DHCP: Require unspecificed BOOTP port for master mode

This mirrors DHCP6 behaviour and will make privsep easier.
This is also a change in behaviour from prior versions and is the
first real change for dhcpcd-9.

diff --git a/src/dhcp.c b/src/dhcp.c
index 686aee449ba92e913c2c9aa0d76164ffc84c744b..dbaa257aeefc881db46ddf3b8d49e82ee8f81a34 100644 (file)
--- a/src/dhcp.c
+++ b/src/dhcp.c
@@ -1671,7 +1671,7 @@ dhcp_sendudp(struct interface *ifp, struct in_addr *to, void *data, size_t len)
 
        fd = state->udp_fd;
        if (fd == -1) {
-               fd = dhcp_openudp(state->addr != NULL ?&state->addr->addr:NULL);
+               fd = dhcp_openudp(&state->addr->addr);
                if (fd == -1)
                        return -1;
        }
@@ -2255,18 +2255,17 @@ dhcp_bind(struct interface *ifp)
                if (write_lease(ifp, state->new, state->new_len) == -1)
                        logerr(__func__);
 
-       ipv4_applyaddr(ifp);
-
        /* Close the BPF filter as we can now receive DHCP messages
         * on a UDP socket. */
-       if (!(state->udp_fd == -1 ||
-           (state->old != NULL && state->old->yiaddr != state->new->yiaddr)))
-               return;
-       dhcp_close(ifp);
+       if (ctx->options & DHCPCD_MASTER ||
+           state->old == NULL ||
+           state->old->yiaddr != state->new->yiaddr)
+               dhcp_close(ifp);
 
+       ipv4_applyaddr(ifp);
 
        /* If not in master mode, open an address specific socket. */
-       if (ctx->udp_fd != -1)
+       if (ctx->options & DHCPCD_MASTER)
                return;
        state->udp_fd = dhcp_openudp(&state->addr->addr);
        if (state->udp_fd == -1) {
@@ -3538,17 +3537,6 @@ dhcp_handleifudp(void *arg)
        dhcp_readudp(ifp->ctx, ifp);
 }
 
-static int
-dhcp_open(struct dhcpcd_ctx *ctx)
-{
-
-       if (ctx->udp_fd != -1 || (ctx->udp_fd = dhcp_openudp(NULL)) == -1)
-               return ctx->udp_fd;
-
-       eloop_event_add(ctx->eloop, ctx->udp_fd, dhcp_handleudp, ctx);
-       return ctx->udp_fd;
-}
-
 static int
 dhcp_openbpf(struct interface *ifp)
 {
@@ -3757,13 +3745,14 @@ dhcp_start1(void *arg)
         * ICMP port unreachable message back to the DHCP server.
         * Only do this in master mode so we don't swallow messages
         * for dhcpcd running on another interface. */
-       if (ctx->options & DHCPCD_MASTER) {
-               if (dhcp_open(ctx) == -1) {
-                       /* Don't log an error if some other process
-                        * is handling this. */
-                       if (errno != EADDRINUSE)
-                               logerr("%s: dhcp_open", __func__);
+       if (ctx->options & DHCPCD_MASTER && ctx->udp_fd == -1) {
+               ctx->udp_fd = dhcp_openudp(NULL);
+               if (ctx->udp_fd == -1) {
+                       logerr(__func__);
+                       return;
                }
+
+               eloop_event_add(ctx->eloop, ctx->udp_fd, dhcp_handleudp, ctx);
        }
 
        if (dhcp_init(ifp) == -1) {