| /* SPDX-License-Identifier: LGPL-2.1+ */ |
| /*** |
| 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 "alloc-util.h" |
| #include "fd-util.h" |
| #include "fileio.h" |
| #include "hostname-util.h" |
| #include "networkd-lldp-tx.h" |
| #include "networkd-manager.h" |
| #include "parse-util.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 const struct ether_addr lldp_multicast_addr[_LLDP_EMIT_MAX] = { |
| [LLDP_EMIT_NEAREST_BRIDGE] = {{ 0x01, 0x80, 0xc2, 0x00, 0x00, 0x0e }}, |
| [LLDP_EMIT_NON_TPMR_BRIDGE] = {{ 0x01, 0x80, 0xc2, 0x00, 0x00, 0x03 }}, |
| [LLDP_EMIT_CUSTOMER_BRIDGE] = {{ 0x01, 0x80, 0xc2, 0x00, 0x00, 0x00 }}, |
| }; |
| |
| 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( |
| LLDPEmit mode, |
| 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(mode > LLDP_EMIT_NO); |
| assert(mode < _LLDP_EMIT_MAX); |
| 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, lldp_multicast_addr + mode, ETH_ALEN); |
| memcpy(h->ether_shost, hwaddr, ETH_ALEN); |
| |
| p = (uint8_t*) packet + sizeof(struct ether_header); |
| |
| r = lldp_write_tlv_header(&p, SD_LLDP_TYPE_CHASSIS_ID, 1 + machine_id_length); |
| if (r < 0) |
| return r; |
| *(p++) = SD_LLDP_CHASSIS_SUBTYPE_LOCALLY_ASSIGNED; |
| p = mempcpy(p, machine_id, machine_id_length); |
| |
| r = lldp_write_tlv_header(&p, SD_LLDP_TYPE_PORT_ID, 1 + ifname_length); |
| if (r < 0) |
| return r; |
| *(p++) = SD_LLDP_PORT_SUBTYPE_INTERFACE_NAME; |
| p = mempcpy(p, ifname, ifname_length); |
| |
| r = lldp_write_tlv_header(&p, SD_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, SD_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, SD_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, SD_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, SD_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, SD_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 struct ether_addr *address, |
| 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, |
| }; |
| |
| _cleanup_close_ int fd = -1; |
| ssize_t l; |
| |
| assert(ifindex > 0); |
| assert(address); |
| assert(packet || packet_size <= 0); |
| |
| memcpy(sa.ll.sll_addr, address, ETH_ALEN); |
| |
| 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; |
| |
| assert(link); |
| |
| if (!link->network || link->network->lldp_emit == LLDP_EMIT_NO) |
| return 0; |
| |
| assert(link->network->lldp_emit < _LLDP_EMIT_MAX); |
| |
| 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); |
| |
| assert_cc(LLDP_TX_INTERVAL_USEC * LLDP_TX_HOLD + 1 <= (UINT16_MAX - 1) * USEC_PER_SEC); |
| ttl = DIV_ROUND_UP(LLDP_TX_INTERVAL_USEC * LLDP_TX_HOLD + 1, USEC_PER_SEC); |
| |
| caps = (link->network && link->network->ip_forward != ADDRESS_FAMILY_NO) ? |
| SD_LLDP_SYSTEM_CAPABILITIES_ROUTER : |
| SD_LLDP_SYSTEM_CAPABILITIES_STATION; |
| |
| r = lldp_make_packet(link->network->lldp_emit, |
| &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, |
| SD_LLDP_SYSTEM_CAPABILITIES_STATION|SD_LLDP_SYSTEM_CAPABILITIES_BRIDGE|SD_LLDP_SYSTEM_CAPABILITIES_ROUTER, |
| caps, |
| &packet, &packet_size); |
| if (r < 0) |
| return r; |
| |
| return lldp_send_packet(link->ifindex, lldp_multicast_addr + link->network->lldp_emit, 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_emit_start(Link *link) { |
| usec_t next; |
| int r; |
| |
| assert(link); |
| |
| if (!link->network || link->network->lldp_emit == LLDP_EMIT_NO) { |
| link_lldp_emit_stop(link); |
| return 0; |
| } |
| |
| /* 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_emit_event_source) { |
| usec_t old; |
| |
| /* Lower the timeout, maybe */ |
| r = sd_event_source_get_time(link->lldp_emit_event_source, &old); |
| if (r < 0) |
| return r; |
| |
| if (old <= next) |
| return 0; |
| |
| return sd_event_source_set_time(link->lldp_emit_event_source, next); |
| } else { |
| r = sd_event_add_time( |
| link->manager->event, |
| &link->lldp_emit_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_emit_event_source, "lldp-tx"); |
| } |
| |
| return 0; |
| } |
| |
| void link_lldp_emit_stop(Link *link) { |
| assert(link); |
| |
| link->lldp_emit_event_source = sd_event_source_unref(link->lldp_emit_event_source); |
| } |
| |
| int config_parse_lldp_emit( |
| const char *unit, |
| const char *filename, |
| unsigned line, |
| const char *section, |
| unsigned section_line, |
| const char *lvalue, |
| int ltype, |
| const char *rvalue, |
| void *data, |
| void *userdata) { |
| |
| LLDPEmit *emit = data; |
| int r; |
| |
| assert(filename); |
| assert(lvalue); |
| assert(rvalue); |
| |
| if (isempty(rvalue)) |
| *emit = LLDP_EMIT_NO; |
| else if (streq(rvalue, "nearest-bridge")) |
| *emit = LLDP_EMIT_NEAREST_BRIDGE; |
| else if (streq(rvalue, "non-tpmr-bridge")) |
| *emit = LLDP_EMIT_NON_TPMR_BRIDGE; |
| else if (streq(rvalue, "customer-bridge")) |
| *emit = LLDP_EMIT_CUSTOMER_BRIDGE; |
| else { |
| r = parse_boolean(rvalue); |
| if (r < 0) { |
| log_syntax(unit, LOG_ERR, filename, line, 0, "Failed to parse LLDP emission setting, ignoring: %s", rvalue); |
| return 0; |
| } |
| |
| *emit = r ? LLDP_EMIT_NEAREST_BRIDGE : LLDP_EMIT_NO; |
| } |
| |
| return 0; |
| } |