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