[PATCH 2/5] AF_RXRPC: Move generic skbuff stuff from XFRM code to generic code [try #3]

2007-03-20 Thread David Howells
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 <[EMAIL PROTECTED]>
---

 include/linux/skbuff.h |6 ++
 include/net/esp.h  |2 -
 net/core/skbuff.c  |  188 
 net/xfrm/xfrm_algo.c   |  169 ---
 4 files changed, 194 insertions(+), 171 deletions(-)

diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 4ff3940..9e70270 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -83,6 +83,7 @@
  */
 
 struct net_device;
+struct scatterlist;
 
 #ifdef CONFIG_NETFILTER
 struct nf_conntrack {
@@ -363,6 +364,11 @@ extern struct sk_buff *skb_realloc_headroom(struct sk_buff 
*skb,
 extern struct sk_buff *skb_copy_expand(const struct sk_buff *skb,
   int newheadroom, int newtailroom,
   gfp_t priority);
+extern intskb_to_sgvec(struct sk_buff *skb,
+   struct scatterlist *sg, int offset,
+   int len);
+extern intskb_cow_data(struct sk_buff *skb, int tailbits,
+   struct sk_buff **trailer);
 extern intskb_pad(struct sk_buff *skb, int pad);
 #define dev_kfree_skb(a)   kfree_skb(a)
 extern void  skb_over_panic(struct sk_buff *skb, int len,
diff --git a/include/net/esp.h b/include/net/esp.h
index 713d039..d05d8d2 100644
--- a/include/net/esp.h
+++ b/include/net/esp.h
@@ -40,8 +40,6 @@ struct esp_data
} auth;
 };
 
-extern int skb_to_sgvec(struct sk_buff *skb, struct scatterlist *sg, int 
offset, int len);
-extern int skb_cow_data(struct sk_buff *skb, int tailbits, struct sk_buff 
**trailer);
 extern void *pskb_put(struct sk_buff *skb, struct sk_buff *tail, int len);
 
 static inline int esp_mac_digest(struct esp_data *esp, struct sk_buff *skb,
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 702fa8f..f3ed31b 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -55,6 +55,7 @@
 #include 
 #include 
 #include 
+#include 
 
 #include 
 #include 
@@ -2060,6 +2061,190 @@ void __init skb_init(void)
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;
+ 

Re: [PATCH 2/5] AF_RXRPC: Move generic skbuff stuff from XFRM code to generic code [try #2]

2007-03-16 Thread Christoph Hellwig
On Fri, Mar 16, 2007 at 12:50:21PM +, David Howells wrote:
> Move generic skbuff stuff from XFRM code to generic code so that AF_RXRPC can
> use it too.
> 
> Signed-Off-By: David Howells <[EMAIL PROTECTED]>
> ---
> 
>  include/linux/skbuff.h |4 +
>  include/net/esp.h  |2 -
>  net/core/skbuff.c  |  173 
> 
>  net/xfrm/xfrm_algo.c   |  169 ---
>  4 files changed, 177 insertions(+), 171 deletions(-)

> --- a/include/linux/skbuff.h
> +++ b/include/linux/skbuff.h
> @@ -1481,5 +1481,9 @@ static inline int skb_is_gso(const struct sk_buff *skb)
>   return skb_shinfo(skb)->gso_size;
>  }
>  
> +struct scatterlist;

normally we try to put structure forward declarations at the top of the
header instead of spreading it around all over.

> +extern int skb_to_sgvec(struct sk_buff *skb, struct scatterlist *sg, int 
> offset, int len);
> +extern int skb_cow_data(struct sk_buff *skb, int tailbits, struct sk_buff 
> **trailer);

please make sure no line is longer than 80 characters.  Also shouldn't
prototypes normally be above inlines?  Or at least grouped into logical
areas?

> +/*
> + * fill a scatter-gather list with pointers into a part of a socket buffer
> + * chain
> + */

This could probably use a kdoc comment now that it's a public symbol.

> +/*
> + * 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.
> + */

Same here.
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[PATCH 2/5] AF_RXRPC: Move generic skbuff stuff from XFRM code to generic code [try #2]

2007-03-16 Thread David Howells
Move generic skbuff stuff from XFRM code to generic code so that AF_RXRPC can
use it too.

Signed-Off-By: David Howells <[EMAIL PROTECTED]>
---

 include/linux/skbuff.h |4 +
 include/net/esp.h  |2 -
 net/core/skbuff.c  |  173 
 net/xfrm/xfrm_algo.c   |  169 ---
 4 files changed, 177 insertions(+), 171 deletions(-)

diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 4ff3940..8701b12 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -1481,5 +1481,9 @@ static inline int skb_is_gso(const struct sk_buff *skb)
return skb_shinfo(skb)->gso_size;
 }
 
+struct scatterlist;
+extern int skb_to_sgvec(struct sk_buff *skb, struct scatterlist *sg, int 
offset, int len);
+extern int skb_cow_data(struct sk_buff *skb, int tailbits, struct sk_buff 
**trailer);
+
 #endif /* __KERNEL__ */
 #endif /* _LINUX_SKBUFF_H */
diff --git a/include/net/esp.h b/include/net/esp.h
index 713d039..d05d8d2 100644
--- a/include/net/esp.h
+++ b/include/net/esp.h
@@ -40,8 +40,6 @@ struct esp_data
} auth;
 };
 
-extern int skb_to_sgvec(struct sk_buff *skb, struct scatterlist *sg, int 
offset, int len);
-extern int skb_cow_data(struct sk_buff *skb, int tailbits, struct sk_buff 
**trailer);
 extern void *pskb_put(struct sk_buff *skb, struct sk_buff *tail, int len);
 
 static inline int esp_mac_digest(struct esp_data *esp, struct sk_buff *skb,
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 820761f..a70c152 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -55,6 +55,7 @@
 #include 
 #include 
 #include 
+#include 
 
 #include 
 #include 
@@ -2059,6 +2060,175 @@ void __init skb_init(void)
NULL, NULL);
 }
 
+/*
+ * fill a scatter-gather list with pointers into a part of a socket buffer
+ * chain
+ */
+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;
+}
+
+/*
+ * 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)

[PATCH 2/5] AF_RXRPC: Move generic skbuff stuff from XFRM code to generic code

2007-03-08 Thread David Howells
Move generic skbuff stuff from XFRM code to generic code so that AF_RXRPC can
use it too.

Signed-Off-By: David Howells <[EMAIL PROTECTED]>
---

 include/linux/skbuff.h |4 +
 include/net/esp.h  |2 -
 net/core/skbuff.c  |  173 
 net/xfrm/xfrm_algo.c   |  169 ---
 4 files changed, 177 insertions(+), 171 deletions(-)

diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 4ff3940..8701b12 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -1481,5 +1481,9 @@ static inline int skb_is_gso(const struct sk_buff *skb)
return skb_shinfo(skb)->gso_size;
 }
 
+struct scatterlist;
+extern int skb_to_sgvec(struct sk_buff *skb, struct scatterlist *sg, int 
offset, int len);
+extern int skb_cow_data(struct sk_buff *skb, int tailbits, struct sk_buff 
**trailer);
+
 #endif /* __KERNEL__ */
 #endif /* _LINUX_SKBUFF_H */
diff --git a/include/net/esp.h b/include/net/esp.h
index 713d039..d05d8d2 100644
--- a/include/net/esp.h
+++ b/include/net/esp.h
@@ -40,8 +40,6 @@ struct esp_data
} auth;
 };
 
-extern int skb_to_sgvec(struct sk_buff *skb, struct scatterlist *sg, int 
offset, int len);
-extern int skb_cow_data(struct sk_buff *skb, int tailbits, struct sk_buff 
**trailer);
 extern void *pskb_put(struct sk_buff *skb, struct sk_buff *tail, int len);
 
 static inline int esp_mac_digest(struct esp_data *esp, struct sk_buff *skb,
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 820761f..a70c152 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -55,6 +55,7 @@
 #include 
 #include 
 #include 
+#include 
 
 #include 
 #include 
@@ -2059,6 +2060,175 @@ void __init skb_init(void)
NULL, NULL);
 }
 
+/*
+ * fill a scatter-gather list with pointers into a part of a socket buffer
+ * chain
+ */
+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;
+}
+
+/*
+ * 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)