[IPSEC] xfrm: Abstract out encapsulation modes
This patch adds the structure xfrm_mode. It is meant to represent
the operations carried out by transport/tunnel modes.
By doing this we allow additional encapsulation modes to be added
without clogging up the xfrm_input/xfrm_output paths.
Candidate modes include 4-to-6 tunnel mode, 6-to-4 tunnel mode, and
BEET modes.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c
index 44b64a5..b893692 100644
--- a/net/xfrm/xfrm_policy.c
+++ b/net/xfrm/xfrm_policy.c
@@ -138,6 +138,89 @@
module_put(type->owner);
}
+int xfrm_register_mode(struct xfrm_mode *mode, int family)
+{
+ struct xfrm_policy_afinfo *afinfo;
+ struct xfrm_mode **modemap;
+ int err;
+
+ if (unlikely(mode->encap >= XFRM_MODE_MAX))
+ return -EINVAL;
+
+ afinfo = xfrm_policy_lock_afinfo(family);
+ if (unlikely(afinfo == NULL))
+ return -EAFNOSUPPORT;
+
+ err = -EEXIST;
+ modemap = afinfo->mode_map;
+ if (likely(modemap[mode->encap] == NULL)) {
+ modemap[mode->encap] = mode;
+ err = 0;
+ }
+
+ xfrm_policy_unlock_afinfo(afinfo);
+ return err;
+}
+EXPORT_SYMBOL(xfrm_register_mode);
+
+int xfrm_unregister_mode(struct xfrm_mode *mode, int family)
+{
+ struct xfrm_policy_afinfo *afinfo;
+ struct xfrm_mode **modemap;
+ int err;
+
+ if (unlikely(mode->encap >= XFRM_MODE_MAX))
+ return -EINVAL;
+
+ afinfo = xfrm_policy_lock_afinfo(family);
+ if (unlikely(afinfo == NULL))
+ return -EAFNOSUPPORT;
+
+ err = -ENOENT;
+ modemap = afinfo->mode_map;
+ if (likely(modemap[mode->encap] == mode)) {
+ modemap[mode->encap] = NULL;
+ err = 0;
+ }
+
+ xfrm_policy_unlock_afinfo(afinfo);
+ return err;
+}
+EXPORT_SYMBOL(xfrm_unregister_mode);
+
+struct xfrm_mode *xfrm_get_mode(unsigned int encap, int family)
+{
+ struct xfrm_policy_afinfo *afinfo;
+ struct xfrm_mode *mode;
+ int modload_attempted = 0;
+
+ if (unlikely(encap >= XFRM_MODE_MAX))
+ return NULL;
+
+retry:
+ afinfo = xfrm_policy_get_afinfo(family);
+ if (unlikely(afinfo == NULL))
+ return NULL;
+
+ mode = afinfo->mode_map[encap];
+ if (unlikely(mode && !try_module_get(mode->owner)))
+ mode = NULL;
+ if (!mode && !modload_attempted) {
+ xfrm_policy_put_afinfo(afinfo);
+ request_module("xfrm-mode-%d-%d", family, encap);
+ modload_attempted = 1;
+ goto retry;
+ }
+
+ xfrm_policy_put_afinfo(afinfo);
+ return mode;
+}
+
+void xfrm_put_mode(struct xfrm_mode *mode)
+{
+ module_put(mode->owner);
+}
+
static inline unsigned long make_jiffies(long secs)
{
if (secs >= (MAX_SCHEDULE_TIMEOUT-1)/HZ)