Refactored packet API to support struct layer (using union to contain different types of encapsulation headers)

5 files changed, 116 insertions, 151 deletions

diff --git a/include/CMakeLists.txt b/include/CMakeLists.txt
index 91b7269..e231241 100644
--- a/include/CMakeLists.txt
+++ b/include/CMakeLists.txt
@@ -1,4 +1,5 @@
 install(FILES stellar/utils.h DESTINATION include/stellar/ COMPONENT LIBRARIES)
+install(FILES stellar/layer.h DESTINATION include/stellar/ COMPONENT LIBRARIES)
 install(FILES stellar/packet.h DESTINATION include/stellar/ COMPONENT LIBRARIES)
 install(FILES stellar/session.h DESTINATION include/stellar/ COMPONENT LIBRARIES)
 install(FILES stellar/stellar.h DESTINATION include/stellar/ COMPONENT LIBRARIES)
diff --git a/include/stellar/layer.h b/include/stellar/layer.h
new file mode 100644
index 0000000..fce1315
--- /dev/null
+++ b/include/stellar/layer.h
@@ -0,0 +1,99 @@
+#ifndef _LAYER_H
+#define _LAYER_H
+
+#ifdef __cplusplus
+extern "C"
+{
+#endif
+
+#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>
+
+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_GTPV1_U = 62,
+};
+
+struct layer
+{
+    enum layer_proto proto;
+    uint16_t payload_len;
+    uint16_t header_len;
+    union
+    {
+        struct ethhdr *eth;
+        struct ip *ip4;
+        struct ip6_hdr *ip6;
+        struct tcphdr *tcp;
+        struct udphdr *udp;
+        struct icmphdr *icmp4;
+        struct icmp6_hdr *icmp6;
+        struct mpls_label *mpls;
+        const char *raw;
+    } header;
+    const char *payload;
+};
+
+int packet_get_layer_count(const struct packet *pkt);
+// return  0: success 
+// return -1: failed
+int packet_get_layer(const struct packet *pkt, int idx, struct layer *out);
+
+#define PACKET_FOREACH_LAYER_INORDER(pkt, layer) \
+    for (int i = 0; i < packet_get_layer_count(pkt) && packet_get_layer(pkt, i, &layer) == 0; i++)
+
+#define PACKET_FOREACH_LAYER_REVERSE(pkt, layer) \
+    for (int i = packet_get_layer_count(pkt) - 1; i >= 0 && packet_get_layer(pkt, i, &layer) == 0; i--)
+
+#define PACKET_GETALL_LAYERS(pkt, layers)                                          \
+    {                                                                              \
+        int size = sizeof(layers) / sizeof(layers[0]);                             \
+        int num = packet_get_layer_count(pkt);                                     \
+        if (num > size)                                                            \
+            num = size;                                                            \
+        for (int i = 0; i < num && packet_get_layer(pkt, i, &layers[i]) == 0; i++) \
+            /* void */;                                                            \
+        return num;                                                                \
+    }
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
diff --git a/include/stellar/packet.h b/include/stellar/packet.h
index 09d0726..62b03e7 100644
--- a/include/stellar/packet.h
+++ b/include/stellar/packet.h
@@ -1,180 +1,45 @@
-#ifndef _PACKET_PUB_H
-#define _PACKET_PUB_H
+#ifndef _PACKET_H
+#define _PACKET_H
 
 #ifdef __cplusplus
 extern "C"
 {
 #endif
 
-#include <string.h>
-#include <arpa/inet.h>
-#define __FAVOR_BSD 1
-#include <netinet/tcp.h>
-#include <netinet/udp.h>
-#include <netinet/ip.h>
-#include <netinet/ip6.h>
+#include <stdint.h>
 
-enum layer_proto
+#define MAX_SIDS 8
+struct sids
 {
-    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_GTPV1_U = 62,
-};
-
-struct raw_layer
-{
-    enum layer_proto type;
-    const char *hdr_ptr; // header pointer
-    const char *pld_ptr; // payload pointer
-    uint16_t hdr_offset; // header offset from data_ptr
-    uint16_t hdr_len;    // header length
-    uint16_t pld_len;    // payload length
-};
-
-#define MAX_SID_NUM 8
-struct sid_list
-{
-    uint16_t sid[MAX_SID_NUM];
+    uint16_t sid[MAX_SIDS];
     int used;
 };
+void packet_prepend_sids(struct packet *pkt, const struct sids *sids);
 
 enum packet_direction
 {
     PACKET_DIRECTION_OUTGOING = 0, // Internal -> External: 0
     PACKET_DIRECTION_INCOMING = 1, // External -> Internal: 1
 };
+enum packet_direction packet_get_direction(const struct packet *pkt);
 
 enum packet_action
 {
-    PACKET_ACTION_FORWARD = 0,
+    PACKET_ACTION_FORWARD = 0, // must be zero
     PACKET_ACTION_DROP = 1,
+    PACKET_ACTION_DEFER = 2, // TODO
 };
+void packet_set_action(struct packet *pkt, enum packet_action action);
+enum packet_action packet_get_action(const struct packet *pkt);
 
-enum packet_direction packet_get_direction(const struct packet *pkt);
 uint64_t packet_get_session_id(const struct packet *pkt);
-void packet_prepend_sid_list(struct packet *pkt, const struct sid_list *list);
 
-int packet_get_layer_count(const struct packet *pkt);
-const struct raw_layer *packet_get_raw_layer(const struct packet *pkt, int idx);
-
-const char *packet_get_data(const struct packet *pkt);
-uint16_t packet_get_len(const struct packet *pkt);
+const char *packet_get_raw_data(const struct packet *pkt);
+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);
 
-void packet_set_action(struct packet *pkt, enum packet_action action);
-enum packet_action packet_get_action(const struct packet *pkt);
-
-struct address
-{
-    uint8_t family; // AF_INET or AF_INET6
-    union
-    {
-        struct in_addr v4;  /* network order */
-        struct in6_addr v6; /* network order */
-    } data;
-};
-
-static inline int packet_get_addr(const struct packet *pkt, struct address *src_addr, struct address *dst_addr)
-{
-    const struct ip *ip4_hdr = NULL;
-    const struct ip6_hdr *ip6_hdr = NULL;
-    const struct raw_layer *layer = NULL;
-    int num = packet_get_layer_count(pkt);
-    for (int i = num - 1; i >= 0; i--)
-    {
-        layer = packet_get_raw_layer(pkt, i);
-        if (layer->type == LAYER_PROTO_IPV4)
-        {
-            ip4_hdr = (const struct ip *)layer->hdr_ptr;
-            if (src_addr != NULL)
-            {
-                src_addr->family = AF_INET;
-                src_addr->data.v4.s_addr = ip4_hdr->ip_src.s_addr;
-            }
-            if (dst_addr != NULL)
-            {
-                dst_addr->family = AF_INET;
-                dst_addr->data.v4.s_addr = ip4_hdr->ip_dst.s_addr;
-            }
-            return 0;
-        }
-        if (layer->type == LAYER_PROTO_IPV6)
-        {
-            ip6_hdr = (const struct ip6_hdr *)layer->hdr_ptr;
-            if (src_addr != NULL)
-            {
-                src_addr->family = AF_INET6;
-                src_addr->data.v6 = ip6_hdr->ip6_src;
-            }
-            if (dst_addr != NULL)
-            {
-                dst_addr->family = AF_INET6;
-                dst_addr->data.v6 = ip6_hdr->ip6_dst;
-            }
-            return 0;
-        }
-    }
-
-    return -1;
-}
-
-static inline int packet_get_port(const struct packet *pkt, uint16_t *src_port, uint16_t *dst_port)
-{
-    const struct tcphdr *tcp_hdr = NULL;
-    const struct udphdr *udp_hdr = NULL;
-    const struct raw_layer *layer = NULL;
-    int num = packet_get_layer_count(pkt);
-    for (int i = num - 1; i >= 0; i--)
-    {
-        layer = packet_get_raw_layer(pkt, i);
-        if (layer->type == LAYER_PROTO_TCP)
-        {
-            tcp_hdr = (const struct tcphdr *)layer->hdr_ptr;
-            src_port != NULL ? *src_port = tcp_hdr->th_sport : 0;
-            dst_port != NULL ? *dst_port = tcp_hdr->th_dport : 0;
-            return 0;
-        }
-        if (layer->type == LAYER_PROTO_UDP)
-        {
-            udp_hdr = (const struct udphdr *)layer->hdr_ptr;
-            src_port != NULL ? *src_port = udp_hdr->uh_sport : 0;
-            dst_port != NULL ? *dst_port = udp_hdr->uh_dport : 0;
-            return 0;
-        }
-    }
-
-    return -1;
-}
-
 #ifdef __cplusplus
 }
 #endif
diff --git a/include/stellar/session.h b/include/stellar/session.h
index 959ab50..5fb58fa 100644
--- a/include/stellar/session.h
+++ b/include/stellar/session.h
@@ -133,7 +133,7 @@ enum session_type session_get_type(const struct session *sess);
 
 enum session_state session_get_current_state(const struct session *sess);
 const struct packet *session_get0_current_packet(const struct session *sess);
-const char *session_get0_current_payload(const struct session *sess, size_t *payload_len);
+const char *session_get0_current_payload(const struct session *sess, uint16_t *payload_len);
 
 enum closing_reason session_get_closing_reason(const struct session *sess);
 enum session_direction session_get_direction(const struct session *sess);
diff --git a/include/stellar/stellar.h b/include/stellar/stellar.h
index 43d911f..598b279 100644
--- a/include/stellar/stellar.h
+++ b/include/stellar/stellar.h
@@ -56,7 +56,7 @@ int stellar_inject_tcp_rst(struct stellar *st, const struct session *sess, enum
 int stellar_inject_tcp_fin(struct stellar *st, const struct session *sess, enum flow_direction inject_dir);
 int stellar_inject_tcp_payload(struct stellar *st, const struct session *sess, enum flow_direction inject_dir, const char *payload, uint16_t len);
 int stellar_inject_udp_payload(struct stellar *st, const struct session *sess, enum flow_direction inject_dir, const char *payload, uint16_t len);
-int stellar_inject_ctrl_msg(struct stellar *st, const struct session *sess, const struct sid_list *sids, const char *msg, uint16_t len);
+int stellar_inject_ctrl_msg(struct stellar *st, const struct session *sess, const struct sids *sids, const char *msg, uint16_t len);
 
 int stellar_main(int argc, char **argv);