diff options
Diffstat (limited to 'nscd/selinux.c')
| -rw-r--r-- | nscd/selinux.c | 154 |
1 files changed, 153 insertions, 1 deletions
diff --git a/nscd/selinux.c b/nscd/selinux.c index f57f0920ae..b826031150 100644 --- a/nscd/selinux.c +++ b/nscd/selinux.c @@ -1,5 +1,5 @@ /* SELinux access controls for nscd. - Copyright (C) 2004 Free Software Foundation, Inc. + Copyright (C) 2004, 2005, 2006, 2007 Free Software Foundation, Inc. This file is part of the GNU C Library. Contributed by Matthew Rickard <mjricka@epoch.ncsc.mil>, 2004. @@ -18,6 +18,7 @@ Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. */ +#include "config.h" #include <error.h> #include <errno.h> #include <libintl.h> @@ -26,10 +27,15 @@ #include <stdio.h> #include <stdlib.h> #include <syslog.h> +#include <unistd.h> +#include <sys/prctl.h> #include <selinux/av_permissions.h> #include <selinux/avc.h> #include <selinux/flask.h> #include <selinux/selinux.h> +#ifdef HAVE_LIBAUDIT +# include <libaudit.h> +#endif #include "dbg_log.h" #include "selinux.h" @@ -66,6 +72,11 @@ static struct avc_entry_ref aeref; /* Thread to listen for SELinux status changes via netlink. */ static pthread_t avc_notify_thread; +#ifdef HAVE_LIBAUDIT +/* Prototype for supporting the audit daemon */ +static void log_callback (const char *fmt, ...); +#endif + /* Prototypes for AVC callback functions. */ static void *avc_create_thread (void (*run) (void)); static void avc_stop_thread (void *thread); @@ -77,7 +88,11 @@ static void avc_free_lock (void *lock); /* AVC callback structures for use in avc_init. */ static const struct avc_log_callback log_cb = { +#ifdef HAVE_LIBAUDIT + .func_log = log_callback, +#else .func_log = dbg_log, +#endif .func_audit = NULL }; static const struct avc_thread_callback thread_cb = @@ -93,6 +108,137 @@ static const struct avc_lock_callback lock_cb = .func_free_lock = avc_free_lock }; +#ifdef HAVE_LIBAUDIT +/* The audit system's netlink socket descriptor */ +static int audit_fd = -1; + +/* When an avc denial occurs, log it to audit system */ +static void +log_callback (const char *fmt, ...) +{ + if (audit_fd >= 0) + { + va_list ap; + va_start (ap, fmt); + + char *buf; + int e = vasprintf (&buf, fmt, ap); + if (e < 0) + { + buf = alloca (BUFSIZ); + vsnprintf (buf, BUFSIZ, fmt, ap); + } + + /* FIXME: need to attribute this to real user, using getuid for now */ + audit_log_user_avc_message (audit_fd, AUDIT_USER_AVC, buf, NULL, NULL, + NULL, getuid ()); + + if (e >= 0) + free (buf); + + va_end (ap); + } +} + +/* Initialize the connection to the audit system */ +static void +audit_init (void) +{ + audit_fd = audit_open (); + if (audit_fd < 0 + /* If kernel doesn't support audit, bail out */ + && errno != EINVAL && errno != EPROTONOSUPPORT && errno != EAFNOSUPPORT) + dbg_log (_("Failed opening connection to the audit subsystem: %m")); +} + + +# ifdef HAVE_LIBCAP +static const cap_value_t new_cap_list[] = + { CAP_AUDIT_WRITE }; +# define nnew_cap_list (sizeof (new_cap_list) / sizeof (new_cap_list[0])) +static const cap_value_t tmp_cap_list[] = + { CAP_AUDIT_WRITE, CAP_SETUID, CAP_SETGID }; +# define ntmp_cap_list (sizeof (tmp_cap_list) / sizeof (tmp_cap_list[0])) + +cap_t +preserve_capabilities (void) +{ + if (getuid () != 0) + /* Not root, then we cannot preserve anything. */ + return NULL; + + if (prctl (PR_SET_KEEPCAPS, 1) == -1) + { + dbg_log (_("Failed to set keep-capabilities")); + error (EXIT_FAILURE, errno, _("prctl(KEEPCAPS) failed")); + /* NOTREACHED */ + } + + cap_t tmp_caps = cap_init (); + cap_t new_caps; + if (tmp_caps != NULL) + new_caps = cap_init (); + + if (tmp_caps == NULL || new_caps == NULL) + { + if (tmp_caps != NULL) + cap_free (tmp_caps); + + dbg_log (_("Failed to initialize drop of capabilities")); + error (EXIT_FAILURE, 0, _("cap_init failed")); + } + + /* There is no reason why these should not work. */ + cap_set_flag (new_caps, CAP_PERMITTED, nnew_cap_list, + (cap_value_t *) new_cap_list, CAP_SET); + cap_set_flag (new_caps, CAP_EFFECTIVE, nnew_cap_list, + (cap_value_t *) new_cap_list, CAP_SET); + + cap_set_flag (tmp_caps, CAP_PERMITTED, ntmp_cap_list, + (cap_value_t *) tmp_cap_list, CAP_SET); + cap_set_flag (tmp_caps, CAP_EFFECTIVE, ntmp_cap_list, + (cap_value_t *) tmp_cap_list, CAP_SET); + + int res = cap_set_proc (tmp_caps); + + cap_free (tmp_caps); + + if (__builtin_expect (res != 0, 0)) + { + cap_free (new_caps); + dbg_log (_("Failed to drop capabilities\n")); + error (EXIT_FAILURE, 0, _("cap_set_proc failed")); + } + + return new_caps; +} + +void +install_real_capabilities (cap_t new_caps) +{ + /* If we have no capabilities there is nothing to do here. */ + if (new_caps == NULL) + return; + + if (cap_set_proc (new_caps)) + { + cap_free (new_caps); + dbg_log (_("Failed to drop capabilities")); + error (EXIT_FAILURE, 0, _("cap_set_proc failed")); + /* NOTREACHED */ + } + + cap_free (new_caps); + + if (prctl (PR_SET_KEEPCAPS, 0) == -1) + { + dbg_log (_("Failed to unset keep-capabilities")); + error (EXIT_FAILURE, errno, _("prctl(KEEPCAPS) failed")); + /* NOTREACHED */ + } +} +# endif /* HAVE_LIBCAP */ +#endif /* HAVE_LIBAUDIT */ /* Determine if we are running on an SELinux kernel. Set selinux_enabled to the result. */ @@ -182,6 +328,9 @@ nscd_avc_init (void) error (EXIT_FAILURE, errno, _("Failed to start AVC")); else dbg_log (_("Access Vector Cache (AVC) started")); +#ifdef HAVE_LIBAUDIT + audit_init (); +#endif } @@ -262,6 +411,9 @@ void nscd_avc_destroy (void) { avc_destroy (); +#ifdef HAVE_LIBAUDIT + audit_close (audit_fd); +#endif } #endif /* HAVE_SELINUX */ |