diff options
| -rw-r--r-- | bus/apparmor.c | 87 |
1 files changed, 86 insertions, 1 deletions
diff --git a/bus/apparmor.c b/bus/apparmor.c index 645bb846..3b2be352 100644 --- a/bus/apparmor.c +++ b/bus/apparmor.c @@ -64,6 +64,67 @@ static AppArmorConfigMode apparmor_config_mode = APPARMOR_ENABLED; static int audit_fd = -1; #endif +struct BusAppArmorConfinement +{ + int refcount; /* Reference count */ + + char *context; /* AppArmor confinement context (label) */ + const char *mode; /* AppArmor confinement mode (freed by freeing *context) */ +}; + +typedef struct BusAppArmorConfinement BusAppArmorConfinement; + +static BusAppArmorConfinement *bus_con = NULL; + +/** + * Callers of this function give up ownership of the *context and *mode + * pointers. + * + * Additionally, the responsibility of freeing *context and *mode becomes the + * responsibility of the bus_apparmor_confinement_unref() function. However, it + * does not free *mode because libapparmor's aa_getcon(), and libapparmor's + * other related functions, allocate a single buffer for *context and *mode and + * then separate the two char arrays with a NUL char. See the aa_getcon(2) man + * page for more details. + */ +static BusAppArmorConfinement* +bus_apparmor_confinement_new (char *context, const char *mode) +{ + BusAppArmorConfinement *confinement; + + confinement = dbus_new0 (BusAppArmorConfinement, 1); + if (confinement != NULL) + { + confinement->refcount = 1; + confinement->context = context; + confinement->mode = mode; + } + + return confinement; +} + +static void +bus_apparmor_confinement_unref (BusAppArmorConfinement *confinement) +{ + if (!apparmor_enabled) + return; + + _dbus_assert (confinement != NULL); + _dbus_assert (confinement->refcount > 0); + + confinement->refcount -= 1; + + if (confinement->refcount == 0) + { + /** + * Do not free confinement->mode, as libapparmor does a single malloc for + * both confinement->context and confinement->mode. + */ + free (confinement->context); + dbus_free (confinement); + } +} + void bus_apparmor_audit_init (void) { @@ -203,6 +264,8 @@ dbus_bool_t bus_apparmor_full_init (DBusError *error) { #ifdef HAVE_APPARMOR + char *context, *mode; + if (apparmor_enabled) { if (apparmor_config_mode == APPARMOR_DISABLED) @@ -210,13 +273,32 @@ bus_apparmor_full_init (DBusError *error) apparmor_enabled = FALSE; return TRUE; } + + if (bus_con == NULL) + { + if (aa_getcon (&context, &mode) == -1) + { + dbus_set_error (error, DBUS_ERROR_FAILED, + "Error getting AppArmor context of bus: %s", + _dbus_strerror (errno)); + return FALSE; + } + + bus_con = bus_apparmor_confinement_new (context, mode); + if (bus_con == NULL) + { + BUS_SET_OOM (error); + free (context); + return FALSE; + } + } } else { if (apparmor_config_mode == APPARMOR_REQUIRED) { dbus_set_error (error, DBUS_ERROR_FAILED, - "AppArmor mediation required but not present\n"); + "AppArmor mediation required but not present"); return FALSE; } else if (apparmor_config_mode == APPARMOR_ENABLED) @@ -238,6 +320,9 @@ bus_apparmor_shutdown (void) _dbus_verbose ("AppArmor shutdown\n"); + bus_apparmor_confinement_unref (bus_con); + bus_con = NULL; + #ifdef HAVE_LIBAUDIT audit_close (audit_fd); #endif /* HAVE_LIBAUDIT */ |