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 = -1,
 352         range_end = MAXINT(off_t) - 1,
 353         range_len = MAXINT(off_t),
 354 };
 355 #endif
 356 #define rmt_ip_str        (G.rmt_ip_str       )
 357 #define g_auth            (G.g_auth           )
 358 #define mime_a            (G.mime_a           )
 359 #define script_i          (G.script_i         )
 360 #define iobuf             (G.iobuf            )
 361 #define hdr_ptr           (G.hdr_ptr          )
 362 #define hdr_cnt           (G.hdr_cnt          )
 363 #define http_error_page   (G.http_error_page  )
 364 #define proxy             (G.proxy            )
 365 #if ENABLE_FEATURE_HTTPD_GZIP
 366 # define content_gzip     (G.content_gzip     )
 367 #else
 368 # define content_gzip     0
 369 #endif
 370 #define INIT_G() do { \
 371         SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
 372         IF_FEATURE_HTTPD_BASIC_AUTH(g_realm = "Web Server Authentication";) \
 373         IF_FEATURE_HTTPD_RANGES(range_start = -1;) \
 374         bind_addr_or_port = "80"; \
 375         index_page = index_html; \
 376         file_size = -1; \
 377 } while (0)
 378
 379
 380 #define STRNCASECMP(a, str) strncasecmp((a), (str), sizeof(str)-1)
 381
 382 /* Prototypes */
 383 enum {
 384         SEND_HEADERS     = (1 << 0),
 385         SEND_BODY        = (1 << 1),
 386         SEND_HEADERS_AND_BODY = SEND_HEADERS + SEND_BODY,
 387 };
 388 static void send_file_and_exit(const char *url, int what) NORETURN;
 389
 390 static void free_llist(has_next_ptr **pptr)
 391 {
 392         has_next_ptr *cur = *pptr;
 393         while (cur) {
 394                 has_next_ptr *t = cur;
 395                 cur = cur->next;
 396                 free(t);
 397         }
 398         *pptr = NULL;
 399 }
 400
 401 static ALWAYS_INLINE void free_Htaccess_list(Htaccess **pptr)
 402 {
 403         free_llist((has_next_ptr**)pptr);
 404 }
 405
 406 static ALWAYS_INLINE void free_Htaccess_IP_list(Htaccess_IP **pptr)
 407 {
 408         free_llist((has_next_ptr**)pptr);
 409 }
 410
 411 /* Returns presumed mask width in bits or < 0 on error.
 412  * Updates strp, stores IP at provided pointer */
 413 static int scan_ip(const char **strp, unsigned *ipp, unsigned char endc)
 414 {
 415         const char *p = *strp;
 416         int auto_mask = 8;
 417         unsigned ip = 0;
 418         int j;
 419
 420         if (*p == '/')
 421                 return -auto_mask;
 422
 423         for (j = 0; j < 4; j++) {
 424                 unsigned octet;
 425
 426                 if ((*p < '0' || *p > '9') && *p != '/' && *p)
 427                         return -auto_mask;
 428                 octet = 0;
 429                 while (*p >= '0' && *p <= '9') {
 430                         octet *= 10;
 431                         octet += *p - '0';
 432                         if (octet > 255)
 433                                 return -auto_mask;
 434                         p++;
 435                 }
 436                 if (*p == '.')
 437                         p++;
 438                 if (*p != '/' && *p)
 439                         auto_mask += 8;
 440                 ip = (ip << 8) | octet;
 441         }
 442         if (*p) {
 443                 if (*p != endc)
 444                         return -auto_mask;
 445                 p++;
 446                 if (*p == '\0')
 447                         return -auto_mask;
 448         }
 449         *ipp = ip;
 450         *strp = p;
 451         return auto_mask;
 452 }
 453
 454 /* Returns 0 on success. Stores IP and mask at provided pointers */
 455 static int scan_ip_mask(const char *str, unsigned *ipp, unsigned *maskp)
 456 {
 457         int i;
 458         unsigned mask;
 459         char *p;
 460
 461         i = scan_ip(&str, ipp, '/');
 462         if (i < 0)
 463                 return i;
 464
 465         if (*str) {
 466                 /* there is /xxx after dotted-IP address */
 467                 i = bb_strtou(str, &p, 10);
 468                 if (*p == '.') {
 469                         /* 'xxx' itself is dotted-IP mask, parse it */
 470                         /* (return 0 (success) only if it has N.N.N.N form) */
 471                         return scan_ip(&str, maskp, '\0') - 32;
 472                 }
 473                 if (*p)
 474                         return -1;
 475         }
 476
 477         if (i > 32)
 478                 return -1;
 479
 480         if (sizeof(unsigned) == 4 && i == 32) {
 481                 /* mask >>= 32 below may not work */
 482                 mask = 0;
 483         } else {
 484                 mask = 0xffffffff;
 485                 mask >>= i;
 486         }
 487         /* i == 0 -> *maskp = 0x00000000
 488          * i == 1 -> *maskp = 0x80000000
 489          * i == 4 -> *maskp = 0xf0000000
 490          * i == 31 -> *maskp = 0xfffffffe
 491          * i == 32 -> *maskp = 0xffffffff */
 492         *maskp = (uint32_t)(~mask);
 493         return 0;
 494 }
 495
 496 /*
 497  * Parse configuration file into in-memory linked list.
 498  *
 499  * Any previous IP rules are discarded.
 500  * If the flag argument is not SUBDIR_PARSE then all /path and mime rules
 501  * are also discarded.  That is, previous settings are retained if flag is
 502  * SUBDIR_PARSE.
 503  * Error pages are only parsed on the main config file.
 504  *
 505  * path   Path where to look for httpd.conf (without filename).
 506  * flag   Type of the parse request.
 507  */
 508 /* flag param: */
 509 enum {
 510         FIRST_PARSE    = 0, /* path will be "/etc" */
 511         SIGNALED_PARSE = 1, /* path will be "/etc" */
 512         SUBDIR_PARSE   = 2, /* path will be derived from URL */
 513 };
 514 static void parse_conf(const char *path, int flag)
 515 {
 516         /* internally used extra flag state */
 517         enum { TRY_CURDIR_PARSE = 3 };
 518
 519         FILE *f;
 520         const char *filename;
 521         char buf[160];
 522
 523         /* discard old rules */
 524         free_Htaccess_IP_list(&ip_a_d);
 525         flg_deny_all = 0;
 526         /* retain previous auth and mime config only for subdir parse */
 527         if (flag != SUBDIR_PARSE) {
 528                 free_Htaccess_list(&mime_a);
 529 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
 530                 free_Htaccess_list(&g_auth);
 531 #endif
 532 #if ENABLE_FEATURE_HTTPD_CONFIG_WITH_SCRIPT_INTERPR
 533                 free_Htaccess_list(&script_i);
 534 #endif
 535         }
 536
 537         filename = opt_c_configFile;
 538         if (flag == SUBDIR_PARSE || filename == NULL) {
 539                 filename = alloca(strlen(path) + sizeof(HTTPD_CONF) + 2);
 540                 sprintf((char *)filename, "%s/%s", path, HTTPD_CONF);
 541         }
 542
 543         while ((f = fopen_for_read(filename)) == NULL) {
 544                 if (flag >= SUBDIR_PARSE) { /* SUBDIR or TRY_CURDIR */
 545                         /* config file not found, no changes to config */
 546                         return;
 547                 }
 548                 if (flag == FIRST_PARSE) {
 549                         /* -c CONFFILE given, but CONFFILE doesn't exist? */
 550                         if (opt_c_configFile)
 551                                 bb_simple_perror_msg_and_die(opt_c_configFile);
 552                         /* else: no -c, thus we looked at /etc/httpd.conf,
 553                          * and it's not there. try ./httpd.conf: */
 554                 }
 555                 flag = TRY_CURDIR_PARSE;
 556                 filename = HTTPD_CONF;
 557         }
 558
 559 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
 560         /* in "/file:user:pass" lines, we prepend path in subdirs */
 561         if (flag != SUBDIR_PARSE)
 562                 path = "";
 563 #endif
 564         /* The lines can be:
 565          *
 566          * I:default_index_file
 567          * H:http_home
 568          * [AD]:IP[/mask]   # allow/deny, * for wildcard
 569          * Ennn:error.html  # error page for status nnn
 570          * P:/url:[http://]hostname[:port]/new/path # reverse proxy
 571          * .ext:mime/type   # mime type
 572          * *.php:/path/php  # run xxx.php through an interpreter
 573          * /file:user:pass  # username and password
 574          */
 575         while (fgets(buf, sizeof(buf), f) != NULL) {
 576                 unsigned strlen_buf;
 577                 unsigned char ch;
 578                 char *after_colon;
 579
 580                 { /* remove all whitespace, and # comments */
 581                         char *p, *p0;
 582
 583                         p0 = buf;
 584                         /* skip non-whitespace beginning. Often the whole line
 585                          * is non-whitespace. We want this case to work fast,
 586                          * without needless copying, therefore we don't merge
 587                          * this operation into next while loop. */
 588                         while ((ch = *p0) != '\0' && ch != '\n' && ch != '#'
 589                          && ch != ' ' && ch != '\t'
 590                         ) {
 591                                 p0++;
 592                         }
 593                         p = p0;
 594                         /* if we enter this loop, we have some whitespace.
 595                          * discard it */
 596                         while (ch != '\0' && ch != '\n' && ch != '#') {
 597                                 if (ch != ' ' && ch != '\t') {
 598                                         *p++ = ch;
 599                                 }
 600                                 ch = *++p0;
 601                         }
 602                         *p = '\0';
 603                         strlen_buf = p - buf;
 604                         if (strlen_buf == 0)
 605                                 continue; /* empty line */
 606                 }
 607
 608                 after_colon = strchr(buf, ':');
 609                 /* strange line? */
 610                 if (after_colon == NULL || *++after_colon == '\0')
 611                         goto config_error;
 612
 613                 ch = (buf[0] & ~0x20); /* toupper if it's a letter */
 614
 615                 if (ch == 'I') {
 616                         if (index_page != index_html)
 617                                 free((char*)index_page);
 618                         index_page = xstrdup(after_colon);
 619                         continue;
 620                 }
 621
 622                 /* do not allow jumping around using H in subdir's configs */
 623                 if (flag == FIRST_PARSE && ch == 'H') {
 624                         home_httpd = xstrdup(after_colon);
 625                         xchdir(home_httpd);
 626                         continue;
 627                 }
 628
 629                 if (ch == 'A' || ch == 'D') {
 630                         Htaccess_IP *pip;
 631
 632                         if (*after_colon == '*') {
 633                                 if (ch == 'D') {
 634                                         /* memorize "deny all" */
 635                                         flg_deny_all = 1;
 636                                 }
 637                                 /* skip assumed "A:*", it is a default anyway */
 638                                 continue;
 639                         }
 640                         /* store "allow/deny IP/mask" line */
 641                         pip = xzalloc(sizeof(*pip));
 642                         if (scan_ip_mask(after_colon, &pip->ip, &pip->mask)) {
 643                                 /* IP{/mask} syntax error detected, protect all */
 644                                 ch = 'D';
 645                                 pip->mask = 0;
 646                         }
 647                         pip->allow_deny = ch;
 648                         if (ch == 'D') {
 649                                 /* Deny:from_IP - prepend */
 650                                 pip->next = ip_a_d;
 651                                 ip_a_d = pip;
 652                         } else {
 653                                 /* A:from_IP - append (thus all D's precedes A's) */
 654                                 Htaccess_IP *prev_IP = ip_a_d;
 655                                 if (prev_IP == NULL) {
 656                                         ip_a_d = pip;
 657                                 } else {
 658                                         while (prev_IP->next)
 659                                                 prev_IP = prev_IP->next;
 660                                         prev_IP->next = pip;
 661                                 }
 662                         }
 663                         continue;
 664                 }
 665
 666 #if ENABLE_FEATURE_HTTPD_ERROR_PAGES
 667                 if (flag == FIRST_PARSE && ch == 'E') {
 668                         unsigned i;
 669                         int status = atoi(buf + 1); /* error status code */
 670
 671                         if (status < HTTP_CONTINUE) {
 672                                 goto config_error;
 673                         }
 674                         /* then error page; find matching status */
 675                         for (i = 0; i < ARRAY_SIZE(http_response_type); i++) {
 676                                 if (http_response_type[i] == status) {
 677                                         /* We chdir to home_httpd, thus no need to
 678                                          * concat_path_file(home_httpd, after_colon)
 679                                          * here */
 680                                         http_error_page[i] = xstrdup(after_colon);
 681                                         break;
 682                                 }
 683                         }
 684                         continue;
 685                 }
 686 #endif
 687
 688 #if ENABLE_FEATURE_HTTPD_PROXY
 689                 if (flag == FIRST_PARSE && ch == 'P') {
 690                         /* P:/url:[http://]hostname[:port]/new/path */
 691                         char *url_from, *host_port, *url_to;
 692                         Htaccess_Proxy *proxy_entry;
 693
 694                         url_from = after_colon;
 695                         host_port = strchr(after_colon, ':');
 696                         if (host_port == NULL) {
 697                                 goto config_error;
 698                         }
 699                         *host_port++ = '\0';
 700                         if (strncmp(host_port, "http://", 7) == 0)
 701                                 host_port += 7;
 702                         if (*host_port == '\0') {
 703                                 goto config_error;
 704                         }
 705                         url_to = strchr(host_port, '/');
 706                         if (url_to == NULL) {
 707                                 goto config_error;
 708                         }
 709                         *url_to = '\0';
 710                         proxy_entry = xzalloc(sizeof(*proxy_entry));
 711                         proxy_entry->url_from = xstrdup(url_from);
 712                         proxy_entry->host_port = xstrdup(host_port);
 713                         *url_to = '/';
 714                         proxy_entry->url_to = xstrdup(url_to);
 715                         proxy_entry->next = proxy;
 716                         proxy = proxy_entry;
 717                         continue;
 718                 }
 719 #endif
 720                 /* the rest of directives are non-alphabetic,
 721                  * must avoid using "toupper'ed" ch */
 722                 ch = buf[0];
 723
 724                 if (ch == '.' /* ".ext:mime/type" */
 725 #if ENABLE_FEATURE_HTTPD_CONFIG_WITH_SCRIPT_INTERPR
 726                  || (ch == '*' && buf[1] == '.') /* "*.php:/path/php" */
 727 #endif
 728                 ) {
 729                         char *p;
 730                         Htaccess *cur;
 731
 732                         cur = xzalloc(sizeof(*cur) /* includes space for NUL */ + strlen_buf);
 733                         strcpy(cur->before_colon, buf);
 734                         p = cur->before_colon + (after_colon - buf);
 735                         p[-1] = '\0';
 736                         cur->after_colon = p;
 737                         if (ch == '.') {
 738                                 /* .mime line: prepend to mime_a list */
 739                                 cur->next = mime_a;
 740                                 mime_a = cur;
 741                         }
 742 #if ENABLE_FEATURE_HTTPD_CONFIG_WITH_SCRIPT_INTERPR
 743                         else {
 744                                 /* script interpreter line: prepend to script_i list */
 745                                 cur->next = script_i;
 746                                 script_i = cur;
 747                         }
 748 #endif
 749                         continue;
 750                 }
 751
 752 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
 753                 if (ch == '/') { /* "/file:user:pass" */
 754                         char *p;
 755                         Htaccess *cur;
 756                         unsigned file_len;
 757
 758                         /* note: path is "" unless we are in SUBDIR parse,
 759                          * otherwise it does NOT start with "/" */
 760                         cur = xzalloc(sizeof(*cur) /* includes space for NUL */
 761                                 + 1 + strlen(path)
 762                                 + strlen_buf
 763                                 );
 764                         /* form "/path/file" */
 765                         sprintf(cur->before_colon, "/%s%.*s",
 766                                 path,
 767                                 (int) (after_colon - buf - 1), /* includes "/", but not ":" */
 768                                 buf);
 769                         /* canonicalize it */
 770                         p = bb_simplify_abs_path_inplace(cur->before_colon);
 771                         file_len = p - cur->before_colon;
 772                         /* add "user:pass" after NUL */
 773                         strcpy(++p, after_colon);
 774                         cur->after_colon = p;
 775
 776                         /* insert cur into g_auth */
 777                         /* g_auth is sorted by decreased filename length */
 778                         {
 779                                 Htaccess *auth, **authp;
 780
 781                                 authp = &g_auth;
 782                                 while ((auth = *authp) != NULL) {
 783                                         if (file_len >= strlen(auth->before_colon)) {
 784                                                 /* insert cur before auth */
 785                                                 cur->next = auth;
 786                                                 break;
 787                                         }
 788                                         authp = &auth->next;
 789                                 }
 790                                 *authp = cur;
 791                         }
 792                         continue;
 793                 }
 794 #endif /* BASIC_AUTH */
 795
 796                 /* the line is not recognized */
 797  config_error:
 798                 bb_error_msg("config error '%s' in '%s'", buf, filename);
 799         } /* while (fgets) */
 800
 801         fclose(f);
 802 }
 803
 804 #if ENABLE_FEATURE_HTTPD_ENCODE_URL_STR
 805 /*
 806  * Given a string, html-encode special characters.
 807  * This is used for the -e command line option to provide an easy way
 808  * for scripts to encode result data without confusing browsers.  The
 809  * returned string pointer is memory allocated by malloc().
 810  *
 811  * Returns a pointer to the encoded string (malloced).
 812  */
 813 static char *encodeString(const char *string)
 814 {
 815         /* take the simple route and encode everything */
 816         /* could possibly scan once to get length.     */
 817         int len = strlen(string);
 818         char *out = xmalloc(len * 6 + 1);
 819         char *p = out;
 820         char ch;
 821
 822         while ((ch = *string++) != '\0') {
 823                 /* very simple check for what to encode */
 824                 if (isalnum(ch))
 825                         *p++ = ch;
 826                 else
 827                         p += sprintf(p, "&#%d;", (unsigned char) ch);
 828         }
 829         *p = '\0';
 830         return out;
 831 }
 832 #endif
 833
 834 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
 835 /*
 836  * Decode a base64 data stream as per rfc1521.
 837  * Note that the rfc states that non base64 chars are to be ignored.
 838  * Since the decode always results in a shorter size than the input,
 839  * it is OK to pass the input arg as an output arg.
 840  * Parameter: a pointer to a base64 encoded string.
 841  * Decoded data is stored in-place.
 842  */
 843 static void decodeBase64(char *Data)
 844 {
 845         const unsigned char *in = (const unsigned char *)Data;
 846         /* The decoded size will be at most 3/4 the size of the encoded */
 847         unsigned ch = 0;
 848         int i = 0;
 849
 850         while (*in) {
 851                 int t = *in++;
 852
 853                 if (t >= '0' && t <= '9')
 854                         t = t - '0' + 52;
 855                 else if (t >= 'A' && t <= 'Z')
 856                         t = t - 'A';
 857                 else if (t >= 'a' && t <= 'z')
 858                         t = t - 'a' + 26;
 859                 else if (t == '+')
 860                         t = 62;
 861                 else if (t == '/')
 862                         t = 63;
 863                 else if (t == '=')
 864                         t = 0;
 865                 else
 866                         continue;
 867
 868                 ch = (ch << 6) | t;
 869                 i++;
 870                 if (i == 4) {
 871                         *Data++ = (char) (ch >> 16);
 872                         *Data++ = (char) (ch >> 8);
 873                         *Data++ = (char) ch;
 874                         i = 0;
 875                 }
 876         }
 877         *Data = '\0';
 878 }
 879 #endif
 880
 881 /*
 882  * Create a listen server socket on the designated port.
 883  */
 884 static int openServer(void)
 885 {
 886         unsigned n = bb_strtou(bind_addr_or_port, NULL, 10);
 887         if (!errno && n && n <= 0xffff)
 888                 n = create_and_bind_stream_or_die(NULL, n);
 889         else
 890                 n = create_and_bind_stream_or_die(bind_addr_or_port, 80);
 891         xlisten(n, 9);
 892         return n;
 893 }
 894
 895 /*
 896  * Log the connection closure and exit.
 897  */
 898 static void log_and_exit(void) NORETURN;
 899 static void log_and_exit(void)
 900 {
 901         /* Paranoia. IE said to be buggy. It may send some extra data
 902          * or be confused by us just exiting without SHUT_WR. Oh well. */
 903         shutdown(1, SHUT_WR);
 904         /* Why??
 905         (this also messes up stdin when user runs httpd -i from terminal)
 906         ndelay_on(0);
 907         while (read(STDIN_FILENO, iobuf, IOBUF_SIZE) > 0)
 908                 continue;
 909         */
 910
 911         if (verbose > 2)
 912                 bb_error_msg("closed");
 913         _exit(xfunc_error_retval);
 914 }
 915
 916 /*
 917  * Create and send HTTP response headers.
 918  * The arguments are combined and sent as one write operation.  Note that
 919  * IE will puke big-time if the headers are not sent in one packet and the
 920  * second packet is delayed for any reason.
 921  * responseNum - the result code to send.
 922  */
 923 static void send_headers(int responseNum)
 924 {
 925         static const char RFC1123FMT[] ALIGN1 = "%a, %d %b %Y %H:%M:%S GMT";
 926
 927         const char *responseString = "";
 928         const char *infoString = NULL;
 929         const char *mime_type;
 930 #if ENABLE_FEATURE_HTTPD_ERROR_PAGES
 931         const char *error_page = NULL;
 932 #endif
 933         unsigned i;
 934         time_t timer = time(NULL);
 935         char tmp_str[80];
 936         int len;
 937
 938         for (i = 0; i < ARRAY_SIZE(http_response_type); i++) {
 939                 if (http_response_type[i] == responseNum) {
 940                         responseString = http_response[i].name;
 941                         infoString = http_response[i].info;
 942 #if ENABLE_FEATURE_HTTPD_ERROR_PAGES
 943                         error_page = http_error_page[i];
 944 #endif
 945                         break;
 946                 }
 947         }
 948         /* error message is HTML */
 949         mime_type = responseNum == HTTP_OK ?
 950                                 found_mime_type : "text/html";
 951
 952         if (verbose)
 953                 bb_error_msg("response:%u", responseNum);
 954
 955         /* emit the current date */
 956         strftime(tmp_str, sizeof(tmp_str), RFC1123FMT, gmtime(&timer));
 957         len = sprintf(iobuf,
 958                         "HTTP/1.0 %d %s\r\nContent-type: %s\r\n"
 959                         "Date: %s\r\nConnection: close\r\n",
 960                         responseNum, responseString, mime_type, tmp_str);
 961
 962 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
 963         if (responseNum == HTTP_UNAUTHORIZED) {
 964                 len += sprintf(iobuf + len,
 965                                 "WWW-Authenticate: Basic realm=\"%s\"\r\n",
 966                                 g_realm);
 967         }
 968 #endif
 969         if (responseNum == HTTP_MOVED_TEMPORARILY) {
 970                 len += sprintf(iobuf + len, "Location: %s/%s%s\r\n",
 971                                 found_moved_temporarily,
 972                                 (g_query ? "?" : ""),
 973                                 (g_query ? g_query : ""));
 974         }
 975
 976 #if ENABLE_FEATURE_HTTPD_ERROR_PAGES
 977         if (error_page && access(error_page, R_OK) == 0) {
 978                 strcat(iobuf, "\r\n");
 979                 len += 2;
 980
 981                 if (DEBUG)
 982                         fprintf(stderr, "headers: '%s'\n", iobuf);
 983                 full_write(STDOUT_FILENO, iobuf, len);
 984                 if (DEBUG)
 985                         fprintf(stderr, "writing error page: '%s'\n", error_page);
 986                 return send_file_and_exit(error_page, SEND_BODY);
 987         }
 988 #endif
 989
 990         if (file_size != -1) {    /* file */
 991                 strftime(tmp_str, sizeof(tmp_str), RFC1123FMT, gmtime(&last_mod));
 992 #if ENABLE_FEATURE_HTTPD_RANGES
 993                 if (responseNum == HTTP_PARTIAL_CONTENT) {
 994                         len += sprintf(iobuf + len, "Content-Range: bytes %"OFF_FMT"u-%"OFF_FMT"u/%"OFF_FMT"u\r\n",
 995                                         range_start,
 996                                         range_end,
 997                                         file_size);
 998                         file_size = range_end - range_start + 1;
 999                 }
1000 #endif
1001                 len += sprintf(iobuf + len,
1002 #if ENABLE_FEATURE_HTTPD_RANGES
1003                         "Accept-Ranges: bytes\r\n"
1004 #endif
1005                         "Last-Modified: %s\r\n%s %"OFF_FMT"u\r\n",
1006                                 tmp_str,
1007                                 content_gzip ? "Transfer-length:" : "Content-length:",
1008                                 file_size
1009                 );
1010         }
1011
1012         if (content_gzip)
1013                 len += sprintf(iobuf + len, "Content-Encoding: gzip\r\n");
1014
1015         iobuf[len++] = '\r';
1016         iobuf[len++] = '\n';
1017         if (infoString) {
1018                 len += sprintf(iobuf + len,
1019                                 "<HTML><HEAD><TITLE>%d %s</TITLE></HEAD>\n"
1020                                 "<BODY><H1>%d %s</H1>\n%s\n</BODY></HTML>\n",
1021                                 responseNum, responseString,
1022                                 responseNum, responseString, infoString);
1023         }
1024         if (DEBUG)
1025                 fprintf(stderr, "headers: '%s'\n", iobuf);
1026         if (full_write(STDOUT_FILENO, iobuf, len) != len) {
1027                 if (verbose > 1)
1028                         bb_perror_msg("error");
1029                 log_and_exit();
1030         }
1031 }
1032
1033 static void send_headers_and_exit(int responseNum) NORETURN;
1034 static void send_headers_and_exit(int responseNum)
1035 {
1036         IF_FEATURE_HTTPD_GZIP(content_gzip = 0;)
1037         send_headers(responseNum);
1038         log_and_exit();
1039 }
1040
1041 /*
1042  * Read from the socket until '\n' or EOF. '\r' chars are removed.
1043  * '\n' is replaced with NUL.
1044  * Return number of characters read or 0 if nothing is read
1045  * ('\r' and '\n' are not counted).
1046  * Data is returned in iobuf.
1047  */
1048 static int get_line(void)
1049 {
1050         int count = 0;
1051         char c;
1052
1053         alarm(HEADER_READ_TIMEOUT);
1054         while (1) {
1055                 if (hdr_cnt <= 0) {
1056                         hdr_cnt = safe_read(STDIN_FILENO, hdr_buf, sizeof(hdr_buf));
1057                         if (hdr_cnt <= 0)
1058                                 break;
1059                         hdr_ptr = hdr_buf;
1060                 }
1061                 iobuf[count] = c = *hdr_ptr++;
1062                 hdr_cnt--;
1063
1064                 if (c == '\r')
1065                         continue;
1066                 if (c == '\n') {
1067                         iobuf[count] = '\0';
1068                         break;
1069                 }
1070                 if (count < (IOBUF_SIZE - 1))      /* check overflow */
1071                         count++;
1072         }
1073         return count;
1074 }
1075
1076 #if ENABLE_FEATURE_HTTPD_CGI || ENABLE_FEATURE_HTTPD_PROXY
1077
1078 /* gcc 4.2.1 fares better with NOINLINE */
1079 static NOINLINE void cgi_io_loop_and_exit(int fromCgi_rd, int toCgi_wr, int post_len) NORETURN;
1080 static NOINLINE void cgi_io_loop_and_exit(int fromCgi_rd, int toCgi_wr, int post_len)
1081 {
1082         enum { FROM_CGI = 1, TO_CGI = 2 }; /* indexes in pfd[] */
1083         struct pollfd pfd[3];
1084         int out_cnt; /* we buffer a bit of initial CGI output */
1085         int count;
1086
1087         /* iobuf is used for CGI -> network data,
1088          * hdr_buf is for network -> CGI data (POSTDATA) */
1089
1090         /* If CGI dies, we still want to correctly finish reading its output
1091          * and send it to the peer. So please no SIGPIPEs! */
1092         signal(SIGPIPE, SIG_IGN);
1093
1094         // We inconsistently handle a case when more POSTDATA from network
1095         // is coming than we expected. We may give *some part* of that
1096         // extra data to CGI.
1097
1098         //if (hdr_cnt > post_len) {
1099         //      /* We got more POSTDATA from network than we expected */
1100         //      hdr_cnt = post_len;
1101         //}
1102         post_len -= hdr_cnt;
1103         /* post_len - number of POST bytes not yet read from network */
1104
1105         /* NB: breaking out of this loop jumps to log_and_exit() */
1106         out_cnt = 0;
1107         pfd[FROM_CGI].fd = fromCgi_rd;
1108         pfd[FROM_CGI].events = POLLIN;
1109         pfd[TO_CGI].fd = toCgi_wr;
1110         while (1) {
1111                 /* Note: even pfd[0].events == 0 won't prevent
1112                  * revents == POLLHUP|POLLERR reports from closed stdin.
1113                  * Setting fd to -1 works: */
1114                 pfd[0].fd = -1;
1115                 pfd[0].events = POLLIN;
1116                 pfd[0].revents = 0; /* probably not needed, paranoia */
1117
1118                 /* We always poll this fd, thus kernel always sets revents: */
1119                 /*pfd[FROM_CGI].events = POLLIN; - moved out of loop */
1120                 /*pfd[FROM_CGI].revents = 0; - not needed */
1121
1122                 /* gcc-4.8.0 still doesnt fill two shorts with one insn :( */
1123                 /* http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47059 */
1124                 /* hopefully one day it will... */
1125                 pfd[TO_CGI].events = POLLOUT;
1126                 pfd[TO_CGI].revents = 0; /* needed! */
1127
1128                 if (toCgi_wr && hdr_cnt <= 0) {
1129                         if (post_len > 0) {
1130                                 /* Expect more POST data from network */
1131                                 pfd[0].fd = 0;
1132                         } else {
1133                                 /* post_len <= 0 && hdr_cnt <= 0:
1134                                  * no more POST data to CGI,
1135                                  * let CGI see EOF on CGI's stdin */
1136                                 if (toCgi_wr != fromCgi_rd)
1137                                         close(toCgi_wr);
1138                                 toCgi_wr = 0;
1139                         }
1140                 }
1141
1142                 /* Now wait on the set of sockets */
1143                 count = safe_poll(pfd, hdr_cnt > 0 ? TO_CGI+1 : FROM_CGI+1, -1);
1144                 if (count <= 0) {
1145 #if 0
1146                         if (safe_waitpid(pid, &status, WNOHANG) <= 0) {
1147                                 /* Weird. CGI didn't exit and no fd's
1148                                  * are ready, yet poll returned?! */
1149                                 continue;
1150                         }
1151                         if (DEBUG && WIFEXITED(status))
1152                                 bb_error_msg("CGI exited, status=%d", WEXITSTATUS(status));
1153                         if (DEBUG && WIFSIGNALED(status))
1154                                 bb_error_msg("CGI killed, signal=%d", WTERMSIG(status));
1155 #endif
1156                         break;
1157                 }
1158
1159                 if (pfd[TO_CGI].revents) {
1160                         /* hdr_cnt > 0 here due to the way poll() called */
1161                         /* Have data from peer and can write to CGI */
1162                         count = safe_write(toCgi_wr, hdr_ptr, hdr_cnt);
1163                         /* Doesn't happen, we dont use nonblocking IO here
1164                          *if (count < 0 && errno == EAGAIN) {
1165                          *      ...
1166                          *} else */
1167                         if (count > 0) {
1168                                 hdr_ptr += count;
1169                                 hdr_cnt -= count;
1170                         } else {
1171                                 /* EOF/broken pipe to CGI, stop piping POST data */
1172                                 hdr_cnt = post_len = 0;
1173                         }
1174                 }
1175
1176                 if (pfd[0].revents) {
1177                         /* post_len > 0 && hdr_cnt == 0 here */
1178                         /* We expect data, prev data portion is eaten by CGI
1179                          * and there *is* data to read from the peer
1180                          * (POSTDATA) */
1181                         //count = post_len > (int)sizeof(hdr_buf) ? (int)sizeof(hdr_buf) : post_len;
1182                         //count = safe_read(STDIN_FILENO, hdr_buf, count);
1183                         count = safe_read(STDIN_FILENO, hdr_buf, sizeof(hdr_buf));
1184                         if (count > 0) {
1185                                 hdr_cnt = count;
1186                                 hdr_ptr = hdr_buf;
1187                                 post_len -= count;
1188                         } else {
1189                                 /* no more POST data can be read */
1190                                 post_len = 0;
1191                         }
1192                 }
1193
1194                 if (pfd[FROM_CGI].revents) {
1195                         /* There is something to read from CGI */
1196                         char *rbuf = iobuf;
1197
1198                         /* Are we still buffering CGI output? */
1199                         if (out_cnt >= 0) {
1200                                 /* HTTP_200[] has single "\r\n" at the end.
1201                                  * According to http://hoohoo.ncsa.uiuc.edu/cgi/out.html,
1202                                  * CGI scripts MUST send their own header terminated by
1203                                  * empty line, then data. That's why we have only one
1204                                  * <cr><lf> pair here. We will output "200 OK" line
1205                                  * if needed, but CGI still has to provide blank line
1206                                  * between header and body */
1207
1208                                 /* Must use safe_read, not full_read, because
1209                                  * CGI may output a few first bytes and then wait
1210                                  * for POSTDATA without closing stdout.
1211                                  * With full_read we may wait here forever. */
1212                                 count = safe_read(fromCgi_rd, rbuf + out_cnt, PIPE_BUF - 8);
1213                                 if (count <= 0) {
1214                                         /* eof (or error) and there was no "HTTP",
1215                                          * so write it, then write received data */
1216                                         if (out_cnt) {
1217                                                 full_write(STDOUT_FILENO, HTTP_200, sizeof(HTTP_200)-1);
1218                                                 full_write(STDOUT_FILENO, rbuf, out_cnt);
1219                                         }
1220                                         break; /* CGI stdout is closed, exiting */
1221                                 }
1222                                 out_cnt += count;
1223                                 count = 0;
1224                                 /* "Status" header format is: "Status: 302 Redirected\r\n" */
1225                                 if (out_cnt >= 8 && memcmp(rbuf, "Status: ", 8) == 0) {
1226                                         /* send "HTTP/1.0 " */
1227                                         if (full_write(STDOUT_FILENO, HTTP_200, 9) != 9)
1228                                                 break;
1229                                         rbuf += 8; /* skip "Status: " */
1230                                         count = out_cnt - 8;
1231                                         out_cnt = -1; /* buffering off */
1232                                 } else if (out_cnt >= 4) {
1233                                         /* Did CGI add "HTTP"? */
1234                                         if (memcmp(rbuf, HTTP_200, 4) != 0) {
1235                                                 /* there is no "HTTP", do it ourself */
1236                                                 if (full_write(STDOUT_FILENO, HTTP_200, sizeof(HTTP_200)-1) != sizeof(HTTP_200)-1)
1237                                                         break;
1238                                         }
1239                                         /* Commented out:
1240                                         if (!strstr(rbuf, "ontent-")) {
1241                                                 full_write(s, "Content-type: text/plain\r\n\r\n", 28);
1242                                         }
1243                                          * Counter-example of valid CGI without Content-type:
1244                                          * echo -en "HTTP/1.0 302 Found\r\n"
1245                                          * echo -en "Location: http://www.busybox.net\r\n"
1246                                          * echo -en "\r\n"
1247                                          */
1248                                         count = out_cnt;
1249                                         out_cnt = -1; /* buffering off */
1250                                 }
1251                         } else {
1252                                 count = safe_read(fromCgi_rd, rbuf, PIPE_BUF);
1253                                 if (count <= 0)
1254                                         break;  /* eof (or error) */
1255                         }
1256                         if (full_write(STDOUT_FILENO, rbuf, count) != count)
1257                                 break;
1258                         if (DEBUG)
1259                                 fprintf(stderr, "cgi read %d bytes: '%.*s'\n", count, count, rbuf);
1260                 } /* if (pfd[FROM_CGI].revents) */
1261         } /* while (1) */
1262         log_and_exit();
1263 }
1264 #endif
1265
1266 #if ENABLE_FEATURE_HTTPD_CGI
1267
1268 static void setenv1(const char *name, const char *value)
1269 {
1270         setenv(name, value ? value : "", 1);
1271 }
1272
1273 /*
1274  * Spawn CGI script, forward CGI's stdin/out <=> network
1275  *
1276  * Environment variables are set up and the script is invoked with pipes
1277  * for stdin/stdout.  If a POST is being done the script is fed the POST
1278  * data in addition to setting the QUERY_STRING variable (for GETs or POSTs).
1279  *
1280  * Parameters:
1281  * const char *url              The requested URL (with leading /).
1282  * const char *orig_uri         The original URI before rewriting (if any)
1283  * int post_len                 Length of the POST body.
1284  * const char *cookie           For set HTTP_COOKIE.
1285  * const char *content_type     For set CONTENT_TYPE.
1286  */
1287 static void send_cgi_and_exit(
1288                 const char *url,
1289                 const char *orig_uri,
1290                 const char *request,
1291                 int post_len,
1292                 const char *cookie,
1293                 const char *content_type) NORETURN;
1294 static void send_cgi_and_exit(
1295                 const char *url,
1296                 const char *orig_uri,
1297                 const char *request,
1298                 int post_len,
1299                 const char *cookie,
1300                 const char *content_type)
1301 {
1302         struct fd_pair fromCgi;  /* CGI -> httpd pipe */
1303         struct fd_pair toCgi;    /* httpd -> CGI pipe */
1304         char *script, *last_slash;
1305         int pid;
1306
1307         /* Make a copy. NB: caller guarantees:
1308          * url[0] == '/', url[1] != '/' */
1309         url = xstrdup(url);
1310
1311         /*
1312          * We are mucking with environment _first_ and then vfork/exec,
1313          * this allows us to use vfork safely. Parent doesn't care about
1314          * these environment changes anyway.
1315          */
1316
1317         /* Check for [dirs/]script.cgi/PATH_INFO */
1318         last_slash = script = (char*)url;
1319         while ((script = strchr(script + 1, '/')) != NULL) {
1320                 int dir;
1321                 *script = '\0';
1322                 dir = is_directory(url + 1, /*followlinks:*/ 1);
1323                 *script = '/';
1324                 if (!dir) {
1325                         /* not directory, found script.cgi/PATH_INFO */
1326                         break;
1327                 }
1328                 /* is directory, find next '/' */
1329                 last_slash = script;
1330         }
1331         setenv1("PATH_INFO", script);   /* set to /PATH_INFO or "" */
1332         setenv1("REQUEST_METHOD", request);
1333         if (g_query) {
1334                 putenv(xasprintf("%s=%s?%s", "REQUEST_URI", orig_uri, g_query));
1335         } else {
1336                 setenv1("REQUEST_URI", orig_uri);
1337         }
1338         if (script != NULL)
1339                 *script = '\0';         /* cut off /PATH_INFO */
1340
1341         /* SCRIPT_FILENAME is required by PHP in CGI mode */
1342         if (home_httpd[0] == '/') {
1343                 char *fullpath = concat_path_file(home_httpd, url);
1344                 setenv1("SCRIPT_FILENAME", fullpath);
1345         }
1346         /* set SCRIPT_NAME as full path: /cgi-bin/dirs/script.cgi */
1347         setenv1("SCRIPT_NAME", url);
1348         /* http://hoohoo.ncsa.uiuc.edu/cgi/env.html:
1349          * QUERY_STRING: The information which follows the ? in the URL
1350          * which referenced this script. This is the query information.
1351          * It should not be decoded in any fashion. This variable
1352          * should always be set when there is query information,
1353          * regardless of command line decoding. */
1354         /* (Older versions of bbox seem to do some decoding) */
1355         setenv1("QUERY_STRING", g_query);
1356         putenv((char*)"SERVER_SOFTWARE=busybox httpd/"BB_VER);
1357         putenv((char*)"SERVER_PROTOCOL=HTTP/1.0");
1358         putenv((char*)"GATEWAY_INTERFACE=CGI/1.1");
1359         /* Having _separate_ variables for IP and port defeats
1360          * the purpose of having socket abstraction. Which "port"
1361          * are you using on Unix domain socket?
1362          * IOW - REMOTE_PEER="1.2.3.4:56" makes much more sense.
1363          * Oh well... */
1364         {
1365                 char *p = rmt_ip_str ? rmt_ip_str : (char*)"";
1366                 char *cp = strrchr(p, ':');
1367                 if (ENABLE_FEATURE_IPV6 && cp && strchr(cp, ']'))
1368                         cp = NULL;
1369                 if (cp) *cp = '\0'; /* delete :PORT */
1370                 setenv1("REMOTE_ADDR", p);
1371                 if (cp) {
1372                         *cp = ':';
1373 #if ENABLE_FEATURE_HTTPD_SET_REMOTE_PORT_TO_ENV
1374                         setenv1("REMOTE_PORT", cp + 1);
1375 #endif
1376                 }
1377         }
1378         setenv1("HTTP_USER_AGENT", user_agent);
1379         if (http_accept)
1380                 setenv1("HTTP_ACCEPT", http_accept);
1381         if (http_accept_language)
1382                 setenv1("HTTP_ACCEPT_LANGUAGE", http_accept_language);
1383         if (post_len)
1384                 putenv(xasprintf("CONTENT_LENGTH=%d", post_len));
1385         if (cookie)
1386                 setenv1("HTTP_COOKIE", cookie);
1387         if (content_type)
1388                 setenv1("CONTENT_TYPE", content_type);
1389 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
1390         if (remoteuser) {
1391                 setenv1("REMOTE_USER", remoteuser);
1392                 putenv((char*)"AUTH_TYPE=Basic");
1393         }
1394 #endif
1395         if (referer)
1396                 setenv1("HTTP_REFERER", referer);
1397         setenv1("HTTP_HOST", host); /* set to "" if NULL */
1398         /* setenv1("SERVER_NAME", safe_gethostname()); - don't do this,
1399          * just run "env SERVER_NAME=xyz httpd ..." instead */
1400
1401         xpiped_pair(fromCgi);
1402         xpiped_pair(toCgi);
1403
1404         pid = vfork();
1405         if (pid < 0) {
1406                 /* TODO: log perror? */
1407                 log_and_exit();
1408         }
1409
1410         if (pid == 0) {
1411                 /* Child process */
1412                 char *argv[3];
1413
1414                 xfunc_error_retval = 242;
1415
1416                 /* NB: close _first_, then move fds! */
1417                 close(toCgi.wr);
1418                 close(fromCgi.rd);
1419                 xmove_fd(toCgi.rd, 0);  /* replace stdin with the pipe */
1420                 xmove_fd(fromCgi.wr, 1);  /* replace stdout with the pipe */
1421                 /* User seeing stderr output can be a security problem.
1422                  * If CGI really wants that, it can always do dup itself. */
1423                 /* dup2(1, 2); */
1424
1425                 /* Chdiring to script's dir */
1426                 script = last_slash;
1427                 if (script != url) { /* paranoia */
1428                         *script = '\0';
1429                         if (chdir(url + 1) != 0) {
1430                                 bb_perror_msg("can't change directory to '%s'", url + 1);
1431                                 goto error_execing_cgi;
1432                         }
1433                         // not needed: *script = '/';
1434                 }
1435                 script++;
1436
1437                 /* set argv[0] to name without path */
1438                 argv[0] = script;
1439                 argv[1] = NULL;
1440
1441 #if ENABLE_FEATURE_HTTPD_CONFIG_WITH_SCRIPT_INTERPR
1442                 {
1443                         char *suffix = strrchr(script, '.');
1444
1445                         if (suffix) {
1446                                 Htaccess *cur;
1447                                 for (cur = script_i; cur; cur = cur->next) {
1448                                         if (strcmp(cur->before_colon + 1, suffix) == 0) {
1449                                                 /* found interpreter name */
1450                                                 argv[0] = cur->after_colon;
1451                                                 argv[1] = script;
1452                                                 argv[2] = NULL;
1453                                                 break;
1454                                         }
1455                                 }
1456                         }
1457                 }
1458 #endif
1459                 /* restore default signal dispositions for CGI process */
1460                 bb_signals(0
1461                         | (1 << SIGCHLD)
1462                         | (1 << SIGPIPE)
1463                         | (1 << SIGHUP)
1464                         , SIG_DFL);
1465
1466                 /* _NOT_ execvp. We do not search PATH. argv[0] is a filename
1467                  * without any dir components and will only match a file
1468                  * in the current directory */
1469                 execv(argv[0], argv);
1470                 if (verbose)
1471                         bb_perror_msg("can't execute '%s'", argv[0]);
1472  error_execing_cgi:
1473                 /* send to stdout
1474                  * (we are CGI here, our stdout is pumped to the net) */
1475                 send_headers_and_exit(HTTP_NOT_FOUND);
1476         } /* end child */
1477
1478         /* Parent process */
1479
1480         /* Restore variables possibly changed by child */
1481         xfunc_error_retval = 0;
1482
1483         /* Pump data */
1484         close(fromCgi.wr);
1485         close(toCgi.rd);
1486         cgi_io_loop_and_exit(fromCgi.rd, toCgi.wr, post_len);
1487 }
1488
1489 #endif          /* FEATURE_HTTPD_CGI */
1490
1491 /*
1492  * Send a file response to a HTTP request, and exit
1493  *
1494  * Parameters:
1495  * const char *url  The requested URL (with leading /).
1496  * what             What to send (headers/body/both).
1497  */
1498 static NOINLINE void send_file_and_exit(const char *url, int what)
1499 {
1500         char *suffix;
1501         int fd;
1502         ssize_t count;
1503
1504         if (content_gzip) {
1505                 /* does <url>.gz exist? Then use it instead */
1506                 char *gzurl = xasprintf("%s.gz", url);
1507                 fd = open(gzurl, O_RDONLY);
1508                 free(gzurl);
1509                 if (fd != -1) {
1510                         struct stat sb;
1511                         fstat(fd, &sb);
1512                         file_size = sb.st_size;
1513                         last_mod = sb.st_mtime;
1514                 } else {
1515                         IF_FEATURE_HTTPD_GZIP(content_gzip = 0;)
1516                         fd = open(url, O_RDONLY);
1517                 }
1518         } else {
1519                 fd = open(url, O_RDONLY);
1520         }
1521         if (fd < 0) {
1522                 if (DEBUG)
1523                         bb_perror_msg("can't open '%s'", url);
1524                 /* Error pages are sent by using send_file_and_exit(SEND_BODY).
1525                  * IOW: it is unsafe to call send_headers_and_exit
1526                  * if what is SEND_BODY! Can recurse! */
1527                 if (what != SEND_BODY)
1528                         send_headers_and_exit(HTTP_NOT_FOUND);
1529                 log_and_exit();
1530         }
1531         /* If you want to know about EPIPE below
1532          * (happens if you abort downloads from local httpd): */
1533         signal(SIGPIPE, SIG_IGN);
1534
1535         /* If not found, default is "application/octet-stream" */
1536         found_mime_type = "application/octet-stream";
1537         suffix = strrchr(url, '.');
1538         if (suffix) {
1539                 static const char suffixTable[] ALIGN1 =
1540                         /* Shorter suffix must be first:
1541                          * ".html.htm" will fail for ".htm"
1542                          */
1543                         ".txt.h.c.cc.cpp\0" "text/plain\0"
1544                         /* .htm line must be after .h line */
1545                         ".htm.html\0" "text/html\0"
1546                         ".jpg.jpeg\0" "image/jpeg\0"
1547                         ".gif\0"      "image/gif\0"
1548                         ".png\0"      "image/png\0"
1549                         /* .css line must be after .c line */
1550                         ".css\0"      "text/css\0"
1551                         ".wav\0"      "audio/wav\0"
1552                         ".avi\0"      "video/x-msvideo\0"
1553                         ".qt.mov\0"   "video/quicktime\0"
1554                         ".mpe.mpeg\0" "video/mpeg\0"
1555                         ".mid.midi\0" "audio/midi\0"
1556                         ".mp3\0"      "audio/mpeg\0"
1557 #if 0  /* unpopular */
1558                         ".au\0"       "audio/basic\0"
1559                         ".pac\0"      "application/x-ns-proxy-autoconfig\0"
1560                         ".vrml.wrl\0" "model/vrml\0"
1561 #endif
1562                         /* compiler adds another "\0" here */
1563                 ;
1564                 Htaccess *cur;
1565
1566                 /* Examine built-in table */
1567                 const char *table = suffixTable;
1568                 const char *table_next;
1569                 for (; *table; table = table_next) {
1570                         const char *try_suffix;
1571                         const char *mime_type;
1572                         mime_type  = table + strlen(table) + 1;
1573                         table_next = mime_type + strlen(mime_type) + 1;
1574                         try_suffix = strstr(table, suffix);
1575                         if (!try_suffix)
1576                                 continue;
1577                         try_suffix += strlen(suffix);
1578                         if (*try_suffix == '\0' || *try_suffix == '.') {
1579                                 found_mime_type = mime_type;
1580                                 break;
1581                         }
1582                         /* Example: strstr(table, ".av") != NULL, but it
1583                          * does not match ".avi" after all and we end up here.
1584                          * The table is arranged so that in this case we know
1585                          * that it can't match anything in the following lines,
1586                          * and we stop the search: */
1587                         break;
1588                 }
1589                 /* ...then user's table */
1590                 for (cur = mime_a; cur; cur = cur->next) {
1591                         if (strcmp(cur->before_colon, suffix) == 0) {
1592                                 found_mime_type = cur->after_colon;
1593                                 break;
1594                         }
1595                 }
1596         }
1597
1598         if (DEBUG)
1599                 bb_error_msg("sending file '%s' content-type: %s",
1600                         url, found_mime_type);
1601
1602 #if ENABLE_FEATURE_HTTPD_RANGES
1603         if (what == SEND_BODY /* err pages and ranges don't mix */
1604          || content_gzip /* we are sending compressed page: can't do ranges */  ///why?
1605         ) {
1606                 range_start = -1;
1607         }
1608         range_len = MAXINT(off_t);
1609         if (range_start >= 0) {
1610                 if (!range_end || range_end > file_size - 1) {
1611                         range_end = file_size - 1;
1612                 }
1613                 if (range_end < range_start
1614                  || lseek(fd, range_start, SEEK_SET) != range_start
1615                 ) {
1616                         lseek(fd, 0, SEEK_SET);
1617                         range_start = -1;
1618                 } else {
1619                         range_len = range_end - range_start + 1;
1620                         send_headers(HTTP_PARTIAL_CONTENT);
1621                         what = SEND_BODY;
1622                 }
1623         }
1624 #endif
1625         if (what & SEND_HEADERS)
1626                 send_headers(HTTP_OK);
1627 #if ENABLE_FEATURE_HTTPD_USE_SENDFILE
1628         {
1629                 off_t offset = range_start;
1630                 while (1) {
1631                         /* sz is rounded down to 64k */
1632                         ssize_t sz = MAXINT(ssize_t) - 0xffff;
1633                         IF_FEATURE_HTTPD_RANGES(if (sz > range_len) sz = range_len;)
1634                         count = sendfile(STDOUT_FILENO, fd, &offset, sz);
1635                         if (count < 0) {
1636                                 if (offset == range_start)
1637                                         break; /* fall back to read/write loop */
1638                                 goto fin;
1639                         }
1640                         IF_FEATURE_HTTPD_RANGES(range_len -= count;)
1641                         if (count == 0 || range_len == 0)
1642                                 log_and_exit();
1643                 }
1644         }
1645 #endif
1646         while ((count = safe_read(fd, iobuf, IOBUF_SIZE)) > 0) {
1647                 ssize_t n;
1648                 IF_FEATURE_HTTPD_RANGES(if (count > range_len) count = range_len;)
1649                 n = full_write(STDOUT_FILENO, iobuf, count);
1650                 if (count != n)
1651                         break;
1652                 IF_FEATURE_HTTPD_RANGES(range_len -= count;)
1653                 if (range_len == 0)
1654                         break;
1655         }
1656         if (count < 0) {
1657  IF_FEATURE_HTTPD_USE_SENDFILE(fin:)
1658                 if (verbose > 1)
1659                         bb_perror_msg("error");
1660         }
1661         log_and_exit();
1662 }
1663
1664 static int checkPermIP(void)
1665 {
1666         Htaccess_IP *cur;
1667
1668         for (cur = ip_a_d; cur; cur = cur->next) {
1669 #if DEBUG
1670                 fprintf(stderr,
1671                         "checkPermIP: '%s' ? '%u.%u.%u.%u/%u.%u.%u.%u'\n",
1672                         rmt_ip_str,
1673                         (unsigned char)(cur->ip >> 24),
1674                         (unsigned char)(cur->ip >> 16),
1675                         (unsigned char)(cur->ip >> 8),
1676                         (unsigned char)(cur->ip),
1677                         (unsigned char)(cur->mask >> 24),
1678                         (unsigned char)(cur->mask >> 16),
1679                         (unsigned char)(cur->mask >> 8),
1680                         (unsigned char)(cur->mask)
1681                 );
1682 #endif
1683                 if ((rmt_ip & cur->mask) == cur->ip)
1684                         return (cur->allow_deny == 'A'); /* A -> 1 */
1685         }
1686
1687         return !flg_deny_all; /* depends on whether we saw "D:*" */
1688 }
1689
1690 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
1691
1692 # if ENABLE_PAM
1693 struct pam_userinfo {
1694         const char *name;
1695         const char *pw;
1696 };
1697
1698 static int pam_talker(int num_msg,
1699                 const struct pam_message **msg,
1700                 struct pam_response **resp,
1701                 void *appdata_ptr)
1702 {
1703         int i;
1704         struct pam_userinfo *userinfo = (struct pam_userinfo *) appdata_ptr;
1705         struct pam_response *response;
1706
1707         if (!resp || !msg || !userinfo)
1708                 return PAM_CONV_ERR;
1709
1710         /* allocate memory to store response */
1711         response = xzalloc(num_msg * sizeof(*response));
1712
1713         /* copy values */
1714         for (i = 0; i < num_msg; i++) {
1715                 const char *s;
1716
1717                 switch (msg[i]->msg_style) {
1718                 case PAM_PROMPT_ECHO_ON:
1719                         s = userinfo->name;
1720                         break;
1721                 case PAM_PROMPT_ECHO_OFF:
1722                         s = userinfo->pw;
1723                         break;
1724                 case PAM_ERROR_MSG:
1725                 case PAM_TEXT_INFO:
1726                         s = "";
1727                         break;
1728                 default:
1729                         free(response);
1730                         return PAM_CONV_ERR;
1731                 }
1732                 response[i].resp = xstrdup(s);
1733                 if (PAM_SUCCESS != 0)
1734                         response[i].resp_retcode = PAM_SUCCESS;
1735         }
1736         *resp = response;
1737         return PAM_SUCCESS;
1738 }
1739 # endif
1740
1741 /*
1742  * Config file entries are of the form "/<path>:<user>:<passwd>".
1743  * If config file has no prefix match for path, access is allowed.
1744  *
1745  * path                 The file path
1746  * user_and_passwd      "user:passwd" to validate
1747  *
1748  * Returns 1 if user_and_passwd is OK.
1749  */
1750 static int check_user_passwd(const char *path, char *user_and_passwd)
1751 {
1752         Htaccess *cur;
1753         const char *prev = NULL;
1754
1755         for (cur = g_auth; cur; cur = cur->next) {
1756                 const char *dir_prefix;
1757                 size_t len;
1758                 int r;
1759
1760                 dir_prefix = cur->before_colon;
1761
1762                 /* WHY? */
1763                 /* If already saw a match, don't accept other different matches */
1764                 if (prev && strcmp(prev, dir_prefix) != 0)
1765                         continue;
1766
1767                 if (DEBUG)
1768                         fprintf(stderr, "checkPerm: '%s' ? '%s'\n", dir_prefix, user_and_passwd);
1769
1770                 /* If it's not a prefix match, continue searching */
1771                 len = strlen(dir_prefix);
1772                 if (len != 1 /* dir_prefix "/" matches all, don't need to check */
1773                  && (strncmp(dir_prefix, path, len) != 0
1774                     || (path[len] != '/' && path[len] != '\0')
1775                     )
1776                 ) {
1777                         continue;
1778                 }
1779
1780                 /* Path match found */
1781                 prev = dir_prefix;
1782
1783                 if (ENABLE_FEATURE_HTTPD_AUTH_MD5) {
1784                         char *colon_after_user;
1785                         const char *passwd;
1786 # if ENABLE_FEATURE_SHADOWPASSWDS && !ENABLE_PAM
1787                         char sp_buf[256];
1788 # endif
1789
1790                         colon_after_user = strchr(user_and_passwd, ':');
1791                         if (!colon_after_user)
1792                                 goto bad_input;
1793
1794                         /* compare "user:" */
1795                         if (cur->after_colon[0] != '*'
1796                          && strncmp(cur->after_colon, user_and_passwd,
1797                                         colon_after_user - user_and_passwd + 1) != 0
1798                         ) {
1799                                 continue;
1800                         }
1801                         /* this cfg entry is '*' or matches username from peer */
1802
1803                         passwd = strchr(cur->after_colon, ':');
1804                         if (!passwd)
1805                                 goto bad_input;
1806                         passwd++;
1807                         if (passwd[0] == '*') {
1808 # if ENABLE_PAM
1809                                 struct pam_userinfo userinfo;
1810                                 struct pam_conv conv_info = { &pam_talker, (void *) &userinfo };
1811                                 pam_handle_t *pamh;
1812
1813                                 *colon_after_user = '\0';
1814                                 userinfo.name = user_and_passwd;
1815                                 userinfo.pw = colon_after_user + 1;
1816                                 r = pam_start("httpd", user_and_passwd, &conv_info, &pamh) != PAM_SUCCESS;
1817                                 if (r == 0) {
1818                                         r = pam_authenticate(pamh, PAM_DISALLOW_NULL_AUTHTOK) != PAM_SUCCESS
1819                                          || pam_acct_mgmt(pamh, PAM_DISALLOW_NULL_AUTHTOK)    != PAM_SUCCESS
1820                                         ;
1821                                         pam_end(pamh, PAM_SUCCESS);
1822                                 }
1823                                 *colon_after_user = ':';
1824                                 goto end_check_passwd;
1825 # else
1826 #  if ENABLE_FEATURE_SHADOWPASSWDS
1827                                 /* Using _r function to avoid pulling in static buffers */
1828                                 struct spwd spw;
1829 #  endif
1830                                 struct passwd *pw;
1831
1832                                 *colon_after_user = '\0';
1833                                 pw = getpwnam(user_and_passwd);
1834                                 *colon_after_user = ':';
1835                                 if (!pw || !pw->pw_passwd)
1836                                         continue;
1837                                 passwd = pw->pw_passwd;
1838 #  if ENABLE_FEATURE_SHADOWPASSWDS
1839                                 if ((passwd[0] == 'x' || passwd[0] == '*') && !passwd[1]) {
1840                                         /* getspnam_r may return 0 yet set result to NULL.
1841                                          * At least glibc 2.4 does this. Be extra paranoid here. */
1842                                         struct spwd *result = NULL;
1843                                         r = getspnam_r(pw->pw_name, &spw, sp_buf, sizeof(sp_buf), &result);
1844                                         if (r == 0 && result)
1845                                                 passwd = result->sp_pwdp;
1846                                 }
1847 #  endif
1848                                 /* In this case, passwd is ALWAYS encrypted:
1849                                  * it came from /etc/passwd or /etc/shadow!
1850                                  */
1851                                 goto check_encrypted;
1852 # endif /* ENABLE_PAM */
1853                         }
1854                         /* Else: passwd is from httpd.conf, it is either plaintext or encrypted */
1855
1856                         if (passwd[0] == '$' && isdigit(passwd[1])) {
1857                                 char *encrypted;
1858 # if !ENABLE_PAM
1859  check_encrypted:
1860 # endif
1861                                 /* encrypt pwd from peer and check match with local one */
1862                                 encrypted = pw_encrypt(
1863                                         /* pwd (from peer): */  colon_after_user + 1,
1864                                         /* salt: */ passwd,
1865                                         /* cleanup: */ 0
1866                                 );
1867                                 r = strcmp(encrypted, passwd);
1868                                 free(encrypted);
1869                         } else {
1870                                 /* local passwd is from httpd.conf and it's plaintext */
1871                                 r = strcmp(colon_after_user + 1, passwd);
1872                         }
1873                         goto end_check_passwd;
1874                 }
1875  bad_input:
1876                 /* Comparing plaintext "user:pass" in one go */
1877                 r = strcmp(cur->after_colon, user_and_passwd);
1878  end_check_passwd:
1879                 if (r == 0) {
1880                         remoteuser = xstrndup(user_and_passwd,
1881                                 strchrnul(user_and_passwd, ':') - user_and_passwd
1882                         );
1883                         return 1; /* Ok */
1884                 }
1885         } /* for */
1886
1887         /* 0(bad) if prev is set: matches were found but passwd was wrong */
1888         return (prev == NULL);
1889 }
1890 #endif  /* FEATURE_HTTPD_BASIC_AUTH */
1891
1892 #if ENABLE_FEATURE_HTTPD_PROXY
1893 static Htaccess_Proxy *find_proxy_entry(const char *url)
1894 {
1895         Htaccess_Proxy *p;
1896         for (p = proxy; p; p = p->next) {
1897                 if (strncmp(url, p->url_from, strlen(p->url_from)) == 0)
1898                         return p;
1899         }
1900         return NULL;
1901 }
1902 #endif
1903
1904 /*
1905  * Handle timeouts
1906  */
1907 static void send_REQUEST_TIMEOUT_and_exit(int sig) NORETURN;
1908 static void send_REQUEST_TIMEOUT_and_exit(int sig UNUSED_PARAM)
1909 {
1910         send_headers_and_exit(HTTP_REQUEST_TIMEOUT);
1911 }
1912
1913 /*
1914  * Handle an incoming http request and exit.
1915  */
1916 static void handle_incoming_and_exit(const len_and_sockaddr *fromAddr) NORETURN;
1917 static void handle_incoming_and_exit(const len_and_sockaddr *fromAddr)
1918 {
1919         static const char request_GET[] ALIGN1 = "GET";
1920         struct stat sb;
1921         char *urlcopy;
1922         char *urlp;
1923         char *tptr;
1924 #if ENABLE_FEATURE_HTTPD_CGI
1925         static const char request_HEAD[] ALIGN1 = "HEAD";
1926         const char *prequest;
1927         char *cookie = NULL;
1928         char *content_type = NULL;
1929         unsigned long length = 0;
1930 #elif ENABLE_FEATURE_HTTPD_PROXY
1931 #define prequest request_GET
1932         unsigned long length = 0;
1933 #endif
1934 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
1935         smallint authorized = -1;
1936 #endif
1937         smallint ip_allowed;
1938         char http_major_version;
1939 #if ENABLE_FEATURE_HTTPD_PROXY
1940         char http_minor_version;
1941         char *header_buf = header_buf; /* for gcc */
1942         char *header_ptr = header_ptr;
1943         Htaccess_Proxy *proxy_entry;
1944 #endif
1945
1946         /* Allocation of iobuf is postponed until now
1947          * (IOW, server process doesn't need to waste 8k) */
1948         iobuf = xmalloc(IOBUF_SIZE);
1949
1950         rmt_ip = 0;
1951         if (fromAddr->u.sa.sa_family == AF_INET) {
1952                 rmt_ip = ntohl(fromAddr->u.sin.sin_addr.s_addr);
1953         }
1954 #if ENABLE_FEATURE_IPV6
1955         if (fromAddr->u.sa.sa_family == AF_INET6
1956          && fromAddr->u.sin6.sin6_addr.s6_addr32[0] == 0
1957          && fromAddr->u.sin6.sin6_addr.s6_addr32[1] == 0
1958          && ntohl(fromAddr->u.sin6.sin6_addr.s6_addr32[2]) == 0xffff)
1959                 rmt_ip = ntohl(fromAddr->u.sin6.sin6_addr.s6_addr32[3]);
1960 #endif
1961         if (ENABLE_FEATURE_HTTPD_CGI || DEBUG || verbose) {
1962                 /* NB: can be NULL (user runs httpd -i by hand?) */
1963                 rmt_ip_str = xmalloc_sockaddr2dotted(&fromAddr->u.sa);
1964         }
1965         if (verbose) {
1966                 /* this trick makes -v logging much simpler */
1967                 if (rmt_ip_str)
1968                         applet_name = rmt_ip_str;
1969                 if (verbose > 2)
1970                         bb_error_msg("connected");
1971         }
1972
1973         /* Install timeout handler. get_line() needs it. */
1974         signal(SIGALRM, send_REQUEST_TIMEOUT_and_exit);
1975
1976         if (!get_line()) /* EOF or error or empty line */
1977                 send_headers_and_exit(HTTP_BAD_REQUEST);
1978
1979         /* Determine type of request (GET/POST) */
1980         // rfc2616: method and URI is separated by exactly one space
1981         //urlp = strpbrk(iobuf, " \t"); - no, tab isn't allowed
1982         urlp = strchr(iobuf, ' ');
1983         if (urlp == NULL)
1984                 send_headers_and_exit(HTTP_BAD_REQUEST);
1985         *urlp++ = '\0';
1986 #if ENABLE_FEATURE_HTTPD_CGI
1987         prequest = request_GET;
1988         if (strcasecmp(iobuf, prequest) != 0) {
1989                 prequest = request_HEAD;
1990                 if (strcasecmp(iobuf, prequest) != 0) {
1991                         prequest = "POST";
1992                         if (strcasecmp(iobuf, prequest) != 0)
1993                                 send_headers_and_exit(HTTP_NOT_IMPLEMENTED);
1994                 }
1995         }
1996 #else
1997         if (strcasecmp(iobuf, request_GET) != 0)
1998                 send_headers_and_exit(HTTP_NOT_IMPLEMENTED);
1999 #endif
2000         // rfc2616: method and URI is separated by exactly one space
2001         //urlp = skip_whitespace(urlp); - should not be necessary
2002         if (urlp[0] != '/')
2003                 send_headers_and_exit(HTTP_BAD_REQUEST);
2004
2005         /* Find end of URL and parse HTTP version, if any */
2006         http_major_version = '0';
2007         IF_FEATURE_HTTPD_PROXY(http_minor_version = '0';)
2008         tptr = strchrnul(urlp, ' ');
2009         /* Is it " HTTP/"? */
2010         if (tptr[0] && strncmp(tptr + 1, HTTP_200, 5) == 0) {
2011                 http_major_version = tptr[6];
2012                 IF_FEATURE_HTTPD_PROXY(http_minor_version = tptr[8];)
2013         }
2014         *tptr = '\0';
2015
2016         /* Copy URL from after "GET "/"POST " to stack-allocated char[] */
2017         urlcopy = alloca((tptr - urlp) + 2 + strlen(index_page));
2018         /*if (urlcopy == NULL)
2019          *      send_headers_and_exit(HTTP_INTERNAL_SERVER_ERROR);*/
2020         strcpy(urlcopy, urlp);
2021         /* NB: urlcopy ptr is never changed after this */
2022
2023         /* Extract url args if present */
2024         /* g_query = NULL; - already is */
2025         tptr = strchr(urlcopy, '?');
2026         if (tptr) {
2027                 *tptr++ = '\0';
2028                 g_query = tptr;
2029         }
2030
2031         /* Decode URL escape sequences */
2032         tptr = percent_decode_in_place(urlcopy, /*strict:*/ 1);
2033         if (tptr == NULL)
2034                 send_headers_and_exit(HTTP_BAD_REQUEST);
2035         if (tptr == urlcopy + 1) {
2036                 /* '/' or NUL is encoded */
2037                 send_headers_and_exit(HTTP_NOT_FOUND);
2038         }
2039
2040         /* Canonicalize path */
2041         /* Algorithm stolen from libbb bb_simplify_path(),
2042          * but don't strdup, retain trailing slash, protect root */
2043         urlp = tptr = urlcopy;
2044         for (;;) {
2045                 if (*urlp == '/') {
2046                         /* skip duplicate (or initial) slash */
2047                         if (*tptr == '/') {
2048                                 goto next_char;
2049                         }
2050                         if (*tptr == '.') {
2051                                 if (tptr[1] == '.' && (tptr[2] == '/' || tptr[2] == '\0')) {
2052                                         /* "..": be careful */
2053                                         /* protect root */
2054                                         if (urlp == urlcopy)
2055                                                 send_headers_and_exit(HTTP_BAD_REQUEST);
2056                                         /* omit previous dir */
2057                                         while (*--urlp != '/')
2058                                                 continue;
2059                                         /* skip to "./" or ".<NUL>" */
2060                                         tptr++;
2061                                 }
2062                                 if (tptr[1] == '/' || tptr[1] == '\0') {
2063                                         /* skip extra "/./" */
2064                                         goto next_char;
2065                                 }
2066                         }
2067                 }
2068                 *++urlp = *tptr;
2069                 if (*urlp == '\0')
2070                         break;
2071  next_char:
2072                 tptr++;
2073         }
2074
2075         /* If URL is a directory, add '/' */
2076         if (urlp[-1] != '/') {
2077                 if (is_directory(urlcopy + 1, /*followlinks:*/ 1)) {
2078                         found_moved_temporarily = urlcopy;
2079                 }
2080         }
2081
2082         /* Log it */
2083         if (verbose > 1)
2084                 bb_error_msg("url:%s", urlcopy);
2085
2086         tptr = urlcopy;
2087         ip_allowed = checkPermIP();
2088         while (ip_allowed && (tptr = strchr(tptr + 1, '/')) != NULL) {
2089                 /* have path1/path2 */
2090                 *tptr = '\0';
2091                 if (is_directory(urlcopy + 1, /*followlinks:*/ 1)) {
2092                         /* may have subdir config */
2093                         parse_conf(urlcopy + 1, SUBDIR_PARSE);
2094                         ip_allowed = checkPermIP();
2095                 }
2096                 *tptr = '/';
2097         }
2098
2099 #if ENABLE_FEATURE_HTTPD_PROXY
2100         proxy_entry = find_proxy_entry(urlcopy);
2101         if (proxy_entry)
2102                 header_buf = header_ptr = xmalloc(IOBUF_SIZE);
2103 #endif
2104
2105         if (http_major_version >= '0') {
2106                 /* Request was with "... HTTP/nXXX", and n >= 0 */
2107
2108                 /* Read until blank line */
2109                 while (1) {
2110                         if (!get_line())
2111                                 break; /* EOF or error or empty line */
2112                         if (DEBUG)
2113                                 bb_error_msg("header: '%s'", iobuf);
2114
2115 #if ENABLE_FEATURE_HTTPD_PROXY
2116                         /* We need 2 more bytes for yet another "\r\n" -
2117                          * see near fdprintf(proxy_fd...) further below */
2118                         if (proxy_entry && (header_ptr - header_buf) < IOBUF_SIZE - 2) {
2119                                 int len = strlen(iobuf);
2120                                 if (len > IOBUF_SIZE - (header_ptr - header_buf) - 4)
2121                                         len = IOBUF_SIZE - (header_ptr - header_buf) - 4;
2122                                 memcpy(header_ptr, iobuf, len);
2123                                 header_ptr += len;
2124                                 header_ptr[0] = '\r';
2125                                 header_ptr[1] = '\n';
2126                                 header_ptr += 2;
2127                         }
2128 #endif
2129
2130 #if ENABLE_FEATURE_HTTPD_CGI || ENABLE_FEATURE_HTTPD_PROXY
2131                         /* Try and do our best to parse more lines */
2132                         if ((STRNCASECMP(iobuf, "Content-length:") == 0)) {
2133                                 /* extra read only for POST */
2134                                 if (prequest != request_GET
2135 # if ENABLE_FEATURE_HTTPD_CGI
2136                                  && prequest != request_HEAD
2137 # endif
2138                                 ) {
2139                                         tptr = skip_whitespace(iobuf + sizeof("Content-length:") - 1);
2140                                         if (!tptr[0])
2141                                                 send_headers_and_exit(HTTP_BAD_REQUEST);
2142                                         /* not using strtoul: it ignores leading minus! */
2143                                         length = bb_strtou(tptr, NULL, 10);
2144                                         /* length is "ulong", but we need to pass it to int later */
2145                                         if (errno || length > INT_MAX)
2146                                                 send_headers_and_exit(HTTP_BAD_REQUEST);
2147                                 }
2148                         }
2149 #endif
2150 #if ENABLE_FEATURE_HTTPD_CGI
2151                         else if (STRNCASECMP(iobuf, "Cookie:") == 0) {
2152                                 cookie = xstrdup(skip_whitespace(iobuf + sizeof("Cookie:")-1));
2153                         } else if (STRNCASECMP(iobuf, "Content-Type:") == 0) {
2154                                 content_type = xstrdup(skip_whitespace(iobuf + sizeof("Content-Type:")-1));
2155                         } else if (STRNCASECMP(iobuf, "Referer:") == 0) {
2156                                 referer = xstrdup(skip_whitespace(iobuf + sizeof("Referer:")-1));
2157                         } else if (STRNCASECMP(iobuf, "User-Agent:") == 0) {
2158                                 user_agent = xstrdup(skip_whitespace(iobuf + sizeof("User-Agent:")-1));
2159                         } else if (STRNCASECMP(iobuf, "Host:") == 0) {
2160                                 host = xstrdup(skip_whitespace(iobuf + sizeof("Host:")-1));
2161                         } else if (STRNCASECMP(iobuf, "Accept:") == 0) {
2162                                 http_accept = xstrdup(skip_whitespace(iobuf + sizeof("Accept:")-1));
2163                         } else if (STRNCASECMP(iobuf, "Accept-Language:") == 0) {
2164                                 http_accept_language = xstrdup(skip_whitespace(iobuf + sizeof("Accept-Language:")-1));
2165                         }
2166 #endif
2167 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
2168                         if (STRNCASECMP(iobuf, "Authorization:") == 0) {
2169                                 /* We only allow Basic credentials.
2170                                  * It shows up as "Authorization: Basic <user>:<passwd>" where
2171                                  * "<user>:<passwd>" is base64 encoded.
2172                                  */
2173                                 tptr = skip_whitespace(iobuf + sizeof("Authorization:")-1);
2174                                 if (STRNCASECMP(tptr, "Basic") != 0)
2175                                         continue;
2176                                 tptr += sizeof("Basic")-1;
2177                                 /* decodeBase64() skips whitespace itself */
2178                                 decodeBase64(tptr);
2179                                 authorized = check_user_passwd(urlcopy, tptr);
2180                         }
2181 #endif
2182 #if ENABLE_FEATURE_HTTPD_RANGES
2183                         if (STRNCASECMP(iobuf, "Range:") == 0) {
2184                                 /* We know only bytes=NNN-[MMM] */
2185                                 char *s = skip_whitespace(iobuf + sizeof("Range:")-1);
2186                                 if (strncmp(s, "bytes=", 6) == 0) {
2187                                         s += sizeof("bytes=")-1;
2188                                         range_start = BB_STRTOOFF(s, &s, 10);
2189                                         if (s[0] != '-' || range_start < 0) {
2190                                                 range_start = -1;
2191                                         } else if (s[1]) {
2192                                                 range_end = BB_STRTOOFF(s+1, NULL, 10);
2193                                                 if (errno || range_end < range_start)
2194                                                         range_start = -1;
2195                                         }
2196                                 }
2197                         }
2198 #endif
2199 #if ENABLE_FEATURE_HTTPD_GZIP
2200                         if (STRNCASECMP(iobuf, "Accept-Encoding:") == 0) {
2201                                 /* Note: we do not support "gzip;q=0"
2202                                  * method of _disabling_ gzip
2203                                  * delivery. No one uses that, though */
2204                                 const char *s = strstr(iobuf, "gzip");
2205                                 if (s) {
2206                                         // want more thorough checks?
2207                                         //if (s[-1] == ' '
2208                                         // || s[-1] == ','
2209                                         // || s[-1] == ':'
2210                                         //) {
2211                                                 content_gzip = 1;
2212                                         //}
2213                                 }
2214                         }
2215 #endif
2216                 } /* while extra header reading */
2217         }
2218
2219         /* We are done reading headers, disable peer timeout */
2220         alarm(0);
2221
2222         if (strcmp(bb_basename(urlcopy), HTTPD_CONF) == 0 || !ip_allowed) {
2223                 /* protect listing [/path]/httpd.conf or IP deny */
2224                 send_headers_and_exit(HTTP_FORBIDDEN);
2225         }
2226
2227 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
2228         /* Case: no "Authorization:" was seen, but page might require passwd.
2229          * Check that with dummy user:pass */
2230         if (authorized < 0)
2231                 authorized = check_user_passwd(urlcopy, (char *) "");
2232         if (!authorized)
2233                 send_headers_and_exit(HTTP_UNAUTHORIZED);
2234 #endif
2235
2236         if (found_moved_temporarily) {
2237                 send_headers_and_exit(HTTP_MOVED_TEMPORARILY);
2238         }
2239
2240 #if ENABLE_FEATURE_HTTPD_PROXY
2241         if (proxy_entry != NULL) {
2242                 int proxy_fd;
2243                 len_and_sockaddr *lsa;
2244
2245                 proxy_fd = socket(AF_INET, SOCK_STREAM, 0);
2246                 if (proxy_fd < 0)
2247                         send_headers_and_exit(HTTP_INTERNAL_SERVER_ERROR);
2248                 lsa = host2sockaddr(proxy_entry->host_port, 80);
2249                 if (lsa == NULL)
2250                         send_headers_and_exit(HTTP_INTERNAL_SERVER_ERROR);
2251                 if (connect(proxy_fd, &lsa->u.sa, lsa->len) < 0)
2252                         send_headers_and_exit(HTTP_INTERNAL_SERVER_ERROR);
2253                 fdprintf(proxy_fd, "%s %s%s%s%s HTTP/%c.%c\r\n",
2254                                 prequest, /* GET or POST */
2255                                 proxy_entry->url_to, /* url part 1 */
2256                                 urlcopy + strlen(proxy_entry->url_from), /* url part 2 */
2257                                 (g_query ? "?" : ""), /* "?" (maybe) */
2258                                 (g_query ? g_query : ""), /* query string (maybe) */
2259                                 http_major_version, http_minor_version);
2260                 header_ptr[0] = '\r';
2261                 header_ptr[1] = '\n';
2262                 header_ptr += 2;
2263                 write(proxy_fd, header_buf, header_ptr - header_buf);
2264                 free(header_buf); /* on the order of 8k, free it */
2265                 cgi_io_loop_and_exit(proxy_fd, proxy_fd, length);
2266         }
2267 #endif
2268
2269         tptr = urlcopy + 1;      /* skip first '/' */
2270
2271 #if ENABLE_FEATURE_HTTPD_CGI
2272         if (strncmp(tptr, "cgi-bin/", 8) == 0) {
2273                 if (tptr[8] == '\0') {
2274                         /* protect listing "cgi-bin/" */
2275                         send_headers_and_exit(HTTP_FORBIDDEN);
2276                 }
2277                 send_cgi_and_exit(urlcopy, urlcopy, prequest, length, cookie, content_type);
2278         }
2279 #endif
2280
2281         if (urlp[-1] == '/') {
2282                 /* When index_page string is appended to <dir>/ URL, it overwrites
2283                  * the query string. If we fall back to call /cgi-bin/index.cgi,
2284                  * query string would be lost and not available to the CGI.
2285                  * Work around it by making a deep copy.
2286                  */
2287                 if (ENABLE_FEATURE_HTTPD_CGI)
2288                         g_query = xstrdup(g_query); /* ok for NULL too */
2289                 strcpy(urlp, index_page);
2290         }
2291         if (stat(tptr, &sb) == 0) {
2292 #if ENABLE_FEATURE_HTTPD_CONFIG_WITH_SCRIPT_INTERPR
2293                 char *suffix = strrchr(tptr, '.');
2294                 if (suffix) {
2295                         Htaccess *cur;
2296                         for (cur = script_i; cur; cur = cur->next) {
2297                                 if (strcmp(cur->before_colon + 1, suffix) == 0) {
2298                                         send_cgi_and_exit(urlcopy, urlcopy, prequest, length, cookie, content_type);
2299                                 }
2300                         }
2301                 }
2302 #endif
2303                 file_size = sb.st_size;
2304                 last_mod = sb.st_mtime;
2305         }
2306 #if ENABLE_FEATURE_HTTPD_CGI
2307         else if (urlp[-1] == '/') {
2308                 /* It's a dir URL and there is no index.html
2309                  * Try cgi-bin/index.cgi */
2310                 if (access("/cgi-bin/index.cgi"+1, X_OK) == 0) {
2311                         urlp[0] = '\0'; /* remove index_page */
2312                         send_cgi_and_exit("/cgi-bin/index.cgi", urlcopy, prequest, length, cookie, content_type);
2313                 }
2314         }
2315         /* else fall through to send_file, it errors out if open fails: */
2316
2317         if (prequest != request_GET && prequest != request_HEAD) {
2318                 /* POST for files does not make sense */
2319                 send_headers_and_exit(HTTP_NOT_IMPLEMENTED);
2320         }
2321         send_file_and_exit(tptr,
2322                 (prequest != request_HEAD ? SEND_HEADERS_AND_BODY : SEND_HEADERS)
2323         );
2324 #else
2325         send_file_and_exit(tptr, SEND_HEADERS_AND_BODY);
2326 #endif
2327 }
2328
2329 /*
2330  * The main http server function.
2331  * Given a socket, listen for new connections and farm out
2332  * the processing as a [v]forked process.
2333  * Never returns.
2334  */
2335 #if BB_MMU
2336 static void mini_httpd(int server_socket) NORETURN;
2337 static void mini_httpd(int server_socket)
2338 {
2339         /* NB: it's best to not use xfuncs in this loop before fork().
2340          * Otherwise server may die on transient errors (temporary
2341          * out-of-memory condition, etc), which is Bad(tm).
2342          * Try to do any dangerous calls after fork.
2343          */
2344         while (1) {
2345                 int n;
2346                 len_and_sockaddr fromAddr;
2347
2348                 /* Wait for connections... */
2349                 fromAddr.len = LSA_SIZEOF_SA;
2350                 n = accept(server_socket, &fromAddr.u.sa, &fromAddr.len);
2351                 if (n < 0)
2352                         continue;
2353
2354                 /* set the KEEPALIVE option to cull dead connections */
2355                 setsockopt(n, SOL_SOCKET, SO_KEEPALIVE, &const_int_1, sizeof(const_int_1));
2356
2357                 if (fork() == 0) {
2358                         /* child */
2359                         /* Do not reload config on HUP */
2360                         signal(SIGHUP, SIG_IGN);
2361                         close(server_socket);
2362                         xmove_fd(n, 0);
2363                         xdup2(0, 1);
2364
2365                         handle_incoming_and_exit(&fromAddr);
2366                 }
2367                 /* parent, or fork failed */
2368                 close(n);
2369         } /* while (1) */
2370         /* never reached */
2371 }
2372 #else
2373 static void mini_httpd_nommu(int server_socket, int argc, char **argv) NORETURN;
2374 static void mini_httpd_nommu(int server_socket, int argc, char **argv)
2375 {
2376         char *argv_copy[argc + 2];
2377
2378         argv_copy[0] = argv[0];
2379         argv_copy[1] = (char*)"-i";
2380         memcpy(&argv_copy[2], &argv[1], argc * sizeof(argv[0]));
2381
2382         /* NB: it's best to not use xfuncs in this loop before vfork().
2383          * Otherwise server may die on transient errors (temporary
2384          * out-of-memory condition, etc), which is Bad(tm).
2385          * Try to do any dangerous calls after fork.
2386          */
2387         while (1) {
2388                 int n;
2389                 len_and_sockaddr fromAddr;
2390
2391                 /* Wait for connections... */
2392                 fromAddr.len = LSA_SIZEOF_SA;
2393                 n = accept(server_socket, &fromAddr.u.sa, &fromAddr.len);
2394                 if (n < 0)
2395                         continue;
2396
2397                 /* set the KEEPALIVE option to cull dead connections */
2398                 setsockopt(n, SOL_SOCKET, SO_KEEPALIVE, &const_int_1, sizeof(const_int_1));
2399
2400                 if (vfork() == 0) {
2401                         /* child */
2402                         /* Do not reload config on HUP */
2403                         signal(SIGHUP, SIG_IGN);
2404                         close(server_socket);
2405                         xmove_fd(n, 0);
2406                         xdup2(0, 1);
2407
2408                         /* Run a copy of ourself in inetd mode */
2409                         re_exec(argv_copy);
2410                 }
2411                 argv_copy[0][0] &= 0x7f;
2412                 /* parent, or vfork failed */
2413                 close(n);
2414         } /* while (1) */
2415         /* never reached */
2416 }
2417 #endif
2418
2419 /*
2420  * Process a HTTP connection on stdin/out.
2421  * Never returns.
2422  */
2423 static void mini_httpd_inetd(void) NORETURN;
2424 static void mini_httpd_inetd(void)
2425 {
2426         len_and_sockaddr fromAddr;
2427
2428         memset(&fromAddr, 0, sizeof(fromAddr));
2429         fromAddr.len = LSA_SIZEOF_SA;
2430         /* NB: can fail if user runs it by hand and types in http cmds */
2431         getpeername(0, &fromAddr.u.sa, &fromAddr.len);
2432         handle_incoming_and_exit(&fromAddr);
2433 }
2434
2435 static void sighup_handler(int sig UNUSED_PARAM)
2436 {
2437         parse_conf(DEFAULT_PATH_HTTPD_CONF, SIGNALED_PARSE);
2438 }
2439
2440 enum {
2441         c_opt_config_file = 0,
2442         d_opt_decode_url,
2443         h_opt_home_httpd,
2444         IF_FEATURE_HTTPD_ENCODE_URL_STR(e_opt_encode_url,)
2445         IF_FEATURE_HTTPD_BASIC_AUTH(    r_opt_realm     ,)
2446         IF_FEATURE_HTTPD_AUTH_MD5(      m_opt_md5       ,)
2447         IF_FEATURE_HTTPD_SETUID(        u_opt_setuid    ,)
2448         p_opt_port      ,
2449         p_opt_inetd     ,
2450         p_opt_foreground,
2451         p_opt_verbose   ,
2452         OPT_CONFIG_FILE = 1 << c_opt_config_file,
2453         OPT_DECODE_URL  = 1 << d_opt_decode_url,
2454         OPT_HOME_HTTPD  = 1 << h_opt_home_httpd,
2455         OPT_ENCODE_URL  = IF_FEATURE_HTTPD_ENCODE_URL_STR((1 << e_opt_encode_url)) + 0,
2456         OPT_REALM       = IF_FEATURE_HTTPD_BASIC_AUTH(    (1 << r_opt_realm     )) + 0,
2457         OPT_MD5         = IF_FEATURE_HTTPD_AUTH_MD5(      (1 << m_opt_md5       )) + 0,
2458         OPT_SETUID      = IF_FEATURE_HTTPD_SETUID(        (1 << u_opt_setuid    )) + 0,
2459         OPT_PORT        = 1 << p_opt_port,
2460         OPT_INETD       = 1 << p_opt_inetd,
2461         OPT_FOREGROUND  = 1 << p_opt_foreground,
2462         OPT_VERBOSE     = 1 << p_opt_verbose,
2463 };
2464
2465
2466 int httpd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
2467 int httpd_main(int argc UNUSED_PARAM, char **argv)
2468 {
2469         int server_socket = server_socket; /* for gcc */
2470         unsigned opt;
2471         char *url_for_decode;
2472         IF_FEATURE_HTTPD_ENCODE_URL_STR(const char *url_for_encode;)
2473         IF_FEATURE_HTTPD_SETUID(const char *s_ugid = NULL;)
2474         IF_FEATURE_HTTPD_SETUID(struct bb_uidgid_t ugid;)
2475         IF_FEATURE_HTTPD_AUTH_MD5(const char *pass;)
2476
2477         INIT_G();
2478
2479 #if ENABLE_LOCALE_SUPPORT
2480         /* Undo busybox.c: we want to speak English in http (dates etc) */
2481         setlocale(LC_TIME, "C");
2482 #endif
2483
2484         home_httpd = xrealloc_getcwd_or_warn(NULL);
2485         /* -v counts, -i implies -f */
2486         opt_complementary = "vv:if";
2487         /* We do not "absolutize" path given by -h (home) opt.
2488          * If user gives relative path in -h,
2489          * $SCRIPT_FILENAME will not be set. */
2490         opt = getopt32(argv, "c:d:h:"
2491                         IF_FEATURE_HTTPD_ENCODE_URL_STR("e:")
2492                         IF_FEATURE_HTTPD_BASIC_AUTH("r:")
2493                         IF_FEATURE_HTTPD_AUTH_MD5("m:")
2494                         IF_FEATURE_HTTPD_SETUID("u:")
2495                         "p:ifv",
2496                         &opt_c_configFile, &url_for_decode, &home_httpd
2497                         IF_FEATURE_HTTPD_ENCODE_URL_STR(, &url_for_encode)
2498                         IF_FEATURE_HTTPD_BASIC_AUTH(, &g_realm)
2499                         IF_FEATURE_HTTPD_AUTH_MD5(, &pass)
2500                         IF_FEATURE_HTTPD_SETUID(, &s_ugid)
2501                         , &bind_addr_or_port
2502                         , &verbose
2503                 );
2504         if (opt & OPT_DECODE_URL) {
2505                 fputs(percent_decode_in_place(url_for_decode, /*strict:*/ 0), stdout);
2506                 return 0;
2507         }
2508 #if ENABLE_FEATURE_HTTPD_ENCODE_URL_STR
2509         if (opt & OPT_ENCODE_URL) {
2510                 fputs(encodeString(url_for_encode), stdout);
2511                 return 0;
2512         }
2513 #endif
2514 #if ENABLE_FEATURE_HTTPD_AUTH_MD5
2515         if (opt & OPT_MD5) {
2516                 char salt[sizeof("$1$XXXXXXXX")];
2517                 salt[0] = '$';
2518                 salt[1] = '1';
2519                 salt[2] = '$';
2520                 crypt_make_salt(salt + 3, 4);
2521                 puts(pw_encrypt(pass, salt, /*cleanup:*/ 0));
2522                 return 0;
2523         }
2524 #endif
2525 #if ENABLE_FEATURE_HTTPD_SETUID
2526         if (opt & OPT_SETUID) {
2527                 xget_uidgid(&ugid, s_ugid);
2528         }
2529 #endif
2530
2531 #if !BB_MMU
2532         if (!(opt & OPT_FOREGROUND)) {
2533                 bb_daemonize_or_rexec(0, argv); /* don't change current directory */
2534         }
2535 #endif
2536
2537         xchdir(home_httpd);
2538         if (!(opt & OPT_INETD)) {
2539                 signal(SIGCHLD, SIG_IGN);
2540                 server_socket = openServer();
2541 #if ENABLE_FEATURE_HTTPD_SETUID
2542                 /* drop privileges */
2543                 if (opt & OPT_SETUID) {
2544                         if (ugid.gid != (gid_t)-1) {
2545                                 if (setgroups(1, &ugid.gid) == -1)
2546                                         bb_perror_msg_and_die("setgroups");
2547                                 xsetgid(ugid.gid);
2548                         }
2549                         xsetuid(ugid.uid);
2550                 }
2551 #endif
2552         }
2553
2554 #if 0
2555         /* User can do it himself: 'env - PATH="$PATH" httpd'
2556          * We don't do it because we don't want to screw users
2557          * which want to do
2558          * 'env - VAR1=val1 VAR2=val2 httpd'
2559          * and have VAR1 and VAR2 values visible in their CGIs.
2560          * Besides, it is also smaller. */
2561         {
2562                 char *p = getenv("PATH");
2563                 /* env strings themself are not freed, no need to xstrdup(p): */
2564                 clearenv();
2565                 if (p)
2566                         putenv(p - 5);
2567 //              if (!(opt & OPT_INETD))
2568 //                      setenv_long("SERVER_PORT", ???);
2569         }
2570 #endif
2571
2572         parse_conf(DEFAULT_PATH_HTTPD_CONF, FIRST_PARSE);
2573         if (!(opt & OPT_INETD))
2574                 signal(SIGHUP, sighup_handler);
2575
2576         xfunc_error_retval = 0;
2577         if (opt & OPT_INETD)
2578                 mini_httpd_inetd();
2579 #if BB_MMU
2580         if (!(opt & OPT_FOREGROUND))
2581                 bb_daemonize(0); /* don't change current directory */
2582         mini_httpd(server_socket); /* never returns */
2583 #else
2584         mini_httpd_nommu(server_socket, argc, argv); /* never returns */
2585 #endif
2586         /* return 0; */
2587 }