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authorDmitry Valter <d-valter@yandex-team.ru>2022-12-09 19:34:22 +0000
committerOle Tr�an <otroan@employees.org>2023-02-03 14:31:54 +0000
commit6b97c43005f6458ce2e253f87af6f609eaebef60 (patch)
treef7a7a8f67a4e1e0dd0f158e423dd0c8e6f7559cf /src
parentfc2d95d115ea5e82bc3efb18cf40632449112fdf (diff)
nat: fix accidental o2i deletion/reuse
Nat session is allocated before the port allocation. During port allocation candidate address+port are set to o2i 6-tuple and tested against the flow hash. If insertion fails, the port is busy and rejected. When all N attempts are unsuccessful, "out-of-ports" error is recorded and the session is to be deleted. During session deletion o2i and i2o tuples are deleted from the flow hash. In case of "out-of-ports" i2o tuple is not valid, however o2i is and it refers to **some other** session that's known to be allocated. By backing match tuple up session should be invalidated well enough not to collide with any valid one. Type: fix Signed-off-by: Dmitry Valter <d-valter@yandex-team.ru> Change-Id: Id30be6f26ecce7a5a63135fb971bb65ce318af82
Diffstat (limited to 'src')
-rw-r--r--src/plugins/nat/nat44-ed/nat44_ed_in2out.c6
1 files changed, 6 insertions, 0 deletions
diff --git a/src/plugins/nat/nat44-ed/nat44_ed_in2out.c b/src/plugins/nat/nat44-ed/nat44_ed_in2out.c
index f41fcac5153..deec0099933 100644
--- a/src/plugins/nat/nat44-ed/nat44_ed_in2out.c
+++ b/src/plugins/nat/nat44-ed/nat44_ed_in2out.c
@@ -105,6 +105,9 @@ nat_ed_alloc_addr_and_port_with_snat_address (
const u16 port_thread_offset =
(port_per_thread * snat_thread_index) + ED_USER_PORT_OFFSET;
+ /* Backup original match in case of failure */
+ const nat_6t_t match = s->o2i.match;
+
s->o2i.match.daddr = a->addr;
/* first try port suggested by caller */
u16 port = clib_net_to_host_u16 (*outside_port);
@@ -136,6 +139,9 @@ nat_ed_alloc_addr_and_port_with_snat_address (
--attempts;
}
while (attempts > 0);
+
+ /* Revert match */
+ s->o2i.match = match;
return 1;
}