sendnrw/netbird
2
0
Fork 0
mirror of https://github.com/netbirdio/netbird.git synced 2026-07-23 17:01:29 +02:00
Code Issues Packages Projects Releases Wiki Activity

Extract arpa reverse-name parsing into per-family helpers

Browse Source
This commit is contained in:
Viktor Liu
2026-06-17 15:13:47 +02:00
parent 3a6852cbc2
commit dc7adf725c
1 changed files with 39 additions and 29 deletions
Download Patch File Download Diff File Expand all files Collapse all files

68
client/internal/dns/resutil/resolve.go
View File

@@ -336,41 +336,51 @@ func ptrQueryAddr(qname string) (string, bool) {
switch {
case strings.HasSuffix(name, ".in-addr.arpa"):
labels := strings.Split(strings.TrimSuffix(name, ".in-addr.arpa"), ".")
if len(labels) != 4 {
return "", false
}
slices.Reverse(labels)
addr, err := netip.ParseAddr(strings.Join(labels, "."))
if err != nil || !addr.Is4() {
return "", false
}
return addr.String(), true
return parseInAddrArpa(strings.TrimSuffix(name, ".in-addr.arpa"))
case strings.HasSuffix(name, ".ip6.arpa"):
nibbles := strings.Split(strings.TrimSuffix(name, ".ip6.arpa"), ".")
if len(nibbles) != 32 {
return "", false
}
slices.Reverse(nibbles)
var sb strings.Builder
for i, n := range nibbles {
if i > 0 && i%4 == 0 {
sb.WriteByte(':')
}
sb.WriteString(n)
}
addr, err := netip.ParseAddr(sb.String())
if err != nil || !addr.Is6() {
return "", false
}
return addr.String(), true
return parseIP6Arpa(strings.TrimSuffix(name, ".ip6.arpa"))
default:
return "", false
}
}
// parseInAddrArpa turns the label portion of an in-addr.arpa name into an IPv4
// address string, reporting false when it is not a well-formed reverse name.
func parseInAddrArpa(labelPart string) (string, bool) {
labels := strings.Split(labelPart, ".")
if len(labels) != 4 {
return "", false
}
slices.Reverse(labels)
addr, err := netip.ParseAddr(strings.Join(labels, "."))
if err != nil || !addr.Is4() {
return "", false
}
return addr.String(), true
}
// parseIP6Arpa turns the nibble portion of an ip6.arpa name into an IPv6
// address string, reporting false when it is not a well-formed reverse name.
func parseIP6Arpa(nibblePart string) (string, bool) {
nibbles := strings.Split(nibblePart, ".")
if len(nibbles) != 32 {
return "", false
}
slices.Reverse(nibbles)
var sb strings.Builder
for i, n := range nibbles {
if i > 0 && i%4 == 0 {
sb.WriteByte(':')
}
sb.WriteString(n)
}
addr, err := netip.ParseAddr(sb.String())
if err != nil || !addr.Is6() {
return "", false
}
return addr.String(), true
}
// rcodeForRecordError maps a non-address lookup error to a DNS rcode. A
// not-found result becomes NODATA rather than NXDOMAIN: net.DNSError.IsNotFound
// does not distinguish a missing name from a name that exists only with records