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