C++ Curl_printable_address函数代码示例

static void dump_addrinfo (struct connectdata *conn, const struct addrinfo *ai)
{
  TRACE(("dump_addrinfo:\n"));
  for ( ; ai; ai = ai->ai_next) {
    char  buf [INET6_ADDRSTRLEN];

    trace_it("    fam %2d, CNAME %s, ",
             ai->ai_family, ai->ai_canonname ? ai->ai_canonname : "<none>");
    if (Curl_printable_address(ai, buf, sizeof(buf)))
      trace_it("%s\n", buf);
    else
      trace_it("failed; %s\n", Curl_strerror(conn, SOCKERRNO));
  }
}

CURLcode Curl_store_ip_addr(struct connectdata *conn)
{
  char addrbuf[256];
  Curl_printable_address(conn->ip_addr, addrbuf, sizeof(addrbuf));

  /* save the string */
  Curl_safefree(conn->ip_addr_str);
  conn->ip_addr_str = strdup(addrbuf);
  if(!conn->ip_addr_str)
    return CURLE_OUT_OF_MEMORY; /* FAIL */

#ifdef PF_INET6
  if(conn->ip_addr->ai_family == PF_INET6)
    conn->bits.ipv6 = TRUE;
#endif

  return CURLE_OK;
}

/* singleipconnect() connects to the given IP only, and it may return without
   having connected if used from the multi interface. */
static curl_socket_t
singleipconnect(struct connectdata *conn,
                const Curl_addrinfo *ai,
                long timeout_ms,
                bool *connected)
{
  char addr_buf[128];
  int rc;
  int error;
  bool isconnected;
  struct SessionHandle *data = conn->data;
  curl_socket_t sockfd;
  CURLcode res;

  sockfd = socket(ai->ai_family, conn->socktype, ai->ai_protocol);
  if (sockfd == CURL_SOCKET_BAD)
    return CURL_SOCKET_BAD;

  *connected = FALSE; /* default is not connected */

  Curl_printable_address(ai, addr_buf, sizeof(addr_buf));
  infof(data, "  Trying %s... ", addr_buf);

  if(data->set.tcp_nodelay)
    tcpnodelay(conn, sockfd);

  nosigpipe(conn, sockfd);

  if(data->set.fsockopt) {
    /* activate callback for setting socket options */
    error = data->set.fsockopt(data->set.sockopt_client,
                               sockfd,
                               CURLSOCKTYPE_IPCXN);
    if (error) {
      sclose(sockfd); /* close the socket and bail out */
      return CURL_SOCKET_BAD;
    }
  }

  /* possibly bind the local end to an IP, interface or port */
  res = bindlocal(conn, sockfd);
  if(res) {
    sclose(sockfd); /* close socket and bail out */
    return CURL_SOCKET_BAD;
  }

  /* set socket non-blocking */
  Curl_nonblock(sockfd, TRUE);

  /* Connect TCP sockets, bind UDP */
  if(conn->socktype == SOCK_STREAM)
    rc = connect(sockfd, ai->ai_addr, ai->ai_addrlen);
  else
    rc = 0;

  if(-1 == rc) {
    error = Curl_sockerrno();

    switch (error) {
    case EINPROGRESS:
    case EWOULDBLOCK:
#if defined(EAGAIN) && EAGAIN != EWOULDBLOCK
      /* On some platforms EAGAIN and EWOULDBLOCK are the
       * same value, and on others they are different, hence
       * the odd #if
       */
    case EAGAIN:
#endif
      rc = waitconnect(sockfd, timeout_ms);
      break;
    default:
      /* unknown error, fallthrough and try another address! */
      failf(data, "Failed to connect to %s: %s",
            addr_buf, Curl_strerror(conn,error));
      data->state.os_errno = error;
      break;
    }
  }

  /* The 'WAITCONN_TIMEOUT == rc' comes from the waitconnect(), and not from
     connect(). We can be sure of this since connect() cannot return 1. */
  if((WAITCONN_TIMEOUT == rc) &&
     (data->state.used_interface == Curl_if_multi)) {
    /* Timeout when running the multi interface */
    return sockfd;
  }

  isconnected = verifyconnect(sockfd, &error);

  if(!rc && isconnected) {
    /* we are connected, awesome! */
    *connected = TRUE; /* this is a true connect */
    infof(data, "connected\n");
    return sockfd;
  }
  else if(WAITCONN_TIMEOUT == rc)
    infof(data, "Timeout\n");
  else {
//.........这里部分代码省略.........

static CURLcode bindlocal(struct connectdata *conn,
                          curl_socket_t sockfd, int af)
{
    struct SessionHandle *data = conn->data;

    struct Curl_sockaddr_storage sa;
    struct sockaddr *sock = (struct sockaddr *)&sa;  /* bind to this address */
    curl_socklen_t sizeof_sa = 0; /* size of the data sock points to */
    struct sockaddr_in *si4 = (struct sockaddr_in *)&sa;
#ifdef ENABLE_IPV6
    struct sockaddr_in6 *si6 = (struct sockaddr_in6 *)&sa;
#endif

    struct Curl_dns_entry *h=NULL;
    unsigned short port = data->set.localport; /* use this port number, 0 for
                                                "random" */
    /* how many port numbers to try to bind to, increasing one at a time */
    int portnum = data->set.localportrange;
    const char *dev = data->set.str[STRING_DEVICE];
    int error;
    char myhost[256] = "";
    int done = 0; /* -1 for error, 1 for address found */

    /*************************************************************
     * Select device to bind socket to
     *************************************************************/
    if ( !dev && !port )
        /* no local kind of binding was requested */
        return CURLE_OK;

    memset(&sa, 0, sizeof(struct Curl_sockaddr_storage));

    if(dev && (strlen(dev)<255) ) {

        /* interface */
        if(Curl_if2ip(af, dev, myhost, sizeof(myhost))) {
            /*
             * We now have the numerical IP address in the 'myhost' buffer
             */
            infof(data, "Local Interface %s is ip %s using address family %i\n",
                  dev, myhost, af);
            done = 1;

#ifdef SO_BINDTODEVICE
            /* I am not sure any other OSs than Linux that provide this feature, and
             * at the least I cannot test. --Ben
             *
             * This feature allows one to tightly bind the local socket to a
             * particular interface.  This will force even requests to other local
             * interfaces to go out the external interface.
             *
             *
             * Only bind to the interface when specified as interface, not just as a
             * hostname or ip address.
             */
            if(setsockopt(sockfd, SOL_SOCKET, SO_BINDTODEVICE,
                          dev, (curl_socklen_t)strlen(dev)+1) != 0) {
                error = SOCKERRNO;
                infof(data, "SO_BINDTODEVICE %s failed with errno %d: %s;"
                      " will do regular bind\n",
                      dev, error, Curl_strerror(conn, error));
                /* This is typically "errno 1, error: Operation not permitted" if
                   you're not running as root or another suitable privileged user */
            }
#endif
        }
        else {
            /*
             * This was not an interface, resolve the name as a host name
             * or IP number
             *
             * Temporarily force name resolution to use only the address type
             * of the connection. The resolve functions should really be changed
             * to take a type parameter instead.
             */
            long ipver = data->set.ip_version;
            int rc;

            if (af == AF_INET)
                data->set.ip_version = CURL_IPRESOLVE_V4;
#ifdef ENABLE_IPV6
            else if (af == AF_INET6)
                data->set.ip_version = CURL_IPRESOLVE_V6;
#endif

            rc = Curl_resolv(conn, dev, 0, &h);
            if(rc == CURLRESOLV_PENDING)
                (void)Curl_wait_for_resolv(conn, &h);
            data->set.ip_version = ipver;

            if(h) {
                /* convert the resolved address, sizeof myhost >= INET_ADDRSTRLEN */
                Curl_printable_address(h->addr, myhost, sizeof(myhost));
                infof(data, "Name '%s' family %i resolved to '%s' family %i\n",
                      dev, af, myhost, h->addr->ai_family);
                Curl_resolv_unlock(data, h);
                done = 1;
            }
            else {
                /*
//.........这里部分代码省略.........

//.........这里部分代码省略.........

#ifdef mpeix
    /* Call this function once now, and ignore the results. We do this to
       "clear" the error state on the socket so that we can later read it
       reliably. This is reported necessary on the MPE/iX operating system. */
    (void)verifyconnect(conn->tempsock[i], NULL);
#endif

    /* check socket for connect */
    rc = Curl_socket_ready(CURL_SOCKET_BAD, conn->tempsock[i], 0);

    if(rc == 0) { /* no connection yet */
      if(curlx_tvdiff(now, conn->connecttime) >= conn->timeoutms_per_addr) {
        infof(data, "After %ldms connect time, move on!\n",
              conn->timeoutms_per_addr);
        error = ETIMEDOUT;
      }

      /* should we try another protocol family? */
      if(i == 0 && conn->tempaddr[1] == NULL &&
         curlx_tvdiff(now, conn->connecttime) >= HAPPY_EYEBALLS_TIMEOUT) {
        trynextip(conn, sockindex, 1);
      }
    }
    else if(rc == CURL_CSELECT_OUT) {
      if(verifyconnect(conn->tempsock[i], &error)) {
        /* we are connected with TCP, awesome! */
        int other = i ^ 1;

        /* use this socket from now on */
        conn->sock[sockindex] = conn->tempsock[i];
        conn->ip_addr = conn->tempaddr[i];
        conn->tempsock[i] = CURL_SOCKET_BAD;

        /* close the other socket, if open */
        if(conn->tempsock[other] != CURL_SOCKET_BAD) {
          Curl_closesocket(conn, conn->tempsock[other]);
          conn->tempsock[other] = CURL_SOCKET_BAD;
        }

        /* see if we need to do any proxy magic first once we connected */
        result = Curl_connected_proxy(conn, sockindex);
        if(result)
          return result;

        conn->bits.tcpconnect[sockindex] = TRUE;

        *connected = TRUE;
        if(sockindex == FIRSTSOCKET)
          Curl_pgrsTime(data, TIMER_CONNECT); /* connect done */
        Curl_updateconninfo(conn, conn->sock[sockindex]);
        Curl_verboseconnect(conn);

        return CURLE_OK;
      }
      else
        infof(data, "Connection failed\n");
    }
    else if(rc & CURL_CSELECT_ERR)
      (void)verifyconnect(conn->tempsock[i], &error);

    /*
     * The connection failed here, we should attempt to connect to the "next
     * address" for the given host. But first remember the latest error.
     */
    if(error) {
      data->state.os_errno = error;
      SET_SOCKERRNO(error);
      if(conn->tempaddr[i]) {
        char ipaddress[MAX_IPADR_LEN];
        Curl_printable_address(conn->tempaddr[i], ipaddress, MAX_IPADR_LEN);
        infof(data, "connect to %s port %ld failed: %s\n",
              ipaddress, conn->port, Curl_strerror(conn, error));

        conn->timeoutms_per_addr = conn->tempaddr[i]->ai_next == NULL ?
                                   allow : allow / 2;

        result = trynextip(conn, sockindex, i);
      }
    }
  }

  if(result) {
    /* no more addresses to try */

    /* if the first address family runs out of addresses to try before
       the happy eyeball timeout, go ahead and try the next family now */
    if(conn->tempaddr[1] == NULL) {
      result = trynextip(conn, sockindex, 1);
      if(!result)
        return result;
    }

    failf(data, "Failed to connect to %s port %ld: %s",
          conn->bits.proxy?conn->proxy.name:conn->host.name,
          conn->port, Curl_strerror(conn, error));
  }

  return result;
}

//.........这里部分代码省略.........

    socksreq[3] = 3; /* ATYP: domain name = 3 */
    socksreq[4] = (char) hostname_len; /* address length */
    memcpy(&socksreq[5], hostname, hostname_len); /* address bytes w/o NULL */

    *((unsigned short*)&socksreq[hostname_len+5]) =
      htons((unsigned short)remote_port);
  }
  else {
    struct Curl_dns_entry *dns;
    Curl_addrinfo *hp=NULL;
    int rc = Curl_resolv(conn, hostname, remote_port, &dns);

    packetsize = 10;

    socksreq[3] = 1; /* IPv4 = 1 */

    if(rc == CURLRESOLV_ERROR)
      return CURLE_COULDNT_RESOLVE_HOST;

    if(rc == CURLRESOLV_PENDING)
      /* this requires that we're in "wait for resolve" state */
      rc = Curl_wait_for_resolv(conn, &dns);

    /*
     * We cannot use 'hostent' as a struct that Curl_resolv() returns.  It
     * returns a Curl_addrinfo pointer that may not always look the same.
     */
    if(dns)
      hp=dns->addr;
    if(hp) {
      char buf[64];
      unsigned short ip[4];
      Curl_printable_address(hp, buf, sizeof(buf));

      if(4 == sscanf( buf, "%hu.%hu.%hu.%hu",
                      &ip[0], &ip[1], &ip[2], &ip[3])) {
        socksreq[4] = (unsigned char)ip[0];
        socksreq[5] = (unsigned char)ip[1];
        socksreq[6] = (unsigned char)ip[2];
        socksreq[7] = (unsigned char)ip[3];
      }
      else
        hp = NULL; /* fail! */

      Curl_resolv_unlock(data, dns); /* not used anymore from now on */
    }
    if(!hp) {
      failf(data, "Failed to resolve \"%s\" for SOCKS5 connect.",
            hostname);
      return CURLE_COULDNT_RESOLVE_HOST;
    }

    *((unsigned short*)&socksreq[8]) = htons((unsigned short)remote_port);
  }

  code = Curl_write_plain(conn, sock, (char *)socksreq, packetsize, &written);
  if((code != CURLE_OK) || (written != packetsize)) {
    failf(data, "Failed to send SOCKS5 connect request.");
    return CURLE_COULDNT_CONNECT;
  }

  packetsize = 10; /* minimum packet size is 10 */

  result = blockread_all(conn, sock, (char *)socksreq, packetsize,
                           &actualread, timeout);

//.........这里部分代码省略.........
              " that the SOCKS5 server wanted a username/password, since none"
              " was supplied to the server on this connection.)");
      }
      else {
        failf(data, "No authentication method was acceptable.");
      }
      return CURLE_COULDNT_CONNECT;
    }
    else {
      failf(data,
            "Undocumented SOCKS5 mode attempted to be used by server.");
      return CURLE_COULDNT_CONNECT;
    }
  }

  /* Authentication is complete, now specify destination to the proxy */
  socksreq[0] = 5; /* version (SOCKS5) */
  socksreq[1] = 1; /* connect */
  socksreq[2] = 0; /* must be zero */
  socksreq[3] = 1; /* IPv4 = 1 */

  {
    struct Curl_dns_entry *dns;
    Curl_addrinfo *hp=NULL;
    int rc = Curl_resolv(conn, conn->host.name, (int)conn->remote_port, &dns);

    if(rc == CURLRESOLV_ERROR)
      return CURLE_COULDNT_RESOLVE_HOST;

    if(rc == CURLRESOLV_PENDING)
      /* this requires that we're in "wait for resolve" state */
      rc = Curl_wait_for_resolv(conn, &dns);

    /*
     * We cannot use 'hostent' as a struct that Curl_resolv() returns.  It
     * returns a Curl_addrinfo pointer that may not always look the same.
     */
    if(dns)
      hp=dns->addr;
    if (hp) {
      char buf[64];
      unsigned short ip[4];
      Curl_printable_address(hp, buf, sizeof(buf));

      if(4 == sscanf( buf, "%hu.%hu.%hu.%hu",
                      &ip[0], &ip[1], &ip[2], &ip[3])) {
        socksreq[4] = (unsigned char)ip[0];
        socksreq[5] = (unsigned char)ip[1];
        socksreq[6] = (unsigned char)ip[2];
        socksreq[7] = (unsigned char)ip[3];
      }
      else
        hp = NULL; /* fail! */

      Curl_resolv_unlock(data, dns); /* not used anymore from now on */
    }
    if(!hp) {
      failf(data, "Failed to resolve \"%s\" for SOCKS5 connect.",
            conn->host.name);
      return CURLE_COULDNT_RESOLVE_HOST;
    }
  }

  *((unsigned short*)&socksreq[8]) = htons(conn->remote_port);

  {
    const int packetsize = 10;

    code = Curl_write(conn, sock, (char *)socksreq, packetsize, &written);
    if ((code != CURLE_OK) || (written != packetsize)) {
      failf(data, "Failed to send SOCKS5 connect request.");
      return CURLE_COULDNT_CONNECT;
    }

    result = blockread_all(conn, sock, (char *)socksreq, packetsize,
                           &actualread, timeout);
    if ((result != CURLE_OK) || (actualread != packetsize)) {
      failf(data, "Failed to receive SOCKS5 connect request ack.");
      return CURLE_COULDNT_CONNECT;
    }

    if (socksreq[0] != 5) { /* version */
      failf(data,
            "SOCKS5 reply has wrong version, version should be 5.");
      return CURLE_COULDNT_CONNECT;
    }
    if (socksreq[1] != 0) { /* Anything besides 0 is an error */
        failf(data,
              "Can't complete SOCKS5 connection to %d.%d.%d.%d:%d. (%d)",
              (unsigned char)socksreq[4], (unsigned char)socksreq[5],
              (unsigned char)socksreq[6], (unsigned char)socksreq[7],
              (unsigned int)ntohs(*(unsigned short*)(&socksreq[8])),
              socksreq[1]);
        return CURLE_COULDNT_CONNECT;
    }
  }

  Curl_nonblock(sock, TRUE);
  return CURLE_OK; /* Proxy was successful! */
}

/*
* This function logs in to a SOCKS4 proxy and sends the specifics to the final
* destination server.
*
* Reference :
*   http://socks.permeo.com/protocol/socks4.protocol
*
* Note :
*   Set protocol4a=true for  "SOCKS 4A (Simple Extension to SOCKS 4 Protocol)"
*   Nonsupport "Identification Protocol (RFC1413)"
*/
CURLcode Curl_SOCKS4(const char *proxy_name,
                     const char *hostname,
                     int remote_port,
                     int sockindex,
                     struct connectdata *conn,
                     bool protocol4a)
{
#define SOCKS4REQLEN 262
  unsigned char socksreq[SOCKS4REQLEN]; /* room for SOCKS4 request incl. user
                                           id */
  int result;
  CURLcode code;
  curl_socket_t sock = conn->sock[sockindex];
  long timeout;
  struct SessionHandle *data = conn->data;

  /* get timeout */
  timeout = Curl_timeleft(conn, NULL, TRUE);

  if(timeout < 0) {
    /* time-out, bail out, go home */
    failf(data, "Connection time-out");
    return CURLE_OPERATION_TIMEDOUT;
  }

  Curl_nonblock(sock, FALSE);

  /*
   * Compose socks4 request
   *
   * Request format
   *
   *     +----+----+----+----+----+----+----+----+----+----+....+----+
   *     | VN | CD | DSTPORT |      DSTIP        | USERID       |NULL|
   *     +----+----+----+----+----+----+----+----+----+----+....+----+
   * # of bytes:  1    1      2              4           variable       1
   */

  socksreq[0] = 4; /* version (SOCKS4) */
  socksreq[1] = 1; /* connect */
  *((unsigned short*)&socksreq[2]) = htons((unsigned short)remote_port);

  /* DNS resolve only for SOCKS4, not SOCKS4a */
  if (!protocol4a) {
    struct Curl_dns_entry *dns;
    Curl_addrinfo *hp=NULL;
    int rc;

    rc = Curl_resolv(conn, hostname, remote_port, &dns);

    if(rc == CURLRESOLV_ERROR)
      return CURLE_COULDNT_RESOLVE_PROXY;

    if(rc == CURLRESOLV_PENDING)
      /* this requires that we're in "wait for resolve" state */
      rc = Curl_wait_for_resolv(conn, &dns);

    /*
     * We cannot use 'hostent' as a struct that Curl_resolv() returns.  It
     * returns a Curl_addrinfo pointer that may not always look the same.
     */
    if(dns)
      hp=dns->addr;
    if(hp) {
      char buf[64];
      unsigned short ip[4];
      Curl_printable_address(hp, buf, sizeof(buf));

      if(4 == sscanf( buf, "%hu.%hu.%hu.%hu",
                      &ip[0], &ip[1], &ip[2], &ip[3])) {
        /* Set DSTIP */
        socksreq[4] = (unsigned char)ip[0];
        socksreq[5] = (unsigned char)ip[1];
        socksreq[6] = (unsigned char)ip[2];
        socksreq[7] = (unsigned char)ip[3];
      }
      else
        hp = NULL; /* fail! */

      Curl_resolv_unlock(data, dns); /* not used anymore from now on */

    }
    if(!hp) {
      failf(data, "Failed to resolve \"%s\" for SOCKS4 connect.",
            hostname);
      return CURLE_COULDNT_RESOLVE_HOST;
    }
  }

//.........这里部分代码省略.........

/*
* This function logs in to a SOCKS4 proxy and sends the specifics to the final
* destination server.
*
* Reference :
*   http://socks.permeo.com/protocol/socks4.protocol
*
* Note :
*   Nonsupport "SOCKS 4A (Simple Extension to SOCKS 4 Protocol)"
*   Nonsupport "Identification Protocol (RFC1413)"
*/
CURLcode Curl_SOCKS4(const char *proxy_name,
                     struct connectdata *conn)
{
  unsigned char socksreq[262]; /* room for SOCKS4 request incl. user id */
  int result;
  CURLcode code;
  curl_socket_t sock = conn->sock[FIRSTSOCKET];
  long timeout;
  struct SessionHandle *data = conn->data;

  /* get timeout */
  if(data->set.timeout && data->set.connecttimeout) {
    if (data->set.timeout < data->set.connecttimeout)
      timeout = data->set.timeout*1000;
    else
      timeout = data->set.connecttimeout*1000;
  }
  else if(data->set.timeout)
    timeout = data->set.timeout*1000;
  else if(data->set.connecttimeout)
    timeout = data->set.connecttimeout*1000;
  else
    timeout = DEFAULT_CONNECT_TIMEOUT;

  Curl_nonblock(sock, FALSE);

  /*
   * Compose socks4 request
   *
   * Request format
   *
   *     +----+----+----+----+----+----+----+----+----+----+....+----+
   *     | VN | CD | DSTPORT |      DSTIP        | USERID       |NULL|
   *     +----+----+----+----+----+----+----+----+----+----+....+----+
   * # of bytes:  1    1      2              4           variable       1
   */

  socksreq[0] = 4; /* version (SOCKS4) */
  socksreq[1] = 1; /* connect */
  *((unsigned short*)&socksreq[2]) = htons(conn->remote_port);

  /* DNS resolve */
  {
    struct Curl_dns_entry *dns;
    Curl_addrinfo *hp=NULL;
    int rc;

    rc = Curl_resolv(conn, conn->host.name, (int)conn->remote_port, &dns);

    if(rc == CURLRESOLV_ERROR)
      return CURLE_COULDNT_RESOLVE_PROXY;

    if(rc == CURLRESOLV_PENDING)
      /* this requires that we're in "wait for resolve" state */
      rc = Curl_wait_for_resolv(conn, &dns);

    /*
     * We cannot use 'hostent' as a struct that Curl_resolv() returns.  It
     * returns a Curl_addrinfo pointer that may not always look the same.
     */
    if(dns)
      hp=dns->addr;
    if (hp) {
      char buf[64];
      unsigned short ip[4];
      Curl_printable_address(hp, buf, sizeof(buf));

      if(4 == sscanf( buf, "%hu.%hu.%hu.%hu",
                      &ip[0], &ip[1], &ip[2], &ip[3])) {
        /* Set DSTIP */
        socksreq[4] = (unsigned char)ip[0];
        socksreq[5] = (unsigned char)ip[1];
        socksreq[6] = (unsigned char)ip[2];
        socksreq[7] = (unsigned char)ip[3];
      }
      else
        hp = NULL; /* fail! */

      Curl_resolv_unlock(data, dns); /* not used anymore from now on */

    }
    if(!hp) {
      failf(data, "Failed to resolve \"%s\" for SOCKS4 connect.",
            conn->host.name);
      return CURLE_COULDNT_RESOLVE_HOST;
    }
  }

  /*
//.........这里部分代码省略.........

/* singleipconnect() connects to the given IP only, and it may return without
   having connected if used from the multi interface. */
static curl_socket_t
singleipconnect(struct connectdata *conn,
                Curl_addrinfo *ai,
                long timeout_ms,
                bool *connected)
{
  char addr_buf[128];
  int rc;
  int error;
  bool conected;
  struct SessionHandle *data = conn->data;
  curl_socket_t sockfd = socket(ai->ai_family, ai->ai_socktype,
                                ai->ai_protocol);
  if (sockfd == CURL_SOCKET_BAD)
    return CURL_SOCKET_BAD;

  *connected = FALSE; /* default is not connected */

  Curl_printable_address(ai, addr_buf, sizeof(addr_buf));
  infof(data, "  Trying %s... ", addr_buf);

  if(data->set.tcp_nodelay)
    tcpnodelay(conn, sockfd);

#ifdef SO_NOSIGPIPE
  nosigpipe(conn, sockfd);
#endif
  if(conn->data->set.device) {
    /* user selected to bind the outgoing socket to a specified "device"
       before doing connect */
    CURLcode res = bindlocal(conn, sockfd);
    if(res) {
      sclose(sockfd); /* close socket and bail out */
      return CURL_SOCKET_BAD;
    }
  }

  /* set socket non-blocking */
  Curl_nonblock(sockfd, TRUE);

  rc = connect(sockfd, ai->ai_addr, (socklen_t)ai->ai_addrlen);

  if(-1 == rc) {
    error = Curl_ourerrno();

    switch (error) {
    case EINPROGRESS:
    case EWOULDBLOCK:
#if defined(EAGAIN) && EAGAIN != EWOULDBLOCK
      /* On some platforms EAGAIN and EWOULDBLOCK are the
       * same value, and on others they are different, hence
       * the odd #if
       */
    case EAGAIN:
#endif
      rc = waitconnect(sockfd, timeout_ms);
      break;
    default:
      /* unknown error, fallthrough and try another address! */
      failf(data, "Failed to connect to %s: %s",
            addr_buf, Curl_strerror(conn,error));
      data->state.os_errno = error;
      break;
    }
  }

  /* The 'WAITCONN_TIMEOUT == rc' comes from the waitconnect(), and not from
     connect(). We can be sure of this since connect() cannot return 1. */
  if((WAITCONN_TIMEOUT == rc) &&
     (data->state.used_interface == Curl_if_multi)) {
    /* Timeout when running the multi interface */
    return sockfd;
  }

  conected = verifyconnect(sockfd, &error);

  if(!rc && conected) {
    /* we are connected, awesome! */
    *connected = TRUE; /* this is a true connect */
    infof(data, "connected\n");
    return sockfd;
  }
  else if(WAITCONN_TIMEOUT == rc)
    infof(data, "Timeout\n");
  else {
    data->state.os_errno = error;
    infof(data, "%s\n", Curl_strerror(conn, error));
  }

  /* connect failed or timed out */
  sclose(sockfd);

  return CURL_SOCKET_BAD;
}

static CURLcode bindlocal(struct connectdata *conn,
                          curl_socket_t sockfd, int af)
{
  struct SessionHandle *data = conn->data;
  struct sockaddr_in me;
#ifdef ENABLE_IPV6
  struct sockaddr_in6 me6;
#endif
  struct sockaddr *sock = NULL;  /* bind to this address */
  socklen_t socksize = 0; /* size of the data sock points to */
  struct Curl_dns_entry *h=NULL;
  unsigned short port = data->set.localport; /* use this port number, 0 for
                                                "random" */
  /* how many port numbers to try to bind to, increasing one at a time */
  int portnum = data->set.localportrange;
  const char *dev = data->set.str[STRING_DEVICE];
  int error;

  /*************************************************************
   * Select device to bind socket to
   *************************************************************/
  if(dev && (strlen(dev)<255) ) {
    char myhost[256] = "";
    int rc;
    bool was_iface = FALSE;

    if(Curl_if2ip(af, dev, myhost, sizeof(myhost))) {
      /*
       * We now have the numerical IP address in the 'myhost' buffer
       */
      rc = Curl_resolv(conn, myhost, 0, &h);
      if(rc == CURLRESOLV_PENDING)
        (void)Curl_wait_for_resolv(conn, &h);

      if(h) {
        was_iface = TRUE;
      }
    }

    if(!was_iface) {
      /*
       * This was not an interface, resolve the name as a host name
       * or IP number
       */

      /*
       * Temporarily force name resolution to use only the address type
       * of the connection. The resolve functions should really be changed
       * to take a type parameter instead.
       */
      long ipver = data->set.ip_version;
      if (af == AF_INET)
        data->set.ip_version = CURL_IPRESOLVE_V4;
#ifdef ENABLE_IPV6
      else if (af == AF_INET6)
        data->set.ip_version = CURL_IPRESOLVE_V6;
#endif

      rc = Curl_resolv(conn, dev, 0, &h);
      if(rc == CURLRESOLV_PENDING)
        (void)Curl_wait_for_resolv(conn, &h);
      data->set.ip_version = ipver;

      if(h) {
        /* convert the resolved address, sizeof myhost >= INET_ADDRSTRLEN */
        Curl_printable_address(h->addr, myhost, sizeof myhost);
      }
    }

    if(!*myhost || !h) {
      /* need to fix this
         h=Curl_gethost(data,
         getmyhost(*myhost,sizeof(myhost)),
         hostent_buf,
         sizeof(hostent_buf));
      */
      failf(data, "Couldn't bind to '%s'", dev);
      if(h)
        Curl_resolv_unlock(data, h);
      return CURLE_INTERFACE_FAILED;
    }

    infof(data, "Bind local address to %s\n", myhost);

    sock = h->addr->ai_addr;
    socksize = h->addr->ai_addrlen;

#ifdef SO_BINDTODEVICE
    /* I am not sure any other OSs than Linux that provide this feature, and
     * at the least I cannot test. --Ben
     *
     * This feature allows one to tightly bind the local socket to a
     * particular interface.  This will force even requests to other local
     * interfaces to go out the external interface.
     *
     */
    if(was_iface) {
      /* Only bind to the interface when specified as interface, not just as a
       * hostname or ip address.
       */
//.........这里部分代码省略.........

static CURLcode bindlocal(struct connectdata *conn,
                          curl_socket_t sockfd, int af)
{
  struct SessionHandle *data = conn->data;

  struct Curl_sockaddr_storage sa;
  struct sockaddr *sock = (struct sockaddr *)&sa;  /* bind to this address */
  curl_socklen_t sizeof_sa = 0; /* size of the data sock points to */
  struct sockaddr_in *si4 = (struct sockaddr_in *)&sa;
#ifdef ENABLE_IPV6
  struct sockaddr_in6 *si6 = (struct sockaddr_in6 *)&sa;
#endif

  struct Curl_dns_entry *h=NULL;
  unsigned short port = data->set.localport; /* use this port number, 0 for
                                                "random" */
  /* how many port numbers to try to bind to, increasing one at a time */
  int portnum = data->set.localportrange;
  const char *dev = data->set.str[STRING_DEVICE];
  int error;
  char myhost[256] = "";
  int done = 0; /* -1 for error, 1 for address found */
  bool is_interface = FALSE;
  bool is_host = FALSE;
  static const char *if_prefix = "if!";
  static const char *host_prefix = "host!";

  /*************************************************************
   * Select device to bind socket to
   *************************************************************/
  if(!dev && !port)
    /* no local kind of binding was requested */
    return CURLE_OK;

  memset(&sa, 0, sizeof(struct Curl_sockaddr_storage));

  if(dev && (strlen(dev)<255) ) {
    if(strncmp(if_prefix, dev, strlen(if_prefix)) == 0) {
      dev += strlen(if_prefix);
      is_interface = TRUE;
    }
    else if(strncmp(host_prefix, dev, strlen(host_prefix)) == 0) {
      dev += strlen(host_prefix);
      is_host = TRUE;
    }

    /* interface */
    if(!is_host) {
		return CURLE_UNSUPPORTED_PROTOCOL;
    }
    if(!is_interface) {
      /*
       * This was not an interface, resolve the name as a host name
       * or IP number
       *
       * Temporarily force name resolution to use only the address type
       * of the connection. The resolve functions should really be changed
       * to take a type parameter instead.
       */
      long ipver = conn->ip_version;
      int rc;

      if(af == AF_INET)
        conn->ip_version = CURL_IPRESOLVE_V4;
#ifdef ENABLE_IPV6
      else if(af == AF_INET6)
        conn->ip_version = CURL_IPRESOLVE_V6;
#endif

      rc = Curl_resolv(conn, dev, 0, &h);
      if(rc == CURLRESOLV_PENDING)
        (void)Curl_resolver_wait_resolv(conn, &h);
      conn->ip_version = ipver;

      if(h) {
        /* convert the resolved address, sizeof myhost >= INET_ADDRSTRLEN */
        Curl_printable_address(h->addr, myhost, sizeof(myhost));
        infof(data, "Name '%s' family %i resolved to '%s' family %i\n",
              dev, af, myhost, h->addr->ai_family);
        Curl_resolv_unlock(data, h);
        done = 1;
      }
      else {
        /*
         * provided dev was no interface (or interfaces are not supported
         * e.g. solaris) no ip address and no domain we fail here
         */
        done = -1;
      }
    }

    if(done > 0) {
#ifdef ENABLE_IPV6
      /* ipv6 address */
      if(af == AF_INET6) {
#ifdef HAVE_SOCKADDR_IN6_SIN6_SCOPE_ID
        char *scope_ptr = strchr(myhost, '%');
        if(scope_ptr)
          *(scope_ptr++) = 0;
#endif
//.........这里部分代码省略.........

//.........这里部分代码省略.........
           */
          infof(data, "Local Interface %s is ip %s using address family %i\n",
                dev, myhost, af);
          done = 1;
          break;
      }
    }
    if(!is_interface) {
      /*
       * This was not an interface, resolve the name as a host name
       * or IP number
       *
       * Temporarily force name resolution to use only the address type
       * of the connection. The resolve functions should really be changed
       * to take a type parameter instead.
       */
      long ipver = conn->ip_version;
      int rc;

      if(af == AF_INET)
        conn->ip_version = CURL_IPRESOLVE_V4;
#ifdef ENABLE_IPV6
      else if(af == AF_INET6)
        conn->ip_version = CURL_IPRESOLVE_V6;
#endif

      rc = Curl_resolv(conn, dev, 0, &h);
      if(rc == CURLRESOLV_PENDING)
        (void)Curl_resolver_wait_resolv(conn, &h);
      conn->ip_version = ipver;

      if(h) {
        /* convert the resolved address, sizeof myhost >= INET_ADDRSTRLEN */
        Curl_printable_address(h->addr, myhost, sizeof(myhost));
        infof(data, "Name '%s' family %i resolved to '%s' family %i\n",
              dev, af, myhost, h->addr->ai_family);
        Curl_resolv_unlock(data, h);
        done = 1;
      }
      else {
        /*
         * provided dev was no interface (or interfaces are not supported
         * e.g. solaris) no ip address and no domain we fail here
         */
        done = -1;
      }
    }

    if(done > 0) {
#ifdef ENABLE_IPV6
      /* IPv6 address */
      if(af == AF_INET6) {
#ifdef HAVE_SOCKADDR_IN6_SIN6_SCOPE_ID
        char *scope_ptr = strchr(myhost, '%');
        if(scope_ptr)
          *(scope_ptr++) = 0;
#endif
        if(Curl_inet_pton(AF_INET6, myhost, &si6->sin6_addr) > 0) {
          si6->sin6_family = AF_INET6;
          si6->sin6_port = htons(port);
#ifdef HAVE_SOCKADDR_IN6_SIN6_SCOPE_ID
          if(scope_ptr)
            /* The "myhost" string either comes from Curl_if2ip or from
               Curl_printable_address. The latter returns only numeric scope
               IDs and the former returns none at all.  So the scope ID, if
               present, is known to be numeric */