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hatecomputers.club
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add integration tests for dns server

This commit is contained in:
Elizabeth 2024-04-02 16:26:39 -06:00
parent 657be66948
commit bcdcc508ef
Signed by: simponic
GPG Key ID: 2909B9A7FF6213EE
3 changed files with 255 additions and 12 deletions
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15
dns/server.go → hcdns/server.go
View File

@ -1,4 +1,4 @@
package dns
package hcdns
import (
"database/sql"
@ -9,7 +9,7 @@ import (
"log"
)
const MAX_RECURSION = 10
const MAX_RECURSION = 15
func resolveInternalCNAMEs(dbConn *sql.DB, domain string, qtype uint16, maxDepth int) ([]dns.RR, error) {
internalCnames, err := database.FindDNSRecords(dbConn, domain, "CNAME")
@ -21,12 +21,14 @@ func resolveInternalCNAMEs(dbConn *sql.DB, domain string, qtype uint16, maxDepth
for _, record := range internalCnames {
cname, err := dns.NewRR(fmt.Sprintf("%s %d IN CNAME %s", record.Name, record.TTL, record.Content))
if err != nil {
log.Println(err)
return nil, err
}
answers = append(answers, cname)
cnameRecursive, err := resolveDNS(dbConn, record.Content, qtype, maxDepth-1)
if err != nil {
log.Println(err)
return nil, err
}
answers = append(answers, cnameRecursive...)
@ -62,13 +64,9 @@ func resolveDNS(dbConn *sql.DB, domain string, qtype uint16, maxDepth int) ([]dn
return nil, err
}
if len(answers) > 0 {
return answers, nil
}
return nil, fmt.Errorf("no records found for %s", domain)
}
type DnsHandler struct {
DnsResolvers []string
DbConn *sql.DB
@ -83,7 +81,9 @@ func (h *DnsHandler) ServeDNS(w dns.ResponseWriter, r *dns.Msg) {
answers, err := resolveDNS(h.DbConn, question.Name, question.Qtype, MAX_RECURSION)
if err != nil {
fmt.Println(err)
continue
msg.SetRcode(r, dns.RcodeServerFailure)
w.WriteMsg(msg)
return
}
msg.Answer = append(msg.Answer, answers...)
}
@ -98,7 +98,6 @@ func (h *DnsHandler) ServeDNS(w dns.ResponseWriter, r *dns.Msg) {
func MakeServer(argv *args.Arguments, dbConn *sql.DB) *dns.Server {
handler := &DnsHandler{
DnsResolvers: argv.DnsRecursion,
DbConn: dbConn,
}
addr := fmt.Sprintf(":%d", argv.DnsPort)

4
main.go
View File

@ -6,7 +6,7 @@ import (
"git.hatecomputers.club/hatecomputers/hatecomputers.club/api"
"git.hatecomputers.club/hatecomputers/hatecomputers.club/args"
"git.hatecomputers.club/hatecomputers/hatecomputers.club/database"
"git.hatecomputers.club/hatecomputers/hatecomputers.club/dns"
"git.hatecomputers.club/hatecomputers/hatecomputers.club/hcdns"
"git.hatecomputers.club/hatecomputers/hatecomputers.club/scheduler"
"github.com/joho/godotenv"
)
@ -52,7 +52,7 @@ func main() {
}
if argv.Dns {
server := dns.MakeServer(argv, dbConn)
server := hcdns.MakeServer(argv, dbConn)
log.Println("🚀🚀 DNS resolver listening on port", argv.DnsPort)
go func() {
err = server.ListenAndServe()

244
test/dns_test.go Normal file
View File

@ -0,0 +1,244 @@
package hcdns
import (
"database/sql"
"os"
"sync"
"testing"
"git.hatecomputers.club/hatecomputers/hatecomputers.club/args"
"git.hatecomputers.club/hatecomputers/hatecomputers.club/database"
"git.hatecomputers.club/hatecomputers/hatecomputers.club/hcdns"
"github.com/miekg/dns"
)
const (
testDBPath = "test.db"
address = "127.0.0.1:8353"
dnsPort = 8353
)
func setup(dbPath string) (*sql.DB, *dns.Server, *sync.WaitGroup) {
testDb := database.MakeConn(&dbPath)
database.Migrate(testDb)
testUser := &database.User{
ID: "test",
}
database.FindOrSaveUser(testDb, testUser)
server := hcdns.MakeServer(&args.Arguments{
DnsPort: dnsPort,
}, testDb)
waitGroup := sync.WaitGroup{}
waitGroup.Add(1)
go func() {
server.ListenAndServe()
waitGroup.Done()
}()
return testDb, server, &waitGroup
}
func destroy(conn *sql.DB, path string) {
conn.Close()
os.Remove(path)
}
func TestWhenCNAMEIsResolved(t *testing.T) {
t.Log("TestWhenCNAMEIsResolved")
testDb, server, _ := setup(testDBPath)
defer destroy(testDb, testDBPath)
defer server.Shutdown()
cname := &database.DNSRecord{
ID: "1",
UserID: "test",
Name: "cname.internal.example.com.",
Type: "CNAME",
Content: "res.example.com.",
TTL: 300,
Internal: true,
}
a := &database.DNSRecord{
ID: "2",
UserID: "test",
Name: "res.example.com.",
Type: "A",
Content: "127.0.0.1",
TTL: 300,
Internal: true,
}
database.SaveDNSRecord(testDb, cname)
database.SaveDNSRecord(testDb, a)
qtype := dns.TypeA
domain := dns.Fqdn(cname.Name)
client := new(dns.Client)
message := new(dns.Msg)
message.SetQuestion(domain, qtype)
in, _, err := client.Exchange(message, address)
if err != nil {
t.Fatal(err)
}
if len(in.Answer) != 2 {
t.Fatalf("expected 2 answers, got %d", len(in.Answer))
}
if in.Answer[0].Header().Name != cname.Name {
t.Fatalf("expected cname.internal.example.com., got %s", in.Answer[0].Header().Name)
}
if in.Answer[1].Header().Name != a.Name {
t.Fatalf("expected res.example.com., got %s", in.Answer[1].Header().Name)
}
if in.Answer[0].(*dns.CNAME).Target != a.Name {
t.Fatalf("expected res.example.com., got %s", in.Answer[0].(*dns.CNAME).Target)
}
if in.Answer[1].(*dns.A).A.String() != a.Content {
t.Fatalf("expected %s, got %s", a.Content, in.Answer[1].(*dns.A).A.String())
}
if in.Answer[0].Header().Rrtype != dns.TypeCNAME {
t.Fatalf("expected CNAME, got %d", in.Answer[0].Header().Rrtype)
}
if in.Answer[1].Header().Rrtype != dns.TypeA {
t.Fatalf("expected A, got %d", in.Answer[1].Header().Rrtype)
}
if int(in.Answer[0].Header().Ttl) != cname.TTL {
t.Fatalf("expected %d, got %d", cname.TTL, in.Answer[0].Header().Ttl)
}
if !in.Authoritative {
t.Fatalf("expected authoritative response")
}
}
func TestWhenNoRecordNxDomain(t *testing.T) {
t.Log("TestWhenNoRecordNxDomain")
testDb, server, _ := setup(testDBPath)
defer destroy(testDb, testDBPath)
defer server.Shutdown()
qtype := dns.TypeA
domain := dns.Fqdn("nonexistant.example.com.")
client := new(dns.Client)
message := new(dns.Msg)
message.SetQuestion(domain, qtype)
in, _, err := client.Exchange(message, address)
if err != nil {
t.Fatal(err)
}
if len(in.Answer) != 0 {
t.Fatalf("expected 0 answers, got %d", len(in.Answer))
}
if in.Rcode != dns.RcodeNameError {
t.Fatalf("expected NXDOMAIN, got %d", in.Rcode)
}
}
func TestWhenUnresolvingCNAME(t *testing.T) {
t.Log("TestWhenUnresolvingCNAME")
testDb, server, _ := setup(testDBPath)
defer destroy(testDb, testDBPath)
defer server.Shutdown()
cname := &database.DNSRecord{
ID: "1",
UserID: "test",
Name: "cname.internal.example.com.",
Type: "CNAME",
Content: "nonexistant.example.com.",
TTL: 300,
Internal: true,
}
database.SaveDNSRecord(testDb, cname)
qtype := dns.TypeA
domain := dns.Fqdn(cname.Name)
client := new(dns.Client)
message := new(dns.Msg)
message.SetQuestion(domain, qtype)
in, _, err := client.Exchange(message, address)
if err != nil {
t.Fatal(err)
}
if len(in.Answer) != 1 {
t.Fatalf("expected 1 answer, got %d", len(in.Answer))
}
if !in.Authoritative {
t.Fatalf("expected authoritative response")
}
if in.Answer[0].Header().Name != cname.Name {
t.Fatalf("expected cname.internal.example.com., got %s", in.Answer[0].Header().Name)
}
if in.Answer[0].Header().Rrtype != dns.TypeCNAME {
t.Fatalf("expected CNAME, got %d", in.Answer[0].Header().Rrtype)
}
if in.Answer[0].(*dns.CNAME).Target != cname.Content {
t.Fatalf("expected nonexistant.example.com., got %s", in.Answer[0].(*dns.CNAME).Target)
}
if in.Rcode == dns.RcodeNameError {
t.Fatalf("expected no NXDOMAIN, got %d", in.Rcode)
}
}
func TestWhenUnresolvingCNAMEWithMaxDepth(t *testing.T) {
t.Log("TestWhenUnresolvingCNAMEWithMaxDepth")
testDb, server, _ := setup(testDBPath)
defer destroy(testDb, testDBPath)
defer server.Shutdown()
cname := &database.DNSRecord{
ID: "1",
UserID: "test",
Name: "cname.internal.example.com.",
Type: "CNAME",
Content: "cname.internal.example.com.",
TTL: 300,
Internal: true,
}
database.SaveDNSRecord(testDb, cname)
qtype := dns.TypeA
domain := dns.Fqdn(cname.Name)
client := new(dns.Client)
message := new(dns.Msg)
message.SetQuestion(domain, qtype)
in, _, err := client.Exchange(message, address)
if err != nil {
t.Fatal(err)
}
if len(in.Answer) > 0 {
t.Fatalf("expected 0 answers, got %d", len(in.Answer))
}
if in.Rcode != dns.RcodeServerFailure {
t.Fatalf("expected SERVFAIL, got %d", in.Rcode)
}
}