xref: /linux/include/scsi/scsi_transport_iscsi.h (revision 2b8232ce512105e28453f301d1510de8363bccd1)
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 iscsi_cls_conn;
33 struct iscsi_conn;
34 struct iscsi_cmd_task;
35 struct iscsi_mgmt_task;
36 struct sockaddr;
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 parameter. Return 0 on success, -ENODATA
50  *			when param is not supported, and a -Exx value on other
51  *			error.
52  * @get_param		get iSCSI parameter. Must return number of bytes
53  *			copied to buffer on success, -ENODATA when param
54  *			is not supported, and a -Exx value on other error
55  * @start_conn:		set connection to be operational
56  * @stop_conn:		suspend/recover/terminate connection
57  * @send_pdu:		send iSCSI PDU, Login, Logout, NOP-Out, Reject, Text.
58  * @session_recovery_timedout: notify LLD a block during recovery timed out
59  * @init_cmd_task:	Initialize a iscsi_cmd_task and any internal structs.
60  *			Called from queuecommand with session lock held.
61  * @init_mgmt_task:	Initialize a iscsi_mgmt_task and any internal structs.
62  *			Called from iscsi_conn_send_generic with xmitmutex.
63  * @xmit_cmd_task:	Requests LLD to transfer cmd task. Returns 0 or the
64  *			the number of bytes transferred on success, and -Exyz
65  *			value on error.
66  * @xmit_mgmt_task:	Requests LLD to transfer mgmt task. Returns 0 or the
67  *			the number of bytes transferred on success, and -Exyz
68  *			value on error.
69  * @cleanup_cmd_task:	requests LLD to fail cmd task. Called with xmitmutex
70  *			and session->lock after the connection has been
71  *			suspended and terminated during recovery. If called
72  *			from abort task then connection is not suspended
73  *			or terminated but sk_callback_lock is held
74  *
75  * Template API provided by iSCSI Transport
76  */
77 struct iscsi_transport {
78 	struct module *owner;
79 	char *name;
80 	unsigned int caps;
81 	/* LLD sets this to indicate what values it can export to sysfs */
82 	uint64_t param_mask;
83 	uint64_t host_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, uint16_t, uint16_t,
94 		uint32_t sn, uint32_t *hn);
95 	void (*destroy_session) (struct iscsi_cls_session *session);
96 	struct iscsi_cls_conn *(*create_conn) (struct iscsi_cls_session *sess,
97 				uint32_t cid);
98 	int (*bind_conn) (struct iscsi_cls_session *session,
99 			  struct iscsi_cls_conn *cls_conn,
100 			  uint64_t transport_eph, int is_leading);
101 	int (*start_conn) (struct iscsi_cls_conn *conn);
102 	void (*stop_conn) (struct iscsi_cls_conn *conn, int flag);
103 	void (*destroy_conn) (struct iscsi_cls_conn *conn);
104 	int (*set_param) (struct iscsi_cls_conn *conn, enum iscsi_param param,
105 			  char *buf, int buflen);
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 	void (*init_cmd_task) (struct iscsi_cmd_task *ctask);
120 	void (*init_mgmt_task) (struct iscsi_conn *conn,
121 				struct iscsi_mgmt_task *mtask);
122 	int (*xmit_cmd_task) (struct iscsi_conn *conn,
123 			      struct iscsi_cmd_task *ctask);
124 	void (*cleanup_cmd_task) (struct iscsi_conn *conn,
125 				  struct iscsi_cmd_task *ctask);
126 	int (*xmit_mgmt_task) (struct iscsi_conn *conn,
127 			       struct iscsi_mgmt_task *mtask);
128 	void (*session_recovery_timedout) (struct iscsi_cls_session *session);
129 	int (*ep_connect) (struct sockaddr *dst_addr, int non_blocking,
130 			   uint64_t *ep_handle);
131 	int (*ep_poll) (uint64_t ep_handle, int timeout_ms);
132 	void (*ep_disconnect) (uint64_t ep_handle);
133 	int (*tgt_dscvr) (struct Scsi_Host *shost, enum iscsi_tgt_dscvr type,
134 			  uint32_t enable, struct sockaddr *dst_addr);
135 };
136 
137 /*
138  * transport registration upcalls
139  */
140 extern struct scsi_transport_template *iscsi_register_transport(struct iscsi_transport *tt);
141 extern int iscsi_unregister_transport(struct iscsi_transport *tt);
142 
143 /*
144  * control plane upcalls
145  */
146 extern void iscsi_conn_error(struct iscsi_cls_conn *conn, enum iscsi_err error);
147 extern int iscsi_recv_pdu(struct iscsi_cls_conn *conn, struct iscsi_hdr *hdr,
148 			  char *data, uint32_t data_size);
149 
150 
151 /* Connection's states */
152 #define ISCSI_CONN_INITIAL_STAGE	0
153 #define ISCSI_CONN_STARTED		1
154 #define ISCSI_CONN_STOPPED		2
155 #define ISCSI_CONN_CLEANUP_WAIT		3
156 
157 struct iscsi_cls_conn {
158 	struct list_head conn_list;	/* item in connlist */
159 	void *dd_data;			/* LLD private data */
160 	struct iscsi_transport *transport;
161 	uint32_t cid;			/* connection id */
162 
163 	int active;			/* must be accessed with the connlock */
164 	struct device dev;		/* sysfs transport/container device */
165 };
166 
167 #define iscsi_dev_to_conn(_dev) \
168 	container_of(_dev, struct iscsi_cls_conn, dev)
169 
170 /* Session's states */
171 #define ISCSI_STATE_FREE		1
172 #define ISCSI_STATE_LOGGED_IN		2
173 #define ISCSI_STATE_FAILED		3
174 #define ISCSI_STATE_TERMINATE		4
175 #define ISCSI_STATE_IN_RECOVERY		5
176 #define ISCSI_STATE_RECOVERY_FAILED	6
177 
178 struct iscsi_cls_session {
179 	struct list_head sess_list;		/* item in session_list */
180 	struct list_head host_list;
181 	struct iscsi_transport *transport;
182 
183 	/* recovery fields */
184 	int recovery_tmo;
185 	struct delayed_work recovery_work;
186 
187 	int target_id;
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 #define starget_to_session(_stgt) \
201 	iscsi_dev_to_session(_stgt->dev.parent)
202 
203 struct iscsi_host {
204 	struct list_head sessions;
205 	struct mutex mutex;
206 };
207 
208 /*
209  * session and connection functions that can be used by HW iSCSI LLDs
210  */
211 extern struct iscsi_cls_session *iscsi_alloc_session(struct Scsi_Host *shost,
212 					struct iscsi_transport *transport);
213 extern int iscsi_add_session(struct iscsi_cls_session *session,
214 			     unsigned int target_id);
215 extern int iscsi_if_create_session_done(struct iscsi_cls_conn *conn);
216 extern int iscsi_if_destroy_session_done(struct iscsi_cls_conn *conn);
217 extern struct iscsi_cls_session *iscsi_create_session(struct Scsi_Host *shost,
218 						struct iscsi_transport *t,
219 						unsigned int target_id);
220 extern void iscsi_remove_session(struct iscsi_cls_session *session);
221 extern void iscsi_free_session(struct iscsi_cls_session *session);
222 extern int iscsi_destroy_session(struct iscsi_cls_session *session);
223 extern struct iscsi_cls_conn *iscsi_create_conn(struct iscsi_cls_session *sess,
224 					    uint32_t cid);
225 extern int iscsi_destroy_conn(struct iscsi_cls_conn *conn);
226 extern void iscsi_unblock_session(struct iscsi_cls_session *session);
227 extern void iscsi_block_session(struct iscsi_cls_session *session);
228 
229 
230 #endif
231