create new project.

除sapp和插件之外, 其他模块也经常有从某个层跳转到某个层的需求,
从sapp中剥离此部分代码, 独立成为一个公共库.

inc/MESA_jump_layer.h

@@ -0,0 +1,30 @@
+#ifndef __MESA_JUMP_LAYER_H_
+#define __MESA_JUMP_LAYER_H_ 1
+#endif
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include "stream.h"
+#include <netinet/ip.h>
+#include <netinet/ip6.h>
+
+
+const char *MESA_jump_layer_get_last_error(void);
+
+/*
+	The raw_layer_type and expect_layer_type refer to sapp_base.h->enum addr_type_t
+*/
+const void *MESA_net_jump_to_layer(const void *raw_data,  int raw_layer_type, int expect_layer_type);
+
+const void *MESA_net_jump_to_layer_greedy(const void *raw_data, int raw_layer_type, int expect_layer_type);
+
+
+const char *MESA_jump_layer_ipv4_ntop(const struct ip *ip4_hdr, char *out_buf, int buf_len );
+
+const char *MESA_jump_layer_ipv6_ntop(const struct ip6_hdr *ip6_hdr, char *out_buf, int buf_len);
+
+#ifdef __cplusplus
+}
+#endif