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