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//
// Copyright 2018 Staysail Systems, Inc. <info@staysail.tech>
// Copyright 2018 Capitar IT Group BV <info@capitar.com>
//
// This software is supplied under the terms of the MIT License, a
// copy of which should be located in the distribution where this
// file was obtained (LICENSE.txt). A copy of the license may also be
// found online at https://opensource.org/licenses/MIT.
//
#include "core/nng_impl.h"
#ifdef NNG_PLATFORM_WINDOWS
// Modern Windows has an asynchronous resolver, but there are problems
// with it, where looking up names in DNS can poison results for other
// uses, because the asynchronous resolver *only* considers DNS -- ignoring
// host file, WINS, or other naming services. As a result, we just build
// our own limited asynchronous using a taskq.
// We use a single resolver taskq - but we allocate a few threads
// for it to ensure that names can be looked up concurrently. This isn't
// as elegant or scaleable as a true asynchronous resolver would be, but
// it has the advantage of being fairly portable, and concurrent enough for
// the vast, vast majority of use cases. The total thread count can be
// changed with this define.
#ifndef NNG_WIN_RESOLV_CONCURRENCY
#define NNG_WIN_RESOLV_CONCURRENCY 4
#endif
static nni_taskq *nni_win_resolv_tq = NULL;
static nni_mtx nni_win_resolv_mtx;
typedef struct nni_win_resolv_item nni_win_resolv_item;
struct nni_win_resolv_item {
int family;
int passive;
const char *name;
const char *serv;
int proto;
nni_aio * aio;
nni_task task;
};
static void
nni_win_resolv_finish(nni_win_resolv_item *item, int rv)
{
nni_aio *aio = item->aio;
nni_aio_set_prov_data(aio, NULL);
nni_aio_finish(aio, rv, 0);
NNI_FREE_STRUCT(item);
}
static void
nni_win_resolv_cancel(nni_aio *aio, int rv)
{
nni_win_resolv_item *item;
nni_mtx_lock(&nni_win_resolv_mtx);
if ((item = nni_aio_get_prov_data(aio)) == NULL) {
nni_mtx_unlock(&nni_win_resolv_mtx);
return;
}
nni_aio_set_prov_data(aio, NULL);
nni_mtx_unlock(&nni_win_resolv_mtx);
nni_task_cancel(&item->task);
NNI_FREE_STRUCT(item);
nni_aio_finish_error(aio, rv);
}
static int
nni_win_gai_errno(int rv)
{
switch (rv) {
case 0:
return (0);
case WSA_NOT_ENOUGH_MEMORY:
return (NNG_ENOMEM);
case WSAHOST_NOT_FOUND:
case WSATYPE_NOT_FOUND:
case WSANO_DATA:
return (NNG_EADDRINVAL);
case WSAEINVAL:
return (NNG_EINVAL);
case WSAESOCKTNOSUPPORT:
case WSAEAFNOSUPPORT:
return (NNG_ENOTSUP);
default:
return (NNG_ESYSERR + rv);
}
}
static void
nni_win_resolv_task(void *arg)
{
nni_win_resolv_item *item = arg;
nni_aio * aio = item->aio;
struct addrinfo hints;
struct addrinfo * results;
struct addrinfo * probe;
int rv;
results = NULL;
// We treat these all as IP addresses. The service and the
// host part are split.
memset(&hints, 0, sizeof(hints));
if (item->passive) {
hints.ai_flags |= AI_PASSIVE;
}
hints.ai_flags |= AI_ADDRCONFIG;
hints.ai_protocol = item->proto;
hints.ai_family = item->family;
if (item->family == AF_INET6) {
hints.ai_flags |= AI_V4MAPPED;
}
rv = getaddrinfo(item->name, item->serv, &hints, &results);
if (rv != 0) {
rv = nni_win_gai_errno(rv);
goto done;
}
// We only take the first matching address. Presumably
// DNS load balancing is done by the resolver/server.
rv = NNG_EADDRINVAL;
for (probe = results; probe != NULL; probe = probe->ai_next) {
if ((probe->ai_addr->sa_family == AF_INET) ||
(probe->ai_addr->sa_family == AF_INET6)) {
break;
}
}
if (probe != NULL) {
struct sockaddr_in * sin;
struct sockaddr_in6 *sin6;
nni_sockaddr * sa = nni_aio_get_input(aio, 0);
switch (probe->ai_addr->sa_family) {
case AF_INET:
rv = 0;
sin = (void *) probe->ai_addr;
sa->s_in.sa_family = NNG_AF_INET;
sa->s_in.sa_port = sin->sin_port;
sa->s_in.sa_addr = sin->sin_addr.s_addr;
break;
case AF_INET6:
rv = 0;
sin6 = (void *) probe->ai_addr;
sa->s_in6.sa_family = NNG_AF_INET6;
sa->s_in6.sa_port = sin6->sin6_port;
memcpy(sa->s_in6.sa_addr, sin6->sin6_addr.s6_addr, 16);
break;
}
}
done:
if (results != NULL) {
freeaddrinfo(results);
}
nni_mtx_lock(&nni_win_resolv_mtx);
nni_win_resolv_finish(item, rv);
nni_mtx_unlock(&nni_win_resolv_mtx);
}
static void
nni_win_resolv_ip(const char *host, const char *serv, int passive, int family,
int proto, nni_aio *aio)
{
nni_win_resolv_item *item;
int rv;
int fam;
switch (family) {
case NNG_AF_INET:
fam = AF_INET;
break;
case NNG_AF_INET6:
fam = AF_INET6;
break;
case NNG_AF_UNSPEC:
fam = AF_UNSPEC;
break;
default:
nni_aio_finish_error(aio, NNG_ENOTSUP);
return;
}
if ((item = NNI_ALLOC_STRUCT(item)) == NULL) {
nni_aio_finish_error(aio, NNG_ENOMEM);
return;
}
nni_task_init(
nni_win_resolv_tq, &item->task, nni_win_resolv_task, item);
item->passive = passive;
item->name = host;
item->serv = serv;
item->proto = proto;
item->aio = aio;
item->family = fam;
nni_mtx_lock(&nni_win_resolv_mtx);
// If we were stopped, we're done...
if ((rv = nni_aio_start(aio, nni_win_resolv_cancel, item)) != 0) {
nni_mtx_unlock(&nni_win_resolv_mtx);
NNI_FREE_STRUCT(item);
return;
}
nni_task_dispatch(&item->task);
nni_mtx_unlock(&nni_win_resolv_mtx);
}
void
nni_plat_tcp_resolv(
const char *host, const char *serv, int family, int passive, nni_aio *aio)
{
nni_win_resolv_ip(host, serv, passive, family, IPPROTO_TCP, aio);
}
void
nni_plat_udp_resolv(
const char *host, const char *serv, int family, int passive, nni_aio *aio)
{
nni_win_resolv_ip(host, serv, passive, family, IPPROTO_UDP, aio);
}
int
nni_win_resolv_sysinit(void)
{
int rv;
nni_mtx_init(&nni_win_resolv_mtx);
if ((rv = nni_taskq_init(&nni_win_resolv_tq, 4)) != 0) {
nni_mtx_fini(&nni_win_resolv_mtx);
return (rv);
}
return (0);
}
void
nni_win_resolv_sysfini(void)
{
if (nni_win_resolv_tq != NULL) {
nni_taskq_fini(nni_win_resolv_tq);
nni_win_resolv_tq = NULL;
}
nni_mtx_fini(&nni_win_resolv_mtx);
}
#endif // NNG_PLATFORM_WINDOWS
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