1 /* 2 * iSCSI Initiator over TCP/IP Data-Path 3 * 4 * Copyright (C) 2004 Dmitry Yusupov 5 * Copyright (C) 2004 Alex Aizman 6 * Copyright (C) 2005 - 2006 Mike Christie 7 * Copyright (C) 2006 Red Hat, Inc. All rights reserved. 8 * maintained by open-iscsi@googlegroups.com 9 * 10 * This program is free software; you can redistribute it and/or modify 11 * it under the terms of the GNU General Public License as published 12 * by the Free Software Foundation; either version 2 of the License, or 13 * (at your option) any later version. 14 * 15 * This program is distributed in the hope that it will be useful, but 16 * WITHOUT ANY WARRANTY; without even the implied warranty of 17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 18 * General Public License for more details. 19 * 20 * See the file COPYING included with this distribution for more details. 21 * 22 * Credits: 23 * Christoph Hellwig 24 * FUJITA Tomonori 25 * Arne Redlich 26 * Zhenyu Wang 27 */ 28 29 #include <crypto/hash.h> 30 #include <linux/types.h> 31 #include <linux/inet.h> 32 #include <linux/slab.h> 33 #include <linux/sched/mm.h> 34 #include <linux/file.h> 35 #include <linux/blkdev.h> 36 #include <linux/delay.h> 37 #include <linux/kfifo.h> 38 #include <linux/scatterlist.h> 39 #include <linux/module.h> 40 #include <linux/backing-dev.h> 41 #include <net/tcp.h> 42 #include <scsi/scsi_cmnd.h> 43 #include <scsi/scsi_device.h> 44 #include <scsi/scsi_host.h> 45 #include <scsi/scsi.h> 46 #include <scsi/scsi_transport_iscsi.h> 47 #include <trace/events/iscsi.h> 48 49 #include "iscsi_tcp.h" 50 51 MODULE_AUTHOR("Mike Christie <michaelc@cs.wisc.edu>, " 52 "Dmitry Yusupov <dmitry_yus@yahoo.com>, " 53 "Alex Aizman <itn780@yahoo.com>"); 54 MODULE_DESCRIPTION("iSCSI/TCP data-path"); 55 MODULE_LICENSE("GPL"); 56 57 static struct scsi_transport_template *iscsi_sw_tcp_scsi_transport; 58 static struct scsi_host_template iscsi_sw_tcp_sht; 59 static struct iscsi_transport iscsi_sw_tcp_transport; 60 61 static unsigned int iscsi_max_lun = ~0; 62 module_param_named(max_lun, iscsi_max_lun, uint, S_IRUGO); 63 64 static int iscsi_sw_tcp_dbg; 65 module_param_named(debug_iscsi_tcp, iscsi_sw_tcp_dbg, int, 66 S_IRUGO | S_IWUSR); 67 MODULE_PARM_DESC(debug_iscsi_tcp, "Turn on debugging for iscsi_tcp module " 68 "Set to 1 to turn on, and zero to turn off. Default is off."); 69 70 #define ISCSI_SW_TCP_DBG(_conn, dbg_fmt, arg...) \ 71 do { \ 72 if (iscsi_sw_tcp_dbg) \ 73 iscsi_conn_printk(KERN_INFO, _conn, \ 74 "%s " dbg_fmt, \ 75 __func__, ##arg); \ 76 iscsi_dbg_trace(trace_iscsi_dbg_sw_tcp, \ 77 &(_conn)->cls_conn->dev, \ 78 "%s " dbg_fmt, __func__, ##arg);\ 79 } while (0); 80 81 82 /** 83 * iscsi_sw_tcp_recv - TCP receive in sendfile fashion 84 * @rd_desc: read descriptor 85 * @skb: socket buffer 86 * @offset: offset in skb 87 * @len: skb->len - offset 88 */ 89 static int iscsi_sw_tcp_recv(read_descriptor_t *rd_desc, struct sk_buff *skb, 90 unsigned int offset, size_t len) 91 { 92 struct iscsi_conn *conn = rd_desc->arg.data; 93 unsigned int consumed, total_consumed = 0; 94 int status; 95 96 ISCSI_SW_TCP_DBG(conn, "in %d bytes\n", skb->len - offset); 97 98 do { 99 status = 0; 100 consumed = iscsi_tcp_recv_skb(conn, skb, offset, 0, &status); 101 offset += consumed; 102 total_consumed += consumed; 103 } while (consumed != 0 && status != ISCSI_TCP_SKB_DONE); 104 105 ISCSI_SW_TCP_DBG(conn, "read %d bytes status %d\n", 106 skb->len - offset, status); 107 return total_consumed; 108 } 109 110 /** 111 * iscsi_sw_sk_state_check - check socket state 112 * @sk: socket 113 * 114 * If the socket is in CLOSE or CLOSE_WAIT we should 115 * not close the connection if there is still some 116 * data pending. 117 * 118 * Must be called with sk_callback_lock. 119 */ 120 static inline int iscsi_sw_sk_state_check(struct sock *sk) 121 { 122 struct iscsi_conn *conn = sk->sk_user_data; 123 124 if ((sk->sk_state == TCP_CLOSE_WAIT || sk->sk_state == TCP_CLOSE) && 125 (conn->session->state != ISCSI_STATE_LOGGING_OUT) && 126 !atomic_read(&sk->sk_rmem_alloc)) { 127 ISCSI_SW_TCP_DBG(conn, "TCP_CLOSE|TCP_CLOSE_WAIT\n"); 128 iscsi_conn_failure(conn, ISCSI_ERR_TCP_CONN_CLOSE); 129 return -ECONNRESET; 130 } 131 return 0; 132 } 133 134 static void iscsi_sw_tcp_data_ready(struct sock *sk) 135 { 136 struct iscsi_conn *conn; 137 struct iscsi_tcp_conn *tcp_conn; 138 read_descriptor_t rd_desc; 139 140 read_lock_bh(&sk->sk_callback_lock); 141 conn = sk->sk_user_data; 142 if (!conn) { 143 read_unlock_bh(&sk->sk_callback_lock); 144 return; 145 } 146 tcp_conn = conn->dd_data; 147 148 /* 149 * Use rd_desc to pass 'conn' to iscsi_tcp_recv. 150 * We set count to 1 because we want the network layer to 151 * hand us all the skbs that are available. iscsi_tcp_recv 152 * handled pdus that cross buffers or pdus that still need data. 153 */ 154 rd_desc.arg.data = conn; 155 rd_desc.count = 1; 156 tcp_read_sock(sk, &rd_desc, iscsi_sw_tcp_recv); 157 158 iscsi_sw_sk_state_check(sk); 159 160 /* If we had to (atomically) map a highmem page, 161 * unmap it now. */ 162 iscsi_tcp_segment_unmap(&tcp_conn->in.segment); 163 read_unlock_bh(&sk->sk_callback_lock); 164 } 165 166 static void iscsi_sw_tcp_state_change(struct sock *sk) 167 { 168 struct iscsi_tcp_conn *tcp_conn; 169 struct iscsi_sw_tcp_conn *tcp_sw_conn; 170 struct iscsi_conn *conn; 171 void (*old_state_change)(struct sock *); 172 173 read_lock_bh(&sk->sk_callback_lock); 174 conn = sk->sk_user_data; 175 if (!conn) { 176 read_unlock_bh(&sk->sk_callback_lock); 177 return; 178 } 179 180 iscsi_sw_sk_state_check(sk); 181 182 tcp_conn = conn->dd_data; 183 tcp_sw_conn = tcp_conn->dd_data; 184 old_state_change = tcp_sw_conn->old_state_change; 185 186 read_unlock_bh(&sk->sk_callback_lock); 187 188 old_state_change(sk); 189 } 190 191 /** 192 * iscsi_write_space - Called when more output buffer space is available 193 * @sk: socket space is available for 194 **/ 195 static void iscsi_sw_tcp_write_space(struct sock *sk) 196 { 197 struct iscsi_conn *conn; 198 struct iscsi_tcp_conn *tcp_conn; 199 struct iscsi_sw_tcp_conn *tcp_sw_conn; 200 void (*old_write_space)(struct sock *); 201 202 read_lock_bh(&sk->sk_callback_lock); 203 conn = sk->sk_user_data; 204 if (!conn) { 205 read_unlock_bh(&sk->sk_callback_lock); 206 return; 207 } 208 209 tcp_conn = conn->dd_data; 210 tcp_sw_conn = tcp_conn->dd_data; 211 old_write_space = tcp_sw_conn->old_write_space; 212 read_unlock_bh(&sk->sk_callback_lock); 213 214 old_write_space(sk); 215 216 ISCSI_SW_TCP_DBG(conn, "iscsi_write_space\n"); 217 iscsi_conn_queue_work(conn); 218 } 219 220 static void iscsi_sw_tcp_conn_set_callbacks(struct iscsi_conn *conn) 221 { 222 struct iscsi_tcp_conn *tcp_conn = conn->dd_data; 223 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; 224 struct sock *sk = tcp_sw_conn->sock->sk; 225 226 /* assign new callbacks */ 227 write_lock_bh(&sk->sk_callback_lock); 228 sk->sk_user_data = conn; 229 tcp_sw_conn->old_data_ready = sk->sk_data_ready; 230 tcp_sw_conn->old_state_change = sk->sk_state_change; 231 tcp_sw_conn->old_write_space = sk->sk_write_space; 232 sk->sk_data_ready = iscsi_sw_tcp_data_ready; 233 sk->sk_state_change = iscsi_sw_tcp_state_change; 234 sk->sk_write_space = iscsi_sw_tcp_write_space; 235 write_unlock_bh(&sk->sk_callback_lock); 236 } 237 238 static void 239 iscsi_sw_tcp_conn_restore_callbacks(struct iscsi_conn *conn) 240 { 241 struct iscsi_tcp_conn *tcp_conn = conn->dd_data; 242 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; 243 struct sock *sk = tcp_sw_conn->sock->sk; 244 245 /* restore socket callbacks, see also: iscsi_conn_set_callbacks() */ 246 write_lock_bh(&sk->sk_callback_lock); 247 sk->sk_user_data = NULL; 248 sk->sk_data_ready = tcp_sw_conn->old_data_ready; 249 sk->sk_state_change = tcp_sw_conn->old_state_change; 250 sk->sk_write_space = tcp_sw_conn->old_write_space; 251 sk->sk_no_check_tx = 0; 252 write_unlock_bh(&sk->sk_callback_lock); 253 } 254 255 /** 256 * iscsi_sw_tcp_xmit_segment - transmit segment 257 * @tcp_conn: the iSCSI TCP connection 258 * @segment: the buffer to transmnit 259 * 260 * This function transmits as much of the buffer as 261 * the network layer will accept, and returns the number of 262 * bytes transmitted. 263 * 264 * If CRC hashing is enabled, the function will compute the 265 * hash as it goes. When the entire segment has been transmitted, 266 * it will retrieve the hash value and send it as well. 267 */ 268 static int iscsi_sw_tcp_xmit_segment(struct iscsi_tcp_conn *tcp_conn, 269 struct iscsi_segment *segment) 270 { 271 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; 272 struct socket *sk = tcp_sw_conn->sock; 273 unsigned int copied = 0; 274 int r = 0; 275 276 while (!iscsi_tcp_segment_done(tcp_conn, segment, 0, r)) { 277 struct scatterlist *sg; 278 unsigned int offset, copy; 279 int flags = 0; 280 281 r = 0; 282 offset = segment->copied; 283 copy = segment->size - offset; 284 285 if (segment->total_copied + segment->size < segment->total_size) 286 flags |= MSG_MORE; 287 288 /* Use sendpage if we can; else fall back to sendmsg */ 289 if (!segment->data) { 290 sg = segment->sg; 291 offset += segment->sg_offset + sg->offset; 292 r = tcp_sw_conn->sendpage(sk, sg_page(sg), offset, 293 copy, flags); 294 } else { 295 struct msghdr msg = { .msg_flags = flags }; 296 struct kvec iov = { 297 .iov_base = segment->data + offset, 298 .iov_len = copy 299 }; 300 301 r = kernel_sendmsg(sk, &msg, &iov, 1, copy); 302 } 303 304 if (r < 0) { 305 iscsi_tcp_segment_unmap(segment); 306 return r; 307 } 308 copied += r; 309 } 310 return copied; 311 } 312 313 /** 314 * iscsi_sw_tcp_xmit - TCP transmit 315 * @conn: iscsi connection 316 **/ 317 static int iscsi_sw_tcp_xmit(struct iscsi_conn *conn) 318 { 319 struct iscsi_tcp_conn *tcp_conn = conn->dd_data; 320 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; 321 struct iscsi_segment *segment = &tcp_sw_conn->out.segment; 322 unsigned int consumed = 0; 323 int rc = 0; 324 325 while (1) { 326 rc = iscsi_sw_tcp_xmit_segment(tcp_conn, segment); 327 /* 328 * We may not have been able to send data because the conn 329 * is getting stopped. libiscsi will know so propagate err 330 * for it to do the right thing. 331 */ 332 if (rc == -EAGAIN) 333 return rc; 334 else if (rc < 0) { 335 rc = ISCSI_ERR_XMIT_FAILED; 336 goto error; 337 } else if (rc == 0) 338 break; 339 340 consumed += rc; 341 342 if (segment->total_copied >= segment->total_size) { 343 if (segment->done != NULL) { 344 rc = segment->done(tcp_conn, segment); 345 if (rc != 0) 346 goto error; 347 } 348 } 349 } 350 351 ISCSI_SW_TCP_DBG(conn, "xmit %d bytes\n", consumed); 352 353 conn->txdata_octets += consumed; 354 return consumed; 355 356 error: 357 /* Transmit error. We could initiate error recovery 358 * here. */ 359 ISCSI_SW_TCP_DBG(conn, "Error sending PDU, errno=%d\n", rc); 360 iscsi_conn_failure(conn, rc); 361 return -EIO; 362 } 363 364 /** 365 * iscsi_tcp_xmit_qlen - return the number of bytes queued for xmit 366 * @conn: iscsi connection 367 */ 368 static inline int iscsi_sw_tcp_xmit_qlen(struct iscsi_conn *conn) 369 { 370 struct iscsi_tcp_conn *tcp_conn = conn->dd_data; 371 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; 372 struct iscsi_segment *segment = &tcp_sw_conn->out.segment; 373 374 return segment->total_copied - segment->total_size; 375 } 376 377 static int iscsi_sw_tcp_pdu_xmit(struct iscsi_task *task) 378 { 379 struct iscsi_conn *conn = task->conn; 380 unsigned int noreclaim_flag; 381 int rc = 0; 382 383 noreclaim_flag = memalloc_noreclaim_save(); 384 385 while (iscsi_sw_tcp_xmit_qlen(conn)) { 386 rc = iscsi_sw_tcp_xmit(conn); 387 if (rc == 0) { 388 rc = -EAGAIN; 389 break; 390 } 391 if (rc < 0) 392 break; 393 rc = 0; 394 } 395 396 memalloc_noreclaim_restore(noreclaim_flag); 397 return rc; 398 } 399 400 /* 401 * This is called when we're done sending the header. 402 * Simply copy the data_segment to the send segment, and return. 403 */ 404 static int iscsi_sw_tcp_send_hdr_done(struct iscsi_tcp_conn *tcp_conn, 405 struct iscsi_segment *segment) 406 { 407 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; 408 409 tcp_sw_conn->out.segment = tcp_sw_conn->out.data_segment; 410 ISCSI_SW_TCP_DBG(tcp_conn->iscsi_conn, 411 "Header done. Next segment size %u total_size %u\n", 412 tcp_sw_conn->out.segment.size, 413 tcp_sw_conn->out.segment.total_size); 414 return 0; 415 } 416 417 static void iscsi_sw_tcp_send_hdr_prep(struct iscsi_conn *conn, void *hdr, 418 size_t hdrlen) 419 { 420 struct iscsi_tcp_conn *tcp_conn = conn->dd_data; 421 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; 422 423 ISCSI_SW_TCP_DBG(conn, "%s\n", conn->hdrdgst_en ? 424 "digest enabled" : "digest disabled"); 425 426 /* Clear the data segment - needs to be filled in by the 427 * caller using iscsi_tcp_send_data_prep() */ 428 memset(&tcp_sw_conn->out.data_segment, 0, 429 sizeof(struct iscsi_segment)); 430 431 /* If header digest is enabled, compute the CRC and 432 * place the digest into the same buffer. We make 433 * sure that both iscsi_tcp_task and mtask have 434 * sufficient room. 435 */ 436 if (conn->hdrdgst_en) { 437 iscsi_tcp_dgst_header(tcp_sw_conn->tx_hash, hdr, hdrlen, 438 hdr + hdrlen); 439 hdrlen += ISCSI_DIGEST_SIZE; 440 } 441 442 /* Remember header pointer for later, when we need 443 * to decide whether there's a payload to go along 444 * with the header. */ 445 tcp_sw_conn->out.hdr = hdr; 446 447 iscsi_segment_init_linear(&tcp_sw_conn->out.segment, hdr, hdrlen, 448 iscsi_sw_tcp_send_hdr_done, NULL); 449 } 450 451 /* 452 * Prepare the send buffer for the payload data. 453 * Padding and checksumming will all be taken care 454 * of by the iscsi_segment routines. 455 */ 456 static int 457 iscsi_sw_tcp_send_data_prep(struct iscsi_conn *conn, struct scatterlist *sg, 458 unsigned int count, unsigned int offset, 459 unsigned int len) 460 { 461 struct iscsi_tcp_conn *tcp_conn = conn->dd_data; 462 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; 463 struct ahash_request *tx_hash = NULL; 464 unsigned int hdr_spec_len; 465 466 ISCSI_SW_TCP_DBG(conn, "offset=%d, datalen=%d %s\n", offset, len, 467 conn->datadgst_en ? 468 "digest enabled" : "digest disabled"); 469 470 /* Make sure the datalen matches what the caller 471 said he would send. */ 472 hdr_spec_len = ntoh24(tcp_sw_conn->out.hdr->dlength); 473 WARN_ON(iscsi_padded(len) != iscsi_padded(hdr_spec_len)); 474 475 if (conn->datadgst_en) 476 tx_hash = tcp_sw_conn->tx_hash; 477 478 return iscsi_segment_seek_sg(&tcp_sw_conn->out.data_segment, 479 sg, count, offset, len, 480 NULL, tx_hash); 481 } 482 483 static void 484 iscsi_sw_tcp_send_linear_data_prep(struct iscsi_conn *conn, void *data, 485 size_t len) 486 { 487 struct iscsi_tcp_conn *tcp_conn = conn->dd_data; 488 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; 489 struct ahash_request *tx_hash = NULL; 490 unsigned int hdr_spec_len; 491 492 ISCSI_SW_TCP_DBG(conn, "datalen=%zd %s\n", len, conn->datadgst_en ? 493 "digest enabled" : "digest disabled"); 494 495 /* Make sure the datalen matches what the caller 496 said he would send. */ 497 hdr_spec_len = ntoh24(tcp_sw_conn->out.hdr->dlength); 498 WARN_ON(iscsi_padded(len) != iscsi_padded(hdr_spec_len)); 499 500 if (conn->datadgst_en) 501 tx_hash = tcp_sw_conn->tx_hash; 502 503 iscsi_segment_init_linear(&tcp_sw_conn->out.data_segment, 504 data, len, NULL, tx_hash); 505 } 506 507 static int iscsi_sw_tcp_pdu_init(struct iscsi_task *task, 508 unsigned int offset, unsigned int count) 509 { 510 struct iscsi_conn *conn = task->conn; 511 int err = 0; 512 513 iscsi_sw_tcp_send_hdr_prep(conn, task->hdr, task->hdr_len); 514 515 if (!count) 516 return 0; 517 518 if (!task->sc) 519 iscsi_sw_tcp_send_linear_data_prep(conn, task->data, count); 520 else { 521 struct scsi_data_buffer *sdb = scsi_out(task->sc); 522 523 err = iscsi_sw_tcp_send_data_prep(conn, sdb->table.sgl, 524 sdb->table.nents, offset, 525 count); 526 } 527 528 if (err) { 529 /* got invalid offset/len */ 530 return -EIO; 531 } 532 return 0; 533 } 534 535 static int iscsi_sw_tcp_pdu_alloc(struct iscsi_task *task, uint8_t opcode) 536 { 537 struct iscsi_tcp_task *tcp_task = task->dd_data; 538 539 task->hdr = task->dd_data + sizeof(*tcp_task); 540 task->hdr_max = sizeof(struct iscsi_sw_tcp_hdrbuf) - ISCSI_DIGEST_SIZE; 541 return 0; 542 } 543 544 static struct iscsi_cls_conn * 545 iscsi_sw_tcp_conn_create(struct iscsi_cls_session *cls_session, 546 uint32_t conn_idx) 547 { 548 struct iscsi_conn *conn; 549 struct iscsi_cls_conn *cls_conn; 550 struct iscsi_tcp_conn *tcp_conn; 551 struct iscsi_sw_tcp_conn *tcp_sw_conn; 552 struct crypto_ahash *tfm; 553 554 cls_conn = iscsi_tcp_conn_setup(cls_session, sizeof(*tcp_sw_conn), 555 conn_idx); 556 if (!cls_conn) 557 return NULL; 558 conn = cls_conn->dd_data; 559 tcp_conn = conn->dd_data; 560 tcp_sw_conn = tcp_conn->dd_data; 561 562 tfm = crypto_alloc_ahash("crc32c", 0, CRYPTO_ALG_ASYNC); 563 if (IS_ERR(tfm)) 564 goto free_conn; 565 566 tcp_sw_conn->tx_hash = ahash_request_alloc(tfm, GFP_KERNEL); 567 if (!tcp_sw_conn->tx_hash) 568 goto free_tfm; 569 ahash_request_set_callback(tcp_sw_conn->tx_hash, 0, NULL, NULL); 570 571 tcp_sw_conn->rx_hash = ahash_request_alloc(tfm, GFP_KERNEL); 572 if (!tcp_sw_conn->rx_hash) 573 goto free_tx_hash; 574 ahash_request_set_callback(tcp_sw_conn->rx_hash, 0, NULL, NULL); 575 576 tcp_conn->rx_hash = tcp_sw_conn->rx_hash; 577 578 return cls_conn; 579 580 free_tx_hash: 581 ahash_request_free(tcp_sw_conn->tx_hash); 582 free_tfm: 583 crypto_free_ahash(tfm); 584 free_conn: 585 iscsi_conn_printk(KERN_ERR, conn, 586 "Could not create connection due to crc32c " 587 "loading error. Make sure the crc32c " 588 "module is built as a module or into the " 589 "kernel\n"); 590 iscsi_tcp_conn_teardown(cls_conn); 591 return NULL; 592 } 593 594 static void iscsi_sw_tcp_release_conn(struct iscsi_conn *conn) 595 { 596 struct iscsi_session *session = conn->session; 597 struct iscsi_tcp_conn *tcp_conn = conn->dd_data; 598 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; 599 struct socket *sock = tcp_sw_conn->sock; 600 601 if (!sock) 602 return; 603 604 sock_hold(sock->sk); 605 iscsi_sw_tcp_conn_restore_callbacks(conn); 606 sock_put(sock->sk); 607 608 spin_lock_bh(&session->frwd_lock); 609 tcp_sw_conn->sock = NULL; 610 spin_unlock_bh(&session->frwd_lock); 611 sockfd_put(sock); 612 } 613 614 static void iscsi_sw_tcp_conn_destroy(struct iscsi_cls_conn *cls_conn) 615 { 616 struct iscsi_conn *conn = cls_conn->dd_data; 617 struct iscsi_tcp_conn *tcp_conn = conn->dd_data; 618 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; 619 620 iscsi_sw_tcp_release_conn(conn); 621 622 ahash_request_free(tcp_sw_conn->rx_hash); 623 if (tcp_sw_conn->tx_hash) { 624 struct crypto_ahash *tfm; 625 626 tfm = crypto_ahash_reqtfm(tcp_sw_conn->tx_hash); 627 ahash_request_free(tcp_sw_conn->tx_hash); 628 crypto_free_ahash(tfm); 629 } 630 631 iscsi_tcp_conn_teardown(cls_conn); 632 } 633 634 static void iscsi_sw_tcp_conn_stop(struct iscsi_cls_conn *cls_conn, int flag) 635 { 636 struct iscsi_conn *conn = cls_conn->dd_data; 637 struct iscsi_tcp_conn *tcp_conn = conn->dd_data; 638 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; 639 struct socket *sock = tcp_sw_conn->sock; 640 641 /* userspace may have goofed up and not bound us */ 642 if (!sock) 643 return; 644 645 sock->sk->sk_err = EIO; 646 wake_up_interruptible(sk_sleep(sock->sk)); 647 648 /* stop xmit side */ 649 iscsi_suspend_tx(conn); 650 651 /* stop recv side and release socket */ 652 iscsi_sw_tcp_release_conn(conn); 653 654 iscsi_conn_stop(cls_conn, flag); 655 } 656 657 static int 658 iscsi_sw_tcp_conn_bind(struct iscsi_cls_session *cls_session, 659 struct iscsi_cls_conn *cls_conn, uint64_t transport_eph, 660 int is_leading) 661 { 662 struct iscsi_session *session = cls_session->dd_data; 663 struct iscsi_conn *conn = cls_conn->dd_data; 664 struct iscsi_tcp_conn *tcp_conn = conn->dd_data; 665 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; 666 struct sock *sk; 667 struct socket *sock; 668 int err; 669 670 /* lookup for existing socket */ 671 sock = sockfd_lookup((int)transport_eph, &err); 672 if (!sock) { 673 iscsi_conn_printk(KERN_ERR, conn, 674 "sockfd_lookup failed %d\n", err); 675 return -EEXIST; 676 } 677 678 err = iscsi_conn_bind(cls_session, cls_conn, is_leading); 679 if (err) 680 goto free_socket; 681 682 spin_lock_bh(&session->frwd_lock); 683 /* bind iSCSI connection and socket */ 684 tcp_sw_conn->sock = sock; 685 spin_unlock_bh(&session->frwd_lock); 686 687 /* setup Socket parameters */ 688 sk = sock->sk; 689 sk->sk_reuse = SK_CAN_REUSE; 690 sk->sk_sndtimeo = 15 * HZ; /* FIXME: make it configurable */ 691 sk->sk_allocation = GFP_ATOMIC; 692 sk_set_memalloc(sk); 693 694 iscsi_sw_tcp_conn_set_callbacks(conn); 695 tcp_sw_conn->sendpage = tcp_sw_conn->sock->ops->sendpage; 696 /* 697 * set receive state machine into initial state 698 */ 699 iscsi_tcp_hdr_recv_prep(tcp_conn); 700 return 0; 701 702 free_socket: 703 sockfd_put(sock); 704 return err; 705 } 706 707 static int iscsi_sw_tcp_conn_set_param(struct iscsi_cls_conn *cls_conn, 708 enum iscsi_param param, char *buf, 709 int buflen) 710 { 711 struct iscsi_conn *conn = cls_conn->dd_data; 712 struct iscsi_tcp_conn *tcp_conn = conn->dd_data; 713 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; 714 715 switch(param) { 716 case ISCSI_PARAM_HDRDGST_EN: 717 iscsi_set_param(cls_conn, param, buf, buflen); 718 break; 719 case ISCSI_PARAM_DATADGST_EN: 720 iscsi_set_param(cls_conn, param, buf, buflen); 721 tcp_sw_conn->sendpage = conn->datadgst_en ? 722 sock_no_sendpage : tcp_sw_conn->sock->ops->sendpage; 723 break; 724 case ISCSI_PARAM_MAX_R2T: 725 return iscsi_tcp_set_max_r2t(conn, buf); 726 default: 727 return iscsi_set_param(cls_conn, param, buf, buflen); 728 } 729 730 return 0; 731 } 732 733 static int iscsi_sw_tcp_conn_get_param(struct iscsi_cls_conn *cls_conn, 734 enum iscsi_param param, char *buf) 735 { 736 struct iscsi_conn *conn = cls_conn->dd_data; 737 struct iscsi_tcp_conn *tcp_conn = conn->dd_data; 738 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; 739 struct sockaddr_in6 addr; 740 int rc; 741 742 switch(param) { 743 case ISCSI_PARAM_CONN_PORT: 744 case ISCSI_PARAM_CONN_ADDRESS: 745 case ISCSI_PARAM_LOCAL_PORT: 746 spin_lock_bh(&conn->session->frwd_lock); 747 if (!tcp_sw_conn || !tcp_sw_conn->sock) { 748 spin_unlock_bh(&conn->session->frwd_lock); 749 return -ENOTCONN; 750 } 751 if (param == ISCSI_PARAM_LOCAL_PORT) 752 rc = kernel_getsockname(tcp_sw_conn->sock, 753 (struct sockaddr *)&addr); 754 else 755 rc = kernel_getpeername(tcp_sw_conn->sock, 756 (struct sockaddr *)&addr); 757 spin_unlock_bh(&conn->session->frwd_lock); 758 if (rc < 0) 759 return rc; 760 761 return iscsi_conn_get_addr_param((struct sockaddr_storage *) 762 &addr, param, buf); 763 default: 764 return iscsi_conn_get_param(cls_conn, param, buf); 765 } 766 767 return 0; 768 } 769 770 static int iscsi_sw_tcp_host_get_param(struct Scsi_Host *shost, 771 enum iscsi_host_param param, char *buf) 772 { 773 struct iscsi_sw_tcp_host *tcp_sw_host = iscsi_host_priv(shost); 774 struct iscsi_session *session = tcp_sw_host->session; 775 struct iscsi_conn *conn; 776 struct iscsi_tcp_conn *tcp_conn; 777 struct iscsi_sw_tcp_conn *tcp_sw_conn; 778 struct sockaddr_in6 addr; 779 int rc; 780 781 switch (param) { 782 case ISCSI_HOST_PARAM_IPADDRESS: 783 if (!session) 784 return -ENOTCONN; 785 786 spin_lock_bh(&session->frwd_lock); 787 conn = session->leadconn; 788 if (!conn) { 789 spin_unlock_bh(&session->frwd_lock); 790 return -ENOTCONN; 791 } 792 tcp_conn = conn->dd_data; 793 794 tcp_sw_conn = tcp_conn->dd_data; 795 if (!tcp_sw_conn->sock) { 796 spin_unlock_bh(&session->frwd_lock); 797 return -ENOTCONN; 798 } 799 800 rc = kernel_getsockname(tcp_sw_conn->sock, 801 (struct sockaddr *)&addr); 802 spin_unlock_bh(&session->frwd_lock); 803 if (rc < 0) 804 return rc; 805 806 return iscsi_conn_get_addr_param((struct sockaddr_storage *) 807 &addr, 808 (enum iscsi_param)param, buf); 809 default: 810 return iscsi_host_get_param(shost, param, buf); 811 } 812 813 return 0; 814 } 815 816 static void 817 iscsi_sw_tcp_conn_get_stats(struct iscsi_cls_conn *cls_conn, 818 struct iscsi_stats *stats) 819 { 820 struct iscsi_conn *conn = cls_conn->dd_data; 821 struct iscsi_tcp_conn *tcp_conn = conn->dd_data; 822 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; 823 824 stats->custom_length = 3; 825 strcpy(stats->custom[0].desc, "tx_sendpage_failures"); 826 stats->custom[0].value = tcp_sw_conn->sendpage_failures_cnt; 827 strcpy(stats->custom[1].desc, "rx_discontiguous_hdr"); 828 stats->custom[1].value = tcp_sw_conn->discontiguous_hdr_cnt; 829 strcpy(stats->custom[2].desc, "eh_abort_cnt"); 830 stats->custom[2].value = conn->eh_abort_cnt; 831 832 iscsi_tcp_conn_get_stats(cls_conn, stats); 833 } 834 835 static struct iscsi_cls_session * 836 iscsi_sw_tcp_session_create(struct iscsi_endpoint *ep, uint16_t cmds_max, 837 uint16_t qdepth, uint32_t initial_cmdsn) 838 { 839 struct iscsi_cls_session *cls_session; 840 struct iscsi_session *session; 841 struct iscsi_sw_tcp_host *tcp_sw_host; 842 struct Scsi_Host *shost; 843 844 if (ep) { 845 printk(KERN_ERR "iscsi_tcp: invalid ep %p.\n", ep); 846 return NULL; 847 } 848 849 shost = iscsi_host_alloc(&iscsi_sw_tcp_sht, 850 sizeof(struct iscsi_sw_tcp_host), 1); 851 if (!shost) 852 return NULL; 853 shost->transportt = iscsi_sw_tcp_scsi_transport; 854 shost->cmd_per_lun = qdepth; 855 shost->max_lun = iscsi_max_lun; 856 shost->max_id = 0; 857 shost->max_channel = 0; 858 shost->max_cmd_len = SCSI_MAX_VARLEN_CDB_SIZE; 859 860 if (iscsi_host_add(shost, NULL)) 861 goto free_host; 862 863 cls_session = iscsi_session_setup(&iscsi_sw_tcp_transport, shost, 864 cmds_max, 0, 865 sizeof(struct iscsi_tcp_task) + 866 sizeof(struct iscsi_sw_tcp_hdrbuf), 867 initial_cmdsn, 0); 868 if (!cls_session) 869 goto remove_host; 870 session = cls_session->dd_data; 871 tcp_sw_host = iscsi_host_priv(shost); 872 tcp_sw_host->session = session; 873 874 shost->can_queue = session->scsi_cmds_max; 875 if (iscsi_tcp_r2tpool_alloc(session)) 876 goto remove_session; 877 return cls_session; 878 879 remove_session: 880 iscsi_session_teardown(cls_session); 881 remove_host: 882 iscsi_host_remove(shost); 883 free_host: 884 iscsi_host_free(shost); 885 return NULL; 886 } 887 888 static void iscsi_sw_tcp_session_destroy(struct iscsi_cls_session *cls_session) 889 { 890 struct Scsi_Host *shost = iscsi_session_to_shost(cls_session); 891 892 iscsi_tcp_r2tpool_free(cls_session->dd_data); 893 iscsi_session_teardown(cls_session); 894 895 iscsi_host_remove(shost); 896 iscsi_host_free(shost); 897 } 898 899 static umode_t iscsi_sw_tcp_attr_is_visible(int param_type, int param) 900 { 901 switch (param_type) { 902 case ISCSI_HOST_PARAM: 903 switch (param) { 904 case ISCSI_HOST_PARAM_NETDEV_NAME: 905 case ISCSI_HOST_PARAM_HWADDRESS: 906 case ISCSI_HOST_PARAM_IPADDRESS: 907 case ISCSI_HOST_PARAM_INITIATOR_NAME: 908 return S_IRUGO; 909 default: 910 return 0; 911 } 912 case ISCSI_PARAM: 913 switch (param) { 914 case ISCSI_PARAM_MAX_RECV_DLENGTH: 915 case ISCSI_PARAM_MAX_XMIT_DLENGTH: 916 case ISCSI_PARAM_HDRDGST_EN: 917 case ISCSI_PARAM_DATADGST_EN: 918 case ISCSI_PARAM_CONN_ADDRESS: 919 case ISCSI_PARAM_CONN_PORT: 920 case ISCSI_PARAM_LOCAL_PORT: 921 case ISCSI_PARAM_EXP_STATSN: 922 case ISCSI_PARAM_PERSISTENT_ADDRESS: 923 case ISCSI_PARAM_PERSISTENT_PORT: 924 case ISCSI_PARAM_PING_TMO: 925 case ISCSI_PARAM_RECV_TMO: 926 case ISCSI_PARAM_INITIAL_R2T_EN: 927 case ISCSI_PARAM_MAX_R2T: 928 case ISCSI_PARAM_IMM_DATA_EN: 929 case ISCSI_PARAM_FIRST_BURST: 930 case ISCSI_PARAM_MAX_BURST: 931 case ISCSI_PARAM_PDU_INORDER_EN: 932 case ISCSI_PARAM_DATASEQ_INORDER_EN: 933 case ISCSI_PARAM_ERL: 934 case ISCSI_PARAM_TARGET_NAME: 935 case ISCSI_PARAM_TPGT: 936 case ISCSI_PARAM_USERNAME: 937 case ISCSI_PARAM_PASSWORD: 938 case ISCSI_PARAM_USERNAME_IN: 939 case ISCSI_PARAM_PASSWORD_IN: 940 case ISCSI_PARAM_FAST_ABORT: 941 case ISCSI_PARAM_ABORT_TMO: 942 case ISCSI_PARAM_LU_RESET_TMO: 943 case ISCSI_PARAM_TGT_RESET_TMO: 944 case ISCSI_PARAM_IFACE_NAME: 945 case ISCSI_PARAM_INITIATOR_NAME: 946 return S_IRUGO; 947 default: 948 return 0; 949 } 950 } 951 952 return 0; 953 } 954 955 static int iscsi_sw_tcp_slave_alloc(struct scsi_device *sdev) 956 { 957 blk_queue_flag_set(QUEUE_FLAG_BIDI, sdev->request_queue); 958 return 0; 959 } 960 961 static int iscsi_sw_tcp_slave_configure(struct scsi_device *sdev) 962 { 963 struct iscsi_sw_tcp_host *tcp_sw_host = iscsi_host_priv(sdev->host); 964 struct iscsi_session *session = tcp_sw_host->session; 965 struct iscsi_conn *conn = session->leadconn; 966 967 if (conn->datadgst_en) 968 sdev->request_queue->backing_dev_info->capabilities 969 |= BDI_CAP_STABLE_WRITES; 970 blk_queue_dma_alignment(sdev->request_queue, 0); 971 return 0; 972 } 973 974 static struct scsi_host_template iscsi_sw_tcp_sht = { 975 .module = THIS_MODULE, 976 .name = "iSCSI Initiator over TCP/IP", 977 .queuecommand = iscsi_queuecommand, 978 .change_queue_depth = scsi_change_queue_depth, 979 .can_queue = ISCSI_DEF_XMIT_CMDS_MAX - 1, 980 .sg_tablesize = 4096, 981 .max_sectors = 0xFFFF, 982 .cmd_per_lun = ISCSI_DEF_CMD_PER_LUN, 983 .eh_timed_out = iscsi_eh_cmd_timed_out, 984 .eh_abort_handler = iscsi_eh_abort, 985 .eh_device_reset_handler= iscsi_eh_device_reset, 986 .eh_target_reset_handler = iscsi_eh_recover_target, 987 .dma_boundary = PAGE_SIZE - 1, 988 .slave_alloc = iscsi_sw_tcp_slave_alloc, 989 .slave_configure = iscsi_sw_tcp_slave_configure, 990 .target_alloc = iscsi_target_alloc, 991 .proc_name = "iscsi_tcp", 992 .this_id = -1, 993 .track_queue_depth = 1, 994 }; 995 996 static struct iscsi_transport iscsi_sw_tcp_transport = { 997 .owner = THIS_MODULE, 998 .name = "tcp", 999 .caps = CAP_RECOVERY_L0 | CAP_MULTI_R2T | CAP_HDRDGST 1000 | CAP_DATADGST, 1001 /* session management */ 1002 .create_session = iscsi_sw_tcp_session_create, 1003 .destroy_session = iscsi_sw_tcp_session_destroy, 1004 /* connection management */ 1005 .create_conn = iscsi_sw_tcp_conn_create, 1006 .bind_conn = iscsi_sw_tcp_conn_bind, 1007 .destroy_conn = iscsi_sw_tcp_conn_destroy, 1008 .attr_is_visible = iscsi_sw_tcp_attr_is_visible, 1009 .set_param = iscsi_sw_tcp_conn_set_param, 1010 .get_conn_param = iscsi_sw_tcp_conn_get_param, 1011 .get_session_param = iscsi_session_get_param, 1012 .start_conn = iscsi_conn_start, 1013 .stop_conn = iscsi_sw_tcp_conn_stop, 1014 /* iscsi host params */ 1015 .get_host_param = iscsi_sw_tcp_host_get_param, 1016 .set_host_param = iscsi_host_set_param, 1017 /* IO */ 1018 .send_pdu = iscsi_conn_send_pdu, 1019 .get_stats = iscsi_sw_tcp_conn_get_stats, 1020 /* iscsi task/cmd helpers */ 1021 .init_task = iscsi_tcp_task_init, 1022 .xmit_task = iscsi_tcp_task_xmit, 1023 .cleanup_task = iscsi_tcp_cleanup_task, 1024 /* low level pdu helpers */ 1025 .xmit_pdu = iscsi_sw_tcp_pdu_xmit, 1026 .init_pdu = iscsi_sw_tcp_pdu_init, 1027 .alloc_pdu = iscsi_sw_tcp_pdu_alloc, 1028 /* recovery */ 1029 .session_recovery_timedout = iscsi_session_recovery_timedout, 1030 }; 1031 1032 static int __init iscsi_sw_tcp_init(void) 1033 { 1034 if (iscsi_max_lun < 1) { 1035 printk(KERN_ERR "iscsi_tcp: Invalid max_lun value of %u\n", 1036 iscsi_max_lun); 1037 return -EINVAL; 1038 } 1039 1040 iscsi_sw_tcp_scsi_transport = iscsi_register_transport( 1041 &iscsi_sw_tcp_transport); 1042 if (!iscsi_sw_tcp_scsi_transport) 1043 return -ENODEV; 1044 1045 return 0; 1046 } 1047 1048 static void __exit iscsi_sw_tcp_exit(void) 1049 { 1050 iscsi_unregister_transport(&iscsi_sw_tcp_transport); 1051 } 1052 1053 module_init(iscsi_sw_tcp_init); 1054 module_exit(iscsi_sw_tcp_exit); 1055