text: /*
   *
   * Copyright 2015 gRPC authors.
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *     http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   *
   */
  
  #include <grpc/support/port_platform.h>
  
  #include "src/core/lib/iomgr/port.h"
  #ifdef GRPC_POSIX_SOCKET_RESOLVE_ADDRESS
  
  #include "src/core/lib/iomgr/sockaddr.h"
  
  #include "src/core/lib/iomgr/resolve_address.h"
  
  #include <string.h>
  #include <sys/types.h>
  
  #include <grpc/support/alloc.h>
  #include <grpc/support/log.h>
  #include <grpc/support/string_util.h>
  #include <grpc/support/time.h>
  
  #include "src/core/lib/gpr/host_port.h"
  #include "src/core/lib/gpr/string.h"
  #include "src/core/lib/gpr/useful.h"
  #include "src/core/lib/gprpp/thd.h"
  #include "src/core/lib/iomgr/block_annotate.h"
  #include "src/core/lib/iomgr/executor.h"
  #include "src/core/lib/iomgr/iomgr_internal.h"
  #include "src/core/lib/iomgr/unix_sockets_posix.h"
  
  static grpc_error* posix_blocking_resolve_address(
      const char* name, const char* default_port,
      grpc_resolved_addresses** addresses) {
    grpc_core::ExecCtx exec_ctx;
    struct addrinfo hints;
    struct addrinfo *result = nullptr, *resp;
    char* host;
    char* port;
    int s;
    size_t i;
    grpc_error* err;
  
    gpr_log(GPR_INFO, "resolving address now for %s", name);
  
    if (name[0] == 'u' && name[1] == 'n' && name[2] == 'i' && name[3] == 'x' &&
        name[4] == ':' && name[5] != 0) {
      return grpc_resolve_unix_domain_address(name + 5, addresses);
    }
  
    /* parse name, splitting it into host and port parts */
    gpr_split_host_port(name, &host, &port);
    if (host == nullptr) {
      err = grpc_error_set_str(
          GRPC_ERROR_CREATE_FROM_STATIC_STRING("unparseable host:port"),
          GRPC_ERROR_STR_TARGET_ADDRESS, grpc_slice_from_copied_string(name));
      goto done;
    }
    if (port == nullptr) {
      if (default_port == nullptr) {
        err = grpc_error_set_str(
            GRPC_ERROR_CREATE_FROM_STATIC_STRING("no port in name"),
            GRPC_ERROR_STR_TARGET_ADDRESS, grpc_slice_from_copied_string(name));
        goto done;
      }
      port = gpr_strdup(default_port);
    }
  
    /* Call getaddrinfo */
    memset(&hints, 0, sizeof(hints));
    hints.ai_family = AF_UNSPEC;     /* ipv4 or ipv6 */
    hints.ai_socktype = SOCK_STREAM; /* stream socket */
    hints.ai_flags = AI_PASSIVE;     /* for wildcard IP address */
  
    GRPC_SCHEDULING_START_BLOCKING_REGION;
    s = getaddrinfo(host, port, &hints, &result);
    GRPC_SCHEDULING_END_BLOCKING_REGION;
  
    if (s != 0) {
      /* Retry if well-known service name is recognized */
      const char* svc[][2] = {{"http", "80"}, {"https", "443"}};
      for (i = 0; i < GPR_ARRAY_SIZE(svc); i++) {
        if (strcmp(port, svc[i][0]) == 0) {
          GRPC_SCHEDULING_START_BLOCKING_REGION;
          s = getaddrinfo(host, svc[i][1], &hints, &result);
          GRPC_SCHEDULING_END_BLOCKING_REGION;
          break;
        }
      }
    }
  
    if (s != 0) {
      err = grpc_error_set_str(
          grpc_error_set_str(
              grpc_error_set_str(
                  grpc_error_set_int(
                      GRPC_ERROR_CREATE_FROM_STATIC_STRING(gai_strerror(s)),
                      GRPC_ERROR_INT_ERRNO, s),
                  GRPC_ERROR_STR_OS_ERROR,
                  grpc_slice_from_static_string(gai_strerror(s))),
              GRPC_ERROR_STR_SYSCALL,
              grpc_slice_from_static_string("getaddrinfo")),
          GRPC_ERROR_STR_TARGET_ADDRESS, grpc_slice_from_copied_string(name));
      goto done;
    }
  
    /* Success path: set addrs non-NULL, fill it in */
    *addresses = static_cast<grpc_resolved_addresses*>(
        gpr_malloc(sizeof(grpc_resolved_addresses)));
    (*addresses)->naddrs = 0;
    for (resp = result; resp != nullptr; resp = resp->ai_next) {
      (*addresses)->naddrs++;
    }
    (*addresses)->addrs = static_cast<grpc_resolved_address*>(
        gpr_malloc(sizeof(grpc_resolved_address) * (*addresses)->naddrs));
    i = 0;
    for (resp = result; resp != nullptr; resp = resp->ai_next) {
      memcpy(&(*addresses)->addrs[i].addr, resp->ai_addr, resp->ai_addrlen);
      (*addresses)->addrs[i].len = resp->ai_addrlen;
      i++;
    }
    err = GRPC_ERROR_NONE;
  
  done:
    gpr_free(host);
    gpr_free(port);
    if (result) {
      freeaddrinfo(result);
    }
    return err;
  }
  
  typedef struct {
    char* name;
    char* default_port;
    grpc_closure* on_done;
    grpc_resolved_addresses** addrs_out;
    grpc_closure request_closure;
    void* arg;
  } request;
  
  /* Callback to be passed to grpc Executor to asynch-ify
   * grpc_blocking_resolve_address */
  static void do_request_thread(void* rp, grpc_error* error) {
    request* r = static_cast<request*>(rp);
    GRPC_CLOSURE_SCHED(r->on_done, grpc_blocking_resolve_address(
                                       r->name, r->default_port, r->addrs_out));
    gpr_free(r->name);
    gpr_free(r->default_port);
    gpr_free(r);
  }
  
  static void posix_resolve_address(const char* name, const char* default_port,
                                    grpc_pollset_set* interested_parties,
                                    grpc_closure* on_done,
                                    grpc_resolved_addresses** addrs) {
    request* r = static_cast<request*>(gpr_malloc(sizeof(request)));
    GRPC_CLOSURE_INIT(
        &r->request_closure, do_request_thread, r,
        grpc_core::Executor::Scheduler(grpc_core::ExecutorType::RESOLVER,
                                       grpc_core::ExecutorJobType::SHORT));
    r->name = gpr_strdup(name);
    r->default_port = gpr_strdup(default_port);
    r->on_done = on_done;
    r->addrs_out = addrs;
    GRPC_CLOSURE_SCHED(&r->request_closure, GRPC_ERROR_NONE);
  }
  
  grpc_address_resolver_vtable grpc_posix_resolver_vtable = {
      posix_resolve_address, posix_blocking_resolve_address};
  #endif
  