diff mbox series

[ovs-dev] expr: Combine multiple ipv4 with wildcard mask.

Message ID BD9FE098-E26A-4F28-9823-90E71C705EFD@tencent.com
State New
Headers show
Series [ovs-dev] expr: Combine multiple ipv4 with wildcard mask. | expand

Commit Message

gmingchen(ι™ˆδΎ›ζ˜Ž) Feb. 20, 2021, 9:13 a.m. UTC
From: Gongming Chen <gmingchen@tencent.com>

This patch merges ipv4 addresses with wildcard masks, and replaces this
ipv4 addresses with the combined ip/mask. This will greatly reduce the
entries in the ovs security group flow table, especially when the host
size is large.

Analysis in the simplest scenario, a network 1.1.1.0/24 network,create 253
ports(1.1.1.2-1.1.1.254).
Only focus on the number of ip addresses, the original 253 addresses will
be combined into 13 addresses.
1.1.1.2/31
1.1.1.4/30
1.1.1.8/29
1.1.1.16/28
1.1.1.32/27
1.1.1.64/26
1.1.1.128/26
1.1.1.192/27
1.1.1.224/28
1.1.1.240/29
1.1.1.248/30
1.1.1.252/31
1.1.1.254

Some scenes are similar to the following:
    1.1.1.2, 1.1.1.6
After the combine:
    1.1.1.2/255.255.255.251
You can use ovn-match-ip utility to match ip.
such as:
    ovs-ofctl dump-flows br-int | ovn-match-ip 1.1.1.6
    1.1.1.2/255.255.255.251 will show.

Simple description of the algorithm.
There are two situations
1. Combine once
such as:
    1.1.1.0 1.1.1.1 1.0.1.0 1.0.1.1
    Combined into: 1.1.1.0/31, 1.0.1.0/31
2. Combine multiple times
    1.1.1.0 1.1.1.1 1.0.1.0 1.0.1.1
    Combined into: 1.0.1.0/255.254.255.254

Considering the actual scene and simplicity, the first case is used to
combine once.

...00...
...01...
...10...
...11...
"..." means the same value omitted.
Obviously, the above value can be expressed as ...00.../11100111. This
continuous interval that can be represented by one or several wildcard
masks is called a segment.
Only if all 2<<n values from the minimum value 00...(n) to 11...(n)
exist, can they be combined into 00...(n)/00...( n)

First sort all the values by size. Iterate through each value.
1. Find a new segment, where two values differ only by 1 bit, such as
...0... and ...1...
    diff = ip_next ^ ip
    if (diff & (diff-1)) == 0
        new_segment = true
The first non-zero place in the high direction of ip is the end of the
segment(segment_end).
For example...100... and...101..., the segment_end is ...111...

2. Count the number of consecutive and less than continuous_size in the
segment.
    diff = ip_next - ip
    if (diff & (diff-1)) == 0 && ip_next <= segment_end
        continuous_size++

3. Combine different ip intervals in the segment according to
continuous_size.
In continuous_size, from the highest bit of 1 to the lowest bit of 1, in
the order of segment start, each bit that is 1 is a different ip interval
that can be combined with a wildcard mask.
For example, 000, 001, 010:
    continuous_size: 3 (binary 11), segment_start: 000
    mask: ~(1 << 1 - 1) = 110; ~(1 << 0 - 1) = 111;
    Combined to: 000/110, 010/111

4. The ip that cannot be recorded in a segment will not be combined.

Signed-off-by: Gongming Chen <gmingchen@tencent.com>
---
 debian/ovn-common.install |   1 +
 lib/expr.c                | 219 ++++++++++++++++++++++++++++++++++++++
 rhel/ovn-fedora.spec.in   |   1 +
 tests/ovn.at              | 136 +++++++++++------------
 tests/test-ovn.c          |   9 ++
 utilities/automake.mk     |   5 +-
 utilities/ovn-match-ip.in |  78 ++++++++++++++
 7 files changed, 382 insertions(+), 67 deletions(-)
 create mode 100755 utilities/ovn-match-ip.in
diff mbox series

Patch

diff --git a/debian/ovn-common.install b/debian/ovn-common.install
index 8e5915724..0095df918 100644
--- a/debian/ovn-common.install
+++ b/debian/ovn-common.install
@@ -5,6 +5,7 @@  usr/bin/ovn-ic-nbctl
 usr/bin/ovn-ic-sbctl
 usr/bin/ovn-trace
 usr/bin/ovn-detrace
+usr/bin/ovn-match-ip
 usr/share/ovn/scripts/ovn-ctl
 usr/share/ovn/scripts/ovndb-servers.ocf
 usr/share/ovn/scripts/ovn-lib
diff --git a/lib/expr.c b/lib/expr.c
index f061a8fbe..0a7203817 100644
--- a/lib/expr.c
+++ b/lib/expr.c
@@ -1060,6 +1060,200 @@  expr_constant_set_destroy(struct expr_constant_set *cs)
     }
 }
 
+struct ip_in
+{
+    uint32_t *ip;
+    size_t size;
+};
+
+struct ip_out_entry
+{
+    uint32_t ip;
+    uint32_t mask;
+    bool masked;
+};
+
+struct ip_out
+{
+    struct ip_out_entry *entries;
+    size_t used;
+    size_t size;
+};
+
+static int
+compare_mask_ip(const void *a, const void *b)
+{
+    uint32_t a_ = *(uint32_t *)a;
+    uint32_t b_ = *(uint32_t *)b;
+
+    return a_ < b_ ? -1 : a_ > b_;
+}
+
+/* Function to check ip return data and xrealloc. */
+static void
+check_realloc_ip_out(struct ip_out *ip_out_data){
+    if (ip_out_data->used >= ip_out_data->size) {
+        ip_out_data->entries = x2nrealloc(ip_out_data->entries,
+                                    &ip_out_data->size,
+                                    sizeof *ip_out_data->entries);
+    }
+}
+
+/* Simple description of the algorithm.
+ * There are two situations
+ * 1. Combine once
+ * such as:
+ *     1.1.1.0 1.1.1.1 1.0.1.0 1.0.1.1
+ *     Combined into: 1.1.1.0/31, 1.0.1.0/31
+ * 2. Combine multiple times
+ *     1.1.1.0 1.1.1.1 1.0.1.0 1.0.1.1
+ *     Combined into: 1.0.1.0/255.254.255.254
+ *
+ * Considering the actual scene and simplicity, the first case is used to
+ * combine once.
+ *
+ * ...00...
+ * ...01...
+ * ...10...
+ * ...11...
+ * "..." means the same value omitted.
+ * Obviously, the above value can be expressed as ...00.../11100111. This
+ * continuous interval that can be represented by one or several wildcard
+ * masks is called a segment.
+ * Only if all 2<<n values from the minimum value 00...(n) to 11...(n)
+ * exist, can they be combined into 00...(n)/00...( n)
+ *
+ * First sort all the values by size. Iterate through each value.
+ * 1. Find a new segment, where two values differ only by 1 bit, such as
+ * ...0... and ...1...
+ *     diff = ip_next ^ ip
+ *     if (diff & (diff-1)) == 0
+ *         new_segment = true
+ * The first non-zero place in the high direction of ip is the end of the
+ * segment(segment_end).
+ * For example...100... and...101..., the segment_end is ...111...
+ *
+ * 2. Count the number of consecutive and less than continuous_size in the
+ * segment.
+ *     diff = ip_next - ip
+ *     if (diff & (diff-1)) == 0 && ip_next <= segment_end
+ *         continuous_size++
+ *
+ * 3. Combine different ip intervals in the segment according to
+ * continuous_size.
+ * In continuous_size, from the highest bit of 1 to the lowest bit of 1, in
+ * the order of segment start, each bit that is 1 is a different ip interval
+ * that can be combined with a wildcard mask.
+ * For example, 000, 001, 010:
+ *     continuous_size: 3 (binary 11), segment_start: 000
+ *     mask: ~(1 << 1 - 1) = 110; ~(1 << 0 - 1) = 111;
+ *     Combined to: 000/110, 010/111
+ *
+ * 4. The ip that cannot be recorded in a segment will not be combined. */
+static void
+combine_ipv4_in_mask(struct ip_in *ip_in_data, struct ip_out *ip_out_data){
+    bool recording = false;
+    uint32_t i, diff, connect, start, end, continuous_size, mask_base;
+
+    start = 0;
+    continuous_size = 0;
+    mask_base = 0;
+    end = 0;
+
+    qsort(ip_in_data->ip, ip_in_data->size, sizeof(uint32_t),
+          compare_mask_ip);
+    memset(ip_out_data, 0, sizeof(struct ip_out));
+
+    for (i = 0; i < ip_in_data->size; i++) {
+        if (i + 1 >= ip_in_data->size) {
+            if (!recording) {
+                goto end_when_not_recording;
+            } else {
+                goto end_when_recording;
+            }
+        }
+        /* Not recording in a segment.
+         * Record a new segment or not combine. */
+        if (!recording) {
+            connect = ip_in_data->ip[i + 1] ^ ip_in_data->ip[i];
+            /* Only one bit different. */
+            if ((connect & (connect - 1)) == 0) {
+                recording = true;
+                start = ip_in_data->ip[i];
+                continuous_size = 2;
+                mask_base = connect;
+
+                int j = 0;
+                end = start;
+                /* The first non-zero place in the high direction is
+                 * the end of the segment. */
+                while (j < 32 && ((start & (mask_base << j)) == 0)) {
+                    end |= (mask_base << j);
+                    j++;
+                }
+
+                continue;
+            /* Different segments and different bit, dnot combine. */
+            } else {
+end_when_not_recording:
+                check_realloc_ip_out(ip_out_data);
+
+                ip_out_data->entries[ip_out_data->used].ip =
+                    ip_in_data->ip[i];
+                ip_out_data->entries[ip_out_data->used].masked = false;
+                ip_out_data->used++;
+
+                continue;
+            }
+        /* Recording in the current segment. */
+        } else {
+            diff = ip_in_data->ip[i + 1] - ip_in_data->ip[i];
+            /* Ignore equal node. */
+            if (diff == 0) {
+                continue;
+            }
+            /* Stop recording and combine, or continue recording. */
+            if (((diff & (diff - 1)) != 0)
+                || (ip_in_data->ip[i + 1] > end)) {
+end_when_recording:
+                recording = false;
+                while (continuous_size) {
+                    check_realloc_ip_out(ip_out_data);
+
+                    int segment_power, pow_base;
+                    if (continuous_size == 0) {
+                        segment_power = 0;
+                    } else {
+                        segment_power = 31 - clz32(continuous_size);
+                    }
+
+                    if (mask_base == 0) {
+                        pow_base = 0;
+                    } else {
+                        pow_base = 31 - clz32(mask_base);
+                    }
+
+                    ip_out_data->entries[ip_out_data->used].mask =
+                        ~(((1 << segment_power) - 1) << pow_base);
+                    ip_out_data->entries[ip_out_data->used].ip =
+                        ip_out_data->entries[ip_out_data->used].mask
+                        & start;
+                    ip_out_data->entries[ip_out_data->used].masked = true;
+                    ip_out_data->used++;
+
+                    continuous_size &= (~(1 << segment_power));
+                    start = ip_out_data->entries[ip_out_data->used - 1].ip
+                            + (1 << (segment_power + pow_base));
+                }
+            } else {
+                continuous_size++;
+            }
+
+            continue;
+        }
+    }
+}
+
 /* Adds an constant set named 'name' to 'const_sets', replacing any existing
  * constant set entry with the given name. */
 void
@@ -1074,6 +1268,11 @@  expr_const_sets_add(struct shash *const_sets, const char *name,
     cs->in_curlies = true;
     cs->n_values = 0;
     cs->values = xmalloc(n_values * sizeof *cs->values);
+    struct ip_out ip_out_data;
+    struct ip_in ip_in_data;
+    ip_in_data.ip = xmalloc(n_values * sizeof(uint32_t));
+    ip_in_data.size = 0;
+
     if (convert_to_integer) {
         cs->type = EXPR_C_INTEGER;
         for (size_t i = 0; i < n_values; i++) {
@@ -1086,6 +1285,9 @@  expr_const_sets_add(struct shash *const_sets, const char *name,
                 && lex.token.type != LEX_T_MASKED_INTEGER) {
                 VLOG_WARN("Invalid constant set entry: '%s', token type: %d",
                           values[i], lex.token.type);
+            } else if (lex.token.type == LEX_T_INTEGER
+                       && lex.token.format == LEX_F_IPV4) {
+                ip_in_data.ip[ip_in_data.size++] = ntohl(lex.token.value.ipv4);
             } else {
                 union expr_constant *c = &cs->values[cs->n_values++];
                 c->value = lex.token.value;
@@ -1105,6 +1307,23 @@  expr_const_sets_add(struct shash *const_sets, const char *name,
         }
     }
 
+    if (ip_in_data.size > 0) {
+        combine_ipv4_in_mask(&ip_in_data, &ip_out_data);
+        for (size_t i = 0; i < ip_out_data.used; ++i) {
+            union expr_constant *c = &cs->values[cs->n_values++];
+            memset(&c->value, 0, sizeof c->value);
+            memset(&c->mask, 0, sizeof c->mask);
+            c->value.ipv4 = htonl(ip_out_data.entries[i].ip);
+            c->format = LEX_F_IPV4;
+            c->masked = ip_out_data.entries[i].masked;
+            if (c->masked) {
+                c->mask.ipv4 = htonl(ip_out_data.entries[i].mask);
+            }
+        }
+        free(ip_out_data.entries);
+    }
+
+    free(ip_in_data.ip);
     shash_add(const_sets, name, cs);
 }
 
diff --git a/rhel/ovn-fedora.spec.in b/rhel/ovn-fedora.spec.in
index 6716dd0d2..1a0abff06 100644
--- a/rhel/ovn-fedora.spec.in
+++ b/rhel/ovn-fedora.spec.in
@@ -455,6 +455,7 @@  fi
 %{_bindir}/ovn-sbctl
 %{_bindir}/ovn-trace
 %{_bindir}/ovn-detrace
+%{_bindir}/ovn-match-ip
 %{_bindir}/ovn-appctl
 %{_bindir}/ovn-ic-nbctl
 %{_bindir}/ovn-ic-sbctl
diff --git a/tests/ovn.at b/tests/ovn.at
index 3d027c414..dada32190 100644
--- a/tests/ovn.at
+++ b/tests/ovn.at
@@ -618,20 +618,32 @@  ip,nw_src=10.0.0.3
 ])
 AT_CHECK([expr_to_flow 'ip4.src == $set1'], [0], [dnl
 ip,nw_src=10.0.0.1
-ip,nw_src=10.0.0.2
-ip,nw_src=10.0.0.3
+ip,nw_src=10.0.0.2/31
+])
+AT_CHECK([expr_to_flow 'ip4.src == $set5'], [0], [dnl
+ip,nw_src=1.1.1.128/26
+ip,nw_src=1.1.1.16/28
+ip,nw_src=1.1.1.192/27
+ip,nw_src=1.1.1.2/31
+ip,nw_src=1.1.1.224/28
+ip,nw_src=1.1.1.240/29
+ip,nw_src=1.1.1.248/30
+ip,nw_src=1.1.1.252/31
+ip,nw_src=1.1.1.254
+ip,nw_src=1.1.1.32/27
+ip,nw_src=1.1.1.4/30
+ip,nw_src=1.1.1.64/26
+ip,nw_src=1.1.1.8/29
 ])
 AT_CHECK([expr_to_flow 'ip4.src == {1.2.3.4, $set1}'], [0], [dnl
 ip,nw_src=1.2.3.4
 ip,nw_src=10.0.0.1
-ip,nw_src=10.0.0.2
-ip,nw_src=10.0.0.3
+ip,nw_src=10.0.0.2/31
 ])
 AT_CHECK([expr_to_flow 'ip4.src == {1.2.0.0/20, 5.5.5.0/24, $set1}'], [0], [dnl
 ip,nw_src=1.2.0.0/20
 ip,nw_src=10.0.0.1
-ip,nw_src=10.0.0.2
-ip,nw_src=10.0.0.3
+ip,nw_src=10.0.0.2/31
 ip,nw_src=5.5.5.0/24
 ])
 AT_CHECK([expr_to_flow 'ip6.src == {::1, ::2, ::3}'], [0], [dnl
@@ -13580,23 +13592,20 @@  cat 2.expected > expout
 $PYTHON "$ovs_srcdir/utilities/ovs-pcap.in" hv1/vif2-tx.pcap > 2.packets
 AT_CHECK([cat 2.packets], [0], [expout])
 
-# There should be total of 9 flows present with conjunction action and 2 flows
+# There should be total of 6 flows present with conjunction action and 2 flows
 # with conj match. Eg.
-# table=44, priority=2001,conj_id=2,metadata=0x1 actions=resubmit(,45)
-# table=44, priority=2001,conj_id=3,metadata=0x1 actions=drop
-# priority=2001,ip,metadata=0x1,nw_dst=10.0.0.6 actions=conjunction(2,2/2)
-# priority=2001,ip,metadata=0x1,nw_dst=10.0.0.4 actions=conjunction(2,2/2)
-# priority=2001,ip,metadata=0x1,nw_dst=10.0.0.5 actions=conjunction(2,2/2)
-# priority=2001,ip,metadata=0x1,nw_dst=10.0.0.7 actions=conjunction(3,2/2)
-# priority=2001,ip,metadata=0x1,nw_dst=10.0.0.9 actions=conjunction(3,2/2)
-# priority=2001,ip,metadata=0x1,nw_dst=10.0.0.8 actions=conjunction(3,2/2)
-# priority=2001,ip,metadata=0x1,nw_src=10.0.0.6 actions=conjunction(2,1/2),conjunction(3,1/2)
-# priority=2001,ip,metadata=0x1,nw_src=10.0.0.4 actions=conjunction(2,1/2),conjunction(3,1/2)
-# priority=2001,ip,metadata=0x1,nw_src=10.0.0.5 actions=conjunction(2,1/2),conjunction(3,1/2)
-
-OVS_WAIT_UNTIL([test 9 = `as hv1 ovs-ofctl dump-flows br-int | \
+#table=45, n_packets=1, n_bytes=42, idle_age=211, priority=2001,conj_id=2,ip,metadata=0x1 actions=resubmit(,46)
+#table=45, n_packets=0, n_bytes=0, idle_age=211, priority=2001,conj_id=3,ip,metadata=0x1 actions=drop
+#priority=2001,ip,metadata=0x1,nw_src=10.0.0.6 actions=conjunction(2,2/2),conjunction(3,2/2)
+#priority=2001,ip,metadata=0x1,nw_src=10.0.0.4/31 actions=conjunction(2,2/2),conjunction(3,2/2)
+#priority=2001,ip,metadata=0x1,nw_dst=10.0.0.4/31 actions=conjunction(2,1/2)
+#priority=2001,ip,metadata=0x1,nw_dst=10.0.0.6 actions=conjunction(2,1/2)
+#priority=2001,ip,metadata=0x1,nw_dst=10.0.0.7 actions=conjunction(3,1/2)
+#priority=2001,ip,metadata=0x1,nw_dst=10.0.0.8/31 actions=conjunction(3,1/2)
+
+OVS_WAIT_UNTIL([test 6 = `as hv1 ovs-ofctl dump-flows br-int | \
 grep conjunction | wc -l`])
-OVS_WAIT_UNTIL([test 3 = `as hv1 ovs-ofctl dump-flows br-int | \
+OVS_WAIT_UNTIL([test 2 = `as hv1 ovs-ofctl dump-flows br-int | \
 grep conjunction.*conjunction | wc -l`])
 OVS_WAIT_UNTIL([test 2 = `as hv1 ovs-ofctl dump-flows br-int | \
 grep conj_id | wc -l`])
@@ -13623,18 +13632,16 @@  AT_CHECK([cat 2.packets], [0], [])
 # properly.
 # There should be total of 6 flows present with conjunction action and 1 flow
 # with conj match. Eg.
-# table=44, priority=2001,conj_id=3,metadata=0x1 actions=drop
-# priority=2001,ip,metadata=0x1,nw_dst=10.0.0.7 actions=conjunction(4,2/2)
-# priority=2001,ip,metadata=0x1,nw_dst=10.0.0.9 actions=conjunction(4,2/2)
-# priority=2001,ip,metadata=0x1,nw_dst=10.0.0.8 actions=conjunction(4,2/2)
-# priority=2001,ip,metadata=0x1,nw_src=10.0.0.6 actions=conjunction(4,1/2)
-# priority=2001,ip,metadata=0x1,nw_src=10.0.0.4 actions=conjunction(4,1/2)
-# priority=2001,ip,metadata=0x1,nw_src=10.0.0.5 actions=conjunction(4,1/2)
+# table=45, n_packets=1, n_bytes=42, idle_age=34, priority=2001,conj_id=3,ip,metadata=0x1 actions=drop
+# priority=2001,ip,metadata=0x1,nw_src=10.0.0.6 actions=conjunction(3,2/2)
+# priority=2001,ip,metadata=0x1,nw_src=10.0.0.4/31 actions=conjunction(3,2/2)
+# priority=2001,ip,metadata=0x1,nw_dst=10.0.0.8/31 actions=conjunction(3,1/2)
+# priority=2001,ip,metadata=0x1,nw_dst=10.0.0.7 actions=conjunction(3,1/2)
 
 ovn-nbctl acl-del ls1 to-lport 1001 \
 'ip4 && ip4.src == $set1 && ip4.dst == $set1'
 
-OVS_WAIT_UNTIL([test 6 = `as hv1 ovs-ofctl dump-flows br-int | \
+OVS_WAIT_UNTIL([test 4 = `as hv1 ovs-ofctl dump-flows br-int | \
 grep conjunction | wc -l`])
 OVS_WAIT_UNTIL([test 0 = `as hv1 ovs-ofctl dump-flows br-int | \
 grep conjunction.*conjunction | wc -l`])
@@ -13648,43 +13655,40 @@  ovn-nbctl acl-add ls1 to-lport 1001 \
 ovn-nbctl acl-add ls1 to-lport 1001 \
 'ip4 && ip4.src == $set1 && ip4.dst == {10.0.0.9, 10.0.0.10}' drop
 
-# priority=2001,ip,metadata=0x1,nw_dst=10.0.0.8 actions=conjunction(4,1/2)
-# priority=2001,ip,metadata=0x1,nw_dst=10.0.0.7 actions=conjunction(4,1/2)
-# priority=2001,ip,metadata=0x1,nw_dst=10.0.0.4 actions=conjunction(5,1/2)
-# priority=2001,ip,metadata=0x1,nw_dst=10.0.0.5 actions=conjunction(5,1/2)
-# priority=2001,ip,metadata=0x1,nw_dst=10.0.0.6 actions=conjunction(5,1/2)
-# priority=2001,ip,metadata=0x1,nw_dst=10.0.0.9 actions=conjunction(4,1/2),conjunction(6,1/2)
-# priority=2001,ip,metadata=0x1,nw_dst=10.0.0.10 actions=conjunction(6,1/2)
-# priority=2001,ip,metadata=0x1,nw_src=10.0.0.5 actions=conjunction(4,2/2),conjunction(5,2/2),conjunction(6,2/2)
-# priority=2001,ip,metadata=0x1,nw_src=10.0.0.4 actions=conjunction(4,2/2),conjunction(5,2/2),conjunction(6,2/2)
-# priority=2001,ip,metadata=0x1,nw_src=10.0.0.6 actions=conjunction(4,2/2),conjunction(5,2/2),conjunction(6,2/2)
-
-OVS_WAIT_UNTIL([test 10 = `as hv1 ovs-ofctl dump-flows br-int | \
+# priority=2001,ip,metadata=0x1,nw_dst=10.0.0.7 actions=conjunction(3,1/2)
+# priority=2001,ip,metadata=0x1,nw_dst=10.0.0.8/31 actions=conjunction(3,1/2)
+# priority=2001,ip,metadata=0x1,nw_dst=10.0.0.4/31 actions=conjunction(4,1/2)
+# priority=2001,ip,metadata=0x1,nw_dst=10.0.0.6 actions=conjunction(4,1/2)
+# priority=2001,ip,metadata=0x1,nw_dst=10.0.0.9 actions=conjunction(5,1/2)
+# priority=2001,ip,metadata=0x1,nw_dst=10.0.0.10 actions=conjunction(5,1/2)
+# priority=2001,ip,metadata=0x1,nw_src=10.0.0.4/31 actions=conjunction(3,2/2),conjunction(4,2/2),conjunction(5,2/2)
+# priority=2001,ip,metadata=0x1,nw_src=10.0.0.6 actions=conjunction(3,2/2),conjunction(4,2/2),conjunction(5,2/2)
+
+OVS_WAIT_UNTIL([test 8 = `as hv1 ovs-ofctl dump-flows br-int | \
 grep conjunction | wc -l`])
-OVS_WAIT_UNTIL([test 4 = `as hv1 ovs-ofctl dump-flows br-int | \
+OVS_WAIT_UNTIL([test 2 = `as hv1 ovs-ofctl dump-flows br-int | \
 grep conjunction.*conjunction | wc -l`])
-OVS_WAIT_UNTIL([test 3 = `as hv1 ovs-ofctl dump-flows br-int | \
+OVS_WAIT_UNTIL([test 2 = `as hv1 ovs-ofctl dump-flows br-int | \
 grep conjunction.*conjunction.*conjunction | wc -l`])
 
 # Remove 10.0.0.7 from address set2. All flows should be updated properly.
 ovn-nbctl set Address_Set set2 \
 addresses=\"10.0.0.8\",\"10.0.0.9\"
 
-# priority=2001,ip,metadata=0x1,nw_dst=10.0.0.4 actions=conjunction(9,1/2)
-# priority=2001,ip,metadata=0x1,nw_dst=10.0.0.10 actions=conjunction(7,1/2)
-# priority=2001,ip,metadata=0x1,nw_dst=10.0.0.8 actions=conjunction(8,1/2)
-# priority=2001,ip,metadata=0x1,nw_dst=10.0.0.5 actions=conjunction(9,1/2)
-# priority=2001,ip,metadata=0x1,nw_dst=10.0.0.9 actions=conjunction(7,1/2),conjunction(8,1/2)
-# priority=2001,ip,metadata=0x1,nw_dst=10.0.0.6 actions=conjunction(9,1/2)
-# priority=2001,ip,metadata=0x1,nw_src=10.0.0.5 actions=conjunction(7,2/2),conjunction(8,2/2),conjunction(9,2/2)
-# priority=2001,ip,metadata=0x1,nw_src=10.0.0.6 actions=conjunction(7,2/2),conjunction(8,2/2),conjunction(9,2/2)
-# priority=2001,ip,metadata=0x1,nw_src=10.0.0.4 actions=conjunction(7,2/2),conjunction(8,2/2),conjunction(9,2/2)
-
-OVS_WAIT_UNTIL([test 9 = `as hv1 ovs-ofctl dump-flows br-int | \
+# priority=2001,ip,metadata=0x1,nw_src=10.0.0.4/31,nw_dst=10.0.0.8/31 actions=drop
+# priority=2001,ip,metadata=0x1,nw_src=10.0.0.6,nw_dst=10.0.0.8/31 actions=drop
+# priority=2001,ip,metadata=0x1,nw_dst=10.0.0.4/31 actions=conjunction(4,1/2)
+# priority=2001,ip,metadata=0x1,nw_dst=10.0.0.6 actions=conjunction(4,1/2)
+# priority=2001,ip,metadata=0x1,nw_dst=10.0.0.9 actions=conjunction(5,1/2)
+# priority=2001,ip,metadata=0x1,nw_dst=10.0.0.10 actions=conjunction(5,1/2)
+# priority=2001,ip,metadata=0x1,nw_src=10.0.0.6 actions=conjunction(5,2/2),conjunction(4,2/2)
+# priority=2001,ip,metadata=0x1,nw_src=10.0.0.4/31 actions=conjunction(5,2/2),conjunction(4,2/2)
+
+OVS_WAIT_UNTIL([test 6 = `as hv1 ovs-ofctl dump-flows br-int | \
 grep conjunction | wc -l`])
-OVS_WAIT_UNTIL([test 4 = `as hv1 ovs-ofctl dump-flows br-int | \
+OVS_WAIT_UNTIL([test 2 = `as hv1 ovs-ofctl dump-flows br-int | \
 grep conjunction.*conjunction | wc -l`])
-OVS_WAIT_UNTIL([test 3 = `as hv1 ovs-ofctl dump-flows br-int | \
+OVS_WAIT_UNTIL([test 0 = `as hv1 ovs-ofctl dump-flows br-int | \
 grep conjunction.*conjunction.*conjunction | wc -l`])
 
 # Remove an ACL again
@@ -13693,16 +13697,16 @@  ovn-nbctl acl-del ls1 to-lport 1001 \
 
 wait_for_ports_up
 ovn-nbctl --wait=hv sync
-# priority=2001,ip,metadata=0x1,nw_dst=10.0.0.10 actions=conjunction(10,1/2)
-# priority=2001,ip,metadata=0x1,nw_dst=10.0.0.8 actions=conjunction(11,1/2)
-# priority=2001,ip,metadata=0x1,nw_dst=10.0.0.9 actions=conjunction(10,1/2),conjunction(11,1/2)
-# priority=2001,ip,metadata=0x1,nw_src=10.0.0.5 actions=conjunction(10,2/2),conjunction(11,2/2)
-# priority=2001,ip,metadata=0x1,nw_src=10.0.0.6 actions=conjunction(10,2/2),conjunction(11,2/2)
-# priority=2001,ip,metadata=0x1,nw_src=10.0.0.4 actions=conjunction(10,2/2),conjunction(11,2/2)
+# priority=2001,ip,metadata=0x1,nw_src=10.0.0.6,nw_dst=10.0.0.8/31 actions=drop
+# priority=2001,ip,metadata=0x1,nw_src=10.0.0.4/31,nw_dst=10.0.0.8/31 actions=drop
+# priority=2001,ip,metadata=0x1,nw_src=10.0.0.6 actions=conjunction(5,2/2)
+# priority=2001,ip,metadata=0x1,nw_src=10.0.0.4/31 actions=conjunction(5,2/2)
+# priority=2001,ip,metadata=0x1,nw_dst=10.0.0.10 actions=conjunction(5,1/2)
+# priority=2001,ip,metadata=0x1,nw_dst=10.0.0.9 actions=conjunction(5,1/2)
 
-OVS_WAIT_UNTIL([test 6 = `as hv1 ovs-ofctl dump-flows br-int | \
-grep conjunction | wc -l`])
 OVS_WAIT_UNTIL([test 4 = `as hv1 ovs-ofctl dump-flows br-int | \
+grep conjunction | wc -l`])
+OVS_WAIT_UNTIL([test 0 = `as hv1 ovs-ofctl dump-flows br-int | \
 grep conjunction.*conjunction | wc -l`])
 OVS_WAIT_UNTIL([test 0 = `as hv1 ovs-ofctl dump-flows br-int | \
 grep conjunction.*conjunction.*conjunction | wc -l`])
@@ -15373,11 +15377,11 @@  for i in 1 2 3; do
 
     # Update address set as1
     ovn-nbctl --wait=hv set addr as1 addresses="10.1.2.10 10.1.2.11"
-    AT_CHECK([ovs-ofctl dump-flows br-int | grep "10.1.2.11"], [0], [ignore])
+    AT_CHECK([ovs-ofctl dump-flows br-int | grep "10.1.2.10/31"], [0], [ignore])
 
     # Update address set as2
     ovn-nbctl --wait=hv set addr as2 addresses="10.1.2.12 10.1.2.13"
-    AT_CHECK([ovs-ofctl dump-flows br-int | grep "10.1.2.12"], [0], [ignore])
+    AT_CHECK([ovs-ofctl dump-flows br-int | grep "10.1.2.12/31"], [0], [ignore])
 
     # Add another ACL referencing as1
     n_flows_before=`ovs-ofctl dump-flows br-int | grep "10.1.2.10" | wc -l`
diff --git a/tests/test-ovn.c b/tests/test-ovn.c
index 9bd13a037..e15ae03c7 100644
--- a/tests/test-ovn.c
+++ b/tests/test-ovn.c
@@ -227,10 +227,19 @@  create_addr_sets(struct shash *addr_sets)
     };
     static const char *const addrs4[] = { NULL };
 
+    static const char *addrs5[253];
+    static char addrs5_[253][20];
+    for (int i = 0, ip_num = 2; i < 253; i++, ip_num++) {
+        sprintf(addrs5_[i], "1.1.1.%d", ip_num);
+        addrs5[i] = addrs5_[i];
+    }
+
     expr_const_sets_add(addr_sets, "set1", addrs1, 3, true);
     expr_const_sets_add(addr_sets, "set2", addrs2, 3, true);
     expr_const_sets_add(addr_sets, "set3", addrs3, 3, true);
     expr_const_sets_add(addr_sets, "set4", addrs4, 0, true);
+    expr_const_sets_add(addr_sets, "set5", (const char *const *)addrs5,
+                        253, true);
 }
 
 static void
diff --git a/utilities/automake.mk b/utilities/automake.mk
index c4a6d248c..af572c7a0 100644
--- a/utilities/automake.mk
+++ b/utilities/automake.mk
@@ -21,7 +21,8 @@  MAN_ROOTS += \
 bin_SCRIPTS += \
     utilities/ovn-docker-overlay-driver \
     utilities/ovn-docker-underlay-driver \
-    utilities/ovn-detrace
+    utilities/ovn-detrace \
+    utilities/ovn-match-ip
 
 EXTRA_DIST += \
     utilities/ovn-ctl \
@@ -35,6 +36,7 @@  EXTRA_DIST += \
     utilities/ovn-appctl.8.xml \
     utilities/ovn-trace.8.xml \
     utilities/ovn-detrace.in \
+    utilities/ovn-match-ip.in \
     utilities/ovndb-servers.ocf \
     utilities/checkpatch.py \
     utilities/docker/Makefile \
@@ -60,6 +62,7 @@  CLEANFILES += \
     utilities/ovn-trace.8 \
     utilities/ovn-detrace.1 \
     utilities/ovn-detrace \
+    utilities/ovn-match-ip \
     utilities/ovn-appctl.8 \
     utilities/ovn-appctl \
     utilities/ovn-sim
diff --git a/utilities/ovn-match-ip.in b/utilities/ovn-match-ip.in
new file mode 100755
index 000000000..af8124185
--- /dev/null
+++ b/utilities/ovn-match-ip.in
@@ -0,0 +1,78 @@ 
+#!/bin/bash
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at:
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+IPCALC_WILDCARD_RET=
+
+ipcalc_wildcard () {
+    ip=`echo $1 | awk -F '/' '{print $1}'`
+    ip_list=${ip//./ }
+    read -a ip_array <<< ${ip_list}
+    mask=`echo $1 | awk -F '/' '{print $2}'`
+    mask_list=${mask//./ }
+    read -a mask_array <<< ${mask_list}
+    ip_0=$((${ip_array[0]} & ${mask_array[0]}))
+    ip_1=$((${ip_array[1]} & ${mask_array[1]}))
+    ip_2=$((${ip_array[2]} & ${mask_array[2]}))
+    ip_3=$((${ip_array[3]} & ${mask_array[3]}))
+    IPCALC_WILDCARD_RET="$ip_0.$ip_1.$ip_2.$ip_3"
+}
+
+for arg
+do
+    case $arg in
+        -h | --help)
+            cat <<EOF
+$0: A tool that can match ip wildcard mask similar to grep
+usage: $0 ip
+Search for ip/mask that can be matched in standard input.
+Example: echo ip 192.168.1.0/24 | $0 192.168.1.1
+Result: ip 192.168.1.0/24
+
+You might use this: ovs-ofctl dump-flows br-int | $0 192.168.1.1
+EOF
+            exit 0
+            ;;
+    esac
+done
+
+while read line
+do
+    ip=`echo $line | grep -oE '[0-9]+\.[0-9]+\.[0-9]+\.[0-9]+'`
+    if test "$ip" == "$1"; then
+        echo $line | grep --color $1
+        continue
+    fi
+
+    ip_mask=`echo $line | grep -oE '[0-9]+\.[0-9]+\.[0-9]+\.[0-9]+/[0-9]+\.[0-9]+\.[0-9]+\.[0-9]+'`
+    if test "$ip_mask" != ""; then
+        ipcalc_wildcard $ip_mask
+        ip_mask_ret=$IPCALC_WILDCARD_RET
+        match_ip_mask=`echo $ip_mask | sed 's/.*\//'$1'\//'`
+        ipcalc_wildcard $match_ip_mask
+        match_ip_mask_ret=$IPCALC_WILDCARD_RET
+        if test $ip_mask_ret == $match_ip_mask_ret; then
+            echo $line | grep --color $ip_mask
+        fi
+        continue
+    fi
+
+    ip_prefix=`echo $line | grep -oE '[0-9]+\.[0-9]+\.[0-9]+\.[0-9]+/[0-9]+'`
+    if test "$ip_prefix" != ""; then
+        match_ip_prefix=`echo $ip_prefix | sed 's/.*\//'$1'\//'`
+        if test `ipcalc -n $match_ip_prefix` == `ipcalc -n $ip_prefix`; then
+            echo $line | grep --color $ip_prefix
+        fi
+        continue
+    fi
+done