diff options
Diffstat (limited to 'src/core/ext/resolver/dns')
8 files changed, 1265 insertions, 1 deletions
diff --git a/src/core/ext/resolver/dns/c_ares/dns_resolver_ares.c b/src/core/ext/resolver/dns/c_ares/dns_resolver_ares.c new file mode 100644 index 0000000000..01ed011439 --- /dev/null +++ b/src/core/ext/resolver/dns/c_ares/dns_resolver_ares.c @@ -0,0 +1,401 @@ +/* + * + * Copyright 2015, Google Inc. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are + * met: + * + * * Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * * Redistributions in binary form must reproduce the above + * copyright notice, this list of conditions and the following disclaimer + * in the documentation and/or other materials provided with the + * distribution. + * * Neither the name of Google Inc. nor the names of its + * contributors may be used to endorse or promote products derived from + * this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + * + */ + +#include <grpc/support/port_platform.h> +#if GRPC_ARES == 1 + +#include <string.h> + +#include <grpc/support/alloc.h> +#include <grpc/support/host_port.h> +#include <grpc/support/string_util.h> + +#include "src/core/ext/client_channel/http_connect_handshaker.h" +#include "src/core/ext/client_channel/lb_policy_registry.h" +#include "src/core/ext/client_channel/resolver_registry.h" +#include "src/core/ext/resolver/dns/c_ares/grpc_ares_wrapper.h" +#include "src/core/lib/channel/channel_args.h" +#include "src/core/lib/iomgr/combiner.h" +#include "src/core/lib/iomgr/resolve_address.h" +#include "src/core/lib/iomgr/timer.h" +#include "src/core/lib/support/backoff.h" +#include "src/core/lib/support/env.h" +#include "src/core/lib/support/string.h" + +#define BACKOFF_MULTIPLIER 1.6 +#define BACKOFF_JITTER 0.2 +#define BACKOFF_MIN_SECONDS 1 +#define BACKOFF_MAX_SECONDS 120 + +typedef struct { + /** base class: must be first */ + grpc_resolver base; + /** name to resolve (usually the same as target_name) */ + char *name_to_resolve; + /** default port to use */ + char *default_port; + /** channel args. */ + grpc_channel_args *channel_args; + + /** Closures used by the combiner */ + grpc_closure dns_ares_shutdown_locked; + grpc_closure dns_ares_channel_saw_error_locked; + grpc_closure dns_ares_on_retry_timer_locked; + grpc_closure dns_ares_on_resolved_locked; + + /** Combiner guarding the rest of the state */ + grpc_combiner *combiner; + /** are we currently resolving? */ + bool resolving; + /** which version of the result have we published? */ + int published_version; + /** which version of the result is current? */ + int resolved_version; + /** pending next completion, or NULL */ + grpc_closure *next_completion; + /** target result address for next completion */ + grpc_channel_args **target_result; + /** current (fully resolved) result */ + grpc_channel_args *resolved_result; + /** retry timer */ + bool have_retry_timer; + grpc_timer retry_timer; + /** retry backoff state */ + gpr_backoff backoff_state; + + /** currently resolving addresses */ + grpc_resolved_addresses *addresses; +} ares_dns_resolver; + +static void dns_ares_destroy(grpc_exec_ctx *exec_ctx, grpc_resolver *r); + +static void dns_ares_start_resolving_locked(grpc_exec_ctx *exec_ctx, + ares_dns_resolver *r); +static void dns_ares_maybe_finish_next_locked(grpc_exec_ctx *exec_ctx, + ares_dns_resolver *r); + +static void dns_ares_shutdown(grpc_exec_ctx *exec_ctx, grpc_resolver *r); +static void dns_ares_channel_saw_error(grpc_exec_ctx *exec_ctx, + grpc_resolver *r); +static void dns_ares_next(grpc_exec_ctx *exec_ctx, grpc_resolver *r, + grpc_channel_args **target_result, + grpc_closure *on_complete); + +static const grpc_resolver_vtable dns_ares_resolver_vtable = { + dns_ares_destroy, dns_ares_shutdown, dns_ares_channel_saw_error, + dns_ares_next}; + +static void dns_ares_shutdown_locked(grpc_exec_ctx *exec_ctx, void *arg, + grpc_error *error) { + ares_dns_resolver *r = arg; + GPR_ASSERT(error == GRPC_ERROR_NONE); + if (r->have_retry_timer) { + grpc_timer_cancel(exec_ctx, &r->retry_timer); + } + if (r->next_completion != NULL) { + *r->target_result = NULL; + grpc_exec_ctx_sched(exec_ctx, r->next_completion, + GRPC_ERROR_CREATE("Resolver Shutdown"), NULL); + r->next_completion = NULL; + } + GRPC_RESOLVER_UNREF(exec_ctx, &r->base, "dns-ares-shutdown"); +} + +static void dns_ares_shutdown(grpc_exec_ctx *exec_ctx, + grpc_resolver *resolver) { + ares_dns_resolver *r = (ares_dns_resolver *)resolver; + GRPC_RESOLVER_REF(&r->base, "dns-ares-shutdown"); + grpc_combiner_execute(exec_ctx, r->combiner, &r->dns_ares_shutdown_locked, + GRPC_ERROR_NONE, false); +} + +static void dns_ares_channel_saw_error_locked(grpc_exec_ctx *exec_ctx, + void *arg, grpc_error *error) { + GPR_ASSERT(error == GRPC_ERROR_NONE); + ares_dns_resolver *r = arg; + if (!r->resolving) { + gpr_backoff_reset(&r->backoff_state); + dns_ares_start_resolving_locked(exec_ctx, r); + } + GRPC_RESOLVER_UNREF(exec_ctx, &r->base, "ares-channel-saw-error"); +} + +static void dns_ares_channel_saw_error(grpc_exec_ctx *exec_ctx, + grpc_resolver *resolver) { + ares_dns_resolver *r = (ares_dns_resolver *)resolver; + GRPC_RESOLVER_REF(&r->base, "ares-channel-saw-error"); + grpc_combiner_execute(exec_ctx, r->combiner, + &r->dns_ares_channel_saw_error_locked, GRPC_ERROR_NONE, + false); +} + +static void dns_ares_on_retry_timer_locked(grpc_exec_ctx *exec_ctx, void *arg, + grpc_error *error) { + ares_dns_resolver *r = arg; + r->have_retry_timer = false; + if (error == GRPC_ERROR_NONE) { + if (!r->resolving) { + dns_ares_start_resolving_locked(exec_ctx, r); + } + } + GRPC_RESOLVER_UNREF(exec_ctx, &r->base, "retry-timer"); +} + +static void dns_ares_on_retry_timer(grpc_exec_ctx *exec_ctx, void *arg, + grpc_error *error) { + ares_dns_resolver *r = arg; + grpc_combiner_execute(exec_ctx, r->combiner, + &r->dns_ares_on_retry_timer_locked, + GRPC_ERROR_REF(error), false); +} + +static void dns_ares_on_resolved_locked(grpc_exec_ctx *exec_ctx, void *arg, + grpc_error *error) { + ares_dns_resolver *r = arg; + grpc_channel_args *result = NULL; + GPR_ASSERT(r->resolving); + r->resolving = false; + if (r->addresses != NULL) { + grpc_lb_addresses *addresses = grpc_lb_addresses_create( + r->addresses->naddrs, NULL /* user_data_vtable */); + for (size_t i = 0; i < r->addresses->naddrs; ++i) { + grpc_lb_addresses_set_address( + addresses, i, &r->addresses->addrs[i].addr, + r->addresses->addrs[i].len, false /* is_balancer */, + NULL /* balancer_name */, NULL /* user_data */); + } + grpc_arg new_arg = grpc_lb_addresses_create_channel_arg(addresses); + result = grpc_channel_args_copy_and_add(r->channel_args, &new_arg, 1); + grpc_resolved_addresses_destroy(r->addresses); + grpc_lb_addresses_destroy(addresses); + } else { + const char *msg = grpc_error_string(error); + gpr_log(GPR_DEBUG, "dns resolution failed: %s", msg); + grpc_error_free_string(msg); + gpr_timespec now = gpr_now(GPR_CLOCK_MONOTONIC); + gpr_timespec next_try = gpr_backoff_step(&r->backoff_state, now); + gpr_timespec timeout = gpr_time_sub(next_try, now); + GPR_ASSERT(!r->have_retry_timer); + r->have_retry_timer = true; + GRPC_RESOLVER_REF(&r->base, "retry-timer"); + if (gpr_time_cmp(timeout, gpr_time_0(timeout.clock_type)) > 0) { + gpr_log(GPR_DEBUG, "retrying in %" PRId64 ".%09d seconds", timeout.tv_sec, + timeout.tv_nsec); + } else { + gpr_log(GPR_DEBUG, "retrying immediately"); + } + grpc_timer_init(exec_ctx, &r->retry_timer, next_try, + dns_ares_on_retry_timer, r, now); + } + if (r->resolved_result != NULL) { + grpc_channel_args_destroy(r->resolved_result); + } + r->resolved_result = result; + r->resolved_version++; + dns_ares_maybe_finish_next_locked(exec_ctx, r); + GRPC_RESOLVER_UNREF(exec_ctx, &r->base, "dns-resolving"); +} + +static void dns_ares_on_resolved(grpc_exec_ctx *exec_ctx, void *arg, + grpc_error *error) { + ares_dns_resolver *r = arg; + grpc_combiner_execute(exec_ctx, r->combiner, &r->dns_ares_on_resolved_locked, + GRPC_ERROR_REF(error), false); +} + +typedef struct dns_ares_next_locked_args { + grpc_resolver *resolver; + grpc_channel_args **target_result; + grpc_closure *on_complete; +} dns_ares_next_locked_args; + +static void dns_ares_next_locked(grpc_exec_ctx *exec_ctx, void *arg, + grpc_error *error) { + GPR_ASSERT(error == GRPC_ERROR_NONE); + dns_ares_next_locked_args *args = arg; + ares_dns_resolver *r = (ares_dns_resolver *)args->resolver; + gpr_log(GPR_DEBUG, "dns_ares_next is called."); + GPR_ASSERT(!r->next_completion); + r->next_completion = args->on_complete; + r->target_result = args->target_result; + gpr_free(arg); + if (r->resolved_version == 0 && !r->resolving) { + gpr_backoff_reset(&r->backoff_state); + dns_ares_start_resolving_locked(exec_ctx, r); + } else { + dns_ares_maybe_finish_next_locked(exec_ctx, r); + } + GRPC_RESOLVER_UNREF(exec_ctx, &r->base, "ares-next"); +} + +static void dns_ares_next(grpc_exec_ctx *exec_ctx, grpc_resolver *resolver, + grpc_channel_args **target_result, + grpc_closure *on_complete) { + ares_dns_resolver *r = (ares_dns_resolver *)resolver; + dns_ares_next_locked_args *args = + gpr_malloc(sizeof(dns_ares_next_locked_args)); + args->target_result = target_result; + args->on_complete = on_complete; + args->resolver = resolver; + GRPC_RESOLVER_REF(resolver, "ares-next"); + grpc_combiner_execute(exec_ctx, r->combiner, + grpc_closure_create(dns_ares_next_locked, args), + GRPC_ERROR_NONE, false); +} + +static void dns_ares_start_resolving_locked(grpc_exec_ctx *exec_ctx, + ares_dns_resolver *r) { + GRPC_RESOLVER_REF(&r->base, "dns-resolving"); + GPR_ASSERT(!r->resolving); + r->resolving = true; + r->addresses = NULL; + grpc_resolve_address( + exec_ctx, r->name_to_resolve, r->default_port, r->base.pollset_set, + grpc_closure_create(dns_ares_on_resolved, r), &r->addresses); +} + +static void dns_ares_maybe_finish_next_locked(grpc_exec_ctx *exec_ctx, + ares_dns_resolver *r) { + if (r->next_completion != NULL && + r->resolved_version != r->published_version) { + *r->target_result = r->resolved_result == NULL + ? NULL + : grpc_channel_args_copy(r->resolved_result); + grpc_exec_ctx_sched(exec_ctx, r->next_completion, GRPC_ERROR_NONE, NULL); + r->next_completion = NULL; + r->published_version = r->resolved_version; + } +} + +static void dns_ares_destroy(grpc_exec_ctx *exec_ctx, grpc_resolver *gr) { + gpr_log(GPR_DEBUG, "dns_ares_destroy"); + ares_dns_resolver *r = (ares_dns_resolver *)gr; + grpc_combiner_destroy(exec_ctx, r->combiner); + if (r->resolved_result != NULL) { + grpc_channel_args_destroy(r->resolved_result); + } + gpr_free(r->name_to_resolve); + gpr_free(r->default_port); + grpc_channel_args_destroy(r->channel_args); + gpr_free(r); +} + +static grpc_resolver *dns_ares_create(grpc_resolver_args *args, + const char *default_port) { + // Get name from args. + const char *path = args->uri->path; + if (0 != strcmp(args->uri->authority, "")) { + gpr_log(GPR_ERROR, "authority based dns uri's not supported"); + return NULL; + } + if (path[0] == '/') ++path; + + // Get proxy name, if any. + char *proxy_name = grpc_get_http_proxy_server(); + // Create resolver. + ares_dns_resolver *r = gpr_malloc(sizeof(ares_dns_resolver)); + memset(r, 0, sizeof(*r)); + grpc_resolver_init(&r->base, &dns_ares_resolver_vtable); + r->combiner = grpc_combiner_create(NULL); + r->name_to_resolve = proxy_name == NULL ? gpr_strdup(path) : proxy_name; + r->default_port = gpr_strdup(default_port); + grpc_arg server_name_arg; + server_name_arg.type = GRPC_ARG_STRING; + server_name_arg.key = GRPC_ARG_SERVER_NAME; + server_name_arg.value.string = (char *)path; + r->channel_args = + grpc_channel_args_copy_and_add(args->args, &server_name_arg, 1); + gpr_backoff_init(&r->backoff_state, BACKOFF_MULTIPLIER, BACKOFF_JITTER, + BACKOFF_MIN_SECONDS * 1000, BACKOFF_MAX_SECONDS * 1000); + grpc_closure_init(&r->dns_ares_shutdown_locked, dns_ares_shutdown_locked, r); + grpc_closure_init(&r->dns_ares_channel_saw_error_locked, + dns_ares_channel_saw_error_locked, r); + grpc_closure_init(&r->dns_ares_on_retry_timer_locked, + dns_ares_on_retry_timer_locked, r); + grpc_closure_init(&r->dns_ares_on_resolved_locked, + dns_ares_on_resolved_locked, r); + return &r->base; +} + +/* + * FACTORY + */ + +static void dns_ares_factory_ref(grpc_resolver_factory *factory) {} + +static void dns_ares_factory_unref(grpc_resolver_factory *factory) {} + +static grpc_resolver *dns_factory_create_resolver( + grpc_resolver_factory *factory, grpc_resolver_args *args) { + return dns_ares_create(args, "https"); +} + +static char *dns_ares_factory_get_default_host_name( + grpc_resolver_factory *factory, grpc_uri *uri) { + const char *path = uri->path; + if (path[0] == '/') ++path; + return gpr_strdup(path); +} + +static const grpc_resolver_factory_vtable dns_ares_factory_vtable = { + dns_ares_factory_ref, dns_ares_factory_unref, dns_factory_create_resolver, + dns_ares_factory_get_default_host_name, "dns"}; +static grpc_resolver_factory dns_resolver_factory = {&dns_ares_factory_vtable}; + +static grpc_resolver_factory *dns_ares_resolver_factory_create() { + return &dns_resolver_factory; +} + +void grpc_resolver_dns_ares_init(void) { + char *resolver = gpr_getenv("GRPC_DNS_RESOLVER"); + if (resolver == NULL || gpr_stricmp(resolver, "ares") == 0) { + grpc_error *error = grpc_ares_init(); + if (error != GRPC_ERROR_NONE) { + GRPC_LOG_IF_ERROR("ares_library_init() failed", error); + return; + } + grpc_resolve_address = grpc_resolve_address_ares; + grpc_register_resolver_type(dns_ares_resolver_factory_create()); + } + gpr_free(resolver); +} + +void grpc_resolver_dns_ares_shutdown(void) { grpc_ares_cleanup(); } + +#else /* GRPC_ARES == 1 */ + +void grpc_resolver_dns_ares_init(void) {} + +void grpc_resolver_dns_ares_shutdown(void) {} + +#endif /* GRPC_ARES == 1 */ diff --git a/src/core/ext/resolver/dns/c_ares/grpc_ares_ev_driver.h b/src/core/ext/resolver/dns/c_ares/grpc_ares_ev_driver.h new file mode 100644 index 0000000000..334feaa2ab --- /dev/null +++ b/src/core/ext/resolver/dns/c_ares/grpc_ares_ev_driver.h @@ -0,0 +1,65 @@ +/* + * + * Copyright 2016, Google Inc. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are + * met: + * + * * Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * * Redistributions in binary form must reproduce the above + * copyright notice, this list of conditions and the following disclaimer + * in the documentation and/or other materials provided with the + * distribution. + * * Neither the name of Google Inc. nor the names of its + * contributors may be used to endorse or promote products derived from + * this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + * + */ + +#ifndef GRPC_CORE_EXT_RESOLVER_DNS_C_ARES_GRPC_ARES_EV_DRIVER_H +#define GRPC_CORE_EXT_RESOLVER_DNS_C_ARES_GRPC_ARES_EV_DRIVER_H + +#include <ares.h> + +#include "src/core/lib/iomgr/exec_ctx.h" +#include "src/core/lib/iomgr/pollset_set.h" + +typedef struct grpc_ares_ev_driver grpc_ares_ev_driver; + +/* Start \a ev_driver. It will keep working until all IO on its ares_channel is + done, or grpc_ares_ev_driver_destroy() is called. It may notify the callbacks + bound to its ares_channel when necessary. */ +void grpc_ares_ev_driver_start(grpc_exec_ctx *exec_ctx, + grpc_ares_ev_driver *ev_driver); + +/* Returns the ares_channel owned by \a ev_driver. To bind a c-ares query to + \a ev_driver, use the ares_channel owned by \a ev_driver as the arg of the + query. */ +ares_channel *grpc_ares_ev_driver_get_channel(grpc_ares_ev_driver *ev_driver); + +/* Creates a new grpc_ares_ev_driver. Returns GRPC_ERROR_NONE if \a ev_driver is + created successfully. */ +grpc_error *grpc_ares_ev_driver_create(grpc_ares_ev_driver **ev_driver, + grpc_pollset_set *pollset_set); + +/* Destroys \a ev_driver asynchronously. Pending lookups made on \a ev_driver + will be cancelled and their on_done callbacks will be invoked with a status + of ARES_ECANCELLED. */ +void grpc_ares_ev_driver_destroy(grpc_ares_ev_driver *ev_driver); + +#endif /* GRPC_CORE_EXT_RESOLVER_DNS_C_ARES_GRPC_ARES_EV_DRIVER_H */ diff --git a/src/core/ext/resolver/dns/c_ares/grpc_ares_ev_driver_fallback.c b/src/core/ext/resolver/dns/c_ares/grpc_ares_ev_driver_fallback.c new file mode 100644 index 0000000000..9d25eb2439 --- /dev/null +++ b/src/core/ext/resolver/dns/c_ares/grpc_ares_ev_driver_fallback.c @@ -0,0 +1,58 @@ +/* + * + * Copyright 2016, Google Inc. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are + * met: + * + * * Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * * Redistributions in binary form must reproduce the above + * copyright notice, this list of conditions and the following disclaimer + * in the documentation and/or other materials provided with the + * distribution. + * * Neither the name of Google Inc. nor the names of its + * contributors may be used to endorse or promote products derived from + * this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + * + */ + +#include <grpc/support/port_platform.h> +#ifdef GRPC_NATIVE_ADDRESS_RESOLVE + +#include "src/core/ext/resolver/dns/c_ares/grpc_ares_ev_driver.h" + +struct grpc_ares_ev_driver { + char unused_member; // unused member to prevent undefined behaviour +}; + +void grpc_ares_ev_driver_start(grpc_exec_ctx *exec_ctx, + grpc_ares_ev_driver *ev_driver) {} + +void *grpc_ares_ev_driver_get_channel(grpc_ares_ev_driver *ev_driver) { + return NULL; +} + +grpc_error *grpc_ares_ev_driver_create(grpc_ares_ev_driver **ev_driver, + grpc_pollset_set *pollset_set) { + return GRPC_ERROR_NONE; +} + +void grpc_ares_ev_driver_destroy(grpc_exec_ctx *exec_ctx, + grpc_ares_ev_driver *ev_driver) {} + +#endif /* GRPC_NATIVE_ADDRESS_RESOLVE */ diff --git a/src/core/ext/resolver/dns/c_ares/grpc_ares_ev_driver_posix.c b/src/core/ext/resolver/dns/c_ares/grpc_ares_ev_driver_posix.c new file mode 100644 index 0000000000..4f7485c5f5 --- /dev/null +++ b/src/core/ext/resolver/dns/c_ares/grpc_ares_ev_driver_posix.c @@ -0,0 +1,319 @@ +/* + * + * Copyright 2016, Google Inc. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are + * met: + * + * * Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * * Redistributions in binary form must reproduce the above + * copyright notice, this list of conditions and the following disclaimer + * in the documentation and/or other materials provided with the + * distribution. + * * Neither the name of Google Inc. nor the names of its + * contributors may be used to endorse or promote products derived from + * this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + * + */ +#include <grpc/support/port_platform.h> +#include "src/core/lib/iomgr/port.h" +#if GRPC_ARES == 1 && defined(GRPC_POSIX_SOCKET) + +#include "src/core/ext/resolver/dns/c_ares/grpc_ares_ev_driver.h" + +#include <grpc/support/alloc.h> +#include <grpc/support/log.h> +#include <grpc/support/string_util.h> +#include <grpc/support/time.h> +#include <grpc/support/useful.h> +#include "src/core/ext/resolver/dns/c_ares/grpc_ares_wrapper.h" +#include "src/core/lib/iomgr/ev_posix.h" +#include "src/core/lib/iomgr/iomgr_internal.h" +#include "src/core/lib/iomgr/sockaddr_utils.h" +#include "src/core/lib/iomgr/unix_sockets_posix.h" +#include "src/core/lib/support/block_annotate.h" +#include "src/core/lib/support/string.h" + +typedef struct fd_node { + /** the owner of this fd node */ + grpc_ares_ev_driver *ev_driver; + /** the grpc_fd owned by this fd node */ + grpc_fd *grpc_fd; + /** a closure wrapping on_readable_cb, which should be invoked when the + grpc_fd in this node becomes readable. */ + grpc_closure read_closure; + /** a closure wrapping on_writable_cb, which should be invoked when the + grpc_fd in this node becomes writable. */ + grpc_closure write_closure; + /** next fd node in the list */ + struct fd_node *next; + + /** mutex guarding the rest of the state */ + gpr_mu mu; + /** if the readable closure has been registered */ + bool readable_registered; + /** if the writable closure has been registered */ + bool writable_registered; +} fd_node; + +struct grpc_ares_ev_driver { + /** the ares_channel owned by this event driver */ + ares_channel channel; + /** pollset set for driving the IO events of the channel */ + grpc_pollset_set *pollset_set; + /** refcount of the event driver */ + gpr_refcount refs; + + /** mutex guarding the rest of the state */ + gpr_mu mu; + /** a list of grpc_fd that this event driver is currently using. */ + fd_node *fds; + /** is this event driver currently working? */ + bool working; + /** is this event driver being shut down */ + bool shutting_down; +}; + +static void grpc_ares_notify_on_event_locked(grpc_exec_ctx *exec_ctx, + grpc_ares_ev_driver *ev_driver); + +static grpc_ares_ev_driver *grpc_ares_ev_driver_ref( + grpc_ares_ev_driver *ev_driver) { + gpr_log(GPR_DEBUG, "Ref ev_driver %" PRIuPTR, (uintptr_t)ev_driver); + gpr_ref(&ev_driver->refs); + return ev_driver; +} + +static void grpc_ares_ev_driver_unref(grpc_ares_ev_driver *ev_driver) { + gpr_log(GPR_DEBUG, "Unref ev_driver %" PRIuPTR, (uintptr_t)ev_driver); + if (gpr_unref(&ev_driver->refs)) { + gpr_log(GPR_DEBUG, "destroy ev_driver %" PRIuPTR, (uintptr_t)ev_driver); + GPR_ASSERT(ev_driver->fds == NULL); + gpr_mu_destroy(&ev_driver->mu); + ares_destroy(ev_driver->channel); + gpr_free(ev_driver); + } +} + +static void fd_node_destroy(grpc_exec_ctx *exec_ctx, fd_node *fdn) { + gpr_log(GPR_DEBUG, "delete fd: %d", grpc_fd_wrapped_fd(fdn->grpc_fd)); + GPR_ASSERT(!fdn->readable_registered); + GPR_ASSERT(!fdn->writable_registered); + gpr_mu_destroy(&fdn->mu); + grpc_pollset_set_del_fd(exec_ctx, fdn->ev_driver->pollset_set, fdn->grpc_fd); + grpc_fd_shutdown(exec_ctx, fdn->grpc_fd); + grpc_fd_orphan(exec_ctx, fdn->grpc_fd, NULL, NULL, "c-ares query finished"); + gpr_free(fdn); +} + +grpc_error *grpc_ares_ev_driver_create(grpc_ares_ev_driver **ev_driver, + grpc_pollset_set *pollset_set) { + *ev_driver = gpr_malloc(sizeof(grpc_ares_ev_driver)); + int status = ares_init(&(*ev_driver)->channel); + gpr_log(GPR_DEBUG, "grpc_ares_ev_driver_create"); + if (status != ARES_SUCCESS) { + char *err_msg; + gpr_asprintf(&err_msg, "Failed to init ares channel. C-ares error: %s", + ares_strerror(status)); + grpc_error *err = GRPC_ERROR_CREATE(err_msg); + gpr_free(err_msg); + gpr_free(*ev_driver); + return err; + } + gpr_mu_init(&(*ev_driver)->mu); + gpr_ref_init(&(*ev_driver)->refs, 1); + (*ev_driver)->pollset_set = pollset_set; + (*ev_driver)->fds = NULL; + (*ev_driver)->working = false; + (*ev_driver)->shutting_down = false; + return GRPC_ERROR_NONE; +} + +void grpc_ares_ev_driver_destroy(grpc_ares_ev_driver *ev_driver) { + // It's not safe to shut down remaining fds here directly, becauses + // ares_host_callback does not provide an exec_ctx. We mark the event driver + // as being shut down. If the event driver is working, + // grpc_ares_notify_on_event_locked will shut down the fds; if it's not + // working, there are no fds to shut down. + gpr_mu_lock(&ev_driver->mu); + ev_driver->shutting_down = true; + gpr_mu_unlock(&ev_driver->mu); + grpc_ares_ev_driver_unref(ev_driver); +} + +// Search fd in the fd_node list head. This is an O(n) search, the max possible +// value of n is ARES_GETSOCK_MAXNUM (16). n is typically 1 - 2 in our tests. +static fd_node *pop_fd_node(fd_node **head, int fd) { + fd_node dummy_head; + dummy_head.next = *head; + fd_node *node = &dummy_head; + while (node->next != NULL) { + if (grpc_fd_wrapped_fd(node->next->grpc_fd) == fd) { + fd_node *ret = node->next; + node->next = node->next->next; + *head = dummy_head.next; + return ret; + } + node = node->next; + } + return NULL; +} + +static void on_readable_cb(grpc_exec_ctx *exec_ctx, void *arg, + grpc_error *error) { + fd_node *fdn = arg; + grpc_ares_ev_driver *ev_driver = fdn->ev_driver; + gpr_mu_lock(&fdn->mu); + fdn->readable_registered = false; + gpr_mu_unlock(&fdn->mu); + + gpr_log(GPR_DEBUG, "readable on %d", grpc_fd_wrapped_fd(fdn->grpc_fd)); + if (error == GRPC_ERROR_NONE) { + ares_process_fd(ev_driver->channel, grpc_fd_wrapped_fd(fdn->grpc_fd), + ARES_SOCKET_BAD); + } else { + // If error is not GRPC_ERROR_NONE, it means the fd has been shutdown or + // timed out. The pending lookups made on this ev_driver will be cancelled + // by the following ares_cancel() and the on_done callbacks will be invoked + // with a status of ARES_ECANCELLED. The remaining file descriptors in this + // ev_driver will be cleaned up in the follwing + // grpc_ares_notify_on_event_locked(). + ares_cancel(ev_driver->channel); + } + gpr_mu_lock(&ev_driver->mu); + grpc_ares_notify_on_event_locked(exec_ctx, ev_driver); + gpr_mu_unlock(&ev_driver->mu); + grpc_ares_ev_driver_unref(ev_driver); +} + +static void on_writable_cb(grpc_exec_ctx *exec_ctx, void *arg, + grpc_error *error) { + fd_node *fdn = arg; + grpc_ares_ev_driver *ev_driver = fdn->ev_driver; + gpr_mu_lock(&fdn->mu); + fdn->writable_registered = false; + gpr_mu_unlock(&fdn->mu); + + gpr_log(GPR_DEBUG, "writable on %d", grpc_fd_wrapped_fd(fdn->grpc_fd)); + if (error == GRPC_ERROR_NONE) { + ares_process_fd(ev_driver->channel, ARES_SOCKET_BAD, + grpc_fd_wrapped_fd(fdn->grpc_fd)); + } else { + // If error is not GRPC_ERROR_NONE, it means the fd has been shutdown or + // timed out. The pending lookups made on this ev_driver will be cancelled + // by the following ares_cancel() and the on_done callbacks will be invoked + // with a status of ARES_ECANCELLED. The remaining file descriptors in this + // ev_driver will be cleaned up in the follwing + // grpc_ares_notify_on_event_locked(). + ares_cancel(ev_driver->channel); + } + gpr_mu_lock(&ev_driver->mu); + grpc_ares_notify_on_event_locked(exec_ctx, ev_driver); + gpr_mu_unlock(&ev_driver->mu); + grpc_ares_ev_driver_unref(ev_driver); +} + +ares_channel *grpc_ares_ev_driver_get_channel(grpc_ares_ev_driver *ev_driver) { + return &ev_driver->channel; +} + +// Get the file descriptors used by the ev_driver's ares channel, register +// driver_closure with these filedescriptors. +static void grpc_ares_notify_on_event_locked(grpc_exec_ctx *exec_ctx, + grpc_ares_ev_driver *ev_driver) { + fd_node *new_list = NULL; + if (!ev_driver->shutting_down) { + ares_socket_t socks[ARES_GETSOCK_MAXNUM]; + int socks_bitmask = + ares_getsock(ev_driver->channel, socks, ARES_GETSOCK_MAXNUM); + for (size_t i = 0; i < ARES_GETSOCK_MAXNUM; i++) { + if (ARES_GETSOCK_READABLE(socks_bitmask, i) || + ARES_GETSOCK_WRITABLE(socks_bitmask, i)) { + fd_node *fdn = pop_fd_node(&ev_driver->fds, socks[i]); + // Create a new fd_node if sock[i] is not in the fd_node list. + if (fdn == NULL) { + char *fd_name; + gpr_asprintf(&fd_name, "ares_ev_driver-%" PRIuPTR, i); + fdn = gpr_malloc(sizeof(fd_node)); + gpr_log(GPR_DEBUG, "new fd: %d", socks[i]); + fdn->grpc_fd = grpc_fd_create(socks[i], fd_name); + fdn->ev_driver = ev_driver; + fdn->readable_registered = false; + fdn->writable_registered = false; + gpr_mu_init(&fdn->mu); + grpc_closure_init(&fdn->read_closure, on_readable_cb, fdn); + grpc_closure_init(&fdn->write_closure, on_writable_cb, fdn); + grpc_pollset_set_add_fd(exec_ctx, ev_driver->pollset_set, + fdn->grpc_fd); + gpr_free(fd_name); + } + fdn->next = new_list; + new_list = fdn; + gpr_mu_lock(&fdn->mu); + // Register read_closure if the socket is readable and read_closure has + // not been registered with this socket. + if (ARES_GETSOCK_READABLE(socks_bitmask, i) && + !fdn->readable_registered) { + grpc_ares_ev_driver_ref(ev_driver); + gpr_log(GPR_DEBUG, "notify read on: %d", + grpc_fd_wrapped_fd(fdn->grpc_fd)); + grpc_fd_notify_on_read(exec_ctx, fdn->grpc_fd, &fdn->read_closure); + fdn->readable_registered = true; + } + // Register write_closure if the socket is writable and write_closure + // has not been registered with this socket. + if (ARES_GETSOCK_WRITABLE(socks_bitmask, i) && + !fdn->writable_registered) { + gpr_log(GPR_DEBUG, "notify write on: %d", + grpc_fd_wrapped_fd(fdn->grpc_fd)); + grpc_ares_ev_driver_ref(ev_driver); + grpc_fd_notify_on_write(exec_ctx, fdn->grpc_fd, &fdn->write_closure); + fdn->writable_registered = true; + } + gpr_mu_unlock(&fdn->mu); + } + } + } + // Any remaining fds in ev_driver->fds were not returned by ares_getsock() and + // are therefore no longer in use, so they can be shut down and removed from + // the list. + while (ev_driver->fds != NULL) { + fd_node *cur = ev_driver->fds; + ev_driver->fds = ev_driver->fds->next; + grpc_fd_shutdown(exec_ctx, cur->grpc_fd); + fd_node_destroy(exec_ctx, cur); + } + ev_driver->fds = new_list; + // If the ev driver has no working fd, all the tasks are done. + if (new_list == NULL) { + ev_driver->working = false; + gpr_log(GPR_DEBUG, "ev driver stop working"); + } +} + +void grpc_ares_ev_driver_start(grpc_exec_ctx *exec_ctx, + grpc_ares_ev_driver *ev_driver) { + gpr_mu_lock(&ev_driver->mu); + if (!ev_driver->working) { + ev_driver->working = true; + grpc_ares_notify_on_event_locked(exec_ctx, ev_driver); + } + gpr_mu_unlock(&ev_driver->mu); +} + +#endif /* GRPC_ARES == 1 && defined(GRPC_POSIX_SOCKET) */ diff --git a/src/core/ext/resolver/dns/c_ares/grpc_ares_wrapper.c b/src/core/ext/resolver/dns/c_ares/grpc_ares_wrapper.c new file mode 100644 index 0000000000..a9e94a509d --- /dev/null +++ b/src/core/ext/resolver/dns/c_ares/grpc_ares_wrapper.c @@ -0,0 +1,285 @@ +/* + * + * Copyright 2016, Google Inc. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are + * met: + * + * * Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * * Redistributions in binary form must reproduce the above + * copyright notice, this list of conditions and the following disclaimer + * in the documentation and/or other materials provided with the + * distribution. + * * Neither the name of Google Inc. nor the names of its + * contributors may be used to endorse or promote products derived from + * this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + * + */ + +#include <grpc/support/port_platform.h> +#if GRPC_ARES == 1 + +#include "src/core/ext/resolver/dns/c_ares/grpc_ares_wrapper.h" +#include "src/core/lib/iomgr/sockaddr.h" +#include "src/core/lib/iomgr/socket_utils_posix.h" + +#include <string.h> +#include <sys/types.h> + +#include <ares.h> +#include <grpc/support/alloc.h> +#include <grpc/support/host_port.h> +#include <grpc/support/log.h> +#include <grpc/support/string_util.h> +#include <grpc/support/thd.h> +#include <grpc/support/time.h> +#include <grpc/support/useful.h> +#include "src/core/ext/resolver/dns/c_ares/grpc_ares_ev_driver.h" +#include "src/core/lib/iomgr/executor.h" +#include "src/core/lib/iomgr/iomgr_internal.h" +#include "src/core/lib/iomgr/sockaddr_utils.h" +#include "src/core/lib/iomgr/unix_sockets_posix.h" +#include "src/core/lib/support/block_annotate.h" +#include "src/core/lib/support/string.h" + +static gpr_once g_basic_init = GPR_ONCE_INIT; +static gpr_mu g_init_mu; + +typedef struct grpc_ares_request { + /** following members are set in grpc_resolve_address_ares_impl */ + /** host to resolve, parsed from the name to resolve */ + char *host; + /** port to fill in sockaddr_in, parsed from the name to resolve */ + char *port; + /** default port to use */ + char *default_port; + /** closure to call when the request completes */ + grpc_closure *on_done; + /** the pointer to receive the resolved addresses */ + grpc_resolved_addresses **addrs_out; + /** the evernt driver used by this request */ + grpc_ares_ev_driver *ev_driver; + /** number of ongoing queries */ + gpr_refcount pending_queries; + + /** mutex guarding the rest of the state */ + gpr_mu mu; + /** is there at least one successful query, set in on_done_cb */ + bool success; + /** the errors explaining the request failure, set in on_done_cb */ + grpc_error *error; +} grpc_ares_request; + +static void do_basic_init(void) { gpr_mu_init(&g_init_mu); } + +static uint16_t strhtons(const char *port) { + if (strcmp(port, "http") == 0) { + return htons(80); + } else if (strcmp(port, "https") == 0) { + return htons(443); + } + return htons((unsigned short)atoi(port)); +} + +static void grpc_ares_request_unref(grpc_exec_ctx *exec_ctx, + grpc_ares_request *r) { + // If there are no pending queries, invoke on_done callback and destroy the + // request + if (gpr_unref(&r->pending_queries)) { + if (exec_ctx == NULL) { + // A new exec_ctx is created here, as the c-ares interface does not + // provide one in ares_host_callback. It's safe to schedule on_done with + // the newly created exec_ctx, since the caller has been warned not to + // acquire locks in on_done. ares_dns_resolver is using combiner to + // protect resources needed by on_done. + grpc_exec_ctx new_exec_ctx = GRPC_EXEC_CTX_INIT; + grpc_exec_ctx_sched(&new_exec_ctx, r->on_done, r->error, NULL); + grpc_exec_ctx_finish(&new_exec_ctx); + } else { + grpc_exec_ctx_sched(exec_ctx, r->on_done, r->error, NULL); + } + gpr_mu_destroy(&r->mu); + grpc_ares_ev_driver_destroy(r->ev_driver); + gpr_free(r->host); + gpr_free(r->port); + gpr_free(r->default_port); + gpr_free(r); + } +} + +static void on_done_cb(void *arg, int status, int timeouts, + struct hostent *hostent) { + grpc_ares_request *r = (grpc_ares_request *)arg; + gpr_mu_lock(&r->mu); + if (status == ARES_SUCCESS) { + GRPC_ERROR_UNREF(r->error); + r->error = GRPC_ERROR_NONE; + r->success = true; + grpc_resolved_addresses **addresses = r->addrs_out; + if (*addresses == NULL) { + *addresses = gpr_malloc(sizeof(grpc_resolved_addresses)); + (*addresses)->naddrs = 0; + (*addresses)->addrs = NULL; + } + size_t prev_naddr = (*addresses)->naddrs; + size_t i; + for (i = 0; hostent->h_addr_list[i] != NULL; i++) { + } + (*addresses)->naddrs += i; + (*addresses)->addrs = + gpr_realloc((*addresses)->addrs, + sizeof(grpc_resolved_address) * (*addresses)->naddrs); + for (i = prev_naddr; i < (*addresses)->naddrs; i++) { + memset(&(*addresses)->addrs[i], 0, sizeof(grpc_resolved_address)); + if (hostent->h_addrtype == AF_INET6) { + (*addresses)->addrs[i].len = sizeof(struct sockaddr_in6); + struct sockaddr_in6 *addr = + (struct sockaddr_in6 *)&(*addresses)->addrs[i].addr; + addr->sin6_family = (sa_family_t)hostent->h_addrtype; + addr->sin6_port = strhtons(r->port); + + char output[INET6_ADDRSTRLEN]; + memcpy(&addr->sin6_addr, hostent->h_addr_list[i - prev_naddr], + sizeof(struct in6_addr)); + ares_inet_ntop(AF_INET6, &addr->sin6_addr, output, INET6_ADDRSTRLEN); + gpr_log(GPR_DEBUG, + "c-ares resolver gets a AF_INET6 result: \n" + " addr: %s\n port: %s\n", + output, r->port); + } else { + (*addresses)->addrs[i].len = sizeof(struct sockaddr_in); + struct sockaddr_in *addr = + (struct sockaddr_in *)&(*addresses)->addrs[i].addr; + memcpy(&addr->sin_addr, hostent->h_addr_list[i - prev_naddr], + sizeof(struct in_addr)); + addr->sin_family = (sa_family_t)hostent->h_addrtype; + addr->sin_port = strhtons(r->port); + + char output[INET_ADDRSTRLEN]; + ares_inet_ntop(AF_INET, &addr->sin_addr, output, INET_ADDRSTRLEN); + gpr_log(GPR_DEBUG, + "c-ares resolver gets a AF_INET result: \n" + " addr: %s\n port: %s\n", + output, r->port); + } + } + } else if (!r->success) { + char *error_msg; + gpr_asprintf(&error_msg, "C-ares status is not ARES_SUCCESS: %s", + ares_strerror(status)); + grpc_error *error = GRPC_ERROR_CREATE(error_msg); + gpr_free(error_msg); + if (r->error == GRPC_ERROR_NONE) { + r->error = error; + } else { + r->error = grpc_error_add_child(error, r->error); + } + } + gpr_mu_unlock(&r->mu); + grpc_ares_request_unref(NULL, r); +} + +void grpc_resolve_address_ares_impl(grpc_exec_ctx *exec_ctx, const char *name, + const char *default_port, + grpc_pollset_set *interested_parties, + grpc_closure *on_done, + grpc_resolved_addresses **addrs) { + /* parse name, splitting it into host and port parts */ + char *host; + char *port; + gpr_split_host_port(name, &host, &port); + if (host == NULL) { + grpc_error *err = + grpc_error_set_str(GRPC_ERROR_CREATE("unparseable host:port"), + GRPC_ERROR_STR_TARGET_ADDRESS, name); + grpc_exec_ctx_sched(exec_ctx, on_done, err, NULL); + goto error_cleanup; + } else if (port == NULL) { + if (default_port == NULL) { + grpc_error *err = grpc_error_set_str(GRPC_ERROR_CREATE("no port in name"), + GRPC_ERROR_STR_TARGET_ADDRESS, name); + grpc_exec_ctx_sched(exec_ctx, on_done, err, NULL); + goto error_cleanup; + } + port = gpr_strdup(default_port); + } + + grpc_ares_ev_driver *ev_driver; + grpc_error *err = grpc_ares_ev_driver_create(&ev_driver, interested_parties); + if (err != GRPC_ERROR_NONE) { + GRPC_LOG_IF_ERROR("grpc_ares_ev_driver_create() failed", err); + goto error_cleanup; + } + + grpc_ares_request *r = gpr_malloc(sizeof(grpc_ares_request)); + gpr_mu_init(&r->mu); + r->ev_driver = ev_driver; + r->on_done = on_done; + r->addrs_out = addrs; + r->default_port = gpr_strdup(default_port); + r->port = port; + r->host = host; + r->success = false; + r->error = GRPC_ERROR_NONE; + ares_channel *channel = grpc_ares_ev_driver_get_channel(r->ev_driver); + // An extra reference is put here to avoid destroying the request in + // on_done_cb before calling grpc_ares_ev_driver_start. + gpr_ref_init(&r->pending_queries, 2); + if (grpc_ipv6_loopback_available()) { + gpr_ref(&r->pending_queries); + ares_gethostbyname(*channel, r->host, AF_INET6, on_done_cb, r); + } + ares_gethostbyname(*channel, r->host, AF_INET, on_done_cb, r); + grpc_ares_ev_driver_start(exec_ctx, ev_driver); + grpc_ares_request_unref(exec_ctx, r); + return; + +error_cleanup: + gpr_free(host); + gpr_free(port); +} + +void (*grpc_resolve_address_ares)( + grpc_exec_ctx *exec_ctx, const char *name, const char *default_port, + grpc_pollset_set *interested_parties, grpc_closure *on_done, + grpc_resolved_addresses **addrs) = grpc_resolve_address_ares_impl; + +grpc_error *grpc_ares_init(void) { + gpr_once_init(&g_basic_init, do_basic_init); + gpr_mu_lock(&g_init_mu); + int status = ares_library_init(ARES_LIB_INIT_ALL); + gpr_mu_unlock(&g_init_mu); + + if (status != ARES_SUCCESS) { + char *error_msg; + gpr_asprintf(&error_msg, "ares_library_init failed: %s", + ares_strerror(status)); + grpc_error *error = GRPC_ERROR_CREATE(error_msg); + gpr_free(error_msg); + return error; + } + return GRPC_ERROR_NONE; +} + +void grpc_ares_cleanup(void) { + gpr_mu_lock(&g_init_mu); + ares_library_cleanup(); + gpr_mu_unlock(&g_init_mu); +} + +#endif /* GRPC_ARES == 1 */ diff --git a/src/core/ext/resolver/dns/c_ares/grpc_ares_wrapper.h b/src/core/ext/resolver/dns/c_ares/grpc_ares_wrapper.h new file mode 100644 index 0000000000..ab00a26b36 --- /dev/null +++ b/src/core/ext/resolver/dns/c_ares/grpc_ares_wrapper.h @@ -0,0 +1,63 @@ +/* + * + * Copyright 2016, Google Inc. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are + * met: + * + * * Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * * Redistributions in binary form must reproduce the above + * copyright notice, this list of conditions and the following disclaimer + * in the documentation and/or other materials provided with the + * distribution. + * * Neither the name of Google Inc. nor the names of its + * contributors may be used to endorse or promote products derived from + * this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + * + */ + +#ifndef GRPC_CORE_EXT_RESOLVER_DNS_C_ARES_GRPC_ARES_WRAPPER_H +#define GRPC_CORE_EXT_RESOLVER_DNS_C_ARES_GRPC_ARES_WRAPPER_H + +#include "src/core/lib/iomgr/exec_ctx.h" +#include "src/core/lib/iomgr/iomgr.h" +#include "src/core/lib/iomgr/polling_entity.h" +#include "src/core/lib/iomgr/resolve_address.h" + +/* Asynchronously resolve addr. Use \a default_port if a port isn't designated + in addr, otherwise use the port in addr. grpc_ares_init() must be called at + least once before this function. \a on_done may be called directly in this + function without being scheduled with \a exec_ctx, it must not try to acquire + locks that are being held by the caller. */ +extern void (*grpc_resolve_address_ares)(grpc_exec_ctx *exec_ctx, + const char *addr, + const char *default_port, + grpc_pollset_set *interested_parties, + grpc_closure *on_done, + grpc_resolved_addresses **addresses); + +/* Initialize gRPC ares wrapper. Must be called at least once before + grpc_resolve_address_ares(). */ +grpc_error *grpc_ares_init(void); + +/* Uninitialized gRPC ares wrapper. If there was more than one previous call to + grpc_ares_init(), this function uninitializes the gRPC ares wrapper only if + it has been called the same number of times as grpc_ares_init(). */ +void grpc_ares_cleanup(void); + +#endif /* GRPC_CORE_EXT_RESOLVER_DNS_C_ARES_GRPC_ARES_WRAPPER_H */ diff --git a/src/core/ext/resolver/dns/c_ares/grpc_ares_wrapper_fallback.c b/src/core/ext/resolver/dns/c_ares/grpc_ares_wrapper_fallback.c new file mode 100644 index 0000000000..05eae51d0d --- /dev/null +++ b/src/core/ext/resolver/dns/c_ares/grpc_ares_wrapper_fallback.c @@ -0,0 +1,58 @@ +/* + * + * Copyright 2016, Google Inc. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are + * met: + * + * * Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * * Redistributions in binary form must reproduce the above + * copyright notice, this list of conditions and the following disclaimer + * in the documentation and/or other materials provided with the + * distribution. + * * Neither the name of Google Inc. nor the names of its + * contributors may be used to endorse or promote products derived from + * this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + * + */ + +/* TODO(zyc): remove this fallback after we can build c-ares on windows */ + +#include <grpc/support/port_platform.h> +#ifdef GRPC_NATIVE_ADDRESS_RESOLVE + +#include "src/core/ext/resolver/dns/c_ares/grpc_ares_wrapper.h" + +void grpc_resolve_address_ares_impl(grpc_exec_ctx *exec_ctx, const char *name, + const char *default_port, + grpc_ares_ev_driver *ev_driver, + grpc_closure *on_done, + grpc_resolved_addresses **addrs) { + grpc_resolve_address(exec_ctx, name, default_port, on_done, addrs); +} + +void (*grpc_resolve_address_ares)( + grpc_exec_ctx *exec_ctx, const char *name, const char *default_port, + grpc_ares_ev_driver *ev_driver, grpc_closure *on_done, + grpc_resolved_addresses **addrs) = grpc_resolve_address_ares_impl; + +grpc_error *grpc_ares_init(void) { return GRPC_ERROR_NONE; } + +void grpc_ares_cleanup(void) {} + +#endif /* GRPC_NATIVE_ADDRESS_RESOLVE */ diff --git a/src/core/ext/resolver/dns/native/dns_resolver.c b/src/core/ext/resolver/dns/native/dns_resolver.c index 655d9dc586..ed5fba3a09 100644 --- a/src/core/ext/resolver/dns/native/dns_resolver.c +++ b/src/core/ext/resolver/dns/native/dns_resolver.c @@ -44,6 +44,7 @@ #include "src/core/lib/iomgr/resolve_address.h" #include "src/core/lib/iomgr/timer.h" #include "src/core/lib/support/backoff.h" +#include "src/core/lib/support/env.h" #include "src/core/lib/support/string.h" #define GRPC_DNS_MIN_CONNECT_TIMEOUT_SECONDS 1 @@ -317,7 +318,21 @@ static grpc_resolver_factory *dns_resolver_factory_create() { } void grpc_resolver_dns_native_init(void) { - grpc_register_resolver_type(dns_resolver_factory_create()); + char *resolver = gpr_getenv("GRPC_DNS_RESOLVER"); + if (resolver != NULL && gpr_stricmp(resolver, "native") == 0) { + gpr_log(GPR_DEBUG, "Using native dns resolver"); + grpc_register_resolver_type(dns_resolver_factory_create()); + } else { + grpc_resolver_factory *existing_factory = + grpc_resolver_factory_lookup("dns"); + if (existing_factory == NULL) { + gpr_log(GPR_DEBUG, "Using native dns resolver"); + grpc_register_resolver_type(dns_resolver_factory_create()); + } else { + grpc_resolver_factory_unref(existing_factory); + } + } + gpr_free(resolver); } void grpc_resolver_dns_native_shutdown(void) {} |