From 11f75ad5bef3d2f6a9d72a8b27468fc3ccfc3d7e Mon Sep 17 00:00:00 2001

From: Numan Siddique <numans@ovn.org>

Date: Fri, 22 Jan 2021 13:52:29 +0530

Subject: [PATCH] ovn-controller: Fix wrong conj_id match flows when caching is

 enabled.

When the below ACL is added -

ovn-nbctl acl-add ls1 to-lport 3

  '(ip4.src==10.0.0.1 || ip4.src==10.0.0.2) &&

   (ip4.dst == 10.0.0.3 || ip4.dst == 10.0.0.4)' allow

ovn-controller installs the below OF flows

table=45, priority=1003,ip,metadata=0x1,nw_dst=10.0.0.4 actions=conjunction(2,1/2)

table=45, priority=1003,ip,metadata=0x1,nw_dst=10.0.0.3 actions=conjunction(2,1/2)

table=45, priority=1003,ip,metadata=0x1,nw_src=10.0.0.2 actions=conjunction(2,2/2)

table=45, priority=1003,ip,metadata=0x1,nw_src=10.0.0.1 actions=conjunction(2,2/2)

table=45, priority=1003,conj_id=2,ip,metadata=0x1 actions=resubmit(,46)

When a full recompute is triggered, ovn-controller deletes the last

OF flow with the match conj_id=2 and adds the below OF flow

table=45, priority=1003,conj_id=3,ip,metadata=0x1 actions=resubmit(,46)

For subsequent recomputes, the conj_id keeps increasing by 1.

This disrupts the traffic which matches on conjuction action flows.

This patch fixes this issue.

Fixes: 1213bc8270("ovn-controller: Cache logical flow expr matches.")

Suggested-by: Dumitru Ceara <dceara@redhat.com>

Acked-by: Dumitru Ceara <dceara@redhat.com>

Signed-off-by: Numan Siddique <numans@ovn.org>

(cherry-picked from master commit c83294970c62f662015a7979b12250580bee3001)

---

 controller/lflow.c | 30 ++++++++++++++----------------

 include/ovn/expr.h |  1 +

 lib/expr.c         | 19 +++++++++++++++++++

 tests/ovn.at       | 28 ++++++++++++++++++++++++++++

 4 files changed, 62 insertions(+), 16 deletions(-)

diff --git a/controller/lflow.c b/controller/lflow.c

index c02585b1e..9f6aece9a 100644

--- a/controller/lflow.c

+++ b/controller/lflow.c

@@ -668,9 +668,8 @@ update_conj_id_ofs(uint32_t *conj_id_ofs, uint32_t n_conjs)

 static void

 add_matches_to_flow_table(const struct sbrec_logical_flow *lflow,

                           const struct sbrec_datapath_binding *dp,

-                          struct hmap *matches, size_t conj_id_ofs,

-                          uint8_t ptable, uint8_t output_ptable,

-                          struct ofpbuf *ovnacts,

+                          struct hmap *matches, uint8_t ptable,

+                          uint8_t output_ptable, struct ofpbuf *ovnacts,

                           bool ingress, struct lflow_ctx_in *l_ctx_in,

                           struct lflow_ctx_out *l_ctx_out)

 {

@@ -708,9 +707,6 @@ add_matches_to_flow_table(const struct sbrec_logical_flow *lflow,

     struct expr_match *m;

     HMAP_FOR_EACH (m, hmap_node, matches) {

         match_set_metadata(&m->match, htonll(dp->tunnel_key));

-        if (m->match.wc.masks.conj_id) {

-            m->match.flow.conj_id += conj_id_ofs;

-        }

         if (datapath_is_switch(dp)) {

             unsigned int reg_index

                 = (ingress ? MFF_LOG_INPORT : MFF_LOG_OUTPORT) - MFF_REG0;

@@ -744,7 +740,7 @@ add_matches_to_flow_table(const struct sbrec_logical_flow *lflow,

                 struct ofpact_conjunction *dst;

                 dst = ofpact_put_CONJUNCTION(&conj;;

-                dst->id = src->id + conj_id_ofs;

+                dst->id = src->id;

                 dst->clause = src->clause;

                 dst->n_clauses = src->n_clauses;

             }

@@ -915,9 +911,9 @@ consider_logical_flow__(const struct sbrec_logical_flow *lflow,

             return true;

         }

-        add_matches_to_flow_table(lflow, dp, &matches, *l_ctx_out->conj_id_ofs,

-                                  ptable, output_ptable, &ovnacts, ingress,

-                                  l_ctx_in, l_ctx_out);

+        expr_matches_prepare(&matches, *l_ctx_out->conj_id_ofs);

+        add_matches_to_flow_table(lflow, dp, &matches, ptable, output_ptable,

+                                  &ovnacts, ingress, l_ctx_in, l_ctx_out);

         ovnacts_free(ovnacts.data, ovnacts.size);

         ofpbuf_uninit(&ovnacts);

@@ -930,10 +926,11 @@ consider_logical_flow__(const struct sbrec_logical_flow *lflow,

         lflow_cache_get(l_ctx_out->lflow_cache_map, lflow);

     if (lc && lc->type == LCACHE_T_MATCHES) {

-        /* 'matches' is cached. No need to do expr parsing.

+        /* 'matches' is cached. No need to do expr parsing and no need

+         * to call expr_matches_prepare() to update the conj ids.

          * Add matches to flow table and return. */

-        add_matches_to_flow_table(lflow, dp, lc->expr_matches, lc->conj_id_ofs,

-                                  ptable, output_ptable, &ovnacts, ingress,

+        add_matches_to_flow_table(lflow, dp, lc->expr_matches, ptable,

+                                  output_ptable, &ovnacts, ingress,

                                   l_ctx_in, l_ctx_out);

         ovnacts_free(ovnacts.data, ovnacts.size);

         ofpbuf_uninit(&ovnacts);

@@ -1009,10 +1006,11 @@ consider_logical_flow__(const struct sbrec_logical_flow *lflow,

         }

     }

+    expr_matches_prepare(matches, lc->conj_id_ofs);

+

     /* Encode OVN logical actions into OpenFlow. */

-    add_matches_to_flow_table(lflow, dp, matches, lc->conj_id_ofs,

-                              ptable, output_ptable, &ovnacts, ingress,

-                              l_ctx_in, l_ctx_out);

+    add_matches_to_flow_table(lflow, dp, matches, ptable, output_ptable,

+                              &ovnacts, ingress, l_ctx_in, l_ctx_out);

     ovnacts_free(ovnacts.data, ovnacts.size);

     ofpbuf_uninit(&ovnacts);

diff --git a/include/ovn/expr.h b/include/ovn/expr.h

index 0a83ec7a8..c2c821818 100644

--- a/include/ovn/expr.h

+++ b/include/ovn/expr.h

@@ -477,6 +477,7 @@ uint32_t expr_to_matches(const struct expr *,

                          const void *aux,

                          struct hmap *matches);

 void expr_matches_destroy(struct hmap *matches);

+void expr_matches_prepare(struct hmap *matches, uint32_t conj_id_ofs);

 void expr_matches_print(const struct hmap *matches, FILE *);

 /* Action parsing helper. */

diff --git a/lib/expr.c b/lib/expr.c

index 4566d9110..796e88ac7 100644

--- a/lib/expr.c

+++ b/lib/expr.c

@@ -3125,6 +3125,25 @@ expr_to_matches(const struct expr *expr,

     return n_conjs;

 }

+/* Prepares the expr matches in the hmap 'matches' by updating the

+ * conj id offsets specified in 'conj_id_ofs'.

+ */

+void

+expr_matches_prepare(struct hmap *matches, uint32_t conj_id_ofs)

+{

+    struct expr_match *m;

+    HMAP_FOR_EACH (m, hmap_node, matches) {

+        if (m->match.wc.masks.conj_id) {

+            m->match.flow.conj_id += conj_id_ofs;

+        }

+

+        for (size_t i = 0; i < m->n; i++) {

+            struct cls_conjunction *src = &m->conjunctions[i];

+            src->id += conj_id_ofs;

+        }

+    }

+}

+

 /* Destroys all of the 'struct expr_match'es in 'matches', as well as the

  * 'matches' hmap itself. */

 void

diff --git a/tests/ovn.at b/tests/ovn.at

index e2d2d8a9d..b890592ae 100644

--- a/tests/ovn.at

+++ b/tests/ovn.at

@@ -13824,6 +13824,34 @@ reset_pcap_file hv1-vif2 hv1/vif2

 rm -f 2.packets

 > 2.expected

+# Trigger recompute and make sure that the traffic still works as expected.

+as hv1 ovn-appctl -t ovn-controller recompute

+

+# Traffic 10.0.0.1, 10.0.0.2 -> 10.0.0.3, 10.0.0.4 should be allowed.

+for src in `seq 1 2`; do

+    for dst in `seq 3 4`; do

+        sip=`ip_to_hex 10 0 0 $src`

+        dip=`ip_to_hex 10 0 0 $dst`

+

+        test_ip 1 f00000000001 f00000000002 $sip $dip 2

+    done

+done

+

+# Traffic 10.0.0.1, 10.0.0.2 -> 10.0.0.5 should be dropped.

+dip=`ip_to_hex 10 0 0 5`

+for src in `seq 1 2`; do

+    sip=`ip_to_hex 10 0 0 $src`

+

+    test_ip 1 f00000000001 f00000000002 $sip $dip

+done

+

+cat 2.expected > expout

+$PYTHON "$ovs_srcdir/utilities/ovs-pcap.in" hv1/vif2-tx.pcap > 2.packets

+AT_CHECK([cat 2.packets], [0], [expout])

+reset_pcap_file hv1-vif2 hv1/vif2

+rm -f 2.packets

+> 2.expected

+

 # Add two less restrictive allow ACLs for src IP 10.0.0.1.

 ovn-nbctl acl-add ls1 to-lport 3 'ip4.src==10.0.0.1 || ip4.src==10.0.0.1' allow

 ovn-nbctl acl-add ls1 to-lport 3 'ip4.src==10.0.0.1' allow

-- 

2.29.2