xref: /openbmc/linux/include/scsi/libiscsi.h (revision a1e58bbd)
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/mutex.h>
28 #include <linux/timer.h>
29 #include <linux/workqueue.h>
30 #include <scsi/iscsi_proto.h>
31 #include <scsi/iscsi_if.h>
32 
33 struct scsi_transport_template;
34 struct scsi_device;
35 struct Scsi_Host;
36 struct scsi_cmnd;
37 struct socket;
38 struct iscsi_transport;
39 struct iscsi_cls_session;
40 struct iscsi_cls_conn;
41 struct iscsi_session;
42 struct iscsi_nopin;
43 
44 /* #define DEBUG_SCSI */
45 #ifdef DEBUG_SCSI
46 #define debug_scsi(fmt...) printk(KERN_INFO "iscsi: " fmt)
47 #else
48 #define debug_scsi(fmt...)
49 #endif
50 
51 #define ISCSI_DEF_XMIT_CMDS_MAX	128	/* must be power of 2 */
52 #define ISCSI_MGMT_CMDS_MAX	16	/* must be power of 2 */
53 
54 #define ISCSI_MGMT_ITT_OFFSET	0xa00
55 
56 #define ISCSI_DEF_CMD_PER_LUN		32
57 #define ISCSI_MAX_CMD_PER_LUN		128
58 
59 /* Task Mgmt states */
60 enum {
61 	TMF_INITIAL,
62 	TMF_QUEUED,
63 	TMF_SUCCESS,
64 	TMF_FAILED,
65 	TMF_TIMEDOUT,
66 	TMF_NOT_FOUND,
67 };
68 
69 /* Connection suspend "bit" */
70 #define ISCSI_SUSPEND_BIT		1
71 
72 #define ISCSI_ITT_MASK			(0xfff)
73 #define ISCSI_AGE_SHIFT			28
74 #define ISCSI_AGE_MASK			(0xf << ISCSI_AGE_SHIFT)
75 
76 #define ISCSI_ADDRESS_BUF_LEN		64
77 
78 enum {
79 	/* this is the maximum possible storage for AHSs */
80 	ISCSI_MAX_AHS_SIZE = sizeof(struct iscsi_ecdb_ahdr) +
81 				sizeof(struct iscsi_rlength_ahdr),
82 	ISCSI_DIGEST_SIZE = sizeof(__u32),
83 };
84 
85 struct iscsi_mgmt_task {
86 	/*
87 	 * Becuae LLDs allocate their hdr differently, this is a pointer to
88 	 * that storage. It must be setup at session creation time.
89 	 */
90 	struct iscsi_hdr	*hdr;
91 	char			*data;		/* mgmt payload */
92 	unsigned		data_count;	/* counts data to be sent */
93 	uint32_t		itt;		/* this ITT */
94 	void			*dd_data;	/* driver/transport data */
95 	struct list_head	running;
96 };
97 
98 enum {
99 	ISCSI_TASK_COMPLETED,
100 	ISCSI_TASK_PENDING,
101 	ISCSI_TASK_RUNNING,
102 };
103 
104 struct iscsi_cmd_task {
105 	/*
106 	 * Because LLDs allocate their hdr differently, this is a pointer
107 	 * and length to that storage. It must be setup at session
108 	 * creation time.
109 	 */
110 	struct iscsi_cmd	*hdr;
111 	unsigned short		hdr_max;
112 	unsigned short		hdr_len;	/* accumulated size of hdr used */
113 	int			itt;		/* this ITT */
114 
115 	uint32_t		unsol_datasn;
116 	unsigned		imm_count;	/* imm-data (bytes)   */
117 	unsigned		unsol_count;	/* unsolicited (bytes)*/
118 	/* offset in unsolicited stream (bytes); */
119 	unsigned		unsol_offset;
120 	unsigned		data_count;	/* remaining Data-Out */
121 	struct scsi_cmnd	*sc;		/* associated SCSI cmd*/
122 	struct iscsi_conn	*conn;		/* used connection    */
123 
124 	/* state set/tested under session->lock */
125 	int			state;
126 	atomic_t		refcount;
127 	struct list_head	running;	/* running cmd list */
128 	void			*dd_data;	/* driver/transport data */
129 };
130 
131 static inline void* iscsi_next_hdr(struct iscsi_cmd_task *ctask)
132 {
133 	return (void*)ctask->hdr + ctask->hdr_len;
134 }
135 
136 /* Connection's states */
137 enum {
138 	ISCSI_CONN_INITIAL_STAGE,
139 	ISCSI_CONN_STARTED,
140 	ISCSI_CONN_STOPPED,
141 	ISCSI_CONN_CLEANUP_WAIT,
142 };
143 
144 struct iscsi_conn {
145 	struct iscsi_cls_conn	*cls_conn;	/* ptr to class connection */
146 	void			*dd_data;	/* iscsi_transport data */
147 	struct iscsi_session	*session;	/* parent session */
148 	/*
149 	 * LLDs should set this lock. It protects the transport recv
150 	 * code
151 	 */
152 	rwlock_t		*recv_lock;
153 	/*
154 	 * conn_stop() flag: stop to recover, stop to terminate
155 	 */
156         int			stop_stage;
157 	struct timer_list	transport_timer;
158 	unsigned long		last_recv;
159 	unsigned long		last_ping;
160 	int			ping_timeout;
161 	int			recv_timeout;
162 	struct iscsi_mgmt_task	*ping_mtask;
163 
164 	/* iSCSI connection-wide sequencing */
165 	uint32_t		exp_statsn;
166 
167 	/* control data */
168 	int			id;		/* CID */
169 	int			c_stage;	/* connection state */
170 	/*
171 	 * Preallocated buffer for pdus that have data but do not
172 	 * originate from scsi-ml. We never have two pdus using the
173 	 * buffer at the same time. It is only allocated to
174 	 * the default max recv size because the pdus we support
175 	 * should always fit in this buffer
176 	 */
177 	char			*data;
178 	struct iscsi_mgmt_task	*login_mtask;	/* mtask used for login/text */
179 	struct iscsi_mgmt_task	*mtask;		/* xmit mtask in progress */
180 	struct iscsi_cmd_task	*ctask;		/* xmit ctask in progress */
181 
182 	/* xmit */
183 	struct list_head	mgmtqueue;	/* mgmt (control) xmit queue */
184 	struct list_head	mgmt_run_list;	/* list of control tasks */
185 	struct list_head	xmitqueue;	/* data-path cmd queue */
186 	struct list_head	run_list;	/* list of cmds in progress */
187 	struct list_head	requeue;	/* tasks needing another run */
188 	struct work_struct	xmitwork;	/* per-conn. xmit workqueue */
189 	unsigned long		suspend_tx;	/* suspend Tx */
190 	unsigned long		suspend_rx;	/* suspend Rx */
191 
192 	/* abort */
193 	wait_queue_head_t	ehwait;		/* used in eh_abort() */
194 	struct iscsi_tm		tmhdr;
195 	struct timer_list	tmf_timer;
196 	int			tmf_state;	/* see TMF_INITIAL, etc.*/
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 	/* remote portal currently connected to */
209 	int			portal_port;
210 	char			portal_address[ISCSI_ADDRESS_BUF_LEN];
211 	/* local address */
212 	int			local_port;
213 	char			local_address[ISCSI_ADDRESS_BUF_LEN];
214 
215 	/* MIB-statistics */
216 	uint64_t		txdata_octets;
217 	uint64_t		rxdata_octets;
218 	uint32_t		scsicmd_pdus_cnt;
219 	uint32_t		dataout_pdus_cnt;
220 	uint32_t		scsirsp_pdus_cnt;
221 	uint32_t		datain_pdus_cnt;
222 	uint32_t		r2t_pdus_cnt;
223 	uint32_t		tmfcmd_pdus_cnt;
224 	int32_t			tmfrsp_pdus_cnt;
225 
226 	/* custom statistics */
227 	uint32_t		eh_abort_cnt;
228 };
229 
230 struct iscsi_pool {
231 	struct kfifo		*queue;		/* FIFO Queue */
232 	void			**pool;		/* Pool of elements */
233 	int			max;		/* Max number of elements */
234 };
235 
236 /* Session's states */
237 enum {
238 	ISCSI_STATE_FREE = 1,
239 	ISCSI_STATE_LOGGED_IN,
240 	ISCSI_STATE_FAILED,
241 	ISCSI_STATE_TERMINATE,
242 	ISCSI_STATE_IN_RECOVERY,
243 	ISCSI_STATE_RECOVERY_FAILED,
244 	ISCSI_STATE_LOGGING_OUT,
245 };
246 
247 struct iscsi_session {
248 	/*
249 	 * Syncs up the scsi eh thread with the iscsi eh thread when sending
250 	 * task management functions. This must be taken before the session
251 	 * and recv lock.
252 	 */
253 	struct mutex		eh_mutex;
254 
255 	/* iSCSI session-wide sequencing */
256 	uint32_t		cmdsn;
257 	uint32_t		exp_cmdsn;
258 	uint32_t		max_cmdsn;
259 
260 	/* This tracks the reqs queued into the initiator */
261 	uint32_t		queued_cmdsn;
262 
263 	/* configuration */
264 	int			abort_timeout;
265 	int			lu_reset_timeout;
266 	int			initial_r2t_en;
267 	unsigned		max_r2t;
268 	int			imm_data_en;
269 	unsigned		first_burst;
270 	unsigned		max_burst;
271 	int			time2wait;
272 	int			time2retain;
273 	int			pdu_inorder_en;
274 	int			dataseq_inorder_en;
275 	int			erl;
276 	int			fast_abort;
277 	int			tpgt;
278 	char			*username;
279 	char			*username_in;
280 	char			*password;
281 	char			*password_in;
282 	char			*targetname;
283 	char			*initiatorname;
284 	/* hw address or netdev iscsi connection is bound to */
285 	char			*hwaddress;
286 	char			*netdev;
287 	/* control data */
288 	struct iscsi_transport	*tt;
289 	struct Scsi_Host	*host;
290 	struct iscsi_conn	*leadconn;	/* leading connection */
291 	spinlock_t		lock;		/* protects session state, *
292 						 * sequence numbers,       *
293 						 * session resources:      *
294 						 * - cmdpool,		   *
295 						 * - mgmtpool,		   *
296 						 * - r2tpool		   */
297 	int			state;		/* session state           */
298 	int			age;		/* counts session re-opens */
299 
300 	int			cmds_max;	/* size of cmds array */
301 	struct iscsi_cmd_task	**cmds;		/* Original Cmds arr */
302 	struct iscsi_pool	cmdpool;	/* PDU's pool */
303 	int			mgmtpool_max;	/* size of mgmt array */
304 	struct iscsi_mgmt_task	**mgmt_cmds;	/* Original mgmt arr */
305 	struct iscsi_pool	mgmtpool;	/* Mgmt PDU's pool */
306 };
307 
308 /*
309  * scsi host template
310  */
311 extern int iscsi_change_queue_depth(struct scsi_device *sdev, int depth);
312 extern int iscsi_eh_abort(struct scsi_cmnd *sc);
313 extern int iscsi_eh_host_reset(struct scsi_cmnd *sc);
314 extern int iscsi_eh_device_reset(struct scsi_cmnd *sc);
315 extern int iscsi_queuecommand(struct scsi_cmnd *sc,
316 			      void (*done)(struct scsi_cmnd *));
317 
318 
319 /*
320  * iSCSI host helpers.
321  */
322 extern int iscsi_host_set_param(struct Scsi_Host *shost,
323 				enum iscsi_host_param param, char *buf,
324 				int buflen);
325 extern int iscsi_host_get_param(struct Scsi_Host *shost,
326 				enum iscsi_host_param param, char *buf);
327 
328 /*
329  * session management
330  */
331 extern struct iscsi_cls_session *
332 iscsi_session_setup(struct iscsi_transport *, struct scsi_transport_template *,
333 		    uint16_t, uint16_t, int, int, uint32_t, uint32_t *);
334 extern void iscsi_session_teardown(struct iscsi_cls_session *);
335 extern struct iscsi_session *class_to_transport_session(struct iscsi_cls_session *);
336 extern void iscsi_session_recovery_timedout(struct iscsi_cls_session *);
337 extern int iscsi_set_param(struct iscsi_cls_conn *cls_conn,
338 			   enum iscsi_param param, char *buf, int buflen);
339 extern int iscsi_session_get_param(struct iscsi_cls_session *cls_session,
340 				   enum iscsi_param param, char *buf);
341 
342 #define session_to_cls(_sess) \
343 	hostdata_session(_sess->host->hostdata)
344 
345 #define iscsi_session_printk(prefix, _sess, fmt, a...)	\
346 	iscsi_cls_session_printk(prefix,		\
347 		(struct iscsi_cls_session *)session_to_cls(_sess), fmt, ##a)
348 
349 /*
350  * connection management
351  */
352 extern struct iscsi_cls_conn *iscsi_conn_setup(struct iscsi_cls_session *,
353 					       uint32_t);
354 extern void iscsi_conn_teardown(struct iscsi_cls_conn *);
355 extern int iscsi_conn_start(struct iscsi_cls_conn *);
356 extern void iscsi_conn_stop(struct iscsi_cls_conn *, int);
357 extern int iscsi_conn_bind(struct iscsi_cls_session *, struct iscsi_cls_conn *,
358 			   int);
359 extern void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err);
360 extern int iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
361 				enum iscsi_param param, char *buf);
362 
363 #define iscsi_conn_printk(prefix, _c, fmt, a...) \
364 	iscsi_cls_conn_printk(prefix, _c->cls_conn, fmt, ##a)
365 
366 /*
367  * pdu and task processing
368  */
369 extern void iscsi_update_cmdsn(struct iscsi_session *, struct iscsi_nopin *);
370 extern void iscsi_prep_unsolicit_data_pdu(struct iscsi_cmd_task *,
371 					struct iscsi_data *hdr);
372 extern int iscsi_conn_send_pdu(struct iscsi_cls_conn *, struct iscsi_hdr *,
373 				char *, uint32_t);
374 extern int iscsi_complete_pdu(struct iscsi_conn *, struct iscsi_hdr *,
375 			      char *, int);
376 extern int iscsi_verify_itt(struct iscsi_conn *, struct iscsi_hdr *,
377 			    uint32_t *);
378 extern void iscsi_requeue_ctask(struct iscsi_cmd_task *ctask);
379 extern void iscsi_free_mgmt_task(struct iscsi_conn *conn,
380 				 struct iscsi_mgmt_task *mtask);
381 
382 /*
383  * generic helpers
384  */
385 extern void iscsi_pool_free(struct iscsi_pool *);
386 extern int iscsi_pool_init(struct iscsi_pool *, int, void ***, int);
387 
388 /*
389  * inline functions to deal with padding.
390  */
391 static inline unsigned int
392 iscsi_padded(unsigned int len)
393 {
394 	return (len + ISCSI_PAD_LEN - 1) & ~(ISCSI_PAD_LEN - 1);
395 }
396 
397 static inline unsigned int
398 iscsi_padding(unsigned int len)
399 {
400 	len &= (ISCSI_PAD_LEN - 1);
401 	if (len)
402 		len = ISCSI_PAD_LEN - len;
403 	return len;
404 }
405 
406 #endif
407