refactor: packet module (split to parse/build/layer/tunnel/utils)

src/packet/packet_layer.cpp

@@ -1,6 +1,12 @@
-#include "packet_priv.h"
+#include "packet_def.h"
+#include "packet_layer.h"
 #include "packet_utils.h"
 
+int packet_get_layer_count(const struct packet *pkt)
+{
+    return pkt->layers_used;
+}
+
 int packet_get_layer_by_idx(const struct packet *pkt, int idx, struct layer *out)
 {
     const struct raw_layer *raw = packet_get_raw_layer(pkt, idx);
@@ -14,3 +20,44 @@ int packet_get_layer_by_idx(const struct packet *pkt, int idx, struct layer *out
         return 0;
     }
 }
+
+const struct raw_layer *packet_get_raw_layer(const struct packet *pkt, int idx)
+{
+    if (idx < 0 || idx >= pkt->layers_used)
+    {
+        return NULL;
+    }
+    return &pkt->layers[idx];
+}
+
+const struct raw_layer *packet_get_innermost_raw_layer(const struct packet *pkt, enum layer_proto proto)
+{
+    const struct raw_layer *layer = NULL;
+
+    for (int8_t i = pkt->layers_used - 1; i >= 0; i--)
+    {
+        layer = &pkt->layers[i];
+        if (layer->proto == proto)
+        {
+            return layer;
+        }
+    }
+
+    return NULL;
+}
+
+const struct raw_layer *packet_get_outermost_raw_layer(const struct packet *pkt, enum layer_proto proto)
+{
+    const struct raw_layer *layer = NULL;
+
+    for (int8_t i = 0; i < pkt->layers_used; i++)
+    {
+        layer = &pkt->layers[i];
+        if (layer->proto == proto)
+        {
+            return layer;
+        }
+    }
+
+    return NULL;
+}