[IPSEC]: Move flow construction into xfrm_dst_lookup

This patch moves the flow construction from the callers of
xfrm_dst_lookup into that function.  It also changes xfrm_dst_lookup
so that it takes an xfrm state as its argument instead of explicit
addresses.

This removes any address-specific logic from the callers of
xfrm_dst_lookup which is needed to correctly support inter-family
transforms.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 38 insertions, 42 deletions

diff --git a/net/ipv4/xfrm4_policy.c b/net/ipv4/xfrm4_policy.c
index d903c8bdffcd..cebc84731969 100644
--- a/net/ipv4/xfrm4_policy.c
+++ b/net/ipv4/xfrm4_policy.c
@@ -8,7 +8,8 @@
  *
  */
 
-#include <linux/compiler.h>
+#include <linux/err.h>
+#include <linux/kernel.h>
 #include <linux/inetdevice.h>
 #include <net/dst.h>
 #include <net/xfrm.h>
@@ -17,28 +18,44 @@
 static struct dst_ops xfrm4_dst_ops;
 static struct xfrm_policy_afinfo xfrm4_policy_afinfo;
 
-static int xfrm4_dst_lookup(struct xfrm_dst **dst, struct flowi *fl)
+static struct dst_entry *xfrm4_dst_lookup(int tos, xfrm_address_t *saddr,
+                                          xfrm_address_t *daddr)
 {
-        return __ip_route_output_key((struct rtable**)dst, fl);
-}
-
-static int xfrm4_get_saddr(xfrm_address_t *saddr, xfrm_address_t *daddr)
-{
-        struct rtable *rt;
-        struct flowi fl_tunnel = {
+        struct flowi fl = {
                 .nl_u = {
                         .ip4_u = {
+                                .tos = tos,
                                 .daddr = daddr->a4,
                         },
                 },
         };
+        struct dst_entry *dst;
+        struct rtable *rt;
+        int err;
 
-        if (!xfrm4_dst_lookup((struct xfrm_dst **)&rt, &fl_tunnel)) {
-                saddr->a4 = rt->rt_src;
-                dst_release(&rt->u.dst);
-                return 0;
-        }
-        return -EHOSTUNREACH;
+        if (saddr)
+                fl.fl4_src = saddr->a4;
+
+        err = __ip_route_output_key(&rt, &fl);
+        dst = &rt->u.dst;
+        if (err)
+                dst = ERR_PTR(err);
+        return dst;
+}
+
+static int xfrm4_get_saddr(xfrm_address_t *saddr, xfrm_address_t *daddr)
+{
+        struct dst_entry *dst;
+        struct rtable *rt;
+
+        dst = xfrm4_dst_lookup(0, NULL, daddr);
+        if (IS_ERR(dst))
+                return -EHOSTUNREACH;
+
+        rt = (struct rtable *)dst;
+        saddr->a4 = rt->rt_src;
+        dst_release(dst);
+        return 0;
 }
 
 static struct dst_entry *
@@ -73,15 +90,7 @@ __xfrm4_bundle_create(struct xfrm_policy *policy, struct xfrm_state **xfrm, int
         struct dst_entry *dst, *dst_prev;
         struct rtable *rt0 = (struct rtable*)(*dst_p);
         struct rtable *rt = rt0;
-        struct flowi fl_tunnel = {
-                .nl_u = {
-                        .ip4_u = {
-                                .saddr = fl->fl4_src,
-                                .daddr = fl->fl4_dst,
-                                .tos = fl->fl4_tos
-                        }
-                }
-        };
+        int tos = fl->fl4_tos;
         int i;
         int err;
         int header_len = 0;
@@ -119,25 +128,12 @@ __xfrm4_bundle_create(struct xfrm_policy *policy, struct xfrm_state **xfrm, int
                 trailer_len += xfrm[i]->props.trailer_len;
 
                 if (xfrm[i]->props.mode != XFRM_MODE_TRANSPORT) {
-                        unsigned short encap_family = xfrm[i]->props.family;
-                        switch (encap_family) {
-                        case AF_INET:
-                                fl_tunnel.fl4_dst = xfrm[i]->id.daddr.a4;
-                                fl_tunnel.fl4_src = xfrm[i]->props.saddr.a4;
-                                break;
-#if defined(CONFIG_IPV6) || defined (CONFIG_IPV6_MODULE)
-                        case AF_INET6:
-                                ipv6_addr_copy(&fl_tunnel.fl6_dst, (struct in6_addr*)&xfrm[i]->id.daddr.a6);
-                                ipv6_addr_copy(&fl_tunnel.fl6_src, (struct in6_addr*)&xfrm[i]->props.saddr.a6);
-                                break;
-#endif
-                        default:
-                                BUG_ON(1);
-                        }
-                        err = xfrm_dst_lookup((struct xfrm_dst **)&rt,
-                                              &fl_tunnel, encap_family);
-                        if (err)
+                        dst1 = xfrm_dst_lookup(xfrm[i], tos);
+                        err = PTR_ERR(dst1);
+                        if (IS_ERR(dst1))
                                 goto error;
+
+                        rt = (struct rtable *)dst1;
                 } else
                         dst_hold(&rt->u.dst);
         }