util: introduce helper functions to read in_addr from bus message

src/shared/bus-message-util.c

@@ -0,0 +1,50 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include "bus-message-util.h"
+
+int bus_message_read_family(sd_bus_message *message, sd_bus_error *error, int *ret) {
+        int family, r;
+
+        assert(message);
+        assert(ret);
+
+        assert_cc(sizeof(int) == sizeof(int32_t));
+
+        r = sd_bus_message_read(message, "i", &family);
+        if (r < 0)
+                return r;
+
+        if (!IN_SET(family, AF_INET, AF_INET6))
+                return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Unknown address family %i", family);
+
+        *ret = family;
+        return 0;
+}
+
+int bus_message_read_in_addr_auto(sd_bus_message *message, sd_bus_error *error, int *ret_family, union in_addr_union *ret_addr) {
+        int family, r;
+        const void *d;
+        size_t sz;
+
+        assert(message);
+
+        r = sd_bus_message_read(message, "i", &family);
+        if (r < 0)
+                return r;
+
+        r = sd_bus_message_read_array(message, 'y', &d, &sz);
+        if (r < 0)
+                return r;
+
+        if (!IN_SET(family, AF_INET, AF_INET6))
+                return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Unknown address family %i", family);
+
+        if (sz != FAMILY_ADDRESS_SIZE(family))
+                return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Invalid address size");
+
+        if (ret_family)
+                *ret_family = family;
+        if (ret_addr)
+                memcpy(ret_addr, d, sz);
+        return 0;
+}

src/shared/bus-message-util.h

@@ -0,0 +1,9 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include "sd-bus.h"
+
+#include "in-addr-util.h"
+
+int bus_message_read_family(sd_bus_message *message, sd_bus_error *error, int *ret);
+int bus_message_read_in_addr_auto(sd_bus_message *message, sd_bus_error *error, int *ret_family, union in_addr_union *ret_addr);

src/shared/meson.build

@@ -35,6 +35,8 @@ shared_sources = files('''
         bus-log-control-api.h
         bus-map-properties.c
         bus-map-properties.h
+        bus-message-util.c
+        bus-message-util.h
         bus-object.c
         bus-object.h
         bus-polkit.c