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
148 /* Connection's states */
149 enum {
150 ISCSI_CONN_INITIAL_STAGE,
151 ISCSI_CONN_STARTED,
152 ISCSI_CONN_STOPPED,
153 ISCSI_CONN_CLEANUP_WAIT,
154 };
155
156 struct iscsi_conn {
157 struct iscsi_cls_conn *cls_conn; /* ptr to class connection */
158 void *dd_data; /* iscsi_transport data */
159 struct iscsi_session *session; /* parent session */
160 /*
161 * conn_stop() flag: stop to recover, stop to terminate
162 */
163 int stop_stage;
164 struct timer_list transport_timer;
165 unsigned long last_recv;
166 unsigned long last_ping;
167 int ping_timeout;
168 int recv_timeout;
169 struct iscsi_task *ping_task;
170
171 /* iSCSI connection-wide sequencing */
172 uint32_t exp_statsn;
173 uint32_t statsn;
174
175 /* control data */
176 int id; /* CID */
177 int c_stage; /* connection state */
178 /*
179 * Preallocated buffer for pdus that have data but do not
180 * originate from scsi-ml. We never have two pdus using the
181 * buffer at the same time. It is only allocated to
182 * the default max recv size because the pdus we support
183 * should always fit in this buffer
184 */
185 char *data;
186 struct iscsi_task *login_task; /* mtask used for login/text */
187 struct iscsi_task *task; /* xmit task in progress */
188
189 /* xmit */
190 /* items must be added/deleted under frwd lock */
191 struct list_head mgmtqueue; /* mgmt (control) xmit queue */
192 struct list_head cmdqueue; /* data-path cmd queue */
193 struct list_head requeue; /* tasks needing another run */
194 struct work_struct xmitwork; /* per-conn. xmit workqueue */
195 unsigned long suspend_tx; /* suspend Tx */
196 unsigned long suspend_rx; /* suspend Rx */
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
209 unsigned max_segment_size;
210 unsigned tcp_xmit_wsf;
211 unsigned tcp_recv_wsf;
212 uint16_t keepalive_tmo;
213 uint16_t local_port;
214 uint8_t tcp_timestamp_stat;
215 uint8_t tcp_nagle_disable;
216 uint8_t tcp_wsf_disable;
217 uint8_t tcp_timer_scale;
218 uint8_t tcp_timestamp_en;
219 uint8_t fragment_disable;
220 uint8_t ipv4_tos;
221 uint8_t ipv6_traffic_class;
222 uint8_t ipv6_flow_label;
223 uint8_t is_fw_assigned_ipv6;
224 char *local_ipaddr;
225
226 /* MIB-statistics */
227 uint64_t txdata_octets;
228 uint64_t rxdata_octets;
229 uint32_t scsicmd_pdus_cnt;
230 uint32_t dataout_pdus_cnt;
231 uint32_t scsirsp_pdus_cnt;
232 uint32_t datain_pdus_cnt;
233 uint32_t r2t_pdus_cnt;
234 uint32_t tmfcmd_pdus_cnt;
235 int32_t tmfrsp_pdus_cnt;
236
237 /* custom statistics */
238 uint32_t eh_abort_cnt;
239 uint32_t fmr_unalign_cnt;
240 };
241
242 struct iscsi_pool {
243 struct kfifo queue; /* FIFO Queue */
244 void **pool; /* Pool of elements */
245 int max; /* Max number of elements */
246 };
247
248 /* Session's states */
249 enum {
250 ISCSI_STATE_FREE = 1,
251 ISCSI_STATE_LOGGED_IN,
252 ISCSI_STATE_FAILED,
253 ISCSI_STATE_TERMINATE,
254 ISCSI_STATE_IN_RECOVERY,
255 ISCSI_STATE_RECOVERY_FAILED,
256 ISCSI_STATE_LOGGING_OUT,
257 };
258
259 struct iscsi_session {
260 struct iscsi_cls_session *cls_session;
261 /*
262 * Syncs up the scsi eh thread with the iscsi eh thread when sending
263 * task management functions. This must be taken before the session
264 * and recv lock.
265 */
266 struct mutex eh_mutex;
267 /* abort */
268 wait_queue_head_t ehwait; /* used in eh_abort() */
269 struct iscsi_tm tmhdr;
270 struct timer_list tmf_timer;
271 int tmf_state; /* see TMF_INITIAL, etc.*/
272
273 /* iSCSI session-wide sequencing */
274 uint32_t cmdsn;
275 uint32_t exp_cmdsn;
276 uint32_t max_cmdsn;
277
278 /* This tracks the reqs queued into the initiator */
279 uint32_t queued_cmdsn;
280
281 /* configuration */
282 int abort_timeout;
283 int lu_reset_timeout;
284 int tgt_reset_timeout;
285 int initial_r2t_en;
286 unsigned short max_r2t;
287 int imm_data_en;
288 unsigned first_burst;
289 unsigned max_burst;
290 int time2wait;
291 int time2retain;
292 int pdu_inorder_en;
293 int dataseq_inorder_en;
294 int erl;
295 int fast_abort;
296 int tpgt;
297 char *username;
298 char *username_in;
299 char *password;
300 char *password_in;
301 char *targetname;
302 char *targetalias;
303 char *ifacename;
304 char *initiatorname;
305 char *boot_root;
306 char *boot_nic;
307 char *boot_target;
308 char *portal_type;
309 char *discovery_parent_type;
310 uint16_t discovery_parent_idx;
311 uint16_t def_taskmgmt_tmo;
312 uint16_t tsid;
313 uint8_t auto_snd_tgt_disable;
314 uint8_t discovery_sess;
315 uint8_t chap_auth_en;
316 uint8_t discovery_logout_en;
317 uint8_t bidi_chap_en;
318 uint8_t discovery_auth_optional;
319 uint8_t isid[ISID_SIZE];
320
321 /* control data */
322 struct iscsi_transport *tt;
323 struct Scsi_Host *host;
324 struct iscsi_conn *leadconn; /* leading connection */
325 /* Between the forward and the backward locks exists a strict locking
326 * hierarchy. The mutual exclusion zone protected by the forward lock
327 * can enclose the mutual exclusion zone protected by the backward lock
328 * but not vice versa.
329 */
330 spinlock_t frwd_lock; /* protects session state, *
331 * cmdsn, queued_cmdsn *
332 * session resources: *
333 * - cmdpool kfifo_out , *
334 * - mgmtpool, queues */
335 spinlock_t back_lock; /* protects cmdsn_exp *
336 * cmdsn_max, *
337 * cmdpool kfifo_in */
338 int state; /* session state */
339 int age; /* counts session re-opens */
340
341 int scsi_cmds_max; /* max scsi commands */
342 int cmds_max; /* size of cmds array */
343 struct iscsi_task **cmds; /* Original Cmds arr */
344 struct iscsi_pool cmdpool; /* PDU's pool */
345 void *dd_data; /* LLD private data */
346 };
347
348 enum {
349 ISCSI_HOST_SETUP,
350 ISCSI_HOST_REMOVED,
351 };
352
353 struct iscsi_host {
354 char *initiatorname;
355 /* hw address or netdev iscsi connection is bound to */
356 char *hwaddress;
357 char *netdev;
358
359 wait_queue_head_t session_removal_wq;
360 /* protects sessions and state */
361 spinlock_t lock;
362 int num_sessions;
363 int state;
364
365 struct workqueue_struct *workq;
366 char workq_name[20];
367 };
368
369 /*
370 * scsi host template
371 */
372 extern int iscsi_eh_abort(struct scsi_cmnd *sc);
373 extern int iscsi_eh_recover_target(struct scsi_cmnd *sc);
374 extern int iscsi_eh_session_reset(struct scsi_cmnd *sc);
375 extern int iscsi_eh_device_reset(struct scsi_cmnd *sc);
376 extern int iscsi_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *sc);
377 extern enum blk_eh_timer_return iscsi_eh_cmd_timed_out(struct scsi_cmnd *sc);
378
379 /*
380 * iSCSI host helpers.
381 */
382 #define iscsi_host_priv(_shost) \
383 (shost_priv(_shost) + sizeof(struct iscsi_host))
384
385 extern int iscsi_host_set_param(struct Scsi_Host *shost,
386 enum iscsi_host_param param, char *buf,
387 int buflen);
388 extern int iscsi_host_get_param(struct Scsi_Host *shost,
389 enum iscsi_host_param param, char *buf);
390 extern int iscsi_host_add(struct Scsi_Host *shost, struct device *pdev);
391 extern struct Scsi_Host *iscsi_host_alloc(struct scsi_host_template *sht,
392 int dd_data_size,
393 bool xmit_can_sleep);
394 extern void iscsi_host_remove(struct Scsi_Host *shost);
395 extern void iscsi_host_free(struct Scsi_Host *shost);
396 extern int iscsi_target_alloc(struct scsi_target *starget);
397 extern int iscsi_host_get_max_scsi_cmds(struct Scsi_Host *shost,
398 uint16_t requested_cmds_max);
399
400 /*
401 * session management
402 */
403 extern struct iscsi_cls_session *
404 iscsi_session_setup(struct iscsi_transport *, struct Scsi_Host *shost,
405 uint16_t, int, int, uint32_t, unsigned int);
406 extern void iscsi_session_teardown(struct iscsi_cls_session *);
407 extern void iscsi_session_recovery_timedout(struct iscsi_cls_session *);
408 extern int iscsi_set_param(struct iscsi_cls_conn *cls_conn,
409 enum iscsi_param param, char *buf, int buflen);
410 extern int iscsi_session_get_param(struct iscsi_cls_session *cls_session,
411 enum iscsi_param param, char *buf);
412
413 #define iscsi_session_printk(prefix, _sess, fmt, a...) \
414 iscsi_cls_session_printk(prefix, _sess->cls_session, fmt, ##a)
415
416 /*
417 * connection management
418 */
419 extern struct iscsi_cls_conn *iscsi_conn_setup(struct iscsi_cls_session *,
420 int, uint32_t);
421 extern void iscsi_conn_teardown(struct iscsi_cls_conn *);
422 extern int iscsi_conn_start(struct iscsi_cls_conn *);
423 extern void iscsi_conn_stop(struct iscsi_cls_conn *, int);
424 extern int iscsi_conn_bind(struct iscsi_cls_session *, struct iscsi_cls_conn *,
425 int);
426 extern void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err);
427 extern void iscsi_session_failure(struct iscsi_session *session,
428 enum iscsi_err err);
429 extern int iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
430 enum iscsi_param param, char *buf);
431 extern int iscsi_conn_get_addr_param(struct sockaddr_storage *addr,
432 enum iscsi_param param, char *buf);
433 extern void iscsi_suspend_tx(struct iscsi_conn *conn);
434 extern void iscsi_suspend_queue(struct iscsi_conn *conn);
435 extern void iscsi_conn_queue_work(struct iscsi_conn *conn);
436
437 #define iscsi_conn_printk(prefix, _c, fmt, a...) \
438 iscsi_cls_conn_printk(prefix, ((struct iscsi_conn *)_c)->cls_conn, \
439 fmt, ##a)
440
441 /*
442 * pdu and task processing
443 */
444 extern void iscsi_update_cmdsn(struct iscsi_session *, struct iscsi_nopin *);
445 extern void iscsi_prep_data_out_pdu(struct iscsi_task *task,
446 struct iscsi_r2t_info *r2t,
447 struct iscsi_data *hdr);
448 extern int iscsi_conn_send_pdu(struct iscsi_cls_conn *, struct iscsi_hdr *,
449 char *, uint32_t);
450 extern int iscsi_complete_pdu(struct iscsi_conn *, struct iscsi_hdr *,
451 char *, int);
452 extern int __iscsi_complete_pdu(struct iscsi_conn *, struct iscsi_hdr *,
453 char *, int);
454 extern int iscsi_verify_itt(struct iscsi_conn *, itt_t);
455 extern struct iscsi_task *iscsi_itt_to_ctask(struct iscsi_conn *, itt_t);
456 extern struct iscsi_task *iscsi_itt_to_task(struct iscsi_conn *, itt_t);
457 extern void iscsi_requeue_task(struct iscsi_task *task);
458 extern void iscsi_put_task(struct iscsi_task *task);
459 extern void __iscsi_put_task(struct iscsi_task *task);
460 extern void __iscsi_get_task(struct iscsi_task *task);
461 extern void iscsi_complete_scsi_task(struct iscsi_task *task,
462 uint32_t exp_cmdsn, uint32_t max_cmdsn);
463
464 /*
465 * generic helpers
466 */
467 extern void iscsi_pool_free(struct iscsi_pool *);
468 extern int iscsi_pool_init(struct iscsi_pool *, int, void ***, int);
469 extern int iscsi_switch_str_param(char **, char *);
470
471 /*
472 * inline functions to deal with padding.
473 */
474 static inline unsigned int
iscsi_padded(unsigned int len)475 iscsi_padded(unsigned int len)
476 {
477 return (len + ISCSI_PAD_LEN - 1) & ~(ISCSI_PAD_LEN - 1);
478 }
479
480 static inline unsigned int
iscsi_padding(unsigned int len)481 iscsi_padding(unsigned int len)
482 {
483 len &= (ISCSI_PAD_LEN - 1);
484 if (len)
485 len = ISCSI_PAD_LEN - len;
486 return len;
487 }
488
489 #endif
490