[ovs-dev] [PATCH ovn] Exclude inport and outport symbol tables from conjunction

nusiddiq at redhat.com nusiddiq at redhat.com
Fri Sep 13 20:49:19 UTC 2019


From: Numan Siddique <nusiddiq at redhat.com>

If there are multiple ACLs associated with a port group and they
match on a range of some field, then ovn-controller doesn't install
the flows properly and this results in broken ACL functionality.

For example, if there is a port group - pg1 with logical ports - [p1, p2]
and if there are below ACLs (only match condition is shown)

1 -  outport == @pg1 && ip4 && tcp.dst >= 500 && tcp.dst <= 501
2 -  outport == @pg1 && ip4 && tcp.dst >= 600 && tcp.dst <= 601

The first ACL will result in the below OF flows

1.  conj_id=1,tcp
2.  tcp,reg15=0x11: conjunction(1, 1/2)
3.  tcp,reg15=0x12: conjunction(1, 1/2)
5.  tcp,tp_dst=500: conjunction(1, 2/2)
6.  tcp,tp_dst=501: conjunction(1, 2/2)

The second ACL will result in the below OF flows
7.  conj_id=2,tcp
8.  tcp,reg15=0x11: conjunction(2, 1/2)
9.  tcp,reg15=0x12: conjunction(2, 1/2)
11. tcp,tp_dst=600: conjunction(2, 2/2)
12. tcp,tp_dst=601: conjunction(2, 3/2)

The OF flows (2) and (8) have the exact match but with different action.
This results in only one of the flows getting installed. The same goes
for the flows (3) and (9). And this completely breaks the ACL functionality
for such scenarios.

In order to fix this issue, this patch excludes the 'inport' and 'outport' symbols
from conjunction. With this patch we will have the below flows.

tcp,reg15=0x11,tp_dst=500
tcp,reg15=0x11,tp_dst=501
tcp,reg15=0x12,tp_dst=500
tcp,reg15=0x12,tp_dst=501
tcp,reg15=0x13,tp_dst=500
tcp,reg15=0x13,tp_dst=501
tcp,reg15=0x11,tp_dst=600
tcp,reg15=0x11,tp_dst=601
tcp,reg15=0x12,tp_dst=600
tcp,reg15=0x12,tp_dst=601
tcp,reg15=0x13,tp_dst=600
tcp,reg15=0x13,tp_dst=601

Signed-off-by: Numan Siddique <nusiddiq at redhat.com>
---
 lib/expr.c   |  2 +-
 tests/ovn.at | 26 ++++++++++++++++++++++++++
 2 files changed, 27 insertions(+), 1 deletion(-)

diff --git a/lib/expr.c b/lib/expr.c
index e4c650f7c..c0871e1e8 100644
--- a/lib/expr.c
+++ b/lib/expr.c
@@ -1499,7 +1499,7 @@ expr_symtab_add_string(struct shash *symtab, const char *name,
     const struct mf_field *field = mf_from_id(id);
     struct expr_symbol *symbol;
 
-    symbol = add_symbol(symtab, name, 0, prereqs, EXPR_L_NOMINAL, false,
+    symbol = add_symbol(symtab, name, 0, prereqs, EXPR_L_NOMINAL, true,
                         field->writable);
     symbol->field = field;
     return symbol;
diff --git a/tests/ovn.at b/tests/ovn.at
index 2a35b4e15..14d9f59b0 100644
--- a/tests/ovn.at
+++ b/tests/ovn.at
@@ -589,6 +589,24 @@ ip,reg14=0x6
 ipv6,reg14=0x5
 ipv6,reg14=0x6
 ])
+AT_CHECK([expr_to_flow 'inport == {"eth0", "eth1", "eth2"} && ip4 && tcp && tcp.dst == {500, 501}'], [0], [dnl
+tcp,reg14=0x5,tp_dst=500
+tcp,reg14=0x5,tp_dst=501
+tcp,reg14=0x6,tp_dst=500
+tcp,reg14=0x6,tp_dst=501
+])
+AT_CHECK([expr_to_flow 'outport == {"eth0", "eth1", "eth2"} && ip4 && tcp && tcp.src == {400, 401} && tcp.dst == {500, 501}'], [0], [dnl
+conj_id=1,tcp,reg15=0x5
+conj_id=2,tcp,reg15=0x6
+tcp,reg15=0x5,tp_dst=500: conjunction(1, 0/2)
+tcp,reg15=0x5,tp_dst=501: conjunction(1, 0/2)
+tcp,reg15=0x5,tp_src=400: conjunction(1, 1/2)
+tcp,reg15=0x5,tp_src=401: conjunction(1, 1/2)
+tcp,reg15=0x6,tp_dst=500: conjunction(2, 0/2)
+tcp,reg15=0x6,tp_dst=501: conjunction(2, 0/2)
+tcp,reg15=0x6,tp_src=400: conjunction(2, 1/2)
+tcp,reg15=0x6,tp_src=401: conjunction(2, 1/2)
+])
 AT_CHECK([expr_to_flow 'inport == "eth0" && inport == "eth1"'], [0], [dnl
 (no flows)
 ])
@@ -693,6 +711,14 @@ reg15=0x11
 reg15=0x12
 reg15=0x13
 ])
+AT_CHECK([expr_to_flow 'outport == @pg1 && ip4.src == {10.0.0.4, 10.0.0.5}'], [0], [dnl
+ip,reg15=0x11,nw_src=10.0.0.4
+ip,reg15=0x11,nw_src=10.0.0.5
+ip,reg15=0x12,nw_src=10.0.0.4
+ip,reg15=0x12,nw_src=10.0.0.5
+ip,reg15=0x13,nw_src=10.0.0.4
+ip,reg15=0x13,nw_src=10.0.0.5
+])
 AT_CHECK([expr_to_flow 'outport == {@pg_empty}'], [0], [dnl
 (no flows)
 ])
-- 
2.21.0



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