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Rewrite sepolicy.c in C++

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This commit is contained in:
topjohnwu 2020-05-23 00:18:25 -07:00
parent 0236ab887e
commit f392ade78d
11 changed files with 714 additions and 701 deletions
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8
native/jni/Android.mk
View File

@ -63,12 +63,11 @@ LOCAL_SRC_FILES := \
init/getinfo.cpp \
init/twostage.cpp \
core/socket.cpp \
magiskpolicy/api.cpp \
magiskpolicy/sepolicy.cpp \
magiskpolicy/magiskpolicy.cpp \
magiskpolicy/rules.cpp \
magiskpolicy/policydb.cpp \
magiskpolicy/statement.cpp \
magiskpolicy/sepolicy.c \
magiskboot/pattern.cpp
LOCAL_LDFLAGS := -static
@ -108,12 +107,11 @@ LOCAL_C_INCLUDES := jni/include
LOCAL_SRC_FILES := \
core/applet_stub.cpp \
magiskpolicy/api.cpp \
magiskpolicy/sepolicy.cpp \
magiskpolicy/magiskpolicy.cpp \
magiskpolicy/rules.cpp \
magiskpolicy/policydb.cpp \
magiskpolicy/statement.cpp \
magiskpolicy/sepolicy.c
magiskpolicy/statement.cpp
LOCAL_CFLAGS := -DAPPLET_STUB_MAIN=magiskpolicy_main
LOCAL_LDFLAGS := -static

5
native/jni/include/magiskpolicy.hpp
View File

@ -41,7 +41,7 @@ public:
int dontauditxperm(c_str src, c_str tgt, c_str cls, c_str range);
// Type rules
int type_transition(c_str src, c_str tgt, c_str cls, c_str def, c_str obj = nullptr);
int type_transition(c_str s, c_str t, c_str c, c_str d, c_str o = nullptr);
int type_change(c_str src, c_str tgt, c_str cls, c_str def);
int type_member(c_str src, c_str tgt, c_str cls, c_str def);
@ -50,8 +50,7 @@ public:
// Magisk
void magisk_rules();
void allow_su_client(c_str type);
private:
protected:
policydb *db;
};

90
native/jni/magiskpolicy/api.cpp
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@ -1,90 +0,0 @@
#include <magiskpolicy.hpp>
#include "sepolicy.h"
//#define vprint(fmt, ...) printf(fmt, __VA_ARGS__)
#define vprint(...)
int sepolicy::allow(const char *s, const char *t, const char *c, const char *p) {
vprint("allow %s %s %s %s\n", s, t, c, p);
return add_rule(db, s, t, c, p, AVTAB_ALLOWED, 0);
}
int sepolicy::deny(const char *s, const char *t, const char *c, const char *p) {
vprint("deny %s %s %s %s\n", s, t, c, p);
return add_rule(db, s, t, c, p, AVTAB_ALLOWED, 1);
}
int sepolicy::auditallow(const char *s, const char *t, const char *c, const char *p) {
vprint("auditallow %s %s %s %s\n", s, t, c, p);
return add_rule(db, s, t, c, p, AVTAB_AUDITALLOW, 0);
}
int sepolicy::dontaudit(const char *s, const char *t, const char *c, const char *p) {
vprint("dontaudit %s %s %s %s\n", s, t, c, p);
return add_rule(db, s, t, c, p, AVTAB_AUDITDENY, 1);
}
int sepolicy::allowxperm(const char *s, const char *t, const char *c, const char *range) {
vprint("allowxperm %s %s %s %s\n", s, t, c, range);
return add_xperm_rule(db, s, t, c, range, AVTAB_XPERMS_ALLOWED, 0);
}
int sepolicy::auditallowxperm(const char *s, const char *t, const char *c, const char *range) {
vprint("auditallowxperm %s %s %s %s\n", s, t, c, range);
return add_xperm_rule(db, s, t, c, range, AVTAB_XPERMS_AUDITALLOW, 0);
}
int sepolicy::dontauditxperm(const char *s, const char *t, const char *c, const char *range) {
vprint("dontauditxperm %s %s %s %s\n", s, t, c, range);
return add_xperm_rule(db, s, t, c, range, AVTAB_XPERMS_DONTAUDIT, 0);
}
int sepolicy::type_change(const char *s, const char *t, const char *c, const char *d) {
vprint("type_change %s %s %s %s\n", s, t, c, d);
return add_type_rule(db, s, t, c, d, AVTAB_CHANGE);
}
int sepolicy::type_member(const char *s, const char *t, const char *c, const char *d) {
vprint("type_member %s %s %s %s\n", s, t, c, d);
return add_type_rule(db, s, t, c, d, AVTAB_MEMBER);
}
int sepolicy::type_transition(const char *src, const char *tgt, const char *cls, const char *def, const char *obj) {
if (obj) {
vprint("type_transition %s %s %s %s\n", src, tgt, cls, def);
return add_type_rule(db, src, tgt, cls, def, AVTAB_TRANSITION);
} else {
vprint("type_transition %s %s %s %s %s\n", src, tgt, cls, def, obj);
return add_filename_trans(db, src, tgt, cls, def, obj);
}
}
int sepolicy::permissive(const char *s) {
vprint("permissive %s\n", s);
return set_domain_state(db, s, 1);
}
int sepolicy::enforce(const char *s) {
vprint("enforce %s\n", s);
return set_domain_state(db, s, 0);
}
int sepolicy::create(const char *s) {
vprint("create %s\n", s);
return create_domain(db, s);
}
int sepolicy::typeattribute(const char *type, const char *attr) {
vprint("typeattribute %s %s\n", type, attr);
return add_typeattribute(db, type, attr);
}
int sepolicy::genfscon(const char *fs_name, const char *path, const char *ctx) {
vprint("genfscon %s %s %s\n", fs_name, path, ctx);
return add_genfscon(db, fs_name, path, ctx);
}
int sepolicy::exists(const char *source) {
return hashtab_search(db->p_types.table, source) != nullptr;
}

2
native/jni/magiskpolicy/magiskpolicy.cpp
View File

@ -6,7 +6,7 @@
#include <flags.h>
#include <magiskpolicy.hpp>
#include "sepolicy.h"
#include "sepolicy.hpp"
using namespace std::literals;

2
native/jni/magiskpolicy/policydb.cpp
View File

@ -10,7 +10,7 @@
#include <stream.hpp>
#include <magiskpolicy.hpp>
#include "sepolicy.h"
#include "sepolicy.hpp"
#define SHALEN 64
static bool cmp_sha256(const char *a, const char *b) {

23
native/jni/magiskpolicy/rules.cpp
View File

@ -1,10 +1,12 @@
#include <initializer_list>
#include <logging.hpp>
#include <flags.h>
#include <magiskpolicy.hpp>
#include "sepolicy.h"
#include "sepolicy.hpp"
void sepolicy::allow_su_client(const char *type) {
void sepol_impl::allow_su_client(const char *type) {
if (!exists(type))
return;
allow(type, SEPOL_PROC_DOMAIN, "unix_stream_socket", "connectto");
@ -78,16 +80,11 @@ void sepolicy::magisk_rules() {
allow(SEPOL_PROC_DOMAIN, "kernel", "security", "load_policy");
// Allow these processes to access MagiskSU
allow_su_client("init");
allow_su_client("shell");
allow_su_client("system_app");
allow_su_client("priv_app");
allow_su_client("platform_app");
allow_su_client("untrusted_app");
allow_su_client("untrusted_app_25");
allow_su_client("untrusted_app_27");
allow_su_client("untrusted_app_29");
allow_su_client("update_engine");
std::initializer_list<const char *> clients {
"init", "shell", "system_app", "priv_app", "platform_app", "untrusted_app",
"untrusted_app_25", "untrusted_app_27", "untrusted_app_29", "update_engine" };
for (auto type : clients)
impl->allow_su_client(type);
// suRights
allow("servicemanager", SEPOL_PROC_DOMAIN, "dir", "search");
@ -199,7 +196,7 @@ void sepolicy::magisk_rules() {
#if 0
// Remove all dontaudit in debug mode
strip_dontaudit(db);
impl->strip_dontaudit();
#endif
log_cb.w = bak;

563
native/jni/magiskpolicy/sepolicy.c
View File

@ -1,563 +0,0 @@
#include <stdlib.h>
#include <sepol/policydb/expand.h>
#include <logging.hpp>
#include "sepolicy.h"
extern void *xmalloc(size_t size);
extern void *xcalloc(size_t nmemb, size_t size);
extern void *xrealloc(void *ptr, size_t size);
// Internal libsepol APIs
extern int policydb_index_decls(sepol_handle_t * handle, policydb_t * p);
extern int context_from_string(
sepol_handle_t * handle,
const policydb_t * policydb,
context_struct_t ** cptr,
const char *con_str, size_t con_str_len);
// Generic hash table traversal
#define hash_for_each(node_ptr, n_slots, table, block) \
for (int __i = 0; __i < (table)->n_slots; ++__i) { \
__typeof__(*(table)->node_ptr) node; \
__typeof__(node) __next; \
for (node = (table)->node_ptr[__i]; node; node = __next) { \
__next = node->next; \
block \
} \
}
// hashtab traversal
#define hashtab_for_each(hashtab, block) \
hash_for_each(htable, size, hashtab, block)
// avtab traversal
#define avtab_for_each(avtab, block) \
hash_for_each(htable, nslot, avtab, block)
static int set_attr(policydb_t *db, const char *type, int value) {
type_datum_t *attr = hashtab_search(db->p_types.table, type);
if (!attr || attr->flavor != TYPE_ATTRIB)
return -1;
if (ebitmap_set_bit(&db->type_attr_map[value - 1], attr->s.value - 1, 1))
return -1;
if (ebitmap_set_bit(&db->attr_type_map[attr->s.value - 1], value - 1, 1))
return -1;
return attr->s.value;
}
static void check_avtab_node(policydb_t *db, avtab_ptr_t node) {
int redundant = 0;
if (node->key.specified == AVTAB_AUDITDENY)
redundant = node->datum.data == ~0U;
else if (node->key.specified & AVTAB_XPERMS)
redundant = node->datum.xperms == NULL;
else
redundant = node->datum.data == 0U;
if (redundant)
avtab_remove_node(&db->te_avtab, node);
}
static avtab_ptr_t get_avtab_node(policydb_t *db, avtab_key_t *key, avtab_extended_perms_t *xperms) {
avtab_ptr_t node;
avtab_datum_t avdatum;
int match = 0;
/* AVTAB_XPERMS entries are not necessarily unique */
if (key->specified & AVTAB_XPERMS) {
node = avtab_search_node(&db->te_avtab, key);
while (node) {
if ((node->datum.xperms->specified == xperms->specified) &&
(node->datum.xperms->driver == xperms->driver)) {
match = 1;
break;
}
node = avtab_search_node_next(node, key->specified);
}
if (!match)
node = NULL;
} else {
node = avtab_search_node(&db->te_avtab, key);
}
if (!node) {
memset(&avdatum, 0, sizeof avdatum);
/*
* AUDITDENY, aka DONTAUDIT, are &= assigned, versus |= for
* others. Initialize the data accordingly.
*/
avdatum.data = key->specified == AVTAB_AUDITDENY ? ~0U : 0U;
/* this is used to get the node - insertion is actually unique */
node = avtab_insert_nonunique(&db->te_avtab, key, &avdatum);
}
return node;
}
static int add_avrule(policydb_t *db, avtab_key_t *key, int val, int not) {
avtab_ptr_t node = get_avtab_node(NULL, key, NULL);
if (not) {
if (val < 0)
node->datum.data = 0U;
else
node->datum.data &= ~(1U << (val - 1));
} else {
if (val < 0)
node->datum.data = ~0U;
else
node->datum.data |= 1U << (val - 1);
}
check_avtab_node(db, node);
return 0;
}
static int add_rule_auto(policydb_t *db, type_datum_t *src, type_datum_t *tgt, class_datum_t *cls,
perm_datum_t *perm, int effect, int not) {
avtab_key_t key;
int ret = 0;
if (src == NULL) {
hashtab_for_each(db->p_types.table, {
src = node->datum;
ret |= add_rule_auto(db, src, tgt, cls, perm, effect, not);
})
} else if (tgt == NULL) {
hashtab_for_each(db->p_types.table, {
tgt = node->datum;
ret |= add_rule_auto(db, src, tgt, cls, perm, effect, not);
})
} else if (cls == NULL) {
hashtab_for_each(db->p_classes.table, {
cls = node->datum;
ret |= add_rule_auto(db, src, tgt, cls, perm, effect, not);
})
} else {
key.source_type = src->s.value;
key.target_type = tgt->s.value;
key.target_class = cls->s.value;
key.specified = effect;
return add_avrule(db, &key, perm ? perm->s.value : -1, not);
}
return ret;
}
#define ioctl_driver(x) (x>>8 & 0xFF)
#define ioctl_func(x) (x & 0xFF)
static int add_avxrule(policydb_t *db, avtab_key_t *key, uint16_t low, uint16_t high, int not) {
avtab_datum_t *datum;
avtab_extended_perms_t xperms;
memset(&xperms, 0, sizeof(xperms));
if (ioctl_driver(low) != ioctl_driver(high)) {
xperms.specified = AVTAB_XPERMS_IOCTLDRIVER;
xperms.driver = 0;
} else {
xperms.specified = AVTAB_XPERMS_IOCTLFUNCTION;
xperms.driver = ioctl_driver(low);
}
if (xperms.specified == AVTAB_XPERMS_IOCTLDRIVER) {
for (int i = ioctl_driver(low); i <= ioctl_driver(high); ++i) {
if (not)
xperm_clear(i, xperms.perms);
else
xperm_set(i, xperms.perms);
}
} else {
for (int i = ioctl_func(low); i <= ioctl_func(high); ++i) {
if (not)
xperm_clear(i, xperms.perms);
else
xperm_set(i, xperms.perms);
}
}
datum = &get_avtab_node(db, key, &xperms)->datum;
if (datum->xperms == NULL)
datum->xperms = xmalloc(sizeof(xperms));
memcpy(datum->xperms, &xperms, sizeof(xperms));
return 0;
}
static int add_xperm_rule_auto(policydb_t *db, type_datum_t *src, type_datum_t *tgt,
class_datum_t *cls, uint16_t low, uint16_t high, int effect, int not) {
avtab_key_t key;
int ret = 0;
if (src == NULL) {
hashtab_for_each(db->p_types.table, {
src = node->datum;
ret |= add_xperm_rule_auto(db, src, tgt, cls, low, high, effect, not);
})
} else if (tgt == NULL) {
hashtab_for_each(db->p_types.table, {
tgt = node->datum;
ret |= add_xperm_rule_auto(db, src, tgt, cls, low, high, effect, not);
})
} else if (cls == NULL) {
hashtab_for_each(db->p_classes.table, {
cls = node->datum;
ret |= add_xperm_rule_auto(db, src, tgt, cls, low, high, effect, not);
})
} else {
key.source_type = src->s.value;
key.target_type = tgt->s.value;
key.target_class = cls->s.value;
key.specified = effect;
return add_avxrule(db, &key, low, high, not);
}
return ret;
}
int create_domain(policydb_t *db, const char *d) {
symtab_datum_t *src = hashtab_search(db->p_types.table, d);
if (src) {
LOGW("Domain %s already exists\n", d);
return 0;
}
type_datum_t *typedatum = xmalloc(sizeof(type_datum_t));
type_datum_init(typedatum);
typedatum->primary = 1;
typedatum->flavor = TYPE_TYPE;
uint32_t value = 0;
symtab_insert(db, SYM_TYPES, strdup(d), typedatum, SCOPE_DECL, 1, &value);
typedatum->s.value = value;
if (ebitmap_set_bit(&db->global->branch_list->declared.scope[SYM_TYPES], value - 1, 1)) {
return 1;
}
db->type_attr_map = xrealloc(db->type_attr_map, sizeof(ebitmap_t) * db->p_types.nprim);
db->attr_type_map = xrealloc(db->attr_type_map, sizeof(ebitmap_t) * db->p_types.nprim);
ebitmap_init(&db->type_attr_map[value-1]);
ebitmap_init(&db->attr_type_map[value-1]);
ebitmap_set_bit(&db->type_attr_map[value-1], value-1, 1);
src = hashtab_search(db->p_types.table, d);
if (!src)
return 1;
if (policydb_index_decls(NULL, db))
return 1;
if (policydb_index_classes(db))
return 1;
if (policydb_index_others(NULL, db, 0))
return 1;
// Add the domain to all roles
for (unsigned i = 0; i < db->p_roles.nprim; ++i) {
// Not sure all those three calls are needed
ebitmap_set_bit(&db->role_val_to_struct[i]->types.negset, value - 1, 0);
ebitmap_set_bit(&db->role_val_to_struct[i]->types.types, value - 1, 1);
type_set_expand(&db->role_val_to_struct[i]->types, &db->role_val_to_struct[i]->cache, db, 0);
}
return set_attr(db, "domain", value);
}
int set_domain_state(policydb_t *db, const char *s, int state) {
type_datum_t *type;
if (s == NULL) {
hashtab_for_each(db->p_types.table, {
type = node->datum;
if (ebitmap_set_bit(&db->permissive_map, type->s.value, state)) {
LOGW("Could not set bit in permissive map\n");
return 1;
}
})
} else {
type = hashtab_search(db->p_types.table, s);
if (type == NULL) {
LOGW("type %s does not exist\n", s);
return 1;
}
if (ebitmap_set_bit(&db->permissive_map, type->s.value, state)) {
LOGW("Could not set bit in permissive map\n");
return 1;
}
}
return 0;
}
int add_filename_trans(policydb_t *db, const char *s, const char *t, const char *c, const char *d,
const char *o) {
type_datum_t *src, *tgt, *def;
class_datum_t *cls;
src = hashtab_search(db->p_types.table, s);
if (src == NULL) {
LOGW("source type %s does not exist\n", s);
return 1;
}
tgt = hashtab_search(db->p_types.table, t);
if (tgt == NULL) {
LOGW("target type %s does not exist\n", t);
return 1;
}
cls = hashtab_search(db->p_classes.table, c);
if (cls == NULL) {
LOGW("class %s does not exist\n", c);
return 1;
}
def = hashtab_search(db->p_types.table, d);
if (def == NULL) {
LOGW("default type %s does not exist\n", d);
return 1;
}
filename_trans_t trans_key;
trans_key.stype = src->s.value;
trans_key.ttype = tgt->s.value;
trans_key.tclass = cls->s.value;
trans_key.name = (char *) o;
filename_trans_datum_t *trans_datum;
trans_datum = hashtab_search(db->filename_trans, (hashtab_key_t) &trans_key);
if (trans_datum == NULL) {
trans_datum = xcalloc(sizeof(*trans_datum), 1);
hashtab_insert(db->filename_trans, (hashtab_key_t) &trans_key, trans_datum);
}
// Overwrite existing
trans_datum->otype = def->s.value;
return 0;
}
int add_typeattribute(policydb_t *db, const char *type, const char *attr) {
type_datum_t *domain = hashtab_search(db->p_types.table, type);
if (domain == NULL) {
LOGW("type %s does not exist\n", type);
return 1;
}
int attr_id = set_attr(db, attr, domain->s.value);
if (attr_id < 0)
return 1;
hashtab_for_each(db->p_classes.table, {
class_datum_t *cls = node->datum;
for (constraint_node_t *n = cls->constraints; n ; n = n->next) {
for (constraint_expr_t *e = n->expr; e; e = e->next) {
if (e->expr_type == CEXPR_NAMES &&
ebitmap_get_bit(&e->type_names->types, attr_id - 1)) {
ebitmap_set_bit(&e->names, domain->s.value - 1, 1);
}
}
}
})
return 0;
}
int add_rule(policydb_t *db,
const char *s, const char *t, const char *c, const char *p, int effect, int n) {
type_datum_t *src = NULL, *tgt = NULL;
class_datum_t *cls = NULL;
perm_datum_t *perm = NULL;
if (s) {
src = hashtab_search(db->p_types.table, s);
if (src == NULL) {
LOGW("source type %s does not exist\n", s);
return 1;
}
}
if (t) {
tgt = hashtab_search(db->p_types.table, t);
if (tgt == NULL) {
LOGW("target type %s does not exist\n", t);
return 1;
}
}
if (c) {
cls = hashtab_search(db->p_classes.table, c);
if (cls == NULL) {
LOGW("class %s does not exist\n", c);
return 1;
}
}
if (p) {
if (c == NULL) {
LOGW("No class is specified, cannot add perm [%s] \n", p);
return 1;
}
perm = hashtab_search(cls->permissions.table, p);
if (perm == NULL && cls->comdatum != NULL) {
perm = hashtab_search(cls->comdatum->permissions.table, p);
}
if (perm == NULL) {
LOGW("perm %s does not exist in class %s\n", p, c);
return 1;
}
}
return add_rule_auto(db, src, tgt, cls, perm, effect, n);
}
int add_xperm_rule(policydb_t *db, const char *s, const char *t, const char *c, const char *range,
int effect, int n) {
type_datum_t *src = NULL, *tgt = NULL;
class_datum_t *cls = NULL;
if (s) {
src = hashtab_search(db->p_types.table, s);
if (src == NULL) {
LOGW("source type %s does not exist\n", s);
return 1;
}
}
if (t) {
tgt = hashtab_search(db->p_types.table, t);
if (tgt == NULL) {
LOGW("target type %s does not exist\n", t);
return 1;
}
}
if (c) {
cls = hashtab_search(db->p_classes.table, c);
if (cls == NULL) {
LOGW("class %s does not exist\n", c);
return 1;
}
}
uint16_t low, high;
if (range) {
if (strchr(range, '-')){
sscanf(range, "%hx-%hx", &low, &high);
} else {
sscanf(range, "%hx", &low);
high = low;
}
} else {
low = 0;
high = 0xFFFF;
}
return add_xperm_rule_auto(db, src, tgt, cls, low, high, effect, n);
}
int add_type_rule(policydb_t *db,
const char *s, const char *t, const char *c, const char *d, int effect) {
type_datum_t *src, *tgt, *def;
class_datum_t *cls;
src = hashtab_search(db->p_types.table, s);
if (src == NULL) {
LOGW("source type %s does not exist\n", s);
return 1;
}
tgt = hashtab_search(db->p_types.table, t);
if (tgt == NULL) {
LOGW("target type %s does not exist\n", t);
return 1;
}
cls = hashtab_search(db->p_classes.table, c);
if (cls == NULL) {
LOGW("class %s does not exist\n", c);
return 1;
}
def = hashtab_search(db->p_types.table, d);
if (def == NULL) {
LOGW("default type %s does not exist\n", d);
return 1;
}
avtab_key_t key;
key.source_type = src->s.value;
key.target_type = tgt->s.value;
key.target_class = cls->s.value;
key.specified = effect;
avtab_ptr_t node = get_avtab_node(db, &key, NULL);
node->datum.data = def->s.value;
return 0;
}
int add_genfscon(policydb_t *db, const char *name, const char *path, const char *context) {
// First try to create context
context_struct_t *ctx;
if (context_from_string(NULL, db, &ctx, context, strlen(context))) {
LOGW("Failed to create context from string [%s]\n", context);
return 1;
}
// Allocate genfs context
ocontext_t *newc = xcalloc(sizeof(*newc), 1);
newc->u.name = strdup(path);
memcpy(&newc->context[0], ctx, sizeof(*ctx));
free(ctx);
// Find or allocate genfs
genfs_t *last_gen = NULL;
genfs_t *newfs = NULL;
for (genfs_t *node = db->genfs; node; node = node->next) {
if (strcmp(node->fstype, name) == 0) {
newfs = node;
break;
}
last_gen = node;
}
if (newfs == NULL) {
newfs = xcalloc(sizeof(*newfs), 1);
newfs->fstype = strdup(name);
// Insert
if (last_gen)
last_gen->next = newfs;
else
db->genfs = newfs;
}
// Insert or replace genfs context
ocontext_t *last_ctx = NULL;
for (ocontext_t *node = newfs->head; node; node = node->next) {
if (strcmp(node->u.name, path) == 0) {
// Unlink
if (last_ctx)
last_ctx->next = node->next;
else
newfs->head = NULL;
// Destroy old node
free(node->u.name);
context_destroy(&node->context[0]);
free(node);
break;
}
last_ctx = node;
}
// Insert
if (last_ctx)
last_ctx->next = newc;
else
newfs->head = newc;
return 0;
}
void strip_dontaudit(policydb_t *db) {
avtab_for_each(&db->te_avtab, {
if (node->key.specified == AVTAB_AUDITDENY || node->key.specified == AVTAB_XPERMS_DONTAUDIT)
avtab_remove_node(&db->te_avtab, node);
})
}

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#include <sepol/policydb/policydb.h>
#include <magiskpolicy.hpp>
#include <logging.hpp>
#include <utils.hpp>
#include "sepolicy.hpp"
#if 0
// Print out all rules going through public API for debugging
template <typename ...Args>
static void dprint(const char *action, Args ...args) {
std::string s(action);
for (int i = 0; i < sizeof...(args); ++i) s += " %s";
s += "\n";
LOGD(s.data(), (args ? args : "*")...);
}
#else
#define dprint(...)
#endif
template <typename T>
struct auto_cast_wrapper
{
auto_cast_wrapper(T *ptr) : ptr(ptr) {}
template <typename U>
operator U*() const { return static_cast<U*>(ptr); }
private:
T *ptr;
};
template <typename T>
static auto_cast_wrapper<T> auto_cast(T *p) {
return auto_cast_wrapper<T>(p);
}
static auto hashtab_find(hashtab_t h, const_hashtab_key_t key) {
return auto_cast(hashtab_search(h, key));
}
template <class Node, class Func>
static void hash_for_each(Node **node_ptr, int n_slot, const Func &fn) {
for (int i = 0; i < n_slot; ++i) {
for (Node *cur = node_ptr[i]; cur; cur = cur->next) {
fn(cur);
}
}
}
#define hashtab_for_each(hashtab, fn) \
hash_for_each((hashtab)->htable, (hashtab)->size, fn)
#define avtab_for_each(avtab, fn) \
hash_for_each((avtab)->htable, (avtab)->nslot, fn)
// libsepol internal APIs
extern "C" int policydb_index_decls(sepol_handle_t * handle, policydb_t * p);
extern "C" int context_from_string(
sepol_handle_t * handle,
const policydb_t * policydb,
context_struct_t ** cptr,
const char *con_str, size_t con_str_len);
extern "C" int type_set_expand(
type_set_t * set, ebitmap_t * t, policydb_t * p,
unsigned char alwaysexpand);
int sepol_impl::set_attr(const char *attr_name, int type_val) {
type_datum_t *attr = hashtab_find(db->p_types.table, attr_name);
if (!attr || attr->flavor != TYPE_ATTRIB)
return -1;
if (ebitmap_set_bit(&db->type_attr_map[type_val - 1], attr->s.value - 1, 1))
return -1;
if (ebitmap_set_bit(&db->attr_type_map[attr->s.value - 1], type_val - 1, 1))
return -1;
return attr->s.value;
}
void sepol_impl::check_avtab_node(avtab_ptr_t node) {
bool redundant;
if (node->key.specified == AVTAB_AUDITDENY)
redundant = node->datum.data == ~0U;
else if (node->key.specified & AVTAB_XPERMS)
redundant = node->datum.xperms == nullptr;
else
redundant = node->datum.data == 0U;
if (redundant)
avtab_remove_node(&db->te_avtab, node);
}
avtab_ptr_t sepol_impl::get_avtab_node(avtab_key_t *key, avtab_extended_perms_t *xperms) {
avtab_ptr_t node;
/* AVTAB_XPERMS entries are not necessarily unique */
if (key->specified & AVTAB_XPERMS) {
bool match = false;
node = avtab_search_node(&db->te_avtab, key);
while (node) {
if ((node->datum.xperms->specified == xperms->specified) &&
(node->datum.xperms->driver == xperms->driver)) {
match = true;
break;
}
node = avtab_search_node_next(node, key->specified);
}
if (!match)
node = nullptr;
} else {
node = avtab_search_node(&db->te_avtab, key);
}
if (!node) {
avtab_datum_t avdatum{};
/*
* AUDITDENY, aka DONTAUDIT, are &= assigned, versus |= for
* others. Initialize the data accordingly.
*/
avdatum.data = key->specified == AVTAB_AUDITDENY ? ~0U : 0U;
/* this is used to get the node - insertion is actually unique */
node = avtab_insert_nonunique(&db->te_avtab, key, &avdatum);
}
return node;
}
int sepol_impl::add_avrule(avtab_key_t *key, int val, bool n) {
avtab_ptr_t node = get_avtab_node(key, nullptr);
if (n) {
if (val < 0)
node->datum.data = 0U;
else
node->datum.data &= ~(1U << (val - 1));
} else {
if (val < 0)
node->datum.data = ~0U;
else
node->datum.data |= 1U << (val - 1);
}
check_avtab_node(node);
return 0;
}
int sepol_impl::add_rule(type_datum_t *src, type_datum_t *tgt, class_datum_t *cls, perm_datum_t *perm, int effect, bool n) {
int ret = 0;
if (src == nullptr) {
hashtab_for_each(db->p_types.table, [&](hashtab_ptr_t node) {
src = auto_cast(node->datum);
ret |= add_rule(src, tgt, cls, perm, effect, n);
});
} else if (tgt == nullptr) {
hashtab_for_each(db->p_types.table, [&](hashtab_ptr_t node) {
tgt = auto_cast(node->datum);
ret |= add_rule(src, tgt, cls, perm, effect, n);
});
} else if (cls == nullptr) {
hashtab_for_each(db->p_classes.table, [&](hashtab_ptr_t node) {
cls = auto_cast(node->datum);
ret |= add_rule(src, tgt, cls, perm, effect, n);
});
} else {
avtab_key_t key;
key.source_type = src->s.value;
key.target_type = tgt->s.value;
key.target_class = cls->s.value;
key.specified = effect;
return add_avrule(&key, perm ? perm->s.value : -1, n);
}
return ret;
}
int sepol_impl::add_rule(const char *s, const char *t, const char *c, const char *p, int effect, bool n) {
type_datum_t *src = nullptr, *tgt = nullptr;
class_datum_t *cls = nullptr;
perm_datum_t *perm = nullptr;
if (s) {
src = hashtab_find(db->p_types.table, s);
if (src == nullptr) {
LOGW("source type %s does not exist\n", s);
return 1;
}
}
if (t) {
tgt = hashtab_find(db->p_types.table, t);
if (tgt == nullptr) {
LOGW("target type %s does not exist\n", t);
return 1;
}
}
if (c) {
cls = hashtab_find(db->p_classes.table, c);
if (cls == nullptr) {
LOGW("class %s does not exist\n", c);
return 1;
}
}
if (p) {
if (c == nullptr) {
LOGW("No class is specified, cannot add perm [%s] \n", p);
return 1;
}
perm = hashtab_find(cls->permissions.table, p);
if (perm == nullptr && cls->comdatum != nullptr) {
perm = hashtab_find(cls->comdatum->permissions.table, p);
}
if (perm == nullptr) {
LOGW("perm %s does not exist in class %s\n", p, c);
return 1;
}
}
return add_rule(src, tgt, cls, perm, effect, n);
}
#define ioctl_driver(x) (x>>8 & 0xFF)
#define ioctl_func(x) (x & 0xFF)
int sepol_impl::add_avxrule(avtab_key_t *key, uint16_t low, uint16_t high, bool n) {
avtab_datum_t *datum;
avtab_extended_perms_t xperms;
memset(&xperms, 0, sizeof(xperms));
if (ioctl_driver(low) != ioctl_driver(high)) {
xperms.specified = AVTAB_XPERMS_IOCTLDRIVER;
xperms.driver = 0;
} else {
xperms.specified = AVTAB_XPERMS_IOCTLFUNCTION;
xperms.driver = ioctl_driver(low);
}
if (xperms.specified == AVTAB_XPERMS_IOCTLDRIVER) {
for (int i = ioctl_driver(low); i <= ioctl_driver(high); ++i) {
if (n)
xperm_clear(i, xperms.perms);
else
xperm_set(i, xperms.perms);
}
} else {
for (int i = ioctl_func(low); i <= ioctl_func(high); ++i) {
if (n)
xperm_clear(i, xperms.perms);
else
xperm_set(i, xperms.perms);
}
}
datum = &get_avtab_node(key, &xperms)->datum;
if (datum->xperms == nullptr)
datum->xperms = auto_cast(xmalloc(sizeof(xperms)));
memcpy(datum->xperms, &xperms, sizeof(xperms));
return 0;
}
int sepol_impl::add_xperm_rule(type_datum_t *src, type_datum_t *tgt,
class_datum_t *cls, uint16_t low, uint16_t high, int effect, bool n) {
int ret = 0;
if (src == nullptr) {
hashtab_for_each(db->p_types.table, [&](hashtab_ptr_t node) {
src = auto_cast(node->datum);
ret |= add_xperm_rule(src, tgt, cls, low, high, effect, n);
});
} else if (tgt == nullptr) {
hashtab_for_each(db->p_types.table, [&](hashtab_ptr_t node) {
tgt = auto_cast(node->datum);
ret |= add_xperm_rule(src, tgt, cls, low, high, effect, n);
});
} else if (cls == nullptr) {
hashtab_for_each(db->p_classes.table, [&](hashtab_ptr_t node) {
tgt = auto_cast(node->datum);
ret |= add_xperm_rule(src, tgt, cls, low, high, effect, n);
});
} else {
avtab_key_t key;
key.source_type = src->s.value;
key.target_type = tgt->s.value;
key.target_class = cls->s.value;
key.specified = effect;
return add_avxrule(&key, low, high, n);
}
return ret;
}
int sepol_impl::add_xperm_rule(const char *s, const char *t, const char *c, const char *range, int effect, bool n) {
type_datum_t *src = nullptr, *tgt = nullptr;
class_datum_t *cls = nullptr;
if (s) {
src = hashtab_find(db->p_types.table, s);
if (src == nullptr) {
LOGW("source type %s does not exist\n", s);
return 1;
}
}
if (t) {
tgt = hashtab_find(db->p_types.table, t);
if (tgt == nullptr) {
LOGW("target type %s does not exist\n", t);
return 1;
}
}
if (c) {
cls = hashtab_find(db->p_classes.table, c);
if (cls == nullptr) {
LOGW("class %s does not exist\n", c);
return 1;
}
}
uint16_t low, high;
if (range) {
if (strchr(range, '-')){
sscanf(range, "%hx-%hx", &low, &high);
} else {
sscanf(range, "%hx", &low);
high = low;
}
} else {
low = 0;
high = 0xFFFF;
}
return add_xperm_rule(src, tgt, cls, low, high, effect, n);
}
int sepol_impl::create_domain(const char *type_name) {
symtab_datum_t *src = hashtab_find(db->p_types.table, type_name);
if (src) {
LOGW("Type %s already exists\n", type_name);
return 0;
}
type_datum_t *type = auto_cast(xmalloc(sizeof(type_datum_t)));
type_datum_init(type);
type->primary = 1;
type->flavor = TYPE_TYPE;
uint32_t value = 0;
symtab_insert(db, SYM_TYPES, strdup(type_name), type, SCOPE_DECL, 1, &value);
type->s.value = value;
if (ebitmap_set_bit(&db->global->branch_list->declared.scope[SYM_TYPES], value - 1, 1)) {
return 1;
}
db->type_attr_map = auto_cast(xrealloc(db->type_attr_map, sizeof(ebitmap_t) * db->p_types.nprim));
db->attr_type_map = auto_cast(xrealloc(db->attr_type_map, sizeof(ebitmap_t) * db->p_types.nprim));
ebitmap_init(&db->type_attr_map[value - 1]);
ebitmap_init(&db->attr_type_map[value - 1]);
ebitmap_set_bit(&db->type_attr_map[value - 1], value - 1, 1);
src = hashtab_find(db->p_types.table, type_name);
if (!src)
return 1;
if (policydb_index_decls(nullptr, db))
return 1;
if (policydb_index_classes(db))
return 1;
if (policydb_index_others(nullptr, db, 0))
return 1;
// Add the domain to all roles
for (unsigned i = 0; i < db->p_roles.nprim; ++i) {
// Not sure all those three calls are needed
ebitmap_set_bit(&db->role_val_to_struct[i]->types.negset, value - 1, 0);
ebitmap_set_bit(&db->role_val_to_struct[i]->types.types, value - 1, 1);
type_set_expand(&db->role_val_to_struct[i]->types, &db->role_val_to_struct[i]->cache, db, 0);
}
return set_attr("domain", value);
}
int sepol_impl::set_domain_state(const char *s, bool permissive) {
type_datum_t *type;
if (s == nullptr) {
hashtab_for_each(db->p_types.table, [&](hashtab_ptr_t node) {
type = auto_cast(node->datum);
if (ebitmap_set_bit(&db->permissive_map, type->s.value, permissive))
LOGW("Could not set bit in permissive map\n");
});
} else {
type = hashtab_find(db->p_types.table, s);
if (type == nullptr) {
LOGW("type %s does not exist\n", s);
return 1;
}
if (ebitmap_set_bit(&db->permissive_map, type->s.value, permissive)) {
LOGW("Could not set bit in permissive map\n");
return 1;
}
}
return 0;
}
int sepol_impl::add_filename_trans(const char *s, const char *t, const char *c, const char *d, const char *o) {
type_datum_t *src, *tgt, *def;
class_datum_t *cls;
filename_trans_datum_t *trans;
src = hashtab_find(db->p_types.table, s);
if (src == nullptr) {
LOGW("source type %s does not exist\n", s);
return 1;
}
tgt = hashtab_find(db->p_types.table, t);
if (tgt == nullptr) {
LOGW("target type %s does not exist\n", t);
return 1;
}
cls = hashtab_find(db->p_classes.table, c);
if (cls == nullptr) {
LOGW("class %s does not exist\n", c);
return 1;
}
def = hashtab_find(db->p_types.table, d);
if (def == nullptr) {
LOGW("default type %s does not exist\n", d);
return 1;
}
filename_trans_t trans_key;
trans_key.stype = src->s.value;
trans_key.ttype = tgt->s.value;
trans_key.tclass = cls->s.value;
trans_key.name = (char *) o;
trans = hashtab_find(db->filename_trans, (hashtab_key_t) &trans_key);
if (trans == nullptr) {
trans = auto_cast(xcalloc(sizeof(*trans), 1));
hashtab_insert(db->filename_trans, (hashtab_key_t) &trans_key, trans);
}
// Overwrite existing
trans->otype = def->s.value;
return 0;
}
int sepol_impl::add_typeattribute(const char *type, const char *attr) {
type_datum_t *domain = hashtab_find(db->p_types.table, type);
if (domain == nullptr) {
LOGW("type %s does not exist\n", type);
return 1;
}
int attr_val = set_attr(attr, domain->s.value);
if (attr_val < 0)
return 1;
hashtab_for_each(db->p_classes.table, [&](hashtab_ptr_t node){
auto cls = static_cast<class_datum_t *>(node->datum);
for (constraint_node_t *n = cls->constraints; n ; n = n->next) {
for (constraint_expr_t *e = n->expr; e; e = e->next) {
if (e->expr_type == CEXPR_NAMES &&
ebitmap_get_bit(&e->type_names->types, attr_val - 1)) {
ebitmap_set_bit(&e->names, domain->s.value - 1, 1);
}
}
}
});
return 0;
}
int sepol_impl::add_type_rule(const char *s, const char *t, const char *c, const char *d, int effect) {
type_datum_t *src, *tgt, *def;
class_datum_t *cls;
src = hashtab_find(db->p_types.table, s);
if (src == nullptr) {
LOGW("source type %s does not exist\n", s);
return 1;
}
tgt = hashtab_find(db->p_types.table, t);
if (tgt == nullptr) {
LOGW("target type %s does not exist\n", t);
return 1;
}
cls = hashtab_find(db->p_classes.table, c);
if (cls == nullptr) {
LOGW("class %s does not exist\n", c);
return 1;
}
def = hashtab_find(db->p_types.table, d);
if (def == nullptr) {
LOGW("default type %s does not exist\n", d);
return 1;
}
avtab_key_t key;
key.source_type = src->s.value;
key.target_type = tgt->s.value;
key.target_class = cls->s.value;
key.specified = effect;
avtab_ptr_t node = get_avtab_node(&key, nullptr);
node->datum.data = def->s.value;
return 0;
}
int sepol_impl::add_genfscon(const char *fs_name, const char *path, const char *context) {
// First try to create context
context_struct_t *ctx;
if (context_from_string(nullptr, db, &ctx, context, strlen(context))) {
LOGW("Failed to create context from string [%s]\n", context);
return 1;
}
// Allocate genfs context
ocontext_t *newc = auto_cast(xcalloc(sizeof(*newc), 1));
newc->u.name = strdup(path);
memcpy(&newc->context[0], ctx, sizeof(*ctx));
free(ctx);
// Find or allocate genfs
genfs_t *last_gen = nullptr;
genfs_t *newfs = nullptr;
for (genfs_t *node = db->genfs; node; node = node->next) {
if (strcmp(node->fstype, fs_name) == 0) {
newfs = node;
break;
}
last_gen = node;
}
if (newfs == nullptr) {
newfs = auto_cast(xcalloc(sizeof(*newfs), 1));
newfs->fstype = strdup(fs_name);
// Insert
if (last_gen)
last_gen->next = newfs;
else
db->genfs = newfs;
}
// Insert or replace genfs context
ocontext_t *last_ctx = nullptr;
for (ocontext_t *node = newfs->head; node; node = node->next) {
if (strcmp(node->u.name, path) == 0) {
// Unlink
if (last_ctx)
last_ctx->next = node->next;
else
newfs->head = nullptr;
// Destroy old node
free(node->u.name);
context_destroy(&node->context[0]);
free(node);
break;
}
last_ctx = node;
}
// Insert
if (last_ctx)
last_ctx->next = newc;
else
newfs->head = newc;
return 0;
}
void sepol_impl::strip_dontaudit() {
avtab_for_each(&db->te_avtab, [=](avtab_ptr_t node) {
if (node->key.specified == AVTAB_AUDITDENY || node->key.specified == AVTAB_XPERMS_DONTAUDIT)
avtab_remove_node(&db->te_avtab, node);
});
}
int sepolicy::allow(const char *s, const char *t, const char *c, const char *p) {
dprint(__FUNCTION__, s, t, c, p);
return impl->add_rule(s, t, c, p, AVTAB_ALLOWED, false);
}
int sepolicy::deny(const char *s, const char *t, const char *c, const char *p) {
dprint(__FUNCTION__, s, t, c, p);
return impl->add_rule(s, t, c, p, AVTAB_ALLOWED, true);
}
int sepolicy::auditallow(const char *s, const char *t, const char *c, const char *p) {
dprint(__FUNCTION__, s, t, c, p);
return impl->add_rule(s, t, c, p, AVTAB_AUDITALLOW, false);
}
int sepolicy::dontaudit(const char *s, const char *t, const char *c, const char *p) {
dprint(__FUNCTION__, s, t, c, p);
return impl->add_rule(s, t, c, p, AVTAB_AUDITDENY, true);
}
int sepolicy::allowxperm(const char *s, const char *t, const char *c, const char *range) {
dprint(__FUNCTION__, s, t, c, "ioctl", range);
return impl->add_xperm_rule(s, t, c, range, AVTAB_XPERMS_ALLOWED, false);
}
int sepolicy::auditallowxperm(const char *s, const char *t, const char *c, const char *range) {
dprint(__FUNCTION__, s, t, c, "ioctl", range);
return impl->add_xperm_rule(s, t, c, range, AVTAB_XPERMS_AUDITALLOW, false);
}
int sepolicy::dontauditxperm(const char *s, const char *t, const char *c, const char *range) {
dprint(__FUNCTION__, s, t, c, "ioctl", range);
return impl->add_xperm_rule(s, t, c, range, AVTAB_XPERMS_DONTAUDIT, false);
}
int sepolicy::type_change(const char *s, const char *t, const char *c, const char *d) {
dprint(__FUNCTION__, s, t, c, d);
return impl->add_type_rule(s, t, c, d, AVTAB_CHANGE);
}
int sepolicy::type_member(const char *s, const char *t, const char *c, const char *d) {
dprint(__FUNCTION__, s, t, c, d);
return impl->add_type_rule(s, t, c, d, AVTAB_MEMBER);
}
int sepolicy::type_transition(const char *s, const char *t, const char *c, const char *d, const char *o) {
if (o) {
dprint(__FUNCTION__, s, t, c, d);
return impl->add_type_rule(s, t, c, d, AVTAB_TRANSITION);
} else {
dprint(__FUNCTION__, s, t, c, d, o);
return impl->add_filename_trans(s, t, c, d, o);
}
}
int sepolicy::permissive(const char *s) {
dprint(__FUNCTION__, s);
return impl->set_domain_state(s, true);
}
int sepolicy::enforce(const char *s) {
dprint(__FUNCTION__, s);
return impl->set_domain_state(s, false);
}
int sepolicy::create(const char *s) {
dprint(__FUNCTION__, s);
return impl->create_domain(s);
}
int sepolicy::typeattribute(const char *type, const char *attr) {
dprint(__FUNCTION__, type, attr);
return impl->add_typeattribute(type, attr);
}
int sepolicy::genfscon(const char *fs_name, const char *path, const char *ctx) {
dprint(__FUNCTION__, fs_name, path, ctx);
return impl->add_genfscon(fs_name, path, ctx);
}
int sepolicy::exists(const char *source) {
return hashtab_search(db->p_types.table, source) != nullptr;
}

24
native/jni/magiskpolicy/sepolicy.h
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@ -1,24 +0,0 @@
#pragma once
#include <sepol/policydb/policydb.h>
__BEGIN_DECLS
// Internal C APIs, do not use directly
int create_domain(policydb_t *db, const char *d);
int set_domain_state(policydb_t *db, const char *s, int state);
int add_typeattribute(policydb_t *db, const char *type, const char *attr);
int add_rule(policydb_t *db, const char *s, const char *t, const char *c, const char *p, int effect,
int n);
int add_xperm_rule(policydb_t *db, const char *s, const char *t, const char *c, const char *range,
int effect, int n);
int add_type_rule(policydb_t *db, const char *s, const char *t, const char *c, const char *d,
int effect);
int add_filename_trans(policydb_t *db, const char *s, const char *t, const char *c, const char *d,
const char *o);
int add_genfscon(policydb_t *db, const char *name, const char *path, const char *context);
void strip_dontaudit(policydb_t *db);
void statement_help();
__END_DECLS

30
native/jni/magiskpolicy/sepolicy.hpp Normal file
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@ -0,0 +1,30 @@
#pragma once
#include <sepol/policydb/policydb.h>
#include <magiskpolicy.hpp>
// Internal APIs, do not use directly
struct sepol_impl : public sepolicy {
int set_attr(const char *attr_name, int type_val);
void check_avtab_node(avtab_ptr_t node);
avtab_ptr_t get_avtab_node(avtab_key_t *key, avtab_extended_perms_t *xperms);
int add_avrule(avtab_key_t *key, int val, bool n);
int add_rule(const char *s, const char *t, const char *c, const char *p, int effect, bool n);
int add_rule(type_datum_t *src, type_datum_t *tgt, class_datum_t *cls, perm_datum_t *perm, int effect, bool n);
int add_avxrule(avtab_key_t *key, uint16_t low, uint16_t high, bool n);
int add_xperm_rule(type_datum_t *src, type_datum_t *tgt,
class_datum_t *cls, uint16_t low, uint16_t high, int effect, bool n);
int add_xperm_rule(const char *s, const char *t, const char *c, const char *range, int effect, bool n);
int create_domain(const char *type_name);
int set_domain_state(const char *s, bool permissive);
int add_filename_trans(const char *s, const char *t, const char *c, const char *d, const char *o);
int add_typeattribute(const char *type, const char *attr);
int add_type_rule(const char *s, const char *t, const char *c, const char *d, int effect);
int add_genfscon(const char *fs_name, const char *path, const char *context);
void strip_dontaudit();
void allow_su_client(const char *type);
};
#define impl static_cast<sepol_impl *>(this)
void statement_help();

2
native/jni/magiskpolicy/statement.cpp
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@ -6,7 +6,7 @@
#include <logging.hpp>
#include <utils.hpp>
#include "sepolicy.h"
#include "sepolicy.hpp"
using namespace std;