Author: Ken Zhu <guigenz@codeaurora.org>
Date:   Thu Dec 17 09:08:39 2020 -0800

    netifd: fix ip lost after dhcp renew

    When two more IPv4 addresses of the same subnetwork are assigned
    to one device, if the primary address got deleted, the rest IP
    addresses could be deleted as well.

    To make sure that old IPv4 address deleted before assigning the
    new address, both of them  must be proceeded in one time.

    Change-Id: Ib989955c1511a14d34a5a45df1ad7e8713815b42
    Signed-off-by: Ken Zhu <guigenz@codeaurora.org>

diff -Nur a/interface-ip.c netifd-2019-08-05-5e02f944/interface-ip.c
--- a/interface-ip.c	2021-01-26 13:08:43.624405844 -0800
+++ netifd-2019-08-05-5e02f944/interface-ip.c	2021-01-26 13:11:14.935635800 -0800
@@ -509,9 +509,23 @@
 	free(route);
 }
 
+/*
+ * addr_cmp
+ *  return 0 if two ipv6 addresses and its netmask are same
+ *  return 0 if two ipv4 addresses are in the same subnetwork.
+ */
 static int
 addr_cmp(const void *k1, const void *k2, void *ptr)
 {
+	struct device_addr *addr1, *addr2;
+	addr1 = container_of(k1, struct device_addr, flags);
+	addr2 = container_of(k2, struct device_addr, flags);
+	if (((addr1->flags & DEVADDR_FAMILY) == DEVADDR_INET4)
+			&& ((addr2->flags & DEVADDR_FAMILY) == DEVADDR_INET4)) {
+		return (ntohl(addr1->addr.in.s_addr) & (~((1 << (32 - addr1->mask)) - 1))) !=
+			(ntohl(addr2->addr.in.s_addr) & (~((1 << (32 - addr2->mask)) - 1)));
+	}
+
 	return memcmp(k1, k2, sizeof(struct device_addr) -
 		      offsetof(struct device_addr, flags));
 }
@@ -662,6 +676,7 @@
 
 		if (((a_new->flags & DEVADDR_FAMILY) == DEVADDR_INET4) &&
 		     (a_new->broadcast != a_old->broadcast ||
+		      a_new->addr.in.s_addr != a_old->addr.in.s_addr ||
 		      a_new->point_to_point != a_old->point_to_point))
 			keep = false;
 	}