libvirt/src/util/virnetdevtap.c
Eric Blake 955af4d4c1 maint: avoid 'const fooPtr' in virnet files
'const fooPtr' is the same as 'foo * const' (the pointer won't
change, but it's contents can).  But in general, if an interface
is trying to be const-correct, it should be using 'const foo *'
(the pointer is to data that can't be changed).

Fix up remaining offenders in src/util.

* src/util/virnetdev.h (virNetDevSetMAC)
(virNetDevReplaceMacAddress, virNetDevValidateConfig)
(virNetDevReplaceNetConfig): Use intended type.
* src/util/virnetdevbandwidth.h (virNetDevBandwidthCopy)
(virNetDevBandwidthPlug): Likewise.
* src/util/virnetdevmacvlan.h (virNetDevMacVLanCreate)
(virNetDevMacVLanCreateWithVPortProfile)
(virNetDevMacVLanDeleteWithVPortProfile)
(virNetDevMacVLanRestartWithVPortProfile)
(virNetDevMacVLanVPortProfileRegisterCallback): Likewise.
* src/util/virnetdevopenvswitch.h (virNetDevOpenvswitchAddPort):
Likewise.
* src/util/virnetdevtap.h (virNetDevTapCreateInBridgePort):
Likewise.
* src/util/virnetdevvlan.h (virNetDevVlanEqual)
(virNetDevVlanCopy): Likewise.
* src/util/virnetdevvportprofile.h
(virNetDevVPortProfileAssociate)
(virNetDevVPortProfileDisassociate): Likewise.
* src/util/virnetlink.h (virNetlinkEventRemoveCallback)
(virNetlinkEventAddClient, virNetlinkEventRemoveClient):
Likewise.
* src/util/virnetdev.c (virNetDevSetMAC)
(virNetDevReplaceMacAddress, virNetDevValidateConfig)
(virNetDevReplaceNetConfig): Fix fallout.
* src/util/virnetdevbandwidth.c (virNetDevBandwidthCopy)
(virNetDevBandwidthPlug): Likewise.
* src/util/virnetdevmacvlan.c (virNetDevMacVLanCreate)
(virNetDevMacVLanCreateWithVPortProfile)
(virNetDevMacVLanDeleteWithVPortProfile)
(virNetDevMacVLanRestartWithVPortProfile)
(virNetDevMacVLanVPortProfileRegisterCallback): Likewise.
* src/util/virnetdevopenvswitch.c (virNetDevOpenvswitchAddPort):
Likewise.
* src/util/virnetdevtap.c (virNetDevTapCreateInBridgePort):
Likewise.
* src/util/virnetdevvlan.c (virNetDevVlanEqual)
(virNetDevVlanCopy): Likewise.
* src/util/virnetdevvportprofile.c
(virNetDevVPortProfileAssociate)
(virNetDevVPortProfileDisassociate)
(virNetDevVPortProfileOpSetLink, virNetDevVPortProfileOpCommon)
(virNetDevVPortProfileOp8021Qbg, virNetDevVPortProfileOp8021Qbh):
Likewise.
* src/util/virnetlink.c (virNetlinkEventRemoveCallback)
(virNetlinkEventAddClient, virNetlinkEventRemoveClient):
Likewise.

Signed-off-by: Eric Blake <eblake@redhat.com>
2013-10-14 13:05:34 -06:00

507 lines
15 KiB
C

/*
* Copyright (C) 2007-2013 Red Hat, Inc.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library. If not, see
* <http://www.gnu.org/licenses/>.
*
* Authors:
* Mark McLoughlin <markmc@redhat.com>
* Daniel P. Berrange <berrange@redhat.com>
*/
#include <config.h>
#include "virmacaddr.h"
#include "virnetdevtap.h"
#include "virnetdev.h"
#include "virnetdevbridge.h"
#include "virnetdevopenvswitch.h"
#include "virerror.h"
#include "virfile.h"
#include "viralloc.h"
#include "virlog.h"
#include "virstring.h"
#include <sys/ioctl.h>
#include <net/if.h>
#include <fcntl.h>
#ifdef __linux__
# include <linux/if_tun.h> /* IFF_TUN, IFF_NO_PI */
#endif
#define VIR_FROM_THIS VIR_FROM_NONE
/**
* virNetDevTapGetName:
* @tapfd: a tun/tap file descriptor
* @ifname: a pointer that will receive the interface name
*
* Retrieve the interface name given a file descriptor for a tun/tap
* interface.
*
* Returns 0 if the interface name is successfully queried, -1 otherwise
*/
int
virNetDevTapGetName(int tapfd ATTRIBUTE_UNUSED, char **ifname ATTRIBUTE_UNUSED)
{
#ifdef TUNGETIFF
struct ifreq ifr;
if (ioctl(tapfd, TUNGETIFF, &ifr) < 0) {
virReportSystemError(errno, "%s",
_("Unable to query tap interface name"));
return -1;
}
return VIR_STRDUP(*ifname, ifr.ifr_name) < 0 ? -1 : 0;
#else
return -1;
#endif
}
/**
* virNetDevProbeVnetHdr:
* @tapfd: a tun/tap file descriptor
*
* Check whether it is safe to enable the IFF_VNET_HDR flag on the
* tap interface.
*
* Setting IFF_VNET_HDR enables QEMU's virtio_net driver to allow
* guests to pass larger (GSO) packets, with partial checksums, to
* the host. This greatly increases the achievable throughput.
*
* It is only useful to enable this when we're setting up a virtio
* interface. And it is only *safe* to enable it when we know for
* sure that a) qemu has support for IFF_VNET_HDR and b) the running
* kernel implements the TUNGETIFF ioctl(), which qemu needs to query
* the supplied tapfd.
*
* Returns 1 if VnetHdr is supported, 0 if not supported
*/
#ifdef IFF_VNET_HDR
static int
virNetDevProbeVnetHdr(int tapfd)
{
# if defined(IFF_VNET_HDR) && defined(TUNGETFEATURES) && defined(TUNGETIFF)
unsigned int features;
struct ifreq dummy;
if (ioctl(tapfd, TUNGETFEATURES, &features) != 0) {
VIR_INFO("Not enabling IFF_VNET_HDR; "
"TUNGETFEATURES ioctl() not implemented");
return 0;
}
if (!(features & IFF_VNET_HDR)) {
VIR_INFO("Not enabling IFF_VNET_HDR; "
"TUNGETFEATURES ioctl() reports no IFF_VNET_HDR");
return 0;
}
/* The kernel will always return -1 at this point.
* If TUNGETIFF is not implemented then errno == EBADFD.
*/
if (ioctl(tapfd, TUNGETIFF, &dummy) != -1 || errno != EBADFD) {
VIR_INFO("Not enabling IFF_VNET_HDR; "
"TUNGETIFF ioctl() not implemented");
return 0;
}
VIR_INFO("Enabling IFF_VNET_HDR");
return 1;
# else
(void) tapfd;
VIR_INFO("Not enabling IFF_VNET_HDR; disabled at build time");
return 0;
# endif
}
#endif
#ifdef TUNSETIFF
/**
* virNetDevTapCreate:
* @ifname: the interface name
* @tapfds: array of file descriptors return value for the new tap device
* @tapfdSize: number of file descriptors in @tapfd
* @flags: OR of virNetDevTapCreateFlags. Only one flag is recognized:
*
* VIR_NETDEV_TAP_CREATE_VNET_HDR
* - Enable IFF_VNET_HDR on the tap device
* VIR_NETDEV_TAP_CREATE_PERSIST
* - The device will persist after the file descriptor is closed
*
* Creates a tap interface. The caller must use virNetDevTapDelete to
* remove a persistent TAP device when it is no longer needed. In case
* @tapfdSize is greater than one, multiqueue extension is requested
* from kernel.
*
* Returns 0 in case of success or -1 on failure.
*/
int virNetDevTapCreate(char **ifname,
int *tapfd,
int tapfdSize,
unsigned int flags)
{
size_t i;
struct ifreq ifr;
int ret = -1;
int fd;
memset(&ifr, 0, sizeof(ifr));
for (i = 0; i < tapfdSize; i++) {
if ((fd = open("/dev/net/tun", O_RDWR)) < 0) {
virReportSystemError(errno, "%s",
_("Unable to open /dev/net/tun, is tun module loaded?"));
goto cleanup;
}
memset(&ifr, 0, sizeof(ifr));
ifr.ifr_flags = IFF_TAP | IFF_NO_PI;
/* If tapfdSize is greater than one, request multiqueue */
if (tapfdSize > 1) {
# ifdef IFF_MULTI_QUEUE
ifr.ifr_flags |= IFF_MULTI_QUEUE;
# else
virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
_("Multiqueue devices are not supported on this system"));
goto cleanup;
# endif
}
# ifdef IFF_VNET_HDR
if ((flags & VIR_NETDEV_TAP_CREATE_VNET_HDR) &&
virNetDevProbeVnetHdr(fd))
ifr.ifr_flags |= IFF_VNET_HDR;
# endif
if (virStrcpyStatic(ifr.ifr_name, *ifname) == NULL) {
virReportSystemError(ERANGE,
_("Network interface name '%s' is too long"),
*ifname);
goto cleanup;
}
if (ioctl(fd, TUNSETIFF, &ifr) < 0) {
virReportSystemError(errno,
_("Unable to create tap device %s"),
NULLSTR(*ifname));
goto cleanup;
}
if (i == 0) {
/* In case we are looping more than once, set other
* TAPs to have the same name */
VIR_FREE(*ifname);
if (VIR_STRDUP(*ifname, ifr.ifr_name) < 0)
goto cleanup;
}
if ((flags & VIR_NETDEV_TAP_CREATE_PERSIST) &&
(errno = ioctl(fd, TUNSETPERSIST, 1))) {
virReportSystemError(errno,
_("Unable to set tap device %s to persistent"),
NULLSTR(*ifname));
goto cleanup;
}
tapfd[i] = fd;
}
ret = 0;
cleanup:
if (ret < 0) {
VIR_FORCE_CLOSE(fd);
while (i--)
VIR_FORCE_CLOSE(tapfd[i]);
}
return ret;
}
int virNetDevTapDelete(const char *ifname)
{
struct ifreq try;
int fd;
int ret = -1;
if ((fd = open("/dev/net/tun", O_RDWR)) < 0) {
virReportSystemError(errno, "%s",
_("Unable to open /dev/net/tun, is tun module loaded?"));
return -1;
}
memset(&try, 0, sizeof(struct ifreq));
try.ifr_flags = IFF_TAP|IFF_NO_PI;
if (virStrcpyStatic(try.ifr_name, ifname) == NULL) {
virReportSystemError(ERANGE,
_("Network interface name '%s' is too long"),
ifname);
goto cleanup;
}
if (ioctl(fd, TUNSETIFF, &try) < 0) {
virReportSystemError(errno, "%s",
_("Unable to associate TAP device"));
goto cleanup;
}
if (ioctl(fd, TUNSETPERSIST, 0) < 0) {
virReportSystemError(errno, "%s",
_("Unable to make TAP device non-persistent"));
goto cleanup;
}
ret = 0;
cleanup:
VIR_FORCE_CLOSE(fd);
return ret;
}
#elif defined(SIOCIFCREATE2) && defined(SIOCIFDESTROY) && defined(IF_MAXUNIT)
int virNetDevTapCreate(char **ifname,
int *tapfd,
int tapfdSize,
unsigned int flags ATTRIBUTE_UNUSED)
{
int s;
struct ifreq ifr;
int ret = -1;
char *newifname = NULL;
if (tapfdSize > 1) {
virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
_("Multiqueue devices are not supported on this system"));
goto cleanup;
}
/* As FreeBSD determines interface type by name,
* we have to create 'tap' interface first and
* then rename it to 'vnet'
*/
if ((s = virNetDevSetupControl("tap", &ifr)) < 0)
return -1;
if (ioctl(s, SIOCIFCREATE2, &ifr) < 0) {
virReportSystemError(errno, "%s",
_("Unable to create tap device"));
goto cleanup;
}
/* In case we were given exact interface name (e.g. 'vnetN'),
* we just rename to it. If we have format string like
* 'vnet%d', we need to find the first available name that
* matches this pattern
*/
if (strstr(*ifname, "%d") != NULL) {
size_t i;
for (i = 0; i <= IF_MAXUNIT; i++) {
char *newname;
if (virAsprintf(&newname, *ifname, i) < 0)
goto cleanup;
if (virNetDevExists(newname) == 0) {
newifname = newname;
break;
}
VIR_FREE(newname);
}
if (newifname) {
VIR_FREE(*ifname);
*ifname = newifname;
} else {
virReportError(VIR_ERR_INTERNAL_ERROR,
_("Failed to generate new name for interface %s"),
ifr.ifr_name);
goto cleanup;
}
}
if (tapfd) {
char *dev_path = NULL;
if (virAsprintf(&dev_path, "/dev/%s", ifr.ifr_name) < 0)
goto cleanup;
if ((*tapfd = open(dev_path, O_RDWR)) < 0) {
virReportSystemError(errno,
_("Unable to open %s"),
dev_path);
VIR_FREE(dev_path);
goto cleanup;
}
VIR_FREE(dev_path);
}
if (virNetDevSetName(ifr.ifr_name, *ifname) == -1) {
goto cleanup;
}
ret = 0;
cleanup:
VIR_FORCE_CLOSE(s);
return ret;
}
int virNetDevTapDelete(const char *ifname)
{
int s;
struct ifreq ifr;
int ret = -1;
if ((s = virNetDevSetupControl(ifname, &ifr)) < 0)
return -1;
if (ioctl(s, SIOCIFDESTROY, &ifr) < 0) {
virReportSystemError(errno,
_("Unable to remove tap device %s"),
ifname);
goto cleanup;
}
ret = 0;
cleanup:
VIR_FORCE_CLOSE(s);
return ret;
}
#else
int virNetDevTapCreate(char **ifname ATTRIBUTE_UNUSED,
int *tapfd ATTRIBUTE_UNUSED,
int tapfdSize ATTRIBUTE_UNUSED,
unsigned int flags ATTRIBUTE_UNUSED)
{
virReportSystemError(ENOSYS, "%s",
_("Unable to create TAP devices on this platform"));
return -1;
}
int virNetDevTapDelete(const char *ifname ATTRIBUTE_UNUSED)
{
virReportSystemError(ENOSYS, "%s",
_("Unable to delete TAP devices on this platform"));
return -1;
}
#endif
/**
* virNetDevTapCreateInBridgePort:
* @brname: the bridge name
* @ifname: the interface name (or name template)
* @macaddr: desired MAC address
* @tapfd: array of file descriptor return value for the new tap device
* @tapfdSize: number of file descriptors in @tapfd
* @virtPortProfile: bridge/port specific configuration
* @flags: OR of virNetDevTapCreateFlags:
* VIR_NETDEV_TAP_CREATE_IFUP
* - Bring the interface up
* VIR_NETDEV_TAP_CREATE_VNET_HDR
* - Enable IFF_VNET_HDR on the tap device
* VIR_NETDEV_TAP_CREATE_USE_MAC_FOR_BRIDGE
* - Set this interface's MAC as the bridge's MAC address
* VIR_NETDEV_TAP_CREATE_PERSIST
* - The device will persist after the file descriptor is closed
*
* This function creates a new tap device on a bridge. @ifname can be either
* a fixed name or a name template with '%d' for dynamic name allocation.
* in either case the final name for the bridge will be stored in @ifname.
* If the @tapfd parameter is supplied, the open tap device file descriptor
* will be returned, otherwise the TAP device will be closed. The caller must
* use virNetDevTapDelete to remove a persistent TAP device when it is no
* longer needed.
*
* Returns 0 in case of success or -1 on failure
*/
int virNetDevTapCreateInBridgePort(const char *brname,
char **ifname,
const virMacAddr *macaddr,
const unsigned char *vmuuid,
int *tapfd,
int tapfdSize,
virNetDevVPortProfilePtr virtPortProfile,
virNetDevVlanPtr virtVlan,
unsigned int flags)
{
virMacAddr tapmac;
char macaddrstr[VIR_MAC_STRING_BUFLEN];
size_t i;
if (virNetDevTapCreate(ifname, tapfd, tapfdSize, flags) < 0)
return -1;
/* We need to set the interface MAC before adding it
* to the bridge, because the bridge assumes the lowest
* MAC of all enslaved interfaces & we don't want it
* seeing the kernel allocate random MAC for the TAP
* device before we set our static MAC.
*/
virMacAddrSet(&tapmac, macaddr);
if (!(flags & VIR_NETDEV_TAP_CREATE_USE_MAC_FOR_BRIDGE)) {
if (macaddr->addr[0] == 0xFE) {
/* For normal use, the tap device's MAC address cannot
* match the MAC address used by the guest. This results
* in "received packet on vnetX with own address as source
* address" error logs from the kernel.
*/
virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
_("Unable to use MAC address starting with "
"reserved value 0xFE - '%s' - "),
virMacAddrFormat(macaddr, macaddrstr));
goto error;
}
tapmac.addr[0] = 0xFE; /* Discourage bridge from using TAP dev MAC */
}
if (virNetDevSetMAC(*ifname, &tapmac) < 0)
goto error;
/* We need to set the interface MTU before adding it
* to the bridge, because the bridge will have its
* MTU adjusted automatically when we add the new interface.
*/
if (virNetDevSetMTUFromDevice(*ifname, brname) < 0)
goto error;
if (virtPortProfile) {
if (virNetDevOpenvswitchAddPort(brname, *ifname, macaddr, vmuuid,
virtPortProfile, virtVlan) < 0) {
goto error;
}
} else {
if (virNetDevBridgeAddPort(brname, *ifname) < 0)
goto error;
}
if (virNetDevSetOnline(*ifname, !!(flags & VIR_NETDEV_TAP_CREATE_IFUP)) < 0)
goto error;
return 0;
error:
for (i = 0; i < tapfdSize && tapfd[i] >= 0; i++)
VIR_FORCE_CLOSE(tapfd[i]);
return -1;
}