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