android_kernel_xiaomi_sm8350/include/net/9p/client.h
Latchesar Ionkov ba17674fe0 9p: attach-per-user
The 9P2000 protocol requires the authentication and permission checks to be
done in the file server. For that reason every user that accesses the file
server tree has to authenticate and attach to the server separately.
Multiple users can share the same connection to the server.

Currently v9fs does a single attach and executes all I/O operations as a
single user. This makes using v9fs in multiuser environment unsafe as it
depends on the client doing the permission checking.

This patch improves the 9P2000 support by allowing every user to attach
separately. The patch defines three modes of access (new mount option
'access'):

- attach-per-user (access=user) (default mode for 9P2000.u)
 If a user tries to access a file served by v9fs for the first time, v9fs
 sends an attach command to the server (Tattach) specifying the user. If
 the attach succeeds, the user can access the v9fs tree.
 As there is no uname->uid (string->integer) mapping yet, this mode works
 only with the 9P2000.u dialect.

- allow only one user to access the tree (access=<uid>)
 Only the user with uid can access the v9fs tree. Other users that attempt
 to access it will get EPERM error.

- do all operations as a single user (access=any) (default for 9P2000)
 V9fs does a single attach and all operations are done as a single user.
 If this mode is selected, the v9fs behavior is identical with the current
 one.

Signed-off-by: Latchesar Ionkov <lucho@ionkov.net>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2007-10-17 14:31:07 -05:00

82 lines
2.6 KiB
C

/*
* include/net/9p/client.h
*
* 9P Client Definitions
*
* Copyright (C) 2007 by Latchesar Ionkov <lucho@ionkov.net>
*
* 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
*
*/
#ifndef NET_9P_CLIENT_H
#define NET_9P_CLIENT_H
struct p9_client {
spinlock_t lock; /* protect client structure */
int msize;
unsigned char dotu;
struct p9_trans *trans;
struct p9_conn *conn;
struct p9_idpool *fidpool;
struct list_head fidlist;
};
struct p9_fid {
struct p9_client *clnt;
u32 fid;
int mode;
struct p9_qid qid;
u32 iounit;
uid_t uid;
void *aux;
int rdir_fpos;
int rdir_pos;
struct p9_fcall *rdir_fcall;
struct list_head flist;
struct list_head dlist; /* list of all fids attached to a dentry */
};
struct p9_client *p9_client_create(struct p9_trans *trans, int msize,
int dotu);
void p9_client_destroy(struct p9_client *clnt);
void p9_client_disconnect(struct p9_client *clnt);
struct p9_fid *p9_client_attach(struct p9_client *clnt, struct p9_fid *afid,
char *uname, u32 n_uname, char *aname);
struct p9_fid *p9_client_auth(struct p9_client *clnt, char *uname,
u32 n_uname, char *aname);
struct p9_fid *p9_client_walk(struct p9_fid *oldfid, int nwname, char **wnames,
int clone);
int p9_client_open(struct p9_fid *fid, int mode);
int p9_client_fcreate(struct p9_fid *fid, char *name, u32 perm, int mode,
char *extension);
int p9_client_clunk(struct p9_fid *fid);
int p9_client_remove(struct p9_fid *fid);
int p9_client_read(struct p9_fid *fid, char *data, u64 offset, u32 count);
int p9_client_readn(struct p9_fid *fid, char *data, u64 offset, u32 count);
int p9_client_write(struct p9_fid *fid, char *data, u64 offset, u32 count);
int p9_client_uread(struct p9_fid *fid, char __user *data, u64 offset,
u32 count);
int p9_client_uwrite(struct p9_fid *fid, const char __user *data, u64 offset,
u32 count);
struct p9_stat *p9_client_stat(struct p9_fid *fid);
int p9_client_wstat(struct p9_fid *fid, struct p9_wstat *wst);
struct p9_stat *p9_client_dirread(struct p9_fid *fid, u64 offset);
#endif /* NET_9P_CLIENT_H */