135 lines
3.5 KiB
Go
135 lines
3.5 KiB
Go
/*
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* Copyright (C) 2020-2022, IrineSistiana
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*
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* This file is part of mosdns.
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*
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* mosdns is free software: you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation, either version 3 of the License, or
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* (at your option) any later version.
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*
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* mosdns is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see <https://www.gnu.org/licenses/>.
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*/
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package redirect
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import (
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"bytes"
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"context"
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"fmt"
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"os"
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"strings"
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"github.com/IrineSistiana/mosdns/v5/coremain"
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"github.com/IrineSistiana/mosdns/v5/pkg/matcher/domain"
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"github.com/IrineSistiana/mosdns/v5/pkg/query_context"
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"github.com/IrineSistiana/mosdns/v5/plugin/executable/sequence"
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"github.com/miekg/dns"
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"go.uber.org/zap"
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)
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const PluginType = "redirect"
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func init() {
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coremain.RegNewPluginFunc(PluginType, Init, func() any { return new(Args) })
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}
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var _ sequence.RecursiveExecutable = (*Redirect)(nil)
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type Args struct {
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Rules []string `yaml:"rules"`
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Files []string `yaml:"files"`
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}
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type Redirect struct {
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m *domain.MixMatcher[string]
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}
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func Init(bp *coremain.BP, args any) (any, error) {
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r, err := NewRedirect(args.(*Args))
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if err != nil {
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return nil, err
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}
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bp.L().Info("redirect rules loaded", zap.Int("length", r.Len()))
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return r, nil
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}
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func NewRedirect(args *Args) (*Redirect, error) {
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parseFunc := func(s string) (p, v string, err error) {
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f := strings.Fields(s)
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if len(f) != 2 {
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return "", "", fmt.Errorf("redirect rule must have 2 fields, but got %d", len(f))
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}
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return f[0], dns.Fqdn(f[1]), nil
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}
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m := domain.NewMixMatcher[string]()
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m.SetDefaultMatcher(domain.MatcherFull)
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for i, rule := range args.Rules {
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if err := domain.Load[string](m, rule, parseFunc); err != nil {
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return nil, fmt.Errorf("failed to load rule #%d %s, %w", i, rule, err)
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}
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}
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for i, file := range args.Files {
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b, err := os.ReadFile(file)
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if err != nil {
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return nil, fmt.Errorf("failed to read file #%d %s, %w", i, file, err)
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}
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if err := domain.LoadFromTextReader[string](m, bytes.NewReader(b), parseFunc); err != nil {
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return nil, fmt.Errorf("failed to load file #%d %s, %w", i, file, err)
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}
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}
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return &Redirect{m: m}, nil
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}
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func (r *Redirect) Exec(ctx context.Context, qCtx *query_context.Context, next sequence.ChainWalker) error {
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q := qCtx.Q()
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if len(q.Question) != 1 || q.Question[0].Qclass != dns.ClassINET {
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return next.ExecNext(ctx, qCtx)
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}
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orgQName := q.Question[0].Name
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redirectTarget, ok := r.m.Match(orgQName)
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if !ok {
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return next.ExecNext(ctx, qCtx)
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}
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q.Question[0].Name = redirectTarget
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defer func() {
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q.Question[0].Name = orgQName
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}()
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err := next.ExecNext(ctx, qCtx)
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if r := qCtx.R(); r != nil {
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// Restore original query name.
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for i := range r.Question {
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if r.Question[i].Name == redirectTarget {
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r.Question[i].Name = orgQName
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}
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}
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// Insert a CNAME record.
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newAns := make([]dns.RR, 1, len(r.Answer)+1)
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newAns[0] = &dns.CNAME{
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Hdr: dns.RR_Header{
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Name: orgQName,
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Rrtype: dns.TypeCNAME,
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Class: dns.ClassINET,
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Ttl: 1,
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},
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Target: redirectTarget,
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}
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newAns = append(newAns, r.Answer...)
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r.Answer = newAns
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}
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return err
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}
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func (r *Redirect) Len() int {
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return r.m.Len()
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}
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