kernel-ark/fs/afs/proc.c
Pali Rohár 1bda2ac071 afs: proc cells and rootcell are writeable
Both proc files are writeable and used for configuring cells. But
there is missing correct mode flag for writeable files. Without
this patch both proc files are read only.

[ It turns out they aren't really read-only, since root can write to
  them even if the write bit isn't set due to CAP_DAC_OVERRIDE ]

Signed-off-by: Pali Rohár <pali.rohar@gmail.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-02-01 10:59:39 -08:00

667 lines
15 KiB
C

/* /proc interface for AFS
*
* Copyright (C) 2002 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/sched.h>
#include <asm/uaccess.h>
#include "internal.h"
static struct proc_dir_entry *proc_afs;
static int afs_proc_cells_open(struct inode *inode, struct file *file);
static void *afs_proc_cells_start(struct seq_file *p, loff_t *pos);
static void *afs_proc_cells_next(struct seq_file *p, void *v, loff_t *pos);
static void afs_proc_cells_stop(struct seq_file *p, void *v);
static int afs_proc_cells_show(struct seq_file *m, void *v);
static ssize_t afs_proc_cells_write(struct file *file, const char __user *buf,
size_t size, loff_t *_pos);
static const struct seq_operations afs_proc_cells_ops = {
.start = afs_proc_cells_start,
.next = afs_proc_cells_next,
.stop = afs_proc_cells_stop,
.show = afs_proc_cells_show,
};
static const struct file_operations afs_proc_cells_fops = {
.open = afs_proc_cells_open,
.read = seq_read,
.write = afs_proc_cells_write,
.llseek = seq_lseek,
.release = seq_release,
};
static ssize_t afs_proc_rootcell_read(struct file *file, char __user *buf,
size_t size, loff_t *_pos);
static ssize_t afs_proc_rootcell_write(struct file *file,
const char __user *buf,
size_t size, loff_t *_pos);
static const struct file_operations afs_proc_rootcell_fops = {
.read = afs_proc_rootcell_read,
.write = afs_proc_rootcell_write,
.llseek = no_llseek,
};
static int afs_proc_cell_volumes_open(struct inode *inode, struct file *file);
static void *afs_proc_cell_volumes_start(struct seq_file *p, loff_t *pos);
static void *afs_proc_cell_volumes_next(struct seq_file *p, void *v,
loff_t *pos);
static void afs_proc_cell_volumes_stop(struct seq_file *p, void *v);
static int afs_proc_cell_volumes_show(struct seq_file *m, void *v);
static const struct seq_operations afs_proc_cell_volumes_ops = {
.start = afs_proc_cell_volumes_start,
.next = afs_proc_cell_volumes_next,
.stop = afs_proc_cell_volumes_stop,
.show = afs_proc_cell_volumes_show,
};
static const struct file_operations afs_proc_cell_volumes_fops = {
.open = afs_proc_cell_volumes_open,
.read = seq_read,
.llseek = seq_lseek,
.release = seq_release,
};
static int afs_proc_cell_vlservers_open(struct inode *inode,
struct file *file);
static void *afs_proc_cell_vlservers_start(struct seq_file *p, loff_t *pos);
static void *afs_proc_cell_vlservers_next(struct seq_file *p, void *v,
loff_t *pos);
static void afs_proc_cell_vlservers_stop(struct seq_file *p, void *v);
static int afs_proc_cell_vlservers_show(struct seq_file *m, void *v);
static const struct seq_operations afs_proc_cell_vlservers_ops = {
.start = afs_proc_cell_vlservers_start,
.next = afs_proc_cell_vlservers_next,
.stop = afs_proc_cell_vlservers_stop,
.show = afs_proc_cell_vlservers_show,
};
static const struct file_operations afs_proc_cell_vlservers_fops = {
.open = afs_proc_cell_vlservers_open,
.read = seq_read,
.llseek = seq_lseek,
.release = seq_release,
};
static int afs_proc_cell_servers_open(struct inode *inode, struct file *file);
static void *afs_proc_cell_servers_start(struct seq_file *p, loff_t *pos);
static void *afs_proc_cell_servers_next(struct seq_file *p, void *v,
loff_t *pos);
static void afs_proc_cell_servers_stop(struct seq_file *p, void *v);
static int afs_proc_cell_servers_show(struct seq_file *m, void *v);
static const struct seq_operations afs_proc_cell_servers_ops = {
.start = afs_proc_cell_servers_start,
.next = afs_proc_cell_servers_next,
.stop = afs_proc_cell_servers_stop,
.show = afs_proc_cell_servers_show,
};
static const struct file_operations afs_proc_cell_servers_fops = {
.open = afs_proc_cell_servers_open,
.read = seq_read,
.llseek = seq_lseek,
.release = seq_release,
};
/*
* initialise the /proc/fs/afs/ directory
*/
int afs_proc_init(void)
{
_enter("");
proc_afs = proc_mkdir("fs/afs", NULL);
if (!proc_afs)
goto error_dir;
if (!proc_create("cells", 0644, proc_afs, &afs_proc_cells_fops) ||
!proc_create("rootcell", 0644, proc_afs, &afs_proc_rootcell_fops))
goto error_tree;
_leave(" = 0");
return 0;
error_tree:
remove_proc_subtree("fs/afs", NULL);
error_dir:
_leave(" = -ENOMEM");
return -ENOMEM;
}
/*
* clean up the /proc/fs/afs/ directory
*/
void afs_proc_cleanup(void)
{
remove_proc_subtree("fs/afs", NULL);
}
/*
* open "/proc/fs/afs/cells" which provides a summary of extant cells
*/
static int afs_proc_cells_open(struct inode *inode, struct file *file)
{
struct seq_file *m;
int ret;
ret = seq_open(file, &afs_proc_cells_ops);
if (ret < 0)
return ret;
m = file->private_data;
m->private = PDE_DATA(inode);
return 0;
}
/*
* set up the iterator to start reading from the cells list and return the
* first item
*/
static void *afs_proc_cells_start(struct seq_file *m, loff_t *_pos)
{
/* lock the list against modification */
down_read(&afs_proc_cells_sem);
return seq_list_start_head(&afs_proc_cells, *_pos);
}
/*
* move to next cell in cells list
*/
static void *afs_proc_cells_next(struct seq_file *p, void *v, loff_t *pos)
{
return seq_list_next(v, &afs_proc_cells, pos);
}
/*
* clean up after reading from the cells list
*/
static void afs_proc_cells_stop(struct seq_file *p, void *v)
{
up_read(&afs_proc_cells_sem);
}
/*
* display a header line followed by a load of cell lines
*/
static int afs_proc_cells_show(struct seq_file *m, void *v)
{
struct afs_cell *cell = list_entry(v, struct afs_cell, proc_link);
if (v == &afs_proc_cells) {
/* display header on line 1 */
seq_puts(m, "USE NAME\n");
return 0;
}
/* display one cell per line on subsequent lines */
seq_printf(m, "%3d %s\n",
atomic_read(&cell->usage), cell->name);
return 0;
}
/*
* handle writes to /proc/fs/afs/cells
* - to add cells: echo "add <cellname> <IP>[:<IP>][:<IP>]"
*/
static ssize_t afs_proc_cells_write(struct file *file, const char __user *buf,
size_t size, loff_t *_pos)
{
char *kbuf, *name, *args;
int ret;
/* start by dragging the command into memory */
if (size <= 1 || size >= PAGE_SIZE)
return -EINVAL;
kbuf = kmalloc(size + 1, GFP_KERNEL);
if (!kbuf)
return -ENOMEM;
ret = -EFAULT;
if (copy_from_user(kbuf, buf, size) != 0)
goto done;
kbuf[size] = 0;
/* trim to first NL */
name = memchr(kbuf, '\n', size);
if (name)
*name = 0;
/* split into command, name and argslist */
name = strchr(kbuf, ' ');
if (!name)
goto inval;
do {
*name++ = 0;
} while(*name == ' ');
if (!*name)
goto inval;
args = strchr(name, ' ');
if (!args)
goto inval;
do {
*args++ = 0;
} while(*args == ' ');
if (!*args)
goto inval;
/* determine command to perform */
_debug("cmd=%s name=%s args=%s", kbuf, name, args);
if (strcmp(kbuf, "add") == 0) {
struct afs_cell *cell;
cell = afs_cell_create(name, strlen(name), args, false);
if (IS_ERR(cell)) {
ret = PTR_ERR(cell);
goto done;
}
afs_put_cell(cell);
printk("kAFS: Added new cell '%s'\n", name);
} else {
goto inval;
}
ret = size;
done:
kfree(kbuf);
_leave(" = %d", ret);
return ret;
inval:
ret = -EINVAL;
printk("kAFS: Invalid Command on /proc/fs/afs/cells file\n");
goto done;
}
static ssize_t afs_proc_rootcell_read(struct file *file, char __user *buf,
size_t size, loff_t *_pos)
{
return 0;
}
/*
* handle writes to /proc/fs/afs/rootcell
* - to initialize rootcell: echo "cell.name:192.168.231.14"
*/
static ssize_t afs_proc_rootcell_write(struct file *file,
const char __user *buf,
size_t size, loff_t *_pos)
{
char *kbuf, *s;
int ret;
/* start by dragging the command into memory */
if (size <= 1 || size >= PAGE_SIZE)
return -EINVAL;
ret = -ENOMEM;
kbuf = kmalloc(size + 1, GFP_KERNEL);
if (!kbuf)
goto nomem;
ret = -EFAULT;
if (copy_from_user(kbuf, buf, size) != 0)
goto infault;
kbuf[size] = 0;
/* trim to first NL */
s = memchr(kbuf, '\n', size);
if (s)
*s = 0;
/* determine command to perform */
_debug("rootcell=%s", kbuf);
ret = afs_cell_init(kbuf);
if (ret >= 0)
ret = size; /* consume everything, always */
infault:
kfree(kbuf);
nomem:
_leave(" = %d", ret);
return ret;
}
/*
* initialise /proc/fs/afs/<cell>/
*/
int afs_proc_cell_setup(struct afs_cell *cell)
{
struct proc_dir_entry *dir;
_enter("%p{%s}", cell, cell->name);
dir = proc_mkdir(cell->name, proc_afs);
if (!dir)
goto error_dir;
if (!proc_create_data("servers", 0, dir,
&afs_proc_cell_servers_fops, cell) ||
!proc_create_data("vlservers", 0, dir,
&afs_proc_cell_vlservers_fops, cell) ||
!proc_create_data("volumes", 0, dir,
&afs_proc_cell_volumes_fops, cell))
goto error_tree;
_leave(" = 0");
return 0;
error_tree:
remove_proc_subtree(cell->name, proc_afs);
error_dir:
_leave(" = -ENOMEM");
return -ENOMEM;
}
/*
* remove /proc/fs/afs/<cell>/
*/
void afs_proc_cell_remove(struct afs_cell *cell)
{
_enter("");
remove_proc_subtree(cell->name, proc_afs);
_leave("");
}
/*
* open "/proc/fs/afs/<cell>/volumes" which provides a summary of extant cells
*/
static int afs_proc_cell_volumes_open(struct inode *inode, struct file *file)
{
struct afs_cell *cell;
struct seq_file *m;
int ret;
cell = PDE_DATA(inode);
if (!cell)
return -ENOENT;
ret = seq_open(file, &afs_proc_cell_volumes_ops);
if (ret < 0)
return ret;
m = file->private_data;
m->private = cell;
return 0;
}
/*
* set up the iterator to start reading from the cells list and return the
* first item
*/
static void *afs_proc_cell_volumes_start(struct seq_file *m, loff_t *_pos)
{
struct afs_cell *cell = m->private;
_enter("cell=%p pos=%Ld", cell, *_pos);
/* lock the list against modification */
down_read(&cell->vl_sem);
return seq_list_start_head(&cell->vl_list, *_pos);
}
/*
* move to next cell in cells list
*/
static void *afs_proc_cell_volumes_next(struct seq_file *p, void *v,
loff_t *_pos)
{
struct afs_cell *cell = p->private;
_enter("cell=%p pos=%Ld", cell, *_pos);
return seq_list_next(v, &cell->vl_list, _pos);
}
/*
* clean up after reading from the cells list
*/
static void afs_proc_cell_volumes_stop(struct seq_file *p, void *v)
{
struct afs_cell *cell = p->private;
up_read(&cell->vl_sem);
}
static const char afs_vlocation_states[][4] = {
[AFS_VL_NEW] = "New",
[AFS_VL_CREATING] = "Crt",
[AFS_VL_VALID] = "Val",
[AFS_VL_NO_VOLUME] = "NoV",
[AFS_VL_UPDATING] = "Upd",
[AFS_VL_VOLUME_DELETED] = "Del",
[AFS_VL_UNCERTAIN] = "Unc",
};
/*
* display a header line followed by a load of volume lines
*/
static int afs_proc_cell_volumes_show(struct seq_file *m, void *v)
{
struct afs_cell *cell = m->private;
struct afs_vlocation *vlocation =
list_entry(v, struct afs_vlocation, link);
/* display header on line 1 */
if (v == &cell->vl_list) {
seq_puts(m, "USE STT VLID[0] VLID[1] VLID[2] NAME\n");
return 0;
}
/* display one cell per line on subsequent lines */
seq_printf(m, "%3d %s %08x %08x %08x %s\n",
atomic_read(&vlocation->usage),
afs_vlocation_states[vlocation->state],
vlocation->vldb.vid[0],
vlocation->vldb.vid[1],
vlocation->vldb.vid[2],
vlocation->vldb.name);
return 0;
}
/*
* open "/proc/fs/afs/<cell>/vlservers" which provides a list of volume
* location server
*/
static int afs_proc_cell_vlservers_open(struct inode *inode, struct file *file)
{
struct afs_cell *cell;
struct seq_file *m;
int ret;
cell = PDE_DATA(inode);
if (!cell)
return -ENOENT;
ret = seq_open(file, &afs_proc_cell_vlservers_ops);
if (ret<0)
return ret;
m = file->private_data;
m->private = cell;
return 0;
}
/*
* set up the iterator to start reading from the cells list and return the
* first item
*/
static void *afs_proc_cell_vlservers_start(struct seq_file *m, loff_t *_pos)
{
struct afs_cell *cell = m->private;
loff_t pos = *_pos;
_enter("cell=%p pos=%Ld", cell, *_pos);
/* lock the list against modification */
down_read(&cell->vl_sem);
/* allow for the header line */
if (!pos)
return (void *) 1;
pos--;
if (pos >= cell->vl_naddrs)
return NULL;
return &cell->vl_addrs[pos];
}
/*
* move to next cell in cells list
*/
static void *afs_proc_cell_vlservers_next(struct seq_file *p, void *v,
loff_t *_pos)
{
struct afs_cell *cell = p->private;
loff_t pos;
_enter("cell=%p{nad=%u} pos=%Ld", cell, cell->vl_naddrs, *_pos);
pos = *_pos;
(*_pos)++;
if (pos >= cell->vl_naddrs)
return NULL;
return &cell->vl_addrs[pos];
}
/*
* clean up after reading from the cells list
*/
static void afs_proc_cell_vlservers_stop(struct seq_file *p, void *v)
{
struct afs_cell *cell = p->private;
up_read(&cell->vl_sem);
}
/*
* display a header line followed by a load of volume lines
*/
static int afs_proc_cell_vlservers_show(struct seq_file *m, void *v)
{
struct in_addr *addr = v;
/* display header on line 1 */
if (v == (struct in_addr *) 1) {
seq_puts(m, "ADDRESS\n");
return 0;
}
/* display one cell per line on subsequent lines */
seq_printf(m, "%pI4\n", &addr->s_addr);
return 0;
}
/*
* open "/proc/fs/afs/<cell>/servers" which provides a summary of active
* servers
*/
static int afs_proc_cell_servers_open(struct inode *inode, struct file *file)
{
struct afs_cell *cell;
struct seq_file *m;
int ret;
cell = PDE_DATA(inode);
if (!cell)
return -ENOENT;
ret = seq_open(file, &afs_proc_cell_servers_ops);
if (ret < 0)
return ret;
m = file->private_data;
m->private = cell;
return 0;
}
/*
* set up the iterator to start reading from the cells list and return the
* first item
*/
static void *afs_proc_cell_servers_start(struct seq_file *m, loff_t *_pos)
__acquires(m->private->servers_lock)
{
struct afs_cell *cell = m->private;
_enter("cell=%p pos=%Ld", cell, *_pos);
/* lock the list against modification */
read_lock(&cell->servers_lock);
return seq_list_start_head(&cell->servers, *_pos);
}
/*
* move to next cell in cells list
*/
static void *afs_proc_cell_servers_next(struct seq_file *p, void *v,
loff_t *_pos)
{
struct afs_cell *cell = p->private;
_enter("cell=%p pos=%Ld", cell, *_pos);
return seq_list_next(v, &cell->servers, _pos);
}
/*
* clean up after reading from the cells list
*/
static void afs_proc_cell_servers_stop(struct seq_file *p, void *v)
__releases(p->private->servers_lock)
{
struct afs_cell *cell = p->private;
read_unlock(&cell->servers_lock);
}
/*
* display a header line followed by a load of volume lines
*/
static int afs_proc_cell_servers_show(struct seq_file *m, void *v)
{
struct afs_cell *cell = m->private;
struct afs_server *server = list_entry(v, struct afs_server, link);
char ipaddr[20];
/* display header on line 1 */
if (v == &cell->servers) {
seq_puts(m, "USE ADDR STATE\n");
return 0;
}
/* display one cell per line on subsequent lines */
sprintf(ipaddr, "%pI4", &server->addr);
seq_printf(m, "%3d %-15.15s %5d\n",
atomic_read(&server->usage), ipaddr, server->fs_state);
return 0;
}