1 /*
2 * Copyright (c) 2010 Cisco Systems, Inc.
3 *
4 * This program is free software; you can redistribute it and/or modify it
5 * under the terms and conditions of the GNU General Public License,
6 * version 2, as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope it will be useful, but WITHOUT
9 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
11 * more details.
12 *
13 * You should have received a copy of the GNU General Public License along with
14 * this program; if not, write to the Free Software Foundation, Inc.,
15 * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
16 */
17
18 /* XXX TBD some includes may be extraneous */
19
20 #include <linux/module.h>
21 #include <linux/moduleparam.h>
22 #include <generated/utsrelease.h>
23 #include <linux/utsname.h>
24 #include <linux/init.h>
25 #include <linux/slab.h>
26 #include <linux/kthread.h>
27 #include <linux/types.h>
28 #include <linux/string.h>
29 #include <linux/configfs.h>
30 #include <linux/ctype.h>
31 #include <linux/hash.h>
32 #include <asm/unaligned.h>
33 #include <scsi/scsi.h>
34 #include <scsi/scsi_host.h>
35 #include <scsi/scsi_device.h>
36 #include <scsi/scsi_cmnd.h>
37 #include <scsi/scsi_tcq.h>
38 #include <scsi/libfc.h>
39 #include <scsi/fc_encode.h>
40
41 #include <target/target_core_base.h>
42 #include <target/target_core_fabric.h>
43 #include <target/target_core_configfs.h>
44 #include <target/configfs_macros.h>
45
46 #include "tcm_fc.h"
47
48 /*
49 * Dump cmd state for debugging.
50 */
ft_dump_cmd(struct ft_cmd * cmd,const char * caller)51 void ft_dump_cmd(struct ft_cmd *cmd, const char *caller)
52 {
53 struct fc_exch *ep;
54 struct fc_seq *sp;
55 struct se_cmd *se_cmd;
56 struct scatterlist *sg;
57 int count;
58
59 se_cmd = &cmd->se_cmd;
60 pr_debug("%s: cmd %p sess %p seq %p se_cmd %p\n",
61 caller, cmd, cmd->sess, cmd->seq, se_cmd);
62
63 pr_debug("%s: cmd %p data_nents %u len %u se_cmd_flags <0x%x>\n",
64 caller, cmd, se_cmd->t_data_nents,
65 se_cmd->data_length, se_cmd->se_cmd_flags);
66
67 for_each_sg(se_cmd->t_data_sg, sg, se_cmd->t_data_nents, count)
68 pr_debug("%s: cmd %p sg %p page %p "
69 "len 0x%x off 0x%x\n",
70 caller, cmd, sg,
71 sg_page(sg), sg->length, sg->offset);
72
73 sp = cmd->seq;
74 if (sp) {
75 ep = fc_seq_exch(sp);
76 pr_debug("%s: cmd %p sid %x did %x "
77 "ox_id %x rx_id %x seq_id %x e_stat %x\n",
78 caller, cmd, ep->sid, ep->did, ep->oxid, ep->rxid,
79 sp->id, ep->esb_stat);
80 }
81 }
82
ft_free_cmd(struct ft_cmd * cmd)83 static void ft_free_cmd(struct ft_cmd *cmd)
84 {
85 struct fc_frame *fp;
86 struct fc_lport *lport;
87
88 if (!cmd)
89 return;
90 fp = cmd->req_frame;
91 lport = fr_dev(fp);
92 if (fr_seq(fp))
93 lport->tt.seq_release(fr_seq(fp));
94 fc_frame_free(fp);
95 ft_sess_put(cmd->sess); /* undo get from lookup at recv */
96 kfree(cmd);
97 }
98
ft_release_cmd(struct se_cmd * se_cmd)99 void ft_release_cmd(struct se_cmd *se_cmd)
100 {
101 struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
102
103 ft_free_cmd(cmd);
104 }
105
ft_check_stop_free(struct se_cmd * se_cmd)106 int ft_check_stop_free(struct se_cmd *se_cmd)
107 {
108 transport_generic_free_cmd(se_cmd, 0);
109 return 1;
110 }
111
112 /*
113 * Send response.
114 */
ft_queue_status(struct se_cmd * se_cmd)115 int ft_queue_status(struct se_cmd *se_cmd)
116 {
117 struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
118 struct fc_frame *fp;
119 struct fcp_resp_with_ext *fcp;
120 struct fc_lport *lport;
121 struct fc_exch *ep;
122 size_t len;
123
124 if (cmd->aborted)
125 return 0;
126 ft_dump_cmd(cmd, __func__);
127 ep = fc_seq_exch(cmd->seq);
128 lport = ep->lp;
129 len = sizeof(*fcp) + se_cmd->scsi_sense_length;
130 fp = fc_frame_alloc(lport, len);
131 if (!fp) {
132 /* XXX shouldn't just drop it - requeue and retry? */
133 return 0;
134 }
135 fcp = fc_frame_payload_get(fp, len);
136 memset(fcp, 0, len);
137 fcp->resp.fr_status = se_cmd->scsi_status;
138
139 len = se_cmd->scsi_sense_length;
140 if (len) {
141 fcp->resp.fr_flags |= FCP_SNS_LEN_VAL;
142 fcp->ext.fr_sns_len = htonl(len);
143 memcpy((fcp + 1), se_cmd->sense_buffer, len);
144 }
145
146 /*
147 * Test underflow and overflow with one mask. Usually both are off.
148 * Bidirectional commands are not handled yet.
149 */
150 if (se_cmd->se_cmd_flags & (SCF_OVERFLOW_BIT | SCF_UNDERFLOW_BIT)) {
151 if (se_cmd->se_cmd_flags & SCF_OVERFLOW_BIT)
152 fcp->resp.fr_flags |= FCP_RESID_OVER;
153 else
154 fcp->resp.fr_flags |= FCP_RESID_UNDER;
155 fcp->ext.fr_resid = cpu_to_be32(se_cmd->residual_count);
156 }
157
158 /*
159 * Send response.
160 */
161 cmd->seq = lport->tt.seq_start_next(cmd->seq);
162 fc_fill_fc_hdr(fp, FC_RCTL_DD_CMD_STATUS, ep->did, ep->sid, FC_TYPE_FCP,
163 FC_FC_EX_CTX | FC_FC_LAST_SEQ | FC_FC_END_SEQ, 0);
164
165 lport->tt.seq_send(lport, cmd->seq, fp);
166 lport->tt.exch_done(cmd->seq);
167 return 0;
168 }
169
ft_write_pending_status(struct se_cmd * se_cmd)170 int ft_write_pending_status(struct se_cmd *se_cmd)
171 {
172 struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
173
174 return cmd->write_data_len != se_cmd->data_length;
175 }
176
177 /*
178 * Send TX_RDY (transfer ready).
179 */
ft_write_pending(struct se_cmd * se_cmd)180 int ft_write_pending(struct se_cmd *se_cmd)
181 {
182 struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
183 struct fc_frame *fp;
184 struct fcp_txrdy *txrdy;
185 struct fc_lport *lport;
186 struct fc_exch *ep;
187 struct fc_frame_header *fh;
188 u32 f_ctl;
189
190 ft_dump_cmd(cmd, __func__);
191
192 if (cmd->aborted)
193 return 0;
194 ep = fc_seq_exch(cmd->seq);
195 lport = ep->lp;
196 fp = fc_frame_alloc(lport, sizeof(*txrdy));
197 if (!fp)
198 return -ENOMEM; /* Signal QUEUE_FULL */
199
200 txrdy = fc_frame_payload_get(fp, sizeof(*txrdy));
201 memset(txrdy, 0, sizeof(*txrdy));
202 txrdy->ft_burst_len = htonl(se_cmd->data_length);
203
204 cmd->seq = lport->tt.seq_start_next(cmd->seq);
205 fc_fill_fc_hdr(fp, FC_RCTL_DD_DATA_DESC, ep->did, ep->sid, FC_TYPE_FCP,
206 FC_FC_EX_CTX | FC_FC_END_SEQ | FC_FC_SEQ_INIT, 0);
207
208 fh = fc_frame_header_get(fp);
209 f_ctl = ntoh24(fh->fh_f_ctl);
210
211 /* Only if it is 'Exchange Responder' */
212 if (f_ctl & FC_FC_EX_CTX) {
213 /* Target is 'exchange responder' and sending XFER_READY
214 * to 'exchange initiator (initiator)'
215 */
216 if ((ep->xid <= lport->lro_xid) &&
217 (fh->fh_r_ctl == FC_RCTL_DD_DATA_DESC)) {
218 if (se_cmd->se_cmd_flags & SCF_SCSI_DATA_SG_IO_CDB) {
219 /*
220 * cmd may have been broken up into multiple
221 * tasks. Link their sgs together so we can
222 * operate on them all at once.
223 */
224 transport_do_task_sg_chain(se_cmd);
225 cmd->sg = se_cmd->t_tasks_sg_chained;
226 cmd->sg_cnt =
227 se_cmd->t_tasks_sg_chained_no;
228 }
229 if (cmd->sg && lport->tt.ddp_target(lport, ep->xid,
230 cmd->sg,
231 cmd->sg_cnt))
232 cmd->was_ddp_setup = 1;
233 }
234 }
235 lport->tt.seq_send(lport, cmd->seq, fp);
236 return 0;
237 }
238
ft_get_task_tag(struct se_cmd * se_cmd)239 u32 ft_get_task_tag(struct se_cmd *se_cmd)
240 {
241 struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
242
243 if (cmd->aborted)
244 return ~0;
245 return fc_seq_exch(cmd->seq)->rxid;
246 }
247
ft_get_cmd_state(struct se_cmd * se_cmd)248 int ft_get_cmd_state(struct se_cmd *se_cmd)
249 {
250 return 0;
251 }
252
253 /*
254 * FC sequence response handler for follow-on sequences (data) and aborts.
255 */
ft_recv_seq(struct fc_seq * sp,struct fc_frame * fp,void * arg)256 static void ft_recv_seq(struct fc_seq *sp, struct fc_frame *fp, void *arg)
257 {
258 struct ft_cmd *cmd = arg;
259 struct fc_frame_header *fh;
260
261 if (unlikely(IS_ERR(fp))) {
262 /* XXX need to find cmd if queued */
263 cmd->seq = NULL;
264 cmd->aborted = true;
265 return;
266 }
267
268 fh = fc_frame_header_get(fp);
269
270 switch (fh->fh_r_ctl) {
271 case FC_RCTL_DD_SOL_DATA: /* write data */
272 ft_recv_write_data(cmd, fp);
273 break;
274 case FC_RCTL_DD_UNSOL_CTL: /* command */
275 case FC_RCTL_DD_SOL_CTL: /* transfer ready */
276 case FC_RCTL_DD_DATA_DESC: /* transfer ready */
277 default:
278 pr_debug("%s: unhandled frame r_ctl %x\n",
279 __func__, fh->fh_r_ctl);
280 ft_invl_hw_context(cmd);
281 fc_frame_free(fp);
282 transport_generic_free_cmd(&cmd->se_cmd, 0);
283 break;
284 }
285 }
286
287 /*
288 * Send a FCP response including SCSI status and optional FCP rsp_code.
289 * status is SAM_STAT_GOOD (zero) iff code is valid.
290 * This is used in error cases, such as allocation failures.
291 */
ft_send_resp_status(struct fc_lport * lport,const struct fc_frame * rx_fp,u32 status,enum fcp_resp_rsp_codes code)292 static void ft_send_resp_status(struct fc_lport *lport,
293 const struct fc_frame *rx_fp,
294 u32 status, enum fcp_resp_rsp_codes code)
295 {
296 struct fc_frame *fp;
297 struct fc_seq *sp;
298 const struct fc_frame_header *fh;
299 size_t len;
300 struct fcp_resp_with_ext *fcp;
301 struct fcp_resp_rsp_info *info;
302
303 fh = fc_frame_header_get(rx_fp);
304 pr_debug("FCP error response: did %x oxid %x status %x code %x\n",
305 ntoh24(fh->fh_s_id), ntohs(fh->fh_ox_id), status, code);
306 len = sizeof(*fcp);
307 if (status == SAM_STAT_GOOD)
308 len += sizeof(*info);
309 fp = fc_frame_alloc(lport, len);
310 if (!fp)
311 return;
312 fcp = fc_frame_payload_get(fp, len);
313 memset(fcp, 0, len);
314 fcp->resp.fr_status = status;
315 if (status == SAM_STAT_GOOD) {
316 fcp->ext.fr_rsp_len = htonl(sizeof(*info));
317 fcp->resp.fr_flags |= FCP_RSP_LEN_VAL;
318 info = (struct fcp_resp_rsp_info *)(fcp + 1);
319 info->rsp_code = code;
320 }
321
322 fc_fill_reply_hdr(fp, rx_fp, FC_RCTL_DD_CMD_STATUS, 0);
323 sp = fr_seq(fp);
324 if (sp) {
325 lport->tt.seq_send(lport, sp, fp);
326 lport->tt.exch_done(sp);
327 } else {
328 lport->tt.frame_send(lport, fp);
329 }
330 }
331
332 /*
333 * Send error or task management response.
334 */
ft_send_resp_code(struct ft_cmd * cmd,enum fcp_resp_rsp_codes code)335 static void ft_send_resp_code(struct ft_cmd *cmd,
336 enum fcp_resp_rsp_codes code)
337 {
338 ft_send_resp_status(cmd->sess->tport->lport,
339 cmd->req_frame, SAM_STAT_GOOD, code);
340 }
341
342
343 /*
344 * Send error or task management response.
345 * Always frees the cmd and associated state.
346 */
ft_send_resp_code_and_free(struct ft_cmd * cmd,enum fcp_resp_rsp_codes code)347 static void ft_send_resp_code_and_free(struct ft_cmd *cmd,
348 enum fcp_resp_rsp_codes code)
349 {
350 ft_send_resp_code(cmd, code);
351 ft_free_cmd(cmd);
352 }
353
354 /*
355 * Handle Task Management Request.
356 */
ft_send_tm(struct ft_cmd * cmd)357 static void ft_send_tm(struct ft_cmd *cmd)
358 {
359 struct fcp_cmnd *fcp;
360 int rc;
361 u8 tm_func;
362
363 fcp = fc_frame_payload_get(cmd->req_frame, sizeof(*fcp));
364
365 switch (fcp->fc_tm_flags) {
366 case FCP_TMF_LUN_RESET:
367 tm_func = TMR_LUN_RESET;
368 break;
369 case FCP_TMF_TGT_RESET:
370 tm_func = TMR_TARGET_WARM_RESET;
371 break;
372 case FCP_TMF_CLR_TASK_SET:
373 tm_func = TMR_CLEAR_TASK_SET;
374 break;
375 case FCP_TMF_ABT_TASK_SET:
376 tm_func = TMR_ABORT_TASK_SET;
377 break;
378 case FCP_TMF_CLR_ACA:
379 tm_func = TMR_CLEAR_ACA;
380 break;
381 default:
382 /*
383 * FCP4r01 indicates having a combination of
384 * tm_flags set is invalid.
385 */
386 pr_debug("invalid FCP tm_flags %x\n", fcp->fc_tm_flags);
387 ft_send_resp_code_and_free(cmd, FCP_CMND_FIELDS_INVALID);
388 return;
389 }
390
391 /* FIXME: Add referenced task tag for ABORT_TASK */
392 rc = target_submit_tmr(&cmd->se_cmd, cmd->sess->se_sess,
393 &cmd->ft_sense_buffer[0], scsilun_to_int(&fcp->fc_lun),
394 cmd, tm_func, GFP_KERNEL, 0, 0);
395 if (rc < 0)
396 ft_send_resp_code_and_free(cmd, FCP_TMF_FAILED);
397 }
398
399 /*
400 * Send status from completed task management request.
401 */
ft_queue_tm_resp(struct se_cmd * se_cmd)402 int ft_queue_tm_resp(struct se_cmd *se_cmd)
403 {
404 struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
405 struct se_tmr_req *tmr = se_cmd->se_tmr_req;
406 enum fcp_resp_rsp_codes code;
407
408 if (cmd->aborted)
409 return 0;
410 switch (tmr->response) {
411 case TMR_FUNCTION_COMPLETE:
412 code = FCP_TMF_CMPL;
413 break;
414 case TMR_LUN_DOES_NOT_EXIST:
415 code = FCP_TMF_INVALID_LUN;
416 break;
417 case TMR_FUNCTION_REJECTED:
418 code = FCP_TMF_REJECTED;
419 break;
420 case TMR_TASK_DOES_NOT_EXIST:
421 case TMR_TASK_STILL_ALLEGIANT:
422 case TMR_TASK_FAILOVER_NOT_SUPPORTED:
423 case TMR_TASK_MGMT_FUNCTION_NOT_SUPPORTED:
424 case TMR_FUNCTION_AUTHORIZATION_FAILED:
425 default:
426 code = FCP_TMF_FAILED;
427 break;
428 }
429 pr_debug("tmr fn %d resp %d fcp code %d\n",
430 tmr->function, tmr->response, code);
431 ft_send_resp_code(cmd, code);
432 return 0;
433 }
434
435 static void ft_send_work(struct work_struct *work);
436
437 /*
438 * Handle incoming FCP command.
439 */
ft_recv_cmd(struct ft_sess * sess,struct fc_frame * fp)440 static void ft_recv_cmd(struct ft_sess *sess, struct fc_frame *fp)
441 {
442 struct ft_cmd *cmd;
443 struct fc_lport *lport = sess->tport->lport;
444
445 cmd = kzalloc(sizeof(*cmd), GFP_ATOMIC);
446 if (!cmd)
447 goto busy;
448 cmd->sess = sess;
449 cmd->seq = lport->tt.seq_assign(lport, fp);
450 if (!cmd->seq) {
451 kfree(cmd);
452 goto busy;
453 }
454 cmd->req_frame = fp; /* hold frame during cmd */
455
456 INIT_WORK(&cmd->work, ft_send_work);
457 queue_work(sess->tport->tpg->workqueue, &cmd->work);
458 return;
459
460 busy:
461 pr_debug("cmd or seq allocation failure - sending BUSY\n");
462 ft_send_resp_status(lport, fp, SAM_STAT_BUSY, 0);
463 fc_frame_free(fp);
464 ft_sess_put(sess); /* undo get from lookup */
465 }
466
467
468 /*
469 * Handle incoming FCP frame.
470 * Caller has verified that the frame is type FCP.
471 */
ft_recv_req(struct ft_sess * sess,struct fc_frame * fp)472 void ft_recv_req(struct ft_sess *sess, struct fc_frame *fp)
473 {
474 struct fc_frame_header *fh = fc_frame_header_get(fp);
475
476 switch (fh->fh_r_ctl) {
477 case FC_RCTL_DD_UNSOL_CMD: /* command */
478 ft_recv_cmd(sess, fp);
479 break;
480 case FC_RCTL_DD_SOL_DATA: /* write data */
481 case FC_RCTL_DD_UNSOL_CTL:
482 case FC_RCTL_DD_SOL_CTL:
483 case FC_RCTL_DD_DATA_DESC: /* transfer ready */
484 case FC_RCTL_ELS4_REQ: /* SRR, perhaps */
485 default:
486 pr_debug("%s: unhandled frame r_ctl %x\n",
487 __func__, fh->fh_r_ctl);
488 fc_frame_free(fp);
489 ft_sess_put(sess); /* undo get from lookup */
490 break;
491 }
492 }
493
494 /*
495 * Send new command to target.
496 */
ft_send_work(struct work_struct * work)497 static void ft_send_work(struct work_struct *work)
498 {
499 struct ft_cmd *cmd = container_of(work, struct ft_cmd, work);
500 struct fc_frame_header *fh = fc_frame_header_get(cmd->req_frame);
501 struct fcp_cmnd *fcp;
502 int data_dir = 0;
503 int task_attr;
504
505 fcp = fc_frame_payload_get(cmd->req_frame, sizeof(*fcp));
506 if (!fcp)
507 goto err;
508
509 if (fcp->fc_flags & FCP_CFL_LEN_MASK)
510 goto err; /* not handling longer CDBs yet */
511
512 /*
513 * Check for FCP task management flags
514 */
515 if (fcp->fc_tm_flags) {
516 ft_send_tm(cmd);
517 return;
518 }
519
520 switch (fcp->fc_flags & (FCP_CFL_RDDATA | FCP_CFL_WRDATA)) {
521 case 0:
522 data_dir = DMA_NONE;
523 break;
524 case FCP_CFL_RDDATA:
525 data_dir = DMA_FROM_DEVICE;
526 break;
527 case FCP_CFL_WRDATA:
528 data_dir = DMA_TO_DEVICE;
529 break;
530 case FCP_CFL_WRDATA | FCP_CFL_RDDATA:
531 goto err; /* TBD not supported by tcm_fc yet */
532 }
533 /*
534 * Locate the SAM Task Attr from fc_pri_ta
535 */
536 switch (fcp->fc_pri_ta & FCP_PTA_MASK) {
537 case FCP_PTA_HEADQ:
538 task_attr = MSG_HEAD_TAG;
539 break;
540 case FCP_PTA_ORDERED:
541 task_attr = MSG_ORDERED_TAG;
542 break;
543 case FCP_PTA_ACA:
544 task_attr = MSG_ACA_TAG;
545 break;
546 case FCP_PTA_SIMPLE: /* Fallthrough */
547 default:
548 task_attr = MSG_SIMPLE_TAG;
549 }
550
551 fc_seq_exch(cmd->seq)->lp->tt.seq_set_resp(cmd->seq, ft_recv_seq, cmd);
552 /*
553 * Use a single se_cmd->cmd_kref as we expect to release se_cmd
554 * directly from ft_check_stop_free callback in response path.
555 */
556 target_submit_cmd(&cmd->se_cmd, cmd->sess->se_sess, fcp->fc_cdb,
557 &cmd->ft_sense_buffer[0], scsilun_to_int(&fcp->fc_lun),
558 ntohl(fcp->fc_dl), task_attr, data_dir, 0);
559 pr_debug("r_ctl %x alloc target_submit_cmd\n", fh->fh_r_ctl);
560 return;
561
562 err:
563 ft_send_resp_code_and_free(cmd, FCP_CMND_FIELDS_INVALID);
564 }
565