Support struct tunnel

src/packet/CMakeLists.txt

@@ -1,4 +1,4 @@
-add_library(packet packet.cpp packet_utils.cpp packet_layer.cpp)
+add_library(packet packet.cpp packet_utils.cpp packet_layer.cpp packet_tunnel.cpp)
 target_include_directories(packet PUBLIC ${CMAKE_CURRENT_LIST_DIR})
 target_include_directories(packet PUBLIC ${CMAKE_SOURCE_DIR}/deps/uthash)
 target_include_directories(packet PUBLIC ${CMAKE_SOURCE_DIR}/include)

src/packet/packet_layer.cpp

@@ -1,23 +1,16 @@
 #include "packet_priv.h"
+#include "packet_utils.h"
 
 int packet_get_layer(const struct packet *pkt, int idx, struct layer *out)
 {
-    if (pkt == NULL || out == NULL)
+    const struct raw_layer *raw = packet_get_raw_layer(pkt, idx);
+    if (raw == NULL)
     {
         return -1;
     }
-
-    if (idx < 0 || idx >= pkt->layers_used)
+    else
     {
-        return -1;
+        layer_convert(raw, out);
+        return 0;
     }
-
-    const struct raw_layer *raw = &pkt->layers[idx];
-    out->proto = raw->proto;
-    out->header_len = raw->hdr_len;
-    out->payload_len = raw->pld_len;
-    out->header.raw = raw->hdr_ptr;
-    out->payload = raw->pld_ptr;
-
-    return 0;
 }

src/packet/packet_tunnel.cpp

@@ -0,0 +1,99 @@
+#include <assert.h>
+
+#include "stellar/tunnel.h"
+#include "packet_priv.h"
+#include "packet_utils.h"
+
+static void layers_to_tunnel(const struct raw_layer *curr, const struct raw_layer *next1, const struct raw_layer *next2, struct tunnel *out)
+{
+    assert(curr);
+
+    // GRE tunnel
+    if (next1 && next1->proto == LAYER_PROTO_GRE)
+    {
+        out->type = TUNNEL_GRE;
+        out->used = 2;
+        layer_convert(curr, &out->layers[0]);
+        layer_convert(next1, &out->layers[1]);
+        return;
+    }
+
+    // GTP tunnel
+    if (next1 && next1->proto == LAYER_PROTO_UDP && next2 && next2->proto == LAYER_PROTO_GTPV1_U)
+    {
+        out->type = TUNNEL_GTP;
+        out->used = 3;
+        layer_convert(curr, &out->layers[0]);
+        layer_convert(next1, &out->layers[1]);
+        layer_convert(next2, &out->layers[2]);
+        return;
+    }
+
+    // IP tunnel
+    if (next1 && (next1->proto == LAYER_PROTO_IPV4 || next1->proto == LAYER_PROTO_IPV6))
+    {
+        out->type = curr->proto == LAYER_PROTO_IPV4 ? TUNNEL_IPV4 : TUNNEL_IPV6;
+        out->used = 1;
+        layer_convert(curr, &out->layers[0]);
+        return;
+    }
+
+    // none tunnel
+    out->type = TUNNEL_NONE;
+    layer_convert(curr, &out->layers[out->used++]);
+    if (next1 && (next1->proto == LAYER_PROTO_TCP || next1->proto == LAYER_PROTO_UDP))
+    {
+        layer_convert(next1, &out->layers[out->used++]);
+    }
+    return;
+}
+
+int packet_get_tunnel_count(const struct packet *pkt)
+{
+    int count = 0;
+    int used = packet_get_layer_count(pkt);
+    const struct raw_layer *curr = NULL;
+
+    for (int i = 0; i < used; i++)
+    {
+        curr = packet_get_raw_layer(pkt, i);
+        if (curr->proto == LAYER_PROTO_IPV4 || curr->proto == LAYER_PROTO_IPV6)
+        {
+            count++;
+        }
+    }
+
+    return count;
+}
+
+// return  0: success 
+// return -1: failed
+int packet_get_tunnel(const struct packet *pkt, int idx, struct tunnel *out)
+{
+    int count = 0;
+    int used = packet_get_layer_count(pkt);
+    const struct raw_layer *curr = NULL;
+    const struct raw_layer *next1 = NULL;
+    const struct raw_layer *next2 = NULL;
+    memset(out, 0, sizeof(struct tunnel));
+
+    for (int i = 0; i < used; i++)
+    {
+        curr = packet_get_raw_layer(pkt, i);
+        next1 = packet_get_raw_layer(pkt, i + 1);
+        next2 = packet_get_raw_layer(pkt, i + 2);
+
+        if (curr->proto == LAYER_PROTO_IPV4 || curr->proto == LAYER_PROTO_IPV6)
+        {
+            if (count == idx)
+            {
+                layers_to_tunnel(curr, next1, next2, out);
+                return 0;
+            }
+
+            count++;
+        }
+    }
+
+    return -1;
+}

src/packet/packet_utils.cpp

@@ -186,4 +186,18 @@ void packet_free(struct packet *pkt)
     {
         free((void *)pkt);
     }
+}
+
+void layer_convert(const struct raw_layer *in, struct layer *out)
+{
+    if (in == NULL || out == NULL)
+    {
+        return;
+    }
+
+    out->proto = in->proto;
+    out->header_len = in->hdr_len;
+    out->payload_len = in->pld_len;
+    out->header.raw = in->hdr_ptr;
+    out->payload = in->pld_ptr;
 }

src/packet/packet_utils.h

@@ -50,6 +50,8 @@ struct packet *packet_new(uint16_t pkt_len);
 struct packet *packet_dup(const struct packet *pkt);
 void packet_free(struct packet *pkt);
 
+void layer_convert(const struct raw_layer *in, struct layer *out);
+
 #ifdef __cplusplus
 }
 #endif