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, Error **errp)
  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_setg_errno(errp, errno, "could not open %s", dname);
  75         return -1;
  76     }
  77
  78 #ifdef TAPGIFNAME
  79     if (ioctl(fd, TAPGIFNAME, (void *)&ifr) < 0) {
  80         error_setg_errno(errp, errno, "could not get tap name");
  81         return -1;
  82     }
  83     pstrcpy(ifname, ifname_size, ifr.ifr_name);
  84 #else
  85     if (fstat(fd, &s) < 0) {
  86         error_setg_errno(errp, errno, "could not stat %s", dname);
  87         return -1;
  88     }
  89     dev = devname(s.st_rdev, S_IFCHR);
  90     pstrcpy(ifname, ifname_size, dev);
  91 #endif
  92
  93     if (*vnet_hdr) {
  94         /* BSD doesn't have IFF_VNET_HDR */
  95         *vnet_hdr = 0;
  96
  97         if (vnet_hdr_required && !*vnet_hdr) {
  98             error_setg(errp, "vnet_hdr=1 requested, but no kernel "
  99                        "support for IFF_VNET_HDR available");
 100             close(fd);
 101             return -1;
 102         }
 103     }
 104     fcntl(fd, F_SETFL, O_NONBLOCK);
 105     return fd;
 106 }
 107
 108 #else /* __FreeBSD__ */
 109
 110 #define PATH_NET_TAP "/dev/tap"
 111
 112 static int tap_open_clone(char *ifname, int ifname_size, Error **errp)
 113 {
 114     int fd, s, ret;
 115     struct ifreq ifr;
 116
 117     TFR(fd = open(PATH_NET_TAP, O_RDWR));
 118     if (fd < 0) {
 119         error_setg_errno(errp, errno, "could not open %s", PATH_NET_TAP);
 120         return -1;
 121     }
 122
 123     memset(&ifr, 0, sizeof(ifr));
 124
 125     ret = ioctl(fd, TAPGIFNAME, (void *)&ifr);
 126     if (ret < 0) {
 127         error_setg_errno(errp, errno, "could not get tap interface name");
 128         close(fd);
 129         return -1;
 130     }
 131
 132     if (ifname[0] != '\0') {
 133         /* User requested the interface to have a specific name */
 134         s = socket(AF_LOCAL, SOCK_DGRAM, 0);
 135         if (s < 0) {
 136             error_setg_errno(errp, errno,
 137                              "could not open socket to set interface name");
 138             close(fd);
 139             return -1;
 140         }
 141         ifr.ifr_data = ifname;
 142         ret = ioctl(s, SIOCSIFNAME, (void *)&ifr);
 143         close(s);
 144         if (ret < 0) {
 145             error_setg(errp, "could not set tap interface name");
 146             close(fd);
 147             return -1;
 148         }
 149     } else {
 150         pstrcpy(ifname, ifname_size, ifr.ifr_name);
 151     }
 152
 153     return fd;
 154 }
 155
 156 int tap_open(char *ifname, int ifname_size, int *vnet_hdr,
 157              int vnet_hdr_required, int mq_required, Error **errp)
 158 {
 159     int fd = -1;
 160
 161     /* If the specified tap device already exists just use it. */
 162     if (ifname[0] != '\0') {
 163         char dname[100];
 164         snprintf(dname, sizeof dname, "/dev/%s", ifname);
 165         TFR(fd = open(dname, O_RDWR));
 166         if (fd < 0 && errno != ENOENT) {
 167             error_setg_errno(errp, errno, "could not open %s", dname);
 168             return -1;
 169         }
 170     }
 171
 172     if (fd < 0) {
 173         /* Tap device not specified or does not exist. */
 174         if ((fd = tap_open_clone(ifname, ifname_size, errp)) < 0) {
 175             return -1;
 176         }
 177     }
 178
 179     if (*vnet_hdr) {
 180         /* BSD doesn't have IFF_VNET_HDR */
 181         *vnet_hdr = 0;
 182
 183         if (vnet_hdr_required && !*vnet_hdr) {
 184             error_setg(errp, "vnet_hdr=1 requested, but no kernel "
 185                        "support for IFF_VNET_HDR available");
 186             goto error;
 187         }
 188     }
 189     if (mq_required) {
 190         error_setg(errp, "mq_required requested, but no kernel support"
 191                    " for IFF_MULTI_QUEUE available");
 192         goto error;
 193     }
 194
 195     fcntl(fd, F_SETFL, O_NONBLOCK);
 196     return fd;
 197
 198 error:
 199     close(fd);
 200     return -1;
 201 }
 202 #endif /* __FreeBSD__ */
 203
 204 void tap_set_sndbuf(int fd, const NetdevTapOptions *tap, Error **errp)
 205 {
 206 }
 207
 208 int tap_probe_vnet_hdr(int fd)
 209 {
 210     return 0;
 211 }
 212
 213 int tap_probe_has_ufo(int fd)
 214 {
 215     return 0;
 216 }
 217
 218 int tap_probe_vnet_hdr_len(int fd, int len)
 219 {
 220     return 0;
 221 }
 222
 223 void tap_fd_set_vnet_hdr_len(int fd, int len)
 224 {
 225 }
 226
 227 int tap_fd_set_vnet_le(int fd, int is_le)
 228 {
 229     return -EINVAL;
 230 }
 231
 232 int tap_fd_set_vnet_be(int fd, int is_be)
 233 {
 234     return -EINVAL;
 235 }
 236
 237 void tap_fd_set_offload(int fd, int csum, int tso4,
 238                         int tso6, int ecn, int ufo)
 239 {
 240 }
 241
 242 int tap_fd_enable(int fd)
 243 {
 244     return -1;
 245 }
 246
 247 int tap_fd_disable(int fd)
 248 {
 249     return -1;
 250 }
 251
 252 int tap_fd_get_ifname(int fd, char *ifname)
 253 {
 254     return -1;
 255 }