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/*
* linux/fs/proc/fd.c
*
* Copyright (C) 1991, 1992 Linus Torvalds
*
* proc fd directory handling functions
*/
#include <asm/uaccess.h>
#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/proc_fs.h>
#include <linux/stat.h>
static int proc_readfd(struct inode *, struct file *, void *, filldir_t);
static int proc_lookupfd(struct inode *,const char *,int,struct inode **);
static struct file_operations proc_fd_operations = {
NULL, /* lseek - default */
NULL, /* read - bad */
NULL, /* write - bad */
proc_readfd, /* readdir */
NULL, /* poll - default */
NULL, /* ioctl - default */
NULL, /* mmap */
NULL, /* no special open code */
NULL, /* no special release code */
NULL /* can't fsync */
};
/*
* proc directories can do almost nothing..
*/
struct inode_operations proc_fd_inode_operations = {
&proc_fd_operations, /* default base directory file-ops */
NULL, /* create */
proc_lookupfd, /* lookup */
NULL, /* link */
NULL, /* unlink */
NULL, /* symlink */
NULL, /* mkdir */
NULL, /* rmdir */
NULL, /* mknod */
NULL, /* rename */
NULL, /* readlink */
NULL, /* follow_link */
NULL, /* readpage */
NULL, /* writepage */
NULL, /* bmap */
NULL, /* truncate */
NULL /* permission */
};
static int proc_lookupfd(struct inode * dir, const char * name, int len,
struct inode ** result)
{
unsigned int ino, pid, fd, c;
struct task_struct * p;
struct super_block * sb;
int i;
*result = NULL;
ino = dir->i_ino;
pid = ino >> 16;
ino &= 0x0000ffff;
if (!dir)
return -ENOENT;
sb = dir->i_sb;
if (!pid || ino != PROC_PID_FD || !S_ISDIR(dir->i_mode)) {
iput(dir);
return -ENOENT;
}
if (!len || (name[0] == '.' && (len == 1 ||
(name[1] == '.' && len == 2)))) {
if (len < 2) {
*result = dir;
return 0;
}
if (!(*result = proc_get_inode(sb, (pid << 16)+PROC_PID_INO, &proc_pid))) {
iput(dir);
return -ENOENT;
}
iput(dir);
return 0;
}
iput(dir);
fd = 0;
while (len-- > 0) {
c = *name - '0';
name++;
if (c > 9) {
fd = 0xfffff;
break;
}
fd *= 10;
fd += c;
if (fd & 0xffff0000) {
fd = 0xfffff;
break;
}
}
for (i = 0 ; i < NR_TASKS ; i++)
if ((p = task[i]) && p->pid == pid)
break;
if (!pid || i >= NR_TASKS)
return -ENOENT;
/*
* File handle is invalid if it is out of range, if the process
* has no files (Zombie) if the file is closed, or if its inode
* is NULL
*/
if (fd >= NR_OPEN || !p->files || !p->files->fd[fd] || !p->files->fd[fd]->f_inode)
return -ENOENT;
ino = (pid << 16) + (PROC_PID_FD_DIR << 8) + fd;
if (!(*result = proc_get_inode(sb, ino, NULL)))
return -ENOENT;
return 0;
}
#define NUMBUF 10
static int proc_readfd(struct inode * inode, struct file * filp,
void * dirent, filldir_t filldir)
{
char buf[NUMBUF];
int task_nr;
struct task_struct * p;
unsigned int fd, pid, ino;
unsigned long i,j;
if (!inode || !S_ISDIR(inode->i_mode))
return -EBADF;
ino = inode->i_ino;
pid = ino >> 16;
ino &= 0x0000ffff;
if (ino != PROC_PID_FD)
return 0;
for (fd = filp->f_pos; fd < 2; fd++, filp->f_pos++) {
unsigned long ino = inode->i_ino;
if (fd)
ino = (ino & 0xffff0000) | PROC_PID_INO;
if (filldir(dirent, "..", fd+1, fd, ino) < 0)
return 0;
}
task_nr = 1;
for (;;) {
if ((p = task[task_nr]) && p->pid == pid)
break;
if (++task_nr >= NR_TASKS)
return 0;
}
for (fd -= 2 ; fd < NR_OPEN; fd++, filp->f_pos++) {
if (!p->files)
break;
if (!p->files->fd[fd] || !p->files->fd[fd]->f_inode)
continue;
j = NUMBUF;
i = fd;
do {
j--;
buf[j] = '0' + (i % 10);
i /= 10;
} while (i);
ino = (pid << 16) + (PROC_PID_FD_DIR << 8) + fd;
if (filldir(dirent, buf+j, NUMBUF-j, fd+2, ino) < 0)
break;
/* filldir() might have slept, so we must re-validate "p" */
if (p != task[task_nr] || p->pid != pid)
break;
}
return 0;
}
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