diff options
| author |   Elias Rudberg <elias.rudberg@bahnhof.net> | 2020-12-04 19:32:55 +0100 |
|---|---|---|
| committer |   Ole Tr�an <otroan@employees.org> | 2020-12-08 08:49:24 +0000 |
| commit | 9b8cb5082471dd670066b8ba2872ffbcc35a87f8 (patch) | |
| tree | 7345bf7e7c5c86cfe7f87ff45bb4c94c42ceacc6 /src/plugins/nat/nat44_hairpinning.c | |
| parent | 3227e49689974e2dd3aea4d85debdf159d532b42 (diff) | |
nat: avoid hairpinning infinite loop problem
Fix in nat44 hairpinning code to check if anything was actually
changed in the snat_hairpinning() routine, and return 0 if nothing
changed. This helps avoid an infinite loop repeating the three
nodes nat44-hairpinning-->ip4-lookup-->ip4-local in case there
was no change. Also add a corresponding test case.
Type: fix
Signed-off-by: Elias Rudberg <elias.rudberg@bahnhof.net>
Change-Id: I95f48476bd002ac4c6789afe504681f1963e5d38
Signed-off-by: Elias Rudberg <elias.rudberg@bahnhof.net>
Diffstat (limited to 'src/plugins/nat/nat44_hairpinning.c')
| -rw-r--r-- | src/plugins/nat/nat44_hairpinning.c | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/src/plugins/nat/nat44_hairpinning.c b/src/plugins/nat/nat44_hairpinning.c index 9eadcf30832..2859046ae05 100644 --- a/src/plugins/nat/nat44_hairpinning.c +++ b/src/plugins/nat/nat44_hairpinning.c @@ -108,6 +108,7 @@ snat_hairpinning (vlib_main_t * vm, vlib_node_runtime_t * node, ip4_address_t sm0_addr; u16 sm0_port; u32 sm0_fib_index; + u32 old_sw_if_index = vnet_buffer (b0)->sw_if_index[VLIB_TX]; /* Check if destination is static mappings */ if (!snat_static_mapping_match (sm, ip0->dst_address, udp0->dst_port, sm->outside_fib_index, proto0, @@ -159,6 +160,17 @@ snat_hairpinning (vlib_main_t * vm, vlib_node_runtime_t * node, vnet_buffer (b0)->sw_if_index[VLIB_TX] = s0->in2out.fib_index; } + /* Check if anything has changed and if not, then return 0. This + helps avoid infinite loop, repeating the three nodes + nat44-hairpinning-->ip4-lookup-->ip4-local, in case nothing has + changed. */ + old_dst_addr0 = ip0->dst_address.as_u32; + old_dst_port0 = tcp0->dst; + if (new_dst_addr0 == old_dst_addr0 + && new_dst_port0 == old_dst_port0 + && vnet_buffer (b0)->sw_if_index[VLIB_TX] == old_sw_if_index) + return 0; + /* Destination is behind the same NAT, use internal address and port */ if (new_dst_addr0) { |