xref: /illumos-gate/usr/src/lib/libnsl/nsl/t_rcvdis.c (revision 24da5b34f49324ed742a340010ed5bd3d4e06625)
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 2005 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 1.10 */
32 
33 #include "mt.h"
34 #include <stdlib.h>
35 #include <string.h>
36 #include <errno.h>
37 #include <stropts.h>
38 #include <sys/stream.h>
39 #define	_SUN_TPI_VERSION 2
40 #include <sys/tihdr.h>
41 #include <sys/timod.h>
42 #include <xti.h>
43 #include <signal.h>
44 #include <syslog.h>
45 #include "tx.h"
46 
47 int
48 _tx_rcvdis(int fd, struct t_discon *discon, int api_semantics)
49 {
50 	struct strbuf ctlbuf;
51 	struct strbuf databuf;
52 	int retval;
53 	union T_primitives *pptr;
54 	struct _ti_user *tiptr;
55 	int sv_errno;
56 	int flg = 0;
57 	int didalloc, didralloc;
58 	int use_lookbufs = 0;
59 
60 	if ((tiptr = _t_checkfd(fd, 0, api_semantics)) == NULL)
61 		return (-1);
62 
63 	/*
64 	 * Acquire per thread lock.
65 	 * Note: Lock is held across most of this routine
66 	 * including the blocking getmsg() call. This is fine
67 	 * because it is first verfied that an event is pending
68 	 */
69 	sig_mutex_lock(&tiptr->ti_lock);
70 
71 	if (tiptr->ti_servtype == T_CLTS) {
72 		t_errno = TNOTSUPPORT;
73 		sig_mutex_unlock(&tiptr->ti_lock);
74 		return (-1);
75 	}
76 
77 	if (_T_IS_XTI(api_semantics)) {
78 		/*
79 		 * User level state verification only done for XTI
80 		 * because doing for TLI may break existing applications
81 		 */
82 		if (!(tiptr->ti_state == T_DATAXFER ||
83 		    tiptr->ti_state == T_OUTCON ||
84 		    tiptr->ti_state == T_OUTREL ||
85 		    tiptr->ti_state == T_INREL ||
86 		    (tiptr->ti_state == T_INCON && tiptr->ti_ocnt > 0))) {
87 			t_errno = TOUTSTATE;
88 			sig_mutex_unlock(&tiptr->ti_lock);
89 			return (-1);
90 		}
91 	}
92 	/*
93 	 * Handle likely scenario as special case:
94 	 * Is there a discon in look buffer as the first
95 	 * event in the lookbuffer, is so just get it.
96 	 */
97 	if ((tiptr->ti_lookcnt > 0) &&
98 	    /* LINTED pointer cast */
99 	    (*((t_scalar_t *)tiptr->ti_lookbufs.tl_lookcbuf) == T_DISCON_IND)) {
100 		/*
101 		 * The T_DISCON_IND is already in the look buffer
102 		 */
103 		ctlbuf.len = tiptr->ti_lookbufs.tl_lookclen;
104 		ctlbuf.buf = tiptr->ti_lookbufs.tl_lookcbuf;
105 		/* Note: ctlbuf.maxlen not used in this case */
106 
107 		databuf.len = tiptr->ti_lookbufs.tl_lookdlen;
108 		databuf.buf = tiptr->ti_lookbufs.tl_lookdbuf;
109 		/* Note databuf.maxlen not used in this case */
110 
111 		use_lookbufs = 1;
112 
113 	} else {
114 
115 		if ((retval = _t_look_locked(fd, tiptr, 0,
116 		    api_semantics)) < 0) {
117 			sv_errno = errno;
118 			sig_mutex_unlock(&tiptr->ti_lock);
119 			errno = sv_errno;
120 			return (-1);
121 		}
122 
123 		if (retval != T_DISCONNECT) {
124 			t_errno = TNODIS;
125 			sig_mutex_unlock(&tiptr->ti_lock);
126 			return (-1);
127 		}
128 
129 		/*
130 		 * get disconnect off read queue.
131 		 * use ctl and rcv buffers
132 		 *
133 		 * Acquire ctlbuf for use in sending/receiving control part
134 		 * of the message.
135 		 */
136 		if (_t_acquire_ctlbuf(tiptr, &ctlbuf, &didalloc) < 0) {
137 			sv_errno = errno;
138 			sig_mutex_unlock(&tiptr->ti_lock);
139 			errno = sv_errno;
140 			return (-1);
141 		}
142 
143 		/*
144 		 * Acquire databuf for use in sending/receiving data part
145 		 */
146 		if (_t_acquire_databuf(tiptr, &databuf, &didralloc) < 0) {
147 			sv_errno = errno;
148 			if (didalloc)
149 				free(ctlbuf.buf);
150 			else
151 				tiptr->ti_ctlbuf = ctlbuf.buf;
152 			sig_mutex_unlock(&tiptr->ti_lock);
153 			errno = sv_errno;
154 			return (-1);
155 		}
156 
157 		/*
158 		 * Since we already verified that a disconnect event
159 		 * is present, we assume that this getmsg() cannot
160 		 * block indefinitely
161 		 */
162 		do {
163 			retval = getmsg(fd, &ctlbuf, &databuf, &flg);
164 		} while (retval < 0 && errno == EINTR);
165 
166 		if (retval  < 0) {
167 			t_errno = TSYSERR;
168 			goto err_out;
169 		}
170 		if (databuf.len == -1) databuf.len = 0;
171 
172 		/*
173 		 * did I get entire message?
174 		 */
175 		if (retval > 0) {
176 			t_errno = TSYSERR;
177 			errno = EIO;
178 			goto err_out;
179 		}
180 	}
181 
182 
183 	/* LINTED pointer cast */
184 	pptr = (union T_primitives *)ctlbuf.buf;
185 
186 	if ((ctlbuf.len < (int)sizeof (struct T_discon_ind)) ||
187 	    (pptr->type != T_DISCON_IND)) {
188 		t_errno = TSYSERR;
189 		errno = EPROTO;
190 		goto err_out;
191 	}
192 
193 	/*
194 	 * clear more and expedited flags
195 	 */
196 	tiptr->ti_flags &= ~(MORE | EXPEDITED);
197 
198 	if (tiptr->ti_ocnt <= 0) {
199 		_T_TX_NEXTSTATE(T_RCVDIS1, tiptr,
200 				"t_rcvdis: invalid state event T_RCVDIS1");
201 	} else {
202 		if (tiptr->ti_ocnt == 1) {
203 			_T_TX_NEXTSTATE(T_RCVDIS2, tiptr,
204 				"t_rcvdis: invalid state event T_RCVDIS2");
205 		} else {
206 			_T_TX_NEXTSTATE(T_RCVDIS3, tiptr,
207 				"t_rcvdis: invalid state event T_RCVDIS3");
208 		}
209 		tiptr->ti_ocnt--;
210 		tiptr->ti_flags &= ~TX_TQFULL_NOTIFIED;
211 	}
212 
213 	if (discon != NULL) {
214 		if (_T_IS_TLI(api_semantics) || discon->udata.maxlen > 0) {
215 			if (databuf.len > (int)discon->udata.maxlen) {
216 				t_errno = TBUFOVFLW;
217 				goto err_out;
218 			}
219 			(void) memcpy(discon->udata.buf, databuf.buf,
220 			    (size_t)databuf.len);
221 			discon->udata.len = databuf.len;
222 		}
223 		discon->reason = pptr->discon_ind.DISCON_reason;
224 		discon->sequence = pptr->discon_ind.SEQ_number;
225 	}
226 	if (use_lookbufs)
227 		_t_free_looklist_head(tiptr);
228 	else {
229 		if (didalloc)
230 			free(ctlbuf.buf);
231 		else
232 			tiptr->ti_ctlbuf = ctlbuf.buf;
233 		if (didralloc)
234 			free(databuf.buf);
235 		else
236 			tiptr->ti_rcvbuf = databuf.buf;
237 	}
238 	sig_mutex_unlock(&tiptr->ti_lock);
239 	return (0);
240 
241 err_out:
242 	sv_errno = errno;
243 
244 	if (use_lookbufs)
245 		_t_free_looklist_head(tiptr);
246 	else {
247 		if (didalloc)
248 			free(ctlbuf.buf);
249 		else
250 			tiptr->ti_ctlbuf = ctlbuf.buf;
251 		if (didralloc)
252 			free(databuf.buf);
253 		else
254 			tiptr->ti_rcvbuf = databuf.buf;
255 	}
256 	sig_mutex_unlock(&tiptr->ti_lock);
257 	errno = sv_errno;
258 	return (-1);
259 }
260