xref: /openbmc/linux/include/scsi/libiscsi.h (revision d0e22329)
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 <linux/kfifo.h>
32 #include <linux/refcount.h>
33 #include <scsi/iscsi_proto.h>
34 #include <scsi/iscsi_if.h>
35 #include <scsi/scsi_transport_iscsi.h>
36 
37 struct scsi_transport_template;
38 struct scsi_host_template;
39 struct scsi_device;
40 struct Scsi_Host;
41 struct scsi_target;
42 struct scsi_cmnd;
43 struct socket;
44 struct iscsi_transport;
45 struct iscsi_cls_session;
46 struct iscsi_cls_conn;
47 struct iscsi_session;
48 struct iscsi_nopin;
49 struct device;
50 
51 #define ISCSI_DEF_XMIT_CMDS_MAX	128	/* must be power of 2 */
52 #define ISCSI_MGMT_CMDS_MAX	15
53 
54 #define ISCSI_DEF_CMD_PER_LUN	32
55 
56 /* Task Mgmt states */
57 enum {
58 	TMF_INITIAL,
59 	TMF_QUEUED,
60 	TMF_SUCCESS,
61 	TMF_FAILED,
62 	TMF_TIMEDOUT,
63 	TMF_NOT_FOUND,
64 };
65 
66 #define ISID_SIZE			6
67 
68 /* Connection suspend "bit" */
69 #define ISCSI_SUSPEND_BIT		1
70 
71 #define ISCSI_ITT_MASK			0x1fff
72 #define ISCSI_TOTAL_CMDS_MAX		4096
73 /* this must be a power of two greater than ISCSI_MGMT_CMDS_MAX */
74 #define ISCSI_TOTAL_CMDS_MIN		16
75 #define ISCSI_AGE_SHIFT			28
76 #define ISCSI_AGE_MASK			0xf
77 
78 #define ISCSI_ADDRESS_BUF_LEN		64
79 
80 enum {
81 	/* this is the maximum possible storage for AHSs */
82 	ISCSI_MAX_AHS_SIZE = sizeof(struct iscsi_ecdb_ahdr) +
83 				sizeof(struct iscsi_rlength_ahdr),
84 	ISCSI_DIGEST_SIZE = sizeof(__u32),
85 };
86 
87 
88 enum {
89 	ISCSI_TASK_FREE,
90 	ISCSI_TASK_COMPLETED,
91 	ISCSI_TASK_PENDING,
92 	ISCSI_TASK_RUNNING,
93 	ISCSI_TASK_ABRT_TMF,		/* aborted due to TMF */
94 	ISCSI_TASK_ABRT_SESS_RECOV,	/* aborted due to session recovery */
95 	ISCSI_TASK_REQUEUE_SCSIQ,	/* qcmd requeueing to scsi-ml */
96 };
97 
98 struct iscsi_r2t_info {
99 	__be32			ttt;		/* copied from R2T */
100 	__be32			exp_statsn;	/* copied from R2T */
101 	uint32_t		data_length;	/* copied from R2T */
102 	uint32_t		data_offset;	/* copied from R2T */
103 	int			data_count;	/* DATA-Out payload progress */
104 	int			datasn;
105 	/* LLDs should set/update these values */
106 	int			sent;		/* R2T sequence progress */
107 };
108 
109 struct iscsi_task {
110 	/*
111 	 * Because LLDs allocate their hdr differently, this is a pointer
112 	 * and length to that storage. It must be setup at session
113 	 * creation time.
114 	 */
115 	struct iscsi_hdr	*hdr;
116 	unsigned short		hdr_max;
117 	unsigned short		hdr_len;	/* accumulated size of hdr used */
118 	/* copied values in case we need to send tmfs */
119 	itt_t			hdr_itt;
120 	__be32			cmdsn;
121 	struct scsi_lun		lun;
122 
123 	int			itt;		/* this ITT */
124 
125 	unsigned		imm_count;	/* imm-data (bytes)   */
126 	/* offset in unsolicited stream (bytes); */
127 	struct iscsi_r2t_info	unsol_r2t;
128 	char			*data;		/* mgmt payload */
129 	unsigned		data_count;
130 	struct scsi_cmnd	*sc;		/* associated SCSI cmd*/
131 	struct iscsi_conn	*conn;		/* used connection    */
132 
133 	/* data processing tracking */
134 	unsigned long		last_xfer;
135 	unsigned long		last_timeout;
136 	bool			have_checked_conn;
137 
138 	/* T10 protection information */
139 	bool			protected;
140 
141 	/* state set/tested under session->lock */
142 	int			state;
143 	refcount_t		refcount;
144 	struct list_head	running;	/* running cmd list */
145 	void			*dd_data;	/* driver/transport data */
146 };
147 
148 static inline int iscsi_task_has_unsol_data(struct iscsi_task *task)
149 {
150 	return task->unsol_r2t.data_length > task->unsol_r2t.sent;
151 }
152 
153 static inline void* iscsi_next_hdr(struct iscsi_task *task)
154 {
155 	return (void*)task->hdr + task->hdr_len;
156 }
157 
158 /* Connection's states */
159 enum {
160 	ISCSI_CONN_INITIAL_STAGE,
161 	ISCSI_CONN_STARTED,
162 	ISCSI_CONN_STOPPED,
163 	ISCSI_CONN_CLEANUP_WAIT,
164 };
165 
166 struct iscsi_conn {
167 	struct iscsi_cls_conn	*cls_conn;	/* ptr to class connection */
168 	void			*dd_data;	/* iscsi_transport data */
169 	struct iscsi_session	*session;	/* parent session */
170 	/*
171 	 * conn_stop() flag: stop to recover, stop to terminate
172 	 */
173         int			stop_stage;
174 	struct timer_list	transport_timer;
175 	unsigned long		last_recv;
176 	unsigned long		last_ping;
177 	int			ping_timeout;
178 	int			recv_timeout;
179 	struct iscsi_task 	*ping_task;
180 
181 	/* iSCSI connection-wide sequencing */
182 	uint32_t		exp_statsn;
183 	uint32_t		statsn;
184 
185 	/* control data */
186 	int			id;		/* CID */
187 	int			c_stage;	/* connection state */
188 	/*
189 	 * Preallocated buffer for pdus that have data but do not
190 	 * originate from scsi-ml. We never have two pdus using the
191 	 * buffer at the same time. It is only allocated to
192 	 * the default max recv size because the pdus we support
193 	 * should always fit in this buffer
194 	 */
195 	char			*data;
196 	struct iscsi_task 	*login_task;	/* mtask used for login/text */
197 	struct iscsi_task	*task;		/* xmit task in progress */
198 
199 	/* xmit */
200 	spinlock_t		taskqueuelock;  /* protects the next three lists */
201 	struct list_head	mgmtqueue;	/* mgmt (control) xmit queue */
202 	struct list_head	cmdqueue;	/* data-path cmd queue */
203 	struct list_head	requeue;	/* tasks needing another run */
204 	struct work_struct	xmitwork;	/* per-conn. xmit workqueue */
205 	unsigned long		suspend_tx;	/* suspend Tx */
206 	unsigned long		suspend_rx;	/* suspend Rx */
207 
208 	/* abort */
209 	wait_queue_head_t	ehwait;		/* used in eh_abort() */
210 	struct iscsi_tm		tmhdr;
211 	struct timer_list	tmf_timer;
212 	int			tmf_state;	/* see TMF_INITIAL, etc.*/
213 
214 	/* negotiated params */
215 	unsigned		max_recv_dlength; /* initiator_max_recv_dsl*/
216 	unsigned		max_xmit_dlength; /* target_max_recv_dsl */
217 	int			hdrdgst_en;
218 	int			datadgst_en;
219 	int			ifmarker_en;
220 	int			ofmarker_en;
221 	/* values userspace uses to id a conn */
222 	int			persistent_port;
223 	char			*persistent_address;
224 
225 	unsigned		max_segment_size;
226 	unsigned		tcp_xmit_wsf;
227 	unsigned		tcp_recv_wsf;
228 	uint16_t		keepalive_tmo;
229 	uint16_t		local_port;
230 	uint8_t			tcp_timestamp_stat;
231 	uint8_t			tcp_nagle_disable;
232 	uint8_t			tcp_wsf_disable;
233 	uint8_t			tcp_timer_scale;
234 	uint8_t			tcp_timestamp_en;
235 	uint8_t			fragment_disable;
236 	uint8_t			ipv4_tos;
237 	uint8_t			ipv6_traffic_class;
238 	uint8_t			ipv6_flow_label;
239 	uint8_t			is_fw_assigned_ipv6;
240 	char			*local_ipaddr;
241 
242 	/* MIB-statistics */
243 	uint64_t		txdata_octets;
244 	uint64_t		rxdata_octets;
245 	uint32_t		scsicmd_pdus_cnt;
246 	uint32_t		dataout_pdus_cnt;
247 	uint32_t		scsirsp_pdus_cnt;
248 	uint32_t		datain_pdus_cnt;
249 	uint32_t		r2t_pdus_cnt;
250 	uint32_t		tmfcmd_pdus_cnt;
251 	int32_t			tmfrsp_pdus_cnt;
252 
253 	/* custom statistics */
254 	uint32_t		eh_abort_cnt;
255 	uint32_t		fmr_unalign_cnt;
256 };
257 
258 struct iscsi_pool {
259 	struct kfifo		queue;		/* FIFO Queue */
260 	void			**pool;		/* Pool of elements */
261 	int			max;		/* Max number of elements */
262 };
263 
264 /* Session's states */
265 enum {
266 	ISCSI_STATE_FREE = 1,
267 	ISCSI_STATE_LOGGED_IN,
268 	ISCSI_STATE_FAILED,
269 	ISCSI_STATE_TERMINATE,
270 	ISCSI_STATE_IN_RECOVERY,
271 	ISCSI_STATE_RECOVERY_FAILED,
272 	ISCSI_STATE_LOGGING_OUT,
273 };
274 
275 struct iscsi_session {
276 	struct iscsi_cls_session *cls_session;
277 	/*
278 	 * Syncs up the scsi eh thread with the iscsi eh thread when sending
279 	 * task management functions. This must be taken before the session
280 	 * and recv lock.
281 	 */
282 	struct mutex		eh_mutex;
283 
284 	/* iSCSI session-wide sequencing */
285 	uint32_t		cmdsn;
286 	uint32_t		exp_cmdsn;
287 	uint32_t		max_cmdsn;
288 
289 	/* This tracks the reqs queued into the initiator */
290 	uint32_t		queued_cmdsn;
291 
292 	/* configuration */
293 	int			abort_timeout;
294 	int			lu_reset_timeout;
295 	int			tgt_reset_timeout;
296 	int			initial_r2t_en;
297 	unsigned short		max_r2t;
298 	int			imm_data_en;
299 	unsigned		first_burst;
300 	unsigned		max_burst;
301 	int			time2wait;
302 	int			time2retain;
303 	int			pdu_inorder_en;
304 	int			dataseq_inorder_en;
305 	int			erl;
306 	int			fast_abort;
307 	int			tpgt;
308 	char			*username;
309 	char			*username_in;
310 	char			*password;
311 	char			*password_in;
312 	char			*targetname;
313 	char			*targetalias;
314 	char			*ifacename;
315 	char			*initiatorname;
316 	char			*boot_root;
317 	char			*boot_nic;
318 	char			*boot_target;
319 	char			*portal_type;
320 	char			*discovery_parent_type;
321 	uint16_t		discovery_parent_idx;
322 	uint16_t		def_taskmgmt_tmo;
323 	uint16_t		tsid;
324 	uint8_t			auto_snd_tgt_disable;
325 	uint8_t			discovery_sess;
326 	uint8_t			chap_auth_en;
327 	uint8_t			discovery_logout_en;
328 	uint8_t			bidi_chap_en;
329 	uint8_t			discovery_auth_optional;
330 	uint8_t			isid[ISID_SIZE];
331 
332 	/* control data */
333 	struct iscsi_transport	*tt;
334 	struct Scsi_Host	*host;
335 	struct iscsi_conn	*leadconn;	/* leading connection */
336 	/* Between the forward and the backward locks exists a strict locking
337 	 * hierarchy. The mutual exclusion zone protected by the forward lock
338 	 * can enclose the mutual exclusion zone protected by the backward lock
339 	 * but not vice versa.
340 	 */
341 	spinlock_t		frwd_lock;	/* protects session state, *
342 						 * cmdsn, queued_cmdsn     *
343 						 * session resources:      *
344 						 * - cmdpool kfifo_out ,   *
345 						 * - mgmtpool,		   */
346 	spinlock_t		back_lock;	/* protects cmdsn_exp      *
347 						 * cmdsn_max,              *
348 						 * cmdpool kfifo_in        */
349 	int			state;		/* session state           */
350 	int			age;		/* counts session re-opens */
351 
352 	int			scsi_cmds_max; 	/* max scsi commands */
353 	int			cmds_max;	/* size of cmds array */
354 	struct iscsi_task	**cmds;		/* Original Cmds arr */
355 	struct iscsi_pool	cmdpool;	/* PDU's pool */
356 	void			*dd_data;	/* LLD private data */
357 };
358 
359 enum {
360 	ISCSI_HOST_SETUP,
361 	ISCSI_HOST_REMOVED,
362 };
363 
364 struct iscsi_host {
365 	char			*initiatorname;
366 	/* hw address or netdev iscsi connection is bound to */
367 	char			*hwaddress;
368 	char			*netdev;
369 
370 	wait_queue_head_t	session_removal_wq;
371 	/* protects sessions and state */
372 	spinlock_t		lock;
373 	int			num_sessions;
374 	int			state;
375 
376 	struct workqueue_struct	*workq;
377 	char			workq_name[20];
378 };
379 
380 /*
381  * scsi host template
382  */
383 extern int iscsi_eh_abort(struct scsi_cmnd *sc);
384 extern int iscsi_eh_recover_target(struct scsi_cmnd *sc);
385 extern int iscsi_eh_session_reset(struct scsi_cmnd *sc);
386 extern int iscsi_eh_device_reset(struct scsi_cmnd *sc);
387 extern int iscsi_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *sc);
388 extern enum blk_eh_timer_return iscsi_eh_cmd_timed_out(struct scsi_cmnd *sc);
389 
390 /*
391  * iSCSI host helpers.
392  */
393 #define iscsi_host_priv(_shost) \
394 	(shost_priv(_shost) + sizeof(struct iscsi_host))
395 
396 extern int iscsi_host_set_param(struct Scsi_Host *shost,
397 				enum iscsi_host_param param, char *buf,
398 				int buflen);
399 extern int iscsi_host_get_param(struct Scsi_Host *shost,
400 				enum iscsi_host_param param, char *buf);
401 extern int iscsi_host_add(struct Scsi_Host *shost, struct device *pdev);
402 extern struct Scsi_Host *iscsi_host_alloc(struct scsi_host_template *sht,
403 					  int dd_data_size,
404 					  bool xmit_can_sleep);
405 extern void iscsi_host_remove(struct Scsi_Host *shost);
406 extern void iscsi_host_free(struct Scsi_Host *shost);
407 extern int iscsi_target_alloc(struct scsi_target *starget);
408 
409 /*
410  * session management
411  */
412 extern struct iscsi_cls_session *
413 iscsi_session_setup(struct iscsi_transport *, struct Scsi_Host *shost,
414 		    uint16_t, int, int, uint32_t, unsigned int);
415 extern void iscsi_session_teardown(struct iscsi_cls_session *);
416 extern void iscsi_session_recovery_timedout(struct iscsi_cls_session *);
417 extern int iscsi_set_param(struct iscsi_cls_conn *cls_conn,
418 			   enum iscsi_param param, char *buf, int buflen);
419 extern int iscsi_session_get_param(struct iscsi_cls_session *cls_session,
420 				   enum iscsi_param param, char *buf);
421 
422 #define iscsi_session_printk(prefix, _sess, fmt, a...)	\
423 	iscsi_cls_session_printk(prefix, _sess->cls_session, fmt, ##a)
424 
425 /*
426  * connection management
427  */
428 extern struct iscsi_cls_conn *iscsi_conn_setup(struct iscsi_cls_session *,
429 					       int, uint32_t);
430 extern void iscsi_conn_teardown(struct iscsi_cls_conn *);
431 extern int iscsi_conn_start(struct iscsi_cls_conn *);
432 extern void iscsi_conn_stop(struct iscsi_cls_conn *, int);
433 extern int iscsi_conn_bind(struct iscsi_cls_session *, struct iscsi_cls_conn *,
434 			   int);
435 extern void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err);
436 extern void iscsi_session_failure(struct iscsi_session *session,
437 				  enum iscsi_err err);
438 extern int iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
439 				enum iscsi_param param, char *buf);
440 extern int iscsi_conn_get_addr_param(struct sockaddr_storage *addr,
441 				     enum iscsi_param param, char *buf);
442 extern void iscsi_suspend_tx(struct iscsi_conn *conn);
443 extern void iscsi_suspend_queue(struct iscsi_conn *conn);
444 extern void iscsi_conn_queue_work(struct iscsi_conn *conn);
445 
446 #define iscsi_conn_printk(prefix, _c, fmt, a...) \
447 	iscsi_cls_conn_printk(prefix, ((struct iscsi_conn *)_c)->cls_conn, \
448 			      fmt, ##a)
449 
450 /*
451  * pdu and task processing
452  */
453 extern void iscsi_update_cmdsn(struct iscsi_session *, struct iscsi_nopin *);
454 extern void iscsi_prep_data_out_pdu(struct iscsi_task *task,
455 				    struct iscsi_r2t_info *r2t,
456 				    struct iscsi_data *hdr);
457 extern int iscsi_conn_send_pdu(struct iscsi_cls_conn *, struct iscsi_hdr *,
458 				char *, uint32_t);
459 extern int iscsi_complete_pdu(struct iscsi_conn *, struct iscsi_hdr *,
460 			      char *, int);
461 extern int __iscsi_complete_pdu(struct iscsi_conn *, struct iscsi_hdr *,
462 				char *, int);
463 extern int iscsi_verify_itt(struct iscsi_conn *, itt_t);
464 extern struct iscsi_task *iscsi_itt_to_ctask(struct iscsi_conn *, itt_t);
465 extern struct iscsi_task *iscsi_itt_to_task(struct iscsi_conn *, itt_t);
466 extern void iscsi_requeue_task(struct iscsi_task *task);
467 extern void iscsi_put_task(struct iscsi_task *task);
468 extern void __iscsi_put_task(struct iscsi_task *task);
469 extern void __iscsi_get_task(struct iscsi_task *task);
470 extern void iscsi_complete_scsi_task(struct iscsi_task *task,
471 				     uint32_t exp_cmdsn, uint32_t max_cmdsn);
472 
473 /*
474  * generic helpers
475  */
476 extern void iscsi_pool_free(struct iscsi_pool *);
477 extern int iscsi_pool_init(struct iscsi_pool *, int, void ***, int);
478 extern int iscsi_switch_str_param(char **, char *);
479 
480 /*
481  * inline functions to deal with padding.
482  */
483 static inline unsigned int
484 iscsi_padded(unsigned int len)
485 {
486 	return (len + ISCSI_PAD_LEN - 1) & ~(ISCSI_PAD_LEN - 1);
487 }
488 
489 static inline unsigned int
490 iscsi_padding(unsigned int len)
491 {
492 	len &= (ISCSI_PAD_LEN - 1);
493 	if (len)
494 		len = ISCSI_PAD_LEN - len;
495 	return len;
496 }
497 
498 #endif
499