diff options
| -rw-r--r-- | src/nlmsg.c | 17 |
1 files changed, 13 insertions, 4 deletions
diff --git a/src/nlmsg.c b/src/nlmsg.c index 146296a..9b2f457 100644 --- a/src/nlmsg.c +++ b/src/nlmsg.c @@ -199,11 +199,15 @@ void *mnl_nlmsg_get_payload_tail(const struct nlmsghdr *nlh) * This functions returns 1 if the sequence tracking is fulfilled, otherwise * 0 is returned. We skip the tracking for netlink messages whose sequence * number is zero since it is usually reserved for event-based kernel - * notifications. + * notifications. On the other hand, if seq is set but the message sequence + * number is not set (i.e. this is an event message coming from kernel-space), + * then we also skip the tracking. This approach is good if we use the same + * socket to send commands to kernel-space (that we want to track) and to + * listen to events (that we do not track). */ int mnl_nlmsg_seq_ok(const struct nlmsghdr *nlh, unsigned int seq) { - return nlh->nlmsg_seq ? nlh->nlmsg_seq == seq : 1; + return nlh->nlmsg_seq && seq ? nlh->nlmsg_seq == seq : 1; } /** @@ -213,11 +217,16 @@ int mnl_nlmsg_seq_ok(const struct nlmsghdr *nlh, unsigned int seq) * * This functions return 1 if the origin is fulfilled, otherwise * 0 is returned. We skip the tracking for netlink message whose portID - * is zero since it is reserved for event-based kernel notifications. + * is zero since it is reserved for event-based kernel notifications. On the + * other hand, if portid is set but the message PortID is not set (i.e. this + * is an event message coming from kernel-space), then we also skip the + * tracking. This approach is good if we use the same socket to send commands + * to kernel-space (that we want to track) and to listen to events (that we + * do not track). */ int mnl_nlmsg_portid_ok(const struct nlmsghdr *nlh, unsigned int portid) { - return nlh->nlmsg_pid ? nlh->nlmsg_pid == portid : 1; + return nlh->nlmsg_pid && portid ? nlh->nlmsg_pid == portid : 1; } /** |