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> |
| 14 | #include <net/dsfield.h> |
| 15 | #include <net/inet_ecn.h> |
| 16 | #include <net/ip.h> |
| 17 | #include <net/ipv6.h> |
| 18 | #include <net/xfrm.h> |
| 19 | |
| 20 | static inline void ipip6_ecn_decapsulate(struct sk_buff *skb) |
| 21 | { |
| 22 | struct ipv6hdr *outer_iph = skb->nh.ipv6h; |
| 23 | struct ipv6hdr *inner_iph = skb->h.ipv6h; |
| 24 | |
| 25 | if (INET_ECN_is_ce(ipv6_get_dsfield(outer_iph))) |
| 26 | IP6_ECN_set_ce(inner_iph); |
| 27 | } |
| 28 | |
| 29 | int xfrm6_rcv_spi(struct sk_buff **pskb, unsigned int *nhoffp, u32 spi) |
| 30 | { |
| 31 | struct sk_buff *skb = *pskb; |
| 32 | int err; |
| 33 | u32 seq; |
| 34 | struct sec_decap_state xfrm_vec[XFRM_MAX_DEPTH]; |
| 35 | struct xfrm_state *x; |
| 36 | int xfrm_nr = 0; |
| 37 | int decaps = 0; |
| 38 | int nexthdr; |
| 39 | unsigned int nhoff; |
| 40 | |
| 41 | nhoff = *nhoffp; |
| 42 | nexthdr = skb->nh.raw[nhoff]; |
| 43 | |
| 44 | seq = 0; |
| 45 | if (!spi && (err = xfrm_parse_spi(skb, nexthdr, &spi, &seq)) != 0) |
| 46 | goto drop; |
| 47 | |
| 48 | do { |
| 49 | struct ipv6hdr *iph = skb->nh.ipv6h; |
| 50 | |
| 51 | if (xfrm_nr == XFRM_MAX_DEPTH) |
| 52 | goto drop; |
| 53 | |
| 54 | x = xfrm_state_lookup((xfrm_address_t *)&iph->daddr, spi, nexthdr, AF_INET6); |
| 55 | if (x == NULL) |
| 56 | goto drop; |
| 57 | spin_lock(&x->lock); |
| 58 | if (unlikely(x->km.state != XFRM_STATE_VALID)) |
| 59 | goto drop_unlock; |
| 60 | |
| 61 | if (x->props.replay_window && xfrm_replay_check(x, seq)) |
| 62 | goto drop_unlock; |
| 63 | |
| 64 | if (xfrm_state_check_expire(x)) |
| 65 | goto drop_unlock; |
| 66 | |
| 67 | nexthdr = x->type->input(x, &(xfrm_vec[xfrm_nr].decap), skb); |
| 68 | if (nexthdr <= 0) |
| 69 | goto drop_unlock; |
| 70 | |
| 71 | skb->nh.raw[nhoff] = nexthdr; |
| 72 | |
| 73 | if (x->props.replay_window) |
| 74 | xfrm_replay_advance(x, seq); |
| 75 | |
| 76 | x->curlft.bytes += skb->len; |
| 77 | x->curlft.packets++; |
| 78 | |
| 79 | spin_unlock(&x->lock); |
| 80 | |
| 81 | xfrm_vec[xfrm_nr++].xvec = x; |
| 82 | |
| 83 | if (x->props.mode) { /* XXX */ |
| 84 | if (nexthdr != IPPROTO_IPV6) |
| 85 | goto drop; |
| 86 | if (!pskb_may_pull(skb, sizeof(struct ipv6hdr))) |
| 87 | goto drop; |
| 88 | if (skb_cloned(skb) && |
| 89 | pskb_expand_head(skb, 0, 0, GFP_ATOMIC)) |
| 90 | goto drop; |
| 91 | if (x->props.flags & XFRM_STATE_DECAP_DSCP) |
| 92 | ipv6_copy_dscp(skb->nh.ipv6h, skb->h.ipv6h); |
| 93 | if (!(x->props.flags & XFRM_STATE_NOECN)) |
| 94 | ipip6_ecn_decapsulate(skb); |
| 95 | skb->mac.raw = memmove(skb->data - skb->mac_len, |
| 96 | skb->mac.raw, skb->mac_len); |
| 97 | skb->nh.raw = skb->data; |
| 98 | decaps = 1; |
| 99 | break; |
| 100 | } |
| 101 | |
| 102 | if ((err = xfrm_parse_spi(skb, nexthdr, &spi, &seq)) < 0) |
| 103 | goto drop; |
| 104 | } while (!err); |
| 105 | |
| 106 | /* Allocate new secpath or COW existing one. */ |
| 107 | if (!skb->sp || atomic_read(&skb->sp->refcnt) != 1) { |
| 108 | struct sec_path *sp; |
| 109 | sp = secpath_dup(skb->sp); |
| 110 | if (!sp) |
| 111 | goto drop; |
| 112 | if (skb->sp) |
| 113 | secpath_put(skb->sp); |
| 114 | skb->sp = sp; |
| 115 | } |
| 116 | |
| 117 | if (xfrm_nr + skb->sp->len > XFRM_MAX_DEPTH) |
| 118 | goto drop; |
| 119 | |
| 120 | memcpy(skb->sp->x+skb->sp->len, xfrm_vec, xfrm_nr*sizeof(struct sec_decap_state)); |
| 121 | skb->sp->len += xfrm_nr; |
| 122 | skb->ip_summed = CHECKSUM_NONE; |
| 123 | |
| 124 | if (decaps) { |
| 125 | if (!(skb->dev->flags&IFF_LOOPBACK)) { |
| 126 | dst_release(skb->dst); |
| 127 | skb->dst = NULL; |
| 128 | } |
| 129 | netif_rx(skb); |
| 130 | return -1; |
| 131 | } else { |
| 132 | return 1; |
| 133 | } |
| 134 | |
| 135 | drop_unlock: |
| 136 | spin_unlock(&x->lock); |
| 137 | xfrm_state_put(x); |
| 138 | drop: |
| 139 | while (--xfrm_nr >= 0) |
| 140 | xfrm_state_put(xfrm_vec[xfrm_nr].xvec); |
| 141 | kfree_skb(skb); |
| 142 | return -1; |
| 143 | } |
| 144 | |
| 145 | EXPORT_SYMBOL(xfrm6_rcv_spi); |
| 146 | |
| 147 | int xfrm6_rcv(struct sk_buff **pskb, unsigned int *nhoffp) |
| 148 | { |
| 149 | return xfrm6_rcv_spi(pskb, nhoffp, 0); |
| 150 | } |