Send packet-stream goodbye

This helps some streams to close.

sbotc.c

@@ -53,6 +53,7 @@ struct boxs {
 	size_t rx_buf_pos;
 	size_t rx_buf_len;
 	bool noauth;
+	bool wrote_goodbye;
 };
 
 enum pkt_type {
@@ -330,6 +331,7 @@ static void shs_connect(int sfd, int infd, int outfd, const unsigned char pubkey
 	bs->rx_buf_len = 0;
 	bs->s = sfd;
 	bs->noauth = false;
+	bs->wrote_goodbye = false;
 }
 
 static int pubkey_decode(const char *key_str, unsigned char key[32]) {
@@ -630,6 +632,12 @@ static void ps_write(struct boxs *bs, const char *data, size_t len, enum pkt_typ
 	bs_write(bs, out_buf, out_len);
 }
 
+static void ps_goodbye(struct boxs *bs) {
+	if (bs->wrote_goodbye) return;
+	bs->wrote_goodbye = true;
+	bs_write(bs, zeros, 9);
+}
+
 static int ps_read_header(struct boxs *bs, size_t *len, int *req_id, enum pkt_flags *flags) {
 	char buf[9];
 	struct pkt_header header;
@@ -702,6 +710,7 @@ static enum stream_state muxrpc_read_source_1(struct boxs *bs, int outfd, int re
 	int rc = ps_read_header(bs, &len, &req, &flags);
 	if (rc < 0) err(1, "ps_read_header");
 	if (req == 0 && len == 0) {
+		if (bs->wrote_goodbye) return stream_state_ended_ok;
 		warnx("unexpected end of parent stream");
 		return stream_state_ended_error;
 	}
@@ -766,6 +775,7 @@ static enum stream_state muxrpc_write_sink_1(struct boxs *bs, int infd,
 	if (sz < 0) err(1, "read");
 	if (sz == 0) {
 		ps_write(bs, "true", 4, pkt_type_json, req_id, true, true);
+		ps_goodbye(bs);
 		return stream_state_ended_ok;
 	}
 	ps_write(bs, buf, sz, ptype, req_id, true, false);