compileFilterRules skipped autogroup:internet destinations to keep them
out of the wire-format PacketFilter, but those same compiled rules are
the source of pm.matchers — and Node.CanAccess relies on a matcher whose
DestsIsTheInternet covers the public internet to surface exit-node peers
to ACL sources. With the skip in place no such matcher existed, exit
nodes silently dropped out of the source's peer list, and the docs'
exit-node walkthrough stopped working: `tailscale exit-node list`
returned "no exit nodes found" and `tailscale set --exit-node=<ip>`
returned "no node found in netmap with IP".
Drop the compile-time skip so autogroup:internet flows through normal
matcher derivation, and teach ReduceFilterRules to keep the resulting
client packet-filter rule on exit-route advertisers — Tailscale SaaS
sends those rules to exit nodes so the kernel filter accepts traffic
forwarded by autogroup:internet sources.
Verified against a live tailnet on 2026-04-28 via tscap; the b17/b18
captures land under testdata/issue_3212/ as a regression guard. The
captures are isolated from testdata/routes_results/ because the broader
TestRoutesCompat machinery assumes a CIDR-prefix wire format that
differs from the IPSet-range form SaaS emits for autogroup:internet —
aligning that wire format is tracked separately.
Fixes#3212
reduceCapGrantRule was dropping rules whose CapGrant IPs overlap a
subnet route; treat subnet routes as part of node identity so those rules
survive reduction. ReduceFilterRules now also reduces route-reachable
destinations.
Updates #3157
Compile grant app fields into CapGrant FilterRules matching Tailscale
SaaS behavior. Key changes:
- Generate CapGrant rules in compileFilterRules and
compileGrantWithAutogroupSelf, with node-specific /32 and /128
Dsts for autogroup:self grants
- Add reversed companion rules for drive→drive-sharer and
relay→relay-target capabilities, ordered by original cap name
- Narrow broad CapGrant Dsts to node-specific prefixes in
ReduceFilterRules via new reduceCapGrantRule helper
- Skip merging CapGrant rules in mergeFilterRules to preserve
per-capability structure
- Remove ip+app mutual exclusivity validation (Tailscale accepts both)
- Add semantic JSON comparison for RawMessage types and netip.Prefix
comparators in test infrastructure
Reduces grant compat test skips from 99 to 41 (58 newly passing).
Updates #2180
Add exit route check in ReduceFilterRules to prevent exit nodes from receiving packet filter rules for destinations that only overlap via exit routes. Remove resolved SUBNET_ROUTE_FILTER_RULES grant skip entries and update error message formatting for grant validation.
Updates #2180
