1 files changed, 77 insertions, 24 deletions

diff --git a/net/dccp/ccid.c b/net/dccp/ccid.c
index 4809753d12ae..e3fb52b4f5c6 100644
--- a/net/dccp/ccid.c
+++ b/net/dccp/ccid.c
@@ -13,6 +13,13 @@
 
 #include "ccid.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,
+#endif
+};
+
 static struct ccid_operations *ccids[CCID_MAX];
 #if defined(CONFIG_SMP) || defined(CONFIG_PREEMPT)
 static atomic_t ccids_lockct = ATOMIC_INIT(0);
@@ -86,6 +93,47 @@ 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)
 {
         int err = -ENOBUFS;
@@ -148,22 +196,41 @@ int ccid_unregister(struct ccid_operations *ccid_ops)
 
 EXPORT_SYMBOL_GPL(ccid_unregister);
 
+/**
+ * ccid_request_module  -  Pre-load CCID module for later use
+ * This should be called only from process context (e.g. during connection
+ * setup) and is necessary for later calls to ccid_new (typically in software
+ * interrupt), so that it has the modules available when they are needed.
+ */
+static int ccid_request_module(u8 id)
+{
+        if (!in_atomic()) {
+                ccids_read_lock();
+                if (ccids[id] == NULL) {
+                        ccids_read_unlock();
+                        return request_module("net-dccp-ccid-%d", id);
+                }
+                ccids_read_unlock();
+        }
+        return 0;
+}
+
+int ccid_request_modules(u8 const *ccid_array, u8 array_len)
+{
+#ifdef CONFIG_KMOD
+        while (array_len--)
+                if (ccid_request_module(ccid_array[array_len]))
+                        return -1;
+#endif
+        return 0;
+}
+
 struct ccid *ccid_new(unsigned char id, struct sock *sk, int rx, gfp_t gfp)
 {
         struct ccid_operations *ccid_ops;
         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;
@@ -205,20 +272,6 @@ out_module_put:
 
 EXPORT_SYMBOL_GPL(ccid_new);
 
-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;