In case of modifying an IPv6 packet src/dst address the checksum should be
recalculated only for the last frag. Currently it's done for all frags,
leading to incorrect reassembled packet checksum.
Fix it by adding a new flag to recalculate the checksum only for last frag.
Fixes: bc7a5acdff08 ("datapath: add ipv6 'set' action")
Signed-off-by: Salem Sol <[email protected]>
Acked-by: Mike Pattrick <[email protected]>
---
lib/packets.c | 20 ++++++++++++++++++--
tests/system-traffic.at | 35 +++++++++++++++++++++++++++++++++++
2 files changed, 53 insertions(+), 2 deletions(-)
diff --git a/lib/packets.c b/lib/packets.c
index d0fba8176..b7aef41a5 100644
--- a/lib/packets.c
+++ b/lib/packets.c
@@ -1148,6 +1148,18 @@ packet_set_ipv4_addr(struct dp_packet *packet,
put_16aligned_be32(addr, new_addr);
}
+static bool
+packet_is_last_ipv6_frag(struct dp_packet *packet)
+{
+ const struct ovs_16aligned_ip6_frag *frag_hdr;
+ uint8_t *data = dp_packet_l3(packet);
+
+ data += sizeof (struct ovs_16aligned_ip6_hdr);
+ frag_hdr = ALIGNED_CAST(struct ovs_16aligned_ip6_frag *, data);
+ return (frag_hdr->ip6f_offlg & IP6F_OFF_MASK) &&
+ !(frag_hdr->ip6f_offlg & IP6F_MORE_FRAG);
+}
+
/* Returns true, if packet contains at least one routing header where
* segements_left > 0.
*
@@ -1334,17 +1346,21 @@ packet_set_ipv6(struct dp_packet *packet, const struct
in6_addr *src,
{
struct ovs_16aligned_ip6_hdr *nh = dp_packet_l3(packet);
uint8_t proto = 0;
+ bool recalc_csum;
bool rh_present;
rh_present = packet_rh_present(packet, &proto);
+ recalc_csum = nh->ip6_nxt == IPPROTO_FRAGMENT ?
+ packet_is_last_ipv6_frag(packet) : true;
if (memcmp(&nh->ip6_src, src, sizeof(ovs_be32[4]))) {
- packet_set_ipv6_addr(packet, proto, nh->ip6_src.be32, src, true);
+ packet_set_ipv6_addr(packet, proto, nh->ip6_src.be32,
+ src, recalc_csum);
}
if (memcmp(&nh->ip6_dst, dst, sizeof(ovs_be32[4]))) {
packet_set_ipv6_addr(packet, proto, nh->ip6_dst.be32, dst,
- !rh_present);
+ !rh_present && recalc_csum);
}
packet_set_ipv6_tc(&nh->ip6_flow, key_tc);
diff --git a/tests/system-traffic.at b/tests/system-traffic.at
index 239105e89..16ba42d84 100644
--- a/tests/system-traffic.at
+++ b/tests/system-traffic.at
@@ -192,6 +192,41 @@ NS_CHECK_EXEC([at_ns0], [ping6 -s 3200 -q -c 3 -i 0.3 -w 2
fc00:1::2 | FORMAT_PI
OVS_TRAFFIC_VSWITCHD_STOP
AT_CLEANUP
+AT_SETUP([datapath - ping6 between two ports with header modify])
+OVS_TRAFFIC_VSWITCHD_START()
+
+AT_CHECK([ovs-ofctl add-flow br0 "actions=normal"])
+
+ADD_NAMESPACES(at_ns0, at_ns1)
+
+ADD_VETH(p0, at_ns0, br0, "fc00::1/96", e4:11:22:33:44:55)
+ADD_VETH(p1, at_ns1, br0, "fc00::2/96", e4:11:22:33:44:54)
+NS_CHECK_EXEC([at_ns0], [ip -6 neigh add fc00::3 lladdr e4:11:22:33:44:54 dev
p0])
+NS_CHECK_EXEC([at_ns0], [ip -6 neigh add fc00::2 lladdr e4:11:22:33:44:54 dev
p0])
+NS_CHECK_EXEC([at_ns0], [ip -6 neigh add fc00::1 lladdr e4:11:22:33:44:55 dev
p0])
+
+dnl Linux seems to take a little time to get its IPv6 stack in order. Without
+dnl waiting, we get occasional failures due to the following error:
+dnl "connect: Cannot assign requested address"
+OVS_WAIT_UNTIL([ip netns exec at_ns0 ping6 -c 1 fc00::2])
+
+AT_CHECK([ovs-ofctl del-flows -OOpenFlow15 br0], [], [stdout], [stderr])
+AT_CHECK([ovs-ofctl add-flow -OOpenFlow15 br0
in_port=ovs-p0,ipv6,ipv6_dst=fc00::3,ipv6_src=fc00::1,actions=set_field:fc00::2-\>ipv6_dst,ovs-p1],
[], [stdout], [stderr])
+AT_CHECK([ovs-ofctl add-flow -OOpenFlow15 br0
in_port=ovs-p1,ipv6,ipv6_dst=fc00::1,ipv6_src=fc00::2,actions=set_field:fc00::3-\>ipv6_src,ovs-p0],
[], [stdout], [stderr])
+
+NS_CHECK_EXEC([at_ns0], [ping6 -q -c 3 -i 0.3 -w 2 fc00::3 | FORMAT_PING],
[0], [dnl
+3 packets transmitted, 3 received, 0% packet loss, time 0ms
+])
+NS_CHECK_EXEC([at_ns0], [ping6 -s 1600 -q -c 3 -i 0.3 -w 2 fc00::3 |
FORMAT_PING], [0], [dnl
+3 packets transmitted, 3 received, 0% packet loss, time 0ms
+])
+NS_CHECK_EXEC([at_ns0], [ping6 -s 3200 -q -c 3 -i 0.3 -w 2 fc00::3 |
FORMAT_PING], [0], [dnl
+3 packets transmitted, 3 received, 0% packet loss, time 0ms
+])
+
+OVS_TRAFFIC_VSWITCHD_STOP
+AT_CLEANUP
+
AT_SETUP([datapath - ping over bond])
OVS_TRAFFIC_VSWITCHD_START()
--
2.21.0
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