pbrd: Fix PBR handling for last rule deletion

[routingrocks]

Issue:
Previously, the PBR common was updated for every rule update or deletion

example:
let say we have three rule 11, 12, 13 and if we are removing rule 12. in the current code we are making the entire map "valid" to false.

pbr-map MAP1 seq 11
match src-ip 90.1.1.2/32
set nexthop 20.1.1.2 swp1

pbr-map MAP1 seq 12
match src-ip 90.1.1.3/32
set nexthop 20.1.1.2 swp1

pbr-map MAP1 seq 13
match src-ip 90.1.1.4/32
set nexthop 20.1.1.2 swp1

no pbr-map MAP1 seq 12 ==> turns whole map valid to false.

r1(config)# end
r1# show pbr map
pbr-map MAP1 valid: no
Seq: 11 rule: 310
Installed: yes Reason: Valid
SRC IP Match: 90.1.1.2/32
nexthop 20.1.1.2 swp1
Installed: yes Tableid: 10002
Seq: 13 rule: 312
Installed: yes Reason: Valid
SRC IP Match: 90.1.1.4/32
nexthop 20.1.1.2 swp1
Installed: yes Tableid: 10004

Fix:
Now, the PBR common will only be updated when the last rule is being deleted. This change ensures that we only send a delete request to Zebra once, and only set the valid and installed flags to false when the last rule is deleted. This optimizes the handling of PBR rules and reduces unnecessary interactions with Zebra

Testing: UT in MR notes

Ticket: #

Signed-off-by: Rajesh Varatharaj [email protected]

[routingrocks]

UT Logs:

r1(config)# pbr-map MAP1 seq 11
r1(config-pbr-map)# match src-ip 90.1.1.2/32
r1(config-pbr-map)# set nexthop 20.1.1.2 swp1
r1(config-pbr-map)# exit
r1(config)# pbr-map MAP1 seq 12
r1(config-pbr-map)# match src-ip 90.1.1.3/32
r1(config-pbr-map)# set nexthop 20.1.1.2 swp1
r1(config-pbr-map)# exit
r1(config)# pbr-map MAP1 seq 13
r1(config-pbr-map)# match src-ip 90.1.1.4/32
r1(config-pbr-map)# set nexthop 20.1.1.2 swp1
r1(config-pbr-map)# exit
r1(config)# no pbr-map MAP1 seq 12
r1(config)# end
r1# show pbr map
  pbr-map MAP1 valid: yes
    Seq: 10 rule: 309
        Installed: yes Reason: Valid
        SRC IP Match: 90.1.1.1/32
        nexthop 20.1.1.2 swp1
          Installed: yes Tableid: 10000
    Seq: 11 rule: 310
        Installed: yes Reason: Valid
        SRC IP Match: 90.1.1.2/32
        nexthop 20.1.1.2 swp1
          Installed: yes Tableid: 10002
    Seq: 13 rule: 312
        Installed: yes Reason: Valid
        SRC IP Match: 90.1.1.4/32
        nexthop 20.1.1.2 swp1
          Installed: yes Tableid: 10004
  pbr-map MAP2 valid: yes
    Seq: 20 rule: 319
        Installed: yes Reason: Valid
        SRC IP Match: 90.1.1.2/32
        nexthop 20.1.1.2 swp1
          Installed: yes Tableid: 10001

[chiragshah6]

Good finding!

[ton31337]

@Mergifyio backport stable/9.1 stable/9.0 stable/8.5

[mergify]

backport stable/9.1 stable/9.0 stable/8.5

✅ Backports have been created

• #15228 pbrd: Fix PBR handling for last rule deletion (backport #15206) has been created for branch stable/9.1
• #15229 pbrd: Fix PBR handling for last rule deletion (backport #15206) has been created for branch stable/9.0
• #15230 pbrd: Fix PBR handling for last rule deletion (backport #15206) has been created for branch stable/8.5

[ton31337]

LGTM