qemu

tap-bsd.c (6423B)

---

 /*
  * QEMU System Emulator
  *
  * Copyright (c) 2003-2008 Fabrice Bellard
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
  * in the Software without restriction, including without limitation the rights
  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  * copies of the Software, and to permit persons to whom the Software is
  * furnished to do so, subject to the following conditions:
  *
  * The above copyright notice and this permission notice shall be included in
  * all copies or substantial portions of the Software.
  *
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
 
 #include "qemu/osdep.h"
 #include "qapi/error.h"
 #include "tap_int.h"
 #include "qemu/cutils.h"
 #include "qemu/error-report.h"
 
 #if defined(__NetBSD__) || defined(__FreeBSD__)
 #include <sys/ioctl.h>
 #include <net/if.h>
 #include <net/if_tap.h>
 #endif
 
 #ifndef __FreeBSD__
 int tap_open(char *ifname, int ifname_size, int *vnet_hdr,
              int vnet_hdr_required, int mq_required, Error **errp)
 {
     int fd;
 #ifdef TAPGIFNAME
     struct ifreq ifr;
 #else
     char *dev;
     struct stat s;
 #endif
 
     /* if no ifname is given, always start the search from tap0/tun0. */
     int i;
     char dname[100];
 
     for (i = 0; i < 10; i++) {
         if (*ifname) {
             snprintf(dname, sizeof dname, "/dev/%s", ifname);
         } else {
             snprintf(dname, sizeof dname, "/dev/tap%d", i);
         }
         TFR(fd = open(dname, O_RDWR));
         if (fd >= 0) {
             break;
         }
         else if (errno == ENXIO || errno == ENOENT) {
             break;
         }
         if (*ifname) {
             break;
         }
     }
     if (fd < 0) {
         error_setg_errno(errp, errno, "could not open %s", dname);
         return -1;
     }
 
 #ifdef TAPGIFNAME
     if (ioctl(fd, TAPGIFNAME, (void *)&ifr) < 0) {
         error_setg_errno(errp, errno, "could not get tap name");
         return -1;
     }
     pstrcpy(ifname, ifname_size, ifr.ifr_name);
 #else
     if (fstat(fd, &s) < 0) {
         error_setg_errno(errp, errno, "could not stat %s", dname);
         return -1;
     }
     dev = devname(s.st_rdev, S_IFCHR);
     pstrcpy(ifname, ifname_size, dev);
 #endif
 
     if (*vnet_hdr) {
         /* BSD doesn't have IFF_VNET_HDR */
         *vnet_hdr = 0;
 
         if (vnet_hdr_required && !*vnet_hdr) {
             error_setg(errp, "vnet_hdr=1 requested, but no kernel "
                        "support for IFF_VNET_HDR available");
             close(fd);
             return -1;
         }
     }
     g_unix_set_fd_nonblocking(fd, true, NULL);
     return fd;
 }
 
 #else /* __FreeBSD__ */
 
 #define PATH_NET_TAP "/dev/tap"
 
 static int tap_open_clone(char *ifname, int ifname_size, Error **errp)
 {
     int fd, s, ret;
     struct ifreq ifr;
 
     TFR(fd = open(PATH_NET_TAP, O_RDWR));
     if (fd < 0) {
         error_setg_errno(errp, errno, "could not open %s", PATH_NET_TAP);
         return -1;
     }
 
     memset(&ifr, 0, sizeof(ifr));
 
     ret = ioctl(fd, TAPGIFNAME, (void *)&ifr);
     if (ret < 0) {
         error_setg_errno(errp, errno, "could not get tap interface name");
         close(fd);
         return -1;
     }
 
     if (ifname[0] != '\0') {
         /* User requested the interface to have a specific name */
         s = socket(AF_LOCAL, SOCK_DGRAM, 0);
         if (s < 0) {
             error_setg_errno(errp, errno,
                              "could not open socket to set interface name");
             close(fd);
             return -1;
         }
         ifr.ifr_data = ifname;
         ret = ioctl(s, SIOCSIFNAME, (void *)&ifr);
         close(s);
         if (ret < 0) {
             error_setg(errp, "could not set tap interface name");
             close(fd);
             return -1;
         }
     } else {
         pstrcpy(ifname, ifname_size, ifr.ifr_name);
     }
 
     return fd;
 }
 
 int tap_open(char *ifname, int ifname_size, int *vnet_hdr,
              int vnet_hdr_required, int mq_required, Error **errp)
 {
     int fd = -1;
 
     /* If the specified tap device already exists just use it. */
     if (ifname[0] != '\0') {
         char dname[100];
         snprintf(dname, sizeof dname, "/dev/%s", ifname);
         TFR(fd = open(dname, O_RDWR));
         if (fd < 0 && errno != ENOENT) {
             error_setg_errno(errp, errno, "could not open %s", dname);
             return -1;
         }
     }
 
     if (fd < 0) {
         /* Tap device not specified or does not exist. */
         if ((fd = tap_open_clone(ifname, ifname_size, errp)) < 0) {
             return -1;
         }
     }
 
     if (*vnet_hdr) {
         /* BSD doesn't have IFF_VNET_HDR */
         *vnet_hdr = 0;
 
         if (vnet_hdr_required && !*vnet_hdr) {
             error_setg(errp, "vnet_hdr=1 requested, but no kernel "
                        "support for IFF_VNET_HDR available");
             goto error;
         }
     }
     if (mq_required) {
         error_setg(errp, "mq_required requested, but no kernel support"
                    " for IFF_MULTI_QUEUE available");
         goto error;
     }
 
     g_unix_set_fd_nonblocking(fd, true, NULL);
     return fd;
 
 error:
     close(fd);
     return -1;
 }
 #endif /* __FreeBSD__ */
 
 void tap_set_sndbuf(int fd, const NetdevTapOptions *tap, Error **errp)
 {
 }
 
 int tap_probe_vnet_hdr(int fd, Error **errp)
 {
     return 0;
 }
 
 int tap_probe_has_ufo(int fd)
 {
     return 0;
 }
 
 int tap_probe_vnet_hdr_len(int fd, int len)
 {
     return 0;
 }
 
 void tap_fd_set_vnet_hdr_len(int fd, int len)
 {
 }
 
 int tap_fd_set_vnet_le(int fd, int is_le)
 {
     return -EINVAL;
 }
 
 int tap_fd_set_vnet_be(int fd, int is_be)
 {
     return -EINVAL;
 }
 
 void tap_fd_set_offload(int fd, int csum, int tso4,
                         int tso6, int ecn, int ufo)
 {
 }
 
 int tap_fd_enable(int fd)
 {
     return -1;
 }
 
 int tap_fd_disable(int fd)
 {
     return -1;
 }
 
 int tap_fd_get_ifname(int fd, char *ifname)
 {
     return -1;
 }
 
 int tap_fd_set_steering_ebpf(int fd, int prog_fd)
 {
     return -1;
 }