/* SPDX-License-Identifier: LGPL-2.1-or-later */ /*** Copyright © 2014 Intel Corporation. All rights reserved. ***/ #include #include #include #include #include "sd-ndisc.h" #include "event-util.h" #include "missing_network.h" #include "networkd-address-generation.h" #include "networkd-address.h" #include "networkd-dhcp6.h" #include "networkd-manager.h" #include "networkd-ndisc.h" #include "networkd-queue.h" #include "networkd-route.h" #include "networkd-state-file.h" #include "string-table.h" #include "string-util.h" #include "strv.h" #define NDISC_DNSSL_MAX 64U #define NDISC_RDNSS_MAX 64U bool link_ipv6_accept_ra_enabled(Link *link) { assert(link); if (!socket_ipv6_is_supported()) return false; if (link->flags & IFF_LOOPBACK) return false; if (link->iftype == ARPHRD_CAN) return false; if (!link->network) return false; if (!link_may_have_ipv6ll(link, /* check_multicast = */ true)) return false; assert(link->network->ipv6_accept_ra >= 0); return link->network->ipv6_accept_ra; } void network_adjust_ipv6_accept_ra(Network *network) { assert(network); if (!FLAGS_SET(network->link_local, ADDRESS_FAMILY_IPV6)) { if (network->ipv6_accept_ra > 0) log_warning("%s: IPv6AcceptRA= is enabled but IPv6 link-local addressing is disabled or not supported. " "Disabling IPv6AcceptRA=.", network->filename); network->ipv6_accept_ra = false; } if (network->ipv6_accept_ra < 0) /* default to accept RA if ip_forward is disabled and ignore RA if ip_forward is enabled */ network->ipv6_accept_ra = !FLAGS_SET(network->ip_forward, ADDRESS_FAMILY_IPV6); /* When RouterAllowList=, PrefixAllowList= or RouteAllowList= are specified, then * RouterDenyList=, PrefixDenyList= or RouteDenyList= are ignored, respectively. */ if (!set_isempty(network->ndisc_allow_listed_router)) network->ndisc_deny_listed_router = set_free_free(network->ndisc_deny_listed_router); if (!set_isempty(network->ndisc_allow_listed_prefix)) network->ndisc_deny_listed_prefix = set_free_free(network->ndisc_deny_listed_prefix); if (!set_isempty(network->ndisc_allow_listed_route_prefix)) network->ndisc_deny_listed_route_prefix = set_free_free(network->ndisc_deny_listed_route_prefix); } static int ndisc_check_ready(Link *link); static int ndisc_address_ready_callback(Address *address) { Address *a; assert(address); assert(address->link); SET_FOREACH(a, address->link->addresses) if (a->source == NETWORK_CONFIG_SOURCE_NDISC) a->callback = NULL; return ndisc_check_ready(address->link); } static int ndisc_check_ready(Link *link) { bool found = false, ready = false; Address *address; assert(link); if (link->ndisc_messages > 0) { log_link_debug(link, "%s(): SLAAC addresses and routes are not set.", __func__); return 0; } SET_FOREACH(address, link->addresses) { if (address->source != NETWORK_CONFIG_SOURCE_NDISC) continue; found = true; if (address_is_ready(address)) { ready = true; break; } } if (found && !ready) { SET_FOREACH(address, link->addresses) if (address->source == NETWORK_CONFIG_SOURCE_NDISC) address->callback = ndisc_address_ready_callback; log_link_debug(link, "%s(): no SLAAC address is ready.", __func__); return 0; } link->ndisc_configured = true; log_link_debug(link, "SLAAC addresses and routes set."); link_check_ready(link); return 0; } static int ndisc_route_handler(sd_netlink *rtnl, sd_netlink_message *m, Request *req, Link *link, Route *route) { int r; assert(link); r = route_configure_handler_internal(rtnl, m, link, "Could not set NDisc route"); if (r <= 0) return r; r = ndisc_check_ready(link); if (r < 0) link_enter_failed(link); return 1; } static int ndisc_request_route(Route *in, Link *link, sd_ndisc_router *rt) { _cleanup_(route_freep) Route *route = in; struct in6_addr router; bool is_new; int r; assert(route); assert(link); assert(rt); r = sd_ndisc_router_get_address(rt, &router); if (r < 0) return r; route->source = NETWORK_CONFIG_SOURCE_NDISC; route->provider.in6 = router; if (!route->table_set) route->table = link_get_ipv6_accept_ra_route_table(link); if (!route->priority_set) route->priority = link->network->ipv6_accept_ra_route_metric; if (!route->protocol_set) route->protocol = RTPROT_RA; is_new = route_get(NULL, link, route, NULL) < 0; r = link_request_route(link, TAKE_PTR(route), true, &link->ndisc_messages, ndisc_route_handler, NULL); if (r < 0) return r; if (r > 0 && is_new) link->ndisc_configured = false; return 0; } static int ndisc_address_handler(sd_netlink *rtnl, sd_netlink_message *m, Request *req, Link *link, Address *address) { int r; assert(link); r = address_configure_handler_internal(rtnl, m, link, "Could not set NDisc address"); if (r <= 0) return r; r = ndisc_check_ready(link); if (r < 0) link_enter_failed(link); return 1; } static int ndisc_request_address(Address *in, Link *link, sd_ndisc_router *rt) { _cleanup_(address_freep) Address *address = in; struct in6_addr router; bool is_new; int r; assert(address); assert(link); assert(rt); r = sd_ndisc_router_get_address(rt, &router); if (r < 0) return r; address->source = NETWORK_CONFIG_SOURCE_NDISC; address->provider.in6 = router; r = free_and_strdup_warn(&address->netlabel, link->network->ndisc_netlabel); if (r < 0) return r; is_new = address_get(link, address, NULL) < 0; r = link_request_address(link, TAKE_PTR(address), true, &link->ndisc_messages, ndisc_address_handler, NULL); if (r < 0) return r; if (r > 0 && is_new) link->ndisc_configured = false; return 0; } static int ndisc_router_process_default(Link *link, sd_ndisc_router *rt) { usec_t lifetime_usec, timestamp_usec; struct in6_addr gateway; uint16_t lifetime_sec; unsigned preference; uint32_t mtu = 0; int r; assert(link); assert(link->network); assert(rt); if (!link->network->ipv6_accept_ra_use_gateway && hashmap_isempty(link->network->routes_by_section)) return 0; r = sd_ndisc_router_get_lifetime(rt, &lifetime_sec); if (r < 0) return log_link_error_errno(link, r, "Failed to get gateway lifetime from RA: %m"); r = sd_ndisc_router_get_timestamp(rt, CLOCK_BOOTTIME, ×tamp_usec); if (r < 0) return log_link_error_errno(link, r, "Failed to get RA timestamp: %m"); lifetime_usec = sec16_to_usec(lifetime_sec, timestamp_usec); r = sd_ndisc_router_get_address(rt, &gateway); if (r < 0) return log_link_error_errno(link, r, "Failed to get gateway address from RA: %m"); if (link_get_ipv6_address(link, &gateway, 0, NULL) >= 0) { if (DEBUG_LOGGING) log_link_debug(link, "No NDisc route added, gateway %s matches local address", IN6_ADDR_TO_STRING(&gateway)); return 0; } r = sd_ndisc_router_get_preference(rt, &preference); if (r < 0) return log_link_error_errno(link, r, "Failed to get default router preference from RA: %m"); if (link->network->ipv6_accept_ra_use_mtu) { r = sd_ndisc_router_get_mtu(rt, &mtu); if (r < 0 && r != -ENODATA) return log_link_error_errno(link, r, "Failed to get default router MTU from RA: %m"); } if (link->network->ipv6_accept_ra_use_gateway) { _cleanup_(route_freep) Route *route = NULL; r = route_new(&route); if (r < 0) return log_oom(); route->family = AF_INET6; route->pref = preference; route->gw_family = AF_INET6; route->gw.in6 = gateway; route->lifetime_usec = lifetime_usec; route->mtu = mtu; r = ndisc_request_route(TAKE_PTR(route), link, rt); if (r < 0) return log_link_error_errno(link, r, "Could not request default route: %m"); } Route *route_gw; HASHMAP_FOREACH(route_gw, link->network->routes_by_section) { _cleanup_(route_freep) Route *route = NULL; if (!route_gw->gateway_from_dhcp_or_ra) continue; if (route_gw->gw_family != AF_INET6) continue; r = route_dup(route_gw, &route); if (r < 0) return r; route->gw.in6 = gateway; if (!route->pref_set) route->pref = preference; route->lifetime_usec = lifetime_usec; if (route->mtu == 0) route->mtu = mtu; r = ndisc_request_route(TAKE_PTR(route), link, rt); if (r < 0) return log_link_error_errno(link, r, "Could not request gateway: %m"); } return 0; } static int ndisc_router_process_autonomous_prefix(Link *link, sd_ndisc_router *rt) { uint32_t lifetime_valid_sec, lifetime_preferred_sec; usec_t lifetime_valid_usec, lifetime_preferred_usec, timestamp_usec; _cleanup_set_free_ Set *addresses = NULL; struct in6_addr prefix, *a; unsigned prefixlen; int r; assert(link); assert(link->network); assert(rt); if (!link->network->ipv6_accept_ra_use_autonomous_prefix) return 0; r = sd_ndisc_router_get_timestamp(rt, CLOCK_BOOTTIME, ×tamp_usec); if (r < 0) return log_link_error_errno(link, r, "Failed to get RA timestamp: %m"); r = sd_ndisc_router_prefix_get_address(rt, &prefix); if (r < 0) return log_link_error_errno(link, r, "Failed to get prefix address: %m"); r = sd_ndisc_router_prefix_get_prefixlen(rt, &prefixlen); if (r < 0) return log_link_error_errno(link, r, "Failed to get prefix length: %m"); /* ndisc_generate_addresses() below requires the prefix length <= 64. */ if (prefixlen > 64) { log_link_debug(link, "Prefix is longer than 64, ignoring autonomous prefix %s.", IN6_ADDR_PREFIX_TO_STRING(&prefix, prefixlen)); return 0; } r = sd_ndisc_router_prefix_get_valid_lifetime(rt, &lifetime_valid_sec); if (r < 0) return log_link_error_errno(link, r, "Failed to get prefix valid lifetime: %m"); r = sd_ndisc_router_prefix_get_preferred_lifetime(rt, &lifetime_preferred_sec); if (r < 0) return log_link_error_errno(link, r, "Failed to get prefix preferred lifetime: %m"); /* The preferred lifetime is never greater than the valid lifetime */ if (lifetime_preferred_sec > lifetime_valid_sec) return 0; lifetime_valid_usec = sec_to_usec(lifetime_valid_sec, timestamp_usec); lifetime_preferred_usec = sec_to_usec(lifetime_preferred_sec, timestamp_usec); r = ndisc_generate_addresses(link, &prefix, prefixlen, &addresses); if (r < 0) return log_link_error_errno(link, r, "Failed to generate SLAAC addresses: %m"); SET_FOREACH(a, addresses) { _cleanup_(address_freep) Address *address = NULL; r = address_new(&address); if (r < 0) return log_oom(); address->family = AF_INET6; address->in_addr.in6 = *a; address->prefixlen = prefixlen; address->flags = IFA_F_NOPREFIXROUTE|IFA_F_MANAGETEMPADDR; address->lifetime_valid_usec = lifetime_valid_usec; address->lifetime_preferred_usec = lifetime_preferred_usec; r = ndisc_request_address(TAKE_PTR(address), link, rt); if (r < 0) return log_link_error_errno(link, r, "Could not request SLAAC address: %m"); } return 0; } static int ndisc_router_process_onlink_prefix(Link *link, sd_ndisc_router *rt) { _cleanup_(route_freep) Route *route = NULL; usec_t timestamp_usec; uint32_t lifetime_sec; struct in6_addr prefix; unsigned prefixlen; int r; assert(link); assert(link->network); assert(rt); if (!link->network->ipv6_accept_ra_use_onlink_prefix) return 0; r = sd_ndisc_router_prefix_get_valid_lifetime(rt, &lifetime_sec); if (r < 0) return log_link_error_errno(link, r, "Failed to get prefix lifetime: %m"); r = sd_ndisc_router_get_timestamp(rt, CLOCK_BOOTTIME, ×tamp_usec); if (r < 0) return log_link_error_errno(link, r, "Failed to get RA timestamp: %m"); r = sd_ndisc_router_prefix_get_address(rt, &prefix); if (r < 0) return log_link_error_errno(link, r, "Failed to get prefix address: %m"); r = sd_ndisc_router_prefix_get_prefixlen(rt, &prefixlen); if (r < 0) return log_link_error_errno(link, r, "Failed to get prefix length: %m"); r = route_new(&route); if (r < 0) return log_oom(); route->family = AF_INET6; route->flags = RTM_F_PREFIX; route->dst.in6 = prefix; route->dst_prefixlen = prefixlen; route->lifetime_usec = sec_to_usec(lifetime_sec, timestamp_usec); r = ndisc_request_route(TAKE_PTR(route), link, rt); if (r < 0) return log_link_error_errno(link, r, "Could not request prefix route: %m"); return 0; } static int ndisc_router_process_prefix(Link *link, sd_ndisc_router *rt) { unsigned prefixlen; struct in6_addr a; uint8_t flags; int r; assert(link); assert(link->network); assert(rt); r = sd_ndisc_router_prefix_get_address(rt, &a); if (r < 0) return log_link_error_errno(link, r, "Failed to get prefix address: %m"); /* RFC 4861 Section 4.6.2: * A router SHOULD NOT send a prefix option for the link-local prefix and a host SHOULD ignore such * a prefix option. */ if (in6_addr_is_link_local(&a)) { log_link_debug(link, "Received link-local prefix, ignoring autonomous prefix."); return 0; } r = sd_ndisc_router_prefix_get_prefixlen(rt, &prefixlen); if (r < 0) return log_link_error_errno(link, r, "Failed to get prefix length: %m"); if (in6_prefix_is_filtered(&a, prefixlen, link->network->ndisc_allow_listed_prefix, link->network->ndisc_deny_listed_prefix)) { if (DEBUG_LOGGING) log_link_debug(link, "Prefix '%s' is %s, ignoring", !set_isempty(link->network->ndisc_allow_listed_prefix) ? "not in allow list" : "in deny list", IN6_ADDR_PREFIX_TO_STRING(&a, prefixlen)); return 0; } r = sd_ndisc_router_prefix_get_flags(rt, &flags); if (r < 0) return log_link_error_errno(link, r, "Failed to get RA prefix flags: %m"); if (FLAGS_SET(flags, ND_OPT_PI_FLAG_ONLINK)) { r = ndisc_router_process_onlink_prefix(link, rt); if (r < 0) return r; } if (FLAGS_SET(flags, ND_OPT_PI_FLAG_AUTO)) { r = ndisc_router_process_autonomous_prefix(link, rt); if (r < 0) return r; } return 0; } static int ndisc_router_process_route(Link *link, sd_ndisc_router *rt) { _cleanup_(route_freep) Route *route = NULL; unsigned preference, prefixlen; struct in6_addr gateway, dst; uint32_t lifetime_sec; usec_t timestamp_usec; int r; assert(link); if (!link->network->ipv6_accept_ra_use_route_prefix) return 0; r = sd_ndisc_router_route_get_lifetime(rt, &lifetime_sec); if (r < 0) return log_link_error_errno(link, r, "Failed to get route lifetime from RA: %m"); r = sd_ndisc_router_route_get_address(rt, &dst); if (r < 0) return log_link_error_errno(link, r, "Failed to get route destination address: %m"); r = sd_ndisc_router_route_get_prefixlen(rt, &prefixlen); if (r < 0) return log_link_error_errno(link, r, "Failed to get route prefix length: %m"); if (in6_addr_is_null(&dst) && prefixlen == 0) { log_link_debug(link, "Route prefix is ::/0, ignoring"); return 0; } if (in6_prefix_is_filtered(&dst, prefixlen, link->network->ndisc_allow_listed_route_prefix, link->network->ndisc_deny_listed_route_prefix)) { if (DEBUG_LOGGING) log_link_debug(link, "Route prefix %s is %s, ignoring", !set_isempty(link->network->ndisc_allow_listed_route_prefix) ? "not in allow list" : "in deny list", IN6_ADDR_PREFIX_TO_STRING(&dst, prefixlen)); return 0; } r = sd_ndisc_router_get_address(rt, &gateway); if (r < 0) return log_link_error_errno(link, r, "Failed to get gateway address from RA: %m"); if (link_get_ipv6_address(link, &gateway, 0, NULL) >= 0) { if (DEBUG_LOGGING) log_link_debug(link, "Advertised route gateway %s is local to the link, ignoring route", IN6_ADDR_TO_STRING(&gateway)); return 0; } r = sd_ndisc_router_route_get_preference(rt, &preference); if (r < 0) return log_link_error_errno(link, r, "Failed to get default router preference from RA: %m"); r = sd_ndisc_router_get_timestamp(rt, CLOCK_BOOTTIME, ×tamp_usec); if (r < 0) return log_link_error_errno(link, r, "Failed to get RA timestamp: %m"); r = route_new(&route); if (r < 0) return log_oom(); route->family = AF_INET6; route->pref = preference; route->gw.in6 = gateway; route->gw_family = AF_INET6; route->dst.in6 = dst; route->dst_prefixlen = prefixlen; route->lifetime_usec = sec_to_usec(lifetime_sec, timestamp_usec); r = ndisc_request_route(TAKE_PTR(route), link, rt); if (r < 0) return log_link_error_errno(link, r, "Could not request additional route: %m"); return 0; } static void ndisc_rdnss_hash_func(const NDiscRDNSS *x, struct siphash *state) { siphash24_compress(&x->address, sizeof(x->address), state); } static int ndisc_rdnss_compare_func(const NDiscRDNSS *a, const NDiscRDNSS *b) { return memcmp(&a->address, &b->address, sizeof(a->address)); } DEFINE_PRIVATE_HASH_OPS_WITH_KEY_DESTRUCTOR( ndisc_rdnss_hash_ops, NDiscRDNSS, ndisc_rdnss_hash_func, ndisc_rdnss_compare_func, free); static int ndisc_router_process_rdnss(Link *link, sd_ndisc_router *rt) { usec_t lifetime_usec, timestamp_usec; uint32_t lifetime_sec; const struct in6_addr *a; struct in6_addr router; bool updated = false, logged_about_too_many = false; int n, r; assert(link); assert(link->network); assert(rt); if (!link->network->ipv6_accept_ra_use_dns) return 0; r = sd_ndisc_router_get_address(rt, &router); if (r < 0) return log_link_error_errno(link, r, "Failed to get router address from RA: %m"); r = sd_ndisc_router_get_timestamp(rt, CLOCK_BOOTTIME, ×tamp_usec); if (r < 0) return log_link_error_errno(link, r, "Failed to get RA timestamp: %m"); r = sd_ndisc_router_rdnss_get_lifetime(rt, &lifetime_sec); if (r < 0) return log_link_error_errno(link, r, "Failed to get RDNSS lifetime: %m"); lifetime_usec = sec_to_usec(lifetime_sec, timestamp_usec); n = sd_ndisc_router_rdnss_get_addresses(rt, &a); if (n < 0) return log_link_error_errno(link, n, "Failed to get RDNSS addresses: %m"); for (int j = 0; j < n; j++) { _cleanup_free_ NDiscRDNSS *x = NULL; NDiscRDNSS *rdnss, d = { .address = a[j], }; if (lifetime_usec == 0) { /* The entry is outdated. */ free(set_remove(link->ndisc_rdnss, &d)); updated = true; continue; } rdnss = set_get(link->ndisc_rdnss, &d); if (rdnss) { rdnss->router = router; rdnss->lifetime_usec = lifetime_usec; continue; } if (set_size(link->ndisc_rdnss) >= NDISC_RDNSS_MAX) { if (!logged_about_too_many) log_link_warning(link, "Too many RDNSS records per link. Only first %u records will be used.", NDISC_RDNSS_MAX); logged_about_too_many = true; continue; } x = new(NDiscRDNSS, 1); if (!x) return log_oom(); *x = (NDiscRDNSS) { .address = a[j], .router = router, .lifetime_usec = lifetime_usec, }; r = set_ensure_consume(&link->ndisc_rdnss, &ndisc_rdnss_hash_ops, TAKE_PTR(x)); if (r < 0) return log_oom(); assert(r > 0); updated = true; } if (updated) link_dirty(link); return 0; } static void ndisc_dnssl_hash_func(const NDiscDNSSL *x, struct siphash *state) { siphash24_compress_string(NDISC_DNSSL_DOMAIN(x), state); } static int ndisc_dnssl_compare_func(const NDiscDNSSL *a, const NDiscDNSSL *b) { return strcmp(NDISC_DNSSL_DOMAIN(a), NDISC_DNSSL_DOMAIN(b)); } DEFINE_PRIVATE_HASH_OPS_WITH_KEY_DESTRUCTOR( ndisc_dnssl_hash_ops, NDiscDNSSL, ndisc_dnssl_hash_func, ndisc_dnssl_compare_func, free); static int ndisc_router_process_dnssl(Link *link, sd_ndisc_router *rt) { _cleanup_strv_free_ char **l = NULL; usec_t lifetime_usec, timestamp_usec; struct in6_addr router; uint32_t lifetime_sec; bool updated = false, logged_about_too_many = false; int r; assert(link); assert(link->network); assert(rt); if (link->network->ipv6_accept_ra_use_domains == DHCP_USE_DOMAINS_NO) return 0; r = sd_ndisc_router_get_address(rt, &router); if (r < 0) return log_link_error_errno(link, r, "Failed to get router address from RA: %m"); r = sd_ndisc_router_get_timestamp(rt, CLOCK_BOOTTIME, ×tamp_usec); if (r < 0) return log_link_error_errno(link, r, "Failed to get RA timestamp: %m"); r = sd_ndisc_router_dnssl_get_lifetime(rt, &lifetime_sec); if (r < 0) return log_link_error_errno(link, r, "Failed to get DNSSL lifetime: %m"); lifetime_usec = sec_to_usec(lifetime_sec, timestamp_usec); r = sd_ndisc_router_dnssl_get_domains(rt, &l); if (r < 0) return log_link_error_errno(link, r, "Failed to get DNSSL addresses: %m"); STRV_FOREACH(j, l) { _cleanup_free_ NDiscDNSSL *s = NULL; NDiscDNSSL *dnssl; s = malloc0(ALIGN(sizeof(NDiscDNSSL)) + strlen(*j) + 1); if (!s) return log_oom(); strcpy(NDISC_DNSSL_DOMAIN(s), *j); if (lifetime_usec == 0) { /* The entry is outdated. */ free(set_remove(link->ndisc_dnssl, s)); updated = true; continue; } dnssl = set_get(link->ndisc_dnssl, s); if (dnssl) { dnssl->router = router; dnssl->lifetime_usec = lifetime_usec; continue; } if (set_size(link->ndisc_dnssl) >= NDISC_DNSSL_MAX) { if (!logged_about_too_many) log_link_warning(link, "Too many DNSSL records per link. Only first %u records will be used.", NDISC_DNSSL_MAX); logged_about_too_many = true; continue; } s->router = router; s->lifetime_usec = lifetime_usec; r = set_ensure_consume(&link->ndisc_dnssl, &ndisc_dnssl_hash_ops, TAKE_PTR(s)); if (r < 0) return log_oom(); assert(r > 0); updated = true; } if (updated) link_dirty(link); return 0; } static int ndisc_router_process_options(Link *link, sd_ndisc_router *rt) { int r; assert(link); assert(link->network); assert(rt); for (r = sd_ndisc_router_option_rewind(rt); ; r = sd_ndisc_router_option_next(rt)) { uint8_t type; if (r < 0) return log_link_error_errno(link, r, "Failed to iterate through options: %m"); if (r == 0) /* EOF */ return 0; r = sd_ndisc_router_option_get_type(rt, &type); if (r < 0) return log_link_error_errno(link, r, "Failed to get RA option type: %m"); switch (type) { case SD_NDISC_OPTION_PREFIX_INFORMATION: r = ndisc_router_process_prefix(link, rt); break; case SD_NDISC_OPTION_ROUTE_INFORMATION: r = ndisc_router_process_route(link, rt); break; case SD_NDISC_OPTION_RDNSS: r = ndisc_router_process_rdnss(link, rt); break; case SD_NDISC_OPTION_DNSSL: r = ndisc_router_process_dnssl(link, rt); break; } if (r < 0 && r != -EBADMSG) return r; } } static int ndisc_drop_outdated(Link *link, usec_t timestamp_usec) { bool updated = false; NDiscDNSSL *dnssl; NDiscRDNSS *rdnss; Address *address; Route *route; int r = 0, k; assert(link); /* If an address or friends is already assigned, but not valid anymore, then refuse to update it, * and let's immediately remove it. * See RFC4862, section 5.5.3.e. But the following logic is deviated from RFC4862 by honoring all * valid lifetimes to improve the reaction of SLAAC to renumbering events. * See draft-ietf-6man-slaac-renum-02, section 4.2. */ SET_FOREACH(route, link->routes) { if (route->source != NETWORK_CONFIG_SOURCE_NDISC) continue; if (route->lifetime_usec >= timestamp_usec) continue; /* the route is still valid */ k = route_remove_and_drop(route); if (k < 0) r = log_link_warning_errno(link, k, "Failed to remove outdated SLAAC route, ignoring: %m"); } SET_FOREACH(address, link->addresses) { if (address->source != NETWORK_CONFIG_SOURCE_NDISC) continue; if (address->lifetime_valid_usec >= timestamp_usec) continue; /* the address is still valid */ k = address_remove_and_drop(address); if (k < 0) r = log_link_warning_errno(link, k, "Failed to remove outdated SLAAC address, ignoring: %m"); } SET_FOREACH(rdnss, link->ndisc_rdnss) { if (rdnss->lifetime_usec >= timestamp_usec) continue; /* the DNS server is still valid */ free(set_remove(link->ndisc_rdnss, rdnss)); updated = true; } SET_FOREACH(dnssl, link->ndisc_dnssl) { if (dnssl->lifetime_usec >= timestamp_usec) continue; /* the DNS domain is still valid */ free(set_remove(link->ndisc_dnssl, dnssl)); updated = true; } if (updated) link_dirty(link); return r; } static int ndisc_setup_expire(Link *link); static int ndisc_expire_handler(sd_event_source *s, uint64_t usec, void *userdata) { Link *link = ASSERT_PTR(userdata); usec_t now_usec; assert(link->manager); assert_se(sd_event_now(link->manager->event, CLOCK_BOOTTIME, &now_usec) >= 0); (void) ndisc_drop_outdated(link, now_usec); (void) ndisc_setup_expire(link); return 0; } static int ndisc_setup_expire(Link *link) { usec_t lifetime_usec = USEC_INFINITY; NDiscDNSSL *dnssl; NDiscRDNSS *rdnss; Address *address; Route *route; int r; assert(link); assert(link->manager); SET_FOREACH(route, link->routes) { if (route->source != NETWORK_CONFIG_SOURCE_NDISC) continue; if (!route_exists(route)) continue; lifetime_usec = MIN(lifetime_usec, route->lifetime_usec); } SET_FOREACH(address, link->addresses) { if (address->source != NETWORK_CONFIG_SOURCE_NDISC) continue; if (!address_exists(address)) continue; lifetime_usec = MIN(lifetime_usec, address->lifetime_valid_usec); } SET_FOREACH(rdnss, link->ndisc_rdnss) lifetime_usec = MIN(lifetime_usec, rdnss->lifetime_usec); SET_FOREACH(dnssl, link->ndisc_dnssl) lifetime_usec = MIN(lifetime_usec, dnssl->lifetime_usec); if (lifetime_usec == USEC_INFINITY) return 0; r = event_reset_time(link->manager->event, &link->ndisc_expire, CLOCK_BOOTTIME, lifetime_usec, 0, ndisc_expire_handler, link, 0, "ndisc-expiration", true); if (r < 0) return log_link_warning_errno(link, r, "Failed to update expiration timer for ndisc: %m"); return 0; } static int ndisc_start_dhcp6_client(Link *link, sd_ndisc_router *rt) { int r; assert(link); assert(link->network); switch (link->network->ipv6_accept_ra_start_dhcp6_client) { case IPV6_ACCEPT_RA_START_DHCP6_CLIENT_NO: return 0; case IPV6_ACCEPT_RA_START_DHCP6_CLIENT_YES: { uint64_t flags; r = sd_ndisc_router_get_flags(rt, &flags); if (r < 0) return log_link_warning_errno(link, r, "Failed to get RA flags: %m"); if ((flags & (ND_RA_FLAG_MANAGED | ND_RA_FLAG_OTHER)) == 0) return 0; /* (re)start DHCPv6 client in stateful or stateless mode according to RA flags. * Note, if both "managed" and "other configuration" bits are set, then ignore * "other configuration" bit. See RFC 4861. */ r = dhcp6_start_on_ra(link, !(flags & ND_RA_FLAG_MANAGED)); break; } case IPV6_ACCEPT_RA_START_DHCP6_CLIENT_ALWAYS: /* When IPv6AcceptRA.DHCPv6Client=always, start dhcp6 client in solicit mode * even if the router flags have neither M nor O flags. */ r = dhcp6_start_on_ra(link, /* information_request = */ false); break; default: assert_not_reached(); } if (r < 0) return log_link_error_errno(link, r, "Could not acquire DHCPv6 lease on NDisc request: %m"); log_link_debug(link, "Acquiring DHCPv6 lease on NDisc request"); return 0; } static int ndisc_router_handler(Link *link, sd_ndisc_router *rt) { struct in6_addr router; usec_t timestamp_usec; int r; assert(link); assert(link->network); assert(link->manager); assert(rt); r = sd_ndisc_router_get_address(rt, &router); if (r == -ENODATA) { log_link_debug(link, "Received RA without router address, ignoring."); return 0; } if (r < 0) return log_link_error_errno(link, r, "Failed to get router address from RA: %m"); if (in6_prefix_is_filtered(&router, 128, link->network->ndisc_allow_listed_router, link->network->ndisc_deny_listed_router)) { if (DEBUG_LOGGING) { if (!set_isempty(link->network->ndisc_allow_listed_router)) log_link_debug(link, "Router %s is not in allow list, ignoring.", IN6_ADDR_TO_STRING(&router)); else log_link_debug(link, "Router %s is in deny list, ignoring.", IN6_ADDR_TO_STRING(&router)); } return 0; } r = sd_ndisc_router_get_timestamp(rt, CLOCK_BOOTTIME, ×tamp_usec); if (r == -ENODATA) { log_link_debug(link, "Received RA without timestamp, ignoring."); return 0; } if (r < 0) return r; r = ndisc_drop_outdated(link, timestamp_usec); if (r < 0) return r; r = ndisc_start_dhcp6_client(link, rt); if (r < 0) return r; r = ndisc_router_process_default(link, rt); if (r < 0) return r; r = ndisc_router_process_options(link, rt); if (r < 0) return r; r = ndisc_setup_expire(link); if (r < 0) return r; if (link->ndisc_messages == 0) link->ndisc_configured = true; else log_link_debug(link, "Setting SLAAC addresses and router."); if (!link->ndisc_configured) link_set_state(link, LINK_STATE_CONFIGURING); link_check_ready(link); return 0; } static void ndisc_handler(sd_ndisc *nd, sd_ndisc_event_t event, sd_ndisc_router *rt, void *userdata) { Link *link = ASSERT_PTR(userdata); int r; if (IN_SET(link->state, LINK_STATE_FAILED, LINK_STATE_LINGER)) return; switch (event) { case SD_NDISC_EVENT_ROUTER: r = ndisc_router_handler(link, rt); if (r < 0 && r != -EBADMSG) { link_enter_failed(link); return; } break; case SD_NDISC_EVENT_TIMEOUT: log_link_debug(link, "NDisc handler get timeout event"); if (link->ndisc_messages == 0) { link->ndisc_configured = true; link_check_ready(link); } break; default: assert_not_reached(); } } static int ndisc_configure(Link *link) { int r; assert(link); if (!link_ipv6_accept_ra_enabled(link)) return 0; if (link->ndisc) return -EBUSY; /* Already configured. */ r = sd_ndisc_new(&link->ndisc); if (r < 0) return r; r = sd_ndisc_attach_event(link->ndisc, link->manager->event, 0); if (r < 0) return r; if (link->hw_addr.length == ETH_ALEN) { r = sd_ndisc_set_mac(link->ndisc, &link->hw_addr.ether); if (r < 0) return r; } r = sd_ndisc_set_ifindex(link->ndisc, link->ifindex); if (r < 0) return r; r = sd_ndisc_set_callback(link->ndisc, ndisc_handler, link); if (r < 0) return r; return 0; } int ndisc_start(Link *link) { int r; assert(link); if (!link->ndisc || !link->dhcp6_client) return 0; if (!link_has_carrier(link)) return 0; if (in6_addr_is_null(&link->ipv6ll_address)) return 0; log_link_debug(link, "Discovering IPv6 routers"); r = sd_ndisc_start(link->ndisc); if (r < 0) return r; return 1; } static int ndisc_process_request(Request *req, Link *link, void *userdata) { int r; assert(link); if (!link_is_ready_to_configure(link, /* allow_unmanaged = */ false)) return 0; r = ndisc_configure(link); if (r < 0) return log_link_warning_errno(link, r, "Failed to configure IPv6 Router Discovery: %m"); r = ndisc_start(link); if (r < 0) return log_link_warning_errno(link, r, "Failed to start IPv6 Router Discovery: %m"); log_link_debug(link, "IPv6 Router Discovery is configured%s.", r > 0 ? " and started" : ""); return 1; } int link_request_ndisc(Link *link) { int r; assert(link); if (!link_ipv6_accept_ra_enabled(link)) return 0; if (link->ndisc) return 0; r = link_queue_request(link, REQUEST_TYPE_NDISC, ndisc_process_request, NULL); if (r < 0) return log_link_warning_errno(link, r, "Failed to request configuring of the IPv6 Router Discovery: %m"); log_link_debug(link, "Requested configuring of the IPv6 Router Discovery."); return 0; } int ndisc_stop(Link *link) { assert(link); link->ndisc_expire = sd_event_source_disable_unref(link->ndisc_expire); return sd_ndisc_stop(link->ndisc); } void ndisc_flush(Link *link) { assert(link); /* Removes all RDNSS and DNSSL entries, without exception */ link->ndisc_rdnss = set_free(link->ndisc_rdnss); link->ndisc_dnssl = set_free(link->ndisc_dnssl); } static const char* const ipv6_accept_ra_start_dhcp6_client_table[_IPV6_ACCEPT_RA_START_DHCP6_CLIENT_MAX] = { [IPV6_ACCEPT_RA_START_DHCP6_CLIENT_NO] = "no", [IPV6_ACCEPT_RA_START_DHCP6_CLIENT_ALWAYS] = "always", [IPV6_ACCEPT_RA_START_DHCP6_CLIENT_YES] = "yes", }; DEFINE_PRIVATE_STRING_TABLE_LOOKUP_FROM_STRING_WITH_BOOLEAN(ipv6_accept_ra_start_dhcp6_client, IPv6AcceptRAStartDHCP6Client, IPV6_ACCEPT_RA_START_DHCP6_CLIENT_YES); DEFINE_CONFIG_PARSE_ENUM(config_parse_ipv6_accept_ra_use_domains, dhcp_use_domains, DHCPUseDomains, "Failed to parse UseDomains= setting"); DEFINE_CONFIG_PARSE_ENUM(config_parse_ipv6_accept_ra_start_dhcp6_client, ipv6_accept_ra_start_dhcp6_client, IPv6AcceptRAStartDHCP6Client, "Failed to parse DHCPv6Client= setting");