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_cmnd.h>
23 #include <scsi/scsi_transport_iscsi.h>
24 
25 struct scsi_transport_template;
26 struct scsi_host_template;
27 struct scsi_device;
28 struct Scsi_Host;
29 struct scsi_target;
30 struct scsi_cmnd;
31 struct socket;
32 struct iscsi_transport;
33 struct iscsi_cls_session;
34 struct iscsi_cls_conn;
35 struct iscsi_session;
36 struct iscsi_nopin;
37 struct device;
38 
39 #define ISCSI_DEF_XMIT_CMDS_MAX	128	/* must be power of 2 */
40 #define ISCSI_MGMT_CMDS_MAX	15
41 
42 #define ISCSI_DEF_CMD_PER_LUN	32
43 
44 /* Task Mgmt states */
45 enum {
46 	TMF_INITIAL,
47 	TMF_QUEUED,
48 	TMF_SUCCESS,
49 	TMF_FAILED,
50 	TMF_TIMEDOUT,
51 	TMF_NOT_FOUND,
52 };
53 
54 #define ISID_SIZE			6
55 
56 /* Connection flags */
57 #define ISCSI_CONN_FLAG_SUSPEND_TX	0
58 #define ISCSI_CONN_FLAG_SUSPEND_RX	1
59 #define ISCSI_CONN_FLAG_BOUND		2
60 
61 #define ISCSI_ITT_MASK			0x1fff
62 #define ISCSI_TOTAL_CMDS_MAX		4096
63 /* this must be a power of two greater than ISCSI_MGMT_CMDS_MAX */
64 #define ISCSI_TOTAL_CMDS_MIN		16
65 #define ISCSI_AGE_SHIFT			28
66 #define ISCSI_AGE_MASK			0xf
67 
68 #define ISCSI_ADDRESS_BUF_LEN		64
69 
70 enum {
71 	/* this is the maximum possible storage for AHSs */
72 	ISCSI_MAX_AHS_SIZE = sizeof(struct iscsi_ecdb_ahdr) +
73 				sizeof(struct iscsi_rlength_ahdr),
74 	ISCSI_DIGEST_SIZE = sizeof(__u32),
75 };
76 
77 
78 enum {
79 	ISCSI_TASK_FREE,
80 	ISCSI_TASK_COMPLETED,
81 	ISCSI_TASK_PENDING,
82 	ISCSI_TASK_RUNNING,
83 	ISCSI_TASK_ABRT_TMF,		/* aborted due to TMF */
84 	ISCSI_TASK_ABRT_SESS_RECOV,	/* aborted due to session recovery */
85 	ISCSI_TASK_REQUEUE_SCSIQ,	/* qcmd requeueing to scsi-ml */
86 };
87 
88 struct iscsi_r2t_info {
89 	__be32			ttt;		/* copied from R2T */
90 	__be32			exp_statsn;	/* copied from R2T */
91 	uint32_t		data_length;	/* copied from R2T */
92 	uint32_t		data_offset;	/* copied from R2T */
93 	int			data_count;	/* DATA-Out payload progress */
94 	int			datasn;
95 	/* LLDs should set/update these values */
96 	int			sent;		/* R2T sequence progress */
97 };
98 
99 struct iscsi_task {
100 	/*
101 	 * Because LLDs allocate their hdr differently, this is a pointer
102 	 * and length to that storage. It must be setup at session
103 	 * creation time.
104 	 */
105 	struct iscsi_hdr	*hdr;
106 	unsigned short		hdr_max;
107 	unsigned short		hdr_len;	/* accumulated size of hdr used */
108 	/* copied values in case we need to send tmfs */
109 	itt_t			hdr_itt;
110 	__be32			cmdsn;
111 	struct scsi_lun		lun;
112 
113 	int			itt;		/* this ITT */
114 
115 	unsigned		imm_count;	/* imm-data (bytes)   */
116 	/* offset in unsolicited stream (bytes); */
117 	struct iscsi_r2t_info	unsol_r2t;
118 	char			*data;		/* mgmt payload */
119 	unsigned		data_count;
120 	struct scsi_cmnd	*sc;		/* associated SCSI cmd*/
121 	struct iscsi_conn	*conn;		/* used connection    */
122 
123 	/* data processing tracking */
124 	unsigned long		last_xfer;
125 	unsigned long		last_timeout;
126 	bool			have_checked_conn;
127 
128 	/* T10 protection information */
129 	bool			protected;
130 
131 	/* state set/tested under session->lock */
132 	int			state;
133 	refcount_t		refcount;
134 	struct list_head	running;	/* running cmd list */
135 	void			*dd_data;	/* driver/transport data */
136 };
137 
138 /* invalid scsi_task pointer */
139 #define	INVALID_SCSI_TASK	(struct iscsi_task *)-1l
140 
iscsi_task_has_unsol_data(struct iscsi_task * task)141 static inline int iscsi_task_has_unsol_data(struct iscsi_task *task)
142 {
143 	return task->unsol_r2t.data_length > task->unsol_r2t.sent;
144 }
145 
iscsi_next_hdr(struct iscsi_task * task)146 static inline void* iscsi_next_hdr(struct iscsi_task *task)
147 {
148 	return (void*)task->hdr + task->hdr_len;
149 }
150 
iscsi_task_is_completed(struct iscsi_task * task)151 static inline bool iscsi_task_is_completed(struct iscsi_task *task)
152 {
153 	return task->state == ISCSI_TASK_COMPLETED ||
154 	       task->state == ISCSI_TASK_ABRT_TMF ||
155 	       task->state == ISCSI_TASK_ABRT_SESS_RECOV;
156 }
157 
158 /* Private data associated with struct scsi_cmnd. */
159 struct iscsi_cmd {
160 	struct iscsi_task	*task;
161 	int			age;
162 };
163 
iscsi_cmd(struct scsi_cmnd * cmd)164 static inline struct iscsi_cmd *iscsi_cmd(struct scsi_cmnd *cmd)
165 {
166 	return scsi_cmd_priv(cmd);
167 }
168 
169 /* Connection's states */
170 enum {
171 	ISCSI_CONN_INITIAL_STAGE,
172 	ISCSI_CONN_STARTED,
173 	ISCSI_CONN_STOPPED,
174 	ISCSI_CONN_CLEANUP_WAIT,
175 };
176 
177 struct iscsi_conn {
178 	struct iscsi_cls_conn	*cls_conn;	/* ptr to class connection */
179 	void			*dd_data;	/* iscsi_transport data */
180 	struct iscsi_session	*session;	/* parent session */
181 	/*
182 	 * conn_stop() flag: stop to recover, stop to terminate
183 	 */
184         int			stop_stage;
185 	struct timer_list	transport_timer;
186 	unsigned long		last_recv;
187 	unsigned long		last_ping;
188 	int			ping_timeout;
189 	int			recv_timeout;
190 	struct iscsi_task 	*ping_task;
191 
192 	/* iSCSI connection-wide sequencing */
193 	uint32_t		exp_statsn;
194 	uint32_t		statsn;
195 
196 	/* control data */
197 	int			id;		/* CID */
198 	int			c_stage;	/* connection state */
199 	/*
200 	 * Preallocated buffer for pdus that have data but do not
201 	 * originate from scsi-ml. We never have two pdus using the
202 	 * buffer at the same time. It is only allocated to
203 	 * the default max recv size because the pdus we support
204 	 * should always fit in this buffer
205 	 */
206 	char			*data;
207 	struct iscsi_task 	*login_task;	/* mtask used for login/text */
208 	struct iscsi_task	*task;		/* xmit task in progress */
209 
210 	/* xmit */
211 	/* items must be added/deleted under frwd lock */
212 	struct list_head	mgmtqueue;	/* mgmt (control) xmit queue */
213 	struct list_head	cmdqueue;	/* data-path cmd queue */
214 	struct list_head	requeue;	/* tasks needing another run */
215 	struct work_struct	xmitwork;	/* per-conn. xmit workqueue */
216 	unsigned long		flags;		/* ISCSI_CONN_FLAGs */
217 
218 	/* negotiated params */
219 	unsigned		max_recv_dlength; /* initiator_max_recv_dsl*/
220 	unsigned		max_xmit_dlength; /* target_max_recv_dsl */
221 	int			hdrdgst_en;
222 	int			datadgst_en;
223 	int			ifmarker_en;
224 	int			ofmarker_en;
225 	/* values userspace uses to id a conn */
226 	int			persistent_port;
227 	char			*persistent_address;
228 
229 	unsigned		max_segment_size;
230 	unsigned		tcp_xmit_wsf;
231 	unsigned		tcp_recv_wsf;
232 	uint16_t		keepalive_tmo;
233 	uint16_t		local_port;
234 	uint8_t			tcp_timestamp_stat;
235 	uint8_t			tcp_nagle_disable;
236 	uint8_t			tcp_wsf_disable;
237 	uint8_t			tcp_timer_scale;
238 	uint8_t			tcp_timestamp_en;
239 	uint8_t			fragment_disable;
240 	uint8_t			ipv4_tos;
241 	uint8_t			ipv6_traffic_class;
242 	uint8_t			ipv6_flow_label;
243 	uint8_t			is_fw_assigned_ipv6;
244 	char			*local_ipaddr;
245 
246 	/* MIB-statistics */
247 	uint64_t		txdata_octets;
248 	uint64_t		rxdata_octets;
249 	uint32_t		scsicmd_pdus_cnt;
250 	uint32_t		dataout_pdus_cnt;
251 	uint32_t		scsirsp_pdus_cnt;
252 	uint32_t		datain_pdus_cnt;
253 	uint32_t		r2t_pdus_cnt;
254 	uint32_t		tmfcmd_pdus_cnt;
255 	int32_t			tmfrsp_pdus_cnt;
256 
257 	/* custom statistics */
258 	uint32_t		eh_abort_cnt;
259 	uint32_t		fmr_unalign_cnt;
260 };
261 
262 struct iscsi_pool {
263 	struct kfifo		queue;		/* FIFO Queue */
264 	void			**pool;		/* Pool of elements */
265 	int			max;		/* Max number of elements */
266 };
267 
268 /* Session's states */
269 enum {
270 	ISCSI_STATE_FREE = 1,
271 	ISCSI_STATE_LOGGED_IN,
272 	ISCSI_STATE_FAILED,
273 	ISCSI_STATE_TERMINATE,
274 	ISCSI_STATE_IN_RECOVERY,
275 	ISCSI_STATE_RECOVERY_FAILED,
276 	ISCSI_STATE_LOGGING_OUT,
277 };
278 
279 struct iscsi_session {
280 	struct iscsi_cls_session *cls_session;
281 	/*
282 	 * Syncs up the scsi eh thread with the iscsi eh thread when sending
283 	 * task management functions. This must be taken before the session
284 	 * and recv lock.
285 	 */
286 	struct mutex		eh_mutex;
287 	/* abort */
288 	wait_queue_head_t	ehwait;		/* used in eh_abort() */
289 	struct iscsi_tm		tmhdr;
290 	struct timer_list	tmf_timer;
291 	int			tmf_state;	/* see TMF_INITIAL, etc.*/
292 	struct iscsi_task	*running_aborted_task;
293 
294 	/* iSCSI session-wide sequencing */
295 	uint32_t		cmdsn;
296 	uint32_t		exp_cmdsn;
297 	uint32_t		max_cmdsn;
298 
299 	/* This tracks the reqs queued into the initiator */
300 	uint32_t		queued_cmdsn;
301 
302 	/* configuration */
303 	int			abort_timeout;
304 	int			lu_reset_timeout;
305 	int			tgt_reset_timeout;
306 	int			initial_r2t_en;
307 	unsigned short		max_r2t;
308 	int			imm_data_en;
309 	unsigned		first_burst;
310 	unsigned		max_burst;
311 	int			time2wait;
312 	int			time2retain;
313 	int			pdu_inorder_en;
314 	int			dataseq_inorder_en;
315 	int			erl;
316 	int			fast_abort;
317 	int			tpgt;
318 	char			*username;
319 	char			*username_in;
320 	char			*password;
321 	char			*password_in;
322 	char			*targetname;
323 	char			*targetalias;
324 	char			*ifacename;
325 	char			*initiatorname;
326 	char			*boot_root;
327 	char			*boot_nic;
328 	char			*boot_target;
329 	char			*portal_type;
330 	char			*discovery_parent_type;
331 	uint16_t		discovery_parent_idx;
332 	uint16_t		def_taskmgmt_tmo;
333 	uint16_t		tsid;
334 	uint8_t			auto_snd_tgt_disable;
335 	uint8_t			discovery_sess;
336 	uint8_t			chap_auth_en;
337 	uint8_t			discovery_logout_en;
338 	uint8_t			bidi_chap_en;
339 	uint8_t			discovery_auth_optional;
340 	uint8_t			isid[ISID_SIZE];
341 
342 	/* control data */
343 	struct iscsi_transport	*tt;
344 	struct Scsi_Host	*host;
345 	struct iscsi_conn	*leadconn;	/* leading connection */
346 	/* Between the forward and the backward locks exists a strict locking
347 	 * hierarchy. The mutual exclusion zone protected by the forward lock
348 	 * can enclose the mutual exclusion zone protected by the backward lock
349 	 * but not vice versa.
350 	 */
351 	spinlock_t		frwd_lock;	/* protects session state, *
352 						 * cmdsn, queued_cmdsn     *
353 						 * session resources:      *
354 						 * - cmdpool kfifo_out ,   *
355 						 * - mgmtpool, queues	   */
356 	spinlock_t		back_lock;	/* protects cmdsn_exp      *
357 						 * cmdsn_max,              *
358 						 * cmdpool kfifo_in        */
359 	int			state;		/* session state           */
360 	int			age;		/* counts session re-opens */
361 
362 	int			scsi_cmds_max; 	/* max scsi commands */
363 	int			cmds_max;	/* size of cmds array */
364 	struct iscsi_task	**cmds;		/* Original Cmds arr */
365 	struct iscsi_pool	cmdpool;	/* PDU's pool */
366 	void			*dd_data;	/* LLD private data */
367 };
368 
369 enum {
370 	ISCSI_HOST_SETUP,
371 	ISCSI_HOST_REMOVED,
372 };
373 
374 struct iscsi_host {
375 	char			*initiatorname;
376 	/* hw address or netdev iscsi connection is bound to */
377 	char			*hwaddress;
378 	char			*netdev;
379 
380 	wait_queue_head_t	session_removal_wq;
381 	/* protects sessions and state */
382 	spinlock_t		lock;
383 	int			num_sessions;
384 	int			state;
385 
386 	struct workqueue_struct	*workq;
387 };
388 
389 /*
390  * scsi host template
391  */
392 extern int iscsi_eh_abort(struct scsi_cmnd *sc);
393 extern int iscsi_eh_recover_target(struct scsi_cmnd *sc);
394 extern int iscsi_eh_session_reset(struct scsi_cmnd *sc);
395 extern int iscsi_eh_device_reset(struct scsi_cmnd *sc);
396 extern int iscsi_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *sc);
397 extern enum blk_eh_timer_return iscsi_eh_cmd_timed_out(struct scsi_cmnd *sc);
398 
399 /*
400  * iSCSI host helpers.
401  */
402 #define iscsi_host_priv(_shost) \
403 	(shost_priv(_shost) + sizeof(struct iscsi_host))
404 
405 extern int iscsi_host_set_param(struct Scsi_Host *shost,
406 				enum iscsi_host_param param, char *buf,
407 				int buflen);
408 extern int iscsi_host_get_param(struct Scsi_Host *shost,
409 				enum iscsi_host_param param, char *buf);
410 extern int iscsi_host_add(struct Scsi_Host *shost, struct device *pdev);
411 extern struct Scsi_Host *iscsi_host_alloc(struct scsi_host_template *sht,
412 					  int dd_data_size,
413 					  bool xmit_can_sleep);
414 extern void iscsi_host_remove(struct Scsi_Host *shost, bool is_shutdown);
415 extern void iscsi_host_free(struct Scsi_Host *shost);
416 extern int iscsi_target_alloc(struct scsi_target *starget);
417 extern int iscsi_host_get_max_scsi_cmds(struct Scsi_Host *shost,
418 					uint16_t requested_cmds_max);
419 
420 /*
421  * session management
422  */
423 extern struct iscsi_cls_session *
424 iscsi_session_setup(struct iscsi_transport *, struct Scsi_Host *shost,
425 		    uint16_t, int, int, uint32_t, unsigned int);
426 extern void iscsi_session_teardown(struct iscsi_cls_session *);
427 extern void iscsi_session_recovery_timedout(struct iscsi_cls_session *);
428 extern int iscsi_set_param(struct iscsi_cls_conn *cls_conn,
429 			   enum iscsi_param param, char *buf, int buflen);
430 extern int iscsi_session_get_param(struct iscsi_cls_session *cls_session,
431 				   enum iscsi_param param, char *buf);
432 
433 #define iscsi_session_printk(prefix, _sess, fmt, a...)	\
434 	iscsi_cls_session_printk(prefix, _sess->cls_session, fmt, ##a)
435 
436 /*
437  * connection management
438  */
439 extern struct iscsi_cls_conn *iscsi_conn_setup(struct iscsi_cls_session *,
440 					       int, uint32_t);
441 extern void iscsi_conn_teardown(struct iscsi_cls_conn *);
442 extern int iscsi_conn_start(struct iscsi_cls_conn *);
443 extern void iscsi_conn_stop(struct iscsi_cls_conn *, int);
444 extern int iscsi_conn_bind(struct iscsi_cls_session *, struct iscsi_cls_conn *,
445 			   int);
446 extern void iscsi_conn_unbind(struct iscsi_cls_conn *cls_conn, bool is_active);
447 extern void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err);
448 extern void iscsi_session_failure(struct iscsi_session *session,
449 				  enum iscsi_err err);
450 extern int iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
451 				enum iscsi_param param, char *buf);
452 extern int iscsi_conn_get_addr_param(struct sockaddr_storage *addr,
453 				     enum iscsi_param param, char *buf);
454 extern void iscsi_suspend_tx(struct iscsi_conn *conn);
455 extern void iscsi_suspend_queue(struct iscsi_conn *conn);
456 extern void iscsi_conn_queue_work(struct iscsi_conn *conn);
457 
458 #define iscsi_conn_printk(prefix, _c, fmt, a...) \
459 	iscsi_cls_conn_printk(prefix, ((struct iscsi_conn *)_c)->cls_conn, \
460 			      fmt, ##a)
461 
462 /*
463  * pdu and task processing
464  */
465 extern void iscsi_update_cmdsn(struct iscsi_session *, struct iscsi_nopin *);
466 extern void iscsi_prep_data_out_pdu(struct iscsi_task *task,
467 				    struct iscsi_r2t_info *r2t,
468 				    struct iscsi_data *hdr);
469 extern int iscsi_conn_send_pdu(struct iscsi_cls_conn *, struct iscsi_hdr *,
470 				char *, uint32_t);
471 extern int iscsi_complete_pdu(struct iscsi_conn *, struct iscsi_hdr *,
472 			      char *, int);
473 extern int __iscsi_complete_pdu(struct iscsi_conn *, struct iscsi_hdr *,
474 				char *, int);
475 extern int iscsi_verify_itt(struct iscsi_conn *, itt_t);
476 extern struct iscsi_task *iscsi_itt_to_ctask(struct iscsi_conn *, itt_t);
477 extern struct iscsi_task *iscsi_itt_to_task(struct iscsi_conn *, itt_t);
478 extern void iscsi_requeue_task(struct iscsi_task *task);
479 extern void iscsi_put_task(struct iscsi_task *task);
480 extern void __iscsi_put_task(struct iscsi_task *task);
481 extern void __iscsi_get_task(struct iscsi_task *task);
482 extern void iscsi_complete_scsi_task(struct iscsi_task *task,
483 				     uint32_t exp_cmdsn, uint32_t max_cmdsn);
484 
485 /*
486  * generic helpers
487  */
488 extern void iscsi_pool_free(struct iscsi_pool *);
489 extern int iscsi_pool_init(struct iscsi_pool *, int, void ***, int);
490 extern int iscsi_switch_str_param(char **, char *);
491 
492 /*
493  * inline functions to deal with padding.
494  */
495 static inline unsigned int
iscsi_padded(unsigned int len)496 iscsi_padded(unsigned int len)
497 {
498 	return (len + ISCSI_PAD_LEN - 1) & ~(ISCSI_PAD_LEN - 1);
499 }
500 
501 static inline unsigned int
iscsi_padding(unsigned int len)502 iscsi_padding(unsigned int len)
503 {
504 	len &= (ISCSI_PAD_LEN - 1);
505 	if (len)
506 		len = ISCSI_PAD_LEN - len;
507 	return len;
508 }
509 
510 #endif
511