networking/httpd.c

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