1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright (c) 2010 Cisco Systems, Inc.
4 */
5
6 /* XXX TBD some includes may be extraneous */
7
8 #include <linux/module.h>
9 #include <linux/moduleparam.h>
10 #include <linux/utsname.h>
11 #include <linux/init.h>
12 #include <linux/slab.h>
13 #include <linux/kthread.h>
14 #include <linux/types.h>
15 #include <linux/string.h>
16 #include <linux/configfs.h>
17 #include <linux/ctype.h>
18 #include <linux/hash.h>
19 #include <asm/unaligned.h>
20 #include <scsi/scsi_tcq.h>
21 #include <scsi/libfc.h>
22
23 #include <target/target_core_base.h>
24 #include <target/target_core_fabric.h>
25
26 #include "tcm_fc.h"
27
28 /*
29 * Dump cmd state for debugging.
30 */
_ft_dump_cmd(struct ft_cmd * cmd,const char * caller)31 static void _ft_dump_cmd(struct ft_cmd *cmd, const char *caller)
32 {
33 struct fc_exch *ep;
34 struct fc_seq *sp;
35 struct se_cmd *se_cmd;
36 struct scatterlist *sg;
37 int count;
38
39 se_cmd = &cmd->se_cmd;
40 pr_debug("%s: cmd %p sess %p seq %p se_cmd %p\n",
41 caller, cmd, cmd->sess, cmd->seq, se_cmd);
42
43 pr_debug("%s: cmd %p data_nents %u len %u se_cmd_flags <0x%x>\n",
44 caller, cmd, se_cmd->t_data_nents,
45 se_cmd->data_length, se_cmd->se_cmd_flags);
46
47 for_each_sg(se_cmd->t_data_sg, sg, se_cmd->t_data_nents, count)
48 pr_debug("%s: cmd %p sg %p page %p "
49 "len 0x%x off 0x%x\n",
50 caller, cmd, sg,
51 sg_page(sg), sg->length, sg->offset);
52
53 sp = cmd->seq;
54 if (sp) {
55 ep = fc_seq_exch(sp);
56 pr_debug("%s: cmd %p sid %x did %x "
57 "ox_id %x rx_id %x seq_id %x e_stat %x\n",
58 caller, cmd, ep->sid, ep->did, ep->oxid, ep->rxid,
59 sp->id, ep->esb_stat);
60 }
61 }
62
ft_dump_cmd(struct ft_cmd * cmd,const char * caller)63 void ft_dump_cmd(struct ft_cmd *cmd, const char *caller)
64 {
65 if (unlikely(ft_debug_logging))
66 _ft_dump_cmd(cmd, caller);
67 }
68
ft_free_cmd(struct ft_cmd * cmd)69 static void ft_free_cmd(struct ft_cmd *cmd)
70 {
71 struct fc_frame *fp;
72 struct ft_sess *sess;
73
74 if (!cmd)
75 return;
76 sess = cmd->sess;
77 fp = cmd->req_frame;
78 if (fr_seq(fp))
79 fc_seq_release(fr_seq(fp));
80 fc_frame_free(fp);
81 target_free_tag(sess->se_sess, &cmd->se_cmd);
82 ft_sess_put(sess); /* undo get from lookup at recv */
83 }
84
ft_release_cmd(struct se_cmd * se_cmd)85 void ft_release_cmd(struct se_cmd *se_cmd)
86 {
87 struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
88
89 ft_free_cmd(cmd);
90 }
91
ft_check_stop_free(struct se_cmd * se_cmd)92 int ft_check_stop_free(struct se_cmd *se_cmd)
93 {
94 return transport_generic_free_cmd(se_cmd, 0);
95 }
96
97 /*
98 * Send response.
99 */
ft_queue_status(struct se_cmd * se_cmd)100 int ft_queue_status(struct se_cmd *se_cmd)
101 {
102 struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
103 struct fc_frame *fp;
104 struct fcp_resp_with_ext *fcp;
105 struct fc_lport *lport;
106 struct fc_exch *ep;
107 size_t len;
108 int rc;
109
110 if (cmd->aborted)
111 return 0;
112 ft_dump_cmd(cmd, __func__);
113 ep = fc_seq_exch(cmd->seq);
114 lport = ep->lp;
115 len = sizeof(*fcp) + se_cmd->scsi_sense_length;
116 fp = fc_frame_alloc(lport, len);
117 if (!fp) {
118 se_cmd->scsi_status = SAM_STAT_TASK_SET_FULL;
119 return -ENOMEM;
120 }
121
122 fcp = fc_frame_payload_get(fp, len);
123 memset(fcp, 0, len);
124 fcp->resp.fr_status = se_cmd->scsi_status;
125
126 len = se_cmd->scsi_sense_length;
127 if (len) {
128 fcp->resp.fr_flags |= FCP_SNS_LEN_VAL;
129 fcp->ext.fr_sns_len = htonl(len);
130 memcpy((fcp + 1), se_cmd->sense_buffer, len);
131 }
132
133 /*
134 * Test underflow and overflow with one mask. Usually both are off.
135 * Bidirectional commands are not handled yet.
136 */
137 if (se_cmd->se_cmd_flags & (SCF_OVERFLOW_BIT | SCF_UNDERFLOW_BIT)) {
138 if (se_cmd->se_cmd_flags & SCF_OVERFLOW_BIT)
139 fcp->resp.fr_flags |= FCP_RESID_OVER;
140 else
141 fcp->resp.fr_flags |= FCP_RESID_UNDER;
142 fcp->ext.fr_resid = cpu_to_be32(se_cmd->residual_count);
143 }
144
145 /*
146 * Send response.
147 */
148 cmd->seq = fc_seq_start_next(cmd->seq);
149 fc_fill_fc_hdr(fp, FC_RCTL_DD_CMD_STATUS, ep->did, ep->sid, FC_TYPE_FCP,
150 FC_FC_EX_CTX | FC_FC_LAST_SEQ | FC_FC_END_SEQ, 0);
151
152 rc = fc_seq_send(lport, cmd->seq, fp);
153 if (rc) {
154 pr_info_ratelimited("%s: Failed to send response frame %p, "
155 "xid <0x%x>\n", __func__, fp, ep->xid);
156 /*
157 * Generate a TASK_SET_FULL status to notify the initiator
158 * to reduce it's queue_depth after the se_cmd response has
159 * been re-queued by target-core.
160 */
161 se_cmd->scsi_status = SAM_STAT_TASK_SET_FULL;
162 return -ENOMEM;
163 }
164 fc_exch_done(cmd->seq);
165 /*
166 * Drop the extra ACK_KREF reference taken by target_submit_cmd()
167 * ahead of ft_check_stop_free() -> transport_generic_free_cmd()
168 * final se_cmd->cmd_kref put.
169 */
170 target_put_sess_cmd(&cmd->se_cmd);
171 return 0;
172 }
173
174 /*
175 * Send TX_RDY (transfer ready).
176 */
ft_write_pending(struct se_cmd * se_cmd)177 int ft_write_pending(struct se_cmd *se_cmd)
178 {
179 struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
180 struct fc_frame *fp;
181 struct fcp_txrdy *txrdy;
182 struct fc_lport *lport;
183 struct fc_exch *ep;
184 struct fc_frame_header *fh;
185 u32 f_ctl;
186
187 ft_dump_cmd(cmd, __func__);
188
189 if (cmd->aborted)
190 return 0;
191 ep = fc_seq_exch(cmd->seq);
192 lport = ep->lp;
193 fp = fc_frame_alloc(lport, sizeof(*txrdy));
194 if (!fp)
195 return -ENOMEM; /* Signal QUEUE_FULL */
196
197 txrdy = fc_frame_payload_get(fp, sizeof(*txrdy));
198 memset(txrdy, 0, sizeof(*txrdy));
199 txrdy->ft_burst_len = htonl(se_cmd->data_length);
200
201 cmd->seq = fc_seq_start_next(cmd->seq);
202 fc_fill_fc_hdr(fp, FC_RCTL_DD_DATA_DESC, ep->did, ep->sid, FC_TYPE_FCP,
203 FC_FC_EX_CTX | FC_FC_END_SEQ | FC_FC_SEQ_INIT, 0);
204
205 fh = fc_frame_header_get(fp);
206 f_ctl = ntoh24(fh->fh_f_ctl);
207
208 /* Only if it is 'Exchange Responder' */
209 if (f_ctl & FC_FC_EX_CTX) {
210 /* Target is 'exchange responder' and sending XFER_READY
211 * to 'exchange initiator (initiator)'
212 */
213 if ((ep->xid <= lport->lro_xid) &&
214 (fh->fh_r_ctl == FC_RCTL_DD_DATA_DESC)) {
215 if ((se_cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) &&
216 lport->tt.ddp_target(lport, ep->xid,
217 se_cmd->t_data_sg,
218 se_cmd->t_data_nents))
219 cmd->was_ddp_setup = 1;
220 }
221 }
222 fc_seq_send(lport, cmd->seq, fp);
223 return 0;
224 }
225
ft_get_cmd_state(struct se_cmd * se_cmd)226 int ft_get_cmd_state(struct se_cmd *se_cmd)
227 {
228 return 0;
229 }
230
231 /*
232 * FC sequence response handler for follow-on sequences (data) and aborts.
233 */
ft_recv_seq(struct fc_seq * sp,struct fc_frame * fp,void * arg)234 static void ft_recv_seq(struct fc_seq *sp, struct fc_frame *fp, void *arg)
235 {
236 struct ft_cmd *cmd = arg;
237 struct fc_frame_header *fh;
238
239 if (IS_ERR(fp)) {
240 /* XXX need to find cmd if queued */
241 cmd->seq = NULL;
242 cmd->aborted = true;
243 return;
244 }
245
246 fh = fc_frame_header_get(fp);
247
248 switch (fh->fh_r_ctl) {
249 case FC_RCTL_DD_SOL_DATA: /* write data */
250 ft_recv_write_data(cmd, fp);
251 break;
252 case FC_RCTL_DD_UNSOL_CTL: /* command */
253 case FC_RCTL_DD_SOL_CTL: /* transfer ready */
254 case FC_RCTL_DD_DATA_DESC: /* transfer ready */
255 default:
256 pr_debug("%s: unhandled frame r_ctl %x\n",
257 __func__, fh->fh_r_ctl);
258 ft_invl_hw_context(cmd);
259 fc_frame_free(fp);
260 transport_generic_free_cmd(&cmd->se_cmd, 0);
261 break;
262 }
263 }
264
265 /*
266 * Send a FCP response including SCSI status and optional FCP rsp_code.
267 * status is SAM_STAT_GOOD (zero) iff code is valid.
268 * This is used in error cases, such as allocation failures.
269 */
ft_send_resp_status(struct fc_lport * lport,const struct fc_frame * rx_fp,u32 status,enum fcp_resp_rsp_codes code)270 static void ft_send_resp_status(struct fc_lport *lport,
271 const struct fc_frame *rx_fp,
272 u32 status, enum fcp_resp_rsp_codes code)
273 {
274 struct fc_frame *fp;
275 struct fc_seq *sp;
276 const struct fc_frame_header *fh;
277 size_t len;
278 struct fcp_resp_with_ext *fcp;
279 struct fcp_resp_rsp_info *info;
280
281 fh = fc_frame_header_get(rx_fp);
282 pr_debug("FCP error response: did %x oxid %x status %x code %x\n",
283 ntoh24(fh->fh_s_id), ntohs(fh->fh_ox_id), status, code);
284 len = sizeof(*fcp);
285 if (status == SAM_STAT_GOOD)
286 len += sizeof(*info);
287 fp = fc_frame_alloc(lport, len);
288 if (!fp)
289 return;
290 fcp = fc_frame_payload_get(fp, len);
291 memset(fcp, 0, len);
292 fcp->resp.fr_status = status;
293 if (status == SAM_STAT_GOOD) {
294 fcp->ext.fr_rsp_len = htonl(sizeof(*info));
295 fcp->resp.fr_flags |= FCP_RSP_LEN_VAL;
296 info = (struct fcp_resp_rsp_info *)(fcp + 1);
297 info->rsp_code = code;
298 }
299
300 fc_fill_reply_hdr(fp, rx_fp, FC_RCTL_DD_CMD_STATUS, 0);
301 sp = fr_seq(fp);
302 if (sp) {
303 fc_seq_send(lport, sp, fp);
304 fc_exch_done(sp);
305 } else {
306 lport->tt.frame_send(lport, fp);
307 }
308 }
309
310 /*
311 * Send error or task management response.
312 */
ft_send_resp_code(struct ft_cmd * cmd,enum fcp_resp_rsp_codes code)313 static void ft_send_resp_code(struct ft_cmd *cmd,
314 enum fcp_resp_rsp_codes code)
315 {
316 ft_send_resp_status(cmd->sess->tport->lport,
317 cmd->req_frame, SAM_STAT_GOOD, code);
318 }
319
320
321 /*
322 * Send error or task management response.
323 * Always frees the cmd and associated state.
324 */
ft_send_resp_code_and_free(struct ft_cmd * cmd,enum fcp_resp_rsp_codes code)325 static void ft_send_resp_code_and_free(struct ft_cmd *cmd,
326 enum fcp_resp_rsp_codes code)
327 {
328 ft_send_resp_code(cmd, code);
329 ft_free_cmd(cmd);
330 }
331
332 /*
333 * Handle Task Management Request.
334 */
ft_send_tm(struct ft_cmd * cmd)335 static void ft_send_tm(struct ft_cmd *cmd)
336 {
337 struct fcp_cmnd *fcp;
338 int rc;
339 u8 tm_func;
340
341 fcp = fc_frame_payload_get(cmd->req_frame, sizeof(*fcp));
342
343 switch (fcp->fc_tm_flags) {
344 case FCP_TMF_LUN_RESET:
345 tm_func = TMR_LUN_RESET;
346 break;
347 case FCP_TMF_TGT_RESET:
348 tm_func = TMR_TARGET_WARM_RESET;
349 break;
350 case FCP_TMF_CLR_TASK_SET:
351 tm_func = TMR_CLEAR_TASK_SET;
352 break;
353 case FCP_TMF_ABT_TASK_SET:
354 tm_func = TMR_ABORT_TASK_SET;
355 break;
356 case FCP_TMF_CLR_ACA:
357 tm_func = TMR_CLEAR_ACA;
358 break;
359 default:
360 /*
361 * FCP4r01 indicates having a combination of
362 * tm_flags set is invalid.
363 */
364 pr_debug("invalid FCP tm_flags %x\n", fcp->fc_tm_flags);
365 ft_send_resp_code_and_free(cmd, FCP_CMND_FIELDS_INVALID);
366 return;
367 }
368
369 /* FIXME: Add referenced task tag for ABORT_TASK */
370 rc = target_submit_tmr(&cmd->se_cmd, cmd->sess->se_sess,
371 &cmd->ft_sense_buffer[0], scsilun_to_int(&fcp->fc_lun),
372 cmd, tm_func, GFP_KERNEL, 0, TARGET_SCF_ACK_KREF);
373 if (rc < 0)
374 ft_send_resp_code_and_free(cmd, FCP_TMF_FAILED);
375 }
376
377 /*
378 * Send status from completed task management request.
379 */
ft_queue_tm_resp(struct se_cmd * se_cmd)380 void ft_queue_tm_resp(struct se_cmd *se_cmd)
381 {
382 struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
383 struct se_tmr_req *tmr = se_cmd->se_tmr_req;
384 enum fcp_resp_rsp_codes code;
385
386 if (cmd->aborted)
387 return;
388 switch (tmr->response) {
389 case TMR_FUNCTION_COMPLETE:
390 code = FCP_TMF_CMPL;
391 break;
392 case TMR_LUN_DOES_NOT_EXIST:
393 code = FCP_TMF_INVALID_LUN;
394 break;
395 case TMR_FUNCTION_REJECTED:
396 code = FCP_TMF_REJECTED;
397 break;
398 case TMR_TASK_DOES_NOT_EXIST:
399 case TMR_TASK_MGMT_FUNCTION_NOT_SUPPORTED:
400 default:
401 code = FCP_TMF_FAILED;
402 break;
403 }
404 pr_debug("tmr fn %d resp %d fcp code %d\n",
405 tmr->function, tmr->response, code);
406 ft_send_resp_code(cmd, code);
407 /*
408 * Drop the extra ACK_KREF reference taken by target_submit_tmr()
409 * ahead of ft_check_stop_free() -> transport_generic_free_cmd()
410 * final se_cmd->cmd_kref put.
411 */
412 target_put_sess_cmd(&cmd->se_cmd);
413 }
414
ft_aborted_task(struct se_cmd * se_cmd)415 void ft_aborted_task(struct se_cmd *se_cmd)
416 {
417 return;
418 }
419
420 static void ft_send_work(struct work_struct *work);
421
422 /*
423 * Handle incoming FCP command.
424 */
ft_recv_cmd(struct ft_sess * sess,struct fc_frame * fp)425 static void ft_recv_cmd(struct ft_sess *sess, struct fc_frame *fp)
426 {
427 struct ft_cmd *cmd;
428 struct fc_lport *lport = sess->tport->lport;
429 struct se_session *se_sess = sess->se_sess;
430 int tag, cpu;
431
432 tag = sbitmap_queue_get(&se_sess->sess_tag_pool, &cpu);
433 if (tag < 0)
434 goto busy;
435
436 cmd = &((struct ft_cmd *)se_sess->sess_cmd_map)[tag];
437 memset(cmd, 0, sizeof(struct ft_cmd));
438
439 cmd->se_cmd.map_tag = tag;
440 cmd->se_cmd.map_cpu = cpu;
441 cmd->sess = sess;
442 cmd->seq = fc_seq_assign(lport, fp);
443 if (!cmd->seq) {
444 target_free_tag(se_sess, &cmd->se_cmd);
445 goto busy;
446 }
447 cmd->req_frame = fp; /* hold frame during cmd */
448
449 INIT_WORK(&cmd->work, ft_send_work);
450 queue_work(sess->tport->tpg->workqueue, &cmd->work);
451 return;
452
453 busy:
454 pr_debug("cmd or seq allocation failure - sending BUSY\n");
455 ft_send_resp_status(lport, fp, SAM_STAT_BUSY, 0);
456 fc_frame_free(fp);
457 ft_sess_put(sess); /* undo get from lookup */
458 }
459
460
461 /*
462 * Handle incoming FCP frame.
463 * Caller has verified that the frame is type FCP.
464 */
ft_recv_req(struct ft_sess * sess,struct fc_frame * fp)465 void ft_recv_req(struct ft_sess *sess, struct fc_frame *fp)
466 {
467 struct fc_frame_header *fh = fc_frame_header_get(fp);
468
469 switch (fh->fh_r_ctl) {
470 case FC_RCTL_DD_UNSOL_CMD: /* command */
471 ft_recv_cmd(sess, fp);
472 break;
473 case FC_RCTL_DD_SOL_DATA: /* write data */
474 case FC_RCTL_DD_UNSOL_CTL:
475 case FC_RCTL_DD_SOL_CTL:
476 case FC_RCTL_DD_DATA_DESC: /* transfer ready */
477 case FC_RCTL_ELS4_REQ: /* SRR, perhaps */
478 default:
479 pr_debug("%s: unhandled frame r_ctl %x\n",
480 __func__, fh->fh_r_ctl);
481 fc_frame_free(fp);
482 ft_sess_put(sess); /* undo get from lookup */
483 break;
484 }
485 }
486
487 /*
488 * Send new command to target.
489 */
ft_send_work(struct work_struct * work)490 static void ft_send_work(struct work_struct *work)
491 {
492 struct ft_cmd *cmd = container_of(work, struct ft_cmd, work);
493 struct fc_frame_header *fh = fc_frame_header_get(cmd->req_frame);
494 struct fcp_cmnd *fcp;
495 int data_dir = 0;
496 int task_attr;
497
498 fcp = fc_frame_payload_get(cmd->req_frame, sizeof(*fcp));
499 if (!fcp)
500 goto err;
501
502 if (fcp->fc_flags & FCP_CFL_LEN_MASK)
503 goto err; /* not handling longer CDBs yet */
504
505 /*
506 * Check for FCP task management flags
507 */
508 if (fcp->fc_tm_flags) {
509 ft_send_tm(cmd);
510 return;
511 }
512
513 switch (fcp->fc_flags & (FCP_CFL_RDDATA | FCP_CFL_WRDATA)) {
514 case 0:
515 data_dir = DMA_NONE;
516 break;
517 case FCP_CFL_RDDATA:
518 data_dir = DMA_FROM_DEVICE;
519 break;
520 case FCP_CFL_WRDATA:
521 data_dir = DMA_TO_DEVICE;
522 break;
523 case FCP_CFL_WRDATA | FCP_CFL_RDDATA:
524 goto err; /* TBD not supported by tcm_fc yet */
525 }
526 /*
527 * Locate the SAM Task Attr from fc_pri_ta
528 */
529 switch (fcp->fc_pri_ta & FCP_PTA_MASK) {
530 case FCP_PTA_HEADQ:
531 task_attr = TCM_HEAD_TAG;
532 break;
533 case FCP_PTA_ORDERED:
534 task_attr = TCM_ORDERED_TAG;
535 break;
536 case FCP_PTA_ACA:
537 task_attr = TCM_ACA_TAG;
538 break;
539 case FCP_PTA_SIMPLE:
540 default:
541 task_attr = TCM_SIMPLE_TAG;
542 }
543
544 fc_seq_set_resp(cmd->seq, ft_recv_seq, cmd);
545 cmd->se_cmd.tag = fc_seq_exch(cmd->seq)->rxid;
546
547 /*
548 * Use a single se_cmd->cmd_kref as we expect to release se_cmd
549 * directly from ft_check_stop_free callback in response path.
550 */
551 if (target_init_cmd(&cmd->se_cmd, cmd->sess->se_sess,
552 &cmd->ft_sense_buffer[0],
553 scsilun_to_int(&fcp->fc_lun), ntohl(fcp->fc_dl),
554 task_attr, data_dir, TARGET_SCF_ACK_KREF))
555 goto err;
556
557 if (target_submit_prep(&cmd->se_cmd, fcp->fc_cdb, NULL, 0, NULL, 0,
558 NULL, 0, GFP_KERNEL))
559 return;
560
561 target_submit(&cmd->se_cmd);
562 pr_debug("r_ctl %x target_submit_cmd %p\n", fh->fh_r_ctl, cmd);
563 return;
564
565 err:
566 ft_send_resp_code_and_free(cmd, FCP_CMND_FIELDS_INVALID);
567 }
568