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53e1b683 | 1 | /* SPDX-License-Identifier: LGPL-2.1+ */ |
8e1ad1ea LP |
2 | /*** |
3 | This file is part of systemd. | |
4 | ||
5 | Copyright 2016 Lennart Poettering | |
6 | ||
7 | systemd is free software; you can redistribute it and/or modify it | |
8 | under the terms of the GNU Lesser General Public License as published by | |
9 | the Free Software Foundation; either version 2.1 of the License, or | |
10 | (at your option) any later version. | |
11 | ||
12 | systemd is distributed in the hope that it will be useful, but | |
13 | WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
15 | Lesser General Public License for more details. | |
16 | ||
17 | You should have received a copy of the GNU Lesser General Public License | |
18 | along with systemd; If not, see <http://www.gnu.org/licenses/>. | |
19 | ***/ | |
20 | ||
21 | #include <endian.h> | |
22 | #include <inttypes.h> | |
23 | #include <string.h> | |
24 | ||
634f0f98 | 25 | #include "alloc-util.h" |
8e1ad1ea LP |
26 | #include "fd-util.h" |
27 | #include "fileio.h" | |
28 | #include "hostname-util.h" | |
7272b25e | 29 | #include "networkd-lldp-tx.h" |
23f53b99 | 30 | #include "networkd-manager.h" |
7272b25e | 31 | #include "parse-util.h" |
8e1ad1ea LP |
32 | #include "random-util.h" |
33 | #include "socket-util.h" | |
34 | #include "string-util.h" | |
35 | #include "unaligned.h" | |
36 | ||
37 | /* The LLDP spec calls this "txFastInit", see 9.2.5.19 */ | |
38 | #define LLDP_TX_FAST_INIT 4U | |
39 | ||
40 | /* The LLDP spec calls this "msgTxHold", see 9.2.5.6 */ | |
41 | #define LLDP_TX_HOLD 4U | |
42 | ||
43 | /* The jitter range to add, see 9.2.2. */ | |
44 | #define LLDP_JITTER_USEC (400U * USEC_PER_MSEC) | |
45 | ||
46 | /* The LLDP spec calls this msgTxInterval, but we subtract half the jitter off it. */ | |
47 | #define LLDP_TX_INTERVAL_USEC (30U * USEC_PER_SEC - LLDP_JITTER_USEC / 2) | |
48 | ||
49 | /* The LLDP spec calls this msgFastTx, but we subtract half the jitter off it. */ | |
50 | #define LLDP_FAST_TX_USEC (1U * USEC_PER_SEC - LLDP_JITTER_USEC / 2) | |
51 | ||
7272b25e LP |
52 | static const struct ether_addr lldp_multicast_addr[_LLDP_EMIT_MAX] = { |
53 | [LLDP_EMIT_NEAREST_BRIDGE] = {{ 0x01, 0x80, 0xc2, 0x00, 0x00, 0x0e }}, | |
54 | [LLDP_EMIT_NON_TPMR_BRIDGE] = {{ 0x01, 0x80, 0xc2, 0x00, 0x00, 0x03 }}, | |
55 | [LLDP_EMIT_CUSTOMER_BRIDGE] = {{ 0x01, 0x80, 0xc2, 0x00, 0x00, 0x00 }}, | |
56 | }; | |
57 | ||
8e1ad1ea LP |
58 | static int lldp_write_tlv_header(uint8_t **p, uint8_t id, size_t sz) { |
59 | assert(p); | |
60 | ||
61 | if (id > 127) | |
62 | return -EBADMSG; | |
63 | if (sz > 511) | |
64 | return -ENOBUFS; | |
65 | ||
66 | (*p)[0] = (id << 1) | !!(sz & 256); | |
67 | (*p)[1] = sz & 255; | |
68 | ||
69 | *p = *p + 2; | |
70 | return 0; | |
71 | } | |
72 | ||
73 | static int lldp_make_packet( | |
7272b25e | 74 | LLDPEmit mode, |
8e1ad1ea LP |
75 | const struct ether_addr *hwaddr, |
76 | const char *machine_id, | |
77 | const char *ifname, | |
78 | uint16_t ttl, | |
79 | const char *port_description, | |
80 | const char *hostname, | |
81 | const char *pretty_hostname, | |
82 | uint16_t system_capabilities, | |
83 | uint16_t enabled_capabilities, | |
84 | void **ret, size_t *sz) { | |
85 | ||
86 | size_t machine_id_length, ifname_length, port_description_length = 0, hostname_length = 0, pretty_hostname_length = 0; | |
87 | _cleanup_free_ void *packet = NULL; | |
88 | struct ether_header *h; | |
89 | uint8_t *p; | |
90 | size_t l; | |
91 | int r; | |
92 | ||
7272b25e LP |
93 | assert(mode > LLDP_EMIT_NO); |
94 | assert(mode < _LLDP_EMIT_MAX); | |
8e1ad1ea LP |
95 | assert(hwaddr); |
96 | assert(machine_id); | |
97 | assert(ifname); | |
98 | assert(ret); | |
99 | assert(sz); | |
100 | ||
101 | machine_id_length = strlen(machine_id); | |
102 | ifname_length = strlen(ifname); | |
103 | ||
104 | if (port_description) | |
105 | port_description_length = strlen(port_description); | |
106 | ||
107 | if (hostname) | |
108 | hostname_length = strlen(hostname); | |
109 | ||
110 | if (pretty_hostname) | |
111 | pretty_hostname_length = strlen(pretty_hostname); | |
112 | ||
113 | l = sizeof(struct ether_header) + | |
114 | /* Chassis ID */ | |
115 | 2 + 1 + machine_id_length + | |
116 | /* Port ID */ | |
117 | 2 + 1 + ifname_length + | |
118 | /* TTL */ | |
119 | 2 + 2 + | |
120 | /* System Capabilities */ | |
121 | 2 + 4 + | |
122 | /* End */ | |
123 | 2; | |
124 | ||
125 | /* Port Description */ | |
126 | if (port_description) | |
127 | l += 2 + port_description_length; | |
128 | ||
129 | /* System Name */ | |
130 | if (hostname) | |
131 | l += 2 + hostname_length; | |
132 | ||
133 | /* System Description */ | |
134 | if (pretty_hostname) | |
135 | l += 2 + pretty_hostname_length; | |
136 | ||
137 | packet = malloc(l); | |
138 | if (!packet) | |
139 | return -ENOMEM; | |
140 | ||
141 | h = (struct ether_header*) packet; | |
142 | h->ether_type = htobe16(ETHERTYPE_LLDP); | |
7272b25e | 143 | memcpy(h->ether_dhost, lldp_multicast_addr + mode, ETH_ALEN); |
8e1ad1ea LP |
144 | memcpy(h->ether_shost, hwaddr, ETH_ALEN); |
145 | ||
146 | p = (uint8_t*) packet + sizeof(struct ether_header); | |
147 | ||
6afa6767 | 148 | r = lldp_write_tlv_header(&p, SD_LLDP_TYPE_CHASSIS_ID, 1 + machine_id_length); |
8e1ad1ea LP |
149 | if (r < 0) |
150 | return r; | |
6afa6767 | 151 | *(p++) = SD_LLDP_CHASSIS_SUBTYPE_LOCALLY_ASSIGNED; |
8e1ad1ea LP |
152 | p = mempcpy(p, machine_id, machine_id_length); |
153 | ||
6afa6767 | 154 | r = lldp_write_tlv_header(&p, SD_LLDP_TYPE_PORT_ID, 1 + ifname_length); |
8e1ad1ea LP |
155 | if (r < 0) |
156 | return r; | |
6afa6767 | 157 | *(p++) = SD_LLDP_PORT_SUBTYPE_INTERFACE_NAME; |
8e1ad1ea LP |
158 | p = mempcpy(p, ifname, ifname_length); |
159 | ||
6afa6767 | 160 | r = lldp_write_tlv_header(&p, SD_LLDP_TYPE_TTL, 2); |
8e1ad1ea LP |
161 | if (r < 0) |
162 | return r; | |
163 | unaligned_write_be16(p, ttl); | |
164 | p += 2; | |
165 | ||
166 | if (port_description) { | |
6afa6767 | 167 | r = lldp_write_tlv_header(&p, SD_LLDP_TYPE_PORT_DESCRIPTION, port_description_length); |
8e1ad1ea LP |
168 | if (r < 0) |
169 | return r; | |
170 | p = mempcpy(p, port_description, port_description_length); | |
171 | } | |
172 | ||
173 | if (hostname) { | |
6afa6767 | 174 | r = lldp_write_tlv_header(&p, SD_LLDP_TYPE_SYSTEM_NAME, hostname_length); |
8e1ad1ea LP |
175 | if (r < 0) |
176 | return r; | |
177 | p = mempcpy(p, hostname, hostname_length); | |
178 | } | |
179 | ||
180 | if (pretty_hostname) { | |
6afa6767 | 181 | r = lldp_write_tlv_header(&p, SD_LLDP_TYPE_SYSTEM_DESCRIPTION, pretty_hostname_length); |
8e1ad1ea LP |
182 | if (r < 0) |
183 | return r; | |
184 | p = mempcpy(p, pretty_hostname, pretty_hostname_length); | |
185 | } | |
186 | ||
6afa6767 | 187 | r = lldp_write_tlv_header(&p, SD_LLDP_TYPE_SYSTEM_CAPABILITIES, 4); |
8e1ad1ea LP |
188 | if (r < 0) |
189 | return r; | |
190 | unaligned_write_be16(p, system_capabilities); | |
191 | p += 2; | |
192 | unaligned_write_be16(p, enabled_capabilities); | |
193 | p += 2; | |
194 | ||
6afa6767 | 195 | r = lldp_write_tlv_header(&p, SD_LLDP_TYPE_END, 0); |
8e1ad1ea LP |
196 | if (r < 0) |
197 | return r; | |
198 | ||
199 | assert(p == (uint8_t*) packet + l); | |
200 | ||
201 | *ret = packet; | |
202 | *sz = l; | |
203 | ||
204 | packet = NULL; | |
205 | return 0; | |
206 | } | |
207 | ||
7272b25e LP |
208 | static int lldp_send_packet( |
209 | int ifindex, | |
210 | const struct ether_addr *address, | |
211 | const void *packet, | |
212 | size_t packet_size) { | |
8e1ad1ea LP |
213 | |
214 | union sockaddr_union sa = { | |
215 | .ll.sll_family = AF_PACKET, | |
216 | .ll.sll_protocol = htobe16(ETHERTYPE_LLDP), | |
217 | .ll.sll_ifindex = ifindex, | |
218 | .ll.sll_halen = ETH_ALEN, | |
8e1ad1ea LP |
219 | }; |
220 | ||
221 | _cleanup_close_ int fd = -1; | |
222 | ssize_t l; | |
223 | ||
224 | assert(ifindex > 0); | |
7272b25e | 225 | assert(address); |
8e1ad1ea LP |
226 | assert(packet || packet_size <= 0); |
227 | ||
7272b25e LP |
228 | memcpy(sa.ll.sll_addr, address, ETH_ALEN); |
229 | ||
8e1ad1ea LP |
230 | fd = socket(PF_PACKET, SOCK_RAW|SOCK_CLOEXEC, IPPROTO_RAW); |
231 | if (fd < 0) | |
232 | return -errno; | |
233 | ||
234 | l = sendto(fd, packet, packet_size, MSG_NOSIGNAL, &sa.sa, sizeof(sa.ll)); | |
235 | if (l < 0) | |
236 | return -errno; | |
237 | ||
238 | if ((size_t) l != packet_size) | |
239 | return -EIO; | |
240 | ||
241 | return 0; | |
242 | } | |
243 | ||
244 | static int link_send_lldp(Link *link) { | |
245 | char machine_id_string[SD_ID128_STRING_MAX]; | |
246 | _cleanup_free_ char *hostname = NULL, *pretty_hostname = NULL; | |
247 | _cleanup_free_ void *packet = NULL; | |
248 | size_t packet_size = 0; | |
249 | sd_id128_t machine_id; | |
250 | uint16_t caps; | |
251 | usec_t ttl; | |
252 | int r; | |
253 | ||
7272b25e LP |
254 | assert(link); |
255 | ||
256 | if (!link->network || link->network->lldp_emit == LLDP_EMIT_NO) | |
257 | return 0; | |
258 | ||
259 | assert(link->network->lldp_emit < _LLDP_EMIT_MAX); | |
260 | ||
8e1ad1ea LP |
261 | r = sd_id128_get_machine(&machine_id); |
262 | if (r < 0) | |
263 | return r; | |
264 | ||
265 | (void) gethostname_strict(&hostname); | |
266 | (void) parse_env_file("/etc/machine-info", NEWLINE, "PRETTY_HOSTNAME", &pretty_hostname, NULL); | |
267 | ||
c8cf4dc1 | 268 | assert_cc(LLDP_TX_INTERVAL_USEC * LLDP_TX_HOLD + 1 <= (UINT16_MAX - 1) * USEC_PER_SEC); |
8e1ad1ea | 269 | ttl = DIV_ROUND_UP(LLDP_TX_INTERVAL_USEC * LLDP_TX_HOLD + 1, USEC_PER_SEC); |
8e1ad1ea LP |
270 | |
271 | caps = (link->network && link->network->ip_forward != ADDRESS_FAMILY_NO) ? | |
6afa6767 BG |
272 | SD_LLDP_SYSTEM_CAPABILITIES_ROUTER : |
273 | SD_LLDP_SYSTEM_CAPABILITIES_STATION; | |
8e1ad1ea | 274 | |
7272b25e LP |
275 | r = lldp_make_packet(link->network->lldp_emit, |
276 | &link->mac, | |
8e1ad1ea LP |
277 | sd_id128_to_string(machine_id, machine_id_string), |
278 | link->ifname, | |
279 | (uint16_t) ttl, | |
280 | link->network ? link->network->description : NULL, | |
281 | hostname, | |
282 | pretty_hostname, | |
6afa6767 | 283 | SD_LLDP_SYSTEM_CAPABILITIES_STATION|SD_LLDP_SYSTEM_CAPABILITIES_BRIDGE|SD_LLDP_SYSTEM_CAPABILITIES_ROUTER, |
8e1ad1ea LP |
284 | caps, |
285 | &packet, &packet_size); | |
286 | if (r < 0) | |
287 | return r; | |
288 | ||
7272b25e | 289 | return lldp_send_packet(link->ifindex, lldp_multicast_addr + link->network->lldp_emit, packet, packet_size); |
8e1ad1ea LP |
290 | } |
291 | ||
292 | static int on_lldp_timer(sd_event_source *s, usec_t t, void *userdata) { | |
293 | Link *link = userdata; | |
294 | usec_t current, delay, next; | |
295 | int r; | |
296 | ||
297 | assert(s); | |
298 | assert(userdata); | |
299 | ||
300 | log_link_debug(link, "Sending LLDP packet..."); | |
301 | ||
302 | r = link_send_lldp(link); | |
303 | if (r < 0) | |
304 | log_link_debug_errno(link, r, "Failed to send LLDP packet, ignoring: %m"); | |
305 | ||
306 | if (link->lldp_tx_fast > 0) | |
307 | link->lldp_tx_fast--; | |
308 | ||
309 | assert_se(sd_event_now(sd_event_source_get_event(s), clock_boottime_or_monotonic(), ¤t) >= 0); | |
310 | ||
311 | delay = link->lldp_tx_fast > 0 ? LLDP_FAST_TX_USEC : LLDP_TX_INTERVAL_USEC; | |
312 | next = usec_add(usec_add(current, delay), (usec_t) random_u64() % LLDP_JITTER_USEC); | |
313 | ||
314 | r = sd_event_source_set_time(s, next); | |
315 | if (r < 0) | |
316 | return log_link_error_errno(link, r, "Failed to restart LLDP timer: %m"); | |
317 | ||
318 | r = sd_event_source_set_enabled(s, SD_EVENT_ONESHOT); | |
319 | if (r < 0) | |
320 | return log_link_error_errno(link, r, "Failed to enable LLDP timer: %m"); | |
321 | ||
322 | return 0; | |
323 | } | |
324 | ||
7272b25e | 325 | int link_lldp_emit_start(Link *link) { |
8e1ad1ea LP |
326 | usec_t next; |
327 | int r; | |
328 | ||
329 | assert(link); | |
330 | ||
7272b25e LP |
331 | if (!link->network || link->network->lldp_emit == LLDP_EMIT_NO) { |
332 | link_lldp_emit_stop(link); | |
333 | return 0; | |
334 | } | |
335 | ||
8e1ad1ea LP |
336 | /* Starts the LLDP transmission in "fast" mode. If it is already started, turns "fast" mode back on again. */ |
337 | ||
338 | link->lldp_tx_fast = LLDP_TX_FAST_INIT; | |
339 | ||
340 | next = usec_add(usec_add(now(clock_boottime_or_monotonic()), LLDP_FAST_TX_USEC), | |
341 | (usec_t) random_u64() % LLDP_JITTER_USEC); | |
342 | ||
7272b25e | 343 | if (link->lldp_emit_event_source) { |
8e1ad1ea LP |
344 | usec_t old; |
345 | ||
346 | /* Lower the timeout, maybe */ | |
7272b25e | 347 | r = sd_event_source_get_time(link->lldp_emit_event_source, &old); |
8e1ad1ea LP |
348 | if (r < 0) |
349 | return r; | |
350 | ||
351 | if (old <= next) | |
352 | return 0; | |
353 | ||
7272b25e | 354 | return sd_event_source_set_time(link->lldp_emit_event_source, next); |
8e1ad1ea LP |
355 | } else { |
356 | r = sd_event_add_time( | |
357 | link->manager->event, | |
7272b25e | 358 | &link->lldp_emit_event_source, |
8e1ad1ea LP |
359 | clock_boottime_or_monotonic(), |
360 | next, | |
361 | 0, | |
362 | on_lldp_timer, | |
363 | link); | |
364 | if (r < 0) | |
365 | return r; | |
366 | ||
7272b25e | 367 | (void) sd_event_source_set_description(link->lldp_emit_event_source, "lldp-tx"); |
8e1ad1ea LP |
368 | } |
369 | ||
370 | return 0; | |
371 | } | |
372 | ||
7272b25e | 373 | void link_lldp_emit_stop(Link *link) { |
8e1ad1ea LP |
374 | assert(link); |
375 | ||
7272b25e LP |
376 | link->lldp_emit_event_source = sd_event_source_unref(link->lldp_emit_event_source); |
377 | } | |
378 | ||
379 | int config_parse_lldp_emit( | |
380 | const char *unit, | |
381 | const char *filename, | |
382 | unsigned line, | |
383 | const char *section, | |
384 | unsigned section_line, | |
385 | const char *lvalue, | |
386 | int ltype, | |
387 | const char *rvalue, | |
388 | void *data, | |
389 | void *userdata) { | |
390 | ||
391 | LLDPEmit *emit = data; | |
392 | int r; | |
393 | ||
394 | assert(filename); | |
395 | assert(lvalue); | |
396 | assert(rvalue); | |
397 | ||
398 | if (isempty(rvalue)) | |
399 | *emit = LLDP_EMIT_NO; | |
400 | else if (streq(rvalue, "nearest-bridge")) | |
401 | *emit = LLDP_EMIT_NEAREST_BRIDGE; | |
402 | else if (streq(rvalue, "non-tpmr-bridge")) | |
403 | *emit = LLDP_EMIT_NON_TPMR_BRIDGE; | |
404 | else if (streq(rvalue, "customer-bridge")) | |
405 | *emit = LLDP_EMIT_CUSTOMER_BRIDGE; | |
406 | else { | |
407 | r = parse_boolean(rvalue); | |
408 | if (r < 0) { | |
409 | log_syntax(unit, LOG_ERR, filename, line, 0, "Failed to parse LLDP emission setting, ignoring: %s", rvalue); | |
410 | return 0; | |
411 | } | |
412 | ||
413 | *emit = r ? LLDP_EMIT_NEAREST_BRIDGE : LLDP_EMIT_NO; | |
414 | } | |
415 | ||
416 | return 0; | |
8e1ad1ea | 417 | } |