After DPD, keep retrying to connect for longer.

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

cstp.c

@@ -291,8 +291,10 @@ static int start_cstp_connection(struct openconnect_info *vpninfo)
 
 int make_cstp_connection(struct openconnect_info *vpninfo)
 {
-	if (!vpninfo->https_ssl && openconnect_open_https(vpninfo))
-		exit(1);
+	int ret;
+
+	if (!vpninfo->https_ssl && (ret=openconnect_open_https(vpninfo)))
+		return ret;
 
 	if (vpninfo->deflate) {
 		vpninfo->deflate_adler32 = 1;
@@ -317,13 +319,24 @@ int make_cstp_connection(struct openconnect_info *vpninfo)
 		}
 	}
 
-	if (start_cstp_connection(vpninfo))
-		return -EINVAL;
+	return start_cstp_connection(vpninfo);
+}
+
+static int cstp_reconnect(struct openconnect_info *vpninfo)
+{
+	int retries, nr_retries, ret;
+
+	nr_retries = vpninfo->reconnect_timeout / vpninfo->reconnect_interval;
 
+	while ((ret = make_cstp_connection(vpninfo))) {
+		retries++;
+		if (retries >= nr_retries)
+			return ret;
+		sleep(vpninfo->reconnect_interval);
+	}
 	return 0;
 }
 
-
 static int inflate_and_queue_packet(struct openconnect_info *vpninfo, int type, void *buf, int len)
 {
 	struct pkt *new = malloc(sizeof(struct pkt) + vpninfo->mtu);
@@ -528,7 +541,7 @@ int cstp_mainloop(struct openconnect_info *vpninfo, int *timeout)
 		if (vpninfo->current_ssl_pkt == vpninfo->deflate_pkt)
 			vpninfo->current_ssl_pkt = NULL;
 
-		if (make_cstp_connection(vpninfo)) {
+		if (cstp_reconnect(vpninfo)) {
 			vpninfo->progress(vpninfo, PRG_ERR, "Reconnect failed\n");
 			vpninfo->quit_reason = "SSL DPD detected dead peer; reconnect failed";
 			return 1;

main.c

@@ -155,6 +155,8 @@ int main(int argc, char **argv)
 	vpninfo->deflate = 1;
 	vpninfo->dtls_attempt_period = 60;
 	vpninfo->max_qlen = 10;
+	vpninfo->reconnect_interval = 20;
+	vpninfo->reconnect_timeout = 300;
 
 	if (RAND_bytes(vpninfo->dtls_secret, sizeof(vpninfo->dtls_secret)) != 1) {
 		fprintf(stderr, "Failed to initialise DTLS secret\n");

openconnect.h

@@ -106,6 +106,8 @@ struct openconnect_info {
 	z_stream deflate_strm;
 	uint32_t deflate_adler32;
 
+	int reconnect_timeout;
+	int reconnect_interval;
 	int dtls_attempt_period;
 	time_t new_dtls_started;
 	SSL_CTX *dtls_ctx;