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Diffstat (limited to 'net/core/skbuff.c')
-rw-r--r--net/core/skbuff.c132
1 files changed, 98 insertions, 34 deletions
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 44f6a181a75..c54f3664bce 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -71,13 +71,6 @@ static kmem_cache_t *skbuff_head_cache __read_mostly;
static kmem_cache_t *skbuff_fclone_cache __read_mostly;
/*
- * lockdep: lock class key used by skb_queue_head_init():
- */
-struct lock_class_key skb_queue_lock_key;
-
-EXPORT_SYMBOL(skb_queue_lock_key);
-
-/*
* Keep out-of-line to prevent kernel bloat.
* __builtin_return_address is not used because it is not always
* reliable.
@@ -256,12 +249,37 @@ nodata:
goto out;
}
+/**
+ * __netdev_alloc_skb - allocate an skbuff for rx on a specific device
+ * @dev: network device to receive on
+ * @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 if there is no free memory.
+ */
+struct sk_buff *__netdev_alloc_skb(struct net_device *dev,
+ unsigned int length, gfp_t gfp_mask)
+{
+ struct sk_buff *skb;
-static void skb_drop_fraglist(struct sk_buff *skb)
+ skb = alloc_skb(length + NET_SKB_PAD, gfp_mask);
+ if (likely(skb)) {
+ skb_reserve(skb, NET_SKB_PAD);
+ skb->dev = dev;
+ }
+ return skb;
+}
+
+static void skb_drop_list(struct sk_buff **listp)
{
- struct sk_buff *list = skb_shinfo(skb)->frag_list;
+ struct sk_buff *list = *listp;
- skb_shinfo(skb)->frag_list = NULL;
+ *listp = NULL;
do {
struct sk_buff *this = list;
@@ -270,6 +288,11 @@ static void skb_drop_fraglist(struct sk_buff *skb)
} while (list);
}
+static inline void skb_drop_fraglist(struct sk_buff *skb)
+{
+ skb_drop_list(&skb_shinfo(skb)->frag_list);
+}
+
static void skb_clone_fraglist(struct sk_buff *skb)
{
struct sk_buff *list;
@@ -830,41 +853,81 @@ free_skb:
int ___pskb_trim(struct sk_buff *skb, unsigned int len)
{
+ struct sk_buff **fragp;
+ struct sk_buff *frag;
int offset = skb_headlen(skb);
int nfrags = skb_shinfo(skb)->nr_frags;
int i;
+ int err;
- for (i = 0; i < nfrags; i++) {
+ if (skb_cloned(skb) &&
+ unlikely((err = pskb_expand_head(skb, 0, 0, GFP_ATOMIC))))
+ return err;
+
+ i = 0;
+ if (offset >= len)
+ goto drop_pages;
+
+ for (; i < nfrags; i++) {
int end = offset + skb_shinfo(skb)->frags[i].size;
- if (end > len) {
- if (skb_cloned(skb)) {
- 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;
- }
+
+ if (end < len) {
+ offset = end;
+ continue;
}
- offset = end;
+
+ skb_shinfo(skb)->frags[i++].size = len - offset;
+
+drop_pages:
+ skb_shinfo(skb)->nr_frags = i;
+
+ for (; i < nfrags; i++)
+ put_page(skb_shinfo(skb)->frags[i].page);
+
+ if (skb_shinfo(skb)->frag_list)
+ skb_drop_fraglist(skb);
+ goto done;
}
- if (offset < len) {
+ for (fragp = &skb_shinfo(skb)->frag_list; (frag = *fragp);
+ fragp = &frag->next) {
+ int end = offset + frag->len;
+
+ if (skb_shared(frag)) {
+ struct sk_buff *nfrag;
+
+ nfrag = skb_clone(frag, GFP_ATOMIC);
+ if (unlikely(!nfrag))
+ return -ENOMEM;
+
+ nfrag->next = frag->next;
+ kfree_skb(frag);
+ frag = nfrag;
+ *fragp = frag;
+ }
+
+ if (end < len) {
+ offset = end;
+ continue;
+ }
+
+ if (end > len &&
+ unlikely((err = pskb_trim(frag, len - offset))))
+ return err;
+
+ if (frag->next)
+ skb_drop_list(&frag->next);
+ break;
+ }
+
+done:
+ if (len > skb_headlen(skb)) {
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;
- }
+ skb->len = len;
+ skb->data_len = 0;
+ skb->tail = skb->data + len;
}
return 0;
@@ -2003,6 +2066,7 @@ EXPORT_SYMBOL(__kfree_skb);
EXPORT_SYMBOL(kfree_skb);
EXPORT_SYMBOL(__pskb_pull_tail);
EXPORT_SYMBOL(__alloc_skb);
+EXPORT_SYMBOL(__netdev_alloc_skb);
EXPORT_SYMBOL(pskb_copy);
EXPORT_SYMBOL(pskb_expand_head);
EXPORT_SYMBOL(skb_checksum);