9 files changed, 193 insertions, 84 deletions

diff --git a/include/net/xfrm.h b/include/net/xfrm.h
index c9345fe3f8d2..138c1868be1d 100644
--- a/include/net/xfrm.h
+++ b/include/net/xfrm.h
@@ -257,6 +257,7 @@ extern int __xfrm_state_delete(struct xfrm_state *x);
 
 struct xfrm_state_afinfo {
         unsigned int            family;
+        unsigned int            proto;
         struct module           *owner;
         struct xfrm_type        *type_map[IPPROTO_MAX];
         struct xfrm_mode        *mode_map[XFRM_MODE_MAX];
@@ -267,6 +268,8 @@ struct xfrm_state_afinfo {
         int                     (*tmpl_sort)(struct xfrm_tmpl **dst, struct xfrm_tmpl **src, int n);
         int                     (*state_sort)(struct xfrm_state **dst, struct xfrm_state **src, int n);
         int                     (*output)(struct sk_buff *skb);
+        int                     (*extract_output)(struct xfrm_state *x,
+                                                  struct sk_buff *skb);
 };
 
 extern int xfrm_state_register_afinfo(struct xfrm_state_afinfo *afinfo);
@@ -312,7 +315,18 @@ struct xfrm_mode {
          * header.  The value of the network header will always point
          * to the top IP header while skb->data will point to the payload.
          */
-        int (*output)(struct xfrm_state *x,struct sk_buff *skb);
+        int (*output2)(struct xfrm_state *x,struct sk_buff *skb);
+
+        /*
+         * This is the actual output entry point.
+         *
+         * For transport mode and equivalent this would be identical to
+         * output2 (which does not need to be set).  While tunnel mode
+         * and equivalent would set this to a tunnel encapsulation function
+         * (xfrm4_prepare_output or xfrm6_prepare_output) that would in turn
+         * call output2.
+         */
+        int (*output)(struct xfrm_state *x, struct sk_buff *skb);
 
         struct xfrm_state_afinfo *afinfo;
         struct module *owner;
@@ -454,6 +468,35 @@ struct xfrm_skb_cb {
 
 #define XFRM_SKB_CB(__skb) ((struct xfrm_skb_cb *)&((__skb)->cb[0]))
 
+/*
+ * This structure is used by the afinfo prepare_input/prepare_output functions
+ * to transmit header information to the mode input/output functions.
+ */
+struct xfrm_mode_skb_cb {
+        union {
+                struct inet_skb_parm h4;
+                struct inet6_skb_parm h6;
+        } header;
+
+        /* Copied from header for IPv4, always set to zero and DF for IPv6. */
+        __be16 id;
+        __be16 frag_off;
+
+        /* TOS for IPv4, class for IPv6. */
+        u8 tos;
+
+        /* TTL for IPv4, hop limitfor IPv6. */
+        u8 ttl;
+
+        /* Protocol for IPv4, NH for IPv6. */
+        u8 protocol;
+
+        /* Used by IPv6 only, zero for IPv4. */
+        u8 flow_lbl[3];
+};
+
+#define XFRM_MODE_SKB_CB(__skb) ((struct xfrm_mode_skb_cb *)&((__skb)->cb[0]))
+
 /* Audit Information */
 struct xfrm_audit
 {
@@ -1051,6 +1094,7 @@ extern void xfrm_replay_notify(struct xfrm_state *x, int event);
 extern int xfrm_state_mtu(struct xfrm_state *x, int mtu);
 extern int xfrm_init_state(struct xfrm_state *x);
 extern int xfrm_output(struct sk_buff *skb);
+extern int xfrm4_extract_header(struct sk_buff *skb);
 extern int xfrm4_rcv_encap(struct sk_buff *skb, int nexthdr, __be32 spi,
                            int encap_type);
 extern int xfrm4_rcv(struct sk_buff *skb);
@@ -1060,9 +1104,12 @@ static inline int xfrm4_rcv_spi(struct sk_buff *skb, int nexthdr, __be32 spi)
         return xfrm4_rcv_encap(skb, nexthdr, spi, 0);
 }
 
+extern int xfrm4_extract_output(struct xfrm_state *x, struct sk_buff *skb);
+extern int xfrm4_prepare_output(struct xfrm_state *x, struct sk_buff *skb);
 extern int xfrm4_output(struct sk_buff *skb);
 extern int xfrm4_tunnel_register(struct xfrm_tunnel *handler, unsigned short family);
 extern int xfrm4_tunnel_deregister(struct xfrm_tunnel *handler, unsigned short family);
+extern int xfrm6_extract_header(struct sk_buff *skb);
 extern int xfrm6_rcv_spi(struct sk_buff *skb, int nexthdr, __be32 spi);
 extern int xfrm6_rcv(struct sk_buff *skb);
 extern int xfrm6_input_addr(struct sk_buff *skb, xfrm_address_t *daddr,
@@ -1072,6 +1119,8 @@ extern int xfrm6_tunnel_deregister(struct xfrm6_tunnel *handler, unsigned short
 extern __be32 xfrm6_tunnel_alloc_spi(xfrm_address_t *saddr);
 extern void xfrm6_tunnel_free_spi(xfrm_address_t *saddr);
 extern __be32 xfrm6_tunnel_spi_lookup(xfrm_address_t *saddr);
+extern int xfrm6_extract_output(struct xfrm_state *x, struct sk_buff *skb);
+extern int xfrm6_prepare_output(struct xfrm_state *x, struct sk_buff *skb);
 extern int xfrm6_output(struct sk_buff *skb);
 extern int xfrm6_find_1stfragopt(struct xfrm_state *x, struct sk_buff *skb,
                                  u8 **prevhdr);
diff --git a/net/ipv4/xfrm4_mode_beet.c b/net/ipv4/xfrm4_mode_beet.c
index e42e122414be..94842adce144 100644
--- a/net/ipv4/xfrm4_mode_beet.c
+++ b/net/ipv4/xfrm4_mode_beet.c
@@ -43,7 +43,17 @@ static int xfrm4_beet_output(struct xfrm_state *x, struct sk_buff *skb)
         ph = (struct ip_beet_phdr *)__skb_pull(skb, sizeof(*iph) - hdrlen);
 
         top_iph = ip_hdr(skb);
-        memmove(top_iph, iph, sizeof(*iph));
+
+        top_iph->ihl = 5;
+        top_iph->version = 4;
+
+        top_iph->protocol = XFRM_MODE_SKB_CB(skb)->protocol;
+        top_iph->tos = XFRM_MODE_SKB_CB(skb)->tos;
+
+        top_iph->id = XFRM_MODE_SKB_CB(skb)->id;
+        top_iph->frag_off = XFRM_MODE_SKB_CB(skb)->frag_off;
+        top_iph->ttl = XFRM_MODE_SKB_CB(skb)->ttl;
+
         if (unlikely(optlen)) {
                 BUG_ON(optlen < 0);
 
@@ -111,7 +121,8 @@ out:
 
 static struct xfrm_mode xfrm4_beet_mode = {
         .input = xfrm4_beet_input,
-        .output = xfrm4_beet_output,
+        .output2 = xfrm4_beet_output,
+        .output = xfrm4_prepare_output,
         .owner = THIS_MODULE,
         .encap = XFRM_MODE_BEET,
         .flags = XFRM_MODE_FLAG_TUNNEL,
diff --git a/net/ipv4/xfrm4_mode_tunnel.c b/net/ipv4/xfrm4_mode_tunnel.c
index 68a9f56ff09f..cc8bbb274e37 100644
--- a/net/ipv4/xfrm4_mode_tunnel.c
+++ b/net/ipv4/xfrm4_mode_tunnel.c
@@ -36,53 +36,37 @@ static inline void ipip6_ecn_decapsulate(struct iphdr *iph, struct sk_buff *skb)
 static int xfrm4_tunnel_output(struct xfrm_state *x, struct sk_buff *skb)
 {
         struct dst_entry *dst = skb->dst;
-        struct xfrm_dst *xdst = (struct xfrm_dst*)dst;
-        struct iphdr *iph, *top_iph;
+        struct iphdr *top_iph;
         int flags;
 
-        iph = ip_hdr(skb);
-
         skb_set_network_header(skb, -x->props.header_len);
         skb->mac_header = skb->network_header +
                           offsetof(struct iphdr, protocol);
-        skb->transport_header = skb->network_header + sizeof(*iph);
+        skb->transport_header = skb->network_header + sizeof(*top_iph);
         top_iph = ip_hdr(skb);
 
         top_iph->ihl = 5;
         top_iph->version = 4;
 
-        flags = x->props.flags;
+        top_iph->protocol = x->inner_mode->afinfo->proto;
 
         /* DS disclosed */
-        if (xdst->route->ops->family == AF_INET) {
-                top_iph->protocol = IPPROTO_IPIP;
-                top_iph->tos = INET_ECN_encapsulate(iph->tos, iph->tos);
-                top_iph->frag_off = (flags & XFRM_STATE_NOPMTUDISC) ?
-                        0 : (iph->frag_off & htons(IP_DF));
-        }
-#if defined(CONFIG_IPV6) || defined (CONFIG_IPV6_MODULE)
-        else {
-                struct ipv6hdr *ipv6h = (struct ipv6hdr*)iph;
-                top_iph->protocol = IPPROTO_IPV6;
-                top_iph->tos = INET_ECN_encapsulate(iph->tos, ipv6_get_dsfield(ipv6h));
-                top_iph->frag_off = 0;
-        }
-#endif
+        top_iph->tos = INET_ECN_encapsulate(XFRM_MODE_SKB_CB(skb)->tos,
+                                            XFRM_MODE_SKB_CB(skb)->tos);
 
+        flags = x->props.flags;
         if (flags & XFRM_STATE_NOECN)
                 IP_ECN_clear(top_iph);
 
-        if (!top_iph->frag_off)
-                __ip_select_ident(top_iph, dst->child, 0);
+        top_iph->frag_off = (flags & XFRM_STATE_NOPMTUDISC) ?
+                            0 : XFRM_MODE_SKB_CB(skb)->frag_off;
+        ip_select_ident(top_iph, dst->child, NULL);
 
         top_iph->ttl = dst_metric(dst->child, RTAX_HOPLIMIT);
 
         top_iph->saddr = x->props.saddr.a4;
         top_iph->daddr = x->id.daddr.a4;
 
-        skb->protocol = htons(ETH_P_IP);
-
-        memset(&(IPCB(skb)->opt), 0, sizeof(struct ip_options));
         return 0;
 }
 
@@ -136,7 +120,8 @@ out:
 
 static struct xfrm_mode xfrm4_tunnel_mode = {
         .input = xfrm4_tunnel_input,
-        .output = xfrm4_tunnel_output,
+        .output2 = xfrm4_tunnel_output,
+        .output = xfrm4_prepare_output,
         .owner = THIS_MODULE,
         .encap = XFRM_MODE_TUNNEL,
         .flags = XFRM_MODE_FLAG_TUNNEL,
diff --git a/net/ipv4/xfrm4_output.c b/net/ipv4/xfrm4_output.c
index c4a7156962bd..13fd11335e28 100644
--- a/net/ipv4/xfrm4_output.c
+++ b/net/ipv4/xfrm4_output.c
@@ -8,11 +8,12 @@
  * 2 of the License, or (at your option) any later version.
  */
 
-#include <linux/compiler.h>
 #include <linux/if_ether.h>
 #include <linux/kernel.h>
+#include <linux/module.h>
 #include <linux/skbuff.h>
 #include <linux/netfilter_ipv4.h>
+#include <net/dst.h>
 #include <net/ip.h>
 #include <net/xfrm.h>
 #include <net/icmp.h>
@@ -25,8 +26,6 @@ static int xfrm4_tunnel_check_size(struct sk_buff *skb)
         if (IPCB(skb)->flags & IPSKB_XFRM_TUNNEL_SIZE)
                 goto out;
 
-        IPCB(skb)->flags |= IPSKB_XFRM_TUNNEL_SIZE;
-
         if (!(ip_hdr(skb)->frag_off & htons(IP_DF)) || skb->local_df)
                 goto out;
 
@@ -40,19 +39,39 @@ out:
         return ret;
 }
 
+int xfrm4_extract_output(struct xfrm_state *x, struct sk_buff *skb)
+{
+        int err;
+
+        err = xfrm4_tunnel_check_size(skb);
+        if (err)
+                return err;
+
+        return xfrm4_extract_header(skb);
+}
+
+int xfrm4_prepare_output(struct xfrm_state *x, struct sk_buff *skb)
+{
+        int err;
+
+        err = x->inner_mode->afinfo->extract_output(x, skb);
+        if (err)
+                return err;
+
+        memset(IPCB(skb), 0, sizeof(*IPCB(skb)));
+        IPCB(skb)->flags |= IPSKB_XFRM_TUNNEL_SIZE;
+
+        skb->protocol = htons(ETH_P_IP);
+
+        return x->outer_mode->output2(x, skb);
+}
+EXPORT_SYMBOL(xfrm4_prepare_output);
+
 static inline int xfrm4_output_one(struct sk_buff *skb)
 {
-        struct dst_entry *dst = skb->dst;
-        struct xfrm_state *x = dst->xfrm;
         struct iphdr *iph;
         int err;
 
-        if (x->outer_mode->flags & XFRM_MODE_FLAG_TUNNEL) {
-                err = xfrm4_tunnel_check_size(skb);
-                if (err)
-                        goto error_nolock;
-        }
-
         err = xfrm_output(skb);
         if (err)
                 goto error_nolock;
diff --git a/net/ipv4/xfrm4_state.c b/net/ipv4/xfrm4_state.c
index 13d54a1c3337..e6030e74ff65 100644
--- a/net/ipv4/xfrm4_state.c
+++ b/net/ipv4/xfrm4_state.c
@@ -47,12 +47,29 @@ __xfrm4_init_tempsel(struct xfrm_state *x, struct flowi *fl,
         x->props.family = AF_INET;
 }
 
+int xfrm4_extract_header(struct sk_buff *skb)
+{
+        struct iphdr *iph = ip_hdr(skb);
+
+        XFRM_MODE_SKB_CB(skb)->id = iph->id;
+        XFRM_MODE_SKB_CB(skb)->frag_off = iph->frag_off;
+        XFRM_MODE_SKB_CB(skb)->tos = iph->tos;
+        XFRM_MODE_SKB_CB(skb)->ttl = iph->ttl;
+        XFRM_MODE_SKB_CB(skb)->protocol = iph->protocol;
+        memset(XFRM_MODE_SKB_CB(skb)->flow_lbl, 0,
+               sizeof(XFRM_MODE_SKB_CB(skb)->flow_lbl));
+
+        return 0;
+}
+
 static struct xfrm_state_afinfo xfrm4_state_afinfo = {
         .family                 = AF_INET,
+        .proto                  = IPPROTO_IPIP,
         .owner                  = THIS_MODULE,
         .init_flags             = xfrm4_init_flags,
         .init_tempsel           = __xfrm4_init_tempsel,
         .output                 = xfrm4_output,
+        .extract_output         = xfrm4_extract_output,
 };
 
 void __init xfrm4_state_init(void)
diff --git a/net/ipv6/xfrm6_mode_beet.c b/net/ipv6/xfrm6_mode_beet.c
index 2bfb4f05c14c..4988ed9c76c6 100644
--- a/net/ipv6/xfrm6_mode_beet.c
+++ b/net/ipv6/xfrm6_mode_beet.c
@@ -25,25 +25,24 @@
  */
 static int xfrm6_beet_output(struct xfrm_state *x, struct sk_buff *skb)
 {
-        struct ipv6hdr *iph, *top_iph;
-        u8 *prevhdr;
-        int hdr_len;
+        struct ipv6hdr *top_iph;
 
-        iph = ipv6_hdr(skb);
-
-        hdr_len = ip6_find_1stfragopt(skb, &prevhdr);
-
-        skb_set_mac_header(skb, (prevhdr - x->props.header_len) - skb->data);
         skb_set_network_header(skb, -x->props.header_len);
-        skb->transport_header = skb->network_header + hdr_len;
-        __skb_pull(skb, hdr_len);
-
+        skb->mac_header = skb->network_header +
+                          offsetof(struct ipv6hdr, nexthdr);
+        skb->transport_header = skb->network_header + sizeof(*top_iph);
         top_iph = ipv6_hdr(skb);
-        memmove(top_iph, iph, hdr_len);
 
+        top_iph->version = 6;
+
+        memcpy(top_iph->flow_lbl, XFRM_MODE_SKB_CB(skb)->flow_lbl,
+               sizeof(top_iph->flow_lbl));
+        top_iph->nexthdr = XFRM_MODE_SKB_CB(skb)->protocol;
+
+        ipv6_change_dsfield(top_iph, 0, XFRM_MODE_SKB_CB(skb)->tos);
+        top_iph->hop_limit = XFRM_MODE_SKB_CB(skb)->ttl;
         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;
 }
 
@@ -76,7 +75,8 @@ out:
 
 static struct xfrm_mode xfrm6_beet_mode = {
         .input = xfrm6_beet_input,
-        .output = xfrm6_beet_output,
+        .output2 = xfrm6_beet_output,
+        .output = xfrm6_prepare_output,
         .owner = THIS_MODULE,
         .encap = XFRM_MODE_BEET,
         .flags = XFRM_MODE_FLAG_TUNNEL,
diff --git a/net/ipv6/xfrm6_mode_tunnel.c b/net/ipv6/xfrm6_mode_tunnel.c
index 9a43ea722481..d45ce5d44197 100644
--- a/net/ipv6/xfrm6_mode_tunnel.c
+++ b/net/ipv6/xfrm6_mode_tunnel.c
@@ -38,33 +38,22 @@ static inline void ip6ip_ecn_decapsulate(struct sk_buff *skb)
 static int xfrm6_tunnel_output(struct xfrm_state *x, struct sk_buff *skb)
 {
         struct dst_entry *dst = skb->dst;
-        struct xfrm_dst *xdst = (struct xfrm_dst*)dst;
-        struct ipv6hdr *iph, *top_iph;
+        struct ipv6hdr *top_iph;
         int dsfield;
 
-        iph = ipv6_hdr(skb);
-
         skb_set_network_header(skb, -x->props.header_len);
         skb->mac_header = skb->network_header +
                           offsetof(struct ipv6hdr, nexthdr);
-        skb->transport_header = skb->network_header + sizeof(*iph);
+        skb->transport_header = skb->network_header + sizeof(*top_iph);
         top_iph = ipv6_hdr(skb);
 
         top_iph->version = 6;
-        if (xdst->route->ops->family == AF_INET6) {
-                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];
-                top_iph->nexthdr = IPPROTO_IPV6;
-        } else {
-                top_iph->priority = 0;
-                top_iph->flow_lbl[0] = 0;
-                top_iph->flow_lbl[1] = 0;
-                top_iph->flow_lbl[2] = 0;
-                top_iph->nexthdr = IPPROTO_IPIP;
-        }
-        dsfield = ipv6_get_dsfield(top_iph);
+
+        memcpy(top_iph->flow_lbl, XFRM_MODE_SKB_CB(skb)->flow_lbl,
+               sizeof(top_iph->flow_lbl));
+        top_iph->nexthdr = x->inner_mode->afinfo->proto;
+
+        dsfield = XFRM_MODE_SKB_CB(skb)->tos;
         dsfield = INET_ECN_encapsulate(dsfield, dsfield);
         if (x->props.flags & XFRM_STATE_NOECN)
                 dsfield &= ~INET_ECN_MASK;
@@ -72,7 +61,6 @@ static int xfrm6_tunnel_output(struct xfrm_state *x, struct sk_buff *skb)
         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);
-        skb->protocol = htons(ETH_P_IPV6);
         return 0;
 }
 
@@ -116,7 +104,8 @@ out:
 
 static struct xfrm_mode xfrm6_tunnel_mode = {
         .input = xfrm6_tunnel_input,
-        .output = xfrm6_tunnel_output,
+        .output2 = xfrm6_tunnel_output,
+        .output = xfrm6_prepare_output,
         .owner = THIS_MODULE,
         .encap = XFRM_MODE_TUNNEL,
         .flags = XFRM_MODE_FLAG_TUNNEL,
diff --git a/net/ipv6/xfrm6_output.c b/net/ipv6/xfrm6_output.c
index 656976760ad4..bc2e80e3b0b1 100644
--- a/net/ipv6/xfrm6_output.c
+++ b/net/ipv6/xfrm6_output.c
@@ -10,10 +10,12 @@
  */
 
 #include <linux/if_ether.h>
-#include <linux/compiler.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
 #include <linux/skbuff.h>
 #include <linux/icmpv6.h>
 #include <linux/netfilter_ipv6.h>
+#include <net/dst.h>
 #include <net/ipv6.h>
 #include <net/xfrm.h>
 
@@ -43,19 +45,38 @@ static int xfrm6_tunnel_check_size(struct sk_buff *skb)
         return ret;
 }
 
+int xfrm6_extract_output(struct xfrm_state *x, struct sk_buff *skb)
+{
+        int err;
+
+        err = xfrm6_tunnel_check_size(skb);
+        if (err)
+                return err;
+
+        return xfrm6_extract_header(skb);
+}
+
+int xfrm6_prepare_output(struct xfrm_state *x, struct sk_buff *skb)
+{
+        int err;
+
+        err = x->inner_mode->afinfo->extract_output(x, skb);
+        if (err)
+                return err;
+
+        memset(IP6CB(skb), 0, sizeof(*IP6CB(skb)));
+
+        skb->protocol = htons(ETH_P_IPV6);
+
+        return x->outer_mode->output2(x, skb);
+}
+EXPORT_SYMBOL(xfrm6_prepare_output);
+
 static inline int xfrm6_output_one(struct sk_buff *skb)
 {
-        struct dst_entry *dst = skb->dst;
-        struct xfrm_state *x = dst->xfrm;
         struct ipv6hdr *iph;
         int err;
 
-        if (x->outer_mode->flags & XFRM_MODE_FLAG_TUNNEL) {
-                err = xfrm6_tunnel_check_size(skb);
-                if (err)
-                        goto error_nolock;
-        }
-
         err = xfrm_output(skb);
         if (err)
                 goto error_nolock;
diff --git a/net/ipv6/xfrm6_state.c b/net/ipv6/xfrm6_state.c
index b392bee396f1..98b05f472322 100644
--- a/net/ipv6/xfrm6_state.c
+++ b/net/ipv6/xfrm6_state.c
@@ -14,6 +14,7 @@
 #include <net/xfrm.h>
 #include <linux/pfkeyv2.h>
 #include <linux/ipsec.h>
+#include <net/dsfield.h>
 #include <net/ipv6.h>
 #include <net/addrconf.h>
 
@@ -168,13 +169,30 @@ __xfrm6_tmpl_sort(struct xfrm_tmpl **dst, struct xfrm_tmpl **src, int n)
         return 0;
 }
 
+int xfrm6_extract_header(struct sk_buff *skb)
+{
+        struct ipv6hdr *iph = ipv6_hdr(skb);
+
+        XFRM_MODE_SKB_CB(skb)->id = 0;
+        XFRM_MODE_SKB_CB(skb)->frag_off = htons(IP_DF);
+        XFRM_MODE_SKB_CB(skb)->tos = ipv6_get_dsfield(iph);
+        XFRM_MODE_SKB_CB(skb)->ttl = iph->hop_limit;
+        XFRM_MODE_SKB_CB(skb)->protocol = iph->nexthdr;
+        memcpy(XFRM_MODE_SKB_CB(skb)->flow_lbl, iph->flow_lbl,
+               sizeof(XFRM_MODE_SKB_CB(skb)->flow_lbl));
+
+        return 0;
+}
+
 static struct xfrm_state_afinfo xfrm6_state_afinfo = {
         .family                 = AF_INET6,
+        .proto                  = IPPROTO_IPV6,
         .owner                  = THIS_MODULE,
         .init_tempsel           = __xfrm6_init_tempsel,
         .tmpl_sort              = __xfrm6_tmpl_sort,
         .state_sort             = __xfrm6_state_sort,
         .output                 = xfrm6_output,
+        .extract_output         = xfrm6_extract_output,
 };
 
 void __init xfrm6_state_init(void)