rsp2k/headscale
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity

types/node, mapper: strip own IPv4 from emission when node has disable-ipv4 cap

Browse source 
When a node carries the disable-ipv4 nodeAttr documented at
https://tailscale.com/docs/reference/troubleshooting/network-configuration/cgnat-conflicts,
SaaS stops sending the node's CGNAT IPv4 prefix in MapResponse. The
allocator keeps assigning IPv4 server-side; only the wire-shape
delivery is filtered. Subnet routes the node advertises -- including
IPv4 prefixes -- survive in AllowedIPs and PrimaryRoutes.

TailNode now drops Is4 prefixes from Addresses and from the node's
own /32 slot in AllowedIPs when selfPolicyCaps carries
disable-ipv4. Mapper.buildTailPeers passes each peer's policy
CapMap so the filter applies in viewer netmaps too; the CapMap
merge that follows is overwritten by PeerCapMap so only the address
filter survives on the peer path.

Two captures land in testdata/nodeattrs_results to anchor the
behaviour:

  - nodeattrs-attr-c15-disable-ipv4         (on tag:client)
  - nodeattrs-attr-c16-disable-ipv4-router  (on tag:router, which
    advertises 10.33.0.0/16, confirming subnet routes survive)
This commit is contained in:
Kristoffer Dalby 2026-05-13 09:58:11 +00:00
parent 64d13f77e8
commit 5d502bfb88
5 changed files with 19639 additions and 3 deletions
Download patch file Download diff file Expand all files Collapse all files

9725
hscontrol/policy/v2/testdata/nodeattrs_results/nodeattrs-attr-c15-disable-ipv4.hujson vendored Normal file
View file

File diff suppressed because it is too large Load diff

9766
hscontrol/policy/v2/testdata/nodeattrs_results/nodeattrs-attr-c16-disable-ipv4-router.hujson vendored Normal file
View file

File diff suppressed because it is too large Load diff