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 <sys/ioctl.h>
  32 #include <net/if.h>
  33 #include <net/if_tap.h>
  34 #endif
  35
  36 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__) || defined(__DragonFly__)
  37 #include <libutil.h>
  38 #else
  39 #include <util.h>
  40 #endif
  41
  42 int tap_open(char *ifname, int ifname_size, int *vnet_hdr, int vnet_hdr_required)
  43 {
  44     int fd;
  45 #ifdef TAPGIFNAME
  46     struct ifreq ifr;
  47 #else
  48     char *dev;
  49     struct stat s;
  50 #endif
  51
  52 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__) || defined(__OpenBSD__)
  53     /* if no ifname is given, always start the search from tap0/tun0. */
  54     int i;
  55     char dname[100];
  56
  57     for (i = 0; i < 10; i++) {
  58         if (*ifname) {
  59             snprintf(dname, sizeof dname, "/dev/%s", ifname);
  60         } else {
  61 #if defined(__OpenBSD__)
  62             snprintf(dname, sizeof dname, "/dev/tun%d", i);
  63 #else
  64             snprintf(dname, sizeof dname, "/dev/tap%d", i);
  65 #endif
  66         }
  67         TFR(fd = open(dname, O_RDWR));
  68         if (fd >= 0) {
  69             break;
  70         }
  71         else if (errno == ENXIO || errno == ENOENT) {
  72             break;
  73         }
  74         if (*ifname) {
  75             break;
  76         }
  77     }
  78     if (fd < 0) {
  79         error_report("warning: could not open %s (%s): no virtual network emulation",
  80                    dname, strerror(errno));
  81         return -1;
  82     }
  83 #else
  84     TFR(fd = open("/dev/tap", O_RDWR));
  85     if (fd < 0) {
  86         fprintf(stderr,
  87             "warning: could not open /dev/tap: no virtual network emulation: %s\n",
  88             strerror(errno));
  89         return -1;
  90     }
  91 #endif
  92
  93 #ifdef TAPGIFNAME
  94     if (ioctl(fd, TAPGIFNAME, (void *)&ifr) < 0) {
  95         fprintf(stderr, "warning: could not get tap name: %s\n",
  96             strerror(errno));
  97         return -1;
  98     }
  99     pstrcpy(ifname, ifname_size, ifr.ifr_name);
 100 #else
 101     if (fstat(fd, &s) < 0) {
 102         fprintf(stderr,
 103             "warning: could not stat /dev/tap: no virtual network emulation: %s\n",
 104             strerror(errno));
 105         return -1;
 106     }
 107     dev = devname(s.st_rdev, S_IFCHR);
 108     pstrcpy(ifname, ifname_size, dev);
 109 #endif
 110
 111     if (*vnet_hdr) {
 112         /* BSD doesn't have IFF_VNET_HDR */
 113         *vnet_hdr = 0;
 114
 115         if (vnet_hdr_required && !*vnet_hdr) {
 116             error_report("vnet_hdr=1 requested, but no kernel "
 117                          "support for IFF_VNET_HDR available");
 118             close(fd);
 119             return -1;
 120         }
 121     }
 122     fcntl(fd, F_SETFL, O_NONBLOCK);
 123     return fd;
 124 }
 125
 126 int tap_set_sndbuf(int fd, QemuOpts *opts)
 127 {
 128     return 0;
 129 }
 130
 131 int tap_probe_vnet_hdr(int fd)
 132 {
 133     return 0;
 134 }
 135
 136 int tap_probe_has_ufo(int fd)
 137 {
 138     return 0;
 139 }
 140
 141 int tap_probe_vnet_hdr_len(int fd, int len)
 142 {
 143     return 0;
 144 }
 145
 146 void tap_fd_set_vnet_hdr_len(int fd, int len)
 147 {
 148 }
 149
 150 void tap_fd_set_offload(int fd, int csum, int tso4,
 151                         int tso6, int ecn, int ufo)
 152 {
 153 }