goto nodata;
/*
- * See comment in sk_buff definition, just before the 'tail' member
+ * Only clear those fields we need to clear, not those that we will
+ * actually initialise below. Hence, don't put any more fields after
+ * the tail pointer in struct sk_buff!
*/
memset(skb, 0, offsetof(struct sk_buff, tail));
skb->truesize = size + sizeof(struct sk_buff);
return skb;
}
+/**
+ * dev_alloc_skb - allocate an skbuff for receiving
+ * @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 if there is no free memory. Although this function
+ * allocates memory it can be called from an interrupt.
+ */
+struct sk_buff *dev_alloc_skb(unsigned int length)
+{
+ /*
+ * There is more code here than it seems:
+ * __dev_alloc_skb is an inline
+ */
+ return __dev_alloc_skb(length, GFP_ATOMIC);
+}
+EXPORT_SYMBOL(dev_alloc_skb);
+
static void skb_drop_list(struct sk_buff **listp)
{
struct sk_buff *list = *listp;
return err;
}
+/**
+ * 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.
+ */
+unsigned char *skb_put(struct sk_buff *skb, unsigned int len)
+{
+ unsigned char *tmp = skb_tail_pointer(skb);
+ SKB_LINEAR_ASSERT(skb);
+ skb->tail += len;
+ skb->len += len;
+ if (unlikely(skb->tail > skb->end))
+ skb_over_panic(skb, len, __builtin_return_address(0));
+ return tmp;
+}
+EXPORT_SYMBOL(skb_put);
+
+/**
+ * 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.
+ */
+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, __builtin_return_address(0));
+ return skb->data;
+}
+EXPORT_SYMBOL(skb_push);
+
+/**
+ * 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.
+ */
+unsigned char *skb_pull(struct sk_buff *skb, unsigned int len)
+{
+ return unlikely(len > skb->len) ? NULL : __skb_pull(skb, len);
+}
+EXPORT_SYMBOL(skb_pull);
+
+/**
+ * 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.
+ * The skb must be linear.
+ */
+void skb_trim(struct sk_buff *skb, unsigned int len)
+{
+ if (skb->len > len)
+ __skb_trim(skb, len);
+}
+EXPORT_SYMBOL(skb_trim);
+
/* Trims skb to length len. It can change skb pointers.
*/
{
unsigned int nr_pages = spd->nr_pages;
unsigned int poff, plen, len, toff, tlen;
- int headlen, seg;
+ int headlen, seg, error = 0;
toff = *offset;
tlen = *total_len;
- if (!tlen)
+ if (!tlen) {
+ error = 1;
goto err;
+ }
/*
* if the offset is greater than the linear part, go directly to
* just jump directly to update and return, no point
* in going over fragments when the output is full.
*/
- if (spd_fill_page(spd, virt_to_page(p), plen, poff, skb))
+ error = spd_fill_page(spd, virt_to_page(p), plen, poff, skb);
+ if (error)
goto done;
tlen -= plen;
if (!plen)
break;
- if (spd_fill_page(spd, f->page, plen, poff, skb))
+ error = spd_fill_page(spd, f->page, plen, poff, skb);
+ if (error)
break;
tlen -= plen;
return 0;
}
err:
- return 1;
+ /* update the offset to reflect the linear part skip, if any */
+ if (!error)
+ *offset = toff;
+ return error;
}
/*
if (spd.nr_pages) {
int ret;
+ struct sock *sk = __skb->sk;
/*
* Drop the socket lock, otherwise we have reverse
* we call into ->sendpage() with the i_mutex lock held
* and networking will grab the socket lock.
*/
- release_sock(__skb->sk);
+ release_sock(sk);
ret = splice_to_pipe(pipe, &spd);
- lock_sock(__skb->sk);
+ lock_sock(sk);
return ret;
}
unsigned long flags;
spin_lock_irqsave(&list->lock, flags);
- __skb_append(old, newsk, list);
+ __skb_queue_after(list, old, newsk);
spin_unlock_irqrestore(&list->lock, flags);
}
/**
* skb_pull_rcsum - pull skb and update receive checksum
* @skb: buffer to update
- * @start: start of data before pull
* @len: length of data pulled
*
* This function performs an skb_pull on the packet and updates
- * update the CHECKSUM_COMPLETE checksum. It should be used on
+ * the CHECKSUM_COMPLETE checksum. It should be used on
* receive path processing instead of skb_pull unless you know
* that the checksum difference is zero (e.g., a valid IP header)
* or you are setting ip_summed to CHECKSUM_NONE.
* @features: features for the output path (see dev->features)
*
* This function performs segmentation on the given skb. It returns
- * the segment at the given position. It returns NULL if there are
- * no more segments to generate, or when an error is encountered.
+ * a pointer to the first in a list of new skbs for the segments.
+ * In case of error it returns ERR_PTR(err).
*/
struct sk_buff *skb_segment(struct sk_buff *skb, int features)
{
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff