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 **/ 311 static int iscsi_sw_tcp_xmit(struct iscsi_conn *conn) 312 { 313 struct iscsi_tcp_conn *tcp_conn = conn->dd_data; 314 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; 315 struct iscsi_segment *segment = &tcp_sw_conn->out.segment; 316 unsigned int consumed = 0; 317 int rc = 0; 318 319 while (1) { 320 rc = iscsi_sw_tcp_xmit_segment(tcp_conn, segment); 321 /* 322 * We may not have been able to send data because the conn 323 * is getting stopped. libiscsi will know so propagate err 324 * for it to do the right thing. 325 */ 326 if (rc == -EAGAIN) 327 return rc; 328 else if (rc < 0) { 329 rc = ISCSI_ERR_XMIT_FAILED; 330 goto error; 331 } else if (rc == 0) 332 break; 333 334 consumed += rc; 335 336 if (segment->total_copied >= segment->total_size) { 337 if (segment->done != NULL) { 338 rc = segment->done(tcp_conn, segment); 339 if (rc != 0) 340 goto error; 341 } 342 } 343 } 344 345 ISCSI_SW_TCP_DBG(conn, "xmit %d bytes\n", consumed); 346 347 conn->txdata_octets += consumed; 348 return consumed; 349 350 error: 351 /* Transmit error. We could initiate error recovery 352 * here. */ 353 ISCSI_SW_TCP_DBG(conn, "Error sending PDU, errno=%d\n", rc); 354 iscsi_conn_failure(conn, rc); 355 return -EIO; 356 } 357 358 /** 359 * iscsi_tcp_xmit_qlen - return the number of bytes queued for xmit 360 */ 361 static inline int iscsi_sw_tcp_xmit_qlen(struct iscsi_conn *conn) 362 { 363 struct iscsi_tcp_conn *tcp_conn = conn->dd_data; 364 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; 365 struct iscsi_segment *segment = &tcp_sw_conn->out.segment; 366 367 return segment->total_copied - segment->total_size; 368 } 369 370 static int iscsi_sw_tcp_pdu_xmit(struct iscsi_task *task) 371 { 372 struct iscsi_conn *conn = task->conn; 373 unsigned int noreclaim_flag; 374 int rc = 0; 375 376 noreclaim_flag = memalloc_noreclaim_save(); 377 378 while (iscsi_sw_tcp_xmit_qlen(conn)) { 379 rc = iscsi_sw_tcp_xmit(conn); 380 if (rc == 0) { 381 rc = -EAGAIN; 382 break; 383 } 384 if (rc < 0) 385 break; 386 rc = 0; 387 } 388 389 memalloc_noreclaim_restore(noreclaim_flag); 390 return rc; 391 } 392 393 /* 394 * This is called when we're done sending the header. 395 * Simply copy the data_segment to the send segment, and return. 396 */ 397 static int iscsi_sw_tcp_send_hdr_done(struct iscsi_tcp_conn *tcp_conn, 398 struct iscsi_segment *segment) 399 { 400 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; 401 402 tcp_sw_conn->out.segment = tcp_sw_conn->out.data_segment; 403 ISCSI_SW_TCP_DBG(tcp_conn->iscsi_conn, 404 "Header done. Next segment size %u total_size %u\n", 405 tcp_sw_conn->out.segment.size, 406 tcp_sw_conn->out.segment.total_size); 407 return 0; 408 } 409 410 static void iscsi_sw_tcp_send_hdr_prep(struct iscsi_conn *conn, void *hdr, 411 size_t hdrlen) 412 { 413 struct iscsi_tcp_conn *tcp_conn = conn->dd_data; 414 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; 415 416 ISCSI_SW_TCP_DBG(conn, "%s\n", conn->hdrdgst_en ? 417 "digest enabled" : "digest disabled"); 418 419 /* Clear the data segment - needs to be filled in by the 420 * caller using iscsi_tcp_send_data_prep() */ 421 memset(&tcp_sw_conn->out.data_segment, 0, 422 sizeof(struct iscsi_segment)); 423 424 /* If header digest is enabled, compute the CRC and 425 * place the digest into the same buffer. We make 426 * sure that both iscsi_tcp_task and mtask have 427 * sufficient room. 428 */ 429 if (conn->hdrdgst_en) { 430 iscsi_tcp_dgst_header(tcp_sw_conn->tx_hash, hdr, hdrlen, 431 hdr + hdrlen); 432 hdrlen += ISCSI_DIGEST_SIZE; 433 } 434 435 /* Remember header pointer for later, when we need 436 * to decide whether there's a payload to go along 437 * with the header. */ 438 tcp_sw_conn->out.hdr = hdr; 439 440 iscsi_segment_init_linear(&tcp_sw_conn->out.segment, hdr, hdrlen, 441 iscsi_sw_tcp_send_hdr_done, NULL); 442 } 443 444 /* 445 * Prepare the send buffer for the payload data. 446 * Padding and checksumming will all be taken care 447 * of by the iscsi_segment routines. 448 */ 449 static int 450 iscsi_sw_tcp_send_data_prep(struct iscsi_conn *conn, struct scatterlist *sg, 451 unsigned int count, unsigned int offset, 452 unsigned int len) 453 { 454 struct iscsi_tcp_conn *tcp_conn = conn->dd_data; 455 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; 456 struct ahash_request *tx_hash = NULL; 457 unsigned int hdr_spec_len; 458 459 ISCSI_SW_TCP_DBG(conn, "offset=%d, datalen=%d %s\n", offset, len, 460 conn->datadgst_en ? 461 "digest enabled" : "digest disabled"); 462 463 /* Make sure the datalen matches what the caller 464 said he would send. */ 465 hdr_spec_len = ntoh24(tcp_sw_conn->out.hdr->dlength); 466 WARN_ON(iscsi_padded(len) != iscsi_padded(hdr_spec_len)); 467 468 if (conn->datadgst_en) 469 tx_hash = tcp_sw_conn->tx_hash; 470 471 return iscsi_segment_seek_sg(&tcp_sw_conn->out.data_segment, 472 sg, count, offset, len, 473 NULL, tx_hash); 474 } 475 476 static void 477 iscsi_sw_tcp_send_linear_data_prep(struct iscsi_conn *conn, void *data, 478 size_t len) 479 { 480 struct iscsi_tcp_conn *tcp_conn = conn->dd_data; 481 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; 482 struct ahash_request *tx_hash = NULL; 483 unsigned int hdr_spec_len; 484 485 ISCSI_SW_TCP_DBG(conn, "datalen=%zd %s\n", len, conn->datadgst_en ? 486 "digest enabled" : "digest disabled"); 487 488 /* Make sure the datalen matches what the caller 489 said he would send. */ 490 hdr_spec_len = ntoh24(tcp_sw_conn->out.hdr->dlength); 491 WARN_ON(iscsi_padded(len) != iscsi_padded(hdr_spec_len)); 492 493 if (conn->datadgst_en) 494 tx_hash = tcp_sw_conn->tx_hash; 495 496 iscsi_segment_init_linear(&tcp_sw_conn->out.data_segment, 497 data, len, NULL, tx_hash); 498 } 499 500 static int iscsi_sw_tcp_pdu_init(struct iscsi_task *task, 501 unsigned int offset, unsigned int count) 502 { 503 struct iscsi_conn *conn = task->conn; 504 int err = 0; 505 506 iscsi_sw_tcp_send_hdr_prep(conn, task->hdr, task->hdr_len); 507 508 if (!count) 509 return 0; 510 511 if (!task->sc) 512 iscsi_sw_tcp_send_linear_data_prep(conn, task->data, count); 513 else { 514 struct scsi_data_buffer *sdb = scsi_out(task->sc); 515 516 err = iscsi_sw_tcp_send_data_prep(conn, sdb->table.sgl, 517 sdb->table.nents, offset, 518 count); 519 } 520 521 if (err) { 522 /* got invalid offset/len */ 523 return -EIO; 524 } 525 return 0; 526 } 527 528 static int iscsi_sw_tcp_pdu_alloc(struct iscsi_task *task, uint8_t opcode) 529 { 530 struct iscsi_tcp_task *tcp_task = task->dd_data; 531 532 task->hdr = task->dd_data + sizeof(*tcp_task); 533 task->hdr_max = sizeof(struct iscsi_sw_tcp_hdrbuf) - ISCSI_DIGEST_SIZE; 534 return 0; 535 } 536 537 static struct iscsi_cls_conn * 538 iscsi_sw_tcp_conn_create(struct iscsi_cls_session *cls_session, 539 uint32_t conn_idx) 540 { 541 struct iscsi_conn *conn; 542 struct iscsi_cls_conn *cls_conn; 543 struct iscsi_tcp_conn *tcp_conn; 544 struct iscsi_sw_tcp_conn *tcp_sw_conn; 545 struct crypto_ahash *tfm; 546 547 cls_conn = iscsi_tcp_conn_setup(cls_session, sizeof(*tcp_sw_conn), 548 conn_idx); 549 if (!cls_conn) 550 return NULL; 551 conn = cls_conn->dd_data; 552 tcp_conn = conn->dd_data; 553 tcp_sw_conn = tcp_conn->dd_data; 554 555 tfm = crypto_alloc_ahash("crc32c", 0, CRYPTO_ALG_ASYNC); 556 if (IS_ERR(tfm)) 557 goto free_conn; 558 559 tcp_sw_conn->tx_hash = ahash_request_alloc(tfm, GFP_KERNEL); 560 if (!tcp_sw_conn->tx_hash) 561 goto free_tfm; 562 ahash_request_set_callback(tcp_sw_conn->tx_hash, 0, NULL, NULL); 563 564 tcp_sw_conn->rx_hash = ahash_request_alloc(tfm, GFP_KERNEL); 565 if (!tcp_sw_conn->rx_hash) 566 goto free_tx_hash; 567 ahash_request_set_callback(tcp_sw_conn->rx_hash, 0, NULL, NULL); 568 569 tcp_conn->rx_hash = tcp_sw_conn->rx_hash; 570 571 return cls_conn; 572 573 free_tx_hash: 574 ahash_request_free(tcp_sw_conn->tx_hash); 575 free_tfm: 576 crypto_free_ahash(tfm); 577 free_conn: 578 iscsi_conn_printk(KERN_ERR, conn, 579 "Could not create connection due to crc32c " 580 "loading error. Make sure the crc32c " 581 "module is built as a module or into the " 582 "kernel\n"); 583 iscsi_tcp_conn_teardown(cls_conn); 584 return NULL; 585 } 586 587 static void iscsi_sw_tcp_release_conn(struct iscsi_conn *conn) 588 { 589 struct iscsi_session *session = conn->session; 590 struct iscsi_tcp_conn *tcp_conn = conn->dd_data; 591 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; 592 struct socket *sock = tcp_sw_conn->sock; 593 594 if (!sock) 595 return; 596 597 sock_hold(sock->sk); 598 iscsi_sw_tcp_conn_restore_callbacks(conn); 599 sock_put(sock->sk); 600 601 spin_lock_bh(&session->frwd_lock); 602 tcp_sw_conn->sock = NULL; 603 spin_unlock_bh(&session->frwd_lock); 604 sockfd_put(sock); 605 } 606 607 static void iscsi_sw_tcp_conn_destroy(struct iscsi_cls_conn *cls_conn) 608 { 609 struct iscsi_conn *conn = cls_conn->dd_data; 610 struct iscsi_tcp_conn *tcp_conn = conn->dd_data; 611 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; 612 613 iscsi_sw_tcp_release_conn(conn); 614 615 ahash_request_free(tcp_sw_conn->rx_hash); 616 if (tcp_sw_conn->tx_hash) { 617 struct crypto_ahash *tfm; 618 619 tfm = crypto_ahash_reqtfm(tcp_sw_conn->tx_hash); 620 ahash_request_free(tcp_sw_conn->tx_hash); 621 crypto_free_ahash(tfm); 622 } 623 624 iscsi_tcp_conn_teardown(cls_conn); 625 } 626 627 static void iscsi_sw_tcp_conn_stop(struct iscsi_cls_conn *cls_conn, int flag) 628 { 629 struct iscsi_conn *conn = cls_conn->dd_data; 630 struct iscsi_tcp_conn *tcp_conn = conn->dd_data; 631 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; 632 struct socket *sock = tcp_sw_conn->sock; 633 634 /* userspace may have goofed up and not bound us */ 635 if (!sock) 636 return; 637 638 sock->sk->sk_err = EIO; 639 wake_up_interruptible(sk_sleep(sock->sk)); 640 641 /* stop xmit side */ 642 iscsi_suspend_tx(conn); 643 644 /* stop recv side and release socket */ 645 iscsi_sw_tcp_release_conn(conn); 646 647 iscsi_conn_stop(cls_conn, flag); 648 } 649 650 static int 651 iscsi_sw_tcp_conn_bind(struct iscsi_cls_session *cls_session, 652 struct iscsi_cls_conn *cls_conn, uint64_t transport_eph, 653 int is_leading) 654 { 655 struct iscsi_session *session = cls_session->dd_data; 656 struct iscsi_conn *conn = cls_conn->dd_data; 657 struct iscsi_tcp_conn *tcp_conn = conn->dd_data; 658 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; 659 struct sock *sk; 660 struct socket *sock; 661 int err; 662 663 /* lookup for existing socket */ 664 sock = sockfd_lookup((int)transport_eph, &err); 665 if (!sock) { 666 iscsi_conn_printk(KERN_ERR, conn, 667 "sockfd_lookup failed %d\n", err); 668 return -EEXIST; 669 } 670 671 err = iscsi_conn_bind(cls_session, cls_conn, is_leading); 672 if (err) 673 goto free_socket; 674 675 spin_lock_bh(&session->frwd_lock); 676 /* bind iSCSI connection and socket */ 677 tcp_sw_conn->sock = sock; 678 spin_unlock_bh(&session->frwd_lock); 679 680 /* setup Socket parameters */ 681 sk = sock->sk; 682 sk->sk_reuse = SK_CAN_REUSE; 683 sk->sk_sndtimeo = 15 * HZ; /* FIXME: make it configurable */ 684 sk->sk_allocation = GFP_ATOMIC; 685 sk_set_memalloc(sk); 686 687 iscsi_sw_tcp_conn_set_callbacks(conn); 688 tcp_sw_conn->sendpage = tcp_sw_conn->sock->ops->sendpage; 689 /* 690 * set receive state machine into initial state 691 */ 692 iscsi_tcp_hdr_recv_prep(tcp_conn); 693 return 0; 694 695 free_socket: 696 sockfd_put(sock); 697 return err; 698 } 699 700 static int iscsi_sw_tcp_conn_set_param(struct iscsi_cls_conn *cls_conn, 701 enum iscsi_param param, char *buf, 702 int buflen) 703 { 704 struct iscsi_conn *conn = cls_conn->dd_data; 705 struct iscsi_tcp_conn *tcp_conn = conn->dd_data; 706 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; 707 708 switch(param) { 709 case ISCSI_PARAM_HDRDGST_EN: 710 iscsi_set_param(cls_conn, param, buf, buflen); 711 break; 712 case ISCSI_PARAM_DATADGST_EN: 713 iscsi_set_param(cls_conn, param, buf, buflen); 714 tcp_sw_conn->sendpage = conn->datadgst_en ? 715 sock_no_sendpage : tcp_sw_conn->sock->ops->sendpage; 716 break; 717 case ISCSI_PARAM_MAX_R2T: 718 return iscsi_tcp_set_max_r2t(conn, buf); 719 default: 720 return iscsi_set_param(cls_conn, param, buf, buflen); 721 } 722 723 return 0; 724 } 725 726 static int iscsi_sw_tcp_conn_get_param(struct iscsi_cls_conn *cls_conn, 727 enum iscsi_param param, char *buf) 728 { 729 struct iscsi_conn *conn = cls_conn->dd_data; 730 struct iscsi_tcp_conn *tcp_conn = conn->dd_data; 731 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; 732 struct sockaddr_in6 addr; 733 int rc, len; 734 735 switch(param) { 736 case ISCSI_PARAM_CONN_PORT: 737 case ISCSI_PARAM_CONN_ADDRESS: 738 case ISCSI_PARAM_LOCAL_PORT: 739 spin_lock_bh(&conn->session->frwd_lock); 740 if (!tcp_sw_conn || !tcp_sw_conn->sock) { 741 spin_unlock_bh(&conn->session->frwd_lock); 742 return -ENOTCONN; 743 } 744 if (param == ISCSI_PARAM_LOCAL_PORT) 745 rc = kernel_getsockname(tcp_sw_conn->sock, 746 (struct sockaddr *)&addr, &len); 747 else 748 rc = kernel_getpeername(tcp_sw_conn->sock, 749 (struct sockaddr *)&addr, &len); 750 spin_unlock_bh(&conn->session->frwd_lock); 751 if (rc) 752 return rc; 753 754 return iscsi_conn_get_addr_param((struct sockaddr_storage *) 755 &addr, param, buf); 756 default: 757 return iscsi_conn_get_param(cls_conn, param, buf); 758 } 759 760 return 0; 761 } 762 763 static int iscsi_sw_tcp_host_get_param(struct Scsi_Host *shost, 764 enum iscsi_host_param param, char *buf) 765 { 766 struct iscsi_sw_tcp_host *tcp_sw_host = iscsi_host_priv(shost); 767 struct iscsi_session *session = tcp_sw_host->session; 768 struct iscsi_conn *conn; 769 struct iscsi_tcp_conn *tcp_conn; 770 struct iscsi_sw_tcp_conn *tcp_sw_conn; 771 struct sockaddr_in6 addr; 772 int rc, len; 773 774 switch (param) { 775 case ISCSI_HOST_PARAM_IPADDRESS: 776 if (!session) 777 return -ENOTCONN; 778 779 spin_lock_bh(&session->frwd_lock); 780 conn = session->leadconn; 781 if (!conn) { 782 spin_unlock_bh(&session->frwd_lock); 783 return -ENOTCONN; 784 } 785 tcp_conn = conn->dd_data; 786 787 tcp_sw_conn = tcp_conn->dd_data; 788 if (!tcp_sw_conn->sock) { 789 spin_unlock_bh(&session->frwd_lock); 790 return -ENOTCONN; 791 } 792 793 rc = kernel_getsockname(tcp_sw_conn->sock, 794 (struct sockaddr *)&addr, &len); 795 spin_unlock_bh(&session->frwd_lock); 796 if (rc) 797 return rc; 798 799 return iscsi_conn_get_addr_param((struct sockaddr_storage *) 800 &addr, param, buf); 801 default: 802 return iscsi_host_get_param(shost, param, buf); 803 } 804 805 return 0; 806 } 807 808 static void 809 iscsi_sw_tcp_conn_get_stats(struct iscsi_cls_conn *cls_conn, 810 struct iscsi_stats *stats) 811 { 812 struct iscsi_conn *conn = cls_conn->dd_data; 813 struct iscsi_tcp_conn *tcp_conn = conn->dd_data; 814 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; 815 816 stats->custom_length = 3; 817 strcpy(stats->custom[0].desc, "tx_sendpage_failures"); 818 stats->custom[0].value = tcp_sw_conn->sendpage_failures_cnt; 819 strcpy(stats->custom[1].desc, "rx_discontiguous_hdr"); 820 stats->custom[1].value = tcp_sw_conn->discontiguous_hdr_cnt; 821 strcpy(stats->custom[2].desc, "eh_abort_cnt"); 822 stats->custom[2].value = conn->eh_abort_cnt; 823 824 iscsi_tcp_conn_get_stats(cls_conn, stats); 825 } 826 827 static struct iscsi_cls_session * 828 iscsi_sw_tcp_session_create(struct iscsi_endpoint *ep, uint16_t cmds_max, 829 uint16_t qdepth, uint32_t initial_cmdsn) 830 { 831 struct iscsi_cls_session *cls_session; 832 struct iscsi_session *session; 833 struct iscsi_sw_tcp_host *tcp_sw_host; 834 struct Scsi_Host *shost; 835 836 if (ep) { 837 printk(KERN_ERR "iscsi_tcp: invalid ep %p.\n", ep); 838 return NULL; 839 } 840 841 shost = iscsi_host_alloc(&iscsi_sw_tcp_sht, 842 sizeof(struct iscsi_sw_tcp_host), 1); 843 if (!shost) 844 return NULL; 845 shost->transportt = iscsi_sw_tcp_scsi_transport; 846 shost->cmd_per_lun = qdepth; 847 shost->max_lun = iscsi_max_lun; 848 shost->max_id = 0; 849 shost->max_channel = 0; 850 shost->max_cmd_len = SCSI_MAX_VARLEN_CDB_SIZE; 851 852 if (iscsi_host_add(shost, NULL)) 853 goto free_host; 854 855 cls_session = iscsi_session_setup(&iscsi_sw_tcp_transport, shost, 856 cmds_max, 0, 857 sizeof(struct iscsi_tcp_task) + 858 sizeof(struct iscsi_sw_tcp_hdrbuf), 859 initial_cmdsn, 0); 860 if (!cls_session) 861 goto remove_host; 862 session = cls_session->dd_data; 863 tcp_sw_host = iscsi_host_priv(shost); 864 tcp_sw_host->session = session; 865 866 shost->can_queue = session->scsi_cmds_max; 867 if (iscsi_tcp_r2tpool_alloc(session)) 868 goto remove_session; 869 return cls_session; 870 871 remove_session: 872 iscsi_session_teardown(cls_session); 873 remove_host: 874 iscsi_host_remove(shost); 875 free_host: 876 iscsi_host_free(shost); 877 return NULL; 878 } 879 880 static void iscsi_sw_tcp_session_destroy(struct iscsi_cls_session *cls_session) 881 { 882 struct Scsi_Host *shost = iscsi_session_to_shost(cls_session); 883 884 iscsi_tcp_r2tpool_free(cls_session->dd_data); 885 iscsi_session_teardown(cls_session); 886 887 iscsi_host_remove(shost); 888 iscsi_host_free(shost); 889 } 890 891 static umode_t iscsi_sw_tcp_attr_is_visible(int param_type, int param) 892 { 893 switch (param_type) { 894 case ISCSI_HOST_PARAM: 895 switch (param) { 896 case ISCSI_HOST_PARAM_NETDEV_NAME: 897 case ISCSI_HOST_PARAM_HWADDRESS: 898 case ISCSI_HOST_PARAM_IPADDRESS: 899 case ISCSI_HOST_PARAM_INITIATOR_NAME: 900 return S_IRUGO; 901 default: 902 return 0; 903 } 904 case ISCSI_PARAM: 905 switch (param) { 906 case ISCSI_PARAM_MAX_RECV_DLENGTH: 907 case ISCSI_PARAM_MAX_XMIT_DLENGTH: 908 case ISCSI_PARAM_HDRDGST_EN: 909 case ISCSI_PARAM_DATADGST_EN: 910 case ISCSI_PARAM_CONN_ADDRESS: 911 case ISCSI_PARAM_CONN_PORT: 912 case ISCSI_PARAM_LOCAL_PORT: 913 case ISCSI_PARAM_EXP_STATSN: 914 case ISCSI_PARAM_PERSISTENT_ADDRESS: 915 case ISCSI_PARAM_PERSISTENT_PORT: 916 case ISCSI_PARAM_PING_TMO: 917 case ISCSI_PARAM_RECV_TMO: 918 case ISCSI_PARAM_INITIAL_R2T_EN: 919 case ISCSI_PARAM_MAX_R2T: 920 case ISCSI_PARAM_IMM_DATA_EN: 921 case ISCSI_PARAM_FIRST_BURST: 922 case ISCSI_PARAM_MAX_BURST: 923 case ISCSI_PARAM_PDU_INORDER_EN: 924 case ISCSI_PARAM_DATASEQ_INORDER_EN: 925 case ISCSI_PARAM_ERL: 926 case ISCSI_PARAM_TARGET_NAME: 927 case ISCSI_PARAM_TPGT: 928 case ISCSI_PARAM_USERNAME: 929 case ISCSI_PARAM_PASSWORD: 930 case ISCSI_PARAM_USERNAME_IN: 931 case ISCSI_PARAM_PASSWORD_IN: 932 case ISCSI_PARAM_FAST_ABORT: 933 case ISCSI_PARAM_ABORT_TMO: 934 case ISCSI_PARAM_LU_RESET_TMO: 935 case ISCSI_PARAM_TGT_RESET_TMO: 936 case ISCSI_PARAM_IFACE_NAME: 937 case ISCSI_PARAM_INITIATOR_NAME: 938 return S_IRUGO; 939 default: 940 return 0; 941 } 942 } 943 944 return 0; 945 } 946 947 static int iscsi_sw_tcp_slave_alloc(struct scsi_device *sdev) 948 { 949 set_bit(QUEUE_FLAG_BIDI, &sdev->request_queue->queue_flags); 950 return 0; 951 } 952 953 static int iscsi_sw_tcp_slave_configure(struct scsi_device *sdev) 954 { 955 blk_queue_bounce_limit(sdev->request_queue, BLK_BOUNCE_ANY); 956 blk_queue_dma_alignment(sdev->request_queue, 0); 957 return 0; 958 } 959 960 static struct scsi_host_template iscsi_sw_tcp_sht = { 961 .module = THIS_MODULE, 962 .name = "iSCSI Initiator over TCP/IP", 963 .queuecommand = iscsi_queuecommand, 964 .change_queue_depth = scsi_change_queue_depth, 965 .can_queue = ISCSI_DEF_XMIT_CMDS_MAX - 1, 966 .sg_tablesize = 4096, 967 .max_sectors = 0xFFFF, 968 .cmd_per_lun = ISCSI_DEF_CMD_PER_LUN, 969 .eh_timed_out = iscsi_eh_cmd_timed_out, 970 .eh_abort_handler = iscsi_eh_abort, 971 .eh_device_reset_handler= iscsi_eh_device_reset, 972 .eh_target_reset_handler = iscsi_eh_recover_target, 973 .use_clustering = DISABLE_CLUSTERING, 974 .slave_alloc = iscsi_sw_tcp_slave_alloc, 975 .slave_configure = iscsi_sw_tcp_slave_configure, 976 .target_alloc = iscsi_target_alloc, 977 .proc_name = "iscsi_tcp", 978 .this_id = -1, 979 .track_queue_depth = 1, 980 }; 981 982 static struct iscsi_transport iscsi_sw_tcp_transport = { 983 .owner = THIS_MODULE, 984 .name = "tcp", 985 .caps = CAP_RECOVERY_L0 | CAP_MULTI_R2T | CAP_HDRDGST 986 | CAP_DATADGST, 987 /* session management */ 988 .create_session = iscsi_sw_tcp_session_create, 989 .destroy_session = iscsi_sw_tcp_session_destroy, 990 /* connection management */ 991 .create_conn = iscsi_sw_tcp_conn_create, 992 .bind_conn = iscsi_sw_tcp_conn_bind, 993 .destroy_conn = iscsi_sw_tcp_conn_destroy, 994 .attr_is_visible = iscsi_sw_tcp_attr_is_visible, 995 .set_param = iscsi_sw_tcp_conn_set_param, 996 .get_conn_param = iscsi_sw_tcp_conn_get_param, 997 .get_session_param = iscsi_session_get_param, 998 .start_conn = iscsi_conn_start, 999 .stop_conn = iscsi_sw_tcp_conn_stop, 1000 /* iscsi host params */ 1001 .get_host_param = iscsi_sw_tcp_host_get_param, 1002 .set_host_param = iscsi_host_set_param, 1003 /* IO */ 1004 .send_pdu = iscsi_conn_send_pdu, 1005 .get_stats = iscsi_sw_tcp_conn_get_stats, 1006 /* iscsi task/cmd helpers */ 1007 .init_task = iscsi_tcp_task_init, 1008 .xmit_task = iscsi_tcp_task_xmit, 1009 .cleanup_task = iscsi_tcp_cleanup_task, 1010 /* low level pdu helpers */ 1011 .xmit_pdu = iscsi_sw_tcp_pdu_xmit, 1012 .init_pdu = iscsi_sw_tcp_pdu_init, 1013 .alloc_pdu = iscsi_sw_tcp_pdu_alloc, 1014 /* recovery */ 1015 .session_recovery_timedout = iscsi_session_recovery_timedout, 1016 }; 1017 1018 static int __init iscsi_sw_tcp_init(void) 1019 { 1020 if (iscsi_max_lun < 1) { 1021 printk(KERN_ERR "iscsi_tcp: Invalid max_lun value of %u\n", 1022 iscsi_max_lun); 1023 return -EINVAL; 1024 } 1025 1026 iscsi_sw_tcp_scsi_transport = iscsi_register_transport( 1027 &iscsi_sw_tcp_transport); 1028 if (!iscsi_sw_tcp_scsi_transport) 1029 return -ENODEV; 1030 1031 return 0; 1032 } 1033 1034 static void __exit iscsi_sw_tcp_exit(void) 1035 { 1036 iscsi_unregister_transport(&iscsi_sw_tcp_transport); 1037 } 1038 1039 module_init(iscsi_sw_tcp_init); 1040 module_exit(iscsi_sw_tcp_exit); 1041