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1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /*
3  * iSCSI lib definitions
4  *
5  * Copyright (C) 2006 Red Hat, Inc.  All rights reserved.
6  * Copyright (C) 2004 - 2006 Mike Christie
7  * Copyright (C) 2004 - 2005 Dmitry Yusupov
8  * Copyright (C) 2004 - 2005 Alex Aizman
9  */
10 #ifndef LIBISCSI_H
11 #define LIBISCSI_H
12 
13 #include <linux/types.h>
14 #include <linux/wait.h>
15 #include <linux/mutex.h>
16 #include <linux/timer.h>
17 #include <linux/workqueue.h>
18 #include <linux/kfifo.h>
19 #include <linux/refcount.h>
20 #include <scsi/iscsi_proto.h>
21 #include <scsi/iscsi_if.h>
22 #include <scsi/scsi_transport_iscsi.h>
23 
24 struct scsi_transport_template;
25 struct scsi_host_template;
26 struct scsi_device;
27 struct Scsi_Host;
28 struct scsi_target;
29 struct scsi_cmnd;
30 struct socket;
31 struct iscsi_transport;
32 struct iscsi_cls_session;
33 struct iscsi_cls_conn;
34 struct iscsi_session;
35 struct iscsi_nopin;
36 struct device;
37 
38 #define ISCSI_DEF_XMIT_CMDS_MAX	128	/* must be power of 2 */
39 #define ISCSI_MGMT_CMDS_MAX	15
40 
41 #define ISCSI_DEF_CMD_PER_LUN	32
42 
43 /* Task Mgmt states */
44 enum {
45 	TMF_INITIAL,
46 	TMF_QUEUED,
47 	TMF_SUCCESS,
48 	TMF_FAILED,
49 	TMF_TIMEDOUT,
50 	TMF_NOT_FOUND,
51 };
52 
53 #define ISID_SIZE			6
54 
55 /* Connection flags */
56 #define ISCSI_CONN_FLAG_SUSPEND_TX	0
57 #define ISCSI_CONN_FLAG_SUSPEND_RX	1
58 #define ISCSI_CONN_FLAG_BOUND		2
59 
60 #define ISCSI_ITT_MASK			0x1fff
61 #define ISCSI_TOTAL_CMDS_MAX		4096
62 /* this must be a power of two greater than ISCSI_MGMT_CMDS_MAX */
63 #define ISCSI_TOTAL_CMDS_MIN		16
64 #define ISCSI_AGE_SHIFT			28
65 #define ISCSI_AGE_MASK			0xf
66 
67 #define ISCSI_ADDRESS_BUF_LEN		64
68 
69 enum {
70 	/* this is the maximum possible storage for AHSs */
71 	ISCSI_MAX_AHS_SIZE = sizeof(struct iscsi_ecdb_ahdr) +
72 				sizeof(struct iscsi_rlength_ahdr),
73 	ISCSI_DIGEST_SIZE = sizeof(__u32),
74 };
75 
76 
77 enum {
78 	ISCSI_TASK_FREE,
79 	ISCSI_TASK_COMPLETED,
80 	ISCSI_TASK_PENDING,
81 	ISCSI_TASK_RUNNING,
82 	ISCSI_TASK_ABRT_TMF,		/* aborted due to TMF */
83 	ISCSI_TASK_ABRT_SESS_RECOV,	/* aborted due to session recovery */
84 	ISCSI_TASK_REQUEUE_SCSIQ,	/* qcmd requeueing to scsi-ml */
85 };
86 
87 struct iscsi_r2t_info {
88 	__be32			ttt;		/* copied from R2T */
89 	__be32			exp_statsn;	/* copied from R2T */
90 	uint32_t		data_length;	/* copied from R2T */
91 	uint32_t		data_offset;	/* copied from R2T */
92 	int			data_count;	/* DATA-Out payload progress */
93 	int			datasn;
94 	/* LLDs should set/update these values */
95 	int			sent;		/* R2T sequence progress */
96 };
97 
98 struct iscsi_task {
99 	/*
100 	 * Because LLDs allocate their hdr differently, this is a pointer
101 	 * and length to that storage. It must be setup at session
102 	 * creation time.
103 	 */
104 	struct iscsi_hdr	*hdr;
105 	unsigned short		hdr_max;
106 	unsigned short		hdr_len;	/* accumulated size of hdr used */
107 	/* copied values in case we need to send tmfs */
108 	itt_t			hdr_itt;
109 	__be32			cmdsn;
110 	struct scsi_lun		lun;
111 
112 	int			itt;		/* this ITT */
113 
114 	unsigned		imm_count;	/* imm-data (bytes)   */
115 	/* offset in unsolicited stream (bytes); */
116 	struct iscsi_r2t_info	unsol_r2t;
117 	char			*data;		/* mgmt payload */
118 	unsigned		data_count;
119 	struct scsi_cmnd	*sc;		/* associated SCSI cmd*/
120 	struct iscsi_conn	*conn;		/* used connection    */
121 
122 	/* data processing tracking */
123 	unsigned long		last_xfer;
124 	unsigned long		last_timeout;
125 	bool			have_checked_conn;
126 
127 	/* T10 protection information */
128 	bool			protected;
129 
130 	/* state set/tested under session->lock */
131 	int			state;
132 	refcount_t		refcount;
133 	struct list_head	running;	/* running cmd list */
134 	void			*dd_data;	/* driver/transport data */
135 };
136 
137 /* invalid scsi_task pointer */
138 #define	INVALID_SCSI_TASK	(struct iscsi_task *)-1l
139 
iscsi_task_has_unsol_data(struct iscsi_task * task)140 static inline int iscsi_task_has_unsol_data(struct iscsi_task *task)
141 {
142 	return task->unsol_r2t.data_length > task->unsol_r2t.sent;
143 }
144 
iscsi_next_hdr(struct iscsi_task * task)145 static inline void* iscsi_next_hdr(struct iscsi_task *task)
146 {
147 	return (void*)task->hdr + task->hdr_len;
148 }
149 
iscsi_task_is_completed(struct iscsi_task * task)150 static inline bool iscsi_task_is_completed(struct iscsi_task *task)
151 {
152 	return task->state == ISCSI_TASK_COMPLETED ||
153 	       task->state == ISCSI_TASK_ABRT_TMF ||
154 	       task->state == ISCSI_TASK_ABRT_SESS_RECOV;
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 	/* items must be added/deleted under frwd lock */
200 	struct list_head	mgmtqueue;	/* mgmt (control) xmit queue */
201 	struct list_head	cmdqueue;	/* data-path cmd queue */
202 	struct list_head	requeue;	/* tasks needing another run */
203 	struct work_struct	xmitwork;	/* per-conn. xmit workqueue */
204 	/* recv */
205 	struct work_struct	recvwork;
206 	unsigned long		flags;		/* ISCSI_CONN_FLAGs */
207 
208 	/* negotiated params */
209 	unsigned		max_recv_dlength; /* initiator_max_recv_dsl*/
210 	unsigned		max_xmit_dlength; /* target_max_recv_dsl */
211 	int			hdrdgst_en;
212 	int			datadgst_en;
213 	int			ifmarker_en;
214 	int			ofmarker_en;
215 	/* values userspace uses to id a conn */
216 	int			persistent_port;
217 	char			*persistent_address;
218 
219 	unsigned		max_segment_size;
220 	unsigned		tcp_xmit_wsf;
221 	unsigned		tcp_recv_wsf;
222 	uint16_t		keepalive_tmo;
223 	uint16_t		local_port;
224 	uint8_t			tcp_timestamp_stat;
225 	uint8_t			tcp_nagle_disable;
226 	uint8_t			tcp_wsf_disable;
227 	uint8_t			tcp_timer_scale;
228 	uint8_t			tcp_timestamp_en;
229 	uint8_t			fragment_disable;
230 	uint8_t			ipv4_tos;
231 	uint8_t			ipv6_traffic_class;
232 	uint8_t			ipv6_flow_label;
233 	uint8_t			is_fw_assigned_ipv6;
234 	char			*local_ipaddr;
235 
236 	/* MIB-statistics */
237 	uint64_t		txdata_octets;
238 	uint64_t		rxdata_octets;
239 	uint32_t		scsicmd_pdus_cnt;
240 	uint32_t		dataout_pdus_cnt;
241 	uint32_t		scsirsp_pdus_cnt;
242 	uint32_t		datain_pdus_cnt;
243 	uint32_t		r2t_pdus_cnt;
244 	uint32_t		tmfcmd_pdus_cnt;
245 	int32_t			tmfrsp_pdus_cnt;
246 
247 	/* custom statistics */
248 	uint32_t		eh_abort_cnt;
249 	uint32_t		fmr_unalign_cnt;
250 };
251 
252 struct iscsi_pool {
253 	struct kfifo		queue;		/* FIFO Queue */
254 	void			**pool;		/* Pool of elements */
255 	int			max;		/* Max number of elements */
256 };
257 
258 /* Session's states */
259 enum {
260 	ISCSI_STATE_FREE = 1,
261 	ISCSI_STATE_LOGGED_IN,
262 	ISCSI_STATE_FAILED,
263 	ISCSI_STATE_TERMINATE,
264 	ISCSI_STATE_IN_RECOVERY,
265 	ISCSI_STATE_RECOVERY_FAILED,
266 	ISCSI_STATE_LOGGING_OUT,
267 };
268 
269 struct iscsi_session {
270 	struct iscsi_cls_session *cls_session;
271 	/*
272 	 * Syncs up the scsi eh thread with the iscsi eh thread when sending
273 	 * task management functions. This must be taken before the session
274 	 * and recv lock.
275 	 */
276 	struct mutex		eh_mutex;
277 	/* abort */
278 	wait_queue_head_t	ehwait;		/* used in eh_abort() */
279 	struct iscsi_tm		tmhdr;
280 	struct timer_list	tmf_timer;
281 	int			tmf_state;	/* see TMF_INITIAL, etc.*/
282 	struct iscsi_task	*running_aborted_task;
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, queues	   */
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, bool is_shutdown);
406 extern void iscsi_host_free(struct Scsi_Host *shost);
407 extern int iscsi_target_alloc(struct scsi_target *starget);
408 extern int iscsi_host_get_max_scsi_cmds(struct Scsi_Host *shost,
409 					uint16_t requested_cmds_max);
410 
411 /*
412  * session management
413  */
414 extern struct iscsi_cls_session *
415 iscsi_session_setup(struct iscsi_transport *, struct Scsi_Host *shost,
416 		    uint16_t, int, int, uint32_t, unsigned int);
417 void iscsi_session_remove(struct iscsi_cls_session *cls_session);
418 void iscsi_session_free(struct iscsi_cls_session *cls_session);
419 extern void iscsi_session_teardown(struct iscsi_cls_session *);
420 extern void iscsi_session_recovery_timedout(struct iscsi_cls_session *);
421 extern int iscsi_set_param(struct iscsi_cls_conn *cls_conn,
422 			   enum iscsi_param param, char *buf, int buflen);
423 extern int iscsi_session_get_param(struct iscsi_cls_session *cls_session,
424 				   enum iscsi_param param, char *buf);
425 
426 #define iscsi_session_printk(prefix, _sess, fmt, a...)	\
427 	iscsi_cls_session_printk(prefix, _sess->cls_session, fmt, ##a)
428 
429 /*
430  * connection management
431  */
432 extern struct iscsi_cls_conn *iscsi_conn_setup(struct iscsi_cls_session *,
433 					       int, uint32_t);
434 extern void iscsi_conn_teardown(struct iscsi_cls_conn *);
435 extern int iscsi_conn_start(struct iscsi_cls_conn *);
436 extern void iscsi_conn_stop(struct iscsi_cls_conn *, int);
437 extern int iscsi_conn_bind(struct iscsi_cls_session *, struct iscsi_cls_conn *,
438 			   int);
439 extern void iscsi_conn_unbind(struct iscsi_cls_conn *cls_conn, bool is_active);
440 extern void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err);
441 extern void iscsi_session_failure(struct iscsi_session *session,
442 				  enum iscsi_err err);
443 extern int iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
444 				enum iscsi_param param, char *buf);
445 extern int iscsi_conn_get_addr_param(struct sockaddr_storage *addr,
446 				     enum iscsi_param param, char *buf);
447 extern void iscsi_suspend_tx(struct iscsi_conn *conn);
448 extern void iscsi_suspend_rx(struct iscsi_conn *conn);
449 extern void iscsi_suspend_queue(struct iscsi_conn *conn);
450 extern void iscsi_conn_queue_xmit(struct iscsi_conn *conn);
451 extern void iscsi_conn_queue_recv(struct iscsi_conn *conn);
452 
453 #define iscsi_conn_printk(prefix, _c, fmt, a...) \
454 	iscsi_cls_conn_printk(prefix, ((struct iscsi_conn *)_c)->cls_conn, \
455 			      fmt, ##a)
456 
457 /*
458  * pdu and task processing
459  */
460 extern void iscsi_update_cmdsn(struct iscsi_session *, struct iscsi_nopin *);
461 extern void iscsi_prep_data_out_pdu(struct iscsi_task *task,
462 				    struct iscsi_r2t_info *r2t,
463 				    struct iscsi_data *hdr);
464 extern int iscsi_conn_send_pdu(struct iscsi_cls_conn *, struct iscsi_hdr *,
465 				char *, uint32_t);
466 extern int iscsi_complete_pdu(struct iscsi_conn *, struct iscsi_hdr *,
467 			      char *, int);
468 extern int __iscsi_complete_pdu(struct iscsi_conn *, struct iscsi_hdr *,
469 				char *, int);
470 extern int iscsi_verify_itt(struct iscsi_conn *, itt_t);
471 extern struct iscsi_task *iscsi_itt_to_ctask(struct iscsi_conn *, itt_t);
472 extern struct iscsi_task *iscsi_itt_to_task(struct iscsi_conn *, itt_t);
473 extern void iscsi_requeue_task(struct iscsi_task *task);
474 extern void iscsi_put_task(struct iscsi_task *task);
475 extern void __iscsi_put_task(struct iscsi_task *task);
476 extern void __iscsi_get_task(struct iscsi_task *task);
477 extern void iscsi_complete_scsi_task(struct iscsi_task *task,
478 				     uint32_t exp_cmdsn, uint32_t max_cmdsn);
479 
480 /*
481  * generic helpers
482  */
483 extern void iscsi_pool_free(struct iscsi_pool *);
484 extern int iscsi_pool_init(struct iscsi_pool *, int, void ***, int);
485 extern int iscsi_switch_str_param(char **, char *);
486 
487 /*
488  * inline functions to deal with padding.
489  */
490 static inline unsigned int
iscsi_padded(unsigned int len)491 iscsi_padded(unsigned int len)
492 {
493 	return (len + ISCSI_PAD_LEN - 1) & ~(ISCSI_PAD_LEN - 1);
494 }
495 
496 static inline unsigned int
iscsi_padding(unsigned int len)497 iscsi_padding(unsigned int len)
498 {
499 	len &= (ISCSI_PAD_LEN - 1);
500 	if (len)
501 		len = ISCSI_PAD_LEN - len;
502 	return len;
503 }
504 
505 #endif
506