xref: /openbmc/linux/include/scsi/libiscsi.h (revision fd589a8f)
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_target;
40 struct scsi_cmnd;
41 struct socket;
42 struct iscsi_transport;
43 struct iscsi_cls_session;
44 struct iscsi_cls_conn;
45 struct iscsi_session;
46 struct iscsi_nopin;
47 struct device;
48 
49 #define ISCSI_DEF_XMIT_CMDS_MAX	128	/* must be power of 2 */
50 #define ISCSI_MGMT_CMDS_MAX	15
51 
52 #define ISCSI_DEF_CMD_PER_LUN	32
53 
54 /* Task Mgmt states */
55 enum {
56 	TMF_INITIAL,
57 	TMF_QUEUED,
58 	TMF_SUCCESS,
59 	TMF_FAILED,
60 	TMF_TIMEDOUT,
61 	TMF_NOT_FOUND,
62 };
63 
64 /* Connection suspend "bit" */
65 #define ISCSI_SUSPEND_BIT		1
66 
67 #define ISCSI_ITT_MASK			0x1fff
68 #define ISCSI_TOTAL_CMDS_MAX		4096
69 /* this must be a power of two greater than ISCSI_MGMT_CMDS_MAX */
70 #define ISCSI_TOTAL_CMDS_MIN		16
71 #define ISCSI_AGE_SHIFT			28
72 #define ISCSI_AGE_MASK			0xf
73 
74 #define ISCSI_ADDRESS_BUF_LEN		64
75 
76 enum {
77 	/* this is the maximum possible storage for AHSs */
78 	ISCSI_MAX_AHS_SIZE = sizeof(struct iscsi_ecdb_ahdr) +
79 				sizeof(struct iscsi_rlength_ahdr),
80 	ISCSI_DIGEST_SIZE = sizeof(__u32),
81 };
82 
83 
84 enum {
85 	ISCSI_TASK_FREE,
86 	ISCSI_TASK_COMPLETED,
87 	ISCSI_TASK_PENDING,
88 	ISCSI_TASK_RUNNING,
89 	ISCSI_TASK_ABRT_TMF,		/* aborted due to TMF */
90 	ISCSI_TASK_ABRT_SESS_RECOV,	/* aborted due to session recovery */
91 };
92 
93 struct iscsi_r2t_info {
94 	__be32			ttt;		/* copied from R2T */
95 	__be32			exp_statsn;	/* copied from R2T */
96 	uint32_t		data_length;	/* copied from R2T */
97 	uint32_t		data_offset;	/* copied from R2T */
98 	int			data_count;	/* DATA-Out payload progress */
99 	int			datasn;
100 	/* LLDs should set/update these values */
101 	int			sent;		/* R2T sequence progress */
102 };
103 
104 struct iscsi_task {
105 	/*
106 	 * Because LLDs allocate their hdr differently, this is a pointer
107 	 * and length to that storage. It must be setup at session
108 	 * creation time.
109 	 */
110 	struct iscsi_hdr	*hdr;
111 	unsigned short		hdr_max;
112 	unsigned short		hdr_len;	/* accumulated size of hdr used */
113 	/* copied values in case we need to send tmfs */
114 	itt_t			hdr_itt;
115 	__be32			cmdsn;
116 	uint8_t			lun[8];
117 
118 	int			itt;		/* this ITT */
119 
120 	unsigned		imm_count;	/* imm-data (bytes)   */
121 	/* offset in unsolicited stream (bytes); */
122 	struct iscsi_r2t_info	unsol_r2t;
123 	char			*data;		/* mgmt payload */
124 	unsigned		data_count;
125 	struct scsi_cmnd	*sc;		/* associated SCSI cmd*/
126 	struct iscsi_conn	*conn;		/* used connection    */
127 
128 	/* data processing tracking */
129 	unsigned long		last_xfer;
130 	unsigned long		last_timeout;
131 	bool			have_checked_conn;
132 	/* state set/tested under session->lock */
133 	int			state;
134 	atomic_t		refcount;
135 	struct list_head	running;	/* running cmd list */
136 	void			*dd_data;	/* driver/transport data */
137 };
138 
139 static inline int iscsi_task_has_unsol_data(struct iscsi_task *task)
140 {
141 	return task->unsol_r2t.data_length > task->unsol_r2t.sent;
142 }
143 
144 static inline void* iscsi_next_hdr(struct iscsi_task *task)
145 {
146 	return (void*)task->hdr + task->hdr_len;
147 }
148 
149 /* Connection's states */
150 enum {
151 	ISCSI_CONN_INITIAL_STAGE,
152 	ISCSI_CONN_STARTED,
153 	ISCSI_CONN_STOPPED,
154 	ISCSI_CONN_CLEANUP_WAIT,
155 };
156 
157 struct iscsi_conn {
158 	struct iscsi_cls_conn	*cls_conn;	/* ptr to class connection */
159 	void			*dd_data;	/* iscsi_transport data */
160 	struct iscsi_session	*session;	/* parent session */
161 	/*
162 	 * conn_stop() flag: stop to recover, stop to terminate
163 	 */
164         int			stop_stage;
165 	struct timer_list	transport_timer;
166 	unsigned long		last_recv;
167 	unsigned long		last_ping;
168 	int			ping_timeout;
169 	int			recv_timeout;
170 	struct iscsi_task 	*ping_task;
171 
172 	/* iSCSI connection-wide sequencing */
173 	uint32_t		exp_statsn;
174 
175 	/* control data */
176 	int			id;		/* CID */
177 	int			c_stage;	/* connection state */
178 	/*
179 	 * Preallocated buffer for pdus that have data but do not
180 	 * originate from scsi-ml. We never have two pdus using the
181 	 * buffer at the same time. It is only allocated to
182 	 * the default max recv size because the pdus we support
183 	 * should always fit in this buffer
184 	 */
185 	char			*data;
186 	struct iscsi_task 	*login_task;	/* mtask used for login/text */
187 	struct iscsi_task	*task;		/* xmit task in progress */
188 
189 	/* xmit */
190 	struct list_head	mgmtqueue;	/* mgmt (control) xmit queue */
191 	struct list_head	cmdqueue;	/* data-path cmd queue */
192 	struct list_head	requeue;	/* tasks needing another run */
193 	struct work_struct	xmitwork;	/* per-conn. xmit workqueue */
194 	unsigned long		suspend_tx;	/* suspend Tx */
195 	unsigned long		suspend_rx;	/* suspend Rx */
196 
197 	/* abort */
198 	wait_queue_head_t	ehwait;		/* used in eh_abort() */
199 	struct iscsi_tm		tmhdr;
200 	struct timer_list	tmf_timer;
201 	int			tmf_state;	/* see TMF_INITIAL, etc.*/
202 
203 	/* negotiated params */
204 	unsigned		max_recv_dlength; /* initiator_max_recv_dsl*/
205 	unsigned		max_xmit_dlength; /* target_max_recv_dsl */
206 	int			hdrdgst_en;
207 	int			datadgst_en;
208 	int			ifmarker_en;
209 	int			ofmarker_en;
210 	/* values userspace uses to id a conn */
211 	int			persistent_port;
212 	char			*persistent_address;
213 	/* remote portal currently connected to */
214 	int			portal_port;
215 	char			portal_address[ISCSI_ADDRESS_BUF_LEN];
216 
217 	/* MIB-statistics */
218 	uint64_t		txdata_octets;
219 	uint64_t		rxdata_octets;
220 	uint32_t		scsicmd_pdus_cnt;
221 	uint32_t		dataout_pdus_cnt;
222 	uint32_t		scsirsp_pdus_cnt;
223 	uint32_t		datain_pdus_cnt;
224 	uint32_t		r2t_pdus_cnt;
225 	uint32_t		tmfcmd_pdus_cnt;
226 	int32_t			tmfrsp_pdus_cnt;
227 
228 	/* custom statistics */
229 	uint32_t		eh_abort_cnt;
230 	uint32_t		fmr_unalign_cnt;
231 };
232 
233 struct iscsi_pool {
234 	struct kfifo		*queue;		/* FIFO Queue */
235 	void			**pool;		/* Pool of elements */
236 	int			max;		/* Max number of elements */
237 };
238 
239 /* Session's states */
240 enum {
241 	ISCSI_STATE_FREE = 1,
242 	ISCSI_STATE_LOGGED_IN,
243 	ISCSI_STATE_FAILED,
244 	ISCSI_STATE_TERMINATE,
245 	ISCSI_STATE_IN_RECOVERY,
246 	ISCSI_STATE_RECOVERY_FAILED,
247 	ISCSI_STATE_LOGGING_OUT,
248 };
249 
250 struct iscsi_session {
251 	struct iscsi_cls_session *cls_session;
252 	/*
253 	 * Syncs up the scsi eh thread with the iscsi eh thread when sending
254 	 * task management functions. This must be taken before the session
255 	 * and recv lock.
256 	 */
257 	struct mutex		eh_mutex;
258 
259 	/* iSCSI session-wide sequencing */
260 	uint32_t		cmdsn;
261 	uint32_t		exp_cmdsn;
262 	uint32_t		max_cmdsn;
263 
264 	/* This tracks the reqs queued into the initiator */
265 	uint32_t		queued_cmdsn;
266 
267 	/* configuration */
268 	int			abort_timeout;
269 	int			lu_reset_timeout;
270 	int			initial_r2t_en;
271 	unsigned		max_r2t;
272 	int			imm_data_en;
273 	unsigned		first_burst;
274 	unsigned		max_burst;
275 	int			time2wait;
276 	int			time2retain;
277 	int			pdu_inorder_en;
278 	int			dataseq_inorder_en;
279 	int			erl;
280 	int			fast_abort;
281 	int			tpgt;
282 	char			*username;
283 	char			*username_in;
284 	char			*password;
285 	char			*password_in;
286 	char			*targetname;
287 	char			*ifacename;
288 	char			*initiatorname;
289 	/* control data */
290 	struct iscsi_transport	*tt;
291 	struct Scsi_Host	*host;
292 	struct iscsi_conn	*leadconn;	/* leading connection */
293 	spinlock_t		lock;		/* protects session state, *
294 						 * sequence numbers,       *
295 						 * session resources:      *
296 						 * - cmdpool,		   *
297 						 * - mgmtpool,		   *
298 						 * - r2tpool		   */
299 	int			state;		/* session state           */
300 	int			age;		/* counts session re-opens */
301 
302 	int			scsi_cmds_max; 	/* max scsi commands */
303 	int			cmds_max;	/* size of cmds array */
304 	struct iscsi_task	**cmds;		/* Original Cmds arr */
305 	struct iscsi_pool	cmdpool;	/* PDU's pool */
306 };
307 
308 enum {
309 	ISCSI_HOST_SETUP,
310 	ISCSI_HOST_REMOVED,
311 };
312 
313 struct iscsi_host {
314 	char			*initiatorname;
315 	/* hw address or netdev iscsi connection is bound to */
316 	char			*hwaddress;
317 	char			*netdev;
318 	/* local address */
319 	int			local_port;
320 	char			local_address[ISCSI_ADDRESS_BUF_LEN];
321 
322 	wait_queue_head_t	session_removal_wq;
323 	/* protects sessions and state */
324 	spinlock_t		lock;
325 	int			num_sessions;
326 	int			state;
327 
328 	struct workqueue_struct	*workq;
329 	char			workq_name[20];
330 };
331 
332 /*
333  * scsi host template
334  */
335 extern int iscsi_change_queue_depth(struct scsi_device *sdev, int depth);
336 extern int iscsi_eh_abort(struct scsi_cmnd *sc);
337 extern int iscsi_eh_target_reset(struct scsi_cmnd *sc);
338 extern int iscsi_eh_device_reset(struct scsi_cmnd *sc);
339 extern int iscsi_queuecommand(struct scsi_cmnd *sc,
340 			      void (*done)(struct scsi_cmnd *));
341 
342 /*
343  * iSCSI host helpers.
344  */
345 #define iscsi_host_priv(_shost) \
346 	(shost_priv(_shost) + sizeof(struct iscsi_host))
347 
348 extern int iscsi_host_set_param(struct Scsi_Host *shost,
349 				enum iscsi_host_param param, char *buf,
350 				int buflen);
351 extern int iscsi_host_get_param(struct Scsi_Host *shost,
352 				enum iscsi_host_param param, char *buf);
353 extern int iscsi_host_add(struct Scsi_Host *shost, struct device *pdev);
354 extern struct Scsi_Host *iscsi_host_alloc(struct scsi_host_template *sht,
355 					  int dd_data_size,
356 					  bool xmit_can_sleep);
357 extern void iscsi_host_remove(struct Scsi_Host *shost);
358 extern void iscsi_host_free(struct Scsi_Host *shost);
359 extern int iscsi_target_alloc(struct scsi_target *starget);
360 
361 /*
362  * session management
363  */
364 extern struct iscsi_cls_session *
365 iscsi_session_setup(struct iscsi_transport *, struct Scsi_Host *shost,
366 		    uint16_t, int, uint32_t, unsigned int);
367 extern void iscsi_session_teardown(struct iscsi_cls_session *);
368 extern void iscsi_session_recovery_timedout(struct iscsi_cls_session *);
369 extern int iscsi_set_param(struct iscsi_cls_conn *cls_conn,
370 			   enum iscsi_param param, char *buf, int buflen);
371 extern int iscsi_session_get_param(struct iscsi_cls_session *cls_session,
372 				   enum iscsi_param param, char *buf);
373 
374 #define iscsi_session_printk(prefix, _sess, fmt, a...)	\
375 	iscsi_cls_session_printk(prefix, _sess->cls_session, fmt, ##a)
376 
377 /*
378  * connection management
379  */
380 extern struct iscsi_cls_conn *iscsi_conn_setup(struct iscsi_cls_session *,
381 					       int, uint32_t);
382 extern void iscsi_conn_teardown(struct iscsi_cls_conn *);
383 extern int iscsi_conn_start(struct iscsi_cls_conn *);
384 extern void iscsi_conn_stop(struct iscsi_cls_conn *, int);
385 extern int iscsi_conn_bind(struct iscsi_cls_session *, struct iscsi_cls_conn *,
386 			   int);
387 extern void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err);
388 extern void iscsi_session_failure(struct iscsi_session *session,
389 				  enum iscsi_err err);
390 extern int iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
391 				enum iscsi_param param, char *buf);
392 extern void iscsi_suspend_tx(struct iscsi_conn *conn);
393 extern void iscsi_suspend_queue(struct iscsi_conn *conn);
394 extern void iscsi_conn_queue_work(struct iscsi_conn *conn);
395 
396 #define iscsi_conn_printk(prefix, _c, fmt, a...) \
397 	iscsi_cls_conn_printk(prefix, ((struct iscsi_conn *)_c)->cls_conn, \
398 			      fmt, ##a)
399 
400 /*
401  * pdu and task processing
402  */
403 extern void iscsi_update_cmdsn(struct iscsi_session *, struct iscsi_nopin *);
404 extern void iscsi_prep_data_out_pdu(struct iscsi_task *task,
405 				    struct iscsi_r2t_info *r2t,
406 				    struct iscsi_data *hdr);
407 extern int iscsi_conn_send_pdu(struct iscsi_cls_conn *, struct iscsi_hdr *,
408 				char *, uint32_t);
409 extern int iscsi_complete_pdu(struct iscsi_conn *, struct iscsi_hdr *,
410 			      char *, int);
411 extern int __iscsi_complete_pdu(struct iscsi_conn *, struct iscsi_hdr *,
412 				char *, int);
413 extern int iscsi_verify_itt(struct iscsi_conn *, itt_t);
414 extern struct iscsi_task *iscsi_itt_to_ctask(struct iscsi_conn *, itt_t);
415 extern struct iscsi_task *iscsi_itt_to_task(struct iscsi_conn *, itt_t);
416 extern void iscsi_requeue_task(struct iscsi_task *task);
417 extern void iscsi_put_task(struct iscsi_task *task);
418 extern void __iscsi_get_task(struct iscsi_task *task);
419 extern void iscsi_complete_scsi_task(struct iscsi_task *task,
420 				     uint32_t exp_cmdsn, uint32_t max_cmdsn);
421 
422 /*
423  * generic helpers
424  */
425 extern void iscsi_pool_free(struct iscsi_pool *);
426 extern int iscsi_pool_init(struct iscsi_pool *, int, void ***, int);
427 
428 /*
429  * inline functions to deal with padding.
430  */
431 static inline unsigned int
432 iscsi_padded(unsigned int len)
433 {
434 	return (len + ISCSI_PAD_LEN - 1) & ~(ISCSI_PAD_LEN - 1);
435 }
436 
437 static inline unsigned int
438 iscsi_padding(unsigned int len)
439 {
440 	len &= (ISCSI_PAD_LEN - 1);
441 	if (len)
442 		len = ISCSI_PAD_LEN - len;
443 	return len;
444 }
445 
446 #endif
447