Correctly parse the servers accept connect in 0.6

src/bss/teeworlds.asm

@@ -25,9 +25,13 @@ socket resb 4
 ; the compression flag
 ; if the compression flag is set there will be a decompressed payload in
 ; the label decompressed_packet_payload
-udp_recv_buf resb 7
+udp_recv_buf resb PACKET_HEADER_LEN
 packet_payload resb NET_MAX_PACKETSIZE ; 1400
 
+; 0.6.4 packet header offsets
+udp_recv6_buf resb PACKET6_HEADER_LEN
+packet6_payload resb NET_MAX_PACKETSIZE ; 1400
+
 ; only set if the packet is compressed
 ; otherwise look at the label packet_payload
 decompressed_packet_payload resb NET_MAX_PAYLOAD ; 1391

src/on_packet.asm

@@ -156,7 +156,7 @@ on_packet_end:
 on_packet6:
 
     push rax
-    mov rax, udp_recv_buf
+    mov rax, udp_recv6_buf
     call unpack_packet_header6
     pop rax
 

src/receive_control6.asm

@@ -13,13 +13,13 @@ on_ctrl6_msg_connect_accept:
 on_ctrl6_msg_close:
     push rax
 
-    mov rax, [packet_payload + 1]
+    mov rax, [packet6_payload + 1]
     cmp rax, 0
     je .on_ctrl6_msg_close_no_reason
 
 .on_ctrl6_msg_close_reason:
     print_label s_got_disconnect_with_reason
-    lea rax, [packet_payload + 1]
+    lea rax, [packet6_payload + 1]
     print_c_str rax
     call print_newline
     jmp .on_ctrl6_msg_close_end
@@ -37,7 +37,7 @@ on_ctrl6_message:
 
     print_label s_got_ctrl_msg
 
-    mov al, [udp_recv_buf + PACKET_HEADER_LEN]
+    mov al, [udp_recv6_buf + PACKET6_HEADER_LEN]
     call println_uint32
 
     cmp al, MSG6_CTRL_CONNECTACCEPT

src/teeworlds_asmr.asm

@@ -157,10 +157,24 @@ section .text
 %include "src/client_info.asm"
 %include "src/on_chat.asm"
 
+get_recv_buf:
+    ; returns into rax either `udp_recv_buf` or `udp_recv6_buf`
+    ; depending on the current connection version
+    mov al, byte [connection_version]
+    cmp al, 7
+    je .version7
+    .version6:
+    mov rax, udp_recv6_buf
+    jmp .end
+    .version7:
+    mov rax, udp_recv_buf
+    .end:
+    ret
+
 print_udp:
     print_label s_got_udp
     ; hexdump
-    mov rax, udp_recv_buf
+    call get_recv_buf
     mov rdi, [udp_read_len]
     call print_hexdump
     call print_newline
@@ -178,6 +192,7 @@ on_udp_packet:
 
 pump_network:
     ; print_label s_non_blocking_read
+    call get_recv_buf
     call recv_udp
     mov rax, [udp_read_len]
     test rax, rax

src/udp.asm

@@ -151,14 +151,24 @@ open_socket:
     ret
 
 recv_udp:
-    ; recv_udp
+    ; recv_udp [rax]
+    ;  rax = buffer to write to
+    ;
+    ; example call:
+    ;
+    ; mov rax, udp_recv_buf
+    ; call recv_udp
     ;
     ; listens for udp packet on the
-    ; `socket` and fills the `udp_recv_buf`
+    ; `socket` and fills the buffer in rax
+    ; which usually is `udp_recv_buf` or `udp_recv6_buf`
     push_registers
+    ; output buffer
+    mov r9, rax
+
     mov rax, SYS_RECVFROM
     movzx rdi, byte [socket] ; then only set the lowest byte
-    lea rsi, udp_recv_buf
+    mov rsi, r9 ; pointer to buffer `udp_recv_buf` or `udp_recv6_buf`
     mov rdx, NET_MAX_PACKETSIZE
     ; flags
     xor r10, r10