Correct bogus register usage

diff --git a/dnsresolv.inc b/dnsresolv.inc
index af48b74..47573b9 100644 (file)
--- a/dnsresolv.inc
+++ b/dnsresolv.inc
@@ -21,7 +21,7 @@
 DNS_PORT       equ htons(53)           ; Default DNS port 
 DNS_MAX_PACKET equ 512                 ; Defined by protocol
 ; TFTP uses the range 49152-57343; avoid that range
-DNS_LOCAL_PORT equ htons(5353)         ; All local DNS queries come from this port #
+DNS_LOCAL_PORT equ htons(35000)        ; All local DNS queries come from this port #
 DNS_MAX_SERVERS equ 4                  ; Max no of DNS servers
 
                section .text
@@ -66,7 +66,7 @@ dns_mangle:
 
 ;
 ; Compare two sets of DNS labels, in DS:SI and ES:DI; the one in SI
-; is allowed pointers relative to a packet address in BX.
+; is allowed pointers relative to a packet in DNSRecvBuf.
 ;
 ; Assumes DS == ES.  ZF = 1 if same; no registers changed.
 ; (Note: change reference to [di] to [es:di] to remove DS == ES assumption)
@@ -81,7 +81,7 @@ dns_compare:
                and al,03Fh                     ; Get pointer value
                mov ah,al                       ; ... in network byte order!
                lodsb
-               mov si,bx
+               mov si,DNSRecvBuf
                add si,ax
                jmp .label
 .noptr:
@@ -164,7 +164,7 @@ pxe_udp_write_pkt_dns:
 .lport:                dw DNS_LOCAL_PORT       ; Local port
 .rport:                dw DNS_PORT             ; Remote port
 .buffersize:   dw 0                    ; Size of packet
-.buffer:       dw 0, DNSSendBuf        ; seg:off of buffer
+.buffer:       dw DNSSendBuf, 0        ; off, seg of buffer
 
 pxe_udp_read_pkt_dns:
 .status:       dw 0                    ; Status
@@ -173,12 +173,13 @@ pxe_udp_read_pkt_dns:
 .rport:                dw DNS_PORT             ; Remote port
 .lport:                dw DNS_LOCAL_PORT       ; Local port
 .buffersize:   dw DNS_MAX_PACKET       ; Max packet size
-.buffer:       dw 0, DNSRecvBuf        ; seg:off of buffer
+.buffer:       dw DNSRecvBuf, 0        ; off, seg of buffer
 
 LastDNSServer  dw DNSServers
 
                section .text
 dns_resolv:
+               push si
                push di
                push cx
                push dx
@@ -214,7 +215,7 @@ dns_resolv:
                mov dx,PKT_TIMEOUT
                mov cx,PKT_RETRY
 .backoff:
-               mov di,[DNSServers]
+               mov di,DNSServers
 .servers:
                cmp di,[LastDNSServer]
                jb .moreservers
@@ -228,6 +229,7 @@ dns_resolv:
                pop dx
                pop cx
                pop di
+               pop si
                ret
 
 .moreservers:
@@ -271,7 +273,7 @@ dns_resolv:
                jnz .waitrecv
 
                ; Got a packet, deal with it...
-               mov di,DNSRecvBuf
+               mov si,DNSRecvBuf
                lodsw
                cmp ax,[DNSSendBuf]             ; ID
                jne .waitrecv                   ; Not ours
@@ -282,10 +284,10 @@ dns_resolv:
                jnz .badness
                
                lodsw
-               xchg ah,al
+               xchg ah,al                      ; ntohs
                mov cx,ax                       ; Questions echoed
                lodsw
-               xchg ah,al
+               xchg ah,al                      ; ntohs
                push ax                         ; Replies
                lodsw                           ; NS records
                lodsw                           ; Authority records
@@ -293,7 +295,7 @@ dns_resolv:
                jcxz .qskipped
 .skipq:
                call dns_skiplabel              ; Skip name
-               add di,4                        ; Skip question trailer
+               add si,4                        ; Skip question trailer
                loop .skipq
 
 .qskipped:
@@ -301,12 +303,12 @@ dns_resolv:
                jcxz .badness
 
 .parseanswer:
-               mov si,DNSSendBuf+dnshdr_size
+               mov di,DNSSendBuf+dnshdr_size
                call dns_compare
                pushf
                call dns_skiplabel
                mov ax,[si+8]                   ; RDLENGHT
-               xchg ah,al                      ; Convert to host byte order
+               xchg ah,al                      ; ntohs
                popf
                jnz .notsame
                cmp word [si],htons(1)          ; TYPE = A?