Add support for DNS-over-TLS using GnuTLS. To reduce latency also TLS False Start and TLS session resumption is supported.
'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
libbasic_gcrypt,
libsystemd_resolve_core],
dependencies : [threads,
+ libgnutls,
libgpg_error,
libm,
libidn],
'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)]
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')
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;
}
s->dnssec_mode = link_get_dnssec_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);
DnsProtocol protocol;
int family;
DnssecMode dnssec_mode;
+ PrivateDnsMode private_dns_mode;
Link *link;
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 */
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);
}
s->n_failed_udp = 0;
s->n_failed_tcp = 0;
+ s->n_failed_tls = 0;
s->packet_truncated = false;
s->verified_usec = 0;
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;
+
+ /* Successful TCP connections are only useful to verify the TCP feature level. */
+ level = DNS_SERVER_FEATURE_LEVEL_TCP;
+ }
+ }
- if (s->possible_feature_level == level)
- s->n_failed_tcp = 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_IS_TLS(level) ? DNS_SERVER_FEATURE_LEVEL_TLS_PLAIN : DNS_SERVER_FEATURE_LEVEL_EDNS0;
- /* Successful TCP connections are only useful to verify the TCP feature level. */
- level = DNS_SERVER_FEATURE_LEVEL_TCP;
- }
+ /* 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);
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)
/* 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;
}
/* 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. */
* 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) {
* 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)) {
return manager_get_dnssec_mode(s->manager);
}
+PrivateDnsMode dns_server_get_private_dns_mode(DnsServer *s) {
+ assert(s);
+
+ return manager_get_private_dns_mode(s->manager);
+}
+
void dns_server_flush_cache(DnsServer *s) {
DnsServer *current;
DnsScope *scope;
[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);
#include "in-addr-util.h"
+#if HAVE_GNUTLS
+#include <gnutls/gnutls.h>
+#endif
+
typedef struct DnsServer DnsServer;
typedef enum DnsServerType {
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_;
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;
unsigned n_failed_udp;
unsigned n_failed_tcp;
+ unsigned n_failed_tls;
bool packet_truncated:1;
bool packet_bad_opt:1;
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);
#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);
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);
return 0;
}
-static ssize_t dns_stream_writev(DnsStream *s, const struct iovec *iov, size_t iovcnt) {
+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,
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;
assert(s);
+#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);
IOVEC_INCREMENT(iov, 2, s->n_written);
- ss = dns_stream_writev(s, 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);
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);
}
}
- 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) {
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));
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;
#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
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;
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);
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, 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);
#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)
return 0;
}
+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;
_cleanup_(dns_stream_unrefp) DnsStream *s = NULL;
union sockaddr_union sa;
int r;
+#if HAVE_GNUTLS
+ gnutls_session_t gs;
+#endif
assert(t);
if (r < 0)
return r;
- if (t->server->stream)
+ 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, 53, &sa);
+ 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;
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;
}
/* 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)),
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))
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_emit_tcp(t);
}
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)
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;
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);
ResolveSupport llmnr_support;
ResolveSupport mdns_support;
DnssecMode dnssec_mode;
+ PrivateDnsMode private_dns_mode;
bool enable_cache;
DnsStubListenerMode dns_stub_listener_mode;
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);
#LLMNR=yes
#MulticastDNS=yes
#DNSSEC=@DEFAULT_DNSSEC_MODE@
+#PrivateDNS=@DEFAULT_PRIVATE_DNS@
#Cache=yes
#DNSStubListener=udp
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",
[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);
typedef enum ResolveSupport ResolveSupport;
typedef enum DnssecMode DnssecMode;
+typedef enum PrivateDnsMode PrivateDnsMode;
enum ResolveSupport {
RESOLVE_SUPPORT_NO,
_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_;
projects / thirdparty / systemd.git / commitdiff
