From 706cc465d9efc92ecd35f6716af9dfed9812dd35 Mon Sep 17 00:00:00 2001
From: Mike Brady <4265913+mikebrady@users.noreply.github.com>
Date: Thu, 8 Jul 2021 20:37:40 +0000
Subject: [PATCH] Check return status from getifaddrs.

---
 nqptp-clock-sources.c | 49 ++++++++++++++++++++++++-------------------
 1 file changed, 27 insertions(+), 22 deletions(-)

diff --git a/nqptp-clock-sources.c b/nqptp-clock-sources.c
index a3ca06f..8e4aa13 100644
--- a/nqptp-clock-sources.c
+++ b/nqptp-clock-sources.c
@@ -25,6 +25,7 @@
 #include <ifaddrs.h>
 #include <string.h>
 #include <sys/types.h>
+#include <errno.h>
 
 #ifdef CONFIG_FOR_FREEBSD
 #include <sys/socket.h>
@@ -125,34 +126,38 @@ void update_clock_self_identifications(clock_source_private_data *clocks_private
   struct ifaddrs *ifap, *ifa;
   void *addr = NULL;
   short family;
-  getifaddrs(&ifap);
-  for (ifa = ifap; ifa; ifa = ifa->ifa_next) {
-    family = ifa->ifa_addr->sa_family;
+  int response = getifaddrs(&ifap);
+  if (response == 0) {
+    for (ifa = ifap; ifa; ifa = ifa->ifa_next) {
+      family = ifa->ifa_addr->sa_family;
 #ifdef AF_INET6
-    if (ifa->ifa_addr && family == AF_INET6) {
-      struct sockaddr_in6 *sa6 = (struct sockaddr_in6 *)ifa->ifa_addr;
-      addr = &(sa6->sin6_addr);
-    }
+      if (ifa->ifa_addr && family == AF_INET6) {
+        struct sockaddr_in6 *sa6 = (struct sockaddr_in6 *)ifa->ifa_addr;
+        addr = &(sa6->sin6_addr);
+      }
 #endif
-    if (ifa->ifa_addr && family == AF_INET) {
-      struct sockaddr_in *sa4 = (struct sockaddr_in *)ifa->ifa_addr;
-      addr = &(sa4->sin_addr);
-    }
-    char ip_string[64];
-    memset(ip_string, 0, sizeof(ip_string));
-    if (addr != NULL)
-      inet_ntop(family, addr, ip_string, sizeof(ip_string));
-    if (strlen(ip_string) != 0) {
-      // now set the is_one_of_ours flag of any clock with this ip
-      for (i = 0; i < MAX_CLOCKS; i++) {
-        if (strcasecmp(ip_string, clocks_private_info[i].ip) == 0) {
-          debug(2, "found an entry for one of our clocks");
-          clocks_private_info[i].is_one_of_ours = 1;
+      if (ifa->ifa_addr && family == AF_INET) {
+        struct sockaddr_in *sa4 = (struct sockaddr_in *)ifa->ifa_addr;
+        addr = &(sa4->sin_addr);
+      }
+      char ip_string[64];
+      memset(ip_string, 0, sizeof(ip_string));
+      if (addr != NULL)
+        inet_ntop(family, addr, ip_string, sizeof(ip_string));
+      if (strlen(ip_string) != 0) {
+        // now set the is_one_of_ours flag of any clock with this ip
+        for (i = 0; i < MAX_CLOCKS; i++) {
+          if (strcasecmp(ip_string, clocks_private_info[i].ip) == 0) {
+            debug(2, "found an entry for one of our clocks");
+            clocks_private_info[i].is_one_of_ours = 1;
+          }
         }
       }
     }
+    freeifaddrs(ifap);
+  } else {
+    debug(1,"getifaddrs error - %s.", strerror(errno));
   }
-  freeifaddrs(ifap);
 }
 
 void debug_log_nqptp_status(int level) {
-- 
2.47.2