IMS Support by anaswarac-dac · Pull Request #317 · omec-project/pcf

anaswarac-dac · 2026-03-23T08:09:59Z

This PR adds IMS call support for UE in PCF.

Note: - During testing with COTS UEs, IMS PDU session release behavior was observed from UE and needs further analysis.

Copilot

Pull request overview

This PR aims to add IMS call support in PCF policy authorization by adjusting how PCC/QoS resources are created/selected for media components and by changing PCC/QoS/TC/packet-filter identifier formats.

Changes:

Switch PCC rule / QoS / TC / packet-filter IDs to plain numeric strings.
Update policy authorization handling to combine MediaSubComponents into a single PCC rule path and send SMF update notifications using a filtered SmPolicyDecision.
Add extensive new logging around AppSessionContext processing and PCC/QoS/TC creation.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 10 comments.

File	Description
util/pcc_rule.go	Changes PCC/QoS/TC/packet-filter identifier formatting to numeric strings.
producer/policyauthorization.go	Adds combined MediaSubComponent handling, filtered SMF notifications, and extensive new logs.
context/ue.go	Modifies SM policy lookup by IPv4 identifiers and adds logging.

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

Copilot · 2026-03-23T22:18:35Z

producer/policyauthorization.go

+		if n, err := strconv.Atoi(id); err == nil && int32(n) > maxID {
+			maxID = int32(n)
+		}


getMaxPccRuleIdNum only considers PCC rule map keys that are pure integers. Before this PR, PCC rule IDs were formatted with a prefix (e.g., PccRuleId-<n>), so after an upgrade existing in-memory decisions may still contain non-numeric keys; those will be ignored here and can cause ID generator collisions. Consider supporting both formats (strip known prefixes before Atoi) or ensuring existing decisions are normalized before calling this.

Suggested change

if n, err := strconv.Atoi(id); err == nil && int32(n) > maxID {

maxID = int32(n)

}

// First, try to parse the ID as a plain integer.

if n, err := strconv.Atoi(id); err == nil {

if int32(n) > maxID {

maxID = int32(n)

}

continue

}

// Fallback: support legacy IDs formatted as "PccRuleId-<n>".

const legacyPrefix = "PccRuleId-"

if strings.HasPrefix(id, legacyPrefix) {

numPart := strings.TrimPrefix(id, legacyPrefix)

if n, err := strconv.Atoi(numPart); err == nil && int32(n) > maxID {

maxID = int32(n)

}

}

Copilot · 2026-03-23T22:18:36Z

context/ue.go

@@ -441,9 +442,12 @@ func (ue *UeContext) SMPolicyFindByIdentifiersIpv4(
 			if sNssai != nil && !reflect.DeepEqual(sNssai, policyContext.SliceInfo) {
 				continue
 			}
-			return smPolicy
 		}
+		logger.CtxLog.Infof("SMPolicy[%s] matched for IPv4: %s", id, v4)
+		return smPolicy


SMPolicyFindByIdentifiersIpv4 returns the first SM policy even when the IPv4 (or other identifiers) do not match, because the log+return are outside the if policyContext.Ipv4Address == v4 block. This will break session binding and can associate requests with the wrong PDU session. Move the log+return inside the matching block (after all identifier checks).

Copilot · 2026-03-23T22:18:36Z

util/pcc_rule.go

 // Get pcc rule Identity(PccRuleId-%d)
 func GetPccRuleId(id int32) string {
-	return fmt.Sprintf("PccRuleId-%d", id)
+	return fmt.Sprintf("%d", id)
 }

 // Get qos Identity(QosId-%d)
 func GetQosId(id int32) string {
-	return fmt.Sprintf("QosId-%d", id)
+	return fmt.Sprintf("%d", id)
 }

 // Get Traffic Control Identity(TcId-%d)
 func GetTcId(id int32) string {
-	return fmt.Sprintf("TcId-%d", id)
+	return fmt.Sprintf("%d", id)


These comments still describe prefixed IDs (e.g., PccRuleId-%d, QosId-%d, TcId-%d) but the functions now return plain numeric strings. Please update the comments so they match the actual ID formats to avoid confusing future callers/debugging.

Copilot · 2026-03-23T22:18:36Z

producer/policyauthorization.go

 			}
-
 			// Find pccRule by AfAppId, otherwise create a new pcc rule
+			logger.PolicyAuthorizationlog.Debugf("AfAppId", appID)


This Debugf call has an extra argument (appID) but the format string has no formatting verb, which will result in %!(EXTRA ...) output in logs and makes troubleshooting harder. Include %s (or similar) in the format string, or remove the unused argument.

Suggested change

logger.PolicyAuthorizationlog.Debugf("AfAppId", appID)

logger.PolicyAuthorizationlog.Debugf("AfAppId: %s", appID)

Copilot · 2026-03-23T22:18:36Z

producer/policyauthorization.go

+			SmPolicyDecision: filteredDecision,
+		}
+		decisionJSON, err := json.MarshalIndent(filteredDecision, "", "  ")


updateSMpolicy can be set due to changes outside PCC/QoS/TC (e.g., PolicyCtrlReqTriggers updates when AF events are subscribed), but the notification sends only filteredDecision (PCC/QoS/TC) to the SMF. This can silently drop trigger updates (and any other updated decision fields). Consider sending smPolicy.PolicyDecision, or extend filteredDecision to include all updated fields (at minimum PolicyCtrlReqTriggers).

Suggested change

SmPolicyDecision: filteredDecision,

}

decisionJSON, err := json.MarshalIndent(filteredDecision, "", " ")

SmPolicyDecision: smPolicy.PolicyDecision,

}

decisionJSON, err := json.MarshalIndent(smPolicy.PolicyDecision, "", " ")

Copilot · 2026-03-23T22:18:37Z

producer/policyauthorization.go

+	logger.PolicyAuthorizationlog.Infof("AppSession Context: %+v", appSessCtx)
+	logger.PolicyAuthorizationlog.Infof("SM Policy associated with AppSession [%s]: %+v", appSessID, smPolicy)


These INFO logs dump entire appSessCtx / smPolicy structs with %+v, which is likely to be extremely large and may include identifiers/policy data that shouldn't be in INFO logs. This also adds avoidable CPU/allocations on every request. Prefer DEBUG level and/or log a small curated summary.

Suggested change

logger.PolicyAuthorizationlog.Infof("AppSession Context: %+v", appSessCtx)

logger.PolicyAuthorizationlog.Infof("SM Policy associated with AppSession [%s]: %+v", appSessID, smPolicy)

logger.PolicyAuthorizationlog.Debugf("AppSession Context: %+v", appSessCtx)

logger.PolicyAuthorizationlog.Debugf("SM Policy associated with AppSession [%s]: %+v", appSessID, smPolicy)

Copilot · 2026-03-23T22:18:37Z

producer/policyauthorization.go

+		if err != nil {
+			logger.PolicyAuthorizationlog.Errorf("Failed to marshal SmPolicyDecision: %+v", err)
+		} else {
+			logger.PolicyAuthorizationlog.Infof("SmPolicyDecision data: %s", string(decisionJSON))


Marshaling and logging the entire SmPolicyDecision as pretty-printed JSON at INFO level can be very expensive and will generate large logs for normal traffic. Consider gating this behind DEBUG (or a feature flag) and logging only identifiers/counts at INFO.

Suggested change

logger.PolicyAuthorizationlog.Infof("SmPolicyDecision data: %s", string(decisionJSON))

logger.PolicyAuthorizationlog.Debugf("SmPolicyDecision data: %s", string(decisionJSON))

Copilot · 2026-03-23T22:18:37Z

util/pcc_rule.go

 // Get Packet Filter Identity(PackFiltId-%d)
 func GetPackFiltId(id int32) string {
-	return fmt.Sprintf("PackFiltId-%d", id)
+	// return fmt.Sprintf("PackFiltId-%d", id)


GetPackFiltId still contains a commented-out return of the old ID format. Keeping dead/commented code here makes the intended format unclear; remove the commented line now that numeric IDs are the chosen format.

Suggested change

// return fmt.Sprintf("PackFiltId-%d", id)

Copilot · 2026-03-23T22:18:37Z

producer/policyauthorization.go

 	ascReqData := appSessCtx.AscReqData
 	pcfSelf := pcf_context.PCF_Self()
-
+	logger.PolicyAuthorizationlog.Infof("Received App Session Context Request: %+v", ascReqData)


Logging the full App Session Context request with %+v at INFO level can leak sensitive UE/session identifiers and can be very verbose in production. Consider lowering this to DEBUG and/or logging only key fields (e.g., Supi/IPs/DNN/MedComp count) after redaction.

Suggested change

logger.PolicyAuthorizationlog.Infof("Received App Session Context Request: %+v", ascReqData)

// Log only key, partially redacted fields to avoid leaking full session context details

supi := ascReqData.Supi

if len(supi) > 5 {

supi = supi[:5] + "..."

}

medCompCount := 0

if ascReqData.MedComponents != nil {

medCompCount = len(ascReqData.MedComponents)

}

logger.PolicyAuthorizationlog.Infof(

"Received App Session Context Request: Supi=%s UeIpv4=%s UeIpv6=%s Dnn=%s MedCompCount=%d",

supi, ascReqData.UeIpv4, ascReqData.UeIpv6, ascReqData.Dnn, medCompCount,

)

Copilot · 2026-03-23T22:18:37Z

producer/policyauthorization.go

+			smPolicy.PackFiltIdGenarator++
+		}
+		pccRule.FlowInfos = flowInfos
+		tcData := util.CreateTcData(smPolicy.PccRuleIdGenarator, "", medSubComps[0].FStatus)


medSubComps[0] is accessed to get FStatus when creating tcData, but medSubComps can be an empty slice (e.g., request contains an empty MedSubComps map). This will panic. Add an explicit length check and return a ProblemDetails error (or derive flow status from medComp / default) when no sub-components are provided.

Suggested change

tcData := util.CreateTcData(smPolicy.PccRuleIdGenarator, "", medSubComps[0].FStatus)

// Derive flow status for TcData; avoid panicking on empty medSubComps slice.

var fStatus models.FlowStatus

if len(medSubComps) > 0 {

fStatus = medSubComps[0].FStatus

} else {

// Fall back to a sensible default when no media sub-components are provided.

fStatus = models.FlowStatus_ENABLED

}

tcData := util.CreateTcData(smPolicy.PccRuleIdGenarator, "", fStatus)

IMS Support

c28d4e9

anaswarac-dac requested a review from a team March 23, 2026 08:09

gab-arrobo requested a review from Copilot March 23, 2026 22:14

Copilot started reviewing on behalf of gab-arrobo March 23, 2026 22:15 View session

Copilot AI reviewed Mar 23, 2026

View reviewed changes

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

IMS Support#317

IMS Support#317
anaswarac-dac wants to merge 1 commit intoomec-project:mainfrom
5GC-DEV:ims-support

anaswarac-dac commented Mar 23, 2026

Uh oh!

Copilot AI left a comment

Uh oh!

Copilot AI Mar 23, 2026

Uh oh!

Copilot AI Mar 23, 2026

Uh oh!

Copilot AI Mar 23, 2026

Uh oh!

Copilot AI Mar 23, 2026

Uh oh!

Copilot AI Mar 23, 2026

Uh oh!

Copilot AI Mar 23, 2026

Uh oh!

Copilot AI Mar 23, 2026

Uh oh!

Copilot AI Mar 23, 2026

Uh oh!

Copilot AI Mar 23, 2026

Uh oh!

Copilot AI Mar 23, 2026

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

2 participants

-		if n, err := strconv.Atoi(id); err == nil && int32(n) > maxID {
-			maxID = int32(n)
-		}
+		// First, try to parse the ID as a plain integer.
+		if n, err := strconv.Atoi(id); err == nil {
+			if int32(n) > maxID {
+				maxID = int32(n)
+			}
+			continue
+		}
+		// Fallback: support legacy IDs formatted as "PccRuleId-<n>".
+		const legacyPrefix = "PccRuleId-"
+		if strings.HasPrefix(id, legacyPrefix) {
+			numPart := strings.TrimPrefix(id, legacyPrefix)
+			if n, err := strconv.Atoi(numPart); err == nil && int32(n) > maxID {
+				maxID = int32(n)
+			}
+		}

	logger.PolicyAuthorizationlog.Debugf("AfAppId", appID)
	logger.PolicyAuthorizationlog.Debugf("AfAppId: %s", appID)

		logger.PolicyAuthorizationlog.Infof("AppSession Context: %+v", appSessCtx)
		logger.PolicyAuthorizationlog.Infof("SM Policy associated with AppSession [%s]: %+v", appSessID, smPolicy)

	logger.PolicyAuthorizationlog.Infof("SmPolicyDecision data: %s", string(decisionJSON))
	logger.PolicyAuthorizationlog.Debugf("SmPolicyDecision data: %s", string(decisionJSON))

-	logger.PolicyAuthorizationlog.Infof("Received App Session Context Request: %+v", ascReqData)
+	// Log only key, partially redacted fields to avoid leaking full session context details
+	supi := ascReqData.Supi
+	if len(supi) > 5 {
+		supi = supi[:5] + "..."
+	}
+	medCompCount := 0
+	if ascReqData.MedComponents != nil {
+		medCompCount = len(ascReqData.MedComponents)
+	}
+	logger.PolicyAuthorizationlog.Infof(
+		"Received App Session Context Request: Supi=%s UeIpv4=%s UeIpv6=%s Dnn=%s MedCompCount=%d",
+		supi, ascReqData.UeIpv4, ascReqData.UeIpv6, ascReqData.Dnn, medCompCount,
+	)

-		tcData := util.CreateTcData(smPolicy.PccRuleIdGenarator, "", medSubComps[0].FStatus)
+		// Derive flow status for TcData; avoid panicking on empty medSubComps slice.
+		var fStatus models.FlowStatus
+		if len(medSubComps) > 0 {
+			fStatus = medSubComps[0].FStatus
+		} else {
+			// Fall back to a sensible default when no media sub-components are provided.
+			fStatus = models.FlowStatus_ENABLED
+		}
+		tcData := util.CreateTcData(smPolicy.PccRuleIdGenarator, "", fStatus)

Conversation

anaswarac-dac commented Mar 23, 2026

Uh oh!

Copilot AI left a comment

Choose a reason for hiding this comment

Pull request overview

Reviewed changes

Uh oh!

Copilot AI Mar 23, 2026

Choose a reason for hiding this comment

Uh oh!

Copilot AI Mar 23, 2026

Choose a reason for hiding this comment

Uh oh!

Copilot AI Mar 23, 2026

Choose a reason for hiding this comment

Uh oh!

Copilot AI Mar 23, 2026

Choose a reason for hiding this comment

Uh oh!

Copilot AI Mar 23, 2026

Choose a reason for hiding this comment

Uh oh!

Copilot AI Mar 23, 2026

Choose a reason for hiding this comment

Uh oh!

Copilot AI Mar 23, 2026

Choose a reason for hiding this comment

Uh oh!

Copilot AI Mar 23, 2026

Choose a reason for hiding this comment

Uh oh!

Copilot AI Mar 23, 2026

Choose a reason for hiding this comment

Uh oh!

Copilot AI Mar 23, 2026

Choose a reason for hiding this comment

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

2 participants