summaryrefslogtreecommitdiff
path: root/src/network/networkd-dhcp4.c
blob: 5e4ff2b80b796ea33de24b9c80076f408f6db63d (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/

/***
  This file is part of systemd.

  Copyright 2013-2014 Tom Gundersen <teg@jklm.no>

  systemd 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.

  systemd 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 systemd; If not, see <http://www.gnu.org/licenses/>.
***/

#include <netinet/ether.h>
#include <linux/if.h>

#include "networkd-link.h"
#include "network-internal.h"
#include "dhcp-lease-internal.h"

static int dhcp4_route_handler(sd_rtnl *rtnl, sd_rtnl_message *m,
                               void *userdata) {
        _cleanup_link_unref_ Link *link = userdata;
        int r;

        assert(link);
        assert(link->dhcp4_messages);

        link->dhcp4_messages --;

        r = sd_rtnl_message_get_errno(m);
        if (r < 0 && r != -EEXIST) {
                log_error_link(link, "could not set DHCPv4 route: %s",
                               strerror(-r));
                link_enter_failed(link);
        }

        if (!link->dhcp4_messages) {
                link->dhcp4_configured = true;
                link_client_handler(link);
        }

        return 1;
}

static int link_set_dhcp_routes(Link *link) {
        struct in_addr gateway;
        struct sd_dhcp_route *static_routes;
        int r, n, i;

        assert(link);
        assert(link->dhcp_lease);

        r = sd_dhcp_lease_get_router(link->dhcp_lease, &gateway);
        if (r < 0 && r != -ENOENT) {
                log_warning_link(link,
                                 "DHCP error: could not get gateway: %s",
                                 strerror(-r));
                return r;
        }
        if (r >= 0) {
                _cleanup_route_free_ Route *route = NULL;
                _cleanup_route_free_ Route *route_gw = NULL;

                r = route_new_dynamic(&route, RTPROT_DHCP);
                if (r < 0) {
                        log_error_link(link,
                                       "Could not allocate route: %s",
                                       strerror(-r));
                        return r;
                }

                r = route_new_dynamic(&route_gw, RTPROT_DHCP);
                if (r < 0) {
                log_error_link(link,
                               "Could not allocate route: %s",
                               strerror(-r));
                               return r;
                }

                /* The dhcp netmask may mask out the gateway. Add an explicit
                 * route for the gw host so that we can route no matter the
                 * netmask or existing kernel route tables. */
                route_gw->family = AF_INET;
                route_gw->dst_addr.in = gateway;
                route_gw->dst_prefixlen = 32;
                route_gw->scope = RT_SCOPE_LINK;
                route_gw->metrics = DHCP_ROUTE_METRIC;

                r = route_configure(route_gw, link, &dhcp4_route_handler);
                if (r < 0) {
                        log_warning_link(link,
                                         "could not set host route: %s",
                                         strerror(-r));
                        return r;
                }

                link->dhcp4_messages ++;

                route->family = AF_INET;
                route->in_addr.in = gateway;
                route->metrics = DHCP_ROUTE_METRIC;

                r = route_configure(route, link, &dhcp4_route_handler);
                if (r < 0) {
                        log_warning_link(link,
                                         "could not set routes: %s",
                                         strerror(-r));
                        link_enter_failed(link);
                        return r;
                }

                link->dhcp4_messages ++;
        }

        n = sd_dhcp_lease_get_routes(link->dhcp_lease, &static_routes);
        if (n == -ENOENT)
                return 0;
        if (n < 0) {
                log_warning_link(link,
                                 "DHCP error: could not get routes: %s",
                                 strerror(-n));

                return n;
        }

        for (i = 0; i < n; i++) {
                _cleanup_route_free_ Route *route = NULL;

                r = route_new_dynamic(&route, RTPROT_DHCP);
                if (r < 0) {
                        log_error_link(link, "Could not allocate route: %s",
                                       strerror(-r));
                        return r;
                }

                route->family = AF_INET;
                route->in_addr.in = static_routes[i].gw_addr;
                route->dst_addr.in = static_routes[i].dst_addr;
                route->dst_prefixlen = static_routes[i].dst_prefixlen;
                route->metrics = DHCP_ROUTE_METRIC;

                r = route_configure(route, link, &dhcp4_route_handler);
                if (r < 0) {
                        log_warning_link(link,
                                         "could not set host route: %s",
                                         strerror(-r));
                        return r;
                }

                link->dhcp4_messages ++;
        }

        return 0;
}

static int dhcp_lease_lost(Link *link) {
        _cleanup_address_free_ Address *address = NULL;
        struct in_addr addr;
        struct in_addr netmask;
        struct in_addr gateway;
        unsigned prefixlen;
        int r;

        assert(link);
        assert(link->dhcp_lease);

        log_warning_link(link, "DHCP lease lost");

        if (link->network->dhcp_routes) {
                struct sd_dhcp_route *routes;
                int n, i;

                n = sd_dhcp_lease_get_routes(link->dhcp_lease, &routes);
                if (n >= 0) {
                        for (i = 0; i < n; i++) {
                                _cleanup_route_free_ Route *route = NULL;

                                r = route_new_dynamic(&route, RTPROT_UNSPEC);
                                if (r >= 0) {
                                        route->family = AF_INET;
                                        route->in_addr.in = routes[i].gw_addr;
                                        route->dst_addr.in = routes[i].dst_addr;
                                        route->dst_prefixlen = routes[i].dst_prefixlen;

                                        route_drop(route, link,
                                                   &link_route_drop_handler);
                                }
                        }
                }
        }

        r = address_new_dynamic(&address);
        if (r >= 0) {
                r = sd_dhcp_lease_get_router(link->dhcp_lease, &gateway);
                if (r >= 0) {
                        _cleanup_route_free_ Route *route_gw = NULL;
                        _cleanup_route_free_ Route *route = NULL;

                        r = route_new_dynamic(&route_gw, RTPROT_UNSPEC);
                        if (r >= 0) {
                                route_gw->family = AF_INET;
                                route_gw->dst_addr.in = gateway;
                                route_gw->dst_prefixlen = 32;
                                route_gw->scope = RT_SCOPE_LINK;

                                route_drop(route_gw, link,
                                           &link_route_drop_handler);
                        }

                        r = route_new_dynamic(&route, RTPROT_UNSPEC);
                        if (r >= 0) {
                                route->family = AF_INET;
                                route->in_addr.in = gateway;

                                route_drop(route, link,
                                           &link_route_drop_handler);
                        }
                }

                sd_dhcp_lease_get_address(link->dhcp_lease, &addr);
                sd_dhcp_lease_get_netmask(link->dhcp_lease, &netmask);
                prefixlen = in_addr_netmask_to_prefixlen(&netmask);

                address->family = AF_INET;
                address->in_addr.in = addr;
                address->prefixlen = prefixlen;

                address_drop(address, link, &link_address_drop_handler);
        }

        if (link->network->dhcp_mtu) {
                uint16_t mtu;

                r = sd_dhcp_lease_get_mtu(link->dhcp_lease, &mtu);
                if (r >= 0 && link->original_mtu != mtu) {
                        r = link_set_mtu(link, link->original_mtu);
                        if (r < 0) {
                                log_warning_link(link,
                                                 "DHCP error: could not reset MTU");
                                link_enter_failed(link);
                                return r;
                        }
                }
        }

        if (link->network->dhcp_hostname) {
                const char *hostname = NULL;

                r = sd_dhcp_lease_get_hostname(link->dhcp_lease, &hostname);
                if (r >= 0 && hostname) {
                        r = link_set_hostname(link, "");
                        if (r < 0)
                                log_error_link(link,
                                               "Failed to reset transient hostname");
                }
        }

        link->dhcp_lease = sd_dhcp_lease_unref(link->dhcp_lease);
        link->dhcp4_configured = false;

        return 0;
}

static int dhcp4_address_handler(sd_rtnl *rtnl, sd_rtnl_message *m,
                                 void *userdata) {
        _cleanup_link_unref_ Link *link = userdata;
        int r;

        assert(link);

        r = sd_rtnl_message_get_errno(m);
        if (r < 0 && r != -EEXIST) {
                log_error_link(link, "could not set DHCPv4 address: %s",
                               strerror(-r));
                link_enter_failed(link);
        } else if (r >= 0) {
                /* calling handler directly so take a ref */
                link_ref(link);
                link_get_address_handler(rtnl, m, link);
        }

        link_set_dhcp_routes(link);

        return 1;
}

static int dhcp4_update_address(Link *link,
                                struct in_addr *address,
                                struct in_addr *netmask,
                                uint32_t lifetime) {
        _cleanup_address_free_ Address *addr = NULL;
        unsigned prefixlen;
        int r;

        assert(address);
        assert(netmask);
        assert(lifetime);

        prefixlen = in_addr_netmask_to_prefixlen(netmask);

        r = address_new_dynamic(&addr);
        if (r < 0)
                return r;

        addr->family = AF_INET;
        addr->in_addr.in.s_addr = address->s_addr;
        addr->cinfo.ifa_prefered = lifetime;
        addr->cinfo.ifa_valid = lifetime;
        addr->prefixlen = prefixlen;
        addr->broadcast.s_addr = address->s_addr | ~netmask->s_addr;

        /* use update rather than configure so that we will update the
         * lifetime of an existing address if it has already been configured */
        r = address_update(addr, link, &dhcp4_address_handler);
        if (r < 0)
                return r;

        return 0;
}

static int dhcp_lease_renew(sd_dhcp_client *client, Link *link) {
        sd_dhcp_lease *lease;
        struct in_addr address;
        struct in_addr netmask;
        uint32_t lifetime = CACHE_INFO_INFINITY_LIFE_TIME;
        int r;

        assert(link);
        assert(client);
        assert(link->network);

        r = sd_dhcp_client_get_lease(client, &lease);
        if (r < 0) {
                log_warning_link(link, "DHCP error: no lease %s",
                                 strerror(-r));
                return r;
        }

        sd_dhcp_lease_unref(link->dhcp_lease);
        link->dhcp4_configured = false;
        link->dhcp_lease = lease;

        r = sd_dhcp_lease_get_address(lease, &address);
        if (r < 0) {
                log_warning_link(link, "DHCP error: no address: %s",
                                 strerror(-r));
                return r;
        }

        r = sd_dhcp_lease_get_netmask(lease, &netmask);
        if (r < 0) {
                log_warning_link(link, "DHCP error: no netmask: %s",
                                 strerror(-r));
                return r;
        }

        if (!link->network->dhcp_critical) {
                r = sd_dhcp_lease_get_lifetime(link->dhcp_lease,
                                               &lifetime);
                if (r < 0) {
                        log_warning_link(link,
                                         "DHCP error: no lifetime: %s",
                                         strerror(-r));
                        return r;
                }
        }

        r = dhcp4_update_address(link, &address, &netmask, lifetime);
        if (r < 0) {
                log_warning_link(link, "could not update IP address: %s",
                                 strerror(-r));
                link_enter_failed(link);
                return r;
        }

        return 0;
}

static int dhcp_lease_acquired(sd_dhcp_client *client, Link *link) {
        sd_dhcp_lease *lease;
        struct in_addr address;
        struct in_addr netmask;
        struct in_addr gateway;
        unsigned prefixlen;
        uint32_t lifetime = CACHE_INFO_INFINITY_LIFE_TIME;
        int r;

        assert(client);
        assert(link);

        r = sd_dhcp_client_get_lease(client, &lease);
        if (r < 0) {
                log_warning_link(link, "DHCP error: no lease: %s",
                                 strerror(-r));
                return r;
        }

        r = sd_dhcp_lease_get_address(lease, &address);
        if (r < 0) {
                log_warning_link(link, "DHCP error: no address: %s",
                                 strerror(-r));
                return r;
        }

        r = sd_dhcp_lease_get_netmask(lease, &netmask);
        if (r < 0) {
                log_warning_link(link, "DHCP error: no netmask: %s",
                                 strerror(-r));
                return r;
        }

        prefixlen = in_addr_netmask_to_prefixlen(&netmask);

        r = sd_dhcp_lease_get_router(lease, &gateway);
        if (r < 0 && r != -ENOENT) {
                log_warning_link(link, "DHCP error: could not get gateway: %s",
                                 strerror(-r));
                return r;
        }

        if (r >= 0)
                log_struct_link(LOG_INFO, link,
                                "MESSAGE=%-*s: DHCPv4 address %u.%u.%u.%u/%u via %u.%u.%u.%u",
                                 IFNAMSIZ,
                                 link->ifname,
                                 ADDRESS_FMT_VAL(address),
                                 prefixlen,
                                 ADDRESS_FMT_VAL(gateway),
                                 "ADDRESS=%u.%u.%u.%u",
                                 ADDRESS_FMT_VAL(address),
                                 "PREFIXLEN=%u",
                                 prefixlen,
                                 "GATEWAY=%u.%u.%u.%u",
                                 ADDRESS_FMT_VAL(gateway),
                                 NULL);
        else
                log_struct_link(LOG_INFO, link,
                                "MESSAGE=%-*s: DHCPv4 address %u.%u.%u.%u/%u",
                                 IFNAMSIZ,
                                 link->ifname,
                                 ADDRESS_FMT_VAL(address),
                                 prefixlen,
                                 "ADDRESS=%u.%u.%u.%u",
                                 ADDRESS_FMT_VAL(address),
                                 "PREFIXLEN=%u",
                                 prefixlen,
                                 NULL);

        link->dhcp_lease = lease;

        if (link->network->dhcp_mtu) {
                uint16_t mtu;

                r = sd_dhcp_lease_get_mtu(lease, &mtu);
                if (r >= 0) {
                        r = link_set_mtu(link, mtu);
                        if (r < 0)
                                log_error_link(link, "Failed to set MTU "
                                               "to %" PRIu16, mtu);
                }
        }

        if (link->network->dhcp_hostname) {
                const char *hostname;

                r = sd_dhcp_lease_get_hostname(lease, &hostname);
                if (r >= 0) {
                        r = link_set_hostname(link, hostname);
                        if (r < 0)
                                log_error_link(link,
                                               "Failed to set transient hostname to '%s'",
                                               hostname);
                }
        }

        if (!link->network->dhcp_critical) {
                r = sd_dhcp_lease_get_lifetime(link->dhcp_lease,
                                               &lifetime);
                if (r < 0) {
                        log_warning_link(link,
                                         "DHCP error: no lifetime: %s",
                                         strerror(-r));
                        return r;
                }
        }

        r = dhcp4_update_address(link, &address, &netmask, lifetime);
        if (r < 0) {
                log_warning_link(link, "could not update IP address: %s",
                                 strerror(-r));
                link_enter_failed(link);
                return r;
        }

        return 0;
}
static void dhcp4_handler(sd_dhcp_client *client, int event, void *userdata) {
        Link *link = userdata;
        int r = 0;

        assert(link);
        assert(link->network);
        assert(link->manager);

        if (IN_SET(link->state, LINK_STATE_FAILED, LINK_STATE_LINGER))
                return;

        switch (event) {
                case DHCP_EVENT_EXPIRED:
                case DHCP_EVENT_STOP:
                case DHCP_EVENT_IP_CHANGE:
                        if (link->network->dhcp_critical) {
                                log_error_link(link,
                                               "DHCPv4 connection considered system critical, ignoring request to reconfigure it.");
                                return;
                        }

                        if (link->dhcp_lease) {
                                r = dhcp_lease_lost(link);
                                if (r < 0) {
                                        link_enter_failed(link);
                                        return;
                                }
                        }

                        if (event == DHCP_EVENT_IP_CHANGE) {
                                r = dhcp_lease_acquired(client, link);
                                if (r < 0) {
                                        link_enter_failed(link);
                                        return;
                                }
                        }

                        break;
                case DHCP_EVENT_RENEW:
                        r = dhcp_lease_renew(client, link);
                        if (r < 0) {
                                link_enter_failed(link);
                                return;
                        }
                        break;
                case DHCP_EVENT_IP_ACQUIRE:
                        r = dhcp_lease_acquired(client, link);
                        if (r < 0) {
                                link_enter_failed(link);
                                return;
                        }
                        break;
                default:
                        if (event < 0)
                                log_warning_link(link,
                                                 "DHCP error: client failed: %s",
                                                 strerror(-event));
                        else
                                log_warning_link(link,
                                                 "DHCP unknown event: %d",
                                                 event);
                        break;
        }

        return;
}

int dhcp4_configure(Link *link) {
        int r;

        assert(link);
        assert(link->network);
        assert(IN_SET(link->network->dhcp, DHCP_SUPPORT_BOTH, DHCP_SUPPORT_V4));

        r = sd_dhcp_client_new(&link->dhcp_client);
        if (r < 0)
                return r;

        r = sd_dhcp_client_attach_event(link->dhcp_client, NULL, 0);
        if (r < 0)
                return r;

        r = sd_dhcp_client_set_mac(link->dhcp_client, &link->mac);
        if (r < 0)
                return r;

        r = sd_dhcp_client_set_index(link->dhcp_client, link->ifindex);
        if (r < 0)
                return r;

        r = sd_dhcp_client_set_callback(link->dhcp_client, dhcp4_handler, link);
        if (r < 0)
                return r;

        r = sd_dhcp_client_set_request_broadcast(link->dhcp_client,
                                                 link->network->dhcp_broadcast);
        if (r < 0)
                return r;

        if (link->mtu) {
                r = sd_dhcp_client_set_mtu(link->dhcp_client, link->mtu);
                if (r < 0)
                        return r;
        }

        if (link->network->dhcp_mtu) {
             r = sd_dhcp_client_set_request_option(link->dhcp_client,
                                                   DHCP_OPTION_INTERFACE_MTU);
             if (r < 0)
                return r;
        }

        if (link->network->dhcp_routes) {
                r = sd_dhcp_client_set_request_option(link->dhcp_client,
                                                      DHCP_OPTION_STATIC_ROUTE);
                if (r < 0)
                        return r;
                r = sd_dhcp_client_set_request_option(link->dhcp_client,
                                                      DHCP_OPTION_CLASSLESS_STATIC_ROUTE);
                        if (r < 0)
                                return r;
        }

        if (link->network->dhcp_sendhost) {
                _cleanup_free_ char *hostname = NULL;

                hostname = gethostname_malloc();
                if (!hostname)
                        return -ENOMEM;

                if (!is_localhost(hostname)) {
                        r = sd_dhcp_client_set_hostname(link->dhcp_client,
                                                        hostname);
                        if (r < 0)
                                return r;
                }
        }

        if (link->network->dhcp_vendor_class_identifier) {
                r = sd_dhcp_client_set_vendor_class_identifier(link->dhcp_client,
                                                               link->network->dhcp_vendor_class_identifier);
                if (r < 0)
                        return r;
        }

        return 0;
}