xref: /illumos-gate/usr/src/lib/libnsl/nsl/t_snddis.c (revision bdb9230ac765cb7af3fc1f4119caf2c5720dceb3)
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, Version 1.0 only
6  * (the "License").  You may not use this file except in compliance
7  * with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or http://www.opensolaris.org/os/licensing.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 
23 /*	Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T	*/
24 /*	  All Rights Reserved  	*/
25 
26 /*
27  * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
28  * Use is subject to license terms.
29  */
30 
31 #pragma ident	"%Z%%M%	%I%	%E% SMI"	/* SVr4.0 1.4.3.1 */
32 
33 #include "mt.h"
34 #include <errno.h>
35 #include <unistd.h>
36 #include <stropts.h>
37 #include <sys/stream.h>
38 #define	_SUN_TPI_VERSION 2
39 #include <sys/tihdr.h>
40 #include <sys/timod.h>
41 #include <xti.h>
42 #include <signal.h>
43 #include <syslog.h>
44 #include "tx.h"
45 
46 int
47 _tx_snddis(int fd, const struct t_call *call, int api_semantics)
48 {
49 	struct T_discon_req dreq;
50 	struct strbuf ctlbuf;
51 	struct strbuf databuf;
52 	struct _ti_user *tiptr;
53 	int sv_errno;
54 	int retval;
55 
56 	if ((tiptr = _t_checkfd(fd, 0, api_semantics)) == NULL)
57 		return (-1);
58 	sig_mutex_lock(&tiptr->ti_lock);
59 
60 	if (tiptr->ti_servtype == T_CLTS) {
61 		t_errno = TNOTSUPPORT;
62 		sig_mutex_unlock(&tiptr->ti_lock);
63 		return (-1);
64 	}
65 
66 	if (_T_IS_XTI(api_semantics)) {
67 		/*
68 		 * User level state verification only done for XTI
69 		 * because doing for TLI may break existing applications
70 		 * Note: This is documented in TLI man page but never
71 		 * done.
72 		 */
73 		if (!(tiptr->ti_state == T_DATAXFER ||
74 		    tiptr->ti_state == T_OUTCON ||
75 		    tiptr->ti_state == T_OUTREL ||
76 		    tiptr->ti_state == T_INREL ||
77 		    (tiptr->ti_state == T_INCON && tiptr->ti_ocnt > 0))) {
78 			t_errno = TOUTSTATE;
79 			sig_mutex_unlock(&tiptr->ti_lock);
80 			return (-1);
81 		}
82 
83 		/*
84 		 * Following check only done for XTI as it may be a risk
85 		 * to existing buggy TLI applications.
86 		 */
87 	}
88 
89 	if (call != NULL && call->udata.len) {
90 		if ((tiptr->ti_ddatasize == T_INVALID /* -2 */) ||
91 		    ((tiptr->ti_ddatasize != T_INFINITE /* -1*/) &&
92 			(call->udata.len >
93 			    (uint32_t)tiptr->ti_ddatasize))) {
94 			/*
95 			 * user data not valid with disconnect or it
96 			 * exceeds the limits specified by the
97 			 * transport provider
98 			 */
99 			t_errno = TBADDATA;
100 			sig_mutex_unlock(&tiptr->ti_lock);
101 			return (-1);
102 		}
103 	}
104 
105 	/*
106 	 * If disconnect is done on a listener, the 'call' parameter
107 	 * must be non-null
108 	 */
109 	if ((tiptr->ti_state == T_INCON) &&
110 	    (call == NULL)) {
111 		t_errno = TBADSEQ;
112 		sig_mutex_unlock(&tiptr->ti_lock);
113 		return (-1);
114 	}
115 
116 	/*
117 	 * look at look buffer to see if there is a discon there
118 	 */
119 
120 	if (_t_look_locked(fd, tiptr, 0, api_semantics) == T_DISCONNECT) {
121 		t_errno = TLOOK;
122 		sig_mutex_unlock(&tiptr->ti_lock);
123 		return (-1);
124 	}
125 
126 	if ((tiptr->ti_lookcnt > 0) && (call == 0))
127 		_t_flush_lookevents(tiptr); /* flush but not on listener */
128 
129 	do {
130 		retval = ioctl(fd, I_FLUSH, FLUSHW);
131 	} while (retval < 0 && errno == EINTR);
132 	if (retval < 0) {
133 		sv_errno = errno;
134 		t_errno = TSYSERR;
135 		sig_mutex_unlock(&tiptr->ti_lock);
136 		errno = sv_errno;
137 		return (-1);
138 	}
139 
140 	ctlbuf.len = (int)sizeof (struct T_discon_req);
141 	ctlbuf.maxlen = (int)sizeof (struct T_discon_req);
142 	ctlbuf.buf = (char *)&dreq;
143 
144 	dreq.PRIM_type = T_DISCON_REQ;
145 	dreq.SEQ_number = (call? call->sequence: -1);
146 
147 	databuf.maxlen = (call? call->udata.len: 0);
148 	databuf.len = (call? call->udata.len: 0);
149 	databuf.buf = (call? call->udata.buf: NULL);
150 
151 	/*
152 	 * Calls to send data (write or putmsg) can potentially
153 	 * block, for MT case, we drop the lock and enable signals here
154 	 * and acquire it back
155 	 */
156 	sig_mutex_unlock(&tiptr->ti_lock);
157 	if (putmsg(fd, &ctlbuf, (databuf.len? &databuf: NULL), 0) < 0) {
158 		t_errno = TSYSERR;
159 		return (-1);
160 	}
161 	sig_mutex_lock(&tiptr->ti_lock);
162 
163 	if (_t_is_ok(fd, tiptr, T_DISCON_REQ) < 0) {
164 		sv_errno = errno;
165 		sig_mutex_unlock(&tiptr->ti_lock);
166 		errno = sv_errno;
167 		return (-1);
168 	}
169 
170 	tiptr->ti_flags &= ~(MORE|EXPEDITED);
171 
172 	if (tiptr->ti_ocnt <= 1) {
173 		if (tiptr->ti_state == T_INCON) {
174 			tiptr->ti_ocnt--;
175 			tiptr->ti_flags &= ~TX_TQFULL_NOTIFIED;
176 		}
177 		_T_TX_NEXTSTATE(T_SNDDIS1, tiptr,
178 				"t_snddis: invalid state event T_SNDDIS1");
179 	} else {
180 		if (tiptr->ti_state == T_INCON) {
181 			tiptr->ti_ocnt--;
182 			tiptr->ti_flags &= ~TX_TQFULL_NOTIFIED;
183 		}
184 		_T_TX_NEXTSTATE(T_SNDDIS2, tiptr,
185 				"t_snddis: invalid state event T_SNDDIS2");
186 	}
187 
188 	sig_mutex_unlock(&tiptr->ti_lock);
189 	return (0);
190 }
191