1 files changed, 300 insertions, 0 deletions
diff --git a/net/xfrm/xfrm_output.c b/net/xfrm/xfrm_output.c
new file mode 100644
index 000000000..c46162887
--- /dev/null
+++ b/net/xfrm/xfrm_output.c
@@ -0,0 +1,300 @@
+/*
+ * xfrm_output.c - Common IPsec encapsulation code.
+ *
+ * Copyright (c) 2007 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/errno.h>
+#include <linux/module.h>
+#include <linux/netdevice.h>
+#include <linux/netfilter.h>
+#include <linux/skbuff.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <net/dst.h>
+#include <net/xfrm.h>
+
+static int xfrm_output2(struct net *net, struct sock *sk, struct sk_buff *skb);
+
+static int xfrm_skb_check_space(struct sk_buff *skb)
+{
+	struct dst_entry *dst = skb_dst(skb);
+	int nhead = dst->header_len + LL_RESERVED_SPACE(dst->dev)
+		- skb_headroom(skb);
+	int ntail = dst->dev->needed_tailroom - skb_tailroom(skb);
+
+	if (nhead <= 0) {
+		if (ntail <= 0)
+			return 0;
+		nhead = 0;
+	} else if (ntail < 0)
+		ntail = 0;
+
+	return pskb_expand_head(skb, nhead, ntail, GFP_ATOMIC);
+}
+
+/* Children define the path of the packet through the
+ * Linux networking.  Thus, destinations are stackable.
+ */
+
+static struct dst_entry *skb_dst_pop(struct sk_buff *skb)
+{
+	struct dst_entry *child = dst_clone(xfrm_dst_child(skb_dst(skb)));
+
+	skb_dst_drop(skb);
+	return child;
+}
+
+static int xfrm_output_one(struct sk_buff *skb, int err)
+{
+	struct dst_entry *dst = skb_dst(skb);
+	struct xfrm_state *x = dst->xfrm;
+	struct net *net = xs_net(x);
+
+	if (err <= 0)
+		goto resume;
+
+	do {
+		err = xfrm_skb_check_space(skb);
+		if (err) {
+			XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTERROR);
+			goto error_nolock;
+		}
+
+		skb->mark = xfrm_smark_get(skb->mark, x);
+
+		err = x->outer_mode->output(x, skb);
+		if (err) {
+			XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTSTATEMODEERROR);
+			goto error_nolock;
+		}
+
+		spin_lock_bh(&x->lock);
+
+		if (unlikely(x->km.state != XFRM_STATE_VALID)) {
+			XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTSTATEINVALID);
+			err = -EINVAL;
+			goto error;
+		}
+
+		err = xfrm_state_check_expire(x);
+		if (err) {
+			XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTSTATEEXPIRED);
+			goto error;
+		}
+
+		err = x->repl->overflow(x, skb);
+		if (err) {
+			XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTSTATESEQERROR);
+			goto error;
+		}
+
+		x->curlft.bytes += skb->len;
+		x->curlft.packets++;
+
+		spin_unlock_bh(&x->lock);
+
+		skb_dst_force(skb);
+		if (!skb_dst(skb)) {
+			XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTERROR);
+			err = -EHOSTUNREACH;
+			goto error_nolock;
+		}
+
+		if (xfrm_offload(skb)) {
+			x->type_offload->encap(x, skb);
+		} else {
+			/* Inner headers are invalid now. */
+			skb->encapsulation = 0;
+
+			err = x->type->output(x, skb);
+			if (err == -EINPROGRESS)
+				goto out;
+		}
+
+resume:
+		if (err) {
+			XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTSTATEPROTOERROR);
+			goto error_nolock;
+		}
+
+		dst = skb_dst_pop(skb);
+		if (!dst) {
+			XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTERROR);
+			err = -EHOSTUNREACH;
+			goto error_nolock;
+		}
+		skb_dst_set(skb, dst);
+		x = dst->xfrm;
+	} while (x && !(x->outer_mode->flags & XFRM_MODE_FLAG_TUNNEL));
+
+	return 0;
+
+error:
+	spin_unlock_bh(&x->lock);
+error_nolock:
+	kfree_skb(skb);
+out:
+	return err;
+}
+
+int xfrm_output_resume(struct sk_buff *skb, int err)
+{
+	struct net *net = xs_net(skb_dst(skb)->xfrm);
+
+	while (likely((err = xfrm_output_one(skb, err)) == 0)) {
+		nf_reset(skb);
+
+		err = skb_dst(skb)->ops->local_out(net, skb->sk, skb);
+		if (unlikely(err != 1))
+			goto out;
+
+		if (!skb_dst(skb)->xfrm)
+			return dst_output(net, skb->sk, skb);
+
+		err = nf_hook(skb_dst(skb)->ops->family,
+			      NF_INET_POST_ROUTING, net, skb->sk, skb,
+			      NULL, skb_dst(skb)->dev, xfrm_output2);
+		if (unlikely(err != 1))
+			goto out;
+	}
+
+	if (err == -EINPROGRESS)
+		err = 0;
+
+out:
+	return err;
+}
+EXPORT_SYMBOL_GPL(xfrm_output_resume);
+
+static int xfrm_output2(struct net *net, struct sock *sk, struct sk_buff *skb)
+{
+	return xfrm_output_resume(skb, 1);
+}
+
+static int xfrm_output_gso(struct net *net, struct sock *sk, struct sk_buff *skb)
+{
+	struct sk_buff *segs;
+
+	BUILD_BUG_ON(sizeof(*IPCB(skb)) > SKB_SGO_CB_OFFSET);
+	BUILD_BUG_ON(sizeof(*IP6CB(skb)) > SKB_SGO_CB_OFFSET);
+	segs = skb_gso_segment(skb, 0);
+	kfree_skb(skb);
+	if (IS_ERR(segs))
+		return PTR_ERR(segs);
+	if (segs == NULL)
+		return -EINVAL;
+
+	do {
+		struct sk_buff *nskb = segs->next;
+		int err;
+
+		segs->next = NULL;
+		err = xfrm_output2(net, sk, segs);
+
+		if (unlikely(err)) {
+			kfree_skb_list(nskb);
+			return err;
+		}
+
+		segs = nskb;
+	} while (segs);
+
+	return 0;
+}
+
+int xfrm_output(struct sock *sk, struct sk_buff *skb)
+{
+	struct net *net = dev_net(skb_dst(skb)->dev);
+	struct xfrm_state *x = skb_dst(skb)->xfrm;
+	int err;
+
+	secpath_reset(skb);
+
+	if (xfrm_dev_offload_ok(skb, x)) {
+		struct sec_path *sp;
+
+		sp = secpath_dup(skb->sp);
+		if (!sp) {
+			XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTERROR);
+			kfree_skb(skb);
+			return -ENOMEM;
+		}
+		if (skb->sp)
+			secpath_put(skb->sp);
+		skb->sp = sp;
+		skb->encapsulation = 1;
+
+		sp->olen++;
+		sp->xvec[skb->sp->len++] = x;
+		xfrm_state_hold(x);
+
+		if (skb_is_gso(skb)) {
+			if (skb->inner_protocol)
+				return xfrm_output_gso(net, sk, skb);
+
+			skb_shinfo(skb)->gso_type |= SKB_GSO_ESP;
+			goto out;
+		}
+
+		if (x->xso.dev && x->xso.dev->features & NETIF_F_HW_ESP_TX_CSUM)
+			goto out;
+	} else {
+		if (skb_is_gso(skb))
+			return xfrm_output_gso(net, sk, skb);
+	}
+
+	if (skb->ip_summed == CHECKSUM_PARTIAL) {
+		err = skb_checksum_help(skb);
+		if (err) {
+			XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTERROR);
+			kfree_skb(skb);
+			return err;
+		}
+	}
+
+out:
+	return xfrm_output2(net, sk, skb);
+}
+EXPORT_SYMBOL_GPL(xfrm_output);
+
+int xfrm_inner_extract_output(struct xfrm_state *x, struct sk_buff *skb)
+{
+	struct xfrm_mode *inner_mode;
+	if (x->sel.family == AF_UNSPEC)
+		inner_mode = xfrm_ip2inner_mode(x,
+				xfrm_af2proto(skb_dst(skb)->ops->family));
+	else
+		inner_mode = x->inner_mode;
+
+	if (inner_mode == NULL)
+		return -EAFNOSUPPORT;
+	return inner_mode->afinfo->extract_output(x, skb);
+}
+EXPORT_SYMBOL_GPL(xfrm_inner_extract_output);
+
+void xfrm_local_error(struct sk_buff *skb, int mtu)
+{
+	unsigned int proto;
+	struct xfrm_state_afinfo *afinfo;
+
+	if (skb->protocol == htons(ETH_P_IP))
+		proto = AF_INET;
+	else if (skb->protocol == htons(ETH_P_IPV6) &&
+		 skb->sk->sk_family == AF_INET6)
+		proto = AF_INET6;
+	else
+		return;
+
+	afinfo = xfrm_state_get_afinfo(proto);
+	if (afinfo) {
+		afinfo->local_error(skb, mtu);
+		rcu_read_unlock();
+	}
+}
+EXPORT_SYMBOL_GPL(xfrm_local_error);