shadow1ng/fscan · error

connection lost and reconnect failed

Error message

connection lost and reconnect failed

What it means

Guard error returned by Info.Write and Info.Read in the service probe layer when the underlying net.Conn is nil, i.e. the TLS/connection was lost and a reconnect either never happened or failed. It aborts further I/O on a dead connection rather than nil-dereferencing.

Source

Thrown at core/service_probe.go:24

	"io"
	"net"
	"strconv"
	"strings"
	"sync"
	"time"

	"github.com/shadow1ng/fscan/common"
	"github.com/shadow1ng/fscan/common/i18n"
	"github.com/shadow1ng/fscan/core/portfinger"
)

// 默认超时时间常量
const (
	defaultTotalWaitMS = 3000 // 服务探测默认等待时间
	defaultIntensity   = 7    // 默认探测强度 (1-9)
)

var errConnLost = errors.New("connection lost and reconnect failed")

// sslSecondProbes SSL服务二次探测的探针名称
var sslSecondProbes = []string{"TerminalServerCookie", "TerminalServer"}

// Probe PortFinger探测器类型别名 - 简化引用
type (
	Probe = portfinger.Probe
	// Match PortFinger匹配规则类型别名
	Match = portfinger.Match
)

// PortFinger全局访问 - 简化探测器访问
var (
	v           = portfinger.GetGlobalVScan()
	null        = portfinger.GetNullProbe()
	commonProbe = portfinger.GetCommonProbe()
	DecodeData  = portfinger.DecodeData
)

View on GitHub (pinned to 95cc12e753)

Solutions

1. Re-establish the connection (re-run the probe dial) before retrying reads/writes
2. Treat as non-fatal: drop this probe attempt and let the scanner move to the next target
3. Inspect why the connection dropped: network flakiness, RST from an IDS, or probe timeout

When it happens

Trigger: Thrown at core/service_probe.go:24 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of shadow1ng/fscan@95cc12e753 (2026-09-06). Data as JSON: /api/errors/0b3aa3a0d72eff0a. Report an issue: GitHub.