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Merge pull request #8849 from irtimmer/feature/dns-over-tls

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resolve: Support for DNS-over-TLS
This commit is contained in:
Lennart Poettering 2018-06-12 20:45:39 +02:00 committed by GitHub
commit 401e860cb8
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36 changed files with 916 additions and 118 deletions
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13
man/resolvectl.xml
View File

@ -257,6 +257,7 @@
<term><option>llmnr [<replaceable>LINK</replaceable> [<replaceable>MODE</replaceable>]]</option></term>
<term><option>mdns [<replaceable>LINK</replaceable> [<replaceable>MODE</replaceable>]]</option></term>
<term><option>dnssec [<replaceable>LINK</replaceable> [<replaceable>MODE</replaceable>]]</option></term>
<term><option>privatedns [<replaceable>LINK</replaceable> [<replaceable>MODE</replaceable>]]</option></term>
<term><option>nta [<replaceable>LINK</replaceable> [<replaceable>DOMAIN</replaceable>…]]</option></term>
<listitem><para>Get/set per-interface DNS configuration. These commands may be used to configure various DNS
@ -268,10 +269,10 @@
through external means. The <option>dns</option> command expects IPv4 or IPv6 address specifications of DNS
servers to use. The <option>domain</option> command expects valid DNS domains, possibly prefixed with
<literal>~</literal>, and configures a per-interface search or route-only domain. The <option>llmnr</option>,
<option>mdns</option> and <option>dnssec</option> commands may be used to configure the per-interface LLMNR,
MulticastDNS and DNSSEC settings. Finally, <option>nta</option> command may be used to configure additional
per-interface DNSSEC NTA domains. For details about these settings, their possible values and their effect,
see the corresponding options in
<option>mdns</option>, <option>dnssec</option> and <option>privatedns</option> commands may be used to configure
the per-interface LLMNR, MulticastDNS, DNSSEC and PrivateDNS settings. Finally, <option>nta</option> command
may be used to configure additional per-interface DNSSEC NTA domains. For details about these settings, their
possible values and their effect, see the corresponding options in
<citerefentry><refentrytitle>systemd.network</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para>
</listitem>
</varlistentry>
@ -282,8 +283,8 @@
<listitem><para>Revert the per-interface DNS configuration. If the DNS configuration is reverted all
per-interface DNS setting are reset to their defaults, undoing all effects of <option>dns</option>,
<option>domain</option>, <option>llmnr</option>, <option>mdns</option>, <option>dnssec</option>,
<option>nta=</option>. Note that when a network interface disappears all configuration is lost automatically,
an explicit reverting is not necessary in that case.</para></listitem>
<option>privatedns</option>, <option>nta=</option>. Note that when a network interface disappears all
configuration is lost automatically, an explicit reverting is not necessary in that case.</para></listitem>
</varlistentry>
</variablelist>

32
man/resolved.conf.xml
View File

@ -206,6 +206,38 @@
</listitem>
</varlistentry>
<varlistentry>
<term><varname>PrivateDNS=</varname></term>
<listitem>
<para>Takes false or
<literal>opportunistic</literal>. When set to <literal>opportunistic</literal>
DNS request are attempted to send encrypted with DNS-over-TLS.
If the DNS server does not support TLS, DNS-over-TLS is disabled.
Note that this mode makes DNS-over-TLS vulnerable to "downgrade"
attacks, where an attacker might be able to trigger a downgrade
to non-encrypted mode by synthesizing a response that suggests
DNS-over-TLS was not supported. If set to false, DNS lookups
are send over UDP.</para>
<para>Note that DNS-over-TLS requires additional data to be
send for setting up an encrypted connection, and thus results
in a small DNS look-up time penalty.</para>
<para>Note as the resolver is not capable of authenticating
the server, it is vulnerable for "man-in-the-middle" attacks.</para>
<para>In addition to this global PrivateDNS setting
<citerefentry><refentrytitle>systemd-networkd.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>
also maintains per-link PrivateDNS settings. For system DNS
servers (see above), only the global PrivateDNS setting is in
effect. For per-link DNS servers the per-link
setting is in effect, unless it is unset in which case the
global setting is used instead.</para>
<para>Defaults to off.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>Cache=</varname></term>
<listitem><para>Takes a boolean argument. If "yes" (the default), resolving a domain name which already got

15
man/systemd.network.xml
View File

@ -384,6 +384,21 @@
<citerefentry><refentrytitle>systemd-resolved.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>PrivateDNS=</varname></term>
<listitem>
<para>Takes false or
<literal>opportunistic</literal>. When set to <literal>opportunistic</literal>, enables
<ulink
url="https://tools.ietf.org/html/rfc7858">DNS-over-TLS</ulink>
support on the link. This option defines a
per-interface setting for
<citerefentry><refentrytitle>resolved.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>'s
global <varname>PrivateDNS=</varname> option. Defaults to
false. This setting is read by
<citerefentry><refentrytitle>systemd-resolved.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>DNSSEC=</varname></term>
<listitem>

14
meson.build
View File

@ -1137,6 +1137,18 @@ conf.set('DEFAULT_DNSSEC_MODE',
'DNSSEC_' + default_dnssec.underscorify().to_upper())
substs.set('DEFAULT_DNSSEC_MODE', default_dnssec)
default_private_dns = get_option('default-private-dns')
if fuzzer_build
default_private_dns = 'no'
endif
if default_private_dns != 'no' and conf.get('HAVE_GNUTLS') == 0
message('default-private-dns cannot be set to strict or opportunistic when gnutls is disabled. Setting default-private-dns to no.')
default_private_dns = 'no'
endif
conf.set('DEFAULT_PRIVATE_DNS_MODE',
'PRIVATE_DNS_' + default_private_dns.underscorify().to_upper())
substs.set('DEFAULT_PRIVATE_DNS_MODE', default_private_dns)
want_importd = get_option('importd')
if want_importd != 'false'
have = (conf.get('HAVE_LIBCURL') == 1 and
@ -1585,6 +1597,7 @@ if conf.get('ENABLE_RESOLVE') == 1
libbasic_gcrypt,
libsystemd_resolve_core],
dependencies : [threads,
libgnutls,
libgpg_error,
libm,
libidn],
@ -2857,6 +2870,7 @@ status = [
'symbolic gateway hostnames: @0@'.format(', '.join(gateway_hostnames)),
'default DNSSEC mode: @0@'.format(default_dnssec),
'default private DNS mode: @0@'.format(default_private_dns),
'default cgroup hierarchy: @0@'.format(default_hierarchy),
'default KillUserProcesses setting: @0@'.format(kill_user_processes)]

4
meson_options.txt
View File

@ -193,6 +193,10 @@ option('default-dnssec', type : 'combo',
description : 'default DNSSEC mode',
choices : ['yes', 'allow-downgrade', 'no'],
value : 'allow-downgrade')
option('default-private-dns', type : 'combo',
description : 'default private DNS mode',
choices : ['opportunistic', 'no'],
value : 'no')
option('dns-servers', type : 'string',
description : 'space-separated list of default DNS servers',
value : '8.8.8.8 8.8.4.4 2001:4860:4860::8888 2001:4860:4860::8844')

8
src/basic/ordered-set.h
View File

@ -48,6 +48,14 @@ static inline bool ordered_set_iterate(OrderedSet *s, Iterator *i, void **value)
return ordered_hashmap_iterate((OrderedHashmap*) s, i, value, NULL);
}
static inline void* ordered_set_remove(OrderedSet *s, void *p) {
return ordered_hashmap_remove((OrderedHashmap*) s, p);
}
static inline void* ordered_set_steal_first(OrderedSet *s) {
return ordered_hashmap_steal_first((OrderedHashmap*) s);
}
int ordered_set_consume(OrderedSet *s, void *p);
int ordered_set_put_strdup(OrderedSet *s, const char *p);
int ordered_set_put_strdupv(OrderedSet *s, char **l);

4
src/libsystemd/sd-network/sd-network.c
View File

@ -178,6 +178,10 @@ _public_ int sd_network_link_get_mdns(int ifindex, char **mdns) {
return network_link_get_string(ifindex, "MDNS", mdns);
}
_public_ int sd_network_link_get_private_dns(int ifindex, char **private_dns) {
return network_link_get_string(ifindex, "PRIVATE_DNS", private_dns);
}
_public_ int sd_network_link_get_dnssec(int ifindex, char **dnssec) {
return network_link_get_string(ifindex, "DNSSEC", dnssec);
}

4
src/network/networkd-link.c
View File

@ -3762,6 +3762,10 @@ int link_save(Link *link) {
fprintf(f, "MDNS=%s\n",
resolve_support_to_string(link->network->mdns));
if (link->network->private_dns_mode != _PRIVATE_DNS_MODE_INVALID)
fprintf(f, "PRIVATE_DNS=%s\n",
private_dns_mode_to_string(link->network->private_dns_mode));
if (link->network->dnssec_mode != _DNSSEC_MODE_INVALID)
fprintf(f, "DNSSEC=%s\n",
dnssec_mode_to_string(link->network->dnssec_mode));

1
src/network/networkd-network-gperf.gperf
View File

@ -60,6 +60,7 @@ Network.Domains, config_parse_domains,
Network.DNS, config_parse_dns, 0, 0
Network.LLMNR, config_parse_resolve_support, 0, offsetof(Network, llmnr)
Network.MulticastDNS, config_parse_resolve_support, 0, offsetof(Network, mdns)
Network.PrivateDNS, config_parse_private_dns_mode, 0, offsetof(Network, private_dns_mode)
Network.DNSSEC, config_parse_dnssec_mode, 0, offsetof(Network, dnssec_mode)
Network.DNSSECNegativeTrustAnchors, config_parse_dnssec_negative_trust_anchors, 0, 0
Network.NTP, config_parse_ntp, 0, offsetof(Network, ntp)

1
src/network/networkd-network.c
View File

@ -236,6 +236,7 @@ static int network_load_one(Manager *manager, const char *filename) {
network->llmnr = RESOLVE_SUPPORT_YES;
network->mdns = RESOLVE_SUPPORT_NO;
network->dnssec_mode = _DNSSEC_MODE_INVALID;
network->private_dns_mode = _PRIVATE_DNS_MODE_INVALID;
network->link_local = ADDRESS_FAMILY_IPV6;

1
src/network/networkd-network.h
View File

@ -261,6 +261,7 @@ struct Network {
ResolveSupport llmnr;
ResolveSupport mdns;
DnssecMode dnssec_mode;
PrivateDnsMode private_dns_mode;
Set *dnssec_negative_trust_anchors;
LIST_FIELDS(Network, networks);

89
src/resolve/resolvectl.c
View File

@ -56,6 +56,7 @@ char **arg_set_dns = NULL;
char **arg_set_domain = NULL;
static const char *arg_set_llmnr = NULL;
static const char *arg_set_mdns = NULL;
static const char *arg_set_private_dns = NULL;
static const char *arg_set_dnssec = NULL;
static char **arg_set_nta = NULL;
@ -65,6 +66,7 @@ typedef enum StatusMode {
STATUS_DOMAIN,
STATUS_LLMNR,
STATUS_MDNS,
STATUS_PRIVATE,
STATUS_DNSSEC,
STATUS_NTA,
} StatusMode;
@ -1337,6 +1339,7 @@ static int status_ifindex(sd_bus *bus, int ifindex, const char *name, StatusMode
uint64_t scopes_mask;
const char *llmnr;
const char *mdns;
const char *private_dns;
const char *dnssec;
char *current_dns;
char **dns;
@ -1352,6 +1355,7 @@ static int status_ifindex(sd_bus *bus, int ifindex, const char *name, StatusMode
{ "Domains", "a(sb)", map_link_domains, offsetof(struct link_info, domains) },
{ "LLMNR", "s", NULL, offsetof(struct link_info, llmnr) },
{ "MulticastDNS", "s", NULL, offsetof(struct link_info, mdns) },
{ "PrivateDNS", "s", NULL, offsetof(struct link_info, private_dns) },
{ "DNSSEC", "s", NULL, offsetof(struct link_info, dnssec) },
{ "DNSSECNegativeTrustAnchors", "as", NULL, offsetof(struct link_info, ntas) },
{ "DNSSECSupported", "b", NULL, offsetof(struct link_info, dnssec_supported) },
@ -1430,6 +1434,15 @@ static int status_ifindex(sd_bus *bus, int ifindex, const char *name, StatusMode
goto finish;
}
if (mode == STATUS_PRIVATE) {
printf("%sLink %i (%s)%s: %s\n",
ansi_highlight(), ifindex, name, ansi_normal(),
strna(link_info.private_dns));
r = 0;
goto finish;
}
if (mode == STATUS_DNSSEC) {
printf("%sLink %i (%s)%s: %s\n",
ansi_highlight(), ifindex, name, ansi_normal(),
@ -1457,10 +1470,12 @@ static int status_ifindex(sd_bus *bus, int ifindex, const char *name, StatusMode
printf(" LLMNR setting: %s\n"
"MulticastDNS setting: %s\n"
" PrivateDNS setting: %s\n"
" DNSSEC setting: %s\n"
" DNSSEC supported: %s\n",
strna(link_info.llmnr),
strna(link_info.mdns),
strna(link_info.private_dns),
strna(link_info.dnssec),
yes_no(link_info.dnssec_supported));
@ -1602,6 +1617,7 @@ static int status_global(sd_bus *bus, StatusMode mode, bool *empty_line) {
char **ntas;
const char *llmnr;
const char *mdns;
const char *private_dns;
const char *dnssec;
bool dnssec_supported;
} global_info = {};
@ -1614,6 +1630,7 @@ static int status_global(sd_bus *bus, StatusMode mode, bool *empty_line) {
{ "DNSSECNegativeTrustAnchors", "as", NULL, offsetof(struct global_info, ntas) },
{ "LLMNR", "s", NULL, offsetof(struct global_info, llmnr) },
{ "MulticastDNS", "s", NULL, offsetof(struct global_info, mdns) },
{ "PrivateDNS", "s", NULL, offsetof(struct global_info, private_dns) },
{ "DNSSEC", "s", NULL, offsetof(struct global_info, dnssec) },
{ "DNSSECSupported", "b", NULL, offsetof(struct global_info, dnssec_supported) },
{}
@ -1673,6 +1690,14 @@ static int status_global(sd_bus *bus, StatusMode mode, bool *empty_line) {
goto finish;
}
if (mode == STATUS_PRIVATE) {
printf("%sGlobal%s: %s\n", ansi_highlight(), ansi_normal(),
strna(global_info.private_dns));
r = 0;
goto finish;
}
if (mode == STATUS_DNSSEC) {
printf("%sGlobal%s: %s\n", ansi_highlight(), ansi_normal(),
strna(global_info.dnssec));
@ -1685,10 +1710,12 @@ static int status_global(sd_bus *bus, StatusMode mode, bool *empty_line) {
printf(" LLMNR setting: %s\n"
"MulticastDNS setting: %s\n"
" PrivateDNS setting: %s\n"
" DNSSEC setting: %s\n"
" DNSSEC supported: %s\n",
strna(global_info.llmnr),
strna(global_info.mdns),
strna(global_info.private_dns),
strna(global_info.dnssec),
yes_no(global_info.dnssec_supported));
@ -2081,6 +2108,50 @@ static int verb_mdns(int argc, char **argv, void *userdata) {
return 0;
}
static int verb_private_dns(int argc, char **argv, void *userdata) {
_cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
sd_bus *bus = userdata;
int ifindex, r;
assert(bus);
if (argc <= 1)
return status_all(bus, STATUS_PRIVATE);
ifindex = parse_ifindex_with_warn(argv[1]);
if (ifindex < 0)
return ifindex;
if (ifindex == LOOPBACK_IFINDEX) {
log_error("Interface can't be the loopback interface (lo). Sorry.");
return -EINVAL;
}
if (argc == 2)
return status_ifindex(bus, ifindex, NULL, STATUS_PRIVATE, NULL);
r = sd_bus_call_method(bus,
"org.freedesktop.resolve1",
"/org/freedesktop/resolve1",
"org.freedesktop.resolve1.Manager",
"SetLinkPrivateDNS",
&error,
NULL,
"is", ifindex, argv[2]);
if (r < 0) {
if (sd_bus_error_has_name(&error, BUS_ERROR_LINK_BUSY))
return log_interface_is_managed(r, ifindex);
if (arg_ifindex_permissive &&
sd_bus_error_has_name(&error, BUS_ERROR_NO_SUCH_LINK))
return 0;
return log_error_errno(r, "Failed to set PrivateDNS configuration: %s", bus_error_message(&error, r));
}
return 0;
}
static int verb_dnssec(int argc, char **argv, void *userdata) {
_cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
sd_bus *bus = userdata;
@ -2283,6 +2354,7 @@ static void compat_help(void) {
" --set-domain=DOMAIN Set per-interface search domain\n"
" --set-llmnr=MODE Set per-interface LLMNR mode\n"
" --set-mdns=MODE Set per-interface MulticastDNS mode\n"
" --set-privatedns=MODE Set per-interface PrivateDNS mode\n"
" --set-dnssec=MODE Set per-interface DNSSEC mode\n"
" --set-nta=DOMAIN Set per-interface DNSSEC NTA\n"
" --revert Revert per-interface configuration\n"
@ -2326,6 +2398,7 @@ static void native_help(void) {
" domain [LINK [DOMAIN...]] Get/set per-interface search domain\n"
" llmnr [LINK [MODE]] Get/set per-interface LLMNR mode\n"
" mdns [LINK [MODE]] Get/set per-interface MulticastDNS mode\n"
" privatedns [LINK [MODE]] Get/set per-interface PrivateDNS mode\n"
" dnssec [LINK [MODE]] Get/set per-interface DNSSEC mode\n"
" nta [LINK [DOMAIN...]] Get/set per-interface DNSSEC NTA\n"
" revert LINK Revert per-interface configuration\n"
@ -2359,6 +2432,7 @@ static int compat_parse_argv(int argc, char *argv[]) {
ARG_SET_DOMAIN,
ARG_SET_LLMNR,
ARG_SET_MDNS,
ARG_SET_PRIVATE,
ARG_SET_DNSSEC,
ARG_SET_NTA,
ARG_REVERT_LINK,
@ -2390,6 +2464,7 @@ static int compat_parse_argv(int argc, char *argv[]) {
{ "set-domain", required_argument, NULL, ARG_SET_DOMAIN },
{ "set-llmnr", required_argument, NULL, ARG_SET_LLMNR },
{ "set-mdns", required_argument, NULL, ARG_SET_MDNS },
{ "set-privatedns", required_argument, NULL, ARG_SET_PRIVATE },
{ "set-dnssec", required_argument, NULL, ARG_SET_DNSSEC },
{ "set-nta", required_argument, NULL, ARG_SET_NTA },
{ "revert", no_argument, NULL, ARG_REVERT_LINK },
@ -2608,6 +2683,11 @@ static int compat_parse_argv(int argc, char *argv[]) {
arg_mode = MODE_SET_LINK;
break;
case ARG_SET_PRIVATE:
arg_set_private_dns = optarg;
arg_mode = MODE_SET_LINK;
break;
case ARG_SET_DNSSEC:
arg_set_dnssec = optarg;
arg_mode = MODE_SET_LINK;
@ -2651,7 +2731,7 @@ static int compat_parse_argv(int argc, char *argv[]) {
if (IN_SET(arg_mode, MODE_SET_LINK, MODE_REVERT_LINK)) {
if (arg_ifindex <= 0) {
log_error("--set-dns=, --set-domain=, --set-llmnr=, --set-mdns=, --set-dnssec=, --set-nta= and --revert require --interface=.");
log_error("--set-dns=, --set-domain=, --set-llmnr=, --set-mdns=, --set-privatedns=, --set-dnssec=, --set-nta= and --revert require --interface=.");
return -EINVAL;
}
@ -2877,6 +2957,7 @@ static int native_main(int argc, char *argv[], sd_bus *bus) {
{ "domain", VERB_ANY, VERB_ANY, 0, verb_domain },
{ "llmnr", VERB_ANY, 3, 0, verb_llmnr },
{ "mdns", VERB_ANY, 3, 0, verb_mdns },
{ "privatedns", VERB_ANY, 3, 0, verb_private_dns },
{ "dnssec", VERB_ANY, 3, 0, verb_dnssec },
{ "nta", VERB_ANY, VERB_ANY, 0, verb_nta },
{ "revert", 2, 2, 0, verb_revert_link },
@ -2969,6 +3050,12 @@ static int compat_main(int argc, char *argv[], sd_bus *bus) {
return r;
}
if (arg_set_private_dns) {
r = translate("privatedns", arg_ifname, 1, (char **) &arg_set_private_dns, bus);
if (r < 0)
return r;
}
if (arg_set_dnssec) {
r = translate("dnssec", arg_ifname, 1, (char **) &arg_set_dnssec, bus);
if (r < 0)

7
src/resolve/resolved-conf.c
View File

@ -396,6 +396,13 @@ int manager_parse_config_file(Manager *m) {
m->dnssec_mode = DNSSEC_NO;
}
#endif
#if ! HAVE_GNUTLS
if (m->private_dns_mode != PRIVATE_DNS_NO) {
log_warning("Private DNS option cannot be set to opportunistic when systemd-resolved is built without gnutls support. Turning off private DNS support.");
m->private_dns_mode = PRIVATE_DNS_NO;
}
#endif
return 0;
}

25
src/resolve/resolved-dns-packet.c
View File

@ -2333,6 +2333,31 @@ int dns_packet_is_reply_for(DnsPacket *p, const DnsResourceKey *key) {
return dns_resource_key_equal(p->question->keys[0], key);
}
static void dns_packet_hash_func(const void *p, struct siphash *state) {
const DnsPacket *s = p;
assert(s);
siphash24_compress(&s->size, sizeof(s->size), state);
siphash24_compress(DNS_PACKET_DATA((DnsPacket*) s), s->size, state);
}
static int dns_packet_compare_func(const void *a, const void *b) {
const DnsPacket *x = a, *y = b;
if (x->size < y->size)
return -1;
if (x->size > y->size)
return 1;
return memcmp(DNS_PACKET_DATA((DnsPacket*) x), DNS_PACKET_DATA((DnsPacket*) y), x->size);
}
const struct hash_ops dns_packet_hash_ops = {
.hash = dns_packet_hash_func,
.compare = dns_packet_compare_func
};
static const char* const dns_rcode_table[_DNS_RCODE_MAX_DEFINED] = {
[DNS_RCODE_SUCCESS] = "SUCCESS",
[DNS_RCODE_FORMERR] = "FORMERR",

2
src/resolve/resolved-dns-packet.h
View File

@ -270,6 +270,8 @@ DnsProtocol dns_protocol_from_string(const char *s) _pure_;
#define MDNS_MULTICAST_IPV4_ADDRESS ((struct in_addr) { .s_addr = htobe32(224U << 24 | 251U) })
#define MDNS_MULTICAST_IPV6_ADDRESS ((struct in6_addr) { .s6_addr = { 0xFF, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xfb } })
extern const struct hash_ops dns_packet_hash_ops;
static inline uint64_t SD_RESOLVED_FLAGS_MAKE(DnsProtocol protocol, int family, bool authenticated) {
uint64_t f;

37
src/resolve/resolved-dns-scope.c
View File

@ -52,12 +52,18 @@ int dns_scope_new(Manager *m, DnsScope **ret, Link *l, DnsProtocol protocol, int
* not update it from the on, even if the setting
* changes. */
if (l)
if (l) {
s->dnssec_mode = link_get_dnssec_mode(l);
else
s->private_dns_mode = link_get_private_dns_mode(l);
} else {
s->dnssec_mode = manager_get_dnssec_mode(m);
} else
s->private_dns_mode = manager_get_private_dns_mode(m);
}
} else {
s->dnssec_mode = DNSSEC_NO;
s->private_dns_mode = PRIVATE_DNS_NO;
}
LIST_PREPEND(scopes, m->dns_scopes, s);
@ -306,10 +312,11 @@ static int dns_scope_socket(
int family,
const union in_addr_union *address,
DnsServer *server,
uint16_t port) {
uint16_t port,
union sockaddr_union *ret_socket_address) {
_cleanup_close_ int fd = -1;
union sockaddr_union sa = {};
union sockaddr_union sa;
socklen_t salen;
static const int one = 1;
int r, ifindex;
@ -392,19 +399,27 @@ static int dns_scope_socket(
}
}
r = connect(fd, &sa.sa, salen);
if (r < 0 && errno != EINPROGRESS)
return -errno;
if (ret_socket_address)
*ret_socket_address = sa;
else {
r = connect(fd, &sa.sa, salen);
if (r < 0 && errno != EINPROGRESS)
return -errno;
}
return TAKE_FD(fd);
}
int dns_scope_socket_udp(DnsScope *s, DnsServer *server, uint16_t port) {
return dns_scope_socket(s, SOCK_DGRAM, AF_UNSPEC, NULL, server, port);
return dns_scope_socket(s, SOCK_DGRAM, AF_UNSPEC, NULL, server, port, NULL);
}
int dns_scope_socket_tcp(DnsScope *s, int family, const union in_addr_union *address, DnsServer *server, uint16_t port) {
return dns_scope_socket(s, SOCK_STREAM, family, address, server, port);
int dns_scope_socket_tcp(DnsScope *s, int family, const union in_addr_union *address, DnsServer *server, uint16_t port, union sockaddr_union *ret_socket_address) {
/* If ret_socket_address is not NULL, the caller is responisble
* for calling connect() or sendmsg(). This is required by TCP
* Fast Open, to be able to send the initial SYN packet along
* with the first data packet. */
return dns_scope_socket(s, SOCK_STREAM, family, address, server, port, ret_socket_address);
}
DnsScopeMatch dns_scope_good_domain(DnsScope *s, int ifindex, uint64_t flags, const char *domain) {

3
src/resolve/resolved-dns-scope.h
View File

@ -35,6 +35,7 @@ struct DnsScope {
DnsProtocol protocol;
int family;
DnssecMode dnssec_mode;
PrivateDnsMode private_dns_mode;
Link *link;
@ -75,7 +76,7 @@ void dns_scope_packet_received(DnsScope *s, usec_t rtt);
void dns_scope_packet_lost(DnsScope *s, usec_t usec);
int dns_scope_emit_udp(DnsScope *s, int fd, DnsPacket *p);
int dns_scope_socket_tcp(DnsScope *s, int family, const union in_addr_union *address, DnsServer *server, uint16_t port);
int dns_scope_socket_tcp(DnsScope *s, int family, const union in_addr_union *address, DnsServer *server, uint16_t port, union sockaddr_union *ret_socket_address);
int dns_scope_socket_udp(DnsScope *s, DnsServer *server, uint16_t port);
DnsScopeMatch dns_scope_good_domain(DnsScope *s, int ifindex, uint64_t flags, const char *domain);

98
src/resolve/resolved-dns-server.c
View File

@ -89,6 +89,11 @@ int dns_server_new(
s->linked = true;
#if HAVE_GNUTLS
/* Do not verify cerificate */
gnutls_certificate_allocate_credentials(&s->tls_cert_cred);
#endif
/* A new DNS server that isn't fallback is added and the one
* we used so far was a fallback one? Then let's try to pick
* the new one */
@ -123,6 +128,16 @@ DnsServer* dns_server_unref(DnsServer *s) {
if (s->n_ref > 0)
return NULL;
dns_stream_unref(s->stream);
#if HAVE_GNUTLS
if (s->tls_cert_cred)
gnutls_certificate_free_credentials(s->tls_cert_cred);
if (s->tls_session_data.data)
gnutls_free(s->tls_session_data.data);
#endif
free(s->server_string);
return mfree(s);
}
@ -234,6 +249,7 @@ static void dns_server_reset_counters(DnsServer *s) {
s->n_failed_udp = 0;
s->n_failed_tcp = 0;
s->n_failed_tls = 0;
s->packet_truncated = false;
s->verified_usec = 0;
@ -255,29 +271,32 @@ void dns_server_packet_received(DnsServer *s, int protocol, DnsServerFeatureLeve
if (protocol == IPPROTO_UDP) {
if (s->possible_feature_level == level)
s->n_failed_udp = 0;
/* If the RRSIG data is missing, then we can only validate EDNS0 at max */
if (s->packet_rrsig_missing && level >= DNS_SERVER_FEATURE_LEVEL_DO)
level = DNS_SERVER_FEATURE_LEVEL_DO - 1;
/* If the OPT RR got lost, then we can only validate UDP at max */
if (s->packet_bad_opt && level >= DNS_SERVER_FEATURE_LEVEL_EDNS0)
level = DNS_SERVER_FEATURE_LEVEL_EDNS0 - 1;
/* Even if we successfully receive a reply to a request announcing support for large packets,
that does not mean we can necessarily receive large packets. */
if (level == DNS_SERVER_FEATURE_LEVEL_LARGE)
level = DNS_SERVER_FEATURE_LEVEL_LARGE - 1;
} else if (protocol == IPPROTO_TCP) {
if (DNS_SERVER_FEATURE_LEVEL_IS_TLS(level)) {
if (s->possible_feature_level == level)
s->n_failed_tls = 0;
} else {
if (s->possible_feature_level == level)
s->n_failed_tcp = 0;
if (s->possible_feature_level == level)
s->n_failed_tcp = 0;
/* Successful TCP connections are only useful to verify the TCP feature level. */
level = DNS_SERVER_FEATURE_LEVEL_TCP;
/* Successful TCP connections are only useful to verify the TCP feature level. */
level = DNS_SERVER_FEATURE_LEVEL_TCP;
}
}
/* If the RRSIG data is missing, then we can only validate EDNS0 at max */
if (s->packet_rrsig_missing && level >= DNS_SERVER_FEATURE_LEVEL_DO)
level = DNS_SERVER_FEATURE_LEVEL_IS_TLS(level) ? DNS_SERVER_FEATURE_LEVEL_TLS_PLAIN : DNS_SERVER_FEATURE_LEVEL_EDNS0;
/* If the OPT RR got lost, then we can only validate UDP at max */
if (s->packet_bad_opt && level >= DNS_SERVER_FEATURE_LEVEL_EDNS0)
level = DNS_SERVER_FEATURE_LEVEL_EDNS0 - 1;
/* Even if we successfully receive a reply to a request announcing support for large packets,
that does not mean we can necessarily receive large packets. */
if (level == DNS_SERVER_FEATURE_LEVEL_LARGE)
level = DNS_SERVER_FEATURE_LEVEL_LARGE - 1;
dns_server_verified(s, level);
/* Remember the size of the largest UDP packet we received from a server,
@ -302,8 +321,12 @@ void dns_server_packet_lost(DnsServer *s, int protocol, DnsServerFeatureLevel le
if (s->possible_feature_level == level) {
if (protocol == IPPROTO_UDP)
s->n_failed_udp++;
else if (protocol == IPPROTO_TCP)
s->n_failed_tcp++;
else if (protocol == IPPROTO_TCP) {
if (DNS_SERVER_FEATURE_LEVEL_IS_TLS(level))
s->n_failed_tls++;
else
s->n_failed_tcp++;
}
}
if (s->resend_timeout > usec)
@ -331,7 +354,7 @@ void dns_server_packet_rrsig_missing(DnsServer *s, DnsServerFeatureLevel level)
/* If the RRSIG RRs are missing, we have to downgrade what we previously verified */
if (s->verified_feature_level >= DNS_SERVER_FEATURE_LEVEL_DO)
s->verified_feature_level = DNS_SERVER_FEATURE_LEVEL_DO-1;
s->verified_feature_level = DNS_SERVER_FEATURE_LEVEL_IS_TLS(level) ? DNS_SERVER_FEATURE_LEVEL_TLS_PLAIN : DNS_SERVER_FEATURE_LEVEL_EDNS0;
s->packet_rrsig_missing = true;
}
@ -393,9 +416,14 @@ DnsServerFeatureLevel dns_server_possible_feature_level(DnsServer *s) {
/* Determine the best feature level we care about. If DNSSEC mode is off there's no point in using anything
* better than EDNS0, hence don't even try. */
best = dns_server_get_dnssec_mode(s) == DNSSEC_NO ?
DNS_SERVER_FEATURE_LEVEL_EDNS0 :
DNS_SERVER_FEATURE_LEVEL_BEST;
if (dns_server_get_dnssec_mode(s) != DNSSEC_NO)
best = dns_server_get_private_dns_mode(s) == PRIVATE_DNS_NO ?
DNS_SERVER_FEATURE_LEVEL_LARGE :
DNS_SERVER_FEATURE_LEVEL_TLS_DO;
else
best = dns_server_get_private_dns_mode(s) == PRIVATE_DNS_NO ?
DNS_SERVER_FEATURE_LEVEL_EDNS0 :
DNS_SERVER_FEATURE_LEVEL_TLS_PLAIN;
/* Clamp the feature level the highest level we care about. The DNSSEC mode might have changed since the last
* time, hence let's downgrade if we are still at a higher level. */
@ -429,7 +457,14 @@ DnsServerFeatureLevel dns_server_possible_feature_level(DnsServer *s) {
* work. Upgrade back to UDP again. */
log_debug("Reached maximum number of failed TCP connection attempts, trying UDP again...");
s->possible_feature_level = DNS_SERVER_FEATURE_LEVEL_UDP;
} else if (s->n_failed_tls > 0 &&
DNS_SERVER_FEATURE_LEVEL_IS_TLS(s->possible_feature_level)) {
/* We tried to connect using DNS-over-TLS, and it didn't work. Downgrade to plaintext UDP
* if we don't require DNS-over-TLS */
log_debug("Server doesn't support seem to support DNS-over-TLS, downgrading protocol...");
s->possible_feature_level--;
} else if (s->packet_bad_opt &&
s->possible_feature_level >= DNS_SERVER_FEATURE_LEVEL_EDNS0) {
@ -450,7 +485,7 @@ DnsServerFeatureLevel dns_server_possible_feature_level(DnsServer *s) {
* not. */
log_debug("Detected server responses lack RRSIG records, downgrading feature level...");
s->possible_feature_level = DNS_SERVER_FEATURE_LEVEL_EDNS0;
s->possible_feature_level = DNS_SERVER_FEATURE_LEVEL_IS_TLS(s->possible_feature_level) ? DNS_SERVER_FEATURE_LEVEL_TLS_PLAIN : DNS_SERVER_FEATURE_LEVEL_EDNS0;
} else if (s->n_failed_udp >= DNS_SERVER_FEATURE_RETRY_ATTEMPTS &&
s->possible_feature_level >= (dns_server_get_dnssec_mode(s) == DNSSEC_YES ? DNS_SERVER_FEATURE_LEVEL_LARGE : DNS_SERVER_FEATURE_LEVEL_UDP)) {
@ -793,6 +828,15 @@ DnssecMode dns_server_get_dnssec_mode(DnsServer *s) {
return manager_get_dnssec_mode(s->manager);
}
PrivateDnsMode dns_server_get_private_dns_mode(DnsServer *s) {
assert(s);
if (s->link)
return link_get_private_dns_mode(s->link);
return manager_get_private_dns_mode(s->manager);
}
void dns_server_flush_cache(DnsServer *s) {
DnsServer *current;
DnsScope *scope;
@ -902,7 +946,9 @@ static const char* const dns_server_feature_level_table[_DNS_SERVER_FEATURE_LEVE
[DNS_SERVER_FEATURE_LEVEL_TCP] = "TCP",
[DNS_SERVER_FEATURE_LEVEL_UDP] = "UDP",
[DNS_SERVER_FEATURE_LEVEL_EDNS0] = "UDP+EDNS0",
[DNS_SERVER_FEATURE_LEVEL_TLS_PLAIN] = "TLS+EDNS0",
[DNS_SERVER_FEATURE_LEVEL_DO] = "UDP+EDNS0+DO",
[DNS_SERVER_FEATURE_LEVEL_LARGE] = "UDP+EDNS0+DO+LARGE",
[DNS_SERVER_FEATURE_LEVEL_TLS_DO] = "TLS+EDNS0+D0",
};
DEFINE_STRING_TABLE_LOOKUP(dns_server_feature_level, DnsServerFeatureLevel);

15
src/resolve/resolved-dns-server.h
View File

@ -9,6 +9,10 @@
#include "in-addr-util.h"
#if HAVE_GNUTLS
#include <gnutls/gnutls.h>
#endif
typedef struct DnsServer DnsServer;
typedef enum DnsServerType {
@ -25,14 +29,17 @@ typedef enum DnsServerFeatureLevel {
DNS_SERVER_FEATURE_LEVEL_TCP,
DNS_SERVER_FEATURE_LEVEL_UDP,
DNS_SERVER_FEATURE_LEVEL_EDNS0,
DNS_SERVER_FEATURE_LEVEL_TLS_PLAIN,
DNS_SERVER_FEATURE_LEVEL_DO,
DNS_SERVER_FEATURE_LEVEL_LARGE,
DNS_SERVER_FEATURE_LEVEL_TLS_DO,
_DNS_SERVER_FEATURE_LEVEL_MAX,
_DNS_SERVER_FEATURE_LEVEL_INVALID = -1
} DnsServerFeatureLevel;
#define DNS_SERVER_FEATURE_LEVEL_WORST 0
#define DNS_SERVER_FEATURE_LEVEL_BEST (_DNS_SERVER_FEATURE_LEVEL_MAX - 1)
#define DNS_SERVER_FEATURE_LEVEL_IS_TLS(x) IN_SET(x, DNS_SERVER_FEATURE_LEVEL_TLS_PLAIN, DNS_SERVER_FEATURE_LEVEL_TLS_DO)
const char* dns_server_feature_level_to_string(int i) _const_;
int dns_server_feature_level_from_string(const char *s) _pure_;
@ -53,6 +60,12 @@ struct DnsServer {
int ifindex; /* for IPv6 link-local DNS servers */
char *server_string;
DnsStream *stream;
#if HAVE_GNUTLS
gnutls_certificate_credentials_t tls_cert_cred;
gnutls_datum_t tls_session_data;
#endif
usec_t resend_timeout;
usec_t max_rtt;
@ -64,6 +77,7 @@ struct DnsServer {
unsigned n_failed_udp;
unsigned n_failed_tcp;
unsigned n_failed_tls;
bool packet_truncated:1;
bool packet_bad_opt:1;
@ -133,6 +147,7 @@ void manager_next_dns_server(Manager *m);
bool dns_server_address_valid(int family, const union in_addr_union *sa);
DnssecMode dns_server_get_dnssec_mode(DnsServer *s);
PrivateDnsMode dns_server_get_private_dns_mode(DnsServer *s);
DEFINE_TRIVIAL_CLEANUP_FUNC(DnsServer*, dns_server_unref);

251
src/resolve/resolved-dns-stream.c
View File

@ -16,6 +16,8 @@
#define DNS_STREAM_TIMEOUT_USEC (10 * USEC_PER_SEC)
#define DNS_STREAMS_MAX 128
#define WRITE_TLS_DATA 1
static void dns_stream_stop(DnsStream *s) {
assert(s);
@ -31,6 +33,13 @@ static int dns_stream_update_io(DnsStream *s) {
if (s->write_packet && s->n_written < sizeof(s->write_size) + s->write_packet->size)
f |= EPOLLOUT;
else if (!ordered_set_isempty(s->write_queue)) {
dns_packet_unref(s->write_packet);
s->write_packet = ordered_set_steal_first(s->write_queue);
s->write_size = htobe16(s->write_packet->size);
s->n_written = 0;
f |= EPOLLOUT;
}
if (!s->read_packet || s->n_read < sizeof(s->read_size) + s->read_packet->size)
f |= EPOLLIN;
@ -40,7 +49,19 @@ static int dns_stream_update_io(DnsStream *s) {
static int dns_stream_complete(DnsStream *s, int error) {
assert(s);
dns_stream_stop(s);
#if HAVE_GNUTLS
if (s->tls_session && IN_SET(error, ETIMEDOUT, 0)) {
int r;
r = gnutls_bye(s->tls_session, GNUTLS_SHUT_RDWR);
if (r == GNUTLS_E_AGAIN && !s->tls_bye) {
dns_stream_ref(s); /* keep reference for closing TLS session */
s->tls_bye = true;
} else
dns_stream_stop(s);
} else
#endif
dns_stream_stop(s);
if (s->complete)
s->complete(s, error);
@ -175,6 +196,114 @@ static int dns_stream_identify(DnsStream *s) {
return 0;
}
static ssize_t dns_stream_writev(DnsStream *s, const struct iovec *iov, size_t iovcnt, int flags) {
ssize_t r;
assert(s);
assert(iov);
#if HAVE_GNUTLS
if (s->tls_session && !(flags & WRITE_TLS_DATA)) {
ssize_t ss;
size_t i;
r = 0;
for (i = 0; i < iovcnt; i++) {
ss = gnutls_record_send(s->tls_session, iov[i].iov_base, iov[i].iov_len);
if (ss < 0) {
switch(ss) {
case GNUTLS_E_INTERRUPTED:
return -EINTR;
case GNUTLS_E_AGAIN:
return -EAGAIN;
default:
log_debug("Failed to invoke gnutls_record_send: %s", gnutls_strerror(ss));
return -EIO;
}
}
r += ss;
if (ss != (ssize_t) iov[i].iov_len)
continue;
}
} else
#endif
if (s->tfo_salen > 0) {
struct msghdr hdr = {
.msg_iov = (struct iovec*) iov,
.msg_iovlen = iovcnt,
.msg_name = &s->tfo_address.sa,
.msg_namelen = s->tfo_salen
};
r = sendmsg(s->fd, &hdr, MSG_FASTOPEN);
if (r < 0) {
if (errno == EOPNOTSUPP) {
s->tfo_salen = 0;
r = connect(s->fd, &s->tfo_address.sa, s->tfo_salen);
if (r < 0)
return -errno;
r = -EAGAIN;
} else if (errno == EINPROGRESS)
r = -EAGAIN;
} else
s->tfo_salen = 0; /* connection is made */
} else
r = writev(s->fd, iov, iovcnt);
return r;
}
static ssize_t dns_stream_read(DnsStream *s, void *buf, size_t count) {
ssize_t ss;
#if HAVE_GNUTLS
if (s->tls_session) {
ss = gnutls_record_recv(s->tls_session, buf, count);
if (ss < 0) {
switch(ss) {
case GNUTLS_E_INTERRUPTED:
return -EINTR;
case GNUTLS_E_AGAIN:
return -EAGAIN;
default:
log_debug("Failed to invoke gnutls_record_send: %s", gnutls_strerror(ss));
return -EIO;
}
} else if (s->on_connection) {
int r;
r = s->on_connection(s);
s->on_connection = NULL; /* only call once */
if (r < 0)
return r;
}
} else
#endif
ss = read(s->fd, buf, count);
return ss;
}
#if HAVE_GNUTLS
static ssize_t dns_stream_tls_writev(gnutls_transport_ptr_t p, const giovec_t * iov, int iovcnt) {
int r;
assert(p);
r = dns_stream_writev((DnsStream*) p, (struct iovec*) iov, iovcnt, WRITE_TLS_DATA);
if (r < 0) {
errno = -r;
return -1;
}
return r;
}
#endif
static int on_stream_timeout(sd_event_source *es, usec_t usec, void *userdata) {
DnsStream *s = userdata;
@ -189,9 +318,46 @@ static int on_stream_io(sd_event_source *es, int fd, uint32_t revents, void *use
assert(s);
r = dns_stream_identify(s);
if (r < 0)
return dns_stream_complete(s, -r);
#if HAVE_GNUTLS
if (s->tls_bye) {
assert(s->tls_session);
r = gnutls_bye(s->tls_session, GNUTLS_SHUT_RDWR);
if (r != GNUTLS_E_AGAIN) {
s->tls_bye = false;
dns_stream_unref(s);
}
return 0;
}
if (s->tls_handshake < 0) {
assert(s->tls_session);
s->tls_handshake = gnutls_handshake(s->tls_session);
if (s->tls_handshake >= 0) {
if (s->on_connection && !(gnutls_session_get_flags(s->tls_session) & GNUTLS_SFLAGS_FALSE_START)) {
r = s->on_connection(s);
s->on_connection = NULL; /* only call once */
if (r < 0)
return r;
}
} else {
if (gnutls_error_is_fatal(s->tls_handshake))
return dns_stream_complete(s, ECONNREFUSED);
else
return 0;
}
}
#endif
/* only identify after connecting */
if (s->tfo_salen == 0) {
r = dns_stream_identify(s);
if (r < 0)
return dns_stream_complete(s, -r);
}
if ((revents & EPOLLOUT) &&
s->write_packet &&
@ -207,7 +373,7 @@ static int on_stream_io(sd_event_source *es, int fd, uint32_t revents, void *use
IOVEC_INCREMENT(iov, 2, s->n_written);
ss = writev(fd, iov, 2);
ss = dns_stream_writev(s, iov, 2, 0);
if (ss < 0) {
if (!IN_SET(errno, EINTR, EAGAIN))
return dns_stream_complete(s, errno);
@ -229,7 +395,7 @@ static int on_stream_io(sd_event_source *es, int fd, uint32_t revents, void *use
if (s->n_read < sizeof(s->read_size)) {
ssize_t ss;
ss = read(fd, (uint8_t*) &s->read_size + s->n_read, sizeof(s->read_size) - s->n_read);
ss = dns_stream_read(s, (uint8_t*) &s->read_size + s->n_read, sizeof(s->read_size) - s->n_read);
if (ss < 0) {
if (!IN_SET(errno, EINTR, EAGAIN))
return dns_stream_complete(s, errno);
@ -277,7 +443,7 @@ static int on_stream_io(sd_event_source *es, int fd, uint32_t revents, void *use
}
}
ss = read(fd,
ss = dns_stream_read(s,
(uint8_t*) DNS_PACKET_DATA(s->read_packet) + s->n_read - sizeof(s->read_size),
sizeof(s->read_size) + be16toh(s->read_size) - s->n_read);
if (ss < 0) {
@ -291,15 +457,18 @@ static int on_stream_io(sd_event_source *es, int fd, uint32_t revents, void *use
/* Are we done? If so, disable the event source for EPOLLIN */
if (s->n_read >= sizeof(s->read_size) + be16toh(s->read_size)) {
r = dns_stream_update_io(s);
if (r < 0)
return dns_stream_complete(s, -r);
/* If there's a packet handler
* installed, call that. Note that
* this is optional... */
if (s->on_packet)
return s->on_packet(s);
if (s->on_packet) {
r = s->on_packet(s);
if (r < 0)
return r;
}
r = dns_stream_update_io(s);
if (r < 0)
return dns_stream_complete(s, -r);
}
}
}
@ -312,6 +481,9 @@ static int on_stream_io(sd_event_source *es, int fd, uint32_t revents, void *use
}
DnsStream *dns_stream_unref(DnsStream *s) {
DnsPacket *p;
Iterator i;
if (!s)
return NULL;
@ -323,19 +495,31 @@ DnsStream *dns_stream_unref(DnsStream *s) {
dns_stream_stop(s);
if (s->server && s->server->stream == s)
s->server->stream = NULL;
if (s->manager) {
LIST_REMOVE(streams, s->manager->dns_streams, s);
s->manager->n_dns_streams--;
}
#if HAVE_GNUTLS
if (s->tls_session)
gnutls_deinit(s->tls_session);
#endif
ORDERED_SET_FOREACH(p, s->write_queue, i)
dns_packet_unref(ordered_set_remove(s->write_queue, p));
dns_packet_unref(s->write_packet);
dns_packet_unref(s->read_packet);
dns_server_unref(s->server);
ordered_set_free(s->write_queue);
return mfree(s);
}
DEFINE_TRIVIAL_CLEANUP_FUNC(DnsStream*, dns_stream_unref);
DnsStream *dns_stream_ref(DnsStream *s) {
if (!s)
return NULL;
@ -346,7 +530,7 @@ DnsStream *dns_stream_ref(DnsStream *s) {
return s;
}
int dns_stream_new(Manager *m, DnsStream **ret, DnsProtocol protocol, int fd) {
int dns_stream_new(Manager *m, DnsStream **ret, DnsProtocol protocol, int fd, const union sockaddr_union *tfo_address) {
_cleanup_(dns_stream_unrefp) DnsStream *s = NULL;
int r;
@ -360,6 +544,10 @@ int dns_stream_new(Manager *m, DnsStream **ret, DnsProtocol protocol, int fd) {
if (!s)
return -ENOMEM;
r = ordered_set_ensure_allocated(&s->write_queue, &dns_packet_hash_ops);
if (r < 0)
return r;
s->n_ref = 1;
s->fd = -1;
s->protocol = protocol;
@ -384,6 +572,11 @@ int dns_stream_new(Manager *m, DnsStream **ret, DnsProtocol protocol, int fd) {
LIST_PREPEND(streams, m->dns_streams, s);
s->manager = m;
s->fd = fd;
if (tfo_address) {
s->tfo_address = *tfo_address;
s->tfo_salen = tfo_address->sa.sa_family == AF_INET6 ? sizeof(tfo_address->in6) : sizeof(tfo_address->in);
}
m->n_dns_streams++;
*ret = TAKE_PTR(s);
@ -391,15 +584,31 @@ int dns_stream_new(Manager *m, DnsStream **ret, DnsProtocol protocol, int fd) {
return 0;
}
#if HAVE_GNUTLS
int dns_stream_connect_tls(DnsStream *s, gnutls_session_t tls_session) {
gnutls_transport_set_ptr2(tls_session, (gnutls_transport_ptr_t) (long) s->fd, s);
gnutls_transport_set_vec_push_function(tls_session, &dns_stream_tls_writev);
s->encrypted = true;
s->tls_session = tls_session;
s->tls_handshake = gnutls_handshake(tls_session);
if (s->tls_handshake < 0 && gnutls_error_is_fatal(s->tls_handshake))
return -ECONNREFUSED;
return 0;
}
#endif
int dns_stream_write_packet(DnsStream *s, DnsPacket *p) {
int r;
assert(s);
if (s->write_packet)
return -EBUSY;
r = ordered_set_put(s->write_queue, p);
if (r < 0)
return r;
s->write_packet = dns_packet_ref(p);
s->write_size = htobe16(p->size);
s->n_written = 0;
dns_packet_ref(p);
return dns_stream_update_io(s);
}

29
src/resolve/resolved-dns-stream.h
View File

@ -15,6 +15,10 @@ typedef struct DnsStream DnsStream;
#include "resolved-dns-transaction.h"
#include "resolved-manager.h"
#if HAVE_GNUTLS
#include <gnutls/gnutls.h>
#endif
/* Streams are used by three subsystems:
*
* 1. The normal transaction logic when doing a DNS or LLMNR lookup via TCP
@ -37,26 +41,47 @@ struct DnsStream {
uint32_t ttl;
bool identified;
/* only when using TCP fast open */
union sockaddr_union tfo_address;
socklen_t tfo_salen;
#if HAVE_GNUTLS
gnutls_session_t tls_session;
int tls_handshake;
bool tls_bye;
#endif
sd_event_source *io_event_source;
sd_event_source *timeout_event_source;
be16_t write_size, read_size;
DnsPacket *write_packet, *read_packet;
size_t n_written, n_read;
OrderedSet *write_queue;
int (*on_connection)(DnsStream *s);
int (*on_packet)(DnsStream *s);
int (*complete)(DnsStream *s, int error);
DnsTransaction *transaction; /* when used by the transaction logic */
LIST_HEAD(DnsTransaction, transactions); /* when used by the transaction logic */
DnsServer *server; /* when used by the transaction logic */
DnsQuery *query; /* when used by the DNS stub logic */
/* used when DNS-over-TLS is enabled */
bool encrypted:1;
LIST_FIELDS(DnsStream, streams);
};
int dns_stream_new(Manager *m, DnsStream **s, DnsProtocol protocol, int fd);
int dns_stream_new(Manager *m, DnsStream **s, DnsProtocol protocol, int fd, const union sockaddr_union *tfo_address);
#if HAVE_GNUTLS
int dns_stream_connect_tls(DnsStream *s, gnutls_session_t tls_session);
#endif
DnsStream *dns_stream_unref(DnsStream *s);
DnsStream *dns_stream_ref(DnsStream *s);
DEFINE_TRIVIAL_CLEANUP_FUNC(DnsStream*, dns_stream_unref);
int dns_stream_write_packet(DnsStream *s, DnsPacket *p);
static inline bool DNS_STREAM_QUEUED(DnsStream *s) {

2
src/resolve/resolved-dns-stub.c
View File

@ -469,7 +469,7 @@ static int on_dns_stub_stream(sd_event_source *s, int fd, uint32_t revents, void
return -errno;
}
r = dns_stream_new(m, &stream, DNS_PROTOCOL_DNS, cfd);
r = dns_stream_new(m, &stream, DNS_PROTOCOL_DNS, cfd, NULL);
if (r < 0) {
safe_close(cfd);
return r;

218
src/resolve/resolved-dns-transaction.c
View File

@ -18,6 +18,10 @@
#include "resolved-llmnr.h"
#include "string-table.h"
#if HAVE_GNUTLS
#include <gnutls/socket.h>
#endif
#define TRANSACTIONS_MAX 4096
#define TRANSACTION_TCP_TIMEOUT_USEC (10U*USEC_PER_SEC)
@ -51,9 +55,11 @@ static void dns_transaction_close_connection(DnsTransaction *t) {
if (t->stream) {
/* Let's detach the stream from our transaction, in case something else keeps a reference to it. */
t->stream->complete = NULL;
t->stream->on_packet = NULL;
t->stream->transaction = NULL;
LIST_REMOVE(transactions_by_stream, t->stream->transactions, t);
/* Remove packet in case it's still in the queue */
dns_packet_unref(ordered_set_remove(t->stream->write_queue, t->sent));
t->stream = dns_stream_unref(t->stream);
}
@ -448,42 +454,31 @@ static int dns_transaction_maybe_restart(DnsTransaction *t) {
return 1;
}
static int on_stream_complete(DnsStream *s, int error) {
_cleanup_(dns_packet_unrefp) DnsPacket *p = NULL;
DnsTransaction *t;
assert(s);
assert(s->transaction);
/* Copy the data we care about out of the stream before we
* destroy it. */
t = s->transaction;
p = dns_packet_ref(s->read_packet);
static void on_transaction_stream_error(DnsTransaction *t, int error) {
assert(t);
dns_transaction_close_connection(t);
if (ERRNO_IS_DISCONNECT(error)) {
usec_t usec;
if (t->scope->protocol == DNS_PROTOCOL_LLMNR) {
/* If the LLMNR/TCP connection failed, the host doesn't support LLMNR, and we cannot answer the
* question on this scope. */
dns_transaction_complete(t, DNS_TRANSACTION_NOT_FOUND);
return 0;
}
log_debug_errno(error, "Connection failure for DNS TCP stream: %m");
assert_se(sd_event_now(t->scope->manager->event, clock_boottime_or_monotonic(), &usec) >= 0);
dns_server_packet_lost(t->server, IPPROTO_TCP, t->current_feature_level, usec - t->start_usec);
dns_transaction_retry(t, true);
return 0;
}
if (error != 0) {
t->answer_errno = error;
dns_transaction_complete(t, DNS_TRANSACTION_ERRNO);
return 0;
}
}
static int dns_transaction_on_stream_packet(DnsTransaction *t, DnsPacket *p) {
assert(t);
assert(p);
dns_transaction_close_connection(t);
if (dns_packet_validate_reply(p) <= 0) {
log_debug("Invalid TCP reply packet.");
@ -508,9 +503,83 @@ static int on_stream_complete(DnsStream *s, int error) {
return 0;
}
static int dns_transaction_open_tcp(DnsTransaction *t) {
static int on_stream_connection(DnsStream *s) {
#if HAVE_GNUTLS
/* Store TLS Ticket for faster succesive TLS handshakes */
if (s->tls_session && s->server) {
if (s->server->tls_session_data.data)
gnutls_free(s->server->tls_session_data.data);
gnutls_session_get_data2(s->tls_session, &s->server->tls_session_data);
}
#endif
return 0;
}
static int on_stream_complete(DnsStream *s, int error) {
DnsTransaction *t, *n;
int r = 0;
/* Do not let new transactions use this stream */
if (s->server && s->server->stream == s)
s->server->stream = dns_stream_unref(s->server->stream);
if (ERRNO_IS_DISCONNECT(error) && s->protocol != DNS_PROTOCOL_LLMNR) {
usec_t usec;
log_debug_errno(error, "Connection failure for DNS TCP stream: %m");
if (s->transactions) {
t = s->transactions;
assert_se(sd_event_now(t->scope->manager->event, clock_boottime_or_monotonic(), &usec) >= 0);
dns_server_packet_lost(t->server, IPPROTO_UDP, t->current_feature_level, usec - t->start_usec);
}
}
LIST_FOREACH_SAFE(transactions_by_stream, t, n, s->transactions)
if (error != 0)
on_transaction_stream_error(t, error);
else if (DNS_PACKET_ID(s->read_packet) == t->id)
/* As each transaction have a unique id the return code is only set once */
r = dns_transaction_on_stream_packet(t, s->read_packet);
return r;
}
static int dns_stream_on_packet(DnsStream *s) {
_cleanup_(dns_packet_unrefp) DnsPacket *p = NULL;
int r = 0;
DnsTransaction *t;
/* Take ownership of packet to be able to receive new packets */
p = TAKE_PTR(s->read_packet);
s->n_read = 0;
t = hashmap_get(s->manager->dns_transactions, UINT_TO_PTR(DNS_PACKET_ID(p)));
/* Ignore incorrect transaction id as transaction can have been canceled */
if (t)
r = dns_transaction_on_stream_packet(t, p);
else {
if (dns_packet_validate_reply(p) <= 0) {
log_debug("Invalid TCP reply packet.");
on_stream_complete(s, 0);
}
return 0;
}
return r;
}
static int dns_transaction_emit_tcp(DnsTransaction *t) {
_cleanup_close_ int fd = -1;
_cleanup_(dns_stream_unrefp) DnsStream *s = NULL;
union sockaddr_union sa;
int r;
#if HAVE_GNUTLS
gnutls_session_t gs;
#endif
assert(t);
@ -530,13 +599,17 @@ static int dns_transaction_open_tcp(DnsTransaction *t) {
if (r < 0)
return r;
fd = dns_scope_socket_tcp(t->scope, AF_UNSPEC, NULL, t->server, 53);
if (t->server->stream && (DNS_SERVER_FEATURE_LEVEL_IS_TLS(t->current_feature_level) == t->server->stream->encrypted))
s = dns_stream_ref(t->server->stream);
else
fd = dns_scope_socket_tcp(t->scope, AF_UNSPEC, NULL, t->server, DNS_SERVER_FEATURE_LEVEL_IS_TLS(t->current_feature_level) ? 853 : 53, &sa);
break;
case DNS_PROTOCOL_LLMNR:
/* When we already received a reply to this (but it was truncated), send to its sender address */
if (t->received)
fd = dns_scope_socket_tcp(t->scope, t->received->family, &t->received->sender, NULL, t->received->sender_port);
fd = dns_scope_socket_tcp(t->scope, t->received->family, &t->received->sender, NULL, t->received->sender_port, &sa);
else {
union in_addr_union address;
int family = AF_UNSPEC;
@ -553,7 +626,7 @@ static int dns_transaction_open_tcp(DnsTransaction *t) {
if (family != t->scope->family)
return -ESRCH;
fd = dns_scope_socket_tcp(t->scope, family, &address, NULL, LLMNR_PORT);
fd = dns_scope_socket_tcp(t->scope, family, &address, NULL, LLMNR_PORT, &sa);
}
break;
@ -562,28 +635,67 @@ static int dns_transaction_open_tcp(DnsTransaction *t) {
return -EAFNOSUPPORT;
}
if (fd < 0)
return fd;
if (!s) {
if (fd < 0)
return fd;
r = dns_stream_new(t->scope->manager, &t->stream, t->scope->protocol, fd);
if (r < 0)
return r;
fd = -1;
r = dns_stream_new(t->scope->manager, &s, t->scope->protocol, fd, &sa);
if (r < 0)
return r;
fd = -1;
if (t->server) {
dns_stream_unref(t->server->stream);
t->server->stream = dns_stream_ref(s);
s->server = dns_server_ref(t->server);
}
#if HAVE_GNUTLS
if (DNS_SERVER_FEATURE_LEVEL_IS_TLS(t->current_feature_level)) {
r = gnutls_init(&gs, GNUTLS_CLIENT | GNUTLS_ENABLE_FALSE_START | GNUTLS_NONBLOCK);
if (r < 0)
return r;
/* As DNS-over-TLS is a recent protocol, older TLS versions can be disabled */
r = gnutls_priority_set_direct(gs, "NORMAL:-VERS-ALL:+VERS-TLS1.2", NULL);
if (r < 0)
return r;
r = gnutls_credentials_set(gs, GNUTLS_CRD_CERTIFICATE, t->server->tls_cert_cred);
if (r < 0)
return r;
if (t->server && t->server->tls_session_data.size > 0)
gnutls_session_set_data(gs, t->server->tls_session_data.data, t->server->tls_session_data.size);
gnutls_handshake_set_timeout(gs, GNUTLS_DEFAULT_HANDSHAKE_TIMEOUT);
r = dns_stream_connect_tls(s, gs);
if (r < 0)
return r;
}
#endif
s->on_connection = on_stream_connection;
s->complete = on_stream_complete;
s->on_packet = dns_stream_on_packet;
/* The interface index is difficult to determine if we are
* connecting to the local host, hence fill this in right away
* instead of determining it from the socket */
s->ifindex = dns_scope_ifindex(t->scope);
}
t->stream = TAKE_PTR(s);
LIST_PREPEND(transactions_by_stream, t->stream->transactions, t);
r = dns_stream_write_packet(t->stream, t->sent);
if (r < 0) {
t->stream = dns_stream_unref(t->stream);
dns_transaction_close_connection(t);
return r;
}
t->stream->complete = on_stream_complete;
t->stream->transaction = t;
/* The interface index is difficult to determine if we are
* connecting to the local host, hence fill this in right away
* instead of determining it from the socket */
t->stream->ifindex = dns_scope_ifindex(t->scope);
dns_transaction_reset_answer(t);
t->tried_stream = true;
@ -929,7 +1041,17 @@ void dns_transaction_process_reply(DnsTransaction *t, DnsPacket *p) {
}
/* Reduce this feature level by one and try again. */
t->clamp_feature_level = t->current_feature_level - 1;
switch (t->current_feature_level) {
case DNS_SERVER_FEATURE_LEVEL_TLS_DO:
t->clamp_feature_level = DNS_SERVER_FEATURE_LEVEL_TLS_PLAIN;
break;
case DNS_SERVER_FEATURE_LEVEL_TLS_PLAIN + 1:
/* Skip plain TLS when TLS is not supported */
t->clamp_feature_level = DNS_SERVER_FEATURE_LEVEL_TLS_PLAIN - 1;
break;
default:
t->clamp_feature_level = t->current_feature_level - 1;
}
log_debug("Server returned error %s, retrying transaction with reduced feature level %s.",
dns_rcode_to_string(DNS_PACKET_RCODE(p)),
@ -971,7 +1093,7 @@ void dns_transaction_process_reply(DnsTransaction *t, DnsPacket *p) {
log_debug("Reply truncated, retrying via TCP.");
/* Response was truncated, let's try again with good old TCP */
r = dns_transaction_open_tcp(t);
r = dns_transaction_emit_tcp(t);
if (r == -ESRCH) {
/* No servers found? Damn! */
dns_transaction_complete(t, DNS_TRANSACTION_NO_SERVERS);
@ -1145,7 +1267,7 @@ static int dns_transaction_emit_udp(DnsTransaction *t) {
if (r < 0)
return r;
if (t->current_feature_level < DNS_SERVER_FEATURE_LEVEL_UDP)
if (t->current_feature_level < DNS_SERVER_FEATURE_LEVEL_UDP || DNS_SERVER_FEATURE_LEVEL_IS_TLS(t->current_feature_level))
return -EAGAIN; /* Sorry, can't do UDP, try TCP! */
if (!dns_server_dnssec_supported(t->server) && dns_type_is_dnssec(t->key->type))
@ -1627,7 +1749,7 @@ int dns_transaction_go(DnsTransaction *t) {
/* RFC 4795, Section 2.4. says reverse lookups shall
* always be made via TCP on LLMNR */
r = dns_transaction_open_tcp(t);
r = dns_transaction_emit_tcp(t);
} else {
/* Try via UDP, and if that fails due to large size or lack of
* support try via TCP */
@ -1635,9 +1757,9 @@ int dns_transaction_go(DnsTransaction *t) {
if (r == -EMSGSIZE)
log_debug("Sending query via TCP since it is too large.");
else if (r == -EAGAIN)
log_debug("Sending query via TCP since server doesn't support UDP.");
log_debug("Sending query via TCP since UDP isn't supported.");
if (IN_SET(r, -EMSGSIZE, -EAGAIN))
r = dns_transaction_open_tcp(t);
r = dns_transaction_emit_tcp(t);
}
if (r == -ESRCH) {

1
src/resolve/resolved-dns-transaction.h
View File

@ -136,6 +136,7 @@ struct DnsTransaction {
unsigned block_gc;
LIST_FIELDS(DnsTransaction, transactions_by_scope);
LIST_FIELDS(DnsTransaction, transactions_by_stream);
};
int dns_transaction_new(DnsTransaction **ret, DnsScope *s, DnsResourceKey *key);

1
src/resolve/resolved-gperf.gperf
View File

@ -23,5 +23,6 @@ Resolve.Domains, config_parse_search_domains, 0,
Resolve.LLMNR, config_parse_resolve_support, 0, offsetof(Manager, llmnr_support)
Resolve.MulticastDNS, config_parse_resolve_support, 0, offsetof(Manager, mdns_support)
Resolve.DNSSEC, config_parse_dnssec_mode, 0, offsetof(Manager, dnssec_mode)
Resolve.PrivateDNS, config_parse_private_dns_mode, 0, offsetof(Manager, private_dns_mode)
Resolve.Cache, config_parse_bool, 0, offsetof(Manager, enable_cache)
Resolve.DNSStubListener, config_parse_dns_stub_listener_mode, 0, offsetof(Manager, dns_stub_listener_mode)

51
src/resolve/resolved-link-bus.c
View File

@ -18,6 +18,23 @@
static BUS_DEFINE_PROPERTY_GET(property_get_dnssec_supported, "b", Link, link_dnssec_supported);
static BUS_DEFINE_PROPERTY_GET2(property_get_dnssec_mode, "s", Link, link_get_dnssec_mode, dnssec_mode_to_string);
static int property_get_private_dns_mode(
sd_bus *bus,
const char *path,
const char *interface,
const char *property,
sd_bus_message *reply,
void *userdata,
sd_bus_error *error) {
Link *l = userdata;
assert(reply);
assert(l);
return sd_bus_message_append(reply, "s", private_dns_mode_to_string(link_get_private_dns_mode(l)));
}
static int property_get_dns(
sd_bus *bus,
const char *path,
@ -402,6 +419,38 @@ int bus_link_method_set_mdns(sd_bus_message *message, void *userdata, sd_bus_err
return sd_bus_reply_method_return(message, NULL);
}
int bus_link_method_set_private_dns(sd_bus_message *message, void *userdata, sd_bus_error *error) {
Link *l = userdata;
const char *private_dns;
PrivateDnsMode mode;
int r;
assert(message);
assert(l);
r = verify_unmanaged_link(l, error);
if (r < 0)
return r;
r = sd_bus_message_read(message, "s", &private_dns);
if (r < 0)
return r;
if (isempty(private_dns))
mode = _PRIVATE_DNS_MODE_INVALID;
else {
mode = private_dns_mode_from_string(private_dns);
if (mode < 0)
return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Invalid PrivateDNS setting: %s", private_dns);
}
link_set_private_dns_mode(l, mode);
(void) link_save_user(l);
return sd_bus_reply_method_return(message, NULL);
}
int bus_link_method_set_dnssec(sd_bus_message *message, void *userdata, sd_bus_error *error) {
Link *l = userdata;
const char *dnssec;
@ -508,6 +557,7 @@ const sd_bus_vtable link_vtable[] = {
SD_BUS_PROPERTY("Domains", "a(sb)", property_get_domains, 0, 0),
SD_BUS_PROPERTY("LLMNR", "s", bus_property_get_resolve_support, offsetof(Link, llmnr_support), 0),
SD_BUS_PROPERTY("MulticastDNS", "s", bus_property_get_resolve_support, offsetof(Link, mdns_support), 0),
SD_BUS_PROPERTY("PrivateDNS", "s", property_get_private_dns_mode, 0, 0),
SD_BUS_PROPERTY("DNSSEC", "s", property_get_dnssec_mode, 0, 0),
SD_BUS_PROPERTY("DNSSECNegativeTrustAnchors", "as", property_get_ntas, 0, 0),
SD_BUS_PROPERTY("DNSSECSupported", "b", property_get_dnssec_supported, 0, 0),
@ -516,6 +566,7 @@ const sd_bus_vtable link_vtable[] = {
SD_BUS_METHOD("SetDomains", "a(sb)", NULL, bus_link_method_set_domains, 0),
SD_BUS_METHOD("SetLLMNR", "s", NULL, bus_link_method_set_llmnr, 0),
SD_BUS_METHOD("SetMulticastDNS", "s", NULL, bus_link_method_set_mdns, 0),
SD_BUS_METHOD("SetPrivateDNS", "s", NULL, bus_link_method_set_private_dns, 0),
SD_BUS_METHOD("SetDNSSEC", "s", NULL, bus_link_method_set_dnssec, 0),
SD_BUS_METHOD("SetDNSSECNegativeTrustAnchors", "as", NULL, bus_link_method_set_dnssec_negative_trust_anchors, 0),
SD_BUS_METHOD("Revert", NULL, NULL, bus_link_method_revert, 0),

1
src/resolve/resolved-link-bus.h
View File

@ -21,6 +21,7 @@ int bus_link_method_set_dns_servers(sd_bus_message *message, void *userdata, sd_
int bus_link_method_set_domains(sd_bus_message *message, void *userdata, sd_bus_error *error);
int bus_link_method_set_llmnr(sd_bus_message *message, void *userdata, sd_bus_error *error);
int bus_link_method_set_mdns(sd_bus_message *message, void *userdata, sd_bus_error *error);
int bus_link_method_set_private_dns(sd_bus_message *message, void *userdata, sd_bus_error *error);
int bus_link_method_set_dnssec(sd_bus_message *message, void *userdata, sd_bus_error *error);
int bus_link_method_set_dnssec_negative_trust_anchors(sd_bus_message *message, void *userdata, sd_bus_error *error);
int bus_link_method_revert(sd_bus_message *message, void *userdata, sd_bus_error *error);

55
src/resolve/resolved-link.c
View File

@ -41,6 +41,7 @@ int link_new(Manager *m, Link **ret, int ifindex) {
l->llmnr_support = RESOLVE_SUPPORT_YES;
l->mdns_support = RESOLVE_SUPPORT_NO;
l->dnssec_mode = _DNSSEC_MODE_INVALID;
l->private_dns_mode = _PRIVATE_DNS_MODE_INVALID;
l->operstate = IF_OPER_UNKNOWN;
if (asprintf(&l->state_file, "/run/systemd/resolve/netif/%i", ifindex) < 0)
@ -65,6 +66,7 @@ void link_flush_settings(Link *l) {
l->llmnr_support = RESOLVE_SUPPORT_YES;
l->mdns_support = RESOLVE_SUPPORT_NO;
l->dnssec_mode = _DNSSEC_MODE_INVALID;
l->private_dns_mode = _PRIVATE_DNS_MODE_INVALID;
dns_server_unlink_all(l->dns_servers);
dns_search_domain_unlink_all(l->search_domains);
@ -352,6 +354,46 @@ clear:
return r;
}
void link_set_private_dns_mode(Link *l, PrivateDnsMode mode) {
assert(l);
#if ! HAVE_GNUTLS
if (mode != PRIVATE_DNS_NO)
log_warning("Private DNS option for the link cannot be set to opportunistic when systemd-resolved is built without gnutls support. Turning off Private DNS support.");
return;
#endif
l->private_dns_mode = mode;
}
static int link_update_private_dns_mode(Link *l) {
_cleanup_free_ char *b = NULL;
int r;
assert(l);
r = sd_network_link_get_private_dns(l->ifindex, &b);
if (r == -ENODATA) {
r = 0;
goto clear;
}
if (r < 0)
goto clear;
l->private_dns_mode = private_dns_mode_from_string(b);
if (l->private_dns_mode < 0) {
r = -EINVAL;
goto clear;
}
return 0;
clear:
l->private_dns_mode = _PRIVATE_DNS_MODE_INVALID;
return r;
}
void link_set_dnssec_mode(Link *l, DnssecMode mode) {
assert(l);
@ -559,6 +601,10 @@ static void link_read_settings(Link *l) {
if (r < 0)
log_warning_errno(r, "Failed to read mDNS support for interface %s, ignoring: %m", l->name);
r = link_update_private_dns_mode(l);
if (r < 0)
log_warning_errno(r, "Failed to read Private DNS mode for interface %s, ignoring: %m", l->name);
r = link_update_dnssec_mode(l);
if (r < 0)
log_warning_errno(r, "Failed to read DNSSEC mode for interface %s, ignoring: %m", l->name);
@ -692,6 +738,15 @@ void link_next_dns_server(Link *l) {
link_set_dns_server(l, l->dns_servers);
}
PrivateDnsMode link_get_private_dns_mode(Link *l) {
assert(l);
if (l->private_dns_mode != _PRIVATE_DNS_MODE_INVALID)
return l->private_dns_mode;
return manager_get_private_dns_mode(l->manager);
}
DnssecMode link_get_dnssec_mode(Link *l) {
assert(l);

4
src/resolve/resolved-link.h
View File

@ -59,6 +59,7 @@ struct Link {
ResolveSupport llmnr_support;
ResolveSupport mdns_support;
PrivateDnsMode private_dns_mode;
DnssecMode dnssec_mode;
Set *dnssec_negative_trust_anchors;
@ -90,6 +91,7 @@ void link_add_rrs(Link *l, bool force_remove);
void link_flush_settings(Link *l);
void link_set_dnssec_mode(Link *l, DnssecMode mode);
void link_set_private_dns_mode(Link *l, PrivateDnsMode mode);
void link_allocate_scopes(Link *l);
DnsServer* link_set_dns_server(Link *l, DnsServer *s);
@ -99,6 +101,8 @@ void link_next_dns_server(Link *l);
DnssecMode link_get_dnssec_mode(Link *l);
bool link_dnssec_supported(Link *l);
PrivateDnsMode link_get_private_dns_mode(Link *l);
int link_save_user(Link *l);
int link_load_user(Link *l);
void link_remove_user(Link *l);

2
src/resolve/resolved-llmnr.c
View File

@ -345,7 +345,7 @@ static int on_llmnr_stream(sd_event_source *s, int fd, uint32_t revents, void *u
return -errno;
}
r = dns_stream_new(m, &stream, DNS_PROTOCOL_LLMNR, cfd);
r = dns_stream_new(m, &stream, DNS_PROTOCOL_LLMNR, cfd, NULL);
if (r < 0) {
safe_close(cfd);
return r;

10
src/resolve/resolved-manager.c
View File

@ -580,6 +580,7 @@ int manager_new(Manager **ret) {
m->llmnr_support = RESOLVE_SUPPORT_YES;
m->mdns_support = RESOLVE_SUPPORT_YES;
m->dnssec_mode = DEFAULT_DNSSEC_MODE;
m->private_dns_mode = DEFAULT_PRIVATE_DNS_MODE;
m->enable_cache = true;
m->dns_stub_listener_mode = DNS_STUB_LISTENER_UDP;
m->read_resolv_conf = true;
@ -1384,6 +1385,15 @@ bool manager_dnssec_supported(Manager *m) {
return true;
}
PrivateDnsMode manager_get_private_dns_mode(Manager *m) {
assert(m);
if (m->private_dns_mode != _PRIVATE_DNS_MODE_INVALID)
return m->private_dns_mode;
return _PRIVATE_DNS_MODE_INVALID;
}
void manager_dnssec_verdict(Manager *m, DnssecVerdict verdict, const DnsResourceKey *key) {
assert(verdict >= 0);

3
src/resolve/resolved-manager.h
View File

@ -35,6 +35,7 @@ struct Manager {
ResolveSupport llmnr_support;
ResolveSupport mdns_support;
DnssecMode dnssec_mode;
PrivateDnsMode private_dns_mode;
bool enable_cache;
DnsStubListenerMode dns_stub_listener_mode;
@ -172,6 +173,8 @@ int manager_compile_search_domains(Manager *m, OrderedSet **domains, int filter_
DnssecMode manager_get_dnssec_mode(Manager *m);
bool manager_dnssec_supported(Manager *m);
PrivateDnsMode manager_get_private_dns_mode(Manager *m);
void manager_dnssec_verdict(Manager *m, DnssecVerdict verdict, const DnsResourceKey *key);
bool manager_routable(Manager *m, int family);

1
src/resolve/resolved.conf.in
View File

@ -18,5 +18,6 @@
#LLMNR=yes
#MulticastDNS=yes
#DNSSEC=@DEFAULT_DNSSEC_MODE@
#PrivateDNS=@DEFAULT_PRIVATE_DNS_MODE@
#Cache=yes
#DNSStubListener=udp

7
src/shared/resolve-util.c
View File

@ -11,6 +11,7 @@
DEFINE_CONFIG_PARSE_ENUM(config_parse_resolve_support, resolve_support, ResolveSupport, "Failed to parse resolve support setting");
DEFINE_CONFIG_PARSE_ENUM(config_parse_dnssec_mode, dnssec_mode, DnssecMode, "Failed to parse DNSSEC mode setting");
DEFINE_CONFIG_PARSE_ENUM(config_parse_private_dns_mode, private_dns_mode, PrivateDnsMode, "Failed to parse private DNS mode setting");
static const char* const resolve_support_table[_RESOLVE_SUPPORT_MAX] = {
[RESOLVE_SUPPORT_NO] = "no",
@ -25,3 +26,9 @@ static const char* const dnssec_mode_table[_DNSSEC_MODE_MAX] = {
[DNSSEC_YES] = "yes",
};
DEFINE_STRING_TABLE_LOOKUP_WITH_BOOLEAN(dnssec_mode, DnssecMode, DNSSEC_YES);
static const char* const private_dns_mode_table[_PRIVATE_DNS_MODE_MAX] = {
[PRIVATE_DNS_NO] = "no",
[PRIVATE_DNS_OPPORTUNISTIC] = "opportunistic",
};
DEFINE_STRING_TABLE_LOOKUP_WITH_BOOLEAN(private_dns_mode, PrivateDnsMode, PRIVATE_DNS_OPPORTUNISTIC);

17
src/shared/resolve-util.h
View File

@ -12,6 +12,7 @@
typedef enum ResolveSupport ResolveSupport;
typedef enum DnssecMode DnssecMode;
typedef enum PrivateDnsMode PrivateDnsMode;
enum ResolveSupport {
RESOLVE_SUPPORT_NO,
@ -39,11 +40,27 @@ enum DnssecMode {
_DNSSEC_MODE_INVALID = -1
};
enum PrivateDnsMode {
/* No connection is made for DNS-over-TLS */
PRIVATE_DNS_NO,
/* Try to connect using DNS-over-TLS, but if connection fails,
* fallback to using an unencrypted connection */
PRIVATE_DNS_OPPORTUNISTIC,
_PRIVATE_DNS_MODE_MAX,
_PRIVATE_DNS_MODE_INVALID = -1
};
CONFIG_PARSER_PROTOTYPE(config_parse_resolve_support);
CONFIG_PARSER_PROTOTYPE(config_parse_dnssec_mode);
CONFIG_PARSER_PROTOTYPE(config_parse_private_dns_mode);
const char* resolve_support_to_string(ResolveSupport p) _const_;
ResolveSupport resolve_support_from_string(const char *s) _pure_;
const char* dnssec_mode_to_string(DnssecMode p) _const_;
DnssecMode dnssec_mode_from_string(const char *s) _pure_;
const char* private_dns_mode_to_string(PrivateDnsMode p) _const_;
PrivateDnsMode private_dns_mode_from_string(const char *s) _pure_;

8
src/systemd/sd-network.h
View File

@ -129,6 +129,14 @@ int sd_network_link_get_llmnr(int ifindex, char **llmnr);
*/
int sd_network_link_get_mdns(int ifindex, char **mdns);
/* Indicates whether or not Private DNS should be enabled for the
* link.
* Possible levels of support: strict, no, opportunistic
* Possible return codes:
* -ENODATA: networkd is not aware of the link
*/
int sd_network_link_get_private_dns(int ifindex, char **private_dns);
/* Indicates whether or not DNSSEC should be enabled for the link
* Possible levels of support: yes, no, allow-downgrade
* Possible return codes: