httpd: move proxy check before URL duplication and request type check

This makes proxy work for any type of requests.

function                                             old     new   delta
handle_incoming_and_exit                            2240    2172     -68

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

networking/httpd.c

@@ -2190,6 +2190,9 @@ static void handle_incoming_and_exit(const len_and_sockaddr *fromAddr)
 		CGI_INTERPRETER,
 	} cgi_type = CGI_NONE;
 #endif
+#if ENABLE_FEATURE_HTTPD_PROXY
+	Htaccess_Proxy *proxy_entry;
+#endif
 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
 	smallint authorized = -1;
 #endif
@@ -2231,36 +2234,16 @@ static void handle_incoming_and_exit(const len_and_sockaddr *fromAddr)
 	if (!get_line()) /* EOF or error or empty line */
 		send_headers_and_exit(HTTP_BAD_REQUEST);
 
-	/* Determine type of request (GET/POST/...) */
+	/* Find URL */
 	// rfc2616: method and URI is separated by exactly one space
 	//urlp = strpbrk(iobuf, " \t"); - no, tab isn't allowed
 	urlp = strchr(iobuf, ' ');
 	if (urlp == NULL)
 		send_headers_and_exit(HTTP_BAD_REQUEST);
 	*urlp++ = '\0';
-#if ENABLE_FEATURE_HTTPD_CGI
-	prequest = request_GET;
-	if (strcasecmp(iobuf, prequest) == 0)
-		goto found;
-	prequest = request_HEAD;
-	if (strcasecmp(iobuf, prequest) == 0)
-		goto found;
-	prequest = request_POST;
-	if (strcasecmp(iobuf, prequest) == 0)
-		goto found;
-	/* For CGI, allow other requests too (DELETE, PUT, OPTIONS, etc) */
-	prequest = alloca(16);
-	safe_strncpy((char*)prequest, iobuf, 16);
- found:
-#else
-	if (strcasecmp(iobuf, "GET") != 0)
-		send_headers_and_exit(HTTP_NOT_IMPLEMENTED);
-#endif
-	// rfc2616: method and URI is separated by exactly one space
 	//urlp = skip_whitespace(urlp); - should not be necessary
 	if (urlp[0] != '/')
 		send_headers_and_exit(HTTP_BAD_REQUEST);
-
 	/* Find end of URL */
 	HTTP_slash = strchr(urlp, ' ');
 	/* Is it " HTTP/"? */
@@ -2268,22 +2251,14 @@ static void handle_incoming_and_exit(const len_and_sockaddr *fromAddr)
 		send_headers_and_exit(HTTP_BAD_REQUEST);
 	*HTTP_slash++ = '\0';
 
-	/* Copy URL from after "GET "/"POST " to stack-allocated char[] */
-	urlcopy = alloca((HTTP_slash - 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 */
-
 #if ENABLE_FEATURE_HTTPD_PROXY
-	{
+	proxy_entry = find_proxy_entry(urlp);
+	if (proxy_entry) {
 		int proxy_fd;
 		len_and_sockaddr *lsa;
-		Htaccess_Proxy *proxy_entry = find_proxy_entry(urlcopy);
 
-		if (proxy_entry) {
 		if (verbose > 1)
-				bb_error_msg("proxy:%s", urlcopy);
+			bb_error_msg("proxy:%s", urlp);
 		lsa = host2sockaddr(proxy_entry->host_port, 80);
 		if (!lsa)
 			send_headers_and_exit(HTTP_INTERNAL_SERVER_ERROR);
@@ -2302,14 +2277,37 @@ static void handle_incoming_and_exit(const len_and_sockaddr *fromAddr)
 		fdprintf(proxy_fd, "%s %s%s %s\r\n",
 				iobuf, /* "GET" / "POST" / etc */
 				proxy_entry->url_to, /* "/new/path" */
-					urlcopy + strlen(proxy_entry->url_from), /* "SFX" */
+				urlp + strlen(proxy_entry->url_from), /* "SFX" */
 				HTTP_slash /* "HTTP/xyz" */
 		);
 		cgi_io_loop_and_exit(proxy_fd, proxy_fd, /*max POST length:*/ INT_MAX);
 	}
-	}
 #endif
 
+	/* Determine type of request (GET/POST/...) */
+#if ENABLE_FEATURE_HTTPD_CGI
+	prequest = request_GET;
+	if (strcasecmp(iobuf, prequest) == 0)
+		goto found;
+	prequest = request_HEAD;
+	if (strcasecmp(iobuf, prequest) == 0)
+		goto found;
+	prequest = request_POST;
+	if (strcasecmp(iobuf, prequest) == 0)
+		goto found;
+	/* For CGI, allow DELETE, PUT, OPTIONS, etc too */
+	prequest = alloca(16);
+	safe_strncpy((char*)prequest, iobuf, 16);
+ found:
+#else
+	if (strcasecmp(iobuf, "GET") != 0)
+		send_headers_and_exit(HTTP_NOT_IMPLEMENTED);
+#endif
+	/* Copy URL to stack-allocated char[] */
+	urlcopy = alloca((HTTP_slash - urlp) + 2 + strlen(index_page));
+	strcpy(urlcopy, urlp);
+	/* NB: urlcopy ptr is never changed after this */
+
 	/* Extract url args if present */
 	g_query = strchr(urlcopy, '?');
 	if (g_query)
@@ -2571,9 +2569,8 @@ static void handle_incoming_and_exit(const len_and_sockaddr *fromAddr)
 		send_headers_and_exit(HTTP_UNAUTHORIZED);
 #endif
 
-	if (found_moved_temporarily) {
+	if (found_moved_temporarily)
 		send_headers_and_exit(HTTP_MOVED_TEMPORARILY);
-	}
 
 	tptr = urlcopy + 1;      /* skip first '/' */
 
@@ -2587,9 +2584,8 @@ static void handle_incoming_and_exit(const len_and_sockaddr *fromAddr)
 	}
 #endif
 
-	if (urlp[-1] == '/') {
+	if (urlp[-1] == '/')
 		strcpy(urlp, index_page);
-	}
 
 #if ENABLE_FEATURE_HTTPD_CGI
 	if (prequest != request_GET && prequest != request_HEAD) {