mirror of
https://github.com/torvalds/linux.git
synced 2024-11-16 09:02:00 +00:00
1da177e4c3
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!
1461 lines
35 KiB
C
1461 lines
35 KiB
C
/*
|
|
* Routines having to do with the 'struct sk_buff' memory handlers.
|
|
*
|
|
* Authors: Alan Cox <iiitac@pyr.swan.ac.uk>
|
|
* Florian La Roche <rzsfl@rz.uni-sb.de>
|
|
*
|
|
* Version: $Id: skbuff.c,v 1.90 2001/11/07 05:56:19 davem Exp $
|
|
*
|
|
* Fixes:
|
|
* Alan Cox : Fixed the worst of the load
|
|
* balancer bugs.
|
|
* Dave Platt : Interrupt stacking fix.
|
|
* Richard Kooijman : Timestamp fixes.
|
|
* Alan Cox : Changed buffer format.
|
|
* Alan Cox : destructor hook for AF_UNIX etc.
|
|
* Linus Torvalds : Better skb_clone.
|
|
* Alan Cox : Added skb_copy.
|
|
* Alan Cox : Added all the changed routines Linus
|
|
* only put in the headers
|
|
* Ray VanTassle : Fixed --skb->lock in free
|
|
* Alan Cox : skb_copy copy arp field
|
|
* Andi Kleen : slabified it.
|
|
* Robert Olsson : Removed skb_head_pool
|
|
*
|
|
* NOTE:
|
|
* The __skb_ routines should be called with interrupts
|
|
* disabled, or you better be *real* sure that the operation is atomic
|
|
* with respect to whatever list is being frobbed (e.g. via lock_sock()
|
|
* or via disabling bottom half handlers, etc).
|
|
*
|
|
* 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.
|
|
*/
|
|
|
|
/*
|
|
* The functions in this file will not compile correctly with gcc 2.4.x
|
|
*/
|
|
|
|
#include <linux/config.h>
|
|
#include <linux/module.h>
|
|
#include <linux/types.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/sched.h>
|
|
#include <linux/mm.h>
|
|
#include <linux/interrupt.h>
|
|
#include <linux/in.h>
|
|
#include <linux/inet.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/netdevice.h>
|
|
#ifdef CONFIG_NET_CLS_ACT
|
|
#include <net/pkt_sched.h>
|
|
#endif
|
|
#include <linux/string.h>
|
|
#include <linux/skbuff.h>
|
|
#include <linux/cache.h>
|
|
#include <linux/rtnetlink.h>
|
|
#include <linux/init.h>
|
|
#include <linux/highmem.h>
|
|
|
|
#include <net/protocol.h>
|
|
#include <net/dst.h>
|
|
#include <net/sock.h>
|
|
#include <net/checksum.h>
|
|
#include <net/xfrm.h>
|
|
|
|
#include <asm/uaccess.h>
|
|
#include <asm/system.h>
|
|
|
|
static kmem_cache_t *skbuff_head_cache;
|
|
|
|
/*
|
|
* Keep out-of-line to prevent kernel bloat.
|
|
* __builtin_return_address is not used because it is not always
|
|
* reliable.
|
|
*/
|
|
|
|
/**
|
|
* skb_over_panic - private function
|
|
* @skb: buffer
|
|
* @sz: size
|
|
* @here: address
|
|
*
|
|
* Out of line support code for skb_put(). Not user callable.
|
|
*/
|
|
void skb_over_panic(struct sk_buff *skb, int sz, void *here)
|
|
{
|
|
printk(KERN_INFO "skput:over: %p:%d put:%d dev:%s",
|
|
here, skb->len, sz, skb->dev ? skb->dev->name : "<NULL>");
|
|
BUG();
|
|
}
|
|
|
|
/**
|
|
* skb_under_panic - private function
|
|
* @skb: buffer
|
|
* @sz: size
|
|
* @here: address
|
|
*
|
|
* Out of line support code for skb_push(). Not user callable.
|
|
*/
|
|
|
|
void skb_under_panic(struct sk_buff *skb, int sz, void *here)
|
|
{
|
|
printk(KERN_INFO "skput:under: %p:%d put:%d dev:%s",
|
|
here, skb->len, sz, skb->dev ? skb->dev->name : "<NULL>");
|
|
BUG();
|
|
}
|
|
|
|
/* Allocate a new skbuff. We do this ourselves so we can fill in a few
|
|
* 'private' fields and also do memory statistics to find all the
|
|
* [BEEP] leaks.
|
|
*
|
|
*/
|
|
|
|
/**
|
|
* alloc_skb - allocate a network buffer
|
|
* @size: size to allocate
|
|
* @gfp_mask: allocation mask
|
|
*
|
|
* Allocate a new &sk_buff. The returned buffer has no headroom and a
|
|
* tail room of size bytes. The object has a reference count of one.
|
|
* The return is the buffer. On a failure the return is %NULL.
|
|
*
|
|
* Buffers may only be allocated from interrupts using a @gfp_mask of
|
|
* %GFP_ATOMIC.
|
|
*/
|
|
struct sk_buff *alloc_skb(unsigned int size, int gfp_mask)
|
|
{
|
|
struct sk_buff *skb;
|
|
u8 *data;
|
|
|
|
/* Get the HEAD */
|
|
skb = kmem_cache_alloc(skbuff_head_cache,
|
|
gfp_mask & ~__GFP_DMA);
|
|
if (!skb)
|
|
goto out;
|
|
|
|
/* Get the DATA. Size must match skb_add_mtu(). */
|
|
size = SKB_DATA_ALIGN(size);
|
|
data = kmalloc(size + sizeof(struct skb_shared_info), gfp_mask);
|
|
if (!data)
|
|
goto nodata;
|
|
|
|
memset(skb, 0, offsetof(struct sk_buff, truesize));
|
|
skb->truesize = size + sizeof(struct sk_buff);
|
|
atomic_set(&skb->users, 1);
|
|
skb->head = data;
|
|
skb->data = data;
|
|
skb->tail = data;
|
|
skb->end = data + size;
|
|
|
|
atomic_set(&(skb_shinfo(skb)->dataref), 1);
|
|
skb_shinfo(skb)->nr_frags = 0;
|
|
skb_shinfo(skb)->tso_size = 0;
|
|
skb_shinfo(skb)->tso_segs = 0;
|
|
skb_shinfo(skb)->frag_list = NULL;
|
|
out:
|
|
return skb;
|
|
nodata:
|
|
kmem_cache_free(skbuff_head_cache, skb);
|
|
skb = NULL;
|
|
goto out;
|
|
}
|
|
|
|
/**
|
|
* alloc_skb_from_cache - allocate a network buffer
|
|
* @cp: kmem_cache from which to allocate the data area
|
|
* (object size must be big enough for @size bytes + skb overheads)
|
|
* @size: size to allocate
|
|
* @gfp_mask: allocation mask
|
|
*
|
|
* Allocate a new &sk_buff. The returned buffer has no headroom and
|
|
* tail room of size bytes. The object has a reference count of one.
|
|
* The return is the buffer. On a failure the return is %NULL.
|
|
*
|
|
* Buffers may only be allocated from interrupts using a @gfp_mask of
|
|
* %GFP_ATOMIC.
|
|
*/
|
|
struct sk_buff *alloc_skb_from_cache(kmem_cache_t *cp,
|
|
unsigned int size, int gfp_mask)
|
|
{
|
|
struct sk_buff *skb;
|
|
u8 *data;
|
|
|
|
/* Get the HEAD */
|
|
skb = kmem_cache_alloc(skbuff_head_cache,
|
|
gfp_mask & ~__GFP_DMA);
|
|
if (!skb)
|
|
goto out;
|
|
|
|
/* Get the DATA. */
|
|
size = SKB_DATA_ALIGN(size);
|
|
data = kmem_cache_alloc(cp, gfp_mask);
|
|
if (!data)
|
|
goto nodata;
|
|
|
|
memset(skb, 0, offsetof(struct sk_buff, truesize));
|
|
skb->truesize = size + sizeof(struct sk_buff);
|
|
atomic_set(&skb->users, 1);
|
|
skb->head = data;
|
|
skb->data = data;
|
|
skb->tail = data;
|
|
skb->end = data + size;
|
|
|
|
atomic_set(&(skb_shinfo(skb)->dataref), 1);
|
|
skb_shinfo(skb)->nr_frags = 0;
|
|
skb_shinfo(skb)->tso_size = 0;
|
|
skb_shinfo(skb)->tso_segs = 0;
|
|
skb_shinfo(skb)->frag_list = NULL;
|
|
out:
|
|
return skb;
|
|
nodata:
|
|
kmem_cache_free(skbuff_head_cache, skb);
|
|
skb = NULL;
|
|
goto out;
|
|
}
|
|
|
|
|
|
static void skb_drop_fraglist(struct sk_buff *skb)
|
|
{
|
|
struct sk_buff *list = skb_shinfo(skb)->frag_list;
|
|
|
|
skb_shinfo(skb)->frag_list = NULL;
|
|
|
|
do {
|
|
struct sk_buff *this = list;
|
|
list = list->next;
|
|
kfree_skb(this);
|
|
} while (list);
|
|
}
|
|
|
|
static void skb_clone_fraglist(struct sk_buff *skb)
|
|
{
|
|
struct sk_buff *list;
|
|
|
|
for (list = skb_shinfo(skb)->frag_list; list; list = list->next)
|
|
skb_get(list);
|
|
}
|
|
|
|
void skb_release_data(struct sk_buff *skb)
|
|
{
|
|
if (!skb->cloned ||
|
|
!atomic_sub_return(skb->nohdr ? (1 << SKB_DATAREF_SHIFT) + 1 : 1,
|
|
&skb_shinfo(skb)->dataref)) {
|
|
if (skb_shinfo(skb)->nr_frags) {
|
|
int i;
|
|
for (i = 0; i < skb_shinfo(skb)->nr_frags; i++)
|
|
put_page(skb_shinfo(skb)->frags[i].page);
|
|
}
|
|
|
|
if (skb_shinfo(skb)->frag_list)
|
|
skb_drop_fraglist(skb);
|
|
|
|
kfree(skb->head);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Free an skbuff by memory without cleaning the state.
|
|
*/
|
|
void kfree_skbmem(struct sk_buff *skb)
|
|
{
|
|
skb_release_data(skb);
|
|
kmem_cache_free(skbuff_head_cache, skb);
|
|
}
|
|
|
|
/**
|
|
* __kfree_skb - private function
|
|
* @skb: buffer
|
|
*
|
|
* Free an sk_buff. Release anything attached to the buffer.
|
|
* Clean the state. This is an internal helper function. Users should
|
|
* always call kfree_skb
|
|
*/
|
|
|
|
void __kfree_skb(struct sk_buff *skb)
|
|
{
|
|
if (skb->list) {
|
|
printk(KERN_WARNING "Warning: kfree_skb passed an skb still "
|
|
"on a list (from %p).\n", NET_CALLER(skb));
|
|
BUG();
|
|
}
|
|
|
|
dst_release(skb->dst);
|
|
#ifdef CONFIG_XFRM
|
|
secpath_put(skb->sp);
|
|
#endif
|
|
if(skb->destructor) {
|
|
if (in_irq())
|
|
printk(KERN_WARNING "Warning: kfree_skb on "
|
|
"hard IRQ %p\n", NET_CALLER(skb));
|
|
skb->destructor(skb);
|
|
}
|
|
#ifdef CONFIG_NETFILTER
|
|
nf_conntrack_put(skb->nfct);
|
|
#ifdef CONFIG_BRIDGE_NETFILTER
|
|
nf_bridge_put(skb->nf_bridge);
|
|
#endif
|
|
#endif
|
|
/* XXX: IS this still necessary? - JHS */
|
|
#ifdef CONFIG_NET_SCHED
|
|
skb->tc_index = 0;
|
|
#ifdef CONFIG_NET_CLS_ACT
|
|
skb->tc_verd = 0;
|
|
skb->tc_classid = 0;
|
|
#endif
|
|
#endif
|
|
|
|
kfree_skbmem(skb);
|
|
}
|
|
|
|
/**
|
|
* skb_clone - duplicate an sk_buff
|
|
* @skb: buffer to clone
|
|
* @gfp_mask: allocation priority
|
|
*
|
|
* Duplicate an &sk_buff. The new one is not owned by a socket. Both
|
|
* copies share the same packet data but not structure. The new
|
|
* buffer has a reference count of 1. If the allocation fails the
|
|
* function returns %NULL otherwise the new buffer is returned.
|
|
*
|
|
* If this function is called from an interrupt gfp_mask() must be
|
|
* %GFP_ATOMIC.
|
|
*/
|
|
|
|
struct sk_buff *skb_clone(struct sk_buff *skb, int gfp_mask)
|
|
{
|
|
struct sk_buff *n = kmem_cache_alloc(skbuff_head_cache, gfp_mask);
|
|
|
|
if (!n)
|
|
return NULL;
|
|
|
|
#define C(x) n->x = skb->x
|
|
|
|
n->next = n->prev = NULL;
|
|
n->list = NULL;
|
|
n->sk = NULL;
|
|
C(stamp);
|
|
C(dev);
|
|
C(real_dev);
|
|
C(h);
|
|
C(nh);
|
|
C(mac);
|
|
C(dst);
|
|
dst_clone(skb->dst);
|
|
C(sp);
|
|
#ifdef CONFIG_INET
|
|
secpath_get(skb->sp);
|
|
#endif
|
|
memcpy(n->cb, skb->cb, sizeof(skb->cb));
|
|
C(len);
|
|
C(data_len);
|
|
C(csum);
|
|
C(local_df);
|
|
n->cloned = 1;
|
|
n->nohdr = 0;
|
|
C(pkt_type);
|
|
C(ip_summed);
|
|
C(priority);
|
|
C(protocol);
|
|
C(security);
|
|
n->destructor = NULL;
|
|
#ifdef CONFIG_NETFILTER
|
|
C(nfmark);
|
|
C(nfcache);
|
|
C(nfct);
|
|
nf_conntrack_get(skb->nfct);
|
|
C(nfctinfo);
|
|
#ifdef CONFIG_NETFILTER_DEBUG
|
|
C(nf_debug);
|
|
#endif
|
|
#ifdef CONFIG_BRIDGE_NETFILTER
|
|
C(nf_bridge);
|
|
nf_bridge_get(skb->nf_bridge);
|
|
#endif
|
|
#endif /*CONFIG_NETFILTER*/
|
|
#if defined(CONFIG_HIPPI)
|
|
C(private);
|
|
#endif
|
|
#ifdef CONFIG_NET_SCHED
|
|
C(tc_index);
|
|
#ifdef CONFIG_NET_CLS_ACT
|
|
n->tc_verd = SET_TC_VERD(skb->tc_verd,0);
|
|
n->tc_verd = CLR_TC_OK2MUNGE(skb->tc_verd);
|
|
n->tc_verd = CLR_TC_MUNGED(skb->tc_verd);
|
|
C(input_dev);
|
|
C(tc_classid);
|
|
#endif
|
|
|
|
#endif
|
|
C(truesize);
|
|
atomic_set(&n->users, 1);
|
|
C(head);
|
|
C(data);
|
|
C(tail);
|
|
C(end);
|
|
|
|
atomic_inc(&(skb_shinfo(skb)->dataref));
|
|
skb->cloned = 1;
|
|
|
|
return n;
|
|
}
|
|
|
|
static void copy_skb_header(struct sk_buff *new, const struct sk_buff *old)
|
|
{
|
|
/*
|
|
* Shift between the two data areas in bytes
|
|
*/
|
|
unsigned long offset = new->data - old->data;
|
|
|
|
new->list = NULL;
|
|
new->sk = NULL;
|
|
new->dev = old->dev;
|
|
new->real_dev = old->real_dev;
|
|
new->priority = old->priority;
|
|
new->protocol = old->protocol;
|
|
new->dst = dst_clone(old->dst);
|
|
#ifdef CONFIG_INET
|
|
new->sp = secpath_get(old->sp);
|
|
#endif
|
|
new->h.raw = old->h.raw + offset;
|
|
new->nh.raw = old->nh.raw + offset;
|
|
new->mac.raw = old->mac.raw + offset;
|
|
memcpy(new->cb, old->cb, sizeof(old->cb));
|
|
new->local_df = old->local_df;
|
|
new->pkt_type = old->pkt_type;
|
|
new->stamp = old->stamp;
|
|
new->destructor = NULL;
|
|
new->security = old->security;
|
|
#ifdef CONFIG_NETFILTER
|
|
new->nfmark = old->nfmark;
|
|
new->nfcache = old->nfcache;
|
|
new->nfct = old->nfct;
|
|
nf_conntrack_get(old->nfct);
|
|
new->nfctinfo = old->nfctinfo;
|
|
#ifdef CONFIG_NETFILTER_DEBUG
|
|
new->nf_debug = old->nf_debug;
|
|
#endif
|
|
#ifdef CONFIG_BRIDGE_NETFILTER
|
|
new->nf_bridge = old->nf_bridge;
|
|
nf_bridge_get(old->nf_bridge);
|
|
#endif
|
|
#endif
|
|
#ifdef CONFIG_NET_SCHED
|
|
#ifdef CONFIG_NET_CLS_ACT
|
|
new->tc_verd = old->tc_verd;
|
|
#endif
|
|
new->tc_index = old->tc_index;
|
|
#endif
|
|
atomic_set(&new->users, 1);
|
|
skb_shinfo(new)->tso_size = skb_shinfo(old)->tso_size;
|
|
skb_shinfo(new)->tso_segs = skb_shinfo(old)->tso_segs;
|
|
}
|
|
|
|
/**
|
|
* skb_copy - create private copy of an sk_buff
|
|
* @skb: buffer to copy
|
|
* @gfp_mask: allocation priority
|
|
*
|
|
* Make a copy of both an &sk_buff and its data. This is used when the
|
|
* caller wishes to modify the data and needs a private copy of the
|
|
* data to alter. Returns %NULL on failure or the pointer to the buffer
|
|
* on success. The returned buffer has a reference count of 1.
|
|
*
|
|
* As by-product this function converts non-linear &sk_buff to linear
|
|
* one, so that &sk_buff becomes completely private and caller is allowed
|
|
* to modify all the data of returned buffer. This means that this
|
|
* function is not recommended for use in circumstances when only
|
|
* header is going to be modified. Use pskb_copy() instead.
|
|
*/
|
|
|
|
struct sk_buff *skb_copy(const struct sk_buff *skb, int gfp_mask)
|
|
{
|
|
int headerlen = skb->data - skb->head;
|
|
/*
|
|
* Allocate the copy buffer
|
|
*/
|
|
struct sk_buff *n = alloc_skb(skb->end - skb->head + skb->data_len,
|
|
gfp_mask);
|
|
if (!n)
|
|
return NULL;
|
|
|
|
/* Set the data pointer */
|
|
skb_reserve(n, headerlen);
|
|
/* Set the tail pointer and length */
|
|
skb_put(n, skb->len);
|
|
n->csum = skb->csum;
|
|
n->ip_summed = skb->ip_summed;
|
|
|
|
if (skb_copy_bits(skb, -headerlen, n->head, headerlen + skb->len))
|
|
BUG();
|
|
|
|
copy_skb_header(n, skb);
|
|
return n;
|
|
}
|
|
|
|
|
|
/**
|
|
* pskb_copy - create copy of an sk_buff with private head.
|
|
* @skb: buffer to copy
|
|
* @gfp_mask: allocation priority
|
|
*
|
|
* Make a copy of both an &sk_buff and part of its data, located
|
|
* in header. Fragmented data remain shared. This is used when
|
|
* the caller wishes to modify only header of &sk_buff and needs
|
|
* private copy of the header to alter. Returns %NULL on failure
|
|
* or the pointer to the buffer on success.
|
|
* The returned buffer has a reference count of 1.
|
|
*/
|
|
|
|
struct sk_buff *pskb_copy(struct sk_buff *skb, int gfp_mask)
|
|
{
|
|
/*
|
|
* Allocate the copy buffer
|
|
*/
|
|
struct sk_buff *n = alloc_skb(skb->end - skb->head, gfp_mask);
|
|
|
|
if (!n)
|
|
goto out;
|
|
|
|
/* Set the data pointer */
|
|
skb_reserve(n, skb->data - skb->head);
|
|
/* Set the tail pointer and length */
|
|
skb_put(n, skb_headlen(skb));
|
|
/* Copy the bytes */
|
|
memcpy(n->data, skb->data, n->len);
|
|
n->csum = skb->csum;
|
|
n->ip_summed = skb->ip_summed;
|
|
|
|
n->data_len = skb->data_len;
|
|
n->len = skb->len;
|
|
|
|
if (skb_shinfo(skb)->nr_frags) {
|
|
int i;
|
|
|
|
for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
|
|
skb_shinfo(n)->frags[i] = skb_shinfo(skb)->frags[i];
|
|
get_page(skb_shinfo(n)->frags[i].page);
|
|
}
|
|
skb_shinfo(n)->nr_frags = i;
|
|
}
|
|
|
|
if (skb_shinfo(skb)->frag_list) {
|
|
skb_shinfo(n)->frag_list = skb_shinfo(skb)->frag_list;
|
|
skb_clone_fraglist(n);
|
|
}
|
|
|
|
copy_skb_header(n, skb);
|
|
out:
|
|
return n;
|
|
}
|
|
|
|
/**
|
|
* pskb_expand_head - reallocate header of &sk_buff
|
|
* @skb: buffer to reallocate
|
|
* @nhead: room to add at head
|
|
* @ntail: room to add at tail
|
|
* @gfp_mask: allocation priority
|
|
*
|
|
* Expands (or creates identical copy, if &nhead and &ntail are zero)
|
|
* header of skb. &sk_buff itself is not changed. &sk_buff MUST have
|
|
* reference count of 1. Returns zero in the case of success or error,
|
|
* if expansion failed. In the last case, &sk_buff is not changed.
|
|
*
|
|
* All the pointers pointing into skb header may change and must be
|
|
* reloaded after call to this function.
|
|
*/
|
|
|
|
int pskb_expand_head(struct sk_buff *skb, int nhead, int ntail, int gfp_mask)
|
|
{
|
|
int i;
|
|
u8 *data;
|
|
int size = nhead + (skb->end - skb->head) + ntail;
|
|
long off;
|
|
|
|
if (skb_shared(skb))
|
|
BUG();
|
|
|
|
size = SKB_DATA_ALIGN(size);
|
|
|
|
data = kmalloc(size + sizeof(struct skb_shared_info), gfp_mask);
|
|
if (!data)
|
|
goto nodata;
|
|
|
|
/* Copy only real data... and, alas, header. This should be
|
|
* optimized for the cases when header is void. */
|
|
memcpy(data + nhead, skb->head, skb->tail - skb->head);
|
|
memcpy(data + size, skb->end, sizeof(struct skb_shared_info));
|
|
|
|
for (i = 0; i < skb_shinfo(skb)->nr_frags; i++)
|
|
get_page(skb_shinfo(skb)->frags[i].page);
|
|
|
|
if (skb_shinfo(skb)->frag_list)
|
|
skb_clone_fraglist(skb);
|
|
|
|
skb_release_data(skb);
|
|
|
|
off = (data + nhead) - skb->head;
|
|
|
|
skb->head = data;
|
|
skb->end = data + size;
|
|
skb->data += off;
|
|
skb->tail += off;
|
|
skb->mac.raw += off;
|
|
skb->h.raw += off;
|
|
skb->nh.raw += off;
|
|
skb->cloned = 0;
|
|
skb->nohdr = 0;
|
|
atomic_set(&skb_shinfo(skb)->dataref, 1);
|
|
return 0;
|
|
|
|
nodata:
|
|
return -ENOMEM;
|
|
}
|
|
|
|
/* Make private copy of skb with writable head and some headroom */
|
|
|
|
struct sk_buff *skb_realloc_headroom(struct sk_buff *skb, unsigned int headroom)
|
|
{
|
|
struct sk_buff *skb2;
|
|
int delta = headroom - skb_headroom(skb);
|
|
|
|
if (delta <= 0)
|
|
skb2 = pskb_copy(skb, GFP_ATOMIC);
|
|
else {
|
|
skb2 = skb_clone(skb, GFP_ATOMIC);
|
|
if (skb2 && pskb_expand_head(skb2, SKB_DATA_ALIGN(delta), 0,
|
|
GFP_ATOMIC)) {
|
|
kfree_skb(skb2);
|
|
skb2 = NULL;
|
|
}
|
|
}
|
|
return skb2;
|
|
}
|
|
|
|
|
|
/**
|
|
* skb_copy_expand - copy and expand sk_buff
|
|
* @skb: buffer to copy
|
|
* @newheadroom: new free bytes at head
|
|
* @newtailroom: new free bytes at tail
|
|
* @gfp_mask: allocation priority
|
|
*
|
|
* Make a copy of both an &sk_buff and its data and while doing so
|
|
* allocate additional space.
|
|
*
|
|
* This is used when the caller wishes to modify the data and needs a
|
|
* private copy of the data to alter as well as more space for new fields.
|
|
* Returns %NULL on failure or the pointer to the buffer
|
|
* on success. The returned buffer has a reference count of 1.
|
|
*
|
|
* You must pass %GFP_ATOMIC as the allocation priority if this function
|
|
* is called from an interrupt.
|
|
*
|
|
* BUG ALERT: ip_summed is not copied. Why does this work? Is it used
|
|
* only by netfilter in the cases when checksum is recalculated? --ANK
|
|
*/
|
|
struct sk_buff *skb_copy_expand(const struct sk_buff *skb,
|
|
int newheadroom, int newtailroom, int gfp_mask)
|
|
{
|
|
/*
|
|
* Allocate the copy buffer
|
|
*/
|
|
struct sk_buff *n = alloc_skb(newheadroom + skb->len + newtailroom,
|
|
gfp_mask);
|
|
int head_copy_len, head_copy_off;
|
|
|
|
if (!n)
|
|
return NULL;
|
|
|
|
skb_reserve(n, newheadroom);
|
|
|
|
/* Set the tail pointer and length */
|
|
skb_put(n, skb->len);
|
|
|
|
head_copy_len = skb_headroom(skb);
|
|
head_copy_off = 0;
|
|
if (newheadroom <= head_copy_len)
|
|
head_copy_len = newheadroom;
|
|
else
|
|
head_copy_off = newheadroom - head_copy_len;
|
|
|
|
/* Copy the linear header and data. */
|
|
if (skb_copy_bits(skb, -head_copy_len, n->head + head_copy_off,
|
|
skb->len + head_copy_len))
|
|
BUG();
|
|
|
|
copy_skb_header(n, skb);
|
|
|
|
return n;
|
|
}
|
|
|
|
/**
|
|
* skb_pad - zero pad the tail of an skb
|
|
* @skb: buffer to pad
|
|
* @pad: space to pad
|
|
*
|
|
* Ensure that a buffer is followed by a padding area that is zero
|
|
* filled. Used by network drivers which may DMA or transfer data
|
|
* beyond the buffer end onto the wire.
|
|
*
|
|
* May return NULL in out of memory cases.
|
|
*/
|
|
|
|
struct sk_buff *skb_pad(struct sk_buff *skb, int pad)
|
|
{
|
|
struct sk_buff *nskb;
|
|
|
|
/* If the skbuff is non linear tailroom is always zero.. */
|
|
if (skb_tailroom(skb) >= pad) {
|
|
memset(skb->data+skb->len, 0, pad);
|
|
return skb;
|
|
}
|
|
|
|
nskb = skb_copy_expand(skb, skb_headroom(skb), skb_tailroom(skb) + pad, GFP_ATOMIC);
|
|
kfree_skb(skb);
|
|
if (nskb)
|
|
memset(nskb->data+nskb->len, 0, pad);
|
|
return nskb;
|
|
}
|
|
|
|
/* Trims skb to length len. It can change skb pointers, if "realloc" is 1.
|
|
* If realloc==0 and trimming is impossible without change of data,
|
|
* it is BUG().
|
|
*/
|
|
|
|
int ___pskb_trim(struct sk_buff *skb, unsigned int len, int realloc)
|
|
{
|
|
int offset = skb_headlen(skb);
|
|
int nfrags = skb_shinfo(skb)->nr_frags;
|
|
int i;
|
|
|
|
for (i = 0; i < nfrags; i++) {
|
|
int end = offset + skb_shinfo(skb)->frags[i].size;
|
|
if (end > len) {
|
|
if (skb_cloned(skb)) {
|
|
if (!realloc)
|
|
BUG();
|
|
if (pskb_expand_head(skb, 0, 0, GFP_ATOMIC))
|
|
return -ENOMEM;
|
|
}
|
|
if (len <= offset) {
|
|
put_page(skb_shinfo(skb)->frags[i].page);
|
|
skb_shinfo(skb)->nr_frags--;
|
|
} else {
|
|
skb_shinfo(skb)->frags[i].size = len - offset;
|
|
}
|
|
}
|
|
offset = end;
|
|
}
|
|
|
|
if (offset < len) {
|
|
skb->data_len -= skb->len - len;
|
|
skb->len = len;
|
|
} else {
|
|
if (len <= skb_headlen(skb)) {
|
|
skb->len = len;
|
|
skb->data_len = 0;
|
|
skb->tail = skb->data + len;
|
|
if (skb_shinfo(skb)->frag_list && !skb_cloned(skb))
|
|
skb_drop_fraglist(skb);
|
|
} else {
|
|
skb->data_len -= skb->len - len;
|
|
skb->len = len;
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* __pskb_pull_tail - advance tail of skb header
|
|
* @skb: buffer to reallocate
|
|
* @delta: number of bytes to advance tail
|
|
*
|
|
* The function makes a sense only on a fragmented &sk_buff,
|
|
* it expands header moving its tail forward and copying necessary
|
|
* data from fragmented part.
|
|
*
|
|
* &sk_buff MUST have reference count of 1.
|
|
*
|
|
* Returns %NULL (and &sk_buff does not change) if pull failed
|
|
* or value of new tail of skb in the case of success.
|
|
*
|
|
* All the pointers pointing into skb header may change and must be
|
|
* reloaded after call to this function.
|
|
*/
|
|
|
|
/* Moves tail of skb head forward, copying data from fragmented part,
|
|
* when it is necessary.
|
|
* 1. It may fail due to malloc failure.
|
|
* 2. It may change skb pointers.
|
|
*
|
|
* It is pretty complicated. Luckily, it is called only in exceptional cases.
|
|
*/
|
|
unsigned char *__pskb_pull_tail(struct sk_buff *skb, int delta)
|
|
{
|
|
/* If skb has not enough free space at tail, get new one
|
|
* plus 128 bytes for future expansions. If we have enough
|
|
* room at tail, reallocate without expansion only if skb is cloned.
|
|
*/
|
|
int i, k, eat = (skb->tail + delta) - skb->end;
|
|
|
|
if (eat > 0 || skb_cloned(skb)) {
|
|
if (pskb_expand_head(skb, 0, eat > 0 ? eat + 128 : 0,
|
|
GFP_ATOMIC))
|
|
return NULL;
|
|
}
|
|
|
|
if (skb_copy_bits(skb, skb_headlen(skb), skb->tail, delta))
|
|
BUG();
|
|
|
|
/* Optimization: no fragments, no reasons to preestimate
|
|
* size of pulled pages. Superb.
|
|
*/
|
|
if (!skb_shinfo(skb)->frag_list)
|
|
goto pull_pages;
|
|
|
|
/* Estimate size of pulled pages. */
|
|
eat = delta;
|
|
for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
|
|
if (skb_shinfo(skb)->frags[i].size >= eat)
|
|
goto pull_pages;
|
|
eat -= skb_shinfo(skb)->frags[i].size;
|
|
}
|
|
|
|
/* If we need update frag list, we are in troubles.
|
|
* Certainly, it possible to add an offset to skb data,
|
|
* but taking into account that pulling is expected to
|
|
* be very rare operation, it is worth to fight against
|
|
* further bloating skb head and crucify ourselves here instead.
|
|
* Pure masohism, indeed. 8)8)
|
|
*/
|
|
if (eat) {
|
|
struct sk_buff *list = skb_shinfo(skb)->frag_list;
|
|
struct sk_buff *clone = NULL;
|
|
struct sk_buff *insp = NULL;
|
|
|
|
do {
|
|
if (!list)
|
|
BUG();
|
|
|
|
if (list->len <= eat) {
|
|
/* Eaten as whole. */
|
|
eat -= list->len;
|
|
list = list->next;
|
|
insp = list;
|
|
} else {
|
|
/* Eaten partially. */
|
|
|
|
if (skb_shared(list)) {
|
|
/* Sucks! We need to fork list. :-( */
|
|
clone = skb_clone(list, GFP_ATOMIC);
|
|
if (!clone)
|
|
return NULL;
|
|
insp = list->next;
|
|
list = clone;
|
|
} else {
|
|
/* This may be pulled without
|
|
* problems. */
|
|
insp = list;
|
|
}
|
|
if (!pskb_pull(list, eat)) {
|
|
if (clone)
|
|
kfree_skb(clone);
|
|
return NULL;
|
|
}
|
|
break;
|
|
}
|
|
} while (eat);
|
|
|
|
/* Free pulled out fragments. */
|
|
while ((list = skb_shinfo(skb)->frag_list) != insp) {
|
|
skb_shinfo(skb)->frag_list = list->next;
|
|
kfree_skb(list);
|
|
}
|
|
/* And insert new clone at head. */
|
|
if (clone) {
|
|
clone->next = list;
|
|
skb_shinfo(skb)->frag_list = clone;
|
|
}
|
|
}
|
|
/* Success! Now we may commit changes to skb data. */
|
|
|
|
pull_pages:
|
|
eat = delta;
|
|
k = 0;
|
|
for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
|
|
if (skb_shinfo(skb)->frags[i].size <= eat) {
|
|
put_page(skb_shinfo(skb)->frags[i].page);
|
|
eat -= skb_shinfo(skb)->frags[i].size;
|
|
} else {
|
|
skb_shinfo(skb)->frags[k] = skb_shinfo(skb)->frags[i];
|
|
if (eat) {
|
|
skb_shinfo(skb)->frags[k].page_offset += eat;
|
|
skb_shinfo(skb)->frags[k].size -= eat;
|
|
eat = 0;
|
|
}
|
|
k++;
|
|
}
|
|
}
|
|
skb_shinfo(skb)->nr_frags = k;
|
|
|
|
skb->tail += delta;
|
|
skb->data_len -= delta;
|
|
|
|
return skb->tail;
|
|
}
|
|
|
|
/* Copy some data bits from skb to kernel buffer. */
|
|
|
|
int skb_copy_bits(const struct sk_buff *skb, int offset, void *to, int len)
|
|
{
|
|
int i, copy;
|
|
int start = skb_headlen(skb);
|
|
|
|
if (offset > (int)skb->len - len)
|
|
goto fault;
|
|
|
|
/* Copy header. */
|
|
if ((copy = start - offset) > 0) {
|
|
if (copy > len)
|
|
copy = len;
|
|
memcpy(to, skb->data + offset, copy);
|
|
if ((len -= copy) == 0)
|
|
return 0;
|
|
offset += copy;
|
|
to += copy;
|
|
}
|
|
|
|
for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
|
|
int end;
|
|
|
|
BUG_TRAP(start <= offset + len);
|
|
|
|
end = start + skb_shinfo(skb)->frags[i].size;
|
|
if ((copy = end - offset) > 0) {
|
|
u8 *vaddr;
|
|
|
|
if (copy > len)
|
|
copy = len;
|
|
|
|
vaddr = kmap_skb_frag(&skb_shinfo(skb)->frags[i]);
|
|
memcpy(to,
|
|
vaddr + skb_shinfo(skb)->frags[i].page_offset+
|
|
offset - start, copy);
|
|
kunmap_skb_frag(vaddr);
|
|
|
|
if ((len -= copy) == 0)
|
|
return 0;
|
|
offset += copy;
|
|
to += copy;
|
|
}
|
|
start = end;
|
|
}
|
|
|
|
if (skb_shinfo(skb)->frag_list) {
|
|
struct sk_buff *list = skb_shinfo(skb)->frag_list;
|
|
|
|
for (; list; list = list->next) {
|
|
int end;
|
|
|
|
BUG_TRAP(start <= offset + len);
|
|
|
|
end = start + list->len;
|
|
if ((copy = end - offset) > 0) {
|
|
if (copy > len)
|
|
copy = len;
|
|
if (skb_copy_bits(list, offset - start,
|
|
to, copy))
|
|
goto fault;
|
|
if ((len -= copy) == 0)
|
|
return 0;
|
|
offset += copy;
|
|
to += copy;
|
|
}
|
|
start = end;
|
|
}
|
|
}
|
|
if (!len)
|
|
return 0;
|
|
|
|
fault:
|
|
return -EFAULT;
|
|
}
|
|
|
|
/* Checksum skb data. */
|
|
|
|
unsigned int skb_checksum(const struct sk_buff *skb, int offset,
|
|
int len, unsigned int csum)
|
|
{
|
|
int start = skb_headlen(skb);
|
|
int i, copy = start - offset;
|
|
int pos = 0;
|
|
|
|
/* Checksum header. */
|
|
if (copy > 0) {
|
|
if (copy > len)
|
|
copy = len;
|
|
csum = csum_partial(skb->data + offset, copy, csum);
|
|
if ((len -= copy) == 0)
|
|
return csum;
|
|
offset += copy;
|
|
pos = copy;
|
|
}
|
|
|
|
for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
|
|
int end;
|
|
|
|
BUG_TRAP(start <= offset + len);
|
|
|
|
end = start + skb_shinfo(skb)->frags[i].size;
|
|
if ((copy = end - offset) > 0) {
|
|
unsigned int csum2;
|
|
u8 *vaddr;
|
|
skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
|
|
|
|
if (copy > len)
|
|
copy = len;
|
|
vaddr = kmap_skb_frag(frag);
|
|
csum2 = csum_partial(vaddr + frag->page_offset +
|
|
offset - start, copy, 0);
|
|
kunmap_skb_frag(vaddr);
|
|
csum = csum_block_add(csum, csum2, pos);
|
|
if (!(len -= copy))
|
|
return csum;
|
|
offset += copy;
|
|
pos += copy;
|
|
}
|
|
start = end;
|
|
}
|
|
|
|
if (skb_shinfo(skb)->frag_list) {
|
|
struct sk_buff *list = skb_shinfo(skb)->frag_list;
|
|
|
|
for (; list; list = list->next) {
|
|
int end;
|
|
|
|
BUG_TRAP(start <= offset + len);
|
|
|
|
end = start + list->len;
|
|
if ((copy = end - offset) > 0) {
|
|
unsigned int csum2;
|
|
if (copy > len)
|
|
copy = len;
|
|
csum2 = skb_checksum(list, offset - start,
|
|
copy, 0);
|
|
csum = csum_block_add(csum, csum2, pos);
|
|
if ((len -= copy) == 0)
|
|
return csum;
|
|
offset += copy;
|
|
pos += copy;
|
|
}
|
|
start = end;
|
|
}
|
|
}
|
|
if (len)
|
|
BUG();
|
|
|
|
return csum;
|
|
}
|
|
|
|
/* Both of above in one bottle. */
|
|
|
|
unsigned int skb_copy_and_csum_bits(const struct sk_buff *skb, int offset,
|
|
u8 *to, int len, unsigned int csum)
|
|
{
|
|
int start = skb_headlen(skb);
|
|
int i, copy = start - offset;
|
|
int pos = 0;
|
|
|
|
/* Copy header. */
|
|
if (copy > 0) {
|
|
if (copy > len)
|
|
copy = len;
|
|
csum = csum_partial_copy_nocheck(skb->data + offset, to,
|
|
copy, csum);
|
|
if ((len -= copy) == 0)
|
|
return csum;
|
|
offset += copy;
|
|
to += copy;
|
|
pos = copy;
|
|
}
|
|
|
|
for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
|
|
int end;
|
|
|
|
BUG_TRAP(start <= offset + len);
|
|
|
|
end = start + skb_shinfo(skb)->frags[i].size;
|
|
if ((copy = end - offset) > 0) {
|
|
unsigned int csum2;
|
|
u8 *vaddr;
|
|
skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
|
|
|
|
if (copy > len)
|
|
copy = len;
|
|
vaddr = kmap_skb_frag(frag);
|
|
csum2 = csum_partial_copy_nocheck(vaddr +
|
|
frag->page_offset +
|
|
offset - start, to,
|
|
copy, 0);
|
|
kunmap_skb_frag(vaddr);
|
|
csum = csum_block_add(csum, csum2, pos);
|
|
if (!(len -= copy))
|
|
return csum;
|
|
offset += copy;
|
|
to += copy;
|
|
pos += copy;
|
|
}
|
|
start = end;
|
|
}
|
|
|
|
if (skb_shinfo(skb)->frag_list) {
|
|
struct sk_buff *list = skb_shinfo(skb)->frag_list;
|
|
|
|
for (; list; list = list->next) {
|
|
unsigned int csum2;
|
|
int end;
|
|
|
|
BUG_TRAP(start <= offset + len);
|
|
|
|
end = start + list->len;
|
|
if ((copy = end - offset) > 0) {
|
|
if (copy > len)
|
|
copy = len;
|
|
csum2 = skb_copy_and_csum_bits(list,
|
|
offset - start,
|
|
to, copy, 0);
|
|
csum = csum_block_add(csum, csum2, pos);
|
|
if ((len -= copy) == 0)
|
|
return csum;
|
|
offset += copy;
|
|
to += copy;
|
|
pos += copy;
|
|
}
|
|
start = end;
|
|
}
|
|
}
|
|
if (len)
|
|
BUG();
|
|
return csum;
|
|
}
|
|
|
|
void skb_copy_and_csum_dev(const struct sk_buff *skb, u8 *to)
|
|
{
|
|
unsigned int csum;
|
|
long csstart;
|
|
|
|
if (skb->ip_summed == CHECKSUM_HW)
|
|
csstart = skb->h.raw - skb->data;
|
|
else
|
|
csstart = skb_headlen(skb);
|
|
|
|
if (csstart > skb_headlen(skb))
|
|
BUG();
|
|
|
|
memcpy(to, skb->data, csstart);
|
|
|
|
csum = 0;
|
|
if (csstart != skb->len)
|
|
csum = skb_copy_and_csum_bits(skb, csstart, to + csstart,
|
|
skb->len - csstart, 0);
|
|
|
|
if (skb->ip_summed == CHECKSUM_HW) {
|
|
long csstuff = csstart + skb->csum;
|
|
|
|
*((unsigned short *)(to + csstuff)) = csum_fold(csum);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* skb_dequeue - remove from the head of the queue
|
|
* @list: list to dequeue from
|
|
*
|
|
* Remove the head of the list. The list lock is taken so the function
|
|
* may be used safely with other locking list functions. The head item is
|
|
* returned or %NULL if the list is empty.
|
|
*/
|
|
|
|
struct sk_buff *skb_dequeue(struct sk_buff_head *list)
|
|
{
|
|
unsigned long flags;
|
|
struct sk_buff *result;
|
|
|
|
spin_lock_irqsave(&list->lock, flags);
|
|
result = __skb_dequeue(list);
|
|
spin_unlock_irqrestore(&list->lock, flags);
|
|
return result;
|
|
}
|
|
|
|
/**
|
|
* skb_dequeue_tail - remove from the tail of the queue
|
|
* @list: list to dequeue from
|
|
*
|
|
* Remove the tail of the list. The list lock is taken so the function
|
|
* may be used safely with other locking list functions. The tail item is
|
|
* returned or %NULL if the list is empty.
|
|
*/
|
|
struct sk_buff *skb_dequeue_tail(struct sk_buff_head *list)
|
|
{
|
|
unsigned long flags;
|
|
struct sk_buff *result;
|
|
|
|
spin_lock_irqsave(&list->lock, flags);
|
|
result = __skb_dequeue_tail(list);
|
|
spin_unlock_irqrestore(&list->lock, flags);
|
|
return result;
|
|
}
|
|
|
|
/**
|
|
* 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 takes the list
|
|
* lock and is atomic with respect to other list locking functions.
|
|
*/
|
|
void skb_queue_purge(struct sk_buff_head *list)
|
|
{
|
|
struct sk_buff *skb;
|
|
while ((skb = skb_dequeue(list)) != NULL)
|
|
kfree_skb(skb);
|
|
}
|
|
|
|
/**
|
|
* 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 the list. This function takes the
|
|
* list lock and can be used safely with other locking &sk_buff functions
|
|
* safely.
|
|
*
|
|
* A buffer cannot be placed on two lists at the same time.
|
|
*/
|
|
void skb_queue_head(struct sk_buff_head *list, struct sk_buff *newsk)
|
|
{
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(&list->lock, flags);
|
|
__skb_queue_head(list, newsk);
|
|
spin_unlock_irqrestore(&list->lock, flags);
|
|
}
|
|
|
|
/**
|
|
* skb_queue_tail - queue a buffer at the list tail
|
|
* @list: list to use
|
|
* @newsk: buffer to queue
|
|
*
|
|
* Queue a buffer at the tail of the list. This function takes the
|
|
* list lock and can be used safely with other locking &sk_buff functions
|
|
* safely.
|
|
*
|
|
* A buffer cannot be placed on two lists at the same time.
|
|
*/
|
|
void skb_queue_tail(struct sk_buff_head *list, struct sk_buff *newsk)
|
|
{
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(&list->lock, flags);
|
|
__skb_queue_tail(list, newsk);
|
|
spin_unlock_irqrestore(&list->lock, flags);
|
|
}
|
|
/**
|
|
* skb_unlink - remove a buffer from a list
|
|
* @skb: buffer to remove
|
|
*
|
|
* Place a packet after a given packet in a list. The list locks are taken
|
|
* and this function is atomic with respect to other list locked calls
|
|
*
|
|
* Works even without knowing the list it is sitting on, which can be
|
|
* handy at times. It also means that THE LIST MUST EXIST when you
|
|
* unlink. Thus a list must have its contents unlinked before it is
|
|
* destroyed.
|
|
*/
|
|
void skb_unlink(struct sk_buff *skb)
|
|
{
|
|
struct sk_buff_head *list = skb->list;
|
|
|
|
if (list) {
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(&list->lock, flags);
|
|
if (skb->list == list)
|
|
__skb_unlink(skb, skb->list);
|
|
spin_unlock_irqrestore(&list->lock, flags);
|
|
}
|
|
}
|
|
|
|
|
|
/**
|
|
* skb_append - append a buffer
|
|
* @old: buffer to insert after
|
|
* @newsk: buffer to insert
|
|
*
|
|
* Place a packet after a given packet in a list. The list locks are taken
|
|
* and this function is atomic with respect to other list locked calls.
|
|
* A buffer cannot be placed on two lists at the same time.
|
|
*/
|
|
|
|
void skb_append(struct sk_buff *old, struct sk_buff *newsk)
|
|
{
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(&old->list->lock, flags);
|
|
__skb_append(old, newsk);
|
|
spin_unlock_irqrestore(&old->list->lock, flags);
|
|
}
|
|
|
|
|
|
/**
|
|
* skb_insert - insert a buffer
|
|
* @old: buffer to insert before
|
|
* @newsk: buffer to insert
|
|
*
|
|
* Place a packet before a given packet in a list. The list locks are taken
|
|
* and this function is atomic with respect to other list locked calls
|
|
* A buffer cannot be placed on two lists at the same time.
|
|
*/
|
|
|
|
void skb_insert(struct sk_buff *old, struct sk_buff *newsk)
|
|
{
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(&old->list->lock, flags);
|
|
__skb_insert(newsk, old->prev, old, old->list);
|
|
spin_unlock_irqrestore(&old->list->lock, flags);
|
|
}
|
|
|
|
#if 0
|
|
/*
|
|
* Tune the memory allocator for a new MTU size.
|
|
*/
|
|
void skb_add_mtu(int mtu)
|
|
{
|
|
/* Must match allocation in alloc_skb */
|
|
mtu = SKB_DATA_ALIGN(mtu) + sizeof(struct skb_shared_info);
|
|
|
|
kmem_add_cache_size(mtu);
|
|
}
|
|
#endif
|
|
|
|
static inline void skb_split_inside_header(struct sk_buff *skb,
|
|
struct sk_buff* skb1,
|
|
const u32 len, const int pos)
|
|
{
|
|
int i;
|
|
|
|
memcpy(skb_put(skb1, pos - len), skb->data + len, pos - len);
|
|
|
|
/* And move data appendix as is. */
|
|
for (i = 0; i < skb_shinfo(skb)->nr_frags; i++)
|
|
skb_shinfo(skb1)->frags[i] = skb_shinfo(skb)->frags[i];
|
|
|
|
skb_shinfo(skb1)->nr_frags = skb_shinfo(skb)->nr_frags;
|
|
skb_shinfo(skb)->nr_frags = 0;
|
|
skb1->data_len = skb->data_len;
|
|
skb1->len += skb1->data_len;
|
|
skb->data_len = 0;
|
|
skb->len = len;
|
|
skb->tail = skb->data + len;
|
|
}
|
|
|
|
static inline void skb_split_no_header(struct sk_buff *skb,
|
|
struct sk_buff* skb1,
|
|
const u32 len, int pos)
|
|
{
|
|
int i, k = 0;
|
|
const int nfrags = skb_shinfo(skb)->nr_frags;
|
|
|
|
skb_shinfo(skb)->nr_frags = 0;
|
|
skb1->len = skb1->data_len = skb->len - len;
|
|
skb->len = len;
|
|
skb->data_len = len - pos;
|
|
|
|
for (i = 0; i < nfrags; i++) {
|
|
int size = skb_shinfo(skb)->frags[i].size;
|
|
|
|
if (pos + size > len) {
|
|
skb_shinfo(skb1)->frags[k] = skb_shinfo(skb)->frags[i];
|
|
|
|
if (pos < len) {
|
|
/* Split frag.
|
|
* We have two variants in this case:
|
|
* 1. Move all the frag to the second
|
|
* part, if it is possible. F.e.
|
|
* this approach is mandatory for TUX,
|
|
* where splitting is expensive.
|
|
* 2. Split is accurately. We make this.
|
|
*/
|
|
get_page(skb_shinfo(skb)->frags[i].page);
|
|
skb_shinfo(skb1)->frags[0].page_offset += len - pos;
|
|
skb_shinfo(skb1)->frags[0].size -= len - pos;
|
|
skb_shinfo(skb)->frags[i].size = len - pos;
|
|
skb_shinfo(skb)->nr_frags++;
|
|
}
|
|
k++;
|
|
} else
|
|
skb_shinfo(skb)->nr_frags++;
|
|
pos += size;
|
|
}
|
|
skb_shinfo(skb1)->nr_frags = k;
|
|
}
|
|
|
|
/**
|
|
* skb_split - Split fragmented skb to two parts at length len.
|
|
* @skb: the buffer to split
|
|
* @skb1: the buffer to receive the second part
|
|
* @len: new length for skb
|
|
*/
|
|
void skb_split(struct sk_buff *skb, struct sk_buff *skb1, const u32 len)
|
|
{
|
|
int pos = skb_headlen(skb);
|
|
|
|
if (len < pos) /* Split line is inside header. */
|
|
skb_split_inside_header(skb, skb1, len, pos);
|
|
else /* Second chunk has no header, nothing to copy. */
|
|
skb_split_no_header(skb, skb1, len, pos);
|
|
}
|
|
|
|
void __init skb_init(void)
|
|
{
|
|
skbuff_head_cache = kmem_cache_create("skbuff_head_cache",
|
|
sizeof(struct sk_buff),
|
|
0,
|
|
SLAB_HWCACHE_ALIGN,
|
|
NULL, NULL);
|
|
if (!skbuff_head_cache)
|
|
panic("cannot create skbuff cache");
|
|
}
|
|
|
|
EXPORT_SYMBOL(___pskb_trim);
|
|
EXPORT_SYMBOL(__kfree_skb);
|
|
EXPORT_SYMBOL(__pskb_pull_tail);
|
|
EXPORT_SYMBOL(alloc_skb);
|
|
EXPORT_SYMBOL(pskb_copy);
|
|
EXPORT_SYMBOL(pskb_expand_head);
|
|
EXPORT_SYMBOL(skb_checksum);
|
|
EXPORT_SYMBOL(skb_clone);
|
|
EXPORT_SYMBOL(skb_clone_fraglist);
|
|
EXPORT_SYMBOL(skb_copy);
|
|
EXPORT_SYMBOL(skb_copy_and_csum_bits);
|
|
EXPORT_SYMBOL(skb_copy_and_csum_dev);
|
|
EXPORT_SYMBOL(skb_copy_bits);
|
|
EXPORT_SYMBOL(skb_copy_expand);
|
|
EXPORT_SYMBOL(skb_over_panic);
|
|
EXPORT_SYMBOL(skb_pad);
|
|
EXPORT_SYMBOL(skb_realloc_headroom);
|
|
EXPORT_SYMBOL(skb_under_panic);
|
|
EXPORT_SYMBOL(skb_dequeue);
|
|
EXPORT_SYMBOL(skb_dequeue_tail);
|
|
EXPORT_SYMBOL(skb_insert);
|
|
EXPORT_SYMBOL(skb_queue_purge);
|
|
EXPORT_SYMBOL(skb_queue_head);
|
|
EXPORT_SYMBOL(skb_queue_tail);
|
|
EXPORT_SYMBOL(skb_unlink);
|
|
EXPORT_SYMBOL(skb_append);
|
|
EXPORT_SYMBOL(skb_split);
|