Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * xfrm6_input.c: based on net/ipv4/xfrm4_input.c |
| 3 | * |
| 4 | * Authors: |
| 5 | * Mitsuru KANDA @USAGI |
| 6 | * Kazunori MIYAZAWA @USAGI |
| 7 | * Kunihiro Ishiguro <kunihiro@ipinfusion.com> |
| 8 | * YOSHIFUJI Hideaki @USAGI |
| 9 | * IPv6 support |
| 10 | */ |
| 11 | |
| 12 | #include <linux/module.h> |
| 13 | #include <linux/string.h> |
Patrick McHardy | b05e106 | 2006-01-06 23:03:34 -0800 | [diff] [blame] | 14 | #include <linux/netfilter.h> |
| 15 | #include <linux/netfilter_ipv6.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 16 | #include <net/dsfield.h> |
| 17 | #include <net/inet_ecn.h> |
| 18 | #include <net/ip.h> |
| 19 | #include <net/ipv6.h> |
| 20 | #include <net/xfrm.h> |
| 21 | |
| 22 | static inline void ipip6_ecn_decapsulate(struct sk_buff *skb) |
| 23 | { |
| 24 | struct ipv6hdr *outer_iph = skb->nh.ipv6h; |
| 25 | struct ipv6hdr *inner_iph = skb->h.ipv6h; |
| 26 | |
| 27 | if (INET_ECN_is_ce(ipv6_get_dsfield(outer_iph))) |
| 28 | IP6_ECN_set_ce(inner_iph); |
| 29 | } |
| 30 | |
Herbert Xu | d2acc34 | 2006-03-28 01:12:13 -0800 | [diff] [blame] | 31 | int xfrm6_rcv_spi(struct sk_buff *skb, u32 spi) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 32 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 33 | int err; |
| 34 | u32 seq; |
Herbert Xu | dbe5b4a | 2006-04-01 00:54:16 -0800 | [diff] [blame] | 35 | struct xfrm_state *xfrm_vec[XFRM_MAX_DEPTH]; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 36 | struct xfrm_state *x; |
| 37 | int xfrm_nr = 0; |
| 38 | int decaps = 0; |
| 39 | int nexthdr; |
| 40 | unsigned int nhoff; |
| 41 | |
Patrick McHardy | 951dbc8 | 2006-01-06 23:02:34 -0800 | [diff] [blame] | 42 | nhoff = IP6CB(skb)->nhoff; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 43 | nexthdr = skb->nh.raw[nhoff]; |
| 44 | |
| 45 | seq = 0; |
| 46 | if (!spi && (err = xfrm_parse_spi(skb, nexthdr, &spi, &seq)) != 0) |
| 47 | goto drop; |
| 48 | |
| 49 | do { |
| 50 | struct ipv6hdr *iph = skb->nh.ipv6h; |
| 51 | |
| 52 | if (xfrm_nr == XFRM_MAX_DEPTH) |
| 53 | goto drop; |
| 54 | |
| 55 | x = xfrm_state_lookup((xfrm_address_t *)&iph->daddr, spi, nexthdr, AF_INET6); |
| 56 | if (x == NULL) |
| 57 | goto drop; |
| 58 | spin_lock(&x->lock); |
| 59 | if (unlikely(x->km.state != XFRM_STATE_VALID)) |
| 60 | goto drop_unlock; |
| 61 | |
| 62 | if (x->props.replay_window && xfrm_replay_check(x, seq)) |
| 63 | goto drop_unlock; |
| 64 | |
| 65 | if (xfrm_state_check_expire(x)) |
| 66 | goto drop_unlock; |
| 67 | |
Herbert Xu | e695633 | 2006-04-01 00:52:46 -0800 | [diff] [blame] | 68 | nexthdr = x->type->input(x, skb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 69 | if (nexthdr <= 0) |
| 70 | goto drop_unlock; |
| 71 | |
| 72 | skb->nh.raw[nhoff] = nexthdr; |
| 73 | |
| 74 | if (x->props.replay_window) |
| 75 | xfrm_replay_advance(x, seq); |
| 76 | |
| 77 | x->curlft.bytes += skb->len; |
| 78 | x->curlft.packets++; |
| 79 | |
| 80 | spin_unlock(&x->lock); |
| 81 | |
Herbert Xu | dbe5b4a | 2006-04-01 00:54:16 -0800 | [diff] [blame] | 82 | xfrm_vec[xfrm_nr++] = x; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 83 | |
| 84 | if (x->props.mode) { /* XXX */ |
| 85 | if (nexthdr != IPPROTO_IPV6) |
| 86 | goto drop; |
| 87 | if (!pskb_may_pull(skb, sizeof(struct ipv6hdr))) |
| 88 | goto drop; |
| 89 | if (skb_cloned(skb) && |
| 90 | pskb_expand_head(skb, 0, 0, GFP_ATOMIC)) |
| 91 | goto drop; |
| 92 | if (x->props.flags & XFRM_STATE_DECAP_DSCP) |
| 93 | ipv6_copy_dscp(skb->nh.ipv6h, skb->h.ipv6h); |
| 94 | if (!(x->props.flags & XFRM_STATE_NOECN)) |
| 95 | ipip6_ecn_decapsulate(skb); |
| 96 | skb->mac.raw = memmove(skb->data - skb->mac_len, |
| 97 | skb->mac.raw, skb->mac_len); |
| 98 | skb->nh.raw = skb->data; |
| 99 | decaps = 1; |
| 100 | break; |
| 101 | } |
| 102 | |
| 103 | if ((err = xfrm_parse_spi(skb, nexthdr, &spi, &seq)) < 0) |
| 104 | goto drop; |
| 105 | } while (!err); |
| 106 | |
| 107 | /* Allocate new secpath or COW existing one. */ |
| 108 | if (!skb->sp || atomic_read(&skb->sp->refcnt) != 1) { |
| 109 | struct sec_path *sp; |
| 110 | sp = secpath_dup(skb->sp); |
| 111 | if (!sp) |
| 112 | goto drop; |
| 113 | if (skb->sp) |
| 114 | secpath_put(skb->sp); |
| 115 | skb->sp = sp; |
| 116 | } |
| 117 | |
| 118 | if (xfrm_nr + skb->sp->len > XFRM_MAX_DEPTH) |
| 119 | goto drop; |
| 120 | |
Herbert Xu | dbe5b4a | 2006-04-01 00:54:16 -0800 | [diff] [blame] | 121 | memcpy(skb->sp->xvec + skb->sp->len, xfrm_vec, |
| 122 | xfrm_nr * sizeof(xfrm_vec[0])); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 123 | skb->sp->len += xfrm_nr; |
| 124 | skb->ip_summed = CHECKSUM_NONE; |
| 125 | |
Patrick McHardy | b05e106 | 2006-01-06 23:03:34 -0800 | [diff] [blame] | 126 | nf_reset(skb); |
| 127 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 128 | if (decaps) { |
| 129 | if (!(skb->dev->flags&IFF_LOOPBACK)) { |
| 130 | dst_release(skb->dst); |
| 131 | skb->dst = NULL; |
| 132 | } |
| 133 | netif_rx(skb); |
| 134 | return -1; |
| 135 | } else { |
Patrick McHardy | b05e106 | 2006-01-06 23:03:34 -0800 | [diff] [blame] | 136 | #ifdef CONFIG_NETFILTER |
| 137 | skb->nh.ipv6h->payload_len = htons(skb->len); |
| 138 | __skb_push(skb, skb->data - skb->nh.raw); |
| 139 | |
| 140 | NF_HOOK(PF_INET6, NF_IP6_PRE_ROUTING, skb, skb->dev, NULL, |
| 141 | ip6_rcv_finish); |
| 142 | return -1; |
| 143 | #else |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 144 | return 1; |
Patrick McHardy | b05e106 | 2006-01-06 23:03:34 -0800 | [diff] [blame] | 145 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 146 | } |
| 147 | |
| 148 | drop_unlock: |
| 149 | spin_unlock(&x->lock); |
| 150 | xfrm_state_put(x); |
| 151 | drop: |
| 152 | while (--xfrm_nr >= 0) |
Herbert Xu | dbe5b4a | 2006-04-01 00:54:16 -0800 | [diff] [blame] | 153 | xfrm_state_put(xfrm_vec[xfrm_nr]); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 154 | kfree_skb(skb); |
| 155 | return -1; |
| 156 | } |
| 157 | |
| 158 | EXPORT_SYMBOL(xfrm6_rcv_spi); |
| 159 | |
Patrick McHardy | 951dbc8 | 2006-01-06 23:02:34 -0800 | [diff] [blame] | 160 | int xfrm6_rcv(struct sk_buff **pskb) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 161 | { |
Herbert Xu | d2acc34 | 2006-03-28 01:12:13 -0800 | [diff] [blame] | 162 | return xfrm6_rcv_spi(*pskb, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 163 | } |