[receiver/snmpreceiver] Add support for SNMP objects of type counter64 (#26119)

Add support for SNMP obecjts of type counter64. The gosnmp library
already has support for this type.
And we already cast all numerical values to an int64.

Author: technimad-splunk

.chloggen/snmpreceiver-add-counter64.yaml

@@ -0,0 +1,27 @@
+# Use this changelog template to create an entry for release notes.
+
+# One of 'breaking', 'deprecation', 'new_component', 'enhancement', 'bug_fix'
+change_type: enhancement
+
+# The name of the component, or a single word describing the area of concern, (e.g. filelogreceiver)
+component: snmpreceiver
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: Add support for SNMP values of type counter64
+
+# Mandatory: One or more tracking issues related to the change. You can use the PR number here if no issue exists.
+issues: [23897]
+
+# (Optional) One or more lines of additional information to render under the primary note.
+# These lines will be padded with 2 spaces and then inserted directly into the document.
+# Use pipe (|) for multiline entries.
+subtext:
+
+# If your change doesn't affect end users or the exported elements of any package,
+# you should instead start your pull request title with [chore] or use the "Skip Changelog" label.
+# Optional: The change log or logs in which this entry should be included.
+# e.g. '[user]' or '[user, api]'
+# Include 'user' if the change is relevant to end users.
+# Include 'api' if there is a change to a library API.
+# Default: '[user]'
+change_logs: [user]

receiver/snmpreceiver/client.go

@@ -326,7 +326,7 @@ func (c *snmpClient) convertSnmpPDUToSnmpData(pdu gosnmp.SnmpPDU) SNMPData {
 	// Condense gosnmp data types to our client's simplified data types
 	switch pdu.Type { // nolint:exhaustive
 	// Integer types
-	case gosnmp.Counter32, gosnmp.Gauge32, gosnmp.Uinteger32, gosnmp.TimeTicks, gosnmp.Integer:
+	case gosnmp.Counter64, gosnmp.Counter32, gosnmp.Gauge32, gosnmp.Uinteger32, gosnmp.TimeTicks, gosnmp.Integer:
 		value, err := c.toInt64(pdu.Name, pdu.Value)
 		if err != nil {
 			clientSNMPData.valueType = notSupportedVal