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 "qemu/osdep.h"
  26 #include "qemu-common.h"
  27 #include "qapi/error.h"
  28 #include "tap_int.h"
  29 #include "qemu/cutils.h"
  30 #include "sysemu/sysemu.h"
  31 #include "qemu/error-report.h"
  32
  33 #if defined(__NetBSD__) || defined(__FreeBSD__)
  34 #include <sys/ioctl.h>
  35 #include <net/if.h>
  36 #include <net/if_tap.h>
  37 #endif
  38
  39 #if defined(__OpenBSD__)
  40 #include <sys/param.h>
  41 #endif
  42
  43 #ifndef __FreeBSD__
  44 int tap_open(char *ifname, int ifname_size, int *vnet_hdr,
  45              int vnet_hdr_required, int mq_required, Error **errp)
  46 {
  47     int fd;
  48 #ifdef TAPGIFNAME
  49     struct ifreq ifr;
  50 #else
  51     char *dev;
  52     struct stat s;
  53 #endif
  54
  55     /* if no ifname is given, always start the search from tap0/tun0. */
  56     int i;
  57     char dname[100];
  58
  59     for (i = 0; i < 10; i++) {
  60         if (*ifname) {
  61             snprintf(dname, sizeof dname, "/dev/%s", ifname);
  62         } else {
  63 #if defined(__OpenBSD__) && OpenBSD < 201605
  64             snprintf(dname, sizeof dname, "/dev/tun%d", i);
  65 #else
  66             snprintf(dname, sizeof dname, "/dev/tap%d", i);
  67 #endif
  68         }
  69         TFR(fd = open(dname, O_RDWR));
  70         if (fd >= 0) {
  71             break;
  72         }
  73         else if (errno == ENXIO || errno == ENOENT) {
  74             break;
  75         }
  76         if (*ifname) {
  77             break;
  78         }
  79     }
  80     if (fd < 0) {
  81         error_setg_errno(errp, errno, "could not open %s", dname);
  82         return -1;
  83     }
  84
  85 #ifdef TAPGIFNAME
  86     if (ioctl(fd, TAPGIFNAME, (void *)&ifr) < 0) {
  87         error_setg_errno(errp, errno, "could not get tap name");
  88         return -1;
  89     }
  90     pstrcpy(ifname, ifname_size, ifr.ifr_name);
  91 #else
  92     if (fstat(fd, &s) < 0) {
  93         error_setg_errno(errp, errno, "could not stat %s", dname);
  94         return -1;
  95     }
  96     dev = devname(s.st_rdev, S_IFCHR);
  97     pstrcpy(ifname, ifname_size, dev);
  98 #endif
  99
 100     if (*vnet_hdr) {
 101         /* BSD doesn't have IFF_VNET_HDR */
 102         *vnet_hdr = 0;
 103
 104         if (vnet_hdr_required && !*vnet_hdr) {
 105             error_setg(errp, "vnet_hdr=1 requested, but no kernel "
 106                        "support for IFF_VNET_HDR available");
 107             close(fd);
 108             return -1;
 109         }
 110     }
 111     fcntl(fd, F_SETFL, O_NONBLOCK);
 112     return fd;
 113 }
 114
 115 #else /* __FreeBSD__ */
 116
 117 #define PATH_NET_TAP "/dev/tap"
 118
 119 static int tap_open_clone(char *ifname, int ifname_size, Error **errp)
 120 {
 121     int fd, s, ret;
 122     struct ifreq ifr;
 123
 124     TFR(fd = open(PATH_NET_TAP, O_RDWR));
 125     if (fd < 0) {
 126         error_setg_errno(errp, errno, "could not open %s", PATH_NET_TAP);
 127         return -1;
 128     }
 129
 130     memset(&ifr, 0, sizeof(ifr));
 131
 132     ret = ioctl(fd, TAPGIFNAME, (void *)&ifr);
 133     if (ret < 0) {
 134         error_setg_errno(errp, errno, "could not get tap interface name");
 135         close(fd);
 136         return -1;
 137     }
 138
 139     if (ifname[0] != '\0') {
 140         /* User requested the interface to have a specific name */
 141         s = socket(AF_LOCAL, SOCK_DGRAM, 0);
 142         if (s < 0) {
 143             error_setg_errno(errp, errno,
 144                              "could not open socket to set interface name");
 145             close(fd);
 146             return -1;
 147         }
 148         ifr.ifr_data = ifname;
 149         ret = ioctl(s, SIOCSIFNAME, (void *)&ifr);
 150         close(s);
 151         if (ret < 0) {
 152             error_setg(errp, "could not set tap interface name");
 153             close(fd);
 154             return -1;
 155         }
 156     } else {
 157         pstrcpy(ifname, ifname_size, ifr.ifr_name);
 158     }
 159
 160     return fd;
 161 }
 162
 163 int tap_open(char *ifname, int ifname_size, int *vnet_hdr,
 164              int vnet_hdr_required, int mq_required, Error **errp)
 165 {
 166     int fd = -1;
 167
 168     /* If the specified tap device already exists just use it. */
 169     if (ifname[0] != '\0') {
 170         char dname[100];
 171         snprintf(dname, sizeof dname, "/dev/%s", ifname);
 172         TFR(fd = open(dname, O_RDWR));
 173         if (fd < 0 && errno != ENOENT) {
 174             error_setg_errno(errp, errno, "could not open %s", dname);
 175             return -1;
 176         }
 177     }
 178
 179     if (fd < 0) {
 180         /* Tap device not specified or does not exist. */
 181         if ((fd = tap_open_clone(ifname, ifname_size, errp)) < 0) {
 182             return -1;
 183         }
 184     }
 185
 186     if (*vnet_hdr) {
 187         /* BSD doesn't have IFF_VNET_HDR */
 188         *vnet_hdr = 0;
 189
 190         if (vnet_hdr_required && !*vnet_hdr) {
 191             error_setg(errp, "vnet_hdr=1 requested, but no kernel "
 192                        "support for IFF_VNET_HDR available");
 193             goto error;
 194         }
 195     }
 196     if (mq_required) {
 197         error_setg(errp, "mq_required requested, but no kernel support"
 198                    " for IFF_MULTI_QUEUE available");
 199         goto error;
 200     }
 201
 202     fcntl(fd, F_SETFL, O_NONBLOCK);
 203     return fd;
 204
 205 error:
 206     close(fd);
 207     return -1;
 208 }
 209 #endif /* __FreeBSD__ */
 210
 211 void tap_set_sndbuf(int fd, const NetdevTapOptions *tap, Error **errp)
 212 {
 213 }
 214
 215 int tap_probe_vnet_hdr(int fd)
 216 {
 217     return 0;
 218 }
 219
 220 int tap_probe_has_ufo(int fd)
 221 {
 222     return 0;
 223 }
 224
 225 int tap_probe_vnet_hdr_len(int fd, int len)
 226 {
 227     return 0;
 228 }
 229
 230 void tap_fd_set_vnet_hdr_len(int fd, int len)
 231 {
 232 }
 233
 234 int tap_fd_set_vnet_le(int fd, int is_le)
 235 {
 236     return -EINVAL;
 237 }
 238
 239 int tap_fd_set_vnet_be(int fd, int is_be)
 240 {
 241     return -EINVAL;
 242 }
 243
 244 void tap_fd_set_offload(int fd, int csum, int tso4,
 245                         int tso6, int ecn, int ufo)
 246 {
 247 }
 248
 249 int tap_fd_enable(int fd)
 250 {
 251     return -1;
 252 }
 253
 254 int tap_fd_disable(int fd)
 255 {
 256     return -1;
 257 }
 258
 259 int tap_fd_get_ifname(int fd, char *ifname)
 260 {
 261     return -1;
 262 }