return c(ctx, network, address)
}

const (
	defaultOutQueue    = 65535    // kind of close to max open fds per user
	readBufferSize     = 32 << 10 // 32 KiB is the most optimal on Linux
	writeBufferSize    = 32 << 10 // 32 KiB is the most optimal on Linux
	defaultDialTimeout = 2 * time.Second
	connPingInterval   = 10 * time.Second
	connWriteTimeout   = 3 * time.Second
)

type connectionParams struct {

func isHostIP(ipAddress string) bool {
	host, _, err := net.SplitHostPort(ipAddress)
	if err != nil {
		host = ipAddress
	}
	// Strip off IPv6 zone information.
	if i := strings.Index(host, "%"); i > -1 {
		host = host[:i]
	}
	return net.ParseIP(host) != nil
}

// extractHostPort - extracts host/port from many address formats

				}
			}
		}
		// loop through buckets and see if some with lost quorum
		// these could be stale buckets lying around, queue a heal
		// of such a bucket. This is needed here as we identify such
		// buckets here while listing buckets. As part of regular
		// globalBucketMetadataSys.Init() call would get a valid
		// buckets only and not the quourum lost ones like this, so
		// explicit call

	hosts := make([]string, len(records))
	for i, r := range records {
		hosts[i] = net.JoinHostPort(r.Host, string(r.Port))
	}
	return hosts
}

// returns an online host (and corresponding port) from a slice of DNS records
func getHostFromSrv(records []dns.SrvRecord) (host string) {
	hosts := getHostsSlice(records)
	rng := rand.New(rand.NewSource(time.Now().UTC().UnixNano()))
	var d net.Dialer

// in front of MinIO.
func checkRemoteEndpoint(ctx context.Context, epURL *url.URL) error {
	reqURL := &url.URL{
		Scheme: epURL.Scheme,
		Host:   epURL.Host,
		Path:   healthCheckPathPrefix + healthCheckReadinessPath,
	}

	req, err := http.NewRequestWithContext(ctx, http.MethodGet, reqURL.String(), nil)
	if err != nil {
		return err
	}

				"X-Amz-SignedHeaders":  "host;x-amz-content-sha256;x-amz-date",
				"X-Amz-Credential":     fmt.Sprintf(credentialTemplate, accessKeyID, now.Format(yyyymmdd), "us-west-1"),
				"X-Amz-Content-Sha256": payloadSHA256,
			},
			region:   "us-west-1",
			expected: ErrUnsignedHeaders,
		},
		// (3) Should fail to extract headers if the host header is not signed.
		{
			queryParams: map[string]string{

	return func(ctx context.Context, network, addr string) (conn net.Conn, err error) {
		host, port, err := net.SplitHostPort(addr)
		if err != nil {
			return nil, err
		}

		if net.ParseIP(host) != nil {
			// For IP only setups there is no need for DNS lookups.
			return baseDialCtx(ctx, "tcp", addr)
		}

		ips, err := lookupHost(ctx, host)
		if err != nil {
			return nil, err
		}

		for _, ip := range ips {

			req: &http.Request{
				URL: &url.URL{
					Host:     "127.0.0.1:9000",
					Scheme:   httpScheme,
					Path:     SlashSeparator,
					RawQuery: "X-Amz-Credential=EXAMPLEINVALIDEXAMPL%2Fs3%2F20160314%2Fus-east-1",
				},
			},
			authT: authTypePresigned,
		},
		// Test case - 5
		// Check for post policy.
		{
			req: &http.Request{
				URL: &url.URL{
					Host:   "127.0.0.1:9000",
					Scheme: httpScheme,

		for k, v := range reqHeaders {
			inputBytes += len(k) + len(v)
		}

		// Calculate node name
		nodeName := r.Host
		if globalIsDistErasure {
			nodeName = globalLocalNodeName
		}
		if host, port, err := net.SplitHostPort(nodeName); err == nil {
			if port == "443" || port == "80" {
				nodeName = host
			}
		}

		// Calculate reqPath
		reqPath := r.URL.RawPath
		if reqPath == "" {

package http

import (
	"context"
	"net"
	"syscall"
	"time"
)

// CheckPortAvailability - check if given host and port is already in use.
// Note: The check method tries to listen on given port and closes it.
// It is possible to have a disconnected client in this tiny window of time.
func CheckPortAvailability(host, port string, opts TCPOptions) (err error) {
	lc := &net.ListenConfig{