xref: /openbmc/linux/include/net/9p/client.h (revision be709d48)
1 /*
2  * include/net/9p/client.h
3  *
4  * 9P Client Definitions
5  *
6  *  Copyright (C) 2008 by Eric Van Hensbergen <ericvh@gmail.com>
7  *  Copyright (C) 2007 by Latchesar Ionkov <lucho@ionkov.net>
8  *
9  *  This program is free software; you can redistribute it and/or modify
10  *  it under the terms of the GNU General Public License version 2
11  *  as published by the Free Software Foundation.
12  *
13  *  This program is distributed in the hope that it will be useful,
14  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
15  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16  *  GNU General Public License for more details.
17  *
18  *  You should have received a copy of the GNU General Public License
19  *  along with this program; if not, write to:
20  *  Free Software Foundation
21  *  51 Franklin Street, Fifth Floor
22  *  Boston, MA  02111-1301  USA
23  *
24  */
25 
26 #ifndef NET_9P_CLIENT_H
27 #define NET_9P_CLIENT_H
28 
29 #include <linux/utsname.h>
30 #include <linux/idr.h>
31 
32 /* Number of requests per row */
33 #define P9_ROW_MAXTAG 255
34 
35 /** enum p9_proto_versions - 9P protocol versions
36  * @p9_proto_legacy: 9P Legacy mode, pre-9P2000.u
37  * @p9_proto_2000u: 9P2000.u extension
38  * @p9_proto_2000L: 9P2000.L extension
39  */
40 
41 enum p9_proto_versions{
42 	p9_proto_legacy,
43 	p9_proto_2000u,
44 	p9_proto_2000L,
45 };
46 
47 
48 /**
49  * enum p9_trans_status - different states of underlying transports
50  * @Connected: transport is connected and healthy
51  * @Disconnected: transport has been disconnected
52  * @Hung: transport is connected by wedged
53  *
54  * This enumeration details the various states a transport
55  * instatiation can be in.
56  */
57 
58 enum p9_trans_status {
59 	Connected,
60 	BeginDisconnect,
61 	Disconnected,
62 	Hung,
63 };
64 
65 /**
66  * enum p9_req_status_t - status of a request
67  * @REQ_STATUS_ALLOC: request has been allocated but not sent
68  * @REQ_STATUS_UNSENT: request waiting to be sent
69  * @REQ_STATUS_SENT: request sent to server
70  * @REQ_STATUS_RCVD: response received from server
71  * @REQ_STATUS_FLSHD: request has been flushed
72  * @REQ_STATUS_ERROR: request encountered an error on the client side
73  */
74 
75 enum p9_req_status_t {
76 	REQ_STATUS_ALLOC,
77 	REQ_STATUS_UNSENT,
78 	REQ_STATUS_SENT,
79 	REQ_STATUS_RCVD,
80 	REQ_STATUS_FLSHD,
81 	REQ_STATUS_ERROR,
82 };
83 
84 /**
85  * struct p9_req_t - request slots
86  * @status: status of this request slot
87  * @t_err: transport error
88  * @wq: wait_queue for the client to block on for this request
89  * @tc: the request fcall structure
90  * @rc: the response fcall structure
91  * @aux: transport specific data (provided for trans_fd migration)
92  * @req_list: link for higher level objects to chain requests
93  */
94 struct p9_req_t {
95 	int status;
96 	int t_err;
97 	struct kref refcount;
98 	wait_queue_head_t wq;
99 	struct p9_fcall tc;
100 	struct p9_fcall rc;
101 	void *aux;
102 	struct list_head req_list;
103 };
104 
105 /**
106  * struct p9_client - per client instance state
107  * @lock: protect @fids and @reqs
108  * @msize: maximum data size negotiated by protocol
109  * @proto_version: 9P protocol version to use
110  * @trans_mod: module API instantiated with this client
111  * @status: connection state
112  * @trans: tranport instance state and API
113  * @fids: All active FID handles
114  * @reqs: All active requests.
115  * @name: node name used as client id
116  *
117  * The client structure is used to keep track of various per-client
118  * state that has been instantiated.
119  */
120 struct p9_client {
121 	spinlock_t lock;
122 	unsigned int msize;
123 	unsigned char proto_version;
124 	struct p9_trans_module *trans_mod;
125 	enum p9_trans_status status;
126 	void *trans;
127 	struct kmem_cache *fcall_cache;
128 
129 	union {
130 		struct {
131 			int rfd;
132 			int wfd;
133 		} fd;
134 		struct {
135 			u16 port;
136 			bool privport;
137 
138 		} tcp;
139 	} trans_opts;
140 
141 	struct idr fids;
142 	struct idr reqs;
143 
144 	char name[__NEW_UTS_LEN + 1];
145 };
146 
147 /**
148  * struct p9_fid - file system entity handle
149  * @clnt: back pointer to instantiating &p9_client
150  * @fid: numeric identifier for this handle
151  * @mode: current mode of this fid (enum?)
152  * @qid: the &p9_qid server identifier this handle points to
153  * @iounit: the server reported maximum transaction size for this file
154  * @uid: the numeric uid of the local user who owns this handle
155  * @rdir: readdir accounting structure (allocated on demand)
156  * @dlist: per-dentry fid tracking
157  *
158  * TODO: This needs lots of explanation.
159  */
160 
161 struct p9_fid {
162 	struct p9_client *clnt;
163 	u32 fid;
164 	int mode;
165 	struct p9_qid qid;
166 	u32 iounit;
167 	kuid_t uid;
168 
169 	void *rdir;
170 
171 	struct hlist_node dlist;	/* list of all fids attached to a dentry */
172 };
173 
174 /**
175  * struct p9_dirent - directory entry structure
176  * @qid: The p9 server qid for this dirent
177  * @d_off: offset to the next dirent
178  * @d_type: type of file
179  * @d_name: file name
180  */
181 
182 struct p9_dirent {
183 	struct p9_qid qid;
184 	u64 d_off;
185 	unsigned char d_type;
186 	char d_name[256];
187 };
188 
189 struct iov_iter;
190 
191 int p9_show_client_options(struct seq_file *m, struct p9_client *clnt);
192 int p9_client_statfs(struct p9_fid *fid, struct p9_rstatfs *sb);
193 int p9_client_rename(struct p9_fid *fid, struct p9_fid *newdirfid,
194 		     const char *name);
195 int p9_client_renameat(struct p9_fid *olddirfid, const char *old_name,
196 		       struct p9_fid *newdirfid, const char *new_name);
197 struct p9_client *p9_client_create(const char *dev_name, char *options);
198 void p9_client_destroy(struct p9_client *clnt);
199 void p9_client_disconnect(struct p9_client *clnt);
200 void p9_client_begin_disconnect(struct p9_client *clnt);
201 struct p9_fid *p9_client_attach(struct p9_client *clnt, struct p9_fid *afid,
202 				const char *uname, kuid_t n_uname, const char *aname);
203 struct p9_fid *p9_client_walk(struct p9_fid *oldfid, uint16_t nwname,
204 		const unsigned char * const *wnames, int clone);
205 int p9_client_open(struct p9_fid *fid, int mode);
206 int p9_client_fcreate(struct p9_fid *fid, const char *name, u32 perm, int mode,
207 							char *extension);
208 int p9_client_link(struct p9_fid *fid, struct p9_fid *oldfid, const char *newname);
209 int p9_client_symlink(struct p9_fid *fid, const char *name, const char *symname,
210 		kgid_t gid, struct p9_qid *qid);
211 int p9_client_create_dotl(struct p9_fid *ofid, const char *name, u32 flags, u32 mode,
212 		kgid_t gid, struct p9_qid *qid);
213 int p9_client_clunk(struct p9_fid *fid);
214 int p9_client_fsync(struct p9_fid *fid, int datasync);
215 int p9_client_remove(struct p9_fid *fid);
216 int p9_client_unlinkat(struct p9_fid *dfid, const char *name, int flags);
217 int p9_client_read(struct p9_fid *fid, u64 offset, struct iov_iter *to, int *err);
218 int p9_client_write(struct p9_fid *fid, u64 offset, struct iov_iter *from, int *err);
219 int p9_client_readdir(struct p9_fid *fid, char *data, u32 count, u64 offset);
220 int p9dirent_read(struct p9_client *clnt, char *buf, int len,
221 		  struct p9_dirent *dirent);
222 struct p9_wstat *p9_client_stat(struct p9_fid *fid);
223 int p9_client_wstat(struct p9_fid *fid, struct p9_wstat *wst);
224 int p9_client_setattr(struct p9_fid *fid, struct p9_iattr_dotl *attr);
225 
226 struct p9_stat_dotl *p9_client_getattr_dotl(struct p9_fid *fid,
227 							u64 request_mask);
228 
229 int p9_client_mknod_dotl(struct p9_fid *oldfid, const char *name, int mode,
230 			dev_t rdev, kgid_t gid, struct p9_qid *);
231 int p9_client_mkdir_dotl(struct p9_fid *fid, const char *name, int mode,
232 				kgid_t gid, struct p9_qid *);
233 int p9_client_lock_dotl(struct p9_fid *fid, struct p9_flock *flock, u8 *status);
234 int p9_client_getlock_dotl(struct p9_fid *fid, struct p9_getlock *fl);
235 void p9_fcall_fini(struct p9_fcall *fc);
236 struct p9_req_t *p9_tag_lookup(struct p9_client *, u16);
237 
238 static inline void p9_req_get(struct p9_req_t *r)
239 {
240 	kref_get(&r->refcount);
241 }
242 
243 static inline int p9_req_try_get(struct p9_req_t *r)
244 {
245 	return kref_get_unless_zero(&r->refcount);
246 }
247 
248 int p9_req_put(struct p9_req_t *r);
249 
250 void p9_client_cb(struct p9_client *c, struct p9_req_t *req, int status);
251 
252 int p9_parse_header(struct p9_fcall *, int32_t *, int8_t *, int16_t *, int);
253 int p9stat_read(struct p9_client *, char *, int, struct p9_wstat *);
254 void p9stat_free(struct p9_wstat *);
255 
256 int p9_is_proto_dotu(struct p9_client *clnt);
257 int p9_is_proto_dotl(struct p9_client *clnt);
258 struct p9_fid *p9_client_xattrwalk(struct p9_fid *, const char *, u64 *);
259 int p9_client_xattrcreate(struct p9_fid *, const char *, u64, int);
260 int p9_client_readlink(struct p9_fid *fid, char **target);
261 
262 int p9_client_init(void);
263 void p9_client_exit(void);
264 
265 #endif /* NET_9P_CLIENT_H */
266