Checkpoint: parse tsize OACK packet.

diff --git a/pxelinux.asm b/pxelinux.asm
index b51cc1a..e407ad5 100644 (file)
--- a/pxelinux.asm
+++ b/pxelinux.asm
@@ -172,9 +172,9 @@ fat_seg             equ 0h                  ; BOGUS
                struc tftp_port_t
 tftp_localport resw 1                  ; Local port number     (0 = not in use)
 tftp_remoteport        resw 1                  ; Remote port number
-tftp_localip   resd 1                  ; Local IP address
 tftp_remoteip  resd 1                  ; Remote IP address
 tftp_filepos   resd 1                  ; Position within file
+tftp_filesize  resd 1                  ; Total file size
                endstruc
 
 %if (tftp_port_t_size & (tftp_port_t_size-1))
@@ -2189,7 +2189,6 @@ tftp_connect:
                mov di,packet_buf_size
                mov [pxe_udp_read_pkt.buffersize],di
                mov eax,[bootp.yip]     ; Our own IP
-               mov [bx+tftp_localip],eax
                mov [pxe_udp_read_pkt.dip],eax
                mov [pxe_udp_read_pkt.lport],bx
                mov di,pxe_udp_read_pkt
@@ -2227,50 +2226,84 @@ tftp_connect:
                mov [bx+tftp_remoteport],ax
 
                movzx eax,word [pxe_udp_read_pkt.buffersize]
-               sub eax, byte 4
-               jb .failure                     ; Garbled reply
+               sub eax, byte 2
+               jb near .failure                ; Garbled reply
                mov [bx+tftp_filepos], eax
 
                cmp word [packet_buf], TFTP_ERROR
-               je .bailnow                     ; ERROR reply: don't try again
+               je near .bailnow                ; ERROR reply: don't try again
 
-               ; SHOULD REALLY SEND ERROR PACKET HERE!
-               cmp word [packet_buf], TFTP_DATA
-               je .no_tsize
-
-               ; SHOULD REALLY SEND ERROR PACKET HERE!
                cmp word [packet_buf], TFTP_OACK
-               jne .failure                    ; Non-OACK reply -> error
-
-               cmp word [packet_buf+2], htons(1)
-               jne .failure                    ; Packet # != 1
+               jne .err_reply
 
                ; Now we need to parse the OACK packet to get the transfer
                ; size.
 
-               ; **** WE SHOULD NOT ACK THIS PACKET YET ****
-.ackpacket:    mov word [packet_buf], TFTP_ACK
-               mov [pxe_udp_write_pkt.buffersize], word 4
+.parse_oack:   mov cx,[pxe_udp_read_pkt.buffersize]
+               mov si,packet_buf+2
+               sub cx,byte 2
+               jz .no_tsize                    ; No options acked
+.get_opt_name: mov di,si
+               mov bx,si
+.opt_name_loop:        lodsb
+               and al,al
+               jz .got_opt_name
+               or al,20h                       ; Convert to lowercase
+               stosb
+               loop .opt_name_loop
+               ; We ran out, and no final null
+               jmp short .err_reply
+.got_opt_name: dec cx
+               jz .failure                     ; Option w/o value
+               push cx
+               mov si,bx
+               mov di,tsize_str
+               mov cx,tsize_len
+               repe cmpsb
+               pop cx
+               jne .err_reply                  ; Bad option -> error
+.get_value:    xor eax,eax
+               xor edx,edx
+.value_loop:   lodsb
+               and al,al
+               jz .got_value
+               sub al,'0'
+               cmp al, 9
+               ja .err_reply
+               imul edx,10
+               add edx,eax
+               loop .value_loop
+               ; Ran out before final null
+               jmp short .err_reply
+.got_value:    dec cx
+               jnz .err_reply                  ; Not end of packet
+               ; Move size into DX:AX (old calling convention)
+               ; but let EAX == DX:AX
+               mov eax,edx
+               shr edx,16
+
+               xor edi,edi
 
-               mov al,'A'
-               call writechr
-               
-               mov di,pxe_udp_write_pkt
-               mov bx,0033h            ; PXENV_UDP_WRITE
-               call far [PXENVEntry]
-               jc .failure
-               cmp word [pxe_udp_write_pkt.status],byte 0
-               jne .failure
-       
                ; Success, done!
                pop si                  ; Junk  
                pop si                  ; We want the packet ptr in SI
+
+               mov [si+tftp_filesize],eax
+               mov [si+tftp_filepos],edi
+
                pop bp                  ; Junk
                pop bp                  ; Junk (retry counter)
                and bp,bp               ; BP != 0, ZF <- 0
                pop bp
                ret
 
+.err_reply:    ; Option negotiation error.  Send ERROR reply.
+               mov word [pxe_udp_write_pkt.buffer],tftp_opt_err
+               mov word [pxe_udp_write_pkt.buffersize],tftp_opt_err_len
+               mov di,pxe_udp_write_pkt
+               mov bx,0033h            ; PXENV_UDP_WRITE
+               call far [PXENVEntry]
+
 .no_tsize:     mov si,err_oldtftp
                call writestr
                jmp kaboom
@@ -3387,6 +3420,12 @@ MySocket dw 32768                ; Local UDP socket counter
 ;
 tftp_tail      db 'octet', 0, 'tsize' ,0, '0', 0       ; Octet mode, request size
 tftp_tail_len  equ ($-tftp_tail)
+tsize_str      db 'tsize', 0
+tsize_len      equ ($-tsize_str)
+tftp_opt_err   dw TFTP_ERROR                           ; ERROR packet
+               dw htons(8)                             ; ERROR 8: bad options
+               db 'tsize option required', 0           ; Error message
+tftp_opt_err_len equ ($-tftp_opt_err)
 
 ;
 ; Stuff for the command line; we do some trickery here with equ to avoid