From 97530bd26972b047c912b1d0c7fc932d722a3a86 Mon Sep 17 00:00:00 2001
From: hpa <hpa>
Date: Tue, 28 Dec 2004 21:40:46 +0000
Subject: [PATCH] Add support for non-FQDN hostnames.

---
 NEWS          |  1 +
 dnsresolv.inc | 15 +++++++++++++--
 pxelinux.asm  | 22 ++++++++++++++++++++++
 3 files changed, 36 insertions(+), 2 deletions(-)

diff --git a/NEWS b/NEWS
index 20bf6b3..22c0b4e 100644
--- a/NEWS
+++ b/NEWS
@@ -12,6 +12,7 @@ Changes in 3.00:
           built in its own subdirectory.  In particular, "mtools" is
 	  the unprivileged installer which uses mtools; "unix" is the
 	  privileged installer which uses system calls.
+	* SYSLINUX: Completely rewritten DOS installer in C.
 	* ALL: "label" statement information is now stored in a
 	  compressed format, which means that a lot more labels are
 	  permitted (500-1000 in a typical configuration, but depends
diff --git a/dnsresolv.inc b/dnsresolv.inc
index 4364c44..d10c7d1 100644
--- a/dnsresolv.inc
+++ b/dnsresolv.inc
@@ -34,11 +34,14 @@ DNS_MAX_SERVERS equ 4			; Max no of DNS servers
 ; Assumes DS == ES.  Change references to [bx] to [es:bx] to remove
 ; that assumption.
 ;
+; On return, DX contains the number of dots encountered.
+;
 dns_mangle:
 		push ax
 		push bx
-.nostart:
+		xor dx,dx
 .isdot:
+		inc dx
 		xor al,al
 		mov bx,di
 		stosb
@@ -55,6 +58,7 @@ dns_mangle:
 		jmp .getbyte
 .endstring:
 		dec si
+		dec dx			; We always counted one high
 		cmp byte [bx],0
 		jz .done
 		xor al,al
@@ -158,6 +162,7 @@ dns_skiplabel:
 		alignb 2, db 0
 DNSSendBuf	resb DNS_MAX_PACKET
 DNSRecvBuf	resb DNS_MAX_PACKET
+LocalDomain	resb 256		; Max possible length
 DNSServers	resd DNS_MAX_SERVERS
 
 		section .data
@@ -204,9 +209,15 @@ dns_resolv:
 		stosw
 		
 		call dns_mangle		; Convert name to DNS labels
-
 		push si			; Save pointer to after DNS string
 
+		and dx,dx
+		jnz .fqdn		; If we have dots, assume it's FQDN
+		dec di			; Remove final null
+		mov si,LocalDomain
+		call strcpy		; Uncompressed DNS label set so it ends in null
+.fqdn:
+
 		mov ax,htons(1)
 		stosw			; QTYPE  = 1 = A
 		stosw			; QCLASS = 1 = IN
diff --git a/pxelinux.asm b/pxelinux.asm
index 038680c..2b3a811 100644
--- a/pxelinux.asm
+++ b/pxelinux.asm
@@ -517,6 +517,12 @@ have_entrypoint:
 		pop es				; Restore CS == DS == ES
 
 ;
+; Network-specific initialization
+;
+		xor ax,ax
+		mov [LocalDomain],al		; No LocalDomain received
+
+;
 ; Now attempt to get the BOOTP/DHCP packet that brought us life (and an IP
 ; address).  This lives in the DHCPACK packet (query info 2).
 ;
@@ -2051,6 +2057,7 @@ gendotquad:
 ; Gateway	- default gateway router IP
 ; BootFile	- boot file name
 ; DNSServers	- DNS server IPs
+; LocalDomain	- Local domain name
 ;
 ; This assumes the DHCP packet is in "trackbuf" and the length
 ; of the packet in in CX on entry.
@@ -2156,6 +2163,7 @@ parse_some_dhcp_options:
 		cmp dl,6	; DNS SERVERS option
 		jne .not_dns
 		pusha
+		mov cx,ax
 		shr cx,2
 		cmp cl,DNS_MAX_SERVERS
 		jna .oklen
@@ -2168,6 +2176,20 @@ parse_some_dhcp_options:
 		jmp .opt_done
 .not_dns:
 
+		cmp dl,15	; DNS LOCAL DOMAIN option
+		jne .not_localdomain
+		pusha
+		mov bx,si
+		add bx,ax
+		xor ax,ax
+		xchg [bx],al	; Zero-terminate option
+		mov di,LocalDomain
+		call dns_mangle	; Convert to DNS label set
+		mov [bx],al	; Restore ending byte
+		popa
+		jmp .opt_done
+.not_localdomain:
+
 		cmp dl,43	; VENDOR ENCAPSULATED option
 		jne .not_vendor
 		pusha
-- 
2.7.4