Files
fscan/plugins/services/dns.go
T
ZacharyZcR 04cae2e42d fix: 彻底解决UDP插件阻塞导致扫描无法结束的问题
根因分析(通过 goroutine dump 定位):
1. UDP conn.Write 在 WSL2 上可能永久阻塞(SetDeadline 对 Write 不生效)
2. SNMP community 爆破混入通用密码字典(57个),串行 × 10s超时 = 10分钟

修复:
- 提取 udpProbe() 公共函数,用 context timeout + conn.Close 双保险
  超时后强制关闭连接,中断阻塞的 Write/Read
- BACnet/DNS/IPMI/TFTP 统一使用 udpProbe()
- SNMP probe 使用 goroutine + context select 保护
- SNMP community 列表不再混入通用密码字典(8个专用 community 足够)
- SNMP 后续 community 爆破用 3s 短超时 + 连续失败 3 次快速退出

效果: 同样的扫描从无限卡死 → 9秒完成
2026-06-14 22:23:50 +08:00

54 lines
1.1 KiB
Go

//go:build plugin_dns || !plugin_selective
package services
import (
"context"
"time"
"github.com/shadow1ng/fscan/common"
"github.com/shadow1ng/fscan/plugins"
)
type DNSPlugin struct {
plugins.BasePlugin
}
func NewDNSPlugin() *DNSPlugin {
return &DNSPlugin{BasePlugin: plugins.NewBasePlugin("dns")}
}
func (p *DNSPlugin) Scan(ctx context.Context, info *common.HostInfo, session *common.ScanSession) *ScanResult {
timeout := session.Config.Timeout
if timeout <= 0 {
timeout = 3 * time.Second
}
target := info.Target()
queryID := randomUint16()
query := buildDNSRootNSQuery(queryID)
data, n := udpProbe(ctx, session, target, timeout, query, 1500)
if data == nil || n < 12 {
return &ScanResult{Success: false, Service: "dns"}
}
banner, ok := parseDNSResponse(data[:n], queryID)
if !ok {
return &ScanResult{Success: false, Service: "dns"}
}
return &ScanResult{
Success: true,
Type: plugins.ResultTypeService,
Service: "dns",
Banner: banner,
}
}
func init() {
RegisterUDPPluginWithPorts("dns", func() Plugin {
return NewDNSPlugin()
}, []int{53})
}