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-rw-r--r--src/network/networkd-dhcp4.c652
1 files changed, 652 insertions, 0 deletions
diff --git a/src/network/networkd-dhcp4.c b/src/network/networkd-dhcp4.c
new file mode 100644
index 0000000000..499e813f20
--- /dev/null
+++ b/src/network/networkd-dhcp4.c
@@ -0,0 +1,652 @@
+/*-*- 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 "networkd-link.h"
+#include "network-internal.h"
+#include "dhcp-lease-internal.h"
+
+static int dhcp4_route_handler(sd_rtnl *rtnl, sd_rtnl_message *m,
+ void *userdata) {
+ _cleanup_link_unref_ Link *link = userdata;
+ int r;
+
+ assert(link);
+ assert(link->dhcp4_messages);
+
+ link->dhcp4_messages --;
+
+ r = sd_rtnl_message_get_errno(m);
+ if (r < 0 && r != -EEXIST) {
+ log_error_link(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_warning_link(link,
+ "DHCP error: could not get gateway: %s",
+ strerror(-r));
+ return r;
+ }
+ if (r >= 0) {
+ _cleanup_route_free_ Route *route = NULL;
+ _cleanup_route_free_ Route *route_gw = NULL;
+
+ r = route_new_dynamic(&route, RTPROT_DHCP);
+ if (r < 0) {
+ log_error_link(link,
+ "Could not allocate route: %s",
+ strerror(-r));
+ return r;
+ }
+
+ r = route_new_dynamic(&route_gw, RTPROT_DHCP);
+ if (r < 0) {
+ log_error_link(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->scope = RT_SCOPE_LINK;
+ route_gw->metrics = DHCP_ROUTE_METRIC;
+
+ r = route_configure(route_gw, link, &dhcp4_route_handler);
+ if (r < 0) {
+ log_warning_link(link,
+ "could not set host route: %s",
+ strerror(-r));
+ return r;
+ }
+
+ link->dhcp4_messages ++;
+
+ route->family = AF_INET;
+ route->in_addr.in = gateway;
+ route->metrics = DHCP_ROUTE_METRIC;
+
+ r = route_configure(route, link, &dhcp4_route_handler);
+ if (r < 0) {
+ log_warning_link(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_warning_link(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_error_link(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 = DHCP_ROUTE_METRIC;
+
+ r = route_configure(route, link, &dhcp4_route_handler);
+ if (r < 0) {
+ log_warning_link(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;
+ int r;
+
+ assert(link);
+ assert(link->dhcp_lease);
+
+ log_warning_link(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);
+ }
+ }
+
+ sd_dhcp_lease_get_address(link->dhcp_lease, &addr);
+ sd_dhcp_lease_get_netmask(link->dhcp_lease, &netmask);
+ 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_warning_link(link,
+ "DHCP error: could not reset MTU");
+ link_enter_failed(link);
+ return r;
+ }
+ }
+ }
+
+ if (link->network->dhcp_hostname) {
+ const char *hostname = NULL;
+
+ r = sd_dhcp_lease_get_hostname(link->dhcp_lease, &hostname);
+ if (r >= 0 && hostname) {
+ r = link_set_hostname(link, "");
+ if (r < 0)
+ log_error_link(link,
+ "Failed to reset transient hostname");
+ }
+ }
+
+ link->dhcp_lease = sd_dhcp_lease_unref(link->dhcp_lease);
+ link->dhcp4_configured = false;
+
+ return 0;
+}
+
+static int dhcp4_address_handler(sd_rtnl *rtnl, sd_rtnl_message *m,
+ void *userdata) {
+ _cleanup_link_unref_ Link *link = userdata;
+ int r;
+
+ assert(link);
+
+ r = sd_rtnl_message_get_errno(m);
+ if (r < 0 && r != -EEXIST) {
+ log_error_link(link, "could not set DHCPv4 address: %s",
+ strerror(-r));
+ link_enter_failed(link);
+ } else if (r >= 0) {
+ /* calling handler directly so take a ref */
+ link_ref(link);
+ link_get_address_handler(rtnl, m, link);
+ }
+
+ 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_warning_link(link, "DHCP error: no lease %s",
+ strerror(-r));
+ return r;
+ }
+
+ sd_dhcp_lease_unref(link->dhcp_lease);
+ link->dhcp4_configured = false;
+ link->dhcp_lease = lease;
+
+ r = sd_dhcp_lease_get_address(lease, &address);
+ if (r < 0) {
+ log_warning_link(link, "DHCP error: no address: %s",
+ strerror(-r));
+ return r;
+ }
+
+ r = sd_dhcp_lease_get_netmask(lease, &netmask);
+ if (r < 0) {
+ log_warning_link(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_warning_link(link,
+ "DHCP error: no lifetime: %s",
+ strerror(-r));
+ return r;
+ }
+ }
+
+ r = dhcp4_update_address(link, &address, &netmask, lifetime);
+ if (r < 0) {
+ log_warning_link(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) {
+ log_warning_link(link, "DHCP error: no lease: %s",
+ strerror(-r));
+ return r;
+ }
+
+ r = sd_dhcp_lease_get_address(lease, &address);
+ if (r < 0) {
+ log_warning_link(link, "DHCP error: no address: %s",
+ strerror(-r));
+ return r;
+ }
+
+ r = sd_dhcp_lease_get_netmask(lease, &netmask);
+ if (r < 0) {
+ log_warning_link(link, "DHCP error: no netmask: %s",
+ strerror(-r));
+ return r;
+ }
+
+ prefixlen = in_addr_netmask_to_prefixlen(&netmask);
+
+ r = sd_dhcp_lease_get_router(lease, &gateway);
+ if (r < 0 && r != -ENOENT) {
+ log_warning_link(link, "DHCP error: could not get gateway: %s",
+ strerror(-r));
+ return r;
+ }
+
+ if (r >= 0)
+ log_struct_link(LOG_INFO, link,
+ "MESSAGE=%-*s: DHCPv4 address %u.%u.%u.%u/%u via %u.%u.%u.%u",
+ IFNAMSIZ,
+ link->ifname,
+ 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_link(LOG_INFO, link,
+ "MESSAGE=%-*s: DHCPv4 address %u.%u.%u.%u/%u",
+ IFNAMSIZ,
+ link->ifname,
+ ADDRESS_FMT_VAL(address),
+ prefixlen,
+ "ADDRESS=%u.%u.%u.%u",
+ ADDRESS_FMT_VAL(address),
+ "PREFIXLEN=%u",
+ prefixlen,
+ NULL);
+
+ link->dhcp_lease = 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_error_link(link, "Failed to set MTU "
+ "to %" PRIu16, mtu);
+ }
+ }
+
+ if (link->network->dhcp_hostname) {
+ const char *hostname;
+
+ r = sd_dhcp_lease_get_hostname(lease, &hostname);
+ if (r >= 0) {
+ r = link_set_hostname(link, hostname);
+ if (r < 0)
+ log_error_link(link,
+ "Failed to set transient hostname to '%s'",
+ hostname);
+ }
+ }
+
+ if (!link->network->dhcp_critical) {
+ r = sd_dhcp_lease_get_lifetime(link->dhcp_lease,
+ &lifetime);
+ if (r < 0) {
+ log_warning_link(link,
+ "DHCP error: no lifetime: %s",
+ strerror(-r));
+ return r;
+ }
+ }
+
+ r = dhcp4_update_address(link, &address, &netmask, lifetime);
+ if (r < 0) {
+ log_warning_link(link, "could not update IP address: %s",
+ strerror(-r));
+ 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_error_link(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_warning_link(link,
+ "DHCP error: client failed: %s",
+ strerror(-event));
+ else
+ log_warning_link(link,
+ "DHCP unknown event: %d",
+ event);
+ break;
+ }
+
+ return;
+}
+
+int dhcp4_configure(Link *link) {
+ int r;
+
+ assert(link);
+ assert(link->network);
+ assert(link->network->ipv4ll);
+
+ 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, &link->mac);
+ 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;
+ }
+
+ if (link->network->dhcp_sendhost) {
+ _cleanup_free_ char *hostname = NULL;
+
+ hostname = gethostname_malloc();
+ if (!hostname)
+ return -ENOMEM;
+
+ if (!is_localhost(hostname)) {
+ r = sd_dhcp_client_set_hostname(link->dhcp_client,
+ hostname);
+ 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;
+ }
+
+ return 0;
+}
generated by cgit v1.2.3-54-g00ecf (git 2.45.2) at 2024-12-14 05:23:31 +0000