Add SNMP v2c probing and results endpoint.

Probe sysName/sysDescr/sysObjectID for alive hosts, persist SNMP outcomes, and expose scan SNMP data via REST.

Made-with: Cursor

internal/scans/runner.go

@@ -1,6 +1,7 @@
 package scans
 
 import (
+	"fmt"
 	"log"
 	"net"
 	"net/netip"
@@ -9,14 +10,22 @@ import (
 	"strconv"
 	"sync"
 	"time"
+
+	"github.com/gosnmp/gosnmp"
 )
 
 type Runner struct {
 	store Store
+	cfg   RunnerConfig
 }
 
-func NewRunner(store Store) *Runner {
-	return &Runner{store: store}
+type RunnerConfig struct {
+	SNMPEnabled   bool
+	SNMPCommunity string
+}
+
+func NewRunner(store Store, cfg RunnerConfig) *Runner {
+	return &Runner{store: store, cfg: cfg}
 }
 
 func (r *Runner) Start(job ScanJob) {
@@ -87,6 +96,9 @@ func (r *Runner) run(job ScanJob) {
 					})
 				}
 			}
+			if isUp && r.cfg.SNMPEnabled {
+				_ = r.store.SaveSNMPResult(job.ID, probeSNMP(ip, r.cfg.SNMPCommunity, checkedAt, job.Options.PingTimeoutMS))
+			}
 
 			mu.Lock()
 			done++
@@ -125,6 +137,58 @@ func (r *Runner) run(job ScanJob) {
 	})
 }
 
+func probeSNMP(ip, community string, checkedAt time.Time, timeoutMS int) SNMPResult {
+	if timeoutMS <= 0 {
+		timeoutMS = 700
+	}
+	if community == "" {
+		community = "public"
+	}
+
+	client := &gosnmp.GoSNMP{
+		Target:    ip,
+		Port:      161,
+		Version:   gosnmp.Version2c,
+		Community: community,
+		Timeout:   time.Duration(timeoutMS) * time.Millisecond,
+		Retries:   1,
+	}
+	if err := client.Connect(); err != nil {
+		return SNMPResult{IP: ip, Success: false, Error: err.Error(), CheckedAt: checkedAt}
+	}
+	defer client.Conn.Close()
+
+	oids := []string{
+		".1.3.6.1.2.1.1.5.0",
+		".1.3.6.1.2.1.1.1.0",
+		".1.3.6.1.2.1.1.2.0",
+	}
+	pkt, err := client.Get(oids)
+	if err != nil {
+		return SNMPResult{IP: ip, Success: false, Error: err.Error(), CheckedAt: checkedAt}
+	}
+
+	out := SNMPResult{IP: ip, Success: true, CheckedAt: checkedAt}
+	for _, vb := range pkt.Variables {
+		switch vb.Name {
+		case ".1.3.6.1.2.1.1.5.0":
+			out.SysName = snmpValueToString(vb.Value)
+		case ".1.3.6.1.2.1.1.1.0":
+			out.SysDescr = snmpValueToString(vb.Value)
+		case ".1.3.6.1.2.1.1.2.0":
+			out.SysObjectID = snmpValueToString(vb.Value)
+		}
+	}
+	return out
+}
+
+func snmpValueToString(v any) string {
+	if b, ok := v.([]byte); ok {
+		return string(b)
+	}
+	return fmt.Sprint(v)
+}
+
 func expandTargets(cidrs []string, excludeIPs []string) ([]string, error) {
 	excluded := make(map[string]struct{}, len(excludeIPs))
 	for _, ip := range excludeIPs {