A UDP pseudo-connection between port A in the init namespace and port B in
the pasta guest namespace involves two sockets: udp_splice_init[v6][B]
and udp_splice_ns[v6][A]. The socket which originated this "connection"
will be permanent but the other one will be closed on a timeout.
When we get a packet from the originating socket, we update the timeout on
the other socket, but we don't do the same when we get a reply packet from
the other socket. However any activity on the "connection" probably
indicates that it's still in use. Without this we could incorrectly time
out a "connection" if it's using a protocol which involves a single
initiating packet, but which then gets continuing replies from the target.
Correct this by updating the timeout on both sockets for a packet in either
direction. This also updates the timestamps for the permanent originating
sockets which is unnecessary, but harmless.
Signed-off-by: David Gibson <david(a)gibson.dropbear.id.au>
---
udp.c | 19 +++++++++++++++++--
1 file changed, 17 insertions(+), 2 deletions(-)
diff --git a/udp.c b/udp.c
index 14e8ff2..206e9d3 100644
--- a/udp.c
+++ b/udp.c
@@ -55,12 +55,15 @@
* - bind in namespace to 127.0.0.1:5000
* - add to epoll with reference: index = 5000, splice = 1, orig = 0,
* ns = 1
- * - update udp_splice_ns[V4][5000].ts with current time
+ * - update udp_splice_init[V4][80].ts and udp_splice_ns[V4][5000].ts with
+ * current time
*
* - reverse direction: 127.0.0.1:80 -> 127.0.0.1:5000 in namespace socket s,
* having epoll reference: index = 5000, splice = 1, orig = 0, ns = 1
* - if udp_splice_init[V4][80].sock:
* - send to udp_splice_init[V4][80].sock, with destination port 5000
+ * - update udp_splice_init[V4][80].ts and udp_splice_ns[V4][5000].ts with
+ * current time
* - otherwise, discard
*
* - from namespace to init:
@@ -75,12 +78,15 @@
* - bind in init to 127.0.0.1:2000
* - add to epoll with reference: index = 2000, splice = 1, orig = 0,
* ns = 0
- * - update udp_splice_init[V4][2000].ts with current time
+ * - update udp_splice_ns[V4][22].ts and udp_splice_init[V4][2000].ts with
+ * current time
*
* - reverse direction: 127.0.0.1:22 -> 127.0.0.1:2000 in init from socket s,
* having epoll reference: index = 2000, splice = 1, orig = 0, ns = 0
* - if udp_splice_ns[V4][22].sock:
* - send to udp_splice_ns[V4][22].sock, with destination port 2000
+ * - update udp_splice_ns[V4][22].ts and udp_splice_init[V4][2000].ts with
+ * current time
* - otherwise, discard
*/
@@ -540,12 +546,16 @@ static void udp_sock_handler_splice(const struct ctx *c, union
epoll_ref ref,
return;
}
+ udp_splice_init[v6][dst].ts = now->tv_sec;
udp_splice_ns[v6][src].ts = now->tv_sec;
} else if (!ref.r.p.udp.udp.orig && ref.r.p.udp.udp.ns) {
src += c->udp.fwd_in.rdelta[src];
if (!(s = udp_splice_init[v6][src].sock))
return;
+
+ udp_splice_ns[v6][dst].ts = now->tv_sec;
+ udp_splice_init[v6][src].ts = now->tv_sec;
} else if (ref.r.p.udp.udp.orig && ref.r.p.udp.udp.ns) {
src += c->udp.fwd_in.rdelta[src];
@@ -554,12 +564,17 @@ static void udp_sock_handler_splice(const struct ctx *c, union
epoll_ref ref,
if (s < 0)
return;
}
+
+ udp_splice_ns[v6][dst].ts = now->tv_sec;
udp_splice_init[v6][src].ts = now->tv_sec;
} else if (!ref.r.p.udp.udp.orig && !ref.r.p.udp.udp.ns) {
src += c->udp.fwd_out.rdelta[src];
if (!(s = udp_splice_ns[v6][src].sock))
return;
+
+ udp_splice_init[v6][dst].ts = now->tv_sec;
+ udp_splice_ns[v6][src].ts = now->tv_sec;
} else {
return;
}
--
2.38.1