bgpd: move auto config flag from bgp to srv6 unicast policy

[lsang96]

No description provided.

[greptile-apps]

Greptile Summary

This PR refactors the SRv6 unicast auto-mode flag from BGP_CONFIG_SRV6_UNICAST_SID_AUTO stored in bgp->af_flags[afi][SAFI_UNICAST] to a new SRV6_POLICY_FLAG_SID_AUTO bit in bgp->srv6_unicast[afi].flags, consolidating SRv6 unicast policy state into struct srv6_policy. All four changed files are updated consistently and no references to the old macro remain.

Confidence Score: 5/5

Safe to merge — clean, mechanical refactoring with no remaining references to the old flag and the previously flagged P0 issue fully resolved.

All occurrences of BGP_CONFIG_SRV6_UNICAST_SID_AUTO have been migrated consistently across every consumer. The previously raised P0 concern (is_srv6_unicast_enabled reading from the stale location) is fixed. No remaining P0/P1 findings.

No files require special attention.

Important Files Changed

Filename	Overview
bgpd/bgpd.h	Adds SRV6_POLICY_FLAG_SID_AUTO (1 << 1) to struct srv6_policy and removes the now-superseded BGP_CONFIG_SRV6_UNICAST_SID_AUTO (1 << 12) from the top-level bgp flags.
bgpd/bgp_srv6.h	Fixes is_srv6_unicast_enabled() to read the auto-mode flag from bgp->srv6_unicast[afi].flags instead of the now-removed bgp->af_flags location — resolves the previously raised P0 issue.
bgpd/bgp_srv6.c	Updates all SET/UNSET/CHECK_FLAG calls for the auto-mode flag to use the new srv6_unicast[afi].flags field; removes the now-unused local safi variable.
bgpd/bgp_vty.c	Migrates all VTY command and config-write references from the old af_flags-based flag to SRV6_POLICY_FLAG_SID_AUTO; removes the now-unused local safi variable in sid_export.

Flowchart

%%{init: {'theme': 'neutral'}}%%
flowchart TD
    A["sid export auto (VTY command)"] --> B["SET_FLAG(bgp->srv6_unicast[afi].flags,\nSRV6_POLICY_FLAG_SID_AUTO)"]
    B --> C["is_srv6_unicast_enabled(bgp, afi)"]
    C -->|"CHECK_FLAG srv6_unicast[afi].flags\nSRV6_POLICY_FLAG_SID_AUTO"| D["Returns true"]
    D --> E["bgp_srv6_unicast_ensure_afi_sid()"]
    E --> F["bgp_config_write_family()\nemits 'sid export auto'"]
    G["no sid export / delete"] --> H["UNSET_FLAG(bgp->srv6_unicast[afi].flags,\nSRV6_POLICY_FLAG_SID_AUTO)"]
    H --> I["bgp_srv6_unicast_delete()"]

Loading

_{Reviews (2): Last reviewed commit: "bgpd: move auto config flag from bgp to ..." | Re-trigger Greptile}

[lsang96]

@greptile review