Herbert Xu | b59f45d | 2006-05-27 23:05:54 -0700 | [diff] [blame] | 1 | /* |
| 2 | * xfrm6_mode_tunnel.c - Tunnel mode encapsulation for IPv6. |
| 3 | * |
| 4 | * Copyright (C) 2002 USAGI/WIDE Project |
| 5 | * Copyright (c) 2004-2006 Herbert Xu <herbert@gondor.apana.org.au> |
| 6 | */ |
| 7 | |
Tejun Heo | 5a0e3ad | 2010-03-24 17:04:11 +0900 | [diff] [blame] | 8 | #include <linux/gfp.h> |
Herbert Xu | b59f45d | 2006-05-27 23:05:54 -0700 | [diff] [blame] | 9 | #include <linux/init.h> |
| 10 | #include <linux/kernel.h> |
| 11 | #include <linux/module.h> |
| 12 | #include <linux/skbuff.h> |
| 13 | #include <linux/stringify.h> |
| 14 | #include <net/dsfield.h> |
| 15 | #include <net/dst.h> |
| 16 | #include <net/inet_ecn.h> |
| 17 | #include <net/ipv6.h> |
| 18 | #include <net/xfrm.h> |
| 19 | |
| 20 | static inline void ipip6_ecn_decapsulate(struct sk_buff *skb) |
| 21 | { |
Arnaldo Carvalho de Melo | 0660e03 | 2007-04-25 17:54:47 -0700 | [diff] [blame] | 22 | struct ipv6hdr *outer_iph = ipv6_hdr(skb); |
Arnaldo Carvalho de Melo | 39b8916 | 2007-04-10 21:06:25 -0700 | [diff] [blame] | 23 | struct ipv6hdr *inner_iph = ipipv6_hdr(skb); |
Herbert Xu | b59f45d | 2006-05-27 23:05:54 -0700 | [diff] [blame] | 24 | |
| 25 | if (INET_ECN_is_ce(ipv6_get_dsfield(outer_iph))) |
| 26 | IP6_ECN_set_ce(inner_iph); |
| 27 | } |
| 28 | |
| 29 | /* Add encapsulation header. |
| 30 | * |
Herbert Xu | ceb1eec8 | 2007-10-10 15:45:52 -0700 | [diff] [blame] | 31 | * The top IP header will be constructed per RFC 2401. |
Herbert Xu | b59f45d | 2006-05-27 23:05:54 -0700 | [diff] [blame] | 32 | */ |
Herbert Xu | 195ad6a | 2007-12-20 13:53:40 -0800 | [diff] [blame] | 33 | static int xfrm6_mode_tunnel_output(struct xfrm_state *x, struct sk_buff *skb) |
Herbert Xu | b59f45d | 2006-05-27 23:05:54 -0700 | [diff] [blame] | 34 | { |
Eric Dumazet | adf3090 | 2009-06-02 05:19:30 +0000 | [diff] [blame] | 35 | struct dst_entry *dst = skb_dst(skb); |
Herbert Xu | 36cf9ac | 2007-11-13 21:40:52 -0800 | [diff] [blame] | 36 | struct ipv6hdr *top_iph; |
Herbert Xu | b59f45d | 2006-05-27 23:05:54 -0700 | [diff] [blame] | 37 | int dsfield; |
| 38 | |
Herbert Xu | 7b277b1 | 2007-10-10 15:44:06 -0700 | [diff] [blame] | 39 | skb_set_network_header(skb, -x->props.header_len); |
Herbert Xu | 37fedd3 | 2007-10-10 15:44:44 -0700 | [diff] [blame] | 40 | skb->mac_header = skb->network_header + |
| 41 | offsetof(struct ipv6hdr, nexthdr); |
Herbert Xu | 36cf9ac | 2007-11-13 21:40:52 -0800 | [diff] [blame] | 42 | skb->transport_header = skb->network_header + sizeof(*top_iph); |
Arnaldo Carvalho de Melo | 0660e03 | 2007-04-25 17:54:47 -0700 | [diff] [blame] | 43 | top_iph = ipv6_hdr(skb); |
Herbert Xu | b59f45d | 2006-05-27 23:05:54 -0700 | [diff] [blame] | 44 | |
| 45 | top_iph->version = 6; |
Herbert Xu | 36cf9ac | 2007-11-13 21:40:52 -0800 | [diff] [blame] | 46 | |
| 47 | memcpy(top_iph->flow_lbl, XFRM_MODE_SKB_CB(skb)->flow_lbl, |
| 48 | sizeof(top_iph->flow_lbl)); |
Eric Dumazet | adf3090 | 2009-06-02 05:19:30 +0000 | [diff] [blame] | 49 | top_iph->nexthdr = xfrm_af2proto(skb_dst(skb)->ops->family); |
Herbert Xu | 36cf9ac | 2007-11-13 21:40:52 -0800 | [diff] [blame] | 50 | |
| 51 | dsfield = XFRM_MODE_SKB_CB(skb)->tos; |
Herbert Xu | b59f45d | 2006-05-27 23:05:54 -0700 | [diff] [blame] | 52 | dsfield = INET_ECN_encapsulate(dsfield, dsfield); |
| 53 | if (x->props.flags & XFRM_STATE_NOECN) |
| 54 | dsfield &= ~INET_ECN_MASK; |
| 55 | ipv6_change_dsfield(top_iph, 0, dsfield); |
Herbert Xu | b59f45d | 2006-05-27 23:05:54 -0700 | [diff] [blame] | 56 | top_iph->hop_limit = dst_metric(dst->child, RTAX_HOPLIMIT); |
| 57 | ipv6_addr_copy(&top_iph->saddr, (struct in6_addr *)&x->props.saddr); |
| 58 | ipv6_addr_copy(&top_iph->daddr, (struct in6_addr *)&x->id.daddr); |
| 59 | return 0; |
| 60 | } |
| 61 | |
Herbert Xu | 195ad6a | 2007-12-20 13:53:40 -0800 | [diff] [blame] | 62 | static int xfrm6_mode_tunnel_input(struct xfrm_state *x, struct sk_buff *skb) |
Herbert Xu | b59f45d | 2006-05-27 23:05:54 -0700 | [diff] [blame] | 63 | { |
| 64 | int err = -EINVAL; |
Arnaldo Carvalho de Melo | 39f69c6 | 2007-03-10 12:40:27 -0300 | [diff] [blame] | 65 | const unsigned char *old_mac; |
Herbert Xu | b59f45d | 2006-05-27 23:05:54 -0700 | [diff] [blame] | 66 | |
Herbert Xu | 227620e | 2007-11-13 21:41:28 -0800 | [diff] [blame] | 67 | if (XFRM_MODE_SKB_CB(skb)->protocol != IPPROTO_IPV6) |
Herbert Xu | b59f45d | 2006-05-27 23:05:54 -0700 | [diff] [blame] | 68 | goto out; |
| 69 | if (!pskb_may_pull(skb, sizeof(struct ipv6hdr))) |
| 70 | goto out; |
| 71 | |
| 72 | if (skb_cloned(skb) && |
| 73 | (err = pskb_expand_head(skb, 0, 0, GFP_ATOMIC))) |
| 74 | goto out; |
| 75 | |
Herbert Xu | 227620e | 2007-11-13 21:41:28 -0800 | [diff] [blame] | 76 | if (x->props.flags & XFRM_STATE_DECAP_DSCP) |
| 77 | ipv6_copy_dscp(ipv6_get_dsfield(ipv6_hdr(skb)), |
| 78 | ipipv6_hdr(skb)); |
| 79 | if (!(x->props.flags & XFRM_STATE_NOECN)) |
| 80 | ipip6_ecn_decapsulate(skb); |
| 81 | |
Arnaldo Carvalho de Melo | 98e399f | 2007-03-19 15:33:04 -0700 | [diff] [blame] | 82 | old_mac = skb_mac_header(skb); |
Arnaldo Carvalho de Melo | 39f69c6 | 2007-03-10 12:40:27 -0300 | [diff] [blame] | 83 | skb_set_mac_header(skb, -skb->mac_len); |
Arnaldo Carvalho de Melo | 98e399f | 2007-03-19 15:33:04 -0700 | [diff] [blame] | 84 | memmove(skb_mac_header(skb), old_mac, skb->mac_len); |
Arnaldo Carvalho de Melo | c1d2bbe | 2007-04-10 20:45:18 -0700 | [diff] [blame] | 85 | skb_reset_network_header(skb); |
Herbert Xu | b59f45d | 2006-05-27 23:05:54 -0700 | [diff] [blame] | 86 | err = 0; |
| 87 | |
| 88 | out: |
| 89 | return err; |
| 90 | } |
| 91 | |
| 92 | static struct xfrm_mode xfrm6_tunnel_mode = { |
Herbert Xu | 195ad6a | 2007-12-20 13:53:40 -0800 | [diff] [blame] | 93 | .input2 = xfrm6_mode_tunnel_input, |
Herbert Xu | 227620e | 2007-11-13 21:41:28 -0800 | [diff] [blame] | 94 | .input = xfrm_prepare_input, |
Herbert Xu | 195ad6a | 2007-12-20 13:53:40 -0800 | [diff] [blame] | 95 | .output2 = xfrm6_mode_tunnel_output, |
Herbert Xu | 36cf9ac | 2007-11-13 21:40:52 -0800 | [diff] [blame] | 96 | .output = xfrm6_prepare_output, |
Herbert Xu | b59f45d | 2006-05-27 23:05:54 -0700 | [diff] [blame] | 97 | .owner = THIS_MODULE, |
| 98 | .encap = XFRM_MODE_TUNNEL, |
Herbert Xu | 1bfcb10 | 2007-10-17 21:31:50 -0700 | [diff] [blame] | 99 | .flags = XFRM_MODE_FLAG_TUNNEL, |
Herbert Xu | b59f45d | 2006-05-27 23:05:54 -0700 | [diff] [blame] | 100 | }; |
| 101 | |
Herbert Xu | 195ad6a | 2007-12-20 13:53:40 -0800 | [diff] [blame] | 102 | static int __init xfrm6_mode_tunnel_init(void) |
Herbert Xu | b59f45d | 2006-05-27 23:05:54 -0700 | [diff] [blame] | 103 | { |
| 104 | return xfrm_register_mode(&xfrm6_tunnel_mode, AF_INET6); |
| 105 | } |
| 106 | |
Herbert Xu | 195ad6a | 2007-12-20 13:53:40 -0800 | [diff] [blame] | 107 | static void __exit xfrm6_mode_tunnel_exit(void) |
Herbert Xu | b59f45d | 2006-05-27 23:05:54 -0700 | [diff] [blame] | 108 | { |
| 109 | int err; |
| 110 | |
| 111 | err = xfrm_unregister_mode(&xfrm6_tunnel_mode, AF_INET6); |
| 112 | BUG_ON(err); |
| 113 | } |
| 114 | |
Herbert Xu | 195ad6a | 2007-12-20 13:53:40 -0800 | [diff] [blame] | 115 | module_init(xfrm6_mode_tunnel_init); |
| 116 | module_exit(xfrm6_mode_tunnel_exit); |
Herbert Xu | b59f45d | 2006-05-27 23:05:54 -0700 | [diff] [blame] | 117 | MODULE_LICENSE("GPL"); |
| 118 | MODULE_ALIAS_XFRM_MODE(AF_INET6, XFRM_MODE_TUNNEL); |