From: hannes <hannes>
Date: Thu, 22 Jan 2004 09:51:30 +0000 (+0000)
Subject: from Pekka Savola <pekkas@netcore.fi>:
X-Git-Tag: tcpdump-3.9.1~490
X-Git-Url: https://git.tcpdump.org/tcpdump/commitdiff_plain/ad714140165cb600447506c561c2ee493deaa9b1?hp=b6c8d27c478febe5b96a55c2c99d7cd0e7f34baf

from Pekka Savola <pekkas@netcore.fi>:
 add a compile time option --with-user=USERNAME that
 drops privileges by default to USERNAME
---

diff --git a/acconfig.h b/acconfig.h
index 09e83515..5a2b508b 100644
--- a/acconfig.h
+++ b/acconfig.h
@@ -126,3 +126,6 @@
 
 /* Define if you have a dnet_htoa declaration in <netdnet/dnetdb.h>.  */
 #undef HAVE_NETDNET_DNETDB_H_DNET_HTOA
+
+/* define if should drop privileges by default */
+#undef WITH_USER
diff --git a/configure.in b/configure.in
index 55977c40..d39f370d 100644
--- a/configure.in
+++ b/configure.in
@@ -1,4 +1,4 @@
-dnl @(#) $Header: /tcpdump/master/tcpdump/configure.in,v 1.173 2004-01-15 19:53:48 guy Exp $ (LBL)
+dnl @(#) $Header: /tcpdump/master/tcpdump/configure.in,v 1.174 2004-01-22 09:51:31 hannes Exp $ (LBL)
 dnl
 dnl Copyright (c) 1994, 1995, 1996, 1997
 dnl	The Regents of the University of California.  All rights reserved.
@@ -6,7 +6,7 @@ dnl
 dnl Process this file with autoconf to produce a configure script.
 dnl
 
-AC_REVISION($Revision: 1.173 $)
+AC_REVISION($Revision: 1.174 $)
 AC_PREREQ(2.50)
 AC_INIT(tcpdump.c)
 
@@ -102,6 +102,15 @@ yes)	AC_MSG_RESULT(yes)
 	;;
 esac
 
+AC_ARG_WITH(user, [  --with-user=USERNAME    drop privileges by default to USERNAME])
+AC_MSG_CHECKING([whether to drop root privileges by default])
+if test ! -z "$with_user" ; then
+        AC_DEFINE_UNQUOTED(WITH_USER, "$withval")
+       AC_MSG_RESULT(to \"$withval\")
+else
+       AC_MSG_RESULT(no)
+fi
+
 AC_MSG_CHECKING([whether to enable ipv6])
 AC_ARG_ENABLE(ipv6,
 [  --enable-ipv6           enable ipv6 (with ipv4) support
diff --git a/tcpdump.1 b/tcpdump.1
index 045415a3..eaa2ad3d 100644
--- a/tcpdump.1
+++ b/tcpdump.1
@@ -1,4 +1,4 @@
-.\" @(#) $Header: /tcpdump/master/tcpdump/Attic/tcpdump.1,v 1.158 2004-01-22 09:35:50 hannes Exp $ (LBL)
+.\" @(#) $Header: /tcpdump/master/tcpdump/Attic/tcpdump.1,v 1.159 2004-01-22 09:51:31 hannes Exp $ (LBL)
 .\"
 .\"	$NetBSD: tcpdump.8,v 1.9 2003/03/31 00:18:17 perry Exp $
 .\"
@@ -551,6 +551,8 @@ Drops privileges (if root) and changes user ID to
 .I user
 and the group ID to the primary group of
 .IR user .
+.IP
+This behavior can also be enabled by default at compile time.
 .IP "\fI expression\fP"
 .RS
 selects which packets will be dumped.
diff --git a/tcpdump.c b/tcpdump.c
index a3fce525..4fec886c 100644
--- a/tcpdump.c
+++ b/tcpdump.c
@@ -30,7 +30,7 @@ static const char copyright[] _U_ =
     "@(#) Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 2000\n\
 The Regents of the University of California.  All rights reserved.\n";
 static const char rcsid[] _U_ =
-    "@(#) $Header: /tcpdump/master/tcpdump/tcpdump.c,v 1.226 2004-01-22 09:35:50 hannes Exp $ (LBL)";
+    "@(#) $Header: /tcpdump/master/tcpdump/tcpdump.c,v 1.227 2004-01-22 09:51:31 hannes Exp $ (LBL)";
 #endif
 
 /*
@@ -898,6 +898,16 @@ main(int argc, char **argv)
 		(void)fprintf(stderr, "%s: pcap_loop: %s\n",
 		    program_name, pcap_geterr(pd));
 	}
+#ifdef WITH_USER
+	/* if run as root, drop root; protect against remote sec problems */
+	if (getuid() == 0 || geteuid() == 0) {
+		/* Run with '-Z root' to restore old behaviour */ 
+		if (!username) {
+			droproot(WITH_USER);
+			/* does not return if fails */
+		}
+	}
+#endif
 	if (RFileName == NULL) {
 		/*
 		 * We're doing a live capture.  Report the capture