1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3 * 9P Client Definitions
4 *
5 * Copyright (C) 2008 by Eric Van Hensbergen <ericvh@gmail.com>
6 * Copyright (C) 2007 by Latchesar Ionkov <lucho@ionkov.net>
7 */
8
9 #ifndef NET_9P_CLIENT_H
10 #define NET_9P_CLIENT_H
11
12 #include <linux/utsname.h>
13 #include <linux/idr.h>
14
15 /* Number of requests per row */
16 #define P9_ROW_MAXTAG 255
17
18 /** enum p9_proto_versions - 9P protocol versions
19 * @p9_proto_legacy: 9P Legacy mode, pre-9P2000.u
20 * @p9_proto_2000u: 9P2000.u extension
21 * @p9_proto_2000L: 9P2000.L extension
22 */
23
24 enum p9_proto_versions {
25 p9_proto_legacy,
26 p9_proto_2000u,
27 p9_proto_2000L,
28 };
29
30
31 /**
32 * enum p9_trans_status - different states of underlying transports
33 * @Connected: transport is connected and healthy
34 * @Disconnected: transport has been disconnected
35 * @Hung: transport is connected by wedged
36 *
37 * This enumeration details the various states a transport
38 * instatiation can be in.
39 */
40
41 enum p9_trans_status {
42 Connected,
43 BeginDisconnect,
44 Disconnected,
45 Hung,
46 };
47
48 /**
49 * enum p9_req_status_t - status of a request
50 * @REQ_STATUS_ALLOC: request has been allocated but not sent
51 * @REQ_STATUS_UNSENT: request waiting to be sent
52 * @REQ_STATUS_SENT: request sent to server
53 * @REQ_STATUS_RCVD: response received from server
54 * @REQ_STATUS_FLSHD: request has been flushed
55 * @REQ_STATUS_ERROR: request encountered an error on the client side
56 */
57
58 enum p9_req_status_t {
59 REQ_STATUS_ALLOC,
60 REQ_STATUS_UNSENT,
61 REQ_STATUS_SENT,
62 REQ_STATUS_RCVD,
63 REQ_STATUS_FLSHD,
64 REQ_STATUS_ERROR,
65 };
66
67 /**
68 * struct p9_req_t - request slots
69 * @status: status of this request slot
70 * @t_err: transport error
71 * @wq: wait_queue for the client to block on for this request
72 * @tc: the request fcall structure
73 * @rc: the response fcall structure
74 * @req_list: link for higher level objects to chain requests
75 */
76 struct p9_req_t {
77 int status;
78 int t_err;
79 refcount_t refcount;
80 wait_queue_head_t wq;
81 struct p9_fcall tc;
82 struct p9_fcall rc;
83 struct list_head req_list;
84 };
85
86 /**
87 * struct p9_client - per client instance state
88 * @lock: protect @fids and @reqs
89 * @msize: maximum data size negotiated by protocol
90 * @proto_version: 9P protocol version to use
91 * @trans_mod: module API instantiated with this client
92 * @status: connection state
93 * @trans: tranport instance state and API
94 * @fids: All active FID handles
95 * @reqs: All active requests.
96 * @name: node name used as client id
97 *
98 * The client structure is used to keep track of various per-client
99 * state that has been instantiated.
100 */
101 struct p9_client {
102 spinlock_t lock;
103 unsigned int msize;
104 unsigned char proto_version;
105 struct p9_trans_module *trans_mod;
106 enum p9_trans_status status;
107 void *trans;
108 struct kmem_cache *fcall_cache;
109
110 union {
111 struct {
112 int rfd;
113 int wfd;
114 } fd;
115 struct {
116 u16 port;
117 bool privport;
118
119 } tcp;
120 } trans_opts;
121
122 struct idr fids;
123 struct idr reqs;
124
125 char name[__NEW_UTS_LEN + 1];
126 };
127
128 /**
129 * struct p9_fid - file system entity handle
130 * @clnt: back pointer to instantiating &p9_client
131 * @fid: numeric identifier for this handle
132 * @mode: current mode of this fid (enum?)
133 * @qid: the &p9_qid server identifier this handle points to
134 * @iounit: the server reported maximum transaction size for this file
135 * @uid: the numeric uid of the local user who owns this handle
136 * @rdir: readdir accounting structure (allocated on demand)
137 * @dlist: per-dentry fid tracking
138 *
139 * TODO: This needs lots of explanation.
140 */
141 enum fid_source {
142 FID_FROM_OTHER,
143 FID_FROM_INODE,
144 FID_FROM_DENTRY,
145 };
146
147 struct p9_fid {
148 struct p9_client *clnt;
149 u32 fid;
150 refcount_t count;
151 int mode;
152 struct p9_qid qid;
153 u32 iounit;
154 kuid_t uid;
155
156 void *rdir;
157
158 struct hlist_node dlist; /* list of all fids attached to a dentry */
159 struct hlist_node ilist;
160 };
161
162 /**
163 * struct p9_dirent - directory entry structure
164 * @qid: The p9 server qid for this dirent
165 * @d_off: offset to the next dirent
166 * @d_type: type of file
167 * @d_name: file name
168 */
169
170 struct p9_dirent {
171 struct p9_qid qid;
172 u64 d_off;
173 unsigned char d_type;
174 char d_name[256];
175 };
176
177 struct iov_iter;
178
179 int p9_show_client_options(struct seq_file *m, struct p9_client *clnt);
180 int p9_client_statfs(struct p9_fid *fid, struct p9_rstatfs *sb);
181 int p9_client_rename(struct p9_fid *fid, struct p9_fid *newdirfid,
182 const char *name);
183 int p9_client_renameat(struct p9_fid *olddirfid, const char *old_name,
184 struct p9_fid *newdirfid, const char *new_name);
185 struct p9_client *p9_client_create(const char *dev_name, char *options);
186 void p9_client_destroy(struct p9_client *clnt);
187 void p9_client_disconnect(struct p9_client *clnt);
188 void p9_client_begin_disconnect(struct p9_client *clnt);
189 struct p9_fid *p9_client_attach(struct p9_client *clnt, struct p9_fid *afid,
190 const char *uname, kuid_t n_uname, const char *aname);
191 struct p9_fid *p9_client_walk(struct p9_fid *oldfid, uint16_t nwname,
192 const unsigned char * const *wnames, int clone);
193 int p9_client_open(struct p9_fid *fid, int mode);
194 int p9_client_fcreate(struct p9_fid *fid, const char *name, u32 perm, int mode,
195 char *extension);
196 int p9_client_link(struct p9_fid *fid, struct p9_fid *oldfid, const char *newname);
197 int p9_client_symlink(struct p9_fid *fid, const char *name, const char *symname,
198 kgid_t gid, struct p9_qid *qid);
199 int p9_client_create_dotl(struct p9_fid *ofid, const char *name, u32 flags, u32 mode,
200 kgid_t gid, struct p9_qid *qid);
201 int p9_client_clunk(struct p9_fid *fid);
202 int p9_client_fsync(struct p9_fid *fid, int datasync);
203 int p9_client_remove(struct p9_fid *fid);
204 int p9_client_unlinkat(struct p9_fid *dfid, const char *name, int flags);
205 int p9_client_read(struct p9_fid *fid, u64 offset, struct iov_iter *to, int *err);
206 int p9_client_read_once(struct p9_fid *fid, u64 offset, struct iov_iter *to,
207 int *err);
208 int p9_client_write(struct p9_fid *fid, u64 offset, struct iov_iter *from, int *err);
209 int p9_client_readdir(struct p9_fid *fid, char *data, u32 count, u64 offset);
210 int p9dirent_read(struct p9_client *clnt, char *buf, int len,
211 struct p9_dirent *dirent);
212 struct p9_wstat *p9_client_stat(struct p9_fid *fid);
213 int p9_client_wstat(struct p9_fid *fid, struct p9_wstat *wst);
214 int p9_client_setattr(struct p9_fid *fid, struct p9_iattr_dotl *attr);
215
216 struct p9_stat_dotl *p9_client_getattr_dotl(struct p9_fid *fid,
217 u64 request_mask);
218
219 int p9_client_mknod_dotl(struct p9_fid *oldfid, const char *name, int mode,
220 dev_t rdev, kgid_t gid, struct p9_qid *qid);
221 int p9_client_mkdir_dotl(struct p9_fid *fid, const char *name, int mode,
222 kgid_t gid, struct p9_qid *qid);
223 int p9_client_lock_dotl(struct p9_fid *fid, struct p9_flock *flock, u8 *status);
224 int p9_client_getlock_dotl(struct p9_fid *fid, struct p9_getlock *fl);
225 void p9_fcall_fini(struct p9_fcall *fc);
226 struct p9_req_t *p9_tag_lookup(struct p9_client *c, u16 tag);
227
p9_req_get(struct p9_req_t * r)228 static inline void p9_req_get(struct p9_req_t *r)
229 {
230 refcount_inc(&r->refcount);
231 }
232
p9_req_try_get(struct p9_req_t * r)233 static inline int p9_req_try_get(struct p9_req_t *r)
234 {
235 return refcount_inc_not_zero(&r->refcount);
236 }
237
238 int p9_req_put(struct p9_client *c, struct p9_req_t *r);
239
240 void p9_client_cb(struct p9_client *c, struct p9_req_t *req, int status);
241
242 int p9_parse_header(struct p9_fcall *pdu, int32_t *size, int8_t *type,
243 int16_t *tag, int rewind);
244 int p9stat_read(struct p9_client *clnt, char *buf, int len,
245 struct p9_wstat *st);
246 void p9stat_free(struct p9_wstat *stbuf);
247
248 int p9_is_proto_dotu(struct p9_client *clnt);
249 int p9_is_proto_dotl(struct p9_client *clnt);
250 struct p9_fid *p9_client_xattrwalk(struct p9_fid *file_fid,
251 const char *attr_name, u64 *attr_size);
252 int p9_client_xattrcreate(struct p9_fid *fid, const char *name,
253 u64 attr_size, int flags);
254 int p9_client_readlink(struct p9_fid *fid, char **target);
255
256 int p9_client_init(void);
257 void p9_client_exit(void);
258
259 #endif /* NET_9P_CLIENT_H */
260