--- /dev/null
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+
+#include <arpa/inet.h>
+#include <linux/sockios.h>
+#include <sys/ioctl.h>
+
+#include "sd-event.h"
+#include "sd-id128.h"
+#include "sd-lldp-tx.h"
+
+#include "alloc-util.h"
+#include "ether-addr-util.h"
+#include "fd-util.h"
+#include "hostname-util.h"
+#include "log-link.h"
+#include "network-common.h"
+#include "random-util.h"
+#include "socket-util.h"
+#include "string-util.h"
+#include "time-util.h"
+#include "unaligned.h"
+#include "web-util.h"
+
+/* The LLDP spec calls this "txFastInit", see 9.2.5.19 */
+#define LLDP_FAST_TX_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_TX_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_TX_JITTER_USEC / 2)
+
+/* The LLDP spec calls this msgFastTx, but we subtract half the jitter off it. */
+#define LLDP_FAST_TX_INTERVAL_USEC (1U * USEC_PER_SEC - LLDP_TX_JITTER_USEC / 2)
+
+#define LLDP_TX_TTL ((uint16_t) DIV_ROUND_UP(LLDP_TX_INTERVAL_USEC * LLDP_TX_HOLD + 1, USEC_PER_SEC))
+
+static const struct ether_addr lldp_multicast_addr[_SD_LLDP_MULTICAST_MODE_MAX] = {
+ [SD_LLDP_MULTICAST_MODE_NEAREST_BRIDGE] = {{ 0x01, 0x80, 0xc2, 0x00, 0x00, 0x0e }},
+ [SD_LLDP_MULTICAST_MODE_NON_TPMR_BRIDGE] = {{ 0x01, 0x80, 0xc2, 0x00, 0x00, 0x03 }},
+ [SD_LLDP_MULTICAST_MODE_CUSTOMER_BRIDGE] = {{ 0x01, 0x80, 0xc2, 0x00, 0x00, 0x00 }},
+};
+
+struct sd_lldp_tx {
+ unsigned n_ref;
+
+ int ifindex;
+ char *ifname;
+
+ sd_event *event;
+ int64_t event_priority;
+ sd_event_source *timer_event_source;
+
+ unsigned fast_tx;
+
+ sd_lldp_multicast_mode_t mode;
+ struct ether_addr hwaddr;
+
+ char *port_description;
+ char *hostname;
+ char *pretty_hostname;
+ char *mud_url;
+ uint16_t supported_capabilities;
+ uint16_t enabled_capabilities;
+};
+
+#define log_lldp_tx_errno(lldp_tx, error, fmt, ...) \
+ log_interface_prefix_full_errno( \
+ "LLDP Tx: ", \
+ sd_lldp_tx_get_ifname(lldp_tx), \
+ error, fmt, ##__VA_ARGS__)
+#define log_lldp_tx(lldp_tx, fmt, ...) \
+ log_interface_prefix_full_errno_zerook( \
+ "LLDP Tx: ", \
+ sd_lldp_tx_get_ifname(lldp_tx), \
+ 0, fmt, ##__VA_ARGS__)
+
+static sd_lldp_tx *lldp_tx_free(sd_lldp_tx *lldp_tx) {
+ if (!lldp_tx)
+ return NULL;
+
+ sd_lldp_tx_detach_event(lldp_tx);
+
+ free(lldp_tx->port_description);
+ free(lldp_tx->hostname);
+ free(lldp_tx->pretty_hostname);
+ free(lldp_tx->mud_url);
+
+ free(lldp_tx->ifname);
+ return mfree(lldp_tx);
+}
+
+DEFINE_PUBLIC_TRIVIAL_REF_UNREF_FUNC(sd_lldp_tx, sd_lldp_tx, lldp_tx_free);
+
+int sd_lldp_tx_new(sd_lldp_tx **ret) {
+ _cleanup_(sd_lldp_tx_unrefp) sd_lldp_tx *lldp_tx = NULL;
+
+ assert_return(ret, -EINVAL);
+
+ lldp_tx = new(sd_lldp_tx, 1);
+ if (!lldp_tx)
+ return -ENOMEM;
+
+ *lldp_tx = (sd_lldp_tx) {
+ .n_ref = 1,
+ .mode = _SD_LLDP_MULTICAST_MODE_INVALID,
+ };
+
+ *ret = TAKE_PTR(lldp_tx);
+ return 0;
+}
+
+int sd_lldp_tx_set_ifindex(sd_lldp_tx *lldp_tx, int ifindex) {
+ assert_return(lldp_tx, -EINVAL);
+ assert_return(ifindex > 0, -EINVAL);
+
+ lldp_tx->ifindex = ifindex;
+ return 0;
+}
+
+int sd_lldp_tx_set_ifname(sd_lldp_tx *lldp_tx, const char *ifname) {
+ assert_return(lldp_tx, -EINVAL);
+ assert_return(ifname, -EINVAL);
+
+ if (!ifname_valid_full(ifname, IFNAME_VALID_ALTERNATIVE))
+ return -EINVAL;
+
+ return free_and_strdup(&lldp_tx->ifname, ifname);
+}
+
+const char *sd_lldp_tx_get_ifname(sd_lldp_tx *lldp_tx) {
+ if (!lldp_tx)
+ return NULL;
+
+ return get_ifname(lldp_tx->ifindex, &lldp_tx->ifname);
+}
+
+int sd_lldp_tx_set_multicast_mode(sd_lldp_tx *lldp_tx, sd_lldp_multicast_mode_t mode) {
+ assert_return(lldp_tx, -EINVAL);
+ assert_return(mode >= 0 && mode < _SD_LLDP_MULTICAST_MODE_MAX, -EINVAL);
+
+ lldp_tx->mode = mode;
+ return 0;
+}
+
+int sd_lldp_tx_set_hwaddr(sd_lldp_tx *lldp_tx, const struct ether_addr *hwaddr) {
+ assert_return(lldp_tx, -EINVAL);
+ assert_return(!ether_addr_is_null(hwaddr), -EINVAL);
+
+ lldp_tx->hwaddr = *hwaddr;
+ return 0;
+}
+
+int sd_lldp_tx_set_capabilities(sd_lldp_tx *lldp_tx, uint16_t supported, uint16_t enabled) {
+ assert_return(lldp_tx, -EINVAL);
+ assert_return((enabled & ~supported) == 0, -EINVAL);
+
+ lldp_tx->supported_capabilities = supported;
+ lldp_tx->enabled_capabilities = enabled;
+ return 0;
+}
+
+int sd_lldp_tx_set_port_description(sd_lldp_tx *lldp_tx, const char *port_description) {
+ assert_return(lldp_tx, -EINVAL);
+
+ /* An empty string unset the previously set hostname. */
+ if (strlen_ptr(port_description) >= 512)
+ return -EINVAL;
+
+ return free_and_strdup(&lldp_tx->port_description, empty_to_null(port_description));
+}
+
+int sd_lldp_tx_set_hostname(sd_lldp_tx *lldp_tx, const char *hostname) {
+ assert_return(lldp_tx, -EINVAL);
+
+ /* An empty string unset the previously set hostname. */
+ if (!isempty(hostname)) {
+ assert_cc(HOST_NAME_MAX < 512);
+
+ if (!hostname_is_valid(hostname, 0))
+ return -EINVAL;
+ }
+
+ return free_and_strdup(&lldp_tx->hostname, empty_to_null(hostname));
+}
+
+int sd_lldp_tx_set_pretty_hostname(sd_lldp_tx *lldp_tx, const char *pretty_hostname) {
+ assert_return(lldp_tx, -EINVAL);
+
+ /* An empty string unset the previously set hostname. */
+ if (strlen_ptr(pretty_hostname) >= 512)
+ return -EINVAL;
+
+ return free_and_strdup(&lldp_tx->pretty_hostname, empty_to_null(pretty_hostname));
+}
+
+int sd_lldp_tx_set_mud_url(sd_lldp_tx *lldp_tx, const char *mud_url) {
+ assert_return(lldp_tx, -EINVAL);
+
+ /* An empty string unset the previously set hostname. */
+ if (!isempty(mud_url)) {
+ /* Unless the maximum length of each value is 511, the MUD url must be smaller than 256.
+ * See RFC 8520. */
+ if (strlen(mud_url) >= 256)
+ return -EINVAL;
+
+ if (!http_url_is_valid(mud_url))
+ return -EINVAL;
+ }
+
+ return free_and_strdup(&lldp_tx->mud_url, empty_to_null(mud_url));
+}
+
+static size_t lldp_tx_calculate_maximum_packet_size(sd_lldp_tx *lldp_tx, const char *hostname, const char *pretty_hostname) {
+ assert(lldp_tx);
+ assert(lldp_tx->ifindex > 0);
+
+ return sizeof(struct ether_header) +
+ /* Chassis ID */
+ 2 + 1 + (SD_ID128_STRING_MAX - 1) +
+ /* Port ID */
+ 2 + 1 + strlen_ptr(sd_lldp_tx_get_ifname(lldp_tx)) +
+ /* Port description */
+ 2 + strlen_ptr(lldp_tx->port_description) +
+ /* System name */
+ 2 + strlen_ptr(hostname) +
+ /* System description */
+ 2 + strlen_ptr(pretty_hostname) +
+ /* MUD URL */
+ 2 + sizeof(SD_LLDP_OUI_IANA_MUD) + strlen_ptr(lldp_tx->mud_url) +
+ /* TTL */
+ 2 + 2 +
+ /* System Capabilities */
+ 2 + 4 +
+ /* End */
+ 2;
+}
+
+static int packet_append_tlv_header(uint8_t *packet, size_t packet_size, size_t *offset, uint8_t type, size_t data_len) {
+ assert(packet);
+ assert(offset);
+
+ /*
+ * +--------+--------+--------------
+ * |TLV Type| len | value
+ * |(7 bits)|(9 bits)|(0-511 octets)
+ * +--------+--------+--------------
+ * where:
+ *
+ * len = indicates the length of value
+ */
+
+ /* The type field is 7-bits. */
+ if (type >= 128)
+ return -EINVAL;
+
+ /* The data length field is 9-bits. */
+ if (data_len >= 512)
+ return -EINVAL;
+
+ if (packet_size < 2 + data_len)
+ return -ENOBUFS;
+
+ if (*offset > packet_size - 2 - data_len)
+ return -ENOBUFS;
+
+ packet[(*offset)++] = (type << 1) | !!(data_len >> 8);
+ packet[(*offset)++] = data_len & (size_t) UINT8_MAX;
+
+ return 0;
+}
+
+static int packet_append_prefixed_string(
+ uint8_t *packet,
+ size_t packet_size,
+ size_t *offset,
+ uint8_t type,
+ size_t prefix_len,
+ const void *prefix,
+ const char *str) {
+
+ size_t len;
+ int r;
+
+ assert(packet);
+ assert(offset);
+ assert(prefix_len == 0 || prefix);
+
+ if (isempty(str))
+ return 0;
+
+ len = strlen(str);
+
+ /* Check for overflow */
+ if (len > SIZE_MAX - prefix_len)
+ return -ENOBUFS;
+
+ r = packet_append_tlv_header(packet, packet_size, offset, type, prefix_len + len);
+ if (r < 0)
+ return r;
+
+ memcpy_safe(packet + *offset, prefix, prefix_len);
+ *offset += prefix_len;
+
+ memcpy(packet + *offset, str, len);
+ *offset += len;
+
+ return 0;
+}
+
+static int packet_append_string(
+ uint8_t *packet,
+ size_t packet_size,
+ size_t *offset,
+ uint8_t type,
+ const char *str) {
+
+ return packet_append_prefixed_string(packet, packet_size, offset, type, 0, NULL, str);
+}
+
+static int lldp_tx_create_packet(sd_lldp_tx *lldp_tx, size_t *ret_packet_size, uint8_t **ret_packet) {
+ _cleanup_free_ char *hostname = NULL, *pretty_hostname = NULL;
+ _cleanup_free_ uint8_t *packet = NULL;
+ struct ether_header *header;
+ size_t packet_size, offset;
+ sd_id128_t machine_id;
+ int r;
+
+ assert(lldp_tx);
+ assert(lldp_tx->ifindex > 0);
+ assert(ret_packet_size);
+ assert(ret_packet);
+
+ r = sd_id128_get_machine(&machine_id);
+ if (r < 0)
+ return r;
+
+ if (!lldp_tx->hostname)
+ (void) gethostname_strict(&hostname);
+ if (!lldp_tx->pretty_hostname)
+ (void) get_pretty_hostname(&pretty_hostname);
+
+ packet_size = lldp_tx_calculate_maximum_packet_size(lldp_tx,
+ lldp_tx->hostname ?: hostname,
+ lldp_tx->pretty_hostname ?: pretty_hostname);
+
+ packet = new(uint8_t, packet_size);
+ if (!packet)
+ return -ENOMEM;
+
+ header = (struct ether_header*) packet;
+ header->ether_type = htobe16(ETHERTYPE_LLDP);
+ memcpy(header->ether_dhost, lldp_multicast_addr + lldp_tx->mode, ETH_ALEN);
+ memcpy(header->ether_shost, &lldp_tx->hwaddr, ETH_ALEN);
+
+ offset = sizeof(struct ether_header);
+ r = packet_append_prefixed_string(packet, packet_size, &offset, SD_LLDP_TYPE_CHASSIS_ID,
+ 1, (const uint8_t[]) { SD_LLDP_CHASSIS_SUBTYPE_LOCALLY_ASSIGNED },
+ SD_ID128_TO_STRING(machine_id));
+ if (r < 0)
+ return r;
+
+ r = packet_append_prefixed_string(packet, packet_size, &offset, SD_LLDP_TYPE_PORT_ID,
+ 1, (const uint8_t[]) { SD_LLDP_PORT_SUBTYPE_INTERFACE_NAME },
+ sd_lldp_tx_get_ifname(lldp_tx));
+ if (r < 0)
+ return r;
+
+ r = packet_append_string(packet, packet_size, &offset, SD_LLDP_TYPE_PORT_DESCRIPTION,
+ lldp_tx->port_description);
+ if (r < 0)
+ return r;
+
+ r = packet_append_string(packet, packet_size, &offset, SD_LLDP_TYPE_SYSTEM_NAME,
+ lldp_tx->hostname ?: hostname);
+ if (r < 0)
+ return r;
+
+ r = packet_append_string(packet, packet_size, &offset, SD_LLDP_TYPE_SYSTEM_DESCRIPTION,
+ lldp_tx->pretty_hostname ?: pretty_hostname);
+ if (r < 0)
+ return r;
+
+ /* See section 12 of RFC 8520.
+ * +--------+--------+----------+---------+--------------
+ * |TLV Type| len | OUI |subtype | MUDString
+ * | =127 | |= 00 00 5E| = 1 |
+ * |(7 bits)|(9 bits)|(3 octets)|(1 octet)|(1-255 octets)
+ * +--------+--------+----------+---------+--------------
+ * where:
+ *
+ * o TLV Type = 127 indicates a vendor-specific TLV
+ * o len = indicates the TLV string length
+ * o OUI = 00 00 5E is the organizationally unique identifier of IANA
+ * o subtype = 1 (as assigned by IANA for the MUDstring)
+ * o MUDstring = the length MUST NOT exceed 255 octets
+ */
+ r = packet_append_prefixed_string(packet, packet_size, &offset, SD_LLDP_TYPE_PRIVATE,
+ sizeof(SD_LLDP_OUI_IANA_MUD), SD_LLDP_OUI_IANA_MUD,
+ lldp_tx->mud_url);
+ if (r < 0)
+ return r;
+
+ r = packet_append_tlv_header(packet, packet_size, &offset, SD_LLDP_TYPE_TTL, 2);
+ if (r < 0)
+ return r;
+
+ unaligned_write_be16(packet + offset, LLDP_TX_TTL);
+ offset += 2;
+
+ r = packet_append_tlv_header(packet, packet_size, &offset, SD_LLDP_TYPE_SYSTEM_CAPABILITIES, 4);
+ if (r < 0)
+ return r;
+
+ unaligned_write_be16(packet + offset, lldp_tx->supported_capabilities);
+ offset += 2;
+ unaligned_write_be16(packet + offset, lldp_tx->enabled_capabilities);
+ offset += 2;
+
+ r = packet_append_tlv_header(packet, packet_size, &offset, SD_LLDP_TYPE_END, 0);
+ if (r < 0)
+ return r;
+
+ *ret_packet_size = offset;
+ *ret_packet = TAKE_PTR(packet);
+ return 0;
+}
+
+static int lldp_tx_send_packet(sd_lldp_tx *lldp_tx, size_t packet_size, const uint8_t *packet) {
+ _cleanup_close_ int fd = -1;
+ union sockaddr_union sa;
+ ssize_t l;
+
+ assert(lldp_tx);
+ assert(lldp_tx->ifindex > 0);
+ assert(packet_size > sizeof(struct ether_header));
+ assert(packet);
+
+ sa = (union sockaddr_union) {
+ .ll.sll_family = AF_PACKET,
+ .ll.sll_protocol = htobe16(ETHERTYPE_LLDP),
+ .ll.sll_ifindex = lldp_tx->ifindex,
+ .ll.sll_halen = ETH_ALEN,
+ };
+ memcpy(sa.ll.sll_addr, lldp_multicast_addr + lldp_tx->mode, ETH_ALEN);
+
+ fd = socket(AF_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 lldp_tx_send(sd_lldp_tx *lldp_tx) {
+ _cleanup_free_ uint8_t *packet = NULL;
+ size_t packet_size = 0; /* avoid false maybe-uninitialized warning */
+ int r;
+
+ assert(lldp_tx);
+
+ r = lldp_tx_create_packet(lldp_tx, &packet_size, &packet);
+ if (r < 0)
+ return r;
+
+ return lldp_tx_send_packet(lldp_tx, packet_size, packet);
+}
+
+int sd_lldp_tx_attach_event(sd_lldp_tx *lldp_tx, sd_event *event, int64_t priority) {
+ int r;
+
+ assert_return(lldp_tx, -EINVAL);
+ assert_return(!lldp_tx->event, -EBUSY);
+
+ if (event)
+ lldp_tx->event = sd_event_ref(event);
+ else {
+ r = sd_event_default(&lldp_tx->event);
+ if (r < 0)
+ return r;
+ }
+
+ lldp_tx->event_priority = priority;
+
+ return 0;
+}
+
+int sd_lldp_tx_detach_event(sd_lldp_tx *lldp_tx) {
+ assert_return(lldp_tx, -EINVAL);
+
+ lldp_tx->timer_event_source = sd_event_source_disable_unref(lldp_tx->timer_event_source);
+ lldp_tx->event = sd_event_unref(lldp_tx->event);
+ return 0;
+}
+
+sd_event* sd_lldp_tx_get_event(sd_lldp_tx *lldp_tx) {
+ assert_return(lldp_tx, NULL);
+
+ return lldp_tx->event;
+}
+
+static usec_t lldp_tx_get_delay(sd_lldp_tx *lldp_tx) {
+ assert(lldp_tx);
+
+ return usec_add(lldp_tx->fast_tx > 0 ? LLDP_FAST_TX_INTERVAL_USEC : LLDP_TX_INTERVAL_USEC,
+ (usec_t) random_u64() % LLDP_TX_JITTER_USEC);
+}
+
+static int lldp_tx_reset_timer(sd_lldp_tx *lldp_tx) {
+ usec_t delay;
+ int r;
+
+ assert(lldp_tx);
+ assert(lldp_tx->timer_event_source);
+
+ delay = lldp_tx_get_delay(lldp_tx);
+
+ r = sd_event_source_set_time_relative(lldp_tx->timer_event_source, delay);
+ if (r < 0)
+ return r;
+
+ return sd_event_source_set_enabled(lldp_tx->timer_event_source, SD_EVENT_ONESHOT);
+}
+
+static int on_timer_event(sd_event_source *s, uint64_t usec, void *userdata) {
+ sd_lldp_tx *lldp_tx = userdata;
+ int r;
+
+ assert(lldp_tx);
+
+ r = lldp_tx_send(lldp_tx);
+ if (r < 0)
+ log_lldp_tx_errno(lldp_tx, r, "Failed to send packet, ignoring: %m");
+
+ if (lldp_tx->fast_tx > 0)
+ lldp_tx->fast_tx--;
+
+ r = lldp_tx_reset_timer(lldp_tx);
+ if (r < 0)
+ log_lldp_tx_errno(lldp_tx, r, "Failed to reset timer: %m");
+
+ return 0;
+}
+
+int sd_lldp_tx_is_running(sd_lldp_tx *lldp_tx) {
+ int enabled;
+
+ if (!lldp_tx)
+ return 0;
+
+ if (!lldp_tx->timer_event_source)
+ return 0;
+
+ if (sd_event_source_get_enabled(lldp_tx->timer_event_source, &enabled) < 0)
+ return 0;
+
+ return enabled == SD_EVENT_ONESHOT;
+}
+
+int sd_lldp_tx_stop(sd_lldp_tx *lldp_tx) {
+ if (!lldp_tx)
+ return 0;
+
+ if (!lldp_tx->timer_event_source)
+ return 0;
+
+ (void) sd_event_source_set_enabled(lldp_tx->timer_event_source, SD_EVENT_OFF);
+
+ return 1;
+}
+int sd_lldp_tx_start(sd_lldp_tx *lldp_tx) {
+ usec_t delay;
+ int r;
+
+ assert_return(lldp_tx, -EINVAL);
+ assert_return(lldp_tx->event, -EINVAL);
+ assert_return(lldp_tx->ifindex > 0, -EINVAL);
+ assert_return(lldp_tx->mode >= 0 && lldp_tx->mode < _SD_LLDP_MULTICAST_MODE_MAX, -EINVAL);
+ assert_return(!ether_addr_is_null(&lldp_tx->hwaddr), -EINVAL);
+
+ if (sd_lldp_tx_is_running(lldp_tx))
+ return 0;
+
+ lldp_tx->fast_tx = LLDP_FAST_TX_INIT;
+
+ if (lldp_tx->timer_event_source) {
+ r = lldp_tx_reset_timer(lldp_tx);
+ if (r < 0)
+ return log_lldp_tx_errno(lldp_tx, r, "Failed to re-enable timer: %m");
+
+ return 0;
+ }
+
+ delay = lldp_tx_get_delay(lldp_tx);
+
+ r = sd_event_add_time_relative(lldp_tx->event, &lldp_tx->timer_event_source,
+ clock_boottime_or_monotonic(), delay, 0,
+ on_timer_event, lldp_tx);
+ if (r < 0)
+ return r;
+
+ (void) sd_event_source_set_description(lldp_tx->timer_event_source, "lldp-tx-timer");
+ (void) sd_event_source_set_priority(lldp_tx->timer_event_source, lldp_tx->event_priority);
+
+ return 0;
+}
projects / thirdparty / systemd.git / commitdiff
