1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * iSCSI Initiator over TCP/IP Data-Path 4 * 5 * Copyright (C) 2004 Dmitry Yusupov 6 * Copyright (C) 2004 Alex Aizman 7 * Copyright (C) 2005 - 2006 Mike Christie 8 * Copyright (C) 2006 Red Hat, Inc. All rights reserved. 9 * maintained by open-iscsi@googlegroups.com 10 * 11 * See the file COPYING included with this distribution for more details. 12 * 13 * Credits: 14 * Christoph Hellwig 15 * FUJITA Tomonori 16 * Arne Redlich 17 * Zhenyu Wang 18 */ 19 20 #include <crypto/hash.h> 21 #include <linux/types.h> 22 #include <linux/inet.h> 23 #include <linux/slab.h> 24 #include <linux/sched/mm.h> 25 #include <linux/file.h> 26 #include <linux/blkdev.h> 27 #include <linux/delay.h> 28 #include <linux/kfifo.h> 29 #include <linux/scatterlist.h> 30 #include <linux/module.h> 31 #include <linux/backing-dev.h> 32 #include <net/tcp.h> 33 #include <scsi/scsi_cmnd.h> 34 #include <scsi/scsi_device.h> 35 #include <scsi/scsi_host.h> 36 #include <scsi/scsi.h> 37 #include <scsi/scsi_transport_iscsi.h> 38 #include <trace/events/iscsi.h> 39 40 #include "iscsi_tcp.h" 41 42 MODULE_AUTHOR("Mike Christie <michaelc@cs.wisc.edu>, " 43 "Dmitry Yusupov <dmitry_yus@yahoo.com>, " 44 "Alex Aizman <itn780@yahoo.com>"); 45 MODULE_DESCRIPTION("iSCSI/TCP data-path"); 46 MODULE_LICENSE("GPL"); 47 48 static struct scsi_transport_template *iscsi_sw_tcp_scsi_transport; 49 static struct scsi_host_template iscsi_sw_tcp_sht; 50 static struct iscsi_transport iscsi_sw_tcp_transport; 51 52 static unsigned int iscsi_max_lun = ~0; 53 module_param_named(max_lun, iscsi_max_lun, uint, S_IRUGO); 54 55 static int iscsi_sw_tcp_dbg; 56 module_param_named(debug_iscsi_tcp, iscsi_sw_tcp_dbg, int, 57 S_IRUGO | S_IWUSR); 58 MODULE_PARM_DESC(debug_iscsi_tcp, "Turn on debugging for iscsi_tcp module " 59 "Set to 1 to turn on, and zero to turn off. Default is off."); 60 61 #define ISCSI_SW_TCP_DBG(_conn, dbg_fmt, arg...) \ 62 do { \ 63 if (iscsi_sw_tcp_dbg) \ 64 iscsi_conn_printk(KERN_INFO, _conn, \ 65 "%s " dbg_fmt, \ 66 __func__, ##arg); \ 67 iscsi_dbg_trace(trace_iscsi_dbg_sw_tcp, \ 68 &(_conn)->cls_conn->dev, \ 69 "%s " dbg_fmt, __func__, ##arg);\ 70 } while (0); 71 72 73 /** 74 * iscsi_sw_tcp_recv - TCP receive in sendfile fashion 75 * @rd_desc: read descriptor 76 * @skb: socket buffer 77 * @offset: offset in skb 78 * @len: skb->len - offset 79 */ 80 static int iscsi_sw_tcp_recv(read_descriptor_t *rd_desc, struct sk_buff *skb, 81 unsigned int offset, size_t len) 82 { 83 struct iscsi_conn *conn = rd_desc->arg.data; 84 unsigned int consumed, total_consumed = 0; 85 int status; 86 87 ISCSI_SW_TCP_DBG(conn, "in %d bytes\n", skb->len - offset); 88 89 do { 90 status = 0; 91 consumed = iscsi_tcp_recv_skb(conn, skb, offset, 0, &status); 92 offset += consumed; 93 total_consumed += consumed; 94 } while (consumed != 0 && status != ISCSI_TCP_SKB_DONE); 95 96 ISCSI_SW_TCP_DBG(conn, "read %d bytes status %d\n", 97 skb->len - offset, status); 98 return total_consumed; 99 } 100 101 /** 102 * iscsi_sw_sk_state_check - check socket state 103 * @sk: socket 104 * 105 * If the socket is in CLOSE or CLOSE_WAIT we should 106 * not close the connection if there is still some 107 * data pending. 108 * 109 * Must be called with sk_callback_lock. 110 */ 111 static inline int iscsi_sw_sk_state_check(struct sock *sk) 112 { 113 struct iscsi_conn *conn = sk->sk_user_data; 114 115 if ((sk->sk_state == TCP_CLOSE_WAIT || sk->sk_state == TCP_CLOSE) && 116 (conn->session->state != ISCSI_STATE_LOGGING_OUT) && 117 !atomic_read(&sk->sk_rmem_alloc)) { 118 ISCSI_SW_TCP_DBG(conn, "TCP_CLOSE|TCP_CLOSE_WAIT\n"); 119 iscsi_conn_failure(conn, ISCSI_ERR_TCP_CONN_CLOSE); 120 return -ECONNRESET; 121 } 122 return 0; 123 } 124 125 static void iscsi_sw_tcp_data_ready(struct sock *sk) 126 { 127 struct iscsi_conn *conn; 128 struct iscsi_tcp_conn *tcp_conn; 129 read_descriptor_t rd_desc; 130 131 read_lock_bh(&sk->sk_callback_lock); 132 conn = sk->sk_user_data; 133 if (!conn) { 134 read_unlock_bh(&sk->sk_callback_lock); 135 return; 136 } 137 tcp_conn = conn->dd_data; 138 139 /* 140 * Use rd_desc to pass 'conn' to iscsi_tcp_recv. 141 * We set count to 1 because we want the network layer to 142 * hand us all the skbs that are available. iscsi_tcp_recv 143 * handled pdus that cross buffers or pdus that still need data. 144 */ 145 rd_desc.arg.data = conn; 146 rd_desc.count = 1; 147 tcp_read_sock(sk, &rd_desc, iscsi_sw_tcp_recv); 148 149 iscsi_sw_sk_state_check(sk); 150 151 /* If we had to (atomically) map a highmem page, 152 * unmap it now. */ 153 iscsi_tcp_segment_unmap(&tcp_conn->in.segment); 154 read_unlock_bh(&sk->sk_callback_lock); 155 } 156 157 static void iscsi_sw_tcp_state_change(struct sock *sk) 158 { 159 struct iscsi_tcp_conn *tcp_conn; 160 struct iscsi_sw_tcp_conn *tcp_sw_conn; 161 struct iscsi_conn *conn; 162 void (*old_state_change)(struct sock *); 163 164 read_lock_bh(&sk->sk_callback_lock); 165 conn = sk->sk_user_data; 166 if (!conn) { 167 read_unlock_bh(&sk->sk_callback_lock); 168 return; 169 } 170 171 iscsi_sw_sk_state_check(sk); 172 173 tcp_conn = conn->dd_data; 174 tcp_sw_conn = tcp_conn->dd_data; 175 old_state_change = tcp_sw_conn->old_state_change; 176 177 read_unlock_bh(&sk->sk_callback_lock); 178 179 old_state_change(sk); 180 } 181 182 /** 183 * iscsi_write_space - Called when more output buffer space is available 184 * @sk: socket space is available for 185 **/ 186 static void iscsi_sw_tcp_write_space(struct sock *sk) 187 { 188 struct iscsi_conn *conn; 189 struct iscsi_tcp_conn *tcp_conn; 190 struct iscsi_sw_tcp_conn *tcp_sw_conn; 191 void (*old_write_space)(struct sock *); 192 193 read_lock_bh(&sk->sk_callback_lock); 194 conn = sk->sk_user_data; 195 if (!conn) { 196 read_unlock_bh(&sk->sk_callback_lock); 197 return; 198 } 199 200 tcp_conn = conn->dd_data; 201 tcp_sw_conn = tcp_conn->dd_data; 202 old_write_space = tcp_sw_conn->old_write_space; 203 read_unlock_bh(&sk->sk_callback_lock); 204 205 old_write_space(sk); 206 207 ISCSI_SW_TCP_DBG(conn, "iscsi_write_space\n"); 208 iscsi_conn_queue_work(conn); 209 } 210 211 static void iscsi_sw_tcp_conn_set_callbacks(struct iscsi_conn *conn) 212 { 213 struct iscsi_tcp_conn *tcp_conn = conn->dd_data; 214 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; 215 struct sock *sk = tcp_sw_conn->sock->sk; 216 217 /* assign new callbacks */ 218 write_lock_bh(&sk->sk_callback_lock); 219 sk->sk_user_data = conn; 220 tcp_sw_conn->old_data_ready = sk->sk_data_ready; 221 tcp_sw_conn->old_state_change = sk->sk_state_change; 222 tcp_sw_conn->old_write_space = sk->sk_write_space; 223 sk->sk_data_ready = iscsi_sw_tcp_data_ready; 224 sk->sk_state_change = iscsi_sw_tcp_state_change; 225 sk->sk_write_space = iscsi_sw_tcp_write_space; 226 write_unlock_bh(&sk->sk_callback_lock); 227 } 228 229 static void 230 iscsi_sw_tcp_conn_restore_callbacks(struct iscsi_conn *conn) 231 { 232 struct iscsi_tcp_conn *tcp_conn = conn->dd_data; 233 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; 234 struct sock *sk = tcp_sw_conn->sock->sk; 235 236 /* restore socket callbacks, see also: iscsi_conn_set_callbacks() */ 237 write_lock_bh(&sk->sk_callback_lock); 238 sk->sk_user_data = NULL; 239 sk->sk_data_ready = tcp_sw_conn->old_data_ready; 240 sk->sk_state_change = tcp_sw_conn->old_state_change; 241 sk->sk_write_space = tcp_sw_conn->old_write_space; 242 sk->sk_no_check_tx = 0; 243 write_unlock_bh(&sk->sk_callback_lock); 244 } 245 246 /** 247 * iscsi_sw_tcp_xmit_segment - transmit segment 248 * @tcp_conn: the iSCSI TCP connection 249 * @segment: the buffer to transmnit 250 * 251 * This function transmits as much of the buffer as 252 * the network layer will accept, and returns the number of 253 * bytes transmitted. 254 * 255 * If CRC hashing is enabled, the function will compute the 256 * hash as it goes. When the entire segment has been transmitted, 257 * it will retrieve the hash value and send it as well. 258 */ 259 static int iscsi_sw_tcp_xmit_segment(struct iscsi_tcp_conn *tcp_conn, 260 struct iscsi_segment *segment) 261 { 262 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; 263 struct socket *sk = tcp_sw_conn->sock; 264 unsigned int copied = 0; 265 int r = 0; 266 267 while (!iscsi_tcp_segment_done(tcp_conn, segment, 0, r)) { 268 struct scatterlist *sg; 269 unsigned int offset, copy; 270 int flags = 0; 271 272 r = 0; 273 offset = segment->copied; 274 copy = segment->size - offset; 275 276 if (segment->total_copied + segment->size < segment->total_size) 277 flags |= MSG_MORE; 278 279 /* Use sendpage if we can; else fall back to sendmsg */ 280 if (!segment->data) { 281 sg = segment->sg; 282 offset += segment->sg_offset + sg->offset; 283 r = tcp_sw_conn->sendpage(sk, sg_page(sg), offset, 284 copy, flags); 285 } else { 286 struct msghdr msg = { .msg_flags = flags }; 287 struct kvec iov = { 288 .iov_base = segment->data + offset, 289 .iov_len = copy 290 }; 291 292 r = kernel_sendmsg(sk, &msg, &iov, 1, copy); 293 } 294 295 if (r < 0) { 296 iscsi_tcp_segment_unmap(segment); 297 return r; 298 } 299 copied += r; 300 } 301 return copied; 302 } 303 304 /** 305 * iscsi_sw_tcp_xmit - TCP transmit 306 * @conn: iscsi connection 307 **/ 308 static int iscsi_sw_tcp_xmit(struct iscsi_conn *conn) 309 { 310 struct iscsi_tcp_conn *tcp_conn = conn->dd_data; 311 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; 312 struct iscsi_segment *segment = &tcp_sw_conn->out.segment; 313 unsigned int consumed = 0; 314 int rc = 0; 315 316 while (1) { 317 rc = iscsi_sw_tcp_xmit_segment(tcp_conn, segment); 318 /* 319 * We may not have been able to send data because the conn 320 * is getting stopped. libiscsi will know so propagate err 321 * for it to do the right thing. 322 */ 323 if (rc == -EAGAIN) 324 return rc; 325 else if (rc < 0) { 326 rc = ISCSI_ERR_XMIT_FAILED; 327 goto error; 328 } else if (rc == 0) 329 break; 330 331 consumed += rc; 332 333 if (segment->total_copied >= segment->total_size) { 334 if (segment->done != NULL) { 335 rc = segment->done(tcp_conn, segment); 336 if (rc != 0) 337 goto error; 338 } 339 } 340 } 341 342 ISCSI_SW_TCP_DBG(conn, "xmit %d bytes\n", consumed); 343 344 conn->txdata_octets += consumed; 345 return consumed; 346 347 error: 348 /* Transmit error. We could initiate error recovery 349 * here. */ 350 ISCSI_SW_TCP_DBG(conn, "Error sending PDU, errno=%d\n", rc); 351 iscsi_conn_failure(conn, rc); 352 return -EIO; 353 } 354 355 /** 356 * iscsi_tcp_xmit_qlen - return the number of bytes queued for xmit 357 * @conn: iscsi connection 358 */ 359 static inline int iscsi_sw_tcp_xmit_qlen(struct iscsi_conn *conn) 360 { 361 struct iscsi_tcp_conn *tcp_conn = conn->dd_data; 362 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; 363 struct iscsi_segment *segment = &tcp_sw_conn->out.segment; 364 365 return segment->total_copied - segment->total_size; 366 } 367 368 static int iscsi_sw_tcp_pdu_xmit(struct iscsi_task *task) 369 { 370 struct iscsi_conn *conn = task->conn; 371 unsigned int noreclaim_flag; 372 int rc = 0; 373 374 noreclaim_flag = memalloc_noreclaim_save(); 375 376 while (iscsi_sw_tcp_xmit_qlen(conn)) { 377 rc = iscsi_sw_tcp_xmit(conn); 378 if (rc == 0) { 379 rc = -EAGAIN; 380 break; 381 } 382 if (rc < 0) 383 break; 384 rc = 0; 385 } 386 387 memalloc_noreclaim_restore(noreclaim_flag); 388 return rc; 389 } 390 391 /* 392 * This is called when we're done sending the header. 393 * Simply copy the data_segment to the send segment, and return. 394 */ 395 static int iscsi_sw_tcp_send_hdr_done(struct iscsi_tcp_conn *tcp_conn, 396 struct iscsi_segment *segment) 397 { 398 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; 399 400 tcp_sw_conn->out.segment = tcp_sw_conn->out.data_segment; 401 ISCSI_SW_TCP_DBG(tcp_conn->iscsi_conn, 402 "Header done. Next segment size %u total_size %u\n", 403 tcp_sw_conn->out.segment.size, 404 tcp_sw_conn->out.segment.total_size); 405 return 0; 406 } 407 408 static void iscsi_sw_tcp_send_hdr_prep(struct iscsi_conn *conn, void *hdr, 409 size_t hdrlen) 410 { 411 struct iscsi_tcp_conn *tcp_conn = conn->dd_data; 412 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; 413 414 ISCSI_SW_TCP_DBG(conn, "%s\n", conn->hdrdgst_en ? 415 "digest enabled" : "digest disabled"); 416 417 /* Clear the data segment - needs to be filled in by the 418 * caller using iscsi_tcp_send_data_prep() */ 419 memset(&tcp_sw_conn->out.data_segment, 0, 420 sizeof(struct iscsi_segment)); 421 422 /* If header digest is enabled, compute the CRC and 423 * place the digest into the same buffer. We make 424 * sure that both iscsi_tcp_task and mtask have 425 * sufficient room. 426 */ 427 if (conn->hdrdgst_en) { 428 iscsi_tcp_dgst_header(tcp_sw_conn->tx_hash, hdr, hdrlen, 429 hdr + hdrlen); 430 hdrlen += ISCSI_DIGEST_SIZE; 431 } 432 433 /* Remember header pointer for later, when we need 434 * to decide whether there's a payload to go along 435 * with the header. */ 436 tcp_sw_conn->out.hdr = hdr; 437 438 iscsi_segment_init_linear(&tcp_sw_conn->out.segment, hdr, hdrlen, 439 iscsi_sw_tcp_send_hdr_done, NULL); 440 } 441 442 /* 443 * Prepare the send buffer for the payload data. 444 * Padding and checksumming will all be taken care 445 * of by the iscsi_segment routines. 446 */ 447 static int 448 iscsi_sw_tcp_send_data_prep(struct iscsi_conn *conn, struct scatterlist *sg, 449 unsigned int count, unsigned int offset, 450 unsigned int len) 451 { 452 struct iscsi_tcp_conn *tcp_conn = conn->dd_data; 453 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; 454 struct ahash_request *tx_hash = NULL; 455 unsigned int hdr_spec_len; 456 457 ISCSI_SW_TCP_DBG(conn, "offset=%d, datalen=%d %s\n", offset, len, 458 conn->datadgst_en ? 459 "digest enabled" : "digest disabled"); 460 461 /* Make sure the datalen matches what the caller 462 said he would send. */ 463 hdr_spec_len = ntoh24(tcp_sw_conn->out.hdr->dlength); 464 WARN_ON(iscsi_padded(len) != iscsi_padded(hdr_spec_len)); 465 466 if (conn->datadgst_en) 467 tx_hash = tcp_sw_conn->tx_hash; 468 469 return iscsi_segment_seek_sg(&tcp_sw_conn->out.data_segment, 470 sg, count, offset, len, 471 NULL, tx_hash); 472 } 473 474 static void 475 iscsi_sw_tcp_send_linear_data_prep(struct iscsi_conn *conn, void *data, 476 size_t len) 477 { 478 struct iscsi_tcp_conn *tcp_conn = conn->dd_data; 479 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; 480 struct ahash_request *tx_hash = NULL; 481 unsigned int hdr_spec_len; 482 483 ISCSI_SW_TCP_DBG(conn, "datalen=%zd %s\n", len, conn->datadgst_en ? 484 "digest enabled" : "digest disabled"); 485 486 /* Make sure the datalen matches what the caller 487 said he would send. */ 488 hdr_spec_len = ntoh24(tcp_sw_conn->out.hdr->dlength); 489 WARN_ON(iscsi_padded(len) != iscsi_padded(hdr_spec_len)); 490 491 if (conn->datadgst_en) 492 tx_hash = tcp_sw_conn->tx_hash; 493 494 iscsi_segment_init_linear(&tcp_sw_conn->out.data_segment, 495 data, len, NULL, tx_hash); 496 } 497 498 static int iscsi_sw_tcp_pdu_init(struct iscsi_task *task, 499 unsigned int offset, unsigned int count) 500 { 501 struct iscsi_conn *conn = task->conn; 502 int err = 0; 503 504 iscsi_sw_tcp_send_hdr_prep(conn, task->hdr, task->hdr_len); 505 506 if (!count) 507 return 0; 508 509 if (!task->sc) 510 iscsi_sw_tcp_send_linear_data_prep(conn, task->data, count); 511 else { 512 struct scsi_data_buffer *sdb = &task->sc->sdb; 513 514 err = iscsi_sw_tcp_send_data_prep(conn, sdb->table.sgl, 515 sdb->table.nents, offset, 516 count); 517 } 518 519 if (err) { 520 /* got invalid offset/len */ 521 return -EIO; 522 } 523 return 0; 524 } 525 526 static int iscsi_sw_tcp_pdu_alloc(struct iscsi_task *task, uint8_t opcode) 527 { 528 struct iscsi_tcp_task *tcp_task = task->dd_data; 529 530 task->hdr = task->dd_data + sizeof(*tcp_task); 531 task->hdr_max = sizeof(struct iscsi_sw_tcp_hdrbuf) - ISCSI_DIGEST_SIZE; 532 return 0; 533 } 534 535 static struct iscsi_cls_conn * 536 iscsi_sw_tcp_conn_create(struct iscsi_cls_session *cls_session, 537 uint32_t conn_idx) 538 { 539 struct iscsi_conn *conn; 540 struct iscsi_cls_conn *cls_conn; 541 struct iscsi_tcp_conn *tcp_conn; 542 struct iscsi_sw_tcp_conn *tcp_sw_conn; 543 struct crypto_ahash *tfm; 544 545 cls_conn = iscsi_tcp_conn_setup(cls_session, sizeof(*tcp_sw_conn), 546 conn_idx); 547 if (!cls_conn) 548 return NULL; 549 conn = cls_conn->dd_data; 550 tcp_conn = conn->dd_data; 551 tcp_sw_conn = tcp_conn->dd_data; 552 553 tfm = crypto_alloc_ahash("crc32c", 0, CRYPTO_ALG_ASYNC); 554 if (IS_ERR(tfm)) 555 goto free_conn; 556 557 tcp_sw_conn->tx_hash = ahash_request_alloc(tfm, GFP_KERNEL); 558 if (!tcp_sw_conn->tx_hash) 559 goto free_tfm; 560 ahash_request_set_callback(tcp_sw_conn->tx_hash, 0, NULL, NULL); 561 562 tcp_sw_conn->rx_hash = ahash_request_alloc(tfm, GFP_KERNEL); 563 if (!tcp_sw_conn->rx_hash) 564 goto free_tx_hash; 565 ahash_request_set_callback(tcp_sw_conn->rx_hash, 0, NULL, NULL); 566 567 tcp_conn->rx_hash = tcp_sw_conn->rx_hash; 568 569 return cls_conn; 570 571 free_tx_hash: 572 ahash_request_free(tcp_sw_conn->tx_hash); 573 free_tfm: 574 crypto_free_ahash(tfm); 575 free_conn: 576 iscsi_conn_printk(KERN_ERR, conn, 577 "Could not create connection due to crc32c " 578 "loading error. Make sure the crc32c " 579 "module is built as a module or into the " 580 "kernel\n"); 581 iscsi_tcp_conn_teardown(cls_conn); 582 return NULL; 583 } 584 585 static void iscsi_sw_tcp_release_conn(struct iscsi_conn *conn) 586 { 587 struct iscsi_session *session = conn->session; 588 struct iscsi_tcp_conn *tcp_conn = conn->dd_data; 589 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; 590 struct socket *sock = tcp_sw_conn->sock; 591 592 if (!sock) 593 return; 594 595 sock_hold(sock->sk); 596 iscsi_sw_tcp_conn_restore_callbacks(conn); 597 sock_put(sock->sk); 598 599 spin_lock_bh(&session->frwd_lock); 600 tcp_sw_conn->sock = NULL; 601 spin_unlock_bh(&session->frwd_lock); 602 sockfd_put(sock); 603 } 604 605 static void iscsi_sw_tcp_conn_destroy(struct iscsi_cls_conn *cls_conn) 606 { 607 struct iscsi_conn *conn = cls_conn->dd_data; 608 struct iscsi_tcp_conn *tcp_conn = conn->dd_data; 609 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; 610 611 iscsi_sw_tcp_release_conn(conn); 612 613 ahash_request_free(tcp_sw_conn->rx_hash); 614 if (tcp_sw_conn->tx_hash) { 615 struct crypto_ahash *tfm; 616 617 tfm = crypto_ahash_reqtfm(tcp_sw_conn->tx_hash); 618 ahash_request_free(tcp_sw_conn->tx_hash); 619 crypto_free_ahash(tfm); 620 } 621 622 iscsi_tcp_conn_teardown(cls_conn); 623 } 624 625 static void iscsi_sw_tcp_conn_stop(struct iscsi_cls_conn *cls_conn, int flag) 626 { 627 struct iscsi_conn *conn = cls_conn->dd_data; 628 struct iscsi_tcp_conn *tcp_conn = conn->dd_data; 629 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; 630 struct socket *sock = tcp_sw_conn->sock; 631 632 /* userspace may have goofed up and not bound us */ 633 if (!sock) 634 return; 635 636 sock->sk->sk_err = EIO; 637 wake_up_interruptible(sk_sleep(sock->sk)); 638 639 /* stop xmit side */ 640 iscsi_suspend_tx(conn); 641 642 /* stop recv side and release socket */ 643 iscsi_sw_tcp_release_conn(conn); 644 645 iscsi_conn_stop(cls_conn, flag); 646 } 647 648 static int 649 iscsi_sw_tcp_conn_bind(struct iscsi_cls_session *cls_session, 650 struct iscsi_cls_conn *cls_conn, uint64_t transport_eph, 651 int is_leading) 652 { 653 struct iscsi_session *session = cls_session->dd_data; 654 struct iscsi_conn *conn = cls_conn->dd_data; 655 struct iscsi_tcp_conn *tcp_conn = conn->dd_data; 656 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; 657 struct sock *sk; 658 struct socket *sock; 659 int err; 660 661 /* lookup for existing socket */ 662 sock = sockfd_lookup((int)transport_eph, &err); 663 if (!sock) { 664 iscsi_conn_printk(KERN_ERR, conn, 665 "sockfd_lookup failed %d\n", err); 666 return -EEXIST; 667 } 668 669 err = iscsi_conn_bind(cls_session, cls_conn, is_leading); 670 if (err) 671 goto free_socket; 672 673 spin_lock_bh(&session->frwd_lock); 674 /* bind iSCSI connection and socket */ 675 tcp_sw_conn->sock = sock; 676 spin_unlock_bh(&session->frwd_lock); 677 678 /* setup Socket parameters */ 679 sk = sock->sk; 680 sk->sk_reuse = SK_CAN_REUSE; 681 sk->sk_sndtimeo = 15 * HZ; /* FIXME: make it configurable */ 682 sk->sk_allocation = GFP_ATOMIC; 683 sk_set_memalloc(sk); 684 685 iscsi_sw_tcp_conn_set_callbacks(conn); 686 tcp_sw_conn->sendpage = tcp_sw_conn->sock->ops->sendpage; 687 /* 688 * set receive state machine into initial state 689 */ 690 iscsi_tcp_hdr_recv_prep(tcp_conn); 691 return 0; 692 693 free_socket: 694 sockfd_put(sock); 695 return err; 696 } 697 698 static int iscsi_sw_tcp_conn_set_param(struct iscsi_cls_conn *cls_conn, 699 enum iscsi_param param, char *buf, 700 int buflen) 701 { 702 struct iscsi_conn *conn = cls_conn->dd_data; 703 struct iscsi_tcp_conn *tcp_conn = conn->dd_data; 704 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; 705 706 switch(param) { 707 case ISCSI_PARAM_HDRDGST_EN: 708 iscsi_set_param(cls_conn, param, buf, buflen); 709 break; 710 case ISCSI_PARAM_DATADGST_EN: 711 iscsi_set_param(cls_conn, param, buf, buflen); 712 tcp_sw_conn->sendpage = conn->datadgst_en ? 713 sock_no_sendpage : tcp_sw_conn->sock->ops->sendpage; 714 break; 715 case ISCSI_PARAM_MAX_R2T: 716 return iscsi_tcp_set_max_r2t(conn, buf); 717 default: 718 return iscsi_set_param(cls_conn, param, buf, buflen); 719 } 720 721 return 0; 722 } 723 724 static int iscsi_sw_tcp_conn_get_param(struct iscsi_cls_conn *cls_conn, 725 enum iscsi_param param, char *buf) 726 { 727 struct iscsi_conn *conn = cls_conn->dd_data; 728 struct iscsi_tcp_conn *tcp_conn = conn->dd_data; 729 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; 730 struct sockaddr_in6 addr; 731 int rc; 732 733 switch(param) { 734 case ISCSI_PARAM_CONN_PORT: 735 case ISCSI_PARAM_CONN_ADDRESS: 736 case ISCSI_PARAM_LOCAL_PORT: 737 spin_lock_bh(&conn->session->frwd_lock); 738 if (!tcp_sw_conn || !tcp_sw_conn->sock) { 739 spin_unlock_bh(&conn->session->frwd_lock); 740 return -ENOTCONN; 741 } 742 if (param == ISCSI_PARAM_LOCAL_PORT) 743 rc = kernel_getsockname(tcp_sw_conn->sock, 744 (struct sockaddr *)&addr); 745 else 746 rc = kernel_getpeername(tcp_sw_conn->sock, 747 (struct sockaddr *)&addr); 748 spin_unlock_bh(&conn->session->frwd_lock); 749 if (rc < 0) 750 return rc; 751 752 return iscsi_conn_get_addr_param((struct sockaddr_storage *) 753 &addr, param, buf); 754 default: 755 return iscsi_conn_get_param(cls_conn, param, buf); 756 } 757 758 return 0; 759 } 760 761 static int iscsi_sw_tcp_host_get_param(struct Scsi_Host *shost, 762 enum iscsi_host_param param, char *buf) 763 { 764 struct iscsi_sw_tcp_host *tcp_sw_host = iscsi_host_priv(shost); 765 struct iscsi_session *session = tcp_sw_host->session; 766 struct iscsi_conn *conn; 767 struct iscsi_tcp_conn *tcp_conn; 768 struct iscsi_sw_tcp_conn *tcp_sw_conn; 769 struct sockaddr_in6 addr; 770 int rc; 771 772 switch (param) { 773 case ISCSI_HOST_PARAM_IPADDRESS: 774 if (!session) 775 return -ENOTCONN; 776 777 spin_lock_bh(&session->frwd_lock); 778 conn = session->leadconn; 779 if (!conn) { 780 spin_unlock_bh(&session->frwd_lock); 781 return -ENOTCONN; 782 } 783 tcp_conn = conn->dd_data; 784 785 tcp_sw_conn = tcp_conn->dd_data; 786 if (!tcp_sw_conn->sock) { 787 spin_unlock_bh(&session->frwd_lock); 788 return -ENOTCONN; 789 } 790 791 rc = kernel_getsockname(tcp_sw_conn->sock, 792 (struct sockaddr *)&addr); 793 spin_unlock_bh(&session->frwd_lock); 794 if (rc < 0) 795 return rc; 796 797 return iscsi_conn_get_addr_param((struct sockaddr_storage *) 798 &addr, 799 (enum iscsi_param)param, buf); 800 default: 801 return iscsi_host_get_param(shost, param, buf); 802 } 803 804 return 0; 805 } 806 807 static void 808 iscsi_sw_tcp_conn_get_stats(struct iscsi_cls_conn *cls_conn, 809 struct iscsi_stats *stats) 810 { 811 struct iscsi_conn *conn = cls_conn->dd_data; 812 struct iscsi_tcp_conn *tcp_conn = conn->dd_data; 813 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; 814 815 stats->custom_length = 3; 816 strcpy(stats->custom[0].desc, "tx_sendpage_failures"); 817 stats->custom[0].value = tcp_sw_conn->sendpage_failures_cnt; 818 strcpy(stats->custom[1].desc, "rx_discontiguous_hdr"); 819 stats->custom[1].value = tcp_sw_conn->discontiguous_hdr_cnt; 820 strcpy(stats->custom[2].desc, "eh_abort_cnt"); 821 stats->custom[2].value = conn->eh_abort_cnt; 822 823 iscsi_tcp_conn_get_stats(cls_conn, stats); 824 } 825 826 static struct iscsi_cls_session * 827 iscsi_sw_tcp_session_create(struct iscsi_endpoint *ep, uint16_t cmds_max, 828 uint16_t qdepth, uint32_t initial_cmdsn) 829 { 830 struct iscsi_cls_session *cls_session; 831 struct iscsi_session *session; 832 struct iscsi_sw_tcp_host *tcp_sw_host; 833 struct Scsi_Host *shost; 834 835 if (ep) { 836 printk(KERN_ERR "iscsi_tcp: invalid ep %p.\n", ep); 837 return NULL; 838 } 839 840 shost = iscsi_host_alloc(&iscsi_sw_tcp_sht, 841 sizeof(struct iscsi_sw_tcp_host), 1); 842 if (!shost) 843 return NULL; 844 shost->transportt = iscsi_sw_tcp_scsi_transport; 845 shost->cmd_per_lun = qdepth; 846 shost->max_lun = iscsi_max_lun; 847 shost->max_id = 0; 848 shost->max_channel = 0; 849 shost->max_cmd_len = SCSI_MAX_VARLEN_CDB_SIZE; 850 851 if (iscsi_host_add(shost, NULL)) 852 goto free_host; 853 854 cls_session = iscsi_session_setup(&iscsi_sw_tcp_transport, shost, 855 cmds_max, 0, 856 sizeof(struct iscsi_tcp_task) + 857 sizeof(struct iscsi_sw_tcp_hdrbuf), 858 initial_cmdsn, 0); 859 if (!cls_session) 860 goto remove_host; 861 session = cls_session->dd_data; 862 tcp_sw_host = iscsi_host_priv(shost); 863 tcp_sw_host->session = session; 864 865 shost->can_queue = session->scsi_cmds_max; 866 if (iscsi_tcp_r2tpool_alloc(session)) 867 goto remove_session; 868 return cls_session; 869 870 remove_session: 871 iscsi_session_teardown(cls_session); 872 remove_host: 873 iscsi_host_remove(shost); 874 free_host: 875 iscsi_host_free(shost); 876 return NULL; 877 } 878 879 static void iscsi_sw_tcp_session_destroy(struct iscsi_cls_session *cls_session) 880 { 881 struct Scsi_Host *shost = iscsi_session_to_shost(cls_session); 882 883 iscsi_tcp_r2tpool_free(cls_session->dd_data); 884 iscsi_session_teardown(cls_session); 885 886 iscsi_host_remove(shost); 887 iscsi_host_free(shost); 888 } 889 890 static umode_t iscsi_sw_tcp_attr_is_visible(int param_type, int param) 891 { 892 switch (param_type) { 893 case ISCSI_HOST_PARAM: 894 switch (param) { 895 case ISCSI_HOST_PARAM_NETDEV_NAME: 896 case ISCSI_HOST_PARAM_HWADDRESS: 897 case ISCSI_HOST_PARAM_IPADDRESS: 898 case ISCSI_HOST_PARAM_INITIATOR_NAME: 899 return S_IRUGO; 900 default: 901 return 0; 902 } 903 case ISCSI_PARAM: 904 switch (param) { 905 case ISCSI_PARAM_MAX_RECV_DLENGTH: 906 case ISCSI_PARAM_MAX_XMIT_DLENGTH: 907 case ISCSI_PARAM_HDRDGST_EN: 908 case ISCSI_PARAM_DATADGST_EN: 909 case ISCSI_PARAM_CONN_ADDRESS: 910 case ISCSI_PARAM_CONN_PORT: 911 case ISCSI_PARAM_LOCAL_PORT: 912 case ISCSI_PARAM_EXP_STATSN: 913 case ISCSI_PARAM_PERSISTENT_ADDRESS: 914 case ISCSI_PARAM_PERSISTENT_PORT: 915 case ISCSI_PARAM_PING_TMO: 916 case ISCSI_PARAM_RECV_TMO: 917 case ISCSI_PARAM_INITIAL_R2T_EN: 918 case ISCSI_PARAM_MAX_R2T: 919 case ISCSI_PARAM_IMM_DATA_EN: 920 case ISCSI_PARAM_FIRST_BURST: 921 case ISCSI_PARAM_MAX_BURST: 922 case ISCSI_PARAM_PDU_INORDER_EN: 923 case ISCSI_PARAM_DATASEQ_INORDER_EN: 924 case ISCSI_PARAM_ERL: 925 case ISCSI_PARAM_TARGET_NAME: 926 case ISCSI_PARAM_TPGT: 927 case ISCSI_PARAM_USERNAME: 928 case ISCSI_PARAM_PASSWORD: 929 case ISCSI_PARAM_USERNAME_IN: 930 case ISCSI_PARAM_PASSWORD_IN: 931 case ISCSI_PARAM_FAST_ABORT: 932 case ISCSI_PARAM_ABORT_TMO: 933 case ISCSI_PARAM_LU_RESET_TMO: 934 case ISCSI_PARAM_TGT_RESET_TMO: 935 case ISCSI_PARAM_IFACE_NAME: 936 case ISCSI_PARAM_INITIATOR_NAME: 937 return S_IRUGO; 938 default: 939 return 0; 940 } 941 } 942 943 return 0; 944 } 945 946 static int iscsi_sw_tcp_slave_configure(struct scsi_device *sdev) 947 { 948 struct iscsi_sw_tcp_host *tcp_sw_host = iscsi_host_priv(sdev->host); 949 struct iscsi_session *session = tcp_sw_host->session; 950 struct iscsi_conn *conn = session->leadconn; 951 952 if (conn->datadgst_en) 953 sdev->request_queue->backing_dev_info->capabilities 954 |= BDI_CAP_STABLE_WRITES; 955 blk_queue_dma_alignment(sdev->request_queue, 0); 956 return 0; 957 } 958 959 static struct scsi_host_template iscsi_sw_tcp_sht = { 960 .module = THIS_MODULE, 961 .name = "iSCSI Initiator over TCP/IP", 962 .queuecommand = iscsi_queuecommand, 963 .change_queue_depth = scsi_change_queue_depth, 964 .can_queue = ISCSI_DEF_XMIT_CMDS_MAX - 1, 965 .sg_tablesize = 4096, 966 .max_sectors = 0xFFFF, 967 .cmd_per_lun = ISCSI_DEF_CMD_PER_LUN, 968 .eh_timed_out = iscsi_eh_cmd_timed_out, 969 .eh_abort_handler = iscsi_eh_abort, 970 .eh_device_reset_handler= iscsi_eh_device_reset, 971 .eh_target_reset_handler = iscsi_eh_recover_target, 972 .dma_boundary = PAGE_SIZE - 1, 973 .slave_configure = iscsi_sw_tcp_slave_configure, 974 .target_alloc = iscsi_target_alloc, 975 .proc_name = "iscsi_tcp", 976 .this_id = -1, 977 .track_queue_depth = 1, 978 }; 979 980 static struct iscsi_transport iscsi_sw_tcp_transport = { 981 .owner = THIS_MODULE, 982 .name = "tcp", 983 .caps = CAP_RECOVERY_L0 | CAP_MULTI_R2T | CAP_HDRDGST 984 | CAP_DATADGST, 985 /* session management */ 986 .create_session = iscsi_sw_tcp_session_create, 987 .destroy_session = iscsi_sw_tcp_session_destroy, 988 /* connection management */ 989 .create_conn = iscsi_sw_tcp_conn_create, 990 .bind_conn = iscsi_sw_tcp_conn_bind, 991 .destroy_conn = iscsi_sw_tcp_conn_destroy, 992 .attr_is_visible = iscsi_sw_tcp_attr_is_visible, 993 .set_param = iscsi_sw_tcp_conn_set_param, 994 .get_conn_param = iscsi_sw_tcp_conn_get_param, 995 .get_session_param = iscsi_session_get_param, 996 .start_conn = iscsi_conn_start, 997 .stop_conn = iscsi_sw_tcp_conn_stop, 998 /* iscsi host params */ 999 .get_host_param = iscsi_sw_tcp_host_get_param, 1000 .set_host_param = iscsi_host_set_param, 1001 /* IO */ 1002 .send_pdu = iscsi_conn_send_pdu, 1003 .get_stats = iscsi_sw_tcp_conn_get_stats, 1004 /* iscsi task/cmd helpers */ 1005 .init_task = iscsi_tcp_task_init, 1006 .xmit_task = iscsi_tcp_task_xmit, 1007 .cleanup_task = iscsi_tcp_cleanup_task, 1008 /* low level pdu helpers */ 1009 .xmit_pdu = iscsi_sw_tcp_pdu_xmit, 1010 .init_pdu = iscsi_sw_tcp_pdu_init, 1011 .alloc_pdu = iscsi_sw_tcp_pdu_alloc, 1012 /* recovery */ 1013 .session_recovery_timedout = iscsi_session_recovery_timedout, 1014 }; 1015 1016 static int __init iscsi_sw_tcp_init(void) 1017 { 1018 if (iscsi_max_lun < 1) { 1019 printk(KERN_ERR "iscsi_tcp: Invalid max_lun value of %u\n", 1020 iscsi_max_lun); 1021 return -EINVAL; 1022 } 1023 1024 iscsi_sw_tcp_scsi_transport = iscsi_register_transport( 1025 &iscsi_sw_tcp_transport); 1026 if (!iscsi_sw_tcp_scsi_transport) 1027 return -ENODEV; 1028 1029 return 0; 1030 } 1031 1032 static void __exit iscsi_sw_tcp_exit(void) 1033 { 1034 iscsi_unregister_transport(&iscsi_sw_tcp_transport); 1035 } 1036 1037 module_init(iscsi_sw_tcp_init); 1038 module_exit(iscsi_sw_tcp_exit); 1039