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_cmnd.h>
23 #include <scsi/scsi_transport_iscsi.h>
24
25 struct scsi_transport_template;
26 struct scsi_host_template;
27 struct scsi_device;
28 struct Scsi_Host;
29 struct scsi_target;
30 struct scsi_cmnd;
31 struct socket;
32 struct iscsi_transport;
33 struct iscsi_cls_session;
34 struct iscsi_cls_conn;
35 struct iscsi_session;
36 struct iscsi_nopin;
37 struct device;
38
39 #define ISCSI_DEF_XMIT_CMDS_MAX 128 /* must be power of 2 */
40 #define ISCSI_MGMT_CMDS_MAX 15
41
42 #define ISCSI_DEF_CMD_PER_LUN 32
43
44 /* Task Mgmt states */
45 enum {
46 TMF_INITIAL,
47 TMF_QUEUED,
48 TMF_SUCCESS,
49 TMF_FAILED,
50 TMF_TIMEDOUT,
51 TMF_NOT_FOUND,
52 };
53
54 #define ISID_SIZE 6
55
56 /* Connection flags */
57 #define ISCSI_CONN_FLAG_SUSPEND_TX 0
58 #define ISCSI_CONN_FLAG_SUSPEND_RX 1
59 #define ISCSI_CONN_FLAG_BOUND 2
60
61 #define ISCSI_ITT_MASK 0x1fff
62 #define ISCSI_TOTAL_CMDS_MAX 4096
63 /* this must be a power of two greater than ISCSI_MGMT_CMDS_MAX */
64 #define ISCSI_TOTAL_CMDS_MIN 16
65 #define ISCSI_AGE_SHIFT 28
66 #define ISCSI_AGE_MASK 0xf
67
68 #define ISCSI_ADDRESS_BUF_LEN 64
69
70 enum {
71 /* this is the maximum possible storage for AHSs */
72 ISCSI_MAX_AHS_SIZE = sizeof(struct iscsi_ecdb_ahdr) +
73 sizeof(struct iscsi_rlength_ahdr),
74 ISCSI_DIGEST_SIZE = sizeof(__u32),
75 };
76
77
78 enum {
79 ISCSI_TASK_FREE,
80 ISCSI_TASK_COMPLETED,
81 ISCSI_TASK_PENDING,
82 ISCSI_TASK_RUNNING,
83 ISCSI_TASK_ABRT_TMF, /* aborted due to TMF */
84 ISCSI_TASK_ABRT_SESS_RECOV, /* aborted due to session recovery */
85 ISCSI_TASK_REQUEUE_SCSIQ, /* qcmd requeueing to scsi-ml */
86 };
87
88 struct iscsi_r2t_info {
89 __be32 ttt; /* copied from R2T */
90 __be32 exp_statsn; /* copied from R2T */
91 uint32_t data_length; /* copied from R2T */
92 uint32_t data_offset; /* copied from R2T */
93 int data_count; /* DATA-Out payload progress */
94 int datasn;
95 /* LLDs should set/update these values */
96 int sent; /* R2T sequence progress */
97 };
98
99 struct iscsi_task {
100 /*
101 * Because LLDs allocate their hdr differently, this is a pointer
102 * and length to that storage. It must be setup at session
103 * creation time.
104 */
105 struct iscsi_hdr *hdr;
106 unsigned short hdr_max;
107 unsigned short hdr_len; /* accumulated size of hdr used */
108 /* copied values in case we need to send tmfs */
109 itt_t hdr_itt;
110 __be32 cmdsn;
111 struct scsi_lun lun;
112
113 int itt; /* this ITT */
114
115 unsigned imm_count; /* imm-data (bytes) */
116 /* offset in unsolicited stream (bytes); */
117 struct iscsi_r2t_info unsol_r2t;
118 char *data; /* mgmt payload */
119 unsigned data_count;
120 struct scsi_cmnd *sc; /* associated SCSI cmd*/
121 struct iscsi_conn *conn; /* used connection */
122
123 /* data processing tracking */
124 unsigned long last_xfer;
125 unsigned long last_timeout;
126 bool have_checked_conn;
127
128 /* T10 protection information */
129 bool protected;
130
131 /* state set/tested under session->lock */
132 int state;
133 refcount_t refcount;
134 struct list_head running; /* running cmd list */
135 void *dd_data; /* driver/transport data */
136 };
137
138 /* invalid scsi_task pointer */
139 #define INVALID_SCSI_TASK (struct iscsi_task *)-1l
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
iscsi_task_is_completed(struct iscsi_task * task)151 static inline bool iscsi_task_is_completed(struct iscsi_task *task)
152 {
153 return task->state == ISCSI_TASK_COMPLETED ||
154 task->state == ISCSI_TASK_ABRT_TMF ||
155 task->state == ISCSI_TASK_ABRT_SESS_RECOV;
156 }
157
158 /* Private data associated with struct scsi_cmnd. */
159 struct iscsi_cmd {
160 struct iscsi_task *task;
161 int age;
162 };
163
iscsi_cmd(struct scsi_cmnd * cmd)164 static inline struct iscsi_cmd *iscsi_cmd(struct scsi_cmnd *cmd)
165 {
166 return scsi_cmd_priv(cmd);
167 }
168
169 /* Connection's states */
170 enum {
171 ISCSI_CONN_INITIAL_STAGE,
172 ISCSI_CONN_STARTED,
173 ISCSI_CONN_STOPPED,
174 ISCSI_CONN_CLEANUP_WAIT,
175 };
176
177 struct iscsi_conn {
178 struct iscsi_cls_conn *cls_conn; /* ptr to class connection */
179 void *dd_data; /* iscsi_transport data */
180 struct iscsi_session *session; /* parent session */
181 /*
182 * conn_stop() flag: stop to recover, stop to terminate
183 */
184 int stop_stage;
185 struct timer_list transport_timer;
186 unsigned long last_recv;
187 unsigned long last_ping;
188 int ping_timeout;
189 int recv_timeout;
190 struct iscsi_task *ping_task;
191
192 /* iSCSI connection-wide sequencing */
193 uint32_t exp_statsn;
194 uint32_t statsn;
195
196 /* control data */
197 int id; /* CID */
198 int c_stage; /* connection state */
199 /*
200 * Preallocated buffer for pdus that have data but do not
201 * originate from scsi-ml. We never have two pdus using the
202 * buffer at the same time. It is only allocated to
203 * the default max recv size because the pdus we support
204 * should always fit in this buffer
205 */
206 char *data;
207 struct iscsi_task *login_task; /* mtask used for login/text */
208 struct iscsi_task *task; /* xmit task in progress */
209
210 /* xmit */
211 /* items must be added/deleted under frwd lock */
212 struct list_head mgmtqueue; /* mgmt (control) xmit queue */
213 struct list_head cmdqueue; /* data-path cmd queue */
214 struct list_head requeue; /* tasks needing another run */
215 struct work_struct xmitwork; /* per-conn. xmit workqueue */
216 unsigned long flags; /* ISCSI_CONN_FLAGs */
217
218 /* negotiated params */
219 unsigned max_recv_dlength; /* initiator_max_recv_dsl*/
220 unsigned max_xmit_dlength; /* target_max_recv_dsl */
221 int hdrdgst_en;
222 int datadgst_en;
223 int ifmarker_en;
224 int ofmarker_en;
225 /* values userspace uses to id a conn */
226 int persistent_port;
227 char *persistent_address;
228
229 unsigned max_segment_size;
230 unsigned tcp_xmit_wsf;
231 unsigned tcp_recv_wsf;
232 uint16_t keepalive_tmo;
233 uint16_t local_port;
234 uint8_t tcp_timestamp_stat;
235 uint8_t tcp_nagle_disable;
236 uint8_t tcp_wsf_disable;
237 uint8_t tcp_timer_scale;
238 uint8_t tcp_timestamp_en;
239 uint8_t fragment_disable;
240 uint8_t ipv4_tos;
241 uint8_t ipv6_traffic_class;
242 uint8_t ipv6_flow_label;
243 uint8_t is_fw_assigned_ipv6;
244 char *local_ipaddr;
245
246 /* MIB-statistics */
247 uint64_t txdata_octets;
248 uint64_t rxdata_octets;
249 uint32_t scsicmd_pdus_cnt;
250 uint32_t dataout_pdus_cnt;
251 uint32_t scsirsp_pdus_cnt;
252 uint32_t datain_pdus_cnt;
253 uint32_t r2t_pdus_cnt;
254 uint32_t tmfcmd_pdus_cnt;
255 int32_t tmfrsp_pdus_cnt;
256
257 /* custom statistics */
258 uint32_t eh_abort_cnt;
259 uint32_t fmr_unalign_cnt;
260 };
261
262 struct iscsi_pool {
263 struct kfifo queue; /* FIFO Queue */
264 void **pool; /* Pool of elements */
265 int max; /* Max number of elements */
266 };
267
268 /* Session's states */
269 enum {
270 ISCSI_STATE_FREE = 1,
271 ISCSI_STATE_LOGGED_IN,
272 ISCSI_STATE_FAILED,
273 ISCSI_STATE_TERMINATE,
274 ISCSI_STATE_IN_RECOVERY,
275 ISCSI_STATE_RECOVERY_FAILED,
276 ISCSI_STATE_LOGGING_OUT,
277 };
278
279 struct iscsi_session {
280 struct iscsi_cls_session *cls_session;
281 /*
282 * Syncs up the scsi eh thread with the iscsi eh thread when sending
283 * task management functions. This must be taken before the session
284 * and recv lock.
285 */
286 struct mutex eh_mutex;
287 /* abort */
288 wait_queue_head_t ehwait; /* used in eh_abort() */
289 struct iscsi_tm tmhdr;
290 struct timer_list tmf_timer;
291 int tmf_state; /* see TMF_INITIAL, etc.*/
292 struct iscsi_task *running_aborted_task;
293
294 /* iSCSI session-wide sequencing */
295 uint32_t cmdsn;
296 uint32_t exp_cmdsn;
297 uint32_t max_cmdsn;
298
299 /* This tracks the reqs queued into the initiator */
300 uint32_t queued_cmdsn;
301
302 /* configuration */
303 int abort_timeout;
304 int lu_reset_timeout;
305 int tgt_reset_timeout;
306 int initial_r2t_en;
307 unsigned short max_r2t;
308 int imm_data_en;
309 unsigned first_burst;
310 unsigned max_burst;
311 int time2wait;
312 int time2retain;
313 int pdu_inorder_en;
314 int dataseq_inorder_en;
315 int erl;
316 int fast_abort;
317 int tpgt;
318 char *username;
319 char *username_in;
320 char *password;
321 char *password_in;
322 char *targetname;
323 char *targetalias;
324 char *ifacename;
325 char *initiatorname;
326 char *boot_root;
327 char *boot_nic;
328 char *boot_target;
329 char *portal_type;
330 char *discovery_parent_type;
331 uint16_t discovery_parent_idx;
332 uint16_t def_taskmgmt_tmo;
333 uint16_t tsid;
334 uint8_t auto_snd_tgt_disable;
335 uint8_t discovery_sess;
336 uint8_t chap_auth_en;
337 uint8_t discovery_logout_en;
338 uint8_t bidi_chap_en;
339 uint8_t discovery_auth_optional;
340 uint8_t isid[ISID_SIZE];
341
342 /* control data */
343 struct iscsi_transport *tt;
344 struct Scsi_Host *host;
345 struct iscsi_conn *leadconn; /* leading connection */
346 /* Between the forward and the backward locks exists a strict locking
347 * hierarchy. The mutual exclusion zone protected by the forward lock
348 * can enclose the mutual exclusion zone protected by the backward lock
349 * but not vice versa.
350 */
351 spinlock_t frwd_lock; /* protects session state, *
352 * cmdsn, queued_cmdsn *
353 * session resources: *
354 * - cmdpool kfifo_out , *
355 * - mgmtpool, queues */
356 spinlock_t back_lock; /* protects cmdsn_exp *
357 * cmdsn_max, *
358 * cmdpool kfifo_in */
359 int state; /* session state */
360 int age; /* counts session re-opens */
361
362 int scsi_cmds_max; /* max scsi commands */
363 int cmds_max; /* size of cmds array */
364 struct iscsi_task **cmds; /* Original Cmds arr */
365 struct iscsi_pool cmdpool; /* PDU's pool */
366 void *dd_data; /* LLD private data */
367 };
368
369 enum {
370 ISCSI_HOST_SETUP,
371 ISCSI_HOST_REMOVED,
372 };
373
374 struct iscsi_host {
375 char *initiatorname;
376 /* hw address or netdev iscsi connection is bound to */
377 char *hwaddress;
378 char *netdev;
379
380 wait_queue_head_t session_removal_wq;
381 /* protects sessions and state */
382 spinlock_t lock;
383 int num_sessions;
384 int state;
385
386 struct workqueue_struct *workq;
387 };
388
389 /*
390 * scsi host template
391 */
392 extern int iscsi_eh_abort(struct scsi_cmnd *sc);
393 extern int iscsi_eh_recover_target(struct scsi_cmnd *sc);
394 extern int iscsi_eh_session_reset(struct scsi_cmnd *sc);
395 extern int iscsi_eh_device_reset(struct scsi_cmnd *sc);
396 extern int iscsi_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *sc);
397 extern enum blk_eh_timer_return iscsi_eh_cmd_timed_out(struct scsi_cmnd *sc);
398
399 /*
400 * iSCSI host helpers.
401 */
402 #define iscsi_host_priv(_shost) \
403 (shost_priv(_shost) + sizeof(struct iscsi_host))
404
405 extern int iscsi_host_set_param(struct Scsi_Host *shost,
406 enum iscsi_host_param param, char *buf,
407 int buflen);
408 extern int iscsi_host_get_param(struct Scsi_Host *shost,
409 enum iscsi_host_param param, char *buf);
410 extern int iscsi_host_add(struct Scsi_Host *shost, struct device *pdev);
411 extern struct Scsi_Host *iscsi_host_alloc(struct scsi_host_template *sht,
412 int dd_data_size,
413 bool xmit_can_sleep);
414 extern void iscsi_host_remove(struct Scsi_Host *shost, bool is_shutdown);
415 extern void iscsi_host_free(struct Scsi_Host *shost);
416 extern int iscsi_target_alloc(struct scsi_target *starget);
417 extern int iscsi_host_get_max_scsi_cmds(struct Scsi_Host *shost,
418 uint16_t requested_cmds_max);
419
420 /*
421 * session management
422 */
423 extern struct iscsi_cls_session *
424 iscsi_session_setup(struct iscsi_transport *, struct Scsi_Host *shost,
425 uint16_t, int, int, uint32_t, unsigned int);
426 extern void iscsi_session_teardown(struct iscsi_cls_session *);
427 extern void iscsi_session_recovery_timedout(struct iscsi_cls_session *);
428 extern int iscsi_set_param(struct iscsi_cls_conn *cls_conn,
429 enum iscsi_param param, char *buf, int buflen);
430 extern int iscsi_session_get_param(struct iscsi_cls_session *cls_session,
431 enum iscsi_param param, char *buf);
432
433 #define iscsi_session_printk(prefix, _sess, fmt, a...) \
434 iscsi_cls_session_printk(prefix, _sess->cls_session, fmt, ##a)
435
436 /*
437 * connection management
438 */
439 extern struct iscsi_cls_conn *iscsi_conn_setup(struct iscsi_cls_session *,
440 int, uint32_t);
441 extern void iscsi_conn_teardown(struct iscsi_cls_conn *);
442 extern int iscsi_conn_start(struct iscsi_cls_conn *);
443 extern void iscsi_conn_stop(struct iscsi_cls_conn *, int);
444 extern int iscsi_conn_bind(struct iscsi_cls_session *, struct iscsi_cls_conn *,
445 int);
446 extern void iscsi_conn_unbind(struct iscsi_cls_conn *cls_conn, bool is_active);
447 extern void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err);
448 extern void iscsi_session_failure(struct iscsi_session *session,
449 enum iscsi_err err);
450 extern int iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
451 enum iscsi_param param, char *buf);
452 extern int iscsi_conn_get_addr_param(struct sockaddr_storage *addr,
453 enum iscsi_param param, char *buf);
454 extern void iscsi_suspend_tx(struct iscsi_conn *conn);
455 extern void iscsi_suspend_queue(struct iscsi_conn *conn);
456 extern void iscsi_conn_queue_work(struct iscsi_conn *conn);
457
458 #define iscsi_conn_printk(prefix, _c, fmt, a...) \
459 iscsi_cls_conn_printk(prefix, ((struct iscsi_conn *)_c)->cls_conn, \
460 fmt, ##a)
461
462 /*
463 * pdu and task processing
464 */
465 extern void iscsi_update_cmdsn(struct iscsi_session *, struct iscsi_nopin *);
466 extern void iscsi_prep_data_out_pdu(struct iscsi_task *task,
467 struct iscsi_r2t_info *r2t,
468 struct iscsi_data *hdr);
469 extern int iscsi_conn_send_pdu(struct iscsi_cls_conn *, struct iscsi_hdr *,
470 char *, uint32_t);
471 extern int iscsi_complete_pdu(struct iscsi_conn *, struct iscsi_hdr *,
472 char *, int);
473 extern int __iscsi_complete_pdu(struct iscsi_conn *, struct iscsi_hdr *,
474 char *, int);
475 extern int iscsi_verify_itt(struct iscsi_conn *, itt_t);
476 extern struct iscsi_task *iscsi_itt_to_ctask(struct iscsi_conn *, itt_t);
477 extern struct iscsi_task *iscsi_itt_to_task(struct iscsi_conn *, itt_t);
478 extern void iscsi_requeue_task(struct iscsi_task *task);
479 extern void iscsi_put_task(struct iscsi_task *task);
480 extern void __iscsi_put_task(struct iscsi_task *task);
481 extern void __iscsi_get_task(struct iscsi_task *task);
482 extern void iscsi_complete_scsi_task(struct iscsi_task *task,
483 uint32_t exp_cmdsn, uint32_t max_cmdsn);
484
485 /*
486 * generic helpers
487 */
488 extern void iscsi_pool_free(struct iscsi_pool *);
489 extern int iscsi_pool_init(struct iscsi_pool *, int, void ***, int);
490 extern int iscsi_switch_str_param(char **, char *);
491
492 /*
493 * inline functions to deal with padding.
494 */
495 static inline unsigned int
iscsi_padded(unsigned int len)496 iscsi_padded(unsigned int len)
497 {
498 return (len + ISCSI_PAD_LEN - 1) & ~(ISCSI_PAD_LEN - 1);
499 }
500
501 static inline unsigned int
iscsi_padding(unsigned int len)502 iscsi_padding(unsigned int len)
503 {
504 len &= (ISCSI_PAD_LEN - 1);
505 if (len)
506 len = ISCSI_PAD_LEN - len;
507 return len;
508 }
509
510 #endif
511