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