net: add option to enable error queue packets waking select

Currently, when a socket receives something on the error queue it only wakes up
the socket on select if it is in the "read" list, that is the socket has
something to read. It is useful also to wake the socket if it is in the error
list, which would enable software to wait on error queue packets without waking
up for regular data on the socket. The main use case is for receiving
timestamped transmit packets which return the timestamp to the socket via the
error queue. This enables an application to select on the socket for the error
queue only instead of for the regular traffic.

-v2-
* Added the SO_SELECT_ERR_QUEUE socket option to every architechture specific file
* Modified every socket poll function that checks error queue

Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Cc: Jeffrey Kirsher <jeffrey.t.kirsher@intel.com>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Matthew Vick <matthew.vick@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

23 files changed, 53 insertions, 6 deletions

diff --git a/arch/alpha/include/uapi/asm/socket.h b/arch/alpha/include/uapi/asm/socket.h
index c5195524d1e..eee6ea76bda 100644
--- a/arch/alpha/include/uapi/asm/socket.h
+++ b/arch/alpha/include/uapi/asm/socket.h
@@ -79,4 +79,6 @@
 
 #define SO_LOCK_FILTER		44
 
+#define SO_SELECT_ERR_QUEUE	45
+
 #endif /* _UAPI_ASM_SOCKET_H */
diff --git a/arch/avr32/include/uapi/asm/socket.h b/arch/avr32/include/uapi/asm/socket.h
index 51c6401582e..37401f53512 100644
--- a/arch/avr32/include/uapi/asm/socket.h
+++ b/arch/avr32/include/uapi/asm/socket.h
@@ -72,4 +72,6 @@
 
 #define SO_LOCK_FILTER		44
 
+#define SO_SELECT_ERR_QUEUE	45
+
 #endif /* __ASM_AVR32_SOCKET_H */
diff --git a/arch/cris/include/uapi/asm/socket.h b/arch/cris/include/uapi/asm/socket.h
index 50692b738c7..ba409c9947b 100644
--- a/arch/cris/include/uapi/asm/socket.h
+++ b/arch/cris/include/uapi/asm/socket.h
@@ -74,6 +74,8 @@
 
 #define SO_LOCK_FILTER		44
 
+#define SO_SELECT_ERR_QUEUE	45
+
 #endif /* _ASM_SOCKET_H */
 
 
diff --git a/arch/frv/include/uapi/asm/socket.h b/arch/frv/include/uapi/asm/socket.h
index 595391f0f98..31dbb5d8e13 100644
--- a/arch/frv/include/uapi/asm/socket.h
+++ b/arch/frv/include/uapi/asm/socket.h
@@ -72,5 +72,7 @@
 
 #define SO_LOCK_FILTER		44
 
+#define SO_SELECT_ERR_QUEUE	45
+
 #endif /* _ASM_SOCKET_H */
 
diff --git a/arch/h8300/include/uapi/asm/socket.h b/arch/h8300/include/uapi/asm/socket.h
index 43e32621da7..5d1c6d0870e 100644
--- a/arch/h8300/include/uapi/asm/socket.h
+++ b/arch/h8300/include/uapi/asm/socket.h
@@ -72,4 +72,6 @@
 
 #define SO_LOCK_FILTER		44
 
+#define SO_SELECT_ERR_QUEUE	45
+
 #endif /* _ASM_SOCKET_H */
diff --git a/arch/ia64/include/uapi/asm/socket.h b/arch/ia64/include/uapi/asm/socket.h
index c567adc8bea..6b4329f18b2 100644
--- a/arch/ia64/include/uapi/asm/socket.h
+++ b/arch/ia64/include/uapi/asm/socket.h
@@ -81,4 +81,6 @@
 
 #define SO_LOCK_FILTER		44
 
+#define SO_SELECT_ERR_QUEUE	45
+
 #endif /* _ASM_IA64_SOCKET_H */
diff --git a/arch/m32r/include/uapi/asm/socket.h b/arch/m32r/include/uapi/asm/socket.h
index 519afa2755d..2a3b59e0e17 100644
--- a/arch/m32r/include/uapi/asm/socket.h
+++ b/arch/m32r/include/uapi/asm/socket.h
@@ -72,4 +72,6 @@
 
 #define SO_LOCK_FILTER		44
 
+#define SO_SELECT_ERR_QUEUE	45
+
 #endif /* _ASM_M32R_SOCKET_H */
diff --git a/arch/mips/include/uapi/asm/socket.h b/arch/mips/include/uapi/asm/socket.h
index 47132f44c95..3b211507be7 100644
--- a/arch/mips/include/uapi/asm/socket.h
+++ b/arch/mips/include/uapi/asm/socket.h
@@ -90,4 +90,6 @@
 
 #define SO_LOCK_FILTER		44
 
+#define SO_SELECT_ERR_QUEUE	45
+
 #endif /* _UAPI_ASM_SOCKET_H */
diff --git a/arch/mn10300/include/uapi/asm/socket.h b/arch/mn10300/include/uapi/asm/socket.h
index 5c7c7c98854..b4ce844c939 100644
--- a/arch/mn10300/include/uapi/asm/socket.h
+++ b/arch/mn10300/include/uapi/asm/socket.h
@@ -72,4 +72,6 @@
 
 #define SO_LOCK_FILTER		44
 
+#define SO_SELECT_ERR_QUEUE	45
+
 #endif /* _ASM_SOCKET_H */
diff --git a/arch/parisc/include/uapi/asm/socket.h b/arch/parisc/include/uapi/asm/socket.h
index 526e4b9aece..70c512a386f 100644
--- a/arch/parisc/include/uapi/asm/socket.h
+++ b/arch/parisc/include/uapi/asm/socket.h
@@ -71,6 +71,8 @@
 
 #define SO_LOCK_FILTER		0x4025
 
+#define SO_SELECT_ERR_QUEUE	0x4026
+
 /* O_NONBLOCK clashes with the bits used for socket types.  Therefore we
  * have to define SOCK_NONBLOCK to a different value here.
  */
diff --git a/arch/powerpc/include/uapi/asm/socket.h b/arch/powerpc/include/uapi/asm/socket.h
index a26dcaece50..a36daf3c6f9 100644
--- a/arch/powerpc/include/uapi/asm/socket.h
+++ b/arch/powerpc/include/uapi/asm/socket.h
@@ -79,4 +79,6 @@
 
 #define SO_LOCK_FILTER		44
 
+#define SO_SELECT_ERR_QUEUE	45
+
 #endif	/* _ASM_POWERPC_SOCKET_H */
diff --git a/arch/s390/include/uapi/asm/socket.h b/arch/s390/include/uapi/asm/socket.h
index f99eea7fff0..2dacb306835 100644
--- a/arch/s390/include/uapi/asm/socket.h
+++ b/arch/s390/include/uapi/asm/socket.h
@@ -78,4 +78,6 @@
 
 #define SO_LOCK_FILTER		44
 
+#define SO_SELECT_ERR_QUEUE	45
+
 #endif /* _ASM_SOCKET_H */
diff --git a/arch/sparc/include/uapi/asm/socket.h b/arch/sparc/include/uapi/asm/socket.h
index cbbad74b2e0..89f49b68a21 100644
--- a/arch/sparc/include/uapi/asm/socket.h
+++ b/arch/sparc/include/uapi/asm/socket.h
@@ -68,6 +68,8 @@
 
 #define SO_LOCK_FILTER		0x0028
 
+#define SO_SELECT_ERR_QUEUE	0x0029
+
 /* 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 35905cb6e41..a8f44f50e65 100644
--- a/arch/xtensa/include/uapi/asm/socket.h
+++ b/arch/xtensa/include/uapi/asm/socket.h
@@ -83,4 +83,6 @@
 
 #define SO_LOCK_FILTER		44
 
+#define SO_SELECT_ERR_QUEUE	45
+
 #endif	/* _XTENSA_SOCKET_H */
diff --git a/include/net/sock.h b/include/net/sock.h
index 14f6e9d19dc..08f05f96473 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -667,6 +667,7 @@ enum sock_flags {
 		     * user-space instead.
 		     */
 	SOCK_FILTER_LOCKED, /* Filter cannot be changed anymore */
+	SOCK_SELECT_ERR_QUEUE, /* Wake select on error queue */
 };
 
 static inline void sock_copy_flags(struct sock *nsk, struct sock *osk)
diff --git a/include/uapi/asm-generic/socket.h b/include/uapi/asm-generic/socket.h
index 4ef3acbba5d..c5d2e3a1cf6 100644
--- a/include/uapi/asm-generic/socket.h
+++ b/include/uapi/asm-generic/socket.h
@@ -74,4 +74,6 @@
 
 #define SO_LOCK_FILTER		44
 
+#define SO_SELECT_ERR_QUEUE	45
+
 #endif /* __ASM_GENERIC_SOCKET_H */
diff --git a/net/bluetooth/af_bluetooth.c b/net/bluetooth/af_bluetooth.c
index d3ee69b35a7..409902f892f 100644
--- a/net/bluetooth/af_bluetooth.c
+++ b/net/bluetooth/af_bluetooth.c
@@ -422,7 +422,8 @@ unsigned int bt_sock_poll(struct file *file, struct socket *sock,
 		return bt_accept_poll(sk);
 
 	if (sk->sk_err || !skb_queue_empty(&sk->sk_error_queue))
-		mask |= POLLERR;
+		mask |= POLLERR |
+			sock_flag(sk, SOCK_SELECT_ERR_QUEUE) ? POLLPRI : 0;
 
 	if (sk->sk_shutdown & RCV_SHUTDOWN)
 		mask |= POLLRDHUP | POLLIN | POLLRDNORM;
diff --git a/net/core/datagram.c b/net/core/datagram.c
index 368f9c3f9dc..36da5b66351 100644
--- a/net/core/datagram.c
+++ b/net/core/datagram.c
@@ -749,7 +749,9 @@ unsigned int datagram_poll(struct file *file, struct socket *sock,
 
 	/* exceptional events? */
 	if (sk->sk_err || !skb_queue_empty(&sk->sk_error_queue))
-		mask |= POLLERR;
+		mask |= POLLERR |
+			sock_flag(sk, SOCK_SELECT_ERR_QUEUE) ? POLLPRI : 0;
+
 	if (sk->sk_shutdown & RCV_SHUTDOWN)
 		mask |= POLLRDHUP | POLLIN | POLLRDNORM;
 	if (sk->sk_shutdown == SHUTDOWN_MASK)
diff --git a/net/core/sock.c b/net/core/sock.c
index a19e728d5fb..2ff5f3619a8 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -907,6 +907,10 @@ set_rcvbuf:
 		sock_valbool_flag(sk, SOCK_NOFCS, valbool);
 		break;
 
+	case SO_SELECT_ERR_QUEUE:
+		sock_valbool_flag(sk, SOCK_SELECT_ERR_QUEUE, valbool);
+		break;
+
 	default:
 		ret = -ENOPROTOOPT;
 		break;
@@ -1160,6 +1164,10 @@ int sock_getsockopt(struct socket *sock, int level, int optname,
 		v.val = sock_flag(sk, SOCK_FILTER_LOCKED);
 		break;
 
+	case SO_SELECT_ERR_QUEUE:
+		v.val = sock_flag(sk, SOCK_SELECT_ERR_QUEUE);
+		break;
+
 	default:
 		return -ENOPROTOOPT;
 	}
diff --git a/net/iucv/af_iucv.c b/net/iucv/af_iucv.c
index a7d11ffe428..f0550a38f29 100644
--- a/net/iucv/af_iucv.c
+++ b/net/iucv/af_iucv.c
@@ -1461,7 +1461,8 @@ unsigned int iucv_sock_poll(struct file *file, struct socket *sock,
 		return iucv_accept_poll(sk);
 
 	if (sk->sk_err || !skb_queue_empty(&sk->sk_error_queue))
-		mask |= POLLERR;
+		mask |= POLLERR |
+			sock_flag(sk, SOCK_SELECT_ERR_QUEUE) ? POLLPRI : 0;
 
 	if (sk->sk_shutdown & RCV_SHUTDOWN)
 		mask |= POLLRDHUP;
diff --git a/net/nfc/llcp/sock.c b/net/nfc/llcp/sock.c
index f1b377e247f..2d55e8a4595 100644
--- a/net/nfc/llcp/sock.c
+++ b/net/nfc/llcp/sock.c
@@ -521,7 +521,8 @@ static unsigned int llcp_sock_poll(struct file *file, struct socket *sock,
 		return llcp_accept_poll(sk);
 
 	if (sk->sk_err || !skb_queue_empty(&sk->sk_error_queue))
-		mask |= POLLERR;
+		mask |= POLLERR |
+			sock_flag(sk, SOCK_SELECT_ERR_QUEUE) ? POLLPRI : 0;
 
 	if (!skb_queue_empty(&sk->sk_receive_queue))
 		mask |= POLLIN | POLLRDNORM;
diff --git a/net/sctp/socket.c b/net/sctp/socket.c
index b9070736b8d..dd21ae3013d 100644
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -6185,7 +6185,8 @@ unsigned int sctp_poll(struct file *file, struct socket *sock, poll_table *wait)
 
 	/* Is there any exceptional events?  */
 	if (sk->sk_err || !skb_queue_empty(&sk->sk_error_queue))
-		mask |= POLLERR;
+		mask |= POLLERR |
+			sock_flag(sk, SOCK_SELECT_ERR_QUEUE) ? POLLPRI : 0;
 	if (sk->sk_shutdown & RCV_SHUTDOWN)
 		mask |= POLLRDHUP | POLLIN | POLLRDNORM;
 	if (sk->sk_shutdown == SHUTDOWN_MASK)
diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
index 971282b6f6a..fb7a63ff71a 100644
--- a/net/unix/af_unix.c
+++ b/net/unix/af_unix.c
@@ -2196,7 +2196,9 @@ static unsigned int unix_dgram_poll(struct file *file, struct socket *sock,
 
 	/* exceptional events? */
 	if (sk->sk_err || !skb_queue_empty(&sk->sk_error_queue))
-		mask |= POLLERR;
+		mask |= POLLERR |
+			sock_flag(sk, SOCK_SELECT_ERR_QUEUE) ? POLLPRI : 0;
+
 	if (sk->sk_shutdown & RCV_SHUTDOWN)
 		mask |= POLLRDHUP | POLLIN | POLLRDNORM;
 	if (sk->sk_shutdown == SHUTDOWN_MASK)