Files
systemd/src/network/networkd-dhcp-server.c
T
Yu Watanabe c91f8f90ba network: use link_start_dhcp4_server() at one more place
Otherwise, even if the persistent storage is not ready, the DHCP server
may be started e.g. by unplugging and plugging cable.

Follow-up for 5582b36c38.
2024-03-15 02:28:38 +09:00

839 lines
31 KiB
C

/* SPDX-License-Identifier: LGPL-2.1-or-later */
#include <netinet/in.h>
#include <linux/if_arp.h>
#include <linux/if.h>
#include "sd-dhcp-server.h"
#include "dhcp-protocol.h"
#include "fd-util.h"
#include "fileio.h"
#include "network-common.h"
#include "networkd-address.h"
#include "networkd-dhcp-server-bus.h"
#include "networkd-dhcp-server-static-lease.h"
#include "networkd-dhcp-server.h"
#include "networkd-link.h"
#include "networkd-manager.h"
#include "networkd-network.h"
#include "networkd-queue.h"
#include "networkd-route-util.h"
#include "parse-util.h"
#include "path-util.h"
#include "socket-netlink.h"
#include "string-table.h"
#include "string-util.h"
#include "strv.h"
static bool link_dhcp4_server_enabled(Link *link) {
assert(link);
if (link->flags & IFF_LOOPBACK)
return false;
if (!link->network)
return false;
if (link->iftype == ARPHRD_CAN)
return false;
return link->network->dhcp_server;
}
int network_adjust_dhcp_server(Network *network, Set **addresses) {
int r;
assert(network);
assert(addresses);
if (!network->dhcp_server)
return 0;
if (network->bond) {
log_warning("%s: DHCPServer= is enabled for bond slave. Disabling DHCP server.",
network->filename);
network->dhcp_server = false;
return 0;
}
assert(network->dhcp_server_address_prefixlen <= 32);
if (network->dhcp_server_address_prefixlen == 0) {
Address *address;
/* If the server address is not specified, then find suitable static address. */
ORDERED_HASHMAP_FOREACH(address, network->addresses_by_section) {
assert(!section_is_invalid(address->section));
if (address->family != AF_INET)
continue;
if (in4_addr_is_localhost(&address->in_addr.in))
continue;
if (in4_addr_is_link_local(&address->in_addr.in))
continue;
if (in4_addr_is_set(&address->in_addr_peer.in))
continue;
/* TODO: check if the prefix length is small enough for the pool. */
network->dhcp_server_address = address;
break;
}
if (!network->dhcp_server_address) {
log_warning("%s: DHCPServer= is enabled, but no suitable static address configured. "
"Disabling DHCP server.",
network->filename);
network->dhcp_server = false;
return 0;
}
} else {
_cleanup_(address_unrefp) Address *a = NULL;
Address *existing;
unsigned line;
/* TODO: check if the prefix length is small enough for the pool. */
/* If an address is explicitly specified, then check if the corresponding [Address] section
* is configured, and add one if not. */
existing = set_get(*addresses,
&(Address) {
.family = AF_INET,
.in_addr.in = network->dhcp_server_address_in_addr,
.prefixlen = network->dhcp_server_address_prefixlen,
});
if (existing) {
/* Corresponding [Address] section already exists. */
network->dhcp_server_address = existing;
return 0;
}
r = ordered_hashmap_by_section_find_unused_line(network->addresses_by_section, network->filename, &line);
if (r < 0)
return log_warning_errno(r, "%s: Failed to find unused line number for DHCP server address: %m",
network->filename);
r = address_new_static(network, network->filename, line, &a);
if (r < 0)
return log_warning_errno(r, "%s: Failed to add new static address object for DHCP server: %m",
network->filename);
a->family = AF_INET;
a->prefixlen = network->dhcp_server_address_prefixlen;
a->in_addr.in = network->dhcp_server_address_in_addr;
a->requested_as_null = !in4_addr_is_set(&network->dhcp_server_address_in_addr);
r = address_section_verify(a);
if (r < 0)
return r;
r = set_ensure_put(addresses, &address_hash_ops, a);
if (r < 0)
return log_oom();
assert(r > 0);
network->dhcp_server_address = TAKE_PTR(a);
}
return 0;
}
int link_start_dhcp4_server(Link *link) {
int r;
assert(link);
assert(link->manager);
if (!link->dhcp_server)
return 0; /* Not configured yet. */
if (!link_has_carrier(link))
return 0;
/* TODO: Maybe, also check the system time is synced. If the system does not have RTC battery, then
* the realtime clock in not usable in the early boot stage, and all saved leases may be wrongly
* handled as expired and dropped. */
if (!sd_dhcp_server_is_in_relay_mode(link->dhcp_server) &&
!link->manager->persistent_storage_is_ready)
return 0;
r = sd_dhcp_server_start(link->dhcp_server);
if (r < 0)
return r;
log_link_debug(link, "Offering DHCPv4 leases");
return 0;
}
void manager_toggle_dhcp4_server_state(Manager *manager, bool start) {
Link *link;
int r;
assert(manager);
HASHMAP_FOREACH(link, manager->links_by_index) {
if (!link->dhcp_server)
continue;
if (sd_dhcp_server_is_in_relay_mode(link->dhcp_server))
continue;
if (start)
r = link_start_dhcp4_server(link);
else
r = sd_dhcp_server_stop(link->dhcp_server);
if (r < 0)
log_link_debug_errno(link, r, "Failed to %s DHCP server, ignoring: %m",
start ? "start" : "stop");
}
}
static int dhcp_server_find_uplink(Link *link, Link **ret) {
assert(link);
if (link->network->dhcp_server_uplink_name)
return link_get_by_name(link->manager, link->network->dhcp_server_uplink_name, ret);
if (link->network->dhcp_server_uplink_index > 0)
return link_get_by_index(link->manager, link->network->dhcp_server_uplink_index, ret);
if (link->network->dhcp_server_uplink_index == UPLINK_INDEX_AUTO) {
/* It is not necessary to propagate error in automatic selection. */
if (manager_find_uplink(link->manager, AF_INET, link, ret) < 0)
*ret = NULL;
return 0;
}
*ret = NULL;
return 0;
}
static int link_push_uplink_to_dhcp_server(
Link *link,
sd_dhcp_lease_server_type_t what,
sd_dhcp_server *s) {
_cleanup_free_ struct in_addr *addresses = NULL;
bool use_dhcp_lease_data = true;
size_t n_addresses = 0;
assert(link);
if (!link->network)
return 0;
assert(link->network);
log_link_debug(link, "Copying %s from link", dhcp_lease_server_type_to_string(what));
switch (what) {
case SD_DHCP_LEASE_DNS:
/* For DNS we have a special case. We the data configured explicitly locally along with the
* data from the DHCP lease. */
for (unsigned i = 0; i < link->network->n_dns; i++) {
struct in_addr ia;
/* Only look for IPv4 addresses */
if (link->network->dns[i]->family != AF_INET)
continue;
ia = link->network->dns[i]->address.in;
/* Never propagate obviously borked data */
if (in4_addr_is_null(&ia) || in4_addr_is_localhost(&ia))
continue;
if (!GREEDY_REALLOC(addresses, n_addresses + 1))
return log_oom();
addresses[n_addresses++] = ia;
}
use_dhcp_lease_data = link->network->dhcp_use_dns;
break;
case SD_DHCP_LEASE_NTP: {
/* For NTP things are similar, but for NTP hostnames can be configured too, which we cannot
* propagate via DHCP. Hence let's only propagate those which are IP addresses. */
STRV_FOREACH(i, link->network->ntp) {
union in_addr_union ia;
if (in_addr_from_string(AF_INET, *i, &ia) < 0)
continue;
/* Never propagate obviously borked data */
if (in4_addr_is_null(&ia.in) || in4_addr_is_localhost(&ia.in))
continue;
if (!GREEDY_REALLOC(addresses, n_addresses + 1))
return log_oom();
addresses[n_addresses++] = ia.in;
}
use_dhcp_lease_data = link->network->dhcp_use_ntp;
break;
}
case SD_DHCP_LEASE_SIP:
/* For SIP we don't allow explicit, local configuration, but there's control whether to use the data */
use_dhcp_lease_data = link->network->dhcp_use_sip;
break;
case SD_DHCP_LEASE_POP3:
case SD_DHCP_LEASE_SMTP:
case SD_DHCP_LEASE_LPR:
/* For the other server types we currently do not allow local configuration of server data,
* since there are typically no local consumers of the data. */
break;
default:
assert_not_reached();
}
if (use_dhcp_lease_data && link->dhcp_lease) {
const struct in_addr *da;
int n = sd_dhcp_lease_get_servers(link->dhcp_lease, what, &da);
if (n > 0) {
if (!GREEDY_REALLOC(addresses, n_addresses + n))
return log_oom();
for (int j = 0; j < n; j++)
if (in4_addr_is_non_local(&da[j]))
addresses[n_addresses++] = da[j];
}
}
if (n_addresses <= 0)
return 0;
return sd_dhcp_server_set_servers(s, what, addresses, n_addresses);
}
static int dhcp4_server_parse_dns_server_string_and_warn(
const char *string,
struct in_addr **addresses,
size_t *n_addresses) {
for (;;) {
_cleanup_free_ char *word = NULL, *server_name = NULL;
union in_addr_union address;
int family, r, ifindex = 0;
r = extract_first_word(&string, &word, NULL, 0);
if (r < 0)
return r;
if (r == 0)
break;
r = in_addr_ifindex_name_from_string_auto(word, &family, &address, &ifindex, &server_name);
if (r < 0) {
log_warning_errno(r, "Failed to parse DNS server address '%s', ignoring: %m", word);
continue;
}
/* Only look for IPv4 addresses */
if (family != AF_INET)
continue;
/* Never propagate obviously borked data */
if (in4_addr_is_null(&address.in) || in4_addr_is_localhost(&address.in))
continue;
if (!GREEDY_REALLOC(*addresses, *n_addresses + 1))
return log_oom();
(*addresses)[(*n_addresses)++] = address.in;
}
return 0;
}
static int dhcp4_server_set_dns_from_resolve_conf(Link *link) {
_cleanup_free_ struct in_addr *addresses = NULL;
_cleanup_fclose_ FILE *f = NULL;
size_t n_addresses = 0;
int r;
f = fopen(PRIVATE_UPLINK_RESOLV_CONF, "re");
if (!f) {
if (errno == ENOENT)
return 0;
return log_warning_errno(errno, "Failed to open " PRIVATE_UPLINK_RESOLV_CONF ": %m");
}
for (;;) {
_cleanup_free_ char *line = NULL;
const char *a;
r = read_stripped_line(f, LONG_LINE_MAX, &line);
if (r < 0)
return log_error_errno(r, "Failed to read " PRIVATE_UPLINK_RESOLV_CONF ": %m");
if (r == 0)
break;
if (IN_SET(*line, '#', ';', 0))
continue;
a = first_word(line, "nameserver");
if (!a)
continue;
r = dhcp4_server_parse_dns_server_string_and_warn(a, &addresses, &n_addresses);
if (r < 0)
log_warning_errno(r, "Failed to parse DNS server address '%s', ignoring.", a);
}
if (n_addresses <= 0)
return 0;
return sd_dhcp_server_set_dns(link->dhcp_server, addresses, n_addresses);
}
static int dhcp4_server_configure(Link *link) {
bool acquired_uplink = false;
sd_dhcp_option *p;
DHCPStaticLease *static_lease;
Link *uplink = NULL;
Address *address;
bool bind_to_interface;
int r;
assert(link);
assert(link->network);
assert(link->network->dhcp_server_address);
log_link_debug(link, "Configuring DHCP Server.");
if (link->dhcp_server)
return -EBUSY;
r = sd_dhcp_server_new(&link->dhcp_server, link->ifindex);
if (r < 0)
return r;
r = sd_dhcp_server_attach_event(link->dhcp_server, link->manager->event, 0);
if (r < 0)
return r;
r = sd_dhcp_server_set_callback(link->dhcp_server, dhcp_server_callback, link);
if (r < 0)
return log_link_warning_errno(link, r, "Failed to set callback for DHCPv4 server instance: %m");
r = address_get(link, link->network->dhcp_server_address, &address);
if (r < 0)
return log_link_error_errno(link, r, "Failed to find suitable address for DHCPv4 server instance: %m");
/* use the server address' subnet as the pool */
r = sd_dhcp_server_configure_pool(link->dhcp_server, &address->in_addr.in, address->prefixlen,
link->network->dhcp_server_pool_offset, link->network->dhcp_server_pool_size);
if (r < 0)
return log_link_error_errno(link, r, "Failed to configure address pool for DHCPv4 server instance: %m");
if (link->network->dhcp_server_max_lease_time_usec > 0) {
r = sd_dhcp_server_set_max_lease_time(link->dhcp_server, link->network->dhcp_server_max_lease_time_usec);
if (r < 0)
return log_link_error_errno(link, r, "Failed to set maximum lease time for DHCPv4 server instance: %m");
}
if (link->network->dhcp_server_default_lease_time_usec > 0) {
r = sd_dhcp_server_set_default_lease_time(link->dhcp_server, link->network->dhcp_server_default_lease_time_usec);
if (r < 0)
return log_link_error_errno(link, r, "Failed to set default lease time for DHCPv4 server instance: %m");
}
r = sd_dhcp_server_set_ipv6_only_preferred_usec(link->dhcp_server, link->network->dhcp_server_ipv6_only_preferred_usec);
if (r < 0)
return log_link_error_errno(link, r, "Failed to set IPv6 only preferred time for DHCPv4 server instance: %m");
r = sd_dhcp_server_set_boot_server_address(link->dhcp_server, &link->network->dhcp_server_boot_server_address);
if (r < 0)
return log_link_warning_errno(link, r, "Failed to set boot server address for DHCPv4 server instance: %m");
r = sd_dhcp_server_set_boot_server_name(link->dhcp_server, link->network->dhcp_server_boot_server_name);
if (r < 0)
return log_link_warning_errno(link, r, "Failed to set boot server name for DHCPv4 server instance: %m");
r = sd_dhcp_server_set_boot_filename(link->dhcp_server, link->network->dhcp_server_boot_filename);
if (r < 0)
return log_link_warning_errno(link, r, "Failed to set boot filename for DHCPv4 server instance: %m");
r = sd_dhcp_server_set_rapid_commit(link->dhcp_server, link->network->dhcp_server_rapid_commit);
if (r < 0)
return log_link_warning_errno(link, r, "Failed to %s Rapid Commit support for DHCPv4 server instance: %m",
enable_disable(link->network->dhcp_server_rapid_commit));
for (sd_dhcp_lease_server_type_t type = 0; type < _SD_DHCP_LEASE_SERVER_TYPE_MAX; type++) {
if (!link->network->dhcp_server_emit[type].emit)
continue;
if (link->network->dhcp_server_emit[type].n_addresses > 0)
/* Explicitly specified servers to emit */
r = sd_dhcp_server_set_servers(
link->dhcp_server,
type,
link->network->dhcp_server_emit[type].addresses,
link->network->dhcp_server_emit[type].n_addresses);
else {
/* Emission is requested, but nothing explicitly configured. Let's find a suitable upling */
if (!acquired_uplink) {
(void) dhcp_server_find_uplink(link, &uplink);
acquired_uplink = true;
}
if (uplink && uplink->network)
r = link_push_uplink_to_dhcp_server(uplink, type, link->dhcp_server);
else if (type == SD_DHCP_LEASE_DNS)
r = dhcp4_server_set_dns_from_resolve_conf(link);
else {
log_link_debug(link,
"Not emitting %s on link, couldn't find suitable uplink.",
dhcp_lease_server_type_to_string(type));
continue;
}
}
if (r < 0)
log_link_warning_errno(link, r,
"Failed to set %s for DHCP server, ignoring: %m",
dhcp_lease_server_type_to_string(type));
}
if (link->network->dhcp_server_emit_router) {
r = sd_dhcp_server_set_router(link->dhcp_server, &link->network->dhcp_server_router);
if (r < 0)
return log_link_error_errno(link, r, "Failed to set router address for DHCP server: %m");
}
r = sd_dhcp_server_set_relay_target(link->dhcp_server, &link->network->dhcp_server_relay_target);
if (r < 0)
return log_link_error_errno(link, r, "Failed to set relay target for DHCP server: %m");
bind_to_interface = sd_dhcp_server_is_in_relay_mode(link->dhcp_server) ? false : link->network->dhcp_server_bind_to_interface;
r = sd_dhcp_server_set_bind_to_interface(link->dhcp_server, bind_to_interface);
if (r < 0)
return log_link_error_errno(link, r, "Failed to set interface binding for DHCP server: %m");
r = sd_dhcp_server_set_relay_agent_information(link->dhcp_server, link->network->dhcp_server_relay_agent_circuit_id, link->network->dhcp_server_relay_agent_remote_id);
if (r < 0)
return log_link_error_errno(link, r, "Failed to set agent circuit/remote id for DHCP server: %m");
if (link->network->dhcp_server_emit_timezone) {
_cleanup_free_ char *buffer = NULL;
const char *tz = NULL;
if (link->network->dhcp_server_timezone)
tz = link->network->dhcp_server_timezone;
else {
r = get_timezone(&buffer);
if (r < 0)
log_link_warning_errno(link, r, "Failed to determine timezone, not sending timezone: %m");
else
tz = buffer;
}
if (tz) {
r = sd_dhcp_server_set_timezone(link->dhcp_server, tz);
if (r < 0)
return log_link_error_errno(link, r, "Failed to set timezone for DHCP server: %m");
}
}
ORDERED_HASHMAP_FOREACH(p, link->network->dhcp_server_send_options) {
r = sd_dhcp_server_add_option(link->dhcp_server, p);
if (r == -EEXIST)
continue;
if (r < 0)
return log_link_error_errno(link, r, "Failed to set DHCPv4 option: %m");
}
ORDERED_HASHMAP_FOREACH(p, link->network->dhcp_server_send_vendor_options) {
r = sd_dhcp_server_add_vendor_option(link->dhcp_server, p);
if (r == -EEXIST)
continue;
if (r < 0)
return log_link_error_errno(link, r, "Failed to set DHCPv4 option: %m");
}
HASHMAP_FOREACH(static_lease, link->network->dhcp_static_leases_by_section) {
r = sd_dhcp_server_set_static_lease(link->dhcp_server, &static_lease->address, static_lease->client_id, static_lease->client_id_size);
if (r < 0)
return log_link_error_errno(link, r, "Failed to set DHCPv4 static lease for DHCP server: %m");
}
if (!sd_dhcp_server_is_in_relay_mode(link->dhcp_server)) {
_cleanup_free_ char *lease_file = path_join("/var/lib/systemd/network/dhcp-server-lease/", link->ifname);
if (!lease_file)
return log_oom();
r = sd_dhcp_server_set_lease_file(link->dhcp_server, lease_file);
if (r < 0)
log_link_warning_errno(link, r, "Failed to load DHCPv4 server leases, ignoring: %m");
}
r = link_start_dhcp4_server(link);
if (r < 0)
return log_link_error_errno(link, r, "Could not start DHCPv4 server instance: %m");
return 0;
}
static bool dhcp_server_is_ready_to_configure(Link *link) {
Link *uplink = NULL;
Address *a;
assert(link);
assert(link->network);
assert(link->network->dhcp_server_address);
if (!link_is_ready_to_configure(link, /* allow_unmanaged = */ false))
return false;
if (!link_has_carrier(link))
return false;
if (!link->static_addresses_configured)
return false;
if (address_get(link, link->network->dhcp_server_address, &a) < 0)
return false;
if (!address_is_ready(a))
return false;
if (dhcp_server_find_uplink(link, &uplink) < 0)
return false;
if (uplink && !uplink->network)
return false;
return true;
}
static int dhcp_server_process_request(Request *req, Link *link, void *userdata) {
int r;
assert(link);
if (!dhcp_server_is_ready_to_configure(link))
return 0;
r = dhcp4_server_configure(link);
if (r < 0)
return log_link_warning_errno(link, r, "Failed to configure DHCP server: %m");
return 1;
}
int link_request_dhcp_server(Link *link) {
int r;
assert(link);
if (!link_dhcp4_server_enabled(link))
return 0;
if (link->dhcp_server)
return 0;
log_link_debug(link, "Requesting DHCP server.");
r = link_queue_request(link, REQUEST_TYPE_DHCP_SERVER, dhcp_server_process_request, NULL);
if (r < 0)
return log_link_warning_errno(link, r, "Failed to request configuration of DHCP server: %m");
return 0;
}
int config_parse_dhcp_server_relay_agent_suboption(
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) {
char **suboption_value = data;
char* p;
assert(filename);
assert(lvalue);
assert(rvalue);
if (isempty(rvalue)) {
*suboption_value = mfree(*suboption_value);
return 0;
}
p = startswith(rvalue, "string:");
if (!p) {
log_syntax(unit, LOG_WARNING, filename, line, 0,
"Failed to parse %s=%s'. Invalid format, ignoring.", lvalue, rvalue);
return 0;
}
return free_and_strdup(suboption_value, empty_to_null(p));
}
int config_parse_dhcp_server_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) {
NetworkDHCPServerEmitAddress *emit = ASSERT_PTR(data);
assert(rvalue);
if (isempty(rvalue)) {
emit->addresses = mfree(emit->addresses);
emit->n_addresses = 0;
return 0;
}
for (const char *p = rvalue;;) {
_cleanup_free_ char *w = NULL;
union in_addr_union a;
int r;
r = extract_first_word(&p, &w, NULL, 0);
if (r == -ENOMEM)
return log_oom();
if (r < 0) {
log_syntax(unit, LOG_WARNING, filename, line, r,
"Failed to extract word, ignoring: %s", rvalue);
return 0;
}
if (r == 0)
return 0;
if (streq(w, "_server_address"))
a = IN_ADDR_NULL; /* null address will be converted to the server address. */
else {
r = in_addr_from_string(AF_INET, w, &a);
if (r < 0) {
log_syntax(unit, LOG_WARNING, filename, line, r,
"Failed to parse %s= address '%s', ignoring: %m", lvalue, w);
continue;
}
if (in4_addr_is_null(&a.in)) {
log_syntax(unit, LOG_WARNING, filename, line, 0,
"Found a null address in %s=, ignoring.", lvalue);
continue;
}
}
if (!GREEDY_REALLOC(emit->addresses, emit->n_addresses + 1))
return log_oom();
emit->addresses[emit->n_addresses++] = a.in;
}
}
int config_parse_dhcp_server_address(
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) {
Network *network = ASSERT_PTR(userdata);
union in_addr_union a;
unsigned char prefixlen;
int r;
assert(filename);
assert(lvalue);
assert(rvalue);
if (isempty(rvalue)) {
network->dhcp_server_address_in_addr = (struct in_addr) {};
network->dhcp_server_address_prefixlen = 0;
return 0;
}
r = in_addr_prefix_from_string(rvalue, AF_INET, &a, &prefixlen);
if (r < 0) {
log_syntax(unit, LOG_WARNING, filename, line, r,
"Failed to parse %s=, ignoring assignment: %s", lvalue, rvalue);
return 0;
}
if (in4_addr_is_localhost(&a.in) || in4_addr_is_link_local(&a.in)) {
log_syntax(unit, LOG_WARNING, filename, line, 0,
"DHCP server address cannot be a localhost or link-local address, "
"ignoring assignment: %s", rvalue);
return 0;
}
network->dhcp_server_address_in_addr = a.in;
network->dhcp_server_address_prefixlen = prefixlen;
return 0;
}
int config_parse_dhcp_server_ipv6_only_preferred(
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) {
usec_t t, *usec = ASSERT_PTR(data);
int r;
assert(filename);
assert(section);
assert(lvalue);
assert(rvalue);
if (isempty(rvalue)) {
*usec = 0;
return 0;
}
r = parse_sec(rvalue, &t);
if (r < 0) {
log_syntax(unit, LOG_WARNING, filename, line, r,
"Failed to parse [%s] %s=, ignoring assignment: %s", section, lvalue, rvalue);
return 0;
}
if (t < MIN_V6ONLY_WAIT_USEC && !network_test_mode_enabled()) {
log_syntax(unit, LOG_WARNING, filename, line, 0,
"Invalid [%s] %s=, ignoring assignment: %s", section, lvalue, rvalue);
return 0;
}
*usec = t;
return 0;
}