Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
new file mode 100644
index 0000000..aa35797
--- /dev/null
+++ b/include/linux/skbuff.h
@@ -0,0 +1,1253 @@
+/*
+ * Definitions for the 'struct sk_buff' memory handlers.
+ *
+ * Authors:
+ * Alan Cox, <gw4pts@gw4pts.ampr.org>
+ * Florian La Roche, <rzsfl@rz.uni-sb.de>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#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/cache.h>
+
+#include <asm/atomic.h>
+#include <asm/types.h>
+#include <linux/spinlock.h>
+#include <linux/mm.h>
+#include <linux/highmem.h>
+#include <linux/poll.h>
+#include <linux/net.h>
+#include <net/checksum.h>
+
+#define HAVE_ALLOC_SKB /* For the drivers to know */
+#define HAVE_ALIGNABLE_SKB /* Ditto 8) */
+#define SLAB_SKB /* Slabified skbuffs */
+
+#define CHECKSUM_NONE 0
+#define CHECKSUM_HW 1
+#define CHECKSUM_UNNECESSARY 2
+
+#define SKB_DATA_ALIGN(X) (((X) + (SMP_CACHE_BYTES - 1)) & \
+ ~(SMP_CACHE_BYTES - 1))
+#define SKB_MAX_ORDER(X, ORDER) (((PAGE_SIZE << (ORDER)) - (X) - \
+ sizeof(struct skb_shared_info)) & \
+ ~(SMP_CACHE_BYTES - 1))
+#define SKB_MAX_HEAD(X) (SKB_MAX_ORDER((X), 0))
+#define SKB_MAX_ALLOC (SKB_MAX_ORDER(0, 2))
+
+/* A. Checksumming of received packets by device.
+ *
+ * NONE: device failed to checksum this packet.
+ * skb->csum is undefined.
+ *
+ * UNNECESSARY: device parsed packet and wouldbe verified checksum.
+ * skb->csum is undefined.
+ * It is bad option, but, unfortunately, many of vendors do this.
+ * Apparently with secret goal to sell you new device, when you
+ * will add new protocol to your host. F.e. IPv6. 8)
+ *
+ * HW: the most generic way. Device supplied checksum of _all_
+ * the packet as seen by netif_rx in skb->csum.
+ * NOTE: Even if device supports only some protocols, but
+ * is able to produce some skb->csum, it MUST use HW,
+ * not UNNECESSARY.
+ *
+ * B. Checksumming on output.
+ *
+ * NONE: skb is checksummed by protocol or csum is not required.
+ *
+ * HW: device is required to csum packet as seen by hard_start_xmit
+ * from skb->h.raw to the end and to record the checksum
+ * at skb->h.raw+skb->csum.
+ *
+ * Device must show its capabilities in dev->features, set
+ * at device setup time.
+ * NETIF_F_HW_CSUM - it is clever device, it is able to checksum
+ * everything.
+ * NETIF_F_NO_CSUM - loopback or reliable single hop media.
+ * NETIF_F_IP_CSUM - device is dumb. It is able to csum only
+ * TCP/UDP over IPv4. Sigh. Vendors like this
+ * way by an unknown reason. Though, see comment above
+ * about CHECKSUM_UNNECESSARY. 8)
+ *
+ * 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
+struct nf_conntrack {
+ atomic_t use;
+ void (*destroy)(struct nf_conntrack *);
+};
+
+#ifdef CONFIG_BRIDGE_NETFILTER
+struct nf_bridge_info {
+ atomic_t use;
+ struct net_device *physindev;
+ struct net_device *physoutdev;
+#if defined(CONFIG_VLAN_8021Q) || defined(CONFIG_VLAN_8021Q_MODULE)
+ struct net_device *netoutdev;
+#endif
+ unsigned int mask;
+ unsigned long data[32 / sizeof(unsigned long)];
+};
+#endif
+
+#endif
+
+struct sk_buff_head {
+ /* These two members must be first. */
+ struct sk_buff *next;
+ struct sk_buff *prev;
+
+ __u32 qlen;
+ spinlock_t lock;
+};
+
+struct sk_buff;
+
+/* To allow 64K frame to be packed as single skb without frag_list */
+#define MAX_SKB_FRAGS (65536/PAGE_SIZE + 2)
+
+typedef struct skb_frag_struct skb_frag_t;
+
+struct skb_frag_struct {
+ struct page *page;
+ __u16 page_offset;
+ __u16 size;
+};
+
+/* This data is invariant across clones and lives at
+ * the end of the header data, ie. at skb->end.
+ */
+struct skb_shared_info {
+ atomic_t dataref;
+ unsigned int nr_frags;
+ unsigned short tso_size;
+ unsigned short tso_segs;
+ struct sk_buff *frag_list;
+ 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
+ * @prev: Previous buffer in list
+ * @list: List we are on
+ * @sk: Socket we are owned by
+ * @stamp: Time we arrived
+ * @dev: Device we arrived on/are leaving by
+ * @input_dev: Device we arrived on
+ * @real_dev: The real device we are using
+ * @h: Transport layer header
+ * @nh: Network layer header
+ * @mac: Link layer header
+ * @dst: FIXME: Describe this field
+ * @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
+ * @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
+ * @users: User count - see {datagram,tcp}.c
+ * @protocol: Packet protocol from driver
+ * @security: Security level of packet
+ * @truesize: Buffer size
+ * @head: Head of buffer
+ * @data: Data head pointer
+ * @tail: Tail pointer
+ * @end: End pointer
+ * @destructor: Destruct function
+ * @nfmark: Can be used for communication between hooks
+ * @nfcache: Cache info
+ * @nfct: Associated connection, if any
+ * @nfctinfo: Relationship of this skb to the connection
+ * @nf_debug: Netfilter debugging
+ * @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 {
+ /* These two members must be first. */
+ struct sk_buff *next;
+ struct sk_buff *prev;
+
+ struct sk_buff_head *list;
+ struct sock *sk;
+ struct timeval stamp;
+ struct net_device *dev;
+ struct net_device *input_dev;
+ struct net_device *real_dev;
+
+ union {
+ struct tcphdr *th;
+ struct udphdr *uh;
+ struct icmphdr *icmph;
+ struct igmphdr *igmph;
+ struct iphdr *ipiph;
+ struct ipv6hdr *ipv6h;
+ unsigned char *raw;
+ } h;
+
+ union {
+ struct iphdr *iph;
+ struct ipv6hdr *ipv6h;
+ struct arphdr *arph;
+ unsigned char *raw;
+ } nh;
+
+ union {
+ unsigned char *raw;
+ } mac;
+
+ struct dst_entry *dst;
+ struct sec_path *sp;
+
+ /*
+ * This is the control buffer. It is free to use for every
+ * layer. Please put your private variables there. If you
+ * want to keep them across layers you have to do a skb_clone()
+ * first. This is owned by whoever has the skb queued ATM.
+ */
+ char cb[40];
+
+ unsigned int len,
+ data_len,
+ mac_len,
+ csum;
+ unsigned char local_df,
+ cloned:1,
+ nohdr:1,
+ pkt_type,
+ ip_summed;
+ __u32 priority;
+ unsigned short protocol,
+ security;
+
+ void (*destructor)(struct sk_buff *skb);
+#ifdef CONFIG_NETFILTER
+ unsigned long nfmark;
+ __u32 nfcache;
+ __u32 nfctinfo;
+ struct nf_conntrack *nfct;
+#ifdef CONFIG_NETFILTER_DEBUG
+ unsigned int nf_debug;
+#endif
+#ifdef CONFIG_BRIDGE_NETFILTER
+ struct nf_bridge_info *nf_bridge;
+#endif
+#endif /* CONFIG_NETFILTER */
+#if defined(CONFIG_HIPPI)
+ union {
+ __u32 ifield;
+ } private;
+#endif
+#ifdef CONFIG_NET_SCHED
+ __u32 tc_index; /* traffic control index */
+#ifdef CONFIG_NET_CLS_ACT
+ __u32 tc_verd; /* traffic control verdict */
+ __u32 tc_classid; /* traffic control classid */
+#endif
+
+#endif
+
+
+ /* These elements must be at the end, see alloc_skb() for details. */
+ unsigned int truesize;
+ atomic_t users;
+ unsigned char *head,
+ *data,
+ *tail,
+ *end;
+};
+
+#ifdef __KERNEL__
+/*
+ * Handling routines are only of interest to the kernel
+ */
+#include <linux/slab.h>
+
+#include <asm/system.h>
+
+extern void __kfree_skb(struct sk_buff *skb);
+extern struct sk_buff *alloc_skb(unsigned int size, int priority);
+extern struct sk_buff *alloc_skb_from_cache(kmem_cache_t *cp,
+ unsigned int size, int priority);
+extern void kfree_skbmem(struct sk_buff *skb);
+extern struct sk_buff *skb_clone(struct sk_buff *skb, int priority);
+extern struct sk_buff *skb_copy(const struct sk_buff *skb, int priority);
+extern struct sk_buff *pskb_copy(struct sk_buff *skb, int gfp_mask);
+extern int pskb_expand_head(struct sk_buff *skb,
+ int nhead, int ntail, int gfp_mask);
+extern struct sk_buff *skb_realloc_headroom(struct sk_buff *skb,
+ unsigned int headroom);
+extern struct sk_buff *skb_copy_expand(const struct sk_buff *skb,
+ int newheadroom, int newtailroom,
+ int priority);
+extern struct sk_buff * skb_pad(struct sk_buff *skb, int pad);
+#define dev_kfree_skb(a) kfree_skb(a)
+extern void skb_over_panic(struct sk_buff *skb, int len,
+ void *here);
+extern void skb_under_panic(struct sk_buff *skb, int len,
+ void *here);
+
+/* Internal */
+#define skb_shinfo(SKB) ((struct skb_shared_info *)((SKB)->end))
+
+/**
+ * skb_queue_empty - check if a queue is empty
+ * @list: queue head
+ *
+ * Returns true if the queue is empty, false otherwise.
+ */
+static inline int skb_queue_empty(const struct sk_buff_head *list)
+{
+ return list->next == (struct sk_buff *)list;
+}
+
+/**
+ * skb_get - reference buffer
+ * @skb: buffer to reference
+ *
+ * Makes another reference to a socket buffer and returns a pointer
+ * to the buffer.
+ */
+static inline struct sk_buff *skb_get(struct sk_buff *skb)
+{
+ atomic_inc(&skb->users);
+ return skb;
+}
+
+/*
+ * If users == 1, we are the only owner and are can avoid redundant
+ * atomic change.
+ */
+
+/**
+ * kfree_skb - free an sk_buff
+ * @skb: buffer to free
+ *
+ * Drop a reference to the buffer and free it if the usage count has
+ * hit zero.
+ */
+static inline void kfree_skb(struct sk_buff *skb)
+{
+ if (likely(atomic_read(&skb->users) == 1))
+ smp_rmb();
+ else if (likely(!atomic_dec_and_test(&skb->users)))
+ return;
+ __kfree_skb(skb);
+}
+
+/**
+ * skb_cloned - is the buffer a clone
+ * @skb: buffer to check
+ *
+ * Returns true if the buffer was generated with skb_clone() and is
+ * one of multiple shared copies of the buffer. Cloned buffers are
+ * shared data so must not be written to under normal circumstances.
+ */
+static inline int skb_cloned(const struct sk_buff *skb)
+{
+ 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);
+}
+
+/**
+ * skb_shared - is the buffer shared
+ * @skb: buffer to check
+ *
+ * Returns true if more than one person has a reference to this
+ * buffer.
+ */
+static inline int skb_shared(const struct sk_buff *skb)
+{
+ return atomic_read(&skb->users) != 1;
+}
+
+/**
+ * skb_share_check - check if buffer is shared and if so clone it
+ * @skb: buffer to check
+ * @pri: priority for memory allocation
+ *
+ * If the buffer is shared the buffer is cloned and the old copy
+ * drops a reference. A new clone with a single reference is returned.
+ * If the buffer is not shared the original buffer is returned. When
+ * being called from interrupt status or with spinlocks held pri must
+ * be GFP_ATOMIC.
+ *
+ * NULL is returned on a memory allocation failure.
+ */
+static inline struct sk_buff *skb_share_check(struct sk_buff *skb, int pri)
+{
+ might_sleep_if(pri & __GFP_WAIT);
+ if (skb_shared(skb)) {
+ struct sk_buff *nskb = skb_clone(skb, pri);
+ kfree_skb(skb);
+ skb = nskb;
+ }
+ return skb;
+}
+
+/*
+ * Copy shared buffers into a new sk_buff. We effectively do COW on
+ * packets to handle cases where we have a local reader and forward
+ * and a couple of other messy ones. The normal one is tcpdumping
+ * a packet thats being forwarded.
+ */
+
+/**
+ * skb_unshare - make a copy of a shared buffer
+ * @skb: buffer to check
+ * @pri: priority for memory allocation
+ *
+ * If the socket buffer is a clone then this function creates a new
+ * copy of the data, drops a reference count on the old copy and returns
+ * the new copy with the reference count at 1. If the buffer is not a clone
+ * the original buffer is returned. When called with a spinlock held or
+ * from interrupt state @pri must be %GFP_ATOMIC
+ *
+ * %NULL is returned on a memory allocation failure.
+ */
+static inline struct sk_buff *skb_unshare(struct sk_buff *skb, int pri)
+{
+ might_sleep_if(pri & __GFP_WAIT);
+ if (skb_cloned(skb)) {
+ struct sk_buff *nskb = skb_copy(skb, pri);
+ kfree_skb(skb); /* Free our shared copy */
+ skb = nskb;
+ }
+ return skb;
+}
+
+/**
+ * skb_peek
+ * @list_: list to peek at
+ *
+ * Peek an &sk_buff. Unlike most other operations you _MUST_
+ * be careful with this one. A peek leaves the buffer on the
+ * list and someone else may run off with it. You must hold
+ * the appropriate locks or have a private queue to do this.
+ *
+ * Returns %NULL for an empty list or a pointer to the head element.
+ * The reference count is not incremented and the reference is therefore
+ * volatile. Use with caution.
+ */
+static inline struct sk_buff *skb_peek(struct sk_buff_head *list_)
+{
+ struct sk_buff *list = ((struct sk_buff *)list_)->next;
+ if (list == (struct sk_buff *)list_)
+ list = NULL;
+ return list;
+}
+
+/**
+ * skb_peek_tail
+ * @list_: list to peek at
+ *
+ * Peek an &sk_buff. Unlike most other operations you _MUST_
+ * be careful with this one. A peek leaves the buffer on the
+ * list and someone else may run off with it. You must hold
+ * the appropriate locks or have a private queue to do this.
+ *
+ * Returns %NULL for an empty list or a pointer to the tail element.
+ * The reference count is not incremented and the reference is therefore
+ * volatile. Use with caution.
+ */
+static inline struct sk_buff *skb_peek_tail(struct sk_buff_head *list_)
+{
+ struct sk_buff *list = ((struct sk_buff *)list_)->prev;
+ if (list == (struct sk_buff *)list_)
+ list = NULL;
+ return list;
+}
+
+/**
+ * skb_queue_len - get queue length
+ * @list_: list to measure
+ *
+ * Return the length of an &sk_buff queue.
+ */
+static inline __u32 skb_queue_len(const struct sk_buff_head *list_)
+{
+ return list_->qlen;
+}
+
+static inline void skb_queue_head_init(struct sk_buff_head *list)
+{
+ spin_lock_init(&list->lock);
+ list->prev = list->next = (struct sk_buff *)list;
+ list->qlen = 0;
+}
+
+/*
+ * Insert an sk_buff at the start of a list.
+ *
+ * The "__skb_xxxx()" functions are the non-atomic ones that
+ * can only be called with interrupts disabled.
+ */
+
+/**
+ * __skb_queue_head - queue a buffer at the list head
+ * @list: list to use
+ * @newsk: buffer to queue
+ *
+ * Queue a buffer at the start of a list. This function takes no locks
+ * and you must therefore hold required locks before calling it.
+ *
+ * A buffer cannot be placed on two lists at the same time.
+ */
+extern void skb_queue_head(struct sk_buff_head *list, struct sk_buff *newsk);
+static inline void __skb_queue_head(struct sk_buff_head *list,
+ struct sk_buff *newsk)
+{
+ struct sk_buff *prev, *next;
+
+ newsk->list = list;
+ list->qlen++;
+ prev = (struct sk_buff *)list;
+ next = prev->next;
+ newsk->next = next;
+ newsk->prev = prev;
+ next->prev = prev->next = newsk;
+}
+
+/**
+ * __skb_queue_tail - queue a buffer at the list tail
+ * @list: list to use
+ * @newsk: buffer to queue
+ *
+ * Queue a buffer at the end of a list. This function takes no locks
+ * and you must therefore hold required locks before calling it.
+ *
+ * A buffer cannot be placed on two lists at the same time.
+ */
+extern void skb_queue_tail(struct sk_buff_head *list, struct sk_buff *newsk);
+static inline void __skb_queue_tail(struct sk_buff_head *list,
+ struct sk_buff *newsk)
+{
+ struct sk_buff *prev, *next;
+
+ newsk->list = list;
+ list->qlen++;
+ next = (struct sk_buff *)list;
+ prev = next->prev;
+ newsk->next = next;
+ newsk->prev = prev;
+ next->prev = prev->next = newsk;
+}
+
+
+/**
+ * __skb_dequeue - remove from the head of the queue
+ * @list: list to dequeue from
+ *
+ * Remove the head of the list. This function does not take any locks
+ * so must be used with appropriate locks held only. The head item is
+ * returned or %NULL if the list is empty.
+ */
+extern struct sk_buff *skb_dequeue(struct sk_buff_head *list);
+static inline struct sk_buff *__skb_dequeue(struct sk_buff_head *list)
+{
+ struct sk_buff *next, *prev, *result;
+
+ prev = (struct sk_buff *) list;
+ next = prev->next;
+ result = NULL;
+ if (next != prev) {
+ result = next;
+ next = next->next;
+ list->qlen--;
+ next->prev = prev;
+ prev->next = next;
+ result->next = result->prev = NULL;
+ result->list = NULL;
+ }
+ return result;
+}
+
+
+/*
+ * Insert a packet on a list.
+ */
+extern void skb_insert(struct sk_buff *old, struct sk_buff *newsk);
+static inline void __skb_insert(struct sk_buff *newsk,
+ struct sk_buff *prev, struct sk_buff *next,
+ struct sk_buff_head *list)
+{
+ newsk->next = next;
+ newsk->prev = prev;
+ next->prev = prev->next = newsk;
+ newsk->list = list;
+ list->qlen++;
+}
+
+/*
+ * Place a packet after a given packet in a list.
+ */
+extern void skb_append(struct sk_buff *old, struct sk_buff *newsk);
+static inline void __skb_append(struct sk_buff *old, struct sk_buff *newsk)
+{
+ __skb_insert(newsk, old, old->next, old->list);
+}
+
+/*
+ * remove sk_buff from list. _Must_ be called atomically, and with
+ * the list known..
+ */
+extern void skb_unlink(struct sk_buff *skb);
+static inline void __skb_unlink(struct sk_buff *skb, struct sk_buff_head *list)
+{
+ struct sk_buff *next, *prev;
+
+ list->qlen--;
+ next = skb->next;
+ prev = skb->prev;
+ skb->next = skb->prev = NULL;
+ skb->list = NULL;
+ next->prev = prev;
+ prev->next = next;
+}
+
+
+/* XXX: more streamlined implementation */
+
+/**
+ * __skb_dequeue_tail - remove from the tail of the queue
+ * @list: list to dequeue from
+ *
+ * Remove the tail of the list. This function does not take any locks
+ * so must be used with appropriate locks held only. The tail item is
+ * returned or %NULL if the list is empty.
+ */
+extern struct sk_buff *skb_dequeue_tail(struct sk_buff_head *list);
+static inline struct sk_buff *__skb_dequeue_tail(struct sk_buff_head *list)
+{
+ struct sk_buff *skb = skb_peek_tail(list);
+ if (skb)
+ __skb_unlink(skb, list);
+ return skb;
+}
+
+
+static inline int skb_is_nonlinear(const struct sk_buff *skb)
+{
+ return skb->data_len;
+}
+
+static inline unsigned int skb_headlen(const struct sk_buff *skb)
+{
+ return skb->len - skb->data_len;
+}
+
+static inline int skb_pagelen(const struct sk_buff *skb)
+{
+ int i, len = 0;
+
+ for (i = (int)skb_shinfo(skb)->nr_frags - 1; i >= 0; i--)
+ len += skb_shinfo(skb)->frags[i].size;
+ return len + skb_headlen(skb);
+}
+
+static inline void skb_fill_page_desc(struct sk_buff *skb, int i,
+ struct page *page, int off, int size)
+{
+ skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
+
+ frag->page = page;
+ frag->page_offset = off;
+ frag->size = size;
+ skb_shinfo(skb)->nr_frags = i + 1;
+}
+
+#define SKB_PAGE_ASSERT(skb) BUG_ON(skb_shinfo(skb)->nr_frags)
+#define SKB_FRAG_ASSERT(skb) BUG_ON(skb_shinfo(skb)->frag_list)
+#define SKB_LINEAR_ASSERT(skb) BUG_ON(skb_is_nonlinear(skb))
+
+/*
+ * Add data to an sk_buff
+ */
+static inline unsigned char *__skb_put(struct sk_buff *skb, unsigned int len)
+{
+ unsigned char *tmp = skb->tail;
+ SKB_LINEAR_ASSERT(skb);
+ skb->tail += len;
+ skb->len += len;
+ return tmp;
+}
+
+/**
+ * skb_put - add data to a buffer
+ * @skb: buffer to use
+ * @len: amount of data to add
+ *
+ * This function extends the used data area of the buffer. If this would
+ * exceed the total buffer size the kernel will panic. A pointer to the
+ * first byte of the extra data is returned.
+ */
+static inline unsigned char *skb_put(struct sk_buff *skb, unsigned int len)
+{
+ unsigned char *tmp = skb->tail;
+ SKB_LINEAR_ASSERT(skb);
+ skb->tail += len;
+ skb->len += len;
+ if (unlikely(skb->tail>skb->end))
+ skb_over_panic(skb, len, current_text_addr());
+ return tmp;
+}
+
+static inline unsigned char *__skb_push(struct sk_buff *skb, unsigned int len)
+{
+ skb->data -= len;
+ skb->len += len;
+ return skb->data;
+}
+
+/**
+ * skb_push - add data to the start of a buffer
+ * @skb: buffer to use
+ * @len: amount of data to add
+ *
+ * This function extends the used data area of the buffer at the buffer
+ * start. If this would exceed the total buffer headroom the kernel will
+ * panic. A pointer to the first byte of the extra data is returned.
+ */
+static inline unsigned char *skb_push(struct sk_buff *skb, unsigned int len)
+{
+ skb->data -= len;
+ skb->len += len;
+ if (unlikely(skb->data<skb->head))
+ skb_under_panic(skb, len, current_text_addr());
+ return skb->data;
+}
+
+static inline unsigned char *__skb_pull(struct sk_buff *skb, unsigned int len)
+{
+ skb->len -= len;
+ BUG_ON(skb->len < skb->data_len);
+ return skb->data += len;
+}
+
+/**
+ * skb_pull - remove data from the start of a buffer
+ * @skb: buffer to use
+ * @len: amount of data to remove
+ *
+ * This function removes data from the start of a buffer, returning
+ * the memory to the headroom. A pointer to the next data in the buffer
+ * is returned. Once the data has been pulled future pushes will overwrite
+ * the old data.
+ */
+static inline unsigned char *skb_pull(struct sk_buff *skb, unsigned int len)
+{
+ return unlikely(len > skb->len) ? NULL : __skb_pull(skb, len);
+}
+
+extern unsigned char *__pskb_pull_tail(struct sk_buff *skb, int delta);
+
+static inline unsigned char *__pskb_pull(struct sk_buff *skb, unsigned int len)
+{
+ if (len > skb_headlen(skb) &&
+ !__pskb_pull_tail(skb, len-skb_headlen(skb)))
+ return NULL;
+ skb->len -= len;
+ return skb->data += len;
+}
+
+static inline unsigned char *pskb_pull(struct sk_buff *skb, unsigned int len)
+{
+ return unlikely(len > skb->len) ? NULL : __pskb_pull(skb, len);
+}
+
+static inline int pskb_may_pull(struct sk_buff *skb, unsigned int len)
+{
+ if (likely(len <= skb_headlen(skb)))
+ return 1;
+ if (unlikely(len > skb->len))
+ return 0;
+ return __pskb_pull_tail(skb, len-skb_headlen(skb)) != NULL;
+}
+
+/**
+ * skb_headroom - bytes at buffer head
+ * @skb: buffer to check
+ *
+ * Return the number of bytes of free space at the head of an &sk_buff.
+ */
+static inline int skb_headroom(const struct sk_buff *skb)
+{
+ return skb->data - skb->head;
+}
+
+/**
+ * skb_tailroom - bytes at buffer end
+ * @skb: buffer to check
+ *
+ * Return the number of bytes of free space at the tail of an sk_buff
+ */
+static inline int skb_tailroom(const struct sk_buff *skb)
+{
+ return skb_is_nonlinear(skb) ? 0 : skb->end - skb->tail;
+}
+
+/**
+ * skb_reserve - adjust headroom
+ * @skb: buffer to alter
+ * @len: bytes to move
+ *
+ * Increase the headroom of an empty &sk_buff by reducing the tail
+ * room. This is only allowed for an empty buffer.
+ */
+static inline void skb_reserve(struct sk_buff *skb, unsigned int len)
+{
+ skb->data += len;
+ skb->tail += len;
+}
+
+/*
+ * CPUs often take a performance hit when accessing unaligned memory
+ * locations. The actual performance hit varies, it can be small if the
+ * hardware handles it or large if we have to take an exception and fix it
+ * in software.
+ *
+ * Since an ethernet header is 14 bytes network drivers often end up with
+ * the IP header at an unaligned offset. The IP header can be aligned by
+ * shifting the start of the packet by 2 bytes. Drivers should do this
+ * with:
+ *
+ * skb_reserve(NET_IP_ALIGN);
+ *
+ * The downside to this alignment of the IP header is that the DMA is now
+ * unaligned. On some architectures the cost of an unaligned DMA is high
+ * and this cost outweighs the gains made by aligning the IP header.
+ *
+ * Since this trade off varies between architectures, we allow NET_IP_ALIGN
+ * to be overridden.
+ */
+#ifndef NET_IP_ALIGN
+#define NET_IP_ALIGN 2
+#endif
+
+extern int ___pskb_trim(struct sk_buff *skb, unsigned int len, int realloc);
+
+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);
+}
+
+/**
+ * skb_trim - remove end from a buffer
+ * @skb: buffer to alter
+ * @len: new length
+ *
+ * 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.
+ */
+static inline void skb_trim(struct sk_buff *skb, unsigned int len)
+{
+ if (skb->len > len)
+ __skb_trim(skb, 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);
+}
+
+static inline int pskb_trim(struct sk_buff *skb, unsigned int len)
+{
+ return (len < skb->len) ? __pskb_trim(skb, len) : 0;
+}
+
+/**
+ * skb_orphan - orphan a buffer
+ * @skb: buffer to orphan
+ *
+ * If a buffer currently has an owner then we call the owner's
+ * destructor function and make the @skb unowned. The buffer continues
+ * to exist but is no longer charged to its former owner.
+ */
+static inline void skb_orphan(struct sk_buff *skb)
+{
+ if (skb->destructor)
+ skb->destructor(skb);
+ skb->destructor = NULL;
+ skb->sk = NULL;
+}
+
+/**
+ * __skb_queue_purge - empty a list
+ * @list: list to empty
+ *
+ * Delete all buffers on an &sk_buff list. Each buffer is removed from
+ * the list and one reference dropped. This function does not take the
+ * list lock and the caller must hold the relevant locks to use it.
+ */
+extern void skb_queue_purge(struct sk_buff_head *list);
+static inline void __skb_queue_purge(struct sk_buff_head *list)
+{
+ struct sk_buff *skb;
+ while ((skb = __skb_dequeue(list)) != NULL)
+ kfree_skb(skb);
+}
+
+/**
+ * __dev_alloc_skb - allocate an skbuff for sending
+ * @length: length to allocate
+ * @gfp_mask: get_free_pages mask, passed to alloc_skb
+ *
+ * Allocate a new &sk_buff and assign it a usage count of one. The
+ * buffer has unspecified headroom built in. Users should allocate
+ * the headroom they think they need without accounting for the
+ * built in space. The built in space is used for optimisations.
+ *
+ * %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)
+{
+ struct sk_buff *skb = alloc_skb(length + 16, gfp_mask);
+ if (likely(skb))
+ skb_reserve(skb, 16);
+ return skb;
+}
+#else
+extern struct sk_buff *__dev_alloc_skb(unsigned int length, int gfp_mask);
+#endif
+
+/**
+ * dev_alloc_skb - allocate an skbuff for sending
+ * @length: length to allocate
+ *
+ * Allocate a new &sk_buff and assign it a usage count of one. The
+ * buffer has unspecified headroom built in. Users should allocate
+ * the headroom they think they need without accounting for the
+ * built in space. The built in space is used for optimisations.
+ *
+ * %NULL is returned in there is no free memory. Although this function
+ * allocates memory it can be called from an interrupt.
+ */
+static inline struct sk_buff *dev_alloc_skb(unsigned int length)
+{
+ return __dev_alloc_skb(length, GFP_ATOMIC);
+}
+
+/**
+ * skb_cow - copy header of skb when it is required
+ * @skb: buffer to cow
+ * @headroom: needed headroom
+ *
+ * If the skb passed lacks sufficient headroom or its data part
+ * is shared, data is reallocated. If reallocation fails, an error
+ * is returned and original skb is not changed.
+ *
+ * The result is skb with writable area skb->head...skb->tail
+ * and at least @headroom of space at head.
+ */
+static inline int skb_cow(struct sk_buff *skb, unsigned int headroom)
+{
+ int delta = (headroom > 16 ? headroom : 16) - 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 0;
+}
+
+/**
+ * skb_padto - pad an skbuff up to a minimal size
+ * @skb: buffer to pad
+ * @len: minimal length
+ *
+ * Pads up a buffer to ensure the trailing bytes exist and are
+ * blanked. If the buffer already contains sufficient data it
+ * is untouched. Returns the buffer, which may be a replacement
+ * for the original, or NULL for out of memory - in which case
+ * the original buffer is still freed.
+ */
+
+static inline struct sk_buff *skb_padto(struct sk_buff *skb, unsigned int len)
+{
+ unsigned int size = skb->len;
+ if (likely(size >= len))
+ return skb;
+ return skb_pad(skb, len-size);
+}
+
+static inline int skb_add_data(struct sk_buff *skb,
+ char __user *from, int copy)
+{
+ const int off = skb->len;
+
+ if (skb->ip_summed == CHECKSUM_NONE) {
+ int err = 0;
+ unsigned int csum = csum_and_copy_from_user(from,
+ skb_put(skb, copy),
+ copy, 0, &err);
+ if (!err) {
+ skb->csum = csum_block_add(skb->csum, csum, off);
+ return 0;
+ }
+ } else if (!copy_from_user(skb_put(skb, copy), from, copy))
+ return 0;
+
+ __skb_trim(skb, off);
+ return -EFAULT;
+}
+
+static inline int skb_can_coalesce(struct sk_buff *skb, int i,
+ struct page *page, int off)
+{
+ if (i) {
+ struct skb_frag_struct *frag = &skb_shinfo(skb)->frags[i - 1];
+
+ return page == frag->page &&
+ off == frag->page_offset + frag->size;
+ }
+ return 0;
+}
+
+/**
+ * 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, int gfp);
+static inline int skb_linearize(struct sk_buff *skb, int gfp)
+{
+ 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
+ BUG_ON(in_irq());
+
+ local_bh_disable();
+#endif
+ return kmap_atomic(frag->page, KM_SKB_DATA_SOFTIRQ);
+}
+
+static inline void kunmap_skb_frag(void *vaddr)
+{
+ kunmap_atomic(vaddr, KM_SKB_DATA_SOFTIRQ);
+#ifdef CONFIG_HIGHMEM
+ local_bh_enable();
+#endif
+}
+
+#define skb_queue_walk(queue, skb) \
+ for (skb = (queue)->next; \
+ prefetch(skb->next), (skb != (struct sk_buff *)(queue)); \
+ skb = skb->next)
+
+
+extern struct sk_buff *skb_recv_datagram(struct sock *sk, unsigned flags,
+ int noblock, int *err);
+extern unsigned int datagram_poll(struct file *file, struct socket *sock,
+ struct poll_table_struct *wait);
+extern int skb_copy_datagram_iovec(const struct sk_buff *from,
+ int offset, struct iovec *to,
+ int size);
+extern int skb_copy_and_csum_datagram_iovec(const
+ struct sk_buff *skb,
+ int hlen,
+ struct iovec *iov);
+extern void skb_free_datagram(struct sock *sk, struct sk_buff *skb);
+extern unsigned int skb_checksum(const struct sk_buff *skb, int offset,
+ int len, unsigned int csum);
+extern int skb_copy_bits(const struct sk_buff *skb, int offset,
+ void *to, 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_copy_and_csum_dev(const struct sk_buff *skb, u8 *to);
+extern void skb_split(struct sk_buff *skb,
+ struct sk_buff *skb1, const u32 len);
+
+static inline void *skb_header_pointer(const struct sk_buff *skb, int offset,
+ int len, void *buffer)
+{
+ int hlen = skb_headlen(skb);
+
+ if (offset + len <= hlen)
+ return skb->data + offset;
+
+ if (skb_copy_bits(skb, offset, buffer, len) < 0)
+ return NULL;
+
+ return buffer;
+}
+
+extern void skb_init(void);
+extern void skb_add_mtu(int mtu);
+
+#ifdef CONFIG_NETFILTER
+static inline void nf_conntrack_put(struct nf_conntrack *nfct)
+{
+ if (nfct && atomic_dec_and_test(&nfct->use))
+ nfct->destroy(nfct);
+}
+static inline void nf_conntrack_get(struct nf_conntrack *nfct)
+{
+ if (nfct)
+ atomic_inc(&nfct->use);
+}
+static inline void nf_reset(struct sk_buff *skb)
+{
+ nf_conntrack_put(skb->nfct);
+ skb->nfct = NULL;
+#ifdef CONFIG_NETFILTER_DEBUG
+ skb->nf_debug = 0;
+#endif
+}
+static inline void nf_reset_debug(struct sk_buff *skb)
+{
+#ifdef CONFIG_NETFILTER_DEBUG
+ skb->nf_debug = 0;
+#endif
+}
+
+#ifdef CONFIG_BRIDGE_NETFILTER
+static inline void nf_bridge_put(struct nf_bridge_info *nf_bridge)
+{
+ if (nf_bridge && atomic_dec_and_test(&nf_bridge->use))
+ kfree(nf_bridge);
+}
+static inline void nf_bridge_get(struct nf_bridge_info *nf_bridge)
+{
+ if (nf_bridge)
+ atomic_inc(&nf_bridge->use);
+}
+#endif /* CONFIG_BRIDGE_NETFILTER */
+#else /* CONFIG_NETFILTER */
+static inline void nf_reset(struct sk_buff *skb) {}
+#endif /* CONFIG_NETFILTER */
+
+#endif /* __KERNEL__ */
+#endif /* _LINUX_SKBUFF_H */