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 Scsi_Host;
34 struct iscsi_cls_conn;
35 struct iscsi_conn;
36 struct iscsi_cmd_task;
37 struct iscsi_mgmt_task;
38 struct sockaddr;
39 
40 /**
41  * struct iscsi_transport - iSCSI Transport template
42  *
43  * @name:		transport name
44  * @caps:		iSCSI Data-Path capabilities
45  * @create_session:	create new iSCSI session object
46  * @destroy_session:	destroy existing iSCSI session object
47  * @create_conn:	create new iSCSI connection
48  * @bind_conn:		associate this connection with existing iSCSI session
49  *			and specified transport descriptor
50  * @destroy_conn:	destroy inactive iSCSI connection
51  * @set_param:		set iSCSI parameter. Return 0 on success, -ENODATA
52  *			when param is not supported, and a -Exx value on other
53  *			error.
54  * @get_param		get iSCSI parameter. Must return number of bytes
55  *			copied to buffer on success, -ENODATA when param
56  *			is not supported, and a -Exx value on other error
57  * @start_conn:		set connection to be operational
58  * @stop_conn:		suspend/recover/terminate connection
59  * @send_pdu:		send iSCSI PDU, Login, Logout, NOP-Out, Reject, Text.
60  * @session_recovery_timedout: notify LLD a block during recovery timed out
61  * @init_cmd_task:	Initialize a iscsi_cmd_task and any internal structs.
62  *			Called from queuecommand with session lock held.
63  * @init_mgmt_task:	Initialize a iscsi_mgmt_task and any internal structs.
64  *			Called from iscsi_conn_send_generic with xmitmutex.
65  * @xmit_cmd_task:	Requests LLD to transfer cmd task. Returns 0 or the
66  *			the number of bytes transferred on success, and -Exyz
67  *			value on error.
68  * @xmit_mgmt_task:	Requests LLD to transfer mgmt task. Returns 0 or the
69  *			the number of bytes transferred on success, and -Exyz
70  *			value on error.
71  * @cleanup_cmd_task:	requests LLD to fail cmd task. Called with xmitmutex
72  *			and session->lock after the connection has been
73  *			suspended and terminated during recovery. If called
74  *			from abort task then connection is not suspended
75  *			or terminated but sk_callback_lock is held
76  *
77  * Template API provided by iSCSI Transport
78  */
79 struct iscsi_transport {
80 	struct module *owner;
81 	char *name;
82 	unsigned int caps;
83 	/* LLD sets this to indicate what values it can export to sysfs */
84 	uint64_t param_mask;
85 	uint64_t host_param_mask;
86 	struct scsi_host_template *host_template;
87 	/* LLD connection data size */
88 	int conndata_size;
89 	/* LLD session data size */
90 	int sessiondata_size;
91 	int max_lun;
92 	unsigned int max_conn;
93 	unsigned int max_cmd_len;
94 	struct iscsi_cls_session *(*create_session) (struct iscsi_transport *it,
95 		struct scsi_transport_template *t, uint16_t, uint16_t,
96 		uint32_t sn, uint32_t *hn);
97 	void (*destroy_session) (struct iscsi_cls_session *session);
98 	struct iscsi_cls_conn *(*create_conn) (struct iscsi_cls_session *sess,
99 				uint32_t cid);
100 	int (*bind_conn) (struct iscsi_cls_session *session,
101 			  struct iscsi_cls_conn *cls_conn,
102 			  uint64_t transport_eph, int is_leading);
103 	int (*start_conn) (struct iscsi_cls_conn *conn);
104 	void (*stop_conn) (struct iscsi_cls_conn *conn, int flag);
105 	void (*destroy_conn) (struct iscsi_cls_conn *conn);
106 	int (*set_param) (struct iscsi_cls_conn *conn, enum iscsi_param param,
107 			  char *buf, int buflen);
108 	int (*get_conn_param) (struct iscsi_cls_conn *conn,
109 			       enum iscsi_param param, char *buf);
110 	int (*get_session_param) (struct iscsi_cls_session *session,
111 				  enum iscsi_param param, char *buf);
112 	int (*get_host_param) (struct Scsi_Host *shost,
113 				enum iscsi_host_param param, char *buf);
114 	int (*set_host_param) (struct Scsi_Host *shost,
115 			       enum iscsi_host_param param, char *buf,
116 			       int buflen);
117 	int (*send_pdu) (struct iscsi_cls_conn *conn, struct iscsi_hdr *hdr,
118 			 char *data, uint32_t data_size);
119 	void (*get_stats) (struct iscsi_cls_conn *conn,
120 			   struct iscsi_stats *stats);
121 	int (*init_cmd_task) (struct iscsi_cmd_task *ctask);
122 	void (*init_mgmt_task) (struct iscsi_conn *conn,
123 				struct iscsi_mgmt_task *mtask);
124 	int (*xmit_cmd_task) (struct iscsi_conn *conn,
125 			      struct iscsi_cmd_task *ctask);
126 	void (*cleanup_cmd_task) (struct iscsi_conn *conn,
127 				  struct iscsi_cmd_task *ctask);
128 	int (*xmit_mgmt_task) (struct iscsi_conn *conn,
129 			       struct iscsi_mgmt_task *mtask);
130 	void (*session_recovery_timedout) (struct iscsi_cls_session *session);
131 	int (*ep_connect) (struct sockaddr *dst_addr, int non_blocking,
132 			   uint64_t *ep_handle);
133 	int (*ep_poll) (uint64_t ep_handle, int timeout_ms);
134 	void (*ep_disconnect) (uint64_t ep_handle);
135 	int (*tgt_dscvr) (struct Scsi_Host *shost, enum iscsi_tgt_dscvr type,
136 			  uint32_t enable, struct sockaddr *dst_addr);
137 };
138 
139 /*
140  * transport registration upcalls
141  */
142 extern struct scsi_transport_template *iscsi_register_transport(struct iscsi_transport *tt);
143 extern int iscsi_unregister_transport(struct iscsi_transport *tt);
144 
145 /*
146  * control plane upcalls
147  */
148 extern void iscsi_conn_error(struct iscsi_cls_conn *conn, enum iscsi_err error);
149 extern int iscsi_recv_pdu(struct iscsi_cls_conn *conn, struct iscsi_hdr *hdr,
150 			  char *data, uint32_t data_size);
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 };
161 
162 #define iscsi_dev_to_conn(_dev) \
163 	container_of(_dev, struct iscsi_cls_conn, dev)
164 
165 #define iscsi_conn_to_session(_conn) \
166 	iscsi_dev_to_session(_conn->dev.parent)
167 
168 /* iscsi class session state */
169 enum {
170 	ISCSI_SESSION_LOGGED_IN,
171 	ISCSI_SESSION_FAILED,
172 	ISCSI_SESSION_FREE,
173 };
174 
175 struct iscsi_cls_session {
176 	struct list_head sess_list;		/* item in session_list */
177 	struct list_head host_list;
178 	struct iscsi_transport *transport;
179 	spinlock_t lock;
180 	struct work_struct block_work;
181 	struct work_struct unblock_work;
182 	struct work_struct scan_work;
183 	struct work_struct unbind_work;
184 
185 	/* recovery fields */
186 	int recovery_tmo;
187 	struct delayed_work recovery_work;
188 
189 	int target_id;
190 
191 	int state;
192 	int sid;				/* session id */
193 	void *dd_data;				/* LLD private data */
194 	struct device dev;	/* sysfs transport/container device */
195 };
196 
197 #define iscsi_dev_to_session(_dev) \
198 	container_of(_dev, struct iscsi_cls_session, dev)
199 
200 #define iscsi_session_to_shost(_session) \
201 	dev_to_shost(_session->dev.parent)
202 
203 #define starget_to_session(_stgt) \
204 	iscsi_dev_to_session(_stgt->dev.parent)
205 
206 struct iscsi_host {
207 	struct list_head sessions;
208 	atomic_t nr_scans;
209 	struct mutex mutex;
210 	struct workqueue_struct *scan_workq;
211 	char scan_workq_name[KOBJ_NAME_LEN];
212 };
213 
214 /*
215  * session and connection functions that can be used by HW iSCSI LLDs
216  */
217 #define iscsi_cls_session_printk(prefix, _cls_session, fmt, a...) \
218 	dev_printk(prefix, &(_cls_session)->dev, fmt, ##a)
219 
220 #define iscsi_cls_conn_printk(prefix, _cls_conn, fmt, a...) \
221 	dev_printk(prefix, &(_cls_conn)->dev, fmt, ##a)
222 
223 extern int iscsi_session_chkready(struct iscsi_cls_session *session);
224 extern struct iscsi_cls_session *iscsi_alloc_session(struct Scsi_Host *shost,
225 					struct iscsi_transport *transport);
226 extern int iscsi_add_session(struct iscsi_cls_session *session,
227 			     unsigned int target_id);
228 extern int iscsi_session_event(struct iscsi_cls_session *session,
229 			       enum iscsi_uevent_e event);
230 extern struct iscsi_cls_session *iscsi_create_session(struct Scsi_Host *shost,
231 						struct iscsi_transport *t,
232 						unsigned int target_id);
233 extern void iscsi_remove_session(struct iscsi_cls_session *session);
234 extern void iscsi_free_session(struct iscsi_cls_session *session);
235 extern int iscsi_destroy_session(struct iscsi_cls_session *session);
236 extern struct iscsi_cls_conn *iscsi_create_conn(struct iscsi_cls_session *sess,
237 					    uint32_t cid);
238 extern int iscsi_destroy_conn(struct iscsi_cls_conn *conn);
239 extern void iscsi_unblock_session(struct iscsi_cls_session *session);
240 extern void iscsi_block_session(struct iscsi_cls_session *session);
241 extern int iscsi_scan_finished(struct Scsi_Host *shost, unsigned long time);
242 
243 #endif
244