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 struct bsg_job;
42 
43 /**
44  * struct iscsi_transport - iSCSI Transport template
45  *
46  * @name:		transport name
47  * @caps:		iSCSI Data-Path capabilities
48  * @create_session:	create new iSCSI session object
49  * @destroy_session:	destroy existing iSCSI session object
50  * @create_conn:	create new iSCSI connection
51  * @bind_conn:		associate this connection with existing iSCSI session
52  *			and specified transport descriptor
53  * @destroy_conn:	destroy inactive iSCSI connection
54  * @set_param:		set iSCSI parameter. Return 0 on success, -ENODATA
55  *			when param is not supported, and a -Exx value on other
56  *			error.
57  * @get_param		get iSCSI parameter. Must return number of bytes
58  *			copied to buffer on success, -ENODATA when param
59  *			is not supported, and a -Exx value on other error
60  * @start_conn:		set connection to be operational
61  * @stop_conn:		suspend/recover/terminate connection
62  * @send_pdu:		send iSCSI PDU, Login, Logout, NOP-Out, Reject, Text.
63  * @session_recovery_timedout: notify LLD a block during recovery timed out
64  * @init_task:		Initialize a iscsi_task and any internal structs.
65  *			When offloading the data path, this is called from
66  *			queuecommand with the session lock, or from the
67  *			iscsi_conn_send_pdu context with the session lock.
68  *			When not offloading the data path, this is called
69  *			from the scsi work queue without the session lock.
70  * @xmit_task		Requests LLD to transfer cmd task. Returns 0 or the
71  *			the number of bytes transferred on success, and -Exyz
72  *			value on error. When offloading the data path, this
73  *			is called from queuecommand with the session lock, or
74  *			from the iscsi_conn_send_pdu context with the session
75  *			lock. When not offloading the data path, this is called
76  *			from the scsi work queue without the session lock.
77  * @cleanup_task:	requests LLD to fail task. Called with session lock
78  *			and after the connection has been suspended and
79  *			terminated during recovery. If called
80  *			from abort task then connection is not suspended
81  *			or terminated but sk_callback_lock is held
82  *
83  * Template API provided by iSCSI Transport
84  */
85 struct iscsi_transport {
86 	struct module *owner;
87 	char *name;
88 	unsigned int caps;
89 
90 	struct iscsi_cls_session *(*create_session) (struct iscsi_endpoint *ep,
91 					uint16_t cmds_max, uint16_t qdepth,
92 					uint32_t sn);
93 	void (*destroy_session) (struct iscsi_cls_session *session);
94 	struct iscsi_cls_conn *(*create_conn) (struct iscsi_cls_session *sess,
95 				uint32_t cid);
96 	int (*bind_conn) (struct iscsi_cls_session *session,
97 			  struct iscsi_cls_conn *cls_conn,
98 			  uint64_t transport_eph, int is_leading);
99 	int (*start_conn) (struct iscsi_cls_conn *conn);
100 	void (*stop_conn) (struct iscsi_cls_conn *conn, int flag);
101 	void (*destroy_conn) (struct iscsi_cls_conn *conn);
102 	int (*set_param) (struct iscsi_cls_conn *conn, enum iscsi_param param,
103 			  char *buf, int buflen);
104 	int (*get_ep_param) (struct iscsi_endpoint *ep, enum iscsi_param param,
105 			     char *buf);
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 
120 	int (*init_task) (struct iscsi_task *task);
121 	int (*xmit_task) (struct iscsi_task *task);
122 	void (*cleanup_task) (struct iscsi_task *task);
123 
124 	int (*alloc_pdu) (struct iscsi_task *task, uint8_t opcode);
125 	int (*xmit_pdu) (struct iscsi_task *task);
126 	int (*init_pdu) (struct iscsi_task *task, unsigned int offset,
127 			 unsigned int count);
128 	void (*parse_pdu_itt) (struct iscsi_conn *conn, itt_t itt,
129 			       int *index, int *age);
130 
131 	void (*session_recovery_timedout) (struct iscsi_cls_session *session);
132 	struct iscsi_endpoint *(*ep_connect) (struct Scsi_Host *shost,
133 					      struct sockaddr *dst_addr,
134 					      int non_blocking);
135 	int (*ep_poll) (struct iscsi_endpoint *ep, int timeout_ms);
136 	void (*ep_disconnect) (struct iscsi_endpoint *ep);
137 	int (*tgt_dscvr) (struct Scsi_Host *shost, enum iscsi_tgt_dscvr type,
138 			  uint32_t enable, struct sockaddr *dst_addr);
139 	int (*set_path) (struct Scsi_Host *shost, struct iscsi_path *params);
140 	int (*set_iface_param) (struct Scsi_Host *shost, void *data,
141 				uint32_t len);
142 	int (*get_iface_param) (struct iscsi_iface *iface,
143 				enum iscsi_param_type param_type,
144 				int param, char *buf);
145 	umode_t (*attr_is_visible)(int param_type, int param);
146 	int (*bsg_request)(struct bsg_job *job);
147 	int (*send_ping) (struct Scsi_Host *shost, uint32_t iface_num,
148 			  uint32_t iface_type, uint32_t payload_size,
149 			  uint32_t pid, struct sockaddr *dst_addr);
150 };
151 
152 /*
153  * transport registration upcalls
154  */
155 extern struct scsi_transport_template *iscsi_register_transport(struct iscsi_transport *tt);
156 extern int iscsi_unregister_transport(struct iscsi_transport *tt);
157 
158 /*
159  * control plane upcalls
160  */
161 extern void iscsi_conn_error_event(struct iscsi_cls_conn *conn,
162 				   enum iscsi_err error);
163 extern void iscsi_conn_login_event(struct iscsi_cls_conn *conn,
164 				   enum iscsi_conn_state state);
165 extern int iscsi_recv_pdu(struct iscsi_cls_conn *conn, struct iscsi_hdr *hdr,
166 			  char *data, uint32_t data_size);
167 
168 extern int iscsi_offload_mesg(struct Scsi_Host *shost,
169 			      struct iscsi_transport *transport, uint32_t type,
170 			      char *data, uint16_t data_size);
171 
172 extern void iscsi_post_host_event(uint32_t host_no,
173 				  struct iscsi_transport *transport,
174 				  enum iscsi_host_event_code code,
175 				  uint32_t data_size,
176 				  uint8_t *data);
177 
178 extern void iscsi_ping_comp_event(uint32_t host_no,
179 				  struct iscsi_transport *transport,
180 				  uint32_t status, uint32_t pid,
181 				  uint32_t data_size, uint8_t *data);
182 
183 struct iscsi_cls_conn {
184 	struct list_head conn_list;	/* item in connlist */
185 	void *dd_data;			/* LLD private data */
186 	struct iscsi_transport *transport;
187 	uint32_t cid;			/* connection id */
188 	struct mutex ep_mutex;
189 	struct iscsi_endpoint *ep;
190 
191 	struct device dev;		/* sysfs transport/container device */
192 };
193 
194 #define iscsi_dev_to_conn(_dev) \
195 	container_of(_dev, struct iscsi_cls_conn, dev)
196 
197 #define transport_class_to_conn(_cdev) \
198 	iscsi_dev_to_conn(_cdev->parent)
199 
200 #define iscsi_conn_to_session(_conn) \
201 	iscsi_dev_to_session(_conn->dev.parent)
202 
203 /* iscsi class session state */
204 enum {
205 	ISCSI_SESSION_LOGGED_IN,
206 	ISCSI_SESSION_FAILED,
207 	ISCSI_SESSION_FREE,
208 };
209 
210 #define ISCSI_MAX_TARGET -1
211 
212 struct iscsi_cls_session {
213 	struct list_head sess_list;		/* item in session_list */
214 	struct iscsi_transport *transport;
215 	spinlock_t lock;
216 	struct work_struct block_work;
217 	struct work_struct unblock_work;
218 	struct work_struct scan_work;
219 	struct work_struct unbind_work;
220 
221 	/* recovery fields */
222 	int recovery_tmo;
223 	struct delayed_work recovery_work;
224 
225 	unsigned int target_id;
226 	bool ida_used;
227 
228 	/*
229 	 * pid of userspace process that created session or -1 if
230 	 * created by the kernel.
231 	 */
232 	pid_t creator;
233 	int state;
234 	int sid;				/* session id */
235 	void *dd_data;				/* LLD private data */
236 	struct device dev;	/* sysfs transport/container device */
237 };
238 
239 #define iscsi_dev_to_session(_dev) \
240 	container_of(_dev, struct iscsi_cls_session, dev)
241 
242 #define transport_class_to_session(_cdev) \
243 	iscsi_dev_to_session(_cdev->parent)
244 
245 #define iscsi_session_to_shost(_session) \
246 	dev_to_shost(_session->dev.parent)
247 
248 #define starget_to_session(_stgt) \
249 	iscsi_dev_to_session(_stgt->dev.parent)
250 
251 struct iscsi_cls_host {
252 	atomic_t nr_scans;
253 	struct mutex mutex;
254 	struct request_queue *bsg_q;
255 	uint32_t port_speed;
256 	uint32_t port_state;
257 };
258 
259 #define iscsi_job_to_shost(_job) \
260         dev_to_shost(_job->dev)
261 
262 extern void iscsi_host_for_each_session(struct Scsi_Host *shost,
263 				void (*fn)(struct iscsi_cls_session *));
264 
265 struct iscsi_endpoint {
266 	void *dd_data;			/* LLD private data */
267 	struct device dev;
268 	uint64_t id;
269 	struct iscsi_cls_conn *conn;
270 };
271 
272 struct iscsi_iface {
273 	struct device dev;
274 	struct iscsi_transport *transport;
275 	uint32_t iface_type;	/* IPv4 or IPv6 */
276 	uint32_t iface_num;	/* iface number, 0 - n */
277 	void *dd_data;		/* LLD private data */
278 };
279 
280 #define iscsi_dev_to_iface(_dev) \
281 	container_of(_dev, struct iscsi_iface, dev)
282 
283 #define iscsi_iface_to_shost(_iface) \
284 	dev_to_shost(_iface->dev.parent)
285 
286 /*
287  * session and connection functions that can be used by HW iSCSI LLDs
288  */
289 #define iscsi_cls_session_printk(prefix, _cls_session, fmt, a...) \
290 	dev_printk(prefix, &(_cls_session)->dev, fmt, ##a)
291 
292 #define iscsi_cls_conn_printk(prefix, _cls_conn, fmt, a...) \
293 	dev_printk(prefix, &(_cls_conn)->dev, fmt, ##a)
294 
295 extern int iscsi_session_chkready(struct iscsi_cls_session *session);
296 extern int iscsi_is_session_online(struct iscsi_cls_session *session);
297 extern struct iscsi_cls_session *iscsi_alloc_session(struct Scsi_Host *shost,
298 				struct iscsi_transport *transport, int dd_size);
299 extern int iscsi_add_session(struct iscsi_cls_session *session,
300 			     unsigned int target_id);
301 extern int iscsi_session_event(struct iscsi_cls_session *session,
302 			       enum iscsi_uevent_e event);
303 extern struct iscsi_cls_session *iscsi_create_session(struct Scsi_Host *shost,
304 						struct iscsi_transport *t,
305 						int dd_size,
306 						unsigned int target_id);
307 extern void iscsi_remove_session(struct iscsi_cls_session *session);
308 extern void iscsi_free_session(struct iscsi_cls_session *session);
309 extern int iscsi_destroy_session(struct iscsi_cls_session *session);
310 extern struct iscsi_cls_conn *iscsi_create_conn(struct iscsi_cls_session *sess,
311 						int dd_size, uint32_t cid);
312 extern int iscsi_destroy_conn(struct iscsi_cls_conn *conn);
313 extern void iscsi_unblock_session(struct iscsi_cls_session *session);
314 extern void iscsi_block_session(struct iscsi_cls_session *session);
315 extern int iscsi_scan_finished(struct Scsi_Host *shost, unsigned long time);
316 extern struct iscsi_endpoint *iscsi_create_endpoint(int dd_size);
317 extern void iscsi_destroy_endpoint(struct iscsi_endpoint *ep);
318 extern struct iscsi_endpoint *iscsi_lookup_endpoint(u64 handle);
319 extern int iscsi_block_scsi_eh(struct scsi_cmnd *cmd);
320 extern struct iscsi_iface *iscsi_create_iface(struct Scsi_Host *shost,
321 					      struct iscsi_transport *t,
322 					      uint32_t iface_type,
323 					      uint32_t iface_num, int dd_size);
324 extern void iscsi_destroy_iface(struct iscsi_iface *iface);
325 extern struct iscsi_iface *iscsi_lookup_iface(int handle);
326 extern char *iscsi_get_port_speed_name(struct Scsi_Host *shost);
327 extern char *iscsi_get_port_state_name(struct Scsi_Host *shost);
328 
329 #endif
330