xatonum.h: add comment
[oweals/busybox.git] / networking / httpd.c
index cedec800f106c8a60c651356a8edd58f2975afad..af1f61d2dc4b87642b21bbe3994fcfda180b76e6 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
+ *
+ * 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 +144,14 @@ 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 +188,7 @@ 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,
@@ -270,6 +283,9 @@ 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          )
@@ -301,6 +317,7 @@ 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)); \
        USE_FEATURE_HTTPD_BASIC_AUTH(g_realm = "Web Server Authentication";) \
@@ -441,6 +458,7 @@ 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 +487,7 @@ 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 +522,7 @@ 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 +612,42 @@ 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)
+                               c += 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 +663,12 @@ 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 */;
@@ -627,8 +683,8 @@ 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
 
@@ -637,62 +693,63 @@ static void parse_conf(const char *path, int flag)
  || 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 +907,7 @@ 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
@@ -1031,7 +1088,7 @@ 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 +1106,17 @@ 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) {
@@ -1073,12 +1141,8 @@ static NOINLINE void cgi_io_loop_and_exit(int fromCgi_rd, int toCgi_wr, int post
                }
 
                /* Now wait on the set of sockets */
-               count = poll(pfd, 3, -1);
+               count = safe_poll(pfd, 3, -1);
                if (count <= 0) {
-#if 0
-                       if (errno == EINTR)
-                               continue;
-#endif
 #if 0
                        if (waitpid(pid, &status, WNOHANG) <= 0) {
                                /* Weird. CGI didn't exit and no fd's
@@ -1198,6 +1262,9 @@ 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)
 {
@@ -1396,7 +1463,7 @@ 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.
@@ -1646,6 +1713,18 @@ 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
  */
@@ -1667,13 +1746,22 @@ static void handle_incoming_and_exit(const len_and_sockaddr *fromAddr)
        char *urlcopy;
        char *urlp;
        char *tptr;
-       int http_major_version;
        int ip_allowed;
 #if ENABLE_FEATURE_HTTPD_CGI
        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 *headers = headers;
+       char *headers_ptr = headers_ptr;
+       Htaccess_Proxy *proxy_entry;
 #endif
        struct sigaction sa;
 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
@@ -1737,11 +1825,14 @@ 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[] */
@@ -1752,8 +1843,8 @@ static void handle_incoming_and_exit(const len_and_sockaddr *fromAddr)
        /* 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;
@@ -1821,7 +1912,14 @@ 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)
+               headers = headers_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 */
@@ -1832,8 +1930,23 @@ 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 fdprintf(proxy_fd...) further below */
+                       if (proxy_entry && headers_ptr - headers < IOBUF_SIZE - 2) {
+                               int len = strlen(iobuf);
+                               if (len > IOBUF_SIZE - (headers_ptr - headers) - 4)
+                                       len = IOBUF_SIZE - (headers_ptr - headers) - 4;
+                               memcpy(headers_ptr, iobuf, len);
+                               headers_ptr += len;
+                               headers_ptr[0] = '\r';
+                               headers_ptr[1] = '\n';
+                               headers_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) {
@@ -1849,7 +1962,10 @@ static void handle_incoming_and_exit(const len_and_sockaddr *fromAddr)
                                        if (tptr[0] || 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));
@@ -1876,7 +1992,7 @@ 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;
@@ -1894,7 +2010,7 @@ 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) {
@@ -1912,6 +2028,35 @@ 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->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);
+               headers_ptr[0] = '\r';
+               headers_ptr[1] = '\n';
+               headers_ptr += 2;
+               write(proxy_fd, headers, headers_ptr - headers);
+               /* 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
@@ -1983,7 +2128,7 @@ 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);
@@ -2028,7 +2173,7 @@ 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);
@@ -2113,7 +2258,7 @@ 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 */
@@ -2202,7 +2347,7 @@ 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. */
        {