networkd-dhcp4.c revision 8eb9058dc1f99a5eb9b8726a978fcc0720837a10
/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
/***
This file is part of systemd.
Copyright 2013-2014 Tom Gundersen <teg@jklm.no>
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 <netinet/ether.h>
#include <linux/if.h>
#include "hostname-util.h"
#include "networkd-link.h"
#include "network-internal.h"
#include "dhcp-lease-internal.h"
static int dhcp4_route_handler(sd_netlink *rtnl, sd_netlink_message *m,
void *userdata) {
_cleanup_link_unref_ Link *link = userdata;
int r;
assert(link);
assert(link->dhcp4_messages);
link->dhcp4_messages --;
r = sd_netlink_message_get_errno(m);
if (r < 0 && r != -EEXIST) {
log_link_error(link, "could not set DHCPv4 route: %s",
strerror(-r));
link_enter_failed(link);
}
if (!link->dhcp4_messages) {
link->dhcp4_configured = true;
link_client_handler(link);
}
return 1;
}
static int link_set_dhcp_routes(Link *link) {
struct in_addr gateway;
struct sd_dhcp_route *static_routes;
int r, n, i;
assert(link);
assert(link->dhcp_lease);
r = sd_dhcp_lease_get_router(link->dhcp_lease, &gateway);
if (r < 0 && r != -ENOENT) {
log_link_warning(link,
"DHCP error: could not get gateway: %s",
strerror(-r));
return r;
}
if (r >= 0) {
struct in_addr address;
_cleanup_route_free_ Route *route = NULL;
_cleanup_route_free_ Route *route_gw = NULL;
r = sd_dhcp_lease_get_address(link->dhcp_lease, &address);
if (r < 0) {
log_link_warning(link,
"DHCP error: could not get address: %s",
strerror(-r));
return r;
}
r = route_new_dynamic(&route, RTPROT_DHCP);
if (r < 0) {
log_link_error(link,
"Could not allocate route: %s",
strerror(-r));
return r;
}
r = route_new_dynamic(&route_gw, RTPROT_DHCP);
if (r < 0) {
log_link_error(link,
"Could not allocate route: %s",
strerror(-r));
return r;
}
/* The dhcp netmask may mask out the gateway. Add an explicit
* route for the gw host so that we can route no matter the
* netmask or existing kernel route tables. */
route_gw->family = AF_INET;
route_gw->dst_addr.in = gateway;
route_gw->dst_prefixlen = 32;
route_gw->prefsrc_addr.in = address;
route_gw->scope = RT_SCOPE_LINK;
route_gw->metrics = link->network->dhcp_route_metric;
r = route_configure(route_gw, link, &dhcp4_route_handler);
if (r < 0) {
log_link_warning(link,
"could not set host route: %s",
strerror(-r));
return r;
}
link->dhcp4_messages ++;
route->family = AF_INET;
route->in_addr.in = gateway;
route->prefsrc_addr.in = address;
route->metrics = link->network->dhcp_route_metric;
r = route_configure(route, link, &dhcp4_route_handler);
if (r < 0) {
log_link_warning(link,
"could not set routes: %s",
strerror(-r));
link_enter_failed(link);
return r;
}
link->dhcp4_messages ++;
}
n = sd_dhcp_lease_get_routes(link->dhcp_lease, &static_routes);
if (n == -ENOENT)
return 0;
if (n < 0) {
log_link_warning(link,
"DHCP error: could not get routes: %s",
strerror(-n));
return n;
}
for (i = 0; i < n; i++) {
_cleanup_route_free_ Route *route = NULL;
r = route_new_dynamic(&route, RTPROT_DHCP);
if (r < 0) {
log_link_error(link, "Could not allocate route: %s",
strerror(-r));
return r;
}
route->family = AF_INET;
route->in_addr.in = static_routes[i].gw_addr;
route->dst_addr.in = static_routes[i].dst_addr;
route->dst_prefixlen = static_routes[i].dst_prefixlen;
route->metrics = link->network->dhcp_route_metric;
r = route_configure(route, link, &dhcp4_route_handler);
if (r < 0) {
log_link_warning(link,
"could not set host route: %s",
strerror(-r));
return r;
}
link->dhcp4_messages ++;
}
return 0;
}
static int dhcp_lease_lost(Link *link) {
_cleanup_address_free_ Address *address = NULL;
struct in_addr addr;
struct in_addr netmask;
struct in_addr gateway;
unsigned prefixlen = 0;
int r;
assert(link);
assert(link->dhcp_lease);
log_link_warning(link, "DHCP lease lost");
if (link->network->dhcp_routes) {
struct sd_dhcp_route *routes;
int n, i;
n = sd_dhcp_lease_get_routes(link->dhcp_lease, &routes);
if (n >= 0) {
for (i = 0; i < n; i++) {
_cleanup_route_free_ Route *route = NULL;
r = route_new_dynamic(&route, RTPROT_UNSPEC);
if (r >= 0) {
route->family = AF_INET;
route->in_addr.in = routes[i].gw_addr;
route->dst_addr.in = routes[i].dst_addr;
route->dst_prefixlen = routes[i].dst_prefixlen;
route_drop(route, link,
&link_route_drop_handler);
}
}
}
}
r = address_new_dynamic(&address);
if (r >= 0) {
r = sd_dhcp_lease_get_router(link->dhcp_lease, &gateway);
if (r >= 0) {
_cleanup_route_free_ Route *route_gw = NULL;
_cleanup_route_free_ Route *route = NULL;
r = route_new_dynamic(&route_gw, RTPROT_UNSPEC);
if (r >= 0) {
route_gw->family = AF_INET;
route_gw->dst_addr.in = gateway;
route_gw->dst_prefixlen = 32;
route_gw->scope = RT_SCOPE_LINK;
route_drop(route_gw, link,
&link_route_drop_handler);
}
r = route_new_dynamic(&route, RTPROT_UNSPEC);
if (r >= 0) {
route->family = AF_INET;
route->in_addr.in = gateway;
route_drop(route, link,
&link_route_drop_handler);
}
}
r = sd_dhcp_lease_get_address(link->dhcp_lease, &addr);
if (r >= 0) {
r = sd_dhcp_lease_get_netmask(link->dhcp_lease, &netmask);
if (r >= 0)
prefixlen = in_addr_netmask_to_prefixlen(&netmask);
address->family = AF_INET;
address->in_addr.in = addr;
address->prefixlen = prefixlen;
address_drop(address, link, &link_address_drop_handler);
}
}
if (link->network->dhcp_mtu) {
uint16_t mtu;
r = sd_dhcp_lease_get_mtu(link->dhcp_lease, &mtu);
if (r >= 0 && link->original_mtu != mtu) {
r = link_set_mtu(link, link->original_mtu);
if (r < 0) {
log_link_warning(link,
"DHCP error: could not reset MTU");
link_enter_failed(link);
return r;
}
}
}
if (link->network->dhcp_hostname) {
const char *hostname = NULL;
if (!link->network->hostname)
r = sd_dhcp_lease_get_hostname(link->dhcp_lease, &hostname);
else
hostname = link->network->hostname;
if (r >= 0 || hostname) {
r = link_set_hostname(link, hostname);
if (r < 0)
log_link_error_errno(link, r,
"Failed to set transient hostname to '%s': %m",
hostname);
}
}
link->dhcp_lease = sd_dhcp_lease_unref(link->dhcp_lease);
link->dhcp4_configured = false;
return 0;
}
static int dhcp4_address_handler(sd_netlink *rtnl, sd_netlink_message *m,
void *userdata) {
_cleanup_link_unref_ Link *link = userdata;
int r;
assert(link);
r = sd_netlink_message_get_errno(m);
if (r < 0 && r != -EEXIST) {
log_link_error(link, "could not set DHCPv4 address: %s",
strerror(-r));
link_enter_failed(link);
} else if (r >= 0)
link_rtnl_process_address(rtnl, m, link->manager);
link_set_dhcp_routes(link);
return 1;
}
static int dhcp4_update_address(Link *link,
struct in_addr *address,
struct in_addr *netmask,
uint32_t lifetime) {
_cleanup_address_free_ Address *addr = NULL;
unsigned prefixlen;
int r;
assert(address);
assert(netmask);
assert(lifetime);
prefixlen = in_addr_netmask_to_prefixlen(netmask);
r = address_new_dynamic(&addr);
if (r < 0)
return r;
addr->family = AF_INET;
addr->in_addr.in.s_addr = address->s_addr;
addr->cinfo.ifa_prefered = lifetime;
addr->cinfo.ifa_valid = lifetime;
addr->prefixlen = prefixlen;
addr->broadcast.s_addr = address->s_addr | ~netmask->s_addr;
/* use update rather than configure so that we will update the
* lifetime of an existing address if it has already been configured */
r = address_update(addr, link, &dhcp4_address_handler);
if (r < 0)
return r;
return 0;
}
static int dhcp_lease_renew(sd_dhcp_client *client, Link *link) {
sd_dhcp_lease *lease;
struct in_addr address;
struct in_addr netmask;
uint32_t lifetime = CACHE_INFO_INFINITY_LIFE_TIME;
int r;
assert(link);
assert(client);
assert(link->network);
r = sd_dhcp_client_get_lease(client, &lease);
if (r < 0) {
log_link_warning(link, "DHCP error: no lease %s",
strerror(-r));
return r;
}
sd_dhcp_lease_unref(link->dhcp_lease);
link->dhcp4_configured = false;
link->dhcp_lease = sd_dhcp_lease_ref(lease);
r = sd_dhcp_lease_get_address(lease, &address);
if (r < 0) {
log_link_warning(link, "DHCP error: no address: %s",
strerror(-r));
return r;
}
r = sd_dhcp_lease_get_netmask(lease, &netmask);
if (r < 0) {
log_link_warning(link, "DHCP error: no netmask: %s",
strerror(-r));
return r;
}
if (!link->network->dhcp_critical) {
r = sd_dhcp_lease_get_lifetime(link->dhcp_lease,
&lifetime);
if (r < 0) {
log_link_warning(link,
"DHCP error: no lifetime: %s",
strerror(-r));
return r;
}
}
r = dhcp4_update_address(link, &address, &netmask, lifetime);
if (r < 0) {
log_link_warning(link, "could not update IP address: %s",
strerror(-r));
link_enter_failed(link);
return r;
}
return 0;
}
static int dhcp_lease_acquired(sd_dhcp_client *client, Link *link) {
sd_dhcp_lease *lease;
struct in_addr address;
struct in_addr netmask;
struct in_addr gateway;
unsigned prefixlen;
uint32_t lifetime = CACHE_INFO_INFINITY_LIFE_TIME;
int r;
assert(client);
assert(link);
r = sd_dhcp_client_get_lease(client, &lease);
if (r < 0)
return log_link_error_errno(link, r, "DHCP error: no lease: %m");
r = sd_dhcp_lease_get_address(lease, &address);
if (r < 0)
return log_link_error_errno(link, r, "DHCP error: no address: %m");
r = sd_dhcp_lease_get_netmask(lease, &netmask);
if (r < 0)
return log_link_error_errno(link, r, "DHCP error: no netmask: %m");
prefixlen = in_addr_netmask_to_prefixlen(&netmask);
r = sd_dhcp_lease_get_router(lease, &gateway);
if (r < 0 && r != -ENOENT)
return log_link_error_errno(link, r, "DHCP error: could not get gateway: %m");
if (r >= 0)
log_struct(LOG_INFO,
LOG_LINK_INTERFACE(link),
LOG_LINK_MESSAGE(link, "DHCPv4 address %u.%u.%u.%u/%u via %u.%u.%u.%u",
ADDRESS_FMT_VAL(address),
prefixlen,
ADDRESS_FMT_VAL(gateway)),
"ADDRESS=%u.%u.%u.%u", ADDRESS_FMT_VAL(address),
"PREFIXLEN=%u", prefixlen,
"GATEWAY=%u.%u.%u.%u", ADDRESS_FMT_VAL(gateway),
NULL);
else
log_struct(LOG_INFO,
LOG_LINK_INTERFACE(link),
LOG_LINK_MESSAGE(link, "DHCPv4 address %u.%u.%u.%u/%u",
ADDRESS_FMT_VAL(address),
prefixlen),
"ADDRESS=%u.%u.%u.%u", ADDRESS_FMT_VAL(address),
"PREFIXLEN=%u", prefixlen,
NULL);
link->dhcp_lease = sd_dhcp_lease_ref(lease);
if (link->network->dhcp_mtu) {
uint16_t mtu;
r = sd_dhcp_lease_get_mtu(lease, &mtu);
if (r >= 0) {
r = link_set_mtu(link, mtu);
if (r < 0)
log_link_error_errno(link, r, "Failed to set MTU to %" PRIu16 ": %m", mtu);
}
}
if (link->network->dhcp_hostname) {
const char *hostname = NULL;
if (!link->network->hostname)
r = sd_dhcp_lease_get_hostname(lease, &hostname);
else
hostname = link->network->hostname;
if (r >= 0 || hostname) {
r = link_set_hostname(link, hostname);
if (r < 0)
log_link_error_errno(link, r, "Failed to set transient hostname to '%s': %m", hostname);
}
}
if (!link->network->dhcp_critical) {
r = sd_dhcp_lease_get_lifetime(link->dhcp_lease, &lifetime);
if (r < 0) {
log_link_warning_errno(link, r, "DHCP error: no lifetime: %m");
return r;
}
}
r = dhcp4_update_address(link, &address, &netmask, lifetime);
if (r < 0) {
log_link_warning_errno(link, r, "Could not update IP address: %m");
link_enter_failed(link);
return r;
}
return 0;
}
static void dhcp4_handler(sd_dhcp_client *client, int event, void *userdata) {
Link *link = userdata;
int r = 0;
assert(link);
assert(link->network);
assert(link->manager);
if (IN_SET(link->state, LINK_STATE_FAILED, LINK_STATE_LINGER))
return;
switch (event) {
case DHCP_EVENT_EXPIRED:
case DHCP_EVENT_STOP:
case DHCP_EVENT_IP_CHANGE:
if (link->network->dhcp_critical) {
log_link_error(link,
"DHCPv4 connection considered system critical, ignoring request to reconfigure it.");
return;
}
if (link->dhcp_lease) {
r = dhcp_lease_lost(link);
if (r < 0) {
link_enter_failed(link);
return;
}
}
if (event == DHCP_EVENT_IP_CHANGE) {
r = dhcp_lease_acquired(client, link);
if (r < 0) {
link_enter_failed(link);
return;
}
}
break;
case DHCP_EVENT_RENEW:
r = dhcp_lease_renew(client, link);
if (r < 0) {
link_enter_failed(link);
return;
}
break;
case DHCP_EVENT_IP_ACQUIRE:
r = dhcp_lease_acquired(client, link);
if (r < 0) {
link_enter_failed(link);
return;
}
break;
default:
if (event < 0)
log_link_warning(link,
"DHCP error: client failed: %s",
strerror(-event));
else
log_link_warning(link,
"DHCP unknown event: %d",
event);
break;
}
return;
}
int dhcp4_configure(Link *link) {
int r;
assert(link);
assert(link->network);
assert(link->network->dhcp & ADDRESS_FAMILY_IPV4);
r = sd_dhcp_client_new(&link->dhcp_client);
if (r < 0)
return r;
r = sd_dhcp_client_attach_event(link->dhcp_client, NULL, 0);
if (r < 0)
return r;
r = sd_dhcp_client_set_mac(link->dhcp_client,
(const uint8_t *) &link->mac,
sizeof (link->mac), ARPHRD_ETHER);
if (r < 0)
return r;
r = sd_dhcp_client_set_index(link->dhcp_client, link->ifindex);
if (r < 0)
return r;
r = sd_dhcp_client_set_callback(link->dhcp_client, dhcp4_handler, link);
if (r < 0)
return r;
r = sd_dhcp_client_set_request_broadcast(link->dhcp_client,
link->network->dhcp_broadcast);
if (r < 0)
return r;
if (link->mtu) {
r = sd_dhcp_client_set_mtu(link->dhcp_client, link->mtu);
if (r < 0)
return r;
}
if (link->network->dhcp_mtu) {
r = sd_dhcp_client_set_request_option(link->dhcp_client,
DHCP_OPTION_INTERFACE_MTU);
if (r < 0)
return r;
}
if (link->network->dhcp_routes) {
r = sd_dhcp_client_set_request_option(link->dhcp_client,
DHCP_OPTION_STATIC_ROUTE);
if (r < 0)
return r;
r = sd_dhcp_client_set_request_option(link->dhcp_client,
DHCP_OPTION_CLASSLESS_STATIC_ROUTE);
if (r < 0)
return r;
}
/* Always acquire the timezone */
r = sd_dhcp_client_set_request_option(link->dhcp_client, DHCP_OPTION_NEW_TZDB_TIMEZONE);
if (r < 0)
return r;
if (link->network->dhcp_sendhost) {
_cleanup_free_ char *hostname = NULL;
const char *hn = NULL;
if (!link->network->hostname) {
hostname = gethostname_malloc();
if (!hostname)
return -ENOMEM;
hn = hostname;
} else
hn = link->network->hostname;
if (!is_localhost(hn)) {
r = sd_dhcp_client_set_hostname(link->dhcp_client, hn);
if (r < 0)
return r;
}
}
if (link->network->dhcp_vendor_class_identifier) {
r = sd_dhcp_client_set_vendor_class_identifier(link->dhcp_client,
link->network->dhcp_vendor_class_identifier);
if (r < 0)
return r;
}
switch (link->network->dhcp_client_identifier) {
case DHCP_CLIENT_ID_DUID:
/* Library defaults to this. */
break;
case DHCP_CLIENT_ID_MAC:
r = sd_dhcp_client_set_client_id(link->dhcp_client,
ARPHRD_ETHER,
(const uint8_t *) &link->mac,
sizeof (link->mac));
if (r < 0)
return r;
break;
default:
assert_not_reached("Unknown client identifier type.");
}
return 0;
}