1 /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
4 This file is part of systemd.
6 Copyright 2014 Tom Gundersen <teg@jklm.no>
8 systemd is free software; you can redistribute it and/or modify it
9 under the terms of the GNU Lesser General Public License as published by
10 the Free Software Foundation; either version 2.1 of the License, or
11 (at your option) any later version.
13 systemd is distributed in the hope that it will be useful, but
14 WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 Lesser General Public License for more details.
18 You should have received a copy of the GNU Lesser General Public License
19 along with systemd; If not, see <http://www.gnu.org/licenses/>.
23 #include <sys/ioctl.h>
25 #include <netinet/in.h>
27 #include "netlink-util.h"
28 #include "network-internal.h"
29 #include "socket-util.h"
32 #include "fileio-label.h"
33 #include "ordered-set.h"
34 #include "random-util.h"
35 #include "hostname-util.h"
37 #include "dns-domain.h"
38 #include "resolved-conf.h"
39 #include "resolved-bus.h"
40 #include "resolved-manager.h"
41 #include "resolved-llmnr.h"
43 #define SEND_TIMEOUT_USEC (200 * USEC_PER_MSEC)
45 static int manager_process_link(sd_netlink
*rtnl
, sd_netlink_message
*mm
, void *userdata
) {
46 Manager
*m
= userdata
;
55 r
= sd_netlink_message_get_type(mm
, &type
);
59 r
= sd_rtnl_message_link_get_ifindex(mm
, &ifindex
);
63 l
= hashmap_get(m
->links
, INT_TO_PTR(ifindex
));
71 r
= link_new(m
, &l
, ifindex
);
76 r
= link_update_rtnl(l
, mm
);
80 r
= link_update_monitor(l
);
85 log_debug("Found new link %i/%s", ifindex
, l
->name
);
92 log_debug("Removing link %i/%s", l
->ifindex
, l
->name
);
102 log_warning_errno(r
, "Failed to process RTNL link message: %m");
106 static int manager_process_address(sd_netlink
*rtnl
, sd_netlink_message
*mm
, void *userdata
) {
107 Manager
*m
= userdata
;
108 union in_addr_union address
;
110 int r
, ifindex
, family
;
118 r
= sd_netlink_message_get_type(mm
, &type
);
122 r
= sd_rtnl_message_addr_get_ifindex(mm
, &ifindex
);
126 l
= hashmap_get(m
->links
, INT_TO_PTR(ifindex
));
130 r
= sd_rtnl_message_addr_get_family(mm
, &family
);
137 r
= sd_netlink_message_read_in_addr(mm
, IFA_LOCAL
, &address
.in
);
139 r
= sd_netlink_message_read_in_addr(mm
, IFA_ADDRESS
, &address
.in
);
147 r
= sd_netlink_message_read_in6_addr(mm
, IFA_LOCAL
, &address
.in6
);
149 r
= sd_netlink_message_read_in6_addr(mm
, IFA_ADDRESS
, &address
.in6
);
160 a
= link_find_address(l
, family
, &address
);
167 r
= link_address_new(l
, &a
, family
, &address
);
172 r
= link_address_update_rtnl(a
, mm
);
180 link_address_free(a
);
187 log_warning_errno(r
, "Failed to process RTNL address message: %m");
191 static int manager_rtnl_listen(Manager
*m
) {
192 _cleanup_netlink_message_unref_ sd_netlink_message
*req
= NULL
, *reply
= NULL
;
193 sd_netlink_message
*i
;
198 /* First, subscribe to interfaces coming and going */
199 r
= sd_netlink_open(&m
->rtnl
);
203 r
= sd_netlink_attach_event(m
->rtnl
, m
->event
, 0);
207 r
= sd_netlink_add_match(m
->rtnl
, RTM_NEWLINK
, manager_process_link
, m
);
211 r
= sd_netlink_add_match(m
->rtnl
, RTM_DELLINK
, manager_process_link
, m
);
215 r
= sd_netlink_add_match(m
->rtnl
, RTM_NEWADDR
, manager_process_address
, m
);
219 r
= sd_netlink_add_match(m
->rtnl
, RTM_DELADDR
, manager_process_address
, m
);
223 /* Then, enumerate all links */
224 r
= sd_rtnl_message_new_link(m
->rtnl
, &req
, RTM_GETLINK
, 0);
228 r
= sd_netlink_message_request_dump(req
, true);
232 r
= sd_netlink_call(m
->rtnl
, req
, 0, &reply
);
236 for (i
= reply
; i
; i
= sd_netlink_message_next(i
)) {
237 r
= manager_process_link(m
->rtnl
, i
, m
);
242 req
= sd_netlink_message_unref(req
);
243 reply
= sd_netlink_message_unref(reply
);
245 /* Finally, enumerate all addresses, too */
246 r
= sd_rtnl_message_new_addr(m
->rtnl
, &req
, RTM_GETADDR
, 0, AF_UNSPEC
);
250 r
= sd_netlink_message_request_dump(req
, true);
254 r
= sd_netlink_call(m
->rtnl
, req
, 0, &reply
);
258 for (i
= reply
; i
; i
= sd_netlink_message_next(i
)) {
259 r
= manager_process_address(m
->rtnl
, i
, m
);
267 static int on_network_event(sd_event_source
*s
, int fd
, uint32_t revents
, void *userdata
) {
268 Manager
*m
= userdata
;
275 sd_network_monitor_flush(m
->network_monitor
);
277 HASHMAP_FOREACH(l
, m
->links
, i
) {
278 r
= link_update_monitor(l
);
280 log_warning_errno(r
, "Failed to update monitor information for %i: %m", l
->ifindex
);
283 r
= manager_write_resolv_conf(m
);
285 log_warning_errno(r
, "Could not update resolv.conf: %m");
290 static int manager_network_monitor_listen(Manager
*m
) {
295 r
= sd_network_monitor_new(&m
->network_monitor
, NULL
);
299 fd
= sd_network_monitor_get_fd(m
->network_monitor
);
303 events
= sd_network_monitor_get_events(m
->network_monitor
);
307 r
= sd_event_add_io(m
->event
, &m
->network_event_source
, fd
, events
, &on_network_event
, m
);
314 static int determine_hostname(char **ret
) {
315 _cleanup_free_
char *h
= NULL
, *n
= NULL
;
320 h
= gethostname_malloc();
324 if (!utf8_is_valid(h
)) {
325 log_error("System hostname is not UTF-8 clean.");
329 r
= dns_name_normalize(h
, &n
);
331 log_error("System hostname '%s' cannot be normalized.", h
);
341 static int on_hostname_change(sd_event_source
*es
, int fd
, uint32_t revents
, void *userdata
) {
342 _cleanup_free_
char *h
= NULL
;
343 Manager
*m
= userdata
;
348 r
= determine_hostname(&h
);
350 return 0; /* ignore invalid hostnames */
352 if (streq(h
, m
->hostname
))
355 log_info("System hostname changed to '%s'.", h
);
360 manager_refresh_rrs(m
);
365 static int manager_watch_hostname(Manager
*m
) {
370 m
->hostname_fd
= open("/proc/sys/kernel/hostname", O_RDONLY
|O_CLOEXEC
|O_NDELAY
|O_NOCTTY
);
371 if (m
->hostname_fd
< 0) {
372 log_warning_errno(errno
, "Failed to watch hostname: %m");
376 r
= sd_event_add_io(m
->event
, &m
->hostname_event_source
, m
->hostname_fd
, 0, on_hostname_change
, m
);
379 /* kernels prior to 3.2 don't support polling this file. Ignore the failure. */
380 m
->hostname_fd
= safe_close(m
->hostname_fd
);
382 return log_error_errno(r
, "Failed to add hostname event source: %m");
385 r
= determine_hostname(&m
->hostname
);
387 log_info("Defaulting to hostname 'linux'.");
388 m
->hostname
= strdup("linux");
392 log_info("Using system hostname '%s'.", m
->hostname
);
397 int manager_new(Manager
**ret
) {
398 _cleanup_(manager_freep
) Manager
*m
= NULL
;
403 m
= new0(Manager
, 1);
407 m
->llmnr_ipv4_udp_fd
= m
->llmnr_ipv6_udp_fd
= -1;
408 m
->llmnr_ipv4_tcp_fd
= m
->llmnr_ipv6_tcp_fd
= -1;
411 m
->llmnr_support
= SUPPORT_YES
;
412 m
->read_resolv_conf
= true;
414 r
= manager_parse_dns_server(m
, DNS_SERVER_FALLBACK
, DNS_SERVERS
);
418 r
= sd_event_default(&m
->event
);
422 sd_event_add_signal(m
->event
, NULL
, SIGTERM
, NULL
, NULL
);
423 sd_event_add_signal(m
->event
, NULL
, SIGINT
, NULL
, NULL
);
425 sd_event_set_watchdog(m
->event
, true);
427 r
= manager_watch_hostname(m
);
431 r
= dns_scope_new(m
, &m
->unicast_scope
, NULL
, DNS_PROTOCOL_DNS
, AF_UNSPEC
);
435 r
= manager_network_monitor_listen(m
);
439 r
= manager_rtnl_listen(m
);
443 r
= manager_connect_bus(m
);
453 int manager_start(Manager
*m
) {
458 r
= manager_llmnr_start(m
);
465 Manager
*manager_free(Manager
*m
) {
471 while ((l
= hashmap_first(m
->links
)))
474 while (m
->dns_queries
)
475 dns_query_free(m
->dns_queries
);
477 manager_flush_dns_servers(m
, DNS_SERVER_SYSTEM
);
478 manager_flush_dns_servers(m
, DNS_SERVER_FALLBACK
);
480 dns_scope_free(m
->unicast_scope
);
482 hashmap_free(m
->links
);
483 hashmap_free(m
->dns_transactions
);
485 sd_event_source_unref(m
->network_event_source
);
486 sd_network_monitor_unref(m
->network_monitor
);
488 manager_llmnr_stop(m
);
490 sd_bus_slot_unref(m
->prepare_for_sleep_slot
);
491 sd_event_source_unref(m
->bus_retry_event_source
);
492 sd_bus_unref(m
->bus
);
494 sd_event_unref(m
->event
);
496 dns_resource_key_unref(m
->host_ipv4_key
);
497 dns_resource_key_unref(m
->host_ipv6_key
);
499 safe_close(m
->hostname_fd
);
500 sd_event_source_unref(m
->hostname_event_source
);
508 int manager_read_resolv_conf(Manager
*m
) {
509 _cleanup_fclose_
FILE *f
= NULL
;
518 /* Reads the system /etc/resolv.conf, if it exists and is not
519 * symlinked to our own resolv.conf instance */
521 if (!m
->read_resolv_conf
)
524 r
= stat("/etc/resolv.conf", &st
);
527 log_warning_errno(errno
, "Failed to open /etc/resolv.conf: %m");
532 /* Have we already seen the file? */
533 t
= timespec_load(&st
.st_mtim
);
534 if (t
== m
->resolv_conf_mtime
)
537 m
->resolv_conf_mtime
= t
;
539 /* Is it symlinked to our own file? */
540 if (stat("/run/systemd/resolve/resolv.conf", &own
) >= 0 &&
541 st
.st_dev
== own
.st_dev
&&
542 st
.st_ino
== own
.st_ino
) {
547 f
= fopen("/etc/resolv.conf", "re");
550 log_warning_errno(errno
, "Failed to open /etc/resolv.conf: %m");
555 if (fstat(fileno(f
), &st
) < 0) {
556 log_error_errno(errno
, "Failed to stat open file: %m");
561 LIST_FOREACH(servers
, s
, m
->dns_servers
)
564 FOREACH_LINE(line
, f
, r
= -errno
; goto clear
) {
565 union in_addr_union address
;
573 if (*l
== '#' || *l
== ';')
576 a
= first_word(l
, "nameserver");
580 r
= in_addr_from_string_auto(a
, &family
, &address
);
582 log_warning("Failed to parse name server %s.", a
);
586 LIST_FOREACH(servers
, s
, m
->dns_servers
)
587 if (s
->family
== family
&& in_addr_equal(family
, &s
->address
, &address
) > 0)
593 r
= dns_server_new(m
, NULL
, DNS_SERVER_SYSTEM
, NULL
, family
, &address
);
599 LIST_FOREACH_SAFE(servers
, s
, nx
, m
->dns_servers
)
601 LIST_REMOVE(servers
, m
->dns_servers
, s
);
605 /* Whenever /etc/resolv.conf changes, start using the first
606 * DNS server of it. This is useful to deal with broken
607 * network managing implementations (like NetworkManager),
608 * that when connecting to a VPN place both the VPN DNS
609 * servers and the local ones in /etc/resolv.conf. Without
610 * resetting the DNS server to use back to the first entry we
611 * will continue to use the local one thus being unable to
612 * resolve VPN domains. */
613 manager_set_dns_server(m
, m
->dns_servers
);
618 while (m
->dns_servers
) {
621 LIST_REMOVE(servers
, m
->dns_servers
, s
);
628 static void write_resolv_conf_server(DnsServer
*s
, FILE *f
, unsigned *count
) {
629 _cleanup_free_
char *t
= NULL
;
636 r
= in_addr_to_string(s
->family
, &s
->address
, &t
);
638 log_warning_errno(r
, "Invalid DNS address. Ignoring: %m");
643 fputs("# Too many DNS servers configured, the following entries may be ignored.\n", f
);
645 fprintf(f
, "nameserver %s\n", t
);
649 static void write_resolv_conf_search(
650 const char *domain
, FILE *f
,
658 if (*count
>= MAXDNSRCH
||
659 *length
+ strlen(domain
) > 256) {
660 if (*count
== MAXDNSRCH
)
661 fputs(" # Too many search domains configured, remaining ones ignored.", f
);
663 fputs(" # Total length of all search domains is too long, remaining ones ignored.", f
);
668 fprintf(f
, " %s", domain
);
670 (*length
) += strlen(domain
);
674 static int write_resolv_conf_contents(FILE *f
, OrderedSet
*dns
, OrderedSet
*domains
) {
677 fputs("# This file is managed by systemd-resolved(8). Do not edit.\n#\n"
678 "# Third party programs must not access this file directly, but\n"
679 "# only through the symlink at /etc/resolv.conf. To manage\n"
680 "# resolv.conf(5) in a different way, replace the symlink by a\n"
681 "# static file or a different symlink.\n\n", f
);
683 if (ordered_set_isempty(dns
))
684 fputs("# No DNS servers known.\n", f
);
689 ORDERED_SET_FOREACH(s
, dns
, i
)
690 write_resolv_conf_server(s
, f
, &count
);
693 if (!ordered_set_isempty(domains
)) {
694 unsigned length
= 0, count
= 0;
698 ORDERED_SET_FOREACH(domain
, domains
, i
)
699 write_resolv_conf_search(domain
, f
, &count
, &length
);
703 return fflush_and_check(f
);
706 int manager_write_resolv_conf(Manager
*m
) {
707 static const char path
[] = "/run/systemd/resolve/resolv.conf";
708 _cleanup_free_
char *temp_path
= NULL
;
709 _cleanup_fclose_
FILE *f
= NULL
;
710 _cleanup_ordered_set_free_ OrderedSet
*dns
= NULL
, *domains
= NULL
;
718 /* Read the system /etc/resolv.conf first */
719 manager_read_resolv_conf(m
);
721 /* Add the full list to a set, to filter out duplicates */
722 dns
= ordered_set_new(&dns_server_hash_ops
);
726 domains
= ordered_set_new(&dns_name_hash_ops
);
730 /* First add the system-wide servers */
731 LIST_FOREACH(servers
, s
, m
->dns_servers
) {
732 r
= ordered_set_put(dns
, s
);
739 /* Then, add the per-link servers and domains */
740 HASHMAP_FOREACH(l
, m
->links
, i
) {
743 LIST_FOREACH(servers
, s
, l
->dns_servers
) {
744 r
= ordered_set_put(dns
, s
);
751 if (!l
->unicast_scope
)
754 STRV_FOREACH(domain
, l
->unicast_scope
->domains
) {
755 r
= ordered_set_put(domains
, *domain
);
763 /* If we found nothing, add the fallback servers */
764 if (ordered_set_isempty(dns
)) {
765 LIST_FOREACH(servers
, s
, m
->fallback_dns_servers
) {
766 r
= ordered_set_put(dns
, s
);
774 r
= fopen_temporary_label(path
, path
, &f
, &temp_path
);
778 fchmod(fileno(f
), 0644);
780 r
= write_resolv_conf_contents(f
, dns
, domains
);
784 if (rename(temp_path
, path
) < 0) {
793 (void) unlink(temp_path
);
797 int manager_recv(Manager
*m
, int fd
, DnsProtocol protocol
, DnsPacket
**ret
) {
798 _cleanup_(dns_packet_unrefp
) DnsPacket
*p
= NULL
;
800 struct cmsghdr header
; /* For alignment */
801 uint8_t buffer
[CMSG_SPACE(MAXSIZE(struct in_pktinfo
, struct in6_pktinfo
))
802 + CMSG_SPACE(int) /* ttl/hoplimit */
803 + EXTRA_CMSG_SPACE
/* kernel appears to require extra buffer space */];
805 union sockaddr_union sa
;
806 struct msghdr mh
= {};
807 struct cmsghdr
*cmsg
;
816 r
= ioctl(fd
, FIONREAD
, &ms
);
822 r
= dns_packet_new(&p
, protocol
, ms
);
826 iov
.iov_base
= DNS_PACKET_DATA(p
);
827 iov
.iov_len
= p
->allocated
;
829 mh
.msg_name
= &sa
.sa
;
830 mh
.msg_namelen
= sizeof(sa
);
833 mh
.msg_control
= &control
;
834 mh
.msg_controllen
= sizeof(control
);
836 l
= recvmsg(fd
, &mh
, 0);
838 if (errno
== EAGAIN
|| errno
== EINTR
)
847 assert(!(mh
.msg_flags
& MSG_CTRUNC
));
848 assert(!(mh
.msg_flags
& MSG_TRUNC
));
850 p
->size
= (size_t) l
;
852 p
->family
= sa
.sa
.sa_family
;
853 p
->ipproto
= IPPROTO_UDP
;
854 if (p
->family
== AF_INET
) {
855 p
->sender
.in
= sa
.in
.sin_addr
;
856 p
->sender_port
= be16toh(sa
.in
.sin_port
);
857 } else if (p
->family
== AF_INET6
) {
858 p
->sender
.in6
= sa
.in6
.sin6_addr
;
859 p
->sender_port
= be16toh(sa
.in6
.sin6_port
);
860 p
->ifindex
= sa
.in6
.sin6_scope_id
;
862 return -EAFNOSUPPORT
;
864 CMSG_FOREACH(cmsg
, &mh
) {
866 if (cmsg
->cmsg_level
== IPPROTO_IPV6
) {
867 assert(p
->family
== AF_INET6
);
869 switch (cmsg
->cmsg_type
) {
872 struct in6_pktinfo
*i
= (struct in6_pktinfo
*) CMSG_DATA(cmsg
);
875 p
->ifindex
= i
->ipi6_ifindex
;
877 p
->destination
.in6
= i
->ipi6_addr
;
882 p
->ttl
= *(int *) CMSG_DATA(cmsg
);
886 } else if (cmsg
->cmsg_level
== IPPROTO_IP
) {
887 assert(p
->family
== AF_INET
);
889 switch (cmsg
->cmsg_type
) {
892 struct in_pktinfo
*i
= (struct in_pktinfo
*) CMSG_DATA(cmsg
);
895 p
->ifindex
= i
->ipi_ifindex
;
897 p
->destination
.in
= i
->ipi_addr
;
902 p
->ttl
= *(int *) CMSG_DATA(cmsg
);
908 /* The Linux kernel sets the interface index to the loopback
909 * device if the packet came from the local host since it
910 * avoids the routing table in such a case. Let's unset the
911 * interface index in such a case. */
912 if (p
->ifindex
== LOOPBACK_IFINDEX
)
915 /* If we don't know the interface index still, we look for the
916 * first local interface with a matching address. Yuck! */
918 p
->ifindex
= manager_find_ifindex(m
, p
->family
, &p
->destination
);
926 static int sendmsg_loop(int fd
, struct msghdr
*mh
, int flags
) {
933 if (sendmsg(fd
, mh
, flags
) >= 0)
942 r
= fd_wait_for_event(fd
, POLLOUT
, SEND_TIMEOUT_USEC
);
950 static int manager_ipv4_send(Manager
*m
, int fd
, int ifindex
, const struct in_addr
*addr
, uint16_t port
, DnsPacket
*p
) {
951 union sockaddr_union sa
= {
952 .in
.sin_family
= AF_INET
,
955 struct cmsghdr header
; /* For alignment */
956 uint8_t buffer
[CMSG_SPACE(sizeof(struct in_pktinfo
))];
958 struct msghdr mh
= {};
967 iov
.iov_base
= DNS_PACKET_DATA(p
);
968 iov
.iov_len
= p
->size
;
970 sa
.in
.sin_addr
= *addr
;
971 sa
.in
.sin_port
= htobe16(port
),
975 mh
.msg_name
= &sa
.sa
;
976 mh
.msg_namelen
= sizeof(sa
.in
);
979 struct cmsghdr
*cmsg
;
980 struct in_pktinfo
*pi
;
984 mh
.msg_control
= &control
;
985 mh
.msg_controllen
= CMSG_LEN(sizeof(struct in_pktinfo
));
987 cmsg
= CMSG_FIRSTHDR(&mh
);
988 cmsg
->cmsg_len
= mh
.msg_controllen
;
989 cmsg
->cmsg_level
= IPPROTO_IP
;
990 cmsg
->cmsg_type
= IP_PKTINFO
;
992 pi
= (struct in_pktinfo
*) CMSG_DATA(cmsg
);
993 pi
->ipi_ifindex
= ifindex
;
996 return sendmsg_loop(fd
, &mh
, 0);
999 static int manager_ipv6_send(Manager
*m
, int fd
, int ifindex
, const struct in6_addr
*addr
, uint16_t port
, DnsPacket
*p
) {
1000 union sockaddr_union sa
= {
1001 .in6
.sin6_family
= AF_INET6
,
1004 struct cmsghdr header
; /* For alignment */
1005 uint8_t buffer
[CMSG_SPACE(sizeof(struct in6_pktinfo
))];
1007 struct msghdr mh
= {};
1016 iov
.iov_base
= DNS_PACKET_DATA(p
);
1017 iov
.iov_len
= p
->size
;
1019 sa
.in6
.sin6_addr
= *addr
;
1020 sa
.in6
.sin6_port
= htobe16(port
),
1021 sa
.in6
.sin6_scope_id
= ifindex
;
1025 mh
.msg_name
= &sa
.sa
;
1026 mh
.msg_namelen
= sizeof(sa
.in6
);
1029 struct cmsghdr
*cmsg
;
1030 struct in6_pktinfo
*pi
;
1034 mh
.msg_control
= &control
;
1035 mh
.msg_controllen
= CMSG_LEN(sizeof(struct in6_pktinfo
));
1037 cmsg
= CMSG_FIRSTHDR(&mh
);
1038 cmsg
->cmsg_len
= mh
.msg_controllen
;
1039 cmsg
->cmsg_level
= IPPROTO_IPV6
;
1040 cmsg
->cmsg_type
= IPV6_PKTINFO
;
1042 pi
= (struct in6_pktinfo
*) CMSG_DATA(cmsg
);
1043 pi
->ipi6_ifindex
= ifindex
;
1046 return sendmsg_loop(fd
, &mh
, 0);
1049 int manager_send(Manager
*m
, int fd
, int ifindex
, int family
, const union in_addr_union
*addr
, uint16_t port
, DnsPacket
*p
) {
1056 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
));
1058 if (family
== AF_INET
)
1059 return manager_ipv4_send(m
, fd
, ifindex
, &addr
->in
, port
, p
);
1060 else if (family
== AF_INET6
)
1061 return manager_ipv6_send(m
, fd
, ifindex
, &addr
->in6
, port
, p
);
1063 return -EAFNOSUPPORT
;
1066 DnsServer
* manager_find_dns_server(Manager
*m
, int family
, const union in_addr_union
*in_addr
) {
1072 LIST_FOREACH(servers
, s
, m
->dns_servers
)
1073 if (s
->family
== family
&& in_addr_equal(family
, &s
->address
, in_addr
) > 0)
1076 LIST_FOREACH(servers
, s
, m
->fallback_dns_servers
)
1077 if (s
->family
== family
&& in_addr_equal(family
, &s
->address
, in_addr
) > 0)
1083 DnsServer
*manager_set_dns_server(Manager
*m
, DnsServer
*s
) {
1086 if (m
->current_dns_server
== s
)
1090 _cleanup_free_
char *ip
= NULL
;
1092 in_addr_to_string(s
->family
, &s
->address
, &ip
);
1093 log_info("Switching to system DNS server %s.", strna(ip
));
1096 m
->current_dns_server
= s
;
1098 if (m
->unicast_scope
)
1099 dns_cache_flush(&m
->unicast_scope
->cache
);
1104 DnsServer
*manager_get_dns_server(Manager
*m
) {
1108 /* Try to read updates resolv.conf */
1109 manager_read_resolv_conf(m
);
1111 if (!m
->current_dns_server
)
1112 manager_set_dns_server(m
, m
->dns_servers
);
1114 if (!m
->current_dns_server
) {
1118 /* No DNS servers configured, let's see if there are
1119 * any on any links. If not, we use the fallback
1122 HASHMAP_FOREACH(l
, m
->links
, i
)
1123 if (l
->dns_servers
) {
1129 manager_set_dns_server(m
, m
->fallback_dns_servers
);
1132 return m
->current_dns_server
;
1135 void manager_next_dns_server(Manager
*m
) {
1138 /* If there's currently no DNS server set, then the next
1139 * manager_get_dns_server() will find one */
1140 if (!m
->current_dns_server
)
1143 /* Change to the next one */
1144 if (m
->current_dns_server
->servers_next
) {
1145 manager_set_dns_server(m
, m
->current_dns_server
->servers_next
);
1149 /* If there was no next one, then start from the beginning of
1151 if (m
->current_dns_server
->type
== DNS_SERVER_FALLBACK
)
1152 manager_set_dns_server(m
, m
->fallback_dns_servers
);
1154 manager_set_dns_server(m
, m
->dns_servers
);
1157 uint32_t manager_find_mtu(Manager
*m
) {
1162 /* If we don't know on which link a DNS packet would be
1163 * delivered, let's find the largest MTU that works on all
1164 * interfaces we know of */
1166 HASHMAP_FOREACH(l
, m
->links
, i
) {
1170 if (mtu
<= 0 || l
->mtu
< mtu
)
1177 int manager_find_ifindex(Manager
*m
, int family
, const union in_addr_union
*in_addr
) {
1182 a
= manager_find_link_address(m
, family
, in_addr
);
1184 return a
->link
->ifindex
;
1189 void manager_refresh_rrs(Manager
*m
) {
1195 m
->host_ipv4_key
= dns_resource_key_unref(m
->host_ipv4_key
);
1196 m
->host_ipv6_key
= dns_resource_key_unref(m
->host_ipv6_key
);
1198 HASHMAP_FOREACH(l
, m
->links
, i
) {
1199 link_add_rrs(l
, true);
1200 link_add_rrs(l
, false);
1204 int manager_next_hostname(Manager
*m
) {
1211 p
= strchr(m
->hostname
, 0);
1214 while (p
> m
->hostname
) {
1215 if (!strchr("0123456789", p
[-1]))
1221 if (*p
== 0 || safe_atou64(p
, &u
) < 0 || u
<= 0)
1224 /* Add a random number to the old value. This way we can avoid
1225 * that two hosts pick the same hostname, win on IPv4 and lose
1226 * on IPv6 (or vice versa), and pick the same hostname
1227 * replacement hostname, ad infinitum. We still want the
1228 * numbers to go up monotonically, hence we just add a random
1231 random_bytes(&a
, sizeof(a
));
1234 if (asprintf(&h
, "%.*s%" PRIu64
, (int) (p
- m
->hostname
), m
->hostname
, u
) < 0)
1237 log_info("Hostname conflict, changing published hostname from '%s' to '%s'.", m
->hostname
, h
);
1242 manager_refresh_rrs(m
);
1247 LinkAddress
* manager_find_link_address(Manager
*m
, int family
, const union in_addr_union
*in_addr
) {
1253 HASHMAP_FOREACH(l
, m
->links
, i
) {
1256 a
= link_find_address(l
, family
, in_addr
);
1264 bool manager_our_packet(Manager
*m
, DnsPacket
*p
) {
1268 return !!manager_find_link_address(m
, p
->family
, &p
->sender
);
1271 DnsScope
* manager_find_scope(Manager
*m
, DnsPacket
*p
) {
1277 l
= hashmap_get(m
->links
, INT_TO_PTR(p
->ifindex
));
1281 if (p
->protocol
== DNS_PROTOCOL_LLMNR
) {
1282 if (p
->family
== AF_INET
)
1283 return l
->llmnr_ipv4_scope
;
1284 else if (p
->family
== AF_INET6
)
1285 return l
->llmnr_ipv6_scope
;
1291 void manager_verify_all(Manager
*m
) {
1296 LIST_FOREACH(scopes
, s
, m
->dns_scopes
)
1297 dns_zone_verify_all(&s
->zone
);
1300 void manager_flush_dns_servers(Manager
*m
, DnsServerType t
) {
1305 if (t
== DNS_SERVER_SYSTEM
)
1306 while (m
->dns_servers
) {
1309 LIST_REMOVE(servers
, m
->dns_servers
, s
);
1310 dns_server_unref(s
);
1313 if (t
== DNS_SERVER_FALLBACK
)
1314 while (m
->fallback_dns_servers
) {
1315 s
= m
->fallback_dns_servers
;
1317 LIST_REMOVE(servers
, m
->fallback_dns_servers
, s
);
1318 dns_server_unref(s
);
1322 static const char* const support_table
[_SUPPORT_MAX
] = {
1323 [SUPPORT_NO
] = "no",
1324 [SUPPORT_YES
] = "yes",
1325 [SUPPORT_RESOLVE
] = "resolve",
1327 DEFINE_STRING_TABLE_LOOKUP(support
, Support
);