I just wanted to specially call out this patch for testing. My hope is that we
can merge this into 2.8, but wanted to give people a heads up that they may
want to try it with their applications. The most visible change is that a call
to ct() will clear the ct_state for any actions that follow it. As before, the
ct_state will be accessible to flows rooted in the table specified by the
"table" argument to ct(), but now another ct() action will clear the state for
the current processing path (but the new ct_state will be available if the
"table" argument is given).
My hope is that this won't affect people's pipelines, but it's worth checking
if it does. I would recommend that anyone that uses the conntrack action in
their applications give this patch a try (on top of branch-2.8). If there are
any problems, I can try to help you reconstruct your pipeline so it's not
affected. (The changes should be minimal, and there are a couple of examples
in the patch itself.) I've done some light testing with OVN, and it didn't
require any changes, and I hope it's the same for everyone else.
The reason I'd like to get this change into 2.8 is that it's a requirement for
a performance optimization I'd like to get into 2.9. Currently, if a
controller action is specified, all traffic is slow-pathed to userspace. As we
start making heavier use of local controllers, this will have a serious
negative effect on forwarding performance and increase in CPU usage. I've made
a few other (more minor, corner-casey) changes to the OpenFlow processing in
2.8, and I'd like to get all potentially breaking issues into a single release.
If you have an application that uses conntrack, please give it a try and let me
know if you run into any issues.
Thanks!
--Justin
> On Aug 10, 2017, at 11:38 PM, Justin Pettit <jpet...@ovn.org> wrote:
>
> Packet and Connection state is only available to the processing path
> that follows the "recirc_table" argument of the ct() action. The
> previous behavior made these states available until the end of the
> pipeline. This commit changes the behavior so that the Packet and
> Connection state are cleared for the current processing path whenever
> ct() is called (in addition to reaching the end of the pipeline.)
>
> A future commit will remove the behavior that a "send to controller"
> action causes all packets for that flow to be handled via the slow-path.
> The current behavior of connection tracking state makes that difficult
> due to datapath actions containing multiple OpenFlow rules that may
> contain different connection tracking states. This change will make
> that future commit possible.
>
> Signed-off-by: Justin Pettit <jpet...@ovn.org>
> ---
> v1->v2: Fix system tests.
> ---
> lib/ofp-actions.c | 27 +++++++++++++--------------
> ofproto/ofproto-dpif-xlate.c | 21 +++++++--------------
> tests/ofproto-dpif.at | 10 +++++-----
> tests/system-traffic.at | 4 ++--
> utilities/ovs-ofctl.8.in | 10 ++++++----
> 5 files changed, 33 insertions(+), 39 deletions(-)
>
> diff --git a/lib/ofp-actions.c b/lib/ofp-actions.c
> index bfc8a805ffd5..71eb70c3c239 100644
> --- a/lib/ofp-actions.c
> +++ b/lib/ofp-actions.c
> @@ -5858,20 +5858,19 @@ format_DEBUG_RECIRC(const struct ofpact_null *a
> OVS_UNUSED,
> *
> * - Packet State:
> *
> - * Untracked packets have not yet passed through the connection tracker,
> - * and the connection state for such packets is unknown. In most cases,
> - * packets entering the OpenFlow pipeline will initially be in the
> - * untracked state. Untracked packets may become tracked by executing
> - * NXAST_CT with a "recirc_table" specified. This makes various aspects
> - * about the connection available, in particular the connection state.
> - *
> - * Tracked packets have previously passed through the connection
> tracker.
> - * These packets will remain tracked through until the end of the
> OpenFlow
> - * pipeline. Tracked packets which have NXAST_CT executed with a
> - * "recirc_table" specified will return to the tracked state.
> - *
> - * The packet state is only significant for the duration of packet
> - * processing within the OpenFlow pipeline.
> + * Untracked packets have an unknown connection state. In most
> + * cases, packets entering the OpenFlow pipeline will initially be
> + * in the untracked state. Untracked packets may become tracked by
> + * executing NXAST_CT with a "recirc_table" specified. This makes
> + * various aspects about the connection available, in particular
> + * the connection state.
> + *
> + * An NXAST_CT action always puts the packet into an untracked
> + * state for the current processing path. If "recirc_table" is
> + * set, execution is forked and the packet passes through the
> + * connection tracker. The specified table's processing path is
> + * able to match on Connection state until the end of the OpenFlow
> + * pipeline or NXAST_CT is called again.
> *
> * - Connection State:
> *
> diff --git a/ofproto/ofproto-dpif-xlate.c b/ofproto/ofproto-dpif-xlate.c
> index 973e760547fa..9e1f837cb23e 100644
> --- a/ofproto/ofproto-dpif-xlate.c
> +++ b/ofproto/ofproto-dpif-xlate.c
> @@ -5721,9 +5721,7 @@ put_ct_nat(struct xlate_ctx *ctx)
> static void
> compose_conntrack_action(struct xlate_ctx *ctx, struct ofpact_conntrack *ofc)
> {
> - ovs_u128 old_ct_label = ctx->xin->flow.ct_label;
> ovs_u128 old_ct_label_mask = ctx->wc->masks.ct_label;
> - uint32_t old_ct_mark = ctx->xin->flow.ct_mark;
> uint32_t old_ct_mark_mask = ctx->wc->masks.ct_mark;
> size_t ct_offset;
> uint16_t zone;
> @@ -5735,7 +5733,7 @@ compose_conntrack_action(struct xlate_ctx *ctx, struct
> ofpact_conntrack *ofc)
> /* Process nested actions first, to populate the key. */
> ctx->ct_nat_action = NULL;
> ctx->wc->masks.ct_mark = 0;
> - ctx->wc->masks.ct_label.u64.hi = ctx->wc->masks.ct_label.u64.lo = 0;
> + ctx->wc->masks.ct_label = OVS_U128_ZERO;
> do_xlate_actions(ofc->actions, ofpact_ct_get_action_len(ofc), ctx);
>
> if (ofc->zone_src.field) {
> @@ -5761,23 +5759,18 @@ compose_conntrack_action(struct xlate_ctx *ctx,
> struct ofpact_conntrack *ofc)
> ctx->ct_nat_action = NULL;
> nl_msg_end_nested(ctx->odp_actions, ct_offset);
>
> - /* Restore the original ct fields in the key. These should only be
> exposed
> - * after recirculation to another table. */
> - ctx->xin->flow.ct_mark = old_ct_mark;
> ctx->wc->masks.ct_mark = old_ct_mark_mask;
> - ctx->xin->flow.ct_label = old_ct_label;
> ctx->wc->masks.ct_label = old_ct_label_mask;
>
> - if (ofc->recirc_table == NX_CT_RECIRC_NONE) {
> - /* If we do not recirculate as part of this action, hide the results
> of
> - * connection tracking from subsequent recirculations. */
> - ctx->conntracked = false;
> - } else {
> - /* Use ct_* fields from datapath during recirculation upcall. */
> + if (ofc->recirc_table != NX_CT_RECIRC_NONE) {
> ctx->conntracked = true;
> compose_recirculate_and_fork(ctx, ofc->recirc_table);
> - ctx->conntracked = false;
> }
> +
> + /* The ct_* fields are only available in the scope of the 'recirc_table'
> + * call chain. */
> + flow_clear_conntrack(&ctx->xin->flow);
> + ctx->conntracked = false;
> }
>
> static void
> diff --git a/tests/ofproto-dpif.at b/tests/ofproto-dpif.at
> index 284a65ec6524..28a7e827cac2 100644
> --- a/tests/ofproto-dpif.at
> +++ b/tests/ofproto-dpif.at
> @@ -8949,7 +8949,7 @@ OVS_WAIT_UNTIL([ovs-appctl -t ovs-ofctl exit])
>
> dnl Check this output. We only see the latter two packets, not the first.
> AT_CHECK([cat ofctl_monitor.log], [0], [dnl
> -NXT_PACKET_IN (xid=0x0): table_id=6 cookie=0x0 total_len=42
> ct_state=new|trk,ct_zone=1,ct_nw_src=10.1.1.1,ct_nw_dst=10.1.1.2,ct_nw_proto=17,ct_tp_src=1,ct_tp_dst=2,reg0=0x1,reg1=0x4d2,reg2=0x1,reg3=0x1,reg4=0x1,in_port=1
> (via action) data_len=42 (unbuffered)
> +NXT_PACKET_IN (xid=0x0): table_id=6 cookie=0x0 total_len=42
> reg0=0x1,reg1=0x4d2,reg2=0x1,reg3=0x1,reg4=0x1,in_port=1 (via action)
> data_len=42 (unbuffered)
> udp,vlan_tci=0x0000,dl_src=50:54:00:00:00:09,dl_dst=50:54:00:00:00:0a,nw_src=10.1.1.1,nw_dst=10.1.1.2,nw_tos=0,nw_ecn=0,nw_ttl=64,tp_src=1,tp_dst=2
> udp_csum:e9d6
> dnl
> NXT_PACKET_IN (xid=0x0): table_id=6 cookie=0x0 total_len=42
> ct_state=est|rpl|trk,ct_zone=1,ct_mark=0x1,ct_label=0x4d2000000000000000000000000,ct_nw_src=10.1.1.1,ct_nw_dst=10.1.1.2,ct_nw_proto=17,ct_tp_src=1,ct_tp_dst=2,reg0=0x1,reg1=0x4d2,reg2=0x1,reg3=0x2,reg4=0x1,in_port=2
> (via action) data_len=42 (unbuffered)
> @@ -8970,7 +8970,7 @@ OVS_WAIT_UNTIL([ovs-appctl -t ovs-ofctl exit])
>
> dnl Check this output. We should see both packets
> AT_CHECK([cat ofctl_monitor.log], [0], [dnl
> -NXT_PACKET_IN (xid=0x0): table_id=6 cookie=0x0 total_len=42
> ct_state=new|trk,ct_zone=1,ct_nw_src=10.1.1.1,ct_nw_dst=10.1.1.2,ct_nw_proto=17,ct_tp_src=3,ct_tp_dst=2,reg0=0x1,reg1=0x4d2,reg2=0x1,reg3=0x1,reg4=0x1,in_port=1
> (via action) data_len=42 (unbuffered)
> +NXT_PACKET_IN (xid=0x0): table_id=6 cookie=0x0 total_len=42
> reg0=0x1,reg1=0x4d2,reg2=0x1,reg3=0x1,reg4=0x1,in_port=1 (via action)
> data_len=42 (unbuffered)
> udp,vlan_tci=0x0000,dl_src=50:54:00:00:00:09,dl_dst=50:54:00:00:00:0a,nw_src=10.1.1.1,nw_dst=10.1.1.2,nw_tos=0,nw_ecn=0,nw_ttl=64,tp_src=3,tp_dst=2
> udp_csum:e9d4
> dnl
> NXT_PACKET_IN (xid=0x0): table_id=6 cookie=0x0 total_len=42
> ct_state=est|rpl|trk,ct_zone=1,ct_mark=0x1,ct_label=0x4d2000000000000000000000000,ct_nw_src=10.1.1.1,ct_nw_dst=10.1.1.2,ct_nw_proto=17,ct_tp_src=3,ct_tp_dst=2,reg0=0x1,reg1=0x4d2,reg2=0x1,reg3=0x2,reg4=0x1,in_port=2
> (via action) data_len=42 (unbuffered)
> @@ -9025,7 +9025,7 @@ AT_CHECK([cat ofctl_monitor.log], [0], [dnl
> NXT_PACKET_IN (xid=0x0): cookie=0x0 total_len=42 in_port=1 (via action)
> data_len=42 (unbuffered)
> udp,vlan_tci=0x0000,dl_src=50:54:00:00:00:09,dl_dst=50:54:00:00:00:0a,nw_src=10.1.1.1,nw_dst=10.1.1.2,nw_tos=0,nw_ecn=0,nw_ttl=64,tp_src=1,tp_dst=2
> udp_csum:e9d6
> dnl
> -NXT_PACKET_IN (xid=0x0): table_id=1 cookie=0x0 total_len=42
> ct_state=est|rpl|trk,ct_nw_src=10.1.1.1,ct_nw_dst=10.1.1.2,ct_nw_proto=17,ct_tp_src=1,ct_tp_dst=2,in_port=2
> (via action) data_len=42 (unbuffered)
> +NXT_PACKET_IN (xid=0x0): table_id=1 cookie=0x0 total_len=42 in_port=2 (via
> action) data_len=42 (unbuffered)
> udp,vlan_tci=0x0000,dl_src=50:54:00:00:00:0a,dl_dst=50:54:00:00:00:09,nw_src=10.1.1.2,nw_dst=10.1.1.1,nw_tos=0,nw_ecn=0,nw_ttl=64,tp_src=2,tp_dst=1
> udp_csum:e9d6
> ])
>
> @@ -9047,7 +9047,7 @@ AT_CHECK([cat ofctl_monitor.log], [0], [dnl
> NXT_PACKET_IN (xid=0x0): cookie=0x0 total_len=42 in_port=1 (via action)
> data_len=42 (unbuffered)
> udp,vlan_tci=0x0000,dl_src=50:54:00:00:00:09,dl_dst=50:54:00:00:00:0a,nw_src=10.1.1.1,nw_dst=10.1.1.2,nw_tos=0,nw_ecn=0,nw_ttl=64,tp_src=3,tp_dst=4
> udp_csum:e9d2
> dnl
> -NXT_PACKET_IN (xid=0x0): table_id=1 cookie=0x0 total_len=42
> ct_state=est|rpl|trk,ct_nw_src=10.1.1.1,ct_nw_dst=10.1.1.2,ct_nw_proto=17,ct_tp_src=3,ct_tp_dst=4,in_port=2
> (via action) data_len=42 (unbuffered)
> +NXT_PACKET_IN (xid=0x0): table_id=1 cookie=0x0 total_len=42 in_port=2 (via
> action) data_len=42 (unbuffered)
> udp,vlan_tci=0x0000,dl_src=50:54:00:00:00:0a,dl_dst=50:54:00:00:00:09,nw_src=10.1.1.2,nw_dst=10.1.1.1,nw_tos=0,nw_ecn=0,nw_ttl=64,tp_src=4,tp_dst=3
> udp_csum:e9d2
> ])
>
> @@ -9362,7 +9362,7 @@ OVS_WAIT_UNTIL([ovs-appctl -t ovs-ofctl exit])
>
> dnl Check this output. We only see the latter two packets, not the first.
> AT_CHECK([cat ofctl_monitor.log], [0], [dnl
> -NXT_PACKET_IN (xid=0x0): table_id=1 cookie=0x0 total_len=42
> ct_state=new|trk,ct_nw_src=10.1.1.1,ct_nw_dst=10.1.1.2,ct_nw_proto=17,ct_tp_src=1,ct_tp_dst=2,in_port=1
> (via action) data_len=42 (unbuffered)
> +NXT_PACKET_IN (xid=0x0): table_id=1 cookie=0x0 total_len=42 in_port=1 (via
> action) data_len=42 (unbuffered)
> udp,vlan_tci=0x0000,dl_src=50:54:00:00:00:09,dl_dst=50:54:00:00:00:0a,nw_src=10.1.1.1,nw_dst=10.1.1.2,nw_tos=0,nw_ecn=0,nw_ttl=64,tp_src=1,tp_dst=2
> udp_csum:e9d6
> dnl
> NXT_PACKET_IN (xid=0x0): table_id=1 cookie=0x0 total_len=42
> ct_state=est|rpl|trk,ct_nw_src=10.1.1.1,ct_nw_dst=10.1.1.2,ct_nw_proto=17,ct_tp_src=1,ct_tp_dst=2,in_port=2
> (via action) data_len=42 (unbuffered)
> diff --git a/tests/system-traffic.at b/tests/system-traffic.at
> index 798dd2cbd2c2..522eaa615834 100644
> --- a/tests/system-traffic.at
> +++ b/tests/system-traffic.at
> @@ -2287,7 +2287,7 @@ dnl Ingress pipeline
> dnl - Allow all connections from LOCAL port (commit and proceed to egress)
> dnl - All other connections go through conntracker using the input port as
> dnl a connection tracking zone.
> -table=1,priority=150,in_port=LOCAL,ip,ct_state=+trk+new,action=ct(commit,zone=OXM_OF_IN_PORT[[0..15]]),goto_table:2
> +table=1,priority=150,in_port=LOCAL,ip,ct_state=+trk+new,action=ct(commit,table=2,zone=OXM_OF_IN_PORT[[0..15]])
> table=1,priority=100,ip,action=ct(table=2,zone=OXM_OF_IN_PORT[[0..15]])
> table=1,priority=1,action=drop
>
> @@ -2295,7 +2295,7 @@ dnl Egress pipeline
> dnl - Allow all connections from LOCAL port (commit and skip to output)
> dnl - Allow other established connections to go through conntracker using
> dnl output port as a connection tracking zone.
> -table=2,priority=150,in_port=LOCAL,ip,ct_state=+trk+new,action=ct(commit,zone=NXM_NX_REG0[[0..15]]),goto_table:4
> +table=2,priority=150,in_port=LOCAL,ip,ct_state=+trk+new,action=ct(commit,table=4,zone=NXM_NX_REG0[[0..15]])
> table=2,priority=100,ip,ct_state=+trk+est,action=ct(table=3,zone=NXM_NX_REG0[[0..15]])
> table=2,priority=1,action=drop
>
> diff --git a/utilities/ovs-ofctl.8.in b/utilities/ovs-ofctl.8.in
> index f6bd90374a18..c65de97f5e2e 100644
> --- a/utilities/ovs-ofctl.8.in
> +++ b/utilities/ovs-ofctl.8.in
> @@ -1031,11 +1031,13 @@ Restores the queue to the value it was before any
> \fBset_queue\fR
> actions were applied.
> .
> .IP \fBct\fR
> -.IQ \fBct\fB(\fR[\fIargument\fR][\fB,\fIargument\fR...]\fB)
> +.IQ \fBct(\fR[\fIargument\fR][\fB,\fIargument\fR...]\fB)
> Send the packet through the connection tracker. Refer to the \fBct_state\fR
> -documentation above for possible packet and connection states. The following
> -arguments are supported:
> -
> +documentation above for possible packet and connection states. A \fBct\fR
> +action always sets the packet to an untracked state and clears out the
> +\fBct_state\fR fields for the current processing path. Those fields are
> +only available for the processing path pointed to by the \fBtable\fR
> +argument. The following arguments are supported:
> .RS
> .IP \fBcommit\fR
> .RS
> --
> 2.7.4
>
> _______________________________________________
> dev mailing list
> d...@openvswitch.org
> https://mail.openvswitch.org/mailman/listinfo/ovs-dev
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