xref: /openbmc/linux/include/scsi/libiscsi.h (revision b627b4ed)
1 /*
2  * iSCSI lib definitions
3  *
4  * Copyright (C) 2006 Red Hat, Inc.  All rights reserved.
5  * Copyright (C) 2004 - 2006 Mike Christie
6  * Copyright (C) 2004 - 2005 Dmitry Yusupov
7  * Copyright (C) 2004 - 2005 Alex Aizman
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 LIBISCSI_H
24 #define LIBISCSI_H
25 
26 #include <linux/types.h>
27 #include <linux/wait.h>
28 #include <linux/mutex.h>
29 #include <linux/timer.h>
30 #include <linux/workqueue.h>
31 #include <scsi/iscsi_proto.h>
32 #include <scsi/iscsi_if.h>
33 #include <scsi/scsi_transport_iscsi.h>
34 
35 struct scsi_transport_template;
36 struct scsi_host_template;
37 struct scsi_device;
38 struct Scsi_Host;
39 struct scsi_cmnd;
40 struct socket;
41 struct iscsi_transport;
42 struct iscsi_cls_session;
43 struct iscsi_cls_conn;
44 struct iscsi_session;
45 struct iscsi_nopin;
46 struct device;
47 
48 #define ISCSI_DEF_XMIT_CMDS_MAX	128	/* must be power of 2 */
49 #define ISCSI_MGMT_CMDS_MAX	15
50 
51 #define ISCSI_DEF_CMD_PER_LUN	32
52 
53 /* Task Mgmt states */
54 enum {
55 	TMF_INITIAL,
56 	TMF_QUEUED,
57 	TMF_SUCCESS,
58 	TMF_FAILED,
59 	TMF_TIMEDOUT,
60 	TMF_NOT_FOUND,
61 };
62 
63 /* Connection suspend "bit" */
64 #define ISCSI_SUSPEND_BIT		1
65 
66 #define ISCSI_ITT_MASK			0x1fff
67 #define ISCSI_TOTAL_CMDS_MAX		4096
68 /* this must be a power of two greater than ISCSI_MGMT_CMDS_MAX */
69 #define ISCSI_TOTAL_CMDS_MIN		16
70 #define ISCSI_AGE_SHIFT			28
71 #define ISCSI_AGE_MASK			0xf
72 
73 #define ISCSI_ADDRESS_BUF_LEN		64
74 
75 enum {
76 	/* this is the maximum possible storage for AHSs */
77 	ISCSI_MAX_AHS_SIZE = sizeof(struct iscsi_ecdb_ahdr) +
78 				sizeof(struct iscsi_rlength_ahdr),
79 	ISCSI_DIGEST_SIZE = sizeof(__u32),
80 };
81 
82 
83 enum {
84 	ISCSI_TASK_COMPLETED,
85 	ISCSI_TASK_PENDING,
86 	ISCSI_TASK_RUNNING,
87 };
88 
89 struct iscsi_r2t_info {
90 	__be32			ttt;		/* copied from R2T */
91 	__be32			exp_statsn;	/* copied from R2T */
92 	uint32_t		data_length;	/* copied from R2T */
93 	uint32_t		data_offset;	/* copied from R2T */
94 	int			data_count;	/* DATA-Out payload progress */
95 	int			datasn;
96 	/* LLDs should set/update these values */
97 	int			sent;		/* R2T sequence progress */
98 };
99 
100 struct iscsi_task {
101 	/*
102 	 * Because LLDs allocate their hdr differently, this is a pointer
103 	 * and length to that storage. It must be setup at session
104 	 * creation time.
105 	 */
106 	struct iscsi_hdr	*hdr;
107 	unsigned short		hdr_max;
108 	unsigned short		hdr_len;	/* accumulated size of hdr used */
109 	/* copied values in case we need to send tmfs */
110 	itt_t			hdr_itt;
111 	__be32			cmdsn;
112 	uint8_t			lun[8];
113 
114 	int			itt;		/* this ITT */
115 
116 	unsigned		imm_count;	/* imm-data (bytes)   */
117 	/* offset in unsolicited stream (bytes); */
118 	struct iscsi_r2t_info	unsol_r2t;
119 	char			*data;		/* mgmt payload */
120 	unsigned		data_count;
121 	struct scsi_cmnd	*sc;		/* associated SCSI cmd*/
122 	struct iscsi_conn	*conn;		/* used connection    */
123 
124 	/* state set/tested under session->lock */
125 	int			state;
126 	atomic_t		refcount;
127 	struct list_head	running;	/* running cmd list */
128 	void			*dd_data;	/* driver/transport data */
129 };
130 
131 static inline int iscsi_task_has_unsol_data(struct iscsi_task *task)
132 {
133 	return task->unsol_r2t.data_length > task->unsol_r2t.sent;
134 }
135 
136 static inline void* iscsi_next_hdr(struct iscsi_task *task)
137 {
138 	return (void*)task->hdr + task->hdr_len;
139 }
140 
141 /* Connection's states */
142 enum {
143 	ISCSI_CONN_INITIAL_STAGE,
144 	ISCSI_CONN_STARTED,
145 	ISCSI_CONN_STOPPED,
146 	ISCSI_CONN_CLEANUP_WAIT,
147 };
148 
149 struct iscsi_conn {
150 	struct iscsi_cls_conn	*cls_conn;	/* ptr to class connection */
151 	void			*dd_data;	/* iscsi_transport data */
152 	struct iscsi_session	*session;	/* parent session */
153 	/*
154 	 * conn_stop() flag: stop to recover, stop to terminate
155 	 */
156         int			stop_stage;
157 	struct timer_list	transport_timer;
158 	unsigned long		last_recv;
159 	unsigned long		last_ping;
160 	int			ping_timeout;
161 	int			recv_timeout;
162 	struct iscsi_task 	*ping_task;
163 
164 	/* iSCSI connection-wide sequencing */
165 	uint32_t		exp_statsn;
166 
167 	/* control data */
168 	int			id;		/* CID */
169 	int			c_stage;	/* connection state */
170 	/*
171 	 * Preallocated buffer for pdus that have data but do not
172 	 * originate from scsi-ml. We never have two pdus using the
173 	 * buffer at the same time. It is only allocated to
174 	 * the default max recv size because the pdus we support
175 	 * should always fit in this buffer
176 	 */
177 	char			*data;
178 	struct iscsi_task 	*login_task;	/* mtask used for login/text */
179 	struct iscsi_task	*task;		/* xmit task in progress */
180 
181 	/* xmit */
182 	struct list_head	mgmtqueue;	/* mgmt (control) xmit queue */
183 	struct list_head	mgmt_run_list;	/* list of control tasks */
184 	struct list_head	xmitqueue;	/* data-path cmd queue */
185 	struct list_head	run_list;	/* list of cmds in progress */
186 	struct list_head	requeue;	/* tasks needing another run */
187 	struct work_struct	xmitwork;	/* per-conn. xmit workqueue */
188 	unsigned long		suspend_tx;	/* suspend Tx */
189 	unsigned long		suspend_rx;	/* suspend Rx */
190 
191 	/* abort */
192 	wait_queue_head_t	ehwait;		/* used in eh_abort() */
193 	struct iscsi_tm		tmhdr;
194 	struct timer_list	tmf_timer;
195 	int			tmf_state;	/* see TMF_INITIAL, etc.*/
196 
197 	/* negotiated params */
198 	unsigned		max_recv_dlength; /* initiator_max_recv_dsl*/
199 	unsigned		max_xmit_dlength; /* target_max_recv_dsl */
200 	int			hdrdgst_en;
201 	int			datadgst_en;
202 	int			ifmarker_en;
203 	int			ofmarker_en;
204 	/* values userspace uses to id a conn */
205 	int			persistent_port;
206 	char			*persistent_address;
207 	/* remote portal currently connected to */
208 	int			portal_port;
209 	char			portal_address[ISCSI_ADDRESS_BUF_LEN];
210 
211 	/* MIB-statistics */
212 	uint64_t		txdata_octets;
213 	uint64_t		rxdata_octets;
214 	uint32_t		scsicmd_pdus_cnt;
215 	uint32_t		dataout_pdus_cnt;
216 	uint32_t		scsirsp_pdus_cnt;
217 	uint32_t		datain_pdus_cnt;
218 	uint32_t		r2t_pdus_cnt;
219 	uint32_t		tmfcmd_pdus_cnt;
220 	int32_t			tmfrsp_pdus_cnt;
221 
222 	/* custom statistics */
223 	uint32_t		eh_abort_cnt;
224 	uint32_t		fmr_unalign_cnt;
225 };
226 
227 struct iscsi_pool {
228 	struct kfifo		*queue;		/* FIFO Queue */
229 	void			**pool;		/* Pool of elements */
230 	int			max;		/* Max number of elements */
231 };
232 
233 /* Session's states */
234 enum {
235 	ISCSI_STATE_FREE = 1,
236 	ISCSI_STATE_LOGGED_IN,
237 	ISCSI_STATE_FAILED,
238 	ISCSI_STATE_TERMINATE,
239 	ISCSI_STATE_IN_RECOVERY,
240 	ISCSI_STATE_RECOVERY_FAILED,
241 	ISCSI_STATE_LOGGING_OUT,
242 };
243 
244 struct iscsi_session {
245 	struct iscsi_cls_session *cls_session;
246 	/*
247 	 * Syncs up the scsi eh thread with the iscsi eh thread when sending
248 	 * task management functions. This must be taken before the session
249 	 * and recv lock.
250 	 */
251 	struct mutex		eh_mutex;
252 
253 	/* iSCSI session-wide sequencing */
254 	uint32_t		cmdsn;
255 	uint32_t		exp_cmdsn;
256 	uint32_t		max_cmdsn;
257 
258 	/* This tracks the reqs queued into the initiator */
259 	uint32_t		queued_cmdsn;
260 
261 	/* configuration */
262 	int			abort_timeout;
263 	int			lu_reset_timeout;
264 	int			initial_r2t_en;
265 	unsigned		max_r2t;
266 	int			imm_data_en;
267 	unsigned		first_burst;
268 	unsigned		max_burst;
269 	int			time2wait;
270 	int			time2retain;
271 	int			pdu_inorder_en;
272 	int			dataseq_inorder_en;
273 	int			erl;
274 	int			fast_abort;
275 	int			tpgt;
276 	char			*username;
277 	char			*username_in;
278 	char			*password;
279 	char			*password_in;
280 	char			*targetname;
281 	char			*ifacename;
282 	char			*initiatorname;
283 	/* control data */
284 	struct iscsi_transport	*tt;
285 	struct Scsi_Host	*host;
286 	struct iscsi_conn	*leadconn;	/* leading connection */
287 	spinlock_t		lock;		/* protects session state, *
288 						 * sequence numbers,       *
289 						 * session resources:      *
290 						 * - cmdpool,		   *
291 						 * - mgmtpool,		   *
292 						 * - r2tpool		   */
293 	int			state;		/* session state           */
294 	int			age;		/* counts session re-opens */
295 
296 	int			scsi_cmds_max; 	/* max scsi commands */
297 	int			cmds_max;	/* size of cmds array */
298 	struct iscsi_task	**cmds;		/* Original Cmds arr */
299 	struct iscsi_pool	cmdpool;	/* PDU's pool */
300 };
301 
302 enum {
303 	ISCSI_HOST_SETUP,
304 	ISCSI_HOST_REMOVED,
305 };
306 
307 struct iscsi_host {
308 	char			*initiatorname;
309 	/* hw address or netdev iscsi connection is bound to */
310 	char			*hwaddress;
311 	char			*netdev;
312 	/* local address */
313 	int			local_port;
314 	char			local_address[ISCSI_ADDRESS_BUF_LEN];
315 
316 	wait_queue_head_t	session_removal_wq;
317 	/* protects sessions and state */
318 	spinlock_t		lock;
319 	int			num_sessions;
320 	int			state;
321 
322 	struct workqueue_struct	*workq;
323 	char			workq_name[20];
324 };
325 
326 /*
327  * scsi host template
328  */
329 extern int iscsi_change_queue_depth(struct scsi_device *sdev, int depth);
330 extern int iscsi_eh_abort(struct scsi_cmnd *sc);
331 extern int iscsi_eh_target_reset(struct scsi_cmnd *sc);
332 extern int iscsi_eh_device_reset(struct scsi_cmnd *sc);
333 extern int iscsi_queuecommand(struct scsi_cmnd *sc,
334 			      void (*done)(struct scsi_cmnd *));
335 
336 /*
337  * iSCSI host helpers.
338  */
339 #define iscsi_host_priv(_shost) \
340 	(shost_priv(_shost) + sizeof(struct iscsi_host))
341 
342 extern int iscsi_host_set_param(struct Scsi_Host *shost,
343 				enum iscsi_host_param param, char *buf,
344 				int buflen);
345 extern int iscsi_host_get_param(struct Scsi_Host *shost,
346 				enum iscsi_host_param param, char *buf);
347 extern int iscsi_host_add(struct Scsi_Host *shost, struct device *pdev);
348 extern struct Scsi_Host *iscsi_host_alloc(struct scsi_host_template *sht,
349 					  int dd_data_size,
350 					  bool xmit_can_sleep);
351 extern void iscsi_host_remove(struct Scsi_Host *shost);
352 extern void iscsi_host_free(struct Scsi_Host *shost);
353 
354 /*
355  * session management
356  */
357 extern struct iscsi_cls_session *
358 iscsi_session_setup(struct iscsi_transport *, struct Scsi_Host *shost,
359 		    uint16_t, int, uint32_t, unsigned int);
360 extern void iscsi_session_teardown(struct iscsi_cls_session *);
361 extern void iscsi_session_recovery_timedout(struct iscsi_cls_session *);
362 extern int iscsi_set_param(struct iscsi_cls_conn *cls_conn,
363 			   enum iscsi_param param, char *buf, int buflen);
364 extern int iscsi_session_get_param(struct iscsi_cls_session *cls_session,
365 				   enum iscsi_param param, char *buf);
366 
367 #define iscsi_session_printk(prefix, _sess, fmt, a...)	\
368 	iscsi_cls_session_printk(prefix, _sess->cls_session, fmt, ##a)
369 
370 /*
371  * connection management
372  */
373 extern struct iscsi_cls_conn *iscsi_conn_setup(struct iscsi_cls_session *,
374 					       int, uint32_t);
375 extern void iscsi_conn_teardown(struct iscsi_cls_conn *);
376 extern int iscsi_conn_start(struct iscsi_cls_conn *);
377 extern void iscsi_conn_stop(struct iscsi_cls_conn *, int);
378 extern int iscsi_conn_bind(struct iscsi_cls_session *, struct iscsi_cls_conn *,
379 			   int);
380 extern void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err);
381 extern void iscsi_session_failure(struct iscsi_session *session,
382 				  enum iscsi_err err);
383 extern int iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
384 				enum iscsi_param param, char *buf);
385 extern void iscsi_suspend_tx(struct iscsi_conn *conn);
386 extern void iscsi_conn_queue_work(struct iscsi_conn *conn);
387 
388 #define iscsi_conn_printk(prefix, _c, fmt, a...) \
389 	iscsi_cls_conn_printk(prefix, ((struct iscsi_conn *)_c)->cls_conn, \
390 			      fmt, ##a)
391 
392 /*
393  * pdu and task processing
394  */
395 extern void iscsi_update_cmdsn(struct iscsi_session *, struct iscsi_nopin *);
396 extern void iscsi_prep_data_out_pdu(struct iscsi_task *task,
397 				    struct iscsi_r2t_info *r2t,
398 				    struct iscsi_data *hdr);
399 extern int iscsi_conn_send_pdu(struct iscsi_cls_conn *, struct iscsi_hdr *,
400 				char *, uint32_t);
401 extern int iscsi_complete_pdu(struct iscsi_conn *, struct iscsi_hdr *,
402 			      char *, int);
403 extern int __iscsi_complete_pdu(struct iscsi_conn *, struct iscsi_hdr *,
404 				char *, int);
405 extern int iscsi_verify_itt(struct iscsi_conn *, itt_t);
406 extern struct iscsi_task *iscsi_itt_to_ctask(struct iscsi_conn *, itt_t);
407 extern void iscsi_requeue_task(struct iscsi_task *task);
408 extern void iscsi_put_task(struct iscsi_task *task);
409 extern void __iscsi_get_task(struct iscsi_task *task);
410 
411 /*
412  * generic helpers
413  */
414 extern void iscsi_pool_free(struct iscsi_pool *);
415 extern int iscsi_pool_init(struct iscsi_pool *, int, void ***, int);
416 
417 /*
418  * inline functions to deal with padding.
419  */
420 static inline unsigned int
421 iscsi_padded(unsigned int len)
422 {
423 	return (len + ISCSI_PAD_LEN - 1) & ~(ISCSI_PAD_LEN - 1);
424 }
425 
426 static inline unsigned int
427 iscsi_padding(unsigned int len)
428 {
429 	len &= (ISCSI_PAD_LEN - 1);
430 	if (len)
431 		len = ISCSI_PAD_LEN - len;
432 	return len;
433 }
434 
435 #endif
436