Configurable TCP_NODELAY option on network connections

[originally from svn r1428]

network.h

@@ -68,7 +68,7 @@ void sk_getaddr(SockAddr addr, char *buf, int buflen);
 void sk_addr_free(SockAddr addr);
 
 Socket sk_new(SockAddr addr, int port, int privport, int oobinline,
-	      Plug p);
+	      int nodelay, Plug p);
 
 Socket sk_newlistener(int port, Plug plug, int local_host_only);
 

plink.c

@@ -735,8 +735,11 @@ int main(int argc, char **argv)
     {
 	char *error;
 	char *realhost;
+	/* nodelay is only useful if stdin is a character device (console) */
+	int nodelay = cfg.tcp_nodelay &&
+	    (GetFileType(GetStdHandle(STD_INPUT_HANDLE)) == FILE_TYPE_CHAR);
 
-	error = back->init(cfg.host, cfg.port, &realhost);
+	error = back->init(cfg.host, cfg.port, &realhost, nodelay);
 	if (error) {
 	    fprintf(stderr, "Unable to open connection:\n%s", error);
 	    return 1;

portfwd.c

@@ -138,7 +138,7 @@ char *pfd_newconnect(Socket *s, char *hostname, int port, void *c)
     pr->ready = 1;
     pr->c = c;
 
-    pr->s = *s = sk_new(addr, port, 0, 1, (Plug) pr);
+    pr->s = *s = sk_new(addr, port, 0, 1, 0, (Plug) pr);
     if ((err = sk_socket_error(*s))) {
 	sfree(pr);
 	return err;

psftp.c

@@ -1820,7 +1820,7 @@ int main(int argc, char *argv[])
 
     back = &ssh_backend;
 
-    err = back->init(cfg.host, cfg.port, &realhost);
+    err = back->init(cfg.host, cfg.port, &realhost, 0);
     if (err != NULL) {
 	fprintf(stderr, "ssh_init: %s", err);
 	return 1;

putty.h

@@ -202,7 +202,7 @@ enum {
 };
 
 typedef struct {
-    char *(*init) (char *host, int port, char **realhost);
+    char *(*init) (char *host, int port, char **realhost, int nodelay);
     /* back->send() returns the current amount of buffered data. */
     int (*send) (char *buf, int len);
     /* back->sendbuffer() does the same thing but without attempting a send */
@@ -236,6 +236,7 @@ typedef struct {
     int close_on_exit;
     int warn_on_close;
     int ping_interval;		       /* in seconds */
+    int tcp_nodelay;
     /* SSH options */
     char remote_cmd[512];
     char remote_cmd2[512];	       /* fallback if the first fails

raw.c

@@ -57,7 +57,7 @@ static void raw_sent(Plug plug, int bufsize)
  * Also places the canonical host name into `realhost'. It must be
  * freed by the caller.
  */
-static char *raw_init(char *host, int port, char **realhost)
+static char *raw_init(char *host, int port, char **realhost, int nodelay)
 {
     static struct plug_function_table fn_table = {
 	raw_closing,
@@ -92,7 +92,7 @@ static char *raw_init(char *host, int port, char **realhost)
 	sprintf(buf, "Connecting to %.100s port %d", addrbuf, port);
 	logevent(buf);
     }
-    s = sk_new(addr, port, 0, 1, &fn_table_ptr);
+    s = sk_new(addr, port, 0, 1, nodelay, &fn_table_ptr);
     if ((err = sk_socket_error(s)))
 	return err;
 

rlogin.c

@@ -86,7 +86,7 @@ static void rlogin_sent(Plug plug, int bufsize)
  * Also places the canonical host name into `realhost'. It must be
  * freed by the caller.
  */
-static char *rlogin_init(char *host, int port, char **realhost)
+static char *rlogin_init(char *host, int port, char **realhost, int nodelay)
 {
     static struct plug_function_table fn_table = {
 	rlogin_closing,
@@ -121,7 +121,7 @@ static char *rlogin_init(char *host, int port, char **realhost)
 	sprintf(buf, "Connecting to %.100s port %d", addrbuf, port);
 	logevent(buf);
     }
-    s = sk_new(addr, port, 1, 0, &fn_table_ptr);
+    s = sk_new(addr, port, 1, 0, nodelay, &fn_table_ptr);
     if ((err = sk_socket_error(s)))
 	return err;
 

scp.c

@@ -689,7 +689,7 @@ static void do_cmd(char *host, char *user, char *cmd)
 
     back = &ssh_backend;
 
-    err = back->init(cfg.host, cfg.port, &realhost);
+    err = back->init(cfg.host, cfg.port, &realhost, 0);
     if (err != NULL)
 	bump("ssh_init: %s", err);
     ssh_scp_init();

settings.c

@@ -145,6 +145,7 @@ void save_settings(char *section, int do_host, Config * cfg)
     write_setting_i(sesskey, "WarnOnClose", !!cfg->warn_on_close);
     write_setting_i(sesskey, "PingInterval", cfg->ping_interval / 60);	/* minutes */
     write_setting_i(sesskey, "PingIntervalSecs", cfg->ping_interval % 60);	/* seconds */
+    write_setting_i(sesskey, "TCPNoDelay", cfg->tcp_nodelay);
     write_setting_s(sesskey, "TerminalType", cfg->termtype);
     write_setting_s(sesskey, "TerminalSpeed", cfg->termspeed);
     {
@@ -326,6 +327,7 @@ void load_settings(char *section, int do_host, Config * cfg)
 	gppi(sesskey, "PingIntervalSecs", 0, &pingsec);
 	cfg->ping_interval = pingmin * 60 + pingsec;
     }
+    gppi(sesskey, "TCPNoDelay", 1, &cfg->tcp_nodelay);
     gpps(sesskey, "TerminalType", "xterm", cfg->termtype,
 	 sizeof(cfg->termtype));
     gpps(sesskey, "TerminalSpeed", "38400,38400", cfg->termspeed,

ssh.c

@@ -1657,7 +1657,7 @@ static void ssh_sent(Plug plug, int bufsize)
  * Also places the canonical host name into `realhost'. It must be
  * freed by the caller.
  */
-static char *connect_to_host(char *host, int port, char **realhost)
+static char *connect_to_host(char *host, int port, char **realhost, int nodelay)
 {
     static struct plug_function_table fn_table = {
 	ssh_closing,
@@ -1714,7 +1714,7 @@ static char *connect_to_host(char *host, int port, char **realhost)
 	sprintf(buf, "Connecting to %.100s port %d", addrbuf, port);
 	logevent(buf);
     }
-    s = sk_new(addr, port, 0, 1, &fn_table_ptr);
+    s = sk_new(addr, port, 0, 1, nodelay, &fn_table_ptr);
     if ((err = sk_socket_error(s)))
 	return err;
 
@@ -5109,7 +5109,7 @@ static void ssh2_protocol(unsigned char *in, int inlen, int ispkt)
  *
  * Returns an error message, or NULL on success.
  */
-static char *ssh_init(char *host, int port, char **realhost)
+static char *ssh_init(char *host, int port, char **realhost, int nodelay)
 {
     char *p;
 
@@ -5125,7 +5125,7 @@ static char *ssh_init(char *host, int port, char **realhost)
     ssh_overall_bufsize = 0;
     ssh_fallback_cmd = 0;
 
-    p = connect_to_host(host, port, realhost);
+    p = connect_to_host(host, port, realhost, nodelay);
     if (p != NULL)
 	return p;
 

telnet.c

@@ -601,7 +601,7 @@ static void telnet_sent(Plug plug, int bufsize)
  * Also places the canonical host name into `realhost'. It must be
  * freed by the caller.
  */
-static char *telnet_init(char *host, int port, char **realhost)
+static char *telnet_init(char *host, int port, char **realhost, int nodelay)
 {
     static struct plug_function_table fn_table = {
 	telnet_closing,
@@ -636,7 +636,7 @@ static char *telnet_init(char *host, int port, char **realhost)
 	sprintf(buf, "Connecting to %.100s port %d", addrbuf, port);
 	logevent(buf);
     }
-    s = sk_new(addr, port, 0, 1, &fn_table_ptr);
+    s = sk_new(addr, port, 0, 1, nodelay, &fn_table_ptr);
     if ((err = sk_socket_error(s)))
 	return err;
 

windlg.c

@@ -405,12 +405,14 @@ enum { IDCX_ABOUT =
     IDC_TITLE_CONNECTION,
     IDC_BOX_CONNECTION1,
     IDC_BOX_CONNECTION2,
+    IDC_BOX_CONNECTION3,
     IDC_TTSTATIC,
     IDC_TTEDIT,
     IDC_LOGSTATIC,
     IDC_LOGEDIT,
     IDC_PINGSTATIC,
     IDC_PINGEDIT,
+    IDC_NODELAY,
     connectionpanelend,
 
     telnetpanelstart,
@@ -612,6 +614,7 @@ static void init_dlg_ctrls(HWND hwnd, int keepsess)
 		     cfg.protocol ==
 		     PROT_RLOGIN ? IDC_PROTRLOGIN : IDC_PROTRAW);
     SetDlgItemInt(hwnd, IDC_PINGEDIT, cfg.ping_interval, FALSE);
+    CheckDlgButton(hwnd, IDC_NODELAY, cfg.tcp_nodelay);
 
     CheckRadioButton(hwnd, IDC_DEL008, IDC_DEL127,
 		     cfg.bksp_is_delete ? IDC_DEL127 : IDC_DEL008);
@@ -1224,7 +1227,7 @@ static void create_controls(HWND hwnd, int dlgtype, int panel)
     }
 
     if (panel == connectionpanelstart) {
-	/* The Connection panel. Accelerators used: [acgo] tuk */
+	/* The Connection panel. Accelerators used: [acgo] tukn */
 	struct ctlpos cp;
 	ctlposinit(&cp, hwnd, 80, 3, 13);
 	bartitle(&cp, "Options controlling the connection",
@@ -1248,6 +1251,13 @@ static void create_controls(HWND hwnd, int dlgtype, int panel)
 	staticedit(&cp, "Seconds between &keepalives (0 to turn off)",
 		   IDC_PINGSTATIC, IDC_PINGEDIT, 20);
 	endbox(&cp);
+	if (dlgtype == 0) {
+	    beginbox(&cp, "Low-level TCP connection options",
+		     IDC_BOX_CONNECTION3);
+	    checkbox(&cp, "Disable &Nagle's algorithm (TCP_NODELAY option)",
+		     IDC_NODELAY);
+	    endbox(&cp);
+	}
     }
 
     if (panel == telnetpanelstart) {
@@ -1777,6 +1787,12 @@ static int GenericMainDlgProc(HWND hwnd, UINT msg,
 		    MyGetDlgItemInt(hwnd, IDC_PINGEDIT,
 				    &cfg.ping_interval);
 		break;
+	      case IDC_NODELAY:
+		if (HIWORD(wParam) == BN_CLICKED ||
+		    HIWORD(wParam) == BN_DOUBLECLICKED)
+			cfg.tcp_nodelay =
+			IsDlgButtonChecked(hwnd, IDC_NODELAY);
+		break;
 	      case IDC_DEL008:
 	      case IDC_DEL127:
 		if (HIWORD(wParam) == BN_CLICKED ||

window.c

@@ -508,7 +508,7 @@ int WINAPI WinMain(HINSTANCE inst, HINSTANCE prev, LPSTR cmdline, int show)
 	char msg[1024], *title;
 	char *realhost;
 
-	error = back->init(cfg.host, cfg.port, &realhost);
+	error = back->init(cfg.host, cfg.port, &realhost, cfg.tcp_nodelay);
 	if (error) {
 	    sprintf(msg, "Unable to open connection to\n"
 		    "%.800s\n" "%s", cfg.host, error);

winnet.c

@@ -439,7 +439,7 @@ Socket sk_register(void *sock, Plug plug)
 }
 
 Socket sk_new(SockAddr addr, int port, int privport, int oobinline,
-	      Plug plug)
+	      int nodelay, Plug plug)
 {
     static struct socket_function_table fn_table = {
 	sk_tcp_plug,
@@ -494,6 +494,11 @@ Socket sk_new(SockAddr addr, int port, int privport, int oobinline,
 	setsockopt(s, SOL_SOCKET, SO_OOBINLINE, (void *) &b, sizeof(b));
     }
 
+    if (nodelay) {
+	BOOL b = TRUE;
+	setsockopt(s, IPPROTO_TCP, TCP_NODELAY, (void *) &b, sizeof(b));
+    }
+
     /*
      * Bind to local address.
      */

x11fwd.c

@@ -195,7 +195,7 @@ char *x11_init(Socket * s, char *display, void *c)
     pr->throttled = pr->throttle_override = 0;
     pr->c = c;
 
-    pr->s = *s = sk_new(addr, port, 0, 1, (Plug) pr);
+    pr->s = *s = sk_new(addr, port, 0, 1, 0, (Plug) pr);
     if ((err = sk_socket_error(*s))) {
 	sfree(pr);
 	return err;