From 716ea3a7aae3a2bfc44cb97b5419c1c9868c7bc9 Mon Sep 17 00:00:00 2001 From: David Howells Date: Mon, 2 Apr 2007 20:19:53 -0700 Subject: [NET]: Move generic skbuff stuff from XFRM code to generic code Move generic skbuff stuff from XFRM code to generic code so that AF_RXRPC can use it too. The kdoc comments I've attached to the functions needs to be checked by whoever wrote them as I had to make some guesses about the workings of these functions. Signed-off-By: David Howells Signed-off-by: David S. Miller --- net/xfrm/xfrm_algo.c | 169 --------------------------------------------------- 1 file changed, 169 deletions(-) (limited to 'net/xfrm') diff --git a/net/xfrm/xfrm_algo.c b/net/xfrm/xfrm_algo.c index f373a8a7d9c8..6249a9405bb8 100644 --- a/net/xfrm/xfrm_algo.c +++ b/net/xfrm/xfrm_algo.c @@ -612,175 +612,6 @@ EXPORT_SYMBOL_GPL(skb_icv_walk); #if defined(CONFIG_INET_ESP) || defined(CONFIG_INET_ESP_MODULE) || defined(CONFIG_INET6_ESP) || defined(CONFIG_INET6_ESP_MODULE) -/* Looking generic it is not used in another places. */ - -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; -} -EXPORT_SYMBOL_GPL(skb_to_sgvec); - -/* Check that skb data bits are writable. If they are not, copy data - * to newly created private area. If "tailbits" is given, make sure that - * tailbits bytes beyond current end of skb are writable. - * - * Returns amount of elements of scatterlist to load for subsequent - * transformations and pointer to writable trailer skb. - */ - -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_GPL(skb_cow_data); - void *pskb_put(struct sk_buff *skb, struct sk_buff *tail, int len) { if (tail != skb) { -- cgit v1.2.3-59-g8ed1b