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