]> pilppa.org Git - linux-2.6-omap-h63xx.git/blobdiff - net/core/skbuff.c
Merge git://git.kernel.org/pub/scm/linux/kernel/git/sam/kbuild
[linux-2.6-omap-h63xx.git] / net / core / skbuff.c
index 7cfbdb215ba2711cca6c5f8f92c3f0be640989d2..c448c7f6fde2a002b7549076e3c4d98e83a1194c 100644 (file)
@@ -249,12 +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;
@@ -263,6 +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;
@@ -823,41 +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;
@@ -1327,7 +1397,7 @@ void skb_copy_and_csum_dev(const struct sk_buff *skb, u8 *to)
        unsigned int csum;
        long csstart;
 
-       if (skb->ip_summed == CHECKSUM_HW)
+       if (skb->ip_summed == CHECKSUM_PARTIAL)
                csstart = skb->h.raw - skb->data;
        else
                csstart = skb_headlen(skb);
@@ -1341,7 +1411,7 @@ void skb_copy_and_csum_dev(const struct sk_buff *skb, u8 *to)
                csum = skb_copy_and_csum_bits(skb, csstart, to + csstart,
                                              skb->len - csstart, 0);
 
-       if (skb->ip_summed == CHECKSUM_HW) {
+       if (skb->ip_summed == CHECKSUM_PARTIAL) {
                long csstuff = csstart + skb->csum;
 
                *((unsigned short *)(to + csstuff)) = csum_fold(csum);
@@ -1828,10 +1898,10 @@ int skb_append_datato_frags(struct sock *sk, struct sk_buff *skb,
  *     @len: length of data pulled
  *
  *     This function performs an skb_pull on the packet and updates
- *     update the CHECKSUM_HW 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.
+ *     update 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.
  */
 unsigned char *skb_pull_rcsum(struct sk_buff *skb, unsigned int len)
 {
@@ -1924,7 +1994,7 @@ struct sk_buff *skb_segment(struct sk_buff *skb, int features)
                frag = skb_shinfo(nskb)->frags;
                k = 0;
 
-               nskb->ip_summed = CHECKSUM_HW;
+               nskb->ip_summed = CHECKSUM_PARTIAL;
                nskb->csum = skb->csum;
                memcpy(skb_put(nskb, hsize), skb->data + offset, hsize);
 
@@ -1976,19 +2046,14 @@ void __init skb_init(void)
        skbuff_head_cache = kmem_cache_create("skbuff_head_cache",
                                              sizeof(struct sk_buff),
                                              0,
-                                             SLAB_HWCACHE_ALIGN,
+                                             SLAB_HWCACHE_ALIGN|SLAB_PANIC,
                                              NULL, NULL);
-       if (!skbuff_head_cache)
-               panic("cannot create skbuff cache");
-
        skbuff_fclone_cache = kmem_cache_create("skbuff_fclone_cache",
                                                (2*sizeof(struct sk_buff)) +
                                                sizeof(atomic_t),
                                                0,
-                                               SLAB_HWCACHE_ALIGN,
+                                               SLAB_HWCACHE_ALIGN|SLAB_PANIC,
                                                NULL, NULL);
-       if (!skbuff_fclone_cache)
-               panic("cannot create skbuff cache");
 }
 
 EXPORT_SYMBOL(___pskb_trim);
@@ -1996,6 +2061,7 @@ 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);