securityos/public/Users/Public/Sistemas/1º Linux/Linux-0.0.1/fs/fcntl.c

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2024-09-06 15:32:35 +00:00
#include <string.h>
#include <errno.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <asm/segment.h>
#include <fcntl.h>
#include <sys/stat.h>
extern int sys_close(int fd);
static int dupfd(unsigned int fd, unsigned int arg)
{
if (fd >= NR_OPEN || !current->filp[fd])
return -EBADF;
if (arg >= NR_OPEN)
return -EINVAL;
while (arg < NR_OPEN)
if (current->filp[arg])
arg++;
else
break;
if (arg >= NR_OPEN)
return -EMFILE;
current->close_on_exec &= ~(1<<arg);
(current->filp[arg] = current->filp[fd])->f_count++;
return arg;
}
int sys_dup2(unsigned int oldfd, unsigned int newfd)
{
sys_close(newfd);
return dupfd(oldfd,newfd);
}
int sys_dup(unsigned int fildes)
{
return dupfd(fildes,0);
}
int sys_fcntl(unsigned int fd, unsigned int cmd, unsigned long arg)
{
struct file * filp;
if (fd >= NR_OPEN || !(filp = current->filp[fd]))
return -EBADF;
switch (cmd) {
case F_DUPFD:
return dupfd(fd,arg);
case F_GETFD:
return (current->close_on_exec>>fd)&1;
case F_SETFD:
if (arg&1)
current->close_on_exec |= (1<<fd);
else
current->close_on_exec &= ~(1<<fd);
return 0;
case F_GETFL:
return filp->f_flags;
case F_SETFL:
filp->f_flags &= ~(O_APPEND | O_NONBLOCK);
filp->f_flags |= arg & (O_APPEND | O_NONBLOCK);
return 0;
case F_GETLK: case F_SETLK: case F_SETLKW:
return -1;
default:
return -1;
}
}