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authorVladislav Grishenko <themiron@yandex-team.ru>2022-08-19 20:42:22 +0500
committerBeno�t Ganne <bganne@cisco.com>2022-09-15 08:39:19 +0000
commit5f694d1ecfbe2315e9bbcc98a83b83620e6f6b94 (patch)
treeabedb569e9c9155d0d0c957e10f7d0b2e42bfd75 /src/plugins/nat/nat44-ed/nat44_ed_out2in.c
parentb3778cce705305ecc3401b9dd69790b200e82dbe (diff)
nat: fix nat44-ed port range with multiple workers
The number of available dynamic ports is set to (0xffff - 1024) = 64511, which is not divisable by the pow2 number of workers - the only integer divisors are 31 and 2081. So, total dynamic port range of all workers will be less than it: 1 wrk: n = (port_per_thread = 64511/1)*1 = 64511 + 1025 = 65536 2 wrk: n = (port_per_thread = 64511/2)*2 = 64510 + 1025 = 65535 4 wrk: n = (port_per_thread = 64511/4)*4 = 64508 + 1025 = 65533 8 wrk: n = (port_per_thread = 64511/8)*8 = 64504 + 1025 = 65529 ... As seen, with multiple workers there are unused trailing ports for every nat pool address and that is the reason of out-of-bound index in the worker array on out2in path due (port - 1024) / port_per_thread math. This was fixed in 5c9f9968de63fa627b4a72b344df36cdc686d18a, so packets to unused ports will go to existing worker and dropped there. Per RFC 6335 https://www.rfc-editor.org/rfc/rfc6335#section-6: 6. Port Number Ranges o the System Ports, also known as the Well Known Ports, from 0-1023 (assigned by IANA) o the User Ports, also known as the Registered Ports, from 1024- 49151 (assigned by IANA) o the Dynamic Ports, also known as the Private or Ephemeral Ports, from 49152-65535 (never assigned) According that let's allocate dynamic ports from 1024 and have full port range with a wide range of the workers number - 64 integer divisors in total, including pow2 ones: 1 wrk: n = (port_per_thread = 64512/1)*1 = 64512 + 1024 = 65536 2 wrk: n = (port_per_thread = 64512/2)*2 = 64512 + 1024 = 65536 3 wrk: n = (port_per_thread = 64512/3)*3 = 64512 + 1024 = 65536 4 wrk: n = (port_per_thread = 64512/4)*4 = 64512 + 1024 = 65536 5 wrk: n = (port_per_thread = 64512/5)*5 = 64510 + 1024 = 65534 6 wrk: n = (port_per_thread = 64512/6)*6 = 64512 + 1024 = 65536 7 wrk: n = (port_per_thread = 64512/7)*7 = 64512 + 1024 = 65536 8 wrk: n = (port_per_thread = 64512/8)*8 = 64512 + 1024 = 65536 ... Modulo from 5c9f9968de63fa627b4a72b344df36cdc686d18a is still required when the numbers of workers is not the integer divisor of 64512. Type: fix Fixes: 5c9f9968de63fa627b4a72b344df36cdc686d18a Change-Id: I9edaea07e58ff4888812b0d86cbf41a3784b189e Signed-off-by: Vladislav Grishenko <themiron@yandex-team.ru>
Diffstat (limited to 'src/plugins/nat/nat44-ed/nat44_ed_out2in.c')
-rw-r--r--src/plugins/nat/nat44-ed/nat44_ed_out2in.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/src/plugins/nat/nat44-ed/nat44_ed_out2in.c b/src/plugins/nat/nat44-ed/nat44_ed_out2in.c
index 33449122e43..dfe4a15752b 100644
--- a/src/plugins/nat/nat44-ed/nat44_ed_out2in.c
+++ b/src/plugins/nat/nat44-ed/nat44_ed_out2in.c
@@ -279,7 +279,8 @@ nat44_ed_alloc_i2o_port (snat_main_t *sm, snat_address_t *a, snat_session_t *s,
for (int i = 0; i < ED_PORT_ALLOC_ATTEMPTS; ++i)
{
portnum = (sm->port_per_thread * snat_thread_index) +
- snat_random_port (0, sm->port_per_thread - 1) + 1024;
+ snat_random_port (0, sm->port_per_thread - 1) +
+ ED_USER_PORT_OFFSET;
portnum = clib_host_to_net_u16 (portnum);
nat_6t_i2o_flow_init (sm, thread_index, s, i2o_addr, i2o_port, a->addr,
portnum, i2o_fib_index, proto);