/* SPDX-License-Identifier: LGPL-2.1+ */ #include #include #include "alloc-util.h" #include "hostname-util.h" #include "parse-util.h" #include "network-internal.h" #include "networkd-dhcp4.h" #include "networkd-link.h" #include "networkd-manager.h" #include "networkd-network.h" #include "string-table.h" #include "string-util.h" #include "sysctl-util.h" static int dhcp_remove_routes(Link *link, sd_dhcp_lease *lease, const struct in_addr *address, bool remove_all); static int dhcp_remove_router(Link *link, sd_dhcp_lease *lease, const struct in_addr *address, bool remove_all); static int dhcp_remove_dns_routes(Link *link, sd_dhcp_lease *lease, const struct in_addr *address, bool remove_all); static int dhcp_remove_address(Link *link, sd_dhcp_lease *lease, const struct in_addr *address); void dhcp4_release_old_lease(Link *link) { struct in_addr address = {}, address_old = {}; assert(link); if (!link->dhcp_lease_old) return; assert(link->dhcp_lease); (void) sd_dhcp_lease_get_address(link->dhcp_lease_old, &address_old); (void) sd_dhcp_lease_get_address(link->dhcp_lease, &address); (void) dhcp_remove_routes(link, link->dhcp_lease_old, &address_old, false); (void) dhcp_remove_router(link, link->dhcp_lease_old, &address_old, false); (void) dhcp_remove_dns_routes(link, link->dhcp_lease_old, &address_old, false); if (!in4_addr_equal(&address_old, &address)) (void) dhcp_remove_address(link, link->dhcp_lease_old, &address_old); link->dhcp_lease_old = sd_dhcp_lease_unref(link->dhcp_lease_old); link_dirty(link); } static int dhcp4_route_handler(sd_netlink *rtnl, sd_netlink_message *m, Link *link) { int r; assert(link); assert(link->dhcp4_messages > 0); link->dhcp4_messages--; if (IN_SET(link->state, LINK_STATE_FAILED, LINK_STATE_LINGER)) return 1; 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); return 1; } if (link->dhcp4_messages == 0) { link->dhcp4_configured = true; /* New address and routes are configured now. Let's release old lease. */ dhcp4_release_old_lease(link); link_check_ready(link); } return 1; } static int route_scope_from_address(const Route *route, const struct in_addr *self_addr) { assert(route); assert(self_addr); if (in4_addr_is_localhost(&route->dst.in) || (!in4_addr_is_null(self_addr) && in4_addr_equal(&route->dst.in, self_addr))) return RT_SCOPE_HOST; else if (in4_addr_is_null(&route->gw.in)) return RT_SCOPE_LINK; else return RT_SCOPE_UNIVERSE; } static int dhcp_route_configure(Route **route, Link *link) { int r; assert(route); assert(*route); assert(link); if (set_contains(link->dhcp_routes, *route)) return 0; r = route_configure(*route, link, dhcp4_route_handler); if (r <= 0) return r; link->dhcp4_messages++; r = set_put(link->dhcp_routes, *route); if (r < 0) return r; TAKE_PTR(*route); return 0; } static int link_set_dns_routes(Link *link, const struct in_addr *address) { const struct in_addr *dns; uint32_t table; int i, n, r; assert(link); assert(link->dhcp_lease); assert(link->network); if (!link->network->dhcp_use_dns || !link->network->dhcp_routes_to_dns) return 0; n = sd_dhcp_lease_get_dns(link->dhcp_lease, &dns); if (IN_SET(n, 0, -ENODATA)) return 0; if (n < 0) return log_link_warning_errno(link, n, "DHCP error: could not get DNS servers: %m"); table = link_get_dhcp_route_table(link); for (i = 0; i < n; i ++) { _cleanup_(route_freep) Route *route = NULL; r = route_new(&route); if (r < 0) return log_link_error_errno(link, r, "Could not allocate route: %m"); /* Set routes to DNS servers. */ route->family = AF_INET; route->dst.in = dns[i]; route->dst_prefixlen = 32; route->prefsrc.in = *address; route->scope = RT_SCOPE_LINK; route->protocol = RTPROT_DHCP; route->priority = link->network->dhcp_route_metric; route->table = table; r = dhcp_route_configure(&route, link); if (r < 0) return log_link_error_errno(link, r, "Could not set route to DNS server: %m"); } return 0; } static int link_set_dhcp_routes(Link *link) { _cleanup_free_ sd_dhcp_route **static_routes = NULL; bool classless_route = false, static_route = false; const struct in_addr *router; struct in_addr address; int r, n, i; uint32_t table; assert(link); if (!link->dhcp_lease) /* link went down while we configured the IP addresses? */ return 0; if (!link->network) /* link went down while we configured the IP addresses? */ return 0; if (!link->network->dhcp_use_routes) return 0; if (!link_has_carrier(link) && !link->network->configure_without_carrier) /* During configuring addresses, the link lost its carrier. As networkd is dropping * the addresses now, let's not configure the routes either. */ return 0; r = set_ensure_allocated(&link->dhcp_routes, &route_full_hash_ops); if (r < 0) return log_oom(); /* Clear old entries in case the set was already allocated */ set_clear(link->dhcp_routes); table = link_get_dhcp_route_table(link); 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"); n = sd_dhcp_lease_get_routes(link->dhcp_lease, &static_routes); if (n == -ENODATA) log_link_debug_errno(link, n, "DHCP: No routes received from DHCP server: %m"); else if (n < 0) log_link_debug_errno(link, n, "DHCP error: could not get routes: %m"); for (i = 0; i < n; i++) { switch (sd_dhcp_route_get_option(static_routes[i])) { case SD_DHCP_OPTION_CLASSLESS_STATIC_ROUTE: classless_route = true; break; case SD_DHCP_OPTION_STATIC_ROUTE: static_route = true; break; } } for (i = 0; i < n; i++) { _cleanup_(route_freep) Route *route = NULL; /* if the DHCP server returns both a Classless Static Routes option and a Static Routes option, the DHCP client MUST ignore the Static Routes option. */ if (classless_route && sd_dhcp_route_get_option(static_routes[i]) != SD_DHCP_OPTION_CLASSLESS_STATIC_ROUTE) continue; 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; route->table = table; route->scope = route_scope_from_address(route, &address); if (IN_SET(route->scope, RT_SCOPE_LINK, RT_SCOPE_UNIVERSE)) route->prefsrc.in = address; if (set_contains(link->dhcp_routes, route)) continue; r = dhcp_route_configure(&route, link); if (r < 0) return log_link_error_errno(link, r, "Could not set route: %m"); } r = sd_dhcp_lease_get_router(link->dhcp_lease, &router); if (IN_SET(r, 0, -ENODATA)) log_link_info(link, "DHCP: No gateway received from DHCP server."); else if (r < 0) log_link_warning_errno(link, r, "DHCP error: could not get gateway: %m"); else if (in4_addr_is_null(&router[0])) log_link_info(link, "DHCP: Received gateway is null."); /* According to RFC 3442: If the DHCP server returns both a Classless Static Routes option and a Router option, the DHCP client MUST ignore the Router option. */ if (classless_route && static_route) log_link_warning(link, "Classless static routes received from DHCP server: ignoring static-route option and router option"); if (r > 0 && !classless_route && !in4_addr_is_null(&router[0])) { _cleanup_(route_freep) Route *route = NULL, *route_gw = NULL; 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 = router[0]; 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; route_gw->table = table; r = dhcp_route_configure(&route_gw, link); if (r < 0) return log_link_error_errno(link, r, "Could not set host route: %m"); r = route_new(&route); if (r < 0) return log_link_error_errno(link, r, "Could not allocate route: %m"); route->family = AF_INET; route->gw.in = router[0]; route->prefsrc.in = address; route->protocol = RTPROT_DHCP; route->priority = link->network->dhcp_route_metric; route->table = table; r = dhcp_route_configure(&route, link); if (r < 0) return log_link_error_errno(link, r, "Could not set router: %m"); } return link_set_dns_routes(link, &address); } static int dhcp_remove_routes(Link *link, sd_dhcp_lease *lease, const struct in_addr *address, bool remove_all) { _cleanup_free_ sd_dhcp_route **routes = NULL; uint32_t table; int n, i, r; assert(link); assert(address); if (!link->network->dhcp_use_routes) return 0; n = sd_dhcp_lease_get_routes(lease, &routes); if (IN_SET(n, 0, -ENODATA)) return 0; else if (n < 0) return log_link_error_errno(link, n, "DHCP error: Failed to get routes: %m"); table = link_get_dhcp_route_table(link); for (i = 0; i < n; i++) { _cleanup_(route_freep) Route *route = NULL; r = route_new(&route); if (r < 0) return log_oom(); 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->priority = link->network->dhcp_route_metric; route->table = table; route->scope = route_scope_from_address(route, address); if (IN_SET(route->scope, RT_SCOPE_LINK, RT_SCOPE_UNIVERSE)) route->prefsrc.in = *address; if (!remove_all && set_contains(link->dhcp_routes, route)) continue; (void) route_remove(route, link, NULL); } return n; } static int dhcp_remove_router(Link *link, sd_dhcp_lease *lease, const struct in_addr *address, bool remove_all) { _cleanup_(route_freep) Route *route_gw = NULL, *route = NULL; const struct in_addr *router; uint32_t table; int r; assert(link); assert(address); if (!link->network->dhcp_use_routes) return 0; r = sd_dhcp_lease_get_router(lease, &router); if (IN_SET(r, 0, -ENODATA)) { log_link_debug(link, "DHCP: No gateway received from DHCP server."); return 0; } else if (r < 0) return log_link_error_errno(link, r, "DHCP error: could not get gateway: %m"); else if (in4_addr_is_null(&router[0])) { log_link_info(link, "DHCP: Received gateway is null, ignoring."); return 0; } table = link_get_dhcp_route_table(link); r = route_new(&route_gw); if (r < 0) return log_oom(); route_gw->family = AF_INET; route_gw->dst.in = router[0]; 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; route_gw->table = table; if (remove_all || !set_contains(link->dhcp_routes, route_gw)) (void) route_remove(route_gw, link, NULL); r = route_new(&route); if (r < 0) return log_oom(); route->family = AF_INET; route->gw.in = router[0]; route->prefsrc.in = *address; route->protocol = RTPROT_DHCP; route->priority = link->network->dhcp_route_metric; route->table = table; if (remove_all || !set_contains(link->dhcp_routes, route)) (void) route_remove(route, link, NULL); return 0; } static int dhcp_remove_dns_routes(Link *link, sd_dhcp_lease *lease, const struct in_addr *address, bool remove_all) { const struct in_addr *dns; uint32_t table; int i, n, r; assert(link); assert(lease); assert(link->network); if (!link->network->dhcp_use_dns || !link->network->dhcp_routes_to_dns) return 0; n = sd_dhcp_lease_get_dns(lease, &dns); if (IN_SET(n, 0, -ENODATA)) return 0; if (n < 0) return log_link_warning_errno(link, n, "DHCP error: could not get DNS servers: %m"); table = link_get_dhcp_route_table(link); for (i = 0; i < n; i ++) { _cleanup_(route_freep) 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->dst.in = dns[i]; route->dst_prefixlen = 32; route->prefsrc.in = *address; route->scope = RT_SCOPE_LINK; route->protocol = RTPROT_DHCP; route->priority = link->network->dhcp_route_metric; route->table = table; if (!remove_all && set_contains(link->dhcp_routes, route)) continue; (void) route_remove(route, link, NULL); } return 0; } static int dhcp_remove_address(Link *link, sd_dhcp_lease *lease, const struct in_addr *address) { _cleanup_(address_freep) Address *a = NULL; struct in_addr netmask; int r; assert(link); assert(address); if (in4_addr_is_null(address)) return 0; r = address_new(&a); if (r < 0) return log_oom(); a->family = AF_INET; a->in_addr.in = *address; if (sd_dhcp_lease_get_netmask(lease, &netmask) >= 0) a->prefixlen = in4_addr_netmask_to_prefixlen(&netmask); (void) address_remove(a, link, NULL); return 0; } static int dhcp_reset_mtu(Link *link) { uint16_t mtu; int r; assert(link); if (!link->network->dhcp_use_mtu) return 0; r = sd_dhcp_lease_get_mtu(link->dhcp_lease, &mtu); if (r < 0) return r; if (link->original_mtu == mtu) return 0; r = link_set_mtu(link, link->original_mtu); if (r < 0) { log_link_error_errno(link, r, "DHCP error: could not reset MTU: %m"); link_enter_failed(link); return r; } return 0; } static int dhcp_reset_hostname(Link *link) { const char *hostname; int r; assert(link); if (!link->network->dhcp_use_hostname) return 0; hostname = link->network->dhcp_hostname; if (!hostname) (void) sd_dhcp_lease_get_hostname(link->dhcp_lease, &hostname); if (!hostname) return 0; /* If a hostname was set due to the lease, then unset it now. */ r = manager_set_hostname(link->manager, NULL); if (r < 0) return log_link_error_errno(link, r, "DHCP error: Failed to reset transient hostname: %m"); return 0; } static int dhcp_lease_lost(Link *link) { struct in_addr address = {}; assert(link); assert(link->dhcp_lease); log_link_warning(link, "DHCP lease lost"); link->dhcp4_configured = false; (void) sd_dhcp_lease_get_address(link->dhcp_lease, &address); (void) dhcp_remove_routes(link, link->dhcp_lease, &address, true); (void) dhcp_remove_router(link, link->dhcp_lease, &address, true); (void) dhcp_remove_dns_routes(link, link->dhcp_lease, &address, true); (void) dhcp_remove_address(link, link->dhcp_lease, &address); (void) dhcp_reset_mtu(link); (void) dhcp_reset_hostname(link); link->dhcp_lease = sd_dhcp_lease_unref(link->dhcp_lease); link_dirty(link); return 0; } static int dhcp4_address_handler(sd_netlink *rtnl, sd_netlink_message *m, Link *link) { int r; assert(link); if (IN_SET(link->state, LINK_STATE_FAILED, LINK_STATE_LINGER)) return 1; 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); return 1; } else if (r >= 0) (void) manager_rtnl_process_address(rtnl, m, link->manager); r = link_set_dhcp_routes(link); if (r < 0) { link_enter_failed(link); return 1; } /* Add back static routes since kernel removes while DHCPv4 address is removed from when lease expires */ r = link_request_set_routes(link); if (r < 0) { link_enter_failed(link); return 1; } if (link->dhcp4_messages == 0) { link->dhcp4_configured = true; /* The new address is configured, and no route is requested. * Let's drop the old lease. */ dhcp4_release_old_lease(link); link_check_ready(link); } return 1; } static int dhcp4_update_address(Link *link, struct in_addr *address, struct in_addr *netmask, uint32_t lifetime) { _cleanup_(address_freep) Address *addr = NULL; unsigned prefixlen; int r; assert(address); assert(netmask); assert(lifetime); prefixlen = in4_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 (!FLAGS_SET(link->network->keep_configuration, KEEP_CONFIGURATION_DHCP)) { 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) return log_link_warning_errno(link, r, "Could not update IP address: %m"); return 0; } static int dhcp_lease_acquired(sd_dhcp_client *client, Link *link) { const struct in_addr *router; sd_dhcp_lease *lease; struct in_addr address; struct in_addr netmask; unsigned prefixlen; uint32_t lifetime = CACHE_INFO_INFINITY_LIFE_TIME; int r; assert(client); assert(link); link->dhcp4_configured = false; 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 = in4_addr_netmask_to_prefixlen(&netmask); if (!FLAGS_SET(link->network->keep_configuration, KEEP_CONFIGURATION_DHCP)) { r = sd_dhcp_lease_get_lifetime(lease, &lifetime); if (r < 0) return log_link_warning_errno(link, r, "DHCP error: no lifetime: %m"); } r = sd_dhcp_lease_get_router(lease, &router); if (r < 0 && r != -ENODATA) return log_link_error_errno(link, r, "DHCP error: Could not get gateway: %m"); if (r > 0 && !in4_addr_is_null(&router[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(router[0])), "ADDRESS=%u.%u.%u.%u", ADDRESS_FMT_VAL(address), "PREFIXLEN=%u", prefixlen, "GATEWAY=%u.%u.%u.%u", ADDRESS_FMT_VAL(router[0])); 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); 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 *dhcpname = NULL; _cleanup_free_ char *hostname = NULL; if (link->network->dhcp_hostname) dhcpname = link->network->dhcp_hostname; else (void) sd_dhcp_lease_get_hostname(lease, &dhcpname); if (dhcpname) { r = shorten_overlong(dhcpname, &hostname); if (r < 0) log_link_warning_errno(link, r, "Unable to shorten overlong DHCP hostname '%s', ignoring: %m", dhcpname); if (r == 1) log_link_notice(link, "Overlong DHCP hostname received, shortened from '%s' to '%s'", dhcpname, hostname); } if (hostname) { r = manager_set_hostname(link->manager, 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 = manager_set_timezone(link->manager, tz); if (r < 0) log_link_error_errno(link, r, "Failed to set timezone to '%s': %m", tz); } } r = dhcp4_update_address(link, &address, &netmask, lifetime); if (r < 0) return log_link_warning_errno(link, r, "Could not update IP address: %m"); return 0; } static int dhcp_lease_ip_change(sd_dhcp_client *client, Link *link) { int r; link->dhcp_lease_old = TAKE_PTR(link->dhcp_lease); /* On ip address change, to keep the connectability, we would like to assign new address and * routes, and then release old lease. There are two possible success paths: * * 1. new address and routes are configured. * -> handled by dhcp_release_old_lease() in dhcp4_route_handler(). * 2. new address is configured and no route is requested. * -> handled by dhcp_release_old_lease() in dhcp4_address_handler(). * * On error in assigning new address and routes, then the link always enters to the failed * state. And link_enter_failed() leads to the DHCP client to be stopped. So, * dhcp_release_old_lease() will be also called by link_stop_clients(). */ r = dhcp_lease_acquired(client, link); if (r < 0) { /* If it fails, then the new address is not configured yet. * So, let's simply drop the old lease. */ sd_dhcp_lease_unref(link->dhcp_lease); link->dhcp_lease = TAKE_PTR(link->dhcp_lease_old); (void) dhcp_lease_lost(link); return r; } return 0; } static int dhcp_server_is_black_listed(Link *link, sd_dhcp_client *client) { sd_dhcp_lease *lease; struct in_addr addr; int r; assert(link); assert(link->network); assert(client); r = sd_dhcp_client_get_lease(client, &lease); if (r < 0) return log_link_error_errno(link, r, "Failed to get DHCP lease: %m"); r = sd_dhcp_lease_get_server_identifier(lease, &addr); if (r < 0) return log_link_debug_errno(link, r, "Failed to get DHCP server ip address: %m"); if (set_contains(link->network->dhcp_black_listed_ip, UINT32_TO_PTR(addr.s_addr))) { log_struct(LOG_DEBUG, LOG_LINK_INTERFACE(link), LOG_LINK_MESSAGE(link, "DHCPv4 ip '%u.%u.%u.%u' found in black listed ip addresses, ignoring offer", ADDRESS_FMT_VAL(addr))); return true; } return false; } static int dhcp4_handler(sd_dhcp_client *client, int event, void *userdata) { Link *link = userdata; int r; assert(link); assert(link->network); assert(link->manager); if (IN_SET(link->state, LINK_STATE_FAILED, LINK_STATE_LINGER)) return 0; switch (event) { case SD_DHCP_CLIENT_EVENT_STOP: if (link_ipv4ll_enabled(link, ADDRESS_FAMILY_FALLBACK_IPV4)) { assert(link->ipv4ll); log_link_debug(link, "DHCP client is stopped. Acquiring IPv4 link-local address"); r = sd_ipv4ll_start(link->ipv4ll); if (r < 0) return log_link_warning_errno(link, r, "Could not acquire IPv4 link-local address: %m"); } if (FLAGS_SET(link->network->keep_configuration, KEEP_CONFIGURATION_DHCP)) { log_link_notice(link, "DHCPv4 connection considered critical, ignoring request to reconfigure it."); return 0; } if (link->network->dhcp_send_release) (void) sd_dhcp_client_send_release(client); if (link->dhcp_lease) { r = dhcp_lease_lost(link); if (r < 0) { link_enter_failed(link); return r; } } break; case SD_DHCP_CLIENT_EVENT_EXPIRED: if (FLAGS_SET(link->network->keep_configuration, KEEP_CONFIGURATION_DHCP)) { log_link_notice(link, "DHCPv4 connection considered critical, ignoring request to reconfigure it."); return 0; } if (link->dhcp_lease) { r = dhcp_lease_lost(link); if (r < 0) { link_enter_failed(link); return r; } } break; case SD_DHCP_CLIENT_EVENT_IP_CHANGE: if (FLAGS_SET(link->network->keep_configuration, KEEP_CONFIGURATION_DHCP)) { log_link_notice(link, "DHCPv4 connection considered critical, ignoring request to reconfigure it."); return 0; } r = dhcp_lease_ip_change(client, link); if (r < 0) { link_enter_failed(link); return r; } break; case SD_DHCP_CLIENT_EVENT_RENEW: r = dhcp_lease_renew(client, link); if (r < 0) { link_enter_failed(link); return r; } break; case SD_DHCP_CLIENT_EVENT_IP_ACQUIRE: r = dhcp_lease_acquired(client, link); if (r < 0) { link_enter_failed(link); return r; } break; case SD_DHCP_CLIENT_EVENT_SELECTING: r = dhcp_server_is_black_listed(link, client); if (r < 0) return r; if (r != 0) return -ENOMSG; 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 0; } static int dhcp4_set_hostname(Link *link) { _cleanup_free_ char *hostname = NULL; const char *hn; int r; assert(link); if (!link->network->dhcp_send_hostname) hn = NULL; else if (link->network->dhcp_hostname) hn = link->network->dhcp_hostname; else { r = gethostname_strict(&hostname); if (r < 0 && r != -ENXIO) /* ENXIO: no hostname set or hostname is "localhost" */ return r; hn = hostname; } r = sd_dhcp_client_set_hostname(link->dhcp_client, hn); if (r == -EINVAL && hostname) /* Ignore error when the machine's hostname is not suitable to send in DHCP packet. */ log_link_warning_errno(link, r, "DHCP4 CLIENT: Failed to set hostname from kernel hostname, ignoring: %m"); else if (r < 0) return log_link_error_errno(link, r, "DHCP4 CLIENT: Failed to set hostname: %m"); return 0; } static bool promote_secondaries_enabled(const char *ifname) { _cleanup_free_ char *promote_secondaries_sysctl = NULL; char *promote_secondaries_path; int r; promote_secondaries_path = strjoina("net/ipv4/conf/", ifname, "/promote_secondaries"); r = sysctl_read(promote_secondaries_path, &promote_secondaries_sysctl); if (r < 0) { log_debug_errno(r, "Cannot read sysctl %s", promote_secondaries_path); return false; } truncate_nl(promote_secondaries_sysctl); r = parse_boolean(promote_secondaries_sysctl); if (r < 0) log_warning_errno(r, "Cannot parse sysctl %s with content %s as boolean", promote_secondaries_path, promote_secondaries_sysctl); return r > 0; } /* dhcp4_set_promote_secondaries will ensure this interface has * the "promote_secondaries" option in the kernel set. If this sysctl * is not set DHCP will work only as long as the IP address does not * changes between leases. The kernel will remove all secondary IP * addresses of an interface otherwise. The way systemd-network works * is that the new IP of a lease is added as a secondary IP and when * the primary one expires it relies on the kernel to promote the * secondary IP. See also https://github.com/systemd/systemd/issues/7163 */ int dhcp4_set_promote_secondaries(Link *link) { int r; assert(link); assert(link->network); assert(link->network->dhcp & ADDRESS_FAMILY_IPV4); /* check if the kernel has promote_secondaries enabled for our * interface. If it is not globally enabled or enabled for the * specific interface we must either enable it. */ if (!(promote_secondaries_enabled("all") || promote_secondaries_enabled(link->ifname))) { char *promote_secondaries_path = NULL; log_link_debug(link, "promote_secondaries is unset, setting it"); promote_secondaries_path = strjoina("net/ipv4/conf/", link->ifname, "/promote_secondaries"); r = sysctl_write(promote_secondaries_path, "1"); if (r < 0) log_link_warning_errno(link, r, "cannot set sysctl %s to 1", promote_secondaries_path); return r > 0; } return 0; } int dhcp4_set_client_identifier(Link *link) { int r; assert(link); assert(link->network); assert(link->dhcp_client); switch (link->network->dhcp_client_identifier) { case DHCP_CLIENT_ID_DUID: { /* If configured, apply user specified DUID and IAID */ const DUID *duid = link_get_duid(link); if (duid->type == DUID_TYPE_LLT && duid->raw_data_len == 0) r = sd_dhcp_client_set_iaid_duid_llt(link->dhcp_client, link->network->iaid_set, link->network->iaid, duid->llt_time); else r = sd_dhcp_client_set_iaid_duid(link->dhcp_client, link->network->iaid_set, link->network->iaid, duid->type, duid->raw_data_len > 0 ? duid->raw_data : NULL, duid->raw_data_len); if (r < 0) return log_link_error_errno(link, r, "DHCP4 CLIENT: Failed to set IAID+DUID: %m"); break; } case DHCP_CLIENT_ID_DUID_ONLY: { /* If configured, apply user specified DUID */ const DUID *duid = link_get_duid(link); if (duid->type == DUID_TYPE_LLT && duid->raw_data_len == 0) r = sd_dhcp_client_set_duid_llt(link->dhcp_client, duid->llt_time); else r = sd_dhcp_client_set_duid(link->dhcp_client, duid->type, duid->raw_data_len > 0 ? duid->raw_data : NULL, duid->raw_data_len); if (r < 0) return log_link_error_errno(link, r, "DHCP4 CLIENT: Failed to set DUID: %m"); 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 log_link_error_errno(link, r, "DHCP4 CLIENT: Failed to set client ID: %m"); break; default: assert_not_reached("Unknown client identifier type."); } return 0; } 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, link->network->dhcp_anonymize); if (r == -ENOMEM) return log_oom(); if (r < 0) return log_link_error_errno(link, r, "DHCP4 CLIENT: Failed to create DHCP4 client: %m"); } r = sd_dhcp_client_attach_event(link->dhcp_client, NULL, 0); if (r < 0) return log_link_error_errno(link, r, "DHCP4 CLIENT: Failed to attach event: %m"); r = sd_dhcp_client_set_mac(link->dhcp_client, (const uint8_t *) &link->mac, sizeof (link->mac), ARPHRD_ETHER); if (r < 0) return log_link_error_errno(link, r, "DHCP4 CLIENT: Failed to set MAC address: %m"); r = sd_dhcp_client_set_ifindex(link->dhcp_client, link->ifindex); if (r < 0) return log_link_error_errno(link, r, "DHCP4 CLIENT: Failed to set ifindex: %m"); r = sd_dhcp_client_set_callback(link->dhcp_client, dhcp4_handler, link); if (r < 0) return log_link_error_errno(link, r, "DHCP4 CLIENT: Failed to set callback: %m"); r = sd_dhcp_client_set_request_broadcast(link->dhcp_client, link->network->dhcp_broadcast); if (r < 0) return log_link_error_errno(link, r, "DHCP4 CLIENT: Failed to set request flag for broadcast: %m"); if (link->mtu) { r = sd_dhcp_client_set_mtu(link->dhcp_client, link->mtu); if (r < 0) return log_link_error_errno(link, r, "DHCP4 CLIENT: Failed to set MTU: %m"); } 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 log_link_error_errno(link, r, "DHCP4 CLIENT: Failed to set request flag for MTU: %m"); } /* NOTE: even if this variable is called "use", it also "sends" PRL * options, maybe there should be a different configuration variable * to send or not route options?. */ /* NOTE: when using Anonymize=yes, routes PRL options are sent * by default, so they don't need to be added here. */ if (link->network->dhcp_use_routes && !link->network->dhcp_anonymize) { r = sd_dhcp_client_set_request_option(link->dhcp_client, SD_DHCP_OPTION_STATIC_ROUTE); if (r < 0) return log_link_error_errno(link, r, "DHCP4 CLIENT: Failed to set request flag for static route: %m"); r = sd_dhcp_client_set_request_option(link->dhcp_client, SD_DHCP_OPTION_CLASSLESS_STATIC_ROUTE); if (r < 0) return log_link_error_errno(link, r, "DHCP4 CLIENT: Failed to set request flag for classless static route: %m"); } if (link->network->dhcp_use_domains != DHCP_USE_DOMAINS_NO && !link->network->dhcp_anonymize) { r = sd_dhcp_client_set_request_option(link->dhcp_client, SD_DHCP_OPTION_DOMAIN_SEARCH_LIST); if (r < 0) return log_link_error_errno(link, r, "DHCP4 CLIENT: Failed to set request flag for domain search list: %m"); } if (link->network->dhcp_use_ntp) { r = sd_dhcp_client_set_request_option(link->dhcp_client, SD_DHCP_OPTION_NTP_SERVER); if (r < 0) return log_link_error_errno(link, r, "DHCP4 CLIENT: Failed to set request flag for NTP server: %m"); } if (link->network->dhcp_use_timezone) { r = sd_dhcp_client_set_request_option(link->dhcp_client, SD_DHCP_OPTION_NEW_TZDB_TIMEZONE); if (r < 0) return log_link_error_errno(link, r, "DHCP4 CLIENT: Failed to set request flag for timezone: %m"); } r = dhcp4_set_hostname(link); 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 log_link_error_errno(link, r, "DHCP4 CLIENT: Failed to set vendor class identifier: %m"); } if (link->network->dhcp_user_class) { r = sd_dhcp_client_set_user_class(link->dhcp_client, (const char **) link->network->dhcp_user_class); if (r < 0) return log_link_error_errno(link, r, "DHCP4 CLIENT: Failed to set user class: %m"); } if (link->network->dhcp_client_port) { r = sd_dhcp_client_set_client_port(link->dhcp_client, link->network->dhcp_client_port); if (r < 0) return log_link_error_errno(link, r, "DHCP4 CLIENT: Failed to set listen port: %m"); } if (link->network->dhcp_max_attempts > 0) { r = sd_dhcp_client_set_max_attempts(link->dhcp_client, link->network->dhcp_max_attempts); if (r < 0) return log_link_error_errno(link, r, "DHCP4 CLIENT: Failed to set max attempts: %m"); } return dhcp4_set_client_identifier(link); } int config_parse_dhcp_max_attempts( 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 = data; uint64_t a; int r; assert(network); assert(lvalue); assert(rvalue); if (isempty(rvalue)) { network->dhcp_max_attempts = 0; return 0; } if (streq(rvalue, "infinity")) { network->dhcp_max_attempts = (uint64_t) -1; return 0; } r = safe_atou64(rvalue, &a); if (r < 0) { log_syntax(unit, LOG_ERR, filename, line, r, "Failed to parse DHCP maximum attempts, ignoring: %s", rvalue); return 0; } if (a == 0) { log_syntax(unit, LOG_ERR, filename, line, 0, "%s= must be positive integer or 'infinity', ignoring: %s", lvalue, rvalue); return 0; } network->dhcp_max_attempts = a; return 0; } int config_parse_dhcp_black_listed_ip_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 = data; const char *p; int r; assert(filename); assert(lvalue); assert(rvalue); assert(data); if (isempty(rvalue)) { network->dhcp_black_listed_ip = set_free(network->dhcp_black_listed_ip); return 0; } for (p = rvalue;;) { _cleanup_free_ char *n = NULL; union in_addr_union ip; r = extract_first_word(&p, &n, NULL, 0); if (r < 0) { log_syntax(unit, LOG_ERR, filename, line, r, "Failed to parse DHCP black listed ip address, ignoring assignment: %s", rvalue); return 0; } if (r == 0) return 0; r = in_addr_from_string(AF_INET, n, &ip); if (r < 0) { log_syntax(unit, LOG_ERR, filename, line, r, "DHCP black listed ip address is invalid, ignoring assignment: %s", n); continue; } r = set_ensure_allocated(&network->dhcp_black_listed_ip, NULL); if (r < 0) return log_oom(); r = set_put(network->dhcp_black_listed_ip, UINT32_TO_PTR(ip.in.s_addr)); if (r < 0) log_syntax(unit, LOG_ERR, filename, line, r, "Failed to store DHCP black listed ip address '%s', ignoring assignment: %m", n); } return 0; } int config_parse_dhcp_user_class( 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 ***l = data; int r; assert(l); assert(lvalue); assert(rvalue); if (isempty(rvalue)) { *l = strv_free(*l); return 0; } for (;;) { _cleanup_free_ char *w = NULL; r = extract_first_word(&rvalue, &w, NULL, 0); if (r == -ENOMEM) return log_oom(); if (r < 0) { log_syntax(unit, LOG_ERR, filename, line, r, "Failed to split user classes option, ignoring: %s", rvalue); break; } if (r == 0) break; if (strlen(w) > 255) { log_syntax(unit, LOG_ERR, filename, line, 0, "%s length is not in the range 1-255, ignoring.", w); continue; } r = strv_push(l, w); if (r < 0) return log_oom(); w = NULL; } return 0; } static const char* const dhcp_client_identifier_table[_DHCP_CLIENT_ID_MAX] = { [DHCP_CLIENT_ID_MAC] = "mac", [DHCP_CLIENT_ID_DUID] = "duid", [DHCP_CLIENT_ID_DUID_ONLY] = "duid-only", }; DEFINE_PRIVATE_STRING_TABLE_LOOKUP_FROM_STRING(dhcp_client_identifier, DHCPClientIdentifier); DEFINE_CONFIG_PARSE_ENUM(config_parse_dhcp_client_identifier, dhcp_client_identifier, DHCPClientIdentifier, "Failed to parse client identifier type");