Magisk/native/jni/magiskpolicy/statement.cpp
2020-03-09 01:50:30 -07:00

460 lines
10 KiB
C++

#include <cstring>
#include <vector>
#include <string>
#include <magiskpolicy.hpp>
#include <logging.hpp>
#include <utils.hpp>
using namespace std;
static const char *type_msg_1 =
R"EOF(Type 1:
"<rule_name> source_type target_type class perm_set"
Rules: allow, deny, auditallow, dontaudit
)EOF";
static const char *type_msg_2 =
R"EOF(Type 2:
"<rule_name> source_type target_type class operation xperm_set"
Rules: allowxperm, auditallowxperm, dontauditxperm
* The only supported operation is ioctl
* The only supported xperm_set format is range ([low-high])
)EOF";
static const char *type_msg_3 =
R"EOF(Type 3:
"<rule_name> class"
Rules: create, permissive, enforcing
)EOF";
static const char *type_msg_4 =
R"EOF(Type 4:
"attradd class attribute"
)EOF";
static const char *type_msg_5 =
R"EOF(Type 5:
"<rule_name> source_type target_type class default_type"
Rules: type_transition, type_change, type_member
)EOF";
static const char *type_msg_6 =
R"EOF(Type 6:
"name_transition source_type target_type class default_type object_name"
)EOF";
static const char *type_msg_7 =
R"EOF(Type 7:
"genfscon fs_name partial_path fs_context"
)EOF";
void statement_help() {
fprintf(stderr,
R"EOF(One policy statement should be treated as one parameter;
this means a full policy statement should be enclosed in quotes.
Multiple policy statements can be provided in a single command.
The statements has a format of "<rule_name> [args...]"
Multiple types and permissions can be grouped into collections
wrapped in curly brackets.
'*' represents a collection containing all valid matches.
Supported policy statements:
%s
%s
%s
%s
%s
%s
%s
Notes:
* Type 4 - 7 does not support collections
* Object classes cannot be collections
* source_type and target_type can also be attributes
Example: allow { s1 s2 } { t1 t2 } class *
Will be expanded to:
allow s1 t1 class { all-permissions }
allow s1 t2 class { all-permissions }
allow s2 t1 class { all-permissions }
allow s2 t2 class { all-permissions }
)EOF", type_msg_1, type_msg_2, type_msg_3, type_msg_4, type_msg_5, type_msg_6, type_msg_7);
exit(0);
}
static int parse_bracket(char *tok, char *&stmt, vector<const char *> &vec) {
if (tok == nullptr || tok[0] != '{') {
// Not in a bracket
vec.push_back(tok);
} else {
if (stmt)
stmt[-1] = ' ';
tok = strchr(tok, '{') + 1;
char *end = strchr(tok, '}');
if (end == nullptr) // Bracket not closed
return 1;
*end = '\0';
char *cur;
while ((cur = strtok_r(nullptr, " ", &tok)) != nullptr)
vec.push_back(cur);
stmt = end + 1;
}
return 0;
}
// Pattern 1: action { source } { target } class { permission }
static int parse_pattern_1(int action, const char *action_str, char *stmt) {
int (*action_func)(const char*, const char*, const char*, const char*);
switch (action) {
case 0:
action_func = sepol_allow;
break;
case 1:
action_func = sepol_deny;
break;
case 2:
action_func = sepol_auditallow;
break;
case 3:
action_func = sepol_dontaudit;
break;
default:
return 1;
}
int state = 0;
char *cur, *cls;
vector<const char*> source, target, permission;
while ((cur = strtok_r(nullptr, " ", &stmt)) != nullptr) {
if (cur[0] == '*') cur = ALL;
vector<const char *> *vec;
switch (state) {
case 0:
vec = &source;
break;
case 1:
vec = &target;
break;
case 2:
vec = nullptr;
cls = cur;
break;
case 3:
vec = &permission;
break;
default:
return 1;
}
if (vec && parse_bracket(cur, stmt, *vec))
return 1;
++state;
}
if (state != 4 || source.empty() || target.empty() || permission.empty())
return 1;
for (auto src : source)
for (auto tgt : target)
for (auto perm : permission)
if (action_func(src, tgt, cls, perm))
LOGW("Error in: %s %s %s %s %s\n", action_str, src, tgt, cls, perm);
return 0;
}
// Pattern 2: action { source } { target } { class } ioctl range
static int parse_pattern_2(int action, const char *action_str, char *stmt) {
int (*action_func)(const char*, const char*, const char*, const char*);
switch (action) {
case 0:
action_func = sepol_allowxperm;
break;
case 1:
action_func = sepol_auditallowxperm;
break;
case 2:
action_func = sepol_dontauditxperm;
break;
default:
return 1;
}
int state = 0;
char *cur, *range;
vector<const char *> source, target, classes;
while ((cur = strtok_r(nullptr, " ", &stmt)) != nullptr) {
if (cur[0] == '*') cur = ALL;
vector<const char *> *vec;
switch (state) {
case 0:
vec = &source;
break;
case 1:
vec = &target;
break;
case 2:
vec = &classes;
break;
case 3:
// Currently only support ioctl
if (strcmp(cur, "ioctl") != 0)
return 1;
vec = nullptr;
break;
case 4:
vec = nullptr;
range = cur;
break;
default:
return 1;
}
if (vec && parse_bracket(cur, stmt, *vec))
return 1;
++state;
}
if (state != 5 || source.empty() || target.empty() || classes.empty())
return 1;
for (auto src : source)
for (auto tgt : target)
for (auto cls : classes)
if (action_func(src, tgt, cls, range))
LOGW("Error in: %s %s %s %s %s\n", action_str, src, tgt, cls, range);
return 0;
}
// Pattern 3: action { type }
static int parse_pattern_3(int action, const char *action_str, char* stmt) {
int (*action_func)(const char*);
switch (action) {
case 0:
action_func = sepol_create;
break;
case 1:
action_func = sepol_permissive;
break;
case 2:
action_func = sepol_enforce;
break;
default:
return 1;
}
char *cur;
vector<const char *> domains;
while ((cur = strtok_r(nullptr, " {}", &stmt)) != nullptr) {
if (cur[0] == '*') cur = ALL;
domains.push_back(cur);
}
if (domains.empty())
return 1;
for (auto dom : domains)
if (action_func(dom))
LOGW("Error in: %s %s\n", action_str, dom);
return 0;
}
// Pattern 4: action { class } { attribute }
static int parse_pattern_4(int action, const char *action_str, char *stmt) {
int (*action_func)(const char*, const char*);
switch (action) {
case 0:
action_func = sepol_attradd;
break;
default:
return 1;
}
int state = 0;
char *cur;
vector<const char *> classes, attribute;
while ((cur = strtok_r(nullptr, " ", &stmt)) != nullptr) {
if (cur[0] == '*') cur = ALL;
vector<const char *> *vec;
switch (state) {
case 0:
vec = &classes;
break;
case 1:
vec = &attribute;
break;
default:
return 1;
}
if (parse_bracket(cur, stmt, *vec))
return 1;
++state;
}
if (state != 2 || classes.empty() || attribute.empty())
return 1;
for (auto cls : classes)
for (auto attr : attribute)
if (action_func(cls, attr))
LOGW("Error in: %s %s %s\n", action_str, cls, attr);
return 0;
}
// Pattern 5: action source target class default
static int parse_pattern_5(int action, const char *action_str, char *stmt) {
int (*action_func)(const char*, const char*, const char*, const char*);
switch (action) {
case 0:
action_func = sepol_typetrans;
break;
case 1:
action_func = sepol_typechange;
break;
case 2:
action_func = sepol_typemember;
break;
default:
return 1;
}
int state = 0;
char *cur;
char *source, *target, *cls, *def;
while ((cur = strtok_r(nullptr, " ", &stmt)) != nullptr) {
switch(state) {
case 0:
source = cur;
break;
case 1:
target = cur;
break;
case 2:
cls = cur;
break;
case 3:
def = cur;
break;
default:
return 1;
}
++state;
}
if (state < 4) return 1;
if (action_func(source, target, cls, def))
LOGW("Error in: %s %s %s %s %s\n", action_str, source, target, cls, def);
return 0;
}
// Pattern 6: action source target class default filename
static int parse_pattern_6(int action, const char *action_str, char *stmt) {
int state = 0;
char *cur;
char *source, *target, *cls, *def, *filename;
while ((cur = strtok_r(nullptr, " ", &stmt)) != nullptr) {
switch(state) {
case 0:
source = cur;
break;
case 1:
target = cur;
break;
case 2:
cls = cur;
break;
case 3:
def = cur;
break;
case 4:
filename = cur;
break;
default:
return 1;
}
++state;
}
if (state < 5) return 1;
if (sepol_nametrans(source, target, cls, def, filename))
LOGW("Error in: %s %s %s %s %s %s\n", action_str, source, target, cls, def, filename);
return 0;
}
// Pattern 7: action name path context
static int parse_pattern_7(int action, const char *action_str, char *stmt) {
int state = 0;
char *cur;
char *name, *path, *context;
while ((cur = strtok_r(nullptr, " ", &stmt)) != nullptr) {
switch(state) {
case 0:
name = cur;
break;
case 1:
path = cur;
break;
case 2:
context = cur;
break;
default:
return 1;
}
++state;
}
if (state < 3) return 1;
if (sepol_genfscon(name, path, context))
LOGW("Error in: %s %s %s %s\n", action_str, name, path, context);
return 0;
}
#define add_action(name, type, num) \
else if (strcmp(name, action) == 0) { \
if (parse_pattern_##type(num, name, remain)) \
LOGW("Syntax error in '%s'\n\n%s\n", statement, type_msg_##type); \
}
void parse_statement(const char *statement) {
char *action, *remain;
// strtok will modify strings, duplicate the statement
string stmt(statement);
action = strtok_r(stmt.data(), " ", &remain);
if (remain == nullptr) {
LOGE("Syntax error in '%s'\n\n", statement);
return;
}
if (0) {}
add_action("allow", 1, 0)
add_action("deny", 1, 1)
add_action("auditallow", 1, 2)
add_action("dontaudit", 1, 3)
add_action("allowxperm", 2, 0)
add_action("auditallowxperm", 2, 1)
add_action("dontauditxperm", 2, 2)
add_action("create", 3, 0)
add_action("permissive", 3, 1)
add_action("enforce", 3, 2)
add_action("attradd", 4, 0)
add_action("type_transition", 5, 0)
add_action("type_change", 5, 1)
add_action("type_member", 5, 2)
add_action("name_transition", 6, 0)
add_action("genfscon", 7, 0)
else { LOGW("Unknown statement: '%s'\n\n", statement); }
}
void load_rule_file(const char *file) {
file_readline(true, file, [](string_view line) -> bool {
if (line.empty() || line[0] == '#')
return true;
parse_statement(line.data());
return true;
});
}