1 files changed, 96 insertions, 158 deletions

diff --git a/net/dccp/ccid.c b/net/dccp/ccid.c
index bcc643f992ae..f3e9ba1cfd01 100644
--- a/net/dccp/ccid.c
+++ b/net/dccp/ccid.c
@@ -12,56 +12,70 @@
  */
 
 #include "ccid.h"
+#include "ccids/lib/tfrc.h"
 
-static u8 builtin_ccids[] = {
-        DCCPC_CCID2,            /* CCID2 is supported by default */
-#if defined(CONFIG_IP_DCCP_CCID3) || defined(CONFIG_IP_DCCP_CCID3_MODULE)
-        DCCPC_CCID3,
+static struct ccid_operations *ccids[] = {
+        &ccid2_ops,
+#ifdef CONFIG_IP_DCCP_CCID3
+        &ccid3_ops,
 #endif
 };
 
-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);
-
-/*
- * 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 (len < ARRAY_SIZE(ccids))
+                return -EINVAL;
+
+        if (ccid_get_builtin_ccids(&ccid_array, &array_len))
+                return -ENOBUFS;
+
+        if (put_user(array_len, optlen) ||
+            copy_to_user(optval, ccid_array, array_len))
+                err = -EFAULT;
+
+        kfree(ccid_array);
+        return err;
+}
 
 static struct kmem_cache *ccid_kmem_cache_create(int obj_size, const char *fmt,...)
 {
@@ -93,48 +107,7 @@ static void ccid_kmem_cache_destroy(struct kmem_cache *slab)
         }
 }
 
-/* check that up to @array_len members in @ccid_array are supported */
-bool ccid_support_check(u8 const *ccid_array, u8 array_len)
-{
-        u8 i, j, found;
-
-        for (i = 0, found = 0; i < array_len; i++, found = 0) {
-                for (j = 0; !found && j < ARRAY_SIZE(builtin_ccids); j++)
-                        found = (ccid_array[i] == builtin_ccids[j]);
-                if (!found)
-                        return false;
-        }
-        return true;
-}
-
-/**
- * ccid_get_builtin_ccids  -  Provide copy of `builtin' CCID array
- * @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)
-{
-        *ccid_array = kmemdup(builtin_ccids, sizeof(builtin_ccids), gfp_any());
-        if (*ccid_array == NULL)
-                return -ENOBUFS;
-        *array_len = ARRAY_SIZE(builtin_ccids);
-        return 0;
-}
-
-int ccid_getsockopt_builtin_ccids(struct sock *sk, int len,
-                                    char __user *optval, int __user *optlen)
-{
-        if (len < sizeof(builtin_ccids))
-                return -EINVAL;
-
-        if (put_user(sizeof(builtin_ccids), optlen) ||
-            copy_to_user(optval, builtin_ccids, sizeof(builtin_ccids)))
-                return -EFAULT;
-        return 0;
-}
-
-int ccid_register(struct ccid_operations *ccid_ops)
+static int ccid_activate(struct ccid_operations *ccid_ops)
 {
         int err = -ENOBUFS;
 
@@ -152,79 +125,40 @@ int ccid_register(struct ccid_operations *ccid_ops)
         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("CCID: 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("CCID: 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_MODULES
-        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);
@@ -239,53 +173,57 @@ 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);
-
-static void ccid_delete(struct ccid *ccid, struct sock *sk, int rx)
+void ccid_hc_rx_delete(struct ccid *ccid, struct sock *sk)
 {
-        struct ccid_operations *ccid_ops;
-
-        if (ccid == NULL)
-                return;
-
-        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);
+        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);
         }
-        ccids_read_lock();
-        if (ccids[ccid_ops->ccid_id] != NULL)
-                module_put(ccid_ops->ccid_owner);
-        ccids_read_unlock();
 }
 
-void ccid_hc_rx_delete(struct ccid *ccid, struct sock *sk)
+void ccid_hc_tx_delete(struct ccid *ccid, struct sock *sk)
 {
-        ccid_delete(ccid, sk, 1);
+        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_rx_delete);
-
-void ccid_hc_tx_delete(struct ccid *ccid, struct sock *sk)
+int __init ccid_initialize_builtins(void)
 {
-        ccid_delete(ccid, sk, 0);
+        int i, err = tfrc_lib_init();
+
+        if (err)
+                return err;
+
+        for (i = 0; i < ARRAY_SIZE(ccids); i++) {
+                err = ccid_activate(ccids[i]);
+                if (err)
+                        goto unwind_registrations;
+        }
+        return 0;
+
+unwind_registrations:
+        while(--i >= 0)
+                ccid_deactivate(ccids[i]);
+        tfrc_lib_exit();
+        return err;
 }
 
-EXPORT_SYMBOL_GPL(ccid_hc_tx_delete);
+void ccid_cleanup_builtins(void)
+{
+        int i;
+
+        for (i = 0; i < ARRAY_SIZE(ccids); i++)
+                ccid_deactivate(ccids[i]);
+        tfrc_lib_exit();
+}