1 /* $NetBSD: vsyslog.c,v 1.2 2017/01/28 21:31:50 christos Exp $ */
2
3 /*
4 * Copyright (c) 1995 - 2000 Kungliga Tekniska Högskolan
5 * (Royal Institute of Technology, Stockholm, Sweden).
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 *
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 *
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 *
19 * 3. Neither the name of the Institute nor the names of its contributors
20 * may be used to endorse or promote products derived from this software
21 * without specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 */
35
36 #include <config.h>
37
38 #ifndef HAVE_VSYSLOG
39
40 #include <stdio.h>
41 #include <syslog.h>
42 #include <stdarg.h>
43
44 #include <krb5/roken.h>
45
46 /*
47 * the theory behind this is that we might be trying to call vsyslog
48 * when there's no memory left, and we should try to be as useful as
49 * possible. And the format string should say something about what's
50 * failing.
51 */
52
53 static void
simple_vsyslog(int pri,const char * fmt,va_list ap)54 simple_vsyslog(int pri, const char *fmt, va_list ap)
55 {
56 syslog (pri, "%s", fmt);
57 }
58
59 /*
60 * do like syslog but with a `va_list'
61 */
62
63 ROKEN_LIB_FUNCTION void ROKEN_LIB_CALL
vsyslog(int pri,const char * fmt,va_list ap)64 vsyslog(int pri, const char *fmt, va_list ap)
65 {
66 char *fmt2;
67 const char *p;
68 char *p2;
69 int ret;
70 int saved_errno = errno;
71 int fmt_len = strlen (fmt);
72 int fmt2_len = fmt_len;
73 char *buf;
74
75 fmt2 = malloc (fmt_len + 1);
76 if (fmt2 == NULL) {
77 simple_vsyslog (pri, fmt, ap);
78 return;
79 }
80
81 for (p = fmt, p2 = fmt2; *p != '\0'; ++p) {
82 if (p[0] == '%' && p[1] == 'm') {
83 const char *e = strerror (saved_errno);
84 int e_len = strlen (e);
85 char *tmp;
86 int pos;
87
88 pos = p2 - fmt2;
89 fmt2_len += e_len - 2;
90 tmp = realloc (fmt2, fmt2_len + 1);
91 if (tmp == NULL) {
92 free (fmt2);
93 simple_vsyslog (pri, fmt, ap);
94 return;
95 }
96 fmt2 = tmp;
97 p2 = fmt2 + pos;
98 memmove (p2, e, e_len);
99 p2 += e_len;
100 ++p;
101 } else
102 *p2++ = *p;
103 }
104 *p2 = '\0';
105
106 ret = vasprintf (&buf, fmt2, ap);
107 free (fmt2);
108 if (ret < 0 || buf == NULL) {
109 simple_vsyslog (pri, fmt, ap);
110 return;
111 }
112 syslog (pri, "%s", buf);
113 free (buf);
114 }
115 #endif
116