+
+static bool
+rpc_login_test_password(const char *hash, const char *password)
+{
+ char *crypt_hash;
+
+ /* password is not set */
+ if (!hash || !*hash || !strcmp(hash, "!") || !strcmp(hash, "x"))
+ {
+ return true;
+ }
+
+ /* password hash refers to shadow/passwd */
+ else if (!strncmp(hash, "$p$", 3))
+ {
+#ifdef HAVE_SHADOW
+ struct spwd *sp = getspnam(hash + 3);
+
+ if (!sp)
+ return false;
+
+ return rpc_login_test_password(sp->sp_pwdp, password);
+#else
+ struct passwd *pw = getpwnam(hash + 3);
+
+ if (!pw)
+ return false;
+
+ return rpc_login_test_password(pw->pw_passwd, password);
+#endif
+ }
+
+ crypt_hash = crypt(password, hash);
+
+ return !strcmp(crypt_hash, hash);
+}
+
+static struct uci_section *
+rpc_login_test_login(struct uci_context *uci,
+ const char *username, const char *password)
+{
+ struct uci_package *p = NULL;
+ struct uci_section *s;
+ struct uci_element *e;
+ struct uci_ptr ptr = { .package = "rpcd" };
+
+ uci_load(uci, ptr.package, &p);
+
+ if (!p)
+ return false;
+
+ uci_foreach_element(&p->sections, e)
+ {
+ s = uci_to_section(e);
+
+ if (strcmp(s->type, "login"))
+ continue;
+
+ ptr.section = s->e.name;
+ ptr.s = NULL;
+
+ /* test for matching username */
+ ptr.option = "username";
+ ptr.o = NULL;
+
+ if (uci_lookup_ptr(uci, &ptr, NULL, true))
+ continue;
+
+ if (ptr.o->type != UCI_TYPE_STRING)
+ continue;
+
+ if (strcmp(ptr.o->v.string, username))
+ continue;
+
+ /* If password is NULL, we're restoring ACLs for an existing session,
+ * in this case do not check the password again. */
+ if (!password)
+ return ptr.s;
+
+ /* test for matching password */
+ ptr.option = "password";
+ ptr.o = NULL;
+
+ if (uci_lookup_ptr(uci, &ptr, NULL, true))
+ continue;
+
+ if (ptr.o->type != UCI_TYPE_STRING)
+ continue;
+
+ if (rpc_login_test_password(ptr.o->v.string, password))
+ return ptr.s;
+ }
+
+ return NULL;
+}
+
+static bool
+rpc_login_test_permission(struct uci_section *s,
+ const char *perm, const char *group)
+{
+ const char *p;
+ struct uci_option *o;
+ struct uci_element *e, *l;
+
+ /* If the login section is not provided, we're setting up acls for the
+ * default session, in this case uncondionally allow access to the
+ * "unauthenticated" access group */
+ if (!s) {
+ return !strcmp(group, "unauthenticated");
+ }
+
+ uci_foreach_element(&s->options, e)
+ {
+ o = uci_to_option(e);
+
+ if (o->type != UCI_TYPE_LIST)
+ continue;
+
+ if (strcmp(o->e.name, perm))
+ continue;
+
+ /* Match negative expressions first. If a negative expression matches
+ * the current group name then deny access. */
+ uci_foreach_element(&o->v.list, l) {
+ p = l->name;
+
+ if (!p || *p != '!')
+ continue;
+
+ while (isspace(*++p));
+
+ if (!*p)
+ continue;
+
+ if (!fnmatch(p, group, 0))
+ return false;
+ }
+
+ uci_foreach_element(&o->v.list, l) {
+ if (!l->name || !*l->name || *l->name == '!')
+ continue;
+
+ if (!fnmatch(l->name, group, 0))
+ return true;
+ }
+ }
+
+ /* make sure that write permission implies read permission */
+ if (!strcmp(perm, "read"))
+ return rpc_login_test_permission(s, "write", group);
+
+ return false;
+}
+
+static void
+rpc_login_setup_acl_scope(struct rpc_session *ses,
+ struct blob_attr *acl_perm,
+ struct blob_attr *acl_scope)
+{
+ struct blob_attr *acl_obj, *acl_func;
+ int rem, rem2;
+
+ /*
+ * Parse ACL scopes in table notation.
+ *
+ * "<scope>": {
+ * "<object>": [
+ * "<function>",
+ * "<function>",
+ * ...
+ * ]
+ * }
+ */
+ if (blobmsg_type(acl_scope) == BLOBMSG_TYPE_TABLE) {
+ blobmsg_for_each_attr(acl_obj, acl_scope, rem) {
+ if (blobmsg_type(acl_obj) != BLOBMSG_TYPE_ARRAY)
+ continue;
+
+ blobmsg_for_each_attr(acl_func, acl_obj, rem2) {
+ if (blobmsg_type(acl_func) != BLOBMSG_TYPE_STRING)
+ continue;
+
+ rpc_session_grant(ses, blobmsg_name(acl_scope),
+ blobmsg_name(acl_obj),
+ blobmsg_data(acl_func));
+ }
+ }
+ }
+
+ /*
+ * Parse ACL scopes in array notation. The permission ("read" or "write")
+ * will be used as function name for each object.
+ *
+ * "<scope>": [
+ * "<object>",
+ * "<object>",
+ * ...
+ * ]
+ */
+ else if (blobmsg_type(acl_scope) == BLOBMSG_TYPE_ARRAY) {
+ blobmsg_for_each_attr(acl_obj, acl_scope, rem) {
+ if (blobmsg_type(acl_obj) != BLOBMSG_TYPE_STRING)
+ continue;
+
+ rpc_session_grant(ses, blobmsg_name(acl_scope),
+ blobmsg_data(acl_obj),
+ blobmsg_name(acl_perm));
+ }
+ }
+}
+
+static void
+rpc_login_setup_acl_file(struct rpc_session *ses, struct uci_section *login,
+ const char *path)
+{
+ struct blob_buf acl = { 0 };
+ struct blob_attr *acl_group, *acl_perm, *acl_scope;
+ int rem, rem2, rem3;
+
+ blob_buf_init(&acl, 0);
+
+ if (!blobmsg_add_json_from_file(&acl, path)) {
+ fprintf(stderr, "Failed to parse %s\n", path);
+ goto out;
+ }
+
+ /* Iterate access groups in toplevel object */
+ blob_for_each_attr(acl_group, acl.head, rem) {
+ /* Iterate permission objects in each access group object */
+ blobmsg_for_each_attr(acl_perm, acl_group, rem2) {
+ if (blobmsg_type(acl_perm) != BLOBMSG_TYPE_TABLE)
+ continue;
+
+ /* Only "read" and "write" permissions are defined */
+ if (strcmp(blobmsg_name(acl_perm), "read") &&
+ strcmp(blobmsg_name(acl_perm), "write"))
+ continue;
+
+ /*
+ * Check if the current user context specifies the current
+ * "read" or "write" permission in the given access group.
+ */
+ if (!rpc_login_test_permission(login, blobmsg_name(acl_perm),
+ blobmsg_name(acl_group)))
+ continue;
+
+ /* Iterate scope objects within the permission object */
+ blobmsg_for_each_attr(acl_scope, acl_perm, rem3) {
+ /* Setup the scopes of the access group */
+ rpc_login_setup_acl_scope(ses, acl_perm, acl_scope);
+
+ /*
+ * Add the access group itself as object to the "access-group"
+ * meta scope and the the permission level ("read" or "write")
+ * as function, so
+ * "<group>": {
+ * "<permission>": {
+ * "<scope>": ...
+ * }
+ * }
+ * becomes
+ * "access-group": {
+ * "<group>": [
+ * "<permission>"
+ * ]
+ * }
+ *
+ * This allows session clients to easily query the allowed
+ * access groups without having to test access of each single
+ * <scope>/<object>/<function> tuple defined in a group.
+ */
+ rpc_session_grant(ses, "access-group",
+ blobmsg_name(acl_group),
+ blobmsg_name(acl_perm));
+ }
+ }
+ }
+
+out:
+ blob_buf_free(&acl);
+}
+
+static void
+rpc_login_setup_acls(struct rpc_session *ses, struct uci_section *login)
+{
+ int i;
+ glob_t gl;
+
+ if (glob(RPC_SESSION_ACL_DIR "/*.json", 0, NULL, &gl))
+ return;
+
+ for (i = 0; i < gl.gl_pathc; i++)
+ rpc_login_setup_acl_file(ses, login, gl.gl_pathv[i]);
+
+ globfree(&gl);
+}
+
+static int
+rpc_handle_login(struct ubus_context *ctx, struct ubus_object *obj,
+ struct ubus_request_data *req, const char *method,
+ struct blob_attr *msg)
+{
+ struct uci_context *uci = NULL;
+ struct uci_section *login;
+ struct rpc_session *ses;
+ struct blob_attr *tb[__RPC_L_MAX];
+ int timeout = RPC_DEFAULT_SESSION_TIMEOUT;
+ int rv = 0;
+
+ blobmsg_parse(login_policy, __RPC_L_MAX, tb, blob_data(msg), blob_len(msg));
+
+ if (!tb[RPC_L_USERNAME] || !tb[RPC_L_PASSWORD]) {
+ rv = UBUS_STATUS_INVALID_ARGUMENT;
+ goto out;
+ }
+
+ uci = uci_alloc_context();
+
+ if (!uci) {
+ rv = UBUS_STATUS_UNKNOWN_ERROR;
+ goto out;
+ }
+
+ login = rpc_login_test_login(uci, blobmsg_get_string(tb[RPC_L_USERNAME]),
+ blobmsg_get_string(tb[RPC_L_PASSWORD]));
+
+ if (!login) {
+ rv = UBUS_STATUS_PERMISSION_DENIED;
+ goto out;
+ }
+
+ if (tb[RPC_L_TIMEOUT])
+ timeout = blobmsg_get_u32(tb[RPC_L_TIMEOUT]);
+
+ ses = rpc_session_create(timeout);
+
+ if (!ses) {
+ rv = UBUS_STATUS_UNKNOWN_ERROR;
+ goto out;
+ }
+
+ rpc_login_setup_acls(ses, login);
+
+ rpc_session_set(ses, "user", tb[RPC_L_USERNAME]);
+ rpc_session_dump(ses, ctx, req);
+
+out:
+ if (uci)
+ uci_free_context(uci);
+
+ return rv;
+}
+
+
+static bool
+rpc_validate_sid(const char *id)
+{
+ if (!id)
+ return false;
+
+ if (strlen(id) != RPC_SID_LEN)
+ return false;
+
+ while (*id)
+ if (!isxdigit(*id++))
+ return false;
+
+ return true;
+}
+
+static int
+rpc_blob_to_file(const char *path, struct blob_attr *attr)
+{
+ int fd, len;
+
+ fd = open(path, O_WRONLY | O_CREAT | O_EXCL, 0600);
+
+ if (fd < 0)
+ return fd;
+
+ len = write(fd, attr, blob_pad_len(attr));
+
+ close(fd);
+
+ if (len != blob_pad_len(attr))
+ {
+ unlink(path);
+ return -1;
+ }
+
+ return len;
+}
+
+static struct blob_attr *
+rpc_blob_from_file(const char *path)
+{
+ int fd = -1, len;
+ struct stat s;
+ struct blob_attr head, *attr = NULL;
+
+ if (stat(path, &s) || !S_ISREG(s.st_mode))
+ return NULL;
+
+ fd = open(path, O_RDONLY);
+
+ if (fd < 0)
+ goto fail;
+
+ len = read(fd, &head, sizeof(head));
+
+ if (len != sizeof(head) || blob_pad_len(&head) != s.st_size)
+ goto fail;
+
+ attr = calloc(1, s.st_size);
+
+ if (!attr)
+ goto fail;
+
+ memcpy(attr, &head, sizeof(head));
+
+ len += read(fd, (char *)attr + sizeof(head), s.st_size - sizeof(head));
+
+ if (len != blob_pad_len(&head))
+ goto fail;
+
+ close(fd);
+
+ return attr;
+
+fail:
+ if (fd >= 0)
+ close(fd);
+
+ if (attr)
+ free(attr);
+
+ return NULL;
+}
+
+static bool
+rpc_session_from_blob(struct uci_context *uci, struct blob_attr *attr)
+{
+ int i, rem;
+ const char *user = NULL;
+ struct rpc_session *ses;
+ struct uci_section *login;
+ struct blob_attr *tb[__RPC_DUMP_MAX], *data;
+
+ blobmsg_parse(dump_policy, __RPC_DUMP_MAX, tb,
+ blob_data(attr), blob_len(attr));
+
+ for (i = 0; i < __RPC_DUMP_MAX; i++)
+ if (!tb[i])
+ return false;
+
+ ses = rpc_session_new();
+
+ if (!ses)
+ return false;
+
+ memcpy(ses->id, blobmsg_data(tb[RPC_DUMP_SID]), RPC_SID_LEN);
+
+ ses->timeout = blobmsg_get_u32(tb[RPC_DUMP_TIMEOUT]);
+
+ blobmsg_for_each_attr(data, tb[RPC_DUMP_DATA], rem) {
+ rpc_session_set(ses, blobmsg_name(data), data);
+
+ if (!strcmp(blobmsg_name(data), "username"))
+ user = blobmsg_get_string(data);
+ }
+
+ if (uci && user) {
+ login = rpc_login_test_login(uci, user, NULL);
+ if (login)
+ rpc_login_setup_acls(ses, login);
+ }
+
+ avl_insert(&sessions, &ses->avl);
+
+ uloop_timeout_set(&ses->t, blobmsg_get_u32(tb[RPC_DUMP_EXPIRES]) * 1000);
+
+ return true;
+}
+