Exchange and Lookup held rulesAccess.RLock across all DNS network I/O,
blocking rebuildRules from swapping in new rules until every in-flight
query finished. Replace the RWMutex with an atomic pointer to a
refcounted rulesSnapshot so queries only hold a snapshot reference
during execution, allowing concurrent rule rebuilds.
Remove SetIncludeAllowed(true) from the DNS record zone parser.
The $INCLUDE directive allows opening arbitrary files via os.Open,
which is unnecessary and dangerous when parsing a single record string
from configuration (especially remote profiles).
Fix displayRuleIndex arithmetic in dns/router.go that computed
2*index+1 instead of the correct 0-based index. This was a
reintroduction of a bug previously fixed in be8ee370a. Both
matchDNS and logRuleMatch now use the index directly, matching
the pattern in route/route.go.
Legacy DNS address-filter mode still accepts destination-side IP
predicates with a deprecation warning, but the recent evaluate/
match_response refactor started evaluating those predicates during
pre-response Match(). That broke rules whose transport selection must
be deferred until MatchAddressLimit() can inspect the upstream reply.
Restore the old defer behavior by reintroducing an internal
IgnoreDestinationIPCIDRMatch flag on InboundContext and using it only
for legacy pre-response DNS matching. Default and logical DNS rules now
carry the legacy mode bit, set the ignore flag on metadata copies while
performing pre-response Match(), and explicitly clear it again for
match_response and MatchAddressLimit() so response-phase matching still
checks the returned addresses.
Add regression coverage for direct legacy destination-IP rules,
rule_set-backed CIDR rules, logical wrappers, and the legacy Lookup
router path, including fallback after a rejected response. This keeps
legacy configs working without changing new-mode evaluate semantics.
Tests: go test ./route/rule ./dns
Tests: make
The cache deduplication in Client.Exchange uses a channel-based lock
per DNS question. Waiting goroutines blocked on <-cond without context
awareness, causing them to accumulate indefinitely when the owning
goroutine's transport call stalls. Add select on ctx.Done() so waiters
respect context cancellation and timeouts.
We mistakenly believed that `libresolv`'s `search` function worked correctly in NetworkExtension, but it seems only `getaddrinfo` does.
This commit changes the behavior of the `local` DNS server in NetworkExtension to prefer DHCP, falling back to `getaddrinfo` if DHCP servers are unavailable.
It's worth noting that `prefer_go` does not disable DHCP since it respects Dial Fields, but `getaddrinfo` does the opposite. The new behavior only applies to NetworkExtension, not to all scenarios (primarily command-line binaries) as it did previously.
In addition, this commit also improves the DHCP DNS server to use the same robust query logic as `local`.
Previously, the buffer was not reset within the response loop. If a packet
handle failed or completed, the buffer retained its state. Specifically,
if `ReadPacketFrom` returned `io.ErrShortBuffer`, the error was ignored
via `continue`, but the buffer remained full. This caused the next
read attempt to immediately fail with the same error, creating a tight
busy-wait loop that consumed 100% CPU.
Validates `buffer.Reset()` is called at the start of each iteration to
ensure a clean state for 'ReadPacketFrom'.
The cache lookup was performed before rule matching, using the caller's
strategy (usually AsIS/0) instead of the resolved strategy. This caused
cache misses when ipv4_only was configured globally but the cache lookup
expected both A and AAAA records.
Remove LookupCache and ExchangeCache from Router, as the cache checks
inside client.Lookup and client.Exchange already handle caching correctly
after rule matching with the proper strategy and transport.
