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Diffstat (limited to 'src/resolve/resolved-dns-query.c')
-rw-r--r--src/resolve/resolved-dns-query.c822
1 files changed, 364 insertions, 458 deletions
diff --git a/src/resolve/resolved-dns-query.c b/src/resolve/resolved-dns-query.c
index a6565f2ba2..b8bdff9dfa 100644
--- a/src/resolve/resolved-dns-query.c
+++ b/src/resolve/resolved-dns-query.c
@@ -21,9 +21,13 @@
#include "alloc-util.h"
#include "dns-domain.h"
+#include "dns-type.h"
#include "hostname-util.h"
#include "local-addresses.h"
#include "resolved-dns-query.h"
+#include "resolved-dns-synthesize.h"
+#include "resolved-etc-hosts.h"
+#include "string-util.h"
/* How long to wait for the query in total */
#define QUERY_TIMEOUT_USEC (30 * USEC_PER_SEC)
@@ -90,17 +94,20 @@ static int dns_query_candidate_next_search_domain(DnsQueryCandidate *c) {
assert(c);
- if (c->search_domain && c->search_domain->linked) {
+ if (c->search_domain && c->search_domain->linked)
next = c->search_domain->domains_next;
+ else
+ next = dns_scope_get_search_domains(c->scope);
+ for (;;) {
if (!next) /* We hit the end of the list */
return 0;
- } else {
- next = dns_scope_get_search_domains(c->scope);
+ if (!next->route_only)
+ break;
- if (!next) /* OK, there's nothing. */
- return 0;
+ /* Skip over route-only domains */
+ next = next->domains_next;
}
dns_search_domain_unref(c->search_domain);
@@ -155,6 +162,7 @@ static int dns_query_candidate_go(DnsQueryCandidate *c) {
DnsTransaction *t;
Iterator i;
int r;
+ unsigned n = 0;
assert(c);
@@ -166,8 +174,14 @@ static int dns_query_candidate_go(DnsQueryCandidate *c) {
r = dns_transaction_go(t);
if (r < 0)
return r;
+
+ n++;
}
+ /* If there was nothing to start, then let's proceed immediately */
+ if (n == 0)
+ dns_query_candidate_notify(c);
+
return 0;
}
@@ -179,12 +193,20 @@ static DnsTransactionState dns_query_candidate_state(DnsQueryCandidate *c) {
assert(c);
if (c->error_code != 0)
- return DNS_TRANSACTION_RESOURCES;
+ return DNS_TRANSACTION_ERRNO;
SET_FOREACH(t, c->transactions, i) {
switch (t->state) {
+ case DNS_TRANSACTION_NULL:
+ /* If there's a NULL transaction pending, then
+ * this means not all transactions where
+ * started yet, and we were called from within
+ * the stackframe that is supposed to start
+ * remaining transactions. In this case,
+ * simply claim the candidate is pending. */
+
case DNS_TRANSACTION_PENDING:
case DNS_TRANSACTION_VALIDATING:
/* If there's one transaction currently in
@@ -197,9 +219,6 @@ static DnsTransactionState dns_query_candidate_state(DnsQueryCandidate *c) {
state = t->state;
break;
- case DNS_TRANSACTION_NULL:
- assert_not_reached("Transaction not started?");
-
default:
if (state != DNS_TRANSACTION_SUCCESS)
state = t->state;
@@ -211,7 +230,33 @@ static DnsTransactionState dns_query_candidate_state(DnsQueryCandidate *c) {
return state;
}
+static bool dns_query_candidate_is_routable(DnsQueryCandidate *c, uint16_t type) {
+ int family;
+
+ assert(c);
+
+ /* Checks whether the specified RR type matches an address family that is routable on the link(s) the scope of
+ * this candidate belongs to. Specifically, whether there's a routable IPv4 address on it if we query an A RR,
+ * or a routable IPv6 address if we query an AAAA RR. */
+
+ if (!c->query->suppress_unroutable_family)
+ return true;
+
+ if (c->scope->protocol != DNS_PROTOCOL_DNS)
+ return true;
+
+ family = dns_type_to_af(type);
+ if (family < 0)
+ return true;
+
+ if (c->scope->link)
+ return link_relevant(c->scope->link, family, false);
+ else
+ return manager_routable(c->scope->manager, family);
+}
+
static int dns_query_candidate_setup_transactions(DnsQueryCandidate *c) {
+ DnsQuestion *question;
DnsResourceKey *key;
int n = 0, r;
@@ -219,17 +264,29 @@ static int dns_query_candidate_setup_transactions(DnsQueryCandidate *c) {
dns_query_candidate_stop(c);
+ question = dns_query_question_for_protocol(c->query, c->scope->protocol);
+
/* Create one transaction per question key */
- DNS_QUESTION_FOREACH(key, c->query->question) {
+ DNS_QUESTION_FOREACH(key, question) {
_cleanup_(dns_resource_key_unrefp) DnsResourceKey *new_key = NULL;
+ DnsResourceKey *qkey;
+
+ if (!dns_query_candidate_is_routable(c, key->type))
+ continue;
if (c->search_domain) {
r = dns_resource_key_new_append_suffix(&new_key, key, c->search_domain->name);
if (r < 0)
goto fail;
- }
- r = dns_query_candidate_add_transaction(c, new_key ?: key);
+ qkey = new_key;
+ } else
+ qkey = key;
+
+ if (!dns_scope_good_key(c->scope, qkey))
+ continue;
+
+ r = dns_query_candidate_add_transaction(c, qkey);
if (r < 0)
goto fail;
@@ -300,6 +357,26 @@ static void dns_query_stop(DnsQuery *q) {
dns_query_candidate_stop(c);
}
+static void dns_query_free_candidates(DnsQuery *q) {
+ assert(q);
+
+ while (q->candidates)
+ dns_query_candidate_free(q->candidates);
+}
+
+static void dns_query_reset_answer(DnsQuery *q) {
+ assert(q);
+
+ q->answer = dns_answer_unref(q->answer);
+ q->answer_rcode = 0;
+ q->answer_dnssec_result = _DNSSEC_RESULT_INVALID;
+ q->answer_errno = 0;
+ q->answer_authenticated = false;
+ q->answer_protocol = _DNS_PROTOCOL_INVALID;
+ q->answer_family = AF_UNSPEC;
+ q->answer_search_domain = dns_search_domain_unref(q->answer_search_domain);
+}
+
DnsQuery *dns_query_free(DnsQuery *q) {
if (!q)
return NULL;
@@ -313,16 +390,18 @@ DnsQuery *dns_query_free(DnsQuery *q) {
LIST_REMOVE(auxiliary_queries, q->auxiliary_for->auxiliary_queries, q);
}
- while (q->candidates)
- dns_query_candidate_free(q->candidates);
+ dns_query_free_candidates(q);
- dns_question_unref(q->question);
- dns_answer_unref(q->answer);
- dns_search_domain_unref(q->answer_search_domain);
+ dns_question_unref(q->question_idna);
+ dns_question_unref(q->question_utf8);
+
+ dns_query_reset_answer(q);
sd_bus_message_unref(q->request);
sd_bus_track_unref(q->bus_track);
+ free(q->request_address_string);
+
if (q->manager) {
LIST_REMOVE(queries, q->manager->dns_queries, q);
q->manager->n_dns_queries--;
@@ -333,17 +412,50 @@ DnsQuery *dns_query_free(DnsQuery *q) {
return NULL;
}
-int dns_query_new(Manager *m, DnsQuery **ret, DnsQuestion *question, int ifindex, uint64_t flags) {
+int dns_query_new(
+ Manager *m,
+ DnsQuery **ret,
+ DnsQuestion *question_utf8,
+ DnsQuestion *question_idna,
+ int ifindex, uint64_t flags) {
+
_cleanup_(dns_query_freep) DnsQuery *q = NULL;
- unsigned i;
+ DnsResourceKey *key;
+ bool good = false;
int r;
assert(m);
- assert(question);
- r = dns_question_is_valid_for_query(question);
+ if (dns_question_size(question_utf8) > 0) {
+ r = dns_question_is_valid_for_query(question_utf8);
+ if (r < 0)
+ return r;
+ if (r == 0)
+ return -EINVAL;
+
+ good = true;
+ }
+
+ /* If the IDNA and UTF8 questions are the same, merge their references */
+ r = dns_question_is_equal(question_idna, question_utf8);
if (r < 0)
return r;
+ if (r > 0)
+ question_idna = question_utf8;
+ else {
+ if (dns_question_size(question_idna) > 0) {
+ r = dns_question_is_valid_for_query(question_idna);
+ if (r < 0)
+ return r;
+ if (r == 0)
+ return -EINVAL;
+
+ good = true;
+ }
+ }
+
+ if (!good) /* don't allow empty queries */
+ return -EINVAL;
if (m->n_dns_queries >= QUERIES_MAX)
return -EBUSY;
@@ -352,20 +464,40 @@ int dns_query_new(Manager *m, DnsQuery **ret, DnsQuestion *question, int ifindex
if (!q)
return -ENOMEM;
- q->question = dns_question_ref(question);
+ q->question_utf8 = dns_question_ref(question_utf8);
+ q->question_idna = dns_question_ref(question_idna);
q->ifindex = ifindex;
q->flags = flags;
- q->answer_family = AF_UNSPEC;
+ q->answer_dnssec_result = _DNSSEC_RESULT_INVALID;
q->answer_protocol = _DNS_PROTOCOL_INVALID;
+ q->answer_family = AF_UNSPEC;
+
+ /* First dump UTF8 question */
+ DNS_QUESTION_FOREACH(key, question_utf8) {
+ _cleanup_free_ char *p = NULL;
+
+ r = dns_resource_key_to_string(key, &p);
+ if (r < 0)
+ return r;
+
+ log_debug("Looking up RR for %s.", strstrip(p));
+ }
+
+ /* And then dump the IDNA question, but only what hasn't been dumped already through the UTF8 question. */
+ DNS_QUESTION_FOREACH(key, question_idna) {
+ _cleanup_free_ char *p = NULL;
- for (i = 0; i < question->n_keys; i++) {
- _cleanup_free_ char *p;
+ r = dns_question_contains(question_utf8, key);
+ if (r < 0)
+ return r;
+ if (r > 0)
+ continue;
- r = dns_resource_key_to_string(question->keys[i], &p);
+ r = dns_resource_key_to_string(key, &p);
if (r < 0)
return r;
- log_debug("Looking up RR for %s", p);
+ log_debug("Looking up IDNA RR for %s.", strstrip(p));
}
LIST_PREPEND(queries, m->dns_queries, q);
@@ -441,7 +573,7 @@ static int dns_query_add_candidate(DnsQuery *q, DnsScope *s) {
/* If this a single-label domain on DNS, we might append a suitable search domain first. */
if ((q->flags & SD_RESOLVED_NO_SEARCH) == 0) {
- r = dns_scope_name_needs_search_domain(s, dns_question_first_name(q->question));
+ r = dns_scope_name_needs_search_domain(s, dns_question_first_name(q->question_idna));
if (r < 0)
goto fail;
if (r > 0) {
@@ -464,413 +596,73 @@ fail:
return r;
}
-static int SYNTHESIZE_IFINDEX(int ifindex) {
-
- /* When the caller asked for resolving on a specific
- * interface, we synthesize the answer for that
- * interface. However, if nothing specific was claimed and we
- * only return localhost RRs, we synthesize the answer for
- * localhost. */
-
- if (ifindex > 0)
- return ifindex;
-
- return LOOPBACK_IFINDEX;
-}
-
-static int SYNTHESIZE_FAMILY(uint64_t flags) {
-
- /* Picks an address family depending on set flags. This is
- * purely for synthesized answers, where the family we return
- * for the reply should match what was requested in the
- * question, even though we are synthesizing the answer
- * here. */
-
- if (!(flags & SD_RESOLVED_DNS)) {
- if (flags & SD_RESOLVED_LLMNR_IPV4)
- return AF_INET;
- if (flags & SD_RESOLVED_LLMNR_IPV6)
- return AF_INET6;
- }
-
- return AF_UNSPEC;
-}
-
-static DnsProtocol SYNTHESIZE_PROTOCOL(uint64_t flags) {
-
- /* Similar as SYNTHESIZE_FAMILY() but does this for the
- * protocol. If resolving via DNS was requested, we claim it
- * was DNS. Similar, if nothing specific was
- * requested. However, if only resolving via LLMNR was
- * requested we return that. */
-
- if (flags & SD_RESOLVED_DNS)
- return DNS_PROTOCOL_DNS;
- if (flags & SD_RESOLVED_LLMNR)
- return DNS_PROTOCOL_LLMNR;
-
- return DNS_PROTOCOL_DNS;
-}
-
-static int dns_type_to_af(uint16_t t) {
- switch (t) {
-
- case DNS_TYPE_A:
- return AF_INET;
-
- case DNS_TYPE_AAAA:
- return AF_INET6;
-
- case DNS_TYPE_ANY:
- return AF_UNSPEC;
-
- default:
- return -EINVAL;
- }
-}
-
-static int synthesize_localhost_rr(DnsQuery *q, DnsResourceKey *key, DnsAnswer **answer) {
- int r;
-
- assert(q);
- assert(key);
- assert(answer);
-
- r = dns_answer_reserve(answer, 2);
- if (r < 0)
- return r;
-
- if (IN_SET(key->type, DNS_TYPE_A, DNS_TYPE_ANY)) {
- _cleanup_(dns_resource_record_unrefp) DnsResourceRecord *rr = NULL;
-
- rr = dns_resource_record_new_full(DNS_CLASS_IN, DNS_TYPE_A, DNS_RESOURCE_KEY_NAME(key));
- if (!rr)
- return -ENOMEM;
-
- rr->a.in_addr.s_addr = htobe32(INADDR_LOOPBACK);
-
- r = dns_answer_add(*answer, rr, SYNTHESIZE_IFINDEX(q->ifindex));
- if (r < 0)
- return r;
- }
-
- if (IN_SET(key->type, DNS_TYPE_AAAA, DNS_TYPE_ANY)) {
- _cleanup_(dns_resource_record_unrefp) DnsResourceRecord *rr = NULL;
-
- rr = dns_resource_record_new_full(DNS_CLASS_IN, DNS_TYPE_AAAA, DNS_RESOURCE_KEY_NAME(key));
- if (!rr)
- return -ENOMEM;
-
- rr->aaaa.in6_addr = in6addr_loopback;
-
- r = dns_answer_add(*answer, rr, SYNTHESIZE_IFINDEX(q->ifindex));
- if (r < 0)
- return r;
- }
-
- return 0;
-}
-
-static int answer_add_ptr(DnsAnswer **answer, const char *from, const char *to, int ifindex) {
- _cleanup_(dns_resource_record_unrefp) DnsResourceRecord *rr = NULL;
-
- rr = dns_resource_record_new_full(DNS_CLASS_IN, DNS_TYPE_PTR, from);
- if (!rr)
- return -ENOMEM;
-
- rr->ptr.name = strdup(to);
- if (!rr->ptr.name)
- return -ENOMEM;
-
- return dns_answer_add(*answer, rr, ifindex);
-}
-
-static int synthesize_localhost_ptr(DnsQuery *q, DnsResourceKey *key, DnsAnswer **answer) {
- int r;
-
- assert(q);
- assert(key);
- assert(answer);
-
- r = dns_answer_reserve(answer, 1);
- if (r < 0)
- return r;
-
- if (IN_SET(key->type, DNS_TYPE_PTR, DNS_TYPE_ANY)) {
- r = answer_add_ptr(answer, DNS_RESOURCE_KEY_NAME(key), "localhost", SYNTHESIZE_IFINDEX(q->ifindex));
- if (r < 0)
- return r;
- }
-
- return 0;
-}
-
-static int answer_add_addresses_rr(
- DnsAnswer **answer,
- const char *name,
- struct local_address *addresses,
- unsigned n_addresses) {
-
- unsigned j;
- int r;
-
- assert(answer);
- assert(name);
-
- r = dns_answer_reserve(answer, n_addresses);
- if (r < 0)
- return r;
-
- for (j = 0; j < n_addresses; j++) {
- _cleanup_(dns_resource_record_unrefp) DnsResourceRecord *rr = NULL;
-
- r = dns_resource_record_new_address(&rr, addresses[j].family, &addresses[j].address, name);
- if (r < 0)
- return r;
-
- r = dns_answer_add(*answer, rr, addresses[j].ifindex);
- if (r < 0)
- return r;
- }
-
- return 0;
-}
-
-static int answer_add_addresses_ptr(
- DnsAnswer **answer,
- const char *name,
- struct local_address *addresses,
- unsigned n_addresses,
- int af, const union in_addr_union *match) {
-
- unsigned j;
- int r;
-
- assert(answer);
- assert(name);
-
- for (j = 0; j < n_addresses; j++) {
- _cleanup_(dns_resource_record_unrefp) DnsResourceRecord *rr = NULL;
-
- if (af != AF_UNSPEC) {
-
- if (addresses[j].family != af)
- continue;
-
- if (match && !in_addr_equal(af, match, &addresses[j].address))
- continue;
- }
-
- r = dns_answer_reserve(answer, 1);
- if (r < 0)
- return r;
-
- r = dns_resource_record_new_reverse(&rr, addresses[j].family, &addresses[j].address, name);
- if (r < 0)
- return r;
-
- r = dns_answer_add(*answer, rr, addresses[j].ifindex);
- if (r < 0)
- return r;
- }
-
- return 0;
-}
-
-static int synthesize_system_hostname_rr(DnsQuery *q, DnsResourceKey *key, DnsAnswer **answer) {
- _cleanup_free_ struct local_address *addresses = NULL;
- int n = 0, af;
-
- assert(q);
- assert(key);
- assert(answer);
-
- af = dns_type_to_af(key->type);
- if (af >= 0) {
- n = local_addresses(q->manager->rtnl, q->ifindex, af, &addresses);
- if (n < 0)
- return n;
-
- if (n == 0) {
- struct local_address buffer[2];
-
- /* If we have no local addresses then use ::1
- * and 127.0.0.2 as local ones. */
-
- if (af == AF_INET || af == AF_UNSPEC)
- buffer[n++] = (struct local_address) {
- .family = AF_INET,
- .ifindex = SYNTHESIZE_IFINDEX(q->ifindex),
- .address.in.s_addr = htobe32(0x7F000002),
- };
-
- if (af == AF_INET6 || af == AF_UNSPEC)
- buffer[n++] = (struct local_address) {
- .family = AF_INET6,
- .ifindex = SYNTHESIZE_IFINDEX(q->ifindex),
- .address.in6 = in6addr_loopback,
- };
-
- return answer_add_addresses_rr(answer, DNS_RESOURCE_KEY_NAME(key), buffer, n);
- }
- }
-
- return answer_add_addresses_rr(answer, DNS_RESOURCE_KEY_NAME(key), addresses, n);
-}
-
-static int synthesize_system_hostname_ptr(DnsQuery *q, int af, const union in_addr_union *address, DnsAnswer **answer) {
- _cleanup_free_ struct local_address *addresses = NULL;
- int n, r;
-
- assert(q);
- assert(address);
- assert(answer);
-
- if (af == AF_INET && address->in.s_addr == htobe32(0x7F000002)) {
-
- /* Always map the IPv4 address 127.0.0.2 to the local
- * hostname, in addition to "localhost": */
-
- r = dns_answer_reserve(answer, 3);
- if (r < 0)
- return r;
-
- r = answer_add_ptr(answer, "2.0.0.127.in-addr.arpa", q->manager->llmnr_hostname, SYNTHESIZE_IFINDEX(q->ifindex));
- if (r < 0)
- return r;
-
- r = answer_add_ptr(answer, "2.0.0.127.in-addr.arpa", q->manager->mdns_hostname, SYNTHESIZE_IFINDEX(q->ifindex));
- if (r < 0)
- return r;
-
- r = answer_add_ptr(answer, "2.0.0.127.in-addr.arpa", "localhost", SYNTHESIZE_IFINDEX(q->ifindex));
- if (r < 0)
- return r;
-
- return 0;
- }
-
- n = local_addresses(q->manager->rtnl, q->ifindex, af, &addresses);
- if (n < 0)
- return n;
-
- r = answer_add_addresses_ptr(answer, q->manager->llmnr_hostname, addresses, n, af, address);
- if (r < 0)
- return r;
-
- return answer_add_addresses_ptr(answer, q->manager->mdns_hostname, addresses, n, af, address);
-}
-
-static int synthesize_gateway_rr(DnsQuery *q, DnsResourceKey *key, DnsAnswer **answer) {
- _cleanup_free_ struct local_address *addresses = NULL;
- int n = 0, af;
-
- assert(q);
- assert(key);
- assert(answer);
-
- af = dns_type_to_af(key->type);
- if (af >= 0) {
- n = local_gateways(q->manager->rtnl, q->ifindex, af, &addresses);
- if (n < 0)
- return n;
- }
-
- return answer_add_addresses_rr(answer, DNS_RESOURCE_KEY_NAME(key), addresses, n);
-}
-
-static int synthesize_gateway_ptr(DnsQuery *q, int af, const union in_addr_union *address, DnsAnswer **answer) {
- _cleanup_free_ struct local_address *addresses = NULL;
- int n;
-
- assert(q);
- assert(address);
- assert(answer);
-
- n = local_gateways(q->manager->rtnl, q->ifindex, af, &addresses);
- if (n < 0)
- return n;
-
- return answer_add_addresses_ptr(answer, "gateway", addresses, n, af, address);
-}
-
static int dns_query_synthesize_reply(DnsQuery *q, DnsTransactionState *state) {
_cleanup_(dns_answer_unrefp) DnsAnswer *answer = NULL;
- unsigned i;
int r;
assert(q);
assert(state);
- /* Tries to synthesize localhost RR replies where appropriate */
+ /* Tries to synthesize localhost RR replies (and others) where appropriate. Note that this is done *after* the
+ * the normal lookup finished. The data from the network hence takes precedence over the data we
+ * synthesize. (But note that many scopes refuse to resolve certain domain names) */
if (!IN_SET(*state,
- DNS_TRANSACTION_FAILURE,
+ DNS_TRANSACTION_RCODE_FAILURE,
DNS_TRANSACTION_NO_SERVERS,
DNS_TRANSACTION_TIMEOUT,
- DNS_TRANSACTION_ATTEMPTS_MAX_REACHED))
+ DNS_TRANSACTION_ATTEMPTS_MAX_REACHED,
+ DNS_TRANSACTION_NETWORK_DOWN,
+ DNS_TRANSACTION_NOT_FOUND))
return 0;
- for (i = 0; i < q->question->n_keys; i++) {
- union in_addr_union address;
- const char *name;
- int af;
-
- if (q->question->keys[i]->class != DNS_CLASS_IN &&
- q->question->keys[i]->class != DNS_CLASS_ANY)
- continue;
+ r = dns_synthesize_answer(
+ q->manager,
+ q->question_utf8,
+ q->ifindex,
+ &answer);
- name = DNS_RESOURCE_KEY_NAME(q->question->keys[i]);
-
- if (is_localhost(name)) {
-
- r = synthesize_localhost_rr(q, q->question->keys[i], &answer);
- if (r < 0)
- return log_error_errno(r, "Failed to synthesize localhost RRs: %m");
-
- } else if (manager_is_own_hostname(q->manager, name)) {
+ if (r <= 0)
+ return r;
- r = synthesize_system_hostname_rr(q, q->question->keys[i], &answer);
- if (r < 0)
- return log_error_errno(r, "Failed to synthesize system hostname RRs: %m");
+ dns_query_reset_answer(q);
- } else if (is_gateway_hostname(name)) {
+ q->answer = answer;
+ answer = NULL;
+ q->answer_rcode = DNS_RCODE_SUCCESS;
+ q->answer_protocol = dns_synthesize_protocol(q->flags);
+ q->answer_family = dns_synthesize_family(q->flags);
+ q->answer_authenticated = true;
- r = synthesize_gateway_rr(q, q->question->keys[i], &answer);
- if (r < 0)
- return log_error_errno(r, "Failed to synthesize gateway RRs: %m");
+ *state = DNS_TRANSACTION_SUCCESS;
- } else if ((dns_name_endswith(name, "127.in-addr.arpa") > 0 && dns_name_equal(name, "2.0.0.127.in-addr.arpa") == 0) ||
- dns_name_equal(name, "1.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.ip6.arpa") > 0) {
+ return 1;
+}
- r = synthesize_localhost_ptr(q, q->question->keys[i], &answer);
- if (r < 0)
- return log_error_errno(r, "Failed to synthesize localhost PTR RRs: %m");
+static int dns_query_try_etc_hosts(DnsQuery *q) {
+ _cleanup_(dns_answer_unrefp) DnsAnswer *answer = NULL;
+ int r;
- } else if (dns_name_address(name, &af, &address) > 0) {
+ assert(q);
- r = synthesize_system_hostname_ptr(q, af, &address, &answer);
- if (r < 0)
- return log_error_errno(r, "Failed to synthesize system hostname PTR RR: %m");
+ /* Looks in /etc/hosts for matching entries. Note that this is done *before* the normal lookup is done. The
+ * data from /etc/hosts hence takes precedence over the network. */
- r = synthesize_gateway_ptr(q, af, &address, &answer);
- if (r < 0)
- return log_error_errno(r, "Failed to synthesize gateway hostname PTR RR: %m");
- }
- }
+ r = manager_etc_hosts_lookup(
+ q->manager,
+ q->question_utf8,
+ &answer);
+ if (r <= 0)
+ return r;
- if (!answer)
- return 0;
+ dns_query_reset_answer(q);
- dns_answer_unref(q->answer);
q->answer = answer;
answer = NULL;
-
q->answer_rcode = DNS_RCODE_SUCCESS;
- q->answer_protocol = SYNTHESIZE_PROTOCOL(q->flags);
- q->answer_family = SYNTHESIZE_FAMILY(q->flags);
-
- *state = DNS_TRANSACTION_SUCCESS;
+ q->answer_protocol = dns_synthesize_protocol(q->flags);
+ q->answer_family = dns_synthesize_family(q->flags);
+ q->answer_authenticated = true;
return 1;
}
@@ -879,7 +671,6 @@ int dns_query_go(DnsQuery *q) {
DnsScopeMatch found = DNS_SCOPE_NO;
DnsScope *s, *first = NULL;
DnsQueryCandidate *c;
- const char *name;
int r;
assert(q);
@@ -887,13 +678,21 @@ int dns_query_go(DnsQuery *q) {
if (q->state != DNS_TRANSACTION_NULL)
return 0;
- assert(q->question);
- assert(q->question->n_keys > 0);
-
- name = dns_question_first_name(q->question);
+ r = dns_query_try_etc_hosts(q);
+ if (r < 0)
+ return r;
+ if (r > 0) {
+ dns_query_complete(q, DNS_TRANSACTION_SUCCESS);
+ return 1;
+ }
LIST_FOREACH(scopes, s, q->manager->dns_scopes) {
DnsScopeMatch match;
+ const char *name;
+
+ name = dns_question_first_name(dns_query_question_for_protocol(q, s->protocol));
+ if (!name)
+ continue;
match = dns_scope_good_domain(s, q->ifindex, q->flags, name);
if (match < 0)
@@ -918,7 +717,10 @@ int dns_query_go(DnsQuery *q) {
if (found == DNS_SCOPE_NO) {
DnsTransactionState state = DNS_TRANSACTION_NO_SERVERS;
- dns_query_synthesize_reply(q, &state);
+ r = dns_query_synthesize_reply(q, &state);
+ if (r < 0)
+ return r;
+
dns_query_complete(q, state);
return 1;
}
@@ -929,6 +731,11 @@ int dns_query_go(DnsQuery *q) {
LIST_FOREACH(scopes, s, first->scopes_next) {
DnsScopeMatch match;
+ const char *name;
+
+ name = dns_question_first_name(dns_query_question_for_protocol(q, s->protocol));
+ if (!name)
+ continue;
match = dns_scope_good_domain(s, q->ifindex, q->flags, name);
if (match < 0)
@@ -942,10 +749,7 @@ int dns_query_go(DnsQuery *q) {
goto fail;
}
- q->answer = dns_answer_unref(q->answer);
- q->answer_rcode = 0;
- q->answer_family = AF_UNSPEC;
- q->answer_protocol = _DNS_PROTOCOL_INVALID;
+ dns_query_reset_answer(q);
r = sd_event_add_time(
q->manager->event,
@@ -956,6 +760,8 @@ int dns_query_go(DnsQuery *q) {
if (r < 0)
goto fail;
+ (void) sd_event_source_set_description(q->timeout_event_source, "query-timeout");
+
q->state = DNS_TRANSACTION_PENDING;
q->block_ready++;
@@ -981,6 +787,7 @@ fail:
static void dns_query_accept(DnsQuery *q, DnsQueryCandidate *c) {
DnsTransactionState state = DNS_TRANSACTION_NO_SERVERS;
bool has_authenticated = false, has_non_authenticated = false;
+ DnssecResult dnssec_result_authenticated = _DNSSEC_RESULT_INVALID, dnssec_result_non_authenticated = _DNSSEC_RESULT_INVALID;
DnsTransaction *t;
Iterator i;
int r;
@@ -988,11 +795,23 @@ static void dns_query_accept(DnsQuery *q, DnsQueryCandidate *c) {
assert(q);
if (!c) {
- dns_query_synthesize_reply(q, &state);
+ r = dns_query_synthesize_reply(q, &state);
+ if (r < 0)
+ goto fail;
+
dns_query_complete(q, state);
return;
}
+ if (c->error_code != 0) {
+ /* If the candidate had an error condition of its own, start with that. */
+ state = DNS_TRANSACTION_ERRNO;
+ q->answer = dns_answer_unref(q->answer);
+ q->answer_rcode = 0;
+ q->answer_dnssec_result = _DNSSEC_RESULT_INVALID;
+ q->answer_errno = c->error_code;
+ }
+
SET_FOREACH(t, c->transactions, i) {
switch (t->state) {
@@ -1000,16 +819,19 @@ static void dns_query_accept(DnsQuery *q, DnsQueryCandidate *c) {
case DNS_TRANSACTION_SUCCESS: {
/* We found a successfuly reply, merge it into the answer */
r = dns_answer_extend(&q->answer, t->answer);
- if (r < 0) {
- dns_query_complete(q, DNS_TRANSACTION_RESOURCES);
- return;
- }
+ if (r < 0)
+ goto fail;
+
q->answer_rcode = t->answer_rcode;
+ q->answer_errno = 0;
- if (t->answer_authenticated)
+ if (t->answer_authenticated) {
has_authenticated = true;
- else
+ dnssec_result_authenticated = t->answer_dnssec_result;
+ } else {
has_non_authenticated = true;
+ dnssec_result_non_authenticated = t->answer_dnssec_result;
+ }
state = DNS_TRANSACTION_SUCCESS;
break;
@@ -1026,28 +848,40 @@ static void dns_query_accept(DnsQuery *q, DnsQueryCandidate *c) {
/* Any kind of failure? Store the data away,
* if there's nothing stored yet. */
- if (state != DNS_TRANSACTION_SUCCESS) {
-
- dns_answer_unref(q->answer);
- q->answer = dns_answer_ref(t->answer);
- q->answer_rcode = t->answer_rcode;
+ if (state == DNS_TRANSACTION_SUCCESS)
+ continue;
- state = t->state;
- }
+ q->answer = dns_answer_unref(q->answer);
+ q->answer_rcode = t->answer_rcode;
+ q->answer_dnssec_result = t->answer_dnssec_result;
+ q->answer_errno = t->answer_errno;
+ state = t->state;
break;
}
}
+ if (state == DNS_TRANSACTION_SUCCESS) {
+ q->answer_authenticated = has_authenticated && !has_non_authenticated;
+ q->answer_dnssec_result = q->answer_authenticated ? dnssec_result_authenticated : dnssec_result_non_authenticated;
+ }
+
q->answer_protocol = c->scope->protocol;
q->answer_family = c->scope->family;
- q->answer_authenticated = has_authenticated && !has_non_authenticated;
dns_search_domain_unref(q->answer_search_domain);
q->answer_search_domain = dns_search_domain_ref(c->search_domain);
- dns_query_synthesize_reply(q, &state);
+ r = dns_query_synthesize_reply(q, &state);
+ if (r < 0)
+ goto fail;
+
dns_query_complete(q, state);
+ return;
+
+fail:
+ q->answer_errno = -r;
+ dns_query_complete(q, DNS_TRANSACTION_ERRNO);
}
void dns_query_ready(DnsQuery *q) {
@@ -1100,26 +934,61 @@ void dns_query_ready(DnsQuery *q) {
}
static int dns_query_cname_redirect(DnsQuery *q, const DnsResourceRecord *cname) {
- _cleanup_(dns_question_unrefp) DnsQuestion *nq = NULL;
- int r;
+ _cleanup_(dns_question_unrefp) DnsQuestion *nq_idna = NULL, *nq_utf8 = NULL;
+ int r, k;
assert(q);
- log_debug("Following CNAME %s → %s", dns_question_first_name(q->question), cname->cname.name);
-
q->n_cname_redirects ++;
if (q->n_cname_redirects > CNAME_MAX)
return -ELOOP;
- r = dns_question_cname_redirect(q->question, cname, &nq);
+ r = dns_question_cname_redirect(q->question_idna, cname, &nq_idna);
if (r < 0)
return r;
+ else if (r > 0)
+ log_debug("Following CNAME/DNAME %s → %s.", dns_question_first_name(q->question_idna), dns_question_first_name(nq_idna));
- dns_question_unref(q->question);
- q->question = nq;
- nq = NULL;
+ k = dns_question_is_equal(q->question_idna, q->question_utf8);
+ if (k < 0)
+ return r;
+ if (k > 0) {
+ /* Same question? Shortcut new question generation */
+ nq_utf8 = dns_question_ref(nq_idna);
+ k = r;
+ } else {
+ k = dns_question_cname_redirect(q->question_utf8, cname, &nq_utf8);
+ if (k < 0)
+ return k;
+ else if (k > 0)
+ log_debug("Following UTF8 CNAME/DNAME %s → %s.", dns_question_first_name(q->question_utf8), dns_question_first_name(nq_utf8));
+ }
+
+ if (r == 0 && k == 0) /* No actual cname happened? */
+ return -ELOOP;
+
+ if (q->answer_protocol == DNS_PROTOCOL_DNS) {
+ /* Don't permit CNAME redirects from unicast DNS to LLMNR or MulticastDNS, so that global resources
+ * cannot invade the local namespace. The opposite way we permit: local names may redirect to global
+ * ones. */
+
+ q->flags &= ~(SD_RESOLVED_LLMNR|SD_RESOLVED_MDNS); /* mask away the local protocols */
+ }
+
+ /* Turn off searching for the new name */
+ q->flags |= SD_RESOLVED_NO_SEARCH;
+
+ dns_question_unref(q->question_idna);
+ q->question_idna = nq_idna;
+ nq_idna = NULL;
+
+ dns_question_unref(q->question_utf8);
+ q->question_utf8 = nq_utf8;
+ nq_utf8 = NULL;
+
+ dns_query_free_candidates(q);
+ dns_query_reset_answer(q);
- dns_query_stop(q);
q->state = DNS_TRANSACTION_NULL;
return 0;
@@ -1127,23 +996,25 @@ static int dns_query_cname_redirect(DnsQuery *q, const DnsResourceRecord *cname)
int dns_query_process_cname(DnsQuery *q) {
_cleanup_(dns_resource_record_unrefp) DnsResourceRecord *cname = NULL;
+ DnsQuestion *question;
DnsResourceRecord *rr;
int r;
assert(q);
- if (q->state != DNS_TRANSACTION_SUCCESS)
- return 0;
+ if (!IN_SET(q->state, DNS_TRANSACTION_SUCCESS, DNS_TRANSACTION_NULL))
+ return DNS_QUERY_NOMATCH;
- DNS_ANSWER_FOREACH(rr, q->answer) {
+ question = dns_query_question_for_protocol(q, q->answer_protocol);
- r = dns_question_matches_rr(q->question, rr, DNS_SEARCH_DOMAIN_NAME(q->answer_search_domain));
+ DNS_ANSWER_FOREACH(rr, q->answer) {
+ r = dns_question_matches_rr(question, rr, DNS_SEARCH_DOMAIN_NAME(q->answer_search_domain));
if (r < 0)
return r;
if (r > 0)
- return 0; /* The answer matches directly, no need to follow cnames */
+ return DNS_QUERY_MATCH; /* The answer matches directly, no need to follow cnames */
- r = dns_question_matches_cname(q->question, rr, DNS_SEARCH_DOMAIN_NAME(q->answer_search_domain));
+ r = dns_question_matches_cname_or_dname(question, rr, DNS_SEARCH_DOMAIN_NAME(q->answer_search_domain));
if (r < 0)
return r;
if (r > 0 && !cname)
@@ -1151,7 +1022,7 @@ int dns_query_process_cname(DnsQuery *q) {
}
if (!cname)
- return 0; /* No cname to follow */
+ return DNS_QUERY_NOMATCH; /* No match and no cname to follow */
if (q->flags & SD_RESOLVED_NO_CNAME)
return -ELOOP;
@@ -1163,20 +1034,16 @@ int dns_query_process_cname(DnsQuery *q) {
/* Let's see if the answer can already answer the new
* redirected question */
- DNS_ANSWER_FOREACH(rr, q->answer) {
- r = dns_question_matches_rr(q->question, rr, NULL);
- if (r < 0)
- return r;
- if (r > 0)
- return 0; /* It can answer it, yay! */
- }
+ r = dns_query_process_cname(q);
+ if (r != DNS_QUERY_NOMATCH)
+ return r;
/* OK, it cannot, let's begin with the new query */
r = dns_query_go(q);
if (r < 0)
return r;
- return 1; /* We return > 0, if we restarted the query for a new cname */
+ return DNS_QUERY_RESTARTED; /* We restarted the query for a new cname */
}
static int on_bus_track(sd_bus_track *t, void *userdata) {
@@ -1208,3 +1075,42 @@ int dns_query_bus_track(DnsQuery *q, sd_bus_message *m) {
return 0;
}
+
+DnsQuestion* dns_query_question_for_protocol(DnsQuery *q, DnsProtocol protocol) {
+ assert(q);
+
+ switch (protocol) {
+
+ case DNS_PROTOCOL_DNS:
+ return q->question_idna;
+
+ case DNS_PROTOCOL_MDNS:
+ case DNS_PROTOCOL_LLMNR:
+ return q->question_utf8;
+
+ default:
+ return NULL;
+ }
+}
+
+const char *dns_query_string(DnsQuery *q) {
+ const char *name;
+ int r;
+
+ /* Returns a somewhat useful human-readable lookup key string for this query */
+
+ if (q->request_address_string)
+ return q->request_address_string;
+
+ if (q->request_address_valid) {
+ r = in_addr_to_string(q->request_family, &q->request_address, &q->request_address_string);
+ if (r >= 0)
+ return q->request_address_string;
+ }
+
+ name = dns_question_first_name(q->question_utf8);
+ if (name)
+ return name;
+
+ return dns_question_first_name(q->question_idna);
+}
generated by cgit v1.2.3-54-g00ecf (git 2.45.2) at 2025-02-24 14:51:04 +0000