check portid of received messages in examples

netlink is not connection-oriented, we have to check the origin
of the message.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

1 files changed, 4 insertions, 0 deletions

diff --git a/examples/rtnl-link-dump.c b/examples/rtnl-link-dump.c
index 7cf061d..cc3fdf7 100644
--- a/examples/rtnl-link-dump.c
+++ b/examples/rtnl-link-dump.c
@@ -14,6 +14,10 @@ static int data_cb(const struct nlmsghdr *nlh, void *data)
 	int len = mnl_nlmsg_get_len(nlh);
 	struct nlattr *attr;
 
+	/* this does not come from the kernel. */
+	if (nlh->nlmsg_pid != 0)
+		return MNL_CB_OK;
+
 	printf("index=%d type=%d flags=%d family=%d ", 
 		ifm->ifi_index, ifm->ifi_type,
 		ifm->ifi_flags, ifm->ifi_family);