src/resolve/resolved-manager.c - systemd-stable - Rivoreo Source Code Repositories

 /*-*- 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;
 }
	/-- 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;
	}