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 "tap_int.h"
  26 #include "qemu-common.h"
  27 #include "sysemu/sysemu.h"
  28 #include "qemu/error-report.h"
  29
  30 #if defined(__NetBSD__) || defined(__FreeBSD__)
  31 #include <sys/ioctl.h>
  32 #include <net/if.h>
  33 #include <net/if_tap.h>
  34 #endif
  35
  36 #ifndef __FreeBSD__
  37 int tap_open(char *ifname, int ifname_size, int *vnet_hdr,
  38              int vnet_hdr_required, int mq_required)
  39 {
  40     int fd;
  41 #ifdef TAPGIFNAME
  42     struct ifreq ifr;
  43 #else
  44     char *dev;
  45     struct stat s;
  46 #endif
  47
  48     /* if no ifname is given, always start the search from tap0/tun0. */
  49     int i;
  50     char dname[100];
  51
  52     for (i = 0; i < 10; i++) {
  53         if (*ifname) {
  54             snprintf(dname, sizeof dname, "/dev/%s", ifname);
  55         } else {
  56 #if defined(__OpenBSD__)
  57             snprintf(dname, sizeof dname, "/dev/tun%d", i);
  58 #else
  59             snprintf(dname, sizeof dname, "/dev/tap%d", i);
  60 #endif
  61         }
  62         TFR(fd = open(dname, O_RDWR));
  63         if (fd >= 0) {
  64             break;
  65         }
  66         else if (errno == ENXIO || errno == ENOENT) {
  67             break;
  68         }
  69         if (*ifname) {
  70             break;
  71         }
  72     }
  73     if (fd < 0) {
  74         error_report("warning: could not open %s (%s): no virtual network emulation",
  75                    dname, strerror(errno));
  76         return -1;
  77     }
  78
  79 #ifdef TAPGIFNAME
  80     if (ioctl(fd, TAPGIFNAME, (void *)&ifr) < 0) {
  81         fprintf(stderr, "warning: could not get tap name: %s\n",
  82             strerror(errno));
  83         return -1;
  84     }
  85     pstrcpy(ifname, ifname_size, ifr.ifr_name);
  86 #else
  87     if (fstat(fd, &s) < 0) {
  88         fprintf(stderr,
  89             "warning: could not stat /dev/tap: no virtual network emulation: %s\n",
  90             strerror(errno));
  91         return -1;
  92     }
  93     dev = devname(s.st_rdev, S_IFCHR);
  94     pstrcpy(ifname, ifname_size, dev);
  95 #endif
  96
  97     if (*vnet_hdr) {
  98         /* BSD doesn't have IFF_VNET_HDR */
  99         *vnet_hdr = 0;
 100
 101         if (vnet_hdr_required && !*vnet_hdr) {
 102             error_report("vnet_hdr=1 requested, but no kernel "
 103                          "support for IFF_VNET_HDR available");
 104             close(fd);
 105             return -1;
 106         }
 107     }
 108     fcntl(fd, F_SETFL, O_NONBLOCK);
 109     return fd;
 110 }
 111
 112 #else /* __FreeBSD__ */
 113
 114 #define PATH_NET_TAP "/dev/tap"
 115
 116 int tap_open(char *ifname, int ifname_size, int *vnet_hdr,
 117              int vnet_hdr_required, int mq_required)
 118 {
 119     int fd, s, ret;
 120     struct ifreq ifr;
 121
 122     TFR(fd = open(PATH_NET_TAP, O_RDWR));
 123     if (fd < 0) {
 124         error_report("could not open %s: %s", PATH_NET_TAP, strerror(errno));
 125         return -1;
 126     }
 127
 128     memset(&ifr, 0, sizeof(ifr));
 129
 130     ret = ioctl(fd, TAPGIFNAME, (void *)&ifr);
 131     if (ret < 0) {
 132         error_report("could not get tap interface name");
 133         goto error;
 134     }
 135
 136     if (ifname[0] != '\0') {
 137         /* User requested the interface to have a specific name */
 138         s = socket(AF_LOCAL, SOCK_DGRAM, 0);
 139         if (s < 0) {
 140             error_report("could not open socket to set interface name");
 141             goto error;
 142         }
 143         ifr.ifr_data = ifname;
 144         ret = ioctl(s, SIOCSIFNAME, (void *)&ifr);
 145         close(s);
 146         if (ret < 0) {
 147             error_report("could not set tap interface name");
 148             goto error;
 149         }
 150     } else {
 151         pstrcpy(ifname, ifname_size, ifr.ifr_name);
 152     }
 153
 154     if (*vnet_hdr) {
 155         /* BSD doesn't have IFF_VNET_HDR */
 156         *vnet_hdr = 0;
 157
 158         if (vnet_hdr_required && !*vnet_hdr) {
 159             error_report("vnet_hdr=1 requested, but no kernel "
 160                          "support for IFF_VNET_HDR available");
 161             goto error;
 162         }
 163     }
 164     if (mq_required) {
 165         error_report("mq_required requested, but not kernel support"
 166                      "for IFF_MULTI_QUEUE available");
 167         goto error;
 168     }
 169
 170     fcntl(fd, F_SETFL, O_NONBLOCK);
 171     return fd;
 172
 173 error:
 174     close(fd);
 175     return -1;
 176 }
 177 #endif /* __FreeBSD__ */
 178
 179 int tap_set_sndbuf(int fd, const NetdevTapOptions *tap)
 180 {
 181     return 0;
 182 }
 183
 184 int tap_probe_vnet_hdr(int fd)
 185 {
 186     return 0;
 187 }
 188
 189 int tap_probe_has_ufo(int fd)
 190 {
 191     return 0;
 192 }
 193
 194 int tap_probe_vnet_hdr_len(int fd, int len)
 195 {
 196     return 0;
 197 }
 198
 199 void tap_fd_set_vnet_hdr_len(int fd, int len)
 200 {
 201 }
 202
 203 void tap_fd_set_offload(int fd, int csum, int tso4,
 204                         int tso6, int ecn, int ufo)
 205 {
 206 }
 207
 208 int tap_fd_enable(int fd)
 209 {
 210     return -1;
 211 }
 212
 213 int tap_fd_disable(int fd)
 214 {
 215     return -1;
 216 }
 217
 218 int tap_fd_get_ifname(int fd, char *ifname)
 219 {
 220     return -1;
 221 }