diff options
Diffstat (limited to 'src/resolve/resolved-link.c')
-rw-r--r-- | src/resolve/resolved-link.c | 1445 |
1 files changed, 1445 insertions, 0 deletions
diff --git a/src/resolve/resolved-link.c b/src/resolve/resolved-link.c new file mode 100644 index 0000000..dd5dadd --- /dev/null +++ b/src/resolve/resolved-link.c @@ -0,0 +1,1445 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ + +#include <linux/if.h> +#include <unistd.h> + +#include "sd-network.h" + +#include "alloc-util.h" +#include "env-file.h" +#include "fd-util.h" +#include "fileio.h" +#include "fs-util.h" +#include "log-link.h" +#include "mkdir.h" +#include "netif-util.h" +#include "parse-util.h" +#include "resolved-link.h" +#include "resolved-llmnr.h" +#include "resolved-mdns.h" +#include "socket-netlink.h" +#include "stat-util.h" +#include "string-util.h" +#include "strv.h" +#include "tmpfile-util.h" + +int link_new(Manager *m, Link **ret, int ifindex) { + _cleanup_(link_freep) Link *l = NULL; + int r; + + assert(m); + assert(ifindex > 0); + + l = new(Link, 1); + if (!l) + return -ENOMEM; + + *l = (Link) { + .ifindex = ifindex, + .default_route = -1, + .llmnr_support = RESOLVE_SUPPORT_YES, + .mdns_support = RESOLVE_SUPPORT_YES, + .dnssec_mode = _DNSSEC_MODE_INVALID, + .dns_over_tls_mode = _DNS_OVER_TLS_MODE_INVALID, + .operstate = IF_OPER_UNKNOWN, + }; + + if (asprintf(&l->state_file, "/run/systemd/resolve/netif/%i", ifindex) < 0) + return -ENOMEM; + + r = hashmap_ensure_put(&m->links, NULL, INT_TO_PTR(ifindex), l); + if (r < 0) + return r; + + l->manager = m; + + if (ret) + *ret = l; + TAKE_PTR(l); + + return 0; +} + +void link_flush_settings(Link *l) { + assert(l); + + l->default_route = -1; + l->llmnr_support = RESOLVE_SUPPORT_YES; + l->mdns_support = RESOLVE_SUPPORT_YES; + l->dnssec_mode = _DNSSEC_MODE_INVALID; + l->dns_over_tls_mode = _DNS_OVER_TLS_MODE_INVALID; + + dns_server_unlink_all(l->dns_servers); + dns_search_domain_unlink_all(l->search_domains); + + l->dnssec_negative_trust_anchors = set_free_free(l->dnssec_negative_trust_anchors); +} + +Link *link_free(Link *l) { + if (!l) + return NULL; + + /* Send goodbye messages. */ + dns_scope_announce(l->mdns_ipv4_scope, true); + dns_scope_announce(l->mdns_ipv6_scope, true); + + link_flush_settings(l); + + while (l->addresses) + (void) link_address_free(l->addresses); + + if (l->manager) + hashmap_remove(l->manager->links, INT_TO_PTR(l->ifindex)); + + dns_scope_free(l->unicast_scope); + dns_scope_free(l->llmnr_ipv4_scope); + dns_scope_free(l->llmnr_ipv6_scope); + dns_scope_free(l->mdns_ipv4_scope); + dns_scope_free(l->mdns_ipv6_scope); + + free(l->state_file); + free(l->ifname); + + return mfree(l); +} + +void link_allocate_scopes(Link *l) { + bool unicast_relevant; + int r; + + assert(l); + + /* If a link that used to be relevant is no longer, or a link that did not use to be relevant now becomes + * relevant, let's reinit the learnt global DNS server information, since we might talk to different servers + * now, even if they have the same addresses as before. */ + + unicast_relevant = link_relevant(l, AF_UNSPEC, false); + if (unicast_relevant != l->unicast_relevant) { + l->unicast_relevant = unicast_relevant; + + dns_server_reset_features_all(l->manager->fallback_dns_servers); + dns_server_reset_features_all(l->manager->dns_servers); + + /* Also, flush the global unicast scope, to deal with split horizon setups, where talking through one + * interface reveals different DNS zones than through others. */ + if (l->manager->unicast_scope) + dns_cache_flush(&l->manager->unicast_scope->cache); + } + + /* And now, allocate all scopes that makes sense now if we didn't have them yet, and drop those which we don't + * need anymore */ + + if (unicast_relevant && l->dns_servers) { + if (!l->unicast_scope) { + dns_server_reset_features_all(l->dns_servers); + + r = dns_scope_new(l->manager, &l->unicast_scope, l, DNS_PROTOCOL_DNS, AF_UNSPEC); + if (r < 0) + log_link_warning_errno(l, r, "Failed to allocate DNS scope, ignoring: %m"); + } + } else + l->unicast_scope = dns_scope_free(l->unicast_scope); + + if (link_relevant(l, AF_INET, true) && + link_get_llmnr_support(l) != RESOLVE_SUPPORT_NO) { + if (!l->llmnr_ipv4_scope) { + r = dns_scope_new(l->manager, &l->llmnr_ipv4_scope, l, DNS_PROTOCOL_LLMNR, AF_INET); + if (r < 0) + log_link_warning_errno(l, r, "Failed to allocate LLMNR IPv4 scope, ignoring: %m"); + } + } else + l->llmnr_ipv4_scope = dns_scope_free(l->llmnr_ipv4_scope); + + if (link_relevant(l, AF_INET6, true) && + link_get_llmnr_support(l) != RESOLVE_SUPPORT_NO) { + if (!l->llmnr_ipv6_scope) { + r = dns_scope_new(l->manager, &l->llmnr_ipv6_scope, l, DNS_PROTOCOL_LLMNR, AF_INET6); + if (r < 0) + log_link_warning_errno(l, r, "Failed to allocate LLMNR IPv6 scope, ignoring: %m"); + } + } else + l->llmnr_ipv6_scope = dns_scope_free(l->llmnr_ipv6_scope); + + if (link_relevant(l, AF_INET, true) && + link_get_mdns_support(l) != RESOLVE_SUPPORT_NO) { + if (!l->mdns_ipv4_scope) { + r = dns_scope_new(l->manager, &l->mdns_ipv4_scope, l, DNS_PROTOCOL_MDNS, AF_INET); + if (r < 0) + log_link_warning_errno(l, r, "Failed to allocate mDNS IPv4 scope, ignoring: %m"); + } + } else + l->mdns_ipv4_scope = dns_scope_free(l->mdns_ipv4_scope); + + if (link_relevant(l, AF_INET6, true) && + link_get_mdns_support(l) != RESOLVE_SUPPORT_NO) { + if (!l->mdns_ipv6_scope) { + r = dns_scope_new(l->manager, &l->mdns_ipv6_scope, l, DNS_PROTOCOL_MDNS, AF_INET6); + if (r < 0) + log_link_warning_errno(l, r, "Failed to allocate mDNS IPv6 scope, ignoring: %m"); + } + } else + l->mdns_ipv6_scope = dns_scope_free(l->mdns_ipv6_scope); +} + +void link_add_rrs(Link *l, bool force_remove) { + int r; + + LIST_FOREACH(addresses, a, l->addresses) + link_address_add_rrs(a, force_remove); + + if (!force_remove && + link_get_mdns_support(l) == RESOLVE_SUPPORT_YES) { + + if (l->mdns_ipv4_scope) { + r = dns_scope_add_dnssd_services(l->mdns_ipv4_scope); + if (r < 0) + log_link_warning_errno(l, r, "Failed to add IPv4 DNS-SD services, ignoring: %m"); + } + + if (l->mdns_ipv6_scope) { + r = dns_scope_add_dnssd_services(l->mdns_ipv6_scope); + if (r < 0) + log_link_warning_errno(l, r, "Failed to add IPv6 DNS-SD services, ignoring: %m"); + } + + } else { + + if (l->mdns_ipv4_scope) { + r = dns_scope_remove_dnssd_services(l->mdns_ipv4_scope); + if (r < 0) + log_link_warning_errno(l, r, "Failed to remove IPv4 DNS-SD services, ignoring: %m"); + } + + if (l->mdns_ipv6_scope) { + r = dns_scope_remove_dnssd_services(l->mdns_ipv6_scope); + if (r < 0) + log_link_warning_errno(l, r, "Failed to remove IPv6 DNS-SD services, ignoring: %m"); + } + } +} + +int link_process_rtnl(Link *l, sd_netlink_message *m) { + const char *n = NULL; + int r; + + assert(l); + assert(m); + + r = sd_rtnl_message_link_get_flags(m, &l->flags); + if (r < 0) + return r; + + (void) sd_netlink_message_read_u32(m, IFLA_MTU, &l->mtu); + (void) sd_netlink_message_read_u8(m, IFLA_OPERSTATE, &l->operstate); + + if (sd_netlink_message_read_string(m, IFLA_IFNAME, &n) >= 0 && + !streq_ptr(l->ifname, n)) { + if (l->ifname) + log_link_debug(l, "Interface name change detected: %s -> %s", l->ifname, n); + + r = free_and_strdup(&l->ifname, n); + if (r < 0) + return r; + } + + return 0; +} + +static int link_update_dns_server_one(Link *l, const char *str) { + _cleanup_free_ char *name = NULL; + int family, ifindex, r; + union in_addr_union a; + DnsServer *s; + uint16_t port; + + assert(l); + assert(str); + + r = in_addr_port_ifindex_name_from_string_auto(str, &family, &a, &port, &ifindex, &name); + if (r < 0) + return r; + + if (ifindex != 0 && ifindex != l->ifindex) + return -EINVAL; + + /* By default, the port number is determined with the transaction feature level. + * See dns_transaction_port() and dns_server_port(). */ + if (IN_SET(port, 53, 853)) + port = 0; + + s = dns_server_find(l->dns_servers, family, &a, port, 0, name); + if (s) { + dns_server_move_back_and_unmark(s); + return 0; + } + + return dns_server_new(l->manager, NULL, DNS_SERVER_LINK, l, family, &a, port, 0, name); +} + +static int link_update_dns_servers(Link *l) { + _cleanup_strv_free_ char **nameservers = NULL; + int r; + + assert(l); + + r = sd_network_link_get_dns(l->ifindex, &nameservers); + if (r == -ENODATA) { + r = 0; + goto clear; + } + if (r < 0) + goto clear; + + dns_server_mark_all(l->dns_servers); + + STRV_FOREACH(nameserver, nameservers) { + r = link_update_dns_server_one(l, *nameserver); + if (r < 0) + goto clear; + } + + dns_server_unlink_marked(l->dns_servers); + return 0; + +clear: + dns_server_unlink_all(l->dns_servers); + return r; +} + +static int link_update_default_route(Link *l) { + int r; + + assert(l); + + r = sd_network_link_get_dns_default_route(l->ifindex); + if (r == -ENODATA) { + r = 0; + goto clear; + } + if (r < 0) + goto clear; + + l->default_route = r > 0; + return 0; + +clear: + l->default_route = -1; + return r; +} + +static int link_update_llmnr_support(Link *l) { + _cleanup_free_ char *b = NULL; + int r; + + assert(l); + + l->llmnr_support = RESOLVE_SUPPORT_YES; /* yes, yes, we set it twice which is ugly */ + + r = sd_network_link_get_llmnr(l->ifindex, &b); + if (r == -ENODATA) + return 0; + if (r < 0) + return r; + + r = resolve_support_from_string(b); + if (r < 0) + return r; + + l->llmnr_support = r; + return 0; +} + +static int link_update_mdns_support(Link *l) { + _cleanup_free_ char *b = NULL; + int r; + + assert(l); + + l->mdns_support = RESOLVE_SUPPORT_YES; + + r = sd_network_link_get_mdns(l->ifindex, &b); + if (r == -ENODATA) + return 0; + if (r < 0) + return r; + + r = resolve_support_from_string(b); + if (r < 0) + return r; + + l->mdns_support = r; + return 0; +} + +void link_set_dns_over_tls_mode(Link *l, DnsOverTlsMode mode) { + + assert(l); + +#if ! ENABLE_DNS_OVER_TLS + if (mode != DNS_OVER_TLS_NO) + log_link_warning(l, + "DNS-over-TLS option for the link cannot be enabled or set to opportunistic " + "when systemd-resolved is built without DNS-over-TLS support. " + "Turning off DNS-over-TLS support."); + return; +#endif + + l->dns_over_tls_mode = mode; + l->unicast_scope = dns_scope_free(l->unicast_scope); +} + +static int link_update_dns_over_tls_mode(Link *l) { + _cleanup_free_ char *b = NULL; + int r; + + assert(l); + + l->dns_over_tls_mode = _DNS_OVER_TLS_MODE_INVALID; + + r = sd_network_link_get_dns_over_tls(l->ifindex, &b); + if (r == -ENODATA) + return 0; + if (r < 0) + return r; + + r = dns_over_tls_mode_from_string(b); + if (r < 0) + return r; + + l->dns_over_tls_mode = r; + return 0; +} + +void link_set_dnssec_mode(Link *l, DnssecMode mode) { + + assert(l); + +#if !HAVE_OPENSSL_OR_GCRYPT + if (IN_SET(mode, DNSSEC_YES, DNSSEC_ALLOW_DOWNGRADE)) + log_link_warning(l, + "DNSSEC option for the link cannot be enabled or set to allow-downgrade " + "when systemd-resolved is built without a cryptographic library. " + "Turning off DNSSEC support."); + return; +#endif + + if (l->dnssec_mode == mode) + return; + + l->dnssec_mode = mode; + l->unicast_scope = dns_scope_free(l->unicast_scope); +} + +static int link_update_dnssec_mode(Link *l) { + _cleanup_free_ char *m = NULL; + DnssecMode mode; + int r; + + assert(l); + + l->dnssec_mode = _DNSSEC_MODE_INVALID; + + r = sd_network_link_get_dnssec(l->ifindex, &m); + if (r == -ENODATA) + return 0; + if (r < 0) + return r; + + mode = dnssec_mode_from_string(m); + if (mode < 0) + return mode; + + link_set_dnssec_mode(l, mode); + return 0; +} + +static int link_update_dnssec_negative_trust_anchors(Link *l) { + _cleanup_strv_free_ char **ntas = NULL; + _cleanup_set_free_free_ Set *ns = NULL; + int r; + + assert(l); + + l->dnssec_negative_trust_anchors = set_free_free(l->dnssec_negative_trust_anchors); + + r = sd_network_link_get_dnssec_negative_trust_anchors(l->ifindex, &ntas); + if (r == -ENODATA) + return 0; + if (r < 0) + return r; + + ns = set_new(&dns_name_hash_ops); + if (!ns) + return -ENOMEM; + + r = set_put_strdupv(&ns, ntas); + if (r < 0) + return r; + + l->dnssec_negative_trust_anchors = TAKE_PTR(ns); + return 0; +} + +static int link_update_search_domain_one(Link *l, const char *name, bool route_only) { + DnsSearchDomain *d; + int r; + + assert(l); + assert(name); + + r = dns_search_domain_find(l->search_domains, name, &d); + if (r < 0) + return r; + if (r > 0) + dns_search_domain_move_back_and_unmark(d); + else { + r = dns_search_domain_new(l->manager, &d, DNS_SEARCH_DOMAIN_LINK, l, name); + if (r < 0) + return r; + } + + d->route_only = route_only; + return 0; +} + +static int link_update_search_domains(Link *l) { + _cleanup_strv_free_ char **sdomains = NULL, **rdomains = NULL; + int r, q; + + assert(l); + + r = sd_network_link_get_search_domains(l->ifindex, &sdomains); + if (r < 0 && r != -ENODATA) + goto clear; + + q = sd_network_link_get_route_domains(l->ifindex, &rdomains); + if (q < 0 && q != -ENODATA) { + r = q; + goto clear; + } + + if (r == -ENODATA && q == -ENODATA) { + /* networkd knows nothing about this interface, and that's fine. */ + r = 0; + goto clear; + } + + dns_search_domain_mark_all(l->search_domains); + + STRV_FOREACH(i, sdomains) { + r = link_update_search_domain_one(l, *i, false); + if (r < 0) + goto clear; + } + + STRV_FOREACH(i, rdomains) { + r = link_update_search_domain_one(l, *i, true); + if (r < 0) + goto clear; + } + + dns_search_domain_unlink_marked(l->search_domains); + return 0; + +clear: + dns_search_domain_unlink_all(l->search_domains); + return r; +} + +static int link_is_managed(Link *l) { + _cleanup_free_ char *state = NULL; + int r; + + assert(l); + + r = sd_network_link_get_setup_state(l->ifindex, &state); + if (r == -ENODATA) + return 0; + if (r < 0) + return r; + + return !STR_IN_SET(state, "pending", "initialized", "unmanaged"); +} + +static void link_enter_unmanaged(Link *l) { + assert(l); + + /* If this link used to be managed, but is now unmanaged, flush all our settings — but only once. */ + if (l->is_managed) + link_flush_settings(l); + + l->is_managed = false; +} + +static void link_read_settings(Link *l) { + struct stat st; + int r; + + assert(l); + + /* Read settings from networkd, except when networkd is not managing this interface. */ + + r = sd_network_link_get_stat(l->ifindex, &st); + if (r == -ENOENT) + return link_enter_unmanaged(l); + if (r < 0) + return (void) log_link_warning_errno(l, r, "Failed to stat() networkd's link state file, ignoring: %m"); + + if (stat_inode_unmodified(&l->networkd_state_file_stat, &st)) + /* The state file is unmodified. Not necessary to re-read settings. */ + return; + + /* Save the new stat for the next event. */ + l->networkd_state_file_stat = st; + + r = link_is_managed(l); + if (r < 0) + return (void) log_link_warning_errno(l, r, "Failed to determine whether the interface is managed, ignoring: %m"); + if (r == 0) + return link_enter_unmanaged(l); + + l->is_managed = true; + + r = network_link_get_operational_state(l->ifindex, &l->networkd_operstate); + if (r < 0) + log_link_warning_errno(l, r, "Failed to read networkd's link operational state, ignoring: %m"); + + r = link_update_dns_servers(l); + if (r < 0) + log_link_warning_errno(l, r, "Failed to read DNS servers for the interface, ignoring: %m"); + + r = link_update_llmnr_support(l); + if (r < 0) + log_link_warning_errno(l, r, "Failed to read LLMNR support for the interface, ignoring: %m"); + + r = link_update_mdns_support(l); + if (r < 0) + log_link_warning_errno(l, r, "Failed to read mDNS support for the interface, ignoring: %m"); + + r = link_update_dns_over_tls_mode(l); + if (r < 0) + log_link_warning_errno(l, r, "Failed to read DNS-over-TLS mode for the interface, ignoring: %m"); + + r = link_update_dnssec_mode(l); + if (r < 0) + log_link_warning_errno(l, r, "Failed to read DNSSEC mode for the interface, ignoring: %m"); + + r = link_update_dnssec_negative_trust_anchors(l); + if (r < 0) + log_link_warning_errno(l, r, "Failed to read DNSSEC negative trust anchors for the interface, ignoring: %m"); + + r = link_update_search_domains(l); + if (r < 0) + log_link_warning_errno(l, r, "Failed to read search domains for the interface, ignoring: %m"); + + r = link_update_default_route(l); + if (r < 0) + log_link_warning_errno(l, r, "Failed to read default route setting for the interface, proceeding anyway: %m"); +} + +int link_update(Link *l) { + int r; + + assert(l); + + link_read_settings(l); + r = link_load_user(l); + if (r < 0) + return r; + + if (link_get_llmnr_support(l) != RESOLVE_SUPPORT_NO) { + r = manager_llmnr_start(l->manager); + if (r < 0) + return r; + } + + if (link_get_mdns_support(l) != RESOLVE_SUPPORT_NO) { + r = manager_mdns_start(l->manager); + if (r < 0) + return r; + } + + link_allocate_scopes(l); + link_add_rrs(l, false); + + return 0; +} + +bool link_relevant(Link *l, int family, bool local_multicast) { + assert(l); + + /* A link is relevant for local multicast traffic if it isn't a loopback device, has a link + * beat, can do multicast and has at least one link-local (or better) IP address. + * + * A link is relevant for non-multicast traffic if it isn't a loopback device, has a link beat, and has at + * least one routable address. */ + + if ((l->flags & (IFF_LOOPBACK | IFF_DORMANT)) != 0) + return false; + + if (!FLAGS_SET(l->flags, IFF_UP | IFF_LOWER_UP)) + return false; + + if (local_multicast && + !FLAGS_SET(l->flags, IFF_MULTICAST)) + return false; + + if (!netif_has_carrier(l->operstate, l->flags)) + return false; + + if (l->is_managed && + !IN_SET(l->networkd_operstate, LINK_OPERSTATE_DEGRADED_CARRIER, LINK_OPERSTATE_DEGRADED, LINK_OPERSTATE_ROUTABLE)) + return false; + + LIST_FOREACH(addresses, a, l->addresses) + if ((family == AF_UNSPEC || a->family == family) && link_address_relevant(a, local_multicast)) + return true; + + return false; +} + +LinkAddress *link_find_address(Link *l, int family, const union in_addr_union *in_addr) { + assert(l); + + if (!IN_SET(family, AF_INET, AF_INET6)) + return NULL; + + if (!in_addr) + return NULL; + + LIST_FOREACH(addresses, a, l->addresses) + if (a->family == family && in_addr_equal(family, &a->in_addr, in_addr)) + return a; + + return NULL; +} + +DnsServer* link_set_dns_server(Link *l, DnsServer *s) { + assert(l); + + if (l->current_dns_server == s) + return s; + + if (s) + log_link_debug(l, "Switching to DNS server %s.", strna(dns_server_string_full(s))); + + dns_server_unref(l->current_dns_server); + l->current_dns_server = dns_server_ref(s); + + /* Skip flushing the cache if server stale feature is enabled. */ + if (l->unicast_scope && l->manager->stale_retention_usec == 0) + dns_cache_flush(&l->unicast_scope->cache); + + return s; +} + +DnsServer *link_get_dns_server(Link *l) { + assert(l); + + if (!l->current_dns_server) + link_set_dns_server(l, l->dns_servers); + + return l->current_dns_server; +} + +void link_next_dns_server(Link *l, DnsServer *if_current) { + assert(l); + + /* If the current server of the transaction is specified, and we already are at a different one, + * don't do anything */ + if (if_current && l->current_dns_server != if_current) + return; + + /* If currently have no DNS server, then don't do anything, we'll pick it lazily the next time a DNS + * server is needed. */ + if (!l->current_dns_server) + return; + + /* Change to the next one, but make sure to follow the linked list only if this server is actually + * still linked. */ + if (l->current_dns_server->linked && l->current_dns_server->servers_next) { + link_set_dns_server(l, l->current_dns_server->servers_next); + return; + } + + /* Pick the first one again, after we reached the end */ + link_set_dns_server(l, l->dns_servers); +} + +DnsOverTlsMode link_get_dns_over_tls_mode(Link *l) { + assert(l); + + if (l->dns_over_tls_mode != _DNS_OVER_TLS_MODE_INVALID) + return l->dns_over_tls_mode; + + return manager_get_dns_over_tls_mode(l->manager); +} + +DnssecMode link_get_dnssec_mode(Link *l) { + assert(l); + + if (l->dnssec_mode != _DNSSEC_MODE_INVALID) + return l->dnssec_mode; + + return manager_get_dnssec_mode(l->manager); +} + +bool link_dnssec_supported(Link *l) { + DnsServer *server; + + assert(l); + + if (link_get_dnssec_mode(l) == DNSSEC_NO) + return false; + + server = link_get_dns_server(l); + if (server) + return dns_server_dnssec_supported(server); + + return true; +} + +ResolveSupport link_get_llmnr_support(Link *link) { + assert(link); + assert(link->manager); + + /* This provides the effective LLMNR support level for the link, instead of the 'internal' per-link setting. */ + + return MIN(link->llmnr_support, link->manager->llmnr_support); +} + +ResolveSupport link_get_mdns_support(Link *link) { + assert(link); + assert(link->manager); + + /* This provides the effective mDNS support level for the link, instead of the 'internal' per-link setting. */ + + return MIN(link->mdns_support, link->manager->mdns_support); +} + +int link_address_new(Link *l, + LinkAddress **ret, + int family, + const union in_addr_union *in_addr, + const union in_addr_union *in_addr_broadcast) { + LinkAddress *a; + + assert(l); + assert(in_addr); + + a = new(LinkAddress, 1); + if (!a) + return -ENOMEM; + + *a = (LinkAddress) { + .family = family, + .in_addr = *in_addr, + .in_addr_broadcast = *in_addr_broadcast, + .link = l, + .prefixlen = UCHAR_MAX, + }; + + LIST_PREPEND(addresses, l->addresses, a); + l->n_addresses++; + + if (ret) + *ret = a; + + return 0; +} + +LinkAddress *link_address_free(LinkAddress *a) { + if (!a) + return NULL; + + if (a->link) { + LIST_REMOVE(addresses, a->link->addresses, a); + + assert(a->link->n_addresses > 0); + a->link->n_addresses--; + + if (a->llmnr_address_rr) { + if (a->family == AF_INET && a->link->llmnr_ipv4_scope) + dns_zone_remove_rr(&a->link->llmnr_ipv4_scope->zone, a->llmnr_address_rr); + else if (a->family == AF_INET6 && a->link->llmnr_ipv6_scope) + dns_zone_remove_rr(&a->link->llmnr_ipv6_scope->zone, a->llmnr_address_rr); + } + + if (a->llmnr_ptr_rr) { + if (a->family == AF_INET && a->link->llmnr_ipv4_scope) + dns_zone_remove_rr(&a->link->llmnr_ipv4_scope->zone, a->llmnr_ptr_rr); + else if (a->family == AF_INET6 && a->link->llmnr_ipv6_scope) + dns_zone_remove_rr(&a->link->llmnr_ipv6_scope->zone, a->llmnr_ptr_rr); + } + + if (a->mdns_address_rr) { + if (a->family == AF_INET && a->link->mdns_ipv4_scope) + dns_zone_remove_rr(&a->link->mdns_ipv4_scope->zone, a->mdns_address_rr); + else if (a->family == AF_INET6 && a->link->mdns_ipv6_scope) + dns_zone_remove_rr(&a->link->mdns_ipv6_scope->zone, a->mdns_address_rr); + } + + if (a->mdns_ptr_rr) { + if (a->family == AF_INET && a->link->mdns_ipv4_scope) + dns_zone_remove_rr(&a->link->mdns_ipv4_scope->zone, a->mdns_ptr_rr); + else if (a->family == AF_INET6 && a->link->mdns_ipv6_scope) + dns_zone_remove_rr(&a->link->mdns_ipv6_scope->zone, a->mdns_ptr_rr); + } + } + + dns_resource_record_unref(a->llmnr_address_rr); + dns_resource_record_unref(a->llmnr_ptr_rr); + dns_resource_record_unref(a->mdns_address_rr); + dns_resource_record_unref(a->mdns_ptr_rr); + + return mfree(a); +} + +void link_address_add_rrs(LinkAddress *a, bool force_remove) { + int r; + + assert(a); + + if (a->family == AF_INET) { + + if (!force_remove && + link_address_relevant(a, true) && + a->link->llmnr_ipv4_scope && + link_get_llmnr_support(a->link) == RESOLVE_SUPPORT_YES) { + + if (!a->link->manager->llmnr_host_ipv4_key) { + a->link->manager->llmnr_host_ipv4_key = dns_resource_key_new(DNS_CLASS_IN, DNS_TYPE_A, a->link->manager->llmnr_hostname); + if (!a->link->manager->llmnr_host_ipv4_key) { + r = -ENOMEM; + goto fail; + } + } + + if (!a->llmnr_address_rr) { + a->llmnr_address_rr = dns_resource_record_new(a->link->manager->llmnr_host_ipv4_key); + if (!a->llmnr_address_rr) { + r = -ENOMEM; + goto fail; + } + + a->llmnr_address_rr->a.in_addr = a->in_addr.in; + a->llmnr_address_rr->ttl = LLMNR_DEFAULT_TTL; + } + + if (!a->llmnr_ptr_rr) { + r = dns_resource_record_new_reverse(&a->llmnr_ptr_rr, a->family, &a->in_addr, a->link->manager->llmnr_hostname); + if (r < 0) + goto fail; + + a->llmnr_ptr_rr->ttl = LLMNR_DEFAULT_TTL; + } + + r = dns_zone_put(&a->link->llmnr_ipv4_scope->zone, a->link->llmnr_ipv4_scope, a->llmnr_address_rr, true); + if (r < 0) + log_link_warning_errno(a->link, r, "Failed to add A record to LLMNR zone, ignoring: %m"); + + r = dns_zone_put(&a->link->llmnr_ipv4_scope->zone, a->link->llmnr_ipv4_scope, a->llmnr_ptr_rr, false); + if (r < 0) + log_link_warning_errno(a->link, r, "Failed to add IPv4 PTR record to LLMNR zone, ignoring: %m"); + } else { + if (a->llmnr_address_rr) { + if (a->link->llmnr_ipv4_scope) + dns_zone_remove_rr(&a->link->llmnr_ipv4_scope->zone, a->llmnr_address_rr); + a->llmnr_address_rr = dns_resource_record_unref(a->llmnr_address_rr); + } + + if (a->llmnr_ptr_rr) { + if (a->link->llmnr_ipv4_scope) + dns_zone_remove_rr(&a->link->llmnr_ipv4_scope->zone, a->llmnr_ptr_rr); + a->llmnr_ptr_rr = dns_resource_record_unref(a->llmnr_ptr_rr); + } + } + + if (!force_remove && + link_address_relevant(a, true) && + a->link->mdns_ipv4_scope && + link_get_mdns_support(a->link) == RESOLVE_SUPPORT_YES) { + if (!a->link->manager->mdns_host_ipv4_key) { + a->link->manager->mdns_host_ipv4_key = dns_resource_key_new(DNS_CLASS_IN, DNS_TYPE_A, a->link->manager->mdns_hostname); + if (!a->link->manager->mdns_host_ipv4_key) { + r = -ENOMEM; + goto fail; + } + } + + if (!a->mdns_address_rr) { + a->mdns_address_rr = dns_resource_record_new(a->link->manager->mdns_host_ipv4_key); + if (!a->mdns_address_rr) { + r = -ENOMEM; + goto fail; + } + + a->mdns_address_rr->a.in_addr = a->in_addr.in; + a->mdns_address_rr->ttl = MDNS_DEFAULT_TTL; + } + + if (!a->mdns_ptr_rr) { + r = dns_resource_record_new_reverse(&a->mdns_ptr_rr, a->family, &a->in_addr, a->link->manager->mdns_hostname); + if (r < 0) + goto fail; + + a->mdns_ptr_rr->ttl = MDNS_DEFAULT_TTL; + } + + r = dns_zone_put(&a->link->mdns_ipv4_scope->zone, a->link->mdns_ipv4_scope, a->mdns_address_rr, true); + if (r < 0) + log_link_warning_errno(a->link, r, "Failed to add A record to MDNS zone, ignoring: %m"); + + r = dns_zone_put(&a->link->mdns_ipv4_scope->zone, a->link->mdns_ipv4_scope, a->mdns_ptr_rr, false); + if (r < 0) + log_link_warning_errno(a->link, r, "Failed to add IPv4 PTR record to MDNS zone, ignoring: %m"); + } else { + if (a->mdns_address_rr) { + if (a->link->mdns_ipv4_scope) + dns_zone_remove_rr(&a->link->mdns_ipv4_scope->zone, a->mdns_address_rr); + a->mdns_address_rr = dns_resource_record_unref(a->mdns_address_rr); + } + + if (a->mdns_ptr_rr) { + if (a->link->mdns_ipv4_scope) + dns_zone_remove_rr(&a->link->mdns_ipv4_scope->zone, a->mdns_ptr_rr); + a->mdns_ptr_rr = dns_resource_record_unref(a->mdns_ptr_rr); + } + } + } + + if (a->family == AF_INET6) { + + if (!force_remove && + link_address_relevant(a, true) && + a->link->llmnr_ipv6_scope && + link_get_llmnr_support(a->link) == RESOLVE_SUPPORT_YES) { + + if (!a->link->manager->llmnr_host_ipv6_key) { + a->link->manager->llmnr_host_ipv6_key = dns_resource_key_new(DNS_CLASS_IN, DNS_TYPE_AAAA, a->link->manager->llmnr_hostname); + if (!a->link->manager->llmnr_host_ipv6_key) { + r = -ENOMEM; + goto fail; + } + } + + if (!a->llmnr_address_rr) { + a->llmnr_address_rr = dns_resource_record_new(a->link->manager->llmnr_host_ipv6_key); + if (!a->llmnr_address_rr) { + r = -ENOMEM; + goto fail; + } + + a->llmnr_address_rr->aaaa.in6_addr = a->in_addr.in6; + a->llmnr_address_rr->ttl = LLMNR_DEFAULT_TTL; + } + + if (!a->llmnr_ptr_rr) { + r = dns_resource_record_new_reverse(&a->llmnr_ptr_rr, a->family, &a->in_addr, a->link->manager->llmnr_hostname); + if (r < 0) + goto fail; + + a->llmnr_ptr_rr->ttl = LLMNR_DEFAULT_TTL; + } + + r = dns_zone_put(&a->link->llmnr_ipv6_scope->zone, a->link->llmnr_ipv6_scope, a->llmnr_address_rr, true); + if (r < 0) + log_link_warning_errno(a->link, r, "Failed to add AAAA record to LLMNR zone, ignoring: %m"); + + r = dns_zone_put(&a->link->llmnr_ipv6_scope->zone, a->link->llmnr_ipv6_scope, a->llmnr_ptr_rr, false); + if (r < 0) + log_link_warning_errno(a->link, r, "Failed to add IPv6 PTR record to LLMNR zone, ignoring: %m"); + } else { + if (a->llmnr_address_rr) { + if (a->link->llmnr_ipv6_scope) + dns_zone_remove_rr(&a->link->llmnr_ipv6_scope->zone, a->llmnr_address_rr); + a->llmnr_address_rr = dns_resource_record_unref(a->llmnr_address_rr); + } + + if (a->llmnr_ptr_rr) { + if (a->link->llmnr_ipv6_scope) + dns_zone_remove_rr(&a->link->llmnr_ipv6_scope->zone, a->llmnr_ptr_rr); + a->llmnr_ptr_rr = dns_resource_record_unref(a->llmnr_ptr_rr); + } + } + + if (!force_remove && + link_address_relevant(a, true) && + a->link->mdns_ipv6_scope && + link_get_mdns_support(a->link) == RESOLVE_SUPPORT_YES) { + + if (!a->link->manager->mdns_host_ipv6_key) { + a->link->manager->mdns_host_ipv6_key = dns_resource_key_new(DNS_CLASS_IN, DNS_TYPE_AAAA, a->link->manager->mdns_hostname); + if (!a->link->manager->mdns_host_ipv6_key) { + r = -ENOMEM; + goto fail; + } + } + + if (!a->mdns_address_rr) { + a->mdns_address_rr = dns_resource_record_new(a->link->manager->mdns_host_ipv6_key); + if (!a->mdns_address_rr) { + r = -ENOMEM; + goto fail; + } + + a->mdns_address_rr->aaaa.in6_addr = a->in_addr.in6; + a->mdns_address_rr->ttl = MDNS_DEFAULT_TTL; + } + + if (!a->mdns_ptr_rr) { + r = dns_resource_record_new_reverse(&a->mdns_ptr_rr, a->family, &a->in_addr, a->link->manager->mdns_hostname); + if (r < 0) + goto fail; + + a->mdns_ptr_rr->ttl = MDNS_DEFAULT_TTL; + } + + r = dns_zone_put(&a->link->mdns_ipv6_scope->zone, a->link->mdns_ipv6_scope, a->mdns_address_rr, true); + if (r < 0) + log_link_warning_errno(a->link, r, "Failed to add AAAA record to MDNS zone, ignoring: %m"); + + r = dns_zone_put(&a->link->mdns_ipv6_scope->zone, a->link->mdns_ipv6_scope, a->mdns_ptr_rr, false); + if (r < 0) + log_link_warning_errno(a->link, r, "Failed to add IPv6 PTR record to MDNS zone, ignoring: %m"); + } else { + if (a->mdns_address_rr) { + if (a->link->mdns_ipv6_scope) + dns_zone_remove_rr(&a->link->mdns_ipv6_scope->zone, a->mdns_address_rr); + a->mdns_address_rr = dns_resource_record_unref(a->mdns_address_rr); + } + + if (a->mdns_ptr_rr) { + if (a->link->mdns_ipv6_scope) + dns_zone_remove_rr(&a->link->mdns_ipv6_scope->zone, a->mdns_ptr_rr); + a->mdns_ptr_rr = dns_resource_record_unref(a->mdns_ptr_rr); + } + } + } + + return; + +fail: + log_link_debug_errno(a->link, r, "Failed to update address RRs, ignoring: %m"); +} + +int link_address_update_rtnl(LinkAddress *a, sd_netlink_message *m) { + int r; + + assert(a); + assert(m); + + r = sd_rtnl_message_addr_get_flags(m, &a->flags); + if (r < 0) + return r; + + (void) sd_rtnl_message_addr_get_prefixlen(m, &a->prefixlen); + (void) sd_rtnl_message_addr_get_scope(m, &a->scope); + + link_allocate_scopes(a->link); + link_add_rrs(a->link, false); + + return 0; +} + +bool link_address_relevant(LinkAddress *a, bool local_multicast) { + assert(a); + + if (a->flags & (IFA_F_DEPRECATED|IFA_F_TENTATIVE)) + return false; + + if (a->scope >= (local_multicast ? RT_SCOPE_HOST : RT_SCOPE_LINK)) + return false; + + return true; +} + +static bool link_needs_save(Link *l) { + assert(l); + + /* Returns true if any of the settings where set different from the default */ + + if (l->is_managed) + return false; + + if (l->llmnr_support != RESOLVE_SUPPORT_YES || + l->mdns_support != RESOLVE_SUPPORT_YES || + l->dnssec_mode != _DNSSEC_MODE_INVALID || + l->dns_over_tls_mode != _DNS_OVER_TLS_MODE_INVALID) + return true; + + if (l->dns_servers || + l->search_domains) + return true; + + if (!set_isempty(l->dnssec_negative_trust_anchors)) + return true; + + if (l->default_route >= 0) + return true; + + return false; +} + +int link_save_user(Link *l) { + _cleanup_(unlink_and_freep) char *temp_path = NULL; + _cleanup_fclose_ FILE *f = NULL; + const char *v; + int r; + + assert(l); + assert(l->state_file); + + if (!link_needs_save(l)) { + (void) unlink(l->state_file); + return 0; + } + + r = mkdir_parents(l->state_file, 0700); + if (r < 0) + goto fail; + + r = fopen_temporary(l->state_file, &f, &temp_path); + if (r < 0) + goto fail; + + (void) fchmod(fileno(f), 0644); + + fputs("# This is private data. Do not parse.\n", f); + + v = resolve_support_to_string(l->llmnr_support); + if (v) + fprintf(f, "LLMNR=%s\n", v); + + v = resolve_support_to_string(l->mdns_support); + if (v) + fprintf(f, "MDNS=%s\n", v); + + v = dnssec_mode_to_string(l->dnssec_mode); + if (v) + fprintf(f, "DNSSEC=%s\n", v); + + v = dns_over_tls_mode_to_string(l->dns_over_tls_mode); + if (v) + fprintf(f, "DNSOVERTLS=%s\n", v); + + if (l->default_route >= 0) + fprintf(f, "DEFAULT_ROUTE=%s\n", yes_no(l->default_route)); + + if (l->dns_servers) { + fputs("SERVERS=", f); + LIST_FOREACH(servers, server, l->dns_servers) { + + if (server != l->dns_servers) + fputc(' ', f); + + v = dns_server_string_full(server); + if (!v) { + r = -ENOMEM; + goto fail; + } + + fputs(v, f); + } + fputc('\n', f); + } + + if (l->search_domains) { + fputs("DOMAINS=", f); + LIST_FOREACH(domains, domain, l->search_domains) { + + if (domain != l->search_domains) + fputc(' ', f); + + if (domain->route_only) + fputc('~', f); + + fputs(DNS_SEARCH_DOMAIN_NAME(domain), f); + } + fputc('\n', f); + } + + if (!set_isempty(l->dnssec_negative_trust_anchors)) { + bool space = false; + char *nta; + + fputs("NTAS=", f); + SET_FOREACH(nta, l->dnssec_negative_trust_anchors) { + + if (space) + fputc(' ', f); + + fputs(nta, f); + space = true; + } + fputc('\n', f); + } + + r = fflush_and_check(f); + if (r < 0) + goto fail; + + if (rename(temp_path, l->state_file) < 0) { + r = -errno; + goto fail; + } + + temp_path = mfree(temp_path); + + return 0; + +fail: + (void) unlink(l->state_file); + + return log_link_error_errno(l, r, "Failed to save link data %s: %m", l->state_file); +} + +int link_load_user(Link *l) { + _cleanup_free_ char + *llmnr = NULL, + *mdns = NULL, + *dnssec = NULL, + *dns_over_tls = NULL, + *servers = NULL, + *domains = NULL, + *ntas = NULL, + *default_route = NULL; + + ResolveSupport s; + const char *p; + int r; + + assert(l); + assert(l->state_file); + + /* Try to load only a single time */ + if (l->loaded) + return 0; + l->loaded = true; + + if (l->is_managed) + return 0; /* if the device is managed, then networkd is our configuration source, not the bus API */ + + r = parse_env_file(NULL, l->state_file, + "LLMNR", &llmnr, + "MDNS", &mdns, + "DNSSEC", &dnssec, + "DNSOVERTLS", &dns_over_tls, + "SERVERS", &servers, + "DOMAINS", &domains, + "NTAS", &ntas, + "DEFAULT_ROUTE", &default_route); + if (r == -ENOENT) + return 0; + if (r < 0) + goto fail; + + link_flush_settings(l); + + /* If we can't recognize the LLMNR or MDNS setting we don't override the default */ + s = resolve_support_from_string(llmnr); + if (s >= 0) + l->llmnr_support = s; + + s = resolve_support_from_string(mdns); + if (s >= 0) + l->mdns_support = s; + + r = parse_boolean(default_route); + if (r >= 0) + l->default_route = r; + + /* If we can't recognize the DNSSEC setting, then set it to invalid, so that the daemon default is used. */ + l->dnssec_mode = dnssec_mode_from_string(dnssec); + + /* Same for DNSOverTLS */ + l->dns_over_tls_mode = dns_over_tls_mode_from_string(dns_over_tls); + + for (p = servers;;) { + _cleanup_free_ char *word = NULL; + + r = extract_first_word(&p, &word, NULL, 0); + if (r < 0) + goto fail; + if (r == 0) + break; + + r = link_update_dns_server_one(l, word); + if (r < 0) { + log_link_debug_errno(l, r, "Failed to load DNS server '%s', ignoring: %m", word); + continue; + } + } + + for (p = domains;;) { + _cleanup_free_ char *word = NULL; + const char *n; + bool is_route; + + r = extract_first_word(&p, &word, NULL, 0); + if (r < 0) + goto fail; + if (r == 0) + break; + + is_route = word[0] == '~'; + n = is_route ? word + 1 : word; + + r = link_update_search_domain_one(l, n, is_route); + if (r < 0) { + log_link_debug_errno(l, r, "Failed to load search domain '%s', ignoring: %m", word); + continue; + } + } + + if (ntas) { + _cleanup_set_free_free_ Set *ns = NULL; + + ns = set_new(&dns_name_hash_ops); + if (!ns) { + r = -ENOMEM; + goto fail; + } + + r = set_put_strsplit(ns, ntas, NULL, 0); + if (r < 0) + goto fail; + + l->dnssec_negative_trust_anchors = TAKE_PTR(ns); + } + + return 0; + +fail: + return log_link_error_errno(l, r, "Failed to load link data %s: %m", l->state_file); +} + +void link_remove_user(Link *l) { + assert(l); + assert(l->state_file); + + (void) unlink(l->state_file); +} + +bool link_negative_trust_anchor_lookup(Link *l, const char *name) { + int r; + + assert(l); + assert(name); + + /* Checks whether the specified domain (or any of its parent domains) are listed as per-link NTA. */ + + for (;;) { + if (set_contains(l->dnssec_negative_trust_anchors, name)) + return true; + + /* And now, let's look at the parent, and check that too */ + r = dns_name_parent(&name); + if (r < 0) + return r; + if (r == 0) + break; + } + + return false; +} |