src: netlink: Remove variable nf_mon_sock.

Remove variable nf_mon_sock of type structure mnl_socket to avoid
duplicity. Instead variable nf_sock of the same type is passed as
argument to netlink_monitor(). Also remove netlink_open_mon_sock()
function definition, which is no longer required.

Suggested-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Varsha Rao <rvarsha016@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

1 files changed, 23 insertions, 12 deletions

diff --git a/src/mnl.c b/src/mnl.c
index cf060a40..76393123 100644
--- a/src/mnl.c
+++ b/src/mnl.c
@@ -1114,30 +1114,41 @@ int mnl_nft_event_listener(struct mnl_socket *nf_sock,
  	 * message loss due to ENOBUFS.
 	 */
 	unsigned int bufsiz = NFTABLES_NLEVENT_BUFSIZ;
+	int fd = mnl_socket_get_fd(nf_sock);
 	char buf[NFT_NLMSG_MAXSIZE];
+	fd_set readfds;
 	int ret;
 
-	ret = setsockopt(mnl_socket_get_fd(nf_sock), SOL_SOCKET, SO_RCVBUFFORCE,
-			 &bufsiz, sizeof(socklen_t));
-        if (ret < 0) {
+	ret = setsockopt(fd, SOL_SOCKET, SO_RCVBUFFORCE, &bufsiz,
+			 sizeof(socklen_t));
+	if (ret < 0) {
 		/* If this doesn't work, try to reach the system wide maximum
 		 * (or whatever the user requested).
 		 */
-                ret = setsockopt(mnl_socket_get_fd(nf_sock), SOL_SOCKET,
-				 SO_RCVBUF, &bufsiz, sizeof(socklen_t));
+		ret = setsockopt(fd, SOL_SOCKET, SO_RCVBUF, &bufsiz,
+				 sizeof(socklen_t));
 		printf("# Cannot set up netlink socket buffer size to %u bytes, falling back to %u bytes\n",
 		       NFTABLES_NLEVENT_BUFSIZ, bufsiz);
 	}
 
 	while (1) {
-		ret = mnl_socket_recvfrom(nf_sock, buf, sizeof(buf));
-		if (ret < 0) {
-			if (errno == ENOBUFS) {
-				printf("# ERROR: We lost some netlink events!\n");
-				continue;
+		FD_ZERO(&readfds);
+		FD_SET(fd, &readfds);
+
+		ret = select(fd + 1, &readfds, NULL, NULL, NULL);
+		if (ret < 0)
+			return -1;
+
+		if (FD_ISSET(fd, &readfds)) {
+			ret = mnl_socket_recvfrom(nf_sock, buf, sizeof(buf));
+			if (ret < 0) {
+				if (errno == ENOBUFS) {
+					printf("# ERROR: We lost some netlink events!\n");
+					continue;
+				}
+				fprintf(stdout, "# ERROR: %s\n", strerror(errno));
+				break;
 			}
-			fprintf(stdout, "# ERROR: %s\n", strerror(errno));
-			break;
 		}
 
 #ifdef DEBUG