Libevent2 fix: bad default line-extracting strategy

Libevent 2 deprecates evbuffer_readline() function, where any sequence
of any number of carriage return and linefeed characters is treated like
end of line, and introduces better evbuffer_readln(), where termination
format can be explicitly set to: \n, [\r]\n, \r\n or already mentioned
old behaviour.

Change past evbuffer_readline() calls to new
redsocks_evbuffer_readline() function. If libevent 2 is present, use
there evbuffer_readln() with eol_style set to an optional carriage
return, followed by a linefeed (EVBUFFER_EOL_CRLF) instead of obsolete
evbuffer_readln().

  Important note:
Consuming all CR and LF characters in one go (behaviour of
evbuffer_readline(), nowadays aliasing to evbuffer_readln() with
eol_style set to EVBUFFER_EOL_ANY) hangs up parsing of HTTP request
header ending with "\r\n\r\n", because it misses the empty line.

Conflicts (resolved):

	utils.c
	utils.h

http-connect.c

@@ -64,7 +64,7 @@ static char *get_auth_request_header(struct evbuffer *buf)
 {
 	char *line;
 	for (;;) {
-		line = evbuffer_readline(buf);
+		line = redsocks_evbuffer_readline(buf);
 		if (line == NULL || *line == '\0' || strchr(line, ':') == NULL) {
 			free(line);
 			return NULL;
@@ -86,7 +86,7 @@ static void httpc_read_cb(struct bufferevent *buffev, void *_arg)
 
 	if (client->state == httpc_request_sent) {
 		size_t len = EVBUFFER_LENGTH(buffev->input);
-		char *line = evbuffer_readline(buffev->input);
+		char *line = redsocks_evbuffer_readline(buffev->input);
 		if (line) {
 			unsigned int code;
 			if (sscanf(line, "HTTP/%*u.%*u %u", &code) == 1) { // 1 == one _assigned_ match
@@ -163,7 +163,7 @@ static void httpc_read_cb(struct bufferevent *buffev, void *_arg)
 		return;
 
 	while (client->state == httpc_reply_came) {
-		char *line = evbuffer_readline(buffev->input);
+		char *line = redsocks_evbuffer_readline(buffev->input);
 		if (line) {
 			if (strlen(line) == 0) {
 				client->state = httpc_headers_skipped;

http-relay.c

@@ -130,7 +130,7 @@ static char *get_auth_request_header(struct evbuffer *buf)
 {
 	char *line;
 	for (;;) {
-		line = evbuffer_readline(buf);
+		line = redsocks_evbuffer_readline(buf);
 		if (line == NULL || *line == '\0' || strchr(line, ':') == NULL) {
 			free(line);
 			return NULL;
@@ -156,7 +156,7 @@ static void httpr_relay_read_cb(struct bufferevent *buffev, void *_arg)
 
 	if (client->state == httpr_request_sent) {
 		size_t len = EVBUFFER_LENGTH(buffev->input);
-		char *line = evbuffer_readline(buffev->input);
+		char *line = redsocks_evbuffer_readline(buffev->input);
 		if (line) {
 			httpr_buffer_append(&httpr->relay_buffer, line, strlen(line));
 			httpr_buffer_append(&httpr->relay_buffer, "\r\n", 2);
@@ -236,7 +236,7 @@ static void httpr_relay_read_cb(struct bufferevent *buffev, void *_arg)
 		return;
 
 	while (client->state == httpr_reply_came) {
-		char *line = evbuffer_readline(buffev->input);
+		char *line = redsocks_evbuffer_readline(buffev->input);
 		if (line) {
 			httpr_buffer_append(&httpr->relay_buffer, line, strlen(line));
 			httpr_buffer_append(&httpr->relay_buffer, "\r\n", 2);
@@ -491,7 +491,7 @@ static void httpr_client_read_cb(struct bufferevent *buffev, void *_arg)
 	char *line = NULL;
 	int connect_relay = 0;
 
-	while (!connect_relay && (line = evbuffer_readline(buffev->input))) {
+	while (!connect_relay && (line = redsocks_evbuffer_readline(buffev->input))) {
 		int skip_line = 0;
 		int do_drop = 0;
 

utils.c

@@ -60,6 +60,15 @@ time_t redsocks_time(time_t *t)
 	return retval;
 }
 
+char *redsocks_evbuffer_readline(struct evbuffer *buf)
+{
+#if _EVENT_NUMERIC_VERSION >= 0x02000000
+	return evbuffer_readln(buf, NULL, EVBUFFER_EOL_CRLF);
+#else
+	return evbuffer_readline(buf);
+#endif
+}
+
 struct bufferevent* red_connect_relay(struct sockaddr_in *addr, evbuffercb writecb, everrorcb errorcb, void *cbarg)
 {
 	struct bufferevent *retval = NULL;

utils.h

@@ -32,6 +32,7 @@ struct sockaddr_in;
 	(type *)( (char *)__mptr - offsetof(type,member) );})
 
 time_t redsocks_time(time_t *t);
+char *redsocks_evbuffer_readline(struct evbuffer *buf);
 struct bufferevent* red_connect_relay(struct sockaddr_in *addr, evbuffercb writecb, everrorcb errorcb, void *cbarg);
 int red_socket_geterrno(struct bufferevent *buffev);
 int red_is_socket_connected_ok(struct bufferevent *buffev);