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Systemd/src/network/networkd-dhcp4.c
Lennart Poettering 2f8e763376 sd-network: rename "index" field of the various clients to "ifindex" 
A field "index" is not particularly precise and also might conflict with libc's
index() function definition. Also, pretty much everywhere else we call this
concept "ifindex", including in networkd, the primary user of these libraries.
Hence, let's fix this up and call this "ifindex" everywhere here too.
2016-05-26 15:34:42 +02:00

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/***
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 "alloc-util.h"
#include "dhcp-lease-internal.h"
#include "hostname-util.h"
#include "network-internal.h"
#include "networkd.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 > 0);
link->dhcp4_messages--;
r = sd_netlink_message_get_errno(m);
if (r < 0 && r != -EEXIST) {
log_link_error_errno(link, r, "Could not set DHCPv4 route: %m");
link_enter_failed(link);
}
if (link->dhcp4_messages == 0) {
link->dhcp4_configured = true;
link_check_ready(link);
}
return 1;
}
static int link_set_dhcp_routes(Link *link) {
struct in_addr gateway;
_cleanup_free_ sd_dhcp_route **static_routes = NULL;
int r, n, i;
assert(link);
assert(link->dhcp_lease);
assert(link->network);
if (!link->network->dhcp_use_routes)
return 0;
r = sd_dhcp_lease_get_router(link->dhcp_lease, &gateway);
if (r < 0 && r != -ENODATA)
return log_link_warning_errno(link, r, "DHCP error: could not get gateway: %m");
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)
return log_link_warning_errno(link, r, "DHCP error: could not get address: %m");
r = route_new(&route);
if (r < 0)
return log_link_error_errno(link, r, "Could not allocate route: %m");
route->protocol = RTPROT_DHCP;
r = route_new(&route_gw);
if (r < 0)
return log_link_error_errno(link, r, "Could not allocate route: %m");
/* 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.in = gateway;
route_gw->dst_prefixlen = 32;
route_gw->prefsrc.in = address;
route_gw->scope = RT_SCOPE_LINK;
route_gw->protocol = RTPROT_DHCP;
route_gw->priority = link->network->dhcp_route_metric;
r = route_configure(route_gw, link, dhcp4_route_handler);
if (r < 0)
return log_link_warning_errno(link, r, "Could not set host route: %m");
link->dhcp4_messages++;
route->family = AF_INET;
route->gw.in = gateway;
route->prefsrc.in = address;
route->priority = link->network->dhcp_route_metric;
r = route_configure(route, link, dhcp4_route_handler);
if (r < 0) {
log_link_warning_errno(link, r, "Could not set routes: %m");
link_enter_failed(link);
return r;
}
link->dhcp4_messages++;
}
n = sd_dhcp_lease_get_routes(link->dhcp_lease, &static_routes);
if (n == -ENODATA)
return 0;
if (n < 0)
return log_link_warning_errno(link, n, "DHCP error: could not get routes: %m");
for (i = 0; i < n; i++) {
_cleanup_route_free_ Route *route = NULL;
r = route_new(&route);
if (r < 0)
return log_link_error_errno(link, r, "Could not allocate route: %m");
route->family = AF_INET;
route->protocol = RTPROT_DHCP;
assert_se(sd_dhcp_route_get_gateway(static_routes[i], &route->gw.in) >= 0);
assert_se(sd_dhcp_route_get_destination(static_routes[i], &route->dst.in) >= 0);
assert_se(sd_dhcp_route_get_destination_prefix_length(static_routes[i], &route->dst_prefixlen) >= 0);
route->priority = link->network->dhcp_route_metric;
r = route_configure(route, link, dhcp4_route_handler);
if (r < 0)
return log_link_warning_errno(link, r, "Could not set host route: %m");
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_use_routes) {
_cleanup_free_ sd_dhcp_route **routes = NULL;
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(&route);
if (r >= 0) {
route->family = AF_INET;
assert_se(sd_dhcp_route_get_gateway(routes[i], &route->gw.in) >= 0);
assert_se(sd_dhcp_route_get_destination(routes[i], &route->dst.in) >= 0);
assert_se(sd_dhcp_route_get_destination_prefix_length(routes[i], &route->dst_prefixlen) >= 0);
route_remove(route, link,
link_route_remove_handler);
}
}
}
}
r = address_new(&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(&route_gw);
if (r >= 0) {
route_gw->family = AF_INET;
route_gw->dst.in = gateway;
route_gw->dst_prefixlen = 32;
route_gw->scope = RT_SCOPE_LINK;
route_remove(route_gw, link,
link_route_remove_handler);
}
r = route_new(&route);
if (r >= 0) {
route->family = AF_INET;
route->gw.in = gateway;
route_remove(route, link,
link_route_remove_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_remove(address, link, link_address_remove_handler);
}
}
if (link->network->dhcp_use_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_use_hostname) {
const char *hostname = NULL;
if (link->network->dhcp_hostname)
hostname = link->network->dhcp_hostname;
else
(void) sd_dhcp_lease_get_hostname(link->dhcp_lease, &hostname);
if (hostname) {
/* If a hostname was set due to the lease, then unset it now. */
r = link_set_hostname(link, NULL);
if (r < 0)
log_link_warning_errno(link, r, "Failed to reset transient hostname: %m");
}
}
link->dhcp_lease = sd_dhcp_lease_unref(link->dhcp_lease);
link_dirty(link);
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_errno(link, r, "Could not set DHCPv4 address: %m");
link_enter_failed(link);
} else if (r >= 0)
manager_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(&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;
/* allow reusing an existing address and simply update its lifetime
* in case it already exists */
r = address_configure(addr, link, dhcp4_address_handler, true);
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)
return log_link_warning_errno(link, r, "DHCP error: no lease: %m");
sd_dhcp_lease_unref(link->dhcp_lease);
link->dhcp4_configured = false;
link->dhcp_lease = sd_dhcp_lease_ref(lease);
link_dirty(link);
r = sd_dhcp_lease_get_address(lease, &address);
if (r < 0)
return log_link_warning_errno(link, r, "DHCP error: no address: %m");
r = sd_dhcp_lease_get_netmask(lease, &netmask);
if (r < 0)
return log_link_warning_errno(link, r, "DHCP error: no netmask: %m");
if (!link->network->dhcp_critical) {
r = sd_dhcp_lease_get_lifetime(link->dhcp_lease, &lifetime);
if (r < 0)
return log_link_warning_errno(link, r, "DHCP error: no lifetime: %m");
}
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 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 != -ENODATA)
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);
link_dirty(link);
if (link->network->dhcp_use_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_use_hostname) {
const char *hostname = NULL;
if (link->network->dhcp_hostname)
hostname = link->network->dhcp_hostname;
else
(void) sd_dhcp_lease_get_hostname(lease, &hostname);
if (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_use_timezone) {
const char *tz = NULL;
(void) sd_dhcp_lease_get_timezone(link->dhcp_lease, &tz);
if (tz) {
r = link_set_timezone(link, tz);
if (r < 0)
log_link_error_errno(link, r, "Failed to set timezone to '%s': %m", tz);
}
}
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 SD_DHCP_CLIENT_EVENT_EXPIRED:
case SD_DHCP_CLIENT_EVENT_STOP:
case SD_DHCP_CLIENT_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 == SD_DHCP_CLIENT_EVENT_IP_CHANGE) {
r = dhcp_lease_acquired(client, link);
if (r < 0) {
link_enter_failed(link);
return;
}
}
break;
case SD_DHCP_CLIENT_EVENT_RENEW:
r = dhcp_lease_renew(client, link);
if (r < 0) {
link_enter_failed(link);
return;
}
break;
case SD_DHCP_CLIENT_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_errno(link, event, "DHCP error: Client failed: %m");
else
log_link_warning(link, "DHCP unknown event: %i", event);
break;
}
return;
}
int dhcp4_configure(Link *link) {
int r;
assert(link);
assert(link->network);
assert(link->network->dhcp & ADDRESS_FAMILY_IPV4);
if (!link->dhcp_client) {
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_ifindex(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_use_mtu) {
r = sd_dhcp_client_set_request_option(link->dhcp_client,
SD_DHCP_OPTION_INTERFACE_MTU);
if (r < 0)
return r;
}
if (link->network->dhcp_use_routes) {
r = sd_dhcp_client_set_request_option(link->dhcp_client,
SD_DHCP_OPTION_STATIC_ROUTE);
if (r < 0)
return r;
r = sd_dhcp_client_set_request_option(link->dhcp_client,
SD_DHCP_OPTION_CLASSLESS_STATIC_ROUTE);
if (r < 0)
return r;
}
/* Always acquire the timezone and NTP */
r = sd_dhcp_client_set_request_option(link->dhcp_client, SD_DHCP_OPTION_NTP_SERVER);
if (r < 0)
return r;
r = sd_dhcp_client_set_request_option(link->dhcp_client, SD_DHCP_OPTION_NEW_TZDB_TIMEZONE);
if (r < 0)
return r;
if (link->network->dhcp_send_hostname) {
_cleanup_free_ char *hostname = NULL;
const char *hn = NULL;
if (!link->network->dhcp_hostname) {
hostname = gethostname_malloc();
if (!hostname)
return -ENOMEM;
hn = hostname;
} else
hn = link->network->dhcp_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: {
/* If configured, apply user specified DUID and/or IAID */
const DUID *duid = link_duid(link);
r = sd_dhcp_client_set_iaid_duid(link->dhcp_client,
link->network->iaid,
duid->type,
duid->raw_data_len > 0 ? duid->raw_data : NULL,
duid->raw_data_len);
if (r < 0)
return r;
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;
}
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