Allow sampling configs to be applied for PCA

Signed-off-by: Mohamed Mahmoud <mmahmoud@redhat.com>
netobserv · Jun 28, 2024 · e318d16 · e318d16
1 parent e84e169
commit e318d16
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Showing 7 changed files with 7 additions and 0 deletions.
diff --git a/bpf/pca.h b/bpf/pca.h
@@ -66,6 +66,11 @@ static inline bool validate_pca_filter(struct __sk_buff *skb, direction dir) {
 }
 
 static inline int export_packet_payload(struct __sk_buff *skb, direction dir) {
+    // If sampling is defined, will only parse 1 out of "sampling" flows
+    if (sampling > 1 && (bpf_get_prandom_u32() % sampling) != 0) {
+        return 0;
+    }
+
     void *data_end = (void *)(long)skb->data_end;
     void *data = (void *)(long)skb->data;
 

diff --git a/pkg/agent/packets_agent.go b/pkg/agent/packets_agent.go
@@ -77,6 +77,7 @@ func PacketsAgent(cfg *Config) (*Packets, error) {
 		EnableIngress: ingress,
 		EnableEgress:  egress,
 		Debug:         debug,
+		Sampling:      cfg.Sampling,
 		CacheMaxSize:  cfg.CacheMaxFlows,
 		EnablePCA:     cfg.EnablePCA,
 		FilterConfig: &ebpf.FilterConfig{

diff --git a/pkg/ebpf/bpf_arm64_bpfel.o b/pkg/ebpf/bpf_arm64_bpfel.o
diff --git a/pkg/ebpf/bpf_powerpc_bpfel.o b/pkg/ebpf/bpf_powerpc_bpfel.o
diff --git a/pkg/ebpf/bpf_s390_bpfeb.o b/pkg/ebpf/bpf_s390_bpfeb.o
diff --git a/pkg/ebpf/bpf_x86_bpfel.o b/pkg/ebpf/bpf_x86_bpfel.o
diff --git a/pkg/ebpf/tracer.go b/pkg/ebpf/tracer.go
@@ -726,6 +726,7 @@ func NewPacketFetcher(cfg *FlowFetcherConfig) (*PacketFetcher, error) {
 	}
 
 	if err := spec.RewriteConstants(map[string]interface{}{
+		constSampling:  uint32(cfg.Sampling),
 		constPcaEnable: uint8(pcaEnable),
 	}); err != nil {
 		return nil, fmt.Errorf("rewriting BPF constants definition: %w", err)