ba17674fe0
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>
90 lines
2.7 KiB
C
90 lines
2.7 KiB
C
/*
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* V9FS definitions.
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*
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* Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
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* Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2
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* as published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to:
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* Free Software Foundation
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* 51 Franklin Street, Fifth Floor
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* Boston, MA 02111-1301 USA
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*
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*/
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/*
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* Session structure provides information for an opened session
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*
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*/
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struct v9fs_session_info {
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/* options */
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unsigned int maxdata;
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unsigned char flags; /* session flags */
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unsigned char nodev; /* set to 1 if no disable device mapping */
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unsigned short debug; /* debug level */
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unsigned int afid; /* authentication fid */
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unsigned int cache; /* cache mode */
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char *options; /* copy of mount options */
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char *uname; /* user name to mount as */
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char *aname; /* name of remote hierarchy being mounted */
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unsigned int dfltuid; /* default uid/muid for legacy support */
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unsigned int dfltgid; /* default gid for legacy support */
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u32 uid; /* if ACCESS_SINGLE, the uid that has access */
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struct p9_trans_module *trans; /* 9p transport */
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struct p9_client *clnt; /* 9p client */
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struct dentry *debugfs_dir;
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};
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/* session flags */
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enum {
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V9FS_EXTENDED = 0x01, /* 9P2000.u */
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V9FS_ACCESS_MASK = 0x06, /* access mask */
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V9FS_ACCESS_SINGLE = 0x02, /* only one user can access the files */
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V9FS_ACCESS_USER = 0x04, /* attache per user */
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V9FS_ACCESS_ANY = 0x06, /* use the same attach for all users */
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};
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/* possible values of ->cache */
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/* eventually support loose, tight, time, session, default always none */
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enum {
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CACHE_NONE, /* default */
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CACHE_LOOSE, /* no consistency */
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};
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extern struct dentry *v9fs_debugfs_root;
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struct p9_fid *v9fs_session_init(struct v9fs_session_info *, const char *,
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char *);
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void v9fs_session_close(struct v9fs_session_info *v9ses);
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void v9fs_session_cancel(struct v9fs_session_info *v9ses);
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#define V9FS_MAGIC 0x01021997
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/* other default globals */
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#define V9FS_PORT 564
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#define V9FS_DEFUSER "nobody"
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#define V9FS_DEFANAME ""
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#define V9FS_DEFUID (-2)
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#define V9FS_DEFGID (-2)
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static inline struct v9fs_session_info *v9fs_inode2v9ses(struct inode *inode)
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{
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return (inode->i_sb->s_fs_info);
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}
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static inline int v9fs_extended(struct v9fs_session_info *v9ses)
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{
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return v9ses->flags & V9FS_EXTENDED;
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}
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