pkt_unpack_struct

code/common/packets/packet.c

@@ -36,3 +36,22 @@ int32_t pkt_header_decode(pkt_header *table, void *data, size_t datalen) {
 
     return pkt_validate_eof_msg(&uc);
 }
+
+int32_t pkt_unpack_struct(cw_unpack_context *uc, pkt_desc *desc, void *raw_blob, uint32_t blob_size) {
+    uint8_t *blob = (uint8_t*)raw_blob;
+    for (pkt_desc *field = desc; field->type != 0; ++field) {
+        cw_unpack_next(uc);
+        if (uc->item.type != field->type) return -1; // unexpected field
+        switch (field->type) {
+            case CWP_ITEM_POSITIVE_INTEGER: {
+                zpl_memcopy(blob + field->offset, (uint8_t*)uc->item.as.u64, field->size);
+            }break;
+            default: {
+                zpl_printf("[WARN] unsupported pkt field type %lld !\n", field->type); 
+                return -1; // unsupported field
+            }break;
+        }
+    }
+    
+    return 0;
+}

code/common/packets/packet_utils.h

@@ -1,4 +1,5 @@
 #pragma once
+#include "zpl.h"
 #include "packet.h"
 #include "cwpack/cwpack.h"
 
@@ -29,3 +30,32 @@ inline int32_t pkt_validate_eof_msg(cw_unpack_context *uc) {
     if (uc->return_code != CWP_RC_END_OF_INPUT) return -1; // not finished yet but should be?
     return 0;
 }
+
+#ifndef PKT_OFFSETOF
+#if defined(_MSC_VER) || defined(ZPL_COMPILER_TINYC)
+#    define PKT_OFFSETOF(Type, element) ((size_t) & (((Type *)0)->element))
+#else
+#    define PKT_OFFSETOF(Type, element) __builtin_offsetof(Type, element)
+#endif
+#    define PKT_FIELD_SIZEOF(type, member) sizeof(((type *)0)->member)
+#endif
+
+#ifndef PKT_STRUCT_PTR
+#define PKT_STRUCT_PTR(a) (void*)a, (uint32_t)sizeof(*a)
+#endif
+
+#ifndef PKT_FIELD
+#define PKT_FIELD(k, t, a) .type = k, .offset = PKT_OFFSETOF(t, a), .size = PKT_FIELD_SIZEOF(t,a)
+#endif
+
+#ifndef PKT_END
+#define PKT_END .type = CWP_NOT_AN_ITEM
+#endif
+
+typedef struct pkt_desc {
+    cwpack_item_types type;
+    size_t offset;
+    size_t size;
+} pkt_desc;
+    
+int32_t pkt_unpack_struct(cw_unpack_context *uc, pkt_desc *desc, void *raw_blob, uint32_t blob_size);

code/common/packets/pkt_01_welcome.c

@@ -4,6 +4,12 @@
 
 #define PKT_01_WELCOME_ARGS 2
 
+pkt_desc pkt_01_welcome_desc[3] = {
+    { PKT_FIELD(CWP_ITEM_POSITIVE_INTEGER, pkt_01_welcome, chunk_size) },
+    { PKT_FIELD(CWP_ITEM_POSITIVE_INTEGER, pkt_01_welcome, chunk_amount) },
+    { PKT_END },
+};
+
 size_t pkt_01_welcome_encode(pkt_01_welcome *table) {
     cw_pack_context pc = {0};
     pkt_pack_msg(&pc, PKT_01_WELCOME_ARGS);
@@ -17,26 +23,17 @@ size_t pkt_01_welcome_encode(pkt_01_welcome *table) {
 int32_t pkt_01_welcome_decode(pkt_01_welcome *table, pkt_header *header) {
     cw_unpack_context uc = {0};
     pkt_unpack_msg(&uc, header, PKT_01_WELCOME_ARGS);
+    pkt_unpack_struct(&uc, header, PKT_STRUCT_PTR(table));
 
-    cw_unpack_next(&uc);
+    return pkt_validate_eof_msg(&uc);
-    if (uc.item.type != CWP_ITEM_POSITIVE_INTEGER) return -1; // expected chunk size
-    table->chunk_size = (uint16_t)uc.item.as.u64;
-
-    cw_unpack_next(&uc);
-    if (uc.item.type != CWP_ITEM_POSITIVE_INTEGER) return -1; // expected chunk amount
-    table->chunk_amount = (uint16_t)uc.item.as.u64;
-
-    return pkt_validate_eof_msg(&uc);;
 }
 
 int32_t pkt_01_welcome_handler(pkt_header *header) {
-#if 0
+#if 1
     pkt_01_welcome table;
     pkt_01_welcome_decode(&table, header);
 
     zpl_printf("we received: chunk_size: %d and chunk_amount: %d\n", table.chunk_size, table.chunk_amount);
-
-     do STUFF
 #endif
     return 0;
 }