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
  38 /**
  39  * struct iscsi_transport - iSCSI Transport template
  40  *
  41  * @name:               transport name
  42  * @caps:               iSCSI Data-Path capabilities
  43  * @create_session:     create new iSCSI session object
  44  * @destroy_session:    destroy existing iSCSI session object
  45  * @create_conn:        create new iSCSI connection
  46  * @bind_conn:          associate this connection with existing iSCSI session
  47  *                      and specified transport descriptor
  48  * @destroy_conn:       destroy inactive iSCSI connection
  49  * @set_param:          set iSCSI Data-Path operational parameter
  50  * @start_conn:         set connection to be operational
  51  * @stop_conn:          suspend/recover/terminate connection
  52  * @send_pdu:           send iSCSI PDU, Login, Logout, NOP-Out, Reject, Text.
  53  * @session_recovery_timedout: notify LLD a block during recovery timed out
  54  * @suspend_conn_recv:  susepend the recv side of the connection
  55  * @termincate_conn:    destroy socket connection. Called with mutex lock.
  56  * @init_cmd_task:      Initialize a iscsi_cmd_task and any internal structs.
  57  *                      Called from queuecommand with session lock held.
  58  * @init_mgmt_task:     Initialize a iscsi_mgmt_task and any internal structs.
  59  *                      Called from iscsi_conn_send_generic with xmitmutex.
  60  * @xmit_cmd_task:      requests LLD to transfer cmd task
  61  * @xmit_mgmt_task:     requests LLD to transfer mgmt task
  62  * @cleanup_cmd_task:   requests LLD to fail cmd task. Called with xmitmutex
  63  *                      and session->lock after the connection has been
  64  *                      suspended and terminated during recovery. If called
  65  *                      from abort task then connection is not suspended
  66  *                      or terminated but sk_callback_lock is held
  67  *
  68  * Template API provided by iSCSI Transport
  69  */
  70 struct iscsi_transport {
  71         struct module *owner;
  72         char *name;
  73         unsigned int caps;
  74         /* LLD sets this to indicate what values it can export to sysfs */
  75         unsigned int param_mask;
  76         struct scsi_host_template *host_template;
  77         /* LLD connection data size */
  78         int conndata_size;
  79         /* LLD session data size */
  80         int sessiondata_size;
  81         int max_lun;
  82         unsigned int max_conn;
  83         unsigned int max_cmd_len;
  84         struct iscsi_cls_session *(*create_session) (struct iscsi_transport *it,
  85                 struct scsi_transport_template *t, uint32_t sn, uint32_t *hn);
  86         void (*destroy_session) (struct iscsi_cls_session *session);
  87         struct iscsi_cls_conn *(*create_conn) (struct iscsi_cls_session *sess,
  88                                 uint32_t cid);
  89         int (*bind_conn) (struct iscsi_cls_session *session,
  90                           struct iscsi_cls_conn *cls_conn,
  91                           uint32_t transport_fd, int is_leading);
  92         int (*start_conn) (struct iscsi_cls_conn *conn);
  93         void (*stop_conn) (struct iscsi_cls_conn *conn, int flag);
  94         void (*destroy_conn) (struct iscsi_cls_conn *conn);
  95         int (*set_param) (struct iscsi_cls_conn *conn, enum iscsi_param param,
  96                           uint32_t value);
  97         int (*get_conn_param) (struct iscsi_cls_conn *conn,
  98                                enum iscsi_param param, uint32_t *value);
  99         int (*get_session_param) (struct iscsi_cls_session *session,
 100                                   enum iscsi_param param, uint32_t *value);
 101         int (*get_conn_str_param) (struct iscsi_cls_conn *conn,
 102                                    enum iscsi_param param, char *buf);
 103         int (*get_session_str_param) (struct iscsi_cls_session *session,
 104                                       enum iscsi_param param, char *buf);
 105         int (*send_pdu) (struct iscsi_cls_conn *conn, struct iscsi_hdr *hdr,
 106                          char *data, uint32_t data_size);
 107         void (*get_stats) (struct iscsi_cls_conn *conn,
 108                            struct iscsi_stats *stats);
 109         void (*suspend_conn_recv) (struct iscsi_conn *conn);
 110         void (*terminate_conn) (struct iscsi_conn *conn);
 111         void (*init_cmd_task) (struct iscsi_cmd_task *ctask);
 112         void (*init_mgmt_task) (struct iscsi_conn *conn,
 113                                 struct iscsi_mgmt_task *mtask,
 114                                 char *data, uint32_t data_size);
 115         int (*xmit_cmd_task) (struct iscsi_conn *conn,
 116                               struct iscsi_cmd_task *ctask);
 117         void (*cleanup_cmd_task) (struct iscsi_conn *conn,
 118                                   struct iscsi_cmd_task *ctask);
 119         int (*xmit_mgmt_task) (struct iscsi_conn *conn,
 120                                struct iscsi_mgmt_task *mtask);
 121         void (*session_recovery_timedout) (struct iscsi_cls_session *session);
 122 };
 123
 124 /*
 125  * transport registration upcalls
 126  */
 127 extern struct scsi_transport_template *iscsi_register_transport(struct iscsi_transport *tt);
 128 extern int iscsi_unregister_transport(struct iscsi_transport *tt);
 129
 130 /*
 131  * control plane upcalls
 132  */
 133 extern void iscsi_conn_error(struct iscsi_cls_conn *conn, enum iscsi_err error);
 134 extern int iscsi_recv_pdu(struct iscsi_cls_conn *conn, struct iscsi_hdr *hdr,
 135                           char *data, uint32_t data_size);
 136
 137
 138 /* Connection's states */
 139 #define ISCSI_CONN_INITIAL_STAGE        0
 140 #define ISCSI_CONN_STARTED              1
 141 #define ISCSI_CONN_STOPPED              2
 142 #define ISCSI_CONN_CLEANUP_WAIT         3
 143
 144 struct iscsi_cls_conn {
 145         struct list_head conn_list;     /* item in connlist */
 146         void *dd_data;                  /* LLD private data */
 147         struct iscsi_transport *transport;
 148         uint32_t cid;                   /* connection id */
 149
 150         /* portal/group values we got during discovery */
 151         char *persistent_address;
 152         int persistent_port;
 153         /* portal/group values we are currently using */
 154         char *address;
 155         int port;
 156
 157         int active;                     /* must be accessed with the connlock */
 158         struct device dev;              /* sysfs transport/container device */
 159         struct mempool_zone *z_error;
 160         struct mempool_zone *z_pdu;
 161         struct list_head freequeue;
 162 };
 163
 164 #define iscsi_dev_to_conn(_dev) \
 165         container_of(_dev, struct iscsi_cls_conn, dev)
 166
 167 /* Session's states */
 168 #define ISCSI_STATE_FREE                1
 169 #define ISCSI_STATE_LOGGED_IN           2
 170 #define ISCSI_STATE_FAILED              3
 171 #define ISCSI_STATE_TERMINATE           4
 172
 173 struct iscsi_cls_session {
 174         struct list_head sess_list;             /* item in session_list */
 175         struct list_head host_list;
 176         struct iscsi_transport *transport;
 177
 178         /* iSCSI values used as unique id by userspace. */
 179         char *targetname;
 180         int tpgt;
 181
 182         /* recovery fields */
 183         int recovery_tmo;
 184         struct work_struct recovery_work;
 185
 186         int target_id;
 187         int channel;
 188
 189         int sid;                                /* session id */
 190         void *dd_data;                          /* LLD private data */
 191         struct device dev;      /* sysfs transport/container device */
 192 };
 193
 194 #define iscsi_dev_to_session(_dev) \
 195         container_of(_dev, struct iscsi_cls_session, dev)
 196
 197 #define iscsi_session_to_shost(_session) \
 198         dev_to_shost(_session->dev.parent)
 199
 200 struct iscsi_host {
 201         int next_target_id;
 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_create_session(struct Scsi_Host *shost,
 210                                 struct iscsi_transport *t, int channel);
 211 extern int iscsi_destroy_session(struct iscsi_cls_session *session);
 212 extern struct iscsi_cls_conn *iscsi_create_conn(struct iscsi_cls_session *sess,
 213                                             uint32_t cid);
 214 extern int iscsi_destroy_conn(struct iscsi_cls_conn *conn);
 215 extern void iscsi_unblock_session(struct iscsi_cls_session *session);
 216 extern void iscsi_block_session(struct iscsi_cls_session *session);
 217
 218 #endif