lib: Test return of fcntl in agentx.c

The agentx.c code was calling fcntl but not testing return
code and handling it, thus making SA unhappy.

Fix.

Signed-off-by: Donald Sharp <sharpd@cumulusnetworks.com>

1 files changed, 19 insertions, 5 deletions

diff --git a/lib/agentx.c b/lib/agentx.c
index 2c6a43d1a7..b479b5ea4c 100644
--- a/lib/agentx.c
+++ b/lib/agentx.c
@@ -55,28 +55,42 @@ static int agentx_timeout(struct thread *t)
 static int agentx_read(struct thread *t)
 {
 	fd_set fds;
-	int flags;
+	int flags, new_flags = 0;
 	int nonblock = false;
 	struct listnode *ln = THREAD_ARG(t);
 	list_delete_node(events, ln);
 
 	/* fix for non blocking socket */
 	flags = fcntl(THREAD_FD(t), F_GETFL, 0);
-	if (-1 == flags)
+	if (-1 == flags) {
+		flog_err(EC_LIB_SYSTEM_CALL, "Failed to get FD settings fcntl: %s(%d)",
+			 strerror(errno), errno);
 		return -1;
+	}
 
 	if (flags & O_NONBLOCK)
 		nonblock = true;
 	else
-		fcntl(THREAD_FD(t), F_SETFL, flags | O_NONBLOCK);
+		new_flags = fcntl(THREAD_FD(t), F_SETFL, flags | O_NONBLOCK);
+
+	if (new_flags == -1)
+		flog_err(EC_LIB_SYSTEM_CALL, "Failed to set snmp fd non blocking: %s(%d)",
+			 strerror(errno), errno);
 
 	FD_ZERO(&fds);
 	FD_SET(THREAD_FD(t), &fds);
 	snmp_read(&fds);
 
 	/* Reset the flag */
-	if (!nonblock)
-		fcntl(THREAD_FD(t), F_SETFL, flags);
+	if (!nonblock) {
+		new_flags = fcntl(THREAD_FD(t), F_SETFL, flags);
+
+		if (new_flags == -1)
+			flog_err(
+				EC_LIB_SYSTEM_CALL,
+				"Failed to set snmp fd back to original settings: %s(%d)",
+				strerror(errno), errno);
+	}
 
 	netsnmp_check_outstanding_agent_requests();
 	agentx_events_update();