From e8d338dde00a04e57189c5f02ee227875e9cf257 Mon Sep 17 00:00:00 2001
From: Catalin Patulea <cat@vv.carleton.ca>
Date: Mon, 2 Dec 2013 22:55:43 +0800
Subject: Set IPTOS_LOWDELAY on PTY sessions only

---
 cli-chansession.c |  1 +
 dbutil.c          | 29 +++++++++++++++++++++--------
 dbutil.h          |  2 ++
 includes.h        |  4 ++++
 svr-chansession.c |  2 ++
 5 files changed, 30 insertions(+), 8 deletions(-)

diff --git a/cli-chansession.c b/cli-chansession.c
index ed80453..6d610d4 100644
--- a/cli-chansession.c
+++ b/cli-chansession.c
@@ -369,6 +369,7 @@ static int cli_initchansess(struct Channel *channel) {
 
 	if (cli_opts.wantpty) {
 		send_chansess_pty_req(channel);
+		set_sock_priority(ses.sock_out);
 	}
 
 	send_chansess_shell_req(channel);
diff --git a/dbutil.c b/dbutil.c
index ce88731..4f15027 100644
--- a/dbutil.c
+++ b/dbutil.c
@@ -177,28 +177,41 @@ void dropbear_trace2(const char* format, ...) {
 }
 #endif /* DEBUG_TRACE */
 
-static void set_sock_priority(int sock) {
-
+void set_sock_nodelay(int sock) {
 	int val;
 
 	/* disable nagle */
 	val = 1;
 	setsockopt(sock, IPPROTO_TCP, TCP_NODELAY, (void*)&val, sizeof(val));
+}
+
+void set_sock_priority(int sock) {
+
+	int val, rc;
 
 	/* set the TOS bit for either ipv4 or ipv6 */
 #ifdef IPTOS_LOWDELAY
 	val = IPTOS_LOWDELAY;
 #if defined(IPPROTO_IPV6) && defined(IPV6_TCLASS)
-	setsockopt(sock, IPPROTO_IPV6, IPV6_TCLASS, (void*)&val, sizeof(val));
+	rc = setsockopt(sock, IPPROTO_IPV6, IPV6_TCLASS, (void*)&val, sizeof(val));
+	if (rc < 0)
+		dropbear_log(LOG_WARNING, "Couldn't set IPV6_TCLASS (%s)",
+				strerror(errno));
 #endif
-	setsockopt(sock, IPPROTO_IP, IP_TOS, (void*)&val, sizeof(val));
+	rc = setsockopt(sock, IPPROTO_IP, IP_TOS, (void*)&val, sizeof(val));
+	if (rc < 0)
+		dropbear_log(LOG_WARNING, "Couldn't set IP_TOS (%s)",
+				strerror(errno));
 #endif
 
 #ifdef SO_PRIORITY
 	/* linux specific, sets QoS class.
 	 * 6 looks to be optimal for interactive traffic (see tc-prio(8) ). */
-	val = 6;
-	setsockopt(sock, SOL_SOCKET, SO_PRIORITY, (void*) &val, sizeof(val));
+	val = TC_PRIO_INTERACTIVE;
+	rc = setsockopt(sock, SOL_SOCKET, SO_PRIORITY, (void*) &val, sizeof(val));
+	if (rc < 0)
+		dropbear_log(LOG_WARNING, "Couldn't set SO_PRIORITY (%s)",
+				strerror(errno));
 #endif
 
 }
@@ -290,7 +303,7 @@ int dropbear_listen(const char* address, const char* port,
 		}
 #endif
 
-		set_sock_priority(sock);
+		set_sock_nodelay(sock);
 
 		if (bind(sock, res->ai_addr, res->ai_addrlen) < 0) {
 			err = errno;
@@ -429,7 +442,7 @@ int connect_remote(const char* remotehost, const char* remoteport,
 		TRACE(("Error connecting: %s", strerror(err)))
 	} else {
 		/* Success */
-		set_sock_priority(sock);
+		set_sock_nodelay(sock);
 	}
 
 	freeaddrinfo(res0);
diff --git a/dbutil.h b/dbutil.h
index 7c7435c..7665845 100644
--- a/dbutil.h
+++ b/dbutil.h
@@ -66,6 +66,8 @@ void get_socket_address(int fd, char **local_host, char **local_port,
 		char **remote_host, char **remote_port, int host_lookup);
 void getaddrstring(struct sockaddr_storage* addr, 
 		char **ret_host, char **ret_port, int host_lookup);
+void set_sock_nodelay(int sock);
+void set_sock_priority(int sock);
 int dropbear_listen(const char* address, const char* port,
 		int *socks, unsigned int sockcount, char **errstring, int *maxfd);
 int spawn_command(void(*exec_fn)(void *user_data), void *exec_data,
diff --git a/includes.h b/includes.h
index 62a8d73..bae82f5 100644
--- a/includes.h
+++ b/includes.h
@@ -156,6 +156,10 @@ typedef unsigned int u_int32_t;
 typedef u_int32_t uint32_t;
 #endif /* HAVE_UINT32_T */
 
+#ifdef SO_PRIORITY
+#include <linux/pkt_sched.h>
+#endif
+
 #include "fake-rfc2553.h"
 
 #ifndef LOG_AUTHPRIV
diff --git a/svr-chansession.c b/svr-chansession.c
index b585a9a..b912eaf 100644
--- a/svr-chansession.c
+++ b/svr-chansession.c
@@ -580,6 +580,8 @@ static int sessionpty(struct ChanSess * chansess) {
 	/* Read the terminal modes */
 	get_termmodes(chansess);
 
+	set_sock_priority(ses.sock_out);
+
 	TRACE(("leave sessionpty"))
 	return DROPBEAR_SUCCESS;
 }
-- 
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