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
  42 /**
  43  * struct iscsi_transport - iSCSI Transport template
  44  *
  45  * @name:               transport name
  46  * @caps:               iSCSI Data-Path capabilities
  47  * @create_session:     create new iSCSI session object
  48  * @destroy_session:    destroy existing iSCSI session object
  49  * @create_conn:        create new iSCSI connection
  50  * @bind_conn:          associate this connection with existing iSCSI session
  51  *                      and specified transport descriptor
  52  * @destroy_conn:       destroy inactive iSCSI connection
  53  * @set_param:          set iSCSI parameter. Return 0 on success, -ENODATA
  54  *                      when param is not supported, and a -Exx value on other
  55  *                      error.
  56  * @get_param           get iSCSI parameter. Must return number of bytes
  57  *                      copied to buffer on success, -ENODATA when param
  58  *                      is not supported, and a -Exx value on other error
  59  * @start_conn:         set connection to be operational
  60  * @stop_conn:          suspend/recover/terminate connection
  61  * @send_pdu:           send iSCSI PDU, Login, Logout, NOP-Out, Reject, Text.
  62  * @session_recovery_timedout: notify LLD a block during recovery timed out
  63  * @init_task:          Initialize a iscsi_task and any internal structs.
  64  *                      When offloading the data path, this is called from
  65  *                      queuecommand with the session lock, or from the
  66  *                      iscsi_conn_send_pdu context with the session lock.
  67  *                      When not offloading the data path, this is called
  68  *                      from the scsi work queue without the session lock.
  69  * @xmit_task           Requests LLD to transfer cmd task. Returns 0 or the
  70  *                      the number of bytes transferred on success, and -Exyz
  71  *                      value on error. When offloading the data path, this
  72  *                      is called from queuecommand with the session lock, or
  73  *                      from the iscsi_conn_send_pdu context with the session
  74  *                      lock. When not offloading the data path, this is called
  75  *                      from the scsi work queue without the session lock.
  76  * @cleanup_task:       requests LLD to fail task. Called with session lock
  77  *                      and after the connection has been suspended and
  78  *                      terminated during recovery. If called
  79  *                      from abort task then connection is not suspended
  80  *                      or terminated but sk_callback_lock is held
  81  *
  82  * Template API provided by iSCSI Transport
  83  */
  84 struct iscsi_transport {
  85         struct module *owner;
  86         char *name;
  87         unsigned int caps;
  88
  89         struct iscsi_cls_session *(*create_session) (struct iscsi_endpoint *ep,
  90                                         uint16_t cmds_max, uint16_t qdepth,
  91                                         uint32_t sn);
  92         void (*destroy_session) (struct iscsi_cls_session *session);
  93         struct iscsi_cls_conn *(*create_conn) (struct iscsi_cls_session *sess,
  94                                 uint32_t cid);
  95         int (*bind_conn) (struct iscsi_cls_session *session,
  96                           struct iscsi_cls_conn *cls_conn,
  97                           uint64_t transport_eph, int is_leading);
  98         int (*start_conn) (struct iscsi_cls_conn *conn);
  99         void (*stop_conn) (struct iscsi_cls_conn *conn, int flag);
 100         void (*destroy_conn) (struct iscsi_cls_conn *conn);
 101         int (*set_param) (struct iscsi_cls_conn *conn, enum iscsi_param param,
 102                           char *buf, int buflen);
 103         int (*get_ep_param) (struct iscsi_endpoint *ep, enum iscsi_param param,
 104                              char *buf);
 105         int (*get_conn_param) (struct iscsi_cls_conn *conn,
 106                                enum iscsi_param param, char *buf);
 107         int (*get_session_param) (struct iscsi_cls_session *session,
 108                                   enum iscsi_param param, char *buf);
 109         int (*get_host_param) (struct Scsi_Host *shost,
 110                                 enum iscsi_host_param param, char *buf);
 111         int (*set_host_param) (struct Scsi_Host *shost,
 112                                enum iscsi_host_param param, char *buf,
 113                                int buflen);
 114         int (*send_pdu) (struct iscsi_cls_conn *conn, struct iscsi_hdr *hdr,
 115                          char *data, uint32_t data_size);
 116         void (*get_stats) (struct iscsi_cls_conn *conn,
 117                            struct iscsi_stats *stats);
 118
 119         int (*init_task) (struct iscsi_task *task);
 120         int (*xmit_task) (struct iscsi_task *task);
 121         void (*cleanup_task) (struct iscsi_task *task);
 122
 123         int (*alloc_pdu) (struct iscsi_task *task, uint8_t opcode);
 124         int (*xmit_pdu) (struct iscsi_task *task);
 125         int (*init_pdu) (struct iscsi_task *task, unsigned int offset,
 126                          unsigned int count);
 127         void (*parse_pdu_itt) (struct iscsi_conn *conn, itt_t itt,
 128                                int *index, int *age);
 129
 130         void (*session_recovery_timedout) (struct iscsi_cls_session *session);
 131         struct iscsi_endpoint *(*ep_connect) (struct Scsi_Host *shost,
 132                                               struct sockaddr *dst_addr,
 133                                               int non_blocking);
 134         int (*ep_poll) (struct iscsi_endpoint *ep, int timeout_ms);
 135         void (*ep_disconnect) (struct iscsi_endpoint *ep);
 136         int (*tgt_dscvr) (struct Scsi_Host *shost, enum iscsi_tgt_dscvr type,
 137                           uint32_t enable, struct sockaddr *dst_addr);
 138         int (*set_path) (struct Scsi_Host *shost, struct iscsi_path *params);
 139         int (*set_iface_param) (struct Scsi_Host *shost, char *data, int count);
 140         int (*get_iface_param) (struct iscsi_iface *iface,
 141                                 enum iscsi_param_type param_type,
 142                                 int param, char *buf);
 143         mode_t (*attr_is_visible)(int param_type, int param);
 144 };
 145
 146
 147 /*
 148  * transport registration upcalls
 149  */
 150 extern struct scsi_transport_template *iscsi_register_transport(struct iscsi_transport *tt);
 151 extern int iscsi_unregister_transport(struct iscsi_transport *tt);
 152
 153 /*
 154  * control plane upcalls
 155  */
 156 extern void iscsi_conn_error_event(struct iscsi_cls_conn *conn,
 157                                    enum iscsi_err error);
 158 extern int iscsi_recv_pdu(struct iscsi_cls_conn *conn, struct iscsi_hdr *hdr,
 159                           char *data, uint32_t data_size);
 160
 161 extern int iscsi_offload_mesg(struct Scsi_Host *shost,
 162                               struct iscsi_transport *transport, uint32_t type,
 163                               char *data, uint16_t data_size);
 164
 165 struct iscsi_cls_conn {
 166         struct list_head conn_list;     /* item in connlist */
 167         void *dd_data;                  /* LLD private data */
 168         struct iscsi_transport *transport;
 169         uint32_t cid;                   /* connection id */
 170         struct mutex ep_mutex;
 171         struct iscsi_endpoint *ep;
 172
 173         struct device dev;              /* sysfs transport/container device */
 174 };
 175
 176 #define iscsi_dev_to_conn(_dev) \
 177         container_of(_dev, struct iscsi_cls_conn, dev)
 178
 179 #define transport_class_to_conn(_cdev) \
 180         iscsi_dev_to_conn(_cdev->parent)
 181
 182 #define iscsi_conn_to_session(_conn) \
 183         iscsi_dev_to_session(_conn->dev.parent)
 184
 185 /* iscsi class session state */
 186 enum {
 187         ISCSI_SESSION_LOGGED_IN,
 188         ISCSI_SESSION_FAILED,
 189         ISCSI_SESSION_FREE,
 190 };
 191
 192 #define ISCSI_MAX_TARGET -1
 193
 194 struct iscsi_cls_session {
 195         struct list_head sess_list;             /* item in session_list */
 196         struct iscsi_transport *transport;
 197         spinlock_t lock;
 198         struct work_struct block_work;
 199         struct work_struct unblock_work;
 200         struct work_struct scan_work;
 201         struct work_struct unbind_work;
 202
 203         /* recovery fields */
 204         int recovery_tmo;
 205         struct delayed_work recovery_work;
 206
 207         unsigned int target_id;
 208
 209         int state;
 210         int sid;                                /* session id */
 211         void *dd_data;                          /* LLD private data */
 212         struct device dev;      /* sysfs transport/container device */
 213 };
 214
 215 #define iscsi_dev_to_session(_dev) \
 216         container_of(_dev, struct iscsi_cls_session, dev)
 217
 218 #define transport_class_to_session(_cdev) \
 219         iscsi_dev_to_session(_cdev->parent)
 220
 221 #define iscsi_session_to_shost(_session) \
 222         dev_to_shost(_session->dev.parent)
 223
 224 #define starget_to_session(_stgt) \
 225         iscsi_dev_to_session(_stgt->dev.parent)
 226
 227 struct iscsi_cls_host {
 228         atomic_t nr_scans;
 229         struct mutex mutex;
 230 };
 231
 232 extern void iscsi_host_for_each_session(struct Scsi_Host *shost,
 233                                 void (*fn)(struct iscsi_cls_session *));
 234
 235 struct iscsi_endpoint {
 236         void *dd_data;                  /* LLD private data */
 237         struct device dev;
 238         uint64_t id;
 239         struct iscsi_cls_conn *conn;
 240 };
 241
 242 struct iscsi_iface {
 243         struct device dev;
 244         struct iscsi_transport *transport;
 245         uint32_t iface_type;    /* IPv4 or IPv6 */
 246         uint32_t iface_num;     /* iface number, 0 - n */
 247         void *dd_data;          /* LLD private data */
 248 };
 249
 250 #define iscsi_dev_to_iface(_dev) \
 251         container_of(_dev, struct iscsi_iface, dev)
 252
 253 #define iscsi_iface_to_shost(_iface) \
 254         dev_to_shost(_iface->dev.parent)
 255
 256 /*
 257  * session and connection functions that can be used by HW iSCSI LLDs
 258  */
 259 #define iscsi_cls_session_printk(prefix, _cls_session, fmt, a...) \
 260         dev_printk(prefix, &(_cls_session)->dev, fmt, ##a)
 261
 262 #define iscsi_cls_conn_printk(prefix, _cls_conn, fmt, a...) \
 263         dev_printk(prefix, &(_cls_conn)->dev, fmt, ##a)
 264
 265 extern int iscsi_session_chkready(struct iscsi_cls_session *session);
 266 extern struct iscsi_cls_session *iscsi_alloc_session(struct Scsi_Host *shost,
 267                                 struct iscsi_transport *transport, int dd_size);
 268 extern int iscsi_add_session(struct iscsi_cls_session *session,
 269                              unsigned int target_id);
 270 extern int iscsi_session_event(struct iscsi_cls_session *session,
 271                                enum iscsi_uevent_e event);
 272 extern struct iscsi_cls_session *iscsi_create_session(struct Scsi_Host *shost,
 273                                                 struct iscsi_transport *t,
 274                                                 int dd_size,
 275                                                 unsigned int target_id);
 276 extern void iscsi_remove_session(struct iscsi_cls_session *session);
 277 extern void iscsi_free_session(struct iscsi_cls_session *session);
 278 extern int iscsi_destroy_session(struct iscsi_cls_session *session);
 279 extern struct iscsi_cls_conn *iscsi_create_conn(struct iscsi_cls_session *sess,
 280                                                 int dd_size, uint32_t cid);
 281 extern int iscsi_destroy_conn(struct iscsi_cls_conn *conn);
 282 extern void iscsi_unblock_session(struct iscsi_cls_session *session);
 283 extern void iscsi_block_session(struct iscsi_cls_session *session);
 284 extern int iscsi_scan_finished(struct Scsi_Host *shost, unsigned long time);
 285 extern struct iscsi_endpoint *iscsi_create_endpoint(int dd_size);
 286 extern void iscsi_destroy_endpoint(struct iscsi_endpoint *ep);
 287 extern struct iscsi_endpoint *iscsi_lookup_endpoint(u64 handle);
 288 extern int iscsi_block_scsi_eh(struct scsi_cmnd *cmd);
 289 extern struct iscsi_iface *iscsi_create_iface(struct Scsi_Host *shost,
 290                                               struct iscsi_transport *t,
 291                                               uint32_t iface_type,
 292                                               uint32_t iface_num, int dd_size);
 293 extern void iscsi_destroy_iface(struct iscsi_iface *iface);
 294 extern struct iscsi_iface *iscsi_lookup_iface(int handle);
 295
 296 #endif