source4/heimdal/lib/roken/vsyslog.c

   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