accept4: Implement cancellation

.. and add proper prototype, move it into it's own obj and other such
cleanups.

Signed-off-by: Bernhard Reutner-Fischer <rep.dot.nop@gmail.com>

include/sys/socket.h

@@ -227,6 +227,15 @@ extern int accept (int __fd, __SOCKADDR_ARG __addr,
 		   socklen_t *__restrict __addr_len);
 libc_hidden_proto(accept)
 
+#ifdef __USE_GNU
+/* Similar to 'accept' but takes an additional parameter to specify flags.
+
+   This function is a cancellation point and therefore not marked with
+   __THROW.  */
+extern int accept4 (int __fd, __SOCKADDR_ARG __addr,
+		    socklen_t *__restrict __addr_len, int __flags);
+#endif
+
 /* Shut down all or part of the connection open on socket FD.
    HOW determines what to shut down:
      SHUT_RD   = No more receptions;

libc/inet/Makefile.in

@@ -44,11 +44,13 @@ CSRC-$(findstring y,$(UCLIBC_HAS_IPV4)$(UCLIBC_HAS_IPV6)) += \
 ## CSRC-y += encodep.c decodep.c formquery.c
 
 # multi source socketcalls.c
-socketcalls_CSRC += \
+socketcalls_CSRC-y += \
 	accept.c bind.c connect.c getpeername.c getsockname.c \
 	getsockopt.c listen.c recv.c recvfrom.c recvmsg.c send.c sendmsg.c \
 	sendto.c setsockopt.c shutdown.c socket.c socketpair.c
-CSRC-$(UCLIBC_HAS_SOCKET) += $(socketcalls_CSRC) opensock.c
+# FIXME: GNU / linux specific
+socketcalls_CSRC-y += accept4.c
+CSRC-$(UCLIBC_HAS_SOCKET) += $(socketcalls_CSRC-y) opensock.c
 
 CSRC-$(findstring y,$(UCLIBC_HAS_SOCKET)$(UCLIBC_HAS_IPV4)$(UCLIBC_HAS_IPV6)) += ethers.c ether_addr.c
 

libc/inet/accept.c

@@ -5,5 +5,4 @@
  */
 
 #define L_accept
-#define L_accept4
 #include "socketcalls.c"

libc/inet/accept4.c

@@ -0,0 +1,8 @@
+/*
+ * Copyright (C) 2000-2006 Erik Andersen <andersen@uclibc.org>
+ *
+ * Licensed under the LGPL v2.1, see the file COPYING.LIB in this tarball.
+ */
+
+#define L_accept4
+#include "socketcalls.c"

libc/inet/socketcalls.c

@@ -83,6 +83,46 @@ weak_alias(__libc_accept,accept)
 libc_hidden_weak(accept)
 #endif
 
+#ifdef L_accept4
+#ifdef __NR_accept4
+# define __NR___sys_accept4  __NR_accept4
+static _syscall4(int, __sys_accept4, int, fd, struct sockaddr *, addr, socklen_t *, addrlen, int, flags)
+int accept4(int fd, struct sockaddr *addr, socklen_t * addrlen, int flags)
+{
+	if (SINGLE_THREAD_P)
+		return __sys_accept4(fd, addr, addrlen, flags);
+#ifdef __UCLIBC_HAS_THREADS_NATIVE__
+	else {
+		int oldtype = LIBC_CANCEL_ASYNC ();
+		int result = __sys_accept4(fd, addr, addrlen, flags);
+		LIBC_CANCEL_RESET (oldtype);
+		return result;
+	}
+#endif
+}
+#elif defined(__NR_socketcall)
+int accept4(int fd, struct sockaddr *addr, socklen_t *addrlen, int flags)
+{
+	unsigned long args[4];
+
+	args[0] = fd;
+	args[1] = (unsigned long) addr;
+	args[2] = (unsigned long) addrlen;
+	args[3] = flags;
+	if (SINGLE_THREAD_P)
+		return __socketcall(SYS_ACCEPT4, args);
+#ifdef __UCLIBC_HAS_THREADS_NATIVE__
+	else {
+		int oldtype = LIBC_CANCEL_ASYNC ();
+		int result = __socketcall(SYS_ACCEPT4, args);
+		LIBC_CANCEL_RESET (oldtype);
+		return result;
+	}
+#endif
+}
+#endif
+#endif
+
 #ifdef L_bind
 #ifdef __NR_bind
 _syscall3(int, bind, int, sockfd, const struct sockaddr *, myaddr, socklen_t, addrlen)
@@ -562,19 +602,3 @@ int socketpair(int family, int type, int protocol, int sockvec[2])
 #endif
 #endif
 
-#ifdef L_accept4
-#ifdef __NR_accept4
-_syscall4(int, accept4, int, sockfd, struct sockaddr *, addr, socklen_t *, addrlen, int, flags)
-#elif defined(__NR_socketcall)
-int accept4(int sockfd, struct sockaddr *addr, socklen_t *addrlen, int flags)
-{
-	unsigned long args[4];
-
-	args[0] = sockfd;
-	args[1] = (unsigned long) addr;
-	args[2] = (unsigned long) addrlen;
-	args[3] = flags;
-	return __socketcall(SYS_ACCEPT4, args);
-}
-#endif
-#endif

libc/sysdeps/linux/common/bits/kernel-features.h

@@ -454,6 +454,18 @@
 #define __ASSUME_IEEE_RAISE_EXCEPTION	1
 #endif
 
+/* Support for the accept4 syscall was added in 2.6.28.  */
+#if __LINUX_KERNEL_VERSION >= 0x02061c \
+    && (defined __i386__ || defined __x86_64__ || defined __powerpc__ \
+        || defined __sparc__ || defined __s390__)
+# define __ASSUME_ACCEPT4       1
+#endif
+
+/* Support for the accept4 syscall for alpha was added after 2.6.33-rc1.  */
+#if __LINUX_KERNEL_VERSION >= 0x020621 && defined __alpha__
+# define __ASSUME_ACCEPT4       1
+#endif
+
 /* Support for the FUTEX_CLOCK_REALTIME flag was added in 2.6.29.  */
 #if __LINUX_KERNEL_VERSION >= 0x02061d
 # define __ASSUME_FUTEX_CLOCK_REALTIME	1

libc/sysdeps/linux/common/stubs.c

@@ -31,6 +31,10 @@ static int enosys_stub(void)
 # undef __NR_sync_file_range
 #endif
 
+#ifndef __NR_accept4
+make_stub(accept4)
+#endif
+
 #ifndef __NR_bdflush
 make_stub(bdflush)
 #endif