diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 1a261c3ee074c..af9b6cf79a65b 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -4115,6 +4115,9 @@ struct skb_ext { char data[0] __aligned(8); }; +struct skb_ext *__skb_ext_alloc(void); +void *__skb_ext_set(struct sk_buff *skb, enum skb_ext_id id, + struct skb_ext *ext); void *skb_ext_add(struct sk_buff *skb, enum skb_ext_id id); void __skb_ext_del(struct sk_buff *skb, enum skb_ext_id id); void __skb_ext_put(struct skb_ext *ext); diff --git a/net/core/skbuff.c b/net/core/skbuff.c index fa67036dd9285..504e9bd5ebcee 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -5983,7 +5983,14 @@ static void *skb_ext_get_ptr(struct skb_ext *ext, enum skb_ext_id id) return (void *)ext + (ext->offset[id] * SKB_EXT_ALIGN_VALUE); } -static struct skb_ext *skb_ext_alloc(void) +/** + * __skb_ext_alloc - allocate a new skb extensions storage + * + * Returns the newly allocated pointer. The pointer can later attached to a + * skb via __skb_ext_set(). + * Note: caller must handle the skb_ext as an opaque data. + */ +struct skb_ext *__skb_ext_alloc(void) { struct skb_ext *new = kmem_cache_alloc(skbuff_ext_cache, GFP_ATOMIC); @@ -6023,6 +6030,30 @@ static struct skb_ext *skb_ext_maybe_cow(struct skb_ext *old, return new; } +/** + * __skb_ext_set - attach the specified extension storage to this skb + * @skb: buffer + * @id: extension id + * @ext: extension storage previously allocated via __skb_ext_alloc() + * + * Existing extensions, if any, are cleared. + * + * Returns the pointer to the extension. + */ +void *__skb_ext_set(struct sk_buff *skb, enum skb_ext_id id, + struct skb_ext *ext) +{ + unsigned int newlen, newoff = SKB_EXT_CHUNKSIZEOF(*ext); + + skb_ext_put(skb); + newlen = newoff + skb_ext_type_len[id]; + ext->chunks = newlen; + ext->offset[id] = newoff; + skb->extensions = ext; + skb->active_extensions = 1 << id; + return skb_ext_get_ptr(ext, id); +} + /** * skb_ext_add - allocate space for given extension, COW if needed * @skb: buffer @@ -6056,7 +6087,7 @@ void *skb_ext_add(struct sk_buff *skb, enum skb_ext_id id) } else { newoff = SKB_EXT_CHUNKSIZEOF(*new); - new = skb_ext_alloc(); + new = __skb_ext_alloc(); if (!new) return NULL; }