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
24 struct scsi_transport_template;
25 struct scsi_host_template;
26 struct scsi_device;
27 struct Scsi_Host;
28 struct scsi_target;
29 struct scsi_cmnd;
30 struct socket;
31 struct iscsi_transport;
32 struct iscsi_cls_session;
33 struct iscsi_cls_conn;
34 struct iscsi_session;
35 struct iscsi_nopin;
36 struct 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 */
44 enum {
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
67 enum {
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
75 enum {
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
85 struct 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
96 struct 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
iscsi_task_has_unsol_data(struct iscsi_task * task)138 static 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
iscsi_next_hdr(struct iscsi_task * task)143 static inline void* iscsi_next_hdr(struct iscsi_task *task)
144 {
145 return (void*)task->hdr + task->hdr_len;
146 }
147
iscsi_task_is_completed(struct iscsi_task * task)148 static 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 /* Connection's states */
156 enum {
157 ISCSI_CONN_INITIAL_STAGE,
158 ISCSI_CONN_STARTED,
159 ISCSI_CONN_STOPPED,
160 ISCSI_CONN_CLEANUP_WAIT,
161 };
162
163 struct iscsi_conn {
164 struct iscsi_cls_conn *cls_conn; /* ptr to class connection */
165 void *dd_data; /* iscsi_transport data */
166 struct iscsi_session *session; /* parent session */
167 /*
168 * conn_stop() flag: stop to recover, stop to terminate
169 */
170 int stop_stage;
171 struct timer_list transport_timer;
172 unsigned long last_recv;
173 unsigned long last_ping;
174 int ping_timeout;
175 int recv_timeout;
176 struct iscsi_task *ping_task;
177
178 /* iSCSI connection-wide sequencing */
179 uint32_t exp_statsn;
180 uint32_t statsn;
181
182 /* control data */
183 int id; /* CID */
184 int c_stage; /* connection state */
185 /*
186 * Preallocated buffer for pdus that have data but do not
187 * originate from scsi-ml. We never have two pdus using the
188 * buffer at the same time. It is only allocated to
189 * the default max recv size because the pdus we support
190 * should always fit in this buffer
191 */
192 char *data;
193 struct iscsi_task *login_task; /* mtask used for login/text */
194 struct iscsi_task *task; /* xmit task in progress */
195
196 /* xmit */
197 /* items must be added/deleted under frwd lock */
198 struct list_head mgmtqueue; /* mgmt (control) xmit queue */
199 struct list_head cmdqueue; /* data-path cmd queue */
200 struct list_head requeue; /* tasks needing another run */
201 struct work_struct xmitwork; /* per-conn. xmit workqueue */
202 unsigned long suspend_tx; /* suspend Tx */
203 unsigned long suspend_rx; /* suspend Rx */
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 unsigned max_segment_size;
217 unsigned tcp_xmit_wsf;
218 unsigned tcp_recv_wsf;
219 uint16_t keepalive_tmo;
220 uint16_t local_port;
221 uint8_t tcp_timestamp_stat;
222 uint8_t tcp_nagle_disable;
223 uint8_t tcp_wsf_disable;
224 uint8_t tcp_timer_scale;
225 uint8_t tcp_timestamp_en;
226 uint8_t fragment_disable;
227 uint8_t ipv4_tos;
228 uint8_t ipv6_traffic_class;
229 uint8_t ipv6_flow_label;
230 uint8_t is_fw_assigned_ipv6;
231 char *local_ipaddr;
232
233 /* MIB-statistics */
234 uint64_t txdata_octets;
235 uint64_t rxdata_octets;
236 uint32_t scsicmd_pdus_cnt;
237 uint32_t dataout_pdus_cnt;
238 uint32_t scsirsp_pdus_cnt;
239 uint32_t datain_pdus_cnt;
240 uint32_t r2t_pdus_cnt;
241 uint32_t tmfcmd_pdus_cnt;
242 int32_t tmfrsp_pdus_cnt;
243
244 /* custom statistics */
245 uint32_t eh_abort_cnt;
246 uint32_t fmr_unalign_cnt;
247 };
248
249 struct iscsi_pool {
250 struct kfifo queue; /* FIFO Queue */
251 void **pool; /* Pool of elements */
252 int max; /* Max number of elements */
253 };
254
255 /* Session's states */
256 enum {
257 ISCSI_STATE_FREE = 1,
258 ISCSI_STATE_LOGGED_IN,
259 ISCSI_STATE_FAILED,
260 ISCSI_STATE_TERMINATE,
261 ISCSI_STATE_IN_RECOVERY,
262 ISCSI_STATE_RECOVERY_FAILED,
263 ISCSI_STATE_LOGGING_OUT,
264 };
265
266 struct iscsi_session {
267 struct iscsi_cls_session *cls_session;
268 /*
269 * Syncs up the scsi eh thread with the iscsi eh thread when sending
270 * task management functions. This must be taken before the session
271 * and recv lock.
272 */
273 struct mutex eh_mutex;
274 /* abort */
275 wait_queue_head_t ehwait; /* used in eh_abort() */
276 struct iscsi_tm tmhdr;
277 struct timer_list tmf_timer;
278 int tmf_state; /* see TMF_INITIAL, etc.*/
279 struct iscsi_task *running_aborted_task;
280
281 /* iSCSI session-wide sequencing */
282 uint32_t cmdsn;
283 uint32_t exp_cmdsn;
284 uint32_t max_cmdsn;
285
286 /* This tracks the reqs queued into the initiator */
287 uint32_t queued_cmdsn;
288
289 /* configuration */
290 int abort_timeout;
291 int lu_reset_timeout;
292 int tgt_reset_timeout;
293 int initial_r2t_en;
294 unsigned short max_r2t;
295 int imm_data_en;
296 unsigned first_burst;
297 unsigned max_burst;
298 int time2wait;
299 int time2retain;
300 int pdu_inorder_en;
301 int dataseq_inorder_en;
302 int erl;
303 int fast_abort;
304 int tpgt;
305 char *username;
306 char *username_in;
307 char *password;
308 char *password_in;
309 char *targetname;
310 char *targetalias;
311 char *ifacename;
312 char *initiatorname;
313 char *boot_root;
314 char *boot_nic;
315 char *boot_target;
316 char *portal_type;
317 char *discovery_parent_type;
318 uint16_t discovery_parent_idx;
319 uint16_t def_taskmgmt_tmo;
320 uint16_t tsid;
321 uint8_t auto_snd_tgt_disable;
322 uint8_t discovery_sess;
323 uint8_t chap_auth_en;
324 uint8_t discovery_logout_en;
325 uint8_t bidi_chap_en;
326 uint8_t discovery_auth_optional;
327 uint8_t isid[ISID_SIZE];
328
329 /* control data */
330 struct iscsi_transport *tt;
331 struct Scsi_Host *host;
332 struct iscsi_conn *leadconn; /* leading connection */
333 /* Between the forward and the backward locks exists a strict locking
334 * hierarchy. The mutual exclusion zone protected by the forward lock
335 * can enclose the mutual exclusion zone protected by the backward lock
336 * but not vice versa.
337 */
338 spinlock_t frwd_lock; /* protects session state, *
339 * cmdsn, queued_cmdsn *
340 * session resources: *
341 * - cmdpool kfifo_out , *
342 * - mgmtpool, queues */
343 spinlock_t back_lock; /* protects cmdsn_exp *
344 * cmdsn_max, *
345 * cmdpool kfifo_in */
346 int state; /* session state */
347 int age; /* counts session re-opens */
348
349 int scsi_cmds_max; /* max scsi commands */
350 int cmds_max; /* size of cmds array */
351 struct iscsi_task **cmds; /* Original Cmds arr */
352 struct iscsi_pool cmdpool; /* PDU's pool */
353 void *dd_data; /* LLD private data */
354 };
355
356 enum {
357 ISCSI_HOST_SETUP,
358 ISCSI_HOST_REMOVED,
359 };
360
361 struct iscsi_host {
362 char *initiatorname;
363 /* hw address or netdev iscsi connection is bound to */
364 char *hwaddress;
365 char *netdev;
366
367 wait_queue_head_t session_removal_wq;
368 /* protects sessions and state */
369 spinlock_t lock;
370 int num_sessions;
371 int state;
372
373 struct workqueue_struct *workq;
374 char workq_name[20];
375 };
376
377 /*
378 * scsi host template
379 */
380 extern int iscsi_eh_abort(struct scsi_cmnd *sc);
381 extern int iscsi_eh_recover_target(struct scsi_cmnd *sc);
382 extern int iscsi_eh_session_reset(struct scsi_cmnd *sc);
383 extern int iscsi_eh_device_reset(struct scsi_cmnd *sc);
384 extern int iscsi_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *sc);
385 extern enum blk_eh_timer_return iscsi_eh_cmd_timed_out(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
393 extern int iscsi_host_set_param(struct Scsi_Host *shost,
394 enum iscsi_host_param param, char *buf,
395 int buflen);
396 extern int iscsi_host_get_param(struct Scsi_Host *shost,
397 enum iscsi_host_param param, char *buf);
398 extern int iscsi_host_add(struct Scsi_Host *shost, struct device *pdev);
399 extern struct Scsi_Host *iscsi_host_alloc(struct scsi_host_template *sht,
400 int dd_data_size,
401 bool xmit_can_sleep);
402 extern void iscsi_host_remove(struct Scsi_Host *shost);
403 extern void iscsi_host_free(struct Scsi_Host *shost);
404 extern int iscsi_target_alloc(struct scsi_target *starget);
405 extern int iscsi_host_get_max_scsi_cmds(struct Scsi_Host *shost,
406 uint16_t requested_cmds_max);
407
408 /*
409 * session management
410 */
411 extern struct iscsi_cls_session *
412 iscsi_session_setup(struct iscsi_transport *, struct Scsi_Host *shost,
413 uint16_t, int, int, uint32_t, unsigned int);
414 extern void iscsi_session_teardown(struct iscsi_cls_session *);
415 extern void iscsi_session_recovery_timedout(struct iscsi_cls_session *);
416 extern int iscsi_set_param(struct iscsi_cls_conn *cls_conn,
417 enum iscsi_param param, char *buf, int buflen);
418 extern int iscsi_session_get_param(struct iscsi_cls_session *cls_session,
419 enum iscsi_param param, char *buf);
420
421 #define iscsi_session_printk(prefix, _sess, fmt, a...) \
422 iscsi_cls_session_printk(prefix, _sess->cls_session, fmt, ##a)
423
424 /*
425 * connection management
426 */
427 extern struct iscsi_cls_conn *iscsi_conn_setup(struct iscsi_cls_session *,
428 int, uint32_t);
429 extern void iscsi_conn_teardown(struct iscsi_cls_conn *);
430 extern int iscsi_conn_start(struct iscsi_cls_conn *);
431 extern void iscsi_conn_stop(struct iscsi_cls_conn *, int);
432 extern int iscsi_conn_bind(struct iscsi_cls_session *, struct iscsi_cls_conn *,
433 int);
434 extern void iscsi_conn_unbind(struct iscsi_cls_conn *cls_conn, bool is_active);
435 extern void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err);
436 extern void iscsi_session_failure(struct iscsi_session *session,
437 enum iscsi_err err);
438 extern int iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
439 enum iscsi_param param, char *buf);
440 extern int iscsi_conn_get_addr_param(struct sockaddr_storage *addr,
441 enum iscsi_param param, char *buf);
442 extern void iscsi_suspend_tx(struct iscsi_conn *conn);
443 extern void iscsi_suspend_queue(struct iscsi_conn *conn);
444 extern void iscsi_conn_queue_work(struct iscsi_conn *conn);
445
446 #define iscsi_conn_printk(prefix, _c, fmt, a...) \
447 iscsi_cls_conn_printk(prefix, ((struct iscsi_conn *)_c)->cls_conn, \
448 fmt, ##a)
449
450 /*
451 * pdu and task processing
452 */
453 extern void iscsi_update_cmdsn(struct iscsi_session *, struct iscsi_nopin *);
454 extern void iscsi_prep_data_out_pdu(struct iscsi_task *task,
455 struct iscsi_r2t_info *r2t,
456 struct iscsi_data *hdr);
457 extern int iscsi_conn_send_pdu(struct iscsi_cls_conn *, struct iscsi_hdr *,
458 char *, uint32_t);
459 extern int iscsi_complete_pdu(struct iscsi_conn *, struct iscsi_hdr *,
460 char *, int);
461 extern int __iscsi_complete_pdu(struct iscsi_conn *, struct iscsi_hdr *,
462 char *, int);
463 extern int iscsi_verify_itt(struct iscsi_conn *, itt_t);
464 extern struct iscsi_task *iscsi_itt_to_ctask(struct iscsi_conn *, itt_t);
465 extern struct iscsi_task *iscsi_itt_to_task(struct iscsi_conn *, itt_t);
466 extern void iscsi_requeue_task(struct iscsi_task *task);
467 extern void iscsi_put_task(struct iscsi_task *task);
468 extern void __iscsi_put_task(struct iscsi_task *task);
469 extern void __iscsi_get_task(struct iscsi_task *task);
470 extern void iscsi_complete_scsi_task(struct iscsi_task *task,
471 uint32_t exp_cmdsn, uint32_t max_cmdsn);
472
473 /*
474 * generic helpers
475 */
476 extern void iscsi_pool_free(struct iscsi_pool *);
477 extern int iscsi_pool_init(struct iscsi_pool *, int, void ***, int);
478 extern int iscsi_switch_str_param(char **, char *);
479
480 /*
481 * inline functions to deal with padding.
482 */
483 static inline unsigned int
iscsi_padded(unsigned int len)484 iscsi_padded(unsigned int len)
485 {
486 return (len + ISCSI_PAD_LEN - 1) & ~(ISCSI_PAD_LEN - 1);
487 }
488
489 static inline unsigned int
iscsi_padding(unsigned int len)490 iscsi_padding(unsigned int len)
491 {
492 len &= (ISCSI_PAD_LEN - 1);
493 if (len)
494 len = ISCSI_PAD_LEN - len;
495 return len;
496 }
497
498 #endif
499