* Any questions? No questions, good. --ANK
*/
-#ifdef __i386__
-#define NET_CALLER(arg) (*(((void **)&arg) - 1))
-#else
-#define NET_CALLER(arg) __builtin_return_address(0)
-#endif
-
struct net_device;
#ifdef CONFIG_NETFILTER
skb_frag_t frags[MAX_SKB_FRAGS];
};
+/* We divide dataref into two halves. The higher 16 bits hold references
+ * to the payload part of skb->data. The lower 16 bits hold references to
+ * the entire skb->data. It is up to the users of the skb to agree on
+ * where the payload starts.
+ *
+ * All users must obey the rule that the skb->data reference count must be
+ * greater than or equal to the payload reference count.
+ *
+ * Holding a reference to the payload part means that the user does not
+ * care about modifications to the header part of skb->data.
+ */
+#define SKB_DATAREF_SHIFT 16
+#define SKB_DATAREF_MASK ((1 << SKB_DATAREF_SHIFT) - 1)
+
/**
* struct sk_buff - socket buffer
* @next: Next buffer in list
* @h: Transport layer header
* @nh: Network layer header
* @mac: Link layer header
- * @dst: FIXME: Describe this field
+ * @dst: destination entry
+ * @sp: the security path, used for xfrm
* @cb: Control buffer. Free for use by every layer. Put private vars here
* @len: Length of actual data
* @data_len: Data length
* @mac_len: Length of link layer header
* @csum: Checksum
- * @__unused: Dead field, may be reused
+ * @local_df: allow local fragmentation
* @cloned: Head may be cloned (check refcnt to be sure)
+ * @nohdr: Payload reference only, must not modify header
* @pkt_type: Packet class
* @ip_summed: Driver fed us an IP checksum
* @priority: Packet queueing priority
* @nf_bridge: Saved data about a bridged frame - see br_netfilter.c
* @private: Data which is private to the HIPPI implementation
* @tc_index: Traffic control index
+ * @tc_verd: traffic control verdict
+ * @tc_classid: traffic control classid
*/
struct sk_buff {
mac_len,
csum;
unsigned char local_df,
- cloned,
+ cloned:1,
+ nohdr:1,
pkt_type,
ip_summed;
__u32 priority;
*/
static inline int skb_cloned(const struct sk_buff *skb)
{
- return skb->cloned && atomic_read(&skb_shinfo(skb)->dataref) != 1;
+ return skb->cloned &&
+ (atomic_read(&skb_shinfo(skb)->dataref) & SKB_DATAREF_MASK) != 1;
+}
+
+/**
+ * skb_header_cloned - is the header a clone
+ * @skb: buffer to check
+ *
+ * Returns true if modifying the header part of the buffer requires
+ * the data to be copied.
+ */
+static inline int skb_header_cloned(const struct sk_buff *skb)
+{
+ int dataref;
+
+ if (!skb->cloned)
+ return 0;
+
+ dataref = atomic_read(&skb_shinfo(skb)->dataref);
+ dataref = (dataref & SKB_DATAREF_MASK) - (dataref >> SKB_DATAREF_SHIFT);
+ return dataref != 1;
+}
+
+/**
+ * skb_header_release - release reference to header
+ * @skb: buffer to operate on
+ *
+ * Drop a reference to the header part of the buffer. This is done
+ * by acquiring a payload reference. You must not read from the header
+ * part of skb->data after this.
+ */
+static inline void skb_header_release(struct sk_buff *skb)
+{
+ BUG_ON(skb->nohdr);
+ skb->nohdr = 1;
+ atomic_add(1 << SKB_DATAREF_SHIFT, &skb_shinfo(skb)->dataref);
}
/**
kfree_skb(skb);
}
+#ifndef CONFIG_HAVE_ARCH_DEV_ALLOC_SKB
/**
* __dev_alloc_skb - allocate an skbuff for sending
* @length: length to allocate
*
* %NULL is returned in there is no free memory.
*/
-#ifndef CONFIG_HAVE_ARCH_DEV_ALLOC_SKB
static inline struct sk_buff *__dev_alloc_skb(unsigned int length,
int gfp_mask)
{
return __skb_linearize(skb, gfp);
}
+/**
+ * skb_postpull_rcsum - update checksum for received skb after pull
+ * @skb: buffer to update
+ * @start: start of data before pull
+ * @len: length of data pulled
+ *
+ * After doing a pull on a received packet, you need to call this to
+ * update the CHECKSUM_HW checksum, or set ip_summed to CHECKSUM_NONE
+ * so that it can be recomputed from scratch.
+ */
+
+static inline void skb_postpull_rcsum(struct sk_buff *skb,
+ const void *start, int len)
+{
+ if (skb->ip_summed == CHECKSUM_HW)
+ skb->csum = csum_sub(skb->csum, csum_partial(start, len, 0));
+}
+
+/**
+ * pskb_trim_rcsum - trim received skb and update checksum
+ * @skb: buffer to trim
+ * @len: new length
+ *
+ * This is exactly the same as pskb_trim except that it ensures the
+ * checksum of received packets are still valid after the operation.
+ */
+
+static inline int pskb_trim_rcsum(struct sk_buff *skb, unsigned int len)
+{
+ if (len >= skb->len)
+ return 0;
+ if (skb->ip_summed == CHECKSUM_HW)
+ skb->ip_summed = CHECKSUM_NONE;
+ return __pskb_trim(skb, len);
+}
+
static inline void *kmap_skb_frag(const skb_frag_t *frag)
{
#ifdef CONFIG_HIGHMEM
int len, unsigned int csum);
extern int skb_copy_bits(const struct sk_buff *skb, int offset,
void *to, int len);
+extern int skb_store_bits(const struct sk_buff *skb, int offset,
+ void *from, int len);
extern unsigned int skb_copy_and_csum_bits(const struct sk_buff *skb,
int offset, u8 *to, int len,
unsigned int csum);
extern void skb_init(void);
extern void skb_add_mtu(int mtu);
-struct skb_iter {
- /* Iteration functions set these */
- unsigned char *data;
- unsigned int len;
-
- /* Private to iteration */
- unsigned int nextfrag;
- struct sk_buff *fraglist;
-};
-
-/* Keep iterating until skb_iter_next returns false. */
-extern void skb_iter_first(const struct sk_buff *skb, struct skb_iter *i);
-extern int skb_iter_next(const struct sk_buff *skb, struct skb_iter *i);
-/* Call this if aborting loop before !skb_iter_next */
-extern void skb_iter_abort(const struct sk_buff *skb, struct skb_iter *i);
-
#ifdef CONFIG_NETFILTER
static inline void nf_conntrack_put(struct nf_conntrack *nfct)
{
git://git.onelab.eu / linux-2.6.git / blobdiff