1/*
2 * iSCSI lib definitions
3 *
4 * Copyright (C) 2006 Red Hat, Inc.  All rights reserved.
5 * Copyright (C) 2004 - 2006 Mike Christie
6 * Copyright (C) 2004 - 2005 Dmitry Yusupov
7 * Copyright (C) 2004 - 2005 Alex Aizman
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or
12 * (at your option) any later version.
13 *
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17 * GNU General Public License for more details.
18 *
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, write to the Free Software
21 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
22 */
23#ifndef LIBISCSI_H
24#define LIBISCSI_H
25
26#include <linux/types.h>
27#include <linux/wait.h>
28#include <linux/mutex.h>
29#include <linux/timer.h>
30#include <linux/workqueue.h>
31#include <linux/kfifo.h>
32#include <scsi/iscsi_proto.h>
33#include <scsi/iscsi_if.h>
34#include <scsi/scsi_transport_iscsi.h>
35
36struct scsi_transport_template;
37struct scsi_host_template;
38struct scsi_device;
39struct Scsi_Host;
40struct scsi_target;
41struct scsi_cmnd;
42struct socket;
43struct iscsi_transport;
44struct iscsi_cls_session;
45struct iscsi_cls_conn;
46struct iscsi_session;
47struct iscsi_nopin;
48struct device;
49
50#define ISCSI_DEF_XMIT_CMDS_MAX	128	/* must be power of 2 */
51#define ISCSI_MGMT_CMDS_MAX	15
52
53#define ISCSI_DEF_CMD_PER_LUN	32
54
55/* Task Mgmt states */
56enum {
57	TMF_INITIAL,
58	TMF_QUEUED,
59	TMF_SUCCESS,
60	TMF_FAILED,
61	TMF_TIMEDOUT,
62	TMF_NOT_FOUND,
63};
64
65#define ISID_SIZE			6
66
67/* Connection suspend "bit" */
68#define ISCSI_SUSPEND_BIT		1
69
70#define ISCSI_ITT_MASK			0x1fff
71#define ISCSI_TOTAL_CMDS_MAX		4096
72/* this must be a power of two greater than ISCSI_MGMT_CMDS_MAX */
73#define ISCSI_TOTAL_CMDS_MIN		16
74#define ISCSI_AGE_SHIFT			28
75#define ISCSI_AGE_MASK			0xf
76
77#define ISCSI_ADDRESS_BUF_LEN		64
78
79enum {
80	/* this is the maximum possible storage for AHSs */
81	ISCSI_MAX_AHS_SIZE = sizeof(struct iscsi_ecdb_ahdr) +
82				sizeof(struct iscsi_rlength_ahdr),
83	ISCSI_DIGEST_SIZE = sizeof(__u32),
84};
85
86
87enum {
88	ISCSI_TASK_FREE,
89	ISCSI_TASK_COMPLETED,
90	ISCSI_TASK_PENDING,
91	ISCSI_TASK_RUNNING,
92	ISCSI_TASK_ABRT_TMF,		/* aborted due to TMF */
93	ISCSI_TASK_ABRT_SESS_RECOV,	/* aborted due to session recovery */
94	ISCSI_TASK_REQUEUE_SCSIQ,	/* qcmd requeueing to scsi-ml */
95};
96
97struct iscsi_r2t_info {
98	__be32			ttt;		/* copied from R2T */
99	__be32			exp_statsn;	/* copied from R2T */
100	uint32_t		data_length;	/* copied from R2T */
101	uint32_t		data_offset;	/* copied from R2T */
102	int			data_count;	/* DATA-Out payload progress */
103	int			datasn;
104	/* LLDs should set/update these values */
105	int			sent;		/* R2T sequence progress */
106};
107
108struct iscsi_task {
109	/*
110	 * Because LLDs allocate their hdr differently, this is a pointer
111	 * and length to that storage. It must be setup at session
112	 * creation time.
113	 */
114	struct iscsi_hdr	*hdr;
115	unsigned short		hdr_max;
116	unsigned short		hdr_len;	/* accumulated size of hdr used */
117	/* copied values in case we need to send tmfs */
118	itt_t			hdr_itt;
119	__be32			cmdsn;
120	struct scsi_lun		lun;
121
122	int			itt;		/* this ITT */
123
124	unsigned		imm_count;	/* imm-data (bytes)   */
125	/* offset in unsolicited stream (bytes); */
126	struct iscsi_r2t_info	unsol_r2t;
127	char			*data;		/* mgmt payload */
128	unsigned		data_count;
129	struct scsi_cmnd	*sc;		/* associated SCSI cmd*/
130	struct iscsi_conn	*conn;		/* used connection    */
131
132	/* data processing tracking */
133	unsigned long		last_xfer;
134	unsigned long		last_timeout;
135	bool			have_checked_conn;
136
137	/* T10 protection information */
138	bool			protected;
139
140	/* state set/tested under session->lock */
141	int			state;
142	atomic_t		refcount;
143	struct list_head	running;	/* running cmd list */
144	void			*dd_data;	/* driver/transport data */
145};
146
147static inline int iscsi_task_has_unsol_data(struct iscsi_task *task)
148{
149	return task->unsol_r2t.data_length > task->unsol_r2t.sent;
150}
151
152static inline void* iscsi_next_hdr(struct iscsi_task *task)
153{
154	return (void*)task->hdr + task->hdr_len;
155}
156
157/* Connection's states */
158enum {
159	ISCSI_CONN_INITIAL_STAGE,
160	ISCSI_CONN_STARTED,
161	ISCSI_CONN_STOPPED,
162	ISCSI_CONN_CLEANUP_WAIT,
163};
164
165struct 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	struct list_head	mgmtqueue;	/* mgmt (control) xmit queue */
200	struct list_head	cmdqueue;	/* data-path cmd queue */
201	struct list_head	requeue;	/* tasks needing another run */
202	struct work_struct	xmitwork;	/* per-conn. xmit workqueue */
203	unsigned long		suspend_tx;	/* suspend Tx */
204	unsigned long		suspend_rx;	/* suspend Rx */
205
206	/* abort */
207	wait_queue_head_t	ehwait;		/* used in eh_abort() */
208	struct iscsi_tm		tmhdr;
209	struct timer_list	tmf_timer;
210	int			tmf_state;	/* see TMF_INITIAL, etc.*/
211
212	/* negotiated params */
213	unsigned		max_recv_dlength; /* initiator_max_recv_dsl*/
214	unsigned		max_xmit_dlength; /* target_max_recv_dsl */
215	int			hdrdgst_en;
216	int			datadgst_en;
217	int			ifmarker_en;
218	int			ofmarker_en;
219	/* values userspace uses to id a conn */
220	int			persistent_port;
221	char			*persistent_address;
222
223	unsigned		max_segment_size;
224	unsigned		tcp_xmit_wsf;
225	unsigned		tcp_recv_wsf;
226	uint16_t		keepalive_tmo;
227	uint16_t		local_port;
228	uint8_t			tcp_timestamp_stat;
229	uint8_t			tcp_nagle_disable;
230	uint8_t			tcp_wsf_disable;
231	uint8_t			tcp_timer_scale;
232	uint8_t			tcp_timestamp_en;
233	uint8_t			fragment_disable;
234	uint8_t			ipv4_tos;
235	uint8_t			ipv6_traffic_class;
236	uint8_t			ipv6_flow_label;
237	uint8_t			is_fw_assigned_ipv6;
238	char			*local_ipaddr;
239
240	/* MIB-statistics */
241	uint64_t		txdata_octets;
242	uint64_t		rxdata_octets;
243	uint32_t		scsicmd_pdus_cnt;
244	uint32_t		dataout_pdus_cnt;
245	uint32_t		scsirsp_pdus_cnt;
246	uint32_t		datain_pdus_cnt;
247	uint32_t		r2t_pdus_cnt;
248	uint32_t		tmfcmd_pdus_cnt;
249	int32_t			tmfrsp_pdus_cnt;
250
251	/* custom statistics */
252	uint32_t		eh_abort_cnt;
253	uint32_t		fmr_unalign_cnt;
254};
255
256struct iscsi_pool {
257	struct kfifo		queue;		/* FIFO Queue */
258	void			**pool;		/* Pool of elements */
259	int			max;		/* Max number of elements */
260};
261
262/* Session's states */
263enum {
264	ISCSI_STATE_FREE = 1,
265	ISCSI_STATE_LOGGED_IN,
266	ISCSI_STATE_FAILED,
267	ISCSI_STATE_TERMINATE,
268	ISCSI_STATE_IN_RECOVERY,
269	ISCSI_STATE_RECOVERY_FAILED,
270	ISCSI_STATE_LOGGING_OUT,
271};
272
273struct iscsi_session {
274	struct iscsi_cls_session *cls_session;
275	/*
276	 * Syncs up the scsi eh thread with the iscsi eh thread when sending
277	 * task management functions. This must be taken before the session
278	 * and recv lock.
279	 */
280	struct mutex		eh_mutex;
281
282	/* iSCSI session-wide sequencing */
283	uint32_t		cmdsn;
284	uint32_t		exp_cmdsn;
285	uint32_t		max_cmdsn;
286
287	/* This tracks the reqs queued into the initiator */
288	uint32_t		queued_cmdsn;
289
290	/* configuration */
291	int			abort_timeout;
292	int			lu_reset_timeout;
293	int			tgt_reset_timeout;
294	int			initial_r2t_en;
295	unsigned short		max_r2t;
296	int			imm_data_en;
297	unsigned		first_burst;
298	unsigned		max_burst;
299	int			time2wait;
300	int			time2retain;
301	int			pdu_inorder_en;
302	int			dataseq_inorder_en;
303	int			erl;
304	int			fast_abort;
305	int			tpgt;
306	char			*username;
307	char			*username_in;
308	char			*password;
309	char			*password_in;
310	char			*targetname;
311	char			*targetalias;
312	char			*ifacename;
313	char			*initiatorname;
314	char			*boot_root;
315	char			*boot_nic;
316	char			*boot_target;
317	char			*portal_type;
318	char			*discovery_parent_type;
319	uint16_t		discovery_parent_idx;
320	uint16_t		def_taskmgmt_tmo;
321	uint16_t		tsid;
322	uint8_t			auto_snd_tgt_disable;
323	uint8_t			discovery_sess;
324	uint8_t			chap_auth_en;
325	uint8_t			discovery_logout_en;
326	uint8_t			bidi_chap_en;
327	uint8_t			discovery_auth_optional;
328	uint8_t			isid[ISID_SIZE];
329
330	/* control data */
331	struct iscsi_transport	*tt;
332	struct Scsi_Host	*host;
333	struct iscsi_conn	*leadconn;	/* leading connection */
334	/* Between the forward and the backward locks exists a strict locking
335	 * hierarchy. The mutual exclusion zone protected by the forward lock
336	 * can enclose the mutual exclusion zone protected by the backward lock
337	 * but not vice versa.
338	 */
339	spinlock_t		frwd_lock;	/* protects session state, *
340						 * cmdsn, queued_cmdsn     *
341						 * session resources:      *
342						 * - cmdpool kfifo_out ,   *
343						 * - mgmtpool,		   */
344	spinlock_t		back_lock;	/* protects cmdsn_exp      *
345						 * cmdsn_max,              *
346						 * cmdpool kfifo_in        */
347	int			state;		/* session state           */
348	int			age;		/* counts session re-opens */
349
350	int			scsi_cmds_max; 	/* max scsi commands */
351	int			cmds_max;	/* size of cmds array */
352	struct iscsi_task	**cmds;		/* Original Cmds arr */
353	struct iscsi_pool	cmdpool;	/* PDU's pool */
354	void			*dd_data;	/* LLD private data */
355};
356
357enum {
358	ISCSI_HOST_SETUP,
359	ISCSI_HOST_REMOVED,
360};
361
362struct iscsi_host {
363	char			*initiatorname;
364	/* hw address or netdev iscsi connection is bound to */
365	char			*hwaddress;
366	char			*netdev;
367
368	wait_queue_head_t	session_removal_wq;
369	/* protects sessions and state */
370	spinlock_t		lock;
371	int			num_sessions;
372	int			state;
373
374	struct workqueue_struct	*workq;
375	char			workq_name[20];
376};
377
378/*
379 * scsi host template
380 */
381extern int iscsi_eh_abort(struct scsi_cmnd *sc);
382extern int iscsi_eh_recover_target(struct scsi_cmnd *sc);
383extern int iscsi_eh_session_reset(struct scsi_cmnd *sc);
384extern int iscsi_eh_device_reset(struct scsi_cmnd *sc);
385extern int iscsi_queuecommand(struct Scsi_Host *host, 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
393extern int iscsi_host_set_param(struct Scsi_Host *shost,
394				enum iscsi_host_param param, char *buf,
395				int buflen);
396extern int iscsi_host_get_param(struct Scsi_Host *shost,
397				enum iscsi_host_param param, char *buf);
398extern int iscsi_host_add(struct Scsi_Host *shost, struct device *pdev);
399extern struct Scsi_Host *iscsi_host_alloc(struct scsi_host_template *sht,
400					  int dd_data_size,
401					  bool xmit_can_sleep);
402extern void iscsi_host_remove(struct Scsi_Host *shost);
403extern void iscsi_host_free(struct Scsi_Host *shost);
404extern int iscsi_target_alloc(struct scsi_target *starget);
405
406/*
407 * session management
408 */
409extern struct iscsi_cls_session *
410iscsi_session_setup(struct iscsi_transport *, struct Scsi_Host *shost,
411		    uint16_t, int, int, uint32_t, unsigned int);
412extern void iscsi_session_teardown(struct iscsi_cls_session *);
413extern void iscsi_session_recovery_timedout(struct iscsi_cls_session *);
414extern int iscsi_set_param(struct iscsi_cls_conn *cls_conn,
415			   enum iscsi_param param, char *buf, int buflen);
416extern int iscsi_session_get_param(struct iscsi_cls_session *cls_session,
417				   enum iscsi_param param, char *buf);
418
419#define iscsi_session_printk(prefix, _sess, fmt, a...)	\
420	iscsi_cls_session_printk(prefix, _sess->cls_session, fmt, ##a)
421
422/*
423 * connection management
424 */
425extern struct iscsi_cls_conn *iscsi_conn_setup(struct iscsi_cls_session *,
426					       int, uint32_t);
427extern void iscsi_conn_teardown(struct iscsi_cls_conn *);
428extern int iscsi_conn_start(struct iscsi_cls_conn *);
429extern void iscsi_conn_stop(struct iscsi_cls_conn *, int);
430extern int iscsi_conn_bind(struct iscsi_cls_session *, struct iscsi_cls_conn *,
431			   int);
432extern void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err);
433extern void iscsi_session_failure(struct iscsi_session *session,
434				  enum iscsi_err err);
435extern int iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
436				enum iscsi_param param, char *buf);
437extern int iscsi_conn_get_addr_param(struct sockaddr_storage *addr,
438				     enum iscsi_param param, char *buf);
439extern void iscsi_suspend_tx(struct iscsi_conn *conn);
440extern void iscsi_suspend_queue(struct iscsi_conn *conn);
441extern void iscsi_conn_queue_work(struct iscsi_conn *conn);
442
443#define iscsi_conn_printk(prefix, _c, fmt, a...) \
444	iscsi_cls_conn_printk(prefix, ((struct iscsi_conn *)_c)->cls_conn, \
445			      fmt, ##a)
446
447/*
448 * pdu and task processing
449 */
450extern void iscsi_update_cmdsn(struct iscsi_session *, struct iscsi_nopin *);
451extern void iscsi_prep_data_out_pdu(struct iscsi_task *task,
452				    struct iscsi_r2t_info *r2t,
453				    struct iscsi_data *hdr);
454extern int iscsi_conn_send_pdu(struct iscsi_cls_conn *, struct iscsi_hdr *,
455				char *, uint32_t);
456extern int iscsi_complete_pdu(struct iscsi_conn *, struct iscsi_hdr *,
457			      char *, int);
458extern int __iscsi_complete_pdu(struct iscsi_conn *, struct iscsi_hdr *,
459				char *, int);
460extern int iscsi_verify_itt(struct iscsi_conn *, itt_t);
461extern struct iscsi_task *iscsi_itt_to_ctask(struct iscsi_conn *, itt_t);
462extern struct iscsi_task *iscsi_itt_to_task(struct iscsi_conn *, itt_t);
463extern void iscsi_requeue_task(struct iscsi_task *task);
464extern void iscsi_put_task(struct iscsi_task *task);
465extern void __iscsi_put_task(struct iscsi_task *task);
466extern void __iscsi_get_task(struct iscsi_task *task);
467extern void iscsi_complete_scsi_task(struct iscsi_task *task,
468				     uint32_t exp_cmdsn, uint32_t max_cmdsn);
469
470/*
471 * generic helpers
472 */
473extern void iscsi_pool_free(struct iscsi_pool *);
474extern int iscsi_pool_init(struct iscsi_pool *, int, void ***, int);
475extern int iscsi_switch_str_param(char **, char *);
476
477/*
478 * inline functions to deal with padding.
479 */
480static inline unsigned int
481iscsi_padded(unsigned int len)
482{
483	return (len + ISCSI_PAD_LEN - 1) & ~(ISCSI_PAD_LEN - 1);
484}
485
486static inline unsigned int
487iscsi_padding(unsigned int len)
488{
489	len &= (ISCSI_PAD_LEN - 1);
490	if (len)
491		len = ISCSI_PAD_LEN - len;
492	return len;
493}
494
495#endif
496