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