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authorPavel Emelyanov <xemul@parallels.com>2012-02-21 07:31:34 +0000
committerDavid S. Miller <davem@davemloft.net>2012-02-21 15:03:48 -0500
commitef64a54f6e558155b4f149bb10666b9e914b6c54 (patch)
treebd7adba8d802aff2aaec0f5f2a9e2ba5431cafcc /include
parentda5ef6e51b327b41180b5d1000c06e8d3595a936 (diff)
downloadop-kernel-dev-ef64a54f6e558155b4f149bb10666b9e914b6c54.zip
op-kernel-dev-ef64a54f6e558155b4f149bb10666b9e914b6c54.tar.gz
sock: Introduce the SO_PEEK_OFF sock option
This one specifies where to start MSG_PEEK-ing queue data from. When set to negative value means that MSG_PEEK works as ususally -- peeks from the head of the queue always. When some bytes are peeked from queue and the peeking offset is non negative it is moved forward so that the next peek will return next portion of data. When non-peeking recvmsg occurs and the peeking offset is non negative is is moved backward so that the next peek will still peek the proper data (i.e. the one that would have been picked if there were no non peeking recv in between). The offset is set using per-proto opteration to let the protocol handle the locking issues and to check whether the peeking offset feature is supported by the protocol the socket belongs to. Signed-off-by: Pavel Emelyanov <xemul@parallels.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include')
-rw-r--r--include/asm-generic/socket.h1
-rw-r--r--include/linux/net.h1
-rw-r--r--include/net/sock.h25
3 files changed, 27 insertions, 0 deletions
diff --git a/include/asm-generic/socket.h b/include/asm-generic/socket.h
index 49c1704..d9aaac0 100644
--- a/include/asm-generic/socket.h
+++ b/include/asm-generic/socket.h
@@ -67,4 +67,5 @@
#define SO_WIFI_STATUS 41
#define SCM_WIFI_STATUS SO_WIFI_STATUS
+#define SO_PEEK_OFF 42
#endif /* __ASM_GENERIC_SOCKET_H */
diff --git a/include/linux/net.h b/include/linux/net.h
index b299230..be60c7f 100644
--- a/include/linux/net.h
+++ b/include/linux/net.h
@@ -206,6 +206,7 @@ struct proto_ops {
int offset, size_t size, int flags);
ssize_t (*splice_read)(struct socket *sock, loff_t *ppos,
struct pipe_inode_info *pipe, size_t len, unsigned int flags);
+ void (*set_peek_off)(struct sock *sk, int val);
};
#define DECLARE_SOCKADDR(type, dst, src) \
diff --git a/include/net/sock.h b/include/net/sock.h
index 91c1c8b..9c0553b 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -357,6 +357,7 @@ struct sock {
struct page *sk_sndmsg_page;
struct sk_buff *sk_send_head;
__u32 sk_sndmsg_off;
+ __s32 sk_peek_off;
int sk_write_pending;
#ifdef CONFIG_SECURITY
void *sk_security;
@@ -373,6 +374,30 @@ struct sock {
void (*sk_destruct)(struct sock *sk);
};
+static inline int sk_peek_offset(struct sock *sk, int flags)
+{
+ if ((flags & MSG_PEEK) && (sk->sk_peek_off >= 0))
+ return sk->sk_peek_off;
+ else
+ return 0;
+}
+
+static inline void sk_peek_offset_bwd(struct sock *sk, int val)
+{
+ if (sk->sk_peek_off >= 0) {
+ if (sk->sk_peek_off >= val)
+ sk->sk_peek_off -= val;
+ else
+ sk->sk_peek_off = 0;
+ }
+}
+
+static inline void sk_peek_offset_fwd(struct sock *sk, int val)
+{
+ if (sk->sk_peek_off >= 0)
+ sk->sk_peek_off += val;
+}
+
/*
* Hashed lists helper routines
*/
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