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 <scsi/iscsi_if.h>
  28
  29 struct scsi_transport_template;
  30 struct iscsi_transport;
  31 struct Scsi_Host;
  32 struct mempool_zone;
  33 struct iscsi_cls_conn;
  34 struct iscsi_conn;
  35 struct iscsi_cmd_task;
  36 struct iscsi_mgmt_task;
  37 struct sockaddr;
  38
  39 /**
  40  * struct iscsi_transport - iSCSI Transport template
  41  *
  42  * @name:               transport name
  43  * @caps:               iSCSI Data-Path capabilities
  44  * @create_session:     create new iSCSI session object
  45  * @destroy_session:    destroy existing iSCSI session object
  46  * @create_conn:        create new iSCSI connection
  47  * @bind_conn:          associate this connection with existing iSCSI session
  48  *                      and specified transport descriptor
  49  * @destroy_conn:       destroy inactive iSCSI connection
  50  * @set_param:          set iSCSI parameter. Return 0 on success, -ENODATA
  51  *                      when param is not supported, and a -Exx value on other
  52  *                      error.
  53  * @get_param           get iSCSI parameter. Must return number of bytes
  54  *                      copied to buffer on success, -ENODATA when param
  55  *                      is not supported, and a -Exx value on other error
  56  * @start_conn:         set connection to be operational
  57  * @stop_conn:          suspend/recover/terminate connection
  58  * @send_pdu:           send iSCSI PDU, Login, Logout, NOP-Out, Reject, Text.
  59  * @session_recovery_timedout: notify LLD a block during recovery timed out
  60  * @init_cmd_task:      Initialize a iscsi_cmd_task and any internal structs.
  61  *                      Called from queuecommand with session lock held.
  62  * @init_mgmt_task:     Initialize a iscsi_mgmt_task and any internal structs.
  63  *                      Called from iscsi_conn_send_generic with xmitmutex.
  64  * @xmit_cmd_task:      Requests LLD to transfer cmd task. Returns 0 or the
  65  *                      the number of bytes transferred on success, and -Exyz
  66  *                      value on error.
  67  * @xmit_mgmt_task:     Requests LLD to transfer mgmt task. Returns 0 or the
  68  *                      the number of bytes transferred on success, and -Exyz
  69  *                      value on error.
  70  * @cleanup_cmd_task:   requests LLD to fail cmd task. Called with xmitmutex
  71  *                      and session->lock after the connection has been
  72  *                      suspended and terminated during recovery. If called
  73  *                      from abort task then connection is not suspended
  74  *                      or terminated but sk_callback_lock is held
  75  *
  76  * Template API provided by iSCSI Transport
  77  */
  78 struct iscsi_transport {
  79         struct module *owner;
  80         char *name;
  81         unsigned int caps;
  82         /* LLD sets this to indicate what values it can export to sysfs */
  83         unsigned int param_mask;
  84         struct scsi_host_template *host_template;
  85         /* LLD connection data size */
  86         int conndata_size;
  87         /* LLD session data size */
  88         int sessiondata_size;
  89         int max_lun;
  90         unsigned int max_conn;
  91         unsigned int max_cmd_len;
  92         struct iscsi_cls_session *(*create_session) (struct iscsi_transport *it,
  93                 struct scsi_transport_template *t, uint32_t sn, uint32_t *hn);
  94         void (*destroy_session) (struct iscsi_cls_session *session);
  95         struct iscsi_cls_conn *(*create_conn) (struct iscsi_cls_session *sess,
  96                                 uint32_t cid);
  97         int (*bind_conn) (struct iscsi_cls_session *session,
  98                           struct iscsi_cls_conn *cls_conn,
  99                           uint64_t transport_eph, int is_leading);
 100         int (*start_conn) (struct iscsi_cls_conn *conn);
 101         void (*stop_conn) (struct iscsi_cls_conn *conn, int flag);
 102         void (*destroy_conn) (struct iscsi_cls_conn *conn);
 103         int (*set_param) (struct iscsi_cls_conn *conn, enum iscsi_param param,
 104                           char *buf, int buflen);
 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 (*send_pdu) (struct iscsi_cls_conn *conn, struct iscsi_hdr *hdr,
 110                          char *data, uint32_t data_size);
 111         void (*get_stats) (struct iscsi_cls_conn *conn,
 112                            struct iscsi_stats *stats);
 113         void (*init_cmd_task) (struct iscsi_cmd_task *ctask);
 114         void (*init_mgmt_task) (struct iscsi_conn *conn,
 115                                 struct iscsi_mgmt_task *mtask,
 116                                 char *data, uint32_t data_size);
 117         int (*xmit_cmd_task) (struct iscsi_conn *conn,
 118                               struct iscsi_cmd_task *ctask);
 119         void (*cleanup_cmd_task) (struct iscsi_conn *conn,
 120                                   struct iscsi_cmd_task *ctask);
 121         int (*xmit_mgmt_task) (struct iscsi_conn *conn,
 122                                struct iscsi_mgmt_task *mtask);
 123         void (*session_recovery_timedout) (struct iscsi_cls_session *session);
 124         int (*ep_connect) (struct sockaddr *dst_addr, int non_blocking,
 125                            uint64_t *ep_handle);
 126         int (*ep_poll) (uint64_t ep_handle, int timeout_ms);
 127         void (*ep_disconnect) (uint64_t ep_handle);
 128         int (*tgt_dscvr) (enum iscsi_tgt_dscvr type, uint32_t host_no,
 129                           uint32_t enable, struct sockaddr *dst_addr);
 130 };
 131
 132 /*
 133  * transport registration upcalls
 134  */
 135 extern struct scsi_transport_template *iscsi_register_transport(struct iscsi_transport *tt);
 136 extern int iscsi_unregister_transport(struct iscsi_transport *tt);
 137
 138 /*
 139  * control plane upcalls
 140  */
 141 extern void iscsi_conn_error(struct iscsi_cls_conn *conn, enum iscsi_err error);
 142 extern int iscsi_recv_pdu(struct iscsi_cls_conn *conn, struct iscsi_hdr *hdr,
 143                           char *data, uint32_t data_size);
 144
 145
 146 /* Connection's states */
 147 #define ISCSI_CONN_INITIAL_STAGE        0
 148 #define ISCSI_CONN_STARTED              1
 149 #define ISCSI_CONN_STOPPED              2
 150 #define ISCSI_CONN_CLEANUP_WAIT         3
 151
 152 struct iscsi_cls_conn {
 153         struct list_head conn_list;     /* item in connlist */
 154         void *dd_data;                  /* LLD private data */
 155         struct iscsi_transport *transport;
 156         uint32_t cid;                   /* connection id */
 157
 158         int active;                     /* must be accessed with the connlock */
 159         struct device dev;              /* sysfs transport/container device */
 160         struct mempool_zone *z_error;
 161         struct mempool_zone *z_pdu;
 162         struct list_head freequeue;
 163 };
 164
 165 #define iscsi_dev_to_conn(_dev) \
 166         container_of(_dev, struct iscsi_cls_conn, dev)
 167
 168 /* Session's states */
 169 #define ISCSI_STATE_FREE                1
 170 #define ISCSI_STATE_LOGGED_IN           2
 171 #define ISCSI_STATE_FAILED              3
 172 #define ISCSI_STATE_TERMINATE           4
 173 #define ISCSI_STATE_IN_RECOVERY         5
 174 #define ISCSI_STATE_RECOVERY_FAILED     6
 175
 176 struct iscsi_cls_session {
 177         struct list_head sess_list;             /* item in session_list */
 178         struct list_head host_list;
 179         struct iscsi_transport *transport;
 180
 181         /* recovery fields */
 182         int recovery_tmo;
 183         struct work_struct recovery_work;
 184
 185         int target_id;
 186
 187         int sid;                                /* session id */
 188         void *dd_data;                          /* LLD private data */
 189         struct device dev;      /* sysfs transport/container device */
 190 };
 191
 192 #define iscsi_dev_to_session(_dev) \
 193         container_of(_dev, struct iscsi_cls_session, dev)
 194
 195 #define iscsi_session_to_shost(_session) \
 196         dev_to_shost(_session->dev.parent)
 197
 198 #define starget_to_session(_stgt) \
 199         iscsi_dev_to_session(_stgt->dev.parent)
 200
 201 struct iscsi_host {
 202         struct list_head sessions;
 203         struct mutex mutex;
 204 };
 205
 206 /*
 207  * session and connection functions that can be used by HW iSCSI LLDs
 208  */
 209 extern struct iscsi_cls_session *iscsi_alloc_session(struct Scsi_Host *shost,
 210                                         struct iscsi_transport *transport);
 211 extern int iscsi_add_session(struct iscsi_cls_session *session,
 212                              unsigned int target_id);
 213 extern int iscsi_if_create_session_done(struct iscsi_cls_conn *conn);
 214 extern int iscsi_if_destroy_session_done(struct iscsi_cls_conn *conn);
 215 extern struct iscsi_cls_session *iscsi_create_session(struct Scsi_Host *shost,
 216                                                 struct iscsi_transport *t,
 217                                                 unsigned int target_id);
 218 extern void iscsi_remove_session(struct iscsi_cls_session *session);
 219 extern void iscsi_free_session(struct iscsi_cls_session *session);
 220 extern int iscsi_destroy_session(struct iscsi_cls_session *session);
 221 extern struct iscsi_cls_conn *iscsi_create_conn(struct iscsi_cls_session *sess,
 222                                             uint32_t cid);
 223 extern int iscsi_destroy_conn(struct iscsi_cls_conn *conn);
 224 extern void iscsi_unblock_session(struct iscsi_cls_session *session);
 225 extern void iscsi_block_session(struct iscsi_cls_session *session);
 226
 227
 228 #endif