*: add optimization barrier to all "G trick" locations
[oweals/busybox.git] / networking / httpd.c
index 92a07107dc12742de776bb7f72141780e43a4285..de84ccaa2a196d5e81b1e730cf3757943b1ac0c6 100644 (file)
  * A:127.0.0.1       # Allow local loopback connections
  * D:*               # Deny from other IP connections
  * E404:/path/e404.html # /path/e404.html is the 404 (not found) error page
+ * I:index.html      # Show index.html when a directory is requested
+ *
+ * P:/url:[http://]hostname[:port]/new/path
+ *                   # When /urlXXXXXX is requested, reverse proxy
+ *                   # it to http://hostname[:port]/new/pathXXXXXX
+ *
  * /cgi-bin:foo:bar  # Require user foo, pwd bar on urls starting with /cgi-bin/
  * /adm:admin:setup  # Require user admin, pwd setup on urls starting with /adm/
  * /adm:toor:PaSsWd  # or user toor, pwd PaSsWd on urls starting with /adm/
@@ -139,6 +145,14 @@ typedef struct Htaccess_IP {
        int allow_deny;
 } Htaccess_IP;
 
+/* Must have "next" as a first member */
+typedef struct Htaccess_Proxy {
+       struct Htaccess_Proxy *next;
+       char *url_from;
+       char *host_port;
+       char *url_to;
+} Htaccess_Proxy;
+
 enum {
        HTTP_OK = 200,
        HTTP_PARTIAL_CONTENT = 206,
@@ -175,7 +189,7 @@ static const uint16_t http_response_type[] ALIGN2 = {
        HTTP_MOVED_TEMPORARILY,
        HTTP_REQUEST_TIMEOUT,
        HTTP_NOT_IMPLEMENTED,
-#if ENABLE_FEATURE_HTTPD_BASIC_AUTH 
+#if ENABLE_FEATURE_HTTPD_BASIC_AUTH
        HTTP_UNAUTHORIZED,
 #endif
        HTTP_NOT_FOUND,
@@ -237,6 +251,7 @@ struct globals {
        const char *g_query;
        const char *configFile;
        const char *home_httpd;
+       const char *index_page;
 
        const char *found_mime_type;
        const char *found_moved_temporarily;
@@ -270,6 +285,9 @@ struct globals {
 #if ENABLE_FEATURE_HTTPD_ERROR_PAGES
        const char *http_error_page[ARRAY_SIZE(http_response_type)];
 #endif
+#if ENABLE_FEATURE_HTTPD_PROXY
+       Htaccess_Proxy *proxy;
+#endif
 };
 #define G (*ptr_to_globals)
 #define verbose           (G.verbose          )
@@ -279,6 +297,7 @@ struct globals {
 #define g_query           (G.g_query          )
 #define configFile        (G.configFile       )
 #define home_httpd        (G.home_httpd       )
+#define index_page        (G.index_page       )
 #define found_mime_type   (G.found_mime_type  )
 #define found_moved_temporarily (G.found_moved_temporarily)
 #define last_mod          (G.last_mod         )
@@ -301,8 +320,9 @@ struct globals {
 #define hdr_ptr           (G.hdr_ptr          )
 #define hdr_cnt           (G.hdr_cnt          )
 #define http_error_page   (G.http_error_page  )
+#define proxy             (G.proxy            )
 #define INIT_G() do { \
-       PTR_TO_GLOBALS = xzalloc(sizeof(G)); \
+       SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
        USE_FEATURE_HTTPD_BASIC_AUTH(g_realm = "Web Server Authentication";) \
        bind_addr_or_port = "80"; \
        file_size = -1; \
@@ -320,7 +340,12 @@ enum {
 #define STRNCASECMP(a, str) strncasecmp((a), (str), sizeof(str)-1)
 
 /* Prototypes */
-static void send_file_and_exit(const char *url, int headers) ATTRIBUTE_NORETURN;
+enum {
+       SEND_HEADERS     = (1 << 0),
+       SEND_BODY        = (1 << 1),
+       SEND_HEADERS_AND_BODY = SEND_HEADERS + SEND_BODY,
+};
+static void send_file_and_exit(const char *url, int what) ATTRIBUTE_NORETURN;
 
 static void free_llist(has_next_ptr **pptr)
 {
@@ -441,6 +466,7 @@ static int scan_ip_mask(const char *str, unsigned *ipp, unsigned *maskp)
  *    [adAD]:from      # ip address allow/deny, * for wildcard
  *    /path:user:pass  # username/password
  *    Ennn:error.html  # error page for status nnn
+ *    P:/url:[http://]hostname[:port]/new/path # reverse proxy
  *
  * Any previous IP rules are discarded.
  * If the flag argument is not SUBDIR_PARSE then all /path and mime rules
@@ -469,7 +495,7 @@ static void parse_conf(const char *path, int flag)
 #endif
        const char *cf = configFile;
        char buf[160];
-       char *p0 = NULL;
+       char *p0;
        char *c, *p;
        Htaccess_IP *pip;
 
@@ -504,7 +530,7 @@ static void parse_conf(const char *path, int flag)
                        return;
                }
                if (configFile && flag == FIRST_PARSE) /* if -c option given */
-                       bb_perror_msg_and_die("%s", cf);
+                       bb_simple_perror_msg_and_die(cf);
                flag = FIND_FROM_HTTPD_ROOT;
                cf = httpd_conf;
        }
@@ -594,6 +620,42 @@ static void parse_conf(const char *path, int flag)
                }
 #endif
 
+#if ENABLE_FEATURE_HTTPD_PROXY
+               if (flag == FIRST_PARSE && *p0 == 'P') {
+                       /* P:/url:[http://]hostname[:port]/new/path */
+                       char *url_from, *host_port, *url_to;
+                       Htaccess_Proxy *proxy_entry;
+
+                       url_from = c;
+                       host_port = strchr(c, ':');
+                       if (host_port == NULL) {
+                               bb_error_msg("config error '%s' in '%s'", buf, cf);
+                               continue;
+                       }
+                       *host_port++ = '\0';
+                       if (strncmp(host_port, "http://", 7) == 0)
+                               host_port += 7;
+                       if (*host_port == '\0') {
+                               bb_error_msg("config error '%s' in '%s'", buf, cf);
+                               continue;
+                       }
+                       url_to = strchr(host_port, '/');
+                       if (url_to == NULL) {
+                               bb_error_msg("config error '%s' in '%s'", buf, cf);
+                               continue;
+                       }
+                       *url_to = '\0';
+                       proxy_entry = xzalloc(sizeof(Htaccess_Proxy));
+                       proxy_entry->url_from = xstrdup(url_from);
+                       proxy_entry->host_port = xstrdup(host_port);
+                       *url_to = '/';
+                       proxy_entry->url_to = xstrdup(url_to);
+                       proxy_entry->next = proxy;
+                       proxy = proxy_entry;
+                       continue;
+               }
+#endif
+
 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
                if (*p0 == '/') {
                        /* make full path from httpd root / current_path / config_line_path */
@@ -609,10 +671,12 @@ static void parse_conf(const char *path, int flag)
                                if (*p == '/') {
                                        if (*cf == '/') {    /* skip duplicate (or initial) slash */
                                                continue;
-                                       } else if (*cf == '.') {
+                                       }
+                                       if (*cf == '.') {
                                                if (cf[1] == '/' || cf[1] == '\0') { /* remove extra '.' */
                                                        continue;
-                                               } else if ((cf[1] == '.') && (cf[2] == '/' || cf[2] == '\0')) {
+                                               }
+                                               if ((cf[1] == '.') && (cf[2] == '/' || cf[2] == '\0')) {
                                                        ++cf;
                                                        if (p > p0) {
                                                                while (*--p != '/') /* omit previous dir */;
@@ -627,72 +691,78 @@ static void parse_conf(const char *path, int flag)
                        if ((p == p0) || (*p != '/')) {      /* not a trailing slash */
                                ++p;                             /* so keep last character */
                        }
-                       *p = '\0';
-                       sprintf(p0 + strlen(p0), ":%s", c);
+                       *p = ':';
+                       strcpy(p + 1, c);
                }
 #endif
 
+               if (*p0 == 'I') {
+                       index_page = xstrdup(c);
+                       continue;
+               }
+
 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH \
  || ENABLE_FEATURE_HTTPD_CONFIG_WITH_MIME_TYPES \
  || ENABLE_FEATURE_HTTPD_CONFIG_WITH_SCRIPT_INTERPR
                /* storing current config line */
                cur = xzalloc(sizeof(Htaccess) + strlen(p0));
-               if (cur) {
-                       cf = strcpy(cur->before_colon, p0);
-                       c = strchr(cf, ':');
-                       *c++ = 0;
-                       cur->after_colon = c;
+               cf = strcpy(cur->before_colon, p0);
+#if ENABLE_FEATURE_HTTPD_BASIC_AUTH
+               if (*p0 == '/')
+                       free(p0);
+#endif
+               c = strchr(cf, ':');
+               *c++ = '\0';
+               cur->after_colon = c;
 #if ENABLE_FEATURE_HTTPD_CONFIG_WITH_MIME_TYPES
-                       if (*cf == '.') {
-                               /* config .mime line move top for overwrite previous */
-                               cur->next = mime_a;
-                               mime_a = cur;
-                               continue;
-                       }
+               if (*cf == '.') {
+                       /* config .mime line move top for overwrite previous */
+                       cur->next = mime_a;
+                       mime_a = cur;
+                       continue;
+               }
 #endif
 #if ENABLE_FEATURE_HTTPD_CONFIG_WITH_SCRIPT_INTERPR
-                       if (*cf == '*' && cf[1] == '.') {
-                               /* config script interpreter line move top for overwrite previous */
-                               cur->next = script_i;
-                               script_i = cur;
-                               continue;
-                       }
+               if (*cf == '*' && cf[1] == '.') {
+                       /* config script interpreter line move top for overwrite previous */
+                       cur->next = script_i;
+                       script_i = cur;
+                       continue;
+               }
 #endif
 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
-                       free(p0);
-                       if (prev == NULL) {
-                               /* first line */
-                               g_auth = prev = cur;
-                       } else {
-                               /* sort path, if current lenght eq or bigger then move up */
-                               Htaccess *prev_hti = g_auth;
-                               size_t l = strlen(cf);
-                               Htaccess *hti;
-
-                               for (hti = prev_hti; hti; hti = hti->next) {
-                                       if (l >= strlen(hti->before_colon)) {
-                                               /* insert before hti */
-                                               cur->next = hti;
-                                               if (prev_hti != hti) {
-                                                       prev_hti->next = cur;
-                                               } else {
-                                                       /* insert as top */
-                                                       g_auth = cur;
-                                               }
-                                               break;
+               if (prev == NULL) {
+                       /* first line */
+                       g_auth = prev = cur;
+               } else {
+                       /* sort path, if current length eq or bigger then move up */
+                       Htaccess *prev_hti = g_auth;
+                       size_t l = strlen(cf);
+                       Htaccess *hti;
+
+                       for (hti = prev_hti; hti; hti = hti->next) {
+                               if (l >= strlen(hti->before_colon)) {
+                                       /* insert before hti */
+                                       cur->next = hti;
+                                       if (prev_hti != hti) {
+                                               prev_hti->next = cur;
+                                       } else {
+                                               /* insert as top */
+                                               g_auth = cur;
                                        }
-                                       if (prev_hti != hti)
-                                               prev_hti = prev_hti->next;
-                               }
-                               if (!hti) {       /* not inserted, add to bottom */
-                                       prev->next = cur;
-                                       prev = cur;
+                                       break;
                                }
+                               if (prev_hti != hti)
+                                       prev_hti = prev_hti->next;
+                       }
+                       if (!hti) {       /* not inserted, add to bottom */
+                               prev->next = cur;
+                               prev = cur;
                        }
-#endif
                }
-#endif
-        }
+#endif /* BASIC_AUTH */
+#endif /* BASIC_AUTH || MIME_TYPES || SCRIPT_INTERPR */
+        } /* while (fgets) */
         fclose(f);
 }
 
@@ -850,7 +920,7 @@ static void decodeBase64(char *Data)
  */
 static int openServer(void)
 {
-       int n = bb_strtou(bind_addr_or_port, NULL, 10);
+       unsigned n = bb_strtou(bind_addr_or_port, NULL, 10);
        if (!errno && n && n <= 0xffff)
                n = create_and_bind_stream_or_die(NULL, n);
        else
@@ -892,7 +962,7 @@ static void send_headers(int responseNum)
        const char *infoString = NULL;
        const char *mime_type;
 #if ENABLE_FEATURE_HTTPD_ERROR_PAGES
-       const char *error_page = 0;
+       const char *error_page = NULL;
 #endif
        unsigned i;
        time_t timer = time(0);
@@ -947,7 +1017,7 @@ static void send_headers(int responseNum)
                full_write(1, iobuf, len);
                if (DEBUG)
                        fprintf(stderr, "writing error page: '%s'\n", error_page);
-               return send_file_and_exit(error_page, FALSE);
+               return send_file_and_exit(error_page, SEND_BODY);
        }
 #endif
 
@@ -1031,7 +1101,7 @@ static int get_line(void)
        return count;
 }
 
-#if ENABLE_FEATURE_HTTPD_CGI
+#if ENABLE_FEATURE_HTTPD_CGI || ENABLE_FEATURE_HTTPD_PROXY
 
 /* gcc 4.2.1 fares better with NOINLINE */
 static NOINLINE void cgi_io_loop_and_exit(int fromCgi_rd, int toCgi_wr, int post_len) ATTRIBUTE_NORETURN;
@@ -1049,6 +1119,17 @@ static NOINLINE void cgi_io_loop_and_exit(int fromCgi_rd, int toCgi_wr, int post
         * and send it to the peer. So please no SIGPIPEs! */
        signal(SIGPIPE, SIG_IGN);
 
+       // We inconsistently handle a case when more POSTDATA from network
+       // is coming than we expected. We may give *some part* of that
+       // extra data to CGI.
+
+       //if (hdr_cnt > post_len) {
+       //      /* We got more POSTDATA from network than we expected */
+       //      hdr_cnt = post_len;
+       //}
+       post_len -= hdr_cnt;
+       /* post_len - number of POST bytes not yet read from network */
+
        /* NB: breaking out of this loop jumps to log_and_exit() */
        out_cnt = 0;
        while (1) {
@@ -1076,7 +1157,7 @@ static NOINLINE void cgi_io_loop_and_exit(int fromCgi_rd, int toCgi_wr, int post
                count = safe_poll(pfd, 3, -1);
                if (count <= 0) {
 #if 0
-                       if (waitpid(pid, &status, WNOHANG) <= 0) {
+                       if (safe_waitpid(pid, &status, WNOHANG) <= 0) {
                                /* Weird. CGI didn't exit and no fd's
                                 * are ready, yet poll returned?! */
                                continue;
@@ -1194,6 +1275,9 @@ static NOINLINE void cgi_io_loop_and_exit(int fromCgi_rd, int toCgi_wr, int post
        } /* while (1) */
        log_and_exit();
 }
+#endif
+
+#if ENABLE_FEATURE_HTTPD_CGI
 
 static void setenv1(const char *name, const char *value)
 {
@@ -1226,8 +1310,8 @@ static void send_cgi_and_exit(
                const char *cookie,
                const char *content_type)
 {
-       struct { int rd; int wr; } fromCgi;  /* CGI -> httpd pipe */
-       struct { int rd; int wr; } toCgi;    /* httpd -> CGI pipe */
+       struct fd_pair fromCgi;  /* CGI -> httpd pipe */
+       struct fd_pair toCgi;    /* httpd -> CGI pipe */
        char *fullpath;
        char *script;
        char *purl;
@@ -1317,8 +1401,8 @@ static void send_cgi_and_exit(
        if (referer)
                setenv1("HTTP_REFERER", referer);
 
-       xpipe(&fromCgi.rd);
-       xpipe(&toCgi.rd);
+       xpiped_pair(fromCgi);
+       xpiped_pair(toCgi);
 
        pid = vfork();
        if (pid < 0) {
@@ -1330,48 +1414,55 @@ static void send_cgi_and_exit(
                /* Child process */
                xfunc_error_retval = 242;
 
+               /* NB: close _first_, then move fds! */
+               close(toCgi.wr);
+               close(fromCgi.rd);
                xmove_fd(toCgi.rd, 0);  /* replace stdin with the pipe */
                xmove_fd(fromCgi.wr, 1);  /* replace stdout with the pipe */
-               close(fromCgi.rd);
-               close(toCgi.wr);
                /* User seeing stderr output can be a security problem.
                 * If CGI really wants that, it can always do dup itself. */
                /* dup2(1, 2); */
 
-               /* script must have absolute path */
                script = strrchr(fullpath, '/');
-               if (!script)
-                       goto error_execing_cgi;
+               //fullpath is a result of concat_path_file and always has '/'
+               //if (!script)
+               //      goto error_execing_cgi;
                *script = '\0';
                /* chdiring to script's dir */
-               if (chdir(fullpath) == 0) {
-                       char *argv[2];
+               if (chdir(script == fullpath ? "/" : fullpath) == 0) {
+                       char *argv[3];
+
+                       *script++ = '/'; /* repair fullpath */
+                       /* set argv[0] to name without path */
+                       argv[0] = script;
+                       argv[1] = NULL;
+
 #if ENABLE_FEATURE_HTTPD_CONFIG_WITH_SCRIPT_INTERPR
-                       char *interpr = NULL;
-                       char *suffix = strrchr(purl, '.');
-
-                       if (suffix) {
-                               Htaccess *cur;
-                               for (cur = script_i; cur; cur = cur->next) {
-                                       if (strcmp(cur->before_colon + 1, suffix) == 0) {
-                                               interpr = cur->after_colon;
-                                               break;
+                       {
+                               char *suffix = strrchr(script, '.');
+
+                               if (suffix) {
+                                       Htaccess *cur;
+                                       for (cur = script_i; cur; cur = cur->next) {
+                                               if (strcmp(cur->before_colon + 1, suffix) == 0) {
+                                                       /* found interpreter name */
+                                                       fullpath = cur->after_colon;
+                                                       argv[0] = cur->after_colon;
+                                                       argv[1] = script;
+                                                       argv[2] = NULL;
+                                                       break;
+                                               }
                                        }
                                }
                        }
 #endif
-                       *script = '/';
-                       /* set argv[0] to name without path */
-                       argv[0] = (char*)bb_basename(purl);
-                       argv[1] = NULL;
-#if ENABLE_FEATURE_HTTPD_CONFIG_WITH_SCRIPT_INTERPR
-                       if (interpr)
-                               execv(interpr, argv);
-                       else
-#endif
-                               execv(fullpath, argv);
+                       execv(fullpath, argv);
+                       if (verbose)
+                               bb_perror_msg("exec %s", fullpath);
+               } else if (verbose) {
+                       bb_perror_msg("chdir %s", fullpath);
                }
- error_execing_cgi:
//error_execing_cgi:
                /* send to stdout
                 * (we are CGI here, our stdout is pumped to the net) */
                send_headers_and_exit(HTTP_NOT_FOUND);
@@ -1392,12 +1483,12 @@ static void send_cgi_and_exit(
 
 /*
  * Send a file response to a HTTP request, and exit
- * 
+ *
  * Parameters:
- * const char *url    The requested URL (with leading /).
- * headers            Don't send headers before if FALSE.
+ * const char *url  The requested URL (with leading /).
+ * what             What to send (headers/body/both).
  */
-static void send_file_and_exit(const char *url, int headers)
+static void send_file_and_exit(const char *url, int what)
 {
        static const char *const suffixTable[] = {
        /* Warning: shorter equivalent suffix in one line must be first */
@@ -1430,6 +1521,10 @@ static void send_file_and_exit(const char *url, int headers)
        off_t offset;
 #endif
 
+       /* If you want to know about EPIPE below
+        * (happens if you abort downloads from local httpd): */
+       signal(SIGPIPE, SIG_IGN);
+
        suffix = strrchr(url, '.');
 
        /* If not found, set default as "application/octet-stream";  */
@@ -1466,11 +1561,15 @@ static void send_file_and_exit(const char *url, int headers)
        if (f < 0) {
                if (DEBUG)
                        bb_perror_msg("cannot open '%s'", url);
-               if (headers)
+               /* Error pages are sent by using send_file_and_exit(SEND_BODY).
+                * IOW: it is unsafe to call send_headers_and_exit
+                * if what is SEND_BODY! Can recurse! */
+               if (what != SEND_BODY)
                        send_headers_and_exit(HTTP_NOT_FOUND);
+               log_and_exit();
        }
 #if ENABLE_FEATURE_HTTPD_RANGES
-       if (!headers)
+       if (what == SEND_BODY)
                range_start = 0; /* err pages and ranges don't mix */
        range_len = MAXINT(off_t);
        if (range_start) {
@@ -1485,18 +1584,14 @@ static void send_file_and_exit(const char *url, int headers)
                } else {
                        range_len = range_end - range_start + 1;
                        send_headers(HTTP_PARTIAL_CONTENT);
-                       headers = 0;
+                       what = SEND_BODY;
                }
        }
 #endif
 
-       if (headers)
+       if (what & SEND_HEADERS)
                send_headers(HTTP_OK);
 
-       /* If you want to know about EPIPE below
-        * (happens if you abort downloads from local httpd): */
-       signal(SIGPIPE, SIG_IGN);
-
 #if ENABLE_FEATURE_HTTPD_USE_SENDFILE
        offset = range_start;
        do {
@@ -1642,6 +1737,18 @@ static int checkPerm(const char *path, const char *request)
 }
 #endif  /* FEATURE_HTTPD_BASIC_AUTH */
 
+#if ENABLE_FEATURE_HTTPD_PROXY
+static Htaccess_Proxy *find_proxy_entry(const char *url)
+{
+       Htaccess_Proxy *p;
+       for (p = proxy; p; p = p->next) {
+               if (strncmp(url, p->url_from, strlen(p->url_from)) == 0)
+                       return p;
+       }
+       return NULL;
+}
+#endif
+
 /*
  * Handle timeouts
  */
@@ -1658,18 +1765,27 @@ static void handle_incoming_and_exit(const len_and_sockaddr *fromAddr) ATTRIBUTE
 static void handle_incoming_and_exit(const len_and_sockaddr *fromAddr)
 {
        static const char request_GET[] ALIGN1 = "GET";
-
        struct stat sb;
        char *urlcopy;
        char *urlp;
        char *tptr;
-       int http_major_version;
        int ip_allowed;
 #if ENABLE_FEATURE_HTTPD_CGI
+       static const char request_HEAD[] ALIGN1 = "HEAD";
        const char *prequest;
+       char *cookie = NULL;
+       char *content_type = NULL;
+       unsigned long length = 0;
+#elif ENABLE_FEATURE_HTTPD_PROXY
+#define prequest request_GET
        unsigned long length = 0;
-       char *cookie = 0;
-       char *content_type = 0;
+#endif
+       char http_major_version;
+#if ENABLE_FEATURE_HTTPD_PROXY
+       char http_minor_version;
+       char *header_buf = header_buf; /* for gcc */
+       char *header_ptr = header_ptr;
+       Htaccess_Proxy *proxy_entry;
 #endif
        struct sigaction sa;
 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
@@ -1681,18 +1797,18 @@ static void handle_incoming_and_exit(const len_and_sockaddr *fromAddr)
        iobuf = xmalloc(IOBUF_SIZE);
 
        rmt_ip = 0;
-       if (fromAddr->sa.sa_family == AF_INET) {
-               rmt_ip = ntohl(fromAddr->sin.sin_addr.s_addr);
+       if (fromAddr->u.sa.sa_family == AF_INET) {
+               rmt_ip = ntohl(fromAddr->u.sin.sin_addr.s_addr);
        }
 #if ENABLE_FEATURE_IPV6
-       if (fromAddr->sa.sa_family == AF_INET6
-        && fromAddr->sin6.sin6_addr.s6_addr32[0] == 0
-        && fromAddr->sin6.sin6_addr.s6_addr32[1] == 0
-        && ntohl(fromAddr->sin6.sin6_addr.s6_addr32[2]) == 0xffff)
-               rmt_ip = ntohl(fromAddr->sin6.sin6_addr.s6_addr32[3]);
+       if (fromAddr->u.sa.sa_family == AF_INET6
+        && fromAddr->u.sin6.sin6_addr.s6_addr32[0] == 0
+        && fromAddr->u.sin6.sin6_addr.s6_addr32[1] == 0
+        && ntohl(fromAddr->u.sin6.sin6_addr.s6_addr32[2]) == 0xffff)
+               rmt_ip = ntohl(fromAddr->u.sin6.sin6_addr.s6_addr32[3]);
 #endif
        if (ENABLE_FEATURE_HTTPD_CGI || DEBUG || verbose) {
-               rmt_ip_str = xmalloc_sockaddr2dotted(&fromAddr->sa);
+               rmt_ip_str = xmalloc_sockaddr2dotted(&fromAddr->u.sa);
        }
        if (verbose) {
                /* this trick makes -v logging much simpler */
@@ -1720,9 +1836,12 @@ static void handle_incoming_and_exit(const len_and_sockaddr *fromAddr)
 #if ENABLE_FEATURE_HTTPD_CGI
        prequest = request_GET;
        if (strcasecmp(iobuf, prequest) != 0) {
-               prequest = "POST";
-               if (strcasecmp(iobuf, prequest) != 0)
-                       send_headers_and_exit(HTTP_NOT_IMPLEMENTED);
+               prequest = request_HEAD;
+               if (strcasecmp(iobuf, prequest) != 0) {
+                       prequest = "POST";
+                       if (strcasecmp(iobuf, prequest) != 0)
+                               send_headers_and_exit(HTTP_NOT_IMPLEMENTED);
+               }
        }
 #else
        if (strcasecmp(iobuf, request_GET) != 0)
@@ -1733,23 +1852,26 @@ static void handle_incoming_and_exit(const len_and_sockaddr *fromAddr)
                send_headers_and_exit(HTTP_BAD_REQUEST);
 
        /* Find end of URL and parse HTTP version, if any */
-       http_major_version = -1;
+       http_major_version = '0';
+       USE_FEATURE_HTTPD_PROXY(http_minor_version = '0';)
        tptr = strchrnul(urlp, ' ');
        /* Is it " HTTP/"? */
-       if (tptr[0] && strncmp(tptr + 1, HTTP_200, 5) == 0)
-               http_major_version = (tptr[6] - '0');
+       if (tptr[0] && strncmp(tptr + 1, HTTP_200, 5) == 0) {
+               http_major_version = tptr[6];
+               USE_FEATURE_HTTPD_PROXY(http_minor_version = tptr[8];)
+       }
        *tptr = '\0';
 
        /* Copy URL from after "GET "/"POST " to stack-allocated char[] */
-       urlcopy = alloca((tptr - urlp) + sizeof("/index.html"));
+       urlcopy = alloca((tptr - urlp) + 2 + strlen(index_page));
        /*if (urlcopy == NULL)
         *      send_headers_and_exit(HTTP_INTERNAL_SERVER_ERROR);*/
        strcpy(urlcopy, urlp);
        /* NB: urlcopy ptr is never changed after this */
 
        /* Extract url args if present */
-       tptr = strchr(urlcopy, '?');
        g_query = NULL;
+       tptr = strchr(urlcopy, '?');
        if (tptr) {
                *tptr++ = '\0';
                g_query = tptr;
@@ -1817,7 +1939,14 @@ static void handle_incoming_and_exit(const len_and_sockaddr *fromAddr)
                }
                *tptr = '/';
        }
-       if (http_major_version >= 0) {
+
+#if ENABLE_FEATURE_HTTPD_PROXY
+       proxy_entry = find_proxy_entry(urlcopy);
+       if (proxy_entry)
+               header_buf = header_ptr = xmalloc(IOBUF_SIZE);
+#endif
+
+       if (http_major_version >= '0') {
                /* Request was with "... HTTP/nXXX", and n >= 0 */
 
                /* Read until blank line for HTTP version specified, else parse immediate */
@@ -1828,24 +1957,39 @@ static void handle_incoming_and_exit(const len_and_sockaddr *fromAddr)
                        if (DEBUG)
                                bb_error_msg("header: '%s'", iobuf);
 
-#if ENABLE_FEATURE_HTTPD_CGI
-                       /* try and do our best to parse more lines */
+#if ENABLE_FEATURE_HTTPD_PROXY
+                       /* We need 2 more bytes for yet another "\r\n" -
+                        * see near fdprintf(proxy_fd...) further below */
+                       if (proxy_entry && (header_ptr - header_buf) < IOBUF_SIZE - 2) {
+                               int len = strlen(iobuf);
+                               if (len > IOBUF_SIZE - (header_ptr - header_buf) - 4)
+                                       len = IOBUF_SIZE - (header_ptr - header_buf) - 4;
+                               memcpy(header_ptr, iobuf, len);
+                               header_ptr += len;
+                               header_ptr[0] = '\r';
+                               header_ptr[1] = '\n';
+                               header_ptr += 2;
+                       }
+#endif
+
+#if ENABLE_FEATURE_HTTPD_CGI || ENABLE_FEATURE_HTTPD_PROXY
+                       /* Try and do our best to parse more lines */
                        if ((STRNCASECMP(iobuf, "Content-length:") == 0)) {
                                /* extra read only for POST */
-                               if (prequest != request_GET) {
+                               if (prequest != request_GET && prequest != request_HEAD) {
                                        tptr = iobuf + sizeof("Content-length:") - 1;
                                        if (!tptr[0])
                                                send_headers_and_exit(HTTP_BAD_REQUEST);
-                                       errno = 0;
                                        /* not using strtoul: it ignores leading minus! */
-                                       length = strtol(tptr, &tptr, 10);
+                                       length = bb_strtou(tptr, NULL, 10);
                                        /* length is "ulong", but we need to pass it to int later */
-                                       /* so we check for negative or too large values in one go: */
-                                       /* (long -> ulong conv caused negatives to be seen as > INT_MAX) */
-                                       if (tptr[0] || errno || length > INT_MAX)
+                                       if (errno || length > INT_MAX)
                                                send_headers_and_exit(HTTP_BAD_REQUEST);
                                }
-                       } else if (STRNCASECMP(iobuf, "Cookie:") == 0) {
+                       }
+#endif
+#if ENABLE_FEATURE_HTTPD_CGI
+                       else if (STRNCASECMP(iobuf, "Cookie:") == 0) {
                                cookie = strdup(skip_whitespace(iobuf + sizeof("Cookie:")-1));
                        } else if (STRNCASECMP(iobuf, "Content-Type:") == 0) {
                                content_type = strdup(skip_whitespace(iobuf + sizeof("Content-Type:")-1));
@@ -1872,7 +2016,7 @@ static void handle_incoming_and_exit(const len_and_sockaddr *fromAddr)
 #endif          /* FEATURE_HTTPD_BASIC_AUTH */
 #if ENABLE_FEATURE_HTTPD_RANGES
                        if (STRNCASECMP(iobuf, "Range:") == 0) {
-                               // We know only bytes=NNN-[MMM]
+                               /* We know only bytes=NNN-[MMM] */
                                char *s = skip_whitespace(iobuf + sizeof("Range:")-1);
                                if (strncmp(s, "bytes=", 6) == 0) {
                                        s += sizeof("bytes=")-1;
@@ -1890,7 +2034,7 @@ static void handle_incoming_and_exit(const len_and_sockaddr *fromAddr)
                } /* while extra header reading */
        }
 
-       /* We read headers, disable peer timeout */
+       /* We are done reading headers, disable peer timeout */
        alarm(0);
 
        if (strcmp(bb_basename(urlcopy), httpd_conf) == 0 || ip_allowed == 0) {
@@ -1908,6 +2052,36 @@ static void handle_incoming_and_exit(const len_and_sockaddr *fromAddr)
                send_headers_and_exit(HTTP_MOVED_TEMPORARILY);
        }
 
+#if ENABLE_FEATURE_HTTPD_PROXY
+       if (proxy_entry != NULL) {
+               int proxy_fd;
+               len_and_sockaddr *lsa;
+
+               proxy_fd = socket(AF_INET, SOCK_STREAM, 0);
+               if (proxy_fd < 0)
+                       send_headers_and_exit(HTTP_INTERNAL_SERVER_ERROR);
+               lsa = host2sockaddr(proxy_entry->host_port, 80);
+               if (lsa == NULL)
+                       send_headers_and_exit(HTTP_INTERNAL_SERVER_ERROR);
+               if (connect(proxy_fd, &lsa->u.sa, lsa->len) < 0)
+                       send_headers_and_exit(HTTP_INTERNAL_SERVER_ERROR);
+               fdprintf(proxy_fd, "%s %s%s%s%s HTTP/%c.%c\r\n",
+                               prequest, /* GET or POST */
+                               proxy_entry->url_to, /* url part 1 */
+                               urlcopy + strlen(proxy_entry->url_from), /* url part 2 */
+                               (g_query ? "?" : ""), /* "?" (maybe) */
+                               (g_query ? g_query : ""), /* query string (maybe) */
+                               http_major_version, http_minor_version);
+               header_ptr[0] = '\r';
+               header_ptr[1] = '\n';
+               header_ptr += 2;
+               write(proxy_fd, header_buf, header_ptr - header_buf);
+               free(header_buf); /* on the order of 8k, free it */
+               /* cgi_io_loop_and_exit needs to have two disctinct fds */
+               cgi_io_loop_and_exit(proxy_fd, dup(proxy_fd), length);
+       }
+#endif
+
        tptr = urlcopy + 1;      /* skip first '/' */
 
 #if ENABLE_FEATURE_HTTPD_CGI
@@ -1931,13 +2105,13 @@ static void handle_incoming_and_exit(const len_and_sockaddr *fromAddr)
                }
        }
 #endif
-       if (prequest != request_GET) {
+       if (prequest != request_GET && prequest != request_HEAD) {
                send_headers_and_exit(HTTP_NOT_IMPLEMENTED);
        }
 #endif  /* FEATURE_HTTPD_CGI */
 
        if (urlp[-1] == '/')
-               strcpy(urlp, "index.html");
+               strcpy(urlp, index_page);
        if (stat(tptr, &sb) == 0) {
                file_size = sb.st_size;
                last_mod = sb.st_mtime;
@@ -1958,7 +2132,8 @@ static void handle_incoming_and_exit(const len_and_sockaddr *fromAddr)
         * }
         */
 
-       send_file_and_exit(tptr, TRUE);
+       send_file_and_exit(tptr,
+               (prequest != request_HEAD ? SEND_HEADERS_AND_BODY : SEND_HEADERS));
 }
 
 /*
@@ -1979,10 +2154,10 @@ static void mini_httpd(int server_socket)
        while (1) {
                int n;
                len_and_sockaddr fromAddr;
-               
+
                /* Wait for connections... */
                fromAddr.len = LSA_SIZEOF_SA;
-               n = accept(server_socket, &fromAddr.sa, &fromAddr.len);
+               n = accept(server_socket, &fromAddr.u.sa, &fromAddr.len);
 
                if (n < 0)
                        continue;
@@ -2024,10 +2199,10 @@ static void mini_httpd_nommu(int server_socket, int argc, char **argv)
        while (1) {
                int n;
                len_and_sockaddr fromAddr;
-               
+
                /* Wait for connections... */
                fromAddr.len = LSA_SIZEOF_SA;
-               n = accept(server_socket, &fromAddr.sa, &fromAddr.len);
+               n = accept(server_socket, &fromAddr.u.sa, &fromAddr.len);
 
                if (n < 0)
                        continue;
@@ -2064,7 +2239,7 @@ static void mini_httpd_inetd(void)
        len_and_sockaddr fromAddr;
 
        fromAddr.len = LSA_SIZEOF_SA;
-       getpeername(0, &fromAddr.sa, &fromAddr.len);
+       getpeername(0, &fromAddr.u.sa, &fromAddr.len);
        handle_incoming_and_exit(&fromAddr);
 }
 
@@ -2109,7 +2284,7 @@ enum {
 };
 
 
-int httpd_main(int argc, char **argv);
+int httpd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 int httpd_main(int argc, char **argv)
 {
        int server_socket = server_socket; /* for gcc */
@@ -2198,7 +2373,7 @@ int httpd_main(int argc, char **argv)
        /* User can do it himself: 'env - PATH="$PATH" httpd'
         * We don't do it because we don't want to screw users
         * which want to do
-        * 'env - VAR1=val1 VAR2=val2 https'
+        * 'env - VAR1=val1 VAR2=val2 httpd'
         * and have VAR1 and VAR2 values visible in their CGIs.
         * Besides, it is also smaller. */
        {
@@ -2217,6 +2392,7 @@ int httpd_main(int argc, char **argv)
                sighup_handler(0);
        else /* do not install HUP handler in inetd mode */
 #endif
+               index_page = "index.html";
                parse_conf(default_path_httpd_conf, FIRST_PARSE);
 
        xfunc_error_retval = 0;