1 /*	$NetBSD: vsyslog.c,v 1.1.1.1 2011/04/13 18:15:44 elric 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