From: Hans Dedecker <dedeckeh@gmail.com>
Date: Mon, 9 Jul 2018 06:58:00 +0000 (+0200)
Subject: dhcpv4: improve error checking in handle_dhcpv4()
X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=345bba0889ae9deeac4ca805ebc3f0661b4b3988;p=project%2Fodhcpd.git

dhcpv4: improve error checking in handle_dhcpv4()

Check ioctl return value as reported by Coverity in CID1437659

Signed-off-by: Hans Dedecker <dedeckeh@gmail.com>
---

diff --git a/src/dhcpv4.c b/src/dhcpv4.c
index dc10ba3..3386abb 100644
--- a/src/dhcpv4.c
+++ b/src/dhcpv4.c
@@ -928,19 +928,21 @@ static void handle_dhcpv4(void *addr, void *data, size_t len,
 		dest.sin_addr.s_addr = INADDR_BROADCAST;
 		dest.sin_port = htons(DHCPV4_CLIENT_PORT);
 	} else {
+		struct arpreq arp = {.arp_flags = ATF_COM};
+
 		/*
 		 * send reply to the newly (in this proccess) allocated IP
 		 */
 		dest.sin_addr = reply.yiaddr;
 		dest.sin_port = htons(DHCPV4_CLIENT_PORT);
 
-		struct arpreq arp = {.arp_flags = ATF_COM};
 		memcpy(arp.arp_ha.sa_data, req->chaddr, 6);
 		memcpy(&arp.arp_pa, &dest, sizeof(arp.arp_pa));
 		memcpy(arp.arp_dev, iface->ifname, sizeof(arp.arp_dev));
-		ioctl(sock, SIOCSARP, &arp);
-	}
 
+		if (ioctl(sock, SIOCSARP, &arp) < 0)
+			syslog(LOG_ERR, "ioctl(SIOCSARP): %m");
+	}
 
 	if (sendto(sock, &reply, sizeof(reply), MSG_DONTWAIT,
 			(struct sockaddr*)&dest, sizeof(dest)) < 0)