/*-*- 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 "alloc-util.h" #include "dhcp-lease-internal.h" #include "hostname-util.h" #include "network-internal.h" #include "networkd-link.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; 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 != -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; route->gw.in = static_routes[i].gw_addr; route->dst.in = static_routes[i].dst_addr; route->dst_prefixlen = static_routes[i].dst_prefixlen; 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_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(&route); if (r >= 0) { route->family = AF_INET; route->gw.in = routes[i].gw_addr; route->dst.in = routes[i].dst_addr; route->dst_prefixlen = routes[i].dst_prefixlen; 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_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) hostname = link->network->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->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); 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); 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) hostname = link->network->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_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_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 and NTP*/ r = sd_dhcp_client_set_request_option(link->dhcp_client, DHCP_OPTION_NTP_SERVER); if (r < 0) return r; 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; }