/*
* Routines having to do with the 'struct sk_buff' memory handlers.
*
- * Authors: Alan Cox <iiitac@pyr.swan.ac.uk>
+ * Authors: Alan Cox <alan@lxorguk.ukuu.org.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.
void skb_truesize_bug(struct sk_buff *skb)
{
- printk(KERN_ERR "SKB BUG: Invalid truesize (%u) "
+ WARN(net_ratelimit(), KERN_ERR "SKB BUG: Invalid truesize (%u) "
"len=%u, sizeof(sk_buff)=%Zd\n",
skb->truesize, skb->len, sizeof(struct sk_buff));
}
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;
}
+struct page *__netdev_alloc_page(struct net_device *dev, gfp_t gfp_mask)
+{
+ int node = dev->dev.parent ? dev_to_node(dev->dev.parent) : -1;
+ struct page *page;
+
+ page = alloc_pages_node(node, gfp_mask, 0);
+ return page;
+}
+EXPORT_SYMBOL(__netdev_alloc_page);
+
+void skb_add_rx_frag(struct sk_buff *skb, int i, struct page *page, int off,
+ int size)
+{
+ skb_fill_page_desc(skb, i, page, off, size);
+ skb->len += size;
+ skb->data_len += size;
+ skb->truesize += size;
+}
+EXPORT_SYMBOL(skb_add_rx_frag);
+
+/**
+ * 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;
}
}
-/* Free everything but the sk_buff shell. */
-static void skb_release_all(struct sk_buff *skb)
+static void skb_release_head_state(struct sk_buff *skb)
{
dst_release(skb->dst);
#ifdef CONFIG_XFRM
skb->tc_verd = 0;
#endif
#endif
+}
+
+/* Free everything but the sk_buff shell. */
+static void skb_release_all(struct sk_buff *skb)
+{
+ skb_release_head_state(skb);
skb_release_data(skb);
}
__kfree_skb(skb);
}
+/**
+ * skb_recycle_check - check if skb can be reused for receive
+ * @skb: buffer
+ * @skb_size: minimum receive buffer size
+ *
+ * Checks that the skb passed in is not shared or cloned, and
+ * that it is linear and its head portion at least as large as
+ * skb_size so that it can be recycled as a receive buffer.
+ * If these conditions are met, this function does any necessary
+ * reference count dropping and cleans up the skbuff as if it
+ * just came from __alloc_skb().
+ */
+int skb_recycle_check(struct sk_buff *skb, int skb_size)
+{
+ struct skb_shared_info *shinfo;
+
+ if (skb_is_nonlinear(skb) || skb->fclone != SKB_FCLONE_UNAVAILABLE)
+ return 0;
+
+ skb_size = SKB_DATA_ALIGN(skb_size + NET_SKB_PAD);
+ if (skb_end_pointer(skb) - skb->head < skb_size)
+ return 0;
+
+ if (skb_shared(skb) || skb_cloned(skb))
+ return 0;
+
+ skb_release_head_state(skb);
+ shinfo = skb_shinfo(skb);
+ atomic_set(&shinfo->dataref, 1);
+ shinfo->nr_frags = 0;
+ shinfo->gso_size = 0;
+ shinfo->gso_segs = 0;
+ shinfo->gso_type = 0;
+ shinfo->ip6_frag_id = 0;
+ shinfo->frag_list = NULL;
+
+ memset(skb, 0, offsetof(struct sk_buff, tail));
+ skb->data = skb->head + NET_SKB_PAD;
+ skb_reset_tail_pointer(skb);
+
+ return 1;
+}
+EXPORT_SYMBOL(skb_recycle_check);
+
static void __copy_skb_header(struct sk_buff *new, const struct sk_buff *old)
{
new->tstamp = old->tstamp;
new->network_header = old->network_header;
new->mac_header = old->mac_header;
new->dst = dst_clone(old->dst);
-#ifdef CONFIG_INET
+#ifdef CONFIG_XFRM
new->sp = secpath_get(old->sp);
#endif
memcpy(new->cb, old->cb, sizeof(old->cb));
new->tc_verd = old->tc_verd;
#endif
#endif
+ new->vlan_tci = old->vlan_tci;
+
skb_copy_secmark(new, old);
}
C(head);
C(data);
C(truesize);
+#if defined(CONFIG_MAC80211) || defined(CONFIG_MAC80211_MODULE)
+ C(do_not_encrypt);
+ C(requeue);
+#endif
atomic_set(&n->users, 1);
atomic_inc(&(skb_shinfo(skb)->dataref));
#endif
long off;
+ BUG_ON(nhead < 0);
+
if (skb_shared(skb))
BUG();
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.
*/
for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
int end;
- BUG_TRAP(start <= offset + len);
+ WARN_ON(start > offset + len);
end = start + skb_shinfo(skb)->frags[i].size;
if ((copy = end - offset) > 0) {
for (; list; list = list->next) {
int end;
- BUG_TRAP(start <= offset + len);
+ WARN_ON(start > offset + len);
end = start + list->len;
if ((copy = end - offset) > 0) {
return 0;
}
-/*
- * Map linear and fragment data from the skb to spd. Returns number of
- * pages mapped.
- */
-static int __skb_splice_bits(struct sk_buff *skb, unsigned int *offset,
- unsigned int *total_len,
- struct splice_pipe_desc *spd)
+static inline void __segment_seek(struct page **page, unsigned int *poff,
+ unsigned int *plen, unsigned int off)
{
- unsigned int nr_pages = spd->nr_pages;
- unsigned int poff, plen, len, toff, tlen;
- int headlen, seg;
+ *poff += off;
+ *page += *poff / PAGE_SIZE;
+ *poff = *poff % PAGE_SIZE;
+ *plen -= off;
+}
- toff = *offset;
- tlen = *total_len;
- if (!tlen)
- goto err;
+static inline int __splice_segment(struct page *page, unsigned int poff,
+ unsigned int plen, unsigned int *off,
+ unsigned int *len, struct sk_buff *skb,
+ struct splice_pipe_desc *spd)
+{
+ if (!*len)
+ return 1;
- /*
- * if the offset is greater than the linear part, go directly to
- * the fragments.
- */
- headlen = skb_headlen(skb);
- if (toff >= headlen) {
- toff -= headlen;
- goto map_frag;
+ /* skip this segment if already processed */
+ if (*off >= plen) {
+ *off -= plen;
+ return 0;
}
- /*
- * first map the linear region into the pages/partial map, skipping
- * any potential initial offset.
- */
- len = 0;
- while (len < headlen) {
- void *p = skb->data + len;
-
- poff = (unsigned long) p & (PAGE_SIZE - 1);
- plen = min_t(unsigned int, headlen - len, PAGE_SIZE - poff);
- len += plen;
-
- if (toff) {
- if (plen <= toff) {
- toff -= plen;
- continue;
- }
- plen -= toff;
- poff += toff;
- toff = 0;
- }
+ /* ignore any bits we already processed */
+ if (*off) {
+ __segment_seek(&page, &poff, &plen, *off);
+ *off = 0;
+ }
- plen = min(plen, tlen);
- if (!plen)
- break;
+ do {
+ unsigned int flen = min(*len, plen);
- /*
- * 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))
- goto done;
+ /* the linear region may spread across several pages */
+ flen = min_t(unsigned int, flen, PAGE_SIZE - poff);
- tlen -= plen;
- }
+ if (spd_fill_page(spd, page, flen, poff, skb))
+ return 1;
+
+ __segment_seek(&page, &poff, &plen, flen);
+ *len -= flen;
+
+ } while (*len && plen);
+
+ return 0;
+}
+
+/*
+ * Map linear and fragment data from the skb to spd. It reports failure if the
+ * pipe is full or if we already spliced the requested length.
+ */
+static int __skb_splice_bits(struct sk_buff *skb, unsigned int *offset,
+ unsigned int *len,
+ struct splice_pipe_desc *spd)
+{
+ int seg;
+
+ /*
+ * map the linear part
+ */
+ if (__splice_segment(virt_to_page(skb->data),
+ (unsigned long) skb->data & (PAGE_SIZE - 1),
+ skb_headlen(skb),
+ offset, len, skb, spd))
+ return 1;
/*
* then map the fragments
*/
-map_frag:
for (seg = 0; seg < skb_shinfo(skb)->nr_frags; seg++) {
const skb_frag_t *f = &skb_shinfo(skb)->frags[seg];
- plen = f->size;
- poff = f->page_offset;
-
- if (toff) {
- if (plen <= toff) {
- toff -= plen;
- continue;
- }
- plen -= toff;
- poff += toff;
- toff = 0;
- }
-
- plen = min(plen, tlen);
- if (!plen)
- break;
-
- if (spd_fill_page(spd, f->page, plen, poff, skb))
- break;
-
- tlen -= plen;
+ if (__splice_segment(f->page, f->page_offset, f->size,
+ offset, len, skb, spd))
+ return 1;
}
-done:
- if (spd->nr_pages - nr_pages) {
- *offset = 0;
- *total_len = tlen;
- return 0;
- }
-err:
- return 1;
+ return 0;
}
/*
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;
}
skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
int end;
- BUG_TRAP(start <= offset + len);
+ WARN_ON(start > offset + len);
end = start + frag->size;
if ((copy = end - offset) > 0) {
for (; list; list = list->next) {
int end;
- BUG_TRAP(start <= offset + len);
+ WARN_ON(start > offset + len);
end = start + list->len;
if ((copy = end - offset) > 0) {
for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
int end;
- BUG_TRAP(start <= offset + len);
+ WARN_ON(start > offset + len);
end = start + skb_shinfo(skb)->frags[i].size;
if ((copy = end - offset) > 0) {
for (; list; list = list->next) {
int end;
- BUG_TRAP(start <= offset + len);
+ WARN_ON(start > offset + len);
end = start + list->len;
if ((copy = end - offset) > 0) {
for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
int end;
- BUG_TRAP(start <= offset + len);
+ WARN_ON(start > offset + len);
end = start + skb_shinfo(skb)->frags[i].size;
if ((copy = end - offset) > 0) {
__wsum csum2;
int end;
- BUG_TRAP(start <= offset + len);
+ WARN_ON(start > offset + len);
end = start + list->len;
if ((copy = end - offset) > 0) {
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_split_no_header(skb, skb1, len, pos);
}
+/* Shifting from/to a cloned skb is a no-go.
+ *
+ * Caller cannot keep skb_shinfo related pointers past calling here!
+ */
+static int skb_prepare_for_shift(struct sk_buff *skb)
+{
+ return skb_cloned(skb) && pskb_expand_head(skb, 0, 0, GFP_ATOMIC);
+}
+
+/**
+ * skb_shift - Shifts paged data partially from skb to another
+ * @tgt: buffer into which tail data gets added
+ * @skb: buffer from which the paged data comes from
+ * @shiftlen: shift up to this many bytes
+ *
+ * Attempts to shift up to shiftlen worth of bytes, which may be less than
+ * the length of the skb, from tgt to skb. Returns number bytes shifted.
+ * It's up to caller to free skb if everything was shifted.
+ *
+ * If @tgt runs out of frags, the whole operation is aborted.
+ *
+ * Skb cannot include anything else but paged data while tgt is allowed
+ * to have non-paged data as well.
+ *
+ * TODO: full sized shift could be optimized but that would need
+ * specialized skb free'er to handle frags without up-to-date nr_frags.
+ */
+int skb_shift(struct sk_buff *tgt, struct sk_buff *skb, int shiftlen)
+{
+ int from, to, merge, todo;
+ struct skb_frag_struct *fragfrom, *fragto;
+
+ BUG_ON(shiftlen > skb->len);
+ BUG_ON(skb_headlen(skb)); /* Would corrupt stream */
+
+ todo = shiftlen;
+ from = 0;
+ to = skb_shinfo(tgt)->nr_frags;
+ fragfrom = &skb_shinfo(skb)->frags[from];
+
+ /* Actual merge is delayed until the point when we know we can
+ * commit all, so that we don't have to undo partial changes
+ */
+ if (!to ||
+ !skb_can_coalesce(tgt, to, fragfrom->page, fragfrom->page_offset)) {
+ merge = -1;
+ } else {
+ merge = to - 1;
+
+ todo -= fragfrom->size;
+ if (todo < 0) {
+ if (skb_prepare_for_shift(skb) ||
+ skb_prepare_for_shift(tgt))
+ return 0;
+
+ /* All previous frag pointers might be stale! */
+ fragfrom = &skb_shinfo(skb)->frags[from];
+ fragto = &skb_shinfo(tgt)->frags[merge];
+
+ fragto->size += shiftlen;
+ fragfrom->size -= shiftlen;
+ fragfrom->page_offset += shiftlen;
+
+ goto onlymerged;
+ }
+
+ from++;
+ }
+
+ /* Skip full, not-fitting skb to avoid expensive operations */
+ if ((shiftlen == skb->len) &&
+ (skb_shinfo(skb)->nr_frags - from) > (MAX_SKB_FRAGS - to))
+ return 0;
+
+ if (skb_prepare_for_shift(skb) || skb_prepare_for_shift(tgt))
+ return 0;
+
+ while ((todo > 0) && (from < skb_shinfo(skb)->nr_frags)) {
+ if (to == MAX_SKB_FRAGS)
+ return 0;
+
+ fragfrom = &skb_shinfo(skb)->frags[from];
+ fragto = &skb_shinfo(tgt)->frags[to];
+
+ if (todo >= fragfrom->size) {
+ *fragto = *fragfrom;
+ todo -= fragfrom->size;
+ from++;
+ to++;
+
+ } else {
+ get_page(fragfrom->page);
+ fragto->page = fragfrom->page;
+ fragto->page_offset = fragfrom->page_offset;
+ fragto->size = todo;
+
+ fragfrom->page_offset += todo;
+ fragfrom->size -= todo;
+ todo = 0;
+
+ to++;
+ break;
+ }
+ }
+
+ /* Ready to "commit" this state change to tgt */
+ skb_shinfo(tgt)->nr_frags = to;
+
+ if (merge >= 0) {
+ fragfrom = &skb_shinfo(skb)->frags[0];
+ fragto = &skb_shinfo(tgt)->frags[merge];
+
+ fragto->size += fragfrom->size;
+ put_page(fragfrom->page);
+ }
+
+ /* Reposition in the original skb */
+ to = 0;
+ while (from < skb_shinfo(skb)->nr_frags)
+ skb_shinfo(skb)->frags[to++] = skb_shinfo(skb)->frags[from++];
+ skb_shinfo(skb)->nr_frags = to;
+
+ BUG_ON(todo > 0 && !skb_shinfo(skb)->nr_frags);
+
+onlymerged:
+ /* Most likely the tgt won't ever need its checksum anymore, skb on
+ * the other hand might need it if it needs to be resent
+ */
+ tgt->ip_summed = CHECKSUM_PARTIAL;
+ skb->ip_summed = CHECKSUM_PARTIAL;
+
+ /* Yak, is it really working this way? Some helper please? */
+ skb->len -= shiftlen;
+ skb->data_len -= shiftlen;
+ skb->truesize -= shiftlen;
+ tgt->len += shiftlen;
+ tgt->data_len += shiftlen;
+ tgt->truesize += shiftlen;
+
+ return shiftlen;
+}
+
/**
* skb_prepare_seq_read - Prepare a sequential read of skb data
* @skb: the buffer to read
* of bytes already consumed and the next call to
* skb_seq_read() will return the remaining part of the block.
*
- * Note: The size of each block of data returned can be arbitary,
+ * Note 1: The size of each block of data returned can be arbitary,
* this limitation is the cost for zerocopy seqeuental
* reads of potentially non linear data.
*
- * Note: Fragment lists within fragments are not implemented
+ * Note 2: Fragment lists within fragments are not implemented
* at the moment, state->root_skb could be replaced with
* a stack for this purpose.
*/
/**
* 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)
{
struct sk_buff *segs = NULL;
struct sk_buff *tail = NULL;
+ struct sk_buff *fskb = skb_shinfo(skb)->frag_list;
unsigned int mss = skb_shinfo(skb)->gso_size;
unsigned int doffset = skb->data - skb_mac_header(skb);
unsigned int offset = doffset;
struct sk_buff *nskb;
skb_frag_t *frag;
int hsize;
- int k;
int size;
len = skb->len - offset;
if (hsize > len || !sg)
hsize = len;
- nskb = alloc_skb(hsize + doffset + headroom, GFP_ATOMIC);
- if (unlikely(!nskb))
- goto err;
+ if (!hsize && i >= nfrags) {
+ BUG_ON(fskb->len != len);
+
+ pos += len;
+ nskb = skb_clone(fskb, GFP_ATOMIC);
+ fskb = fskb->next;
+
+ if (unlikely(!nskb))
+ goto err;
+
+ hsize = skb_end_pointer(nskb) - nskb->head;
+ if (skb_cow_head(nskb, doffset + headroom)) {
+ kfree_skb(nskb);
+ goto err;
+ }
+
+ nskb->truesize += skb_end_pointer(nskb) - nskb->head -
+ hsize;
+ skb_release_head_state(nskb);
+ __skb_push(nskb, doffset);
+ } else {
+ nskb = alloc_skb(hsize + doffset + headroom,
+ GFP_ATOMIC);
+
+ if (unlikely(!nskb))
+ goto err;
+
+ skb_reserve(nskb, headroom);
+ __skb_put(nskb, doffset);
+ }
if (segs)
tail->next = nskb;
segs = nskb;
tail = nskb;
- nskb->dev = skb->dev;
- skb_copy_queue_mapping(nskb, skb);
- nskb->priority = skb->priority;
- nskb->protocol = skb->protocol;
- nskb->dst = dst_clone(skb->dst);
- memcpy(nskb->cb, skb->cb, sizeof(skb->cb));
- nskb->pkt_type = skb->pkt_type;
+ __copy_skb_header(nskb, skb);
nskb->mac_len = skb->mac_len;
- skb_reserve(nskb, headroom);
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);
+ skb_copy_from_linear_data(skb, nskb->data, doffset);
+
+ if (pos >= offset + len)
+ continue;
+
if (!sg) {
+ nskb->ip_summed = CHECKSUM_NONE;
nskb->csum = skb_copy_and_csum_bits(skb, offset,
skb_put(nskb, len),
len, 0);
}
frag = skb_shinfo(nskb)->frags;
- k = 0;
- nskb->ip_summed = CHECKSUM_PARTIAL;
- nskb->csum = skb->csum;
skb_copy_from_linear_data_offset(skb, offset,
skb_put(nskb, hsize), hsize);
- while (pos < offset + len) {
- BUG_ON(i >= nfrags);
-
+ while (pos < offset + len && i < nfrags) {
*frag = skb_shinfo(skb)->frags[i];
get_page(frag->page);
size = frag->size;
frag->size -= offset - pos;
}
- k++;
+ skb_shinfo(nskb)->nr_frags++;
if (pos + size <= offset + len) {
i++;
pos += size;
} else {
frag->size -= pos + size - (offset + len);
- break;
+ goto skip_fraglist;
}
frag++;
}
- skb_shinfo(nskb)->nr_frags = k;
+ if (pos < offset + len) {
+ struct sk_buff *fskb2 = fskb;
+
+ BUG_ON(pos + fskb->len != offset + len);
+
+ pos += fskb->len;
+ fskb = fskb->next;
+
+ if (fskb2->next) {
+ fskb2 = skb_clone(fskb2, GFP_ATOMIC);
+ if (!fskb2)
+ goto err;
+ } else
+ skb_get(fskb2);
+
+ BUG_ON(skb_shinfo(nskb)->frag_list);
+ skb_shinfo(nskb)->frag_list = fskb2;
+ }
+
+skip_fraglist:
nskb->data_len = len - hsize;
nskb->len += nskb->data_len;
nskb->truesize += nskb->data_len;
EXPORT_SYMBOL_GPL(skb_segment);
+int skb_gro_receive(struct sk_buff **head, struct sk_buff *skb)
+{
+ struct sk_buff *p = *head;
+ struct sk_buff *nskb;
+ unsigned int headroom;
+ unsigned int hlen = p->data - skb_mac_header(p);
+
+ if (hlen + p->len + skb->len >= 65536)
+ return -E2BIG;
+
+ if (skb_shinfo(p)->frag_list)
+ goto merge;
+
+ headroom = skb_headroom(p);
+ nskb = netdev_alloc_skb(p->dev, headroom);
+ if (unlikely(!nskb))
+ return -ENOMEM;
+
+ __copy_skb_header(nskb, p);
+ nskb->mac_len = p->mac_len;
+
+ skb_reserve(nskb, headroom);
+
+ skb_set_mac_header(nskb, -hlen);
+ skb_set_network_header(nskb, skb_network_offset(p));
+ skb_set_transport_header(nskb, skb_transport_offset(p));
+
+ memcpy(skb_mac_header(nskb), skb_mac_header(p), hlen);
+
+ *NAPI_GRO_CB(nskb) = *NAPI_GRO_CB(p);
+ skb_shinfo(nskb)->frag_list = p;
+ skb_header_release(p);
+ nskb->prev = p;
+
+ nskb->data_len += p->len;
+ nskb->truesize += p->len;
+ nskb->len += p->len;
+
+ *head = nskb;
+ nskb->next = p->next;
+ p->next = NULL;
+
+ p = nskb;
+
+merge:
+ NAPI_GRO_CB(p)->count++;
+ p->prev->next = skb;
+ p->prev = skb;
+ skb_header_release(skb);
+
+ p->data_len += skb->len;
+ p->truesize += skb->len;
+ p->len += skb->len;
+
+ NAPI_GRO_CB(skb)->same_flow = 1;
+ return 0;
+}
+EXPORT_SYMBOL_GPL(skb_gro_receive);
+
void __init skb_init(void)
{
skbuff_head_cache = kmem_cache_create("skbuff_head_cache",
for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
int end;
- BUG_TRAP(start <= offset + len);
+ WARN_ON(start > offset + len);
end = start + skb_shinfo(skb)->frags[i].size;
if ((copy = end - offset) > 0) {
for (; list; list = list->next) {
int end;
- BUG_TRAP(start <= offset + len);
+ WARN_ON(start > offset + len);
end = start + list->len;
if ((copy = end - offset) > 0) {
return elt;
}
+/**
+ * skb_partial_csum_set - set up and verify partial csum values for packet
+ * @skb: the skb to set
+ * @start: the number of bytes after skb->data to start checksumming.
+ * @off: the offset from start to place the checksum.
+ *
+ * For untrusted partially-checksummed packets, we need to make sure the values
+ * for skb->csum_start and skb->csum_offset are valid so we don't oops.
+ *
+ * This function checks and sets those values and skb->ip_summed: if this
+ * returns false you should drop the packet.
+ */
+bool skb_partial_csum_set(struct sk_buff *skb, u16 start, u16 off)
+{
+ if (unlikely(start > skb->len - 2) ||
+ unlikely((int)start + off > skb->len - 2)) {
+ if (net_ratelimit())
+ printk(KERN_WARNING
+ "bad partial csum: csum=%u/%u len=%u\n",
+ start, off, skb->len);
+ return false;
+ }
+ skb->ip_summed = CHECKSUM_PARTIAL;
+ skb->csum_start = skb_headroom(skb) + start;
+ skb->csum_offset = off;
+ return true;
+}
+
+void __skb_warn_lro_forwarding(const struct sk_buff *skb)
+{
+ if (net_ratelimit())
+ pr_warning("%s: received packets cannot be forwarded"
+ " while LRO is enabled\n", skb->dev->name);
+}
+
EXPORT_SYMBOL(___pskb_trim);
EXPORT_SYMBOL(__kfree_skb);
EXPORT_SYMBOL(kfree_skb);
EXPORT_SYMBOL(skb_abort_seq_read);
EXPORT_SYMBOL(skb_find_text);
EXPORT_SYMBOL(skb_append_datato_frags);
+EXPORT_SYMBOL(__skb_warn_lro_forwarding);
EXPORT_SYMBOL_GPL(skb_to_sgvec);
EXPORT_SYMBOL_GPL(skb_cow_data);
+EXPORT_SYMBOL_GPL(skb_partial_csum_set);
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff