vsyslog.c revision 1.2 
1/*	$NetBSD: vsyslog.c,v 1.2 2017/01/28 21:31:50 christos Exp $	*/
2
3/*
4 * Copyright (c) 1995 - 2000 Kungliga Tekniska H��gskolan
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
53static void
54simple_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
63ROKEN_LIB_FUNCTION void ROKEN_LIB_CALL
64vsyslog(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