1 files changed, 101 insertions, 135 deletions

diff --git a/net/dccp/ccid.c b/net/dccp/ccid.c
index 4809753d12a..597557254dd 100644
--- a/net/dccp/ccid.c
+++ b/net/dccp/ccid.c
@@ -11,87 +11,101 @@
  *	published by the Free Software Foundation.
  */
 
+#include <linux/slab.h>
+
 #include "ccid.h"
+#include "ccids/lib/tfrc.h"
 
-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);
+static struct ccid_operations *ccids[] = {
+	&ccid2_ops,
+#ifdef CONFIG_IP_DCCP_CCID3
+	&ccid3_ops,
+#endif
+};
 
-/*
- * The strategy is: modifications ccids vector are short, do not sleep and
- * veeery rare, but read access should be free of any exclusive locks.
- */
-static void ccids_write_lock(void)
+static struct ccid_operations *ccid_by_number(const u8 id)
 {
-	spin_lock(&ccids_lock);
-	while (atomic_read(&ccids_lockct) != 0) {
-		spin_unlock(&ccids_lock);
-		yield();
-		spin_lock(&ccids_lock);
-	}
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(ccids); i++)
+		if (ccids[i]->ccid_id == id)
+			return ccids[i];
+	return NULL;
 }
 
-static inline void ccids_write_unlock(void)
+/* check that up to @array_len members in @ccid_array are supported */
+bool ccid_support_check(u8 const *ccid_array, u8 array_len)
 {
-	spin_unlock(&ccids_lock);
+	while (array_len > 0)
+		if (ccid_by_number(ccid_array[--array_len]) == NULL)
+			return false;
+	return true;
 }
 
-static inline void ccids_read_lock(void)
+/**
+ * ccid_get_builtin_ccids  -  Populate a list of built-in CCIDs
+ * @ccid_array: pointer to copy into
+ * @array_len: value to return length into
+ *
+ * This function allocates memory - caller must see that it is freed after use.
+ */
+int ccid_get_builtin_ccids(u8 **ccid_array, u8 *array_len)
 {
-	atomic_inc(&ccids_lockct);
-	smp_mb__after_atomic_inc();
-	spin_unlock_wait(&ccids_lock);
+	*ccid_array = kmalloc(ARRAY_SIZE(ccids), gfp_any());
+	if (*ccid_array == NULL)
+		return -ENOBUFS;
+
+	for (*array_len = 0; *array_len < ARRAY_SIZE(ccids); *array_len += 1)
+		(*ccid_array)[*array_len] = ccids[*array_len]->ccid_id;
+	return 0;
 }
 
-static inline void ccids_read_unlock(void)
+int ccid_getsockopt_builtin_ccids(struct sock *sk, int len,
+				  char __user *optval, int __user *optlen)
 {
-	atomic_dec(&ccids_lockct);
-}
+	u8 *ccid_array, array_len;
+	int err = 0;
 
-#else
-#define ccids_write_lock() do { } while(0)
-#define ccids_write_unlock() do { } while(0)
-#define ccids_read_lock() do { } while(0)
-#define ccids_read_unlock() do { } while(0)
-#endif
+	if (ccid_get_builtin_ccids(&ccid_array, &array_len))
+		return -ENOBUFS;
+
+	if (put_user(array_len, optlen))
+		err = -EFAULT;
+	else if (len > 0 && copy_to_user(optval, ccid_array,
+					 len > array_len ? array_len : len))
+		err = -EFAULT;
 
-static struct kmem_cache *ccid_kmem_cache_create(int obj_size, const char *fmt,...)
+	kfree(ccid_array);
+	return err;
+}
+
+static struct kmem_cache *ccid_kmem_cache_create(int obj_size, char *slab_name_fmt, const char *fmt,...)
 {
 	struct kmem_cache *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);
+	vsnprintf(slab_name_fmt, CCID_SLAB_NAME_LENGTH, 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 = kmem_cache_create(slab_name_fmt, sizeof(struct ccid) + obj_size, 0,
 				 SLAB_HWCACHE_ALIGN, NULL);
-	if (slab == NULL)
-		kfree(slab_name);
 	return slab;
 }
 
 static void ccid_kmem_cache_destroy(struct kmem_cache *slab)
 {
-	if (slab != NULL) {
-		const char *name = kmem_cache_name(slab);
-
+	if (slab != NULL)
 		kmem_cache_destroy(slab);
-		kfree(name);
-	}
 }
 
-int ccid_register(struct ccid_operations *ccid_ops)
+static int ccid_activate(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,
+					       ccid_ops->ccid_hc_rx_slab_name,
 					       "ccid%u_hc_rx_sock",
 					       ccid_ops->ccid_id);
 	if (ccid_ops->ccid_hc_rx_slab == NULL)
@@ -99,84 +113,46 @@ int ccid_register(struct ccid_operations *ccid_ops)
 
 	ccid_ops->ccid_hc_tx_slab =
 			ccid_kmem_cache_create(ccid_ops->ccid_hc_tx_obj_size,
+					       ccid_ops->ccid_hc_tx_slab_name,
 					       "ccid%u_hc_tx_sock",
 					       ccid_ops->ccid_id);
 	if (ccid_ops->ccid_hc_tx_slab == NULL)
 		goto out_free_rx_slab;
 
-	ccids_write_lock();
-	err = -EEXIST;
-	if (ccids[ccid_ops->ccid_id] == NULL) {
-		ccids[ccid_ops->ccid_id] = ccid_ops;
-		err = 0;
-	}
-	ccids_write_unlock();
-	if (err != 0)
-		goto out_free_tx_slab;
-
-	pr_info("CCID: Registered CCID %d (%s)\n",
+	pr_info("DCCP: Activated CCID %d (%s)\n",
 		ccid_ops->ccid_id, ccid_ops->ccid_name);
+	err = 0;
 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_operations *ccid_ops)
+static void ccid_deactivate(struct ccid_operations *ccid_ops)
 {
-	ccids_write_lock();
-	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",
+	pr_info("DCCP: Deactivated CCID %d (%s)\n",
 		ccid_ops->ccid_id, ccid_ops->ccid_name);
-	return 0;
 }
 
-EXPORT_SYMBOL_GPL(ccid_unregister);
-
-struct ccid *ccid_new(unsigned char id, struct sock *sk, int rx, gfp_t gfp)
+struct ccid *ccid_new(const u8 id, struct sock *sk, bool rx)
 {
-	struct ccid_operations *ccid_ops;
+	struct ccid_operations *ccid_ops = ccid_by_number(id);
 	struct ccid *ccid = NULL;
 
-	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;
-
-	if (!try_module_get(ccid_ops->ccid_owner))
-		goto out_unlock;
-
-	ccids_read_unlock();
+		goto out;
 
 	ccid = kmem_cache_alloc(rx ? ccid_ops->ccid_hc_rx_slab :
-				     ccid_ops->ccid_hc_tx_slab, gfp);
+				     ccid_ops->ccid_hc_tx_slab, gfp_any());
 	if (ccid == NULL)
-		goto out_module_put;
+		goto out;
 	ccid->ccid_ops = ccid_ops;
 	if (rx) {
 		memset(ccid + 1, 0, ccid_ops->ccid_hc_rx_obj_size);
@@ -191,67 +167,57 @@ struct ccid *ccid_new(unsigned char id, struct sock *sk, int rx, gfp_t gfp)
 	}
 out:
 	return ccid;
-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_new);
-
-struct ccid *ccid_hc_rx_new(unsigned char id, struct sock *sk, gfp_t gfp)
+void ccid_hc_rx_delete(struct ccid *ccid, struct sock *sk)
 {
-	return ccid_new(id, sk, 1, gfp);
+	if (ccid != NULL) {
+		if (ccid->ccid_ops->ccid_hc_rx_exit != NULL)
+			ccid->ccid_ops->ccid_hc_rx_exit(sk);
+		kmem_cache_free(ccid->ccid_ops->ccid_hc_rx_slab, ccid);
+	}
 }
 
-EXPORT_SYMBOL_GPL(ccid_hc_rx_new);
-
-struct ccid *ccid_hc_tx_new(unsigned char id,struct sock *sk,  gfp_t gfp)
+void ccid_hc_tx_delete(struct ccid *ccid, struct sock *sk)
 {
-	return ccid_new(id, sk, 0, gfp);
+	if (ccid != NULL) {
+		if (ccid->ccid_ops->ccid_hc_tx_exit != NULL)
+			ccid->ccid_ops->ccid_hc_tx_exit(sk);
+		kmem_cache_free(ccid->ccid_ops->ccid_hc_tx_slab, ccid);
+	}
 }
 
-EXPORT_SYMBOL_GPL(ccid_hc_tx_new);
-
-static void ccid_delete(struct ccid *ccid, struct sock *sk, int rx)
+int __init ccid_initialize_builtins(void)
 {
-	struct ccid_operations *ccid_ops;
+	int i, err = tfrc_lib_init();
 
-	if (ccid == NULL)
-		return;
+	if (err)
+		return err;
 
-	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);
+	for (i = 0; i < ARRAY_SIZE(ccids); i++) {
+		err = ccid_activate(ccids[i]);
+		if (err)
+			goto unwind_registrations;
 	}
-	ccids_read_lock();
-	if (ccids[ccid_ops->ccid_id] != NULL)
-		module_put(ccid_ops->ccid_owner);
-	ccids_read_unlock();
-}
+	return 0;
 
-void ccid_hc_rx_delete(struct ccid *ccid, struct sock *sk)
-{
-	ccid_delete(ccid, sk, 1);
+unwind_registrations:
+	while(--i >= 0)
+		ccid_deactivate(ccids[i]);
+	tfrc_lib_exit();
+	return err;
 }
 
-EXPORT_SYMBOL_GPL(ccid_hc_rx_delete);
-
-void ccid_hc_tx_delete(struct ccid *ccid, struct sock *sk)
+void ccid_cleanup_builtins(void)
 {
-	ccid_delete(ccid, sk, 0);
-}
+	int i;
 
-EXPORT_SYMBOL_GPL(ccid_hc_tx_delete);
+	for (i = 0; i < ARRAY_SIZE(ccids); i++)
+		ccid_deactivate(ccids[i]);
+	tfrc_lib_exit();
+}