NameToAAAA() converts IPv6 addresses

IPv6 only works on dashes, not dots. Mostly because the double-colon:
`--1` → `::1`. The double-colon, in dot-notation, would be `..`, which
is invalid in DNS.
This commit is contained in:
Brian Cunnie
2020-08-19 11:41:27 -07:00
parent 0badb9238b
commit 06daa8ab29
2 changed files with 48 additions and 3 deletions

View File

@@ -10,6 +10,7 @@ import (
// https://stackoverflow.com/questions/53497/regular-expression-that-matches-valid-ipv6-addresses // https://stackoverflow.com/questions/53497/regular-expression-that-matches-valid-ipv6-addresses
var ipv4RE= regexp.MustCompile(`(^|[.-])(((25[0-5]|(2[0-4]|1{0,1}[0-9]){0,1}[0-9])[.-]){3,3}(25[0-5]|(2[0-4]|1{0,1}[0-9]){0,1}[0-9]))($|[.-])`) var ipv4RE= regexp.MustCompile(`(^|[.-])(((25[0-5]|(2[0-4]|1{0,1}[0-9]){0,1}[0-9])[.-]){3,3}(25[0-5]|(2[0-4]|1{0,1}[0-9]){0,1}[0-9]))($|[.-])`)
var ipv6RE= regexp.MustCompile(`(^|[.-])(([0-9a-fA-F]{1,4}-){7,7}[0-9a-fA-F]{1,4}|([0-9a-fA-F]{1,4}-){1,7}-|([0-9a-fA-F]{1,4}-){1,6}-[0-9a-fA-F]{1,4}|([0-9a-fA-F]{1,4}-){1,5}(-[0-9a-fA-F]{1,4}){1,2}|([0-9a-fA-F]{1,4}-){1,4}(-[0-9a-fA-F]{1,4}){1,3}|([0-9a-fA-F]{1,4}-){1,3}(-[0-9a-fA-F]{1,4}){1,4}|([0-9a-fA-F]{1,4}-){1,2}(-[0-9a-fA-F]{1,4}){1,5}|[0-9a-fA-F]{1,4}-((-[0-9a-fA-F]{1,4}){1,6})|-((-[0-9a-fA-F]{1,4}){1,7}|-)|fe80-(-[0-9a-fA-F]{0,4}){0,4}%[0-9a-zA-Z]{1,}|--(ffff(-0{1,4}){0,1}-){0,1}((25[0-5]|(2[0-4]|1{0,1}[0-9]){0,1}[0-9])\.){3,3}(25[0-5]|(2[0-4]|1{0,1}[0-9]){0,1}[0-9])|([0-9a-fA-F]{1,4}-){1,4}-((25[0-5]|(2[0-4]|1{0,1}[0-9]){0,1}[0-9])\.){3,3}(25[0-5]|(2[0-4]|1{0,1}[0-9]){0,1}[0-9]))($|[.-])`)
func NameToA (fqdnString string) (dnsmessage.AResource, error) { func NameToA (fqdnString string) (dnsmessage.AResource, error) {
fqdn:=[]byte(fqdnString) fqdn:=[]byte(fqdnString)
@@ -23,3 +24,21 @@ func NameToA (fqdnString string) (dnsmessage.AResource, error) {
return dnsmessage.AResource{A: [4]byte{ipv4address[0], ipv4address[1], ipv4address[2], ipv4address[3]}}, nil return dnsmessage.AResource{A: [4]byte{ipv4address[0], ipv4address[1], ipv4address[2], ipv4address[3]}}, nil
} }
func NameToAAAA (fqdnString string) (dnsmessage.AAAAResource, error) {
fqdn:=[]byte(fqdnString)
if ! ipv6RE.Match(fqdn) {
return dnsmessage.AAAAResource{}, errors.New("ENOTFOUND") // I can't help it; I love the old-style UNIX errors
}
match := string(ipv6RE.FindSubmatch(fqdn)[2])
match = strings.Replace(match, "-", ":", -1)
ipv16address := net.ParseIP(match).To16()
AAAAR := dnsmessage.AAAAResource{}
for i, _ := range ipv16address {
AAAAR.AAAA[i] = ipv16address[i]
}
return AAAAR, nil
}

View File

@@ -32,9 +32,7 @@ var _ = Describe("Xip", func() {
DescribeTable("when it does not match an IP address", DescribeTable("when it does not match an IP address",
func(fqdn string) { func(fqdn string) {
_, err := xip.NameToA(fqdn) _, err := xip.NameToA(fqdn)
//ipv4Answer, err := xip.NameToA(fqdn)
Expect(err).To(MatchError(errors.New("ENOTFOUND"))) Expect(err).To(MatchError(errors.New("ENOTFOUND")))
//Expect(ipv4Answer).To(Equal(dnsmessage.AResource{})) // is this important to test?
}, },
Entry("empty string", ""), Entry("empty string", ""),
Entry("bare domain", "nono.io"), Entry("bare domain", "nono.io"),
@@ -44,4 +42,32 @@ var _ = Describe("Xip", func() {
Entry("too big", "256.254.253.252"), Entry("too big", "256.254.253.252"),
) )
}) })
Describe("NameToAAAA()", func() {
DescribeTable("when it succeeds",
func(fqdn string, expectedAAAA dnsmessage.AAAAResource) {
ipv6Answer, err := xip.NameToAAAA(fqdn)
Expect(err).To(Not(HaveOccurred()))
Expect(ipv6Answer).To(Equal(expectedAAAA))
},
// dashes only
Entry("loopback", "--1", dnsmessage.AAAAResource{AAAA: [16]byte{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1}}),
Entry("ff with domain", "fffe-fdfc-fbfa-f9f8-f7f6-f5f4-f3f2-f1f0.com", dnsmessage.AAAAResource{AAAA: [16]byte{255, 254, 253, 252, 251, 250, 249, 248, 247, 246, 245, 244, 243, 242, 241, 240}}),
Entry("ff with domain and pre", "www.fffe-fdfc-fbfa-f9f8-f7f6-f5f4-f3f2-f1f0.com", dnsmessage.AAAAResource{AAAA: [16]byte{255, 254, 253, 252, 251, 250, 249, 248, 247, 246, 245, 244, 243, 242, 241, 240}}),
Entry("ff with domain dashes", "1.www-fffe-fdfc-fbfa-f9f8-f7f6-f5f4-f3f2-f1f0-1.com", dnsmessage.AAAAResource{AAAA: [16]byte{255, 254, 253, 252, 251, 250, 249, 248, 247, 246, 245, 244, 243, 242, 241, 240}}),
)
DescribeTable("when it does not match an IP address",
func(fqdn string) {
_, err := xip.NameToAAAA(fqdn)
//ipv4Answer, err := xip.NameToA(fqdn)
Expect(err).To(MatchError(errors.New("ENOTFOUND")))
//Expect(ipv4Answer).To(Equal(dnsmessage.AAAAResource{})) // is this important to test?
},
Entry("empty string", ""),
Entry("bare domain", "nono.io"),
Entry("canonical domain", "sslip.io"),
Entry("www", "www.sslip.io"),
Entry("a 1 without double-dash", "-1"),
Entry("too big", "--g"),
)
})
}) })