From: Roy Marples <roy@marples.name>
Date: Tue, 25 Nov 2014 20:40:00 +0000 (+0000)
Subject: Zero length UDP packets are not an error condition on the socket.
X-Git-Tag: v6.6.3~8
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=fddd88aed45b2b9573f14c46ebcdd01514417d23;p=thirdparty%2Fdhcpcd.git

Zero length UDP packets are not an error condition on the socket.
Thanks to Michał Kępień.
---

diff --git a/arp.c b/arp.c
index 86274a6d..3a1de858 100644
--- a/arp.c
+++ b/arp.c
@@ -124,7 +124,7 @@ arp_packet(void *arg)
 	while (!(flags & RAW_EOF)) {
 		bytes = if_readrawpacket(ifp, ETHERTYPE_ARP,
 		    arp_buffer, sizeof(arp_buffer), &flags);
-		if (bytes == 0 || bytes == -1) {
+		if (bytes == -1) {
 			syslog(LOG_ERR, "%s: arp if_readrawpacket: %m",
 			    ifp->name);
 			dhcp_close(ifp);
diff --git a/dhcp.c b/dhcp.c
index 43e4046c..a98c5b95 100644
--- a/dhcp.c
+++ b/dhcp.c
@@ -2782,7 +2782,7 @@ dhcp_handlepacket(void *arg)
 	while (!(flags & RAW_EOF)) {
 		bytes = (size_t)if_readrawpacket(ifp, ETHERTYPE_IP,
 		    ifp->ctx->packet, udp_dhcp_len, &flags);
-		if (bytes == 0 || (ssize_t)bytes == -1) {
+		if ((ssize_t)bytes == -1) {
 			syslog(LOG_ERR, "%s: dhcp if_readrawpacket: %m",
 			    ifp->name);
 			dhcp_close(ifp);
diff --git a/dhcp6.c b/dhcp6.c
index 72d765e7..f4b77179 100644
--- a/dhcp6.c
+++ b/dhcp6.c
@@ -2551,7 +2551,7 @@ dhcp6_handledata(void *arg)
 	ctx = dhcpcd_ctx->ipv6;
 	ctx->rcvhdr.msg_controllen = CMSG_SPACE(sizeof(struct in6_pktinfo));
 	bytes = recvmsg(ctx->dhcp_fd, &ctx->rcvhdr, 0);
-	if (bytes == -1 || bytes == 0) {
+	if (bytes == -1) {
 		syslog(LOG_ERR, "recvmsg: %m");
 		close(ctx->dhcp_fd);
 		eloop_event_delete(dhcpcd_ctx->eloop, ctx->dhcp_fd, 0);
diff --git a/ipv6nd.c b/ipv6nd.c
index 574e69a2..56a7a4b3 100644
--- a/ipv6nd.c
+++ b/ipv6nd.c
@@ -1500,7 +1500,7 @@ ipv6nd_handledata(void *arg)
 	ctx->rcvhdr.msg_controllen = CMSG_SPACE(sizeof(struct in6_pktinfo)) +
 	    CMSG_SPACE(sizeof(int));
 	len = recvmsg(ctx->nd_fd, &ctx->rcvhdr, 0);
-	if (len == -1 || len == 0) {
+	if (len == -1) {
 		syslog(LOG_ERR, "recvmsg: %m");
 		eloop_event_delete(dhcpcd_ctx->eloop, ctx->nd_fd, 0);
 		close(ctx->nd_fd);