[RFC PATCH 04/12] sockets: allow allocating skb with optional structures

Patrick Ohly
2008-12-15T14:57:13Z

The internal sock_alloc_send_pskb() is now exposed
as sock_alloc_send_skb_flags() and takes a flags
parameter with additional instructions for how the
skb is to be allocated. This is necessary for adding
send time stamping information to outgoing packets.

sock_alloc_send_skb() is turned into a simple wrapper
which preserves compatibility with code that
passes a boolean "nblock" instead of the flags
bitmask.

sock_alloc_send_pskb() was never called with non-zero
data_len, therefore the obsolete code and parameter
were removed.

Signed-off-by: Patrick Ohly <patrick.ohly@intel.com>
---
include/net/sock.h | 17 +++++++++++++----
net/core/sock.c | 50 +++++++-------------------------------------------
2 files changed, 20 insertions(+), 47 deletions(-)

diff --git a/include/net/sock.h b/include/net/sock.h
index 36807e4..6cb120c 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -948,10 +948,19 @@ extern int sock_setsockopt(struct socket *sock, int level,
extern int sock_getsockopt(struct socket *sock, int level,
int op, char __user *optval,
int __user *optlen);
-extern struct sk_buff *sock_alloc_send_skb(struct sock *sk,
- unsigned long size,
- int noblock,
- int *errcode);
+extern struct sk_buff *sock_alloc_send_skb_flags(struct sock *sk,
+ unsigned long size,
+ int flags,
+ int *errcode);
+inline static struct sk_buff *sock_alloc_send_skb(struct sock *sk,
+ unsigned long size,
+ int noblock,
+ int *errcode)
+{
+ return sock_alloc_send_skb_flags(sk, size,
+ noblock ? SKB_FLAGS_NOBLOCK : 0,
+ errcode);
+}
extern void *sock_kmalloc(struct sock *sk, int size,
gfp_t priority);
extern void sock_kfree_s(struct sock *sk, void *mem, int size);
diff --git a/net/core/sock.c b/net/core/sock.c
index 35b4f4c..64f959e 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -1304,10 +1304,9 @@ static long sock_wait_for_wmem(struct sock * sk, long timeo)
* Generic send/receive buffer handlers
*/

-static struct sk_buff *sock_alloc_send_pskb(struct sock *sk,
+struct sk_buff *sock_alloc_send_skb_flags(struct sock *sk,
unsigned long header_len,
- unsigned long data_len,
- int noblock, int *errcode)
+ int flags, int *errcode)
{
struct sk_buff *skb;
gfp_t gfp_mask;
@@ -1318,7 +1317,9 @@ static struct sk_buff *sock_alloc_send_pskb(struct sock *sk,
if (gfp_mask & __GFP_WAIT)
gfp_mask |= __GFP_REPEAT;

- timeo = sock_sndtimeo(sk, noblock);
+ timeo = sock_sndtimeo(sk,
+ (flags & SKB_FLAGS_NOBLOCK) ?
+ MSG_DONTWAIT : 0);
while (1) {
err = sock_error(sk);
if (err != 0)
@@ -1329,39 +1330,8 @@ static struct sk_buff *sock_alloc_send_pskb(struct sock *sk,
goto failure;

if (atomic_read(&sk->sk_wmem_alloc) < sk->sk_sndbuf) {
- skb = alloc_skb(header_len, gfp_mask);
+ skb = __alloc_skb_flags(header_len, gfp_mask, flags, -1);
if (skb) {
- int npages;
- int i;
-
- /* No pages, we're done... */
- if (!data_len)
- break;
-
- npages = (data_len + (PAGE_SIZE - 1)) >> PAGE_SHIFT;
- skb->truesize += data_len;
- skb_shinfo(skb)->nr_frags = npages;
- for (i = 0; i < npages; i++) {
- struct page *page;
- skb_frag_t *frag;
-
- page = alloc_pages(sk->sk_allocation, 0);
- if (!page) {
- err = -ENOBUFS;
- skb_shinfo(skb)->nr_frags = i;
- kfree_skb(skb);
- goto failure;
- }
-
- frag = &skb_shinfo(skb)->frags[i];
- frag->page = page;
- frag->page_offset = 0;
- frag->size = (data_len >= PAGE_SIZE ?
- PAGE_SIZE :
- data_len);
- data_len -= PAGE_SIZE;
- }
-
/* Full success... */
break;
}
@@ -1388,12 +1358,6 @@ failure:
return NULL;
}

-struct sk_buff *sock_alloc_send_skb(struct sock *sk, unsigned long size,
- int noblock, int *errcode)
-{
- return sock_alloc_send_pskb(sk, size, 0, noblock, errcode);
-}
-
static void __lock_sock(struct sock *sk)
{
DEFINE_WAIT(wait);
@@ -2327,7 +2291,7 @@ subsys_initcall(proto_init);
EXPORT_SYMBOL(sk_alloc);
EXPORT_SYMBOL(sk_free);
EXPORT_SYMBOL(sk_send_sigurg);
-EXPORT_SYMBOL(sock_alloc_send_skb);
+EXPORT_SYMBOL(sock_alloc_send_skb_flags);
EXPORT_SYMBOL(sock_init_data);
EXPORT_SYMBOL(sock_kfree_s);
EXPORT_SYMBOL(sock_kmalloc);
--
1.5.5.3