path: root/doc
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authorMichal Kubecek <>2019-07-19 09:31:24 +0200
committerPablo Neira Ayuso <>2019-07-22 22:10:52 +0200
commitee4991ea402ca61a9d1a46c83c4d4219b97d7da0 (patch)
treed0f9c36a729e6a77afd55dd0f61fc4ada9c8f772 /doc
parentb47e00e8a579519b163cb4faed017463bf64c40d (diff)
conntrackd: cthelper: Add new SLP helper
Service Location Protocol (SLP) uses multicast requests for DA (Directory agent) and SA (Service agent) discovery. Replies to these requests are unicast and their source address does not match destination address of the request so that we need a conntrack helper. A kernel helper was submitted back in 2013 but was rejected as userspace helper infrastructure is preferred. This adds an SLP helper to conntrackd. As the function of SLP helper is the same as what existing mDNS helper does, src/helpers/slp.c is essentially just a copy of src/helpers/mdns.c, except for the default timeout and example usage. As with mDNS helper, there is no NAT support for the time being as that would probably require kernel side changes and certainly further study (and could possibly work only for source NAT). Signed-off-by: Michal Kubecek <> Signed-off-by: Pablo Neira Ayuso <>
Diffstat (limited to 'doc')
1 files changed, 8 insertions, 0 deletions
diff --git a/doc/helper/conntrackd.conf b/doc/helper/conntrackd.conf
index 4148544..6ffe008 100644
--- a/doc/helper/conntrackd.conf
+++ b/doc/helper/conntrackd.conf
@@ -96,6 +96,14 @@ Helper {
ExpectTimeout 300
+ Type slp inet udp {
+ QueueNum 7
+ QueueLen 10240
+ Policy slp {
+ ExpectMax 8
+ ExpectTimeout 16
+ }
+ }