networkd: smooth transition from ipv4ll to dhcp address

Currently when both ipv4ll and dhcp are enabled, ipv4ll
address (if one has been claimed) is removed when dhcp
address is aquired. This is not the best thing to do
since there might be clients unaware of the removal
trying to communicate.

This patch provides a smooth transition between ipv4ll
and dhcp. If ipv4ll address was claimed [1] before dhcp,
address is marked as deprecated. Deprecated address is still
a valid address and packets can be received on it but address
cannot be selected as a source address. If dhcp lease cannot
be extended, then ipv4ll address is marked as valid again.

[1] If there is no collision, claiming IPv4LL takes between 4 to
7 seconds.

1 files changed, 2 insertions, 0 deletions

diff --git a/src/libsystemd/sd-rtnl/test-rtnl.c b/src/libsystemd/sd-rtnl/test-rtnl.c
index 44369628f4..529231a70a 100644
--- a/src/libsystemd/sd-rtnl/test-rtnl.c
+++ b/src/libsystemd/sd-rtnl/test-rtnl.c
@@ -106,6 +106,7 @@ static void test_address_get(sd_rtnl *rtnl, int ifindex) {
         sd_rtnl_message *m;
         sd_rtnl_message *r;
         struct in_addr in_data;
+        struct ifa_cacheinfo cache;
         char *label;
 
         assert_se(sd_rtnl_message_new_addr(rtnl, &m, RTM_GETADDR, ifindex, AF_INET) >= 0);
@@ -116,6 +117,7 @@ static void test_address_get(sd_rtnl *rtnl, int ifindex) {
         assert_se(sd_rtnl_message_read_in_addr(r, IFA_LOCAL, &in_data) == 0);
         assert_se(sd_rtnl_message_read_in_addr(r, IFA_ADDRESS, &in_data) == 0);
         assert_se(sd_rtnl_message_read_string(r, IFA_LABEL, &label) == 0);
+        assert_se(sd_rtnl_message_read_cache_info(r, IFA_CACHEINFO, &cache) == 0);
 
         assert_se(sd_rtnl_flush(rtnl) >= 0);
         assert_se((m = sd_rtnl_message_unref(m)) == NULL);