X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=net%2Fcore%2Fskbuff.c;h=366621610e76d5a91ae72522d38d0b60e3df45d9;hb=96a8e13ed44e380fc2bb6c711d74d5ba698c00b2;hp=da6683f4b31dbf5ddf1a674193819857cfc28a78;hpb=5084205faf45384fff25c4cf77dd5c96279283ad;p=safe%2Fjmp%2Flinux-2.6 diff --git a/net/core/skbuff.c b/net/core/skbuff.c index da6683f..3666216 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -41,7 +41,6 @@ #include #include #include -#include #include #include #include @@ -53,10 +52,11 @@ #endif #include #include +#include #include #include #include -#include +#include #include #include @@ -67,8 +67,44 @@ #include #include -static kmem_cache_t *skbuff_head_cache __read_mostly; -static kmem_cache_t *skbuff_fclone_cache __read_mostly; +#include "kmap_skb.h" + +static struct kmem_cache *skbuff_head_cache __read_mostly; +static struct kmem_cache *skbuff_fclone_cache __read_mostly; + +static void sock_pipe_buf_release(struct pipe_inode_info *pipe, + struct pipe_buffer *buf) +{ + struct sk_buff *skb = (struct sk_buff *) buf->private; + + kfree_skb(skb); +} + +static void sock_pipe_buf_get(struct pipe_inode_info *pipe, + struct pipe_buffer *buf) +{ + struct sk_buff *skb = (struct sk_buff *) buf->private; + + skb_get(skb); +} + +static int sock_pipe_buf_steal(struct pipe_inode_info *pipe, + struct pipe_buffer *buf) +{ + return 1; +} + + +/* Pipe buffer operations for a socket. */ +static struct pipe_buf_operations sock_pipe_buf_ops = { + .can_merge = 0, + .map = generic_pipe_buf_map, + .unmap = generic_pipe_buf_unmap, + .confirm = generic_pipe_buf_confirm, + .release = sock_pipe_buf_release, + .steal = sock_pipe_buf_steal, + .get = sock_pipe_buf_get, +}; /* * Keep out-of-line to prevent kernel bloat. @@ -87,8 +123,9 @@ static kmem_cache_t *skbuff_fclone_cache __read_mostly; void skb_over_panic(struct sk_buff *skb, int sz, void *here) { printk(KERN_EMERG "skb_over_panic: text:%p len:%d put:%d head:%p " - "data:%p tail:%p end:%p dev:%s\n", - here, skb->len, sz, skb->head, skb->data, skb->tail, skb->end, + "data:%p tail:%#lx end:%#lx dev:%s\n", + here, skb->len, sz, skb->head, skb->data, + (unsigned long)skb->tail, (unsigned long)skb->end, skb->dev ? skb->dev->name : ""); BUG(); } @@ -105,8 +142,9 @@ void skb_over_panic(struct sk_buff *skb, int sz, void *here) void skb_under_panic(struct sk_buff *skb, int sz, void *here) { printk(KERN_EMERG "skb_under_panic: text:%p len:%d put:%d head:%p " - "data:%p tail:%p end:%p dev:%s\n", - here, skb->len, sz, skb->head, skb->data, skb->tail, skb->end, + "data:%p tail:%#lx end:%#lx dev:%s\n", + here, skb->len, sz, skb->head, skb->data, + (unsigned long)skb->tail, (unsigned long)skb->end, skb->dev ? skb->dev->name : ""); BUG(); } @@ -131,6 +169,7 @@ EXPORT_SYMBOL(skb_truesize_bug); * @gfp_mask: allocation mask * @fclone: allocate from fclone cache instead of head cache * and allocate a cloned (child) skb + * @node: numa node to allocate memory on * * Allocate a new &sk_buff. The returned buffer has no headroom and a * tail room of size bytes. The object has a reference count of one. @@ -140,9 +179,9 @@ EXPORT_SYMBOL(skb_truesize_bug); * %GFP_ATOMIC. */ struct sk_buff *__alloc_skb(unsigned int size, gfp_t gfp_mask, - int fclone) + int fclone, int node) { - kmem_cache_t *cache; + struct kmem_cache *cache; struct skb_shared_info *shinfo; struct sk_buff *skb; u8 *data; @@ -150,24 +189,28 @@ struct sk_buff *__alloc_skb(unsigned int size, gfp_t gfp_mask, cache = fclone ? skbuff_fclone_cache : skbuff_head_cache; /* Get the HEAD */ - skb = kmem_cache_alloc(cache, gfp_mask & ~__GFP_DMA); + skb = kmem_cache_alloc_node(cache, gfp_mask & ~__GFP_DMA, node); if (!skb) goto out; - /* Get the DATA. Size must match skb_add_mtu(). */ size = SKB_DATA_ALIGN(size); - data = kmalloc_track_caller(size + sizeof(struct skb_shared_info), - gfp_mask); + data = kmalloc_node_track_caller(size + sizeof(struct skb_shared_info), + gfp_mask, node); if (!data) goto nodata; - memset(skb, 0, offsetof(struct sk_buff, truesize)); + /* + * 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); atomic_set(&skb->users, 1); skb->head = data; skb->data = data; - skb->tail = data; - skb->end = data + size; + skb_reset_tail_pointer(skb); + skb->end = skb->tail + size; /* make sure we initialize shinfo sequentially */ shinfo = skb_shinfo(skb); atomic_set(&shinfo->dataref, 1); @@ -196,61 +239,6 @@ nodata: } /** - * alloc_skb_from_cache - allocate a network buffer - * @cp: kmem_cache from which to allocate the data area - * (object size must be big enough for @size bytes + skb overheads) - * @size: size to allocate - * @gfp_mask: allocation mask - * - * Allocate a new &sk_buff. The returned buffer has no headroom and - * tail room of size bytes. The object has a reference count of one. - * The return is the buffer. On a failure the return is %NULL. - * - * Buffers may only be allocated from interrupts using a @gfp_mask of - * %GFP_ATOMIC. - */ -struct sk_buff *alloc_skb_from_cache(kmem_cache_t *cp, - unsigned int size, - gfp_t gfp_mask) -{ - struct sk_buff *skb; - u8 *data; - - /* Get the HEAD */ - skb = kmem_cache_alloc(skbuff_head_cache, - gfp_mask & ~__GFP_DMA); - if (!skb) - goto out; - - /* Get the DATA. */ - size = SKB_DATA_ALIGN(size); - data = kmem_cache_alloc(cp, gfp_mask); - if (!data) - goto nodata; - - memset(skb, 0, offsetof(struct sk_buff, truesize)); - skb->truesize = size + sizeof(struct sk_buff); - atomic_set(&skb->users, 1); - skb->head = data; - skb->data = data; - skb->tail = data; - skb->end = data + size; - - atomic_set(&(skb_shinfo(skb)->dataref), 1); - skb_shinfo(skb)->nr_frags = 0; - skb_shinfo(skb)->gso_size = 0; - skb_shinfo(skb)->gso_segs = 0; - skb_shinfo(skb)->gso_type = 0; - skb_shinfo(skb)->frag_list = NULL; -out: - return skb; -nodata: - kmem_cache_free(skbuff_head_cache, skb); - skb = NULL; - goto out; -} - -/** * __netdev_alloc_skb - allocate an skbuff for rx on a specific device * @dev: network device to receive on * @length: length to allocate @@ -266,9 +254,10 @@ nodata: struct sk_buff *__netdev_alloc_skb(struct net_device *dev, unsigned int length, gfp_t gfp_mask) { + int node = dev->dev.parent ? dev_to_node(dev->dev.parent) : -1; struct sk_buff *skb; - skb = alloc_skb(length + NET_SKB_PAD, gfp_mask); + skb = __alloc_skb(length + NET_SKB_PAD, gfp_mask, 0, node); if (likely(skb)) { skb_reserve(skb, NET_SKB_PAD); skb->dev = dev; @@ -276,6 +265,28 @@ struct sk_buff *__netdev_alloc_skb(struct net_device *dev, 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; @@ -323,12 +334,11 @@ static void skb_release_data(struct sk_buff *skb) /* * Free an skbuff by memory without cleaning the state. */ -void kfree_skbmem(struct sk_buff *skb) +static void kfree_skbmem(struct sk_buff *skb) { struct sk_buff *other; atomic_t *fclone_ref; - skb_release_data(skb); switch (skb->fclone) { case SKB_FCLONE_UNAVAILABLE: kmem_cache_free(skbuff_head_cache, skb); @@ -352,19 +362,11 @@ void kfree_skbmem(struct sk_buff *skb) if (atomic_dec_and_test(fclone_ref)) kmem_cache_free(skbuff_fclone_cache, other); break; - }; + } } -/** - * __kfree_skb - private function - * @skb: buffer - * - * Free an sk_buff. Release anything attached to the buffer. - * Clean the state. This is an internal helper function. Users should - * always call kfree_skb - */ - -void __kfree_skb(struct sk_buff *skb) +/* Free everything but the sk_buff shell. */ +static void skb_release_all(struct sk_buff *skb) { dst_release(skb->dst); #ifdef CONFIG_XFRM @@ -374,15 +376,13 @@ void __kfree_skb(struct sk_buff *skb) WARN_ON(in_irq()); skb->destructor(skb); } -#ifdef CONFIG_NETFILTER - nf_conntrack_put(skb->nfct); #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) + nf_conntrack_put(skb->nfct); nf_conntrack_put_reasm(skb->nfct_reasm); #endif #ifdef CONFIG_BRIDGE_NETFILTER nf_bridge_put(skb->nf_bridge); #endif -#endif /* XXX: IS this still necessary? - JHS */ #ifdef CONFIG_NET_SCHED skb->tc_index = 0; @@ -390,7 +390,21 @@ void __kfree_skb(struct sk_buff *skb) skb->tc_verd = 0; #endif #endif + skb_release_data(skb); +} + +/** + * __kfree_skb - private function + * @skb: buffer + * + * Free an sk_buff. Release anything attached to the buffer. + * Clean the state. This is an internal helper function. Users should + * always call kfree_skb + */ +void __kfree_skb(struct sk_buff *skb) +{ + skb_release_all(skb); kfree_skbmem(skb); } @@ -412,6 +426,91 @@ void kfree_skb(struct sk_buff *skb) __kfree_skb(skb); } +static void __copy_skb_header(struct sk_buff *new, const struct sk_buff *old) +{ + new->tstamp = old->tstamp; + new->dev = old->dev; + new->transport_header = old->transport_header; + new->network_header = old->network_header; + new->mac_header = old->mac_header; + new->dst = dst_clone(old->dst); +#ifdef CONFIG_INET + new->sp = secpath_get(old->sp); +#endif + memcpy(new->cb, old->cb, sizeof(old->cb)); + new->csum_start = old->csum_start; + new->csum_offset = old->csum_offset; + new->local_df = old->local_df; + new->pkt_type = old->pkt_type; + new->ip_summed = old->ip_summed; + skb_copy_queue_mapping(new, old); + new->priority = old->priority; +#if defined(CONFIG_IP_VS) || defined(CONFIG_IP_VS_MODULE) + new->ipvs_property = old->ipvs_property; +#endif + new->protocol = old->protocol; + new->mark = old->mark; + __nf_copy(new, old); +#if defined(CONFIG_NETFILTER_XT_TARGET_TRACE) || \ + defined(CONFIG_NETFILTER_XT_TARGET_TRACE_MODULE) + new->nf_trace = old->nf_trace; +#endif +#ifdef CONFIG_NET_SCHED + new->tc_index = old->tc_index; +#ifdef CONFIG_NET_CLS_ACT + new->tc_verd = old->tc_verd; +#endif +#endif + skb_copy_secmark(new, old); +} + +static struct sk_buff *__skb_clone(struct sk_buff *n, struct sk_buff *skb) +{ +#define C(x) n->x = skb->x + + n->next = n->prev = NULL; + n->sk = NULL; + __copy_skb_header(n, skb); + + C(len); + C(data_len); + C(mac_len); + n->hdr_len = skb->nohdr ? skb_headroom(skb) : skb->hdr_len; + n->cloned = 1; + n->nohdr = 0; + n->destructor = NULL; + C(iif); + C(tail); + C(end); + C(head); + C(data); + C(truesize); + atomic_set(&n->users, 1); + + atomic_inc(&(skb_shinfo(skb)->dataref)); + skb->cloned = 1; + + return n; +#undef C +} + +/** + * skb_morph - morph one skb into another + * @dst: the skb to receive the contents + * @src: the skb to supply the contents + * + * This is identical to skb_clone except that the target skb is + * supplied by the user. + * + * The target skb is returned upon exit. + */ +struct sk_buff *skb_morph(struct sk_buff *dst, struct sk_buff *src) +{ + skb_release_all(dst); + return __skb_clone(dst, src); +} +EXPORT_SYMBOL_GPL(skb_morph); + /** * skb_clone - duplicate an sk_buff * @skb: buffer to clone @@ -443,122 +542,26 @@ struct sk_buff *skb_clone(struct sk_buff *skb, gfp_t gfp_mask) n->fclone = SKB_FCLONE_UNAVAILABLE; } -#define C(x) n->x = skb->x - - n->next = n->prev = NULL; - n->sk = NULL; - C(tstamp); - C(dev); - C(h); - C(nh); - C(mac); - C(dst); - dst_clone(skb->dst); - C(sp); -#ifdef CONFIG_INET - secpath_get(skb->sp); -#endif - memcpy(n->cb, skb->cb, sizeof(skb->cb)); - C(len); - C(data_len); - C(csum); - C(local_df); - n->cloned = 1; - n->nohdr = 0; - C(pkt_type); - C(ip_summed); - C(priority); -#if defined(CONFIG_IP_VS) || defined(CONFIG_IP_VS_MODULE) - C(ipvs_property); -#endif - C(protocol); - n->destructor = NULL; - C(mark); -#ifdef CONFIG_NETFILTER - C(nfct); - nf_conntrack_get(skb->nfct); - C(nfctinfo); -#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) - C(nfct_reasm); - nf_conntrack_get_reasm(skb->nfct_reasm); -#endif -#ifdef CONFIG_BRIDGE_NETFILTER - C(nf_bridge); - nf_bridge_get(skb->nf_bridge); -#endif -#endif /*CONFIG_NETFILTER*/ -#ifdef CONFIG_NET_SCHED - C(tc_index); -#ifdef CONFIG_NET_CLS_ACT - n->tc_verd = SET_TC_VERD(skb->tc_verd,0); - n->tc_verd = CLR_TC_OK2MUNGE(n->tc_verd); - n->tc_verd = CLR_TC_MUNGED(n->tc_verd); - C(input_dev); -#endif - skb_copy_secmark(n, skb); -#endif - C(truesize); - atomic_set(&n->users, 1); - C(head); - C(data); - C(tail); - C(end); - - atomic_inc(&(skb_shinfo(skb)->dataref)); - skb->cloned = 1; - - return n; + return __skb_clone(n, skb); } static void copy_skb_header(struct sk_buff *new, const struct sk_buff *old) { +#ifndef NET_SKBUFF_DATA_USES_OFFSET /* * Shift between the two data areas in bytes */ unsigned long offset = new->data - old->data; - - new->sk = NULL; - new->dev = old->dev; - new->priority = old->priority; - new->protocol = old->protocol; - new->dst = dst_clone(old->dst); -#ifdef CONFIG_INET - new->sp = secpath_get(old->sp); -#endif - new->h.raw = old->h.raw + offset; - new->nh.raw = old->nh.raw + offset; - new->mac.raw = old->mac.raw + offset; - memcpy(new->cb, old->cb, sizeof(old->cb)); - new->local_df = old->local_df; - new->fclone = SKB_FCLONE_UNAVAILABLE; - new->pkt_type = old->pkt_type; - new->tstamp = old->tstamp; - new->destructor = NULL; - new->mark = old->mark; -#ifdef CONFIG_NETFILTER - new->nfct = old->nfct; - nf_conntrack_get(old->nfct); - new->nfctinfo = old->nfctinfo; -#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) - new->nfct_reasm = old->nfct_reasm; - nf_conntrack_get_reasm(old->nfct_reasm); -#endif -#if defined(CONFIG_IP_VS) || defined(CONFIG_IP_VS_MODULE) - new->ipvs_property = old->ipvs_property; -#endif -#ifdef CONFIG_BRIDGE_NETFILTER - new->nf_bridge = old->nf_bridge; - nf_bridge_get(old->nf_bridge); -#endif -#endif -#ifdef CONFIG_NET_SCHED -#ifdef CONFIG_NET_CLS_ACT - new->tc_verd = old->tc_verd; #endif - new->tc_index = old->tc_index; + + __copy_skb_header(new, old); + +#ifndef NET_SKBUFF_DATA_USES_OFFSET + /* {transport,network,mac}_header are relative to skb->head */ + new->transport_header += offset; + new->network_header += offset; + new->mac_header += offset; #endif - skb_copy_secmark(new, old); - atomic_set(&new->users, 1); skb_shinfo(new)->gso_size = skb_shinfo(old)->gso_size; skb_shinfo(new)->gso_segs = skb_shinfo(old)->gso_segs; skb_shinfo(new)->gso_type = skb_shinfo(old)->gso_type; @@ -587,8 +590,12 @@ struct sk_buff *skb_copy(const struct sk_buff *skb, gfp_t gfp_mask) /* * Allocate the copy buffer */ - struct sk_buff *n = alloc_skb(skb->end - skb->head + skb->data_len, - gfp_mask); + struct sk_buff *n; +#ifdef NET_SKBUFF_DATA_USES_OFFSET + n = alloc_skb(skb->end + skb->data_len, gfp_mask); +#else + n = alloc_skb(skb->end - skb->head + skb->data_len, gfp_mask); +#endif if (!n) return NULL; @@ -596,8 +603,6 @@ struct sk_buff *skb_copy(const struct sk_buff *skb, gfp_t gfp_mask) skb_reserve(n, headerlen); /* Set the tail pointer and length */ skb_put(n, skb->len); - n->csum = skb->csum; - n->ip_summed = skb->ip_summed; if (skb_copy_bits(skb, -headerlen, n->head, headerlen + skb->len)) BUG(); @@ -625,8 +630,12 @@ struct sk_buff *pskb_copy(struct sk_buff *skb, gfp_t gfp_mask) /* * Allocate the copy buffer */ - struct sk_buff *n = alloc_skb(skb->end - skb->head, gfp_mask); - + struct sk_buff *n; +#ifdef NET_SKBUFF_DATA_USES_OFFSET + n = alloc_skb(skb->end, gfp_mask); +#else + n = alloc_skb(skb->end - skb->head, gfp_mask); +#endif if (!n) goto out; @@ -635,9 +644,7 @@ struct sk_buff *pskb_copy(struct sk_buff *skb, gfp_t gfp_mask) /* Set the tail pointer and length */ skb_put(n, skb_headlen(skb)); /* Copy the bytes */ - memcpy(n->data, skb->data, n->len); - n->csum = skb->csum; - n->ip_summed = skb->ip_summed; + skb_copy_from_linear_data(skb, n->data, n->len); n->truesize += skb->data_len; n->data_len = skb->data_len; @@ -684,7 +691,11 @@ int pskb_expand_head(struct sk_buff *skb, int nhead, int ntail, { int i; u8 *data; +#ifdef NET_SKBUFF_DATA_USES_OFFSET + int size = nhead + skb->end + ntail; +#else int size = nhead + (skb->end - skb->head) + ntail; +#endif long off; if (skb_shared(skb)) @@ -698,8 +709,13 @@ int pskb_expand_head(struct sk_buff *skb, int nhead, int ntail, /* Copy only real data... and, alas, header. This should be * optimized for the cases when header is void. */ +#ifdef NET_SKBUFF_DATA_USES_OFFSET + memcpy(data + nhead, skb->head, skb->tail); +#else memcpy(data + nhead, skb->head, skb->tail - skb->head); - memcpy(data + size, skb->end, sizeof(struct skb_shared_info)); +#endif + memcpy(data + size, skb_end_pointer(skb), + sizeof(struct skb_shared_info)); for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) get_page(skb_shinfo(skb)->frags[i].page); @@ -712,13 +728,21 @@ int pskb_expand_head(struct sk_buff *skb, int nhead, int ntail, off = (data + nhead) - skb->head; skb->head = data; - skb->end = data + size; skb->data += off; - skb->tail += off; - skb->mac.raw += off; - skb->h.raw += off; - skb->nh.raw += 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; + skb->csum_start += nhead; skb->cloned = 0; + skb->hdr_len = 0; skb->nohdr = 0; atomic_set(&skb_shinfo(skb)->dataref, 1); return 0; @@ -765,9 +789,6 @@ struct sk_buff *skb_realloc_headroom(struct sk_buff *skb, unsigned int headroom) * * You must pass %GFP_ATOMIC as the allocation priority if this function * is called from an interrupt. - * - * BUG ALERT: ip_summed is not copied. Why does this work? Is it used - * only by netfilter in the cases when checksum is recalculated? --ANK */ struct sk_buff *skb_copy_expand(const struct sk_buff *skb, int newheadroom, int newtailroom, @@ -778,7 +799,9 @@ struct sk_buff *skb_copy_expand(const struct sk_buff *skb, */ 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; if (!n) return NULL; @@ -788,7 +811,7 @@ struct sk_buff *skb_copy_expand(const struct sk_buff *skb, /* 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; @@ -802,6 +825,14 @@ struct sk_buff *skb_copy_expand(const struct sk_buff *skb, copy_skb_header(n, skb); + off = newheadroom - oldheadroom; + n->csum_start += off; +#ifdef NET_SKBUFF_DATA_USES_OFFSET + n->transport_header += off; + n->network_header += off; + n->mac_header += off; +#endif + return n; } @@ -816,12 +847,12 @@ struct sk_buff *skb_copy_expand(const struct sk_buff *skb, * * May return error in out of memory cases. The skb is freed on error. */ - + int skb_pad(struct sk_buff *skb, int pad) { int err; int ntail; - + /* If the skbuff is non linear tailroom is always zero.. */ if (!skb_cloned(skb) && skb_tailroom(skb) >= pad) { memset(skb->data+skb->len, 0, pad); @@ -848,8 +879,80 @@ int skb_pad(struct sk_buff *skb, int pad) free_skb: kfree_skb(skb); 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->datahead)) + 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. */ @@ -929,7 +1032,7 @@ done: } else { skb->len = len; skb->data_len = 0; - skb->tail = skb->data + len; + skb_set_tail_pointer(skb, len); } return 0; @@ -974,7 +1077,7 @@ unsigned char *__pskb_pull_tail(struct sk_buff *skb, int delta) return NULL; } - if (skb_copy_bits(skb, skb_headlen(skb), skb->tail, delta)) + if (skb_copy_bits(skb, skb_headlen(skb), skb_tail_pointer(skb), delta)) BUG(); /* Optimization: no fragments, no reasons to preestimate @@ -1070,7 +1173,7 @@ pull_pages: skb->tail += delta; skb->data_len -= delta; - return skb->tail; + return skb_tail_pointer(skb); } /* Copy some data bits from skb to kernel buffer. */ @@ -1087,7 +1190,7 @@ int skb_copy_bits(const struct sk_buff *skb, int offset, void *to, int len) 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; @@ -1150,6 +1253,225 @@ fault: return -EFAULT; } +/* + * Callback from splice_to_pipe(), if we need to release some pages + * at the end of the spd in case we error'ed out in filling the pipe. + */ +static void sock_spd_release(struct splice_pipe_desc *spd, unsigned int i) +{ + struct sk_buff *skb = (struct sk_buff *) spd->partial[i].private; + + kfree_skb(skb); +} + +/* + * Fill page/offset/length into spd, if it can hold more pages. + */ +static inline int spd_fill_page(struct splice_pipe_desc *spd, struct page *page, + unsigned int len, unsigned int offset, + struct sk_buff *skb) +{ + if (unlikely(spd->nr_pages == PIPE_BUFFERS)) + return 1; + + spd->pages[spd->nr_pages] = page; + spd->partial[spd->nr_pages].len = len; + spd->partial[spd->nr_pages].offset = offset; + spd->partial[spd->nr_pages].private = (unsigned long) skb_get(skb); + spd->nr_pages++; + 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) +{ + unsigned int nr_pages = spd->nr_pages; + unsigned int poff, plen, len, toff, tlen; + int headlen, seg, error = 0; + + toff = *offset; + tlen = *total_len; + if (!tlen) { + error = 1; + goto err; + } + + /* + * 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; + } + + /* + * 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; + } + + plen = min(plen, tlen); + if (!plen) + break; + + /* + * just jump directly to update and return, no point + * in going over fragments when the output is full. + */ + error = spd_fill_page(spd, virt_to_page(p), plen, poff, skb); + if (error) + goto done; + + tlen -= plen; + } + + /* + * 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; + + error = spd_fill_page(spd, f->page, plen, poff, skb); + if (error) + break; + + tlen -= plen; + } + +done: + if (spd->nr_pages - nr_pages) { + *offset = 0; + *total_len = tlen; + return 0; + } +err: + /* update the offset to reflect the linear part skip, if any */ + if (!error) + *offset = toff; + return error; +} + +/* + * Map data from the skb to a pipe. Should handle both the linear part, + * the fragments, and the frag list. It does NOT handle frag lists within + * the frag list, if such a thing exists. We'd probably need to recurse to + * handle that cleanly. + */ +int skb_splice_bits(struct sk_buff *__skb, unsigned int offset, + struct pipe_inode_info *pipe, unsigned int tlen, + unsigned int flags) +{ + struct partial_page partial[PIPE_BUFFERS]; + struct page *pages[PIPE_BUFFERS]; + struct splice_pipe_desc spd = { + .pages = pages, + .partial = partial, + .flags = flags, + .ops = &sock_pipe_buf_ops, + .spd_release = sock_spd_release, + }; + struct sk_buff *skb; + + /* + * I'd love to avoid the clone here, but tcp_read_sock() + * ignores reference counts and unconditonally kills the sk_buff + * on return from the actor. + */ + skb = skb_clone(__skb, GFP_KERNEL); + if (unlikely(!skb)) + return -ENOMEM; + + /* + * __skb_splice_bits() only fails if the output has no room left, + * so no point in going over the frag_list for the error case. + */ + if (__skb_splice_bits(skb, &offset, &tlen, &spd)) + goto done; + else if (!tlen) + goto done; + + /* + * now see if we have a frag_list to map + */ + if (skb_shinfo(skb)->frag_list) { + struct sk_buff *list = skb_shinfo(skb)->frag_list; + + for (; list && tlen; list = list->next) { + if (__skb_splice_bits(list, &offset, &tlen, &spd)) + break; + } + } + +done: + /* + * drop our reference to the clone, the pipe consumption will + * drop the rest. + */ + kfree_skb(skb); + + if (spd.nr_pages) { + int ret; + struct sock *sk = __skb->sk; + + /* + * Drop the socket lock, otherwise we have reverse + * locking dependencies between sk_lock and i_mutex + * here as compared to sendfile(). We enter here + * with the socket lock held, and splice_to_pipe() will + * grab the pipe inode lock. For sendfile() emulation, + * we call into ->sendpage() with the i_mutex lock held + * and networking will grab the socket lock. + */ + release_sock(sk); + ret = splice_to_pipe(pipe, &spd); + lock_sock(sk); + return ret; + } + + return 0; +} + /** * skb_store_bits - store bits from kernel buffer to skb * @skb: destination buffer @@ -1162,7 +1484,7 @@ fault: * 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); @@ -1173,7 +1495,7 @@ int skb_store_bits(const struct sk_buff *skb, int offset, void *from, int len) 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; @@ -1240,8 +1562,8 @@ EXPORT_SYMBOL(skb_store_bits); /* Checksum skb data. */ -unsigned int skb_checksum(const struct sk_buff *skb, int offset, - int len, unsigned int csum) +__wsum skb_checksum(const struct sk_buff *skb, int offset, + int len, __wsum csum) { int start = skb_headlen(skb); int i, copy = start - offset; @@ -1294,7 +1616,7 @@ unsigned int skb_checksum(const struct sk_buff *skb, int offset, end = start + list->len; if ((copy = end - offset) > 0) { - unsigned int csum2; + __wsum csum2; if (copy > len) copy = len; csum2 = skb_checksum(list, offset - start, @@ -1315,8 +1637,8 @@ unsigned int skb_checksum(const struct sk_buff *skb, int offset, /* Both of above in one bottle. */ -unsigned int skb_copy_and_csum_bits(const struct sk_buff *skb, int offset, - u8 *to, int len, unsigned int csum) +__wsum skb_copy_and_csum_bits(const struct sk_buff *skb, int offset, + u8 *to, int len, __wsum csum) { int start = skb_headlen(skb); int i, copy = start - offset; @@ -1368,7 +1690,7 @@ unsigned int skb_copy_and_csum_bits(const struct sk_buff *skb, int offset, struct sk_buff *list = skb_shinfo(skb)->frag_list; for (; list; list = list->next) { - unsigned int csum2; + __wsum csum2; int end; BUG_TRAP(start <= offset + len); @@ -1400,13 +1722,13 @@ void skb_copy_and_csum_dev(const struct sk_buff *skb, u8 *to) long csstart; if (skb->ip_summed == CHECKSUM_PARTIAL) - csstart = skb->h.raw - skb->data; + 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) @@ -1414,7 +1736,7 @@ void skb_copy_and_csum_dev(const struct sk_buff *skb, u8 *to) skb->len - csstart, 0); if (skb->ip_summed == CHECKSUM_PARTIAL) { - long csstuff = csstart + skb->csum; + long csstuff = csstart + skb->csum_offset; *((__sum16 *)(to + csstuff)) = csum_fold(csum); } @@ -1548,7 +1870,7 @@ void skb_append(struct sk_buff *old, struct sk_buff *newsk, struct sk_buff_head 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); } @@ -1574,27 +1896,14 @@ void skb_insert(struct sk_buff *old, struct sk_buff *newsk, struct sk_buff_head spin_unlock_irqrestore(&list->lock, flags); } -#if 0 -/* - * Tune the memory allocator for a new MTU size. - */ -void skb_add_mtu(int mtu) -{ - /* Must match allocation in alloc_skb */ - mtu = SKB_DATA_ALIGN(mtu) + sizeof(struct skb_shared_info); - - kmem_add_cache_size(mtu); -} -#endif - static inline void skb_split_inside_header(struct sk_buff *skb, struct sk_buff* skb1, const u32 len, const int pos) { 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]; @@ -1605,7 +1914,7 @@ static inline void skb_split_inside_header(struct sk_buff *skb, skb1->len += skb1->data_len; skb->data_len = 0; skb->len = len; - skb->tail = skb->data + len; + skb_set_tail_pointer(skb, len); } static inline void skb_split_no_header(struct sk_buff *skb, @@ -1702,11 +2011,11 @@ void skb_prepare_seq_read(struct sk_buff *skb, unsigned int from, * 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. */ @@ -1753,6 +2062,11 @@ next_skb: 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; @@ -1896,11 +2210,10 @@ int skb_append_datato_frags(struct sock *sk, struct sk_buff *skb, /** * 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. @@ -1922,15 +2235,15 @@ EXPORT_SYMBOL_GPL(skb_pull_rcsum); * @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; unsigned int mss = skb_shinfo(skb)->gso_size; - unsigned int doffset = skb->data - skb->mac.raw; + unsigned int doffset = skb->data - skb_mac_header(skb); unsigned int offset = doffset; unsigned int headroom; unsigned int len; @@ -1972,6 +2285,7 @@ struct sk_buff *skb_segment(struct sk_buff *skb, int features) 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); @@ -1980,11 +2294,12 @@ struct sk_buff *skb_segment(struct sk_buff *skb, int features) nskb->mac_len = skb->mac_len; skb_reserve(nskb, headroom); - nskb->mac.raw = nskb->data; - nskb->nh.raw = nskb->data + skb->mac_len; - nskb->h.raw = nskb->nh.raw + (skb->h.raw - skb->nh.raw); - memcpy(skb_put(nskb, doffset), skb->data, doffset); - + 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); if (!sg) { nskb->csum = skb_copy_and_csum_bits(skb, offset, skb_put(nskb, len), @@ -1997,7 +2312,8 @@ struct sk_buff *skb_segment(struct sk_buff *skb, int features) 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); @@ -2035,7 +2351,7 @@ struct sk_buff *skb_segment(struct sk_buff *skb, int features) err: while ((skb = segs)) { segs = skb->next; - kfree(skb); + kfree_skb(skb); } return ERR_PTR(err); } @@ -2048,13 +2364,232 @@ void __init skb_init(void) sizeof(struct sk_buff), 0, SLAB_HWCACHE_ALIGN|SLAB_PANIC, - NULL, NULL); + NULL); skbuff_fclone_cache = kmem_cache_create("skbuff_fclone_cache", (2*sizeof(struct sk_buff)) + sizeof(atomic_t), 0, SLAB_HWCACHE_ALIGN|SLAB_PANIC, - NULL, 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. + */ +static 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_set_buf(sg, skb->data + offset, 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_set_page(&sg[elt], frag->page, copy, + frag->page_offset+offset-start); + 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; +} + +int skb_to_sgvec(struct sk_buff *skb, struct scatterlist *sg, int offset, int len) +{ + int nsg = __skb_to_sgvec(skb, sg, offset, len); + + sg_mark_end(&sg[nsg - 1]); + + return nsg; +} + +/** + * 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; +} + +/** + * 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; } EXPORT_SYMBOL(___pskb_trim); @@ -2067,7 +2602,6 @@ EXPORT_SYMBOL(pskb_copy); EXPORT_SYMBOL(pskb_expand_head); EXPORT_SYMBOL(skb_checksum); EXPORT_SYMBOL(skb_clone); -EXPORT_SYMBOL(skb_clone_fraglist); EXPORT_SYMBOL(skb_copy); EXPORT_SYMBOL(skb_copy_and_csum_bits); EXPORT_SYMBOL(skb_copy_and_csum_dev); @@ -2091,3 +2625,7 @@ EXPORT_SYMBOL(skb_seq_read); 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); +EXPORT_SYMBOL_GPL(skb_partial_csum_set);