alignb 4
AppendBuf resb max_cmd_len+1 ; append=
KbdMap resb 256 ; Keyboard map
-PathPrefix resb 128 ; 128 bytes (comes from BOOTP size)
+BootFile resb 256 ; Boot file from DHCP packet
+PathPrefix resb 256 ; Path prefix derived from the above
FKeyName resb 10*FILENAME_MAX ; File names for F-key help
NumBuf resb 15 ; Buffer to load number
NumBufEnd resb 1 ; Last byte in NumBuf
DotQuadBuf resb 16 ; Buffer for dotted-quad IP address
IPOption resb 80 ; ip= option buffer
alignb 32
-BootFile resb 128 ; Boot file name from DHCP query
KernelName resb FILENAME_MAX ; Mangled name for kernel
KernelCName resb FILENAME_MAX ; Unmangled kernel name
InitRDCName resb FILENAME_MAX ; Unmangled initrd name
KernelSize resd 1 ; Size of kernel (bytes)
Stack resd 1 ; Pointer to reset stack
PXEEntry resd 1 ; !PXE API entry point
-MyIP resd 1 ; My IP address
-ServerIP resd 1 ; IP address of boot server
SavedSSSP resw 1 ; Our SS:SP while running a COMBOOT image
FBytes equ $ ; Used by open/getc
FBytes1 resw 1
SetupSecs resw 1 ; Number of setup sectors
A20Test resw 1 ; Counter for testing status of A20
CmdLineLen resw 1 ; Length of command line including null
-ServerPort resw 1 ; TFTP server port
ConfigFile resw 1 ; Socket for config file
PktTimeout resw 1 ; Timeout for current packet
KernelExtPtr resw 1 ; During search, final null pointer
LoadFlags resb 1 ; Loadflags from kernel
A20Tries resb 1 ; Times until giving up on A20
FuncFlag resb 1 ; == 1 if <Ctrl-F> pressed
+OverLoad resb 1 ; Set if DHCP packet uses "overloading"
alignb tftp_port_t_size
Sockets resb MAX_SOCKETS*tftp_port_t_size
query_bootp:
mov ax,ds
mov es,ax
- mov di,pxe_bootp_query_pkt
+ mov di,pxe_bootp_query_pkt_2
mov bx,PXENV_GET_CACHED_INFO
call far [PXENVEntry]
+ push word [pxe_bootp_query_pkt_2.status]
jc .pxe_err1
cmp ax,byte 0
je .pxe_ok
-.pxe_err1:
+.pxe_err1:
mov di,pxe_bootp_size_query_pkt
mov bx,PXENV_GET_CACHED_INFO
call writehex4
mov al, ' '
call writechr
- mov ax,[pxe_bootp_query_pkt.status]
+ pop ax ; Status
call writehex4
call crlf
+ jmp kaboom ; We're dead
.pxe_ok:
- mov eax,[trackbuf+bootp.yip] ; "Your" IP address
- mov [MyIP],eax
- call genipopt
+ pop cx ; Forget status
+ mov cx,[pxe_bootp_query_pkt_2.buffersize]
+ call parse_dhcp ; Parse DHCP packet
;
; Now, get the boot file and other info. This lives in the CACHED_REPLY
; packet (query info 3).
;
- mov [pxe_bootp_query_pkt.packettype], byte 3
mov [pxe_bootp_size_query_pkt.packettype], byte 3
- mov di,pxe_bootp_query_pkt
+ mov di,pxe_bootp_query_pkt_3
mov bx,PXENV_GET_CACHED_INFO
call far [PXENVEntry]
+ push word [pxe_bootp_query_pkt_3.status]
jc .pxe_err1
cmp ax,byte 0
jne .pxe_err1
- mov si,trackbuf+bootp.bootfile
- mov di,BootFile
- mov cx,128 >> 2
- rep movsd ; Copy bootfile name
+ ; Packet loaded OK...
+ pop cx ; Forget status
+ mov cx,[pxe_bootp_query_pkt_3.buffersize]
+ call parse_dhcp ; Parse DHCP packet
+;
+; Generate ip= option
+;
+ call genipopt
;
-; If packet 2 didn't contain a valid IP address, guess that it's in this
-; packet instead
+; Print IP address
;
mov eax,[MyIP]
- cmp eax, byte 0 ; 0.0.0.0 bad
- je .badip
- cmp al,224 ; 224..255.x.x.x
- jb .goodip
-.badip:
- mov eax,[trackbuf+bootp.yip] ; Hope this is better...
- mov [MyIP],eax
- call genipopt
-.goodip:
mov di,DotQuadBuf
push di
call gendotquad ; This takes network byte order input
ror eax,16 ; (BSWAP doesn't work on 386)
xchg ah,al
-;
-; Print IP address
-;
mov si,myipaddr_msg
call writestr
call writehex8
mov si,IPOption ; ***
call writestr ; ***
call crlf ; ***
-;
-; Save away the server IP and port number
-;
- mov eax,[trackbuf+bootp.sip]
- mov [ServerIP],eax
- mov [ServerPort], word TFTP_PORT
;
; Initialize UDP stack
ret
;
+; parse_dhcp
+;
+; Parse a DHCP packet. This includes dealing with "overloaded"
+; option fields (see RFC 2132, section 9.3)
+;
+; This should fill in the following global variables, if the
+; information is present:
+;
+; MyIP - client IP address
+; ServerIP - boot server IP address
+; Netmask - network mask
+; Gateway - default gateway router IP
+; BootFile - boot file name
+;
+; This assumes the DHCP packet is in "trackbuf" and the length
+; of the packet in in CX on entry.
+;
+
+parse_dhcp:
+ mov byte [OverLoad],0 ; Assume no overload
+ mov eax, [trackbuf+bootp.yip]
+ and eax, eax
+ jz .noyip
+ cmp al,224 ; Class D or higher -> bad
+ jae .noyip
+ mov [MyIP], eax
+.noyip:
+ mov eax, [trackbuf+bootp.sip]
+ and eax, eax
+ jz .nosip
+ cmp al,224 ; Class D or higher -> bad
+ jae .nosip
+ mov [ServerIP], eax
+.nosip:
+ sub cx, bootp.options
+ jbe .nooptions
+ mov si, trackbuf+bootp.option_magic
+ lodsd
+ cmp eax, BOOTP_OPTION_MAGIC
+ jne .nooptions
+ call parse_dhcp_options
+.nooptions:
+ mov si, trackbuf+bootp.bootfile
+ test byte [OverLoad],1
+ jz .nofileoverload
+ mov cx,128
+ call parse_dhcp_options
+ jmp short .parsed_file
+.nofileoverload:
+ cmp byte [si], 0
+ jz .parsed_file ; No bootfile name
+ mov di,BootFile
+ mov cx,32
+ rep movsd
+ xor al,al
+ stosb ; Null-terminate
+.parsed_file:
+ mov si, trackbuf+bootp.sname
+ test byte [OverLoad],2
+ jz .nosnameoverload
+ mov cx,64
+ call parse_dhcp_options
+.nosnameoverload:
+ ret
+
+;
+; Parse a sequence of DHCP options, pointed to by DS:SI; the field
+; size is CX -- some DHCP servers leave option fields unterminated
+; in violation of the spec.
+;
+parse_dhcp_options:
+.loop:
+ and cx,cx
+ jz .done
+
+ lodsb
+ dec cx
+ jz .done ; Last byte; must be PAD, END or malformed
+ cmp al, 0 ; PAD option
+ je .loop
+ cmp al,255 ; END option
+ je .done
+
+ ; Anything else will have a length field
+ mov dl,al ; DL <- option number
+ xor ax,ax
+ lodsb ; AX <- option length
+ dec cx
+ sub cx,ax ; Decrement bytes left counter
+ jb .done ; Malformed option: length > field size
+
+ cmp dl,1 ; SUBNET MASK option
+ jne .not_subnet
+ mov edx,[si]
+ mov [Netmask],edx
+ jmp short .opt_done
+
+.not_subnet:
+ cmp dl,3 ; ROUTER option
+ jne .not_router
+ mov edx,[si]
+ mov [Gateway],edx
+ jmp short .opt_done
+
+.not_router:
+ cmp dl,52 ; OPTION OVERLOAD option
+ jne .not_overload
+ mov dl,[si]
+ mov [OverLoad],dl
+ jmp short .opt_done
+
+.not_overload:
+ mov dl,67 ; BOOTFILE NAME option
+ jne .not_bootfile
+ push cx
+ mov di,BootFile
+ mov cx,ax
+ rep movsb
+ mov byte [di],0 ; Null-terminate
+ pop cx
+ jmp short .opt_done_noskip
+
+.not_bootfile:
+ ; Unknown option. Skip to the next one.
+.opt_done:
+ add si,ax
+.opt_done_noskip:
+ jmp short .loop
+.done:
+ ret
+
+;
; genipopt
;
; Generate an ip=<client-ip>:<boot-server-ip>:<gw-ip>:<netmask>
mov eax,'ip='
stosd
dec di
- mov eax,[trackbuf+bootp.yip]
+ mov eax,[MyIP]
call gendotquad
mov al,':'
stosb
- mov eax,[trackbuf+bootp.sip]
+ mov eax,[ServerIP]
call gendotquad
mov al,':'
stosb
-
- xor ebx,ebx ; Unknown netmask
- xor edx,edx ; Unknown router
-
- mov si,trackbuf+bootp.option_magic
- lodsd
- cmp eax,BOOTP_OPTION_MAGIC
- jne .parse_done ; Unknown option format
-.parseopt:
- lodsb
- cmp al,0 ; PAD option
- je .parseopt
- cmp al,255 ; END option
- je .parse_done
- cmp al,1 ; SUBNET MASK option
- jne .not_subnet
- inc si ; Skip length (always 4)
- lodsd ; Read subnet mask
- xchg ebx,eax ; Netmask: save in EBX
- jmp short .parseopt
-.not_subnet:
- cmp al,3 ; ROUTER option
- jne .not_router
- inc si ; Skip length (always 4)
- lodsd ; Read gateway address
- xchg edx,eax ; Router: save in EDX
- jmp short .parseopt
-.not_router:
- ; Unknown option. Read the length and skip ahead.
- xor ah,ah
- lodsb
- add si,ax
- jmp short .parseopt
-.parse_done:
- mov eax,edx ; Router
+ mov eax,[Netmask]
call gendotquad
mov al,':'
stosb
- mov eax,ebx ; Netmask
- call gendotquad ; Zero-terminates output!
+ mov eax,[Gateway]
+ call gendotquad ; Zero-terminates its output
sub di,IPOption
mov [IPOptionLen],di
popad
;
; PXE query packets partially filled in
;
-pxe_bootp_query_pkt:
+pxe_bootp_query_pkt_2:
.status: dw 0 ; Status
.packettype: dw 2 ; DHCPACK packet
.buffersize: dw trackbufsize ; Packet size
.buffer: dw trackbuf, 0 ; seg:off of buffer
.bufferlimit: dw trackbufsize ; Unused
+pxe_bootp_query_pkt_3:
+.status: dw 0 ; Status
+.packettype: dw 3 ; Boot server packet
+.buffersize: dw trackbufsize ; Packet size
+.buffer: dw trackbuf, 0 ; seg:off of buffer
+.bufferlimit: dw trackbufsize ; Unused
+
pxe_bootp_size_query_pkt:
.status: dw 0 ; Status
.packettype: dw 2 ; DHCPACK packet
db 'tsize option required', 0 ; Error message
tftp_opt_err_len equ ($-tftp_opt_err)
- alignb 2
+ alignb 4, db 0
ack_packet_buf: dw TFTP_ACK, 0 ; TFTP ACK packet
;
+; IP information (initialized to "unknown" values)
+MyIP dd 0 ; My IP address
+ServerIP dd 0 ; IP address of boot server
+Netmask dd 0 ; Netmask of this subnet
+Gateway dd 0 ; Default router
+ServerPort dw TFTP_PORT ; TFTP server port
+
+;
; Variables that are uninitialized in SYSLINUX but initialized here
;
ClustSize dw TFTP_BLOCKSIZE ; Bytes/cluster
projects / platform / upstream / syslinux.git / commitdiff