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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 
36 struct scsi_transport_template;
37 struct scsi_host_template;
38 struct scsi_device;
39 struct Scsi_Host;
40 struct scsi_target;
41 struct scsi_cmnd;
42 struct socket;
43 struct iscsi_transport;
44 struct iscsi_cls_session;
45 struct iscsi_cls_conn;
46 struct iscsi_session;
47 struct iscsi_nopin;
48 struct 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 */
56 enum {
57 	TMF_INITIAL,
58 	TMF_QUEUED,
59 	TMF_SUCCESS,
60 	TMF_FAILED,
61 	TMF_TIMEDOUT,
62 	TMF_NOT_FOUND,
63 };
64 
65 /* Connection suspend "bit" */
66 #define ISCSI_SUSPEND_BIT		1
67 
68 #define ISCSI_ITT_MASK			0x1fff
69 #define ISCSI_TOTAL_CMDS_MAX		4096
70 /* this must be a power of two greater than ISCSI_MGMT_CMDS_MAX */
71 #define ISCSI_TOTAL_CMDS_MIN		16
72 #define ISCSI_AGE_SHIFT			28
73 #define ISCSI_AGE_MASK			0xf
74 
75 #define ISCSI_ADDRESS_BUF_LEN		64
76 
77 enum {
78 	/* this is the maximum possible storage for AHSs */
79 	ISCSI_MAX_AHS_SIZE = sizeof(struct iscsi_ecdb_ahdr) +
80 				sizeof(struct iscsi_rlength_ahdr),
81 	ISCSI_DIGEST_SIZE = sizeof(__u32),
82 };
83 
84 
85 enum {
86 	ISCSI_TASK_FREE,
87 	ISCSI_TASK_COMPLETED,
88 	ISCSI_TASK_PENDING,
89 	ISCSI_TASK_RUNNING,
90 	ISCSI_TASK_ABRT_TMF,		/* aborted due to TMF */
91 	ISCSI_TASK_ABRT_SESS_RECOV,	/* aborted due to session recovery */
92 	ISCSI_TASK_REQUEUE_SCSIQ,	/* qcmd requeueing to scsi-ml */
93 };
94 
95 struct iscsi_r2t_info {
96 	__be32			ttt;		/* copied from R2T */
97 	__be32			exp_statsn;	/* copied from R2T */
98 	uint32_t		data_length;	/* copied from R2T */
99 	uint32_t		data_offset;	/* copied from R2T */
100 	int			data_count;	/* DATA-Out payload progress */
101 	int			datasn;
102 	/* LLDs should set/update these values */
103 	int			sent;		/* R2T sequence progress */
104 };
105 
106 struct iscsi_task {
107 	/*
108 	 * Because LLDs allocate their hdr differently, this is a pointer
109 	 * and length to that storage. It must be setup at session
110 	 * creation time.
111 	 */
112 	struct iscsi_hdr	*hdr;
113 	unsigned short		hdr_max;
114 	unsigned short		hdr_len;	/* accumulated size of hdr used */
115 	/* copied values in case we need to send tmfs */
116 	itt_t			hdr_itt;
117 	__be32			cmdsn;
118 	struct scsi_lun		lun;
119 
120 	int			itt;		/* this ITT */
121 
122 	unsigned		imm_count;	/* imm-data (bytes)   */
123 	/* offset in unsolicited stream (bytes); */
124 	struct iscsi_r2t_info	unsol_r2t;
125 	char			*data;		/* mgmt payload */
126 	unsigned		data_count;
127 	struct scsi_cmnd	*sc;		/* associated SCSI cmd*/
128 	struct iscsi_conn	*conn;		/* used connection    */
129 
130 	/* data processing tracking */
131 	unsigned long		last_xfer;
132 	unsigned long		last_timeout;
133 	bool			have_checked_conn;
134 	/* state set/tested under session->lock */
135 	int			state;
136 	atomic_t		refcount;
137 	struct list_head	running;	/* running cmd list */
138 	void			*dd_data;	/* driver/transport data */
139 };
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 
151 /* Connection's states */
152 enum {
153 	ISCSI_CONN_INITIAL_STAGE,
154 	ISCSI_CONN_STARTED,
155 	ISCSI_CONN_STOPPED,
156 	ISCSI_CONN_CLEANUP_WAIT,
157 };
158 
159 struct iscsi_conn {
160 	struct iscsi_cls_conn	*cls_conn;	/* ptr to class connection */
161 	void			*dd_data;	/* iscsi_transport data */
162 	struct iscsi_session	*session;	/* parent session */
163 	/*
164 	 * conn_stop() flag: stop to recover, stop to terminate
165 	 */
166         int			stop_stage;
167 	struct timer_list	transport_timer;
168 	unsigned long		last_recv;
169 	unsigned long		last_ping;
170 	int			ping_timeout;
171 	int			recv_timeout;
172 	struct iscsi_task 	*ping_task;
173 
174 	/* iSCSI connection-wide sequencing */
175 	uint32_t		exp_statsn;
176 
177 	/* control data */
178 	int			id;		/* CID */
179 	int			c_stage;	/* connection state */
180 	/*
181 	 * Preallocated buffer for pdus that have data but do not
182 	 * originate from scsi-ml. We never have two pdus using the
183 	 * buffer at the same time. It is only allocated to
184 	 * the default max recv size because the pdus we support
185 	 * should always fit in this buffer
186 	 */
187 	char			*data;
188 	struct iscsi_task 	*login_task;	/* mtask used for login/text */
189 	struct iscsi_task	*task;		/* xmit task in progress */
190 
191 	/* xmit */
192 	struct list_head	mgmtqueue;	/* mgmt (control) xmit queue */
193 	struct list_head	cmdqueue;	/* data-path cmd queue */
194 	struct list_head	requeue;	/* tasks needing another run */
195 	struct work_struct	xmitwork;	/* per-conn. xmit workqueue */
196 	unsigned long		suspend_tx;	/* suspend Tx */
197 	unsigned long		suspend_rx;	/* suspend Rx */
198 
199 	/* abort */
200 	wait_queue_head_t	ehwait;		/* used in eh_abort() */
201 	struct iscsi_tm		tmhdr;
202 	struct timer_list	tmf_timer;
203 	int			tmf_state;	/* see TMF_INITIAL, etc.*/
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 	/* MIB-statistics */
217 	uint64_t		txdata_octets;
218 	uint64_t		rxdata_octets;
219 	uint32_t		scsicmd_pdus_cnt;
220 	uint32_t		dataout_pdus_cnt;
221 	uint32_t		scsirsp_pdus_cnt;
222 	uint32_t		datain_pdus_cnt;
223 	uint32_t		r2t_pdus_cnt;
224 	uint32_t		tmfcmd_pdus_cnt;
225 	int32_t			tmfrsp_pdus_cnt;
226 
227 	/* custom statistics */
228 	uint32_t		eh_abort_cnt;
229 	uint32_t		fmr_unalign_cnt;
230 };
231 
232 struct iscsi_pool {
233 	struct kfifo		queue;		/* FIFO Queue */
234 	void			**pool;		/* Pool of elements */
235 	int			max;		/* Max number of elements */
236 };
237 
238 /* Session's states */
239 enum {
240 	ISCSI_STATE_FREE = 1,
241 	ISCSI_STATE_LOGGED_IN,
242 	ISCSI_STATE_FAILED,
243 	ISCSI_STATE_TERMINATE,
244 	ISCSI_STATE_IN_RECOVERY,
245 	ISCSI_STATE_RECOVERY_FAILED,
246 	ISCSI_STATE_LOGGING_OUT,
247 };
248 
249 struct iscsi_session {
250 	struct iscsi_cls_session *cls_session;
251 	/*
252 	 * Syncs up the scsi eh thread with the iscsi eh thread when sending
253 	 * task management functions. This must be taken before the session
254 	 * and recv lock.
255 	 */
256 	struct mutex		eh_mutex;
257 
258 	/* iSCSI session-wide sequencing */
259 	uint32_t		cmdsn;
260 	uint32_t		exp_cmdsn;
261 	uint32_t		max_cmdsn;
262 
263 	/* This tracks the reqs queued into the initiator */
264 	uint32_t		queued_cmdsn;
265 
266 	/* configuration */
267 	int			abort_timeout;
268 	int			lu_reset_timeout;
269 	int			tgt_reset_timeout;
270 	int			initial_r2t_en;
271 	unsigned short		max_r2t;
272 	int			imm_data_en;
273 	unsigned		first_burst;
274 	unsigned		max_burst;
275 	int			time2wait;
276 	int			time2retain;
277 	int			pdu_inorder_en;
278 	int			dataseq_inorder_en;
279 	int			erl;
280 	int			fast_abort;
281 	int			tpgt;
282 	char			*username;
283 	char			*username_in;
284 	char			*password;
285 	char			*password_in;
286 	char			*targetname;
287 	char			*targetalias;
288 	char			*ifacename;
289 	char			*initiatorname;
290 	/* control data */
291 	struct iscsi_transport	*tt;
292 	struct Scsi_Host	*host;
293 	struct iscsi_conn	*leadconn;	/* leading connection */
294 	spinlock_t		lock;		/* protects session state, *
295 						 * sequence numbers,       *
296 						 * session resources:      *
297 						 * - cmdpool,		   *
298 						 * - mgmtpool,		   *
299 						 * - r2tpool		   */
300 	int			state;		/* session state           */
301 	int			age;		/* counts session re-opens */
302 
303 	int			scsi_cmds_max; 	/* max scsi commands */
304 	int			cmds_max;	/* size of cmds array */
305 	struct iscsi_task	**cmds;		/* Original Cmds arr */
306 	struct iscsi_pool	cmdpool;	/* PDU's pool */
307 	void			*dd_data;	/* LLD private data */
308 };
309 
310 enum {
311 	ISCSI_HOST_SETUP,
312 	ISCSI_HOST_REMOVED,
313 };
314 
315 struct iscsi_host {
316 	char			*initiatorname;
317 	/* hw address or netdev iscsi connection is bound to */
318 	char			*hwaddress;
319 	char			*netdev;
320 
321 	wait_queue_head_t	session_removal_wq;
322 	/* protects sessions and state */
323 	spinlock_t		lock;
324 	int			num_sessions;
325 	int			state;
326 
327 	struct workqueue_struct	*workq;
328 	char			workq_name[20];
329 };
330 
331 /*
332  * scsi host template
333  */
334 extern int iscsi_change_queue_depth(struct scsi_device *sdev, int depth,
335 				    int reason);
336 extern int iscsi_eh_abort(struct scsi_cmnd *sc);
337 extern int iscsi_eh_recover_target(struct scsi_cmnd *sc);
338 extern int iscsi_eh_session_reset(struct scsi_cmnd *sc);
339 extern int iscsi_eh_device_reset(struct scsi_cmnd *sc);
340 extern int iscsi_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *sc);
341 
342 /*
343  * iSCSI host helpers.
344  */
345 #define iscsi_host_priv(_shost) \
346 	(shost_priv(_shost) + sizeof(struct iscsi_host))
347 
348 extern int iscsi_host_set_param(struct Scsi_Host *shost,
349 				enum iscsi_host_param param, char *buf,
350 				int buflen);
351 extern int iscsi_host_get_param(struct Scsi_Host *shost,
352 				enum iscsi_host_param param, char *buf);
353 extern int iscsi_host_add(struct Scsi_Host *shost, struct device *pdev);
354 extern struct Scsi_Host *iscsi_host_alloc(struct scsi_host_template *sht,
355 					  int dd_data_size,
356 					  bool xmit_can_sleep);
357 extern void iscsi_host_remove(struct Scsi_Host *shost);
358 extern void iscsi_host_free(struct Scsi_Host *shost);
359 extern int iscsi_target_alloc(struct scsi_target *starget);
360 
361 /*
362  * session management
363  */
364 extern struct iscsi_cls_session *
365 iscsi_session_setup(struct iscsi_transport *, struct Scsi_Host *shost,
366 		    uint16_t, int, int, uint32_t, unsigned int);
367 extern void iscsi_session_teardown(struct iscsi_cls_session *);
368 extern void iscsi_session_recovery_timedout(struct iscsi_cls_session *);
369 extern int iscsi_set_param(struct iscsi_cls_conn *cls_conn,
370 			   enum iscsi_param param, char *buf, int buflen);
371 extern int iscsi_session_get_param(struct iscsi_cls_session *cls_session,
372 				   enum iscsi_param param, char *buf);
373 
374 #define iscsi_session_printk(prefix, _sess, fmt, a...)	\
375 	iscsi_cls_session_printk(prefix, _sess->cls_session, fmt, ##a)
376 
377 /*
378  * connection management
379  */
380 extern struct iscsi_cls_conn *iscsi_conn_setup(struct iscsi_cls_session *,
381 					       int, uint32_t);
382 extern void iscsi_conn_teardown(struct iscsi_cls_conn *);
383 extern int iscsi_conn_start(struct iscsi_cls_conn *);
384 extern void iscsi_conn_stop(struct iscsi_cls_conn *, int);
385 extern int iscsi_conn_bind(struct iscsi_cls_session *, struct iscsi_cls_conn *,
386 			   int);
387 extern void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err);
388 extern void iscsi_session_failure(struct iscsi_session *session,
389 				  enum iscsi_err err);
390 extern int iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
391 				enum iscsi_param param, char *buf);
392 extern int iscsi_conn_get_addr_param(struct sockaddr_storage *addr,
393 				     enum iscsi_param param, char *buf);
394 extern void iscsi_suspend_tx(struct iscsi_conn *conn);
395 extern void iscsi_suspend_queue(struct iscsi_conn *conn);
396 extern void iscsi_conn_queue_work(struct iscsi_conn *conn);
397 
398 #define iscsi_conn_printk(prefix, _c, fmt, a...) \
399 	iscsi_cls_conn_printk(prefix, ((struct iscsi_conn *)_c)->cls_conn, \
400 			      fmt, ##a)
401 
402 /*
403  * pdu and task processing
404  */
405 extern void iscsi_update_cmdsn(struct iscsi_session *, struct iscsi_nopin *);
406 extern void iscsi_prep_data_out_pdu(struct iscsi_task *task,
407 				    struct iscsi_r2t_info *r2t,
408 				    struct iscsi_data *hdr);
409 extern int iscsi_conn_send_pdu(struct iscsi_cls_conn *, struct iscsi_hdr *,
410 				char *, uint32_t);
411 extern int iscsi_complete_pdu(struct iscsi_conn *, struct iscsi_hdr *,
412 			      char *, int);
413 extern int __iscsi_complete_pdu(struct iscsi_conn *, struct iscsi_hdr *,
414 				char *, int);
415 extern int iscsi_verify_itt(struct iscsi_conn *, itt_t);
416 extern struct iscsi_task *iscsi_itt_to_ctask(struct iscsi_conn *, itt_t);
417 extern struct iscsi_task *iscsi_itt_to_task(struct iscsi_conn *, itt_t);
418 extern void iscsi_requeue_task(struct iscsi_task *task);
419 extern void iscsi_put_task(struct iscsi_task *task);
420 extern void __iscsi_put_task(struct iscsi_task *task);
421 extern void __iscsi_get_task(struct iscsi_task *task);
422 extern void iscsi_complete_scsi_task(struct iscsi_task *task,
423 				     uint32_t exp_cmdsn, uint32_t max_cmdsn);
424 
425 /*
426  * generic helpers
427  */
428 extern void iscsi_pool_free(struct iscsi_pool *);
429 extern int iscsi_pool_init(struct iscsi_pool *, int, void ***, int);
430 extern int iscsi_switch_str_param(char **, char *);
431 
432 /*
433  * inline functions to deal with padding.
434  */
435 static inline unsigned int
iscsi_padded(unsigned int len)436 iscsi_padded(unsigned int len)
437 {
438 	return (len + ISCSI_PAD_LEN - 1) & ~(ISCSI_PAD_LEN - 1);
439 }
440 
441 static inline unsigned int
iscsi_padding(unsigned int len)442 iscsi_padding(unsigned int len)
443 {
444 	len &= (ISCSI_PAD_LEN - 1);
445 	if (len)
446 		len = ISCSI_PAD_LEN - len;
447 	return len;
448 }
449 
450 #endif
451