diff options
Diffstat (limited to 'vendor/google.golang.org/grpc/internal/resolver')
3 files changed, 94 insertions, 49 deletions
diff --git a/vendor/google.golang.org/grpc/internal/resolver/dns/dns_resolver.go b/vendor/google.golang.org/grpc/internal/resolver/dns/dns_resolver.go index 99e1e5b36..b66dcb213 100644 --- a/vendor/google.golang.org/grpc/internal/resolver/dns/dns_resolver.go +++ b/vendor/google.golang.org/grpc/internal/resolver/dns/dns_resolver.go @@ -23,7 +23,6 @@ package dns import ( "context" "encoding/json" - "errors" "fmt" "net" "os" @@ -37,6 +36,7 @@ import ( "google.golang.org/grpc/internal/backoff" "google.golang.org/grpc/internal/envconfig" "google.golang.org/grpc/internal/grpcrand" + "google.golang.org/grpc/internal/resolver/dns/internal" "google.golang.org/grpc/resolver" "google.golang.org/grpc/serviceconfig" ) @@ -47,15 +47,11 @@ var EnableSRVLookups = false var logger = grpclog.Component("dns") -// Globals to stub out in tests. TODO: Perhaps these two can be combined into a -// single variable for testing the resolver? -var ( - newTimer = time.NewTimer - newTimerDNSResRate = time.NewTimer -) - func init() { resolver.Register(NewBuilder()) + internal.TimeAfterFunc = time.After + internal.NewNetResolver = newNetResolver + internal.AddressDialer = addressDialer } const ( @@ -70,23 +66,6 @@ const ( txtAttribute = "grpc_config=" ) -var ( - errMissingAddr = errors.New("dns resolver: missing address") - - // Addresses ending with a colon that is supposed to be the separator - // between host and port is not allowed. E.g. "::" is a valid address as - // it is an IPv6 address (host only) and "[::]:" is invalid as it ends with - // a colon as the host and port separator - errEndsWithColon = errors.New("dns resolver: missing port after port-separator colon") -) - -var ( - defaultResolver netResolver = net.DefaultResolver - // To prevent excessive re-resolution, we enforce a rate limit on DNS - // resolution requests. - minDNSResRate = 30 * time.Second -) - var addressDialer = func(address string) func(context.Context, string, string) (net.Conn, error) { return func(ctx context.Context, network, _ string) (net.Conn, error) { var dialer net.Dialer @@ -94,7 +73,11 @@ var addressDialer = func(address string) func(context.Context, string, string) ( } } -var newNetResolver = func(authority string) (netResolver, error) { +var newNetResolver = func(authority string) (internal.NetResolver, error) { + if authority == "" { + return net.DefaultResolver, nil + } + host, port, err := parseTarget(authority, defaultDNSSvrPort) if err != nil { return nil, err @@ -104,7 +87,7 @@ var newNetResolver = func(authority string) (netResolver, error) { return &net.Resolver{ PreferGo: true, - Dial: addressDialer(authorityWithPort), + Dial: internal.AddressDialer(authorityWithPort), }, nil } @@ -142,13 +125,9 @@ func (b *dnsBuilder) Build(target resolver.Target, cc resolver.ClientConn, opts disableServiceConfig: opts.DisableServiceConfig, } - if target.URL.Host == "" { - d.resolver = defaultResolver - } else { - d.resolver, err = newNetResolver(target.URL.Host) - if err != nil { - return nil, err - } + d.resolver, err = internal.NewNetResolver(target.URL.Host) + if err != nil { + return nil, err } d.wg.Add(1) @@ -161,12 +140,6 @@ func (b *dnsBuilder) Scheme() string { return "dns" } -type netResolver interface { - LookupHost(ctx context.Context, host string) (addrs []string, err error) - LookupSRV(ctx context.Context, service, proto, name string) (cname string, addrs []*net.SRV, err error) - LookupTXT(ctx context.Context, name string) (txts []string, err error) -} - // deadResolver is a resolver that does nothing. type deadResolver struct{} @@ -178,7 +151,7 @@ func (deadResolver) Close() {} type dnsResolver struct { host string port string - resolver netResolver + resolver internal.NetResolver ctx context.Context cancel context.CancelFunc cc resolver.ClientConn @@ -223,29 +196,27 @@ func (d *dnsResolver) watcher() { err = d.cc.UpdateState(*state) } - var timer *time.Timer + var waitTime time.Duration if err == nil { // Success resolving, wait for the next ResolveNow. However, also wait 30 // seconds at the very least to prevent constantly re-resolving. backoffIndex = 1 - timer = newTimerDNSResRate(minDNSResRate) + waitTime = internal.MinResolutionRate select { case <-d.ctx.Done(): - timer.Stop() return case <-d.rn: } } else { // Poll on an error found in DNS Resolver or an error received from // ClientConn. - timer = newTimer(backoff.DefaultExponential.Backoff(backoffIndex)) + waitTime = backoff.DefaultExponential.Backoff(backoffIndex) backoffIndex++ } select { case <-d.ctx.Done(): - timer.Stop() return - case <-timer.C: + case <-internal.TimeAfterFunc(waitTime): } } } @@ -387,7 +358,7 @@ func formatIP(addr string) (addrIP string, ok bool) { // target: ":80" defaultPort: "443" returns host: "localhost", port: "80" func parseTarget(target, defaultPort string) (host, port string, err error) { if target == "" { - return "", "", errMissingAddr + return "", "", internal.ErrMissingAddr } if ip := net.ParseIP(target); ip != nil { // target is an IPv4 or IPv6(without brackets) address @@ -397,7 +368,7 @@ func parseTarget(target, defaultPort string) (host, port string, err error) { if port == "" { // If the port field is empty (target ends with colon), e.g. "[::1]:", // this is an error. - return "", "", errEndsWithColon + return "", "", internal.ErrEndsWithColon } // target has port, i.e ipv4-host:port, [ipv6-host]:port, host-name:port if host == "" { diff --git a/vendor/google.golang.org/grpc/internal/resolver/dns/internal/internal.go b/vendor/google.golang.org/grpc/internal/resolver/dns/internal/internal.go new file mode 100644 index 000000000..c7fc557d0 --- /dev/null +++ b/vendor/google.golang.org/grpc/internal/resolver/dns/internal/internal.go @@ -0,0 +1,70 @@ +/* + * + * Copyright 2023 gRPC authors. + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + * + */ + +// Package internal contains functionality internal to the dns resolver package. +package internal + +import ( + "context" + "errors" + "net" + "time" +) + +// NetResolver groups the methods on net.Resolver that are used by the DNS +// resolver implementation. This allows the default net.Resolver instance to be +// overidden from tests. +type NetResolver interface { + LookupHost(ctx context.Context, host string) (addrs []string, err error) + LookupSRV(ctx context.Context, service, proto, name string) (cname string, addrs []*net.SRV, err error) + LookupTXT(ctx context.Context, name string) (txts []string, err error) +} + +var ( + // ErrMissingAddr is the error returned when building a DNS resolver when + // the provided target name is empty. + ErrMissingAddr = errors.New("dns resolver: missing address") + + // ErrEndsWithColon is the error returned when building a DNS resolver when + // the provided target name ends with a colon that is supposed to be the + // separator between host and port. E.g. "::" is a valid address as it is + // an IPv6 address (host only) and "[::]:" is invalid as it ends with a + // colon as the host and port separator + ErrEndsWithColon = errors.New("dns resolver: missing port after port-separator colon") +) + +// The following vars are overridden from tests. +var ( + // MinResolutionRate is the minimum rate at which re-resolutions are + // allowed. This helps to prevent excessive re-resolution. + MinResolutionRate = 30 * time.Second + + // TimeAfterFunc is used by the DNS resolver to wait for the given duration + // to elapse. In non-test code, this is implemented by time.After. In test + // code, this can be used to control the amount of time the resolver is + // blocked waiting for the duration to elapse. + TimeAfterFunc func(time.Duration) <-chan time.Time + + // NewNetResolver returns the net.Resolver instance for the given target. + NewNetResolver func(string) (NetResolver, error) + + // AddressDialer is the dialer used to dial the DNS server. It accepts the + // Host portion of the URL corresponding to the user's dial target and + // returns a dial function. + AddressDialer func(address string) func(context.Context, string, string) (net.Conn, error) +) diff --git a/vendor/google.golang.org/grpc/internal/resolver/unix/unix.go b/vendor/google.golang.org/grpc/internal/resolver/unix/unix.go index 160911687..27cd81af9 100644 --- a/vendor/google.golang.org/grpc/internal/resolver/unix/unix.go +++ b/vendor/google.golang.org/grpc/internal/resolver/unix/unix.go @@ -61,6 +61,10 @@ func (b *builder) Scheme() string { return b.scheme } +func (b *builder) OverrideAuthority(resolver.Target) string { + return "localhost" +} + type nopResolver struct { } |