Selinux grammar

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(perhaps very close to a usabel state)
 
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A file must contain either a base_policy or a module_policy.
 
A file must contain either a base_policy or a module_policy.
  
----
+
== base policy ==
  
 
base_policy = class_def+ initial_sid_def+ access_vectors [mls] te_rbac user_def+ [constraint_decl+] initial_sid_context_def+ [fs_context_def+] [fs_use_def+] [genfs_context_def+] [port_context_def+] [netif_context_def+] [node_context_def+]
 
base_policy = class_def+ initial_sid_def+ access_vectors [mls] te_rbac user_def+ [constraint_decl+] initial_sid_context_def+ [fs_context_def+] [fs_use_def+] [genfs_context_def+] [port_context_def+] [netif_context_def+] [node_context_def+]
Line 32: Line 32:
 
initial_sid_def = '''SID''' ''<identifier>''
 
initial_sid_def = '''SID''' ''<identifier>''
  
access_vectors = [common_perms] av_perms_def+
+
access_vectors = [common_perms_def +] av_perms_def+
  
av_perms_def = '''CLASS''' ''<identifier>'' '''{''' identifier_list '''}''' | '''CLASS''' ''<identifier>'' '''INHERITS''' ''<identifier>''  | '''CLASS''' ''<identifier>'' '''INHERITS''' ''<identifier>'' '''{''' identifier_list '''}'''
+
av_perms_def = '''CLASS''' ''<identifier>'' '''{''' ''<identifier>'' + '''}''' | '''CLASS''' ''<identifier>'' '''INHERITS''' ''<identifier>''  | '''CLASS''' ''<identifier>'' '''INHERITS''' ''<identifier>'' '''{''' ''<identifier>'' + '''}'''
  
 
initial_sid_context_def = '''SID''' ''<identifier>'' security_context_def
 
initial_sid_context_def = '''SID''' ''<identifier>'' security_context_def
Line 45: Line 45:
  
 
----
 
----
 +
 +
fs_context_def = '''FSCON''' ''<number>'' ''<number>'' security_context_def security_context_def
 +
 +
port_context_def = '''PORTCON''' ''<identifier>'' ''<number>'' security_context_def | '''PORTCON''' ''<identifier>'' ''<number>'' '-' ''<number>'' security_context_def
 +
 +
netif_context_def = '''NETIFCON''' ''<identifier>'' security_context_def security_context_def
 +
 +
node_context_def = '''NODECON''' ''<ipv4_addr>'' ''<ipv4_addr>'' security_context_def | '''NODECON''' ''<ipv6_addr>'' ''<ipv6_addr>'' security_context_def
 +
 +
fs_use_def = '''FSUSEXATTR''' ''<identifier>'' security_context_def ''';''' | '''FSUSETASK''' ''<identifier>'' security_context_def ''';''' | '''FSUSETRANS''' ''<identifier>'' security_context_def ''';'''
 +
 +
genfs_context_def = '''GENFSCON''' ''<identifier>'' ''<path>'' '-' ''<identifier>'' security_context_def | '''GENFSCON''' ''<identifier>'' ''<path>'' '-' '-'  security_context_def | '''GENFSCON''' ''<identifier>'' ''<path>'' security_context_def
 +
 +
security_context_def = ''<identifier>'' ''':''' ''<identifier>'' ''':''' ''<identifier>'' [''':''' mls_range_def]
 +
 +
----
 +
 +
mls_range_def = mls_level_def '-' mls_level_def | mls_level_def
 +
 +
mls_level_def = ''<identifier>'' ''':''' id_comma_list | ''<identifier>''
 +
 +
id_comma_list = ''<identifier>'' | id_comma_list ',' ''<identifier>''
 +
 +
== module policy ==
  
 
module_policy = '''MODULE''' ''<identifier>'' ''<version_identifier>'' ''';''' avrules_block
 
module_policy = '''MODULE''' ''<identifier>'' ''<version_identifier>'' ''';''' avrules_block
Line 58: Line 82:
 
rbac_decl = role_type_def | role_dominance | role_trans_def | role_allow_def
 
rbac_decl = role_type_def | role_dominance | role_trans_def | role_allow_def
  
te_decl = '''ATTRIBUTE''' ''<identifier>'' ''';''' | type_def | '''TYPEALIAS''' ''<identifier>'' alias_def ''';''' | '''TYPEATTRIBUTE''' ''<identifier>'' id_comma_list ''';''' | '''BOOL''' ''<identifier>'' bool_val ''';''' | transition_def | range_trans_def | te_avtab_def | '''PERMISSIVE''' ''<identifier>'' ''';'''
+
role_type_def = '''ROLE''' ''<identifier>'' '''TYPES''' names ''';''' | '''ROLE''' ''<identifier>''';'
 +
 
 +
role_dominance = '''DOMINANCE''' '''{''' role_def+ '''}'''
 +
 
 +
role_allow_def = '''ALLOW''' names names ''';'''
 +
 
 +
role_trans_def = '''ROLE_TRANSITION''' names names ''<identifier>'' ''';'''
 +
 
 +
role_def = '''ROLE''' ''<identifier>'' ''';''' | '''ROLE''' ''<identifier>'' '''{''' role_def+ '''}'''
 +
 
 +
te_decl = '''ATTRIBUTE''' ''<identifier>'' ''';''' | type_def | '''TYPEALIAS''' ''<identifier>'' alias_def ''';''' | '''TYPEATTRIBUTE''' ''<identifier>'' id_comma_list ''';''' | '''BOOL''' ''<identifier>'' ('''CTRUE''' | '''CFALSE''') ''';''' | transition_def | range_trans_def | te_avtab_def | '''PERMISSIVE''' ''<identifier>'' ''';'''
  
te_rbac = ( te_decl | rbac_decl | cond_stmt_def | optional_block | policycap_def | ''';''' )+
+
te_rbac = ( te_decl | rbac_decl | cond_stmt_def | optional_block | POLICYCAP ''<identifier>'' ''';''' | ''';''' )+
  
 
te_avtab_def = '''ALLOW''' names names ''':''' names names  ''';''' | '''AUDITALLOW''' names names ''':''' names names ''';''' | '''AUDITDENY''' names names ''':''' names names ''';''' | '''DONTAUDIT''' names names ''':''' names names ''';''' | '''NEVERALLOW''' names names ''':''' names names  ''';'''
 
te_avtab_def = '''ALLOW''' names names ''':''' names names  ''';''' | '''AUDITALLOW''' names names ''':''' names names ''';''' | '''AUDITDENY''' names names ''':''' names names ''';''' | '''DONTAUDIT''' names names ''':''' names names ''';''' | '''NEVERALLOW''' names names ''':''' names names  ''';'''
Line 68: Line 102:
 
require_block = '''REQUIRE''' '''{''' require_decl+ '''}'''
 
require_block = '''REQUIRE''' '''{''' require_decl+ '''}'''
  
require_decl = require_class ''';''' | require_decl_def require_id_list ''';'''
+
require_decl = CLASS ''<identifier>'' names ''';''' | (ROLE | TYPE | ATTRIBUTE | USER | BOOL | SENSITIVITY | CATEGORY) ''<identifier>'' (''',''' ''<identifier>'' )* ''';'''
  
 
----
 
----
Line 76: Line 110:
 
----
 
----
  
cond_stmt_def = '''IF''' cond_expr '''{''' cond_pol_list '''}''' [ '''ELSE''' '''{''' cond_pol_list '''}''' ]
+
cond_stmt_def = '''IF''' cond_expr '''{''' cond_rule_def* '''}''' [ '''ELSE''' '''{''' cond_rule_def* '''}''' ]
  
 
cond_expr = '(' cond_expr ')' | '''NOT''' cond_expr | cond_expr '''AND''' cond_expr | cond_expr '''OR''' cond_expr | cond_expr '''XOR''' cond_expr | cond_expr '''EQUALS''' cond_expr | cond_expr '''NOTEQUAL''' cond_expr | ''<identifier>''
 
cond_expr = '(' cond_expr ')' | '''NOT''' cond_expr | cond_expr '''AND''' cond_expr | cond_expr '''OR''' cond_expr | cond_expr '''XOR''' cond_expr | cond_expr '''EQUALS''' cond_expr | cond_expr '''NOTEQUAL''' cond_expr | ''<identifier>''
  
----
+
cond_rule_def = cond_transition_def | cond_te_avtab_def | require_block
  
type_def = '''TYPE''' ''<identifier>'' alias_def [',' id_comma_list] ''';''' | '''TYPE''' ''<identifier>'' [',' id_comma_list] ''';'''
+
cond_transition_def = '''TYPE_TRANSITION''' names names ':' names ''<identifier>'' ';' | '''TYPE_MEMBER''' names names ':' names ''<identifier>'' ';' | '''TYPE_CHANGE''' names names ':' names ''<identifier>'' ';'
 +
 
 +
cond_te_avtab_def = '''ALLOW''' names names ''':''' names names  ''';''' | '''AUDITALLOW''' names names ''':''' names names ''';''' | '''AUDITDENY''' names names ''':''' names names ''';''' | '''DONTAUDIT''' names names ''':''' names names ''';'''
  
 
----
 
----
  
Some token definations:
+
type_def = '''TYPE''' ''<identifier>'' alias_def [',' id_comma_list] ''';''' | '''TYPE''' ''<identifier>'' [',' id_comma_list] ''';'''
 
+
version_identifier = xxx
+
  
 
----
 
----
Line 96: Line 130:
 
----
 
----
  
common_perms = common_perms_def | common_perms common_perms_def
+
common_perms_def = '''COMMON''' ''<identifier>'' '''{''' ''<identifier>'' + '''}'''
  
common_perms_def = '''COMMON''' ''<identifier>'' '''{''' identifier_list '''}'''
+
mls = sensitivity_def+ dominance [category_def+] level_def+ mlspolicy_decl+
  
mls = sensitivities dominance [categories] levels mlspolicy
+
sensitivity_def = '''SENSITIVITY''' ''<identifier>'' alias_def ';' | '''SENSITIVITY''' ''<identifier>'' ''';'''
 
+
sensitivities = sensitivity_def | sensitivities sensitivity_def
+
 
+
sensitivity_def = '''SENSITIVITY''' ''<identifier>'' alias_def ';' | '''SENSITIVITY''' ''<identifier>'' ';'
+
  
 
alias_def = '''ALIAS''' names
 
alias_def = '''ALIAS''' names
  
dominance = '''DOMINANCE''' ''<identifier>'' | '''DOMINANCE''' '''{''' identifier_list '''}'''  
+
dominance = '''DOMINANCE''' ''<identifier>'' | '''DOMINANCE''' '''{''' ''<identifier>'' + '''}'''  
  
categories = category_def | categories category_def
+
category_def = '''CATEGORY''' ''<identifier>'' alias_def ';' | '''CATEGORY''' ''<identifier>'' ''';'''
  
category_def = '''CATEGORY''' ''<identifier>'' alias_def ';' | '''CATEGORY''' ''<identifier>'' ';'
+
level_def = '''LEVEL''' ''<identifier>'' ':' id_comma_list ';' | '''LEVEL''' ''<identifier>'' ''';'''  
  
levels = level_def | levels level_def
+
mlspolicy_decl = '''MLSCONSTRAIN''' names names cexpr ';' | '''MLSVALIDATETRANS''' names cexpr ''';'''
 
+
level_def = '''LEVEL''' ''<identifier>'' ':' id_comma_list ';' | '''LEVEL''' ''<identifier>'' ';'
+
 
+
mlspolicy = mlspolicy_decl | mlspolicy mlspolicy_decl
+
 
+
mlspolicy_decl = mlsconstraint_def | mlsvalidatetrans_def
+
 
+
mlsconstraint_def = '''MLSCONSTRAIN''' names names cexpr ';'
+
 
+
mlsvalidatetrans_def = '''MLSVALIDATETRANS''' names cexpr ';'
+
 
+
bool_val = '''CTRUE''' | '''CFALSE'''
+
 
+
cond_pol_list = cond_pol_list cond_rule_def  | /* empty */
+
 
+
cond_rule_def = cond_transition_def | cond_te_avtab_def | require_block
+
 
+
cond_transition_def = '''TYPE_TRANSITION''' names names ':' names ''<identifier>'' ';' | '''TYPE_MEMBER''' names names ':' names ''<identifier>'' ';' | '''TYPE_CHANGE''' names names ':' names ''<identifier>'' ';'
+
 
+
cond_te_avtab_def = '''ALLOW''' names names ''':''' names names  ''';''' | '''AUDITALLOW''' names names ''':''' names names ''';''' | '''AUDITDENY''' names names ''':''' names names ''';''' | '''DONTAUDIT''' names names ''':''' names names ''';'''
+
  
 
transition_def = '''TYPE_TRANSITION''' names names ''':''' names ''<identifier>'' ''';''' | '''TYPE_MEMBER''' names names ''':''' names ''<identifier>'' ''';''' | '''TYPE_CHANGE''' names names ''':''' names ''<identifier>'' ''';'''
 
transition_def = '''TYPE_TRANSITION''' names names ''':''' names ''<identifier>'' ''';''' | '''TYPE_MEMBER''' names names ''':''' names ''<identifier>'' ''';''' | '''TYPE_CHANGE''' names names ''':''' names ''<identifier>'' ''';'''
Line 140: Line 150:
 
range_trans_def = '''RANGE_TRANSITION''' names names mls_range_def ''';''' | '''RANGE_TRANSITION''' names names ''':''' names mls_range_def ''';'''  
 
range_trans_def = '''RANGE_TRANSITION''' names names mls_range_def ''';''' | '''RANGE_TRANSITION''' names names ''':''' names mls_range_def ''';'''  
  
role_type_def = '''ROLE''' ''<identifier>'' '''TYPES''' names ''';''' | '''ROLE''' ''<identifier>''';'
+
----
 
+
role_dominance = '''DOMINANCE''' '''{''' roles '''}'''
+
 
+
role_trans_def = '''ROLE_TRANSITION''' names names ''<identifier>'' ''';'''
+
 
+
role_allow_def = '''ALLOW''' names names ''';'''
+
 
+
roles = role_def | roles role_def
+
 
+
role_def = '''ROLE''' ''<identifier>''_push ''';''' | '''ROLE''' ''<identifier>''_push '''{''' roles '''}'''
+
  
 
cexpr = '(' cexpr ')' | '''NOT''' cexpr | cexpr '''AND''' cexpr | cexpr '''OR''' cexpr | cexpr_prim
 
cexpr = '(' cexpr ')' | '''NOT''' cexpr | cexpr '''AND''' cexpr | cexpr '''OR''' cexpr | cexpr_prim
Line 160: Line 160:
 
role_mls_op = op | '''DOM''' | '''DOMBY''' | '''INCOMP'''  
 
role_mls_op = op | '''DOM''' | '''DOMBY''' | '''INCOMP'''  
  
----
+
== token definations ==
  
fs_context_def = '''FSCON''' number number security_context_def security_context_def
+
names_push = ''<identifier>'' | '''{''' identifier_list_push '''}''' | '''*''' | '''~''' ''<identifier>'' | '''~''' '''{''' identifier_list_push '''}'''
  
port_context_def = '''PORTCON''' ''<identifier>'' number security_context_def | '''PORTCON''' ''<identifier>'' number '-' number security_context_def
+
identifier_list_push = ''<identifier>'' | identifier_list_push ''<identifier>''
 
+
netif_context_def = '''NETIFCON''' ''<identifier>'' security_context_def security_context_def
+
 
+
node_context_def = '''NODECON''' ''<ipv4_addr>'' ''<ipv4_addr>'' security_context_def | '''NODECON''' ''<ipv6_addr>'' ''<ipv6_addr>'' security_context_def
+
 
+
fs_use_def = '''FSUSEXATTR''' ''<identifier>'' security_context_def ''';''' | '''FSUSETASK''' ''<identifier>'' security_context_def ''';''' | '''FSUSETRANS''' ''<identifier>'' security_context_def ''';'''
+
 
+
genfs_context_def = '''GENFSCON''' ''<identifier>'' path '-' ''<identifier>'' security_context_def | '''GENFSCON''' ''<identifier>'' path '-' '-'  security_context_def | '''GENFSCON''' ''<identifier>'' path security_context_def
+
 
+
security_context_def = ''<identifier>'' ''':''' ''<identifier>'' ''':''' ''<identifier>'' [''':''' mls_range_def]
+
 
+
----
+
 
+
mls_range_def = mls_level_def '-' mls_level_def | mls_level_def
+
 
+
mls_level_def = ''<identifier>'' ''':''' id_comma_list | ''<identifier>''
+
 
+
id_comma_list = ''<identifier>'' | id_comma_list ',' ''<identifier>''
+
 
+
----
+
 
+
names_push = identifier_push | '''{''' identifier_list_push '''}''' | '''*''' | '''~''' identifier_push | '''~''' '''{''' identifier_list_push '''}'''
+
 
+
identifier_list_push = identifier_push | identifier_list_push identifier_push
+
 
+
identifier_push = IDENTIFIER
+
 
+
identifier_list = identifier | identifier_list identifier
+
  
 
nested_id_set = '''{''' nested_id_list '''}'''
 
nested_id_set = '''{''' nested_id_list '''}'''
Line 199: Line 171:
  
 
nested_id_element = identifier | '-'  identifier | nested_id_set
 
nested_id_element = identifier | '-'  identifier | nested_id_set
 
identifier = IDENTIFIER
 
 
path = PATH
 
 
number = NUMBER
 
 
policycap_def = POLICYCAP identifier ''';'''
 
 
version_identifier = VERSION_IDENTIFIER
 
 
require_class = CLASS identifier names
 
 
require_decl_def = ROLE | TYPE | ATTRIBUTE | USER | BOOL | SENSITIVITY | CATEGORY
 
 
require_id_list = identifier | require_id_list ',' identifier
 

Latest revision as of 05:41, 9 November 2008

This is my attempt at documenting the policy grammar that is accepted by checkpolicy. The grammar was taken directly from the bison input file and edited to make it more readable for the wiki system.

Comments start with a # character and continue to the end of the line.

Keywords can be in all uppercase or all lowercase.

Convention followed in this document: Plain text is used for non-terminals. Basically it means that there is a defination of the thing else where. When a non-terminal is used on the right hand side of a grammar rule there should be some rule in the file with that non-terminal on the left hand side. Items in bold are literal, they must appear in the policy file exactly as written. Items in italics are used for things that can be replaced by some user specified text. They will also be surrounded with < and > signs to make them clearly different from keywords.

Any item in [ square brackets ] is an optional item. Items with a * after them can be repeated zero or more times. Items with a + after them can be repeated one or more times. Parenthesis are used to group items that can be repeated. Vertical lines | are used to indicate alternatives.

A file must contain either a base_policy or a module_policy.

[edit] base policy

base_policy = class_def+ initial_sid_def+ access_vectors [mls] te_rbac user_def+ [constraint_decl+] initial_sid_context_def+ [fs_context_def+] [fs_use_def+] [genfs_context_def+] [port_context_def+] [netif_context_def+] [node_context_def+]

class_def = CLASS <identifier>

initial_sid_def = SID <identifier>

access_vectors = [common_perms_def +] av_perms_def+

av_perms_def = CLASS <identifier> { <identifier> + } | CLASS <identifier> INHERITS <identifier> | CLASS <identifier> INHERITS <identifier> { <identifier> + }

initial_sid_context_def = SID <identifier> security_context_def

constraint_decl = constraint_def | validatetrans_def

constraint_def = CONSTRAIN names names cexpr ;

validatetrans_def = VALIDATETRANS names cexpr ;


fs_context_def = FSCON <number> <number> security_context_def security_context_def

port_context_def = PORTCON <identifier> <number> security_context_def | PORTCON <identifier> <number> '-' <number> security_context_def

netif_context_def = NETIFCON <identifier> security_context_def security_context_def

node_context_def = NODECON <ipv4_addr> <ipv4_addr> security_context_def | NODECON <ipv6_addr> <ipv6_addr> security_context_def

fs_use_def = FSUSEXATTR <identifier> security_context_def ; | FSUSETASK <identifier> security_context_def ; | FSUSETRANS <identifier> security_context_def ;

genfs_context_def = GENFSCON <identifier> <path> '-' <identifier> security_context_def | GENFSCON <identifier> <path> '-' '-' security_context_def | GENFSCON <identifier> <path> security_context_def

security_context_def = <identifier> : <identifier> : <identifier> [: mls_range_def]


mls_range_def = mls_level_def '-' mls_level_def | mls_level_def

mls_level_def = <identifier> : id_comma_list | <identifier>

id_comma_list = <identifier> | id_comma_list ',' <identifier>

[edit] module policy

module_policy = MODULE <identifier> <version_identifier> ; avrules_block

avrules_block = avrule_decl+ user_def*

avrule_decl = rbac_decl | te_decl | cond_stmt_def | require_block | optional_block | ;

user_def = USER <identifier> ROLES names [LEVEL mls_level_def RANGE mls_range_def] ;


rbac_decl = role_type_def | role_dominance | role_trans_def | role_allow_def

role_type_def = ROLE' <identifier> TYPES names ; | ROLE <identifier>;'

role_dominance = DOMINANCE { role_def+ }

role_allow_def = ALLOW names names ;

role_trans_def = ROLE_TRANSITION names names <identifier> ;

role_def = ROLE <identifier> ; | ROLE <identifier> { role_def+ }

te_decl = ATTRIBUTE <identifier> ; | type_def | TYPEALIAS <identifier> alias_def ; | TYPEATTRIBUTE <identifier> id_comma_list ; | BOOL <identifier> (CTRUE | CFALSE) ; | transition_def | range_trans_def | te_avtab_def | PERMISSIVE <identifier> ;

te_rbac = ( te_decl | rbac_decl | cond_stmt_def | optional_block | POLICYCAP <identifier> ; | ; )+

te_avtab_def = ALLOW names names : names names ; | AUDITALLOW names names : names names ; | AUDITDENY names names : names names ; | DONTAUDIT names names : names names ; | NEVERALLOW names names : names names ;


require_block = REQUIRE { require_decl+ }

require_decl = CLASS <identifier> names ; | (ROLE | TYPE | ATTRIBUTE | USER | BOOL | SENSITIVITY | CATEGORY) <identifier> (, <identifier> )* ;


optional_block = OPTIONAL { avrules_block } [ ELSE { avrules_block } ]


cond_stmt_def = IF cond_expr { cond_rule_def* } [ ELSE { cond_rule_def* } ]

cond_expr = '(' cond_expr ')' | NOT cond_expr | cond_expr AND cond_expr | cond_expr OR cond_expr | cond_expr XOR cond_expr | cond_expr EQUALS cond_expr | cond_expr NOTEQUAL cond_expr | <identifier>

cond_rule_def = cond_transition_def | cond_te_avtab_def | require_block

cond_transition_def = TYPE_TRANSITION names names ':' names <identifier> ';' | TYPE_MEMBER names names ':' names <identifier> ';' | TYPE_CHANGE names names ':' names <identifier> ';'

cond_te_avtab_def = ALLOW names names : names names ; | AUDITALLOW names names : names names ; | AUDITDENY names names : names names ; | DONTAUDIT names names : names names ;


type_def = TYPE <identifier> alias_def [',' id_comma_list] ; | TYPE <identifier> [',' id_comma_list] ;


names = <identifier> | nested_id_set | * | ~ <identifier> | ~ nested_id_set | <identifier> - <identifier>


common_perms_def = COMMON <identifier> { <identifier> + }

mls = sensitivity_def+ dominance [category_def+] level_def+ mlspolicy_decl+

sensitivity_def = SENSITIVITY <identifier> alias_def ';' | SENSITIVITY <identifier> ;

alias_def = ALIAS names

dominance = DOMINANCE <identifier> | DOMINANCE { <identifier> + }

category_def = CATEGORY <identifier> alias_def ';' | CATEGORY <identifier> ;

level_def = LEVEL <identifier> ':' id_comma_list ';' | LEVEL <identifier> ;

mlspolicy_decl = MLSCONSTRAIN names names cexpr ';' | MLSVALIDATETRANS names cexpr ;

transition_def = TYPE_TRANSITION names names : names <identifier> ; | TYPE_MEMBER names names : names <identifier> ; | TYPE_CHANGE names names : names <identifier> ;

range_trans_def = RANGE_TRANSITION names names mls_range_def ; | RANGE_TRANSITION names names : names mls_range_def ;


cexpr = '(' cexpr ')' | NOT cexpr | cexpr AND cexpr | cexpr OR cexpr | cexpr_prim

cexpr_prim = U1 op U2 | R1 role_mls_op R2 | T1 op T2 | U1 op names_push | U2 op names_push | U3 op names_push | R1 op names_push | R2 op names_push | R3 op names_push | T1 op names_push | T2 op names_push | T3 op names_push | SAMEUSER | SOURCE ROLE names_push | TARGET ROLE names_push | ROLE role_mls_op | SOURCE TYPE names_push | TARGET TYPE names_push | L1 role_mls_op L2 | L1 role_mls_op H2 | H1 role_mls_op L2 | H1 role_mls_op H2 | L1 role_mls_op H1 | L2 role_mls_op H2

op = EQUALS | NOTEQUAL

role_mls_op = op | DOM | DOMBY | INCOMP

[edit] token definations

names_push = <identifier> | { identifier_list_push } | * | ~ <identifier> | ~ { identifier_list_push }

identifier_list_push = <identifier> | identifier_list_push <identifier>

nested_id_set = { nested_id_list }

nested_id_list = nested_id_element | nested_id_list nested_id_element

nested_id_element = identifier | '-' identifier | nested_id_set