include/scsi/scsi_transport_iscsi.h

   1 /*
   2  * iSCSI transport class definitions
   3  *
   4  * Copyright (C) IBM Corporation, 2004
   5  * Copyright (C) Mike Christie, 2004 - 2006
   6  * Copyright (C) Dmitry Yusupov, 2004 - 2005
   7  * Copyright (C) Alex Aizman, 2004 - 2005
   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 as published by
  11  * the Free Software Foundation; either version 2 of the License, or
  12  * (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  * GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program; if not, write to the Free Software
  21  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  22  */
  23 #ifndef SCSI_TRANSPORT_ISCSI_H
  24 #define SCSI_TRANSPORT_ISCSI_H
  25
  26 #include <linux/device.h>
  27 #include <linux/list.h>
  28 #include <linux/mutex.h>
  29 #include <scsi/iscsi_if.h>
  30
  31 struct scsi_transport_template;
  32 struct iscsi_transport;
  33 struct iscsi_endpoint;
  34 struct Scsi_Host;
  35 struct scsi_cmnd;
  36 struct iscsi_cls_conn;
  37 struct iscsi_conn;
  38 struct iscsi_task;
  39 struct sockaddr;
  40 struct iscsi_iface;
  41 struct bsg_job;
  42
  43 /**
  44  * struct iscsi_transport - iSCSI Transport template
  45  *
  46  * @name:               transport name
  47  * @caps:               iSCSI Data-Path capabilities
  48  * @create_session:     create new iSCSI session object
  49  * @destroy_session:    destroy existing iSCSI session object
  50  * @create_conn:        create new iSCSI connection
  51  * @bind_conn:          associate this connection with existing iSCSI session
  52  *                      and specified transport descriptor
  53  * @destroy_conn:       destroy inactive iSCSI connection
  54  * @set_param:          set iSCSI parameter. Return 0 on success, -ENODATA
  55  *                      when param is not supported, and a -Exx value on other
  56  *                      error.
  57  * @get_param           get iSCSI parameter. Must return number of bytes
  58  *                      copied to buffer on success, -ENODATA when param
  59  *                      is not supported, and a -Exx value on other error
  60  * @start_conn:         set connection to be operational
  61  * @stop_conn:          suspend/recover/terminate connection
  62  * @send_pdu:           send iSCSI PDU, Login, Logout, NOP-Out, Reject, Text.
  63  * @session_recovery_timedout: notify LLD a block during recovery timed out
  64  * @init_task:          Initialize a iscsi_task and any internal structs.
  65  *                      When offloading the data path, this is called from
  66  *                      queuecommand with the session lock, or from the
  67  *                      iscsi_conn_send_pdu context with the session lock.
  68  *                      When not offloading the data path, this is called
  69  *                      from the scsi work queue without the session lock.
  70  * @xmit_task           Requests LLD to transfer cmd task. Returns 0 or the
  71  *                      the number of bytes transferred on success, and -Exyz
  72  *                      value on error. When offloading the data path, this
  73  *                      is called from queuecommand with the session lock, or
  74  *                      from the iscsi_conn_send_pdu context with the session
  75  *                      lock. When not offloading the data path, this is called
  76  *                      from the scsi work queue without the session lock.
  77  * @cleanup_task:       requests LLD to fail task. Called with session lock
  78  *                      and after the connection has been suspended and
  79  *                      terminated during recovery. If called
  80  *                      from abort task then connection is not suspended
  81  *                      or terminated but sk_callback_lock is held
  82  *
  83  * Template API provided by iSCSI Transport
  84  */
  85 struct iscsi_transport {
  86         struct module *owner;
  87         char *name;
  88         unsigned int caps;
  89
  90         struct iscsi_cls_session *(*create_session) (struct iscsi_endpoint *ep,
  91                                         uint16_t cmds_max, uint16_t qdepth,
  92                                         uint32_t sn);
  93         void (*destroy_session) (struct iscsi_cls_session *session);
  94         struct iscsi_cls_conn *(*create_conn) (struct iscsi_cls_session *sess,
  95                                 uint32_t cid);
  96         int (*bind_conn) (struct iscsi_cls_session *session,
  97                           struct iscsi_cls_conn *cls_conn,
  98                           uint64_t transport_eph, int is_leading);
  99         int (*start_conn) (struct iscsi_cls_conn *conn);
 100         void (*stop_conn) (struct iscsi_cls_conn *conn, int flag);
 101         void (*destroy_conn) (struct iscsi_cls_conn *conn);
 102         int (*set_param) (struct iscsi_cls_conn *conn, enum iscsi_param param,
 103                           char *buf, int buflen);
 104         int (*get_ep_param) (struct iscsi_endpoint *ep, enum iscsi_param param,
 105                              char *buf);
 106         int (*get_conn_param) (struct iscsi_cls_conn *conn,
 107                                enum iscsi_param param, char *buf);
 108         int (*get_session_param) (struct iscsi_cls_session *session,
 109                                   enum iscsi_param param, char *buf);
 110         int (*get_host_param) (struct Scsi_Host *shost,
 111                                 enum iscsi_host_param param, char *buf);
 112         int (*set_host_param) (struct Scsi_Host *shost,
 113                                enum iscsi_host_param param, char *buf,
 114                                int buflen);
 115         int (*send_pdu) (struct iscsi_cls_conn *conn, struct iscsi_hdr *hdr,
 116                          char *data, uint32_t data_size);
 117         void (*get_stats) (struct iscsi_cls_conn *conn,
 118                            struct iscsi_stats *stats);
 119
 120         int (*init_task) (struct iscsi_task *task);
 121         int (*xmit_task) (struct iscsi_task *task);
 122         void (*cleanup_task) (struct iscsi_task *task);
 123
 124         int (*alloc_pdu) (struct iscsi_task *task, uint8_t opcode);
 125         int (*xmit_pdu) (struct iscsi_task *task);
 126         int (*init_pdu) (struct iscsi_task *task, unsigned int offset,
 127                          unsigned int count);
 128         void (*parse_pdu_itt) (struct iscsi_conn *conn, itt_t itt,
 129                                int *index, int *age);
 130
 131         void (*session_recovery_timedout) (struct iscsi_cls_session *session);
 132         struct iscsi_endpoint *(*ep_connect) (struct Scsi_Host *shost,
 133                                               struct sockaddr *dst_addr,
 134                                               int non_blocking);
 135         int (*ep_poll) (struct iscsi_endpoint *ep, int timeout_ms);
 136         void (*ep_disconnect) (struct iscsi_endpoint *ep);
 137         int (*tgt_dscvr) (struct Scsi_Host *shost, enum iscsi_tgt_dscvr type,
 138                           uint32_t enable, struct sockaddr *dst_addr);
 139         int (*set_path) (struct Scsi_Host *shost, struct iscsi_path *params);
 140         int (*set_iface_param) (struct Scsi_Host *shost, void *data,
 141                                 uint32_t len);
 142         int (*get_iface_param) (struct iscsi_iface *iface,
 143                                 enum iscsi_param_type param_type,
 144                                 int param, char *buf);
 145         umode_t (*attr_is_visible)(int param_type, int param);
 146         int (*bsg_request)(struct bsg_job *job);
 147 };
 148
 149 /*
 150  * transport registration upcalls
 151  */
 152 extern struct scsi_transport_template *iscsi_register_transport(struct iscsi_transport *tt);
 153 extern int iscsi_unregister_transport(struct iscsi_transport *tt);
 154
 155 /*
 156  * control plane upcalls
 157  */
 158 extern void iscsi_conn_error_event(struct iscsi_cls_conn *conn,
 159                                    enum iscsi_err error);
 160 extern void iscsi_conn_login_event(struct iscsi_cls_conn *conn,
 161                                    enum iscsi_conn_state state);
 162 extern int iscsi_recv_pdu(struct iscsi_cls_conn *conn, struct iscsi_hdr *hdr,
 163                           char *data, uint32_t data_size);
 164
 165 extern int iscsi_offload_mesg(struct Scsi_Host *shost,
 166                               struct iscsi_transport *transport, uint32_t type,
 167                               char *data, uint16_t data_size);
 168
 169 struct iscsi_cls_conn {
 170         struct list_head conn_list;     /* item in connlist */
 171         void *dd_data;                  /* LLD private data */
 172         struct iscsi_transport *transport;
 173         uint32_t cid;                   /* connection id */
 174         struct mutex ep_mutex;
 175         struct iscsi_endpoint *ep;
 176
 177         struct device dev;              /* sysfs transport/container device */
 178 };
 179
 180 #define iscsi_dev_to_conn(_dev) \
 181         container_of(_dev, struct iscsi_cls_conn, dev)
 182
 183 #define transport_class_to_conn(_cdev) \
 184         iscsi_dev_to_conn(_cdev->parent)
 185
 186 #define iscsi_conn_to_session(_conn) \
 187         iscsi_dev_to_session(_conn->dev.parent)
 188
 189 /* iscsi class session state */
 190 enum {
 191         ISCSI_SESSION_LOGGED_IN,
 192         ISCSI_SESSION_FAILED,
 193         ISCSI_SESSION_FREE,
 194 };
 195
 196 #define ISCSI_MAX_TARGET -1
 197
 198 struct iscsi_cls_session {
 199         struct list_head sess_list;             /* item in session_list */
 200         struct iscsi_transport *transport;
 201         spinlock_t lock;
 202         struct work_struct block_work;
 203         struct work_struct unblock_work;
 204         struct work_struct scan_work;
 205         struct work_struct unbind_work;
 206
 207         /* recovery fields */
 208         int recovery_tmo;
 209         struct delayed_work recovery_work;
 210
 211         unsigned int target_id;
 212         bool ida_used;
 213
 214         /*
 215          * pid of userspace process that created session or -1 if
 216          * created by the kernel.
 217          */
 218         pid_t creator;
 219         int state;
 220         int sid;                                /* session id */
 221         void *dd_data;                          /* LLD private data */
 222         struct device dev;      /* sysfs transport/container device */
 223 };
 224
 225 #define iscsi_dev_to_session(_dev) \
 226         container_of(_dev, struct iscsi_cls_session, dev)
 227
 228 #define transport_class_to_session(_cdev) \
 229         iscsi_dev_to_session(_cdev->parent)
 230
 231 #define iscsi_session_to_shost(_session) \
 232         dev_to_shost(_session->dev.parent)
 233
 234 #define starget_to_session(_stgt) \
 235         iscsi_dev_to_session(_stgt->dev.parent)
 236
 237 struct iscsi_cls_host {
 238         atomic_t nr_scans;
 239         struct mutex mutex;
 240         struct request_queue *bsg_q;
 241 };
 242
 243 #define iscsi_job_to_shost(_job) \
 244         dev_to_shost(_job->dev)
 245
 246 extern void iscsi_host_for_each_session(struct Scsi_Host *shost,
 247                                 void (*fn)(struct iscsi_cls_session *));
 248
 249 struct iscsi_endpoint {
 250         void *dd_data;                  /* LLD private data */
 251         struct device dev;
 252         uint64_t id;
 253         struct iscsi_cls_conn *conn;
 254 };
 255
 256 struct iscsi_iface {
 257         struct device dev;
 258         struct iscsi_transport *transport;
 259         uint32_t iface_type;    /* IPv4 or IPv6 */
 260         uint32_t iface_num;     /* iface number, 0 - n */
 261         void *dd_data;          /* LLD private data */
 262 };
 263
 264 #define iscsi_dev_to_iface(_dev) \
 265         container_of(_dev, struct iscsi_iface, dev)
 266
 267 #define iscsi_iface_to_shost(_iface) \
 268         dev_to_shost(_iface->dev.parent)
 269
 270 /*
 271  * session and connection functions that can be used by HW iSCSI LLDs
 272  */
 273 #define iscsi_cls_session_printk(prefix, _cls_session, fmt, a...) \
 274         dev_printk(prefix, &(_cls_session)->dev, fmt, ##a)
 275
 276 #define iscsi_cls_conn_printk(prefix, _cls_conn, fmt, a...) \
 277         dev_printk(prefix, &(_cls_conn)->dev, fmt, ##a)
 278
 279 extern int iscsi_session_chkready(struct iscsi_cls_session *session);
 280 extern int iscsi_is_session_online(struct iscsi_cls_session *session);
 281 extern struct iscsi_cls_session *iscsi_alloc_session(struct Scsi_Host *shost,
 282                                 struct iscsi_transport *transport, int dd_size);
 283 extern int iscsi_add_session(struct iscsi_cls_session *session,
 284                              unsigned int target_id);
 285 extern int iscsi_session_event(struct iscsi_cls_session *session,
 286                                enum iscsi_uevent_e event);
 287 extern struct iscsi_cls_session *iscsi_create_session(struct Scsi_Host *shost,
 288                                                 struct iscsi_transport *t,
 289                                                 int dd_size,
 290                                                 unsigned int target_id);
 291 extern void iscsi_remove_session(struct iscsi_cls_session *session);
 292 extern void iscsi_free_session(struct iscsi_cls_session *session);
 293 extern int iscsi_destroy_session(struct iscsi_cls_session *session);
 294 extern struct iscsi_cls_conn *iscsi_create_conn(struct iscsi_cls_session *sess,
 295                                                 int dd_size, uint32_t cid);
 296 extern int iscsi_destroy_conn(struct iscsi_cls_conn *conn);
 297 extern void iscsi_unblock_session(struct iscsi_cls_session *session);
 298 extern void iscsi_block_session(struct iscsi_cls_session *session);
 299 extern int iscsi_scan_finished(struct Scsi_Host *shost, unsigned long time);
 300 extern struct iscsi_endpoint *iscsi_create_endpoint(int dd_size);
 301 extern void iscsi_destroy_endpoint(struct iscsi_endpoint *ep);
 302 extern struct iscsi_endpoint *iscsi_lookup_endpoint(u64 handle);
 303 extern int iscsi_block_scsi_eh(struct scsi_cmnd *cmd);
 304 extern struct iscsi_iface *iscsi_create_iface(struct Scsi_Host *shost,
 305                                               struct iscsi_transport *t,
 306                                               uint32_t iface_type,
 307                                               uint32_t iface_num, int dd_size);
 308 extern void iscsi_destroy_iface(struct iscsi_iface *iface);
 309 extern struct iscsi_iface *iscsi_lookup_iface(int handle);
 310
 311 #endif