1 files changed, 78 insertions, 0 deletions
diff --git a/net/tap-linux.c b/net/tap-linux.c
new file mode 100644
index 0000000000..c6f751ee7c
--- /dev/null
+++ b/net/tap-linux.c
@@ -0,0 +1,78 @@
+/*
+ * QEMU System Emulator
+ *
+ * Copyright (c) 2003-2008 Fabrice Bellard
+ * Copyright (c) 2009 Red Hat, Inc.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include "net/tap.h"
+#include "net/tap-linux.h"
+
+#include <net/if.h>
+#include <sys/ioctl.h>
+
+#include "sysemu.h"
+#include "qemu-common.h"
+
+int tap_open(char *ifname, int ifname_size, int *vnet_hdr, int vnet_hdr_required)
+{
+    struct ifreq ifr;
+    int fd, ret;
+
+    TFR(fd = open("/dev/net/tun", O_RDWR));
+    if (fd < 0) {
+        fprintf(stderr, "warning: could not open /dev/net/tun: no virtual network emulation\n");
+        return -1;
+    }
+    memset(&ifr, 0, sizeof(ifr));
+    ifr.ifr_flags = IFF_TAP | IFF_NO_PI;
+
+    if (*vnet_hdr) {
+        unsigned int features;
+
+        if (ioctl(fd, TUNGETFEATURES, &features) == 0 &&
+            features & IFF_VNET_HDR) {
+            *vnet_hdr = 1;
+            ifr.ifr_flags |= IFF_VNET_HDR;
+        }
+
+        if (vnet_hdr_required && !*vnet_hdr) {
+            qemu_error("vnet_hdr=1 requested, but no kernel "
+                       "support for IFF_VNET_HDR available");
+            close(fd);
+            return -1;
+        }
+    }
+
+    if (ifname[0] != '\0')
+        pstrcpy(ifr.ifr_name, IFNAMSIZ, ifname);
+    else
+        pstrcpy(ifr.ifr_name, IFNAMSIZ, "tap%d");
+    ret = ioctl(fd, TUNSETIFF, (void *) &ifr);
+    if (ret != 0) {
+        fprintf(stderr, "warning: could not configure /dev/net/tun: no virtual network emulation\n");
+        close(fd);
+        return -1;
+    }
+    pstrcpy(ifname, ifname_size, ifr.ifr_name);
+    fcntl(fd, F_SETFL, O_NONBLOCK);
+    return fd;
+}