Commit c4a43656 authored by Ondřej Surý's avatar Ondřej Surý

Make libcap mandatory when Linux capabilities are enabled

parent 8d9196be
......@@ -72,11 +72,13 @@ DEPLIBS = ${NSDEPLIBS} ${DNSDEPLIBS} ${BIND9DEPLIBS} \
LIBS = ${NSLIBS} ${DNSLIBS} ${BIND9LIBS} \
${ISCCFGLIBS} ${ISCCCLIBS} ${ISCLIBS} \
${DLZDRIVER_LIBS} ${DBDRIVER_LIBS} @LIBS@
${DLZDRIVER_LIBS} ${DBDRIVER_LIBS} @LIBCAP_LIBS@ \
@LIBS@
NOSYMLIBS = ${NSLIBS} ${DNSLIBS} ${BIND9LIBS} \
${ISCCFGLIBS} ${ISCCCLIBS} ${ISCNOSYMLIBS} \
${DLZDRIVER_LIBS} ${DBDRIVER_LIBS} @LIBS@
${DLZDRIVER_LIBS} ${DBDRIVER_LIBS} @LIBCAP_LIBS@ \
@LIBS@
SUBDIRS = unix
......
......@@ -61,14 +61,14 @@ static int singletonfd = -1;
/*
* If there's no <linux/capability.h>, we don't care about <sys/prctl.h>
*/
#ifndef HAVE_LINUX_CAPABILITY_H
#ifndef WANT_LINUX_CAPABILITY
#undef HAVE_SYS_PRCTL_H
#endif
/*
* Linux defines:
* (T) HAVE_LINUXTHREADS
* (C) HAVE_SYS_CAPABILITY_H (or HAVE_LINUX_CAPABILITY_H)
* (C) WANT_LINUX_CAPABILITY
* (P) HAVE_SYS_PRCTL_H
* The possible cases are:
* none: setuid() normally
......@@ -110,35 +110,18 @@ static struct passwd *runas_pw = NULL;
static isc_boolean_t done_setuid = ISC_FALSE;
static int dfd[2] = { -1, -1 };
#ifdef HAVE_LINUX_CAPABILITY_H
#if WANT_LINUX_CAPABILITY
static isc_boolean_t non_root = ISC_FALSE;
static isc_boolean_t non_root_caps = ISC_FALSE;
#ifdef HAVE_SYS_CAPABILITY_H
#if HAVE_SYS_CAPABILITY_H
#include <sys/capability.h>
#else
#ifdef HAVE_LINUX_TYPES_H
#include <linux/types.h>
#endif
/*%
* We define _LINUX_FS_H to prevent it from being included. We don't need
* anything from it, and the files it includes cause warnings with 2.2
* kernels, and compilation failures (due to conflicts between <linux/string.h>
* and <string.h>) on 2.3 kernels.
*/
#define _LINUX_FS_H
#include <linux/capability.h>
#include <syscall.h>
#ifndef SYS_capset
#ifndef __NR_capset
#include <asm/unistd.h> /* Slackware 4.0 needs this. */
#endif /* __NR_capset */
#define SYS_capset __NR_capset
#endif /* SYS_capset */
#endif /* HAVE_SYS_CAPABILITY_H */
#ifdef HAVE_SYS_PRCTL_H
#if WANT_LINUX_CAPABILITY && HAVE_SYS_PRCTL_H
#include <sys/prctl.h> /* Required for prctl(). */
/*
......@@ -153,46 +136,22 @@ static isc_boolean_t non_root_caps = ISC_FALSE;
#endif /* HAVE_SYS_PRCTL_H */
#ifdef HAVE_LIBCAP
#define SETCAPS_FUNC "cap_set_proc "
#else
typedef unsigned int cap_t;
#define SETCAPS_FUNC "syscall(capset) "
#endif /* HAVE_LIBCAP */
static void
linux_setcaps(cap_t caps) {
#ifndef HAVE_LIBCAP
struct __user_cap_header_struct caphead;
struct __user_cap_data_struct cap;
#endif
char strbuf[ISC_STRERRORSIZE];
if ((getuid() != 0 && !non_root_caps) || non_root)
if ((getuid() != 0 && !non_root_caps) || non_root) {
return;
#ifndef HAVE_LIBCAP
memset(&caphead, 0, sizeof(caphead));
caphead.version = _LINUX_CAPABILITY_VERSION;
caphead.pid = 0;
memset(&cap, 0, sizeof(cap));
cap.effective = caps;
cap.permitted = caps;
cap.inheritable = 0;
#endif
#ifdef HAVE_LIBCAP
}
if (cap_set_proc(caps) < 0) {
#else
if (syscall(SYS_capset, &caphead, &cap) < 0) {
#endif
isc__strerror(errno, strbuf, sizeof(strbuf));
named_main_earlyfatal(SETCAPS_FUNC "failed: %s:"
named_main_earlyfatal("cap_set_proc() failed: %s:"
" please ensure that the capset kernel"
" module is loaded. see insmod(8)",
strbuf);
}
}
#ifdef HAVE_LIBCAP
#define SET_CAP(flag) \
do { \
cap_flag_value_t curval; \
......@@ -230,20 +189,14 @@ linux_setcaps(cap_t caps) {
cap_free(caps); \
cap_free(curcaps); \
} while (0)
#else
#define SET_CAP(flag) do { caps |= (1 << (flag)); } while (0)
#define INIT_CAP do { caps = 0; } while (0)
#endif /* HAVE_LIBCAP */
static void
linux_initialprivs(void) {
cap_t caps;
#ifdef HAVE_LIBCAP
cap_t curcaps;
cap_value_t capval;
char strbuf[ISC_STRERRORSIZE];
int err;
#endif
/*%
* We don't need most privileges, so we drop them right away.
......@@ -300,20 +253,16 @@ linux_initialprivs(void) {
linux_setcaps(caps);
#ifdef HAVE_LIBCAP
FREE_CAP;
#endif
}
static void
linux_minprivs(void) {
cap_t caps;
#ifdef HAVE_LIBCAP
cap_t curcaps;
cap_value_t capval;
char strbuf[ISC_STRERRORSIZE];
int err;
#endif
INIT_CAP;
/*%
......@@ -337,12 +286,10 @@ linux_minprivs(void) {
linux_setcaps(caps);
#ifdef HAVE_LIBCAP
FREE_CAP;
#endif
}
#ifdef HAVE_SYS_PRCTL_H
#if WANT_LINUX_CAPABILITY && HAVE_SYS_PRCTL_H
static void
linux_keepcaps(void) {
char strbuf[ISC_STRERRORSIZE];
......@@ -364,7 +311,7 @@ linux_keepcaps(void) {
}
#endif
#endif /* HAVE_LINUX_CAPABILITY_H */
#endif /* WANT_LINUX_CAPABILITY */
static void
......@@ -381,7 +328,7 @@ setup_syslog(const char *progname) {
void
named_os_init(const char *progname) {
setup_syslog(progname);
#ifdef HAVE_LINUX_CAPABILITY_H
#if WANT_LINUX_CAPABILITY
linux_initialprivs();
#endif
#ifdef HAVE_LINUXTHREADS
......@@ -567,11 +514,12 @@ named_os_changeuser(void) {
done_setuid = ISC_TRUE;
#ifdef HAVE_LINUXTHREADS
#ifdef HAVE_LINUX_CAPABILITY_H
if (!non_root_caps)
#if WANT_LINUX_CAPABILITY
if (!non_root_caps) {
named_main_earlyfatal("-u with Linux threads not supported: "
"requires kernel support for "
"prctl(PR_SET_KEEPCAPS)");
}
#else
named_main_earlyfatal("-u with Linux threads not supported: "
"no capabilities support or capabilities "
......@@ -600,7 +548,7 @@ named_os_changeuser(void) {
strbuf);
}
#endif
#if defined(HAVE_LINUX_CAPABILITY_H) && !defined(HAVE_LINUXTHREADS)
#if defined(WANT_LINUX_CAPABILITY) && !defined(HAVE_LINUXTHREADS)
linux_minprivs();
#endif
}
......@@ -632,7 +580,7 @@ named_os_adjustnofile(void) {
void
named_os_minprivs(void) {
#ifdef HAVE_SYS_PRCTL_H
#if WANT_LINUX_CAPABILITY && HAVE_SYS_PRCTL_H
linux_keepcaps();
#endif
......@@ -640,7 +588,7 @@ named_os_minprivs(void) {
named_os_changeuser(); /* Call setuid() before threads are started */
#endif
#if defined(HAVE_LINUX_CAPABILITY_H) && defined(HAVE_LINUXTHREADS)
#if WANT_LINUX_CAPABILITY && defined(HAVE_LINUXTHREADS)
linux_minprivs();
#endif
}
......
......@@ -317,9 +317,6 @@ int sigwait(const unsigned int *set, int *sig);
/* Define to 1 if you have the `c' library (-lc). */
#undef HAVE_LIBC
/* Define to 1 if you have the `cap' library (-lcap). */
#undef HAVE_LIBCAP
/* if system have backtrace function */
#undef HAVE_LIBCTRACE
......@@ -347,18 +344,12 @@ int sigwait(const unsigned int *set, int *sig);
/* Define if libxml2 was found */
#undef HAVE_LIBXML2
/* Define to 1 if you have the <linux/capability.h> header file. */
#undef HAVE_LINUX_CAPABILITY_H
/* Define to 1 if you have the <linux/netlink.h> header file. */
#undef HAVE_LINUX_NETLINK_H
/* Define to 1 if you have the <linux/rtnetlink.h> header file. */
#undef HAVE_LINUX_RTNETLINK_H
/* Define to 1 if you have the <linux/types.h> header file. */
#undef HAVE_LINUX_TYPES_H
/* Define if lmdb was found */
#undef HAVE_LMDB
......@@ -626,6 +617,9 @@ int sigwait(const unsigned int *set, int *sig);
/* the default value of dnssec-validation option */
#undef VALIDATION_DEFAULT
/* define if you want to have Linux capabilities support */
#undef WANT_LINUX_CAPABILITY
/* Define to enable very verbose query trace logging. */
#undef WANT_QUERYTRACE
......
......@@ -725,6 +725,7 @@ ISC_PLATFORM_USEDECLSPEC
ISC_PLATFORM_RLIMITTYPE
ISC_PLATFORM_HAVESTATNSEC
ISC_PLATFORM_HAVESYSUNH
LIBCAP_LIBS
ISC_PLATFORM_QUADFORMAT
DST_EXTRA_SRCS
DST_EXTRA_OBJS
......@@ -1701,7 +1702,7 @@ Optional Features:
--enable-getifaddrs enable the use of getifaddrs() [yes|no].
--disable-isc-spnego use SPNEGO from GSSAPI library
--disable-chroot disable chroot
--disable-linux-caps disable linux capabilities
--disable-linux-caps disable Linux capabilities
--enable-atomic enable machine specific atomic operations
[default=autodetect]
--enable-fixed-rrset enable fixed rrset ordering [default=no]
......@@ -19795,26 +19796,27 @@ done
no)
;;
esac
LIBCAP_LIBS=""
{ $as_echo "$as_me:${as_lineno-$LINENO}: checking whether to enable Linux capabilities" >&5
$as_echo_n "checking whether to enable Linux capabilities... " >&6; }
# Check whether --enable-linux-caps was given.
if test "${enable_linux_caps+set}" = set; then :
enableval=$enable_linux_caps;
else
case $host in #(
*-linux*) :
enable_linux_caps=yes ;; #(
*) :
enable_linux_caps=no ;;
esac
fi
case "$enable_linux_caps" in
yes|'')
for ac_header in linux/types.h
do :
ac_fn_c_check_header_mongrel "$LINENO" "linux/types.h" "ac_cv_header_linux_types_h" "$ac_includes_default"
if test "x$ac_cv_header_linux_types_h" = xyes; then :
cat >>confdefs.h <<_ACEOF
#define HAVE_LINUX_TYPES_H 1
_ACEOF
fi
done
for ac_header in sys/capability.h
if test "$enable_linux_caps" = "yes"; then :
{ $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
$as_echo "yes" >&6; }
for ac_header in sys/capability.h
do :
ac_fn_c_check_header_mongrel "$LINENO" "sys/capability.h" "ac_cv_header_sys_capability_h" "$ac_includes_default"
if test "x$ac_cv_header_sys_capability_h" = xyes; then :
......@@ -19822,33 +19824,19 @@ if test "x$ac_cv_header_sys_capability_h" = xyes; then :
#define HAVE_SYS_CAPABILITY_H 1
_ACEOF
else
as_fn_error $? "sys/capability.h header is required for Linux capabilities support" "$LINENO" 5
fi
done
for ac_header in linux/capability.h
do :
ac_fn_c_check_header_compile "$LINENO" "linux/capability.h" "ac_cv_header_linux_capability_h" "#ifdef HAVE_LINUX_TYPES_H
#include <linux/types.h>
#endif
"
if test "x$ac_cv_header_linux_capability_h" = xyes; then :
cat >>confdefs.h <<_ACEOF
#define HAVE_LINUX_CAPABILITY_H 1
_ACEOF
fi
done
{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for cap_set_proc in -lcap" >&5
$as_echo_n "checking for cap_set_proc in -lcap... " >&6; }
if ${ac_cv_lib_cap_cap_set_proc+:} false; then :
save_LIBS="$LIBS"
{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for library containing cap_set_proc" >&5
$as_echo_n "checking for library containing cap_set_proc... " >&6; }
if ${ac_cv_search_cap_set_proc+:} false; then :
$as_echo_n "(cached) " >&6
else
ac_check_lib_save_LIBS=$LIBS
LIBS="-lcap $LIBS"
ac_func_search_save_LIBS=$LIBS
cat confdefs.h - <<_ACEOF >conftest.$ac_ext
/* end confdefs.h. */
......@@ -19867,30 +19855,47 @@ return cap_set_proc ();
return 0;
}
_ACEOF
if ac_fn_c_try_link "$LINENO"; then :
ac_cv_lib_cap_cap_set_proc=yes
else
ac_cv_lib_cap_cap_set_proc=no
for ac_lib in '' cap; do
if test -z "$ac_lib"; then
ac_res="none required"
else
ac_res=-l$ac_lib
LIBS="-l$ac_lib $ac_func_search_save_LIBS"
fi
if ac_fn_c_try_link "$LINENO"; then :
ac_cv_search_cap_set_proc=$ac_res
fi
rm -f core conftest.err conftest.$ac_objext \
conftest$ac_exeext conftest.$ac_ext
LIBS=$ac_check_lib_save_LIBS
conftest$ac_exeext
if ${ac_cv_search_cap_set_proc+:} false; then :
break
fi
{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_lib_cap_cap_set_proc" >&5
$as_echo "$ac_cv_lib_cap_cap_set_proc" >&6; }
if test "x$ac_cv_lib_cap_cap_set_proc" = xyes; then :
cat >>confdefs.h <<_ACEOF
#define HAVE_LIBCAP 1
_ACEOF
done
if ${ac_cv_search_cap_set_proc+:} false; then :
LIBS="-lcap $LIBS"
else
ac_cv_search_cap_set_proc=no
fi
rm conftest.$ac_ext
LIBS=$ac_func_search_save_LIBS
fi
{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_cap_set_proc" >&5
$as_echo "$ac_cv_search_cap_set_proc" >&6; }
ac_res=$ac_cv_search_cap_set_proc
if test "$ac_res" != no; then :
test "$ac_res" = "none required" || LIBS="$ac_res $LIBS"
LIBCAP_LIBS="$ac_cv_search_cap_set_proc"
else
as_fn_error $? "libcap is required for Linux capabilities support" "$LINENO" 5
fi
LIBS="$save_LIBS"
else
{ $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
$as_echo "no" >&6; }
fi
;;
no)
;;
esac
for ac_header in sys/prctl.h
do :
ac_fn_c_check_header_mongrel "$LINENO" "sys/prctl.h" "ac_cv_header_sys_prctl_h" "$ac_includes_default"
......
......@@ -3570,23 +3570,30 @@ case "$enable_chroot" in
no)
;;
esac
AC_ARG_ENABLE(linux-caps,
AS_HELP_STRING([--disable-linux-caps],
[disable linux capabilities]))
case "$enable_linux_caps" in
yes|'')
AC_CHECK_HEADERS(linux/types.h)
AC_CHECK_HEADERS([sys/capability.h])
AC_CHECK_HEADERS([linux/capability.h], [], [],
[#ifdef HAVE_LINUX_TYPES_H
#include <linux/types.h>
#endif
])
AC_CHECK_LIB(cap, cap_set_proc)
;;
no)
;;
esac
LIBCAP_LIBS=""
AC_MSG_CHECKING([whether to enable Linux capabilities])
AC_ARG_ENABLE([linux-caps],
[AS_HELP_STRING([--disable-linux-caps],
[disable Linux capabilities])],
[],
[AS_CASE([$host],
[*-linux*],[enable_linux_caps=yes],
[enable_linux_caps=no])])
AS_IF([test "$enable_linux_caps" = "yes"],
[AC_MSG_RESULT([yes])
AC_CHECK_HEADERS([sys/capability.h],
[],
[AC_MSG_ERROR([sys/capability.h header is required for Linux capabilities support])])
save_LIBS="$LIBS"
AC_SEARCH_LIBS([cap_set_proc], [cap],
[LIBCAP_LIBS="$ac_cv_search_cap_set_proc"],
[AC_MSG_ERROR([libcap is required for Linux capabilities support])])
LIBS="$save_LIBS"],
[AC_MSG_RESULT([no])])
AC_SUBST([LIBCAP_LIBS])
AC_CHECK_HEADERS(sys/prctl.h)
AC_CHECK_HEADERS(sys/un.h,
......
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