097a136398cbd771d07cd98df22f813c63c93c52
[linux-2.6.git] / drivers / scsi / iscsi_tcp.c
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         memcpy(&temp, sg, sizeof(struct scatterlist));
678         temp.offset = offset;
679         temp.length = length;
680         crypto_hash_update(desc, &temp, length);
681 }
682
683 static void
684 iscsi_recv_digest_update(struct iscsi_tcp_conn *tcp_conn, char* buf, int len)
685 {
686         struct scatterlist tmp;
687
688         sg_init_one(&tmp, buf, len);
689         crypto_hash_update(&tcp_conn->rx_hash, &tmp, len);
690 }
691
692 static int iscsi_scsi_data_in(struct iscsi_conn *conn)
693 {
694         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
695         struct iscsi_cmd_task *ctask = tcp_conn->in.ctask;
696         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
697         struct scsi_cmnd *sc = ctask->sc;
698         struct scatterlist *sg;
699         int i, offset, rc = 0;
700
701         BUG_ON((void*)ctask != sc->SCp.ptr);
702
703         offset = tcp_ctask->data_offset;
704         sg = scsi_sglist(sc);
705
706         if (tcp_ctask->data_offset)
707                 for (i = 0; i < tcp_ctask->sg_count; i++)
708                         offset -= sg[i].length;
709         /* we've passed through partial sg*/
710         if (offset < 0)
711                 offset = 0;
712
713         for (i = tcp_ctask->sg_count; i < scsi_sg_count(sc); i++) {
714                 char *dest;
715
716                 dest = kmap_atomic(sg_page(&sg[i]), KM_SOFTIRQ0);
717                 rc = iscsi_ctask_copy(tcp_conn, ctask, dest + sg[i].offset,
718                                       sg[i].length, offset);
719                 kunmap_atomic(dest, KM_SOFTIRQ0);
720                 if (rc == -EAGAIN)
721                         /* continue with the next SKB/PDU */
722                         return rc;
723                 if (!rc) {
724                         if (conn->datadgst_en) {
725                                 if (!offset)
726                                         crypto_hash_update(
727                                                         &tcp_conn->rx_hash,
728                                                         &sg[i], sg[i].length);
729                                 else
730                                         partial_sg_digest_update(
731                                                         &tcp_conn->rx_hash,
732                                                         &sg[i],
733                                                         sg[i].offset + offset,
734                                                         sg[i].length - offset);
735                         }
736                         offset = 0;
737                         tcp_ctask->sg_count++;
738                 }
739
740                 if (!ctask->data_count) {
741                         if (rc && conn->datadgst_en)
742                                 /*
743                                  * data-in is complete, but buffer not...
744                                  */
745                                 partial_sg_digest_update(&tcp_conn->rx_hash,
746                                                          &sg[i],
747                                                          sg[i].offset,
748                                                          sg[i].length-rc);
749                         rc = 0;
750                         break;
751                 }
752
753                 if (!tcp_conn->in.copy)
754                         return -EAGAIN;
755         }
756         BUG_ON(ctask->data_count);
757
758         /* check for non-exceptional status */
759         if (tcp_conn->in.hdr->flags & ISCSI_FLAG_DATA_STATUS) {
760                 debug_scsi("done [sc %lx res %d itt 0x%x flags 0x%x]\n",
761                            (long)sc, sc->result, ctask->itt,
762                            tcp_conn->in.hdr->flags);
763                 spin_lock(&conn->session->lock);
764                 __iscsi_complete_pdu(conn, tcp_conn->in.hdr, NULL, 0);
765                 spin_unlock(&conn->session->lock);
766         }
767
768         return rc;
769 }
770
771 static int
772 iscsi_data_recv(struct iscsi_conn *conn)
773 {
774         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
775         int rc = 0, opcode;
776
777         opcode = tcp_conn->in.hdr->opcode & ISCSI_OPCODE_MASK;
778         switch (opcode) {
779         case ISCSI_OP_SCSI_DATA_IN:
780                 rc = iscsi_scsi_data_in(conn);
781                 break;
782         case ISCSI_OP_SCSI_CMD_RSP:
783         case ISCSI_OP_TEXT_RSP:
784         case ISCSI_OP_LOGIN_RSP:
785         case ISCSI_OP_ASYNC_EVENT:
786         case ISCSI_OP_REJECT:
787                 /*
788                  * Collect data segment to the connection's data
789                  * placeholder
790                  */
791                 if (iscsi_tcp_copy(conn, tcp_conn->in.datalen)) {
792                         rc = -EAGAIN;
793                         goto exit;
794                 }
795
796                 rc = iscsi_complete_pdu(conn, tcp_conn->in.hdr, conn->data,
797                                         tcp_conn->in.datalen);
798                 if (!rc && conn->datadgst_en && opcode != ISCSI_OP_LOGIN_RSP)
799                         iscsi_recv_digest_update(tcp_conn, conn->data,
800                                                 tcp_conn->in.datalen);
801                 break;
802         default:
803                 BUG_ON(1);
804         }
805 exit:
806         return rc;
807 }
808
809 /**
810  * iscsi_tcp_data_recv - TCP receive in sendfile fashion
811  * @rd_desc: read descriptor
812  * @skb: socket buffer
813  * @offset: offset in skb
814  * @len: skb->len - offset
815  **/
816 static int
817 iscsi_tcp_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb,
818                 unsigned int offset, size_t len)
819 {
820         int rc;
821         struct iscsi_conn *conn = rd_desc->arg.data;
822         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
823         int processed;
824         char pad[ISCSI_PAD_LEN];
825         struct scatterlist sg;
826
827         /*
828          * Save current SKB and its offset in the corresponding
829          * connection context.
830          */
831         tcp_conn->in.copy = skb->len - offset;
832         tcp_conn->in.offset = offset;
833         tcp_conn->in.skb = skb;
834         tcp_conn->in.len = tcp_conn->in.copy;
835         BUG_ON(tcp_conn->in.copy <= 0);
836         debug_tcp("in %d bytes\n", tcp_conn->in.copy);
837
838 more:
839         tcp_conn->in.copied = 0;
840         rc = 0;
841
842         if (unlikely(conn->suspend_rx)) {
843                 debug_tcp("conn %d Rx suspended!\n", conn->id);
844                 return 0;
845         }
846
847         if (tcp_conn->in_progress == IN_PROGRESS_WAIT_HEADER ||
848             tcp_conn->in_progress == IN_PROGRESS_HEADER_GATHER) {
849                 rc = iscsi_hdr_extract(tcp_conn);
850                 if (rc) {
851                        if (rc == -EAGAIN)
852                                 goto nomore;
853                        else {
854                                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
855                                 return 0;
856                        }
857                 }
858
859                 /*
860                  * Verify and process incoming PDU header.
861                  */
862                 rc = iscsi_tcp_hdr_recv(conn);
863                 if (!rc && tcp_conn->in.datalen) {
864                         if (conn->datadgst_en)
865                                 crypto_hash_init(&tcp_conn->rx_hash);
866                         tcp_conn->in_progress = IN_PROGRESS_DATA_RECV;
867                 } else if (rc) {
868                         iscsi_conn_failure(conn, rc);
869                         return 0;
870                 }
871         }
872
873         if (tcp_conn->in_progress == IN_PROGRESS_DDIGEST_RECV &&
874             tcp_conn->in.copy) {
875                 uint32_t recv_digest;
876
877                 debug_tcp("extra data_recv offset %d copy %d\n",
878                           tcp_conn->in.offset, tcp_conn->in.copy);
879
880                 if (!tcp_conn->data_copied) {
881                         if (tcp_conn->in.padding) {
882                                 debug_tcp("padding -> %d\n",
883                                           tcp_conn->in.padding);
884                                 memset(pad, 0, tcp_conn->in.padding);
885                                 sg_init_one(&sg, pad, tcp_conn->in.padding);
886                                 crypto_hash_update(&tcp_conn->rx_hash,
887                                                    &sg, sg.length);
888                         }
889                         crypto_hash_final(&tcp_conn->rx_hash,
890                                           (u8 *) &tcp_conn->in.datadgst);
891                         debug_tcp("rx digest 0x%x\n", tcp_conn->in.datadgst);
892                 }
893
894                 rc = iscsi_tcp_copy(conn, sizeof(uint32_t));
895                 if (rc) {
896                         if (rc == -EAGAIN)
897                                 goto again;
898                         iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
899                         return 0;
900                 }
901
902                 memcpy(&recv_digest, conn->data, sizeof(uint32_t));
903                 if (recv_digest != tcp_conn->in.datadgst) {
904                         debug_tcp("iscsi_tcp: data digest error!"
905                                   "0x%x != 0x%x\n", recv_digest,
906                                   tcp_conn->in.datadgst);
907                         iscsi_conn_failure(conn, ISCSI_ERR_DATA_DGST);
908                         return 0;
909                 } else {
910                         debug_tcp("iscsi_tcp: data digest match!"
911                                   "0x%x == 0x%x\n", recv_digest,
912                                   tcp_conn->in.datadgst);
913                         tcp_conn->in_progress = IN_PROGRESS_WAIT_HEADER;
914                 }
915         }
916
917         if (tcp_conn->in_progress == IN_PROGRESS_DATA_RECV &&
918             tcp_conn->in.copy) {
919                 debug_tcp("data_recv offset %d copy %d\n",
920                        tcp_conn->in.offset, tcp_conn->in.copy);
921
922                 rc = iscsi_data_recv(conn);
923                 if (rc) {
924                         if (rc == -EAGAIN)
925                                 goto again;
926                         iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
927                         return 0;
928                 }
929
930                 if (tcp_conn->in.padding)
931                         tcp_conn->in_progress = IN_PROGRESS_PAD_RECV;
932                 else if (conn->datadgst_en)
933                         tcp_conn->in_progress = IN_PROGRESS_DDIGEST_RECV;
934                 else
935                         tcp_conn->in_progress = IN_PROGRESS_WAIT_HEADER;
936                 tcp_conn->data_copied = 0;
937         }
938
939         if (tcp_conn->in_progress == IN_PROGRESS_PAD_RECV &&
940             tcp_conn->in.copy) {
941                 int copylen = min(tcp_conn->in.padding - tcp_conn->data_copied,
942                                   tcp_conn->in.copy);
943
944                 tcp_conn->in.copy -= copylen;
945                 tcp_conn->in.offset += copylen;
946                 tcp_conn->data_copied += copylen;
947
948                 if (tcp_conn->data_copied != tcp_conn->in.padding)
949                         tcp_conn->in_progress = IN_PROGRESS_PAD_RECV;
950                 else if (conn->datadgst_en)
951                         tcp_conn->in_progress = IN_PROGRESS_DDIGEST_RECV;
952                 else
953                         tcp_conn->in_progress = IN_PROGRESS_WAIT_HEADER;
954                 tcp_conn->data_copied = 0;
955         }
956
957         debug_tcp("f, processed %d from out of %d padding %d\n",
958                tcp_conn->in.offset - offset, (int)len, tcp_conn->in.padding);
959         BUG_ON(tcp_conn->in.offset - offset > len);
960
961         if (tcp_conn->in.offset - offset != len) {
962                 debug_tcp("continue to process %d bytes\n",
963                        (int)len - (tcp_conn->in.offset - offset));
964                 goto more;
965         }
966
967 nomore:
968         processed = tcp_conn->in.offset - offset;
969         BUG_ON(processed == 0);
970         return processed;
971
972 again:
973         processed = tcp_conn->in.offset - offset;
974         debug_tcp("c, processed %d from out of %d rd_desc_cnt %d\n",
975                   processed, (int)len, (int)rd_desc->count);
976         BUG_ON(processed == 0);
977         BUG_ON(processed > len);
978
979         conn->rxdata_octets += processed;
980         return processed;
981 }
982
983 static void
984 iscsi_tcp_data_ready(struct sock *sk, int flag)
985 {
986         struct iscsi_conn *conn = sk->sk_user_data;
987         read_descriptor_t rd_desc;
988
989         read_lock(&sk->sk_callback_lock);
990
991         /*
992          * Use rd_desc to pass 'conn' to iscsi_tcp_data_recv.
993          * We set count to 1 because we want the network layer to
994          * hand us all the skbs that are available. iscsi_tcp_data_recv
995          * handled pdus that cross buffers or pdus that still need data.
996          */
997         rd_desc.arg.data = conn;
998         rd_desc.count = 1;
999         tcp_read_sock(sk, &rd_desc, iscsi_tcp_data_recv);
1000
1001         read_unlock(&sk->sk_callback_lock);
1002 }
1003
1004 static void
1005 iscsi_tcp_state_change(struct sock *sk)
1006 {
1007         struct iscsi_tcp_conn *tcp_conn;
1008         struct iscsi_conn *conn;
1009         struct iscsi_session *session;
1010         void (*old_state_change)(struct sock *);
1011
1012         read_lock(&sk->sk_callback_lock);
1013
1014         conn = (struct iscsi_conn*)sk->sk_user_data;
1015         session = conn->session;
1016
1017         if ((sk->sk_state == TCP_CLOSE_WAIT ||
1018              sk->sk_state == TCP_CLOSE) &&
1019             !atomic_read(&sk->sk_rmem_alloc)) {
1020                 debug_tcp("iscsi_tcp_state_change: TCP_CLOSE|TCP_CLOSE_WAIT\n");
1021                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1022         }
1023
1024         tcp_conn = conn->dd_data;
1025         old_state_change = tcp_conn->old_state_change;
1026
1027         read_unlock(&sk->sk_callback_lock);
1028
1029         old_state_change(sk);
1030 }
1031
1032 /**
1033  * iscsi_write_space - Called when more output buffer space is available
1034  * @sk: socket space is available for
1035  **/
1036 static void
1037 iscsi_write_space(struct sock *sk)
1038 {
1039         struct iscsi_conn *conn = (struct iscsi_conn*)sk->sk_user_data;
1040         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1041
1042         tcp_conn->old_write_space(sk);
1043         debug_tcp("iscsi_write_space: cid %d\n", conn->id);
1044         scsi_queue_work(conn->session->host, &conn->xmitwork);
1045 }
1046
1047 static void
1048 iscsi_conn_set_callbacks(struct iscsi_conn *conn)
1049 {
1050         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1051         struct sock *sk = tcp_conn->sock->sk;
1052
1053         /* assign new callbacks */
1054         write_lock_bh(&sk->sk_callback_lock);
1055         sk->sk_user_data = conn;
1056         tcp_conn->old_data_ready = sk->sk_data_ready;
1057         tcp_conn->old_state_change = sk->sk_state_change;
1058         tcp_conn->old_write_space = sk->sk_write_space;
1059         sk->sk_data_ready = iscsi_tcp_data_ready;
1060         sk->sk_state_change = iscsi_tcp_state_change;
1061         sk->sk_write_space = iscsi_write_space;
1062         write_unlock_bh(&sk->sk_callback_lock);
1063 }
1064
1065 static void
1066 iscsi_conn_restore_callbacks(struct iscsi_tcp_conn *tcp_conn)
1067 {
1068         struct sock *sk = tcp_conn->sock->sk;
1069
1070         /* restore socket callbacks, see also: iscsi_conn_set_callbacks() */
1071         write_lock_bh(&sk->sk_callback_lock);
1072         sk->sk_user_data    = NULL;
1073         sk->sk_data_ready   = tcp_conn->old_data_ready;
1074         sk->sk_state_change = tcp_conn->old_state_change;
1075         sk->sk_write_space  = tcp_conn->old_write_space;
1076         sk->sk_no_check  = 0;
1077         write_unlock_bh(&sk->sk_callback_lock);
1078 }
1079
1080 /**
1081  * iscsi_send - generic send routine
1082  * @sk: kernel's socket
1083  * @buf: buffer to write from
1084  * @size: actual size to write
1085  * @flags: socket's flags
1086  */
1087 static inline int
1088 iscsi_send(struct iscsi_conn *conn, struct iscsi_buf *buf, int size, int flags)
1089 {
1090         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1091         struct socket *sk = tcp_conn->sock;
1092         int offset = buf->sg.offset + buf->sent, res;
1093
1094         /*
1095          * if we got use_sg=0 or are sending something we kmallocd
1096          * then we did not have to do kmap (kmap returns page_address)
1097          *
1098          * if we got use_sg > 0, but had to drop down, we do not
1099          * set clustering so this should only happen for that
1100          * slab case.
1101          */
1102         if (buf->use_sendmsg)
1103                 res = sock_no_sendpage(sk, sg_page(&buf->sg), offset, size, flags);
1104         else
1105                 res = tcp_conn->sendpage(sk, sg_page(&buf->sg), offset, size, flags);
1106
1107         if (res >= 0) {
1108                 conn->txdata_octets += res;
1109                 buf->sent += res;
1110                 return res;
1111         }
1112
1113         tcp_conn->sendpage_failures_cnt++;
1114         if (res == -EAGAIN)
1115                 res = -ENOBUFS;
1116         else
1117                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1118         return res;
1119 }
1120
1121 /**
1122  * iscsi_sendhdr - send PDU Header via tcp_sendpage()
1123  * @conn: iscsi connection
1124  * @buf: buffer to write from
1125  * @datalen: lenght of data to be sent after the header
1126  *
1127  * Notes:
1128  *      (Tx, Fast Path)
1129  **/
1130 static inline int
1131 iscsi_sendhdr(struct iscsi_conn *conn, struct iscsi_buf *buf, int datalen)
1132 {
1133         int flags = 0; /* MSG_DONTWAIT; */
1134         int res, size;
1135
1136         size = buf->sg.length - buf->sent;
1137         BUG_ON(buf->sent + size > buf->sg.length);
1138         if (buf->sent + size != buf->sg.length || datalen)
1139                 flags |= MSG_MORE;
1140
1141         res = iscsi_send(conn, buf, size, flags);
1142         debug_tcp("sendhdr %d bytes, sent %d res %d\n", size, buf->sent, res);
1143         if (res >= 0) {
1144                 if (size != res)
1145                         return -EAGAIN;
1146                 return 0;
1147         }
1148
1149         return res;
1150 }
1151
1152 /**
1153  * iscsi_sendpage - send one page of iSCSI Data-Out.
1154  * @conn: iscsi connection
1155  * @buf: buffer to write from
1156  * @count: remaining data
1157  * @sent: number of bytes sent
1158  *
1159  * Notes:
1160  *      (Tx, Fast Path)
1161  **/
1162 static inline int
1163 iscsi_sendpage(struct iscsi_conn *conn, struct iscsi_buf *buf,
1164                int *count, int *sent)
1165 {
1166         int flags = 0; /* MSG_DONTWAIT; */
1167         int res, size;
1168
1169         size = buf->sg.length - buf->sent;
1170         BUG_ON(buf->sent + size > buf->sg.length);
1171         if (size > *count)
1172                 size = *count;
1173         if (buf->sent + size != buf->sg.length || *count != size)
1174                 flags |= MSG_MORE;
1175
1176         res = iscsi_send(conn, buf, size, flags);
1177         debug_tcp("sendpage: %d bytes, sent %d left %d sent %d res %d\n",
1178                   size, buf->sent, *count, *sent, res);
1179         if (res >= 0) {
1180                 *count -= res;
1181                 *sent += res;
1182                 if (size != res)
1183                         return -EAGAIN;
1184                 return 0;
1185         }
1186
1187         return res;
1188 }
1189
1190 static inline void
1191 iscsi_data_digest_init(struct iscsi_tcp_conn *tcp_conn,
1192                       struct iscsi_tcp_cmd_task *tcp_ctask)
1193 {
1194         crypto_hash_init(&tcp_conn->tx_hash);
1195         tcp_ctask->digest_count = 4;
1196 }
1197
1198 /**
1199  * iscsi_solicit_data_cont - initialize next Data-Out
1200  * @conn: iscsi connection
1201  * @ctask: scsi command task
1202  * @r2t: R2T info
1203  * @left: bytes left to transfer
1204  *
1205  * Notes:
1206  *      Initialize next Data-Out within this R2T sequence and continue
1207  *      to process next Scatter-Gather element(if any) of this SCSI command.
1208  *
1209  *      Called under connection lock.
1210  **/
1211 static void
1212 iscsi_solicit_data_cont(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
1213                         struct iscsi_r2t_info *r2t, int left)
1214 {
1215         struct iscsi_data *hdr;
1216         int new_offset;
1217
1218         hdr = &r2t->dtask.hdr;
1219         memset(hdr, 0, sizeof(struct iscsi_data));
1220         hdr->ttt = r2t->ttt;
1221         hdr->datasn = cpu_to_be32(r2t->solicit_datasn);
1222         r2t->solicit_datasn++;
1223         hdr->opcode = ISCSI_OP_SCSI_DATA_OUT;
1224         memcpy(hdr->lun, ctask->hdr->lun, sizeof(hdr->lun));
1225         hdr->itt = ctask->hdr->itt;
1226         hdr->exp_statsn = r2t->exp_statsn;
1227         new_offset = r2t->data_offset + r2t->sent;
1228         hdr->offset = cpu_to_be32(new_offset);
1229         if (left > conn->max_xmit_dlength) {
1230                 hton24(hdr->dlength, conn->max_xmit_dlength);
1231                 r2t->data_count = conn->max_xmit_dlength;
1232         } else {
1233                 hton24(hdr->dlength, left);
1234                 r2t->data_count = left;
1235                 hdr->flags = ISCSI_FLAG_CMD_FINAL;
1236         }
1237         conn->dataout_pdus_cnt++;
1238
1239         iscsi_buf_init_iov(&r2t->headbuf, (char*)hdr,
1240                            sizeof(struct iscsi_hdr));
1241
1242         if (iscsi_buf_left(&r2t->sendbuf))
1243                 return;
1244
1245         iscsi_buf_init_sg(&r2t->sendbuf, r2t->sg);
1246         r2t->sg += 1;
1247 }
1248
1249 static void iscsi_set_padding(struct iscsi_tcp_cmd_task *tcp_ctask,
1250                               unsigned long len)
1251 {
1252         tcp_ctask->pad_count = len & (ISCSI_PAD_LEN - 1);
1253         if (!tcp_ctask->pad_count)
1254                 return;
1255
1256         tcp_ctask->pad_count = ISCSI_PAD_LEN - tcp_ctask->pad_count;
1257         debug_scsi("write padding %d bytes\n", tcp_ctask->pad_count);
1258         tcp_ctask->xmstate |= XMSTATE_W_PAD;
1259 }
1260
1261 /**
1262  * iscsi_tcp_cmd_init - Initialize iSCSI SCSI_READ or SCSI_WRITE commands
1263  * @conn: iscsi connection
1264  * @ctask: scsi command task
1265  * @sc: scsi command
1266  **/
1267 static void
1268 iscsi_tcp_cmd_init(struct iscsi_cmd_task *ctask)
1269 {
1270         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1271
1272         BUG_ON(__kfifo_len(tcp_ctask->r2tqueue));
1273         tcp_ctask->xmstate = XMSTATE_CMD_HDR_INIT;
1274 }
1275
1276 /**
1277  * iscsi_tcp_mtask_xmit - xmit management(immediate) task
1278  * @conn: iscsi connection
1279  * @mtask: task management task
1280  *
1281  * Notes:
1282  *      The function can return -EAGAIN in which case caller must
1283  *      call it again later, or recover. '0' return code means successful
1284  *      xmit.
1285  *
1286  *      Management xmit state machine consists of these states:
1287  *              XMSTATE_IMM_HDR_INIT    - calculate digest of PDU Header
1288  *              XMSTATE_IMM_HDR         - PDU Header xmit in progress
1289  *              XMSTATE_IMM_DATA        - PDU Data xmit in progress
1290  *              XMSTATE_IDLE            - management PDU is done
1291  **/
1292 static int
1293 iscsi_tcp_mtask_xmit(struct iscsi_conn *conn, struct iscsi_mgmt_task *mtask)
1294 {
1295         struct iscsi_tcp_mgmt_task *tcp_mtask = mtask->dd_data;
1296         int rc;
1297
1298         debug_scsi("mtask deq [cid %d state %x itt 0x%x]\n",
1299                 conn->id, tcp_mtask->xmstate, mtask->itt);
1300
1301         if (tcp_mtask->xmstate & XMSTATE_IMM_HDR_INIT) {
1302                 iscsi_buf_init_iov(&tcp_mtask->headbuf, (char*)mtask->hdr,
1303                                    sizeof(struct iscsi_hdr));
1304
1305                 if (mtask->data_count) {
1306                         tcp_mtask->xmstate |= XMSTATE_IMM_DATA;
1307                         iscsi_buf_init_iov(&tcp_mtask->sendbuf,
1308                                            (char*)mtask->data,
1309                                            mtask->data_count);
1310                 }
1311
1312                 if (conn->c_stage != ISCSI_CONN_INITIAL_STAGE &&
1313                     conn->stop_stage != STOP_CONN_RECOVER &&
1314                     conn->hdrdgst_en)
1315                         iscsi_hdr_digest(conn, &tcp_mtask->headbuf,
1316                                         (u8*)tcp_mtask->hdrext);
1317
1318                 tcp_mtask->sent = 0;
1319                 tcp_mtask->xmstate &= ~XMSTATE_IMM_HDR_INIT;
1320                 tcp_mtask->xmstate |= XMSTATE_IMM_HDR;
1321         }
1322
1323         if (tcp_mtask->xmstate & XMSTATE_IMM_HDR) {
1324                 rc = iscsi_sendhdr(conn, &tcp_mtask->headbuf,
1325                                    mtask->data_count);
1326                 if (rc)
1327                         return rc;
1328                 tcp_mtask->xmstate &= ~XMSTATE_IMM_HDR;
1329         }
1330
1331         if (tcp_mtask->xmstate & XMSTATE_IMM_DATA) {
1332                 BUG_ON(!mtask->data_count);
1333                 tcp_mtask->xmstate &= ~XMSTATE_IMM_DATA;
1334                 /* FIXME: implement.
1335                  * Virtual buffer could be spreaded across multiple pages...
1336                  */
1337                 do {
1338                         int rc;
1339
1340                         rc = iscsi_sendpage(conn, &tcp_mtask->sendbuf,
1341                                         &mtask->data_count, &tcp_mtask->sent);
1342                         if (rc) {
1343                                 tcp_mtask->xmstate |= XMSTATE_IMM_DATA;
1344                                 return rc;
1345                         }
1346                 } while (mtask->data_count);
1347         }
1348
1349         BUG_ON(tcp_mtask->xmstate != XMSTATE_IDLE);
1350         if (mtask->hdr->itt == RESERVED_ITT) {
1351                 struct iscsi_session *session = conn->session;
1352
1353                 spin_lock_bh(&session->lock);
1354                 list_del(&conn->mtask->running);
1355                 __kfifo_put(session->mgmtpool.queue, (void*)&conn->mtask,
1356                             sizeof(void*));
1357                 spin_unlock_bh(&session->lock);
1358         }
1359         return 0;
1360 }
1361
1362 static int
1363 iscsi_send_cmd_hdr(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1364 {
1365         struct scsi_cmnd *sc = ctask->sc;
1366         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1367         int rc = 0;
1368
1369         if (tcp_ctask->xmstate & XMSTATE_CMD_HDR_INIT) {
1370                 tcp_ctask->sent = 0;
1371                 tcp_ctask->sg_count = 0;
1372                 tcp_ctask->exp_datasn = 0;
1373
1374                 if (sc->sc_data_direction == DMA_TO_DEVICE) {
1375                         struct scatterlist *sg = scsi_sglist(sc);
1376
1377                         iscsi_buf_init_sg(&tcp_ctask->sendbuf, sg);
1378                         tcp_ctask->sg = sg + 1;
1379                         tcp_ctask->bad_sg = sg + scsi_sg_count(sc);
1380
1381                         debug_scsi("cmd [itt 0x%x total %d imm_data %d "
1382                                    "unsol count %d, unsol offset %d]\n",
1383                                    ctask->itt, scsi_bufflen(sc),
1384                                    ctask->imm_count, ctask->unsol_count,
1385                                    ctask->unsol_offset);
1386                 }
1387
1388                 iscsi_buf_init_iov(&tcp_ctask->headbuf, (char*)ctask->hdr,
1389                                   sizeof(struct iscsi_hdr));
1390
1391                 if (conn->hdrdgst_en)
1392                         iscsi_hdr_digest(conn, &tcp_ctask->headbuf,
1393                                          (u8*)tcp_ctask->hdrext);
1394                 tcp_ctask->xmstate &= ~XMSTATE_CMD_HDR_INIT;
1395                 tcp_ctask->xmstate |= XMSTATE_CMD_HDR_XMIT;
1396         }
1397
1398         if (tcp_ctask->xmstate & XMSTATE_CMD_HDR_XMIT) {
1399                 rc = iscsi_sendhdr(conn, &tcp_ctask->headbuf, ctask->imm_count);
1400                 if (rc)
1401                         return rc;
1402                 tcp_ctask->xmstate &= ~XMSTATE_CMD_HDR_XMIT;
1403
1404                 if (sc->sc_data_direction != DMA_TO_DEVICE)
1405                         return 0;
1406
1407                 if (ctask->imm_count) {
1408                         tcp_ctask->xmstate |= XMSTATE_IMM_DATA;
1409                         iscsi_set_padding(tcp_ctask, ctask->imm_count);
1410
1411                         if (ctask->conn->datadgst_en) {
1412                                 iscsi_data_digest_init(ctask->conn->dd_data,
1413                                                        tcp_ctask);
1414                                 tcp_ctask->immdigest = 0;
1415                         }
1416                 }
1417
1418                 if (ctask->unsol_count)
1419                         tcp_ctask->xmstate |=
1420                                         XMSTATE_UNS_HDR | XMSTATE_UNS_INIT;
1421         }
1422         return rc;
1423 }
1424
1425 static int
1426 iscsi_send_padding(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1427 {
1428         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1429         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1430         int sent = 0, rc;
1431
1432         if (tcp_ctask->xmstate & XMSTATE_W_PAD) {
1433                 iscsi_buf_init_iov(&tcp_ctask->sendbuf, (char*)&tcp_ctask->pad,
1434                                    tcp_ctask->pad_count);
1435                 if (conn->datadgst_en)
1436                         crypto_hash_update(&tcp_conn->tx_hash,
1437                                            &tcp_ctask->sendbuf.sg,
1438                                            tcp_ctask->sendbuf.sg.length);
1439         } else if (!(tcp_ctask->xmstate & XMSTATE_W_RESEND_PAD))
1440                 return 0;
1441
1442         tcp_ctask->xmstate &= ~XMSTATE_W_PAD;
1443         tcp_ctask->xmstate &= ~XMSTATE_W_RESEND_PAD;
1444         debug_scsi("sending %d pad bytes for itt 0x%x\n",
1445                    tcp_ctask->pad_count, ctask->itt);
1446         rc = iscsi_sendpage(conn, &tcp_ctask->sendbuf, &tcp_ctask->pad_count,
1447                            &sent);
1448         if (rc) {
1449                 debug_scsi("padding send failed %d\n", rc);
1450                 tcp_ctask->xmstate |= XMSTATE_W_RESEND_PAD;
1451         }
1452         return rc;
1453 }
1454
1455 static int
1456 iscsi_send_digest(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
1457                         struct iscsi_buf *buf, uint32_t *digest)
1458 {
1459         struct iscsi_tcp_cmd_task *tcp_ctask;
1460         struct iscsi_tcp_conn *tcp_conn;
1461         int rc, sent = 0;
1462
1463         if (!conn->datadgst_en)
1464                 return 0;
1465
1466         tcp_ctask = ctask->dd_data;
1467         tcp_conn = conn->dd_data;
1468
1469         if (!(tcp_ctask->xmstate & XMSTATE_W_RESEND_DATA_DIGEST)) {
1470                 crypto_hash_final(&tcp_conn->tx_hash, (u8*)digest);
1471                 iscsi_buf_init_iov(buf, (char*)digest, 4);
1472         }
1473         tcp_ctask->xmstate &= ~XMSTATE_W_RESEND_DATA_DIGEST;
1474
1475         rc = iscsi_sendpage(conn, buf, &tcp_ctask->digest_count, &sent);
1476         if (!rc)
1477                 debug_scsi("sent digest 0x%x for itt 0x%x\n", *digest,
1478                           ctask->itt);
1479         else {
1480                 debug_scsi("sending digest 0x%x failed for itt 0x%x!\n",
1481                           *digest, ctask->itt);
1482                 tcp_ctask->xmstate |= XMSTATE_W_RESEND_DATA_DIGEST;
1483         }
1484         return rc;
1485 }
1486
1487 static int
1488 iscsi_send_data(struct iscsi_cmd_task *ctask, struct iscsi_buf *sendbuf,
1489                 struct scatterlist **sg, int *sent, int *count,
1490                 struct iscsi_buf *digestbuf, uint32_t *digest)
1491 {
1492         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1493         struct iscsi_conn *conn = ctask->conn;
1494         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1495         int rc, buf_sent, offset;
1496
1497         while (*count) {
1498                 buf_sent = 0;
1499                 offset = sendbuf->sent;
1500
1501                 rc = iscsi_sendpage(conn, sendbuf, count, &buf_sent);
1502                 *sent = *sent + buf_sent;
1503                 if (buf_sent && conn->datadgst_en)
1504                         partial_sg_digest_update(&tcp_conn->tx_hash,
1505                                 &sendbuf->sg, sendbuf->sg.offset + offset,
1506                                 buf_sent);
1507                 if (!iscsi_buf_left(sendbuf) && *sg != tcp_ctask->bad_sg) {
1508                         iscsi_buf_init_sg(sendbuf, *sg);
1509                         *sg = *sg + 1;
1510                 }
1511
1512                 if (rc)
1513                         return rc;
1514         }
1515
1516         rc = iscsi_send_padding(conn, ctask);
1517         if (rc)
1518                 return rc;
1519
1520         return iscsi_send_digest(conn, ctask, digestbuf, digest);
1521 }
1522
1523 static int
1524 iscsi_send_unsol_hdr(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1525 {
1526         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1527         struct iscsi_data_task *dtask;
1528         int rc;
1529
1530         tcp_ctask->xmstate |= XMSTATE_UNS_DATA;
1531         if (tcp_ctask->xmstate & XMSTATE_UNS_INIT) {
1532                 dtask = &tcp_ctask->unsol_dtask;
1533
1534                 iscsi_prep_unsolicit_data_pdu(ctask, &dtask->hdr);
1535                 iscsi_buf_init_iov(&tcp_ctask->headbuf, (char*)&dtask->hdr,
1536                                    sizeof(struct iscsi_hdr));
1537                 if (conn->hdrdgst_en)
1538                         iscsi_hdr_digest(conn, &tcp_ctask->headbuf,
1539                                         (u8*)dtask->hdrext);
1540
1541                 tcp_ctask->xmstate &= ~XMSTATE_UNS_INIT;
1542                 iscsi_set_padding(tcp_ctask, ctask->data_count);
1543         }
1544
1545         rc = iscsi_sendhdr(conn, &tcp_ctask->headbuf, ctask->data_count);
1546         if (rc) {
1547                 tcp_ctask->xmstate &= ~XMSTATE_UNS_DATA;
1548                 tcp_ctask->xmstate |= XMSTATE_UNS_HDR;
1549                 return rc;
1550         }
1551
1552         if (conn->datadgst_en) {
1553                 dtask = &tcp_ctask->unsol_dtask;
1554                 iscsi_data_digest_init(ctask->conn->dd_data, tcp_ctask);
1555                 dtask->digest = 0;
1556         }
1557
1558         debug_scsi("uns dout [itt 0x%x dlen %d sent %d]\n",
1559                    ctask->itt, ctask->unsol_count, tcp_ctask->sent);
1560         return 0;
1561 }
1562
1563 static int
1564 iscsi_send_unsol_pdu(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1565 {
1566         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1567         int rc;
1568
1569         if (tcp_ctask->xmstate & XMSTATE_UNS_HDR) {
1570                 BUG_ON(!ctask->unsol_count);
1571                 tcp_ctask->xmstate &= ~XMSTATE_UNS_HDR;
1572 send_hdr:
1573                 rc = iscsi_send_unsol_hdr(conn, ctask);
1574                 if (rc)
1575                         return rc;
1576         }
1577
1578         if (tcp_ctask->xmstate & XMSTATE_UNS_DATA) {
1579                 struct iscsi_data_task *dtask = &tcp_ctask->unsol_dtask;
1580                 int start = tcp_ctask->sent;
1581
1582                 rc = iscsi_send_data(ctask, &tcp_ctask->sendbuf, &tcp_ctask->sg,
1583                                      &tcp_ctask->sent, &ctask->data_count,
1584                                      &dtask->digestbuf, &dtask->digest);
1585                 ctask->unsol_count -= tcp_ctask->sent - start;
1586                 if (rc)
1587                         return rc;
1588                 tcp_ctask->xmstate &= ~XMSTATE_UNS_DATA;
1589                 /*
1590                  * Done with the Data-Out. Next, check if we need
1591                  * to send another unsolicited Data-Out.
1592                  */
1593                 if (ctask->unsol_count) {
1594                         debug_scsi("sending more uns\n");
1595                         tcp_ctask->xmstate |= XMSTATE_UNS_INIT;
1596                         goto send_hdr;
1597                 }
1598         }
1599         return 0;
1600 }
1601
1602 static int iscsi_send_sol_pdu(struct iscsi_conn *conn,
1603                               struct iscsi_cmd_task *ctask)
1604 {
1605         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1606         struct iscsi_session *session = conn->session;
1607         struct iscsi_r2t_info *r2t;
1608         struct iscsi_data_task *dtask;
1609         int left, rc;
1610
1611         if (tcp_ctask->xmstate & XMSTATE_SOL_HDR_INIT) {
1612                 if (!tcp_ctask->r2t) {
1613                         spin_lock_bh(&session->lock);
1614                         __kfifo_get(tcp_ctask->r2tqueue, (void*)&tcp_ctask->r2t,
1615                                     sizeof(void*));
1616                         spin_unlock_bh(&session->lock);
1617                 }
1618 send_hdr:
1619                 r2t = tcp_ctask->r2t;
1620                 dtask = &r2t->dtask;
1621
1622                 if (conn->hdrdgst_en)
1623                         iscsi_hdr_digest(conn, &r2t->headbuf,
1624                                         (u8*)dtask->hdrext);
1625                 tcp_ctask->xmstate &= ~XMSTATE_SOL_HDR_INIT;
1626                 tcp_ctask->xmstate |= XMSTATE_SOL_HDR;
1627         }
1628
1629         if (tcp_ctask->xmstate & XMSTATE_SOL_HDR) {
1630                 r2t = tcp_ctask->r2t;
1631                 dtask = &r2t->dtask;
1632
1633                 rc = iscsi_sendhdr(conn, &r2t->headbuf, r2t->data_count);
1634                 if (rc)
1635                         return rc;
1636                 tcp_ctask->xmstate &= ~XMSTATE_SOL_HDR;
1637                 tcp_ctask->xmstate |= XMSTATE_SOL_DATA;
1638
1639                 if (conn->datadgst_en) {
1640                         iscsi_data_digest_init(conn->dd_data, tcp_ctask);
1641                         dtask->digest = 0;
1642                 }
1643
1644                 iscsi_set_padding(tcp_ctask, r2t->data_count);
1645                 debug_scsi("sol dout [dsn %d itt 0x%x dlen %d sent %d]\n",
1646                         r2t->solicit_datasn - 1, ctask->itt, r2t->data_count,
1647                         r2t->sent);
1648         }
1649
1650         if (tcp_ctask->xmstate & XMSTATE_SOL_DATA) {
1651                 r2t = tcp_ctask->r2t;
1652                 dtask = &r2t->dtask;
1653
1654                 rc = iscsi_send_data(ctask, &r2t->sendbuf, &r2t->sg,
1655                                      &r2t->sent, &r2t->data_count,
1656                                      &dtask->digestbuf, &dtask->digest);
1657                 if (rc)
1658                         return rc;
1659                 tcp_ctask->xmstate &= ~XMSTATE_SOL_DATA;
1660
1661                 /*
1662                  * Done with this Data-Out. Next, check if we have
1663                  * to send another Data-Out for this R2T.
1664                  */
1665                 BUG_ON(r2t->data_length - r2t->sent < 0);
1666                 left = r2t->data_length - r2t->sent;
1667                 if (left) {
1668                         iscsi_solicit_data_cont(conn, ctask, r2t, left);
1669                         goto send_hdr;
1670                 }
1671
1672                 /*
1673                  * Done with this R2T. Check if there are more
1674                  * outstanding R2Ts ready to be processed.
1675                  */
1676                 spin_lock_bh(&session->lock);
1677                 tcp_ctask->r2t = NULL;
1678                 __kfifo_put(tcp_ctask->r2tpool.queue, (void*)&r2t,
1679                             sizeof(void*));
1680                 if (__kfifo_get(tcp_ctask->r2tqueue, (void*)&r2t,
1681                                 sizeof(void*))) {
1682                         tcp_ctask->r2t = r2t;
1683                         spin_unlock_bh(&session->lock);
1684                         goto send_hdr;
1685                 }
1686                 spin_unlock_bh(&session->lock);
1687         }
1688         return 0;
1689 }
1690
1691 /**
1692  * iscsi_tcp_ctask_xmit - xmit normal PDU task
1693  * @conn: iscsi connection
1694  * @ctask: iscsi command task
1695  *
1696  * Notes:
1697  *      The function can return -EAGAIN in which case caller must
1698  *      call it again later, or recover. '0' return code means successful
1699  *      xmit.
1700  *      The function is devided to logical helpers (above) for the different
1701  *      xmit stages.
1702  *
1703  *iscsi_send_cmd_hdr()
1704  *      XMSTATE_CMD_HDR_INIT - prepare Header and Data buffers Calculate
1705  *                             Header Digest
1706  *      XMSTATE_CMD_HDR_XMIT - Transmit header in progress
1707  *
1708  *iscsi_send_padding
1709  *      XMSTATE_W_PAD        - Prepare and send pading
1710  *      XMSTATE_W_RESEND_PAD - retry send pading
1711  *
1712  *iscsi_send_digest
1713  *      XMSTATE_W_RESEND_DATA_DIGEST - Finalize and send Data Digest
1714  *      XMSTATE_W_RESEND_DATA_DIGEST - retry sending digest
1715  *
1716  *iscsi_send_unsol_hdr
1717  *      XMSTATE_UNS_INIT     - prepare un-solicit data header and digest
1718  *      XMSTATE_UNS_HDR      - send un-solicit header
1719  *
1720  *iscsi_send_unsol_pdu
1721  *      XMSTATE_UNS_DATA     - send un-solicit data in progress
1722  *
1723  *iscsi_send_sol_pdu
1724  *      XMSTATE_SOL_HDR_INIT - solicit data header and digest initialize
1725  *      XMSTATE_SOL_HDR      - send solicit header
1726  *      XMSTATE_SOL_DATA     - send solicit data
1727  *
1728  *iscsi_tcp_ctask_xmit
1729  *      XMSTATE_IMM_DATA     - xmit managment data (??)
1730  **/
1731 static int
1732 iscsi_tcp_ctask_xmit(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1733 {
1734         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1735         int rc = 0;
1736
1737         debug_scsi("ctask deq [cid %d xmstate %x itt 0x%x]\n",
1738                 conn->id, tcp_ctask->xmstate, ctask->itt);
1739
1740         rc = iscsi_send_cmd_hdr(conn, ctask);
1741         if (rc)
1742                 return rc;
1743         if (ctask->sc->sc_data_direction != DMA_TO_DEVICE)
1744                 return 0;
1745
1746         if (tcp_ctask->xmstate & XMSTATE_IMM_DATA) {
1747                 rc = iscsi_send_data(ctask, &tcp_ctask->sendbuf, &tcp_ctask->sg,
1748                                      &tcp_ctask->sent, &ctask->imm_count,
1749                                      &tcp_ctask->immbuf, &tcp_ctask->immdigest);
1750                 if (rc)
1751                         return rc;
1752                 tcp_ctask->xmstate &= ~XMSTATE_IMM_DATA;
1753         }
1754
1755         rc = iscsi_send_unsol_pdu(conn, ctask);
1756         if (rc)
1757                 return rc;
1758
1759         rc = iscsi_send_sol_pdu(conn, ctask);
1760         if (rc)
1761                 return rc;
1762
1763         return rc;
1764 }
1765
1766 static struct iscsi_cls_conn *
1767 iscsi_tcp_conn_create(struct iscsi_cls_session *cls_session, uint32_t conn_idx)
1768 {
1769         struct iscsi_conn *conn;
1770         struct iscsi_cls_conn *cls_conn;
1771         struct iscsi_tcp_conn *tcp_conn;
1772
1773         cls_conn = iscsi_conn_setup(cls_session, conn_idx);
1774         if (!cls_conn)
1775                 return NULL;
1776         conn = cls_conn->dd_data;
1777         /*
1778          * due to strange issues with iser these are not set
1779          * in iscsi_conn_setup
1780          */
1781         conn->max_recv_dlength = ISCSI_DEF_MAX_RECV_SEG_LEN;
1782
1783         tcp_conn = kzalloc(sizeof(*tcp_conn), GFP_KERNEL);
1784         if (!tcp_conn)
1785                 goto tcp_conn_alloc_fail;
1786
1787         conn->dd_data = tcp_conn;
1788         tcp_conn->iscsi_conn = conn;
1789         tcp_conn->in_progress = IN_PROGRESS_WAIT_HEADER;
1790         /* initial operational parameters */
1791         tcp_conn->hdr_size = sizeof(struct iscsi_hdr);
1792
1793         tcp_conn->tx_hash.tfm = crypto_alloc_hash("crc32c", 0,
1794                                                   CRYPTO_ALG_ASYNC);
1795         tcp_conn->tx_hash.flags = 0;
1796         if (IS_ERR(tcp_conn->tx_hash.tfm)) {
1797                 printk(KERN_ERR "Could not create connection due to crc32c "
1798                        "loading error %ld. Make sure the crc32c module is "
1799                        "built as a module or into the kernel\n",
1800                         PTR_ERR(tcp_conn->tx_hash.tfm));
1801                 goto free_tcp_conn;
1802         }
1803
1804         tcp_conn->rx_hash.tfm = crypto_alloc_hash("crc32c", 0,
1805                                                   CRYPTO_ALG_ASYNC);
1806         tcp_conn->rx_hash.flags = 0;
1807         if (IS_ERR(tcp_conn->rx_hash.tfm)) {
1808                 printk(KERN_ERR "Could not create connection due to crc32c "
1809                        "loading error %ld. Make sure the crc32c module is "
1810                        "built as a module or into the kernel\n",
1811                         PTR_ERR(tcp_conn->rx_hash.tfm));
1812                 goto free_tx_tfm;
1813         }
1814
1815         return cls_conn;
1816
1817 free_tx_tfm:
1818         crypto_free_hash(tcp_conn->tx_hash.tfm);
1819 free_tcp_conn:
1820         kfree(tcp_conn);
1821 tcp_conn_alloc_fail:
1822         iscsi_conn_teardown(cls_conn);
1823         return NULL;
1824 }
1825
1826 static void
1827 iscsi_tcp_release_conn(struct iscsi_conn *conn)
1828 {
1829         struct iscsi_session *session = conn->session;
1830         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1831         struct socket *sock = tcp_conn->sock;
1832
1833         if (!sock)
1834                 return;
1835
1836         sock_hold(sock->sk);
1837         iscsi_conn_restore_callbacks(tcp_conn);
1838         sock_put(sock->sk);
1839
1840         spin_lock_bh(&session->lock);
1841         tcp_conn->sock = NULL;
1842         conn->recv_lock = NULL;
1843         spin_unlock_bh(&session->lock);
1844         sockfd_put(sock);
1845 }
1846
1847 static void
1848 iscsi_tcp_conn_destroy(struct iscsi_cls_conn *cls_conn)
1849 {
1850         struct iscsi_conn *conn = cls_conn->dd_data;
1851         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1852
1853         iscsi_tcp_release_conn(conn);
1854         iscsi_conn_teardown(cls_conn);
1855
1856         if (tcp_conn->tx_hash.tfm)
1857                 crypto_free_hash(tcp_conn->tx_hash.tfm);
1858         if (tcp_conn->rx_hash.tfm)
1859                 crypto_free_hash(tcp_conn->rx_hash.tfm);
1860
1861         kfree(tcp_conn);
1862 }
1863
1864 static void
1865 iscsi_tcp_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
1866 {
1867         struct iscsi_conn *conn = cls_conn->dd_data;
1868         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1869
1870         iscsi_conn_stop(cls_conn, flag);
1871         iscsi_tcp_release_conn(conn);
1872         tcp_conn->hdr_size = sizeof(struct iscsi_hdr);
1873 }
1874
1875 static int iscsi_tcp_get_addr(struct iscsi_conn *conn, struct socket *sock,
1876                               char *buf, int *port,
1877                               int (*getname)(struct socket *, struct sockaddr *,
1878                                         int *addrlen))
1879 {
1880         struct sockaddr_storage *addr;
1881         struct sockaddr_in6 *sin6;
1882         struct sockaddr_in *sin;
1883         int rc = 0, len;
1884
1885         addr = kmalloc(sizeof(*addr), GFP_KERNEL);
1886         if (!addr)
1887                 return -ENOMEM;
1888
1889         if (getname(sock, (struct sockaddr *) addr, &len)) {
1890                 rc = -ENODEV;
1891                 goto free_addr;
1892         }
1893
1894         switch (addr->ss_family) {
1895         case AF_INET:
1896                 sin = (struct sockaddr_in *)addr;
1897                 spin_lock_bh(&conn->session->lock);
1898                 sprintf(buf, NIPQUAD_FMT, NIPQUAD(sin->sin_addr.s_addr));
1899                 *port = be16_to_cpu(sin->sin_port);
1900                 spin_unlock_bh(&conn->session->lock);
1901                 break;
1902         case AF_INET6:
1903                 sin6 = (struct sockaddr_in6 *)addr;
1904                 spin_lock_bh(&conn->session->lock);
1905                 sprintf(buf, NIP6_FMT, NIP6(sin6->sin6_addr));
1906                 *port = be16_to_cpu(sin6->sin6_port);
1907                 spin_unlock_bh(&conn->session->lock);
1908                 break;
1909         }
1910 free_addr:
1911         kfree(addr);
1912         return rc;
1913 }
1914
1915 static int
1916 iscsi_tcp_conn_bind(struct iscsi_cls_session *cls_session,
1917                     struct iscsi_cls_conn *cls_conn, uint64_t transport_eph,
1918                     int is_leading)
1919 {
1920         struct iscsi_conn *conn = cls_conn->dd_data;
1921         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1922         struct sock *sk;
1923         struct socket *sock;
1924         int err;
1925
1926         /* lookup for existing socket */
1927         sock = sockfd_lookup((int)transport_eph, &err);
1928         if (!sock) {
1929                 printk(KERN_ERR "iscsi_tcp: sockfd_lookup failed %d\n", err);
1930                 return -EEXIST;
1931         }
1932         /*
1933          * copy these values now because if we drop the session
1934          * userspace may still want to query the values since we will
1935          * be using them for the reconnect
1936          */
1937         err = iscsi_tcp_get_addr(conn, sock, conn->portal_address,
1938                                  &conn->portal_port, kernel_getpeername);
1939         if (err)
1940                 goto free_socket;
1941
1942         err = iscsi_tcp_get_addr(conn, sock, conn->local_address,
1943                                 &conn->local_port, kernel_getsockname);
1944         if (err)
1945                 goto free_socket;
1946
1947         err = iscsi_conn_bind(cls_session, cls_conn, is_leading);
1948         if (err)
1949                 goto free_socket;
1950
1951         /* bind iSCSI connection and socket */
1952         tcp_conn->sock = sock;
1953
1954         /* setup Socket parameters */
1955         sk = sock->sk;
1956         sk->sk_reuse = 1;
1957         sk->sk_sndtimeo = 15 * HZ; /* FIXME: make it configurable */
1958         sk->sk_allocation = GFP_ATOMIC;
1959
1960         /* FIXME: disable Nagle's algorithm */
1961
1962         /*
1963          * Intercept TCP callbacks for sendfile like receive
1964          * processing.
1965          */
1966         conn->recv_lock = &sk->sk_callback_lock;
1967         iscsi_conn_set_callbacks(conn);
1968         tcp_conn->sendpage = tcp_conn->sock->ops->sendpage;
1969         /*
1970          * set receive state machine into initial state
1971          */
1972         tcp_conn->in_progress = IN_PROGRESS_WAIT_HEADER;
1973         return 0;
1974
1975 free_socket:
1976         sockfd_put(sock);
1977         return err;
1978 }
1979
1980 /* called with host lock */
1981 static void
1982 iscsi_tcp_mgmt_init(struct iscsi_conn *conn, struct iscsi_mgmt_task *mtask)
1983 {
1984         struct iscsi_tcp_mgmt_task *tcp_mtask = mtask->dd_data;
1985         tcp_mtask->xmstate = XMSTATE_IMM_HDR_INIT;
1986 }
1987
1988 static int
1989 iscsi_r2tpool_alloc(struct iscsi_session *session)
1990 {
1991         int i;
1992         int cmd_i;
1993
1994         /*
1995          * initialize per-task: R2T pool and xmit queue
1996          */
1997         for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
1998                 struct iscsi_cmd_task *ctask = session->cmds[cmd_i];
1999                 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
2000
2001                 /*
2002                  * pre-allocated x4 as much r2ts to handle race when
2003                  * target acks DataOut faster than we data_xmit() queues
2004                  * could replenish r2tqueue.
2005                  */
2006
2007                 /* R2T pool */
2008                 if (iscsi_pool_init(&tcp_ctask->r2tpool, session->max_r2t * 4,
2009                                     (void***)&tcp_ctask->r2ts,
2010                                     sizeof(struct iscsi_r2t_info))) {
2011                         goto r2t_alloc_fail;
2012                 }
2013
2014                 /* R2T xmit queue */
2015                 tcp_ctask->r2tqueue = kfifo_alloc(
2016                       session->max_r2t * 4 * sizeof(void*), GFP_KERNEL, NULL);
2017                 if (tcp_ctask->r2tqueue == ERR_PTR(-ENOMEM)) {
2018                         iscsi_pool_free(&tcp_ctask->r2tpool,
2019                                         (void**)tcp_ctask->r2ts);
2020                         goto r2t_alloc_fail;
2021                 }
2022         }
2023
2024         return 0;
2025
2026 r2t_alloc_fail:
2027         for (i = 0; i < cmd_i; i++) {
2028                 struct iscsi_cmd_task *ctask = session->cmds[i];
2029                 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
2030
2031                 kfifo_free(tcp_ctask->r2tqueue);
2032                 iscsi_pool_free(&tcp_ctask->r2tpool,
2033                                 (void**)tcp_ctask->r2ts);
2034         }
2035         return -ENOMEM;
2036 }
2037
2038 static void
2039 iscsi_r2tpool_free(struct iscsi_session *session)
2040 {
2041         int i;
2042
2043         for (i = 0; i < session->cmds_max; i++) {
2044                 struct iscsi_cmd_task *ctask = session->cmds[i];
2045                 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
2046
2047                 kfifo_free(tcp_ctask->r2tqueue);
2048                 iscsi_pool_free(&tcp_ctask->r2tpool,
2049                                 (void**)tcp_ctask->r2ts);
2050         }
2051 }
2052
2053 static int
2054 iscsi_conn_set_param(struct iscsi_cls_conn *cls_conn, enum iscsi_param param,
2055                      char *buf, int buflen)
2056 {
2057         struct iscsi_conn *conn = cls_conn->dd_data;
2058         struct iscsi_session *session = conn->session;
2059         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
2060         int value;
2061
2062         switch(param) {
2063         case ISCSI_PARAM_HDRDGST_EN:
2064                 iscsi_set_param(cls_conn, param, buf, buflen);
2065                 tcp_conn->hdr_size = sizeof(struct iscsi_hdr);
2066                 if (conn->hdrdgst_en)
2067                         tcp_conn->hdr_size += sizeof(__u32);
2068                 break;
2069         case ISCSI_PARAM_DATADGST_EN:
2070                 iscsi_set_param(cls_conn, param, buf, buflen);
2071                 tcp_conn->sendpage = conn->datadgst_en ?
2072                         sock_no_sendpage : tcp_conn->sock->ops->sendpage;
2073                 break;
2074         case ISCSI_PARAM_MAX_R2T:
2075                 sscanf(buf, "%d", &value);
2076                 if (session->max_r2t == roundup_pow_of_two(value))
2077                         break;
2078                 iscsi_r2tpool_free(session);
2079                 iscsi_set_param(cls_conn, param, buf, buflen);
2080                 if (session->max_r2t & (session->max_r2t - 1))
2081                         session->max_r2t = roundup_pow_of_two(session->max_r2t);
2082                 if (iscsi_r2tpool_alloc(session))
2083                         return -ENOMEM;
2084                 break;
2085         default:
2086                 return iscsi_set_param(cls_conn, param, buf, buflen);
2087         }
2088
2089         return 0;
2090 }
2091
2092 static int
2093 iscsi_tcp_conn_get_param(struct iscsi_cls_conn *cls_conn,
2094                          enum iscsi_param param, char *buf)
2095 {
2096         struct iscsi_conn *conn = cls_conn->dd_data;
2097         int len;
2098
2099         switch(param) {
2100         case ISCSI_PARAM_CONN_PORT:
2101                 spin_lock_bh(&conn->session->lock);
2102                 len = sprintf(buf, "%hu\n", conn->portal_port);
2103                 spin_unlock_bh(&conn->session->lock);
2104                 break;
2105         case ISCSI_PARAM_CONN_ADDRESS:
2106                 spin_lock_bh(&conn->session->lock);
2107                 len = sprintf(buf, "%s\n", conn->portal_address);
2108                 spin_unlock_bh(&conn->session->lock);
2109                 break;
2110         default:
2111                 return iscsi_conn_get_param(cls_conn, param, buf);
2112         }
2113
2114         return len;
2115 }
2116
2117 static int
2118 iscsi_tcp_host_get_param(struct Scsi_Host *shost, enum iscsi_host_param param,
2119                          char *buf)
2120 {
2121         struct iscsi_session *session = iscsi_hostdata(shost->hostdata);
2122         int len;
2123
2124         switch (param) {
2125         case ISCSI_HOST_PARAM_IPADDRESS:
2126                 spin_lock_bh(&session->lock);
2127                 if (!session->leadconn)
2128                         len = -ENODEV;
2129                 else
2130                         len = sprintf(buf, "%s\n",
2131                                      session->leadconn->local_address);
2132                 spin_unlock_bh(&session->lock);
2133                 break;
2134         default:
2135                 return iscsi_host_get_param(shost, param, buf);
2136         }
2137         return len;
2138 }
2139
2140 static void
2141 iscsi_conn_get_stats(struct iscsi_cls_conn *cls_conn, struct iscsi_stats *stats)
2142 {
2143         struct iscsi_conn *conn = cls_conn->dd_data;
2144         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
2145
2146         stats->txdata_octets = conn->txdata_octets;
2147         stats->rxdata_octets = conn->rxdata_octets;
2148         stats->scsicmd_pdus = conn->scsicmd_pdus_cnt;
2149         stats->dataout_pdus = conn->dataout_pdus_cnt;
2150         stats->scsirsp_pdus = conn->scsirsp_pdus_cnt;
2151         stats->datain_pdus = conn->datain_pdus_cnt;
2152         stats->r2t_pdus = conn->r2t_pdus_cnt;
2153         stats->tmfcmd_pdus = conn->tmfcmd_pdus_cnt;
2154         stats->tmfrsp_pdus = conn->tmfrsp_pdus_cnt;
2155         stats->custom_length = 3;
2156         strcpy(stats->custom[0].desc, "tx_sendpage_failures");
2157         stats->custom[0].value = tcp_conn->sendpage_failures_cnt;
2158         strcpy(stats->custom[1].desc, "rx_discontiguous_hdr");
2159         stats->custom[1].value = tcp_conn->discontiguous_hdr_cnt;
2160         strcpy(stats->custom[2].desc, "eh_abort_cnt");
2161         stats->custom[2].value = conn->eh_abort_cnt;
2162 }
2163
2164 static struct iscsi_cls_session *
2165 iscsi_tcp_session_create(struct iscsi_transport *iscsit,
2166                          struct scsi_transport_template *scsit,
2167                          uint16_t cmds_max, uint16_t qdepth,
2168                          uint32_t initial_cmdsn, uint32_t *hostno)
2169 {
2170         struct iscsi_cls_session *cls_session;
2171         struct iscsi_session *session;
2172         uint32_t hn;
2173         int cmd_i;
2174
2175         cls_session = iscsi_session_setup(iscsit, scsit, cmds_max, qdepth,
2176                                          sizeof(struct iscsi_tcp_cmd_task),
2177                                          sizeof(struct iscsi_tcp_mgmt_task),
2178                                          initial_cmdsn, &hn);
2179         if (!cls_session)
2180                 return NULL;
2181         *hostno = hn;
2182
2183         session = class_to_transport_session(cls_session);
2184         for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
2185                 struct iscsi_cmd_task *ctask = session->cmds[cmd_i];
2186                 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
2187
2188                 ctask->hdr = &tcp_ctask->hdr;
2189         }
2190
2191         for (cmd_i = 0; cmd_i < session->mgmtpool_max; cmd_i++) {
2192                 struct iscsi_mgmt_task *mtask = session->mgmt_cmds[cmd_i];
2193                 struct iscsi_tcp_mgmt_task *tcp_mtask = mtask->dd_data;
2194
2195                 mtask->hdr = &tcp_mtask->hdr;
2196         }
2197
2198         if (iscsi_r2tpool_alloc(class_to_transport_session(cls_session)))
2199                 goto r2tpool_alloc_fail;
2200
2201         return cls_session;
2202
2203 r2tpool_alloc_fail:
2204         iscsi_session_teardown(cls_session);
2205         return NULL;
2206 }
2207
2208 static void iscsi_tcp_session_destroy(struct iscsi_cls_session *cls_session)
2209 {
2210         iscsi_r2tpool_free(class_to_transport_session(cls_session));
2211         iscsi_session_teardown(cls_session);
2212 }
2213
2214 static int iscsi_tcp_slave_configure(struct scsi_device *sdev)
2215 {
2216         blk_queue_bounce_limit(sdev->request_queue, BLK_BOUNCE_ANY);
2217         blk_queue_dma_alignment(sdev->request_queue, 0);
2218         return 0;
2219 }
2220
2221 static struct scsi_host_template iscsi_sht = {
2222         .module                 = THIS_MODULE,
2223         .name                   = "iSCSI Initiator over TCP/IP",
2224         .queuecommand           = iscsi_queuecommand,
2225         .change_queue_depth     = iscsi_change_queue_depth,
2226         .can_queue              = ISCSI_DEF_XMIT_CMDS_MAX - 1,
2227         .sg_tablesize           = ISCSI_SG_TABLESIZE,
2228         .max_sectors            = 0xFFFF,
2229         .cmd_per_lun            = ISCSI_DEF_CMD_PER_LUN,
2230         .eh_abort_handler       = iscsi_eh_abort,
2231         .eh_host_reset_handler  = iscsi_eh_host_reset,
2232         .use_clustering         = DISABLE_CLUSTERING,
2233         .slave_configure        = iscsi_tcp_slave_configure,
2234         .proc_name              = "iscsi_tcp",
2235         .this_id                = -1,
2236 };
2237
2238 static struct iscsi_transport iscsi_tcp_transport = {
2239         .owner                  = THIS_MODULE,
2240         .name                   = "tcp",
2241         .caps                   = CAP_RECOVERY_L0 | CAP_MULTI_R2T | CAP_HDRDGST
2242                                   | CAP_DATADGST,
2243         .param_mask             = ISCSI_MAX_RECV_DLENGTH |
2244                                   ISCSI_MAX_XMIT_DLENGTH |
2245                                   ISCSI_HDRDGST_EN |
2246                                   ISCSI_DATADGST_EN |
2247                                   ISCSI_INITIAL_R2T_EN |
2248                                   ISCSI_MAX_R2T |
2249                                   ISCSI_IMM_DATA_EN |
2250                                   ISCSI_FIRST_BURST |
2251                                   ISCSI_MAX_BURST |
2252                                   ISCSI_PDU_INORDER_EN |
2253                                   ISCSI_DATASEQ_INORDER_EN |
2254                                   ISCSI_ERL |
2255                                   ISCSI_CONN_PORT |
2256                                   ISCSI_CONN_ADDRESS |
2257                                   ISCSI_EXP_STATSN |
2258                                   ISCSI_PERSISTENT_PORT |
2259                                   ISCSI_PERSISTENT_ADDRESS |
2260                                   ISCSI_TARGET_NAME | ISCSI_TPGT |
2261                                   ISCSI_USERNAME | ISCSI_PASSWORD |
2262                                   ISCSI_USERNAME_IN | ISCSI_PASSWORD_IN,
2263         .host_param_mask        = ISCSI_HOST_HWADDRESS | ISCSI_HOST_IPADDRESS |
2264                                   ISCSI_HOST_INITIATOR_NAME |
2265                                   ISCSI_HOST_NETDEV_NAME,
2266         .host_template          = &iscsi_sht,
2267         .conndata_size          = sizeof(struct iscsi_conn),
2268         .max_conn               = 1,
2269         .max_cmd_len            = ISCSI_TCP_MAX_CMD_LEN,
2270         /* session management */
2271         .create_session         = iscsi_tcp_session_create,
2272         .destroy_session        = iscsi_tcp_session_destroy,
2273         /* connection management */
2274         .create_conn            = iscsi_tcp_conn_create,
2275         .bind_conn              = iscsi_tcp_conn_bind,
2276         .destroy_conn           = iscsi_tcp_conn_destroy,
2277         .set_param              = iscsi_conn_set_param,
2278         .get_conn_param         = iscsi_tcp_conn_get_param,
2279         .get_session_param      = iscsi_session_get_param,
2280         .start_conn             = iscsi_conn_start,
2281         .stop_conn              = iscsi_tcp_conn_stop,
2282         /* iscsi host params */
2283         .get_host_param         = iscsi_tcp_host_get_param,
2284         .set_host_param         = iscsi_host_set_param,
2285         /* IO */
2286         .send_pdu               = iscsi_conn_send_pdu,
2287         .get_stats              = iscsi_conn_get_stats,
2288         .init_cmd_task          = iscsi_tcp_cmd_init,
2289         .init_mgmt_task         = iscsi_tcp_mgmt_init,
2290         .xmit_cmd_task          = iscsi_tcp_ctask_xmit,
2291         .xmit_mgmt_task         = iscsi_tcp_mtask_xmit,
2292         .cleanup_cmd_task       = iscsi_tcp_cleanup_ctask,
2293         /* recovery */
2294         .session_recovery_timedout = iscsi_session_recovery_timedout,
2295 };
2296
2297 static int __init
2298 iscsi_tcp_init(void)
2299 {
2300         if (iscsi_max_lun < 1) {
2301                 printk(KERN_ERR "iscsi_tcp: Invalid max_lun value of %u\n",
2302                        iscsi_max_lun);
2303                 return -EINVAL;
2304         }
2305         iscsi_tcp_transport.max_lun = iscsi_max_lun;
2306
2307         if (!iscsi_register_transport(&iscsi_tcp_transport))
2308                 return -ENODEV;
2309
2310         return 0;
2311 }
2312
2313 static void __exit
2314 iscsi_tcp_exit(void)
2315 {
2316         iscsi_unregister_transport(&iscsi_tcp_transport);
2317 }
2318
2319 module_init(iscsi_tcp_init);
2320 module_exit(iscsi_tcp_exit);