internal recursive dns server #2

Merged
simponic merged 1 commits from dns_server into main 2024-03-28 16:58:08 -04:00
11 changed files with 325 additions and 52 deletions

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@ -11,4 +11,4 @@ RUN go build -o /app/hatecomputers
EXPOSE 8080
CMD ["/app/hatecomputers", "--server", "--migrate", "--port", "8080", "--template-path", "/app/templates", "--database-path", "/app/db/hatecomputers.db", "--static-path", "/app/static", "--scheduler"]
CMD ["/app/hatecomputers", "--server", "--migrate", "--port", "8080", "--template-path", "/app/templates", "--database-path", "/app/db/hatecomputers.db", "--static-path", "/app/static", "--scheduler", "--dns", "--dns-port", "8053", "--dns-recursion", "1.1.1.1:53,1.0.0.1:53"]

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@ -1,6 +1,7 @@
package api
import (
"database/sql"
"log"
"net/http"
"strconv"
@ -8,16 +9,31 @@ import (
"git.hatecomputers.club/hatecomputers/hatecomputers.club/adapters/cloudflare"
"git.hatecomputers.club/hatecomputers/hatecomputers.club/database"
"git.hatecomputers.club/hatecomputers/hatecomputers.club/utils"
)
const MAX_USER_RECORDS = 20
const MAX_USER_RECORDS = 65
type FormError struct {
Errors []string
}
func userCanFuckWithDNSRecord(user *database.User, record *database.DNSRecord) bool {
return user.ID == record.UserID && (record.Name == user.Username || strings.HasSuffix(record.Name, "."+user.Username))
func userCanFuckWithDNSRecord(dbConn *sql.DB, user *database.User, record *database.DNSRecord) bool {
ownedByUser := (user.ID == record.UserID)
if !record.Internal {
publicallyOwnedByUser := (record.Name == user.Username || strings.HasSuffix(record.Name, "."+user.Username))
return ownedByUser && publicallyOwnedByUser
}
owner, err := database.FindFirstDomainOwnerId(dbConn, record.Name)
if err != nil {
log.Println(err)
return false
}
userIsOwnerOfDomain := owner == user.ID
return ownedByUser && userIsOwnerOfDomain
}
func ListDNSRecordsContinuation(context *RequestContext, req *http.Request, resp http.ResponseWriter) ContinuationChain {
@ -40,8 +56,15 @@ func CreateDNSRecordContinuation(context *RequestContext, req *http.Request, res
Errors: []string{},
}
internal := req.FormValue("internal") == "on"
name := req.FormValue("name")
if internal && !strings.HasSuffix(name, ".") {
name += "."
}
recordType := req.FormValue("type")
recordType = strings.ToUpper(recordType)
recordContent := req.FormValue("content")
ttl := req.FormValue("ttl")
ttlNum, err := strconv.Atoi(ttl)
@ -55,6 +78,7 @@ func CreateDNSRecordContinuation(context *RequestContext, req *http.Request, res
Type: recordType,
Content: recordContent,
TTL: ttlNum,
Internal: internal,
}
dnsRecords, err := database.GetUserDNSRecords(context.DBConn, context.User.ID)
@ -67,11 +91,14 @@ func CreateDNSRecordContinuation(context *RequestContext, req *http.Request, res
formErrors.Errors = append(formErrors.Errors, "max records reached")
}
if !userCanFuckWithDNSRecord(context.User, dnsRecord) {
formErrors.Errors = append(formErrors.Errors, "'name' must end with "+context.User.Username)
if !userCanFuckWithDNSRecord(context.DBConn, context.User, dnsRecord) {
formErrors.Errors = append(formErrors.Errors, "'name' must end with "+context.User.Username+" or you must be a domain owner for internal domains")
}
if len(formErrors.Errors) == 0 {
if dnsRecord.Internal {
dnsRecord.ID = utils.RandomId()
} else {
cloudflareRecordId, err := cloudflare.CreateDNSRecord(context.Args.CloudflareZone, context.Args.CloudflareToken, dnsRecord)
if err != nil {
log.Println(err)
@ -80,6 +107,7 @@ func CreateDNSRecordContinuation(context *RequestContext, req *http.Request, res
dnsRecord.ID = cloudflareRecordId
}
}
if len(formErrors.Errors) == 0 {
_, err := database.SaveDNSRecord(context.DBConn, dnsRecord)
@ -113,17 +141,19 @@ func DeleteDNSRecordContinuation(context *RequestContext, req *http.Request, res
return failure(context, req, resp)
}
if !userCanFuckWithDNSRecord(context.User, record) {
if !userCanFuckWithDNSRecord(context.DBConn, context.User, record) {
resp.WriteHeader(http.StatusUnauthorized)
return failure(context, req, resp)
}
if !record.Internal {
err = cloudflare.DeleteDNSRecord(context.Args.CloudflareZone, context.Args.CloudflareToken, recordId)
if err != nil {
log.Println(err)
resp.WriteHeader(http.StatusInternalServerError)
return failure(context, req, resp)
}
}
err = database.DeleteDNSRecord(context.DBConn, recordId)
if err != nil {

View File

@ -15,25 +15,35 @@ type Arguments struct {
StaticPath string
CloudflareToken string
CloudflareZone string
Port int
Server bool
Migrate bool
Scheduler bool
Port int
Server bool
OauthConfig *oauth2.Config
OauthUserInfoURI string
Dns bool
DnsRecursion []string
DnsPort int
}
func GetArgs() (*Arguments, error) {
port := flag.Int("port", 8080, "Port to listen on")
databasePath := flag.String("database-path", "./hatecomputers.db", "Path to the SQLite database")
templatePath := flag.String("template-path", "./templates", "Path to the template directory")
staticPath := flag.String("static-path", "./static", "Path to the static directory")
scheduler := flag.Bool("scheduler", false, "Run scheduled jobs via cron")
server := flag.Bool("server", false, "Run the server")
migrate := flag.Bool("migrate", false, "Run the migrations")
port := flag.Int("port", 8080, "Port to listen on")
server := flag.Bool("server", false, "Run the server")
dns := flag.Bool("dns", false, "Run DNS resolver")
dnsRecursion := flag.String("dns-recursion", "1.1.1.1:53,1.0.0.1:53", "Comma separated list of DNS resolvers")
dnsPort := flag.Int("dns-port", 8053, "Port to listen on for DNS resolver")
flag.Parse()
cloudflareToken := os.Getenv("CLOUDFLARE_TOKEN")
@ -86,6 +96,9 @@ func GetArgs() (*Arguments, error) {
Server: *server,
Migrate: *migrate,
Scheduler: *scheduler,
Dns: *dns,
DnsRecursion: strings.Split(*dnsRecursion, ","),
DnsPort: *dnsPort,
OauthConfig: oauthConfig,
OauthUserInfoURI: oauthUserInfoURI,

View File

@ -2,8 +2,10 @@ package database
import (
"database/sql"
"fmt"
_ "github.com/mattn/go-sqlite3"
"log"
"strings"
"time"
)
@ -14,6 +16,7 @@ type DNSRecord struct {
Type string `json:"type"`
Content string `json:"content"`
TTL int `json:"ttl"`
Internal bool `json:"internal"`
CreatedAt time.Time `json:"created_at"`
}
@ -29,7 +32,7 @@ func GetUserDNSRecords(db *sql.DB, userID string) ([]DNSRecord, error) {
var records []DNSRecord
for rows.Next() {
var record DNSRecord
err := rows.Scan(&record.ID, &record.UserID, &record.Name, &record.Type, &record.Content, &record.TTL, &record.CreatedAt)
err := rows.Scan(&record.ID, &record.UserID, &record.Name, &record.Type, &record.Content, &record.TTL, &record.Internal, &record.CreatedAt)
if err != nil {
return nil, err
}
@ -43,7 +46,7 @@ func SaveDNSRecord(db *sql.DB, record *DNSRecord) (*DNSRecord, error) {
log.Println("saving dns record", record)
record.CreatedAt = time.Now()
_, err := db.Exec("INSERT OR REPLACE INTO dns_records (id, user_id, name, type, content, ttl, created_at) VALUES (?, ?, ?, ?, ?, ?, ?)", record.ID, record.UserID, record.Name, record.Type, record.Content, record.TTL, record.CreatedAt)
_, err := db.Exec("INSERT OR REPLACE INTO dns_records (id, user_id, name, type, content, ttl, internal, created_at) VALUES (?, ?, ?, ?, ?, ?, ?, ?)", record.ID, record.UserID, record.Name, record.Type, record.Content, record.TTL, record.Internal, record.CreatedAt)
if err != nil {
return nil, err
@ -56,7 +59,7 @@ func GetDNSRecord(db *sql.DB, recordID string) (*DNSRecord, error) {
row := db.QueryRow("SELECT * FROM dns_records WHERE id = ?", recordID)
var record DNSRecord
err := row.Scan(&record.ID, &record.UserID, &record.Name, &record.Type, &record.Content, &record.TTL, &record.CreatedAt)
err := row.Scan(&record.ID, &record.UserID, &record.Name, &record.Type, &record.Content, &record.TTL, &record.Internal, &record.CreatedAt)
if err != nil {
return nil, err
}
@ -72,3 +75,53 @@ func DeleteDNSRecord(db *sql.DB, recordID string) error {
}
return nil
}
func FindFirstDomainOwnerId(db *sql.DB, domain string) (string, error) {
log.Println("finding domain owner for", domain)
ownerID := ""
parts := strings.Split(domain, ".")
if len(parts) < 2 {
return ownerID, fmt.Errorf("invalid domain; must have at least two parts")
}
for ownerID == "" {
row := db.QueryRow("SELECT user_id FROM domain_owners WHERE domain = ?", strings.Join(parts, "."))
err := row.Scan(&ownerID)
if err != nil {
if len(parts) == 1 {
break
}
parts = parts[1:]
}
}
if ownerID == "" {
return ownerID, fmt.Errorf("no owner found for domain")
}
return ownerID, nil
}
func FindDNSRecords(dbConn *sql.DB, name string, qtype string) ([]DNSRecord, error) {
log.Println("finding dns record(s) for", name, qtype)
rows, err := dbConn.Query("SELECT * FROM dns_records WHERE name = ? AND type = ?", name, qtype)
if err != nil {
return nil, err
}
defer rows.Close()
var records []DNSRecord
for rows.Next() {
var record DNSRecord
err := rows.Scan(&record.ID, &record.UserID, &record.Name, &record.Type, &record.Content, &record.TTL, &record.Internal, &record.CreatedAt)
if err != nil {
return nil, err
}
records = append(records, record)
}
return records, nil
}

View File

@ -57,6 +57,7 @@ func MigrateDNSRecords(dbConn *sql.DB) (*sql.DB, error) {
type TEXT NOT NULL,
content TEXT NOT NULL,
ttl INTEGER NOT NULL,
internal BOOLEAN NOT NULL,
created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
FOREIGN KEY (user_id) REFERENCES users (id) ON DELETE CASCADE);`)
if err != nil {
@ -65,6 +66,26 @@ func MigrateDNSRecords(dbConn *sql.DB) (*sql.DB, error) {
return dbConn, nil
}
func MigrateDomainOwners(dbConn *sql.DB) (*sql.DB, error) {
log.Println("migrating domain_owners table")
_, err := dbConn.Exec(`CREATE TABLE IF NOT EXISTS domain_owners (
user_id INTEGER NOT NULL,
domain TEXT NOT NULL,
created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
FOREIGN KEY (user_id) REFERENCES users (id) ON DELETE CASCADE
);`)
if err != nil {
return dbConn, err
}
_, err = dbConn.Exec(`CREATE UNIQUE INDEX IF NOT EXISTS idx_domain_owners_domain ON domain_owners (domain);`)
if err != nil {
return dbConn, err
}
return dbConn, nil
}
func MigrateUserSessions(dbConn *sql.DB) (*sql.DB, error) {
log.Println("migrating user_sessions table")
@ -88,6 +109,7 @@ func Migrate(dbConn *sql.DB) (*sql.DB, error) {
MigrateUsers,
MigrateUserSessions,
MigrateApiKeys,
MigrateDomainOwners,
MigrateDNSRecords,
}

110
dns/server.go Normal file
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@ -0,0 +1,110 @@
package dns
import (
"database/sql"
"fmt"
"git.hatecomputers.club/hatecomputers/hatecomputers.club/args"
"git.hatecomputers.club/hatecomputers/hatecomputers.club/database"
"github.com/miekg/dns"
"log"
)
const MAX_RECURSION = 10
func resolveRecursive(dbConn *sql.DB, dnsResolvers []string, domain string, qtype uint16, maxDepth int) ([]dns.RR, error) {
if maxDepth == 0 {
return nil, fmt.Errorf("too much recursion")
}
internalCnames, err := database.FindDNSRecords(dbConn, domain, "CNAME")
if err != nil {
return nil, err
}
answers := []dns.RR{}
for _, record := range internalCnames {
cnameRecursive, _ := resolveRecursive(dbConn, dnsResolvers, record.Content, qtype, maxDepth-1)
answers = append(answers, cnameRecursive...)
}
qtypeName := dns.TypeToString[qtype]
if qtypeName == "" {
return nil, fmt.Errorf("invalid query type %d", qtype)
}
typeDnsRecords, err := database.FindDNSRecords(dbConn, domain, qtypeName)
if err != nil {
return nil, err
}
for _, record := range typeDnsRecords {
answer, err := dns.NewRR(fmt.Sprintf("%s %d IN %s %s", record.Name, record.TTL, record.Type, record.Content))
if err != nil {
return nil, err
}
answers = append(answers, answer)
}
if len(answers) > 0 {
// base case; we found the answer
return answers, nil
}
message := new(dns.Msg)
message.SetQuestion(dns.Fqdn(domain), qtype)
message.RecursionDesired = true
client := new(dns.Client)
i := 0
in, _, err := client.Exchange(message, dnsResolvers[i])
for err != nil {
i += 1
if i == len(dnsResolvers) {
log.Println(err)
return nil, err
}
in, _, err = client.Exchange(message, dnsResolvers[i])
}
answers = append(answers, in.Answer...)
return answers, nil
}
type DnsHandler struct {
DnsResolvers []string
DbConn *sql.DB
}
func (h *DnsHandler) ServeDNS(w dns.ResponseWriter, r *dns.Msg) {
msg := new(dns.Msg)
msg.SetReply(r)
msg.Authoritative = true
for _, question := range r.Question {
answers, err := resolveRecursive(h.DbConn, h.DnsResolvers, question.Name, question.Qtype, MAX_RECURSION)
if err != nil {
fmt.Println(err)
continue
}
msg.Answer = append(msg.Answer, answers...)
}
log.Println(msg.Answer)
w.WriteMsg(msg)
}
func MakeServer(argv *args.Arguments, dbConn *sql.DB) *dns.Server {
handler := &DnsHandler{
DnsResolvers: argv.DnsRecursion,
DbConn: dbConn,
}
addr := fmt.Sprintf(":%d", argv.DnsPort)
return &dns.Server{
Addr: addr,
Net: "udp",
Handler: handler,
UDPSize: 65535,
ReusePort: true,
}
}

4
go.mod
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@ -6,6 +6,7 @@ require (
github.com/go-co-op/gocron v1.37.0
github.com/joho/godotenv v1.5.1
github.com/mattn/go-sqlite3 v1.14.22
github.com/miekg/dns v1.1.58
golang.org/x/oauth2 v0.18.0
)
@ -14,7 +15,10 @@ require (
github.com/google/uuid v1.4.0 // indirect
github.com/robfig/cron/v3 v3.0.1 // indirect
go.uber.org/atomic v1.9.0 // indirect
golang.org/x/mod v0.14.0 // indirect
golang.org/x/net v0.22.0 // indirect
golang.org/x/sys v0.18.0 // indirect
golang.org/x/tools v0.17.0 // indirect
google.golang.org/appengine v1.6.7 // indirect
google.golang.org/protobuf v1.31.0 // indirect
)

10
go.sum
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@ -23,6 +23,8 @@ github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
github.com/kr/text v0.2.0/go.mod h1:eLer722TekiGuMkidMxC/pM04lWEeraHUUmBw8l2grE=
github.com/mattn/go-sqlite3 v1.14.22 h1:2gZY6PC6kBnID23Tichd1K+Z0oS6nE/XwU+Vz/5o4kU=
github.com/mattn/go-sqlite3 v1.14.22/go.mod h1:Uh1q+B4BYcTPb+yiD3kU8Ct7aC0hY9fxUwlHK0RXw+Y=
github.com/miekg/dns v1.1.58 h1:ca2Hdkz+cDg/7eNF6V56jjzuZ4aCAE+DbVkILdQWG/4=
github.com/miekg/dns v1.1.58/go.mod h1:Ypv+3b/KadlvW9vJfXOTf300O4UqaHFzFCuHz+rPkBY=
github.com/pkg/diff v0.0.0-20210226163009-20ebb0f2a09e/go.mod h1:pJLUxLENpZxwdsKMEsNbx1VGcRFpLqf3715MtcvvzbA=
github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
@ -41,15 +43,23 @@ github.com/stretchr/testify v1.8.2/go.mod h1:w2LPCIKwWwSfY2zedu0+kehJoqGctiVI29o
go.uber.org/atomic v1.9.0 h1:ECmE8Bn/WFTYwEW/bpKD3M8VtR/zQVbavAoalC1PYyE=
go.uber.org/atomic v1.9.0/go.mod h1:fEN4uk6kAWBTFdckzkM89CLk9XfWZrxpCo0nPH17wJc=
golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
golang.org/x/mod v0.14.0 h1:dGoOF9QVLYng8IHTm7BAyWqCqSheQ5pYWGhzW00YJr0=
golang.org/x/mod v0.14.0/go.mod h1:hTbmBsO62+eylJbnUtE2MGJUyE7QWk4xUqPFrRgJ+7c=
golang.org/x/net v0.0.0-20190603091049-60506f45cf65/go.mod h1:HSz+uSET+XFnRR8LxR5pz3Of3rY3CfYBVs4xY44aLks=
golang.org/x/net v0.22.0 h1:9sGLhx7iRIHEiX0oAJ3MRZMUCElJgy7Br1nO+AMN3Tc=
golang.org/x/net v0.22.0/go.mod h1:JKghWKKOSdJwpW2GEx0Ja7fmaKnMsbu+MWVZTokSYmg=
golang.org/x/oauth2 v0.18.0 h1:09qnuIAgzdx1XplqJvW6CQqMCtGZykZWcXzPMPUusvI=
golang.org/x/oauth2 v0.18.0/go.mod h1:Wf7knwG0MPoWIMMBgFlEaSUDaKskp0dCfrlJRJXbBi8=
golang.org/x/sync v0.6.0 h1:5BMeUDZ7vkXGfEr1x9B4bRcTH4lpkTkpdh0T/J+qjbQ=
golang.org/x/sync v0.6.0/go.mod h1:Czt+wKu1gCyEFDUtn0jG5QVvpJ6rzVqr5aXyt9drQfk=
golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
golang.org/x/sys v0.18.0 h1:DBdB3niSjOA/O0blCZBqDefyWNYveAYMNF1Wum0DYQ4=
golang.org/x/sys v0.18.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
golang.org/x/text v0.3.2/go.mod h1:bEr9sfX3Q8Zfm5fL9x+3itogRgK3+ptLWKqgva+5dAk=
golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
golang.org/x/tools v0.17.0 h1:FvmRgNOcs3kOa+T20R1uhfP9F6HgG2mfxDv1vrx1Htc=
golang.org/x/tools v0.17.0/go.mod h1:xsh6VxdV005rRVaS6SSAf9oiAqljS7UZUacMZ8Bnsps=
golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
google.golang.org/appengine v1.6.7 h1:FZR1q0exgwxzPzp/aF+VccGrSfxfPpkBqjIIEq3ru6c=
google.golang.org/appengine v1.6.7/go.mod h1:8WjMMxjGQR8xUklV/ARdw2HLXBOI7O7uCIDZVag1xfc=

20
main.go
View File

@ -6,6 +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/scheduler"
"github.com/joho/godotenv"
)
@ -40,10 +41,27 @@ func main() {
if argv.Server {
server := api.MakeServer(argv, dbConn)
log.Println("🚀🚀 API listening on port", argv.Port)
go func() {
err = server.ListenAndServe()
if err != nil {
log.Fatal(err)
}
log.Println("🚀🚀 server listening on port", argv.Port)
}()
}
if argv.Dns {
server := dns.MakeServer(argv, dbConn)
log.Println("🚀🚀 DNS resolver listening on port", argv.DnsPort)
go func() {
err = server.ListenAndServe()
if err != nil {
log.Fatal(err)
}
}()
}
runForever := make(chan struct{})
<-runForever
}

View File

@ -28,8 +28,6 @@
<h2>Add An API Key</h2>
<hr>
<input type="submit" value="Generate" />
</form>
{{ if .FormError }}
{{ if (len .FormError.Errors) }}
{{ range $error := .FormError.Errors }}
@ -37,4 +35,5 @@
{{ end }}
{{ end }}
{{ end }}
</form>
{{ end }}

View File

@ -5,11 +5,12 @@
<th>Name</th>
<th>Content</th>
<th>TTL</th>
<th>Internal</th>
<th>Delete</th>
</tr>
{{ if (eq (len .DNSRecords) 0) }}
<tr>
<td colspan="5"><span class="blinky">No DNS records found</span></td>
<td colspan="6"><span class="blinky">No DNS records found</span></td>
</tr>
{{ end }}
{{ range $record := .DNSRecords }}
@ -17,6 +18,7 @@
<td>{{ $record.Type }}</td>
<td>{{ $record.Name }}</td>
<td>{{ $record.Content }}</td>
<td>{{ $record.Internal }}</td>
<td>{{ $record.TTL }}</td>
<td>
<form method="POST" action="/dns/delete">
@ -64,8 +66,17 @@
value="{{ .RecordForm.TTL }}"
{{ end }}
required />
<label for="internal">
Internal
<input style='display:inline;width:auto;' type="checkbox" name="internal"
{{ if .RecordForm.Internal }}
checked
{{ end }}
/>
</label>
<input type="submit" value="Add" />
</form>
{{ if .FormError }}
{{ if (len .FormError.Errors) }}
@ -74,4 +85,7 @@
{{ end }}
{{ end }}
{{ end }}
</form>
{{ end }}