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
24struct scsi_transport_template;
25struct scsi_host_template;
26struct scsi_device;
27struct Scsi_Host;
28struct scsi_target;
29struct scsi_cmnd;
30struct socket;
31struct iscsi_transport;
32struct iscsi_cls_session;
33struct iscsi_cls_conn;
34struct iscsi_session;
35struct iscsi_nopin;
36struct 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 */
44enum {
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
67enum {
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
75enum {
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
85struct 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
96struct 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
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
148/* Connection's states */
149enum {
150	ISCSI_CONN_INITIAL_STAGE,
151	ISCSI_CONN_STARTED,
152	ISCSI_CONN_STOPPED,
153	ISCSI_CONN_CLEANUP_WAIT,
154};
155
156struct iscsi_conn {
157	struct iscsi_cls_conn	*cls_conn;	/* ptr to class connection */
158	void			*dd_data;	/* iscsi_transport data */
159	struct iscsi_session	*session;	/* parent session */
160	/*
161	 * conn_stop() flag: stop to recover, stop to terminate
162	 */
163        int			stop_stage;
164	struct timer_list	transport_timer;
165	unsigned long		last_recv;
166	unsigned long		last_ping;
167	int			ping_timeout;
168	int			recv_timeout;
169	struct iscsi_task 	*ping_task;
170
171	/* iSCSI connection-wide sequencing */
172	uint32_t		exp_statsn;
173	uint32_t		statsn;
174
175	/* control data */
176	int			id;		/* CID */
177	int			c_stage;	/* connection state */
178	/*
179	 * Preallocated buffer for pdus that have data but do not
180	 * originate from scsi-ml. We never have two pdus using the
181	 * buffer at the same time. It is only allocated to
182	 * the default max recv size because the pdus we support
183	 * should always fit in this buffer
184	 */
185	char			*data;
186	struct iscsi_task 	*login_task;	/* mtask used for login/text */
187	struct iscsi_task	*task;		/* xmit task in progress */
188
189	/* xmit */
190	/* items must be added/deleted under frwd lock */
191	struct list_head	mgmtqueue;	/* mgmt (control) xmit queue */
192	struct list_head	cmdqueue;	/* data-path cmd queue */
193	struct list_head	requeue;	/* tasks needing another run */
194	struct work_struct	xmitwork;	/* per-conn. xmit workqueue */
195	unsigned long		suspend_tx;	/* suspend Tx */
196	unsigned long		suspend_rx;	/* suspend Rx */
197
198	/* negotiated params */
199	unsigned		max_recv_dlength; /* initiator_max_recv_dsl*/
200	unsigned		max_xmit_dlength; /* target_max_recv_dsl */
201	int			hdrdgst_en;
202	int			datadgst_en;
203	int			ifmarker_en;
204	int			ofmarker_en;
205	/* values userspace uses to id a conn */
206	int			persistent_port;
207	char			*persistent_address;
208
209	unsigned		max_segment_size;
210	unsigned		tcp_xmit_wsf;
211	unsigned		tcp_recv_wsf;
212	uint16_t		keepalive_tmo;
213	uint16_t		local_port;
214	uint8_t			tcp_timestamp_stat;
215	uint8_t			tcp_nagle_disable;
216	uint8_t			tcp_wsf_disable;
217	uint8_t			tcp_timer_scale;
218	uint8_t			tcp_timestamp_en;
219	uint8_t			fragment_disable;
220	uint8_t			ipv4_tos;
221	uint8_t			ipv6_traffic_class;
222	uint8_t			ipv6_flow_label;
223	uint8_t			is_fw_assigned_ipv6;
224	char			*local_ipaddr;
225
226	/* MIB-statistics */
227	uint64_t		txdata_octets;
228	uint64_t		rxdata_octets;
229	uint32_t		scsicmd_pdus_cnt;
230	uint32_t		dataout_pdus_cnt;
231	uint32_t		scsirsp_pdus_cnt;
232	uint32_t		datain_pdus_cnt;
233	uint32_t		r2t_pdus_cnt;
234	uint32_t		tmfcmd_pdus_cnt;
235	int32_t			tmfrsp_pdus_cnt;
236
237	/* custom statistics */
238	uint32_t		eh_abort_cnt;
239	uint32_t		fmr_unalign_cnt;
240};
241
242struct iscsi_pool {
243	struct kfifo		queue;		/* FIFO Queue */
244	void			**pool;		/* Pool of elements */
245	int			max;		/* Max number of elements */
246};
247
248/* Session's states */
249enum {
250	ISCSI_STATE_FREE = 1,
251	ISCSI_STATE_LOGGED_IN,
252	ISCSI_STATE_FAILED,
253	ISCSI_STATE_TERMINATE,
254	ISCSI_STATE_IN_RECOVERY,
255	ISCSI_STATE_RECOVERY_FAILED,
256	ISCSI_STATE_LOGGING_OUT,
257};
258
259struct iscsi_session {
260	struct iscsi_cls_session *cls_session;
261	/*
262	 * Syncs up the scsi eh thread with the iscsi eh thread when sending
263	 * task management functions. This must be taken before the session
264	 * and recv lock.
265	 */
266	struct mutex		eh_mutex;
267	/* abort */
268	wait_queue_head_t	ehwait;		/* used in eh_abort() */
269	struct iscsi_tm		tmhdr;
270	struct timer_list	tmf_timer;
271	int			tmf_state;	/* see TMF_INITIAL, etc.*/
272
273	/* iSCSI session-wide sequencing */
274	uint32_t		cmdsn;
275	uint32_t		exp_cmdsn;
276	uint32_t		max_cmdsn;
277
278	/* This tracks the reqs queued into the initiator */
279	uint32_t		queued_cmdsn;
280
281	/* configuration */
282	int			abort_timeout;
283	int			lu_reset_timeout;
284	int			tgt_reset_timeout;
285	int			initial_r2t_en;
286	unsigned short		max_r2t;
287	int			imm_data_en;
288	unsigned		first_burst;
289	unsigned		max_burst;
290	int			time2wait;
291	int			time2retain;
292	int			pdu_inorder_en;
293	int			dataseq_inorder_en;
294	int			erl;
295	int			fast_abort;
296	int			tpgt;
297	char			*username;
298	char			*username_in;
299	char			*password;
300	char			*password_in;
301	char			*targetname;
302	char			*targetalias;
303	char			*ifacename;
304	char			*initiatorname;
305	char			*boot_root;
306	char			*boot_nic;
307	char			*boot_target;
308	char			*portal_type;
309	char			*discovery_parent_type;
310	uint16_t		discovery_parent_idx;
311	uint16_t		def_taskmgmt_tmo;
312	uint16_t		tsid;
313	uint8_t			auto_snd_tgt_disable;
314	uint8_t			discovery_sess;
315	uint8_t			chap_auth_en;
316	uint8_t			discovery_logout_en;
317	uint8_t			bidi_chap_en;
318	uint8_t			discovery_auth_optional;
319	uint8_t			isid[ISID_SIZE];
320
321	/* control data */
322	struct iscsi_transport	*tt;
323	struct Scsi_Host	*host;
324	struct iscsi_conn	*leadconn;	/* leading connection */
325	/* Between the forward and the backward locks exists a strict locking
326	 * hierarchy. The mutual exclusion zone protected by the forward lock
327	 * can enclose the mutual exclusion zone protected by the backward lock
328	 * but not vice versa.
329	 */
330	spinlock_t		frwd_lock;	/* protects session state, *
331						 * cmdsn, queued_cmdsn     *
332						 * session resources:      *
333						 * - cmdpool kfifo_out ,   *
334						 * - mgmtpool, queues	   */
335	spinlock_t		back_lock;	/* protects cmdsn_exp      *
336						 * cmdsn_max,              *
337						 * cmdpool kfifo_in        */
338	int			state;		/* session state           */
339	int			age;		/* counts session re-opens */
340
341	int			scsi_cmds_max; 	/* max scsi commands */
342	int			cmds_max;	/* size of cmds array */
343	struct iscsi_task	**cmds;		/* Original Cmds arr */
344	struct iscsi_pool	cmdpool;	/* PDU's pool */
345	void			*dd_data;	/* LLD private data */
346};
347
348enum {
349	ISCSI_HOST_SETUP,
350	ISCSI_HOST_REMOVED,
351};
352
353struct iscsi_host {
354	char			*initiatorname;
355	/* hw address or netdev iscsi connection is bound to */
356	char			*hwaddress;
357	char			*netdev;
358
359	wait_queue_head_t	session_removal_wq;
360	/* protects sessions and state */
361	spinlock_t		lock;
362	int			num_sessions;
363	int			state;
364
365	struct workqueue_struct	*workq;
366	char			workq_name[20];
367};
368
369/*
370 * scsi host template
371 */
372extern int iscsi_eh_abort(struct scsi_cmnd *sc);
373extern int iscsi_eh_recover_target(struct scsi_cmnd *sc);
374extern int iscsi_eh_session_reset(struct scsi_cmnd *sc);
375extern int iscsi_eh_device_reset(struct scsi_cmnd *sc);
376extern int iscsi_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *sc);
377extern enum blk_eh_timer_return iscsi_eh_cmd_timed_out(struct scsi_cmnd *sc);
378
379/*
380 * iSCSI host helpers.
381 */
382#define iscsi_host_priv(_shost) \
383	(shost_priv(_shost) + sizeof(struct iscsi_host))
384
385extern int iscsi_host_set_param(struct Scsi_Host *shost,
386				enum iscsi_host_param param, char *buf,
387				int buflen);
388extern int iscsi_host_get_param(struct Scsi_Host *shost,
389				enum iscsi_host_param param, char *buf);
390extern int iscsi_host_add(struct Scsi_Host *shost, struct device *pdev);
391extern struct Scsi_Host *iscsi_host_alloc(struct scsi_host_template *sht,
392					  int dd_data_size,
393					  bool xmit_can_sleep);
394extern void iscsi_host_remove(struct Scsi_Host *shost);
395extern void iscsi_host_free(struct Scsi_Host *shost);
396extern int iscsi_target_alloc(struct scsi_target *starget);
397extern int iscsi_host_get_max_scsi_cmds(struct Scsi_Host *shost,
398					uint16_t requested_cmds_max);
399
400/*
401 * session management
402 */
403extern struct iscsi_cls_session *
404iscsi_session_setup(struct iscsi_transport *, struct Scsi_Host *shost,
405		    uint16_t, int, int, uint32_t, unsigned int);
406extern void iscsi_session_teardown(struct iscsi_cls_session *);
407extern void iscsi_session_recovery_timedout(struct iscsi_cls_session *);
408extern int iscsi_set_param(struct iscsi_cls_conn *cls_conn,
409			   enum iscsi_param param, char *buf, int buflen);
410extern int iscsi_session_get_param(struct iscsi_cls_session *cls_session,
411				   enum iscsi_param param, char *buf);
412
413#define iscsi_session_printk(prefix, _sess, fmt, a...)	\
414	iscsi_cls_session_printk(prefix, _sess->cls_session, fmt, ##a)
415
416/*
417 * connection management
418 */
419extern struct iscsi_cls_conn *iscsi_conn_setup(struct iscsi_cls_session *,
420					       int, uint32_t);
421extern void iscsi_conn_teardown(struct iscsi_cls_conn *);
422extern int iscsi_conn_start(struct iscsi_cls_conn *);
423extern void iscsi_conn_stop(struct iscsi_cls_conn *, int);
424extern int iscsi_conn_bind(struct iscsi_cls_session *, struct iscsi_cls_conn *,
425			   int);
426extern void iscsi_conn_unbind(struct iscsi_cls_conn *cls_conn, bool is_active);
427extern void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err);
428extern void iscsi_session_failure(struct iscsi_session *session,
429				  enum iscsi_err err);
430extern int iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
431				enum iscsi_param param, char *buf);
432extern int iscsi_conn_get_addr_param(struct sockaddr_storage *addr,
433				     enum iscsi_param param, char *buf);
434extern void iscsi_suspend_tx(struct iscsi_conn *conn);
435extern void iscsi_suspend_queue(struct iscsi_conn *conn);
436extern void iscsi_conn_queue_work(struct iscsi_conn *conn);
437
438#define iscsi_conn_printk(prefix, _c, fmt, a...) \
439	iscsi_cls_conn_printk(prefix, ((struct iscsi_conn *)_c)->cls_conn, \
440			      fmt, ##a)
441
442/*
443 * pdu and task processing
444 */
445extern void iscsi_update_cmdsn(struct iscsi_session *, struct iscsi_nopin *);
446extern void iscsi_prep_data_out_pdu(struct iscsi_task *task,
447				    struct iscsi_r2t_info *r2t,
448				    struct iscsi_data *hdr);
449extern int iscsi_conn_send_pdu(struct iscsi_cls_conn *, struct iscsi_hdr *,
450				char *, uint32_t);
451extern int iscsi_complete_pdu(struct iscsi_conn *, struct iscsi_hdr *,
452			      char *, int);
453extern int __iscsi_complete_pdu(struct iscsi_conn *, struct iscsi_hdr *,
454				char *, int);
455extern int iscsi_verify_itt(struct iscsi_conn *, itt_t);
456extern struct iscsi_task *iscsi_itt_to_ctask(struct iscsi_conn *, itt_t);
457extern struct iscsi_task *iscsi_itt_to_task(struct iscsi_conn *, itt_t);
458extern void iscsi_requeue_task(struct iscsi_task *task);
459extern void iscsi_put_task(struct iscsi_task *task);
460extern void __iscsi_put_task(struct iscsi_task *task);
461extern void __iscsi_get_task(struct iscsi_task *task);
462extern void iscsi_complete_scsi_task(struct iscsi_task *task,
463				     uint32_t exp_cmdsn, uint32_t max_cmdsn);
464
465/*
466 * generic helpers
467 */
468extern void iscsi_pool_free(struct iscsi_pool *);
469extern int iscsi_pool_init(struct iscsi_pool *, int, void ***, int);
470extern int iscsi_switch_str_param(char **, char *);
471
472/*
473 * inline functions to deal with padding.
474 */
475static inline unsigned int
476iscsi_padded(unsigned int len)
477{
478	return (len + ISCSI_PAD_LEN - 1) & ~(ISCSI_PAD_LEN - 1);
479}
480
481static inline unsigned int
482iscsi_padding(unsigned int len)
483{
484	len &= (ISCSI_PAD_LEN - 1);
485	if (len)
486		len = ISCSI_PAD_LEN - len;
487	return len;
488}
489
490#endif
491