daxi20/AdGuardHome
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

cherry-pick: aghnet: imp host validation for system resolvers

Browse Source 
Updates #3022.

Squashed commit of the following:

commit 2f63b4e1765d9c9bfeadafcfa42c9d8741b628e1
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Wed Apr 28 21:29:28 2021 +0300

    aghnet: fix doc

commit efdc1bb2c8959a9f888d558c32c415e6f3678b0c
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Wed Apr 28 21:19:54 2021 +0300

    all: doc changes

commit 8154797095874771bcf04d109644e6ae33fcb470
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Wed Apr 28 21:15:42 2021 +0300

    aghnet: imp host validation for system resolvers
This commit is contained in:
Ainar Garipov
2021-04-28 21:34:18 +03:00
committed by Ainar Garipov
parent 5b9bbce55d
commit d59938d254
4 changed files with 63 additions and 14 deletions
Download Patch File Download Diff File Expand all files Collapse all files

37
internal/aghnet/systemresolvers_others.go
View File

@@ -7,6 +7,7 @@ import (
"errors"
"fmt"
"net"
"strings"
"sync"
"time"
@@ -35,7 +36,7 @@ func (sr *systemResolvers) refresh() (err error) {
_, err = sr.resolver.LookupHost(context.Background(), sr.hostGenFunc())
dnserr := &net.DNSError{}
if errors.As(err, &dnserr) && dnserr.Err == fakeDialErr.Error() {
if errors.As(err, &dnserr) && dnserr.Err == errFakeDial.Error() {
return nil
}
@@ -58,19 +59,43 @@ func newSystemResolvers(refreshIvl time.Duration, hostGenFunc HostGenFunc) (sr S
return s
}
// validateDialedHost validated the host used by resolvers in dialFunc.
func validateDialedHost(host string) (err error) {
defer agherr.Annotate("parsing %q: %w", &err, host)
var ipStr string
parts := strings.Split(host, "%")
switch len(parts) {
case 1:
ipStr = host
case 2:
// Remove the zone and check the IP address part.
ipStr = parts[0]
default:
return errUnexpectedHostFormat
}
if net.ParseIP(ipStr) == nil {
return errBadAddrPassed
}
return nil
}
// dialFunc gets the resolver's address and puts it into internal cache.
func (sr *systemResolvers) dialFunc(_ context.Context, _, address string) (_ net.Conn, err error) {
// Just validate the passed address is a valid IP.
var host string
host, err = SplitHost(address)
if err != nil {
// TODO(e.burkov): Maybe use a structured badAddrPassedErr to
// TODO(e.burkov): Maybe use a structured errBadAddrPassed to
// allow unwrapping of the real error.
return nil, fmt.Errorf("%s: %w", err, badAddrPassedErr)
return nil, fmt.Errorf("%s: %w", err, errBadAddrPassed)
}
if net.ParseIP(host) == nil {
return nil, fmt.Errorf("parsing %q: %w", host, badAddrPassedErr)
err = validateDialedHost(host)
if err != nil {
return nil, fmt.Errorf("validating dialed host: %w", err)
}
sr.addrsLock.Lock()
@@ -78,7 +103,7 @@ func (sr *systemResolvers) dialFunc(_ context.Context, _, address string) (_ net
sr.addrs.Add(host)
return nil, fakeDialErr
return nil, errFakeDial
}
func (sr *systemResolvers) Get() (rs []string) {