1 files changed, 189 insertions, 0 deletions
diff --git a/src/go/collectors/go.d.plugin/modules/snmp/init.go b/src/go/collectors/go.d.plugin/modules/snmp/init.go
new file mode 100644
index 000000000..5802d6682
--- /dev/null
+++ b/src/go/collectors/go.d.plugin/modules/snmp/init.go
@@ -0,0 +1,189 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+package snmp
+
+import (
+	"errors"
+	"fmt"
+	"time"
+
+	"github.com/gosnmp/gosnmp"
+)
+
+var newSNMPClient = gosnmp.NewHandler
+
+func (s *SNMP) validateConfig() error {
+	if len(s.ChartsInput) == 0 {
+		return errors.New("'charts' are required but not set")
+	}
+
+	if s.Options.Version == gosnmp.Version3.String() {
+		if s.User.Name == "" {
+			return errors.New("'user.name' is required when using SNMPv3 but not set")
+		}
+		if _, err := parseSNMPv3SecurityLevel(s.User.SecurityLevel); err != nil {
+			return err
+		}
+		if _, err := parseSNMPv3AuthProtocol(s.User.AuthProto); err != nil {
+			return err
+		}
+		if _, err := parseSNMPv3PrivProtocol(s.User.PrivProto); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func (s *SNMP) initSNMPClient() (gosnmp.Handler, error) {
+	client := newSNMPClient()
+
+	if client.SetTarget(s.Hostname); client.Target() == "" {
+		s.Warningf("'hostname' not set, using the default value: '%s'", defaultHostname)
+		client.SetTarget(defaultHostname)
+	}
+	if client.SetPort(uint16(s.Options.Port)); client.Port() <= 0 || client.Port() > 65535 {
+		s.Warningf("'options.port' is invalid, changing to the default value: '%d' => '%d'", s.Options.Port, defaultPort)
+		client.SetPort(defaultPort)
+	}
+	if client.SetRetries(s.Options.Retries); client.Retries() < 1 || client.Retries() > 10 {
+		s.Warningf("'options.retries' is invalid, changing to the default value: '%d' => '%d'", s.Options.Retries, defaultRetries)
+		client.SetRetries(defaultRetries)
+	}
+	if client.SetTimeout(time.Duration(s.Options.Timeout) * time.Second); client.Timeout().Seconds() < 1 {
+		s.Warningf("'options.timeout' is invalid, changing to the default value: '%d' => '%d'", s.Options.Timeout, defaultTimeout)
+		client.SetTimeout(defaultTimeout * time.Second)
+	}
+	if client.SetMaxOids(s.Options.MaxOIDs); client.MaxOids() < 1 {
+		s.Warningf("'options.max_request_size' is invalid, changing to the default value: '%d' => '%d'", s.Options.MaxOIDs, defaultMaxOIDs)
+		client.SetMaxOids(defaultMaxOIDs)
+	}
+
+	ver, err := parseSNMPVersion(s.Options.Version)
+	if err != nil {
+		s.Warningf("'options.version' is invalid, changing to the default value: '%s' => '%s'",
+			s.Options.Version, defaultVersion)
+		ver = defaultVersion
+	}
+	comm := s.Community
+	if comm == "" && (ver <= gosnmp.Version2c) {
+		s.Warningf("'community' not set, using the default value: '%s'", defaultCommunity)
+		comm = defaultCommunity
+	}
+
+	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:
+		client.SetVersion(gosnmp.Version3)
+		client.SetSecurityModel(gosnmp.UserSecurityModel)
+		client.SetMsgFlags(safeParseSNMPv3SecurityLevel(s.User.SecurityLevel))
+		client.SetSecurityParameters(&gosnmp.UsmSecurityParameters{
+			UserName:                 s.User.Name,
+			AuthenticationProtocol:   safeParseSNMPv3AuthProtocol(s.User.AuthProto),
+			AuthenticationPassphrase: s.User.AuthKey,
+			PrivacyProtocol:          safeParseSNMPv3PrivProtocol(s.User.PrivProto),
+			PrivacyPassphrase:        s.User.PrivKey,
+		})
+	default:
+		return nil, fmt.Errorf("invalid SNMP version: %s", s.Options.Version)
+	}
+
+	return client, 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, error) {
+	switch version {
+	case "0", "1":
+		return gosnmp.Version1, nil
+	case "2", "2c", "":
+		return gosnmp.Version2c, nil
+	case "3":
+		return gosnmp.Version3, nil
+	default:
+		return gosnmp.Version2c, fmt.Errorf("invalid snmp version value (%s)", version)
+	}
+}
+
+func safeParseSNMPv3SecurityLevel(level string) gosnmp.SnmpV3MsgFlags {
+	v, _ := parseSNMPv3SecurityLevel(level)
+	return v
+}
+
+func parseSNMPv3SecurityLevel(level string) (gosnmp.SnmpV3MsgFlags, error) {
+	switch level {
+	case "1", "none", "noAuthNoPriv", "":
+		return gosnmp.NoAuthNoPriv, nil
+	case "2", "authNoPriv":
+		return gosnmp.AuthNoPriv, nil
+	case "3", "authPriv":
+		return gosnmp.AuthPriv, nil
+	default:
+		return gosnmp.NoAuthNoPriv, fmt.Errorf("invalid snmpv3 user security level value (%s)", level)
+	}
+}
+
+func safeParseSNMPv3AuthProtocol(protocol string) gosnmp.SnmpV3AuthProtocol {
+	v, _ := parseSNMPv3AuthProtocol(protocol)
+	return v
+}
+
+func parseSNMPv3AuthProtocol(protocol string) (gosnmp.SnmpV3AuthProtocol, error) {
+	switch protocol {
+	case "1", "none", "noAuth", "":
+		return gosnmp.NoAuth, nil
+	case "2", "md5":
+		return gosnmp.MD5, nil
+	case "3", "sha":
+		return gosnmp.SHA, nil
+	case "4", "sha224":
+		return gosnmp.SHA224, nil
+	case "5", "sha256":
+		return gosnmp.SHA256, nil
+	case "6", "sha384":
+		return gosnmp.SHA384, nil
+	case "7", "sha512":
+		return gosnmp.SHA512, nil
+	default:
+		return gosnmp.NoAuth, fmt.Errorf("invalid snmpv3 user auth protocol value (%s)", protocol)
+	}
+}
+
+func safeParseSNMPv3PrivProtocol(protocol string) gosnmp.SnmpV3PrivProtocol {
+	v, _ := parseSNMPv3PrivProtocol(protocol)
+	return v
+}
+
+func parseSNMPv3PrivProtocol(protocol string) (gosnmp.SnmpV3PrivProtocol, error) {
+	switch protocol {
+	case "1", "none", "noPriv", "":
+		return gosnmp.NoPriv, nil
+	case "2", "des":
+		return gosnmp.DES, nil
+	case "3", "aes":
+		return gosnmp.AES, nil
+	case "4", "aes192":
+		return gosnmp.AES192, nil
+	case "5", "aes256":
+		return gosnmp.AES256, nil
+	case "6", "aes192c":
+		return gosnmp.AES192C, nil
+	case "7", "aes256c":
+		return gosnmp.AES256C, nil
+	default:
+		return gosnmp.NoPriv, fmt.Errorf("invalid snmpv3 user priv protocol value (%s)", protocol)
+	}
+}