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 flags */
56 #define ISCSI_CONN_FLAG_SUSPEND_TX 0
57 #define ISCSI_CONN_FLAG_SUSPEND_RX 1
58 #define ISCSI_CONN_FLAG_BOUND 2
59
60 #define ISCSI_ITT_MASK 0x1fff
61 #define ISCSI_TOTAL_CMDS_MAX 4096
62 /* this must be a power of two greater than ISCSI_MGMT_CMDS_MAX */
63 #define ISCSI_TOTAL_CMDS_MIN 16
64 #define ISCSI_AGE_SHIFT 28
65 #define ISCSI_AGE_MASK 0xf
66
67 #define ISCSI_ADDRESS_BUF_LEN 64
68
69 enum {
70 /* this is the maximum possible storage for AHSs */
71 ISCSI_MAX_AHS_SIZE = sizeof(struct iscsi_ecdb_ahdr) +
72 sizeof(struct iscsi_rlength_ahdr),
73 ISCSI_DIGEST_SIZE = sizeof(__u32),
74 };
75
76
77 enum {
78 ISCSI_TASK_FREE,
79 ISCSI_TASK_COMPLETED,
80 ISCSI_TASK_PENDING,
81 ISCSI_TASK_RUNNING,
82 ISCSI_TASK_ABRT_TMF, /* aborted due to TMF */
83 ISCSI_TASK_ABRT_SESS_RECOV, /* aborted due to session recovery */
84 ISCSI_TASK_REQUEUE_SCSIQ, /* qcmd requeueing to scsi-ml */
85 };
86
87 struct iscsi_r2t_info {
88 __be32 ttt; /* copied from R2T */
89 __be32 exp_statsn; /* copied from R2T */
90 uint32_t data_length; /* copied from R2T */
91 uint32_t data_offset; /* copied from R2T */
92 int data_count; /* DATA-Out payload progress */
93 int datasn;
94 /* LLDs should set/update these values */
95 int sent; /* R2T sequence progress */
96 };
97
98 struct iscsi_task {
99 /*
100 * Because LLDs allocate their hdr differently, this is a pointer
101 * and length to that storage. It must be setup at session
102 * creation time.
103 */
104 struct iscsi_hdr *hdr;
105 unsigned short hdr_max;
106 unsigned short hdr_len; /* accumulated size of hdr used */
107 /* copied values in case we need to send tmfs */
108 itt_t hdr_itt;
109 __be32 cmdsn;
110 struct scsi_lun lun;
111
112 int itt; /* this ITT */
113
114 unsigned imm_count; /* imm-data (bytes) */
115 /* offset in unsolicited stream (bytes); */
116 struct iscsi_r2t_info unsol_r2t;
117 char *data; /* mgmt payload */
118 unsigned data_count;
119 struct scsi_cmnd *sc; /* associated SCSI cmd*/
120 struct iscsi_conn *conn; /* used connection */
121
122 /* data processing tracking */
123 unsigned long last_xfer;
124 unsigned long last_timeout;
125 bool have_checked_conn;
126
127 /* T10 protection information */
128 bool protected;
129
130 /* state set/tested under session->lock */
131 int state;
132 refcount_t refcount;
133 struct list_head running; /* running cmd list */
134 void *dd_data; /* driver/transport data */
135 };
136
137 /* invalid scsi_task pointer */
138 #define INVALID_SCSI_TASK (struct iscsi_task *)-1l
139
iscsi_task_has_unsol_data(struct iscsi_task * task)140 static inline int iscsi_task_has_unsol_data(struct iscsi_task *task)
141 {
142 return task->unsol_r2t.data_length > task->unsol_r2t.sent;
143 }
144
iscsi_next_hdr(struct iscsi_task * task)145 static inline void* iscsi_next_hdr(struct iscsi_task *task)
146 {
147 return (void*)task->hdr + task->hdr_len;
148 }
149
iscsi_task_is_completed(struct iscsi_task * task)150 static inline bool iscsi_task_is_completed(struct iscsi_task *task)
151 {
152 return task->state == ISCSI_TASK_COMPLETED ||
153 task->state == ISCSI_TASK_ABRT_TMF ||
154 task->state == ISCSI_TASK_ABRT_SESS_RECOV;
155 }
156
157 /* Connection's states */
158 enum {
159 ISCSI_CONN_INITIAL_STAGE,
160 ISCSI_CONN_STARTED,
161 ISCSI_CONN_STOPPED,
162 ISCSI_CONN_CLEANUP_WAIT,
163 };
164
165 struct 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 /* items must be added/deleted under frwd lock */
200 struct list_head mgmtqueue; /* mgmt (control) xmit queue */
201 struct list_head cmdqueue; /* data-path cmd queue */
202 struct list_head requeue; /* tasks needing another run */
203 struct work_struct xmitwork; /* per-conn. xmit workqueue */
204 /* recv */
205 struct work_struct recvwork;
206 unsigned long flags; /* ISCSI_CONN_FLAGs */
207
208 /* negotiated params */
209 unsigned max_recv_dlength; /* initiator_max_recv_dsl*/
210 unsigned max_xmit_dlength; /* target_max_recv_dsl */
211 int hdrdgst_en;
212 int datadgst_en;
213 int ifmarker_en;
214 int ofmarker_en;
215 /* values userspace uses to id a conn */
216 int persistent_port;
217 char *persistent_address;
218
219 unsigned max_segment_size;
220 unsigned tcp_xmit_wsf;
221 unsigned tcp_recv_wsf;
222 uint16_t keepalive_tmo;
223 uint16_t local_port;
224 uint8_t tcp_timestamp_stat;
225 uint8_t tcp_nagle_disable;
226 uint8_t tcp_wsf_disable;
227 uint8_t tcp_timer_scale;
228 uint8_t tcp_timestamp_en;
229 uint8_t fragment_disable;
230 uint8_t ipv4_tos;
231 uint8_t ipv6_traffic_class;
232 uint8_t ipv6_flow_label;
233 uint8_t is_fw_assigned_ipv6;
234 char *local_ipaddr;
235
236 /* MIB-statistics */
237 uint64_t txdata_octets;
238 uint64_t rxdata_octets;
239 uint32_t scsicmd_pdus_cnt;
240 uint32_t dataout_pdus_cnt;
241 uint32_t scsirsp_pdus_cnt;
242 uint32_t datain_pdus_cnt;
243 uint32_t r2t_pdus_cnt;
244 uint32_t tmfcmd_pdus_cnt;
245 int32_t tmfrsp_pdus_cnt;
246
247 /* custom statistics */
248 uint32_t eh_abort_cnt;
249 uint32_t fmr_unalign_cnt;
250 };
251
252 struct iscsi_pool {
253 struct kfifo queue; /* FIFO Queue */
254 void **pool; /* Pool of elements */
255 int max; /* Max number of elements */
256 };
257
258 /* Session's states */
259 enum {
260 ISCSI_STATE_FREE = 1,
261 ISCSI_STATE_LOGGED_IN,
262 ISCSI_STATE_FAILED,
263 ISCSI_STATE_TERMINATE,
264 ISCSI_STATE_IN_RECOVERY,
265 ISCSI_STATE_RECOVERY_FAILED,
266 ISCSI_STATE_LOGGING_OUT,
267 };
268
269 struct iscsi_session {
270 struct iscsi_cls_session *cls_session;
271 /*
272 * Syncs up the scsi eh thread with the iscsi eh thread when sending
273 * task management functions. This must be taken before the session
274 * and recv lock.
275 */
276 struct mutex eh_mutex;
277 /* abort */
278 wait_queue_head_t ehwait; /* used in eh_abort() */
279 struct iscsi_tm tmhdr;
280 struct timer_list tmf_timer;
281 int tmf_state; /* see TMF_INITIAL, etc.*/
282 struct iscsi_task *running_aborted_task;
283
284 /* iSCSI session-wide sequencing */
285 uint32_t cmdsn;
286 uint32_t exp_cmdsn;
287 uint32_t max_cmdsn;
288
289 /* This tracks the reqs queued into the initiator */
290 uint32_t queued_cmdsn;
291
292 /* configuration */
293 int abort_timeout;
294 int lu_reset_timeout;
295 int tgt_reset_timeout;
296 int initial_r2t_en;
297 unsigned short max_r2t;
298 int imm_data_en;
299 unsigned first_burst;
300 unsigned max_burst;
301 int time2wait;
302 int time2retain;
303 int pdu_inorder_en;
304 int dataseq_inorder_en;
305 int erl;
306 int fast_abort;
307 int tpgt;
308 char *username;
309 char *username_in;
310 char *password;
311 char *password_in;
312 char *targetname;
313 char *targetalias;
314 char *ifacename;
315 char *initiatorname;
316 char *boot_root;
317 char *boot_nic;
318 char *boot_target;
319 char *portal_type;
320 char *discovery_parent_type;
321 uint16_t discovery_parent_idx;
322 uint16_t def_taskmgmt_tmo;
323 uint16_t tsid;
324 uint8_t auto_snd_tgt_disable;
325 uint8_t discovery_sess;
326 uint8_t chap_auth_en;
327 uint8_t discovery_logout_en;
328 uint8_t bidi_chap_en;
329 uint8_t discovery_auth_optional;
330 uint8_t isid[ISID_SIZE];
331
332 /* control data */
333 struct iscsi_transport *tt;
334 struct Scsi_Host *host;
335 struct iscsi_conn *leadconn; /* leading connection */
336 /* Between the forward and the backward locks exists a strict locking
337 * hierarchy. The mutual exclusion zone protected by the forward lock
338 * can enclose the mutual exclusion zone protected by the backward lock
339 * but not vice versa.
340 */
341 spinlock_t frwd_lock; /* protects session state, *
342 * cmdsn, queued_cmdsn *
343 * session resources: *
344 * - cmdpool kfifo_out , *
345 * - mgmtpool, queues */
346 spinlock_t back_lock; /* protects cmdsn_exp *
347 * cmdsn_max, *
348 * cmdpool kfifo_in */
349 int state; /* session state */
350 int age; /* counts session re-opens */
351
352 int scsi_cmds_max; /* max scsi commands */
353 int cmds_max; /* size of cmds array */
354 struct iscsi_task **cmds; /* Original Cmds arr */
355 struct iscsi_pool cmdpool; /* PDU's pool */
356 void *dd_data; /* LLD private data */
357 };
358
359 enum {
360 ISCSI_HOST_SETUP,
361 ISCSI_HOST_REMOVED,
362 };
363
364 struct iscsi_host {
365 char *initiatorname;
366 /* hw address or netdev iscsi connection is bound to */
367 char *hwaddress;
368 char *netdev;
369
370 wait_queue_head_t session_removal_wq;
371 /* protects sessions and state */
372 spinlock_t lock;
373 int num_sessions;
374 int state;
375
376 struct workqueue_struct *workq;
377 char workq_name[20];
378 };
379
380 /*
381 * scsi host template
382 */
383 extern int iscsi_eh_abort(struct scsi_cmnd *sc);
384 extern int iscsi_eh_recover_target(struct scsi_cmnd *sc);
385 extern int iscsi_eh_session_reset(struct scsi_cmnd *sc);
386 extern int iscsi_eh_device_reset(struct scsi_cmnd *sc);
387 extern int iscsi_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *sc);
388 extern enum blk_eh_timer_return iscsi_eh_cmd_timed_out(struct scsi_cmnd *sc);
389
390 /*
391 * iSCSI host helpers.
392 */
393 #define iscsi_host_priv(_shost) \
394 (shost_priv(_shost) + sizeof(struct iscsi_host))
395
396 extern int iscsi_host_set_param(struct Scsi_Host *shost,
397 enum iscsi_host_param param, char *buf,
398 int buflen);
399 extern int iscsi_host_get_param(struct Scsi_Host *shost,
400 enum iscsi_host_param param, char *buf);
401 extern int iscsi_host_add(struct Scsi_Host *shost, struct device *pdev);
402 extern struct Scsi_Host *iscsi_host_alloc(struct scsi_host_template *sht,
403 int dd_data_size,
404 bool xmit_can_sleep);
405 extern void iscsi_host_remove(struct Scsi_Host *shost, bool is_shutdown);
406 extern void iscsi_host_free(struct Scsi_Host *shost);
407 extern int iscsi_target_alloc(struct scsi_target *starget);
408 extern int iscsi_host_get_max_scsi_cmds(struct Scsi_Host *shost,
409 uint16_t requested_cmds_max);
410
411 /*
412 * session management
413 */
414 extern struct iscsi_cls_session *
415 iscsi_session_setup(struct iscsi_transport *, struct Scsi_Host *shost,
416 uint16_t, int, int, uint32_t, unsigned int);
417 void iscsi_session_remove(struct iscsi_cls_session *cls_session);
418 void iscsi_session_free(struct iscsi_cls_session *cls_session);
419 extern void iscsi_session_teardown(struct iscsi_cls_session *);
420 extern void iscsi_session_recovery_timedout(struct iscsi_cls_session *);
421 extern int iscsi_set_param(struct iscsi_cls_conn *cls_conn,
422 enum iscsi_param param, char *buf, int buflen);
423 extern int iscsi_session_get_param(struct iscsi_cls_session *cls_session,
424 enum iscsi_param param, char *buf);
425
426 #define iscsi_session_printk(prefix, _sess, fmt, a...) \
427 iscsi_cls_session_printk(prefix, _sess->cls_session, fmt, ##a)
428
429 /*
430 * connection management
431 */
432 extern struct iscsi_cls_conn *iscsi_conn_setup(struct iscsi_cls_session *,
433 int, uint32_t);
434 extern void iscsi_conn_teardown(struct iscsi_cls_conn *);
435 extern int iscsi_conn_start(struct iscsi_cls_conn *);
436 extern void iscsi_conn_stop(struct iscsi_cls_conn *, int);
437 extern int iscsi_conn_bind(struct iscsi_cls_session *, struct iscsi_cls_conn *,
438 int);
439 extern void iscsi_conn_unbind(struct iscsi_cls_conn *cls_conn, bool is_active);
440 extern void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err);
441 extern void iscsi_session_failure(struct iscsi_session *session,
442 enum iscsi_err err);
443 extern int iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
444 enum iscsi_param param, char *buf);
445 extern int iscsi_conn_get_addr_param(struct sockaddr_storage *addr,
446 enum iscsi_param param, char *buf);
447 extern void iscsi_suspend_tx(struct iscsi_conn *conn);
448 extern void iscsi_suspend_rx(struct iscsi_conn *conn);
449 extern void iscsi_suspend_queue(struct iscsi_conn *conn);
450 extern void iscsi_conn_queue_xmit(struct iscsi_conn *conn);
451 extern void iscsi_conn_queue_recv(struct iscsi_conn *conn);
452
453 #define iscsi_conn_printk(prefix, _c, fmt, a...) \
454 iscsi_cls_conn_printk(prefix, ((struct iscsi_conn *)_c)->cls_conn, \
455 fmt, ##a)
456
457 /*
458 * pdu and task processing
459 */
460 extern void iscsi_update_cmdsn(struct iscsi_session *, struct iscsi_nopin *);
461 extern void iscsi_prep_data_out_pdu(struct iscsi_task *task,
462 struct iscsi_r2t_info *r2t,
463 struct iscsi_data *hdr);
464 extern int iscsi_conn_send_pdu(struct iscsi_cls_conn *, struct iscsi_hdr *,
465 char *, uint32_t);
466 extern int iscsi_complete_pdu(struct iscsi_conn *, struct iscsi_hdr *,
467 char *, int);
468 extern int __iscsi_complete_pdu(struct iscsi_conn *, struct iscsi_hdr *,
469 char *, int);
470 extern int iscsi_verify_itt(struct iscsi_conn *, itt_t);
471 extern struct iscsi_task *iscsi_itt_to_ctask(struct iscsi_conn *, itt_t);
472 extern struct iscsi_task *iscsi_itt_to_task(struct iscsi_conn *, itt_t);
473 extern void iscsi_requeue_task(struct iscsi_task *task);
474 extern void iscsi_put_task(struct iscsi_task *task);
475 extern void __iscsi_put_task(struct iscsi_task *task);
476 extern void __iscsi_get_task(struct iscsi_task *task);
477 extern void iscsi_complete_scsi_task(struct iscsi_task *task,
478 uint32_t exp_cmdsn, uint32_t max_cmdsn);
479
480 /*
481 * generic helpers
482 */
483 extern void iscsi_pool_free(struct iscsi_pool *);
484 extern int iscsi_pool_init(struct iscsi_pool *, int, void ***, int);
485 extern int iscsi_switch_str_param(char **, char *);
486
487 /*
488 * inline functions to deal with padding.
489 */
490 static inline unsigned int
iscsi_padded(unsigned int len)491 iscsi_padded(unsigned int len)
492 {
493 return (len + ISCSI_PAD_LEN - 1) & ~(ISCSI_PAD_LEN - 1);
494 }
495
496 static inline unsigned int
iscsi_padding(unsigned int len)497 iscsi_padding(unsigned int len)
498 {
499 len &= (ISCSI_PAD_LEN - 1);
500 if (len)
501 len = ISCSI_PAD_LEN - len;
502 return len;
503 }
504
505 #endif
506