From 71d2595a8f045a7b7bc51e4a9472d5eb540fe079 Mon Sep 17 00:00:00 2001 From: David Gibson Date: Wed, 30 Nov 2022 15:13:10 +1100 Subject: [PATCH] udp: Update UDP "connection" timestamps in both directions 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 Signed-off-by: Stefano Brivio --- udp.c | 19 +++++++++++++++++-- 1 file changed, 17 insertions(+), 2 deletions(-) diff --git a/udp.c b/udp.c index 97453e7..d835a89 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 */ @@ -539,12 +545,16 @@ 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]; @@ -553,12 +563,17 @@ 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; }