From f9381aa72365a0f9f37c8f708f81959387b2b4fa Mon Sep 17 00:00:00 2001
From: Erik Ekman <yarrick@kryo.se>
Date: Mon, 5 Jun 2006 18:36:34 +0000
Subject: [PATCH] We can send data

---
 dns.c | 52 +++++++++++++++++++++++++++++++++++++++++++++++++---
 dns.h |  3 ++-
 2 files changed, 51 insertions(+), 4 deletions(-)

diff --git a/dns.c b/dns.c
index 6878f84..4a5cd8f 100644
--- a/dns.c
+++ b/dns.c
@@ -140,11 +140,13 @@ close_dns(int fd)
 void
 dns_ping(int dns_fd)
 {
-	dns_query(dns_fd, "4.kryo.se", 1);
+	dns_write(dns_fd, dns_fd, 
+	 "AAAAAAAAAAAKRYOAAAAAAAAAAAKRYOAAAAAAAAAAAAAKRYOAAAAAAAAAAAAAKRYOAAAAAAAAAAAAAAAKRYOAAAAAAAAAAAAAKRYOAAAAAAAAAAAAAAAAAAB",
+	 119);
 }
 
 void 
-dns_query(int fd, char *host, int type)
+dns_query(int fd, int id, char *host, int type)
 {
 	char *p;
 	int len;
@@ -157,7 +159,7 @@ dns_query(int fd, char *host, int type)
 
 	header = (HEADER*)buf;	
 	
-	header->id = 0;
+	header->id = id;
 	header->qr = 0;
 	header->opcode = 0;
 	header->aa = 0;
@@ -179,6 +181,50 @@ dns_query(int fd, char *host, int type)
 	sendto(fd, buf, len+1, 0, (struct sockaddr*)&peer, peerlen);
 }
 
+int
+dns_write(int fd, int id, char *buf, int len)
+{
+	int avail;
+	int i;
+	int parts;
+	int p;
+	char data[256];
+	char *d;
+
+#define CHUNK 31
+// 31 bytes expands to 62 chars in domain
+// We just use hex as encoding right now
+
+	avail = 0xFF - strlen(topdomain) - 2;
+
+	avail /= 2; // use two chars per byte in encoding
+	avail -= (avail/CHUNK); // make space for parts
+
+	avail = MIN(avail, len); // do not use more bytes than is available;
+	d = data;
+
+	parts = avail / CHUNK;
+	for (p = 0; p < parts; p++) {
+		for (i = 0; i < CHUNK; i++) {
+			sprintf(d, "%02X", buf[p*CHUNK + i]);
+			d += 2;
+		}
+		*d++ = '.';
+		strcpy(d, topdomain);
+	}
+	parts = avail % CHUNK;
+	for (i = 0; i < parts; i++) {
+		sprintf(d, "%02X", buf[p*CHUNK + i]);
+		d += 2;
+	}
+	*d++ = '.';
+	strcpy(d, topdomain);
+	
+	printf("Resolving %s\n", data);
+	dns_query(fd, id, data, T_A);
+	return avail;
+}
+
 int
 dns_read(int fd, char *buf, int buflen)
 {
diff --git a/dns.h b/dns.h
index e0c4a64..cb84fc3 100644
--- a/dns.h
+++ b/dns.h
@@ -23,7 +23,8 @@ int open_dns(const char *, const char *);
 void close_dns(int);
 
 void dns_ping(int);
-void dns_query(int, char *, int);
+void dns_query(int, int, char *, int);
+int dns_write(int, int, char *, int);
 int dns_read(int, char *, int);