diff options
Diffstat (limited to 'dnsresolv.inc')
| -rw-r--r-- | dnsresolv.inc | 26 |
1 files changed, 14 insertions, 12 deletions
diff --git a/dnsresolv.inc b/dnsresolv.inc index af48b74c..47573b91 100644 --- 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? |