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/*
* 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
/* 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;
}
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