Magisk/sepolicy.c
2017-02-01 00:51:45 +08:00

501 lines
12 KiB
C

#include "sepolicy-inject.h"
static void *cmalloc(size_t s) {
void *t = malloc(s);
if (t == NULL) {
fprintf(stderr, "Out of memory\n");
exit(1);
}
return t;
}
static int get_attr(char *type, int value) {
type_datum_t *attr = hashtab_search(policy->p_types.table, type);
if (!attr)
exit(1);
if (attr->flavor != TYPE_ATTRIB)
exit(1);
return !! ebitmap_get_bit(&policy->attr_type_map[attr->s.value-1], value-1);
//return !! ebitmap_get_bit(&policy->type_attr_map[value-1], attr->s.value-1);
}
static int get_attr_id(char *type) {
type_datum_t *attr = hashtab_search(policy->p_types.table, type);
if (!attr)
exit(1);
if (attr->flavor != TYPE_ATTRIB)
exit(1);
return attr->s.value;
}
static int set_attr(char *type, int value) {
type_datum_t *attr = hashtab_search(policy->p_types.table, type);
if (!attr)
exit(1);
if (attr->flavor != TYPE_ATTRIB)
exit(1);
if(ebitmap_set_bit(&policy->type_attr_map[value-1], attr->s.value-1, 1))
exit(1);
if(ebitmap_set_bit(&policy->attr_type_map[attr->s.value-1], value-1, 1))
exit(1);
return 0;
}
static int add_irule(int s, int t, int c, int p, int effect, int not) {
avtab_datum_t *av;
avtab_key_t key;
key.source_type = s;
key.target_type = t;
key.target_class = c;
key.specified = effect;
av = avtab_search(&policy->te_avtab, &key);
if (av == NULL) {
av = cmalloc(sizeof(*av));
av->data |= 1U << (p - 1);
int ret = avtab_insert(&policy->te_avtab, &key, av);
if (ret) {
fprintf(stderr, "Error inserting into avtab\n");
return 1;
}
}
if(not)
av->data &= ~(1U << (p - 1));
else
av->data |= 1U << (p - 1);
return 0;
}
static int add_rule_auto(type_datum_t *src, type_datum_t *tgt, class_datum_t *cls, perm_datum_t *perm, int effect, int not) {
hashtab_t type_table, class_table, perm_table;
hashtab_ptr_t cur;
type_table = policy->p_types.table;
class_table = policy->p_classes.table;
if (src == NULL) {
for (int i = 0; i < type_table->size; ++i) {
cur = type_table->htable[i];
while (cur != NULL) {
src = cur->datum;
if(add_rule_auto(src, tgt, cls, perm, effect, not))
return 1;
cur = cur->next;
}
}
} else if (tgt == NULL) {
for (int i = 0; i < type_table->size; ++i) {
cur = type_table->htable[i];
while (cur != NULL) {
tgt = cur->datum;
if(add_rule_auto(src, tgt, cls, perm, effect, not))
return 1;
cur = cur->next;
}
}
} else if (cls == NULL) {
for (int i = 0; i < class_table->size; ++i) {
cur = class_table->htable[i];
while (cur != NULL) {
cls = cur->datum;
if(add_rule_auto(src, tgt, cls, perm, effect, not))
return 1;
cur = cur->next;
}
}
} else if (perm == NULL) {
perm_table = cls->permissions.table;
for (int i = 0; i < perm_table->size; ++i) {
cur = perm_table->htable[i];
while (cur != NULL) {
perm = cur->datum;
if(add_irule(src->s.value, tgt->s.value, cls->s.value, perm->s.value, effect, not))
return 1;
cur = cur->next;
}
}
if (cls->comdatum != NULL) {
perm_table = cls->comdatum->permissions.table;
for (int i = 0; i < perm_table->size; ++i) {
cur = perm_table->htable[i];
while (cur != NULL) {
perm = cur->datum;
if(add_irule(src->s.value, tgt->s.value, cls->s.value, perm->s.value, effect, not))
return 1;
cur = cur->next;
}
}
}
} else {
return add_irule(src->s.value, tgt->s.value, cls->s.value, perm->s.value, effect, not);
}
return 0;
}
int load_policy(char *filename, policydb_t *policydb, struct policy_file *pf) {
int fd;
struct stat sb;
void *map;
int ret;
fd = open(filename, O_RDONLY);
if (fd < 0) {
fprintf(stderr, "Can't open '%s': %s\n",
filename, strerror(errno));
return 1;
}
if (fstat(fd, &sb) < 0) {
fprintf(stderr, "Can't stat '%s': %s\n",
filename, strerror(errno));
return 1;
}
map = mmap(NULL, sb.st_size, PROT_READ | PROT_WRITE, MAP_PRIVATE,
fd, 0);
if (map == MAP_FAILED) {
fprintf(stderr, "Can't mmap '%s': %s\n",
filename, strerror(errno));
return 1;
}
policy_file_init(pf);
pf->type = PF_USE_MEMORY;
pf->data = map;
pf->len = sb.st_size;
if (policydb_init(policydb)) {
fprintf(stderr, "policydb_init: Out of memory!\n");
return 1;
}
ret = policydb_read(policydb, pf, 1);
if (ret) {
fprintf(stderr, "error(s) encountered while parsing configuration\n");
return 1;
}
return 0;
}
void create_domain(char *d) {
symtab_datum_t *src = hashtab_search(policy->p_types.table, d);
if(src)
return;
type_datum_t *typdatum = (type_datum_t *) malloc(sizeof(type_datum_t));
type_datum_init(typdatum);
typdatum->primary = 1;
typdatum->flavor = TYPE_TYPE;
uint32_t value = 0;
int r = symtab_insert(policy, SYM_TYPES, strdup(d), typdatum, SCOPE_DECL, 1, &value);
typdatum->s.value = value;
fprintf(stderr, "source type %s does not exist: %d,%d\n", d, r, value);
if (ebitmap_set_bit(&policy->global->branch_list->declared.scope[SYM_TYPES], value - 1, 1)) {
exit(1);
}
policy->type_attr_map = realloc(policy->type_attr_map, sizeof(ebitmap_t)*policy->p_types.nprim);
policy->attr_type_map = realloc(policy->attr_type_map, sizeof(ebitmap_t)*policy->p_types.nprim);
ebitmap_init(&policy->type_attr_map[value-1]);
ebitmap_init(&policy->attr_type_map[value-1]);
ebitmap_set_bit(&policy->type_attr_map[value-1], value-1, 1);
//Add the domain to all roles
for(unsigned i=0; i<policy->p_roles.nprim; ++i) {
//Not sure all those three calls are needed
ebitmap_set_bit(&policy->role_val_to_struct[i]->types.negset, value-1, 0);
ebitmap_set_bit(&policy->role_val_to_struct[i]->types.types, value-1, 1);
type_set_expand(&policy->role_val_to_struct[i]->types, &policy->role_val_to_struct[i]->cache, policy, 0);
}
src = hashtab_search(policy->p_types.table, d);
if(!src)
exit(1);
extern int policydb_index_decls(policydb_t * p);
if(policydb_index_decls(policy))
exit(1);
if(policydb_index_classes(policy))
exit(1);
if(policydb_index_others(NULL, policy, 1))
exit(1);
set_attr("domain", value);
}
int add_typerule(char *s, char *targetAttribute, char **minusses, char *c, char *p, int effect, int not) {
type_datum_t *src, *tgt;
class_datum_t *cls;
perm_datum_t *perm;
//64(0kB) should be enough for everyone, right?
int m[64] = { -1 };
src = hashtab_search(policy->p_types.table, s);
if (src == NULL) {
fprintf(stderr, "source type %s does not exist\n", s);
return 1;
}
tgt = hashtab_search(policy->p_types.table, targetAttribute);
if (tgt == NULL) {
fprintf(stderr, "target type %s does not exist\n", targetAttribute);
return 1;
}
if(tgt->flavor != TYPE_ATTRIB)
exit(1);
for(int i=0; minusses && minusses[i]; ++i) {
type_datum_t *obj;
obj = hashtab_search(policy->p_types.table, minusses[i]);
if (obj == NULL) {
fprintf(stderr, "minus type %s does not exist\n", minusses[i]);
return 1;
}
m[i] = obj->s.value-1;
m[i+1] = -1;
}
cls = hashtab_search(policy->p_classes.table, c);
if (cls == NULL) {
fprintf(stderr, "class %s does not exist\n", c);
return 1;
}
perm = hashtab_search(cls->permissions.table, p);
if (perm == NULL) {
if (cls->comdatum == NULL) {
fprintf(stderr, "perm %s does not exist in class %s\n", p, c);
return 1;
}
perm = hashtab_search(cls->comdatum->permissions.table, p);
if (perm == NULL) {
fprintf(stderr, "perm %s does not exist in class %s\n", p, c);
return 1;
}
}
ebitmap_node_t *node;
int i;
int ret = 0;
ebitmap_for_each_bit(&policy->attr_type_map[tgt->s.value-1], node, i) {
if(ebitmap_node_get_bit(node, i)) {
int found = 0;
for(int j=0; m[j] != -1; ++j) {
if(i == m[j])
found = 1;
}
if(!found)
ret |= add_irule(src->s.value, i+1, cls->s.value, perm->s.value, effect, not);
}
}
return ret;
}
int add_transition(char *srcS, char *origS, char *tgtS, char *c) {
type_datum_t *src, *tgt, *orig;
class_datum_t *cls;
avtab_datum_t *av;
avtab_key_t key;
src = hashtab_search(policy->p_types.table, srcS);
if (src == NULL) {
fprintf(stderr, "source type %s does not exist\n", srcS);
return 1;
}
tgt = hashtab_search(policy->p_types.table, tgtS);
if (tgt == NULL) {
fprintf(stderr, "target type %s does not exist\n", tgtS);
return 1;
}
cls = hashtab_search(policy->p_classes.table, c);
if (cls == NULL) {
fprintf(stderr, "class %s does not exist\n", c);
return 1;
}
orig = hashtab_search(policy->p_types.table, origS);
if (cls == NULL) {
fprintf(stderr, "class %s does not exist\n", origS);
return 1;
}
key.source_type = src->s.value;
key.target_type = orig->s.value;
key.target_class = cls->s.value;
key.specified = AVTAB_TRANSITION;
av = avtab_search(&policy->te_avtab, &key);
if (av == NULL) {
av = cmalloc(sizeof(*av));
av->data = tgt->s.value;
int ret = avtab_insert(&policy->te_avtab, &key, av);
if (ret) {
fprintf(stderr, "Error inserting into avtab\n");
return 1;
}
} else {
fprintf(stderr, "Warning, rule already defined! Won't override.\n");
fprintf(stderr, "Previous value = %d, wanted value = %d\n", av->data, tgt->s.value);
}
return 0;
}
int add_file_transition(char *srcS, char *origS, char *tgtS, char *c, char* filename) {
type_datum_t *src, *tgt, *orig;
class_datum_t *cls;
src = hashtab_search(policy->p_types.table, srcS);
if (src == NULL) {
fprintf(stderr, "source type %s does not exist\n", srcS);
return 1;
}
tgt = hashtab_search(policy->p_types.table, tgtS);
if (tgt == NULL) {
fprintf(stderr, "target type %s does not exist\n", tgtS);
return 1;
}
cls = hashtab_search(policy->p_classes.table, c);
if (cls == NULL) {
fprintf(stderr, "class %s does not exist\n", c);
return 1;
}
orig = hashtab_search(policy->p_types.table, origS);
if (cls == NULL) {
fprintf(stderr, "class %s does not exist\n", origS);
return 1;
}
filename_trans_t *new_transition = cmalloc(sizeof(*new_transition));
new_transition->stype = src->s.value;
new_transition->ttype = orig->s.value;
new_transition->tclass = cls->s.value;
new_transition->otype = tgt->s.value;
new_transition->name = strdup(filename);
new_transition->next = policy->filename_trans;
policy->filename_trans = new_transition;
return 0;
}
int add_type(char *domainS, char *typeS) {
type_datum_t *domain;
domain = hashtab_search(policy->p_types.table, domainS);
if (domain == NULL) {
fprintf(stderr, "source type %s does not exist\n", domainS);
return 1;
}
set_attr(typeS, domain->s.value);
int typeId = get_attr_id(typeS);
//Now let's update all constraints!
//(kernel doesn't support (yet?) type_names rules)
for(int i=0; i<policy->p_classes.nprim; ++i) {
class_datum_t *cl = policy->class_val_to_struct[i];
for(constraint_node_t *n = cl->constraints; n ; n=n->next) {
for(constraint_expr_t *e = n->expr; e; e=e->next) {
if(e->expr_type == CEXPR_NAMES) {
if(ebitmap_get_bit(&e->type_names->types, typeId-1)) {
ebitmap_set_bit(&e->names, domain->s.value-1, 1);
}
}
}
}
}
return 0;
}
int add_rule(char *s, char *t, char *c, char *p, int effect, int not) {
type_datum_t *src = NULL, *tgt = NULL;
class_datum_t *cls = NULL;
perm_datum_t *perm = NULL;
if (s) {
src = hashtab_search(policy->p_types.table, s);
if (src == NULL) {
fprintf(stderr, "source type %s does not exist\n", s);
return 1;
}
}
if (t) {
tgt = hashtab_search(policy->p_types.table, t);
if (tgt == NULL) {
fprintf(stderr, "target type %s does not exist\n", t);
return 1;
}
}
if (c) {
cls = hashtab_search(policy->p_classes.table, c);
if (cls == NULL) {
fprintf(stderr, "class %s does not exist\n", c);
return 1;
}
}
if (p) {
if (c == NULL) {
fprintf(stderr, "No class is specified, cannot add perm [%s] \n", p);
return 1;
}
if (cls != NULL) {
perm = hashtab_search(cls->permissions.table, p);
if (perm == NULL && cls->comdatum != NULL) {
perm = hashtab_search(cls->comdatum->permissions.table, p);
}
if (perm == NULL) {
fprintf(stderr, "perm %s does not exist in class %s\n", p, c);
return 1;
}
}
}
return add_rule_auto(src, tgt, cls, perm, effect, not);
}
int live_patch() {
char *filename = "/sys/fs/selinux/load";
int fd, ret;
void *data = NULL;
size_t len;
policydb_to_image(NULL, policy, &data, &len);
if (data == NULL) fprintf(stderr, "Error!");
// based on libselinux security_load_policy()
fd = open(filename, O_RDWR);
if (fd < 0) {
fprintf(stderr, "Can't open '%s': %s\n",
filename, strerror(errno));
return 1;
}
ret = write(fd, data, len);
close(fd);
if (ret < 0) {
fprintf(stderr, "Could not write policy to %s\n",
filename);
return 1;
}
return 0;
}