bus: add basic implementation of a native bus client library

[elogind.git] / src / libsystemd-bus / bus-signature.c

diff --git a/src/libsystemd-bus/bus-signature.c b/src/libsystemd-bus/bus-signature.c
new file mode 100644 (file)
index 0000000..db95c88
--- /dev/null
+++ b/src/libsystemd-bus/bus-signature.c
@@ -0,0 +1,141 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+/***
+  This file is part of systemd.
+
+  Copyright 2013 Lennart Poettering
+
+  systemd is free software; you can redistribute it and/or modify it
+  under the terms of the GNU Lesser General Public License as published by
+  the Free Software Foundation; either version 2.1 of the License, or
+  (at your option) any later version.
+
+  systemd is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include <util.h>
+
+#include "bus-signature.h"
+#include "bus-type.h"
+
+static int signature_element_length_internal(
+                const char *s,
+                bool allow_dict_entry,
+                size_t *l) {
+
+        int r;
+
+        assert(s);
+
+        if (bus_type_is_basic(*s) || *s == SD_BUS_TYPE_VARIANT) {
+                *l = 1;
+                return 0;
+        }
+
+        if (*s == SD_BUS_TYPE_ARRAY) {
+                size_t t;
+
+                r = signature_element_length_internal(s + 1, true, &t);
+                if (r < 0)
+                        return r;
+
+                *l = t + 1;
+                return 0;
+        }
+
+        if (*s == SD_BUS_TYPE_STRUCT_BEGIN) {
+                const char *p = s + 1;
+
+                while (*p != SD_BUS_TYPE_STRUCT_END) {
+                        size_t t;
+
+                        r = signature_element_length_internal(p, false, &t);
+                        if (r < 0)
+                                return r;
+
+                        p += t;
+                }
+
+                *l = p - s + 1;
+                return 0;
+        }
+
+        if (*s == SD_BUS_TYPE_DICT_ENTRY_BEGIN && allow_dict_entry) {
+                const char *p = s + 1;
+                unsigned n = 0;
+
+                while (*p != SD_BUS_TYPE_DICT_ENTRY_END) {
+                        size_t t;
+
+                        if (n == 0 && !bus_type_is_basic(*p))
+                                return -EINVAL;
+
+                        r = signature_element_length_internal(p, false, &t);
+                        if (r < 0)
+                                return r;
+
+                        p += t;
+                        n++;
+                }
+
+                if (n != 2)
+                        return -EINVAL;
+
+                *l = p - s + 1;
+                return 0;
+        }
+
+        return -EINVAL;
+}
+
+bool signature_is_single(const char *s) {
+        int r;
+        size_t t;
+
+        assert(s);
+
+        r = signature_element_length(s, &t);
+        if (r < 0)
+                return false;
+
+        return s[t] == 0;
+}
+
+bool signature_is_pair(const char *s) {
+        assert(s);
+
+        if (!bus_type_is_basic(*s))
+                return false;
+
+        return signature_is_single(s + 1);
+}
+
+bool signature_is_valid(const char *s, bool allow_dict_entry) {
+        const char *p;
+        int r;
+
+        assert(s);
+
+        p = s;
+        while (*p) {
+                size_t t;
+
+                r = signature_element_length_internal(p, allow_dict_entry, &t);
+                if (r < 0)
+                        return false;
+
+                p += t;
+        }
+
+        return p - s <= 255;
+}
+
+int signature_element_length(const char *s, size_t *l) {
+        return signature_element_length_internal(s, true, l);
+}