sysdeps/posix/libc_fatal.c

   1 /* Copyright (C) 1993,1994,1995,1997,2000,2004 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, write to the Free
  16    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  17    02111-1307 USA.  */
  18
  19 #include <errno.h>
  20 #include <fcntl.h>
  21 #include <paths.h>
  22 #include <stdarg.h>
  23 #include <stdbool.h>
  24 #include <stdio.h>
  25 #include <stdlib.h>
  26 #include <string.h>
  27 #include <sysdep.h>
  28 #include <unistd.h>
  29 #include <sys/syslog.h>
  30 #include <not-cancel.h>
  31
  32 #ifdef FATAL_PREPARE_INCLUDE
  33 #include FATAL_PREPARE_INCLUDE
  34 #endif
  35
  36 struct str_list
  37 {
  38   const char *str;
  39   size_t len;
  40   struct str_list *next;
  41 };
  42
  43
  44 /* Abort with an error message.  */
  45 void
  46 __libc_message (int do_abort, const char *fmt, ...)
  47 {
  48   va_list ap;
  49   va_list ap_copy;
  50   int fd = -1;
  51
  52   va_start (ap, fmt);
  53   va_copy (ap_copy, ap);
  54
  55 #ifdef FATAL_PREPARE
  56   FATAL_PREPARE;
  57 #endif
  58
  59   /* Open a descriptor for /dev/tty unless the user explicitly
  60      requests errors on standard error.  */
  61   const char *on_2 = __secure_getenv ("LIBC_FATAL_STDERR_");
  62   if (on_2 == NULL || *on_2 == '\0')
  63     fd = open_not_cancel_2 (_PATH_TTY, O_RDWR | O_NOCTTY | O_NDELAY);
  64
  65   if (fd == -1)
  66     fd = STDERR_FILENO;
  67
  68   struct str_list *list = NULL;
  69   int nlist = 0;
  70
  71   const char *cp = fmt;
  72   while (*cp != '\0')
  73     {
  74       /* Find the next "%s" or the end of the string.  */
  75       char *next = cp;
  76       while (next[0] != '%' || next[1] != 's')
  77         {
  78           next = __strchrnul (next + 1, '%');
  79
  80           if (next[0] == '\0')
  81             break;
  82         }
  83
  84       /* Determine what to print.  */
  85       const char *str;
  86       size_t len;
  87       if (cp[0] == '%' && cp[1] == 's')
  88         {
  89           str = va_arg (ap, const char *);
  90           len = strlen (str);
  91           cp += 2;
  92         }
  93       else
  94         {
  95           str = cp;
  96           len = next - cp;
  97           cp = next;
  98         }
  99
 100       struct str_list *newp = alloca (sizeof (struct str_list));
 101       newp->str = str;
 102       newp->len = len;
 103       newp->next = list;
 104       list = newp;
 105       ++nlist;
 106     }
 107
 108   bool written = false;
 109   if (nlist > 0)
 110     {
 111       struct iovec *iov = alloca (nlist * sizeof (struct iovec));
 112       ssize_t total = 0;
 113
 114       for (int cnt = nlist - 1; cnt >= 0; --cnt)
 115         {
 116           iov[cnt].iov_base = list->str;
 117           iov[cnt].iov_len = list->len;
 118           total += list->len;
 119           list = list->next;
 120         }
 121
 122       if (TEMP_FAILURE_RETRY (__writev (fd, iov, nlist)) == total)
 123         written = true;
 124     }
 125
 126   va_end (ap);
 127
 128   /* If we  had no success writing the message, use syslog.  */
 129   if (! written)
 130     vsyslog (LOG_ERR, fmt, ap_copy);
 131
 132   if (do_abort()
 133       /* Kill the application.  */
 134       abort ();
 135 }
 136
 137
 138 void
 139 __libc_fatal (message)
 140      const char *message;
 141 {
 142   __libc_message (1, "%s", message);
 143 }
 144 libc_hidden_def (__libc_fatal)