1 files changed, 175 insertions, 0 deletions
diff --git a/src/go/plugin/go.d/modules/snmp/init.go b/src/go/plugin/go.d/modules/snmp/init.go
new file mode 100644
index 000000000..acde4b9b8
--- /dev/null
+++ b/src/go/plugin/go.d/modules/snmp/init.go
@@ -0,0 +1,175 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+package snmp
+
+import (
+	"errors"
+	"fmt"
+	"strings"
+	"time"
+
+	"github.com/netdata/netdata/go/plugins/plugin/go.d/pkg/matcher"
+
+	"github.com/gosnmp/gosnmp"
+)
+
+func (s *SNMP) validateConfig() error {
+	if s.Hostname == "" {
+		return errors.New("SNMP hostname is required")
+	}
+	return nil
+}
+
+func (s *SNMP) initSNMPClient() (gosnmp.Handler, error) {
+	client := s.newSnmpClient()
+
+	client.SetTarget(s.Hostname)
+	client.SetPort(uint16(s.Options.Port))
+	client.SetRetries(s.Options.Retries)
+	client.SetTimeout(time.Duration(s.Options.Timeout) * time.Second)
+	client.SetMaxOids(s.Options.MaxOIDs)
+	client.SetMaxRepetitions(uint32(s.Options.MaxRepetitions))
+
+	ver := parseSNMPVersion(s.Options.Version)
+	comm := s.Community
+
+	switch ver {
+	case gosnmp.Version1:
+		client.SetCommunity(comm)
+		client.SetVersion(gosnmp.Version1)
+	case gosnmp.Version2c:
+		client.SetCommunity(comm)
+		client.SetVersion(gosnmp.Version2c)
+	case gosnmp.Version3:
+		if s.User.Name == "" {
+			return nil, errors.New("username is required for SNMPv3")
+		}
+		client.SetVersion(gosnmp.Version3)
+		client.SetSecurityModel(gosnmp.UserSecurityModel)
+		client.SetMsgFlags(parseSNMPv3SecurityLevel(s.User.SecurityLevel))
+		client.SetSecurityParameters(&gosnmp.UsmSecurityParameters{
+			UserName:                 s.User.Name,
+			AuthenticationProtocol:   parseSNMPv3AuthProtocol(s.User.AuthProto),
+			AuthenticationPassphrase: s.User.AuthKey,
+			PrivacyProtocol:          parseSNMPv3PrivProtocol(s.User.PrivProto),
+			PrivacyPassphrase:        s.User.PrivKey,
+		})
+	default:
+		return nil, fmt.Errorf("invalid SNMP version: %s", s.Options.Version)
+	}
+
+	s.Info(snmpClientConnInfo(client))
+
+	return client, nil
+}
+
+func (s *SNMP) initNetIfaceFilters() (matcher.Matcher, matcher.Matcher, error) {
+	byName, byType := matcher.FALSE(), matcher.FALSE()
+
+	if v := s.NetworkInterfaceFilter.ByName; v != "" {
+		m, err := matcher.NewSimplePatternsMatcher(v)
+		if err != nil {
+			return nil, nil, err
+		}
+		byName = m
+	}
+
+	if v := s.NetworkInterfaceFilter.ByType; v != "" {
+		m, err := matcher.NewSimplePatternsMatcher(v)
+		if err != nil {
+			return nil, nil, err
+		}
+		byType = m
+	}
+
+	return byName, byType, nil
+}
+
+func (s *SNMP) initOIDs() (oids []string) {
+	for _, c := range *s.charts {
+		for _, d := range c.Dims {
+			oids = append(oids, d.ID)
+		}
+	}
+	return oids
+}
+
+func parseSNMPVersion(version string) gosnmp.SnmpVersion {
+	switch version {
+	case "0", "1":
+		return gosnmp.Version1
+	case "2", "2c", "":
+		return gosnmp.Version2c
+	case "3":
+		return gosnmp.Version3
+	default:
+		return gosnmp.Version2c
+	}
+}
+
+func parseSNMPv3SecurityLevel(level string) gosnmp.SnmpV3MsgFlags {
+	switch level {
+	case "1", "none", "noAuthNoPriv", "":
+		return gosnmp.NoAuthNoPriv
+	case "2", "authNoPriv":
+		return gosnmp.AuthNoPriv
+	case "3", "authPriv":
+		return gosnmp.AuthPriv
+	default:
+		return gosnmp.NoAuthNoPriv
+	}
+}
+
+func parseSNMPv3AuthProtocol(protocol string) gosnmp.SnmpV3AuthProtocol {
+	switch protocol {
+	case "1", "none", "noAuth", "":
+		return gosnmp.NoAuth
+	case "2", "md5":
+		return gosnmp.MD5
+	case "3", "sha":
+		return gosnmp.SHA
+	case "4", "sha224":
+		return gosnmp.SHA224
+	case "5", "sha256":
+		return gosnmp.SHA256
+	case "6", "sha384":
+		return gosnmp.SHA384
+	case "7", "sha512":
+		return gosnmp.SHA512
+	default:
+		return gosnmp.NoAuth
+	}
+}
+
+func parseSNMPv3PrivProtocol(protocol string) gosnmp.SnmpV3PrivProtocol {
+	switch protocol {
+	case "1", "none", "noPriv", "":
+		return gosnmp.NoPriv
+	case "2", "des":
+		return gosnmp.DES
+	case "3", "aes":
+		return gosnmp.AES
+	case "4", "aes192":
+		return gosnmp.AES192
+	case "5", "aes256":
+		return gosnmp.AES256
+	case "6", "aes192c":
+		return gosnmp.AES192C
+	case "7", "aes256c":
+		return gosnmp.AES256C
+	default:
+		return gosnmp.NoPriv
+	}
+}
+
+func snmpClientConnInfo(c gosnmp.Handler) string {
+	var info strings.Builder
+	info.WriteString(fmt.Sprintf("hostname='%s',port='%d',snmp_version='%s'", c.Target(), c.Port(), c.Version()))
+	switch c.Version() {
+	case gosnmp.Version1, gosnmp.Version2c:
+		info.WriteString(fmt.Sprintf(",community='%s'", c.Community()))
+	case gosnmp.Version3:
+		info.WriteString(fmt.Sprintf(",security_level='%d,%s'", c.MsgFlags(), c.SecurityParameters().Description()))
+	}
+	return info.String()
+}