CIL's in-statement is resolved before block inheritance. This has
the advantage of allowing an in-statement to add rules to a base
block (say for a new permission) and having those rules also be
added everywhere that base block is inherited. But the disadvantage
of this behavior is that it is not possible to use an in-statement
on a block that is inherited for the simple reason that that block
does not exist when the in-statment is resolved.
Change the syntax of the in-statement to allow specifying whether
the rules should be added before or after inheritance. If neither
is specified, then the behavior remains the same. All current
in-statements will work as before.
Either the old syntax
(in container_id
cil_statement
...
)
or the new syntax
(in before|after container_id
cil_statement
...
)
may be used for in-statements. But only "(in after ..." will have
the new behavior. Using "(in before ..." will give the same
behavior as before.
Macro Example
;
(block b1
(macro m1 ((type ARG1))
(allow ARG1 self (C1 (P1a)))
)
)
(in after b1.m1
(allow ARG1 self (C1 (P1c)))
)
(type t1a)
(call b1.m1 (t1a))
(blockinherit b1)
(in after m1
(allow ARG1 self (C1 (P1b)))
)
(type t1b)
(call m1 (t1b))
;
This results in the following rules:
(allow t1a self (C1 (P1a)))
(allow t1a self (C1 (P1c)))
(allow t1b self (C1 (P1a)))
(allow t1b self (C1 (P1b)))
Block Example
;
(block b2
(block b
(type ta)
(allow ta self (C2 (P2a)))
)
)
(in before b2.b
(type tb)
(allow tb self (C2 (P2b)))
)
(block c2
(blockinherit b2)
(in after b
(type tc)
(allow tc self (C2 (P2c)))
)
)
;
This results in the following rules:
(allow b2.b.ta self (C2 (P2a)))
(allow b2.b.tb self (C2 (P2b)))
(allow c2.b.ta self (C2 (P2a)))
(allow c2.b.tb self (C2 (P2b)))
(allow c2.b.tc self (C2 (P2c)))
Using in-statements on optionals also works as expected.
One additional change is that blockabstract and blockinherit rules
are not allowed when using an after in-statement. This is because
both of those are resolved before an after in-statement would be
resolved.
Signed-off-by: James Carter <jwcart2@xxxxxxxxx>
---
libsepol/cil/src/cil.c | 5 +++
libsepol/cil/src/cil_build_ast.c | 31 +++++++++++++++++--
libsepol/cil/src/cil_internal.h | 6 +++-
libsepol/cil/src/cil_resolve_ast.c | 49 +++++++++++++++++++++---------
4 files changed, 72 insertions(+), 19 deletions(-)
diff --git a/libsepol/cil/src/cil.c b/libsepol/cil/src/cil.c
index d24c81c8..672342b5 100644
--- a/libsepol/cil/src/cil.c
+++ b/libsepol/cil/src/cil.c
@@ -142,6 +142,8 @@ char *CIL_KEY_HANDLEUNKNOWN_DENY;
char *CIL_KEY_HANDLEUNKNOWN_REJECT;
char *CIL_KEY_MACRO;
char *CIL_KEY_IN;
+char *CIL_KEY_IN_BEFORE;
+char *CIL_KEY_IN_AFTER;
char *CIL_KEY_MLS;
char *CIL_KEY_DEFAULTRANGE;
char *CIL_KEY_BLOCKINHERIT;
@@ -353,6 +355,8 @@ static void cil_init_keys(void)
CIL_KEY_DEFAULTTYPE = cil_strpool_add("defaulttype");
CIL_KEY_MACRO = cil_strpool_add("macro");
CIL_KEY_IN = cil_strpool_add("in");
+ CIL_KEY_IN_BEFORE = cil_strpool_add("before");
+ CIL_KEY_IN_AFTER = cil_strpool_add("after");
CIL_KEY_MLS = cil_strpool_add("mls");
CIL_KEY_DEFAULTRANGE = cil_strpool_add("defaultrange");
CIL_KEY_GLOB = cil_strpool_add("*");
@@ -2121,6 +2125,7 @@ void cil_in_init(struct cil_in **in)
*in = cil_malloc(sizeof(**in));
cil_symtab_array_init((*in)->symtab, cil_sym_sizes[CIL_SYM_ARRAY_IN]);
+ (*in)->is_after = CIL_FALSE;
(*in)->block_str = NULL;
}
diff --git a/libsepol/cil/src/cil_build_ast.c b/libsepol/cil/src/cil_build_ast.c
index 9da90883..4a87e212 100644
--- a/libsepol/cil/src/cil_build_ast.c
+++ b/libsepol/cil/src/cil_build_ast.c
@@ -380,7 +380,8 @@ int cil_gen_in(struct cil_db *db, struct cil_tree_node *parse_current, struct ci
enum cil_syntax syntax[] = {
CIL_SYN_STRING,
CIL_SYN_STRING,
- CIL_SYN_N_LISTS,
+ CIL_SYN_STRING | CIL_SYN_N_LISTS,
+ CIL_SYN_N_LISTS | CIL_SYN_END,
CIL_SYN_END
};
int syntax_len = sizeof(syntax)/sizeof(*syntax);
@@ -403,14 +404,29 @@ int cil_gen_in(struct cil_db *db, struct cil_tree_node *parse_current, struct ci
cil_in_init(&in);
- in->block_str = parse_current->next->data;
+ if (parse_current->next->next->data) {
+ char *is_after_str = parse_current->next->data;
+ if (is_after_str == CIL_KEY_IN_BEFORE) {
+ in->is_after = CIL_FALSE;
+ } else if (is_after_str == CIL_KEY_IN_AFTER) {
+ in->is_after = CIL_TRUE;
+ } else {
+ cil_log(CIL_ERR, "Value must be either \'before\' or \'after\'\n");
+ rc = SEPOL_ERR;
+ goto exit;
+ }
+ in->block_str = parse_current->next->next->data;
+ } else {
+ in->is_after = CIL_FALSE;
+ in->block_str = parse_current->next->data;
+ }
ast_node->data = in;
ast_node->flavor = CIL_IN;
return SEPOL_OK;
exit:
- cil_tree_log(parse_current, CIL_ERR, "Bad in statement");
+ cil_tree_log(parse_current, CIL_ERR, "Bad in-statement");
cil_destroy_in(in);
return rc;
}
@@ -6136,12 +6152,21 @@ int __cil_build_ast_node_helper(struct cil_tree_node *parse_current, uint32_t *f
}
if (in != NULL) {
+ struct cil_in *in_block = in->data;
if (parse_current->data == CIL_KEY_TUNABLE ||
parse_current->data == CIL_KEY_IN) {
rc = SEPOL_ERR;
cil_tree_log(parse_current, CIL_ERR, "%s is not allowed in in-statement", (char *)parse_current->data);
goto exit;
}
+ if (in_block->is_after == CIL_TRUE) {
+ if (parse_current->data == CIL_KEY_BLOCKINHERIT ||
+ parse_current->data == CIL_KEY_BLOCKABSTRACT) {
+ rc = SEPOL_ERR;
+ cil_tree_log(parse_current, CIL_ERR, "%s is not allowed in an after in-statement", (char *)parse_current->data);
+ goto exit;
+ }
+ }
}
if (macro != NULL) {
diff --git a/libsepol/cil/src/cil_internal.h b/libsepol/cil/src/cil_internal.h
index 98e303d1..d33c66bc 100644
--- a/libsepol/cil/src/cil_internal.h
+++ b/libsepol/cil/src/cil_internal.h
@@ -56,10 +56,11 @@ enum cil_pass {
CIL_PASS_INIT = 0,
CIL_PASS_TIF,
- CIL_PASS_IN,
+ CIL_PASS_IN_BEFORE,
CIL_PASS_BLKIN_LINK,
CIL_PASS_BLKIN_COPY,
CIL_PASS_BLKABS,
+ CIL_PASS_IN_AFTER,
CIL_PASS_CALL1,
CIL_PASS_CALL2,
CIL_PASS_ALIAS1,
@@ -158,6 +159,8 @@ extern char *CIL_KEY_HANDLEUNKNOWN_DENY;
extern char *CIL_KEY_HANDLEUNKNOWN_REJECT;
extern char *CIL_KEY_MACRO;
extern char *CIL_KEY_IN;
+extern char *CIL_KEY_IN_BEFORE;
+extern char *CIL_KEY_IN_AFTER;
extern char *CIL_KEY_MLS;
extern char *CIL_KEY_DEFAULTRANGE;
extern char *CIL_KEY_BLOCKINHERIT;
@@ -355,6 +358,7 @@ struct cil_blockabstract {
struct cil_in {
symtab_t symtab[CIL_SYM_NUM];
+ int is_after;
char *block_str;
};
diff --git a/libsepol/cil/src/cil_resolve_ast.c b/libsepol/cil/src/cil_resolve_ast.c
index 18007324..77e0d402 100644
--- a/libsepol/cil/src/cil_resolve_ast.c
+++ b/libsepol/cil/src/cil_resolve_ast.c
@@ -62,7 +62,8 @@ struct cil_args_resolve {
struct cil_list *unordered_classorder_lists;
struct cil_list *catorder_lists;
struct cil_list *sensitivityorder_lists;
- struct cil_list *in_list;
+ struct cil_list *in_list_before;
+ struct cil_list *in_list_after;
struct cil_stack *disabled_optionals;
};
@@ -2449,10 +2450,8 @@ exit:
return rc;
}
-int cil_resolve_in_list(void *extra_args)
+int cil_resolve_in_list(struct cil_list *in_list, void *extra_args)
{
- struct cil_args_resolve *args = extra_args;
- struct cil_list *ins = args->in_list;
struct cil_list_item *curr = NULL;
struct cil_tree_node *node = NULL;
struct cil_tree_node *last_failed_node = NULL;
@@ -2466,7 +2465,7 @@ int cil_resolve_in_list(void *extra_args)
resolved = 0;
unresolved = 0;
- cil_list_for_each(curr, ins) {
+ cil_list_for_each(curr, in_list) {
if (curr->flavor != CIL_NODE) {
continue;
}
@@ -3590,12 +3589,10 @@ int __cil_resolve_ast_node(struct cil_tree_node *node, void *extra_args)
int rc = SEPOL_OK;
struct cil_args_resolve *args = extra_args;
enum cil_pass pass = 0;
- struct cil_list *ins;
if (node == NULL || args == NULL) {
goto exit;
}
- ins = args->in_list;
pass = args->pass;
switch (pass) {
@@ -3604,11 +3601,14 @@ int __cil_resolve_ast_node(struct cil_tree_node *node, void *extra_args)
rc = cil_resolve_tunif(node, args);
}
break;
- case CIL_PASS_IN:
+ case CIL_PASS_IN_BEFORE:
if (node->flavor == CIL_IN) {
// due to ordering issues, in statements are just gathered here and
// resolved together in cil_resolve_in_list once all are found
- cil_list_prepend(ins, CIL_NODE, node);
+ struct cil_in *in = node->data;
+ if (in->is_after == CIL_FALSE) {
+ cil_list_prepend(args->in_list_before, CIL_NODE, node);
+ }
}
break;
case CIL_PASS_BLKIN_LINK:
@@ -3626,6 +3626,16 @@ int __cil_resolve_ast_node(struct cil_tree_node *node, void *extra_args)
rc = cil_resolve_blockabstract(node, args);
}
break;
+ case CIL_PASS_IN_AFTER:
+ if (node->flavor == CIL_IN) {
+ // due to ordering issues, in statements are just gathered here and
+ // resolved together in cil_resolve_in_list once all are found
+ struct cil_in *in = node->data;
+ if (in->is_after == CIL_TRUE) {
+ cil_list_prepend(args->in_list_after, CIL_NODE, node);
+ }
+ }
+ break;
case CIL_PASS_CALL1:
if (node->flavor == CIL_CALL && args->macro == NULL) {
rc = cil_resolve_call(node, args);
@@ -4073,7 +4083,8 @@ int cil_resolve_ast(struct cil_db *db, struct cil_tree_node *current)
extra_args.unordered_classorder_lists = NULL;
extra_args.catorder_lists = NULL;
extra_args.sensitivityorder_lists = NULL;
- extra_args.in_list = NULL;
+ extra_args.in_list_before = NULL;
+ extra_args.in_list_after = NULL;
extra_args.disabled_optionals = NULL;
cil_list_init(&extra_args.to_destroy, CIL_NODE);
@@ -4082,7 +4093,8 @@ int cil_resolve_ast(struct cil_db *db, struct cil_tree_node *current)
cil_list_init(&extra_args.unordered_classorder_lists, CIL_LIST_ITEM);
cil_list_init(&extra_args.catorder_lists, CIL_LIST_ITEM);
cil_list_init(&extra_args.sensitivityorder_lists, CIL_LIST_ITEM);
- cil_list_init(&extra_args.in_list, CIL_IN);
+ cil_list_init(&extra_args.in_list_before, CIL_IN);
+ cil_list_init(&extra_args.in_list_after, CIL_IN);
cil_stack_init(&extra_args.disabled_optionals);
for (pass = CIL_PASS_TIF; pass < CIL_PASS_NUM; pass++) {
@@ -4093,12 +4105,18 @@ int cil_resolve_ast(struct cil_db *db, struct cil_tree_node *current)
goto exit;
}
- if (pass == CIL_PASS_IN) {
- rc = cil_resolve_in_list(&extra_args);
+ if (pass == CIL_PASS_IN_BEFORE) {
+ rc = cil_resolve_in_list(extra_args.in_list_before, &extra_args);
+ if (rc != SEPOL_OK) {
+ goto exit;
+ }
+ cil_list_destroy(&extra_args.in_list_before, CIL_FALSE);
+ } else if (pass == CIL_PASS_IN_AFTER) {
+ rc = cil_resolve_in_list(extra_args.in_list_after, &extra_args);
if (rc != SEPOL_OK) {
goto exit;
}
- cil_list_destroy(&extra_args.in_list, CIL_FALSE);
+ cil_list_destroy(&extra_args.in_list_after, CIL_FALSE);
}
if (pass == CIL_PASS_BLKIN_LINK) {
@@ -4217,7 +4235,8 @@ exit:
__cil_ordered_lists_destroy(&extra_args.sensitivityorder_lists);
__cil_ordered_lists_destroy(&extra_args.unordered_classorder_lists);
cil_list_destroy(&extra_args.to_destroy, CIL_FALSE);
- cil_list_destroy(&extra_args.in_list, CIL_FALSE);
+ cil_list_destroy(&extra_args.in_list_before, CIL_FALSE);
+ cil_list_destroy(&extra_args.in_list_after, CIL_FALSE);
cil_stack_destroy(&extra_args.disabled_optionals);
return rc;
--
2.31.1
