selinux: dynamic class/perm discovery

Modify SELinux to dynamically discover class and permission values
upon policy load, based on the dynamic object class/perm discovery
logic from libselinux.  A mapping is created between kernel-private
class and permission indices used outside the security server and the
policy values used within the security server.

The mappings are only applied upon kernel-internal computations;
similar mappings for the private indices of userspace object managers
is handled on a per-object manager basis by the userspace AVC.  The
interfaces for compute_av and transition_sid are split for kernel
vs. userspace; the userspace functions are distinguished by a _user
suffix.

The kernel-private class indices are no longer tied to the policy
values and thus do not need to skip indices for userspace classes;
thus the kernel class index values are compressed.  The flask.h
definitions were regenerated by deleting the userspace classes from
refpolicy's definitions and then regenerating the headers.  Going
forward, we can just maintain the flask.h, av_permissions.h, and
classmap.h definitions separately from policy as they are no longer
tied to the policy values.  The next patch introduces a utility to
automate generation of flask.h and av_permissions.h from the
classmap.h definitions.

The older kernel class and permission string tables are removed and
replaced by a single security class mapping table that is walked at
policy load to generate the mapping.  The old kernel class validation
logic is completely replaced by the mapping logic.

The handle unknown logic is reworked.  reject_unknown=1 is handled
when the mappings are computed at policy load time, similar to the old
handling by the class validation logic.  allow_unknown=1 is handled
when computing and mapping decisions - if the permission was not able
to be mapped (i.e. undefined, mapped to zero), then it is
automatically added to the allowed vector.  If the class was not able
to be mapped (i.e. undefined, mapped to zero), then all permissions
are allowed for it if allow_unknown=1.

avc_audit leverages the new security class mapping table to lookup the
class and permission names from the kernel-private indices.

The mdp program is updated to use the new table when generating the
class definitions and allow rules for a minimal boot policy for the
kernel.  It should be noted that this policy will not include any
userspace classes, nor will its policy index values for the kernel
classes correspond with the ones in refpolicy (they will instead match
the kernel-private indices).

Signed-off-by:  Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>

1 files changed, 20 insertions, 20 deletions

diff --git a/security/selinux/include/flask.h b/security/selinux/include/flask.h
index f248500a1e3c..5359ca2abf21 100644
--- a/security/selinux/include/flask.h
+++ b/security/selinux/include/flask.h
@@ -34,26 +34,26 @@
 #define SECCLASS_MSGQ                                    27
 #define SECCLASS_SHM                                     28
 #define SECCLASS_IPC                                     29
-#define SECCLASS_NETLINK_ROUTE_SOCKET                    43
-#define SECCLASS_NETLINK_FIREWALL_SOCKET                 44
-#define SECCLASS_NETLINK_TCPDIAG_SOCKET                  45
-#define SECCLASS_NETLINK_NFLOG_SOCKET                    46
-#define SECCLASS_NETLINK_XFRM_SOCKET                     47
-#define SECCLASS_NETLINK_SELINUX_SOCKET                  48
-#define SECCLASS_NETLINK_AUDIT_SOCKET                    49
-#define SECCLASS_NETLINK_IP6FW_SOCKET                    50
-#define SECCLASS_NETLINK_DNRT_SOCKET                     51
-#define SECCLASS_ASSOCIATION                             54
-#define SECCLASS_NETLINK_KOBJECT_UEVENT_SOCKET           55
-#define SECCLASS_APPLETALK_SOCKET                        56
-#define SECCLASS_PACKET                                  57
-#define SECCLASS_KEY                                     58
-#define SECCLASS_DCCP_SOCKET                             60
-#define SECCLASS_MEMPROTECT                              61
-#define SECCLASS_PEER                                    68
-#define SECCLASS_CAPABILITY2                             69
-#define SECCLASS_KERNEL_SERVICE                          74
-#define SECCLASS_TUN_SOCKET                              75
+#define SECCLASS_NETLINK_ROUTE_SOCKET                    30
+#define SECCLASS_NETLINK_FIREWALL_SOCKET                 31
+#define SECCLASS_NETLINK_TCPDIAG_SOCKET                  32
+#define SECCLASS_NETLINK_NFLOG_SOCKET                    33
+#define SECCLASS_NETLINK_XFRM_SOCKET                     34
+#define SECCLASS_NETLINK_SELINUX_SOCKET                  35
+#define SECCLASS_NETLINK_AUDIT_SOCKET                    36
+#define SECCLASS_NETLINK_IP6FW_SOCKET                    37
+#define SECCLASS_NETLINK_DNRT_SOCKET                     38
+#define SECCLASS_ASSOCIATION                             39
+#define SECCLASS_NETLINK_KOBJECT_UEVENT_SOCKET           40
+#define SECCLASS_APPLETALK_SOCKET                        41
+#define SECCLASS_PACKET                                  42
+#define SECCLASS_KEY                                     43
+#define SECCLASS_DCCP_SOCKET                             44
+#define SECCLASS_MEMPROTECT                              45
+#define SECCLASS_PEER                                    46
+#define SECCLASS_CAPABILITY2                             47
+#define SECCLASS_KERNEL_SERVICE                          48
+#define SECCLASS_TUN_SOCKET                              49
 
 /*
  * Security identifier indices for initial entities