Skip to content

Commit

Permalink
chore: Improve data validation (#94)
Browse files Browse the repository at this point in the history 
* add more validation to data

* yes yes... much comment such wow

* improve structure

* improve structure part 2
  • Loading branch information
@mircea-pavel-anton
mircea-pavel-anton authored Oct 26, 2024
1 parent dc482cc commit b678494
Show file tree
Hide file tree
Showing 2 changed files with 565 additions and 285 deletions.
163 changes: 131 additions & 32 deletions internal/mikrotik/record.go
View file
Original file line number Diff line number Diff line change
Expand Up @@ -47,60 +47,63 @@ type DNSRecord struct {
func NewDNSRecord(endpoint *endpoint.Endpoint) (*DNSRecord, error) {
log.Debugf("Converting ExternalDNS endpoint to MikrotikDNS: %v", endpoint)

// Sanity checks -> Fields are not empty and if set, they are set correctly
if endpoint.DNSName == "" {
return nil, fmt.Errorf("DNS name is required")
}

if endpoint.RecordType == "" {
return nil, fmt.Errorf("record type is required")
}

if len(endpoint.Targets) == 0 || endpoint.Targets[0] == "" {
return nil, fmt.Errorf("no target provided for DNS record")
}

record := &DNSRecord{Name: endpoint.DNSName}
log.Debugf("Name set to: %s", record.Name)
// Convert ExternalDNS TTL to Mikrotik TTL
ttl, err := endpointTTLtoMikrotikTTL(endpoint.RecordTTL)
if err != nil {
return nil, fmt.Errorf("failed to convert TTL: %v", err)
}

record.Type = endpoint.RecordType
// Initialize new records
record := &DNSRecord{Name: endpoint.DNSName, Type: endpoint.RecordType, TTL: ttl}
log.Debugf("Name set to: %s", record.Name)
log.Debugf("Type set to: %s", record.Type)
log.Debugf("TTL set to: %s", record.TTL)

// Record-type specific data
switch record.Type {
case "A":
record.Address = endpoint.Targets[0]
if net.ParseIP(record.Address) == nil || strings.Contains(record.Address, ":") {
return nil, fmt.Errorf("invalid IPv4 address: %s", record.Address)
if err := validateIPv4(endpoint.Targets[0]); err != nil {
return nil, err
}
record.Address = endpoint.Targets[0]
log.Debugf("Address set to: %s", record.Address)

case "AAAA":
record.Address = endpoint.Targets[0]
if net.ParseIP(record.Address) == nil || !strings.Contains(record.Address, ":") {
return nil, fmt.Errorf("invalid IPv6 address: %s", record.Address)
if err := validateIPv6(endpoint.Targets[0]); err != nil {
return nil, err
}
record.Address = endpoint.Targets[0]
log.Debugf("Address set to: %s", record.Address)

case "CNAME":
record.CName = endpoint.Targets[0]
if record.CName == "" {
return nil, fmt.Errorf("CNAME target cannot be empty")
if err := validateDomain(endpoint.Targets[0]); err != nil {
return nil, err
}
log.Debugf("CName set to: %s", record.CName)
record.CName = endpoint.Targets[0]
log.Debugf("CNAME set to: %s", record.Address)

case "TXT":
record.Text = endpoint.Targets[0]
if record.Text == "" {
return nil, fmt.Errorf("TXT record text cannot be empty")
if err := validateTXT(endpoint.Targets[0]); err != nil {
return nil, err
}
record.Text = endpoint.Targets[0]
log.Debugf("Text set to: %s", record.Text)

default:
return nil, fmt.Errorf("unsupported DNS type: %s", endpoint.RecordType)
}

ttl, err := endpointTTLtoMikrotikTTL(endpoint.RecordTTL)
if err != nil {
return nil, fmt.Errorf("failed to convert TTL: %v", err)
}
record.TTL = ttl
log.Debugf("TTL set to: %s", record.TTL)

for _, providerSpecific := range endpoint.ProviderSpecific {
switch providerSpecific.Name {
case "comment":
Expand Down Expand Up @@ -132,36 +135,75 @@ func NewDNSRecord(endpoint *endpoint.Endpoint) (*DNSRecord, error) {
func (r *DNSRecord) toExternalDNSEndpoint() (*endpoint.Endpoint, error) {
log.Debugf("Converting MikrotikDNS record to ExternalDNS: %v", r)

// ============================================================================================
// Sanity checks
// ============================================================================================
if r.Name == "" {
return nil, fmt.Errorf("DNS record name cannot be empty")
}

//? Mikrotik assumes A-records are default and sometimes omits setting the type
if r.Type == "" {
log.Debugf("Record type not set. Using default value 'A'")
r.Type = "A"
}

ttl, err := mikrotikTTLtoEndpointTTL(r.TTL)
if err != nil {
return nil, fmt.Errorf("failed to convert MikrotikDNS record to ExternalDNS: %v", err)
}

// Initialize endpoint
ep := endpoint.Endpoint{
DNSName: r.Name,
RecordType: r.Type,
RecordTTL: ttl,
}

// ============================================================================================
// Record-specific data
// ============================================================================================
switch ep.RecordType {
case "A", "AAAA":
case "A":
if err := validateIPv4(r.Address); err != nil {
return nil, err
}
ep.Targets = endpoint.NewTargets(r.Address)
log.Debugf("Address set to: %s", r.Address)

case "AAAA":
if err := validateIPv6(r.Address); err != nil {
return nil, err
}
ep.Targets = endpoint.NewTargets(r.Address)
log.Debugf("Address set to: %s", r.Address)

case "CNAME":
if err := validateDomain(r.CName); err != nil {
return nil, err
}
ep.Targets = endpoint.NewTargets(r.CName)
log.Debugf("CNAME set to: %s", r.CName)

case "TXT":
if err := validateTXT(r.Text); err != nil {
return nil, err
}
ep.Targets = endpoint.NewTargets(r.Text)
log.Debugf("Text set to: %s", r.Text)

default:
return nil, fmt.Errorf("unsupported DNS type: %s", ep.RecordType)
}

// Ensure at least one target is present and non-empty
if len(ep.Targets) == 0 || ep.Targets[0] == "" {
return nil, fmt.Errorf("no target provided for DNS record")
}

ttl, err := mikrotikTTLtoEndpointTTL(r.TTL)
if err != nil {
return nil, fmt.Errorf("failed to convert MikrotikDNS record to ExternalDNS: %v", err)
}
ep.RecordTTL = ttl

// ============================================================================================
// Provider-specific stuff
// ============================================================================================
if r.Comment != "" {
ep.ProviderSpecific = append(ep.ProviderSpecific, endpoint.ProviderSpecificProperty{
Name: "comment",
Expand Down Expand Up @@ -191,6 +233,9 @@ func (r *DNSRecord) toExternalDNSEndpoint() (*endpoint.Endpoint, error) {
return &ep, nil
}

// ================================================================================================
// UTILS
// ================================================================================================
// mikrotikTTLtoEndpointTTL converts a Mikrotik TTL to an ExternalDNS TTL
func mikrotikTTLtoEndpointTTL(ttl string) (endpoint.TTL, error) {
log.Debugf("Converting Mikrotik TTL to Endpoint TTL: %s", ttl)
Expand Down Expand Up @@ -296,3 +341,57 @@ func endpointTTLtoMikrotikTTL(ttl endpoint.TTL) (string, error) {
log.Debugf("Converted TTL: %v", durationStr)
return durationStr, nil
}

// validateIPv4 checks if the provided address is a valid IPv4 address.
func validateIPv4(address string) error {
if net.ParseIP(address) == nil {
return fmt.Errorf("invalid IP address: %s", address)
}

if strings.Contains(address, ":") {
return fmt.Errorf("provided address looks like an IPv6 address: %s", address)
}

return nil
}

// validateIPv6 checks if the provided address is a valid IPv6 address.
func validateIPv6(address string) error {
if net.ParseIP(address) == nil {
return fmt.Errorf("invalid IP address: %s", address)
}

if !strings.Contains(address, ":") {
return fmt.Errorf("provided address looks like an IPv4 address: %s", address)
}

return nil
}

// validateTXT checks if the provided TXT record text is valid.
func validateTXT(text string) error {
if text == "" {
return fmt.Errorf("TXT record text cannot be empty")
}
//? TODO: add more validation here?
return nil
}

// validateDomain checks if the provided domain is semantically valid.
func validateDomain(domain string) error {
if domain == "" {
return fmt.Errorf("a domain cannot be empty")
}

if len(domain) > 253 {
return fmt.Errorf("invalid domain, length exceeds 253 characters")
}

domainRegex := `^(?i:[a-z0-9]([-a-z0-9]{0,61}[a-z0-9])?\.)+[a-z]{2,}$`
matched, err := regexp.MatchString(domainRegex, domain)
if err != nil || !matched {
return fmt.Errorf("invalid domain: %s", domain)
}

return nil
}
Loading

0 comments on commit b678494

Please sign in to comment.