linux/fs/9p/v9fs.c
Aneesh Kumar K.V 9ffaf63e34 fs/9p: Pass the correct user credentials during attach
We need to make sure we pass the right uid value
during attach. dotl is similar to dotu in this regard.
Without this mapped security model on dotl doesn't work

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2010-08-02 14:25:08 -05:00

507 lines
11 KiB
C

/*
* linux/fs/9p/v9fs.c
*
* This file contains functions assisting in mapping VFS to 9P2000
*
* Copyright (C) 2004-2008 by Eric Van Hensbergen <ericvh@gmail.com>
* Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2
* as published by the Free Software Foundation.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to:
* Free Software Foundation
* 51 Franklin Street, Fifth Floor
* Boston, MA 02111-1301 USA
*
*/
#include <linux/module.h>
#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/sched.h>
#include <linux/parser.h>
#include <linux/idr.h>
#include <linux/slab.h>
#include <net/9p/9p.h>
#include <net/9p/client.h>
#include <net/9p/transport.h>
#include "v9fs.h"
#include "v9fs_vfs.h"
#include "cache.h"
static DEFINE_SPINLOCK(v9fs_sessionlist_lock);
static LIST_HEAD(v9fs_sessionlist);
/*
* Option Parsing (code inspired by NFS code)
* NOTE: each transport will parse its own options
*/
enum {
/* Options that take integer arguments */
Opt_debug, Opt_dfltuid, Opt_dfltgid, Opt_afid,
/* String options */
Opt_uname, Opt_remotename, Opt_trans, Opt_cache, Opt_cachetag,
/* Options that take no arguments */
Opt_nodevmap,
/* Cache options */
Opt_cache_loose, Opt_fscache,
/* Access options */
Opt_access,
/* Error token */
Opt_err
};
static const match_table_t tokens = {
{Opt_debug, "debug=%x"},
{Opt_dfltuid, "dfltuid=%u"},
{Opt_dfltgid, "dfltgid=%u"},
{Opt_afid, "afid=%u"},
{Opt_uname, "uname=%s"},
{Opt_remotename, "aname=%s"},
{Opt_nodevmap, "nodevmap"},
{Opt_cache, "cache=%s"},
{Opt_cache_loose, "loose"},
{Opt_fscache, "fscache"},
{Opt_cachetag, "cachetag=%s"},
{Opt_access, "access=%s"},
{Opt_err, NULL}
};
/**
* v9fs_parse_options - parse mount options into session structure
* @v9ses: existing v9fs session information
*
* Return 0 upon success, -ERRNO upon failure.
*/
static int v9fs_parse_options(struct v9fs_session_info *v9ses, char *opts)
{
char *options, *tmp_options;
substring_t args[MAX_OPT_ARGS];
char *p;
int option = 0;
char *s, *e;
int ret = 0;
/* setup defaults */
v9ses->afid = ~0;
v9ses->debug = 0;
v9ses->cache = 0;
#ifdef CONFIG_9P_FSCACHE
v9ses->cachetag = NULL;
#endif
if (!opts)
return 0;
tmp_options = kstrdup(opts, GFP_KERNEL);
if (!tmp_options) {
ret = -ENOMEM;
goto fail_option_alloc;
}
options = tmp_options;
while ((p = strsep(&options, ",")) != NULL) {
int token;
if (!*p)
continue;
token = match_token(p, tokens, args);
if (token < Opt_uname) {
int r = match_int(&args[0], &option);
if (r < 0) {
P9_DPRINTK(P9_DEBUG_ERROR,
"integer field, but no integer?\n");
ret = r;
continue;
}
}
switch (token) {
case Opt_debug:
v9ses->debug = option;
#ifdef CONFIG_NET_9P_DEBUG
p9_debug_level = option;
#endif
break;
case Opt_dfltuid:
v9ses->dfltuid = option;
break;
case Opt_dfltgid:
v9ses->dfltgid = option;
break;
case Opt_afid:
v9ses->afid = option;
break;
case Opt_uname:
match_strlcpy(v9ses->uname, &args[0], PATH_MAX);
break;
case Opt_remotename:
match_strlcpy(v9ses->aname, &args[0], PATH_MAX);
break;
case Opt_nodevmap:
v9ses->nodev = 1;
break;
case Opt_cache_loose:
v9ses->cache = CACHE_LOOSE;
break;
case Opt_fscache:
v9ses->cache = CACHE_FSCACHE;
break;
case Opt_cachetag:
#ifdef CONFIG_9P_FSCACHE
v9ses->cachetag = match_strdup(&args[0]);
#endif
break;
case Opt_cache:
s = match_strdup(&args[0]);
if (!s) {
ret = -ENOMEM;
P9_DPRINTK(P9_DEBUG_ERROR,
"problem allocating copy of cache arg\n");
goto free_and_return;
}
if (strcmp(s, "loose") == 0)
v9ses->cache = CACHE_LOOSE;
else if (strcmp(s, "fscache") == 0)
v9ses->cache = CACHE_FSCACHE;
else
v9ses->cache = CACHE_NONE;
kfree(s);
break;
case Opt_access:
s = match_strdup(&args[0]);
if (!s) {
ret = -ENOMEM;
P9_DPRINTK(P9_DEBUG_ERROR,
"problem allocating copy of access arg\n");
goto free_and_return;
}
v9ses->flags &= ~V9FS_ACCESS_MASK;
if (strcmp(s, "user") == 0)
v9ses->flags |= V9FS_ACCESS_USER;
else if (strcmp(s, "any") == 0)
v9ses->flags |= V9FS_ACCESS_ANY;
else {
v9ses->flags |= V9FS_ACCESS_SINGLE;
v9ses->uid = simple_strtoul(s, &e, 10);
if (*e != '\0')
v9ses->uid = ~0;
}
kfree(s);
break;
default:
continue;
}
}
free_and_return:
kfree(tmp_options);
fail_option_alloc:
return ret;
}
/**
* v9fs_session_init - initialize session
* @v9ses: session information structure
* @dev_name: device being mounted
* @data: options
*
*/
struct p9_fid *v9fs_session_init(struct v9fs_session_info *v9ses,
const char *dev_name, char *data)
{
int retval = -EINVAL;
struct p9_fid *fid;
int rc;
v9ses->uname = __getname();
if (!v9ses->uname)
return ERR_PTR(-ENOMEM);
v9ses->aname = __getname();
if (!v9ses->aname) {
__putname(v9ses->uname);
return ERR_PTR(-ENOMEM);
}
rc = bdi_setup_and_register(&v9ses->bdi, "9p", BDI_CAP_MAP_COPY);
if (rc) {
__putname(v9ses->aname);
__putname(v9ses->uname);
return ERR_PTR(rc);
}
spin_lock(&v9fs_sessionlist_lock);
list_add(&v9ses->slist, &v9fs_sessionlist);
spin_unlock(&v9fs_sessionlist_lock);
v9ses->flags = V9FS_ACCESS_USER;
strcpy(v9ses->uname, V9FS_DEFUSER);
strcpy(v9ses->aname, V9FS_DEFANAME);
v9ses->uid = ~0;
v9ses->dfltuid = V9FS_DEFUID;
v9ses->dfltgid = V9FS_DEFGID;
rc = v9fs_parse_options(v9ses, data);
if (rc < 0) {
retval = rc;
goto error;
}
v9ses->clnt = p9_client_create(dev_name, data);
if (IS_ERR(v9ses->clnt)) {
retval = PTR_ERR(v9ses->clnt);
v9ses->clnt = NULL;
P9_DPRINTK(P9_DEBUG_ERROR, "problem initializing 9p client\n");
goto error;
}
if (p9_is_proto_dotl(v9ses->clnt))
v9ses->flags |= V9FS_PROTO_2000L;
else if (p9_is_proto_dotu(v9ses->clnt))
v9ses->flags |= V9FS_PROTO_2000U;
v9ses->maxdata = v9ses->clnt->msize - P9_IOHDRSZ;
/* for legacy mode, fall back to V9FS_ACCESS_ANY */
if (!(v9fs_proto_dotu(v9ses) || v9fs_proto_dotl(v9ses)) &&
((v9ses->flags&V9FS_ACCESS_MASK) == V9FS_ACCESS_USER)) {
v9ses->flags &= ~V9FS_ACCESS_MASK;
v9ses->flags |= V9FS_ACCESS_ANY;
v9ses->uid = ~0;
}
fid = p9_client_attach(v9ses->clnt, NULL, v9ses->uname, ~0,
v9ses->aname);
if (IS_ERR(fid)) {
retval = PTR_ERR(fid);
fid = NULL;
P9_DPRINTK(P9_DEBUG_ERROR, "cannot attach\n");
goto error;
}
if ((v9ses->flags & V9FS_ACCESS_MASK) == V9FS_ACCESS_SINGLE)
fid->uid = v9ses->uid;
else
fid->uid = ~0;
#ifdef CONFIG_9P_FSCACHE
/* register the session for caching */
v9fs_cache_session_get_cookie(v9ses);
#endif
return fid;
error:
bdi_destroy(&v9ses->bdi);
return ERR_PTR(retval);
}
/**
* v9fs_session_close - shutdown a session
* @v9ses: session information structure
*
*/
void v9fs_session_close(struct v9fs_session_info *v9ses)
{
if (v9ses->clnt) {
p9_client_destroy(v9ses->clnt);
v9ses->clnt = NULL;
}
#ifdef CONFIG_9P_FSCACHE
if (v9ses->fscache) {
v9fs_cache_session_put_cookie(v9ses);
kfree(v9ses->cachetag);
}
#endif
__putname(v9ses->uname);
__putname(v9ses->aname);
bdi_destroy(&v9ses->bdi);
spin_lock(&v9fs_sessionlist_lock);
list_del(&v9ses->slist);
spin_unlock(&v9fs_sessionlist_lock);
}
/**
* v9fs_session_cancel - terminate a session
* @v9ses: session to terminate
*
* mark transport as disconnected and cancel all pending requests.
*/
void v9fs_session_cancel(struct v9fs_session_info *v9ses) {
P9_DPRINTK(P9_DEBUG_ERROR, "cancel session %p\n", v9ses);
p9_client_disconnect(v9ses->clnt);
}
/**
* v9fs_session_begin_cancel - Begin terminate of a session
* @v9ses: session to terminate
*
* After this call we don't allow any request other than clunk.
*/
void v9fs_session_begin_cancel(struct v9fs_session_info *v9ses)
{
P9_DPRINTK(P9_DEBUG_ERROR, "begin cancel session %p\n", v9ses);
p9_client_begin_disconnect(v9ses->clnt);
}
extern int v9fs_error_init(void);
static struct kobject *v9fs_kobj;
#ifdef CONFIG_9P_FSCACHE
/**
* caches_show - list caches associated with a session
*
* Returns the size of buffer written.
*/
static ssize_t caches_show(struct kobject *kobj,
struct kobj_attribute *attr,
char *buf)
{
ssize_t n = 0, count = 0, limit = PAGE_SIZE;
struct v9fs_session_info *v9ses;
spin_lock(&v9fs_sessionlist_lock);
list_for_each_entry(v9ses, &v9fs_sessionlist, slist) {
if (v9ses->cachetag) {
n = snprintf(buf, limit, "%s\n", v9ses->cachetag);
if (n < 0) {
count = n;
break;
}
count += n;
limit -= n;
}
}
spin_unlock(&v9fs_sessionlist_lock);
return count;
}
static struct kobj_attribute v9fs_attr_cache = __ATTR_RO(caches);
#endif /* CONFIG_9P_FSCACHE */
static struct attribute *v9fs_attrs[] = {
#ifdef CONFIG_9P_FSCACHE
&v9fs_attr_cache.attr,
#endif
NULL,
};
static struct attribute_group v9fs_attr_group = {
.attrs = v9fs_attrs,
};
/**
* v9fs_sysfs_init - Initialize the v9fs sysfs interface
*
*/
static int v9fs_sysfs_init(void)
{
v9fs_kobj = kobject_create_and_add("9p", fs_kobj);
if (!v9fs_kobj)
return -ENOMEM;
if (sysfs_create_group(v9fs_kobj, &v9fs_attr_group)) {
kobject_put(v9fs_kobj);
return -ENOMEM;
}
return 0;
}
/**
* v9fs_sysfs_cleanup - Unregister the v9fs sysfs interface
*
*/
static void v9fs_sysfs_cleanup(void)
{
sysfs_remove_group(v9fs_kobj, &v9fs_attr_group);
kobject_put(v9fs_kobj);
}
/**
* init_v9fs - Initialize module
*
*/
static int __init init_v9fs(void)
{
int err;
printk(KERN_INFO "Installing v9fs 9p2000 file system support\n");
/* TODO: Setup list of registered trasnport modules */
err = register_filesystem(&v9fs_fs_type);
if (err < 0) {
printk(KERN_ERR "Failed to register filesystem\n");
return err;
}
err = v9fs_cache_register();
if (err < 0) {
printk(KERN_ERR "Failed to register v9fs for caching\n");
goto out_fs_unreg;
}
err = v9fs_sysfs_init();
if (err < 0) {
printk(KERN_ERR "Failed to register with sysfs\n");
goto out_sysfs_cleanup;
}
return 0;
out_sysfs_cleanup:
v9fs_sysfs_cleanup();
out_fs_unreg:
unregister_filesystem(&v9fs_fs_type);
return err;
}
/**
* exit_v9fs - shutdown module
*
*/
static void __exit exit_v9fs(void)
{
v9fs_sysfs_cleanup();
v9fs_cache_unregister();
unregister_filesystem(&v9fs_fs_type);
}
module_init(init_v9fs)
module_exit(exit_v9fs)
MODULE_AUTHOR("Latchesar Ionkov <lucho@ionkov.net>");
MODULE_AUTHOR("Eric Van Hensbergen <ericvh@gmail.com>");
MODULE_AUTHOR("Ron Minnich <rminnich@lanl.gov>");
MODULE_LICENSE("GPL");