From ae37edcb775fc33d56eb076f33b97ed272c132b4 Mon Sep 17 00:00:00 2001
From: Bjorn Andersson <flex@kryo.se>
Date: Sat, 24 Jun 2006 12:44:26 +0000
Subject: [PATCH] compression in server response

---
 dns.c | 21 +++++++++------------
 1 file changed, 9 insertions(+), 12 deletions(-)

diff --git a/dns.c b/dns.c
index 0d7d1f3..776c3e2 100644
--- a/dns.c
+++ b/dns.c
@@ -352,7 +352,6 @@ dns_read(int fd, char *buf, int buflen)
 	return 0;
 }
 
-
 static int
 host2dns(const char *host, char *buffer, int size)
 {
@@ -386,6 +385,7 @@ dnsd_send(int fd, struct query *q, char *data, int datalen)
 	int len;
 	char *p;
 	char buf[64*1024];
+	short name;
 	HEADER *header;
 
 	memset(buf, 0, sizeof(buf));
@@ -406,24 +406,21 @@ dnsd_send(int fd, struct query *q, char *data, int datalen)
 
 	p = buf + sizeof(HEADER);
 	
+	name = 0xc000 | ((p - buf) & 0x3fff);
 	p += host2dns(q->name, p, strlen(q->name));
 	PUTSHORT(q->type, p);
 	PUTSHORT(C_IN, p);
 	
-	p += host2dns(q->name, p, strlen(q->name));	
+	PUTSHORT(name, p);
 	PUTSHORT(q->type, p);
 	PUTSHORT(C_IN, p);
 	PUTLONG(0, p);
 
 	q->id = 0;
 
-	if(datalen > 0) {
-		PUTSHORT(datalen, p);
-		memcpy(p, data, datalen);
-		p += datalen;
-	} else {
-		PUTSHORT(0, p);
-	}
+	PUTSHORT(datalen, p);
+	memcpy(p, data, datalen);
+	p += datalen;
 
 	len = p - buf;
 	sendto(fd, buf, len, 0, (struct sockaddr*)&q->from, q->fromlen);
@@ -481,9 +478,7 @@ dnsd_read(int fd, struct query *q, char *buf, int buflen)
 	addrlen = sizeof(struct sockaddr);
 	r = recvfrom(fd, packet, sizeof(packet), 0, (struct sockaddr*)&from, &addrlen);
 
-	if(r == -1) {
-		perror("recvfrom");
-	} else {
+	if (r >= sizeof(HEADER)) {
 		header = (HEADER*)packet;
 
 		id = ntohs(header->id);
@@ -508,6 +503,8 @@ dnsd_read(int fd, struct query *q, char *buf, int buflen)
 				return decodepacket(name, buf, buflen);
 			}
 		}
+	} else {
+		perror("recvfrom");
 	}
 
 	return 0;