Autarch Will Control The Internet
This commit is contained in:
DigiJ
349
services/dns-server/server/hosts.go
Normal file
349
services/dns-server/server/hosts.go
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@@ -0,0 +1,349 @@
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package server
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import (
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"bufio"
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"fmt"
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"log"
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"net"
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"os"
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"strings"
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"sync"
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"time"
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"github.com/miekg/dns"
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)
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// HostEntry represents a single hosts file entry.
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type HostEntry struct {
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IP string `json:"ip"`
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Hostname string `json:"hostname"`
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Aliases []string `json:"aliases,omitempty"`
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Comment string `json:"comment,omitempty"`
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}
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// HostsStore manages a hosts-file-like database.
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type HostsStore struct {
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mu sync.RWMutex
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entries []HostEntry
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path string // path to hosts file on disk (if loaded from file)
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}
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// NewHostsStore creates a new hosts store.
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func NewHostsStore() *HostsStore {
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return &HostsStore{
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entries: make([]HostEntry, 0),
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}
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}
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// LoadFile parses a hosts file from disk.
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func (h *HostsStore) LoadFile(path string) error {
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f, err := os.Open(path)
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if err != nil {
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return err
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}
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defer f.Close()
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h.mu.Lock()
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defer h.mu.Unlock()
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h.path = path
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h.entries = h.entries[:0]
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scanner := bufio.NewScanner(f)
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for scanner.Scan() {
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line := strings.TrimSpace(scanner.Text())
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if line == "" || strings.HasPrefix(line, "#") {
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continue
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}
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// Strip inline comments
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comment := ""
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if idx := strings.Index(line, "#"); idx >= 0 {
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comment = strings.TrimSpace(line[idx+1:])
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line = strings.TrimSpace(line[:idx])
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}
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fields := strings.Fields(line)
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if len(fields) < 2 {
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continue
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}
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ip := fields[0]
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if net.ParseIP(ip) == nil {
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continue // invalid IP
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}
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entry := HostEntry{
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IP: ip,
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Hostname: strings.ToLower(fields[1]),
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Comment: comment,
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}
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if len(fields) > 2 {
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aliases := make([]string, len(fields)-2)
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for i, a := range fields[2:] {
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aliases[i] = strings.ToLower(a)
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}
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entry.Aliases = aliases
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}
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h.entries = append(h.entries, entry)
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}
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log.Printf("[hosts] Loaded %d entries from %s", len(h.entries), path)
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return scanner.Err()
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}
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// LoadFromText parses hosts-format text (like pasting /etc/hosts content).
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func (h *HostsStore) LoadFromText(content string) int {
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h.mu.Lock()
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defer h.mu.Unlock()
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count := 0
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scanner := bufio.NewScanner(strings.NewReader(content))
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for scanner.Scan() {
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line := strings.TrimSpace(scanner.Text())
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if line == "" || strings.HasPrefix(line, "#") {
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continue
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}
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comment := ""
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if idx := strings.Index(line, "#"); idx >= 0 {
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comment = strings.TrimSpace(line[idx+1:])
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line = strings.TrimSpace(line[:idx])
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}
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fields := strings.Fields(line)
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if len(fields) < 2 {
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continue
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}
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ip := fields[0]
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if net.ParseIP(ip) == nil {
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continue
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}
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entry := HostEntry{
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IP: ip,
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Hostname: strings.ToLower(fields[1]),
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Comment: comment,
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}
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if len(fields) > 2 {
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aliases := make([]string, len(fields)-2)
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for i, a := range fields[2:] {
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aliases[i] = strings.ToLower(a)
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}
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entry.Aliases = aliases
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}
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// Dedup by hostname
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found := false
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for i, e := range h.entries {
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if e.Hostname == entry.Hostname {
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h.entries[i] = entry
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found = true
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break
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}
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}
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if !found {
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h.entries = append(h.entries, entry)
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}
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count++
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}
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return count
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}
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// Add adds a single host entry.
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func (h *HostsStore) Add(ip, hostname string, aliases []string, comment string) error {
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if net.ParseIP(ip) == nil {
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return fmt.Errorf("invalid IP: %s", ip)
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}
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hostname = strings.ToLower(strings.TrimSpace(hostname))
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if hostname == "" {
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return fmt.Errorf("hostname required")
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}
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h.mu.Lock()
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defer h.mu.Unlock()
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// Check for duplicate
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for i, e := range h.entries {
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if e.Hostname == hostname {
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h.entries[i].IP = ip
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h.entries[i].Aliases = aliases
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h.entries[i].Comment = comment
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return nil
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}
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}
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h.entries = append(h.entries, HostEntry{
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IP: ip,
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Hostname: hostname,
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Aliases: aliases,
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Comment: comment,
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})
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return nil
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}
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// Remove removes a host entry by hostname.
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func (h *HostsStore) Remove(hostname string) bool {
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hostname = strings.ToLower(strings.TrimSpace(hostname))
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h.mu.Lock()
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defer h.mu.Unlock()
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for i, e := range h.entries {
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if e.Hostname == hostname {
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h.entries = append(h.entries[:i], h.entries[i+1:]...)
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return true
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}
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}
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return false
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}
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// Clear removes all entries.
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func (h *HostsStore) Clear() int {
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h.mu.Lock()
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defer h.mu.Unlock()
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n := len(h.entries)
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h.entries = h.entries[:0]
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return n
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}
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// List returns all entries.
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func (h *HostsStore) List() []HostEntry {
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h.mu.RLock()
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defer h.mu.RUnlock()
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result := make([]HostEntry, len(h.entries))
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copy(result, h.entries)
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return result
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}
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// Count returns the number of entries.
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func (h *HostsStore) Count() int {
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h.mu.RLock()
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defer h.mu.RUnlock()
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return len(h.entries)
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}
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// Lookup resolves a hostname from the hosts store.
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// Returns DNS RRs matching the query name and type.
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func (h *HostsStore) Lookup(name string, qtype uint16) []dns.RR {
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if qtype != dns.TypeA && qtype != dns.TypeAAAA && qtype != dns.TypePTR {
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return nil
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}
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h.mu.RLock()
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defer h.mu.RUnlock()
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fqdn := dns.Fqdn(strings.ToLower(name))
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baseName := strings.TrimSuffix(fqdn, ".")
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// PTR lookup (reverse DNS)
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if qtype == dns.TypePTR {
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// Convert in-addr.arpa name to IP
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ip := ptrToIP(fqdn)
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if ip == "" {
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return nil
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}
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for _, e := range h.entries {
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if e.IP == ip {
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rr := &dns.PTR{
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Hdr: dns.RR_Header{
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Name: fqdn,
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Rrtype: dns.TypePTR,
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Class: dns.ClassINET,
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Ttl: 60,
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},
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Ptr: dns.Fqdn(e.Hostname),
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}
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return []dns.RR{rr}
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}
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}
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return nil
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}
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// Forward lookup (A / AAAA)
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var results []dns.RR
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for _, e := range h.entries {
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// Match hostname or aliases
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match := strings.EqualFold(e.Hostname, baseName) || strings.EqualFold(dns.Fqdn(e.Hostname), fqdn)
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if !match {
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for _, a := range e.Aliases {
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if strings.EqualFold(a, baseName) || strings.EqualFold(dns.Fqdn(a), fqdn) {
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match = true
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break
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}
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}
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}
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if !match {
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continue
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}
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ip := net.ParseIP(e.IP)
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if ip == nil {
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continue
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}
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if qtype == dns.TypeA && ip.To4() != nil {
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rr := &dns.A{
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Hdr: dns.RR_Header{
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Name: fqdn,
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Rrtype: dns.TypeA,
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Class: dns.ClassINET,
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Ttl: 60,
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},
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A: ip.To4(),
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}
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results = append(results, rr)
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} else if qtype == dns.TypeAAAA && ip.To4() == nil {
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rr := &dns.AAAA{
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Hdr: dns.RR_Header{
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Name: fqdn,
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Rrtype: dns.TypeAAAA,
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Class: dns.ClassINET,
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Ttl: 60,
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},
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AAAA: ip,
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}
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results = append(results, rr)
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}
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}
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return results
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}
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// Export returns hosts file format text.
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func (h *HostsStore) Export() string {
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h.mu.RLock()
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defer h.mu.RUnlock()
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var sb strings.Builder
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sb.WriteString("# AUTARCH DNS hosts file\n")
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sb.WriteString(fmt.Sprintf("# Generated: %s\n", time.Now().UTC().Format(time.RFC3339)))
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sb.WriteString("# Entries: " + fmt.Sprintf("%d", len(h.entries)) + "\n\n")
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for _, e := range h.entries {
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line := e.IP + "\t" + e.Hostname
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for _, a := range e.Aliases {
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line += "\t" + a
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}
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if e.Comment != "" {
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line += "\t# " + e.Comment
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}
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sb.WriteString(line + "\n")
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}
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return sb.String()
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}
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// ptrToIP converts a PTR domain name (in-addr.arpa) to an IP string.
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func ptrToIP(name string) string {
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name = strings.TrimSuffix(strings.ToLower(name), ".")
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if !strings.HasSuffix(name, ".in-addr.arpa") {
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return ""
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}
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name = strings.TrimSuffix(name, ".in-addr.arpa")
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parts := strings.Split(name, ".")
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if len(parts) != 4 {
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return ""
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}
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// Reverse the octets
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return parts[3] + "." + parts[2] + "." + parts[1] + "." + parts[0]
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}
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