From 1a110abef625d63961451d1d08bdec7a927168ff Mon Sep 17 00:00:00 2001
From: Sergey Alirzaev <zl29ah@gmail.com>
Date: Mon, 1 Oct 2018 04:10:39 +0300
Subject: [PATCH] client: add an option to set the inactivity timeout interval

---
 man/iodine.8 |  8 ++++++--
 src/client.c | 13 ++++++++++---
 src/client.h |  1 +
 src/iodine.c | 13 +++++++++++--
 4 files changed, 28 insertions(+), 7 deletions(-)

diff --git a/man/iodine.8 b/man/iodine.8
index 0eb9b9b..2942ac0 100644
--- a/man/iodine.8
+++ b/man/iodine.8
@@ -35,6 +35,8 @@ iodine, iodined \- tunnel IPv4 over DNS
 .I 0|1
 .B ] [-I
 .I interval
+.B ] [-o
+.I interval
 .B ]
 .B [
 .I nameserver
@@ -236,8 +238,10 @@ There are some DNS relays with very small timeouts,
 notably dnsadvantage.com (ultradns), that will give
 SERVFAIL errors even with \-I1; data will still get trough,
 and these errors can be ignored.
-Maximum useful value is 59, since iodined will close a client's
-connection after 60 seconds of inactivity.
+Maximum useful value is less than specified in \-o.
+.TP
+.B -o interval
+Inactivity timeout interval. Defaults to 60 seconds.
 .SS Server Options:
 .TP
 .B -c
diff --git a/src/client.c b/src/client.c
index 7f33654..1e51b8e 100644
--- a/src/client.c
+++ b/src/client.c
@@ -95,6 +95,7 @@ static unsigned short do_qtype = T_UNSET;
 static enum connection conn;
 
 static int selecttimeout;		/* RFC says timeout minimum 5sec */
+static int inactivitytimeout;
 static int lazymode;
 static long send_ping_soon;
 static time_t lastdownstreamtime;
@@ -211,6 +212,12 @@ client_set_selecttimeout(int select_timeout)
 	selecttimeout = select_timeout;
 }
 
+void
+client_set_inactivitytimeout(int inactivity_timeout)
+{
+	inactivitytimeout = inactivity_timeout;
+}
+
 void
 client_set_lazymode(int lazy_mode)
 {
@@ -847,7 +854,7 @@ tunnel_dns(int tun_fd, int dns_fd)
 	}
 
 	if (read == 5 && !strncmp("BADIP", buf, 5)) {
-		warnx("BADIP: Server rejected sender IP address (maybe iodined -c will help), or server kicked us due to timeout. Will exit if no downstream data is received in 60 seconds.");
+		warnx("BADIP: Server rejected sender IP address (maybe iodined -c will help), or server kicked us due to timeout. Will exit if no downstream data is received in %d seconds.", inactivitytimeout);
 		return -1;	/* nothing done */
 	}
 
@@ -1117,8 +1124,8 @@ client_tunnel(int tun_fd, int dns_fd)
 
 		i = select(MAX(tun_fd, dns_fd) + 1, &fds, NULL, NULL, &tv);
 
- 		if (lastdownstreamtime + 60 < time(NULL)) {
- 			warnx("No downstream data received in 60 seconds, shutting down.");
+ 		if (lastdownstreamtime + inactivitytimeout < time(NULL)) {
+ 			warnx("No downstream data received in %d seconds, shutting down.", inactivitytimeout);
  			running = 0;
  		}
 
diff --git a/src/client.h b/src/client.h
index 3dab6fb..6025620 100644
--- a/src/client.h
+++ b/src/client.h
@@ -31,6 +31,7 @@ int client_set_qtype(char *qtype);
 char *client_get_qtype(void);
 void client_set_downenc(char *encoding);
 void client_set_selecttimeout(int select_timeout);
+void client_set_inactivitytimeout(int inactivity_timeout);
 void client_set_lazymode(int lazy_mode);
 void client_set_hostname_maxlen(int i);
 
diff --git a/src/iodine.c b/src/iodine.c
index 64ed950..5d1a066 100644
--- a/src/iodine.c
+++ b/src/iodine.c
@@ -98,7 +98,8 @@ static void help(FILE *stream, bool verbose)
 			"  -t dir to chroot to directory dir\n"
 			"  -d device to set tunnel device name\n"
 			"  -z context, to apply specified SELinux context after initialization\n"
-			"  -F pidfile to write pid to a file\n\n"
+			"  -F pidfile to write pid to a file\n"
+			"  -o inactivity timeout interval\n\n"
 			"nameserver is the IP number/hostname of the relaying nameserver. If absent,\n"
 			"           /etc/resolv.conf is used\n"
 			"topdomain is the FQDN that is delegated to the tunnel endpoint.\n");
@@ -143,6 +144,7 @@ int main(int argc, char **argv)
 	int raw_mode;
 	int lazymode;
 	int selecttimeout;
+	int inactivitytimeout;
 	int hostname_maxlen;
 #ifdef OPENBSD
 	int rtable = 0;
@@ -172,6 +174,7 @@ int main(int argc, char **argv)
 	raw_mode = 1;
 	lazymode = 1;
 	selecttimeout = 4;
+	inactivitytimeout = 60;
 	hostname_maxlen = 0xFF;
 	nameserv_family = AF_UNSPEC;
 
@@ -190,7 +193,7 @@ int main(int argc, char **argv)
 		__progname++;
 #endif
 
-	while ((choice = getopt(argc, argv, "46vfhru:t:d:R:P:m:M:F:T:O:L:I:")) != -1) {
+	while ((choice = getopt(argc, argv, "46vfhru:t:d:R:P:m:M:F:T:O:L:I:o:")) != -1) {
 		switch(choice) {
 		case '4':
 			nameserv_family = AF_INET;
@@ -271,6 +274,11 @@ int main(int argc, char **argv)
 			if (selecttimeout < 1)
 				selecttimeout = 1;
 			break;
+		case 'o':
+			inactivitytimeout = atoi(optarg);
+			if (inactivitytimeout < 1)
+				inactivitytimeout = 1;
+			break;
 		default:
 			usage();
 			/* NOTREACHED */
@@ -322,6 +330,7 @@ int main(int argc, char **argv)
 	}
 
 	client_set_selecttimeout(selecttimeout);
+	client_set_inactivitytimeout(inactivitytimeout);
 	client_set_lazymode(lazymode);
 	client_set_topdomain(topdomain);
 	client_set_hostname_maxlen(hostname_maxlen);