include/net/9p/client.h

   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  * @req_list: link for higher level objects to chain requests
  77  */
  78 struct p9_req_t {
  79         int status;
  80         int t_err;
  81         struct kref refcount;
  82         wait_queue_head_t wq;
  83         struct p9_fcall tc;
  84         struct p9_fcall rc;
  85         struct list_head req_list;
  86 };
  87
  88 /**
  89  * struct p9_client - per client instance state
  90  * @lock: protect @fids and @reqs
  91  * @msize: maximum data size negotiated by protocol
  92  * @proto_version: 9P protocol version to use
  93  * @trans_mod: module API instantiated with this client
  94  * @status: connection state
  95  * @trans: tranport instance state and API
  96  * @fids: All active FID handles
  97  * @reqs: All active requests.
  98  * @name: node name used as client id
  99  *
 100  * The client structure is used to keep track of various per-client
 101  * state that has been instantiated.
 102  */
 103 struct p9_client {
 104         spinlock_t lock;
 105         unsigned int msize;
 106         unsigned char proto_version;
 107         struct p9_trans_module *trans_mod;
 108         enum p9_trans_status status;
 109         void *trans;
 110         struct kmem_cache *fcall_cache;
 111
 112         union {
 113                 struct {
 114                         int rfd;
 115                         int wfd;
 116                 } fd;
 117                 struct {
 118                         u16 port;
 119                         bool privport;
 120
 121                 } tcp;
 122         } trans_opts;
 123
 124         struct idr fids;
 125         struct idr reqs;
 126
 127         char name[__NEW_UTS_LEN + 1];
 128 };
 129
 130 /**
 131  * struct p9_fid - file system entity handle
 132  * @clnt: back pointer to instantiating &p9_client
 133  * @fid: numeric identifier for this handle
 134  * @mode: current mode of this fid (enum?)
 135  * @qid: the &p9_qid server identifier this handle points to
 136  * @iounit: the server reported maximum transaction size for this file
 137  * @uid: the numeric uid of the local user who owns this handle
 138  * @rdir: readdir accounting structure (allocated on demand)
 139  * @dlist: per-dentry fid tracking
 140  *
 141  * TODO: This needs lots of explanation.
 142  */
 143
 144 struct p9_fid {
 145         struct p9_client *clnt;
 146         u32 fid;
 147         int mode;
 148         struct p9_qid qid;
 149         u32 iounit;
 150         kuid_t uid;
 151
 152         void *rdir;
 153
 154         struct hlist_node dlist;        /* list of all fids attached to a dentry */
 155 };
 156
 157 /**
 158  * struct p9_dirent - directory entry structure
 159  * @qid: The p9 server qid for this dirent
 160  * @d_off: offset to the next dirent
 161  * @d_type: type of file
 162  * @d_name: file name
 163  */
 164
 165 struct p9_dirent {
 166         struct p9_qid qid;
 167         u64 d_off;
 168         unsigned char d_type;
 169         char d_name[256];
 170 };
 171
 172 struct iov_iter;
 173
 174 int p9_show_client_options(struct seq_file *m, struct p9_client *clnt);
 175 int p9_client_statfs(struct p9_fid *fid, struct p9_rstatfs *sb);
 176 int p9_client_rename(struct p9_fid *fid, struct p9_fid *newdirfid,
 177                      const char *name);
 178 int p9_client_renameat(struct p9_fid *olddirfid, const char *old_name,
 179                        struct p9_fid *newdirfid, const char *new_name);
 180 struct p9_client *p9_client_create(const char *dev_name, char *options);
 181 void p9_client_destroy(struct p9_client *clnt);
 182 void p9_client_disconnect(struct p9_client *clnt);
 183 void p9_client_begin_disconnect(struct p9_client *clnt);
 184 struct p9_fid *p9_client_attach(struct p9_client *clnt, struct p9_fid *afid,
 185                                 const char *uname, kuid_t n_uname, const char *aname);
 186 struct p9_fid *p9_client_walk(struct p9_fid *oldfid, uint16_t nwname,
 187                 const unsigned char * const *wnames, int clone);
 188 int p9_client_open(struct p9_fid *fid, int mode);
 189 int p9_client_fcreate(struct p9_fid *fid, const char *name, u32 perm, int mode,
 190                                                         char *extension);
 191 int p9_client_link(struct p9_fid *fid, struct p9_fid *oldfid, const char *newname);
 192 int p9_client_symlink(struct p9_fid *fid, const char *name, const char *symname,
 193                 kgid_t gid, struct p9_qid *qid);
 194 int p9_client_create_dotl(struct p9_fid *ofid, const char *name, u32 flags, u32 mode,
 195                 kgid_t gid, struct p9_qid *qid);
 196 int p9_client_clunk(struct p9_fid *fid);
 197 int p9_client_fsync(struct p9_fid *fid, int datasync);
 198 int p9_client_remove(struct p9_fid *fid);
 199 int p9_client_unlinkat(struct p9_fid *dfid, const char *name, int flags);
 200 int p9_client_read(struct p9_fid *fid, u64 offset, struct iov_iter *to, int *err);
 201 int p9_client_read_once(struct p9_fid *fid, u64 offset, struct iov_iter *to,
 202                 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 */