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