[action] [PR:26617] [bgpcfgd]: Validate aggregate address prefix and reject prefixes with host bits set#2278
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#### Why I did it
When an invalid aggregate address prefix (e.g., 10.100.0.1/24 with host bits set) is configured in CONFIG_DB, bgpcfgd silently accepts it and pushes invalid commands to FRR. This can cause unexpected BGP behavior. Adding prefix validation with a clear error log makes it easier to diagnose misconfiguration.
##### Work item tracking
- Microsoft ADO **(number only)**: 37506197
#### How I did it
Added a validate_prefix() function in managers_aggregate_address.py that uses Python's ipaddress.ip_network(prefix, strict=True) to verify the prefix is a valid network address (no host bits set).
Called validate_prefix() at the beginning of address_set_handler(). If validation fails, the handler logs an error (log_err) with the prefix and reason, and returns False to skip the invalid entry.
Added unit tests for validate_prefix() covering valid prefixes (e.g., 10.100.0.0/16, 2001:db8::/32, 0.0.0.0/0) and invalid prefixes with host bits set.
Added integration-style test test_host_bits_set_rejected verifying that address_set_handler rejects bad prefixes, does not push commands, and marks state as inactive.
#### How to verify it
All tests including test_validate_prefix and test_host_bits_set_rejected should pass.
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- [x] 202603
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#### Description for the changelog
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Add prefix validation in bgpcfgd aggregate address manager to reject prefixes with host bits set and log an error.
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Signed-off-by: Sonic Build Admin <sonicbld@microsoft.com>
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Original PR: sonic-net/sonic-buildimage#26617 |
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Why I did it
When an invalid aggregate address prefix (e.g., 10.100.0.1/24 with host bits set) is configured in CONFIG_DB, bgpcfgd silently accepts it and pushes invalid commands to FRR. This can cause unexpected BGP behavior. Adding prefix validation with a clear error log makes it easier to diagnose misconfiguration.
Work item tracking
How I did it
Added a validate_prefix() function in managers_aggregate_address.py that uses Python's ipaddress.ip_network(prefix, strict=True) to verify the prefix is a valid network address (no host bits set).
Called validate_prefix() at the beginning of address_set_handler(). If validation fails, the handler logs an error (log_err) with the prefix and reason, and returns False to skip the invalid entry.
Added unit tests for validate_prefix() covering valid prefixes (e.g., 10.100.0.0/16, 2001:db8::/32, 0.0.0.0/0) and invalid prefixes with host bits set.
Added integration-style test test_host_bits_set_rejected verifying that address_set_handler rejects bad prefixes, does not push commands, and marks state as inactive.
How to verify it
All tests including test_validate_prefix and test_host_bits_set_rejected should pass.
Which release branch to backport (provide reason below if selected)
Tested branch (Please provide the tested image version)
Description for the changelog
Add prefix validation in bgpcfgd aggregate address manager to reject prefixes with host bits set and log an error.
Link to config_db schema for YANG module changes
Signed-off-by: Sonic Build Admin sonicbld@microsoft.com
A picture of a cute animal (not mandatory but encouraged)