xref: /freebsd/sys/dev/iscsi/icl_soft.c (revision 148a8da8)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2012 The FreeBSD Foundation
5  * All rights reserved.
6  *
7  * This software was developed by Edward Tomasz Napierala under sponsorship
8  * from the FreeBSD Foundation.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  *
31  */
32 
33 /*
34  * Software implementation of iSCSI Common Layer kobj(9) interface.
35  */
36 
37 #include <sys/cdefs.h>
38 __FBSDID("$FreeBSD$");
39 
40 #include <sys/param.h>
41 #include <sys/capsicum.h>
42 #include <sys/condvar.h>
43 #include <sys/conf.h>
44 #include <sys/file.h>
45 #include <sys/kernel.h>
46 #include <sys/kthread.h>
47 #include <sys/lock.h>
48 #include <sys/mbuf.h>
49 #include <sys/mutex.h>
50 #include <sys/module.h>
51 #include <sys/protosw.h>
52 #include <sys/socket.h>
53 #include <sys/socketvar.h>
54 #include <sys/sysctl.h>
55 #include <sys/systm.h>
56 #include <sys/sx.h>
57 #include <sys/uio.h>
58 #include <vm/uma.h>
59 #include <netinet/in.h>
60 #include <netinet/tcp.h>
61 
62 #include <dev/iscsi/icl.h>
63 #include <dev/iscsi/iscsi_proto.h>
64 #include <icl_conn_if.h>
65 
66 static int coalesce = 1;
67 SYSCTL_INT(_kern_icl, OID_AUTO, coalesce, CTLFLAG_RWTUN,
68     &coalesce, 0, "Try to coalesce PDUs before sending");
69 static int partial_receive_len = 128 * 1024;
70 SYSCTL_INT(_kern_icl, OID_AUTO, partial_receive_len, CTLFLAG_RWTUN,
71     &partial_receive_len, 0, "Minimum read size for partially received "
72     "data segment");
73 static int sendspace = 1048576;
74 SYSCTL_INT(_kern_icl, OID_AUTO, sendspace, CTLFLAG_RWTUN,
75     &sendspace, 0, "Default send socket buffer size");
76 static int recvspace = 1048576;
77 SYSCTL_INT(_kern_icl, OID_AUTO, recvspace, CTLFLAG_RWTUN,
78     &recvspace, 0, "Default receive socket buffer size");
79 
80 static MALLOC_DEFINE(M_ICL_SOFT, "icl_soft", "iSCSI software backend");
81 static uma_zone_t icl_pdu_zone;
82 
83 static volatile u_int	icl_ncons;
84 
85 #define ICL_CONN_LOCK(X)		mtx_lock(X->ic_lock)
86 #define ICL_CONN_UNLOCK(X)		mtx_unlock(X->ic_lock)
87 #define ICL_CONN_LOCK_ASSERT(X)		mtx_assert(X->ic_lock, MA_OWNED)
88 #define ICL_CONN_LOCK_ASSERT_NOT(X)	mtx_assert(X->ic_lock, MA_NOTOWNED)
89 
90 STAILQ_HEAD(icl_pdu_stailq, icl_pdu);
91 
92 static icl_conn_new_pdu_t	icl_soft_conn_new_pdu;
93 static icl_conn_pdu_free_t	icl_soft_conn_pdu_free;
94 static icl_conn_pdu_data_segment_length_t
95 				    icl_soft_conn_pdu_data_segment_length;
96 static icl_conn_pdu_append_data_t	icl_soft_conn_pdu_append_data;
97 static icl_conn_pdu_get_data_t	icl_soft_conn_pdu_get_data;
98 static icl_conn_pdu_queue_t	icl_soft_conn_pdu_queue;
99 static icl_conn_handoff_t	icl_soft_conn_handoff;
100 static icl_conn_free_t		icl_soft_conn_free;
101 static icl_conn_close_t		icl_soft_conn_close;
102 static icl_conn_task_setup_t	icl_soft_conn_task_setup;
103 static icl_conn_task_done_t	icl_soft_conn_task_done;
104 static icl_conn_transfer_setup_t	icl_soft_conn_transfer_setup;
105 static icl_conn_transfer_done_t	icl_soft_conn_transfer_done;
106 #ifdef ICL_KERNEL_PROXY
107 static icl_conn_connect_t	icl_soft_conn_connect;
108 #endif
109 
110 static kobj_method_t icl_soft_methods[] = {
111 	KOBJMETHOD(icl_conn_new_pdu, icl_soft_conn_new_pdu),
112 	KOBJMETHOD(icl_conn_pdu_free, icl_soft_conn_pdu_free),
113 	KOBJMETHOD(icl_conn_pdu_data_segment_length,
114 	    icl_soft_conn_pdu_data_segment_length),
115 	KOBJMETHOD(icl_conn_pdu_append_data, icl_soft_conn_pdu_append_data),
116 	KOBJMETHOD(icl_conn_pdu_get_data, icl_soft_conn_pdu_get_data),
117 	KOBJMETHOD(icl_conn_pdu_queue, icl_soft_conn_pdu_queue),
118 	KOBJMETHOD(icl_conn_handoff, icl_soft_conn_handoff),
119 	KOBJMETHOD(icl_conn_free, icl_soft_conn_free),
120 	KOBJMETHOD(icl_conn_close, icl_soft_conn_close),
121 	KOBJMETHOD(icl_conn_task_setup, icl_soft_conn_task_setup),
122 	KOBJMETHOD(icl_conn_task_done, icl_soft_conn_task_done),
123 	KOBJMETHOD(icl_conn_transfer_setup, icl_soft_conn_transfer_setup),
124 	KOBJMETHOD(icl_conn_transfer_done, icl_soft_conn_transfer_done),
125 #ifdef ICL_KERNEL_PROXY
126 	KOBJMETHOD(icl_conn_connect, icl_soft_conn_connect),
127 #endif
128 	{ 0, 0 }
129 };
130 
131 DEFINE_CLASS(icl_soft, icl_soft_methods, sizeof(struct icl_conn));
132 
133 static void
134 icl_conn_fail(struct icl_conn *ic)
135 {
136 	if (ic->ic_socket == NULL)
137 		return;
138 
139 	/*
140 	 * XXX
141 	 */
142 	ic->ic_socket->so_error = EDOOFUS;
143 	(ic->ic_error)(ic);
144 }
145 
146 static struct mbuf *
147 icl_conn_receive(struct icl_conn *ic, size_t len)
148 {
149 	struct uio uio;
150 	struct socket *so;
151 	struct mbuf *m;
152 	int error, flags;
153 
154 	so = ic->ic_socket;
155 
156 	memset(&uio, 0, sizeof(uio));
157 	uio.uio_resid = len;
158 
159 	flags = MSG_DONTWAIT;
160 	error = soreceive(so, NULL, &uio, &m, NULL, &flags);
161 	if (error != 0) {
162 		ICL_DEBUG("soreceive error %d", error);
163 		return (NULL);
164 	}
165 	if (uio.uio_resid != 0) {
166 		m_freem(m);
167 		ICL_DEBUG("short read");
168 		return (NULL);
169 	}
170 
171 	return (m);
172 }
173 
174 static int
175 icl_conn_receive_buf(struct icl_conn *ic, void *buf, size_t len)
176 {
177 	struct iovec iov[1];
178 	struct uio uio;
179 	struct socket *so;
180 	int error, flags;
181 
182 	so = ic->ic_socket;
183 
184 	memset(&uio, 0, sizeof(uio));
185 	iov[0].iov_base = buf;
186 	iov[0].iov_len = len;
187 	uio.uio_iov = iov;
188 	uio.uio_iovcnt = 1;
189 	uio.uio_offset = 0;
190 	uio.uio_resid = len;
191 	uio.uio_segflg = UIO_SYSSPACE;
192 	uio.uio_rw = UIO_READ;
193 
194 	flags = MSG_DONTWAIT;
195 	error = soreceive(so, NULL, &uio, NULL, NULL, &flags);
196 	if (error != 0) {
197 		ICL_DEBUG("soreceive error %d", error);
198 		return (-1);
199 	}
200 	if (uio.uio_resid != 0) {
201 		ICL_DEBUG("short read");
202 		return (-1);
203 	}
204 
205 	return (0);
206 }
207 
208 static void
209 icl_soft_conn_pdu_free(struct icl_conn *ic, struct icl_pdu *ip)
210 {
211 
212 	m_freem(ip->ip_bhs_mbuf);
213 	m_freem(ip->ip_ahs_mbuf);
214 	m_freem(ip->ip_data_mbuf);
215 	uma_zfree(icl_pdu_zone, ip);
216 #ifdef DIAGNOSTIC
217 	refcount_release(&ic->ic_outstanding_pdus);
218 #endif
219 }
220 
221 /*
222  * Allocate icl_pdu with empty BHS to fill up by the caller.
223  */
224 struct icl_pdu *
225 icl_soft_conn_new_pdu(struct icl_conn *ic, int flags)
226 {
227 	struct icl_pdu *ip;
228 
229 #ifdef DIAGNOSTIC
230 	refcount_acquire(&ic->ic_outstanding_pdus);
231 #endif
232 	ip = uma_zalloc(icl_pdu_zone, flags | M_ZERO);
233 	if (ip == NULL) {
234 		ICL_WARN("failed to allocate %zd bytes", sizeof(*ip));
235 #ifdef DIAGNOSTIC
236 		refcount_release(&ic->ic_outstanding_pdus);
237 #endif
238 		return (NULL);
239 	}
240 	ip->ip_conn = ic;
241 
242 	CTASSERT(sizeof(struct iscsi_bhs) <= MHLEN);
243 	ip->ip_bhs_mbuf = m_gethdr(flags, MT_DATA);
244 	if (ip->ip_bhs_mbuf == NULL) {
245 		ICL_WARN("failed to allocate BHS mbuf");
246 		icl_soft_conn_pdu_free(ic, ip);
247 		return (NULL);
248 	}
249 	ip->ip_bhs = mtod(ip->ip_bhs_mbuf, struct iscsi_bhs *);
250 	memset(ip->ip_bhs, 0, sizeof(struct iscsi_bhs));
251 	ip->ip_bhs_mbuf->m_len = sizeof(struct iscsi_bhs);
252 
253 	return (ip);
254 }
255 
256 static int
257 icl_pdu_ahs_length(const struct icl_pdu *request)
258 {
259 
260 	return (request->ip_bhs->bhs_total_ahs_len * 4);
261 }
262 
263 static size_t
264 icl_pdu_data_segment_length(const struct icl_pdu *request)
265 {
266 	uint32_t len = 0;
267 
268 	len += request->ip_bhs->bhs_data_segment_len[0];
269 	len <<= 8;
270 	len += request->ip_bhs->bhs_data_segment_len[1];
271 	len <<= 8;
272 	len += request->ip_bhs->bhs_data_segment_len[2];
273 
274 	return (len);
275 }
276 
277 size_t
278 icl_soft_conn_pdu_data_segment_length(struct icl_conn *ic,
279     const struct icl_pdu *request)
280 {
281 
282 	return (icl_pdu_data_segment_length(request));
283 }
284 
285 static void
286 icl_pdu_set_data_segment_length(struct icl_pdu *response, uint32_t len)
287 {
288 
289 	response->ip_bhs->bhs_data_segment_len[2] = len;
290 	response->ip_bhs->bhs_data_segment_len[1] = len >> 8;
291 	response->ip_bhs->bhs_data_segment_len[0] = len >> 16;
292 }
293 
294 static size_t
295 icl_pdu_padding(const struct icl_pdu *ip)
296 {
297 
298 	if ((ip->ip_data_len % 4) != 0)
299 		return (4 - (ip->ip_data_len % 4));
300 
301 	return (0);
302 }
303 
304 static size_t
305 icl_pdu_size(const struct icl_pdu *response)
306 {
307 	size_t len;
308 
309 	KASSERT(response->ip_ahs_len == 0, ("responding with AHS"));
310 
311 	len = sizeof(struct iscsi_bhs) + response->ip_data_len +
312 	    icl_pdu_padding(response);
313 	if (response->ip_conn->ic_header_crc32c)
314 		len += ISCSI_HEADER_DIGEST_SIZE;
315 	if (response->ip_data_len != 0 && response->ip_conn->ic_data_crc32c)
316 		len += ISCSI_DATA_DIGEST_SIZE;
317 
318 	return (len);
319 }
320 
321 static int
322 icl_pdu_receive_bhs(struct icl_pdu *request, size_t *availablep)
323 {
324 
325 	if (icl_conn_receive_buf(request->ip_conn,
326 	    request->ip_bhs, sizeof(struct iscsi_bhs))) {
327 		ICL_DEBUG("failed to receive BHS");
328 		return (-1);
329 	}
330 
331 	*availablep -= sizeof(struct iscsi_bhs);
332 	return (0);
333 }
334 
335 static int
336 icl_pdu_receive_ahs(struct icl_pdu *request, size_t *availablep)
337 {
338 
339 	request->ip_ahs_len = icl_pdu_ahs_length(request);
340 	if (request->ip_ahs_len == 0)
341 		return (0);
342 
343 	request->ip_ahs_mbuf = icl_conn_receive(request->ip_conn,
344 	    request->ip_ahs_len);
345 	if (request->ip_ahs_mbuf == NULL) {
346 		ICL_DEBUG("failed to receive AHS");
347 		return (-1);
348 	}
349 
350 	*availablep -= request->ip_ahs_len;
351 	return (0);
352 }
353 
354 static uint32_t
355 icl_mbuf_to_crc32c(const struct mbuf *m0)
356 {
357 	uint32_t digest = 0xffffffff;
358 	const struct mbuf *m;
359 
360 	for (m = m0; m != NULL; m = m->m_next)
361 		digest = calculate_crc32c(digest,
362 		    mtod(m, const void *), m->m_len);
363 
364 	digest = digest ^ 0xffffffff;
365 
366 	return (digest);
367 }
368 
369 static int
370 icl_pdu_check_header_digest(struct icl_pdu *request, size_t *availablep)
371 {
372 	uint32_t received_digest, valid_digest;
373 
374 	if (request->ip_conn->ic_header_crc32c == false)
375 		return (0);
376 
377 	CTASSERT(sizeof(received_digest) == ISCSI_HEADER_DIGEST_SIZE);
378 	if (icl_conn_receive_buf(request->ip_conn,
379 	    &received_digest, ISCSI_HEADER_DIGEST_SIZE)) {
380 		ICL_DEBUG("failed to receive header digest");
381 		return (-1);
382 	}
383 	*availablep -= ISCSI_HEADER_DIGEST_SIZE;
384 
385 	/* Temporary attach AHS to BHS to calculate header digest. */
386 	request->ip_bhs_mbuf->m_next = request->ip_ahs_mbuf;
387 	valid_digest = icl_mbuf_to_crc32c(request->ip_bhs_mbuf);
388 	request->ip_bhs_mbuf->m_next = NULL;
389 	if (received_digest != valid_digest) {
390 		ICL_WARN("header digest check failed; got 0x%x, "
391 		    "should be 0x%x", received_digest, valid_digest);
392 		return (-1);
393 	}
394 
395 	return (0);
396 }
397 
398 /*
399  * Return the number of bytes that should be waiting in the receive socket
400  * before icl_pdu_receive_data_segment() gets called.
401  */
402 static size_t
403 icl_pdu_data_segment_receive_len(const struct icl_pdu *request)
404 {
405 	size_t len;
406 
407 	len = icl_pdu_data_segment_length(request);
408 	if (len == 0)
409 		return (0);
410 
411 	/*
412 	 * Account for the parts of data segment already read from
413 	 * the socket buffer.
414 	 */
415 	KASSERT(len > request->ip_data_len, ("len <= request->ip_data_len"));
416 	len -= request->ip_data_len;
417 
418 	/*
419 	 * Don't always wait for the full data segment to be delivered
420 	 * to the socket; this might badly affect performance due to
421 	 * TCP window scaling.
422 	 */
423 	if (len > partial_receive_len) {
424 #if 0
425 		ICL_DEBUG("need %zd bytes of data, limiting to %zd",
426 		    len, partial_receive_len));
427 #endif
428 		len = partial_receive_len;
429 
430 		return (len);
431 	}
432 
433 	/*
434 	 * Account for padding.  Note that due to the way code is written,
435 	 * the icl_pdu_receive_data_segment() must always receive padding
436 	 * along with the last part of data segment, because it would be
437 	 * impossible to tell whether we've already received the full data
438 	 * segment including padding, or without it.
439 	 */
440 	if ((len % 4) != 0)
441 		len += 4 - (len % 4);
442 
443 #if 0
444 	ICL_DEBUG("need %zd bytes of data", len));
445 #endif
446 
447 	return (len);
448 }
449 
450 static int
451 icl_pdu_receive_data_segment(struct icl_pdu *request,
452     size_t *availablep, bool *more_neededp)
453 {
454 	struct icl_conn *ic;
455 	size_t len, padding = 0;
456 	struct mbuf *m;
457 
458 	ic = request->ip_conn;
459 
460 	*more_neededp = false;
461 	ic->ic_receive_len = 0;
462 
463 	len = icl_pdu_data_segment_length(request);
464 	if (len == 0)
465 		return (0);
466 
467 	if ((len % 4) != 0)
468 		padding = 4 - (len % 4);
469 
470 	/*
471 	 * Account for already received parts of data segment.
472 	 */
473 	KASSERT(len > request->ip_data_len, ("len <= request->ip_data_len"));
474 	len -= request->ip_data_len;
475 
476 	if (len + padding > *availablep) {
477 		/*
478 		 * Not enough data in the socket buffer.  Receive as much
479 		 * as we can.  Don't receive padding, since, obviously, it's
480 		 * not the end of data segment yet.
481 		 */
482 #if 0
483 		ICL_DEBUG("limited from %zd to %zd",
484 		    len + padding, *availablep - padding));
485 #endif
486 		len = *availablep - padding;
487 		*more_neededp = true;
488 		padding = 0;
489 	}
490 
491 	/*
492 	 * Must not try to receive padding without at least one byte
493 	 * of actual data segment.
494 	 */
495 	if (len > 0) {
496 		m = icl_conn_receive(request->ip_conn, len + padding);
497 		if (m == NULL) {
498 			ICL_DEBUG("failed to receive data segment");
499 			return (-1);
500 		}
501 
502 		if (request->ip_data_mbuf == NULL)
503 			request->ip_data_mbuf = m;
504 		else
505 			m_cat(request->ip_data_mbuf, m);
506 
507 		request->ip_data_len += len;
508 		*availablep -= len + padding;
509 	} else
510 		ICL_DEBUG("len 0");
511 
512 	if (*more_neededp)
513 		ic->ic_receive_len =
514 		    icl_pdu_data_segment_receive_len(request);
515 
516 	return (0);
517 }
518 
519 static int
520 icl_pdu_check_data_digest(struct icl_pdu *request, size_t *availablep)
521 {
522 	uint32_t received_digest, valid_digest;
523 
524 	if (request->ip_conn->ic_data_crc32c == false)
525 		return (0);
526 
527 	if (request->ip_data_len == 0)
528 		return (0);
529 
530 	CTASSERT(sizeof(received_digest) == ISCSI_DATA_DIGEST_SIZE);
531 	if (icl_conn_receive_buf(request->ip_conn,
532 	    &received_digest, ISCSI_DATA_DIGEST_SIZE)) {
533 		ICL_DEBUG("failed to receive data digest");
534 		return (-1);
535 	}
536 	*availablep -= ISCSI_DATA_DIGEST_SIZE;
537 
538 	/*
539 	 * Note that ip_data_mbuf also contains padding; since digest
540 	 * calculation is supposed to include that, we iterate over
541 	 * the entire ip_data_mbuf chain, not just ip_data_len bytes of it.
542 	 */
543 	valid_digest = icl_mbuf_to_crc32c(request->ip_data_mbuf);
544 	if (received_digest != valid_digest) {
545 		ICL_WARN("data digest check failed; got 0x%x, "
546 		    "should be 0x%x", received_digest, valid_digest);
547 		return (-1);
548 	}
549 
550 	return (0);
551 }
552 
553 /*
554  * Somewhat contrary to the name, this attempts to receive only one
555  * "part" of PDU at a time; call it repeatedly until it returns non-NULL.
556  */
557 static struct icl_pdu *
558 icl_conn_receive_pdu(struct icl_conn *ic, size_t *availablep)
559 {
560 	struct icl_pdu *request;
561 	struct socket *so;
562 	size_t len;
563 	int error;
564 	bool more_needed;
565 
566 	so = ic->ic_socket;
567 
568 	if (ic->ic_receive_state == ICL_CONN_STATE_BHS) {
569 		KASSERT(ic->ic_receive_pdu == NULL,
570 		    ("ic->ic_receive_pdu != NULL"));
571 		request = icl_soft_conn_new_pdu(ic, M_NOWAIT);
572 		if (request == NULL) {
573 			ICL_DEBUG("failed to allocate PDU; "
574 			    "dropping connection");
575 			icl_conn_fail(ic);
576 			return (NULL);
577 		}
578 		ic->ic_receive_pdu = request;
579 	} else {
580 		KASSERT(ic->ic_receive_pdu != NULL,
581 		    ("ic->ic_receive_pdu == NULL"));
582 		request = ic->ic_receive_pdu;
583 	}
584 
585 	if (*availablep < ic->ic_receive_len) {
586 #if 0
587 		ICL_DEBUG("not enough data; need %zd, "
588 		    "have %zd", ic->ic_receive_len, *availablep);
589 #endif
590 		return (NULL);
591 	}
592 
593 	switch (ic->ic_receive_state) {
594 	case ICL_CONN_STATE_BHS:
595 		//ICL_DEBUG("receiving BHS");
596 		error = icl_pdu_receive_bhs(request, availablep);
597 		if (error != 0) {
598 			ICL_DEBUG("failed to receive BHS; "
599 			    "dropping connection");
600 			break;
601 		}
602 
603 		/*
604 		 * We don't enforce any limit for AHS length;
605 		 * its length is stored in 8 bit field.
606 		 */
607 
608 		len = icl_pdu_data_segment_length(request);
609 		if (len > ic->ic_max_data_segment_length) {
610 			ICL_WARN("received data segment "
611 			    "length %zd is larger than negotiated "
612 			    "MaxDataSegmentLength %zd; "
613 			    "dropping connection",
614 			    len, ic->ic_max_data_segment_length);
615 			error = EINVAL;
616 			break;
617 		}
618 
619 		ic->ic_receive_state = ICL_CONN_STATE_AHS;
620 		ic->ic_receive_len = icl_pdu_ahs_length(request);
621 		break;
622 
623 	case ICL_CONN_STATE_AHS:
624 		//ICL_DEBUG("receiving AHS");
625 		error = icl_pdu_receive_ahs(request, availablep);
626 		if (error != 0) {
627 			ICL_DEBUG("failed to receive AHS; "
628 			    "dropping connection");
629 			break;
630 		}
631 		ic->ic_receive_state = ICL_CONN_STATE_HEADER_DIGEST;
632 		if (ic->ic_header_crc32c == false)
633 			ic->ic_receive_len = 0;
634 		else
635 			ic->ic_receive_len = ISCSI_HEADER_DIGEST_SIZE;
636 		break;
637 
638 	case ICL_CONN_STATE_HEADER_DIGEST:
639 		//ICL_DEBUG("receiving header digest");
640 		error = icl_pdu_check_header_digest(request, availablep);
641 		if (error != 0) {
642 			ICL_DEBUG("header digest failed; "
643 			    "dropping connection");
644 			break;
645 		}
646 
647 		ic->ic_receive_state = ICL_CONN_STATE_DATA;
648 		ic->ic_receive_len =
649 		    icl_pdu_data_segment_receive_len(request);
650 		break;
651 
652 	case ICL_CONN_STATE_DATA:
653 		//ICL_DEBUG("receiving data segment");
654 		error = icl_pdu_receive_data_segment(request, availablep,
655 		    &more_needed);
656 		if (error != 0) {
657 			ICL_DEBUG("failed to receive data segment;"
658 			    "dropping connection");
659 			break;
660 		}
661 
662 		if (more_needed)
663 			break;
664 
665 		ic->ic_receive_state = ICL_CONN_STATE_DATA_DIGEST;
666 		if (request->ip_data_len == 0 || ic->ic_data_crc32c == false)
667 			ic->ic_receive_len = 0;
668 		else
669 			ic->ic_receive_len = ISCSI_DATA_DIGEST_SIZE;
670 		break;
671 
672 	case ICL_CONN_STATE_DATA_DIGEST:
673 		//ICL_DEBUG("receiving data digest");
674 		error = icl_pdu_check_data_digest(request, availablep);
675 		if (error != 0) {
676 			ICL_DEBUG("data digest failed; "
677 			    "dropping connection");
678 			break;
679 		}
680 
681 		/*
682 		 * We've received complete PDU; reset the receive state machine
683 		 * and return the PDU.
684 		 */
685 		ic->ic_receive_state = ICL_CONN_STATE_BHS;
686 		ic->ic_receive_len = sizeof(struct iscsi_bhs);
687 		ic->ic_receive_pdu = NULL;
688 		return (request);
689 
690 	default:
691 		panic("invalid ic_receive_state %d\n", ic->ic_receive_state);
692 	}
693 
694 	if (error != 0) {
695 		/*
696 		 * Don't free the PDU; it's pointed to by ic->ic_receive_pdu
697 		 * and will get freed in icl_soft_conn_close().
698 		 */
699 		icl_conn_fail(ic);
700 	}
701 
702 	return (NULL);
703 }
704 
705 static void
706 icl_conn_receive_pdus(struct icl_conn *ic, size_t available)
707 {
708 	struct icl_pdu *response;
709 	struct socket *so;
710 
711 	so = ic->ic_socket;
712 
713 	/*
714 	 * This can never happen; we're careful to only mess with ic->ic_socket
715 	 * pointer when the send/receive threads are not running.
716 	 */
717 	KASSERT(so != NULL, ("NULL socket"));
718 
719 	for (;;) {
720 		if (ic->ic_disconnecting)
721 			return;
722 
723 		if (so->so_error != 0) {
724 			ICL_DEBUG("connection error %d; "
725 			    "dropping connection", so->so_error);
726 			icl_conn_fail(ic);
727 			return;
728 		}
729 
730 		/*
731 		 * Loop until we have a complete PDU or there is not enough
732 		 * data in the socket buffer.
733 		 */
734 		if (available < ic->ic_receive_len) {
735 #if 0
736 			ICL_DEBUG("not enough data; have %zd, "
737 			    "need %zd", available,
738 			    ic->ic_receive_len);
739 #endif
740 			return;
741 		}
742 
743 		response = icl_conn_receive_pdu(ic, &available);
744 		if (response == NULL)
745 			continue;
746 
747 		if (response->ip_ahs_len > 0) {
748 			ICL_WARN("received PDU with unsupported "
749 			    "AHS; opcode 0x%x; dropping connection",
750 			    response->ip_bhs->bhs_opcode);
751 			icl_soft_conn_pdu_free(ic, response);
752 			icl_conn_fail(ic);
753 			return;
754 		}
755 
756 		(ic->ic_receive)(response);
757 	}
758 }
759 
760 static void
761 icl_receive_thread(void *arg)
762 {
763 	struct icl_conn *ic;
764 	size_t available;
765 	struct socket *so;
766 
767 	ic = arg;
768 	so = ic->ic_socket;
769 
770 	for (;;) {
771 		if (ic->ic_disconnecting) {
772 			//ICL_DEBUG("terminating");
773 			break;
774 		}
775 
776 		/*
777 		 * Set the low watermark, to be checked by
778 		 * soreadable() in icl_soupcall_receive()
779 		 * to avoid unnecessary wakeups until there
780 		 * is enough data received to read the PDU.
781 		 */
782 		SOCKBUF_LOCK(&so->so_rcv);
783 		available = sbavail(&so->so_rcv);
784 		if (available < ic->ic_receive_len) {
785 			so->so_rcv.sb_lowat = ic->ic_receive_len;
786 			cv_wait(&ic->ic_receive_cv, &so->so_rcv.sb_mtx);
787 		} else
788 			so->so_rcv.sb_lowat = so->so_rcv.sb_hiwat + 1;
789 		SOCKBUF_UNLOCK(&so->so_rcv);
790 
791 		icl_conn_receive_pdus(ic, available);
792 	}
793 
794 	ICL_CONN_LOCK(ic);
795 	ic->ic_receive_running = false;
796 	cv_signal(&ic->ic_send_cv);
797 	ICL_CONN_UNLOCK(ic);
798 	kthread_exit();
799 }
800 
801 static int
802 icl_soupcall_receive(struct socket *so, void *arg, int waitflag)
803 {
804 	struct icl_conn *ic;
805 
806 	if (!soreadable(so))
807 		return (SU_OK);
808 
809 	ic = arg;
810 	cv_signal(&ic->ic_receive_cv);
811 	return (SU_OK);
812 }
813 
814 static int
815 icl_pdu_finalize(struct icl_pdu *request)
816 {
817 	size_t padding, pdu_len;
818 	uint32_t digest, zero = 0;
819 	int ok;
820 	struct icl_conn *ic;
821 
822 	ic = request->ip_conn;
823 
824 	icl_pdu_set_data_segment_length(request, request->ip_data_len);
825 
826 	pdu_len = icl_pdu_size(request);
827 
828 	if (ic->ic_header_crc32c) {
829 		digest = icl_mbuf_to_crc32c(request->ip_bhs_mbuf);
830 		ok = m_append(request->ip_bhs_mbuf, sizeof(digest),
831 		    (void *)&digest);
832 		if (ok != 1) {
833 			ICL_WARN("failed to append header digest");
834 			return (1);
835 		}
836 	}
837 
838 	if (request->ip_data_len != 0) {
839 		padding = icl_pdu_padding(request);
840 		if (padding > 0) {
841 			ok = m_append(request->ip_data_mbuf, padding,
842 			    (void *)&zero);
843 			if (ok != 1) {
844 				ICL_WARN("failed to append padding");
845 				return (1);
846 			}
847 		}
848 
849 		if (ic->ic_data_crc32c) {
850 			digest = icl_mbuf_to_crc32c(request->ip_data_mbuf);
851 
852 			ok = m_append(request->ip_data_mbuf, sizeof(digest),
853 			    (void *)&digest);
854 			if (ok != 1) {
855 				ICL_WARN("failed to append data digest");
856 				return (1);
857 			}
858 		}
859 
860 		m_cat(request->ip_bhs_mbuf, request->ip_data_mbuf);
861 		request->ip_data_mbuf = NULL;
862 	}
863 
864 	request->ip_bhs_mbuf->m_pkthdr.len = pdu_len;
865 
866 	return (0);
867 }
868 
869 static void
870 icl_conn_send_pdus(struct icl_conn *ic, struct icl_pdu_stailq *queue)
871 {
872 	struct icl_pdu *request, *request2;
873 	struct socket *so;
874 	long available, size, size2;
875 	int coalesced, error;
876 
877 	ICL_CONN_LOCK_ASSERT_NOT(ic);
878 
879 	so = ic->ic_socket;
880 
881 	SOCKBUF_LOCK(&so->so_snd);
882 	/*
883 	 * Check how much space do we have for transmit.  We can't just
884 	 * call sosend() and retry when we get EWOULDBLOCK or EMSGSIZE,
885 	 * as it always frees the mbuf chain passed to it, even in case
886 	 * of error.
887 	 */
888 	available = sbspace(&so->so_snd);
889 
890 	/*
891 	 * Notify the socket upcall that we don't need wakeups
892 	 * for the time being.
893 	 */
894 	so->so_snd.sb_lowat = so->so_snd.sb_hiwat + 1;
895 	SOCKBUF_UNLOCK(&so->so_snd);
896 
897 	while (!STAILQ_EMPTY(queue)) {
898 		request = STAILQ_FIRST(queue);
899 		size = icl_pdu_size(request);
900 		if (available < size) {
901 
902 			/*
903 			 * Set the low watermark, to be checked by
904 			 * sowriteable() in icl_soupcall_send()
905 			 * to avoid unnecessary wakeups until there
906 			 * is enough space for the PDU to fit.
907 			 */
908 			SOCKBUF_LOCK(&so->so_snd);
909 			available = sbspace(&so->so_snd);
910 			if (available < size) {
911 #if 1
912 				ICL_DEBUG("no space to send; "
913 				    "have %ld, need %ld",
914 				    available, size);
915 #endif
916 				so->so_snd.sb_lowat = size;
917 				SOCKBUF_UNLOCK(&so->so_snd);
918 				return;
919 			}
920 			SOCKBUF_UNLOCK(&so->so_snd);
921 		}
922 		STAILQ_REMOVE_HEAD(queue, ip_next);
923 		error = icl_pdu_finalize(request);
924 		if (error != 0) {
925 			ICL_DEBUG("failed to finalize PDU; "
926 			    "dropping connection");
927 			icl_soft_conn_pdu_free(ic, request);
928 			icl_conn_fail(ic);
929 			return;
930 		}
931 		if (coalesce) {
932 			coalesced = 1;
933 			for (;;) {
934 				request2 = STAILQ_FIRST(queue);
935 				if (request2 == NULL)
936 					break;
937 				size2 = icl_pdu_size(request2);
938 				if (available < size + size2)
939 					break;
940 				STAILQ_REMOVE_HEAD(queue, ip_next);
941 				error = icl_pdu_finalize(request2);
942 				if (error != 0) {
943 					ICL_DEBUG("failed to finalize PDU; "
944 					    "dropping connection");
945 					icl_soft_conn_pdu_free(ic, request);
946 					icl_soft_conn_pdu_free(ic, request2);
947 					icl_conn_fail(ic);
948 					return;
949 				}
950 				m_cat(request->ip_bhs_mbuf, request2->ip_bhs_mbuf);
951 				request2->ip_bhs_mbuf = NULL;
952 				request->ip_bhs_mbuf->m_pkthdr.len += size2;
953 				size += size2;
954 				STAILQ_REMOVE_AFTER(queue, request, ip_next);
955 				icl_soft_conn_pdu_free(ic, request2);
956 				coalesced++;
957 			}
958 #if 0
959 			if (coalesced > 1) {
960 				ICL_DEBUG("coalesced %d PDUs into %ld bytes",
961 				    coalesced, size);
962 			}
963 #endif
964 		}
965 		available -= size;
966 		error = sosend(so, NULL, NULL, request->ip_bhs_mbuf,
967 		    NULL, MSG_DONTWAIT, curthread);
968 		request->ip_bhs_mbuf = NULL; /* Sosend consumes the mbuf. */
969 		if (error != 0) {
970 			ICL_DEBUG("failed to send PDU, error %d; "
971 			    "dropping connection", error);
972 			icl_soft_conn_pdu_free(ic, request);
973 			icl_conn_fail(ic);
974 			return;
975 		}
976 		icl_soft_conn_pdu_free(ic, request);
977 	}
978 }
979 
980 static void
981 icl_send_thread(void *arg)
982 {
983 	struct icl_conn *ic;
984 	struct icl_pdu_stailq queue;
985 
986 	ic = arg;
987 
988 	STAILQ_INIT(&queue);
989 
990 	ICL_CONN_LOCK(ic);
991 	for (;;) {
992 		for (;;) {
993 			/*
994 			 * If the local queue is empty, populate it from
995 			 * the main one.  This way the icl_conn_send_pdus()
996 			 * can go through all the queued PDUs without holding
997 			 * any locks.
998 			 */
999 			if (STAILQ_EMPTY(&queue))
1000 				STAILQ_SWAP(&ic->ic_to_send, &queue, icl_pdu);
1001 
1002 			ic->ic_check_send_space = false;
1003 			ICL_CONN_UNLOCK(ic);
1004 			icl_conn_send_pdus(ic, &queue);
1005 			ICL_CONN_LOCK(ic);
1006 
1007 			/*
1008 			 * The icl_soupcall_send() was called since the last
1009 			 * call to sbspace(); go around;
1010 			 */
1011 			if (ic->ic_check_send_space)
1012 				continue;
1013 
1014 			/*
1015 			 * Local queue is empty, but we still have PDUs
1016 			 * in the main one; go around.
1017 			 */
1018 			if (STAILQ_EMPTY(&queue) &&
1019 			    !STAILQ_EMPTY(&ic->ic_to_send))
1020 				continue;
1021 
1022 			/*
1023 			 * There might be some stuff in the local queue,
1024 			 * which didn't get sent due to not having enough send
1025 			 * space.  Wait for socket upcall.
1026 			 */
1027 			break;
1028 		}
1029 
1030 		if (ic->ic_disconnecting) {
1031 			//ICL_DEBUG("terminating");
1032 			break;
1033 		}
1034 
1035 		cv_wait(&ic->ic_send_cv, ic->ic_lock);
1036 	}
1037 
1038 	/*
1039 	 * We're exiting; move PDUs back to the main queue, so they can
1040 	 * get freed properly.  At this point ordering doesn't matter.
1041 	 */
1042 	STAILQ_CONCAT(&ic->ic_to_send, &queue);
1043 
1044 	ic->ic_send_running = false;
1045 	cv_signal(&ic->ic_send_cv);
1046 	ICL_CONN_UNLOCK(ic);
1047 	kthread_exit();
1048 }
1049 
1050 static int
1051 icl_soupcall_send(struct socket *so, void *arg, int waitflag)
1052 {
1053 	struct icl_conn *ic;
1054 
1055 	if (!sowriteable(so))
1056 		return (SU_OK);
1057 
1058 	ic = arg;
1059 
1060 	ICL_CONN_LOCK(ic);
1061 	ic->ic_check_send_space = true;
1062 	ICL_CONN_UNLOCK(ic);
1063 
1064 	cv_signal(&ic->ic_send_cv);
1065 
1066 	return (SU_OK);
1067 }
1068 
1069 static int
1070 icl_soft_conn_pdu_append_data(struct icl_conn *ic, struct icl_pdu *request,
1071     const void *addr, size_t len, int flags)
1072 {
1073 	struct mbuf *mb, *newmb;
1074 	size_t copylen, off = 0;
1075 
1076 	KASSERT(len > 0, ("len == 0"));
1077 
1078 	newmb = m_getm2(NULL, len, flags, MT_DATA, 0);
1079 	if (newmb == NULL) {
1080 		ICL_WARN("failed to allocate mbuf for %zd bytes", len);
1081 		return (ENOMEM);
1082 	}
1083 
1084 	for (mb = newmb; mb != NULL; mb = mb->m_next) {
1085 		copylen = min(M_TRAILINGSPACE(mb), len - off);
1086 		memcpy(mtod(mb, char *), (const char *)addr + off, copylen);
1087 		mb->m_len = copylen;
1088 		off += copylen;
1089 	}
1090 	KASSERT(off == len, ("%s: off != len", __func__));
1091 
1092 	if (request->ip_data_mbuf == NULL) {
1093 		request->ip_data_mbuf = newmb;
1094 		request->ip_data_len = len;
1095 	} else {
1096 		m_cat(request->ip_data_mbuf, newmb);
1097 		request->ip_data_len += len;
1098 	}
1099 
1100 	return (0);
1101 }
1102 
1103 void
1104 icl_soft_conn_pdu_get_data(struct icl_conn *ic, struct icl_pdu *ip,
1105     size_t off, void *addr, size_t len)
1106 {
1107 
1108 	m_copydata(ip->ip_data_mbuf, off, len, addr);
1109 }
1110 
1111 static void
1112 icl_pdu_queue(struct icl_pdu *ip)
1113 {
1114 	struct icl_conn *ic;
1115 
1116 	ic = ip->ip_conn;
1117 
1118 	ICL_CONN_LOCK_ASSERT(ic);
1119 
1120 	if (ic->ic_disconnecting || ic->ic_socket == NULL) {
1121 		ICL_DEBUG("icl_pdu_queue on closed connection");
1122 		icl_soft_conn_pdu_free(ic, ip);
1123 		return;
1124 	}
1125 
1126 	if (!STAILQ_EMPTY(&ic->ic_to_send)) {
1127 		STAILQ_INSERT_TAIL(&ic->ic_to_send, ip, ip_next);
1128 		/*
1129 		 * If the queue is not empty, someone else had already
1130 		 * signaled the send thread; no need to do that again,
1131 		 * just return.
1132 		 */
1133 		return;
1134 	}
1135 
1136 	STAILQ_INSERT_TAIL(&ic->ic_to_send, ip, ip_next);
1137 	cv_signal(&ic->ic_send_cv);
1138 }
1139 
1140 void
1141 icl_soft_conn_pdu_queue(struct icl_conn *ic, struct icl_pdu *ip)
1142 {
1143 
1144 	icl_pdu_queue(ip);
1145 }
1146 
1147 static struct icl_conn *
1148 icl_soft_new_conn(const char *name, struct mtx *lock)
1149 {
1150 	struct icl_conn *ic;
1151 
1152 	refcount_acquire(&icl_ncons);
1153 
1154 	ic = (struct icl_conn *)kobj_create(&icl_soft_class, M_ICL_SOFT, M_WAITOK | M_ZERO);
1155 
1156 	STAILQ_INIT(&ic->ic_to_send);
1157 	ic->ic_lock = lock;
1158 	cv_init(&ic->ic_send_cv, "icl_tx");
1159 	cv_init(&ic->ic_receive_cv, "icl_rx");
1160 #ifdef DIAGNOSTIC
1161 	refcount_init(&ic->ic_outstanding_pdus, 0);
1162 #endif
1163 	ic->ic_max_data_segment_length = ICL_MAX_DATA_SEGMENT_LENGTH;
1164 	ic->ic_name = name;
1165 	ic->ic_offload = "None";
1166 	ic->ic_unmapped = false;
1167 
1168 	return (ic);
1169 }
1170 
1171 void
1172 icl_soft_conn_free(struct icl_conn *ic)
1173 {
1174 
1175 #ifdef DIAGNOSTIC
1176 	KASSERT(ic->ic_outstanding_pdus == 0,
1177 	    ("destroying session with %d outstanding PDUs",
1178 	     ic->ic_outstanding_pdus));
1179 #endif
1180 	cv_destroy(&ic->ic_send_cv);
1181 	cv_destroy(&ic->ic_receive_cv);
1182 	kobj_delete((struct kobj *)ic, M_ICL_SOFT);
1183 	refcount_release(&icl_ncons);
1184 }
1185 
1186 static int
1187 icl_conn_start(struct icl_conn *ic)
1188 {
1189 	size_t minspace;
1190 	struct sockopt opt;
1191 	int error, one = 1;
1192 
1193 	ICL_CONN_LOCK(ic);
1194 
1195 	/*
1196 	 * XXX: Ugly hack.
1197 	 */
1198 	if (ic->ic_socket == NULL) {
1199 		ICL_CONN_UNLOCK(ic);
1200 		return (EINVAL);
1201 	}
1202 
1203 	ic->ic_receive_state = ICL_CONN_STATE_BHS;
1204 	ic->ic_receive_len = sizeof(struct iscsi_bhs);
1205 	ic->ic_disconnecting = false;
1206 
1207 	ICL_CONN_UNLOCK(ic);
1208 
1209 	/*
1210 	 * For sendspace, this is required because the current code cannot
1211 	 * send a PDU in pieces; thus, the minimum buffer size is equal
1212 	 * to the maximum PDU size.  "+4" is to account for possible padding.
1213 	 *
1214 	 * What we should actually do here is to use autoscaling, but set
1215 	 * some minimal buffer size to "minspace".  I don't know a way to do
1216 	 * that, though.
1217 	 */
1218 	minspace = sizeof(struct iscsi_bhs) + ic->ic_max_data_segment_length +
1219 	    ISCSI_HEADER_DIGEST_SIZE + ISCSI_DATA_DIGEST_SIZE + 4;
1220 	if (sendspace < minspace) {
1221 		ICL_WARN("kern.icl.sendspace too low; must be at least %zd",
1222 		    minspace);
1223 		sendspace = minspace;
1224 	}
1225 	if (recvspace < minspace) {
1226 		ICL_WARN("kern.icl.recvspace too low; must be at least %zd",
1227 		    minspace);
1228 		recvspace = minspace;
1229 	}
1230 
1231 	error = soreserve(ic->ic_socket, sendspace, recvspace);
1232 	if (error != 0) {
1233 		ICL_WARN("soreserve failed with error %d", error);
1234 		icl_soft_conn_close(ic);
1235 		return (error);
1236 	}
1237 	ic->ic_socket->so_snd.sb_flags |= SB_AUTOSIZE;
1238 	ic->ic_socket->so_rcv.sb_flags |= SB_AUTOSIZE;
1239 
1240 	/*
1241 	 * Disable Nagle.
1242 	 */
1243 	bzero(&opt, sizeof(opt));
1244 	opt.sopt_dir = SOPT_SET;
1245 	opt.sopt_level = IPPROTO_TCP;
1246 	opt.sopt_name = TCP_NODELAY;
1247 	opt.sopt_val = &one;
1248 	opt.sopt_valsize = sizeof(one);
1249 	error = sosetopt(ic->ic_socket, &opt);
1250 	if (error != 0) {
1251 		ICL_WARN("disabling TCP_NODELAY failed with error %d", error);
1252 		icl_soft_conn_close(ic);
1253 		return (error);
1254 	}
1255 
1256 	/*
1257 	 * Register socket upcall, to get notified about incoming PDUs
1258 	 * and free space to send outgoing ones.
1259 	 */
1260 	SOCKBUF_LOCK(&ic->ic_socket->so_snd);
1261 	soupcall_set(ic->ic_socket, SO_SND, icl_soupcall_send, ic);
1262 	SOCKBUF_UNLOCK(&ic->ic_socket->so_snd);
1263 	SOCKBUF_LOCK(&ic->ic_socket->so_rcv);
1264 	soupcall_set(ic->ic_socket, SO_RCV, icl_soupcall_receive, ic);
1265 	SOCKBUF_UNLOCK(&ic->ic_socket->so_rcv);
1266 
1267 	/*
1268 	 * Start threads.
1269 	 */
1270 	ICL_CONN_LOCK(ic);
1271 	ic->ic_send_running = ic->ic_receive_running = true;
1272 	ICL_CONN_UNLOCK(ic);
1273 	error = kthread_add(icl_send_thread, ic, NULL, NULL, 0, 0, "%stx",
1274 	    ic->ic_name);
1275 	if (error != 0) {
1276 		ICL_WARN("kthread_add(9) failed with error %d", error);
1277 		ICL_CONN_LOCK(ic);
1278 		ic->ic_send_running = ic->ic_receive_running = false;
1279 		cv_signal(&ic->ic_send_cv);
1280 		ICL_CONN_UNLOCK(ic);
1281 		icl_soft_conn_close(ic);
1282 		return (error);
1283 	}
1284 	error = kthread_add(icl_receive_thread, ic, NULL, NULL, 0, 0, "%srx",
1285 	    ic->ic_name);
1286 	if (error != 0) {
1287 		ICL_WARN("kthread_add(9) failed with error %d", error);
1288 		ICL_CONN_LOCK(ic);
1289 		ic->ic_receive_running = false;
1290 		cv_signal(&ic->ic_send_cv);
1291 		ICL_CONN_UNLOCK(ic);
1292 		icl_soft_conn_close(ic);
1293 		return (error);
1294 	}
1295 
1296 	return (0);
1297 }
1298 
1299 int
1300 icl_soft_conn_handoff(struct icl_conn *ic, int fd)
1301 {
1302 	struct file *fp;
1303 	struct socket *so;
1304 	cap_rights_t rights;
1305 	int error;
1306 
1307 	ICL_CONN_LOCK_ASSERT_NOT(ic);
1308 
1309 #ifdef ICL_KERNEL_PROXY
1310 	/*
1311 	 * We're transitioning to Full Feature phase, and we don't
1312 	 * really care.
1313 	 */
1314 	if (fd == 0) {
1315 		ICL_CONN_LOCK(ic);
1316 		if (ic->ic_socket == NULL) {
1317 			ICL_CONN_UNLOCK(ic);
1318 			ICL_WARN("proxy handoff without connect");
1319 			return (EINVAL);
1320 		}
1321 		ICL_CONN_UNLOCK(ic);
1322 		return (0);
1323 	}
1324 #endif
1325 
1326 	/*
1327 	 * Steal the socket from userland.
1328 	 */
1329 	error = fget(curthread, fd,
1330 	    cap_rights_init(&rights, CAP_SOCK_CLIENT), &fp);
1331 	if (error != 0)
1332 		return (error);
1333 	if (fp->f_type != DTYPE_SOCKET) {
1334 		fdrop(fp, curthread);
1335 		return (EINVAL);
1336 	}
1337 	so = fp->f_data;
1338 	if (so->so_type != SOCK_STREAM) {
1339 		fdrop(fp, curthread);
1340 		return (EINVAL);
1341 	}
1342 
1343 	ICL_CONN_LOCK(ic);
1344 
1345 	if (ic->ic_socket != NULL) {
1346 		ICL_CONN_UNLOCK(ic);
1347 		fdrop(fp, curthread);
1348 		return (EBUSY);
1349 	}
1350 
1351 	ic->ic_socket = fp->f_data;
1352 	fp->f_ops = &badfileops;
1353 	fp->f_data = NULL;
1354 	fdrop(fp, curthread);
1355 	ICL_CONN_UNLOCK(ic);
1356 
1357 	error = icl_conn_start(ic);
1358 
1359 	return (error);
1360 }
1361 
1362 void
1363 icl_soft_conn_close(struct icl_conn *ic)
1364 {
1365 	struct icl_pdu *pdu;
1366 	struct socket *so;
1367 
1368 	ICL_CONN_LOCK(ic);
1369 
1370 	/*
1371 	 * Wake up the threads, so they can properly terminate.
1372 	 */
1373 	ic->ic_disconnecting = true;
1374 	while (ic->ic_receive_running || ic->ic_send_running) {
1375 		cv_signal(&ic->ic_receive_cv);
1376 		cv_signal(&ic->ic_send_cv);
1377 		cv_wait(&ic->ic_send_cv, ic->ic_lock);
1378 	}
1379 
1380 	/* Some other thread could close the connection same time. */
1381 	so = ic->ic_socket;
1382 	if (so == NULL) {
1383 		ICL_CONN_UNLOCK(ic);
1384 		return;
1385 	}
1386 	ic->ic_socket = NULL;
1387 
1388 	/*
1389 	 * Deregister socket upcalls.
1390 	 */
1391 	ICL_CONN_UNLOCK(ic);
1392 	SOCKBUF_LOCK(&so->so_snd);
1393 	if (so->so_snd.sb_upcall != NULL)
1394 		soupcall_clear(so, SO_SND);
1395 	SOCKBUF_UNLOCK(&so->so_snd);
1396 	SOCKBUF_LOCK(&so->so_rcv);
1397 	if (so->so_rcv.sb_upcall != NULL)
1398 		soupcall_clear(so, SO_RCV);
1399 	SOCKBUF_UNLOCK(&so->so_rcv);
1400 	soclose(so);
1401 	ICL_CONN_LOCK(ic);
1402 
1403 	if (ic->ic_receive_pdu != NULL) {
1404 		//ICL_DEBUG("freeing partially received PDU");
1405 		icl_soft_conn_pdu_free(ic, ic->ic_receive_pdu);
1406 		ic->ic_receive_pdu = NULL;
1407 	}
1408 
1409 	/*
1410 	 * Remove any outstanding PDUs from the send queue.
1411 	 */
1412 	while (!STAILQ_EMPTY(&ic->ic_to_send)) {
1413 		pdu = STAILQ_FIRST(&ic->ic_to_send);
1414 		STAILQ_REMOVE_HEAD(&ic->ic_to_send, ip_next);
1415 		icl_soft_conn_pdu_free(ic, pdu);
1416 	}
1417 
1418 	KASSERT(STAILQ_EMPTY(&ic->ic_to_send),
1419 	    ("destroying session with non-empty send queue"));
1420 	ICL_CONN_UNLOCK(ic);
1421 }
1422 
1423 int
1424 icl_soft_conn_task_setup(struct icl_conn *ic, struct icl_pdu *ip,
1425     struct ccb_scsiio *csio, uint32_t *task_tagp, void **prvp)
1426 {
1427 
1428 	return (0);
1429 }
1430 
1431 void
1432 icl_soft_conn_task_done(struct icl_conn *ic, void *prv)
1433 {
1434 }
1435 
1436 int
1437 icl_soft_conn_transfer_setup(struct icl_conn *ic, union ctl_io *io,
1438     uint32_t *transfer_tag, void **prvp)
1439 {
1440 
1441 	return (0);
1442 }
1443 
1444 void
1445 icl_soft_conn_transfer_done(struct icl_conn *ic, void *prv)
1446 {
1447 }
1448 
1449 static int
1450 icl_soft_limits(struct icl_drv_limits *idl)
1451 {
1452 
1453 	idl->idl_max_recv_data_segment_length = 128 * 1024;
1454 	idl->idl_max_send_data_segment_length = 128 * 1024;
1455 	idl->idl_max_burst_length = 262144;
1456 	idl->idl_first_burst_length = 65536;
1457 
1458 	return (0);
1459 }
1460 
1461 #ifdef ICL_KERNEL_PROXY
1462 int
1463 icl_soft_conn_connect(struct icl_conn *ic, int domain, int socktype,
1464     int protocol, struct sockaddr *from_sa, struct sockaddr *to_sa)
1465 {
1466 
1467 	return (icl_soft_proxy_connect(ic, domain, socktype, protocol,
1468 	    from_sa, to_sa));
1469 }
1470 
1471 int
1472 icl_soft_handoff_sock(struct icl_conn *ic, struct socket *so)
1473 {
1474 	int error;
1475 
1476 	ICL_CONN_LOCK_ASSERT_NOT(ic);
1477 
1478 	if (so->so_type != SOCK_STREAM)
1479 		return (EINVAL);
1480 
1481 	ICL_CONN_LOCK(ic);
1482 	if (ic->ic_socket != NULL) {
1483 		ICL_CONN_UNLOCK(ic);
1484 		return (EBUSY);
1485 	}
1486 	ic->ic_socket = so;
1487 	ICL_CONN_UNLOCK(ic);
1488 
1489 	error = icl_conn_start(ic);
1490 
1491 	return (error);
1492 }
1493 #endif /* ICL_KERNEL_PROXY */
1494 
1495 static int
1496 icl_soft_load(void)
1497 {
1498 	int error;
1499 
1500 	icl_pdu_zone = uma_zcreate("icl_pdu",
1501 	    sizeof(struct icl_pdu), NULL, NULL, NULL, NULL,
1502 	    UMA_ALIGN_PTR, 0);
1503 	refcount_init(&icl_ncons, 0);
1504 
1505 	/*
1506 	 * The reason we call this "none" is that to the user,
1507 	 * it's known as "offload driver"; "offload driver: soft"
1508 	 * doesn't make much sense.
1509 	 */
1510 	error = icl_register("none", false, 0,
1511 	    icl_soft_limits, icl_soft_new_conn);
1512 	KASSERT(error == 0, ("failed to register"));
1513 
1514 #if defined(ICL_KERNEL_PROXY) && 0
1515 	/*
1516 	 * Debugging aid for kernel proxy functionality.
1517 	 */
1518 	error = icl_register("proxytest", true, 0,
1519 	    icl_soft_limits, icl_soft_new_conn);
1520 	KASSERT(error == 0, ("failed to register"));
1521 #endif
1522 
1523 	return (error);
1524 }
1525 
1526 static int
1527 icl_soft_unload(void)
1528 {
1529 
1530 	if (icl_ncons != 0)
1531 		return (EBUSY);
1532 
1533 	icl_unregister("none", false);
1534 #if defined(ICL_KERNEL_PROXY) && 0
1535 	icl_unregister("proxytest", true);
1536 #endif
1537 
1538 	uma_zdestroy(icl_pdu_zone);
1539 
1540 	return (0);
1541 }
1542 
1543 static int
1544 icl_soft_modevent(module_t mod, int what, void *arg)
1545 {
1546 
1547 	switch (what) {
1548 	case MOD_LOAD:
1549 		return (icl_soft_load());
1550 	case MOD_UNLOAD:
1551 		return (icl_soft_unload());
1552 	default:
1553 		return (EINVAL);
1554 	}
1555 }
1556 
1557 moduledata_t icl_soft_data = {
1558 	"icl_soft",
1559 	icl_soft_modevent,
1560 	0
1561 };
1562 
1563 DECLARE_MODULE(icl_soft, icl_soft_data, SI_SUB_DRIVERS, SI_ORDER_MIDDLE);
1564 MODULE_DEPEND(icl_soft, icl, 1, 1, 1);
1565 MODULE_VERSION(icl_soft, 1);
1566