Make CSTP connection in a single SSL record

By creating a buffer with the request and sending it in a single SSL record,
I roughly halve the amount of time it takes for the round trip from 215ms
to 116ms.

Introduce a buf_append() function to help with processing the buffer, since
I shouldn't just be using sprintf() like other places do. Will fix those
next...

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

diff --git a/cstp.c b/cstp.c
index 9435aa1..dbc24b9 100644 (file)
--- a/cstp.c
+++ b/cstp.c
@@ -66,6 +66,25 @@ static struct pkt dpd_resp_pkt = {
        .hdr = { 'S', 'T', 'F', 1, 0, 0, AC_PKT_DPD_RESP, 0 },
 };
 
+static int  __attribute__ ((format (printf, 3, 4)))
+    buf_append(char *buf, int len, const char *fmt, ...)
+{
+       int start = strlen(buf);
+       int ret;
+       va_list args;
+
+       if (start >= len)
+               return 0;
+
+       va_start(args, fmt);
+       ret = vsnprintf(buf + start, len - start, fmt, args);
+       va_end(args);
+
+       if (ret > len)
+               ret = len;
+
+       return ret;
+}
 
 static int start_cstp_connection(struct openconnect_info *vpninfo)
 {
@@ -113,23 +132,26 @@ static int start_cstp_connection(struct openconnect_info *vpninfo)
        }
 
  retry:
-       openconnect_SSL_printf(vpninfo, "CONNECT /CSCOSSLC/tunnel HTTP/1.1\r\n");
-       openconnect_SSL_printf(vpninfo, "Host: %s\r\n", vpninfo->hostname);
-       openconnect_SSL_printf(vpninfo, "User-Agent: %s\r\n", vpninfo->useragent);
-       openconnect_SSL_printf(vpninfo, "Cookie: webvpn=%s\r\n", vpninfo->cookie);
-       openconnect_SSL_printf(vpninfo, "X-CSTP-Version: 1\r\n");
-       openconnect_SSL_printf(vpninfo, "X-CSTP-Hostname: %s\r\n", vpninfo->localname);
-       if (vpninfo->deflate)
-               openconnect_SSL_printf(vpninfo, "X-CSTP-Accept-Encoding: deflate;q=1.0\r\n");
-       openconnect_SSL_printf(vpninfo, "X-CSTP-MTU: %d\r\n", vpninfo->mtu);
-       openconnect_SSL_printf(vpninfo, "X-CSTP-Address-Type: %s\r\n",
+       buf[0] = 0;
+       buf_append(buf, sizeof(buf), "CONNECT /CSCOSSLC/tunnel HTTP/1.1\r\n");
+       buf_append(buf, sizeof(buf), "Host: %s\r\n", vpninfo->hostname);
+       buf_append(buf, sizeof(buf), "User-Agent: %s\r\n", vpninfo->useragent);
+       buf_append(buf, sizeof(buf), "Cookie: webvpn=%s\r\n", vpninfo->cookie);
+       buf_append(buf, sizeof(buf), "X-CSTP-Version: 1\r\n");
+       buf_append(buf, sizeof(buf), "X-CSTP-Hostname: %s\r\n", vpninfo->localname);
+       if (vpninfo->deflate && i < sizeof(buf))
+               buf_append(buf, sizeof(buf), "X-CSTP-Accept-Encoding: deflate;q=1.0\r\n");
+       buf_append(buf, sizeof(buf), "X-CSTP-MTU: %d\r\n", vpninfo->mtu);
+       buf_append(buf, sizeof(buf), "X-CSTP-Address-Type: %s\r\n",
                               vpninfo->disable_ipv6?"IPv4":"IPv6,IPv4");
-       openconnect_SSL_printf(vpninfo, "X-DTLS-Master-Secret: ");
+       buf_append(buf, sizeof(buf), "X-DTLS-Master-Secret: ");
        for (i = 0; i < sizeof(vpninfo->dtls_secret); i++)
-               openconnect_SSL_printf(vpninfo, "%02X", vpninfo->dtls_secret[i]);
-       openconnect_SSL_printf(vpninfo, "\r\nX-DTLS-CipherSuite: %s\r\n\r\n",
+               buf_append(buf, sizeof(buf), "%02X", vpninfo->dtls_secret[i]);
+       buf_append(buf, sizeof(buf), "\r\nX-DTLS-CipherSuite: %s\r\n\r\n",
                               vpninfo->dtls_ciphers?:"AES256-SHA:AES128-SHA:DES-CBC3-SHA:DES-CBC-SHA");
 
+       openconnect_SSL_write(vpninfo, buf, strlen(buf));
+
        if ((i = openconnect_SSL_gets(vpninfo, buf, 65536) < 0)) {
                if (i == -EINTR)
                        return i;

diff --git a/libopenconnect.map.in b/libopenconnect.map.in
index c00ddb1..974d910 100644 (file)
--- a/libopenconnect.map.in
+++ b/libopenconnect.map.in
@@ -50,6 +50,7 @@ OPENCONNECT_PRIVATE {
        openconnect_close_https;
        openconnect_open_https;
        openconnect_SSL_printf;
+       openconnect_SSL_write;
        openconnect_version_str;
        openconnect_create_useragent;
        openconnect_report_ssl_errors;