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