#ifndef _LINUX_SKBUFF_H
#define _LINUX_SKBUFF_H
-#include <linux/config.h>
#include <linux/kernel.h>
#include <linux/compiler.h>
#include <linux/time.h>
#include <linux/net.h>
#include <linux/textsearch.h>
#include <net/checksum.h>
+#include <linux/dmaengine.h>
#define HAVE_ALLOC_SKB /* For the drivers to know */
#define HAVE_ALIGNABLE_SKB /* Ditto 8) */
* @nf_bridge: Saved data about a bridged frame - see br_netfilter.c
* @tc_index: Traffic control index
* @tc_verd: traffic control verdict
+ * @secmark: security marking
*/
struct sk_buff {
__u16 tc_verd; /* traffic control verdict */
#endif
#endif
+#ifdef CONFIG_NET_DMA
+ dma_cookie_t dma_cookie;
+#endif
+#ifdef CONFIG_NETWORK_SECMARK
+ __u32 secmark;
+#endif
/* These elements must be at the end, see alloc_skb() for details. */
void *here);
extern void skb_under_panic(struct sk_buff *skb, int len,
void *here);
+extern void skb_truesize_bug(struct sk_buff *skb);
+
+static inline void skb_truesize_check(struct sk_buff *skb)
+{
+ if (unlikely((int)skb->truesize < sizeof(struct sk_buff) + skb->len))
+ skb_truesize_bug(skb);
+}
extern int skb_append_datato_frags(struct sock *sk, struct sk_buff *skb,
int getfrag(void *from, char *to, int offset,
#define NET_IP_ALIGN 2
#endif
-extern int ___pskb_trim(struct sk_buff *skb, unsigned int len, int realloc);
+/*
+ * The networking layer reserves some headroom in skb data (via
+ * dev_alloc_skb). This is used to avoid having to reallocate skb data when
+ * the header has to grow. In the default case, if the header has to grow
+ * 16 bytes or less we avoid the reallocation.
+ *
+ * Unfortunately this headroom changes the DMA alignment of the resulting
+ * network packet. As for NET_IP_ALIGN, this unaligned DMA is expensive
+ * on some architectures. An architecture can override this value,
+ * perhaps setting it to a cacheline in size (since that will maintain
+ * cacheline alignment of the DMA). It must be a power of 2.
+ *
+ * Various parts of the networking layer expect at least 16 bytes of
+ * headroom, you should not reduce this.
+ */
+#ifndef NET_SKB_PAD
+#define NET_SKB_PAD 16
+#endif
+
+extern int ___pskb_trim(struct sk_buff *skb, unsigned int len);
static inline void __skb_trim(struct sk_buff *skb, unsigned int len)
{
- if (!skb->data_len) {
- skb->len = len;
- skb->tail = skb->data + len;
- } else
- ___pskb_trim(skb, len, 0);
+ if (unlikely(skb->data_len)) {
+ WARN_ON(1);
+ return;
+ }
+ skb->len = len;
+ skb->tail = skb->data + len;
}
/**
*
* Cut the length of a buffer down by removing data from the tail. If
* the buffer is already under the length specified it is not modified.
+ * The skb must be linear.
*/
static inline void skb_trim(struct sk_buff *skb, unsigned int len)
{
static inline int __pskb_trim(struct sk_buff *skb, unsigned int len)
{
- if (!skb->data_len) {
- skb->len = len;
- skb->tail = skb->data+len;
- return 0;
- }
- return ___pskb_trim(skb, len, 1);
+ if (skb->data_len)
+ return ___pskb_trim(skb, len);
+ __skb_trim(skb, len);
+ return 0;
}
static inline int pskb_trim(struct sk_buff *skb, unsigned int len)
static inline struct sk_buff *__dev_alloc_skb(unsigned int length,
gfp_t gfp_mask)
{
- struct sk_buff *skb = alloc_skb(length + 16, gfp_mask);
+ struct sk_buff *skb = alloc_skb(length + NET_SKB_PAD, gfp_mask);
if (likely(skb))
- skb_reserve(skb, 16);
+ skb_reserve(skb, NET_SKB_PAD);
return skb;
}
#else
*/
static inline int skb_cow(struct sk_buff *skb, unsigned int headroom)
{
- int delta = (headroom > 16 ? headroom : 16) - skb_headroom(skb);
+ int delta = (headroom > NET_SKB_PAD ? headroom : NET_SKB_PAD) -
+ skb_headroom(skb);
if (delta < 0)
delta = 0;
if (delta || skb_cloned(skb))
- return pskb_expand_head(skb, (delta + 15) & ~15, 0, GFP_ATOMIC);
+ return pskb_expand_head(skb, (delta + (NET_SKB_PAD-1)) &
+ ~(NET_SKB_PAD-1), 0, GFP_ATOMIC);
return 0;
}
return 0;
}
+static inline int __skb_linearize(struct sk_buff *skb)
+{
+ return __pskb_pull_tail(skb, skb->data_len) ? 0 : -ENOMEM;
+}
+
/**
* skb_linearize - convert paged skb to linear one
* @skb: buffer to linarize
- * @gfp: allocation mode
*
* If there is no free memory -ENOMEM is returned, otherwise zero
* is returned and the old skb data released.
*/
-extern int __skb_linearize(struct sk_buff *skb, gfp_t gfp);
-static inline int skb_linearize(struct sk_buff *skb, gfp_t gfp)
+static inline int skb_linearize(struct sk_buff *skb)
{
- return __skb_linearize(skb, gfp);
+ return skb_is_nonlinear(skb) ? __skb_linearize(skb) : 0;
+}
+
+/**
+ * skb_linearize_cow - make sure skb is linear and writable
+ * @skb: buffer to process
+ *
+ * If there is no free memory -ENOMEM is returned, otherwise zero
+ * is returned and the old skb data released.
+ */
+static inline int skb_linearize_cow(struct sk_buff *skb)
+{
+ return skb_is_nonlinear(skb) || skb_cloned(skb) ?
+ __skb_linearize(skb) : 0;
}
/**
static inline void nf_reset(struct sk_buff *skb) {}
#endif /* CONFIG_NETFILTER */
+#ifdef CONFIG_NETWORK_SECMARK
+static inline void skb_copy_secmark(struct sk_buff *to, const struct sk_buff *from)
+{
+ to->secmark = from->secmark;
+}
+
+static inline void skb_init_secmark(struct sk_buff *skb)
+{
+ skb->secmark = 0;
+}
+#else
+static inline void skb_copy_secmark(struct sk_buff *to, const struct sk_buff *from)
+{ }
+
+static inline void skb_init_secmark(struct sk_buff *skb)
+{ }
+#endif
+
#endif /* __KERNEL__ */
#endif /* _LINUX_SKBUFF_H */