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