1 files changed, 143 insertions, 0 deletions

diff --git a/net/ipv6/xfrm6_output.c b/net/ipv6/xfrm6_output.c
new file mode 100644
index 000000000000..601a148f60f3
--- /dev/null
+++ b/net/ipv6/xfrm6_output.c
@@ -0,0 +1,143 @@
+/*
+ * xfrm6_output.c - Common IPsec encapsulation code for IPv6.
+ * Copyright (C) 2002 USAGI/WIDE Project
+ * Copyright (c) 2004 Herbert Xu <herbert@gondor.apana.org.au>
+ * 
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/skbuff.h>
+#include <linux/spinlock.h>
+#include <linux/icmpv6.h>
+#include <net/dsfield.h>
+#include <net/inet_ecn.h>
+#include <net/ipv6.h>
+#include <net/xfrm.h>
+
+/* Add encapsulation header.
+ *
+ * In transport mode, the IP header and mutable extension headers will be moved
+ * forward to make space for the encapsulation header.
+ *
+ * In tunnel mode, the top IP header will be constructed per RFC 2401.
+ * The following fields in it shall be filled in by x->type->output:
+ *      payload_len
+ *
+ * On exit, skb->h will be set to the start of the encapsulation header to be
+ * filled in by x->type->output and skb->nh will be set to the nextheader field
+ * of the extension header directly preceding the encapsulation header, or in
+ * its absence, that of the top IP header.  The value of skb->data will always
+ * point to the top IP header.
+ */
+static void xfrm6_encap(struct sk_buff *skb)
+{
+        struct dst_entry *dst = skb->dst;
+        struct xfrm_state *x = dst->xfrm;
+        struct ipv6hdr *iph, *top_iph;
+        int dsfield;
+
+        skb_push(skb, x->props.header_len);
+        iph = skb->nh.ipv6h;
+
+        if (!x->props.mode) {
+                u8 *prevhdr;
+                int hdr_len;
+
+                hdr_len = ip6_find_1stfragopt(skb, &prevhdr);
+                skb->nh.raw = prevhdr - x->props.header_len;
+                skb->h.raw = skb->data + hdr_len;
+                memmove(skb->data, iph, hdr_len);
+                return;
+        }
+
+        skb->nh.raw = skb->data;
+        top_iph = skb->nh.ipv6h;
+        skb->nh.raw = &top_iph->nexthdr;
+        skb->h.ipv6h = top_iph + 1;
+
+        top_iph->version = 6;
+        top_iph->priority = iph->priority;
+        top_iph->flow_lbl[0] = iph->flow_lbl[0];
+        top_iph->flow_lbl[1] = iph->flow_lbl[1];
+        top_iph->flow_lbl[2] = iph->flow_lbl[2];
+        dsfield = ipv6_get_dsfield(top_iph);
+        dsfield = INET_ECN_encapsulate(dsfield, dsfield);
+        if (x->props.flags & XFRM_STATE_NOECN)
+                dsfield &= ~INET_ECN_MASK;
+        ipv6_change_dsfield(top_iph, 0, dsfield);
+        top_iph->nexthdr = IPPROTO_IPV6; 
+        top_iph->hop_limit = dst_metric(dst->child, RTAX_HOPLIMIT);
+        ipv6_addr_copy(&top_iph->saddr, (struct in6_addr *)&x->props.saddr);
+        ipv6_addr_copy(&top_iph->daddr, (struct in6_addr *)&x->id.daddr);
+}
+
+static int xfrm6_tunnel_check_size(struct sk_buff *skb)
+{
+        int mtu, ret = 0;
+        struct dst_entry *dst = skb->dst;
+
+        mtu = dst_mtu(dst);
+        if (mtu < IPV6_MIN_MTU)
+                mtu = IPV6_MIN_MTU;
+
+        if (skb->len > mtu) {
+                icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu, skb->dev);
+                ret = -EMSGSIZE;
+        }
+
+        return ret;
+}
+
+int xfrm6_output(struct sk_buff *skb)
+{
+        struct dst_entry *dst = skb->dst;
+        struct xfrm_state *x = dst->xfrm;
+        int err;
+        
+        if (skb->ip_summed == CHECKSUM_HW) {
+                err = skb_checksum_help(skb, 0);
+                if (err)
+                        goto error_nolock;
+        }
+
+        if (x->props.mode) {
+                err = xfrm6_tunnel_check_size(skb);
+                if (err)
+                        goto error_nolock;
+        }
+
+        spin_lock_bh(&x->lock);
+        err = xfrm_state_check(x, skb);
+        if (err)
+                goto error;
+
+        xfrm6_encap(skb);
+
+        err = x->type->output(x, skb);
+        if (err)
+                goto error;
+
+        x->curlft.bytes += skb->len;
+        x->curlft.packets++;
+
+        spin_unlock_bh(&x->lock);
+
+        skb->nh.raw = skb->data;
+        
+        if (!(skb->dst = dst_pop(dst))) {
+                err = -EHOSTUNREACH;
+                goto error_nolock;
+        }
+        err = NET_XMIT_BYPASS;
+
+out_exit:
+        return err;
+error:
+        spin_unlock_bh(&x->lock);
+error_nolock:
+        kfree_skb(skb);
+        goto out_exit;
+}