From: Timo Sirainen <timo.sirainen@open-xchange.com>
Date: Mon, 25 Nov 2019 13:16:09 +0000 (+0200)
Subject: lib: connection: Cleanup connection_update_properties()
X-Git-Tag: 2.3.9~9
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=1c64f03b2299022a327dba91c9b6a3c30ab15493;p=thirdparty%2Fdovecot%2Fcore.git

lib: connection: Cleanup connection_update_properties()

Add comments and change the code flows a bit to make it clearer what is
supposed to happen.

Fixes also a potential bug where getpeername() could return 0, but if
errno wasn't changed the following errno==ENOTSOCK could have wrongly
matched.
---

diff --git a/src/lib/connection.c b/src/lib/connection.c
index c532f4ade6..d1c222a487 100644
--- a/src/lib/connection.c
+++ b/src/lib/connection.c
@@ -381,22 +381,27 @@ connection_update_properties(struct connection *conn)
 	int fd = (conn->fd_in < 0 ? conn->fd_out : conn->fd_in);
 	struct net_unix_cred cred;
 
-	if (conn->remote_ip.family != 0)
+	if (conn->remote_ip.family != 0) {
+		/* remote IP was already set */
 		i_assert(conn->remote_port != 0);
-	else if (fd < 0) {
+	} else if (conn->unix_peer_known) {
+		/* already checked */
+	} else if (fd < 0) {
 		/* not connected yet - wait */
-	} else if (conn->fd_in != conn->fd_out || fd < 0 ||
-		 net_getpeername(fd, &conn->remote_ip,
-				 &conn->remote_port) < 0 ||
-		 conn->remote_ip.family == 0) {
-		conn->remote_ip.family = 0;
-		conn->remote_port = 0;
-
-		if (conn->unix_peer_known) {
-			/* already known */
-		} else if (fd < 0 || errno == ENOTSOCK ||
-		      net_getunixcred(fd, &cred) < 0) {
-		} else {
+	} else {
+		if (net_getpeername(fd, &conn->remote_ip,
+				    &conn->remote_port) == 0) {
+			/* either TCP or UNIX socket connection */
+			errno = 0;
+		}
+
+		if (conn->remote_ip.family != 0) {
+			/* TCP connection */
+			i_assert(conn->remote_port != 0);
+		} else if (errno == ENOTSOCK) {
+			/* getpeername() already found out this can't be a UNIX
+			   socket connection */
+		} else if (net_getunixcred(fd, &cred) == 0) {
 			conn->remote_pid = cred.pid;
 			conn->remote_uid = cred.uid;
 		}