diff -urpN nmap-4.20-autoheader/MACLookup.cc nmap-4.20/MACLookup.cc

--- nmap-4.20-autoheader/MACLookup.cc	2006-11-06 02:14:45 +0000

+++ nmap-4.20/MACLookup.cc	2007-10-07 10:06:30 +0000

@@ -105,6 +105,7 @@

 #include "MACLookup.h"

 #include "nmap.h"

 #include "nmap_error.h"

+#include "droppriv.h"

 struct MAC_entry {

   int prefix; /* -1 means none set */

@@ -128,7 +129,7 @@ static inline int MACTableHash(int prefi

   return prefix % table_capacity;

 }

-static void mac_prefix_init() {

+void mac_prefix_init() {

   static int initialized = 0;

   if (initialized) return;

   initialized = 1;

diff -urpN nmap-4.20-autoheader/Makefile.in nmap-4.20/Makefile.in

--- nmap-4.20-autoheader/Makefile.in	2006-12-08 02:53:47 +0000

+++ nmap-4.20/Makefile.in	2007-10-07 09:34:54 +0000

@@ -48,11 +48,11 @@ TARGET = nmap

 TARGETNMAPFE=@TARGETNMAPFE@

 INSTALLNMAPFE=@INSTALLNMAPFE@

-export SRCS = main.cc nmap.cc targets.cc tcpip.cc nmap_error.cc utils.cc idle_scan.cc osscan.cc osscan2.cc output.cc scan_engine.cc timing.cc charpool.cc services.cc protocols.cc nmap_rpc.cc portlist.cc NmapOps.cc TargetGroup.cc Target.cc FingerPrintResults.cc service_scan.cc NmapOutputTable.cc MACLookup.cc nmap_tty.cc nmap_dns.cc @COMPAT_SRCS@

+export SRCS = main.cc nmap.cc targets.cc tcpip.cc nmap_error.cc utils.cc idle_scan.cc osscan.cc osscan2.cc output.cc scan_engine.cc timing.cc charpool.cc services.cc protocols.cc nmap_rpc.cc portlist.cc NmapOps.cc TargetGroup.cc Target.cc FingerPrintResults.cc service_scan.cc NmapOutputTable.cc MACLookup.cc nmap_tty.cc nmap_dns.cc droppriv.cc @COMPAT_SRCS@

-export HDRS = charpool.h FingerPrintResults.h global_structures.h idle_scan.h MACLookup.h nmap_amigaos.h nmap_dns.h nmap_error.h nmap.h NmapOps.h NmapOutputTable.h nmap_rpc.h nmap_tty.h nmap_winconfig.h osscan.h osscan2.h output.h portlist.h protocols.h scan_engine.h service_scan.h services.h TargetGroup.h Target.h targets.h tcpip.h timing.h utils.h

+export HDRS = charpool.h FingerPrintResults.h global_structures.h idle_scan.h MACLookup.h nmap_amigaos.h nmap_dns.h nmap_error.h nmap.h NmapOps.h NmapOutputTable.h nmap_rpc.h nmap_tty.h nmap_winconfig.h osscan.h osscan2.h output.h portlist.h protocols.h scan_engine.h service_scan.h services.h TargetGroup.h Target.h targets.h tcpip.h timing.h utils.h droppriv.h

-OBJS = main.o nmap.o targets.o tcpip.o nmap_error.o utils.o idle_scan.o osscan.o osscan2.o output.o scan_engine.o timing.o charpool.o services.o protocols.o nmap_rpc.o portlist.o NmapOps.o TargetGroup.o Target.o FingerPrintResults.o service_scan.o NmapOutputTable.o MACLookup.o nmap_tty.o nmap_dns.o @COMPAT_OBJS@

+OBJS = main.o nmap.o targets.o tcpip.o nmap_error.o utils.o idle_scan.o osscan.o osscan2.o output.o scan_engine.o timing.o charpool.o services.o protocols.o nmap_rpc.o portlist.o NmapOps.o TargetGroup.o Target.o FingerPrintResults.o service_scan.o NmapOutputTable.o MACLookup.o nmap_tty.o nmap_dns.o droppriv.o @COMPAT_OBJS@

 # %.o : %.cc -- nope this is a GNU extension

 .cc.o:

diff -urpN nmap-4.20-autoheader/configure.ac nmap-4.20/configure.ac

--- nmap-4.20-autoheader/configure.ac	2007-10-07 09:35:33 +0000

+++ nmap-4.20/configure.ac	2007-10-07 09:36:25 +0000

@@ -666,6 +666,49 @@ if test $ac_cv_ip_has_ip_sum = yes ; the

         AC_DEFINE(HAVE_IP_IP_SUM, 1, [Define to 1 for ip_sum member])

 fi

+try_drop_priv=no

+AC_CHECK_HEADERS(grp.h sys/capability.h sys/prctl.h)

+AC_CHECK_FUNC(chroot)

+AC_CHECK_FUNC(prctl,

+  [AC_CHECK_FUNC(setgid,

+    [AC_CHECK_FUNC(setgroups,

+      [AC_CHECK_FUNC(setreuid,

+        [try_drop_priv=yes

+	AC_CHECK_LIB(cap, cap_from_text, , [try_drop_priv=no])]

+      )]

+    )]

+  )]

+)

+

+AC_ARG_WITH(user,

+  [  --with-user=USERNAME    Lower root privileges by switching to user USERNAME])

+AC_MSG_CHECKING([whether to lower root privileges by default])

+if test -z "$with_user" -o "$try_drop_priv" = "no"; then

+       AC_MSG_RESULT(no)

+else

+       AC_DEFINE_UNQUOTED(NMAP_USER, "$withval", [Define user to switch during lowering privileges])

+       AC_MSG_RESULT(to \"$withval\")

+fi

+

+AC_ARG_WITH(chroot-empty,

+  [  --with-chroot-empty=DIRECTORY When lowering privileges and -n option is given, chroot to empty DIRECTORY])

+AC_MSG_CHECKING([whether to chroot when -n option is given])

+if test -z "$with_chroot_empty" -o "$try_drop_priv" = "no" -o "$ac_cv_func_chroot" = no; then

+       AC_MSG_RESULT(no)

+else

+       AC_DEFINE_UNQUOTED(NMAP_CHROOT_EMPTY, "$withval", [Define directory to chroot during lowering privileges if -n option is given])

+       AC_MSG_RESULT(to \"$withval\")

+fi

+

+AC_ARG_WITH(chroot-resolv,

+  [  --with-chroot-resolv=DIRECTORY When lowering privileges and -n option is not given, chroot to resolver DIRECTORY])

+AC_MSG_CHECKING([whether to chroot when -n option is not given])

+if test -z "$with_chroot_resolv" -o "$try_drop_priv" = "no" -o "$ac_cv_func_chroot" = no; then

+       AC_MSG_RESULT(no)

+else

+       AC_DEFINE_UNQUOTED(NMAP_CHROOT_RESOLV, "$withval", [Define directory to chroot during lowering privileges if -n option is not given])

+       AC_MSG_RESULT(to \"$withval\")

+fi

 dnl Checks for library functions.

 dnl AC_TYPE_SIGNAL

diff -urpN nmap-4.20-autoheader/droppriv.cc nmap-4.20/droppriv.cc

--- nmap-4.20-autoheader/droppriv.cc	1970-01-01 00:00:00 +0000

+++ nmap-4.20/droppriv.cc	2007-10-07 11:38:57 +0000

@@ -0,0 +1,93 @@

+#include "nmap.h"

+#include "droppriv.h"

+

+#ifndef NMAP_USER

+

+void drop_priv(void) {}

+

+#else

+

+#if HAVE_GRP_H

+# include <grp.h>

+#endif

+#if HAVE_SYS_CAPABILITY_H

+# include <sys/capability.h>

+#endif

+#if HAVE_SYS_PRCTL_H

+# include <sys/prctl.h>

+#endif

+

+#include "NmapOps.h"

+extern NmapOps o;		/* option structure */

+

+#ifndef NMAP_CHROOT_EMPTY

+# ifdef NMAP_CHROOT_RESOLV

+#  define NMAP_CHROOT_EMPTY NMAP_CHROOT_RESOLV

+# else

+#  define NMAP_CHROOT_EMPTY NULL

+# endif

+#endif

+

+#ifndef NMAP_CHROOT_RESOLV

+# define NMAP_CHROOT_RESOLV NULL

+#endif

+

+const char *

+drop_priv_dir(void)

+{

+	return o.noresolve ? NMAP_CHROOT_EMPTY : NMAP_CHROOT_RESOLV;

+}

+

+void

+drop_priv(void)

+{

+	const char *user = NMAP_USER;

+	const char *dir;

+	struct passwd *pw;

+	cap_t   caps;

+

+	if (geteuid())

+		return;

+

+	nmap_services_init();

+	nmap_protocols_init();

+	rpc_services_init();

+	AllProbes::service_scan_init();

+	routethrough_init();

+	mac_prefix_init();

+	if (!o.noresolve) etchosts_init();

+

+	if (setgroups(0, 0) < 0)

+		fatal("setgroups failed");

+

+	if (prctl(PR_SET_KEEPCAPS, 1))

+		fatal("prctl PR_SET_KEEPCAPS failed");

+

+	if (!(pw = getpwnam(user)))

+		fatal("lookup of user \"%s\" failed", user);

+	endpwent();

+

+	if (!pw->pw_uid)

+		fatal("user \"%s\" shouldn't be root", user);

+

+	dir = drop_priv_dir();

+	if (dir && (chroot(dir) || chdir("/")))

+		fatal("chroot to \"%s\" failed", dir);

+

+	if (setgid(pw->pw_gid) < 0)

+		fatal("setgid failed");

+

+	if (setreuid(pw->pw_uid, pw->pw_uid) < 0)

+		fatal("setreuid failed");

+

+	caps = cap_from_text("cap_net_raw=ep");

+	if (!caps)

+		fatal("cap_from_text failed");

+

+	if (cap_set_proc(caps) < 0)

+		fatal("cap_set_proc failed");

+

+	cap_free(caps);

+}

+

+#endif /* NMAP_USER */

diff -urpN nmap-4.20-autoheader/droppriv.h nmap-4.20/droppriv.h

--- nmap-4.20-autoheader/droppriv.h	1970-01-01 00:00:00 +0000

+++ nmap-4.20/droppriv.h	2007-10-07 11:39:28 +0000

@@ -0,0 +1,13 @@

+#ifndef NMAP_DROPPRIV_H__

+#define NMAP_DROPPRIV_H__

+

+extern const char *drop_priv_dir(void);

+extern void drop_priv(void);

+extern int nmap_services_init(void);

+extern int nmap_protocols_init(void);

+extern void rpc_services_init(void);

+extern void routethrough_init(void);

+extern void mac_prefix_init(void);

+extern void etchosts_init(void);

+

+#endif /* NMAP_DROPPRIV_H__ */

diff -urpN nmap-4.20-autoheader/nmap.cc nmap-4.20/nmap.cc

--- nmap-4.20-autoheader/nmap.cc	2006-10-14 06:03:54 +0000

+++ nmap-4.20/nmap.cc	2007-10-07 11:40:01 +0000

@@ -106,6 +106,7 @@

 #include "scan_engine.h"

 #include "idle_scan.h"

 #include "timing.h"

+#include "droppriv.h"

 #include "NmapOps.h"

 #include "MACLookup.h"

 #include "nmap_tty.h"

@@ -1098,9 +1099,10 @@ int nmap_main(int argc, char *argv[]) {

   if (pre_host_timeout != -1) o.host_timeout = pre_host_timeout;

-  if (o.osscan == OS_SCAN_SYS_1_ONLY)

+  if (o.osscan == OS_SCAN_SYS_1_ONLY ||

+      (o.osscan != OS_SCAN_SYS_2_ONLY && drop_priv_dir()))

     o.reference_FPs1 = parse_fingerprint_reference_file("nmap-os-fingerprints");

-  else if (o.osscan == OS_SCAN_DEFAULT || o.osscan == OS_SCAN_SYS_2_ONLY)

+  if (o.osscan == OS_SCAN_DEFAULT || o.osscan == OS_SCAN_SYS_2_ONLY)

     o.reference_FPs = parse_fingerprint_reference_file("nmap-os-db");

   o.ValidateOptions();

@@ -1217,6 +1219,8 @@ int nmap_main(int argc, char *argv[]) {

       o.sendpref = PACKET_SEND_ETH_STRONG;

   }

+  drop_priv();

+

   if (!ports) {

     if (o.ipprotscan) {

       ports = getdefaultprots();

diff -urpN nmap-4.20-autoheader/nmap_dns.cc nmap-4.20/nmap_dns.cc

--- nmap-4.20-autoheader/nmap_dns.cc	2006-09-02 20:33:57 +0000

+++ nmap-4.20/nmap_dns.cc	2007-10-07 10:09:02 +0000

@@ -160,6 +160,7 @@

 #include <vector>

 #include "nmap.h"

+#include "droppriv.h"

 #include "NmapOps.h"

 #include "nmap_dns.h"

 #include "nsock.h"

@@ -1016,7 +1017,7 @@ static char *lookup_etchosts(u32 ip) {

 }

-static void etchosts_init(void) {

+void etchosts_init(void) {

   static int initialized = 0;

   if (initialized) return;

   initialized = 1;

diff -urpN nmap-4.20-autoheader/nmap_rpc.cc nmap-4.20/nmap_rpc.cc

--- nmap-4.20-autoheader/nmap_rpc.cc	2006-08-25 01:47:59 +0000

+++ nmap-4.20/nmap_rpc.cc	2007-10-07 09:36:25 +0000

@@ -103,6 +103,7 @@

 #include "nmap_rpc.h"

+#include "droppriv.h"

 #include "NmapOps.h"

 extern NmapOps o;

@@ -117,7 +118,7 @@ static unsigned long rpc_xid_base = (uns

 static size_t tcp_readlen=0; /* used in get_rpc_results but can be reset in 

 			    send_rpc_query */

-static void rpc_services_init() {

+void rpc_services_init() {

   static int services_initialized = 0;

   if (services_initialized) return;

   services_initialized = 1;

diff -urpN nmap-4.20-autoheader/protocols.cc nmap-4.20/protocols.cc

--- nmap-4.20-autoheader/protocols.cc	2006-09-05 08:39:45 +0000

+++ nmap-4.20/protocols.cc	2007-10-07 09:36:25 +0000

@@ -100,13 +100,14 @@

 /* $Id: protocols.cc 3943 2006-09-05 08:39:32Z fyodor $ */

 #include "protocols.h"

+#include "droppriv.h"

 #include "NmapOps.h"

 extern NmapOps o;

 static int numipprots = 0;

 static struct protocol_list *protocol_table[PROTOCOL_TABLE_SIZE];

-static int nmap_protocols_init() {

+int nmap_protocols_init() {

   static int protocols_initialized = 0;

   if (protocols_initialized) return 0;

diff -urpN nmap-4.20-autoheader/services.cc nmap-4.20/services.cc

--- nmap-4.20-autoheader/services.cc	2006-08-25 01:47:59 +0000

+++ nmap-4.20/services.cc	2007-10-07 09:36:25 +0000

@@ -100,6 +100,7 @@

 /* $Id: services.cc 3869 2006-08-25 01:47:49Z fyodor $ */

 #include "services.h"

+#include "droppriv.h"

 #include "NmapOps.h"

 extern NmapOps o;

@@ -107,7 +108,7 @@ static int numtcpports = 0;

 static int numudpports = 0;

 static struct service_list *service_table[SERVICE_TABLE_SIZE];

-static int nmap_services_init() {

+int nmap_services_init() {

   static int services_initialized = 0;

   if (services_initialized) return 0;

diff -urpN nmap-4.20-autoheader/tcpip.cc nmap-4.20/tcpip.cc

--- nmap-4.20-autoheader/tcpip.cc	2006-12-08 03:01:19 +0000

+++ nmap-4.20/tcpip.cc	2007-10-07 10:02:41 +0000

@@ -104,6 +104,7 @@

 #endif

 #include <dnet.h>

 #include "tcpip.h"

+#include "droppriv.h"

 #include "NmapOps.h"

 #if HAVE_SYS_TIME_H

@@ -2410,6 +2411,14 @@ void set_pcap_filter(const char *device,

   pcap_freecode(&fcode);

 }

+static FILE *routefp;

+

+void routethrough_init(void)

+{

+  if (!routefp)

+     routefp = fopen("/proc/net/route", "r");

+}

+

 /* The 'dev' passed in must be at least 32 bytes long */

 int ipaddr2devname( char *dev, const struct in_addr *addr ) {

 struct interface_info *mydevs;

@@ -2788,7 +2797,6 @@ struct sys_route *getsysroutes(int *howm

   int route_capacity = 128;

   static struct sys_route *routes = NULL;

   static int numroutes = 0;

-  FILE *routefp;

   char buf[1024];

   char iface[16];

   char *p, *endptr;

@@ -2805,7 +2813,7 @@ struct sys_route *getsysroutes(int *howm

     routes = (struct sys_route *) safe_zalloc(route_capacity * sizeof(struct sys_route));

     ifaces = getinterfaces(&numifaces);

     /* First let us try Linux-style /proc/net/route */

-    routefp = fopen("/proc/net/route", "r");

+    routethrough_init();

     if (routefp) {

       (void) fgets(buf, sizeof(buf), routefp); /* Kill the first line (column headers) */

       while(fgets(buf,sizeof(buf), routefp)) {

@@ -2888,6 +2896,8 @@ struct sys_route *getsysroutes(int *howm

 	  routes = (struct sys_route *) realloc(routes, route_capacity * sizeof(struct sys_route));

 	}

       }

+      fclose(routefp);

+      routefp = NULL;

     } else {

       struct dnet_collector_route_nfo dcrn;

       dcrn.routes = routes;