Files
netbird/client/firewall/nftables/addr_family_linux.go

82 lines
2.3 KiB
Go

package nftables
import (
"fmt"
"net"
"github.com/google/nftables"
"golang.org/x/sys/unix"
firewall "github.com/netbirdio/netbird/client/firewall/manager"
)
var (
// afIPv4 defines IPv4 header layout and nftables types.
afIPv4 = addrFamily{
protoOffset: 9,
srcAddrOffset: 12,
dstAddrOffset: 16,
addrLen: net.IPv4len,
totalBits: 8 * net.IPv4len,
setKeyType: nftables.TypeIPAddr,
tableFamily: nftables.TableFamilyIPv4,
icmpProto: unix.IPPROTO_ICMP,
}
// afIPv6 defines IPv6 header layout and nftables types.
afIPv6 = addrFamily{
protoOffset: 6,
srcAddrOffset: 8,
dstAddrOffset: 24,
addrLen: net.IPv6len,
totalBits: 8 * net.IPv6len,
setKeyType: nftables.TypeIP6Addr,
tableFamily: nftables.TableFamilyIPv6,
icmpProto: unix.IPPROTO_ICMPV6,
}
)
// addrFamily holds protocol-specific constants for nftables expression building.
type addrFamily struct {
// protoOffset is the IP header offset for the protocol/next-header field (9 for v4, 6 for v6)
protoOffset uint32
// srcAddrOffset is the IP header offset for the source address (12 for v4, 8 for v6)
srcAddrOffset uint32
// dstAddrOffset is the IP header offset for the destination address (16 for v4, 24 for v6)
dstAddrOffset uint32
// addrLen is the byte length of addresses (4 for v4, 16 for v6)
addrLen uint32
// totalBits is the address size in bits (32 for v4, 128 for v6)
totalBits int
// setKeyType is the nftables set data type for addresses
setKeyType nftables.SetDatatype
// tableFamily is the nftables table family
tableFamily nftables.TableFamily
// icmpProto is the ICMP protocol number for this family (1 for v4, 58 for v6)
icmpProto uint8
}
// familyForAddr returns the address family for the given IP.
func familyForAddr(is4 bool) addrFamily {
if is4 {
return afIPv4
}
return afIPv6
}
// protoNum converts a firewall protocol to the IP protocol number,
// using the correct ICMP variant for the address family.
func (af addrFamily) protoNum(protocol firewall.Protocol) (uint8, error) {
switch protocol {
case firewall.ProtocolTCP:
return unix.IPPROTO_TCP, nil
case firewall.ProtocolUDP:
return unix.IPPROTO_UDP, nil
case firewall.ProtocolICMP:
return af.icmpProto, nil
case firewall.ProtocolALL:
return 0, nil
default:
return 0, fmt.Errorf("unsupported protocol: %s", protocol)
}
}