]> git.proxmox.com Git - qemu.git/blame - net/tap-linux.c
net: move linux code into net/tap-linux.c
[qemu.git] / net / tap-linux.c
CommitLineData
c28b1c10
MM
1/*
2 * QEMU System Emulator
3 *
4 * Copyright (c) 2003-2008 Fabrice Bellard
5 * Copyright (c) 2009 Red Hat, Inc.
6 *
7 * Permission is hereby granted, free of charge, to any person obtaining a copy
8 * of this software and associated documentation files (the "Software"), to deal
9 * in the Software without restriction, including without limitation the rights
10 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
11 * copies of the Software, and to permit persons to whom the Software is
12 * furnished to do so, subject to the following conditions:
13 *
14 * The above copyright notice and this permission notice shall be included in
15 * all copies or substantial portions of the Software.
16 *
17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
18 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
20 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
21 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
22 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
23 * THE SOFTWARE.
24 */
25
26#include "net/tap.h"
27#include "net/tap-linux.h"
28
29#include <net/if.h>
30#include <sys/ioctl.h>
31
32#include "sysemu.h"
33#include "qemu-common.h"
34
35int tap_open(char *ifname, int ifname_size, int *vnet_hdr, int vnet_hdr_required)
36{
37 struct ifreq ifr;
38 int fd, ret;
39
40 TFR(fd = open("/dev/net/tun", O_RDWR));
41 if (fd < 0) {
42 fprintf(stderr, "warning: could not open /dev/net/tun: no virtual network emulation\n");
43 return -1;
44 }
45 memset(&ifr, 0, sizeof(ifr));
46 ifr.ifr_flags = IFF_TAP | IFF_NO_PI;
47
48 if (*vnet_hdr) {
49 unsigned int features;
50
51 if (ioctl(fd, TUNGETFEATURES, &features) == 0 &&
52 features & IFF_VNET_HDR) {
53 *vnet_hdr = 1;
54 ifr.ifr_flags |= IFF_VNET_HDR;
55 }
56
57 if (vnet_hdr_required && !*vnet_hdr) {
58 qemu_error("vnet_hdr=1 requested, but no kernel "
59 "support for IFF_VNET_HDR available");
60 close(fd);
61 return -1;
62 }
63 }
64
65 if (ifname[0] != '\0')
66 pstrcpy(ifr.ifr_name, IFNAMSIZ, ifname);
67 else
68 pstrcpy(ifr.ifr_name, IFNAMSIZ, "tap%d");
69 ret = ioctl(fd, TUNSETIFF, (void *) &ifr);
70 if (ret != 0) {
71 fprintf(stderr, "warning: could not configure /dev/net/tun: no virtual network emulation\n");
72 close(fd);
73 return -1;
74 }
75 pstrcpy(ifname, ifname_size, ifr.ifr_name);
76 fcntl(fd, F_SETFL, O_NONBLOCK);
77 return fd;
78}