1 files changed, 54 insertions, 0 deletions

diff --git a/include/net/sock.h b/include/net/sock.h
index 01810a3f19df..f2046e404a61 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -52,6 +52,7 @@
 #include <linux/mm.h>
 #include <linux/security.h>
 #include <linux/slab.h>
+#include <linux/uaccess.h>
 
 #include <linux/filter.h>
 #include <linux/rculist_nulls.h>
@@ -1389,6 +1390,59 @@ static inline void sk_nocaps_add(struct sock *sk, int flags)
         sk->sk_route_caps &= ~flags;
 }
 
+static inline int skb_do_copy_data_nocache(struct sock *sk, struct sk_buff *skb,
+                                           char __user *from, char *to,
+                                           int copy, int offset)
+{
+        if (skb->ip_summed == CHECKSUM_NONE) {
+                int err = 0;
+                __wsum csum = csum_and_copy_from_user(from, to, copy, 0, &err);
+                if (err)
+                        return err;
+                skb->csum = csum_block_add(skb->csum, csum, offset);
+        } else if (sk->sk_route_caps & NETIF_F_NOCACHE_COPY) {
+                if (!access_ok(VERIFY_READ, from, copy) ||
+                    __copy_from_user_nocache(to, from, copy))
+                        return -EFAULT;
+        } else if (copy_from_user(to, from, copy))
+                return -EFAULT;
+
+        return 0;
+}
+
+static inline int skb_add_data_nocache(struct sock *sk, struct sk_buff *skb,
+                                       char __user *from, int copy)
+{
+        int err, offset = skb->len;
+
+        err = skb_do_copy_data_nocache(sk, skb, from, skb_put(skb, copy),
+                                       copy, offset);
+        if (err)
+                __skb_trim(skb, offset);
+
+        return err;
+}
+
+static inline int skb_copy_to_page_nocache(struct sock *sk, char __user *from,
+                                           struct sk_buff *skb,
+                                           struct page *page,
+                                           int off, int copy)
+{
+        int err;
+
+        err = skb_do_copy_data_nocache(sk, skb, from, page_address(page) + off,
+                                       copy, skb->len);
+        if (err)
+                return err;
+
+        skb->len             += copy;
+        skb->data_len        += copy;
+        skb->truesize        += copy;
+        sk->sk_wmem_queued   += copy;
+        sk_mem_charge(sk, copy);
+        return 0;
+}
+
 static inline int skb_copy_to_page(struct sock *sk, char __user *from,
                                    struct sk_buff *skb, struct page *page,
                                    int off, int copy)