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Diffstat (limited to 'net/core/skbuff.c')
-rw-r--r--net/core/skbuff.c91
1 files changed, 65 insertions, 26 deletions
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 44f6a181a754..476aa3978504 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -257,11 +257,11 @@ nodata:
}
-static void skb_drop_fraglist(struct sk_buff *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 +270,11 @@ 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 +835,75 @@ 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;
+
+ if (skb_cloned(skb) &&
+ unlikely((err = pskb_expand_head(skb, 0, 0, GFP_ATOMIC))))
+ return err;
for (i = 0; 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;
+
+ if (len > offset)
+ skb_shinfo(skb)->frags[i++].size = len - offset;
+
+ 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);
+ break;
}
- 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;
+ 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;
+ }
+
+ 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;