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
iscsi_task_has_unsol_data(struct iscsi_task * task)135 static inline int iscsi_task_has_unsol_data(struct iscsi_task *task)
136 {
137 return task->unsol_r2t.data_length > task->unsol_r2t.sent;
138 }
139
iscsi_next_hdr(struct iscsi_task * task)140 static inline void* iscsi_next_hdr(struct iscsi_task *task)
141 {
142 return (void*)task->hdr + task->hdr_len;
143 }
144
145 /* Connection's states */
146 enum {
147 ISCSI_CONN_INITIAL_STAGE,
148 ISCSI_CONN_STARTED,
149 ISCSI_CONN_STOPPED,
150 ISCSI_CONN_CLEANUP_WAIT,
151 };
152
153 struct iscsi_conn {
154 struct iscsi_cls_conn *cls_conn; /* ptr to class connection */
155 void *dd_data; /* iscsi_transport data */
156 struct iscsi_session *session; /* parent session */
157 /*
158 * conn_stop() flag: stop to recover, stop to terminate
159 */
160 int stop_stage;
161 struct timer_list transport_timer;
162 unsigned long last_recv;
163 unsigned long last_ping;
164 int ping_timeout;
165 int recv_timeout;
166 struct iscsi_task *ping_task;
167
168 /* iSCSI connection-wide sequencing */
169 uint32_t exp_statsn;
170 uint32_t statsn;
171
172 /* control data */
173 int id; /* CID */
174 int c_stage; /* connection state */
175 /*
176 * Preallocated buffer for pdus that have data but do not
177 * originate from scsi-ml. We never have two pdus using the
178 * buffer at the same time. It is only allocated to
179 * the default max recv size because the pdus we support
180 * should always fit in this buffer
181 */
182 char *data;
183 struct iscsi_task *login_task; /* mtask used for login/text */
184 struct iscsi_task *task; /* xmit task in progress */
185
186 /* xmit */
187 spinlock_t taskqueuelock; /* protects the next three lists */
188 struct list_head mgmtqueue; /* mgmt (control) xmit queue */
189 struct list_head cmdqueue; /* data-path cmd queue */
190 struct list_head requeue; /* tasks needing another run */
191 struct work_struct xmitwork; /* per-conn. xmit workqueue */
192 unsigned long suspend_tx; /* suspend Tx */
193 unsigned long suspend_rx; /* suspend Rx */
194
195 /* abort */
196 wait_queue_head_t ehwait; /* used in eh_abort() */
197 struct iscsi_tm tmhdr;
198 struct timer_list tmf_timer;
199 int tmf_state; /* see TMF_INITIAL, etc.*/
200
201 /* negotiated params */
202 unsigned max_recv_dlength; /* initiator_max_recv_dsl*/
203 unsigned max_xmit_dlength; /* target_max_recv_dsl */
204 int hdrdgst_en;
205 int datadgst_en;
206 int ifmarker_en;
207 int ofmarker_en;
208 /* values userspace uses to id a conn */
209 int persistent_port;
210 char *persistent_address;
211
212 unsigned max_segment_size;
213 unsigned tcp_xmit_wsf;
214 unsigned tcp_recv_wsf;
215 uint16_t keepalive_tmo;
216 uint16_t local_port;
217 uint8_t tcp_timestamp_stat;
218 uint8_t tcp_nagle_disable;
219 uint8_t tcp_wsf_disable;
220 uint8_t tcp_timer_scale;
221 uint8_t tcp_timestamp_en;
222 uint8_t fragment_disable;
223 uint8_t ipv4_tos;
224 uint8_t ipv6_traffic_class;
225 uint8_t ipv6_flow_label;
226 uint8_t is_fw_assigned_ipv6;
227 char *local_ipaddr;
228
229 /* MIB-statistics */
230 uint64_t txdata_octets;
231 uint64_t rxdata_octets;
232 uint32_t scsicmd_pdus_cnt;
233 uint32_t dataout_pdus_cnt;
234 uint32_t scsirsp_pdus_cnt;
235 uint32_t datain_pdus_cnt;
236 uint32_t r2t_pdus_cnt;
237 uint32_t tmfcmd_pdus_cnt;
238 int32_t tmfrsp_pdus_cnt;
239
240 /* custom statistics */
241 uint32_t eh_abort_cnt;
242 uint32_t fmr_unalign_cnt;
243 };
244
245 struct iscsi_pool {
246 struct kfifo queue; /* FIFO Queue */
247 void **pool; /* Pool of elements */
248 int max; /* Max number of elements */
249 };
250
251 /* Session's states */
252 enum {
253 ISCSI_STATE_FREE = 1,
254 ISCSI_STATE_LOGGED_IN,
255 ISCSI_STATE_FAILED,
256 ISCSI_STATE_TERMINATE,
257 ISCSI_STATE_IN_RECOVERY,
258 ISCSI_STATE_RECOVERY_FAILED,
259 ISCSI_STATE_LOGGING_OUT,
260 };
261
262 struct iscsi_session {
263 struct iscsi_cls_session *cls_session;
264 /*
265 * Syncs up the scsi eh thread with the iscsi eh thread when sending
266 * task management functions. This must be taken before the session
267 * and recv lock.
268 */
269 struct mutex eh_mutex;
270
271 /* iSCSI session-wide sequencing */
272 uint32_t cmdsn;
273 uint32_t exp_cmdsn;
274 uint32_t max_cmdsn;
275
276 /* This tracks the reqs queued into the initiator */
277 uint32_t queued_cmdsn;
278
279 /* configuration */
280 int abort_timeout;
281 int lu_reset_timeout;
282 int tgt_reset_timeout;
283 int initial_r2t_en;
284 unsigned short max_r2t;
285 int imm_data_en;
286 unsigned first_burst;
287 unsigned max_burst;
288 int time2wait;
289 int time2retain;
290 int pdu_inorder_en;
291 int dataseq_inorder_en;
292 int erl;
293 int fast_abort;
294 int tpgt;
295 char *username;
296 char *username_in;
297 char *password;
298 char *password_in;
299 char *targetname;
300 char *targetalias;
301 char *ifacename;
302 char *initiatorname;
303 char *boot_root;
304 char *boot_nic;
305 char *boot_target;
306 char *portal_type;
307 char *discovery_parent_type;
308 uint16_t discovery_parent_idx;
309 uint16_t def_taskmgmt_tmo;
310 uint16_t tsid;
311 uint8_t auto_snd_tgt_disable;
312 uint8_t discovery_sess;
313 uint8_t chap_auth_en;
314 uint8_t discovery_logout_en;
315 uint8_t bidi_chap_en;
316 uint8_t discovery_auth_optional;
317 uint8_t isid[ISID_SIZE];
318
319 /* control data */
320 struct iscsi_transport *tt;
321 struct Scsi_Host *host;
322 struct iscsi_conn *leadconn; /* leading connection */
323 /* Between the forward and the backward locks exists a strict locking
324 * hierarchy. The mutual exclusion zone protected by the forward lock
325 * can enclose the mutual exclusion zone protected by the backward lock
326 * but not vice versa.
327 */
328 spinlock_t frwd_lock; /* protects session state, *
329 * cmdsn, queued_cmdsn *
330 * session resources: *
331 * - cmdpool kfifo_out , *
332 * - mgmtpool, */
333 spinlock_t back_lock; /* protects cmdsn_exp *
334 * cmdsn_max, *
335 * cmdpool kfifo_in */
336 int state; /* session state */
337 int age; /* counts session re-opens */
338
339 int scsi_cmds_max; /* max scsi commands */
340 int cmds_max; /* size of cmds array */
341 struct iscsi_task **cmds; /* Original Cmds arr */
342 struct iscsi_pool cmdpool; /* PDU's pool */
343 void *dd_data; /* LLD private data */
344 };
345
346 enum {
347 ISCSI_HOST_SETUP,
348 ISCSI_HOST_REMOVED,
349 };
350
351 struct iscsi_host {
352 char *initiatorname;
353 /* hw address or netdev iscsi connection is bound to */
354 char *hwaddress;
355 char *netdev;
356
357 wait_queue_head_t session_removal_wq;
358 /* protects sessions and state */
359 spinlock_t lock;
360 int num_sessions;
361 int state;
362
363 struct workqueue_struct *workq;
364 char workq_name[20];
365 };
366
367 /*
368 * scsi host template
369 */
370 extern int iscsi_eh_abort(struct scsi_cmnd *sc);
371 extern int iscsi_eh_recover_target(struct scsi_cmnd *sc);
372 extern int iscsi_eh_session_reset(struct scsi_cmnd *sc);
373 extern int iscsi_eh_device_reset(struct scsi_cmnd *sc);
374 extern int iscsi_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *sc);
375 extern enum blk_eh_timer_return iscsi_eh_cmd_timed_out(struct scsi_cmnd *sc);
376
377 /*
378 * iSCSI host helpers.
379 */
380 #define iscsi_host_priv(_shost) \
381 (shost_priv(_shost) + sizeof(struct iscsi_host))
382
383 extern int iscsi_host_set_param(struct Scsi_Host *shost,
384 enum iscsi_host_param param, char *buf,
385 int buflen);
386 extern int iscsi_host_get_param(struct Scsi_Host *shost,
387 enum iscsi_host_param param, char *buf);
388 extern int iscsi_host_add(struct Scsi_Host *shost, struct device *pdev);
389 extern struct Scsi_Host *iscsi_host_alloc(struct scsi_host_template *sht,
390 int dd_data_size,
391 bool xmit_can_sleep);
392 extern void iscsi_host_remove(struct Scsi_Host *shost);
393 extern void iscsi_host_free(struct Scsi_Host *shost);
394 extern int iscsi_target_alloc(struct scsi_target *starget);
395
396 /*
397 * session management
398 */
399 extern struct iscsi_cls_session *
400 iscsi_session_setup(struct iscsi_transport *, struct Scsi_Host *shost,
401 uint16_t, int, int, uint32_t, unsigned int);
402 extern void iscsi_session_teardown(struct iscsi_cls_session *);
403 extern void iscsi_session_recovery_timedout(struct iscsi_cls_session *);
404 extern int iscsi_set_param(struct iscsi_cls_conn *cls_conn,
405 enum iscsi_param param, char *buf, int buflen);
406 extern int iscsi_session_get_param(struct iscsi_cls_session *cls_session,
407 enum iscsi_param param, char *buf);
408
409 #define iscsi_session_printk(prefix, _sess, fmt, a...) \
410 iscsi_cls_session_printk(prefix, _sess->cls_session, fmt, ##a)
411
412 /*
413 * connection management
414 */
415 extern struct iscsi_cls_conn *iscsi_conn_setup(struct iscsi_cls_session *,
416 int, uint32_t);
417 extern void iscsi_conn_teardown(struct iscsi_cls_conn *);
418 extern int iscsi_conn_start(struct iscsi_cls_conn *);
419 extern void iscsi_conn_stop(struct iscsi_cls_conn *, int);
420 extern int iscsi_conn_bind(struct iscsi_cls_session *, struct iscsi_cls_conn *,
421 int);
422 extern void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err);
423 extern void iscsi_session_failure(struct iscsi_session *session,
424 enum iscsi_err err);
425 extern int iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
426 enum iscsi_param param, char *buf);
427 extern int iscsi_conn_get_addr_param(struct sockaddr_storage *addr,
428 enum iscsi_param param, char *buf);
429 extern void iscsi_suspend_tx(struct iscsi_conn *conn);
430 extern void iscsi_suspend_queue(struct iscsi_conn *conn);
431 extern void iscsi_conn_queue_work(struct iscsi_conn *conn);
432
433 #define iscsi_conn_printk(prefix, _c, fmt, a...) \
434 iscsi_cls_conn_printk(prefix, ((struct iscsi_conn *)_c)->cls_conn, \
435 fmt, ##a)
436
437 /*
438 * pdu and task processing
439 */
440 extern void iscsi_update_cmdsn(struct iscsi_session *, struct iscsi_nopin *);
441 extern void iscsi_prep_data_out_pdu(struct iscsi_task *task,
442 struct iscsi_r2t_info *r2t,
443 struct iscsi_data *hdr);
444 extern int iscsi_conn_send_pdu(struct iscsi_cls_conn *, struct iscsi_hdr *,
445 char *, uint32_t);
446 extern int iscsi_complete_pdu(struct iscsi_conn *, struct iscsi_hdr *,
447 char *, int);
448 extern int __iscsi_complete_pdu(struct iscsi_conn *, struct iscsi_hdr *,
449 char *, int);
450 extern int iscsi_verify_itt(struct iscsi_conn *, itt_t);
451 extern struct iscsi_task *iscsi_itt_to_ctask(struct iscsi_conn *, itt_t);
452 extern struct iscsi_task *iscsi_itt_to_task(struct iscsi_conn *, itt_t);
453 extern void iscsi_requeue_task(struct iscsi_task *task);
454 extern void iscsi_put_task(struct iscsi_task *task);
455 extern void __iscsi_put_task(struct iscsi_task *task);
456 extern void __iscsi_get_task(struct iscsi_task *task);
457 extern void iscsi_complete_scsi_task(struct iscsi_task *task,
458 uint32_t exp_cmdsn, uint32_t max_cmdsn);
459
460 /*
461 * generic helpers
462 */
463 extern void iscsi_pool_free(struct iscsi_pool *);
464 extern int iscsi_pool_init(struct iscsi_pool *, int, void ***, int);
465 extern int iscsi_switch_str_param(char **, char *);
466
467 /*
468 * inline functions to deal with padding.
469 */
470 static inline unsigned int
iscsi_padded(unsigned int len)471 iscsi_padded(unsigned int len)
472 {
473 return (len + ISCSI_PAD_LEN - 1) & ~(ISCSI_PAD_LEN - 1);
474 }
475
476 static inline unsigned int
iscsi_padding(unsigned int len)477 iscsi_padding(unsigned int len)
478 {
479 len &= (ISCSI_PAD_LEN - 1);
480 if (len)
481 len = ISCSI_PAD_LEN - len;
482 return len;
483 }
484
485 #endif
486
