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_HTTPD_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 = 0,
 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         bind_addr_or_port = "80"; \
 374         index_page = index_html; \
 375         file_size = -1; \
 376 } while (0)
 377
 378
 379 #define STRNCASECMP(a, str) strncasecmp((a), (str), sizeof(str)-1)
 380
 381 /* Prototypes */
 382 enum {
 383         SEND_HEADERS     = (1 << 0),
 384         SEND_BODY        = (1 << 1),
 385         SEND_HEADERS_AND_BODY = SEND_HEADERS + SEND_BODY,
 386 };
 387 static void send_file_and_exit(const char *url, int what) NORETURN;
 388
 389 static void free_llist(has_next_ptr **pptr)
 390 {
 391         has_next_ptr *cur = *pptr;
 392         while (cur) {
 393                 has_next_ptr *t = cur;
 394                 cur = cur->next;
 395                 free(t);
 396         }
 397         *pptr = NULL;
 398 }
 399
 400 static ALWAYS_INLINE void free_Htaccess_list(Htaccess **pptr)
 401 {
 402         free_llist((has_next_ptr**)pptr);
 403 }
 404
 405 static ALWAYS_INLINE void free_Htaccess_IP_list(Htaccess_IP **pptr)
 406 {
 407         free_llist((has_next_ptr**)pptr);
 408 }
 409
 410 /* Returns presumed mask width in bits or < 0 on error.
 411  * Updates strp, stores IP at provided pointer */
 412 static int scan_ip(const char **strp, unsigned *ipp, unsigned char endc)
 413 {
 414         const char *p = *strp;
 415         int auto_mask = 8;
 416         unsigned ip = 0;
 417         int j;
 418
 419         if (*p == '/')
 420                 return -auto_mask;
 421
 422         for (j = 0; j < 4; j++) {
 423                 unsigned octet;
 424
 425                 if ((*p < '0' || *p > '9') && *p != '/' && *p)
 426                         return -auto_mask;
 427                 octet = 0;
 428                 while (*p >= '0' && *p <= '9') {
 429                         octet *= 10;
 430                         octet += *p - '0';
 431                         if (octet > 255)
 432                                 return -auto_mask;
 433                         p++;
 434                 }
 435                 if (*p == '.')
 436                         p++;
 437                 if (*p != '/' && *p)
 438                         auto_mask += 8;
 439                 ip = (ip << 8) | octet;
 440         }
 441         if (*p) {
 442                 if (*p != endc)
 443                         return -auto_mask;
 444                 p++;
 445                 if (*p == '\0')
 446                         return -auto_mask;
 447         }
 448         *ipp = ip;
 449         *strp = p;
 450         return auto_mask;
 451 }
 452
 453 /* Returns 0 on success. Stores IP and mask at provided pointers */
 454 static int scan_ip_mask(const char *str, unsigned *ipp, unsigned *maskp)
 455 {
 456         int i;
 457         unsigned mask;
 458         char *p;
 459
 460         i = scan_ip(&str, ipp, '/');
 461         if (i < 0)
 462                 return i;
 463
 464         if (*str) {
 465                 /* there is /xxx after dotted-IP address */
 466                 i = bb_strtou(str, &p, 10);
 467                 if (*p == '.') {
 468                         /* 'xxx' itself is dotted-IP mask, parse it */
 469                         /* (return 0 (success) only if it has N.N.N.N form) */
 470                         return scan_ip(&str, maskp, '\0') - 32;
 471                 }
 472                 if (*p)
 473                         return -1;
 474         }
 475
 476         if (i > 32)
 477                 return -1;
 478
 479         if (sizeof(unsigned) == 4 && i == 32) {
 480                 /* mask >>= 32 below may not work */
 481                 mask = 0;
 482         } else {
 483                 mask = 0xffffffff;
 484                 mask >>= i;
 485         }
 486         /* i == 0 -> *maskp = 0x00000000
 487          * i == 1 -> *maskp = 0x80000000
 488          * i == 4 -> *maskp = 0xf0000000
 489          * i == 31 -> *maskp = 0xfffffffe
 490          * i == 32 -> *maskp = 0xffffffff */
 491         *maskp = (uint32_t)(~mask);
 492         return 0;
 493 }
 494
 495 /*
 496  * Parse configuration file into in-memory linked list.
 497  *
 498  * Any previous IP rules are discarded.
 499  * If the flag argument is not SUBDIR_PARSE then all /path and mime rules
 500  * are also discarded.  That is, previous settings are retained if flag is
 501  * SUBDIR_PARSE.
 502  * Error pages are only parsed on the main config file.
 503  *
 504  * path   Path where to look for httpd.conf (without filename).
 505  * flag   Type of the parse request.
 506  */
 507 /* flag param: */
 508 enum {
 509         FIRST_PARSE    = 0, /* path will be "/etc" */
 510         SIGNALED_PARSE = 1, /* path will be "/etc" */
 511         SUBDIR_PARSE   = 2, /* path will be derived from URL */
 512 };
 513 static void parse_conf(const char *path, int flag)
 514 {
 515         /* internally used extra flag state */
 516         enum { TRY_CURDIR_PARSE = 3 };
 517
 518         FILE *f;
 519         const char *filename;
 520         char buf[160];
 521
 522         /* discard old rules */
 523         free_Htaccess_IP_list(&ip_a_d);
 524         flg_deny_all = 0;
 525         /* retain previous auth and mime config only for subdir parse */
 526         if (flag != SUBDIR_PARSE) {
 527                 free_Htaccess_list(&mime_a);
 528 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
 529                 free_Htaccess_list(&g_auth);
 530 #endif
 531 #if ENABLE_FEATURE_HTTPD_CONFIG_WITH_SCRIPT_INTERPR
 532                 free_Htaccess_list(&script_i);
 533 #endif
 534         }
 535
 536         filename = opt_c_configFile;
 537         if (flag == SUBDIR_PARSE || filename == NULL) {
 538                 filename = alloca(strlen(path) + sizeof(HTTPD_CONF) + 2);
 539                 sprintf((char *)filename, "%s/%s", path, HTTPD_CONF);
 540         }
 541
 542         while ((f = fopen_for_read(filename)) == NULL) {
 543                 if (flag >= SUBDIR_PARSE) { /* SUBDIR or TRY_CURDIR */
 544                         /* config file not found, no changes to config */
 545                         return;
 546                 }
 547                 if (flag == FIRST_PARSE) {
 548                         /* -c CONFFILE given, but CONFFILE doesn't exist? */
 549                         if (opt_c_configFile)
 550                                 bb_simple_perror_msg_and_die(opt_c_configFile);
 551                         /* else: no -c, thus we looked at /etc/httpd.conf,
 552                          * and it's not there. try ./httpd.conf: */
 553                 }
 554                 flag = TRY_CURDIR_PARSE;
 555                 filename = HTTPD_CONF;
 556         }
 557
 558 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
 559         /* in "/file:user:pass" lines, we prepend path in subdirs */
 560         if (flag != SUBDIR_PARSE)
 561                 path = "";
 562 #endif
 563         /* The lines can be:
 564          *
 565          * I:default_index_file
 566          * H:http_home
 567          * [AD]:IP[/mask]   # allow/deny, * for wildcard
 568          * Ennn:error.html  # error page for status nnn
 569          * P:/url:[http://]hostname[:port]/new/path # reverse proxy
 570          * .ext:mime/type   # mime type
 571          * *.php:/path/php  # run xxx.php through an interpreter
 572          * /file:user:pass  # username and password
 573          */
 574         while (fgets(buf, sizeof(buf), f) != NULL) {
 575                 unsigned strlen_buf;
 576                 unsigned char ch;
 577                 char *after_colon;
 578
 579                 { /* remove all whitespace, and # comments */
 580                         char *p, *p0;
 581
 582                         p0 = buf;
 583                         /* skip non-whitespace beginning. Often the whole line
 584                          * is non-whitespace. We want this case to work fast,
 585                          * without needless copying, therefore we don't merge
 586                          * this operation into next while loop. */
 587                         while ((ch = *p0) != '\0' && ch != '\n' && ch != '#'
 588                          && ch != ' ' && ch != '\t'
 589                         ) {
 590                                 p0++;
 591                         }
 592                         p = p0;
 593                         /* if we enter this loop, we have some whitespace.
 594                          * discard it */
 595                         while (ch != '\0' && ch != '\n' && ch != '#') {
 596                                 if (ch != ' ' && ch != '\t') {
 597                                         *p++ = ch;
 598                                 }
 599                                 ch = *++p0;
 600                         }
 601                         *p = '\0';
 602                         strlen_buf = p - buf;
 603                         if (strlen_buf == 0)
 604                                 continue; /* empty line */
 605                 }
 606
 607                 after_colon = strchr(buf, ':');
 608                 /* strange line? */
 609                 if (after_colon == NULL || *++after_colon == '\0')
 610                         goto config_error;
 611
 612                 ch = (buf[0] & ~0x20); /* toupper if it's a letter */
 613
 614                 if (ch == 'I') {
 615                         if (index_page != index_html)
 616                                 free((char*)index_page);
 617                         index_page = xstrdup(after_colon);
 618                         continue;
 619                 }
 620
 621                 /* do not allow jumping around using H in subdir's configs */
 622                 if (flag == FIRST_PARSE && ch == 'H') {
 623                         home_httpd = xstrdup(after_colon);
 624                         xchdir(home_httpd);
 625                         continue;
 626                 }
 627
 628                 if (ch == 'A' || ch == 'D') {
 629                         Htaccess_IP *pip;
 630
 631                         if (*after_colon == '*') {
 632                                 if (ch == 'D') {
 633                                         /* memorize "deny all" */
 634                                         flg_deny_all = 1;
 635                                 }
 636                                 /* skip assumed "A:*", it is a default anyway */
 637                                 continue;
 638                         }
 639                         /* store "allow/deny IP/mask" line */
 640                         pip = xzalloc(sizeof(*pip));
 641                         if (scan_ip_mask(after_colon, &pip->ip, &pip->mask)) {
 642                                 /* IP{/mask} syntax error detected, protect all */
 643                                 ch = 'D';
 644                                 pip->mask = 0;
 645                         }
 646                         pip->allow_deny = ch;
 647                         if (ch == 'D') {
 648                                 /* Deny:from_IP - prepend */
 649                                 pip->next = ip_a_d;
 650                                 ip_a_d = pip;
 651                         } else {
 652                                 /* A:from_IP - append (thus all D's precedes A's) */
 653                                 Htaccess_IP *prev_IP = ip_a_d;
 654                                 if (prev_IP == NULL) {
 655                                         ip_a_d = pip;
 656                                 } else {
 657                                         while (prev_IP->next)
 658                                                 prev_IP = prev_IP->next;
 659                                         prev_IP->next = pip;
 660                                 }
 661                         }
 662                         continue;
 663                 }
 664
 665 #if ENABLE_FEATURE_HTTPD_ERROR_PAGES
 666                 if (flag == FIRST_PARSE && ch == 'E') {
 667                         unsigned i;
 668                         int status = atoi(buf + 1); /* error status code */
 669
 670                         if (status < HTTP_CONTINUE) {
 671                                 goto config_error;
 672                         }
 673                         /* then error page; find matching status */
 674                         for (i = 0; i < ARRAY_SIZE(http_response_type); i++) {
 675                                 if (http_response_type[i] == status) {
 676                                         /* We chdir to home_httpd, thus no need to
 677                                          * concat_path_file(home_httpd, after_colon)
 678                                          * here */
 679                                         http_error_page[i] = xstrdup(after_colon);
 680                                         break;
 681                                 }
 682                         }
 683                         continue;
 684                 }
 685 #endif
 686
 687 #if ENABLE_FEATURE_HTTPD_PROXY
 688                 if (flag == FIRST_PARSE && ch == 'P') {
 689                         /* P:/url:[http://]hostname[:port]/new/path */
 690                         char *url_from, *host_port, *url_to;
 691                         Htaccess_Proxy *proxy_entry;
 692
 693                         url_from = after_colon;
 694                         host_port = strchr(after_colon, ':');
 695                         if (host_port == NULL) {
 696                                 goto config_error;
 697                         }
 698                         *host_port++ = '\0';
 699                         if (strncmp(host_port, "http://", 7) == 0)
 700                                 host_port += 7;
 701                         if (*host_port == '\0') {
 702                                 goto config_error;
 703                         }
 704                         url_to = strchr(host_port, '/');
 705                         if (url_to == NULL) {
 706                                 goto config_error;
 707                         }
 708                         *url_to = '\0';
 709                         proxy_entry = xzalloc(sizeof(*proxy_entry));
 710                         proxy_entry->url_from = xstrdup(url_from);
 711                         proxy_entry->host_port = xstrdup(host_port);
 712                         *url_to = '/';
 713                         proxy_entry->url_to = xstrdup(url_to);
 714                         proxy_entry->next = proxy;
 715                         proxy = proxy_entry;
 716                         continue;
 717                 }
 718 #endif
 719                 /* the rest of directives are non-alphabetic,
 720                  * must avoid using "toupper'ed" ch */
 721                 ch = buf[0];
 722
 723                 if (ch == '.' /* ".ext:mime/type" */
 724 #if ENABLE_FEATURE_HTTPD_CONFIG_WITH_SCRIPT_INTERPR
 725                  || (ch == '*' && buf[1] == '.') /* "*.php:/path/php" */
 726 #endif
 727                 ) {
 728                         char *p;
 729                         Htaccess *cur;
 730
 731                         cur = xzalloc(sizeof(*cur) /* includes space for NUL */ + strlen_buf);
 732                         strcpy(cur->before_colon, buf);
 733                         p = cur->before_colon + (after_colon - buf);
 734                         p[-1] = '\0';
 735                         cur->after_colon = p;
 736                         if (ch == '.') {
 737                                 /* .mime line: prepend to mime_a list */
 738                                 cur->next = mime_a;
 739                                 mime_a = cur;
 740                         }
 741 #if ENABLE_FEATURE_HTTPD_CONFIG_WITH_SCRIPT_INTERPR
 742                         else {
 743                                 /* script interpreter line: prepend to script_i list */
 744                                 cur->next = script_i;
 745                                 script_i = cur;
 746                         }
 747 #endif
 748                         continue;
 749                 }
 750
 751 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
 752                 if (ch == '/') { /* "/file:user:pass" */
 753                         char *p;
 754                         Htaccess *cur;
 755                         unsigned file_len;
 756
 757                         /* note: path is "" unless we are in SUBDIR parse,
 758                          * otherwise it does NOT start with "/" */
 759                         cur = xzalloc(sizeof(*cur) /* includes space for NUL */
 760                                 + 1 + strlen(path)
 761                                 + strlen_buf
 762                                 );
 763                         /* form "/path/file" */
 764                         sprintf(cur->before_colon, "/%s%.*s",
 765                                 path,
 766                                 (int) (after_colon - buf - 1), /* includes "/", but not ":" */
 767                                 buf);
 768                         /* canonicalize it */
 769                         p = bb_simplify_abs_path_inplace(cur->before_colon);
 770                         file_len = p - cur->before_colon;
 771                         /* add "user:pass" after NUL */
 772                         strcpy(++p, after_colon);
 773                         cur->after_colon = p;
 774
 775                         /* insert cur into g_auth */
 776                         /* g_auth is sorted by decreased filename length */
 777                         {
 778                                 Htaccess *auth, **authp;
 779
 780                                 authp = &g_auth;
 781                                 while ((auth = *authp) != NULL) {
 782                                         if (file_len >= strlen(auth->before_colon)) {
 783                                                 /* insert cur before auth */
 784                                                 cur->next = auth;
 785                                                 break;
 786                                         }
 787                                         authp = &auth->next;
 788                                 }
 789                                 *authp = cur;
 790                         }
 791                         continue;
 792                 }
 793 #endif /* BASIC_AUTH */
 794
 795                 /* the line is not recognized */
 796  config_error:
 797                 bb_error_msg("config error '%s' in '%s'", buf, filename);
 798          } /* while (fgets) */
 799
 800          fclose(f);
 801 }
 802
 803 #if ENABLE_FEATURE_HTTPD_ENCODE_URL_STR
 804 /*
 805  * Given a string, html-encode special characters.
 806  * This is used for the -e command line option to provide an easy way
 807  * for scripts to encode result data without confusing browsers.  The
 808  * returned string pointer is memory allocated by malloc().
 809  *
 810  * Returns a pointer to the encoded string (malloced).
 811  */
 812 static char *encodeString(const char *string)
 813 {
 814         /* take the simple route and encode everything */
 815         /* could possibly scan once to get length.     */
 816         int len = strlen(string);
 817         char *out = xmalloc(len * 6 + 1);
 818         char *p = out;
 819         char ch;
 820
 821         while ((ch = *string++) != '\0') {
 822                 /* very simple check for what to encode */
 823                 if (isalnum(ch))
 824                         *p++ = ch;
 825                 else
 826                         p += sprintf(p, "&#%d;", (unsigned char) ch);
 827         }
 828         *p = '\0';
 829         return out;
 830 }
 831 #endif
 832
 833 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
 834 /*
 835  * Decode a base64 data stream as per rfc1521.
 836  * Note that the rfc states that non base64 chars are to be ignored.
 837  * Since the decode always results in a shorter size than the input,
 838  * it is OK to pass the input arg as an output arg.
 839  * Parameter: a pointer to a base64 encoded string.
 840  * Decoded data is stored in-place.
 841  */
 842 static void decodeBase64(char *Data)
 843 {
 844         const unsigned char *in = (const unsigned char *)Data;
 845         /* The decoded size will be at most 3/4 the size of the encoded */
 846         unsigned ch = 0;
 847         int i = 0;
 848
 849         while (*in) {
 850                 int t = *in++;
 851
 852                 if (t >= '0' && t <= '9')
 853                         t = t - '0' + 52;
 854                 else if (t >= 'A' && t <= 'Z')
 855                         t = t - 'A';
 856                 else if (t >= 'a' && t <= 'z')
 857                         t = t - 'a' + 26;
 858                 else if (t == '+')
 859                         t = 62;
 860                 else if (t == '/')
 861                         t = 63;
 862                 else if (t == '=')
 863                         t = 0;
 864                 else
 865                         continue;
 866
 867                 ch = (ch << 6) | t;
 868                 i++;
 869                 if (i == 4) {
 870                         *Data++ = (char) (ch >> 16);
 871                         *Data++ = (char) (ch >> 8);
 872                         *Data++ = (char) ch;
 873                         i = 0;
 874                 }
 875         }
 876         *Data = '\0';
 877 }
 878 #endif
 879
 880 /*
 881  * Create a listen server socket on the designated port.
 882  */
 883 static int openServer(void)
 884 {
 885         unsigned n = bb_strtou(bind_addr_or_port, NULL, 10);
 886         if (!errno && n && n <= 0xffff)
 887                 n = create_and_bind_stream_or_die(NULL, n);
 888         else
 889                 n = create_and_bind_stream_or_die(bind_addr_or_port, 80);
 890         xlisten(n, 9);
 891         return n;
 892 }
 893
 894 /*
 895  * Log the connection closure and exit.
 896  */
 897 static void log_and_exit(void) NORETURN;
 898 static void log_and_exit(void)
 899 {
 900         /* Paranoia. IE said to be buggy. It may send some extra data
 901          * or be confused by us just exiting without SHUT_WR. Oh well. */
 902         shutdown(1, SHUT_WR);
 903         /* Why??
 904         (this also messes up stdin when user runs httpd -i from terminal)
 905         ndelay_on(0);
 906         while (read(STDIN_FILENO, iobuf, IOBUF_SIZE) > 0)
 907                 continue;
 908         */
 909
 910         if (verbose > 2)
 911                 bb_error_msg("closed");
 912         _exit(xfunc_error_retval);
 913 }
 914
 915 /*
 916  * Create and send HTTP response headers.
 917  * The arguments are combined and sent as one write operation.  Note that
 918  * IE will puke big-time if the headers are not sent in one packet and the
 919  * second packet is delayed for any reason.
 920  * responseNum - the result code to send.
 921  */
 922 static void send_headers(int responseNum)
 923 {
 924         static const char RFC1123FMT[] ALIGN1 = "%a, %d %b %Y %H:%M:%S GMT";
 925
 926         const char *responseString = "";
 927         const char *infoString = NULL;
 928         const char *mime_type;
 929 #if ENABLE_FEATURE_HTTPD_ERROR_PAGES
 930         const char *error_page = NULL;
 931 #endif
 932         unsigned i;
 933         time_t timer = time(NULL);
 934         char tmp_str[80];
 935         int len;
 936
 937         for (i = 0; i < ARRAY_SIZE(http_response_type); i++) {
 938                 if (http_response_type[i] == responseNum) {
 939                         responseString = http_response[i].name;
 940                         infoString = http_response[i].info;
 941 #if ENABLE_FEATURE_HTTPD_ERROR_PAGES
 942                         error_page = http_error_page[i];
 943 #endif
 944                         break;
 945                 }
 946         }
 947         /* error message is HTML */
 948         mime_type = responseNum == HTTP_OK ?
 949                                 found_mime_type : "text/html";
 950
 951         if (verbose)
 952                 bb_error_msg("response:%u", responseNum);
 953
 954         /* emit the current date */
 955         strftime(tmp_str, sizeof(tmp_str), RFC1123FMT, gmtime(&timer));
 956         len = sprintf(iobuf,
 957                         "HTTP/1.0 %d %s\r\nContent-type: %s\r\n"
 958                         "Date: %s\r\nConnection: close\r\n",
 959                         responseNum, responseString, mime_type, tmp_str);
 960
 961 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
 962         if (responseNum == HTTP_UNAUTHORIZED) {
 963                 len += sprintf(iobuf + len,
 964                                 "WWW-Authenticate: Basic realm=\"%s\"\r\n",
 965                                 g_realm);
 966         }
 967 #endif
 968         if (responseNum == HTTP_MOVED_TEMPORARILY) {
 969                 len += sprintf(iobuf + len, "Location: %s/%s%s\r\n",
 970                                 found_moved_temporarily,
 971                                 (g_query ? "?" : ""),
 972                                 (g_query ? g_query : ""));
 973         }
 974
 975 #if ENABLE_FEATURE_HTTPD_ERROR_PAGES
 976         if (error_page && access(error_page, R_OK) == 0) {
 977                 strcat(iobuf, "\r\n");
 978                 len += 2;
 979
 980                 if (DEBUG)
 981                         fprintf(stderr, "headers: '%s'\n", iobuf);
 982                 full_write(STDOUT_FILENO, iobuf, len);
 983                 if (DEBUG)
 984                         fprintf(stderr, "writing error page: '%s'\n", error_page);
 985                 return send_file_and_exit(error_page, SEND_BODY);
 986         }
 987 #endif
 988
 989         if (file_size != -1) {    /* file */
 990                 strftime(tmp_str, sizeof(tmp_str), RFC1123FMT, gmtime(&last_mod));
 991 #if ENABLE_FEATURE_HTTPD_RANGES
 992                 if (responseNum == HTTP_PARTIAL_CONTENT) {
 993                         len += sprintf(iobuf + len, "Content-Range: bytes %"OFF_FMT"u-%"OFF_FMT"u/%"OFF_FMT"u\r\n",
 994                                         range_start,
 995                                         range_end,
 996                                         file_size);
 997                         file_size = range_end - range_start + 1;
 998                 }
 999 #endif
1000                 len += sprintf(iobuf + len,
1001 #if ENABLE_FEATURE_HTTPD_RANGES
1002                         "Accept-Ranges: bytes\r\n"
1003 #endif
1004                         "Last-Modified: %s\r\n%s %"OFF_FMT"u\r\n",
1005                                 tmp_str,
1006                                 content_gzip ? "Transfer-length:" : "Content-length:",
1007                                 file_size
1008                 );
1009         }
1010
1011         if (content_gzip)
1012                 len += sprintf(iobuf + len, "Content-Encoding: gzip\r\n");
1013
1014         iobuf[len++] = '\r';
1015         iobuf[len++] = '\n';
1016         if (infoString) {
1017                 len += sprintf(iobuf + len,
1018                                 "<HTML><HEAD><TITLE>%d %s</TITLE></HEAD>\n"
1019                                 "<BODY><H1>%d %s</H1>\n%s\n</BODY></HTML>\n",
1020                                 responseNum, responseString,
1021                                 responseNum, responseString, infoString);
1022         }
1023         if (DEBUG)
1024                 fprintf(stderr, "headers: '%s'\n", iobuf);
1025         if (full_write(STDOUT_FILENO, iobuf, len) != len) {
1026                 if (verbose > 1)
1027                         bb_perror_msg("error");
1028                 log_and_exit();
1029         }
1030 }
1031
1032 static void send_headers_and_exit(int responseNum) NORETURN;
1033 static void send_headers_and_exit(int responseNum)
1034 {
1035         IF_FEATURE_HTTPD_GZIP(content_gzip = 0;)
1036         send_headers(responseNum);
1037         log_and_exit();
1038 }
1039
1040 /*
1041  * Read from the socket until '\n' or EOF. '\r' chars are removed.
1042  * '\n' is replaced with NUL.
1043  * Return number of characters read or 0 if nothing is read
1044  * ('\r' and '\n' are not counted).
1045  * Data is returned in iobuf.
1046  */
1047 static int get_line(void)
1048 {
1049         int count = 0;
1050         char c;
1051
1052         alarm(HEADER_READ_TIMEOUT);
1053         while (1) {
1054                 if (hdr_cnt <= 0) {
1055                         hdr_cnt = safe_read(STDIN_FILENO, hdr_buf, sizeof(hdr_buf));
1056                         if (hdr_cnt <= 0)
1057                                 break;
1058                         hdr_ptr = hdr_buf;
1059                 }
1060                 iobuf[count] = c = *hdr_ptr++;
1061                 hdr_cnt--;
1062
1063                 if (c == '\r')
1064                         continue;
1065                 if (c == '\n') {
1066                         iobuf[count] = '\0';
1067                         break;
1068                 }
1069                 if (count < (IOBUF_SIZE - 1))      /* check overflow */
1070                         count++;
1071         }
1072         return count;
1073 }
1074
1075 #if ENABLE_FEATURE_HTTPD_CGI || ENABLE_FEATURE_HTTPD_PROXY
1076
1077 /* gcc 4.2.1 fares better with NOINLINE */
1078 static NOINLINE void cgi_io_loop_and_exit(int fromCgi_rd, int toCgi_wr, int post_len) NORETURN;
1079 static NOINLINE void cgi_io_loop_and_exit(int fromCgi_rd, int toCgi_wr, int post_len)
1080 {
1081         enum { FROM_CGI = 1, TO_CGI = 2 }; /* indexes in pfd[] */
1082         struct pollfd pfd[3];
1083         int out_cnt; /* we buffer a bit of initial CGI output */
1084         int count;
1085
1086         /* iobuf is used for CGI -> network data,
1087          * hdr_buf is for network -> CGI data (POSTDATA) */
1088
1089         /* If CGI dies, we still want to correctly finish reading its output
1090          * and send it to the peer. So please no SIGPIPEs! */
1091         signal(SIGPIPE, SIG_IGN);
1092
1093         // We inconsistently handle a case when more POSTDATA from network
1094         // is coming than we expected. We may give *some part* of that
1095         // extra data to CGI.
1096
1097         //if (hdr_cnt > post_len) {
1098         //      /* We got more POSTDATA from network than we expected */
1099         //      hdr_cnt = post_len;
1100         //}
1101         post_len -= hdr_cnt;
1102         /* post_len - number of POST bytes not yet read from network */
1103
1104         /* NB: breaking out of this loop jumps to log_and_exit() */
1105         out_cnt = 0;
1106         while (1) {
1107                 memset(pfd, 0, sizeof(pfd));
1108
1109                 pfd[FROM_CGI].fd = fromCgi_rd;
1110                 pfd[FROM_CGI].events = POLLIN;
1111
1112                 if (toCgi_wr) {
1113                         pfd[TO_CGI].fd = toCgi_wr;
1114                         if (hdr_cnt > 0) {
1115                                 pfd[TO_CGI].events = POLLOUT;
1116                         } else if (post_len > 0) {
1117                                 pfd[0].events = POLLIN;
1118                         } else {
1119                                 /* post_len <= 0 && hdr_cnt <= 0:
1120                                  * no more POST data to CGI,
1121                                  * let CGI see EOF on CGI's stdin */
1122                                 if (toCgi_wr != fromCgi_rd)
1123                                         close(toCgi_wr);
1124                                 toCgi_wr = 0;
1125                         }
1126                 }
1127
1128                 /* Now wait on the set of sockets */
1129                 count = safe_poll(pfd, toCgi_wr ? TO_CGI+1 : FROM_CGI+1, -1);
1130                 if (count <= 0) {
1131 #if 0
1132                         if (safe_waitpid(pid, &status, WNOHANG) <= 0) {
1133                                 /* Weird. CGI didn't exit and no fd's
1134                                  * are ready, yet poll returned?! */
1135                                 continue;
1136                         }
1137                         if (DEBUG && WIFEXITED(status))
1138                                 bb_error_msg("CGI exited, status=%d", WEXITSTATUS(status));
1139                         if (DEBUG && WIFSIGNALED(status))
1140                                 bb_error_msg("CGI killed, signal=%d", WTERMSIG(status));
1141 #endif
1142                         break;
1143                 }
1144
1145                 if (pfd[TO_CGI].revents) {
1146                         /* hdr_cnt > 0 here due to the way pfd[TO_CGI].events set */
1147                         /* Have data from peer and can write to CGI */
1148                         count = safe_write(toCgi_wr, hdr_ptr, hdr_cnt);
1149                         /* Doesn't happen, we dont use nonblocking IO here
1150                          *if (count < 0 && errno == EAGAIN) {
1151                          *      ...
1152                          *} else */
1153                         if (count > 0) {
1154                                 hdr_ptr += count;
1155                                 hdr_cnt -= count;
1156                         } else {
1157                                 /* EOF/broken pipe to CGI, stop piping POST data */
1158                                 hdr_cnt = post_len = 0;
1159                         }
1160                 }
1161
1162                 if (pfd[0].revents) {
1163                         /* post_len > 0 && hdr_cnt == 0 here */
1164                         /* We expect data, prev data portion is eaten by CGI
1165                          * and there *is* data to read from the peer
1166                          * (POSTDATA) */
1167                         //count = post_len > (int)sizeof(hdr_buf) ? (int)sizeof(hdr_buf) : post_len;
1168                         //count = safe_read(STDIN_FILENO, hdr_buf, count);
1169                         count = safe_read(STDIN_FILENO, hdr_buf, sizeof(hdr_buf));
1170                         if (count > 0) {
1171                                 hdr_cnt = count;
1172                                 hdr_ptr = hdr_buf;
1173                                 post_len -= count;
1174                         } else {
1175                                 /* no more POST data can be read */
1176                                 post_len = 0;
1177                         }
1178                 }
1179
1180                 if (pfd[FROM_CGI].revents) {
1181                         /* There is something to read from CGI */
1182                         char *rbuf = iobuf;
1183
1184                         /* Are we still buffering CGI output? */
1185                         if (out_cnt >= 0) {
1186                                 /* HTTP_200[] has single "\r\n" at the end.
1187                                  * According to http://hoohoo.ncsa.uiuc.edu/cgi/out.html,
1188                                  * CGI scripts MUST send their own header terminated by
1189                                  * empty line, then data. That's why we have only one
1190                                  * <cr><lf> pair here. We will output "200 OK" line
1191                                  * if needed, but CGI still has to provide blank line
1192                                  * between header and body */
1193
1194                                 /* Must use safe_read, not full_read, because
1195                                  * CGI may output a few first bytes and then wait
1196                                  * for POSTDATA without closing stdout.
1197                                  * With full_read we may wait here forever. */
1198                                 count = safe_read(fromCgi_rd, rbuf + out_cnt, PIPE_BUF - 8);
1199                                 if (count <= 0) {
1200                                         /* eof (or error) and there was no "HTTP",
1201                                          * so write it, then write received data */
1202                                         if (out_cnt) {
1203                                                 full_write(STDOUT_FILENO, HTTP_200, sizeof(HTTP_200)-1);
1204                                                 full_write(STDOUT_FILENO, rbuf, out_cnt);
1205                                         }
1206                                         break; /* CGI stdout is closed, exiting */
1207                                 }
1208                                 out_cnt += count;
1209                                 count = 0;
1210                                 /* "Status" header format is: "Status: 302 Redirected\r\n" */
1211                                 if (out_cnt >= 8 && memcmp(rbuf, "Status: ", 8) == 0) {
1212                                         /* send "HTTP/1.0 " */
1213                                         if (full_write(STDOUT_FILENO, HTTP_200, 9) != 9)
1214                                                 break;
1215                                         rbuf += 8; /* skip "Status: " */
1216                                         count = out_cnt - 8;
1217                                         out_cnt = -1; /* buffering off */
1218                                 } else if (out_cnt >= 4) {
1219                                         /* Did CGI add "HTTP"? */
1220                                         if (memcmp(rbuf, HTTP_200, 4) != 0) {
1221                                                 /* there is no "HTTP", do it ourself */
1222                                                 if (full_write(STDOUT_FILENO, HTTP_200, sizeof(HTTP_200)-1) != sizeof(HTTP_200)-1)
1223                                                         break;
1224                                         }
1225                                         /* Commented out:
1226                                         if (!strstr(rbuf, "ontent-")) {
1227                                                 full_write(s, "Content-type: text/plain\r\n\r\n", 28);
1228                                         }
1229                                          * Counter-example of valid CGI without Content-type:
1230                                          * echo -en "HTTP/1.0 302 Found\r\n"
1231                                          * echo -en "Location: http://www.busybox.net\r\n"
1232                                          * echo -en "\r\n"
1233                                          */
1234                                         count = out_cnt;
1235                                         out_cnt = -1; /* buffering off */
1236                                 }
1237                         } else {
1238                                 count = safe_read(fromCgi_rd, rbuf, PIPE_BUF);
1239                                 if (count <= 0)
1240                                         break;  /* eof (or error) */
1241                         }
1242                         if (full_write(STDOUT_FILENO, rbuf, count) != count)
1243                                 break;
1244                         if (DEBUG)
1245                                 fprintf(stderr, "cgi read %d bytes: '%.*s'\n", count, count, rbuf);
1246                 } /* if (pfd[FROM_CGI].revents) */
1247         } /* while (1) */
1248         log_and_exit();
1249 }
1250 #endif
1251
1252 #if ENABLE_FEATURE_HTTPD_CGI
1253
1254 static void setenv1(const char *name, const char *value)
1255 {
1256         setenv(name, value ? value : "", 1);
1257 }
1258
1259 /*
1260  * Spawn CGI script, forward CGI's stdin/out <=> network
1261  *
1262  * Environment variables are set up and the script is invoked with pipes
1263  * for stdin/stdout.  If a POST is being done the script is fed the POST
1264  * data in addition to setting the QUERY_STRING variable (for GETs or POSTs).
1265  *
1266  * Parameters:
1267  * const char *url              The requested URL (with leading /).
1268  * int post_len                 Length of the POST body.
1269  * const char *cookie           For set HTTP_COOKIE.
1270  * const char *content_type     For set CONTENT_TYPE.
1271  */
1272 static void send_cgi_and_exit(
1273                 const char *url,
1274                 const char *request,
1275                 int post_len,
1276                 const char *cookie,
1277                 const char *content_type) NORETURN;
1278 static void send_cgi_and_exit(
1279                 const char *url,
1280                 const char *request,
1281                 int post_len,
1282                 const char *cookie,
1283                 const char *content_type)
1284 {
1285         struct fd_pair fromCgi;  /* CGI -> httpd pipe */
1286         struct fd_pair toCgi;    /* httpd -> CGI pipe */
1287         char *script, *last_slash;
1288         int pid;
1289
1290         /* Make a copy. NB: caller guarantees:
1291          * url[0] == '/', url[1] != '/' */
1292         url = xstrdup(url);
1293
1294         /*
1295          * We are mucking with environment _first_ and then vfork/exec,
1296          * this allows us to use vfork safely. Parent doesn't care about
1297          * these environment changes anyway.
1298          */
1299
1300         /* Check for [dirs/]script.cgi/PATH_INFO */
1301         last_slash = script = (char*)url;
1302         while ((script = strchr(script + 1, '/')) != NULL) {
1303                 int dir;
1304                 *script = '\0';
1305                 dir = is_directory(url + 1, /*followlinks:*/ 1, NULL);
1306                 *script = '/';
1307                 if (!dir) {
1308                         /* not directory, found script.cgi/PATH_INFO */
1309                         break;
1310                 }
1311                 /* is directory, find next '/' */
1312                 last_slash = script;
1313         }
1314         setenv1("PATH_INFO", script);   /* set to /PATH_INFO or "" */
1315         setenv1("REQUEST_METHOD", request);
1316         if (g_query) {
1317                 putenv(xasprintf("%s=%s?%s", "REQUEST_URI", url, g_query));
1318         } else {
1319                 setenv1("REQUEST_URI", url);
1320         }
1321         if (script != NULL)
1322                 *script = '\0';         /* cut off /PATH_INFO */
1323
1324         /* SCRIPT_FILENAME is required by PHP in CGI mode */
1325         if (home_httpd[0] == '/') {
1326                 char *fullpath = concat_path_file(home_httpd, url);
1327                 setenv1("SCRIPT_FILENAME", fullpath);
1328         }
1329         /* set SCRIPT_NAME as full path: /cgi-bin/dirs/script.cgi */
1330         setenv1("SCRIPT_NAME", url);
1331         /* http://hoohoo.ncsa.uiuc.edu/cgi/env.html:
1332          * QUERY_STRING: The information which follows the ? in the URL
1333          * which referenced this script. This is the query information.
1334          * It should not be decoded in any fashion. This variable
1335          * should always be set when there is query information,
1336          * regardless of command line decoding. */
1337         /* (Older versions of bbox seem to do some decoding) */
1338         setenv1("QUERY_STRING", g_query);
1339         putenv((char*)"SERVER_SOFTWARE=busybox httpd/"BB_VER);
1340         putenv((char*)"SERVER_PROTOCOL=HTTP/1.0");
1341         putenv((char*)"GATEWAY_INTERFACE=CGI/1.1");
1342         /* Having _separate_ variables for IP and port defeats
1343          * the purpose of having socket abstraction. Which "port"
1344          * are you using on Unix domain socket?
1345          * IOW - REMOTE_PEER="1.2.3.4:56" makes much more sense.
1346          * Oh well... */
1347         {
1348                 char *p = rmt_ip_str ? rmt_ip_str : (char*)"";
1349                 char *cp = strrchr(p, ':');
1350                 if (ENABLE_FEATURE_IPV6 && cp && strchr(cp, ']'))
1351                         cp = NULL;
1352                 if (cp) *cp = '\0'; /* delete :PORT */
1353                 setenv1("REMOTE_ADDR", p);
1354                 if (cp) {
1355                         *cp = ':';
1356 #if ENABLE_FEATURE_HTTPD_SET_REMOTE_PORT_TO_ENV
1357                         setenv1("REMOTE_PORT", cp + 1);
1358 #endif
1359                 }
1360         }
1361         setenv1("HTTP_USER_AGENT", user_agent);
1362         if (http_accept)
1363                 setenv1("HTTP_ACCEPT", http_accept);
1364         if (http_accept_language)
1365                 setenv1("HTTP_ACCEPT_LANGUAGE", http_accept_language);
1366         if (post_len)
1367                 putenv(xasprintf("CONTENT_LENGTH=%d", post_len));
1368         if (cookie)
1369                 setenv1("HTTP_COOKIE", cookie);
1370         if (content_type)
1371                 setenv1("CONTENT_TYPE", content_type);
1372 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
1373         if (remoteuser) {
1374                 setenv1("REMOTE_USER", remoteuser);
1375                 putenv((char*)"AUTH_TYPE=Basic");
1376         }
1377 #endif
1378         if (referer)
1379                 setenv1("HTTP_REFERER", referer);
1380         setenv1("HTTP_HOST", host); /* set to "" if NULL */
1381         /* setenv1("SERVER_NAME", safe_gethostname()); - don't do this,
1382          * just run "env SERVER_NAME=xyz httpd ..." instead */
1383
1384         xpiped_pair(fromCgi);
1385         xpiped_pair(toCgi);
1386
1387         pid = vfork();
1388         if (pid < 0) {
1389                 /* TODO: log perror? */
1390                 log_and_exit();
1391         }
1392
1393         if (pid == 0) {
1394                 /* Child process */
1395                 char *argv[3];
1396
1397                 xfunc_error_retval = 242;
1398
1399                 /* NB: close _first_, then move fds! */
1400                 close(toCgi.wr);
1401                 close(fromCgi.rd);
1402                 xmove_fd(toCgi.rd, 0);  /* replace stdin with the pipe */
1403                 xmove_fd(fromCgi.wr, 1);  /* replace stdout with the pipe */
1404                 /* User seeing stderr output can be a security problem.
1405                  * If CGI really wants that, it can always do dup itself. */
1406                 /* dup2(1, 2); */
1407
1408                 /* Chdiring to script's dir */
1409                 script = last_slash;
1410                 if (script != url) { /* paranoia */
1411                         *script = '\0';
1412                         if (chdir(url + 1) != 0) {
1413                                 bb_perror_msg("chdir(%s)", url + 1);
1414                                 goto error_execing_cgi;
1415                         }
1416                         // not needed: *script = '/';
1417                 }
1418                 script++;
1419
1420                 /* set argv[0] to name without path */
1421                 argv[0] = script;
1422                 argv[1] = NULL;
1423
1424 #if ENABLE_FEATURE_HTTPD_CONFIG_WITH_SCRIPT_INTERPR
1425                 {
1426                         char *suffix = strrchr(script, '.');
1427
1428                         if (suffix) {
1429                                 Htaccess *cur;
1430                                 for (cur = script_i; cur; cur = cur->next) {
1431                                         if (strcmp(cur->before_colon + 1, suffix) == 0) {
1432                                                 /* found interpreter name */
1433                                                 argv[0] = cur->after_colon;
1434                                                 argv[1] = script;
1435                                                 argv[2] = NULL;
1436                                                 break;
1437                                         }
1438                                 }
1439                         }
1440                 }
1441 #endif
1442                 /* restore default signal dispositions for CGI process */
1443                 bb_signals(0
1444                         | (1 << SIGCHLD)
1445                         | (1 << SIGPIPE)
1446                         | (1 << SIGHUP)
1447                         , SIG_DFL);
1448
1449                 /* _NOT_ execvp. We do not search PATH. argv[0] is a filename
1450                  * without any dir components and will only match a file
1451                  * in the current directory */
1452                 execv(argv[0], argv);
1453                 if (verbose)
1454                         bb_perror_msg("can't execute '%s'", argv[0]);
1455  error_execing_cgi:
1456                 /* send to stdout
1457                  * (we are CGI here, our stdout is pumped to the net) */
1458                 send_headers_and_exit(HTTP_NOT_FOUND);
1459         } /* end child */
1460
1461         /* Parent process */
1462
1463         /* Restore variables possibly changed by child */
1464         xfunc_error_retval = 0;
1465
1466         /* Pump data */
1467         close(fromCgi.wr);
1468         close(toCgi.rd);
1469         cgi_io_loop_and_exit(fromCgi.rd, toCgi.wr, post_len);
1470 }
1471
1472 #endif          /* FEATURE_HTTPD_CGI */
1473
1474 /*
1475  * Send a file response to a HTTP request, and exit
1476  *
1477  * Parameters:
1478  * const char *url  The requested URL (with leading /).
1479  * what             What to send (headers/body/both).
1480  */
1481 static NOINLINE void send_file_and_exit(const char *url, int what)
1482 {
1483         char *suffix;
1484         int fd;
1485         ssize_t count;
1486
1487         if (content_gzip) {
1488                 /* does <url>.gz exist? Then use it instead */
1489                 char *gzurl = xasprintf("%s.gz", url);
1490                 fd = open(gzurl, O_RDONLY);
1491                 free(gzurl);
1492                 if (fd != -1) {
1493                         struct stat sb;
1494                         fstat(fd, &sb);
1495                         file_size = sb.st_size;
1496                         last_mod = sb.st_mtime;
1497                 } else {
1498                         IF_FEATURE_HTTPD_GZIP(content_gzip = 0;)
1499                         fd = open(url, O_RDONLY);
1500                 }
1501         } else {
1502                 fd = open(url, O_RDONLY);
1503         }
1504         if (fd < 0) {
1505                 if (DEBUG)
1506                         bb_perror_msg("can't open '%s'", url);
1507                 /* Error pages are sent by using send_file_and_exit(SEND_BODY).
1508                  * IOW: it is unsafe to call send_headers_and_exit
1509                  * if what is SEND_BODY! Can recurse! */
1510                 if (what != SEND_BODY)
1511                         send_headers_and_exit(HTTP_NOT_FOUND);
1512                 log_and_exit();
1513         }
1514         /* If you want to know about EPIPE below
1515          * (happens if you abort downloads from local httpd): */
1516         signal(SIGPIPE, SIG_IGN);
1517
1518         /* If not found, default is "application/octet-stream" */
1519         found_mime_type = "application/octet-stream";
1520         suffix = strrchr(url, '.');
1521         if (suffix) {
1522                 static const char suffixTable[] ALIGN1 =
1523                         /* Shorter suffix must be first:
1524                          * ".html.htm" will fail for ".htm"
1525                          */
1526                         ".txt.h.c.cc.cpp\0" "text/plain\0"
1527                         /* .htm line must be after .h line */
1528                         ".htm.html\0" "text/html\0"
1529                         ".jpg.jpeg\0" "image/jpeg\0"
1530                         ".gif\0"      "image/gif\0"
1531                         ".png\0"      "image/png\0"
1532                         /* .css line must be after .c line */
1533                         ".css\0"      "text/css\0"
1534                         ".wav\0"      "audio/wav\0"
1535                         ".avi\0"      "video/x-msvideo\0"
1536                         ".qt.mov\0"   "video/quicktime\0"
1537                         ".mpe.mpeg\0" "video/mpeg\0"
1538                         ".mid.midi\0" "audio/midi\0"
1539                         ".mp3\0"      "audio/mpeg\0"
1540 #if 0  /* unpopular */
1541                         ".au\0"       "audio/basic\0"
1542                         ".pac\0"      "application/x-ns-proxy-autoconfig\0"
1543                         ".vrml.wrl\0" "model/vrml\0"
1544 #endif
1545                         /* compiler adds another "\0" here */
1546                 ;
1547                 Htaccess *cur;
1548
1549                 /* Examine built-in table */
1550                 const char *table = suffixTable;
1551                 const char *table_next;
1552                 for (; *table; table = table_next) {
1553                         const char *try_suffix;
1554                         const char *mime_type;
1555                         mime_type  = table + strlen(table) + 1;
1556                         table_next = mime_type + strlen(mime_type) + 1;
1557                         try_suffix = strstr(table, suffix);
1558                         if (!try_suffix)
1559                                 continue;
1560                         try_suffix += strlen(suffix);
1561                         if (*try_suffix == '\0' || *try_suffix == '.') {
1562                                 found_mime_type = mime_type;
1563                                 break;
1564                         }
1565                         /* Example: strstr(table, ".av") != NULL, but it
1566                          * does not match ".avi" after all and we end up here.
1567                          * The table is arranged so that in this case we know
1568                          * that it can't match anything in the following lines,
1569                          * and we stop the search: */
1570                         break;
1571                 }
1572                 /* ...then user's table */
1573                 for (cur = mime_a; cur; cur = cur->next) {
1574                         if (strcmp(cur->before_colon, suffix) == 0) {
1575                                 found_mime_type = cur->after_colon;
1576                                 break;
1577                         }
1578                 }
1579         }
1580
1581         if (DEBUG)
1582                 bb_error_msg("sending file '%s' content-type: %s",
1583                         url, found_mime_type);
1584
1585 #if ENABLE_FEATURE_HTTPD_RANGES
1586         if (what == SEND_BODY /* err pages and ranges don't mix */
1587          || content_gzip /* we are sending compressed page: can't do ranges */  ///why?
1588         ) {
1589                 range_start = 0;
1590         }
1591         range_len = MAXINT(off_t);
1592         if (range_start) {
1593                 if (!range_end) {
1594                         range_end = file_size - 1;
1595                 }
1596                 if (range_end < range_start
1597                  || lseek(fd, range_start, SEEK_SET) != range_start
1598                 ) {
1599                         lseek(fd, 0, SEEK_SET);
1600                         range_start = 0;
1601                 } else {
1602                         range_len = range_end - range_start + 1;
1603                         send_headers(HTTP_PARTIAL_CONTENT);
1604                         what = SEND_BODY;
1605                 }
1606         }
1607 #endif
1608         if (what & SEND_HEADERS)
1609                 send_headers(HTTP_OK);
1610 #if ENABLE_FEATURE_HTTPD_USE_SENDFILE
1611         {
1612                 off_t offset = range_start;
1613                 while (1) {
1614                         /* sz is rounded down to 64k */
1615                         ssize_t sz = MAXINT(ssize_t) - 0xffff;
1616                         IF_FEATURE_HTTPD_RANGES(if (sz > range_len) sz = range_len;)
1617                         count = sendfile(STDOUT_FILENO, fd, &offset, sz);
1618                         if (count < 0) {
1619                                 if (offset == range_start)
1620                                         break; /* fall back to read/write loop */
1621                                 goto fin;
1622                         }
1623                         IF_FEATURE_HTTPD_RANGES(range_len -= sz;)
1624                         if (count == 0 || range_len == 0)
1625                                 log_and_exit();
1626                 }
1627         }
1628 #endif
1629         while ((count = safe_read(fd, iobuf, IOBUF_SIZE)) > 0) {
1630                 ssize_t n;
1631                 IF_FEATURE_HTTPD_RANGES(if (count > range_len) count = range_len;)
1632                 n = full_write(STDOUT_FILENO, iobuf, count);
1633                 if (count != n)
1634                         break;
1635                 IF_FEATURE_HTTPD_RANGES(range_len -= count;)
1636                 if (range_len == 0)
1637                         break;
1638         }
1639         if (count < 0) {
1640  IF_FEATURE_HTTPD_USE_SENDFILE(fin:)
1641                 if (verbose > 1)
1642                         bb_perror_msg("error");
1643         }
1644         log_and_exit();
1645 }
1646
1647 static int checkPermIP(void)
1648 {
1649         Htaccess_IP *cur;
1650
1651         for (cur = ip_a_d; cur; cur = cur->next) {
1652 #if DEBUG
1653                 fprintf(stderr,
1654                         "checkPermIP: '%s' ? '%u.%u.%u.%u/%u.%u.%u.%u'\n",
1655                         rmt_ip_str,
1656                         (unsigned char)(cur->ip >> 24),
1657                         (unsigned char)(cur->ip >> 16),
1658                         (unsigned char)(cur->ip >> 8),
1659                         (unsigned char)(cur->ip),
1660                         (unsigned char)(cur->mask >> 24),
1661                         (unsigned char)(cur->mask >> 16),
1662                         (unsigned char)(cur->mask >> 8),
1663                         (unsigned char)(cur->mask)
1664                 );
1665 #endif
1666                 if ((rmt_ip & cur->mask) == cur->ip)
1667                         return (cur->allow_deny == 'A'); /* A -> 1 */
1668         }
1669
1670         return !flg_deny_all; /* depends on whether we saw "D:*" */
1671 }
1672
1673 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
1674
1675 # if ENABLE_FEATURE_HTTPD_AUTH_MD5 && ENABLE_PAM
1676 struct pam_userinfo {
1677         const char *name;
1678         const char *pw;
1679 };
1680
1681 static int pam_talker(int num_msg,
1682                 const struct pam_message **msg,
1683                 struct pam_response **resp,
1684                 void *appdata_ptr)
1685 {
1686         int i;
1687         struct pam_userinfo *userinfo = (struct pam_userinfo *) appdata_ptr;
1688         struct pam_response *response;
1689
1690         if (!resp || !msg || !userinfo)
1691                 return PAM_CONV_ERR;
1692
1693         /* allocate memory to store response */
1694         response = xzalloc(num_msg * sizeof(*response));
1695
1696         /* copy values */
1697         for (i = 0; i < num_msg; i++) {
1698                 const char *s;
1699
1700                 switch (msg[i]->msg_style) {
1701                 case PAM_PROMPT_ECHO_ON:
1702                         s = userinfo->name;
1703                         break;
1704                 case PAM_PROMPT_ECHO_OFF:
1705                         s = userinfo->pw;
1706                         break;
1707                 case PAM_ERROR_MSG:
1708                 case PAM_TEXT_INFO:
1709                         s = "";
1710                         break;
1711                 default:
1712                         free(response);
1713                         return PAM_CONV_ERR;
1714                 }
1715                 response[i].resp = xstrdup(s);
1716                 if (PAM_SUCCESS != 0)
1717                         response[i].resp_retcode = PAM_SUCCESS;
1718         }
1719         *resp = response;
1720         return PAM_SUCCESS;
1721 }
1722 # endif
1723
1724 /*
1725  * Config file entries are of the form "/<path>:<user>:<passwd>".
1726  * If config file has no prefix match for path, access is allowed.
1727  *
1728  * path                 The file path
1729  * user_and_passwd      "user:passwd" to validate
1730  *
1731  * Returns 1 if user_and_passwd is OK.
1732  */
1733 static int check_user_passwd(const char *path, char *user_and_passwd)
1734 {
1735         Htaccess *cur;
1736         const char *prev = NULL;
1737
1738         for (cur = g_auth; cur; cur = cur->next) {
1739                 const char *dir_prefix;
1740                 size_t len;
1741                 int r;
1742
1743                 dir_prefix = cur->before_colon;
1744
1745                 /* WHY? */
1746                 /* If already saw a match, don't accept other different matches */
1747                 if (prev && strcmp(prev, dir_prefix) != 0)
1748                         continue;
1749
1750                 if (DEBUG)
1751                         fprintf(stderr, "checkPerm: '%s' ? '%s'\n", dir_prefix, user_and_passwd);
1752
1753                 /* If it's not a prefix match, continue searching */
1754                 len = strlen(dir_prefix);
1755                 if (len != 1 /* dir_prefix "/" matches all, don't need to check */
1756                  && (strncmp(dir_prefix, path, len) != 0
1757                     || (path[len] != '/' && path[len] != '\0')
1758                     )
1759                 ) {
1760                         continue;
1761                 }
1762
1763                 /* Path match found */
1764                 prev = dir_prefix;
1765
1766                 if (ENABLE_FEATURE_HTTPD_AUTH_MD5) {
1767                         char *colon_after_user;
1768                         const char *passwd;
1769 # if ENABLE_FEATURE_SHADOWPASSWDS && !ENABLE_PAM
1770                         char sp_buf[256];
1771 # endif
1772
1773                         colon_after_user = strchr(user_and_passwd, ':');
1774                         if (!colon_after_user)
1775                                 goto bad_input;
1776                         passwd = strchr(cur->after_colon, ':');
1777                         if (!passwd)
1778                                 goto bad_input;
1779                         passwd++;
1780                         if (passwd[0] == '*') {
1781 # if ENABLE_PAM
1782                                 struct pam_userinfo userinfo;
1783                                 struct pam_conv conv_info = { &pam_talker, (void *) &userinfo };
1784                                 pam_handle_t *pamh;
1785
1786                                 /* compare "user:" */
1787                                 if (cur->after_colon[0] != '*'
1788                                  && strncmp(cur->after_colon, user_and_passwd, colon_after_user - user_and_passwd + 1) != 0
1789                                 ) {
1790                                         continue;
1791                                 }
1792                                 /* this cfg entry is '*' or matches username from peer */
1793                                 *colon_after_user = '\0';
1794                                 userinfo.name = user_and_passwd;
1795                                 userinfo.pw = colon_after_user + 1;
1796                                 r = pam_start("httpd", user_and_passwd, &conv_info, &pamh) != PAM_SUCCESS;
1797                                 if (r == 0) {
1798                                         r = pam_authenticate(pamh, PAM_DISALLOW_NULL_AUTHTOK) != PAM_SUCCESS
1799                                          || pam_acct_mgmt(pamh, PAM_DISALLOW_NULL_AUTHTOK)    != PAM_SUCCESS
1800                                         ;
1801                                         pam_end(pamh, PAM_SUCCESS);
1802                                 }
1803                                 *colon_after_user = ':';
1804                                 goto end_check_passwd;
1805 # else
1806 #  if ENABLE_FEATURE_SHADOWPASSWDS
1807                                 /* Using _r function to avoid pulling in static buffers */
1808                                 struct spwd spw;
1809 #  endif
1810                                 struct passwd *pw;
1811
1812                                 *colon_after_user = '\0';
1813                                 pw = getpwnam(user_and_passwd);
1814                                 *colon_after_user = ':';
1815                                 if (!pw || !pw->pw_passwd)
1816                                         continue;
1817                                 passwd = pw->pw_passwd;
1818 #  if ENABLE_FEATURE_SHADOWPASSWDS
1819                                 if ((passwd[0] == 'x' || passwd[0] == '*') && !passwd[1]) {
1820                                         /* getspnam_r may return 0 yet set result to NULL.
1821                                          * At least glibc 2.4 does this. Be extra paranoid here. */
1822                                         struct spwd *result = NULL;
1823                                         r = getspnam_r(pw->pw_name, &spw, sp_buf, sizeof(sp_buf), &result);
1824                                         if (r == 0 && result)
1825                                                 passwd = result->sp_pwdp;
1826                                 }
1827 #  endif
1828 # endif /* ENABLE_PAM */
1829                         }
1830
1831                         /* compare "user:" */
1832                         if (cur->after_colon[0] != '*'
1833                          && strncmp(cur->after_colon, user_and_passwd, colon_after_user - user_and_passwd + 1) != 0
1834                         ) {
1835                                 continue;
1836                         }
1837                         /* this cfg entry is '*' or matches username from peer */
1838
1839                         /* encrypt pwd from peer and check match with local one */
1840                         {
1841                                 char *encrypted = pw_encrypt(
1842                                         /* pwd: */  colon_after_user + 1,
1843                                         /* salt: */ passwd,
1844                                         /* cleanup: */ 0
1845                                 );
1846                                 r = strcmp(encrypted, passwd);
1847                                 free(encrypted);
1848                                 goto end_check_passwd;
1849                         }
1850  bad_input: ;
1851                 }
1852
1853                 /* Comparing plaintext "user:pass" in one go */
1854                 r = strcmp(cur->after_colon, user_and_passwd);
1855  end_check_passwd:
1856                 if (r == 0) {
1857                         remoteuser = xstrndup(user_and_passwd,
1858                                 strchrnul(user_and_passwd, ':') - user_and_passwd
1859                         );
1860                         return 1; /* Ok */
1861                 }
1862         } /* for */
1863
1864         /* 0(bad) if prev is set: matches were found but passwd was wrong */
1865         return (prev == NULL);
1866 }
1867 #endif  /* FEATURE_HTTPD_BASIC_AUTH */
1868
1869 #if ENABLE_FEATURE_HTTPD_PROXY
1870 static Htaccess_Proxy *find_proxy_entry(const char *url)
1871 {
1872         Htaccess_Proxy *p;
1873         for (p = proxy; p; p = p->next) {
1874                 if (strncmp(url, p->url_from, strlen(p->url_from)) == 0)
1875                         return p;
1876         }
1877         return NULL;
1878 }
1879 #endif
1880
1881 /*
1882  * Handle timeouts
1883  */
1884 static void send_REQUEST_TIMEOUT_and_exit(int sig) NORETURN;
1885 static void send_REQUEST_TIMEOUT_and_exit(int sig UNUSED_PARAM)
1886 {
1887         send_headers_and_exit(HTTP_REQUEST_TIMEOUT);
1888 }
1889
1890 /*
1891  * Handle an incoming http request and exit.
1892  */
1893 static void handle_incoming_and_exit(const len_and_sockaddr *fromAddr) NORETURN;
1894 static void handle_incoming_and_exit(const len_and_sockaddr *fromAddr)
1895 {
1896         static const char request_GET[] ALIGN1 = "GET";
1897         struct stat sb;
1898         char *urlcopy;
1899         char *urlp;
1900         char *tptr;
1901 #if ENABLE_FEATURE_HTTPD_CGI
1902         static const char request_HEAD[] ALIGN1 = "HEAD";
1903         const char *prequest;
1904         char *cookie = NULL;
1905         char *content_type = NULL;
1906         unsigned long length = 0;
1907 #elif ENABLE_FEATURE_HTTPD_PROXY
1908 #define prequest request_GET
1909         unsigned long length = 0;
1910 #endif
1911 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
1912         smallint authorized = -1;
1913 #endif
1914         smallint ip_allowed;
1915         char http_major_version;
1916 #if ENABLE_FEATURE_HTTPD_PROXY
1917         char http_minor_version;
1918         char *header_buf = header_buf; /* for gcc */
1919         char *header_ptr = header_ptr;
1920         Htaccess_Proxy *proxy_entry;
1921 #endif
1922
1923         /* Allocation of iobuf is postponed until now
1924          * (IOW, server process doesn't need to waste 8k) */
1925         iobuf = xmalloc(IOBUF_SIZE);
1926
1927         rmt_ip = 0;
1928         if (fromAddr->u.sa.sa_family == AF_INET) {
1929                 rmt_ip = ntohl(fromAddr->u.sin.sin_addr.s_addr);
1930         }
1931 #if ENABLE_FEATURE_IPV6
1932         if (fromAddr->u.sa.sa_family == AF_INET6
1933          && fromAddr->u.sin6.sin6_addr.s6_addr32[0] == 0
1934          && fromAddr->u.sin6.sin6_addr.s6_addr32[1] == 0
1935          && ntohl(fromAddr->u.sin6.sin6_addr.s6_addr32[2]) == 0xffff)
1936                 rmt_ip = ntohl(fromAddr->u.sin6.sin6_addr.s6_addr32[3]);
1937 #endif
1938         if (ENABLE_FEATURE_HTTPD_CGI || DEBUG || verbose) {
1939                 /* NB: can be NULL (user runs httpd -i by hand?) */
1940                 rmt_ip_str = xmalloc_sockaddr2dotted(&fromAddr->u.sa);
1941         }
1942         if (verbose) {
1943                 /* this trick makes -v logging much simpler */
1944                 if (rmt_ip_str)
1945                         applet_name = rmt_ip_str;
1946                 if (verbose > 2)
1947                         bb_error_msg("connected");
1948         }
1949
1950         /* Install timeout handler. get_line() needs it. */
1951         signal(SIGALRM, send_REQUEST_TIMEOUT_and_exit);
1952
1953         if (!get_line()) /* EOF or error or empty line */
1954                 send_headers_and_exit(HTTP_BAD_REQUEST);
1955
1956         /* Determine type of request (GET/POST) */
1957         urlp = strpbrk(iobuf, " \t");
1958         if (urlp == NULL)
1959                 send_headers_and_exit(HTTP_BAD_REQUEST);
1960         *urlp++ = '\0';
1961 #if ENABLE_FEATURE_HTTPD_CGI
1962         prequest = request_GET;
1963         if (strcasecmp(iobuf, prequest) != 0) {
1964                 prequest = request_HEAD;
1965                 if (strcasecmp(iobuf, prequest) != 0) {
1966                         prequest = "POST";
1967                         if (strcasecmp(iobuf, prequest) != 0)
1968                                 send_headers_and_exit(HTTP_NOT_IMPLEMENTED);
1969                 }
1970         }
1971 #else
1972         if (strcasecmp(iobuf, request_GET) != 0)
1973                 send_headers_and_exit(HTTP_NOT_IMPLEMENTED);
1974 #endif
1975         urlp = skip_whitespace(urlp);
1976         if (urlp[0] != '/')
1977                 send_headers_and_exit(HTTP_BAD_REQUEST);
1978
1979         /* Find end of URL and parse HTTP version, if any */
1980         http_major_version = '0';
1981         IF_FEATURE_HTTPD_PROXY(http_minor_version = '0';)
1982         tptr = strchrnul(urlp, ' ');
1983         /* Is it " HTTP/"? */
1984         if (tptr[0] && strncmp(tptr + 1, HTTP_200, 5) == 0) {
1985                 http_major_version = tptr[6];
1986                 IF_FEATURE_HTTPD_PROXY(http_minor_version = tptr[8];)
1987         }
1988         *tptr = '\0';
1989
1990         /* Copy URL from after "GET "/"POST " to stack-allocated char[] */
1991         urlcopy = alloca((tptr - urlp) + 2 + strlen(index_page));
1992         /*if (urlcopy == NULL)
1993          *      send_headers_and_exit(HTTP_INTERNAL_SERVER_ERROR);*/
1994         strcpy(urlcopy, urlp);
1995         /* NB: urlcopy ptr is never changed after this */
1996
1997         /* Extract url args if present */
1998         /* g_query = NULL; - already is */
1999         tptr = strchr(urlcopy, '?');
2000         if (tptr) {
2001                 *tptr++ = '\0';
2002                 g_query = tptr;
2003         }
2004
2005         /* Decode URL escape sequences */
2006         tptr = percent_decode_in_place(urlcopy, /*strict:*/ 1);
2007         if (tptr == NULL)
2008                 send_headers_and_exit(HTTP_BAD_REQUEST);
2009         if (tptr == urlcopy + 1) {
2010                 /* '/' or NUL is encoded */
2011                 send_headers_and_exit(HTTP_NOT_FOUND);
2012         }
2013
2014         /* Canonicalize path */
2015         /* Algorithm stolen from libbb bb_simplify_path(),
2016          * but don't strdup, retain trailing slash, protect root */
2017         urlp = tptr = urlcopy;
2018         for (;;) {
2019                 if (*urlp == '/') {
2020                         /* skip duplicate (or initial) slash */
2021                         if (*tptr == '/') {
2022                                 goto next_char;
2023                         }
2024                         if (*tptr == '.') {
2025                                 if (tptr[1] == '.' && (tptr[2] == '/' || tptr[2] == '\0')) {
2026                                         /* "..": be careful */
2027                                         /* protect root */
2028                                         if (urlp == urlcopy)
2029                                                 send_headers_and_exit(HTTP_BAD_REQUEST);
2030                                         /* omit previous dir */
2031                                         while (*--urlp != '/')
2032                                                 continue;
2033                                         /* skip to "./" or ".<NUL>" */
2034                                         tptr++;
2035                                 }
2036                                 if (tptr[1] == '/' || tptr[1] == '\0') {
2037                                         /* skip extra "/./" */
2038                                         goto next_char;
2039                                 }
2040                         }
2041                 }
2042                 *++urlp = *tptr;
2043                 if (*urlp == '\0')
2044                         break;
2045  next_char:
2046                 tptr++;
2047         }
2048
2049         /* If URL is a directory, add '/' */
2050         if (urlp[-1] != '/') {
2051                 if (is_directory(urlcopy + 1, 1, NULL)) {
2052                         found_moved_temporarily = urlcopy;
2053                 }
2054         }
2055
2056         /* Log it */
2057         if (verbose > 1)
2058                 bb_error_msg("url:%s", urlcopy);
2059
2060         tptr = urlcopy;
2061         ip_allowed = checkPermIP();
2062         while (ip_allowed && (tptr = strchr(tptr + 1, '/')) != NULL) {
2063                 /* have path1/path2 */
2064                 *tptr = '\0';
2065                 if (is_directory(urlcopy + 1, 1, NULL)) {
2066                         /* may have subdir config */
2067                         parse_conf(urlcopy + 1, SUBDIR_PARSE);
2068                         ip_allowed = checkPermIP();
2069                 }
2070                 *tptr = '/';
2071         }
2072
2073 #if ENABLE_FEATURE_HTTPD_PROXY
2074         proxy_entry = find_proxy_entry(urlcopy);
2075         if (proxy_entry)
2076                 header_buf = header_ptr = xmalloc(IOBUF_SIZE);
2077 #endif
2078
2079         if (http_major_version >= '0') {
2080                 /* Request was with "... HTTP/nXXX", and n >= 0 */
2081
2082                 /* Read until blank line */
2083                 while (1) {
2084                         if (!get_line())
2085                                 break; /* EOF or error or empty line */
2086                         if (DEBUG)
2087                                 bb_error_msg("header: '%s'", iobuf);
2088
2089 #if ENABLE_FEATURE_HTTPD_PROXY
2090                         /* We need 2 more bytes for yet another "\r\n" -
2091                          * see near fdprintf(proxy_fd...) further below */
2092                         if (proxy_entry && (header_ptr - header_buf) < IOBUF_SIZE - 2) {
2093                                 int len = strlen(iobuf);
2094                                 if (len > IOBUF_SIZE - (header_ptr - header_buf) - 4)
2095                                         len = IOBUF_SIZE - (header_ptr - header_buf) - 4;
2096                                 memcpy(header_ptr, iobuf, len);
2097                                 header_ptr += len;
2098                                 header_ptr[0] = '\r';
2099                                 header_ptr[1] = '\n';
2100                                 header_ptr += 2;
2101                         }
2102 #endif
2103
2104 #if ENABLE_FEATURE_HTTPD_CGI || ENABLE_FEATURE_HTTPD_PROXY
2105                         /* Try and do our best to parse more lines */
2106                         if ((STRNCASECMP(iobuf, "Content-length:") == 0)) {
2107                                 /* extra read only for POST */
2108                                 if (prequest != request_GET
2109 # if ENABLE_FEATURE_HTTPD_CGI
2110                                  && prequest != request_HEAD
2111 # endif
2112                                 ) {
2113                                         tptr = skip_whitespace(iobuf + sizeof("Content-length:") - 1);
2114                                         if (!tptr[0])
2115                                                 send_headers_and_exit(HTTP_BAD_REQUEST);
2116                                         /* not using strtoul: it ignores leading minus! */
2117                                         length = bb_strtou(tptr, NULL, 10);
2118                                         /* length is "ulong", but we need to pass it to int later */
2119                                         if (errno || length > INT_MAX)
2120                                                 send_headers_and_exit(HTTP_BAD_REQUEST);
2121                                 }
2122                         }
2123 #endif
2124 #if ENABLE_FEATURE_HTTPD_CGI
2125                         else if (STRNCASECMP(iobuf, "Cookie:") == 0) {
2126                                 cookie = xstrdup(skip_whitespace(iobuf + sizeof("Cookie:")-1));
2127                         } else if (STRNCASECMP(iobuf, "Content-Type:") == 0) {
2128                                 content_type = xstrdup(skip_whitespace(iobuf + sizeof("Content-Type:")-1));
2129                         } else if (STRNCASECMP(iobuf, "Referer:") == 0) {
2130                                 referer = xstrdup(skip_whitespace(iobuf + sizeof("Referer:")-1));
2131                         } else if (STRNCASECMP(iobuf, "User-Agent:") == 0) {
2132                                 user_agent = xstrdup(skip_whitespace(iobuf + sizeof("User-Agent:")-1));
2133                         } else if (STRNCASECMP(iobuf, "Host:") == 0) {
2134                                 host = xstrdup(skip_whitespace(iobuf + sizeof("Host:")-1));
2135                         } else if (STRNCASECMP(iobuf, "Accept:") == 0) {
2136                                 http_accept = xstrdup(skip_whitespace(iobuf + sizeof("Accept:")-1));
2137                         } else if (STRNCASECMP(iobuf, "Accept-Language:") == 0) {
2138                                 http_accept_language = xstrdup(skip_whitespace(iobuf + sizeof("Accept-Language:")-1));
2139                         }
2140 #endif
2141 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
2142                         if (STRNCASECMP(iobuf, "Authorization:") == 0) {
2143                                 /* We only allow Basic credentials.
2144                                  * It shows up as "Authorization: Basic <user>:<passwd>" where
2145                                  * "<user>:<passwd>" is base64 encoded.
2146                                  */
2147                                 tptr = skip_whitespace(iobuf + sizeof("Authorization:")-1);
2148                                 if (STRNCASECMP(tptr, "Basic") != 0)
2149                                         continue;
2150                                 tptr += sizeof("Basic")-1;
2151                                 /* decodeBase64() skips whitespace itself */
2152                                 decodeBase64(tptr);
2153                                 authorized = check_user_passwd(urlcopy, tptr);
2154                         }
2155 #endif
2156 #if ENABLE_FEATURE_HTTPD_RANGES
2157                         if (STRNCASECMP(iobuf, "Range:") == 0) {
2158                                 /* We know only bytes=NNN-[MMM] */
2159                                 char *s = skip_whitespace(iobuf + sizeof("Range:")-1);
2160                                 if (strncmp(s, "bytes=", 6) == 0) {
2161                                         s += sizeof("bytes=")-1;
2162                                         range_start = BB_STRTOOFF(s, &s, 10);
2163                                         if (s[0] != '-' || range_start < 0) {
2164                                                 range_start = 0;
2165                                         } else if (s[1]) {
2166                                                 range_end = BB_STRTOOFF(s+1, NULL, 10);
2167                                                 if (errno || range_end < range_start)
2168                                                         range_start = 0;
2169                                         }
2170                                 }
2171                         }
2172 #endif
2173 #if ENABLE_FEATURE_HTTPD_GZIP
2174                         if (STRNCASECMP(iobuf, "Accept-Encoding:") == 0) {
2175                                 /* Note: we do not support "gzip;q=0"
2176                                  * method of _disabling_ gzip
2177                                  * delivery. No one uses that, though */
2178                                 const char *s = strstr(iobuf, "gzip");
2179                                 if (s) {
2180                                         // want more thorough checks?
2181                                         //if (s[-1] == ' '
2182                                         // || s[-1] == ','
2183                                         // || s[-1] == ':'
2184                                         //) {
2185                                                 content_gzip = 1;
2186                                         //}
2187                                 }
2188                         }
2189 #endif
2190                 } /* while extra header reading */
2191         }
2192
2193         /* We are done reading headers, disable peer timeout */
2194         alarm(0);
2195
2196         if (strcmp(bb_basename(urlcopy), HTTPD_CONF) == 0 || !ip_allowed) {
2197                 /* protect listing [/path]/httpd.conf or IP deny */
2198                 send_headers_and_exit(HTTP_FORBIDDEN);
2199         }
2200
2201 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
2202         /* Case: no "Authorization:" was seen, but page might require passwd.
2203          * Check that with dummy user:pass */
2204         if (authorized < 0)
2205                 authorized = check_user_passwd(urlcopy, (char *) "");
2206         if (!authorized)
2207                 send_headers_and_exit(HTTP_UNAUTHORIZED);
2208 #endif
2209
2210         if (found_moved_temporarily) {
2211                 send_headers_and_exit(HTTP_MOVED_TEMPORARILY);
2212         }
2213
2214 #if ENABLE_FEATURE_HTTPD_PROXY
2215         if (proxy_entry != NULL) {
2216                 int proxy_fd;
2217                 len_and_sockaddr *lsa;
2218
2219                 proxy_fd = socket(AF_INET, SOCK_STREAM, 0);
2220                 if (proxy_fd < 0)
2221                         send_headers_and_exit(HTTP_INTERNAL_SERVER_ERROR);
2222                 lsa = host2sockaddr(proxy_entry->host_port, 80);
2223                 if (lsa == NULL)
2224                         send_headers_and_exit(HTTP_INTERNAL_SERVER_ERROR);
2225                 if (connect(proxy_fd, &lsa->u.sa, lsa->len) < 0)
2226                         send_headers_and_exit(HTTP_INTERNAL_SERVER_ERROR);
2227                 fdprintf(proxy_fd, "%s %s%s%s%s HTTP/%c.%c\r\n",
2228                                 prequest, /* GET or POST */
2229                                 proxy_entry->url_to, /* url part 1 */
2230                                 urlcopy + strlen(proxy_entry->url_from), /* url part 2 */
2231                                 (g_query ? "?" : ""), /* "?" (maybe) */
2232                                 (g_query ? g_query : ""), /* query string (maybe) */
2233                                 http_major_version, http_minor_version);
2234                 header_ptr[0] = '\r';
2235                 header_ptr[1] = '\n';
2236                 header_ptr += 2;
2237                 write(proxy_fd, header_buf, header_ptr - header_buf);
2238                 free(header_buf); /* on the order of 8k, free it */
2239                 cgi_io_loop_and_exit(proxy_fd, proxy_fd, length);
2240         }
2241 #endif
2242
2243         tptr = urlcopy + 1;      /* skip first '/' */
2244
2245 #if ENABLE_FEATURE_HTTPD_CGI
2246         if (strncmp(tptr, "cgi-bin/", 8) == 0) {
2247                 if (tptr[8] == '\0') {
2248                         /* protect listing "cgi-bin/" */
2249                         send_headers_and_exit(HTTP_FORBIDDEN);
2250                 }
2251                 send_cgi_and_exit(urlcopy, prequest, length, cookie, content_type);
2252         }
2253 #endif
2254
2255         if (urlp[-1] == '/')
2256                 strcpy(urlp, index_page);
2257         if (stat(tptr, &sb) == 0) {
2258 #if ENABLE_FEATURE_HTTPD_CONFIG_WITH_SCRIPT_INTERPR
2259                 char *suffix = strrchr(tptr, '.');
2260                 if (suffix) {
2261                         Htaccess *cur;
2262                         for (cur = script_i; cur; cur = cur->next) {
2263                                 if (strcmp(cur->before_colon + 1, suffix) == 0) {
2264                                         send_cgi_and_exit(urlcopy, prequest, length, cookie, content_type);
2265                                 }
2266                         }
2267                 }
2268 #endif
2269                 file_size = sb.st_size;
2270                 last_mod = sb.st_mtime;
2271         }
2272 #if ENABLE_FEATURE_HTTPD_CGI
2273         else if (urlp[-1] == '/') {
2274                 /* It's a dir URL and there is no index.html
2275                  * Try cgi-bin/index.cgi */
2276                 if (access("/cgi-bin/index.cgi"+1, X_OK) == 0) {
2277                         urlp[0] = '\0';
2278                         g_query = urlcopy;
2279                         send_cgi_and_exit("/cgi-bin/index.cgi", prequest, length, cookie, content_type);
2280                 }
2281         }
2282         /* else fall through to send_file, it errors out if open fails: */
2283
2284         if (prequest != request_GET && prequest != request_HEAD) {
2285                 /* POST for files does not make sense */
2286                 send_headers_and_exit(HTTP_NOT_IMPLEMENTED);
2287         }
2288         send_file_and_exit(tptr,
2289                 (prequest != request_HEAD ? SEND_HEADERS_AND_BODY : SEND_HEADERS)
2290         );
2291 #else
2292         send_file_and_exit(tptr, SEND_HEADERS_AND_BODY);
2293 #endif
2294 }
2295
2296 /*
2297  * The main http server function.
2298  * Given a socket, listen for new connections and farm out
2299  * the processing as a [v]forked process.
2300  * Never returns.
2301  */
2302 #if BB_MMU
2303 static void mini_httpd(int server_socket) NORETURN;
2304 static void mini_httpd(int server_socket)
2305 {
2306         /* NB: it's best to not use xfuncs in this loop before fork().
2307          * Otherwise server may die on transient errors (temporary
2308          * out-of-memory condition, etc), which is Bad(tm).
2309          * Try to do any dangerous calls after fork.
2310          */
2311         while (1) {
2312                 int n;
2313                 len_and_sockaddr fromAddr;
2314
2315                 /* Wait for connections... */
2316                 fromAddr.len = LSA_SIZEOF_SA;
2317                 n = accept(server_socket, &fromAddr.u.sa, &fromAddr.len);
2318                 if (n < 0)
2319                         continue;
2320
2321                 /* set the KEEPALIVE option to cull dead connections */
2322                 setsockopt(n, SOL_SOCKET, SO_KEEPALIVE, &const_int_1, sizeof(const_int_1));
2323
2324                 if (fork() == 0) {
2325                         /* child */
2326                         /* Do not reload config on HUP */
2327                         signal(SIGHUP, SIG_IGN);
2328                         close(server_socket);
2329                         xmove_fd(n, 0);
2330                         xdup2(0, 1);
2331
2332                         handle_incoming_and_exit(&fromAddr);
2333                 }
2334                 /* parent, or fork failed */
2335                 close(n);
2336         } /* while (1) */
2337         /* never reached */
2338 }
2339 #else
2340 static void mini_httpd_nommu(int server_socket, int argc, char **argv) NORETURN;
2341 static void mini_httpd_nommu(int server_socket, int argc, char **argv)
2342 {
2343         char *argv_copy[argc + 2];
2344
2345         argv_copy[0] = argv[0];
2346         argv_copy[1] = (char*)"-i";
2347         memcpy(&argv_copy[2], &argv[1], argc * sizeof(argv[0]));
2348
2349         /* NB: it's best to not use xfuncs in this loop before vfork().
2350          * Otherwise server may die on transient errors (temporary
2351          * out-of-memory condition, etc), which is Bad(tm).
2352          * Try to do any dangerous calls after fork.
2353          */
2354         while (1) {
2355                 int n;
2356                 len_and_sockaddr fromAddr;
2357
2358                 /* Wait for connections... */
2359                 fromAddr.len = LSA_SIZEOF_SA;
2360                 n = accept(server_socket, &fromAddr.u.sa, &fromAddr.len);
2361                 if (n < 0)
2362                         continue;
2363
2364                 /* set the KEEPALIVE option to cull dead connections */
2365                 setsockopt(n, SOL_SOCKET, SO_KEEPALIVE, &const_int_1, sizeof(const_int_1));
2366
2367                 if (vfork() == 0) {
2368                         /* child */
2369                         /* Do not reload config on HUP */
2370                         signal(SIGHUP, SIG_IGN);
2371                         close(server_socket);
2372                         xmove_fd(n, 0);
2373                         xdup2(0, 1);
2374
2375                         /* Run a copy of ourself in inetd mode */
2376                         re_exec(argv_copy);
2377                 }
2378                 argv_copy[0][0] &= 0x7f;
2379                 /* parent, or vfork failed */
2380                 close(n);
2381         } /* while (1) */
2382         /* never reached */
2383 }
2384 #endif
2385
2386 /*
2387  * Process a HTTP connection on stdin/out.
2388  * Never returns.
2389  */
2390 static void mini_httpd_inetd(void) NORETURN;
2391 static void mini_httpd_inetd(void)
2392 {
2393         len_and_sockaddr fromAddr;
2394
2395         memset(&fromAddr, 0, sizeof(fromAddr));
2396         fromAddr.len = LSA_SIZEOF_SA;
2397         /* NB: can fail if user runs it by hand and types in http cmds */
2398         getpeername(0, &fromAddr.u.sa, &fromAddr.len);
2399         handle_incoming_and_exit(&fromAddr);
2400 }
2401
2402 static void sighup_handler(int sig UNUSED_PARAM)
2403 {
2404         parse_conf(DEFAULT_PATH_HTTPD_CONF, SIGNALED_PARSE);
2405 }
2406
2407 enum {
2408         c_opt_config_file = 0,
2409         d_opt_decode_url,
2410         h_opt_home_httpd,
2411         IF_FEATURE_HTTPD_ENCODE_URL_STR(e_opt_encode_url,)
2412         IF_FEATURE_HTTPD_BASIC_AUTH(    r_opt_realm     ,)
2413         IF_FEATURE_HTTPD_AUTH_MD5(      m_opt_md5       ,)
2414         IF_FEATURE_HTTPD_SETUID(        u_opt_setuid    ,)
2415         p_opt_port      ,
2416         p_opt_inetd     ,
2417         p_opt_foreground,
2418         p_opt_verbose   ,
2419         OPT_CONFIG_FILE = 1 << c_opt_config_file,
2420         OPT_DECODE_URL  = 1 << d_opt_decode_url,
2421         OPT_HOME_HTTPD  = 1 << h_opt_home_httpd,
2422         OPT_ENCODE_URL  = IF_FEATURE_HTTPD_ENCODE_URL_STR((1 << e_opt_encode_url)) + 0,
2423         OPT_REALM       = IF_FEATURE_HTTPD_BASIC_AUTH(    (1 << r_opt_realm     )) + 0,
2424         OPT_MD5         = IF_FEATURE_HTTPD_AUTH_MD5(      (1 << m_opt_md5       )) + 0,
2425         OPT_SETUID      = IF_FEATURE_HTTPD_SETUID(        (1 << u_opt_setuid    )) + 0,
2426         OPT_PORT        = 1 << p_opt_port,
2427         OPT_INETD       = 1 << p_opt_inetd,
2428         OPT_FOREGROUND  = 1 << p_opt_foreground,
2429         OPT_VERBOSE     = 1 << p_opt_verbose,
2430 };
2431
2432
2433 int httpd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
2434 int httpd_main(int argc UNUSED_PARAM, char **argv)
2435 {
2436         int server_socket = server_socket; /* for gcc */
2437         unsigned opt;
2438         char *url_for_decode;
2439         IF_FEATURE_HTTPD_ENCODE_URL_STR(const char *url_for_encode;)
2440         IF_FEATURE_HTTPD_SETUID(const char *s_ugid = NULL;)
2441         IF_FEATURE_HTTPD_SETUID(struct bb_uidgid_t ugid;)
2442         IF_FEATURE_HTTPD_AUTH_MD5(const char *pass;)
2443
2444         INIT_G();
2445
2446 #if ENABLE_LOCALE_SUPPORT
2447         /* Undo busybox.c: we want to speak English in http (dates etc) */
2448         setlocale(LC_TIME, "C");
2449 #endif
2450
2451         home_httpd = xrealloc_getcwd_or_warn(NULL);
2452         /* -v counts, -i implies -f */
2453         opt_complementary = "vv:if";
2454         /* We do not "absolutize" path given by -h (home) opt.
2455          * If user gives relative path in -h,
2456          * $SCRIPT_FILENAME will not be set. */
2457         opt = getopt32(argv, "c:d:h:"
2458                         IF_FEATURE_HTTPD_ENCODE_URL_STR("e:")
2459                         IF_FEATURE_HTTPD_BASIC_AUTH("r:")
2460                         IF_FEATURE_HTTPD_AUTH_MD5("m:")
2461                         IF_FEATURE_HTTPD_SETUID("u:")
2462                         "p:ifv",
2463                         &opt_c_configFile, &url_for_decode, &home_httpd
2464                         IF_FEATURE_HTTPD_ENCODE_URL_STR(, &url_for_encode)
2465                         IF_FEATURE_HTTPD_BASIC_AUTH(, &g_realm)
2466                         IF_FEATURE_HTTPD_AUTH_MD5(, &pass)
2467                         IF_FEATURE_HTTPD_SETUID(, &s_ugid)
2468                         , &bind_addr_or_port
2469                         , &verbose
2470                 );
2471         if (opt & OPT_DECODE_URL) {
2472                 fputs(percent_decode_in_place(url_for_decode, /*strict:*/ 0), stdout);
2473                 return 0;
2474         }
2475 #if ENABLE_FEATURE_HTTPD_ENCODE_URL_STR
2476         if (opt & OPT_ENCODE_URL) {
2477                 fputs(encodeString(url_for_encode), stdout);
2478                 return 0;
2479         }
2480 #endif
2481 #if ENABLE_FEATURE_HTTPD_AUTH_MD5
2482         if (opt & OPT_MD5) {
2483                 char salt[sizeof("$1$XXXXXXXX")];
2484                 salt[0] = '$';
2485                 salt[1] = '1';
2486                 salt[2] = '$';
2487                 crypt_make_salt(salt + 3, 4);
2488                 puts(pw_encrypt(pass, salt, /*cleanup:*/ 0));
2489                 return 0;
2490         }
2491 #endif
2492 #if ENABLE_FEATURE_HTTPD_SETUID
2493         if (opt & OPT_SETUID) {
2494                 xget_uidgid(&ugid, s_ugid);
2495         }
2496 #endif
2497
2498 #if !BB_MMU
2499         if (!(opt & OPT_FOREGROUND)) {
2500                 bb_daemonize_or_rexec(0, argv); /* don't change current directory */
2501         }
2502 #endif
2503
2504         xchdir(home_httpd);
2505         if (!(opt & OPT_INETD)) {
2506                 signal(SIGCHLD, SIG_IGN);
2507                 server_socket = openServer();
2508 #if ENABLE_FEATURE_HTTPD_SETUID
2509                 /* drop privileges */
2510                 if (opt & OPT_SETUID) {
2511                         if (ugid.gid != (gid_t)-1) {
2512                                 if (setgroups(1, &ugid.gid) == -1)
2513                                         bb_perror_msg_and_die("setgroups");
2514                                 xsetgid(ugid.gid);
2515                         }
2516                         xsetuid(ugid.uid);
2517                 }
2518 #endif
2519         }
2520
2521 #if 0
2522         /* User can do it himself: 'env - PATH="$PATH" httpd'
2523          * We don't do it because we don't want to screw users
2524          * which want to do
2525          * 'env - VAR1=val1 VAR2=val2 httpd'
2526          * and have VAR1 and VAR2 values visible in their CGIs.
2527          * Besides, it is also smaller. */
2528         {
2529                 char *p = getenv("PATH");
2530                 /* env strings themself are not freed, no need to xstrdup(p): */
2531                 clearenv();
2532                 if (p)
2533                         putenv(p - 5);
2534 //              if (!(opt & OPT_INETD))
2535 //                      setenv_long("SERVER_PORT", ???);
2536         }
2537 #endif
2538
2539         parse_conf(DEFAULT_PATH_HTTPD_CONF, FIRST_PARSE);
2540         if (!(opt & OPT_INETD))
2541                 signal(SIGHUP, sighup_handler);
2542
2543         xfunc_error_retval = 0;
2544         if (opt & OPT_INETD)
2545                 mini_httpd_inetd();
2546 #if BB_MMU
2547         if (!(opt & OPT_FOREGROUND))
2548                 bb_daemonize(0); /* don't change current directory */
2549         mini_httpd(server_socket); /* never returns */
2550 #else
2551         mini_httpd_nommu(server_socket, argc, argv); /* never returns */
2552 #endif
2553         /* return 0; */
2554 }