1 /*
2 * iSCSI Initiator over TCP/IP Data-Path
3 *
4 * Copyright (C) 2004 Dmitry Yusupov
5 * Copyright (C) 2004 Alex Aizman
6 * Copyright (C) 2005 - 2006 Mike Christie
7 * Copyright (C) 2006 Red Hat, Inc. All rights reserved.
8 * maintained by open-iscsi@googlegroups.com
9 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published
12 * by the Free Software Foundation; either version 2 of the License, or
13 * (at your option) any later version.
14 *
15 * This program is distributed in the hope that it will be useful, but
16 * WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18 * General Public License for more details.
19 *
20 * See the file COPYING included with this distribution for more details.
21 *
22 * Credits:
23 * Christoph Hellwig
24 * FUJITA Tomonori
25 * Arne Redlich
26 * Zhenyu Wang
27 */
28
29 #include <crypto/hash.h>
30 #include <linux/types.h>
31 #include <linux/inet.h>
32 #include <linux/slab.h>
33 #include <linux/sched/mm.h>
34 #include <linux/file.h>
35 #include <linux/blkdev.h>
36 #include <linux/delay.h>
37 #include <linux/kfifo.h>
38 #include <linux/scatterlist.h>
39 #include <linux/module.h>
40 #include <linux/backing-dev.h>
41 #include <net/tcp.h>
42 #include <scsi/scsi_cmnd.h>
43 #include <scsi/scsi_device.h>
44 #include <scsi/scsi_host.h>
45 #include <scsi/scsi.h>
46 #include <scsi/scsi_transport_iscsi.h>
47
48 #include "iscsi_tcp.h"
49
50 MODULE_AUTHOR("Mike Christie <michaelc@cs.wisc.edu>, "
51 "Dmitry Yusupov <dmitry_yus@yahoo.com>, "
52 "Alex Aizman <itn780@yahoo.com>");
53 MODULE_DESCRIPTION("iSCSI/TCP data-path");
54 MODULE_LICENSE("GPL");
55
56 static struct scsi_transport_template *iscsi_sw_tcp_scsi_transport;
57 static struct scsi_host_template iscsi_sw_tcp_sht;
58 static struct iscsi_transport iscsi_sw_tcp_transport;
59
60 static unsigned int iscsi_max_lun = ~0;
61 module_param_named(max_lun, iscsi_max_lun, uint, S_IRUGO);
62
63 static int iscsi_sw_tcp_dbg;
64 module_param_named(debug_iscsi_tcp, iscsi_sw_tcp_dbg, int,
65 S_IRUGO | S_IWUSR);
66 MODULE_PARM_DESC(debug_iscsi_tcp, "Turn on debugging for iscsi_tcp module "
67 "Set to 1 to turn on, and zero to turn off. Default is off.");
68
69 #define ISCSI_SW_TCP_DBG(_conn, dbg_fmt, arg...) \
70 do { \
71 if (iscsi_sw_tcp_dbg) \
72 iscsi_conn_printk(KERN_INFO, _conn, \
73 "%s " dbg_fmt, \
74 __func__, ##arg); \
75 } while (0);
76
77
78 /**
79 * iscsi_sw_tcp_recv - TCP receive in sendfile fashion
80 * @rd_desc: read descriptor
81 * @skb: socket buffer
82 * @offset: offset in skb
83 * @len: skb->len - offset
84 */
iscsi_sw_tcp_recv(read_descriptor_t * rd_desc,struct sk_buff * skb,unsigned int offset,size_t len)85 static int iscsi_sw_tcp_recv(read_descriptor_t *rd_desc, struct sk_buff *skb,
86 unsigned int offset, size_t len)
87 {
88 struct iscsi_conn *conn = rd_desc->arg.data;
89 unsigned int consumed, total_consumed = 0;
90 int status;
91
92 ISCSI_SW_TCP_DBG(conn, "in %d bytes\n", skb->len - offset);
93
94 do {
95 status = 0;
96 consumed = iscsi_tcp_recv_skb(conn, skb, offset, 0, &status);
97 offset += consumed;
98 total_consumed += consumed;
99 } while (consumed != 0 && status != ISCSI_TCP_SKB_DONE);
100
101 ISCSI_SW_TCP_DBG(conn, "read %d bytes status %d\n",
102 skb->len - offset, status);
103 return total_consumed;
104 }
105
106 /**
107 * iscsi_sw_sk_state_check - check socket state
108 * @sk: socket
109 *
110 * If the socket is in CLOSE or CLOSE_WAIT we should
111 * not close the connection if there is still some
112 * data pending.
113 *
114 * Must be called with sk_callback_lock.
115 */
iscsi_sw_sk_state_check(struct sock * sk)116 static inline int iscsi_sw_sk_state_check(struct sock *sk)
117 {
118 struct iscsi_conn *conn = sk->sk_user_data;
119
120 if ((sk->sk_state == TCP_CLOSE_WAIT || sk->sk_state == TCP_CLOSE) &&
121 (conn->session->state != ISCSI_STATE_LOGGING_OUT) &&
122 !atomic_read(&sk->sk_rmem_alloc)) {
123 ISCSI_SW_TCP_DBG(conn, "TCP_CLOSE|TCP_CLOSE_WAIT\n");
124 iscsi_conn_failure(conn, ISCSI_ERR_TCP_CONN_CLOSE);
125 return -ECONNRESET;
126 }
127 return 0;
128 }
129
iscsi_sw_tcp_data_ready(struct sock * sk)130 static void iscsi_sw_tcp_data_ready(struct sock *sk)
131 {
132 struct iscsi_conn *conn;
133 struct iscsi_tcp_conn *tcp_conn;
134 read_descriptor_t rd_desc;
135
136 read_lock_bh(&sk->sk_callback_lock);
137 conn = sk->sk_user_data;
138 if (!conn) {
139 read_unlock_bh(&sk->sk_callback_lock);
140 return;
141 }
142 tcp_conn = conn->dd_data;
143
144 /*
145 * Use rd_desc to pass 'conn' to iscsi_tcp_recv.
146 * We set count to 1 because we want the network layer to
147 * hand us all the skbs that are available. iscsi_tcp_recv
148 * handled pdus that cross buffers or pdus that still need data.
149 */
150 rd_desc.arg.data = conn;
151 rd_desc.count = 1;
152 tcp_read_sock(sk, &rd_desc, iscsi_sw_tcp_recv);
153
154 iscsi_sw_sk_state_check(sk);
155
156 /* If we had to (atomically) map a highmem page,
157 * unmap it now. */
158 iscsi_tcp_segment_unmap(&tcp_conn->in.segment);
159 read_unlock_bh(&sk->sk_callback_lock);
160 }
161
iscsi_sw_tcp_state_change(struct sock * sk)162 static void iscsi_sw_tcp_state_change(struct sock *sk)
163 {
164 struct iscsi_tcp_conn *tcp_conn;
165 struct iscsi_sw_tcp_conn *tcp_sw_conn;
166 struct iscsi_conn *conn;
167 void (*old_state_change)(struct sock *);
168
169 read_lock_bh(&sk->sk_callback_lock);
170 conn = sk->sk_user_data;
171 if (!conn) {
172 read_unlock_bh(&sk->sk_callback_lock);
173 return;
174 }
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_bh(&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 **/
iscsi_sw_tcp_write_space(struct sock * sk)191 static 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
iscsi_sw_tcp_conn_set_callbacks(struct iscsi_conn * conn)216 static 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
234 static void
iscsi_sw_tcp_conn_restore_callbacks(struct iscsi_conn * conn)235 iscsi_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 */
iscsi_sw_tcp_xmit_segment(struct iscsi_tcp_conn * tcp_conn,struct iscsi_segment * segment)264 static 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 **/
iscsi_sw_tcp_xmit(struct iscsi_conn * conn)312 static int iscsi_sw_tcp_xmit(struct iscsi_conn *conn)
313 {
314 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
315 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
316 struct iscsi_segment *segment = &tcp_sw_conn->out.segment;
317 unsigned int consumed = 0;
318 int rc = 0;
319
320 while (1) {
321 rc = iscsi_sw_tcp_xmit_segment(tcp_conn, segment);
322 /*
323 * We may not have been able to send data because the conn
324 * is getting stopped. libiscsi will know so propagate err
325 * for it to do the right thing.
326 */
327 if (rc == -EAGAIN)
328 return rc;
329 else if (rc < 0) {
330 rc = ISCSI_ERR_XMIT_FAILED;
331 goto error;
332 } else if (rc == 0)
333 break;
334
335 consumed += rc;
336
337 if (segment->total_copied >= segment->total_size) {
338 if (segment->done != NULL) {
339 rc = segment->done(tcp_conn, segment);
340 if (rc != 0)
341 goto error;
342 }
343 }
344 }
345
346 ISCSI_SW_TCP_DBG(conn, "xmit %d bytes\n", consumed);
347
348 conn->txdata_octets += consumed;
349 return consumed;
350
351 error:
352 /* Transmit error. We could initiate error recovery
353 * here. */
354 ISCSI_SW_TCP_DBG(conn, "Error sending PDU, errno=%d\n", rc);
355 iscsi_conn_failure(conn, rc);
356 return -EIO;
357 }
358
359 /**
360 * iscsi_tcp_xmit_qlen - return the number of bytes queued for xmit
361 */
iscsi_sw_tcp_xmit_qlen(struct iscsi_conn * conn)362 static 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
iscsi_sw_tcp_pdu_xmit(struct iscsi_task * task)371 static int iscsi_sw_tcp_pdu_xmit(struct iscsi_task *task)
372 {
373 struct iscsi_conn *conn = task->conn;
374 unsigned int noreclaim_flag;
375 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
376 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
377 int rc = 0;
378
379 if (!tcp_sw_conn->sock) {
380 iscsi_conn_printk(KERN_ERR, conn,
381 "Transport not bound to socket!\n");
382 return -EINVAL;
383 }
384
385 noreclaim_flag = memalloc_noreclaim_save();
386
387 while (iscsi_sw_tcp_xmit_qlen(conn)) {
388 rc = iscsi_sw_tcp_xmit(conn);
389 if (rc == 0) {
390 rc = -EAGAIN;
391 break;
392 }
393 if (rc < 0)
394 break;
395 rc = 0;
396 }
397
398 memalloc_noreclaim_restore(noreclaim_flag);
399 return rc;
400 }
401
402 /*
403 * This is called when we're done sending the header.
404 * Simply copy the data_segment to the send segment, and return.
405 */
iscsi_sw_tcp_send_hdr_done(struct iscsi_tcp_conn * tcp_conn,struct iscsi_segment * segment)406 static int iscsi_sw_tcp_send_hdr_done(struct iscsi_tcp_conn *tcp_conn,
407 struct iscsi_segment *segment)
408 {
409 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
410
411 tcp_sw_conn->out.segment = tcp_sw_conn->out.data_segment;
412 ISCSI_SW_TCP_DBG(tcp_conn->iscsi_conn,
413 "Header done. Next segment size %u total_size %u\n",
414 tcp_sw_conn->out.segment.size,
415 tcp_sw_conn->out.segment.total_size);
416 return 0;
417 }
418
iscsi_sw_tcp_send_hdr_prep(struct iscsi_conn * conn,void * hdr,size_t hdrlen)419 static void iscsi_sw_tcp_send_hdr_prep(struct iscsi_conn *conn, void *hdr,
420 size_t hdrlen)
421 {
422 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
423 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
424
425 ISCSI_SW_TCP_DBG(conn, "%s\n", conn->hdrdgst_en ?
426 "digest enabled" : "digest disabled");
427
428 /* Clear the data segment - needs to be filled in by the
429 * caller using iscsi_tcp_send_data_prep() */
430 memset(&tcp_sw_conn->out.data_segment, 0,
431 sizeof(struct iscsi_segment));
432
433 /* If header digest is enabled, compute the CRC and
434 * place the digest into the same buffer. We make
435 * sure that both iscsi_tcp_task and mtask have
436 * sufficient room.
437 */
438 if (conn->hdrdgst_en) {
439 iscsi_tcp_dgst_header(tcp_sw_conn->tx_hash, hdr, hdrlen,
440 hdr + hdrlen);
441 hdrlen += ISCSI_DIGEST_SIZE;
442 }
443
444 /* Remember header pointer for later, when we need
445 * to decide whether there's a payload to go along
446 * with the header. */
447 tcp_sw_conn->out.hdr = hdr;
448
449 iscsi_segment_init_linear(&tcp_sw_conn->out.segment, hdr, hdrlen,
450 iscsi_sw_tcp_send_hdr_done, NULL);
451 }
452
453 /*
454 * Prepare the send buffer for the payload data.
455 * Padding and checksumming will all be taken care
456 * of by the iscsi_segment routines.
457 */
458 static int
iscsi_sw_tcp_send_data_prep(struct iscsi_conn * conn,struct scatterlist * sg,unsigned int count,unsigned int offset,unsigned int len)459 iscsi_sw_tcp_send_data_prep(struct iscsi_conn *conn, struct scatterlist *sg,
460 unsigned int count, unsigned int offset,
461 unsigned int len)
462 {
463 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
464 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
465 struct ahash_request *tx_hash = NULL;
466 unsigned int hdr_spec_len;
467
468 ISCSI_SW_TCP_DBG(conn, "offset=%d, datalen=%d %s\n", offset, len,
469 conn->datadgst_en ?
470 "digest enabled" : "digest disabled");
471
472 /* Make sure the datalen matches what the caller
473 said he would send. */
474 hdr_spec_len = ntoh24(tcp_sw_conn->out.hdr->dlength);
475 WARN_ON(iscsi_padded(len) != iscsi_padded(hdr_spec_len));
476
477 if (conn->datadgst_en)
478 tx_hash = tcp_sw_conn->tx_hash;
479
480 return iscsi_segment_seek_sg(&tcp_sw_conn->out.data_segment,
481 sg, count, offset, len,
482 NULL, tx_hash);
483 }
484
485 static void
iscsi_sw_tcp_send_linear_data_prep(struct iscsi_conn * conn,void * data,size_t len)486 iscsi_sw_tcp_send_linear_data_prep(struct iscsi_conn *conn, void *data,
487 size_t len)
488 {
489 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
490 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
491 struct ahash_request *tx_hash = NULL;
492 unsigned int hdr_spec_len;
493
494 ISCSI_SW_TCP_DBG(conn, "datalen=%zd %s\n", len, conn->datadgst_en ?
495 "digest enabled" : "digest disabled");
496
497 /* Make sure the datalen matches what the caller
498 said he would send. */
499 hdr_spec_len = ntoh24(tcp_sw_conn->out.hdr->dlength);
500 WARN_ON(iscsi_padded(len) != iscsi_padded(hdr_spec_len));
501
502 if (conn->datadgst_en)
503 tx_hash = tcp_sw_conn->tx_hash;
504
505 iscsi_segment_init_linear(&tcp_sw_conn->out.data_segment,
506 data, len, NULL, tx_hash);
507 }
508
iscsi_sw_tcp_pdu_init(struct iscsi_task * task,unsigned int offset,unsigned int count)509 static int iscsi_sw_tcp_pdu_init(struct iscsi_task *task,
510 unsigned int offset, unsigned int count)
511 {
512 struct iscsi_conn *conn = task->conn;
513 int err = 0;
514
515 iscsi_sw_tcp_send_hdr_prep(conn, task->hdr, task->hdr_len);
516
517 if (!count)
518 return 0;
519
520 if (!task->sc)
521 iscsi_sw_tcp_send_linear_data_prep(conn, task->data, count);
522 else {
523 struct scsi_data_buffer *sdb = scsi_out(task->sc);
524
525 err = iscsi_sw_tcp_send_data_prep(conn, sdb->table.sgl,
526 sdb->table.nents, offset,
527 count);
528 }
529
530 if (err) {
531 /* got invalid offset/len */
532 return -EIO;
533 }
534 return 0;
535 }
536
iscsi_sw_tcp_pdu_alloc(struct iscsi_task * task,uint8_t opcode)537 static int iscsi_sw_tcp_pdu_alloc(struct iscsi_task *task, uint8_t opcode)
538 {
539 struct iscsi_tcp_task *tcp_task = task->dd_data;
540
541 task->hdr = task->dd_data + sizeof(*tcp_task);
542 task->hdr_max = sizeof(struct iscsi_sw_tcp_hdrbuf) - ISCSI_DIGEST_SIZE;
543 return 0;
544 }
545
546 static struct iscsi_cls_conn *
iscsi_sw_tcp_conn_create(struct iscsi_cls_session * cls_session,uint32_t conn_idx)547 iscsi_sw_tcp_conn_create(struct iscsi_cls_session *cls_session,
548 uint32_t conn_idx)
549 {
550 struct iscsi_conn *conn;
551 struct iscsi_cls_conn *cls_conn;
552 struct iscsi_tcp_conn *tcp_conn;
553 struct iscsi_sw_tcp_conn *tcp_sw_conn;
554 struct crypto_ahash *tfm;
555
556 cls_conn = iscsi_tcp_conn_setup(cls_session, sizeof(*tcp_sw_conn),
557 conn_idx);
558 if (!cls_conn)
559 return NULL;
560 conn = cls_conn->dd_data;
561 tcp_conn = conn->dd_data;
562 tcp_sw_conn = tcp_conn->dd_data;
563
564 tfm = crypto_alloc_ahash("crc32c", 0, CRYPTO_ALG_ASYNC);
565 if (IS_ERR(tfm))
566 goto free_conn;
567
568 tcp_sw_conn->tx_hash = ahash_request_alloc(tfm, GFP_KERNEL);
569 if (!tcp_sw_conn->tx_hash)
570 goto free_tfm;
571 ahash_request_set_callback(tcp_sw_conn->tx_hash, 0, NULL, NULL);
572
573 tcp_sw_conn->rx_hash = ahash_request_alloc(tfm, GFP_KERNEL);
574 if (!tcp_sw_conn->rx_hash)
575 goto free_tx_hash;
576 ahash_request_set_callback(tcp_sw_conn->rx_hash, 0, NULL, NULL);
577
578 tcp_conn->rx_hash = tcp_sw_conn->rx_hash;
579
580 return cls_conn;
581
582 free_tx_hash:
583 ahash_request_free(tcp_sw_conn->tx_hash);
584 free_tfm:
585 crypto_free_ahash(tfm);
586 free_conn:
587 iscsi_conn_printk(KERN_ERR, conn,
588 "Could not create connection due to crc32c "
589 "loading error. Make sure the crc32c "
590 "module is built as a module or into the "
591 "kernel\n");
592 iscsi_tcp_conn_teardown(cls_conn);
593 return NULL;
594 }
595
iscsi_sw_tcp_release_conn(struct iscsi_conn * conn)596 static void iscsi_sw_tcp_release_conn(struct iscsi_conn *conn)
597 {
598 struct iscsi_session *session = conn->session;
599 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
600 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
601 struct socket *sock = tcp_sw_conn->sock;
602
603 if (!sock)
604 return;
605
606 sock_hold(sock->sk);
607 iscsi_sw_tcp_conn_restore_callbacks(conn);
608 sock_put(sock->sk);
609
610 spin_lock_bh(&session->frwd_lock);
611 tcp_sw_conn->sock = NULL;
612 spin_unlock_bh(&session->frwd_lock);
613 sockfd_put(sock);
614 }
615
iscsi_sw_tcp_conn_destroy(struct iscsi_cls_conn * cls_conn)616 static void iscsi_sw_tcp_conn_destroy(struct iscsi_cls_conn *cls_conn)
617 {
618 struct iscsi_conn *conn = cls_conn->dd_data;
619 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
620 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
621
622 iscsi_sw_tcp_release_conn(conn);
623
624 ahash_request_free(tcp_sw_conn->rx_hash);
625 if (tcp_sw_conn->tx_hash) {
626 struct crypto_ahash *tfm;
627
628 tfm = crypto_ahash_reqtfm(tcp_sw_conn->tx_hash);
629 ahash_request_free(tcp_sw_conn->tx_hash);
630 crypto_free_ahash(tfm);
631 }
632
633 iscsi_tcp_conn_teardown(cls_conn);
634 }
635
iscsi_sw_tcp_conn_stop(struct iscsi_cls_conn * cls_conn,int flag)636 static void iscsi_sw_tcp_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
637 {
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 socket *sock = tcp_sw_conn->sock;
642
643 /* userspace may have goofed up and not bound us */
644 if (!sock)
645 return;
646
647 sock->sk->sk_err = EIO;
648 wake_up_interruptible(sk_sleep(sock->sk));
649
650 /* stop xmit side */
651 iscsi_suspend_tx(conn);
652
653 /* stop recv side and release socket */
654 iscsi_sw_tcp_release_conn(conn);
655
656 iscsi_conn_stop(cls_conn, flag);
657 }
658
659 static int
iscsi_sw_tcp_conn_bind(struct iscsi_cls_session * cls_session,struct iscsi_cls_conn * cls_conn,uint64_t transport_eph,int is_leading)660 iscsi_sw_tcp_conn_bind(struct iscsi_cls_session *cls_session,
661 struct iscsi_cls_conn *cls_conn, uint64_t transport_eph,
662 int is_leading)
663 {
664 struct iscsi_session *session = cls_session->dd_data;
665 struct iscsi_conn *conn = cls_conn->dd_data;
666 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
667 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
668 struct sock *sk;
669 struct socket *sock;
670 int err;
671
672 /* lookup for existing socket */
673 sock = sockfd_lookup((int)transport_eph, &err);
674 if (!sock) {
675 iscsi_conn_printk(KERN_ERR, conn,
676 "sockfd_lookup failed %d\n", err);
677 return -EEXIST;
678 }
679
680 err = iscsi_conn_bind(cls_session, cls_conn, is_leading);
681 if (err)
682 goto free_socket;
683
684 spin_lock_bh(&session->frwd_lock);
685 /* bind iSCSI connection and socket */
686 tcp_sw_conn->sock = sock;
687 spin_unlock_bh(&session->frwd_lock);
688
689 /* setup Socket parameters */
690 sk = sock->sk;
691 sk->sk_reuse = SK_CAN_REUSE;
692 sk->sk_sndtimeo = 15 * HZ; /* FIXME: make it configurable */
693 sk->sk_allocation = GFP_ATOMIC;
694 sk_set_memalloc(sk);
695
696 iscsi_sw_tcp_conn_set_callbacks(conn);
697 tcp_sw_conn->sendpage = tcp_sw_conn->sock->ops->sendpage;
698 /*
699 * set receive state machine into initial state
700 */
701 iscsi_tcp_hdr_recv_prep(tcp_conn);
702 return 0;
703
704 free_socket:
705 sockfd_put(sock);
706 return err;
707 }
708
iscsi_sw_tcp_conn_set_param(struct iscsi_cls_conn * cls_conn,enum iscsi_param param,char * buf,int buflen)709 static int iscsi_sw_tcp_conn_set_param(struct iscsi_cls_conn *cls_conn,
710 enum iscsi_param param, char *buf,
711 int buflen)
712 {
713 struct iscsi_conn *conn = cls_conn->dd_data;
714 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
715 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
716
717 switch(param) {
718 case ISCSI_PARAM_HDRDGST_EN:
719 iscsi_set_param(cls_conn, param, buf, buflen);
720 break;
721 case ISCSI_PARAM_DATADGST_EN:
722 iscsi_set_param(cls_conn, param, buf, buflen);
723 tcp_sw_conn->sendpage = conn->datadgst_en ?
724 sock_no_sendpage : tcp_sw_conn->sock->ops->sendpage;
725 break;
726 case ISCSI_PARAM_MAX_R2T:
727 return iscsi_tcp_set_max_r2t(conn, buf);
728 default:
729 return iscsi_set_param(cls_conn, param, buf, buflen);
730 }
731
732 return 0;
733 }
734
iscsi_sw_tcp_conn_get_param(struct iscsi_cls_conn * cls_conn,enum iscsi_param param,char * buf)735 static int iscsi_sw_tcp_conn_get_param(struct iscsi_cls_conn *cls_conn,
736 enum iscsi_param param, char *buf)
737 {
738 struct iscsi_conn *conn = cls_conn->dd_data;
739 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
740 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
741 struct sockaddr_in6 addr;
742 int rc, len;
743
744 switch(param) {
745 case ISCSI_PARAM_CONN_PORT:
746 case ISCSI_PARAM_CONN_ADDRESS:
747 case ISCSI_PARAM_LOCAL_PORT:
748 spin_lock_bh(&conn->session->frwd_lock);
749 if (!tcp_sw_conn || !tcp_sw_conn->sock) {
750 spin_unlock_bh(&conn->session->frwd_lock);
751 return -ENOTCONN;
752 }
753 if (param == ISCSI_PARAM_LOCAL_PORT)
754 rc = kernel_getsockname(tcp_sw_conn->sock,
755 (struct sockaddr *)&addr, &len);
756 else
757 rc = kernel_getpeername(tcp_sw_conn->sock,
758 (struct sockaddr *)&addr, &len);
759 spin_unlock_bh(&conn->session->frwd_lock);
760 if (rc)
761 return rc;
762
763 return iscsi_conn_get_addr_param((struct sockaddr_storage *)
764 &addr, param, buf);
765 default:
766 return iscsi_conn_get_param(cls_conn, param, buf);
767 }
768
769 return 0;
770 }
771
iscsi_sw_tcp_host_get_param(struct Scsi_Host * shost,enum iscsi_host_param param,char * buf)772 static int iscsi_sw_tcp_host_get_param(struct Scsi_Host *shost,
773 enum iscsi_host_param param, char *buf)
774 {
775 struct iscsi_sw_tcp_host *tcp_sw_host = iscsi_host_priv(shost);
776 struct iscsi_session *session = tcp_sw_host->session;
777 struct iscsi_conn *conn;
778 struct iscsi_tcp_conn *tcp_conn;
779 struct iscsi_sw_tcp_conn *tcp_sw_conn;
780 struct sockaddr_in6 addr;
781 int rc, len;
782
783 switch (param) {
784 case ISCSI_HOST_PARAM_IPADDRESS:
785 if (!session)
786 return -ENOTCONN;
787
788 spin_lock_bh(&session->frwd_lock);
789 conn = session->leadconn;
790 if (!conn) {
791 spin_unlock_bh(&session->frwd_lock);
792 return -ENOTCONN;
793 }
794 tcp_conn = conn->dd_data;
795
796 tcp_sw_conn = tcp_conn->dd_data;
797 if (!tcp_sw_conn->sock) {
798 spin_unlock_bh(&session->frwd_lock);
799 return -ENOTCONN;
800 }
801
802 rc = kernel_getsockname(tcp_sw_conn->sock,
803 (struct sockaddr *)&addr, &len);
804 spin_unlock_bh(&session->frwd_lock);
805 if (rc)
806 return rc;
807
808 return iscsi_conn_get_addr_param((struct sockaddr_storage *)
809 &addr,
810 (enum iscsi_param)param, buf);
811 default:
812 return iscsi_host_get_param(shost, param, buf);
813 }
814
815 return 0;
816 }
817
818 static void
iscsi_sw_tcp_conn_get_stats(struct iscsi_cls_conn * cls_conn,struct iscsi_stats * stats)819 iscsi_sw_tcp_conn_get_stats(struct iscsi_cls_conn *cls_conn,
820 struct iscsi_stats *stats)
821 {
822 struct iscsi_conn *conn = cls_conn->dd_data;
823 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
824 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
825
826 stats->custom_length = 3;
827 strcpy(stats->custom[0].desc, "tx_sendpage_failures");
828 stats->custom[0].value = tcp_sw_conn->sendpage_failures_cnt;
829 strcpy(stats->custom[1].desc, "rx_discontiguous_hdr");
830 stats->custom[1].value = tcp_sw_conn->discontiguous_hdr_cnt;
831 strcpy(stats->custom[2].desc, "eh_abort_cnt");
832 stats->custom[2].value = conn->eh_abort_cnt;
833
834 iscsi_tcp_conn_get_stats(cls_conn, stats);
835 }
836
837 static struct iscsi_cls_session *
iscsi_sw_tcp_session_create(struct iscsi_endpoint * ep,uint16_t cmds_max,uint16_t qdepth,uint32_t initial_cmdsn)838 iscsi_sw_tcp_session_create(struct iscsi_endpoint *ep, uint16_t cmds_max,
839 uint16_t qdepth, uint32_t initial_cmdsn)
840 {
841 struct iscsi_cls_session *cls_session;
842 struct iscsi_session *session;
843 struct iscsi_sw_tcp_host *tcp_sw_host;
844 struct Scsi_Host *shost;
845
846 if (ep) {
847 printk(KERN_ERR "iscsi_tcp: invalid ep %p.\n", ep);
848 return NULL;
849 }
850
851 shost = iscsi_host_alloc(&iscsi_sw_tcp_sht,
852 sizeof(struct iscsi_sw_tcp_host), 1);
853 if (!shost)
854 return NULL;
855 shost->transportt = iscsi_sw_tcp_scsi_transport;
856 shost->cmd_per_lun = qdepth;
857 shost->max_lun = iscsi_max_lun;
858 shost->max_id = 0;
859 shost->max_channel = 0;
860 shost->max_cmd_len = SCSI_MAX_VARLEN_CDB_SIZE;
861
862 if (iscsi_host_add(shost, NULL))
863 goto free_host;
864
865 cls_session = iscsi_session_setup(&iscsi_sw_tcp_transport, shost,
866 cmds_max, 0,
867 sizeof(struct iscsi_tcp_task) +
868 sizeof(struct iscsi_sw_tcp_hdrbuf),
869 initial_cmdsn, 0);
870 if (!cls_session)
871 goto remove_host;
872 session = cls_session->dd_data;
873 tcp_sw_host = iscsi_host_priv(shost);
874 tcp_sw_host->session = session;
875
876 shost->can_queue = session->scsi_cmds_max;
877 if (iscsi_tcp_r2tpool_alloc(session))
878 goto remove_session;
879 return cls_session;
880
881 remove_session:
882 iscsi_session_teardown(cls_session);
883 remove_host:
884 iscsi_host_remove(shost);
885 free_host:
886 iscsi_host_free(shost);
887 return NULL;
888 }
889
iscsi_sw_tcp_session_destroy(struct iscsi_cls_session * cls_session)890 static void iscsi_sw_tcp_session_destroy(struct iscsi_cls_session *cls_session)
891 {
892 struct Scsi_Host *shost = iscsi_session_to_shost(cls_session);
893 struct iscsi_session *session = cls_session->dd_data;
894
895 if (WARN_ON_ONCE(session->leadconn))
896 return;
897
898 iscsi_tcp_r2tpool_free(cls_session->dd_data);
899 iscsi_session_teardown(cls_session);
900
901 iscsi_host_remove(shost);
902 iscsi_host_free(shost);
903 }
904
iscsi_sw_tcp_attr_is_visible(int param_type,int param)905 static umode_t iscsi_sw_tcp_attr_is_visible(int param_type, int param)
906 {
907 switch (param_type) {
908 case ISCSI_HOST_PARAM:
909 switch (param) {
910 case ISCSI_HOST_PARAM_NETDEV_NAME:
911 case ISCSI_HOST_PARAM_HWADDRESS:
912 case ISCSI_HOST_PARAM_IPADDRESS:
913 case ISCSI_HOST_PARAM_INITIATOR_NAME:
914 return S_IRUGO;
915 default:
916 return 0;
917 }
918 case ISCSI_PARAM:
919 switch (param) {
920 case ISCSI_PARAM_MAX_RECV_DLENGTH:
921 case ISCSI_PARAM_MAX_XMIT_DLENGTH:
922 case ISCSI_PARAM_HDRDGST_EN:
923 case ISCSI_PARAM_DATADGST_EN:
924 case ISCSI_PARAM_CONN_ADDRESS:
925 case ISCSI_PARAM_CONN_PORT:
926 case ISCSI_PARAM_LOCAL_PORT:
927 case ISCSI_PARAM_EXP_STATSN:
928 case ISCSI_PARAM_PERSISTENT_ADDRESS:
929 case ISCSI_PARAM_PERSISTENT_PORT:
930 case ISCSI_PARAM_PING_TMO:
931 case ISCSI_PARAM_RECV_TMO:
932 case ISCSI_PARAM_INITIAL_R2T_EN:
933 case ISCSI_PARAM_MAX_R2T:
934 case ISCSI_PARAM_IMM_DATA_EN:
935 case ISCSI_PARAM_FIRST_BURST:
936 case ISCSI_PARAM_MAX_BURST:
937 case ISCSI_PARAM_PDU_INORDER_EN:
938 case ISCSI_PARAM_DATASEQ_INORDER_EN:
939 case ISCSI_PARAM_ERL:
940 case ISCSI_PARAM_TARGET_NAME:
941 case ISCSI_PARAM_TPGT:
942 case ISCSI_PARAM_USERNAME:
943 case ISCSI_PARAM_PASSWORD:
944 case ISCSI_PARAM_USERNAME_IN:
945 case ISCSI_PARAM_PASSWORD_IN:
946 case ISCSI_PARAM_FAST_ABORT:
947 case ISCSI_PARAM_ABORT_TMO:
948 case ISCSI_PARAM_LU_RESET_TMO:
949 case ISCSI_PARAM_TGT_RESET_TMO:
950 case ISCSI_PARAM_IFACE_NAME:
951 case ISCSI_PARAM_INITIATOR_NAME:
952 return S_IRUGO;
953 default:
954 return 0;
955 }
956 }
957
958 return 0;
959 }
960
iscsi_sw_tcp_slave_alloc(struct scsi_device * sdev)961 static int iscsi_sw_tcp_slave_alloc(struct scsi_device *sdev)
962 {
963 set_bit(QUEUE_FLAG_BIDI, &sdev->request_queue->queue_flags);
964 return 0;
965 }
966
iscsi_sw_tcp_slave_configure(struct scsi_device * sdev)967 static int iscsi_sw_tcp_slave_configure(struct scsi_device *sdev)
968 {
969 struct iscsi_sw_tcp_host *tcp_sw_host = iscsi_host_priv(sdev->host);
970 struct iscsi_session *session = tcp_sw_host->session;
971 struct iscsi_conn *conn = session->leadconn;
972
973 if (conn->datadgst_en)
974 sdev->request_queue->backing_dev_info->capabilities
975 |= BDI_CAP_STABLE_WRITES;
976 blk_queue_bounce_limit(sdev->request_queue, BLK_BOUNCE_ANY);
977 blk_queue_dma_alignment(sdev->request_queue, 0);
978 return 0;
979 }
980
981 static struct scsi_host_template iscsi_sw_tcp_sht = {
982 .module = THIS_MODULE,
983 .name = "iSCSI Initiator over TCP/IP",
984 .queuecommand = iscsi_queuecommand,
985 .change_queue_depth = scsi_change_queue_depth,
986 .can_queue = ISCSI_DEF_XMIT_CMDS_MAX - 1,
987 .sg_tablesize = 4096,
988 .max_sectors = 0xFFFF,
989 .cmd_per_lun = ISCSI_DEF_CMD_PER_LUN,
990 .eh_timed_out = iscsi_eh_cmd_timed_out,
991 .eh_abort_handler = iscsi_eh_abort,
992 .eh_device_reset_handler= iscsi_eh_device_reset,
993 .eh_target_reset_handler = iscsi_eh_recover_target,
994 .use_clustering = DISABLE_CLUSTERING,
995 .slave_alloc = iscsi_sw_tcp_slave_alloc,
996 .slave_configure = iscsi_sw_tcp_slave_configure,
997 .target_alloc = iscsi_target_alloc,
998 .proc_name = "iscsi_tcp",
999 .this_id = -1,
1000 .track_queue_depth = 1,
1001 };
1002
1003 static struct iscsi_transport iscsi_sw_tcp_transport = {
1004 .owner = THIS_MODULE,
1005 .name = "tcp",
1006 .caps = CAP_RECOVERY_L0 | CAP_MULTI_R2T | CAP_HDRDGST
1007 | CAP_DATADGST,
1008 /* session management */
1009 .create_session = iscsi_sw_tcp_session_create,
1010 .destroy_session = iscsi_sw_tcp_session_destroy,
1011 /* connection management */
1012 .create_conn = iscsi_sw_tcp_conn_create,
1013 .bind_conn = iscsi_sw_tcp_conn_bind,
1014 .destroy_conn = iscsi_sw_tcp_conn_destroy,
1015 .attr_is_visible = iscsi_sw_tcp_attr_is_visible,
1016 .set_param = iscsi_sw_tcp_conn_set_param,
1017 .get_conn_param = iscsi_sw_tcp_conn_get_param,
1018 .get_session_param = iscsi_session_get_param,
1019 .start_conn = iscsi_conn_start,
1020 .stop_conn = iscsi_sw_tcp_conn_stop,
1021 /* iscsi host params */
1022 .get_host_param = iscsi_sw_tcp_host_get_param,
1023 .set_host_param = iscsi_host_set_param,
1024 /* IO */
1025 .send_pdu = iscsi_conn_send_pdu,
1026 .get_stats = iscsi_sw_tcp_conn_get_stats,
1027 /* iscsi task/cmd helpers */
1028 .init_task = iscsi_tcp_task_init,
1029 .xmit_task = iscsi_tcp_task_xmit,
1030 .cleanup_task = iscsi_tcp_cleanup_task,
1031 /* low level pdu helpers */
1032 .xmit_pdu = iscsi_sw_tcp_pdu_xmit,
1033 .init_pdu = iscsi_sw_tcp_pdu_init,
1034 .alloc_pdu = iscsi_sw_tcp_pdu_alloc,
1035 /* recovery */
1036 .session_recovery_timedout = iscsi_session_recovery_timedout,
1037 };
1038
iscsi_sw_tcp_init(void)1039 static int __init iscsi_sw_tcp_init(void)
1040 {
1041 if (iscsi_max_lun < 1) {
1042 printk(KERN_ERR "iscsi_tcp: Invalid max_lun value of %u\n",
1043 iscsi_max_lun);
1044 return -EINVAL;
1045 }
1046
1047 iscsi_sw_tcp_scsi_transport = iscsi_register_transport(
1048 &iscsi_sw_tcp_transport);
1049 if (!iscsi_sw_tcp_scsi_transport)
1050 return -ENODEV;
1051
1052 return 0;
1053 }
1054
iscsi_sw_tcp_exit(void)1055 static void __exit iscsi_sw_tcp_exit(void)
1056 {
1057 iscsi_unregister_transport(&iscsi_sw_tcp_transport);
1058 }
1059
1060 module_init(iscsi_sw_tcp_init);
1061 module_exit(iscsi_sw_tcp_exit);
1062