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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
25struct scsi_transport_template;
26struct scsi_host_template;
27struct scsi_device;
28struct Scsi_Host;
29struct scsi_target;
30struct scsi_cmnd;
31struct socket;
32struct iscsi_transport;
33struct iscsi_cls_session;
34struct iscsi_cls_conn;
35struct iscsi_session;
36struct iscsi_nopin;
37struct 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 */
45enum {
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
70enum {
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
78enum {
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
88struct 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
99struct 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
138static 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
143static inline void* iscsi_next_hdr(struct iscsi_task *task)
144{
145 return (void*)task->hdr + task->hdr_len;
146}
147
148static 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/* Private data associated with struct scsi_cmnd. */
156struct iscsi_cmd {
157 struct iscsi_task *task;
158 int age;
159};
160
161static inline struct iscsi_cmd *iscsi_cmd(struct scsi_cmnd *cmd)
162{
163 return scsi_cmd_priv(cmd);
164}
165
166/* Connection's states */
167enum {
168 ISCSI_CONN_INITIAL_STAGE,
169 ISCSI_CONN_STARTED,
170 ISCSI_CONN_STOPPED,
171 ISCSI_CONN_CLEANUP_WAIT,
172};
173
174struct iscsi_conn {
175 struct iscsi_cls_conn *cls_conn; /* ptr to class connection */
176 void *dd_data; /* iscsi_transport data */
177 struct iscsi_session *session; /* parent session */
178 /*
179 * conn_stop() flag: stop to recover, stop to terminate
180 */
181 int stop_stage;
182 struct timer_list transport_timer;
183 unsigned long last_recv;
184 unsigned long last_ping;
185 int ping_timeout;
186 int recv_timeout;
187 struct iscsi_task *ping_task;
188
189 /* iSCSI connection-wide sequencing */
190 uint32_t exp_statsn;
191 uint32_t statsn;
192
193 /* control data */
194 int id; /* CID */
195 int c_stage; /* connection state */
196 /*
197 * Preallocated buffer for pdus that have data but do not
198 * originate from scsi-ml. We never have two pdus using the
199 * buffer at the same time. It is only allocated to
200 * the default max recv size because the pdus we support
201 * should always fit in this buffer
202 */
203 char *data;
204 struct iscsi_task *login_task; /* mtask used for login/text */
205 struct iscsi_task *task; /* xmit task in progress */
206
207 /* xmit */
208 /* items must be added/deleted under frwd lock */
209 struct list_head mgmtqueue; /* mgmt (control) xmit queue */
210 struct list_head cmdqueue; /* data-path cmd queue */
211 struct list_head requeue; /* tasks needing another run */
212 struct work_struct xmitwork; /* per-conn. xmit workqueue */
213 /* recv */
214 struct work_struct recvwork;
215 unsigned long flags; /* ISCSI_CONN_FLAGs */
216
217 /* negotiated params */
218 unsigned max_recv_dlength; /* initiator_max_recv_dsl*/
219 unsigned max_xmit_dlength; /* target_max_recv_dsl */
220 int hdrdgst_en;
221 int datadgst_en;
222 int ifmarker_en;
223 int ofmarker_en;
224 /* values userspace uses to id a conn */
225 int persistent_port;
226 char *persistent_address;
227
228 unsigned max_segment_size;
229 unsigned tcp_xmit_wsf;
230 unsigned tcp_recv_wsf;
231 uint16_t keepalive_tmo;
232 uint16_t local_port;
233 uint8_t tcp_timestamp_stat;
234 uint8_t tcp_nagle_disable;
235 uint8_t tcp_wsf_disable;
236 uint8_t tcp_timer_scale;
237 uint8_t tcp_timestamp_en;
238 uint8_t fragment_disable;
239 uint8_t ipv4_tos;
240 uint8_t ipv6_traffic_class;
241 uint8_t ipv6_flow_label;
242 uint8_t is_fw_assigned_ipv6;
243 char *local_ipaddr;
244
245 /* MIB-statistics */
246 uint64_t txdata_octets;
247 uint64_t rxdata_octets;
248 uint32_t scsicmd_pdus_cnt;
249 uint32_t dataout_pdus_cnt;
250 uint32_t scsirsp_pdus_cnt;
251 uint32_t datain_pdus_cnt;
252 uint32_t r2t_pdus_cnt;
253 uint32_t tmfcmd_pdus_cnt;
254 int32_t tmfrsp_pdus_cnt;
255
256 /* custom statistics */
257 uint32_t eh_abort_cnt;
258 uint32_t fmr_unalign_cnt;
259};
260
261struct iscsi_pool {
262 struct kfifo queue; /* FIFO Queue */
263 void **pool; /* Pool of elements */
264 int max; /* Max number of elements */
265};
266
267/* Session's states */
268enum {
269 ISCSI_STATE_FREE = 1,
270 ISCSI_STATE_LOGGED_IN,
271 ISCSI_STATE_FAILED,
272 ISCSI_STATE_TERMINATE,
273 ISCSI_STATE_IN_RECOVERY,
274 ISCSI_STATE_RECOVERY_FAILED,
275 ISCSI_STATE_LOGGING_OUT,
276};
277
278struct iscsi_session {
279 struct iscsi_cls_session *cls_session;
280 /*
281 * Syncs up the scsi eh thread with the iscsi eh thread when sending
282 * task management functions. This must be taken before the session
283 * and recv lock.
284 */
285 struct mutex eh_mutex;
286 /* abort */
287 wait_queue_head_t ehwait; /* used in eh_abort() */
288 struct iscsi_tm tmhdr;
289 struct timer_list tmf_timer;
290 int tmf_state; /* see TMF_INITIAL, etc.*/
291 struct iscsi_task *running_aborted_task;
292
293 /* iSCSI session-wide sequencing */
294 uint32_t cmdsn;
295 uint32_t exp_cmdsn;
296 uint32_t max_cmdsn;
297
298 /* This tracks the reqs queued into the initiator */
299 uint32_t queued_cmdsn;
300
301 /* configuration */
302 int abort_timeout;
303 int lu_reset_timeout;
304 int tgt_reset_timeout;
305 int initial_r2t_en;
306 unsigned short max_r2t;
307 int imm_data_en;
308 unsigned first_burst;
309 unsigned max_burst;
310 int time2wait;
311 int time2retain;
312 int pdu_inorder_en;
313 int dataseq_inorder_en;
314 int erl;
315 int fast_abort;
316 int tpgt;
317 char *username;
318 char *username_in;
319 char *password;
320 char *password_in;
321 char *targetname;
322 char *targetalias;
323 char *ifacename;
324 char *initiatorname;
325 char *boot_root;
326 char *boot_nic;
327 char *boot_target;
328 char *portal_type;
329 char *discovery_parent_type;
330 uint16_t discovery_parent_idx;
331 uint16_t def_taskmgmt_tmo;
332 uint16_t tsid;
333 uint8_t auto_snd_tgt_disable;
334 uint8_t discovery_sess;
335 uint8_t chap_auth_en;
336 uint8_t discovery_logout_en;
337 uint8_t bidi_chap_en;
338 uint8_t discovery_auth_optional;
339 uint8_t isid[ISID_SIZE];
340
341 /* control data */
342 struct iscsi_transport *tt;
343 struct Scsi_Host *host;
344 struct iscsi_conn *leadconn; /* leading connection */
345 /* Between the forward and the backward locks exists a strict locking
346 * hierarchy. The mutual exclusion zone protected by the forward lock
347 * can enclose the mutual exclusion zone protected by the backward lock
348 * but not vice versa.
349 */
350 spinlock_t frwd_lock; /* protects session state, *
351 * cmdsn, queued_cmdsn *
352 * session resources: *
353 * - cmdpool kfifo_out , *
354 * - mgmtpool, queues */
355 spinlock_t back_lock; /* protects cmdsn_exp *
356 * cmdsn_max, *
357 * cmdpool kfifo_in */
358 int state; /* session state */
359 int age; /* counts session re-opens */
360
361 int scsi_cmds_max; /* max scsi commands */
362 int cmds_max; /* size of cmds array */
363 struct iscsi_task **cmds; /* Original Cmds arr */
364 struct iscsi_pool cmdpool; /* PDU's pool */
365 void *dd_data; /* LLD private data */
366};
367
368enum {
369 ISCSI_HOST_SETUP,
370 ISCSI_HOST_REMOVED,
371};
372
373struct iscsi_host {
374 char *initiatorname;
375 /* hw address or netdev iscsi connection is bound to */
376 char *hwaddress;
377 char *netdev;
378
379 wait_queue_head_t session_removal_wq;
380 /* protects sessions and state */
381 spinlock_t lock;
382 int num_sessions;
383 int state;
384
385 struct workqueue_struct *workq;
386};
387
388/*
389 * scsi host template
390 */
391extern int iscsi_eh_abort(struct scsi_cmnd *sc);
392extern int iscsi_eh_recover_target(struct scsi_cmnd *sc);
393extern int iscsi_eh_session_reset(struct scsi_cmnd *sc);
394extern int iscsi_eh_device_reset(struct scsi_cmnd *sc);
395extern enum scsi_qc_status iscsi_queuecommand(struct Scsi_Host *host,
396 struct scsi_cmnd *sc);
397extern enum scsi_timeout_action 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
405extern int iscsi_host_set_param(struct Scsi_Host *shost,
406 enum iscsi_host_param param, char *buf,
407 int buflen);
408extern int iscsi_host_get_param(struct Scsi_Host *shost,
409 enum iscsi_host_param param, char *buf);
410extern int iscsi_host_add(struct Scsi_Host *shost, struct device *pdev);
411extern struct Scsi_Host *iscsi_host_alloc(const struct scsi_host_template *sht,
412 int dd_data_size,
413 bool xmit_can_sleep);
414extern void iscsi_host_remove(struct Scsi_Host *shost, bool is_shutdown);
415extern void iscsi_host_free(struct Scsi_Host *shost);
416extern int iscsi_target_alloc(struct scsi_target *starget);
417extern int iscsi_host_get_max_scsi_cmds(struct Scsi_Host *shost,
418 uint16_t requested_cmds_max);
419
420/*
421 * session management
422 */
423extern struct iscsi_cls_session *
424iscsi_session_setup(struct iscsi_transport *, struct Scsi_Host *shost,
425 uint16_t, int, int, uint32_t, unsigned int);
426void iscsi_session_remove(struct iscsi_cls_session *cls_session);
427void iscsi_session_free(struct iscsi_cls_session *cls_session);
428extern void iscsi_session_teardown(struct iscsi_cls_session *);
429extern void iscsi_session_recovery_timedout(struct iscsi_cls_session *);
430extern int iscsi_set_param(struct iscsi_cls_conn *cls_conn,
431 enum iscsi_param param, char *buf, int buflen);
432extern int iscsi_session_get_param(struct iscsi_cls_session *cls_session,
433 enum iscsi_param param, char *buf);
434
435#define iscsi_session_printk(prefix, _sess, fmt, a...) \
436 iscsi_cls_session_printk(prefix, _sess->cls_session, fmt, ##a)
437
438/*
439 * connection management
440 */
441extern struct iscsi_cls_conn *iscsi_conn_setup(struct iscsi_cls_session *,
442 int, uint32_t);
443extern void iscsi_conn_teardown(struct iscsi_cls_conn *);
444extern int iscsi_conn_start(struct iscsi_cls_conn *);
445extern void iscsi_conn_stop(struct iscsi_cls_conn *, int);
446extern int iscsi_conn_bind(struct iscsi_cls_session *, struct iscsi_cls_conn *,
447 int);
448extern void iscsi_conn_unbind(struct iscsi_cls_conn *cls_conn, bool is_active);
449extern void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err);
450extern void iscsi_session_failure(struct iscsi_session *session,
451 enum iscsi_err err);
452extern int iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
453 enum iscsi_param param, char *buf);
454extern int iscsi_conn_get_addr_param(struct sockaddr_storage *addr,
455 enum iscsi_param param, char *buf);
456extern void iscsi_suspend_tx(struct iscsi_conn *conn);
457extern void iscsi_suspend_rx(struct iscsi_conn *conn);
458extern void iscsi_suspend_queue(struct iscsi_conn *conn);
459extern void iscsi_conn_queue_xmit(struct iscsi_conn *conn);
460extern void iscsi_conn_queue_recv(struct iscsi_conn *conn);
461
462#define iscsi_conn_printk(prefix, _c, fmt, a...) \
463 iscsi_cls_conn_printk(prefix, ((struct iscsi_conn *)_c)->cls_conn, \
464 fmt, ##a)
465
466/*
467 * pdu and task processing
468 */
469extern void iscsi_update_cmdsn(struct iscsi_session *, struct iscsi_nopin *);
470extern void iscsi_prep_data_out_pdu(struct iscsi_task *task,
471 struct iscsi_r2t_info *r2t,
472 struct iscsi_data *hdr);
473extern int iscsi_conn_send_pdu(struct iscsi_cls_conn *, struct iscsi_hdr *,
474 char *, uint32_t);
475extern int iscsi_complete_pdu(struct iscsi_conn *, struct iscsi_hdr *,
476 char *, int);
477extern int __iscsi_complete_pdu(struct iscsi_conn *, struct iscsi_hdr *,
478 char *, int);
479extern int iscsi_verify_itt(struct iscsi_conn *, itt_t);
480extern struct iscsi_task *iscsi_itt_to_ctask(struct iscsi_conn *, itt_t);
481extern struct iscsi_task *iscsi_itt_to_task(struct iscsi_conn *, itt_t);
482extern void iscsi_requeue_task(struct iscsi_task *task);
483extern void iscsi_put_task(struct iscsi_task *task);
484extern void __iscsi_put_task(struct iscsi_task *task);
485extern bool iscsi_get_task(struct iscsi_task *task);
486extern void iscsi_complete_scsi_task(struct iscsi_task *task,
487 uint32_t exp_cmdsn, uint32_t max_cmdsn);
488
489/*
490 * generic helpers
491 */
492extern void iscsi_pool_free(struct iscsi_pool *);
493extern int iscsi_pool_init(struct iscsi_pool *, int, void ***, int);
494extern int iscsi_switch_str_param(char **, char *);
495
496/*
497 * inline functions to deal with padding.
498 */
499static inline unsigned int
500iscsi_padded(unsigned int len)
501{
502 return (len + ISCSI_PAD_LEN - 1) & ~(ISCSI_PAD_LEN - 1);
503}
504
505static inline unsigned int
506iscsi_padding(unsigned int len)
507{
508 len &= (ISCSI_PAD_LEN - 1);
509 if (len)
510 len = ISCSI_PAD_LEN - len;
511 return len;
512}
513
514#endif