User-Agent header no longer needs a leading space

insensitively. This fixes the problem where responses get incorrectly
marked as errors if the response header field name case doesn't happen
to match to what is in the code.

Also compare connection and transfer-encoding tokens case insensitively.

(Reference: RFC 2616: header field names are not case sensitive.)

Co-authored-by: Stefan Bühler <stbuehler@web.de>

src/client.c

@@ -379,26 +379,24 @@ static uint8_t client_parse(Client *client, int size) {
 				str = &client->buffer[client->parser_offset];
 				//printf("checking header: '%s'\n", str);
 
-				if (strncmp(str, "Content-Length: ", sizeof("Content-Length: ")-1) == 0) {
+				if (strncasecmp(str, "Content-Length: ", sizeof("Content-Length: ")-1) == 0) {
 					/* content length header */
 					client->content_length = str_to_uint64(str + sizeof("Content-Length: ") - 1);
-				} else if (strncmp(str, "Connection: ", sizeof("Connection: ")-1) == 0) {
+				} else if (strncasecmp(str, "Connection: ", sizeof("Connection: ")-1) == 0) {
 					/* connection header */
 					str += sizeof("Connection: ") - 1;
 
-					if (strncmp(str, "close", sizeof("close")-1) == 0)
+					if (strncasecmp(str, "close", sizeof("close")-1) == 0)
 						client->keepalive = 0;
-					else if (strncmp(str, "Keep-Alive", sizeof("Keep-Alive")-1) == 0)
-						client->keepalive = client->worker->config->keep_alive;
-					else if (strncmp(str, "keep-alive", sizeof("keep-alive")-1) == 0)
+					else if (strncasecmp(str, "keep-alive", sizeof("keep-alive")-1) == 0)
 						client->keepalive = client->worker->config->keep_alive;
 					else
 						return 0;
-				} else if (strncmp(str, "Transfer-Encoding: ", sizeof("Transfer-Encoding: ")-1) == 0) {
+				} else if (strncasecmp(str, "Transfer-Encoding: ", sizeof("Transfer-Encoding: ")-1) == 0) {
 					/* transfer encoding header */
 					str += sizeof("Transfer-Encoding: ") - 1;
 
-					if (strncmp(str, "chunked", sizeof("chunked")-1) == 0)
+					if (strncasecmp(str, "chunked", sizeof("chunked")-1) == 0)
 						client->chunked = 1;
 					else
 						return 0;

src/weighttp.c

@@ -76,9 +76,11 @@ static char *forge_request(char *url, char keep_alive, char **host, uint16_t *po
 	uint32_t len;
 	uint8_t i;
 	uint8_t have_user_agent;
+	char *header_host;
 
 	*host = NULL;
 	*port = 0;
+	header_host = NULL;
 
 	if (strncmp(url, "http://", 7) == 0)
 		url += 7;
@@ -137,8 +139,27 @@ static char *forge_request(char *url, char keep_alive, char **host, uint16_t *po
 
 	have_user_agent = 0;
 	for (i = 0; i < headers_num; i++) {
+		if (strncmp(headers[i], "Host:", sizeof("Host:")-1) == 0) {
+			if (header_host) {
+				W_ERROR("%s", "Duplicate Host header");
+				free(*host);
+				return NULL;
+			}
+			header_host = headers[i] + 5;
+			if (*header_host == ' ')
+				header_host++;
+
+			if (strlen(header_host) == 0) {
+				W_ERROR("%s", "Invalid Host header");
+				free(*host);
+				return NULL;
+			}
+
+			len += strlen(header_host);
+			continue;
+		}
 		len += strlen(headers[i]) + strlen("\r\n");
-		if (strncmp(headers[i], "User-Agent: ", sizeof("User-Agent: ")-1) == 0)
+		if (strncmp(headers[i], "User-Agent:", sizeof("User-Agent:")-1) == 0)
 			have_user_agent = 1;
 	}
 
@@ -150,9 +171,13 @@ static char *forge_request(char *url, char keep_alive, char **host, uint16_t *po
 	strcpy(req, "GET ");
 	strcat(req, url);
 	strcat(req, " HTTP/1.1\r\nHost: ");
-	strcat(req, *host);
-	if (*port != 80)
-		sprintf(req + strlen(req), ":%"PRIu16, *port);
+	if (header_host) {
+		strcat(req, header_host);
+	} else {
+		strcat(req, *host);
+		if (*port != 80)
+			sprintf(req + strlen(req), ":%"PRIu16, *port);
+	}
 
 	strcat(req, "\r\n");
 
@@ -160,6 +185,8 @@ static char *forge_request(char *url, char keep_alive, char **host, uint16_t *po
 		sprintf(req + strlen(req), "User-Agent: weighttp/" VERSION "\r\n");
 
 	for (i = 0; i < headers_num; i++) {
+		if (strncmp(headers[i], "Host:", sizeof("Host:")-1) == 0)
+			continue;
 		strcat(req, headers[i]);
 		strcat(req, "\r\n");
 	}