[IPSEC]: Add xfrm_state_afinfo->init_flags

This patch adds the xfrm_state_afinfo->init_flags hook which allows
each address family to perform any common initialisation that does
not require a corresponding destructor call.

It will be used subsequently to set the XFRM_STATE_NOPMTUDISC flag
in IPv4.

It also fixes up the error codes returned by xfrm_init_state.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Acked-by: James Morris <jmorris@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 19 insertions, 2 deletions

diff --git a/include/net/xfrm.h b/include/net/xfrm.h
index 77bfdde440f8..029522a4ceda 100644
--- a/include/net/xfrm.h
+++ b/include/net/xfrm.h
@@ -204,6 +204,7 @@ struct xfrm_state_afinfo {
         rwlock_t                lock;
         struct list_head        *state_bydst;
         struct list_head        *state_byspi;
+        int                     (*init_flags)(struct xfrm_state *x);
         void                    (*init_tempsel)(struct xfrm_state *x, struct flowi *fl,
                                                 struct xfrm_tmpl *tmpl,
                                                 xfrm_address_t *daddr, xfrm_address_t *saddr);
diff --git a/net/xfrm/xfrm_state.c b/net/xfrm/xfrm_state.c
index 1845b73d69f9..9d206c282cf1 100644
--- a/net/xfrm/xfrm_state.c
+++ b/net/xfrm/xfrm_state.c
@@ -1058,10 +1058,26 @@ EXPORT_SYMBOL(xfrm_state_mtu);
 
 int xfrm_init_state(struct xfrm_state *x)
 {
+        struct xfrm_state_afinfo *afinfo;
+        int family = x->props.family;
         int err;
 
-        err = -ENOENT;
-        x->type = xfrm_get_type(x->id.proto, x->props.family);
+        err = -EAFNOSUPPORT;
+        afinfo = xfrm_state_get_afinfo(family);
+        if (!afinfo)
+                goto error;
+
+        err = 0;
+        if (afinfo->init_flags)
+                err = afinfo->init_flags(x);
+
+        xfrm_state_put_afinfo(afinfo);
+
+        if (err)
+                goto error;
+
+        err = -EPROTONOSUPPORT;
+        x->type = xfrm_get_type(x->id.proto, family);
         if (x->type == NULL)
                 goto error;