net/tap-bsd.c

   1 /*
   2  * QEMU System Emulator
   3  *
   4  * Copyright (c) 2003-2008 Fabrice Bellard
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a copy
   7  * of this software and associated documentation files (the "Software"), to deal
   8  * in the Software without restriction, including without limitation the rights
   9  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  10  * copies of the Software, and to permit persons to whom the Software is
  11  * furnished to do so, subject to the following conditions:
  12  *
  13  * The above copyright notice and this permission notice shall be included in
  14  * all copies or substantial portions of the Software.
  15  *
  16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  21  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  22  * THE SOFTWARE.
  23  */
  24
  25 #include "net/tap.h"
  26 #include "qemu-common.h"
  27 #include "sysemu.h"
  28 #include "qemu-error.h"
  29
  30 #ifdef __NetBSD__
  31 #include <net/if_tap.h>
  32 #endif
  33
  34 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__) || defined(__DragonFly__)
  35 #include <libutil.h>
  36 #else
  37 #include <util.h>
  38 #endif
  39
  40 int tap_open(char *ifname, int ifname_size, int *vnet_hdr, int vnet_hdr_required)
  41 {
  42     int fd;
  43     char *dev;
  44     struct stat s;
  45
  46 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__) || defined(__OpenBSD__)
  47     /* if no ifname is given, always start the search from tap0/tun0. */
  48     int i;
  49     char dname[100];
  50
  51     for (i = 0; i < 10; i++) {
  52         if (*ifname) {
  53             snprintf(dname, sizeof dname, "/dev/%s", ifname);
  54         } else {
  55 #if defined(__OpenBSD__)
  56             snprintf(dname, sizeof dname, "/dev/tun%d", i);
  57 #else
  58             snprintf(dname, sizeof dname, "/dev/tap%d", i);
  59 #endif
  60         }
  61         TFR(fd = open(dname, O_RDWR));
  62         if (fd >= 0) {
  63             break;
  64         }
  65         else if (errno == ENXIO || errno == ENOENT) {
  66             break;
  67         }
  68         if (*ifname) {
  69             break;
  70         }
  71     }
  72     if (fd < 0) {
  73         error_report("warning: could not open %s (%s): no virtual network emulation",
  74                    dname, strerror(errno));
  75         return -1;
  76     }
  77 #else
  78     TFR(fd = open("/dev/tap", O_RDWR));
  79     if (fd < 0) {
  80         fprintf(stderr, "warning: could not open /dev/tap: no virtual network emulation\n");
  81         return -1;
  82     }
  83 #endif
  84
  85     fstat(fd, &s);
  86     dev = devname(s.st_rdev, S_IFCHR);
  87     pstrcpy(ifname, ifname_size, dev);
  88
  89     if (*vnet_hdr) {
  90         /* BSD doesn't have IFF_VNET_HDR */
  91         *vnet_hdr = 0;
  92
  93         if (vnet_hdr_required && !*vnet_hdr) {
  94             error_report("vnet_hdr=1 requested, but no kernel "
  95                          "support for IFF_VNET_HDR available");
  96             close(fd);
  97             return -1;
  98         }
  99     }
 100     fcntl(fd, F_SETFL, O_NONBLOCK);
 101     return fd;
 102 }
 103
 104 int tap_set_sndbuf(int fd, QemuOpts *opts)
 105 {
 106     return 0;
 107 }
 108
 109 int tap_probe_vnet_hdr(int fd)
 110 {
 111     return 0;
 112 }
 113
 114 int tap_probe_has_ufo(int fd)
 115 {
 116     return 0;
 117 }
 118
 119 int tap_probe_vnet_hdr_len(int fd, int len)
 120 {
 121     return 0;
 122 }
 123
 124 void tap_fd_set_vnet_hdr_len(int fd, int len)
 125 {
 126 }
 127
 128 void tap_fd_set_offload(int fd, int csum, int tso4,
 129                         int tso6, int ecn, int ufo)
 130 {
 131 }