gnupg/jnlib/logging.c

/* logging.c -	useful logging functions
 * Copyright (C) 1998, 1999, 2000, 2001, 2003,
 *               2004 Free Software Foundation, Inc.
 *
 * This file is part of GnuPG.
 *
 * GnuPG is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * GnuPG is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
 */


/* This file should replace logger.c in the future - for now it is not
 * used by GnuPG but by GPA.
 * It is a quite simple implemenation but sufficient for most purposes.
 */

#include <config.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <stdarg.h>
#include <stddef.h>
#include <errno.h>
#include <time.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <unistd.h>
#ifdef __MINGW32__
#  include <io.h>
#endif

#define JNLIB_NEED_LOG_LOGV 1
#include "libjnlib-config.h"
#include "logging.h"


static FILE *logstream;
static int log_socket = -1;
static char prefix_buffer[80];
static int with_time;
static int with_prefix;
static int with_pid;
static int running_detached;
static int force_prefixes;

static int missing_lf;
static int errorcount;

#if 0
static void
write2stderr( const char *s )
{
    write( 2, s, strlen(s) );
}


static void
do_die(int rc, const char *text )
{
    write2stderr("\nFatal error: ");
    write2stderr(text);
    write2stderr("\n");
    abort();
}
#endif

int
log_get_errorcount (int clear)
{
    int n = errorcount;
    if( clear )
	errorcount = 0;
    return n;
}

void
log_inc_errorcount (void)
{
   errorcount++;
}


/* The follwing 3 functions are used by funopen to write logs to a
   socket. */
#if defined (HAVE_FOPENCOOKIE) || defined (HAVE_FUNOPEN)
struct fun_cookie_s {
  int fd;
  int quiet;
  char name[1];
};

/* Write NBYTES of BUF to file descriptor FD. */
static int
writen (int fd, const unsigned char *buf, size_t nbytes)
{
  size_t nleft = nbytes;
  int nwritten;
  
  while (nleft > 0)
    {
      nwritten = write (fd, buf, nleft);
      if (nwritten < 0 && errno == EINTR)
        continue;
      if (nwritten < 0)
        return -1;
      nleft -= nwritten;
      buf = buf + nwritten;
    }
  
  return 0;
}


static int 
fun_writer (void *cookie_arg, const char *buffer, size_t size)
{
  struct fun_cookie_s *cookie = cookie_arg;

  /* Note that we always try to reconnect to the socket but print
     error messages only the first time an error occured.  IF
     RUNNING_DETACHED is set we don't fall back to stderr and even do
     not print any error messages.  This is needed becuase detached
     processes often close stderr and my printing to fiel descriptor 2
     we might send the log message to a file not intended for logging
     (e.g. a pipe or network connection). */
  if (cookie->fd == -1)
    {
      /* Note yet open or meanwhile closed due to an error. */
      struct sockaddr_un addr;
      size_t addrlen;

      cookie->fd = socket (PF_LOCAL, SOCK_STREAM, 0);
      if (cookie->fd == -1)
        {
          if (!cookie->quiet && !running_detached)
            fprintf (stderr, "failed to create socket for logging: %s\n",
                     strerror(errno));
          goto failure;
        }
      log_socket = cookie->fd;
      
      memset (&addr, 0, sizeof addr);
      addr.sun_family = PF_LOCAL;
      strncpy (addr.sun_path, cookie->name, sizeof (addr.sun_path)-1);
      addr.sun_path[sizeof (addr.sun_path)-1] = 0;
      addrlen = (offsetof (struct sockaddr_un, sun_path)
                 + strlen (addr.sun_path) + 1);
      
      if (connect (cookie->fd, (struct sockaddr *) &addr, addrlen) == -1)
        {
          log_socket = -1;
          if (!cookie->quiet && !running_detached)
            fprintf (stderr, "can't connect to `%s': %s\n",
                     cookie->name, strerror(errno));
          close (cookie->fd);
          cookie->fd = -1;
          goto failure;
        }
      /* Connection established. */
      cookie->quiet = 0;
    }
  
  if (!writen (cookie->fd, buffer, size))
    return size; /* Okay. */ 

  log_socket = -1;
  if (!running_detached)
    fprintf (stderr, "error writing to `%s': %s\n",
             cookie->name, strerror(errno));
  close (cookie->fd);
  cookie->fd = -1;

 failure: 
  if (!running_detached)
    {
      if (!cookie->quiet)
        {
          fputs ("switching logging to stderr\n", stderr);
          cookie->quiet = 1;
        }
      
      fwrite (buffer, size, 1, stderr);
    }
  return size;
}

static int
fun_closer (void *cookie_arg)
{
  struct fun_cookie_s *cookie = cookie_arg;

  if (cookie->fd != -1)
    close (cookie->fd);
  jnlib_free (cookie);
  return 0;
}
#endif /* HAVE_FOPENCOOKIE || HAVE_FUNOPEN */




/* Set the file to write log to.  The sepcial names NULL and "_" may
   be used to select stderr and names formatted like
   "socket:///home/foo/mylogs" may be used to write the logging to the
   socket "/home/foo/mylogs".  If the connection to the socket fails
   or a write error is detected, the function writes to stderr and
   tries the next time again to connect the socket.
  */
void
log_set_file (const char *name) 
{
  FILE *fp;

  force_prefixes = 0;
  if (name && !strncmp (name, "socket://", 9) && name[9])
    {
#if defined (HAVE_FOPENCOOKIE)||  defined (HAVE_FUNOPEN)
      struct fun_cookie_s *cookie;

      cookie = jnlib_xmalloc (sizeof *cookie + strlen (name+9));
      cookie->fd = -1;
      cookie->quiet = 0;
      strcpy (cookie->name, name+9);

#ifdef HAVE_FOPENCOOKIE
      {
        cookie_io_functions_t io = { NULL };
        io.write = fun_writer;
        io.close = fun_closer;

        fp = fopencookie (cookie, "w", io);
      }
#else /*!HAVE_FOPENCOOKIE*/
      {
        fp = funopen (cookie, NULL, fun_writer, NULL, fun_closer);
      }
#endif /*!HAVE_FOPENCOOKIE*/
#else /* Neither fopencookie nor funopen. */
      {
        fprintf (stderr, "system does not support logging to a socket - "
                 "using stderr\n");
        fp = stderr;
      }
#endif /* Neither fopencookie nor funopen. */

      /* We always need to print the prefix and the pid, so that the
         server reading the socket can do something meanigful. */
      force_prefixes = 1;
    }
  else
    fp = (name && strcmp(name,"-"))? fopen (name, "a") : stderr;
  if (!fp)
    {
      fprintf (stderr, "failed to open log file `%s': %s\n",
               name? name:"[stderr]", strerror(errno));
      return;
    }
  setvbuf (fp, NULL, _IOLBF, 0);
  
  if (logstream && logstream != stderr && logstream != stdout)
    fclose (logstream);
  logstream = fp;
  missing_lf = 0;
}


void
log_set_fd (int fd)
{
  FILE *fp;

  force_prefixes = 0;
  if (fd == 1)
    fp = stdout;
  else if (fd == 2)
    fp = stderr;
  else
    fp = fdopen (fd, "a");
  if (!fp)
    {
      fprintf (stderr, "failed to fdopen log fd %d: %s\n",
               fd, strerror(errno));
      return;
    }
  setvbuf (fp, NULL, _IOLBF, 0);
  
  if (logstream && logstream != stderr && logstream != stdout)
    fclose( logstream);
  logstream = fp;
  missing_lf = 0;
}


void
log_set_prefix (const char *text, unsigned int flags)
{
  if (text)
    {
      strncpy (prefix_buffer, text, sizeof (prefix_buffer)-1);
      prefix_buffer[sizeof (prefix_buffer)-1] = 0;
    }
  
  with_prefix = (flags & JNLIB_LOG_WITH_PREFIX);
  with_time = (flags & JNLIB_LOG_WITH_TIME);
  with_pid  = (flags & JNLIB_LOG_WITH_PID);
  running_detached = (flags & JNLIB_LOG_RUN_DETACHED);
}


const char *
log_get_prefix (unsigned int *flags)
{
  if (flags)
    {
      *flags = 0;
      if (with_prefix)
        *flags |= JNLIB_LOG_WITH_PREFIX;
      if (with_time)
        *flags |= JNLIB_LOG_WITH_TIME;
      if (with_pid)
        *flags |= JNLIB_LOG_WITH_PID;
      if (running_detached)
        *flags |= JNLIB_LOG_RUN_DETACHED;
    }
  return prefix_buffer;
}

/* This function returns true if the file descriptor FD is in use for
   logging.  This is preferable over a test using log_get_fd in that
   it allows the logging code to use more then one file descriptor. */
int
log_test_fd (int fd)
{
  if (fileno (logstream?logstream:stderr) == fd)
    return 1;
  if (log_socket == fd)
    return 1;
  return 0;
}

int
log_get_fd ()
{
  return fileno(logstream?logstream:stderr);
}

FILE *
log_get_stream ()
{
  return logstream?logstream:stderr;
}


static void
do_logv (int level, const char *fmt, va_list arg_ptr)
{
  if (!logstream)
    logstream = stderr;

  if (missing_lf && level != JNLIB_LOG_CONT)
    putc('\n', logstream );
  missing_lf = 0;

  if (level != JNLIB_LOG_CONT)
    { /* Note this does not work for multiple line logging as we would
       * need to print to a buffer first */
      if (with_time && !force_prefixes)
        {
          struct tm *tp;
          time_t atime = time (NULL);
          
          tp = localtime (&atime);
          fprintf (logstream, "%04d-%02d-%02d %02d:%02d:%02d ",
                   1900+tp->tm_year, tp->tm_mon+1, tp->tm_mday,
                   tp->tm_hour, tp->tm_min, tp->tm_sec );
        }
      if (with_prefix || force_prefixes)
        fputs (prefix_buffer, logstream);
      if (with_pid || force_prefixes)
        fprintf (logstream, "[%u]", (unsigned int)getpid ());
      if (!with_time || force_prefixes)
        putc (':', logstream);
      /* A leading backspace suppresses the extra space so that we can
         correctly output, programname, filename and linenumber. */
      if (fmt && *fmt == '\b')
        fmt++;
      else
        putc (' ', logstream);
    }

  switch (level)
    {
    case JNLIB_LOG_BEGIN: break;
    case JNLIB_LOG_CONT: break;
    case JNLIB_LOG_INFO: break;
    case JNLIB_LOG_WARN: break;
    case JNLIB_LOG_ERROR: break;
    case JNLIB_LOG_FATAL: fputs("Fatal: ",logstream ); break;
    case JNLIB_LOG_BUG: fputs("Ohhhh jeeee: ", logstream); break;
    case JNLIB_LOG_DEBUG: fputs("DBG: ", logstream ); break;
    default: fprintf(logstream,"[Unknown log level %d]: ", level ); break;
    }


  if (fmt)
    {
      vfprintf(logstream,fmt,arg_ptr) ;
      if (*fmt && fmt[strlen(fmt)-1] != '\n')
        missing_lf = 1;
    }

  if (level == JNLIB_LOG_FATAL)
    exit(2);
  if (level == JNLIB_LOG_BUG)
    abort();
}

static void
do_log( int level, const char *fmt, ... )
{
    va_list arg_ptr ;

    va_start( arg_ptr, fmt ) ;
    do_logv( level, fmt, arg_ptr );
    va_end(arg_ptr);
}


void
log_logv (int level, const char *fmt, va_list arg_ptr)
{
  do_logv (level, fmt, arg_ptr);
}

void
log_info( const char *fmt, ... )
{
    va_list arg_ptr ;

    va_start( arg_ptr, fmt ) ;
    do_logv( JNLIB_LOG_INFO, fmt, arg_ptr );
    va_end(arg_ptr);
}

void
log_error( const char *fmt, ... )
{
    va_list arg_ptr ;

    va_start( arg_ptr, fmt ) ;
    do_logv( JNLIB_LOG_ERROR, fmt, arg_ptr );
    va_end(arg_ptr);
    /* protect against counter overflow */
    if( errorcount < 30000 )
	errorcount++;
}


void
log_fatal( const char *fmt, ... )
{
    va_list arg_ptr ;

    va_start( arg_ptr, fmt ) ;
    do_logv( JNLIB_LOG_FATAL, fmt, arg_ptr );
    va_end(arg_ptr);
    abort(); /* never called, but it makes the compiler happy */
}

void
log_bug( const char *fmt, ... )
{
    va_list arg_ptr ;

    va_start( arg_ptr, fmt ) ;
    do_logv( JNLIB_LOG_BUG, fmt, arg_ptr );
    va_end(arg_ptr);
    abort(); /* never called, but it makes the compiler happy */
}

void
log_debug( const char *fmt, ... )
{
    va_list arg_ptr ;

    va_start( arg_ptr, fmt ) ;
    do_logv( JNLIB_LOG_DEBUG, fmt, arg_ptr );
    va_end(arg_ptr);
}


void
log_printf (const char *fmt, ...)
{
  va_list arg_ptr;

  va_start (arg_ptr, fmt);
  do_logv (fmt ? JNLIB_LOG_CONT : JNLIB_LOG_BEGIN, fmt, arg_ptr);
  va_end (arg_ptr);
}

/* Print a hexdump of BUFFER.  With TEXT of NULL print just the raw
   dump, with TEXT just an empty string, print a trailing linefeed,
   otherwise print an entire debug line. */
void
log_printhex (const char *text, const void *buffer, size_t length)
{
  if (text && *text)
    log_debug ("%s ", text);
  if (length)
    {
      const unsigned char *p = buffer;
      log_printf ("%02X", *p);
      for (length--, p++; length--; p++)
        log_printf (" %02X", *p);
    }
  if (text)
    log_printf ("\n");
}


#if __GNUC__ > 2 || (__GNUC__ == 2 && __GNUC_MINOR__ >= 5 )
void
bug_at( const char *file, int line, const char *func )
{
    do_log( JNLIB_LOG_BUG,
	     ("... this is a bug (%s:%d:%s)\n"), file, line, func );
    abort(); /* never called, but it makes the compiler happy */
}
#else
void
bug_at( const char *file, int line )
{
    do_log( JNLIB_LOG_BUG,
	     _("you found a bug ... (%s:%d)\n"), file, line);
    abort(); /* never called, but it makes the compiler happy */
}
#endif