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-rw-r--r--include/linux/skbuff.h111
1 files changed, 110 insertions, 1 deletions
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index b1831a5ca173..88f7541837e3 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -245,6 +245,7 @@ struct iov_iter;
struct napi_struct;
struct bpf_prog;
union bpf_attr;
+struct skb_ext;
#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
struct nf_conntrack {
@@ -636,6 +637,7 @@ typedef unsigned char *sk_buff_data_t;
* @queue_mapping: Queue mapping for multiqueue devices
* @xmit_more: More SKBs are pending for this queue
* @pfmemalloc: skbuff was allocated from PFMEMALLOC reserves
+ * @active_extensions: active extensions (skb_ext_id types)
* @ndisc_nodetype: router type (from link layer)
* @ooo_okay: allow the mapping of a socket to a queue to be changed
* @l4_hash: indicate hash is a canonical 4-tuple hash over transport
@@ -665,6 +667,7 @@ typedef unsigned char *sk_buff_data_t;
* @data: Data head pointer
* @truesize: Buffer size
* @users: User count - see {datagram,tcp}.c
+ * @extensions: allocated extensions, valid if active_extensions is nonzero
*/
struct sk_buff {
@@ -747,7 +750,9 @@ struct sk_buff {
head_frag:1,
xmit_more:1,
pfmemalloc:1;
-
+#ifdef CONFIG_SKB_EXTENSIONS
+ __u8 active_extensions;
+#endif
/* fields enclosed in headers_start/headers_end are copied
* using a single memcpy() in __copy_skb_header()
*/
@@ -869,6 +874,11 @@ struct sk_buff {
*data;
unsigned int truesize;
refcount_t users;
+
+#ifdef CONFIG_SKB_EXTENSIONS
+ /* only useable after checking ->active_extensions != 0 */
+ struct skb_ext *extensions;
+#endif
};
#ifdef __KERNEL__
@@ -3896,6 +3906,105 @@ static inline void nf_conntrack_get(struct nf_conntrack *nfct)
atomic_inc(&nfct->use);
}
#endif
+
+#ifdef CONFIG_SKB_EXTENSIONS
+enum skb_ext_id {
+#if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
+ SKB_EXT_BRIDGE_NF,
+#endif
+ SKB_EXT_NUM, /* must be last */
+};
+
+/**
+ * struct skb_ext - sk_buff extensions
+ * @refcnt: 1 on allocation, deallocated on 0
+ * @offset: offset to add to @data to obtain extension address
+ * @chunks: size currently allocated, stored in SKB_EXT_ALIGN_SHIFT units
+ * @data: start of extension data, variable sized
+ *
+ * Note: offsets/lengths are stored in chunks of 8 bytes, this allows
+ * to use 'u8' types while allowing up to 2kb worth of extension data.
+ */
+struct skb_ext {
+ refcount_t refcnt;
+ u8 offset[SKB_EXT_NUM]; /* in chunks of 8 bytes */
+ u8 chunks; /* same */
+ char data[0] __aligned(8);
+};
+
+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);
+
+static inline void skb_ext_put(struct sk_buff *skb)
+{
+ if (skb->active_extensions)
+ __skb_ext_put(skb->extensions);
+}
+
+static inline void skb_ext_get(struct sk_buff *skb)
+{
+ if (skb->active_extensions) {
+ struct skb_ext *ext = skb->extensions;
+
+ if (ext)
+ refcount_inc(&ext->refcnt);
+ }
+}
+
+static inline void __skb_ext_copy(struct sk_buff *dst,
+ const struct sk_buff *src)
+{
+ dst->active_extensions = src->active_extensions;
+
+ if (src->active_extensions) {
+ struct skb_ext *ext = src->extensions;
+
+ refcount_inc(&ext->refcnt);
+ dst->extensions = ext;
+ }
+}
+
+static inline void skb_ext_copy(struct sk_buff *dst, const struct sk_buff *src)
+{
+ skb_ext_put(dst);
+ __skb_ext_copy(dst, src);
+}
+
+static inline bool __skb_ext_exist(const struct skb_ext *ext, enum skb_ext_id i)
+{
+ return !!ext->offset[i];
+}
+
+static inline bool skb_ext_exist(const struct sk_buff *skb, enum skb_ext_id id)
+{
+ return skb->active_extensions & (1 << id);
+}
+
+static inline void skb_ext_del(struct sk_buff *skb, enum skb_ext_id id)
+{
+ if (skb_ext_exist(skb, id))
+ __skb_ext_del(skb, id);
+}
+
+static inline void *skb_ext_find(const struct sk_buff *skb, enum skb_ext_id id)
+{
+ if (skb_ext_exist(skb, id)) {
+ struct skb_ext *ext = skb->extensions;
+
+ return (void *)ext + (ext->offset[id] << 3);
+ }
+
+ return NULL;
+}
+#else
+static inline void skb_ext_put(struct sk_buff *skb) {}
+static inline void skb_ext_get(struct sk_buff *skb) {}
+static inline void skb_ext_del(struct sk_buff *skb, int unused) {}
+static inline void __skb_ext_copy(struct sk_buff *d, const struct sk_buff *s) {}
+static inline void skb_ext_copy(struct sk_buff *dst, const struct sk_buff *s) {}
+#endif /* CONFIG_SKB_EXTENSIONS */
+
#if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
static inline void nf_bridge_put(struct nf_bridge_info *nf_bridge)
{