4 files changed, 34 insertions, 2 deletions

diff --git a/arp.c b/arp.c
index 33b03cf..bb042e9 100644
--- a/arp.c
+++ b/arp.c
@@ -168,6 +168,9 @@ void arp_announce(const struct ctx *c, struct in_addr *ip,
 		struct arpmsg am;
 	} __attribute__((__packed__)) msg;
 
+	if (!tap_is_ready(c))
+		return;
+
 	/* Ethernet header */
 	msg.eh.h_proto = htons(ETH_P_ARP);
 	memcpy(msg.eh.h_dest, MAC_BROADCAST, sizeof(msg.eh.h_dest));
diff --git a/ndp.c b/ndp.c
index a33239d..eb9e313 100644
--- a/ndp.c
+++ b/ndp.c
@@ -227,7 +227,8 @@ static void ndp_na(const struct ctx *c, const struct in6_addr *dst,
  */
 void ndp_unsolicited_na(const struct ctx *c, const struct in6_addr *addr)
 {
-	ndp_na(c, &in6addr_ll_all_nodes, addr);
+	if (tap_is_ready(c))
+		ndp_na(c, &in6addr_ll_all_nodes, addr);
 }
 
 /**
@@ -411,7 +412,7 @@ void ndp_timer(const struct ctx *c, const struct timespec *now)
 	time_t max_rtr_adv_interval = DEFAULT_MAX_RTR_ADV_INTERVAL;
 	time_t min_rtr_adv_interval, interval;
 
-	if (c->fd_tap < 0 || c->no_ra || now->tv_sec < next_ra)
+	if (!tap_is_ready(c) || c->no_ra || now->tv_sec < next_ra)
 		return;
 
 	/* We must advertise before the route's lifetime expires */
diff --git a/tap.c b/tap.c
index bb139d6..44b0644 100644
--- a/tap.c
+++ b/tap.c
@@ -1340,6 +1340,30 @@ static void tap_sock_unix_init(const struct ctx *c)
 }
 
 /**
+ * tap_is_ready() - Check if tap interface is ready to send packets
+ * @c:		Execution context
+ *
+ * For pasta mode, checks if the tap interface is up.
+ * For other modes, just checks if fd_tap is valid.
+ *
+ * Return: true if ready, false otherwise
+ */
+bool tap_is_ready(const struct ctx *c)
+{
+	if (c->fd_tap < 0)
+		return false;
+
+	if (c->mode == MODE_PASTA) {
+		/* If pasta_conf_ns is set, the interface was configured and
+		 * brought up during initialization. If not, it's still down.
+		 */
+		return c->pasta_conf_ns;
+	}
+
+	return true;
+}
+
+/**
  * tap_start_connection() - start a new connection
  * @c:		Execution context
  */
@@ -1362,6 +1386,9 @@ static void tap_start_connection(const struct ctx *c)
 
 	epoll_add(c->epollfd, EPOLLIN | EPOLLRDHUP, ref);
 
+	if (!tap_is_ready(c))
+		return;
+
 	if (c->ifi4)
 		arp_send_init_req(c);
 	if (c->ifi6 && !c->no_ndp)
diff --git a/tap.h b/tap.h
index 1864173..ee22a9d 100644
--- a/tap.h
+++ b/tap.h
@@ -109,6 +109,7 @@ size_t tap_send_frames(const struct ctx *c, const struct iovec *iov,
 		       size_t bufs_per_frame, size_t nframes);
 void eth_update_mac(struct ethhdr *eh,
 		    const unsigned char *eth_d, const unsigned char *eth_s);
+bool tap_is_ready(const struct ctx *c);
 void tap_listen_handler(struct ctx *c, uint32_t events);
 void tap_handler_pasta(struct ctx *c, uint32_t events,
 		       const struct timespec *now);