diff options
Diffstat (limited to 'core/pxelinux.asm')
| -rw-r--r-- | core/pxelinux.asm | 34 |
1 files changed, 23 insertions, 11 deletions
diff --git a/core/pxelinux.asm b/core/pxelinux.asm index 9d9d5b4d..58201a0b 100644 --- a/core/pxelinux.asm +++ b/core/pxelinux.asm @@ -1105,7 +1105,17 @@ searchdir: ; SI -> first byte of options; [E]CX -> byte count .parse_oack: jcxz .done_pkt ; No options acked + .get_opt_name: + ; If we find an option which starts with a NUL byte, + ; (a null option), we're either seeing garbage that some + ; TFTP servers add to the end of the packet, or we have + ; no clue how to parse the rest of the packet (what is + ; an option name and what is a value?) In either case, + ; discard the rest. + cmp byte [si],0 + je .done_pkt + mov di,si mov bx,si .opt_name_loop: lodsb @@ -1115,10 +1125,10 @@ searchdir: stosb loop .opt_name_loop ; We ran out, and no final null - jmp .err_reply + jmp .done_pkt ; Ignore runt option .got_opt_name: ; si -> option value dec cx ; bytes left in pkt - jz .err_reply ; Option w/o value + jz .done_pkt ; Option w/o value, ignore ; Parse option pointed to by bx; guaranteed to be ; null-terminated. @@ -1141,7 +1151,8 @@ searchdir: pop si pop cx - jmp .err_reply ; Non-negotiated option returned + ; Non-negotiated option returned, no idea what it means... + jmp .err_reply .get_value: pop si ; si -> option value pop cx ; cx -> bytes left in pkt @@ -1221,13 +1232,13 @@ searchdir: pop es jmp .done_pkt -.err_reply: ; Option negotiation error. Send ERROR reply. +.err_reply: ; TFTP protocol error. Send ERROR reply. ; ServerIP and gateway are already programmed in mov si,[bp-6] mov ax,[si+tftp_remoteport] mov word [pxe_udp_write_pkt.rport],ax - mov word [pxe_udp_write_pkt.buffer],tftp_opt_err - mov word [pxe_udp_write_pkt.buffersize],tftp_opt_err_len + mov word [pxe_udp_write_pkt.buffer],tftp_proto_err + mov word [pxe_udp_write_pkt.buffersize],tftp_proto_err_len mov di,pxe_udp_write_pkt mov bx,PXENV_UDP_WRITE call pxenv @@ -2725,12 +2736,13 @@ tftp_opt_table: tftp_opts equ ($-tftp_opt_table)/6 ; -; Error packet to return on options negotiation error +; Error packet to return on TFTP protocol error +; Most of our errors are OACK parsing errors, so use that error code ; -tftp_opt_err dw TFTP_ERROR ; ERROR packet - dw TFTP_EOPTNEG ; ERROR 8: bad options - db 'tsize option required', 0 ; Error message -tftp_opt_err_len equ ($-tftp_opt_err) +tftp_proto_err dw TFTP_ERROR ; ERROR packet + dw TFTP_EOPTNEG ; ERROR 8: OACK error + db 'TFTP protocol error', 0 ; Error message +tftp_proto_err_len equ ($-tftp_proto_err) alignz 4 ack_packet_buf: dw TFTP_ACK, 0 ; TFTP ACK packet |