Diego Beltrami | 0a69452 | 2006-10-03 23:47:05 -0700 | [diff] [blame] | 1 | /* |
| 2 | * xfrm6_mode_beet.c - BEET mode encapsulation for IPv6. |
| 3 | * |
| 4 | * Copyright (c) 2006 Diego Beltrami <diego.beltrami@gmail.com> |
| 5 | * Miika Komu <miika@iki.fi> |
| 6 | * Herbert Xu <herbert@gondor.apana.org.au> |
| 7 | * Abhinav Pathak <abhinav.pathak@hiit.fi> |
| 8 | * Jeff Ahrenholz <ahrenholz@gmail.com> |
| 9 | */ |
| 10 | |
| 11 | #include <linux/init.h> |
| 12 | #include <linux/kernel.h> |
| 13 | #include <linux/module.h> |
| 14 | #include <linux/skbuff.h> |
| 15 | #include <linux/stringify.h> |
| 16 | #include <net/dsfield.h> |
| 17 | #include <net/dst.h> |
| 18 | #include <net/inet_ecn.h> |
| 19 | #include <net/ipv6.h> |
| 20 | #include <net/xfrm.h> |
| 21 | |
| 22 | /* Add encapsulation header. |
| 23 | * |
| 24 | * The top IP header will be constructed per draft-nikander-esp-beet-mode-06.txt. |
| 25 | * The following fields in it shall be filled in by x->type->output: |
| 26 | * payload_len |
| 27 | * |
| 28 | * On exit, skb->h will be set to the start of the encapsulation header to be |
Herbert Xu | 007f021 | 2007-10-09 13:25:59 -0700 | [diff] [blame] | 29 | * filled in by x->type->output and the mac header will be set to the |
| 30 | * nextheader field of the extension header directly preceding the |
| 31 | * encapsulation header, or in its absence, that of the top IP header. |
| 32 | * The value of skb->data and the network header will always point to the |
| 33 | * top IP header. |
Diego Beltrami | 0a69452 | 2006-10-03 23:47:05 -0700 | [diff] [blame] | 34 | */ |
| 35 | static int xfrm6_beet_output(struct xfrm_state *x, struct sk_buff *skb) |
| 36 | { |
| 37 | struct ipv6hdr *iph, *top_iph; |
| 38 | u8 *prevhdr; |
| 39 | int hdr_len; |
| 40 | |
| 41 | skb_push(skb, x->props.header_len); |
Arnaldo Carvalho de Melo | 0660e03 | 2007-04-25 17:54:47 -0700 | [diff] [blame] | 42 | iph = ipv6_hdr(skb); |
Diego Beltrami | 0a69452 | 2006-10-03 23:47:05 -0700 | [diff] [blame] | 43 | |
| 44 | hdr_len = ip6_find_1stfragopt(skb, &prevhdr); |
Diego Beltrami | 0a69452 | 2006-10-03 23:47:05 -0700 | [diff] [blame] | 45 | memmove(skb->data, iph, hdr_len); |
| 46 | |
Herbert Xu | bee0b40 | 2007-10-10 15:42:23 -0700 | [diff] [blame^] | 47 | skb_set_mac_header(skb, (prevhdr - x->props.header_len) - skb->data); |
Arnaldo Carvalho de Melo | c1d2bbe | 2007-04-10 20:45:18 -0700 | [diff] [blame] | 48 | skb_reset_network_header(skb); |
Herbert Xu | bee0b40 | 2007-10-10 15:42:23 -0700 | [diff] [blame^] | 49 | skb_set_transport_header(skb, hdr_len); |
Arnaldo Carvalho de Melo | 0660e03 | 2007-04-25 17:54:47 -0700 | [diff] [blame] | 50 | top_iph = ipv6_hdr(skb); |
Diego Beltrami | 0a69452 | 2006-10-03 23:47:05 -0700 | [diff] [blame] | 51 | |
| 52 | ipv6_addr_copy(&top_iph->saddr, (struct in6_addr *)&x->props.saddr); |
| 53 | ipv6_addr_copy(&top_iph->daddr, (struct in6_addr *)&x->id.daddr); |
| 54 | |
| 55 | return 0; |
| 56 | } |
| 57 | |
| 58 | static int xfrm6_beet_input(struct xfrm_state *x, struct sk_buff *skb) |
| 59 | { |
| 60 | struct ipv6hdr *ip6h; |
Arnaldo Carvalho de Melo | 39f69c6 | 2007-03-10 12:40:27 -0300 | [diff] [blame] | 61 | const unsigned char *old_mac; |
Diego Beltrami | 0a69452 | 2006-10-03 23:47:05 -0700 | [diff] [blame] | 62 | int size = sizeof(struct ipv6hdr); |
| 63 | int err = -EINVAL; |
| 64 | |
| 65 | if (!pskb_may_pull(skb, sizeof(struct ipv6hdr))) |
| 66 | goto out; |
| 67 | |
| 68 | skb_push(skb, size); |
Arnaldo Carvalho de Melo | d56f90a | 2007-04-10 20:50:43 -0700 | [diff] [blame] | 69 | memmove(skb->data, skb_network_header(skb), size); |
Arnaldo Carvalho de Melo | c1d2bbe | 2007-04-10 20:45:18 -0700 | [diff] [blame] | 70 | skb_reset_network_header(skb); |
Diego Beltrami | 0a69452 | 2006-10-03 23:47:05 -0700 | [diff] [blame] | 71 | |
Arnaldo Carvalho de Melo | 98e399f | 2007-03-19 15:33:04 -0700 | [diff] [blame] | 72 | old_mac = skb_mac_header(skb); |
Arnaldo Carvalho de Melo | 39f69c6 | 2007-03-10 12:40:27 -0300 | [diff] [blame] | 73 | skb_set_mac_header(skb, -skb->mac_len); |
Arnaldo Carvalho de Melo | 98e399f | 2007-03-19 15:33:04 -0700 | [diff] [blame] | 74 | memmove(skb_mac_header(skb), old_mac, skb->mac_len); |
Diego Beltrami | 0a69452 | 2006-10-03 23:47:05 -0700 | [diff] [blame] | 75 | |
Arnaldo Carvalho de Melo | 0660e03 | 2007-04-25 17:54:47 -0700 | [diff] [blame] | 76 | ip6h = ipv6_hdr(skb); |
Diego Beltrami | 0a69452 | 2006-10-03 23:47:05 -0700 | [diff] [blame] | 77 | ip6h->payload_len = htons(skb->len - size); |
| 78 | ipv6_addr_copy(&ip6h->daddr, (struct in6_addr *) &x->sel.daddr.a6); |
| 79 | ipv6_addr_copy(&ip6h->saddr, (struct in6_addr *) &x->sel.saddr.a6); |
| 80 | err = 0; |
| 81 | out: |
| 82 | return err; |
| 83 | } |
| 84 | |
| 85 | static struct xfrm_mode xfrm6_beet_mode = { |
| 86 | .input = xfrm6_beet_input, |
| 87 | .output = xfrm6_beet_output, |
| 88 | .owner = THIS_MODULE, |
| 89 | .encap = XFRM_MODE_BEET, |
| 90 | }; |
| 91 | |
| 92 | static int __init xfrm6_beet_init(void) |
| 93 | { |
| 94 | return xfrm_register_mode(&xfrm6_beet_mode, AF_INET6); |
| 95 | } |
| 96 | |
| 97 | static void __exit xfrm6_beet_exit(void) |
| 98 | { |
| 99 | int err; |
| 100 | |
| 101 | err = xfrm_unregister_mode(&xfrm6_beet_mode, AF_INET6); |
| 102 | BUG_ON(err); |
| 103 | } |
| 104 | |
| 105 | module_init(xfrm6_beet_init); |
| 106 | module_exit(xfrm6_beet_exit); |
| 107 | MODULE_LICENSE("GPL"); |
| 108 | MODULE_ALIAS_XFRM_MODE(AF_INET6, XFRM_MODE_BEET); |