const char *table_next;
1751                 for (; *table; table = table_next) {
1752                         const char *try_suffix;
1753                         const char *mime_type;
1754                         mime_type  = table + strlen(table) + 1;
1755                         table_next = mime_type + strlen(mime_type) + 1;
1756                         try_suffix = strstr(table, suffix);
1757                         if (!try_suffix)
1758                                 continue;
1759                         try_suffix += strlen(suffix);
1760                         if (*try_suffix == '\0' || *try_suffix == '.') {
1761                                 found_mime_type = mime_type;
1762                                 break;
1763                         }
1764                         /* Example: strstr(table, ".av") != NULL, but it
1765                          * does not match ".avi" after all and we end up here.
1766                          * The table is arranged so that in this case we know
1767                          * that it can't match anything in the following lines,
1768                          * and we stop the search: */
1769                         break;
1770                 }
1771                 /* ...then user's table */
1772                 for (cur = mime_a; cur; cur = cur->next) {
1773                         if (strcmp(cur->before_colon, suffix) == 0) {
1774                                 found_mime_type = cur->after_colon;
1775                                 break;
1776                         }
1777                 }
1778         }
1779
1780         if (DEBUG)
1781                 bb_error_msg("sending file '%s' content-type: %s",
1782                         url, found_mime_type);
1783
1784 #if ENABLE_FEATURE_HTTPD_RANGES
1785         if (what == SEND_BODY /* err pages and ranges don't mix */
1786          || content_gzip /* we are sending compressed page: can't do ranges */  ///why?
1787         ) {
1788                 range_start = -1;
1789         }
1790         range_len = MAXINT(off_t);
1791         if (range_start >= 0) {
1792                 if (!range_end || range_end > file_size - 1) {
1793                         range_end = file_size - 1;
1794                 }
1795                 if (range_end < range_start
1796                  || lseek(fd, range_start, SEEK_SET) != range_start
1797                 ) {
1798                         lseek(fd, 0, SEEK_SET);
1799                         range_start = -1;
1800                 } else {
1801                         range_len = range_end - range_start + 1;
1802                         send_headers(HTTP_PARTIAL_CONTENT);
1803                         what = SEND_BODY;
1804                 }
1805         }
1806 #endif
1807         if (what & SEND_HEADERS)
1808                 send_headers(HTTP_OK);
1809 #if ENABLE_FEATURE_USE_SENDFILE
1810         {
1811                 off_t offset = range_start;
1812                 while (1) {
1813                         /* sz is rounded down to 64k */
1814                         ssize_t sz = MAXINT(ssize_t) - 0xffff;
1815                         IF_FEATURE_HTTPD_RANGES(if (sz > range_len) sz = range_len;)
1816                         count = sendfile(STDOUT_FILENO, fd, &offset, sz);
1817                         if (count < 0) {
1818                                 if (offset == range_start)
1819                                         break; /* fall back to read/write loop */
1820                                 goto fin;
1821                         }
1822                         IF_FEATURE_HTTPD_RANGES(range_len -= count;)
1823                         if (count == 0 || range_len == 0)
1824                                 log_and_exit();
1825                 }
1826         }
1827 #endif
1828         while ((count = safe_read(fd, iobuf, IOBUF_SIZE)) > 0) {
1829                 ssize_t n;
1830                 IF_FEATURE_HTTPD_RANGES(if (count > range_len) count = range_len;)
1831                 n = full_write(STDOUT_FILENO, iobuf, count);
1832                 if (count != n)
1833                         break;
1834                 IF_FEATURE_HTTPD_RANGES(range_len -= count;)
1835                 if (range_len == 0)
1836                         break;
1837         }
1838         if (count < 0) {
1839  IF_FEATURE_USE_SENDFILE(fin:)
1840                 if (verbose > 1)
1841                         bb_simple_perror_msg("error");
1842         }
1843         log_and_exit();
1844 }
1845
1846 static void if_ip_denied_send_HTTP_FORBIDDEN_and_exit(unsigned remote_ip)
1847 {
1848         Htaccess_IP *cur;
1849
1850         for (cur = ip_a_d; cur; cur = cur->next) {
1851 #if DEBUG
1852                 fprintf(stderr,
1853                         "checkPermIP: '%s' ? '%u.%u.%u.%u/%u.%u.%u.%u'\n",
1854                         rmt_ip_str,
1855                         (unsigned char)(cur->ip >> 24),
1856                         (unsigned char)(cur->ip >> 16),
1857                         (unsigned char)(cur->ip >> 8),
1858                         (unsigned char)(cur->ip),
1859                         (unsigned char)(cur->mask >> 24),
1860                         (unsigned char)(cur->mask >> 16),
1861                         (unsigned char)(cur->mask >> 8),
1862                         (unsigned char)(cur->mask)
1863                 );
1864 #endif
1865                 if ((remote_ip & cur->mask) == cur->ip) {
1866                         if (cur->allow_deny == 'A')
1867                                 return;
1868                         send_headers_and_exit(HTTP_FORBIDDEN);
1869                 }
1870         }
1871
1872         if (flg_deny_all) /* depends on whether we saw "D:*" */
1873                 send_headers_and_exit(HTTP_FORBIDDEN);
1874 }
1875
1876 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
1877
1878 # if ENABLE_PAM
1879 struct pam_userinfo {
1880         const char *name;
1881         const char *pw;
1882 };
1883
1884 static int pam_talker(int num_msg,
1885                 const struct pam_message **msg,
1886                 struct pam_response **resp,
1887                 void *appdata_ptr)
1888 {
1889         int i;
1890         struct pam_userinfo *userinfo = (struct pam_userinfo *) appdata_ptr;
1891         struct pam_response *response;
1892
1893         if (!resp || !msg || !userinfo)
1894                 return PAM_CONV_ERR;
1895
1896         /* allocate memory to store response */
1897         response = xzalloc(num_msg * sizeof(*response));
1898
1899         /* copy values */
1900         for (i = 0; i < num_msg; i++) {
1901                 const char *s;
1902
1903                 switch (msg[i]->msg_style) {
1904                 case PAM_PROMPT_ECHO_ON:
1905                         s = userinfo->name;
1906                         break;
1907                 case PAM_PROMPT_ECHO_OFF:
1908                         s = userinfo->pw;
1909                         break;
1910                 case PAM_ERROR_MSG:
1911                 case PAM_TEXT_INFO:
1912                         s = "";
1913                         break;
1914                 default:
1915                         free(response);
1916                         return PAM_CONV_ERR;
1917                 }
1918                 response[i].resp = xstrdup(s);
1919                 if (PAM_SUCCESS != 0)
1920                         response[i].resp_retcode = PAM_SUCCESS;
1921         }
1922         *resp = response;
1923         return PAM_SUCCESS;
1924 }
1925 # endif
1926
1927 /*
1928  * Config file entries are of the form "/<path>:<user>:<passwd>".
1929  * If config file has no prefix match for path, access is allowed.
1930  *
1931  * path                 The file path
1932  * user_and_passwd      "user:passwd" to validate
1933  *
1934  * Returns 1 if user_and_passwd is OK.
1935  */
1936 static int check_user_passwd(const char *path, char *user_and_passwd)
1937 {
1938         Htaccess *cur;
1939         const char *prev = NULL;
1940
1941         for (cur = g_auth; cur; cur = cur->next) {
1942                 const char *dir_prefix;
1943                 size_t len;
1944                 int r;
1945
1946                 dir_prefix = cur->before_colon;
1947
1948                 /* WHY? */
1949                 /* If already saw a match, don't accept other different matches */
1950                 if (prev && strcmp(prev, dir_prefix) != 0)
1951                         continue;
1952
1953                 if (DEBUG)
1954                         fprintf(stderr, "checkPerm: '%s' ? '%s'\n", dir_prefix, user_and_passwd);
1955
1956                 /* If it's not a prefix match, continue searching */
1957                 len = strlen(dir_prefix);
1958                 if (len != 1 /* dir_prefix "/" matches all, don't need to check */
1959                  && (strncmp(dir_prefix, path, len) != 0
1960                     || (path[len] != '/' && path[len] != '\0')
1961                     )
1962                 ) {
1963                         continue;
1964                 }
1965
1966                 /* Path match found */
1967                 prev = dir_prefix;
1968
1969                 if (ENABLE_FEATURE_HTTPD_AUTH_MD5) {
1970                         char *colon_after_user;
1971                         const char *passwd;
1972 # if ENABLE_FEATURE_SHADOWPASSWDS && !ENABLE_PAM
1973                         char sp_buf[256];
1974 # endif
1975
1976                         colon_after_user = strchr(user_and_passwd, ':');
1977                         if (!colon_after_user)
1978                                 goto bad_input;
1979
1980                         /* compare "user:" */
1981                         if (cur->after_colon[0] != '*'
1982                          && strncmp(cur->after_colon, user_and_passwd,
1983                                         colon_after_user - user_and_passwd + 1) != 0
1984                         ) {
1985                                 continue;
1986                         }
1987                         /* this cfg entry is '*' or matches username from peer */
1988
1989                         passwd = strchr(cur->after_colon, ':');
1990                         if (!passwd)
1991                                 goto bad_input;
1992                         passwd++;
1993                         if (passwd[0] == '*') {
1994 # if ENABLE_PAM
1995                                 struct pam_userinfo userinfo;
1996                                 struct pam_conv conv_info = { &pam_talker, (void *) &userinfo };
1997                                 pam_handle_t *pamh;
1998
1999                                 *colon_after_user = '\0';
2000                                 userinfo.name = user_and_passwd;
2001                                 userinfo.pw = colon_after_user + 1;
2002                                 r = pam_start("httpd", user_and_passwd, &conv_info, &pamh) != PAM_SUCCESS;
2003                                 if (r == 0) {
2004                                         r = pam_authenticate(pamh, PAM_DISALLOW_NULL_AUTHTOK) != PAM_SUCCESS
2005                                          || pam_acct_mgmt(pamh, PAM_DISALLOW_NULL_AUTHTOK)    != PAM_SUCCESS
2006                                         ;
2007                                         pam_end(pamh, PAM_SUCCESS);
2008                                 }
2009                                 *colon_after_user = ':';
2010                                 goto end_check_passwd;
2011 # else
2012 #  if ENABLE_FEATURE_SHADOWPASSWDS
2013                                 /* Using _r function to avoid pulling in static buffers */
2014                                 struct spwd spw;
2015 #  endif
2016                                 struct passwd *pw;
2017
2018                                 *colon_after_user = '\0';
2019                                 pw = getpwnam(user_and_passwd);
2020                                 *colon_after_user = ':';
2021                                 if (!pw || !pw->pw_passwd)
2022                                         continue;
2023                                 passwd = pw->pw_passwd;
2024 #  if ENABLE_FEATURE_SHADOWPASSWDS
2025                                 if ((passwd[0] == 'x' || passwd[0] == '*') && !passwd[1]) {
2026                                         /* getspnam_r may return 0 yet set result to NULL.
2027                                          * At least glibc 2.4 does this. Be extra paranoid here. */
2028                                         struct spwd *result = NULL;
2029                                         r = getspnam_r(pw->pw_name, &spw, sp_buf, sizeof(sp_buf), &result);
2030                                         if (r == 0 && result)
2031                                                 passwd = result->sp_pwdp;
2032                                 }
2033 #  endif
2034                                 /* In this case, passwd is ALWAYS encrypted:
2035                                  * it came from /etc/passwd or /etc/shadow!
2036                                  */
2037                                 goto check_encrypted;
2038 # endif /* ENABLE_PAM */
2039                         }
2040                         /* Else: passwd is from httpd.conf, it is either plaintext or encrypted */
2041
2042                         if (passwd[0] == '$' && isdigit(passwd[1])) {
2043                                 char *encrypted;
2044 # if !ENABLE_PAM
2045  check_encrypted:
2046 # endif
2047                                 /* encrypt pwd from peer and check match with local one */
2048                                 encrypted = pw_encrypt(
2049                                         /* pwd (from peer): */  colon_after_user + 1,
2050                                         /* salt: */ passwd,
2051                                         /* cleanup: */ 0
2052                                 );
2053                                 r = strcmp(encrypted, passwd);
2054                                 free(encrypted);
2055                         } else {
2056                                 /* local passwd is from httpd.conf and it's plaintext */
2057                                 r = strcmp(colon_after_user + 1, passwd);
2058                         }
2059                         goto end_check_passwd;
2060                 }
2061  bad_input:
2062                 /* Comparing plaintext "user:pass" in one go */
2063                 r = strcmp(cur->after_colon, user_and_passwd);
2064  end_check_passwd:
2065                 if (r == 0) {
2066                         remoteuser = xstrndup(user_and_passwd,
2067                                 strchrnul(user_and_passwd, ':') - user_and_passwd
2068                         );
2069                         return 1; /* Ok */
2070                 }
2071         } /* for */
2072
2073         /* 0(bad) if prev is set: matches were found but passwd was wrong */
2074         return (prev == NULL);
2075 }
2076 #endif  /* FEATURE_HTTPD_BASIC_AUTH */
2077
2078 #if ENABLE_FEATURE_HTTPD_PROXY
2079 static Htaccess_Proxy *find_proxy_entry(const char *url)
2080 {
2081         Htaccess_Proxy *p;
2082         for (p = proxy; p; p = p->next) {
2083                 if (is_prefixed_with(url, p->url_from))
2084                         return p;
2085         }
2086         return NULL;
2087 }
2088 #endif
2089
2090 /*
2091  * Handle timeouts
2092  */
2093 static void send_REQUEST_TIMEOUT_and_exit(int sig) NORETURN;
2094 static void send_REQUEST_TIMEOUT_and_exit(int sig UNUSED_PARAM)
2095 {
2096         send_headers_and_exit(HTTP_REQUEST_TIMEOUT);
2097 }
2098
2099 /*
2100  * Handle an incoming http request and exit.
2101  */
2102 static void handle_incoming_and_exit(const len_and_sockaddr *fromAddr) NORETURN;
2103 static void handle_incoming_and_exit(const len_and_sockaddr *fromAddr)
2104 {
2105         static const char request_GET[] ALIGN1 = "GET";
2106         struct stat sb;
2107         char *urlcopy;
2108         char *urlp;
2109         char *tptr;
2110         unsigned remote_ip;
2111 #if ENABLE_FEATURE_HTTPD_CGI
2112         unsigned total_headers_len;
2113 #endif
2114 #if ENABLE_FEATURE_HTTPD_CGI
2115         static const char request_HEAD[] ALIGN1 = "HEAD";
2116         const char *prequest;
2117         unsigned long length = 0;
2118         enum CGI_type cgi_type = CGI_NONE;
2119 #elif ENABLE_FEATURE_HTTPD_PROXY
2120 #define prequest request_GET
2121         unsigned long length = 0;
2122 #endif
2123 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
2124         smallint authorized = -1;
2125 #endif
2126         char *HTTP_slash;
2127
2128         /* Allocation of iobuf is postponed until now
2129          * (IOW, server process doesn't need to waste 8k) */
2130         iobuf = xmalloc(IOBUF_SIZE);
2131
2132         remote_ip = 0;
2133         if (fromAddr->u.sa.sa_family == AF_INET) {
2134                 remote_ip = ntohl(fromAddr->u.sin.sin_addr.s_addr);
2135         }
2136 #if ENABLE_FEATURE_IPV6
2137         if (fromAddr->u.sa.sa_family == AF_INET6
2138          && fromAddr->u.sin6.sin6_addr.s6_addr32[0] == 0
2139          && fromAddr->u.sin6.sin6_addr.s6_addr32[1] == 0
2140          && ntohl(fromAddr->u.sin6.sin6_addr.s6_addr32[2]) == 0xffff)
2141                 remote_ip = ntohl(fromAddr->u.sin6.sin6_addr.s6_addr32[3]);
2142 #endif
2143         if (ENABLE_FEATURE_HTTPD_CGI || DEBUG || verbose) {
2144                 /* NB: can be NULL (user runs httpd -i by hand?) */
2145                 rmt_ip_str = xmalloc_sockaddr2dotted(&fromAddr->u.sa);
2146         }
2147         if (verbose) {
2148                 /* this trick makes -v logging much simpler */
2149                 if (rmt_ip_str)
2150                         applet_name = rmt_ip_str;
2151                 if (verbose > 2)
2152                         bb_simple_error_msg("connected");
2153         }
2154         if_ip_denied_send_HTTP_FORBIDDEN_and_exit(remote_ip);
2155
2156         /* Install timeout handler. get_line() needs it. */
2157         signal(SIGALRM, send_REQUEST_TIMEOUT_and_exit);
2158
2159         if (!get_line()) /* EOF or error or empty line */
2160                 send_headers_and_exit(HTTP_BAD_REQUEST);
2161
2162         /* Determine type of request (GET/POST) */
2163         // rfc2616: method and URI is separated by exactly one space
2164         //urlp = strpbrk(iobuf, " \t"); - no, tab isn't allowed
2165         urlp = strchr(iobuf, ' ');
2166         if (urlp == NULL)
2167                 send_headers_and_exit(HTTP_BAD_REQUEST);
2168         *urlp++ = '\0';
2169 #if ENABLE_FEATURE_HTTPD_CGI
2170         prequest = request_GET;
2171         if (strcasecmp(iobuf, prequest) != 0) {
2172                 prequest = request_HEAD;
2173                 if (strcasecmp(iobuf, prequest) != 0) {
2174                         prequest = "POST";
2175                         if (strcasecmp(iobuf, prequest) != 0)
2176                                 send_headers_and_exit(HTTP_NOT_IMPLEMENTED);
2177                 }
2178         }
2179 #else
2180         if (strcasecmp(iobuf, request_GET) != 0)
2181                 send_headers_and_exit(HTTP_NOT_IMPLEMENTED);
2182 #endif
2183         // rfc2616: method and URI is separated by exactly one space
2184         //urlp = skip_whitespace(urlp); - should not be necessary
2185         if (urlp[0] != '/')
2186                 send_headers_and_exit(HTTP_BAD_REQUEST);
2187
2188         /* Find end of URL */
2189         HTTP_slash = strchr(urlp, ' ');
2190         /* Is it " HTTP/"? */
2191         if (!HTTP_slash || strncmp(HTTP_slash + 1, HTTP_200, 5) != 0)
2192                 send_headers_and_exit(HTTP_BAD_REQUEST);
2193         *HTTP_slash++ = '\0';
2194
2195         /* Copy URL from after "GET "/"POST " to stack-allocated char[] */
2196         urlcopy = alloca((HTTP_slash - urlp) + 2 + strlen(index_page));
2197         /*if (urlcopy == NULL)
2198          *      send_headers_and_exit(HTTP_INTERNAL_SERVER_ERROR);*/
2199         strcpy(urlcopy, urlp);
2200         /* NB: urlcopy ptr is never changed after this */
2201
2202 #if ENABLE_FEATURE_HTTPD_PROXY
2203         {
2204                 int proxy_fd;
2205                 len_and_sockaddr *lsa;
2206                 Htaccess_Proxy *proxy_entry = find_proxy_entry(urlcopy);
2207
2208                 if (proxy_entry) {
2209                         if (verbose > 1)
2210                                 bb_error_msg("proxy:%s", urlcopy);
2211                         lsa = host2sockaddr(proxy_entry->host_port, 80);
2212                         if (!lsa)
2213                                 send_headers_and_exit(HTTP_INTERNAL_SERVER_ERROR);
2214                         proxy_fd = socket(lsa->u.sa.sa_family, SOCK_STREAM, 0);
2215                         if (proxy_fd < 0)
2216                                 send_headers_and_exit(HTTP_INTERNAL_SERVER_ERROR);
2217                         if (connect(proxy_fd, &lsa->u.sa, lsa->len) < 0)
2218                                 send_headers_and_exit(HTTP_INTERNAL_SERVER_ERROR);
2219                         /* Disable peer header reading timeout */
2220                         alarm(0);
2221                         /* Config directive was of the form:
2222                          *   P:/url:[http://]hostname[:port]/new/path
2223                          * When /urlSFX is requested, reverse proxy it
2224                          * to http://hostname[:port]/new/pathSFX
2225                          */
2226                         fdprintf(proxy_fd, "%s %s%s %s\r\n",
2227                                         prequest, /* "GET" or "POST" */
2228                                         proxy_entry->url_to, /* "/new/path" */
2229                                         urlcopy + strlen(proxy_entry->url_from), /* "SFX" */
2230                                         HTTP_slash /* "HTTP/xyz" */
2231                         );
2232                         cgi_io_loop_and_exit(proxy_fd, proxy_fd, /*max POST length:*/ INT_MAX);
2233                 }
2234         }
2235 #endif
2236
2237         /* Extract url args if present */
2238         g_query = strchr(urlcopy, '?');
2239         if (g_query)
2240                 *g_query++ = '\0';
2241
2242         /* Decode URL escape sequences */
2243         tptr = percent_decode_in_place(urlcopy, /*strict:*/ 1);
2244         if (tptr == NULL)
2245                 send_headers_and_exit(HTTP_BAD_REQUEST);
2246         if (tptr == urlcopy + 1) {
2247                 /* '/' or NUL is encoded */
2248                 send_headers_and_exit(HTTP_NOT_FOUND);
2249         }
2250
2251         /* Canonicalize path */
2252         /* Algorithm stolen from libbb bb_simplify_path(),
2253          * but don't strdup, retain trailing slash, protect root */
2254         urlp = tptr = urlcopy;
2255         for (;;) {
2256                 if (*urlp == '/') {
2257                         /* skip duplicate (or initial) slash */
2258                         if (*tptr == '/') {
2259                                 goto next_char;
2260                         }
2261                         if (*tptr == '.') {
2262                                 if (tptr[1] == '.' && (tptr[2] == '/' || tptr[2] == '\0')) {
2263                                         /* "..": be careful */
2264                                         /* protect root */
2265                                         if (urlp == urlcopy)
2266                                                 send_headers_and_exit(HTTP_BAD_REQUEST);
2267                                         /* omit previous dir */
2268                                         while (*--urlp != '/')
2269                                                 continue;
2270                                         /* skip to "./" or ".<NUL>" */
2271                                         tptr++;
2272                                 }
2273                                 if (tptr[1] == '/' || tptr[1] == '\0') {
2274                                         /* skip extra "/./" */
2275                                         goto next_char;
2276                                 }
2277                         }
2278                 }
2279                 *++urlp = *tptr;
2280                 if (*tptr == '\0')
2281                         break;
2282  next_char:
2283                 tptr++;
2284         }
2285
2286         /* If URL is a directory, add '/' */
2287         if (urlp[-1] != '/') {
2288                 if (is_directory(urlcopy + 1, /*followlinks:*/ 1)) {
2289                         found_moved_temporarily = urlcopy;
2290                 }
2291         }
2292
2293         /* Log it */
2294         if (verbose > 1)
2295                 bb_error_msg("url:%s", urlcopy);
2296
2297         tptr = urlcopy;
2298         while ((tptr = strchr(tptr + 1, '/')) != NULL) {
2299                 /* have path1/path2 */
2300                 *tptr = '\0';
2301                 if (is_directory(urlcopy + 1, /*followlinks:*/ 1)) {
2302                         /* may have subdir config */
2303                         parse_conf(urlcopy + 1, SUBDIR_PARSE);
2304                         if_ip_denied_send_HTTP_FORBIDDEN_and_exit(remote_ip);
2305                 }
2306                 *tptr = '/';
2307         }
2308
2309         tptr = urlcopy + 1;      /* skip first '/' */
2310
2311 #if ENABLE_FEATURE_HTTPD_CGI
2312         if (is_prefixed_with(tptr, "cgi-bin/")) {
2313                 if (tptr[8] == '\0') {
2314                         /* protect listing "cgi-bin/" */
2315                         send_headers_and_exit(HTTP_FORBIDDEN);
2316                 }
2317                 cgi_type = CGI_NORMAL;
2318         }
2319 #endif
2320
2321         if (urlp[-1] == '/') {
2322                 /* When index_page string is appended to <dir>/ URL, it overwrites
2323                  * the query string. If we fall back to call /cgi-bin/index.cgi,
2324                  * query string would be lost and not available to the CGI.
2325                  * Work around it by making a deep copy.
2326                  */
2327                 if (ENABLE_FEATURE_HTTPD_CGI)
2328                         g_query = xstrdup(g_query); /* ok for NULL too */
2329                 strcpy(urlp, index_page);
2330         }
2331         if (stat(tptr, &sb) == 0) {
2332 #if ENABLE_FEATURE_HTTPD_CONFIG_WITH_SCRIPT_INTERPR
2333                 char *suffix = strrchr(tptr, '.');
2334                 if (suffix) {
2335                         Htaccess *cur;
2336                         for (cur = script_i; cur; cur = cur->next) {
2337                                 if (strcmp(cur->before_colon + 1, suffix) == 0) {
2338                                         cgi_type = CGI_INTERPRETER;
2339                                         break;
2340                                 }
2341                         }
2342                 }
2343 #endif
2344                 if (!found_moved_temporarily) {
2345                         file_size = sb.st_size;
2346                         last_mod = sb.st_mtime;
2347                 }
2348         }
2349 #if ENABLE_FEATURE_HTTPD_CGI
2350         else if (urlp[-1] == '/') {
2351                 /* It's a dir URL and there is no index.html
2352                  * Try cgi-bin/index.cgi */
2353                 if (access("/cgi-bin/index.cgi"+1, X_OK) == 0) {
2354                         cgi_type = CGI_INDEX;
2355                 }
2356         }
2357 #endif
2358         urlp[0] = '\0';
2359
2360 #if ENABLE_FEATURE_HTTPD_CGI
2361         total_headers_len = 0;
2362 #endif
2363
2364         /* Read until blank line */
2365         while (1) {
2366                 unsigned iobuf_len = get_line();
2367                 if (!iobuf_len)
2368                         break; /* EOF or error or empty line */
2369 #if ENABLE_FEATURE_HTTPD_CGI
2370                 /* Prevent unlimited growth of HTTP_xyz envvars */
2371                 total_headers_len += iobuf_len;
2372                 if (total_headers_len >= MAX_HTTP_HEADERS_SIZE)
2373                         send_headers_and_exit(HTTP_ENTITY_TOO_LARGE);
2374 #endif
2375                 if (DEBUG)
2376                         bb_error_msg("header: '%s'", iobuf);
2377 #if ENABLE_FEATURE_HTTPD_CGI || ENABLE_FEATURE_HTTPD_PROXY
2378                 /* Try and do our best to parse more lines */
2379                 if (STRNCASECMP(iobuf, "Content-Length:") == 0) {
2380                         /* extra read only for POST */
2381                         if (prequest != request_GET
2382 # if ENABLE_FEATURE_HTTPD_CGI
2383                          && prequest != request_HEAD
2384 # endif
2385                         ) {
2386                                 tptr = skip_whitespace(iobuf + sizeof("Content-Length:") - 1);
2387                                 if (!tptr[0])
2388                                         send_headers_and_exit(HTTP_BAD_REQUEST);
2389                                 /* not using strtoul: it ignores leading minus! */
2390                                 length = bb_strtou(tptr, NULL, 10);
2391                                 /* length is "ulong", but we need to pass it to int later */
2392                                 if (errno || length > INT_MAX)
2393                                         send_headers_and_exit(HTTP_BAD_REQUEST);
2394                         }
2395                         continue;
2396                 }
2397 #endif
2398 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
2399                 if (STRNCASECMP(iobuf, "Authorization:") == 0) {
2400                         /* We only allow Basic credentials.
2401                          * It shows up as "Authorization: Basic <user>:<passwd>" where
2402                          * "<user>:<passwd>" is base64 encoded.
2403                          */
2404                         tptr = skip_whitespace(iobuf + sizeof("Authorization:")-1);
2405                         if (STRNCASECMP(tptr, "Basic") == 0) {
2406                                 tptr += sizeof("Basic")-1;
2407                                 /* decodeBase64() skips whitespace itself */
2408                                 decodeBase64(tptr);
2409                                 authorized = check_user_passwd(urlcopy, tptr);
2410                                 continue;
2411                         }
2412                 }
2413 #endif
2414 #if ENABLE_FEATURE_HTTPD_RANGES
2415                 if (STRNCASECMP(iobuf, "Range:") == 0) {
2416                         /* We know only bytes=NNN-[MMM] */
2417                         char *s = skip_whitespace(iobuf + sizeof("Range:")-1);
2418                         if (is_prefixed_with(s, "bytes=")) {
2419                                 s += sizeof("bytes=")-1;
2420                                 range_start = BB_STRTOOFF(s, &s, 10);
2421                                 if (s[0] != '-' || range_start < 0) {
2422                                         range_start = -1;
2423                                 } else if (s[1]) {
2424                                         range_end = BB_STRTOOFF(s+1, NULL, 10);
2425                                         if (errno || range_end < range_start)
2426                                                 range_start = -1;
2427                                 }
2428                         }
2429                         continue;
2430                 }
2431 #endif
2432 #if ENABLE_FEATURE_HTTPD_GZIP
2433                 if (STRNCASECMP(iobuf, "Accept-Encoding:") == 0) {
2434                         /* Note: we do not support "gzip;q=0"
2435                          * method of _disabling_ gzip
2436                          * delivery. No one uses that, though */
2437                         const char *s = strstr(iobuf, "gzip");
2438                         if (s) {
2439                                 // want more thorough checks?
2440                                 //if (s[-1] == ' '
2441                                 // || s[-1] == ','
2442                                 // || s[-1] == ':'
2443                                 //) {
2444                                         content_gzip = 1;
2445                                 //}
2446                         }
2447                         continue;
2448                 }
2449 #endif
2450 #if ENABLE_FEATURE_HTTPD_CGI
2451                 if (cgi_type != CGI_NONE) {
2452                         bool ct = (STRNCASECMP(iobuf, "Content-Type:") == 0);
2453                         char *cp;
2454                         char *colon = strchr(iobuf, ':');
2455
2456                         if (!colon)
2457                                 continue;
2458                         cp = iobuf;
2459                         while (cp < colon) {
2460                                 /* a-z => A-Z, not-alnum => _ */
2461                                 char c = (*cp & ~0x20); /* toupper for A-Za-z, undef for others */
2462                                 if ((unsigned)(c - 'A') <= ('Z' - 'A')) {
2463                                         *cp++ = c;
2464                                         continue;
2465                                 }
2466                                 if (!isdigit(*cp))
2467                                         *cp = '_';
2468                                 cp++;
2469                         }
2470                         /* "Content-Type:" gets no HTTP_ prefix, all others do */
2471                         cp = xasprintf(ct ? "HTTP_%.*s=%s" + 5 : "HTTP_%.*s=%s",
2472                                 (int)(colon - iobuf), iobuf,
2473                                 skip_whitespace(colon + 1)
2474                         );
2475                         putenv(cp);
2476                 }
2477 #endif
2478         } /* while extra header reading */
2479
2480         /* We are done reading headers, disable peer timeout */
2481         alarm(0);
2482
2483         if (strcmp(bb_basename(urlcopy), HTTPD_CONF) == 0) {
2484                 /* protect listing [/path]/httpd.conf or IP deny */
2485                 send_headers_and_exit(HTTP_FORBIDDEN);
2486         }
2487
2488 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
2489         /* Case: no "Authorization:" was seen, but page might require passwd.
2490          * Check that with dummy user:pass */
2491         if (authorized < 0)
2492                 authorized = check_user_passwd(urlcopy, (char *) "");
2493         if (!authorized)
2494                 send_headers_and_exit(HTTP_UNAUTHORIZED);
2495 #endif
2496
2497         if (found_moved_temporarily) {
2498                 send_headers_and_exit(HTTP_MOVED_TEMPORARILY);
2499         }
2500
2501         tptr = urlcopy + 1;      /* skip first '/' */
2502
2503 #if ENABLE_FEATURE_HTTPD_CGI
2504         if (cgi_type != CGI_NONE) {
2505                 send_cgi_and_exit(
2506                         (cgi_type == CGI_INDEX) ? "/cgi-bin/index.cgi"
2507                         /*CGI_NORMAL or CGI_INTERPRETER*/ : urlcopy,
2508                         urlcopy, prequest, length
2509                 );
2510         }
2511 #endif
2512
2513         if (urlp[-1] == '/') {
2514                 strcpy(urlp, index_page);
2515         }
2516
2517 #if ENABLE_FEATURE_HTTPD_CGI
2518         if (prequest != request_GET && prequest != request_HEAD) {
2519                 /* POST for files does not make sense */
2520                 send_headers_and_exit(HTTP_NOT_IMPLEMENTED);
2521         }
2522         send_file_and_exit(tptr,
2523                 (prequest != request_HEAD ? SEND_HEADERS_AND_BODY : SEND_HEADERS)
2524         );
2525 #else
2526         send_file_and_exit(tptr, SEND_HEADERS_AND_BODY);
2527 #endif
2528 }
2529
2530 /*
2531  * The main http server function.
2532  * Given a socket, listen for new connections and farm out
2533  * the processing as a [v]forked process.
2534  * Never returns.
2535  */
2536 #if BB_MMU
2537 static void mini_httpd(int server_socket) NORETURN;
2538 static void mini_httpd(int server_socket)
2539 {
2540         /* NB: it's best to not use xfuncs in this loop before fork().
2541          * Otherwise server may die on transient errors (temporary
2542          * out-of-memory condition, etc), which is Bad(tm).
2543          * Try to do any dangerous calls after fork.
2544          */
2545         while (1) {
2546                 int n;
2547                 len_and_sockaddr fromAddr;
2548
2549                 /* Wait for connections... */
2550                 fromAddr.len = LSA_SIZEOF_SA;
2551                 n = accept(server_socket, &fromAddr.u.sa, &fromAddr.len);
2552                 if (n < 0)
2553                         continue;
2554
2555                 /* set the KEEPALIVE option to cull dead connections */
2556                 setsockopt_keepalive(n);
2557
2558                 if (fork() == 0) {
2559                         /* child */
2560                         /* Do not reload config on HUP */
2561                         signal(SIGHUP, SIG_IGN);
2562                         close(server_socket);
2563                         xmove_fd(n, 0);
2564                         xdup2(0, 1);
2565
2566                         handle_incoming_and_exit(&fromAddr);
2567                 }
2568                 /* parent, or fork failed */
2569                 close(n);
2570         } /* while (1) */
2571         /* never reached */
2572 }
2573 #else
2574 static void mini_httpd_nommu(int server_socket, int argc, char **argv) NORETURN;
2575 static void mini_httpd_nommu(int server_socket, int argc, char **argv)
2576 {
2577         char *argv_copy[argc + 2];
2578
2579         argv_copy[0] = argv[0];
2580         argv_copy[1] = (char*)"-i";
2581         memcpy(&argv_copy[2], &argv[1], argc * sizeof(argv[0]));
2582
2583         /* NB: it's best to not use xfuncs in this loop before vfork().
2584          * Otherwise server may die on transient errors (temporary
2585          * out-of-memory condition, etc), which is Bad(tm).
2586          * Try to do any dangerous calls after fork.
2587          */
2588         while (1) {
2589                 int n;
2590
2591                 /* Wait for connections... */
2592                 n = accept(server_socket, NULL, NULL);
2593                 if (n < 0)
2594                         continue;
2595
2596                 /* set the KEEPALIVE option to cull dead connections */
2597                 setsockopt_keepalive(n);
2598
2599                 if (vfork() == 0) {
2600                         /* child */
2601                         /* Do not reload config on HUP */
2602                         signal(SIGHUP, SIG_IGN);
2603                         close(server_socket);
2604                         xmove_fd(n, 0);
2605                         xdup2(0, 1);
2606
2607                         /* Run a copy of ourself in inetd mode */
2608                         re_exec(argv_copy);
2609                 }
2610                 argv_copy[0][0] &= 0x7f;
2611                 /* parent, or vfork failed */
2612                 close(n);
2613         } /* while (1) */
2614         /* never reached */
2615 }
2616 #endif
2617
2618 /*
2619  * Process a HTTP connection on stdin/out.
2620  * Never returns.
2621  */
2622 static void mini_httpd_inetd(void) NORETURN;
2623 static void mini_httpd_inetd(void)
2624 {
2625         len_and_sockaddr fromAddr;
2626
2627         memset(&fromAddr, 0, sizeof(fromAddr));
2628         fromAddr.len = LSA_SIZEOF_SA;
2629         /* NB: can fail if user runs it by hand and types in http cmds */
2630         getpeername(0, &fromAddr.u.sa, &fromAddr.len);
2631         handle_incoming_and_exit(&fromAddr);
2632 }
2633
2634 static void sighup_handler(int sig UNUSED_PARAM)
2635 {
2636         int sv = errno;
2637         parse_conf(DEFAULT_PATH_HTTPD_CONF, SIGNALED_PARSE);
2638         errno = sv;
2639 }
2640
2641 enum {
2642         c_opt_config_file = 0,
2643         d_opt_decode_url,
2644         h_opt_home_httpd,
2645         IF_FEATURE_HTTPD_ENCODE_URL_STR(e_opt_encode_url,)
2646         IF_FEATURE_HTTPD_BASIC_AUTH(    r_opt_realm     ,)
2647         IF_FEATURE_HTTPD_AUTH_MD5(      m_opt_md5       ,)
2648         IF_FEATURE_HTTPD_SETUID(        u_opt_setuid    ,)
2649         p_opt_port      ,
2650         p_opt_inetd     ,
2651         p_opt_foreground,
2652         p_opt_verbose   ,
2653         OPT_CONFIG_FILE = 1 << c_opt_config_file,
2654         OPT_DECODE_URL  = 1 << d_opt_decode_url,
2655         OPT_HOME_HTTPD  = 1 << h_opt_home_httpd,
2656         OPT_ENCODE_URL  = IF_FEATURE_HTTPD_ENCODE_URL_STR((1 << e_opt_encode_url)) + 0,
2657         OPT_REALM       = IF_FEATURE_HTTPD_BASIC_AUTH(    (1 << r_opt_realm     )) + 0,
2658         OPT_MD5         = IF_FEATURE_HTTPD_AUTH_MD5(      (1 << m_opt_md5       )) + 0,
2659         OPT_SETUID      = IF_FEATURE_HTTPD_SETUID(        (1 << u_opt_setuid    )) + 0,
2660         OPT_PORT        = 1 << p_opt_port,
2661         OPT_INETD       = 1 << p_opt_inetd,
2662         OPT_FOREGROUND  = 1 << p_opt_foreground,
2663         OPT_VERBOSE     = 1 << p_opt_verbose,
2664 };
2665
2666
2667 int httpd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
2668 int httpd_main(int argc UNUSED_PARAM, char **argv)
2669 {
2670         int server_socket = server_socket; /* for gcc */
2671         unsigned opt;
2672         char *url_for_decode;
2673         IF_FEATURE_HTTPD_ENCODE_URL_STR(const char *url_for_encode;)
2674         IF_FEATURE_HTTPD_SETUID(const char *s_ugid = NULL;)
2675         IF_FEATURE_HTTPD_SETUID(struct bb_uidgid_t ugid;)
2676         IF_FEATURE_HTTPD_AUTH_MD5(const char *pass;)
2677
2678         INIT_G();
2679
2680 #if ENABLE_LOCALE_SUPPORT
2681         /* Undo busybox.c: we want to speak English in http (dates etc) */
2682         setlocale(LC_TIME, "C");
2683 #endif
2684
2685         home_httpd = xrealloc_getcwd_or_warn(NULL);
2686         /* We do not "absolutize" path given by -h (home) opt.
2687          * If user gives relative path in -h,
2688          * $SCRIPT_FILENAME will not be set. */
2689         opt = getopt32(argv, "^"
2690                         "c:d:h:"
2691                         IF_FEATURE_HTTPD_ENCODE_URL_STR("e:")
2692                         IF_FEATURE_HTTPD_BASIC_AUTH("r:")
2693                         IF_FEATURE_HTTPD_AUTH_MD5("m:")
2694                         IF_FEATURE_HTTPD_SETUID("u:")
2695                         "p:ifv"
2696                         "\0"
2697                         /* -v counts, -i implies -f */
2698                         "vv:if",
2699                         &opt_c_configFile, &url_for_decode, &home_httpd
2700                         IF_FEATURE_HTTPD_ENCODE_URL_STR(, &url_for_encode)
2701                         IF_FEATURE_HTTPD_BASIC_AUTH(, &g_realm)
2702                         IF_FEATURE_HTTPD_AUTH_MD5(, &pass)
2703                         IF_FEATURE_HTTPD_SETUID(, &s_ugid)
2704                         , &bind_addr_or_port
2705                         , &verbose
2706                 );
2707         if (opt & OPT_DECODE_URL) {
2708                 fputs(percent_decode_in_place(url_for_decode, /*strict:*/ 0), stdout);
2709                 return 0;
2710         }
2711 #if ENABLE_FEATURE_HTTPD_ENCODE_URL_STR
2712         if (opt & OPT_ENCODE_URL) {
2713                 fputs(encodeString(url_for_encode), stdout);
2714                 return 0;
2715         }
2716 #endif
2717 #if ENABLE_FEATURE_HTTPD_AUTH_MD5
2718         if (opt & OPT_MD5) {
2719                 char salt[sizeof("$1$XXXXXXXX")];
2720                 salt[0] = '$';
2721                 salt[1] = '1';
2722                 salt[2] = '$';
2723                 crypt_make_salt(salt + 3, 4);
2724                 puts(pw_encrypt(pass, salt, /*cleanup:*/ 0));
2725                 return 0;
2726         }
2727 #endif
2728 #if ENABLE_FEATURE_HTTPD_SETUID
2729         if (opt & OPT_SETUID) {
2730                 xget_uidgid(&ugid, s_ugid);
2731         }
2732 #endif
2733
2734 #if !BB_MMU
2735         if (!(opt & OPT_FOREGROUND)) {
2736                 bb_daemonize_or_rexec(0, argv); /* don't change current directory */
2737         }
2738 #endif
2739
2740         xchdir(home_httpd);
2741         if (!(opt & OPT_INETD)) {
2742                 signal(SIGCHLD, SIG_IGN);
2743                 server_socket = openServer();
2744 #if ENABLE_FEATURE_HTTPD_SETUID
2745                 /* drop privileges */
2746                 if (opt & OPT_SETUID) {
2747                         if (ugid.gid != (gid_t)-1) {
2748                                 if (setgroups(1, &ugid.gid) == -1)
2749                                         bb_simple_perror_msg_and_die("setgroups");
2750                                 xsetgid(ugid.gid);
2751                         }
2752                         xsetuid(ugid.uid);
2753                 }
2754 #endif
2755         }
2756
2757 #if 0
2758         /* User can do it himself: 'env - PATH="$PATH" httpd'
2759          * We don't do it because we don't want to screw users
2760          * which want to do
2761          * 'env - VAR1=val1 VAR2=val2 httpd'
2762          * and have VAR1 and VAR2 values visible in their CGIs.
2763          * Besides, it is also smaller. */
2764         {
2765                 char *p = getenv("PATH");
2766                 /* env strings themself are not freed, no need to xstrdup(p): */
2767                 clearenv();
2768                 if (p)
2769                         putenv(p - 5);
2770 //              if (!(opt & OPT_INETD))
2771 //                      setenv_long("SERVER_PORT", ???);
2772         }
2773 #endif
2774
2775         parse_conf(DEFAULT_PATH_HTTPD_CONF, FIRST_PARSE);
2776         if (!(opt & OPT_INETD))
2777                 signal(SIGHUP, sighup_handler);
2778
2779         xfunc_error_retval = 0;
2780         if (opt & OPT_INETD)
2781                 mini_httpd_inetd(); /* never returns */
2782 #if BB_MMU
2783         if (!(opt & OPT_FOREGROUND))
2784                 bb_daemonize(0); /* don't change current directory */
2785         mini_httpd(server_socket); /* never returns */
2786 #else
2787         mini_httpd_nommu(server_socket, argc, argv); /* never returns */
2788 #endif
2789         /* return 0; */
2790 }