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authorHiroki Narukawa <nhirokinet@nhiroki.net>2020-09-04 15:41:40 +0900
committerDamjan Marion <dmarion@me.com>2020-10-24 09:00:56 +0000
commitfa4d4c635b82e31ecf7a52b8c794714f47b298cd (patch)
tree3996153577a792a258299f4c0e33b6ccdf393e8d /src
parent490e077fb9a2295d704db3c1bee5901823d2441b (diff)
lb: Loadbalancer plugin, correctly rewrite checksum in L3DSR, non-TCP cases
Current loadbalancer seems to rewrite the 17th and 18th octet of L4 header regardless of which kind of L4 protocol is used in case of L3DSR. In case UDP, it rewrites 9th and 10th octet of payload (because UDP header is 8 octets long). If UDP payload is less than 8 octets, UDP checksum becomes invalid. In other protocols similar problems is likely to occue. This patch checks which L4 protocol is used, and rewrite packet regarding the L4 protocol. Signed-off-by: Hiroki Narukawa <nhirokinet@nhiroki.net> Change-Id: I84390ff58a33f05efac0421856beea89014adc72 Type: fix
Diffstat (limited to 'src')
-rw-r--r--src/plugins/lb/node.c18
1 files changed, 14 insertions, 4 deletions
diff --git a/src/plugins/lb/node.c b/src/plugins/lb/node.c
index 870201d18eb..b5e9da71376 100644
--- a/src/plugins/lb/node.c
+++ b/src/plugins/lb/node.c
@@ -435,7 +435,6 @@ lb_node_fn (vlib_main_t * vm,
else if (encap_type == LB_ENCAP_TYPE_L3DSR) /* encap L3DSR*/
{
ip4_header_t *ip40;
- tcp_header_t *th0;
ip_csum_t csum;
u32 old_dst, new_dst;
u8 old_tos, new_tos;
@@ -459,9 +458,20 @@ lb_node_fn (vlib_main_t * vm,
ip40->checksum = ip_csum_fold (csum);
/* Recomputing L4 checksum after dst-IP modifying */
- th0 = ip4_next_header (ip40);
- th0->checksum = 0;
- th0->checksum = ip4_tcp_udp_compute_checksum (vm, p0, ip40);
+ if (ip40->protocol == IP_PROTOCOL_TCP)
+ {
+ tcp_header_t *th0;
+ th0 = ip4_next_header (ip40);
+ th0->checksum = 0;
+ th0->checksum = ip4_tcp_udp_compute_checksum (vm, p0, ip40);
+ }
+ else if (ip40->protocol == IP_PROTOCOL_UDP)
+ {
+ udp_header_t *uh0;
+ uh0 = ip4_next_header (ip40);
+ uh0->checksum = 0;
+ uh0->checksum = ip4_tcp_udp_compute_checksum (vm, p0, ip40);
+ }
}
else if ((encap_type == LB_ENCAP_TYPE_NAT4)
|| (encap_type == LB_ENCAP_TYPE_NAT6))