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authorLennart Poettering <lennart@poettering.net>2014-07-16 20:15:47 +0200
committerLennart Poettering <lennart@poettering.net>2014-07-16 20:15:47 +0200
commitad867662936a4c7ab2c7116d804c272338801231 (patch)
treea7583840a30702971f5c38b31a12fe7cb69c2fd6 /src/resolve
parentc73ce96b569e2f10dff64b7dc0bd271972674c2a (diff)
resolved: support for TCP DNS queries
Diffstat (limited to 'src/resolve')
-rw-r--r--src/resolve/resolved-bus.c317
-rw-r--r--src/resolve/resolved-dns-packet.h1
-rw-r--r--src/resolve/resolved-dns-query.c270
-rw-r--r--src/resolve/resolved-dns-query.h16
-rw-r--r--src/resolve/resolved-dns-scope.c57
-rw-r--r--src/resolve/resolved-dns-scope.h2
-rw-r--r--src/resolve/resolved-manager.c10
7 files changed, 454 insertions, 219 deletions
diff --git a/src/resolve/resolved-bus.c b/src/resolve/resolved-bus.c
index 02e971dbf3..64bb9ac889 100644
--- a/src/resolve/resolved-bus.c
+++ b/src/resolve/resolved-bus.c
@@ -25,141 +25,161 @@
#include "resolved.h"
#include "resolved-dns-domain.h"
-static void bus_method_resolve_hostname_complete(DnsQuery *q) {
+static int reply_query_state(DnsQuery *q) {
+ _cleanup_free_ char *ip = NULL;
+ const char *name;
int r;
- assert(q);
+ if (q->request_hostname)
+ name = q->request_hostname;
+ else {
+ r = in_addr_to_string(q->request_family, &q->request_address, &ip);
+ if (r < 0)
+ return r;
+
+ name = ip;
+ }
- switch(q->state) {
+ switch (q->state) {
- case DNS_QUERY_SKIPPED:
- r = sd_bus_reply_method_errorf(q->request, BUS_ERROR_NO_NAME_SERVERS, "Not appropriate name servers or networks found");
- break;
+ case DNS_QUERY_NO_SERVERS:
+ return sd_bus_reply_method_errorf(q->request, BUS_ERROR_NO_NAME_SERVERS, "Not appropriate name servers or networks found");
case DNS_QUERY_TIMEOUT:
- r = sd_bus_reply_method_errorf(q->request, SD_BUS_ERROR_TIMEOUT, "Query timed out");
- break;
+ return sd_bus_reply_method_errorf(q->request, SD_BUS_ERROR_TIMEOUT, "Query timed out");
case DNS_QUERY_ATTEMPTS_MAX:
- r = sd_bus_reply_method_errorf(q->request, SD_BUS_ERROR_TIMEOUT, "All attempts to contact name servers or networks failed");
- break;
+ return sd_bus_reply_method_errorf(q->request, SD_BUS_ERROR_TIMEOUT, "All attempts to contact name servers or networks failed");
+
+ case DNS_QUERY_RESOURCES:
+ return sd_bus_reply_method_errorf(q->request, BUS_ERROR_NO_RESOURCES, "Not enough resources");
+
+ case DNS_QUERY_INVALID_REPLY:
+ return sd_bus_reply_method_errorf(q->request, BUS_ERROR_INVALID_REPLY, "Received invalid reply");
case DNS_QUERY_FAILURE: {
_cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL;
- if (q->rcode == DNS_RCODE_NXDOMAIN)
- sd_bus_error_setf(&error, _BUS_ERROR_DNS "NXDOMAIN", "Hostname %s does not exist", q->request_hostname);
+ assert(q->received);
+
+ if (DNS_PACKET_RCODE(q->received) == DNS_RCODE_NXDOMAIN)
+ sd_bus_error_setf(&error, _BUS_ERROR_DNS "NXDOMAIN", "'%s' not found", name);
else {
const char *rc, *n;
- char p[DECIMAL_STR_MAX(q->rcode)];
+ char p[3]; /* the rcode is 4 bits long */
- rc = dns_rcode_to_string(q->rcode);
+ rc = dns_rcode_to_string(DNS_PACKET_RCODE(q->received));
if (!rc) {
- sprintf(p, "%i", q->rcode);
+ sprintf(p, "%i", DNS_PACKET_RCODE(q->received));
rc = p;
}
n = strappenda(_BUS_ERROR_DNS, rc);
-
- sd_bus_error_setf(&error, n, "Could not resolve hostname %s, server or network returned error %s", q->request_hostname, rc);
+ sd_bus_error_setf(&error, n, "Could not resolve '%s', server or network returned error %s", name, rc);
}
- r = sd_bus_reply_method_error(q->request, &error);
- break;
+ return sd_bus_reply_method_error(q->request, &error);
}
- case DNS_QUERY_SUCCESS: {
- _cleanup_bus_message_unref_ sd_bus_message *reply = NULL;
- unsigned i, n, added = 0;
+ case DNS_QUERY_NULL:
+ case DNS_QUERY_SENT:
+ case DNS_QUERY_SUCCESS:
+ assert_not_reached("Impossible state");
+ }
+}
- assert(q->packet);
+static void bus_method_resolve_hostname_complete(DnsQuery *q) {
+ _cleanup_bus_message_unref_ sd_bus_message *reply = NULL;
+ unsigned i, n, added = 0;
+ int r;
- r = dns_packet_skip_question(q->packet);
- if (r < 0)
- goto parse_fail;
+ assert(q);
- r = sd_bus_message_new_method_return(q->request, &reply);
- if (r < 0)
- goto finish;
+ if (q->state != DNS_QUERY_SUCCESS) {
+ r = reply_query_state(q);
+ goto finish;
+ }
- r = sd_bus_message_open_container(reply, 'a', "(yayi)");
- if (r < 0)
- goto finish;
+ assert(q->received);
- n = DNS_PACKET_ANCOUNT(q->packet) +
- DNS_PACKET_NSCOUNT(q->packet) +
- DNS_PACKET_ARCOUNT(q->packet);
- for (i = 0; i < n; i++) {
- _cleanup_(dns_resource_record_unrefp) DnsResourceRecord *rr = NULL;
+ r = dns_packet_skip_question(q->received);
+ if (r < 0)
+ goto parse_fail;
- r = dns_packet_read_rr(q->packet, &rr, NULL);
- if (r < 0)
- goto parse_fail;
+ r = sd_bus_message_new_method_return(q->request, &reply);
+ if (r < 0)
+ goto finish;
- if (rr->key.class != DNS_CLASS_IN)
- continue;
+ r = sd_bus_message_open_container(reply, 'a', "(yayi)");
+ if (r < 0)
+ goto finish;
- if (!(q->request_family != AF_INET6 && rr->key.type == DNS_TYPE_A) &&
- !(q->request_family != AF_INET && rr->key.type == DNS_TYPE_AAAA))
- continue;
+ 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;
- if (!dns_name_equal(rr->key.name, q->request_hostname))
- continue;
+ r = dns_packet_read_rr(q->received, &rr, NULL);
+ if (r < 0)
+ goto parse_fail;
- r = sd_bus_message_open_container(reply, 'r', "yayi");
- if (r < 0)
- goto finish;
+ if (rr->key.class != DNS_CLASS_IN)
+ continue;
- if (rr->key.type == DNS_TYPE_A) {
- r = sd_bus_message_append(reply, "y", AF_INET);
- if (r < 0)
- goto finish;
+ 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 = 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;
+ if (!dns_name_equal(rr->key.name, q->request_hostname))
+ continue;
- r = sd_bus_message_append_array(reply, 'y', &rr->aaaa.in6_addr, sizeof(struct in6_addr));
- }
- if (r < 0)
- goto finish;
+ r = sd_bus_message_open_container(reply, 'r', "yayi");
+ if (r < 0)
+ goto finish;
- r = sd_bus_message_append(reply, "i", q->packet->ifindex);
+ 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_close_container(reply);
+ 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)
+ goto finish;
- if (added <= 0) {
- r = sd_bus_reply_method_errorf(q->request, BUS_ERROR_NO_SUCH_RR, "Hostname %s does not have RR of this type", q->request_hostname);
- break;
- }
+ r = sd_bus_message_append(reply, "i", q->received->ifindex);
+ if (r < 0)
+ goto finish;
r = sd_bus_message_close_container(reply);
if (r < 0)
goto finish;
- r = sd_bus_send(q->manager->bus, reply, NULL);
- break;
+ added ++;
}
- parse_fail:
- case DNS_QUERY_INVALID_REPLY:
- r = sd_bus_reply_method_errorf(q->request, BUS_ERROR_INVALID_REPLY, "Received invalid reply");
- break;
-
- case DNS_QUERY_NULL:
- case DNS_QUERY_SENT:
- assert_not_reached("Unexpected query state");
+ 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 = sd_bus_message_close_container(reply);
+ if (r < 0)
+ goto finish;
+
+ r = sd_bus_send(q->manager->bus, reply, NULL);
+ goto finish;
+
+parse_fail:
+ r = sd_bus_reply_method_errorf(q->request, BUS_ERROR_INVALID_REPLY, "Received invalid reply");
+
finish:
if (r < 0)
log_error("Failed to send bus reply: %s", strerror(-r));
@@ -223,120 +243,79 @@ static int bus_method_resolve_hostname(sd_bus *bus, sd_bus_message *message, voi
}
static void bus_method_resolve_address_complete(DnsQuery *q) {
- _cleanup_free_ char *ip = NULL;
+ _cleanup_bus_message_unref_ sd_bus_message *reply = NULL;
+ unsigned i, n, added = 0;
+ _cleanup_free_ char *reverse = NULL;
int r;
assert(q);
- in_addr_to_string(q->request_family, &q->request_address, &ip);
-
- switch(q->state) {
-
- case DNS_QUERY_SKIPPED:
- r = sd_bus_reply_method_errorf(q->request, BUS_ERROR_NO_NAME_SERVERS, "Not appropriate name servers or networks found");
- break;
-
- case DNS_QUERY_TIMEOUT:
- r = sd_bus_reply_method_errorf(q->request, SD_BUS_ERROR_TIMEOUT, "Query timed out");
- break;
-
- case DNS_QUERY_ATTEMPTS_MAX:
- r = sd_bus_reply_method_errorf(q->request, SD_BUS_ERROR_TIMEOUT, "All attempts to contact name servers or networks failed");
- break;
-
- case DNS_QUERY_FAILURE: {
- _cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL;
-
- if (q->rcode == DNS_RCODE_NXDOMAIN)
- sd_bus_error_setf(&error, _BUS_ERROR_DNS "NXDOMAIN", "No hostname known for address %s ", ip);
- else {
- const char *rc, *n;
- char p[DECIMAL_STR_MAX(q->rcode)];
+ if (q->state != DNS_QUERY_SUCCESS) {
+ r = reply_query_state(q);
+ goto finish;
+ }
- rc = dns_rcode_to_string(q->rcode);
- if (!rc) {
- sprintf(p, "%i", q->rcode);
- rc = p;
- }
+ assert(q->received);
- n = strappenda(_BUS_ERROR_DNS, rc);
+ r = dns_name_reverse(q->request_family, &q->request_address, &reverse);
+ if (r < 0)
+ goto finish;
- sd_bus_error_setf(&error, n, "Could not resolve address %s, server or network returned error %s", ip, rc);
- }
+ r = dns_packet_skip_question(q->received);
+ if (r < 0)
+ goto parse_fail;
- r = sd_bus_reply_method_error(q->request, &error);
- break;
- }
+ r = sd_bus_message_new_method_return(q->request, &reply);
+ if (r < 0)
+ goto finish;
- case DNS_QUERY_SUCCESS: {
- _cleanup_bus_message_unref_ sd_bus_message *reply = NULL;
- unsigned i, n, added = 0;
- _cleanup_free_ char *reverse = NULL;
+ r = sd_bus_message_open_container(reply, 'a', "s");
+ if (r < 0)
+ goto finish;
- assert(q->packet);
+ n = DNS_PACKET_ANCOUNT(q->received) +
+ DNS_PACKET_NSCOUNT(q->received) +
+ DNS_PACKET_ARCOUNT(q->received);
- r = dns_name_reverse(q->request_family, &q->request_address, &reverse);
- if (r < 0)
- goto finish;
+ for (i = 0; i < n; i++) {
+ _cleanup_(dns_resource_record_unrefp) DnsResourceRecord *rr = NULL;
- r = dns_packet_skip_question(q->packet);
+ r = dns_packet_read_rr(q->received, &rr, NULL);
if (r < 0)
goto parse_fail;
- r = sd_bus_message_new_method_return(q->request, &reply);
- if (r < 0)
- goto finish;
+ if (rr->key.class != DNS_CLASS_IN)
+ continue;
+ if (rr->key.type != DNS_TYPE_PTR)
+ continue;
+ if (!dns_name_equal(rr->key.name, reverse))
+ continue;
- r = sd_bus_message_open_container(reply, 'a', "s");
+ r = sd_bus_message_append(reply, "s", rr->ptr.name);
if (r < 0)
goto finish;
- n = DNS_PACKET_ANCOUNT(q->packet) +
- DNS_PACKET_NSCOUNT(q->packet) +
- DNS_PACKET_ARCOUNT(q->packet);
- for (i = 0; i < n; i++) {
- _cleanup_(dns_resource_record_unrefp) DnsResourceRecord *rr = NULL;
-
- r = dns_packet_read_rr(q->packet, &rr, NULL);
- 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))
- continue;
-
- r = sd_bus_message_append(reply, "s", rr->ptr.name);
- if (r < 0)
- goto finish;
-
- added ++;
- }
+ added ++;
+ }
- if (added <= 0) {
- r = sd_bus_reply_method_errorf(q->request, BUS_ERROR_NO_SUCH_RR, "Address %s does not have RR of this type", ip);
- break;
- }
+ if (added <= 0) {
+ _cleanup_free_ char *ip = NULL;
- r = sd_bus_message_close_container(reply);
- if (r < 0)
- goto finish;
+ in_addr_to_string(q->request_family, &q->request_address, &ip);
- r = sd_bus_send(q->manager->bus, reply, NULL);
- break;
+ r = sd_bus_reply_method_errorf(q->request, BUS_ERROR_NO_SUCH_RR, "Address '%s' does not have RR of this type", ip);
+ goto finish;
}
- parse_fail:
- case DNS_QUERY_INVALID_REPLY:
- r = sd_bus_reply_method_errorf(q->request, BUS_ERROR_INVALID_REPLY, "Received invalid reply");
- break;
+ r = sd_bus_message_close_container(reply);
+ if (r < 0)
+ goto finish;
- case DNS_QUERY_NULL:
- case DNS_QUERY_SENT:
- assert_not_reached("Unexpected query state");
- }
+ r = sd_bus_send(q->manager->bus, reply, NULL);
+ goto finish;
+
+parse_fail:
+ r = sd_bus_reply_method_errorf(q->request, BUS_ERROR_INVALID_REPLY, "Received invalid reply");
finish:
if (r < 0)
diff --git a/src/resolve/resolved-dns-packet.h b/src/resolve/resolved-dns-packet.h
index 10f8f96915..d4c9c475f5 100644
--- a/src/resolve/resolved-dns-packet.h
+++ b/src/resolve/resolved-dns-packet.h
@@ -71,6 +71,7 @@ static inline uint8_t* DNS_PACKET_DATA(DnsPacket *p) {
#define DNS_PACKET_QR(p) ((be16toh(DNS_PACKET_HEADER(p)->flags) >> 15) & 1)
#define DNS_PACKET_OPCODE(p) ((be16toh(DNS_PACKET_HEADER(p)->flags) >> 11) & 15)
#define DNS_PACKET_RCODE(p) (be16toh(DNS_PACKET_HEADER(p)->flags) & 15)
+#define DNS_PACKET_TC(p) ((be16toh(DNS_PACKET_HEADER(p)->flags) >> 9) & 1)
#define DNS_PACKET_QDCOUNT(p) be16toh(DNS_PACKET_HEADER(p)->qdcount)
#define DNS_PACKET_ANCOUNT(p) be16toh(DNS_PACKET_HEADER(p)->ancount)
#define DNS_PACKET_NSCOUNT(p) be16toh(DNS_PACKET_HEADER(p)->nscount)
diff --git a/src/resolve/resolved-dns-query.c b/src/resolve/resolved-dns-query.c
index dd812150cf..5bd5920254 100644
--- a/src/resolve/resolved-dns-query.c
+++ b/src/resolve/resolved-dns-query.c
@@ -31,7 +31,12 @@ DnsQueryTransaction* dns_query_transaction_free(DnsQueryTransaction *t) {
return NULL;
sd_event_source_unref(t->timeout_event_source);
- dns_packet_unref(t->packet);
+
+ dns_packet_unref(t->sent);
+ dns_packet_unref(t->received);
+
+ sd_event_source_unref(t->tcp_event_source);
+ safe_close(t->tcp_fd);
if (t->query) {
LIST_REMOVE(transactions_by_query, t->query->transactions, t);
@@ -62,6 +67,8 @@ static int dns_query_transaction_new(DnsQuery *q, DnsQueryTransaction **ret, Dns
if (!t)
return -ENOMEM;
+ t->tcp_fd = -1;
+
do
random_bytes(&t->id, sizeof(t->id));
while (t->id == 0 ||
@@ -87,6 +94,14 @@ static int dns_query_transaction_new(DnsQuery *q, DnsQueryTransaction **ret, Dns
return 0;
}
+static void dns_query_transaction_stop(DnsQueryTransaction *t) {
+ assert(t);
+
+ t->timeout_event_source = sd_event_source_unref(t->timeout_event_source);
+ t->tcp_event_source = sd_event_source_unref(t->tcp_event_source);
+ t->tcp_fd = safe_close(t->tcp_fd);
+}
+
static void dns_query_transaction_set_state(DnsQueryTransaction *t, DnsQueryState state) {
assert(t);
@@ -95,24 +110,179 @@ static void dns_query_transaction_set_state(DnsQueryTransaction *t, DnsQueryStat
t->state = state;
- if (state != DNS_QUERY_SENT)
- t->timeout_event_source = sd_event_source_unref(t->timeout_event_source);
+ if (state != DNS_QUERY_SENT) {
+ dns_query_transaction_stop(t);
+ dns_query_finish(t->query);
+ }
+}
+
+static int on_tcp_ready(sd_event_source *s, int fd, uint32_t revents, void *userdata) {
+ DnsQueryTransaction *t = userdata;
+ int r;
+
+ assert(t);
+
+ if (revents & EPOLLOUT) {
+ struct iovec iov[2];
+ be16_t sz;
+ ssize_t ss;
+
+ sz = htobe16(t->sent->size);
+
+ iov[0].iov_base = &sz;
+ iov[0].iov_len = sizeof(sz);
+ iov[1].iov_base = DNS_PACKET_DATA(t->sent);
+ iov[1].iov_len = t->sent->size;
+
+ IOVEC_INCREMENT(iov, 2, t->tcp_written);
+
+ ss = writev(fd, iov, 2);
+ if (ss < 0) {
+ if (errno != EINTR && errno != EAGAIN) {
+ dns_query_transaction_set_state(t, DNS_QUERY_RESOURCES);
+ return -errno;
+ }
+ } else
+ t->tcp_written += ss;
+
+ /* Are we done? If so, disable the event source for EPOLLOUT */
+ if (t->tcp_written >= sizeof(sz) + t->sent->size) {
+ r = sd_event_source_set_io_events(s, EPOLLIN);
+ if (r < 0) {
+ dns_query_transaction_set_state(t, DNS_QUERY_RESOURCES);
+ return r;
+ }
+ }
+ }
+
+ if (revents & (EPOLLIN|EPOLLHUP|EPOLLRDHUP)) {
+
+ if (t->tcp_read < sizeof(t->tcp_read_size)) {
+ ssize_t ss;
+
+ ss = read(fd, (uint8_t*) &t->tcp_read_size + t->tcp_read, sizeof(t->tcp_read_size) - t->tcp_read);
+ if (ss < 0) {
+ if (errno != EINTR && errno != EAGAIN) {
+ dns_query_transaction_set_state(t, DNS_QUERY_RESOURCES);
+ return -errno;
+ }
+ } else if (ss == 0) {
+ dns_query_transaction_set_state(t, DNS_QUERY_RESOURCES);
+ return -EIO;
+ } else
+ t->tcp_read += ss;
+ }
+
+ if (t->tcp_read >= sizeof(t->tcp_read_size)) {
+
+ if (be16toh(t->tcp_read_size) < DNS_PACKET_HEADER_SIZE) {
+ dns_query_transaction_set_state(t, DNS_QUERY_INVALID_REPLY);
+ return -EBADMSG;
+ }
+
+ if (t->tcp_read < sizeof(t->tcp_read_size) + be16toh(t->tcp_read_size)) {
+ ssize_t ss;
+
+ if (!t->received) {
+ r = dns_packet_new(&t->received, be16toh(t->tcp_read_size));
+ if (r < 0) {
+ dns_query_transaction_set_state(t, DNS_QUERY_RESOURCES);
+ return r;
+ }
+ }
+
+ ss = read(fd,
+ (uint8_t*) DNS_PACKET_DATA(t->received) + t->tcp_read - sizeof(t->tcp_read_size),
+ sizeof(t->tcp_read_size) + be16toh(t->tcp_read_size) - t->tcp_read);
+ if (ss < 0) {
+ if (errno != EINTR && errno != EAGAIN) {
+ dns_query_transaction_set_state(t, DNS_QUERY_RESOURCES);
+ return -errno;
+ }
+ } else if (ss == 0) {
+ dns_query_transaction_set_state(t, DNS_QUERY_RESOURCES);
+ return -EIO;
+ } else
+ t->tcp_read += ss;
+ }
+
+ if (t->tcp_read >= sizeof(t->tcp_read_size) + be16toh(t->tcp_read_size)) {
+ t->received->size = be16toh(t->tcp_read_size);
+ dns_query_transaction_reply(t, t->received);
+ return 0;
+ }
+ }
+ }
+
+ return 0;
+}
+
+static int dns_query_transaction_start_tcp(DnsQueryTransaction *t) {
+ int r;
+
+ assert(t);
+
+ if (t->tcp_fd >= 0)
+ return 0;
+
+ t->tcp_written = 0;
+ t->tcp_read = 0;
+ t->received = dns_packet_unref(t->received);
+
+ t->tcp_fd = dns_scope_tcp_socket(t->scope);
+ if (t->tcp_fd < 0)
+ return t->tcp_fd;
+
+ r = sd_event_add_io(t->query->manager->event, &t->tcp_event_source, t->tcp_fd, EPOLLIN|EPOLLOUT, on_tcp_ready, t);
+ if (r < 0) {
+ t->tcp_fd = safe_close(t->tcp_fd);
+ return r;
+ }
- dns_query_finish(t->query);
+ return 0;
}
-int dns_query_transaction_reply(DnsQueryTransaction *t, DnsPacket *p) {
+void dns_query_transaction_reply(DnsQueryTransaction *t, DnsPacket *p) {
+ int r;
+
assert(t);
assert(p);
- t->packet = dns_packet_ref(p);
+ if (t->state != DNS_QUERY_SENT)
+ return;
+
+ if (t->received != p) {
+ dns_packet_unref(t->received);
+ t->received = dns_packet_ref(p);
+ }
+
+ if (t->tcp_fd >= 0) {
+ if (DNS_PACKET_TC(p)) {
+ /* Truncated via TCP? Somebody must be fucking with us */
+ dns_query_transaction_set_state(t, DNS_QUERY_INVALID_REPLY);
+ return;
+ }
+
+ if (DNS_PACKET_ID(p) != t->id) {
+ /* Not the reply to our query? Somebody must be fucking with us */
+ dns_query_transaction_set_state(t, DNS_QUERY_INVALID_REPLY);
+ return;
+ }
+ }
+
+ 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 < 0) {
+ dns_query_transaction_set_state(t, DNS_QUERY_RESOURCES);
+ return;
+ }
+ }
if (DNS_PACKET_RCODE(p) == DNS_RCODE_SUCCESS)
dns_query_transaction_set_state(t, DNS_QUERY_SUCCESS);
else
dns_query_transaction_set_state(t, DNS_QUERY_FAILURE);
-
- return 0;
}
static int on_transaction_timeout(sd_event_source *s, usec_t usec, void *userdata) {
@@ -127,26 +297,20 @@ static int on_transaction_timeout(sd_event_source *s, usec_t usec, void *userdat
r = dns_query_transaction_start(t);
if (r < 0)
- dns_query_transaction_set_state(t, DNS_QUERY_FAILURE);
+ dns_query_transaction_set_state(t, DNS_QUERY_RESOURCES);
return 0;
}
-int dns_query_transaction_start(DnsQueryTransaction *t) {
+static int dns_query_make_packet(DnsQueryTransaction *t) {
_cleanup_(dns_packet_unrefp) DnsPacket *p = NULL;
unsigned n;
int r;
assert(t);
- t->timeout_event_source = sd_event_source_unref(t->timeout_event_source);
-
- if (t->n_attempts >= ATTEMPTS_MAX) {
- dns_query_transaction_set_state(t, DNS_QUERY_ATTEMPTS_MAX);
+ if (t->sent)
return 0;
- }
-
- t->n_attempts++;
r = dns_packet_new_query(&p, 0);
if (r < 0)
@@ -161,7 +325,38 @@ int dns_query_transaction_start(DnsQueryTransaction *t) {
DNS_PACKET_HEADER(p)->qdcount = htobe16(t->query->n_keys);
DNS_PACKET_HEADER(p)->id = t->id;
- r = dns_scope_send(t->scope, p);
+ t->sent = p;
+ p = NULL;
+
+ return 0;
+}
+
+int dns_query_transaction_start(DnsQueryTransaction *t) {
+ int r;
+
+ assert(t);
+
+ dns_query_transaction_stop(t);
+
+ if (t->n_attempts >= ATTEMPTS_MAX) {
+ 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;
+
+ /* 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)
+ r = dns_query_transaction_start_tcp(t);
+
+ if (r == -ESRCH) {
+ dns_query_transaction_set_state(t, DNS_QUERY_NO_SERVERS);
+ return 0;
+ }
if (r < 0) {
/* Couldn't send? Try immediately again, with a new server */
dns_scope_next_dns_server(t->scope);
@@ -169,18 +364,12 @@ int dns_query_transaction_start(DnsQueryTransaction *t) {
return dns_query_transaction_start(t);
}
- if (r > 0) {
- int q;
-
- q = sd_event_add_time(t->query->manager->event, &t->timeout_event_source, CLOCK_MONOTONIC, now(CLOCK_MONOTONIC) + TRANSACTION_TIMEOUT_USEC, 0, on_transaction_timeout, t);
- if (q < 0)
- return q;
-
- dns_query_transaction_set_state(t, DNS_QUERY_SENT);
- } else
- dns_query_transaction_set_state(t, DNS_QUERY_SKIPPED);
+ r = sd_event_add_time(t->query->manager->event, &t->timeout_event_source, CLOCK_MONOTONIC, now(CLOCK_MONOTONIC) + TRANSACTION_TIMEOUT_USEC, 0, on_transaction_timeout, t);
+ if (r < 0)
+ return r;
- return r;
+ dns_query_transaction_set_state(t, DNS_QUERY_SENT);
+ return 1;
}
DnsQuery *dns_query_free(DnsQuery *q) {
@@ -190,7 +379,7 @@ DnsQuery *dns_query_free(DnsQuery *q) {
return NULL;
sd_bus_message_unref(q->request);
- dns_packet_unref(q->packet);
+ dns_packet_unref(q->received);
sd_event_source_unref(q->timeout_event_source);
while (q->transactions)
@@ -367,8 +556,8 @@ fail:
void dns_query_finish(DnsQuery *q) {
DnsQueryTransaction *t;
- DnsQueryState state = DNS_QUERY_SKIPPED;
- uint16_t rcode = 0;
+ DnsQueryState state = DNS_QUERY_NO_SERVERS;
+ DnsPacket *received = NULL;
assert(q);
@@ -381,25 +570,28 @@ void dns_query_finish(DnsQuery *q) {
if (t->state == DNS_QUERY_SENT || t->state == DNS_QUERY_NULL)
return;
- /* One of the transactions is sucecssful, let's use it */
+ /* One of the transactions is successful, let's use it */
if (t->state == DNS_QUERY_SUCCESS) {
- q->packet = dns_packet_ref(t->packet);
+ q->received = dns_packet_ref(t->received);
dns_query_set_state(q, DNS_QUERY_SUCCESS);
return;
}
+ /* One of the transactions has failed, let's see
+ * whether we find anything better, but if not, return
+ * its response packet */
if (t->state == DNS_QUERY_FAILURE) {
+ received = t->received;
state = DNS_QUERY_FAILURE;
+ continue;
+ }
- if (rcode == 0 && t->packet)
- rcode = DNS_PACKET_RCODE(t->packet);
-
- } else if (state == DNS_QUERY_SKIPPED && t->state != DNS_QUERY_SKIPPED)
+ if (state == DNS_QUERY_NO_SERVERS && t->state != DNS_QUERY_NO_SERVERS)
state = t->state;
}
if (state == DNS_QUERY_FAILURE)
- q->rcode = rcode;
+ q->received = dns_packet_ref(received);
dns_query_set_state(q, state);
}
diff --git a/src/resolve/resolved-dns-query.h b/src/resolve/resolved-dns-query.h
index a07f174706..d5bc08dc30 100644
--- a/src/resolve/resolved-dns-query.h
+++ b/src/resolve/resolved-dns-query.h
@@ -39,10 +39,11 @@ typedef enum DnsQueryState {
DNS_QUERY_SENT,
DNS_QUERY_FAILURE,
DNS_QUERY_SUCCESS,
- DNS_QUERY_SKIPPED,
+ DNS_QUERY_NO_SERVERS,
DNS_QUERY_TIMEOUT,
DNS_QUERY_ATTEMPTS_MAX,
DNS_QUERY_INVALID_REPLY,
+ DNS_QUERY_RESOURCES,
} DnsQueryState;
struct DnsQueryTransaction {
@@ -55,7 +56,13 @@ struct DnsQueryTransaction {
sd_event_source *timeout_event_source;
unsigned n_attempts;
- DnsPacket *packet;
+ DnsPacket *sent, *received;
+
+ /* TCP connection logic */
+ int tcp_fd;
+ sd_event_source *tcp_event_source;
+ size_t tcp_written, tcp_read;
+ be16_t tcp_read_size;
LIST_FIELDS(DnsQueryTransaction, transactions_by_query);
LIST_FIELDS(DnsQueryTransaction, transactions_by_scope);
@@ -71,8 +78,7 @@ struct DnsQuery {
sd_event_source *timeout_event_source;
- uint16_t rcode;
- DnsPacket *packet;
+ DnsPacket *received;
sd_bus_message *request;
unsigned char request_family;
@@ -92,6 +98,6 @@ void dns_query_finish(DnsQuery *q);
DnsQueryTransaction* dns_query_transaction_free(DnsQueryTransaction *t);
int dns_query_transaction_start(DnsQueryTransaction *t);
-int dns_query_transaction_reply(DnsQueryTransaction *t, DnsPacket *p);
+void dns_query_transaction_reply(DnsQueryTransaction *t, DnsPacket *p);
DEFINE_TRIVIAL_CLEANUP_FUNC(DnsQuery*, dns_query_free);
diff --git a/src/resolve/resolved-dns-scope.c b/src/resolve/resolved-dns-scope.c
index 4e0a742768..0a70cb1f0f 100644
--- a/src/resolve/resolved-dns-scope.c
+++ b/src/resolve/resolved-dns-scope.c
@@ -19,7 +19,10 @@
along with systemd; If not, see <http://www.gnu.org/licenses/>.
***/
+#include <netinet/tcp.h>
+
#include "strv.h"
+#include "socket-util.h"
#include "resolved-dns-domain.h"
#include "resolved-dns-scope.h"
@@ -92,10 +95,14 @@ int dns_scope_send(DnsScope *s, DnsPacket *p) {
srv = dns_scope_get_server(s);
if (!srv)
- return 0;
+ return -ESRCH;
+
+ if (s->link) {
+ if (p->size > s->link->mtu)
+ return -EMSGSIZE;
- if (s->link)
ifindex = s->link->ifindex;
+ }
if (srv->family == AF_INET)
r = manager_dns_ipv4_send(s->manager, srv, ifindex, p);
@@ -110,6 +117,52 @@ int dns_scope_send(DnsScope *s, DnsPacket *p) {
return 1;
}
+int dns_scope_tcp_socket(DnsScope *s) {
+ _cleanup_close_ int fd = -1;
+ union sockaddr_union sa = {};
+ socklen_t salen;
+ int one, ifindex, ret;
+ DnsServer *srv;
+ int r;
+
+ assert(s);
+
+ srv = dns_scope_get_server(s);
+ if (!srv)
+ return -ESRCH;
+
+ if (s->link)
+ ifindex = s->link->ifindex;
+
+ sa.sa.sa_family = srv->family;
+ if (srv->family == AF_INET) {
+ sa.in.sin_port = htobe16(53);
+ sa.in.sin_addr = srv->address.in;
+ salen = sizeof(sa.in);
+ } else if (srv->family == AF_INET6) {
+ sa.in6.sin6_port = htobe16(53);
+ sa.in6.sin6_addr = srv->address.in6;
+ sa.in6.sin6_scope_id = ifindex;
+ salen = sizeof(sa.in6);
+ } else
+ return -EAFNOSUPPORT;
+
+ fd = socket(srv->family, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0);
+ if (fd < 0)
+ return -errno;
+
+ one = 1;
+ setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &one, sizeof(one));
+
+ r = connect(fd, &sa.sa, salen);
+ if (r < 0 && errno != EINPROGRESS)
+ return -errno;
+
+ ret = fd;
+ fd = -1;
+ return ret;
+}
+
DnsScopeMatch dns_scope_test(DnsScope *s, const char *domain) {
char **i;
diff --git a/src/resolve/resolved-dns-scope.h b/src/resolve/resolved-dns-scope.h
index 50f1106bf1..97544f9e48 100644
--- a/src/resolve/resolved-dns-scope.h
+++ b/src/resolve/resolved-dns-scope.h
@@ -63,6 +63,8 @@ int dns_scope_new(Manager *m, DnsScope **ret, DnsScopeType t);
DnsScope* dns_scope_free(DnsScope *s);
int dns_scope_send(DnsScope *s, DnsPacket *p);
+int dns_scope_tcp_socket(DnsScope *s);
+
DnsScopeMatch dns_scope_test(DnsScope *s, const char *domain);
DnsServer *dns_scope_get_server(DnsScope *s);
diff --git a/src/resolve/resolved-manager.c b/src/resolve/resolved-manager.c
index 09b758f3f4..3d2979dbbe 100644
--- a/src/resolve/resolved-manager.c
+++ b/src/resolve/resolved-manager.c
@@ -577,7 +577,7 @@ int manager_dns_ipv4_recv(Manager *m, DnsPacket **ret) {
l = recvmsg(fd, &mh, 0);
if (l < 0) {
- if (errno == EAGAIN)
+ if (errno == EAGAIN || errno == EINTR)
return 0;
return -errno;
@@ -626,7 +626,7 @@ int manager_dns_ipv6_recv(Manager *m, DnsPacket **ret) {
l = recvmsg(fd, &mh, 0);
if (l < 0) {
- if (errno == EAGAIN)
+ if (errno == EAGAIN || errno == EINTR)
return 0;
return -errno;
@@ -657,7 +657,8 @@ static int on_dns_ipv4_packet(sd_event_source *s, int fd, uint32_t revents, void
if (!t)
return 0;
- return dns_query_transaction_reply(t, p);
+ dns_query_transaction_reply(t, p);
+ return 0;
}
static int on_dns_ipv6_packet(sd_event_source *s, int fd, uint32_t revents, void *userdata) {
@@ -674,7 +675,8 @@ static int on_dns_ipv6_packet(sd_event_source *s, int fd, uint32_t revents, void
if (!t)
return 0;
- return dns_query_transaction_reply(t, p);
+ dns_query_transaction_reply(t, p);
+ return 0;
}
int manager_dns_ipv4_fd(Manager *m) {