1.4.5.2

EdgeDNS/internal/firewalls/nftables/chain.go

@@ -0,0 +1,369 @@
+// Copyright 2022 Liuxiangchao iwind.liu@gmail.com. All rights reserved.
+//go:build linux
+
+package nftables
+
+import (
+	"bytes"
+	"errors"
+	nft "github.com/google/nftables"
+	"github.com/google/nftables/expr"
+)
+
+const MaxChainNameLength = 31
+
+type RuleOptions struct {
+	Exprs    []expr.Any
+	UserData []byte
+}
+
+// Chain chain object in table
+type Chain struct {
+	conn     *Conn
+	rawTable *nft.Table
+	rawChain *nft.Chain
+}
+
+func NewChain(conn *Conn, rawTable *nft.Table, rawChain *nft.Chain) *Chain {
+	return &Chain{
+		conn:     conn,
+		rawTable: rawTable,
+		rawChain: rawChain,
+	}
+}
+
+func (this *Chain) Raw() *nft.Chain {
+	return this.rawChain
+}
+
+func (this *Chain) Name() string {
+	return this.rawChain.Name
+}
+
+func (this *Chain) AddRule(options *RuleOptions) (*Rule, error) {
+	var rawRule = this.conn.Raw().AddRule(&nft.Rule{
+		Table:    this.rawTable,
+		Chain:    this.rawChain,
+		Exprs:    options.Exprs,
+		UserData: options.UserData,
+	})
+	err := this.conn.Commit()
+	if err != nil {
+		return nil, err
+	}
+	return NewRule(rawRule), nil
+}
+
+func (this *Chain) AddAcceptIPv4Rule(ip []byte, userData []byte) (*Rule, error) {
+	return this.AddRule(&RuleOptions{
+		Exprs: []expr.Any{
+			&expr.Payload{
+				DestRegister: 1,
+				Base:         expr.PayloadBaseNetworkHeader,
+				Offset:       12,
+				Len:          4,
+			},
+			&expr.Cmp{
+				Op:       expr.CmpOpEq,
+				Register: 1,
+				Data:     ip,
+			},
+			&expr.Verdict{
+				Kind: expr.VerdictAccept,
+			},
+		},
+		UserData: userData,
+	})
+}
+
+func (this *Chain) AddAcceptIPv6Rule(ip []byte, userData []byte) (*Rule, error) {
+	return this.AddRule(&RuleOptions{
+		Exprs: []expr.Any{
+			&expr.Payload{
+				DestRegister: 1,
+				Base:         expr.PayloadBaseNetworkHeader,
+				Offset:       8,
+				Len:          16,
+			},
+			&expr.Cmp{
+				Op:       expr.CmpOpEq,
+				Register: 1,
+				Data:     ip,
+			},
+			&expr.Verdict{
+				Kind: expr.VerdictAccept,
+			},
+		},
+		UserData: userData,
+	})
+}
+
+func (this *Chain) AddDropIPv4Rule(ip []byte, userData []byte) (*Rule, error) {
+	return this.AddRule(&RuleOptions{
+		Exprs: []expr.Any{
+			&expr.Payload{
+				DestRegister: 1,
+				Base:         expr.PayloadBaseNetworkHeader,
+				Offset:       12,
+				Len:          4,
+			},
+			&expr.Cmp{
+				Op:       expr.CmpOpEq,
+				Register: 1,
+				Data:     ip,
+			},
+			&expr.Verdict{
+				Kind: expr.VerdictDrop,
+			},
+		},
+		UserData: userData,
+	})
+}
+
+func (this *Chain) AddDropIPv6Rule(ip []byte, userData []byte) (*Rule, error) {
+	return this.AddRule(&RuleOptions{
+		Exprs: []expr.Any{
+			&expr.Payload{
+				DestRegister: 1,
+				Base:         expr.PayloadBaseNetworkHeader,
+				Offset:       8,
+				Len:          16,
+			},
+			&expr.Cmp{
+				Op:       expr.CmpOpEq,
+				Register: 1,
+				Data:     ip,
+			},
+			&expr.Verdict{
+				Kind: expr.VerdictDrop,
+			},
+		},
+		UserData: userData,
+	})
+}
+
+func (this *Chain) AddRejectIPv4Rule(ip []byte, userData []byte) (*Rule, error) {
+	return this.AddRule(&RuleOptions{
+		Exprs: []expr.Any{
+			&expr.Payload{
+				DestRegister: 1,
+				Base:         expr.PayloadBaseNetworkHeader,
+				Offset:       12,
+				Len:          4,
+			},
+			&expr.Cmp{
+				Op:       expr.CmpOpEq,
+				Register: 1,
+				Data:     ip,
+			},
+			&expr.Reject{},
+		},
+		UserData: userData,
+	})
+}
+
+func (this *Chain) AddRejectIPv6Rule(ip []byte, userData []byte) (*Rule, error) {
+	return this.AddRule(&RuleOptions{
+		Exprs: []expr.Any{
+			&expr.Payload{
+				DestRegister: 1,
+				Base:         expr.PayloadBaseNetworkHeader,
+				Offset:       8,
+				Len:          16,
+			},
+			&expr.Cmp{
+				Op:       expr.CmpOpEq,
+				Register: 1,
+				Data:     ip,
+			},
+			&expr.Reject{},
+		},
+		UserData: userData,
+	})
+}
+
+func (this *Chain) AddAcceptIPv4SetRule(setName string, userData []byte) (*Rule, error) {
+	return this.AddRule(&RuleOptions{
+		Exprs: []expr.Any{
+			&expr.Payload{
+				DestRegister: 1,
+				Base:         expr.PayloadBaseNetworkHeader,
+				Offset:       12,
+				Len:          4,
+			},
+			&expr.Lookup{
+				SourceRegister: 1,
+				SetName:        setName,
+			},
+			&expr.Verdict{
+				Kind: expr.VerdictAccept,
+			},
+		},
+		UserData: userData,
+	})
+}
+
+func (this *Chain) AddAcceptIPv6SetRule(setName string, userData []byte) (*Rule, error) {
+	return this.AddRule(&RuleOptions{
+		Exprs: []expr.Any{
+			&expr.Payload{
+				DestRegister: 1,
+				Base:         expr.PayloadBaseNetworkHeader,
+				Offset:       8,
+				Len:          16,
+			},
+			&expr.Lookup{
+				SourceRegister: 1,
+				SetName:        setName,
+			},
+			&expr.Verdict{
+				Kind: expr.VerdictAccept,
+			},
+		},
+		UserData: userData,
+	})
+}
+
+func (this *Chain) AddDropIPv4SetRule(setName string, userData []byte) (*Rule, error) {
+	return this.AddRule(&RuleOptions{
+		Exprs: []expr.Any{
+			&expr.Payload{
+				DestRegister: 1,
+				Base:         expr.PayloadBaseNetworkHeader,
+				Offset:       12,
+				Len:          4,
+			},
+			&expr.Lookup{
+				SourceRegister: 1,
+				SetName:        setName,
+			},
+			&expr.Verdict{
+				Kind: expr.VerdictDrop,
+			},
+		},
+		UserData: userData,
+	})
+}
+
+func (this *Chain) AddDropIPv6SetRule(setName string, userData []byte) (*Rule, error) {
+	return this.AddRule(&RuleOptions{
+		Exprs: []expr.Any{
+			&expr.Payload{
+				DestRegister: 1,
+				Base:         expr.PayloadBaseNetworkHeader,
+				Offset:       8,
+				Len:          16,
+			},
+			&expr.Lookup{
+				SourceRegister: 1,
+				SetName:        setName,
+			},
+			&expr.Verdict{
+				Kind: expr.VerdictDrop,
+			},
+		},
+		UserData: userData,
+	})
+}
+
+func (this *Chain) AddRejectIPv4SetRule(setName string, userData []byte) (*Rule, error) {
+	return this.AddRule(&RuleOptions{
+		Exprs: []expr.Any{
+			&expr.Payload{
+				DestRegister: 1,
+				Base:         expr.PayloadBaseNetworkHeader,
+				Offset:       12,
+				Len:          4,
+			},
+			&expr.Lookup{
+				SourceRegister: 1,
+				SetName:        setName,
+			},
+			&expr.Reject{},
+		},
+		UserData: userData,
+	})
+}
+
+func (this *Chain) AddRejectIPv6SetRule(setName string, userData []byte) (*Rule, error) {
+	return this.AddRule(&RuleOptions{
+		Exprs: []expr.Any{
+			&expr.Payload{
+				DestRegister: 1,
+				Base:         expr.PayloadBaseNetworkHeader,
+				Offset:       8,
+				Len:          16,
+			},
+			&expr.Lookup{
+				SourceRegister: 1,
+				SetName:        setName,
+			},
+			&expr.Reject{},
+		},
+		UserData: userData,
+	})
+}
+
+func (this *Chain) AddAcceptInterfaceRule(interfaceName string, userData []byte) (*Rule, error) {
+	if len(interfaceName) >= 16 {
+		return nil, errors.New("invalid interface name '" + interfaceName + "'")
+	}
+	var ifname = make([]byte, 16)
+	copy(ifname, interfaceName+"\x00")
+
+	return this.AddRule(&RuleOptions{
+		Exprs: []expr.Any{
+			&expr.Meta{
+				Key:      expr.MetaKeyIIFNAME,
+				Register: 1,
+			},
+			&expr.Cmp{
+				Op:       expr.CmpOpEq,
+				Register: 1,
+				Data:     ifname,
+			},
+			&expr.Verdict{
+				Kind: expr.VerdictAccept,
+			},
+		},
+		UserData: userData,
+	})
+}
+
+func (this *Chain) GetRuleWithUserData(userData []byte) (*Rule, error) {
+	rawRules, err := this.conn.Raw().GetRule(this.rawTable, this.rawChain)
+	if err != nil {
+		return nil, err
+	}
+	for _, rawRule := range rawRules {
+		if bytes.Compare(rawRule.UserData, userData) == 0 {
+			return NewRule(rawRule), nil
+		}
+	}
+	return nil, ErrRuleNotFound
+}
+
+func (this *Chain) GetRules() ([]*Rule, error) {
+	rawRules, err := this.conn.Raw().GetRule(this.rawTable, this.rawChain)
+	if err != nil {
+		return nil, err
+	}
+	var result = []*Rule{}
+	for _, rawRule := range rawRules {
+		result = append(result, NewRule(rawRule))
+	}
+	return result, nil
+}
+
+func (this *Chain) DeleteRule(rule *Rule) error {
+	err := this.conn.Raw().DelRule(rule.Raw())
+	if err != nil {
+		return err
+	}
+	return this.conn.Commit()
+}
+
+func (this *Chain) Flush() error {
+	this.conn.Raw().FlushChain(this.rawChain)
+	return this.conn.Commit()
+}