networking/httpd.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * httpd implementation for busybox
   4  *
   5  * Copyright (C) 2002,2003 Glenn Engel <glenne@engel.org>
   6  * Copyright (C) 2003-2006 Vladimir Oleynik <dzo@simtreas.ru>
   7  *
   8  * Licensed under GPLv2 or later, see file LICENSE in this source tree.
   9  *
  10  *****************************************************************************
  11  *
  12  * Typical usage:
  13  * For non root user:
  14  *      httpd -p 8080 -h $HOME/public_html
  15  * For daemon start from rc script with uid=0:
  16  *      httpd -u www
  17  * which is equivalent to (assuming user www has uid 80):
  18  *      httpd -p 80 -u 80 -h $PWD -c /etc/httpd.conf -r "Web Server Authentication"
  19  *
  20  * When an url starts with "/cgi-bin/" it is assumed to be a cgi script.
  21  * The server changes directory to the location of the script and executes it
  22  * after setting QUERY_STRING and other environment variables.
  23  *
  24  * If directory URL is given, no index.html is found and CGI support is enabled,
  25  * cgi-bin/index.cgi will be run. Directory to list is ../$QUERY_STRING.
  26  * See httpd_indexcgi.c for an example GCI code.
  27  *
  28  * Doc:
  29  * "CGI Environment Variables": http://hoohoo.ncsa.uiuc.edu/cgi/env.html
  30  *
  31  * The applet can also be invoked as an url arg decoder and html text encoder
  32  * as follows:
  33  *      foo=`httpd -d $foo`             # decode "Hello%20World" as "Hello World"
  34  *      bar=`httpd -e "<Hello World>"`  # encode as "&#60Hello&#32World&#62"
  35  * Note that url encoding for arguments is not the same as html encoding for
  36  * presentation.  -d decodes an url-encoded argument while -e encodes in html
  37  * for page display.
  38  *
  39  * httpd.conf has the following format:
  40  *
  41  * H:/serverroot     # define the server root. It will override -h
  42  * A:172.20.         # Allow address from 172.20.0.0/16
  43  * A:10.0.0.0/25     # Allow any address from 10.0.0.0-10.0.0.127
  44  * A:10.0.0.0/255.255.255.128  # Allow any address that previous set
  45  * A:127.0.0.1       # Allow local loopback connections
  46  * D:*               # Deny from other IP connections
  47  * E404:/path/e404.html # /path/e404.html is the 404 (not found) error page
  48  * I:index.html      # Show index.html when a directory is requested
  49  *
  50  * P:/url:[http://]hostname[:port]/new/path
  51  *                   # When /urlXXXXXX is requested, reverse proxy
  52  *                   # it to http://hostname[:port]/new/pathXXXXXX
  53  *
  54  * /cgi-bin:foo:bar  # Require user foo, pwd bar on urls starting with /cgi-bin/
  55  * /adm:admin:setup  # Require user admin, pwd setup on urls starting with /adm/
  56  * /adm:toor:PaSsWd  # or user toor, pwd PaSsWd on urls starting with /adm/
  57  * /adm:root:*       # or user root, pwd from /etc/passwd on urls starting with /adm/
  58  * /wiki:*:*         # or any user from /etc/passwd with according pwd on urls starting with /wiki/
  59  * .au:audio/basic   # additional mime type for audio.au files
  60  * *.php:/path/php   # run xxx.php through an interpreter
  61  *
  62  * A/D may be as a/d or allow/deny - only first char matters.
  63  * Deny/Allow IP logic:
  64  *  - Default is to allow all (Allow all (A:*) is a no-op).
  65  *  - Deny rules take precedence over allow rules.
  66  *  - "Deny all" rule (D:*) is applied last.
  67  *
  68  * Example:
  69  *   1. Allow only specified addresses
  70  *     A:172.20          # Allow any address that begins with 172.20.
  71  *     A:10.10.          # Allow any address that begins with 10.10.
  72  *     A:127.0.0.1       # Allow local loopback connections
  73  *     D:*               # Deny from other IP connections
  74  *
  75  *   2. Only deny specified addresses
  76  *     D:1.2.3.        # deny from 1.2.3.0 - 1.2.3.255
  77  *     D:2.3.4.        # deny from 2.3.4.0 - 2.3.4.255
  78  *     A:*             # (optional line added for clarity)
  79  *
  80  * If a sub directory contains config file, it is parsed and merged with
  81  * any existing settings as if it was appended to the original configuration.
  82  *
  83  * subdir paths are relative to the containing subdir and thus cannot
  84  * affect the parent rules.
  85  *
  86  * Note that since the sub dir is parsed in the forked thread servicing the
  87  * subdir http request, any merge is discarded when the process exits.  As a
  88  * result, the subdir settings only have a lifetime of a single request.
  89  *
  90  * Custom error pages can contain an absolute path or be relative to
  91  * 'home_httpd'. Error pages are to be static files (no CGI or script). Error
  92  * page can only be defined in the root configuration file and are not taken
  93  * into account in local (directories) config files.
  94  *
  95  * If -c is not set, an attempt will be made to open the default
  96  * root configuration file.  If -c is set and the file is not found, the
  97  * server exits with an error.
  98  *
  99  */
 100  /* TODO: use TCP_CORK, parse_config() */
 101
 102 //usage:#define httpd_trivial_usage
 103 //usage:       "[-ifv[v]]"
 104 //usage:       " [-c CONFFILE]"
 105 //usage:       " [-p [IP:]PORT]"
 106 //usage:        IF_FEATURE_HTTPD_SETUID(" [-u USER[:GRP]]")
 107 //usage:        IF_FEATURE_HTTPD_BASIC_AUTH(" [-r REALM]")
 108 //usage:       " [-h HOME]\n"
 109 //usage:       "or httpd -d/-e" IF_FEATURE_HTTPD_AUTH_MD5("/-m") " STRING"
 110 //usage:#define httpd_full_usage "\n\n"
 111 //usage:       "Listen for incoming HTTP requests\n"
 112 //usage:     "\n        -i              Inetd mode"
 113 //usage:     "\n        -f              Don't daemonize"
 114 //usage:     "\n        -v[v]           Verbose"
 115 //usage:     "\n        -p [IP:]PORT    Bind to IP:PORT (default *:80)"
 116 //usage:        IF_FEATURE_HTTPD_SETUID(
 117 //usage:     "\n        -u USER[:GRP]   Set uid/gid after binding to port")
 118 //usage:        IF_FEATURE_HTTPD_BASIC_AUTH(
 119 //usage:     "\n        -r REALM        Authentication Realm for Basic Authentication")
 120 //usage:     "\n        -h HOME         Home directory (default .)"
 121 //usage:     "\n        -c FILE         Configuration file (default {/etc,HOME}/httpd.conf)"
 122 //usage:        IF_FEATURE_HTTPD_AUTH_MD5(
 123 //usage:     "\n        -m STRING       MD5 crypt STRING")
 124 //usage:     "\n        -e STRING       HTML encode STRING"
 125 //usage:     "\n        -d STRING       URL decode STRING"
 126
 127 #include "libbb.h"
 128 #include "common_bufsiz.h"
 129 #if ENABLE_PAM
 130 /* PAM may include <locale.h>. We may need to undefine bbox's stub define: */
 131 # undef setlocale
 132 /* For some obscure reason, PAM is not in pam/xxx, but in security/xxx.
 133  * Apparently they like to confuse people. */
 134 # include <security/pam_appl.h>
 135 # include <security/pam_misc.h>
 136 #endif
 137 #if ENABLE_FEATURE_USE_SENDFILE
 138 # include <sys/sendfile.h>
 139 #endif
 140 /* amount of buffering in a pipe */
 141 #ifndef PIPE_BUF
 142 # define PIPE_BUF 4096
 143 #endif
 144
 145 #define DEBUG 0
 146
 147 #define IOBUF_SIZE 8192
 148 #if PIPE_BUF >= IOBUF_SIZE
 149 # error "PIPE_BUF >= IOBUF_SIZE"
 150 #endif
 151
 152 #define HEADER_READ_TIMEOUT 60
 153
 154 static const char DEFAULT_PATH_HTTPD_CONF[] ALIGN1 = "/etc";
 155 static const char HTTPD_CONF[] ALIGN1 = "httpd.conf";
 156 static const char HTTP_200[] ALIGN1 = "HTTP/1.0 200 OK\r\n";
 157 static const char index_html[] ALIGN1 = "index.html";
 158
 159 typedef struct has_next_ptr {
 160         struct has_next_ptr *next;
 161 } has_next_ptr;
 162
 163 /* Must have "next" as a first member */
 164 typedef struct Htaccess {
 165         struct Htaccess *next;
 166         char *after_colon;
 167         char before_colon[1];  /* really bigger, must be last */
 168 } Htaccess;
 169
 170 /* Must have "next" as a first member */
 171 typedef struct Htaccess_IP {
 172         struct Htaccess_IP *next;
 173         unsigned ip;
 174         unsigned mask;
 175         int allow_deny;
 176 } Htaccess_IP;
 177
 178 /* Must have "next" as a first member */
 179 typedef struct Htaccess_Proxy {
 180         struct Htaccess_Proxy *next;
 181         char *url_from;
 182         char *host_port;
 183         char *url_to;
 184 } Htaccess_Proxy;
 185
 186 enum {
 187         HTTP_OK = 200,
 188         HTTP_PARTIAL_CONTENT = 206,
 189         HTTP_MOVED_TEMPORARILY = 302,
 190         HTTP_BAD_REQUEST = 400,       /* malformed syntax */
 191         HTTP_UNAUTHORIZED = 401, /* authentication needed, respond with auth hdr */
 192         HTTP_NOT_FOUND = 404,
 193         HTTP_FORBIDDEN = 403,
 194         HTTP_REQUEST_TIMEOUT = 408,
 195         HTTP_NOT_IMPLEMENTED = 501,   /* used for unrecognized requests */
 196         HTTP_INTERNAL_SERVER_ERROR = 500,
 197         HTTP_CONTINUE = 100,
 198 #if 0   /* future use */
 199         HTTP_SWITCHING_PROTOCOLS = 101,
 200         HTTP_CREATED = 201,
 201         HTTP_ACCEPTED = 202,
 202         HTTP_NON_AUTHORITATIVE_INFO = 203,
 203         HTTP_NO_CONTENT = 204,
 204         HTTP_MULTIPLE_CHOICES = 300,
 205         HTTP_MOVED_PERMANENTLY = 301,
 206         HTTP_NOT_MODIFIED = 304,
 207         HTTP_PAYMENT_REQUIRED = 402,
 208         HTTP_BAD_GATEWAY = 502,
 209         HTTP_SERVICE_UNAVAILABLE = 503, /* overload, maintenance */
 210 #endif
 211 };
 212
 213 static const uint16_t http_response_type[] ALIGN2 = {
 214         HTTP_OK,
 215 #if ENABLE_FEATURE_HTTPD_RANGES
 216         HTTP_PARTIAL_CONTENT,
 217 #endif
 218         HTTP_MOVED_TEMPORARILY,
 219         HTTP_REQUEST_TIMEOUT,
 220         HTTP_NOT_IMPLEMENTED,
 221 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
 222         HTTP_UNAUTHORIZED,
 223 #endif
 224         HTTP_NOT_FOUND,
 225         HTTP_BAD_REQUEST,
 226         HTTP_FORBIDDEN,
 227         HTTP_INTERNAL_SERVER_ERROR,
 228 #if 0   /* not implemented */
 229         HTTP_CREATED,
 230         HTTP_ACCEPTED,
 231         HTTP_NO_CONTENT,
 232         HTTP_MULTIPLE_CHOICES,
 233         HTTP_MOVED_PERMANENTLY,
 234         HTTP_NOT_MODIFIED,
 235         HTTP_BAD_GATEWAY,
 236         HTTP_SERVICE_UNAVAILABLE,
 237 #endif
 238 };
 239
 240 static const struct {
 241         const char *name;
 242         const char *info;
 243 } http_response[ARRAY_SIZE(http_response_type)] = {
 244         { "OK", NULL },
 245 #if ENABLE_FEATURE_HTTPD_RANGES
 246         { "Partial Content", NULL },
 247 #endif
 248         { "Found", NULL },
 249         { "Request Timeout", "No request appeared within 60 seconds" },
 250         { "Not Implemented", "The requested method is not recognized" },
 251 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
 252         { "Unauthorized", "" },
 253 #endif
 254         { "Not Found", "The requested URL was not found" },
 255         { "Bad Request", "Unsupported method" },
 256         { "Forbidden", ""  },
 257         { "Internal Server Error", "Internal Server Error" },
 258 #if 0   /* not implemented */
 259         { "Created" },
 260         { "Accepted" },
 261         { "No Content" },
 262         { "Multiple Choices" },
 263         { "Moved Permanently" },
 264         { "Not Modified" },
 265         { "Bad Gateway", "" },
 266         { "Service Unavailable", "" },
 267 #endif
 268 };
 269
 270 struct globals {
 271         int verbose;            /* must be int (used by getopt32) */
 272         smallint flg_deny_all;
 273
 274         unsigned rmt_ip;        /* used for IP-based allow/deny rules */
 275         time_t last_mod;
 276         char *rmt_ip_str;       /* for $REMOTE_ADDR and $REMOTE_PORT */
 277         const char *bind_addr_or_port;
 278
 279         const char *g_query;
 280         const char *opt_c_configFile;
 281         const char *home_httpd;
 282         const char *index_page;
 283
 284         const char *found_mime_type;
 285         const char *found_moved_temporarily;
 286         Htaccess_IP *ip_a_d;    /* config allow/deny lines */
 287
 288         IF_FEATURE_HTTPD_BASIC_AUTH(const char *g_realm;)
 289         IF_FEATURE_HTTPD_BASIC_AUTH(char *remoteuser;)
 290         IF_FEATURE_HTTPD_CGI(char *referer;)
 291         IF_FEATURE_HTTPD_CGI(char *user_agent;)
 292         IF_FEATURE_HTTPD_CGI(char *host;)
 293         IF_FEATURE_HTTPD_CGI(char *http_accept;)
 294         IF_FEATURE_HTTPD_CGI(char *http_accept_language;)
 295
 296         off_t file_size;        /* -1 - unknown */
 297 #if ENABLE_FEATURE_HTTPD_RANGES
 298         off_t range_start;
 299         off_t range_end;
 300         off_t range_len;
 301 #endif
 302
 303 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
 304         Htaccess *g_auth;       /* config user:password lines */
 305 #endif
 306         Htaccess *mime_a;       /* config mime types */
 307 #if ENABLE_FEATURE_HTTPD_CONFIG_WITH_SCRIPT_INTERPR
 308         Htaccess *script_i;     /* config script interpreters */
 309 #endif
 310         char *iobuf;            /* [IOBUF_SIZE] */
 311 #define        hdr_buf bb_common_bufsiz1
 312 #define sizeof_hdr_buf COMMON_BUFSIZE
 313         char *hdr_ptr;
 314         int hdr_cnt;
 315 #if ENABLE_FEATURE_HTTPD_ERROR_PAGES
 316         const char *http_error_page[ARRAY_SIZE(http_response_type)];
 317 #endif
 318 #if ENABLE_FEATURE_HTTPD_PROXY
 319         Htaccess_Proxy *proxy;
 320 #endif
 321 #if ENABLE_FEATURE_HTTPD_GZIP
 322         /* client can handle gzip / we are going to send gzip */
 323         smallint content_gzip;
 324 #endif
 325 };
 326 #define G (*ptr_to_globals)
 327 #define verbose           (G.verbose          )
 328 #define flg_deny_all      (G.flg_deny_all     )
 329 #define rmt_ip            (G.rmt_ip           )
 330 #define bind_addr_or_port (G.bind_addr_or_port)
 331 #define g_query           (G.g_query          )
 332 #define opt_c_configFile  (G.opt_c_configFile )
 333 #define home_httpd        (G.home_httpd       )
 334 #define index_page        (G.index_page       )
 335 #define found_mime_type   (G.found_mime_type  )
 336 #define found_moved_temporarily (G.found_moved_temporarily)
 337 #define last_mod          (G.last_mod         )
 338 #define ip_a_d            (G.ip_a_d           )
 339 #define g_realm           (G.g_realm          )
 340 #define remoteuser        (G.remoteuser       )
 341 #define referer           (G.referer          )
 342 #define user_agent        (G.user_agent       )
 343 #define host              (G.host             )
 344 #define http_accept       (G.http_accept      )
 345 #define http_accept_language (G.http_accept_language)
 346 #define file_size         (G.file_size        )
 347 #if ENABLE_FEATURE_HTTPD_RANGES
 348 #define range_start       (G.range_start      )
 349 #define range_end         (G.range_end        )
 350 #define range_len         (G.range_len        )
 351 #else
 352 enum {
 353         range_start = -1,
 354         range_end = MAXINT(off_t) - 1,
 355         range_len = MAXINT(off_t),
 356 };
 357 #endif
 358 #define rmt_ip_str        (G.rmt_ip_str       )
 359 #define g_auth            (G.g_auth           )
 360 #define mime_a            (G.mime_a           )
 361 #define script_i          (G.script_i         )
 362 #define iobuf             (G.iobuf            )
 363 #define hdr_ptr           (G.hdr_ptr          )
 364 #define hdr_cnt           (G.hdr_cnt          )
 365 #define http_error_page   (G.http_error_page  )
 366 #define proxy             (G.proxy            )
 367 #if ENABLE_FEATURE_HTTPD_GZIP
 368 # define content_gzip     (G.content_gzip     )
 369 #else
 370 # define content_gzip     0
 371 #endif
 372 #define INIT_G() do { \
 373         setup_common_bufsiz(); \
 374         SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
 375         IF_FEATURE_HTTPD_BASIC_AUTH(g_realm = "Web Server Authentication";) \
 376         IF_FEATURE_HTTPD_RANGES(range_start = -1;) \
 377         bind_addr_or_port = "80"; \
 378         index_page = index_html; \
 379         file_size = -1; \
 380 } while (0)
 381
 382
 383 #define STRNCASECMP(a, str) strncasecmp((a), (str), sizeof(str)-1)
 384
 385 /* Prototypes */
 386 enum {
 387         SEND_HEADERS     = (1 << 0),
 388         SEND_BODY        = (1 << 1),
 389         SEND_HEADERS_AND_BODY = SEND_HEADERS + SEND_BODY,
 390 };
 391 static void send_file_and_exit(const char *url, int what) NORETURN;
 392
 393 static void free_llist(has_next_ptr **pptr)
 394 {
 395         has_next_ptr *cur = *pptr;
 396         while (cur) {
 397                 has_next_ptr *t = cur;
 398                 cur = cur->next;
 399                 free(t);
 400         }
 401         *pptr = NULL;
 402 }
 403
 404 static ALWAYS_INLINE void free_Htaccess_list(Htaccess **pptr)
 405 {
 406         free_llist((has_next_ptr**)pptr);
 407 }
 408
 409 static ALWAYS_INLINE void free_Htaccess_IP_list(Htaccess_IP **pptr)
 410 {
 411         free_llist((has_next_ptr**)pptr);
 412 }
 413
 414 /* Returns presumed mask width in bits or < 0 on error.
 415  * Updates strp, stores IP at provided pointer */
 416 static int scan_ip(const char **strp, unsigned *ipp, unsigned char endc)
 417 {
 418         const char *p = *strp;
 419         int auto_mask = 8;
 420         unsigned ip = 0;
 421         int j;
 422
 423         if (*p == '/')
 424                 return -auto_mask;
 425
 426         for (j = 0; j < 4; j++) {
 427                 unsigned octet;
 428
 429                 if ((*p < '0' || *p > '9') && *p != '/' && *p)
 430                         return -auto_mask;
 431                 octet = 0;
 432                 while (*p >= '0' && *p <= '9') {
 433                         octet *= 10;
 434                         octet += *p - '0';
 435                         if (octet > 255)
 436                                 return -auto_mask;
 437                         p++;
 438                 }
 439                 if (*p == '.')
 440                         p++;
 441                 if (*p != '/' && *p)
 442                         auto_mask += 8;
 443                 ip = (ip << 8) | octet;
 444         }
 445         if (*p) {
 446                 if (*p != endc)
 447                         return -auto_mask;
 448                 p++;
 449                 if (*p == '\0')
 450                         return -auto_mask;
 451         }
 452         *ipp = ip;
 453         *strp = p;
 454         return auto_mask;
 455 }
 456
 457 /* Returns 0 on success. Stores IP and mask at provided pointers */
 458 static int scan_ip_mask(const char *str, unsigned *ipp, unsigned *maskp)
 459 {
 460         int i;
 461         unsigned mask;
 462         char *p;
 463
 464         i = scan_ip(&str, ipp, '/');
 465         if (i < 0)
 466                 return i;
 467
 468         if (*str) {
 469                 /* there is /xxx after dotted-IP address */
 470                 i = bb_strtou(str, &p, 10);
 471                 if (*p == '.') {
 472                         /* 'xxx' itself is dotted-IP mask, parse it */
 473                         /* (return 0 (success) only if it has N.N.N.N form) */
 474                         return scan_ip(&str, maskp, '\0') - 32;
 475                 }
 476                 if (*p)
 477                         return -1;
 478         }
 479
 480         if (i > 32)
 481                 return -1;
 482
 483         if (sizeof(unsigned) == 4 && i == 32) {
 484                 /* mask >>= 32 below may not work */
 485                 mask = 0;
 486         } else {
 487                 mask = 0xffffffff;
 488                 mask >>= i;
 489         }
 490         /* i == 0 -> *maskp = 0x00000000
 491          * i == 1 -> *maskp = 0x80000000
 492          * i == 4 -> *maskp = 0xf0000000
 493          * i == 31 -> *maskp = 0xfffffffe
 494          * i == 32 -> *maskp = 0xffffffff */
 495         *maskp = (uint32_t)(~mask);
 496         return 0;
 497 }
 498
 499 /*
 500  * Parse configuration file into in-memory linked list.
 501  *
 502  * Any previous IP rules are discarded.
 503  * If the flag argument is not SUBDIR_PARSE then all /path and mime rules
 504  * are also discarded.  That is, previous settings are retained if flag is
 505  * SUBDIR_PARSE.
 506  * Error pages are only parsed on the main config file.
 507  *
 508  * path   Path where to look for httpd.conf (without filename).
 509  * flag   Type of the parse request.
 510  */
 511 /* flag param: */
 512 enum {
 513         FIRST_PARSE    = 0, /* path will be "/etc" */
 514         SIGNALED_PARSE = 1, /* path will be "/etc" */
 515         SUBDIR_PARSE   = 2, /* path will be derived from URL */
 516 };
 517 static void parse_conf(const char *path, int flag)
 518 {
 519         /* internally used extra flag state */
 520         enum { TRY_CURDIR_PARSE = 3 };
 521
 522         FILE *f;
 523         const char *filename;
 524         char buf[160];
 525
 526         /* discard old rules */
 527         free_Htaccess_IP_list(&ip_a_d);
 528         flg_deny_all = 0;
 529         /* retain previous auth and mime config only for subdir parse */
 530         if (flag != SUBDIR_PARSE) {
 531                 free_Htaccess_list(&mime_a);
 532 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
 533                 free_Htaccess_list(&g_auth);
 534 #endif
 535 #if ENABLE_FEATURE_HTTPD_CONFIG_WITH_SCRIPT_INTERPR
 536                 free_Htaccess_list(&script_i);
 537 #endif
 538         }
 539
 540         filename = opt_c_configFile;
 541         if (flag == SUBDIR_PARSE || filename == NULL) {
 542                 filename = alloca(strlen(path) + sizeof(HTTPD_CONF) + 2);
 543                 sprintf((char *)filename, "%s/%s", path, HTTPD_CONF);
 544         }
 545
 546         while ((f = fopen_for_read(filename)) == NULL) {
 547                 if (flag >= SUBDIR_PARSE) { /* SUBDIR or TRY_CURDIR */
 548                         /* config file not found, no changes to config */
 549                         return;
 550                 }
 551                 if (flag == FIRST_PARSE) {
 552                         /* -c CONFFILE given, but CONFFILE doesn't exist? */
 553                         if (opt_c_configFile)
 554                                 bb_simple_perror_msg_and_die(opt_c_configFile);
 555                         /* else: no -c, thus we looked at /etc/httpd.conf,
 556                          * and it's not there. try ./httpd.conf: */
 557                 }
 558                 flag = TRY_CURDIR_PARSE;
 559                 filename = HTTPD_CONF;
 560         }
 561
 562 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
 563         /* in "/file:user:pass" lines, we prepend path in subdirs */
 564         if (flag != SUBDIR_PARSE)
 565                 path = "";
 566 #endif
 567         /* The lines can be:
 568          *
 569          * I:default_index_file
 570          * H:http_home
 571          * [AD]:IP[/mask]   # allow/deny, * for wildcard
 572          * Ennn:error.html  # error page for status nnn
 573          * P:/url:[http://]hostname[:port]/new/path # reverse proxy
 574          * .ext:mime/type   # mime type
 575          * *.php:/path/php  # run xxx.php through an interpreter
 576          * /file:user:pass  # username and password
 577          */
 578         while (fgets(buf, sizeof(buf), f) != NULL) {
 579                 unsigned strlen_buf;
 580                 unsigned char ch;
 581                 char *after_colon;
 582
 583                 { /* remove all whitespace, and # comments */
 584                         char *p, *p0;
 585
 586                         p0 = buf;
 587                         /* skip non-whitespace beginning. Often the whole line
 588                          * is non-whitespace. We want this case to work fast,
 589                          * without needless copying, therefore we don't merge
 590                          * this operation into next while loop. */
 591                         while ((ch = *p0) != '\0' && ch != '\n' && ch != '#'
 592                          && ch != ' ' && ch != '\t'
 593                         ) {
 594                                 p0++;
 595                         }
 596                         p = p0;
 597                         /* if we enter this loop, we have some whitespace.
 598                          * discard it */
 599                         while (ch != '\0' && ch != '\n' && ch != '#') {
 600                                 if (ch != ' ' && ch != '\t') {
 601                                         *p++ = ch;
 602                                 }
 603                                 ch = *++p0;
 604                         }
 605                         *p = '\0';
 606                         strlen_buf = p - buf;
 607                         if (strlen_buf == 0)
 608                                 continue; /* empty line */
 609                 }
 610
 611                 after_colon = strchr(buf, ':');
 612                 /* strange line? */
 613                 if (after_colon == NULL || *++after_colon == '\0')
 614                         goto config_error;
 615
 616                 ch = (buf[0] & ~0x20); /* toupper if it's a letter */
 617
 618                 if (ch == 'I') {
 619                         if (index_page != index_html)
 620                                 free((char*)index_page);
 621                         index_page = xstrdup(after_colon);
 622                         continue;
 623                 }
 624
 625                 /* do not allow jumping around using H in subdir's configs */
 626                 if (flag == FIRST_PARSE && ch == 'H') {
 627                         home_httpd = xstrdup(after_colon);
 628                         xchdir(home_httpd);
 629                         continue;
 630                 }
 631
 632                 if (ch == 'A' || ch == 'D') {
 633                         Htaccess_IP *pip;
 634
 635                         if (*after_colon == '*') {
 636                                 if (ch == 'D') {
 637                                         /* memorize "deny all" */
 638                                         flg_deny_all = 1;
 639                                 }
 640                                 /* skip assumed "A:*", it is a default anyway */
 641                                 continue;
 642                         }
 643                         /* store "allow/deny IP/mask" line */
 644                         pip = xzalloc(sizeof(*pip));
 645                         if (scan_ip_mask(after_colon, &pip->ip, &pip->mask)) {
 646                                 /* IP{/mask} syntax error detected, protect all */
 647                                 ch = 'D';
 648                                 pip->mask = 0;
 649                         }
 650                         pip->allow_deny = ch;
 651                         if (ch == 'D') {
 652                                 /* Deny:from_IP - prepend */
 653                                 pip->next = ip_a_d;
 654                                 ip_a_d = pip;
 655                         } else {
 656                                 /* A:from_IP - append (thus all D's precedes A's) */
 657                                 Htaccess_IP *prev_IP = ip_a_d;
 658                                 if (prev_IP == NULL) {
 659                                         ip_a_d = pip;
 660                                 } else {
 661                                         while (prev_IP->next)
 662                                                 prev_IP = prev_IP->next;
 663                                         prev_IP->next = pip;
 664                                 }
 665                         }
 666                         continue;
 667                 }
 668
 669 #if ENABLE_FEATURE_HTTPD_ERROR_PAGES
 670                 if (flag == FIRST_PARSE && ch == 'E') {
 671                         unsigned i;
 672                         int status = atoi(buf + 1); /* error status code */
 673
 674                         if (status < HTTP_CONTINUE) {
 675                                 goto config_error;
 676                         }
 677                         /* then error page; find matching status */
 678                         for (i = 0; i < ARRAY_SIZE(http_response_type); i++) {
 679                                 if (http_response_type[i] == status) {
 680                                         /* We chdir to home_httpd, thus no need to
 681                                          * concat_path_file(home_httpd, after_colon)
 682                                          * here */
 683                                         http_error_page[i] = xstrdup(after_colon);
 684                                         break;
 685                                 }
 686                         }
 687                         continue;
 688                 }
 689 #endif
 690
 691 #if ENABLE_FEATURE_HTTPD_PROXY
 692                 if (flag == FIRST_PARSE && ch == 'P') {
 693                         /* P:/url:[http://]hostname[:port]/new/path */
 694                         char *url_from, *host_port, *url_to;
 695                         Htaccess_Proxy *proxy_entry;
 696
 697                         url_from = after_colon;
 698                         host_port = strchr(after_colon, ':');
 699                         if (host_port == NULL) {
 700                                 goto config_error;
 701                         }
 702                         *host_port++ = '\0';
 703                         if (is_prefixed_with(host_port, "http://"))
 704                                 host_port += 7;
 705                         if (*host_port == '\0') {
 706                                 goto config_error;
 707                         }
 708                         url_to = strchr(host_port, '/');
 709                         if (url_to == NULL) {
 710                                 goto config_error;
 711                         }
 712                         *url_to = '\0';
 713                         proxy_entry = xzalloc(sizeof(*proxy_entry));
 714                         proxy_entry->url_from = xstrdup(url_from);
 715                         proxy_entry->host_port = xstrdup(host_port);
 716                         *url_to = '/';
 717                         proxy_entry->url_to = xstrdup(url_to);
 718                         proxy_entry->next = proxy;
 719                         proxy = proxy_entry;
 720                         continue;
 721                 }
 722 #endif
 723                 /* the rest of directives are non-alphabetic,
 724                  * must avoid using "toupper'ed" ch */
 725                 ch = buf[0];
 726
 727                 if (ch == '.' /* ".ext:mime/type" */
 728 #if ENABLE_FEATURE_HTTPD_CONFIG_WITH_SCRIPT_INTERPR
 729                  || (ch == '*' && buf[1] == '.') /* "*.php:/path/php" */
 730 #endif
 731                 ) {
 732                         char *p;
 733                         Htaccess *cur;
 734
 735                         cur = xzalloc(sizeof(*cur) /* includes space for NUL */ + strlen_buf);
 736                         strcpy(cur->before_colon, buf);
 737                         p = cur->before_colon + (after_colon - buf);
 738                         p[-1] = '\0';
 739                         cur->after_colon = p;
 740                         if (ch == '.') {
 741                                 /* .mime line: prepend to mime_a list */
 742                                 cur->next = mime_a;
 743                                 mime_a = cur;
 744                         }
 745 #if ENABLE_FEATURE_HTTPD_CONFIG_WITH_SCRIPT_INTERPR
 746                         else {
 747                                 /* script interpreter line: prepend to script_i list */
 748                                 cur->next = script_i;
 749                                 script_i = cur;
 750                         }
 751 #endif
 752                         continue;
 753                 }
 754
 755 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
 756                 if (ch == '/') { /* "/file:user:pass" */
 757                         char *p;
 758                         Htaccess *cur;
 759                         unsigned file_len;
 760
 761                         /* note: path is "" unless we are in SUBDIR parse,
 762                          * otherwise it does NOT start with "/" */
 763                         cur = xzalloc(sizeof(*cur) /* includes space for NUL */
 764                                 + 1 + strlen(path)
 765                                 + strlen_buf
 766                                 );
 767                         /* form "/path/file" */
 768                         sprintf(cur->before_colon, "/%s%.*s",
 769                                 path,
 770                                 (int) (after_colon - buf - 1), /* includes "/", but not ":" */
 771                                 buf);
 772                         /* canonicalize it */
 773                         p = bb_simplify_abs_path_inplace(cur->before_colon);
 774                         file_len = p - cur->before_colon;
 775                         /* add "user:pass" after NUL */
 776                         strcpy(++p, after_colon);
 777                         cur->after_colon = p;
 778
 779                         /* insert cur into g_auth */
 780                         /* g_auth is sorted by decreased filename length */
 781                         {
 782                                 Htaccess *auth, **authp;
 783
 784                                 authp = &g_auth;
 785                                 while ((auth = *authp) != NULL) {
 786                                         if (file_len >= strlen(auth->before_colon)) {
 787                                                 /* insert cur before auth */
 788                                                 cur->next = auth;
 789                                                 break;
 790                                         }
 791                                         authp = &auth->next;
 792                                 }
 793                                 *authp = cur;
 794                         }
 795                         continue;
 796                 }
 797 #endif /* BASIC_AUTH */
 798
 799                 /* the line is not recognized */
 800  config_error:
 801                 bb_error_msg("config error '%s' in '%s'", buf, filename);
 802         } /* while (fgets) */
 803
 804         fclose(f);
 805 }
 806
 807 #if ENABLE_FEATURE_HTTPD_ENCODE_URL_STR
 808 /*
 809  * Given a string, html-encode special characters.
 810  * This is used for the -e command line option to provide an easy way
 811  * for scripts to encode result data without confusing browsers.  The
 812  * returned string pointer is memory allocated by malloc().
 813  *
 814  * Returns a pointer to the encoded string (malloced).
 815  */
 816 static char *encodeString(const char *string)
 817 {
 818         /* take the simple route and encode everything */
 819         /* could possibly scan once to get length.     */
 820         int len = strlen(string);
 821         char *out = xmalloc(len * 6 + 1);
 822         char *p = out;
 823         char ch;
 824
 825         while ((ch = *string++) != '\0') {
 826                 /* very simple check for what to encode */
 827                 if (isalnum(ch))
 828                         *p++ = ch;
 829                 else
 830                         p += sprintf(p, "&#%d;", (unsigned char) ch);
 831         }
 832         *p = '\0';
 833         return out;
 834 }
 835 #endif
 836
 837 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
 838 /*
 839  * Decode a base64 data stream as per rfc1521.
 840  * Note that the rfc states that non base64 chars are to be ignored.
 841  * Since the decode always results in a shorter size than the input,
 842  * it is OK to pass the input arg as an output arg.
 843  * Parameter: a pointer to a base64 encoded string.
 844  * Decoded data is stored in-place.
 845  */
 846 static void decodeBase64(char *Data)
 847 {
 848         const unsigned char *in = (const unsigned char *)Data;
 849         /* The decoded size will be at most 3/4 the size of the encoded */
 850         unsigned ch = 0;
 851         int i = 0;
 852
 853         while (*in) {
 854                 int t = *in++;
 855
 856                 if (t >= '0' && t <= '9')
 857                         t = t - '0' + 52;
 858                 else if (t >= 'A' && t <= 'Z')
 859                         t = t - 'A';
 860                 else if (t >= 'a' && t <= 'z')
 861                         t = t - 'a' + 26;
 862                 else if (t == '+')
 863                         t = 62;
 864                 else if (t == '/')
 865                         t = 63;
 866                 else if (t == '=')
 867                         t = 0;
 868                 else
 869                         continue;
 870
 871                 ch = (ch << 6) | t;
 872                 i++;
 873                 if (i == 4) {
 874                         *Data++ = (char) (ch >> 16);
 875                         *Data++ = (char) (ch >> 8);
 876                         *Data++ = (char) ch;
 877                         i = 0;
 878                 }
 879         }
 880         *Data = '\0';
 881 }
 882 #endif
 883
 884 /*
 885  * Create a listen server socket on the designated port.
 886  */
 887 static int openServer(void)
 888 {
 889         unsigned n = bb_strtou(bind_addr_or_port, NULL, 10);
 890         if (!errno && n && n <= 0xffff)
 891                 n = create_and_bind_stream_or_die(NULL, n);
 892         else
 893                 n = create_and_bind_stream_or_die(bind_addr_or_port, 80);
 894         xlisten(n, 9);
 895         return n;
 896 }
 897
 898 /*
 899  * Log the connection closure and exit.
 900  */
 901 static void log_and_exit(void) NORETURN;
 902 static void log_and_exit(void)
 903 {
 904         /* Paranoia. IE said to be buggy. It may send some extra data
 905          * or be confused by us just exiting without SHUT_WR. Oh well. */
 906         shutdown(1, SHUT_WR);
 907         /* Why??
 908         (this also messes up stdin when user runs httpd -i from terminal)
 909         ndelay_on(0);
 910         while (read(STDIN_FILENO, iobuf, IOBUF_SIZE) > 0)
 911                 continue;
 912         */
 913
 914         if (verbose > 2)
 915                 bb_error_msg("closed");
 916         _exit(xfunc_error_retval);
 917 }
 918
 919 /*
 920  * Create and send HTTP response headers.
 921  * The arguments are combined and sent as one write operation.  Note that
 922  * IE will puke big-time if the headers are not sent in one packet and the
 923  * second packet is delayed for any reason.
 924  * responseNum - the result code to send.
 925  */
 926 static void send_headers(int responseNum)
 927 {
 928         static const char RFC1123FMT[] ALIGN1 = "%a, %d %b %Y %H:%M:%S GMT";
 929
 930         const char *responseString = "";
 931         const char *infoString = NULL;
 932         const char *mime_type;
 933 #if ENABLE_FEATURE_HTTPD_ERROR_PAGES
 934         const char *error_page = NULL;
 935 #endif
 936         unsigned i;
 937         time_t timer = time(NULL);
 938         char tmp_str[80];
 939         int len;
 940
 941         for (i = 0; i < ARRAY_SIZE(http_response_type); i++) {
 942                 if (http_response_type[i] == responseNum) {
 943                         responseString = http_response[i].name;
 944                         infoString = http_response[i].info;
 945 #if ENABLE_FEATURE_HTTPD_ERROR_PAGES
 946                         error_page = http_error_page[i];
 947 #endif
 948                         break;
 949                 }
 950         }
 951         /* error message is HTML */
 952         mime_type = responseNum == HTTP_OK ?
 953                                 found_mime_type : "text/html";
 954
 955         if (verbose)
 956                 bb_error_msg("response:%u", responseNum);
 957
 958         /* emit the current date */
 959         strftime(tmp_str, sizeof(tmp_str), RFC1123FMT, gmtime(&timer));
 960         len = sprintf(iobuf,
 961                         "HTTP/1.0 %d %s\r\nContent-type: %s\r\n"
 962                         "Date: %s\r\nConnection: close\r\n",
 963                         responseNum, responseString, mime_type, tmp_str);
 964
 965 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
 966         if (responseNum == HTTP_UNAUTHORIZED) {
 967                 len += sprintf(iobuf + len,
 968                                 "WWW-Authenticate: Basic realm=\"%s\"\r\n",
 969                                 g_realm);
 970         }
 971 #endif
 972         if (responseNum == HTTP_MOVED_TEMPORARILY) {
 973                 /* Responding to "GET /dir" with
 974                  * "HTTP/1.0 302 Found" "Location: /dir/"
 975                  * - IOW, asking them to repeat with a slash.
 976                  * Here, overflow IS possible, can't use sprintf:
 977                  * mkdir test
 978                  * python -c 'print("get /test?" + ("x" * 8192))' | busybox httpd -i -h .
 979                  */
 980                 len += snprintf(iobuf + len, IOBUF_SIZE-3 - len,
 981                                 "Location: %s/%s%s\r\n",
 982                                 found_moved_temporarily,
 983                                 (g_query ? "?" : ""),
 984                                 (g_query ? g_query : ""));
 985                 if (len > IOBUF_SIZE-3)
 986                         len = IOBUF_SIZE-3;
 987         }
 988
 989 #if ENABLE_FEATURE_HTTPD_ERROR_PAGES
 990         if (error_page && access(error_page, R_OK) == 0) {
 991                 iobuf[len++] = '\r';
 992                 iobuf[len++] = '\n';
 993                 if (DEBUG) {
 994                         iobuf[len] = '\0';
 995                         fprintf(stderr, "headers: '%s'\n", iobuf);
 996                 }
 997                 full_write(STDOUT_FILENO, iobuf, len);
 998                 if (DEBUG)
 999                         fprintf(stderr, "writing error page: '%s'\n", error_page);
1000                 return send_file_and_exit(error_page, SEND_BODY);
1001         }
1002 #endif
1003
1004         if (file_size != -1) {    /* file */
1005                 strftime(tmp_str, sizeof(tmp_str), RFC1123FMT, gmtime(&last_mod));
1006 #if ENABLE_FEATURE_HTTPD_RANGES
1007                 if (responseNum == HTTP_PARTIAL_CONTENT) {
1008                         len += sprintf(iobuf + len, "Content-Range: bytes %"OFF_FMT"u-%"OFF_FMT"u/%"OFF_FMT"u\r\n",
1009                                         range_start,
1010                                         range_end,
1011                                         file_size);
1012                         file_size = range_end - range_start + 1;
1013                 }
1014 #endif
1015                 len += sprintf(iobuf + len,
1016 #if ENABLE_FEATURE_HTTPD_RANGES
1017                         "Accept-Ranges: bytes\r\n"
1018 #endif
1019                         "Last-Modified: %s\r\n%s %"OFF_FMT"u\r\n",
1020                                 tmp_str,
1021                                 content_gzip ? "Transfer-length:" : "Content-length:",
1022                                 file_size
1023                 );
1024         }
1025
1026         if (content_gzip)
1027                 len += sprintf(iobuf + len, "Content-Encoding: gzip\r\n");
1028
1029         iobuf[len++] = '\r';
1030         iobuf[len++] = '\n';
1031         if (infoString) {
1032                 len += sprintf(iobuf + len,
1033                                 "<HTML><HEAD><TITLE>%d %s</TITLE></HEAD>\n"
1034                                 "<BODY><H1>%d %s</H1>\n%s\n</BODY></HTML>\n",
1035                                 responseNum, responseString,
1036                                 responseNum, responseString, infoString);
1037         }
1038         if (DEBUG) {
1039                 iobuf[len] = '\0';
1040                 fprintf(stderr, "headers: '%s'\n", iobuf);
1041         }
1042         if (full_write(STDOUT_FILENO, iobuf, len) != len) {
1043                 if (verbose > 1)
1044                         bb_perror_msg("error");
1045                 log_and_exit();
1046         }
1047 }
1048
1049 static void send_headers_and_exit(int responseNum) NORETURN;
1050 static void send_headers_and_exit(int responseNum)
1051 {
1052         IF_FEATURE_HTTPD_GZIP(content_gzip = 0;)
1053         send_headers(responseNum);
1054         log_and_exit();
1055 }
1056
1057 /*
1058  * Read from the socket until '\n' or EOF. '\r' chars are removed.
1059  * '\n' is replaced with NUL.
1060  * Return number of characters read or 0 if nothing is read
1061  * ('\r' and '\n' are not counted).
1062  * Data is returned in iobuf.
1063  */
1064 static int get_line(void)
1065 {
1066         int count = 0;
1067         char c;
1068
1069         alarm(HEADER_READ_TIMEOUT);
1070         while (1) {
1071                 if (hdr_cnt <= 0) {
1072                         hdr_cnt = safe_read(STDIN_FILENO, hdr_buf, sizeof_hdr_buf);
1073                         if (hdr_cnt <= 0)
1074                                 break;
1075                         hdr_ptr = hdr_buf;
1076                 }
1077                 iobuf[count] = c = *hdr_ptr++;
1078                 hdr_cnt--;
1079
1080                 if (c == '\r')
1081                         continue;
1082                 if (c == '\n') {
1083                         iobuf[count] = '\0';
1084                         break;
1085                 }
1086                 if (count < (IOBUF_SIZE - 1))      /* check overflow */
1087                         count++;
1088         }
1089         return count;
1090 }
1091
1092 #if ENABLE_FEATURE_HTTPD_CGI || ENABLE_FEATURE_HTTPD_PROXY
1093
1094 /* gcc 4.2.1 fares better with NOINLINE */
1095 static NOINLINE void cgi_io_loop_and_exit(int fromCgi_rd, int toCgi_wr, int post_len) NORETURN;
1096 static NOINLINE void cgi_io_loop_and_exit(int fromCgi_rd, int toCgi_wr, int post_len)
1097 {
1098         enum { FROM_CGI = 1, TO_CGI = 2 }; /* indexes in pfd[] */
1099         struct pollfd pfd[3];
1100         int out_cnt; /* we buffer a bit of initial CGI output */
1101         int count;
1102
1103         /* iobuf is used for CGI -> network data,
1104          * hdr_buf is for network -> CGI data (POSTDATA) */
1105
1106         /* If CGI dies, we still want to correctly finish reading its output
1107          * and send it to the peer. So please no SIGPIPEs! */
1108         signal(SIGPIPE, SIG_IGN);
1109
1110         // We inconsistently handle a case when more POSTDATA from network
1111         // is coming than we expected. We may give *some part* of that
1112         // extra data to CGI.
1113
1114         //if (hdr_cnt > post_len) {
1115         //      /* We got more POSTDATA from network than we expected */
1116         //      hdr_cnt = post_len;
1117         //}
1118         post_len -= hdr_cnt;
1119         /* post_len - number of POST bytes not yet read from network */
1120
1121         /* NB: breaking out of this loop jumps to log_and_exit() */
1122         out_cnt = 0;
1123         pfd[FROM_CGI].fd = fromCgi_rd;
1124         pfd[FROM_CGI].events = POLLIN;
1125         pfd[TO_CGI].fd = toCgi_wr;
1126         while (1) {
1127                 /* Note: even pfd[0].events == 0 won't prevent
1128                  * revents == POLLHUP|POLLERR reports from closed stdin.
1129                  * Setting fd to -1 works: */
1130                 pfd[0].fd = -1;
1131                 pfd[0].events = POLLIN;
1132                 pfd[0].revents = 0; /* probably not needed, paranoia */
1133
1134                 /* We always poll this fd, thus kernel always sets revents: */
1135                 /*pfd[FROM_CGI].events = POLLIN; - moved out of loop */
1136                 /*pfd[FROM_CGI].revents = 0; - not needed */
1137
1138                 /* gcc-4.8.0 still doesnt fill two shorts with one insn :( */
1139                 /* http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47059 */
1140                 /* hopefully one day it will... */
1141                 pfd[TO_CGI].events = POLLOUT;
1142                 pfd[TO_CGI].revents = 0; /* needed! */
1143
1144                 if (toCgi_wr && hdr_cnt <= 0) {
1145                         if (post_len > 0) {
1146                                 /* Expect more POST data from network */
1147                                 pfd[0].fd = 0;
1148                         } else {
1149                                 /* post_len <= 0 && hdr_cnt <= 0:
1150                                  * no more POST data to CGI,
1151                                  * let CGI see EOF on CGI's stdin */
1152                                 if (toCgi_wr != fromCgi_rd)
1153                                         close(toCgi_wr);
1154                                 toCgi_wr = 0;
1155                         }
1156                 }
1157
1158                 /* Now wait on the set of sockets */
1159                 count = safe_poll(pfd, hdr_cnt > 0 ? TO_CGI+1 : FROM_CGI+1, -1);
1160                 if (count <= 0) {
1161 #if 0
1162                         if (safe_waitpid(pid, &status, WNOHANG) <= 0) {
1163                                 /* Weird. CGI didn't exit and no fd's
1164                                  * are ready, yet poll returned?! */
1165                                 continue;
1166                         }
1167                         if (DEBUG && WIFEXITED(status))
1168                                 bb_error_msg("CGI exited, status=%d", WEXITSTATUS(status));
1169                         if (DEBUG && WIFSIGNALED(status))
1170                                 bb_error_msg("CGI killed, signal=%d", WTERMSIG(status));
1171 #endif
1172                         break;
1173                 }
1174
1175                 if (pfd[TO_CGI].revents) {
1176                         /* hdr_cnt > 0 here due to the way poll() called */
1177                         /* Have data from peer and can write to CGI */
1178                         count = safe_write(toCgi_wr, hdr_ptr, hdr_cnt);
1179                         /* Doesn't happen, we dont use nonblocking IO here
1180                          *if (count < 0 && errno == EAGAIN) {
1181                          *      ...
1182                          *} else */
1183                         if (count > 0) {
1184                                 hdr_ptr += count;
1185                                 hdr_cnt -= count;
1186                         } else {
1187                                 /* EOF/broken pipe to CGI, stop piping POST data */
1188                                 hdr_cnt = post_len = 0;
1189                         }
1190                 }
1191
1192                 if (pfd[0].revents) {
1193                         /* post_len > 0 && hdr_cnt == 0 here */
1194                         /* We expect data, prev data portion is eaten by CGI
1195                          * and there *is* data to read from the peer
1196                          * (POSTDATA) */
1197                         //count = post_len > (int)sizeof_hdr_buf ? (int)sizeof_hdr_buf : post_len;
1198                         //count = safe_read(STDIN_FILENO, hdr_buf, count);
1199                         count = safe_read(STDIN_FILENO, hdr_buf, sizeof_hdr_buf);
1200                         if (count > 0) {
1201                                 hdr_cnt = count;
1202                                 hdr_ptr = hdr_buf;
1203                                 post_len -= count;
1204                         } else {
1205                                 /* no more POST data can be read */
1206                                 post_len = 0;
1207                         }
1208                 }
1209
1210                 if (pfd[FROM_CGI].revents) {
1211                         /* There is something to read from CGI */
1212                         char *rbuf = iobuf;
1213
1214                         /* Are we still buffering CGI output? */
1215                         if (out_cnt >= 0) {
1216                                 /* HTTP_200[] has single "\r\n" at the end.
1217                                  * According to http://hoohoo.ncsa.uiuc.edu/cgi/out.html,
1218                                  * CGI scripts MUST send their own header terminated by
1219                                  * empty line, then data. That's why we have only one
1220                                  * <cr><lf> pair here. We will output "200 OK" line
1221                                  * if needed, but CGI still has to provide blank line
1222                                  * between header and body */
1223
1224                                 /* Must use safe_read, not full_read, because
1225                                  * CGI may output a few first bytes and then wait
1226                                  * for POSTDATA without closing stdout.
1227                                  * With full_read we may wait here forever. */
1228                                 count = safe_read(fromCgi_rd, rbuf + out_cnt, PIPE_BUF - 8);
1229                                 if (count <= 0) {
1230                                         /* eof (or error) and there was no "HTTP",
1231                                          * so write it, then write received data */
1232                                         if (out_cnt) {
1233                                                 full_write(STDOUT_FILENO, HTTP_200, sizeof(HTTP_200)-1);
1234                                                 full_write(STDOUT_FILENO, rbuf, out_cnt);
1235                                         }
1236                                         break; /* CGI stdout is closed, exiting */
1237                                 }
1238                                 out_cnt += count;
1239                                 count = 0;
1240                                 /* "Status" header format is: "Status: 302 Redirected\r\n" */
1241                                 if (out_cnt >= 7 && memcmp(rbuf, "Status:", 7) == 0) {
1242                                         /* send "HTTP/1.0 " */
1243                                         if (full_write(STDOUT_FILENO, HTTP_200, 9) != 9)
1244                                                 break;
1245                                         rbuf += 7; /* skip "Status:" */
1246                                         count = out_cnt - 7;
1247                                         out_cnt = -1; /* buffering off */
1248                                 } else if (out_cnt >= 4) {
1249                                         /* Did CGI add "HTTP"? */
1250                                         if (memcmp(rbuf, HTTP_200, 4) != 0) {
1251                                                 /* there is no "HTTP", do it ourself */
1252                                                 if (full_write(STDOUT_FILENO, HTTP_200, sizeof(HTTP_200)-1) != sizeof(HTTP_200)-1)
1253                                                         break;
1254                                         }
1255                                         /* Commented out:
1256                                         if (!strstr(rbuf, "ontent-")) {
1257                                                 full_write(s, "Content-type: text/plain\r\n\r\n", 28);
1258                                         }
1259                                          * Counter-example of valid CGI without Content-type:
1260                                          * echo -en "HTTP/1.0 302 Found\r\n"
1261                                          * echo -en "Location: http://www.busybox.net\r\n"
1262                                          * echo -en "\r\n"
1263                                          */
1264                                         count = out_cnt;
1265                                         out_cnt = -1; /* buffering off */
1266                                 }
1267                         } else {
1268                                 count = safe_read(fromCgi_rd, rbuf, PIPE_BUF);
1269                                 if (count <= 0)
1270                                         break;  /* eof (or error) */
1271                         }
1272                         if (full_write(STDOUT_FILENO, rbuf, count) != count)
1273                                 break;
1274                         if (DEBUG)
1275                                 fprintf(stderr, "cgi read %d bytes: '%.*s'\n", count, count, rbuf);
1276                 } /* if (pfd[FROM_CGI].revents) */
1277         } /* while (1) */
1278         log_and_exit();
1279 }
1280 #endif
1281
1282 #if ENABLE_FEATURE_HTTPD_CGI
1283
1284 static void setenv1(const char *name, const char *value)
1285 {
1286         setenv(name, value ? value : "", 1);
1287 }
1288
1289 /*
1290  * Spawn CGI script, forward CGI's stdin/out <=> network
1291  *
1292  * Environment variables are set up and the script is invoked with pipes
1293  * for stdin/stdout.  If a POST is being done the script is fed the POST
1294  * data in addition to setting the QUERY_STRING variable (for GETs or POSTs).
1295  *
1296  * Parameters:
1297  * const char *url              The requested URL (with leading /).
1298  * const char *orig_uri         The original URI before rewriting (if any)
1299  * int post_len                 Length of the POST body.
1300  * const char *cookie           For set HTTP_COOKIE.
1301  * const char *content_type     For set CONTENT_TYPE.
1302  */
1303 static void send_cgi_and_exit(
1304                 const char *url,
1305                 const char *orig_uri,
1306                 const char *request,
1307                 int post_len,
1308                 const char *cookie,
1309                 const char *content_type) NORETURN;
1310 static void send_cgi_and_exit(
1311                 const char *url,
1312                 const char *orig_uri,
1313                 const char *request,
1314                 int post_len,
1315                 const char *cookie,
1316                 const char *content_type)
1317 {
1318         struct fd_pair fromCgi;  /* CGI -> httpd pipe */
1319         struct fd_pair toCgi;    /* httpd -> CGI pipe */
1320         char *script, *last_slash;
1321         int pid;
1322
1323         /* Make a copy. NB: caller guarantees:
1324          * url[0] == '/', url[1] != '/' */
1325         url = xstrdup(url);
1326
1327         /*
1328          * We are mucking with environment _first_ and then vfork/exec,
1329          * this allows us to use vfork safely. Parent doesn't care about
1330          * these environment changes anyway.
1331          */
1332
1333         /* Check for [dirs/]script.cgi/PATH_INFO */
1334         last_slash = script = (char*)url;
1335         while ((script = strchr(script + 1, '/')) != NULL) {
1336                 int dir;
1337                 *script = '\0';
1338                 dir = is_directory(url + 1, /*followlinks:*/ 1);
1339                 *script = '/';
1340                 if (!dir) {
1341                         /* not directory, found script.cgi/PATH_INFO */
1342                         break;
1343                 }
1344                 /* is directory, find next '/' */
1345                 last_slash = script;
1346         }
1347         setenv1("PATH_INFO", script);   /* set to /PATH_INFO or "" */
1348         setenv1("REQUEST_METHOD", request);
1349         if (g_query) {
1350                 putenv(xasprintf("%s=%s?%s", "REQUEST_URI", orig_uri, g_query));
1351         } else {
1352                 setenv1("REQUEST_URI", orig_uri);
1353         }
1354         if (script != NULL)
1355                 *script = '\0';         /* cut off /PATH_INFO */
1356
1357         /* SCRIPT_FILENAME is required by PHP in CGI mode */
1358         if (home_httpd[0] == '/') {
1359                 char *fullpath = concat_path_file(home_httpd, url);
1360                 setenv1("SCRIPT_FILENAME", fullpath);
1361         }
1362         /* set SCRIPT_NAME as full path: /cgi-bin/dirs/script.cgi */
1363         setenv1("SCRIPT_NAME", url);
1364         /* http://hoohoo.ncsa.uiuc.edu/cgi/env.html:
1365          * QUERY_STRING: The information which follows the ? in the URL
1366          * which referenced this script. This is the query information.
1367          * It should not be decoded in any fashion. This variable
1368          * should always be set when there is query information,
1369          * regardless of command line decoding. */
1370         /* (Older versions of bbox seem to do some decoding) */
1371         setenv1("QUERY_STRING", g_query);
1372         putenv((char*)"SERVER_SOFTWARE=busybox httpd/"BB_VER);
1373         putenv((char*)"SERVER_PROTOCOL=HTTP/1.0");
1374         putenv((char*)"GATEWAY_INTERFACE=CGI/1.1");
1375         /* Having _separate_ variables for IP and port defeats
1376          * the purpose of having socket abstraction. Which "port"
1377          * are you using on Unix domain socket?
1378          * IOW - REMOTE_PEER="1.2.3.4:56" makes much more sense.
1379          * Oh well... */
1380         {
1381                 char *p = rmt_ip_str ? rmt_ip_str : (char*)"";
1382                 char *cp = strrchr(p, ':');
1383                 if (ENABLE_FEATURE_IPV6 && cp && strchr(cp, ']'))
1384                         cp = NULL;
1385                 if (cp) *cp = '\0'; /* delete :PORT */
1386                 setenv1("REMOTE_ADDR", p);
1387                 if (cp) {
1388                         *cp = ':';
1389 #if ENABLE_FEATURE_HTTPD_SET_REMOTE_PORT_TO_ENV
1390                         setenv1("REMOTE_PORT", cp + 1);
1391 #endif
1392                 }
1393         }
1394         setenv1("HTTP_USER_AGENT", user_agent);
1395         if (http_accept)
1396                 setenv1("HTTP_ACCEPT", http_accept);
1397         if (http_accept_language)
1398                 setenv1("HTTP_ACCEPT_LANGUAGE", http_accept_language);
1399         if (post_len)
1400                 putenv(xasprintf("CONTENT_LENGTH=%d", post_len));
1401         if (cookie)
1402                 setenv1("HTTP_COOKIE", cookie);
1403         if (content_type)
1404                 setenv1("CONTENT_TYPE", content_type);
1405 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
1406         if (remoteuser) {
1407                 setenv1("REMOTE_USER", remoteuser);
1408                 putenv((char*)"AUTH_TYPE=Basic");
1409         }
1410 #endif
1411         if (referer)
1412                 setenv1("HTTP_REFERER", referer);
1413         setenv1("HTTP_HOST", host); /* set to "" if NULL */
1414         /* setenv1("SERVER_NAME", safe_gethostname()); - don't do this,
1415          * just run "env SERVER_NAME=xyz httpd ..." instead */
1416
1417         xpiped_pair(fromCgi);
1418         xpiped_pair(toCgi);
1419
1420         pid = vfork();
1421         if (pid < 0) {
1422                 /* TODO: log perror? */
1423                 log_and_exit();
1424         }
1425
1426         if (pid == 0) {
1427                 /* Child process */
1428                 char *argv[3];
1429
1430                 xfunc_error_retval = 242;
1431
1432                 /* NB: close _first_, then move fds! */
1433                 close(toCgi.wr);
1434                 close(fromCgi.rd);
1435                 xmove_fd(toCgi.rd, 0);  /* replace stdin with the pipe */
1436                 xmove_fd(fromCgi.wr, 1);  /* replace stdout with the pipe */
1437                 /* User seeing stderr output can be a security problem.
1438                  * If CGI really wants that, it can always do dup itself. */
1439                 /* dup2(1, 2); */
1440
1441                 /* Chdiring to script's dir */
1442                 script = last_slash;
1443                 if (script != url) { /* paranoia */
1444                         *script = '\0';
1445                         if (chdir(url + 1) != 0) {
1446                                 bb_perror_msg("can't change directory to '%s'", url + 1);
1447                                 goto error_execing_cgi;
1448                         }
1449                         // not needed: *script = '/';
1450                 }
1451                 script++;
1452
1453                 /* set argv[0] to name without path */
1454                 argv[0] = script;
1455                 argv[1] = NULL;
1456
1457 #if ENABLE_FEATURE_HTTPD_CONFIG_WITH_SCRIPT_INTERPR
1458                 {
1459                         char *suffix = strrchr(script, '.');
1460
1461                         if (suffix) {
1462                                 Htaccess *cur;
1463                                 for (cur = script_i; cur; cur = cur->next) {
1464                                         if (strcmp(cur->before_colon + 1, suffix) == 0) {
1465                                                 /* found interpreter name */
1466                                                 argv[0] = cur->after_colon;
1467                                                 argv[1] = script;
1468                                                 argv[2] = NULL;
1469                                                 break;
1470                                         }
1471                                 }
1472                         }
1473                 }
1474 #endif
1475                 /* restore default signal dispositions for CGI process */
1476                 bb_signals(0
1477                         | (1 << SIGCHLD)
1478                         | (1 << SIGPIPE)
1479                         | (1 << SIGHUP)
1480                         , SIG_DFL);
1481
1482                 /* _NOT_ execvp. We do not search PATH. argv[0] is a filename
1483                  * without any dir components and will only match a file
1484                  * in the current directory */
1485                 execv(argv[0], argv);
1486                 if (verbose)
1487                         bb_perror_msg("can't execute '%s'", argv[0]);
1488  error_execing_cgi:
1489                 /* send to stdout
1490                  * (we are CGI here, our stdout is pumped to the net) */
1491                 send_headers_and_exit(HTTP_NOT_FOUND);
1492         } /* end child */
1493
1494         /* Parent process */
1495
1496         /* Restore variables possibly changed by child */
1497         xfunc_error_retval = 0;
1498
1499         /* Pump data */
1500         close(fromCgi.wr);
1501         close(toCgi.rd);
1502         cgi_io_loop_and_exit(fromCgi.rd, toCgi.wr, post_len);
1503 }
1504
1505 #endif          /* FEATURE_HTTPD_CGI */
1506
1507 /*
1508  * Send a file response to a HTTP request, and exit
1509  *
1510  * Parameters:
1511  * const char *url  The requested URL (with leading /).
1512  * what             What to send (headers/body/both).
1513  */
1514 static NOINLINE void send_file_and_exit(const char *url, int what)
1515 {
1516         char *suffix;
1517         int fd;
1518         ssize_t count;
1519
1520         if (content_gzip) {
1521                 /* does <url>.gz exist? Then use it instead */
1522                 char *gzurl = xasprintf("%s.gz", url);
1523                 fd = open(gzurl, O_RDONLY);
1524                 free(gzurl);
1525                 if (fd != -1) {
1526                         struct stat sb;
1527                         fstat(fd, &sb);
1528                         file_size = sb.st_size;
1529                         last_mod = sb.st_mtime;
1530                 } else {
1531                         IF_FEATURE_HTTPD_GZIP(content_gzip = 0;)
1532                         fd = open(url, O_RDONLY);
1533                 }
1534         } else {
1535                 fd = open(url, O_RDONLY);
1536         }
1537         if (fd < 0) {
1538                 if (DEBUG)
1539                         bb_perror_msg("can't open '%s'", url);
1540                 /* Error pages are sent by using send_file_and_exit(SEND_BODY).
1541                  * IOW: it is unsafe to call send_headers_and_exit
1542                  * if what is SEND_BODY! Can recurse! */
1543                 if (what != SEND_BODY)
1544                         send_headers_and_exit(HTTP_NOT_FOUND);
1545                 log_and_exit();
1546         }
1547         /* If you want to know about EPIPE below
1548          * (happens if you abort downloads from local httpd): */
1549         signal(SIGPIPE, SIG_IGN);
1550
1551         /* If not found, default is "application/octet-stream" */
1552         found_mime_type = "application/octet-stream";
1553         suffix = strrchr(url, '.');
1554         if (suffix) {
1555                 static const char suffixTable[] ALIGN1 =
1556                         /* Shorter suffix must be first:
1557                          * ".html.htm" will fail for ".htm"
1558                          */
1559                         ".txt.h.c.cc.cpp\0" "text/plain\0"
1560                         /* .htm line must be after .h line */
1561                         ".htm.html\0" "text/html\0"
1562                         ".jpg.jpeg\0" "image/jpeg\0"
1563                         ".gif\0"      "image/gif\0"
1564                         ".png\0"      "image/png\0"
1565                         /* .css line must be after .c line */
1566                         ".css\0"      "text/css\0"
1567                         ".wav\0"      "audio/wav\0"
1568                         ".avi\0"      "video/x-msvideo\0"
1569                         ".qt.mov\0"   "video/quicktime\0"
1570                         ".mpe.mpeg\0" "video/mpeg\0"
1571                         ".mid.midi\0" "audio/midi\0"
1572                         ".mp3\0"      "audio/mpeg\0"
1573 #if 0  /* unpopular */
1574                         ".au\0"       "audio/basic\0"
1575                         ".pac\0"      "application/x-ns-proxy-autoconfig\0"
1576                         ".vrml.wrl\0" "model/vrml\0"
1577 #endif
1578                         /* compiler adds another "\0" here */
1579                 ;
1580                 Htaccess *cur;
1581
1582                 /* Examine built-in table */
1583                 const char *table = suffixTable;
1584                 const char *table_next;
1585                 for (; *table; table = table_next) {
1586                         const char *try_suffix;
1587                         const char *mime_type;
1588                         mime_type  = table + strlen(table) + 1;
1589                         table_next = mime_type + strlen(mime_type) + 1;
1590                         try_suffix = strstr(table, suffix);
1591                         if (!try_suffix)
1592                                 continue;
1593                         try_suffix += strlen(suffix);
1594                         if (*try_suffix == '\0' || *try_suffix == '.') {
1595                                 found_mime_type = mime_type;
1596                                 break;
1597                         }
1598                         /* Example: strstr(table, ".av") != NULL, but it
1599                          * does not match ".avi" after all and we end up here.
1600                          * The table is arranged so that in this case we know
1601                          * that it can't match anything in the following lines,
1602                          * and we stop the search: */
1603                         break;
1604                 }
1605                 /* ...then user's table */
1606                 for (cur = mime_a; cur; cur = cur->next) {
1607                         if (strcmp(cur->before_colon, suffix) == 0) {
1608                                 found_mime_type = cur->after_colon;
1609                                 break;
1610                         }
1611                 }
1612         }
1613
1614         if (DEBUG)
1615                 bb_error_msg("sending file '%s' content-type: %s",
1616                         url, found_mime_type);
1617
1618 #if ENABLE_FEATURE_HTTPD_RANGES
1619         if (what == SEND_BODY /* err pages and ranges don't mix */
1620          || content_gzip /* we are sending compressed page: can't do ranges */  ///why?
1621         ) {
1622                 range_start = -1;
1623         }
1624         range_len = MAXINT(off_t);
1625         if (range_start >= 0) {
1626                 if (!range_end || range_end > file_size - 1) {
1627                         range_end = file_size - 1;
1628                 }
1629                 if (range_end < range_start
1630                  || lseek(fd, range_start, SEEK_SET) != range_start
1631                 ) {
1632                         lseek(fd, 0, SEEK_SET);
1633                         range_start = -1;
1634                 } else {
1635                         range_len = range_end - range_start + 1;
1636                         send_headers(HTTP_PARTIAL_CONTENT);
1637                         what = SEND_BODY;
1638                 }
1639         }
1640 #endif
1641         if (what & SEND_HEADERS)
1642                 send_headers(HTTP_OK);
1643 #if ENABLE_FEATURE_USE_SENDFILE
1644         {
1645                 off_t offset = range_start;
1646                 while (1) {
1647                         /* sz is rounded down to 64k */
1648                         ssize_t sz = MAXINT(ssize_t) - 0xffff;
1649                         IF_FEATURE_HTTPD_RANGES(if (sz > range_len) sz = range_len;)
1650                         count = sendfile(STDOUT_FILENO, fd, &offset, sz);
1651                         if (count < 0) {
1652                                 if (offset == range_start)
1653                                         break; /* fall back to read/write loop */
1654                                 goto fin;
1655                         }
1656                         IF_FEATURE_HTTPD_RANGES(range_len -= count;)
1657                         if (count == 0 || range_len == 0)
1658                                 log_and_exit();
1659                 }
1660         }
1661 #endif
1662         while ((count = safe_read(fd, iobuf, IOBUF_SIZE)) > 0) {
1663                 ssize_t n;
1664                 IF_FEATURE_HTTPD_RANGES(if (count > range_len) count = range_len;)
1665                 n = full_write(STDOUT_FILENO, iobuf, count);
1666                 if (count != n)
1667                         break;
1668                 IF_FEATURE_HTTPD_RANGES(range_len -= count;)
1669                 if (range_len == 0)
1670                         break;
1671         }
1672         if (count < 0) {
1673  IF_FEATURE_USE_SENDFILE(fin:)
1674                 if (verbose > 1)
1675                         bb_perror_msg("error");
1676         }
1677         log_and_exit();
1678 }
1679
1680 static int checkPermIP(void)
1681 {
1682         Htaccess_IP *cur;
1683
1684         for (cur = ip_a_d; cur; cur = cur->next) {
1685 #if DEBUG
1686                 fprintf(stderr,
1687                         "checkPermIP: '%s' ? '%u.%u.%u.%u/%u.%u.%u.%u'\n",
1688                         rmt_ip_str,
1689                         (unsigned char)(cur->ip >> 24),
1690                         (unsigned char)(cur->ip >> 16),
1691                         (unsigned char)(cur->ip >> 8),
1692                         (unsigned char)(cur->ip),
1693                         (unsigned char)(cur->mask >> 24),
1694                         (unsigned char)(cur->mask >> 16),
1695                         (unsigned char)(cur->mask >> 8),
1696                         (unsigned char)(cur->mask)
1697                 );
1698 #endif
1699                 if ((rmt_ip & cur->mask) == cur->ip)
1700                         return (cur->allow_deny == 'A'); /* A -> 1 */
1701         }
1702
1703         return !flg_deny_all; /* depends on whether we saw "D:*" */
1704 }
1705
1706 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
1707
1708 # if ENABLE_PAM
1709 struct pam_userinfo {
1710         const char *name;
1711         const char *pw;
1712 };
1713
1714 static int pam_talker(int num_msg,
1715                 const struct pam_message **msg,
1716                 struct pam_response **resp,
1717                 void *appdata_ptr)
1718 {
1719         int i;
1720         struct pam_userinfo *userinfo = (struct pam_userinfo *) appdata_ptr;
1721         struct pam_response *response;
1722
1723         if (!resp || !msg || !userinfo)
1724                 return PAM_CONV_ERR;
1725
1726         /* allocate memory to store response */
1727         response = xzalloc(num_msg * sizeof(*response));
1728
1729         /* copy values */
1730         for (i = 0; i < num_msg; i++) {
1731                 const char *s;
1732
1733                 switch (msg[i]->msg_style) {
1734                 case PAM_PROMPT_ECHO_ON:
1735                         s = userinfo->name;
1736                         break;
1737                 case PAM_PROMPT_ECHO_OFF:
1738                         s = userinfo->pw;
1739                         break;
1740                 case PAM_ERROR_MSG:
1741                 case PAM_TEXT_INFO:
1742                         s = "";
1743                         break;
1744                 default:
1745                         free(response);
1746                         return PAM_CONV_ERR;
1747                 }
1748                 response[i].resp = xstrdup(s);
1749                 if (PAM_SUCCESS != 0)
1750                         response[i].resp_retcode = PAM_SUCCESS;
1751         }
1752         *resp = response;
1753         return PAM_SUCCESS;
1754 }
1755 # endif
1756
1757 /*
1758  * Config file entries are of the form "/<path>:<user>:<passwd>".
1759  * If config file has no prefix match for path, access is allowed.
1760  *
1761  * path                 The file path
1762  * user_and_passwd      "user:passwd" to validate
1763  *
1764  * Returns 1 if user_and_passwd is OK.
1765  */
1766 static int check_user_passwd(const char *path, char *user_and_passwd)
1767 {
1768         Htaccess *cur;
1769         const char *prev = NULL;
1770
1771         for (cur = g_auth; cur; cur = cur->next) {
1772                 const char *dir_prefix;
1773                 size_t len;
1774                 int r;
1775
1776                 dir_prefix = cur->before_colon;
1777
1778                 /* WHY? */
1779                 /* If already saw a match, don't accept other different matches */
1780                 if (prev && strcmp(prev, dir_prefix) != 0)
1781                         continue;
1782
1783                 if (DEBUG)
1784                         fprintf(stderr, "checkPerm: '%s' ? '%s'\n", dir_prefix, user_and_passwd);
1785
1786                 /* If it's not a prefix match, continue searching */
1787                 len = strlen(dir_prefix);
1788                 if (len != 1 /* dir_prefix "/" matches all, don't need to check */
1789                  && (strncmp(dir_prefix, path, len) != 0
1790                     || (path[len] != '/' && path[len] != '\0')
1791                     )
1792                 ) {
1793                         continue;
1794                 }
1795
1796                 /* Path match found */
1797                 prev = dir_prefix;
1798
1799                 if (ENABLE_FEATURE_HTTPD_AUTH_MD5) {
1800                         char *colon_after_user;
1801                         const char *passwd;
1802 # if ENABLE_FEATURE_SHADOWPASSWDS && !ENABLE_PAM
1803                         char sp_buf[256];
1804 # endif
1805
1806                         colon_after_user = strchr(user_and_passwd, ':');
1807                         if (!colon_after_user)
1808                                 goto bad_input;
1809
1810                         /* compare "user:" */
1811                         if (cur->after_colon[0] != '*'
1812                          && strncmp(cur->after_colon, user_and_passwd,
1813                                         colon_after_user - user_and_passwd + 1) != 0
1814                         ) {
1815                                 continue;
1816                         }
1817                         /* this cfg entry is '*' or matches username from peer */
1818
1819                         passwd = strchr(cur->after_colon, ':');
1820                         if (!passwd)
1821                                 goto bad_input;
1822                         passwd++;
1823                         if (passwd[0] == '*') {
1824 # if ENABLE_PAM
1825                                 struct pam_userinfo userinfo;
1826                                 struct pam_conv conv_info = { &pam_talker, (void *) &userinfo };
1827                                 pam_handle_t *pamh;
1828
1829                                 *colon_after_user = '\0';
1830                                 userinfo.name = user_and_passwd;
1831                                 userinfo.pw = colon_after_user + 1;
1832                                 r = pam_start("httpd", user_and_passwd, &conv_info, &pamh) != PAM_SUCCESS;
1833                                 if (r == 0) {
1834                                         r = pam_authenticate(pamh, PAM_DISALLOW_NULL_AUTHTOK) != PAM_SUCCESS
1835                                          || pam_acct_mgmt(pamh, PAM_DISALLOW_NULL_AUTHTOK)    != PAM_SUCCESS
1836                                         ;
1837                                         pam_end(pamh, PAM_SUCCESS);
1838                                 }
1839                                 *colon_after_user = ':';
1840                                 goto end_check_passwd;
1841 # else
1842 #  if ENABLE_FEATURE_SHADOWPASSWDS
1843                                 /* Using _r function to avoid pulling in static buffers */
1844                                 struct spwd spw;
1845 #  endif
1846                                 struct passwd *pw;
1847
1848                                 *colon_after_user = '\0';
1849                                 pw = getpwnam(user_and_passwd);
1850                                 *colon_after_user = ':';
1851                                 if (!pw || !pw->pw_passwd)
1852                                         continue;
1853                                 passwd = pw->pw_passwd;
1854 #  if ENABLE_FEATURE_SHADOWPASSWDS
1855                                 if ((passwd[0] == 'x' || passwd[0] == '*') && !passwd[1]) {
1856                                         /* getspnam_r may return 0 yet set result to NULL.
1857                                          * At least glibc 2.4 does this. Be extra paranoid here. */
1858                                         struct spwd *result = NULL;
1859                                         r = getspnam_r(pw->pw_name, &spw, sp_buf, sizeof(sp_buf), &result);
1860                                         if (r == 0 && result)
1861                                                 passwd = result->sp_pwdp;
1862                                 }
1863 #  endif
1864                                 /* In this case, passwd is ALWAYS encrypted:
1865                                  * it came from /etc/passwd or /etc/shadow!
1866                                  */
1867                                 goto check_encrypted;
1868 # endif /* ENABLE_PAM */
1869                         }
1870                         /* Else: passwd is from httpd.conf, it is either plaintext or encrypted */
1871
1872                         if (passwd[0] == '$' && isdigit(passwd[1])) {
1873                                 char *encrypted;
1874 # if !ENABLE_PAM
1875  check_encrypted:
1876 # endif
1877                                 /* encrypt pwd from peer and check match with local one */
1878                                 encrypted = pw_encrypt(
1879                                         /* pwd (from peer): */  colon_after_user + 1,
1880                                         /* salt: */ passwd,
1881                                         /* cleanup: */ 0
1882                                 );
1883                                 r = strcmp(encrypted, passwd);
1884                                 free(encrypted);
1885                         } else {
1886                                 /* local passwd is from httpd.conf and it's plaintext */
1887                                 r = strcmp(colon_after_user + 1, passwd);
1888                         }
1889                         goto end_check_passwd;
1890                 }
1891  bad_input:
1892                 /* Comparing plaintext "user:pass" in one go */
1893                 r = strcmp(cur->after_colon, user_and_passwd);
1894  end_check_passwd:
1895                 if (r == 0) {
1896                         remoteuser = xstrndup(user_and_passwd,
1897                                 strchrnul(user_and_passwd, ':') - user_and_passwd
1898                         );
1899                         return 1; /* Ok */
1900                 }
1901         } /* for */
1902
1903         /* 0(bad) if prev is set: matches were found but passwd was wrong */
1904         return (prev == NULL);
1905 }
1906 #endif  /* FEATURE_HTTPD_BASIC_AUTH */
1907
1908 #if ENABLE_FEATURE_HTTPD_PROXY
1909 static Htaccess_Proxy *find_proxy_entry(const char *url)
1910 {
1911         Htaccess_Proxy *p;
1912         for (p = proxy; p; p = p->next) {
1913                 if (is_prefixed_with(url, p->url_from))
1914                         return p;
1915         }
1916         return NULL;
1917 }
1918 #endif
1919
1920 /*
1921  * Handle timeouts
1922  */
1923 static void send_REQUEST_TIMEOUT_and_exit(int sig) NORETURN;
1924 static void send_REQUEST_TIMEOUT_and_exit(int sig UNUSED_PARAM)
1925 {
1926         send_headers_and_exit(HTTP_REQUEST_TIMEOUT);
1927 }
1928
1929 /*
1930  * Handle an incoming http request and exit.
1931  */
1932 static void handle_incoming_and_exit(const len_and_sockaddr *fromAddr) NORETURN;
1933 static void handle_incoming_and_exit(const len_and_sockaddr *fromAddr)
1934 {
1935         static const char request_GET[] ALIGN1 = "GET";
1936         struct stat sb;
1937         char *urlcopy;
1938         char *urlp;
1939         char *tptr;
1940 #if ENABLE_FEATURE_HTTPD_CGI
1941         static const char request_HEAD[] ALIGN1 = "HEAD";
1942         const char *prequest;
1943         char *cookie = NULL;
1944         char *content_type = NULL;
1945         unsigned long length = 0;
1946 #elif ENABLE_FEATURE_HTTPD_PROXY
1947 #define prequest request_GET
1948         unsigned long length = 0;
1949 #endif
1950 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
1951         smallint authorized = -1;
1952 #endif
1953         smallint ip_allowed;
1954         char http_major_version;
1955 #if ENABLE_FEATURE_HTTPD_PROXY
1956         char http_minor_version;
1957         char *header_buf = header_buf; /* for gcc */
1958         char *header_ptr = header_ptr;
1959         Htaccess_Proxy *proxy_entry;
1960 #endif
1961
1962         /* Allocation of iobuf is postponed until now
1963          * (IOW, server process doesn't need to waste 8k) */
1964         iobuf = xmalloc(IOBUF_SIZE);
1965
1966         rmt_ip = 0;
1967         if (fromAddr->u.sa.sa_family == AF_INET) {
1968                 rmt_ip = ntohl(fromAddr->u.sin.sin_addr.s_addr);
1969         }
1970 #if ENABLE_FEATURE_IPV6
1971         if (fromAddr->u.sa.sa_family == AF_INET6
1972          && fromAddr->u.sin6.sin6_addr.s6_addr32[0] == 0
1973          && fromAddr->u.sin6.sin6_addr.s6_addr32[1] == 0
1974          && ntohl(fromAddr->u.sin6.sin6_addr.s6_addr32[2]) == 0xffff)
1975                 rmt_ip = ntohl(fromAddr->u.sin6.sin6_addr.s6_addr32[3]);
1976 #endif
1977         if (ENABLE_FEATURE_HTTPD_CGI || DEBUG || verbose) {
1978                 /* NB: can be NULL (user runs httpd -i by hand?) */
1979                 rmt_ip_str = xmalloc_sockaddr2dotted(&fromAddr->u.sa);
1980         }
1981         if (verbose) {
1982                 /* this trick makes -v logging much simpler */
1983                 if (rmt_ip_str)
1984                         applet_name = rmt_ip_str;
1985                 if (verbose > 2)
1986                         bb_error_msg("connected");
1987         }
1988
1989         /* Install timeout handler. get_line() needs it. */
1990         signal(SIGALRM, send_REQUEST_TIMEOUT_and_exit);
1991
1992         if (!get_line()) /* EOF or error or empty line */
1993                 send_headers_and_exit(HTTP_BAD_REQUEST);
1994
1995         /* Determine type of request (GET/POST) */
1996         // rfc2616: method and URI is separated by exactly one space
1997         //urlp = strpbrk(iobuf, " \t"); - no, tab isn't allowed
1998         urlp = strchr(iobuf, ' ');
1999         if (urlp == NULL)
2000                 send_headers_and_exit(HTTP_BAD_REQUEST);
2001         *urlp++ = '\0';
2002 #if ENABLE_FEATURE_HTTPD_CGI
2003         prequest = request_GET;
2004         if (strcasecmp(iobuf, prequest) != 0) {
2005                 prequest = request_HEAD;
2006                 if (strcasecmp(iobuf, prequest) != 0) {
2007                         prequest = "POST";
2008                         if (strcasecmp(iobuf, prequest) != 0)
2009                                 send_headers_and_exit(HTTP_NOT_IMPLEMENTED);
2010                 }
2011         }
2012 #else
2013         if (strcasecmp(iobuf, request_GET) != 0)
2014                 send_headers_and_exit(HTTP_NOT_IMPLEMENTED);
2015 #endif
2016         // rfc2616: method and URI is separated by exactly one space
2017         //urlp = skip_whitespace(urlp); - should not be necessary
2018         if (urlp[0] != '/')
2019                 send_headers_and_exit(HTTP_BAD_REQUEST);
2020
2021         /* Find end of URL and parse HTTP version, if any */
2022         http_major_version = '0';
2023         IF_FEATURE_HTTPD_PROXY(http_minor_version = '0';)
2024         tptr = strchrnul(urlp, ' ');
2025         /* Is it " HTTP/"? */
2026         if (tptr[0] && strncmp(tptr + 1, HTTP_200, 5) == 0) {
2027                 http_major_version = tptr[6];
2028                 IF_FEATURE_HTTPD_PROXY(http_minor_version = tptr[8];)
2029         }
2030         *tptr = '\0';
2031
2032         /* Copy URL from after "GET "/"POST " to stack-allocated char[] */
2033         urlcopy = alloca((tptr - urlp) + 2 + strlen(index_page));
2034         /*if (urlcopy == NULL)
2035          *      send_headers_and_exit(HTTP_INTERNAL_SERVER_ERROR);*/
2036         strcpy(urlcopy, urlp);
2037         /* NB: urlcopy ptr is never changed after this */
2038
2039         /* Extract url args if present */
2040         /* g_query = NULL; - already is */
2041         tptr = strchr(urlcopy, '?');
2042         if (tptr) {
2043                 *tptr++ = '\0';
2044                 g_query = tptr;
2045         }
2046
2047         /* Decode URL escape sequences */
2048         tptr = percent_decode_in_place(urlcopy, /*strict:*/ 1);
2049         if (tptr == NULL)
2050                 send_headers_and_exit(HTTP_BAD_REQUEST);
2051         if (tptr == urlcopy + 1) {
2052                 /* '/' or NUL is encoded */
2053                 send_headers_and_exit(HTTP_NOT_FOUND);
2054         }
2055
2056         /* Canonicalize path */
2057         /* Algorithm stolen from libbb bb_simplify_path(),
2058          * but don't strdup, retain trailing slash, protect root */
2059         urlp = tptr = urlcopy;
2060         for (;;) {
2061                 if (*urlp == '/') {
2062                         /* skip duplicate (or initial) slash */
2063                         if (*tptr == '/') {
2064                                 goto next_char;
2065                         }
2066                         if (*tptr == '.') {
2067                                 if (tptr[1] == '.' && (tptr[2] == '/' || tptr[2] == '\0')) {
2068                                         /* "..": be careful */
2069                                         /* protect root */
2070                                         if (urlp == urlcopy)
2071                                                 send_headers_and_exit(HTTP_BAD_REQUEST);
2072                                         /* omit previous dir */
2073                                         while (*--urlp != '/')
2074                                                 continue;
2075                                         /* skip to "./" or ".<NUL>" */
2076                                         tptr++;
2077                                 }
2078                                 if (tptr[1] == '/' || tptr[1] == '\0') {
2079                                         /* skip extra "/./" */
2080                                         goto next_char;
2081                                 }
2082                         }
2083                 }
2084                 *++urlp = *tptr;
2085                 if (*urlp == '\0')
2086                         break;
2087  next_char:
2088                 tptr++;
2089         }
2090
2091         /* If URL is a directory, add '/' */
2092         if (urlp[-1] != '/') {
2093                 if (is_directory(urlcopy + 1, /*followlinks:*/ 1)) {
2094                         found_moved_temporarily = urlcopy;
2095                 }
2096         }
2097
2098         /* Log it */
2099         if (verbose > 1)
2100                 bb_error_msg("url:%s", urlcopy);
2101
2102         tptr = urlcopy;
2103         ip_allowed = checkPermIP();
2104         while (ip_allowed && (tptr = strchr(tptr + 1, '/')) != NULL) {
2105                 /* have path1/path2 */
2106                 *tptr = '\0';
2107                 if (is_directory(urlcopy + 1, /*followlinks:*/ 1)) {
2108                         /* may have subdir config */
2109                         parse_conf(urlcopy + 1, SUBDIR_PARSE);
2110                         ip_allowed = checkPermIP();
2111                 }
2112                 *tptr = '/';
2113         }
2114
2115 #if ENABLE_FEATURE_HTTPD_PROXY
2116         proxy_entry = find_proxy_entry(urlcopy);
2117         if (proxy_entry)
2118                 header_buf = header_ptr = xmalloc(IOBUF_SIZE);
2119 #endif
2120
2121         if (http_major_version >= '0') {
2122                 /* Request was with "... HTTP/nXXX", and n >= 0 */
2123
2124                 /* Read until blank line */
2125                 while (1) {
2126                         if (!get_line())
2127                                 break; /* EOF or error or empty line */
2128                         if (DEBUG)
2129                                 bb_error_msg("header: '%s'", iobuf);
2130
2131 #if ENABLE_FEATURE_HTTPD_PROXY
2132                         /* We need 2 more bytes for yet another "\r\n" -
2133                          * see near fdprintf(proxy_fd...) further below */
2134                         if (proxy_entry && (header_ptr - header_buf) < IOBUF_SIZE - 2) {
2135                                 int len = strlen(iobuf);
2136                                 if (len > IOBUF_SIZE - (header_ptr - header_buf) - 4)
2137                                         len = IOBUF_SIZE - (header_ptr - header_buf) - 4;
2138                                 memcpy(header_ptr, iobuf, len);
2139                                 header_ptr += len;
2140                                 header_ptr[0] = '\r';
2141                                 header_ptr[1] = '\n';
2142                                 header_ptr += 2;
2143                         }
2144 #endif
2145
2146 #if ENABLE_FEATURE_HTTPD_CGI || ENABLE_FEATURE_HTTPD_PROXY
2147                         /* Try and do our best to parse more lines */
2148                         if ((STRNCASECMP(iobuf, "Content-length:") == 0)) {
2149                                 /* extra read only for POST */
2150                                 if (prequest != request_GET
2151 # if ENABLE_FEATURE_HTTPD_CGI
2152                                  && prequest != request_HEAD
2153 # endif
2154                                 ) {
2155                                         tptr = skip_whitespace(iobuf + sizeof("Content-length:") - 1);
2156                                         if (!tptr[0])
2157                                                 send_headers_and_exit(HTTP_BAD_REQUEST);
2158                                         /* not using strtoul: it ignores leading minus! */
2159                                         length = bb_strtou(tptr, NULL, 10);
2160                                         /* length is "ulong", but we need to pass it to int later */
2161                                         if (errno || length > INT_MAX)
2162                                                 send_headers_and_exit(HTTP_BAD_REQUEST);
2163                                 }
2164                         }
2165 #endif
2166 #if ENABLE_FEATURE_HTTPD_CGI
2167                         else if (STRNCASECMP(iobuf, "Cookie:") == 0) {
2168                                 cookie = xstrdup(skip_whitespace(iobuf + sizeof("Cookie:")-1));
2169                         } else if (STRNCASECMP(iobuf, "Content-Type:") == 0) {
2170                                 content_type = xstrdup(skip_whitespace(iobuf + sizeof("Content-Type:")-1));
2171                         } else if (STRNCASECMP(iobuf, "Referer:") == 0) {
2172                                 referer = xstrdup(skip_whitespace(iobuf + sizeof("Referer:")-1));
2173                         } else if (STRNCASECMP(iobuf, "User-Agent:") == 0) {
2174                                 user_agent = xstrdup(skip_whitespace(iobuf + sizeof("User-Agent:")-1));
2175                         } else if (STRNCASECMP(iobuf, "Host:") == 0) {
2176                                 host = xstrdup(skip_whitespace(iobuf + sizeof("Host:")-1));
2177                         } else if (STRNCASECMP(iobuf, "Accept:") == 0) {
2178                                 http_accept = xstrdup(skip_whitespace(iobuf + sizeof("Accept:")-1));
2179                         } else if (STRNCASECMP(iobuf, "Accept-Language:") == 0) {
2180                                 http_accept_language = xstrdup(skip_whitespace(iobuf + sizeof("Accept-Language:")-1));
2181                         }
2182 #endif
2183 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
2184                         if (STRNCASECMP(iobuf, "Authorization:") == 0) {
2185                                 /* We only allow Basic credentials.
2186                                  * It shows up as "Authorization: Basic <user>:<passwd>" where
2187                                  * "<user>:<passwd>" is base64 encoded.
2188                                  */
2189                                 tptr = skip_whitespace(iobuf + sizeof("Authorization:")-1);
2190                                 if (STRNCASECMP(tptr, "Basic") != 0)
2191                                         continue;
2192                                 tptr += sizeof("Basic")-1;
2193                                 /* decodeBase64() skips whitespace itself */
2194                                 decodeBase64(tptr);
2195                                 authorized = check_user_passwd(urlcopy, tptr);
2196                         }
2197 #endif
2198 #if ENABLE_FEATURE_HTTPD_RANGES
2199                         if (STRNCASECMP(iobuf, "Range:") == 0) {
2200                                 /* We know only bytes=NNN-[MMM] */
2201                                 char *s = skip_whitespace(iobuf + sizeof("Range:")-1);
2202                                 if (is_prefixed_with(s, "bytes=") == 0) {
2203                                         s += sizeof("bytes=")-1;
2204                                         range_start = BB_STRTOOFF(s, &s, 10);
2205                                         if (s[0] != '-' || range_start < 0) {
2206                                                 range_start = -1;
2207                                         } else if (s[1]) {
2208                                                 range_end = BB_STRTOOFF(s+1, NULL, 10);
2209                                                 if (errno || range_end < range_start)
2210                                                         range_start = -1;
2211                                         }
2212                                 }
2213                         }
2214 #endif
2215 #if ENABLE_FEATURE_HTTPD_GZIP
2216                         if (STRNCASECMP(iobuf, "Accept-Encoding:") == 0) {
2217                                 /* Note: we do not support "gzip;q=0"
2218                                  * method of _disabling_ gzip
2219                                  * delivery. No one uses that, though */
2220                                 const char *s = strstr(iobuf, "gzip");
2221                                 if (s) {
2222                                         // want more thorough checks?
2223                                         //if (s[-1] == ' '
2224                                         // || s[-1] == ','
2225                                         // || s[-1] == ':'
2226                                         //) {
2227                                                 content_gzip = 1;
2228                                         //}
2229                                 }
2230                         }
2231 #endif
2232                 } /* while extra header reading */
2233         }
2234
2235         /* We are done reading headers, disable peer timeout */
2236         alarm(0);
2237
2238         if (strcmp(bb_basename(urlcopy), HTTPD_CONF) == 0 || !ip_allowed) {
2239                 /* protect listing [/path]/httpd.conf or IP deny */
2240                 send_headers_and_exit(HTTP_FORBIDDEN);
2241         }
2242
2243 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
2244         /* Case: no "Authorization:" was seen, but page might require passwd.
2245          * Check that with dummy user:pass */
2246         if (authorized < 0)
2247                 authorized = check_user_passwd(urlcopy, (char *) "");
2248         if (!authorized)
2249                 send_headers_and_exit(HTTP_UNAUTHORIZED);
2250 #endif
2251
2252         if (found_moved_temporarily) {
2253                 send_headers_and_exit(HTTP_MOVED_TEMPORARILY);
2254         }
2255
2256 #if ENABLE_FEATURE_HTTPD_PROXY
2257         if (proxy_entry != NULL) {
2258                 int proxy_fd;
2259                 len_and_sockaddr *lsa;
2260
2261                 proxy_fd = socket(AF_INET, SOCK_STREAM, 0);
2262                 if (proxy_fd < 0)
2263                         send_headers_and_exit(HTTP_INTERNAL_SERVER_ERROR);
2264                 lsa = host2sockaddr(proxy_entry->host_port, 80);
2265                 if (lsa == NULL)
2266                         send_headers_and_exit(HTTP_INTERNAL_SERVER_ERROR);
2267                 if (connect(proxy_fd, &lsa->u.sa, lsa->len) < 0)
2268                         send_headers_and_exit(HTTP_INTERNAL_SERVER_ERROR);
2269                 fdprintf(proxy_fd, "%s %s%s%s%s HTTP/%c.%c\r\n",
2270                                 prequest, /* GET or POST */
2271                                 proxy_entry->url_to, /* url part 1 */
2272                                 urlcopy + strlen(proxy_entry->url_from), /* url part 2 */
2273                                 (g_query ? "?" : ""), /* "?" (maybe) */
2274                                 (g_query ? g_query : ""), /* query string (maybe) */
2275                                 http_major_version, http_minor_version);
2276                 header_ptr[0] = '\r';
2277                 header_ptr[1] = '\n';
2278                 header_ptr += 2;
2279                 write(proxy_fd, header_buf, header_ptr - header_buf);
2280                 free(header_buf); /* on the order of 8k, free it */
2281                 cgi_io_loop_and_exit(proxy_fd, proxy_fd, length);
2282         }
2283 #endif
2284
2285         tptr = urlcopy + 1;      /* skip first '/' */
2286
2287 #if ENABLE_FEATURE_HTTPD_CGI
2288         if (is_prefixed_with(tptr, "cgi-bin/")) {
2289                 if (tptr[8] == '\0') {
2290                         /* protect listing "cgi-bin/" */
2291                         send_headers_and_exit(HTTP_FORBIDDEN);
2292                 }
2293                 send_cgi_and_exit(urlcopy, urlcopy, prequest, length, cookie, content_type);
2294         }
2295 #endif
2296
2297         if (urlp[-1] == '/') {
2298                 /* When index_page string is appended to <dir>/ URL, it overwrites
2299                  * the query string. If we fall back to call /cgi-bin/index.cgi,
2300                  * query string would be lost and not available to the CGI.
2301                  * Work around it by making a deep copy.
2302                  */
2303                 if (ENABLE_FEATURE_HTTPD_CGI)
2304                         g_query = xstrdup(g_query); /* ok for NULL too */
2305                 strcpy(urlp, index_page);
2306         }
2307         if (stat(tptr, &sb) == 0) {
2308 #if ENABLE_FEATURE_HTTPD_CONFIG_WITH_SCRIPT_INTERPR
2309                 char *suffix = strrchr(tptr, '.');
2310                 if (suffix) {
2311                         Htaccess *cur;
2312                         for (cur = script_i; cur; cur = cur->next) {
2313                                 if (strcmp(cur->before_colon + 1, suffix) == 0) {
2314                                         send_cgi_and_exit(urlcopy, urlcopy, prequest, length, cookie, content_type);
2315                                 }
2316                         }
2317                 }
2318 #endif
2319                 file_size = sb.st_size;
2320                 last_mod = sb.st_mtime;
2321         }
2322 #if ENABLE_FEATURE_HTTPD_CGI
2323         else if (urlp[-1] == '/') {
2324                 /* It's a dir URL and there is no index.html
2325                  * Try cgi-bin/index.cgi */
2326                 if (access("/cgi-bin/index.cgi"+1, X_OK) == 0) {
2327                         urlp[0] = '\0'; /* remove index_page */
2328                         send_cgi_and_exit("/cgi-bin/index.cgi", urlcopy, prequest, length, cookie, content_type);
2329                 }
2330         }
2331         /* else fall through to send_file, it errors out if open fails: */
2332
2333         if (prequest != request_GET && prequest != request_HEAD) {
2334                 /* POST for files does not make sense */
2335                 send_headers_and_exit(HTTP_NOT_IMPLEMENTED);
2336         }
2337         send_file_and_exit(tptr,
2338                 (prequest != request_HEAD ? SEND_HEADERS_AND_BODY : SEND_HEADERS)
2339         );
2340 #else
2341         send_file_and_exit(tptr, SEND_HEADERS_AND_BODY);
2342 #endif
2343 }
2344
2345 /*
2346  * The main http server function.
2347  * Given a socket, listen for new connections and farm out
2348  * the processing as a [v]forked process.
2349  * Never returns.
2350  */
2351 #if BB_MMU
2352 static void mini_httpd(int server_socket) NORETURN;
2353 static void mini_httpd(int server_socket)
2354 {
2355         /* NB: it's best to not use xfuncs in this loop before fork().
2356          * Otherwise server may die on transient errors (temporary
2357          * out-of-memory condition, etc), which is Bad(tm).
2358          * Try to do any dangerous calls after fork.
2359          */
2360         while (1) {
2361                 int n;
2362                 len_and_sockaddr fromAddr;
2363
2364                 /* Wait for connections... */
2365                 fromAddr.len = LSA_SIZEOF_SA;
2366                 n = accept(server_socket, &fromAddr.u.sa, &fromAddr.len);
2367                 if (n < 0)
2368                         continue;
2369
2370                 /* set the KEEPALIVE option to cull dead connections */
2371                 setsockopt_keepalive(n);
2372
2373                 if (fork() == 0) {
2374                         /* child */
2375                         /* Do not reload config on HUP */
2376                         signal(SIGHUP, SIG_IGN);
2377                         close(server_socket);
2378                         xmove_fd(n, 0);
2379                         xdup2(0, 1);
2380
2381                         handle_incoming_and_exit(&fromAddr);
2382                 }
2383                 /* parent, or fork failed */
2384                 close(n);
2385         } /* while (1) */
2386         /* never reached */
2387 }
2388 #else
2389 static void mini_httpd_nommu(int server_socket, int argc, char **argv) NORETURN;
2390 static void mini_httpd_nommu(int server_socket, int argc, char **argv)
2391 {
2392         char *argv_copy[argc + 2];
2393
2394         argv_copy[0] = argv[0];
2395         argv_copy[1] = (char*)"-i";
2396         memcpy(&argv_copy[2], &argv[1], argc * sizeof(argv[0]));
2397
2398         /* NB: it's best to not use xfuncs in this loop before vfork().
2399          * Otherwise server may die on transient errors (temporary
2400          * out-of-memory condition, etc), which is Bad(tm).
2401          * Try to do any dangerous calls after fork.
2402          */
2403         while (1) {
2404                 int n;
2405                 len_and_sockaddr fromAddr;
2406
2407                 /* Wait for connections... */
2408                 fromAddr.len = LSA_SIZEOF_SA;
2409                 n = accept(server_socket, &fromAddr.u.sa, &fromAddr.len);
2410                 if (n < 0)
2411                         continue;
2412
2413                 /* set the KEEPALIVE option to cull dead connections */
2414                 setsockopt_keepalive(n);
2415
2416                 if (vfork() == 0) {
2417                         /* child */
2418                         /* Do not reload config on HUP */
2419                         signal(SIGHUP, SIG_IGN);
2420                         close(server_socket);
2421                         xmove_fd(n, 0);
2422                         xdup2(0, 1);
2423
2424                         /* Run a copy of ourself in inetd mode */
2425                         re_exec(argv_copy);
2426                 }
2427                 argv_copy[0][0] &= 0x7f;
2428                 /* parent, or vfork failed */
2429                 close(n);
2430         } /* while (1) */
2431         /* never reached */
2432 }
2433 #endif
2434
2435 /*
2436  * Process a HTTP connection on stdin/out.
2437  * Never returns.
2438  */
2439 static void mini_httpd_inetd(void) NORETURN;
2440 static void mini_httpd_inetd(void)
2441 {
2442         len_and_sockaddr fromAddr;
2443
2444         memset(&fromAddr, 0, sizeof(fromAddr));
2445         fromAddr.len = LSA_SIZEOF_SA;
2446         /* NB: can fail if user runs it by hand and types in http cmds */
2447         getpeername(0, &fromAddr.u.sa, &fromAddr.len);
2448         handle_incoming_and_exit(&fromAddr);
2449 }
2450
2451 static void sighup_handler(int sig UNUSED_PARAM)
2452 {
2453         parse_conf(DEFAULT_PATH_HTTPD_CONF, SIGNALED_PARSE);
2454 }
2455
2456 enum {
2457         c_opt_config_file = 0,
2458         d_opt_decode_url,
2459         h_opt_home_httpd,
2460         IF_FEATURE_HTTPD_ENCODE_URL_STR(e_opt_encode_url,)
2461         IF_FEATURE_HTTPD_BASIC_AUTH(    r_opt_realm     ,)
2462         IF_FEATURE_HTTPD_AUTH_MD5(      m_opt_md5       ,)
2463         IF_FEATURE_HTTPD_SETUID(        u_opt_setuid    ,)
2464         p_opt_port      ,
2465         p_opt_inetd     ,
2466         p_opt_foreground,
2467         p_opt_verbose   ,
2468         OPT_CONFIG_FILE = 1 << c_opt_config_file,
2469         OPT_DECODE_URL  = 1 << d_opt_decode_url,
2470         OPT_HOME_HTTPD  = 1 << h_opt_home_httpd,
2471         OPT_ENCODE_URL  = IF_FEATURE_HTTPD_ENCODE_URL_STR((1 << e_opt_encode_url)) + 0,
2472         OPT_REALM       = IF_FEATURE_HTTPD_BASIC_AUTH(    (1 << r_opt_realm     )) + 0,
2473         OPT_MD5         = IF_FEATURE_HTTPD_AUTH_MD5(      (1 << m_opt_md5       )) + 0,
2474         OPT_SETUID      = IF_FEATURE_HTTPD_SETUID(        (1 << u_opt_setuid    )) + 0,
2475         OPT_PORT        = 1 << p_opt_port,
2476         OPT_INETD       = 1 << p_opt_inetd,
2477         OPT_FOREGROUND  = 1 << p_opt_foreground,
2478         OPT_VERBOSE     = 1 << p_opt_verbose,
2479 };
2480
2481
2482 int httpd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
2483 int httpd_main(int argc UNUSED_PARAM, char **argv)
2484 {
2485         int server_socket = server_socket; /* for gcc */
2486         unsigned opt;
2487         char *url_for_decode;
2488         IF_FEATURE_HTTPD_ENCODE_URL_STR(const char *url_for_encode;)
2489         IF_FEATURE_HTTPD_SETUID(const char *s_ugid = NULL;)
2490         IF_FEATURE_HTTPD_SETUID(struct bb_uidgid_t ugid;)
2491         IF_FEATURE_HTTPD_AUTH_MD5(const char *pass;)
2492
2493         INIT_G();
2494
2495 #if ENABLE_LOCALE_SUPPORT
2496         /* Undo busybox.c: we want to speak English in http (dates etc) */
2497         setlocale(LC_TIME, "C");
2498 #endif
2499
2500         home_httpd = xrealloc_getcwd_or_warn(NULL);
2501         /* -v counts, -i implies -f */
2502         opt_complementary = "vv:if";
2503         /* We do not "absolutize" path given by -h (home) opt.
2504          * If user gives relative path in -h,
2505          * $SCRIPT_FILENAME will not be set. */
2506         opt = getopt32(argv, "c:d:h:"
2507                         IF_FEATURE_HTTPD_ENCODE_URL_STR("e:")
2508                         IF_FEATURE_HTTPD_BASIC_AUTH("r:")
2509                         IF_FEATURE_HTTPD_AUTH_MD5("m:")
2510                         IF_FEATURE_HTTPD_SETUID("u:")
2511                         "p:ifv",
2512                         &opt_c_configFile, &url_for_decode, &home_httpd
2513                         IF_FEATURE_HTTPD_ENCODE_URL_STR(, &url_for_encode)
2514                         IF_FEATURE_HTTPD_BASIC_AUTH(, &g_realm)
2515                         IF_FEATURE_HTTPD_AUTH_MD5(, &pass)
2516                         IF_FEATURE_HTTPD_SETUID(, &s_ugid)
2517                         , &bind_addr_or_port
2518                         , &verbose
2519                 );
2520         if (opt & OPT_DECODE_URL) {
2521                 fputs(percent_decode_in_place(url_for_decode, /*strict:*/ 0), stdout);
2522                 return 0;
2523         }
2524 #if ENABLE_FEATURE_HTTPD_ENCODE_URL_STR
2525         if (opt & OPT_ENCODE_URL) {
2526                 fputs(encodeString(url_for_encode), stdout);
2527                 return 0;
2528         }
2529 #endif
2530 #if ENABLE_FEATURE_HTTPD_AUTH_MD5
2531         if (opt & OPT_MD5) {
2532                 char salt[sizeof("$1$XXXXXXXX")];
2533                 salt[0] = '$';
2534                 salt[1] = '1';
2535                 salt[2] = '$';
2536                 crypt_make_salt(salt + 3, 4);
2537                 puts(pw_encrypt(pass, salt, /*cleanup:*/ 0));
2538                 return 0;
2539         }
2540 #endif
2541 #if ENABLE_FEATURE_HTTPD_SETUID
2542         if (opt & OPT_SETUID) {
2543                 xget_uidgid(&ugid, s_ugid);
2544         }
2545 #endif
2546
2547 #if !BB_MMU
2548         if (!(opt & OPT_FOREGROUND)) {
2549                 bb_daemonize_or_rexec(0, argv); /* don't change current directory */
2550         }
2551 #endif
2552
2553         xchdir(home_httpd);
2554         if (!(opt & OPT_INETD)) {
2555                 signal(SIGCHLD, SIG_IGN);
2556                 server_socket = openServer();
2557 #if ENABLE_FEATURE_HTTPD_SETUID
2558                 /* drop privileges */
2559                 if (opt & OPT_SETUID) {
2560                         if (ugid.gid != (gid_t)-1) {
2561                                 if (setgroups(1, &ugid.gid) == -1)
2562                                         bb_perror_msg_and_die("setgroups");
2563                                 xsetgid(ugid.gid);
2564                         }
2565                         xsetuid(ugid.uid);
2566                 }
2567 #endif
2568         }
2569
2570 #if 0
2571         /* User can do it himself: 'env - PATH="$PATH" httpd'
2572          * We don't do it because we don't want to screw users
2573          * which want to do
2574          * 'env - VAR1=val1 VAR2=val2 httpd'
2575          * and have VAR1 and VAR2 values visible in their CGIs.
2576          * Besides, it is also smaller. */
2577         {
2578                 char *p = getenv("PATH");
2579                 /* env strings themself are not freed, no need to xstrdup(p): */
2580                 clearenv();
2581                 if (p)
2582                         putenv(p - 5);
2583 //              if (!(opt & OPT_INETD))
2584 //                      setenv_long("SERVER_PORT", ???);
2585         }
2586 #endif
2587
2588         parse_conf(DEFAULT_PATH_HTTPD_CONF, FIRST_PARSE);
2589         if (!(opt & OPT_INETD))
2590                 signal(SIGHUP, sighup_handler);
2591
2592         xfunc_error_retval = 0;
2593         if (opt & OPT_INETD)
2594                 mini_httpd_inetd();
2595 #if BB_MMU
2596         if (!(opt & OPT_FOREGROUND))
2597                 bb_daemonize(0); /* don't change current directory */
2598         mini_httpd(server_socket); /* never returns */
2599 #else
2600         mini_httpd_nommu(server_socket, argc, argv); /* never returns */
2601 #endif
2602         /* return 0; */
2603 }