From 943ef07ce0aacbee93c721e461c02d651ee9ef6a Mon Sep 17 00:00:00 2001 From: Lennart Poettering Date: Wed, 15 Jun 2016 22:38:23 +0200 Subject: resolved: make sure DNS configuration pushed in by the user stays around on restarts Let's make sure that all settings pushed in stay around when systemd-resolved is restarted. --- src/resolve/resolved-link-bus.c | 11 ++ src/resolve/resolved-link.c | 271 +++++++++++++++++++++++++++++++++++++++- src/resolve/resolved-link.h | 11 +- src/resolve/resolved-manager.c | 65 +++++++++- src/resolve/resolved-manager.h | 2 + 5 files changed, 353 insertions(+), 7 deletions(-) (limited to 'src/resolve') diff --git a/src/resolve/resolved-link-bus.c b/src/resolve/resolved-link-bus.c index 07726c7d9e..acce8682de 100644 --- a/src/resolve/resolved-link-bus.c +++ b/src/resolve/resolved-link-bus.c @@ -265,6 +265,7 @@ int bus_link_method_set_dns_servers(sd_bus_message *message, void *userdata, sd_ dns_server_unlink_marked(l->dns_servers); link_allocate_scopes(l); + (void) link_save_user(l); (void) manager_write_resolv_conf(l->manager); return sd_bus_reply_method_return(message, NULL); @@ -346,6 +347,7 @@ int bus_link_method_set_domains(sd_bus_message *message, void *userdata, sd_bus_ dns_search_domain_unlink_marked(l->search_domains); + (void) link_save_user(l); (void) manager_write_resolv_conf(l->manager); return sd_bus_reply_method_return(message, NULL); @@ -384,6 +386,8 @@ int bus_link_method_set_llmnr(sd_bus_message *message, void *userdata, sd_bus_er link_allocate_scopes(l); link_add_rrs(l, false); + (void) link_save_user(l); + return sd_bus_reply_method_return(message, NULL); } @@ -416,6 +420,8 @@ int bus_link_method_set_mdns(sd_bus_message *message, void *userdata, sd_bus_err link_allocate_scopes(l); link_add_rrs(l, false); + (void) link_save_user(l); + return sd_bus_reply_method_return(message, NULL); } @@ -446,6 +452,8 @@ int bus_link_method_set_dnssec(sd_bus_message *message, void *userdata, sd_bus_e link_set_dnssec_mode(l, mode); + (void) link_save_user(l); + return sd_bus_reply_method_return(message, NULL); } @@ -489,6 +497,8 @@ int bus_link_method_set_dnssec_negative_trust_anchors(sd_bus_message *message, v l->dnssec_negative_trust_anchors = ns; ns = NULL; + (void) link_save_user(l); + return sd_bus_reply_method_return(message, NULL); } @@ -507,6 +517,7 @@ int bus_link_method_revert(sd_bus_message *message, void *userdata, sd_bus_error link_allocate_scopes(l); link_add_rrs(l, false); + (void) link_save_user(l); (void) manager_write_resolv_conf(l->manager); return sd_bus_reply_method_return(message, NULL); diff --git a/src/resolve/resolved-link.c b/src/resolve/resolved-link.c index b321aefda9..ea4a007139 100644 --- a/src/resolve/resolved-link.c +++ b/src/resolve/resolved-link.c @@ -22,7 +22,10 @@ #include "sd-network.h" #include "alloc-util.h" +#include "fd-util.h" +#include "fileio.h" #include "missing.h" +#include "mkdir.h" #include "parse-util.h" #include "resolved-link.h" #include "string-util.h" @@ -49,6 +52,9 @@ int link_new(Manager *m, Link **ret, int ifindex) { l->dnssec_mode = _DNSSEC_MODE_INVALID; l->operstate = IF_OPER_UNKNOWN; + if (asprintf(&l->state_file, "/run/systemd/resolve/netif/%i", ifindex) < 0) + return -ENOMEM; + r = hashmap_put(m->links, INT_TO_PTR(ifindex), l); if (r < 0) return r; @@ -93,6 +99,8 @@ Link *link_free(Link *l) { dns_scope_free(l->mdns_ipv4_scope); dns_scope_free(l->mdns_ipv6_scope); + free(l->state_file); + free(l); return NULL; } @@ -165,7 +173,7 @@ void link_add_rrs(Link *l, bool force_remove) { link_address_add_rrs(a, force_remove); } -int link_update_rtnl(Link *l, sd_netlink_message *m) { +int link_process_rtnl(Link *l, sd_netlink_message *m) { const char *n = NULL; int r; @@ -511,10 +519,11 @@ static void link_read_settings(Link *l) { log_warning_errno(r, "Failed to read search domains for interface %s, ignoring: %m", l->name); } -int link_update_monitor(Link *l) { +int link_update(Link *l) { assert(l); link_read_settings(l); + link_load_user(l); link_allocate_scopes(l); link_add_rrs(l, false); @@ -846,3 +855,261 @@ bool link_address_relevant(LinkAddress *a, bool local_multicast) { 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_NO || + l->dnssec_mode != _DNSSEC_MODE_INVALID) + return true; + + if (l->dns_servers || + l->search_domains) + return true; + + if (!set_isempty(l->dnssec_negative_trust_anchors)) + return true; + + return false; +} + +int link_save_user(Link *l) { + _cleanup_free_ 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; + + 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); + + if (l->dns_servers) { + DnsServer *server; + + fputs("SERVERS=", f); + LIST_FOREACH(servers, server, l->dns_servers) { + + if (server != l->dns_servers) + fputc(' ', f); + + v = dns_server_string(server); + if (!v) { + r = -ENOMEM; + goto fail; + } + + fputs(v, f); + } + fputc('\n', f); + } + + if (l->search_domains) { + DnsSearchDomain *domain; + + 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; + Iterator i; + char *nta; + + fputs("NTAS=", f); + SET_FOREACH(nta, l->dnssec_negative_trust_anchors, i) { + + 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; + } + + return 0; + +fail: + (void) unlink(l->state_file); + + if (temp_path) + (void) unlink(temp_path); + + return log_error_errno(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, + *servers = NULL, + *domains = NULL, + *ntas = NULL; + + ResolveSupport s; + 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(l->state_file, NEWLINE, + "LLMNR", &llmnr, + "MDNS", &mdns, + "DNSSEC", &dnssec, + "SERVERS", &servers, + "DOMAINS", &domains, + "NTAS", &ntas, + NULL); + 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; + + /* 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); + + if (servers) { + const char *p = servers; + + for (;;) { + _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_debug_errno(r, "Failed to load DNS server '%s', ignoring: %m", word); + continue; + } + } + } + + if (domains) { + const char *p = domains; + + for (;;) { + _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_debug_errno(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 = ns; + ns = NULL; + } + + return 0; + +fail: + return log_error_errno(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); +} diff --git a/src/resolve/resolved-link.h b/src/resolve/resolved-link.h index f534c12824..6a2343f9f7 100644 --- a/src/resolve/resolved-link.h +++ b/src/resolve/resolved-link.h @@ -81,12 +81,15 @@ struct Link { char name[IF_NAMESIZE]; uint32_t mtu; uint8_t operstate; + + bool loaded; + char *state_file; }; int link_new(Manager *m, Link **ret, int ifindex); Link *link_free(Link *l); -int link_update_rtnl(Link *l, sd_netlink_message *m); -int link_update_monitor(Link *l); +int link_process_rtnl(Link *l, sd_netlink_message *m); +int link_update(Link *l); bool link_relevant(Link *l, int family, bool local_multicast); LinkAddress* link_find_address(Link *l, int family, const union in_addr_union *in_addr); void link_add_rrs(Link *l, bool force_remove); @@ -102,6 +105,10 @@ void link_next_dns_server(Link *l); DnssecMode link_get_dnssec_mode(Link *l); bool link_dnssec_supported(Link *l); +int link_save_user(Link *l); +int link_load_user(Link *l); +void link_remove_user(Link *l); + int link_address_new(Link *l, LinkAddress **ret, int family, const union in_addr_union *in_addr); LinkAddress *link_address_free(LinkAddress *a); int link_address_update_rtnl(LinkAddress *a, sd_netlink_message *m); diff --git a/src/resolve/resolved-manager.c b/src/resolve/resolved-manager.c index 44abacb55a..e8811fa1d8 100644 --- a/src/resolve/resolved-manager.c +++ b/src/resolve/resolved-manager.c @@ -23,6 +23,7 @@ #include "af-list.h" #include "alloc-util.h" +#include "dirent-util.h" #include "dns-domain.h" #include "fd-util.h" #include "fileio-label.h" @@ -78,11 +79,11 @@ static int manager_process_link(sd_netlink *rtnl, sd_netlink_message *mm, void * goto fail; } - r = link_update_rtnl(l, mm); + r = link_process_rtnl(l, mm); if (r < 0) goto fail; - r = link_update_monitor(l); + r = link_update(l); if (r < 0) goto fail; @@ -95,6 +96,7 @@ static int manager_process_link(sd_netlink *rtnl, sd_netlink_message *mm, void * case RTM_DELLINK: if (l) { log_debug("Removing link %i/%s", l->ifindex, l->name); + link_remove_user(l); link_free(l); } @@ -279,7 +281,7 @@ static int on_network_event(sd_event_source *s, int fd, uint32_t revents, void * sd_network_monitor_flush(m->network_monitor); HASHMAP_FOREACH(l, m->links, i) { - r = link_update_monitor(l); + r = link_update(l); if (r < 0) log_warning_errno(r, "Failed to update monitor information for %i: %m", l->ifindex); } @@ -540,6 +542,8 @@ int manager_new(Manager **ret) { (void) sd_event_add_signal(m->event, &m->sigusr1_event_source, SIGUSR1, manager_sigusr1, m); (void) sd_event_add_signal(m->event, &m->sigusr2_event_source, SIGUSR2, manager_sigusr2, m); + manager_cleanup_saved_user(m); + *ret = m; m = NULL; @@ -1269,3 +1273,58 @@ void manager_flush_caches(Manager *m) { log_info("Flushed all caches."); } + +void manager_cleanup_saved_user(Manager *m) { + _cleanup_closedir_ DIR *d = NULL; + struct dirent *de; + int r; + + assert(m); + + /* Clean up all saved per-link files in /run/systemd/resolve/netif/ that don't have a matching interface + * anymore. These files are created to persist settings pushed in by the user via the bus, so that resolved can + * be restarted without losing this data. */ + + d = opendir("/run/systemd/resolve/netif/"); + if (!d) { + if (errno == ENOENT) + return; + + log_warning_errno(errno, "Failed to open interface directory: %m"); + return; + } + + FOREACH_DIRENT_ALL(de, d, log_error_errno(errno, "Failed to read interface directory: %m")) { + _cleanup_free_ char *p = NULL; + int ifindex; + Link *l; + + if (!IN_SET(de->d_type, DT_UNKNOWN, DT_REG)) + continue; + + if (STR_IN_SET(de->d_name, ".", "..")) + continue; + + r = parse_ifindex(de->d_name, &ifindex); + if (r < 0) /* Probably some temporary file from a previous run. Delete it */ + goto rm; + + l = hashmap_get(m->links, INT_TO_PTR(ifindex)); + if (!l) /* link vanished */ + goto rm; + + if (l->is_managed) /* now managed by networkd, hence the bus settings are useless */ + goto rm; + + continue; + + rm: + p = strappend("/run/systemd/resolve/netif/", de->d_name); + if (!p) { + log_oom(); + return; + } + + (void) unlink(p); + } +} diff --git a/src/resolve/resolved-manager.h b/src/resolve/resolved-manager.h index c9e6ac9d4f..eee45c94ef 100644 --- a/src/resolve/resolved-manager.h +++ b/src/resolve/resolved-manager.h @@ -172,3 +172,5 @@ void manager_dnssec_verdict(Manager *m, DnssecVerdict verdict, const DnsResource bool manager_routable(Manager *m, int family); void manager_flush_caches(Manager *m); + +void manager_cleanup_saved_user(Manager *m); -- cgit v1.2.3-54-g00ecf