Thanks for reviewing. For these two packets:
dnl outer IP: Source: 172.16.180.105 Destination: 172.16.180.106 This one is normal BFD packet, bfd_should_process_flow should return true, as used to. dnl inner IP: Source: 192.168.10.104 Destination: 192.168.10.105 This one is overlay BFD packet, bfd_should_process_flow should return false so this packet won't be intercepted by OVS's BFD engine. Thanks, Yifeng On Wed, Jul 22, 2020 at 10:54 AM William Tu <u9012...@gmail.com> wrote: > On Wed, Jul 22, 2020 at 01:59:04AM -0700, Yifeng Sun wrote: > > Current OVS intercepts and processes all BFD packets, thus VM-2-VM > > BFD packets get lost and the recipient VM never sees them. > > > > This patch fixes it by only intercepting and processing BFD packets > > destined to a configured BFD instance, and other BFD packets are made > > available to the OVS flow table for forwarding. > > > > This patch adds new test to validate BFD overlay. > > > > This patch keeps BFD's backward compatibility. > > > > Signed-off-by: Yifeng Sun <pkusunyif...@gmail.com> > > --- > > v1->v2: Add test by William's suggestion. > > > > lib/bfd.c | 16 +++++++++++++--- > > tests/system-traffic.at | 42 ++++++++++++++++++++++++++++++++++++++++++ > > vswitchd/vswitch.xml | 7 +++++++ > > 3 files changed, 62 insertions(+), 3 deletions(-) > > > > diff --git a/lib/bfd.c b/lib/bfd.c > > index cc8c6857afa4..3c965699ace3 100644 > > --- a/lib/bfd.c > > +++ b/lib/bfd.c > > @@ -149,6 +149,9 @@ BUILD_ASSERT_DECL(BFD_PACKET_LEN == sizeof(struct > msg)); > > #define FLAGS_MASK 0x3f > > #define DEFAULT_MULT 3 > > > > +#define BFD_DEFAULT_SRC_IP 0xA9FE0101 /* 169.254.1.1 */ > > +#define BFD_DEFAULT_DST_IP 0xA9FE0100 /* 169.254.1.0 */ > > + > > struct bfd { > > struct hmap_node node; /* In 'all_bfds'. */ > > uint32_t disc; /* bfd.LocalDiscr. Key in 'all_bfds' > hmap. */ > > @@ -457,9 +460,9 @@ bfd_configure(struct bfd *bfd, const char *name, > const struct smap *cfg, > > &bfd->rmt_eth_dst); > > > > bfd_lookup_ip(smap_get_def(cfg, "bfd_src_ip", ""), > > - htonl(0xA9FE0101) /* 169.254.1.1 */, &bfd->ip_src); > > + htonl(BFD_DEFAULT_SRC_IP), &bfd->ip_src); > > bfd_lookup_ip(smap_get_def(cfg, "bfd_dst_ip", ""), > > - htonl(0xA9FE0100) /* 169.254.1.0 */, &bfd->ip_dst); > > + htonl(BFD_DEFAULT_DST_IP), &bfd->ip_dst); > > > > forwarding_if_rx = smap_get_bool(cfg, "forwarding_if_rx", false); > > if (bfd->forwarding_if_rx != forwarding_if_rx) { > > @@ -674,7 +677,14 @@ bfd_should_process_flow(const struct bfd *bfd_, > const struct flow *flow, > > memset(&wc->masks.nw_proto, 0xff, sizeof wc->masks.nw_proto); > > if (flow->nw_proto == IPPROTO_UDP > > && !(flow->nw_frag & FLOW_NW_FRAG_LATER) > > - && tp_dst_equals(flow, BFD_DEST_PORT, wc)) { > > + && tp_dst_equals(flow, BFD_DEST_PORT, wc) > > + && (bfd->ip_src == htonl(BFD_DEFAULT_SRC_IP) > > + || bfd->ip_src == flow->nw_dst)) { > > + > > + if (bfd->ip_src == flow->nw_dst) { > > + memset(&wc->masks.nw_dst, 0xffffffff, sizeof > wc->masks.nw_dst); > > + } > > + > > bool check_tnl_key; > > > > atomic_read_relaxed(&bfd->check_tnl_key, &check_tnl_key); > > diff --git a/tests/system-traffic.at b/tests/system-traffic.at > > index 2a0fbadff4a1..80b58996d530 100644 > > --- a/tests/system-traffic.at > > +++ b/tests/system-traffic.at > > @@ -6289,3 +6289,45 @@ OVS_WAIT_UNTIL([cat p2.pcap | egrep "0x0050: > *0000 *0000 *5002 *2000 *b85e *0000 > > > > OVS_TRAFFIC_VSWITCHD_STOP > > AT_CLEANUP > > + > > +AT_SETUP([bfd - BFD overlay]) > > +OVS_CHECK_GENEVE() > > + > > +OVS_TRAFFIC_VSWITCHD_START() > > + > > +AT_CHECK([ovs-vsctl -- set bridge br0 > other-config:hwaddr=\"f2:ff:00:00:00:01\"]) > > +ADD_BR([br-underlay], [set bridge br-underlay > other-config:hwaddr=\"ee:09:e0:4d:bf:31\"]) > > + > > +AT_CHECK([ovs-ofctl add-flow br0 "actions=normal"]) > > +AT_CHECK([ovs-ofctl add-flow br-underlay "actions=normal"]) > > + > > +ADD_NAMESPACES(at_ns0) > > + > > +dnl Set up underlay link from host into the namespace using veth pair. > > +ADD_VETH(p0, at_ns0, br-underlay, "172.16.180.105/24", > 4e:12:5d:6c:74:3d) > > +AT_CHECK([ip addr add dev br-underlay "172.16.180.106/24"]) > > +AT_CHECK([ip link set dev br-underlay up]) > > + > > +dnl Set up tunnel endpoints on OVS outside the namespace. > > +ADD_OVS_TUNNEL([geneve], [br0], [at_gnv0], [172.16.180.105], [ > 192.168.10.100/24], > > + [options:packet_type=ptap]) > > + > > +dnl Certain Linux distributions, like CentOS, have default iptable rules > > +dnl to reject input traffic from br-underlay. Here we add a rule to walk > > +dnl around it. > > +iptables -I INPUT 1 -i br-underlay -j ACCEPT > > +on_exit 'iptables -D INPUT 1' > > + > > +dnl Firstly, test normal BFD packet. > > +ovs-ofctl -O OpenFlow13 packet-out br-underlay "in_port=1 > packet=ee09e04dbf314e125d6c743d080045c0006624d94000401153f9ac10b469ac10b46a739f17c1005247f900806558000000000023200000016a0f5a9ed376080045c0003400000000ff11fa03ac10b469ac10b46ac0070ec80020000021c003187b3c96ebbc96b962000186a0000f424000000000 > actions=NORMAL" > The packet above is > dnl outer IP: Source: 172.16.180.105 Destination: 172.16.180.106 > dnl inner IP: Source: 172.16.180.105 Destination: 172.16.180.106 > > And why does this trigger ovs to process it ex: bfd_should_process_flow() > return true? > In your patch, you're adding extra check > bfd->ip_src == flow->nw_dst > and here > bfd->ip_src is default 169.254.1.1 > flow->nw_dst is 172.16.180.106 > > > > +dnl Next we test overlay BFD packet. > > +ovs-ofctl -O OpenFlow13 packet-out br-underlay "in_port=1 > packet=ee09e04dbf314e125d6c743d08004500005b2558400040115445ac10b469ac10b46a6b1017c1004722c1024065580000000001048001001803005254009d0b6d5254000c89840800450000210e22400040119688c0a80a68c0a80a6995cd0ec8000dd342746573740a > actions=NORMAL" > > The packet above is > dnl outer IP: Source: 172.16.180.105 Destination: 172.16.180.106 > dnl inner IP: Source: 192.168.10.104 Destination: 192.168.10.105 > So the bfd_should_process_flow returns false. > > > + > > +ovs-dpctl dump-flows > datapath-flows.txt > > +dnl BFD packet was handled by BFD flow. > > +AT_FAIL_IF([cat datapath-flows.txt | egrep > "tunnel\(.*,src=172.16.180.105,dst=172.16.180.106,.*,eth\(\),eth_type\(0x0800\),ipv4\(proto=17,.*\),udp\(dst=3784\), > .*, actions:userspace\(pid=.*,slow_path\(bfd\)\)" 2>&1 1>/dev/null]) > > +dnl Overlay BFD packet was handled by non-BFD flows. > > +AT_FAIL_IF([cat datapath-flows.txt | egrep > "tunnel\(.*,src=172.16.180.105,dst=172.16.180.106,.*,eth\(.*\),eth_type\(0x0800\),ipv4\(src=192.168.10.104,dst=192.168.10.105,proto=17,.*\),udp\(.*,dst=3784\), > .*, actions:drop" 2>&1 1>/dev/null]) > > + > > +OVS_TRAFFIC_VSWITCHD_STOP > > +AT_CLEANUP > > _______________________________________________ dev mailing list d...@openvswitch.org https://mail.openvswitch.org/mailman/listinfo/ovs-dev