1401 lines
39 KiB
C
1401 lines
39 KiB
C
/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
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/***
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This file is part of systemd.
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Copyright 2014 Tom Gundersen <teg@jklm.no>
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systemd is free software; you can redistribute it and/or modify it
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under the terms of the GNU Lesser General Public License as published by
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the Free Software Foundation; either version 2.1 of the License, or
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(at your option) any later version.
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systemd is distributed in the hope that it will be useful, but
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WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public License
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along with systemd; If not, see <http://www.gnu.org/licenses/>.
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***/
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#include <resolv.h>
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#include <sys/ioctl.h>
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#include <poll.h>
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#include <netinet/in.h>
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#include "netlink-util.h"
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#include "network-internal.h"
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#include "socket-util.h"
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#include "af-list.h"
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#include "utf8.h"
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#include "fileio-label.h"
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#include "ordered-set.h"
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#include "random-util.h"
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#include "hostname-util.h"
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#include "dns-domain.h"
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#include "resolved-conf.h"
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#include "resolved-bus.h"
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#include "resolved-manager.h"
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#include "resolved-llmnr.h"
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#define SEND_TIMEOUT_USEC (200 * USEC_PER_MSEC)
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static int manager_process_link(sd_netlink *rtnl, sd_netlink_message *mm, void *userdata) {
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Manager *m = userdata;
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uint16_t type;
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Link *l;
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int ifindex, r;
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assert(rtnl);
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assert(m);
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assert(mm);
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r = sd_netlink_message_get_type(mm, &type);
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if (r < 0)
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goto fail;
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r = sd_rtnl_message_link_get_ifindex(mm, &ifindex);
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if (r < 0)
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goto fail;
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l = hashmap_get(m->links, INT_TO_PTR(ifindex));
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switch (type) {
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case RTM_NEWLINK:{
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bool is_new = !l;
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if (!l) {
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r = link_new(m, &l, ifindex);
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if (r < 0)
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goto fail;
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}
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r = link_update_rtnl(l, mm);
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if (r < 0)
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goto fail;
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r = link_update_monitor(l);
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if (r < 0)
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goto fail;
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if (is_new)
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log_debug("Found new link %i/%s", ifindex, l->name);
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break;
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}
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case RTM_DELLINK:
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if (l) {
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log_debug("Removing link %i/%s", l->ifindex, l->name);
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link_free(l);
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}
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break;
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}
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return 0;
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fail:
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log_warning_errno(r, "Failed to process RTNL link message: %m");
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return 0;
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}
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static int manager_process_address(sd_netlink *rtnl, sd_netlink_message *mm, void *userdata) {
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Manager *m = userdata;
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union in_addr_union address;
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uint16_t type;
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int r, ifindex, family;
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LinkAddress *a;
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Link *l;
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assert(rtnl);
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assert(mm);
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assert(m);
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r = sd_netlink_message_get_type(mm, &type);
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if (r < 0)
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goto fail;
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r = sd_rtnl_message_addr_get_ifindex(mm, &ifindex);
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if (r < 0)
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goto fail;
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l = hashmap_get(m->links, INT_TO_PTR(ifindex));
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if (!l)
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return 0;
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r = sd_rtnl_message_addr_get_family(mm, &family);
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if (r < 0)
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goto fail;
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switch (family) {
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case AF_INET:
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r = sd_netlink_message_read_in_addr(mm, IFA_LOCAL, &address.in);
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if (r < 0) {
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r = sd_netlink_message_read_in_addr(mm, IFA_ADDRESS, &address.in);
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if (r < 0)
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goto fail;
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}
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break;
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case AF_INET6:
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r = sd_netlink_message_read_in6_addr(mm, IFA_LOCAL, &address.in6);
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if (r < 0) {
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r = sd_netlink_message_read_in6_addr(mm, IFA_ADDRESS, &address.in6);
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if (r < 0)
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goto fail;
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}
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break;
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default:
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return 0;
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}
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a = link_find_address(l, family, &address);
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switch (type) {
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case RTM_NEWADDR:
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if (!a) {
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r = link_address_new(l, &a, family, &address);
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if (r < 0)
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return r;
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}
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r = link_address_update_rtnl(a, mm);
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if (r < 0)
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return r;
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break;
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case RTM_DELADDR:
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if (a)
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link_address_free(a);
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break;
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}
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return 0;
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fail:
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log_warning_errno(r, "Failed to process RTNL address message: %m");
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return 0;
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}
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static int manager_rtnl_listen(Manager *m) {
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_cleanup_netlink_message_unref_ sd_netlink_message *req = NULL, *reply = NULL;
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sd_netlink_message *i;
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int r;
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assert(m);
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/* First, subscribe to interfaces coming and going */
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r = sd_netlink_open(&m->rtnl);
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if (r < 0)
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return r;
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r = sd_netlink_attach_event(m->rtnl, m->event, 0);
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if (r < 0)
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return r;
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r = sd_netlink_add_match(m->rtnl, RTM_NEWLINK, manager_process_link, m);
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if (r < 0)
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return r;
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r = sd_netlink_add_match(m->rtnl, RTM_DELLINK, manager_process_link, m);
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if (r < 0)
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return r;
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r = sd_netlink_add_match(m->rtnl, RTM_NEWADDR, manager_process_address, m);
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if (r < 0)
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return r;
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r = sd_netlink_add_match(m->rtnl, RTM_DELADDR, manager_process_address, m);
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if (r < 0)
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return r;
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/* Then, enumerate all links */
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r = sd_rtnl_message_new_link(m->rtnl, &req, RTM_GETLINK, 0);
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if (r < 0)
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return r;
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r = sd_netlink_message_request_dump(req, true);
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if (r < 0)
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return r;
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r = sd_netlink_call(m->rtnl, req, 0, &reply);
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if (r < 0)
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return r;
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for (i = reply; i; i = sd_netlink_message_next(i)) {
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r = manager_process_link(m->rtnl, i, m);
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if (r < 0)
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return r;
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}
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req = sd_netlink_message_unref(req);
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reply = sd_netlink_message_unref(reply);
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/* Finally, enumerate all addresses, too */
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r = sd_rtnl_message_new_addr(m->rtnl, &req, RTM_GETADDR, 0, AF_UNSPEC);
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if (r < 0)
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return r;
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r = sd_netlink_message_request_dump(req, true);
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if (r < 0)
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return r;
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r = sd_netlink_call(m->rtnl, req, 0, &reply);
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if (r < 0)
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return r;
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for (i = reply; i; i = sd_netlink_message_next(i)) {
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r = manager_process_address(m->rtnl, i, m);
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if (r < 0)
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return r;
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}
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return r;
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}
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static int on_network_event(sd_event_source *s, int fd, uint32_t revents, void *userdata) {
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Manager *m = userdata;
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Iterator i;
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Link *l;
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int r;
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assert(m);
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sd_network_monitor_flush(m->network_monitor);
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HASHMAP_FOREACH(l, m->links, i) {
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r = link_update_monitor(l);
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if (r < 0)
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log_warning_errno(r, "Failed to update monitor information for %i: %m", l->ifindex);
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}
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r = manager_write_resolv_conf(m);
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if (r < 0)
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log_warning_errno(r, "Could not update resolv.conf: %m");
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return 0;
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}
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static int manager_network_monitor_listen(Manager *m) {
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int r, fd, events;
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assert(m);
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r = sd_network_monitor_new(&m->network_monitor, NULL);
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if (r < 0)
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return r;
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fd = sd_network_monitor_get_fd(m->network_monitor);
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if (fd < 0)
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return fd;
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events = sd_network_monitor_get_events(m->network_monitor);
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if (events < 0)
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return events;
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r = sd_event_add_io(m->event, &m->network_event_source, fd, events, &on_network_event, m);
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if (r < 0)
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return r;
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return 0;
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}
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static int determine_hostname(char **ret) {
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_cleanup_free_ char *h = NULL, *n = NULL;
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int r;
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assert(ret);
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h = gethostname_malloc();
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if (!h)
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return log_oom();
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if (!utf8_is_valid(h)) {
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log_error("System hostname is not UTF-8 clean.");
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return -EINVAL;
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}
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r = dns_name_normalize(h, &n);
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if (r < 0) {
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log_error("System hostname '%s' cannot be normalized.", h);
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return r;
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}
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*ret = n;
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n = NULL;
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return 0;
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}
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static int on_hostname_change(sd_event_source *es, int fd, uint32_t revents, void *userdata) {
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_cleanup_free_ char *h = NULL;
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Manager *m = userdata;
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int r;
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assert(m);
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r = determine_hostname(&h);
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if (r < 0)
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return 0; /* ignore invalid hostnames */
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if (streq(h, m->hostname))
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return 0;
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log_info("System hostname changed to '%s'.", h);
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free(m->hostname);
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m->hostname = h;
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h = NULL;
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manager_refresh_rrs(m);
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return 0;
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}
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static int manager_watch_hostname(Manager *m) {
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int r;
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assert(m);
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m->hostname_fd = open("/proc/sys/kernel/hostname", O_RDONLY|O_CLOEXEC|O_NDELAY|O_NOCTTY);
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if (m->hostname_fd < 0) {
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log_warning_errno(errno, "Failed to watch hostname: %m");
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return 0;
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}
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r = sd_event_add_io(m->event, &m->hostname_event_source, m->hostname_fd, 0, on_hostname_change, m);
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if (r < 0) {
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if (r == -EPERM)
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/* kernels prior to 3.2 don't support polling this file. Ignore the failure. */
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m->hostname_fd = safe_close(m->hostname_fd);
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else
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return log_error_errno(r, "Failed to add hostname event source: %m");
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}
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r = determine_hostname(&m->hostname);
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if (r < 0) {
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log_info("Defaulting to hostname 'linux'.");
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m->hostname = strdup("linux");
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if (!m->hostname)
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return log_oom();
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} else
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log_info("Using system hostname '%s'.", m->hostname);
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return 0;
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}
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int manager_new(Manager **ret) {
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_cleanup_(manager_freep) Manager *m = NULL;
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int r;
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assert(ret);
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m = new0(Manager, 1);
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if (!m)
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return -ENOMEM;
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m->dns_ipv4_fd = m->dns_ipv6_fd = -1;
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m->llmnr_ipv4_udp_fd = m->llmnr_ipv6_udp_fd = -1;
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m->llmnr_ipv4_tcp_fd = m->llmnr_ipv6_tcp_fd = -1;
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m->hostname_fd = -1;
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m->llmnr_support = SUPPORT_YES;
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m->read_resolv_conf = true;
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r = manager_parse_dns_server(m, DNS_SERVER_FALLBACK, DNS_SERVERS);
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if (r < 0)
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return r;
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r = sd_event_default(&m->event);
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if (r < 0)
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return r;
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sd_event_add_signal(m->event, NULL, SIGTERM, NULL, NULL);
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sd_event_add_signal(m->event, NULL, SIGINT, NULL, NULL);
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sd_event_set_watchdog(m->event, true);
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r = manager_watch_hostname(m);
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if (r < 0)
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return r;
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r = dns_scope_new(m, &m->unicast_scope, NULL, DNS_PROTOCOL_DNS, AF_UNSPEC);
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if (r < 0)
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return r;
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r = manager_network_monitor_listen(m);
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if (r < 0)
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return r;
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r = manager_rtnl_listen(m);
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if (r < 0)
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return r;
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r = manager_connect_bus(m);
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if (r < 0)
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return r;
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*ret = m;
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m = NULL;
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return 0;
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}
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int manager_start(Manager *m) {
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int r;
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assert(m);
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r = manager_llmnr_start(m);
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if (r < 0)
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return r;
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return 0;
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}
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Manager *manager_free(Manager *m) {
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Link *l;
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if (!m)
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return NULL;
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|
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while ((l = hashmap_first(m->links)))
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link_free(l);
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|
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while (m->dns_queries)
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dns_query_free(m->dns_queries);
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manager_flush_dns_servers(m, DNS_SERVER_SYSTEM);
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manager_flush_dns_servers(m, DNS_SERVER_FALLBACK);
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dns_scope_free(m->unicast_scope);
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hashmap_free(m->links);
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hashmap_free(m->dns_transactions);
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sd_event_source_unref(m->network_event_source);
|
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sd_network_monitor_unref(m->network_monitor);
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|
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sd_event_source_unref(m->dns_ipv4_event_source);
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sd_event_source_unref(m->dns_ipv6_event_source);
|
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safe_close(m->dns_ipv4_fd);
|
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safe_close(m->dns_ipv6_fd);
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|
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manager_llmnr_stop(m);
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|
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sd_bus_slot_unref(m->prepare_for_sleep_slot);
|
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sd_event_source_unref(m->bus_retry_event_source);
|
|
sd_bus_unref(m->bus);
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|
|
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sd_event_unref(m->event);
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|
|
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dns_resource_key_unref(m->host_ipv4_key);
|
|
dns_resource_key_unref(m->host_ipv6_key);
|
|
|
|
safe_close(m->hostname_fd);
|
|
sd_event_source_unref(m->hostname_event_source);
|
|
free(m->hostname);
|
|
|
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free(m);
|
|
|
|
return NULL;
|
|
}
|
|
|
|
int manager_read_resolv_conf(Manager *m) {
|
|
_cleanup_fclose_ FILE *f = NULL;
|
|
struct stat st, own;
|
|
char line[LINE_MAX];
|
|
DnsServer *s, *nx;
|
|
usec_t t;
|
|
int r;
|
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|
|
assert(m);
|
|
|
|
/* Reads the system /etc/resolv.conf, if it exists and is not
|
|
* symlinked to our own resolv.conf instance */
|
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|
|
if (!m->read_resolv_conf)
|
|
return 0;
|
|
|
|
r = stat("/etc/resolv.conf", &st);
|
|
if (r < 0) {
|
|
if (errno != ENOENT)
|
|
log_warning_errno(errno, "Failed to open /etc/resolv.conf: %m");
|
|
r = -errno;
|
|
goto clear;
|
|
}
|
|
|
|
/* Have we already seen the file? */
|
|
t = timespec_load(&st.st_mtim);
|
|
if (t == m->resolv_conf_mtime)
|
|
return 0;
|
|
|
|
m->resolv_conf_mtime = t;
|
|
|
|
/* Is it symlinked to our own file? */
|
|
if (stat("/run/systemd/resolve/resolv.conf", &own) >= 0 &&
|
|
st.st_dev == own.st_dev &&
|
|
st.st_ino == own.st_ino) {
|
|
r = 0;
|
|
goto clear;
|
|
}
|
|
|
|
f = fopen("/etc/resolv.conf", "re");
|
|
if (!f) {
|
|
if (errno != ENOENT)
|
|
log_warning_errno(errno, "Failed to open /etc/resolv.conf: %m");
|
|
r = -errno;
|
|
goto clear;
|
|
}
|
|
|
|
if (fstat(fileno(f), &st) < 0) {
|
|
log_error_errno(errno, "Failed to stat open file: %m");
|
|
r = -errno;
|
|
goto clear;
|
|
}
|
|
|
|
LIST_FOREACH(servers, s, m->dns_servers)
|
|
s->marked = true;
|
|
|
|
FOREACH_LINE(line, f, r = -errno; goto clear) {
|
|
union in_addr_union address;
|
|
int family;
|
|
char *l;
|
|
const char *a;
|
|
|
|
truncate_nl(line);
|
|
|
|
l = strstrip(line);
|
|
if (*l == '#' || *l == ';')
|
|
continue;
|
|
|
|
a = first_word(l, "nameserver");
|
|
if (!a)
|
|
continue;
|
|
|
|
r = in_addr_from_string_auto(a, &family, &address);
|
|
if (r < 0) {
|
|
log_warning("Failed to parse name server %s.", a);
|
|
continue;
|
|
}
|
|
|
|
LIST_FOREACH(servers, s, m->dns_servers)
|
|
if (s->family == family && in_addr_equal(family, &s->address, &address) > 0)
|
|
break;
|
|
|
|
if (s)
|
|
s->marked = false;
|
|
else {
|
|
r = dns_server_new(m, NULL, DNS_SERVER_SYSTEM, NULL, family, &address);
|
|
if (r < 0)
|
|
goto clear;
|
|
}
|
|
}
|
|
|
|
LIST_FOREACH_SAFE(servers, s, nx, m->dns_servers)
|
|
if (s->marked)
|
|
dns_server_free(s);
|
|
|
|
/* Whenever /etc/resolv.conf changes, start using the first
|
|
* DNS server of it. This is useful to deal with broken
|
|
* network managing implementations (like NetworkManager),
|
|
* that when connecting to a VPN place both the VPN DNS
|
|
* servers and the local ones in /etc/resolv.conf. Without
|
|
* resetting the DNS server to use back to the first entry we
|
|
* will continue to use the local one thus being unable to
|
|
* resolve VPN domains. */
|
|
manager_set_dns_server(m, m->dns_servers);
|
|
|
|
return 0;
|
|
|
|
clear:
|
|
while (m->dns_servers)
|
|
dns_server_free(m->dns_servers);
|
|
|
|
return r;
|
|
}
|
|
|
|
static void write_resolv_conf_server(DnsServer *s, FILE *f, unsigned *count) {
|
|
_cleanup_free_ char *t = NULL;
|
|
int r;
|
|
|
|
assert(s);
|
|
assert(f);
|
|
assert(count);
|
|
|
|
r = in_addr_to_string(s->family, &s->address, &t);
|
|
if (r < 0) {
|
|
log_warning_errno(r, "Invalid DNS address. Ignoring: %m");
|
|
return;
|
|
}
|
|
|
|
if (*count == MAXNS)
|
|
fputs("# Too many DNS servers configured, the following entries may be ignored.\n", f);
|
|
|
|
fprintf(f, "nameserver %s\n", t);
|
|
(*count) ++;
|
|
}
|
|
|
|
static void write_resolv_conf_search(
|
|
const char *domain, FILE *f,
|
|
unsigned *count,
|
|
unsigned *length) {
|
|
|
|
assert(domain);
|
|
assert(f);
|
|
assert(length);
|
|
|
|
if (*count >= MAXDNSRCH ||
|
|
*length + strlen(domain) > 256) {
|
|
if (*count == MAXDNSRCH)
|
|
fputs(" # Too many search domains configured, remaining ones ignored.", f);
|
|
if (*length <= 256)
|
|
fputs(" # Total length of all search domains is too long, remaining ones ignored.", f);
|
|
|
|
return;
|
|
}
|
|
|
|
fprintf(f, " %s", domain);
|
|
|
|
(*length) += strlen(domain);
|
|
(*count) ++;
|
|
}
|
|
|
|
static int write_resolv_conf_contents(FILE *f, OrderedSet *dns, OrderedSet *domains) {
|
|
Iterator i;
|
|
|
|
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);
|
|
|
|
if (ordered_set_isempty(dns))
|
|
fputs("# No DNS servers known.\n", f);
|
|
else {
|
|
DnsServer *s;
|
|
unsigned count = 0;
|
|
|
|
ORDERED_SET_FOREACH(s, dns, i)
|
|
write_resolv_conf_server(s, f, &count);
|
|
}
|
|
|
|
if (!ordered_set_isempty(domains)) {
|
|
unsigned length = 0, count = 0;
|
|
char *domain;
|
|
|
|
fputs("search", f);
|
|
ORDERED_SET_FOREACH(domain, domains, i)
|
|
write_resolv_conf_search(domain, f, &count, &length);
|
|
fputs("\n", f);
|
|
}
|
|
|
|
return fflush_and_check(f);
|
|
}
|
|
|
|
int manager_write_resolv_conf(Manager *m) {
|
|
static const char path[] = "/run/systemd/resolve/resolv.conf";
|
|
_cleanup_free_ char *temp_path = NULL;
|
|
_cleanup_fclose_ FILE *f = NULL;
|
|
_cleanup_ordered_set_free_ OrderedSet *dns = NULL, *domains = NULL;
|
|
DnsServer *s;
|
|
Iterator i;
|
|
Link *l;
|
|
int r;
|
|
|
|
assert(m);
|
|
|
|
/* Read the system /etc/resolv.conf first */
|
|
manager_read_resolv_conf(m);
|
|
|
|
/* Add the full list to a set, to filter out duplicates */
|
|
dns = ordered_set_new(&dns_server_hash_ops);
|
|
if (!dns)
|
|
return -ENOMEM;
|
|
|
|
domains = ordered_set_new(&dns_name_hash_ops);
|
|
if (!domains)
|
|
return -ENOMEM;
|
|
|
|
/* First add the system-wide servers */
|
|
LIST_FOREACH(servers, s, m->dns_servers) {
|
|
r = ordered_set_put(dns, s);
|
|
if (r == -EEXIST)
|
|
continue;
|
|
if (r < 0)
|
|
return r;
|
|
}
|
|
|
|
/* Then, add the per-link servers and domains */
|
|
HASHMAP_FOREACH(l, m->links, i) {
|
|
char **domain;
|
|
|
|
LIST_FOREACH(servers, s, l->dns_servers) {
|
|
r = ordered_set_put(dns, s);
|
|
if (r == -EEXIST)
|
|
continue;
|
|
if (r < 0)
|
|
return r;
|
|
}
|
|
|
|
if (!l->unicast_scope)
|
|
continue;
|
|
|
|
STRV_FOREACH(domain, l->unicast_scope->domains) {
|
|
r = ordered_set_put(domains, *domain);
|
|
if (r == -EEXIST)
|
|
continue;
|
|
if (r < 0)
|
|
return r;
|
|
}
|
|
}
|
|
|
|
/* If we found nothing, add the fallback servers */
|
|
if (ordered_set_isempty(dns)) {
|
|
LIST_FOREACH(servers, s, m->fallback_dns_servers) {
|
|
r = ordered_set_put(dns, s);
|
|
if (r == -EEXIST)
|
|
continue;
|
|
if (r < 0)
|
|
return r;
|
|
}
|
|
}
|
|
|
|
r = fopen_temporary_label(path, path, &f, &temp_path);
|
|
if (r < 0)
|
|
return r;
|
|
|
|
fchmod(fileno(f), 0644);
|
|
|
|
r = write_resolv_conf_contents(f, dns, domains);
|
|
if (r < 0)
|
|
goto fail;
|
|
|
|
if (rename(temp_path, path) < 0) {
|
|
r = -errno;
|
|
goto fail;
|
|
}
|
|
|
|
return 0;
|
|
|
|
fail:
|
|
(void) unlink(path);
|
|
(void) unlink(temp_path);
|
|
return r;
|
|
}
|
|
|
|
int manager_recv(Manager *m, int fd, DnsProtocol protocol, DnsPacket **ret) {
|
|
_cleanup_(dns_packet_unrefp) DnsPacket *p = NULL;
|
|
union {
|
|
struct cmsghdr header; /* For alignment */
|
|
uint8_t buffer[CMSG_SPACE(MAXSIZE(struct in_pktinfo, struct in6_pktinfo))
|
|
+ CMSG_SPACE(int) /* ttl/hoplimit */
|
|
+ EXTRA_CMSG_SPACE /* kernel appears to require extra buffer space */];
|
|
} control;
|
|
union sockaddr_union sa;
|
|
struct msghdr mh = {};
|
|
struct cmsghdr *cmsg;
|
|
struct iovec iov;
|
|
int ms = 0, r;
|
|
ssize_t l;
|
|
|
|
assert(m);
|
|
assert(fd >= 0);
|
|
assert(ret);
|
|
|
|
r = ioctl(fd, FIONREAD, &ms);
|
|
if (r < 0)
|
|
return -errno;
|
|
if (ms < 0)
|
|
return -EIO;
|
|
|
|
r = dns_packet_new(&p, protocol, ms);
|
|
if (r < 0)
|
|
return r;
|
|
|
|
iov.iov_base = DNS_PACKET_DATA(p);
|
|
iov.iov_len = p->allocated;
|
|
|
|
mh.msg_name = &sa.sa;
|
|
mh.msg_namelen = sizeof(sa);
|
|
mh.msg_iov = &iov;
|
|
mh.msg_iovlen = 1;
|
|
mh.msg_control = &control;
|
|
mh.msg_controllen = sizeof(control);
|
|
|
|
l = recvmsg(fd, &mh, 0);
|
|
if (l < 0) {
|
|
if (errno == EAGAIN || errno == EINTR)
|
|
return 0;
|
|
|
|
return -errno;
|
|
}
|
|
|
|
if (l <= 0)
|
|
return -EIO;
|
|
|
|
assert(!(mh.msg_flags & MSG_CTRUNC));
|
|
assert(!(mh.msg_flags & MSG_TRUNC));
|
|
|
|
p->size = (size_t) l;
|
|
|
|
p->family = sa.sa.sa_family;
|
|
p->ipproto = IPPROTO_UDP;
|
|
if (p->family == AF_INET) {
|
|
p->sender.in = sa.in.sin_addr;
|
|
p->sender_port = be16toh(sa.in.sin_port);
|
|
} else if (p->family == AF_INET6) {
|
|
p->sender.in6 = sa.in6.sin6_addr;
|
|
p->sender_port = be16toh(sa.in6.sin6_port);
|
|
p->ifindex = sa.in6.sin6_scope_id;
|
|
} else
|
|
return -EAFNOSUPPORT;
|
|
|
|
CMSG_FOREACH(cmsg, &mh) {
|
|
|
|
if (cmsg->cmsg_level == IPPROTO_IPV6) {
|
|
assert(p->family == AF_INET6);
|
|
|
|
switch (cmsg->cmsg_type) {
|
|
|
|
case IPV6_PKTINFO: {
|
|
struct in6_pktinfo *i = (struct in6_pktinfo*) CMSG_DATA(cmsg);
|
|
|
|
if (p->ifindex <= 0)
|
|
p->ifindex = i->ipi6_ifindex;
|
|
|
|
p->destination.in6 = i->ipi6_addr;
|
|
break;
|
|
}
|
|
|
|
case IPV6_HOPLIMIT:
|
|
p->ttl = *(int *) CMSG_DATA(cmsg);
|
|
break;
|
|
|
|
}
|
|
} else if (cmsg->cmsg_level == IPPROTO_IP) {
|
|
assert(p->family == AF_INET);
|
|
|
|
switch (cmsg->cmsg_type) {
|
|
|
|
case IP_PKTINFO: {
|
|
struct in_pktinfo *i = (struct in_pktinfo*) CMSG_DATA(cmsg);
|
|
|
|
if (p->ifindex <= 0)
|
|
p->ifindex = i->ipi_ifindex;
|
|
|
|
p->destination.in = i->ipi_addr;
|
|
break;
|
|
}
|
|
|
|
case IP_TTL:
|
|
p->ttl = *(int *) CMSG_DATA(cmsg);
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
/* The Linux kernel sets the interface index to the loopback
|
|
* device if the packet came from the local host since it
|
|
* avoids the routing table in such a case. Let's unset the
|
|
* interface index in such a case. */
|
|
if (p->ifindex == LOOPBACK_IFINDEX)
|
|
p->ifindex = 0;
|
|
|
|
/* If we don't know the interface index still, we look for the
|
|
* first local interface with a matching address. Yuck! */
|
|
if (p->ifindex <= 0)
|
|
p->ifindex = manager_find_ifindex(m, p->family, &p->destination);
|
|
|
|
*ret = p;
|
|
p = NULL;
|
|
|
|
return 1;
|
|
}
|
|
|
|
static int on_dns_packet(sd_event_source *s, int fd, uint32_t revents, void *userdata) {
|
|
_cleanup_(dns_packet_unrefp) DnsPacket *p = NULL;
|
|
DnsTransaction *t = NULL;
|
|
Manager *m = userdata;
|
|
int r;
|
|
|
|
r = manager_recv(m, fd, DNS_PROTOCOL_DNS, &p);
|
|
if (r <= 0)
|
|
return r;
|
|
|
|
if (dns_packet_validate_reply(p) > 0) {
|
|
t = hashmap_get(m->dns_transactions, UINT_TO_PTR(DNS_PACKET_ID(p)));
|
|
if (!t)
|
|
return 0;
|
|
|
|
dns_transaction_process_reply(t, p);
|
|
|
|
} else
|
|
log_debug("Invalid DNS packet.");
|
|
|
|
return 0;
|
|
}
|
|
|
|
int manager_dns_ipv4_fd(Manager *m) {
|
|
const int one = 1;
|
|
int r;
|
|
|
|
assert(m);
|
|
|
|
if (m->dns_ipv4_fd >= 0)
|
|
return m->dns_ipv4_fd;
|
|
|
|
m->dns_ipv4_fd = socket(AF_INET, SOCK_DGRAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0);
|
|
if (m->dns_ipv4_fd < 0)
|
|
return -errno;
|
|
|
|
r = setsockopt(m->dns_ipv4_fd, IPPROTO_IP, IP_PKTINFO, &one, sizeof(one));
|
|
if (r < 0) {
|
|
r = -errno;
|
|
goto fail;
|
|
}
|
|
|
|
r = sd_event_add_io(m->event, &m->dns_ipv4_event_source, m->dns_ipv4_fd, EPOLLIN, on_dns_packet, m);
|
|
if (r < 0)
|
|
goto fail;
|
|
|
|
return m->dns_ipv4_fd;
|
|
|
|
fail:
|
|
m->dns_ipv4_fd = safe_close(m->dns_ipv4_fd);
|
|
return r;
|
|
}
|
|
|
|
int manager_dns_ipv6_fd(Manager *m) {
|
|
const int one = 1;
|
|
int r;
|
|
|
|
assert(m);
|
|
|
|
if (m->dns_ipv6_fd >= 0)
|
|
return m->dns_ipv6_fd;
|
|
|
|
m->dns_ipv6_fd = socket(AF_INET6, SOCK_DGRAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0);
|
|
if (m->dns_ipv6_fd < 0)
|
|
return -errno;
|
|
|
|
r = setsockopt(m->dns_ipv6_fd, IPPROTO_IPV6, IPV6_RECVPKTINFO, &one, sizeof(one));
|
|
if (r < 0) {
|
|
r = -errno;
|
|
goto fail;
|
|
}
|
|
|
|
r = sd_event_add_io(m->event, &m->dns_ipv6_event_source, m->dns_ipv6_fd, EPOLLIN, on_dns_packet, m);
|
|
if (r < 0)
|
|
goto fail;
|
|
|
|
return m->dns_ipv6_fd;
|
|
|
|
fail:
|
|
m->dns_ipv6_fd = safe_close(m->dns_ipv6_fd);
|
|
return r;
|
|
}
|
|
|
|
static int sendmsg_loop(int fd, struct msghdr *mh, int flags) {
|
|
int r;
|
|
|
|
assert(fd >= 0);
|
|
assert(mh);
|
|
|
|
for (;;) {
|
|
if (sendmsg(fd, mh, flags) >= 0)
|
|
return 0;
|
|
|
|
if (errno == EINTR)
|
|
continue;
|
|
|
|
if (errno != EAGAIN)
|
|
return -errno;
|
|
|
|
r = fd_wait_for_event(fd, POLLOUT, SEND_TIMEOUT_USEC);
|
|
if (r < 0)
|
|
return r;
|
|
if (r == 0)
|
|
return -ETIMEDOUT;
|
|
}
|
|
}
|
|
|
|
static int manager_ipv4_send(Manager *m, int fd, int ifindex, const struct in_addr *addr, uint16_t port, DnsPacket *p) {
|
|
union sockaddr_union sa = {
|
|
.in.sin_family = AF_INET,
|
|
};
|
|
union {
|
|
struct cmsghdr header; /* For alignment */
|
|
uint8_t buffer[CMSG_SPACE(sizeof(struct in_pktinfo))];
|
|
} control;
|
|
struct msghdr mh = {};
|
|
struct iovec iov;
|
|
|
|
assert(m);
|
|
assert(fd >= 0);
|
|
assert(addr);
|
|
assert(port > 0);
|
|
assert(p);
|
|
|
|
iov.iov_base = DNS_PACKET_DATA(p);
|
|
iov.iov_len = p->size;
|
|
|
|
sa.in.sin_addr = *addr;
|
|
sa.in.sin_port = htobe16(port),
|
|
|
|
mh.msg_iov = &iov;
|
|
mh.msg_iovlen = 1;
|
|
mh.msg_name = &sa.sa;
|
|
mh.msg_namelen = sizeof(sa.in);
|
|
|
|
if (ifindex > 0) {
|
|
struct cmsghdr *cmsg;
|
|
struct in_pktinfo *pi;
|
|
|
|
zero(control);
|
|
|
|
mh.msg_control = &control;
|
|
mh.msg_controllen = CMSG_LEN(sizeof(struct in_pktinfo));
|
|
|
|
cmsg = CMSG_FIRSTHDR(&mh);
|
|
cmsg->cmsg_len = mh.msg_controllen;
|
|
cmsg->cmsg_level = IPPROTO_IP;
|
|
cmsg->cmsg_type = IP_PKTINFO;
|
|
|
|
pi = (struct in_pktinfo*) CMSG_DATA(cmsg);
|
|
pi->ipi_ifindex = ifindex;
|
|
}
|
|
|
|
return sendmsg_loop(fd, &mh, 0);
|
|
}
|
|
|
|
static int manager_ipv6_send(Manager *m, int fd, int ifindex, const struct in6_addr *addr, uint16_t port, DnsPacket *p) {
|
|
union sockaddr_union sa = {
|
|
.in6.sin6_family = AF_INET6,
|
|
};
|
|
union {
|
|
struct cmsghdr header; /* For alignment */
|
|
uint8_t buffer[CMSG_SPACE(sizeof(struct in6_pktinfo))];
|
|
} control;
|
|
struct msghdr mh = {};
|
|
struct iovec iov;
|
|
|
|
assert(m);
|
|
assert(fd >= 0);
|
|
assert(addr);
|
|
assert(port > 0);
|
|
assert(p);
|
|
|
|
iov.iov_base = DNS_PACKET_DATA(p);
|
|
iov.iov_len = p->size;
|
|
|
|
sa.in6.sin6_addr = *addr;
|
|
sa.in6.sin6_port = htobe16(port),
|
|
sa.in6.sin6_scope_id = ifindex;
|
|
|
|
mh.msg_iov = &iov;
|
|
mh.msg_iovlen = 1;
|
|
mh.msg_name = &sa.sa;
|
|
mh.msg_namelen = sizeof(sa.in6);
|
|
|
|
if (ifindex > 0) {
|
|
struct cmsghdr *cmsg;
|
|
struct in6_pktinfo *pi;
|
|
|
|
zero(control);
|
|
|
|
mh.msg_control = &control;
|
|
mh.msg_controllen = CMSG_LEN(sizeof(struct in6_pktinfo));
|
|
|
|
cmsg = CMSG_FIRSTHDR(&mh);
|
|
cmsg->cmsg_len = mh.msg_controllen;
|
|
cmsg->cmsg_level = IPPROTO_IPV6;
|
|
cmsg->cmsg_type = IPV6_PKTINFO;
|
|
|
|
pi = (struct in6_pktinfo*) CMSG_DATA(cmsg);
|
|
pi->ipi6_ifindex = ifindex;
|
|
}
|
|
|
|
return sendmsg_loop(fd, &mh, 0);
|
|
}
|
|
|
|
int manager_send(Manager *m, int fd, int ifindex, int family, const union in_addr_union *addr, uint16_t port, DnsPacket *p) {
|
|
assert(m);
|
|
assert(fd >= 0);
|
|
assert(addr);
|
|
assert(port > 0);
|
|
assert(p);
|
|
|
|
log_debug("Sending %s packet with id %u on interface %i/%s", DNS_PACKET_QR(p) ? "response" : "query", DNS_PACKET_ID(p), ifindex, af_to_name(family));
|
|
|
|
if (family == AF_INET)
|
|
return manager_ipv4_send(m, fd, ifindex, &addr->in, port, p);
|
|
else if (family == AF_INET6)
|
|
return manager_ipv6_send(m, fd, ifindex, &addr->in6, port, p);
|
|
|
|
return -EAFNOSUPPORT;
|
|
}
|
|
|
|
DnsServer* manager_find_dns_server(Manager *m, int family, const union in_addr_union *in_addr) {
|
|
DnsServer *s;
|
|
|
|
assert(m);
|
|
assert(in_addr);
|
|
|
|
LIST_FOREACH(servers, s, m->dns_servers)
|
|
if (s->family == family && in_addr_equal(family, &s->address, in_addr) > 0)
|
|
return s;
|
|
|
|
LIST_FOREACH(servers, s, m->fallback_dns_servers)
|
|
if (s->family == family && in_addr_equal(family, &s->address, in_addr) > 0)
|
|
return s;
|
|
|
|
return NULL;
|
|
}
|
|
|
|
DnsServer *manager_set_dns_server(Manager *m, DnsServer *s) {
|
|
assert(m);
|
|
|
|
if (m->current_dns_server == s)
|
|
return s;
|
|
|
|
if (s) {
|
|
_cleanup_free_ char *ip = NULL;
|
|
|
|
in_addr_to_string(s->family, &s->address, &ip);
|
|
log_info("Switching to system DNS server %s.", strna(ip));
|
|
}
|
|
|
|
m->current_dns_server = s;
|
|
|
|
if (m->unicast_scope)
|
|
dns_cache_flush(&m->unicast_scope->cache);
|
|
|
|
return s;
|
|
}
|
|
|
|
DnsServer *manager_get_dns_server(Manager *m) {
|
|
Link *l;
|
|
assert(m);
|
|
|
|
/* Try to read updates resolv.conf */
|
|
manager_read_resolv_conf(m);
|
|
|
|
if (!m->current_dns_server)
|
|
manager_set_dns_server(m, m->dns_servers);
|
|
|
|
if (!m->current_dns_server) {
|
|
bool found = false;
|
|
Iterator i;
|
|
|
|
/* No DNS servers configured, let's see if there are
|
|
* any on any links. If not, we use the fallback
|
|
* servers */
|
|
|
|
HASHMAP_FOREACH(l, m->links, i)
|
|
if (l->dns_servers) {
|
|
found = true;
|
|
break;
|
|
}
|
|
|
|
if (!found)
|
|
manager_set_dns_server(m, m->fallback_dns_servers);
|
|
}
|
|
|
|
return m->current_dns_server;
|
|
}
|
|
|
|
void manager_next_dns_server(Manager *m) {
|
|
assert(m);
|
|
|
|
/* If there's currently no DNS server set, then the next
|
|
* manager_get_dns_server() will find one */
|
|
if (!m->current_dns_server)
|
|
return;
|
|
|
|
/* Change to the next one */
|
|
if (m->current_dns_server->servers_next) {
|
|
manager_set_dns_server(m, m->current_dns_server->servers_next);
|
|
return;
|
|
}
|
|
|
|
/* If there was no next one, then start from the beginning of
|
|
* the list */
|
|
if (m->current_dns_server->type == DNS_SERVER_FALLBACK)
|
|
manager_set_dns_server(m, m->fallback_dns_servers);
|
|
else
|
|
manager_set_dns_server(m, m->dns_servers);
|
|
}
|
|
|
|
uint32_t manager_find_mtu(Manager *m) {
|
|
uint32_t mtu = 0;
|
|
Link *l;
|
|
Iterator i;
|
|
|
|
/* If we don't know on which link a DNS packet would be
|
|
* delivered, let's find the largest MTU that works on all
|
|
* interfaces we know of */
|
|
|
|
HASHMAP_FOREACH(l, m->links, i) {
|
|
if (l->mtu <= 0)
|
|
continue;
|
|
|
|
if (mtu <= 0 || l->mtu < mtu)
|
|
mtu = l->mtu;
|
|
}
|
|
|
|
return mtu;
|
|
}
|
|
|
|
int manager_find_ifindex(Manager *m, int family, const union in_addr_union *in_addr) {
|
|
LinkAddress *a;
|
|
|
|
assert(m);
|
|
|
|
a = manager_find_link_address(m, family, in_addr);
|
|
if (a)
|
|
return a->link->ifindex;
|
|
|
|
return 0;
|
|
}
|
|
|
|
void manager_refresh_rrs(Manager *m) {
|
|
Iterator i;
|
|
Link *l;
|
|
|
|
assert(m);
|
|
|
|
m->host_ipv4_key = dns_resource_key_unref(m->host_ipv4_key);
|
|
m->host_ipv6_key = dns_resource_key_unref(m->host_ipv6_key);
|
|
|
|
HASHMAP_FOREACH(l, m->links, i) {
|
|
link_add_rrs(l, true);
|
|
link_add_rrs(l, false);
|
|
}
|
|
}
|
|
|
|
int manager_next_hostname(Manager *m) {
|
|
const char *p;
|
|
uint64_t u, a;
|
|
char *h;
|
|
|
|
assert(m);
|
|
|
|
p = strchr(m->hostname, 0);
|
|
assert(p);
|
|
|
|
while (p > m->hostname) {
|
|
if (!strchr("0123456789", p[-1]))
|
|
break;
|
|
|
|
p--;
|
|
}
|
|
|
|
if (*p == 0 || safe_atou64(p, &u) < 0 || u <= 0)
|
|
u = 1;
|
|
|
|
/* Add a random number to the old value. This way we can avoid
|
|
* that two hosts pick the same hostname, win on IPv4 and lose
|
|
* on IPv6 (or vice versa), and pick the same hostname
|
|
* replacement hostname, ad infinitum. We still want the
|
|
* numbers to go up monotonically, hence we just add a random
|
|
* value 1..10 */
|
|
|
|
random_bytes(&a, sizeof(a));
|
|
u += 1 + a % 10;
|
|
|
|
if (asprintf(&h, "%.*s%" PRIu64, (int) (p - m->hostname), m->hostname, u) < 0)
|
|
return -ENOMEM;
|
|
|
|
log_info("Hostname conflict, changing published hostname from '%s' to '%s'.", m->hostname, h);
|
|
|
|
free(m->hostname);
|
|
m->hostname = h;
|
|
|
|
manager_refresh_rrs(m);
|
|
|
|
return 0;
|
|
}
|
|
|
|
LinkAddress* manager_find_link_address(Manager *m, int family, const union in_addr_union *in_addr) {
|
|
Iterator i;
|
|
Link *l;
|
|
|
|
assert(m);
|
|
|
|
HASHMAP_FOREACH(l, m->links, i) {
|
|
LinkAddress *a;
|
|
|
|
a = link_find_address(l, family, in_addr);
|
|
if (a)
|
|
return a;
|
|
}
|
|
|
|
return NULL;
|
|
}
|
|
|
|
bool manager_our_packet(Manager *m, DnsPacket *p) {
|
|
assert(m);
|
|
assert(p);
|
|
|
|
return !!manager_find_link_address(m, p->family, &p->sender);
|
|
}
|
|
|
|
DnsScope* manager_find_scope(Manager *m, DnsPacket *p) {
|
|
Link *l;
|
|
|
|
assert(m);
|
|
assert(p);
|
|
|
|
l = hashmap_get(m->links, INT_TO_PTR(p->ifindex));
|
|
if (!l)
|
|
return NULL;
|
|
|
|
if (p->protocol == DNS_PROTOCOL_LLMNR) {
|
|
if (p->family == AF_INET)
|
|
return l->llmnr_ipv4_scope;
|
|
else if (p->family == AF_INET6)
|
|
return l->llmnr_ipv6_scope;
|
|
}
|
|
|
|
return NULL;
|
|
}
|
|
|
|
void manager_verify_all(Manager *m) {
|
|
DnsScope *s;
|
|
|
|
assert(m);
|
|
|
|
LIST_FOREACH(scopes, s, m->dns_scopes)
|
|
dns_zone_verify_all(&s->zone);
|
|
}
|
|
|
|
void manager_flush_dns_servers(Manager *m, DnsServerType t) {
|
|
assert(m);
|
|
|
|
if (t == DNS_SERVER_SYSTEM)
|
|
while (m->dns_servers)
|
|
dns_server_free(m->dns_servers);
|
|
|
|
if (t == DNS_SERVER_FALLBACK)
|
|
while (m->fallback_dns_servers)
|
|
dns_server_free(m->fallback_dns_servers);
|
|
}
|
|
|
|
static const char* const support_table[_SUPPORT_MAX] = {
|
|
[SUPPORT_NO] = "no",
|
|
[SUPPORT_YES] = "yes",
|
|
[SUPPORT_RESOLVE] = "resolve",
|
|
};
|
|
DEFINE_STRING_TABLE_LOOKUP(support, Support);
|