[XFRM]: Fix wildcard as tunnel source

Hashing SAs by source address breaks templates with wildcards as tunnel
source since the source address used for hashing/lookup is still 0/0.
Move source address lookup to xfrm_tmpl_resolve_one() so we can use the
real address in the lookup.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

5 files changed, 62 insertions, 31 deletions

diff --git a/net/ipv4/xfrm4_policy.c b/net/ipv4/xfrm4_policy.c
index 479598566f1d..eabcd27b1767 100644
--- a/net/ipv4/xfrm4_policy.c
+++ b/net/ipv4/xfrm4_policy.c
@@ -21,6 +21,25 @@ static int xfrm4_dst_lookup(struct xfrm_dst **dst, struct flowi *fl)
         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 = {
+                .nl_u = {
+                        .ip4_u = {
+                                .daddr = daddr->a4,
+                        },
+                },
+        };
+
+        if (!xfrm4_dst_lookup((struct xfrm_dst **)&rt, &fl_tunnel)) {
+                saddr->a4 = rt->rt_src;
+                dst_release(&rt->u.dst);
+                return 0;
+        }
+        return -EHOSTUNREACH;
+}
+
 static struct dst_entry *
 __xfrm4_find_bundle(struct flowi *fl, struct xfrm_policy *policy)
 {
@@ -298,6 +317,7 @@ static struct xfrm_policy_afinfo xfrm4_policy_afinfo = {
         .family =               AF_INET,
         .dst_ops =              &xfrm4_dst_ops,
         .dst_lookup =           xfrm4_dst_lookup,
+        .get_saddr =            xfrm4_get_saddr,
         .find_bundle =          __xfrm4_find_bundle,
         .bundle_create =        __xfrm4_bundle_create,
         .decode_session =       _decode_session4,
diff --git a/net/ipv4/xfrm4_state.c b/net/ipv4/xfrm4_state.c
index 6a2a4ab42772..fe2034494d08 100644
--- a/net/ipv4/xfrm4_state.c
+++ b/net/ipv4/xfrm4_state.c
@@ -42,21 +42,6 @@ __xfrm4_init_tempsel(struct xfrm_state *x, struct flowi *fl,
         x->props.saddr = tmpl->saddr;
         if (x->props.saddr.a4 == 0)
                 x->props.saddr.a4 = saddr->a4;
-        if (tmpl->mode == XFRM_MODE_TUNNEL && x->props.saddr.a4 == 0) {
-                struct rtable *rt;
-                struct flowi fl_tunnel = {
-                        .nl_u = {
-                                .ip4_u = {
-                                        .daddr = x->id.daddr.a4,
-                                }
-                        }
-                };
-                if (!xfrm_dst_lookup((struct xfrm_dst **)&rt,
-                                     &fl_tunnel, AF_INET)) {
-                        x->props.saddr.a4 = rt->rt_src;
-                        dst_release(&rt->u.dst);
-                }
-        }
         x->props.mode = tmpl->mode;
         x->props.reqid = tmpl->reqid;
         x->props.family = AF_INET;
diff --git a/net/ipv6/xfrm6_policy.c b/net/ipv6/xfrm6_policy.c
index 9391c4c94feb..6a252e2134d1 100644
--- a/net/ipv6/xfrm6_policy.c
+++ b/net/ipv6/xfrm6_policy.c
@@ -34,6 +34,26 @@ static int xfrm6_dst_lookup(struct xfrm_dst **dst, struct flowi *fl)
         return err;
 }
 
+static int xfrm6_get_saddr(xfrm_address_t *saddr, xfrm_address_t *daddr)
+{
+        struct rt6_info *rt;
+        struct flowi fl_tunnel = {
+                .nl_u = {
+                        .ip6_u = {
+                                .daddr = *(struct in6_addr *)&daddr->a6,
+                        },
+                },
+        };
+
+        if (!xfrm6_dst_lookup((struct xfrm_dst **)&rt, &fl_tunnel)) {
+                ipv6_get_saddr(&rt->u.dst, (struct in6_addr *)&daddr->a6,
+                               (struct in6_addr *)&saddr->a6);
+                dst_release(&rt->u.dst);
+                return 0;
+        }
+        return -EHOSTUNREACH;
+}
+
 static struct dst_entry *
 __xfrm6_find_bundle(struct flowi *fl, struct xfrm_policy *policy)
 {
@@ -362,6 +382,7 @@ static struct xfrm_policy_afinfo xfrm6_policy_afinfo = {
         .family =               AF_INET6,
         .dst_ops =              &xfrm6_dst_ops,
         .dst_lookup =           xfrm6_dst_lookup,
+        .get_saddr =            xfrm6_get_saddr,
         .find_bundle =          __xfrm6_find_bundle,
         .bundle_create =        __xfrm6_bundle_create,
         .decode_session =       _decode_session6,
diff --git a/net/ipv6/xfrm6_state.c b/net/ipv6/xfrm6_state.c
index d88cd92c864e..711bfafb2472 100644
--- a/net/ipv6/xfrm6_state.c
+++ b/net/ipv6/xfrm6_state.c
@@ -42,22 +42,6 @@ __xfrm6_init_tempsel(struct xfrm_state *x, struct flowi *fl,
         memcpy(&x->props.saddr, &tmpl->saddr, sizeof(x->props.saddr));
         if (ipv6_addr_any((struct in6_addr*)&x->props.saddr))
                 memcpy(&x->props.saddr, saddr, sizeof(x->props.saddr));
-        if (tmpl->mode == XFRM_MODE_TUNNEL && ipv6_addr_any((struct in6_addr*)&x->props.saddr)) {
-                struct rt6_info *rt;
-                struct flowi fl_tunnel = {
-                        .nl_u = {
-                                .ip6_u = {
-                                        .daddr = *(struct in6_addr *)daddr,
-                                }
-                        }
-                };
-                if (!xfrm_dst_lookup((struct xfrm_dst **)&rt,
-                                     &fl_tunnel, AF_INET6)) {
-                        ipv6_get_saddr(&rt->u.dst, (struct in6_addr *)daddr,
-                                       (struct in6_addr *)&x->props.saddr);
-                        dst_release(&rt->u.dst);
-                }
-        }
         x->props.mode = tmpl->mode;
         x->props.reqid = tmpl->reqid;
         x->props.family = AF_INET6;
diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c
index 537854fe47ca..b6e2e79d7261 100644
--- a/net/xfrm/xfrm_policy.c
+++ b/net/xfrm/xfrm_policy.c
@@ -1107,6 +1107,20 @@ int __xfrm_sk_clone_policy(struct sock *sk)
         return 0;
 }
 
+static int
+xfrm_get_saddr(xfrm_address_t *local, xfrm_address_t *remote,
+               unsigned short family)
+{
+        int err;
+        struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
+
+        if (unlikely(afinfo == NULL))
+                return -EINVAL;
+        err = afinfo->get_saddr(local, remote);
+        xfrm_policy_put_afinfo(afinfo);
+        return err;
+}
+
 /* Resolve list of templates for the flow, given policy. */
 
 static int
@@ -1118,6 +1132,7 @@ xfrm_tmpl_resolve_one(struct xfrm_policy *policy, struct flowi *fl,
         int i, error;
         xfrm_address_t *daddr = xfrm_flowi_daddr(fl, family);
         xfrm_address_t *saddr = xfrm_flowi_saddr(fl, family);
+        xfrm_address_t tmp;
 
         for (nx=0, i = 0; i < policy->xfrm_nr; i++) {
                 struct xfrm_state *x;
@@ -1128,6 +1143,12 @@ xfrm_tmpl_resolve_one(struct xfrm_policy *policy, struct flowi *fl,
                 if (tmpl->mode == XFRM_MODE_TUNNEL) {
                         remote = &tmpl->id.daddr;
                         local = &tmpl->saddr;
+                        if (xfrm_addr_any(local, family)) {
+                                error = xfrm_get_saddr(&tmp, remote, family);
+                                if (error)
+                                        goto fail;
+                                local = &tmp;
+                        }
                 }
 
                 x = xfrm_state_find(remote, local, fl, tmpl, policy, &error, family);