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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 <linux/types.h>
30#include <linux/inet.h>
31#include <linux/slab.h>
32#include <linux/file.h>
33#include <linux/blkdev.h>
34#include <linux/crypto.h>
35#include <linux/delay.h>
36#include <linux/kfifo.h>
37#include <linux/scatterlist.h>
38#include <net/tcp.h>
39#include <scsi/scsi_cmnd.h>
40#include <scsi/scsi_device.h>
41#include <scsi/scsi_host.h>
42#include <scsi/scsi.h>
43#include <scsi/scsi_transport_iscsi.h>
44
45#include "iscsi_tcp.h"
46
47MODULE_AUTHOR("Mike Christie <michaelc@cs.wisc.edu>, "
48 "Dmitry Yusupov <dmitry_yus@yahoo.com>, "
49 "Alex Aizman <itn780@yahoo.com>");
50MODULE_DESCRIPTION("iSCSI/TCP data-path");
51MODULE_LICENSE("GPL");
52
53static struct scsi_transport_template *iscsi_sw_tcp_scsi_transport;
54static struct scsi_host_template iscsi_sw_tcp_sht;
55static struct iscsi_transport iscsi_sw_tcp_transport;
56
57static unsigned int iscsi_max_lun = 512;
58module_param_named(max_lun, iscsi_max_lun, uint, S_IRUGO);
59
60static int iscsi_sw_tcp_dbg;
61module_param_named(debug_iscsi_tcp, iscsi_sw_tcp_dbg, int,
62 S_IRUGO | S_IWUSR);
63MODULE_PARM_DESC(debug_iscsi_tcp, "Turn on debugging for iscsi_tcp module "
64 "Set to 1 to turn on, and zero to turn off. Default is off.");
65
66#define ISCSI_SW_TCP_DBG(_conn, dbg_fmt, arg...) \
67 do { \
68 if (iscsi_sw_tcp_dbg) \
69 iscsi_conn_printk(KERN_INFO, _conn, \
70 "%s " dbg_fmt, \
71 __func__, ##arg); \
72 } while (0);
73
74
75/**
76 * iscsi_sw_tcp_recv - TCP receive in sendfile fashion
77 * @rd_desc: read descriptor
78 * @skb: socket buffer
79 * @offset: offset in skb
80 * @len: skb->len - offset
81 */
82static int iscsi_sw_tcp_recv(read_descriptor_t *rd_desc, struct sk_buff *skb,
83 unsigned int offset, size_t len)
84{
85 struct iscsi_conn *conn = rd_desc->arg.data;
86 unsigned int consumed, total_consumed = 0;
87 int status;
88
89 ISCSI_SW_TCP_DBG(conn, "in %d bytes\n", skb->len - offset);
90
91 do {
92 status = 0;
93 consumed = iscsi_tcp_recv_skb(conn, skb, offset, 0, &status);
94 offset += consumed;
95 total_consumed += consumed;
96 } while (consumed != 0 && status != ISCSI_TCP_SKB_DONE);
97
98 ISCSI_SW_TCP_DBG(conn, "read %d bytes status %d\n",
99 skb->len - offset, status);
100 return total_consumed;
101}
102
103/**
104 * iscsi_sw_sk_state_check - check socket state
105 * @sk: socket
106 *
107 * If the socket is in CLOSE or CLOSE_WAIT we should
108 * not close the connection if there is still some
109 * data pending.
110 *
111 * Must be called with sk_callback_lock.
112 */
113static inline int iscsi_sw_sk_state_check(struct sock *sk)
114{
115 struct iscsi_conn *conn = sk->sk_user_data;
116
117 if ((sk->sk_state == TCP_CLOSE_WAIT || sk->sk_state == TCP_CLOSE) &&
118 !atomic_read(&sk->sk_rmem_alloc)) {
119 ISCSI_SW_TCP_DBG(conn, "TCP_CLOSE|TCP_CLOSE_WAIT\n");
120 iscsi_conn_failure(conn, ISCSI_ERR_TCP_CONN_CLOSE);
121 return -ECONNRESET;
122 }
123 return 0;
124}
125
126static void iscsi_sw_tcp_data_ready(struct sock *sk, int flag)
127{
128 struct iscsi_conn *conn;
129 struct iscsi_tcp_conn *tcp_conn;
130 read_descriptor_t rd_desc;
131
132 read_lock(&sk->sk_callback_lock);
133 conn = sk->sk_user_data;
134 if (!conn) {
135 read_unlock(&sk->sk_callback_lock);
136 return;
137 }
138 tcp_conn = conn->dd_data;
139
140 /*
141 * Use rd_desc to pass 'conn' to iscsi_tcp_recv.
142 * We set count to 1 because we want the network layer to
143 * hand us all the skbs that are available. iscsi_tcp_recv
144 * handled pdus that cross buffers or pdus that still need data.
145 */
146 rd_desc.arg.data = conn;
147 rd_desc.count = 1;
148 tcp_read_sock(sk, &rd_desc, iscsi_sw_tcp_recv);
149
150 iscsi_sw_sk_state_check(sk);
151
152 /* If we had to (atomically) map a highmem page,
153 * unmap it now. */
154 iscsi_tcp_segment_unmap(&tcp_conn->in.segment);
155 read_unlock(&sk->sk_callback_lock);
156}
157
158static void iscsi_sw_tcp_state_change(struct sock *sk)
159{
160 struct iscsi_tcp_conn *tcp_conn;
161 struct iscsi_sw_tcp_conn *tcp_sw_conn;
162 struct iscsi_conn *conn;
163 struct iscsi_session *session;
164 void (*old_state_change)(struct sock *);
165
166 read_lock(&sk->sk_callback_lock);
167 conn = sk->sk_user_data;
168 if (!conn) {
169 read_unlock(&sk->sk_callback_lock);
170 return;
171 }
172 session = conn->session;
173
174 iscsi_sw_sk_state_check(sk);
175
176 tcp_conn = conn->dd_data;
177 tcp_sw_conn = tcp_conn->dd_data;
178 old_state_change = tcp_sw_conn->old_state_change;
179
180 read_unlock(&sk->sk_callback_lock);
181
182 old_state_change(sk);
183}
184
185/**
186 * iscsi_write_space - Called when more output buffer space is available
187 * @sk: socket space is available for
188 **/
189static void iscsi_sw_tcp_write_space(struct sock *sk)
190{
191 struct iscsi_conn *conn;
192 struct iscsi_tcp_conn *tcp_conn;
193 struct iscsi_sw_tcp_conn *tcp_sw_conn;
194 void (*old_write_space)(struct sock *);
195
196 read_lock_bh(&sk->sk_callback_lock);
197 conn = sk->sk_user_data;
198 if (!conn) {
199 read_unlock_bh(&sk->sk_callback_lock);
200 return;
201 }
202
203 tcp_conn = conn->dd_data;
204 tcp_sw_conn = tcp_conn->dd_data;
205 old_write_space = tcp_sw_conn->old_write_space;
206 read_unlock_bh(&sk->sk_callback_lock);
207
208 old_write_space(sk);
209
210 ISCSI_SW_TCP_DBG(conn, "iscsi_write_space\n");
211 iscsi_conn_queue_work(conn);
212}
213
214static void iscsi_sw_tcp_conn_set_callbacks(struct iscsi_conn *conn)
215{
216 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
217 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
218 struct sock *sk = tcp_sw_conn->sock->sk;
219
220 /* assign new callbacks */
221 write_lock_bh(&sk->sk_callback_lock);
222 sk->sk_user_data = conn;
223 tcp_sw_conn->old_data_ready = sk->sk_data_ready;
224 tcp_sw_conn->old_state_change = sk->sk_state_change;
225 tcp_sw_conn->old_write_space = sk->sk_write_space;
226 sk->sk_data_ready = iscsi_sw_tcp_data_ready;
227 sk->sk_state_change = iscsi_sw_tcp_state_change;
228 sk->sk_write_space = iscsi_sw_tcp_write_space;
229 write_unlock_bh(&sk->sk_callback_lock);
230}
231
232static void
233iscsi_sw_tcp_conn_restore_callbacks(struct iscsi_conn *conn)
234{
235 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
236 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
237 struct sock *sk = tcp_sw_conn->sock->sk;
238
239 /* restore socket callbacks, see also: iscsi_conn_set_callbacks() */
240 write_lock_bh(&sk->sk_callback_lock);
241 sk->sk_user_data = NULL;
242 sk->sk_data_ready = tcp_sw_conn->old_data_ready;
243 sk->sk_state_change = tcp_sw_conn->old_state_change;
244 sk->sk_write_space = tcp_sw_conn->old_write_space;
245 sk->sk_no_check = 0;
246 write_unlock_bh(&sk->sk_callback_lock);
247}
248
249/**
250 * iscsi_sw_tcp_xmit_segment - transmit segment
251 * @tcp_conn: the iSCSI TCP connection
252 * @segment: the buffer to transmnit
253 *
254 * This function transmits as much of the buffer as
255 * the network layer will accept, and returns the number of
256 * bytes transmitted.
257 *
258 * If CRC hashing is enabled, the function will compute the
259 * hash as it goes. When the entire segment has been transmitted,
260 * it will retrieve the hash value and send it as well.
261 */
262static int iscsi_sw_tcp_xmit_segment(struct iscsi_tcp_conn *tcp_conn,
263 struct iscsi_segment *segment)
264{
265 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
266 struct socket *sk = tcp_sw_conn->sock;
267 unsigned int copied = 0;
268 int r = 0;
269
270 while (!iscsi_tcp_segment_done(tcp_conn, segment, 0, r)) {
271 struct scatterlist *sg;
272 unsigned int offset, copy;
273 int flags = 0;
274
275 r = 0;
276 offset = segment->copied;
277 copy = segment->size - offset;
278
279 if (segment->total_copied + segment->size < segment->total_size)
280 flags |= MSG_MORE;
281
282 /* Use sendpage if we can; else fall back to sendmsg */
283 if (!segment->data) {
284 sg = segment->sg;
285 offset += segment->sg_offset + sg->offset;
286 r = tcp_sw_conn->sendpage(sk, sg_page(sg), offset,
287 copy, flags);
288 } else {
289 struct msghdr msg = { .msg_flags = flags };
290 struct kvec iov = {
291 .iov_base = segment->data + offset,
292 .iov_len = copy
293 };
294
295 r = kernel_sendmsg(sk, &msg, &iov, 1, copy);
296 }
297
298 if (r < 0) {
299 iscsi_tcp_segment_unmap(segment);
300 return r;
301 }
302 copied += r;
303 }
304 return copied;
305}
306
307/**
308 * iscsi_sw_tcp_xmit - TCP transmit
309 **/
310static int iscsi_sw_tcp_xmit(struct iscsi_conn *conn)
311{
312 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
313 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
314 struct iscsi_segment *segment = &tcp_sw_conn->out.segment;
315 unsigned int consumed = 0;
316 int rc = 0;
317
318 while (1) {
319 rc = iscsi_sw_tcp_xmit_segment(tcp_conn, segment);
320 /*
321 * We may not have been able to send data because the conn
322 * is getting stopped. libiscsi will know so propagate err
323 * for it to do the right thing.
324 */
325 if (rc == -EAGAIN)
326 return rc;
327 else if (rc < 0) {
328 rc = ISCSI_ERR_XMIT_FAILED;
329 goto error;
330 } else if (rc == 0)
331 break;
332
333 consumed += rc;
334
335 if (segment->total_copied >= segment->total_size) {
336 if (segment->done != NULL) {
337 rc = segment->done(tcp_conn, segment);
338 if (rc != 0)
339 goto error;
340 }
341 }
342 }
343
344 ISCSI_SW_TCP_DBG(conn, "xmit %d bytes\n", consumed);
345
346 conn->txdata_octets += consumed;
347 return consumed;
348
349error:
350 /* Transmit error. We could initiate error recovery
351 * here. */
352 ISCSI_SW_TCP_DBG(conn, "Error sending PDU, errno=%d\n", rc);
353 iscsi_conn_failure(conn, rc);
354 return -EIO;
355}
356
357/**
358 * iscsi_tcp_xmit_qlen - return the number of bytes queued for xmit
359 */
360static inline int iscsi_sw_tcp_xmit_qlen(struct iscsi_conn *conn)
361{
362 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
363 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
364 struct iscsi_segment *segment = &tcp_sw_conn->out.segment;
365
366 return segment->total_copied - segment->total_size;
367}
368
369static int iscsi_sw_tcp_pdu_xmit(struct iscsi_task *task)
370{
371 struct iscsi_conn *conn = task->conn;
372 int rc;
373
374 while (iscsi_sw_tcp_xmit_qlen(conn)) {
375 rc = iscsi_sw_tcp_xmit(conn);
376 if (rc == 0)
377 return -EAGAIN;
378 if (rc < 0)
379 return rc;
380 }
381
382 return 0;
383}
384
385/*
386 * This is called when we're done sending the header.
387 * Simply copy the data_segment to the send segment, and return.
388 */
389static int iscsi_sw_tcp_send_hdr_done(struct iscsi_tcp_conn *tcp_conn,
390 struct iscsi_segment *segment)
391{
392 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
393
394 tcp_sw_conn->out.segment = tcp_sw_conn->out.data_segment;
395 ISCSI_SW_TCP_DBG(tcp_conn->iscsi_conn,
396 "Header done. Next segment size %u total_size %u\n",
397 tcp_sw_conn->out.segment.size,
398 tcp_sw_conn->out.segment.total_size);
399 return 0;
400}
401
402static void iscsi_sw_tcp_send_hdr_prep(struct iscsi_conn *conn, void *hdr,
403 size_t hdrlen)
404{
405 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
406 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
407
408 ISCSI_SW_TCP_DBG(conn, "%s\n", conn->hdrdgst_en ?
409 "digest enabled" : "digest disabled");
410
411 /* Clear the data segment - needs to be filled in by the
412 * caller using iscsi_tcp_send_data_prep() */
413 memset(&tcp_sw_conn->out.data_segment, 0,
414 sizeof(struct iscsi_segment));
415
416 /* If header digest is enabled, compute the CRC and
417 * place the digest into the same buffer. We make
418 * sure that both iscsi_tcp_task and mtask have
419 * sufficient room.
420 */
421 if (conn->hdrdgst_en) {
422 iscsi_tcp_dgst_header(&tcp_sw_conn->tx_hash, hdr, hdrlen,
423 hdr + hdrlen);
424 hdrlen += ISCSI_DIGEST_SIZE;
425 }
426
427 /* Remember header pointer for later, when we need
428 * to decide whether there's a payload to go along
429 * with the header. */
430 tcp_sw_conn->out.hdr = hdr;
431
432 iscsi_segment_init_linear(&tcp_sw_conn->out.segment, hdr, hdrlen,
433 iscsi_sw_tcp_send_hdr_done, NULL);
434}
435
436/*
437 * Prepare the send buffer for the payload data.
438 * Padding and checksumming will all be taken care
439 * of by the iscsi_segment routines.
440 */
441static int
442iscsi_sw_tcp_send_data_prep(struct iscsi_conn *conn, struct scatterlist *sg,
443 unsigned int count, unsigned int offset,
444 unsigned int len)
445{
446 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
447 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
448 struct hash_desc *tx_hash = NULL;
449 unsigned int hdr_spec_len;
450
451 ISCSI_SW_TCP_DBG(conn, "offset=%d, datalen=%d %s\n", offset, len,
452 conn->datadgst_en ?
453 "digest enabled" : "digest disabled");
454
455 /* Make sure the datalen matches what the caller
456 said he would send. */
457 hdr_spec_len = ntoh24(tcp_sw_conn->out.hdr->dlength);
458 WARN_ON(iscsi_padded(len) != iscsi_padded(hdr_spec_len));
459
460 if (conn->datadgst_en)
461 tx_hash = &tcp_sw_conn->tx_hash;
462
463 return iscsi_segment_seek_sg(&tcp_sw_conn->out.data_segment,
464 sg, count, offset, len,
465 NULL, tx_hash);
466}
467
468static void
469iscsi_sw_tcp_send_linear_data_prep(struct iscsi_conn *conn, void *data,
470 size_t len)
471{
472 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
473 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
474 struct hash_desc *tx_hash = NULL;
475 unsigned int hdr_spec_len;
476
477 ISCSI_SW_TCP_DBG(conn, "datalen=%zd %s\n", len, conn->datadgst_en ?
478 "digest enabled" : "digest disabled");
479
480 /* Make sure the datalen matches what the caller
481 said he would send. */
482 hdr_spec_len = ntoh24(tcp_sw_conn->out.hdr->dlength);
483 WARN_ON(iscsi_padded(len) != iscsi_padded(hdr_spec_len));
484
485 if (conn->datadgst_en)
486 tx_hash = &tcp_sw_conn->tx_hash;
487
488 iscsi_segment_init_linear(&tcp_sw_conn->out.data_segment,
489 data, len, NULL, tx_hash);
490}
491
492static int iscsi_sw_tcp_pdu_init(struct iscsi_task *task,
493 unsigned int offset, unsigned int count)
494{
495 struct iscsi_conn *conn = task->conn;
496 int err = 0;
497
498 iscsi_sw_tcp_send_hdr_prep(conn, task->hdr, task->hdr_len);
499
500 if (!count)
501 return 0;
502
503 if (!task->sc)
504 iscsi_sw_tcp_send_linear_data_prep(conn, task->data, count);
505 else {
506 struct scsi_data_buffer *sdb = scsi_out(task->sc);
507
508 err = iscsi_sw_tcp_send_data_prep(conn, sdb->table.sgl,
509 sdb->table.nents, offset,
510 count);
511 }
512
513 if (err) {
514 /* got invalid offset/len */
515 return -EIO;
516 }
517 return 0;
518}
519
520static int iscsi_sw_tcp_pdu_alloc(struct iscsi_task *task, uint8_t opcode)
521{
522 struct iscsi_tcp_task *tcp_task = task->dd_data;
523
524 task->hdr = task->dd_data + sizeof(*tcp_task);
525 task->hdr_max = sizeof(struct iscsi_sw_tcp_hdrbuf) - ISCSI_DIGEST_SIZE;
526 return 0;
527}
528
529static struct iscsi_cls_conn *
530iscsi_sw_tcp_conn_create(struct iscsi_cls_session *cls_session,
531 uint32_t conn_idx)
532{
533 struct iscsi_conn *conn;
534 struct iscsi_cls_conn *cls_conn;
535 struct iscsi_tcp_conn *tcp_conn;
536 struct iscsi_sw_tcp_conn *tcp_sw_conn;
537
538 cls_conn = iscsi_tcp_conn_setup(cls_session, sizeof(*tcp_sw_conn),
539 conn_idx);
540 if (!cls_conn)
541 return NULL;
542 conn = cls_conn->dd_data;
543 tcp_conn = conn->dd_data;
544 tcp_sw_conn = tcp_conn->dd_data;
545
546 tcp_sw_conn->tx_hash.tfm = crypto_alloc_hash("crc32c", 0,
547 CRYPTO_ALG_ASYNC);
548 tcp_sw_conn->tx_hash.flags = 0;
549 if (IS_ERR(tcp_sw_conn->tx_hash.tfm))
550 goto free_conn;
551
552 tcp_sw_conn->rx_hash.tfm = crypto_alloc_hash("crc32c", 0,
553 CRYPTO_ALG_ASYNC);
554 tcp_sw_conn->rx_hash.flags = 0;
555 if (IS_ERR(tcp_sw_conn->rx_hash.tfm))
556 goto free_tx_tfm;
557 tcp_conn->rx_hash = &tcp_sw_conn->rx_hash;
558
559 return cls_conn;
560
561free_tx_tfm:
562 crypto_free_hash(tcp_sw_conn->tx_hash.tfm);
563free_conn:
564 iscsi_conn_printk(KERN_ERR, conn,
565 "Could not create connection due to crc32c "
566 "loading error. Make sure the crc32c "
567 "module is built as a module or into the "
568 "kernel\n");
569 iscsi_tcp_conn_teardown(cls_conn);
570 return NULL;
571}
572
573static void iscsi_sw_tcp_release_conn(struct iscsi_conn *conn)
574{
575 struct iscsi_session *session = conn->session;
576 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
577 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
578 struct socket *sock = tcp_sw_conn->sock;
579
580 if (!sock)
581 return;
582
583 sock_hold(sock->sk);
584 iscsi_sw_tcp_conn_restore_callbacks(conn);
585 sock_put(sock->sk);
586
587 spin_lock_bh(&session->lock);
588 tcp_sw_conn->sock = NULL;
589 spin_unlock_bh(&session->lock);
590 sockfd_put(sock);
591}
592
593static void iscsi_sw_tcp_conn_destroy(struct iscsi_cls_conn *cls_conn)
594{
595 struct iscsi_conn *conn = cls_conn->dd_data;
596 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
597 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
598
599 iscsi_sw_tcp_release_conn(conn);
600
601 if (tcp_sw_conn->tx_hash.tfm)
602 crypto_free_hash(tcp_sw_conn->tx_hash.tfm);
603 if (tcp_sw_conn->rx_hash.tfm)
604 crypto_free_hash(tcp_sw_conn->rx_hash.tfm);
605
606 iscsi_tcp_conn_teardown(cls_conn);
607}
608
609static void iscsi_sw_tcp_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
610{
611 struct iscsi_conn *conn = cls_conn->dd_data;
612 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
613 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
614 struct socket *sock = tcp_sw_conn->sock;
615
616 /* userspace may have goofed up and not bound us */
617 if (!sock)
618 return;
619
620 sock->sk->sk_err = EIO;
621 wake_up_interruptible(sk_sleep(sock->sk));
622
623 /* stop xmit side */
624 iscsi_suspend_tx(conn);
625
626 /* stop recv side and release socket */
627 iscsi_sw_tcp_release_conn(conn);
628
629 iscsi_conn_stop(cls_conn, flag);
630}
631
632static int
633iscsi_sw_tcp_conn_bind(struct iscsi_cls_session *cls_session,
634 struct iscsi_cls_conn *cls_conn, uint64_t transport_eph,
635 int is_leading)
636{
637 struct iscsi_session *session = cls_session->dd_data;
638 struct iscsi_conn *conn = cls_conn->dd_data;
639 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
640 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
641 struct sock *sk;
642 struct socket *sock;
643 int err;
644
645 /* lookup for existing socket */
646 sock = sockfd_lookup((int)transport_eph, &err);
647 if (!sock) {
648 iscsi_conn_printk(KERN_ERR, conn,
649 "sockfd_lookup failed %d\n", err);
650 return -EEXIST;
651 }
652
653 err = iscsi_conn_bind(cls_session, cls_conn, is_leading);
654 if (err)
655 goto free_socket;
656
657 spin_lock_bh(&session->lock);
658 /* bind iSCSI connection and socket */
659 tcp_sw_conn->sock = sock;
660 spin_unlock_bh(&session->lock);
661
662 /* setup Socket parameters */
663 sk = sock->sk;
664 sk->sk_reuse = 1;
665 sk->sk_sndtimeo = 15 * HZ; /* FIXME: make it configurable */
666 sk->sk_allocation = GFP_ATOMIC;
667
668 iscsi_sw_tcp_conn_set_callbacks(conn);
669 tcp_sw_conn->sendpage = tcp_sw_conn->sock->ops->sendpage;
670 /*
671 * set receive state machine into initial state
672 */
673 iscsi_tcp_hdr_recv_prep(tcp_conn);
674 return 0;
675
676free_socket:
677 sockfd_put(sock);
678 return err;
679}
680
681static int iscsi_sw_tcp_conn_set_param(struct iscsi_cls_conn *cls_conn,
682 enum iscsi_param param, char *buf,
683 int buflen)
684{
685 struct iscsi_conn *conn = cls_conn->dd_data;
686 struct iscsi_session *session = conn->session;
687 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
688 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
689 int value;
690
691 switch(param) {
692 case ISCSI_PARAM_HDRDGST_EN:
693 iscsi_set_param(cls_conn, param, buf, buflen);
694 break;
695 case ISCSI_PARAM_DATADGST_EN:
696 iscsi_set_param(cls_conn, param, buf, buflen);
697 tcp_sw_conn->sendpage = conn->datadgst_en ?
698 sock_no_sendpage : tcp_sw_conn->sock->ops->sendpage;
699 break;
700 case ISCSI_PARAM_MAX_R2T:
701 sscanf(buf, "%d", &value);
702 if (value <= 0 || !is_power_of_2(value))
703 return -EINVAL;
704 if (session->max_r2t == value)
705 break;
706 iscsi_tcp_r2tpool_free(session);
707 iscsi_set_param(cls_conn, param, buf, buflen);
708 if (iscsi_tcp_r2tpool_alloc(session))
709 return -ENOMEM;
710 break;
711 default:
712 return iscsi_set_param(cls_conn, param, buf, buflen);
713 }
714
715 return 0;
716}
717
718static int iscsi_sw_tcp_conn_get_param(struct iscsi_cls_conn *cls_conn,
719 enum iscsi_param param, char *buf)
720{
721 struct iscsi_conn *conn = cls_conn->dd_data;
722 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
723 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
724 struct sockaddr_in6 addr;
725 int rc, len;
726
727 switch(param) {
728 case ISCSI_PARAM_CONN_PORT:
729 case ISCSI_PARAM_CONN_ADDRESS:
730 spin_lock_bh(&conn->session->lock);
731 if (!tcp_sw_conn || !tcp_sw_conn->sock) {
732 spin_unlock_bh(&conn->session->lock);
733 return -ENOTCONN;
734 }
735 rc = kernel_getpeername(tcp_sw_conn->sock,
736 (struct sockaddr *)&addr, &len);
737 spin_unlock_bh(&conn->session->lock);
738 if (rc)
739 return rc;
740
741 return iscsi_conn_get_addr_param((struct sockaddr_storage *)
742 &addr, param, buf);
743 default:
744 return iscsi_conn_get_param(cls_conn, param, buf);
745 }
746
747 return 0;
748}
749
750static int iscsi_sw_tcp_host_get_param(struct Scsi_Host *shost,
751 enum iscsi_host_param param, char *buf)
752{
753 struct iscsi_sw_tcp_host *tcp_sw_host = iscsi_host_priv(shost);
754 struct iscsi_session *session = tcp_sw_host->session;
755 struct iscsi_conn *conn;
756 struct iscsi_tcp_conn *tcp_conn;
757 struct iscsi_sw_tcp_conn *tcp_sw_conn;
758 struct sockaddr_in6 addr;
759 int rc, len;
760
761 switch (param) {
762 case ISCSI_HOST_PARAM_IPADDRESS:
763 spin_lock_bh(&session->lock);
764 conn = session->leadconn;
765 if (!conn) {
766 spin_unlock_bh(&session->lock);
767 return -ENOTCONN;
768 }
769 tcp_conn = conn->dd_data;
770
771 tcp_sw_conn = tcp_conn->dd_data;
772 if (!tcp_sw_conn->sock) {
773 spin_unlock_bh(&session->lock);
774 return -ENOTCONN;
775 }
776
777 rc = kernel_getsockname(tcp_sw_conn->sock,
778 (struct sockaddr *)&addr, &len);
779 spin_unlock_bh(&session->lock);
780 if (rc)
781 return rc;
782
783 return iscsi_conn_get_addr_param((struct sockaddr_storage *)
784 &addr, param, buf);
785 default:
786 return iscsi_host_get_param(shost, param, buf);
787 }
788
789 return 0;
790}
791
792static void
793iscsi_sw_tcp_conn_get_stats(struct iscsi_cls_conn *cls_conn,
794 struct iscsi_stats *stats)
795{
796 struct iscsi_conn *conn = cls_conn->dd_data;
797 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
798 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
799
800 stats->custom_length = 3;
801 strcpy(stats->custom[0].desc, "tx_sendpage_failures");
802 stats->custom[0].value = tcp_sw_conn->sendpage_failures_cnt;
803 strcpy(stats->custom[1].desc, "rx_discontiguous_hdr");
804 stats->custom[1].value = tcp_sw_conn->discontiguous_hdr_cnt;
805 strcpy(stats->custom[2].desc, "eh_abort_cnt");
806 stats->custom[2].value = conn->eh_abort_cnt;
807
808 iscsi_tcp_conn_get_stats(cls_conn, stats);
809}
810
811static struct iscsi_cls_session *
812iscsi_sw_tcp_session_create(struct iscsi_endpoint *ep, uint16_t cmds_max,
813 uint16_t qdepth, uint32_t initial_cmdsn)
814{
815 struct iscsi_cls_session *cls_session;
816 struct iscsi_session *session;
817 struct iscsi_sw_tcp_host *tcp_sw_host;
818 struct Scsi_Host *shost;
819
820 if (ep) {
821 printk(KERN_ERR "iscsi_tcp: invalid ep %p.\n", ep);
822 return NULL;
823 }
824
825 shost = iscsi_host_alloc(&iscsi_sw_tcp_sht,
826 sizeof(struct iscsi_sw_tcp_host), 1);
827 if (!shost)
828 return NULL;
829 shost->transportt = iscsi_sw_tcp_scsi_transport;
830 shost->cmd_per_lun = qdepth;
831 shost->max_lun = iscsi_max_lun;
832 shost->max_id = 0;
833 shost->max_channel = 0;
834 shost->max_cmd_len = SCSI_MAX_VARLEN_CDB_SIZE;
835
836 if (iscsi_host_add(shost, NULL))
837 goto free_host;
838
839 cls_session = iscsi_session_setup(&iscsi_sw_tcp_transport, shost,
840 cmds_max, 0,
841 sizeof(struct iscsi_tcp_task) +
842 sizeof(struct iscsi_sw_tcp_hdrbuf),
843 initial_cmdsn, 0);
844 if (!cls_session)
845 goto remove_host;
846 session = cls_session->dd_data;
847 tcp_sw_host = iscsi_host_priv(shost);
848 tcp_sw_host->session = session;
849
850 shost->can_queue = session->scsi_cmds_max;
851 if (iscsi_tcp_r2tpool_alloc(session))
852 goto remove_session;
853 return cls_session;
854
855remove_session:
856 iscsi_session_teardown(cls_session);
857remove_host:
858 iscsi_host_remove(shost);
859free_host:
860 iscsi_host_free(shost);
861 return NULL;
862}
863
864static void iscsi_sw_tcp_session_destroy(struct iscsi_cls_session *cls_session)
865{
866 struct Scsi_Host *shost = iscsi_session_to_shost(cls_session);
867
868 iscsi_tcp_r2tpool_free(cls_session->dd_data);
869 iscsi_session_teardown(cls_session);
870
871 iscsi_host_remove(shost);
872 iscsi_host_free(shost);
873}
874
875static int iscsi_sw_tcp_slave_alloc(struct scsi_device *sdev)
876{
877 set_bit(QUEUE_FLAG_BIDI, &sdev->request_queue->queue_flags);
878 return 0;
879}
880
881static int iscsi_sw_tcp_slave_configure(struct scsi_device *sdev)
882{
883 blk_queue_bounce_limit(sdev->request_queue, BLK_BOUNCE_ANY);
884 blk_queue_dma_alignment(sdev->request_queue, 0);
885 return 0;
886}
887
888static struct scsi_host_template iscsi_sw_tcp_sht = {
889 .module = THIS_MODULE,
890 .name = "iSCSI Initiator over TCP/IP",
891 .queuecommand = iscsi_queuecommand,
892 .change_queue_depth = iscsi_change_queue_depth,
893 .can_queue = ISCSI_DEF_XMIT_CMDS_MAX - 1,
894 .sg_tablesize = 4096,
895 .max_sectors = 0xFFFF,
896 .cmd_per_lun = ISCSI_DEF_CMD_PER_LUN,
897 .eh_abort_handler = iscsi_eh_abort,
898 .eh_device_reset_handler= iscsi_eh_device_reset,
899 .eh_target_reset_handler = iscsi_eh_recover_target,
900 .use_clustering = DISABLE_CLUSTERING,
901 .slave_alloc = iscsi_sw_tcp_slave_alloc,
902 .slave_configure = iscsi_sw_tcp_slave_configure,
903 .target_alloc = iscsi_target_alloc,
904 .proc_name = "iscsi_tcp",
905 .this_id = -1,
906};
907
908static struct iscsi_transport iscsi_sw_tcp_transport = {
909 .owner = THIS_MODULE,
910 .name = "tcp",
911 .caps = CAP_RECOVERY_L0 | CAP_MULTI_R2T | CAP_HDRDGST
912 | CAP_DATADGST,
913 .param_mask = ISCSI_MAX_RECV_DLENGTH |
914 ISCSI_MAX_XMIT_DLENGTH |
915 ISCSI_HDRDGST_EN |
916 ISCSI_DATADGST_EN |
917 ISCSI_INITIAL_R2T_EN |
918 ISCSI_MAX_R2T |
919 ISCSI_IMM_DATA_EN |
920 ISCSI_FIRST_BURST |
921 ISCSI_MAX_BURST |
922 ISCSI_PDU_INORDER_EN |
923 ISCSI_DATASEQ_INORDER_EN |
924 ISCSI_ERL |
925 ISCSI_CONN_PORT |
926 ISCSI_CONN_ADDRESS |
927 ISCSI_EXP_STATSN |
928 ISCSI_PERSISTENT_PORT |
929 ISCSI_PERSISTENT_ADDRESS |
930 ISCSI_TARGET_NAME | ISCSI_TPGT |
931 ISCSI_USERNAME | ISCSI_PASSWORD |
932 ISCSI_USERNAME_IN | ISCSI_PASSWORD_IN |
933 ISCSI_FAST_ABORT | ISCSI_ABORT_TMO |
934 ISCSI_LU_RESET_TMO | ISCSI_TGT_RESET_TMO |
935 ISCSI_PING_TMO | ISCSI_RECV_TMO |
936 ISCSI_IFACE_NAME | ISCSI_INITIATOR_NAME,
937 .host_param_mask = ISCSI_HOST_HWADDRESS | ISCSI_HOST_IPADDRESS |
938 ISCSI_HOST_INITIATOR_NAME |
939 ISCSI_HOST_NETDEV_NAME,
940 /* session management */
941 .create_session = iscsi_sw_tcp_session_create,
942 .destroy_session = iscsi_sw_tcp_session_destroy,
943 /* connection management */
944 .create_conn = iscsi_sw_tcp_conn_create,
945 .bind_conn = iscsi_sw_tcp_conn_bind,
946 .destroy_conn = iscsi_sw_tcp_conn_destroy,
947 .set_param = iscsi_sw_tcp_conn_set_param,
948 .get_conn_param = iscsi_sw_tcp_conn_get_param,
949 .get_session_param = iscsi_session_get_param,
950 .start_conn = iscsi_conn_start,
951 .stop_conn = iscsi_sw_tcp_conn_stop,
952 /* iscsi host params */
953 .get_host_param = iscsi_sw_tcp_host_get_param,
954 .set_host_param = iscsi_host_set_param,
955 /* IO */
956 .send_pdu = iscsi_conn_send_pdu,
957 .get_stats = iscsi_sw_tcp_conn_get_stats,
958 /* iscsi task/cmd helpers */
959 .init_task = iscsi_tcp_task_init,
960 .xmit_task = iscsi_tcp_task_xmit,
961 .cleanup_task = iscsi_tcp_cleanup_task,
962 /* low level pdu helpers */
963 .xmit_pdu = iscsi_sw_tcp_pdu_xmit,
964 .init_pdu = iscsi_sw_tcp_pdu_init,
965 .alloc_pdu = iscsi_sw_tcp_pdu_alloc,
966 /* recovery */
967 .session_recovery_timedout = iscsi_session_recovery_timedout,
968};
969
970static int __init iscsi_sw_tcp_init(void)
971{
972 if (iscsi_max_lun < 1) {
973 printk(KERN_ERR "iscsi_tcp: Invalid max_lun value of %u\n",
974 iscsi_max_lun);
975 return -EINVAL;
976 }
977
978 iscsi_sw_tcp_scsi_transport = iscsi_register_transport(
979 &iscsi_sw_tcp_transport);
980 if (!iscsi_sw_tcp_scsi_transport)
981 return -ENODEV;
982
983 return 0;
984}
985
986static void __exit iscsi_sw_tcp_exit(void)
987{
988 iscsi_unregister_transport(&iscsi_sw_tcp_transport);
989}
990
991module_init(iscsi_sw_tcp_init);
992module_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 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
373 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
374 int rc = 0;
375
376 if (!tcp_sw_conn->sock) {
377 iscsi_conn_printk(KERN_ERR, conn,
378 "Transport not bound to socket!\n");
379 return -EINVAL;
380 }
381
382 noreclaim_flag = memalloc_noreclaim_save();
383
384 while (iscsi_sw_tcp_xmit_qlen(conn)) {
385 rc = iscsi_sw_tcp_xmit(conn);
386 if (rc == 0) {
387 rc = -EAGAIN;
388 break;
389 }
390 if (rc < 0)
391 break;
392 rc = 0;
393 }
394
395 memalloc_noreclaim_restore(noreclaim_flag);
396 return rc;
397}
398
399/*
400 * This is called when we're done sending the header.
401 * Simply copy the data_segment to the send segment, and return.
402 */
403static int iscsi_sw_tcp_send_hdr_done(struct iscsi_tcp_conn *tcp_conn,
404 struct iscsi_segment *segment)
405{
406 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
407
408 tcp_sw_conn->out.segment = tcp_sw_conn->out.data_segment;
409 ISCSI_SW_TCP_DBG(tcp_conn->iscsi_conn,
410 "Header done. Next segment size %u total_size %u\n",
411 tcp_sw_conn->out.segment.size,
412 tcp_sw_conn->out.segment.total_size);
413 return 0;
414}
415
416static void iscsi_sw_tcp_send_hdr_prep(struct iscsi_conn *conn, void *hdr,
417 size_t hdrlen)
418{
419 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
420 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
421
422 ISCSI_SW_TCP_DBG(conn, "%s\n", conn->hdrdgst_en ?
423 "digest enabled" : "digest disabled");
424
425 /* Clear the data segment - needs to be filled in by the
426 * caller using iscsi_tcp_send_data_prep() */
427 memset(&tcp_sw_conn->out.data_segment, 0,
428 sizeof(struct iscsi_segment));
429
430 /* If header digest is enabled, compute the CRC and
431 * place the digest into the same buffer. We make
432 * sure that both iscsi_tcp_task and mtask have
433 * sufficient room.
434 */
435 if (conn->hdrdgst_en) {
436 iscsi_tcp_dgst_header(tcp_sw_conn->tx_hash, hdr, hdrlen,
437 hdr + hdrlen);
438 hdrlen += ISCSI_DIGEST_SIZE;
439 }
440
441 /* Remember header pointer for later, when we need
442 * to decide whether there's a payload to go along
443 * with the header. */
444 tcp_sw_conn->out.hdr = hdr;
445
446 iscsi_segment_init_linear(&tcp_sw_conn->out.segment, hdr, hdrlen,
447 iscsi_sw_tcp_send_hdr_done, NULL);
448}
449
450/*
451 * Prepare the send buffer for the payload data.
452 * Padding and checksumming will all be taken care
453 * of by the iscsi_segment routines.
454 */
455static int
456iscsi_sw_tcp_send_data_prep(struct iscsi_conn *conn, struct scatterlist *sg,
457 unsigned int count, unsigned int offset,
458 unsigned int len)
459{
460 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
461 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
462 struct ahash_request *tx_hash = NULL;
463 unsigned int hdr_spec_len;
464
465 ISCSI_SW_TCP_DBG(conn, "offset=%d, datalen=%d %s\n", offset, len,
466 conn->datadgst_en ?
467 "digest enabled" : "digest disabled");
468
469 /* Make sure the datalen matches what the caller
470 said he would send. */
471 hdr_spec_len = ntoh24(tcp_sw_conn->out.hdr->dlength);
472 WARN_ON(iscsi_padded(len) != iscsi_padded(hdr_spec_len));
473
474 if (conn->datadgst_en)
475 tx_hash = tcp_sw_conn->tx_hash;
476
477 return iscsi_segment_seek_sg(&tcp_sw_conn->out.data_segment,
478 sg, count, offset, len,
479 NULL, tx_hash);
480}
481
482static void
483iscsi_sw_tcp_send_linear_data_prep(struct iscsi_conn *conn, void *data,
484 size_t len)
485{
486 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
487 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
488 struct ahash_request *tx_hash = NULL;
489 unsigned int hdr_spec_len;
490
491 ISCSI_SW_TCP_DBG(conn, "datalen=%zd %s\n", len, conn->datadgst_en ?
492 "digest enabled" : "digest disabled");
493
494 /* Make sure the datalen matches what the caller
495 said he would send. */
496 hdr_spec_len = ntoh24(tcp_sw_conn->out.hdr->dlength);
497 WARN_ON(iscsi_padded(len) != iscsi_padded(hdr_spec_len));
498
499 if (conn->datadgst_en)
500 tx_hash = tcp_sw_conn->tx_hash;
501
502 iscsi_segment_init_linear(&tcp_sw_conn->out.data_segment,
503 data, len, NULL, tx_hash);
504}
505
506static int iscsi_sw_tcp_pdu_init(struct iscsi_task *task,
507 unsigned int offset, unsigned int count)
508{
509 struct iscsi_conn *conn = task->conn;
510 int err = 0;
511
512 iscsi_sw_tcp_send_hdr_prep(conn, task->hdr, task->hdr_len);
513
514 if (!count)
515 return 0;
516
517 if (!task->sc)
518 iscsi_sw_tcp_send_linear_data_prep(conn, task->data, count);
519 else {
520 struct scsi_data_buffer *sdb = &task->sc->sdb;
521
522 err = iscsi_sw_tcp_send_data_prep(conn, sdb->table.sgl,
523 sdb->table.nents, offset,
524 count);
525 }
526
527 if (err) {
528 /* got invalid offset/len */
529 return -EIO;
530 }
531 return 0;
532}
533
534static int iscsi_sw_tcp_pdu_alloc(struct iscsi_task *task, uint8_t opcode)
535{
536 struct iscsi_tcp_task *tcp_task = task->dd_data;
537
538 task->hdr = task->dd_data + sizeof(*tcp_task);
539 task->hdr_max = sizeof(struct iscsi_sw_tcp_hdrbuf) - ISCSI_DIGEST_SIZE;
540 return 0;
541}
542
543static struct iscsi_cls_conn *
544iscsi_sw_tcp_conn_create(struct iscsi_cls_session *cls_session,
545 uint32_t conn_idx)
546{
547 struct iscsi_conn *conn;
548 struct iscsi_cls_conn *cls_conn;
549 struct iscsi_tcp_conn *tcp_conn;
550 struct iscsi_sw_tcp_conn *tcp_sw_conn;
551 struct crypto_ahash *tfm;
552
553 cls_conn = iscsi_tcp_conn_setup(cls_session, sizeof(*tcp_sw_conn),
554 conn_idx);
555 if (!cls_conn)
556 return NULL;
557 conn = cls_conn->dd_data;
558 tcp_conn = conn->dd_data;
559 tcp_sw_conn = tcp_conn->dd_data;
560
561 tfm = crypto_alloc_ahash("crc32c", 0, CRYPTO_ALG_ASYNC);
562 if (IS_ERR(tfm))
563 goto free_conn;
564
565 tcp_sw_conn->tx_hash = ahash_request_alloc(tfm, GFP_KERNEL);
566 if (!tcp_sw_conn->tx_hash)
567 goto free_tfm;
568 ahash_request_set_callback(tcp_sw_conn->tx_hash, 0, NULL, NULL);
569
570 tcp_sw_conn->rx_hash = ahash_request_alloc(tfm, GFP_KERNEL);
571 if (!tcp_sw_conn->rx_hash)
572 goto free_tx_hash;
573 ahash_request_set_callback(tcp_sw_conn->rx_hash, 0, NULL, NULL);
574
575 tcp_conn->rx_hash = tcp_sw_conn->rx_hash;
576
577 return cls_conn;
578
579free_tx_hash:
580 ahash_request_free(tcp_sw_conn->tx_hash);
581free_tfm:
582 crypto_free_ahash(tfm);
583free_conn:
584 iscsi_conn_printk(KERN_ERR, conn,
585 "Could not create connection due to crc32c "
586 "loading error. Make sure the crc32c "
587 "module is built as a module or into the "
588 "kernel\n");
589 iscsi_tcp_conn_teardown(cls_conn);
590 return NULL;
591}
592
593static void iscsi_sw_tcp_release_conn(struct iscsi_conn *conn)
594{
595 struct iscsi_session *session = conn->session;
596 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
597 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
598 struct socket *sock = tcp_sw_conn->sock;
599
600 if (!sock)
601 return;
602
603 sock_hold(sock->sk);
604 iscsi_sw_tcp_conn_restore_callbacks(conn);
605 sock_put(sock->sk);
606
607 spin_lock_bh(&session->frwd_lock);
608 tcp_sw_conn->sock = NULL;
609 spin_unlock_bh(&session->frwd_lock);
610 sockfd_put(sock);
611}
612
613static void iscsi_sw_tcp_conn_destroy(struct iscsi_cls_conn *cls_conn)
614{
615 struct iscsi_conn *conn = cls_conn->dd_data;
616 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
617 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
618
619 iscsi_sw_tcp_release_conn(conn);
620
621 ahash_request_free(tcp_sw_conn->rx_hash);
622 if (tcp_sw_conn->tx_hash) {
623 struct crypto_ahash *tfm;
624
625 tfm = crypto_ahash_reqtfm(tcp_sw_conn->tx_hash);
626 ahash_request_free(tcp_sw_conn->tx_hash);
627 crypto_free_ahash(tfm);
628 }
629
630 iscsi_tcp_conn_teardown(cls_conn);
631}
632
633static void iscsi_sw_tcp_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
634{
635 struct iscsi_conn *conn = cls_conn->dd_data;
636 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
637 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
638 struct socket *sock = tcp_sw_conn->sock;
639
640 /* userspace may have goofed up and not bound us */
641 if (!sock)
642 return;
643
644 sock->sk->sk_err = EIO;
645 wake_up_interruptible(sk_sleep(sock->sk));
646
647 /* stop xmit side */
648 iscsi_suspend_tx(conn);
649
650 /* stop recv side and release socket */
651 iscsi_sw_tcp_release_conn(conn);
652
653 iscsi_conn_stop(cls_conn, flag);
654}
655
656static int
657iscsi_sw_tcp_conn_bind(struct iscsi_cls_session *cls_session,
658 struct iscsi_cls_conn *cls_conn, uint64_t transport_eph,
659 int is_leading)
660{
661 struct iscsi_session *session = cls_session->dd_data;
662 struct iscsi_conn *conn = cls_conn->dd_data;
663 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
664 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
665 struct sock *sk;
666 struct socket *sock;
667 int err;
668
669 /* lookup for existing socket */
670 sock = sockfd_lookup((int)transport_eph, &err);
671 if (!sock) {
672 iscsi_conn_printk(KERN_ERR, conn,
673 "sockfd_lookup failed %d\n", err);
674 return -EEXIST;
675 }
676
677 err = iscsi_conn_bind(cls_session, cls_conn, is_leading);
678 if (err)
679 goto free_socket;
680
681 spin_lock_bh(&session->frwd_lock);
682 /* bind iSCSI connection and socket */
683 tcp_sw_conn->sock = sock;
684 spin_unlock_bh(&session->frwd_lock);
685
686 /* setup Socket parameters */
687 sk = sock->sk;
688 sk->sk_reuse = SK_CAN_REUSE;
689 sk->sk_sndtimeo = 15 * HZ; /* FIXME: make it configurable */
690 sk->sk_allocation = GFP_ATOMIC;
691 sk_set_memalloc(sk);
692
693 iscsi_sw_tcp_conn_set_callbacks(conn);
694 tcp_sw_conn->sendpage = tcp_sw_conn->sock->ops->sendpage;
695 /*
696 * set receive state machine into initial state
697 */
698 iscsi_tcp_hdr_recv_prep(tcp_conn);
699 return 0;
700
701free_socket:
702 sockfd_put(sock);
703 return err;
704}
705
706static int iscsi_sw_tcp_conn_set_param(struct iscsi_cls_conn *cls_conn,
707 enum iscsi_param param, char *buf,
708 int buflen)
709{
710 struct iscsi_conn *conn = cls_conn->dd_data;
711 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
712 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
713
714 switch(param) {
715 case ISCSI_PARAM_HDRDGST_EN:
716 iscsi_set_param(cls_conn, param, buf, buflen);
717 break;
718 case ISCSI_PARAM_DATADGST_EN:
719 iscsi_set_param(cls_conn, param, buf, buflen);
720 tcp_sw_conn->sendpage = conn->datadgst_en ?
721 sock_no_sendpage : tcp_sw_conn->sock->ops->sendpage;
722 break;
723 case ISCSI_PARAM_MAX_R2T:
724 return iscsi_tcp_set_max_r2t(conn, buf);
725 default:
726 return iscsi_set_param(cls_conn, param, buf, buflen);
727 }
728
729 return 0;
730}
731
732static int iscsi_sw_tcp_conn_get_param(struct iscsi_cls_conn *cls_conn,
733 enum iscsi_param param, char *buf)
734{
735 struct iscsi_conn *conn = cls_conn->dd_data;
736 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
737 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
738 struct sockaddr_in6 addr;
739 struct socket *sock;
740 int rc;
741
742 switch(param) {
743 case ISCSI_PARAM_CONN_PORT:
744 case ISCSI_PARAM_CONN_ADDRESS:
745 case ISCSI_PARAM_LOCAL_PORT:
746 spin_lock_bh(&conn->session->frwd_lock);
747 if (!tcp_sw_conn || !tcp_sw_conn->sock) {
748 spin_unlock_bh(&conn->session->frwd_lock);
749 return -ENOTCONN;
750 }
751 sock = tcp_sw_conn->sock;
752 sock_hold(sock->sk);
753 spin_unlock_bh(&conn->session->frwd_lock);
754
755 if (param == ISCSI_PARAM_LOCAL_PORT)
756 rc = kernel_getsockname(sock,
757 (struct sockaddr *)&addr);
758 else
759 rc = kernel_getpeername(sock,
760 (struct sockaddr *)&addr);
761 sock_put(sock->sk);
762 if (rc < 0)
763 return rc;
764
765 return iscsi_conn_get_addr_param((struct sockaddr_storage *)
766 &addr, param, buf);
767 default:
768 return iscsi_conn_get_param(cls_conn, param, buf);
769 }
770
771 return 0;
772}
773
774static int iscsi_sw_tcp_host_get_param(struct Scsi_Host *shost,
775 enum iscsi_host_param param, char *buf)
776{
777 struct iscsi_sw_tcp_host *tcp_sw_host = iscsi_host_priv(shost);
778 struct iscsi_session *session = tcp_sw_host->session;
779 struct iscsi_conn *conn;
780 struct iscsi_tcp_conn *tcp_conn;
781 struct iscsi_sw_tcp_conn *tcp_sw_conn;
782 struct sockaddr_in6 addr;
783 struct socket *sock;
784 int rc;
785
786 switch (param) {
787 case ISCSI_HOST_PARAM_IPADDRESS:
788 if (!session)
789 return -ENOTCONN;
790
791 spin_lock_bh(&session->frwd_lock);
792 conn = session->leadconn;
793 if (!conn) {
794 spin_unlock_bh(&session->frwd_lock);
795 return -ENOTCONN;
796 }
797 tcp_conn = conn->dd_data;
798 tcp_sw_conn = tcp_conn->dd_data;
799 sock = tcp_sw_conn->sock;
800 if (!sock) {
801 spin_unlock_bh(&session->frwd_lock);
802 return -ENOTCONN;
803 }
804 sock_hold(sock->sk);
805 spin_unlock_bh(&session->frwd_lock);
806
807 rc = kernel_getsockname(sock,
808 (struct sockaddr *)&addr);
809 sock_put(sock->sk);
810 if (rc < 0)
811 return rc;
812
813 return iscsi_conn_get_addr_param((struct sockaddr_storage *)
814 &addr,
815 (enum iscsi_param)param, buf);
816 default:
817 return iscsi_host_get_param(shost, param, buf);
818 }
819
820 return 0;
821}
822
823static void
824iscsi_sw_tcp_conn_get_stats(struct iscsi_cls_conn *cls_conn,
825 struct iscsi_stats *stats)
826{
827 struct iscsi_conn *conn = cls_conn->dd_data;
828 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
829 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
830
831 stats->custom_length = 3;
832 strcpy(stats->custom[0].desc, "tx_sendpage_failures");
833 stats->custom[0].value = tcp_sw_conn->sendpage_failures_cnt;
834 strcpy(stats->custom[1].desc, "rx_discontiguous_hdr");
835 stats->custom[1].value = tcp_sw_conn->discontiguous_hdr_cnt;
836 strcpy(stats->custom[2].desc, "eh_abort_cnt");
837 stats->custom[2].value = conn->eh_abort_cnt;
838
839 iscsi_tcp_conn_get_stats(cls_conn, stats);
840}
841
842static struct iscsi_cls_session *
843iscsi_sw_tcp_session_create(struct iscsi_endpoint *ep, uint16_t cmds_max,
844 uint16_t qdepth, uint32_t initial_cmdsn)
845{
846 struct iscsi_cls_session *cls_session;
847 struct iscsi_session *session;
848 struct iscsi_sw_tcp_host *tcp_sw_host;
849 struct Scsi_Host *shost;
850
851 if (ep) {
852 printk(KERN_ERR "iscsi_tcp: invalid ep %p.\n", ep);
853 return NULL;
854 }
855
856 shost = iscsi_host_alloc(&iscsi_sw_tcp_sht,
857 sizeof(struct iscsi_sw_tcp_host), 1);
858 if (!shost)
859 return NULL;
860 shost->transportt = iscsi_sw_tcp_scsi_transport;
861 shost->cmd_per_lun = qdepth;
862 shost->max_lun = iscsi_max_lun;
863 shost->max_id = 0;
864 shost->max_channel = 0;
865 shost->max_cmd_len = SCSI_MAX_VARLEN_CDB_SIZE;
866
867 if (iscsi_host_add(shost, NULL))
868 goto free_host;
869
870 cls_session = iscsi_session_setup(&iscsi_sw_tcp_transport, shost,
871 cmds_max, 0,
872 sizeof(struct iscsi_tcp_task) +
873 sizeof(struct iscsi_sw_tcp_hdrbuf),
874 initial_cmdsn, 0);
875 if (!cls_session)
876 goto remove_host;
877 session = cls_session->dd_data;
878 tcp_sw_host = iscsi_host_priv(shost);
879 tcp_sw_host->session = session;
880
881 shost->can_queue = session->scsi_cmds_max;
882 if (iscsi_tcp_r2tpool_alloc(session))
883 goto remove_session;
884 return cls_session;
885
886remove_session:
887 iscsi_session_teardown(cls_session);
888remove_host:
889 iscsi_host_remove(shost);
890free_host:
891 iscsi_host_free(shost);
892 return NULL;
893}
894
895static void iscsi_sw_tcp_session_destroy(struct iscsi_cls_session *cls_session)
896{
897 struct Scsi_Host *shost = iscsi_session_to_shost(cls_session);
898 struct iscsi_session *session = cls_session->dd_data;
899
900 if (WARN_ON_ONCE(session->leadconn))
901 return;
902
903 iscsi_tcp_r2tpool_free(cls_session->dd_data);
904 iscsi_session_teardown(cls_session);
905
906 iscsi_host_remove(shost);
907 iscsi_host_free(shost);
908}
909
910static umode_t iscsi_sw_tcp_attr_is_visible(int param_type, int param)
911{
912 switch (param_type) {
913 case ISCSI_HOST_PARAM:
914 switch (param) {
915 case ISCSI_HOST_PARAM_NETDEV_NAME:
916 case ISCSI_HOST_PARAM_HWADDRESS:
917 case ISCSI_HOST_PARAM_IPADDRESS:
918 case ISCSI_HOST_PARAM_INITIATOR_NAME:
919 return S_IRUGO;
920 default:
921 return 0;
922 }
923 case ISCSI_PARAM:
924 switch (param) {
925 case ISCSI_PARAM_MAX_RECV_DLENGTH:
926 case ISCSI_PARAM_MAX_XMIT_DLENGTH:
927 case ISCSI_PARAM_HDRDGST_EN:
928 case ISCSI_PARAM_DATADGST_EN:
929 case ISCSI_PARAM_CONN_ADDRESS:
930 case ISCSI_PARAM_CONN_PORT:
931 case ISCSI_PARAM_LOCAL_PORT:
932 case ISCSI_PARAM_EXP_STATSN:
933 case ISCSI_PARAM_PERSISTENT_ADDRESS:
934 case ISCSI_PARAM_PERSISTENT_PORT:
935 case ISCSI_PARAM_PING_TMO:
936 case ISCSI_PARAM_RECV_TMO:
937 case ISCSI_PARAM_INITIAL_R2T_EN:
938 case ISCSI_PARAM_MAX_R2T:
939 case ISCSI_PARAM_IMM_DATA_EN:
940 case ISCSI_PARAM_FIRST_BURST:
941 case ISCSI_PARAM_MAX_BURST:
942 case ISCSI_PARAM_PDU_INORDER_EN:
943 case ISCSI_PARAM_DATASEQ_INORDER_EN:
944 case ISCSI_PARAM_ERL:
945 case ISCSI_PARAM_TARGET_NAME:
946 case ISCSI_PARAM_TPGT:
947 case ISCSI_PARAM_USERNAME:
948 case ISCSI_PARAM_PASSWORD:
949 case ISCSI_PARAM_USERNAME_IN:
950 case ISCSI_PARAM_PASSWORD_IN:
951 case ISCSI_PARAM_FAST_ABORT:
952 case ISCSI_PARAM_ABORT_TMO:
953 case ISCSI_PARAM_LU_RESET_TMO:
954 case ISCSI_PARAM_TGT_RESET_TMO:
955 case ISCSI_PARAM_IFACE_NAME:
956 case ISCSI_PARAM_INITIATOR_NAME:
957 return S_IRUGO;
958 default:
959 return 0;
960 }
961 }
962
963 return 0;
964}
965
966static int iscsi_sw_tcp_slave_configure(struct scsi_device *sdev)
967{
968 struct iscsi_sw_tcp_host *tcp_sw_host = iscsi_host_priv(sdev->host);
969 struct iscsi_session *session = tcp_sw_host->session;
970 struct iscsi_conn *conn = session->leadconn;
971
972 if (conn->datadgst_en)
973 sdev->request_queue->backing_dev_info->capabilities
974 |= BDI_CAP_STABLE_WRITES;
975 blk_queue_dma_alignment(sdev->request_queue, 0);
976 return 0;
977}
978
979static struct scsi_host_template iscsi_sw_tcp_sht = {
980 .module = THIS_MODULE,
981 .name = "iSCSI Initiator over TCP/IP",
982 .queuecommand = iscsi_queuecommand,
983 .change_queue_depth = scsi_change_queue_depth,
984 .can_queue = ISCSI_DEF_XMIT_CMDS_MAX - 1,
985 .sg_tablesize = 4096,
986 .max_sectors = 0xFFFF,
987 .cmd_per_lun = ISCSI_DEF_CMD_PER_LUN,
988 .eh_timed_out = iscsi_eh_cmd_timed_out,
989 .eh_abort_handler = iscsi_eh_abort,
990 .eh_device_reset_handler= iscsi_eh_device_reset,
991 .eh_target_reset_handler = iscsi_eh_recover_target,
992 .dma_boundary = PAGE_SIZE - 1,
993 .slave_configure = iscsi_sw_tcp_slave_configure,
994 .target_alloc = iscsi_target_alloc,
995 .proc_name = "iscsi_tcp",
996 .this_id = -1,
997 .track_queue_depth = 1,
998};
999
1000static struct iscsi_transport iscsi_sw_tcp_transport = {
1001 .owner = THIS_MODULE,
1002 .name = "tcp",
1003 .caps = CAP_RECOVERY_L0 | CAP_MULTI_R2T | CAP_HDRDGST
1004 | CAP_DATADGST,
1005 /* session management */
1006 .create_session = iscsi_sw_tcp_session_create,
1007 .destroy_session = iscsi_sw_tcp_session_destroy,
1008 /* connection management */
1009 .create_conn = iscsi_sw_tcp_conn_create,
1010 .bind_conn = iscsi_sw_tcp_conn_bind,
1011 .destroy_conn = iscsi_sw_tcp_conn_destroy,
1012 .attr_is_visible = iscsi_sw_tcp_attr_is_visible,
1013 .set_param = iscsi_sw_tcp_conn_set_param,
1014 .get_conn_param = iscsi_sw_tcp_conn_get_param,
1015 .get_session_param = iscsi_session_get_param,
1016 .start_conn = iscsi_conn_start,
1017 .stop_conn = iscsi_sw_tcp_conn_stop,
1018 /* iscsi host params */
1019 .get_host_param = iscsi_sw_tcp_host_get_param,
1020 .set_host_param = iscsi_host_set_param,
1021 /* IO */
1022 .send_pdu = iscsi_conn_send_pdu,
1023 .get_stats = iscsi_sw_tcp_conn_get_stats,
1024 /* iscsi task/cmd helpers */
1025 .init_task = iscsi_tcp_task_init,
1026 .xmit_task = iscsi_tcp_task_xmit,
1027 .cleanup_task = iscsi_tcp_cleanup_task,
1028 /* low level pdu helpers */
1029 .xmit_pdu = iscsi_sw_tcp_pdu_xmit,
1030 .init_pdu = iscsi_sw_tcp_pdu_init,
1031 .alloc_pdu = iscsi_sw_tcp_pdu_alloc,
1032 /* recovery */
1033 .session_recovery_timedout = iscsi_session_recovery_timedout,
1034};
1035
1036static int __init iscsi_sw_tcp_init(void)
1037{
1038 if (iscsi_max_lun < 1) {
1039 printk(KERN_ERR "iscsi_tcp: Invalid max_lun value of %u\n",
1040 iscsi_max_lun);
1041 return -EINVAL;
1042 }
1043
1044 iscsi_sw_tcp_scsi_transport = iscsi_register_transport(
1045 &iscsi_sw_tcp_transport);
1046 if (!iscsi_sw_tcp_scsi_transport)
1047 return -ENODEV;
1048
1049 return 0;
1050}
1051
1052static void __exit iscsi_sw_tcp_exit(void)
1053{
1054 iscsi_unregister_transport(&iscsi_sw_tcp_transport);
1055}
1056
1057module_init(iscsi_sw_tcp_init);
1058module_exit(iscsi_sw_tcp_exit);