On Fri, Feb 3, 2023 at 11:37 AM Dumitru Ceara <[email protected]> wrote:
> On 1/27/23 14:52, Ales Musil wrote: > > The inner header was not handled properly. > > Simplify the code which allows proper handling > > of the inner headers. > > > > Reported-at: https://bugzilla.redhat.com/2137754 > > Signed-off-by: Ales Musil <[email protected]> > > --- > > Hi, Ales, > > The changes look mostly good to me. I only have a few (minor) comments > below. > Hi Dumitru, thank you for the review. Everything should be addressed in v5. > > > v4: Rebase on top of current master. > > Use output of ovs-pcap in tests rather then tcpdump. > > v3: Rebase on top of current master. > > Update the BZ reference. > > Update the test case. > > --- > > lib/conntrack.c | 252 ++++++++++++++-------------------------- > > tests/system-traffic.at | 66 +++++++++++ > > 2 files changed, 155 insertions(+), 163 deletions(-) > > > > diff --git a/lib/conntrack.c b/lib/conntrack.c > > index 550b2be9b..9a9959efc 100644 > > --- a/lib/conntrack.c > > +++ b/lib/conntrack.c > > @@ -764,109 +764,59 @@ handle_alg_ctl(struct conntrack *ct, const struct > conn_lookup_ctx *ctx, > > } > > > > static void > > -pat_packet(struct dp_packet *pkt, const struct conn *conn) > > +pat_packet(struct dp_packet *pkt, const struct conn_key *key) > > { > > - if (conn->nat_action & NAT_ACTION_SRC) { > > - if (conn->key.nw_proto == IPPROTO_TCP) { > > - struct tcp_header *th = dp_packet_l4(pkt); > > - packet_set_tcp_port(pkt, conn->rev_key.dst.port, > th->tcp_dst); > > - } else if (conn->key.nw_proto == IPPROTO_UDP) { > > - struct udp_header *uh = dp_packet_l4(pkt); > > - packet_set_udp_port(pkt, conn->rev_key.dst.port, > uh->udp_dst); > > - } > > - } else if (conn->nat_action & NAT_ACTION_DST) { > > - if (conn->key.nw_proto == IPPROTO_TCP) { > > - packet_set_tcp_port(pkt, conn->rev_key.dst.port, > > - conn->rev_key.src.port); > > - } else if (conn->key.nw_proto == IPPROTO_UDP) { > > - packet_set_udp_port(pkt, conn->rev_key.dst.port, > > - conn->rev_key.src.port); > > - } > > + if (key->nw_proto == IPPROTO_TCP) { > > + packet_set_tcp_port(pkt, key->dst.port, key->src.port); > > + } else if (key->nw_proto == IPPROTO_UDP) { > > + packet_set_udp_port(pkt, key->dst.port, key->src.port); > > } > > } > > > > -static void > > -nat_packet(struct dp_packet *pkt, const struct conn *conn, bool related) > > +static uint16_t > > +nat_action_reverse(uint16_t nat_action) > > { > > - if (conn->nat_action & NAT_ACTION_SRC) { > > - pkt->md.ct_state |= CS_SRC_NAT; > > - if (conn->key.dl_type == htons(ETH_TYPE_IP)) { > > - struct ip_header *nh = dp_packet_l3(pkt); > > - packet_set_ipv4_addr(pkt, &nh->ip_src, > > - conn->rev_key.dst.addr.ipv4); > > - } else { > > - struct ovs_16aligned_ip6_hdr *nh6 = dp_packet_l3(pkt); > > - packet_set_ipv6_addr(pkt, conn->key.nw_proto, > > - nh6->ip6_src.be32, > > - &conn->rev_key.dst.addr.ipv6, true); > > - } > > - if (!related) { > > - pat_packet(pkt, conn); > > - } > > - } else if (conn->nat_action & NAT_ACTION_DST) { > > - pkt->md.ct_state |= CS_DST_NAT; > > - if (conn->key.dl_type == htons(ETH_TYPE_IP)) { > > - struct ip_header *nh = dp_packet_l3(pkt); > > - packet_set_ipv4_addr(pkt, &nh->ip_dst, > > - conn->rev_key.src.addr.ipv4); > > - } else { > > - struct ovs_16aligned_ip6_hdr *nh6 = dp_packet_l3(pkt); > > - packet_set_ipv6_addr(pkt, conn->key.nw_proto, > > - nh6->ip6_dst.be32, > > - &conn->rev_key.src.addr.ipv6, true); > > - } > > - if (!related) { > > - pat_packet(pkt, conn); > > - } > > + if (nat_action & NAT_ACTION_SRC) { > > + nat_action ^= NAT_ACTION_SRC; > > + nat_action |= NAT_ACTION_DST; > > + } else if (nat_action & NAT_ACTION_DST) { > > + nat_action ^= NAT_ACTION_DST; > > + nat_action |= NAT_ACTION_SRC; > > } > > + return nat_action; > > } > > > > static void > > -un_pat_packet(struct dp_packet *pkt, const struct conn *conn) > > +nat_packet_ipv4(struct dp_packet *pkt, const struct conn_key *key, > > + uint16_t nat_action) > > { > > - if (conn->nat_action & NAT_ACTION_SRC) { > > - if (conn->key.nw_proto == IPPROTO_TCP) { > > - struct tcp_header *th = dp_packet_l4(pkt); > > - packet_set_tcp_port(pkt, th->tcp_src, conn->key.src.port); > > - } else if (conn->key.nw_proto == IPPROTO_UDP) { > > - struct udp_header *uh = dp_packet_l4(pkt); > > - packet_set_udp_port(pkt, uh->udp_src, conn->key.src.port); > > - } > > - } else if (conn->nat_action & NAT_ACTION_DST) { > > - if (conn->key.nw_proto == IPPROTO_TCP) { > > - packet_set_tcp_port(pkt, conn->key.dst.port, > conn->key.src.port); > > - } else if (conn->key.nw_proto == IPPROTO_UDP) { > > - packet_set_udp_port(pkt, conn->key.dst.port, > conn->key.src.port); > > - } > > + struct ip_header *nh = dp_packet_l3(pkt); > > + > > + if (nat_action & NAT_ACTION_SRC) { > > + packet_set_ipv4_addr(pkt, &nh->ip_src, key->dst.addr.ipv4); > > + } else if (nat_action & NAT_ACTION_DST) { > > + packet_set_ipv4_addr(pkt, &nh->ip_dst, key->src.addr.ipv4); > > } > > } > > > > static void > > -reverse_pat_packet(struct dp_packet *pkt, const struct conn *conn) > > +nat_packet_ipv6(struct dp_packet *pkt, const struct conn_key *key, > > + uint16_t nat_action) > > { > > - if (conn->nat_action & NAT_ACTION_SRC) { > > - if (conn->key.nw_proto == IPPROTO_TCP) { > > - struct tcp_header *th_in = dp_packet_l4(pkt); > > - packet_set_tcp_port(pkt, conn->key.src.port, > > - th_in->tcp_dst); > > - } else if (conn->key.nw_proto == IPPROTO_UDP) { > > - struct udp_header *uh_in = dp_packet_l4(pkt); > > - packet_set_udp_port(pkt, conn->key.src.port, > > - uh_in->udp_dst); > > - } > > - } else if (conn->nat_action & NAT_ACTION_DST) { > > - if (conn->key.nw_proto == IPPROTO_TCP) { > > - packet_set_tcp_port(pkt, conn->key.src.port, > > - conn->key.dst.port); > > - } else if (conn->key.nw_proto == IPPROTO_UDP) { > > - packet_set_udp_port(pkt, conn->key.src.port, > > - conn->key.dst.port); > > - } > > + struct ovs_16aligned_ip6_hdr *nh6 = dp_packet_l3(pkt); > > + > > + if (nat_action & NAT_ACTION_SRC) { > > + packet_set_ipv6_addr(pkt, key->nw_proto, nh6->ip6_src.be32, > > + &key->dst.addr.ipv6, true); > > + } else if (nat_action & NAT_ACTION_DST) { > > + packet_set_ipv6_addr(pkt, key->nw_proto, nh6->ip6_dst.be32, > > + &key->src.addr.ipv6, true); > > } > > } > > > > static void > > -reverse_nat_packet(struct dp_packet *pkt, const struct conn *conn) > > +nat_inner_packet(struct dp_packet *pkt, struct conn_key *key, > > + uint16_t nat_action) > > { > > char *tail = dp_packet_tail(pkt); > > uint16_t pad = dp_packet_l2_pad_size(pkt); > > @@ -875,98 +825,77 @@ reverse_nat_packet(struct dp_packet *pkt, const > struct conn *conn) > > uint16_t orig_l3_ofs = pkt->l3_ofs; > > uint16_t orig_l4_ofs = pkt->l4_ofs; > > > > - if (conn->key.dl_type == htons(ETH_TYPE_IP)) { > > - struct ip_header *nh = dp_packet_l3(pkt); > > - struct icmp_header *icmp = dp_packet_l4(pkt); > > - struct ip_header *inner_l3 = (struct ip_header *) (icmp + 1); > > - /* This call is already verified to succeed during the code > path from > > - * 'conn_key_extract()' which calls 'extract_l4_icmp()'. */ > > - extract_l3_ipv4(&inner_key, inner_l3, tail - ((char *)inner_l3) > - pad, > > + void *l3 = dp_packet_l3(pkt); > > + void *l4 = dp_packet_l4(pkt); > > + void *inner_l3 = (char *) l4 + 8; > > I understand you hardcoded this because the size of the ICMPv4 and v6 > headers is in both cases 8 but it should be quite easy to avoid this if > you set inner_l3 on both branches of the "if" statement below. > Ack, it makes it more explicit, done in v5. > > > + > > + /* These calls are already verified to succeed during the code path > from > > + * 'conn_key_extract()' which calls > > + * 'extract_l4_icmp()'/'extract_l4_icmp6()'. */ > > + if (key->dl_type == htons(ETH_TYPE_IP)) { > > + extract_l3_ipv4(&inner_key, inner_l3, tail - ((char *) > inner_l3) - pad, > > &inner_l4, false); > > - pkt->l3_ofs += (char *) inner_l3 - (char *) nh; > > - pkt->l4_ofs += inner_l4 - (char *) icmp; > > + } else { > > + extract_l3_ipv6(&inner_key, inner_l3, tail - ((char *) > inner_l3) - pad, > > + &inner_l4); > > + } > > + pkt->l3_ofs += (char *) inner_l3 - (char *) l3; > > + pkt->l4_ofs += inner_l4 - (char *) l4; > > > > - if (conn->nat_action & NAT_ACTION_SRC) { > > - packet_set_ipv4_addr(pkt, &inner_l3->ip_src, > > - conn->key.src.addr.ipv4); > > - } else if (conn->nat_action & NAT_ACTION_DST) { > > - packet_set_ipv4_addr(pkt, &inner_l3->ip_dst, > > - conn->key.dst.addr.ipv4); > > - } > > + /* Reverse the key for inner packet. */ > > + conn_key_reverse(key); > > Isn't it more clear if we use a copy of the key, e.g.: > > struct conn_key rev_key = *key; > conn_key_reverse(&rev_key); > > Then we don't need to re-reverse the key at the end of this function. > Performance wise I think there's no impact eitherway. > You are right it might be less confusing and less error prone if anything will change within this area. > > > > > - reverse_pat_packet(pkt, conn); > > + pat_packet(pkt, key); > > + > > + if (key->dl_type == htons(ETH_TYPE_IP)) { > > + nat_packet_ipv4(pkt, key, nat_action); > > + > > + struct icmp_header *icmp = (struct icmp_header *) l4; > > icmp->icmp_csum = 0; > > icmp->icmp_csum = csum(icmp, tail - (char *) icmp - pad); > > } else { > > - struct ovs_16aligned_ip6_hdr *nh6 = dp_packet_l3(pkt); > > - struct icmp6_data_header *icmp6 = dp_packet_l4(pkt); > > - struct ovs_16aligned_ip6_hdr *inner_l3_6 = > > - (struct ovs_16aligned_ip6_hdr *) (icmp6 + 1); > > - /* This call is already verified to succeed during the code > path from > > - * 'conn_key_extract()' which calls 'extract_l4_icmp6()'. */ > > - extract_l3_ipv6(&inner_key, inner_l3_6, > > - tail - ((char *)inner_l3_6) - pad, > > - &inner_l4); > > - pkt->l3_ofs += (char *) inner_l3_6 - (char *) nh6; > > - pkt->l4_ofs += inner_l4 - (char *) icmp6; > > - > > - if (conn->nat_action & NAT_ACTION_SRC) { > > - packet_set_ipv6_addr(pkt, conn->key.nw_proto, > > - inner_l3_6->ip6_src.be32, > > - &conn->key.src.addr.ipv6, true); > > - } else if (conn->nat_action & NAT_ACTION_DST) { > > - packet_set_ipv6_addr(pkt, conn->key.nw_proto, > > - inner_l3_6->ip6_dst.be32, > > - &conn->key.dst.addr.ipv6, true); > > - } > > - reverse_pat_packet(pkt, conn); > > + nat_packet_ipv6(pkt, key, nat_action); > > + > > + struct icmp6_data_header *icmp6 = (struct icmp6_data_header *) > l4; > > icmp6->icmp6_base.icmp6_cksum = 0; > > - icmp6->icmp6_base.icmp6_cksum = packet_csum_upperlayer6(nh6, > icmp6, > > - IPPROTO_ICMPV6, tail - (char *) icmp6 - pad); > > + icmp6->icmp6_base.icmp6_cksum = > > + packet_csum_upperlayer6(l3, icmp6, IPPROTO_ICMPV6, > > + tail - (char *) icmp6 - pad); > > } > > + > > + /* Return the key and offset back. */ > > + conn_key_reverse(key); > > pkt->l3_ofs = orig_l3_ofs; > > pkt->l4_ofs = orig_l4_ofs; > > } > > > > static void > > -un_nat_packet(struct dp_packet *pkt, const struct conn *conn, > > - bool related) > > +nat_packet(struct dp_packet *pkt, struct conn *conn, bool reply, bool > related) > > { > > - if (conn->nat_action & NAT_ACTION_SRC) { > > - pkt->md.ct_state |= CS_DST_NAT; > > - if (conn->key.dl_type == htons(ETH_TYPE_IP)) { > > - struct ip_header *nh = dp_packet_l3(pkt); > > - packet_set_ipv4_addr(pkt, &nh->ip_dst, > > - conn->key.src.addr.ipv4); > > - } else { > > - struct ovs_16aligned_ip6_hdr *nh6 = dp_packet_l3(pkt); > > - packet_set_ipv6_addr(pkt, conn->key.nw_proto, > > - nh6->ip6_dst.be32, > > - &conn->key.src.addr.ipv6, true); > > - } > > + struct conn_key *key = reply ? &conn->key : &conn->rev_key; > > + uint16_t nat_action = reply ? nat_action_reverse(conn->nat_action) > > + : conn->nat_action; > > > > - if (OVS_UNLIKELY(related)) { > > - reverse_nat_packet(pkt, conn); > > - } else { > > - un_pat_packet(pkt, conn); > > - } > > - } else if (conn->nat_action & NAT_ACTION_DST) { > > + /* Update ct_state. */ > > + if (nat_action & NAT_ACTION_SRC) { > > pkt->md.ct_state |= CS_SRC_NAT; > > - if (conn->key.dl_type == htons(ETH_TYPE_IP)) { > > - struct ip_header *nh = dp_packet_l3(pkt); > > - packet_set_ipv4_addr(pkt, &nh->ip_src, > > - conn->key.dst.addr.ipv4); > > - } else { > > - struct ovs_16aligned_ip6_hdr *nh6 = dp_packet_l3(pkt); > > - packet_set_ipv6_addr(pkt, conn->key.nw_proto, > > - nh6->ip6_src.be32, > > - &conn->key.dst.addr.ipv6, true); > > - } > > + } else if (nat_action & NAT_ACTION_DST) { > > + pkt->md.ct_state |= CS_DST_NAT; > > + } > > > > + /* Reverse the key for outer header. */ > > + if (key->dl_type == htons(ETH_TYPE_IP)) { > > + nat_packet_ipv4(pkt, key, nat_action); > > + } else { > > + nat_packet_ipv6(pkt, key, nat_action); > > + } > > + > > + if (nat_action & NAT_ACTION_SRC || nat_action & NAT_ACTION_DST) { > > if (OVS_UNLIKELY(related)) { > > - reverse_nat_packet(pkt, conn); > > + nat_action = nat_action_reverse(conn->nat_action); > > Nit: one space too many. > Interesting I can see it aligned, not sure why the diff here shows it with extra space. > > > + nat_inner_packet(pkt, key, nat_action); > > } else { > > - un_pat_packet(pkt, conn); > > + pat_packet(pkt, key); > > } > > } > > } > > @@ -1082,7 +1011,7 @@ conn_not_found(struct conntrack *ct, struct > dp_packet *pkt, > > memcpy(nc, nat_conn, sizeof *nc); > > } > > > > - nat_packet(pkt, nc, ctx->icmp_related); > > + nat_packet(pkt, nc, false, ctx->icmp_related); > > memcpy(&nat_conn->key, &nc->rev_key, sizeof nat_conn->key); > > memcpy(&nat_conn->rev_key, &nc->key, sizeof > nat_conn->rev_key); > > nat_conn->conn_type = CT_CONN_TYPE_UN_NAT; > > @@ -1185,11 +1114,8 @@ handle_nat(struct dp_packet *pkt, struct conn > *conn, > > if (pkt->md.ct_state & (CS_SRC_NAT | CS_DST_NAT)) { > > pkt->md.ct_state &= ~(CS_SRC_NAT | CS_DST_NAT); > > } > > - if (reply) { > > - un_nat_packet(pkt, conn, related); > > - } else { > > - nat_packet(pkt, conn, related); > > - } > > + > > + nat_packet(pkt, conn, reply, related); > > } > > } > > > > diff --git a/tests/system-traffic.at b/tests/system-traffic.at > > index 503455cc6..fe084e35a 100644 > > --- a/tests/system-traffic.at > > +++ b/tests/system-traffic.at > > @@ -7130,6 +7130,72 @@ > recirc_id(0),in_port(br-underlay),ct_state(+trk),eth(src=f0:00:00:01:01:02,dst=f > > OVS_TRAFFIC_VSWITCHD_STOP > > AT_CLEANUP > > > > +AT_SETUP([conntrack - ICMP from different source related with NAT]) > > Thanks for adding a test! > > > +AT_SKIP_IF([test $HAVE_NC = no]) > > +AT_SKIP_IF([test $HAVE_TCPDUMP = no]) > > +CHECK_CONNTRACK() > > +CHECK_CONNTRACK_NAT() > > +OVS_TRAFFIC_VSWITCHD_START() > > + > > +ADD_NAMESPACES(client, server) > > + > > +ADD_VETH(client, client, br0, "192.168.20.10/24", "00:00:00:00:20:10") > > +ADD_VETH(server, server, br0, "192.168.10.20/24", "00:00:00:00:10:20") > > + > > +dnl Send traffic from client to CT, do DNAT if the traffic is new > otherwise send it to server > > +AT_DATA([flows.txt], [dnl > > +table=0,ip,ct_state=-trk,actions=ct(table=1) > > We didn't send to conntrack before, it feels a bit weird to match on > ct_state (even if we match on -trk). > > Which makes me wonder, shouldn't we actually try to un-nat too? And, to > make it more resilient we should probably use a non-default zone, to > avoid existing conntrack entries in the defauly kernel zone. > > So, to be pedantic, I think this should be changed to something like: > > table=0,ip,actions=ct(table=1,zone=42,nat) > Ack, it definitely shouldn't hurt, added in v5. > > > > +table=1,in_port=ovs-client,ip,ct_state=+trk+new,actions=ct(commit,table=2,nat(dst(192.168.10.20)) > > > +table=1,in_port=ovs-client,icmp,ct_state=+trk+rel,actions=ct(commit,table=2,nat) > > +table=1,ip,actions=resubmit(,2) > > > +table=2,in_port=ovs-client,ip,ct_state=+trk+new,actions=output:ovs-server > > > +table=2,in_port=ovs-client,icmp,ct_state=+trk+rel,actions=output:ovs-server > > > +table=2,in_port=ovs-server,ip,ct_state=+trk+rpl,actions=output:ovs-client > > +]) > > + > > +AT_CHECK([ovs-ofctl add-flows br0 flows.txt]) > > + > > +rm server.pcap > > +OVS_DAEMONIZE([tcpdump -U -i ovs-server -w server.pcap], [tcpdump.pid]) > > +sleep 1 > > + > > +dnl Send UDP client->server > > +AT_CHECK([ovs-ofctl packet-out br0 "in_port=ovs-client,\ > > > +packet=00000000102000000000201008004500001C000040000A11C762C0A8140AC0A814140001000200080000,actions=resubmit(,0)"]) > > +dnl Send UDP response server->client > > +AT_CHECK([ovs-ofctl packet-out br0 "in_port=ovs-server,\ > > > +packet=00000000201000000000102008004500001C000040000A11D162C0A80A14C0A8140A0002000100080000,actions=resubmit(,0)"]) > > +dnl Fake router sending ICMP need frag > > +AT_CHECK([ovs-ofctl packet-out br0 "in_port=ovs-client,\ > > > +packet=000000001020000000002000080045000038011F0000FF011140C0A81401C0A814140304F778000005784500001C000040000A11C762C0A81414C0A8140A0002000100080000,\ > > +actions=resubmit(,0)" > > +]) > > + > > +AT_CHECK([ovs-appctl revalidator/purge], [0]) > > +AT_CHECK([ovs-ofctl -O OpenFlow15 dump-flows br0 | ofctl_strip | sort > ], [0], [dnl > > + n_packets=3, n_bytes=154, reset_counts ct_state=-trk,ip > actions=ct(table=1) > > + table=1, n_packets=1, n_bytes=42, reset_counts > ct_state=+new+trk,ip,in_port=1 > actions=ct(commit,table=2,nat(dst=192.168.10.20)) > > + table=1, n_packets=1, n_bytes=42, reset_counts ip actions=resubmit(,2) > > + table=1, n_packets=1, n_bytes=70, reset_counts > ct_state=+rel+trk,icmp,in_port=1 actions=ct(commit,table=2,nat) > > + table=2, n_packets=1, n_bytes=42, reset_counts > ct_state=+new+trk,ip,in_port=1 actions=output:2 > > + table=2, n_packets=1, n_bytes=42, reset_counts > ct_state=+rpl+trk,ip,in_port=2 actions=output:1 > > + table=2, n_packets=1, n_bytes=70, reset_counts > ct_state=+rel+trk,icmp,in_port=1 actions=output:2 > > +OFPST_FLOW reply (OF1.5): > > +]) > > + > > +AT_CHECK([ovs-appctl dpctl/dump-conntrack | grep "192.168.20.10"], [0], > [dnl > > > +udp,orig=(src=192.168.20.10,dst=192.168.20.20,sport=1,dport=2),reply=(src=192.168.10.20,dst=192.168.20.10,sport=2,dport=1) > > +]) > > + > > +OVS_WAIT_UNTIL([ovs-pcap server.pcap | grep 000000001020000000002000]) > > + > > +AT_CHECK([ovs-pcap server.pcap | grep 000000001020000000002000], [0], > [dnl > > > +000000001020000000002000080045000038011f0000ff011b40c0a81401c0a80a140304f778000005784500001c000040000a11d162c0a80a14c0a8140a0002000100080000 > > +]) > > + > > +OVS_TRAFFIC_VSWITCHD_STOP > > +AT_CLEANUP > > + > > AT_BANNER([IGMP]) > > > > AT_SETUP([IGMP - flood under normal action]) > > Regards, > Dumitru > > Thanks, Ales -- Ales Musil Senior Software Engineer - OVN Core Red Hat EMEA <https://www.redhat.com> [email protected] IM: amusil <https://red.ht/sig> _______________________________________________ dev mailing list [email protected] https://mail.openvswitch.org/mailman/listinfo/ovs-dev
