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authorLennart Poettering <lennart@poettering.net>2016-06-15 22:38:23 +0200
committerLennart Poettering <lennart@poettering.net>2016-06-21 13:20:48 +0200
commit943ef07ce0aacbee93c721e461c02d651ee9ef6a (patch)
tree0d8782c9ffe613704e6f95a1411e15484da8f991
parentd97c5aeab8b9c6d871cad292c17c9b9c94736e25 (diff)
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.
-rw-r--r--src/resolve/resolved-link-bus.c11
-rw-r--r--src/resolve/resolved-link.c271
-rw-r--r--src/resolve/resolved-link.h11
-rw-r--r--src/resolve/resolved-manager.c65
-rw-r--r--src/resolve/resolved-manager.h2
5 files changed, 353 insertions, 7 deletions
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);