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
25struct scsi_transport_template;
26struct scsi_host_template;
27struct scsi_device;
28struct Scsi_Host;
29struct scsi_target;
30struct scsi_cmnd;
31struct socket;
32struct iscsi_transport;
33struct iscsi_cls_session;
34struct iscsi_cls_conn;
35struct iscsi_session;
36struct iscsi_nopin;
37struct 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 */
45enum {
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
70enum {
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
78enum {
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
88struct 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
99struct 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
138static 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
143static inline void* iscsi_next_hdr(struct iscsi_task *task)
144{
145	return (void*)task->hdr + task->hdr_len;
146}
147
148static 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/* Private data associated with struct scsi_cmnd. */
156struct iscsi_cmd {
157	struct iscsi_task	*task;
158	int			age;
159};
160
161static inline struct iscsi_cmd *iscsi_cmd(struct scsi_cmnd *cmd)
162{
163	return scsi_cmd_priv(cmd);
164}
165
166/* Connection's states */
167enum {
168	ISCSI_CONN_INITIAL_STAGE,
169	ISCSI_CONN_STARTED,
170	ISCSI_CONN_STOPPED,
171	ISCSI_CONN_CLEANUP_WAIT,
172};
173
174struct iscsi_conn {
175	struct iscsi_cls_conn	*cls_conn;	/* ptr to class connection */
176	void			*dd_data;	/* iscsi_transport data */
177	struct iscsi_session	*session;	/* parent session */
178	/*
179	 * conn_stop() flag: stop to recover, stop to terminate
180	 */
181        int			stop_stage;
182	struct timer_list	transport_timer;
183	unsigned long		last_recv;
184	unsigned long		last_ping;
185	int			ping_timeout;
186	int			recv_timeout;
187	struct iscsi_task 	*ping_task;
188
189	/* iSCSI connection-wide sequencing */
190	uint32_t		exp_statsn;
191	uint32_t		statsn;
192
193	/* control data */
194	int			id;		/* CID */
195	int			c_stage;	/* connection state */
196	/*
197	 * Preallocated buffer for pdus that have data but do not
198	 * originate from scsi-ml. We never have two pdus using the
199	 * buffer at the same time. It is only allocated to
200	 * the default max recv size because the pdus we support
201	 * should always fit in this buffer
202	 */
203	char			*data;
204	struct iscsi_task 	*login_task;	/* mtask used for login/text */
205	struct iscsi_task	*task;		/* xmit task in progress */
206
207	/* xmit */
208	/* items must be added/deleted under frwd lock */
209	struct list_head	mgmtqueue;	/* mgmt (control) xmit queue */
210	struct list_head	cmdqueue;	/* data-path cmd queue */
211	struct list_head	requeue;	/* tasks needing another run */
212	struct work_struct	xmitwork;	/* per-conn. xmit workqueue */
213	/* recv */
214	struct work_struct	recvwork;
215	unsigned long		flags;		/* ISCSI_CONN_FLAGs */
216
217	/* negotiated params */
218	unsigned		max_recv_dlength; /* initiator_max_recv_dsl*/
219	unsigned		max_xmit_dlength; /* target_max_recv_dsl */
220	int			hdrdgst_en;
221	int			datadgst_en;
222	int			ifmarker_en;
223	int			ofmarker_en;
224	/* values userspace uses to id a conn */
225	int			persistent_port;
226	char			*persistent_address;
227
228	unsigned		max_segment_size;
229	unsigned		tcp_xmit_wsf;
230	unsigned		tcp_recv_wsf;
231	uint16_t		keepalive_tmo;
232	uint16_t		local_port;
233	uint8_t			tcp_timestamp_stat;
234	uint8_t			tcp_nagle_disable;
235	uint8_t			tcp_wsf_disable;
236	uint8_t			tcp_timer_scale;
237	uint8_t			tcp_timestamp_en;
238	uint8_t			fragment_disable;
239	uint8_t			ipv4_tos;
240	uint8_t			ipv6_traffic_class;
241	uint8_t			ipv6_flow_label;
242	uint8_t			is_fw_assigned_ipv6;
243	char			*local_ipaddr;
244
245	/* MIB-statistics */
246	uint64_t		txdata_octets;
247	uint64_t		rxdata_octets;
248	uint32_t		scsicmd_pdus_cnt;
249	uint32_t		dataout_pdus_cnt;
250	uint32_t		scsirsp_pdus_cnt;
251	uint32_t		datain_pdus_cnt;
252	uint32_t		r2t_pdus_cnt;
253	uint32_t		tmfcmd_pdus_cnt;
254	int32_t			tmfrsp_pdus_cnt;
255
256	/* custom statistics */
257	uint32_t		eh_abort_cnt;
258	uint32_t		fmr_unalign_cnt;
259};
260
261struct iscsi_pool {
262	struct kfifo		queue;		/* FIFO Queue */
263	void			**pool;		/* Pool of elements */
264	int			max;		/* Max number of elements */
265};
266
267/* Session's states */
268enum {
269	ISCSI_STATE_FREE = 1,
270	ISCSI_STATE_LOGGED_IN,
271	ISCSI_STATE_FAILED,
272	ISCSI_STATE_TERMINATE,
273	ISCSI_STATE_IN_RECOVERY,
274	ISCSI_STATE_RECOVERY_FAILED,
275	ISCSI_STATE_LOGGING_OUT,
276};
277
278struct iscsi_session {
279	struct iscsi_cls_session *cls_session;
280	/*
281	 * Syncs up the scsi eh thread with the iscsi eh thread when sending
282	 * task management functions. This must be taken before the session
283	 * and recv lock.
284	 */
285	struct mutex		eh_mutex;
286	/* abort */
287	wait_queue_head_t	ehwait;		/* used in eh_abort() */
288	struct iscsi_tm		tmhdr;
289	struct timer_list	tmf_timer;
290	int			tmf_state;	/* see TMF_INITIAL, etc.*/
291	struct iscsi_task	*running_aborted_task;
292
293	/* iSCSI session-wide sequencing */
294	uint32_t		cmdsn;
295	uint32_t		exp_cmdsn;
296	uint32_t		max_cmdsn;
297
298	/* This tracks the reqs queued into the initiator */
299	uint32_t		queued_cmdsn;
300
301	/* configuration */
302	int			abort_timeout;
303	int			lu_reset_timeout;
304	int			tgt_reset_timeout;
305	int			initial_r2t_en;
306	unsigned short		max_r2t;
307	int			imm_data_en;
308	unsigned		first_burst;
309	unsigned		max_burst;
310	int			time2wait;
311	int			time2retain;
312	int			pdu_inorder_en;
313	int			dataseq_inorder_en;
314	int			erl;
315	int			fast_abort;
316	int			tpgt;
317	char			*username;
318	char			*username_in;
319	char			*password;
320	char			*password_in;
321	char			*targetname;
322	char			*targetalias;
323	char			*ifacename;
324	char			*initiatorname;
325	char			*boot_root;
326	char			*boot_nic;
327	char			*boot_target;
328	char			*portal_type;
329	char			*discovery_parent_type;
330	uint16_t		discovery_parent_idx;
331	uint16_t		def_taskmgmt_tmo;
332	uint16_t		tsid;
333	uint8_t			auto_snd_tgt_disable;
334	uint8_t			discovery_sess;
335	uint8_t			chap_auth_en;
336	uint8_t			discovery_logout_en;
337	uint8_t			bidi_chap_en;
338	uint8_t			discovery_auth_optional;
339	uint8_t			isid[ISID_SIZE];
340
341	/* control data */
342	struct iscsi_transport	*tt;
343	struct Scsi_Host	*host;
344	struct iscsi_conn	*leadconn;	/* leading connection */
345	/* Between the forward and the backward locks exists a strict locking
346	 * hierarchy. The mutual exclusion zone protected by the forward lock
347	 * can enclose the mutual exclusion zone protected by the backward lock
348	 * but not vice versa.
349	 */
350	spinlock_t		frwd_lock;	/* protects session state, *
351						 * cmdsn, queued_cmdsn     *
352						 * session resources:      *
353						 * - cmdpool kfifo_out ,   *
354						 * - mgmtpool, queues	   */
355	spinlock_t		back_lock;	/* protects cmdsn_exp      *
356						 * cmdsn_max,              *
357						 * cmdpool kfifo_in        */
358	int			state;		/* session state           */
359	int			age;		/* counts session re-opens */
360
361	int			scsi_cmds_max; 	/* max scsi commands */
362	int			cmds_max;	/* size of cmds array */
363	struct iscsi_task	**cmds;		/* Original Cmds arr */
364	struct iscsi_pool	cmdpool;	/* PDU's pool */
365	void			*dd_data;	/* LLD private data */
366};
367
368enum {
369	ISCSI_HOST_SETUP,
370	ISCSI_HOST_REMOVED,
371};
372
373struct iscsi_host {
374	char			*initiatorname;
375	/* hw address or netdev iscsi connection is bound to */
376	char			*hwaddress;
377	char			*netdev;
378
379	wait_queue_head_t	session_removal_wq;
380	/* protects sessions and state */
381	spinlock_t		lock;
382	int			num_sessions;
383	int			state;
384
385	struct workqueue_struct	*workq;
386};
387
388/*
389 * scsi host template
390 */
391extern int iscsi_eh_abort(struct scsi_cmnd *sc);
392extern int iscsi_eh_recover_target(struct scsi_cmnd *sc);
393extern int iscsi_eh_session_reset(struct scsi_cmnd *sc);
394extern int iscsi_eh_device_reset(struct scsi_cmnd *sc);
395extern int iscsi_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *sc);
396extern enum scsi_timeout_action iscsi_eh_cmd_timed_out(struct scsi_cmnd *sc);
397
398/*
399 * iSCSI host helpers.
400 */
401#define iscsi_host_priv(_shost) \
402	(shost_priv(_shost) + sizeof(struct iscsi_host))
403
404extern int iscsi_host_set_param(struct Scsi_Host *shost,
405				enum iscsi_host_param param, char *buf,
406				int buflen);
407extern int iscsi_host_get_param(struct Scsi_Host *shost,
408				enum iscsi_host_param param, char *buf);
409extern int iscsi_host_add(struct Scsi_Host *shost, struct device *pdev);
410extern struct Scsi_Host *iscsi_host_alloc(const struct scsi_host_template *sht,
411					  int dd_data_size,
412					  bool xmit_can_sleep);
413extern void iscsi_host_remove(struct Scsi_Host *shost, bool is_shutdown);
414extern void iscsi_host_free(struct Scsi_Host *shost);
415extern int iscsi_target_alloc(struct scsi_target *starget);
416extern int iscsi_host_get_max_scsi_cmds(struct Scsi_Host *shost,
417					uint16_t requested_cmds_max);
418
419/*
420 * session management
421 */
422extern struct iscsi_cls_session *
423iscsi_session_setup(struct iscsi_transport *, struct Scsi_Host *shost,
424		    uint16_t, int, int, uint32_t, unsigned int);
425void iscsi_session_remove(struct iscsi_cls_session *cls_session);
426void iscsi_session_free(struct iscsi_cls_session *cls_session);
427extern void iscsi_session_teardown(struct iscsi_cls_session *);
428extern void iscsi_session_recovery_timedout(struct iscsi_cls_session *);
429extern int iscsi_set_param(struct iscsi_cls_conn *cls_conn,
430			   enum iscsi_param param, char *buf, int buflen);
431extern int iscsi_session_get_param(struct iscsi_cls_session *cls_session,
432				   enum iscsi_param param, char *buf);
433
434#define iscsi_session_printk(prefix, _sess, fmt, a...)	\
435	iscsi_cls_session_printk(prefix, _sess->cls_session, fmt, ##a)
436
437/*
438 * connection management
439 */
440extern struct iscsi_cls_conn *iscsi_conn_setup(struct iscsi_cls_session *,
441					       int, uint32_t);
442extern void iscsi_conn_teardown(struct iscsi_cls_conn *);
443extern int iscsi_conn_start(struct iscsi_cls_conn *);
444extern void iscsi_conn_stop(struct iscsi_cls_conn *, int);
445extern int iscsi_conn_bind(struct iscsi_cls_session *, struct iscsi_cls_conn *,
446			   int);
447extern void iscsi_conn_unbind(struct iscsi_cls_conn *cls_conn, bool is_active);
448extern void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err);
449extern void iscsi_session_failure(struct iscsi_session *session,
450				  enum iscsi_err err);
451extern int iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
452				enum iscsi_param param, char *buf);
453extern int iscsi_conn_get_addr_param(struct sockaddr_storage *addr,
454				     enum iscsi_param param, char *buf);
455extern void iscsi_suspend_tx(struct iscsi_conn *conn);
456extern void iscsi_suspend_rx(struct iscsi_conn *conn);
457extern void iscsi_suspend_queue(struct iscsi_conn *conn);
458extern void iscsi_conn_queue_xmit(struct iscsi_conn *conn);
459extern void iscsi_conn_queue_recv(struct iscsi_conn *conn);
460
461#define iscsi_conn_printk(prefix, _c, fmt, a...) \
462	iscsi_cls_conn_printk(prefix, ((struct iscsi_conn *)_c)->cls_conn, \
463			      fmt, ##a)
464
465/*
466 * pdu and task processing
467 */
468extern void iscsi_update_cmdsn(struct iscsi_session *, struct iscsi_nopin *);
469extern void iscsi_prep_data_out_pdu(struct iscsi_task *task,
470				    struct iscsi_r2t_info *r2t,
471				    struct iscsi_data *hdr);
472extern int iscsi_conn_send_pdu(struct iscsi_cls_conn *, struct iscsi_hdr *,
473				char *, uint32_t);
474extern int iscsi_complete_pdu(struct iscsi_conn *, struct iscsi_hdr *,
475			      char *, int);
476extern int __iscsi_complete_pdu(struct iscsi_conn *, struct iscsi_hdr *,
477				char *, int);
478extern int iscsi_verify_itt(struct iscsi_conn *, itt_t);
479extern struct iscsi_task *iscsi_itt_to_ctask(struct iscsi_conn *, itt_t);
480extern struct iscsi_task *iscsi_itt_to_task(struct iscsi_conn *, itt_t);
481extern void iscsi_requeue_task(struct iscsi_task *task);
482extern void iscsi_put_task(struct iscsi_task *task);
483extern void __iscsi_put_task(struct iscsi_task *task);
484extern bool iscsi_get_task(struct iscsi_task *task);
485extern void iscsi_complete_scsi_task(struct iscsi_task *task,
486				     uint32_t exp_cmdsn, uint32_t max_cmdsn);
487
488/*
489 * generic helpers
490 */
491extern void iscsi_pool_free(struct iscsi_pool *);
492extern int iscsi_pool_init(struct iscsi_pool *, int, void ***, int);
493extern int iscsi_switch_str_param(char **, char *);
494
495/*
496 * inline functions to deal with padding.
497 */
498static inline unsigned int
499iscsi_padded(unsigned int len)
500{
501	return (len + ISCSI_PAD_LEN - 1) & ~(ISCSI_PAD_LEN - 1);
502}
503
504static inline unsigned int
505iscsi_padding(unsigned int len)
506{
507	len &= (ISCSI_PAD_LEN - 1);
508	if (len)
509		len = ISCSI_PAD_LEN - len;
510	return len;
511}
512
513#endif
514