skb: add helpers to allocate ext independently from sk_buff (8b69a803) · Commits · 戴 / test

include/linux/skbuff.h

+3 −0

Original line number	Diff line number	Diff line
		@@ -4120,6 +4120,9 @@ 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);

net/core/skbuff.c

+33 −2

Original line number	Diff line number	Diff line
		@@ -5987,7 +5987,14 @@ 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);

		@@ -6027,6 +6034,30 @@ 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
		@@ -6060,7 +6091,7 @@ 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;
		}

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