diff options
Diffstat (limited to 'net/ipv4/xfrm4_input.c')
| -rw-r--r-- | net/ipv4/xfrm4_input.c | 160 |
1 files changed, 160 insertions, 0 deletions
diff --git a/net/ipv4/xfrm4_input.c b/net/ipv4/xfrm4_input.c new file mode 100644 index 00000000000..2d3849c38a0 --- /dev/null +++ b/net/ipv4/xfrm4_input.c @@ -0,0 +1,160 @@ +/* + * xfrm4_input.c + * + * Changes: + * YOSHIFUJI Hideaki @USAGI + * Split up af-specific portion + * Derek Atkins <derek@ihtfp.com> + * Add Encapsulation support + * + */ + +#include <linux/module.h> +#include <linux/string.h> +#include <net/inet_ecn.h> +#include <net/ip.h> +#include <net/xfrm.h> + +int xfrm4_rcv(struct sk_buff *skb) +{ + return xfrm4_rcv_encap(skb, 0); +} + +EXPORT_SYMBOL(xfrm4_rcv); + +static inline void ipip_ecn_decapsulate(struct sk_buff *skb) +{ + struct iphdr *outer_iph = skb->nh.iph; + struct iphdr *inner_iph = skb->h.ipiph; + + if (INET_ECN_is_ce(outer_iph->tos)) + IP_ECN_set_ce(inner_iph); +} + +static int xfrm4_parse_spi(struct sk_buff *skb, u8 nexthdr, u32 *spi, u32 *seq) +{ + switch (nexthdr) { + case IPPROTO_IPIP: + if (!pskb_may_pull(skb, sizeof(struct iphdr))) + return -EINVAL; + *spi = skb->nh.iph->saddr; + *seq = 0; + return 0; + } + + return xfrm_parse_spi(skb, nexthdr, spi, seq); +} + +int xfrm4_rcv_encap(struct sk_buff *skb, __u16 encap_type) +{ + int err; + u32 spi, seq; + struct sec_decap_state xfrm_vec[XFRM_MAX_DEPTH]; + struct xfrm_state *x; + int xfrm_nr = 0; + int decaps = 0; + + if ((err = xfrm4_parse_spi(skb, skb->nh.iph->protocol, &spi, &seq)) != 0) + goto drop; + + do { + struct iphdr *iph = skb->nh.iph; + + if (xfrm_nr == XFRM_MAX_DEPTH) + goto drop; + + x = xfrm_state_lookup((xfrm_address_t *)&iph->daddr, spi, iph->protocol, AF_INET); + if (x == NULL) + goto drop; + + spin_lock(&x->lock); + if (unlikely(x->km.state != XFRM_STATE_VALID)) + goto drop_unlock; + + if (x->props.replay_window && xfrm_replay_check(x, seq)) + goto drop_unlock; + + if (xfrm_state_check_expire(x)) + goto drop_unlock; + + xfrm_vec[xfrm_nr].decap.decap_type = encap_type; + if (x->type->input(x, &(xfrm_vec[xfrm_nr].decap), skb)) + goto drop_unlock; + + /* only the first xfrm gets the encap type */ + encap_type = 0; + + if (x->props.replay_window) + xfrm_replay_advance(x, seq); + + x->curlft.bytes += skb->len; + x->curlft.packets++; + + spin_unlock(&x->lock); + + xfrm_vec[xfrm_nr++].xvec = x; + + iph = skb->nh.iph; + + if (x->props.mode) { + if (iph->protocol != IPPROTO_IPIP) + goto drop; + if (!pskb_may_pull(skb, sizeof(struct iphdr))) + goto drop; + if (skb_cloned(skb) && + pskb_expand_head(skb, 0, 0, GFP_ATOMIC)) + goto drop; + if (x->props.flags & XFRM_STATE_DECAP_DSCP) + ipv4_copy_dscp(iph, skb->h.ipiph); + if (!(x->props.flags & XFRM_STATE_NOECN)) + ipip_ecn_decapsulate(skb); + skb->mac.raw = memmove(skb->data - skb->mac_len, + skb->mac.raw, skb->mac_len); + skb->nh.raw = skb->data; + memset(&(IPCB(skb)->opt), 0, sizeof(struct ip_options)); + decaps = 1; + break; + } + + if ((err = xfrm_parse_spi(skb, skb->nh.iph->protocol, &spi, &seq)) < 0) + goto drop; + } while (!err); + + /* Allocate new secpath or COW existing one. */ + + if (!skb->sp || atomic_read(&skb->sp->refcnt) != 1) { + struct sec_path *sp; + sp = secpath_dup(skb->sp); + if (!sp) + goto drop; + if (skb->sp) + secpath_put(skb->sp); + skb->sp = sp; + } + if (xfrm_nr + skb->sp->len > XFRM_MAX_DEPTH) + goto drop; + + memcpy(skb->sp->x+skb->sp->len, xfrm_vec, xfrm_nr*sizeof(struct sec_decap_state)); + skb->sp->len += xfrm_nr; + + if (decaps) { + if (!(skb->dev->flags&IFF_LOOPBACK)) { + dst_release(skb->dst); + skb->dst = NULL; + } + netif_rx(skb); + return 0; + } else { + return -skb->nh.iph->protocol; + } + +drop_unlock: + spin_unlock(&x->lock); + xfrm_state_put(x); +drop: + while (--xfrm_nr >= 0) + xfrm_state_put(xfrm_vec[xfrm_nr].xvec); + + kfree_skb(skb); + return 0; +} |