--- /dev/null
+/***
+ This file is part of systemd.
+
+ Copyright 2016 Lennart Poettering
+
+ 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 <endian.h>
+#include <inttypes.h>
+#include <string.h>
+
+#include "fd-util.h"
+#include "fileio.h"
+#include "hostname-util.h"
+#include "lldp.h"
+#include "networkd-lldp-tx.h"
+#include "random-util.h"
+#include "socket-util.h"
+#include "string-util.h"
+#include "unaligned.h"
+
+/* The LLDP spec calls this "txFastInit", see 9.2.5.19 */
+#define LLDP_TX_FAST_INIT 4U
+
+/* The LLDP spec calls this "msgTxHold", see 9.2.5.6 */
+#define LLDP_TX_HOLD 4U
+
+/* The jitter range to add, see 9.2.2. */
+#define LLDP_JITTER_USEC (400U * USEC_PER_MSEC)
+
+/* The LLDP spec calls this msgTxInterval, but we subtract half the jitter off it. */
+#define LLDP_TX_INTERVAL_USEC (30U * USEC_PER_SEC - LLDP_JITTER_USEC / 2)
+
+/* The LLDP spec calls this msgFastTx, but we subtract half the jitter off it. */
+#define LLDP_FAST_TX_USEC (1U * USEC_PER_SEC - LLDP_JITTER_USEC / 2)
+
+static int lldp_write_tlv_header(uint8_t **p, uint8_t id, size_t sz) {
+ assert(p);
+
+ if (id > 127)
+ return -EBADMSG;
+ if (sz > 511)
+ return -ENOBUFS;
+
+ (*p)[0] = (id << 1) | !!(sz & 256);
+ (*p)[1] = sz & 255;
+
+ *p = *p + 2;
+ return 0;
+}
+
+static int lldp_make_packet(
+ const struct ether_addr *hwaddr,
+ const char *machine_id,
+ const char *ifname,
+ uint16_t ttl,
+ const char *port_description,
+ const char *hostname,
+ const char *pretty_hostname,
+ uint16_t system_capabilities,
+ uint16_t enabled_capabilities,
+ void **ret, size_t *sz) {
+
+ size_t machine_id_length, ifname_length, port_description_length = 0, hostname_length = 0, pretty_hostname_length = 0;
+ _cleanup_free_ void *packet = NULL;
+ struct ether_header *h;
+ uint8_t *p;
+ size_t l;
+ int r;
+
+ assert(hwaddr);
+ assert(machine_id);
+ assert(ifname);
+ assert(ret);
+ assert(sz);
+
+ machine_id_length = strlen(machine_id);
+ ifname_length = strlen(ifname);
+
+ if (port_description)
+ port_description_length = strlen(port_description);
+
+ if (hostname)
+ hostname_length = strlen(hostname);
+
+ if (pretty_hostname)
+ pretty_hostname_length = strlen(pretty_hostname);
+
+ l = sizeof(struct ether_header) +
+ /* Chassis ID */
+ 2 + 1 + machine_id_length +
+ /* Port ID */
+ 2 + 1 + ifname_length +
+ /* TTL */
+ 2 + 2 +
+ /* System Capabilities */
+ 2 + 4 +
+ /* End */
+ 2;
+
+ /* Port Description */
+ if (port_description)
+ l += 2 + port_description_length;
+
+ /* System Name */
+ if (hostname)
+ l += 2 + hostname_length;
+
+ /* System Description */
+ if (pretty_hostname)
+ l += 2 + pretty_hostname_length;
+
+ packet = malloc(l);
+ if (!packet)
+ return -ENOMEM;
+
+ h = (struct ether_header*) packet;
+ h->ether_type = htobe16(ETHERTYPE_LLDP);
+ memcpy(h->ether_dhost, &(struct ether_addr) { LLDP_MULTICAST_ADDR }, ETH_ALEN);
+ memcpy(h->ether_shost, hwaddr, ETH_ALEN);
+
+ p = (uint8_t*) packet + sizeof(struct ether_header);
+
+ r = lldp_write_tlv_header(&p, LLDP_TYPE_CHASSIS_ID, 1 + machine_id_length);
+ if (r < 0)
+ return r;
+ *(p++) = LLDP_CHASSIS_SUBTYPE_LOCALLY_ASSIGNED;
+ p = mempcpy(p, machine_id, machine_id_length);
+
+ r = lldp_write_tlv_header(&p, LLDP_TYPE_PORT_ID, 1 + ifname_length);
+ if (r < 0)
+ return r;
+ *(p++) = LLDP_PORT_SUBTYPE_INTERFACE_NAME;
+ p = mempcpy(p, ifname, ifname_length);
+
+ r = lldp_write_tlv_header(&p, LLDP_TYPE_TTL, 2);
+ if (r < 0)
+ return r;
+ unaligned_write_be16(p, ttl);
+ p += 2;
+
+ if (port_description) {
+ r = lldp_write_tlv_header(&p, LLDP_TYPE_PORT_DESCRIPTION, port_description_length);
+ if (r < 0)
+ return r;
+ p = mempcpy(p, port_description, port_description_length);
+ }
+
+ if (hostname) {
+ r = lldp_write_tlv_header(&p, LLDP_TYPE_SYSTEM_NAME, hostname_length);
+ if (r < 0)
+ return r;
+ p = mempcpy(p, hostname, hostname_length);
+ }
+
+ if (pretty_hostname) {
+ r = lldp_write_tlv_header(&p, LLDP_TYPE_SYSTEM_DESCRIPTION, pretty_hostname_length);
+ if (r < 0)
+ return r;
+ p = mempcpy(p, pretty_hostname, pretty_hostname_length);
+ }
+
+ r = lldp_write_tlv_header(&p, LLDP_TYPE_SYSTEM_CAPABILITIES, 4);
+ if (r < 0)
+ return r;
+ unaligned_write_be16(p, system_capabilities);
+ p += 2;
+ unaligned_write_be16(p, enabled_capabilities);
+ p += 2;
+
+ r = lldp_write_tlv_header(&p, LLDP_TYPE_END, 0);
+ if (r < 0)
+ return r;
+
+ assert(p == (uint8_t*) packet + l);
+
+ *ret = packet;
+ *sz = l;
+
+ packet = NULL;
+ return 0;
+}
+
+static int lldp_send_packet(int ifindex, const void *packet, size_t packet_size) {
+
+ union sockaddr_union sa = {
+ .ll.sll_family = AF_PACKET,
+ .ll.sll_protocol = htobe16(ETHERTYPE_LLDP),
+ .ll.sll_ifindex = ifindex,
+ .ll.sll_halen = ETH_ALEN,
+ .ll.sll_addr = LLDP_MULTICAST_ADDR,
+ };
+
+ _cleanup_close_ int fd = -1;
+ ssize_t l;
+
+ assert(ifindex > 0);
+ assert(packet || packet_size <= 0);
+
+ fd = socket(PF_PACKET, SOCK_RAW|SOCK_CLOEXEC, IPPROTO_RAW);
+ if (fd < 0)
+ return -errno;
+
+ l = sendto(fd, packet, packet_size, MSG_NOSIGNAL, &sa.sa, sizeof(sa.ll));
+ if (l < 0)
+ return -errno;
+
+ if ((size_t) l != packet_size)
+ return -EIO;
+
+ return 0;
+}
+
+static int link_send_lldp(Link *link) {
+ char machine_id_string[SD_ID128_STRING_MAX];
+ _cleanup_free_ char *hostname = NULL, *pretty_hostname = NULL;
+ _cleanup_free_ void *packet = NULL;
+ size_t packet_size = 0;
+ sd_id128_t machine_id;
+ uint16_t caps;
+ usec_t ttl;
+ int r;
+
+ r = sd_id128_get_machine(&machine_id);
+ if (r < 0)
+ return r;
+
+ (void) gethostname_strict(&hostname);
+ (void) parse_env_file("/etc/machine-info", NEWLINE, "PRETTY_HOSTNAME", &pretty_hostname, NULL);
+
+ ttl = DIV_ROUND_UP(LLDP_TX_INTERVAL_USEC * LLDP_TX_HOLD + 1, USEC_PER_SEC);
+ if (ttl > (usec_t) UINT16_MAX)
+ ttl = (usec_t) UINT16_MAX;
+
+ caps = (link->network && link->network->ip_forward != ADDRESS_FAMILY_NO) ?
+ LLDP_SYSTEM_CAPABILITIES_ROUTER :
+ LLDP_SYSTEM_CAPABILITIES_STATION;
+
+ r = lldp_make_packet(&link->mac,
+ sd_id128_to_string(machine_id, machine_id_string),
+ link->ifname,
+ (uint16_t) ttl,
+ link->network ? link->network->description : NULL,
+ hostname,
+ pretty_hostname,
+ LLDP_SYSTEM_CAPABILITIES_STATION|LLDP_SYSTEM_CAPABILITIES_BRIDGE|LLDP_SYSTEM_CAPABILITIES_ROUTER,
+ caps,
+ &packet, &packet_size);
+ if (r < 0)
+ return r;
+
+ return lldp_send_packet(link->ifindex, packet, packet_size);
+}
+
+static int on_lldp_timer(sd_event_source *s, usec_t t, void *userdata) {
+ Link *link = userdata;
+ usec_t current, delay, next;
+ int r;
+
+ assert(s);
+ assert(userdata);
+
+ log_link_debug(link, "Sending LLDP packet...");
+
+ r = link_send_lldp(link);
+ if (r < 0)
+ log_link_debug_errno(link, r, "Failed to send LLDP packet, ignoring: %m");
+
+ if (link->lldp_tx_fast > 0)
+ link->lldp_tx_fast--;
+
+ assert_se(sd_event_now(sd_event_source_get_event(s), clock_boottime_or_monotonic(), ¤t) >= 0);
+
+ delay = link->lldp_tx_fast > 0 ? LLDP_FAST_TX_USEC : LLDP_TX_INTERVAL_USEC;
+ next = usec_add(usec_add(current, delay), (usec_t) random_u64() % LLDP_JITTER_USEC);
+
+ r = sd_event_source_set_time(s, next);
+ if (r < 0)
+ return log_link_error_errno(link, r, "Failed to restart LLDP timer: %m");
+
+ r = sd_event_source_set_enabled(s, SD_EVENT_ONESHOT);
+ if (r < 0)
+ return log_link_error_errno(link, r, "Failed to enable LLDP timer: %m");
+
+ return 0;
+}
+
+int link_lldp_tx_start(Link *link) {
+ usec_t next;
+ int r;
+
+ assert(link);
+
+ /* Starts the LLDP transmission in "fast" mode. If it is already started, turns "fast" mode back on again. */
+
+ link->lldp_tx_fast = LLDP_TX_FAST_INIT;
+
+ next = usec_add(usec_add(now(clock_boottime_or_monotonic()), LLDP_FAST_TX_USEC),
+ (usec_t) random_u64() % LLDP_JITTER_USEC);
+
+ if (link->lldp_tx_event_source) {
+ usec_t old;
+
+ /* Lower the timeout, maybe */
+ r = sd_event_source_get_time(link->lldp_tx_event_source, &old);
+ if (r < 0)
+ return r;
+
+ if (old <= next)
+ return 0;
+
+ return sd_event_source_set_time(link->lldp_tx_event_source, next);
+ } else {
+ r = sd_event_add_time(
+ link->manager->event,
+ &link->lldp_tx_event_source,
+ clock_boottime_or_monotonic(),
+ next,
+ 0,
+ on_lldp_timer,
+ link);
+ if (r < 0)
+ return r;
+
+ (void) sd_event_source_set_description(link->lldp_tx_event_source, "lldp-tx");
+ }
+
+ return 0;
+}
+
+void link_lldp_tx_stop(Link *link) {
+ assert(link);
+
+ link->lldp_tx_event_source = sd_event_source_unref(link->lldp_tx_event_source);
+}
projects / thirdparty / systemd.git / commitdiff
