net: Add sendmmsg socket system call

This patch adds a multiple message send syscall and is the send
version of the existing recvmmsg syscall. This is heavily
based on the patch by Arnaldo that added recvmmsg.

I wrote a microbenchmark to test the performance gains of using
this new syscall:

http://ozlabs.org/~anton/junkcode/sendmmsg_test.c

The test was run on a ppc64 box with a 10 Gbit network card. The
benchmark can send both UDP and RAW ethernet packets.

64B UDP

batch   pkts/sec
1       804570
2       872800 (+ 8 %)
4       916556 (+14 %)
8       939712 (+17 %)
16      952688 (+18 %)
32      956448 (+19 %)
64      964800 (+20 %)

64B raw socket

batch   pkts/sec
1       1201449
2       1350028 (+12 %)
4       1461416 (+22 %)
8       1513080 (+26 %)
16      1541216 (+28 %)
32      1553440 (+29 %)
64      1557888 (+30 %)

We see a 20% improvement in throughput on UDP send and 30%
on raw socket send.

[ Add sparc syscall entries. -DaveM ]

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Author: antonblanchard

arch/powerpc/include/asm/systbl.h

@@ -352,3 +352,4 @@ SYSCALL_SPU(name_to_handle_at)
 COMPAT_SYS_SPU(open_by_handle_at)
 COMPAT_SYS_SPU(clock_adjtime)
 SYSCALL_SPU(syncfs)
+COMPAT_SYS_SPU(sendmmsg)

arch/powerpc/include/asm/unistd.h

@@ -371,10 +371,11 @@
 #define __NR_open_by_handle_at	346
 #define __NR_clock_adjtime	347
 #define __NR_syncfs		348
+#define __NR_sendmmsg		349
 
 #ifdef __KERNEL__
 
-#define __NR_syscalls		349
+#define __NR_syscalls		350
 
 #define __NR__exit __NR_exit
 #define NR_syscalls	__NR_syscalls

arch/sparc/include/asm/unistd.h

@@ -404,8 +404,9 @@
 #define __NR_open_by_handle_at	333
 #define __NR_clock_adjtime	334
 #define __NR_syncfs		335
+#define __NR_sendmmsg		336
 
-#define NR_syscalls		336
+#define NR_syscalls		337
 
 #ifdef __32bit_syscall_numbers__
 /* Sparc 32-bit only has the "setresuid32", "getresuid32" variants,

arch/sparc/kernel/systbls_32.S

@@ -84,4 +84,4 @@ sys_call_table:
 /*320*/	.long sys_dup3, sys_pipe2, sys_inotify_init1, sys_accept4, sys_preadv
 /*325*/	.long sys_pwritev, sys_rt_tgsigqueueinfo, sys_perf_event_open, sys_recvmmsg, sys_fanotify_init
 /*330*/	.long sys_fanotify_mark, sys_prlimit64, sys_name_to_handle_at, sys_open_by_handle_at, sys_clock_adjtime
-/*335*/	.long sys_syncfs
+/*335*/	.long sys_syncfs, sys_sendmmsg

arch/sparc/kernel/systbls_64.S

@@ -85,7 +85,7 @@ sys_call_table32:
 /*320*/	.word sys_dup3, sys_pipe2, sys_inotify_init1, sys_accept4, compat_sys_preadv
 	.word compat_sys_pwritev, compat_sys_rt_tgsigqueueinfo, sys_perf_event_open, compat_sys_recvmmsg, sys_fanotify_init
 /*330*/	.word sys32_fanotify_mark, sys_prlimit64, sys_name_to_handle_at, compat_sys_open_by_handle_at, compat_sys_clock_adjtime
-	.word sys_syncfs
+	.word sys_syncfs, compat_sys_sendmmsg
 
 #endif /* CONFIG_COMPAT */
 
@@ -162,4 +162,4 @@ sys_call_table:
 /*320*/	.word sys_dup3, sys_pipe2, sys_inotify_init1, sys_accept4, sys_preadv
 	.word sys_pwritev, sys_rt_tgsigqueueinfo, sys_perf_event_open, sys_recvmmsg, sys_fanotify_init
 /*330*/	.word sys_fanotify_mark, sys_prlimit64, sys_name_to_handle_at, sys_open_by_handle_at, sys_clock_adjtime
-	.word sys_syncfs
+	.word sys_syncfs, sys_sendmmsg

arch/x86/ia32/ia32entry.S

@@ -848,4 +848,5 @@ ia32_sys_call_table:
 	.quad compat_sys_open_by_handle_at
 	.quad compat_sys_clock_adjtime
 	.quad sys_syncfs
+	.quad compat_sys_sendmmsg	/* 345 */
 ia32_syscall_end:

arch/x86/include/asm/unistd_32.h

@@ -350,10 +350,11 @@
 #define __NR_open_by_handle_at  342
 #define __NR_clock_adjtime	343
 #define __NR_syncfs             344
+#define __NR_sendmmsg		345
 
 #ifdef __KERNEL__
 
-#define NR_syscalls 345
+#define NR_syscalls 346
 
 #define __ARCH_WANT_IPC_PARSE_VERSION
 #define __ARCH_WANT_OLD_READDIR

arch/x86/include/asm/unistd_64.h

@@ -677,6 +677,8 @@ __SYSCALL(__NR_open_by_handle_at, sys_open_by_handle_at)
 __SYSCALL(__NR_clock_adjtime, sys_clock_adjtime)
 #define __NR_syncfs                             306
 __SYSCALL(__NR_syncfs, sys_syncfs)
+#define __NR_sendmmsg				307
+__SYSCALL(__NR_sendmmsg, sys_sendmmsg)
 
 #ifndef __NO_STUBS
 #define __ARCH_WANT_OLD_READDIR

arch/x86/kernel/syscall_table_32.S

@@ -344,3 +344,4 @@ ENTRY(sys_call_table)
 	.long sys_open_by_handle_at
 	.long sys_clock_adjtime
 	.long sys_syncfs
+	.long sys_sendmmsg		/* 345 */

include/linux/net.h

@@ -42,6 +42,7 @@
 #define SYS_RECVMSG	17		/* sys_recvmsg(2)		*/
 #define SYS_ACCEPT4	18		/* sys_accept4(2)		*/
 #define SYS_RECVMMSG	19		/* sys_recvmmsg(2)		*/
+#define SYS_SENDMMSG	20		/* sys_sendmmsg(2)		*/
 
 typedef enum {
 	SS_FREE = 0,			/* not allocated		*/

include/linux/socket.h

@@ -333,5 +333,7 @@ struct timespec;
 
 extern int __sys_recvmmsg(int fd, struct mmsghdr __user *mmsg, unsigned int vlen,
 			  unsigned int flags, struct timespec *timeout);
+extern int __sys_sendmmsg(int fd, struct mmsghdr __user *mmsg,
+			  unsigned int vlen, unsigned int flags);
 #endif /* not kernel and not glibc */
 #endif /* _LINUX_SOCKET_H */

include/linux/syscalls.h

@@ -610,6 +610,8 @@ asmlinkage long sys_send(int, void __user *, size_t, unsigned);
 asmlinkage long sys_sendto(int, void __user *, size_t, unsigned,
 				struct sockaddr __user *, int);
 asmlinkage long sys_sendmsg(int fd, struct msghdr __user *msg, unsigned flags);
+asmlinkage long sys_sendmmsg(int fd, struct mmsghdr __user *msg,
+			     unsigned int vlen, unsigned flags);
 asmlinkage long sys_recv(int, void __user *, size_t, unsigned);
 asmlinkage long sys_recvfrom(int, void __user *, size_t, unsigned,
 				struct sockaddr __user *, int __user *);

include/net/compat.h

@@ -43,6 +43,8 @@ extern int compat_sock_get_timestampns(struct sock *, struct timespec __user *);
 extern int get_compat_msghdr(struct msghdr *, struct compat_msghdr __user *);
 extern int verify_compat_iovec(struct msghdr *, struct iovec *, struct sockaddr *, int);
 extern asmlinkage long compat_sys_sendmsg(int,struct compat_msghdr __user *,unsigned);
+extern asmlinkage long compat_sys_sendmmsg(int, struct compat_mmsghdr __user *,
+					   unsigned, unsigned);
 extern asmlinkage long compat_sys_recvmsg(int,struct compat_msghdr __user *,unsigned);
 extern asmlinkage long compat_sys_recvmmsg(int, struct compat_mmsghdr __user *,
 					   unsigned, unsigned,

kernel/sys_ni.c

@@ -46,7 +46,9 @@ cond_syscall(sys_getsockopt);
 cond_syscall(compat_sys_getsockopt);
 cond_syscall(sys_shutdown);
 cond_syscall(sys_sendmsg);
+cond_syscall(sys_sendmmsg);
 cond_syscall(compat_sys_sendmsg);
+cond_syscall(compat_sys_sendmmsg);
 cond_syscall(sys_recvmsg);
 cond_syscall(sys_recvmmsg);
 cond_syscall(compat_sys_recvmsg);

net/compat.c

@@ -722,11 +722,11 @@ EXPORT_SYMBOL(compat_mc_getsockopt);
 
 /* Argument list sizes for compat_sys_socketcall */
 #define AL(x) ((x) * sizeof(u32))
-static unsigned char nas[20] = {
+static unsigned char nas[21] = {
 	AL(0), AL(3), AL(3), AL(3), AL(2), AL(3),
 	AL(3), AL(3), AL(4), AL(4), AL(4), AL(6),
 	AL(6), AL(2), AL(5), AL(5), AL(3), AL(3),
-	AL(4), AL(5)
+	AL(4), AL(5), AL(4)
 };
 #undef AL
 
@@ -735,6 +735,13 @@ asmlinkage long compat_sys_sendmsg(int fd, struct compat_msghdr __user *msg, uns
 	return sys_sendmsg(fd, (struct msghdr __user *)msg, flags | MSG_CMSG_COMPAT);
 }
 
+asmlinkage long compat_sys_sendmmsg(int fd, struct compat_mmsghdr __user *mmsg,
+				    unsigned vlen, unsigned int flags)
+{
+	return __sys_sendmmsg(fd, (struct mmsghdr __user *)mmsg, vlen,
+			      flags | MSG_CMSG_COMPAT);
+}
+
 asmlinkage long compat_sys_recvmsg(int fd, struct compat_msghdr __user *msg, unsigned int flags)
 {
 	return sys_recvmsg(fd, (struct msghdr __user *)msg, flags | MSG_CMSG_COMPAT);
@@ -780,7 +787,7 @@ asmlinkage long compat_sys_socketcall(int call, u32 __user *args)
 	u32 a[6];
 	u32 a0, a1;
 
-	if (call < SYS_SOCKET || call > SYS_RECVMMSG)
+	if (call < SYS_SOCKET || call > SYS_SENDMMSG)
 		return -EINVAL;
 	if (copy_from_user(a, args, nas[call]))
 		return -EFAULT;
@@ -839,6 +846,9 @@ asmlinkage long compat_sys_socketcall(int call, u32 __user *args)
 	case SYS_SENDMSG:
 		ret = compat_sys_sendmsg(a0, compat_ptr(a1), a[2]);
 		break;
+	case SYS_SENDMMSG:
+		ret = compat_sys_sendmmsg(a0, compat_ptr(a1), a[2], a[3]);
+		break;
 	case SYS_RECVMSG:
 		ret = compat_sys_recvmsg(a0, compat_ptr(a1), a[2]);
 		break;