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L3DSR fix ip checksum issue and add test

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Change-Id: Iedebbac71d3e694b915d6a126c80ecc3b5473a4a
Signed-off-by: Hongjun Ni <hongjun.ni@intel.com>
This commit is contained in:
Hongjun Ni
2018-06-08 07:12:05 +08:00
committed by Dave Barach
parent 8d2e9bd8d8
commit 6fb0d9b269
2 changed files with 18 additions and 9 deletions
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21
src/plugins/lb/node.c
View File

@ -387,22 +387,25 @@ lb_node_fn (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * frame,
ip4_header_t *ip40;
tcp_header_t *th0;
ip_csum_t csum;
u32 old_dst;
u32 old_dscp;
u32 old_dst, new_dst;
u8 old_tos, new_tos;
ip40 = vlib_buffer_get_current (p0);
old_dst = ip40->dst_address.as_u32;
old_dscp = ip40->tos;
ip40->dst_address = lbm->ass[asindex0].address.ip4;
new_dst = lbm->ass[asindex0].address.ip4.as_u32;
ip40->dst_address.as_u32 = lbm->ass[asindex0].address.ip4.as_u32;
/* Get and rewrite DSCP bit */
old_tos = ip40->tos;
new_tos = (u8) ((vip0->encap_args.dscp & 0x3F) << 2);
ip40->tos = (u8) ((vip0->encap_args.dscp & 0x3F) << 2);
csum = ip40->checksum;
csum = ip_csum_sub_even (csum, old_dst);
csum = ip_csum_sub_even (csum, old_dscp);
csum = ip_csum_add_even (csum,
lbm->ass[asindex0].address.ip4.as_u32);
csum = ip_csum_add_even (csum, ip40->tos);
csum = ip_csum_update (csum, old_tos, new_tos,
ip4_header_t,
tos /* changed member */);
csum = ip_csum_update (csum, old_dst, new_dst,
ip4_header_t,
dst_address /* changed member */);
ip40->checksum = ip_csum_fold (csum);
/* Recomputing L4 checksum after dst-IP modifying */

6
test/test_lb.py
View File

@ -4,6 +4,7 @@ from scapy.layers.inet import IP, UDP
from scapy.layers.inet6 import IPv6
from scapy.layers.l2 import Ether, GRE
from scapy.packet import Raw
from scapy.data import IP_PROTOS
from framework import VppTestCase
from util import ppp
@ -145,6 +146,11 @@ class TestLB(VppTestCase):
self.assertEqual(ip.dst, "10.0.0.%u" % asid)
self.assertEqual(ip.tos, 0x1c)
self.assertEqual(len(ip.options), 0)
self.assert_ip_checksum_valid(p)
if ip.proto == IP_PROTOS.tcp:
self.assert_tcp_checksum_valid(p)
elif ip.proto == IP_PROTOS.udp:
self.assert_udp_checksum_valid(p)
elif (encap == 'nat4'):
ip = p[IP]
asid = int(ip.dst.split(".")[3])