diff options
Diffstat (limited to 'libgo/go/net/dnsclient.go')
| -rw-r--r-- | libgo/go/net/dnsclient.go | 67 |
1 files changed, 28 insertions, 39 deletions
diff --git a/libgo/go/net/dnsclient.go b/libgo/go/net/dnsclient.go index e8014e4ffc9..ce48521bc60 100644 --- a/libgo/go/net/dnsclient.go +++ b/libgo/go/net/dnsclient.go @@ -9,31 +9,6 @@ import ( "sort" ) -// DNSError represents a DNS lookup error. -type DNSError struct { - Err string // description of the error - Name string // name looked for - Server string // server used - IsTimeout bool -} - -func (e *DNSError) Error() string { - if e == nil { - return "<nil>" - } - s := "lookup " + e.Name - if e.Server != "" { - s += " on " + e.Server - } - s += ": " + e.Err - return s -} - -func (e *DNSError) Timeout() bool { return e.IsTimeout } -func (e *DNSError) Temporary() bool { return e.IsTimeout } - -const noSuchHost = "no such host" - // reverseaddr returns the in-addr.arpa. or ip6.arpa. hostname of the IP // address addr suitable for rDNS (PTR) record lookup or an error if it fails // to parse the IP address. @@ -43,8 +18,7 @@ func reverseaddr(addr string) (arpa string, err error) { return "", &DNSError{Err: "unrecognized address", Name: addr} } if ip.To4() != nil { - return itoa(int(ip[15])) + "." + itoa(int(ip[14])) + "." + itoa(int(ip[13])) + "." + - itoa(int(ip[12])) + ".in-addr.arpa.", nil + return uitoa(uint(ip[15])) + "." + uitoa(uint(ip[14])) + "." + uitoa(uint(ip[13])) + "." + uitoa(uint(ip[12])) + ".in-addr.arpa.", nil } // Must be IPv6 buf := make([]byte, 0, len(ip)*4+len("ip6.arpa.")) @@ -67,7 +41,7 @@ func answer(name, server string, dns *dnsMsg, qtype uint16) (cname string, addrs addrs = make([]dnsRR, 0, len(dns.answer)) if dns.rcode == dnsRcodeNameError && dns.recursion_available { - return "", nil, &DNSError{Err: noSuchHost, Name: name} + return "", nil, &DNSError{Err: errNoSuchHost.Error(), Name: name, Server: server} } if dns.rcode != dnsRcodeSuccess { // None of the error codes make sense @@ -94,7 +68,7 @@ Cname: continue } h := rr.Header() - if h.Class == dnsClassINET && h.Name == name { + if h.Class == dnsClassINET && equalASCIILabel(h.Name, name) { switch h.Rrtype { case qtype: addrs = append(addrs, rr) @@ -106,7 +80,7 @@ Cname: } } if len(addrs) == 0 { - return "", nil, &DNSError{Err: noSuchHost, Name: name, Server: server} + return "", nil, &DNSError{Err: errNoSuchHost.Error(), Name: name, Server: server} } return name, addrs, nil } @@ -114,6 +88,26 @@ Cname: return "", nil, &DNSError{Err: "too many redirects", Name: name, Server: server} } +func equalASCIILabel(x, y string) bool { + if len(x) != len(y) { + return false + } + for i := 0; i < len(x); i++ { + a := x[i] + b := y[i] + if 'A' <= a && a <= 'Z' { + a += 0x20 + } + if 'A' <= b && b <= 'Z' { + b += 0x20 + } + if a != b { + return false + } + } + return true +} + func isDomainName(s string) bool { // See RFC 1035, RFC 3696. if len(s) == 0 { @@ -174,13 +168,10 @@ type SRV struct { type byPriorityWeight []*SRV func (s byPriorityWeight) Len() int { return len(s) } - -func (s byPriorityWeight) Swap(i, j int) { s[i], s[j] = s[j], s[i] } - func (s byPriorityWeight) Less(i, j int) bool { - return s[i].Priority < s[j].Priority || - (s[i].Priority == s[j].Priority && s[i].Weight < s[j].Weight) + return s[i].Priority < s[j].Priority || (s[i].Priority == s[j].Priority && s[i].Weight < s[j].Weight) } +func (s byPriorityWeight) Swap(i, j int) { s[i], s[j] = s[j], s[i] } // shuffleByWeight shuffles SRV records by weight using the algorithm // described in RFC 2782. @@ -228,11 +219,9 @@ type MX struct { // byPref implements sort.Interface to sort MX records by preference type byPref []*MX -func (s byPref) Len() int { return len(s) } - +func (s byPref) Len() int { return len(s) } func (s byPref) Less(i, j int) bool { return s[i].Pref < s[j].Pref } - -func (s byPref) Swap(i, j int) { s[i], s[j] = s[j], s[i] } +func (s byPref) Swap(i, j int) { s[i], s[j] = s[j], s[i] } // sort reorders MX records as specified in RFC 5321. func (s byPref) sort() { |