From e73b6b7bacb635814b6e47c63e49c60cc5a13bf1 Mon Sep 17 00:00:00 2001 From: Andreas Schultz Date: Tue, 17 Jul 2018 11:43:23 +0200 Subject: Fix IPv6 csum calculation in GTP-U encapsulation The length field is included in the checksum. Therefor, we need to update it before calculating the checksum. Change-Id: Id23234efb80ea3747a0f8a5c7bf8621748d27635 Signed-off-by: Andreas Schultz --- src/plugins/gtpu/gtpu_encap.c | 49 ++++++++++++++++++++++--------------------- 1 file changed, 25 insertions(+), 24 deletions(-) diff --git a/src/plugins/gtpu/gtpu_encap.c b/src/plugins/gtpu/gtpu_encap.c index 4442c42ad66..5f52d5a1543 100644 --- a/src/plugins/gtpu/gtpu_encap.c +++ b/src/plugins/gtpu/gtpu_encap.c @@ -380,24 +380,6 @@ gtpu_encap_inline (vlib_main_t * vm, udp3->length = new_l3; udp3->src_port = flow_hash3; - /* IPv6 UDP checksum is mandatory */ - udp0->checksum = ip6_tcp_udp_icmp_compute_checksum(vm, b0, - ip6_0, &bogus); - if (udp0->checksum == 0) - udp0->checksum = 0xffff; - udp1->checksum = ip6_tcp_udp_icmp_compute_checksum(vm, b1, - ip6_1, &bogus); - if (udp1->checksum == 0) - udp1->checksum = 0xffff; - udp2->checksum = ip6_tcp_udp_icmp_compute_checksum(vm, b2, - ip6_2, &bogus); - if (udp2->checksum == 0) - udp2->checksum = 0xffff; - udp3->checksum = ip6_tcp_udp_icmp_compute_checksum(vm, b3, - ip6_3, &bogus); - if (udp3->checksum == 0) - udp3->checksum = 0xffff; - /* Fix GTPU length */ gtpu0 = (gtpu_header_t *)(udp0+1); new_l0 = clib_host_to_net_u16 (vlib_buffer_length_in_chain(vm, b0) @@ -419,6 +401,25 @@ gtpu_encap_inline (vlib_main_t * vm, - sizeof (*ip6_3) - sizeof(*udp3) - GTPU_V1_HDR_LEN); gtpu3->length = new_l3; + + /* IPv6 UDP checksum is mandatory */ + udp0->checksum = ip6_tcp_udp_icmp_compute_checksum(vm, b0, + ip6_0, &bogus); + if (udp0->checksum == 0) + udp0->checksum = 0xffff; + udp1->checksum = ip6_tcp_udp_icmp_compute_checksum(vm, b1, + ip6_1, &bogus); + if (udp1->checksum == 0) + udp1->checksum = 0xffff; + udp2->checksum = ip6_tcp_udp_icmp_compute_checksum(vm, b2, + ip6_2, &bogus); + if (udp2->checksum == 0) + udp2->checksum = 0xffff; + udp3->checksum = ip6_tcp_udp_icmp_compute_checksum(vm, b3, + ip6_3, &bogus); + if (udp3->checksum == 0) + udp3->checksum = 0xffff; + } pkts_encapsulated += 4; @@ -592,18 +593,18 @@ gtpu_encap_inline (vlib_main_t * vm, udp0->length = new_l0; udp0->src_port = flow_hash0; - /* IPv6 UDP checksum is mandatory */ - udp0->checksum = ip6_tcp_udp_icmp_compute_checksum(vm, b0, - ip6_0, &bogus); - if (udp0->checksum == 0) - udp0->checksum = 0xffff; - /* Fix GTPU length */ gtpu0 = (gtpu_header_t *)(udp0+1); new_l0 = clib_host_to_net_u16 (vlib_buffer_length_in_chain(vm, b0) - sizeof (*ip4_0) - sizeof(*udp0) - GTPU_V1_HDR_LEN); gtpu0->length = new_l0; + + /* IPv6 UDP checksum is mandatory */ + udp0->checksum = ip6_tcp_udp_icmp_compute_checksum(vm, b0, + ip6_0, &bogus); + if (udp0->checksum == 0) + udp0->checksum = 0xffff; } pkts_encapsulated ++; -- cgit 1.2.3-korg