refactor: move struct laye and struct tunnel to packet.h

include/stellar/packet.h

@@ -6,6 +6,150 @@ extern "C"
 #endif
 
 #include <stdint.h>
+#define __FAVOR_BSD 1
+#include <netinet/tcp.h>
+#include <netinet/udp.h>
+#include <netinet/ip.h>
+#include <netinet/ip6.h>
+#include <netinet/icmp6.h>
+#include <netinet/ip_icmp.h>
+#include <linux/if_ether.h>
+#include <linux/mpls.h>
+
+/******************************************************************************
+ * layer
+ ******************************************************************************/
+
+enum layer_proto
+{
+    LAYER_PROTO_NONE = 0,
+
+    // L2 -- data link layer
+    LAYER_PROTO_ETHER = 1,
+    LAYER_PROTO_PWETH = 2,
+    LAYER_PROTO_PPP = 3,
+    LAYER_PROTO_L2TP = 4,
+
+    // L2 -- tunnel
+    LAYER_PROTO_VLAN = 21,
+    LAYER_PROTO_PPPOE = 22,
+    LAYER_PROTO_MPLS = 23,
+
+    // L3 -- network layer
+    LAYER_PROTO_IPV4 = 31,
+    LAYER_PROTO_IPV6 = 32,
+    LAYER_PROTO_IPAH = 33,
+
+    // L3 -- tunnel
+    LAYER_PROTO_GRE = 41,
+
+    // L4 -- transport layer
+    LAYER_PROTO_UDP = 51,
+    LAYER_PROTO_TCP = 52,
+    LAYER_PROTO_ICMP = 53,
+    LAYER_PROTO_ICMP6 = 54,
+
+    // L4 -- tunnel
+    LAYER_PROTO_VXLAN = 61,
+    LAYER_PROTO_GTP_U = 62,
+    LAYER_PROTO_GTP_C = 63,
+};
+
+struct layer
+{
+    enum layer_proto proto;
+    uint16_t hdr_len;
+    union
+    {
+        // all hdr ptr refer to raw packet, read-only
+        const struct ethhdr *eth;
+        const struct ip *ip4;
+        const struct ip6_hdr *ip6;
+        const struct tcphdr *tcp;
+        const struct udphdr *udp;
+        const struct icmphdr *icmp4;
+        const struct icmp6_hdr *icmp6;
+        const struct mpls_label *mpls;
+        const char *raw; // e.g. pppoe, l2tp, gre, gtp, etc.
+    } hdr;
+};
+
+int packet_get_layer_count(const struct packet *pkt);
+const struct layer *packet_get_layer_by_idx(const struct packet *pkt, int idx);
+
+//  // example: foreach layer in packet (inorder)
+//  int count = packet_get_layer_count(pkt);
+//  for (int i = 0; i < count; i++)
+//  {
+//      const struct layer *layer = packet_get_layer_by_idx(pkt, i);
+//      // do something with layer
+//  }
+//
+//
+//  // example: foreach layer in packet (reverse)
+//  int count = packet_get_layer_count(pkt);
+//  for (int i = count - 1; i >= 0; i--)
+//  {
+//      const struct layer *layer = packet_get_layer_by_idx(pkt, i);
+//      // do something with layer
+//  }
+
+/******************************************************************************
+ * tunnel
+ ******************************************************************************/
+
+enum tunnel_type
+{
+    TUNNEL_IPV4 = 1, // contain layers: IPv4, (next inner layer must be IPv4 / IPv6)
+    TUNNEL_IPV6 = 2, // contain layers: IPv6, (next inner layer must be IPv4 / IPv6)
+
+    TUNNEL_GRE = 3, // contain layers: IPv4 + GRE
+                    // contain layers: IPv6 + GRE
+
+    TUNNEL_GTP = 4, // contain layers: IPv4 + UDP + GTP
+                    // contain layers: IPv6 + UDP + GTP
+
+    TUNNEL_VXLAN = 5, // contain layers: IPv4 + UDP + VXLAN
+                      // contain layers: IPv6 + UDP + VXLAN
+
+    TUNNEL_L2TP = 6, // contain layers: IPv4 + UDP + L2TP
+                     // contain layers: IPv6 + UDP + L2TP
+
+    TUNNEL_TEREDO = 7, // contain layers: IPv4 + UDP, (next inner layer must be IPv6)
+};
+
+#define MAX_LAYERS_PER_TUNNEL 3
+struct tunnel
+{
+    enum tunnel_type type;
+
+    int layer_count;
+    const struct layer *layers[MAX_LAYERS_PER_TUNNEL];
+};
+
+int packet_get_tunnel_count(const struct packet *pkt);
+// return  0: success 
+// return -1: failed
+int packet_get_tunnel_by_idx(const struct packet *pkt, int idx, struct tunnel *out);
+
+/******************************************************************************
+ * build
+ ******************************************************************************/
+
+/*
+ * tcp_seq: the sequence number of the new TCP packet (in host byte order)
+ * tcp_ack: the acknowledgment number of the new TCP packet (in host byte order)
+ * tcp_options_len: the length of the options (must be a multiple of 4)
+ */
+struct packet *packet_build_tcp(const struct packet *origin_pkt, uint32_t tcp_seq, uint32_t tcp_ack, uint8_t tcp_flags,
+                                const char *tcp_options, uint16_t tcp_options_len,
+                                const char *tcp_payload, uint16_t tcp_payload_len);
+struct packet *packet_build_udp(const struct packet *origin_pkt, const char *udp_payload, uint16_t udp_payload_len);
+struct packet *packet_build_l3(const struct packet *origin_pkt, uint8_t ip_proto, const char *l3_payload, uint16_t l3_payload_len);
+
+/******************************************************************************
+ * utils
+ ******************************************************************************/
 
 #define MAX_SIDS 8
 struct sids
@@ -36,17 +180,6 @@ uint16_t packet_get_raw_len(const struct packet *pkt);
 const char *packet_get_payload(const struct packet *pkt);
 uint16_t packet_get_payload_len(const struct packet *pkt);
 
-/*
- * tcp_seq: the sequence number of the new TCP packet (in host byte order)
- * tcp_ack: the acknowledgment number of the new TCP packet (in host byte order)
- * tcp_options_len: the length of the options (must be a multiple of 4)
- */
-struct packet *packet_build_tcp(const struct packet *origin_pkt, uint32_t tcp_seq, uint32_t tcp_ack, uint8_t tcp_flags,
-                                const char *tcp_options, uint16_t tcp_options_len,
-                                const char *tcp_payload, uint16_t tcp_payload_len);
-struct packet *packet_build_udp(const struct packet *origin_pkt, const char *udp_payload, uint16_t udp_payload_len);
-struct packet *packet_build_l3(const struct packet *origin_pkt, uint8_t ip_proto, const char *l3_payload, uint16_t l3_payload_len);
-
 #ifdef __cplusplus
 }
 #endif