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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/file.h>
34#include <linux/blkdev.h>
35#include <linux/delay.h>
36#include <linux/kfifo.h>
37#include <linux/scatterlist.h>
38#include <linux/module.h>
39#include <net/tcp.h>
40#include <scsi/scsi_cmnd.h>
41#include <scsi/scsi_device.h>
42#include <scsi/scsi_host.h>
43#include <scsi/scsi.h>
44#include <scsi/scsi_transport_iscsi.h>
45
46#include "iscsi_tcp.h"
47
48MODULE_AUTHOR("Mike Christie <michaelc@cs.wisc.edu>, "
49 "Dmitry Yusupov <dmitry_yus@yahoo.com>, "
50 "Alex Aizman <itn780@yahoo.com>");
51MODULE_DESCRIPTION("iSCSI/TCP data-path");
52MODULE_LICENSE("GPL");
53
54static struct scsi_transport_template *iscsi_sw_tcp_scsi_transport;
55static struct scsi_host_template iscsi_sw_tcp_sht;
56static struct iscsi_transport iscsi_sw_tcp_transport;
57
58static unsigned int iscsi_max_lun = ~0;
59module_param_named(max_lun, iscsi_max_lun, uint, S_IRUGO);
60
61static int iscsi_sw_tcp_dbg;
62module_param_named(debug_iscsi_tcp, iscsi_sw_tcp_dbg, int,
63 S_IRUGO | S_IWUSR);
64MODULE_PARM_DESC(debug_iscsi_tcp, "Turn on debugging for iscsi_tcp module "
65 "Set to 1 to turn on, and zero to turn off. Default is off.");
66
67#define ISCSI_SW_TCP_DBG(_conn, dbg_fmt, arg...) \
68 do { \
69 if (iscsi_sw_tcp_dbg) \
70 iscsi_conn_printk(KERN_INFO, _conn, \
71 "%s " dbg_fmt, \
72 __func__, ##arg); \
73 } while (0);
74
75
76/**
77 * iscsi_sw_tcp_recv - TCP receive in sendfile fashion
78 * @rd_desc: read descriptor
79 * @skb: socket buffer
80 * @offset: offset in skb
81 * @len: skb->len - offset
82 */
83static int iscsi_sw_tcp_recv(read_descriptor_t *rd_desc, struct sk_buff *skb,
84 unsigned int offset, size_t len)
85{
86 struct iscsi_conn *conn = rd_desc->arg.data;
87 unsigned int consumed, total_consumed = 0;
88 int status;
89
90 ISCSI_SW_TCP_DBG(conn, "in %d bytes\n", skb->len - offset);
91
92 do {
93 status = 0;
94 consumed = iscsi_tcp_recv_skb(conn, skb, offset, 0, &status);
95 offset += consumed;
96 total_consumed += consumed;
97 } while (consumed != 0 && status != ISCSI_TCP_SKB_DONE);
98
99 ISCSI_SW_TCP_DBG(conn, "read %d bytes status %d\n",
100 skb->len - offset, status);
101 return total_consumed;
102}
103
104/**
105 * iscsi_sw_sk_state_check - check socket state
106 * @sk: socket
107 *
108 * If the socket is in CLOSE or CLOSE_WAIT we should
109 * not close the connection if there is still some
110 * data pending.
111 *
112 * Must be called with sk_callback_lock.
113 */
114static inline int iscsi_sw_sk_state_check(struct sock *sk)
115{
116 struct iscsi_conn *conn = sk->sk_user_data;
117
118 if ((sk->sk_state == TCP_CLOSE_WAIT || sk->sk_state == TCP_CLOSE) &&
119 (conn->session->state != ISCSI_STATE_LOGGING_OUT) &&
120 !atomic_read(&sk->sk_rmem_alloc)) {
121 ISCSI_SW_TCP_DBG(conn, "TCP_CLOSE|TCP_CLOSE_WAIT\n");
122 iscsi_conn_failure(conn, ISCSI_ERR_TCP_CONN_CLOSE);
123 return -ECONNRESET;
124 }
125 return 0;
126}
127
128static void iscsi_sw_tcp_data_ready(struct sock *sk)
129{
130 struct iscsi_conn *conn;
131 struct iscsi_tcp_conn *tcp_conn;
132 read_descriptor_t rd_desc;
133
134 read_lock(&sk->sk_callback_lock);
135 conn = sk->sk_user_data;
136 if (!conn) {
137 read_unlock(&sk->sk_callback_lock);
138 return;
139 }
140 tcp_conn = conn->dd_data;
141
142 /*
143 * Use rd_desc to pass 'conn' to iscsi_tcp_recv.
144 * We set count to 1 because we want the network layer to
145 * hand us all the skbs that are available. iscsi_tcp_recv
146 * handled pdus that cross buffers or pdus that still need data.
147 */
148 rd_desc.arg.data = conn;
149 rd_desc.count = 1;
150 tcp_read_sock(sk, &rd_desc, iscsi_sw_tcp_recv);
151
152 iscsi_sw_sk_state_check(sk);
153
154 /* If we had to (atomically) map a highmem page,
155 * unmap it now. */
156 iscsi_tcp_segment_unmap(&tcp_conn->in.segment);
157 read_unlock(&sk->sk_callback_lock);
158}
159
160static void iscsi_sw_tcp_state_change(struct sock *sk)
161{
162 struct iscsi_tcp_conn *tcp_conn;
163 struct iscsi_sw_tcp_conn *tcp_sw_conn;
164 struct iscsi_conn *conn;
165 struct iscsi_session *session;
166 void (*old_state_change)(struct sock *);
167
168 read_lock(&sk->sk_callback_lock);
169 conn = sk->sk_user_data;
170 if (!conn) {
171 read_unlock(&sk->sk_callback_lock);
172 return;
173 }
174 session = conn->session;
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(&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 **/
191static 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
216static 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
234static void
235iscsi_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 */
264static 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 **/
312static 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
351error:
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 */
362static inline int iscsi_sw_tcp_xmit_qlen(struct iscsi_conn *conn)
363{
364 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
365 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
366 struct iscsi_segment *segment = &tcp_sw_conn->out.segment;
367
368 return segment->total_copied - segment->total_size;
369}
370
371static int iscsi_sw_tcp_pdu_xmit(struct iscsi_task *task)
372{
373 struct iscsi_conn *conn = task->conn;
374 unsigned long pflags = current->flags;
375 int rc = 0;
376
377 current->flags |= PF_MEMALLOC;
378
379 while (iscsi_sw_tcp_xmit_qlen(conn)) {
380 rc = iscsi_sw_tcp_xmit(conn);
381 if (rc == 0) {
382 rc = -EAGAIN;
383 break;
384 }
385 if (rc < 0)
386 break;
387 rc = 0;
388 }
389
390 tsk_restore_flags(current, pflags, PF_MEMALLOC);
391 return rc;
392}
393
394/*
395 * This is called when we're done sending the header.
396 * Simply copy the data_segment to the send segment, and return.
397 */
398static int iscsi_sw_tcp_send_hdr_done(struct iscsi_tcp_conn *tcp_conn,
399 struct iscsi_segment *segment)
400{
401 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
402
403 tcp_sw_conn->out.segment = tcp_sw_conn->out.data_segment;
404 ISCSI_SW_TCP_DBG(tcp_conn->iscsi_conn,
405 "Header done. Next segment size %u total_size %u\n",
406 tcp_sw_conn->out.segment.size,
407 tcp_sw_conn->out.segment.total_size);
408 return 0;
409}
410
411static void iscsi_sw_tcp_send_hdr_prep(struct iscsi_conn *conn, void *hdr,
412 size_t hdrlen)
413{
414 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
415 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
416
417 ISCSI_SW_TCP_DBG(conn, "%s\n", conn->hdrdgst_en ?
418 "digest enabled" : "digest disabled");
419
420 /* Clear the data segment - needs to be filled in by the
421 * caller using iscsi_tcp_send_data_prep() */
422 memset(&tcp_sw_conn->out.data_segment, 0,
423 sizeof(struct iscsi_segment));
424
425 /* If header digest is enabled, compute the CRC and
426 * place the digest into the same buffer. We make
427 * sure that both iscsi_tcp_task and mtask have
428 * sufficient room.
429 */
430 if (conn->hdrdgst_en) {
431 iscsi_tcp_dgst_header(tcp_sw_conn->tx_hash, hdr, hdrlen,
432 hdr + hdrlen);
433 hdrlen += ISCSI_DIGEST_SIZE;
434 }
435
436 /* Remember header pointer for later, when we need
437 * to decide whether there's a payload to go along
438 * with the header. */
439 tcp_sw_conn->out.hdr = hdr;
440
441 iscsi_segment_init_linear(&tcp_sw_conn->out.segment, hdr, hdrlen,
442 iscsi_sw_tcp_send_hdr_done, NULL);
443}
444
445/*
446 * Prepare the send buffer for the payload data.
447 * Padding and checksumming will all be taken care
448 * of by the iscsi_segment routines.
449 */
450static int
451iscsi_sw_tcp_send_data_prep(struct iscsi_conn *conn, struct scatterlist *sg,
452 unsigned int count, unsigned int offset,
453 unsigned int len)
454{
455 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
456 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
457 struct ahash_request *tx_hash = NULL;
458 unsigned int hdr_spec_len;
459
460 ISCSI_SW_TCP_DBG(conn, "offset=%d, datalen=%d %s\n", offset, len,
461 conn->datadgst_en ?
462 "digest enabled" : "digest disabled");
463
464 /* Make sure the datalen matches what the caller
465 said he would send. */
466 hdr_spec_len = ntoh24(tcp_sw_conn->out.hdr->dlength);
467 WARN_ON(iscsi_padded(len) != iscsi_padded(hdr_spec_len));
468
469 if (conn->datadgst_en)
470 tx_hash = tcp_sw_conn->tx_hash;
471
472 return iscsi_segment_seek_sg(&tcp_sw_conn->out.data_segment,
473 sg, count, offset, len,
474 NULL, tx_hash);
475}
476
477static void
478iscsi_sw_tcp_send_linear_data_prep(struct iscsi_conn *conn, void *data,
479 size_t len)
480{
481 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
482 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
483 struct ahash_request *tx_hash = NULL;
484 unsigned int hdr_spec_len;
485
486 ISCSI_SW_TCP_DBG(conn, "datalen=%zd %s\n", len, conn->datadgst_en ?
487 "digest enabled" : "digest disabled");
488
489 /* Make sure the datalen matches what the caller
490 said he would send. */
491 hdr_spec_len = ntoh24(tcp_sw_conn->out.hdr->dlength);
492 WARN_ON(iscsi_padded(len) != iscsi_padded(hdr_spec_len));
493
494 if (conn->datadgst_en)
495 tx_hash = tcp_sw_conn->tx_hash;
496
497 iscsi_segment_init_linear(&tcp_sw_conn->out.data_segment,
498 data, len, NULL, tx_hash);
499}
500
501static int iscsi_sw_tcp_pdu_init(struct iscsi_task *task,
502 unsigned int offset, unsigned int count)
503{
504 struct iscsi_conn *conn = task->conn;
505 int err = 0;
506
507 iscsi_sw_tcp_send_hdr_prep(conn, task->hdr, task->hdr_len);
508
509 if (!count)
510 return 0;
511
512 if (!task->sc)
513 iscsi_sw_tcp_send_linear_data_prep(conn, task->data, count);
514 else {
515 struct scsi_data_buffer *sdb = scsi_out(task->sc);
516
517 err = iscsi_sw_tcp_send_data_prep(conn, sdb->table.sgl,
518 sdb->table.nents, offset,
519 count);
520 }
521
522 if (err) {
523 /* got invalid offset/len */
524 return -EIO;
525 }
526 return 0;
527}
528
529static int iscsi_sw_tcp_pdu_alloc(struct iscsi_task *task, uint8_t opcode)
530{
531 struct iscsi_tcp_task *tcp_task = task->dd_data;
532
533 task->hdr = task->dd_data + sizeof(*tcp_task);
534 task->hdr_max = sizeof(struct iscsi_sw_tcp_hdrbuf) - ISCSI_DIGEST_SIZE;
535 return 0;
536}
537
538static struct iscsi_cls_conn *
539iscsi_sw_tcp_conn_create(struct iscsi_cls_session *cls_session,
540 uint32_t conn_idx)
541{
542 struct iscsi_conn *conn;
543 struct iscsi_cls_conn *cls_conn;
544 struct iscsi_tcp_conn *tcp_conn;
545 struct iscsi_sw_tcp_conn *tcp_sw_conn;
546 struct crypto_ahash *tfm;
547
548 cls_conn = iscsi_tcp_conn_setup(cls_session, sizeof(*tcp_sw_conn),
549 conn_idx);
550 if (!cls_conn)
551 return NULL;
552 conn = cls_conn->dd_data;
553 tcp_conn = conn->dd_data;
554 tcp_sw_conn = tcp_conn->dd_data;
555
556 tfm = crypto_alloc_ahash("crc32c", 0, CRYPTO_ALG_ASYNC);
557 if (IS_ERR(tfm))
558 goto free_conn;
559
560 tcp_sw_conn->tx_hash = ahash_request_alloc(tfm, GFP_KERNEL);
561 if (!tcp_sw_conn->tx_hash)
562 goto free_tfm;
563 ahash_request_set_callback(tcp_sw_conn->tx_hash, 0, NULL, NULL);
564
565 tcp_sw_conn->rx_hash = ahash_request_alloc(tfm, GFP_KERNEL);
566 if (!tcp_sw_conn->rx_hash)
567 goto free_tx_hash;
568 ahash_request_set_callback(tcp_sw_conn->rx_hash, 0, NULL, NULL);
569
570 tcp_conn->rx_hash = tcp_sw_conn->rx_hash;
571
572 return cls_conn;
573
574free_tx_hash:
575 ahash_request_free(tcp_sw_conn->tx_hash);
576free_tfm:
577 crypto_free_ahash(tfm);
578free_conn:
579 iscsi_conn_printk(KERN_ERR, conn,
580 "Could not create connection due to crc32c "
581 "loading error. Make sure the crc32c "
582 "module is built as a module or into the "
583 "kernel\n");
584 iscsi_tcp_conn_teardown(cls_conn);
585 return NULL;
586}
587
588static void iscsi_sw_tcp_release_conn(struct iscsi_conn *conn)
589{
590 struct iscsi_session *session = conn->session;
591 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
592 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
593 struct socket *sock = tcp_sw_conn->sock;
594
595 if (!sock)
596 return;
597
598 sock_hold(sock->sk);
599 iscsi_sw_tcp_conn_restore_callbacks(conn);
600 sock_put(sock->sk);
601
602 spin_lock_bh(&session->frwd_lock);
603 tcp_sw_conn->sock = NULL;
604 spin_unlock_bh(&session->frwd_lock);
605 sockfd_put(sock);
606}
607
608static void iscsi_sw_tcp_conn_destroy(struct iscsi_cls_conn *cls_conn)
609{
610 struct iscsi_conn *conn = cls_conn->dd_data;
611 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
612 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
613
614 iscsi_sw_tcp_release_conn(conn);
615
616 ahash_request_free(tcp_sw_conn->rx_hash);
617 if (tcp_sw_conn->tx_hash) {
618 struct crypto_ahash *tfm;
619
620 tfm = crypto_ahash_reqtfm(tcp_sw_conn->tx_hash);
621 ahash_request_free(tcp_sw_conn->tx_hash);
622 crypto_free_ahash(tfm);
623 }
624
625 iscsi_tcp_conn_teardown(cls_conn);
626}
627
628static void iscsi_sw_tcp_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
629{
630 struct iscsi_conn *conn = cls_conn->dd_data;
631 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
632 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
633 struct socket *sock = tcp_sw_conn->sock;
634
635 /* userspace may have goofed up and not bound us */
636 if (!sock)
637 return;
638
639 sock->sk->sk_err = EIO;
640 wake_up_interruptible(sk_sleep(sock->sk));
641
642 /* stop xmit side */
643 iscsi_suspend_tx(conn);
644
645 /* stop recv side and release socket */
646 iscsi_sw_tcp_release_conn(conn);
647
648 iscsi_conn_stop(cls_conn, flag);
649}
650
651static int
652iscsi_sw_tcp_conn_bind(struct iscsi_cls_session *cls_session,
653 struct iscsi_cls_conn *cls_conn, uint64_t transport_eph,
654 int is_leading)
655{
656 struct iscsi_session *session = cls_session->dd_data;
657 struct iscsi_conn *conn = cls_conn->dd_data;
658 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
659 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
660 struct sock *sk;
661 struct socket *sock;
662 int err;
663
664 /* lookup for existing socket */
665 sock = sockfd_lookup((int)transport_eph, &err);
666 if (!sock) {
667 iscsi_conn_printk(KERN_ERR, conn,
668 "sockfd_lookup failed %d\n", err);
669 return -EEXIST;
670 }
671
672 err = iscsi_conn_bind(cls_session, cls_conn, is_leading);
673 if (err)
674 goto free_socket;
675
676 spin_lock_bh(&session->frwd_lock);
677 /* bind iSCSI connection and socket */
678 tcp_sw_conn->sock = sock;
679 spin_unlock_bh(&session->frwd_lock);
680
681 /* setup Socket parameters */
682 sk = sock->sk;
683 sk->sk_reuse = SK_CAN_REUSE;
684 sk->sk_sndtimeo = 15 * HZ; /* FIXME: make it configurable */
685 sk->sk_allocation = GFP_ATOMIC;
686 sk_set_memalloc(sk);
687
688 iscsi_sw_tcp_conn_set_callbacks(conn);
689 tcp_sw_conn->sendpage = tcp_sw_conn->sock->ops->sendpage;
690 /*
691 * set receive state machine into initial state
692 */
693 iscsi_tcp_hdr_recv_prep(tcp_conn);
694 return 0;
695
696free_socket:
697 sockfd_put(sock);
698 return err;
699}
700
701static int iscsi_sw_tcp_conn_set_param(struct iscsi_cls_conn *cls_conn,
702 enum iscsi_param param, char *buf,
703 int buflen)
704{
705 struct iscsi_conn *conn = cls_conn->dd_data;
706 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
707 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
708
709 switch(param) {
710 case ISCSI_PARAM_HDRDGST_EN:
711 iscsi_set_param(cls_conn, param, buf, buflen);
712 break;
713 case ISCSI_PARAM_DATADGST_EN:
714 iscsi_set_param(cls_conn, param, buf, buflen);
715 tcp_sw_conn->sendpage = conn->datadgst_en ?
716 sock_no_sendpage : tcp_sw_conn->sock->ops->sendpage;
717 break;
718 case ISCSI_PARAM_MAX_R2T:
719 return iscsi_tcp_set_max_r2t(conn, buf);
720 default:
721 return iscsi_set_param(cls_conn, param, buf, buflen);
722 }
723
724 return 0;
725}
726
727static int iscsi_sw_tcp_conn_get_param(struct iscsi_cls_conn *cls_conn,
728 enum iscsi_param param, char *buf)
729{
730 struct iscsi_conn *conn = cls_conn->dd_data;
731 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
732 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
733 struct sockaddr_in6 addr;
734 int rc, len;
735
736 switch(param) {
737 case ISCSI_PARAM_CONN_PORT:
738 case ISCSI_PARAM_CONN_ADDRESS:
739 case ISCSI_PARAM_LOCAL_PORT:
740 spin_lock_bh(&conn->session->frwd_lock);
741 if (!tcp_sw_conn || !tcp_sw_conn->sock) {
742 spin_unlock_bh(&conn->session->frwd_lock);
743 return -ENOTCONN;
744 }
745 if (param == ISCSI_PARAM_LOCAL_PORT)
746 rc = kernel_getsockname(tcp_sw_conn->sock,
747 (struct sockaddr *)&addr, &len);
748 else
749 rc = kernel_getpeername(tcp_sw_conn->sock,
750 (struct sockaddr *)&addr, &len);
751 spin_unlock_bh(&conn->session->frwd_lock);
752 if (rc)
753 return rc;
754
755 return iscsi_conn_get_addr_param((struct sockaddr_storage *)
756 &addr, param, buf);
757 default:
758 return iscsi_conn_get_param(cls_conn, param, buf);
759 }
760
761 return 0;
762}
763
764static int iscsi_sw_tcp_host_get_param(struct Scsi_Host *shost,
765 enum iscsi_host_param param, char *buf)
766{
767 struct iscsi_sw_tcp_host *tcp_sw_host = iscsi_host_priv(shost);
768 struct iscsi_session *session = tcp_sw_host->session;
769 struct iscsi_conn *conn;
770 struct iscsi_tcp_conn *tcp_conn;
771 struct iscsi_sw_tcp_conn *tcp_sw_conn;
772 struct sockaddr_in6 addr;
773 int rc, len;
774
775 switch (param) {
776 case ISCSI_HOST_PARAM_IPADDRESS:
777 if (!session)
778 return -ENOTCONN;
779
780 spin_lock_bh(&session->frwd_lock);
781 conn = session->leadconn;
782 if (!conn) {
783 spin_unlock_bh(&session->frwd_lock);
784 return -ENOTCONN;
785 }
786 tcp_conn = conn->dd_data;
787
788 tcp_sw_conn = tcp_conn->dd_data;
789 if (!tcp_sw_conn->sock) {
790 spin_unlock_bh(&session->frwd_lock);
791 return -ENOTCONN;
792 }
793
794 rc = kernel_getsockname(tcp_sw_conn->sock,
795 (struct sockaddr *)&addr, &len);
796 spin_unlock_bh(&session->frwd_lock);
797 if (rc)
798 return rc;
799
800 return iscsi_conn_get_addr_param((struct sockaddr_storage *)
801 &addr, param, buf);
802 default:
803 return iscsi_host_get_param(shost, param, buf);
804 }
805
806 return 0;
807}
808
809static void
810iscsi_sw_tcp_conn_get_stats(struct iscsi_cls_conn *cls_conn,
811 struct iscsi_stats *stats)
812{
813 struct iscsi_conn *conn = cls_conn->dd_data;
814 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
815 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
816
817 stats->custom_length = 3;
818 strcpy(stats->custom[0].desc, "tx_sendpage_failures");
819 stats->custom[0].value = tcp_sw_conn->sendpage_failures_cnt;
820 strcpy(stats->custom[1].desc, "rx_discontiguous_hdr");
821 stats->custom[1].value = tcp_sw_conn->discontiguous_hdr_cnt;
822 strcpy(stats->custom[2].desc, "eh_abort_cnt");
823 stats->custom[2].value = conn->eh_abort_cnt;
824
825 iscsi_tcp_conn_get_stats(cls_conn, stats);
826}
827
828static struct iscsi_cls_session *
829iscsi_sw_tcp_session_create(struct iscsi_endpoint *ep, uint16_t cmds_max,
830 uint16_t qdepth, uint32_t initial_cmdsn)
831{
832 struct iscsi_cls_session *cls_session;
833 struct iscsi_session *session;
834 struct iscsi_sw_tcp_host *tcp_sw_host;
835 struct Scsi_Host *shost;
836
837 if (ep) {
838 printk(KERN_ERR "iscsi_tcp: invalid ep %p.\n", ep);
839 return NULL;
840 }
841
842 shost = iscsi_host_alloc(&iscsi_sw_tcp_sht,
843 sizeof(struct iscsi_sw_tcp_host), 1);
844 if (!shost)
845 return NULL;
846 shost->transportt = iscsi_sw_tcp_scsi_transport;
847 shost->cmd_per_lun = qdepth;
848 shost->max_lun = iscsi_max_lun;
849 shost->max_id = 0;
850 shost->max_channel = 0;
851 shost->max_cmd_len = SCSI_MAX_VARLEN_CDB_SIZE;
852
853 if (iscsi_host_add(shost, NULL))
854 goto free_host;
855
856 cls_session = iscsi_session_setup(&iscsi_sw_tcp_transport, shost,
857 cmds_max, 0,
858 sizeof(struct iscsi_tcp_task) +
859 sizeof(struct iscsi_sw_tcp_hdrbuf),
860 initial_cmdsn, 0);
861 if (!cls_session)
862 goto remove_host;
863 session = cls_session->dd_data;
864 tcp_sw_host = iscsi_host_priv(shost);
865 tcp_sw_host->session = session;
866
867 shost->can_queue = session->scsi_cmds_max;
868 if (iscsi_tcp_r2tpool_alloc(session))
869 goto remove_session;
870 return cls_session;
871
872remove_session:
873 iscsi_session_teardown(cls_session);
874remove_host:
875 iscsi_host_remove(shost);
876free_host:
877 iscsi_host_free(shost);
878 return NULL;
879}
880
881static void iscsi_sw_tcp_session_destroy(struct iscsi_cls_session *cls_session)
882{
883 struct Scsi_Host *shost = iscsi_session_to_shost(cls_session);
884
885 iscsi_tcp_r2tpool_free(cls_session->dd_data);
886 iscsi_session_teardown(cls_session);
887
888 iscsi_host_remove(shost);
889 iscsi_host_free(shost);
890}
891
892static umode_t iscsi_sw_tcp_attr_is_visible(int param_type, int param)
893{
894 switch (param_type) {
895 case ISCSI_HOST_PARAM:
896 switch (param) {
897 case ISCSI_HOST_PARAM_NETDEV_NAME:
898 case ISCSI_HOST_PARAM_HWADDRESS:
899 case ISCSI_HOST_PARAM_IPADDRESS:
900 case ISCSI_HOST_PARAM_INITIATOR_NAME:
901 return S_IRUGO;
902 default:
903 return 0;
904 }
905 case ISCSI_PARAM:
906 switch (param) {
907 case ISCSI_PARAM_MAX_RECV_DLENGTH:
908 case ISCSI_PARAM_MAX_XMIT_DLENGTH:
909 case ISCSI_PARAM_HDRDGST_EN:
910 case ISCSI_PARAM_DATADGST_EN:
911 case ISCSI_PARAM_CONN_ADDRESS:
912 case ISCSI_PARAM_CONN_PORT:
913 case ISCSI_PARAM_LOCAL_PORT:
914 case ISCSI_PARAM_EXP_STATSN:
915 case ISCSI_PARAM_PERSISTENT_ADDRESS:
916 case ISCSI_PARAM_PERSISTENT_PORT:
917 case ISCSI_PARAM_PING_TMO:
918 case ISCSI_PARAM_RECV_TMO:
919 case ISCSI_PARAM_INITIAL_R2T_EN:
920 case ISCSI_PARAM_MAX_R2T:
921 case ISCSI_PARAM_IMM_DATA_EN:
922 case ISCSI_PARAM_FIRST_BURST:
923 case ISCSI_PARAM_MAX_BURST:
924 case ISCSI_PARAM_PDU_INORDER_EN:
925 case ISCSI_PARAM_DATASEQ_INORDER_EN:
926 case ISCSI_PARAM_ERL:
927 case ISCSI_PARAM_TARGET_NAME:
928 case ISCSI_PARAM_TPGT:
929 case ISCSI_PARAM_USERNAME:
930 case ISCSI_PARAM_PASSWORD:
931 case ISCSI_PARAM_USERNAME_IN:
932 case ISCSI_PARAM_PASSWORD_IN:
933 case ISCSI_PARAM_FAST_ABORT:
934 case ISCSI_PARAM_ABORT_TMO:
935 case ISCSI_PARAM_LU_RESET_TMO:
936 case ISCSI_PARAM_TGT_RESET_TMO:
937 case ISCSI_PARAM_IFACE_NAME:
938 case ISCSI_PARAM_INITIATOR_NAME:
939 return S_IRUGO;
940 default:
941 return 0;
942 }
943 }
944
945 return 0;
946}
947
948static int iscsi_sw_tcp_slave_alloc(struct scsi_device *sdev)
949{
950 set_bit(QUEUE_FLAG_BIDI, &sdev->request_queue->queue_flags);
951 return 0;
952}
953
954static int iscsi_sw_tcp_slave_configure(struct scsi_device *sdev)
955{
956 blk_queue_bounce_limit(sdev->request_queue, BLK_BOUNCE_ANY);
957 blk_queue_dma_alignment(sdev->request_queue, 0);
958 return 0;
959}
960
961static struct scsi_host_template iscsi_sw_tcp_sht = {
962 .module = THIS_MODULE,
963 .name = "iSCSI Initiator over TCP/IP",
964 .queuecommand = iscsi_queuecommand,
965 .change_queue_depth = scsi_change_queue_depth,
966 .can_queue = ISCSI_DEF_XMIT_CMDS_MAX - 1,
967 .sg_tablesize = 4096,
968 .max_sectors = 0xFFFF,
969 .cmd_per_lun = ISCSI_DEF_CMD_PER_LUN,
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
982static 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
1018static 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
1034static void __exit iscsi_sw_tcp_exit(void)
1035{
1036 iscsi_unregister_transport(&iscsi_sw_tcp_transport);
1037}
1038
1039module_init(iscsi_sw_tcp_init);
1040module_exit(iscsi_sw_tcp_exit);
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * iSCSI Initiator over TCP/IP Data-Path
4 *
5 * Copyright (C) 2004 Dmitry Yusupov
6 * Copyright (C) 2004 Alex Aizman
7 * Copyright (C) 2005 - 2006 Mike Christie
8 * Copyright (C) 2006 Red Hat, Inc. All rights reserved.
9 * maintained by open-iscsi@googlegroups.com
10 *
11 * See the file COPYING included with this distribution for more details.
12 *
13 * Credits:
14 * Christoph Hellwig
15 * FUJITA Tomonori
16 * Arne Redlich
17 * Zhenyu Wang
18 */
19
20#include <crypto/hash.h>
21#include <linux/types.h>
22#include <linux/inet.h>
23#include <linux/slab.h>
24#include <linux/sched/mm.h>
25#include <linux/file.h>
26#include <linux/blkdev.h>
27#include <linux/delay.h>
28#include <linux/kfifo.h>
29#include <linux/scatterlist.h>
30#include <linux/module.h>
31#include <linux/backing-dev.h>
32#include <net/tcp.h>
33#include <scsi/scsi_cmnd.h>
34#include <scsi/scsi_device.h>
35#include <scsi/scsi_host.h>
36#include <scsi/scsi.h>
37#include <scsi/scsi_transport_iscsi.h>
38#include <trace/events/iscsi.h>
39
40#include "iscsi_tcp.h"
41
42MODULE_AUTHOR("Mike Christie <michaelc@cs.wisc.edu>, "
43 "Dmitry Yusupov <dmitry_yus@yahoo.com>, "
44 "Alex Aizman <itn780@yahoo.com>");
45MODULE_DESCRIPTION("iSCSI/TCP data-path");
46MODULE_LICENSE("GPL");
47
48static struct scsi_transport_template *iscsi_sw_tcp_scsi_transport;
49static struct scsi_host_template iscsi_sw_tcp_sht;
50static struct iscsi_transport iscsi_sw_tcp_transport;
51
52static unsigned int iscsi_max_lun = ~0;
53module_param_named(max_lun, iscsi_max_lun, uint, S_IRUGO);
54
55static int iscsi_sw_tcp_dbg;
56module_param_named(debug_iscsi_tcp, iscsi_sw_tcp_dbg, int,
57 S_IRUGO | S_IWUSR);
58MODULE_PARM_DESC(debug_iscsi_tcp, "Turn on debugging for iscsi_tcp module "
59 "Set to 1 to turn on, and zero to turn off. Default is off.");
60
61#define ISCSI_SW_TCP_DBG(_conn, dbg_fmt, arg...) \
62 do { \
63 if (iscsi_sw_tcp_dbg) \
64 iscsi_conn_printk(KERN_INFO, _conn, \
65 "%s " dbg_fmt, \
66 __func__, ##arg); \
67 iscsi_dbg_trace(trace_iscsi_dbg_sw_tcp, \
68 &(_conn)->cls_conn->dev, \
69 "%s " dbg_fmt, __func__, ##arg);\
70 } while (0);
71
72
73/**
74 * iscsi_sw_tcp_recv - TCP receive in sendfile fashion
75 * @rd_desc: read descriptor
76 * @skb: socket buffer
77 * @offset: offset in skb
78 * @len: skb->len - offset
79 */
80static int iscsi_sw_tcp_recv(read_descriptor_t *rd_desc, struct sk_buff *skb,
81 unsigned int offset, size_t len)
82{
83 struct iscsi_conn *conn = rd_desc->arg.data;
84 unsigned int consumed, total_consumed = 0;
85 int status;
86
87 ISCSI_SW_TCP_DBG(conn, "in %d bytes\n", skb->len - offset);
88
89 do {
90 status = 0;
91 consumed = iscsi_tcp_recv_skb(conn, skb, offset, 0, &status);
92 offset += consumed;
93 total_consumed += consumed;
94 } while (consumed != 0 && status != ISCSI_TCP_SKB_DONE);
95
96 ISCSI_SW_TCP_DBG(conn, "read %d bytes status %d\n",
97 skb->len - offset, status);
98 return total_consumed;
99}
100
101/**
102 * iscsi_sw_sk_state_check - check socket state
103 * @sk: socket
104 *
105 * If the socket is in CLOSE or CLOSE_WAIT we should
106 * not close the connection if there is still some
107 * data pending.
108 *
109 * Must be called with sk_callback_lock.
110 */
111static inline int iscsi_sw_sk_state_check(struct sock *sk)
112{
113 struct iscsi_conn *conn = sk->sk_user_data;
114
115 if ((sk->sk_state == TCP_CLOSE_WAIT || sk->sk_state == TCP_CLOSE) &&
116 (conn->session->state != ISCSI_STATE_LOGGING_OUT) &&
117 !atomic_read(&sk->sk_rmem_alloc)) {
118 ISCSI_SW_TCP_DBG(conn, "TCP_CLOSE|TCP_CLOSE_WAIT\n");
119 iscsi_conn_failure(conn, ISCSI_ERR_TCP_CONN_CLOSE);
120 return -ECONNRESET;
121 }
122 return 0;
123}
124
125static void iscsi_sw_tcp_data_ready(struct sock *sk)
126{
127 struct iscsi_conn *conn;
128 struct iscsi_tcp_conn *tcp_conn;
129 read_descriptor_t rd_desc;
130
131 read_lock_bh(&sk->sk_callback_lock);
132 conn = sk->sk_user_data;
133 if (!conn) {
134 read_unlock_bh(&sk->sk_callback_lock);
135 return;
136 }
137 tcp_conn = conn->dd_data;
138
139 /*
140 * Use rd_desc to pass 'conn' to iscsi_tcp_recv.
141 * We set count to 1 because we want the network layer to
142 * hand us all the skbs that are available. iscsi_tcp_recv
143 * handled pdus that cross buffers or pdus that still need data.
144 */
145 rd_desc.arg.data = conn;
146 rd_desc.count = 1;
147 tcp_read_sock(sk, &rd_desc, iscsi_sw_tcp_recv);
148
149 iscsi_sw_sk_state_check(sk);
150
151 /* If we had to (atomically) map a highmem page,
152 * unmap it now. */
153 iscsi_tcp_segment_unmap(&tcp_conn->in.segment);
154 read_unlock_bh(&sk->sk_callback_lock);
155}
156
157static void iscsi_sw_tcp_state_change(struct sock *sk)
158{
159 struct iscsi_tcp_conn *tcp_conn;
160 struct iscsi_sw_tcp_conn *tcp_sw_conn;
161 struct iscsi_conn *conn;
162 void (*old_state_change)(struct sock *);
163
164 read_lock_bh(&sk->sk_callback_lock);
165 conn = sk->sk_user_data;
166 if (!conn) {
167 read_unlock_bh(&sk->sk_callback_lock);
168 return;
169 }
170
171 iscsi_sw_sk_state_check(sk);
172
173 tcp_conn = conn->dd_data;
174 tcp_sw_conn = tcp_conn->dd_data;
175 old_state_change = tcp_sw_conn->old_state_change;
176
177 read_unlock_bh(&sk->sk_callback_lock);
178
179 old_state_change(sk);
180}
181
182/**
183 * iscsi_write_space - Called when more output buffer space is available
184 * @sk: socket space is available for
185 **/
186static void iscsi_sw_tcp_write_space(struct sock *sk)
187{
188 struct iscsi_conn *conn;
189 struct iscsi_tcp_conn *tcp_conn;
190 struct iscsi_sw_tcp_conn *tcp_sw_conn;
191 void (*old_write_space)(struct sock *);
192
193 read_lock_bh(&sk->sk_callback_lock);
194 conn = sk->sk_user_data;
195 if (!conn) {
196 read_unlock_bh(&sk->sk_callback_lock);
197 return;
198 }
199
200 tcp_conn = conn->dd_data;
201 tcp_sw_conn = tcp_conn->dd_data;
202 old_write_space = tcp_sw_conn->old_write_space;
203 read_unlock_bh(&sk->sk_callback_lock);
204
205 old_write_space(sk);
206
207 ISCSI_SW_TCP_DBG(conn, "iscsi_write_space\n");
208 iscsi_conn_queue_work(conn);
209}
210
211static void iscsi_sw_tcp_conn_set_callbacks(struct iscsi_conn *conn)
212{
213 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
214 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
215 struct sock *sk = tcp_sw_conn->sock->sk;
216
217 /* assign new callbacks */
218 write_lock_bh(&sk->sk_callback_lock);
219 sk->sk_user_data = conn;
220 tcp_sw_conn->old_data_ready = sk->sk_data_ready;
221 tcp_sw_conn->old_state_change = sk->sk_state_change;
222 tcp_sw_conn->old_write_space = sk->sk_write_space;
223 sk->sk_data_ready = iscsi_sw_tcp_data_ready;
224 sk->sk_state_change = iscsi_sw_tcp_state_change;
225 sk->sk_write_space = iscsi_sw_tcp_write_space;
226 write_unlock_bh(&sk->sk_callback_lock);
227}
228
229static void
230iscsi_sw_tcp_conn_restore_callbacks(struct iscsi_conn *conn)
231{
232 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
233 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
234 struct sock *sk = tcp_sw_conn->sock->sk;
235
236 /* restore socket callbacks, see also: iscsi_conn_set_callbacks() */
237 write_lock_bh(&sk->sk_callback_lock);
238 sk->sk_user_data = NULL;
239 sk->sk_data_ready = tcp_sw_conn->old_data_ready;
240 sk->sk_state_change = tcp_sw_conn->old_state_change;
241 sk->sk_write_space = tcp_sw_conn->old_write_space;
242 sk->sk_no_check_tx = 0;
243 write_unlock_bh(&sk->sk_callback_lock);
244}
245
246/**
247 * iscsi_sw_tcp_xmit_segment - transmit segment
248 * @tcp_conn: the iSCSI TCP connection
249 * @segment: the buffer to transmnit
250 *
251 * This function transmits as much of the buffer as
252 * the network layer will accept, and returns the number of
253 * bytes transmitted.
254 *
255 * If CRC hashing is enabled, the function will compute the
256 * hash as it goes. When the entire segment has been transmitted,
257 * it will retrieve the hash value and send it as well.
258 */
259static int iscsi_sw_tcp_xmit_segment(struct iscsi_tcp_conn *tcp_conn,
260 struct iscsi_segment *segment)
261{
262 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
263 struct socket *sk = tcp_sw_conn->sock;
264 unsigned int copied = 0;
265 int r = 0;
266
267 while (!iscsi_tcp_segment_done(tcp_conn, segment, 0, r)) {
268 struct scatterlist *sg;
269 unsigned int offset, copy;
270 int flags = 0;
271
272 r = 0;
273 offset = segment->copied;
274 copy = segment->size - offset;
275
276 if (segment->total_copied + segment->size < segment->total_size)
277 flags |= MSG_MORE;
278
279 /* Use sendpage if we can; else fall back to sendmsg */
280 if (!segment->data) {
281 sg = segment->sg;
282 offset += segment->sg_offset + sg->offset;
283 r = tcp_sw_conn->sendpage(sk, sg_page(sg), offset,
284 copy, flags);
285 } else {
286 struct msghdr msg = { .msg_flags = flags };
287 struct kvec iov = {
288 .iov_base = segment->data + offset,
289 .iov_len = copy
290 };
291
292 r = kernel_sendmsg(sk, &msg, &iov, 1, copy);
293 }
294
295 if (r < 0) {
296 iscsi_tcp_segment_unmap(segment);
297 return r;
298 }
299 copied += r;
300 }
301 return copied;
302}
303
304/**
305 * iscsi_sw_tcp_xmit - TCP transmit
306 * @conn: iscsi connection
307 **/
308static int iscsi_sw_tcp_xmit(struct iscsi_conn *conn)
309{
310 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
311 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
312 struct iscsi_segment *segment = &tcp_sw_conn->out.segment;
313 unsigned int consumed = 0;
314 int rc = 0;
315
316 while (1) {
317 rc = iscsi_sw_tcp_xmit_segment(tcp_conn, segment);
318 /*
319 * We may not have been able to send data because the conn
320 * is getting stopped. libiscsi will know so propagate err
321 * for it to do the right thing.
322 */
323 if (rc == -EAGAIN)
324 return rc;
325 else if (rc < 0) {
326 rc = ISCSI_ERR_XMIT_FAILED;
327 goto error;
328 } else if (rc == 0)
329 break;
330
331 consumed += rc;
332
333 if (segment->total_copied >= segment->total_size) {
334 if (segment->done != NULL) {
335 rc = segment->done(tcp_conn, segment);
336 if (rc != 0)
337 goto error;
338 }
339 }
340 }
341
342 ISCSI_SW_TCP_DBG(conn, "xmit %d bytes\n", consumed);
343
344 conn->txdata_octets += consumed;
345 return consumed;
346
347error:
348 /* Transmit error. We could initiate error recovery
349 * here. */
350 ISCSI_SW_TCP_DBG(conn, "Error sending PDU, errno=%d\n", rc);
351 iscsi_conn_failure(conn, rc);
352 return -EIO;
353}
354
355/**
356 * iscsi_tcp_xmit_qlen - return the number of bytes queued for xmit
357 * @conn: iscsi connection
358 */
359static inline int iscsi_sw_tcp_xmit_qlen(struct iscsi_conn *conn)
360{
361 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
362 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
363 struct iscsi_segment *segment = &tcp_sw_conn->out.segment;
364
365 return segment->total_copied - segment->total_size;
366}
367
368static int iscsi_sw_tcp_pdu_xmit(struct iscsi_task *task)
369{
370 struct iscsi_conn *conn = task->conn;
371 unsigned int noreclaim_flag;
372 int rc = 0;
373
374 noreclaim_flag = memalloc_noreclaim_save();
375
376 while (iscsi_sw_tcp_xmit_qlen(conn)) {
377 rc = iscsi_sw_tcp_xmit(conn);
378 if (rc == 0) {
379 rc = -EAGAIN;
380 break;
381 }
382 if (rc < 0)
383 break;
384 rc = 0;
385 }
386
387 memalloc_noreclaim_restore(noreclaim_flag);
388 return rc;
389}
390
391/*
392 * This is called when we're done sending the header.
393 * Simply copy the data_segment to the send segment, and return.
394 */
395static int iscsi_sw_tcp_send_hdr_done(struct iscsi_tcp_conn *tcp_conn,
396 struct iscsi_segment *segment)
397{
398 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
399
400 tcp_sw_conn->out.segment = tcp_sw_conn->out.data_segment;
401 ISCSI_SW_TCP_DBG(tcp_conn->iscsi_conn,
402 "Header done. Next segment size %u total_size %u\n",
403 tcp_sw_conn->out.segment.size,
404 tcp_sw_conn->out.segment.total_size);
405 return 0;
406}
407
408static void iscsi_sw_tcp_send_hdr_prep(struct iscsi_conn *conn, void *hdr,
409 size_t hdrlen)
410{
411 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
412 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
413
414 ISCSI_SW_TCP_DBG(conn, "%s\n", conn->hdrdgst_en ?
415 "digest enabled" : "digest disabled");
416
417 /* Clear the data segment - needs to be filled in by the
418 * caller using iscsi_tcp_send_data_prep() */
419 memset(&tcp_sw_conn->out.data_segment, 0,
420 sizeof(struct iscsi_segment));
421
422 /* If header digest is enabled, compute the CRC and
423 * place the digest into the same buffer. We make
424 * sure that both iscsi_tcp_task and mtask have
425 * sufficient room.
426 */
427 if (conn->hdrdgst_en) {
428 iscsi_tcp_dgst_header(tcp_sw_conn->tx_hash, hdr, hdrlen,
429 hdr + hdrlen);
430 hdrlen += ISCSI_DIGEST_SIZE;
431 }
432
433 /* Remember header pointer for later, when we need
434 * to decide whether there's a payload to go along
435 * with the header. */
436 tcp_sw_conn->out.hdr = hdr;
437
438 iscsi_segment_init_linear(&tcp_sw_conn->out.segment, hdr, hdrlen,
439 iscsi_sw_tcp_send_hdr_done, NULL);
440}
441
442/*
443 * Prepare the send buffer for the payload data.
444 * Padding and checksumming will all be taken care
445 * of by the iscsi_segment routines.
446 */
447static int
448iscsi_sw_tcp_send_data_prep(struct iscsi_conn *conn, struct scatterlist *sg,
449 unsigned int count, unsigned int offset,
450 unsigned int len)
451{
452 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
453 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
454 struct ahash_request *tx_hash = NULL;
455 unsigned int hdr_spec_len;
456
457 ISCSI_SW_TCP_DBG(conn, "offset=%d, datalen=%d %s\n", offset, len,
458 conn->datadgst_en ?
459 "digest enabled" : "digest disabled");
460
461 /* Make sure the datalen matches what the caller
462 said he would send. */
463 hdr_spec_len = ntoh24(tcp_sw_conn->out.hdr->dlength);
464 WARN_ON(iscsi_padded(len) != iscsi_padded(hdr_spec_len));
465
466 if (conn->datadgst_en)
467 tx_hash = tcp_sw_conn->tx_hash;
468
469 return iscsi_segment_seek_sg(&tcp_sw_conn->out.data_segment,
470 sg, count, offset, len,
471 NULL, tx_hash);
472}
473
474static void
475iscsi_sw_tcp_send_linear_data_prep(struct iscsi_conn *conn, void *data,
476 size_t len)
477{
478 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
479 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
480 struct ahash_request *tx_hash = NULL;
481 unsigned int hdr_spec_len;
482
483 ISCSI_SW_TCP_DBG(conn, "datalen=%zd %s\n", len, conn->datadgst_en ?
484 "digest enabled" : "digest disabled");
485
486 /* Make sure the datalen matches what the caller
487 said he would send. */
488 hdr_spec_len = ntoh24(tcp_sw_conn->out.hdr->dlength);
489 WARN_ON(iscsi_padded(len) != iscsi_padded(hdr_spec_len));
490
491 if (conn->datadgst_en)
492 tx_hash = tcp_sw_conn->tx_hash;
493
494 iscsi_segment_init_linear(&tcp_sw_conn->out.data_segment,
495 data, len, NULL, tx_hash);
496}
497
498static int iscsi_sw_tcp_pdu_init(struct iscsi_task *task,
499 unsigned int offset, unsigned int count)
500{
501 struct iscsi_conn *conn = task->conn;
502 int err = 0;
503
504 iscsi_sw_tcp_send_hdr_prep(conn, task->hdr, task->hdr_len);
505
506 if (!count)
507 return 0;
508
509 if (!task->sc)
510 iscsi_sw_tcp_send_linear_data_prep(conn, task->data, count);
511 else {
512 struct scsi_data_buffer *sdb = &task->sc->sdb;
513
514 err = iscsi_sw_tcp_send_data_prep(conn, sdb->table.sgl,
515 sdb->table.nents, offset,
516 count);
517 }
518
519 if (err) {
520 /* got invalid offset/len */
521 return -EIO;
522 }
523 return 0;
524}
525
526static int iscsi_sw_tcp_pdu_alloc(struct iscsi_task *task, uint8_t opcode)
527{
528 struct iscsi_tcp_task *tcp_task = task->dd_data;
529
530 task->hdr = task->dd_data + sizeof(*tcp_task);
531 task->hdr_max = sizeof(struct iscsi_sw_tcp_hdrbuf) - ISCSI_DIGEST_SIZE;
532 return 0;
533}
534
535static struct iscsi_cls_conn *
536iscsi_sw_tcp_conn_create(struct iscsi_cls_session *cls_session,
537 uint32_t conn_idx)
538{
539 struct iscsi_conn *conn;
540 struct iscsi_cls_conn *cls_conn;
541 struct iscsi_tcp_conn *tcp_conn;
542 struct iscsi_sw_tcp_conn *tcp_sw_conn;
543 struct crypto_ahash *tfm;
544
545 cls_conn = iscsi_tcp_conn_setup(cls_session, sizeof(*tcp_sw_conn),
546 conn_idx);
547 if (!cls_conn)
548 return NULL;
549 conn = cls_conn->dd_data;
550 tcp_conn = conn->dd_data;
551 tcp_sw_conn = tcp_conn->dd_data;
552
553 tfm = crypto_alloc_ahash("crc32c", 0, CRYPTO_ALG_ASYNC);
554 if (IS_ERR(tfm))
555 goto free_conn;
556
557 tcp_sw_conn->tx_hash = ahash_request_alloc(tfm, GFP_KERNEL);
558 if (!tcp_sw_conn->tx_hash)
559 goto free_tfm;
560 ahash_request_set_callback(tcp_sw_conn->tx_hash, 0, NULL, NULL);
561
562 tcp_sw_conn->rx_hash = ahash_request_alloc(tfm, GFP_KERNEL);
563 if (!tcp_sw_conn->rx_hash)
564 goto free_tx_hash;
565 ahash_request_set_callback(tcp_sw_conn->rx_hash, 0, NULL, NULL);
566
567 tcp_conn->rx_hash = tcp_sw_conn->rx_hash;
568
569 return cls_conn;
570
571free_tx_hash:
572 ahash_request_free(tcp_sw_conn->tx_hash);
573free_tfm:
574 crypto_free_ahash(tfm);
575free_conn:
576 iscsi_conn_printk(KERN_ERR, conn,
577 "Could not create connection due to crc32c "
578 "loading error. Make sure the crc32c "
579 "module is built as a module or into the "
580 "kernel\n");
581 iscsi_tcp_conn_teardown(cls_conn);
582 return NULL;
583}
584
585static void iscsi_sw_tcp_release_conn(struct iscsi_conn *conn)
586{
587 struct iscsi_session *session = conn->session;
588 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
589 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
590 struct socket *sock = tcp_sw_conn->sock;
591
592 if (!sock)
593 return;
594
595 sock_hold(sock->sk);
596 iscsi_sw_tcp_conn_restore_callbacks(conn);
597 sock_put(sock->sk);
598
599 spin_lock_bh(&session->frwd_lock);
600 tcp_sw_conn->sock = NULL;
601 spin_unlock_bh(&session->frwd_lock);
602 sockfd_put(sock);
603}
604
605static void iscsi_sw_tcp_conn_destroy(struct iscsi_cls_conn *cls_conn)
606{
607 struct iscsi_conn *conn = cls_conn->dd_data;
608 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
609 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
610
611 iscsi_sw_tcp_release_conn(conn);
612
613 ahash_request_free(tcp_sw_conn->rx_hash);
614 if (tcp_sw_conn->tx_hash) {
615 struct crypto_ahash *tfm;
616
617 tfm = crypto_ahash_reqtfm(tcp_sw_conn->tx_hash);
618 ahash_request_free(tcp_sw_conn->tx_hash);
619 crypto_free_ahash(tfm);
620 }
621
622 iscsi_tcp_conn_teardown(cls_conn);
623}
624
625static void iscsi_sw_tcp_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
626{
627 struct iscsi_conn *conn = cls_conn->dd_data;
628 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
629 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
630 struct socket *sock = tcp_sw_conn->sock;
631
632 /* userspace may have goofed up and not bound us */
633 if (!sock)
634 return;
635
636 sock->sk->sk_err = EIO;
637 wake_up_interruptible(sk_sleep(sock->sk));
638
639 /* stop xmit side */
640 iscsi_suspend_tx(conn);
641
642 /* stop recv side and release socket */
643 iscsi_sw_tcp_release_conn(conn);
644
645 iscsi_conn_stop(cls_conn, flag);
646}
647
648static int
649iscsi_sw_tcp_conn_bind(struct iscsi_cls_session *cls_session,
650 struct iscsi_cls_conn *cls_conn, uint64_t transport_eph,
651 int is_leading)
652{
653 struct iscsi_session *session = cls_session->dd_data;
654 struct iscsi_conn *conn = cls_conn->dd_data;
655 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
656 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
657 struct sock *sk;
658 struct socket *sock;
659 int err;
660
661 /* lookup for existing socket */
662 sock = sockfd_lookup((int)transport_eph, &err);
663 if (!sock) {
664 iscsi_conn_printk(KERN_ERR, conn,
665 "sockfd_lookup failed %d\n", err);
666 return -EEXIST;
667 }
668
669 err = iscsi_conn_bind(cls_session, cls_conn, is_leading);
670 if (err)
671 goto free_socket;
672
673 spin_lock_bh(&session->frwd_lock);
674 /* bind iSCSI connection and socket */
675 tcp_sw_conn->sock = sock;
676 spin_unlock_bh(&session->frwd_lock);
677
678 /* setup Socket parameters */
679 sk = sock->sk;
680 sk->sk_reuse = SK_CAN_REUSE;
681 sk->sk_sndtimeo = 15 * HZ; /* FIXME: make it configurable */
682 sk->sk_allocation = GFP_ATOMIC;
683 sk_set_memalloc(sk);
684
685 iscsi_sw_tcp_conn_set_callbacks(conn);
686 tcp_sw_conn->sendpage = tcp_sw_conn->sock->ops->sendpage;
687 /*
688 * set receive state machine into initial state
689 */
690 iscsi_tcp_hdr_recv_prep(tcp_conn);
691 return 0;
692
693free_socket:
694 sockfd_put(sock);
695 return err;
696}
697
698static int iscsi_sw_tcp_conn_set_param(struct iscsi_cls_conn *cls_conn,
699 enum iscsi_param param, char *buf,
700 int buflen)
701{
702 struct iscsi_conn *conn = cls_conn->dd_data;
703 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
704 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
705
706 switch(param) {
707 case ISCSI_PARAM_HDRDGST_EN:
708 iscsi_set_param(cls_conn, param, buf, buflen);
709 break;
710 case ISCSI_PARAM_DATADGST_EN:
711 iscsi_set_param(cls_conn, param, buf, buflen);
712 tcp_sw_conn->sendpage = conn->datadgst_en ?
713 sock_no_sendpage : tcp_sw_conn->sock->ops->sendpage;
714 break;
715 case ISCSI_PARAM_MAX_R2T:
716 return iscsi_tcp_set_max_r2t(conn, buf);
717 default:
718 return iscsi_set_param(cls_conn, param, buf, buflen);
719 }
720
721 return 0;
722}
723
724static int iscsi_sw_tcp_conn_get_param(struct iscsi_cls_conn *cls_conn,
725 enum iscsi_param param, char *buf)
726{
727 struct iscsi_conn *conn = cls_conn->dd_data;
728 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
729 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
730 struct sockaddr_in6 addr;
731 int rc;
732
733 switch(param) {
734 case ISCSI_PARAM_CONN_PORT:
735 case ISCSI_PARAM_CONN_ADDRESS:
736 case ISCSI_PARAM_LOCAL_PORT:
737 spin_lock_bh(&conn->session->frwd_lock);
738 if (!tcp_sw_conn || !tcp_sw_conn->sock) {
739 spin_unlock_bh(&conn->session->frwd_lock);
740 return -ENOTCONN;
741 }
742 if (param == ISCSI_PARAM_LOCAL_PORT)
743 rc = kernel_getsockname(tcp_sw_conn->sock,
744 (struct sockaddr *)&addr);
745 else
746 rc = kernel_getpeername(tcp_sw_conn->sock,
747 (struct sockaddr *)&addr);
748 spin_unlock_bh(&conn->session->frwd_lock);
749 if (rc < 0)
750 return rc;
751
752 return iscsi_conn_get_addr_param((struct sockaddr_storage *)
753 &addr, param, buf);
754 default:
755 return iscsi_conn_get_param(cls_conn, param, buf);
756 }
757
758 return 0;
759}
760
761static int iscsi_sw_tcp_host_get_param(struct Scsi_Host *shost,
762 enum iscsi_host_param param, char *buf)
763{
764 struct iscsi_sw_tcp_host *tcp_sw_host = iscsi_host_priv(shost);
765 struct iscsi_session *session = tcp_sw_host->session;
766 struct iscsi_conn *conn;
767 struct iscsi_tcp_conn *tcp_conn;
768 struct iscsi_sw_tcp_conn *tcp_sw_conn;
769 struct sockaddr_in6 addr;
770 int rc;
771
772 switch (param) {
773 case ISCSI_HOST_PARAM_IPADDRESS:
774 if (!session)
775 return -ENOTCONN;
776
777 spin_lock_bh(&session->frwd_lock);
778 conn = session->leadconn;
779 if (!conn) {
780 spin_unlock_bh(&session->frwd_lock);
781 return -ENOTCONN;
782 }
783 tcp_conn = conn->dd_data;
784
785 tcp_sw_conn = tcp_conn->dd_data;
786 if (!tcp_sw_conn->sock) {
787 spin_unlock_bh(&session->frwd_lock);
788 return -ENOTCONN;
789 }
790
791 rc = kernel_getsockname(tcp_sw_conn->sock,
792 (struct sockaddr *)&addr);
793 spin_unlock_bh(&session->frwd_lock);
794 if (rc < 0)
795 return rc;
796
797 return iscsi_conn_get_addr_param((struct sockaddr_storage *)
798 &addr,
799 (enum iscsi_param)param, buf);
800 default:
801 return iscsi_host_get_param(shost, param, buf);
802 }
803
804 return 0;
805}
806
807static void
808iscsi_sw_tcp_conn_get_stats(struct iscsi_cls_conn *cls_conn,
809 struct iscsi_stats *stats)
810{
811 struct iscsi_conn *conn = cls_conn->dd_data;
812 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
813 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
814
815 stats->custom_length = 3;
816 strcpy(stats->custom[0].desc, "tx_sendpage_failures");
817 stats->custom[0].value = tcp_sw_conn->sendpage_failures_cnt;
818 strcpy(stats->custom[1].desc, "rx_discontiguous_hdr");
819 stats->custom[1].value = tcp_sw_conn->discontiguous_hdr_cnt;
820 strcpy(stats->custom[2].desc, "eh_abort_cnt");
821 stats->custom[2].value = conn->eh_abort_cnt;
822
823 iscsi_tcp_conn_get_stats(cls_conn, stats);
824}
825
826static struct iscsi_cls_session *
827iscsi_sw_tcp_session_create(struct iscsi_endpoint *ep, uint16_t cmds_max,
828 uint16_t qdepth, uint32_t initial_cmdsn)
829{
830 struct iscsi_cls_session *cls_session;
831 struct iscsi_session *session;
832 struct iscsi_sw_tcp_host *tcp_sw_host;
833 struct Scsi_Host *shost;
834
835 if (ep) {
836 printk(KERN_ERR "iscsi_tcp: invalid ep %p.\n", ep);
837 return NULL;
838 }
839
840 shost = iscsi_host_alloc(&iscsi_sw_tcp_sht,
841 sizeof(struct iscsi_sw_tcp_host), 1);
842 if (!shost)
843 return NULL;
844 shost->transportt = iscsi_sw_tcp_scsi_transport;
845 shost->cmd_per_lun = qdepth;
846 shost->max_lun = iscsi_max_lun;
847 shost->max_id = 0;
848 shost->max_channel = 0;
849 shost->max_cmd_len = SCSI_MAX_VARLEN_CDB_SIZE;
850
851 if (iscsi_host_add(shost, NULL))
852 goto free_host;
853
854 cls_session = iscsi_session_setup(&iscsi_sw_tcp_transport, shost,
855 cmds_max, 0,
856 sizeof(struct iscsi_tcp_task) +
857 sizeof(struct iscsi_sw_tcp_hdrbuf),
858 initial_cmdsn, 0);
859 if (!cls_session)
860 goto remove_host;
861 session = cls_session->dd_data;
862 tcp_sw_host = iscsi_host_priv(shost);
863 tcp_sw_host->session = session;
864
865 shost->can_queue = session->scsi_cmds_max;
866 if (iscsi_tcp_r2tpool_alloc(session))
867 goto remove_session;
868 return cls_session;
869
870remove_session:
871 iscsi_session_teardown(cls_session);
872remove_host:
873 iscsi_host_remove(shost);
874free_host:
875 iscsi_host_free(shost);
876 return NULL;
877}
878
879static void iscsi_sw_tcp_session_destroy(struct iscsi_cls_session *cls_session)
880{
881 struct Scsi_Host *shost = iscsi_session_to_shost(cls_session);
882
883 iscsi_tcp_r2tpool_free(cls_session->dd_data);
884 iscsi_session_teardown(cls_session);
885
886 iscsi_host_remove(shost);
887 iscsi_host_free(shost);
888}
889
890static umode_t iscsi_sw_tcp_attr_is_visible(int param_type, int param)
891{
892 switch (param_type) {
893 case ISCSI_HOST_PARAM:
894 switch (param) {
895 case ISCSI_HOST_PARAM_NETDEV_NAME:
896 case ISCSI_HOST_PARAM_HWADDRESS:
897 case ISCSI_HOST_PARAM_IPADDRESS:
898 case ISCSI_HOST_PARAM_INITIATOR_NAME:
899 return S_IRUGO;
900 default:
901 return 0;
902 }
903 case ISCSI_PARAM:
904 switch (param) {
905 case ISCSI_PARAM_MAX_RECV_DLENGTH:
906 case ISCSI_PARAM_MAX_XMIT_DLENGTH:
907 case ISCSI_PARAM_HDRDGST_EN:
908 case ISCSI_PARAM_DATADGST_EN:
909 case ISCSI_PARAM_CONN_ADDRESS:
910 case ISCSI_PARAM_CONN_PORT:
911 case ISCSI_PARAM_LOCAL_PORT:
912 case ISCSI_PARAM_EXP_STATSN:
913 case ISCSI_PARAM_PERSISTENT_ADDRESS:
914 case ISCSI_PARAM_PERSISTENT_PORT:
915 case ISCSI_PARAM_PING_TMO:
916 case ISCSI_PARAM_RECV_TMO:
917 case ISCSI_PARAM_INITIAL_R2T_EN:
918 case ISCSI_PARAM_MAX_R2T:
919 case ISCSI_PARAM_IMM_DATA_EN:
920 case ISCSI_PARAM_FIRST_BURST:
921 case ISCSI_PARAM_MAX_BURST:
922 case ISCSI_PARAM_PDU_INORDER_EN:
923 case ISCSI_PARAM_DATASEQ_INORDER_EN:
924 case ISCSI_PARAM_ERL:
925 case ISCSI_PARAM_TARGET_NAME:
926 case ISCSI_PARAM_TPGT:
927 case ISCSI_PARAM_USERNAME:
928 case ISCSI_PARAM_PASSWORD:
929 case ISCSI_PARAM_USERNAME_IN:
930 case ISCSI_PARAM_PASSWORD_IN:
931 case ISCSI_PARAM_FAST_ABORT:
932 case ISCSI_PARAM_ABORT_TMO:
933 case ISCSI_PARAM_LU_RESET_TMO:
934 case ISCSI_PARAM_TGT_RESET_TMO:
935 case ISCSI_PARAM_IFACE_NAME:
936 case ISCSI_PARAM_INITIATOR_NAME:
937 return S_IRUGO;
938 default:
939 return 0;
940 }
941 }
942
943 return 0;
944}
945
946static int iscsi_sw_tcp_slave_configure(struct scsi_device *sdev)
947{
948 struct iscsi_sw_tcp_host *tcp_sw_host = iscsi_host_priv(sdev->host);
949 struct iscsi_session *session = tcp_sw_host->session;
950 struct iscsi_conn *conn = session->leadconn;
951
952 if (conn->datadgst_en)
953 sdev->request_queue->backing_dev_info->capabilities
954 |= BDI_CAP_STABLE_WRITES;
955 blk_queue_dma_alignment(sdev->request_queue, 0);
956 return 0;
957}
958
959static struct scsi_host_template iscsi_sw_tcp_sht = {
960 .module = THIS_MODULE,
961 .name = "iSCSI Initiator over TCP/IP",
962 .queuecommand = iscsi_queuecommand,
963 .change_queue_depth = scsi_change_queue_depth,
964 .can_queue = ISCSI_DEF_XMIT_CMDS_MAX - 1,
965 .sg_tablesize = 4096,
966 .max_sectors = 0xFFFF,
967 .cmd_per_lun = ISCSI_DEF_CMD_PER_LUN,
968 .eh_timed_out = iscsi_eh_cmd_timed_out,
969 .eh_abort_handler = iscsi_eh_abort,
970 .eh_device_reset_handler= iscsi_eh_device_reset,
971 .eh_target_reset_handler = iscsi_eh_recover_target,
972 .dma_boundary = PAGE_SIZE - 1,
973 .slave_configure = iscsi_sw_tcp_slave_configure,
974 .target_alloc = iscsi_target_alloc,
975 .proc_name = "iscsi_tcp",
976 .this_id = -1,
977 .track_queue_depth = 1,
978};
979
980static struct iscsi_transport iscsi_sw_tcp_transport = {
981 .owner = THIS_MODULE,
982 .name = "tcp",
983 .caps = CAP_RECOVERY_L0 | CAP_MULTI_R2T | CAP_HDRDGST
984 | CAP_DATADGST,
985 /* session management */
986 .create_session = iscsi_sw_tcp_session_create,
987 .destroy_session = iscsi_sw_tcp_session_destroy,
988 /* connection management */
989 .create_conn = iscsi_sw_tcp_conn_create,
990 .bind_conn = iscsi_sw_tcp_conn_bind,
991 .destroy_conn = iscsi_sw_tcp_conn_destroy,
992 .attr_is_visible = iscsi_sw_tcp_attr_is_visible,
993 .set_param = iscsi_sw_tcp_conn_set_param,
994 .get_conn_param = iscsi_sw_tcp_conn_get_param,
995 .get_session_param = iscsi_session_get_param,
996 .start_conn = iscsi_conn_start,
997 .stop_conn = iscsi_sw_tcp_conn_stop,
998 /* iscsi host params */
999 .get_host_param = iscsi_sw_tcp_host_get_param,
1000 .set_host_param = iscsi_host_set_param,
1001 /* IO */
1002 .send_pdu = iscsi_conn_send_pdu,
1003 .get_stats = iscsi_sw_tcp_conn_get_stats,
1004 /* iscsi task/cmd helpers */
1005 .init_task = iscsi_tcp_task_init,
1006 .xmit_task = iscsi_tcp_task_xmit,
1007 .cleanup_task = iscsi_tcp_cleanup_task,
1008 /* low level pdu helpers */
1009 .xmit_pdu = iscsi_sw_tcp_pdu_xmit,
1010 .init_pdu = iscsi_sw_tcp_pdu_init,
1011 .alloc_pdu = iscsi_sw_tcp_pdu_alloc,
1012 /* recovery */
1013 .session_recovery_timedout = iscsi_session_recovery_timedout,
1014};
1015
1016static int __init iscsi_sw_tcp_init(void)
1017{
1018 if (iscsi_max_lun < 1) {
1019 printk(KERN_ERR "iscsi_tcp: Invalid max_lun value of %u\n",
1020 iscsi_max_lun);
1021 return -EINVAL;
1022 }
1023
1024 iscsi_sw_tcp_scsi_transport = iscsi_register_transport(
1025 &iscsi_sw_tcp_transport);
1026 if (!iscsi_sw_tcp_scsi_transport)
1027 return -ENODEV;
1028
1029 return 0;
1030}
1031
1032static void __exit iscsi_sw_tcp_exit(void)
1033{
1034 iscsi_unregister_transport(&iscsi_sw_tcp_transport);
1035}
1036
1037module_init(iscsi_sw_tcp_init);
1038module_exit(iscsi_sw_tcp_exit);