socket.s

一个C源代码分析器

/* Copyright (C) 1991, 1992 Free Software Foundation, Inc.
This file is part of the GNU C Library.

The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public License as
published by the Free Software Foundation; either version 2 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
Library General Public License for more details.

You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB.  If
not, write to the Free Software Foundation, Inc., 675 Mass Ave,
Cambridge, MA 02139, USA.  */

#include <sysdep.h>

.globl syscall_error

/* The socket-oriented system calls are handled unusally in Linux.
   They are all gated through the single `socketcall' system call number.
   `socketcall' takes two arguments: the first is the subcode, specifying
   which socket function is being called; and the second is a pointer to
   the arguments to specific function.

   The .S files for the other calls just #define socket and #include this.  */

ENTRY (socket)

	/* Save registers.  */
	pushl %ebx
	pushl %ecx

	movl $__NR_socketcall, %eax	/* System call number in %eax.  */

	/* Use ## so `socket' is a separate token that might be #define'd.  */
	movl $SYS_##socket, %ebx	/* Subcode is first arg to syscall.  */
	lea 12(%esp), %ecx		/* Address of args in 2nd arg.  */

        /* Do the system call trap.  */
	int $0x80

	/* Restore registers.  */
	popl %ecx
	popl %ebx

	/* %eax is < 0 if there was an error.  */
	testl %eax, %eax
	jl syscall_error

	/* Successful; return the syscall's value.  */
	ret