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