1 /* SPDX-License-Identifier: LGPL-2.1+ */
6 #include <net/if_arp.h>
8 #include "alloc-util.h"
11 #include "hostname-util.h"
12 #include "missing_network.h"
13 #include "networkd-link.h"
14 #include "networkd-lldp-tx.h"
15 #include "networkd-manager.h"
16 #include "parse-util.h"
17 #include "random-util.h"
18 #include "socket-util.h"
19 #include "string-util.h"
20 #include "unaligned.h"
22 /* The LLDP spec calls this "txFastInit", see 9.2.5.19 */
23 #define LLDP_TX_FAST_INIT 4U
25 /* The LLDP spec calls this "msgTxHold", see 9.2.5.6 */
26 #define LLDP_TX_HOLD 4U
28 /* The jitter range to add, see 9.2.2. */
29 #define LLDP_JITTER_USEC (400U * USEC_PER_MSEC)
31 /* The LLDP spec calls this msgTxInterval, but we subtract half the jitter off it. */
32 #define LLDP_TX_INTERVAL_USEC (30U * USEC_PER_SEC - LLDP_JITTER_USEC / 2)
34 /* The LLDP spec calls this msgFastTx, but we subtract half the jitter off it. */
35 #define LLDP_FAST_TX_USEC (1U * USEC_PER_SEC - LLDP_JITTER_USEC / 2)
37 static const struct ether_addr lldp_multicast_addr
[_LLDP_EMIT_MAX
] = {
38 [LLDP_EMIT_NEAREST_BRIDGE
] = {{ 0x01, 0x80, 0xc2, 0x00, 0x00, 0x0e }},
39 [LLDP_EMIT_NON_TPMR_BRIDGE
] = {{ 0x01, 0x80, 0xc2, 0x00, 0x00, 0x03 }},
40 [LLDP_EMIT_CUSTOMER_BRIDGE
] = {{ 0x01, 0x80, 0xc2, 0x00, 0x00, 0x00 }},
43 bool link_lldp_emit_enabled(Link
*link
) {
46 if (link
->flags
& IFF_LOOPBACK
)
49 if (link
->iftype
!= ARPHRD_ETHER
)
55 return link
->network
->lldp_emit
!= LLDP_EMIT_NO
;
58 static int lldp_write_tlv_header(uint8_t **p
, uint8_t id
, size_t sz
) {
66 (*p
)[0] = (id
<< 1) | !!(sz
& 256);
73 static int lldp_make_packet(
75 const struct ether_addr
*hwaddr
,
76 const char *machine_id
,
79 const char *port_description
,
81 const char *pretty_hostname
,
82 uint16_t system_capabilities
,
83 uint16_t enabled_capabilities
,
84 void **ret
, size_t *sz
) {
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
;
93 assert(mode
> LLDP_EMIT_NO
);
94 assert(mode
< _LLDP_EMIT_MAX
);
101 machine_id_length
= strlen(machine_id
);
102 ifname_length
= strlen(ifname
);
104 if (port_description
)
105 port_description_length
= strlen(port_description
);
108 hostname_length
= strlen(hostname
);
111 pretty_hostname_length
= strlen(pretty_hostname
);
113 l
= sizeof(struct ether_header
) +
115 2 + 1 + machine_id_length
+
117 2 + 1 + ifname_length
+
120 /* System Capabilities */
125 /* Port Description */
126 if (port_description
)
127 l
+= 2 + port_description_length
;
131 l
+= 2 + hostname_length
;
133 /* System Description */
135 l
+= 2 + pretty_hostname_length
;
141 h
= (struct ether_header
*) packet
;
142 h
->ether_type
= htobe16(ETHERTYPE_LLDP
);
143 memcpy(h
->ether_dhost
, lldp_multicast_addr
+ mode
, ETH_ALEN
);
144 memcpy(h
->ether_shost
, hwaddr
, ETH_ALEN
);
146 p
= (uint8_t*) packet
+ sizeof(struct ether_header
);
148 r
= lldp_write_tlv_header(&p
, SD_LLDP_TYPE_CHASSIS_ID
, 1 + machine_id_length
);
151 *(p
++) = SD_LLDP_CHASSIS_SUBTYPE_LOCALLY_ASSIGNED
;
152 p
= mempcpy(p
, machine_id
, machine_id_length
);
154 r
= lldp_write_tlv_header(&p
, SD_LLDP_TYPE_PORT_ID
, 1 + ifname_length
);
157 *(p
++) = SD_LLDP_PORT_SUBTYPE_INTERFACE_NAME
;
158 p
= mempcpy(p
, ifname
, ifname_length
);
160 r
= lldp_write_tlv_header(&p
, SD_LLDP_TYPE_TTL
, 2);
163 unaligned_write_be16(p
, ttl
);
166 if (port_description
) {
167 r
= lldp_write_tlv_header(&p
, SD_LLDP_TYPE_PORT_DESCRIPTION
, port_description_length
);
170 p
= mempcpy(p
, port_description
, port_description_length
);
174 r
= lldp_write_tlv_header(&p
, SD_LLDP_TYPE_SYSTEM_NAME
, hostname_length
);
177 p
= mempcpy(p
, hostname
, hostname_length
);
180 if (pretty_hostname
) {
181 r
= lldp_write_tlv_header(&p
, SD_LLDP_TYPE_SYSTEM_DESCRIPTION
, pretty_hostname_length
);
184 p
= mempcpy(p
, pretty_hostname
, pretty_hostname_length
);
187 r
= lldp_write_tlv_header(&p
, SD_LLDP_TYPE_SYSTEM_CAPABILITIES
, 4);
190 unaligned_write_be16(p
, system_capabilities
);
192 unaligned_write_be16(p
, enabled_capabilities
);
195 r
= lldp_write_tlv_header(&p
, SD_LLDP_TYPE_END
, 0);
199 assert(p
== (uint8_t*) packet
+ l
);
201 *ret
= TAKE_PTR(packet
);
207 static int lldp_send_packet(
209 const struct ether_addr
*address
,
211 size_t packet_size
) {
213 union sockaddr_union sa
= {
214 .ll
.sll_family
= AF_PACKET
,
215 .ll
.sll_protocol
= htobe16(ETHERTYPE_LLDP
),
216 .ll
.sll_ifindex
= ifindex
,
217 .ll
.sll_halen
= ETH_ALEN
,
220 _cleanup_close_
int fd
= -1;
225 assert(packet
|| packet_size
<= 0);
227 memcpy(sa
.ll
.sll_addr
, address
, ETH_ALEN
);
229 fd
= socket(PF_PACKET
, SOCK_RAW
|SOCK_CLOEXEC
, IPPROTO_RAW
);
233 l
= sendto(fd
, packet
, packet_size
, MSG_NOSIGNAL
, &sa
.sa
, sizeof(sa
.ll
));
237 if ((size_t) l
!= packet_size
)
243 static int link_send_lldp(Link
*link
) {
244 char machine_id_string
[SD_ID128_STRING_MAX
];
245 _cleanup_free_
char *hostname
= NULL
, *pretty_hostname
= NULL
;
246 _cleanup_free_
void *packet
= NULL
;
247 size_t packet_size
= 0;
248 sd_id128_t machine_id
;
255 if (!link
->network
|| link
->network
->lldp_emit
== LLDP_EMIT_NO
)
258 assert(link
->network
->lldp_emit
< _LLDP_EMIT_MAX
);
260 r
= sd_id128_get_machine(&machine_id
);
264 (void) gethostname_strict(&hostname
);
265 (void) parse_env_file(NULL
, "/etc/machine-info", "PRETTY_HOSTNAME", &pretty_hostname
);
267 assert_cc(LLDP_TX_INTERVAL_USEC
* LLDP_TX_HOLD
+ 1 <= (UINT16_MAX
- 1) * USEC_PER_SEC
);
268 ttl
= DIV_ROUND_UP(LLDP_TX_INTERVAL_USEC
* LLDP_TX_HOLD
+ 1, USEC_PER_SEC
);
270 caps
= (link
->network
&& link
->network
->ip_forward
!= ADDRESS_FAMILY_NO
) ?
271 SD_LLDP_SYSTEM_CAPABILITIES_ROUTER
:
272 SD_LLDP_SYSTEM_CAPABILITIES_STATION
;
274 r
= lldp_make_packet(link
->network
->lldp_emit
,
276 sd_id128_to_string(machine_id
, machine_id_string
),
279 link
->network
? link
->network
->description
: NULL
,
282 SD_LLDP_SYSTEM_CAPABILITIES_STATION
|SD_LLDP_SYSTEM_CAPABILITIES_BRIDGE
|SD_LLDP_SYSTEM_CAPABILITIES_ROUTER
,
284 &packet
, &packet_size
);
288 return lldp_send_packet(link
->ifindex
, lldp_multicast_addr
+ link
->network
->lldp_emit
, packet
, packet_size
);
291 static int on_lldp_timer(sd_event_source
*s
, usec_t t
, void *userdata
) {
292 Link
*link
= userdata
;
293 usec_t current
, delay
, next
;
299 log_link_debug(link
, "Sending LLDP packet...");
301 r
= link_send_lldp(link
);
303 log_link_debug_errno(link
, r
, "Failed to send LLDP packet, ignoring: %m");
305 if (link
->lldp_tx_fast
> 0)
306 link
->lldp_tx_fast
--;
308 assert_se(sd_event_now(sd_event_source_get_event(s
), clock_boottime_or_monotonic(), ¤t
) >= 0);
310 delay
= link
->lldp_tx_fast
> 0 ? LLDP_FAST_TX_USEC
: LLDP_TX_INTERVAL_USEC
;
311 next
= usec_add(usec_add(current
, delay
), (usec_t
) random_u64() % LLDP_JITTER_USEC
);
313 r
= sd_event_source_set_time(s
, next
);
315 return log_link_error_errno(link
, r
, "Failed to restart LLDP timer: %m");
317 r
= sd_event_source_set_enabled(s
, SD_EVENT_ONESHOT
);
319 return log_link_error_errno(link
, r
, "Failed to enable LLDP timer: %m");
324 int link_lldp_emit_start(Link
*link
) {
330 if (!link
->network
|| link
->network
->lldp_emit
== LLDP_EMIT_NO
) {
331 link_lldp_emit_stop(link
);
335 /* Starts the LLDP transmission in "fast" mode. If it is already started, turns "fast" mode back on again. */
337 link
->lldp_tx_fast
= LLDP_TX_FAST_INIT
;
339 next
= usec_add(usec_add(now(clock_boottime_or_monotonic()), LLDP_FAST_TX_USEC
),
340 (usec_t
) random_u64() % LLDP_JITTER_USEC
);
342 if (link
->lldp_emit_event_source
) {
345 /* Lower the timeout, maybe */
346 r
= sd_event_source_get_time(link
->lldp_emit_event_source
, &old
);
353 return sd_event_source_set_time(link
->lldp_emit_event_source
, next
);
355 r
= sd_event_add_time(
356 link
->manager
->event
,
357 &link
->lldp_emit_event_source
,
358 clock_boottime_or_monotonic(),
366 (void) sd_event_source_set_description(link
->lldp_emit_event_source
, "lldp-tx");
372 void link_lldp_emit_stop(Link
*link
) {
375 link
->lldp_emit_event_source
= sd_event_source_unref(link
->lldp_emit_event_source
);
378 int config_parse_lldp_emit(
380 const char *filename
,
383 unsigned section_line
,
390 LLDPEmit
*emit
= data
;
398 *emit
= LLDP_EMIT_NO
;
399 else if (streq(rvalue
, "nearest-bridge"))
400 *emit
= LLDP_EMIT_NEAREST_BRIDGE
;
401 else if (streq(rvalue
, "non-tpmr-bridge"))
402 *emit
= LLDP_EMIT_NON_TPMR_BRIDGE
;
403 else if (streq(rvalue
, "customer-bridge"))
404 *emit
= LLDP_EMIT_CUSTOMER_BRIDGE
;
406 r
= parse_boolean(rvalue
);
408 log_syntax(unit
, LOG_ERR
, filename
, line
, 0, "Failed to parse LLDP emission setting, ignoring: %s", rvalue
);
412 *emit
= r
? LLDP_EMIT_NEAREST_BRIDGE
: LLDP_EMIT_NO
;