xref: /linux/include/scsi/libiscsi.h (revision 93d90ad708b8da6efc0e487b66111aa9db7f70c7)
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 <scsi/iscsi_proto.h>
33 #include <scsi/iscsi_if.h>
34 #include <scsi/scsi_transport_iscsi.h>
35 
36 struct scsi_transport_template;
37 struct scsi_host_template;
38 struct scsi_device;
39 struct Scsi_Host;
40 struct scsi_target;
41 struct scsi_cmnd;
42 struct socket;
43 struct iscsi_transport;
44 struct iscsi_cls_session;
45 struct iscsi_cls_conn;
46 struct iscsi_session;
47 struct iscsi_nopin;
48 struct device;
49 
50 #define ISCSI_DEF_XMIT_CMDS_MAX	128	/* must be power of 2 */
51 #define ISCSI_MGMT_CMDS_MAX	15
52 
53 #define ISCSI_DEF_CMD_PER_LUN	32
54 
55 /* Task Mgmt states */
56 enum {
57 	TMF_INITIAL,
58 	TMF_QUEUED,
59 	TMF_SUCCESS,
60 	TMF_FAILED,
61 	TMF_TIMEDOUT,
62 	TMF_NOT_FOUND,
63 };
64 
65 #define ISID_SIZE			6
66 
67 /* Connection suspend "bit" */
68 #define ISCSI_SUSPEND_BIT		1
69 
70 #define ISCSI_ITT_MASK			0x1fff
71 #define ISCSI_TOTAL_CMDS_MAX		4096
72 /* this must be a power of two greater than ISCSI_MGMT_CMDS_MAX */
73 #define ISCSI_TOTAL_CMDS_MIN		16
74 #define ISCSI_AGE_SHIFT			28
75 #define ISCSI_AGE_MASK			0xf
76 
77 #define ISCSI_ADDRESS_BUF_LEN		64
78 
79 enum {
80 	/* this is the maximum possible storage for AHSs */
81 	ISCSI_MAX_AHS_SIZE = sizeof(struct iscsi_ecdb_ahdr) +
82 				sizeof(struct iscsi_rlength_ahdr),
83 	ISCSI_DIGEST_SIZE = sizeof(__u32),
84 };
85 
86 
87 enum {
88 	ISCSI_TASK_FREE,
89 	ISCSI_TASK_COMPLETED,
90 	ISCSI_TASK_PENDING,
91 	ISCSI_TASK_RUNNING,
92 	ISCSI_TASK_ABRT_TMF,		/* aborted due to TMF */
93 	ISCSI_TASK_ABRT_SESS_RECOV,	/* aborted due to session recovery */
94 	ISCSI_TASK_REQUEUE_SCSIQ,	/* qcmd requeueing to scsi-ml */
95 };
96 
97 struct iscsi_r2t_info {
98 	__be32			ttt;		/* copied from R2T */
99 	__be32			exp_statsn;	/* copied from R2T */
100 	uint32_t		data_length;	/* copied from R2T */
101 	uint32_t		data_offset;	/* copied from R2T */
102 	int			data_count;	/* DATA-Out payload progress */
103 	int			datasn;
104 	/* LLDs should set/update these values */
105 	int			sent;		/* R2T sequence progress */
106 };
107 
108 struct iscsi_task {
109 	/*
110 	 * Because LLDs allocate their hdr differently, this is a pointer
111 	 * and length to that storage. It must be setup at session
112 	 * creation time.
113 	 */
114 	struct iscsi_hdr	*hdr;
115 	unsigned short		hdr_max;
116 	unsigned short		hdr_len;	/* accumulated size of hdr used */
117 	/* copied values in case we need to send tmfs */
118 	itt_t			hdr_itt;
119 	__be32			cmdsn;
120 	struct scsi_lun		lun;
121 
122 	int			itt;		/* this ITT */
123 
124 	unsigned		imm_count;	/* imm-data (bytes)   */
125 	/* offset in unsolicited stream (bytes); */
126 	struct iscsi_r2t_info	unsol_r2t;
127 	char			*data;		/* mgmt payload */
128 	unsigned		data_count;
129 	struct scsi_cmnd	*sc;		/* associated SCSI cmd*/
130 	struct iscsi_conn	*conn;		/* used connection    */
131 
132 	/* data processing tracking */
133 	unsigned long		last_xfer;
134 	unsigned long		last_timeout;
135 	bool			have_checked_conn;
136 
137 	/* T10 protection information */
138 	bool			protected;
139 
140 	/* state set/tested under session->lock */
141 	int			state;
142 	atomic_t		refcount;
143 	struct list_head	running;	/* running cmd list */
144 	void			*dd_data;	/* driver/transport data */
145 };
146 
147 static inline int iscsi_task_has_unsol_data(struct iscsi_task *task)
148 {
149 	return task->unsol_r2t.data_length > task->unsol_r2t.sent;
150 }
151 
152 static inline void* iscsi_next_hdr(struct iscsi_task *task)
153 {
154 	return (void*)task->hdr + task->hdr_len;
155 }
156 
157 /* Connection's states */
158 enum {
159 	ISCSI_CONN_INITIAL_STAGE,
160 	ISCSI_CONN_STARTED,
161 	ISCSI_CONN_STOPPED,
162 	ISCSI_CONN_CLEANUP_WAIT,
163 };
164 
165 struct iscsi_conn {
166 	struct iscsi_cls_conn	*cls_conn;	/* ptr to class connection */
167 	void			*dd_data;	/* iscsi_transport data */
168 	struct iscsi_session	*session;	/* parent session */
169 	/*
170 	 * conn_stop() flag: stop to recover, stop to terminate
171 	 */
172         int			stop_stage;
173 	struct timer_list	transport_timer;
174 	unsigned long		last_recv;
175 	unsigned long		last_ping;
176 	int			ping_timeout;
177 	int			recv_timeout;
178 	struct iscsi_task 	*ping_task;
179 
180 	/* iSCSI connection-wide sequencing */
181 	uint32_t		exp_statsn;
182 	uint32_t		statsn;
183 
184 	/* control data */
185 	int			id;		/* CID */
186 	int			c_stage;	/* connection state */
187 	/*
188 	 * Preallocated buffer for pdus that have data but do not
189 	 * originate from scsi-ml. We never have two pdus using the
190 	 * buffer at the same time. It is only allocated to
191 	 * the default max recv size because the pdus we support
192 	 * should always fit in this buffer
193 	 */
194 	char			*data;
195 	struct iscsi_task 	*login_task;	/* mtask used for login/text */
196 	struct iscsi_task	*task;		/* xmit task in progress */
197 
198 	/* xmit */
199 	struct list_head	mgmtqueue;	/* mgmt (control) xmit queue */
200 	struct list_head	cmdqueue;	/* data-path cmd queue */
201 	struct list_head	requeue;	/* tasks needing another run */
202 	struct work_struct	xmitwork;	/* per-conn. xmit workqueue */
203 	unsigned long		suspend_tx;	/* suspend Tx */
204 	unsigned long		suspend_rx;	/* suspend Rx */
205 
206 	/* abort */
207 	wait_queue_head_t	ehwait;		/* used in eh_abort() */
208 	struct iscsi_tm		tmhdr;
209 	struct timer_list	tmf_timer;
210 	int			tmf_state;	/* see TMF_INITIAL, etc.*/
211 
212 	/* negotiated params */
213 	unsigned		max_recv_dlength; /* initiator_max_recv_dsl*/
214 	unsigned		max_xmit_dlength; /* target_max_recv_dsl */
215 	int			hdrdgst_en;
216 	int			datadgst_en;
217 	int			ifmarker_en;
218 	int			ofmarker_en;
219 	/* values userspace uses to id a conn */
220 	int			persistent_port;
221 	char			*persistent_address;
222 
223 	unsigned		max_segment_size;
224 	unsigned		tcp_xmit_wsf;
225 	unsigned		tcp_recv_wsf;
226 	uint16_t		keepalive_tmo;
227 	uint16_t		local_port;
228 	uint8_t			tcp_timestamp_stat;
229 	uint8_t			tcp_nagle_disable;
230 	uint8_t			tcp_wsf_disable;
231 	uint8_t			tcp_timer_scale;
232 	uint8_t			tcp_timestamp_en;
233 	uint8_t			fragment_disable;
234 	uint8_t			ipv4_tos;
235 	uint8_t			ipv6_traffic_class;
236 	uint8_t			ipv6_flow_label;
237 	uint8_t			is_fw_assigned_ipv6;
238 	char			*local_ipaddr;
239 
240 	/* MIB-statistics */
241 	uint64_t		txdata_octets;
242 	uint64_t		rxdata_octets;
243 	uint32_t		scsicmd_pdus_cnt;
244 	uint32_t		dataout_pdus_cnt;
245 	uint32_t		scsirsp_pdus_cnt;
246 	uint32_t		datain_pdus_cnt;
247 	uint32_t		r2t_pdus_cnt;
248 	uint32_t		tmfcmd_pdus_cnt;
249 	int32_t			tmfrsp_pdus_cnt;
250 
251 	/* custom statistics */
252 	uint32_t		eh_abort_cnt;
253 	uint32_t		fmr_unalign_cnt;
254 };
255 
256 struct iscsi_pool {
257 	struct kfifo		queue;		/* FIFO Queue */
258 	void			**pool;		/* Pool of elements */
259 	int			max;		/* Max number of elements */
260 };
261 
262 /* Session's states */
263 enum {
264 	ISCSI_STATE_FREE = 1,
265 	ISCSI_STATE_LOGGED_IN,
266 	ISCSI_STATE_FAILED,
267 	ISCSI_STATE_TERMINATE,
268 	ISCSI_STATE_IN_RECOVERY,
269 	ISCSI_STATE_RECOVERY_FAILED,
270 	ISCSI_STATE_LOGGING_OUT,
271 };
272 
273 struct iscsi_session {
274 	struct iscsi_cls_session *cls_session;
275 	/*
276 	 * Syncs up the scsi eh thread with the iscsi eh thread when sending
277 	 * task management functions. This must be taken before the session
278 	 * and recv lock.
279 	 */
280 	struct mutex		eh_mutex;
281 
282 	/* iSCSI session-wide sequencing */
283 	uint32_t		cmdsn;
284 	uint32_t		exp_cmdsn;
285 	uint32_t		max_cmdsn;
286 
287 	/* This tracks the reqs queued into the initiator */
288 	uint32_t		queued_cmdsn;
289 
290 	/* configuration */
291 	int			abort_timeout;
292 	int			lu_reset_timeout;
293 	int			tgt_reset_timeout;
294 	int			initial_r2t_en;
295 	unsigned short		max_r2t;
296 	int			imm_data_en;
297 	unsigned		first_burst;
298 	unsigned		max_burst;
299 	int			time2wait;
300 	int			time2retain;
301 	int			pdu_inorder_en;
302 	int			dataseq_inorder_en;
303 	int			erl;
304 	int			fast_abort;
305 	int			tpgt;
306 	char			*username;
307 	char			*username_in;
308 	char			*password;
309 	char			*password_in;
310 	char			*targetname;
311 	char			*targetalias;
312 	char			*ifacename;
313 	char			*initiatorname;
314 	char			*boot_root;
315 	char			*boot_nic;
316 	char			*boot_target;
317 	char			*portal_type;
318 	char			*discovery_parent_type;
319 	uint16_t		discovery_parent_idx;
320 	uint16_t		def_taskmgmt_tmo;
321 	uint16_t		tsid;
322 	uint8_t			auto_snd_tgt_disable;
323 	uint8_t			discovery_sess;
324 	uint8_t			chap_auth_en;
325 	uint8_t			discovery_logout_en;
326 	uint8_t			bidi_chap_en;
327 	uint8_t			discovery_auth_optional;
328 	uint8_t			isid[ISID_SIZE];
329 
330 	/* control data */
331 	struct iscsi_transport	*tt;
332 	struct Scsi_Host	*host;
333 	struct iscsi_conn	*leadconn;	/* leading connection */
334 	/* Between the forward and the backward locks exists a strict locking
335 	 * hierarchy. The mutual exclusion zone protected by the forward lock
336 	 * can enclose the mutual exclusion zone protected by the backward lock
337 	 * but not vice versa.
338 	 */
339 	spinlock_t		frwd_lock;	/* protects session state, *
340 						 * cmdsn, queued_cmdsn     *
341 						 * session resources:      *
342 						 * - cmdpool kfifo_out ,   *
343 						 * - mgmtpool,		   */
344 	spinlock_t		back_lock;	/* protects cmdsn_exp      *
345 						 * cmdsn_max,              *
346 						 * cmdpool kfifo_in        */
347 	int			state;		/* session state           */
348 	int			age;		/* counts session re-opens */
349 
350 	int			scsi_cmds_max; 	/* max scsi commands */
351 	int			cmds_max;	/* size of cmds array */
352 	struct iscsi_task	**cmds;		/* Original Cmds arr */
353 	struct iscsi_pool	cmdpool;	/* PDU's pool */
354 	void			*dd_data;	/* LLD private data */
355 };
356 
357 enum {
358 	ISCSI_HOST_SETUP,
359 	ISCSI_HOST_REMOVED,
360 };
361 
362 struct iscsi_host {
363 	char			*initiatorname;
364 	/* hw address or netdev iscsi connection is bound to */
365 	char			*hwaddress;
366 	char			*netdev;
367 
368 	wait_queue_head_t	session_removal_wq;
369 	/* protects sessions and state */
370 	spinlock_t		lock;
371 	int			num_sessions;
372 	int			state;
373 
374 	struct workqueue_struct	*workq;
375 	char			workq_name[20];
376 };
377 
378 /*
379  * scsi host template
380  */
381 extern int iscsi_eh_abort(struct scsi_cmnd *sc);
382 extern int iscsi_eh_recover_target(struct scsi_cmnd *sc);
383 extern int iscsi_eh_session_reset(struct scsi_cmnd *sc);
384 extern int iscsi_eh_device_reset(struct scsi_cmnd *sc);
385 extern int iscsi_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *sc);
386 
387 /*
388  * iSCSI host helpers.
389  */
390 #define iscsi_host_priv(_shost) \
391 	(shost_priv(_shost) + sizeof(struct iscsi_host))
392 
393 extern int iscsi_host_set_param(struct Scsi_Host *shost,
394 				enum iscsi_host_param param, char *buf,
395 				int buflen);
396 extern int iscsi_host_get_param(struct Scsi_Host *shost,
397 				enum iscsi_host_param param, char *buf);
398 extern int iscsi_host_add(struct Scsi_Host *shost, struct device *pdev);
399 extern struct Scsi_Host *iscsi_host_alloc(struct scsi_host_template *sht,
400 					  int dd_data_size,
401 					  bool xmit_can_sleep);
402 extern void iscsi_host_remove(struct Scsi_Host *shost);
403 extern void iscsi_host_free(struct Scsi_Host *shost);
404 extern int iscsi_target_alloc(struct scsi_target *starget);
405 
406 /*
407  * session management
408  */
409 extern struct iscsi_cls_session *
410 iscsi_session_setup(struct iscsi_transport *, struct Scsi_Host *shost,
411 		    uint16_t, int, int, uint32_t, unsigned int);
412 extern void iscsi_session_teardown(struct iscsi_cls_session *);
413 extern void iscsi_session_recovery_timedout(struct iscsi_cls_session *);
414 extern int iscsi_set_param(struct iscsi_cls_conn *cls_conn,
415 			   enum iscsi_param param, char *buf, int buflen);
416 extern int iscsi_session_get_param(struct iscsi_cls_session *cls_session,
417 				   enum iscsi_param param, char *buf);
418 
419 #define iscsi_session_printk(prefix, _sess, fmt, a...)	\
420 	iscsi_cls_session_printk(prefix, _sess->cls_session, fmt, ##a)
421 
422 /*
423  * connection management
424  */
425 extern struct iscsi_cls_conn *iscsi_conn_setup(struct iscsi_cls_session *,
426 					       int, uint32_t);
427 extern void iscsi_conn_teardown(struct iscsi_cls_conn *);
428 extern int iscsi_conn_start(struct iscsi_cls_conn *);
429 extern void iscsi_conn_stop(struct iscsi_cls_conn *, int);
430 extern int iscsi_conn_bind(struct iscsi_cls_session *, struct iscsi_cls_conn *,
431 			   int);
432 extern void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err);
433 extern void iscsi_session_failure(struct iscsi_session *session,
434 				  enum iscsi_err err);
435 extern int iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
436 				enum iscsi_param param, char *buf);
437 extern int iscsi_conn_get_addr_param(struct sockaddr_storage *addr,
438 				     enum iscsi_param param, char *buf);
439 extern void iscsi_suspend_tx(struct iscsi_conn *conn);
440 extern void iscsi_suspend_queue(struct iscsi_conn *conn);
441 extern void iscsi_conn_queue_work(struct iscsi_conn *conn);
442 
443 #define iscsi_conn_printk(prefix, _c, fmt, a...) \
444 	iscsi_cls_conn_printk(prefix, ((struct iscsi_conn *)_c)->cls_conn, \
445 			      fmt, ##a)
446 
447 /*
448  * pdu and task processing
449  */
450 extern void iscsi_update_cmdsn(struct iscsi_session *, struct iscsi_nopin *);
451 extern void iscsi_prep_data_out_pdu(struct iscsi_task *task,
452 				    struct iscsi_r2t_info *r2t,
453 				    struct iscsi_data *hdr);
454 extern int iscsi_conn_send_pdu(struct iscsi_cls_conn *, struct iscsi_hdr *,
455 				char *, uint32_t);
456 extern int iscsi_complete_pdu(struct iscsi_conn *, struct iscsi_hdr *,
457 			      char *, int);
458 extern int __iscsi_complete_pdu(struct iscsi_conn *, struct iscsi_hdr *,
459 				char *, int);
460 extern int iscsi_verify_itt(struct iscsi_conn *, itt_t);
461 extern struct iscsi_task *iscsi_itt_to_ctask(struct iscsi_conn *, itt_t);
462 extern struct iscsi_task *iscsi_itt_to_task(struct iscsi_conn *, itt_t);
463 extern void iscsi_requeue_task(struct iscsi_task *task);
464 extern void iscsi_put_task(struct iscsi_task *task);
465 extern void __iscsi_put_task(struct iscsi_task *task);
466 extern void __iscsi_get_task(struct iscsi_task *task);
467 extern void iscsi_complete_scsi_task(struct iscsi_task *task,
468 				     uint32_t exp_cmdsn, uint32_t max_cmdsn);
469 
470 /*
471  * generic helpers
472  */
473 extern void iscsi_pool_free(struct iscsi_pool *);
474 extern int iscsi_pool_init(struct iscsi_pool *, int, void ***, int);
475 extern int iscsi_switch_str_param(char **, char *);
476 
477 /*
478  * inline functions to deal with padding.
479  */
480 static inline unsigned int
481 iscsi_padded(unsigned int len)
482 {
483 	return (len + ISCSI_PAD_LEN - 1) & ~(ISCSI_PAD_LEN - 1);
484 }
485 
486 static inline unsigned int
487 iscsi_padding(unsigned int len)
488 {
489 	len &= (ISCSI_PAD_LEN - 1);
490 	if (len)
491 		len = ISCSI_PAD_LEN - len;
492 	return len;
493 }
494 
495 #endif
496