summaryrefslogtreecommitdiffstats
path: root/src/libsystemd/sd-netlink/netlink-util.c
blob: 832159a649822d2f1cc4fd4b19d396b0ce717085 (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
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
/* SPDX-License-Identifier: LGPL-2.1-or-later */

#include "sd-netlink.h"

#include "fd-util.h"
#include "iovec-util.h"
#include "memory-util.h"
#include "netlink-internal.h"
#include "netlink-util.h"
#include "parse-util.h"
#include "process-util.h"
#include "strv.h"

static int set_link_name(sd_netlink **rtnl, int ifindex, const char *name) {
        _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *message = NULL;
        int r;

        assert(rtnl);
        assert(ifindex > 0);
        assert(name);

        /* Assign the requested name. */
        r = sd_rtnl_message_new_link(*rtnl, &message, RTM_SETLINK, ifindex);
        if (r < 0)
                return r;

        r = sd_netlink_message_append_string(message, IFLA_IFNAME, name);
        if (r < 0)
                return r;

        return sd_netlink_call(*rtnl, message, 0, NULL);
}

int rtnl_set_link_name(sd_netlink **rtnl, int ifindex, const char *name, char* const *alternative_names) {
        _cleanup_strv_free_ char **original_altnames = NULL, **new_altnames = NULL;
        bool altname_deleted = false;
        int r;

        assert(rtnl);
        assert(ifindex > 0);

        if (isempty(name) && strv_isempty(alternative_names))
                return 0;

        if (name && !ifname_valid(name))
                return -EINVAL;

        /* If the requested name is already assigned as an alternative name, then first drop it. */
        r = rtnl_get_link_alternative_names(rtnl, ifindex, &original_altnames);
        if (r < 0)
                log_debug_errno(r, "Failed to get alternative names on network interface %i, ignoring: %m",
                                ifindex);

        if (name) {
                if (strv_contains(original_altnames, name)) {
                        r = rtnl_delete_link_alternative_names(rtnl, ifindex, STRV_MAKE(name));
                        if (r < 0)
                                return log_debug_errno(r, "Failed to remove '%s' from alternative names on network interface %i: %m",
                                                       name, ifindex);

                        altname_deleted = true;
                }

                r = set_link_name(rtnl, ifindex, name);
                if (r < 0)
                        goto fail;
        }

        /* Filter out already assigned names from requested alternative names. Also, dedup the request. */
        STRV_FOREACH(a, alternative_names) {
                if (streq_ptr(name, *a))
                        continue;

                if (strv_contains(original_altnames, *a))
                        continue;

                if (strv_contains(new_altnames, *a))
                        continue;

                if (!ifname_valid_full(*a, IFNAME_VALID_ALTERNATIVE))
                        continue;

                r = strv_extend(&new_altnames, *a);
                if (r < 0)
                        return r;
        }

        strv_sort(new_altnames);

        /* Finally, assign alternative names. */
        r = rtnl_set_link_alternative_names(rtnl, ifindex, new_altnames);
        if (r == -EEXIST) /* Already assigned to another interface? */
                STRV_FOREACH(a, new_altnames) {
                        r = rtnl_set_link_alternative_names(rtnl, ifindex, STRV_MAKE(*a));
                        if (r < 0)
                                log_debug_errno(r, "Failed to assign '%s' as an alternative name on network interface %i, ignoring: %m",
                                                *a, ifindex);
                }
        else if (r < 0)
                log_debug_errno(r, "Failed to assign alternative names on network interface %i, ignoring: %m", ifindex);

        return 0;

fail:
        if (altname_deleted) {
                int q = rtnl_set_link_alternative_names(rtnl, ifindex, STRV_MAKE(name));
                if (q < 0)
                        log_debug_errno(q, "Failed to restore '%s' as an alternative name on network interface %i, ignoring: %m",
                                        name, ifindex);
        }

        return r;
}

int rtnl_set_link_properties(
                sd_netlink **rtnl,
                int ifindex,
                const char *alias,
                const struct hw_addr_data *hw_addr,
                uint32_t txqueues,
                uint32_t rxqueues,
                uint32_t txqueuelen,
                uint32_t mtu,
                uint32_t gso_max_size,
                size_t gso_max_segments) {
        _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *message = NULL;
        int r;

        assert(rtnl);
        assert(ifindex > 0);

        if (!alias &&
            (!hw_addr || hw_addr->length == 0) &&
            txqueues == 0 &&
            rxqueues == 0 &&
            txqueuelen == UINT32_MAX &&
            mtu == 0 &&
            gso_max_size == 0 &&
            gso_max_segments == 0)
                return 0;

        if (!*rtnl) {
                r = sd_netlink_open(rtnl);
                if (r < 0)
                        return r;
        }

        r = sd_rtnl_message_new_link(*rtnl, &message, RTM_SETLINK, ifindex);
        if (r < 0)
                return r;

        if (alias) {
                r = sd_netlink_message_append_string(message, IFLA_IFALIAS, alias);
                if (r < 0)
                        return r;
        }

        if (hw_addr && hw_addr->length > 0) {
                r = netlink_message_append_hw_addr(message, IFLA_ADDRESS, hw_addr);
                if (r < 0)
                        return r;
        }

        if (txqueues > 0) {
                r = sd_netlink_message_append_u32(message, IFLA_NUM_TX_QUEUES, txqueues);
                if (r < 0)
                        return r;
        }

        if (rxqueues > 0) {
                r = sd_netlink_message_append_u32(message, IFLA_NUM_RX_QUEUES, rxqueues);
                if (r < 0)
                        return r;
        }

        if (txqueuelen < UINT32_MAX) {
                r = sd_netlink_message_append_u32(message, IFLA_TXQLEN, txqueuelen);
                if (r < 0)
                        return r;
        }

        if (mtu != 0) {
                r = sd_netlink_message_append_u32(message, IFLA_MTU, mtu);
                if (r < 0)
                        return r;
        }

        if (gso_max_size > 0) {
                r = sd_netlink_message_append_u32(message, IFLA_GSO_MAX_SIZE, gso_max_size);
                if (r < 0)
                        return r;
        }

        if (gso_max_segments > 0) {
                r = sd_netlink_message_append_u32(message, IFLA_GSO_MAX_SEGS, gso_max_segments);
                if (r < 0)
                        return r;
        }

        r = sd_netlink_call(*rtnl, message, 0, NULL);
        if (r < 0)
                return r;

        return 0;
}

int rtnl_get_link_alternative_names(sd_netlink **rtnl, int ifindex, char ***ret) {
        _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *message = NULL, *reply = NULL;
        _cleanup_strv_free_ char **names = NULL;
        int r;

        assert(rtnl);
        assert(ifindex > 0);
        assert(ret);

        if (!*rtnl) {
                r = sd_netlink_open(rtnl);
                if (r < 0)
                        return r;
        }

        r = sd_rtnl_message_new_link(*rtnl, &message, RTM_GETLINK, ifindex);
        if (r < 0)
                return r;

        r = sd_netlink_call(*rtnl, message, 0, &reply);
        if (r < 0)
                return r;

        r = sd_netlink_message_read_strv(reply, IFLA_PROP_LIST, IFLA_ALT_IFNAME, &names);
        if (r < 0 && r != -ENODATA)
                return r;

        *ret = TAKE_PTR(names);

        return 0;
}

static int rtnl_update_link_alternative_names(
                sd_netlink **rtnl,
                uint16_t nlmsg_type,
                int ifindex,
                char* const *alternative_names) {

        _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *message = NULL;
        int r;

        assert(rtnl);
        assert(ifindex > 0);
        assert(IN_SET(nlmsg_type, RTM_NEWLINKPROP, RTM_DELLINKPROP));

        if (strv_isempty(alternative_names))
                return 0;

        if (!*rtnl) {
                r = sd_netlink_open(rtnl);
                if (r < 0)
                        return r;
        }

        r = sd_rtnl_message_new_link(*rtnl, &message, nlmsg_type, ifindex);
        if (r < 0)
                return r;

        r = sd_netlink_message_open_container(message, IFLA_PROP_LIST);
        if (r < 0)
                return r;

        r = sd_netlink_message_append_strv(message, IFLA_ALT_IFNAME, (const char**) alternative_names);
        if (r < 0)
                return r;

        r = sd_netlink_message_close_container(message);
        if (r < 0)
                return r;

        r = sd_netlink_call(*rtnl, message, 0, NULL);
        if (r < 0)
                return r;

        return 0;
}

int rtnl_set_link_alternative_names(sd_netlink **rtnl, int ifindex, char* const *alternative_names) {
        return rtnl_update_link_alternative_names(rtnl, RTM_NEWLINKPROP, ifindex, alternative_names);
}

int rtnl_delete_link_alternative_names(sd_netlink **rtnl, int ifindex, char* const *alternative_names) {
        return rtnl_update_link_alternative_names(rtnl, RTM_DELLINKPROP, ifindex, alternative_names);
}

int rtnl_set_link_alternative_names_by_ifname(
                sd_netlink **rtnl,
                const char *ifname,
                char* const *alternative_names) {

        _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *message = NULL;
        int r;

        assert(rtnl);
        assert(ifname);

        if (strv_isempty(alternative_names))
                return 0;

        if (!*rtnl) {
                r = sd_netlink_open(rtnl);
                if (r < 0)
                        return r;
        }

        r = sd_rtnl_message_new_link(*rtnl, &message, RTM_NEWLINKPROP, 0);
        if (r < 0)
                return r;

        r = sd_netlink_message_append_string(message, IFLA_IFNAME, ifname);
        if (r < 0)
                return r;

        r = sd_netlink_message_open_container(message, IFLA_PROP_LIST);
        if (r < 0)
                return r;

        r = sd_netlink_message_append_strv(message, IFLA_ALT_IFNAME, (const char**) alternative_names);
        if (r < 0)
                return r;

        r = sd_netlink_message_close_container(message);
        if (r < 0)
                return r;

        r = sd_netlink_call(*rtnl, message, 0, NULL);
        if (r < 0)
                return r;

        return 0;
}

int rtnl_resolve_link_alternative_name(sd_netlink **rtnl, const char *name, char **ret) {
        _cleanup_(sd_netlink_unrefp) sd_netlink *our_rtnl = NULL;
        _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *message = NULL, *reply = NULL;
        int r, ifindex;

        assert(name);

        /* This returns ifindex and the main interface name. */

        if (!ifname_valid_full(name, IFNAME_VALID_ALTERNATIVE))
                return -EINVAL;

        if (!rtnl)
                rtnl = &our_rtnl;
        if (!*rtnl) {
                r = sd_netlink_open(rtnl);
                if (r < 0)
                        return r;
        }

        r = sd_rtnl_message_new_link(*rtnl, &message, RTM_GETLINK, 0);
        if (r < 0)
                return r;

        r = sd_netlink_message_append_string(message, IFLA_ALT_IFNAME, name);
        if (r < 0)
                return r;

        r = sd_netlink_call(*rtnl, message, 0, &reply);
        if (r == -EINVAL)
                return -ENODEV; /* The device doesn't exist */
        if (r < 0)
                return r;

        r = sd_rtnl_message_link_get_ifindex(reply, &ifindex);
        if (r < 0)
                return r;
        assert(ifindex > 0);

        if (ret) {
                r = sd_netlink_message_read_string_strdup(reply, IFLA_IFNAME, ret);
                if (r < 0)
                        return r;
        }

        return ifindex;
}

int rtnl_resolve_ifname(sd_netlink **rtnl, const char *name) {
        int r;

        /* Like if_nametoindex, but resolves "alternative names" too. */

        assert(name);

        r = if_nametoindex(name);
        if (r > 0)
                return r;

        return rtnl_resolve_link_alternative_name(rtnl, name, NULL);
}

int rtnl_resolve_interface(sd_netlink **rtnl, const char *name) {
        int r;

        /* Like rtnl_resolve_ifname, but resolves interface numbers too. */

        assert(name);

        r = parse_ifindex(name);
        if (r > 0)
                return r;
        assert(r < 0);

        return rtnl_resolve_ifname(rtnl, name);
}

int rtnl_resolve_interface_or_warn(sd_netlink **rtnl, const char *name) {
        int r;

        r = rtnl_resolve_interface(rtnl, name);
        if (r < 0)
                return log_error_errno(r, "Failed to resolve interface \"%s\": %m", name);
        return r;
}

int rtnl_get_link_info(
                sd_netlink **rtnl,
                int ifindex,
                unsigned short *ret_iftype,
                unsigned *ret_flags,
                char **ret_kind,
                struct hw_addr_data *ret_hw_addr,
                struct hw_addr_data *ret_permanent_hw_addr) {

        _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *message = NULL, *reply = NULL;
        struct hw_addr_data addr = HW_ADDR_NULL, perm_addr = HW_ADDR_NULL;
        _cleanup_free_ char *kind = NULL;
        unsigned short iftype;
        unsigned flags;
        int r;

        assert(rtnl);
        assert(ifindex > 0);

        if (!ret_iftype && !ret_flags)
                return 0;

        if (!*rtnl) {
                r = sd_netlink_open(rtnl);
                if (r < 0)
                        return r;
        }

        r = sd_rtnl_message_new_link(*rtnl, &message, RTM_GETLINK, ifindex);
        if (r < 0)
                return r;

        r = sd_netlink_call(*rtnl, message, 0, &reply);
        if (r == -EINVAL)
                return -ENODEV; /* The device does not exist */
        if (r < 0)
                return r;

        if (ret_iftype) {
                r = sd_rtnl_message_link_get_type(reply, &iftype);
                if (r < 0)
                        return r;
        }

        if (ret_flags) {
                r = sd_rtnl_message_link_get_flags(reply, &flags);
                if (r < 0)
                        return r;
        }

        if (ret_kind) {
                r = sd_netlink_message_enter_container(reply, IFLA_LINKINFO);
                if (r >= 0) {
                        r = sd_netlink_message_read_string_strdup(reply, IFLA_INFO_KIND, &kind);
                        if (r < 0 && r != -ENODATA)
                                return r;

                        r = sd_netlink_message_exit_container(reply);
                        if (r < 0)
                                return r;
                }
        }

        if (ret_hw_addr) {
                r = netlink_message_read_hw_addr(reply, IFLA_ADDRESS, &addr);
                if (r < 0 && r != -ENODATA)
                        return r;
        }

        if (ret_permanent_hw_addr) {
                r = netlink_message_read_hw_addr(reply, IFLA_PERM_ADDRESS, &perm_addr);
                if (r < 0 && r != -ENODATA)
                        return r;
        }

        if (ret_iftype)
                *ret_iftype = iftype;
        if (ret_flags)
                *ret_flags = flags;
        if (ret_kind)
                *ret_kind = TAKE_PTR(kind);
        if (ret_hw_addr)
                *ret_hw_addr = addr;
        if (ret_permanent_hw_addr)
                *ret_permanent_hw_addr = perm_addr;
        return 0;
}

int rtnl_log_parse_error(int r) {
        return log_error_errno(r, "Failed to parse netlink message: %m");
}

int rtnl_log_create_error(int r) {
        return log_error_errno(r, "Failed to create netlink message: %m");
}

void rtattr_append_attribute_internal(struct rtattr *rta, unsigned short type, const void *data, size_t data_length) {
        size_t padding_length;
        uint8_t *padding;

        assert(rta);
        assert(!data || data_length > 0);

        /* fill in the attribute */
        rta->rta_type = type;
        rta->rta_len = RTA_LENGTH(data_length);
        if (data)
                /* we don't deal with the case where the user lies about the type
                 * and gives us too little data (so don't do that)
                 */
                padding = mempcpy(RTA_DATA(rta), data, data_length);

        else
                /* if no data was passed, make sure we still initialize the padding
                   note that we can have data_length > 0 (used by some containers) */
                padding = RTA_DATA(rta);

        /* make sure also the padding at the end of the message is initialized */
        padding_length = (uint8_t *) rta + RTA_SPACE(data_length) - padding;
        memzero(padding, padding_length);
}

int rtattr_append_attribute(struct rtattr **rta, unsigned short type, const void *data, size_t data_length) {
        struct rtattr *new_rta, *sub_rta;
        size_t message_length;

        assert(rta);
        assert(!data || data_length > 0);

        /* get the new message size (with padding at the end) */
        message_length = RTA_ALIGN(rta ? (*rta)->rta_len : 0) + RTA_SPACE(data_length);

        /* buffer should be smaller than both one page or 8K to be accepted by the kernel */
        if (message_length > MIN(page_size(), 8192UL))
                return -ENOBUFS;

        /* realloc to fit the new attribute */
        new_rta = realloc(*rta, message_length);
        if (!new_rta)
                return -ENOMEM;
        *rta = new_rta;

        /* get pointer to the attribute we are about to add */
        sub_rta = (struct rtattr *) ((uint8_t *) *rta + RTA_ALIGN((*rta)->rta_len));

        rtattr_append_attribute_internal(sub_rta, type, data, data_length);

        /* update rta_len */
        (*rta)->rta_len = message_length;

        return 0;
}

MultipathRoute *multipath_route_free(MultipathRoute *m) {
        if (!m)
                return NULL;

        free(m->ifname);

        return mfree(m);
}

int multipath_route_dup(const MultipathRoute *m, MultipathRoute **ret) {
        _cleanup_(multipath_route_freep) MultipathRoute *n = NULL;
        _cleanup_free_ char *ifname = NULL;

        assert(m);
        assert(ret);

        if (m->ifname) {
                ifname = strdup(m->ifname);
                if (!ifname)
                        return -ENOMEM;
        }

        n = new(MultipathRoute, 1);
        if (!n)
                return -ENOMEM;

        *n = (MultipathRoute) {
                .gateway = m->gateway,
                .weight = m->weight,
                .ifindex = m->ifindex,
                .ifname = TAKE_PTR(ifname),
        };

        *ret = TAKE_PTR(n);

        return 0;
}

int rtattr_read_nexthop(const struct rtnexthop *rtnh, size_t size, int family, OrderedSet **ret) {
        _cleanup_ordered_set_free_free_ OrderedSet *set = NULL;
        int r;

        assert(rtnh);
        assert(IN_SET(family, AF_INET, AF_INET6));

        if (size < sizeof(struct rtnexthop))
                return -EBADMSG;

        for (; size >= sizeof(struct rtnexthop); ) {
                _cleanup_(multipath_route_freep) MultipathRoute *m = NULL;

                if (NLMSG_ALIGN(rtnh->rtnh_len) > size)
                        return -EBADMSG;

                if (rtnh->rtnh_len < sizeof(struct rtnexthop))
                        return -EBADMSG;

                m = new(MultipathRoute, 1);
                if (!m)
                        return -ENOMEM;

                *m = (MultipathRoute) {
                        .ifindex = rtnh->rtnh_ifindex,
                        .weight = rtnh->rtnh_hops,
                };

                if (rtnh->rtnh_len > sizeof(struct rtnexthop)) {
                        size_t len = rtnh->rtnh_len - sizeof(struct rtnexthop);

                        for (struct rtattr *attr = RTNH_DATA(rtnh); RTA_OK(attr, len); attr = RTA_NEXT(attr, len)) {
                                if (attr->rta_type == RTA_GATEWAY) {
                                        if (attr->rta_len != RTA_LENGTH(FAMILY_ADDRESS_SIZE(family)))
                                                return -EBADMSG;

                                        m->gateway.family = family;
                                        memcpy(&m->gateway.address, RTA_DATA(attr), FAMILY_ADDRESS_SIZE(family));
                                        break;
                                } else if (attr->rta_type == RTA_VIA) {
                                        uint16_t gw_family;

                                        if (family != AF_INET)
                                                return -EINVAL;

                                        if (attr->rta_len < RTA_LENGTH(sizeof(uint16_t)))
                                                return -EBADMSG;

                                        gw_family = *(uint16_t *) RTA_DATA(attr);

                                        if (gw_family != AF_INET6)
                                                return -EBADMSG;

                                        if (attr->rta_len != RTA_LENGTH(FAMILY_ADDRESS_SIZE(gw_family) + sizeof(gw_family)))
                                                return -EBADMSG;

                                        memcpy(&m->gateway, RTA_DATA(attr), FAMILY_ADDRESS_SIZE(gw_family) + sizeof(gw_family));
                                        break;
                                }
                        }
                }

                r = ordered_set_ensure_put(&set, NULL, m);
                if (r < 0)
                        return r;

                TAKE_PTR(m);

                size -= NLMSG_ALIGN(rtnh->rtnh_len);
                rtnh = RTNH_NEXT(rtnh);
        }

        if (ret)
                *ret = TAKE_PTR(set);
        return 0;
}

bool netlink_pid_changed(sd_netlink *nl) {
        /* We don't support people creating an nl connection and
         * keeping it around over a fork(). Let's complain. */
        return ASSERT_PTR(nl)->original_pid != getpid_cached();
}

static int socket_open(int family) {
        int fd;

        fd = socket(AF_NETLINK, SOCK_RAW|SOCK_CLOEXEC|SOCK_NONBLOCK, family);
        if (fd < 0)
                return -errno;

        return fd_move_above_stdio(fd);
}

int netlink_open_family(sd_netlink **ret, int family) {
        _cleanup_close_ int fd = -EBADF;
        int r;

        fd = socket_open(family);
        if (fd < 0)
                return fd;

        r = sd_netlink_open_fd(ret, fd);
        if (r < 0)
                return r;
        TAKE_FD(fd);

        return 0;
}

static bool serial_used(sd_netlink *nl, uint32_t serial) {
        assert(nl);

        return
                hashmap_contains(nl->reply_callbacks, UINT32_TO_PTR(serial)) ||
                hashmap_contains(nl->rqueue_by_serial, UINT32_TO_PTR(serial)) ||
                hashmap_contains(nl->rqueue_partial_by_serial, UINT32_TO_PTR(serial));
}

void netlink_seal_message(sd_netlink *nl, sd_netlink_message *m) {
        uint32_t picked;

        assert(nl);
        assert(!netlink_pid_changed(nl));
        assert(m);
        assert(m->hdr);

        /* Avoid collisions with outstanding requests */
        do {
                picked = nl->serial;

                /* Don't use seq == 0, as that is used for broadcasts, so we would get confused by replies to
                   such messages */
                nl->serial = nl->serial == UINT32_MAX ? 1 : nl->serial + 1;

        } while (serial_used(nl, picked));

        m->hdr->nlmsg_seq = picked;
        message_seal(m);
}

static int socket_writev_message(sd_netlink *nl, sd_netlink_message **m, size_t msgcount) {
        _cleanup_free_ struct iovec *iovs = NULL;
        ssize_t k;

        assert(nl);
        assert(m);
        assert(msgcount > 0);

        iovs = new(struct iovec, msgcount);
        if (!iovs)
                return -ENOMEM;

        for (size_t i = 0; i < msgcount; i++) {
                assert(m[i]->hdr);
                assert(m[i]->hdr->nlmsg_len > 0);

                iovs[i] = IOVEC_MAKE(m[i]->hdr, m[i]->hdr->nlmsg_len);
        }

        k = writev(nl->fd, iovs, msgcount);
        if (k < 0)
                return -errno;

        return k;
}

int sd_netlink_sendv(
                sd_netlink *nl,
                sd_netlink_message **messages,
                size_t msgcount,
                uint32_t **ret_serial) {

        _cleanup_free_ uint32_t *serials = NULL;
        int r;

        assert_return(nl, -EINVAL);
        assert_return(!netlink_pid_changed(nl), -ECHILD);
        assert_return(messages, -EINVAL);
        assert_return(msgcount > 0, -EINVAL);

        if (ret_serial) {
                serials = new(uint32_t, msgcount);
                if (!serials)
                        return -ENOMEM;
        }

        for (size_t i = 0; i < msgcount; i++) {
                assert_return(!messages[i]->sealed, -EPERM);

                netlink_seal_message(nl, messages[i]);
                if (serials)
                        serials[i] = message_get_serial(messages[i]);
        }

        r = socket_writev_message(nl, messages, msgcount);
        if (r < 0)
                return r;

        if (ret_serial)
                *ret_serial = TAKE_PTR(serials);

        return r;
}