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QE/FHCI: fixed the CONTROL bug
[zen-stable.git] / drivers / scsi / iscsi_tcp.c
blob7724414588fa9b2c076530298b0b6c0d280ae685
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
47 MODULE_AUTHOR("Mike Christie <michaelc@cs.wisc.edu>, "
48 "Dmitry Yusupov <dmitry_yus@yahoo.com>, "
49 "Alex Aizman <itn780@yahoo.com>");
50 MODULE_DESCRIPTION("iSCSI/TCP data-path");
51 MODULE_LICENSE("GPL");
52
53 static struct scsi_transport_template *iscsi_sw_tcp_scsi_transport;
54 static struct scsi_host_template iscsi_sw_tcp_sht;
55 static struct iscsi_transport iscsi_sw_tcp_transport;
56
57 static unsigned int iscsi_max_lun = 512;
58 module_param_named(max_lun, iscsi_max_lun, uint, S_IRUGO);
59
60 static int iscsi_sw_tcp_dbg;
61 module_param_named(debug_iscsi_tcp, iscsi_sw_tcp_dbg, int,
62 S_IRUGO | S_IWUSR);
63 MODULE_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 */
82 static 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 */
113 static 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
126 static 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
158 static 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 **/
189 static 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
214 static 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
232 static void
233 iscsi_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 */
262 static 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 **/
310 static 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
349 error:
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 */
360 static 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
369 static 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 */
389 static 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
402 static 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 */
441 static int
442 iscsi_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
468 static void
469 iscsi_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
492 static 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
520 static 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
529 static struct iscsi_cls_conn *
530 iscsi_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
561 free_tx_tfm:
562 crypto_free_hash(tcp_sw_conn->tx_hash.tfm);
563 free_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
573 static 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
593 static 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
609 static 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
632 static int
633 iscsi_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
676 free_socket:
677 sockfd_put(sock);
678 return err;
679 }
680
681 static 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
718 static 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
750 static 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
792 static void
793 iscsi_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
811 static struct iscsi_cls_session *
812 iscsi_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
855 remove_session:
856 iscsi_session_teardown(cls_session);
857 remove_host:
858 iscsi_host_remove(shost);
859 free_host:
860 iscsi_host_free(shost);
861 return NULL;
862 }
863
864 static 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
875 static 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
881 static 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
888 static 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
908 static 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
970 static 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
986 static void __exit iscsi_sw_tcp_exit(void)
987 {
988 iscsi_unregister_transport(&iscsi_sw_tcp_transport);
989 }
990
991 module_init(iscsi_sw_tcp_init);
992 module_exit(iscsi_sw_tcp_exit);