Eliminate memcpy() for outgoing packets from tun device

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

diff --git a/tun.c b/tun.c
index ed61b72..0bbf18c 100644 (file)
--- a/tun.c
+++ b/tun.c
@@ -73,6 +73,9 @@
  */
 #if defined(__OpenBSD__) || defined(TUNSIFHEAD)
 #define TUN_HAS_AF_PREFIX 1
+#define AF_PREFIX_SIZE (sizeof(int))
+#else
+#define AF_PREFIX_SIZE (0)
 #endif
 
 #ifdef __sun__
@@ -570,16 +573,25 @@ int setup_tun(struct openconnect_info *vpninfo)
        return 0;
 }
 
+static struct pkt *out_pkt;
+
 int tun_mainloop(struct openconnect_info *vpninfo, int *timeout)
 {
-       unsigned char buf[2000];
-       int len;
        int work_done = 0;
        int moredata = 1;
 
        if (FD_ISSET(vpninfo->tun_fd, &vpninfo->select_rfds)) {
                while (moredata) {
-                       unsigned char *pkt = buf;
+                       int len = vpninfo->mtu;
+
+                       if (!out_pkt) {
+                               out_pkt = malloc(sizeof(struct pkt) + len);
+                               if (!out_pkt) {
+                                       vpn_progress(vpninfo, PRG_ERR, "Allocation failed\n");
+                                       break;
+                               }
+                       }
+
 #ifdef __sun__
                        /* On Solaris, if we're actually using tuntap and *not* just
                           passing packets through a UNIX socket to a child process,
@@ -590,8 +602,8 @@ int tun_mainloop(struct openconnect_info *vpninfo, int *timeout)
                                int flags = 0;
                                int ret;
                                
-                               strb.buf = buf;
-                               strb.maxlen = sizeof(buf);
+                               strb.buf = out_pkt->data;
+                               strb.maxlen = len;
                                strb.len = 0;
                                ret = getmsg(vpninfo->tun_fd, NULL, &strb, &flags);
                                if (ret < 0)
@@ -599,24 +611,19 @@ int tun_mainloop(struct openconnect_info *vpninfo, int *timeout)
 
                                if (!(ret & MOREDATA))
                                        moredata = 0;
-                               len = strb.len;
+                               out_pkt->len = strb.len;
                        } else
 #endif /* __sun__ ... */
                        {
-                               len = read(vpninfo->tun_fd, buf, sizeof(buf));
+                               len = read(vpninfo->tun_fd, out_pkt->data - AF_PREFIX_SIZE, len + AF_PREFIX_SIZE);
                                if (len <= 0)
                                        break;
-                       }
 
-#ifdef TUN_HAS_AF_PREFIX
-                       if (!vpninfo->script_tun) {
-                               pkt += 4;
-                               len -= 4;
+                               out_pkt->len = len - AF_PREFIX_SIZE;
                        }
-#endif
-                       if (queue_new_packet(&vpninfo->outgoing_queue, pkt,
-                                            len))
-                               break;
+
+                       queue_packet(&vpninfo->outgoing_queue, out_pkt);
+                       out_pkt = NULL;
 
                        work_done = 1;
                        vpninfo->outgoing_qlen++;