From: Roy Marples <roy@marples.name>
Date: Mon, 23 Nov 2020 13:22:20 +0000 (+0000)
Subject: DHCP: Only listen to the address if we successfully added it
X-Git-Tag: v9.3.4~6
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=7c1f6fe6343e3d3be8eb29ce7400f81f4b15df38;p=thirdparty%2Fdhcpcd.git

DHCP: Only listen to the address if we successfully added it

Fixes an issue on Linux where the headers advertise something
newer than what the kernel actually provides.
---

diff --git a/src/dhcp.c b/src/dhcp.c
index e2e9accd..fdfd8b3d 100644
--- a/src/dhcp.c
+++ b/src/dhcp.c
@@ -2364,13 +2364,14 @@ dhcp_bind(struct interface *ifp)
 		return;
 	}
 
+	/* Add the address */
+	if (ipv4_applyaddr(ifp) == NULL)
+		return;
+
 	/* Close the BPF filter as we can now receive DHCP messages
 	 * on a UDP socket. */
 	dhcp_closebpf(ifp);
 
-	/* Add the address */
-	ipv4_applyaddr(ifp);
-
 openudp:
 	/* If not in master mode, open an address specific socket. */
 	if (ctx->options & DHCPCD_MASTER ||
diff --git a/src/ipv4.c b/src/ipv4.c
index 92ecdbd0..220b3330 100644
--- a/src/ipv4.c
+++ b/src/ipv4.c
@@ -728,7 +728,7 @@ ipv4_daddaddr(struct interface *ifp, const struct dhcp_lease *lease)
 	return 0;
 }
 
-void
+struct ipv4_addr *
 ipv4_applyaddr(void *arg)
 {
 	struct interface *ifp = arg;
@@ -738,7 +738,7 @@ ipv4_applyaddr(void *arg)
 	struct ipv4_addr *ia;
 
 	if (state == NULL)
-		return;
+		return NULL;
 
 	lease = &state->lease;
 	if (state->new == NULL) {
@@ -757,7 +757,7 @@ ipv4_applyaddr(void *arg)
 			script_runreason(ifp, state->reason);
 		} else
 			rt_build(ifp->ctx, AF_INET);
-		return;
+		return NULL;
 	}
 
 	ia = ipv4_iffindaddr(ifp, &lease->addr, NULL);
@@ -783,22 +783,22 @@ ipv4_applyaddr(void *arg)
 #endif
 #ifndef IP_LIFETIME
 		if (ipv4_daddaddr(ifp, lease) == -1 && errno != EEXIST)
-			return;
+			return NULL;
 #endif
 	}
 #ifdef IP_LIFETIME
 	if (ipv4_daddaddr(ifp, lease) == -1 && errno != EEXIST)
-		return;
+		return NULL;
 #endif
 
 	ia = ipv4_iffindaddr(ifp, &lease->addr, NULL);
 	if (ia == NULL) {
 		logerrx("%s: added address vanished", ifp->name);
-		return;
+		return NULL;
 	}
 #if defined(ARP) && defined(IN_IFF_NOTUSEABLE)
 	if (ia->addr_flags & IN_IFF_NOTUSEABLE)
-		return;
+		return NULL;
 #endif
 
 	/* Delete the old address if different */
@@ -820,6 +820,7 @@ ipv4_applyaddr(void *arg)
 		script_runreason(ifp, state->reason);
 		dhcpcd_daemonise(ifp->ctx);
 	}
+	return ia;
 }
 
 void
diff --git a/src/ipv4.h b/src/ipv4.h
index bb3d5b2c..c72418e3 100644
--- a/src/ipv4.h
+++ b/src/ipv4.h
@@ -135,7 +135,7 @@ int ipv4_deladdr(struct ipv4_addr *, int);
 struct ipv4_addr *ipv4_addaddr(struct interface *,
     const struct in_addr *, const struct in_addr *, const struct in_addr *,
     uint32_t, uint32_t);
-void ipv4_applyaddr(void *);
+struct ipv4_addr *ipv4_applyaddr(void *);
 
 struct ipv4_addr *ipv4_iffindaddr(struct interface *,
     const struct in_addr *, const struct in_addr *);