[client] Improve dns match trace log (#3928)

This commit is contained in:
Viktor Liu
2025-06-05 12:39:58 +02:00
committed by GitHub
parent 9424b88db2
commit df82a45d99

View File

@ -1,6 +1,7 @@
package dns
import (
"fmt"
"slices"
"strings"
"sync"
@ -148,61 +149,42 @@ func (c *HandlerChain) ServeDNS(w dns.ResponseWriter, r *dns.Msg) {
}
qname := strings.ToLower(r.Question[0].Name)
log.Tracef("handling DNS request for domain=%s", qname)
c.mu.RLock()
handlers := slices.Clone(c.handlers)
c.mu.RUnlock()
if log.IsLevelEnabled(log.TraceLevel) {
log.Tracef("current handlers (%d):", len(handlers))
var b strings.Builder
b.WriteString(fmt.Sprintf("DNS request domain=%s, handlers (%d):\n", qname, len(handlers)))
for _, h := range handlers {
log.Tracef(" - pattern: domain=%s original: domain=%s wildcard=%v match_subdomain=%v priority=%d",
h.Pattern, h.OrigPattern, h.IsWildcard, h.MatchSubdomains, h.Priority)
b.WriteString(fmt.Sprintf(" - pattern: domain=%s original: domain=%s wildcard=%v match_subdomain=%v priority=%d\n",
h.Pattern, h.OrigPattern, h.IsWildcard, h.MatchSubdomains, h.Priority))
}
log.Trace(strings.TrimSuffix(b.String(), "\n"))
}
// Try handlers in priority order
for _, entry := range handlers {
var matched bool
switch {
case entry.Pattern == ".":
matched = true
case entry.IsWildcard:
parts := strings.Split(strings.TrimSuffix(qname, entry.Pattern), ".")
matched = len(parts) >= 2 && strings.HasSuffix(qname, entry.Pattern)
default:
// For non-wildcard patterns:
// If handler wants subdomain matching, allow suffix match
// Otherwise require exact match
if entry.MatchSubdomains {
matched = strings.EqualFold(qname, entry.Pattern) || strings.HasSuffix(qname, "."+entry.Pattern)
} else {
matched = strings.EqualFold(qname, entry.Pattern)
matched := c.isHandlerMatch(qname, entry)
if matched {
log.Tracef("handler matched: domain=%s -> pattern=%s wildcard=%v match_subdomain=%v priority=%d",
qname, entry.OrigPattern, entry.IsWildcard, entry.MatchSubdomains, entry.Priority)
chainWriter := &ResponseWriterChain{
ResponseWriter: w,
origPattern: entry.OrigPattern,
}
}
entry.Handler.ServeDNS(chainWriter, r)
if !matched {
log.Tracef("trying domain match: request: domain=%s pattern: domain=%s wildcard=%v match_subdomain=%v priority=%d matched=false",
qname, entry.OrigPattern, entry.MatchSubdomains, entry.IsWildcard, entry.Priority)
continue
// If handler wants to continue, try next handler
if chainWriter.shouldContinue {
log.Tracef("handler requested continue to next handler for domain=%s", qname)
continue
}
return
}
log.Tracef("handler matched: request: domain=%s pattern: domain=%s wildcard=%v match_subdomain=%v priority=%d",
qname, entry.OrigPattern, entry.IsWildcard, entry.MatchSubdomains, entry.Priority)
chainWriter := &ResponseWriterChain{
ResponseWriter: w,
origPattern: entry.OrigPattern,
}
entry.Handler.ServeDNS(chainWriter, r)
// If handler wants to continue, try next handler
if chainWriter.shouldContinue {
log.Tracef("handler requested continue to next handler")
continue
}
return
}
// No handler matched or all handlers passed
@ -213,3 +195,22 @@ func (c *HandlerChain) ServeDNS(w dns.ResponseWriter, r *dns.Msg) {
log.Errorf("failed to write DNS response: %v", err)
}
}
func (c *HandlerChain) isHandlerMatch(qname string, entry HandlerEntry) bool {
switch {
case entry.Pattern == ".":
return true
case entry.IsWildcard:
parts := strings.Split(strings.TrimSuffix(qname, entry.Pattern), ".")
return len(parts) >= 2 && strings.HasSuffix(qname, entry.Pattern)
default:
// For non-wildcard patterns:
// If handler wants subdomain matching, allow suffix match
// Otherwise require exact match
if entry.MatchSubdomains {
return strings.EqualFold(qname, entry.Pattern) || strings.HasSuffix(qname, "."+entry.Pattern)
} else {
return strings.EqualFold(qname, entry.Pattern)
}
}
}