switched header->body_size to a u32, means that one can encrypt/decrypt 4.2GB with only one header sent

3 files changed, 14 insertions, 13 deletions

diff --git a/client.c b/client.c
index aa58a92..b15a198 100644
--- a/client.c
+++ b/client.c
@@ -41,7 +41,8 @@ static void send_data(struct connection * const state)
             close(data_fd);
             data_fd = -1;
         } else {
-            LOG(NOTICE, "Send DATA: %zd", bytes_read);
+            LOG(NOTICE, "Send DATA: %zd bytes, buffer capacity %0.2f%% unused", bytes_read,
+                100.0f - ((float)bytes_read / sizeof(buf)) * 100.0f);
         }
     }
 }
diff --git a/protocol.c b/protocol.c
index 8f43584..f73dd77 100644
--- a/protocol.c
+++ b/protocol.c
@@ -161,7 +161,7 @@ static enum recv_return run_protocol_callback(struct connection * const state,
     struct protocol_header const * const hdr = (struct protocol_header *)decrypted->pointer;
     enum header_types type = (enum header_types)hdr->pdu_type;
     size_t min_size = 0;
-    uint16_t size = hdr->body_size;
+    uint32_t size = hdr->body_size;
 
     switch (state->state) {
         case CONNECTION_INVALID:
@@ -201,25 +201,25 @@ static void header_ntoh(struct protocol_header * const hdr)
 {
     hdr->magic = ntohl(hdr->magic);
     hdr->pdu_type = ntohs(hdr->pdu_type);
-    hdr->body_size = ntohs(hdr->body_size);
+    hdr->body_size = ntohl(hdr->body_size);
 }
 
 static enum recv_return validate_header(struct protocol_header const * const hdr, size_t buffer_size)
 {
     enum header_types type = (enum header_types)hdr->pdu_type;
-    uint16_t size;
+    uint32_t size;
 
     if (hdr->magic != PROTOCOL_MAGIC) {
         return RECV_CORRUPT_PACKET;
     }
 
     size = hdr->body_size;
-    /* following check does not make sense if sizeof(header.body_size) == 2 and WINDOW_SIZE >= 65535 */
-#if WINDOW_SIZE < 65535
+    /* following check does not make sense if sizeof(header.body_size) == 2 and WINDOW_SIZE >= (65535*2) */
+#if WINDOW_SIZE < (65535*2)
     if (size > WINDOW_SIZE) {
         return RECV_CORRUPT_PACKET;
     }
-#elif WINDOW_SIZE > 65535
+#elif WINDOW_SIZE > (65535*2)
 #error "Remember to change that code part if you've changed the type of header.body_size e.g. to uint32_t"
 #endif
     if (size > buffer_size) {
@@ -416,13 +416,13 @@ enum recv_return process_received(struct connection * const state,
  * PDU send functionality *
  **************************/
 
-static void protocol_response(void * const buffer, uint16_t body_and_payload_size, enum header_types type)
+static void protocol_response(void * const buffer, uint32_t body_and_payload_size, enum header_types type)
 {
     struct protocol_header * const header = (struct protocol_header *)buffer;
 
     header->magic = htonl(PROTOCOL_MAGIC);
     header->pdu_type = htons((uint16_t)type);
-    header->body_size = htons(body_and_payload_size - sizeof(*header));
+    header->body_size = htonl(body_and_payload_size - sizeof(*header));
 }
 
 void protocol_response_client_auth(unsigned char out[CRYPT_PACKET_SIZE_CLIENT_AUTH],
diff --git a/protocol.h b/protocol.h
index 1232fbb..1a7b6b5 100644
--- a/protocol.h
+++ b/protocol.h
@@ -11,8 +11,8 @@
 #define PROTOCOL_MAGIC 0xBAADC0DE
 #define PROTOCOL_VERSION 0xDEADCAFE
 #define PROTOCOL_TIME_STRLEN 32
-#define WINDOW_SIZE 65535
-#if WINDOW_SIZE > 65535
+#define WINDOW_SIZE (65535*2)
+#if WINDOW_SIZE > (65535*2)
 #error "Window size is limited by sizeof(header.body_size)"
 #endif
 
@@ -52,8 +52,8 @@ enum header_types {
 
 struct protocol_header {
     uint32_t magic;
-    uint16_t pdu_type;
-    uint16_t body_size;
+    uint32_t pdu_type;
+    uint32_t body_size;
 } PROTOCOL_ATTRIBUTES;
 
 struct protocol_client_auth {