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 */ 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 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 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 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 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 */ 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 */ 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 } 225 226 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 */ 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 */ 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 */ 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 */ 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 */ 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 */ 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 } 414 415 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 */ 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 */ 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 */ 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