libvirt/src/util/virlease.c
Nehal J Wani 1dcbb27402 Don't drop expired lease while reading custom leases file
Libvirt, on its own, shouldn't decide whether an expired lease should
stay in the custom leases database or not. It should rather rely on
the 'DEL' event from dnsmasq.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
2016-10-05 08:33:59 +02:00

298 lines
9.8 KiB
C

/*
* virlease.c: Leases file handling
*
* Copyright (C) 2014 Red Hat, Inc.
* Copyright (C) 2014 Nehal J Wani
*
* 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/>.
*
*/
#include <config.h>
#include "virlease.h"
#include <time.h>
#include "virfile.h"
#include "virstring.h"
#include "virerror.h"
#include "viralloc.h"
#include "virutil.h"
#define VIR_FROM_THIS VIR_FROM_NETWORK
/**
* VIR_NETWORK_DHCP_LEASE_FILE_SIZE_MAX:
*
* Macro providing the upper limit on the size of leases file
*/
#define VIR_NETWORK_DHCP_LEASE_FILE_SIZE_MAX (32 * 1024 * 1024)
/*
* Use this when passing possibly-NULL strings to printf-a-likes.
* Required for unknown parameters during init call.
*/
#define EMPTY_STR(s) ((s) ? (s) : "*")
int
virLeaseReadCustomLeaseFile(virJSONValuePtr leases_array_new,
const char *custom_lease_file,
const char *ip_to_delete,
char **server_duid)
{
char *lease_entries = NULL;
virJSONValuePtr leases_array = NULL;
long long expirytime;
int custom_lease_file_len = 0;
virJSONValuePtr lease_tmp = NULL;
const char *ip_tmp = NULL;
const char *server_duid_tmp = NULL;
size_t i;
int ret = -1;
/* Read entire contents */
if ((custom_lease_file_len = virFileReadAll(custom_lease_file,
VIR_NETWORK_DHCP_LEASE_FILE_SIZE_MAX,
&lease_entries)) < 0) {
goto cleanup;
}
/* Check for previous leases */
if (custom_lease_file_len == 0) {
ret = 0;
goto cleanup;
}
if (!(leases_array = virJSONValueFromString(lease_entries))) {
virReportError(VIR_ERR_INTERNAL_ERROR,
_("invalid json in file: %s, rewriting it"),
custom_lease_file);
ret = 0;
goto cleanup;
}
if (!virJSONValueIsArray(leases_array)) {
virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
_("couldn't fetch array of leases"));
goto cleanup;
}
i = 0;
while (i < virJSONValueArraySize(leases_array)) {
if (!(lease_tmp = virJSONValueArrayGet(leases_array, i))) {
virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
_("failed to parse json"));
goto cleanup;
}
if (!(ip_tmp = virJSONValueObjectGetString(lease_tmp, "ip-address")) ||
(virJSONValueObjectGetNumberLong(lease_tmp, "expiry-time", &expirytime) < 0)) {
virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
_("failed to parse json"));
goto cleanup;
}
/* Check whether lease has to be included or not */
if (ip_to_delete && STREQ(ip_tmp, ip_to_delete)) {
i++;
continue;
}
if (server_duid && strchr(ip_tmp, ':')) {
/* This is an ipv6 lease */
if ((server_duid_tmp
= virJSONValueObjectGetString(lease_tmp, "server-duid"))) {
if (!*server_duid && VIR_STRDUP(*server_duid, server_duid_tmp) < 0) {
/* Control reaches here when the 'action' is not for an
* ipv6 lease or, for some weird reason the env var
* DNSMASQ_SERVER_DUID wasn't set*/
goto cleanup;
}
} else {
/* Inject server-duid into those ipv6 leases which
* didn't have it previously, for example, those
* created by leaseshelper from libvirt 1.2.6 */
if (virJSONValueObjectAppendString(lease_tmp, "server-duid", *server_duid) < 0)
goto cleanup;
}
}
/* Move old lease to new array */
if (virJSONValueArrayAppend(leases_array_new, lease_tmp) < 0) {
virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
_("failed to create json"));
goto cleanup;
}
ignore_value(virJSONValueArraySteal(leases_array, i));
}
ret = 0;
cleanup:
virJSONValueFree(leases_array);
VIR_FREE(lease_entries);
return ret;
}
int
virLeasePrintLeases(virJSONValuePtr leases_array_new,
const char *server_duid)
{
virJSONValuePtr lease_tmp = NULL;
const char *ip_tmp = NULL;
long long expirytime = 0;
int ret = -1;
size_t i;
/* Man page of dnsmasq says: the script (helper program, in our case)
* should write the saved state of the lease database, in dnsmasq
* leasefile format, to stdout and exit with zero exit code, when
* called with argument init. Format:
* $expirytime $mac $ip $hostname $clientid # For all ipv4 leases
* duid $server-duid # If DHCPv6 is present
* $expirytime $iaid $ip $hostname $clientduid # For all ipv6 leases */
/* Traversing the ipv4 leases */
for (i = 0; i < virJSONValueArraySize(leases_array_new); i++) {
lease_tmp = virJSONValueArrayGet(leases_array_new, i);
if (!(ip_tmp = virJSONValueObjectGetString(lease_tmp, "ip-address"))) {
virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
_("failed to parse json"));
goto cleanup;
}
if (!strchr(ip_tmp, ':')) {
if (virJSONValueObjectGetNumberLong(lease_tmp, "expiry-time",
&expirytime) < 0)
continue;
printf("%lld %s %s %s %s\n",
expirytime,
virJSONValueObjectGetString(lease_tmp, "mac-address"),
virJSONValueObjectGetString(lease_tmp, "ip-address"),
EMPTY_STR(virJSONValueObjectGetString(lease_tmp, "hostname")),
EMPTY_STR(virJSONValueObjectGetString(lease_tmp, "client-id")));
}
}
/* Traversing the ipv6 leases */
if (server_duid) {
printf("duid %s\n", server_duid);
for (i = 0; i < virJSONValueArraySize(leases_array_new); i++) {
lease_tmp = virJSONValueArrayGet(leases_array_new, i);
if (!(ip_tmp = virJSONValueObjectGetString(lease_tmp, "ip-address"))) {
virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
_("failed to parse json"));
goto cleanup;
}
if (strchr(ip_tmp, ':')) {
if (virJSONValueObjectGetNumberLong(lease_tmp, "expiry-time",
&expirytime) < 0)
continue;
printf("%lld %s %s %s %s\n",
expirytime,
virJSONValueObjectGetString(lease_tmp, "iaid"),
virJSONValueObjectGetString(lease_tmp, "ip-address"),
EMPTY_STR(virJSONValueObjectGetString(lease_tmp, "hostname")),
EMPTY_STR(virJSONValueObjectGetString(lease_tmp, "client-id")));
}
}
}
ret = 0;
cleanup:
return ret;
}
int
virLeaseNew(virJSONValuePtr *lease_ret,
const char *mac,
const char *clientid,
const char *ip,
const char *hostname,
const char *iaid,
const char *server_duid)
{
virJSONValuePtr lease_new = NULL;
const char *exptime_tmp = virGetEnvAllowSUID("DNSMASQ_LEASE_EXPIRES");
long long expirytime = 0;
char *exptime = NULL;
int ret = -1;
/* In case hostname is still unknown, use the last known one */
if (!hostname)
hostname = virGetEnvAllowSUID("DNSMASQ_OLD_HOSTNAME");
if (!mac) {
ret = 0;
goto cleanup;
}
if (exptime_tmp) {
if (VIR_STRDUP(exptime, exptime_tmp) < 0)
goto cleanup;
/* Removed extraneous trailing space in DNSMASQ_LEASE_EXPIRES
* (dnsmasq < 2.52) */
if (exptime[strlen(exptime) - 1] == ' ')
exptime[strlen(exptime) - 1] = '\0';
}
if (!exptime ||
virStrToLong_ll(exptime, NULL, 10, &expirytime) < 0) {
virReportError(VIR_ERR_INTERNAL_ERROR,
_("Unable to convert lease expiry time to long long: %s"),
NULLSTR(exptime));
goto cleanup;
}
/* Create new lease */
if (!(lease_new = virJSONValueNewObject())) {
virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
_("failed to create json"));
goto cleanup;
}
if (iaid && virJSONValueObjectAppendString(lease_new, "iaid", iaid) < 0)
goto cleanup;
if (ip && virJSONValueObjectAppendString(lease_new, "ip-address", ip) < 0)
goto cleanup;
if (mac && virJSONValueObjectAppendString(lease_new, "mac-address", mac) < 0)
goto cleanup;
if (hostname && virJSONValueObjectAppendString(lease_new, "hostname", hostname) < 0)
goto cleanup;
if (clientid && virJSONValueObjectAppendString(lease_new, "client-id", clientid) < 0)
goto cleanup;
if (server_duid && virJSONValueObjectAppendString(lease_new, "server-duid", server_duid) < 0)
goto cleanup;
if (expirytime && virJSONValueObjectAppendNumberLong(lease_new, "expiry-time", expirytime) < 0)
goto cleanup;
ret = 0;
*lease_ret = lease_new;
lease_new = NULL;
cleanup:
VIR_FREE(exptime);
virJSONValueFree(lease_new);
return ret;
}