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 000000000000..2d3849c38a0f
--- /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;
+}