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 "qapi/error.h"
  27 #include "tap_int.h"
  28 #include "qemu/cutils.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             snprintf(dname, sizeof dname, "/dev/tap%d", i);
  58         }
  59         fd = RETRY_ON_EINTR(open(dname, O_RDWR));
  60         if (fd >= 0) {
  61             break;
  62         }
  63         else if (errno == ENXIO || errno == ENOENT) {
  64             break;
  65         }
  66         if (*ifname) {
  67             break;
  68         }
  69     }
  70     if (fd < 0) {
  71         error_setg_errno(errp, errno, "could not open %s", dname);
  72         return -1;
  73     }
  74
  75 #ifdef TAPGIFNAME
  76     if (ioctl(fd, TAPGIFNAME, (void *)&ifr) < 0) {
  77         error_setg_errno(errp, errno, "could not get tap name");
  78         return -1;
  79     }
  80     pstrcpy(ifname, ifname_size, ifr.ifr_name);
  81 #else
  82     if (fstat(fd, &s) < 0) {
  83         error_setg_errno(errp, errno, "could not stat %s", dname);
  84         return -1;
  85     }
  86     dev = devname(s.st_rdev, S_IFCHR);
  87     pstrcpy(ifname, ifname_size, dev);
  88 #endif
  89
  90     if (*vnet_hdr) {
  91         /* BSD doesn't have IFF_VNET_HDR */
  92         *vnet_hdr = 0;
  93
  94         if (vnet_hdr_required && !*vnet_hdr) {
  95             error_setg(errp, "vnet_hdr=1 requested, but no kernel "
  96                        "support for IFF_VNET_HDR available");
  97             close(fd);
  98             return -1;
  99         }
 100     }
 101     g_unix_set_fd_nonblocking(fd, true, NULL);
 102     return fd;
 103 }
 104
 105 #else /* __FreeBSD__ */
 106
 107 #define PATH_NET_TAP "/dev/tap"
 108
 109 static int tap_open_clone(char *ifname, int ifname_size, Error **errp)
 110 {
 111     int fd, s, ret;
 112     struct ifreq ifr;
 113
 114     fd = RETRY_ON_EINTR(open(PATH_NET_TAP, O_RDWR));
 115     if (fd < 0) {
 116         error_setg_errno(errp, errno, "could not open %s", PATH_NET_TAP);
 117         return -1;
 118     }
 119
 120     memset(&ifr, 0, sizeof(ifr));
 121
 122     ret = ioctl(fd, TAPGIFNAME, (void *)&ifr);
 123     if (ret < 0) {
 124         error_setg_errno(errp, errno, "could not get tap interface name");
 125         close(fd);
 126         return -1;
 127     }
 128
 129     if (ifname[0] != '\0') {
 130         /* User requested the interface to have a specific name */
 131         s = socket(AF_LOCAL, SOCK_DGRAM, 0);
 132         if (s < 0) {
 133             error_setg_errno(errp, errno,
 134                              "could not open socket to set interface name");
 135             close(fd);
 136             return -1;
 137         }
 138         ifr.ifr_data = ifname;
 139         ret = ioctl(s, SIOCSIFNAME, (void *)&ifr);
 140         close(s);
 141         if (ret < 0) {
 142             error_setg(errp, "could not set tap interface name");
 143             close(fd);
 144             return -1;
 145         }
 146     } else {
 147         pstrcpy(ifname, ifname_size, ifr.ifr_name);
 148     }
 149
 150     return fd;
 151 }
 152
 153 int tap_open(char *ifname, int ifname_size, int *vnet_hdr,
 154              int vnet_hdr_required, int mq_required, Error **errp)
 155 {
 156     int fd = -1;
 157
 158     /* If the specified tap device already exists just use it. */
 159     if (ifname[0] != '\0') {
 160         char dname[100];
 161         snprintf(dname, sizeof dname, "/dev/%s", ifname);
 162         fd = RETRY_ON_EINTR(open(dname, O_RDWR));
 163         if (fd < 0 && errno != ENOENT) {
 164             error_setg_errno(errp, errno, "could not open %s", dname);
 165             return -1;
 166         }
 167     }
 168
 169     if (fd < 0) {
 170         /* Tap device not specified or does not exist. */
 171         if ((fd = tap_open_clone(ifname, ifname_size, errp)) < 0) {
 172             return -1;
 173         }
 174     }
 175
 176     if (*vnet_hdr) {
 177         /* BSD doesn't have IFF_VNET_HDR */
 178         *vnet_hdr = 0;
 179
 180         if (vnet_hdr_required && !*vnet_hdr) {
 181             error_setg(errp, "vnet_hdr=1 requested, but no kernel "
 182                        "support for IFF_VNET_HDR available");
 183             goto error;
 184         }
 185     }
 186     if (mq_required) {
 187         error_setg(errp, "mq_required requested, but no kernel support"
 188                    " for IFF_MULTI_QUEUE available");
 189         goto error;
 190     }
 191
 192     g_unix_set_fd_nonblocking(fd, true, NULL);
 193     return fd;
 194
 195 error:
 196     close(fd);
 197     return -1;
 198 }
 199 #endif /* __FreeBSD__ */
 200
 201 void tap_set_sndbuf(int fd, const NetdevTapOptions *tap, Error **errp)
 202 {
 203 }
 204
 205 int tap_probe_vnet_hdr(int fd, Error **errp)
 206 {
 207     return 0;
 208 }
 209
 210 int tap_probe_has_ufo(int fd)
 211 {
 212     return 0;
 213 }
 214
 215 int tap_probe_has_uso(int fd)
 216 {
 217     return 0;
 218 }
 219
 220 void tap_fd_set_vnet_hdr_len(int fd, int len)
 221 {
 222 }
 223
 224 int tap_fd_set_vnet_le(int fd, int is_le)
 225 {
 226     return -EINVAL;
 227 }
 228
 229 int tap_fd_set_vnet_be(int fd, int is_be)
 230 {
 231     return -EINVAL;
 232 }
 233
 234 void tap_fd_set_offload(int fd, int csum, int tso4,
 235                         int tso6, int ecn, int ufo, int uso4, int uso6)
 236 {
 237 }
 238
 239 int tap_fd_enable(int fd)
 240 {
 241     return -1;
 242 }
 243
 244 int tap_fd_disable(int fd)
 245 {
 246     return -1;
 247 }
 248
 249 int tap_fd_get_ifname(int fd, char *ifname)
 250 {
 251     return -1;
 252 }
 253
 254 int tap_fd_set_steering_ebpf(int fd, int prog_fd)
 255 {
 256     return -1;
 257 }