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agk-dm-dm-crypt-tidy-crypt_endio
[linux-2.6/linux-trees-mm.git] / drivers / scsi / iscsi_tcp.c
blob4bcf916c21a7e0c50ef853bbe0cec582916f49c4
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/list.h>
31 #include <linux/inet.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("Dmitry Yusupov <dmitry_yus@yahoo.com>, "
48 "Alex Aizman <itn780@yahoo.com>");
49 MODULE_DESCRIPTION("iSCSI/TCP data-path");
50 MODULE_LICENSE("GPL");
51 /* #define DEBUG_TCP */
52 #define DEBUG_ASSERT
53
54 #ifdef DEBUG_TCP
55 #define debug_tcp(fmt...) printk(KERN_INFO "tcp: " fmt)
56 #else
57 #define debug_tcp(fmt...)
58 #endif
59
60 #ifndef DEBUG_ASSERT
61 #ifdef BUG_ON
62 #undef BUG_ON
63 #endif
64 #define BUG_ON(expr)
65 #endif
66
67 static unsigned int iscsi_max_lun = 512;
68 module_param_named(max_lun, iscsi_max_lun, uint, S_IRUGO);
69
70 static inline void
71 iscsi_buf_init_iov(struct iscsi_buf *ibuf, char *vbuf, int size)
72 {
73 sg_init_one(&ibuf->sg, vbuf, size);
74 ibuf->sent = 0;
75 ibuf->use_sendmsg = 1;
76 }
77
78 static inline void
79 iscsi_buf_init_sg(struct iscsi_buf *ibuf, struct scatterlist *sg)
80 {
81 sg_init_table(&ibuf->sg, 1);
82 sg_set_page(&ibuf->sg, sg_page(sg), sg->length, sg->offset);
83 /*
84 * Fastpath: sg element fits into single page
85 */
86 if (sg->length + sg->offset <= PAGE_SIZE && !PageSlab(sg_page(sg)))
87 ibuf->use_sendmsg = 0;
88 else
89 ibuf->use_sendmsg = 1;
90 ibuf->sent = 0;
91 }
92
93 static inline int
94 iscsi_buf_left(struct iscsi_buf *ibuf)
95 {
96 int rc;
97
98 rc = ibuf->sg.length - ibuf->sent;
99 BUG_ON(rc < 0);
100 return rc;
101 }
102
103 static inline void
104 iscsi_hdr_digest(struct iscsi_conn *conn, struct iscsi_buf *buf,
105 u8* crc)
106 {
107 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
108
109 crypto_hash_digest(&tcp_conn->tx_hash, &buf->sg, buf->sg.length, crc);
110 buf->sg.length += sizeof(u32);
111 }
112
113 static inline int
114 iscsi_hdr_extract(struct iscsi_tcp_conn *tcp_conn)
115 {
116 struct sk_buff *skb = tcp_conn->in.skb;
117
118 tcp_conn->in.zero_copy_hdr = 0;
119
120 if (tcp_conn->in.copy >= tcp_conn->hdr_size &&
121 tcp_conn->in_progress == IN_PROGRESS_WAIT_HEADER) {
122 /*
123 * Zero-copy PDU Header: using connection context
124 * to store header pointer.
125 */
126 if (skb_shinfo(skb)->frag_list == NULL &&
127 !skb_shinfo(skb)->nr_frags) {
128 tcp_conn->in.hdr = (struct iscsi_hdr *)
129 ((char*)skb->data + tcp_conn->in.offset);
130 tcp_conn->in.zero_copy_hdr = 1;
131 } else {
132 /* ignoring return code since we checked
133 * in.copy before */
134 skb_copy_bits(skb, tcp_conn->in.offset,
135 &tcp_conn->hdr, tcp_conn->hdr_size);
136 tcp_conn->in.hdr = &tcp_conn->hdr;
137 }
138 tcp_conn->in.offset += tcp_conn->hdr_size;
139 tcp_conn->in.copy -= tcp_conn->hdr_size;
140 } else {
141 int hdr_remains;
142 int copylen;
143
144 /*
145 * PDU header scattered across SKB's,
146 * copying it... This'll happen quite rarely.
147 */
148
149 if (tcp_conn->in_progress == IN_PROGRESS_WAIT_HEADER)
150 tcp_conn->in.hdr_offset = 0;
151
152 hdr_remains = tcp_conn->hdr_size - tcp_conn->in.hdr_offset;
153 BUG_ON(hdr_remains <= 0);
154
155 copylen = min(tcp_conn->in.copy, hdr_remains);
156 skb_copy_bits(skb, tcp_conn->in.offset,
157 (char*)&tcp_conn->hdr + tcp_conn->in.hdr_offset,
158 copylen);
159
160 debug_tcp("PDU gather offset %d bytes %d in.offset %d "
161 "in.copy %d\n", tcp_conn->in.hdr_offset, copylen,
162 tcp_conn->in.offset, tcp_conn->in.copy);
163
164 tcp_conn->in.offset += copylen;
165 tcp_conn->in.copy -= copylen;
166 if (copylen < hdr_remains) {
167 tcp_conn->in_progress = IN_PROGRESS_HEADER_GATHER;
168 tcp_conn->in.hdr_offset += copylen;
169 return -EAGAIN;
170 }
171 tcp_conn->in.hdr = &tcp_conn->hdr;
172 tcp_conn->discontiguous_hdr_cnt++;
173 tcp_conn->in_progress = IN_PROGRESS_WAIT_HEADER;
174 }
175
176 return 0;
177 }
178
179 /*
180 * must be called with session lock
181 */
182 static void
183 iscsi_tcp_cleanup_ctask(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
184 {
185 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
186 struct iscsi_r2t_info *r2t;
187 struct scsi_cmnd *sc;
188
189 /* flush ctask's r2t queues */
190 while (__kfifo_get(tcp_ctask->r2tqueue, (void*)&r2t, sizeof(void*))) {
191 __kfifo_put(tcp_ctask->r2tpool.queue, (void*)&r2t,
192 sizeof(void*));
193 debug_scsi("iscsi_tcp_cleanup_ctask pending r2t dropped\n");
194 }
195
196 sc = ctask->sc;
197 if (unlikely(!sc))
198 return;
199
200 tcp_ctask->xmstate = XMSTATE_IDLE;
201 tcp_ctask->r2t = NULL;
202 }
203
204 /**
205 * iscsi_data_rsp - SCSI Data-In Response processing
206 * @conn: iscsi connection
207 * @ctask: scsi command task
208 **/
209 static int
210 iscsi_data_rsp(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
211 {
212 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
213 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
214 struct iscsi_data_rsp *rhdr = (struct iscsi_data_rsp *)tcp_conn->in.hdr;
215 struct iscsi_session *session = conn->session;
216 struct scsi_cmnd *sc = ctask->sc;
217 int datasn = be32_to_cpu(rhdr->datasn);
218
219 iscsi_update_cmdsn(session, (struct iscsi_nopin*)rhdr);
220 /*
221 * setup Data-In byte counter (gets decremented..)
222 */
223 ctask->data_count = tcp_conn->in.datalen;
224
225 if (tcp_conn->in.datalen == 0)
226 return 0;
227
228 if (tcp_ctask->exp_datasn != datasn) {
229 debug_tcp("%s: ctask->exp_datasn(%d) != rhdr->datasn(%d)\n",
230 __FUNCTION__, tcp_ctask->exp_datasn, datasn);
231 return ISCSI_ERR_DATASN;
232 }
233
234 tcp_ctask->exp_datasn++;
235
236 tcp_ctask->data_offset = be32_to_cpu(rhdr->offset);
237 if (tcp_ctask->data_offset + tcp_conn->in.datalen > scsi_bufflen(sc)) {
238 debug_tcp("%s: data_offset(%d) + data_len(%d) > total_length_in(%d)\n",
239 __FUNCTION__, tcp_ctask->data_offset,
240 tcp_conn->in.datalen, scsi_bufflen(sc));
241 return ISCSI_ERR_DATA_OFFSET;
242 }
243
244 if (rhdr->flags & ISCSI_FLAG_DATA_STATUS) {
245 conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
246 if (rhdr->flags & ISCSI_FLAG_DATA_UNDERFLOW) {
247 int res_count = be32_to_cpu(rhdr->residual_count);
248
249 if (res_count > 0 &&
250 res_count <= scsi_bufflen(sc)) {
251 scsi_set_resid(sc, res_count);
252 sc->result = (DID_OK << 16) | rhdr->cmd_status;
253 } else
254 sc->result = (DID_BAD_TARGET << 16) |
255 rhdr->cmd_status;
256 } else if (rhdr->flags & ISCSI_FLAG_DATA_OVERFLOW) {
257 scsi_set_resid(sc, be32_to_cpu(rhdr->residual_count));
258 sc->result = (DID_OK << 16) | rhdr->cmd_status;
259 } else
260 sc->result = (DID_OK << 16) | rhdr->cmd_status;
261 }
262
263 conn->datain_pdus_cnt++;
264 return 0;
265 }
266
267 /**
268 * iscsi_solicit_data_init - initialize first Data-Out
269 * @conn: iscsi connection
270 * @ctask: scsi command task
271 * @r2t: R2T info
272 *
273 * Notes:
274 * Initialize first Data-Out within this R2T sequence and finds
275 * proper data_offset within this SCSI command.
276 *
277 * This function is called with connection lock taken.
278 **/
279 static void
280 iscsi_solicit_data_init(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
281 struct iscsi_r2t_info *r2t)
282 {
283 struct iscsi_data *hdr;
284 struct scsi_cmnd *sc = ctask->sc;
285 int i, sg_count = 0;
286 struct scatterlist *sg;
287
288 hdr = &r2t->dtask.hdr;
289 memset(hdr, 0, sizeof(struct iscsi_data));
290 hdr->ttt = r2t->ttt;
291 hdr->datasn = cpu_to_be32(r2t->solicit_datasn);
292 r2t->solicit_datasn++;
293 hdr->opcode = ISCSI_OP_SCSI_DATA_OUT;
294 memcpy(hdr->lun, ctask->hdr->lun, sizeof(hdr->lun));
295 hdr->itt = ctask->hdr->itt;
296 hdr->exp_statsn = r2t->exp_statsn;
297 hdr->offset = cpu_to_be32(r2t->data_offset);
298 if (r2t->data_length > conn->max_xmit_dlength) {
299 hton24(hdr->dlength, conn->max_xmit_dlength);
300 r2t->data_count = conn->max_xmit_dlength;
301 hdr->flags = 0;
302 } else {
303 hton24(hdr->dlength, r2t->data_length);
304 r2t->data_count = r2t->data_length;
305 hdr->flags = ISCSI_FLAG_CMD_FINAL;
306 }
307 conn->dataout_pdus_cnt++;
308
309 r2t->sent = 0;
310
311 iscsi_buf_init_iov(&r2t->headbuf, (char*)hdr,
312 sizeof(struct iscsi_hdr));
313
314 sg = scsi_sglist(sc);
315 r2t->sg = NULL;
316 for (i = 0; i < scsi_sg_count(sc); i++, sg += 1) {
317 /* FIXME: prefetch ? */
318 if (sg_count + sg->length > r2t->data_offset) {
319 int page_offset;
320
321 /* sg page found! */
322
323 /* offset within this page */
324 page_offset = r2t->data_offset - sg_count;
325
326 /* fill in this buffer */
327 iscsi_buf_init_sg(&r2t->sendbuf, sg);
328 r2t->sendbuf.sg.offset += page_offset;
329 r2t->sendbuf.sg.length -= page_offset;
330
331 /* xmit logic will continue with next one */
332 r2t->sg = sg + 1;
333 break;
334 }
335 sg_count += sg->length;
336 }
337 BUG_ON(r2t->sg == NULL);
338 }
339
340 /**
341 * iscsi_r2t_rsp - iSCSI R2T Response processing
342 * @conn: iscsi connection
343 * @ctask: scsi command task
344 **/
345 static int
346 iscsi_r2t_rsp(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
347 {
348 struct iscsi_r2t_info *r2t;
349 struct iscsi_session *session = conn->session;
350 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
351 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
352 struct iscsi_r2t_rsp *rhdr = (struct iscsi_r2t_rsp *)tcp_conn->in.hdr;
353 int r2tsn = be32_to_cpu(rhdr->r2tsn);
354 int rc;
355
356 if (tcp_conn->in.datalen) {
357 printk(KERN_ERR "iscsi_tcp: invalid R2t with datalen %d\n",
358 tcp_conn->in.datalen);
359 return ISCSI_ERR_DATALEN;
360 }
361
362 if (tcp_ctask->exp_datasn != r2tsn){
363 debug_tcp("%s: ctask->exp_datasn(%d) != rhdr->r2tsn(%d)\n",
364 __FUNCTION__, tcp_ctask->exp_datasn, r2tsn);
365 return ISCSI_ERR_R2TSN;
366 }
367
368 /* fill-in new R2T associated with the task */
369 spin_lock(&session->lock);
370 iscsi_update_cmdsn(session, (struct iscsi_nopin*)rhdr);
371
372 if (!ctask->sc || ctask->mtask ||
373 session->state != ISCSI_STATE_LOGGED_IN) {
374 printk(KERN_INFO "iscsi_tcp: dropping R2T itt %d in "
375 "recovery...\n", ctask->itt);
376 spin_unlock(&session->lock);
377 return 0;
378 }
379
380 rc = __kfifo_get(tcp_ctask->r2tpool.queue, (void*)&r2t, sizeof(void*));
381 BUG_ON(!rc);
382
383 r2t->exp_statsn = rhdr->statsn;
384 r2t->data_length = be32_to_cpu(rhdr->data_length);
385 if (r2t->data_length == 0) {
386 printk(KERN_ERR "iscsi_tcp: invalid R2T with zero data len\n");
387 spin_unlock(&session->lock);
388 return ISCSI_ERR_DATALEN;
389 }
390
391 if (r2t->data_length > session->max_burst)
392 debug_scsi("invalid R2T with data len %u and max burst %u."
393 "Attempting to execute request.\n",
394 r2t->data_length, session->max_burst);
395
396 r2t->data_offset = be32_to_cpu(rhdr->data_offset);
397 if (r2t->data_offset + r2t->data_length > scsi_bufflen(ctask->sc)) {
398 spin_unlock(&session->lock);
399 printk(KERN_ERR "iscsi_tcp: invalid R2T with data len %u at "
400 "offset %u and total length %d\n", r2t->data_length,
401 r2t->data_offset, scsi_bufflen(ctask->sc));
402 return ISCSI_ERR_DATALEN;
403 }
404
405 r2t->ttt = rhdr->ttt; /* no flip */
406 r2t->solicit_datasn = 0;
407
408 iscsi_solicit_data_init(conn, ctask, r2t);
409
410 tcp_ctask->exp_datasn = r2tsn + 1;
411 __kfifo_put(tcp_ctask->r2tqueue, (void*)&r2t, sizeof(void*));
412 tcp_ctask->xmstate |= XMSTATE_SOL_HDR_INIT;
413 list_move_tail(&ctask->running, &conn->xmitqueue);
414
415 scsi_queue_work(session->host, &conn->xmitwork);
416 conn->r2t_pdus_cnt++;
417 spin_unlock(&session->lock);
418
419 return 0;
420 }
421
422 static int
423 iscsi_tcp_hdr_recv(struct iscsi_conn *conn)
424 {
425 int rc = 0, opcode, ahslen;
426 struct iscsi_hdr *hdr;
427 struct iscsi_session *session = conn->session;
428 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
429 uint32_t cdgst, rdgst = 0, itt;
430
431 hdr = tcp_conn->in.hdr;
432
433 /* verify PDU length */
434 tcp_conn->in.datalen = ntoh24(hdr->dlength);
435 if (tcp_conn->in.datalen > conn->max_recv_dlength) {
436 printk(KERN_ERR "iscsi_tcp: datalen %d > %d\n",
437 tcp_conn->in.datalen, conn->max_recv_dlength);
438 return ISCSI_ERR_DATALEN;
439 }
440 tcp_conn->data_copied = 0;
441
442 /* read AHS */
443 ahslen = hdr->hlength << 2;
444 tcp_conn->in.offset += ahslen;
445 tcp_conn->in.copy -= ahslen;
446 if (tcp_conn->in.copy < 0) {
447 printk(KERN_ERR "iscsi_tcp: can't handle AHS with length "
448 "%d bytes\n", ahslen);
449 return ISCSI_ERR_AHSLEN;
450 }
451
452 /* calculate read padding */
453 tcp_conn->in.padding = tcp_conn->in.datalen & (ISCSI_PAD_LEN-1);
454 if (tcp_conn->in.padding) {
455 tcp_conn->in.padding = ISCSI_PAD_LEN - tcp_conn->in.padding;
456 debug_scsi("read padding %d bytes\n", tcp_conn->in.padding);
457 }
458
459 if (conn->hdrdgst_en) {
460 struct scatterlist sg;
461
462 sg_init_one(&sg, (u8 *)hdr,
463 sizeof(struct iscsi_hdr) + ahslen);
464 crypto_hash_digest(&tcp_conn->rx_hash, &sg, sg.length,
465 (u8 *)&cdgst);
466 rdgst = *(uint32_t*)((char*)hdr + sizeof(struct iscsi_hdr) +
467 ahslen);
468 if (cdgst != rdgst) {
469 printk(KERN_ERR "iscsi_tcp: hdrdgst error "
470 "recv 0x%x calc 0x%x\n", rdgst, cdgst);
471 return ISCSI_ERR_HDR_DGST;
472 }
473 }
474
475 opcode = hdr->opcode & ISCSI_OPCODE_MASK;
476 /* verify itt (itt encoding: age+cid+itt) */
477 rc = iscsi_verify_itt(conn, hdr, &itt);
478 if (rc == ISCSI_ERR_NO_SCSI_CMD) {
479 tcp_conn->in.datalen = 0; /* force drop */
480 return 0;
481 } else if (rc)
482 return rc;
483
484 debug_tcp("opcode 0x%x offset %d copy %d ahslen %d datalen %d\n",
485 opcode, tcp_conn->in.offset, tcp_conn->in.copy,
486 ahslen, tcp_conn->in.datalen);
487
488 switch(opcode) {
489 case ISCSI_OP_SCSI_DATA_IN:
490 tcp_conn->in.ctask = session->cmds[itt];
491 rc = iscsi_data_rsp(conn, tcp_conn->in.ctask);
492 if (rc)
493 return rc;
494 /* fall through */
495 case ISCSI_OP_SCSI_CMD_RSP:
496 tcp_conn->in.ctask = session->cmds[itt];
497 if (tcp_conn->in.datalen)
498 goto copy_hdr;
499
500 spin_lock(&session->lock);
501 rc = __iscsi_complete_pdu(conn, hdr, NULL, 0);
502 spin_unlock(&session->lock);
503 break;
504 case ISCSI_OP_R2T:
505 tcp_conn->in.ctask = session->cmds[itt];
506 if (ahslen)
507 rc = ISCSI_ERR_AHSLEN;
508 else if (tcp_conn->in.ctask->sc->sc_data_direction ==
509 DMA_TO_DEVICE)
510 rc = iscsi_r2t_rsp(conn, tcp_conn->in.ctask);
511 else
512 rc = ISCSI_ERR_PROTO;
513 break;
514 case ISCSI_OP_LOGIN_RSP:
515 case ISCSI_OP_TEXT_RSP:
516 case ISCSI_OP_REJECT:
517 case ISCSI_OP_ASYNC_EVENT:
518 /*
519 * It is possible that we could get a PDU with a buffer larger
520 * than 8K, but there are no targets that currently do this.
521 * For now we fail until we find a vendor that needs it
522 */
523 if (ISCSI_DEF_MAX_RECV_SEG_LEN <
524 tcp_conn->in.datalen) {
525 printk(KERN_ERR "iscsi_tcp: received buffer of len %u "
526 "but conn buffer is only %u (opcode %0x)\n",
527 tcp_conn->in.datalen,
528 ISCSI_DEF_MAX_RECV_SEG_LEN, opcode);
529 rc = ISCSI_ERR_PROTO;
530 break;
531 }
532
533 if (tcp_conn->in.datalen)
534 goto copy_hdr;
535 /* fall through */
536 case ISCSI_OP_LOGOUT_RSP:
537 case ISCSI_OP_NOOP_IN:
538 case ISCSI_OP_SCSI_TMFUNC_RSP:
539 rc = iscsi_complete_pdu(conn, hdr, NULL, 0);
540 break;
541 default:
542 rc = ISCSI_ERR_BAD_OPCODE;
543 break;
544 }
545
546 return rc;
547
548 copy_hdr:
549 /*
550 * if we did zero copy for the header but we will need multiple
551 * skbs to complete the command then we have to copy the header
552 * for later use
553 */
554 if (tcp_conn->in.zero_copy_hdr && tcp_conn->in.copy <=
555 (tcp_conn->in.datalen + tcp_conn->in.padding +
556 (conn->datadgst_en ? 4 : 0))) {
557 debug_tcp("Copying header for later use. in.copy %d in.datalen"
558 " %d\n", tcp_conn->in.copy, tcp_conn->in.datalen);
559 memcpy(&tcp_conn->hdr, tcp_conn->in.hdr,
560 sizeof(struct iscsi_hdr));
561 tcp_conn->in.hdr = &tcp_conn->hdr;
562 tcp_conn->in.zero_copy_hdr = 0;
563 }
564 return 0;
565 }
566
567 /**
568 * iscsi_ctask_copy - copy skb bits to the destanation cmd task
569 * @conn: iscsi tcp connection
570 * @ctask: scsi command task
571 * @buf: buffer to copy to
572 * @buf_size: size of buffer
573 * @offset: offset within the buffer
574 *
575 * Notes:
576 * The function calls skb_copy_bits() and updates per-connection and
577 * per-cmd byte counters.
578 *
579 * Read counters (in bytes):
580 *
581 * conn->in.offset offset within in progress SKB
582 * conn->in.copy left to copy from in progress SKB
583 * including padding
584 * conn->in.copied copied already from in progress SKB
585 * conn->data_copied copied already from in progress buffer
586 * ctask->sent total bytes sent up to the MidLayer
587 * ctask->data_count left to copy from in progress Data-In
588 * buf_left left to copy from in progress buffer
589 **/
590 static inline int
591 iscsi_ctask_copy(struct iscsi_tcp_conn *tcp_conn, struct iscsi_cmd_task *ctask,
592 void *buf, int buf_size, int offset)
593 {
594 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
595 int buf_left = buf_size - (tcp_conn->data_copied + offset);
596 unsigned size = min(tcp_conn->in.copy, buf_left);
597 int rc;
598
599 size = min(size, ctask->data_count);
600
601 debug_tcp("ctask_copy %d bytes at offset %d copied %d\n",
602 size, tcp_conn->in.offset, tcp_conn->in.copied);
603
604 BUG_ON(size <= 0);
605 BUG_ON(tcp_ctask->sent + size > scsi_bufflen(ctask->sc));
606
607 rc = skb_copy_bits(tcp_conn->in.skb, tcp_conn->in.offset,
608 (char*)buf + (offset + tcp_conn->data_copied), size);
609 /* must fit into skb->len */
610 BUG_ON(rc);
611
612 tcp_conn->in.offset += size;
613 tcp_conn->in.copy -= size;
614 tcp_conn->in.copied += size;
615 tcp_conn->data_copied += size;
616 tcp_ctask->sent += size;
617 ctask->data_count -= size;
618
619 BUG_ON(tcp_conn->in.copy < 0);
620 BUG_ON(ctask->data_count < 0);
621
622 if (buf_size != (tcp_conn->data_copied + offset)) {
623 if (!ctask->data_count) {
624 BUG_ON(buf_size - tcp_conn->data_copied < 0);
625 /* done with this PDU */
626 return buf_size - tcp_conn->data_copied;
627 }
628 return -EAGAIN;
629 }
630
631 /* done with this buffer or with both - PDU and buffer */
632 tcp_conn->data_copied = 0;
633 return 0;
634 }
635
636 /**
637 * iscsi_tcp_copy - copy skb bits to the destanation buffer
638 * @conn: iscsi tcp connection
639 *
640 * Notes:
641 * The function calls skb_copy_bits() and updates per-connection
642 * byte counters.
643 **/
644 static inline int
645 iscsi_tcp_copy(struct iscsi_conn *conn, int buf_size)
646 {
647 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
648 int buf_left = buf_size - tcp_conn->data_copied;
649 int size = min(tcp_conn->in.copy, buf_left);
650 int rc;
651
652 debug_tcp("tcp_copy %d bytes at offset %d copied %d\n",
653 size, tcp_conn->in.offset, tcp_conn->data_copied);
654 BUG_ON(size <= 0);
655
656 rc = skb_copy_bits(tcp_conn->in.skb, tcp_conn->in.offset,
657 (char*)conn->data + tcp_conn->data_copied, size);
658 BUG_ON(rc);
659
660 tcp_conn->in.offset += size;
661 tcp_conn->in.copy -= size;
662 tcp_conn->in.copied += size;
663 tcp_conn->data_copied += size;
664
665 if (buf_size != tcp_conn->data_copied)
666 return -EAGAIN;
667
668 return 0;
669 }
670
671 static inline void
672 partial_sg_digest_update(struct hash_desc *desc, struct scatterlist *sg,
673 int offset, int length)
674 {
675 struct scatterlist temp;
676
677 sg_init_table(&temp, 1);
678 sg_set_page(&temp, sg_page(sg), length, offset);
679 crypto_hash_update(desc, &temp, length);
680 }
681
682 static void
683 iscsi_recv_digest_update(struct iscsi_tcp_conn *tcp_conn, char* buf, int len)
684 {
685 struct scatterlist tmp;
686
687 sg_init_one(&tmp, buf, len);
688 crypto_hash_update(&tcp_conn->rx_hash, &tmp, len);
689 }
690
691 static int iscsi_scsi_data_in(struct iscsi_conn *conn)
692 {
693 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
694 struct iscsi_cmd_task *ctask = tcp_conn->in.ctask;
695 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
696 struct scsi_cmnd *sc = ctask->sc;
697 struct scatterlist *sg;
698 int i, offset, rc = 0;
699
700 BUG_ON((void*)ctask != sc->SCp.ptr);
701
702 offset = tcp_ctask->data_offset;
703 sg = scsi_sglist(sc);
704
705 if (tcp_ctask->data_offset)
706 for (i = 0; i < tcp_ctask->sg_count; i++)
707 offset -= sg[i].length;
708 /* we've passed through partial sg*/
709 if (offset < 0)
710 offset = 0;
711
712 for (i = tcp_ctask->sg_count; i < scsi_sg_count(sc); i++) {
713 char *dest;
714
715 dest = kmap_atomic(sg_page(&sg[i]), KM_SOFTIRQ0);
716 rc = iscsi_ctask_copy(tcp_conn, ctask, dest + sg[i].offset,
717 sg[i].length, offset);
718 kunmap_atomic(dest, KM_SOFTIRQ0);
719 if (rc == -EAGAIN)
720 /* continue with the next SKB/PDU */
721 return rc;
722 if (!rc) {
723 if (conn->datadgst_en) {
724 if (!offset)
725 crypto_hash_update(
726 &tcp_conn->rx_hash,
727 &sg[i], sg[i].length);
728 else
729 partial_sg_digest_update(
730 &tcp_conn->rx_hash,
731 &sg[i],
732 sg[i].offset + offset,
733 sg[i].length - offset);
734 }
735 offset = 0;
736 tcp_ctask->sg_count++;
737 }
738
739 if (!ctask->data_count) {
740 if (rc && conn->datadgst_en)
741 /*
742 * data-in is complete, but buffer not...
743 */
744 partial_sg_digest_update(&tcp_conn->rx_hash,
745 &sg[i],
746 sg[i].offset,
747 sg[i].length-rc);
748 rc = 0;
749 break;
750 }
751
752 if (!tcp_conn->in.copy)
753 return -EAGAIN;
754 }
755 BUG_ON(ctask->data_count);
756
757 /* check for non-exceptional status */
758 if (tcp_conn->in.hdr->flags & ISCSI_FLAG_DATA_STATUS) {
759 debug_scsi("done [sc %lx res %d itt 0x%x flags 0x%x]\n",
760 (long)sc, sc->result, ctask->itt,
761 tcp_conn->in.hdr->flags);
762 spin_lock(&conn->session->lock);
763 __iscsi_complete_pdu(conn, tcp_conn->in.hdr, NULL, 0);
764 spin_unlock(&conn->session->lock);
765 }
766
767 return rc;
768 }
769
770 static int
771 iscsi_data_recv(struct iscsi_conn *conn)
772 {
773 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
774 int rc = 0, opcode;
775
776 opcode = tcp_conn->in.hdr->opcode & ISCSI_OPCODE_MASK;
777 switch (opcode) {
778 case ISCSI_OP_SCSI_DATA_IN:
779 rc = iscsi_scsi_data_in(conn);
780 break;
781 case ISCSI_OP_SCSI_CMD_RSP:
782 case ISCSI_OP_TEXT_RSP:
783 case ISCSI_OP_LOGIN_RSP:
784 case ISCSI_OP_ASYNC_EVENT:
785 case ISCSI_OP_REJECT:
786 /*
787 * Collect data segment to the connection's data
788 * placeholder
789 */
790 if (iscsi_tcp_copy(conn, tcp_conn->in.datalen)) {
791 rc = -EAGAIN;
792 goto exit;
793 }
794
795 rc = iscsi_complete_pdu(conn, tcp_conn->in.hdr, conn->data,
796 tcp_conn->in.datalen);
797 if (!rc && conn->datadgst_en && opcode != ISCSI_OP_LOGIN_RSP)
798 iscsi_recv_digest_update(tcp_conn, conn->data,
799 tcp_conn->in.datalen);
800 break;
801 default:
802 BUG_ON(1);
803 }
804 exit:
805 return rc;
806 }
807
808 /**
809 * iscsi_tcp_data_recv - TCP receive in sendfile fashion
810 * @rd_desc: read descriptor
811 * @skb: socket buffer
812 * @offset: offset in skb
813 * @len: skb->len - offset
814 **/
815 static int
816 iscsi_tcp_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb,
817 unsigned int offset, size_t len)
818 {
819 int rc;
820 struct iscsi_conn *conn = rd_desc->arg.data;
821 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
822 int processed;
823 char pad[ISCSI_PAD_LEN];
824 struct scatterlist sg;
825
826 /*
827 * Save current SKB and its offset in the corresponding
828 * connection context.
829 */
830 tcp_conn->in.copy = skb->len - offset;
831 tcp_conn->in.offset = offset;
832 tcp_conn->in.skb = skb;
833 tcp_conn->in.len = tcp_conn->in.copy;
834 BUG_ON(tcp_conn->in.copy <= 0);
835 debug_tcp("in %d bytes\n", tcp_conn->in.copy);
836
837 more:
838 tcp_conn->in.copied = 0;
839 rc = 0;
840
841 if (unlikely(conn->suspend_rx)) {
842 debug_tcp("conn %d Rx suspended!\n", conn->id);
843 return 0;
844 }
845
846 if (tcp_conn->in_progress == IN_PROGRESS_WAIT_HEADER ||
847 tcp_conn->in_progress == IN_PROGRESS_HEADER_GATHER) {
848 rc = iscsi_hdr_extract(tcp_conn);
849 if (rc) {
850 if (rc == -EAGAIN)
851 goto nomore;
852 else {
853 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
854 return 0;
855 }
856 }
857
858 /*
859 * Verify and process incoming PDU header.
860 */
861 rc = iscsi_tcp_hdr_recv(conn);
862 if (!rc && tcp_conn->in.datalen) {
863 if (conn->datadgst_en)
864 crypto_hash_init(&tcp_conn->rx_hash);
865 tcp_conn->in_progress = IN_PROGRESS_DATA_RECV;
866 } else if (rc) {
867 iscsi_conn_failure(conn, rc);
868 return 0;
869 }
870 }
871
872 if (tcp_conn->in_progress == IN_PROGRESS_DDIGEST_RECV &&
873 tcp_conn->in.copy) {
874 uint32_t recv_digest;
875
876 debug_tcp("extra data_recv offset %d copy %d\n",
877 tcp_conn->in.offset, tcp_conn->in.copy);
878
879 if (!tcp_conn->data_copied) {
880 if (tcp_conn->in.padding) {
881 debug_tcp("padding -> %d\n",
882 tcp_conn->in.padding);
883 memset(pad, 0, tcp_conn->in.padding);
884 sg_init_one(&sg, pad, tcp_conn->in.padding);
885 crypto_hash_update(&tcp_conn->rx_hash,
886 &sg, sg.length);
887 }
888 crypto_hash_final(&tcp_conn->rx_hash,
889 (u8 *) &tcp_conn->in.datadgst);
890 debug_tcp("rx digest 0x%x\n", tcp_conn->in.datadgst);
891 }
892
893 rc = iscsi_tcp_copy(conn, sizeof(uint32_t));
894 if (rc) {
895 if (rc == -EAGAIN)
896 goto again;
897 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
898 return 0;
899 }
900
901 memcpy(&recv_digest, conn->data, sizeof(uint32_t));
902 if (recv_digest != tcp_conn->in.datadgst) {
903 debug_tcp("iscsi_tcp: data digest error!"
904 "0x%x != 0x%x\n", recv_digest,
905 tcp_conn->in.datadgst);
906 iscsi_conn_failure(conn, ISCSI_ERR_DATA_DGST);
907 return 0;
908 } else {
909 debug_tcp("iscsi_tcp: data digest match!"
910 "0x%x == 0x%x\n", recv_digest,
911 tcp_conn->in.datadgst);
912 tcp_conn->in_progress = IN_PROGRESS_WAIT_HEADER;
913 }
914 }
915
916 if (tcp_conn->in_progress == IN_PROGRESS_DATA_RECV &&
917 tcp_conn->in.copy) {
918 debug_tcp("data_recv offset %d copy %d\n",
919 tcp_conn->in.offset, tcp_conn->in.copy);
920
921 rc = iscsi_data_recv(conn);
922 if (rc) {
923 if (rc == -EAGAIN)
924 goto again;
925 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
926 return 0;
927 }
928
929 if (tcp_conn->in.padding)
930 tcp_conn->in_progress = IN_PROGRESS_PAD_RECV;
931 else if (conn->datadgst_en)
932 tcp_conn->in_progress = IN_PROGRESS_DDIGEST_RECV;
933 else
934 tcp_conn->in_progress = IN_PROGRESS_WAIT_HEADER;
935 tcp_conn->data_copied = 0;
936 }
937
938 if (tcp_conn->in_progress == IN_PROGRESS_PAD_RECV &&
939 tcp_conn->in.copy) {
940 int copylen = min(tcp_conn->in.padding - tcp_conn->data_copied,
941 tcp_conn->in.copy);
942
943 tcp_conn->in.copy -= copylen;
944 tcp_conn->in.offset += copylen;
945 tcp_conn->data_copied += copylen;
946
947 if (tcp_conn->data_copied != tcp_conn->in.padding)
948 tcp_conn->in_progress = IN_PROGRESS_PAD_RECV;
949 else if (conn->datadgst_en)
950 tcp_conn->in_progress = IN_PROGRESS_DDIGEST_RECV;
951 else
952 tcp_conn->in_progress = IN_PROGRESS_WAIT_HEADER;
953 tcp_conn->data_copied = 0;
954 }
955
956 debug_tcp("f, processed %d from out of %d padding %d\n",
957 tcp_conn->in.offset - offset, (int)len, tcp_conn->in.padding);
958 BUG_ON(tcp_conn->in.offset - offset > len);
959
960 if (tcp_conn->in.offset - offset != len) {
961 debug_tcp("continue to process %d bytes\n",
962 (int)len - (tcp_conn->in.offset - offset));
963 goto more;
964 }
965
966 nomore:
967 processed = tcp_conn->in.offset - offset;
968 BUG_ON(processed == 0);
969 return processed;
970
971 again:
972 processed = tcp_conn->in.offset - offset;
973 debug_tcp("c, processed %d from out of %d rd_desc_cnt %d\n",
974 processed, (int)len, (int)rd_desc->count);
975 BUG_ON(processed == 0);
976 BUG_ON(processed > len);
977
978 conn->rxdata_octets += processed;
979 return processed;
980 }
981
982 static void
983 iscsi_tcp_data_ready(struct sock *sk, int flag)
984 {
985 struct iscsi_conn *conn = sk->sk_user_data;
986 read_descriptor_t rd_desc;
987
988 read_lock(&sk->sk_callback_lock);
989
990 /*
991 * Use rd_desc to pass 'conn' to iscsi_tcp_data_recv.
992 * We set count to 1 because we want the network layer to
993 * hand us all the skbs that are available. iscsi_tcp_data_recv
994 * handled pdus that cross buffers or pdus that still need data.
995 */
996 rd_desc.arg.data = conn;
997 rd_desc.count = 1;
998 tcp_read_sock(sk, &rd_desc, iscsi_tcp_data_recv);
999
1000 read_unlock(&sk->sk_callback_lock);
1001 }
1002
1003 static void
1004 iscsi_tcp_state_change(struct sock *sk)
1005 {
1006 struct iscsi_tcp_conn *tcp_conn;
1007 struct iscsi_conn *conn;
1008 struct iscsi_session *session;
1009 void (*old_state_change)(struct sock *);
1010
1011 read_lock(&sk->sk_callback_lock);
1012
1013 conn = (struct iscsi_conn*)sk->sk_user_data;
1014 session = conn->session;
1015
1016 if ((sk->sk_state == TCP_CLOSE_WAIT ||
1017 sk->sk_state == TCP_CLOSE) &&
1018 !atomic_read(&sk->sk_rmem_alloc)) {
1019 debug_tcp("iscsi_tcp_state_change: TCP_CLOSE|TCP_CLOSE_WAIT\n");
1020 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1021 }
1022
1023 tcp_conn = conn->dd_data;
1024 old_state_change = tcp_conn->old_state_change;
1025
1026 read_unlock(&sk->sk_callback_lock);
1027
1028 old_state_change(sk);
1029 }
1030
1031 /**
1032 * iscsi_write_space - Called when more output buffer space is available
1033 * @sk: socket space is available for
1034 **/
1035 static void
1036 iscsi_write_space(struct sock *sk)
1037 {
1038 struct iscsi_conn *conn = (struct iscsi_conn*)sk->sk_user_data;
1039 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1040
1041 tcp_conn->old_write_space(sk);
1042 debug_tcp("iscsi_write_space: cid %d\n", conn->id);
1043 scsi_queue_work(conn->session->host, &conn->xmitwork);
1044 }
1045
1046 static void
1047 iscsi_conn_set_callbacks(struct iscsi_conn *conn)
1048 {
1049 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1050 struct sock *sk = tcp_conn->sock->sk;
1051
1052 /* assign new callbacks */
1053 write_lock_bh(&sk->sk_callback_lock);
1054 sk->sk_user_data = conn;
1055 tcp_conn->old_data_ready = sk->sk_data_ready;
1056 tcp_conn->old_state_change = sk->sk_state_change;
1057 tcp_conn->old_write_space = sk->sk_write_space;
1058 sk->sk_data_ready = iscsi_tcp_data_ready;
1059 sk->sk_state_change = iscsi_tcp_state_change;
1060 sk->sk_write_space = iscsi_write_space;
1061 write_unlock_bh(&sk->sk_callback_lock);
1062 }
1063
1064 static void
1065 iscsi_conn_restore_callbacks(struct iscsi_tcp_conn *tcp_conn)
1066 {
1067 struct sock *sk = tcp_conn->sock->sk;
1068
1069 /* restore socket callbacks, see also: iscsi_conn_set_callbacks() */
1070 write_lock_bh(&sk->sk_callback_lock);
1071 sk->sk_user_data = NULL;
1072 sk->sk_data_ready = tcp_conn->old_data_ready;
1073 sk->sk_state_change = tcp_conn->old_state_change;
1074 sk->sk_write_space = tcp_conn->old_write_space;
1075 sk->sk_no_check = 0;
1076 write_unlock_bh(&sk->sk_callback_lock);
1077 }
1078
1079 /**
1080 * iscsi_send - generic send routine
1081 * @sk: kernel's socket
1082 * @buf: buffer to write from
1083 * @size: actual size to write
1084 * @flags: socket's flags
1085 */
1086 static inline int
1087 iscsi_send(struct iscsi_conn *conn, struct iscsi_buf *buf, int size, int flags)
1088 {
1089 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1090 struct socket *sk = tcp_conn->sock;
1091 int offset = buf->sg.offset + buf->sent, res;
1092
1093 /*
1094 * if we got use_sg=0 or are sending something we kmallocd
1095 * then we did not have to do kmap (kmap returns page_address)
1096 *
1097 * if we got use_sg > 0, but had to drop down, we do not
1098 * set clustering so this should only happen for that
1099 * slab case.
1100 */
1101 if (buf->use_sendmsg)
1102 res = sock_no_sendpage(sk, sg_page(&buf->sg), offset, size, flags);
1103 else
1104 res = tcp_conn->sendpage(sk, sg_page(&buf->sg), offset, size, flags);
1105
1106 if (res >= 0) {
1107 conn->txdata_octets += res;
1108 buf->sent += res;
1109 return res;
1110 }
1111
1112 tcp_conn->sendpage_failures_cnt++;
1113 if (res == -EAGAIN)
1114 res = -ENOBUFS;
1115 else
1116 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1117 return res;
1118 }
1119
1120 /**
1121 * iscsi_sendhdr - send PDU Header via tcp_sendpage()
1122 * @conn: iscsi connection
1123 * @buf: buffer to write from
1124 * @datalen: lenght of data to be sent after the header
1125 *
1126 * Notes:
1127 * (Tx, Fast Path)
1128 **/
1129 static inline int
1130 iscsi_sendhdr(struct iscsi_conn *conn, struct iscsi_buf *buf, int datalen)
1131 {
1132 int flags = 0; /* MSG_DONTWAIT; */
1133 int res, size;
1134
1135 size = buf->sg.length - buf->sent;
1136 BUG_ON(buf->sent + size > buf->sg.length);
1137 if (buf->sent + size != buf->sg.length || datalen)
1138 flags |= MSG_MORE;
1139
1140 res = iscsi_send(conn, buf, size, flags);
1141 debug_tcp("sendhdr %d bytes, sent %d res %d\n", size, buf->sent, res);
1142 if (res >= 0) {
1143 if (size != res)
1144 return -EAGAIN;
1145 return 0;
1146 }
1147
1148 return res;
1149 }
1150
1151 /**
1152 * iscsi_sendpage - send one page of iSCSI Data-Out.
1153 * @conn: iscsi connection
1154 * @buf: buffer to write from
1155 * @count: remaining data
1156 * @sent: number of bytes sent
1157 *
1158 * Notes:
1159 * (Tx, Fast Path)
1160 **/
1161 static inline int
1162 iscsi_sendpage(struct iscsi_conn *conn, struct iscsi_buf *buf,
1163 int *count, int *sent)
1164 {
1165 int flags = 0; /* MSG_DONTWAIT; */
1166 int res, size;
1167
1168 size = buf->sg.length - buf->sent;
1169 BUG_ON(buf->sent + size > buf->sg.length);
1170 if (size > *count)
1171 size = *count;
1172 if (buf->sent + size != buf->sg.length || *count != size)
1173 flags |= MSG_MORE;
1174
1175 res = iscsi_send(conn, buf, size, flags);
1176 debug_tcp("sendpage: %d bytes, sent %d left %d sent %d res %d\n",
1177 size, buf->sent, *count, *sent, res);
1178 if (res >= 0) {
1179 *count -= res;
1180 *sent += res;
1181 if (size != res)
1182 return -EAGAIN;
1183 return 0;
1184 }
1185
1186 return res;
1187 }
1188
1189 static inline void
1190 iscsi_data_digest_init(struct iscsi_tcp_conn *tcp_conn,
1191 struct iscsi_tcp_cmd_task *tcp_ctask)
1192 {
1193 crypto_hash_init(&tcp_conn->tx_hash);
1194 tcp_ctask->digest_count = 4;
1195 }
1196
1197 /**
1198 * iscsi_solicit_data_cont - initialize next Data-Out
1199 * @conn: iscsi connection
1200 * @ctask: scsi command task
1201 * @r2t: R2T info
1202 * @left: bytes left to transfer
1203 *
1204 * Notes:
1205 * Initialize next Data-Out within this R2T sequence and continue
1206 * to process next Scatter-Gather element(if any) of this SCSI command.
1207 *
1208 * Called under connection lock.
1209 **/
1210 static void
1211 iscsi_solicit_data_cont(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
1212 struct iscsi_r2t_info *r2t, int left)
1213 {
1214 struct iscsi_data *hdr;
1215 int new_offset;
1216
1217 hdr = &r2t->dtask.hdr;
1218 memset(hdr, 0, sizeof(struct iscsi_data));
1219 hdr->ttt = r2t->ttt;
1220 hdr->datasn = cpu_to_be32(r2t->solicit_datasn);
1221 r2t->solicit_datasn++;
1222 hdr->opcode = ISCSI_OP_SCSI_DATA_OUT;
1223 memcpy(hdr->lun, ctask->hdr->lun, sizeof(hdr->lun));
1224 hdr->itt = ctask->hdr->itt;
1225 hdr->exp_statsn = r2t->exp_statsn;
1226 new_offset = r2t->data_offset + r2t->sent;
1227 hdr->offset = cpu_to_be32(new_offset);
1228 if (left > conn->max_xmit_dlength) {
1229 hton24(hdr->dlength, conn->max_xmit_dlength);
1230 r2t->data_count = conn->max_xmit_dlength;
1231 } else {
1232 hton24(hdr->dlength, left);
1233 r2t->data_count = left;
1234 hdr->flags = ISCSI_FLAG_CMD_FINAL;
1235 }
1236 conn->dataout_pdus_cnt++;
1237
1238 iscsi_buf_init_iov(&r2t->headbuf, (char*)hdr,
1239 sizeof(struct iscsi_hdr));
1240
1241 if (iscsi_buf_left(&r2t->sendbuf))
1242 return;
1243
1244 iscsi_buf_init_sg(&r2t->sendbuf, r2t->sg);
1245 r2t->sg += 1;
1246 }
1247
1248 static void iscsi_set_padding(struct iscsi_tcp_cmd_task *tcp_ctask,
1249 unsigned long len)
1250 {
1251 tcp_ctask->pad_count = len & (ISCSI_PAD_LEN - 1);
1252 if (!tcp_ctask->pad_count)
1253 return;
1254
1255 tcp_ctask->pad_count = ISCSI_PAD_LEN - tcp_ctask->pad_count;
1256 debug_scsi("write padding %d bytes\n", tcp_ctask->pad_count);
1257 tcp_ctask->xmstate |= XMSTATE_W_PAD;
1258 }
1259
1260 /**
1261 * iscsi_tcp_cmd_init - Initialize iSCSI SCSI_READ or SCSI_WRITE commands
1262 * @conn: iscsi connection
1263 * @ctask: scsi command task
1264 * @sc: scsi command
1265 **/
1266 static void
1267 iscsi_tcp_cmd_init(struct iscsi_cmd_task *ctask)
1268 {
1269 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1270
1271 BUG_ON(__kfifo_len(tcp_ctask->r2tqueue));
1272 tcp_ctask->xmstate = XMSTATE_CMD_HDR_INIT;
1273 }
1274
1275 /**
1276 * iscsi_tcp_mtask_xmit - xmit management(immediate) task
1277 * @conn: iscsi connection
1278 * @mtask: task management task
1279 *
1280 * Notes:
1281 * The function can return -EAGAIN in which case caller must
1282 * call it again later, or recover. '0' return code means successful
1283 * xmit.
1284 *
1285 * Management xmit state machine consists of these states:
1286 * XMSTATE_IMM_HDR_INIT - calculate digest of PDU Header
1287 * XMSTATE_IMM_HDR - PDU Header xmit in progress
1288 * XMSTATE_IMM_DATA - PDU Data xmit in progress
1289 * XMSTATE_IDLE - management PDU is done
1290 **/
1291 static int
1292 iscsi_tcp_mtask_xmit(struct iscsi_conn *conn, struct iscsi_mgmt_task *mtask)
1293 {
1294 struct iscsi_tcp_mgmt_task *tcp_mtask = mtask->dd_data;
1295 int rc;
1296
1297 debug_scsi("mtask deq [cid %d state %x itt 0x%x]\n",
1298 conn->id, tcp_mtask->xmstate, mtask->itt);
1299
1300 if (tcp_mtask->xmstate & XMSTATE_IMM_HDR_INIT) {
1301 iscsi_buf_init_iov(&tcp_mtask->headbuf, (char*)mtask->hdr,
1302 sizeof(struct iscsi_hdr));
1303
1304 if (mtask->data_count) {
1305 tcp_mtask->xmstate |= XMSTATE_IMM_DATA;
1306 iscsi_buf_init_iov(&tcp_mtask->sendbuf,
1307 (char*)mtask->data,
1308 mtask->data_count);
1309 }
1310
1311 if (conn->c_stage != ISCSI_CONN_INITIAL_STAGE &&
1312 conn->stop_stage != STOP_CONN_RECOVER &&
1313 conn->hdrdgst_en)
1314 iscsi_hdr_digest(conn, &tcp_mtask->headbuf,
1315 (u8*)tcp_mtask->hdrext);
1316
1317 tcp_mtask->sent = 0;
1318 tcp_mtask->xmstate &= ~XMSTATE_IMM_HDR_INIT;
1319 tcp_mtask->xmstate |= XMSTATE_IMM_HDR;
1320 }
1321
1322 if (tcp_mtask->xmstate & XMSTATE_IMM_HDR) {
1323 rc = iscsi_sendhdr(conn, &tcp_mtask->headbuf,
1324 mtask->data_count);
1325 if (rc)
1326 return rc;
1327 tcp_mtask->xmstate &= ~XMSTATE_IMM_HDR;
1328 }
1329
1330 if (tcp_mtask->xmstate & XMSTATE_IMM_DATA) {
1331 BUG_ON(!mtask->data_count);
1332 tcp_mtask->xmstate &= ~XMSTATE_IMM_DATA;
1333 /* FIXME: implement.
1334 * Virtual buffer could be spreaded across multiple pages...
1335 */
1336 do {
1337 int rc;
1338
1339 rc = iscsi_sendpage(conn, &tcp_mtask->sendbuf,
1340 &mtask->data_count, &tcp_mtask->sent);
1341 if (rc) {
1342 tcp_mtask->xmstate |= XMSTATE_IMM_DATA;
1343 return rc;
1344 }
1345 } while (mtask->data_count);
1346 }
1347
1348 BUG_ON(tcp_mtask->xmstate != XMSTATE_IDLE);
1349 if (mtask->hdr->itt == RESERVED_ITT) {
1350 struct iscsi_session *session = conn->session;
1351
1352 spin_lock_bh(&session->lock);
1353 list_del(&conn->mtask->running);
1354 __kfifo_put(session->mgmtpool.queue, (void*)&conn->mtask,
1355 sizeof(void*));
1356 spin_unlock_bh(&session->lock);
1357 }
1358 return 0;
1359 }
1360
1361 static int
1362 iscsi_send_cmd_hdr(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1363 {
1364 struct scsi_cmnd *sc = ctask->sc;
1365 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1366 int rc = 0;
1367
1368 if (tcp_ctask->xmstate & XMSTATE_CMD_HDR_INIT) {
1369 tcp_ctask->sent = 0;
1370 tcp_ctask->sg_count = 0;
1371 tcp_ctask->exp_datasn = 0;
1372
1373 if (sc->sc_data_direction == DMA_TO_DEVICE) {
1374 struct scatterlist *sg = scsi_sglist(sc);
1375
1376 iscsi_buf_init_sg(&tcp_ctask->sendbuf, sg);
1377 tcp_ctask->sg = sg + 1;
1378 tcp_ctask->bad_sg = sg + scsi_sg_count(sc);
1379
1380 debug_scsi("cmd [itt 0x%x total %d imm_data %d "
1381 "unsol count %d, unsol offset %d]\n",
1382 ctask->itt, scsi_bufflen(sc),
1383 ctask->imm_count, ctask->unsol_count,
1384 ctask->unsol_offset);
1385 }
1386
1387 iscsi_buf_init_iov(&tcp_ctask->headbuf, (char*)ctask->hdr,
1388 sizeof(struct iscsi_hdr));
1389
1390 if (conn->hdrdgst_en)
1391 iscsi_hdr_digest(conn, &tcp_ctask->headbuf,
1392 (u8*)tcp_ctask->hdrext);
1393 tcp_ctask->xmstate &= ~XMSTATE_CMD_HDR_INIT;
1394 tcp_ctask->xmstate |= XMSTATE_CMD_HDR_XMIT;
1395 }
1396
1397 if (tcp_ctask->xmstate & XMSTATE_CMD_HDR_XMIT) {
1398 rc = iscsi_sendhdr(conn, &tcp_ctask->headbuf, ctask->imm_count);
1399 if (rc)
1400 return rc;
1401 tcp_ctask->xmstate &= ~XMSTATE_CMD_HDR_XMIT;
1402
1403 if (sc->sc_data_direction != DMA_TO_DEVICE)
1404 return 0;
1405
1406 if (ctask->imm_count) {
1407 tcp_ctask->xmstate |= XMSTATE_IMM_DATA;
1408 iscsi_set_padding(tcp_ctask, ctask->imm_count);
1409
1410 if (ctask->conn->datadgst_en) {
1411 iscsi_data_digest_init(ctask->conn->dd_data,
1412 tcp_ctask);
1413 tcp_ctask->immdigest = 0;
1414 }
1415 }
1416
1417 if (ctask->unsol_count)
1418 tcp_ctask->xmstate |=
1419 XMSTATE_UNS_HDR | XMSTATE_UNS_INIT;
1420 }
1421 return rc;
1422 }
1423
1424 static int
1425 iscsi_send_padding(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1426 {
1427 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1428 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1429 int sent = 0, rc;
1430
1431 if (tcp_ctask->xmstate & XMSTATE_W_PAD) {
1432 iscsi_buf_init_iov(&tcp_ctask->sendbuf, (char*)&tcp_ctask->pad,
1433 tcp_ctask->pad_count);
1434 if (conn->datadgst_en)
1435 crypto_hash_update(&tcp_conn->tx_hash,
1436 &tcp_ctask->sendbuf.sg,
1437 tcp_ctask->sendbuf.sg.length);
1438 } else if (!(tcp_ctask->xmstate & XMSTATE_W_RESEND_PAD))
1439 return 0;
1440
1441 tcp_ctask->xmstate &= ~XMSTATE_W_PAD;
1442 tcp_ctask->xmstate &= ~XMSTATE_W_RESEND_PAD;
1443 debug_scsi("sending %d pad bytes for itt 0x%x\n",
1444 tcp_ctask->pad_count, ctask->itt);
1445 rc = iscsi_sendpage(conn, &tcp_ctask->sendbuf, &tcp_ctask->pad_count,
1446 &sent);
1447 if (rc) {
1448 debug_scsi("padding send failed %d\n", rc);
1449 tcp_ctask->xmstate |= XMSTATE_W_RESEND_PAD;
1450 }
1451 return rc;
1452 }
1453
1454 static int
1455 iscsi_send_digest(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
1456 struct iscsi_buf *buf, uint32_t *digest)
1457 {
1458 struct iscsi_tcp_cmd_task *tcp_ctask;
1459 struct iscsi_tcp_conn *tcp_conn;
1460 int rc, sent = 0;
1461
1462 if (!conn->datadgst_en)
1463 return 0;
1464
1465 tcp_ctask = ctask->dd_data;
1466 tcp_conn = conn->dd_data;
1467
1468 if (!(tcp_ctask->xmstate & XMSTATE_W_RESEND_DATA_DIGEST)) {
1469 crypto_hash_final(&tcp_conn->tx_hash, (u8*)digest);
1470 iscsi_buf_init_iov(buf, (char*)digest, 4);
1471 }
1472 tcp_ctask->xmstate &= ~XMSTATE_W_RESEND_DATA_DIGEST;
1473
1474 rc = iscsi_sendpage(conn, buf, &tcp_ctask->digest_count, &sent);
1475 if (!rc)
1476 debug_scsi("sent digest 0x%x for itt 0x%x\n", *digest,
1477 ctask->itt);
1478 else {
1479 debug_scsi("sending digest 0x%x failed for itt 0x%x!\n",
1480 *digest, ctask->itt);
1481 tcp_ctask->xmstate |= XMSTATE_W_RESEND_DATA_DIGEST;
1482 }
1483 return rc;
1484 }
1485
1486 static int
1487 iscsi_send_data(struct iscsi_cmd_task *ctask, struct iscsi_buf *sendbuf,
1488 struct scatterlist **sg, int *sent, int *count,
1489 struct iscsi_buf *digestbuf, uint32_t *digest)
1490 {
1491 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1492 struct iscsi_conn *conn = ctask->conn;
1493 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1494 int rc, buf_sent, offset;
1495
1496 while (*count) {
1497 buf_sent = 0;
1498 offset = sendbuf->sent;
1499
1500 rc = iscsi_sendpage(conn, sendbuf, count, &buf_sent);
1501 *sent = *sent + buf_sent;
1502 if (buf_sent && conn->datadgst_en)
1503 partial_sg_digest_update(&tcp_conn->tx_hash,
1504 &sendbuf->sg, sendbuf->sg.offset + offset,
1505 buf_sent);
1506 if (!iscsi_buf_left(sendbuf) && *sg != tcp_ctask->bad_sg) {
1507 iscsi_buf_init_sg(sendbuf, *sg);
1508 *sg = *sg + 1;
1509 }
1510
1511 if (rc)
1512 return rc;
1513 }
1514
1515 rc = iscsi_send_padding(conn, ctask);
1516 if (rc)
1517 return rc;
1518
1519 return iscsi_send_digest(conn, ctask, digestbuf, digest);
1520 }
1521
1522 static int
1523 iscsi_send_unsol_hdr(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1524 {
1525 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1526 struct iscsi_data_task *dtask;
1527 int rc;
1528
1529 tcp_ctask->xmstate |= XMSTATE_UNS_DATA;
1530 if (tcp_ctask->xmstate & XMSTATE_UNS_INIT) {
1531 dtask = &tcp_ctask->unsol_dtask;
1532
1533 iscsi_prep_unsolicit_data_pdu(ctask, &dtask->hdr);
1534 iscsi_buf_init_iov(&tcp_ctask->headbuf, (char*)&dtask->hdr,
1535 sizeof(struct iscsi_hdr));
1536 if (conn->hdrdgst_en)
1537 iscsi_hdr_digest(conn, &tcp_ctask->headbuf,
1538 (u8*)dtask->hdrext);
1539
1540 tcp_ctask->xmstate &= ~XMSTATE_UNS_INIT;
1541 iscsi_set_padding(tcp_ctask, ctask->data_count);
1542 }
1543
1544 rc = iscsi_sendhdr(conn, &tcp_ctask->headbuf, ctask->data_count);
1545 if (rc) {
1546 tcp_ctask->xmstate &= ~XMSTATE_UNS_DATA;
1547 tcp_ctask->xmstate |= XMSTATE_UNS_HDR;
1548 return rc;
1549 }
1550
1551 if (conn->datadgst_en) {
1552 dtask = &tcp_ctask->unsol_dtask;
1553 iscsi_data_digest_init(ctask->conn->dd_data, tcp_ctask);
1554 dtask->digest = 0;
1555 }
1556
1557 debug_scsi("uns dout [itt 0x%x dlen %d sent %d]\n",
1558 ctask->itt, ctask->unsol_count, tcp_ctask->sent);
1559 return 0;
1560 }
1561
1562 static int
1563 iscsi_send_unsol_pdu(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1564 {
1565 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1566 int rc;
1567
1568 if (tcp_ctask->xmstate & XMSTATE_UNS_HDR) {
1569 BUG_ON(!ctask->unsol_count);
1570 tcp_ctask->xmstate &= ~XMSTATE_UNS_HDR;
1571 send_hdr:
1572 rc = iscsi_send_unsol_hdr(conn, ctask);
1573 if (rc)
1574 return rc;
1575 }
1576
1577 if (tcp_ctask->xmstate & XMSTATE_UNS_DATA) {
1578 struct iscsi_data_task *dtask = &tcp_ctask->unsol_dtask;
1579 int start = tcp_ctask->sent;
1580
1581 rc = iscsi_send_data(ctask, &tcp_ctask->sendbuf, &tcp_ctask->sg,
1582 &tcp_ctask->sent, &ctask->data_count,
1583 &dtask->digestbuf, &dtask->digest);
1584 ctask->unsol_count -= tcp_ctask->sent - start;
1585 if (rc)
1586 return rc;
1587 tcp_ctask->xmstate &= ~XMSTATE_UNS_DATA;
1588 /*
1589 * Done with the Data-Out. Next, check if we need
1590 * to send another unsolicited Data-Out.
1591 */
1592 if (ctask->unsol_count) {
1593 debug_scsi("sending more uns\n");
1594 tcp_ctask->xmstate |= XMSTATE_UNS_INIT;
1595 goto send_hdr;
1596 }
1597 }
1598 return 0;
1599 }
1600
1601 static int iscsi_send_sol_pdu(struct iscsi_conn *conn,
1602 struct iscsi_cmd_task *ctask)
1603 {
1604 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1605 struct iscsi_session *session = conn->session;
1606 struct iscsi_r2t_info *r2t;
1607 struct iscsi_data_task *dtask;
1608 int left, rc;
1609
1610 if (tcp_ctask->xmstate & XMSTATE_SOL_HDR_INIT) {
1611 if (!tcp_ctask->r2t) {
1612 spin_lock_bh(&session->lock);
1613 __kfifo_get(tcp_ctask->r2tqueue, (void*)&tcp_ctask->r2t,
1614 sizeof(void*));
1615 spin_unlock_bh(&session->lock);
1616 }
1617 send_hdr:
1618 r2t = tcp_ctask->r2t;
1619 dtask = &r2t->dtask;
1620
1621 if (conn->hdrdgst_en)
1622 iscsi_hdr_digest(conn, &r2t->headbuf,
1623 (u8*)dtask->hdrext);
1624 tcp_ctask->xmstate &= ~XMSTATE_SOL_HDR_INIT;
1625 tcp_ctask->xmstate |= XMSTATE_SOL_HDR;
1626 }
1627
1628 if (tcp_ctask->xmstate & XMSTATE_SOL_HDR) {
1629 r2t = tcp_ctask->r2t;
1630 dtask = &r2t->dtask;
1631
1632 rc = iscsi_sendhdr(conn, &r2t->headbuf, r2t->data_count);
1633 if (rc)
1634 return rc;
1635 tcp_ctask->xmstate &= ~XMSTATE_SOL_HDR;
1636 tcp_ctask->xmstate |= XMSTATE_SOL_DATA;
1637
1638 if (conn->datadgst_en) {
1639 iscsi_data_digest_init(conn->dd_data, tcp_ctask);
1640 dtask->digest = 0;
1641 }
1642
1643 iscsi_set_padding(tcp_ctask, r2t->data_count);
1644 debug_scsi("sol dout [dsn %d itt 0x%x dlen %d sent %d]\n",
1645 r2t->solicit_datasn - 1, ctask->itt, r2t->data_count,
1646 r2t->sent);
1647 }
1648
1649 if (tcp_ctask->xmstate & XMSTATE_SOL_DATA) {
1650 r2t = tcp_ctask->r2t;
1651 dtask = &r2t->dtask;
1652
1653 rc = iscsi_send_data(ctask, &r2t->sendbuf, &r2t->sg,
1654 &r2t->sent, &r2t->data_count,
1655 &dtask->digestbuf, &dtask->digest);
1656 if (rc)
1657 return rc;
1658 tcp_ctask->xmstate &= ~XMSTATE_SOL_DATA;
1659
1660 /*
1661 * Done with this Data-Out. Next, check if we have
1662 * to send another Data-Out for this R2T.
1663 */
1664 BUG_ON(r2t->data_length - r2t->sent < 0);
1665 left = r2t->data_length - r2t->sent;
1666 if (left) {
1667 iscsi_solicit_data_cont(conn, ctask, r2t, left);
1668 goto send_hdr;
1669 }
1670
1671 /*
1672 * Done with this R2T. Check if there are more
1673 * outstanding R2Ts ready to be processed.
1674 */
1675 spin_lock_bh(&session->lock);
1676 tcp_ctask->r2t = NULL;
1677 __kfifo_put(tcp_ctask->r2tpool.queue, (void*)&r2t,
1678 sizeof(void*));
1679 if (__kfifo_get(tcp_ctask->r2tqueue, (void*)&r2t,
1680 sizeof(void*))) {
1681 tcp_ctask->r2t = r2t;
1682 spin_unlock_bh(&session->lock);
1683 goto send_hdr;
1684 }
1685 spin_unlock_bh(&session->lock);
1686 }
1687 return 0;
1688 }
1689
1690 /**
1691 * iscsi_tcp_ctask_xmit - xmit normal PDU task
1692 * @conn: iscsi connection
1693 * @ctask: iscsi command task
1694 *
1695 * Notes:
1696 * The function can return -EAGAIN in which case caller must
1697 * call it again later, or recover. '0' return code means successful
1698 * xmit.
1699 * The function is devided to logical helpers (above) for the different
1700 * xmit stages.
1701 *
1702 *iscsi_send_cmd_hdr()
1703 * XMSTATE_CMD_HDR_INIT - prepare Header and Data buffers Calculate
1704 * Header Digest
1705 * XMSTATE_CMD_HDR_XMIT - Transmit header in progress
1706 *
1707 *iscsi_send_padding
1708 * XMSTATE_W_PAD - Prepare and send pading
1709 * XMSTATE_W_RESEND_PAD - retry send pading
1710 *
1711 *iscsi_send_digest
1712 * XMSTATE_W_RESEND_DATA_DIGEST - Finalize and send Data Digest
1713 * XMSTATE_W_RESEND_DATA_DIGEST - retry sending digest
1714 *
1715 *iscsi_send_unsol_hdr
1716 * XMSTATE_UNS_INIT - prepare un-solicit data header and digest
1717 * XMSTATE_UNS_HDR - send un-solicit header
1718 *
1719 *iscsi_send_unsol_pdu
1720 * XMSTATE_UNS_DATA - send un-solicit data in progress
1721 *
1722 *iscsi_send_sol_pdu
1723 * XMSTATE_SOL_HDR_INIT - solicit data header and digest initialize
1724 * XMSTATE_SOL_HDR - send solicit header
1725 * XMSTATE_SOL_DATA - send solicit data
1726 *
1727 *iscsi_tcp_ctask_xmit
1728 * XMSTATE_IMM_DATA - xmit managment data (??)
1729 **/
1730 static int
1731 iscsi_tcp_ctask_xmit(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1732 {
1733 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1734 int rc = 0;
1735
1736 debug_scsi("ctask deq [cid %d xmstate %x itt 0x%x]\n",
1737 conn->id, tcp_ctask->xmstate, ctask->itt);
1738
1739 rc = iscsi_send_cmd_hdr(conn, ctask);
1740 if (rc)
1741 return rc;
1742 if (ctask->sc->sc_data_direction != DMA_TO_DEVICE)
1743 return 0;
1744
1745 if (tcp_ctask->xmstate & XMSTATE_IMM_DATA) {
1746 rc = iscsi_send_data(ctask, &tcp_ctask->sendbuf, &tcp_ctask->sg,
1747 &tcp_ctask->sent, &ctask->imm_count,
1748 &tcp_ctask->immbuf, &tcp_ctask->immdigest);
1749 if (rc)
1750 return rc;
1751 tcp_ctask->xmstate &= ~XMSTATE_IMM_DATA;
1752 }
1753
1754 rc = iscsi_send_unsol_pdu(conn, ctask);
1755 if (rc)
1756 return rc;
1757
1758 rc = iscsi_send_sol_pdu(conn, ctask);
1759 if (rc)
1760 return rc;
1761
1762 return rc;
1763 }
1764
1765 static struct iscsi_cls_conn *
1766 iscsi_tcp_conn_create(struct iscsi_cls_session *cls_session, uint32_t conn_idx)
1767 {
1768 struct iscsi_conn *conn;
1769 struct iscsi_cls_conn *cls_conn;
1770 struct iscsi_tcp_conn *tcp_conn;
1771
1772 cls_conn = iscsi_conn_setup(cls_session, conn_idx);
1773 if (!cls_conn)
1774 return NULL;
1775 conn = cls_conn->dd_data;
1776 /*
1777 * due to strange issues with iser these are not set
1778 * in iscsi_conn_setup
1779 */
1780 conn->max_recv_dlength = ISCSI_DEF_MAX_RECV_SEG_LEN;
1781
1782 tcp_conn = kzalloc(sizeof(*tcp_conn), GFP_KERNEL);
1783 if (!tcp_conn)
1784 goto tcp_conn_alloc_fail;
1785
1786 conn->dd_data = tcp_conn;
1787 tcp_conn->iscsi_conn = conn;
1788 tcp_conn->in_progress = IN_PROGRESS_WAIT_HEADER;
1789 /* initial operational parameters */
1790 tcp_conn->hdr_size = sizeof(struct iscsi_hdr);
1791
1792 tcp_conn->tx_hash.tfm = crypto_alloc_hash("crc32c", 0,
1793 CRYPTO_ALG_ASYNC);
1794 tcp_conn->tx_hash.flags = 0;
1795 if (IS_ERR(tcp_conn->tx_hash.tfm)) {
1796 printk(KERN_ERR "Could not create connection due to crc32c "
1797 "loading error %ld. Make sure the crc32c module is "
1798 "built as a module or into the kernel\n",
1799 PTR_ERR(tcp_conn->tx_hash.tfm));
1800 goto free_tcp_conn;
1801 }
1802
1803 tcp_conn->rx_hash.tfm = crypto_alloc_hash("crc32c", 0,
1804 CRYPTO_ALG_ASYNC);
1805 tcp_conn->rx_hash.flags = 0;
1806 if (IS_ERR(tcp_conn->rx_hash.tfm)) {
1807 printk(KERN_ERR "Could not create connection due to crc32c "
1808 "loading error %ld. Make sure the crc32c module is "
1809 "built as a module or into the kernel\n",
1810 PTR_ERR(tcp_conn->rx_hash.tfm));
1811 goto free_tx_tfm;
1812 }
1813
1814 return cls_conn;
1815
1816 free_tx_tfm:
1817 crypto_free_hash(tcp_conn->tx_hash.tfm);
1818 free_tcp_conn:
1819 kfree(tcp_conn);
1820 tcp_conn_alloc_fail:
1821 iscsi_conn_teardown(cls_conn);
1822 return NULL;
1823 }
1824
1825 static void
1826 iscsi_tcp_release_conn(struct iscsi_conn *conn)
1827 {
1828 struct iscsi_session *session = conn->session;
1829 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1830 struct socket *sock = tcp_conn->sock;
1831
1832 if (!sock)
1833 return;
1834
1835 sock_hold(sock->sk);
1836 iscsi_conn_restore_callbacks(tcp_conn);
1837 sock_put(sock->sk);
1838
1839 spin_lock_bh(&session->lock);
1840 tcp_conn->sock = NULL;
1841 conn->recv_lock = NULL;
1842 spin_unlock_bh(&session->lock);
1843 sockfd_put(sock);
1844 }
1845
1846 static void
1847 iscsi_tcp_conn_destroy(struct iscsi_cls_conn *cls_conn)
1848 {
1849 struct iscsi_conn *conn = cls_conn->dd_data;
1850 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1851
1852 iscsi_tcp_release_conn(conn);
1853 iscsi_conn_teardown(cls_conn);
1854
1855 if (tcp_conn->tx_hash.tfm)
1856 crypto_free_hash(tcp_conn->tx_hash.tfm);
1857 if (tcp_conn->rx_hash.tfm)
1858 crypto_free_hash(tcp_conn->rx_hash.tfm);
1859
1860 kfree(tcp_conn);
1861 }
1862
1863 static void
1864 iscsi_tcp_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
1865 {
1866 struct iscsi_conn *conn = cls_conn->dd_data;
1867 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1868
1869 iscsi_conn_stop(cls_conn, flag);
1870 iscsi_tcp_release_conn(conn);
1871 tcp_conn->hdr_size = sizeof(struct iscsi_hdr);
1872 }
1873
1874 static int iscsi_tcp_get_addr(struct iscsi_conn *conn, struct socket *sock,
1875 char *buf, int *port,
1876 int (*getname)(struct socket *, struct sockaddr *,
1877 int *addrlen))
1878 {
1879 struct sockaddr_storage *addr;
1880 struct sockaddr_in6 *sin6;
1881 struct sockaddr_in *sin;
1882 int rc = 0, len;
1883
1884 addr = kmalloc(sizeof(*addr), GFP_KERNEL);
1885 if (!addr)
1886 return -ENOMEM;
1887
1888 if (getname(sock, (struct sockaddr *) addr, &len)) {
1889 rc = -ENODEV;
1890 goto free_addr;
1891 }
1892
1893 switch (addr->ss_family) {
1894 case AF_INET:
1895 sin = (struct sockaddr_in *)addr;
1896 spin_lock_bh(&conn->session->lock);
1897 sprintf(buf, NIPQUAD_FMT, NIPQUAD(sin->sin_addr.s_addr));
1898 *port = be16_to_cpu(sin->sin_port);
1899 spin_unlock_bh(&conn->session->lock);
1900 break;
1901 case AF_INET6:
1902 sin6 = (struct sockaddr_in6 *)addr;
1903 spin_lock_bh(&conn->session->lock);
1904 sprintf(buf, NIP6_FMT, NIP6(sin6->sin6_addr));
1905 *port = be16_to_cpu(sin6->sin6_port);
1906 spin_unlock_bh(&conn->session->lock);
1907 break;
1908 }
1909 free_addr:
1910 kfree(addr);
1911 return rc;
1912 }
1913
1914 static int
1915 iscsi_tcp_conn_bind(struct iscsi_cls_session *cls_session,
1916 struct iscsi_cls_conn *cls_conn, uint64_t transport_eph,
1917 int is_leading)
1918 {
1919 struct iscsi_conn *conn = cls_conn->dd_data;
1920 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1921 struct sock *sk;
1922 struct socket *sock;
1923 int err;
1924
1925 /* lookup for existing socket */
1926 sock = sockfd_lookup((int)transport_eph, &err);
1927 if (!sock) {
1928 printk(KERN_ERR "iscsi_tcp: sockfd_lookup failed %d\n", err);
1929 return -EEXIST;
1930 }
1931 /*
1932 * copy these values now because if we drop the session
1933 * userspace may still want to query the values since we will
1934 * be using them for the reconnect
1935 */
1936 err = iscsi_tcp_get_addr(conn, sock, conn->portal_address,
1937 &conn->portal_port, kernel_getpeername);
1938 if (err)
1939 goto free_socket;
1940
1941 err = iscsi_tcp_get_addr(conn, sock, conn->local_address,
1942 &conn->local_port, kernel_getsockname);
1943 if (err)
1944 goto free_socket;
1945
1946 err = iscsi_conn_bind(cls_session, cls_conn, is_leading);
1947 if (err)
1948 goto free_socket;
1949
1950 /* bind iSCSI connection and socket */
1951 tcp_conn->sock = sock;
1952
1953 /* setup Socket parameters */
1954 sk = sock->sk;
1955 sk->sk_reuse = 1;
1956 sk->sk_sndtimeo = 15 * HZ; /* FIXME: make it configurable */
1957 sk->sk_allocation = GFP_ATOMIC;
1958
1959 /* FIXME: disable Nagle's algorithm */
1960
1961 /*
1962 * Intercept TCP callbacks for sendfile like receive
1963 * processing.
1964 */
1965 conn->recv_lock = &sk->sk_callback_lock;
1966 iscsi_conn_set_callbacks(conn);
1967 tcp_conn->sendpage = tcp_conn->sock->ops->sendpage;
1968 /*
1969 * set receive state machine into initial state
1970 */
1971 tcp_conn->in_progress = IN_PROGRESS_WAIT_HEADER;
1972 return 0;
1973
1974 free_socket:
1975 sockfd_put(sock);
1976 return err;
1977 }
1978
1979 /* called with host lock */
1980 static void
1981 iscsi_tcp_mgmt_init(struct iscsi_conn *conn, struct iscsi_mgmt_task *mtask)
1982 {
1983 struct iscsi_tcp_mgmt_task *tcp_mtask = mtask->dd_data;
1984 tcp_mtask->xmstate = XMSTATE_IMM_HDR_INIT;
1985 }
1986
1987 static int
1988 iscsi_r2tpool_alloc(struct iscsi_session *session)
1989 {
1990 int i;
1991 int cmd_i;
1992
1993 /*
1994 * initialize per-task: R2T pool and xmit queue
1995 */
1996 for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
1997 struct iscsi_cmd_task *ctask = session->cmds[cmd_i];
1998 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1999
2000 /*
2001 * pre-allocated x4 as much r2ts to handle race when
2002 * target acks DataOut faster than we data_xmit() queues
2003 * could replenish r2tqueue.
2004 */
2005
2006 /* R2T pool */
2007 if (iscsi_pool_init(&tcp_ctask->r2tpool, session->max_r2t * 4,
2008 (void***)&tcp_ctask->r2ts,
2009 sizeof(struct iscsi_r2t_info))) {
2010 goto r2t_alloc_fail;
2011 }
2012
2013 /* R2T xmit queue */
2014 tcp_ctask->r2tqueue = kfifo_alloc(
2015 session->max_r2t * 4 * sizeof(void*), GFP_KERNEL, NULL);
2016 if (tcp_ctask->r2tqueue == ERR_PTR(-ENOMEM)) {
2017 iscsi_pool_free(&tcp_ctask->r2tpool,
2018 (void**)tcp_ctask->r2ts);
2019 goto r2t_alloc_fail;
2020 }
2021 }
2022
2023 return 0;
2024
2025 r2t_alloc_fail:
2026 for (i = 0; i < cmd_i; i++) {
2027 struct iscsi_cmd_task *ctask = session->cmds[i];
2028 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
2029
2030 kfifo_free(tcp_ctask->r2tqueue);
2031 iscsi_pool_free(&tcp_ctask->r2tpool,
2032 (void**)tcp_ctask->r2ts);
2033 }
2034 return -ENOMEM;
2035 }
2036
2037 static void
2038 iscsi_r2tpool_free(struct iscsi_session *session)
2039 {
2040 int i;
2041
2042 for (i = 0; i < session->cmds_max; i++) {
2043 struct iscsi_cmd_task *ctask = session->cmds[i];
2044 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
2045
2046 kfifo_free(tcp_ctask->r2tqueue);
2047 iscsi_pool_free(&tcp_ctask->r2tpool,
2048 (void**)tcp_ctask->r2ts);
2049 }
2050 }
2051
2052 static int
2053 iscsi_conn_set_param(struct iscsi_cls_conn *cls_conn, enum iscsi_param param,
2054 char *buf, int buflen)
2055 {
2056 struct iscsi_conn *conn = cls_conn->dd_data;
2057 struct iscsi_session *session = conn->session;
2058 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
2059 int value;
2060
2061 switch(param) {
2062 case ISCSI_PARAM_HDRDGST_EN:
2063 iscsi_set_param(cls_conn, param, buf, buflen);
2064 tcp_conn->hdr_size = sizeof(struct iscsi_hdr);
2065 if (conn->hdrdgst_en)
2066 tcp_conn->hdr_size += sizeof(__u32);
2067 break;
2068 case ISCSI_PARAM_DATADGST_EN:
2069 iscsi_set_param(cls_conn, param, buf, buflen);
2070 tcp_conn->sendpage = conn->datadgst_en ?
2071 sock_no_sendpage : tcp_conn->sock->ops->sendpage;
2072 break;
2073 case ISCSI_PARAM_MAX_R2T:
2074 sscanf(buf, "%d", &value);
2075 if (session->max_r2t == roundup_pow_of_two(value))
2076 break;
2077 iscsi_r2tpool_free(session);
2078 iscsi_set_param(cls_conn, param, buf, buflen);
2079 if (session->max_r2t & (session->max_r2t - 1))
2080 session->max_r2t = roundup_pow_of_two(session->max_r2t);
2081 if (iscsi_r2tpool_alloc(session))
2082 return -ENOMEM;
2083 break;
2084 default:
2085 return iscsi_set_param(cls_conn, param, buf, buflen);
2086 }
2087
2088 return 0;
2089 }
2090
2091 static int
2092 iscsi_tcp_conn_get_param(struct iscsi_cls_conn *cls_conn,
2093 enum iscsi_param param, char *buf)
2094 {
2095 struct iscsi_conn *conn = cls_conn->dd_data;
2096 int len;
2097
2098 switch(param) {
2099 case ISCSI_PARAM_CONN_PORT:
2100 spin_lock_bh(&conn->session->lock);
2101 len = sprintf(buf, "%hu\n", conn->portal_port);
2102 spin_unlock_bh(&conn->session->lock);
2103 break;
2104 case ISCSI_PARAM_CONN_ADDRESS:
2105 spin_lock_bh(&conn->session->lock);
2106 len = sprintf(buf, "%s\n", conn->portal_address);
2107 spin_unlock_bh(&conn->session->lock);
2108 break;
2109 default:
2110 return iscsi_conn_get_param(cls_conn, param, buf);
2111 }
2112
2113 return len;
2114 }
2115
2116 static int
2117 iscsi_tcp_host_get_param(struct Scsi_Host *shost, enum iscsi_host_param param,
2118 char *buf)
2119 {
2120 struct iscsi_session *session = iscsi_hostdata(shost->hostdata);
2121 int len;
2122
2123 switch (param) {
2124 case ISCSI_HOST_PARAM_IPADDRESS:
2125 spin_lock_bh(&session->lock);
2126 if (!session->leadconn)
2127 len = -ENODEV;
2128 else
2129 len = sprintf(buf, "%s\n",
2130 session->leadconn->local_address);
2131 spin_unlock_bh(&session->lock);
2132 break;
2133 default:
2134 return iscsi_host_get_param(shost, param, buf);
2135 }
2136 return len;
2137 }
2138
2139 static void
2140 iscsi_conn_get_stats(struct iscsi_cls_conn *cls_conn, struct iscsi_stats *stats)
2141 {
2142 struct iscsi_conn *conn = cls_conn->dd_data;
2143 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
2144
2145 stats->txdata_octets = conn->txdata_octets;
2146 stats->rxdata_octets = conn->rxdata_octets;
2147 stats->scsicmd_pdus = conn->scsicmd_pdus_cnt;
2148 stats->dataout_pdus = conn->dataout_pdus_cnt;
2149 stats->scsirsp_pdus = conn->scsirsp_pdus_cnt;
2150 stats->datain_pdus = conn->datain_pdus_cnt;
2151 stats->r2t_pdus = conn->r2t_pdus_cnt;
2152 stats->tmfcmd_pdus = conn->tmfcmd_pdus_cnt;
2153 stats->tmfrsp_pdus = conn->tmfrsp_pdus_cnt;
2154 stats->custom_length = 3;
2155 strcpy(stats->custom[0].desc, "tx_sendpage_failures");
2156 stats->custom[0].value = tcp_conn->sendpage_failures_cnt;
2157 strcpy(stats->custom[1].desc, "rx_discontiguous_hdr");
2158 stats->custom[1].value = tcp_conn->discontiguous_hdr_cnt;
2159 strcpy(stats->custom[2].desc, "eh_abort_cnt");
2160 stats->custom[2].value = conn->eh_abort_cnt;
2161 }
2162
2163 static struct iscsi_cls_session *
2164 iscsi_tcp_session_create(struct iscsi_transport *iscsit,
2165 struct scsi_transport_template *scsit,
2166 uint16_t cmds_max, uint16_t qdepth,
2167 uint32_t initial_cmdsn, uint32_t *hostno)
2168 {
2169 struct iscsi_cls_session *cls_session;
2170 struct iscsi_session *session;
2171 uint32_t hn;
2172 int cmd_i;
2173
2174 cls_session = iscsi_session_setup(iscsit, scsit, cmds_max, qdepth,
2175 sizeof(struct iscsi_tcp_cmd_task),
2176 sizeof(struct iscsi_tcp_mgmt_task),
2177 initial_cmdsn, &hn);
2178 if (!cls_session)
2179 return NULL;
2180 *hostno = hn;
2181
2182 session = class_to_transport_session(cls_session);
2183 for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
2184 struct iscsi_cmd_task *ctask = session->cmds[cmd_i];
2185 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
2186
2187 ctask->hdr = &tcp_ctask->hdr;
2188 }
2189
2190 for (cmd_i = 0; cmd_i < session->mgmtpool_max; cmd_i++) {
2191 struct iscsi_mgmt_task *mtask = session->mgmt_cmds[cmd_i];
2192 struct iscsi_tcp_mgmt_task *tcp_mtask = mtask->dd_data;
2193
2194 mtask->hdr = &tcp_mtask->hdr;
2195 }
2196
2197 if (iscsi_r2tpool_alloc(class_to_transport_session(cls_session)))
2198 goto r2tpool_alloc_fail;
2199
2200 return cls_session;
2201
2202 r2tpool_alloc_fail:
2203 iscsi_session_teardown(cls_session);
2204 return NULL;
2205 }
2206
2207 static void iscsi_tcp_session_destroy(struct iscsi_cls_session *cls_session)
2208 {
2209 iscsi_r2tpool_free(class_to_transport_session(cls_session));
2210 iscsi_session_teardown(cls_session);
2211 }
2212
2213 static int iscsi_tcp_slave_configure(struct scsi_device *sdev)
2214 {
2215 blk_queue_bounce_limit(sdev->request_queue, BLK_BOUNCE_ANY);
2216 blk_queue_dma_alignment(sdev->request_queue, 0);
2217 return 0;
2218 }
2219
2220 static struct scsi_host_template iscsi_sht = {
2221 .module = THIS_MODULE,
2222 .name = "iSCSI Initiator over TCP/IP",
2223 .queuecommand = iscsi_queuecommand,
2224 .change_queue_depth = iscsi_change_queue_depth,
2225 .can_queue = ISCSI_DEF_XMIT_CMDS_MAX - 1,
2226 .sg_tablesize = ISCSI_SG_TABLESIZE,
2227 .max_sectors = 0xFFFF,
2228 .cmd_per_lun = ISCSI_DEF_CMD_PER_LUN,
2229 .eh_abort_handler = iscsi_eh_abort,
2230 .eh_host_reset_handler = iscsi_eh_host_reset,
2231 .use_clustering = DISABLE_CLUSTERING,
2232 .slave_configure = iscsi_tcp_slave_configure,
2233 .proc_name = "iscsi_tcp",
2234 .this_id = -1,
2235 };
2236
2237 static struct iscsi_transport iscsi_tcp_transport = {
2238 .owner = THIS_MODULE,
2239 .name = "tcp",
2240 .caps = CAP_RECOVERY_L0 | CAP_MULTI_R2T | CAP_HDRDGST
2241 | CAP_DATADGST,
2242 .param_mask = ISCSI_MAX_RECV_DLENGTH |
2243 ISCSI_MAX_XMIT_DLENGTH |
2244 ISCSI_HDRDGST_EN |
2245 ISCSI_DATADGST_EN |
2246 ISCSI_INITIAL_R2T_EN |
2247 ISCSI_MAX_R2T |
2248 ISCSI_IMM_DATA_EN |
2249 ISCSI_FIRST_BURST |
2250 ISCSI_MAX_BURST |
2251 ISCSI_PDU_INORDER_EN |
2252 ISCSI_DATASEQ_INORDER_EN |
2253 ISCSI_ERL |
2254 ISCSI_CONN_PORT |
2255 ISCSI_CONN_ADDRESS |
2256 ISCSI_EXP_STATSN |
2257 ISCSI_PERSISTENT_PORT |
2258 ISCSI_PERSISTENT_ADDRESS |
2259 ISCSI_TARGET_NAME | ISCSI_TPGT |
2260 ISCSI_USERNAME | ISCSI_PASSWORD |
2261 ISCSI_USERNAME_IN | ISCSI_PASSWORD_IN,
2262 .host_param_mask = ISCSI_HOST_HWADDRESS | ISCSI_HOST_IPADDRESS |
2263 ISCSI_HOST_INITIATOR_NAME |
2264 ISCSI_HOST_NETDEV_NAME,
2265 .host_template = &iscsi_sht,
2266 .conndata_size = sizeof(struct iscsi_conn),
2267 .max_conn = 1,
2268 .max_cmd_len = ISCSI_TCP_MAX_CMD_LEN,
2269 /* session management */
2270 .create_session = iscsi_tcp_session_create,
2271 .destroy_session = iscsi_tcp_session_destroy,
2272 /* connection management */
2273 .create_conn = iscsi_tcp_conn_create,
2274 .bind_conn = iscsi_tcp_conn_bind,
2275 .destroy_conn = iscsi_tcp_conn_destroy,
2276 .set_param = iscsi_conn_set_param,
2277 .get_conn_param = iscsi_tcp_conn_get_param,
2278 .get_session_param = iscsi_session_get_param,
2279 .start_conn = iscsi_conn_start,
2280 .stop_conn = iscsi_tcp_conn_stop,
2281 /* iscsi host params */
2282 .get_host_param = iscsi_tcp_host_get_param,
2283 .set_host_param = iscsi_host_set_param,
2284 /* IO */
2285 .send_pdu = iscsi_conn_send_pdu,
2286 .get_stats = iscsi_conn_get_stats,
2287 .init_cmd_task = iscsi_tcp_cmd_init,
2288 .init_mgmt_task = iscsi_tcp_mgmt_init,
2289 .xmit_cmd_task = iscsi_tcp_ctask_xmit,
2290 .xmit_mgmt_task = iscsi_tcp_mtask_xmit,
2291 .cleanup_cmd_task = iscsi_tcp_cleanup_ctask,
2292 /* recovery */
2293 .session_recovery_timedout = iscsi_session_recovery_timedout,
2294 };
2295
2296 static int __init
2297 iscsi_tcp_init(void)
2298 {
2299 if (iscsi_max_lun < 1) {
2300 printk(KERN_ERR "iscsi_tcp: Invalid max_lun value of %u\n",
2301 iscsi_max_lun);
2302 return -EINVAL;
2303 }
2304 iscsi_tcp_transport.max_lun = iscsi_max_lun;
2305
2306 if (!iscsi_register_transport(&iscsi_tcp_transport))
2307 return -ENODEV;
2308
2309 return 0;
2310 }
2311
2312 static void __exit
2313 iscsi_tcp_exit(void)
2314 {
2315 iscsi_unregister_transport(&iscsi_tcp_transport);
2316 }
2317
2318 module_init(iscsi_tcp_init);
2319 module_exit(iscsi_tcp_exit);
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