diff -ur sysklogd-1.4.1.orig/klogd.8 sysklogd-1.4.1/klogd.8

--- sysklogd-1.4.1.orig/klogd.8	Sun Mar 11 22:35:51 2001

+++ sysklogd-1.4.1/klogd.8	Mon Oct  8 09:50:50 2001

@@ -3,8 +3,9 @@

 .\" Sun Jul 30 01:35:55 MET: Martin Schulze: Updates

 .\" Sun Nov 19 23:22:21 MET: Martin Schulze: Updates

 .\" Mon Aug 19 09:42:08 CDT 1996: Dr. G.W. Wettstein: Updates

+.\" Thu Feb 17 2000: Chris Wing: Unprivileged klogd feature

 .\"

-.TH KLOGD 8 "21 August, 1999" "Version 1.4" "Linux System Administration"

+.TH KLOGD 8 "8 October, 2001" "Version 1.4.1+CAEN/OW/ALT" "Linux System Administration"

 .SH NAME

 klogd \- Kernel Log Daemon

 .LP

@@ -17,6 +18,12 @@

 .RB [ " \-f "

 .I fname

 ]

+.RB [ " \-u "

+.I username

+]

+.RB [ " \-j "

+.I chroot_dir

+]

 .RB [ " \-iI " ]

 .RB [ " \-n " ]

 .RB [ " \-o " ]

@@ -45,6 +52,20 @@

 .TP

 .BI "\-f " file

 Log messages to the specified filename rather than to the syslog facility.

+.TP

+.BI "\-u " username

+Tells klogd to become the specified user and drop root privileges before

+starting logging.

+.TP

+.BI "\-j " chroot_dir

+Tells klogd to

+.BR chroot (2)

+into this directory after initializing.

+This option is only valid if the \-u option is also used to run klogd

+without root privileges.

+Note that the use of this option will prevent \-i and \-I from working

+unless you set up the chroot directory in such a way that klogd can still

+read the kernel module symbols.

 .TP

 .BI "\-i \-I"

 Signal the currently executing klogd daemon.  Both of these switches control

diff -ur sysklogd-1.4.1.orig/klogd.c sysklogd-1.4.1/klogd.c

--- sysklogd-1.4.1.orig/klogd.c	Sun Mar 11 22:40:10 2001

+++ sysklogd-1.4.1/klogd.c	Mon Oct  8 09:52:06 2001

@@ -258,6 +258,8 @@

 #include <stdarg.h>

 #include <paths.h>

 #include <stdlib.h>

+#include <pwd.h>

+#include <grp.h>

 #include "klogd.h"

 #include "ksyms.h"

 #ifndef TESTING

@@ -308,6 +310,9 @@

 int debugging = 0;

 int symbols_twice = 0;

+char *server_user = NULL;

+char *chroot_dir = NULL;

+int log_flags = 0;

 /* Function prototypes. */

 extern int ksyslog(int type, char *buf, int len);

@@ -528,8 +533,9 @@

 	 * 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)) )

+	if (!server_user &&

+	    (use_syscall ||

+	    ((stat(_PATH_KLOG, &sb) < 0) && (errno == ENOENT))))

 	{

 	  	/* Initialize kernel logging. */

 	  	ksyslog(1, NULL, 0);

@@ -977,6 +983,27 @@

 }

+static int drop_root(void)

+{

+	struct passwd *pw;

+

+	if (!(pw = getpwnam(server_user))) return -1;

+

+	if (!pw->pw_uid) return -1;

+

+	if (chroot_dir) {

+		if (chroot(chroot_dir)) return -1;

+		if (chdir("/")) return -1;

+	}

+

+	if (setgroups(0, NULL)) return -1;

+	if (setgid(pw->pw_gid)) return -1;

+	if (setuid(pw->pw_uid)) return -1;

+

+	return 0;

+}

+

+

 int main(argc, argv)

 	int argc;

@@ -994,7 +1021,7 @@

 	chdir ("/");

 #endif

 	/* Parse the command-line. */

-	while ((ch = getopt(argc, argv, "c:df:iIk:nopsvx2")) != EOF)

+	while ((ch = getopt(argc, argv, "c:df:u:j:iIk:nopsvx2")) != EOF)

 		switch((char)ch)

 		{

 		    case '2':		/* Print lines with symbols twice. */

@@ -1016,6 +1043,10 @@

 		    case 'I':

 			SignalDaemon(SIGUSR2);

 			return(0);

+		    case 'j':		/* chroot 'j'ail */

+			chroot_dir = optarg;

+			log_flags |= LOG_NDELAY;

+			break;

 		    case 'k':		/* Kernel symbol file. */

 			symfile = optarg;

 			break;

@@ -1031,6 +1062,9 @@

 		    case 's':		/* Use syscall interface. */

 			use_syscall = 1;

 			break;

+		    case 'u':		/* Run as this user */

+			server_user = optarg;

+			break;

 		    case 'v':

 			printf("klogd %s.%s\n", VERSION, PATCHLEVEL);

 			exit (1);

@@ -1039,6 +1073,10 @@

 			break;

 		}

+	if (chroot_dir && !server_user) {

+		fputs("'-j' is only valid with '-u'", stderr);

+		exit(1);

+	}

 	/* Set console logging level. */

 	if ( log_level != (char *) 0 )

@@ -1136,7 +1174,7 @@

 		}

 	}

 	else

-		openlog("kernel", 0, LOG_KERN);

+		openlog("kernel", log_flags, LOG_KERN);

 	/* Handle one-shot logging. */

@@ -1161,4 +1199,9 @@

 		}

 	}

+

+	if (server_user && drop_root()) {

+		syslog(LOG_ALERT, "klogd: failed to drop root");

+		Terminate();

+	}

         /* The main loop. */