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-rw-r--r--net/core/skbuff.c467
1 files changed, 313 insertions, 154 deletions
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 336958fbbcb2..32f087b5233e 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -55,6 +55,7 @@
#include <linux/cache.h>
#include <linux/rtnetlink.h>
#include <linux/init.h>
+#include <linux/scatterlist.h>
#include <net/protocol.h>
#include <net/dst.h>
@@ -87,8 +88,9 @@ static struct kmem_cache *skbuff_fclone_cache __read_mostly;
void skb_over_panic(struct sk_buff *skb, int sz, void *here)
{
printk(KERN_EMERG "skb_over_panic: text:%p len:%d put:%d head:%p "
- "data:%p tail:%p end:%p dev:%s\n",
- here, skb->len, sz, skb->head, skb->data, skb->tail, skb->end,
+ "data:%p tail:%#lx end:%#lx dev:%s\n",
+ here, skb->len, sz, skb->head, skb->data,
+ (unsigned long)skb->tail, (unsigned long)skb->end,
skb->dev ? skb->dev->name : "<NULL>");
BUG();
}
@@ -105,8 +107,9 @@ void skb_over_panic(struct sk_buff *skb, int sz, void *here)
void skb_under_panic(struct sk_buff *skb, int sz, void *here)
{
printk(KERN_EMERG "skb_under_panic: text:%p len:%d put:%d head:%p "
- "data:%p tail:%p end:%p dev:%s\n",
- here, skb->len, sz, skb->head, skb->data, skb->tail, skb->end,
+ "data:%p tail:%#lx end:%#lx dev:%s\n",
+ here, skb->len, sz, skb->head, skb->data,
+ (unsigned long)skb->tail, (unsigned long)skb->end,
skb->dev ? skb->dev->name : "<NULL>");
BUG();
}
@@ -155,20 +158,22 @@ struct sk_buff *__alloc_skb(unsigned int size, gfp_t gfp_mask,
if (!skb)
goto out;
- /* Get the DATA. Size must match skb_add_mtu(). */
size = SKB_DATA_ALIGN(size);
data = kmalloc_node_track_caller(size + sizeof(struct skb_shared_info),
gfp_mask, node);
if (!data)
goto nodata;
- memset(skb, 0, offsetof(struct sk_buff, truesize));
+ /*
+ * See comment in sk_buff definition, just before the 'tail' member
+ */
+ memset(skb, 0, offsetof(struct sk_buff, tail));
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;
+ skb_reset_tail_pointer(skb);
+ skb->end = skb->tail + size;
/* make sure we initialize shinfo sequentially */
shinfo = skb_shinfo(skb);
atomic_set(&shinfo->dataref, 1);
@@ -299,7 +304,7 @@ void kfree_skbmem(struct sk_buff *skb)
if (atomic_dec_and_test(fclone_ref))
kmem_cache_free(skbuff_fclone_cache, other);
break;
- };
+ }
}
/**
@@ -321,15 +326,13 @@ void __kfree_skb(struct sk_buff *skb)
WARN_ON(in_irq());
skb->destructor(skb);
}
-#ifdef CONFIG_NETFILTER
- nf_conntrack_put(skb->nfct);
#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
+ nf_conntrack_put(skb->nfct);
nf_conntrack_put_reasm(skb->nfct_reasm);
#endif
#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;
@@ -396,9 +399,9 @@ struct sk_buff *skb_clone(struct sk_buff *skb, gfp_t gfp_mask)
n->sk = NULL;
C(tstamp);
C(dev);
- C(h);
- C(nh);
- C(mac);
+ C(transport_header);
+ C(network_header);
+ C(mac_header);
C(dst);
dst_clone(skb->dst);
C(sp);
@@ -422,19 +425,7 @@ struct sk_buff *skb_clone(struct sk_buff *skb, gfp_t gfp_mask)
C(protocol);
n->destructor = NULL;
C(mark);
-#ifdef CONFIG_NETFILTER
- C(nfct);
- nf_conntrack_get(skb->nfct);
- C(nfctinfo);
-#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
- C(nfct_reasm);
- nf_conntrack_get_reasm(skb->nfct_reasm);
-#endif
-#ifdef CONFIG_BRIDGE_NETFILTER
- C(nf_bridge);
- nf_bridge_get(skb->nf_bridge);
-#endif
-#endif /*CONFIG_NETFILTER*/
+ __nf_copy(n, skb);
#ifdef CONFIG_NET_SCHED
C(tc_index);
#ifdef CONFIG_NET_CLS_ACT
@@ -460,11 +451,12 @@ struct sk_buff *skb_clone(struct sk_buff *skb, gfp_t gfp_mask)
static void copy_skb_header(struct sk_buff *new, const struct sk_buff *old)
{
+#ifndef NET_SKBUFF_DATA_USES_OFFSET
/*
* Shift between the two data areas in bytes
*/
unsigned long offset = new->data - old->data;
-
+#endif
new->sk = NULL;
new->dev = old->dev;
new->priority = old->priority;
@@ -473,9 +465,15 @@ static void copy_skb_header(struct sk_buff *new, const struct sk_buff *old)
#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;
+ new->transport_header = old->transport_header;
+ new->network_header = old->network_header;
+ new->mac_header = old->mac_header;
+#ifndef NET_SKBUFF_DATA_USES_OFFSET
+ /* {transport,network,mac}_header are relative to skb->head */
+ new->transport_header += offset;
+ new->network_header += offset;
+ new->mac_header += offset;
+#endif
memcpy(new->cb, old->cb, sizeof(old->cb));
new->local_df = old->local_df;
new->fclone = SKB_FCLONE_UNAVAILABLE;
@@ -483,22 +481,10 @@ static void copy_skb_header(struct sk_buff *new, const struct sk_buff *old)
new->tstamp = old->tstamp;
new->destructor = NULL;
new->mark = old->mark;
-#ifdef CONFIG_NETFILTER
- new->nfct = old->nfct;
- nf_conntrack_get(old->nfct);
- new->nfctinfo = old->nfctinfo;
-#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
- new->nfct_reasm = old->nfct_reasm;
- nf_conntrack_get_reasm(old->nfct_reasm);
-#endif
+ __nf_copy(new, old);
#if defined(CONFIG_IP_VS) || defined(CONFIG_IP_VS_MODULE)
new->ipvs_property = old->ipvs_property;
#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;
@@ -535,8 +521,12 @@ struct sk_buff *skb_copy(const struct sk_buff *skb, gfp_t gfp_mask)
/*
* Allocate the copy buffer
*/
- struct sk_buff *n = alloc_skb(skb->end - skb->head + skb->data_len,
- gfp_mask);
+ struct sk_buff *n;
+#ifdef NET_SKBUFF_DATA_USES_OFFSET
+ n = alloc_skb(skb->end + skb->data_len, gfp_mask);
+#else
+ n = alloc_skb(skb->end - skb->head + skb->data_len, gfp_mask);
+#endif
if (!n)
return NULL;
@@ -573,8 +563,12 @@ struct sk_buff *pskb_copy(struct sk_buff *skb, gfp_t gfp_mask)
/*
* Allocate the copy buffer
*/
- struct sk_buff *n = alloc_skb(skb->end - skb->head, gfp_mask);
-
+ struct sk_buff *n;
+#ifdef NET_SKBUFF_DATA_USES_OFFSET
+ n = alloc_skb(skb->end, gfp_mask);
+#else
+ n = alloc_skb(skb->end - skb->head, gfp_mask);
+#endif
if (!n)
goto out;
@@ -583,7 +577,7 @@ struct sk_buff *pskb_copy(struct sk_buff *skb, gfp_t gfp_mask)
/* Set the tail pointer and length */
skb_put(n, skb_headlen(skb));
/* Copy the bytes */
- memcpy(n->data, skb->data, n->len);
+ skb_copy_from_linear_data(skb, n->data, n->len);
n->csum = skb->csum;
n->ip_summed = skb->ip_summed;
@@ -632,7 +626,11 @@ int pskb_expand_head(struct sk_buff *skb, int nhead, int ntail,
{
int i;
u8 *data;
+#ifdef NET_SKBUFF_DATA_USES_OFFSET
+ int size = nhead + skb->end + ntail;
+#else
int size = nhead + (skb->end - skb->head) + ntail;
+#endif
long off;
if (skb_shared(skb))
@@ -646,8 +644,14 @@ int pskb_expand_head(struct sk_buff *skb, int nhead, int ntail,
/* 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));
+ memcpy(data + nhead, skb->head,
+#ifdef NET_SKBUFF_DATA_USES_OFFSET
+ skb->tail);
+#else
+ skb->tail - skb->head);
+#endif
+ memcpy(data + size, skb_end_pointer(skb),
+ sizeof(struct skb_shared_info));
for (i = 0; i < skb_shinfo(skb)->nr_frags; i++)
get_page(skb_shinfo(skb)->frags[i].page);
@@ -660,12 +664,18 @@ int pskb_expand_head(struct sk_buff *skb, int nhead, int ntail,
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;
+#ifdef NET_SKBUFF_DATA_USES_OFFSET
+ skb->end = size;
+ off = nhead;
+#else
+ skb->end = skb->head + size;
+#endif
+ /* {transport,network,mac}_header and tail are relative to skb->head */
+ skb->tail += off;
+ skb->transport_header += off;
+ skb->network_header += off;
+ skb->mac_header += off;
skb->cloned = 0;
skb->nohdr = 0;
atomic_set(&skb_shinfo(skb)->dataref, 1);
@@ -726,7 +736,9 @@ struct sk_buff *skb_copy_expand(const struct sk_buff *skb,
*/
struct sk_buff *n = alloc_skb(newheadroom + skb->len + newtailroom,
gfp_mask);
+ int oldheadroom = skb_headroom(skb);
int head_copy_len, head_copy_off;
+ int off = 0;
if (!n)
return NULL;
@@ -736,7 +748,7 @@ struct sk_buff *skb_copy_expand(const struct sk_buff *skb,
/* Set the tail pointer and length */
skb_put(n, skb->len);
- head_copy_len = skb_headroom(skb);
+ head_copy_len = oldheadroom;
head_copy_off = 0;
if (newheadroom <= head_copy_len)
head_copy_len = newheadroom;
@@ -750,6 +762,13 @@ struct sk_buff *skb_copy_expand(const struct sk_buff *skb,
copy_skb_header(n, skb);
+#ifdef NET_SKBUFF_DATA_USES_OFFSET
+ off = newheadroom - oldheadroom;
+#endif
+ n->transport_header += off;
+ n->network_header += off;
+ n->mac_header += off;
+
return n;
}
@@ -877,7 +896,7 @@ done:
} else {
skb->len = len;
skb->data_len = 0;
- skb->tail = skb->data + len;
+ skb_set_tail_pointer(skb, len);
}
return 0;
@@ -922,7 +941,7 @@ unsigned char *__pskb_pull_tail(struct sk_buff *skb, int delta)
return NULL;
}
- if (skb_copy_bits(skb, skb_headlen(skb), skb->tail, delta))
+ if (skb_copy_bits(skb, skb_headlen(skb), skb_tail_pointer(skb), delta))
BUG();
/* Optimization: no fragments, no reasons to preestimate
@@ -1018,7 +1037,7 @@ pull_pages:
skb->tail += delta;
skb->data_len -= delta;
- return skb->tail;
+ return skb_tail_pointer(skb);
}
/* Copy some data bits from skb to kernel buffer. */
@@ -1026,16 +1045,16 @@ pull_pages:
int skb_copy_bits(const struct sk_buff *skb, int offset, void *to, int len)
{
int i, copy;
- int start = skb_headlen(skb);
+ int end = skb_headlen(skb);
if (offset > (int)skb->len - len)
goto fault;
/* Copy header. */
- if ((copy = start - offset) > 0) {
+ if ((copy = end - offset) > 0) {
if (copy > len)
copy = len;
- memcpy(to, skb->data + offset, copy);
+ skb_copy_from_linear_data_offset(skb, offset, to, copy);
if ((len -= copy) == 0)
return 0;
offset += copy;
@@ -1043,11 +1062,9 @@ int skb_copy_bits(const struct sk_buff *skb, int offset, void *to, int len)
}
for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
- int end;
+ BUG_TRAP(len >= 0);
- BUG_TRAP(start <= offset + len);
-
- end = start + skb_shinfo(skb)->frags[i].size;
+ end = offset + skb_shinfo(skb)->frags[i].size;
if ((copy = end - offset) > 0) {
u8 *vaddr;
@@ -1056,8 +1073,8 @@ int skb_copy_bits(const struct sk_buff *skb, int offset, void *to, int len)
vaddr = kmap_skb_frag(&skb_shinfo(skb)->frags[i]);
memcpy(to,
- vaddr + skb_shinfo(skb)->frags[i].page_offset+
- offset - start, copy);
+ vaddr + skb_shinfo(skb)->frags[i].page_offset,
+ copy);
kunmap_skb_frag(vaddr);
if ((len -= copy) == 0)
@@ -1065,30 +1082,25 @@ int skb_copy_bits(const struct sk_buff *skb, int offset, void *to, int len)
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);
+ BUG_TRAP(len >= 0);
- end = start + list->len;
+ end = offset + list->len;
if ((copy = end - offset) > 0) {
if (copy > len)
copy = len;
- if (skb_copy_bits(list, offset - start,
- to, copy))
+ if (skb_copy_bits(list, 0, to, copy))
goto fault;
if ((len -= copy) == 0)
return 0;
offset += copy;
to += copy;
}
- start = end;
}
}
if (!len)
@@ -1110,18 +1122,18 @@ fault:
* traversing fragment lists and such.
*/
-int skb_store_bits(const struct sk_buff *skb, int offset, void *from, int len)
+int skb_store_bits(struct sk_buff *skb, int offset, const void *from, int len)
{
int i, copy;
- int start = skb_headlen(skb);
+ int end = skb_headlen(skb);
if (offset > (int)skb->len - len)
goto fault;
- if ((copy = start - offset) > 0) {
+ if ((copy = end - offset) > 0) {
if (copy > len)
copy = len;
- memcpy(skb->data + offset, from, copy);
+ skb_copy_to_linear_data_offset(skb, offset, from, copy);
if ((len -= copy) == 0)
return 0;
offset += copy;
@@ -1130,11 +1142,9 @@ int skb_store_bits(const struct sk_buff *skb, int offset, void *from, int len)
for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
- int end;
+ BUG_TRAP(len >= 0);
- BUG_TRAP(start <= offset + len);
-
- end = start + frag->size;
+ end = offset + frag->size;
if ((copy = end - offset) > 0) {
u8 *vaddr;
@@ -1142,8 +1152,7 @@ int skb_store_bits(const struct sk_buff *skb, int offset, void *from, int len)
copy = len;
vaddr = kmap_skb_frag(frag);
- memcpy(vaddr + frag->page_offset + offset - start,
- from, copy);
+ memcpy(vaddr + frag->page_offset, from, copy);
kunmap_skb_frag(vaddr);
if ((len -= copy) == 0)
@@ -1151,30 +1160,25 @@ int skb_store_bits(const struct sk_buff *skb, int offset, void *from, int len)
offset += copy;
from += 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);
+ BUG_TRAP(len >= 0);
- end = start + list->len;
+ end = offset + list->len;
if ((copy = end - offset) > 0) {
if (copy > len)
copy = len;
- if (skb_store_bits(list, offset - start,
- from, copy))
+ if (skb_store_bits(list, 0, from, copy))
goto fault;
if ((len -= copy) == 0)
return 0;
offset += copy;
from += copy;
}
- start = end;
}
}
if (!len)
@@ -1191,8 +1195,8 @@ EXPORT_SYMBOL(skb_store_bits);
__wsum skb_checksum(const struct sk_buff *skb, int offset,
int len, __wsum csum)
{
- int start = skb_headlen(skb);
- int i, copy = start - offset;
+ int end = skb_headlen(skb);
+ int i, copy = end - offset;
int pos = 0;
/* Checksum header. */
@@ -1207,11 +1211,9 @@ __wsum skb_checksum(const struct sk_buff *skb, int offset,
}
for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
- int end;
+ BUG_TRAP(len >= 0);
- BUG_TRAP(start <= offset + len);
-
- end = start + skb_shinfo(skb)->frags[i].size;
+ end = offset + skb_shinfo(skb)->frags[i].size;
if ((copy = end - offset) > 0) {
__wsum csum2;
u8 *vaddr;
@@ -1220,8 +1222,8 @@ __wsum skb_checksum(const struct sk_buff *skb, int offset,
if (copy > len)
copy = len;
vaddr = kmap_skb_frag(frag);
- csum2 = csum_partial(vaddr + frag->page_offset +
- offset - start, copy, 0);
+ csum2 = csum_partial(vaddr + frag->page_offset,
+ copy, 0);
kunmap_skb_frag(vaddr);
csum = csum_block_add(csum, csum2, pos);
if (!(len -= copy))
@@ -1229,31 +1231,26 @@ __wsum skb_checksum(const struct sk_buff *skb, int offset,
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);
+ BUG_TRAP(len >= 0);
- end = start + list->len;
+ end = offset + list->len;
if ((copy = end - offset) > 0) {
__wsum csum2;
if (copy > len)
copy = len;
- csum2 = skb_checksum(list, offset - start,
- copy, 0);
+ csum2 = skb_checksum(list, 0, copy, 0);
csum = csum_block_add(csum, csum2, pos);
if ((len -= copy) == 0)
return csum;
offset += copy;
pos += copy;
}
- start = end;
}
}
BUG_ON(len);
@@ -1266,8 +1263,8 @@ __wsum skb_checksum(const struct sk_buff *skb, int offset,
__wsum skb_copy_and_csum_bits(const struct sk_buff *skb, int offset,
u8 *to, int len, __wsum csum)
{
- int start = skb_headlen(skb);
- int i, copy = start - offset;
+ int end = skb_headlen(skb);
+ int i, copy = end - offset;
int pos = 0;
/* Copy header. */
@@ -1284,11 +1281,9 @@ __wsum skb_copy_and_csum_bits(const struct sk_buff *skb, int offset,
}
for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
- int end;
+ BUG_TRAP(len >= 0);
- BUG_TRAP(start <= offset + len);
-
- end = start + skb_shinfo(skb)->frags[i].size;
+ end = offset + skb_shinfo(skb)->frags[i].size;
if ((copy = end - offset) > 0) {
__wsum csum2;
u8 *vaddr;
@@ -1298,9 +1293,8 @@ __wsum skb_copy_and_csum_bits(const struct sk_buff *skb, int offset,
copy = len;
vaddr = kmap_skb_frag(frag);
csum2 = csum_partial_copy_nocheck(vaddr +
- frag->page_offset +
- offset - start, to,
- copy, 0);
+ frag->page_offset,
+ to, copy, 0);
kunmap_skb_frag(vaddr);
csum = csum_block_add(csum, csum2, pos);
if (!(len -= copy))
@@ -1309,7 +1303,6 @@ __wsum skb_copy_and_csum_bits(const struct sk_buff *skb, int offset,
to += copy;
pos += copy;
}
- start = end;
}
if (skb_shinfo(skb)->frag_list) {
@@ -1317,16 +1310,13 @@ __wsum skb_copy_and_csum_bits(const struct sk_buff *skb, int offset,
for (; list; list = list->next) {
__wsum csum2;
- int end;
-
- BUG_TRAP(start <= offset + len);
+ BUG_TRAP(len >= 0);
- end = start + list->len;
+ end = offset + list->len;
if ((copy = end - offset) > 0) {
if (copy > len)
copy = len;
- csum2 = skb_copy_and_csum_bits(list,
- offset - start,
+ csum2 = skb_copy_and_csum_bits(list, 0,
to, copy, 0);
csum = csum_block_add(csum, csum2, pos);
if ((len -= copy) == 0)
@@ -1335,7 +1325,6 @@ __wsum skb_copy_and_csum_bits(const struct sk_buff *skb, int offset,
to += copy;
pos += copy;
}
- start = end;
}
}
BUG_ON(len);
@@ -1348,13 +1337,13 @@ void skb_copy_and_csum_dev(const struct sk_buff *skb, u8 *to)
long csstart;
if (skb->ip_summed == CHECKSUM_PARTIAL)
- csstart = skb->h.raw - skb->data;
+ csstart = skb->csum_start - skb_headroom(skb);
else
csstart = skb_headlen(skb);
BUG_ON(csstart > skb_headlen(skb));
- memcpy(to, skb->data, csstart);
+ skb_copy_from_linear_data(skb, to, csstart);
csum = 0;
if (csstart != skb->len)
@@ -1522,27 +1511,14 @@ void skb_insert(struct sk_buff *old, struct sk_buff *newsk, struct sk_buff_head
spin_unlock_irqrestore(&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);
-
+ skb_copy_from_linear_data_offset(skb, len, skb_put(skb1, pos - 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];
@@ -1553,7 +1529,7 @@ static inline void skb_split_inside_header(struct sk_buff *skb,
skb1->len += skb1->data_len;
skb->data_len = 0;
skb->len = len;
- skb->tail = skb->data + len;
+ skb_set_tail_pointer(skb, len);
}
static inline void skb_split_no_header(struct sk_buff *skb,
@@ -1878,7 +1854,7 @@ struct sk_buff *skb_segment(struct sk_buff *skb, int features)
struct sk_buff *segs = NULL;
struct sk_buff *tail = NULL;
unsigned int mss = skb_shinfo(skb)->gso_size;
- unsigned int doffset = skb->data - skb->mac.raw;
+ unsigned int doffset = skb->data - skb_mac_header(skb);
unsigned int offset = doffset;
unsigned int headroom;
unsigned int len;
@@ -1928,11 +1904,12 @@ struct sk_buff *skb_segment(struct sk_buff *skb, int features)
nskb->mac_len = skb->mac_len;
skb_reserve(nskb, headroom);
- nskb->mac.raw = nskb->data;
- nskb->nh.raw = nskb->data + skb->mac_len;
- nskb->h.raw = nskb->nh.raw + (skb->h.raw - skb->nh.raw);
- memcpy(skb_put(nskb, doffset), skb->data, doffset);
-
+ skb_reset_mac_header(nskb);
+ skb_set_network_header(nskb, skb->mac_len);
+ nskb->transport_header = (nskb->network_header +
+ skb_network_header_len(skb));
+ skb_copy_from_linear_data(skb, skb_put(nskb, doffset),
+ doffset);
if (!sg) {
nskb->csum = skb_copy_and_csum_bits(skb, offset,
skb_put(nskb, len),
@@ -1945,7 +1922,8 @@ struct sk_buff *skb_segment(struct sk_buff *skb, int features)
nskb->ip_summed = CHECKSUM_PARTIAL;
nskb->csum = skb->csum;
- memcpy(skb_put(nskb, hsize), skb->data + offset, hsize);
+ skb_copy_from_linear_data_offset(skb, offset,
+ skb_put(nskb, hsize), hsize);
while (pos < offset + len) {
BUG_ON(i >= nfrags);
@@ -2005,6 +1983,184 @@ void __init skb_init(void)
NULL, NULL);
}
+/**
+ * skb_to_sgvec - Fill a scatter-gather list from a socket buffer
+ * @skb: Socket buffer containing the buffers to be mapped
+ * @sg: The scatter-gather list to map into
+ * @offset: The offset into the buffer's contents to start mapping
+ * @len: Length of buffer space to be mapped
+ *
+ * Fill the specified scatter-gather list with mappings/pointers into a
+ * region of the buffer space attached to a socket buffer.
+ */
+int
+skb_to_sgvec(struct sk_buff *skb, struct scatterlist *sg, int offset, int len)
+{
+ int end = skb_headlen(skb);
+ int i, copy = end - offset;
+ int elt = 0;
+
+ if (copy > 0) {
+ if (copy > len)
+ copy = len;
+ sg[elt].page = virt_to_page(skb->data + offset);
+ sg[elt].offset = (unsigned long)(skb->data + offset) % PAGE_SIZE;
+ sg[elt].length = copy;
+ elt++;
+ if ((len -= copy) == 0)
+ return elt;
+ offset += copy;
+ }
+
+ for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
+ BUG_TRAP(len >= 0);
+
+ end = offset + skb_shinfo(skb)->frags[i].size;
+ if ((copy = end - offset) > 0) {
+ skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
+
+ if (copy > len)
+ copy = len;
+ sg[elt].page = frag->page;
+ sg[elt].offset = frag->page_offset;
+ sg[elt].length = copy;
+ elt++;
+ if (!(len -= copy))
+ return elt;
+ offset += copy;
+ }
+ }
+
+ if (skb_shinfo(skb)->frag_list) {
+ struct sk_buff *list = skb_shinfo(skb)->frag_list;
+
+ for (; list; list = list->next) {
+ BUG_TRAP(len >= 0);
+
+ end = offset + list->len;
+ if ((copy = end - offset) > 0) {
+ if (copy > len)
+ copy = len;
+ elt += skb_to_sgvec(list, sg+elt, 0, copy);
+ if ((len -= copy) == 0)
+ return elt;
+ offset += copy;
+ }
+ }
+ }
+ BUG_ON(len);
+ return elt;
+}
+
+/**
+ * skb_cow_data - Check that a socket buffer's data buffers are writable
+ * @skb: The socket buffer to check.
+ * @tailbits: Amount of trailing space to be added
+ * @trailer: Returned pointer to the skb where the @tailbits space begins
+ *
+ * Make sure that the data buffers attached to a socket buffer are
+ * writable. If they are not, private copies are made of the data buffers
+ * and the socket buffer is set to use these instead.
+ *
+ * If @tailbits is given, make sure that there is space to write @tailbits
+ * bytes of data beyond current end of socket buffer. @trailer will be
+ * set to point to the skb in which this space begins.
+ *
+ * The number of scatterlist elements required to completely map the
+ * COW'd and extended socket buffer will be returned.
+ */
+int skb_cow_data(struct sk_buff *skb, int tailbits, struct sk_buff **trailer)
+{
+ int copyflag;
+ int elt;
+ struct sk_buff *skb1, **skb_p;
+
+ /* If skb is cloned or its head is paged, reallocate
+ * head pulling out all the pages (pages are considered not writable
+ * at the moment even if they are anonymous).
+ */
+ if ((skb_cloned(skb) || skb_shinfo(skb)->nr_frags) &&
+ __pskb_pull_tail(skb, skb_pagelen(skb)-skb_headlen(skb)) == NULL)
+ return -ENOMEM;
+
+ /* Easy case. Most of packets will go this way. */
+ if (!skb_shinfo(skb)->frag_list) {
+ /* A little of trouble, not enough of space for trailer.
+ * This should not happen, when stack is tuned to generate
+ * good frames. OK, on miss we reallocate and reserve even more
+ * space, 128 bytes is fair. */
+
+ if (skb_tailroom(skb) < tailbits &&
+ pskb_expand_head(skb, 0, tailbits-skb_tailroom(skb)+128, GFP_ATOMIC))
+ return -ENOMEM;
+
+ /* Voila! */
+ *trailer = skb;
+ return 1;
+ }
+
+ /* Misery. We are in troubles, going to mincer fragments... */
+
+ elt = 1;
+ skb_p = &skb_shinfo(skb)->frag_list;
+ copyflag = 0;
+
+ while ((skb1 = *skb_p) != NULL) {
+ int ntail = 0;
+
+ /* The fragment is partially pulled by someone,
+ * this can happen on input. Copy it and everything
+ * after it. */
+
+ if (skb_shared(skb1))
+ copyflag = 1;
+
+ /* If the skb is the last, worry about trailer. */
+
+ if (skb1->next == NULL && tailbits) {
+ if (skb_shinfo(skb1)->nr_frags ||
+ skb_shinfo(skb1)->frag_list ||
+ skb_tailroom(skb1) < tailbits)
+ ntail = tailbits + 128;
+ }
+
+ if (copyflag ||
+ skb_cloned(skb1) ||
+ ntail ||
+ skb_shinfo(skb1)->nr_frags ||
+ skb_shinfo(skb1)->frag_list) {
+ struct sk_buff *skb2;
+
+ /* Fuck, we are miserable poor guys... */
+ if (ntail == 0)
+ skb2 = skb_copy(skb1, GFP_ATOMIC);
+ else
+ skb2 = skb_copy_expand(skb1,
+ skb_headroom(skb1),
+ ntail,
+ GFP_ATOMIC);
+ if (unlikely(skb2 == NULL))
+ return -ENOMEM;
+
+ if (skb1->sk)
+ skb_set_owner_w(skb2, skb1->sk);
+
+ /* Looking around. Are we still alive?
+ * OK, link new skb, drop old one */
+
+ skb2->next = skb1->next;
+ *skb_p = skb2;
+ kfree_skb(skb1);
+ skb1 = skb2;
+ }
+ elt++;
+ *trailer = skb1;
+ skb_p = &skb1->next;
+ }
+
+ return elt;
+}
+
EXPORT_SYMBOL(___pskb_trim);
EXPORT_SYMBOL(__kfree_skb);
EXPORT_SYMBOL(kfree_skb);
@@ -2039,3 +2195,6 @@ EXPORT_SYMBOL(skb_seq_read);
EXPORT_SYMBOL(skb_abort_seq_read);
EXPORT_SYMBOL(skb_find_text);
EXPORT_SYMBOL(skb_append_datato_frags);
+
+EXPORT_SYMBOL_GPL(skb_to_sgvec);
+EXPORT_SYMBOL_GPL(skb_cow_data);
generated by cgit v1.2.3-58-ga151 (git 2.39.0) at 2024-12-27 22:11:39 +0000