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![Jason Wang](/assets/img/avatar_default.png)
This patch introduces a helper tap_get_ifname() to get the device name of tap device. This is needed when ifname is unspecified in the command line and qemu were asked to create tap device by itself. In this situation, the name were allocated by kernel, so if multiqueue is asked, we need to fetch its name after creating the first queue. Only linux has this support since it's the only platform that supports multiqueue tap. Signed-off-by: Jason Wang <jasowang@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
163 lines
4 KiB
C
163 lines
4 KiB
C
/*
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* QEMU System Emulator
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*
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* Copyright (c) 2003-2008 Fabrice Bellard
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this software and associated documentation files (the "Software"), to deal
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* in the Software without restriction, including without limitation the rights
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* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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* copies of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in
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* all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
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* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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* THE SOFTWARE.
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*/
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#include "tap_int.h"
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#include "qemu-common.h"
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#include "sysemu/sysemu.h"
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#include "qemu/error-report.h"
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#ifdef __NetBSD__
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#include <sys/ioctl.h>
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#include <net/if.h>
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#include <net/if_tap.h>
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#endif
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int tap_open(char *ifname, int ifname_size, int *vnet_hdr, int vnet_hdr_required)
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{
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int fd;
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#ifdef TAPGIFNAME
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struct ifreq ifr;
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#else
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char *dev;
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struct stat s;
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#endif
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#if defined(__FreeBSD__) || defined(__FreeBSD_kernel__) || defined(__OpenBSD__)
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/* if no ifname is given, always start the search from tap0/tun0. */
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int i;
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char dname[100];
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for (i = 0; i < 10; i++) {
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if (*ifname) {
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snprintf(dname, sizeof dname, "/dev/%s", ifname);
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} else {
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#if defined(__OpenBSD__)
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snprintf(dname, sizeof dname, "/dev/tun%d", i);
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#else
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snprintf(dname, sizeof dname, "/dev/tap%d", i);
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#endif
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}
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TFR(fd = open(dname, O_RDWR));
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if (fd >= 0) {
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break;
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}
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else if (errno == ENXIO || errno == ENOENT) {
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break;
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}
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if (*ifname) {
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break;
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}
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}
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if (fd < 0) {
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error_report("warning: could not open %s (%s): no virtual network emulation",
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dname, strerror(errno));
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return -1;
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}
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#else
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TFR(fd = open("/dev/tap", O_RDWR));
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if (fd < 0) {
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fprintf(stderr,
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"warning: could not open /dev/tap: no virtual network emulation: %s\n",
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strerror(errno));
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return -1;
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}
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#endif
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#ifdef TAPGIFNAME
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if (ioctl(fd, TAPGIFNAME, (void *)&ifr) < 0) {
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fprintf(stderr, "warning: could not get tap name: %s\n",
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strerror(errno));
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return -1;
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}
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pstrcpy(ifname, ifname_size, ifr.ifr_name);
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#else
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if (fstat(fd, &s) < 0) {
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fprintf(stderr,
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"warning: could not stat /dev/tap: no virtual network emulation: %s\n",
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strerror(errno));
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return -1;
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}
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dev = devname(s.st_rdev, S_IFCHR);
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pstrcpy(ifname, ifname_size, dev);
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#endif
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if (*vnet_hdr) {
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/* BSD doesn't have IFF_VNET_HDR */
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*vnet_hdr = 0;
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if (vnet_hdr_required && !*vnet_hdr) {
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error_report("vnet_hdr=1 requested, but no kernel "
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"support for IFF_VNET_HDR available");
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close(fd);
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return -1;
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}
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}
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fcntl(fd, F_SETFL, O_NONBLOCK);
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return fd;
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}
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int tap_set_sndbuf(int fd, const NetdevTapOptions *tap)
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{
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return 0;
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}
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int tap_probe_vnet_hdr(int fd)
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{
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return 0;
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}
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int tap_probe_has_ufo(int fd)
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{
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return 0;
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}
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int tap_probe_vnet_hdr_len(int fd, int len)
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{
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return 0;
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}
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void tap_fd_set_vnet_hdr_len(int fd, int len)
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{
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}
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void tap_fd_set_offload(int fd, int csum, int tso4,
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int tso6, int ecn, int ufo)
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{
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}
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int tap_fd_enable(int fd)
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{
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return -1;
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}
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int tap_fd_disable(int fd)
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{
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return -1;
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}
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int tap_fd_get_ifname(int fd, char *ifname)
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{
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return -1;
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}
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