LXR linux/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
  26enum 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
  43enum 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
  60enum 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 */
  78struct 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 */
 103struct 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 */
 143enum fid_source {
 144        FID_FROM_OTHER,
 145        FID_FROM_INODE,
 146        FID_FROM_DENTRY,
 147};
 148
 149struct p9_fid {
 150        struct p9_client *clnt;
 151        u32 fid;
 152        refcount_t count;
 153        int mode;
 154        struct p9_qid qid;
 155        u32 iounit;
 156        kuid_t uid;
 157
 158        void *rdir;
 159
 160        struct hlist_node dlist;        /* list of all fids attached to a dentry */
 161        struct hlist_node ilist;
 162};
 163
 164/**
 165 * struct p9_dirent - directory entry structure
 166 * @qid: The p9 server qid for this dirent
 167 * @d_off: offset to the next dirent
 168 * @d_type: type of file
 169 * @d_name: file name
 170 */
 171
 172struct p9_dirent {
 173        struct p9_qid qid;
 174        u64 d_off;
 175        unsigned char d_type;
 176        char d_name[256];
 177};
 178
 179struct iov_iter;
 180
 181int p9_show_client_options(struct seq_file *m, struct p9_client *clnt);
 182int p9_client_statfs(struct p9_fid *fid, struct p9_rstatfs *sb);
 183int p9_client_rename(struct p9_fid *fid, struct p9_fid *newdirfid,
 184                     const char *name);
 185int p9_client_renameat(struct p9_fid *olddirfid, const char *old_name,
 186                       struct p9_fid *newdirfid, const char *new_name);
 187struct p9_client *p9_client_create(const char *dev_name, char *options);
 188void p9_client_destroy(struct p9_client *clnt);
 189void p9_client_disconnect(struct p9_client *clnt);
 190void p9_client_begin_disconnect(struct p9_client *clnt);
 191struct p9_fid *p9_client_attach(struct p9_client *clnt, struct p9_fid *afid,
 192                                const char *uname, kuid_t n_uname, const char *aname);
 193struct p9_fid *p9_client_walk(struct p9_fid *oldfid, uint16_t nwname,
 194                const unsigned char * const *wnames, int clone);
 195int p9_client_open(struct p9_fid *fid, int mode);
 196int p9_client_fcreate(struct p9_fid *fid, const char *name, u32 perm, int mode,
 197                                                        char *extension);
 198int p9_client_link(struct p9_fid *fid, struct p9_fid *oldfid, const char *newname);
 199int p9_client_symlink(struct p9_fid *fid, const char *name, const char *symname,
 200                kgid_t gid, struct p9_qid *qid);
 201int p9_client_create_dotl(struct p9_fid *ofid, const char *name, u32 flags, u32 mode,
 202                kgid_t gid, struct p9_qid *qid);
 203int p9_client_clunk(struct p9_fid *fid);
 204int p9_client_fsync(struct p9_fid *fid, int datasync);
 205int p9_client_remove(struct p9_fid *fid);
 206int p9_client_unlinkat(struct p9_fid *dfid, const char *name, int flags);
 207int p9_client_read(struct p9_fid *fid, u64 offset, struct iov_iter *to, int *err);
 208int p9_client_read_once(struct p9_fid *fid, u64 offset, struct iov_iter *to,
 209                int *err);
 210int p9_client_write(struct p9_fid *fid, u64 offset, struct iov_iter *from, int *err);
 211int p9_client_readdir(struct p9_fid *fid, char *data, u32 count, u64 offset);
 212int p9dirent_read(struct p9_client *clnt, char *buf, int len,
 213                  struct p9_dirent *dirent);
 214struct p9_wstat *p9_client_stat(struct p9_fid *fid);
 215int p9_client_wstat(struct p9_fid *fid, struct p9_wstat *wst);
 216int p9_client_setattr(struct p9_fid *fid, struct p9_iattr_dotl *attr);
 217
 218struct p9_stat_dotl *p9_client_getattr_dotl(struct p9_fid *fid,
 219                                                        u64 request_mask);
 220
 221int p9_client_mknod_dotl(struct p9_fid *oldfid, const char *name, int mode,
 222                        dev_t rdev, kgid_t gid, struct p9_qid *);
 223int p9_client_mkdir_dotl(struct p9_fid *fid, const char *name, int mode,
 224                                kgid_t gid, struct p9_qid *);
 225int p9_client_lock_dotl(struct p9_fid *fid, struct p9_flock *flock, u8 *status);
 226int p9_client_getlock_dotl(struct p9_fid *fid, struct p9_getlock *fl);
 227void p9_fcall_fini(struct p9_fcall *fc);
 228struct p9_req_t *p9_tag_lookup(struct p9_client *, u16);
 229
 230static inline void p9_req_get(struct p9_req_t *r)
 231{
 232        kref_get(&r->refcount);
 233}
 234
 235static inline int p9_req_try_get(struct p9_req_t *r)
 236{
 237        return kref_get_unless_zero(&r->refcount);
 238}
 239
 240int p9_req_put(struct p9_req_t *r);
 241
 242void p9_client_cb(struct p9_client *c, struct p9_req_t *req, int status);
 243
 244int p9_parse_header(struct p9_fcall *, int32_t *, int8_t *, int16_t *, int);
 245int p9stat_read(struct p9_client *, char *, int, struct p9_wstat *);
 246void p9stat_free(struct p9_wstat *);
 247
 248int p9_is_proto_dotu(struct p9_client *clnt);
 249int p9_is_proto_dotl(struct p9_client *clnt);
 250struct p9_fid *p9_client_xattrwalk(struct p9_fid *, const char *, u64 *);
 251int p9_client_xattrcreate(struct p9_fid *, const char *, u64, int);
 252int p9_client_readlink(struct p9_fid *fid, char **target);
 253
 254int p9_client_init(void);
 255void p9_client_exit(void);
 256
 257#endif /* NET_9P_CLIENT_H */
 258