xref: /openbmc/linux/include/net/9p/client.h (revision aa1d19f1)
1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3  * include/net/9p/client.h
4  *
5  * 9P Client Definitions
6  *
7  *  Copyright (C) 2008 by Eric Van Hensbergen <ericvh@gmail.com>
8  *  Copyright (C) 2007 by Latchesar Ionkov <lucho@ionkov.net>
9  */
10 
11 #ifndef NET_9P_CLIENT_H
12 #define NET_9P_CLIENT_H
13 
14 #include <linux/utsname.h>
15 #include <linux/idr.h>
16 
17 /* Number of requests per row */
18 #define P9_ROW_MAXTAG 255
19 
20 /** enum p9_proto_versions - 9P protocol versions
21  * @p9_proto_legacy: 9P Legacy mode, pre-9P2000.u
22  * @p9_proto_2000u: 9P2000.u extension
23  * @p9_proto_2000L: 9P2000.L extension
24  */
25 
26 enum p9_proto_versions{
27 	p9_proto_legacy,
28 	p9_proto_2000u,
29 	p9_proto_2000L,
30 };
31 
32 
33 /**
34  * enum p9_trans_status - different states of underlying transports
35  * @Connected: transport is connected and healthy
36  * @Disconnected: transport has been disconnected
37  * @Hung: transport is connected by wedged
38  *
39  * This enumeration details the various states a transport
40  * instatiation can be in.
41  */
42 
43 enum p9_trans_status {
44 	Connected,
45 	BeginDisconnect,
46 	Disconnected,
47 	Hung,
48 };
49 
50 /**
51  * enum p9_req_status_t - status of a request
52  * @REQ_STATUS_ALLOC: request has been allocated but not sent
53  * @REQ_STATUS_UNSENT: request waiting to be sent
54  * @REQ_STATUS_SENT: request sent to server
55  * @REQ_STATUS_RCVD: response received from server
56  * @REQ_STATUS_FLSHD: request has been flushed
57  * @REQ_STATUS_ERROR: request encountered an error on the client side
58  */
59 
60 enum p9_req_status_t {
61 	REQ_STATUS_ALLOC,
62 	REQ_STATUS_UNSENT,
63 	REQ_STATUS_SENT,
64 	REQ_STATUS_RCVD,
65 	REQ_STATUS_FLSHD,
66 	REQ_STATUS_ERROR,
67 };
68 
69 /**
70  * struct p9_req_t - request slots
71  * @status: status of this request slot
72  * @t_err: transport error
73  * @wq: wait_queue for the client to block on for this request
74  * @tc: the request fcall structure
75  * @rc: the response fcall structure
76  * @aux: transport specific data (provided for trans_fd migration)
77  * @req_list: link for higher level objects to chain requests
78  */
79 struct p9_req_t {
80 	int status;
81 	int t_err;
82 	struct kref refcount;
83 	wait_queue_head_t wq;
84 	struct p9_fcall tc;
85 	struct p9_fcall rc;
86 	void *aux;
87 	struct list_head req_list;
88 };
89 
90 /**
91  * struct p9_client - per client instance state
92  * @lock: protect @fids and @reqs
93  * @msize: maximum data size negotiated by protocol
94  * @proto_version: 9P protocol version to use
95  * @trans_mod: module API instantiated with this client
96  * @status: connection state
97  * @trans: tranport instance state and API
98  * @fids: All active FID handles
99  * @reqs: All active requests.
100  * @name: node name used as client id
101  *
102  * The client structure is used to keep track of various per-client
103  * state that has been instantiated.
104  */
105 struct p9_client {
106 	spinlock_t lock;
107 	unsigned int msize;
108 	unsigned char proto_version;
109 	struct p9_trans_module *trans_mod;
110 	enum p9_trans_status status;
111 	void *trans;
112 	struct kmem_cache *fcall_cache;
113 
114 	union {
115 		struct {
116 			int rfd;
117 			int wfd;
118 		} fd;
119 		struct {
120 			u16 port;
121 			bool privport;
122 
123 		} tcp;
124 	} trans_opts;
125 
126 	struct idr fids;
127 	struct idr reqs;
128 
129 	char name[__NEW_UTS_LEN + 1];
130 };
131 
132 /**
133  * struct p9_fid - file system entity handle
134  * @clnt: back pointer to instantiating &p9_client
135  * @fid: numeric identifier for this handle
136  * @mode: current mode of this fid (enum?)
137  * @qid: the &p9_qid server identifier this handle points to
138  * @iounit: the server reported maximum transaction size for this file
139  * @uid: the numeric uid of the local user who owns this handle
140  * @rdir: readdir accounting structure (allocated on demand)
141  * @dlist: per-dentry fid tracking
142  *
143  * TODO: This needs lots of explanation.
144  */
145 
146 struct p9_fid {
147 	struct p9_client *clnt;
148 	u32 fid;
149 	int mode;
150 	struct p9_qid qid;
151 	u32 iounit;
152 	kuid_t uid;
153 
154 	void *rdir;
155 
156 	struct hlist_node dlist;	/* list of all fids attached to a dentry */
157 };
158 
159 /**
160  * struct p9_dirent - directory entry structure
161  * @qid: The p9 server qid for this dirent
162  * @d_off: offset to the next dirent
163  * @d_type: type of file
164  * @d_name: file name
165  */
166 
167 struct p9_dirent {
168 	struct p9_qid qid;
169 	u64 d_off;
170 	unsigned char d_type;
171 	char d_name[256];
172 };
173 
174 struct iov_iter;
175 
176 int p9_show_client_options(struct seq_file *m, struct p9_client *clnt);
177 int p9_client_statfs(struct p9_fid *fid, struct p9_rstatfs *sb);
178 int p9_client_rename(struct p9_fid *fid, struct p9_fid *newdirfid,
179 		     const char *name);
180 int p9_client_renameat(struct p9_fid *olddirfid, const char *old_name,
181 		       struct p9_fid *newdirfid, const char *new_name);
182 struct p9_client *p9_client_create(const char *dev_name, char *options);
183 void p9_client_destroy(struct p9_client *clnt);
184 void p9_client_disconnect(struct p9_client *clnt);
185 void p9_client_begin_disconnect(struct p9_client *clnt);
186 struct p9_fid *p9_client_attach(struct p9_client *clnt, struct p9_fid *afid,
187 				const char *uname, kuid_t n_uname, const char *aname);
188 struct p9_fid *p9_client_walk(struct p9_fid *oldfid, uint16_t nwname,
189 		const unsigned char * const *wnames, int clone);
190 int p9_client_open(struct p9_fid *fid, int mode);
191 int p9_client_fcreate(struct p9_fid *fid, const char *name, u32 perm, int mode,
192 							char *extension);
193 int p9_client_link(struct p9_fid *fid, struct p9_fid *oldfid, const char *newname);
194 int p9_client_symlink(struct p9_fid *fid, const char *name, const char *symname,
195 		kgid_t gid, struct p9_qid *qid);
196 int p9_client_create_dotl(struct p9_fid *ofid, const char *name, u32 flags, u32 mode,
197 		kgid_t gid, struct p9_qid *qid);
198 int p9_client_clunk(struct p9_fid *fid);
199 int p9_client_fsync(struct p9_fid *fid, int datasync);
200 int p9_client_remove(struct p9_fid *fid);
201 int p9_client_unlinkat(struct p9_fid *dfid, const char *name, int flags);
202 int p9_client_read(struct p9_fid *fid, u64 offset, struct iov_iter *to, int *err);
203 int p9_client_write(struct p9_fid *fid, u64 offset, struct iov_iter *from, int *err);
204 int p9_client_readdir(struct p9_fid *fid, char *data, u32 count, u64 offset);
205 int p9dirent_read(struct p9_client *clnt, char *buf, int len,
206 		  struct p9_dirent *dirent);
207 struct p9_wstat *p9_client_stat(struct p9_fid *fid);
208 int p9_client_wstat(struct p9_fid *fid, struct p9_wstat *wst);
209 int p9_client_setattr(struct p9_fid *fid, struct p9_iattr_dotl *attr);
210 
211 struct p9_stat_dotl *p9_client_getattr_dotl(struct p9_fid *fid,
212 							u64 request_mask);
213 
214 int p9_client_mknod_dotl(struct p9_fid *oldfid, const char *name, int mode,
215 			dev_t rdev, kgid_t gid, struct p9_qid *);
216 int p9_client_mkdir_dotl(struct p9_fid *fid, const char *name, int mode,
217 				kgid_t gid, struct p9_qid *);
218 int p9_client_lock_dotl(struct p9_fid *fid, struct p9_flock *flock, u8 *status);
219 int p9_client_getlock_dotl(struct p9_fid *fid, struct p9_getlock *fl);
220 void p9_fcall_fini(struct p9_fcall *fc);
221 struct p9_req_t *p9_tag_lookup(struct p9_client *, u16);
222 
223 static inline void p9_req_get(struct p9_req_t *r)
224 {
225 	kref_get(&r->refcount);
226 }
227 
228 static inline int p9_req_try_get(struct p9_req_t *r)
229 {
230 	return kref_get_unless_zero(&r->refcount);
231 }
232 
233 int p9_req_put(struct p9_req_t *r);
234 
235 void p9_client_cb(struct p9_client *c, struct p9_req_t *req, int status);
236 
237 int p9_parse_header(struct p9_fcall *, int32_t *, int8_t *, int16_t *, int);
238 int p9stat_read(struct p9_client *, char *, int, struct p9_wstat *);
239 void p9stat_free(struct p9_wstat *);
240 
241 int p9_is_proto_dotu(struct p9_client *clnt);
242 int p9_is_proto_dotl(struct p9_client *clnt);
243 struct p9_fid *p9_client_xattrwalk(struct p9_fid *, const char *, u64 *);
244 int p9_client_xattrcreate(struct p9_fid *, const char *, u64, int);
245 int p9_client_readlink(struct p9_fid *fid, char **target);
246 
247 int p9_client_init(void);
248 void p9_client_exit(void);
249 
250 #endif /* NET_9P_CLIENT_H */
251