xref: /freebsd/crypto/heimdal/lib/roken/vsyslog.c (revision f81cdf24ba5436367377f7c8e8f51f6df2a75ca7)
1 /*
2  * Copyright (c) 1995 - 2000 Kungliga Tekniska Högskolan
3  * (Royal Institute of Technology, Stockholm, Sweden).
4  * All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  *
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  *
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * 3. Neither the name of the Institute nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  */
33 
34 #include <config.h>
35 
36 #ifndef HAVE_VSYSLOG
37 
38 #include <stdio.h>
39 #include <syslog.h>
40 #include <stdarg.h>
41 
42 #include "roken.h"
43 
44 /*
45  * the theory behind this is that we might be trying to call vsyslog
46  * when there's no memory left, and we should try to be as useful as
47  * possible.  And the format string should say something about what's
48  * failing.
49  */
50 
51 static void
52 simple_vsyslog(int pri, const char *fmt, va_list ap)
53 {
54     syslog (pri, "%s", fmt);
55 }
56 
57 /*
58  * do like syslog but with a `va_list'
59  */
60 
61 ROKEN_LIB_FUNCTION void ROKEN_LIB_CALL
62 vsyslog(int pri, const char *fmt, va_list ap)
63 {
64     char *fmt2;
65     const char *p;
66     char *p2;
67     int ret;
68     int saved_errno = errno;
69     int fmt_len  = strlen (fmt);
70     int fmt2_len = fmt_len;
71     char *buf;
72 
73     fmt2 = malloc (fmt_len + 1);
74     if (fmt2 == NULL) {
75 	simple_vsyslog (pri, fmt, ap);
76 	return;
77     }
78 
79     for (p = fmt, p2 = fmt2; *p != '\0'; ++p) {
80 	if (p[0] == '%' && p[1] == 'm') {
81 	    const char *e = strerror (saved_errno);
82 	    int e_len = strlen (e);
83 	    char *tmp;
84 	    int pos;
85 
86 	    pos = p2 - fmt2;
87 	    fmt2_len += e_len - 2;
88 	    tmp = realloc (fmt2, fmt2_len + 1);
89 	    if (tmp == NULL) {
90 		free (fmt2);
91 		simple_vsyslog (pri, fmt, ap);
92 		return;
93 	    }
94 	    fmt2 = tmp;
95 	    p2   = fmt2 + pos;
96 	    memmove (p2, e, e_len);
97 	    p2 += e_len;
98 	    ++p;
99 	} else
100 	    *p2++ = *p;
101     }
102     *p2 = '\0';
103 
104     ret = vasprintf (&buf, fmt2, ap);
105     free (fmt2);
106     if (ret < 0 || buf == NULL) {
107 	simple_vsyslog (pri, fmt, ap);
108 	return;
109     }
110     syslog (pri, "%s", buf);
111     free (buf);
112 }
113 #endif
114