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mirror of https://github.com/golang/go synced 2024-11-05 11:36:10 -07:00

net: fix inconsistent error values on Lookup

This change fixes inconsistent error values on
Lookup{Addr,CNAME,Host,IP.MX,NS,Port,SRV,TXT}.

Updates #4856.

Change-Id: I059bc8ffb96ee74dff8a8c4e8e6ae3e4a462a7ef
Reviewed-on: https://go-review.googlesource.com/9108
Reviewed-by: Ian Lance Taylor <iant@golang.org>
This commit is contained in:
Mikio Hara 2015-04-19 20:54:01 +09:00
parent 456cf0f22c
commit 0fc582e879
9 changed files with 177 additions and 192 deletions

View File

@ -54,7 +54,7 @@ func cgoLookupPort(network, service string) (port int, err error, completed bool
hints.ai_socktype = C.SOCK_DGRAM
hints.ai_protocol = C.IPPROTO_UDP
default:
return 0, UnknownNetworkError(network), true
return 0, &DNSError{Err: "unknown network", Name: network + "/" + service}, true
}
if len(network) >= 4 {
switch network[3] {
@ -78,7 +78,7 @@ func cgoLookupPort(network, service string) (port int, err error, completed bool
default:
err = addrinfoErrno(gerrno)
}
return 0, err, true
return 0, &DNSError{Err: err.Error(), Name: network + "/" + service}, true
}
defer C.freeaddrinfo(res)
@ -94,7 +94,7 @@ func cgoLookupPort(network, service string) (port int, err error, completed bool
return int(p[0])<<8 | int(p[1]), nil, true
}
}
return 0, &AddrError{"unknown port", network + "/" + service}, true
return 0, &DNSError{Err: "unknown port", Name: network + "/" + service}, true
}
func cgoLookupIPCNAME(name string) (addrs []IPAddr, cname string, err error, completed bool) {
@ -110,7 +110,6 @@ func cgoLookupIPCNAME(name string) (addrs []IPAddr, cname string, err error, com
var res *C.struct_addrinfo
gerrno, err := C.getaddrinfo(h, nil, &hints, &res)
if gerrno != 0 {
var str string
switch gerrno {
case C.EAI_SYSTEM:
if err == nil {
@ -123,13 +122,12 @@ func cgoLookupIPCNAME(name string) (addrs []IPAddr, cname string, err error, com
// comes up again. golang.org/issue/6232.
err = syscall.EMFILE
}
str = err.Error()
case C.EAI_NONAME:
str = noSuchHost
err = errNoSuchHost
default:
str = addrinfoErrno(gerrno).Error()
err = addrinfoErrno(gerrno)
}
return nil, "", &DNSError{Err: str, Name: name}, true
return nil, "", &DNSError{Err: err.Error(), Name: name}, true
}
defer C.freeaddrinfo(res)

View File

@ -9,38 +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 // if true, timed out; not all timeouts set this
}
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
}
// Timeout reports whether the DNS lookup is known to have timed out.
// This is not always known; a DNS lookup may fail due to a timeout
// and return a DNSError for which Timeout returns false.
func (e *DNSError) Timeout() bool { return e.IsTimeout }
// Temporary reports whether the DNS error is known to be temporary.
// This is not always known; a DNS lookup may fail due to a temporary
// error and return a DNSError for which Temporary returns false.
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.
@ -50,8 +18,7 @@ func reverseaddr(addr string) (arpa string, err error) {
return "", &DNSError{Err: "unrecognized address", Name: addr}
}
if ip.To4() != nil {
return uitoa(uint(ip[15])) + "." + uitoa(uint(ip[14])) + "." + uitoa(uint(ip[13])) + "." +
uitoa(uint(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."))
@ -74,7 +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}
}
if dns.rcode != dnsRcodeSuccess {
// None of the error codes make sense
@ -113,7 +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
}
@ -201,13 +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.
@ -255,11 +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() {

View File

@ -185,7 +185,7 @@ func tryOneName(cfg *dnsConfig, name string, qtype uint16) (string, []dnsRR, err
continue
}
cname, addrs, err := answer(name, server, msg, qtype)
if err == nil || err.(*DNSError).Err == noSuchHost {
if err == nil || err.(*DNSError).Err == errNoSuchHost.Error() {
return cname, addrs, err
}
lastErr = err
@ -269,7 +269,7 @@ func loadConfig(resolvConfPath string, reloadTime time.Duration, quit <-chan cha
}()
}
func lookup(name string, qtype uint16) (cname string, addrs []dnsRR, err error) {
func lookup(name string, qtype uint16) (cname string, rrs []dnsRR, err error) {
if !isDomainName(name) {
return name, nil, &DNSError{Err: "invalid domain name", Name: name}
}
@ -296,7 +296,7 @@ func lookup(name string, qtype uint16) (cname string, addrs []dnsRR, err error)
rname += "."
}
// Can try as ordinary name.
cname, addrs, err = tryOneName(cfg.dnsConfig, rname, qtype)
cname, rrs, err = tryOneName(cfg.dnsConfig, rname, qtype)
if rooted || err == nil {
return
}
@ -308,7 +308,7 @@ func lookup(name string, qtype uint16) (cname string, addrs []dnsRR, err error)
if rname[len(rname)-1] != '.' {
rname += "."
}
cname, addrs, err = tryOneName(cfg.dnsConfig, rname, qtype)
cname, rrs, err = tryOneName(cfg.dnsConfig, rname, qtype)
if err == nil {
return
}
@ -317,7 +317,7 @@ func lookup(name string, qtype uint16) (cname string, addrs []dnsRR, err error)
// Last ditch effort: try unsuffixed only if we haven't already,
// that is, name is not rooted and has less than ndots dots.
if count(name, '.') < cfg.dnsConfig.ndots {
cname, addrs, err = tryOneName(cfg.dnsConfig, name+".", qtype)
cname, rrs, err = tryOneName(cfg.dnsConfig, name+".", qtype)
if err == nil {
return
}

View File

@ -132,22 +132,22 @@ func LookupSRV(service, proto, name string) (cname string, addrs []*SRV, err err
}
// LookupMX returns the DNS MX records for the given domain name sorted by preference.
func LookupMX(name string) (mx []*MX, err error) {
func LookupMX(name string) (mxs []*MX, err error) {
return lookupMX(name)
}
// LookupNS returns the DNS NS records for the given domain name.
func LookupNS(name string) (ns []*NS, err error) {
func LookupNS(name string) (nss []*NS, err error) {
return lookupNS(name)
}
// LookupTXT returns the DNS TXT records for the given domain name.
func LookupTXT(name string) (txt []string, err error) {
func LookupTXT(name string) (txts []string, err error) {
return lookupTXT(name)
}
// LookupAddr performs a reverse lookup for the given address, returning a list
// of names mapping to that address.
func LookupAddr(addr string) (name []string, err error) {
func LookupAddr(addr string) (names []string, err error) {
return lookupAddr(addr)
}

View File

@ -6,10 +6,7 @@
package net
import (
"errors"
"sync"
)
import "sync"
var onceReadProtocols sync.Once
@ -43,126 +40,121 @@ func readProtocols() {
// lookupProtocol looks up IP protocol name in /etc/protocols and
// returns correspondent protocol number.
func lookupProtocol(name string) (proto int, err error) {
func lookupProtocol(name string) (int, error) {
onceReadProtocols.Do(readProtocols)
proto, found := protocols[name]
if !found {
return 0, errors.New("unknown IP protocol specified: " + name)
return 0, &AddrError{Err: "unknown IP protocol specified", Addr: name}
}
return
return proto, nil
}
func lookupHost(host string) (addrs []string, err error) {
func lookupHost(host string) ([]string, error) {
addrs, err, ok := cgoLookupHost(host)
if !ok {
addrs, err = goLookupHost(host)
}
return
return addrs, err
}
func lookupIP(host string) (addrs []IPAddr, err error) {
func lookupIP(host string) ([]IPAddr, error) {
addrs, err, ok := cgoLookupIP(host)
if !ok {
addrs, err = goLookupIP(host)
}
return
return addrs, err
}
func lookupPort(network, service string) (port int, err error) {
func lookupPort(network, service string) (int, error) {
port, err, ok := cgoLookupPort(network, service)
if !ok {
port, err = goLookupPort(network, service)
}
return
return port, err
}
func lookupCNAME(name string) (cname string, err error) {
func lookupCNAME(name string) (string, error) {
cname, err, ok := cgoLookupCNAME(name)
if !ok {
cname, err = goLookupCNAME(name)
}
return
return cname, err
}
func lookupSRV(service, proto, name string) (cname string, addrs []*SRV, err error) {
func lookupSRV(service, proto, name string) (string, []*SRV, error) {
var target string
if service == "" && proto == "" {
target = name
} else {
target = "_" + service + "._" + proto + "." + name
}
var records []dnsRR
cname, records, err = lookup(target, dnsTypeSRV)
cname, rrs, err := lookup(target, dnsTypeSRV)
if err != nil {
return
return "", nil, err
}
addrs = make([]*SRV, len(records))
for i, rr := range records {
r := rr.(*dnsRR_SRV)
addrs[i] = &SRV{r.Target, r.Port, r.Priority, r.Weight}
srvs := make([]*SRV, len(rrs))
for i, rr := range rrs {
rr := rr.(*dnsRR_SRV)
srvs[i] = &SRV{Target: rr.Target, Port: rr.Port, Priority: rr.Priority, Weight: rr.Weight}
}
byPriorityWeight(addrs).sort()
return
byPriorityWeight(srvs).sort()
return cname, srvs, nil
}
func lookupMX(name string) (mx []*MX, err error) {
_, records, err := lookup(name, dnsTypeMX)
func lookupMX(name string) ([]*MX, error) {
_, rrs, err := lookup(name, dnsTypeMX)
if err != nil {
return
return nil, err
}
mx = make([]*MX, len(records))
for i, rr := range records {
r := rr.(*dnsRR_MX)
mx[i] = &MX{r.Mx, r.Pref}
mxs := make([]*MX, len(rrs))
for i, rr := range rrs {
rr := rr.(*dnsRR_MX)
mxs[i] = &MX{Host: rr.Mx, Pref: rr.Pref}
}
byPref(mx).sort()
return
byPref(mxs).sort()
return mxs, nil
}
func lookupNS(name string) (ns []*NS, err error) {
_, records, err := lookup(name, dnsTypeNS)
func lookupNS(name string) ([]*NS, error) {
_, rrs, err := lookup(name, dnsTypeNS)
if err != nil {
return
return nil, err
}
ns = make([]*NS, len(records))
for i, r := range records {
r := r.(*dnsRR_NS)
ns[i] = &NS{r.Ns}
nss := make([]*NS, len(rrs))
for i, rr := range rrs {
nss[i] = &NS{Host: rr.(*dnsRR_NS).Ns}
}
return
return nss, nil
}
func lookupTXT(name string) (txt []string, err error) {
_, records, err := lookup(name, dnsTypeTXT)
func lookupTXT(name string) ([]string, error) {
_, rrs, err := lookup(name, dnsTypeTXT)
if err != nil {
return
return nil, err
}
txt = make([]string, len(records))
for i, r := range records {
txt[i] = r.(*dnsRR_TXT).Txt
txts := make([]string, len(rrs))
for i, rr := range rrs {
txts[i] = rr.(*dnsRR_TXT).Txt
}
return
return txts, nil
}
func lookupAddr(addr string) (name []string, err error) {
name = lookupStaticAddr(addr)
if len(name) > 0 {
return
func lookupAddr(addr string) ([]string, error) {
names := lookupStaticAddr(addr)
if len(names) > 0 {
return names, nil
}
var arpa string
arpa, err = reverseaddr(addr)
arpa, err := reverseaddr(addr)
if err != nil {
return
return nil, err
}
var records []dnsRR
_, records, err = lookup(arpa, dnsTypePTR)
_, rrs, err := lookup(arpa, dnsTypePTR)
if err != nil {
return
return nil, err
}
name = make([]string, len(records))
for i := range records {
r := records[i].(*dnsRR_PTR)
name[i] = r.Ptr
ptrs := make([]string, len(rrs))
for i, rr := range rrs {
ptrs[i] = rr.(*dnsRR_PTR).Ptr
}
return
return ptrs, nil
}

View File

@ -5,7 +5,6 @@
package net
import (
"os"
"runtime"
"syscall"
"unsafe"
@ -19,13 +18,13 @@ var (
func getprotobyname(name string) (proto int, err error) {
p, err := syscall.GetProtoByName(name)
if err != nil {
return 0, os.NewSyscallError("GetProtoByName", err)
return 0, err
}
return int(p.Proto), nil
}
// lookupProtocol looks up IP protocol name and returns correspondent protocol number.
func lookupProtocol(name string) (proto int, err error) {
func lookupProtocol(name string) (int, error) {
// GetProtoByName return value is stored in thread local storage.
// Start new os thread before the call to prevent races.
type result struct {
@ -46,27 +45,28 @@ func lookupProtocol(name string) (proto int, err error) {
if proto, ok := protocols[name]; ok {
return proto, nil
}
r.err = &DNSError{Err: r.err.Error(), Name: name}
}
return r.proto, r.err
}
func lookupHost(name string) (addrs []string, err error) {
func lookupHost(name string) ([]string, error) {
ips, err := LookupIP(name)
if err != nil {
return
return nil, err
}
addrs = make([]string, 0, len(ips))
addrs := make([]string, 0, len(ips))
for _, ip := range ips {
addrs = append(addrs, ip.String())
}
return
return addrs, nil
}
func gethostbyname(name string) (addrs []IPAddr, err error) {
// caller already acquired thread
h, err := syscall.GetHostByName(name)
if err != nil {
return nil, os.NewSyscallError("GetHostByName", err)
return nil, err
}
switch h.AddrType {
case syscall.AF_INET:
@ -77,12 +77,12 @@ func gethostbyname(name string) (addrs []IPAddr, err error) {
}
addrs = addrs[0:i]
default: // TODO(vcc): Implement non IPv4 address lookups.
return nil, os.NewSyscallError("LookupIP", syscall.EWINDOWS)
return nil, syscall.EWINDOWS
}
return addrs, nil
}
func oldLookupIP(name string) (addrs []IPAddr, err error) {
func oldLookupIP(name string) ([]IPAddr, error) {
// GetHostByName return value is stored in thread local storage.
// Start new os thread before the call to prevent races.
type result struct {
@ -99,10 +99,13 @@ func oldLookupIP(name string) (addrs []IPAddr, err error) {
ch <- result{addrs: addrs, err: err}
}()
r := <-ch
return addrs, r.err
if r.err != nil {
r.err = &DNSError{Err: r.err.Error(), Name: name}
}
return r.addrs, r.err
}
func newLookupIP(name string) (addrs []IPAddr, err error) {
func newLookupIP(name string) ([]IPAddr, error) {
acquireThread()
defer releaseThread()
hints := syscall.AddrinfoW{
@ -113,10 +116,10 @@ func newLookupIP(name string) (addrs []IPAddr, err error) {
var result *syscall.AddrinfoW
e := syscall.GetAddrInfoW(syscall.StringToUTF16Ptr(name), nil, &hints, &result)
if e != nil {
return nil, os.NewSyscallError("GetAddrInfoW", e)
return nil, &DNSError{Err: e.Error(), Name: name}
}
defer syscall.FreeAddrInfoW(result)
addrs = make([]IPAddr, 0, 5)
addrs := make([]IPAddr, 0, 5)
for ; result != nil; result = result.Next {
addr := unsafe.Pointer(result.Addr)
switch result.Family {
@ -128,13 +131,13 @@ func newLookupIP(name string) (addrs []IPAddr, err error) {
zone := zoneToString(int((*syscall.RawSockaddrInet6)(addr).Scope_id))
addrs = append(addrs, IPAddr{IP: IP{a[0], a[1], a[2], a[3], a[4], a[5], a[6], a[7], a[8], a[9], a[10], a[11], a[12], a[13], a[14], a[15]}, Zone: zone})
default:
return nil, os.NewSyscallError("LookupIP", syscall.EWINDOWS)
return nil, &DNSError{Err: syscall.EWINDOWS.Error(), Name: name}
}
}
return addrs, nil
}
func getservbyname(network, service string) (port int, err error) {
func getservbyname(network, service string) (int, error) {
acquireThread()
defer releaseThread()
switch network {
@ -145,12 +148,12 @@ func getservbyname(network, service string) (port int, err error) {
}
s, err := syscall.GetServByName(service, network)
if err != nil {
return 0, os.NewSyscallError("GetServByName", err)
return 0, err
}
return int(syscall.Ntohs(s.Port)), nil
}
func oldLookupPort(network, service string) (port int, err error) {
func oldLookupPort(network, service string) (int, error) {
// GetServByName return value is stored in thread local storage.
// Start new os thread before the call to prevent races.
type result struct {
@ -167,10 +170,13 @@ func oldLookupPort(network, service string) (port int, err error) {
ch <- result{port: port, err: err}
}()
r := <-ch
if r.err != nil {
r.err = &DNSError{Err: r.err.Error(), Name: network + "/" + service}
}
return r.port, r.err
}
func newLookupPort(network, service string) (port int, err error) {
func newLookupPort(network, service string) (int, error) {
acquireThread()
defer releaseThread()
var stype int32
@ -188,11 +194,11 @@ func newLookupPort(network, service string) (port int, err error) {
var result *syscall.AddrinfoW
e := syscall.GetAddrInfoW(nil, syscall.StringToUTF16Ptr(service), &hints, &result)
if e != nil {
return 0, os.NewSyscallError("GetAddrInfoW", e)
return 0, &DNSError{Err: e.Error(), Name: network + "/" + service}
}
defer syscall.FreeAddrInfoW(result)
if result == nil {
return 0, os.NewSyscallError("LookupPort", syscall.EINVAL)
return 0, &DNSError{Err: syscall.EINVAL.Error(), Name: network + "/" + service}
}
addr := unsafe.Pointer(result.Addr)
switch result.Family {
@ -203,10 +209,10 @@ func newLookupPort(network, service string) (port int, err error) {
a := (*syscall.RawSockaddrInet6)(addr)
return int(syscall.Ntohs(a.Port)), nil
}
return 0, os.NewSyscallError("LookupPort", syscall.EINVAL)
return 0, &DNSError{Err: syscall.EINVAL.Error(), Name: network + "/" + service}
}
func lookupCNAME(name string) (cname string, err error) {
func lookupCNAME(name string) (string, error) {
acquireThread()
defer releaseThread()
var r *syscall.DNSRecord
@ -220,16 +226,16 @@ func lookupCNAME(name string) (cname string, err error) {
return name, nil
}
if e != nil {
return "", os.NewSyscallError("LookupCNAME", e)
return "", &DNSError{Err: e.Error(), Name: name}
}
defer syscall.DnsRecordListFree(r, 1)
resolved := resolveCNAME(syscall.StringToUTF16Ptr(name), r)
cname = syscall.UTF16ToString((*[256]uint16)(unsafe.Pointer(resolved))[:]) + "."
return
cname := syscall.UTF16ToString((*[256]uint16)(unsafe.Pointer(resolved))[:]) + "."
return cname, nil
}
func lookupSRV(service, proto, name string) (cname string, addrs []*SRV, err error) {
func lookupSRV(service, proto, name string) (string, []*SRV, error) {
acquireThread()
defer releaseThread()
var target string
@ -241,78 +247,78 @@ func lookupSRV(service, proto, name string) (cname string, addrs []*SRV, err err
var r *syscall.DNSRecord
e := syscall.DnsQuery(target, syscall.DNS_TYPE_SRV, 0, nil, &r, nil)
if e != nil {
return "", nil, os.NewSyscallError("LookupSRV", e)
return "", nil, &DNSError{Err: e.Error(), Name: target}
}
defer syscall.DnsRecordListFree(r, 1)
addrs = make([]*SRV, 0, 10)
srvs := make([]*SRV, 0, 10)
for _, p := range validRecs(r, syscall.DNS_TYPE_SRV, target) {
v := (*syscall.DNSSRVData)(unsafe.Pointer(&p.Data[0]))
addrs = append(addrs, &SRV{syscall.UTF16ToString((*[256]uint16)(unsafe.Pointer(v.Target))[:]), v.Port, v.Priority, v.Weight})
srvs = append(srvs, &SRV{syscall.UTF16ToString((*[256]uint16)(unsafe.Pointer(v.Target))[:]), v.Port, v.Priority, v.Weight})
}
byPriorityWeight(addrs).sort()
return name, addrs, nil
byPriorityWeight(srvs).sort()
return name, srvs, nil
}
func lookupMX(name string) (mx []*MX, err error) {
func lookupMX(name string) ([]*MX, error) {
acquireThread()
defer releaseThread()
var r *syscall.DNSRecord
e := syscall.DnsQuery(name, syscall.DNS_TYPE_MX, 0, nil, &r, nil)
if e != nil {
return nil, os.NewSyscallError("LookupMX", e)
return nil, &DNSError{Err: e.Error(), Name: name}
}
defer syscall.DnsRecordListFree(r, 1)
mx = make([]*MX, 0, 10)
mxs := make([]*MX, 0, 10)
for _, p := range validRecs(r, syscall.DNS_TYPE_MX, name) {
v := (*syscall.DNSMXData)(unsafe.Pointer(&p.Data[0]))
mx = append(mx, &MX{syscall.UTF16ToString((*[256]uint16)(unsafe.Pointer(v.NameExchange))[:]) + ".", v.Preference})
mxs = append(mxs, &MX{syscall.UTF16ToString((*[256]uint16)(unsafe.Pointer(v.NameExchange))[:]) + ".", v.Preference})
}
byPref(mx).sort()
return mx, nil
byPref(mxs).sort()
return mxs, nil
}
func lookupNS(name string) (ns []*NS, err error) {
func lookupNS(name string) ([]*NS, error) {
acquireThread()
defer releaseThread()
var r *syscall.DNSRecord
e := syscall.DnsQuery(name, syscall.DNS_TYPE_NS, 0, nil, &r, nil)
if e != nil {
return nil, os.NewSyscallError("LookupNS", e)
return nil, &DNSError{Err: e.Error(), Name: name}
}
defer syscall.DnsRecordListFree(r, 1)
ns = make([]*NS, 0, 10)
nss := make([]*NS, 0, 10)
for _, p := range validRecs(r, syscall.DNS_TYPE_NS, name) {
v := (*syscall.DNSPTRData)(unsafe.Pointer(&p.Data[0]))
ns = append(ns, &NS{syscall.UTF16ToString((*[256]uint16)(unsafe.Pointer(v.Host))[:]) + "."})
nss = append(nss, &NS{syscall.UTF16ToString((*[256]uint16)(unsafe.Pointer(v.Host))[:]) + "."})
}
return ns, nil
return nss, nil
}
func lookupTXT(name string) (txt []string, err error) {
func lookupTXT(name string) ([]string, error) {
acquireThread()
defer releaseThread()
var r *syscall.DNSRecord
e := syscall.DnsQuery(name, syscall.DNS_TYPE_TEXT, 0, nil, &r, nil)
if e != nil {
return nil, os.NewSyscallError("LookupTXT", e)
return nil, &DNSError{Err: e.Error(), Name: name}
}
defer syscall.DnsRecordListFree(r, 1)
txt = make([]string, 0, 10)
txts := make([]string, 0, 10)
for _, p := range validRecs(r, syscall.DNS_TYPE_TEXT, name) {
d := (*syscall.DNSTXTData)(unsafe.Pointer(&p.Data[0]))
for _, v := range (*[1 << 10]*uint16)(unsafe.Pointer(&(d.StringArray[0])))[:d.StringCount] {
s := syscall.UTF16ToString((*[1 << 20]uint16)(unsafe.Pointer(v))[:])
txt = append(txt, s)
txts = append(txts, s)
}
}
return
return txts, nil
}
func lookupAddr(addr string) (name []string, err error) {
func lookupAddr(addr string) ([]string, error) {
acquireThread()
defer releaseThread()
arpa, err := reverseaddr(addr)
@ -322,16 +328,16 @@ func lookupAddr(addr string) (name []string, err error) {
var r *syscall.DNSRecord
e := syscall.DnsQuery(arpa, syscall.DNS_TYPE_PTR, 0, nil, &r, nil)
if e != nil {
return nil, os.NewSyscallError("LookupAddr", e)
return nil, &DNSError{Err: e.Error(), Name: addr}
}
defer syscall.DnsRecordListFree(r, 1)
name = make([]string, 0, 10)
ptrs := make([]string, 0, 10)
for _, p := range validRecs(r, syscall.DNS_TYPE_PTR, arpa) {
v := (*syscall.DNSPTRData)(unsafe.Pointer(&p.Data[0]))
name = append(name, syscall.UTF16ToString((*[256]uint16)(unsafe.Pointer(v.Host))[:]))
ptrs = append(ptrs, syscall.UTF16ToString((*[256]uint16)(unsafe.Pointer(v.Host))[:]))
}
return name, nil
return ptrs, nil
}
const dnsSectionMask = 0x0003

View File

@ -416,13 +416,8 @@ func (e *AddrError) Error() string {
return s
}
func (e *AddrError) Temporary() bool {
return false
}
func (e *AddrError) Timeout() bool {
return false
}
func (e *AddrError) Temporary() bool { return false }
func (e *AddrError) Timeout() bool { return false }
type UnknownNetworkError string
@ -441,13 +436,45 @@ type DNSConfigError struct {
Err error
}
func (e *DNSConfigError) Error() string {
return "error reading DNS config: " + e.Err.Error()
}
func (e *DNSConfigError) Error() string { return "error reading DNS config: " + e.Err.Error() }
func (e *DNSConfigError) Timeout() bool { return false }
func (e *DNSConfigError) Temporary() bool { return false }
// Various errors contained in DNSError.
var (
errNoSuchHost = errors.New("no such host")
)
// 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 // if true, timed out; not all timeouts set this
}
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
}
// Timeout reports whether the DNS lookup is known to have timed out.
// This is not always known; a DNS lookup may fail due to a timeout
// and return a DNSError for which Timeout returns false.
func (e *DNSError) Timeout() bool { return e.IsTimeout }
// Temporary reports whether the DNS error is known to be temporary.
// This is not always known; a DNS lookup may fail due to a temporary
// error and return a DNSError for which Temporary returns false.
func (e *DNSError) Temporary() bool { return e.IsTimeout }
type writerOnly struct {
io.Writer
}

View File

@ -18,7 +18,7 @@ func parsePort(net, port string) (int, error) {
}
}
if p < 0 || p > 0xFFFF {
return 0, &AddrError{"invalid port", port}
return 0, &AddrError{Err: "invalid port", Addr: port}
}
return p, nil
}

View File

@ -69,5 +69,5 @@ func goLookupPort(network, service string) (port int, err error) {
return
}
}
return 0, &AddrError{"unknown port", network + "/" + service}
return 0, &AddrError{Err: "unknown port", Addr: network + "/" + service}
}