From f29b6b371e39acc3c9028231a4fdcb8e8ee7d2b5 Mon Sep 17 00:00:00 2001
From: Yu Watanabe <watanabe.yu+github@gmail.com>
Date: Tue, 29 Sep 2020 22:34:37 +0900
Subject: [PATCH] sd-netlink: introduce netlink_message_read_in_addr_union()

---
 src/libsystemd/sd-netlink/netlink-message.c | 37 +++++++++++----------
 src/libsystemd/sd-netlink/netlink-util.h    |  2 ++
 2 files changed, 21 insertions(+), 18 deletions(-)

diff --git a/src/libsystemd/sd-netlink/netlink-message.c b/src/libsystemd/sd-netlink/netlink-message.c
index d6bf31efc7..0d9a57ee9e 100644
--- a/src/libsystemd/sd-netlink/netlink-message.c
+++ b/src/libsystemd/sd-netlink/netlink-message.c
@@ -862,11 +862,12 @@ int sd_netlink_message_read_cache_info(sd_netlink_message *m, unsigned short typ
         return 0;
 }
 
-int sd_netlink_message_read_in_addr(sd_netlink_message *m, unsigned short type, struct in_addr *data) {
-        int r;
+int netlink_message_read_in_addr_union(sd_netlink_message *m, unsigned short type, int family, union in_addr_union *data) {
         void *attr_data;
+        int r;
 
         assert_return(m, -EINVAL);
+        assert_return(IN_SET(family, AF_INET, AF_INET6), -EINVAL);
 
         r = message_attribute_has_type(m, NULL, type, NETLINK_TYPE_IN_ADDR);
         if (r < 0)
@@ -875,35 +876,35 @@ int sd_netlink_message_read_in_addr(sd_netlink_message *m, unsigned short type,
         r = netlink_message_read_internal(m, type, &attr_data, NULL);
         if (r < 0)
                 return r;
-        else if ((size_t) r < sizeof(struct in_addr))
+        else if ((size_t) r < FAMILY_ADDRESS_SIZE(family))
                 return -EIO;
 
         if (data)
-                memcpy(data, attr_data, sizeof(struct in_addr));
+                memcpy(data, attr_data, FAMILY_ADDRESS_SIZE(family));
 
         return 0;
 }
 
-int sd_netlink_message_read_in6_addr(sd_netlink_message *m, unsigned short type, struct in6_addr *data) {
+int sd_netlink_message_read_in_addr(sd_netlink_message *m, unsigned short type, struct in_addr *data) {
+        union in_addr_union u;
         int r;
-        void *attr_data;
 
-        assert_return(m, -EINVAL);
+        r = netlink_message_read_in_addr_union(m, type, AF_INET, &u);
+        if (r >= 0 && data)
+                *data = u.in;
 
-        r = message_attribute_has_type(m, NULL, type, NETLINK_TYPE_IN_ADDR);
-        if (r < 0)
-                return r;
+        return r;
+}
 
-        r = netlink_message_read_internal(m, type, &attr_data, NULL);
-        if (r < 0)
-                return r;
-        else if ((size_t) r < sizeof(struct in6_addr))
-                return -EIO;
+int sd_netlink_message_read_in6_addr(sd_netlink_message *m, unsigned short type, struct in6_addr *data) {
+        union in_addr_union u;
+        int r;
 
-        if (data)
-                memcpy(data, attr_data, sizeof(struct in6_addr));
+        r = netlink_message_read_in_addr_union(m, type, AF_INET6, &u);
+        if (r >= 0 && data)
+                *data = u.in6;
 
-        return 0;
+        return r;
 }
 
 int sd_netlink_message_read_strv(sd_netlink_message *m, unsigned short container_type, unsigned short type_id, char ***ret) {
diff --git a/src/libsystemd/sd-netlink/netlink-util.h b/src/libsystemd/sd-netlink/netlink-util.h
index 8e99cd451d..fa17e7dae7 100644
--- a/src/libsystemd/sd-netlink/netlink-util.h
+++ b/src/libsystemd/sd-netlink/netlink-util.h
@@ -90,5 +90,7 @@ int rtnl_log_create_error(int r);
 int netlink_message_append_in_addr_union(sd_netlink_message *m, unsigned short type, int family, const union in_addr_union *data);
 int netlink_message_append_sockaddr_union(sd_netlink_message *m, unsigned short type, const union sockaddr_union *data);
 
+int netlink_message_read_in_addr_union(sd_netlink_message *m, unsigned short type, int family, union in_addr_union *data);
+
 void rtattr_append_attribute_internal(struct rtattr *rta, unsigned short type, const void *data, size_t data_length);
 int rtattr_append_attribute(struct rtattr **rta, unsigned short type, const void *data, size_t data_length);