[IPSEC]: Store afinfo pointer in xfrm_mode

It is convenient to have a pointer from xfrm_state to address-specific
functions such as the output function for a family.  Currently the
address-specific policy code calls out to the xfrm state code to get
those pointers when we could get it in an easier way via the state
itself.

This patch adds an xfrm_state_afinfo to xfrm_mode (since they're
address-specific) and changes the policy code to use it.  I've also
added an owner field to do reference counting on the module providing
the afinfo even though it isn't strictly necessary today since IPv6
can't be unloaded yet.

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

diff --git a/include/net/xfrm.h b/include/net/xfrm.h
index 2143f2911a21ac29cc33a382aedfa582c539e31c..f0f3318f6550e45f55c9b8f77f7d5f4999901ad3 100644 (file)
--- a/include/net/xfrm.h
+++ b/include/net/xfrm.h
@@ -253,7 +253,8 @@ extern void km_state_expired(struct xfrm_state *x, int hard, u32 pid);
 extern int __xfrm_state_delete(struct xfrm_state *x);
 
 struct xfrm_state_afinfo {
-       unsigned short          family;
+       unsigned int            family;
+       struct module           *owner;
        struct xfrm_type        *type_map[IPPROTO_MAX];
        struct xfrm_mode        *mode_map[XFRM_MODE_MAX];
        int                     (*init_flags)(struct xfrm_state *x);
@@ -267,8 +268,6 @@ struct xfrm_state_afinfo {
 
 extern int xfrm_state_register_afinfo(struct xfrm_state_afinfo *afinfo);
 extern int xfrm_state_unregister_afinfo(struct xfrm_state_afinfo *afinfo);
-extern struct xfrm_state_afinfo *xfrm_state_get_afinfo(unsigned short family);
-extern void xfrm_state_put_afinfo(struct xfrm_state_afinfo *afinfo);
 
 extern void xfrm_state_delete_tunnel(struct xfrm_state *x);
 
@@ -312,6 +311,7 @@ struct xfrm_mode {
         */
        int (*output)(struct xfrm_state *x,struct sk_buff *skb);
 
+       struct xfrm_state_afinfo *afinfo;
        struct module *owner;
        unsigned int encap;
        int flags;

diff --git a/net/ipv4/xfrm4_policy.c b/net/ipv4/xfrm4_policy.c
index 2373d673df60b799a32a20713e00b0c2f2e83905..c65b8e03c0490d83a1aa5862f116c4a9436bd463 100644 (file)
--- a/net/ipv4/xfrm4_policy.c
+++ b/net/ipv4/xfrm4_policy.c
@@ -151,7 +151,6 @@ __xfrm4_bundle_create(struct xfrm_policy *policy, struct xfrm_state **xfrm, int
        i = 0;
        for (; dst_prev != &rt->u.dst; dst_prev = dst_prev->child) {
                struct xfrm_dst *x = (struct xfrm_dst*)dst_prev;
-               struct xfrm_state_afinfo *afinfo;
                x->u.rt.fl = *fl;
 
                dst_prev->xfrm = xfrm[i++];
@@ -169,17 +168,7 @@ __xfrm4_bundle_create(struct xfrm_policy *policy, struct xfrm_state **xfrm, int
                /* Copy neighbout for reachability confirmation */
                dst_prev->neighbour     = neigh_clone(rt->u.dst.neighbour);
                dst_prev->input         = rt->u.dst.input;
-               /* XXX: When IPv6 module can be unloaded, we should manage reference
-                * to xfrm6_output in afinfo->output. Miyazawa
-                * */
-               afinfo = xfrm_state_get_afinfo(dst_prev->xfrm->props.family);
-               if (!afinfo) {
-                       dst = *dst_p;
-                       err = -EAFNOSUPPORT;
-                       goto error;
-               }
-               dst_prev->output = afinfo->output;
-               xfrm_state_put_afinfo(afinfo);
+               dst_prev->output = dst_prev->xfrm->mode->afinfo->output;
                if (dst_prev->xfrm->props.family == AF_INET && rt->peer)
                        atomic_inc(&rt->peer->refcnt);
                x->u.rt.peer = rt->peer;

diff --git a/net/ipv4/xfrm4_state.c b/net/ipv4/xfrm4_state.c
index 93e2c061cddaf3b71a7c6e3c0bae0a22f1b45d76..13d54a1c3337bd311c7245f331367296f07b0558 100644 (file)
--- a/net/ipv4/xfrm4_state.c
+++ b/net/ipv4/xfrm4_state.c
@@ -49,6 +49,7 @@ __xfrm4_init_tempsel(struct xfrm_state *x, struct flowi *fl,
 
 static struct xfrm_state_afinfo xfrm4_state_afinfo = {
        .family                 = AF_INET,
+       .owner                  = THIS_MODULE,
        .init_flags             = xfrm4_init_flags,
        .init_tempsel           = __xfrm4_init_tempsel,
        .output                 = xfrm4_output,

diff --git a/net/ipv6/xfrm6_policy.c b/net/ipv6/xfrm6_policy.c
index dc4bdcb55cbe9a79171c2433f31227316a8b3c62..324268329f698d80e0f8110e720ad13b6a08d226 100644 (file)
--- a/net/ipv6/xfrm6_policy.c
+++ b/net/ipv6/xfrm6_policy.c
@@ -214,7 +214,6 @@ __xfrm6_bundle_create(struct xfrm_policy *policy, struct xfrm_state **xfrm, int
        i = 0;
        for (; dst_prev != &rt->u.dst; dst_prev = dst_prev->child) {
                struct xfrm_dst *x = (struct xfrm_dst*)dst_prev;
-               struct xfrm_state_afinfo *afinfo;
 
                dst_prev->xfrm = xfrm[i++];
                dst_prev->dev = rt->u.dst.dev;
@@ -231,18 +230,7 @@ __xfrm6_bundle_create(struct xfrm_policy *policy, struct xfrm_state **xfrm, int
                /* Copy neighbour for reachability confirmation */
                dst_prev->neighbour     = neigh_clone(rt->u.dst.neighbour);
                dst_prev->input         = rt->u.dst.input;
-               /* XXX: When IPv4 is implemented as module and can be unloaded,
-                * we should manage reference to xfrm4_output in afinfo->output.
-                * Miyazawa
-                */
-               afinfo = xfrm_state_get_afinfo(dst_prev->xfrm->props.family);
-               if (!afinfo) {
-                       dst = *dst_p;
-                       goto error;
-               }
-
-               dst_prev->output = afinfo->output;
-               xfrm_state_put_afinfo(afinfo);
+               dst_prev->output = dst_prev->xfrm->mode->afinfo->output;
                /* Sheit... I remember I did this right. Apparently,
                 * it was magically lost, so this code needs audit */
                x->u.rt6.rt6i_flags    = rt0->rt6i_flags&(RTCF_BROADCAST|RTCF_MULTICAST|RTCF_LOCAL);

diff --git a/net/ipv6/xfrm6_state.c b/net/ipv6/xfrm6_state.c
index e644c80515fc591d2c016b5ca796a736bf9567d1..b392bee396f16341c2842aa20c3759c19afb0238 100644 (file)
--- a/net/ipv6/xfrm6_state.c
+++ b/net/ipv6/xfrm6_state.c
@@ -170,6 +170,7 @@ __xfrm6_tmpl_sort(struct xfrm_tmpl **dst, struct xfrm_tmpl **src, int n)
 
 static struct xfrm_state_afinfo xfrm6_state_afinfo = {
        .family                 = AF_INET6,
+       .owner                  = THIS_MODULE,
        .init_tempsel           = __xfrm6_init_tempsel,
        .tmpl_sort              = __xfrm6_tmpl_sort,
        .state_sort             = __xfrm6_state_sort,

diff --git a/net/xfrm/xfrm_state.c b/net/xfrm/xfrm_state.c
index dc438f2b944226a26ec45033d5ff73cffe8dc433..48b4a06b3d1a2e15138231055e0e92817440ea8c 100644 (file)
--- a/net/xfrm/xfrm_state.c
+++ b/net/xfrm/xfrm_state.c
@@ -57,6 +57,9 @@ static unsigned int xfrm_state_hashmax __read_mostly = 1 * 1024 * 1024;
 static unsigned int xfrm_state_num;
 static unsigned int xfrm_state_genid;
 
+static struct xfrm_state_afinfo *xfrm_state_get_afinfo(unsigned int family);
+static void xfrm_state_put_afinfo(struct xfrm_state_afinfo *afinfo);
+
 static inline unsigned int xfrm_dst_hash(xfrm_address_t *daddr,
                                         xfrm_address_t *saddr,
                                         u32 reqid,
@@ -289,11 +292,18 @@ int xfrm_register_mode(struct xfrm_mode *mode, int family)
 
        err = -EEXIST;
        modemap = afinfo->mode_map;
-       if (likely(modemap[mode->encap] == NULL)) {
-               modemap[mode->encap] = mode;
-               err = 0;
-       }
+       if (modemap[mode->encap])
+               goto out;
 
+       err = -ENOENT;
+       if (!try_module_get(afinfo->owner))
+               goto out;
+
+       mode->afinfo = afinfo;
+       modemap[mode->encap] = mode;
+       err = 0;
+
+out:
        xfrm_state_unlock_afinfo(afinfo);
        return err;
 }
@@ -316,6 +326,7 @@ int xfrm_unregister_mode(struct xfrm_mode *mode, int family)
        modemap = afinfo->mode_map;
        if (likely(modemap[mode->encap] == mode)) {
                modemap[mode->encap] = NULL;
+               module_put(mode->afinfo->owner);
                err = 0;
        }
 
@@ -1869,7 +1880,7 @@ int xfrm_state_unregister_afinfo(struct xfrm_state_afinfo *afinfo)
 }
 EXPORT_SYMBOL(xfrm_state_unregister_afinfo);
 
-struct xfrm_state_afinfo *xfrm_state_get_afinfo(unsigned short family)
+static struct xfrm_state_afinfo *xfrm_state_get_afinfo(unsigned int family)
 {
        struct xfrm_state_afinfo *afinfo;
        if (unlikely(family >= NPROTO))
@@ -1881,14 +1892,11 @@ struct xfrm_state_afinfo *xfrm_state_get_afinfo(unsigned short family)
        return afinfo;
 }
 
-void xfrm_state_put_afinfo(struct xfrm_state_afinfo *afinfo)
+static void xfrm_state_put_afinfo(struct xfrm_state_afinfo *afinfo)
 {
        read_unlock(&xfrm_state_afinfo_lock);
 }
 
-EXPORT_SYMBOL(xfrm_state_get_afinfo);
-EXPORT_SYMBOL(xfrm_state_put_afinfo);
-
 /* Temporarily located here until net/xfrm/xfrm_tunnel.c is created */
 void xfrm_state_delete_tunnel(struct xfrm_state *x)
 {