xref: /freebsd/sys/dev/hyperv/hvsock/hv_sock.c (revision a3266ba2697a383d2ede56803320d941866c7e76)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2020 Microsoft Corp.
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice unmodified, this list of conditions, and the following
12  *    disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27  */
28 
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
31 
32 #include <sys/param.h>
33 #include <sys/bus.h>
34 #include <sys/domain.h>
35 #include <sys/lock.h>
36 #include <sys/kernel.h>
37 #include <sys/types.h>
38 #include <sys/malloc.h>
39 #include <sys/module.h>
40 #include <sys/mutex.h>
41 #include <sys/proc.h>
42 #include <sys/protosw.h>
43 #include <sys/socket.h>
44 #include <sys/sysctl.h>
45 #include <sys/sysproto.h>
46 #include <sys/systm.h>
47 #include <sys/sockbuf.h>
48 #include <sys/sx.h>
49 #include <sys/uio.h>
50 
51 #include <net/vnet.h>
52 
53 #include <dev/hyperv/vmbus/vmbus_reg.h>
54 
55 #include "hv_sock.h"
56 
57 #define HVSOCK_DBG_NONE			0x0
58 #define HVSOCK_DBG_INFO			0x1
59 #define HVSOCK_DBG_ERR			0x2
60 #define HVSOCK_DBG_VERBOSE		0x3
61 
62 
63 SYSCTL_NODE(_net, OID_AUTO, hvsock, CTLFLAG_RD, 0, "HyperV socket");
64 
65 static int hvs_dbg_level;
66 SYSCTL_INT(_net_hvsock, OID_AUTO, hvs_dbg_level, CTLFLAG_RWTUN, &hvs_dbg_level,
67     0, "hyperv socket debug level: 0 = none, 1 = info, 2 = error, 3 = verbose");
68 
69 
70 #define HVSOCK_DBG(level, ...) do {					\
71 	if (hvs_dbg_level >= (level))					\
72 		printf(__VA_ARGS__);					\
73 	} while (0)
74 
75 MALLOC_DEFINE(M_HVSOCK, "hyperv_socket", "hyperv socket control structures");
76 
77 static int hvs_dom_probe(void);
78 
79 /* The MTU is 16KB per host side's design */
80 #define HVSOCK_MTU_SIZE		(1024 * 16)
81 #define HVSOCK_SEND_BUF_SZ	(PAGE_SIZE - sizeof(struct vmpipe_proto_header))
82 
83 #define HVSOCK_HEADER_LEN	(sizeof(struct hvs_pkt_header))
84 
85 #define HVSOCK_PKT_LEN(payload_len)	(HVSOCK_HEADER_LEN + \
86 					 roundup2(payload_len, 8) + \
87 					 sizeof(uint64_t))
88 
89 
90 static struct domain		hv_socket_domain;
91 
92 /*
93  * HyperV Transport sockets
94  */
95 static struct pr_usrreqs	hvs_trans_usrreqs = {
96 	.pru_attach =		hvs_trans_attach,
97 	.pru_bind =		hvs_trans_bind,
98 	.pru_listen =		hvs_trans_listen,
99 	.pru_accept =		hvs_trans_accept,
100 	.pru_connect =		hvs_trans_connect,
101 	.pru_peeraddr =		hvs_trans_peeraddr,
102 	.pru_sockaddr =		hvs_trans_sockaddr,
103 	.pru_soreceive =	hvs_trans_soreceive,
104 	.pru_sosend =		hvs_trans_sosend,
105 	.pru_disconnect =	hvs_trans_disconnect,
106 	.pru_close =		hvs_trans_close,
107 	.pru_detach =		hvs_trans_detach,
108 	.pru_shutdown =		hvs_trans_shutdown,
109 	.pru_abort =		hvs_trans_abort,
110 };
111 
112 /*
113  * Definitions of protocols supported in HyperV socket domain
114  */
115 static struct protosw		hv_socket_protosw[] = {
116 {
117 	.pr_type =		SOCK_STREAM,
118 	.pr_domain =		&hv_socket_domain,
119 	.pr_protocol =		HYPERV_SOCK_PROTO_TRANS,
120 	.pr_flags =		PR_CONNREQUIRED,
121 	.pr_init =		hvs_trans_init,
122 	.pr_usrreqs =		&hvs_trans_usrreqs,
123 },
124 };
125 
126 static struct domain		hv_socket_domain = {
127 	.dom_family =		AF_HYPERV,
128 	.dom_name =		"hyperv",
129 	.dom_probe =		hvs_dom_probe,
130 	.dom_protosw =		hv_socket_protosw,
131 	.dom_protoswNPROTOSW =	&hv_socket_protosw[nitems(hv_socket_protosw)]
132 };
133 
134 VNET_DOMAIN_SET(hv_socket_);
135 
136 #define MAX_PORT			((uint32_t)0xFFFFFFFF)
137 #define MIN_PORT			((uint32_t)0x0)
138 
139 /* 00000000-facb-11e6-bd58-64006a7986d3 */
140 static const struct hyperv_guid srv_id_template = {
141 	.hv_guid = {
142 	    0x00, 0x00, 0x00, 0x00, 0xcb, 0xfa, 0xe6, 0x11,
143 	    0xbd, 0x58, 0x64, 0x00, 0x6a, 0x79, 0x86, 0xd3 }
144 };
145 
146 static int		hvsock_br_callback(void *, int, void *);
147 static uint32_t		hvsock_canread_check(struct hvs_pcb *);
148 static uint32_t		hvsock_canwrite_check(struct hvs_pcb *);
149 static int		hvsock_send_data(struct vmbus_channel *chan,
150     struct uio *uio, uint32_t to_write, struct sockbuf *sb);
151 
152 
153 
154 /* Globals */
155 static struct sx		hvs_trans_socks_sx;
156 static struct mtx		hvs_trans_socks_mtx;
157 static LIST_HEAD(, hvs_pcb)	hvs_trans_bound_socks;
158 static LIST_HEAD(, hvs_pcb)	hvs_trans_connected_socks;
159 static uint32_t			previous_auto_bound_port;
160 
161 static void
162 hvsock_print_guid(struct hyperv_guid *guid)
163 {
164 	unsigned char *p = (unsigned char *)guid;
165 
166 	HVSOCK_DBG(HVSOCK_DBG_INFO,
167 	    "0x%x-0x%x-0x%x-0x%x-0x%x-0x%x-0x%x-0x%x-0x%x-0x%x-0x%x\n",
168 	    *(unsigned int *)p,
169 	    *((unsigned short *) &p[4]),
170 	    *((unsigned short *) &p[6]),
171 	    p[8], p[9], p[10], p[11], p[12], p[13], p[14], p[15]);
172 }
173 
174 static bool
175 is_valid_srv_id(const struct hyperv_guid *id)
176 {
177 	return !memcmp(&id->hv_guid[4],
178 	    &srv_id_template.hv_guid[4], sizeof(struct hyperv_guid) - 4);
179 }
180 
181 static unsigned int
182 get_port_by_srv_id(const struct hyperv_guid *srv_id)
183 {
184 	return *((const unsigned int *)srv_id);
185 }
186 
187 static void
188 set_port_by_srv_id(struct hyperv_guid *srv_id, unsigned int port)
189 {
190 	*((unsigned int *)srv_id) = port;
191 }
192 
193 
194 static void
195 __hvs_remove_pcb_from_list(struct hvs_pcb *pcb, unsigned char list)
196 {
197 	struct hvs_pcb *p = NULL;
198 
199 	HVSOCK_DBG(HVSOCK_DBG_VERBOSE, "%s: pcb is %p\n", __func__, pcb);
200 
201 	if (!pcb)
202 		return;
203 
204 	if (list & HVS_LIST_BOUND) {
205 		LIST_FOREACH(p, &hvs_trans_bound_socks, bound_next)
206 			if  (p == pcb)
207 				LIST_REMOVE(p, bound_next);
208 	}
209 
210 	if (list & HVS_LIST_CONNECTED) {
211 		LIST_FOREACH(p, &hvs_trans_connected_socks, connected_next)
212 			if (p == pcb)
213 				LIST_REMOVE(pcb, connected_next);
214 	}
215 }
216 
217 static void
218 __hvs_remove_socket_from_list(struct socket *so, unsigned char list)
219 {
220 	struct hvs_pcb *pcb = so2hvspcb(so);
221 
222 	HVSOCK_DBG(HVSOCK_DBG_VERBOSE, "%s: pcb is %p\n", __func__, pcb);
223 
224 	__hvs_remove_pcb_from_list(pcb, list);
225 }
226 
227 static void
228 __hvs_insert_socket_on_list(struct socket *so, unsigned char list)
229 {
230 	struct hvs_pcb *pcb = so2hvspcb(so);
231 
232 	if (list & HVS_LIST_BOUND)
233 		LIST_INSERT_HEAD(&hvs_trans_bound_socks,
234 		   pcb, bound_next);
235 
236 	if (list & HVS_LIST_CONNECTED)
237 		LIST_INSERT_HEAD(&hvs_trans_connected_socks,
238 		   pcb, connected_next);
239 }
240 
241 void
242 hvs_remove_socket_from_list(struct socket *so, unsigned char list)
243 {
244 	if (!so || !so->so_pcb) {
245 		HVSOCK_DBG(HVSOCK_DBG_VERBOSE,
246 		    "%s: socket or so_pcb is null\n", __func__);
247 		return;
248 	}
249 
250 	mtx_lock(&hvs_trans_socks_mtx);
251 	__hvs_remove_socket_from_list(so, list);
252 	mtx_unlock(&hvs_trans_socks_mtx);
253 }
254 
255 static void
256 hvs_insert_socket_on_list(struct socket *so, unsigned char list)
257 {
258 	if (!so || !so->so_pcb) {
259 		HVSOCK_DBG(HVSOCK_DBG_VERBOSE,
260 		    "%s: socket or so_pcb is null\n", __func__);
261 		return;
262 	}
263 
264 	mtx_lock(&hvs_trans_socks_mtx);
265 	__hvs_insert_socket_on_list(so, list);
266 	mtx_unlock(&hvs_trans_socks_mtx);
267 }
268 
269 static struct socket *
270 __hvs_find_socket_on_list(struct sockaddr_hvs *addr, unsigned char list)
271 {
272 	struct hvs_pcb *p = NULL;
273 
274 	if (list & HVS_LIST_BOUND)
275 		LIST_FOREACH(p, &hvs_trans_bound_socks, bound_next)
276 			if (p->so != NULL &&
277 			    addr->hvs_port == p->local_addr.hvs_port)
278 				return p->so;
279 
280 	if (list & HVS_LIST_CONNECTED)
281 		LIST_FOREACH(p, &hvs_trans_connected_socks, connected_next)
282 			if (p->so != NULL &&
283 			    addr->hvs_port == p->local_addr.hvs_port)
284 				return p->so;
285 
286 	return NULL;
287 }
288 
289 static struct socket *
290 hvs_find_socket_on_list(struct sockaddr_hvs *addr, unsigned char list)
291 {
292 	struct socket *s = NULL;
293 
294 	mtx_lock(&hvs_trans_socks_mtx);
295 	s = __hvs_find_socket_on_list(addr, list);
296 	mtx_unlock(&hvs_trans_socks_mtx);
297 
298 	return s;
299 }
300 
301 static inline void
302 hvs_addr_set(struct sockaddr_hvs *addr, unsigned int port)
303 {
304 	memset(addr, 0, sizeof(*addr));
305 	addr->sa_family = AF_HYPERV;
306 	addr->sa_len = sizeof(*addr);
307 	addr->hvs_port = port;
308 }
309 
310 void
311 hvs_addr_init(struct sockaddr_hvs *addr, const struct hyperv_guid *svr_id)
312 {
313 	hvs_addr_set(addr, get_port_by_srv_id(svr_id));
314 }
315 
316 int
317 hvs_trans_lock(void)
318 {
319 	sx_xlock(&hvs_trans_socks_sx);
320 	return (0);
321 }
322 
323 void
324 hvs_trans_unlock(void)
325 {
326 	sx_xunlock(&hvs_trans_socks_sx);
327 }
328 
329 static int
330 hvs_dom_probe(void)
331 {
332 
333 	/* Don't even give us a chance to attach on non-HyperV. */
334 	if (vm_guest != VM_GUEST_HV)
335 		return (ENXIO);
336 	return (0);
337 }
338 
339 void
340 hvs_trans_init(void)
341 {
342 	/* Skip initialization of globals for non-default instances. */
343 	if (!IS_DEFAULT_VNET(curvnet))
344 		return;
345 
346 	HVSOCK_DBG(HVSOCK_DBG_VERBOSE,
347 	    "%s: HyperV Socket hvs_trans_init called\n", __func__);
348 
349 	/* Initialize Globals */
350 	previous_auto_bound_port = MAX_PORT;
351 	sx_init(&hvs_trans_socks_sx, "hvs_trans_sock_sx");
352 	mtx_init(&hvs_trans_socks_mtx,
353 	    "hvs_trans_socks_mtx", NULL, MTX_DEF);
354 	LIST_INIT(&hvs_trans_bound_socks);
355 	LIST_INIT(&hvs_trans_connected_socks);
356 }
357 
358 /*
359  * Called in two cases:
360  * 1) When user calls socket();
361  * 2) When we accept new incoming conneciton and call sonewconn().
362  */
363 int
364 hvs_trans_attach(struct socket *so, int proto, struct thread *td)
365 {
366 	struct hvs_pcb *pcb = so2hvspcb(so);
367 
368 	HVSOCK_DBG(HVSOCK_DBG_VERBOSE,
369 	    "%s: HyperV Socket hvs_trans_attach called\n", __func__);
370 
371 	if (so->so_type != SOCK_STREAM)
372 		return (ESOCKTNOSUPPORT);
373 
374 	if (proto != 0 && proto != HYPERV_SOCK_PROTO_TRANS)
375 		return (EPROTONOSUPPORT);
376 
377 	if (pcb != NULL)
378 		return (EISCONN);
379 	pcb = malloc(sizeof(struct hvs_pcb), M_HVSOCK, M_NOWAIT | M_ZERO);
380 	if (pcb == NULL)
381 		return (ENOMEM);
382 
383 	pcb->so = so;
384 	so->so_pcb = (void *)pcb;
385 
386 	return (0);
387 }
388 
389 void
390 hvs_trans_detach(struct socket *so)
391 {
392 	struct hvs_pcb *pcb;
393 
394 	HVSOCK_DBG(HVSOCK_DBG_VERBOSE,
395 	    "%s: HyperV Socket hvs_trans_detach called\n", __func__);
396 
397 	(void) hvs_trans_lock();
398 	pcb = so2hvspcb(so);
399 	if (pcb == NULL) {
400 		hvs_trans_unlock();
401 		return;
402 	}
403 
404 	if (SOLISTENING(so)) {
405 		bzero(pcb, sizeof(*pcb));
406 		free(pcb, M_HVSOCK);
407 	}
408 
409 	so->so_pcb = NULL;
410 
411 	hvs_trans_unlock();
412 }
413 
414 int
415 hvs_trans_bind(struct socket *so, struct sockaddr *addr, struct thread *td)
416 {
417 	struct hvs_pcb *pcb = so2hvspcb(so);
418 	struct sockaddr_hvs *sa = (struct sockaddr_hvs *) addr;
419 	int error = 0;
420 
421 	HVSOCK_DBG(HVSOCK_DBG_VERBOSE,
422 	    "%s: HyperV Socket hvs_trans_bind called\n", __func__);
423 
424 	if (sa == NULL) {
425 		return (EINVAL);
426 	}
427 
428 	if (pcb == NULL) {
429 		return (EINVAL);
430 	}
431 
432 	if (sa->sa_family != AF_HYPERV) {
433 		HVSOCK_DBG(HVSOCK_DBG_ERR,
434 		    "%s: Not supported, sa_family is %u\n",
435 		    __func__, sa->sa_family);
436 		return (EAFNOSUPPORT);
437 	}
438 	if (sa->sa_len != sizeof(*sa)) {
439 		HVSOCK_DBG(HVSOCK_DBG_ERR,
440 		    "%s: Not supported, sa_len is %u\n",
441 		    __func__, sa->sa_len);
442 		return (EINVAL);
443 	}
444 
445 	HVSOCK_DBG(HVSOCK_DBG_VERBOSE,
446 	    "%s: binding port = 0x%x\n", __func__, sa->hvs_port);
447 
448 	mtx_lock(&hvs_trans_socks_mtx);
449 	if (__hvs_find_socket_on_list(sa,
450 	    HVS_LIST_BOUND | HVS_LIST_CONNECTED)) {
451 		error = EADDRINUSE;
452 	} else {
453 		/*
454 		 * The address is available for us to bind.
455 		 * Add socket to the bound list.
456 		 */
457 		hvs_addr_set(&pcb->local_addr, sa->hvs_port);
458 		hvs_addr_set(&pcb->remote_addr, HVADDR_PORT_ANY);
459 		__hvs_insert_socket_on_list(so, HVS_LIST_BOUND);
460 	}
461 	mtx_unlock(&hvs_trans_socks_mtx);
462 
463 	return (error);
464 }
465 
466 int
467 hvs_trans_listen(struct socket *so, int backlog, struct thread *td)
468 {
469 	struct hvs_pcb *pcb = so2hvspcb(so);
470 	struct socket *bound_so;
471 	int error;
472 
473 	HVSOCK_DBG(HVSOCK_DBG_VERBOSE,
474 	    "%s: HyperV Socket hvs_trans_listen called\n", __func__);
475 
476 	if (pcb == NULL)
477 		return (EINVAL);
478 
479 	/* Check if the address is already bound and it was by us. */
480 	bound_so = hvs_find_socket_on_list(&pcb->local_addr, HVS_LIST_BOUND);
481 	if (bound_so == NULL || bound_so != so) {
482 		HVSOCK_DBG(HVSOCK_DBG_ERR,
483 		    "%s: Address not bound or not by us.\n", __func__);
484 		return (EADDRNOTAVAIL);
485 	}
486 
487 	SOCK_LOCK(so);
488 	error = solisten_proto_check(so);
489 	if (error == 0)
490 		solisten_proto(so, backlog);
491 	SOCK_UNLOCK(so);
492 
493 	HVSOCK_DBG(HVSOCK_DBG_VERBOSE,
494 	    "%s: HyperV Socket listen error = %d\n", __func__, error);
495 	return (error);
496 }
497 
498 int
499 hvs_trans_accept(struct socket *so, struct sockaddr **nam)
500 {
501 	struct hvs_pcb *pcb = so2hvspcb(so);
502 
503 	HVSOCK_DBG(HVSOCK_DBG_VERBOSE,
504 	    "%s: HyperV Socket hvs_trans_accept called\n", __func__);
505 
506 	if (pcb == NULL)
507 		return (EINVAL);
508 
509 	*nam = sodupsockaddr((struct sockaddr *) &pcb->remote_addr,
510 	    M_NOWAIT);
511 
512 	return ((*nam == NULL) ? ENOMEM : 0);
513 }
514 
515 int
516 hvs_trans_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
517 {
518 	struct hvs_pcb *pcb = so2hvspcb(so);
519 	struct sockaddr_hvs *raddr = (struct sockaddr_hvs *)nam;
520 	bool found_auto_bound_port = false;
521 	int i, error = 0;
522 
523 	HVSOCK_DBG(HVSOCK_DBG_VERBOSE,
524 	    "%s: HyperV Socket hvs_trans_connect called, remote port is %x\n",
525 	    __func__, raddr->hvs_port);
526 
527 	if (pcb == NULL)
528 		return (EINVAL);
529 
530 	/* Verify the remote address */
531 	if (raddr == NULL)
532 		return (EINVAL);
533 	if (raddr->sa_family != AF_HYPERV)
534 		return (EAFNOSUPPORT);
535 	if (raddr->sa_len != sizeof(*raddr))
536 		return (EINVAL);
537 
538 	mtx_lock(&hvs_trans_socks_mtx);
539 	if (so->so_state &
540 	    (SS_ISCONNECTED|SS_ISDISCONNECTING|SS_ISCONNECTING)) {
541 			HVSOCK_DBG(HVSOCK_DBG_ERR,
542 			    "%s: socket connect in progress\n",
543 			    __func__);
544 			error = EINPROGRESS;
545 			goto out;
546 	}
547 
548 	/*
549 	 * Find an available port for us to auto bind the local
550 	 * address.
551 	 */
552 	hvs_addr_set(&pcb->local_addr, 0);
553 
554 	for (i = previous_auto_bound_port - 1;
555 	    i != previous_auto_bound_port; i --) {
556 		if (i == MIN_PORT)
557 			i = MAX_PORT;
558 
559 		pcb->local_addr.hvs_port = i;
560 
561 		if (__hvs_find_socket_on_list(&pcb->local_addr,
562 		    HVS_LIST_BOUND | HVS_LIST_CONNECTED) == NULL) {
563 			found_auto_bound_port = true;
564 			previous_auto_bound_port = i;
565 			HVSOCK_DBG(HVSOCK_DBG_VERBOSE,
566 			    "%s: found local bound port is %x\n",
567 			    __func__, pcb->local_addr.hvs_port);
568 			break;
569 		}
570 	}
571 
572 	if (found_auto_bound_port == true) {
573 		/* Found available port for auto bound, put on list */
574 		__hvs_insert_socket_on_list(so, HVS_LIST_BOUND);
575 		/* Set VM service ID */
576 		pcb->vm_srv_id = srv_id_template;
577 		set_port_by_srv_id(&pcb->vm_srv_id, pcb->local_addr.hvs_port);
578 		/* Set host service ID and remote port */
579 		pcb->host_srv_id = srv_id_template;
580 		set_port_by_srv_id(&pcb->host_srv_id, raddr->hvs_port);
581 		hvs_addr_set(&pcb->remote_addr, raddr->hvs_port);
582 
583 		/* Change the socket state to SS_ISCONNECTING */
584 		soisconnecting(so);
585 	} else {
586 		HVSOCK_DBG(HVSOCK_DBG_ERR,
587 		    "%s: No local port available for auto bound\n",
588 		    __func__);
589 		error = EADDRINUSE;
590 	}
591 
592 	HVSOCK_DBG(HVSOCK_DBG_INFO, "Connect vm_srv_id is ");
593 	hvsock_print_guid(&pcb->vm_srv_id);
594 	HVSOCK_DBG(HVSOCK_DBG_INFO, "Connect host_srv_id is ");
595 	hvsock_print_guid(&pcb->host_srv_id);
596 
597 out:
598 	mtx_unlock(&hvs_trans_socks_mtx);
599 
600 	if (found_auto_bound_port == true)
601 		 vmbus_req_tl_connect(&pcb->vm_srv_id, &pcb->host_srv_id);
602 
603 	return (error);
604 }
605 
606 int
607 hvs_trans_disconnect(struct socket *so)
608 {
609 	struct hvs_pcb *pcb;
610 
611 	HVSOCK_DBG(HVSOCK_DBG_VERBOSE,
612 	    "%s: HyperV Socket hvs_trans_disconnect called\n", __func__);
613 
614 	(void) hvs_trans_lock();
615 	pcb = so2hvspcb(so);
616 	if (pcb == NULL) {
617 		hvs_trans_unlock();
618 		return (EINVAL);
619 	}
620 
621 	/* If socket is already disconnected, skip this */
622 	if ((so->so_state & SS_ISDISCONNECTED) == 0)
623 		soisdisconnecting(so);
624 
625 	hvs_trans_unlock();
626 
627 	return (0);
628 }
629 
630 #define SBLOCKWAIT(f)	(((f) & MSG_DONTWAIT) ? 0 : SBL_WAIT)
631 struct hvs_callback_arg {
632 	struct uio *uio;
633 	struct sockbuf *sb;
634 };
635 
636 int
637 hvs_trans_soreceive(struct socket *so, struct sockaddr **paddr,
638     struct uio *uio, struct mbuf **mp0, struct mbuf **controlp, int *flagsp)
639 {
640 	struct hvs_pcb *pcb = so2hvspcb(so);
641 	struct sockbuf *sb;
642 	ssize_t orig_resid;
643 	uint32_t canread, to_read;
644 	int flags, error = 0;
645 	struct hvs_callback_arg cbarg;
646 
647 	HVSOCK_DBG(HVSOCK_DBG_VERBOSE,
648 	    "%s: HyperV Socket hvs_trans_soreceive called\n", __func__);
649 
650 	if (so->so_type != SOCK_STREAM)
651 		return (EINVAL);
652 	if (pcb == NULL)
653 		return (EINVAL);
654 
655 	if (flagsp != NULL)
656 		flags = *flagsp &~ MSG_EOR;
657 	else
658 		flags = 0;
659 
660 	if (flags & MSG_PEEK)
661 		return (EOPNOTSUPP);
662 
663 	/* If no space to copy out anything */
664 	if (uio->uio_resid == 0 || uio->uio_rw != UIO_READ)
665 		return (EINVAL);
666 
667 	sb = &so->so_rcv;
668 
669 	orig_resid = uio->uio_resid;
670 
671 	/* Prevent other readers from entering the socket. */
672 	error = sblock(sb, SBLOCKWAIT(flags));
673 	if (error) {
674 		HVSOCK_DBG(HVSOCK_DBG_ERR,
675 		    "%s: sblock returned error = %d\n", __func__, error);
676 		return (error);
677 	}
678 
679 	SOCKBUF_LOCK(sb);
680 
681 	cbarg.uio = uio;
682 	cbarg.sb = sb;
683 	/*
684 	 * If the socket is closing, there might still be some data
685 	 * in rx br to read. However we need to make sure
686 	 * the channel is still open.
687 	 */
688 	if ((sb->sb_state & SBS_CANTRCVMORE) &&
689 	    (so->so_state & SS_ISDISCONNECTED)) {
690 		/* Other thread already closed the channel */
691 		error = EPIPE;
692 		goto out;
693 	}
694 
695 	while (true) {
696 		while (uio->uio_resid > 0 &&
697 		    (canread = hvsock_canread_check(pcb)) > 0) {
698 			to_read = MIN(canread, uio->uio_resid);
699 			HVSOCK_DBG(HVSOCK_DBG_VERBOSE,
700 			    "%s: to_read = %u, skip = %u\n", __func__, to_read,
701 			    (unsigned int)(sizeof(struct hvs_pkt_header) +
702 			    pcb->recv_data_off));
703 
704 			error = vmbus_chan_recv_peek_call(pcb->chan, to_read,
705 			    sizeof(struct hvs_pkt_header) + pcb->recv_data_off,
706 			    hvsock_br_callback, (void *)&cbarg);
707 			/*
708 			 * It is possible socket is disconnected becasue
709 			 * we released lock in hvsock_br_callback. So we
710 			 * need to check the state to make sure it is not
711 			 * disconnected.
712 			 */
713 			if (error || so->so_state & SS_ISDISCONNECTED) {
714 				break;
715 			}
716 
717 			pcb->recv_data_len -= to_read;
718 			pcb->recv_data_off += to_read;
719 		}
720 
721 		if (error)
722 			break;
723 
724 		/* Abort if socket has reported problems. */
725 		if (so->so_error) {
726 			if (so->so_error == ESHUTDOWN &&
727 			    orig_resid > uio->uio_resid) {
728 				/*
729 				 * Although we got a FIN, we also received
730 				 * some data in this round. Delivery it
731 				 * to user.
732 				 */
733 				error = 0;
734 			} else {
735 				if (so->so_error != ESHUTDOWN)
736 					error = so->so_error;
737 			}
738 
739 			break;
740 		}
741 
742 		/* Cannot received more. */
743 		if (sb->sb_state & SBS_CANTRCVMORE)
744 			break;
745 
746 		/* We are done if buffer has been filled */
747 		if (uio->uio_resid == 0)
748 			break;
749 
750 		if (!(flags & MSG_WAITALL) && orig_resid > uio->uio_resid)
751 			break;
752 
753 		/* Buffer ring is empty and we shall not block */
754 		if ((so->so_state & SS_NBIO) ||
755 		    (flags & (MSG_DONTWAIT|MSG_NBIO))) {
756 			if (orig_resid == uio->uio_resid) {
757 				/* We have not read anything */
758 				error = EAGAIN;
759 			}
760 			HVSOCK_DBG(HVSOCK_DBG_VERBOSE,
761 			    "%s: non blocked read return, error %d.\n",
762 			    __func__, error);
763 			break;
764 		}
765 
766 		/*
767 		 * Wait and block until (more) data comes in.
768 		 * Note: Drops the sockbuf lock during wait.
769 		 */
770 		error = sbwait(sb);
771 
772 		if (error)
773 			break;
774 
775 		HVSOCK_DBG(HVSOCK_DBG_VERBOSE,
776 		    "%s: wake up from sbwait, read available is %u\n",
777 		    __func__, vmbus_chan_read_available(pcb->chan));
778 	}
779 
780 out:
781 	SOCKBUF_UNLOCK(sb);
782 
783 	sbunlock(sb);
784 
785 	/* We recieved a FIN in this call */
786 	if (so->so_error == ESHUTDOWN) {
787 		if (so->so_snd.sb_state & SBS_CANTSENDMORE) {
788 			/* Send has already closed */
789 			soisdisconnecting(so);
790 		} else {
791 			/* Just close the receive side */
792 			socantrcvmore(so);
793 		}
794 	}
795 
796 	HVSOCK_DBG(HVSOCK_DBG_VERBOSE,
797 	    "%s: returning error = %d, so_error = %d\n",
798 	    __func__, error, so->so_error);
799 
800 	return (error);
801 }
802 
803 int
804 hvs_trans_sosend(struct socket *so, struct sockaddr *addr, struct uio *uio,
805     struct mbuf *top, struct mbuf *controlp, int flags, struct thread *td)
806 {
807 	struct hvs_pcb *pcb = so2hvspcb(so);
808 	struct sockbuf *sb;
809 	ssize_t orig_resid;
810 	uint32_t canwrite, to_write;
811 	int error = 0;
812 
813 	HVSOCK_DBG(HVSOCK_DBG_VERBOSE,
814 	    "%s: HyperV Socket hvs_trans_sosend called, uio_resid = %zd\n",
815 	    __func__, uio->uio_resid);
816 
817 	if (so->so_type != SOCK_STREAM)
818 		return (EINVAL);
819 	if (pcb == NULL)
820 		return (EINVAL);
821 
822 	/* If nothing to send */
823 	if (uio->uio_resid == 0 || uio->uio_rw != UIO_WRITE)
824 		return (EINVAL);
825 
826 	sb = &so->so_snd;
827 
828 	orig_resid = uio->uio_resid;
829 
830 	/* Prevent other writers from entering the socket. */
831 	error = sblock(sb, SBLOCKWAIT(flags));
832 	if (error) {
833 		HVSOCK_DBG(HVSOCK_DBG_ERR,
834 		    "%s: sblock returned error = %d\n", __func__, error);
835 		return (error);
836 	}
837 
838 	SOCKBUF_LOCK(sb);
839 
840 	if ((sb->sb_state & SBS_CANTSENDMORE) ||
841 	    so->so_error == ESHUTDOWN) {
842 		error = EPIPE;
843 		goto out;
844 	}
845 
846 	while (uio->uio_resid > 0) {
847 		canwrite = hvsock_canwrite_check(pcb);
848 		if (canwrite == 0) {
849 			/* We have sent some data */
850 			if (orig_resid > uio->uio_resid)
851 				break;
852 			/*
853 			 * We have not sent any data and it is
854 			 * non-blocked io
855 			 */
856 			if (so->so_state & SS_NBIO ||
857 			    (flags & (MSG_NBIO | MSG_DONTWAIT)) != 0) {
858 				error = EWOULDBLOCK;
859 				break;
860 			} else {
861 				/*
862 				 * We are here because there is no space on
863 				 * send buffer ring. Signal the other side
864 				 * to read and free more space.
865 				 * Sleep wait until space avaiable to send
866 				 * Note: Drops the sockbuf lock during wait.
867 				 */
868 				error = sbwait(sb);
869 
870 				if (error)
871 					break;
872 
873 				HVSOCK_DBG(HVSOCK_DBG_VERBOSE,
874 				    "%s: wake up from sbwait, space avail on "
875 				    "tx ring is %u\n",
876 				    __func__,
877 				    vmbus_chan_write_available(pcb->chan));
878 
879 				continue;
880 			}
881 		}
882 		to_write = MIN(canwrite, uio->uio_resid);
883 		to_write = MIN(to_write, HVSOCK_SEND_BUF_SZ);
884 
885 		HVSOCK_DBG(HVSOCK_DBG_VERBOSE,
886 		    "%s: canwrite is %u, to_write = %u\n", __func__,
887 		    canwrite, to_write);
888 		error = hvsock_send_data(pcb->chan, uio, to_write, sb);
889 
890 		if (error)
891 			break;
892 	}
893 
894 out:
895 	SOCKBUF_UNLOCK(sb);
896 	sbunlock(sb);
897 
898 	return (error);
899 }
900 
901 int
902 hvs_trans_peeraddr(struct socket *so, struct sockaddr **nam)
903 {
904 	struct hvs_pcb *pcb = so2hvspcb(so);
905 
906 	HVSOCK_DBG(HVSOCK_DBG_VERBOSE,
907 	    "%s: HyperV Socket hvs_trans_peeraddr called\n", __func__);
908 
909 	if (pcb == NULL)
910 		return (EINVAL);
911 
912 	*nam = sodupsockaddr((struct sockaddr *) &pcb->remote_addr, M_NOWAIT);
913 
914 	return ((*nam == NULL)? ENOMEM : 0);
915 }
916 
917 int
918 hvs_trans_sockaddr(struct socket *so, struct sockaddr **nam)
919 {
920 	struct hvs_pcb *pcb = so2hvspcb(so);
921 
922 	HVSOCK_DBG(HVSOCK_DBG_VERBOSE,
923 	    "%s: HyperV Socket hvs_trans_sockaddr called\n", __func__);
924 
925 	if (pcb == NULL)
926 		return (EINVAL);
927 
928 	*nam = sodupsockaddr((struct sockaddr *) &pcb->local_addr, M_NOWAIT);
929 
930 	return ((*nam == NULL)? ENOMEM : 0);
931 }
932 
933 void
934 hvs_trans_close(struct socket *so)
935 {
936 	struct hvs_pcb *pcb;
937 
938 	HVSOCK_DBG(HVSOCK_DBG_VERBOSE,
939 	    "%s: HyperV Socket hvs_trans_close called\n", __func__);
940 
941 	(void) hvs_trans_lock();
942 	pcb = so2hvspcb(so);
943 	if (!pcb) {
944 		hvs_trans_unlock();
945 		return;
946 	}
947 
948 	if (so->so_state & SS_ISCONNECTED) {
949 		/* Send a FIN to peer */
950 		HVSOCK_DBG(HVSOCK_DBG_VERBOSE,
951 		    "%s: hvs_trans_close sending a FIN to host\n", __func__);
952 		(void) hvsock_send_data(pcb->chan, NULL, 0, NULL);
953 	}
954 
955 	if (so->so_state &
956 	    (SS_ISCONNECTED|SS_ISCONNECTING|SS_ISDISCONNECTING))
957 		soisdisconnected(so);
958 
959 	pcb->chan = NULL;
960 	pcb->so = NULL;
961 
962 	if (SOLISTENING(so)) {
963 		mtx_lock(&hvs_trans_socks_mtx);
964 		/* Remove from bound list */
965 		__hvs_remove_socket_from_list(so, HVS_LIST_BOUND);
966 		mtx_unlock(&hvs_trans_socks_mtx);
967 	}
968 
969 	hvs_trans_unlock();
970 
971 	return;
972 }
973 
974 void
975 hvs_trans_abort(struct socket *so)
976 {
977 	struct hvs_pcb *pcb = so2hvspcb(so);
978 
979 	HVSOCK_DBG(HVSOCK_DBG_VERBOSE,
980 	    "%s: HyperV Socket hvs_trans_abort called\n", __func__);
981 
982 	(void) hvs_trans_lock();
983 	if (pcb == NULL) {
984 		hvs_trans_unlock();
985 		return;
986 	}
987 
988 	if (SOLISTENING(so)) {
989 		mtx_lock(&hvs_trans_socks_mtx);
990 		/* Remove from bound list */
991 		__hvs_remove_socket_from_list(so, HVS_LIST_BOUND);
992 		mtx_unlock(&hvs_trans_socks_mtx);
993 	}
994 
995 	if (so->so_state & SS_ISCONNECTED) {
996 		(void) sodisconnect(so);
997 	}
998 	hvs_trans_unlock();
999 
1000 	return;
1001 }
1002 
1003 int
1004 hvs_trans_shutdown(struct socket *so)
1005 {
1006 	struct hvs_pcb *pcb = so2hvspcb(so);
1007 	struct sockbuf *sb;
1008 
1009 	HVSOCK_DBG(HVSOCK_DBG_VERBOSE,
1010 	    "%s: HyperV Socket hvs_trans_shutdown called\n", __func__);
1011 
1012 	if (pcb == NULL)
1013 		return (EINVAL);
1014 
1015 	/*
1016 	 * Only get called with the shutdown method is SHUT_WR or
1017 	 * SHUT_RDWR.
1018 	 * When the method is SHUT_RD or SHUT_RDWR, the caller
1019 	 * already set the SBS_CANTRCVMORE on receive side socket
1020 	 * buffer.
1021 	 */
1022 	if ((so->so_rcv.sb_state & SBS_CANTRCVMORE) == 0) {
1023 		/*
1024 		 * SHUT_WR only case.
1025 		 * Receive side is still open. Just close
1026 		 * the send side.
1027 		 */
1028 		socantsendmore(so);
1029 	} else {
1030 		/* SHUT_RDWR case */
1031 		if (so->so_state & SS_ISCONNECTED) {
1032 			/* Send a FIN to peer */
1033 			sb = &so->so_snd;
1034 			SOCKBUF_LOCK(sb);
1035 			(void) hvsock_send_data(pcb->chan, NULL, 0, sb);
1036 			SOCKBUF_UNLOCK(sb);
1037 
1038 			soisdisconnecting(so);
1039 		}
1040 	}
1041 
1042 	return (0);
1043 }
1044 
1045 /* In the VM, we support Hyper-V Sockets with AF_HYPERV, and the endpoint is
1046  * <port> (see struct sockaddr_hvs).
1047  *
1048  * On the host, Hyper-V Sockets are supported by Winsock AF_HYPERV:
1049  * https://docs.microsoft.com/en-us/virtualization/hyper-v-on-windows/user-
1050  * guide/make-integration-service, and the endpoint is <VmID, ServiceId> with
1051  * the below sockaddr:
1052  *
1053  * struct SOCKADDR_HV
1054  * {
1055  *    ADDRESS_FAMILY Family;
1056  *    USHORT Reserved;
1057  *    GUID VmId;
1058  *    GUID ServiceId;
1059  * };
1060  * Note: VmID is not used by FreeBSD VM and actually it isn't transmitted via
1061  * VMBus, because here it's obvious the host and the VM can easily identify
1062  * each other. Though the VmID is useful on the host, especially in the case
1063  * of Windows container, FreeBSD VM doesn't need it at all.
1064  *
1065  * To be compatible with similar infrastructure in Linux VMs, we have
1066  * to limit the available GUID space of SOCKADDR_HV so that we can create
1067  * a mapping between FreeBSD AF_HYPERV port and SOCKADDR_HV Service GUID.
1068  * The rule of writing Hyper-V Sockets apps on the host and in FreeBSD VM is:
1069  *
1070  ****************************************************************************
1071  * The only valid Service GUIDs, from the perspectives of both the host and *
1072  * FreeBSD VM, that can be connected by the other end, must conform to this *
1073  * format: <port>-facb-11e6-bd58-64006a7986d3.                              *
1074  ****************************************************************************
1075  *
1076  * When we write apps on the host to connect(), the GUID ServiceID is used.
1077  * When we write apps in FreeBSD VM to connect(), we only need to specify the
1078  * port and the driver will form the GUID and use that to request the host.
1079  *
1080  * From the perspective of FreeBSD VM, the remote ephemeral port (i.e. the
1081  * auto-generated remote port for a connect request initiated by the host's
1082  * connect()) is set to HVADDR_PORT_UNKNOWN, which is not realy used on the
1083  * FreeBSD guest.
1084  */
1085 
1086 /*
1087  * Older HyperV hosts (vmbus version 'VMBUS_VERSION_WIN10' or before)
1088  * restricts HyperV socket ring buffer size to six 4K pages. Newer
1089  * HyperV hosts doen't have this limit.
1090  */
1091 #define HVS_RINGBUF_RCV_SIZE	(PAGE_SIZE * 6)
1092 #define HVS_RINGBUF_SND_SIZE	(PAGE_SIZE * 6)
1093 #define HVS_RINGBUF_MAX_SIZE	(PAGE_SIZE * 64)
1094 
1095 struct hvsock_sc {
1096 	device_t		dev;
1097 	struct hvs_pcb		*pcb;
1098 	struct vmbus_channel	*channel;
1099 };
1100 
1101 static bool
1102 hvsock_chan_readable(struct vmbus_channel *chan)
1103 {
1104 	uint32_t readable = vmbus_chan_read_available(chan);
1105 
1106 	return (readable >= HVSOCK_PKT_LEN(0));
1107 }
1108 
1109 static void
1110 hvsock_chan_cb(struct vmbus_channel *chan, void *context)
1111 {
1112 	struct hvs_pcb *pcb = (struct hvs_pcb *) context;
1113 	struct socket *so;
1114 	uint32_t canwrite;
1115 
1116 	HVSOCK_DBG(HVSOCK_DBG_VERBOSE,
1117 	    "%s: host send us a wakeup on rb data, pcb = %p\n",
1118 	    __func__, pcb);
1119 
1120 	/*
1121 	 * Check if the socket is still attached and valid.
1122 	 * Here we know channel is still open. Need to make
1123 	 * sure the socket has not been closed or freed.
1124 	 */
1125 	(void) hvs_trans_lock();
1126 	so = hsvpcb2so(pcb);
1127 
1128 	if (pcb->chan != NULL && so != NULL) {
1129 		/*
1130 		 * Wake up reader if there are data to read.
1131 		 */
1132 		SOCKBUF_LOCK(&(so)->so_rcv);
1133 
1134 		HVSOCK_DBG(HVSOCK_DBG_VERBOSE,
1135 		    "%s: read available = %u\n", __func__,
1136 		    vmbus_chan_read_available(pcb->chan));
1137 
1138 		if (hvsock_chan_readable(pcb->chan))
1139 			sorwakeup_locked(so);
1140 		else
1141 			SOCKBUF_UNLOCK(&(so)->so_rcv);
1142 
1143 		/*
1144 		 * Wake up sender if space becomes available to write.
1145 		 */
1146 		SOCKBUF_LOCK(&(so)->so_snd);
1147 		canwrite = hvsock_canwrite_check(pcb);
1148 
1149 		HVSOCK_DBG(HVSOCK_DBG_VERBOSE,
1150 		    "%s: canwrite = %u\n", __func__, canwrite);
1151 
1152 		if (canwrite > 0) {
1153 			sowwakeup_locked(so);
1154 		} else {
1155 			SOCKBUF_UNLOCK(&(so)->so_snd);
1156 		}
1157 	}
1158 
1159 	hvs_trans_unlock();
1160 
1161 	return;
1162 }
1163 
1164 static int
1165 hvsock_br_callback(void *datap, int cplen, void *cbarg)
1166 {
1167 	struct hvs_callback_arg *arg = (struct hvs_callback_arg *)cbarg;
1168 	struct uio *uio = arg->uio;
1169 	struct sockbuf *sb = arg->sb;
1170 	int error = 0;
1171 
1172 	if (cbarg == NULL || datap == NULL)
1173 		return (EINVAL);
1174 
1175 	HVSOCK_DBG(HVSOCK_DBG_VERBOSE,
1176 	    "%s: called, uio_rw = %s, uio_resid = %zd, cplen = %u, "
1177 	    "datap = %p\n",
1178 	    __func__, (uio->uio_rw == UIO_READ) ? "read from br":"write to br",
1179 	    uio->uio_resid, cplen, datap);
1180 
1181 	if (sb)
1182 		SOCKBUF_UNLOCK(sb);
1183 
1184 	error = uiomove(datap, cplen, uio);
1185 
1186 	if (sb)
1187 		SOCKBUF_LOCK(sb);
1188 
1189 	HVSOCK_DBG(HVSOCK_DBG_VERBOSE,
1190 	    "%s: after uiomove, uio_resid = %zd, error = %d\n",
1191 	    __func__, uio->uio_resid, error);
1192 
1193 	return (error);
1194 }
1195 
1196 static int
1197 hvsock_send_data(struct vmbus_channel *chan, struct uio *uio,
1198     uint32_t to_write, struct sockbuf *sb)
1199 {
1200 	struct hvs_pkt_header hvs_pkt;
1201 	int hvs_pkthlen, hvs_pktlen, pad_pktlen, hlen, error = 0;
1202 	uint64_t pad = 0;
1203 	struct iovec iov[3];
1204 	struct hvs_callback_arg cbarg;
1205 
1206 	if (chan == NULL)
1207 		return (ENOTCONN);
1208 
1209 	hlen = sizeof(struct vmbus_chanpkt_hdr);
1210 	hvs_pkthlen = sizeof(struct hvs_pkt_header);
1211 	hvs_pktlen = hvs_pkthlen + to_write;
1212 	pad_pktlen = VMBUS_CHANPKT_TOTLEN(hvs_pktlen);
1213 
1214 	HVSOCK_DBG(HVSOCK_DBG_VERBOSE,
1215 	    "%s: hlen = %u, hvs_pkthlen = %u, hvs_pktlen = %u, "
1216 	    "pad_pktlen = %u, data_len = %u\n",
1217 	    __func__, hlen, hvs_pkthlen, hvs_pktlen, pad_pktlen, to_write);
1218 
1219 	hvs_pkt.chan_pkt_hdr.cph_type = VMBUS_CHANPKT_TYPE_INBAND;
1220 	hvs_pkt.chan_pkt_hdr.cph_flags = 0;
1221 	VMBUS_CHANPKT_SETLEN(hvs_pkt.chan_pkt_hdr.cph_hlen, hlen);
1222 	VMBUS_CHANPKT_SETLEN(hvs_pkt.chan_pkt_hdr.cph_tlen, pad_pktlen);
1223 	hvs_pkt.chan_pkt_hdr.cph_xactid = 0;
1224 
1225 	hvs_pkt.vmpipe_pkt_hdr.vmpipe_pkt_type = 1;
1226 	hvs_pkt.vmpipe_pkt_hdr.vmpipe_data_size = to_write;
1227 
1228 	cbarg.uio = uio;
1229 	cbarg.sb = sb;
1230 
1231 	if (uio && to_write > 0) {
1232 		iov[0].iov_base = &hvs_pkt;
1233 		iov[0].iov_len = hvs_pkthlen;
1234 		iov[1].iov_base = NULL;
1235 		iov[1].iov_len = to_write;
1236 		iov[2].iov_base = &pad;
1237 		iov[2].iov_len = pad_pktlen - hvs_pktlen;
1238 
1239 		error = vmbus_chan_iov_send(chan, iov, 3,
1240 		    hvsock_br_callback, &cbarg);
1241 	} else {
1242 		if (to_write == 0) {
1243 			iov[0].iov_base = &hvs_pkt;
1244 			iov[0].iov_len = hvs_pkthlen;
1245 			iov[1].iov_base = &pad;
1246 			iov[1].iov_len = pad_pktlen - hvs_pktlen;
1247 			error = vmbus_chan_iov_send(chan, iov, 2, NULL, NULL);
1248 		}
1249 	}
1250 
1251 	if (error) {
1252 		HVSOCK_DBG(HVSOCK_DBG_VERBOSE,
1253 		    "%s: error = %d\n", __func__, error);
1254 	}
1255 
1256 	return (error);
1257 }
1258 
1259 /*
1260  * Check if we have data on current ring buffer to read
1261  * or not. If not, advance the ring buffer read index to
1262  * next packet. Update the recev_data_len and recev_data_off
1263  * to new value.
1264  * Return the number of bytes can read.
1265  */
1266 static uint32_t
1267 hvsock_canread_check(struct hvs_pcb *pcb)
1268 {
1269 	uint32_t advance;
1270 	uint32_t tlen, hlen, dlen;
1271 	uint32_t bytes_canread = 0;
1272 	int error;
1273 
1274 	if (pcb == NULL || pcb->chan == NULL) {
1275 		pcb->so->so_error = EIO;
1276 		return (0);
1277 	}
1278 
1279 	/* Still have data not read yet on current packet */
1280 	if (pcb->recv_data_len > 0)
1281 		return (pcb->recv_data_len);
1282 
1283 	if (pcb->rb_init)
1284 		advance =
1285 		    VMBUS_CHANPKT_GETLEN(pcb->hvs_pkt.chan_pkt_hdr.cph_tlen);
1286 	else
1287 		advance = 0;
1288 
1289 	bytes_canread = vmbus_chan_read_available(pcb->chan);
1290 
1291 	HVSOCK_DBG(HVSOCK_DBG_VERBOSE,
1292 	    "%s: bytes_canread on br = %u, advance = %u\n",
1293 	    __func__, bytes_canread, advance);
1294 
1295 	if (pcb->rb_init && bytes_canread == (advance + sizeof(uint64_t))) {
1296 		/*
1297 		 * Nothing to read. Need to advance the rindex before
1298 		 * calling sbwait, so host knows to wake us up when data
1299 		 * is available to read on rb.
1300 		 */
1301 		error = vmbus_chan_recv_idxadv(pcb->chan, advance);
1302 		if (error) {
1303 			HVSOCK_DBG(HVSOCK_DBG_ERR,
1304 			    "%s: after calling vmbus_chan_recv_idxadv, "
1305 			    "got error = %d\n",  __func__, error);
1306 			return (0);
1307 		} else {
1308 			pcb->rb_init = false;
1309 			pcb->recv_data_len = 0;
1310 			pcb->recv_data_off = 0;
1311 			bytes_canread = vmbus_chan_read_available(pcb->chan);
1312 
1313 			HVSOCK_DBG(HVSOCK_DBG_VERBOSE,
1314 			    "%s: advanced %u bytes, "
1315 			    " bytes_canread on br now = %u\n",
1316 			    __func__, advance, bytes_canread);
1317 
1318 			if (bytes_canread == 0)
1319 				return (0);
1320 			else
1321 				advance = 0;
1322 		}
1323 	}
1324 
1325 	if (bytes_canread <
1326 	    advance + (sizeof(struct hvs_pkt_header) + sizeof(uint64_t)))
1327 		return (0);
1328 
1329 	error = vmbus_chan_recv_peek(pcb->chan, &pcb->hvs_pkt,
1330 	    sizeof(struct hvs_pkt_header), advance);
1331 
1332 	/* Don't have anything to read */
1333 	if (error) {
1334 		HVSOCK_DBG(HVSOCK_DBG_VERBOSE,
1335 		    "%s: after calling vmbus_chan_recv_peek, got error = %d\n",
1336 		    __func__, error);
1337 		return (0);
1338 	}
1339 
1340 	/*
1341 	 * We just read in a new packet header. Do some sanity checks.
1342 	 */
1343 	tlen = VMBUS_CHANPKT_GETLEN(pcb->hvs_pkt.chan_pkt_hdr.cph_tlen);
1344 	hlen = VMBUS_CHANPKT_GETLEN(pcb->hvs_pkt.chan_pkt_hdr.cph_hlen);
1345 	dlen = pcb->hvs_pkt.vmpipe_pkt_hdr.vmpipe_data_size;
1346 	if (__predict_false(hlen < sizeof(struct vmbus_chanpkt_hdr)) ||
1347 	    __predict_false(hlen > tlen) ||
1348 	    __predict_false(tlen < dlen + sizeof(struct hvs_pkt_header))) {
1349 		HVSOCK_DBG(HVSOCK_DBG_VERBOSE,
1350 		    "invalid tlen(%u), hlen(%u) or dlen(%u)\n",
1351 		    tlen, hlen, dlen);
1352 		pcb->so->so_error = EIO;
1353 		return (0);
1354 	}
1355 	if (pcb->rb_init == false)
1356 		pcb->rb_init = true;
1357 
1358 	HVSOCK_DBG(HVSOCK_DBG_VERBOSE,
1359 	    "Got new pkt tlen(%u), hlen(%u) or dlen(%u)\n",
1360 	    tlen, hlen, dlen);
1361 
1362 	/* The other side has sent a close FIN */
1363 	if (dlen == 0) {
1364 		HVSOCK_DBG(HVSOCK_DBG_VERBOSE,
1365 		    "%s: Received FIN from other side\n", __func__);
1366 		/* inform the caller by seting so_error to ESHUTDOWN */
1367 		pcb->so->so_error = ESHUTDOWN;
1368 	}
1369 
1370 	HVSOCK_DBG(HVSOCK_DBG_VERBOSE,
1371 	    "%s: canread on receive ring is %u \n", __func__, dlen);
1372 
1373 	pcb->recv_data_len = dlen;
1374 	pcb->recv_data_off = 0;
1375 
1376 	return (pcb->recv_data_len);
1377 }
1378 
1379 static uint32_t
1380 hvsock_canwrite_check(struct hvs_pcb *pcb)
1381 {
1382 	uint32_t writeable;
1383 	uint32_t ret;
1384 
1385 	if (pcb == NULL || pcb->chan == NULL)
1386 		return (0);
1387 
1388 	writeable = vmbus_chan_write_available(pcb->chan);
1389 
1390 	/*
1391 	 * We must always reserve a 0-length-payload packet for the FIN.
1392 	 */
1393 	HVSOCK_DBG(HVSOCK_DBG_VERBOSE,
1394 	    "%s: writeable is %u, should be greater than %ju\n",
1395 	    __func__, writeable,
1396 	    (uintmax_t)(HVSOCK_PKT_LEN(1) + HVSOCK_PKT_LEN(0)));
1397 
1398 	if (writeable < HVSOCK_PKT_LEN(1) + HVSOCK_PKT_LEN(0)) {
1399 		/*
1400 		 * The Tx ring seems full.
1401 		 */
1402 		return (0);
1403 	}
1404 
1405 	ret = writeable - HVSOCK_PKT_LEN(0) - HVSOCK_PKT_LEN(0);
1406 
1407 	HVSOCK_DBG(HVSOCK_DBG_VERBOSE,
1408 	    "%s: available size is %u\n", __func__, rounddown2(ret, 8));
1409 
1410 	return (rounddown2(ret, 8));
1411 }
1412 
1413 static void
1414 hvsock_set_chan_pending_send_size(struct vmbus_channel *chan)
1415 {
1416 	vmbus_chan_set_pending_send_size(chan,
1417 	    HVSOCK_PKT_LEN(HVSOCK_SEND_BUF_SZ));
1418 }
1419 
1420 static int
1421 hvsock_open_channel(struct vmbus_channel *chan, struct socket *so)
1422 {
1423 	unsigned int rcvbuf, sndbuf;
1424 	struct hvs_pcb *pcb = so2hvspcb(so);
1425 	int ret;
1426 
1427 	if (vmbus_current_version < VMBUS_VERSION_WIN10_V5) {
1428 		sndbuf = HVS_RINGBUF_SND_SIZE;
1429 		rcvbuf = HVS_RINGBUF_RCV_SIZE;
1430 	} else {
1431 		sndbuf = MAX(so->so_snd.sb_hiwat, HVS_RINGBUF_SND_SIZE);
1432 		sndbuf = MIN(sndbuf, HVS_RINGBUF_MAX_SIZE);
1433 		sndbuf = rounddown2(sndbuf, PAGE_SIZE);
1434 		rcvbuf = MAX(so->so_rcv.sb_hiwat, HVS_RINGBUF_RCV_SIZE);
1435 		rcvbuf = MIN(rcvbuf, HVS_RINGBUF_MAX_SIZE);
1436 		rcvbuf = rounddown2(rcvbuf, PAGE_SIZE);
1437 	}
1438 
1439 	/*
1440 	 * Can only read whatever user provided size of data
1441 	 * from ring buffer. Turn off batched reading.
1442 	 */
1443 	vmbus_chan_set_readbatch(chan, false);
1444 
1445 	ret = vmbus_chan_open(chan, sndbuf, rcvbuf, NULL, 0,
1446 	    hvsock_chan_cb, pcb);
1447 
1448 	if (ret != 0) {
1449 		HVSOCK_DBG(HVSOCK_DBG_ERR,
1450 		    "%s: failed to open hvsock channel, sndbuf = %u, "
1451 		    "rcvbuf = %u\n", __func__, sndbuf, rcvbuf);
1452 	} else {
1453 		HVSOCK_DBG(HVSOCK_DBG_INFO,
1454 		    "%s: hvsock channel opened, sndbuf = %u, i"
1455 		    "rcvbuf = %u\n", __func__, sndbuf, rcvbuf);
1456 		/*
1457 		 * Se the pending send size so to receive wakeup
1458 		 * signals from host when there is enough space on
1459 		 * rx buffer ring to write.
1460 		 */
1461 		hvsock_set_chan_pending_send_size(chan);
1462 	}
1463 
1464 	return ret;
1465 }
1466 
1467 /*
1468  * Guest is listening passively on the socket. Open channel and
1469  * create a new socket for the conneciton.
1470  */
1471 static void
1472 hvsock_open_conn_passive(struct vmbus_channel *chan, struct socket *so,
1473     struct hvsock_sc *sc)
1474 {
1475 	struct socket *new_so;
1476 	struct hvs_pcb *new_pcb, *pcb;
1477 	int error;
1478 
1479 	/* Do nothing if socket is not listening */
1480 	if (!SOLISTENING(so)) {
1481 		HVSOCK_DBG(HVSOCK_DBG_ERR,
1482 		    "%s: socket is not a listening one\n", __func__);
1483 		return;
1484 	}
1485 
1486 	/*
1487 	 * Create a new socket. This will call pru_attach to complete
1488 	 * the socket initialization and put the new socket onto
1489 	 * listening socket's sol_incomp list, waiting to be promoted
1490 	 * to sol_comp list.
1491 	 * The new socket created has ref count 0. There is no other
1492 	 * thread that changes the state of this new one at the
1493 	 * moment, so we don't need to hold its lock while opening
1494 	 * channel and filling out its pcb information.
1495 	 */
1496 	new_so = sonewconn(so, 0);
1497 	if (!new_so)
1498 		HVSOCK_DBG(HVSOCK_DBG_ERR,
1499 		    "%s: creating new socket failed\n", __func__);
1500 
1501 	/*
1502 	 * Now open the vmbus channel. If it fails, the socket will be
1503 	 * on the listening socket's sol_incomp queue until it is
1504 	 * replaced and aborted.
1505 	 */
1506 	error = hvsock_open_channel(chan, new_so);
1507 	if (error) {
1508 		new_so->so_error = error;
1509 		return;
1510 	}
1511 
1512 	pcb = so->so_pcb;
1513 	new_pcb = new_so->so_pcb;
1514 
1515 	hvs_addr_set(&(new_pcb->local_addr), pcb->local_addr.hvs_port);
1516 	/* Remote port is unknown to guest in this type of conneciton */
1517 	hvs_addr_set(&(new_pcb->remote_addr), HVADDR_PORT_UNKNOWN);
1518 	new_pcb->chan = chan;
1519 	new_pcb->recv_data_len = 0;
1520 	new_pcb->recv_data_off = 0;
1521 	new_pcb->rb_init = false;
1522 
1523 	new_pcb->vm_srv_id = *vmbus_chan_guid_type(chan);
1524 	new_pcb->host_srv_id = *vmbus_chan_guid_inst(chan);
1525 
1526 	hvs_insert_socket_on_list(new_so, HVS_LIST_CONNECTED);
1527 
1528 	sc->pcb = new_pcb;
1529 
1530 	/*
1531 	 * Change the socket state to SS_ISCONNECTED. This will promote
1532 	 * the socket to sol_comp queue and wake up the thread which
1533 	 * is accepting connection.
1534 	 */
1535 	soisconnected(new_so);
1536 }
1537 
1538 
1539 /*
1540  * Guest is actively connecting to host.
1541  */
1542 static void
1543 hvsock_open_conn_active(struct vmbus_channel *chan, struct socket *so)
1544 {
1545 	struct hvs_pcb *pcb;
1546 	int error;
1547 
1548 	error = hvsock_open_channel(chan, so);
1549 	if (error) {
1550 		so->so_error = error;
1551 		return;
1552 	}
1553 
1554 	pcb = so->so_pcb;
1555 	pcb->chan = chan;
1556 	pcb->recv_data_len = 0;
1557 	pcb->recv_data_off = 0;
1558 	pcb->rb_init = false;
1559 
1560 	mtx_lock(&hvs_trans_socks_mtx);
1561 	__hvs_remove_socket_from_list(so, HVS_LIST_BOUND);
1562 	__hvs_insert_socket_on_list(so, HVS_LIST_CONNECTED);
1563 	mtx_unlock(&hvs_trans_socks_mtx);
1564 
1565 	/*
1566 	 * Change the socket state to SS_ISCONNECTED. This will wake up
1567 	 * the thread sleeping in connect call.
1568 	 */
1569 	soisconnected(so);
1570 }
1571 
1572 static void
1573 hvsock_open_connection(struct vmbus_channel *chan, struct hvsock_sc *sc)
1574 {
1575 	struct hyperv_guid *inst_guid, *type_guid;
1576 	bool conn_from_host;
1577 	struct sockaddr_hvs addr;
1578 	struct socket *so;
1579 	struct hvs_pcb *pcb;
1580 
1581 	type_guid = (struct hyperv_guid *) vmbus_chan_guid_type(chan);
1582 	inst_guid = (struct hyperv_guid *) vmbus_chan_guid_inst(chan);
1583 	conn_from_host = vmbus_chan_is_hvs_conn_from_host(chan);
1584 
1585 	HVSOCK_DBG(HVSOCK_DBG_INFO, "type_guid is ");
1586 	hvsock_print_guid(type_guid);
1587 	HVSOCK_DBG(HVSOCK_DBG_INFO, "inst_guid is ");
1588 	hvsock_print_guid(inst_guid);
1589 	HVSOCK_DBG(HVSOCK_DBG_INFO, "connection %s host\n",
1590 	    (conn_from_host == true ) ? "from" : "to");
1591 
1592 	/*
1593 	 * The listening port should be in [0, MAX_LISTEN_PORT]
1594 	 */
1595 	if (!is_valid_srv_id(type_guid))
1596 		return;
1597 
1598 	/*
1599 	 * There should be a bound socket already created no matter
1600 	 * it is a passive or active connection.
1601 	 * For host initiated connection (passive on guest side),
1602 	 * the  type_guid contains the port which guest is bound and
1603 	 * listening.
1604 	 * For the guest initiated connection (active on guest side),
1605 	 * the inst_guid contains the port that guest has auto bound
1606 	 * to.
1607 	 */
1608 	hvs_addr_init(&addr, conn_from_host ? type_guid : inst_guid);
1609 	so = hvs_find_socket_on_list(&addr, HVS_LIST_BOUND);
1610 	if (!so) {
1611 		HVSOCK_DBG(HVSOCK_DBG_ERR,
1612 		    "%s: no bound socket found for port %u\n",
1613 		    __func__, addr.hvs_port);
1614 		return;
1615 	}
1616 
1617 	if (conn_from_host) {
1618 		hvsock_open_conn_passive(chan, so, sc);
1619 	} else {
1620 		(void) hvs_trans_lock();
1621 		pcb = so->so_pcb;
1622 		if (pcb && pcb->so) {
1623 			sc->pcb = so2hvspcb(so);
1624 			hvsock_open_conn_active(chan, so);
1625 		} else {
1626 			HVSOCK_DBG(HVSOCK_DBG_VERBOSE,
1627 			    "%s: channel detached before open\n", __func__);
1628 		}
1629 		hvs_trans_unlock();
1630 	}
1631 
1632 }
1633 
1634 static int
1635 hvsock_probe(device_t dev)
1636 {
1637 	struct vmbus_channel *channel = vmbus_get_channel(dev);
1638 
1639 	if (!channel || !vmbus_chan_is_hvs(channel)) {
1640 		HVSOCK_DBG(HVSOCK_DBG_VERBOSE,
1641 		    "hvsock_probe called but not a hvsock channel id %u\n",
1642 		    vmbus_chan_id(channel));
1643 
1644 		return ENXIO;
1645 	} else {
1646 		HVSOCK_DBG(HVSOCK_DBG_VERBOSE,
1647 		    "hvsock_probe got a hvsock channel id %u\n",
1648 		    vmbus_chan_id(channel));
1649 
1650 		return BUS_PROBE_DEFAULT;
1651 	}
1652 }
1653 
1654 static int
1655 hvsock_attach(device_t dev)
1656 {
1657 	struct vmbus_channel *channel = vmbus_get_channel(dev);
1658 	struct hvsock_sc *sc = (struct hvsock_sc *)device_get_softc(dev);
1659 
1660 	HVSOCK_DBG(HVSOCK_DBG_VERBOSE, "hvsock_attach called.\n");
1661 
1662 	hvsock_open_connection(channel, sc);
1663 
1664 	/*
1665 	 * Always return success. On error the host will rescind the device
1666 	 * in 30 seconds and we can do cleanup at that time in
1667 	 * vmbus_chan_msgproc_chrescind().
1668 	 */
1669 	return (0);
1670 }
1671 
1672 static int
1673 hvsock_detach(device_t dev)
1674 {
1675 	struct hvsock_sc *sc = (struct hvsock_sc *)device_get_softc(dev);
1676 	struct socket *so;
1677 	int error, retry;
1678 
1679 	if (bootverbose)
1680 		device_printf(dev, "hvsock_detach called.\n");
1681 
1682 	HVSOCK_DBG(HVSOCK_DBG_VERBOSE, "hvsock_detach called.\n");
1683 
1684 	if (sc->pcb != NULL) {
1685 		(void) hvs_trans_lock();
1686 
1687 		so = hsvpcb2so(sc->pcb);
1688 		if (so) {
1689 			/* Close the connection */
1690 			if (so->so_state &
1691 			    (SS_ISCONNECTED|SS_ISCONNECTING|SS_ISDISCONNECTING))
1692 				soisdisconnected(so);
1693 		}
1694 
1695 		mtx_lock(&hvs_trans_socks_mtx);
1696 		__hvs_remove_pcb_from_list(sc->pcb,
1697 		    HVS_LIST_BOUND | HVS_LIST_CONNECTED);
1698 		mtx_unlock(&hvs_trans_socks_mtx);
1699 
1700 		/*
1701 		 * Close channel while no reader and sender are working
1702 		 * on the buffer rings.
1703 		 */
1704 		if (so) {
1705 			retry = 0;
1706 			while ((error = sblock(&so->so_rcv, 0)) ==
1707 			    EWOULDBLOCK) {
1708 				/*
1709 				 * Someone is reading, rx br is busy
1710 				 */
1711 				soisdisconnected(so);
1712 				DELAY(500);
1713 				HVSOCK_DBG(HVSOCK_DBG_VERBOSE,
1714 				    "waiting for rx reader to exit, "
1715 				    "retry = %d\n", retry++);
1716 			}
1717 			retry = 0;
1718 			while ((error = sblock(&so->so_snd, 0)) ==
1719 			    EWOULDBLOCK) {
1720 				/*
1721 				 * Someone is sending, tx br is busy
1722 				 */
1723 				soisdisconnected(so);
1724 				DELAY(500);
1725 				HVSOCK_DBG(HVSOCK_DBG_VERBOSE,
1726 				    "waiting for tx sender to exit, "
1727 				    "retry = %d\n", retry++);
1728 			}
1729 		}
1730 
1731 
1732 		bzero(sc->pcb, sizeof(struct hvs_pcb));
1733 		free(sc->pcb, M_HVSOCK);
1734 		sc->pcb = NULL;
1735 
1736 		if (so) {
1737 			sbunlock(&so->so_rcv);
1738 			sbunlock(&so->so_snd);
1739 			so->so_pcb = NULL;
1740 		}
1741 
1742 		hvs_trans_unlock();
1743 	}
1744 
1745 	vmbus_chan_close(vmbus_get_channel(dev));
1746 
1747 	return (0);
1748 }
1749 
1750 static device_method_t hvsock_methods[] = {
1751 	/* Device interface */
1752 	DEVMETHOD(device_probe, hvsock_probe),
1753 	DEVMETHOD(device_attach, hvsock_attach),
1754 	DEVMETHOD(device_detach, hvsock_detach),
1755 	DEVMETHOD_END
1756 };
1757 
1758 static driver_t hvsock_driver = {
1759 	"hv_sock",
1760 	hvsock_methods,
1761 	sizeof(struct hvsock_sc)
1762 };
1763 
1764 static devclass_t hvsock_devclass;
1765 
1766 DRIVER_MODULE(hvsock, vmbus, hvsock_driver, hvsock_devclass, NULL, NULL);
1767 MODULE_VERSION(hvsock, 1);
1768 MODULE_DEPEND(hvsock, vmbus, 1, 1, 1);
1769