1 #ifndef __LINUX_SKBUFF_WRAPPER_H
2 #define __LINUX_SKBUFF_WRAPPER_H 1
4 #include_next <linux/skbuff.h>
6 #include <linux/version.h>
8 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,24)
9 /* In version 2.6.24 the return type of skb_headroom() changed from 'int' to
10 * 'unsigned int'. We use skb_headroom() as one arm of a min(a,b) invocation
11 * in make_writable() in actions.c, so we need the correct type. */
12 #define skb_headroom rpl_skb_headroom
13 static inline unsigned int rpl_skb_headroom(const struct sk_buff *skb)
15 return skb->data - skb->head;
19 #ifndef HAVE_SKB_COPY_FROM_LINEAR_DATA_OFFSET
20 static inline void skb_copy_from_linear_data_offset(const struct sk_buff *skb,
21 const int offset, void *to,
22 const unsigned int len)
24 memcpy(to, skb->data + offset, len);
27 static inline void skb_copy_to_linear_data_offset(struct sk_buff *skb,
30 const unsigned int len)
32 memcpy(skb->data + offset, from, len);
35 #endif /* !HAVE_SKB_COPY_FROM_LINEAR_DATA_OFFSET */
38 * The networking layer reserves some headroom in skb data (via
39 * dev_alloc_skb). This is used to avoid having to reallocate skb data when
40 * the header has to grow. In the default case, if the header has to grow
41 * 16 bytes or less we avoid the reallocation.
43 * Unfortunately this headroom changes the DMA alignment of the resulting
44 * network packet. As for NET_IP_ALIGN, this unaligned DMA is expensive
45 * on some architectures. An architecture can override this value,
46 * perhaps setting it to a cacheline in size (since that will maintain
47 * cacheline alignment of the DMA). It must be a power of 2.
49 * Various parts of the networking layer expect at least 16 bytes of
50 * headroom, you should not reduce this.
53 #define NET_SKB_PAD 16
57 static inline int __skb_cow(struct sk_buff *skb, unsigned int headroom,
62 if (headroom < NET_SKB_PAD)
63 headroom = NET_SKB_PAD;
64 if (headroom > skb_headroom(skb))
65 delta = headroom - skb_headroom(skb);
68 return pskb_expand_head(skb, ALIGN(delta, NET_SKB_PAD), 0,
73 static inline int skb_cow_head(struct sk_buff *skb, unsigned int headroom)
75 return __skb_cow(skb, headroom, skb_header_cloned(skb));
77 #endif /* !HAVE_SKB_COW */
80 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,17)
81 /* Emulate Linux 2.6.17 and later behavior, in which kfree_skb silently ignores
82 * null pointer arguments. */
83 #define kfree_skb(skb) kfree_skb_maybe_null(skb)
84 static inline void kfree_skb_maybe_null(struct sk_buff *skb)
86 if (likely(skb != NULL))
92 #ifndef CHECKSUM_PARTIAL
93 /* Note that CHECKSUM_PARTIAL is not implemented, but this allows us to at
94 * least test against it: see update_csum() in forward.c. */
95 #define CHECKSUM_PARTIAL 3
97 #ifndef CHECKSUM_COMPLETE
98 #define CHECKSUM_COMPLETE CHECKSUM_HW
102 #define mac_header mac.raw
103 #define network_header nh.raw
106 #ifndef HAVE_SKBUFF_HEADER_HELPERS
107 static inline unsigned char *skb_transport_header(const struct sk_buff *skb)
112 static inline void skb_reset_transport_header(struct sk_buff *skb)
114 skb->h.raw = skb->data;
117 static inline void skb_set_transport_header(struct sk_buff *skb,
120 skb->h.raw = skb->data + offset;
123 static inline unsigned char *skb_network_header(const struct sk_buff *skb)
128 static inline void skb_set_network_header(struct sk_buff *skb, const int offset)
130 skb->nh.raw = skb->data + offset;
133 static inline unsigned char *skb_mac_header(const struct sk_buff *skb)
138 static inline void skb_reset_mac_header(struct sk_buff *skb)
140 skb->mac_header = skb->data;
143 static inline void skb_set_mac_header(struct sk_buff *skb, const int offset)
145 skb->mac.raw = skb->data + offset;
148 static inline int skb_transport_offset(const struct sk_buff *skb)
150 return skb_transport_header(skb) - skb->data;
153 static inline int skb_network_offset(const struct sk_buff *skb)
155 return skb_network_header(skb) - skb->data;
158 static inline void skb_copy_to_linear_data(struct sk_buff *skb,
160 const unsigned int len)
162 memcpy(skb->data, from, len);
164 #endif /* !HAVE_SKBUFF_HEADER_HELPERS */
166 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,18)
167 #warning "TSO/UFO not supported on kernels earlier than 2.6.18"
169 static inline int skb_is_gso(const struct sk_buff *skb)
174 static inline struct sk_buff *skb_gso_segment(struct sk_buff *skb,
179 #endif /* before 2.6.18 */