|
|
324fcf |
diff --git a/client/Makefile.am b/client/Makefile.am
|
|
|
324fcf |
index b1ecf82..387c097 100644
|
|
|
324fcf |
--- a/client/Makefile.am
|
|
|
324fcf |
+++ b/client/Makefile.am
|
|
|
324fcf |
@@ -15,6 +15,7 @@ dhclient_SOURCES = clparse.c dhclient.c dhc6.c \
|
|
|
324fcf |
scripts/bsdos scripts/freebsd scripts/linux scripts/macos \
|
|
|
324fcf |
scripts/netbsd scripts/nextstep scripts/openbsd \
|
|
|
324fcf |
scripts/solaris scripts/openwrt
|
|
|
324fcf |
-dhclient_LDADD = ../common/libdhcp.a ../omapip/libomapi.la $(BIND_LIBS)
|
|
|
324fcf |
+dhclient_LDADD = ../common/libdhcp.a ../omapip/libomapi.la \
|
|
|
324fcf |
+ $(CAPNG_LDADD) $(BIND_LIBS)
|
|
|
324fcf |
man_MANS = dhclient.8 dhclient-script.8 dhclient.conf.5 dhclient.leases.5
|
|
|
324fcf |
EXTRA_DIST = $(man_MANS)
|
|
|
324fcf |
diff --git a/client/dhclient-script.8 b/client/dhclient-script.8
|
|
|
324fcf |
index 3a3aaf7..fec726c 100644
|
|
|
324fcf |
--- a/client/dhclient-script.8
|
|
|
324fcf |
+++ b/client/dhclient-script.8
|
|
|
324fcf |
@@ -245,6 +245,16 @@ repeatedly initialized to the values provided by one server, and then
|
|
|
324fcf |
the other. Assuming the information provided by both servers is
|
|
|
324fcf |
valid, this shouldn't cause any real problems, but it could be
|
|
|
324fcf |
confusing.
|
|
|
324fcf |
+.PP
|
|
|
324fcf |
+Normally, if dhclient was compiled with libcap-ng support,
|
|
|
324fcf |
+dhclient drops most capabilities immediately upon startup.
|
|
|
324fcf |
+While more secure, this greatly restricts the additional actions that
|
|
|
324fcf |
+hooks in dhclient-script can take. For example, any daemons that
|
|
|
324fcf |
+dhclient-script starts or restarts will inherit the restricted
|
|
|
324fcf |
+capabilities as well, which may interfere with their correct operation.
|
|
|
324fcf |
+Thus, the
|
|
|
324fcf |
+.BI \-nc
|
|
|
324fcf |
+option can be used to prevent dhclient from dropping capabilities.
|
|
|
324fcf |
.SH SEE ALSO
|
|
|
324fcf |
dhclient(8), dhcpd(8), dhcrelay(8), dhclient.conf(5) and
|
|
|
324fcf |
dhclient.leases(5).
|
|
|
324fcf |
diff --git a/client/dhclient.8 b/client/dhclient.8
|
|
|
324fcf |
index aa2238d..005cda5 100644
|
|
|
324fcf |
--- a/client/dhclient.8
|
|
|
324fcf |
+++ b/client/dhclient.8
|
|
|
324fcf |
@@ -134,6 +134,9 @@ dhclient - Dynamic Host Configuration Protocol Client
|
|
|
324fcf |
.B -w
|
|
|
324fcf |
]
|
|
|
324fcf |
[
|
|
|
324fcf |
+.B -nc
|
|
|
324fcf |
+]
|
|
|
324fcf |
+[
|
|
|
324fcf |
.B -B
|
|
|
324fcf |
]
|
|
|
324fcf |
[
|
|
|
324fcf |
@@ -320,6 +323,32 @@ not to exit when it doesn't find any such interfaces. The
|
|
|
324fcf |
program can then be used to notify the client when a network interface
|
|
|
324fcf |
has been added or removed, so that the client can attempt to configure an IP
|
|
|
324fcf |
address on that interface.
|
|
|
324fcf |
+.TP
|
|
|
324fcf |
+.BI \-nc
|
|
|
324fcf |
+Do not drop capabilities.
|
|
|
324fcf |
+
|
|
|
324fcf |
+Normally, if
|
|
|
324fcf |
+.B dhclient
|
|
|
324fcf |
+was compiled with libcap-ng support,
|
|
|
324fcf |
+.B dhclient
|
|
|
324fcf |
+drops most capabilities immediately upon startup. While more secure,
|
|
|
324fcf |
+this greatly restricts the additional actions that hooks in
|
|
|
324fcf |
+.B dhclient-script (8)
|
|
|
324fcf |
+can take. (For example, any daemons that
|
|
|
324fcf |
+.B dhclient-script (8)
|
|
|
324fcf |
+starts or restarts will inherit the restricted capabilities as well,
|
|
|
324fcf |
+which may interfere with their correct operation.) Thus, the
|
|
|
324fcf |
+.BI \-nc
|
|
|
324fcf |
+option can be used to prevent
|
|
|
324fcf |
+.B dhclient
|
|
|
324fcf |
+from dropping capabilities.
|
|
|
324fcf |
+
|
|
|
324fcf |
+The
|
|
|
324fcf |
+.BI \-nc
|
|
|
324fcf |
+option is ignored if
|
|
|
324fcf |
+.B dhclient
|
|
|
324fcf |
+was not compiled with libcap-ng support.
|
|
|
324fcf |
+
|
|
|
324fcf |
.TP
|
|
|
324fcf |
.BI \-n
|
|
|
324fcf |
Do not configure any interfaces. This is most likely to be useful in
|
|
|
324fcf |
diff --git a/client/dhclient.c b/client/dhclient.c
|
|
|
324fcf |
index 09ae09b..2d564ff 100644
|
|
|
324fcf |
--- a/client/dhclient.c
|
|
|
324fcf |
+++ b/client/dhclient.c
|
|
|
324fcf |
@@ -40,6 +40,10 @@
|
|
|
324fcf |
#include <isc/file.h>
|
|
|
324fcf |
#include <dns/result.h>
|
|
|
324fcf |
|
|
|
324fcf |
+#ifdef HAVE_LIBCAP_NG
|
|
|
324fcf |
+#include <cap-ng.h>
|
|
|
324fcf |
+#endif
|
|
|
324fcf |
+
|
|
|
324fcf |
/*
|
|
|
324fcf |
* Defined in stdio.h when _GNU_SOURCE is set, but we don't want to define
|
|
|
324fcf |
* that when building ISC code.
|
|
|
324fcf |
@@ -239,6 +243,9 @@ main(int argc, char **argv) {
|
|
|
324fcf |
int timeout_arg = 0;
|
|
|
324fcf |
char *arg_conf = NULL;
|
|
|
324fcf |
int arg_conf_len = 0;
|
|
|
324fcf |
+#ifdef HAVE_LIBCAP_NG
|
|
|
324fcf |
+ int keep_capabilities = 0;
|
|
|
324fcf |
+#endif
|
|
|
324fcf |
|
|
|
324fcf |
/* Initialize client globals. */
|
|
|
324fcf |
memset(&default_duid, 0, sizeof(default_duid));
|
|
|
324fcf |
@@ -548,6 +555,10 @@ main(int argc, char **argv) {
|
|
|
324fcf |
}
|
|
|
324fcf |
|
|
|
324fcf |
dhclient_request_options = argv[i];
|
|
|
324fcf |
+ } else if (!strcmp(argv[i], "-nc")) {
|
|
|
324fcf |
+#ifdef HAVE_LIBCAP_NG
|
|
|
324fcf |
+ keep_capabilities = 1;
|
|
|
324fcf |
+#endif
|
|
|
324fcf |
} else if (argv[i][0] == '-') {
|
|
|
324fcf |
usage("Unknown command: %s", argv[i]);
|
|
|
324fcf |
} else if (interfaces_requested < 0) {
|
|
|
324fcf |
@@ -608,6 +619,19 @@ main(int argc, char **argv) {
|
|
|
324fcf |
path_dhclient_script = s;
|
|
|
324fcf |
}
|
|
|
324fcf |
|
|
|
324fcf |
+#ifdef HAVE_LIBCAP_NG
|
|
|
324fcf |
+ /* Drop capabilities */
|
|
|
324fcf |
+ if (!keep_capabilities) {
|
|
|
324fcf |
+ capng_clear(CAPNG_SELECT_CAPS);
|
|
|
324fcf |
+ capng_update(CAPNG_ADD, CAPNG_EFFECTIVE|CAPNG_PERMITTED,
|
|
|
324fcf |
+ CAP_DAC_OVERRIDE); // Drop this someday
|
|
|
324fcf |
+ capng_updatev(CAPNG_ADD, CAPNG_EFFECTIVE|CAPNG_PERMITTED,
|
|
|
324fcf |
+ CAP_NET_ADMIN, CAP_NET_RAW,
|
|
|
324fcf |
+ CAP_NET_BIND_SERVICE, CAP_SYS_ADMIN, -1);
|
|
|
324fcf |
+ capng_apply(CAPNG_SELECT_CAPS);
|
|
|
324fcf |
+ }
|
|
|
324fcf |
+#endif
|
|
|
324fcf |
+
|
|
|
324fcf |
/* Set up the initial dhcp option universe. */
|
|
|
324fcf |
initialize_common_option_spaces();
|
|
|
324fcf |
|
|
|
324fcf |
diff --git a/configure.ac b/configure.ac
|
|
|
324fcf |
index adc98a8..8bbe5ca 100644
|
|
|
324fcf |
--- a/configure.ac
|
|
|
324fcf |
+++ b/configure.ac
|
|
|
324fcf |
@@ -592,6 +592,41 @@ AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[]], [[void foo() __attribute__((noreturn));
|
|
|
324fcf |
# Look for optional headers.
|
|
|
324fcf |
AC_CHECK_HEADERS(sys/socket.h net/if_dl.h net/if6.h regex.h)
|
|
|
324fcf |
|
|
|
324fcf |
+# look for capabilities library
|
|
|
324fcf |
+AC_ARG_WITH(libcap-ng,
|
|
|
324fcf |
+ [ --with-libcap-ng=[auto/yes/no] Add Libcap-ng support [default=auto]],,
|
|
|
324fcf |
+ with_libcap_ng=auto)
|
|
|
324fcf |
+
|
|
|
324fcf |
+# Check for Libcap-ng API
|
|
|
324fcf |
+#
|
|
|
324fcf |
+# libcap-ng detection
|
|
|
324fcf |
+if test x$with_libcap_ng = xno ; then
|
|
|
324fcf |
+ have_libcap_ng=no;
|
|
|
324fcf |
+else
|
|
|
324fcf |
+ # Start by checking for header file
|
|
|
324fcf |
+ AC_CHECK_HEADER(cap-ng.h, capng_headers=yes, capng_headers=no)
|
|
|
324fcf |
+
|
|
|
324fcf |
+ # See if we have libcap-ng library
|
|
|
324fcf |
+ AC_CHECK_LIB(cap-ng, capng_clear,
|
|
|
324fcf |
+ CAPNG_LDADD=-lcap-ng,)
|
|
|
324fcf |
+
|
|
|
324fcf |
+ # Check results are usable
|
|
|
324fcf |
+ if test x$with_libcap_ng = xyes -a x$CAPNG_LDADD = x ; then
|
|
|
324fcf |
+ AC_MSG_ERROR(libcap-ng support was requested and the library was not found)
|
|
|
324fcf |
+ fi
|
|
|
324fcf |
+ if test x$CAPNG_LDADD != x -a $capng_headers = no ; then
|
|
|
324fcf |
+ AC_MSG_ERROR(libcap-ng libraries found but headers are missing)
|
|
|
324fcf |
+ fi
|
|
|
324fcf |
+fi
|
|
|
324fcf |
+AC_SUBST(CAPNG_LDADD)
|
|
|
324fcf |
+AC_MSG_CHECKING(whether to use libcap-ng)
|
|
|
324fcf |
+if test x$CAPNG_LDADD != x ; then
|
|
|
324fcf |
+ AC_DEFINE(HAVE_LIBCAP_NG,1,[libcap-ng support])
|
|
|
324fcf |
+ AC_MSG_RESULT(yes)
|
|
|
324fcf |
+else
|
|
|
324fcf |
+ AC_MSG_RESULT(no)
|
|
|
324fcf |
+fi
|
|
|
324fcf |
+
|
|
|
324fcf |
# Solaris needs some libraries for functions
|
|
|
324fcf |
AC_SEARCH_LIBS(socket, [socket])
|
|
|
324fcf |
AC_SEARCH_LIBS(inet_ntoa, [nsl])
|
|
|
324fcf |
diff --git a/relay/Makefile.am b/relay/Makefile.am
|
|
|
324fcf |
index 316a524..999e543 100644
|
|
|
324fcf |
--- a/relay/Makefile.am
|
|
|
324fcf |
+++ b/relay/Makefile.am
|
|
|
324fcf |
@@ -5,7 +5,7 @@ AM_CPPFLAGS = -DLOCALSTATEDIR='"@localstatedir@"'
|
|
|
324fcf |
sbin_PROGRAMS = dhcrelay
|
|
|
324fcf |
dhcrelay_SOURCES = dhcrelay.c
|
|
|
324fcf |
dhcrelay_LDADD = ../common/libdhcp.a ../omapip/libomapi.la \
|
|
|
324fcf |
- $(BIND_LIBS)
|
|
|
324fcf |
+ $(CAPNG_LDADD) $(BIND_LIBS)
|
|
|
324fcf |
man_MANS = dhcrelay.8
|
|
|
324fcf |
EXTRA_DIST = $(man_MANS)
|
|
|
324fcf |
|
|
|
324fcf |
diff --git a/relay/dhcrelay.c b/relay/dhcrelay.c
|
|
|
324fcf |
index eac119c..d2ab448 100644
|
|
|
324fcf |
--- a/relay/dhcrelay.c
|
|
|
324fcf |
+++ b/relay/dhcrelay.c
|
|
|
324fcf |
@@ -32,6 +32,11 @@
|
|
|
324fcf |
#include <sys/time.h>
|
|
|
324fcf |
#include <isc/file.h>
|
|
|
324fcf |
|
|
|
324fcf |
+#ifdef HAVE_LIBCAP_NG
|
|
|
324fcf |
+# include <cap-ng.h>
|
|
|
324fcf |
+ int keep_capabilities = 0;
|
|
|
324fcf |
+#endif
|
|
|
324fcf |
+
|
|
|
324fcf |
TIME default_lease_time = 43200; /* 12 hours... */
|
|
|
324fcf |
TIME max_lease_time = 86400; /* 24 hours... */
|
|
|
324fcf |
struct tree_cache *global_options[256];
|
|
|
324fcf |
@@ -472,6 +477,10 @@ main(int argc, char **argv) {
|
|
|
324fcf |
if (++i == argc)
|
|
|
324fcf |
usage(use_noarg, argv[i-1]);
|
|
|
324fcf |
dhcrelay_sub_id = argv[i];
|
|
|
324fcf |
+#endif
|
|
|
324fcf |
+ } else if (!strcmp(argv[i], "-nc")) {
|
|
|
324fcf |
+#ifdef HAVE_LIBCAP_NG
|
|
|
324fcf |
+ keep_capabilities = 1;
|
|
|
324fcf |
#endif
|
|
|
324fcf |
} else if (!strcmp(argv[i], "-pf")) {
|
|
|
324fcf |
if (++i == argc)
|
|
|
324fcf |
@@ -547,6 +556,17 @@ main(int argc, char **argv) {
|
|
|
324fcf |
#endif
|
|
|
324fcf |
}
|
|
|
324fcf |
|
|
|
324fcf |
+#ifdef HAVE_LIBCAP_NG
|
|
|
324fcf |
+ /* Drop capabilities */
|
|
|
324fcf |
+ if (!keep_capabilities) {
|
|
|
324fcf |
+ capng_clear(CAPNG_SELECT_BOTH);
|
|
|
324fcf |
+ capng_updatev(CAPNG_ADD, CAPNG_EFFECTIVE|CAPNG_PERMITTED,
|
|
|
324fcf |
+ CAP_NET_RAW, CAP_NET_BIND_SERVICE, -1);
|
|
|
324fcf |
+ capng_apply(CAPNG_SELECT_BOTH);
|
|
|
324fcf |
+ log_info ("Dropped all unnecessary capabilities.");
|
|
|
324fcf |
+ }
|
|
|
324fcf |
+#endif
|
|
|
324fcf |
+
|
|
|
324fcf |
if (!quiet) {
|
|
|
324fcf |
log_info("%s %s", message, PACKAGE_VERSION);
|
|
|
324fcf |
log_info(copyright);
|
|
|
324fcf |
@@ -699,6 +719,15 @@ main(int argc, char **argv) {
|
|
|
324fcf |
signal(SIGTERM, dhcp_signal_handler); /* kill */
|
|
|
324fcf |
#endif
|
|
|
324fcf |
|
|
|
324fcf |
+#ifdef HAVE_LIBCAP_NG
|
|
|
324fcf |
+ /* Drop all capabilities */
|
|
|
324fcf |
+ if (!keep_capabilities) {
|
|
|
324fcf |
+ capng_clear(CAPNG_SELECT_BOTH);
|
|
|
324fcf |
+ capng_apply(CAPNG_SELECT_BOTH);
|
|
|
324fcf |
+ log_info ("Dropped all capabilities.");
|
|
|
324fcf |
+ }
|
|
|
324fcf |
+#endif
|
|
|
324fcf |
+
|
|
|
324fcf |
/* Start dispatching packets and timeouts... */
|
|
|
324fcf |
dispatch();
|
|
|
324fcf |
|