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 1.5.3.3 */
32
33 #include "mt.h"
34 #include <stdlib.h>
35 #include <string.h>
36 #include <strings.h>
37 #include <unistd.h>
38 #include <errno.h>
39 #include <stropts.h>
40 #include <sys/stream.h>
41 #define _SUN_TPI_VERSION 2
42 #include <sys/tihdr.h>
43 #include <sys/timod.h>
44 #include <sys/stat.h>
45 #include <xti.h>
46 #include <fcntl.h>
47 #include <signal.h>
48 #include <assert.h>
49 #include <syslog.h>
50 #include <limits.h>
51 #include "tx.h"
52
53 /*
54 * If _tx_open is called for transport that doesn't understand T_CAPABILITY_REQ
55 * TPI message, call to _t_create may fail the first time it is called with
56 * given transport (in the rare case when transport shuts down the stream with
57 * M_ERROR in reply to unknown T_CAPABILITY_REQ). In this case we may reopen the
58 * stream again since timod will emulate T_CAPABILITY_REQ behaviour.
59 *
60 * _t_create sends T_CAPABILITY_REQ through TI_CAPABILITY ioctl.
61 */
62
63 int
_tx_open(const char * path,int flags,struct t_info * info,int api_semantics)64 _tx_open(const char *path, int flags, struct t_info *info, int api_semantics)
65 {
66 int retval, fd, sv_errno;
67 int sv_terrno;
68 int sv_errno_global;
69 struct _ti_user *tiptr;
70 sigset_t mask;
71 int t_create_first_attempt = 1;
72 int ticap_ioctl_failed = 0;
73
74 if (!(flags & O_RDWR)) {
75 t_errno = TBADFLAG;
76 return (-1);
77 }
78
79 sv_errno_global = errno;
80 sv_terrno = t_errno;
81
82 retry:
83 if ((fd = open(path, flags)) < 0) {
84 t_errno = TSYSERR;
85 if (_T_IS_XTI(api_semantics) && errno == ENOENT)
86 /* XTI only */
87 t_errno = TBADNAME;
88 return (-1);
89 }
90 /*
91 * is module already pushed
92 */
93 do {
94 retval = ioctl(fd, I_FIND, "timod");
95 } while (retval < 0 && errno == EINTR);
96
97 if (retval < 0) {
98 sv_errno = errno;
99
100 t_errno = TSYSERR;
101 (void) close(fd);
102 errno = sv_errno;
103 return (-1);
104 }
105
106 if (retval == 0) {
107 /*
108 * "timod" not already on stream, then push it
109 */
110 do {
111 /*
112 * Assumes (correctly) that I_PUSH is
113 * atomic w.r.t signals (EINTR error)
114 */
115 retval = ioctl(fd, I_PUSH, "timod");
116 } while (retval < 0 && errno == EINTR);
117
118 if (retval < 0) {
119 int sv_errno = errno;
120
121 t_errno = TSYSERR;
122 (void) close(fd);
123 errno = sv_errno;
124 return (-1);
125 }
126 }
127
128 /*
129 * _t_create() requires that all signals be blocked.
130 * Note that sig_mutex_lock() only defers signals, it does not
131 * block them, so interruptible syscalls could still get EINTR.
132 */
133 (void) thr_sigsetmask(SIG_SETMASK, &fillset, &mask);
134 sig_mutex_lock(&_ti_userlock);
135 /*
136 * Call to _t_create may fail either because transport doesn't
137 * understand T_CAPABILITY_REQ or for some other reason. It is nearly
138 * impossible to distinguish between these cases so it is implicitly
139 * assumed that it is always save to close and reopen the same stream
140 * and that open/close doesn't have side effects. _t_create may fail
141 * only once if its' failure is caused by unimplemented
142 * T_CAPABILITY_REQ.
143 */
144 tiptr = _t_create(fd, info, api_semantics, &ticap_ioctl_failed);
145 if (tiptr == NULL) {
146 /*
147 * If _t_create failed due to fail of ti_capability_req we may
148 * try to reopen the stream in the hope that timod will emulate
149 * TI_CAPABILITY and it will succeed when called again.
150 */
151 if (t_create_first_attempt == 1 && ticap_ioctl_failed == 1) {
152 t_create_first_attempt = 0;
153 (void) close(fd);
154 errno = sv_errno_global;
155 t_errno = sv_terrno;
156 sig_mutex_unlock(&_ti_userlock);
157 (void) thr_sigsetmask(SIG_SETMASK, &mask, NULL);
158 goto retry;
159 } else {
160 int sv_errno = errno;
161 (void) close(fd);
162 sig_mutex_unlock(&_ti_userlock);
163 (void) thr_sigsetmask(SIG_SETMASK, &mask, NULL);
164 errno = sv_errno;
165 return (-1);
166 }
167 }
168
169 /*
170 * _t_create synchronizes state witk kernel timod and
171 * already sets it to T_UNBND - what it needs to be
172 * be on T_OPEN event. No _T_TX_NEXTSTATE needed here.
173 */
174 sig_mutex_unlock(&_ti_userlock);
175 (void) thr_sigsetmask(SIG_SETMASK, &mask, NULL);
176
177 do {
178 retval = ioctl(fd, I_FLUSH, FLUSHRW);
179 } while (retval < 0 && errno == EINTR);
180
181 /*
182 * We ignore other error cases (retval < 0) - assumption is
183 * that I_FLUSH failures is temporary (e.g. ENOSR) or
184 * otherwise benign failure on a this newly opened file
185 * descriptor and not a critical failure.
186 */
187
188 return (fd);
189 }
190