[DCCP] CCID: Improve CCID infrastructure
1. No need for ->ccid_init nor ->ccid_exit, this is what module_{init,exit}
does and anynways neither ccid2 nor ccid3 were using it.
2. Rename struct ccid to struct ccid_operations and introduce struct ccid
with a pointer to ccid_operations and rigth after it the rx or tx
private state.
3. Remove the pointer to the state of the half connections from struct
dccp_sock, now its derived thru ccid_priv() from the ccid pointer.
Now we also can implement the setsockopt for changing the CCID easily as
no ccid init routines can affect struct dccp_sock in any way that prevents
other CCIDs from working if a CCID switch operation is asked by apps.
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/dccp/ccid.c b/net/dccp/ccid.c
index 06b191a..ff05e59 100644
--- a/net/dccp/ccid.c
+++ b/net/dccp/ccid.c
@@ -13,7 +13,7 @@
#include "ccid.h"
-static struct ccid *ccids[CCID_MAX];
+static struct ccid_operations *ccids[CCID_MAX];
#if defined(CONFIG_SMP) || defined(CONFIG_PREEMPT)
static atomic_t ccids_lockct = ATOMIC_INIT(0);
static DEFINE_SPINLOCK(ccids_lock);
@@ -55,82 +55,202 @@
#define ccids_read_unlock() do { } while(0)
#endif
-int ccid_register(struct ccid *ccid)
+static kmem_cache_t *ccid_kmem_cache_create(int obj_size, const char *fmt,...)
{
- int err;
+ kmem_cache_t *slab;
+ char slab_name_fmt[32], *slab_name;
+ va_list args;
+
+ va_start(args, fmt);
+ vsnprintf(slab_name_fmt, sizeof(slab_name_fmt), fmt, args);
+ va_end(args);
+
+ slab_name = kstrdup(slab_name_fmt, GFP_KERNEL);
+ if (slab_name == NULL)
+ return NULL;
+ slab = kmem_cache_create(slab_name, sizeof(struct ccid) + obj_size, 0,
+ SLAB_HWCACHE_ALIGN, NULL, NULL);
+ if (slab == NULL)
+ kfree(slab_name);
+ return slab;
+}
+
+static void ccid_kmem_cache_destroy(kmem_cache_t *slab)
+{
+ if (slab != NULL) {
+ const char *name = kmem_cache_name(slab);
+
+ kmem_cache_destroy(slab);
+ kfree(name);
+ }
+}
+
+int ccid_register(struct ccid_operations *ccid_ops)
+{
+ int err = -ENOBUFS;
+
+ ccid_ops->ccid_hc_rx_slab =
+ ccid_kmem_cache_create(ccid_ops->ccid_hc_rx_obj_size,
+ "%s_hc_rx_sock",
+ ccid_ops->ccid_name);
+ if (ccid_ops->ccid_hc_rx_slab == NULL)
+ goto out;
+
+ ccid_ops->ccid_hc_tx_slab =
+ ccid_kmem_cache_create(ccid_ops->ccid_hc_tx_obj_size,
+ "%s_hc_tx_sock",
+ ccid_ops->ccid_name);
+ if (ccid_ops->ccid_hc_tx_slab == NULL)
+ goto out_free_rx_slab;
ccids_write_lock();
err = -EEXIST;
- if (ccids[ccid->ccid_id] == NULL) {
- ccids[ccid->ccid_id] = ccid;
+ if (ccids[ccid_ops->ccid_id] == NULL) {
+ ccids[ccid_ops->ccid_id] = ccid_ops;
err = 0;
}
ccids_write_unlock();
- if (err == 0)
- pr_info("CCID: Registered CCID %d (%s)\n",
- ccid->ccid_id, ccid->ccid_name);
+ if (err != 0)
+ goto out_free_tx_slab;
+
+ pr_info("CCID: Registered CCID %d (%s)\n",
+ ccid_ops->ccid_id, ccid_ops->ccid_name);
+out:
return err;
+out_free_tx_slab:
+ ccid_kmem_cache_destroy(ccid_ops->ccid_hc_tx_slab);
+ ccid_ops->ccid_hc_tx_slab = NULL;
+ goto out;
+out_free_rx_slab:
+ ccid_kmem_cache_destroy(ccid_ops->ccid_hc_rx_slab);
+ ccid_ops->ccid_hc_rx_slab = NULL;
+ goto out;
}
EXPORT_SYMBOL_GPL(ccid_register);
-int ccid_unregister(struct ccid *ccid)
+int ccid_unregister(struct ccid_operations *ccid_ops)
{
ccids_write_lock();
- ccids[ccid->ccid_id] = NULL;
+ ccids[ccid_ops->ccid_id] = NULL;
ccids_write_unlock();
+
+ ccid_kmem_cache_destroy(ccid_ops->ccid_hc_tx_slab);
+ ccid_ops->ccid_hc_tx_slab = NULL;
+ ccid_kmem_cache_destroy(ccid_ops->ccid_hc_rx_slab);
+ ccid_ops->ccid_hc_rx_slab = NULL;
+
pr_info("CCID: Unregistered CCID %d (%s)\n",
- ccid->ccid_id, ccid->ccid_name);
+ ccid_ops->ccid_id, ccid_ops->ccid_name);
return 0;
}
EXPORT_SYMBOL_GPL(ccid_unregister);
-struct ccid *ccid_init(unsigned char id, struct sock *sk)
+struct ccid *ccid_new(unsigned char id, struct sock *sk, int rx, gfp_t gfp)
{
- struct ccid *ccid;
+ struct ccid_operations *ccid_ops;
+ struct ccid *ccid = NULL;
-#ifdef CONFIG_KMOD
- if (ccids[id] == NULL)
- request_module("net-dccp-ccid-%d", id);
-#endif
ccids_read_lock();
+#ifdef CONFIG_KMOD
+ if (ccids[id] == NULL) {
+ /* We only try to load if in process context */
+ ccids_read_unlock();
+ if (gfp & GFP_ATOMIC)
+ goto out;
+ request_module("net-dccp-ccid-%d", id);
+ ccids_read_lock();
+ }
+#endif
+ ccid_ops = ccids[id];
+ if (ccid_ops == NULL)
+ goto out_unlock;
- ccid = ccids[id];
- if (ccid == NULL)
- goto out;
+ if (!try_module_get(ccid_ops->ccid_owner))
+ goto out_unlock;
- if (!try_module_get(ccid->ccid_owner))
- goto out_err;
-
- if (ccid->ccid_init != NULL && ccid->ccid_init(sk) != 0)
- goto out_module_put;
-out:
ccids_read_unlock();
+
+ ccid = kmem_cache_alloc(rx ? ccid_ops->ccid_hc_rx_slab :
+ ccid_ops->ccid_hc_tx_slab, gfp);
+ if (ccid == NULL)
+ goto out_module_put;
+ ccid->ccid_ops = ccid_ops;
+ if (rx) {
+ memset(ccid + 1, 0, ccid_ops->ccid_hc_rx_obj_size);
+ if (ccid->ccid_ops->ccid_hc_rx_init != NULL &&
+ ccid->ccid_ops->ccid_hc_rx_init(ccid, sk) != 0)
+ goto out_free_ccid;
+ } else {
+ memset(ccid + 1, 0, ccid_ops->ccid_hc_tx_obj_size);
+ if (ccid->ccid_ops->ccid_hc_tx_init != NULL &&
+ ccid->ccid_ops->ccid_hc_tx_init(ccid, sk) != 0)
+ goto out_free_ccid;
+ }
+out:
return ccid;
-out_module_put:
- module_put(ccid->ccid_owner);
-out_err:
+out_unlock:
+ ccids_read_unlock();
+ goto out;
+out_free_ccid:
+ kmem_cache_free(rx ? ccid_ops->ccid_hc_rx_slab :
+ ccid_ops->ccid_hc_tx_slab, ccid);
ccid = NULL;
+out_module_put:
+ module_put(ccid_ops->ccid_owner);
goto out;
}
-EXPORT_SYMBOL_GPL(ccid_init);
+EXPORT_SYMBOL_GPL(ccid_new);
-void ccid_exit(struct ccid *ccid, struct sock *sk)
+struct ccid *ccid_hc_rx_new(unsigned char id, struct sock *sk, gfp_t gfp)
{
+ return ccid_new(id, sk, 1, gfp);
+}
+
+EXPORT_SYMBOL_GPL(ccid_hc_rx_new);
+
+struct ccid *ccid_hc_tx_new(unsigned char id,struct sock *sk, gfp_t gfp)
+{
+ return ccid_new(id, sk, 0, gfp);
+}
+
+EXPORT_SYMBOL_GPL(ccid_hc_tx_new);
+
+static void ccid_delete(struct ccid *ccid, struct sock *sk, int rx)
+{
+ struct ccid_operations *ccid_ops;
+
if (ccid == NULL)
return;
- ccids_read_lock();
-
- if (ccids[ccid->ccid_id] != NULL) {
- if (ccid->ccid_exit != NULL)
- ccid->ccid_exit(sk);
- module_put(ccid->ccid_owner);
+ ccid_ops = ccid->ccid_ops;
+ if (rx) {
+ if (ccid_ops->ccid_hc_rx_exit != NULL)
+ ccid_ops->ccid_hc_rx_exit(sk);
+ kmem_cache_free(ccid_ops->ccid_hc_rx_slab, ccid);
+ } else {
+ if (ccid_ops->ccid_hc_tx_exit != NULL)
+ ccid_ops->ccid_hc_tx_exit(sk);
+ kmem_cache_free(ccid_ops->ccid_hc_tx_slab, ccid);
}
-
+ ccids_read_lock();
+ if (ccids[ccid_ops->ccid_id] != NULL)
+ module_put(ccid_ops->ccid_owner);
ccids_read_unlock();
}
-EXPORT_SYMBOL_GPL(ccid_exit);
+void ccid_hc_rx_delete(struct ccid *ccid, struct sock *sk)
+{
+ ccid_delete(ccid, sk, 1);
+}
+
+EXPORT_SYMBOL_GPL(ccid_hc_rx_delete);
+
+void ccid_hc_tx_delete(struct ccid *ccid, struct sock *sk)
+{
+ ccid_delete(ccid, sk, 0);
+}
+
+EXPORT_SYMBOL_GPL(ccid_hc_tx_delete);