qemu/io/dns-resolver.c

280 lines
7.9 KiB
C

/*
* QEMU DNS resolver
*
* Copyright (c) 2016 Red Hat, Inc.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, see <http://www.gnu.org/licenses/>.
*
*/
#include "qemu/osdep.h"
#include "io/dns-resolver.h"
#include "qapi/clone-visitor.h"
#include "qapi/qapi-visit-sockets.h"
#include "qemu/sockets.h"
#include "qapi/error.h"
#include "qemu/cutils.h"
#ifndef AI_NUMERICSERV
# define AI_NUMERICSERV 0
#endif
static QIODNSResolver *instance;
static GOnce instance_init = G_ONCE_INIT;
static gpointer qio_dns_resolve_init_instance(gpointer unused G_GNUC_UNUSED)
{
instance = QIO_DNS_RESOLVER(object_new(TYPE_QIO_DNS_RESOLVER));
return NULL;
}
QIODNSResolver *qio_dns_resolver_get_instance(void)
{
g_once(&instance_init, qio_dns_resolve_init_instance, NULL);
return instance;
}
static int qio_dns_resolver_lookup_sync_inet(QIODNSResolver *resolver,
SocketAddress *addr,
size_t *naddrs,
SocketAddress ***addrs,
Error **errp)
{
struct addrinfo ai, *res, *e;
InetSocketAddress *iaddr = &addr->u.inet;
char port[33];
char uaddr[INET6_ADDRSTRLEN + 1];
char uport[33];
int rc;
Error *err = NULL;
size_t i;
*naddrs = 0;
*addrs = NULL;
memset(&ai, 0, sizeof(ai));
ai.ai_flags = AI_PASSIVE;
if (iaddr->has_numeric && iaddr->numeric) {
ai.ai_flags |= AI_NUMERICHOST | AI_NUMERICSERV;
}
ai.ai_family = inet_ai_family_from_address(iaddr, &err);
ai.ai_socktype = SOCK_STREAM;
if (err) {
error_propagate(errp, err);
return -1;
}
if (iaddr->host == NULL) {
error_setg(errp, "host not specified");
return -1;
}
if (iaddr->port != NULL) {
pstrcpy(port, sizeof(port), iaddr->port);
} else {
port[0] = '\0';
}
rc = getaddrinfo(strlen(iaddr->host) ? iaddr->host : NULL,
strlen(port) ? port : NULL, &ai, &res);
if (rc != 0) {
error_setg(errp, "address resolution failed for %s:%s: %s",
iaddr->host, port, gai_strerror(rc));
return -1;
}
for (e = res; e != NULL; e = e->ai_next) {
(*naddrs)++;
}
*addrs = g_new0(SocketAddress *, *naddrs);
/* create socket + bind */
for (i = 0, e = res; e != NULL; i++, e = e->ai_next) {
SocketAddress *newaddr = g_new0(SocketAddress, 1);
newaddr->type = SOCKET_ADDRESS_TYPE_INET;
getnameinfo((struct sockaddr *)e->ai_addr, e->ai_addrlen,
uaddr, INET6_ADDRSTRLEN, uport, 32,
NI_NUMERICHOST | NI_NUMERICSERV);
newaddr->u.inet = (InetSocketAddress){
.host = g_strdup(uaddr),
.port = g_strdup(uport),
.has_numeric = true,
.numeric = true,
.has_to = iaddr->has_to,
.to = iaddr->to,
.has_ipv4 = iaddr->has_ipv4,
.ipv4 = iaddr->ipv4,
.has_ipv6 = iaddr->has_ipv6,
.ipv6 = iaddr->ipv6,
};
(*addrs)[i] = newaddr;
}
freeaddrinfo(res);
return 0;
}
static int qio_dns_resolver_lookup_sync_nop(QIODNSResolver *resolver,
SocketAddress *addr,
size_t *naddrs,
SocketAddress ***addrs,
Error **errp)
{
*naddrs = 1;
*addrs = g_new0(SocketAddress *, 1);
(*addrs)[0] = QAPI_CLONE(SocketAddress, addr);
return 0;
}
int qio_dns_resolver_lookup_sync(QIODNSResolver *resolver,
SocketAddress *addr,
size_t *naddrs,
SocketAddress ***addrs,
Error **errp)
{
switch (addr->type) {
case SOCKET_ADDRESS_TYPE_INET:
return qio_dns_resolver_lookup_sync_inet(resolver,
addr,
naddrs,
addrs,
errp);
case SOCKET_ADDRESS_TYPE_UNIX:
case SOCKET_ADDRESS_TYPE_VSOCK:
case SOCKET_ADDRESS_TYPE_FD:
return qio_dns_resolver_lookup_sync_nop(resolver,
addr,
naddrs,
addrs,
errp);
default:
abort();
}
}
struct QIODNSResolverLookupData {
SocketAddress *addr;
SocketAddress **addrs;
size_t naddrs;
};
static void qio_dns_resolver_lookup_data_free(gpointer opaque)
{
struct QIODNSResolverLookupData *data = opaque;
size_t i;
qapi_free_SocketAddress(data->addr);
for (i = 0; i < data->naddrs; i++) {
qapi_free_SocketAddress(data->addrs[i]);
}
g_free(data->addrs);
g_free(data);
}
static void qio_dns_resolver_lookup_worker(QIOTask *task,
gpointer opaque)
{
QIODNSResolver *resolver = QIO_DNS_RESOLVER(qio_task_get_source(task));
struct QIODNSResolverLookupData *data = opaque;
Error *err = NULL;
qio_dns_resolver_lookup_sync(resolver,
data->addr,
&data->naddrs,
&data->addrs,
&err);
if (err) {
qio_task_set_error(task, err);
} else {
qio_task_set_result_pointer(task, opaque, NULL);
}
object_unref(OBJECT(resolver));
}
void qio_dns_resolver_lookup_async(QIODNSResolver *resolver,
SocketAddress *addr,
QIOTaskFunc func,
gpointer opaque,
GDestroyNotify notify)
{
QIOTask *task;
struct QIODNSResolverLookupData *data =
g_new0(struct QIODNSResolverLookupData, 1);
data->addr = QAPI_CLONE(SocketAddress, addr);
task = qio_task_new(OBJECT(resolver), func, opaque, notify);
qio_task_run_in_thread(task,
qio_dns_resolver_lookup_worker,
data,
qio_dns_resolver_lookup_data_free,
NULL);
}
void qio_dns_resolver_lookup_result(QIODNSResolver *resolver,
QIOTask *task,
size_t *naddrs,
SocketAddress ***addrs)
{
struct QIODNSResolverLookupData *data =
qio_task_get_result_pointer(task);
size_t i;
*naddrs = 0;
*addrs = NULL;
if (!data) {
return;
}
*naddrs = data->naddrs;
*addrs = g_new0(SocketAddress *, data->naddrs);
for (i = 0; i < data->naddrs; i++) {
(*addrs)[i] = QAPI_CLONE(SocketAddress, data->addrs[i]);
}
}
static const TypeInfo qio_dns_resolver_info = {
.parent = TYPE_OBJECT,
.name = TYPE_QIO_DNS_RESOLVER,
.instance_size = sizeof(QIODNSResolver),
.class_size = sizeof(QIODNSResolverClass),
};
static void qio_dns_resolver_register_types(void)
{
type_register_static(&qio_dns_resolver_info);
}
type_init(qio_dns_resolver_register_types);