include/net/9p/client.h

   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 */