xref: /illumos-gate/usr/src/lib/libnsl/nsl/t_snddis.c (revision 8119dad84d6416f13557b0ba8e2aaf9064cbcfd3)
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 #include "mt.h"
32 #include <errno.h>
33 #include <unistd.h>
34 #include <stropts.h>
35 #include <sys/stream.h>
36 #define	_SUN_TPI_VERSION 2
37 #include <sys/tihdr.h>
38 #include <sys/timod.h>
39 #include <xti.h>
40 #include <signal.h>
41 #include <syslog.h>
42 #include "tx.h"
43 
44 int
45 _tx_snddis(int fd, const struct t_call *call, int api_semantics)
46 {
47 	struct T_discon_req dreq;
48 	struct strbuf ctlbuf;
49 	struct strbuf databuf;
50 	struct _ti_user *tiptr;
51 	int sv_errno;
52 	int retval;
53 
54 	if ((tiptr = _t_checkfd(fd, 0, api_semantics)) == NULL)
55 		return (-1);
56 	sig_mutex_lock(&tiptr->ti_lock);
57 
58 	if (tiptr->ti_servtype == T_CLTS) {
59 		t_errno = TNOTSUPPORT;
60 		sig_mutex_unlock(&tiptr->ti_lock);
61 		return (-1);
62 	}
63 
64 	if (_T_IS_XTI(api_semantics)) {
65 		/*
66 		 * User level state verification only done for XTI
67 		 * because doing for TLI may break existing applications
68 		 * Note: This is documented in TLI man page but never
69 		 * done.
70 		 */
71 		if (!(tiptr->ti_state == T_DATAXFER ||
72 		    tiptr->ti_state == T_OUTCON ||
73 		    tiptr->ti_state == T_OUTREL ||
74 		    tiptr->ti_state == T_INREL ||
75 		    (tiptr->ti_state == T_INCON && tiptr->ti_ocnt > 0))) {
76 			t_errno = TOUTSTATE;
77 			sig_mutex_unlock(&tiptr->ti_lock);
78 			return (-1);
79 		}
80 
81 		/*
82 		 * Following check only done for XTI as it may be a risk
83 		 * to existing buggy TLI applications.
84 		 */
85 	}
86 
87 	if (call != NULL && call->udata.len) {
88 		if ((tiptr->ti_ddatasize == T_INVALID /* -2 */) ||
89 		    ((tiptr->ti_ddatasize != T_INFINITE /* -1*/) &&
90 			(call->udata.len >
91 			    (uint32_t)tiptr->ti_ddatasize))) {
92 			/*
93 			 * user data not valid with disconnect or it
94 			 * exceeds the limits specified by the
95 			 * transport provider
96 			 */
97 			t_errno = TBADDATA;
98 			sig_mutex_unlock(&tiptr->ti_lock);
99 			return (-1);
100 		}
101 	}
102 
103 	/*
104 	 * If disconnect is done on a listener, the 'call' parameter
105 	 * must be non-null
106 	 */
107 	if ((tiptr->ti_state == T_INCON) &&
108 	    (call == NULL)) {
109 		t_errno = TBADSEQ;
110 		sig_mutex_unlock(&tiptr->ti_lock);
111 		return (-1);
112 	}
113 
114 	/*
115 	 * look at look buffer to see if there is a discon there
116 	 */
117 
118 	if (_t_look_locked(fd, tiptr, 0, api_semantics) == T_DISCONNECT) {
119 		t_errno = TLOOK;
120 		sig_mutex_unlock(&tiptr->ti_lock);
121 		return (-1);
122 	}
123 
124 	if ((tiptr->ti_lookcnt > 0) && (call == 0))
125 		_t_flush_lookevents(tiptr); /* flush but not on listener */
126 
127 	do {
128 		retval = ioctl(fd, I_FLUSH, FLUSHW);
129 	} while (retval < 0 && errno == EINTR);
130 	if (retval < 0) {
131 		sv_errno = errno;
132 		t_errno = TSYSERR;
133 		sig_mutex_unlock(&tiptr->ti_lock);
134 		errno = sv_errno;
135 		return (-1);
136 	}
137 
138 	ctlbuf.len = (int)sizeof (struct T_discon_req);
139 	ctlbuf.maxlen = (int)sizeof (struct T_discon_req);
140 	ctlbuf.buf = (char *)&dreq;
141 
142 	dreq.PRIM_type = T_DISCON_REQ;
143 	dreq.SEQ_number = (call? call->sequence: -1);
144 
145 	databuf.maxlen = (call? call->udata.len: 0);
146 	databuf.len = (call? call->udata.len: 0);
147 	databuf.buf = (call? call->udata.buf: NULL);
148 
149 	/*
150 	 * Calls to send data (write or putmsg) can potentially
151 	 * block, for MT case, we drop the lock and enable signals here
152 	 * and acquire it back
153 	 */
154 	sig_mutex_unlock(&tiptr->ti_lock);
155 	if (putmsg(fd, &ctlbuf, (databuf.len? &databuf: NULL), 0) < 0) {
156 		t_errno = TSYSERR;
157 		return (-1);
158 	}
159 	sig_mutex_lock(&tiptr->ti_lock);
160 
161 	if (_t_is_ok(fd, tiptr, T_DISCON_REQ) < 0) {
162 		sv_errno = errno;
163 		sig_mutex_unlock(&tiptr->ti_lock);
164 		errno = sv_errno;
165 		return (-1);
166 	}
167 
168 	tiptr->ti_flags &= ~(MORE|EXPEDITED);
169 
170 	if (tiptr->ti_ocnt <= 1) {
171 		if (tiptr->ti_state == T_INCON) {
172 			tiptr->ti_ocnt--;
173 			tiptr->ti_flags &= ~TX_TQFULL_NOTIFIED;
174 		}
175 		_T_TX_NEXTSTATE(T_SNDDIS1, tiptr,
176 				"t_snddis: invalid state event T_SNDDIS1");
177 	} else {
178 		if (tiptr->ti_state == T_INCON) {
179 			tiptr->ti_ocnt--;
180 			tiptr->ti_flags &= ~TX_TQFULL_NOTIFIED;
181 		}
182 		_T_TX_NEXTSTATE(T_SNDDIS2, tiptr,
183 				"t_snddis: invalid state event T_SNDDIS2");
184 	}
185 
186 	sig_mutex_unlock(&tiptr->ti_lock);
187 	return (0);
188 }
189