1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * iSCSI over TCP/IP Data-Path lib
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 * Credits:
12 * Christoph Hellwig
13 * FUJITA Tomonori
14 * Arne Redlich
15 * Zhenyu Wang
16 */
17
18 #include <linux/crc32c.h>
19 #include <linux/types.h>
20 #include <linux/list.h>
21 #include <linux/inet.h>
22 #include <linux/slab.h>
23 #include <linux/file.h>
24 #include <linux/blkdev.h>
25 #include <linux/delay.h>
26 #include <linux/kfifo.h>
27 #include <linux/scatterlist.h>
28 #include <linux/module.h>
29 #include <net/tcp.h>
30 #include <scsi/scsi_cmnd.h>
31 #include <scsi/scsi_device.h>
32 #include <scsi/scsi_host.h>
33 #include <scsi/scsi.h>
34 #include <scsi/scsi_transport_iscsi.h>
35 #include <trace/events/iscsi.h>
36
37 #include "iscsi_tcp.h"
38
39 MODULE_AUTHOR("Mike Christie <michaelc@cs.wisc.edu>, "
40 "Dmitry Yusupov <dmitry_yus@yahoo.com>, "
41 "Alex Aizman <itn780@yahoo.com>");
42 MODULE_DESCRIPTION("iSCSI/TCP data-path");
43 MODULE_LICENSE("GPL");
44
45 static int iscsi_dbg_libtcp;
46 module_param_named(debug_libiscsi_tcp, iscsi_dbg_libtcp, int,
47 S_IRUGO | S_IWUSR);
48 MODULE_PARM_DESC(debug_libiscsi_tcp, "Turn on debugging for libiscsi_tcp "
49 "module. Set to 1 to turn on, and zero to turn off. Default "
50 "is off.");
51
52 #define ISCSI_DBG_TCP(_conn, dbg_fmt, arg...) \
53 do { \
54 if (iscsi_dbg_libtcp) \
55 iscsi_conn_printk(KERN_INFO, _conn, \
56 "%s " dbg_fmt, \
57 __func__, ##arg); \
58 iscsi_dbg_trace(trace_iscsi_dbg_tcp, \
59 &(_conn)->cls_conn->dev, \
60 "%s " dbg_fmt, __func__, ##arg);\
61 } while (0);
62
63 static int iscsi_tcp_hdr_recv_done(struct iscsi_tcp_conn *tcp_conn,
64 struct iscsi_segment *segment);
65
66 /*
67 * Scatterlist handling: inside the iscsi_segment, we
68 * remember an index into the scatterlist, and set data/size
69 * to the current scatterlist entry. For highmem pages, we
70 * kmap as needed.
71 *
72 * Note that the page is unmapped when we return from
73 * TCP's data_ready handler, so we may end up mapping and
74 * unmapping the same page repeatedly. The whole reason
75 * for this is that we shouldn't keep the page mapped
76 * outside the softirq.
77 */
78
79 /**
80 * iscsi_tcp_segment_init_sg - init indicated scatterlist entry
81 * @segment: the buffer object
82 * @sg: scatterlist
83 * @offset: byte offset into that sg entry
84 *
85 * This function sets up the segment so that subsequent
86 * data is copied to the indicated sg entry, at the given
87 * offset.
88 */
89 static inline void
iscsi_tcp_segment_init_sg(struct iscsi_segment * segment,struct scatterlist * sg,unsigned int offset)90 iscsi_tcp_segment_init_sg(struct iscsi_segment *segment,
91 struct scatterlist *sg, unsigned int offset)
92 {
93 segment->sg = sg;
94 segment->sg_offset = offset;
95 segment->size = min(sg->length - offset,
96 segment->total_size - segment->total_copied);
97 segment->data = NULL;
98 }
99
100 /**
101 * iscsi_tcp_segment_map - map the current S/G page
102 * @segment: iscsi_segment
103 * @recv: 1 if called from recv path
104 *
105 * We only need to possibly kmap data if scatter lists are being used,
106 * because the iscsi passthrough and internal IO paths will never use high
107 * mem pages.
108 */
iscsi_tcp_segment_map(struct iscsi_segment * segment,int recv)109 static void iscsi_tcp_segment_map(struct iscsi_segment *segment, int recv)
110 {
111 struct scatterlist *sg;
112
113 if (segment->data != NULL || !segment->sg)
114 return;
115
116 sg = segment->sg;
117 BUG_ON(segment->sg_mapped);
118 BUG_ON(sg->length == 0);
119
120 /*
121 * We always map for the recv path.
122 *
123 * If the page count is greater than one it is ok to send
124 * to the network layer's zero copy send path. If not we
125 * have to go the slow sendmsg path.
126 *
127 * Same goes for slab pages: skb_can_coalesce() allows
128 * coalescing neighboring slab objects into a single frag which
129 * triggers one of hardened usercopy checks.
130 */
131 if (!recv && sendpage_ok(sg_page(sg)))
132 return;
133
134 if (recv) {
135 segment->atomic_mapped = true;
136 segment->sg_mapped = kmap_atomic(sg_page(sg));
137 } else {
138 segment->atomic_mapped = false;
139 /* the xmit path can sleep with the page mapped so use kmap */
140 segment->sg_mapped = kmap(sg_page(sg));
141 }
142
143 segment->data = segment->sg_mapped + sg->offset + segment->sg_offset;
144 }
145
iscsi_tcp_segment_unmap(struct iscsi_segment * segment)146 void iscsi_tcp_segment_unmap(struct iscsi_segment *segment)
147 {
148 if (segment->sg_mapped) {
149 if (segment->atomic_mapped)
150 kunmap_atomic(segment->sg_mapped);
151 else
152 kunmap(sg_page(segment->sg));
153 segment->sg_mapped = NULL;
154 segment->data = NULL;
155 }
156 }
157 EXPORT_SYMBOL_GPL(iscsi_tcp_segment_unmap);
158
159 /*
160 * Splice the digest buffer into the buffer
161 */
162 static inline void
iscsi_tcp_segment_splice_digest(struct iscsi_segment * segment,void * digest)163 iscsi_tcp_segment_splice_digest(struct iscsi_segment *segment, void *digest)
164 {
165 segment->data = digest;
166 segment->digest_len = ISCSI_DIGEST_SIZE;
167 segment->total_size += ISCSI_DIGEST_SIZE;
168 segment->size = ISCSI_DIGEST_SIZE;
169 segment->copied = 0;
170 segment->sg = NULL;
171 segment->crcp = NULL;
172 }
173
174 /**
175 * iscsi_tcp_segment_done - check whether the segment is complete
176 * @tcp_conn: iscsi tcp connection
177 * @segment: iscsi segment to check
178 * @recv: set to one of this is called from the recv path
179 * @copied: number of bytes copied
180 *
181 * Check if we're done receiving this segment. If the receive
182 * buffer is full but we expect more data, move on to the
183 * next entry in the scatterlist.
184 *
185 * If the amount of data we received isn't a multiple of 4,
186 * we will transparently receive the pad bytes, too.
187 *
188 * This function must be re-entrant.
189 */
iscsi_tcp_segment_done(struct iscsi_tcp_conn * tcp_conn,struct iscsi_segment * segment,int recv,unsigned copied)190 int iscsi_tcp_segment_done(struct iscsi_tcp_conn *tcp_conn,
191 struct iscsi_segment *segment, int recv,
192 unsigned copied)
193 {
194 unsigned int pad;
195
196 ISCSI_DBG_TCP(tcp_conn->iscsi_conn, "copied %u %u size %u %s\n",
197 segment->copied, copied, segment->size,
198 recv ? "recv" : "xmit");
199 if (segment->crcp && copied) {
200 if (segment->data) {
201 *segment->crcp = crc32c(*segment->crcp,
202 segment->data + segment->copied,
203 copied);
204 } else {
205 const void *data;
206
207 data = kmap_local_page(sg_page(segment->sg));
208 *segment->crcp = crc32c(*segment->crcp,
209 data + segment->copied +
210 segment->sg_offset +
211 segment->sg->offset,
212 copied);
213 kunmap_local(data);
214 }
215 }
216
217 segment->copied += copied;
218 if (segment->copied < segment->size) {
219 iscsi_tcp_segment_map(segment, recv);
220 return 0;
221 }
222
223 segment->total_copied += segment->copied;
224 segment->copied = 0;
225 segment->size = 0;
226
227 /* Unmap the current scatterlist page, if there is one. */
228 iscsi_tcp_segment_unmap(segment);
229
230 /* Do we have more scatterlist entries? */
231 ISCSI_DBG_TCP(tcp_conn->iscsi_conn, "total copied %u total size %u\n",
232 segment->total_copied, segment->total_size);
233 if (segment->total_copied < segment->total_size) {
234 /* Proceed to the next entry in the scatterlist. */
235 iscsi_tcp_segment_init_sg(segment, sg_next(segment->sg),
236 0);
237 iscsi_tcp_segment_map(segment, recv);
238 BUG_ON(segment->size == 0);
239 return 0;
240 }
241
242 /* Do we need to handle padding? */
243 if (!(tcp_conn->iscsi_conn->session->tt->caps & CAP_PADDING_OFFLOAD)) {
244 pad = iscsi_padding(segment->total_copied);
245 if (pad != 0) {
246 ISCSI_DBG_TCP(tcp_conn->iscsi_conn,
247 "consume %d pad bytes\n", pad);
248 segment->total_size += pad;
249 segment->size = pad;
250 segment->data = segment->padbuf;
251 return 0;
252 }
253 }
254
255 /*
256 * Set us up for transferring the data digest. hdr digest
257 * is completely handled in hdr done function.
258 */
259 if (segment->crcp) {
260 put_unaligned_le32(~*segment->crcp, segment->digest);
261 iscsi_tcp_segment_splice_digest(segment,
262 recv ? segment->recv_digest : segment->digest);
263 return 0;
264 }
265
266 return 1;
267 }
268 EXPORT_SYMBOL_GPL(iscsi_tcp_segment_done);
269
270 /**
271 * iscsi_tcp_segment_recv - copy data to segment
272 * @tcp_conn: the iSCSI TCP connection
273 * @segment: the buffer to copy to
274 * @ptr: data pointer
275 * @len: amount of data available
276 *
277 * This function copies up to @len bytes to the
278 * given buffer, and returns the number of bytes
279 * consumed, which can actually be less than @len.
280 *
281 * If CRC is enabled, the function will update the CRC while copying.
282 * Combining these two operations doesn't buy us a lot (yet),
283 * but in the future we could implement combined copy+crc,
284 * just way we do for network layer checksums.
285 */
286 static int
iscsi_tcp_segment_recv(struct iscsi_tcp_conn * tcp_conn,struct iscsi_segment * segment,const void * ptr,unsigned int len)287 iscsi_tcp_segment_recv(struct iscsi_tcp_conn *tcp_conn,
288 struct iscsi_segment *segment, const void *ptr,
289 unsigned int len)
290 {
291 unsigned int copy = 0, copied = 0;
292
293 while (!iscsi_tcp_segment_done(tcp_conn, segment, 1, copy)) {
294 if (copied == len) {
295 ISCSI_DBG_TCP(tcp_conn->iscsi_conn,
296 "copied %d bytes\n", len);
297 break;
298 }
299
300 copy = min(len - copied, segment->size - segment->copied);
301 ISCSI_DBG_TCP(tcp_conn->iscsi_conn, "copying %d\n", copy);
302 memcpy(segment->data + segment->copied, ptr + copied, copy);
303 copied += copy;
304 }
305 return copied;
306 }
307
308 inline void
iscsi_tcp_dgst_header(const void * hdr,size_t hdrlen,unsigned char digest[ISCSI_DIGEST_SIZE])309 iscsi_tcp_dgst_header(const void *hdr, size_t hdrlen,
310 unsigned char digest[ISCSI_DIGEST_SIZE])
311 {
312 put_unaligned_le32(~crc32c(~0, hdr, hdrlen), digest);
313 }
314 EXPORT_SYMBOL_GPL(iscsi_tcp_dgst_header);
315
316 static inline int
iscsi_tcp_dgst_verify(struct iscsi_tcp_conn * tcp_conn,struct iscsi_segment * segment)317 iscsi_tcp_dgst_verify(struct iscsi_tcp_conn *tcp_conn,
318 struct iscsi_segment *segment)
319 {
320 if (!segment->digest_len)
321 return 1;
322
323 if (memcmp(segment->recv_digest, segment->digest,
324 segment->digest_len)) {
325 ISCSI_DBG_TCP(tcp_conn->iscsi_conn, "digest mismatch\n");
326 return 0;
327 }
328
329 return 1;
330 }
331
332 /*
333 * Helper function to set up segment buffer
334 */
335 static inline void
__iscsi_segment_init(struct iscsi_segment * segment,size_t size,iscsi_segment_done_fn_t * done,u32 * crcp)336 __iscsi_segment_init(struct iscsi_segment *segment, size_t size,
337 iscsi_segment_done_fn_t *done, u32 *crcp)
338 {
339 memset(segment, 0, sizeof(*segment));
340 segment->total_size = size;
341 segment->done = done;
342
343 if (crcp) {
344 segment->crcp = crcp;
345 *crcp = ~0;
346 }
347 }
348
349 inline void
iscsi_segment_init_linear(struct iscsi_segment * segment,void * data,size_t size,iscsi_segment_done_fn_t * done,u32 * crcp)350 iscsi_segment_init_linear(struct iscsi_segment *segment, void *data,
351 size_t size, iscsi_segment_done_fn_t *done, u32 *crcp)
352 {
353 __iscsi_segment_init(segment, size, done, crcp);
354 segment->data = data;
355 segment->size = size;
356 }
357 EXPORT_SYMBOL_GPL(iscsi_segment_init_linear);
358
359 inline int
iscsi_segment_seek_sg(struct iscsi_segment * segment,struct scatterlist * sg_list,unsigned int sg_count,unsigned int offset,size_t size,iscsi_segment_done_fn_t * done,u32 * crcp)360 iscsi_segment_seek_sg(struct iscsi_segment *segment,
361 struct scatterlist *sg_list, unsigned int sg_count,
362 unsigned int offset, size_t size,
363 iscsi_segment_done_fn_t *done, u32 *crcp)
364 {
365 struct scatterlist *sg;
366 unsigned int i;
367
368 __iscsi_segment_init(segment, size, done, crcp);
369 for_each_sg(sg_list, sg, sg_count, i) {
370 if (offset < sg->length) {
371 iscsi_tcp_segment_init_sg(segment, sg, offset);
372 return 0;
373 }
374 offset -= sg->length;
375 }
376
377 return ISCSI_ERR_DATA_OFFSET;
378 }
379 EXPORT_SYMBOL_GPL(iscsi_segment_seek_sg);
380
381 /**
382 * iscsi_tcp_hdr_recv_prep - prep segment for hdr reception
383 * @tcp_conn: iscsi connection to prep for
384 *
385 * This function always passes NULL for the crcp argument, because when this
386 * function is called we do not yet know the final size of the header and want
387 * to delay the digest processing until we know that.
388 */
iscsi_tcp_hdr_recv_prep(struct iscsi_tcp_conn * tcp_conn)389 void iscsi_tcp_hdr_recv_prep(struct iscsi_tcp_conn *tcp_conn)
390 {
391 ISCSI_DBG_TCP(tcp_conn->iscsi_conn,
392 "(%s)\n", tcp_conn->iscsi_conn->hdrdgst_en ?
393 "digest enabled" : "digest disabled");
394 iscsi_segment_init_linear(&tcp_conn->in.segment,
395 tcp_conn->in.hdr_buf, sizeof(struct iscsi_hdr),
396 iscsi_tcp_hdr_recv_done, NULL);
397 }
398 EXPORT_SYMBOL_GPL(iscsi_tcp_hdr_recv_prep);
399
400 /*
401 * Handle incoming reply to any other type of command
402 */
403 static int
iscsi_tcp_data_recv_done(struct iscsi_tcp_conn * tcp_conn,struct iscsi_segment * segment)404 iscsi_tcp_data_recv_done(struct iscsi_tcp_conn *tcp_conn,
405 struct iscsi_segment *segment)
406 {
407 struct iscsi_conn *conn = tcp_conn->iscsi_conn;
408 int rc = 0;
409
410 if (!iscsi_tcp_dgst_verify(tcp_conn, segment))
411 return ISCSI_ERR_DATA_DGST;
412
413 rc = iscsi_complete_pdu(conn, tcp_conn->in.hdr,
414 conn->data, tcp_conn->in.datalen);
415 if (rc)
416 return rc;
417
418 iscsi_tcp_hdr_recv_prep(tcp_conn);
419 return 0;
420 }
421
422 static void
iscsi_tcp_data_recv_prep(struct iscsi_tcp_conn * tcp_conn)423 iscsi_tcp_data_recv_prep(struct iscsi_tcp_conn *tcp_conn)
424 {
425 struct iscsi_conn *conn = tcp_conn->iscsi_conn;
426 u32 *rx_crcp = NULL;
427
428 if (conn->datadgst_en &&
429 !(conn->session->tt->caps & CAP_DIGEST_OFFLOAD))
430 rx_crcp = tcp_conn->rx_crcp;
431
432 iscsi_segment_init_linear(&tcp_conn->in.segment,
433 conn->data, tcp_conn->in.datalen,
434 iscsi_tcp_data_recv_done, rx_crcp);
435 }
436
437 /**
438 * iscsi_tcp_cleanup_task - free tcp_task resources
439 * @task: iscsi task
440 *
441 * must be called with session back_lock
442 */
iscsi_tcp_cleanup_task(struct iscsi_task * task)443 void iscsi_tcp_cleanup_task(struct iscsi_task *task)
444 {
445 struct iscsi_tcp_task *tcp_task = task->dd_data;
446 struct iscsi_r2t_info *r2t;
447
448 /* nothing to do for mgmt */
449 if (!task->sc)
450 return;
451
452 spin_lock_bh(&tcp_task->queue2pool);
453 /* flush task's r2t queues */
454 while (kfifo_out(&tcp_task->r2tqueue, (void*)&r2t, sizeof(void*))) {
455 kfifo_in(&tcp_task->r2tpool.queue, (void*)&r2t,
456 sizeof(void*));
457 ISCSI_DBG_TCP(task->conn, "pending r2t dropped\n");
458 }
459
460 r2t = tcp_task->r2t;
461 if (r2t != NULL) {
462 kfifo_in(&tcp_task->r2tpool.queue, (void*)&r2t,
463 sizeof(void*));
464 tcp_task->r2t = NULL;
465 }
466 spin_unlock_bh(&tcp_task->queue2pool);
467 }
468 EXPORT_SYMBOL_GPL(iscsi_tcp_cleanup_task);
469
470 /**
471 * iscsi_tcp_data_in - SCSI Data-In Response processing
472 * @conn: iscsi connection
473 * @task: scsi command task
474 */
iscsi_tcp_data_in(struct iscsi_conn * conn,struct iscsi_task * task)475 static int iscsi_tcp_data_in(struct iscsi_conn *conn, struct iscsi_task *task)
476 {
477 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
478 struct iscsi_tcp_task *tcp_task = task->dd_data;
479 struct iscsi_data_rsp *rhdr = (struct iscsi_data_rsp *)tcp_conn->in.hdr;
480 int datasn = be32_to_cpu(rhdr->datasn);
481 unsigned total_in_length = task->sc->sdb.length;
482
483 /*
484 * lib iscsi will update this in the completion handling if there
485 * is status.
486 */
487 if (!(rhdr->flags & ISCSI_FLAG_DATA_STATUS))
488 iscsi_update_cmdsn(conn->session, (struct iscsi_nopin*)rhdr);
489
490 if (tcp_conn->in.datalen == 0)
491 return 0;
492
493 if (tcp_task->exp_datasn != datasn) {
494 ISCSI_DBG_TCP(conn, "task->exp_datasn(%d) != rhdr->datasn(%d)"
495 "\n", tcp_task->exp_datasn, datasn);
496 return ISCSI_ERR_DATASN;
497 }
498
499 tcp_task->exp_datasn++;
500
501 tcp_task->data_offset = be32_to_cpu(rhdr->offset);
502 if (tcp_task->data_offset + tcp_conn->in.datalen > total_in_length) {
503 ISCSI_DBG_TCP(conn, "data_offset(%d) + data_len(%d) > "
504 "total_length_in(%d)\n", tcp_task->data_offset,
505 tcp_conn->in.datalen, total_in_length);
506 return ISCSI_ERR_DATA_OFFSET;
507 }
508
509 conn->datain_pdus_cnt++;
510 return 0;
511 }
512
513 /**
514 * iscsi_tcp_r2t_rsp - iSCSI R2T Response processing
515 * @conn: iscsi connection
516 * @hdr: PDU header
517 */
iscsi_tcp_r2t_rsp(struct iscsi_conn * conn,struct iscsi_hdr * hdr)518 static int iscsi_tcp_r2t_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr)
519 {
520 struct iscsi_session *session = conn->session;
521 struct iscsi_tcp_task *tcp_task;
522 struct iscsi_tcp_conn *tcp_conn;
523 struct iscsi_r2t_rsp *rhdr;
524 struct iscsi_r2t_info *r2t;
525 struct iscsi_task *task;
526 u32 data_length;
527 u32 data_offset;
528 int r2tsn;
529 int rc;
530
531 spin_lock(&session->back_lock);
532 task = iscsi_itt_to_ctask(conn, hdr->itt);
533 if (!task) {
534 spin_unlock(&session->back_lock);
535 return ISCSI_ERR_BAD_ITT;
536 } else if (task->sc->sc_data_direction != DMA_TO_DEVICE) {
537 spin_unlock(&session->back_lock);
538 return ISCSI_ERR_PROTO;
539 }
540 /*
541 * A bad target might complete the cmd before we have handled R2Ts
542 * so get a ref to the task that will be dropped in the xmit path.
543 */
544 if (task->state != ISCSI_TASK_RUNNING) {
545 spin_unlock(&session->back_lock);
546 /* Let the path that got the early rsp complete it */
547 return 0;
548 }
549 task->last_xfer = jiffies;
550 if (!iscsi_get_task(task)) {
551 spin_unlock(&session->back_lock);
552 /* Let the path that got the early rsp complete it */
553 return 0;
554 }
555
556 tcp_conn = conn->dd_data;
557 rhdr = (struct iscsi_r2t_rsp *)tcp_conn->in.hdr;
558 /* fill-in new R2T associated with the task */
559 iscsi_update_cmdsn(session, (struct iscsi_nopin *)rhdr);
560 spin_unlock(&session->back_lock);
561
562 if (tcp_conn->in.datalen) {
563 iscsi_conn_printk(KERN_ERR, conn,
564 "invalid R2t with datalen %d\n",
565 tcp_conn->in.datalen);
566 rc = ISCSI_ERR_DATALEN;
567 goto put_task;
568 }
569
570 tcp_task = task->dd_data;
571 r2tsn = be32_to_cpu(rhdr->r2tsn);
572 if (tcp_task->exp_datasn != r2tsn){
573 ISCSI_DBG_TCP(conn, "task->exp_datasn(%d) != rhdr->r2tsn(%d)\n",
574 tcp_task->exp_datasn, r2tsn);
575 rc = ISCSI_ERR_R2TSN;
576 goto put_task;
577 }
578
579 if (session->state != ISCSI_STATE_LOGGED_IN) {
580 iscsi_conn_printk(KERN_INFO, conn,
581 "dropping R2T itt %d in recovery.\n",
582 task->itt);
583 rc = 0;
584 goto put_task;
585 }
586
587 data_length = be32_to_cpu(rhdr->data_length);
588 if (data_length == 0) {
589 iscsi_conn_printk(KERN_ERR, conn,
590 "invalid R2T with zero data len\n");
591 rc = ISCSI_ERR_DATALEN;
592 goto put_task;
593 }
594
595 if (data_length > session->max_burst)
596 ISCSI_DBG_TCP(conn, "invalid R2T with data len %u and max "
597 "burst %u. Attempting to execute request.\n",
598 data_length, session->max_burst);
599
600 data_offset = be32_to_cpu(rhdr->data_offset);
601 if (data_offset + data_length > task->sc->sdb.length) {
602 iscsi_conn_printk(KERN_ERR, conn,
603 "invalid R2T with data len %u at offset %u "
604 "and total length %d\n", data_length,
605 data_offset, task->sc->sdb.length);
606 rc = ISCSI_ERR_DATALEN;
607 goto put_task;
608 }
609
610 spin_lock(&tcp_task->pool2queue);
611 rc = kfifo_out(&tcp_task->r2tpool.queue, (void *)&r2t, sizeof(void *));
612 if (!rc) {
613 iscsi_conn_printk(KERN_ERR, conn, "Could not allocate R2T. "
614 "Target has sent more R2Ts than it "
615 "negotiated for or driver has leaked.\n");
616 spin_unlock(&tcp_task->pool2queue);
617 rc = ISCSI_ERR_PROTO;
618 goto put_task;
619 }
620
621 r2t->exp_statsn = rhdr->statsn;
622 r2t->data_length = data_length;
623 r2t->data_offset = data_offset;
624
625 r2t->ttt = rhdr->ttt; /* no flip */
626 r2t->datasn = 0;
627 r2t->sent = 0;
628
629 tcp_task->exp_datasn = r2tsn + 1;
630 kfifo_in(&tcp_task->r2tqueue, (void*)&r2t, sizeof(void*));
631 conn->r2t_pdus_cnt++;
632 spin_unlock(&tcp_task->pool2queue);
633
634 iscsi_requeue_task(task);
635 return 0;
636
637 put_task:
638 iscsi_put_task(task);
639 return rc;
640 }
641
642 /*
643 * Handle incoming reply to DataIn command
644 */
645 static int
iscsi_tcp_process_data_in(struct iscsi_tcp_conn * tcp_conn,struct iscsi_segment * segment)646 iscsi_tcp_process_data_in(struct iscsi_tcp_conn *tcp_conn,
647 struct iscsi_segment *segment)
648 {
649 struct iscsi_conn *conn = tcp_conn->iscsi_conn;
650 struct iscsi_hdr *hdr = tcp_conn->in.hdr;
651 int rc;
652
653 if (!iscsi_tcp_dgst_verify(tcp_conn, segment))
654 return ISCSI_ERR_DATA_DGST;
655
656 /* check for non-exceptional status */
657 if (hdr->flags & ISCSI_FLAG_DATA_STATUS) {
658 rc = iscsi_complete_pdu(conn, tcp_conn->in.hdr, NULL, 0);
659 if (rc)
660 return rc;
661 }
662
663 iscsi_tcp_hdr_recv_prep(tcp_conn);
664 return 0;
665 }
666
667 /**
668 * iscsi_tcp_hdr_dissect - process PDU header
669 * @conn: iSCSI connection
670 * @hdr: PDU header
671 *
672 * This function analyzes the header of the PDU received,
673 * and performs several sanity checks. If the PDU is accompanied
674 * by data, the receive buffer is set up to copy the incoming data
675 * to the correct location.
676 */
677 static int
iscsi_tcp_hdr_dissect(struct iscsi_conn * conn,struct iscsi_hdr * hdr)678 iscsi_tcp_hdr_dissect(struct iscsi_conn *conn, struct iscsi_hdr *hdr)
679 {
680 int rc = 0, opcode, ahslen;
681 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
682 struct iscsi_task *task;
683
684 /* verify PDU length */
685 tcp_conn->in.datalen = ntoh24(hdr->dlength);
686 if (tcp_conn->in.datalen > conn->max_recv_dlength) {
687 iscsi_conn_printk(KERN_ERR, conn,
688 "iscsi_tcp: datalen %d > %d\n",
689 tcp_conn->in.datalen, conn->max_recv_dlength);
690 return ISCSI_ERR_DATALEN;
691 }
692
693 /* Additional header segments. So far, we don't
694 * process additional headers.
695 */
696 ahslen = hdr->hlength << 2;
697
698 opcode = hdr->opcode & ISCSI_OPCODE_MASK;
699 /* verify itt (itt encoding: age+cid+itt) */
700 rc = iscsi_verify_itt(conn, hdr->itt);
701 if (rc)
702 return rc;
703
704 ISCSI_DBG_TCP(conn, "opcode 0x%x ahslen %d datalen %d\n",
705 opcode, ahslen, tcp_conn->in.datalen);
706
707 switch(opcode) {
708 case ISCSI_OP_SCSI_DATA_IN:
709 spin_lock(&conn->session->back_lock);
710 task = iscsi_itt_to_ctask(conn, hdr->itt);
711 if (!task)
712 rc = ISCSI_ERR_BAD_ITT;
713 else
714 rc = iscsi_tcp_data_in(conn, task);
715 if (rc) {
716 spin_unlock(&conn->session->back_lock);
717 break;
718 }
719
720 if (tcp_conn->in.datalen) {
721 struct iscsi_tcp_task *tcp_task = task->dd_data;
722 u32 *rx_crcp = NULL;
723 struct scsi_data_buffer *sdb = &task->sc->sdb;
724
725 /*
726 * Setup copy of Data-In into the struct scsi_cmnd
727 * Scatterlist case:
728 * We set up the iscsi_segment to point to the next
729 * scatterlist entry to copy to. As we go along,
730 * we move on to the next scatterlist entry and
731 * update the digest per-entry.
732 */
733 if (conn->datadgst_en &&
734 !(conn->session->tt->caps & CAP_DIGEST_OFFLOAD))
735 rx_crcp = tcp_conn->rx_crcp;
736
737 ISCSI_DBG_TCP(conn, "iscsi_tcp_begin_data_in( "
738 "offset=%d, datalen=%d)\n",
739 tcp_task->data_offset,
740 tcp_conn->in.datalen);
741 task->last_xfer = jiffies;
742 rc = iscsi_segment_seek_sg(&tcp_conn->in.segment,
743 sdb->table.sgl,
744 sdb->table.nents,
745 tcp_task->data_offset,
746 tcp_conn->in.datalen,
747 iscsi_tcp_process_data_in,
748 rx_crcp);
749 spin_unlock(&conn->session->back_lock);
750 return rc;
751 }
752 rc = __iscsi_complete_pdu(conn, hdr, NULL, 0);
753 spin_unlock(&conn->session->back_lock);
754 break;
755 case ISCSI_OP_SCSI_CMD_RSP:
756 if (tcp_conn->in.datalen) {
757 iscsi_tcp_data_recv_prep(tcp_conn);
758 return 0;
759 }
760 rc = iscsi_complete_pdu(conn, hdr, NULL, 0);
761 break;
762 case ISCSI_OP_R2T:
763 if (ahslen) {
764 rc = ISCSI_ERR_AHSLEN;
765 break;
766 }
767 rc = iscsi_tcp_r2t_rsp(conn, hdr);
768 break;
769 case ISCSI_OP_LOGIN_RSP:
770 case ISCSI_OP_TEXT_RSP:
771 case ISCSI_OP_REJECT:
772 case ISCSI_OP_ASYNC_EVENT:
773 /*
774 * It is possible that we could get a PDU with a buffer larger
775 * than 8K, but there are no targets that currently do this.
776 * For now we fail until we find a vendor that needs it
777 */
778 if (ISCSI_DEF_MAX_RECV_SEG_LEN < tcp_conn->in.datalen) {
779 iscsi_conn_printk(KERN_ERR, conn,
780 "iscsi_tcp: received buffer of "
781 "len %u but conn buffer is only %u "
782 "(opcode %0x)\n",
783 tcp_conn->in.datalen,
784 ISCSI_DEF_MAX_RECV_SEG_LEN, opcode);
785 rc = ISCSI_ERR_PROTO;
786 break;
787 }
788
789 /* If there's data coming in with the response,
790 * receive it to the connection's buffer.
791 */
792 if (tcp_conn->in.datalen) {
793 iscsi_tcp_data_recv_prep(tcp_conn);
794 return 0;
795 }
796 fallthrough;
797 case ISCSI_OP_LOGOUT_RSP:
798 case ISCSI_OP_NOOP_IN:
799 case ISCSI_OP_SCSI_TMFUNC_RSP:
800 rc = iscsi_complete_pdu(conn, hdr, NULL, 0);
801 break;
802 default:
803 rc = ISCSI_ERR_BAD_OPCODE;
804 break;
805 }
806
807 if (rc == 0) {
808 /* Anything that comes with data should have
809 * been handled above. */
810 if (tcp_conn->in.datalen)
811 return ISCSI_ERR_PROTO;
812 iscsi_tcp_hdr_recv_prep(tcp_conn);
813 }
814
815 return rc;
816 }
817
818 /**
819 * iscsi_tcp_hdr_recv_done - process PDU header
820 * @tcp_conn: iSCSI TCP connection
821 * @segment: the buffer segment being processed
822 *
823 * This is the callback invoked when the PDU header has
824 * been received. If the header is followed by additional
825 * header segments, we go back for more data.
826 */
827 static int
iscsi_tcp_hdr_recv_done(struct iscsi_tcp_conn * tcp_conn,struct iscsi_segment * segment)828 iscsi_tcp_hdr_recv_done(struct iscsi_tcp_conn *tcp_conn,
829 struct iscsi_segment *segment)
830 {
831 struct iscsi_conn *conn = tcp_conn->iscsi_conn;
832 struct iscsi_hdr *hdr;
833
834 /* Check if there are additional header segments
835 * *prior* to computing the digest, because we
836 * may need to go back to the caller for more.
837 */
838 hdr = (struct iscsi_hdr *) tcp_conn->in.hdr_buf;
839 if (segment->copied == sizeof(struct iscsi_hdr) && hdr->hlength) {
840 /* Bump the header length - the caller will
841 * just loop around and get the AHS for us, and
842 * call again. */
843 unsigned int ahslen = hdr->hlength << 2;
844
845 /* Make sure we don't overflow */
846 if (sizeof(*hdr) + ahslen > sizeof(tcp_conn->in.hdr_buf))
847 return ISCSI_ERR_AHSLEN;
848
849 segment->total_size += ahslen;
850 segment->size += ahslen;
851 return 0;
852 }
853
854 /* We're done processing the header. See if we're doing
855 * header digests; if so, set up the recv_digest buffer
856 * and go back for more. */
857 if (conn->hdrdgst_en &&
858 !(conn->session->tt->caps & CAP_DIGEST_OFFLOAD)) {
859 if (segment->digest_len == 0) {
860 /*
861 * Even if we offload the digest processing we
862 * splice it in so we can increment the skb/segment
863 * counters in preparation for the data segment.
864 */
865 iscsi_tcp_segment_splice_digest(segment,
866 segment->recv_digest);
867 return 0;
868 }
869
870 iscsi_tcp_dgst_header(hdr,
871 segment->total_copied - ISCSI_DIGEST_SIZE,
872 segment->digest);
873
874 if (!iscsi_tcp_dgst_verify(tcp_conn, segment))
875 return ISCSI_ERR_HDR_DGST;
876 }
877
878 tcp_conn->in.hdr = hdr;
879 return iscsi_tcp_hdr_dissect(conn, hdr);
880 }
881
882 /**
883 * iscsi_tcp_recv_segment_is_hdr - tests if we are reading in a header
884 * @tcp_conn: iscsi tcp conn
885 *
886 * returns non zero if we are currently processing or setup to process
887 * a header.
888 */
iscsi_tcp_recv_segment_is_hdr(struct iscsi_tcp_conn * tcp_conn)889 inline int iscsi_tcp_recv_segment_is_hdr(struct iscsi_tcp_conn *tcp_conn)
890 {
891 return tcp_conn->in.segment.done == iscsi_tcp_hdr_recv_done;
892 }
893 EXPORT_SYMBOL_GPL(iscsi_tcp_recv_segment_is_hdr);
894
895 /**
896 * iscsi_tcp_recv_skb - Process skb
897 * @conn: iscsi connection
898 * @skb: network buffer with header and/or data segment
899 * @offset: offset in skb
900 * @offloaded: bool indicating if transfer was offloaded
901 * @status: iscsi TCP status result
902 *
903 * Will return status of transfer in @status. And will return
904 * number of bytes copied.
905 */
iscsi_tcp_recv_skb(struct iscsi_conn * conn,struct sk_buff * skb,unsigned int offset,bool offloaded,int * status)906 int iscsi_tcp_recv_skb(struct iscsi_conn *conn, struct sk_buff *skb,
907 unsigned int offset, bool offloaded, int *status)
908 {
909 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
910 struct iscsi_segment *segment = &tcp_conn->in.segment;
911 struct skb_seq_state seq;
912 unsigned int consumed = 0;
913 int rc = 0;
914
915 ISCSI_DBG_TCP(conn, "in %d bytes\n", skb->len - offset);
916 /*
917 * Update for each skb instead of pdu, because over slow networks a
918 * data_in's data could take a while to read in. We also want to
919 * account for r2ts.
920 */
921 conn->last_recv = jiffies;
922
923 if (unlikely(test_bit(ISCSI_CONN_FLAG_SUSPEND_RX, &conn->flags))) {
924 ISCSI_DBG_TCP(conn, "Rx suspended!\n");
925 *status = ISCSI_TCP_SUSPENDED;
926 return 0;
927 }
928
929 if (offloaded) {
930 segment->total_copied = segment->total_size;
931 goto segment_done;
932 }
933
934 skb_prepare_seq_read(skb, offset, skb->len, &seq);
935 while (1) {
936 unsigned int avail;
937 const u8 *ptr;
938
939 avail = skb_seq_read(consumed, &ptr, &seq);
940 if (avail == 0) {
941 ISCSI_DBG_TCP(conn, "no more data avail. Consumed %d\n",
942 consumed);
943 *status = ISCSI_TCP_SKB_DONE;
944 goto skb_done;
945 }
946 BUG_ON(segment->copied >= segment->size);
947
948 ISCSI_DBG_TCP(conn, "skb %p ptr=%p avail=%u\n", skb, ptr,
949 avail);
950 rc = iscsi_tcp_segment_recv(tcp_conn, segment, ptr, avail);
951 BUG_ON(rc == 0);
952 consumed += rc;
953
954 if (segment->total_copied >= segment->total_size) {
955 skb_abort_seq_read(&seq);
956 goto segment_done;
957 }
958 }
959
960 segment_done:
961 *status = ISCSI_TCP_SEGMENT_DONE;
962 ISCSI_DBG_TCP(conn, "segment done\n");
963 rc = segment->done(tcp_conn, segment);
964 if (rc != 0) {
965 *status = ISCSI_TCP_CONN_ERR;
966 ISCSI_DBG_TCP(conn, "Error receiving PDU, errno=%d\n", rc);
967 iscsi_conn_failure(conn, rc);
968 return 0;
969 }
970 /* The done() functions sets up the next segment. */
971
972 skb_done:
973 conn->rxdata_octets += consumed;
974 return consumed;
975 }
976 EXPORT_SYMBOL_GPL(iscsi_tcp_recv_skb);
977
978 /**
979 * iscsi_tcp_task_init - Initialize iSCSI SCSI_READ or SCSI_WRITE commands
980 * @task: scsi command task
981 */
iscsi_tcp_task_init(struct iscsi_task * task)982 int iscsi_tcp_task_init(struct iscsi_task *task)
983 {
984 struct iscsi_tcp_task *tcp_task = task->dd_data;
985 struct iscsi_conn *conn = task->conn;
986 struct scsi_cmnd *sc = task->sc;
987 int err;
988
989 if (!sc) {
990 /*
991 * mgmt tasks do not have a scatterlist since they come
992 * in from the iscsi interface.
993 */
994 ISCSI_DBG_TCP(conn, "mtask deq [itt 0x%x]\n", task->itt);
995
996 return conn->session->tt->init_pdu(task, 0, task->data_count);
997 }
998
999 BUG_ON(kfifo_len(&tcp_task->r2tqueue));
1000 tcp_task->exp_datasn = 0;
1001
1002 /* Prepare PDU, optionally w/ immediate data */
1003 ISCSI_DBG_TCP(conn, "task deq [itt 0x%x imm %d unsol %d]\n",
1004 task->itt, task->imm_count, task->unsol_r2t.data_length);
1005
1006 err = conn->session->tt->init_pdu(task, 0, task->imm_count);
1007 if (err)
1008 return err;
1009 task->imm_count = 0;
1010 return 0;
1011 }
1012 EXPORT_SYMBOL_GPL(iscsi_tcp_task_init);
1013
iscsi_tcp_get_curr_r2t(struct iscsi_task * task)1014 static struct iscsi_r2t_info *iscsi_tcp_get_curr_r2t(struct iscsi_task *task)
1015 {
1016 struct iscsi_tcp_task *tcp_task = task->dd_data;
1017 struct iscsi_r2t_info *r2t = NULL;
1018
1019 if (iscsi_task_has_unsol_data(task))
1020 r2t = &task->unsol_r2t;
1021 else {
1022 spin_lock_bh(&tcp_task->queue2pool);
1023 if (tcp_task->r2t) {
1024 r2t = tcp_task->r2t;
1025 /* Continue with this R2T? */
1026 if (r2t->data_length <= r2t->sent) {
1027 ISCSI_DBG_TCP(task->conn,
1028 " done with r2t %p\n", r2t);
1029 kfifo_in(&tcp_task->r2tpool.queue,
1030 (void *)&tcp_task->r2t,
1031 sizeof(void *));
1032 tcp_task->r2t = r2t = NULL;
1033 }
1034 }
1035
1036 if (r2t == NULL) {
1037 if (kfifo_out(&tcp_task->r2tqueue,
1038 (void *)&tcp_task->r2t, sizeof(void *)) !=
1039 sizeof(void *))
1040 r2t = NULL;
1041 else
1042 r2t = tcp_task->r2t;
1043 }
1044 spin_unlock_bh(&tcp_task->queue2pool);
1045 }
1046
1047 return r2t;
1048 }
1049
1050 /**
1051 * iscsi_tcp_task_xmit - xmit normal PDU task
1052 * @task: iscsi command task
1053 *
1054 * We're expected to return 0 when everything was transmitted successfully,
1055 * -EAGAIN if there's still data in the queue, or != 0 for any other kind
1056 * of error.
1057 */
iscsi_tcp_task_xmit(struct iscsi_task * task)1058 int iscsi_tcp_task_xmit(struct iscsi_task *task)
1059 {
1060 struct iscsi_conn *conn = task->conn;
1061 struct iscsi_session *session = conn->session;
1062 struct iscsi_r2t_info *r2t;
1063 int rc = 0;
1064
1065 flush:
1066 /* Flush any pending data first. */
1067 rc = session->tt->xmit_pdu(task);
1068 if (rc < 0)
1069 return rc;
1070
1071 /* mgmt command */
1072 if (!task->sc) {
1073 if (task->hdr->itt == RESERVED_ITT)
1074 iscsi_put_task(task);
1075 return 0;
1076 }
1077
1078 /* Are we done already? */
1079 if (task->sc->sc_data_direction != DMA_TO_DEVICE)
1080 return 0;
1081
1082 r2t = iscsi_tcp_get_curr_r2t(task);
1083 if (r2t == NULL) {
1084 /* Waiting for more R2Ts to arrive. */
1085 ISCSI_DBG_TCP(conn, "no R2Ts yet\n");
1086 return 0;
1087 }
1088
1089 rc = conn->session->tt->alloc_pdu(task, ISCSI_OP_SCSI_DATA_OUT);
1090 if (rc)
1091 return rc;
1092 iscsi_prep_data_out_pdu(task, r2t, (struct iscsi_data *) task->hdr);
1093
1094 ISCSI_DBG_TCP(conn, "sol dout %p [dsn %d itt 0x%x doff %d dlen %d]\n",
1095 r2t, r2t->datasn - 1, task->hdr->itt,
1096 r2t->data_offset + r2t->sent, r2t->data_count);
1097
1098 rc = conn->session->tt->init_pdu(task, r2t->data_offset + r2t->sent,
1099 r2t->data_count);
1100 if (rc) {
1101 iscsi_conn_failure(conn, ISCSI_ERR_XMIT_FAILED);
1102 return rc;
1103 }
1104
1105 r2t->sent += r2t->data_count;
1106 goto flush;
1107 }
1108 EXPORT_SYMBOL_GPL(iscsi_tcp_task_xmit);
1109
1110 struct iscsi_cls_conn *
iscsi_tcp_conn_setup(struct iscsi_cls_session * cls_session,int dd_data_size,uint32_t conn_idx)1111 iscsi_tcp_conn_setup(struct iscsi_cls_session *cls_session, int dd_data_size,
1112 uint32_t conn_idx)
1113
1114 {
1115 struct iscsi_conn *conn;
1116 struct iscsi_cls_conn *cls_conn;
1117 struct iscsi_tcp_conn *tcp_conn;
1118
1119 cls_conn = iscsi_conn_setup(cls_session,
1120 sizeof(*tcp_conn) + dd_data_size, conn_idx);
1121 if (!cls_conn)
1122 return NULL;
1123 conn = cls_conn->dd_data;
1124 /*
1125 * due to strange issues with iser these are not set
1126 * in iscsi_conn_setup
1127 */
1128 conn->max_recv_dlength = ISCSI_DEF_MAX_RECV_SEG_LEN;
1129
1130 tcp_conn = conn->dd_data;
1131 tcp_conn->iscsi_conn = conn;
1132 tcp_conn->dd_data = conn->dd_data + sizeof(*tcp_conn);
1133 return cls_conn;
1134 }
1135 EXPORT_SYMBOL_GPL(iscsi_tcp_conn_setup);
1136
iscsi_tcp_conn_teardown(struct iscsi_cls_conn * cls_conn)1137 void iscsi_tcp_conn_teardown(struct iscsi_cls_conn *cls_conn)
1138 {
1139 iscsi_conn_teardown(cls_conn);
1140 }
1141 EXPORT_SYMBOL_GPL(iscsi_tcp_conn_teardown);
1142
iscsi_tcp_r2tpool_alloc(struct iscsi_session * session)1143 int iscsi_tcp_r2tpool_alloc(struct iscsi_session *session)
1144 {
1145 int i;
1146 int cmd_i;
1147
1148 /*
1149 * initialize per-task: R2T pool and xmit queue
1150 */
1151 for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
1152 struct iscsi_task *task = session->cmds[cmd_i];
1153 struct iscsi_tcp_task *tcp_task = task->dd_data;
1154
1155 /*
1156 * pre-allocated x2 as much r2ts to handle race when
1157 * target acks DataOut faster than we data_xmit() queues
1158 * could replenish r2tqueue.
1159 */
1160
1161 /* R2T pool */
1162 if (iscsi_pool_init(&tcp_task->r2tpool,
1163 session->max_r2t * 2, NULL,
1164 sizeof(struct iscsi_r2t_info))) {
1165 goto r2t_alloc_fail;
1166 }
1167
1168 /* R2T xmit queue */
1169 if (kfifo_alloc(&tcp_task->r2tqueue,
1170 session->max_r2t * 4 * sizeof(void*), GFP_KERNEL)) {
1171 iscsi_pool_free(&tcp_task->r2tpool);
1172 goto r2t_alloc_fail;
1173 }
1174 spin_lock_init(&tcp_task->pool2queue);
1175 spin_lock_init(&tcp_task->queue2pool);
1176 }
1177
1178 return 0;
1179
1180 r2t_alloc_fail:
1181 for (i = 0; i < cmd_i; i++) {
1182 struct iscsi_task *task = session->cmds[i];
1183 struct iscsi_tcp_task *tcp_task = task->dd_data;
1184
1185 kfifo_free(&tcp_task->r2tqueue);
1186 iscsi_pool_free(&tcp_task->r2tpool);
1187 }
1188 return -ENOMEM;
1189 }
1190 EXPORT_SYMBOL_GPL(iscsi_tcp_r2tpool_alloc);
1191
iscsi_tcp_r2tpool_free(struct iscsi_session * session)1192 void iscsi_tcp_r2tpool_free(struct iscsi_session *session)
1193 {
1194 int i;
1195
1196 for (i = 0; i < session->cmds_max; i++) {
1197 struct iscsi_task *task = session->cmds[i];
1198 struct iscsi_tcp_task *tcp_task = task->dd_data;
1199
1200 kfifo_free(&tcp_task->r2tqueue);
1201 iscsi_pool_free(&tcp_task->r2tpool);
1202 }
1203 }
1204 EXPORT_SYMBOL_GPL(iscsi_tcp_r2tpool_free);
1205
iscsi_tcp_set_max_r2t(struct iscsi_conn * conn,char * buf)1206 int iscsi_tcp_set_max_r2t(struct iscsi_conn *conn, char *buf)
1207 {
1208 struct iscsi_session *session = conn->session;
1209 unsigned short r2ts = 0;
1210
1211 sscanf(buf, "%hu", &r2ts);
1212 if (session->max_r2t == r2ts)
1213 return 0;
1214
1215 if (!r2ts || !is_power_of_2(r2ts))
1216 return -EINVAL;
1217
1218 session->max_r2t = r2ts;
1219 iscsi_tcp_r2tpool_free(session);
1220 return iscsi_tcp_r2tpool_alloc(session);
1221 }
1222 EXPORT_SYMBOL_GPL(iscsi_tcp_set_max_r2t);
1223
iscsi_tcp_conn_get_stats(struct iscsi_cls_conn * cls_conn,struct iscsi_stats * stats)1224 void iscsi_tcp_conn_get_stats(struct iscsi_cls_conn *cls_conn,
1225 struct iscsi_stats *stats)
1226 {
1227 struct iscsi_conn *conn = cls_conn->dd_data;
1228
1229 stats->txdata_octets = conn->txdata_octets;
1230 stats->rxdata_octets = conn->rxdata_octets;
1231 stats->scsicmd_pdus = conn->scsicmd_pdus_cnt;
1232 stats->dataout_pdus = conn->dataout_pdus_cnt;
1233 stats->scsirsp_pdus = conn->scsirsp_pdus_cnt;
1234 stats->datain_pdus = conn->datain_pdus_cnt;
1235 stats->r2t_pdus = conn->r2t_pdus_cnt;
1236 stats->tmfcmd_pdus = conn->tmfcmd_pdus_cnt;
1237 stats->tmfrsp_pdus = conn->tmfrsp_pdus_cnt;
1238 }
1239 EXPORT_SYMBOL_GPL(iscsi_tcp_conn_get_stats);
1240