From: Willem de Bruijn <will...@google.com>
The send call ignores unknown flags. Legacy applications may already
unwittingly pass MSG_ZEROCOPY. Continue to ignore this flag unless a
socket opts in to zerocopy.
Introduce socket option SO_ZEROCOPY to enable MSG_ZEROCOPY processing.
Processes can also query this socket option to detect kernel support
for the feature. Older kernels will return ENOPROTOOPT.
Signed-off-by: Willem de Bruijn <will...@google.com>
---
arch/alpha/include/uapi/asm/socket.h | 2 ++
arch/frv/include/uapi/asm/socket.h | 2 ++
arch/ia64/include/uapi/asm/socket.h | 2 ++
arch/m32r/include/uapi/asm/socket.h | 2 ++
arch/mips/include/uapi/asm/socket.h | 2 ++
arch/mn10300/include/uapi/asm/socket.h | 2 ++
arch/parisc/include/uapi/asm/socket.h | 2 ++
arch/s390/include/uapi/asm/socket.h | 2 ++
arch/sparc/include/uapi/asm/socket.h | 2 ++
arch/xtensa/include/uapi/asm/socket.h | 2 ++
include/uapi/asm-generic/socket.h | 2 ++
net/core/skbuff.c | 3 +++
net/core/sock.c | 14 ++++++++++++++
13 files changed, 39 insertions(+)
diff --git a/arch/alpha/include/uapi/asm/socket.h
b/arch/alpha/include/uapi/asm/socket.h
index 0926de63a62b..baa974af3bf5 100644
--- a/arch/alpha/include/uapi/asm/socket.h
+++ b/arch/alpha/include/uapi/asm/socket.h
@@ -107,4 +107,6 @@
#define SCM_TIMESTAMPING_PKTINFO 58
+#define SO_ZEROCOPY 59
+
#endif /* _UAPI_ASM_SOCKET_H */
diff --git a/arch/frv/include/uapi/asm/socket.h
b/arch/frv/include/uapi/asm/socket.h
index e491ff08b9a9..2946772c7cc9 100644
--- a/arch/frv/include/uapi/asm/socket.h
+++ b/arch/frv/include/uapi/asm/socket.h
@@ -100,5 +100,7 @@
#define SCM_TIMESTAMPING_PKTINFO 58
+#define SO_ZEROCOPY 59
+
#endif /* _ASM_SOCKET_H */
diff --git a/arch/ia64/include/uapi/asm/socket.h
b/arch/ia64/include/uapi/asm/socket.h
index 869372413333..f1bdc5220254 100644
--- a/arch/ia64/include/uapi/asm/socket.h
+++ b/arch/ia64/include/uapi/asm/socket.h
@@ -109,4 +109,6 @@
#define SCM_TIMESTAMPING_PKTINFO 58
+#define SO_ZEROCOPY 59
+
#endif /* _ASM_IA64_SOCKET_H */
diff --git a/arch/m32r/include/uapi/asm/socket.h
b/arch/m32r/include/uapi/asm/socket.h
index 5d97890a8704..f9573e69d5dd 100644
--- a/arch/m32r/include/uapi/asm/socket.h
+++ b/arch/m32r/include/uapi/asm/socket.h
@@ -100,4 +100,6 @@
#define SCM_TIMESTAMPING_PKTINFO 58
+#define SO_ZEROCOPY 59
+
#endif /* _ASM_M32R_SOCKET_H */
diff --git a/arch/mips/include/uapi/asm/socket.h
b/arch/mips/include/uapi/asm/socket.h
index 365ff51f033a..d8c67fbd0f3d 100644
--- a/arch/mips/include/uapi/asm/socket.h
+++ b/arch/mips/include/uapi/asm/socket.h
@@ -118,4 +118,6 @@
#define SCM_TIMESTAMPING_PKTINFO 58
+#define SO_ZEROCOPY 59
+
#endif /* _UAPI_ASM_SOCKET_H */
diff --git a/arch/mn10300/include/uapi/asm/socket.h
b/arch/mn10300/include/uapi/asm/socket.h
index d013c0da0256..8fc7eb3e1a7a 100644
--- a/arch/mn10300/include/uapi/asm/socket.h
+++ b/arch/mn10300/include/uapi/asm/socket.h
@@ -100,4 +100,6 @@
#define SCM_TIMESTAMPING_PKTINFO 58
+#define SO_ZEROCOPY 59
+
#endif /* _ASM_SOCKET_H */
diff --git a/arch/parisc/include/uapi/asm/socket.h
b/arch/parisc/include/uapi/asm/socket.h
index b893ca14fade..8dcdaaa80c51 100644
--- a/arch/parisc/include/uapi/asm/socket.h
+++ b/arch/parisc/include/uapi/asm/socket.h
@@ -99,4 +99,6 @@
#define SCM_TIMESTAMPING_PKTINFO 0x4033
+#define SO_ZEROCOPY 0x4034
+
#endif /* _UAPI_ASM_SOCKET_H */
diff --git a/arch/s390/include/uapi/asm/socket.h
b/arch/s390/include/uapi/asm/socket.h
index fb9769d7e74e..32b1a8496cc3 100644
--- a/arch/s390/include/uapi/asm/socket.h
+++ b/arch/s390/include/uapi/asm/socket.h
@@ -106,4 +106,6 @@
#define SCM_TIMESTAMPING_PKTINFO 58
+#define SO_ZEROCOPY 59
+
#endif /* _ASM_SOCKET_H */
diff --git a/arch/sparc/include/uapi/asm/socket.h
b/arch/sparc/include/uapi/asm/socket.h
index 5d673302fd41..7625632a3120 100644
--- a/arch/sparc/include/uapi/asm/socket.h
+++ b/arch/sparc/include/uapi/asm/socket.h
@@ -96,6 +96,8 @@
#define SCM_TIMESTAMPING_PKTINFO 0x003c
+#define SO_ZEROCOPY 0x003d
+
/* Security levels - as per NRL IPv6 - don't actually do anything */
#define SO_SECURITY_AUTHENTICATION 0x5001
#define SO_SECURITY_ENCRYPTION_TRANSPORT 0x5002
diff --git a/arch/xtensa/include/uapi/asm/socket.h
b/arch/xtensa/include/uapi/asm/socket.h
index 982c2533f912..6c44060a3924 100644
--- a/arch/xtensa/include/uapi/asm/socket.h
+++ b/arch/xtensa/include/uapi/asm/socket.h
@@ -111,4 +111,6 @@
#define SCM_TIMESTAMPING_PKTINFO 58
+#define SO_ZEROCOPY 59
+
#endif /* _XTENSA_SOCKET_H */
diff --git a/include/uapi/asm-generic/socket.h
b/include/uapi/asm-generic/socket.h
index a5f6e819fafd..2c5adee35bac 100644
--- a/include/uapi/asm-generic/socket.h
+++ b/include/uapi/asm-generic/socket.h
@@ -102,4 +102,6 @@
#define SCM_TIMESTAMPING_PKTINFO 58
+#define SO_ZEROCOPY 59
+
#endif /* __ASM_GENERIC_SOCKET_H */
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 31e31185c557..34fa1f2b7ff2 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -948,6 +948,9 @@ struct ubuf_info *sock_zerocopy_alloc(struct sock *sk,
size_t size)
WARN_ON_ONCE(!in_task());
+ if (!sock_flag(sk, SOCK_ZEROCOPY))
+ return NULL;
+
skb = sock_omalloc(sk, 0, GFP_KERNEL);
if (!skb)
return NULL;
diff --git a/net/core/sock.c b/net/core/sock.c
index d1309d6f9f3d..72f5f256c2bc 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -1055,6 +1055,16 @@ int sock_setsockopt(struct socket *sock, int level, int
optname,
if (val == 1)
dst_negative_advice(sk);
break;
+
+ case SO_ZEROCOPY:
+ if (sk->sk_state != TCP_CLOSE)
+ ret = -EBUSY;
+ else if (val < 0 || val > 1)
+ ret = -EINVAL;
+ else
+ sock_valbool_flag(sk, SOCK_ZEROCOPY, valbool);
+ break;
+
default:
ret = -ENOPROTOOPT;
break;
@@ -1350,6 +1360,10 @@ int sock_getsockopt(struct socket *sock, int level, int
optname,
v.val64 = sock_gen_cookie(sk);
break;
+ case SO_ZEROCOPY:
+ v.val = sock_flag(sk, SOCK_ZEROCOPY);
+ break;
+
default:
/* We implement the SO_SNDLOWAT etc to not be settable
* (1003.1g 7).
--
2.13.1.611.g7e3b11ae1-goog
