From 6d1b59cec4d96d037414e1bf35141e875688b57c Mon Sep 17 00:00:00 2001
From: Yu Watanabe <watanabe.yu+github@gmail.com>
Date: Tue, 7 Dec 2021 23:32:50 +0900
Subject: [PATCH] network/netdev: introduce link_get_local_address()

It will be used in later commits.
---
 src/network/meson.build          |  2 +
 src/network/netdev/netdev-util.c | 97 ++++++++++++++++++++++++++++++++
 src/network/netdev/netdev-util.h | 27 +++++++++
 3 files changed, 126 insertions(+)
 create mode 100644 src/network/netdev/netdev-util.c
 create mode 100644 src/network/netdev/netdev-util.h

diff --git a/src/network/meson.build b/src/network/meson.build
index 04a5f966bb7..15b72557a8d 100644
--- a/src/network/meson.build
+++ b/src/network/meson.build
@@ -20,6 +20,8 @@ sources = files('''
         netdev/macvlan.c
         netdev/macvlan.h
         netdev/netdev.c
+        netdev/netdev-util.c
+        netdev/netdev-util.h
         netdev/netdev.h
         netdev/nlmon.c
         netdev/nlmon.h
diff --git a/src/network/netdev/netdev-util.c b/src/network/netdev/netdev-util.c
new file mode 100644
index 00000000000..00d9e174ded
--- /dev/null
+++ b/src/network/netdev/netdev-util.c
@@ -0,0 +1,97 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+
+#include "netdev-util.h"
+#include "networkd-address.h"
+#include "networkd-link.h"
+#include "string-table.h"
+
+static const char * const netdev_local_address_type_table[_NETDEV_LOCAL_ADDRESS_TYPE_MAX] = {
+        [NETDEV_LOCAL_ADDRESS_IPV4LL]  = "ipv4_link_local",
+        [NETDEV_LOCAL_ADDRESS_IPV6LL]  = "ipv6_link_local",
+        [NETDEV_LOCAL_ADDRESS_DHCP4]   = "dhcp4",
+        [NETDEV_LOCAL_ADDRESS_DHCP6]   = "dhcp6",
+        [NETDEV_LOCAL_ADDRESS_SLAAC]   = "slaac",
+};
+
+DEFINE_STRING_TABLE_LOOKUP(netdev_local_address_type, NetDevLocalAddressType);
+
+int link_get_local_address(
+                Link *link,
+                NetDevLocalAddressType type,
+                int family,
+                int *ret_family,
+                union in_addr_union *ret_address) {
+
+        Address *a;
+
+        assert(link);
+
+        switch (type) {
+        case NETDEV_LOCAL_ADDRESS_IPV4LL:
+                assert(IN_SET(family, AF_UNSPEC, AF_INET));
+                family = AF_INET;
+                break;
+        case NETDEV_LOCAL_ADDRESS_IPV6LL:
+                assert(IN_SET(family, AF_UNSPEC, AF_INET6));
+                family = AF_INET6;
+                break;
+        case NETDEV_LOCAL_ADDRESS_DHCP4:
+                assert(IN_SET(family, AF_UNSPEC, AF_INET));
+                family = AF_INET;
+                break;
+        case NETDEV_LOCAL_ADDRESS_DHCP6:
+                assert(IN_SET(family, AF_UNSPEC, AF_INET6));
+                family = AF_INET6;
+                break;
+        case NETDEV_LOCAL_ADDRESS_SLAAC:
+                assert(IN_SET(family, AF_UNSPEC, AF_INET6));
+                family = AF_INET6;
+                break;
+        default:
+                assert_not_reached();
+        }
+
+        SET_FOREACH(a, link->addresses) {
+                if (!address_exists(a))
+                        continue;
+
+                if (a->family != family)
+                        continue;
+
+                if (in_addr_is_set(a->family, &a->in_addr_peer))
+                        continue;
+
+                switch (type) {
+                case NETDEV_LOCAL_ADDRESS_IPV4LL:
+                        if (a->source != NETWORK_CONFIG_SOURCE_IPV4LL)
+                                continue;
+                        break;
+                case NETDEV_LOCAL_ADDRESS_IPV6LL:
+                        if (!in6_addr_is_link_local(&a->in_addr.in6))
+                                continue;
+                        break;
+                case NETDEV_LOCAL_ADDRESS_DHCP4:
+                        if (a->source != NETWORK_CONFIG_SOURCE_DHCP4)
+                                continue;
+                        break;
+                case NETDEV_LOCAL_ADDRESS_DHCP6:
+                        if (a->source != NETWORK_CONFIG_SOURCE_DHCP6)
+                                continue;
+                        break;
+                case NETDEV_LOCAL_ADDRESS_SLAAC:
+                        if (a->source != NETWORK_CONFIG_SOURCE_NDISC)
+                                continue;
+                        break;
+                default:
+                        assert_not_reached();
+                }
+
+                if (ret_family)
+                        *ret_family = a->family;
+                if (ret_address)
+                        *ret_address = a->in_addr;
+                return 1;
+        }
+
+        return -ENXIO;
+}
diff --git a/src/network/netdev/netdev-util.h b/src/network/netdev/netdev-util.h
new file mode 100644
index 00000000000..02b07e3670b
--- /dev/null
+++ b/src/network/netdev/netdev-util.h
@@ -0,0 +1,27 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+#pragma once
+
+#include "in-addr-util.h"
+#include "macro.h"
+
+typedef struct Link Link;
+
+typedef enum NetDevLocalAddressType {
+        NETDEV_LOCAL_ADDRESS_IPV4LL,
+        NETDEV_LOCAL_ADDRESS_IPV6LL,
+        NETDEV_LOCAL_ADDRESS_DHCP4,
+        NETDEV_LOCAL_ADDRESS_DHCP6,
+        NETDEV_LOCAL_ADDRESS_SLAAC,
+        _NETDEV_LOCAL_ADDRESS_TYPE_MAX,
+        _NETDEV_LOCAL_ADDRESS_TYPE_INVALID = -EINVAL,
+} NetDevLocalAddressType;
+
+const char *netdev_local_address_type_to_string(NetDevLocalAddressType t) _const_;
+NetDevLocalAddressType netdev_local_address_type_from_string(const char *s) _pure_;
+
+int link_get_local_address(
+                Link *link,
+                NetDevLocalAddressType type,
+                int family,
+                int *ret_family,
+                union in_addr_union *ret_address);
-- 
2.47.3