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-rw-r--r--src/resolve/resolved-bus.c150
-rw-r--r--src/resolve/resolved-dns-packet.c2
-rw-r--r--src/resolve/resolved-dns-packet.h2
-rw-r--r--src/resolve/resolved-dns-query.c247
-rw-r--r--src/resolve/resolved-dns-query.h12
-rw-r--r--src/shared/bus-errors.h1
6 files changed, 297 insertions, 117 deletions
diff --git a/src/resolve/resolved-bus.c b/src/resolve/resolved-bus.c
index 64bb9ac889..ebb97d7fd3 100644
--- a/src/resolve/resolved-bus.c
+++ b/src/resolve/resolved-bus.c
@@ -82,15 +82,55 @@ static int reply_query_state(DnsQuery *q) {
}
case DNS_QUERY_NULL:
- case DNS_QUERY_SENT:
+ case DNS_QUERY_PENDING:
case DNS_QUERY_SUCCESS:
+ default:
assert_not_reached("Impossible state");
}
}
+static int append_address(sd_bus_message *reply, DnsResourceRecord *rr, int ifindex) {
+ int r;
+
+ assert(reply);
+ assert(rr);
+
+ r = sd_bus_message_open_container(reply, 'r', "yayi");
+ if (r < 0)
+ return r;
+
+ if (rr->key.type == DNS_TYPE_A) {
+ r = sd_bus_message_append(reply, "y", AF_INET);
+ if (r < 0)
+ return r;
+
+ r = sd_bus_message_append_array(reply, 'y', &rr->a.in_addr, sizeof(struct in_addr));
+ } else {
+ r = sd_bus_message_append(reply, "y", AF_INET6);
+ if (r < 0)
+ return r;
+
+ r = sd_bus_message_append_array(reply, 'y', &rr->aaaa.in6_addr, sizeof(struct in6_addr));
+ }
+ if (r < 0)
+ return r;
+
+ r = sd_bus_message_append(reply, "i", ifindex);
+ if (r < 0)
+ return r;
+
+ r = sd_bus_message_close_container(reply);
+ if (r < 0)
+ return r;
+
+ return 0;
+}
+
static void bus_method_resolve_hostname_complete(DnsQuery *q) {
+ _cleanup_(dns_resource_record_unrefp) DnsResourceRecord *cname = NULL;
_cleanup_bus_message_unref_ sd_bus_message *reply = NULL;
unsigned i, n, added = 0;
+ size_t answer_rindex;
int r;
assert(q);
@@ -106,6 +146,8 @@ static void bus_method_resolve_hostname_complete(DnsQuery *q) {
if (r < 0)
goto parse_fail;
+ answer_rindex = q->received->rindex;
+
r = sd_bus_message_new_method_return(q->request, &reply);
if (r < 0)
goto finish;
@@ -117,6 +159,7 @@ static void bus_method_resolve_hostname_complete(DnsQuery *q) {
n = DNS_PACKET_ANCOUNT(q->received) +
DNS_PACKET_NSCOUNT(q->received) +
DNS_PACKET_ARCOUNT(q->received);
+
for (i = 0; i < n; i++) {
_cleanup_(dns_resource_record_unrefp) DnsResourceRecord *rr = NULL;
@@ -124,50 +167,79 @@ static void bus_method_resolve_hostname_complete(DnsQuery *q) {
if (r < 0)
goto parse_fail;
- if (rr->key.class != DNS_CLASS_IN)
- continue;
-
- if (!(q->request_family != AF_INET6 && rr->key.type == DNS_TYPE_A) &&
- !(q->request_family != AF_INET && rr->key.type == DNS_TYPE_AAAA))
- continue;
+ r = dns_query_matches_rr(q, rr);
+ if (r < 0)
+ goto parse_fail;
+ if (r == 0) {
+ /* Hmm, if this is not an address record,
+ maybe it's a cname? If so, remember this */
+ r = dns_query_matches_cname(q, rr);
+ if (r < 0)
+ goto parse_fail;
+ if (r > 0)
+ cname = dns_resource_record_ref(rr);
- if (!dns_name_equal(rr->key.name, q->request_hostname))
continue;
+ }
- r = sd_bus_message_open_container(reply, 'r', "yayi");
+ r = append_address(reply, rr, q->received->ifindex);
if (r < 0)
goto finish;
- if (rr->key.type == DNS_TYPE_A) {
- r = sd_bus_message_append(reply, "y", AF_INET);
- if (r < 0)
- goto finish;
-
- r = sd_bus_message_append_array(reply, 'y', &rr->a.in_addr, sizeof(struct in_addr));
- } else {
- r = sd_bus_message_append(reply, "y", AF_INET6);
- if (r < 0)
- goto finish;
+ added ++;
+ }
- r = sd_bus_message_append_array(reply, 'y', &rr->aaaa.in6_addr, sizeof(struct in6_addr));
- }
- if (r < 0)
+ if (added <= 0) {
+ if (!cname) {
+ r = sd_bus_reply_method_errorf(q->request, BUS_ERROR_NO_SUCH_RR, "'%s' does not have RR of this type", q->request_hostname);
goto finish;
+ }
- r = sd_bus_message_append(reply, "i", q->received->ifindex);
- if (r < 0)
- goto finish;
+ /* This has a cname? Then update the query with the
+ * new cname. */
+ r = dns_query_follow_cname(q, cname->cname.name);
+ if (r < 0) {
+ if (r == -ELOOP)
+ r = sd_bus_reply_method_errorf(q->request, BUS_ERROR_CNAME_LOOP, "CNAME loop on '%s'", q->request_hostname);
+ else
+ r = sd_bus_reply_method_errno(q->request, -r, NULL);
- r = sd_bus_message_close_container(reply);
- if (r < 0)
goto finish;
+ }
- added ++;
- }
+ /* Before we restart the query, let's see if any of
+ * the RRs we already got already answers our query */
+ dns_packet_rewind(q->received, answer_rindex);
+ for (i = 0; i < n; i++) {
+ _cleanup_(dns_resource_record_unrefp) DnsResourceRecord *rr = NULL;
- if (added <= 0) {
- r = sd_bus_reply_method_errorf(q->request, BUS_ERROR_NO_SUCH_RR, "'%s' does not have RR of this type", q->request_hostname);
- goto finish;
+ r = dns_packet_read_rr(q->received, &rr, NULL);
+ if (r < 0)
+ goto parse_fail;
+
+ r = dns_query_matches_rr(q, rr);
+ if (r < 0)
+ goto parse_fail;
+ if (r == 0)
+ continue;
+
+ r = append_address(reply, rr, q->received->ifindex);
+ if (r < 0)
+ goto finish;
+
+ added++;
+ }
+
+ /* If we didn't find anything, then let's restart the
+ * query, this time with the cname */
+ if (added <= 0) {
+ r = dns_query_start(q);
+ if (r < 0) {
+ r = sd_bus_reply_method_errno(q->request, -r, NULL);
+ goto finish;
+ }
+ return;
+ }
}
r = sd_bus_message_close_container(reply);
@@ -245,7 +317,6 @@ static int bus_method_resolve_hostname(sd_bus *bus, sd_bus_message *message, voi
static void bus_method_resolve_address_complete(DnsQuery *q) {
_cleanup_bus_message_unref_ sd_bus_message *reply = NULL;
unsigned i, n, added = 0;
- _cleanup_free_ char *reverse = NULL;
int r;
assert(q);
@@ -257,10 +328,6 @@ static void bus_method_resolve_address_complete(DnsQuery *q) {
assert(q->received);
- r = dns_name_reverse(q->request_family, &q->request_address, &reverse);
- if (r < 0)
- goto finish;
-
r = dns_packet_skip_question(q->received);
if (r < 0)
goto parse_fail;
@@ -284,11 +351,10 @@ static void bus_method_resolve_address_complete(DnsQuery *q) {
if (r < 0)
goto parse_fail;
- if (rr->key.class != DNS_CLASS_IN)
- continue;
- if (rr->key.type != DNS_TYPE_PTR)
- continue;
- if (!dns_name_equal(rr->key.name, reverse))
+ r = dns_query_matches_rr(q, rr);
+ if (r < 0)
+ goto parse_fail;
+ if (r == 0)
continue;
r = sd_bus_message_append(reply, "s", rr->ptr.name);
diff --git a/src/resolve/resolved-dns-packet.c b/src/resolve/resolved-dns-packet.c
index af296f63ac..5597ffd969 100644
--- a/src/resolve/resolved-dns-packet.c
+++ b/src/resolve/resolved-dns-packet.c
@@ -395,7 +395,7 @@ int dns_packet_read(DnsPacket *p, size_t sz, const void **ret, size_t *start) {
return 0;
}
-static void dns_packet_rewind(DnsPacket *p, size_t idx) {
+void dns_packet_rewind(DnsPacket *p, size_t idx) {
assert(p);
assert(idx <= p->size);
assert(idx >= DNS_PACKET_HEADER_SIZE);
diff --git a/src/resolve/resolved-dns-packet.h b/src/resolve/resolved-dns-packet.h
index d4c9c475f5..99f60a1556 100644
--- a/src/resolve/resolved-dns-packet.h
+++ b/src/resolve/resolved-dns-packet.h
@@ -116,6 +116,8 @@ int dns_packet_read_name(DnsPacket *p, char **ret, size_t *start);
int dns_packet_read_key(DnsPacket *p, DnsResourceKey *ret, size_t *start);
int dns_packet_read_rr(DnsPacket *p, DnsResourceRecord **ret, size_t *start);
+void dns_packet_rewind(DnsPacket *p, size_t idx);
+
int dns_packet_skip_question(DnsPacket *p);
enum {
diff --git a/src/resolve/resolved-dns-query.c b/src/resolve/resolved-dns-query.c
index 5bd5920254..6e04324da5 100644
--- a/src/resolve/resolved-dns-query.c
+++ b/src/resolve/resolved-dns-query.c
@@ -25,6 +25,9 @@
#define TRANSACTION_TIMEOUT_USEC (5 * USEC_PER_SEC)
#define QUERY_TIMEOUT_USEC (30 * USEC_PER_SEC)
#define ATTEMPTS_MAX 8
+#define CNAME_MAX 8
+
+static int dns_query_transaction_start(DnsQueryTransaction *t);
DnsQueryTransaction* dns_query_transaction_free(DnsQueryTransaction *t) {
if (!t)
@@ -110,7 +113,7 @@ static void dns_query_transaction_set_state(DnsQueryTransaction *t, DnsQueryStat
t->state = state;
- if (state != DNS_QUERY_SENT) {
+ if (state != DNS_QUERY_PENDING) {
dns_query_transaction_stop(t);
dns_query_finish(t->query);
}
@@ -248,7 +251,7 @@ void dns_query_transaction_reply(DnsQueryTransaction *t, DnsPacket *p) {
assert(t);
assert(p);
- if (t->state != DNS_QUERY_SENT)
+ if (t->state != DNS_QUERY_PENDING)
return;
if (t->received != p) {
@@ -273,8 +276,21 @@ void dns_query_transaction_reply(DnsQueryTransaction *t, DnsPacket *p) {
if (DNS_PACKET_TC(p)) {
/* Response was truncated, let's try again with good old TCP */
r = dns_query_transaction_start_tcp(t);
+ if (r == -ESRCH) {
+ /* No servers found? Damn! */
+ dns_query_transaction_set_state(t, DNS_QUERY_NO_SERVERS);
+ return;
+ }
if (r < 0) {
- dns_query_transaction_set_state(t, DNS_QUERY_RESOURCES);
+ /* Couldn't send? Try immediately again, with a new server */
+ dns_scope_next_dns_server(t->scope);
+
+ r = dns_query_transaction_start(t);
+ if (r < 0) {
+ dns_query_transaction_set_state(t, DNS_QUERY_RESOURCES);
+ return;
+ }
+
return;
}
}
@@ -331,7 +347,7 @@ static int dns_query_make_packet(DnsQueryTransaction *t) {
return 0;
}
-int dns_query_transaction_start(DnsQueryTransaction *t) {
+static int dns_query_transaction_start(DnsQueryTransaction *t) {
int r;
assert(t);
@@ -342,12 +358,14 @@ int dns_query_transaction_start(DnsQueryTransaction *t) {
dns_query_transaction_set_state(t, DNS_QUERY_ATTEMPTS_MAX);
return 0;
}
- t->n_attempts++;
r = dns_query_make_packet(t);
if (r < 0)
return r;
+ t->n_attempts++;
+ t->received = dns_packet_unref(t->received);
+
/* Try via UDP, and if that fails due to large size try via TCP */
r = dns_scope_send(t->scope, t->sent);
if (r == -EMSGSIZE)
@@ -368,7 +386,7 @@ int dns_query_transaction_start(DnsQueryTransaction *t) {
if (r < 0)
return r;
- dns_query_transaction_set_state(t, DNS_QUERY_SENT);
+ dns_query_transaction_set_state(t, DNS_QUERY_PENDING);
return 1;
}
@@ -398,10 +416,7 @@ DnsQuery *dns_query_free(DnsQuery *q) {
int dns_query_new(Manager *m, DnsQuery **ret, DnsResourceKey *keys, unsigned n_keys) {
_cleanup_(dns_query_freep) DnsQuery *q = NULL;
- DnsScope *s, *first = NULL;
- DnsScopeMatch found = DNS_SCOPE_NO;
const char *name = NULL;
- int n, r;
assert(m);
@@ -434,10 +449,67 @@ int dns_query_new(Manager *m, DnsQuery **ret, DnsResourceKey *keys, unsigned n_k
LIST_PREPEND(queries, m->dns_queries, q);
q->manager = m;
- LIST_FOREACH(scopes, s, m->dns_scopes) {
+ if (ret)
+ *ret = q;
+ q = NULL;
+
+ return 0;
+}
+
+static void dns_query_stop(DnsQuery *q) {
+ assert(q);
+
+ q->timeout_event_source = sd_event_source_unref(q->timeout_event_source);
+
+ while (q->transactions)
+ dns_query_transaction_free(q->transactions);
+}
+
+static void dns_query_set_state(DnsQuery *q, DnsQueryState state) {
+ DnsQueryState old_state;
+ assert(q);
+
+ if (q->state == state)
+ return;
+
+ old_state = q->state;
+ q->state = state;
+
+ if (!IN_SET(state, DNS_QUERY_NULL, DNS_QUERY_PENDING)) {
+ dns_query_stop(q);
+
+ if (old_state == DNS_QUERY_PENDING && q->complete)
+ q->complete(q);
+ }
+}
+
+static int on_query_timeout(sd_event_source *s, usec_t usec, void *userdata) {
+ DnsQuery *q = userdata;
+
+ assert(s);
+ assert(q);
+
+ dns_query_set_state(q, DNS_QUERY_TIMEOUT);
+ return 0;
+}
+
+int dns_query_start(DnsQuery *q) {
+ DnsScopeMatch found = DNS_SCOPE_NO;
+ DnsScope *s, *first = NULL;
+ DnsQueryTransaction *t;
+ int r;
+
+ assert(q);
+
+ if (q->state != DNS_QUERY_NULL)
+ return 0;
+
+ assert(q->n_keys > 0);
+
+ LIST_FOREACH(scopes, s, q->manager->dns_scopes) {
DnsScopeMatch match;
- match = dns_scope_test(s, name);
+ match = dns_scope_test(s, q->keys[0].name);
if (match < 0)
return match;
@@ -458,17 +530,16 @@ int dns_query_new(Manager *m, DnsQuery **ret, DnsResourceKey *keys, unsigned n_k
}
if (found == DNS_SCOPE_NO)
- return -ENETDOWN;
+ return -ESRCH;
r = dns_query_transaction_new(q, NULL, first);
if (r < 0)
return r;
- n = 1;
LIST_FOREACH(scopes, s, first->scopes_next) {
DnsScopeMatch match;
- match = dns_scope_test(s, name);
+ match = dns_scope_test(s, q->keys[0].name);
if (match < 0)
return match;
@@ -478,62 +549,15 @@ int dns_query_new(Manager *m, DnsQuery **ret, DnsResourceKey *keys, unsigned n_k
r = dns_query_transaction_new(q, NULL, s);
if (r < 0)
return r;
-
- n++;
}
- if (ret)
- *ret = q;
- q = NULL;
-
- return n;
-}
-
-static void dns_query_set_state(DnsQuery *q, DnsQueryState state) {
- assert(q);
-
- if (q->state == state)
- return;
-
- q->state = state;
-
- if (state == DNS_QUERY_SENT)
- return;
-
- q->timeout_event_source = sd_event_source_unref(q->timeout_event_source);
-
- while (q->transactions)
- dns_query_transaction_free(q->transactions);
-
- if (q->complete)
- q->complete(q);
-}
-
-static int on_query_timeout(sd_event_source *s, usec_t usec, void *userdata) {
- DnsQuery *q = userdata;
-
- assert(s);
- assert(q);
-
- dns_query_set_state(q, DNS_QUERY_TIMEOUT);
- return 0;
-}
-
-int dns_query_start(DnsQuery *q) {
- DnsQueryTransaction *t;
- int r;
-
- assert(q);
- assert(q->state == DNS_QUERY_NULL);
-
- if (!q->transactions)
- return -ENETDOWN;
+ q->received = dns_packet_unref(q->received);
r = sd_event_add_time(q->manager->event, &q->timeout_event_source, CLOCK_MONOTONIC, now(CLOCK_MONOTONIC) + QUERY_TIMEOUT_USEC, 0, on_query_timeout, q);
if (r < 0)
goto fail;
- dns_query_set_state(q, DNS_QUERY_SENT);
+ dns_query_set_state(q, DNS_QUERY_PENDING);
LIST_FOREACH(transactions_by_query, t, q->transactions) {
@@ -541,16 +565,14 @@ int dns_query_start(DnsQuery *q) {
if (r < 0)
goto fail;
- if (q->state != DNS_QUERY_SENT)
+ if (q->state != DNS_QUERY_PENDING)
break;
}
- return 0;
+ return 1;
fail:
- while (q->transactions)
- dns_query_transaction_free(q->transactions);
-
+ dns_query_stop(q);
return r;
}
@@ -561,13 +583,13 @@ void dns_query_finish(DnsQuery *q) {
assert(q);
- if (q->state != DNS_QUERY_SENT)
+ if (q->state != DNS_QUERY_PENDING)
return;
LIST_FOREACH(transactions_by_query, t, q->transactions) {
/* One of the transactions is still going on, let's wait for it */
- if (t->state == DNS_QUERY_SENT || t->state == DNS_QUERY_NULL)
+ if (t->state == DNS_QUERY_PENDING || t->state == DNS_QUERY_NULL)
return;
/* One of the transactions is successful, let's use it */
@@ -595,3 +617,88 @@ void dns_query_finish(DnsQuery *q) {
dns_query_set_state(q, state);
}
+
+int dns_query_follow_cname(DnsQuery *q, const char *name) {
+ DnsResourceKey *keys;
+ unsigned i;
+
+ assert(q);
+
+ if (q->n_cname > CNAME_MAX)
+ return -ELOOP;
+
+ keys = new(DnsResourceKey, q->n_keys);
+ if (!keys)
+ return -ENOMEM;
+
+ for (i = 0; i < q->n_keys; i++) {
+ keys[i].class = q->keys[i].class;
+ keys[i].type = q->keys[i].type;
+ keys[i].name = strdup(name);
+ if (!keys[i].name) {
+
+ for (; i > 0; i--)
+ free(keys[i-1].name);
+ free(keys);
+ return -ENOMEM;
+ }
+ }
+
+ for (i = 0; i < q->n_keys; i++)
+ free(q->keys[i].name);
+ free(q->keys);
+
+ q->keys = keys;
+
+ q->n_cname++;
+
+ dns_query_set_state(q, DNS_QUERY_NULL);
+ return 0;
+}
+
+int dns_query_matches_rr(DnsQuery *q, DnsResourceRecord *rr) {
+ unsigned i;
+ int r;
+
+ assert(q);
+ assert(rr);
+
+ for (i = 0; i < q->n_keys; i++) {
+
+ if (rr->key.class != q->keys[i].class)
+ continue;
+
+ if (rr->key.type != q->keys[i].type &&
+ q->keys[i].type != DNS_TYPE_ANY)
+ continue;
+
+ r = dns_name_equal(rr->key.name, q->keys[i].name);
+ if (r != 0)
+ return r;
+ }
+
+ return 0;
+}
+
+int dns_query_matches_cname(DnsQuery *q, DnsResourceRecord *rr) {
+ unsigned i;
+ int r;
+
+ assert(q);
+ assert(rr);
+
+ for (i = 0; i < q->n_keys; i++) {
+
+ if (rr->key.class != q->keys[i].class)
+ continue;
+
+ if (rr->key.type != DNS_TYPE_CNAME)
+ continue;
+
+ r = dns_name_equal(rr->key.name, q->keys[i].name);
+ if (r != 0)
+ return r;
+ }
+
+ return 0;
+}
diff --git a/src/resolve/resolved-dns-query.h b/src/resolve/resolved-dns-query.h
index d5bc08dc30..864036acc7 100644
--- a/src/resolve/resolved-dns-query.h
+++ b/src/resolve/resolved-dns-query.h
@@ -36,14 +36,14 @@ typedef struct DnsQueryTransaction DnsQueryTransaction;
typedef enum DnsQueryState {
DNS_QUERY_NULL,
- DNS_QUERY_SENT,
+ DNS_QUERY_PENDING,
DNS_QUERY_FAILURE,
DNS_QUERY_SUCCESS,
DNS_QUERY_NO_SERVERS,
DNS_QUERY_TIMEOUT,
DNS_QUERY_ATTEMPTS_MAX,
DNS_QUERY_INVALID_REPLY,
- DNS_QUERY_RESOURCES,
+ DNS_QUERY_RESOURCES
} DnsQueryState;
struct DnsQueryTransaction {
@@ -75,11 +75,13 @@ struct DnsQuery {
unsigned n_keys;
DnsQueryState state;
+ unsigned n_cname;
sd_event_source *timeout_event_source;
DnsPacket *received;
+ /* Bus client information */
sd_bus_message *request;
unsigned char request_family;
const char *request_hostname;
@@ -94,10 +96,12 @@ struct DnsQuery {
int dns_query_new(Manager *m, DnsQuery **q, DnsResourceKey *keys, unsigned n_keys);
DnsQuery *dns_query_free(DnsQuery *q);
int dns_query_start(DnsQuery *q);
-void dns_query_finish(DnsQuery *q);
+int dns_query_follow_cname(DnsQuery *q, const char *name);
+int dns_query_matches_rr(DnsQuery *q, DnsResourceRecord *rr);
+int dns_query_matches_cname(DnsQuery *q, DnsResourceRecord *rr);
DnsQueryTransaction* dns_query_transaction_free(DnsQueryTransaction *t);
-int dns_query_transaction_start(DnsQueryTransaction *t);
void dns_query_transaction_reply(DnsQueryTransaction *t, DnsPacket *p);
+void dns_query_finish(DnsQuery *q);
DEFINE_TRIVIAL_CLEANUP_FUNC(DnsQuery*, dns_query_free);
diff --git a/src/shared/bus-errors.h b/src/shared/bus-errors.h
index f3d973507e..e4d0d435a5 100644
--- a/src/shared/bus-errors.h
+++ b/src/shared/bus-errors.h
@@ -64,4 +64,5 @@
#define BUS_ERROR_INVALID_REPLY "org.freedesktop.resolve1.InvalidReply"
#define BUS_ERROR_NO_SUCH_RR "org.freedesktop.resolve1.NoSuchRR"
#define BUS_ERROR_NO_RESOURCES "org.freedesktop.resolve1.NoResources"
+#define BUS_ERROR_CNAME_LOOP "org.freedesktop.resolve1.CNameLoop"
#define _BUS_ERROR_DNS "org.freedesktop.resolve1.DnsError."
generated by cgit v1.2.3-54-g00ecf (git 2.45.2) at 2024-11-06 05:32:26 +0000