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authorTom Gundersen <teg@jklm.no>2014-05-18 22:10:48 +0200
committerTom Gundersen <teg@jklm.no>2014-05-19 18:14:56 +0200
commit091a364c802e34a58f3260c9cb5db9b75c62215c (patch)
tree35b22463dde65c3fcaec38653fe757ae30152b15 /src/resolve/resolved-manager.c
parent7dbf94a9c4dcdf9b56384e66eb2652fb61da5063 (diff)
resolved: add daemon to manage resolv.conf
Also remove the equivalent functionality from networkd.
Diffstat (limited to 'src/resolve/resolved-manager.c')
-rw-r--r--src/resolve/resolved-manager.c320
1 files changed, 320 insertions, 0 deletions
diff --git a/src/resolve/resolved-manager.c b/src/resolve/resolved-manager.c
new file mode 100644
index 0000000000..ae173991da
--- /dev/null
+++ b/src/resolve/resolved-manager.c
@@ -0,0 +1,320 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+/***
+ This file is part of systemd.
+
+ Copyright 2014 Tom Gundersen <teg@jklm.no>
+
+ systemd is free software; you can redistribute it and/or modify it
+ under the terms of the GNU Lesser General Public License as published by
+ the Free Software Foundation; either version 2.1 of the License, or
+ (at your option) any later version.
+
+ systemd is distributed in the hope that it will be useful, but
+ WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public License
+ along with systemd; If not, see <http://www.gnu.org/licenses/>.
+ ***/
+
+#include <arpa/inet.h>
+#include <resolv.h>
+#include <linux/if.h>
+
+#include "resolved.h"
+#include "event-util.h"
+#include "network-util.h"
+#include "sd-dhcp-lease.h"
+#include "dhcp-lease-internal.h"
+#include "network-internal.h"
+#include "conf-parser.h"
+#include "mkdir.h"
+
+static int set_fallback_dns(Manager *m, const char *string) {
+ char *word, *state;
+ size_t length;
+ int r;
+
+ assert(m);
+ assert(string);
+
+ FOREACH_WORD_QUOTED(word, length, string, state) {
+ _cleanup_free_ Address *address = NULL;
+ Address *tail;
+ _cleanup_free_ char *addrstr = NULL;
+
+ address = new0(Address, 1);
+ if (!address)
+ return -ENOMEM;
+
+ addrstr = strndup(word, length);
+ if (!addrstr)
+ return -ENOMEM;
+
+ r = net_parse_inaddr(addrstr, &address->family, &address->in_addr);
+ if (r < 0) {
+ log_debug("Ignoring invalid DNS address '%s'", addrstr);
+ continue;
+ }
+
+ LIST_FIND_TAIL(addresses, m->fallback_dns, tail);
+ LIST_INSERT_AFTER(addresses, m->fallback_dns, tail, address);
+ address = NULL;
+ }
+
+ return 0;
+}
+
+int config_parse_dnsv(
+ const char *unit,
+ const char *filename,
+ unsigned line,
+ const char *section,
+ unsigned section_line,
+ const char *lvalue,
+ int ltype,
+ const char *rvalue,
+ void *data,
+ void *userdata) {
+
+ Manager *m = userdata;
+ Address *address;
+
+ assert(filename);
+ assert(lvalue);
+ assert(rvalue);
+ assert(m);
+
+ while ((address = m->fallback_dns)) {
+ LIST_REMOVE(addresses, m->fallback_dns, address);
+ free(address);
+ }
+
+ set_fallback_dns(m, rvalue);
+
+ return 0;
+}
+
+static int manager_parse_config_file(Manager *m) {
+ static const char fn[] = "/etc/systemd/resolved.conf";
+ _cleanup_fclose_ FILE *f = NULL;
+ int r;
+
+ assert(m);
+
+ f = fopen(fn, "re");
+ if (!f) {
+ if (errno == ENOENT)
+ return 0;
+
+ log_warning("Failed to open configuration file %s: %m", fn);
+ return -errno;
+ }
+
+ r = config_parse(NULL, fn, f, "Resolve\0", config_item_perf_lookup,
+ (void*) resolved_gperf_lookup, false, false, m);
+ if (r < 0)
+ log_warning("Failed to parse configuration file: %s", strerror(-r));
+
+ return r;
+}
+
+int manager_new(Manager **ret) {
+ _cleanup_manager_free_ Manager *m = NULL;
+ int r;
+
+ m = new0(Manager, 1);
+ if (!m)
+ return -ENOMEM;
+
+ r = set_fallback_dns(m, DNS_SERVERS);
+ if (r < 0)
+ return r;
+
+ r = manager_parse_config_file(m);
+ if (r < 0)
+ return r;
+
+ r = sd_event_default(&m->event);
+ if (r < 0)
+ return r;
+
+ sd_event_add_signal(m->event, NULL, SIGTERM, NULL, NULL);
+ sd_event_add_signal(m->event, NULL, SIGINT, NULL, NULL);
+
+ sd_event_set_watchdog(m->event, true);
+
+ *ret = m;
+ m = NULL;
+
+ return 0;
+}
+
+void manager_free(Manager *m) {
+ Address *address;
+
+ if (!m)
+ return;
+
+ sd_event_unref(m->event);
+
+ while ((address = m->fallback_dns)) {
+ LIST_REMOVE(addresses, m->fallback_dns, address);
+ free(address);
+ }
+
+ free(m);
+}
+
+static void append_dns(FILE *f, void *dns, unsigned char family, unsigned *count) {
+ char buf[INET6_ADDRSTRLEN];
+ const char *address;
+
+ assert(f);
+ assert(dns);
+ assert(count);
+
+ address = inet_ntop(family, dns, buf, INET6_ADDRSTRLEN);
+ if (!address) {
+ log_warning("Invalid DNS address. Ignoring.");
+ return;
+ }
+
+ if (*count == MAXNS)
+ fputs("# Too many DNS servers configured, the following entries "
+ "may be ignored\n", f);
+
+ fprintf(f, "nameserver %s\n", address);
+
+ (*count) ++;
+}
+
+int manager_update_resolv_conf(Manager *m) {
+ _cleanup_free_ char *temp_path = NULL;
+ _cleanup_fclose_ FILE *f = NULL;
+ _cleanup_free_ unsigned *indices = NULL;
+ Address *address;
+ unsigned count = 0;
+ int n, r, i;
+
+ assert(m);
+
+ r = fopen_temporary("/run/systemd/network/resolv.conf", &f, &temp_path);
+ if (r < 0)
+ return r;
+
+ fchmod(fileno(f), 0644);
+
+ fputs("# This file is managed by systemd-resolved(8). Do not edit.\n#\n"
+ "# Third party programs must not access this file directly, but\n"
+ "# only through the symlink at /etc/resolv.conf. To manage\n"
+ "# resolv.conf(5) in a different way, replace the symlink by a\n"
+ "# static file or a different symlink.\n\n", f);
+
+ n = sd_network_get_ifindices(&indices);
+ if (n < 0)
+ n = 0;
+
+ for (i = 0; i < n; i++) {
+ _cleanup_dhcp_lease_unref_ sd_dhcp_lease *lease = NULL;
+ struct in_addr *nameservers;
+ struct in6_addr *nameservers6;
+ size_t nameservers_size;
+
+ r = sd_network_dhcp_use_dns(indices[i]);
+ if (r > 0) {
+ r = sd_network_get_dhcp_lease(indices[i], &lease);
+ if (r >= 0) {
+ r = sd_dhcp_lease_get_dns(lease, &nameservers, &nameservers_size);
+ if (r >= 0) {
+ unsigned j;
+
+ for (j = 0; j < nameservers_size; j++)
+ append_dns(f, &nameservers[j], AF_INET, &count);
+ }
+ }
+ }
+
+ r = sd_network_get_dns(indices[i], &nameservers, &nameservers_size);
+ if (r >= 0) {
+ unsigned j;
+
+ for (j = 0; j < nameservers_size; j++)
+ append_dns(f, &nameservers[j], AF_INET, &count);
+
+ free(nameservers);
+ }
+
+ r = sd_network_get_dns6(indices[i], &nameservers6, &nameservers_size);
+ if (r >= 0) {
+ unsigned j;
+
+ for (j = 0; j < nameservers_size; j++)
+ append_dns(f, &nameservers6[j], AF_INET6, &count);
+
+ free(nameservers6);
+ }
+ }
+
+ LIST_FOREACH(addresses, address, m->fallback_dns)
+ append_dns(f, &address->in_addr, address->family, &count);
+
+ fflush(f);
+
+ if (ferror(f) || rename(temp_path, "/run/systemd/network/resolv.conf") < 0) {
+ r = -errno;
+ unlink("/run/systemd/network/resolv.conf");
+ unlink(temp_path);
+ return r;
+ }
+
+ return 0;
+}
+
+static int manager_network_event_handler(sd_event_source *s, int fd, uint32_t revents,
+ void *userdata) {
+ Manager *m = userdata;
+ int r;
+
+ assert(m);
+
+ r = manager_update_resolv_conf(m);
+ if (r < 0)
+ log_warning("Could not update resolv.conf: %s", strerror(-r));
+
+ sd_network_monitor_flush(m->network_monitor);
+
+ return 0;
+}
+
+int manager_network_monitor_listen(Manager *m) {
+ _cleanup_event_source_unref_ sd_event_source *event_source = NULL;
+ _cleanup_network_monitor_unref_ sd_network_monitor *monitor = NULL;
+ int r, fd, events;
+
+ r = sd_network_monitor_new(NULL, &monitor);
+ if (r < 0)
+ return r;
+
+ fd = sd_network_monitor_get_fd(monitor);
+ if (fd < 0)
+ return fd;
+
+ events = sd_network_monitor_get_events(monitor);
+ if (events < 0)
+ return events;
+
+ r = sd_event_add_io(m->event, &event_source, fd, events,
+ &manager_network_event_handler, m);
+ if (r < 0)
+ return r;
+
+ m->network_monitor = monitor;
+ m->network_event_source = event_source;
+ monitor = NULL;
+ event_source = NULL;
+
+ return 0;
+}