]> git.proxmox.com Git - pve-common.git/blob - src/PVE/Network.pm
bdbf3d680cbd579be0c31c36a09a3d907d9b7782
[pve-common.git] / src / PVE / Network.pm
1 package PVE::Network;
2
3 use strict;
4 use warnings;
5
6 use PVE::INotify;
7 use PVE::ProcFSTools;
8 use PVE::Tools qw(run_command lock_file);
9
10 use File::Basename;
11 use IO::Socket::IP;
12 use Net::IP;
13 use POSIX qw(ECONNREFUSED);
14 use Socket qw(NI_NUMERICHOST NI_NUMERICSERV);
15
16 # host network related utility functions
17
18 our $PHYSICAL_NIC_RE = qr/(?:eth\d+|en[^:.]+|ib\d+)/;
19
20 our $ipv4_reverse_mask = [
21 '0.0.0.0',
22 '128.0.0.0',
23 '192.0.0.0',
24 '224.0.0.0',
25 '240.0.0.0',
26 '248.0.0.0',
27 '252.0.0.0',
28 '254.0.0.0',
29 '255.0.0.0',
30 '255.128.0.0',
31 '255.192.0.0',
32 '255.224.0.0',
33 '255.240.0.0',
34 '255.248.0.0',
35 '255.252.0.0',
36 '255.254.0.0',
37 '255.255.0.0',
38 '255.255.128.0',
39 '255.255.192.0',
40 '255.255.224.0',
41 '255.255.240.0',
42 '255.255.248.0',
43 '255.255.252.0',
44 '255.255.254.0',
45 '255.255.255.0',
46 '255.255.255.128',
47 '255.255.255.192',
48 '255.255.255.224',
49 '255.255.255.240',
50 '255.255.255.248',
51 '255.255.255.252',
52 '255.255.255.254',
53 '255.255.255.255',
54 ];
55
56 our $ipv4_mask_hash_localnet = {
57 '255.0.0.0' => 8,
58 '255.128.0.0' => 9,
59 '255.192.0.0' => 10,
60 '255.224.0.0' => 11,
61 '255.240.0.0' => 12,
62 '255.248.0.0' => 13,
63 '255.252.0.0' => 14,
64 '255.254.0.0' => 15,
65 '255.255.0.0' => 16,
66 '255.255.128.0' => 17,
67 '255.255.192.0' => 18,
68 '255.255.224.0' => 19,
69 '255.255.240.0' => 20,
70 '255.255.248.0' => 21,
71 '255.255.252.0' => 22,
72 '255.255.254.0' => 23,
73 '255.255.255.0' => 24,
74 '255.255.255.128' => 25,
75 '255.255.255.192' => 26,
76 '255.255.255.224' => 27,
77 '255.255.255.240' => 28,
78 '255.255.255.248' => 29,
79 '255.255.255.252' => 30,
80 '255.255.255.254' => 31,
81 '255.255.255.255' => 32,
82 };
83
84 sub setup_tc_rate_limit {
85 my ($iface, $rate, $burst, $debug) = @_;
86
87 # these are allowed / expected to fail, e.g. when there is no previous rate limit to remove
88 eval { run_command("/sbin/tc class del dev $iface parent 1: classid 1:1 >/dev/null 2>&1"); };
89 eval { run_command("/sbin/tc filter del dev $iface parent ffff: protocol all pref 50 u32 >/dev/null 2>&1"); };
90 eval { run_command("/sbin/tc qdisc del dev $iface ingress >/dev/null 2>&1"); };
91 eval { run_command("/sbin/tc qdisc del dev $iface root >/dev/null 2>&1"); };
92
93 return if !$rate;
94
95 # tbf does not work for unknown reason
96 #$TC qdisc add dev $DEV root tbf rate $RATE latency 100ms burst $BURST
97 # so we use htb instead
98 run_command("/sbin/tc qdisc add dev $iface root handle 1: htb default 1");
99 run_command("/sbin/tc class add dev $iface parent 1: classid 1:1 " .
100 "htb rate ${rate}bps burst ${burst}b");
101
102 run_command("/sbin/tc qdisc add dev $iface handle ffff: ingress");
103 run_command("/sbin/tc filter add dev $iface parent ffff: " .
104 "prio 50 basic " .
105 "police rate ${rate}bps burst ${burst}b mtu 64kb " .
106 "drop");
107
108 if ($debug) {
109 print "DEBUG tc settings\n";
110 system("/sbin/tc qdisc ls dev $iface");
111 system("/sbin/tc class ls dev $iface");
112 system("/sbin/tc filter ls dev $iface parent ffff:");
113 }
114 }
115
116 sub tap_rate_limit {
117 my ($iface, $rate) = @_;
118
119 my $debug = 0;
120 $rate = int($rate*1024*1024) if $rate;
121 my $burst = 1024*1024;
122
123 setup_tc_rate_limit($iface, $rate, $burst, $debug);
124 }
125
126 my $read_bridge_mtu = sub {
127 my ($bridge) = @_;
128
129 my $mtu = PVE::Tools::file_read_firstline("/sys/class/net/$bridge/mtu");
130 die "bridge '$bridge' does not exist\n" if !$mtu;
131 # avoid insecure dependency;
132 die "unable to parse mtu value" if $mtu !~ /^(\d+)$/;
133 $mtu = int($1);
134
135 return $mtu;
136 };
137
138 my $parse_tap_device_name = sub {
139 my ($iface, $noerr) = @_;
140
141 my ($vmid, $devid);
142
143 if ($iface =~ m/^tap(\d+)i(\d+)$/) {
144 $vmid = $1;
145 $devid = $2;
146 } elsif ($iface =~ m/^veth(\d+)i(\d+)$/) {
147 $vmid = $1;
148 $devid = $2;
149 } else {
150 return undef if $noerr;
151 die "can't create firewall bridge for random interface name '$iface'\n";
152 }
153
154 return ($vmid, $devid);
155 };
156
157 my $compute_fwbr_names = sub {
158 my ($vmid, $devid) = @_;
159
160 my $fwbr = "fwbr${vmid}i${devid}";
161 # Note: the firewall use 'fwln+' to filter traffic to VMs
162 my $vethfw = "fwln${vmid}i${devid}";
163 my $vethfwpeer = "fwpr${vmid}p${devid}";
164 my $ovsintport = "fwln${vmid}o${devid}";
165
166 return ($fwbr, $vethfw, $vethfwpeer, $ovsintport);
167 };
168
169 sub iface_delete($) {
170 my ($iface) = @_;
171 run_command(['/sbin/ip', 'link', 'delete', 'dev', $iface], noerr => 1)
172 == 0 or die "failed to delete interface '$iface'\n";
173 }
174
175 sub iface_create($$@) {
176 my ($iface, $type, @args) = @_;
177 run_command(['/sbin/ip', 'link', 'add', $iface, 'type', $type, @args], noerr => 1)
178 == 0 or die "failed to create interface '$iface'\n";
179 }
180
181 sub iface_set($@) {
182 my ($iface, @opts) = @_;
183 run_command(['/sbin/ip', 'link', 'set', $iface, @opts], noerr => 1)
184 == 0 or die "failed to set interface options for '$iface' (".join(' ', @opts).")\n";
185 }
186
187 # helper for nicer error messages:
188 sub iface_set_master($$) {
189 my ($iface, $master) = @_;
190 if (defined($master)) {
191 eval { iface_set($iface, 'master', $master) };
192 die "can't enslave '$iface' to '$master'\n" if $@;
193 } else {
194 eval { iface_set($iface, 'nomaster') };
195 die "can't unenslave '$iface'\n" if $@;
196 }
197 }
198
199 my $cond_create_bridge = sub {
200 my ($bridge) = @_;
201
202 if (! -d "/sys/class/net/$bridge") {
203 iface_create($bridge, 'bridge');
204 disable_ipv6($bridge);
205 }
206 };
207
208 sub disable_ipv6 {
209 my ($iface) = @_;
210 return if !-d '/proc/sys/net/ipv6'; # ipv6 might be completely disabled
211 my $file = "/proc/sys/net/ipv6/conf/$iface/disable_ipv6";
212 open(my $fh, '>', $file) or die "failed to open $file for writing: $!\n";
213 print {$fh} "1\n" or die "failed to disable link-local ipv6 for $iface\n";
214 close($fh);
215 }
216
217 my $bridge_add_interface = sub {
218 my ($bridge, $iface, $tag, $trunks) = @_;
219
220 # drop link local address (it can't be used when on a bridge anyway)
221 disable_ipv6($iface);
222 iface_set_master($iface, $bridge);
223
224 my $vlan_aware = PVE::Tools::file_read_firstline("/sys/class/net/$bridge/bridge/vlan_filtering");
225
226 if ($vlan_aware) {
227 if ($tag) {
228 system({'/sbin/bridge'} 'bridge', 'vlan', 'del', 'dev', $iface, 'vid', '1-4094') == 0
229 or die "failed to remove default vlan tags of $iface\n";
230 system({'/sbin/bridge'} 'bridge', 'vlan', 'add', 'dev', $iface, 'vid', $tag, 'pvid', 'untagged') == 0
231 or die "unable to add vlan $tag to interface $iface\n";
232
233 warn "Caution: Setting VLAN ID 1 on a VLAN aware bridge may be dangerous\n" if $tag == 1;
234 } else {
235 system("/sbin/bridge vlan add dev $iface vid 2-4094") == 0 ||
236 die "unable to add default vlan tags to interface $iface\n" if !$trunks;
237 }
238
239 if ($trunks) {
240 my @trunks_array = split /;/, $trunks;
241 foreach my $trunk (@trunks_array) {
242 system("/sbin/bridge vlan add dev $iface vid $trunk") == 0 ||
243 die "unable to add vlan $trunk to interface $iface\n";
244 }
245 }
246 }
247 };
248
249 my $ovs_bridge_add_port = sub {
250 my ($bridge, $iface, $tag, $internal, $trunks) = @_;
251
252 $trunks =~ s/;/,/g if $trunks;
253
254 my $cmd = "/usr/bin/ovs-vsctl add-port $bridge $iface";
255 $cmd .= " tag=$tag" if $tag;
256 $cmd .= " trunks=". join(',', $trunks) if $trunks;
257 $cmd .= " vlan_mode=native-untagged" if $tag && $trunks;
258
259 $cmd .= " -- set Interface $iface type=internal" if $internal;
260 system($cmd) == 0 ||
261 die "can't add ovs port '$iface'\n";
262 disable_ipv6($iface);
263 };
264
265 my $activate_interface = sub {
266 my ($iface) = @_;
267
268 system("/sbin/ip link set $iface up") == 0 ||
269 die "can't activate interface '$iface'\n";
270 };
271
272 sub tap_create {
273 my ($iface, $bridge) = @_;
274
275 my $have_sdn;
276 eval {
277 require PVE::Network::SDN::Zones;
278 $have_sdn = 1;
279 };
280
281 if ($have_sdn) {
282 my ($bridgesdn, undef) = PVE::Network::SDN::Zones::get_bridge_vlan($bridge);
283 $bridge = $bridgesdn if $bridgesdn;
284 }
285
286 die "unable to get bridge setting\n" if !$bridge;
287
288 my $bridgemtu = &$read_bridge_mtu($bridge);
289
290 eval {
291 disable_ipv6($iface);
292 PVE::Tools::run_command(['/sbin/ip', 'link', 'set', $iface, 'up', 'promisc', 'on', 'mtu', $bridgemtu]);
293 };
294 die "interface activation failed\n" if $@;
295 }
296
297 sub veth_create {
298 my ($veth, $vethpeer, $bridge, $mac) = @_;
299
300 my $have_sdn;
301 eval {
302 require PVE::Network::SDN::Zones;
303 $have_sdn = 1;
304 };
305
306 if ($have_sdn) {
307 my ($bridgesdn, undef) = PVE::Network::SDN::Zones::get_bridge_vlan($bridge);
308 $bridge = $bridgesdn if $bridgesdn;
309 }
310
311 die "unable to get bridge setting\n" if !$bridge;
312
313 my $bridgemtu = &$read_bridge_mtu($bridge);
314
315 # create veth pair
316 if (! -d "/sys/class/net/$veth") {
317 my $cmd = "/sbin/ip link add name $veth mtu $bridgemtu type veth peer name $vethpeer mtu $bridgemtu";
318 $cmd .= " addr $mac" if $mac;
319 system($cmd) == 0 || die "can't create interface $veth\n";
320 }
321
322 # up vethpair
323 disable_ipv6($veth);
324 disable_ipv6($vethpeer);
325 &$activate_interface($veth);
326 &$activate_interface($vethpeer);
327 }
328
329 sub veth_delete {
330 my ($veth) = @_;
331
332 if (-d "/sys/class/net/$veth") {
333 iface_delete($veth);
334 }
335 eval { tap_unplug($veth) };
336 }
337
338 my $create_firewall_bridge_linux = sub {
339 my ($iface, $bridge, $tag, $trunks) = @_;
340
341 my ($vmid, $devid) = &$parse_tap_device_name($iface);
342 my ($fwbr, $vethfw, $vethfwpeer) = &$compute_fwbr_names($vmid, $devid);
343
344 &$cond_create_bridge($fwbr);
345 &$activate_interface($fwbr);
346
347 copy_bridge_config($bridge, $fwbr);
348 veth_create($vethfw, $vethfwpeer, $bridge);
349
350 &$bridge_add_interface($fwbr, $vethfw);
351 &$bridge_add_interface($bridge, $vethfwpeer, $tag, $trunks);
352
353 &$bridge_add_interface($fwbr, $iface);
354 };
355
356 my $create_firewall_bridge_ovs = sub {
357 my ($iface, $bridge, $tag, $trunks) = @_;
358
359 my ($vmid, $devid) = &$parse_tap_device_name($iface);
360 my ($fwbr, undef, undef, $ovsintport) = &$compute_fwbr_names($vmid, $devid);
361
362 my $bridgemtu = &$read_bridge_mtu($bridge);
363
364 &$cond_create_bridge($fwbr);
365 &$activate_interface($fwbr);
366
367 &$bridge_add_interface($fwbr, $iface);
368
369 &$ovs_bridge_add_port($bridge, $ovsintport, $tag, 1, $trunks);
370 &$activate_interface($ovsintport);
371
372 # set the same mtu for ovs int port
373 PVE::Tools::run_command(['/sbin/ip', 'link', 'set', $ovsintport, 'mtu', $bridgemtu]);
374
375 &$bridge_add_interface($fwbr, $ovsintport);
376 };
377
378 my $cleanup_firewall_bridge = sub {
379 my ($iface) = @_;
380
381 my ($vmid, $devid) = &$parse_tap_device_name($iface, 1);
382 return if !defined($vmid);
383 my ($fwbr, $vethfw, $vethfwpeer, $ovsintport) = &$compute_fwbr_names($vmid, $devid);
384
385 # cleanup old port config from any openvswitch bridge
386 if (-d "/sys/class/net/$ovsintport") {
387 run_command("/usr/bin/ovs-vsctl del-port $ovsintport", outfunc => sub {}, errfunc => sub {});
388 }
389
390 # delete old vethfw interface
391 veth_delete($vethfw);
392
393 # cleanup fwbr bridge
394 if (-d "/sys/class/net/$fwbr") {
395 iface_delete($fwbr);
396 }
397 };
398
399 sub tap_plug {
400 my ($iface, $bridge, $tag, $firewall, $trunks, $rate) = @_;
401
402 my $have_sdn;
403 eval {
404 require PVE::Network::SDN::Zones;
405 $have_sdn = 1;
406 };
407
408 if ($have_sdn) {
409 my ($bridgesdn, $tag) = PVE::Network::SDN::Zones::get_bridge_vlan($bridge);
410 $bridge = $bridgesdn if $bridgesdn;
411 $trunks = undef;
412 }
413
414 #cleanup old port config from any openvswitch bridge
415 eval {run_command("/usr/bin/ovs-vsctl del-port $iface", outfunc => sub {}, errfunc => sub {}) };
416
417 if (-d "/sys/class/net/$bridge/bridge") {
418 &$cleanup_firewall_bridge($iface); # remove stale devices
419
420 my $vlan_aware = PVE::Tools::file_read_firstline("/sys/class/net/$bridge/bridge/vlan_filtering");
421
422 if (!$vlan_aware) {
423 die "vlan aware feature need to be enabled to use trunks" if $trunks;
424 my $newbridge = activate_bridge_vlan($bridge, $tag);
425 copy_bridge_config($bridge, $newbridge) if $bridge ne $newbridge;
426 $bridge = $newbridge;
427 $tag = undef;
428 }
429
430 if ($firewall) {
431 &$create_firewall_bridge_linux($iface, $bridge, $tag, $trunks);
432 } else {
433 &$bridge_add_interface($bridge, $iface, $tag, $trunks);
434 }
435
436 } else {
437 &$cleanup_firewall_bridge($iface); # remove stale devices
438
439 if ($firewall) {
440 &$create_firewall_bridge_ovs($iface, $bridge, $tag, $trunks);
441 } else {
442 &$ovs_bridge_add_port($bridge, $iface, $tag, undef, $trunks);
443 }
444 }
445
446 tap_rate_limit($iface, $rate);
447 }
448
449 sub tap_unplug {
450 my ($iface) = @_;
451
452 my $path= "/sys/class/net/$iface/brport/bridge";
453 if (-l $path) {
454 my $bridge = basename(readlink($path));
455 #avoid insecure dependency;
456 ($bridge) = $bridge =~ /(\S+)/;
457
458 iface_set_master($iface, undef);
459 }
460
461 &$cleanup_firewall_bridge($iface);
462 #cleanup old port config from any openvswitch bridge
463 eval {run_command("/usr/bin/ovs-vsctl del-port $iface", outfunc => sub {}, errfunc => sub {}) };
464 }
465
466 sub copy_bridge_config {
467 my ($br0, $br1) = @_;
468
469 return if $br0 eq $br1;
470
471 my $br_configs = [ 'ageing_time', 'stp_state', 'priority', 'forward_delay',
472 'hello_time', 'max_age', 'multicast_snooping', 'multicast_querier'];
473
474 foreach my $sysname (@$br_configs) {
475 eval {
476 my $v0 = PVE::Tools::file_read_firstline("/sys/class/net/$br0/bridge/$sysname");
477 my $v1 = PVE::Tools::file_read_firstline("/sys/class/net/$br1/bridge/$sysname");
478 if ($v0 ne $v1) {
479 PVE::ProcFSTools::write_proc_entry("/sys/class/net/$br1/bridge/$sysname", $v0);
480 }
481 };
482 warn $@ if $@;
483 }
484 }
485
486 sub activate_bridge_vlan_slave {
487 my ($bridgevlan, $iface, $tag) = @_;
488 my $ifacevlan = "${iface}.$tag";
489
490 # create vlan on $iface is not already exist
491 if (! -d "/sys/class/net/$ifacevlan") {
492 system("/sbin/ip link add link $iface name $ifacevlan type vlan id $tag") == 0 ||
493 die "can't add vlan tag $tag to interface $iface\n";
494
495 # remove ipv6 link-local address before activation
496 disable_ipv6($ifacevlan);
497 }
498
499 # be sure to have the $ifacevlan up
500 &$activate_interface($ifacevlan);
501
502 # test if $vlaniface is already enslaved in another bridge
503 my $path= "/sys/class/net/$ifacevlan/brport/bridge";
504 if (-l $path) {
505 my $tbridge = basename(readlink($path));
506 if ($tbridge ne $bridgevlan) {
507 die "interface $ifacevlan already exist in bridge $tbridge\n";
508 } else {
509 # Port already attached to bridge: do nothing.
510 return;
511 }
512 }
513
514 # add $ifacevlan to the bridge
515 &$bridge_add_interface($bridgevlan, $ifacevlan);
516 }
517
518 sub activate_bridge_vlan {
519 my ($bridge, $tag_param) = @_;
520
521 die "bridge '$bridge' is not active\n" if ! -d "/sys/class/net/$bridge";
522
523 return $bridge if !defined($tag_param); # no vlan, simply return
524
525 my $tag = int($tag_param);
526
527 die "got strange vlan tag '$tag_param'\n" if $tag < 1 || $tag > 4094;
528
529 my $bridgevlan = "${bridge}v$tag";
530
531 my @ifaces = ();
532 my $dir = "/sys/class/net/$bridge/brif";
533 PVE::Tools::dir_glob_foreach($dir, '(((eth|bond)\d+|en[^.]+)(\.\d+)?)', sub {
534 push @ifaces, $_[0];
535 });
536
537 die "no physical interface on bridge '$bridge'\n" if scalar(@ifaces) == 0;
538
539 lock_network(sub {
540 # add bridgevlan if it doesn't already exist
541 if (! -d "/sys/class/net/$bridgevlan") {
542 iface_create($bridgevlan, 'bridge');
543 }
544
545 # for each physical interface (eth or bridge) bind them to bridge vlan
546 foreach my $iface (@ifaces) {
547 activate_bridge_vlan_slave($bridgevlan, $iface, $tag);
548 }
549
550 #fixme: set other bridge flags
551
552 # remove ipv6 link-local address before activation
553 disable_ipv6($bridgevlan);
554 # be sure to have the bridge up
555 &$activate_interface($bridgevlan);
556 });
557 return $bridgevlan;
558 }
559
560 sub tcp_ping {
561 my ($host, $port, $timeout) = @_;
562
563 my $refused = 1;
564
565 $timeout = 3 if !$timeout; # sane default
566 if (!$port) {
567 # Net::Ping defaults to the echo port
568 $port = 7;
569 } else {
570 # Net::Ping's port_number() implies service_check(1)
571 $refused = 0;
572 }
573
574 my ($sock, $result);
575 eval {
576 $result = PVE::Tools::run_with_timeout($timeout, sub {
577 $sock = IO::Socket::IP->new(PeerHost => $host, PeerPort => $port, Type => SOCK_STREAM);
578 $result = $refused if $! == ECONNREFUSED;
579 });
580 };
581 if ($sock) {
582 $sock->close();
583 $result = 1;
584 }
585 return $result;
586 }
587
588 sub IP_from_cidr {
589 my ($cidr, $version) = @_;
590
591 return if $cidr !~ m!^(\S+?)/(\S+)$!;
592 my ($ip, $prefix) = ($1, $2);
593
594 my $ipobj = Net::IP->new($ip, $version);
595 return if !$ipobj;
596
597 $version = $ipobj->version();
598
599 my $binmask = Net::IP::ip_get_mask($prefix, $version);
600 return if !$binmask;
601
602 my $masked_binip = $ipobj->binip() & $binmask;
603 my $masked_ip = Net::IP::ip_bintoip($masked_binip, $version);
604 return Net::IP->new("$masked_ip/$prefix");
605 }
606
607 sub is_ip_in_cidr {
608 my ($ip, $cidr, $version) = @_;
609
610 my $cidr_obj = IP_from_cidr($cidr, $version);
611 return undef if !$cidr_obj;
612
613 my $ip_obj = Net::IP->new($ip, $version);
614 return undef if !$ip_obj;
615
616 return $cidr_obj->overlaps($ip_obj) == $Net::IP::IP_B_IN_A_OVERLAP;
617 }
618
619
620 sub get_local_ip_from_cidr {
621 my ($cidr) = @_;
622
623 my $IPs = [];
624 run_command(['/sbin/ip', 'address', 'show', 'to', $cidr, 'up'], outfunc => sub {
625 if ($_[0] =~ m!^\s*inet(?:6)?\s+($PVE::Tools::IPRE)(?:/\d+|\s+peer\s+)!) {
626 push @$IPs, $1;
627 }
628 });
629
630 return $IPs;
631 }
632
633 sub addr_to_ip {
634 my ($addr) = @_;
635 my ($err, $host, $port) = Socket::getnameinfo($addr, NI_NUMERICHOST | NI_NUMERICSERV);
636 die "failed to get numerical host address: $err\n" if $err;
637 return ($host, $port) if wantarray;
638 return $host;
639 }
640
641 sub get_ip_from_hostname {
642 my ($hostname, $noerr) = @_;
643
644 my @res = eval { PVE::Tools::getaddrinfo_all($hostname) };
645 if ($@) {
646 die "hostname lookup '$hostname' failed - $@" if !$noerr;
647 return undef;
648 }
649
650 my ($ip, $family);
651 for my $ai (@res) {
652 $family = $ai->{family};
653 my $tmpip = addr_to_ip($ai->{addr});
654 if ($tmpip !~ m/^127\.|^::1$/) {
655 $ip = $tmpip;
656 last;
657 }
658 }
659 if (!defined($ip) ) {
660 die "hostname lookup '$hostname' failed - got local IP address '$ip'\n" if !$noerr;
661 return undef;
662 }
663
664 return wantarray ? ($ip, $family) : $ip;
665 }
666
667 sub lock_network {
668 my ($code, @param) = @_;
669 my $res = lock_file('/var/lock/pve-network.lck', 10, $code, @param);
670 die $@ if $@;
671 return $res;
672 }
673
674 1;