//go:build (linux && !android) || freebsd
package dns
import (
"os"
"path/filepath"
"testing"
"github.com/stretchr/testify/assert"
)
func Test_parseResolvConf(t *testing.T) {
testCases := []struct {
input string
expectedSearch []string
expectedNS []string
expectedOther []string
}{
{
input: `domain example.org
search example.org
nameserver 192.168.0.1
`,
expectedSearch: []string{"example.org"},
expectedNS: []string{"192.168.0.1"},
expectedOther: []string{},
},
{
input: `# This is /run/systemd/resolve/resolv.conf managed by man:systemd-resolved(8).
# Do not edit.
#
# This file might be symlinked as /etc/resolv.conf. If you're looking at
# /etc/resolv.conf and seeing this text, you have followed the symlink.
#
# This is a dynamic resolv.conf file for connecting local clients directly to
# all known uplink DNS servers. This file lists all configured search domains.
#
# Third party programs should typically not access this file directly, but only
# through the symlink at /etc/resolv.conf. To manage man:resolv.conf(5) in a
# different way, replace this symlink by a static file or a different symlink.
#
# See man:systemd-resolved.service(8) for details about the supported modes of
# operation for /etc/resolv.conf.
nameserver 192.168.2.1
nameserver 100.81.99.197
search netbird.cloud
`,
expectedSearch: []string{"netbird.cloud"},
expectedNS: []string{"192.168.2.1", "100.81.99.197"},
expectedOther: []string{},
},
{
input: `# This is /run/systemd/resolve/resolv.conf managed by man:systemd-resolved(8).
# Do not edit.
#
# This file might be symlinked as /etc/resolv.conf. If you're looking at
# /etc/resolv.conf and seeing this text, you have followed the symlink.
#
# This is a dynamic resolv.conf file for connecting local clients directly to
# all known uplink DNS servers. This file lists all configured search domains.
#
# Third party programs should typically not access this file directly, but only
# through the symlink at /etc/resolv.conf. To manage man:resolv.conf(5) in a
# different way, replace this symlink by a static file or a different symlink.
#
# See man:systemd-resolved.service(8) for details about the supported modes of
# operation for /etc/resolv.conf.
nameserver 192.168.2.1
nameserver 100.81.99.197
search netbird.cloud
options debug
`,
expectedSearch: []string{"netbird.cloud"},
expectedNS: []string{"192.168.2.1", "100.81.99.197"},
expectedOther: []string{"options debug"},
},
}
for _, testCase := range testCases {
testCase := testCase
t.Run("test", func(t *testing.T) {
t.Parallel()
tmpResolvConf := filepath.Join(t.TempDir(), "resolv.conf")
err := os.WriteFile(tmpResolvConf, []byte(testCase.input), 0644)
if err != nil {
t.Fatal(err)
}
cfg, err := parseResolvConfFile(tmpResolvConf)
if err != nil {
t.Fatal(err)
}
ok := compareLists(cfg.searchDomains, testCase.expectedSearch)
if !ok {
t.Errorf("invalid parse result for search domains, expected: %v, got: %v", testCase.expectedSearch, cfg.searchDomains)
}
ok = compareLists(cfg.nameServers, testCase.expectedNS)
if !ok {
t.Errorf("invalid parse result for ns domains, expected: %v, got: %v", testCase.expectedNS, cfg.nameServers)
}
ok = compareLists(cfg.others, testCase.expectedOther)
if !ok {
t.Errorf("invalid parse result for others, expected: %v, got: %v", testCase.expectedOther, cfg.others)
}
})
}
}
func compareLists(search []string, search2 []string) bool {
if len(search) != len(search2) {
return false
}
for i, v := range search {
if v != search2[i] {
return false
}
}
return true
}
func Test_emptyFile(t *testing.T) {
cfg, err := parseResolvConfFile("/tmp/nothing")
if err == nil {
t.Errorf("expected error, got nil")
}
if len(cfg.others) != 0 || len(cfg.searchDomains) != 0 || len(cfg.nameServers) != 0 {
t.Errorf("expected empty config, got %v", cfg)
}
}
func Test_symlink(t *testing.T) {
input := `# This is /run/systemd/resolve/resolv.conf managed by man:systemd-resolved(8).
# Do not edit.
#
# This file might be symlinked as /etc/resolv.conf. If you're looking at
# /etc/resolv.conf and seeing this text, you have followed the symlink.
#
# This is a dynamic resolv.conf file for connecting local clients directly to
# all known uplink DNS servers. This file lists all configured search domains.
#
# Third party programs should typically not access this file directly, but only
# through the symlink at /etc/resolv.conf. To manage man:resolv.conf(5) in a
# different way, replace this symlink by a static file or a different symlink.
#
# See man:systemd-resolved.service(8) for details about the supported modes of
# operation for /etc/resolv.conf.
nameserver 192.168.0.1
`
tmpResolvConf := filepath.Join(t.TempDir(), "resolv.conf")
err := os.WriteFile(tmpResolvConf, []byte(input), 0644)
if err != nil {
t.Fatal(err)
}
tmpLink := filepath.Join(t.TempDir(), "symlink")
err = os.Symlink(tmpResolvConf, tmpLink)
if err != nil {
t.Fatal(err)
}
cfg, err := parseResolvConfFile(tmpLink)
if err != nil {
t.Fatal(err)
}
if len(cfg.nameServers) != 1 {
t.Errorf("unexpected resolv.conf content: %v", cfg)
}
}
func TestPrepareOptionsWithTimeout(t *testing.T) {
tests := []struct {
name string
others []string
timeout int
attempts int
expected []string
}{
{
name: "Append new options with timeout and attempts",
others: []string{"some config"},
timeout: 2,
attempts: 2,
expected: []string{"some config", "options timeout:2 attempts:2"},
},
{
name: "Modify existing options to exclude rotate and include timeout and attempts",
others: []string{"some config", "options rotate someother"},
timeout: 3,
attempts: 2,
expected: []string{"some config", "options attempts:2 timeout:3 someother"},
},
{
name: "Existing options with timeout and attempts are updated",
others: []string{"some config", "options timeout:4 attempts:3"},
timeout: 5,
attempts: 4,
expected: []string{"some config", "options timeout:5 attempts:4"},
},
{
name: "Modify existing options, add missing attempts before timeout",
others: []string{"some config", "options timeout:4"},
timeout: 4,
attempts: 3,
expected: []string{"some config", "options attempts:3 timeout:4"},
},
}
for _, tc := range tests {
t.Run(tc.name, func(t *testing.T) {
result := prepareOptionsWithTimeout(tc.others, tc.timeout, tc.attempts)
assert.Equal(t, tc.expected, result)
})
}
}
func TestRemoveFirstNbNameserver(t *testing.T) {
testCases := []struct {
name string
content string
ipToRemove string
expected string
}{
{
name: "Unrelated nameservers with comments and options",
content: `# This is a comment
options rotate
nameserver 1.1.1.1
# Another comment
nameserver 8.8.4.4
search example.com`,
ipToRemove: "9.9.9.9",
expected: `# This is a comment
options rotate
nameserver 1.1.1.1
# Another comment
nameserver 8.8.4.4
search example.com`,
},
{
name: "First nameserver matches",
content: `search example.com
nameserver 9.9.9.9
# oof, a comment
nameserver 8.8.4.4
options attempts:5`,
ipToRemove: "9.9.9.9",
expected: `search example.com
# oof, a comment
nameserver 8.8.4.4
options attempts:5`,
},
{
name: "Target IP not the first nameserver",
// nolint:dupword
content: `# Comment about the first nameserver
nameserver 8.8.4.4
# Comment before our target
nameserver 9.9.9.9
options timeout:2`,
ipToRemove: "9.9.9.9",
// nolint:dupword
expected: `# Comment about the first nameserver
nameserver 8.8.4.4
# Comment before our target
nameserver 9.9.9.9
options timeout:2`,
},
{
name: "Only nameserver matches",
content: `options debug
nameserver 9.9.9.9
search localdomain`,
ipToRemove: "9.9.9.9",
expected: `options debug
nameserver 9.9.9.9
search localdomain`,
},
}
for _, tc := range testCases {
t.Run(tc.name, func(t *testing.T) {
tempDir := t.TempDir()
tempFile := filepath.Join(tempDir, "resolv.conf")
err := os.WriteFile(tempFile, []byte(tc.content), 0644)
assert.NoError(t, err)
err = removeFirstNbNameserver(tempFile, tc.ipToRemove)
assert.NoError(t, err)
content, err := os.ReadFile(tempFile)
assert.NoError(t, err)
assert.Equal(t, tc.expected, string(content), "The resulting content should match the expected output.")
})
}
}