[PATCH] Implement recvmmsg also as socketcall

[PATCH] Implement recvmmsg also as socketcall

[Andreas Schwab]

2010-05-21  Andreas Schwab  <schwab@redhat.com>

	* sysdeps/unix/sysv/linux/Makefile (sysdep_routines): Add recvmmsg
	and internal_recvmmsg.
	* sysdeps/unix/sysv/linux/recvmmsg.c: New file.
	* sysdeps/unix/sysv/linux/internal_recvmmsg.S: New file.
	* sysdeps/unix/sysv/linux/socketcall.h (SOCKOP_recvmmsg): Define.
	* sysdeps/unix/sysv/linux/syscalls.list (recvmmsg): Remove.
---
 sysdeps/unix/sysv/linux/Makefile            |    2 +-
 sysdeps/unix/sysv/linux/internal_recvmmsg.S |   14 ++++
 sysdeps/unix/sysv/linux/kernel-features.h   |    5 ++
 sysdeps/unix/sysv/linux/recvmmsg.c          |  100 +++++++++++++++++++++++++++
 sysdeps/unix/sysv/linux/socketcall.h        |    1 +
 sysdeps/unix/sysv/linux/syscalls.list       |    1 -
 6 files changed, 121 insertions(+), 2 deletions(-)
 create mode 100644 sysdeps/unix/sysv/linux/internal_recvmmsg.S
 create mode 100644 sysdeps/unix/sysv/linux/recvmmsg.c

diff --git a/sysdeps/unix/sysv/linux/Makefile b/sysdeps/unix/sysv/linux/Makefile
index 91c123b..9c53b2d 100644
--- a/sysdeps/unix/sysv/linux/Makefile
+++ b/sysdeps/unix/sysv/linux/Makefile
@@ -12,7 +12,7 @@ CFLAGS-malloc.c += -DMORECORE_CLEARS=2
 endif
 
 ifeq ($(subdir),socket)
-sysdep_routines += internal_accept4
+sysdep_routines += internal_accept4 recvmmsg internal_recvmmsg
 endif
 
 ifeq ($(subdir),misc)
diff --git a/sysdeps/unix/sysv/linux/internal_recvmmsg.S b/sysdeps/unix/sysv/linux/internal_recvmmsg.S
new file mode 100644
index 0000000..66c1357
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/internal_recvmmsg.S
@@ -0,0 +1,14 @@
+#include <kernel-features.h>
+#include <sys/syscall.h>
+#if !defined __NR_recvmmsg && defined __NR_socketcall
+# define socket	recvmmsg
+# ifdef __ASSUME_RECVMMSG
+#  define __socket recvmmsg
+# else
+#  define __socket __internal_recvmmsg
+# endif
+# define NARGS 5
+# define NEED_CANCELLATION
+# define NO_WEAK_ALIAS
+# include <socket.S>
+#endif
diff --git a/sysdeps/unix/sysv/linux/kernel-features.h b/sysdeps/unix/sysv/linux/kernel-features.h
index 43783c1..b3f2456 100644
--- a/sysdeps/unix/sysv/linux/kernel-features.h
+++ b/sysdeps/unix/sysv/linux/kernel-features.h
@@ -525,3 +525,8 @@
 #if __LINUX_KERNEL_VERSION >= 0x020620
 # define __ASSUME_F_GETOWN_EX	1
 #endif
+
+/* Support for the recvmmsg syscall was added in 2.6.33.  */
+#if __LINUX_KERNEL_VERSION >= 0x020621
+# define __ASSUME_RECVMMSG	1
+#endif
diff --git a/sysdeps/unix/sysv/linux/recvmmsg.c b/sysdeps/unix/sysv/linux/recvmmsg.c
new file mode 100644
index 0000000..0c08171
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/recvmmsg.c
@@ -0,0 +1,100 @@
+/* Copyright (C) 2010 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Andreas Schwab <schwab@redhat.com>, 2010.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
+#include <errno.h>
+#include <sys/socket.h>
+
+#include <sysdep-cancel.h>
+#include <sys/syscall.h>
+#include <kernel-features.h>
+
+
+#ifdef __NR_recvmmsg
+int
+recvmmsg (int fd, struct mmsghdr *vmessages, unsigned int vlen, int flags,
+	  const struct timespec *tmo)
+{
+  if (SINGLE_THREAD_P)
+    return INLINE_SYSCALL (recvmmsg, 5, fd, vmessages, vlen, flags, tmo);
+
+  int oldtype = LIBC_CANCEL_ASYNC ();
+
+  int result = INLINE_SYSCALL (recvmmsg, 5, fd, vmessages, vlen, flags, tmo);
+
+  LIBC_CANCEL_RESET (oldtype);
+
+  return result;
+}
+#elif defined __NR_socketcall
+# ifndef __ASSUME_RECVMMSG
+extern int __internal_recvmmsg (int fd, struct mmsghdr *vmessages,
+				unsigned int vlen, int flags,
+				const struct timespec *tmo)
+     attribute_hidden;
+
+static int have_recvmmsg;
+
+int
+recvmmsg (int fd, struct mmsghdr *vmessages, unsigned int vlen, int flags,
+	  const struct timespec *tmo)
+{
+  if (__builtin_expect (have_recvmmsg >= 0, 1))
+    {
+      int ret = __internal_recvmmsg (fd, vmessages, vlen, flags, tmo);
+      /* The kernel returns -EINVAL for unknown socket operations.
+	 We need to convert that error to an ENOSYS error.  */
+      if (__builtin_expect (ret < 0, 0)
+	  && have_recvmmsg == 0
+	  && errno == EINVAL)
+	{
+	  /* Try another call, this time with an invalid file
+	     descriptor and all other parameters cleared.  This call
+	     will not cause any harm and it will return
+	     immediately.  */
+	  ret = __internal_recvmmsg (-1, 0, 0, 0, 0);
+	  if (errno == EINVAL)
+	    {
+	      have_recvmmsg = -1;
+	      __set_errno (ENOSYS);
+	    }
+	  else
+	    {
+	      have_recvmmsg = 1;
+	      __set_errno (EINVAL);
+	    }
+	  return -1;
+	}
+      return ret;
+    }
+  __set_errno (ENOSYS);
+  return -1;
+}
+# else
+/* When __ASSUME_RECVMMSG recvmmsg is defined in internal_recvmmsg.S.  */
+# endif
+#else
+int
+recvmmsg (int fd, struct mmsghdr *vmessages, unsigned int vlen, int flags,
+	  const struct timespec *tmo)
+{
+  __set_errno (ENOSYS);
+  return -1;
+}
+stub_warning (recvmmsg)
+#endif
diff --git a/sysdeps/unix/sysv/linux/socketcall.h b/sysdeps/unix/sysv/linux/socketcall.h
index adf01b6..bab4e4a 100644
--- a/sysdeps/unix/sysv/linux/socketcall.h
+++ b/sysdeps/unix/sysv/linux/socketcall.h
@@ -44,5 +44,6 @@
 #define SOCKOP_sendmsg		16
 #define SOCKOP_recvmsg		17
 #define SOCKOP_accept4		18
+#define SOCKOP_recvmmsg		19
 
 #endif /* sys/socketcall.h */
diff --git a/sysdeps/unix/sysv/linux/syscalls.list b/sysdeps/unix/sysv/linux/syscalls.list
index a1a449e..a87906a 100644
--- a/sysdeps/unix/sysv/linux/syscalls.list
+++ b/sysdeps/unix/sysv/linux/syscalls.list
@@ -53,7 +53,6 @@ prctl		EXTRA	prctl		i:iiiii	__prctl		prctl
 putpmsg		-	putpmsg		i:ippii	putpmsg
 query_module	EXTRA	query_module	i:sipip	query_module
 quotactl	EXTRA	quotactl	i:isip	quotactl
-recvmmsg	EXTRA	recvmmsg	Ci:ipiip	recvmmsg
 remap_file_pages -	remap_file_pages i:piiii	__remap_file_pages remap_file_pages
 sched_getp	-	sched_getparam	i:ip	__sched_getparam	sched_getparam
 sched_gets	-	sched_getscheduler	i:i	__sched_getscheduler	sched_getscheduler
-- 
1.7.0.1


-- 
Andreas Schwab, schwab@redhat.com
GPG Key fingerprint = D4E8 DBE3 3813 BB5D FA84  5EC7 45C6 250E 6F00 984E
"And now for something completely different."