2 * iSCSI Initiator over TCP/IP Data-Path
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
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.
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.
20 * See the file COPYING included with this distribution for more details.
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>
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>
45 #include "iscsi_tcp.h"
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");
55 #define debug_tcp(fmt...) printk(KERN_INFO "tcp: " fmt)
57 #define debug_tcp(fmt...)
60 static struct scsi_transport_template *iscsi_tcp_scsi_transport;
61 static struct scsi_host_template iscsi_sht;
62 static struct iscsi_transport iscsi_tcp_transport;
64 static unsigned int iscsi_max_lun = 512;
65 module_param_named(max_lun, iscsi_max_lun, uint, S_IRUGO);
67 static int iscsi_tcp_hdr_recv_done(struct iscsi_tcp_conn *tcp_conn,
68 struct iscsi_segment *segment);
71 * Scatterlist handling: inside the iscsi_segment, we
72 * remember an index into the scatterlist, and set data/size
73 * to the current scatterlist entry. For highmem pages, we
76 * Note that the page is unmapped when we return from
77 * TCP's data_ready handler, so we may end up mapping and
78 * unmapping the same page repeatedly. The whole reason
79 * for this is that we shouldn't keep the page mapped
80 * outside the softirq.
84 * iscsi_tcp_segment_init_sg - init indicated scatterlist entry
85 * @segment: the buffer object
87 * @offset: byte offset into that sg entry
89 * This function sets up the segment so that subsequent
90 * data is copied to the indicated sg entry, at the given
94 iscsi_tcp_segment_init_sg(struct iscsi_segment *segment,
95 struct scatterlist *sg, unsigned int offset)
98 segment->sg_offset = offset;
99 segment->size = min(sg->length - offset,
100 segment->total_size - segment->total_copied);
101 segment->data = NULL;
105 * iscsi_tcp_segment_map - map the current S/G page
106 * @segment: iscsi_segment
107 * @recv: 1 if called from recv path
109 * We only need to possibly kmap data if scatter lists are being used,
110 * because the iscsi passthrough and internal IO paths will never use high
114 iscsi_tcp_segment_map(struct iscsi_segment *segment, int recv)
116 struct scatterlist *sg;
118 if (segment->data != NULL || !segment->sg)
122 BUG_ON(segment->sg_mapped);
123 BUG_ON(sg->length == 0);
126 * If the page count is greater than one it is ok to send
127 * to the network layer's zero copy send path. If not we
128 * have to go the slow sendmsg path. We always map for the
131 if (page_count(sg_page(sg)) >= 1 && !recv)
134 debug_tcp("iscsi_tcp_segment_map %s %p\n", recv ? "recv" : "xmit",
136 segment->sg_mapped = kmap_atomic(sg_page(sg), KM_SOFTIRQ0);
137 segment->data = segment->sg_mapped + sg->offset + segment->sg_offset;
141 iscsi_tcp_segment_unmap(struct iscsi_segment *segment)
143 debug_tcp("iscsi_tcp_segment_unmap %p\n", segment);
145 if (segment->sg_mapped) {
146 debug_tcp("iscsi_tcp_segment_unmap valid\n");
147 kunmap_atomic(segment->sg_mapped, KM_SOFTIRQ0);
148 segment->sg_mapped = NULL;
149 segment->data = NULL;
154 * Splice the digest buffer into the buffer
157 iscsi_tcp_segment_splice_digest(struct iscsi_segment *segment, void *digest)
159 segment->data = digest;
160 segment->digest_len = ISCSI_DIGEST_SIZE;
161 segment->total_size += ISCSI_DIGEST_SIZE;
162 segment->size = ISCSI_DIGEST_SIZE;
165 segment->hash = NULL;
169 * iscsi_tcp_segment_done - check whether the segment is complete
170 * @segment: iscsi segment to check
171 * @recv: set to one of this is called from the recv path
172 * @copied: number of bytes copied
174 * Check if we're done receiving this segment. If the receive
175 * buffer is full but we expect more data, move on to the
176 * next entry in the scatterlist.
178 * If the amount of data we received isn't a multiple of 4,
179 * we will transparently receive the pad bytes, too.
181 * This function must be re-entrant.
184 iscsi_tcp_segment_done(struct iscsi_segment *segment, int recv, unsigned copied)
186 static unsigned char padbuf[ISCSI_PAD_LEN];
187 struct scatterlist sg;
190 debug_tcp("copied %u %u size %u %s\n", segment->copied, copied,
191 segment->size, recv ? "recv" : "xmit");
192 if (segment->hash && copied) {
194 * If a segment is kmapd we must unmap it before sending
195 * to the crypto layer since that will try to kmap it again.
197 iscsi_tcp_segment_unmap(segment);
199 if (!segment->data) {
200 sg_init_table(&sg, 1);
201 sg_set_page(&sg, sg_page(segment->sg), copied,
202 segment->copied + segment->sg_offset +
203 segment->sg->offset);
205 sg_init_one(&sg, segment->data + segment->copied,
207 crypto_hash_update(segment->hash, &sg, copied);
210 segment->copied += copied;
211 if (segment->copied < segment->size) {
212 iscsi_tcp_segment_map(segment, recv);
216 segment->total_copied += segment->copied;
220 /* Unmap the current scatterlist page, if there is one. */
221 iscsi_tcp_segment_unmap(segment);
223 /* Do we have more scatterlist entries? */
224 debug_tcp("total copied %u total size %u\n", segment->total_copied,
225 segment->total_size);
226 if (segment->total_copied < segment->total_size) {
227 /* Proceed to the next entry in the scatterlist. */
228 iscsi_tcp_segment_init_sg(segment, sg_next(segment->sg),
230 iscsi_tcp_segment_map(segment, recv);
231 BUG_ON(segment->size == 0);
235 /* Do we need to handle padding? */
236 pad = iscsi_padding(segment->total_copied);
238 debug_tcp("consume %d pad bytes\n", pad);
239 segment->total_size += pad;
241 segment->data = padbuf;
246 * Set us up for transferring the data digest. hdr digest
247 * is completely handled in hdr done function.
250 crypto_hash_final(segment->hash, segment->digest);
251 iscsi_tcp_segment_splice_digest(segment,
252 recv ? segment->recv_digest : segment->digest);
260 * iscsi_tcp_xmit_segment - transmit segment
261 * @tcp_conn: the iSCSI TCP connection
262 * @segment: the buffer to transmnit
264 * This function transmits as much of the buffer as
265 * the network layer will accept, and returns the number of
268 * If CRC hashing is enabled, the function will compute the
269 * hash as it goes. When the entire segment has been transmitted,
270 * it will retrieve the hash value and send it as well.
273 iscsi_tcp_xmit_segment(struct iscsi_tcp_conn *tcp_conn,
274 struct iscsi_segment *segment)
276 struct socket *sk = tcp_conn->sock;
277 unsigned int copied = 0;
280 while (!iscsi_tcp_segment_done(segment, 0, r)) {
281 struct scatterlist *sg;
282 unsigned int offset, copy;
286 offset = segment->copied;
287 copy = segment->size - offset;
289 if (segment->total_copied + segment->size < segment->total_size)
292 /* Use sendpage if we can; else fall back to sendmsg */
293 if (!segment->data) {
295 offset += segment->sg_offset + sg->offset;
296 r = tcp_conn->sendpage(sk, sg_page(sg), offset, copy,
299 struct msghdr msg = { .msg_flags = flags };
301 .iov_base = segment->data + offset,
305 r = kernel_sendmsg(sk, &msg, &iov, 1, copy);
309 iscsi_tcp_segment_unmap(segment);
310 if (copied || r == -EAGAIN)
320 * iscsi_tcp_segment_recv - copy data to segment
321 * @tcp_conn: the iSCSI TCP connection
322 * @segment: the buffer to copy to
324 * @len: amount of data available
326 * This function copies up to @len bytes to the
327 * given buffer, and returns the number of bytes
328 * consumed, which can actually be less than @len.
330 * If hash digest is enabled, the function will update the
331 * hash while copying.
332 * Combining these two operations doesn't buy us a lot (yet),
333 * but in the future we could implement combined copy+crc,
334 * just way we do for network layer checksums.
337 iscsi_tcp_segment_recv(struct iscsi_tcp_conn *tcp_conn,
338 struct iscsi_segment *segment, const void *ptr,
341 unsigned int copy = 0, copied = 0;
343 while (!iscsi_tcp_segment_done(segment, 1, copy)) {
345 debug_tcp("iscsi_tcp_segment_recv copied %d bytes\n",
350 copy = min(len - copied, segment->size - segment->copied);
351 debug_tcp("iscsi_tcp_segment_recv copying %d\n", copy);
352 memcpy(segment->data + segment->copied, ptr + copied, copy);
359 iscsi_tcp_dgst_header(struct hash_desc *hash, const void *hdr, size_t hdrlen,
360 unsigned char digest[ISCSI_DIGEST_SIZE])
362 struct scatterlist sg;
364 sg_init_one(&sg, hdr, hdrlen);
365 crypto_hash_digest(hash, &sg, hdrlen, digest);
369 iscsi_tcp_dgst_verify(struct iscsi_tcp_conn *tcp_conn,
370 struct iscsi_segment *segment)
372 if (!segment->digest_len)
375 if (memcmp(segment->recv_digest, segment->digest,
376 segment->digest_len)) {
377 debug_scsi("digest mismatch\n");
385 * Helper function to set up segment buffer
388 __iscsi_segment_init(struct iscsi_segment *segment, size_t size,
389 iscsi_segment_done_fn_t *done, struct hash_desc *hash)
391 memset(segment, 0, sizeof(*segment));
392 segment->total_size = size;
393 segment->done = done;
396 segment->hash = hash;
397 crypto_hash_init(hash);
402 iscsi_segment_init_linear(struct iscsi_segment *segment, void *data,
403 size_t size, iscsi_segment_done_fn_t *done,
404 struct hash_desc *hash)
406 __iscsi_segment_init(segment, size, done, hash);
407 segment->data = data;
408 segment->size = size;
412 iscsi_segment_seek_sg(struct iscsi_segment *segment,
413 struct scatterlist *sg_list, unsigned int sg_count,
414 unsigned int offset, size_t size,
415 iscsi_segment_done_fn_t *done, struct hash_desc *hash)
417 struct scatterlist *sg;
420 debug_scsi("iscsi_segment_seek_sg offset %u size %llu\n",
422 __iscsi_segment_init(segment, size, done, hash);
423 for_each_sg(sg_list, sg, sg_count, i) {
424 debug_scsi("sg %d, len %u offset %u\n", i, sg->length,
426 if (offset < sg->length) {
427 iscsi_tcp_segment_init_sg(segment, sg, offset);
430 offset -= sg->length;
433 return ISCSI_ERR_DATA_OFFSET;
437 * iscsi_tcp_hdr_recv_prep - prep segment for hdr reception
438 * @tcp_conn: iscsi connection to prep for
440 * This function always passes NULL for the hash argument, because when this
441 * function is called we do not yet know the final size of the header and want
442 * to delay the digest processing until we know that.
445 iscsi_tcp_hdr_recv_prep(struct iscsi_tcp_conn *tcp_conn)
447 debug_tcp("iscsi_tcp_hdr_recv_prep(%p%s)\n", tcp_conn,
448 tcp_conn->iscsi_conn->hdrdgst_en ? ", digest enabled" : "");
449 iscsi_segment_init_linear(&tcp_conn->in.segment,
450 tcp_conn->in.hdr_buf, sizeof(struct iscsi_hdr),
451 iscsi_tcp_hdr_recv_done, NULL);
455 * Handle incoming reply to any other type of command
458 iscsi_tcp_data_recv_done(struct iscsi_tcp_conn *tcp_conn,
459 struct iscsi_segment *segment)
461 struct iscsi_conn *conn = tcp_conn->iscsi_conn;
464 if (!iscsi_tcp_dgst_verify(tcp_conn, segment))
465 return ISCSI_ERR_DATA_DGST;
467 rc = iscsi_complete_pdu(conn, tcp_conn->in.hdr,
468 conn->data, tcp_conn->in.datalen);
472 iscsi_tcp_hdr_recv_prep(tcp_conn);
477 iscsi_tcp_data_recv_prep(struct iscsi_tcp_conn *tcp_conn)
479 struct iscsi_conn *conn = tcp_conn->iscsi_conn;
480 struct hash_desc *rx_hash = NULL;
482 if (conn->datadgst_en &
483 !(conn->session->tt->caps & CAP_DIGEST_OFFLOAD))
484 rx_hash = &tcp_conn->rx_hash;
486 iscsi_segment_init_linear(&tcp_conn->in.segment,
487 conn->data, tcp_conn->in.datalen,
488 iscsi_tcp_data_recv_done, rx_hash);
492 * must be called with session lock
494 static void iscsi_tcp_cleanup_task(struct iscsi_task *task)
496 struct iscsi_tcp_task *tcp_task = task->dd_data;
497 struct iscsi_r2t_info *r2t;
499 /* nothing to do for mgmt or pending tasks */
500 if (!task->sc || task->state == ISCSI_TASK_PENDING)
503 /* flush task's r2t queues */
504 while (__kfifo_get(tcp_task->r2tqueue, (void*)&r2t, sizeof(void*))) {
505 __kfifo_put(tcp_task->r2tpool.queue, (void*)&r2t,
507 debug_scsi("iscsi_tcp_cleanup_task pending r2t dropped\n");
512 __kfifo_put(tcp_task->r2tpool.queue, (void*)&r2t,
514 tcp_task->r2t = NULL;
519 * iscsi_data_in - SCSI Data-In Response processing
520 * @conn: iscsi connection
521 * @task: scsi command task
524 iscsi_data_in(struct iscsi_conn *conn, struct iscsi_task *task)
526 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
527 struct iscsi_tcp_task *tcp_task = task->dd_data;
528 struct iscsi_data_rsp *rhdr = (struct iscsi_data_rsp *)tcp_conn->in.hdr;
529 int datasn = be32_to_cpu(rhdr->datasn);
530 unsigned total_in_length = scsi_in(task->sc)->length;
532 iscsi_update_cmdsn(conn->session, (struct iscsi_nopin*)rhdr);
533 if (tcp_conn->in.datalen == 0)
536 if (tcp_task->exp_datasn != datasn) {
537 debug_tcp("%s: task->exp_datasn(%d) != rhdr->datasn(%d)\n",
538 __func__, tcp_task->exp_datasn, datasn);
539 return ISCSI_ERR_DATASN;
542 tcp_task->exp_datasn++;
544 tcp_task->data_offset = be32_to_cpu(rhdr->offset);
545 if (tcp_task->data_offset + tcp_conn->in.datalen > total_in_length) {
546 debug_tcp("%s: data_offset(%d) + data_len(%d) > total_length_in(%d)\n",
547 __func__, tcp_task->data_offset,
548 tcp_conn->in.datalen, total_in_length);
549 return ISCSI_ERR_DATA_OFFSET;
552 conn->datain_pdus_cnt++;
557 * iscsi_r2t_rsp - iSCSI R2T Response processing
558 * @conn: iscsi connection
559 * @task: scsi command task
562 iscsi_r2t_rsp(struct iscsi_conn *conn, struct iscsi_task *task)
564 struct iscsi_session *session = conn->session;
565 struct iscsi_tcp_task *tcp_task = task->dd_data;
566 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
567 struct iscsi_r2t_rsp *rhdr = (struct iscsi_r2t_rsp *)tcp_conn->in.hdr;
568 struct iscsi_r2t_info *r2t;
569 int r2tsn = be32_to_cpu(rhdr->r2tsn);
572 if (tcp_conn->in.datalen) {
573 iscsi_conn_printk(KERN_ERR, conn,
574 "invalid R2t with datalen %d\n",
575 tcp_conn->in.datalen);
576 return ISCSI_ERR_DATALEN;
579 if (tcp_task->exp_datasn != r2tsn){
580 debug_tcp("%s: task->exp_datasn(%d) != rhdr->r2tsn(%d)\n",
581 __func__, tcp_task->exp_datasn, r2tsn);
582 return ISCSI_ERR_R2TSN;
585 /* fill-in new R2T associated with the task */
586 iscsi_update_cmdsn(session, (struct iscsi_nopin*)rhdr);
588 if (!task->sc || session->state != ISCSI_STATE_LOGGED_IN) {
589 iscsi_conn_printk(KERN_INFO, conn,
590 "dropping R2T itt %d in recovery.\n",
595 rc = __kfifo_get(tcp_task->r2tpool.queue, (void*)&r2t, sizeof(void*));
597 iscsi_conn_printk(KERN_ERR, conn, "Could not allocate R2T. "
598 "Target has sent more R2Ts than it "
599 "negotiated for or driver has has leaked.\n");
600 return ISCSI_ERR_PROTO;
603 r2t->exp_statsn = rhdr->statsn;
604 r2t->data_length = be32_to_cpu(rhdr->data_length);
605 if (r2t->data_length == 0) {
606 iscsi_conn_printk(KERN_ERR, conn,
607 "invalid R2T with zero data len\n");
608 __kfifo_put(tcp_task->r2tpool.queue, (void*)&r2t,
610 return ISCSI_ERR_DATALEN;
613 if (r2t->data_length > session->max_burst)
614 debug_scsi("invalid R2T with data len %u and max burst %u."
615 "Attempting to execute request.\n",
616 r2t->data_length, session->max_burst);
618 r2t->data_offset = be32_to_cpu(rhdr->data_offset);
619 if (r2t->data_offset + r2t->data_length > scsi_out(task->sc)->length) {
620 iscsi_conn_printk(KERN_ERR, conn,
621 "invalid R2T with data len %u at offset %u "
622 "and total length %d\n", r2t->data_length,
623 r2t->data_offset, scsi_out(task->sc)->length);
624 __kfifo_put(tcp_task->r2tpool.queue, (void*)&r2t,
626 return ISCSI_ERR_DATALEN;
629 r2t->ttt = rhdr->ttt; /* no flip */
633 tcp_task->exp_datasn = r2tsn + 1;
634 __kfifo_put(tcp_task->r2tqueue, (void*)&r2t, sizeof(void*));
635 conn->r2t_pdus_cnt++;
637 iscsi_requeue_task(task);
642 * Handle incoming reply to DataIn command
645 iscsi_tcp_process_data_in(struct iscsi_tcp_conn *tcp_conn,
646 struct iscsi_segment *segment)
648 struct iscsi_conn *conn = tcp_conn->iscsi_conn;
649 struct iscsi_hdr *hdr = tcp_conn->in.hdr;
652 if (!iscsi_tcp_dgst_verify(tcp_conn, segment))
653 return ISCSI_ERR_DATA_DGST;
655 /* check for non-exceptional status */
656 if (hdr->flags & ISCSI_FLAG_DATA_STATUS) {
657 rc = iscsi_complete_pdu(conn, tcp_conn->in.hdr, NULL, 0);
662 iscsi_tcp_hdr_recv_prep(tcp_conn);
667 * iscsi_tcp_hdr_dissect - process PDU header
668 * @conn: iSCSI connection
671 * This function analyzes the header of the PDU received,
672 * and performs several sanity checks. If the PDU is accompanied
673 * by data, the receive buffer is set up to copy the incoming data
674 * to the correct location.
677 iscsi_tcp_hdr_dissect(struct iscsi_conn *conn, struct iscsi_hdr *hdr)
679 int rc = 0, opcode, ahslen;
680 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
681 struct iscsi_task *task;
683 /* verify PDU length */
684 tcp_conn->in.datalen = ntoh24(hdr->dlength);
685 if (tcp_conn->in.datalen > conn->max_recv_dlength) {
686 iscsi_conn_printk(KERN_ERR, conn,
687 "iscsi_tcp: datalen %d > %d\n",
688 tcp_conn->in.datalen, conn->max_recv_dlength);
689 return ISCSI_ERR_DATALEN;
692 /* Additional header segments. So far, we don't
693 * process additional headers.
695 ahslen = hdr->hlength << 2;
697 opcode = hdr->opcode & ISCSI_OPCODE_MASK;
698 /* verify itt (itt encoding: age+cid+itt) */
699 rc = iscsi_verify_itt(conn, hdr->itt);
703 debug_tcp("opcode 0x%x ahslen %d datalen %d\n",
704 opcode, ahslen, tcp_conn->in.datalen);
707 case ISCSI_OP_SCSI_DATA_IN:
708 spin_lock(&conn->session->lock);
709 task = iscsi_itt_to_ctask(conn, hdr->itt);
711 rc = ISCSI_ERR_BAD_ITT;
713 rc = iscsi_data_in(conn, task);
715 spin_unlock(&conn->session->lock);
719 if (tcp_conn->in.datalen) {
720 struct iscsi_tcp_task *tcp_task = task->dd_data;
721 struct hash_desc *rx_hash = NULL;
722 struct scsi_data_buffer *sdb = scsi_in(task->sc);
725 * Setup copy of Data-In into the Scsi_Cmnd
727 * We set up the iscsi_segment to point to the next
728 * scatterlist entry to copy to. As we go along,
729 * we move on to the next scatterlist entry and
730 * update the digest per-entry.
732 if (conn->datadgst_en &&
733 !(conn->session->tt->caps & CAP_DIGEST_OFFLOAD))
734 rx_hash = &tcp_conn->rx_hash;
736 debug_tcp("iscsi_tcp_begin_data_in(%p, offset=%d, "
737 "datalen=%d)\n", tcp_conn,
738 tcp_task->data_offset,
739 tcp_conn->in.datalen);
740 rc = iscsi_segment_seek_sg(&tcp_conn->in.segment,
743 tcp_task->data_offset,
744 tcp_conn->in.datalen,
745 iscsi_tcp_process_data_in,
747 spin_unlock(&conn->session->lock);
750 rc = __iscsi_complete_pdu(conn, hdr, NULL, 0);
751 spin_unlock(&conn->session->lock);
753 case ISCSI_OP_SCSI_CMD_RSP:
754 if (tcp_conn->in.datalen) {
755 iscsi_tcp_data_recv_prep(tcp_conn);
758 rc = iscsi_complete_pdu(conn, hdr, NULL, 0);
761 spin_lock(&conn->session->lock);
762 task = iscsi_itt_to_ctask(conn, hdr->itt);
764 rc = ISCSI_ERR_BAD_ITT;
766 rc = ISCSI_ERR_AHSLEN;
767 else if (task->sc->sc_data_direction == DMA_TO_DEVICE)
768 rc = iscsi_r2t_rsp(conn, task);
770 rc = ISCSI_ERR_PROTO;
771 spin_unlock(&conn->session->lock);
773 case ISCSI_OP_LOGIN_RSP:
774 case ISCSI_OP_TEXT_RSP:
775 case ISCSI_OP_REJECT:
776 case ISCSI_OP_ASYNC_EVENT:
778 * It is possible that we could get a PDU with a buffer larger
779 * than 8K, but there are no targets that currently do this.
780 * For now we fail until we find a vendor that needs it
782 if (ISCSI_DEF_MAX_RECV_SEG_LEN < tcp_conn->in.datalen) {
783 iscsi_conn_printk(KERN_ERR, conn,
784 "iscsi_tcp: received buffer of "
785 "len %u but conn buffer is only %u "
787 tcp_conn->in.datalen,
788 ISCSI_DEF_MAX_RECV_SEG_LEN, opcode);
789 rc = ISCSI_ERR_PROTO;
793 /* If there's data coming in with the response,
794 * receive it to the connection's buffer.
796 if (tcp_conn->in.datalen) {
797 iscsi_tcp_data_recv_prep(tcp_conn);
801 case ISCSI_OP_LOGOUT_RSP:
802 case ISCSI_OP_NOOP_IN:
803 case ISCSI_OP_SCSI_TMFUNC_RSP:
804 rc = iscsi_complete_pdu(conn, hdr, NULL, 0);
807 rc = ISCSI_ERR_BAD_OPCODE;
812 /* Anything that comes with data should have
813 * been handled above. */
814 if (tcp_conn->in.datalen)
815 return ISCSI_ERR_PROTO;
816 iscsi_tcp_hdr_recv_prep(tcp_conn);
823 * iscsi_tcp_hdr_recv_done - process PDU header
825 * This is the callback invoked when the PDU header has
826 * been received. If the header is followed by additional
827 * header segments, we go back for more data.
830 iscsi_tcp_hdr_recv_done(struct iscsi_tcp_conn *tcp_conn,
831 struct iscsi_segment *segment)
833 struct iscsi_conn *conn = tcp_conn->iscsi_conn;
834 struct iscsi_hdr *hdr;
836 /* Check if there are additional header segments
837 * *prior* to computing the digest, because we
838 * may need to go back to the caller for more.
840 hdr = (struct iscsi_hdr *) tcp_conn->in.hdr_buf;
841 if (segment->copied == sizeof(struct iscsi_hdr) && hdr->hlength) {
842 /* Bump the header length - the caller will
843 * just loop around and get the AHS for us, and
845 unsigned int ahslen = hdr->hlength << 2;
847 /* Make sure we don't overflow */
848 if (sizeof(*hdr) + ahslen > sizeof(tcp_conn->in.hdr_buf))
849 return ISCSI_ERR_AHSLEN;
851 segment->total_size += ahslen;
852 segment->size += ahslen;
856 /* We're done processing the header. See if we're doing
857 * header digests; if so, set up the recv_digest buffer
858 * and go back for more. */
859 if (conn->hdrdgst_en) {
860 if (segment->digest_len == 0) {
862 * Even if we offload the digest processing we
863 * splice it in so we can increment the skb/segment
864 * counters in preparation for the data segment.
866 iscsi_tcp_segment_splice_digest(segment,
867 segment->recv_digest);
871 if (!(conn->session->tt->caps & CAP_DIGEST_OFFLOAD)) {
872 iscsi_tcp_dgst_header(&tcp_conn->rx_hash, hdr,
873 segment->total_copied - ISCSI_DIGEST_SIZE,
876 if (!iscsi_tcp_dgst_verify(tcp_conn, segment))
877 return ISCSI_ERR_HDR_DGST;
881 tcp_conn->in.hdr = hdr;
882 return iscsi_tcp_hdr_dissect(conn, hdr);
885 inline int iscsi_tcp_recv_segment_is_hdr(struct iscsi_tcp_conn *tcp_conn)
887 return tcp_conn->in.segment.done == iscsi_tcp_hdr_recv_done;
891 ISCSI_TCP_SEGMENT_DONE, /* curr seg has been processed */
892 ISCSI_TCP_SKB_DONE, /* skb is out of data */
893 ISCSI_TCP_CONN_ERR, /* iscsi layer has fired a conn err */
894 ISCSI_TCP_SUSPENDED, /* conn is suspended */
898 * iscsi_tcp_recv_skb - Process skb
899 * @conn: iscsi connection
900 * @skb: network buffer with header and/or data segment
901 * @offset: offset in skb
902 * @offload: bool indicating if transfer was offloaded
904 int iscsi_tcp_recv_skb(struct iscsi_conn *conn, struct sk_buff *skb,
905 unsigned int offset, bool offloaded, int *status)
907 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
908 struct iscsi_segment *segment = &tcp_conn->in.segment;
909 struct skb_seq_state seq;
910 unsigned int consumed = 0;
913 debug_tcp("in %d bytes\n", skb->len - offset);
915 if (unlikely(conn->suspend_rx)) {
916 debug_tcp("conn %d Rx suspended!\n", conn->id);
917 *status = ISCSI_TCP_SUSPENDED;
922 segment->total_copied = segment->total_size;
926 skb_prepare_seq_read(skb, offset, skb->len, &seq);
931 avail = skb_seq_read(consumed, &ptr, &seq);
933 debug_tcp("no more data avail. Consumed %d\n",
935 *status = ISCSI_TCP_SKB_DONE;
936 skb_abort_seq_read(&seq);
939 BUG_ON(segment->copied >= segment->size);
941 debug_tcp("skb %p ptr=%p avail=%u\n", skb, ptr, avail);
942 rc = iscsi_tcp_segment_recv(tcp_conn, segment, ptr, avail);
946 if (segment->total_copied >= segment->total_size) {
947 skb_abort_seq_read(&seq);
953 *status = ISCSI_TCP_SEGMENT_DONE;
954 debug_tcp("segment done\n");
955 rc = segment->done(tcp_conn, segment);
957 *status = ISCSI_TCP_CONN_ERR;
958 debug_tcp("Error receiving PDU, errno=%d\n", rc);
959 iscsi_conn_failure(conn, rc);
962 /* The done() functions sets up the next segment. */
965 conn->rxdata_octets += consumed;
968 EXPORT_SYMBOL_GPL(iscsi_tcp_recv_skb);
971 * iscsi_tcp_recv - TCP receive in sendfile fashion
972 * @rd_desc: read descriptor
973 * @skb: socket buffer
974 * @offset: offset in skb
975 * @len: skb->len - offset
978 iscsi_tcp_recv(read_descriptor_t *rd_desc, struct sk_buff *skb,
979 unsigned int offset, size_t len)
981 struct iscsi_conn *conn = rd_desc->arg.data;
982 unsigned int consumed, total_consumed = 0;
985 debug_tcp("in %d bytes\n", skb->len - offset);
989 consumed = iscsi_tcp_recv_skb(conn, skb, offset, 0, &status);
991 total_consumed += consumed;
992 } while (consumed != 0 && status != ISCSI_TCP_SKB_DONE);
994 debug_tcp("read %d bytes status %d\n", skb->len - offset, status);
995 return total_consumed;
999 iscsi_tcp_data_ready(struct sock *sk, int flag)
1001 struct iscsi_conn *conn = sk->sk_user_data;
1002 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1003 read_descriptor_t rd_desc;
1005 read_lock(&sk->sk_callback_lock);
1008 * Use rd_desc to pass 'conn' to iscsi_tcp_recv.
1009 * We set count to 1 because we want the network layer to
1010 * hand us all the skbs that are available. iscsi_tcp_recv
1011 * handled pdus that cross buffers or pdus that still need data.
1013 rd_desc.arg.data = conn;
1015 tcp_read_sock(sk, &rd_desc, iscsi_tcp_recv);
1017 read_unlock(&sk->sk_callback_lock);
1019 /* If we had to (atomically) map a highmem page,
1021 iscsi_tcp_segment_unmap(&tcp_conn->in.segment);
1025 iscsi_tcp_state_change(struct sock *sk)
1027 struct iscsi_tcp_conn *tcp_conn;
1028 struct iscsi_conn *conn;
1029 struct iscsi_session *session;
1030 void (*old_state_change)(struct sock *);
1032 read_lock(&sk->sk_callback_lock);
1034 conn = (struct iscsi_conn*)sk->sk_user_data;
1035 session = conn->session;
1037 if ((sk->sk_state == TCP_CLOSE_WAIT ||
1038 sk->sk_state == TCP_CLOSE) &&
1039 !atomic_read(&sk->sk_rmem_alloc)) {
1040 debug_tcp("iscsi_tcp_state_change: TCP_CLOSE|TCP_CLOSE_WAIT\n");
1041 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1044 tcp_conn = conn->dd_data;
1045 old_state_change = tcp_conn->old_state_change;
1047 read_unlock(&sk->sk_callback_lock);
1049 old_state_change(sk);
1053 * iscsi_write_space - Called when more output buffer space is available
1054 * @sk: socket space is available for
1057 iscsi_write_space(struct sock *sk)
1059 struct iscsi_conn *conn = (struct iscsi_conn*)sk->sk_user_data;
1060 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1062 tcp_conn->old_write_space(sk);
1063 debug_tcp("iscsi_write_space: cid %d\n", conn->id);
1064 scsi_queue_work(conn->session->host, &conn->xmitwork);
1068 iscsi_conn_set_callbacks(struct iscsi_conn *conn)
1070 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1071 struct sock *sk = tcp_conn->sock->sk;
1073 /* assign new callbacks */
1074 write_lock_bh(&sk->sk_callback_lock);
1075 sk->sk_user_data = conn;
1076 tcp_conn->old_data_ready = sk->sk_data_ready;
1077 tcp_conn->old_state_change = sk->sk_state_change;
1078 tcp_conn->old_write_space = sk->sk_write_space;
1079 sk->sk_data_ready = iscsi_tcp_data_ready;
1080 sk->sk_state_change = iscsi_tcp_state_change;
1081 sk->sk_write_space = iscsi_write_space;
1082 write_unlock_bh(&sk->sk_callback_lock);
1086 iscsi_conn_restore_callbacks(struct iscsi_tcp_conn *tcp_conn)
1088 struct sock *sk = tcp_conn->sock->sk;
1090 /* restore socket callbacks, see also: iscsi_conn_set_callbacks() */
1091 write_lock_bh(&sk->sk_callback_lock);
1092 sk->sk_user_data = NULL;
1093 sk->sk_data_ready = tcp_conn->old_data_ready;
1094 sk->sk_state_change = tcp_conn->old_state_change;
1095 sk->sk_write_space = tcp_conn->old_write_space;
1096 sk->sk_no_check = 0;
1097 write_unlock_bh(&sk->sk_callback_lock);
1101 * iscsi_xmit - TCP transmit
1104 iscsi_xmit(struct iscsi_conn *conn)
1106 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1107 struct iscsi_segment *segment = &tcp_conn->out.segment;
1108 unsigned int consumed = 0;
1112 rc = iscsi_tcp_xmit_segment(tcp_conn, segment);
1114 rc = ISCSI_ERR_XMIT_FAILED;
1122 if (segment->total_copied >= segment->total_size) {
1123 if (segment->done != NULL) {
1124 rc = segment->done(tcp_conn, segment);
1131 debug_tcp("xmit %d bytes\n", consumed);
1133 conn->txdata_octets += consumed;
1137 /* Transmit error. We could initiate error recovery
1139 debug_tcp("Error sending PDU, errno=%d\n", rc);
1140 iscsi_conn_failure(conn, rc);
1145 * iscsi_tcp_xmit_qlen - return the number of bytes queued for xmit
1148 iscsi_tcp_xmit_qlen(struct iscsi_conn *conn)
1150 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1151 struct iscsi_segment *segment = &tcp_conn->out.segment;
1153 return segment->total_copied - segment->total_size;
1156 static int iscsi_tcp_flush(struct iscsi_task *task)
1158 struct iscsi_conn *conn = task->conn;
1161 while (iscsi_tcp_xmit_qlen(conn)) {
1162 rc = iscsi_xmit(conn);
1173 * This is called when we're done sending the header.
1174 * Simply copy the data_segment to the send segment, and return.
1177 iscsi_tcp_send_hdr_done(struct iscsi_tcp_conn *tcp_conn,
1178 struct iscsi_segment *segment)
1180 tcp_conn->out.segment = tcp_conn->out.data_segment;
1181 debug_tcp("Header done. Next segment size %u total_size %u\n",
1182 tcp_conn->out.segment.size, tcp_conn->out.segment.total_size);
1187 iscsi_tcp_send_hdr_prep(struct iscsi_conn *conn, void *hdr, size_t hdrlen)
1189 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1191 debug_tcp("%s(%p%s)\n", __func__, tcp_conn,
1192 conn->hdrdgst_en? ", digest enabled" : "");
1194 /* Clear the data segment - needs to be filled in by the
1195 * caller using iscsi_tcp_send_data_prep() */
1196 memset(&tcp_conn->out.data_segment, 0, sizeof(struct iscsi_segment));
1198 /* If header digest is enabled, compute the CRC and
1199 * place the digest into the same buffer. We make
1200 * sure that both iscsi_tcp_task and mtask have
1203 if (conn->hdrdgst_en) {
1204 iscsi_tcp_dgst_header(&tcp_conn->tx_hash, hdr, hdrlen,
1206 hdrlen += ISCSI_DIGEST_SIZE;
1209 /* Remember header pointer for later, when we need
1210 * to decide whether there's a payload to go along
1211 * with the header. */
1212 tcp_conn->out.hdr = hdr;
1214 iscsi_segment_init_linear(&tcp_conn->out.segment, hdr, hdrlen,
1215 iscsi_tcp_send_hdr_done, NULL);
1219 * Prepare the send buffer for the payload data.
1220 * Padding and checksumming will all be taken care
1221 * of by the iscsi_segment routines.
1224 iscsi_tcp_send_data_prep(struct iscsi_conn *conn, struct scatterlist *sg,
1225 unsigned int count, unsigned int offset,
1228 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1229 struct hash_desc *tx_hash = NULL;
1230 unsigned int hdr_spec_len;
1232 debug_tcp("%s(%p, offset=%d, datalen=%d%s)\n", __func__,
1233 tcp_conn, offset, len,
1234 conn->datadgst_en? ", digest enabled" : "");
1236 /* Make sure the datalen matches what the caller
1237 said he would send. */
1238 hdr_spec_len = ntoh24(tcp_conn->out.hdr->dlength);
1239 WARN_ON(iscsi_padded(len) != iscsi_padded(hdr_spec_len));
1241 if (conn->datadgst_en)
1242 tx_hash = &tcp_conn->tx_hash;
1244 return iscsi_segment_seek_sg(&tcp_conn->out.data_segment,
1245 sg, count, offset, len,
1250 iscsi_tcp_send_linear_data_prepare(struct iscsi_conn *conn, void *data,
1253 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1254 struct hash_desc *tx_hash = NULL;
1255 unsigned int hdr_spec_len;
1257 debug_tcp("%s(%p, datalen=%d%s)\n", __func__, tcp_conn, len,
1258 conn->datadgst_en? ", digest enabled" : "");
1260 /* Make sure the datalen matches what the caller
1261 said he would send. */
1262 hdr_spec_len = ntoh24(tcp_conn->out.hdr->dlength);
1263 WARN_ON(iscsi_padded(len) != iscsi_padded(hdr_spec_len));
1265 if (conn->datadgst_en)
1266 tx_hash = &tcp_conn->tx_hash;
1268 iscsi_segment_init_linear(&tcp_conn->out.data_segment,
1269 data, len, NULL, tx_hash);
1272 static int iscsi_tcp_pdu_init(struct iscsi_task *task,
1273 unsigned int offset, unsigned int count)
1275 struct iscsi_conn *conn = task->conn;
1278 iscsi_tcp_send_hdr_prep(conn, task->hdr, task->hdr_len);
1284 iscsi_tcp_send_linear_data_prepare(conn, task->data, count);
1286 struct scsi_data_buffer *sdb = scsi_out(task->sc);
1288 err = iscsi_tcp_send_data_prep(conn, sdb->table.sgl,
1289 sdb->table.nents, offset, count);
1293 iscsi_conn_failure(conn, err);
1299 static int iscsi_tcp_pdu_alloc(struct iscsi_task *task)
1301 struct iscsi_tcp_task *tcp_task = task->dd_data;
1303 task->hdr = &tcp_task->hdr.hdrbuf;
1304 task->hdr_max = sizeof(tcp_task->hdr) - ISCSI_DIGEST_SIZE;
1309 * iscsi_tcp_task - Initialize iSCSI SCSI_READ or SCSI_WRITE commands
1310 * @conn: iscsi connection
1311 * @task: scsi command task
1314 static int iscsi_tcp_task_init(struct iscsi_task *task)
1316 struct iscsi_tcp_task *tcp_task = task->dd_data;
1317 struct iscsi_conn *conn = task->conn;
1318 struct scsi_cmnd *sc = task->sc;
1323 * mgmt tasks do not have a scatterlist since they come
1324 * in from the iscsi interface.
1326 debug_scsi("mtask deq [cid %d itt 0x%x]\n", conn->id,
1329 return conn->session->tt->init_pdu(task, 0, task->data_count);
1332 BUG_ON(__kfifo_len(tcp_task->r2tqueue));
1333 tcp_task->exp_datasn = 0;
1335 /* Prepare PDU, optionally w/ immediate data */
1336 debug_scsi("task deq [cid %d itt 0x%x imm %d unsol %d]\n",
1337 conn->id, task->itt, task->imm_count,
1338 task->unsol_r2t.data_length);
1340 err = conn->session->tt->init_pdu(task, 0, task->imm_count);
1343 task->imm_count = 0;
1347 static struct iscsi_r2t_info *iscsi_tcp_get_curr_r2t(struct iscsi_task *task)
1349 struct iscsi_session *session = task->conn->session;
1350 struct iscsi_tcp_task *tcp_task = task->dd_data;
1351 struct iscsi_r2t_info *r2t = NULL;
1353 if (iscsi_task_has_unsol_data(task))
1354 r2t = &task->unsol_r2t;
1356 spin_lock_bh(&session->lock);
1357 if (tcp_task->r2t) {
1358 r2t = tcp_task->r2t;
1359 /* Continue with this R2T? */
1360 if (r2t->data_length <= r2t->sent) {
1361 debug_scsi(" done with r2t %p\n", r2t);
1362 __kfifo_put(tcp_task->r2tpool.queue,
1363 (void *)&tcp_task->r2t,
1365 tcp_task->r2t = r2t = NULL;
1370 __kfifo_get(tcp_task->r2tqueue,
1371 (void *)&tcp_task->r2t, sizeof(void *));
1372 r2t = tcp_task->r2t;
1374 spin_unlock_bh(&session->lock);
1381 * iscsi_tcp_task_xmit - xmit normal PDU task
1382 * @task: iscsi command task
1384 * We're expected to return 0 when everything was transmitted succesfully,
1385 * -EAGAIN if there's still data in the queue, or != 0 for any other kind
1388 static int iscsi_tcp_task_xmit(struct iscsi_task *task)
1390 struct iscsi_conn *conn = task->conn;
1391 struct iscsi_session *session = conn->session;
1392 struct iscsi_r2t_info *r2t;
1396 /* Flush any pending data first. */
1397 rc = session->tt->xmit_pdu(task);
1403 if (task->hdr->itt == RESERVED_ITT)
1404 iscsi_put_task(task);
1408 /* Are we done already? */
1409 if (task->sc->sc_data_direction != DMA_TO_DEVICE)
1412 r2t = iscsi_tcp_get_curr_r2t(task);
1414 /* Waiting for more R2Ts to arrive. */
1415 debug_tcp("no R2Ts yet\n");
1419 rc = conn->session->tt->alloc_pdu(task);
1422 iscsi_prep_data_out_pdu(task, r2t, (struct iscsi_data *) task->hdr);
1424 debug_scsi("sol dout %p [dsn %d itt 0x%x doff %d dlen %d]\n",
1425 r2t, r2t->datasn - 1, task->hdr->itt,
1426 r2t->data_offset + r2t->sent, r2t->data_count);
1428 rc = conn->session->tt->init_pdu(task, r2t->data_offset + r2t->sent,
1432 r2t->sent += r2t->data_count;
1436 static struct iscsi_cls_conn *
1437 iscsi_tcp_conn_create(struct iscsi_cls_session *cls_session, uint32_t conn_idx)
1439 struct iscsi_conn *conn;
1440 struct iscsi_cls_conn *cls_conn;
1441 struct iscsi_tcp_conn *tcp_conn;
1443 cls_conn = iscsi_conn_setup(cls_session, sizeof(*tcp_conn), conn_idx);
1446 conn = cls_conn->dd_data;
1448 * due to strange issues with iser these are not set
1449 * in iscsi_conn_setup
1451 conn->max_recv_dlength = ISCSI_DEF_MAX_RECV_SEG_LEN;
1453 tcp_conn = conn->dd_data;
1454 tcp_conn->iscsi_conn = conn;
1456 tcp_conn->tx_hash.tfm = crypto_alloc_hash("crc32c", 0,
1458 tcp_conn->tx_hash.flags = 0;
1459 if (IS_ERR(tcp_conn->tx_hash.tfm))
1462 tcp_conn->rx_hash.tfm = crypto_alloc_hash("crc32c", 0,
1464 tcp_conn->rx_hash.flags = 0;
1465 if (IS_ERR(tcp_conn->rx_hash.tfm))
1471 crypto_free_hash(tcp_conn->tx_hash.tfm);
1473 iscsi_conn_printk(KERN_ERR, conn,
1474 "Could not create connection due to crc32c "
1475 "loading error. Make sure the crc32c "
1476 "module is built as a module or into the "
1478 iscsi_conn_teardown(cls_conn);
1483 iscsi_tcp_release_conn(struct iscsi_conn *conn)
1485 struct iscsi_session *session = conn->session;
1486 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1487 struct socket *sock = tcp_conn->sock;
1492 sock_hold(sock->sk);
1493 iscsi_conn_restore_callbacks(tcp_conn);
1496 spin_lock_bh(&session->lock);
1497 tcp_conn->sock = NULL;
1498 spin_unlock_bh(&session->lock);
1503 iscsi_tcp_conn_destroy(struct iscsi_cls_conn *cls_conn)
1505 struct iscsi_conn *conn = cls_conn->dd_data;
1506 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1508 iscsi_tcp_release_conn(conn);
1510 if (tcp_conn->tx_hash.tfm)
1511 crypto_free_hash(tcp_conn->tx_hash.tfm);
1512 if (tcp_conn->rx_hash.tfm)
1513 crypto_free_hash(tcp_conn->rx_hash.tfm);
1515 iscsi_conn_teardown(cls_conn);
1519 iscsi_tcp_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
1521 struct iscsi_conn *conn = cls_conn->dd_data;
1522 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1524 /* userspace may have goofed up and not bound us */
1525 if (!tcp_conn->sock)
1528 * Make sure our recv side is stopped.
1529 * Older tools called conn stop before ep_disconnect
1530 * so IO could still be coming in.
1532 write_lock_bh(&tcp_conn->sock->sk->sk_callback_lock);
1533 set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
1534 write_unlock_bh(&tcp_conn->sock->sk->sk_callback_lock);
1536 iscsi_conn_stop(cls_conn, flag);
1537 iscsi_tcp_release_conn(conn);
1540 static int iscsi_tcp_get_addr(struct iscsi_conn *conn, struct socket *sock,
1541 char *buf, int *port,
1542 int (*getname)(struct socket *, struct sockaddr *,
1545 struct sockaddr_storage *addr;
1546 struct sockaddr_in6 *sin6;
1547 struct sockaddr_in *sin;
1550 addr = kmalloc(sizeof(*addr), GFP_KERNEL);
1554 if (getname(sock, (struct sockaddr *) addr, &len)) {
1559 switch (addr->ss_family) {
1561 sin = (struct sockaddr_in *)addr;
1562 spin_lock_bh(&conn->session->lock);
1563 sprintf(buf, "%pI4", &sin->sin_addr.s_addr);
1564 *port = be16_to_cpu(sin->sin_port);
1565 spin_unlock_bh(&conn->session->lock);
1568 sin6 = (struct sockaddr_in6 *)addr;
1569 spin_lock_bh(&conn->session->lock);
1570 sprintf(buf, "%pI6", &sin6->sin6_addr);
1571 *port = be16_to_cpu(sin6->sin6_port);
1572 spin_unlock_bh(&conn->session->lock);
1581 iscsi_tcp_conn_bind(struct iscsi_cls_session *cls_session,
1582 struct iscsi_cls_conn *cls_conn, uint64_t transport_eph,
1585 struct Scsi_Host *shost = iscsi_session_to_shost(cls_session);
1586 struct iscsi_host *ihost = shost_priv(shost);
1587 struct iscsi_conn *conn = cls_conn->dd_data;
1588 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1590 struct socket *sock;
1593 /* lookup for existing socket */
1594 sock = sockfd_lookup((int)transport_eph, &err);
1596 iscsi_conn_printk(KERN_ERR, conn,
1597 "sockfd_lookup failed %d\n", err);
1601 * copy these values now because if we drop the session
1602 * userspace may still want to query the values since we will
1603 * be using them for the reconnect
1605 err = iscsi_tcp_get_addr(conn, sock, conn->portal_address,
1606 &conn->portal_port, kernel_getpeername);
1610 err = iscsi_tcp_get_addr(conn, sock, ihost->local_address,
1611 &ihost->local_port, kernel_getsockname);
1615 err = iscsi_conn_bind(cls_session, cls_conn, is_leading);
1619 /* bind iSCSI connection and socket */
1620 tcp_conn->sock = sock;
1622 /* setup Socket parameters */
1625 sk->sk_sndtimeo = 15 * HZ; /* FIXME: make it configurable */
1626 sk->sk_allocation = GFP_ATOMIC;
1628 iscsi_conn_set_callbacks(conn);
1629 tcp_conn->sendpage = tcp_conn->sock->ops->sendpage;
1631 * set receive state machine into initial state
1633 iscsi_tcp_hdr_recv_prep(tcp_conn);
1642 iscsi_r2tpool_alloc(struct iscsi_session *session)
1648 * initialize per-task: R2T pool and xmit queue
1650 for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
1651 struct iscsi_task *task = session->cmds[cmd_i];
1652 struct iscsi_tcp_task *tcp_task = task->dd_data;
1655 * pre-allocated x2 as much r2ts to handle race when
1656 * target acks DataOut faster than we data_xmit() queues
1657 * could replenish r2tqueue.
1661 if (iscsi_pool_init(&tcp_task->r2tpool,
1662 session->max_r2t * 2, NULL,
1663 sizeof(struct iscsi_r2t_info))) {
1664 goto r2t_alloc_fail;
1667 /* R2T xmit queue */
1668 tcp_task->r2tqueue = kfifo_alloc(
1669 session->max_r2t * 4 * sizeof(void*), GFP_KERNEL, NULL);
1670 if (tcp_task->r2tqueue == ERR_PTR(-ENOMEM)) {
1671 iscsi_pool_free(&tcp_task->r2tpool);
1672 goto r2t_alloc_fail;
1679 for (i = 0; i < cmd_i; i++) {
1680 struct iscsi_task *task = session->cmds[i];
1681 struct iscsi_tcp_task *tcp_task = task->dd_data;
1683 kfifo_free(tcp_task->r2tqueue);
1684 iscsi_pool_free(&tcp_task->r2tpool);
1690 iscsi_r2tpool_free(struct iscsi_session *session)
1694 for (i = 0; i < session->cmds_max; i++) {
1695 struct iscsi_task *task = session->cmds[i];
1696 struct iscsi_tcp_task *tcp_task = task->dd_data;
1698 kfifo_free(tcp_task->r2tqueue);
1699 iscsi_pool_free(&tcp_task->r2tpool);
1704 iscsi_conn_set_param(struct iscsi_cls_conn *cls_conn, enum iscsi_param param,
1705 char *buf, int buflen)
1707 struct iscsi_conn *conn = cls_conn->dd_data;
1708 struct iscsi_session *session = conn->session;
1709 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1713 case ISCSI_PARAM_HDRDGST_EN:
1714 iscsi_set_param(cls_conn, param, buf, buflen);
1716 case ISCSI_PARAM_DATADGST_EN:
1717 iscsi_set_param(cls_conn, param, buf, buflen);
1718 tcp_conn->sendpage = conn->datadgst_en ?
1719 sock_no_sendpage : tcp_conn->sock->ops->sendpage;
1721 case ISCSI_PARAM_MAX_R2T:
1722 sscanf(buf, "%d", &value);
1723 if (value <= 0 || !is_power_of_2(value))
1725 if (session->max_r2t == value)
1727 iscsi_r2tpool_free(session);
1728 iscsi_set_param(cls_conn, param, buf, buflen);
1729 if (iscsi_r2tpool_alloc(session))
1733 return iscsi_set_param(cls_conn, param, buf, buflen);
1740 iscsi_tcp_conn_get_param(struct iscsi_cls_conn *cls_conn,
1741 enum iscsi_param param, char *buf)
1743 struct iscsi_conn *conn = cls_conn->dd_data;
1747 case ISCSI_PARAM_CONN_PORT:
1748 spin_lock_bh(&conn->session->lock);
1749 len = sprintf(buf, "%hu\n", conn->portal_port);
1750 spin_unlock_bh(&conn->session->lock);
1752 case ISCSI_PARAM_CONN_ADDRESS:
1753 spin_lock_bh(&conn->session->lock);
1754 len = sprintf(buf, "%s\n", conn->portal_address);
1755 spin_unlock_bh(&conn->session->lock);
1758 return iscsi_conn_get_param(cls_conn, param, buf);
1765 iscsi_conn_get_stats(struct iscsi_cls_conn *cls_conn, struct iscsi_stats *stats)
1767 struct iscsi_conn *conn = cls_conn->dd_data;
1768 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1770 stats->txdata_octets = conn->txdata_octets;
1771 stats->rxdata_octets = conn->rxdata_octets;
1772 stats->scsicmd_pdus = conn->scsicmd_pdus_cnt;
1773 stats->dataout_pdus = conn->dataout_pdus_cnt;
1774 stats->scsirsp_pdus = conn->scsirsp_pdus_cnt;
1775 stats->datain_pdus = conn->datain_pdus_cnt;
1776 stats->r2t_pdus = conn->r2t_pdus_cnt;
1777 stats->tmfcmd_pdus = conn->tmfcmd_pdus_cnt;
1778 stats->tmfrsp_pdus = conn->tmfrsp_pdus_cnt;
1779 stats->custom_length = 3;
1780 strcpy(stats->custom[0].desc, "tx_sendpage_failures");
1781 stats->custom[0].value = tcp_conn->sendpage_failures_cnt;
1782 strcpy(stats->custom[1].desc, "rx_discontiguous_hdr");
1783 stats->custom[1].value = tcp_conn->discontiguous_hdr_cnt;
1784 strcpy(stats->custom[2].desc, "eh_abort_cnt");
1785 stats->custom[2].value = conn->eh_abort_cnt;
1788 static struct iscsi_cls_session *
1789 iscsi_tcp_session_create(struct iscsi_endpoint *ep, uint16_t cmds_max,
1790 uint16_t qdepth, uint32_t initial_cmdsn,
1793 struct iscsi_cls_session *cls_session;
1794 struct iscsi_session *session;
1795 struct Scsi_Host *shost;
1798 printk(KERN_ERR "iscsi_tcp: invalid ep %p.\n", ep);
1802 shost = iscsi_host_alloc(&iscsi_sht, 0, qdepth);
1805 shost->transportt = iscsi_tcp_scsi_transport;
1806 shost->max_lun = iscsi_max_lun;
1808 shost->max_channel = 0;
1809 shost->max_cmd_len = SCSI_MAX_VARLEN_CDB_SIZE;
1811 if (iscsi_host_add(shost, NULL))
1813 *hostno = shost->host_no;
1815 cls_session = iscsi_session_setup(&iscsi_tcp_transport, shost, cmds_max,
1816 sizeof(struct iscsi_tcp_task),
1820 session = cls_session->dd_data;
1822 shost->can_queue = session->scsi_cmds_max;
1823 if (iscsi_r2tpool_alloc(session))
1824 goto remove_session;
1828 iscsi_session_teardown(cls_session);
1830 iscsi_host_remove(shost);
1832 iscsi_host_free(shost);
1836 static void iscsi_tcp_session_destroy(struct iscsi_cls_session *cls_session)
1838 struct Scsi_Host *shost = iscsi_session_to_shost(cls_session);
1840 iscsi_r2tpool_free(cls_session->dd_data);
1841 iscsi_session_teardown(cls_session);
1843 iscsi_host_remove(shost);
1844 iscsi_host_free(shost);
1847 static int iscsi_tcp_slave_configure(struct scsi_device *sdev)
1849 blk_queue_bounce_limit(sdev->request_queue, BLK_BOUNCE_ANY);
1850 blk_queue_dma_alignment(sdev->request_queue, 0);
1854 static struct scsi_host_template iscsi_sht = {
1855 .module = THIS_MODULE,
1856 .name = "iSCSI Initiator over TCP/IP",
1857 .queuecommand = iscsi_queuecommand,
1858 .change_queue_depth = iscsi_change_queue_depth,
1859 .can_queue = ISCSI_DEF_XMIT_CMDS_MAX - 1,
1860 .sg_tablesize = 4096,
1861 .max_sectors = 0xFFFF,
1862 .cmd_per_lun = ISCSI_DEF_CMD_PER_LUN,
1863 .eh_abort_handler = iscsi_eh_abort,
1864 .eh_device_reset_handler= iscsi_eh_device_reset,
1865 .eh_target_reset_handler= iscsi_eh_target_reset,
1866 .use_clustering = DISABLE_CLUSTERING,
1867 .slave_configure = iscsi_tcp_slave_configure,
1868 .proc_name = "iscsi_tcp",
1872 static struct iscsi_transport iscsi_tcp_transport = {
1873 .owner = THIS_MODULE,
1875 .caps = CAP_RECOVERY_L0 | CAP_MULTI_R2T | CAP_HDRDGST
1877 .param_mask = ISCSI_MAX_RECV_DLENGTH |
1878 ISCSI_MAX_XMIT_DLENGTH |
1881 ISCSI_INITIAL_R2T_EN |
1886 ISCSI_PDU_INORDER_EN |
1887 ISCSI_DATASEQ_INORDER_EN |
1890 ISCSI_CONN_ADDRESS |
1892 ISCSI_PERSISTENT_PORT |
1893 ISCSI_PERSISTENT_ADDRESS |
1894 ISCSI_TARGET_NAME | ISCSI_TPGT |
1895 ISCSI_USERNAME | ISCSI_PASSWORD |
1896 ISCSI_USERNAME_IN | ISCSI_PASSWORD_IN |
1897 ISCSI_FAST_ABORT | ISCSI_ABORT_TMO |
1898 ISCSI_LU_RESET_TMO |
1899 ISCSI_PING_TMO | ISCSI_RECV_TMO |
1900 ISCSI_IFACE_NAME | ISCSI_INITIATOR_NAME,
1901 .host_param_mask = ISCSI_HOST_HWADDRESS | ISCSI_HOST_IPADDRESS |
1902 ISCSI_HOST_INITIATOR_NAME |
1903 ISCSI_HOST_NETDEV_NAME,
1904 /* session management */
1905 .create_session = iscsi_tcp_session_create,
1906 .destroy_session = iscsi_tcp_session_destroy,
1907 /* connection management */
1908 .create_conn = iscsi_tcp_conn_create,
1909 .bind_conn = iscsi_tcp_conn_bind,
1910 .destroy_conn = iscsi_tcp_conn_destroy,
1911 .set_param = iscsi_conn_set_param,
1912 .get_conn_param = iscsi_tcp_conn_get_param,
1913 .get_session_param = iscsi_session_get_param,
1914 .start_conn = iscsi_conn_start,
1915 .stop_conn = iscsi_tcp_conn_stop,
1916 /* iscsi host params */
1917 .get_host_param = iscsi_host_get_param,
1918 .set_host_param = iscsi_host_set_param,
1920 .send_pdu = iscsi_conn_send_pdu,
1921 .get_stats = iscsi_conn_get_stats,
1922 /* iscsi task/cmd helpers */
1923 .init_task = iscsi_tcp_task_init,
1924 .xmit_task = iscsi_tcp_task_xmit,
1925 .cleanup_task = iscsi_tcp_cleanup_task,
1926 /* low level pdu helpers */
1927 .xmit_pdu = iscsi_tcp_flush,
1928 .init_pdu = iscsi_tcp_pdu_init,
1929 .alloc_pdu = iscsi_tcp_pdu_alloc,
1931 .session_recovery_timedout = iscsi_session_recovery_timedout,
1935 iscsi_tcp_init(void)
1937 if (iscsi_max_lun < 1) {
1938 printk(KERN_ERR "iscsi_tcp: Invalid max_lun value of %u\n",
1943 iscsi_tcp_scsi_transport = iscsi_register_transport(
1944 &iscsi_tcp_transport);
1945 if (!iscsi_tcp_scsi_transport)
1952 iscsi_tcp_exit(void)
1954 iscsi_unregister_transport(&iscsi_tcp_transport);
1957 module_init(iscsi_tcp_init);
1958 module_exit(iscsi_tcp_exit);