--- /dev/null
+/*
+ * leaseshelper.c: Helper program to create custom leases file
+ *
+ * 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/>.
+ *
+ * Author: Nehal J Wani <nehaljw.kkd1@gmail.com>
+ *
+ * For IPv6 support, use dnsmasq >= 2.67
+ */
+
+#include <config.h>
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/stat.h>
+
+#include "virutil.h"
+#include "virthread.h"
+#include "virfile.h"
+#include "virpidfile.h"
+#include "virbuffer.h"
+#include "virstring.h"
+#include "virerror.h"
+#include "viralloc.h"
+#include "virjson.h"
+#include "configmake.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)
+
+static const char *program_name;
+
+/* Display version information. */
+static void
+helperVersion(const char *argv0)
+{
+ printf("%s (%s) %s\n", argv0, PACKAGE_NAME, PACKAGE_VERSION);
+}
+
+ATTRIBUTE_NORETURN static void
+usage(int status)
+{
+ if (status) {
+ fprintf(stderr, _("%s: try --help for more details\n"), program_name);
+ } else {
+ printf(_("Usage: %s add|old|del mac|clientid ip [hostname]\n"
+ "Designed for use with 'dnsmasq --dhcp-script'\n"
+ "Refer to man page of dnsmasq for more details'\n"),
+ program_name);
+ }
+ exit(status);
+}
+
+static int
+customLeaseRewriteFile(int fd, void *opaque)
+{
+ char **data = opaque;
+
+ if (safewrite(fd, *data, strlen(*data)) < 0)
+ return -1;
+
+ return 0;
+}
+
+/* Flags denoting actions for a lease */
+enum virLeaseActionFlags {
+ VIR_LEASE_ACTION_ADD, /* Create new lease */
+ VIR_LEASE_ACTION_OLD, /* Lease already exists, renew it */
+ VIR_LEASE_ACTION_DEL, /* Delete the lease */
+
+ VIR_LEASE_ACTION_LAST
+};
+
+VIR_ENUM_DECL(virLeaseAction);
+
+VIR_ENUM_IMPL(virLeaseAction, VIR_LEASE_ACTION_LAST,
+ "add", "old", "del");
+
+int
+main(int argc, char **argv)
+{
+ char *exptime = NULL;
+ char *pid_file = NULL;
+ char *lease_entries = NULL;
+ char *custom_lease_file = NULL;
+ const char *ip = NULL;
+ const char *mac = NULL;
+ const char *iaid = virGetEnvAllowSUID("DNSMASQ_IAID");
+ const char *clientid = virGetEnvAllowSUID("DNSMASQ_CLIENT_ID");
+ const char *interface = virGetEnvAllowSUID("DNSMASQ_INTERFACE");
+ const char *exptime_tmp = virGetEnvAllowSUID("DNSMASQ_LEASE_EXPIRES");
+ const char *hostname = virGetEnvAllowSUID("DNSMASQ_SUPPLIED_HOSTNAME");
+ const char *leases_str = NULL;
+ long long currtime = 0;
+ long long expirytime = 0;
+ size_t i = 0;
+ int size = 0;
+ int action = -1;
+ int pid_file_fd = -1;
+ int rv = EXIT_FAILURE;
+ int custom_lease_file_len = 0;
+ bool add = false;
+ bool delete = false;
+ virJSONValuePtr lease_new = NULL;
+ virJSONValuePtr lease_tmp = NULL;
+ virJSONValuePtr leases_array = NULL;
+ virJSONValuePtr leases_array_new = NULL;
+
+ virSetErrorFunc(NULL, NULL);
+ virSetErrorLogPriorityFunc(NULL);
+
+ program_name = argv[0];
+
+ if (setlocale(LC_ALL, "") == NULL ||
+ bindtextdomain(PACKAGE, LOCALEDIR) == NULL ||
+ textdomain(PACKAGE) == NULL) {
+ fprintf(stderr, _("%s: initialization failed\n"), program_name);
+ exit(EXIT_FAILURE);
+ }
+
+ if (virThreadInitialize() < 0 ||
+ virErrorInitialize() < 0) {
+ fprintf(stderr, _("%s: initialization failed\n"), program_name);
+ exit(EXIT_FAILURE);
+ }
+
+ /* Doesn't hurt to check */
+ if (argc > 1) {
+ if (STREQ(argv[1], "--help"))
+ usage(EXIT_SUCCESS);
+
+ if (STREQ(argv[1], "--version")) {
+ helperVersion(argv[0]);
+ exit(EXIT_SUCCESS);
+ }
+ }
+
+ if (argc != 4 && argc != 5) {
+ /* Refer man page of dnsmasq --dhcp-script for more details */
+ usage(EXIT_FAILURE);
+ }
+
+ /* Make sure dnsmasq knows the interface. The interface name is not known
+ * when dnsmasq (re)starts and throws 'del' events for expired leases.
+ * So, if any old lease has expired, it will be automatically removed the
+ * next time this program is invoked */
+ if (!interface)
+ goto cleanup;
+
+ ip = argv[3];
+ mac = argv[2];
+ action = virLeaseActionTypeFromString(argv[1]);
+
+ /* In case hostname is known, it is the 5th argument */
+ if (argc == 5)
+ hostname = argv[4];
+
+ 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';
+
+ /* Check if it is an IPv6 lease */
+ if (virGetEnvAllowSUID("DNSMASQ_IAID")) {
+ mac = virGetEnvAllowSUID("DNSMASQ_MAC");
+ clientid = argv[2];
+ }
+
+ if (virAsprintf(&custom_lease_file,
+ LOCALSTATEDIR "/lib/libvirt/dnsmasq/%s.status",
+ interface) < 0)
+ goto cleanup;
+
+ if (VIR_STRDUP(pid_file, LOCALSTATEDIR "/run/leaseshelper.pid") < 0)
+ goto cleanup;
+
+ /* Try to claim the pidfile, exiting if we can't */
+ if ((pid_file_fd = virPidFileAcquirePath(pid_file, true, getpid())) < 0)
+ goto cleanup;
+
+ /* Since interfaces can be hot plugged, we need to make sure that the
+ * corresponding custom lease file exists. If not, 'touch' it */
+ if (virFileTouch(custom_lease_file, 0644) < 0)
+ goto cleanup;
+
+ /* Read entire contents */
+ if ((custom_lease_file_len = virFileReadAll(custom_lease_file,
+ VIR_NETWORK_DHCP_LEASE_FILE_SIZE_MAX,
+ &lease_entries)) < 0) {
+ goto cleanup;
+ }
+
+ if (action == VIR_LEASE_ACTION_ADD ||
+ action == VIR_LEASE_ACTION_OLD ||
+ action == VIR_LEASE_ACTION_DEL) {
+ /* Custom ipv6 leases *will not* be created if the env-var DNSMASQ_MAC
+ * is not set. In the special case, when the $(interface).status file
+ * is not already present and dnsmasq is (re)started, the corresponding
+ * ipv6 custom lease will be created only when the guest sends the
+ * 'old' action for its existing ipv6 interfaces.
+ *
+ * According to rfc3315, the combination of DUID and IAID can be used
+ * to uniquely identify each ipv6 guest interface. So, in future, if
+ * we introduce virNetworkGetDHCPLeaseBy(IAID|DUID|IAID+DUID) for ipv6
+ * interfaces, then, the following if condition won't be required, as
+ * the new lease will be created irrespective of whether the MACID is
+ * known or not.
+ */
+ if (mac || action == VIR_LEASE_ACTION_DEL) {
+ /* Delete the corresponding lease, if it already exists */
+ delete = true;
+ if (action == VIR_LEASE_ACTION_ADD ||
+ action == VIR_LEASE_ACTION_OLD) {
+ add = true;
+ /* Create new lease */
+ if (!(lease_new = virJSONValueNewObject())) {
+ virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
+ _("failed to create json"));
+ goto cleanup;
+ }
+
+ if (virStrToLong_ll(exptime, NULL, 10, &expirytime) < 0) {
+ virReportError(VIR_ERR_INTERNAL_ERROR,
+ _("Unable to convert lease expiry time to long long: %s"),
+ exptime);
+ 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 (expirytime && virJSONValueObjectAppendNumberLong(lease_new, "expiry-time", expirytime) < 0)
+ goto cleanup;
+ }
+ }
+ } else {
+ fprintf(stderr, _("Unsupported action: %s\n"),
+ virLeaseActionTypeToString(action));
+ exit(EXIT_FAILURE);
+ }
+ /* Check for previous leases */
+ if (custom_lease_file_len) {
+ if (!(leases_array = virJSONValueFromString(lease_entries))) {
+ virReportError(VIR_ERR_INTERNAL_ERROR,
+ _("invalid json in file: %s"), custom_lease_file);
+ goto cleanup;
+ }
+
+ if ((size = virJSONValueArraySize(leases_array)) < 0) {
+ virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
+ _("couldn't fetch array of leases"));
+ goto cleanup;
+ }
+ }
+
+ if (!(leases_array_new = virJSONValueNewArray())) {
+ virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
+ _("failed to create json"));
+ goto cleanup;
+ }
+
+ currtime = (long long) time(NULL);
+
+ for (i = 0; i < size; i++) {
+ const char *ip_tmp = NULL;
+ long long expirytime_tmp = -1;
+
+ 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_tmp) < 0)) {
+ virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
+ _("failed to parse json"));
+ goto cleanup;
+ }
+
+ /* Check whether lease has expired or not */
+ if (expirytime_tmp < currtime)
+ continue;
+
+ /* Check whether lease has to be included or not */
+ if (delete && STREQ(ip_tmp, ip))
+ continue;
+
+ /* Add 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;
+ }
+ }
+
+ if (add) {
+ if (virJSONValueArrayAppend(leases_array_new, lease_new) < 0) {
+ virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
+ _("failed to create json"));
+ goto cleanup;
+ }
+ }
+
+ if (!(leases_str = virJSONValueToString(leases_array_new, true))) {
+ virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
+ _("empty json array"));
+ goto cleanup;
+ }
+
+ /* Write to file */
+ if (virFileRewrite(custom_lease_file, 0644,
+ customLeaseRewriteFile, &leases_str) < 0)
+ goto cleanup;
+
+ rv = EXIT_SUCCESS;
+
+ cleanup:
+ if (pid_file_fd != -1)
+ virPidFileReleasePath(pid_file, pid_file_fd);
+
+ VIR_FREE(pid_file);
+ VIR_FREE(exptime_tmp);
+ VIR_FREE(custom_lease_file);
+ virJSONValueFree(lease_new);
+ virJSONValueFree(leases_array);
+ virJSONValueFree(leases_array_new);
+
+ return rv;
+}
projects / libvirt.git / commitdiff