libvirt/src/util/virnetdevveth.c
Daniel P. Berrange 428cffb1e7 Move LXC veth.c code into shared utility APIs
Move the virNetDevSetName and virNetDevSetNamespace APIs out
of LXC's veth.c and into virnetdev.c.

Move the remaining content of the file to src/util/virnetdevveth.c

* src/lxc/veth.c: Rename to src/util/virnetdevveth.c
* src/lxc/veth.h: Rename to src/util/virnetdevveth.h
* src/util/virnetdev.c, src/util/virnetdev.h: Add
  virNetDevSetName and virNetDevSetNamespace
* src/lxc/lxc_container.c, src/lxc/lxc_controller.c,
  src/lxc/lxc_driver.c: Update include paths
2011-11-15 10:28:02 +00:00

190 lines
5.6 KiB
C

/*
* Copyright (C) 2010-2011 Red Hat, Inc.
* Copyright IBM Corp. 2008
*
* 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:
* David L. Leskovec <dlesko at linux.vnet.ibm.com>
* Daniel P. Berrange <berrange@redhat.com>
*/
#include <config.h>
#include <sys/wait.h>
#include "virnetdevveth.h"
#include "memory.h"
#include "logging.h"
#include "command.h"
#include "virterror_internal.h"
#define VIR_FROM_THIS VIR_FROM_NONE
#define virNetDevvError(code, ...) \
virReportErrorHelper(VIR_FROM_NONE, code, __FILE__, \
__FUNCTION__, __LINE__, __VA_ARGS__)
/* Functions */
/**
* virNetDevVethGetFreeName:
* @veth: pointer to store returned name for veth device
* @startDev: device number to start at (x in vethx)
*
* Looks in /sys/class/net/ to find the first available veth device
* name.
*
* Returns non-negative device number on success or -1 in case of error
*/
static int virNetDevVethGetFreeName(char **veth, int startDev)
{
int devNum = startDev-1;
char *path = NULL;
VIR_DEBUG("Find free from veth%d", startDev);
do {
VIR_FREE(path);
++devNum;
if (virAsprintf(&path, "/sys/class/net/veth%d/", devNum) < 0) {
virReportOOMError();
return -1;
}
VIR_DEBUG("Probe %s", path);
} while (virFileExists(path));
VIR_FREE(path);
if (virAsprintf(veth, "veth%d", devNum) < 0) {
virReportOOMError();
return -1;
}
return devNum;
}
/**
* virNetDevVethCreate:
* @veth1: pointer to name for parent end of veth pair
* @veth2: pointer to return name for container end of veth pair
*
* Creates a veth device pair using the ip command:
* ip link add veth1 type veth peer name veth2
* If veth1 points to NULL on entry, it will be a valid interface on
* return. veth2 should point to NULL on entry.
*
* NOTE: If veth1 and veth2 names are not specified, ip will auto assign
* names. There seems to be two problems here -
* 1) There doesn't seem to be a way to determine the names of the
* devices that it creates. They show up in ip link show and
* under /sys/class/net/ however there is no guarantee that they
* are the devices that this process just created.
* 2) Once one of the veth devices is moved to another namespace, it
* is no longer visible in the parent namespace. This seems to
* confuse the name assignment causing it to fail with File exists.
* Because of these issues, this function currently allocates names
* prior to using the ip command, and returns any allocated names
* to the caller.
*
* Returns 0 on success or -1 in case of error
*/
int virNetDevVethCreate(char** veth1, char** veth2)
{
int rc = -1;
const char *argv[] = {
"ip", "link", "add", NULL, "type", "veth", "peer", "name", NULL, NULL
};
int vethDev = 0;
bool veth1_alloc = false;
bool veth2_alloc = false;
VIR_DEBUG("Host: %s guest: %s", NULLSTR(*veth1), NULLSTR(*veth2));
if (*veth1 == NULL) {
if ((vethDev = virNetDevVethGetFreeName(veth1, vethDev)) < 0)
goto cleanup;
VIR_DEBUG("Assigned host: %s", *veth1);
veth1_alloc = true;
vethDev++;
}
argv[3] = *veth1;
while (*veth2 == NULL) {
if ((vethDev = virNetDevVethGetFreeName(veth2, vethDev)) < 0) {
if (veth1_alloc)
VIR_FREE(*veth1);
goto cleanup;
}
/* Just make sure they didn't accidentally get same name */
if (STREQ(*veth1, *veth2)) {
vethDev++;
VIR_FREE(*veth2);
continue;
}
VIR_DEBUG("Assigned guest: %s", *veth2);
veth2_alloc = true;
}
argv[8] = *veth2;
VIR_DEBUG("Create Host: %s guest: %s", *veth1, *veth2);
if (virRun(argv, NULL) < 0) {
if (veth1_alloc)
VIR_FREE(*veth1);
if (veth2_alloc)
VIR_FREE(*veth2);
goto cleanup;
}
rc = 0;
cleanup:
return rc;
}
/**
* virNetDevVethDelete:
* @veth: name for one end of veth pair
*
* This will delete both veth devices in a pair. Only one end needs to
* be specified. The ip command will identify and delete the other veth
* device as well.
* ip link del veth
*
* Returns 0 on success or -1 in case of error
*/
int virNetDevVethDelete(const char *veth)
{
int rc;
const char *argv[] = {"ip", "link", "del", veth, NULL};
int cmdResult = 0;
VIR_DEBUG("veth: %s", veth);
rc = virRun(argv, &cmdResult);
if (rc != 0 ||
(WIFEXITED(cmdResult) && WEXITSTATUS(cmdResult) != 0)) {
/*
* Prevent overwriting an error log which may be set
* where an actual failure occurs.
*/
VIR_DEBUG("Failed to delete '%s' (%d)",
veth, WEXITSTATUS(cmdResult));
rc = -1;
}
return rc;
}