From: Roy Marples <roy@marples.name>
Date: Thu, 14 Oct 2021 05:31:11 +0000 (+0100)
Subject: DHCP: Set INFORM state only when we are about to inform
X-Git-Tag: v10.0.0~75
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=6e9535cc32f779dd527ec2c218a27aa0dec0724d;p=thirdparty%2Fdhcpcd.git

DHCP: Set INFORM state only when we are about to inform

As we may not find an address right away.
While here, tidy up and comment code about deriving the address
when none is specified for inform and static setups.
---

diff --git a/src/dhcp.c b/src/dhcp.c
index 5c38bbeb..bfd40127 100644
--- a/src/dhcp.c
+++ b/src/dhcp.c
@@ -2039,7 +2039,6 @@ dhcp_finish_dad(struct interface *ifp, struct in_addr *ia)
 		dhcp_inform(ifp);
 }
 
-
 static bool
 dhcp_addr_duplicated(struct interface *ifp, struct in_addr *ia)
 {
@@ -2573,7 +2572,6 @@ dhcp_inform(struct interface *ifp)
 	state = D_STATE(ifp);
 	ifo = ifp->options;
 
-	state->state = DHS_INFORM;
 	free(state->offer);
 	state->offer = NULL;
 	state->offer_len = 0;
@@ -2614,6 +2612,7 @@ dhcp_inform(struct interface *ifp)
 		}
 	}
 
+	state->state = DHS_INFORM;
 	state->addr = ia;
 	state->offer_len = dhcp_message_new(&state->offer,
 	    &ia->addr, &ia->mask);
@@ -4269,37 +4268,38 @@ dhcp_handleifa(int cmd, struct ipv4_addr *ia, pid_t pid)
 	}
 #endif
 
+	/* If we have requested a specific address, return now.
+	 * The below code is only for when inform or static has been
+	 * requested without a specific address. */
+	if (ifo->req_addr.s_addr != INADDR_ANY)
+		return ia;
+
+	/* Only inform if we are NOT in the inform state or bound. */
 	if (ifo->options & DHCPCD_INFORM) {
 		if (state->state != DHS_INFORM && state->state != DHS_BOUND)
 			dhcp_inform(ifp);
 		return ia;
 	}
 
+	/* Static and inform are mutually exclusive. If not static, return. */
 	if (!(ifo->options & DHCPCD_STATIC))
 		return ia;
-	if (ifo->req_addr.s_addr != INADDR_ANY)
-		return ia;
 
 	free(state->old);
 	state->old = state->new;
 	state->new_len = dhcp_message_new(&state->new, &ia->addr, &ia->mask);
 	if (state->new == NULL)
 		return ia;
+
 	if (ifp->flags & IFF_POINTOPOINT) {
 		for (i = 1; i < 255; i++)
 			if (i != DHO_ROUTER && has_option_mask(ifo->dstmask,i))
 				dhcp_message_add_addr(state->new, i, ia->brd);
 	}
+
 	state->reason = "STATIC";
 	rt_build(ifp->ctx, AF_INET);
 	script_runreason(ifp, state->reason);
-	if (ifo->options & DHCPCD_INFORM) {
-		state->state = DHS_INFORM;
-		dhcp_new_xid(ifp);
-		state->lease.server.s_addr = INADDR_ANY;
-		state->addr = ia;
-		dhcp_inform(ifp);
-	}
 
 	return ia;
 }