Add HAVE_LIBCAP

Currently it is impossible to build lxc with --disable-capabilities if
the user has libcap-dev installed on his system as:
 - calls to cap_xxx functions are not protected by HAVE_LIBCAP defines.
 The whole file is only protected by HAVE_SYS_CAPABILITY_H.
 - AC_CHECK_LIB default action-if-found is overriden by [true] so
 HAVE_LIBCAP is never written to config.h

This patch replaces all HAVE_SYS_CAPABILITY_H checks by HAVE_LIBCAP
checks (fix #1361)

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
This commit is contained in:
Fabrice Fontaine 2017-02-11 22:40:19 +01:00
parent 3a5cb1afff
commit e37dda7156
5 changed files with 13 additions and 12 deletions

View File

@ -370,7 +370,8 @@ fi
AM_CONDITIONAL([ENABLE_CAP], [test "x$enable_capabilities" = "xyes"]) AM_CONDITIONAL([ENABLE_CAP], [test "x$enable_capabilities" = "xyes"])
AM_COND_IF([ENABLE_CAP], AM_COND_IF([ENABLE_CAP],
[AC_CHECK_LIB(cap,cap_set_proc,[true],[AC_MSG_ERROR([You are missing libcap support.])]) [AC_CHECK_HEADER([sys/capability.h],[],[AC_MSG_ERROR([You must install the libcap development package in order to compile lxc])])
AC_CHECK_LIB(cap,cap_set_proc,[],[AC_MSG_ERROR([You must install the libcap development package in order to compile lxc])])
AC_SUBST([CAP_LIBS], [-lcap])]) AC_SUBST([CAP_LIBS], [-lcap])])
# HAVE_SCMP_FILTER_CTX=1 will tell us we have libseccomp api >= 1.0.0 # HAVE_SCMP_FILTER_CTX=1 will tell us we have libseccomp api >= 1.0.0
@ -638,7 +639,7 @@ AC_CHECK_DECLS([PR_SET_NO_NEW_PRIVS], [], [], [#include <sys/prctl.h>])
AC_CHECK_DECLS([PR_GET_NO_NEW_PRIVS], [], [], [#include <sys/prctl.h>]) AC_CHECK_DECLS([PR_GET_NO_NEW_PRIVS], [], [], [#include <sys/prctl.h>])
# Check for some headers # Check for some headers
AC_CHECK_HEADERS([sys/signalfd.h pty.h ifaddrs.h sys/capability.h sys/memfd.h sys/personality.h utmpx.h sys/timerfd.h]) AC_CHECK_HEADERS([sys/signalfd.h pty.h ifaddrs.h sys/memfd.h sys/personality.h utmpx.h sys/timerfd.h])
# lookup major()/minor()/makedev() # lookup major()/minor()/makedev()
AC_HEADER_MAJOR AC_HEADER_MAJOR

View File

@ -36,7 +36,7 @@
lxc_log_define(lxc_caps, lxc); lxc_log_define(lxc_caps, lxc);
#if HAVE_SYS_CAPABILITY_H #if HAVE_LIBCAP
#ifndef PR_CAPBSET_READ #ifndef PR_CAPBSET_READ
#define PR_CAPBSET_READ 23 #define PR_CAPBSET_READ 23

View File

@ -27,7 +27,7 @@
#ifndef __LXC_CAPS_H #ifndef __LXC_CAPS_H
#define __LXC_CAPS_H #define __LXC_CAPS_H
#if HAVE_SYS_CAPABILITY_H #if HAVE_LIBCAP
#include <sys/capability.h> #include <sys/capability.h>
extern int lxc_caps_down(void); extern int lxc_caps_down(void);

View File

@ -91,7 +91,7 @@
#include "utils.h" #include "utils.h"
#include "lsm/lsm.h" #include "lsm/lsm.h"
#if HAVE_SYS_CAPABILITY_H #if HAVE_LIBCAP
#include <sys/capability.h> #include <sys/capability.h>
#endif #endif
@ -107,7 +107,7 @@
lxc_log_define(lxc_conf, lxc); lxc_log_define(lxc_conf, lxc);
#if HAVE_SYS_CAPABILITY_H #if HAVE_LIBCAP
#ifndef CAP_SETFCAP #ifndef CAP_SETFCAP
#define CAP_SETFCAP 31 #define CAP_SETFCAP 31
#endif #endif
@ -316,7 +316,7 @@ static struct mount_opt mount_opt[] = {
{ NULL, 0, 0 }, { NULL, 0, 0 },
}; };
#if HAVE_SYS_CAPABILITY_H #if HAVE_LIBCAP
static struct caps_opt caps_opt[] = { static struct caps_opt caps_opt[] = {
{ "chown", CAP_CHOWN }, { "chown", CAP_CHOWN },
{ "dac_override", CAP_DAC_OVERRIDE }, { "dac_override", CAP_DAC_OVERRIDE },

View File

@ -46,7 +46,7 @@
#include <sys/un.h> #include <sys/un.h>
#include <sys/wait.h> #include <sys/wait.h>
#if HAVE_SYS_CAPABILITY_H #if HAVE_LIBCAP
#include <sys/capability.h> #include <sys/capability.h>
#endif #endif
@ -375,7 +375,7 @@ int lxc_poll(const char *name, struct lxc_handler *handler)
} }
if (handler->conf->need_utmp_watch) { if (handler->conf->need_utmp_watch) {
#if HAVE_SYS_CAPABILITY_H #if HAVE_LIBCAP
if (lxc_utmp_mainloop_add(&descr, handler)) { if (lxc_utmp_mainloop_add(&descr, handler)) {
ERROR("Failed to add utmp handler to LXC mainloop."); ERROR("Failed to add utmp handler to LXC mainloop.");
goto out_mainloop_open; goto out_mainloop_open;
@ -787,7 +787,7 @@ static int do_start(void *data)
goto out_warn_father; goto out_warn_father;
} }
#if HAVE_SYS_CAPABILITY_H #if HAVE_LIBCAP
if (handler->conf->need_utmp_watch) { if (handler->conf->need_utmp_watch) {
if (prctl(PR_CAPBSET_DROP, CAP_SYS_BOOT, 0, 0, 0)) { if (prctl(PR_CAPBSET_DROP, CAP_SYS_BOOT, 0, 0, 0)) {
SYSERROR("Failed to remove the CAP_SYS_BOOT capability."); SYSERROR("Failed to remove the CAP_SYS_BOOT capability.");
@ -898,7 +898,7 @@ static int do_start(void *data)
* further above. Only drop groups if we can, so ensure that we * further above. Only drop groups if we can, so ensure that we
* have necessary privilege. * have necessary privilege.
*/ */
#if HAVE_SYS_CAPABILITY_H #if HAVE_LIBCAP
have_cap_setgid = lxc_cap_is_set(CAP_SETGID, CAP_EFFECTIVE); have_cap_setgid = lxc_cap_is_set(CAP_SETGID, CAP_EFFECTIVE);
#else #else
have_cap_setgid = false; have_cap_setgid = false;
@ -1337,7 +1337,7 @@ int __lxc_start(const char *name, struct lxc_conf *conf,
handler->netnsfd = -1; handler->netnsfd = -1;
if (must_drop_cap_sys_boot(handler->conf)) { if (must_drop_cap_sys_boot(handler->conf)) {
#if HAVE_SYS_CAPABILITY_H #if HAVE_LIBCAP
DEBUG("Dropping CAP_SYS_BOOT capability."); DEBUG("Dropping CAP_SYS_BOOT capability.");
#else #else
DEBUG("Not dropping CAP_SYS_BOOT capability as capabilities aren't supported."); DEBUG("Not dropping CAP_SYS_BOOT capability as capabilities aren't supported.");