#include <linux/cache.h>
#include <linux/rtnetlink.h>
#include <linux/init.h>
+#include <linux/scatterlist.h>
#include <net/protocol.h>
#include <net/dst.h>
if (atomic_dec_and_test(fclone_ref))
kmem_cache_free(skbuff_fclone_cache, other);
break;
- };
+ }
}
/**
n->tc_verd = CLR_TC_MUNGED(n->tc_verd);
C(iif);
#endif
- skb_copy_secmark(n, skb);
#endif
+ skb_copy_secmark(n, skb);
C(truesize);
atomic_set(&n->users, 1);
C(head);
/* 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;
/* Copy only real data... and, alas, header. This should be
* optimized for the cases when header is void. */
- memcpy(data + nhead, skb->head,
#ifdef NET_SKBUFF_DATA_USES_OFFSET
- skb->tail);
+ memcpy(data + nhead, skb->head, skb->tail);
#else
- skb->tail - skb->head);
+ memcpy(data + nhead, skb->head, skb->tail - skb->head);
#endif
memcpy(data + size, skb_end_pointer(skb),
sizeof(struct skb_shared_info));
skb->data += 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;
-#endif
skb->cloned = 0;
skb->nohdr = 0;
atomic_set(&skb_shinfo(skb)->dataref, 1);
*/
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;
/* 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;
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;
}
if ((copy = start - 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;
* 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);
if ((copy = start - 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;
long csstart;
if (skb->ip_summed == CHECKSUM_PARTIAL)
- csstart = skb_transport_offset(skb);
+ 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)
{
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];
st->stepped_offset += frag->size;
}
+ if (st->frag_data) {
+ kunmap_skb_frag(st->frag_data);
+ st->frag_data = NULL;
+ }
+
if (st->cur_skb->next) {
st->cur_skb = st->cur_skb->next;
st->frag_idx = 0;
skb_set_network_header(nskb, skb->mac_len);
nskb->transport_header = (nskb->network_header +
skb_network_header_len(skb));
- memcpy(skb_put(nskb, doffset), skb->data, doffset);
-
+ 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),
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);
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 start = skb_headlen(skb);
+ int i, copy = start - 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++) {
+ int end;
+
+ BUG_TRAP(start <= offset + len);
+
+ end = start + 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+offset-start;
+ sg[elt].length = copy;
+ elt++;
+ if (!(len -= copy))
+ return elt;
+ offset += 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);
+
+ end = start + list->len;
+ if ((copy = end - offset) > 0) {
+ if (copy > len)
+ copy = len;
+ elt += skb_to_sgvec(list, sg+elt, offset - start, copy);
+ if ((len -= copy) == 0)
+ return elt;
+ offset += copy;
+ }
+ start = end;
+ }
+ }
+ 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);
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);
git.samba.org / sfrench / cifs-2.6.git / blobdiff