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