1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 /*
22  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  */
25 
26 /*
27  * Contains routines that deal with TLI/XTI endpoints and rpc services.
28  */
29 
30 #include <sys/types.h>
31 #include <string.h>
32 #include <fcntl.h>
33 #include <stdlib.h>
34 #include <libintl.h>
35 #include <unistd.h>
36 #include <sys/sysmacros.h>
37 #include <netconfig.h>
38 #include <errno.h>
39 #include <sys/sockio.h>
40 #include "inetd_impl.h"
41 
42 uu_list_pool_t *conn_ind_pool = NULL;
43 
44 /*
45  * RPC functions.
46  */
47 
48 /*
49  * Returns B_TRUE if the non-address components of the 2 rpc_info_t structures
50  * are equivalent, else B_FALSE.
51  */
52 boolean_t
rpc_info_equal(const rpc_info_t * ri,const rpc_info_t * ri2)53 rpc_info_equal(const rpc_info_t *ri, const rpc_info_t *ri2)
54 {
55 	return ((ri->prognum == ri2->prognum) &&
56 	    (ri->lowver == ri2->lowver) &&
57 	    (ri->highver == ri2->highver) &&
58 	    (strcmp(ri->netid, ri2->netid) == 0));
59 }
60 
61 /*
62  * Determine if we have a configured interface for the specified address
63  * family. This code is a mirror of libnsl's __can_use_af(). We mirror
64  * it because we need an exact duplicate of its behavior, yet the
65  * function isn't exported by libnsl, and this fix is considered short-
66  * term, so it's not worth exporting it.
67  *
68  * We need to duplicate __can_use_af() so we can accurately determine
69  * when getnetconfigent() returns failure for a v6 netid due to no IPv6
70  * interfaces being configured: getnetconfigent() returns failure
71  * if a netid is either 'tcp6' or 'udp6' and __can_use_af() returns 0,
72  * but it doesn't return a return code to uniquely determine this
73  * failure. If we don't accurately determine these failures, we could
74  * output error messages in a case when they weren't justified.
75  */
76 static int
can_use_af(sa_family_t af)77 can_use_af(sa_family_t af)
78 {
79 	struct lifnum	lifn;
80 	int		fd;
81 
82 	if ((fd =  open("/dev/udp", O_RDONLY)) < 0) {
83 		return (0);
84 	}
85 	lifn.lifn_family = af;
86 	/* LINTED ECONST_EXPR */
87 	lifn.lifn_flags = IFF_UP & !(IFF_NOXMIT | IFF_DEPRECATED);
88 	if (ioctl(fd, SIOCGLIFNUM, &lifn, sizeof (lifn)) < 0) {
89 		lifn.lifn_count = 0;
90 	}
91 
92 	(void) close(fd);
93 	return (lifn.lifn_count);
94 }
95 
96 static boolean_t
is_v6_netid(const char * netid)97 is_v6_netid(const char *netid)
98 {
99 	return ((strcmp(netid, SOCKET_PROTO_TCP6) == 0) ||
100 	    (strcmp(netid, SOCKET_PROTO_UDP6) == 0));
101 }
102 
103 /*
104  * Registers with rpcbind the program number with all versions, from low to
105  * high, with the netid, all specified in 'rpc'. If registration fails,
106  * returns -1, else 0.
107  */
108 int
register_rpc_service(const char * fmri,const rpc_info_t * rpc)109 register_rpc_service(const char *fmri, const rpc_info_t *rpc)
110 {
111 	struct netconfig	*nconf;
112 	int			ver;
113 
114 	if ((nconf = getnetconfigent(rpc->netid)) == NULL) {
115 		/*
116 		 * Check whether getnetconfigent() failed as a result of
117 		 * having no IPv6 interfaces configured for a v6 netid, or
118 		 * as a result of a 'real' error, and output an appropriate
119 		 * message with an appropriate severity.
120 		 */
121 		if (is_v6_netid(rpc->netid) && !can_use_af(AF_INET6)) {
122 			warn_msg(gettext(
123 			    "Couldn't register netid %s for RPC instance %s "
124 			    "because no IPv6 interfaces are plumbed"),
125 			    rpc->netid, fmri);
126 		} else {
127 			error_msg(gettext(
128 			    "Failed to lookup netid '%s' for instance %s: %s"),
129 			    rpc->netid, fmri, nc_sperror());
130 		}
131 		return (-1);
132 	}
133 
134 	for (ver = rpc->lowver; ver <= rpc->highver; ver++) {
135 		if (!rpcb_set(rpc->prognum, ver, nconf, &(rpc->netbuf))) {
136 			error_msg(gettext("Failed to register version %d "
137 			    "of RPC service instance %s, netid %s"), ver,
138 			    fmri, rpc->netid);
139 
140 			for (ver--; ver >= rpc->lowver; ver--)
141 				(void) rpcb_unset(rpc->prognum, ver, nconf);
142 
143 			freenetconfigent(nconf);
144 			return (-1);
145 		}
146 	}
147 
148 	freenetconfigent(nconf);
149 	return (0);
150 }
151 
152 /* Unregister all the registrations done by register_rpc_service */
153 void
unregister_rpc_service(const char * fmri,const rpc_info_t * rpc)154 unregister_rpc_service(const char *fmri, const rpc_info_t *rpc)
155 {
156 	int			ver;
157 	struct netconfig	*nconf;
158 
159 	if ((nconf = getnetconfigent(rpc->netid)) == NULL) {
160 		/*
161 		 * Don't output an error message if getnetconfigent() fails for
162 		 * a v6 netid when an IPv6 interface isn't configured.
163 		 */
164 		if (!(is_v6_netid(rpc->netid) && !can_use_af(AF_INET6))) {
165 			error_msg(gettext(
166 			    "Failed to lookup netid '%s' for instance %s: %s"),
167 			    rpc->netid, fmri, nc_sperror());
168 		}
169 		return;
170 	}
171 
172 	for (ver = rpc->lowver; ver <= rpc->highver; ver++)
173 		(void) rpcb_unset(rpc->prognum, ver, nconf);
174 
175 	freenetconfigent(nconf);
176 }
177 
178 /*
179  * TLI/XTI functions.
180  */
181 
182 int
tlx_init(void)183 tlx_init(void)
184 {
185 	if ((conn_ind_pool = uu_list_pool_create("conn_ind_pool",
186 	    sizeof (tlx_conn_ind_t), offsetof(tlx_conn_ind_t, link),
187 	    NULL, UU_LIST_POOL_DEBUG)) == NULL) {
188 		error_msg("%s: %s", gettext("Failed to create uu pool"),
189 		    uu_strerror(uu_error()));
190 		return (-1);
191 	}
192 
193 	return (0);
194 }
195 
196 void
tlx_fini(void)197 tlx_fini(void)
198 {
199 	if (conn_ind_pool != NULL) {
200 		uu_list_pool_destroy(conn_ind_pool);
201 		conn_ind_pool = NULL;
202 	}
203 }
204 
205 /*
206  * Checks if the contents of the 2 tlx_info_t structures are equivalent.
207  * If 'isrpc' is false, the address components of the two structures are
208  * compared for equality as part of this. If the two structures are
209  * equivalent B_TRUE is returned, else B_FALSE.
210  */
211 boolean_t
tlx_info_equal(const tlx_info_t * ti,const tlx_info_t * ti2,boolean_t isrpc)212 tlx_info_equal(const tlx_info_t *ti, const tlx_info_t *ti2, boolean_t isrpc)
213 {
214 	return ((isrpc || (memcmp(ti->local_addr.buf, ti2->local_addr.buf,
215 	    sizeof (struct sockaddr_storage)) == 0)) &&
216 	    (strcmp(ti->dev_name, ti2->dev_name) == 0));
217 }
218 
219 /*
220  * Attempts to bind an address to the network fd 'fd'. If 'reqaddr' is non-NULL,
221  * it attempts to bind to that requested address, else it binds to a kernel
222  * selected address. In the former case, the function returning success
223  * doesn't guarantee that the requested address was bound (the caller needs to
224  * check). If 'retaddr' is non-NULL, the bound address is returned in it. The
225  * 'qlen' parameter is used to set the connection backlog. If the bind
226  * succeeds 0 is returned, else -1.
227  */
228 static int
tlx_bind(int fd,const struct netbuf * reqaddr,struct netbuf * retaddr,int qlen)229 tlx_bind(int fd, const struct netbuf *reqaddr, struct netbuf *retaddr, int qlen)
230 {
231 	struct t_bind breq;
232 	struct t_bind bret;
233 
234 	if (retaddr != NULL) {	/* caller requests bound address be returned */
235 		bret.addr.buf = retaddr->buf;
236 		bret.addr.maxlen = retaddr->maxlen;
237 	}
238 
239 	if (reqaddr != NULL) {  /* caller requests specific address */
240 		breq.addr.buf = reqaddr->buf;
241 		breq.addr.len = reqaddr->len;
242 	} else {
243 		breq.addr.len = 0;
244 	}
245 	breq.qlen = qlen;
246 
247 	if (t_bind(fd, &breq, retaddr != NULL ? &bret : NULL) < 0)
248 		return (-1);
249 
250 	if (retaddr != NULL)
251 		retaddr->len = bret.addr.len;
252 
253 	return (0);
254 }
255 
256 static int
tlx_setsockopt(int fd,int level,int optname,const void * optval,socklen_t optlen)257 tlx_setsockopt(int fd, int level, int optname, const void *optval,
258     socklen_t optlen)
259 {
260 	struct t_optmgmt request, reply;
261 	struct {
262 		struct opthdr sockopt;
263 		char data[256];
264 	} optbuf;
265 
266 	if (optlen > sizeof (optbuf.data)) {
267 		error_msg(gettext("t_optmgmt request too long"));
268 		return (-1);
269 	}
270 
271 	optbuf.sockopt.level = level;
272 	optbuf.sockopt.name = optname;
273 	optbuf.sockopt.len = optlen;
274 	(void) memcpy(optbuf.data, optval, optlen);
275 
276 	request.opt.len = sizeof (struct opthdr) + optlen;
277 	request.opt.buf = (char *)&optbuf;
278 	request.flags = T_NEGOTIATE;
279 
280 	reply.opt.maxlen = sizeof (struct opthdr) + optlen;
281 	reply.opt.buf = (char *)&optbuf;
282 	reply.flags = 0;
283 
284 	if ((t_optmgmt(fd, &request, &reply) == -1) ||
285 	    (reply.flags != T_SUCCESS)) {
286 		error_msg("t_optmgmt: %s", t_strerror(t_errno));
287 		return (-1);
288 	}
289 	return (0);
290 }
291 
292 /*
293  * Compare contents of netbuf for equality. Return B_TRUE on a match and
294  * B_FALSE for mismatch.
295  */
296 static boolean_t
netbufs_equal(struct netbuf * n1,struct netbuf * n2)297 netbufs_equal(struct netbuf *n1, struct netbuf *n2)
298 {
299 	return ((n1->len == n2->len) &&
300 	    (memcmp(n1->buf, n2->buf, (size_t)n1->len) == 0));
301 }
302 
303 /*
304  * Create a tli/xti endpoint, either bound to the address specified in
305  * 'instance' for non-RPC services, else a kernel chosen address.
306  * Returns -1 on failure, else 0.
307  */
308 int
create_bound_endpoint(const instance_t * inst,tlx_info_t * tlx_info)309 create_bound_endpoint(const instance_t *inst, tlx_info_t *tlx_info)
310 {
311 	int			fd;
312 	int			qlen;
313 	const char		*fmri = inst->fmri;
314 	struct netbuf		*reqaddr;
315 	struct netbuf		*retaddr;
316 	struct netbuf		netbuf;
317 	struct sockaddr_storage	ss;
318 	rpc_info_t		*rpc = tlx_info->pr_info.ri;
319 
320 	if ((fd = t_open(tlx_info->dev_name, O_RDWR, NULL)) == -1) {
321 		error_msg(gettext("Failed to open transport %s for "
322 		    "instance %s, proto %s: %s"), tlx_info->dev_name,
323 		    fmri, tlx_info->pr_info.proto, t_strerror(t_errno));
324 		return (-1);
325 	}
326 
327 	if (tlx_info->pr_info.v6only) {
328 		int	on = 1;
329 
330 		/* restrict to IPv6 communications only */
331 		if (tlx_setsockopt(fd, IPPROTO_IPV6, IPV6_V6ONLY, &on,
332 		    sizeof (on)) == -1) {
333 			(void) t_close(fd);
334 			return (-1);
335 		}
336 	}
337 
338 	/*
339 	 * Negotiate for the returning of the remote uid for loopback
340 	 * transports for RPC services. This needs to be done before the
341 	 * endpoint is bound using t_bind(), so that any requests to it
342 	 * contain the uid.
343 	 */
344 	if ((rpc != NULL) && (rpc->is_loopback))
345 		svc_fd_negotiate_ucred(fd);
346 
347 	/*
348 	 * Bind the service's address to the endpoint and setup connection
349 	 * backlog. In the case of RPC services, we specify a NULL requested
350 	 * address and accept what we're given, storing the returned address
351 	 * for later RPC binding. In the case of non-RPC services we specify
352 	 * the service's associated address.
353 	 */
354 	if (rpc != NULL) {
355 		reqaddr = NULL;
356 		retaddr =  &(rpc->netbuf);
357 	} else {
358 		reqaddr = &(tlx_info->local_addr);
359 		netbuf.buf = (char *)&ss;
360 		netbuf.maxlen = sizeof (ss);
361 		retaddr = &netbuf;
362 	}
363 
364 	/* ignored for conn/less services */
365 	qlen = inst->config->basic->conn_backlog;
366 
367 	if ((tlx_bind(fd, reqaddr, retaddr, qlen) == -1) ||
368 	    ((reqaddr != NULL) && !netbufs_equal(reqaddr, retaddr))) {
369 		error_msg(gettext("Failed to bind to the requested address "
370 		    "for instance %s, proto %s"), fmri,
371 		    tlx_info->pr_info.proto);
372 		(void) t_close(fd);
373 		return (-1);
374 	}
375 
376 	return (fd);
377 }
378 
379 /*
380  * Takes a connection request off 'fd' in the form of a t_call structure
381  * and returns a pointer to it.
382  * Returns NULL on failure, else pointer to t_call structure on success.
383  */
384 static struct t_call *
get_new_conind(int fd)385 get_new_conind(int fd)
386 {
387 	struct t_call *call;
388 
389 	/* LINTED E_BAD_PTR_CAST_ALIGN */
390 	if ((call = (struct t_call *)t_alloc(fd, T_CALL, T_ALL)) == NULL) {
391 		error_msg("t_alloc: %s", t_strerror(t_errno));
392 		return (NULL);
393 	}
394 	if (t_listen(fd, call) < 0) {
395 		error_msg("t_listen: %s", t_strerror(t_errno));
396 		(void) t_free((char *)call, T_CALL);
397 		return (NULL);
398 	}
399 
400 	return (call);
401 }
402 
403 /* Add 'call' to the connection indication queue 'queue'. */
404 int
queue_conind(uu_list_t * queue,struct t_call * call)405 queue_conind(uu_list_t *queue, struct t_call *call)
406 {
407 	tlx_conn_ind_t *ci;
408 
409 	if ((ci = malloc(sizeof (tlx_conn_ind_t))) == NULL) {
410 		error_msg(strerror(errno));
411 		return (-1);
412 	}
413 
414 	ci->call = call;
415 	uu_list_node_init(ci, &ci->link, conn_ind_pool);
416 	(void) uu_list_insert_after(queue, NULL, ci);
417 
418 	return (0);
419 }
420 
421 /*
422  * Remove and return a pointer to the first call on queue 'queue'. However,
423  * if the queue is empty returns NULL.
424  */
425 struct t_call *
dequeue_conind(uu_list_t * queue)426 dequeue_conind(uu_list_t *queue)
427 {
428 	struct t_call   *ret;
429 	tlx_conn_ind_t	*ci = uu_list_first(queue);
430 
431 	if (ci == NULL)
432 		return (NULL);
433 
434 	ret = ci->call;
435 	uu_list_remove(queue, ci);
436 	free(ci);
437 
438 	return (ret);
439 }
440 
441 /*
442  * Handle a TLOOK notification received during a t_accept() call.
443  * Returns -1 on failure, else 0.
444  */
445 static int
process_tlook(const char * fmri,tlx_info_t * tlx_info)446 process_tlook(const char *fmri, tlx_info_t *tlx_info)
447 {
448 	int	event;
449 	int	fd = tlx_info->pr_info.listen_fd;
450 
451 	switch (event = t_look(fd)) {
452 	case T_LISTEN: {
453 		struct t_call *call;
454 
455 		debug_msg("process_tlook: T_LISTEN event");
456 		if ((call = get_new_conind(fd)) == NULL)
457 			return (-1);
458 		if (queue_conind(tlx_info->conn_ind_queue, call) == -1) {
459 			error_msg(gettext("Failed to queue connection "
460 			    "indication for instance %s"), fmri);
461 			(void) t_free((char *)call, T_CALL);
462 			return (-1);
463 		}
464 		break;
465 	}
466 	case T_DISCONNECT: {
467 		/*
468 		 * Note: In Solaris 2.X (SunOS 5.X) bundled
469 		 * connection-oriented transport drivers
470 		 * [ e.g /dev/tcp and /dev/ticots and
471 		 * /dev/ticotsord (tl)] we do not send disconnect
472 		 * indications to listening endpoints.
473 		 * So this will not be seen with endpoints on Solaris
474 		 * bundled transport devices. However, Streams TPI
475 		 * allows for this (broken?) behavior and so we account
476 		 * for it here because of the possibility of unbundled
477 		 * transport drivers causing this.
478 		 */
479 		tlx_conn_ind_t	*cip;
480 		struct t_discon	*discon;
481 
482 		debug_msg("process_tlook: T_DISCONNECT event");
483 
484 		/* LINTED */
485 		if ((discon = (struct t_discon *)
486 		    t_alloc(fd, T_DIS, T_ALL)) == NULL) {
487 			error_msg("t_alloc: %s", t_strerror(t_errno));
488 			return (-1);
489 		}
490 		if (t_rcvdis(fd, discon) < 0) {
491 			error_msg("t_rcvdis: %s", t_strerror(t_errno));
492 			(void) t_free((char *)discon, T_DIS);
493 			return (-1);
494 		}
495 
496 		/*
497 		 * Find any queued connection pending that matches this
498 		 * disconnect notice and remove from the pending queue.
499 		 */
500 		cip = uu_list_first(tlx_info->conn_ind_queue);
501 		while ((cip != NULL) &&
502 		    (cip->call->sequence != discon->sequence)) {
503 			cip = uu_list_next(tlx_info->conn_ind_queue, cip);
504 		}
505 		if (cip != NULL) {	/* match found */
506 			uu_list_remove(tlx_info->conn_ind_queue, cip);
507 			(void) t_free((char *)cip->call, T_CALL);
508 			free(cip);
509 		}
510 
511 		(void) t_free((char *)discon, T_DIS);
512 		break;
513 	}
514 	case -1:
515 		error_msg("t_look: %s", t_strerror(t_errno));
516 		return (-1);
517 	default:
518 		error_msg(gettext("do_tlook: unexpected t_look event: %d"),
519 		    event);
520 		return (-1);
521 	}
522 
523 	return (0);
524 }
525 
526 /*
527  * This call attempts to t_accept() an incoming/pending TLI connection.
528  * If it is thwarted by a TLOOK, it is deferred and whatever is on the
529  * file descriptor, removed after a t_look. (Incoming connect indications
530  * get queued for later processing and disconnect indications remove a
531  * a queued connection request if a match found).
532  * Returns -1 on failure, else 0.
533  */
534 int
tlx_accept(const char * fmri,tlx_info_t * tlx_info,struct sockaddr_storage * remote_addr)535 tlx_accept(const char *fmri, tlx_info_t *tlx_info,
536     struct sockaddr_storage *remote_addr)
537 {
538 	tlx_conn_ind_t	*conind;
539 	struct t_call	*call;
540 	int		fd;
541 	int		listen_fd = tlx_info->pr_info.listen_fd;
542 
543 	if ((fd = t_open(tlx_info->dev_name, O_RDWR, NULL)) == -1) {
544 		error_msg("t_open: %s", t_strerror(t_errno));
545 		return (-1);
546 	}
547 
548 	if (tlx_info->pr_info.v6only) {
549 		int	on = 1;
550 
551 		/* restrict to IPv6 communications only */
552 		if (tlx_setsockopt(fd, IPPROTO_IPV6, IPV6_V6ONLY, &on,
553 		    sizeof (on)) == -1) {
554 			(void) t_close(fd);
555 			return (-1);
556 		}
557 	}
558 
559 	if (t_bind(fd, NULL, NULL) == -1) {
560 		error_msg("t_bind: %s", t_strerror(t_errno));
561 		(void) t_close(fd);
562 		return (-1);
563 	}
564 
565 	/*
566 	 * Get the next connection indication - first try the pending
567 	 * queue, then, if none there, get a new one from the file descriptor.
568 	 */
569 	if ((conind = uu_list_first(tlx_info->conn_ind_queue)) != NULL) {
570 		debug_msg("taking con off queue");
571 		call = conind->call;
572 	} else if ((call = get_new_conind(listen_fd)) == NULL) {
573 		(void) t_close(fd);
574 		return (-1);
575 	}
576 
577 	/*
578 	 * Accept the connection indication on the newly created endpoint.
579 	 * If we fail, and it's the result of a tlook, queue the indication
580 	 * if it isn't already, and go and process the t_look.
581 	 */
582 	if (t_accept(listen_fd, fd, call) == -1) {
583 		if (t_errno == TLOOK) {
584 			if (uu_list_first(tlx_info->conn_ind_queue) == NULL) {
585 				/*
586 				 * We are first one to have to defer accepting
587 				 * and start the pending connections list.
588 				 */
589 				if (queue_conind(tlx_info->conn_ind_queue,
590 				    call) == -1) {
591 					error_msg(gettext(
592 					    "Failed to queue connection "
593 					    "indication for instance %s"),
594 					    fmri);
595 					(void) t_free((char *)call, T_CALL);
596 					return (-1);
597 				}
598 			}
599 			(void) process_tlook(fmri, tlx_info);
600 		} else {		  /* non-TLOOK accept failure */
601 			error_msg("%s: %s", "t_accept failed",
602 			    t_strerror(t_errno));
603 			/*
604 			 * If we were accepting a queued connection, dequeue
605 			 * it.
606 			 */
607 			if (uu_list_first(tlx_info->conn_ind_queue) != NULL)
608 				(void) dequeue_conind(tlx_info->conn_ind_queue);
609 			(void) t_free((char *)call, T_CALL);
610 		}
611 
612 		(void) t_close(fd);
613 		return (-1);
614 	}
615 
616 	/* Copy remote address into address parameter */
617 	(void) memcpy(remote_addr, call->addr.buf,
618 	    MIN(call->addr.len, sizeof (*remote_addr)));
619 
620 	/* If we were accepting a queued connection, dequeue it. */
621 	if (uu_list_first(tlx_info->conn_ind_queue) != NULL)
622 		(void) dequeue_conind(tlx_info->conn_ind_queue);
623 	(void) t_free((char *)call, T_CALL);
624 
625 	return (fd);
626 }
627 
628 /* protocol independent network fd close routine */
629 void
close_net_fd(instance_t * inst,int fd)630 close_net_fd(instance_t *inst, int fd)
631 {
632 	if (inst->config->basic->istlx) {
633 		(void) t_close(fd);
634 	} else {
635 		(void) close(fd);
636 	}
637 }
638 
639 /*
640  * Consume some data from the given endpoint of the given wait-based instance.
641  */
642 void
consume_wait_data(instance_t * inst,int fd)643 consume_wait_data(instance_t *inst, int fd)
644 {
645 	int	flag;
646 	char	buf[50];	/* same arbitrary size as old inetd */
647 
648 	if (inst->config->basic->istlx) {
649 		(void) t_rcv(fd, buf, sizeof (buf), &flag);
650 	} else {
651 		(void) recv(fd, buf, sizeof (buf), 0);
652 	}
653 }
654