Drain the correct UDP socket.

diff --git a/dhcp.c b/dhcp.c
index ef00d97eae2587f259fc252d0c10e4e4da582d5f..99707d6cd38b7ac6958f1f617785b5eccf72678d 100644 (file)
--- a/dhcp.c
+++ b/dhcp.c
@@ -2590,15 +2590,21 @@ dhcp_handlepacket(void *arg)
 static void
 dhcp_handleudp(void *arg)
 {
+       int fd;
        const struct interface *ifp;
        const struct dhcp_state *state;
        uint8_t buffer[sizeof(struct dhcp_message)];
 
-       ifp = arg;
-       state = D_CSTATE(ifp);
+       if (arg) {
+               ifp = arg;
+               state = D_CSTATE(ifp);
+               fd = state->udp_fd;
+       } else
+               fd = udp_fd;
+
        /* Just read what's in the UDP fd and discard it as we always read
         * from the raw fd */
-       read(state->udp_fd, buffer, sizeof(buffer));
+       read(fd, buffer, sizeof(buffer));
 }
 
 static int
@@ -2708,11 +2714,6 @@ dhcp_init(struct interface *ifp)
        const struct if_options *ifo;
        size_t len;
 
-       /* Listen on *.*.*.*:bootpc so that the kernel never sends an
-        * ICMP port unreachable message back to the DHCP server */
-       if (udp_fd == -1 && dhcp_openudp(NULL) != -1)
-               eloop_event_add(udp_fd, dhcp_handleudp, NULL);
-
        state = D_STATE(ifp);
        if (state == NULL) {
                ifp->if_data[IF_DATA_DHCP] = calloc(1, sizeof(*state));
@@ -2795,6 +2796,11 @@ dhcp_start(struct interface *ifp)
        if (!(ifo->options & DHCPCD_IPV4))
                return;
 
+       /* Listen on *.*.*.*:bootpc so that the kernel never sends an
+        * ICMP port unreachable message back to the DHCP server */
+       if (udp_fd == -1 && dhcp_openudp(NULL) != -1)
+               eloop_event_add(udp_fd, dhcp_handleudp, NULL);
+
        if (dhcp_init(ifp) == -1) {
                syslog(LOG_ERR, "%s: dhcp_init: %m", ifp->name);
                return;