libvirt/src/util/bridge.c

784 lines
18 KiB
C
Raw Normal View History

/*
* Copyright (C) 2007, 2009 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, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* Authors:
* Mark McLoughlin <markmc@redhat.com>
*/
#include <config.h>
#if defined(WITH_BRIDGE)
# include "bridge.h"
# include "files.h"
# include <stdlib.h>
# include <stdio.h>
# include <string.h>
# include <unistd.h>
# include <fcntl.h>
# include <errno.h>
# include <arpa/inet.h>
# include <sys/types.h>
# include <sys/socket.h>
# include <sys/ioctl.h>
# include <paths.h>
# include <sys/wait.h>
# include <linux/param.h> /* HZ */
# include <linux/sockios.h> /* SIOCBRADDBR etc. */
# include <linux/if_bridge.h> /* SYSFS_BRIDGE_ATTR */
# include <linux/if_tun.h> /* IFF_TUN, IFF_NO_PI */
# include <net/if_arp.h> /* ARPHRD_ETHER */
# include "internal.h"
# include "memory.h"
# include "util.h"
# include "logging.h"
# include "network.h"
# define JIFFIES_TO_MS(j) (((j)*1000)/HZ)
# define MS_TO_JIFFIES(ms) (((ms)*HZ)/1000)
struct _brControl {
int fd;
};
/**
* brInit:
* @ctlp: pointer to bridge control return value
*
* Initialize a new bridge layer. In case of success
* @ctlp will contain a pointer to the new bridge structure.
*
* Returns 0 in case of success, an error code otherwise.
*/
int
brInit(brControl **ctlp)
{
int fd;
int flags;
if (!ctlp || *ctlp)
return EINVAL;
fd = socket(AF_INET, SOCK_STREAM, 0);
if (fd < 0)
return errno;
if ((flags = fcntl(fd, F_GETFD)) < 0 ||
fcntl(fd, F_SETFD, flags | FD_CLOEXEC) < 0) {
int err = errno;
VIR_FORCE_CLOSE(fd);
return err;
}
if (VIR_ALLOC(*ctlp) < 0) {
VIR_FORCE_CLOSE(fd);
return ENOMEM;
}
(*ctlp)->fd = fd;
return 0;
}
/**
* brShutdown:
* @ctl: pointer to a bridge control
*
* Shutdown the bridge layer and deallocate the associated structures
*/
void
brShutdown(brControl *ctl)
{
if (!ctl)
return;
VIR_FORCE_CLOSE(ctl->fd);
VIR_FREE(ctl);
}
/**
* brAddBridge:
* @ctl: bridge control pointer
* @name: the bridge name
*
* This function register a new bridge
*
* Returns 0 in case of success or an errno code in case of failure.
*/
# ifdef SIOCBRADDBR
int
brAddBridge(brControl *ctl,
const char *name)
{
if (!ctl || !ctl->fd || !name)
return EINVAL;
if (ioctl(ctl->fd, SIOCBRADDBR, name) == 0)
return 0;
return errno;
}
# else
int brAddBridge (brControl *ctl ATTRIBUTE_UNUSED,
const char *name ATTRIBUTE_UNUSED)
{
return EINVAL;
}
# endif
# ifdef SIOCBRDELBR
int
brHasBridge(brControl *ctl,
const char *name)
{
struct ifreq ifr;
if (!ctl || !name) {
errno = EINVAL;
return -1;
}
memset(&ifr, 0, sizeof(struct ifreq));
if (virStrcpyStatic(ifr.ifr_name, name) == NULL) {
errno = EINVAL;
return -1;
}
if (ioctl(ctl->fd, SIOCGIFFLAGS, &ifr))
return -1;
return 0;
}
# else
int
brHasBridge(brControl *ctl ATTRIBUTE_UNUSED,
const char *name ATTRIBUTE_UNUSED)
{
return EINVAL;
}
# endif
/**
* brDeleteBridge:
* @ctl: bridge control pointer
* @name: the bridge name
*
* Remove a bridge from the layer.
*
* Returns 0 in case of success or an errno code in case of failure.
*/
# ifdef SIOCBRDELBR
int
brDeleteBridge(brControl *ctl,
const char *name)
{
if (!ctl || !ctl->fd || !name)
return EINVAL;
return ioctl(ctl->fd, SIOCBRDELBR, name) == 0 ? 0 : errno;
}
# else
int
brDeleteBridge(brControl *ctl ATTRIBUTE_UNUSED,
const char *name ATTRIBUTE_UNUSED)
{
return EINVAL;
}
# endif
# if defined(SIOCBRADDIF) && defined(SIOCBRDELIF)
static int
brAddDelInterface(brControl *ctl,
int cmd,
const char *bridge,
const char *iface)
{
struct ifreq ifr;
if (!ctl || !ctl->fd || !bridge || !iface)
return EINVAL;
memset(&ifr, 0, sizeof(struct ifreq));
if (virStrcpyStatic(ifr.ifr_name, bridge) == NULL)
return EINVAL;
if (!(ifr.ifr_ifindex = if_nametoindex(iface)))
return ENODEV;
return ioctl(ctl->fd, cmd, &ifr) == 0 ? 0 : errno;
}
# endif
/**
* brAddInterface:
* @ctl: bridge control pointer
* @bridge: the bridge name
* @iface: the network interface name
*
* Adds an interface to a bridge
*
* Returns 0 in case of success or an errno code in case of failure.
*/
# ifdef SIOCBRADDIF
int
brAddInterface(brControl *ctl,
const char *bridge,
const char *iface)
{
return brAddDelInterface(ctl, SIOCBRADDIF, bridge, iface);
}
# else
int
brAddInterface(brControl *ctl ATTRIBUTE_UNUSED,
const char *bridge ATTRIBUTE_UNUSED,
const char *iface ATTRIBUTE_UNUSED)
{
return EINVAL;
}
# endif
/**
* brDeleteInterface:
* @ctl: bridge control pointer
* @bridge: the bridge name
* @iface: the network interface name
*
* Removes an interface from a bridge
*
* Returns 0 in case of success or an errno code in case of failure.
*/
# ifdef SIOCBRDELIF
int
brDeleteInterface(brControl *ctl,
const char *bridge,
const char *iface)
{
return brAddDelInterface(ctl, SIOCBRDELIF, bridge, iface);
}
# else
int
brDeleteInterface(brControl *ctl ATTRIBUTE_UNUSED,
const char *bridge ATTRIBUTE_UNUSED,
const char *iface ATTRIBUTE_UNUSED)
{
return EINVAL;
}
# endif
2007-03-13 22:43:22 +00:00
/**
* ifSetInterfaceMac:
* @ctl: bridge control pointer
* @ifname: interface name to set MTU for
* @macaddr: MAC address (VIR_MAC_BUFLEN in size)
*
* This function sets the @macaddr for a given interface @ifname. This
* gets rid of the kernel's automatically assigned random MAC.
*
* Returns 0 in case of success or an errno code in case of failure.
*/
static int ifSetInterfaceMac(brControl *ctl, const char *ifname,
const unsigned char *macaddr)
{
struct ifreq ifr;
if (!ctl || !ifname)
return EINVAL;
memset(&ifr, 0, sizeof(struct ifreq));
if (virStrcpyStatic(ifr.ifr_name, ifname) == NULL)
return EINVAL;
/* To fill ifr.ifr_hdaddr.sa_family field */
if (ioctl(ctl->fd, SIOCGIFHWADDR, &ifr) != 0)
return errno;
memcpy(ifr.ifr_hwaddr.sa_data, macaddr, VIR_MAC_BUFLEN);
return ioctl(ctl->fd, SIOCSIFHWADDR, &ifr) == 0 ? 0 : errno;
}
/**
* ifGetMtu
* @ctl: bridge control pointer
* @ifname: interface name get MTU for
*
* This function gets the @mtu value set for a given interface @ifname.
*
* Returns the MTU value in case of success.
* On error, returns -1 and sets errno accordingly
*/
static int ifGetMtu(brControl *ctl, const char *ifname)
{
struct ifreq ifr;
if (!ctl || !ifname) {
errno = EINVAL;
return -1;
}
memset(&ifr, 0, sizeof(struct ifreq));
if (virStrcpyStatic(ifr.ifr_name, ifname) == NULL) {
errno = EINVAL;
return -1;
}
if (ioctl(ctl->fd, SIOCGIFMTU, &ifr))
return -1;
return ifr.ifr_mtu;
}
/**
* ifSetMtu:
* @ctl: bridge control pointer
* @ifname: interface name to set MTU for
* @mtu: MTU value
*
* This function sets the @mtu for a given interface @ifname. Typically
* used on a tap device to set up for Jumbo Frames.
*
* Returns 0 in case of success or an errno code in case of failure.
*/
static int ifSetMtu(brControl *ctl, const char *ifname, int mtu)
{
struct ifreq ifr;
if (!ctl || !ifname)
return EINVAL;
memset(&ifr, 0, sizeof(struct ifreq));
if (virStrcpyStatic(ifr.ifr_name, ifname) == NULL)
return EINVAL;
ifr.ifr_mtu = mtu;
return ioctl(ctl->fd, SIOCSIFMTU, &ifr) == 0 ? 0 : errno;
}
/**
* brSetInterfaceMtu
* @ctl: bridge control pointer
* @bridge: name of the bridge interface
* @ifname: name of the interface whose MTU we want to set
*
* Sets the interface mtu to the same MTU of the bridge
*
* Returns 0 in case of success or an errno code in case of failure.
*/
static int brSetInterfaceMtu(brControl *ctl,
const char *bridge,
const char *ifname)
{
int mtu = ifGetMtu(ctl, bridge);
if (mtu < 0)
return errno;
return ifSetMtu(ctl, ifname, mtu);
}
/**
* brProbeVnetHdr:
* @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 0 in case of success or an errno code in case of failure.
*/
# ifdef IFF_VNET_HDR
static int
brProbeVnetHdr(int tapfd)
{
# if defined(IFF_VNET_HDR) && defined(TUNGETFEATURES) && defined(TUNGETIFF)
unsigned int features;
struct ifreq dummy;
if (ioctl(tapfd, TUNGETFEATURES, &features) != 0) {
VIR_INFO0(_("Not enabling IFF_VNET_HDR; "
"TUNGETFEATURES ioctl() not implemented"));
return 0;
}
if (!(features & IFF_VNET_HDR)) {
VIR_INFO0(_("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_INFO0(_("Not enabling IFF_VNET_HDR; "
"TUNGETIFF ioctl() not implemented"));
return 0;
}
VIR_INFO0(_("Enabling IFF_VNET_HDR"));
return 1;
# else
(void) tapfd;
VIR_INFO0(_("Not enabling IFF_VNET_HDR; disabled at build time"));
return 0;
# endif
}
# endif
/**
* brAddTap:
* @ctl: bridge control pointer
* @bridge: the bridge name
* @ifname: the interface name (or name template)
* @macaddr: desired MAC address (VIR_MAC_BUFLEN long)
* @vnet_hdr: whether to try enabling IFF_VNET_HDR
* @tapfd: file descriptor return value for the new tap device
*
* 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.
2009-06-03 11:13:33 +00:00
* 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 made
* persistent and closed. The caller must use brDeleteTap to remove
* a persistent TAP devices when it is no longer needed.
*
* Returns 0 in case of success or an errno code in case of failure.
*/
int
brAddTap(brControl *ctl,
const char *bridge,
char **ifname,
const unsigned char *macaddr,
int vnet_hdr,
int *tapfd)
{
int fd;
struct ifreq ifr;
2009-06-03 11:13:33 +00:00
if (!ctl || !ctl->fd || !bridge || !ifname)
return EINVAL;
if ((fd = open("/dev/net/tun", O_RDWR)) < 0)
return errno;
memset(&ifr, 0, sizeof(ifr));
ifr.ifr_flags = IFF_TAP|IFF_NO_PI;
# ifdef IFF_VNET_HDR
if (vnet_hdr && brProbeVnetHdr(fd))
ifr.ifr_flags |= IFF_VNET_HDR;
# else
(void) vnet_hdr;
# endif
if (virStrcpyStatic(ifr.ifr_name, *ifname) == NULL) {
errno = EINVAL;
goto error;
}
if (ioctl(fd, TUNSETIFF, &ifr) < 0)
goto error;
/* 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.
*/
if ((errno = ifSetInterfaceMac(ctl, ifr.ifr_name, macaddr)))
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 ((errno = brSetInterfaceMtu(ctl, bridge, ifr.ifr_name)))
goto error;
if ((errno = brAddInterface(ctl, bridge, ifr.ifr_name)))
goto error;
if ((errno = brSetInterfaceUp(ctl, ifr.ifr_name, 1)))
goto error;
if (!tapfd &&
(errno = ioctl(fd, TUNSETPERSIST, 1)))
goto error;
VIR_FREE(*ifname);
if (!(*ifname = strdup(ifr.ifr_name)))
goto error;
if (tapfd)
*tapfd = fd;
else
VIR_FORCE_CLOSE(fd);
return 0;
error:
VIR_FORCE_CLOSE(fd);
return errno;
}
2009-06-03 11:13:33 +00:00
int brDeleteTap(brControl *ctl,
const char *ifname)
{
struct ifreq try;
int fd;
if (!ctl || !ctl->fd || !ifname)
return EINVAL;
if ((fd = open("/dev/net/tun", O_RDWR)) < 0)
return errno;
memset(&try, 0, sizeof(struct ifreq));
try.ifr_flags = IFF_TAP|IFF_NO_PI;
if (virStrcpyStatic(try.ifr_name, ifname) == NULL) {
2009-06-03 11:13:33 +00:00
errno = EINVAL;
goto error;
}
if (ioctl(fd, TUNSETIFF, &try) == 0) {
if ((errno = ioctl(fd, TUNSETPERSIST, 0)))
goto error;
}
error:
VIR_FORCE_CLOSE(fd);
2009-06-03 11:13:33 +00:00
return errno;
}
/**
* brSetInterfaceUp:
* @ctl: bridge control pointer
* @ifname: the interface name
* @up: 1 for up, 0 for down
*
* Function to control if an interface is activated (up, 1) or not (down, 0)
*
* Returns 0 in case of success or an errno code in case of failure.
*/
int
brSetInterfaceUp(brControl *ctl,
const char *ifname,
int up)
{
struct ifreq ifr;
int flags;
if (!ctl || !ifname)
return EINVAL;
memset(&ifr, 0, sizeof(struct ifreq));
if (virStrcpyStatic(ifr.ifr_name, ifname) == NULL)
return EINVAL;
if (ioctl(ctl->fd, SIOCGIFFLAGS, &ifr) < 0)
return errno;
flags = up ? (ifr.ifr_flags | IFF_UP) : (ifr.ifr_flags & ~IFF_UP);
if (ifr.ifr_flags != flags) {
ifr.ifr_flags = flags;
if (ioctl(ctl->fd, SIOCSIFFLAGS, &ifr) < 0)
return errno;
}
return 0;
}
/**
* brGetInterfaceUp:
* @ctl: bridge control pointer
* @ifname: the interface name
* @up: where to store the status
*
* Function to query if an interface is activated (1) or not (0)
*
* Returns 0 in case of success or an errno code in case of failure.
*/
int
brGetInterfaceUp(brControl *ctl,
const char *ifname,
int *up)
{
struct ifreq ifr;
if (!ctl || !ifname || !up)
return EINVAL;
memset(&ifr, 0, sizeof(struct ifreq));
if (virStrcpyStatic(ifr.ifr_name, ifname) == NULL)
return EINVAL;
if (ioctl(ctl->fd, SIOCGIFFLAGS, &ifr) < 0)
return errno;
*up = (ifr.ifr_flags & IFF_UP) ? 1 : 0;
return 0;
}
static int
brSetInetAddr(brControl *ctl,
const char *ifname,
int cmd,
virSocketAddr *addr)
{
struct ifreq ifr;
if (!ctl || !ctl->fd || !ifname || !addr)
return EINVAL;
memset(&ifr, 0, sizeof(struct ifreq));
if (virStrcpyStatic(ifr.ifr_name, ifname) == NULL)
return EINVAL;
if (!VIR_SOCKET_IS_FAMILY(addr, AF_INET))
return EINVAL;
ifr.ifr_addr = addr->data.sa;
if (ioctl(ctl->fd, cmd, &ifr) < 0)
return errno;
return 0;
}
/**
* brSetInetAddress:
* @ctl: bridge control pointer
* @ifname: the interface name
* @addr: the string representation of the IP address
*
* Function to bind the interface to an IP address, it should handle
* IPV4 and IPv6. The string for addr would be of the form
* "ddd.ddd.ddd.ddd" assuming the common IPv4 format.
*
* Returns 0 in case of success or an errno code in case of failure.
*/
int
brSetInetAddress(brControl *ctl,
const char *ifname,
virSocketAddr *addr)
{
return brSetInetAddr(ctl, ifname, SIOCSIFADDR, addr);
}
/**
* brSetInetNetmask:
* @ctl: bridge control pointer
* @ifname: the interface name
* @addr: the string representation of the netmask
*
* Function to set the netmask of an interface, it should handle
* IPV4 and IPv6 forms. The string for addr would be of the form
* "ddd.ddd.ddd.ddd" assuming the common IPv4 format.
*
* Returns 0 in case of success or an errno code in case of failure.
*/
int
brSetInetNetmask(brControl *ctl,
const char *ifname,
virSocketAddr *addr)
{
return brSetInetAddr(ctl, ifname, SIOCSIFNETMASK, addr);
}
/**
* brSetForwardDelay:
* @ctl: bridge control pointer
* @bridge: the bridge name
* @delay: delay in seconds
*
* Set the bridge forward delay
*
* Returns 0 in case of success or -1 on failure
*/
int
brSetForwardDelay(brControl *ctl ATTRIBUTE_UNUSED,
const char *bridge,
int delay)
{
char delayStr[30];
const char *const progargv[] = {
BRCTL, "setfd", bridge, delayStr, NULL
};
snprintf(delayStr, sizeof(delayStr), "%d", delay);
if (virRun(progargv, NULL) < 0)
return -1;
return 0;
}
/**
* brSetEnableSTP:
* @ctl: bridge control pointer
* @bridge: the bridge name
* @enable: 1 to enable, 0 to disable
*
* Control whether the bridge participates in the spanning tree protocol,
* in general don't disable it without good reasons.
*
* Returns 0 in case of success or -1 on failure
*/
int
brSetEnableSTP(brControl *ctl ATTRIBUTE_UNUSED,
const char *bridge,
int enable)
{
const char *setting = enable ? "on" : "off";
const char *const progargv[] = {
BRCTL, "stp", bridge, setting, NULL
};
if (virRun(progargv, NULL) < 0)
return -1;
return 0;
}
#endif /* WITH_BRIDGE */