[IPSEC] xfrm: Abstract out encapsulation modes
This patch adds the structure xfrm_mode. It is meant to represent
the operations carried out by transport/tunnel modes.
By doing this we allow additional encapsulation modes to be added
without clogging up the xfrm_input/xfrm_output paths.
Candidate modes include 4-to-6 tunnel mode, 6-to-4 tunnel mode, and
BEET modes.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv6/Kconfig b/net/ipv6/Kconfig
index f8a107a..e923d4d 100644
--- a/net/ipv6/Kconfig
+++ b/net/ipv6/Kconfig
@@ -106,6 +106,26 @@
tristate
default n
+config INET6_XFRM_MODE_TRANSPORT
+ tristate "IPv6: IPsec transport mode"
+ depends on IPV6
+ default IPV6
+ select XFRM
+ ---help---
+ Support for IPsec transport mode.
+
+ If unsure, say Y.
+
+config INET6_XFRM_MODE_TUNNEL
+ tristate "IPv6: IPsec tunnel mode"
+ depends on IPV6
+ default IPV6
+ select XFRM
+ ---help---
+ Support for IPsec tunnel mode.
+
+ If unsure, say Y.
+
config IPV6_TUNNEL
tristate "IPv6: IPv6-in-IPv6 tunnel"
select INET6_TUNNEL
diff --git a/net/ipv6/Makefile b/net/ipv6/Makefile
index a760b09..386e0a6 100644
--- a/net/ipv6/Makefile
+++ b/net/ipv6/Makefile
@@ -20,6 +20,8 @@
obj-$(CONFIG_INET6_IPCOMP) += ipcomp6.o
obj-$(CONFIG_INET6_XFRM_TUNNEL) += xfrm6_tunnel.o
obj-$(CONFIG_INET6_TUNNEL) += tunnel6.o
+obj-$(CONFIG_INET6_XFRM_MODE_TRANSPORT) += xfrm6_mode_transport.o
+obj-$(CONFIG_INET6_XFRM_MODE_TUNNEL) += xfrm6_mode_tunnel.o
obj-$(CONFIG_NETFILTER) += netfilter/
obj-$(CONFIG_IPV6_TUNNEL) += ip6_tunnel.o
diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
index e460489..416f6e4 100644
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -39,6 +39,7 @@
#include <linux/in6.h>
#include <linux/tcp.h>
#include <linux/route.h>
+#include <linux/module.h>
#include <linux/netfilter.h>
#include <linux/netfilter_ipv6.h>
@@ -488,6 +489,7 @@
return offset;
}
+EXPORT_SYMBOL_GPL(ip6_find_1stfragopt);
static int ip6_fragment(struct sk_buff *skb, int (*output)(struct sk_buff *))
{
diff --git a/net/ipv6/xfrm6_input.c b/net/ipv6/xfrm6_input.c
index 00cfdee..0405d74 100644
--- a/net/ipv6/xfrm6_input.c
+++ b/net/ipv6/xfrm6_input.c
@@ -13,21 +13,9 @@
#include <linux/string.h>
#include <linux/netfilter.h>
#include <linux/netfilter_ipv6.h>
-#include <net/dsfield.h>
-#include <net/inet_ecn.h>
-#include <net/ip.h>
#include <net/ipv6.h>
#include <net/xfrm.h>
-static inline void ipip6_ecn_decapsulate(struct sk_buff *skb)
-{
- struct ipv6hdr *outer_iph = skb->nh.ipv6h;
- struct ipv6hdr *inner_iph = skb->h.ipv6h;
-
- if (INET_ECN_is_ce(ipv6_get_dsfield(outer_iph)))
- IP6_ECN_set_ce(inner_iph);
-}
-
int xfrm6_rcv_spi(struct sk_buff *skb, u32 spi)
{
int err;
@@ -81,21 +69,10 @@
xfrm_vec[xfrm_nr++] = x;
+ if (x->mode->input(x, skb))
+ goto drop;
+
if (x->props.mode) { /* XXX */
- if (nexthdr != IPPROTO_IPV6)
- goto drop;
- if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
- goto drop;
- if (skb_cloned(skb) &&
- pskb_expand_head(skb, 0, 0, GFP_ATOMIC))
- goto drop;
- if (x->props.flags & XFRM_STATE_DECAP_DSCP)
- ipv6_copy_dscp(skb->nh.ipv6h, skb->h.ipv6h);
- if (!(x->props.flags & XFRM_STATE_NOECN))
- ipip6_ecn_decapsulate(skb);
- skb->mac.raw = memmove(skb->data - skb->mac_len,
- skb->mac.raw, skb->mac_len);
- skb->nh.raw = skb->data;
decaps = 1;
break;
}
diff --git a/net/ipv6/xfrm6_mode_transport.c b/net/ipv6/xfrm6_mode_transport.c
new file mode 100644
index 0000000..5efbbae
--- /dev/null
+++ b/net/ipv6/xfrm6_mode_transport.c
@@ -0,0 +1,73 @@
+/*
+ * xfrm6_mode_transport.c - Transport mode encapsulation for IPv6.
+ *
+ * Copyright (C) 2002 USAGI/WIDE Project
+ * Copyright (c) 2004-2006 Herbert Xu <herbert@gondor.apana.org.au>
+ */
+
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/skbuff.h>
+#include <linux/stringify.h>
+#include <net/dst.h>
+#include <net/ipv6.h>
+#include <net/xfrm.h>
+
+/* Add encapsulation header.
+ *
+ * The IP header and mutable extension headers will be moved forward to make
+ * space for the encapsulation header.
+ *
+ * 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 int xfrm6_transport_output(struct sk_buff *skb)
+{
+ struct xfrm_state *x = skb->dst->xfrm;
+ struct ipv6hdr *iph;
+ u8 *prevhdr;
+ int hdr_len;
+
+ skb_push(skb, x->props.header_len);
+ iph = skb->nh.ipv6h;
+
+ 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 0;
+}
+
+static int xfrm6_transport_input(struct xfrm_state *x, struct sk_buff *skb)
+{
+ return 0;
+}
+
+static struct xfrm_mode xfrm6_transport_mode = {
+ .input = xfrm6_transport_input,
+ .output = xfrm6_transport_output,
+ .owner = THIS_MODULE,
+ .encap = XFRM_MODE_TRANSPORT,
+};
+
+static int __init xfrm6_transport_init(void)
+{
+ return xfrm_register_mode(&xfrm6_transport_mode, AF_INET6);
+}
+
+static void __exit xfrm6_transport_exit(void)
+{
+ int err;
+
+ err = xfrm_unregister_mode(&xfrm6_transport_mode, AF_INET6);
+ BUG_ON(err);
+}
+
+module_init(xfrm6_transport_init);
+module_exit(xfrm6_transport_exit);
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_XFRM_MODE(AF_INET6, XFRM_MODE_TRANSPORT);
diff --git a/net/ipv6/xfrm6_mode_tunnel.c b/net/ipv6/xfrm6_mode_tunnel.c
new file mode 100644
index 0000000..8af79be2
--- /dev/null
+++ b/net/ipv6/xfrm6_mode_tunnel.c
@@ -0,0 +1,121 @@
+/*
+ * xfrm6_mode_tunnel.c - Tunnel mode encapsulation for IPv6.
+ *
+ * Copyright (C) 2002 USAGI/WIDE Project
+ * Copyright (c) 2004-2006 Herbert Xu <herbert@gondor.apana.org.au>
+ */
+
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/skbuff.h>
+#include <linux/stringify.h>
+#include <net/dsfield.h>
+#include <net/dst.h>
+#include <net/inet_ecn.h>
+#include <net/ipv6.h>
+#include <net/xfrm.h>
+
+static inline void ipip6_ecn_decapsulate(struct sk_buff *skb)
+{
+ struct ipv6hdr *outer_iph = skb->nh.ipv6h;
+ struct ipv6hdr *inner_iph = skb->h.ipv6h;
+
+ if (INET_ECN_is_ce(ipv6_get_dsfield(outer_iph)))
+ IP6_ECN_set_ce(inner_iph);
+}
+
+/* Add encapsulation header.
+ *
+ * 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 int xfrm6_tunnel_output(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;
+
+ 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);
+ return 0;
+}
+
+static int xfrm6_tunnel_input(struct xfrm_state *x, struct sk_buff *skb)
+{
+ int err = -EINVAL;
+
+ if (skb->nh.raw[IP6CB(skb)->nhoff] != IPPROTO_IPV6)
+ goto out;
+ if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
+ goto out;
+
+ if (skb_cloned(skb) &&
+ (err = pskb_expand_head(skb, 0, 0, GFP_ATOMIC)))
+ goto out;
+
+ if (x->props.flags & XFRM_STATE_DECAP_DSCP)
+ ipv6_copy_dscp(skb->nh.ipv6h, skb->h.ipv6h);
+ if (!(x->props.flags & XFRM_STATE_NOECN))
+ ipip6_ecn_decapsulate(skb);
+ skb->mac.raw = memmove(skb->data - skb->mac_len,
+ skb->mac.raw, skb->mac_len);
+ skb->nh.raw = skb->data;
+ err = 0;
+
+out:
+ return err;
+}
+
+static struct xfrm_mode xfrm6_tunnel_mode = {
+ .input = xfrm6_tunnel_input,
+ .output = xfrm6_tunnel_output,
+ .owner = THIS_MODULE,
+ .encap = XFRM_MODE_TUNNEL,
+};
+
+static int __init xfrm6_tunnel_init(void)
+{
+ return xfrm_register_mode(&xfrm6_tunnel_mode, AF_INET6);
+}
+
+static void __exit xfrm6_tunnel_exit(void)
+{
+ int err;
+
+ err = xfrm_unregister_mode(&xfrm6_tunnel_mode, AF_INET6);
+ BUG_ON(err);
+}
+
+module_init(xfrm6_tunnel_init);
+module_exit(xfrm6_tunnel_exit);
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_XFRM_MODE(AF_INET6, XFRM_MODE_TUNNEL);
diff --git a/net/ipv6/xfrm6_output.c b/net/ipv6/xfrm6_output.c
index 8024217..16e8425 100644
--- a/net/ipv6/xfrm6_output.c
+++ b/net/ipv6/xfrm6_output.c
@@ -14,68 +14,9 @@
#include <linux/spinlock.h>
#include <linux/icmpv6.h>
#include <linux/netfilter_ipv6.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;
@@ -118,7 +59,9 @@
if (err)
goto error;
- xfrm6_encap(skb);
+ err = x->mode->output(skb);
+ if (err)
+ goto error;
err = x->type->output(x, skb);
if (err)
