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
297