| #include <linux/module.h> |
| #include <linux/errno.h> |
| #include <linux/socket.h> |
| #include <linux/skbuff.h> |
| #include <linux/ip.h> |
| #include <linux/udp.h> |
| #include <linux/icmpv6.h> |
| #include <linux/types.h> |
| #include <linux/kernel.h> |
| #include <net/fou.h> |
| #include <net/ip.h> |
| #include <net/ip6_tunnel.h> |
| #include <net/ip6_checksum.h> |
| #include <net/protocol.h> |
| #include <net/udp.h> |
| #include <net/udp_tunnel.h> |
| |
| #if IS_ENABLED(CONFIG_IPV6_FOU_TUNNEL) |
| |
| static void fou6_build_udp(struct sk_buff *skb, struct ip_tunnel_encap *e, |
| struct flowi6 *fl6, u8 *protocol, __be16 sport) |
| { |
| struct udphdr *uh; |
| |
| skb_push(skb, sizeof(struct udphdr)); |
| skb_reset_transport_header(skb); |
| |
| uh = udp_hdr(skb); |
| |
| uh->dest = e->dport; |
| uh->source = sport; |
| uh->len = htons(skb->len); |
| udp6_set_csum(!(e->flags & TUNNEL_ENCAP_FLAG_CSUM6), skb, |
| &fl6->saddr, &fl6->daddr, skb->len); |
| |
| *protocol = IPPROTO_UDP; |
| } |
| |
| static int fou6_build_header(struct sk_buff *skb, struct ip_tunnel_encap *e, |
| u8 *protocol, struct flowi6 *fl6) |
| { |
| __be16 sport; |
| int err; |
| int type = e->flags & TUNNEL_ENCAP_FLAG_CSUM6 ? |
| SKB_GSO_UDP_TUNNEL_CSUM : SKB_GSO_UDP_TUNNEL; |
| |
| err = __fou_build_header(skb, e, protocol, &sport, type); |
| if (err) |
| return err; |
| |
| fou6_build_udp(skb, e, fl6, protocol, sport); |
| |
| return 0; |
| } |
| |
| static int gue6_build_header(struct sk_buff *skb, struct ip_tunnel_encap *e, |
| u8 *protocol, struct flowi6 *fl6) |
| { |
| __be16 sport; |
| int err; |
| int type = e->flags & TUNNEL_ENCAP_FLAG_CSUM6 ? |
| SKB_GSO_UDP_TUNNEL_CSUM : SKB_GSO_UDP_TUNNEL; |
| |
| err = __gue_build_header(skb, e, protocol, &sport, type); |
| if (err) |
| return err; |
| |
| fou6_build_udp(skb, e, fl6, protocol, sport); |
| |
| return 0; |
| } |
| |
| static int gue6_err_proto_handler(int proto, struct sk_buff *skb, |
| struct inet6_skb_parm *opt, |
| u8 type, u8 code, int offset, __be32 info) |
| { |
| const struct inet6_protocol *ipprot; |
| |
| ipprot = rcu_dereference(inet6_protos[proto]); |
| if (ipprot && ipprot->err_handler) { |
| if (!ipprot->err_handler(skb, opt, type, code, offset, info)) |
| return 0; |
| } |
| |
| return -ENOENT; |
| } |
| |
| static int gue6_err(struct sk_buff *skb, struct inet6_skb_parm *opt, |
| u8 type, u8 code, int offset, __be32 info) |
| { |
| int transport_offset = skb_transport_offset(skb); |
| struct guehdr *guehdr; |
| size_t len, optlen; |
| int ret; |
| |
| len = sizeof(struct udphdr) + sizeof(struct guehdr); |
| if (!pskb_may_pull(skb, transport_offset + len)) |
| return -EINVAL; |
| |
| guehdr = (struct guehdr *)&udp_hdr(skb)[1]; |
| |
| switch (guehdr->version) { |
| case 0: /* Full GUE header present */ |
| break; |
| case 1: { |
| /* Direct encasulation of IPv4 or IPv6 */ |
| skb_set_transport_header(skb, -(int)sizeof(struct icmp6hdr)); |
| |
| switch (((struct iphdr *)guehdr)->version) { |
| case 4: |
| ret = gue6_err_proto_handler(IPPROTO_IPIP, skb, opt, |
| type, code, offset, info); |
| goto out; |
| case 6: |
| ret = gue6_err_proto_handler(IPPROTO_IPV6, skb, opt, |
| type, code, offset, info); |
| goto out; |
| default: |
| ret = -EOPNOTSUPP; |
| goto out; |
| } |
| } |
| default: /* Undefined version */ |
| return -EOPNOTSUPP; |
| } |
| |
| if (guehdr->control) |
| return -ENOENT; |
| |
| optlen = guehdr->hlen << 2; |
| |
| if (!pskb_may_pull(skb, transport_offset + len + optlen)) |
| return -EINVAL; |
| |
| guehdr = (struct guehdr *)&udp_hdr(skb)[1]; |
| if (validate_gue_flags(guehdr, optlen)) |
| return -EINVAL; |
| |
| /* Handling exceptions for direct UDP encapsulation in GUE would lead to |
| * recursion. Besides, this kind of encapsulation can't even be |
| * configured currently. Discard this. |
| */ |
| if (guehdr->proto_ctype == IPPROTO_UDP || |
| guehdr->proto_ctype == IPPROTO_UDPLITE) |
| return -EOPNOTSUPP; |
| |
| skb_set_transport_header(skb, -(int)sizeof(struct icmp6hdr)); |
| ret = gue6_err_proto_handler(guehdr->proto_ctype, skb, |
| opt, type, code, offset, info); |
| |
| out: |
| skb_set_transport_header(skb, transport_offset); |
| return ret; |
| } |
| |
| |
| static const struct ip6_tnl_encap_ops fou_ip6tun_ops = { |
| .encap_hlen = fou_encap_hlen, |
| .build_header = fou6_build_header, |
| .err_handler = gue6_err, |
| }; |
| |
| static const struct ip6_tnl_encap_ops gue_ip6tun_ops = { |
| .encap_hlen = gue_encap_hlen, |
| .build_header = gue6_build_header, |
| .err_handler = gue6_err, |
| }; |
| |
| static int ip6_tnl_encap_add_fou_ops(void) |
| { |
| int ret; |
| |
| ret = ip6_tnl_encap_add_ops(&fou_ip6tun_ops, TUNNEL_ENCAP_FOU); |
| if (ret < 0) { |
| pr_err("can't add fou6 ops\n"); |
| return ret; |
| } |
| |
| ret = ip6_tnl_encap_add_ops(&gue_ip6tun_ops, TUNNEL_ENCAP_GUE); |
| if (ret < 0) { |
| pr_err("can't add gue6 ops\n"); |
| ip6_tnl_encap_del_ops(&fou_ip6tun_ops, TUNNEL_ENCAP_FOU); |
| return ret; |
| } |
| |
| return 0; |
| } |
| |
| static void ip6_tnl_encap_del_fou_ops(void) |
| { |
| ip6_tnl_encap_del_ops(&fou_ip6tun_ops, TUNNEL_ENCAP_FOU); |
| ip6_tnl_encap_del_ops(&gue_ip6tun_ops, TUNNEL_ENCAP_GUE); |
| } |
| |
| #else |
| |
| static int ip6_tnl_encap_add_fou_ops(void) |
| { |
| return 0; |
| } |
| |
| static void ip6_tnl_encap_del_fou_ops(void) |
| { |
| } |
| |
| #endif |
| |
| static int __init fou6_init(void) |
| { |
| int ret; |
| |
| ret = ip6_tnl_encap_add_fou_ops(); |
| |
| return ret; |
| } |
| |
| static void __exit fou6_fini(void) |
| { |
| ip6_tnl_encap_del_fou_ops(); |
| } |
| |
| module_init(fou6_init); |
| module_exit(fou6_fini); |
| MODULE_AUTHOR("Tom Herbert <therbert@google.com>"); |
| MODULE_LICENSE("GPL"); |