dhcpcd-discuss

I am using ubuntu/debian variant of dhcpcd 7.1.0 patched with
https://roy.marples.name/cgit/dhcpcd.git/commit/?h=dhcpcd-7&id=75f2832a88b8f5a3078179404b149b7cd9623dbf
https://roy.marples.name/cgit/dhcpcd.git/commit/?h=dhcpcd-7&id=8d7414a6d80f54ca82887e3dbb05fed9b568a9a8

Most of the time, dhcpcd worked without issue and the route will be added
successfully. However, sometimes the interface will be stuck at waiting for
IP address, while the address is already added. I've managed to trace the
problem down to the cause being dhcpcd process the netlink event first
(link_addr function) and ignore the address which interface doesn't exist
in ctx->ifaces, then only the link being added afterwards. Refer to the
following syslog:
Jan  8 13:56:32 QNE dhcpcd: NM dhcpcd callback by PREINIT for ppp-eno2
completed with rc: 0
Jan  8 13:56:32 QNE dhcpcd[9021]: ppp-eno2: IAID 00:00:00:eb
Jan  8 13:56:32 QNE dhcpcd[9021]: ppp-eno2: waiting for 3rd party to
configure IP address
My thoughts of a possible simple fix for this is simply to let new
interface discover it's addresses immediately. Refer to the attachment for
my suggestion to patch the issue. Is there any better way or any other
suggestions to handle this issue? Thanks!

diff --git a/src/dhcpcd.c b/src/dhcpcd.c
index 8f2c38a..e6c57de 100644
--- a/src/dhcpcd.c
+++ b/src/dhcpcd.c
@@ -1031,7 +1031,6 @@ dhcpcd_handleinterface(void *arg, int action, const char *ifname)
 		if (ifp->hwlen != 0)
 			memcpy(iff->hwaddr, ifp->hwaddr, iff->hwlen);
 	} else {
-		TAILQ_REMOVE(ifs, ifp, next);
 		TAILQ_INSERT_TAIL(ctx->ifaces, ifp, next);
 		if (ifp->active) {
 			logdebugx("%s: interface added", ifp->name);
@@ -1047,6 +1046,9 @@ dhcpcd_handleinterface(void *arg, int action, const char *ifname)
 			dhcpcd_prestartinterface(iff);
 	}
 
+	if (iff == ifp)
+		TAILQ_REMOVE(ifs, ifp, next);
+
 	/* Free our discovered list */
 	while ((ifp = TAILQ_FIRST(ifs))) {
 		TAILQ_REMOVE(ifs, ifp, next);