added klogd.c

1 files changed, 1178 insertions, 0 deletions

diff --git a/klogd.c b/klogd.c
new file mode 100644
index 00000000..9dfa8b14
--- /dev/null
+++ b/klogd.c
@@ -0,0 +1,1178 @@
+/*
+    klogd.c - main program for Linux kernel log daemon.
+    Copyright (c) 1995  Dr. G.W. Wettstein <greg@wind.rmcc.com>
+
+    This file is part of the sysklogd package, a kernel and system log daemon.
+
+    This program 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.
+
+    This program 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., 675 Mass Ave, Cambridge, MA 02139, USA.
+*/
+
+/*
+ * Steve Lord (lord@cray.com) 7th Nov 92
+ *
+ * Modified to check for kernel info by Dr. G.W. Wettstein 02/17/93.
+ *
+ * Fri Mar 12 16:53:56 CST 1993:  Dr. Wettstein
+ * 	Modified LogLine to use a newline as the line separator in
+ *	the kernel message buffer.
+ *
+ *	Added debugging code to dump the contents of the kernel message
+ *	buffer at the start of the LogLine function.
+ *
+ * Thu Jul 29 11:40:32 CDT 1993:  Dr. Wettstein
+ *	Added syscalls to turn off logging of kernel messages to the
+ *	console when klogd becomes responsible for kernel messages.
+ *
+ *	klogd now catches SIGTERM and SIGKILL signals.  Receipt of these
+ *	signals cases the clean_up function to be called which shuts down
+ *	kernel logging and re-enables logging of messages to the console.
+ *
+ * Sat Dec 11 11:54:22 CST 1993:  Dr. Wettstein
+ *	Added fixes to allow compilation with no complaints with -Wall.
+ *
+ *      When the daemon catches a fatal signal (SIGTERM, SIGKILL) a 
+ *	message is output to the logfile advising that the daemon is
+ *	going to terminate.
+ *
+ * Thu Jan  6 11:54:10 CST 1994:  Dr. Wettstein
+ *	Major re-write/re-organization of the code.
+ *
+ *	Klogd now assigns kernel messages to priority levels when output
+ *	to the syslog facility is requested.  The priority level is
+ *	determined by decoding the prioritization sequence which is
+ *	tagged onto the start of the kernel messages.
+ *
+ *	Added the following program options: -f arg -c arg -s -o -d
+ *
+ *		The -f switch can be used to specify that output should
+ *		be written to the named file.
+ *
+ *		The -c switch is used to specify the level of kernel
+ *		messages which are to be directed to the console.
+ *
+ *		The -s switch causes the program to use the syscall
+ *		interface to the kernel message facility.  This can be
+ *		used to override the presence of the /proc filesystem.
+ *
+ *		The -o switch causes the program to operate in 'one-shot'
+ *		mode.  A single call will be made to read the complete
+ *		kernel buffer.  The contents of the buffer will be
+ *		output and the program will terminate.
+ *
+ *		The -d switch causes 'debug' mode to be activated.  This
+ *		will cause the daemon to generate LOTS of output to stderr.
+ *
+ *	The buffer decomposition function (LogLine) was re-written to
+ *	squash a bug which was causing only partial kernel messages to
+ *	be written to the syslog facility.
+ *
+ *	The signal handling code was modified to properly differentiate
+ *	between the STOP and TSTP signals.
+ *
+ *	Added pid saving when the daemon detaches into the background.  Thank
+ *	you to Juha Virtanen (jiivee@hut.fi) for providing this patch.
+ *
+ * Mon Feb  6 07:31:29 CST 1995:  Dr. Wettstein
+ *	Significant re-organization of the signal handling code.  The
+ *	signal handlers now only set variables.  Not earth shaking by any
+ *	means but aesthetically pleasing to the code purists in the group.
+ *
+ *	Patch to make things more compliant with the file system standards.
+ *	Thanks to Chris Metcalf for prompting this helpful change.
+ *
+ *	The routines responsible for reading the kernel log sources now
+ *	initialize the buffers before reading.  I think that this will
+ *	solve problems with non-terminated kernel messages producing
+ *	output of the form:  new old old old
+ *
+ *	This may also help influence the occassional reports of klogd
+ *	failing under significant load.  I think that the jury may still
+ *	be out on this one though.  My thanks to Joerg Ahrens for initially
+ *	tipping me off to the source of this problem.  Also thanks to
+ *	Michael O'Reilly for tipping me off to the best fix for this problem.
+ *	And last but not least Mark Lord for prompting me to try this as
+ *	a means of attacking the stability problem.
+ *
+ *	Specifying a - as the arguement to the -f switch will cause output
+ *	to be directed to stdout rather than a filename of -.  Thanks to
+ *	Randy Appleton for a patch which prompted me to do this.
+ *
+ * Wed Feb 22 15:37:37 CST 1995:  Dr. Wettstein
+ *	Added version information to logging startup messages.
+ *
+ * Wed Jul 26 18:57:23 MET DST 1995: Martin Schulze
+ *	Added an commandline argument "-n" to avoid forking. This obsoletes
+ *	the compiler define NO_FORK. It's more useful to have this as an
+ *	argument as there are many binary versions and one doesn't need to
+ *	recompile the daemon.
+ *
+ * Thu Aug 10 19:01:08 MET DST 1995: Martin Schulze
+ *	Added my pidfile.[ch] to it to perform a better handling with pidfiles.
+ *	Now both, syslogd and klogd, can only be started once. They check the
+ *	pidfile.
+ *
+ * Fri Nov 17 15:05:43 CST 1995:  Dr. Wettstein
+ *	Added support for kernel address translation.  This required moving
+ *	some definitions and includes to the new klogd.h file.  Some small
+ *	code cleanups and modifications.
+ *
+ * Mon Nov 20 10:03:39 MET 1995
+ *	Added -v option to print the version and exit.
+ *
+ * Thu Jan 18 11:19:46 CST 1996:  Dr. Wettstein
+ *	Added suggested patches from beta-testers.  These address two
+ *	two problems.  The first is segmentation faults which occur with
+ *	the ELF libraries.  This was caused by passing a null pointer to
+ *	the strcmp function.
+ *
+ *	Added a second patch to remove the pidfile as part of the
+ *	termination cleanup sequence.  This minimizes the potential for
+ *	conflicting pidfiles causing immediate termination at boot time.
+ *	
+ * Wed Aug 21 09:13:03 CDT 1996:  Dr. Wettstein
+ *	Added ability to reload static symbols and kernel module symbols
+ *      under control of SIGUSR1 and SIGUSR2 signals.
+ *
+ *	Added -p switch to select 'paranoid' behavior with respect to the
+ *	loading of kernel module symbols.
+ *
+ *	Informative line now printed whenever a state change occurs due
+ *	to signal reception by the daemon.
+ *
+ *	Added the -i and -I command line switches to signal the currently
+ *	executing daemon.
+ *
+ * Tue Nov 19 10:15:36 PST 1996: Leland Olds <olds@eskimo.com>
+ *	Corrected vulnerability to buffer overruns by rewriting LogLine
+ *	routine.  Obscenely long kernel messages will now be broken up
+ *	into lines no longer than LOG_LINE_LENGTH.
+ *
+ *	The last version of LogLine was vulnerable to buffer overruns:
+ *	- Kernel messages longer than LOG_LINE_LENGTH caused a buffer
+ *	  overrun.
+ *	- If a line was determined to be shorter than LOG_LINE_LENGTH,
+ *	  the routine "ExpandKadds" could cause the line grow by
+ *	  an unknown amount and overrun a buffer.
+ *	I turned these routines into a little parsing state machine that
+ *	should not have these problems.
+ *
+ * Sun Jun 15 16:23:29 MET DST 1997: Michael Alan Dorman
+ *	Some more glibc patches made by <mdorman@debian.org>.
+ *
+ * Thu Aug 21 12:11:27 MET DST 1997: Martin Schulze <joey@infodrom.north.de>
+ *	Fixed little mistake which prevented klogd from accepting a
+ *	console log 
+ *
+ * Fri Jan  9 00:39:52 CET 1998: Martin Schulze <joey@infodrom.north.de>
+ *	Changed the behaviour of klogd when receiving a terminate
+ *	signal.  Now the program terminates immediately instead of
+ *	completing the receipt of a kernel message, i.e the read()
+ *	call.  The old behaveiour could result in klogd being
+ *	recognized as being undead, because it'll only die after a
+ *	message has been received.
+ *
+ * Fri Jan  9 11:03:48 CET 1998: Martin Schulze <joey@infodrom.north.de>
+ *	Corrected some code that caused klogd to dump core when
+ *	receiving messages containing '%', some of them exist in
+ *	2.1.78.  Thanks to Chu-yeon Park <kokids@doit.ajou.ac.kr> for
+ *	informing me.
+ *
+ * Fri Jan  9 23:38:19 CET 1998: Florian La Roche <florian@knorke.saar.de>
+ *	Added -x switch to omit EIP translation and System.map evaluation.
+ *
+ * Sun Jan 25 20:47:46 CET 1998: Martin Schulze <joey@infodrom.north.de>
+ *	As the bug covering the %'s introduced a problem with
+ *	unevaluated priorities I've worked out a real fix that strips
+ *	%'s to an even number which is harmless for printf.
+ *
+ * Sat Oct 10 20:01:48 CEST 1998: Martin Schulze <joey@infodrom.north.de>
+ *	Added support for TESTING define which will turn klogd into
+ *	stdio-mode used for debugging.
+ *
+ * Mon Apr 13 18:18:45 CEST 1998: Martin Schulze <joey@infodrom.north.de>
+ *	Modified System.map read function to try all possible map
+ *	files until a file with matching version is found.  Added support for
+ *	Debian release.
+ *
+ * Mon Oct 12 13:01:27 MET DST 1998: Martin Schulze <joey@infodrom.north.de>
+ *	Used unsigned long and strtoul() to resolve kernel oops symbols.
+ *
+ * Sun Jan  3 18:38:03 CET 1999: Martin Schulze <joey@infodrom.north.de>
+ *	Shortened LOG_LINE_LENGTH in order to get long lines splitted
+ *	up earlier and syslogd has a better chance concatenating them
+ *	together again.
+ *
+ * Sat Aug 21 12:27:02 CEST 1999: Martin Schulze <joey@infodrom.north.de>
+ *	Skip newline when reading in messages.
+ *
+ * Tue Sep 12 22:14:33 CEST 2000: Martin Schulze <joey@infodrom.ffis.de>
+ *	Don't feed a buffer directly to a printf-type routine, use
+ *	"%s" as format string instead.  Thanks to Jouko Pynnönen
+ *	<jouko@solutions.fi> for pointing this out.
+ *
+ * Tue Sep 12 22:44:57 CEST 2000: Martin Schulze <joey@infodrom.ffis.de>
+ *      Commandline option `-2': When symbols are expanded, print the
+ *	line twice.  Once with addresses converted to symbols, once with the
+ *	raw text.  Allows external programs such as ksymoops do their own
+ *	processing on the original data.  Thanks to Keith Owens
+ *	<kaos@ocs.com.au> for the patch.
+ *
+ * Mon Sep 18 09:32:27 CEST 2000: Martin Schulze <joey@infodrom.ffis.de>
+ *	Added patch to fix priority decoding after moving kernel
+ *	messgages into "%s".  Thanks to Solar Designer
+ *	<solar@false.com> for the patch.
+ *
+ * Sun Mar 11 20:23:44 CET 2001: Martin Schulze <joey@infodrom.ffis.de>
+ *	Stop LogLine() from being called with wrong argument when a
+ *	former calculation failed already.  Thanks to Thomas Roessler
+ *	<roessler@does-not-exist.org> for providing a patch.
+ *
+ *	Ignore zero bytes, no busy loop is entered anymore.  Several
+ *	people have submitted patches: Troels Walsted Hansen
+ *	<troels@thule.no>, Wolfgang Oertl <Wolfgang.Oertl@uibk.ac.at>
+ *	and Thomas Roessler.
+ */
+
+
+/* Includes. */
+#include <unistd.h>
+#include <signal.h>
+#include <errno.h>
+#include <sys/fcntl.h>
+#include <sys/stat.h>
+#if !defined(__GLIBC__)
+#include <linux/time.h>
+#endif /* __GLIBC__ */
+#include <stdarg.h>
+#include <paths.h>
+#include <stdlib.h>
+#include "klogd.h"
+#include "ksyms.h"
+#ifndef TESTING
+#include "pidfile.h"
+#endif
+#include "version.h"
+
+#define __LIBRARY__
+#include <linux/unistd.h>
+#if !defined(__GLIBC__)
+# define __NR_ksyslog __NR_syslog
+_syscall3(int,ksyslog,int, type, char *, buf, int, len);
+#else
+#include <sys/klog.h>
+#define ksyslog klogctl
+#endif
+
+#ifndef _PATH_KLOG
+#define _PATH_KLOG  "/proc/kmsg"
+#endif
+
+#define LOG_BUFFER_SIZE 4096
+#define LOG_LINE_LENGTH 1000
+
+#ifndef TESTING
+#if defined(FSSTND)
+static char	*PidFile = _PATH_VARRUN "klogd.pid";
+#else
+static char	*PidFile = "/etc/klogd.pid";
+#endif
+#endif
+
+static int	kmsg,
+		change_state = 0,
+		terminate = 0,
+		caught_TSTP = 0,
+		reload_symbols = 0,
+		console_log_level = 6;
+
+static int	use_syscall = 0,
+		one_shot = 0,
+		symbol_lookup = 1,
+		no_fork = 0;	/* don't fork - don't run in daemon mode */
+
+static char	*symfile = (char *) 0,
+		log_buffer[LOG_BUFFER_SIZE];
+
+static FILE *output_file = (FILE *) 0;
+
+static enum LOGSRC {none, proc, kernel} logsrc;
+
+int debugging = 0;
+int symbols_twice = 0;
+
+
+/* Function prototypes. */
+extern int ksyslog(int type, char *buf, int len);
+static void CloseLogSrc(void);
+extern void restart(int sig);
+extern void stop_logging(int sig);
+extern void stop_daemon(int sig);
+extern void reload_daemon(int sig);
+static void Terminate(void);
+static void SignalDaemon(int);
+static void ReloadSymbols(void);
+static void ChangeLogging(void);
+static enum LOGSRC GetKernelLogSrc(void);
+static void LogLine(char *ptr, int len);
+static void LogKernelLine(void);
+static void LogProcLine(void);
+extern int main(int argc, char *argv[]);
+
+
+static void CloseLogSrc()
+
+{
+	/* Turn on logging of messages to console. */
+  	ksyslog(7, NULL, 0);
+  
+        /* Shutdown the log sources. */
+	switch ( logsrc )
+	{
+	    case kernel:
+		ksyslog(0, 0, 0);
+		Syslog(LOG_INFO, "Kernel logging (ksyslog) stopped.");
+		break;
+            case proc:
+		close(kmsg);
+		Syslog(LOG_INFO, "Kernel logging (proc) stopped.");
+		break;
+	    case none:
+		break;
+	}
+
+	if ( output_file != (FILE *) 0 )
+		fflush(output_file);
+	return;
+}
+
+
+void restart(sig)
+	
+	int sig;
+
+{
+	signal(SIGCONT, restart);
+	change_state = 1;
+	caught_TSTP = 0;
+	return;
+}
+
+
+void stop_logging(sig)
+
+	int sig;
+	
+{
+	signal(SIGTSTP, stop_logging);
+	change_state = 1;
+	caught_TSTP = 1;
+	return;
+}
+
+
+void stop_daemon(sig)
+
+	int sig;
+
+{
+	Terminate();
+	return;
+}
+
+
+void reload_daemon(sig)
+
+     int sig;
+
+{
+	change_state = 1;
+	reload_symbols = 1;
+
+
+	if ( sig == SIGUSR2 )
+	{
+		++reload_symbols;
+		signal(SIGUSR2, reload_daemon);
+	}
+	else
+		signal(SIGUSR1, reload_daemon);
+		
+	return;
+}
+
+
+static void Terminate()
+
+{
+	CloseLogSrc();
+	Syslog(LOG_INFO, "Kernel log daemon terminating.");
+	sleep(1);
+	if ( output_file != (FILE *) 0 )
+		fclose(output_file);
+	closelog();
+#ifndef TESTING
+	(void) remove_pid(PidFile);
+#endif
+	exit(1);
+}
+
+static void SignalDaemon(sig)
+
+     int sig;
+
+{
+#ifndef TESTING
+	auto int pid = check_pid(PidFile);
+
+	kill(pid, sig);
+#else
+	kill(getpid(), sig);
+#endif
+	return;
+}
+
+
+static void ReloadSymbols()
+
+{
+	if (symbol_lookup) {
+		if ( reload_symbols > 1 )
+			InitKsyms(symfile);
+		InitMsyms();
+	}
+	reload_symbols = change_state = 0;
+	return;
+}
+
+
+static void ChangeLogging(void)
+
+{
+	/* Terminate kernel logging. */
+	if ( terminate == 1 )
+		Terminate();
+
+	/* Indicate that something is happening. */
+	Syslog(LOG_INFO, "klogd %s.%s, ---------- state change ----------\n", \
+	       VERSION, PATCHLEVEL);
+
+	/* Reload symbols. */
+	if ( reload_symbols > 0 )
+	{
+		ReloadSymbols();
+		return;
+	}
+
+	/* Stop kernel logging. */
+	if ( caught_TSTP == 1 )
+	{
+		CloseLogSrc();
+		logsrc = none;
+		change_state = 0;
+		return;
+	}
+		
+	/*
+	 * The rest of this function is responsible for restarting
+	 * kernel logging after it was stopped.
+	 *
+	 * In the following section we make a decision based on the
+	 * kernel log state as to what is causing us to restart.  Somewhat
+	 * groady but it keeps us from creating another static variable.
+	 */
+	if ( logsrc != none )
+	{
+		Syslog(LOG_INFO, "Kernel logging re-started after SIGSTOP.");
+		change_state = 0;
+		return;
+	}
+
+	/* Restart logging. */
+	logsrc = GetKernelLogSrc();
+	change_state = 0;
+	return;
+}
+
+
+static enum LOGSRC GetKernelLogSrc(void)
+
+{
+	auto struct stat sb;
+
+
+	/* Set level of kernel console messaging.. */
+	if ( (ksyslog(8, NULL, console_log_level) < 0) && \
+	     (errno == EINVAL) )
+	{
+		/*
+		 * An invalid arguement error probably indicates that
+		 * a pre-0.14 kernel is being run.  At this point we
+		 * issue an error message and simply shut-off console
+		 * logging completely.
+		 */
+		Syslog(LOG_WARNING, "Cannot set console log level - disabling "
+		       "console output.");
+		ksyslog(6, NULL, 0);
+	}
+
+	/*
+	 * First do a stat to determine whether or not the proc based
+	 * file system is available to get kernel messages from.
+	 */
+	if ( use_syscall ||
+	    ((stat(_PATH_KLOG, &sb) < 0) && (errno == ENOENT)) )
+	{
+	  	/* Initialize kernel logging. */
+	  	ksyslog(1, NULL, 0);
+#ifdef DEBRELEASE
+		Syslog(LOG_INFO, "klogd %s.%s#%s, log source = ksyslog "
+		       "started.", VERSION, PATCHLEVEL, DEBRELEASE);
+#else
+		Syslog(LOG_INFO, "klogd %s.%s, log source = ksyslog "
+		       "started.", VERSION, PATCHLEVEL);
+#endif
+		return(kernel);
+	}
+
+#ifndef TESTING
+	if ( (kmsg = open(_PATH_KLOG, O_RDONLY)) < 0 )
+	{
+		fprintf(stderr, "klogd: Cannot open proc file system, " \
+			"%d - %s.\n", errno, strerror(errno));
+		ksyslog(7, NULL, 0);
+		exit(1);
+	}
+#else
+	kmsg = fileno(stdin);
+#endif
+
+#ifdef DEBRELEASE
+	Syslog(LOG_INFO, "klogd %s.%s#%s, log source = %s started.", \
+	       VERSION, PATCHLEVEL, DEBRELEASE, _PATH_KLOG);
+#else
+	Syslog(LOG_INFO, "klogd %s.%s, log source = %s started.", \
+	       VERSION, PATCHLEVEL, _PATH_KLOG);
+#endif
+	return(proc);
+}
+
+
+extern void Syslog(int priority, char *fmt, ...)
+
+{
+	va_list ap;
+	char *argl;
+
+	if ( debugging )
+	{
+		fputs("Logging line:\n", stderr);
+		fprintf(stderr, "\tLine: %s\n", fmt);
+		fprintf(stderr, "\tPriority: %d\n", priority);
+	}
+
+	/* Handle output to a file. */
+	if ( output_file != (FILE *) 0 )
+	{
+		va_start(ap, fmt);
+		vfprintf(output_file, fmt, ap);
+		va_end(ap);
+		fputc('\n', output_file);
+		fflush(output_file);
+		if (!one_shot)
+			fsync(fileno(output_file));
+		return;
+	}
+	
+	/* Output using syslog. */
+	if (!strcmp(fmt, "%s"))
+	{
+		va_start(ap, fmt);
+		argl = va_arg(ap, char *);
+		if (argl[0] == '<' && argl[1] && argl[2] == '>')
+		{
+			switch ( argl[1] )
+			{
+			case '0':
+				priority = LOG_EMERG;
+				break;
+			case '1':
+				priority = LOG_ALERT;
+				break;
+			case '2':
+				priority = LOG_CRIT;
+				break;
+			case '3':
+				priority = LOG_ERR;
+				break;
+			case '4':
+				priority = LOG_WARNING;
+				break;
+			case '5':
+				priority = LOG_NOTICE;
+				break;
+			case '6':
+				priority = LOG_INFO;
+				break;
+			case '7':
+			default:
+				priority = LOG_DEBUG;
+			}
+			argl += 3;
+		}
+		syslog(priority, fmt, argl);
+		va_end(ap);
+#ifdef TESTING
+		putchar('\n');
+#endif
+		return;
+	}
+
+	va_start(ap, fmt);
+	vsyslog(priority, fmt, ap);
+	va_end(ap);
+#ifdef TESTING
+	printf ("\n");
+#endif
+
+	return;
+}
+
+
+/*
+ *     Copy characters from ptr to line until a char in the delim
+ *     string is encountered or until min( space, len ) chars have
+ *     been copied.
+ *
+ *     Returns the actual number of chars copied.
+ */
+static int copyin( char *line,      int space,
+                   const char *ptr, int len,
+                   const char *delim )
+{
+    auto int i;
+    auto int count;
+
+    count = len < space ? len : space;
+
+    for(i=0; i<count && !strchr(delim, *ptr); i++ ) { *line++ = *ptr++; }
+
+    return( i );
+}
+
+/*
+ * Messages are separated by "\n".  Messages longer than
+ * LOG_LINE_LENGTH are broken up.
+ *
+ * Kernel symbols show up in the input buffer as : "[<aaaaaa>]",
+ * where "aaaaaa" is the address.  These are replaced with
+ * "[symbolname+offset/size]" in the output line - symbolname,
+ * offset, and size come from the kernel symbol table.
+ *
+ * If a kernel symbol happens to fall at the end of a message close
+ * in length to LOG_LINE_LENGTH, the symbol will not be expanded.
+ * (This should never happen, since the kernel should never generate
+ * messages that long.
+ *
+ * To preserve the original addresses, lines containing kernel symbols
+ * are output twice.  Once with the symbols converted and again with the
+ * original text.  Just in case somebody wants to run their own Oops
+ * analysis on the syslog, e.g. ksymoops.
+ */
+static void LogLine(char *ptr, int len)
+{
+    enum parse_state_enum {
+        PARSING_TEXT,
+        PARSING_SYMSTART,      /* at < */
+        PARSING_SYMBOL,        
+        PARSING_SYMEND         /* at ] */
+    };
+
+    static char line_buff[LOG_LINE_LENGTH];
+
+    static char *line                        =line_buff;
+    static enum parse_state_enum parse_state = PARSING_TEXT;
+    static int space                         = sizeof(line_buff)-1;
+
+    static char *sym_start;            /* points at the '<' of a symbol */
+
+    auto   int delta = 0;              /* number of chars copied        */
+    auto   int symbols_expanded = 0;   /* 1 if symbols were expanded */
+    auto   int skip_symbol_lookup = 0; /* skip symbol lookup on this pass */
+    auto   char *save_ptr = ptr;       /* save start of input line */
+    auto   int save_len = len;         /* save length at start of input line */
+
+    while( len > 0 )
+    {
+        if( space == 0 )    /* line buffer is full */
+        {
+            /*
+            ** Line too long.  Start a new line.
+            */
+            *line = 0;   /* force null terminator */
+
+	    if ( debugging )
+	    {
+		fputs("Line buffer full:\n", stderr);
+		fprintf(stderr, "\tLine: %s\n", line);
+	    }
+
+            Syslog( LOG_INFO, "%s", line_buff );
+            line  = line_buff;
+            space = sizeof(line_buff)-1;
+            parse_state = PARSING_TEXT;
+	    symbols_expanded = 0;
+	    skip_symbol_lookup = 0;
+	    save_ptr = ptr;
+	    save_len = len;
+        }
+
+        switch( parse_state )
+        {
+        case PARSING_TEXT:
+               delta = copyin( line, space, ptr, len, "\n[" );
+               line  += delta;
+               ptr   += delta;
+               space -= delta;
+               len   -= delta;
+
+               if( space == 0 || len == 0 )
+               {
+		  break;  /* full line_buff or end of input buffer */
+               }
+
+               if( *ptr == '\0' )  /* zero byte */
+               {
+                  ptr++;	/* skip zero byte */
+                  space -= 1;
+                  len   -= 1;
+
+		  break;
+	       }
+
+               if( *ptr == '\n' )  /* newline */
+               {
+                  ptr++;	/* skip newline */
+                  space -= 1;
+                  len   -= 1;
+
+                  *line = 0;  /* force null terminator */
+	          Syslog( LOG_INFO, "%s", line_buff );
+                  line  = line_buff;
+                  space = sizeof(line_buff)-1;
+		  if (symbols_twice) {
+		      if (symbols_expanded) {
+			  /* reprint this line without symbol lookup */
+			  symbols_expanded = 0;
+			  skip_symbol_lookup = 1;
+			  ptr = save_ptr;
+			  len = save_len;
+		      }
+		      else
+		      {
+			  skip_symbol_lookup = 0;
+			  save_ptr = ptr;
+			  save_len = len;
+		      }
+		  }
+                  break;
+               }
+               if( *ptr == '[' )   /* possible kernel symbol */
+               {
+                  *line++ = *ptr++;
+                  space -= 1;
+                  len   -= 1;
+	          if (!skip_symbol_lookup)
+                     parse_state = PARSING_SYMSTART;      /* at < */
+                  break;
+               }
+               /* Now that line_buff is no longer fed to *printf as format
+                * string, '%'s are no longer "dangerous".
+		*/
+               break;
+        
+        case PARSING_SYMSTART:
+               if( *ptr != '<' )
+               {
+                  parse_state = PARSING_TEXT;        /* not a symbol */
+                  break;
+               }
+
+               /*
+               ** Save this character for now.  If this turns out to
+               ** be a valid symbol, this char will be replaced later.
+               ** If not, we'll just leave it there.
+               */
+
+               sym_start = line; /* this will point at the '<' */
+
+               *line++ = *ptr++;
+               space -= 1;
+               len   -= 1;
+               parse_state = PARSING_SYMBOL;     /* symbol... */
+               break;
+
+        case PARSING_SYMBOL:
+               delta = copyin( line, space, ptr, len, ">\n[" );
+               line  += delta;
+               ptr   += delta;
+               space -= delta;
+               len   -= delta;
+               if( space == 0 || len == 0 )
+               {
+                  break;  /* full line_buff or end of input buffer */
+               }
+               if( *ptr != '>' )
+               {
+                  parse_state = PARSING_TEXT;
+                  break;
+               }
+
+               *line++ = *ptr++;  /* copy the '>' */
+               space -= 1;
+               len   -= 1;
+
+               parse_state = PARSING_SYMEND;
+
+               break;
+
+        case PARSING_SYMEND:
+               if( *ptr != ']' )
+               {
+                  parse_state = PARSING_TEXT;        /* not a symbol */
+                  break;
+               }
+
+               /*
+               ** It's really a symbol!  Replace address with the
+               ** symbol text.
+               */
+           {
+	       auto int sym_space;
+
+	       unsigned long value;
+	       auto struct symbol sym;
+	       auto char *symbol;
+
+               *(line-1) = 0;    /* null terminate the address string */
+               value  = strtoul(sym_start+1, (char **) 0, 16);
+               *(line-1) = '>';  /* put back delim */
+
+               if ( !symbol_lookup || (symbol = LookupSymbol(value, &sym)) == (char *)0 )
+               {
+                  parse_state = PARSING_TEXT;
+                  break;
+               }
+
+               /*
+               ** verify there is room in the line buffer
+               */
+               sym_space = space + ( line - sym_start );
+               if( sym_space < strlen(symbol) + 30 ) /*(30 should be overkill)*/
+               {
+                  parse_state = PARSING_TEXT;  /* not enough space */
+                  break;
+               }
+
+               delta = sprintf( sym_start, "%s+%d/%d]",
+                                symbol, sym.offset, sym.size );
+
+               space = sym_space + delta;
+               line  = sym_start + delta;
+	       symbols_expanded = 1;
+           }
+               ptr++;
+               len--;
+               parse_state = PARSING_TEXT;
+               break;
+
+        default: /* Can't get here! */
+               parse_state = PARSING_TEXT;
+
+        }
+    }
+
+    return;
+}
+
+
+static void LogKernelLine(void)
+
+{
+	auto int rdcnt;
+
+	/*
+	 * Zero-fill the log buffer.  This should cure a multitude of
+	 * problems with klogd logging the tail end of the message buffer
+	 * which will contain old messages.  Then read the kernel log
+	 * messages into this fresh buffer.
+	 */
+	memset(log_buffer, '\0', sizeof(log_buffer));
+	if ( (rdcnt = ksyslog(2, log_buffer, sizeof(log_buffer)-1)) < 0 )
+	{
+		if ( errno == EINTR )
+			return;
+		fprintf(stderr, "klogd: Error return from sys_sycall: " \
+			"%d - %s\n", errno, strerror(errno));
+	}
+	else
+		LogLine(log_buffer, rdcnt);
+	return;
+}
+
+
+static void LogProcLine(void)
+
+{
+	auto int rdcnt;
+
+	/*
+	 * Zero-fill the log buffer.  This should cure a multitude of
+	 * problems with klogd logging the tail end of the message buffer
+	 * which will contain old messages.  Then read the kernel messages
+	 * from the message pseudo-file into this fresh buffer.
+	 */
+	memset(log_buffer, '\0', sizeof(log_buffer));
+	if ( (rdcnt = read(kmsg, log_buffer, sizeof(log_buffer)-1)) < 0 )
+	{
+		if ( errno == EINTR )
+			return;
+		Syslog(LOG_ERR, "Cannot read proc file system: %d - %s.", \
+		       errno, strerror(errno));
+	}
+	else
+		LogLine(log_buffer, rdcnt);
+
+	return;
+}
+
+
+int main(argc, argv)
+
+	int argc;
+
+	char *argv[];
+
+{
+	auto int	ch,
+			use_output = 0;
+
+	auto char	*log_level = (char *) 0,
+			*output = (char *) 0;
+
+#ifndef TESTING
+	chdir ("/");
+#endif
+	/* Parse the command-line. */
+	while ((ch = getopt(argc, argv, "c:df:iIk:nopsvx2")) != EOF)
+		switch((char)ch)
+		{
+		    case '2':		/* Print lines with symbols twice. */
+			symbols_twice = 1;
+			break;
+		    case 'c':		/* Set console message level. */
+			log_level = optarg;
+			break;
+		    case 'd':		/* Activity debug mode. */
+			debugging = 1;
+			break;
+		    case 'f':		/* Define an output file. */
+			output = optarg;
+			use_output++;
+			break;
+		    case 'i':		/* Reload module symbols. */
+			SignalDaemon(SIGUSR1);
+			return(0);
+		    case 'I':
+			SignalDaemon(SIGUSR2);
+			return(0);
+		    case 'k':		/* Kernel symbol file. */
+			symfile = optarg;
+			break;
+		    case 'n':		/* don't fork */
+			no_fork++;
+			break;
+		    case 'o':		/* One-shot mode. */
+			one_shot = 1;
+			break;
+		    case 'p':
+			SetParanoiaLevel(1);	/* Load symbols on oops. */
+			break;	
+		    case 's':		/* Use syscall interface. */
+			use_syscall = 1;
+			break;
+		    case 'v':
+			printf("klogd %s.%s\n", VERSION, PATCHLEVEL);
+			exit (1);
+		    case 'x':
+			symbol_lookup = 0;
+			break;
+		}
+
+
+	/* Set console logging level. */
+	if ( log_level != (char *) 0 )
+	{
+		if ( (strlen(log_level) > 1) || \
+		     (strchr("12345678", *log_level) == (char *) 0) )
+		{
+			fprintf(stderr, "klogd: Invalid console logging "
+				"level <%s> specified.\n", log_level);
+			return(1);
+		}
+		console_log_level = *log_level - '0';
+	}		
+
+
+#ifndef TESTING
+	/*
+	 * The following code allows klogd to auto-background itself.
+	 * What happens is that the program forks and the parent quits.
+	 * The child closes all its open file descriptors, and issues a
+	 * call to setsid to establish itself as an independent session
+	 * immune from control signals.
+	 *
+	 * fork() is only called if it should run in daemon mode, fork is
+	 * not disabled with the command line argument and there's no
+	 * such process running.
+	 */
+	if ( (!one_shot) && (!no_fork) )
+	{
+		if (!check_pid(PidFile))
+		{
+			if ( fork() == 0 )
+			{
+				auto int fl;
+				int num_fds = getdtablesize();
+		
+				/* This is the child closing its file descriptors. */
+				for (fl= 0; fl <= num_fds; ++fl)
+				{
+					if ( fileno(stdout) == fl && use_output )
+						if ( strcmp(output, "-") == 0 )
+							continue;
+					close(fl);
+				}
+ 
+				setsid();
+			}
+			else
+				exit(0);
+		}
+		else
+		{
+			fputs("klogd: Already running.\n", stderr);
+			exit(1);
+		}
+	}
+
+
+	/* tuck my process id away */
+	if (!check_pid(PidFile))
+	{
+		if (!write_pid(PidFile))
+			Terminate();
+	}
+	else
+	{
+		fputs("klogd: Already running.\n", stderr);
+		Terminate();
+	}
+#endif	
+
+	/* Signal setups. */
+	for (ch= 1; ch < NSIG; ++ch)
+		signal(ch, SIG_IGN);
+	signal(SIGINT, stop_daemon);
+	signal(SIGKILL, stop_daemon);
+	signal(SIGTERM, stop_daemon);
+	signal(SIGHUP, stop_daemon);
+	signal(SIGTSTP, stop_logging);
+	signal(SIGCONT, restart);
+	signal(SIGUSR1, reload_daemon);
+	signal(SIGUSR2, reload_daemon);
+
+
+	/* Open outputs. */
+	if ( use_output )
+	{
+		if ( strcmp(output, "-") == 0 )
+			output_file = stdout;
+		else if ( (output_file = fopen(output, "w")) == (FILE *) 0 )
+		{
+			fprintf(stderr, "klogd: Cannot open output file " \
+				"%s - %s\n", output, strerror(errno));
+			return(1);
+		}
+	}
+	else
+		openlog("kernel", 0, LOG_KERN);
+
+
+	/* Handle one-shot logging. */
+	if ( one_shot )
+	{
+		if (symbol_lookup) {
+			symbol_lookup  = (InitKsyms(symfile) == 1);
+			symbol_lookup |= InitMsyms();
+			if (symbol_lookup == 0) {
+				Syslog(LOG_WARNING, "cannot find any symbols, turning off symbol lookups\n");
+			}
+		}
+		if ( (logsrc = GetKernelLogSrc()) == kernel )
+			LogKernelLine();
+		else
+			LogProcLine();
+		Terminate();
+	}
+
+	/* Determine where kernel logging information is to come from. */
+#if defined(KLOGD_DELAY)
+	sleep(KLOGD_DELAY);
+#endif
+	logsrc = GetKernelLogSrc();
+	if (symbol_lookup) {
+		symbol_lookup  = (InitKsyms(symfile) == 1);
+		symbol_lookup |= InitMsyms();
+		if (symbol_lookup == 0) {
+			Syslog(LOG_WARNING, "cannot find any symbols, turning off symbol lookups\n");
+		}
+	}
+
+        /* The main loop. */
+	while (1)
+	{
+		if ( change_state )
+			ChangeLogging();
+		switch ( logsrc )
+		{
+			case kernel:
+	  			LogKernelLine();
+				break;
+			case proc:
+				LogProcLine();
+				break;
+		        case none:
+				pause();
+				break;
+		}
+	}
+}
+/*
+ * Local variables:
+ *  c-indent-level: 8
+ *  c-basic-offset: 8
+ *  tab-width: 8
+ * End:
+ */