summaryrefslogtreecommitdiff
path: root/src/libsystemd-network/sd-lldp.c
blob: 6a2c05185dbf277c2517c2b0d8ac61c3d4febb7d (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
/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/

/***
    This file is part of systemd.

    Copyright (C) 2014 Tom Gundersen
    Copyright (C) 2014 Susant Sahani

    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 <arpa/inet.h>

#include "siphash24.h"
#include "hashmap.h"

#include "lldp-tlv.h"
#include "lldp-port.h"
#include "sd-lldp.h"
#include "prioq.h"
#include "lldp-internal.h"
#include "lldp-util.h"

typedef enum LLDPAgentRXState {
        LLDP_AGENT_RX_WAIT_PORT_OPERATIONAL = 4,
        LLDP_AGENT_RX_DELETE_AGED_INFO,
        LLDP_AGENT_RX_LLDP_INITIALIZE,
        LLDP_AGENT_RX_WAIT_FOR_FRAME,
        LLDP_AGENT_RX_RX_FRAME,
        LLDP_AGENT_RX_DELETE_INFO,
        LLDP_AGENT_RX_UPDATE_INFO,
        _LLDP_AGENT_RX_STATE_MAX,
        _LLDP_AGENT_RX_INVALID = -1,
} LLDPAgentRXState;

/* Section 10.5.2.2 Reception counters */
struct lldp_agent_statistics {
        uint64_t stats_ageouts_total;
        uint64_t stats_frames_discarded_total;
        uint64_t stats_frames_in_errors_total;
        uint64_t stats_frames_in_total;
        uint64_t stats_tlvs_discarded_total;
        uint64_t stats_tlvs_unrecognized_total;
};

struct sd_lldp {
        lldp_port *port;

        Prioq *by_expiry;
        Hashmap *neighbour_mib;

        sd_lldp_cb_t cb;

        void *userdata;

        LLDPAgentRXState rx_state;
        lldp_agent_statistics statistics;
};

static unsigned long chassis_id_hash_func(const void *p,
                                          const uint8_t hash_key[HASH_KEY_SIZE]) {
        uint64_t u;
        const lldp_chassis_id *id = p;

        assert(id);

        siphash24((uint8_t *) &u, id->data, id->length, hash_key);

        return (unsigned long) u;
}

static int chassis_id_compare_func(const void *_a, const void *_b) {
        const lldp_chassis_id *a, *b;

        a = _a;
        b = _b;

        assert(!a->length || a->data);
        assert(!b->length || b->data);

        if (a->type != b->type)
                return -1;

        if (a->length != b->length)
                return a->length < b->length ? -1 : 1;

        return memcmp(a->data, b->data, a->length);
}

static const struct hash_ops chassis_id_hash_ops = {
        .hash = chassis_id_hash_func,
        .compare = chassis_id_compare_func
};

static void lldp_mib_delete_objects(sd_lldp *lldp);
static void lldp_set_state(sd_lldp *lldp, LLDPAgentRXState state);
static void lldp_run_state_machine(sd_lldp *ll);

static int lldp_receive_frame(sd_lldp *lldp, tlv_packet *tlv) {
        int r;

        assert(lldp);
        assert(tlv);

        /* Remove expired packets */
        if (prioq_size(lldp->by_expiry) > 0) {

                lldp_set_state(lldp, LLDP_AGENT_RX_DELETE_INFO);

                lldp_mib_delete_objects(lldp);
        }

        r = lldp_mib_add_objects(lldp->by_expiry, lldp->neighbour_mib, tlv);
        if (r < 0)
                goto out;

        lldp_set_state(lldp, LLDP_AGENT_RX_UPDATE_INFO);

        log_lldp("Packet added. MIB size: %d , PQ size: %d",
                 hashmap_size(lldp->neighbour_mib),
                 prioq_size(lldp->by_expiry));

        lldp->statistics.stats_frames_in_total ++;

 out:
        if (r < 0)
                log_lldp("Receive frame failed: %s", strerror(-r));

        lldp_set_state(lldp, LLDP_AGENT_RX_WAIT_FOR_FRAME);

        return 0;
}

/* 10.3.2 LLDPDU validation: rxProcessFrame() */
int lldp_handle_packet(tlv_packet *tlv, uint16_t length) {
        uint16_t type, len, i, l, t;
        bool chassis_id = false;
        bool malformed = false;
        bool port_id = false;
        bool ttl = false;
        bool end = false;
        lldp_port *port;
        uint8_t *p, *q;
        sd_lldp *lldp;
        int r;

        assert(tlv);
        assert(length > 0);

        port = (lldp_port *) tlv->userdata;
        lldp = (sd_lldp *) port->userdata;

        if (lldp->port->status == LLDP_PORT_STATUS_DISABLED) {
                log_lldp("Port is disabled : %s . Dropping ...",
                         lldp->port->ifname);
                goto out;
        }

        lldp_set_state(lldp, LLDP_AGENT_RX_RX_FRAME);

        p = tlv->pdu;
        p += sizeof(struct ether_header);

        for (i = 1, l = 0; l <= length; i++) {

                memcpy(&t, p, sizeof(uint16_t));

                type = ntohs(t) >> 9;
                len = ntohs(t) & 0x01ff;

                if (type == LLDP_TYPE_END) {
                        if (len != 0) {
                                log_lldp("TLV type end is not length 0. Length:%d received . Dropping ...",
                                         len);

                                malformed = true;
                                goto out;
                        }

                        end = true;

                        break;
                } else if (type >=_LLDP_TYPE_MAX) {
                        log_lldp("TLV type not recognized %d . Dropping ...",
                                 type);

                        malformed = true;
                        goto out;
                }

                /* skip type and lengh encoding */
                p += 2;
                q = p;

                p += len;
                l += (len + 2);

                if (i <= 3) {
                        if (i != type) {
                                log_lldp("TLV missing or out of order. Dropping ...");

                                malformed = true;
                                goto out;
                        }
                }

                switch(type) {
                case LLDP_TYPE_CHASSIS_ID:

                        if (len < 2) {
                                log_lldp("Received malformed Chassis ID TLV len = %d. Dropping",
                                         len);

                                malformed = true;
                                goto out;
                        }

                        if (chassis_id) {
                                log_lldp("Duplicate Chassis ID TLV found. Dropping ...");

                                malformed = true;
                                goto out;
                        }

                        /* Look what subtype it has */
                        if (*q == LLDP_CHASSIS_SUBTYPE_RESERVED ||
                            *q > LLDP_CHASSIS_SUBTYPE_LOCALLY_ASSIGNED) {
                                log_lldp("Unknown subtype: %d found in Chassis ID TLV . Dropping ...",
                                         *q);

                                malformed = true;
                                goto out;

                        }

                        chassis_id = true;

                        break;
                case LLDP_TYPE_PORT_ID:

                        if (len < 2) {
                                log_lldp("Received malformed Port ID TLV len = %d. Dropping",
                                         len);

                                malformed = true;
                                goto out;
                        }

                        if (port_id) {
                                log_lldp("Duplicate Port ID TLV found. Dropping ...");

                                malformed = true;
                                goto out;
                        }

                        /* Look what subtype it has */
                        if (*q == LLDP_PORT_SUBTYPE_RESERVED ||
                            *q > LLDP_PORT_SUBTYPE_LOCALLY_ASSIGNED) {
                                log_lldp("Unknown subtype: %d found in Port ID TLV . Dropping ...",
                                         *q);

                                malformed = true;
                                goto out;

                        }

                        port_id = true;

                        break;
                case LLDP_TYPE_TTL:

                        if(len != 2) {
                                log_lldp(
                                         "Received invalid lenth: %d TTL TLV. Dropping ...",
                                         len);

                                malformed = true;
                                goto out;
                        }

                        if (ttl) {
                                log_lldp("Duplicate TTL TLV found. Dropping ...");

                                malformed = true;
                                goto out;
                        }

                        ttl = true;

                        break;
                default:

                        if (len == 0) {
                                log_lldp("TLV type = %d's, length 0 received . Dropping ...",
                                         type);

                                malformed = true;
                                goto out;
                        }
                        break;
                }
        }

        if(!chassis_id || !port_id || !ttl || !end) {
                log_lldp( "One or more mandotory TLV missing . Dropping ...");

                malformed = true;
                goto out;

        }

        r = tlv_packet_parse_pdu(tlv, length);
        if (r < 0) {
                log_lldp( "Failed to parse the TLV. Dropping ...");

                malformed = true;
                goto out;
        }

        return lldp_receive_frame(lldp, tlv);

 out:
        lldp_set_state(lldp, LLDP_AGENT_RX_WAIT_FOR_FRAME);

        if (malformed) {
                lldp->statistics.stats_frames_discarded_total ++;
                lldp->statistics.stats_frames_in_errors_total ++;
        }

        tlv_packet_free(tlv);

        return 0;
}

static int ttl_expiry_item_prioq_compare_func(const void *a, const void *b) {
        const lldp_neighbour_port *p = a, *q = b;

        if (p->until < q->until)
                return -1;

        if (p->until > q->until)
                return 1;

        return 0;
}

static void lldp_set_state(sd_lldp *lldp, LLDPAgentRXState state) {

        assert(lldp);
        assert(state < _LLDP_AGENT_RX_STATE_MAX);

        lldp->rx_state = state;

        lldp_run_state_machine(lldp);
}

static void lldp_run_state_machine(sd_lldp *lldp) {

        if (lldp->rx_state == LLDP_AGENT_RX_UPDATE_INFO)
                if (lldp->cb)
                        lldp->cb(lldp, LLDP_AGENT_RX_UPDATE_INFO, lldp->userdata);
}

/* 10.5.5.2.1 mibDeleteObjects ()
 * The mibDeleteObjects () procedure deletes all information in the LLDP remote
 * systems MIB associated with the MSAP identifier if an LLDPDU is received with
 * an rxTTL value of zero (see 10.3.2) or the timing counter rxInfoTTL expires. */

static void lldp_mib_delete_objects(sd_lldp *lldp) {
        lldp_neighbour_port *p;
        usec_t t = 0;

        /* Remove all entries that are past their TTL */
        for (;;) {

                if (prioq_size(lldp->by_expiry) <= 0)
                        break;

                p = prioq_peek(lldp->by_expiry);
                if (!p)
                        break;

                if (t <= 0)
                        t = now(CLOCK_BOOTTIME);

                if (p->until > t)
                        break;

                lldp_neighbour_port_remove_and_free(p);

                lldp->statistics.stats_ageouts_total ++;
        }
}

static void lldp_mib_objects_flush(sd_lldp *lldp) {
        lldp_neighbour_port *p, *q;
        lldp_chassis *c;

        assert(lldp);
        assert(lldp->neighbour_mib);
        assert(lldp->by_expiry);

        /* Drop all packets */
        while ((c = hashmap_steal_first(lldp->neighbour_mib))) {

                LIST_FOREACH_SAFE(port, p, q, c->ports) {
                        lldp_neighbour_port_remove_and_free(p);
                }
        }

        assert(hashmap_size(lldp->neighbour_mib) == 0);
        assert(prioq_size(lldp->by_expiry) == 0);
}

int sd_lldp_save(sd_lldp *lldp, const char *lldp_file) {
        _cleanup_free_ char *temp_path = NULL;
        _cleanup_fclose_ FILE *f = NULL;
        uint8_t *mac, *port_id, type;
        lldp_neighbour_port *p;
        uint16_t data = 0, length = 0;
        char buf[LINE_MAX];
        lldp_chassis *c;
        usec_t time;
        Iterator i;
        int r;

        assert(lldp);
        assert(lldp_file);

        r = fopen_temporary(lldp_file, &f, &temp_path);
        if (r < 0)
                goto finish;

        fchmod(fileno(f), 0644);

        HASHMAP_FOREACH(c, lldp->neighbour_mib, i) {
                LIST_FOREACH(port, p, c->ports) {
                        _cleanup_free_ char *s = NULL;
                        char *k, *t;

                        r = lldp_read_chassis_id(p->packet, &type, &length, &mac);
                        if (r < 0)
                                continue;

                        sprintf(buf, "'_Chassis=%02x:%02x:%02x:%02x:%02x:%02x' '_CType=%d' ",
                                mac[0], mac[1], mac[2], mac[3], mac[4], mac[5], type);

                        s = strdup(buf);
                        if (!s)
                                return -ENOMEM;

                        r = lldp_read_port_id(p->packet, &type, &length, &port_id);
                        if (r < 0)
                                continue;

                        if (type != LLDP_PORT_SUBTYPE_MAC_ADDRESS) {
                                k = strndup((char *) port_id, length -1);
                                if (!k)
                                        return -ENOMEM;

                                sprintf(buf, "'_Port=%s' '_PType=%d' ", k , type);
                                free(k);
                        } else {
                                mac = port_id;
                                sprintf(buf, "'_Port=%02x:%02x:%02x:%02x:%02x:%02x' '_PType=%d' ",
                                        mac[0], mac[1], mac[2], mac[3], mac[4], mac[5], type);
                        }

                        k = strappend(s, buf);
                        if (!k)
                                return -ENOMEM;

                        free(s);
                        s = k;

                        time = now(CLOCK_BOOTTIME);

                        /* Don't write expired packets */
                        if (time - p->until <= 0)
                                continue;

                        sprintf(buf, "'_TTL="USEC_FMT"' ", p->until);

                        k = strappend(s, buf);
                        if (!k)
                                return -ENOMEM;

                        free(s);
                        s = k;

                        r = lldp_read_system_name(p->packet, &length, &k);
                        if (r < 0)
                                k = strappend(s, "'_NAME=N/A' ");
                        else {
                                t = strndup(k, length);
                                if (!t)
                                        return -ENOMEM;

                                k = strjoin(s, "'_NAME=", t, "' ", NULL);
                                free(t);
                        }

                        if (!k)
                                return -ENOMEM;

                        free(s);
                        s = k;

                        (void) lldp_read_system_capability(p->packet, &data);

                        sprintf(buf, "'_CAP=%x'", data);

                        k = strappend(s, buf);
                        if (!k)
                                return -ENOMEM;

                        free(s);
                        s = k;

                        fprintf(f, "%s\n", s);
                }
        }
        r = 0;

        fflush(f);

        if (ferror(f) || rename(temp_path, lldp_file) < 0) {
                r = -errno;
                unlink(lldp_file);
                unlink(temp_path);
        }

 finish:
        if (r < 0)
                log_error("Failed to save lldp data %s: %s", lldp_file, strerror(-r));

        return r;
}

int sd_lldp_start(sd_lldp *lldp) {
        int r;

        assert_return(lldp, -EINVAL);
        assert_return(lldp->port, -EINVAL);

        lldp->port->status = LLDP_PORT_STATUS_ENABLED;

        lldp_set_state(lldp, LLDP_AGENT_RX_LLDP_INITIALIZE);

        r = lldp_port_start(lldp->port);
        if (r < 0) {
                log_lldp("Failed to start Port : %s , %s",
                         lldp->port->ifname,
                         strerror(-r));

                lldp_set_state(lldp, LLDP_AGENT_RX_WAIT_PORT_OPERATIONAL);

                return r;
        }

        lldp_set_state(lldp, LLDP_AGENT_RX_WAIT_FOR_FRAME);

        return 0;
}

int sd_lldp_stop(sd_lldp *lldp) {
        int r;

        assert_return(lldp, -EINVAL);
        assert_return(lldp->port, -EINVAL);

        lldp->port->status = LLDP_PORT_STATUS_DISABLED;

        r = lldp_port_stop(lldp->port);
        if (r < 0)
                return r;

        lldp_mib_objects_flush(lldp);

        return 0;
}

int sd_lldp_attach_event(sd_lldp *lldp, sd_event *event, int priority) {
        int r;

        assert_return(lldp, -EINVAL);
        assert_return(!lldp->port->event, -EBUSY);

        if (event)
                lldp->port->event = sd_event_ref(event);
        else {
                r = sd_event_default(&lldp->port->event);
                if (r < 0)
                        return r;
        }

        lldp->port->event_priority = priority;

        return 0;
}

int sd_lldp_detach_event(sd_lldp *lldp) {

        assert_return(lldp, -EINVAL);

        lldp->port->event = sd_event_unref(lldp->port->event);

        return 0;
}

int sd_lldp_set_callback(sd_lldp *lldp, sd_lldp_cb_t cb, void *userdata) {
        assert_return(lldp, -EINVAL);

        lldp->cb = cb;
        lldp->userdata = userdata;

        return 0;
}

void sd_lldp_free(sd_lldp *lldp) {

        if (!lldp)
                return;

        /* Drop all packets */
        lldp_mib_objects_flush(lldp);

        lldp_port_free(lldp->port);

        hashmap_free(lldp->neighbour_mib);
        prioq_free(lldp->by_expiry);

        free(lldp);
}

int sd_lldp_new(int ifindex,
                const char *ifname,
                const struct ether_addr *mac,
                sd_lldp **ret) {
        _cleanup_lldp_free_ sd_lldp *lldp = NULL;
        int r;

        assert_return(ret, -EINVAL);
        assert_return(ifindex > 0, -EINVAL);
        assert_return(ifname, -EINVAL);
        assert_return(mac, -EINVAL);

        lldp = new0(sd_lldp, 1);
        if (!lldp)
                return -ENOMEM;

        r = lldp_port_new(ifindex, ifname, mac, lldp, &lldp->port);
        if (r < 0)
                return r;

        lldp->neighbour_mib = hashmap_new(&chassis_id_hash_ops);
        if (!lldp->neighbour_mib)
                return -ENOMEM;

        r = prioq_ensure_allocated(&lldp->by_expiry,
                                   ttl_expiry_item_prioq_compare_func);
        if (r < 0)
                return r;

        lldp->rx_state = LLDP_AGENT_RX_WAIT_PORT_OPERATIONAL;

        *ret = lldp;
        lldp = NULL;

        return 0;
}