lnsocket: add pong responder function

Changelog-Added: Add lnsocket_pong method to respond to ping recv's
Signed-off-by: William Casarin <[email protected]>

lnrpc.c

@@ -34,7 +34,7 @@ int main(int argc, const char *argv[])
 	//int verbose = 1;
 
 	timeout_str = getenv("LNRPC_TIMEOUT");
-	int timeout_ms = timeout_str ? atoi(timeout_str) : 5000;
+	int timeout_ms = timeout_str ? atoi(timeout_str) : 50000000;
 
 	timeout.tv_sec = timeout_ms / 1000;
 	timeout.tv_usec = (timeout_ms % 1000) * 1000;
@@ -101,6 +101,10 @@ int main(int argc, const char *argv[])
 		case COMMANDO_REPLY_CONTINUES:
 			printf("%.*s", len - 8, buf + 8);
 			continue;
+		case WIRE_PING:
+			if (!lnsocket_pong(ln, buf, len)) {
+				fprintf(stderr, "pong error...\n");
+			}
 		default:
 			// ignore extra interleaved messages which can happen
 			continue;

lnsocket.c

@@ -374,6 +374,63 @@ int lnsocket_make_network_tlv(unsigned char *buf, int buflen,
 	return 1;
 }
 
+int lnsocket_make_pong_msg(unsigned char *buf, int buflen, u16 num_pong_bytes)
+{
+	struct cursor msg;
+
+	make_cursor(buf, buf + buflen, &msg);
+
+	if (!cursor_push_u16(&msg, WIRE_PONG))
+		return 0;
+
+	// don't include itself
+	num_pong_bytes = num_pong_bytes <= 4 ? 0 : num_pong_bytes - 4;
+
+	if (!cursor_push_u16(&msg, num_pong_bytes))
+		return 0;
+
+	if (msg.p + num_pong_bytes > msg.end)
+		return 0;
+
+	memset(msg.p, 0, num_pong_bytes);
+	msg.p += num_pong_bytes;
+
+	return msg.p - msg.start;
+}
+
+static int lnsocket_decode_ping_payload(const unsigned char *payload, int payload_len, u16 *pong_bytes)
+{
+	struct cursor msg;
+
+	make_cursor((u8*)payload, (u8*)payload + payload_len, &msg);
+
+	if (!cursor_pull_u16(&msg, pong_bytes))
+		return 0;
+
+	return 1;
+}
+
+int lnsocket_make_pong_from_ping(unsigned char *buf, int buflen, const unsigned char *ping, u16 ping_len)
+{
+	u16 pong_bytes;
+
+	if (!lnsocket_decode_ping_payload(ping, ping_len, &pong_bytes))
+		return 0;
+
+	return lnsocket_make_pong_msg(buf, buflen, pong_bytes);
+}
+
+int lnsocket_pong(struct lnsocket *ln, const unsigned char *ping, u16 ping_len)
+{
+	unsigned char pong[0xFFFF];
+	u16 len;
+
+	if (!(len = lnsocket_make_pong_from_ping(pong, sizeof(pong), ping, ping_len)))
+		return 0;
+
+	return lnsocket_write(ln, pong, len);
+}
+
 int lnsocket_make_ping_msg(unsigned char *buf, int buflen, u16 num_pong_bytes, u16 ignored_bytes)
 {
 	struct cursor msg;

lnsocket.h

@@ -70,7 +70,6 @@ struct lnsocket EXPORT *lnsocket_create();
 /* messages */
 
 int lnsocket_make_network_tlv(unsigned char *buf, int buflen, const unsigned char **blockids, int num_blockids, struct tlv *tlv_out);
-int EXPORT lnsocket_make_ping_msg(unsigned char *buf, int buflen, unsigned short num_pong_bytes, unsigned short ignored_bytes);
 int lnsocket_make_init_msg(unsigned char *buf, int buflen, const unsigned char *globalfeatures, unsigned short gflen, const unsigned char *features, unsigned short flen, const struct tlv **tlvs, unsigned short num_tlvs, unsigned short *outlen);
 
 int lnsocket_perform_init(struct lnsocket *ln);
@@ -84,7 +83,12 @@ int lnsocket_read(struct lnsocket *, unsigned char **buf, unsigned short *len);
 
 int lnsocket_send(struct lnsocket *, unsigned short msg_type, const unsigned char *payload, unsigned short payload_len);
 int lnsocket_recv(struct lnsocket *, unsigned short *msg_type, unsigned char **payload, unsigned short *payload_len);
+int lnsocket_pong(struct lnsocket *, const unsigned char *ping, unsigned short ping_len);
+
 
+int EXPORT lnsocket_make_pong_from_ping(unsigned char *buf, int buflen, const unsigned char *ping, unsigned short ping_len);
+int EXPORT lnsocket_make_ping_msg(unsigned char *buf, int buflen, unsigned short num_pong_bytes, unsigned short ignored_bytes);
+int EXPORT lnsocket_make_pong_msg(unsigned char *buf, int buflen, unsigned short num_pong_bytes);
 void* EXPORT lnsocket_secp(struct lnsocket *);
 void EXPORT lnsocket_genkey(struct lnsocket *);
 int EXPORT lnsocket_setkey(struct lnsocket *, const unsigned char key[32]);

test.c

@@ -20,6 +20,7 @@ int main(int argc, const char *argv[])
 {
 	static u8 msgbuf[4096];
 	u8 *buf;
+	u16 msgtype;
 	struct lnsocket *ln;
 
 	static unsigned char key[32] = {0};
@@ -58,11 +59,17 @@ int main(int argc, const char *argv[])
 	printf("sent ping ");
 	print_data(msgbuf, len);
 
-	if (!(ok = lnsocket_read(ln, &buf, &len)))
-		goto done;
+	for (int packets = 0; packets < 3; packets++) {
+		if (!(ok = lnsocket_recv(ln, &msgtype, &buf, &len)))
+			goto done;
+
+		if (msgtype == WIRE_PONG) {
+			printf("got pong! ");
+			print_data(buf, len);
+			break;
+		}
+	}
 
-	printf("got ");
-	print_data(buf, len);
 done:
 	lnsocket_print_errors(ln);
 	lnsocket_destroy(ln);