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 2004 Sun Microsystems, Inc. All rights reserved.
24 * Use is subject to license terms.
25 */
26
27 #pragma ident "%Z%%M% %I% %E% SMI"
28
29 /*
30 * Utility functions for buffering output to stdout, stderr while
31 * process is grabbed. Prevents infamous deadlocks due to pfiles `pgrep xterm`
32 * and other varients.
33 */
34
35 #include "libproc.h"
36 #include <stdio.h>
37
38 static int cached_stdout_fd = -1;
39 static int cached_stderr_fd = -1;
40 static int initialized = 0;
41
42 static char stdout_name[] = "/tmp/.stdoutXXXXXX";
43 static char stderr_name[] = "/tmp/.stderrXXXXXX";
44
45 int
proc_initstdio(void)46 proc_initstdio(void)
47 {
48 int fd;
49
50 (void) fflush(stdout);
51 (void) fflush(stderr);
52
53 if ((cached_stdout_fd = dup(1)) < 0) {
54 return (-1);
55 }
56
57 if ((cached_stderr_fd = dup(2)) < 0) {
58 (void) close(cached_stdout_fd);
59 return (-1);
60 }
61
62 if ((fd = mkstemp(stdout_name)) < 0) {
63 (void) close(cached_stdout_fd);
64 (void) close(cached_stderr_fd);
65 return (-1);
66 }
67
68 (void) unlink(stdout_name);
69
70 if (dup2(fd, 1) < 0) {
71 (void) close(fd);
72 (void) close(cached_stdout_fd);
73 (void) close(cached_stderr_fd);
74 return (-1);
75 }
76
77 (void) close(fd);
78
79
80 if ((fd = mkstemp(stderr_name)) < 0) {
81 (void) dup2(cached_stdout_fd, 1);
82 (void) close(cached_stdout_fd);
83 (void) close(cached_stderr_fd);
84 return (-1);
85 }
86
87 (void) unlink(stderr_name);
88
89 if (dup2(fd, 2) < 0) {
90 (void) close(fd);
91 (void) dup2(cached_stdout_fd, 1);
92 (void) close(cached_stdout_fd);
93 (void) dup2(cached_stderr_fd, 2);
94 (void) close(cached_stderr_fd);
95 (void) close(fd);
96 return (-1);
97 }
98
99 (void) close(fd);
100
101 initialized = 1;
102
103 return (0);
104 }
105
106 static int
copy_fd(int out,FILE * in,size_t len)107 copy_fd(int out, FILE *in, size_t len)
108 {
109 char buffer[8192];
110 int rlen, alen;
111 int errors = 0;
112
113 rewind(in);
114 while (len > 0 && !errors) {
115 rlen = (len > sizeof (buffer)) ? sizeof (buffer) : len;
116 alen = read(fileno(in), buffer, rlen);
117 if (alen == rlen) {
118 if (write(out, buffer, alen) < alen)
119 errors++;
120 else
121 len -= alen;
122 }
123 else
124 errors++;
125 }
126 rewind(in);
127 return (errors);
128 }
129
130 int
proc_flushstdio(void)131 proc_flushstdio(void)
132 {
133 size_t len;
134 int errors = 0;
135
136 /*
137 * flush any pending IO
138 */
139
140 if (!initialized)
141 return (-1);
142
143 (void) fflush(stdout);
144 (void) fflush(stderr);
145
146 if ((len = ftell(stdout)) > 0)
147 errors += copy_fd(cached_stdout_fd, stdout, len);
148
149
150 if ((len = ftell(stderr)) > 0)
151 errors += copy_fd(cached_stderr_fd, stderr, len);
152
153 return (errors?-1:0);
154 }
155
156 int
proc_finistdio(void)157 proc_finistdio(void)
158 {
159 if (!initialized)
160 return (-1);
161
162 if (proc_flushstdio() != 0)
163 return (-1);
164
165 (void) dup2(cached_stdout_fd, 1);
166 (void) close(cached_stdout_fd);
167 (void) dup2(cached_stderr_fd, 2);
168 (void) close(cached_stderr_fd);
169
170 return (0);
171 }
172