Pull request: all: imp dhcp client hostname normalization

Updates #2952.
Updates #2978.

Squashed commit of the following:

commit 20e379b94ccf8140fd9056429315945c17f711a5
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Mon Apr 19 15:58:37 2021 +0300

    all: imp naming

commit ed300e0563fa37e161406a97991b26a89e23903a
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Mon Apr 19 15:43:09 2021 +0300

    all: imp dhcp client hostname normalization
This commit is contained in:
Ainar Garipov
2021-04-19 16:04:40 +03:00
parent 91304663b7
commit d707f8b1d1
6 changed files with 127 additions and 73 deletions

View File

@@ -558,34 +558,45 @@ func (o *optFQDN) ToBytes() []byte {
return b
}
// normalizeHostname normalizes and validates a hostname sent by the client.
//
// TODO(a.garipov): Add client hostname uniqueness validations and rename the
// method to validateHostname.
func (s *v4Server) normalizeHostname(name string) (norm string, err error) {
// normalizeHostname normalizes a hostname sent by the client.
func normalizeHostname(name string) (norm string, err error) {
if name == "" {
return "", nil
}
// Some devices send hostnames with spaces, but we still want to accept
// them, so replace them with dashes and issue a warning.
//
// See https://github.com/AdguardTeam/AdGuardHome/issues/2946.
norm = strings.ReplaceAll(name, " ", "-")
state := "non-normalized"
if name != norm {
log.Debug("dhcpv4: normalized hostname %q into %q", name, norm)
state = "normalized"
parts := strings.FieldsFunc(name, func(c rune) (ok bool) {
return c != '.' && !aghnet.IsValidHostOuterRune(c)
})
if len(parts) == 0 {
return "", fmt.Errorf("normalizing hostname %q: no valid parts", name)
}
err = aghnet.ValidateDomainName(norm)
if err != nil {
return "", fmt.Errorf("validating %s hostname: %w", state, err)
}
norm = strings.Join(parts, "-")
norm = strings.TrimSuffix(norm, "-")
return norm, nil
}
// validateHostname validates a hostname sent by the client.
func (s *v4Server) validateHostname(name string) (err error) {
if name == "" {
return nil
}
err = aghnet.ValidateDomainName(name)
if err != nil {
return fmt.Errorf("validating hostname: %w", err)
}
// TODO(a.garipov): Add client hostname uniqueness validation either
// here or into method processRequest. This is not as easy as it might
// look like, because the process of adding and releasing a lease is
// currently non-straightforward.
return nil
}
// Process Request request and return lease
// Return false if we don't need to reply
func (s *v4Server) processRequest(req, resp *dhcpv4.DHCPv4) (lease *Lease, ok bool) {
@@ -634,16 +645,29 @@ func (s *v4Server) processRequest(req, resp *dhcpv4.DHCPv4) (lease *Lease, ok bo
}
if !lease.IsStatic() {
cliHostname := req.HostName()
var hostname string
hostname, err = s.normalizeHostname(req.HostName())
hostname, err = normalizeHostname(cliHostname)
if err != nil {
log.Error("dhcpv4: cannot normalize hostname for %s: %s", mac, err)
return nil, false
// Go on and assign a hostname made from the IP.
}
if hostname != "" && cliHostname != hostname {
log.Debug("dhcpv4: normalized hostname %q into %q", cliHostname, hostname)
}
err = s.validateHostname(hostname)
if err != nil {
log.Error("dhcpv4: validating hostname for %s: %s", mac, err)
// Go on and assign a hostname made from the IP.
}
if hostname == "" {
hostname = aghnet.GenerateHostName(reqIP)
hostname = aghnet.GenerateHostname(reqIP)
}
lease.Hostname = hostname

View File

@@ -290,7 +290,7 @@ func TestV4DynamicLease_Get(t *testing.T) {
})
}
func TestV4Server_normalizeHostname(t *testing.T) {
func TestNormalizeHostname(t *testing.T) {
testCases := []struct {
name string
hostname string
@@ -312,24 +312,35 @@ func TestV4Server_normalizeHostname(t *testing.T) {
wantErrMsg: "",
want: "my-device-01",
}, {
name: "error",
hostname: "!!!",
wantErrMsg: `validating non-normalized hostname: ` +
`invalid domain name label at index 0: ` +
`invalid char '!' at index 0 in "!!!"`,
want: "",
name: "success_underscores",
hostname: "my_device_01",
wantErrMsg: "",
want: "my-device-01",
}, {
name: "error_spaces",
hostname: "! ! !",
wantErrMsg: `validating normalized hostname: ` +
`invalid domain name label at index 0: ` +
`invalid char '!' at index 0 in "!-!-!"`,
want: "",
name: "error_part",
hostname: "device !!!",
wantErrMsg: "",
want: "device",
}, {
name: "error_part_spaces",
hostname: "device ! ! !",
wantErrMsg: "",
want: "device",
}, {
name: "error",
hostname: "!!!",
wantErrMsg: `normalizing hostname "!!!": no valid parts`,
want: "",
}, {
name: "error_spaces",
hostname: "! ! !",
wantErrMsg: `normalizing hostname "! ! !": no valid parts`,
want: "",
}}
for _, tc := range testCases {
t.Run(tc.name, func(t *testing.T) {
got, err := (&v4Server{}).normalizeHostname(tc.hostname)
got, err := normalizeHostname(tc.hostname)
if tc.wantErrMsg == "" {
assert.NoError(t, err)
} else {