static int dhcp4_set_hostname(Link *link) {
_cleanup_free_ char *hostname = NULL;
const char *hn;
int r;
assert(link);
if (!link->network->dhcp_send_hostname)
hn = NULL;
else if (link->network->dhcp_hostname)
hn = link->network->dhcp_hostname;
else {
r = gethostname_strict(&hostname);
if (r < 0 && r != -ENXIO) /* ENXIO: no hostname set or hostname is "localhost" */
return r;
hn = hostname;
}
r = sd_dhcp_client_set_hostname(link->dhcp_client, hn);
if (r == -EINVAL && hostname)
/* Ignore error when the machine's hostname is not suitable to send in DHCP packet. */
log_link_warning_errno(link, r, "DHCP4 CLIENT: Failed to set hostname from kernel hostname, ignoring: %m");
else if (r < 0)
return log_link_error_errno(link, r, "DHCP4 CLIENT: Failed to set hostname: %m");
return 0;
}
static int dhcp4_set_hostname(Link *link) {
_cleanup_free_ char *hostname = NULL;
const char *hn;
int r;
assert(link);
if (!link->network->dhcp_send_hostname)
hn = NULL;
else if (link->network->dhcp_hostname)
hn = link->network->dhcp_hostname;
else {
r = gethostname_strict(&hostname);
if (r < 0 && r != -ENXIO) /* ENXIO: no hostname set or hostname is "localhost" */
return r;
hn = hostname;
}
return sd_dhcp_client_set_hostname(link->dhcp_client, hn);
}
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);
}
