From c92ed9bad821724759619cb00d2bf6ee8d248ddf Mon Sep 17 00:00:00 2001
From: Erik Ekman <yarrick@kryo.se>
Date: Sun, 14 Jun 2009 11:14:40 +0000
Subject: [PATCH] #36 send raw login packet directly to server

---
 src/common.c  |  3 +++
 src/common.h  |  8 +++++++
 src/iodine.c  | 65 +++++++++++++++++++++++++++++++++++++++++++++++----
 src/iodined.c |  4 +++-
 4 files changed, 74 insertions(+), 6 deletions(-)

diff --git a/src/common.c b/src/common.c
index 8511498..2a8380b 100644
--- a/src/common.c
+++ b/src/common.c
@@ -43,6 +43,9 @@
 
 #include "common.h"
 
+/* The raw header used when not using DNS protocol */
+const unsigned char raw_header[RAW_HDR_LEN] = { 0x10, 0xd1, 0x9e, 0x00 };
+
 /* daemon(3) exists only in 4.4BSD or later, and in GNU libc */
 #if !defined(WINDOWS32) && !(defined(BSD) && (BSD >= 199306)) && !defined(__GLIBC__)
 static int daemon(int nochdir, int noclose)
diff --git a/src/common.h b/src/common.h
index f39461a..eb1b39b 100644
--- a/src/common.h
+++ b/src/common.h
@@ -17,6 +17,14 @@
 #ifndef __COMMON_H__
 #define __COMMON_H__
 
+/* Last byte of raw header is the command */
+#define RAW_HDR_LEN 4
+#define RAW_HDR_IDENT_LEN 3
+#define RAW_HDR_CMD 3
+#define RAW_HDR_CMD_LOGIN 0x01
+#define RAW_HDR_CMD_DATA  0x02
+extern const unsigned char raw_header[RAW_HDR_LEN];
+
 #ifdef WINDOWS32
 #include "windows.h"
 #else
diff --git a/src/iodine.c b/src/iodine.c
index c658021..024e080 100644
--- a/src/iodine.c
+++ b/src/iodine.c
@@ -67,6 +67,7 @@ static int running = 1;
 static char password[33];
 
 static struct sockaddr_in nameserv;
+static struct sockaddr_in raw_serv;
 static char *topdomain;
 
 static uint16_t rand_seed;
@@ -120,6 +121,23 @@ send_query(int fd, char *hostname)
 	sendto(fd, packet, len, 0, (struct sockaddr*)&nameserv, sizeof(nameserv));
 }
 
+static void
+send_raw(int fd, char *buf, int buflen, int cmd)
+{
+	unsigned char packet[4096];
+	int len;
+
+	len = MIN(sizeof(packet) - RAW_HDR_LEN, buflen);
+
+	memcpy(packet, raw_header, RAW_HDR_LEN);
+	memcpy(&packet[RAW_HDR_LEN], buf, len);
+
+	len += RAW_HDR_LEN;
+	packet[RAW_HDR_CMD] = cmd;
+
+	sendto(fd, packet, len, 0, (struct sockaddr*)&raw_serv, sizeof(raw_serv));
+}
+
 static void
 send_packet(int fd, char cmd, const char *data, const size_t datalen)
 {
@@ -488,6 +506,16 @@ send_ip_request(int fd, int userid)
 	send_query(fd, buf);
 }
 
+static void
+send_raw_udp_login(int dns_fd, int userid, int seed)
+{
+	char buf[17];
+	login_calculate(buf, 16, password, seed + 1);
+	buf[16] = userid;
+
+	send_raw(dns_fd, buf, sizeof(buf), RAW_HDR_CMD_LOGIN);
+}
+
 static void
 send_case_check(int fd)
 {
@@ -643,7 +671,7 @@ handshake_login(int dns_fd, int seed)
 }
 
 static int
-handshake_raw_udp(int dns_fd)
+handshake_raw_udp(int dns_fd, int seed)
 {
 	struct timeval tv;
 	char in[4096];
@@ -694,9 +722,36 @@ handshake_raw_udp(int dns_fd)
 	fprintf(stderr, " at %s", inet_ntoa(server));
 	fflush(stderr);
 
-	/* TODO do login against port 53 on remote server 
-	 *      based on the old seed. If reply received,
-	 *      switch to raw udp mode */
+	/* Store address to iodined server */
+	memset(&raw_serv, 0, sizeof(raw_serv));
+	raw_serv.sin_family = AF_INET;
+	raw_serv.sin_port = htons(53);
+	raw_serv.sin_addr = server;
+
+	/* do login against port 53 on remote server 
+	 * based on the old seed. If reply received,
+	 * switch to raw udp mode */
+	for (i=0; running && i<4 ;i++) {
+		tv.tv_sec = i + 1;
+		tv.tv_usec = 0;
+
+		send_raw_udp_login(dns_fd, userid, seed);
+		
+		FD_ZERO(&fds);
+		FD_SET(dns_fd, &fds);
+
+		r = select(dns_fd + 1, &fds, NULL, NULL, &tv);
+
+		if(r > 0) {
+			read = read_dns(dns_fd, in, sizeof(in));
+		} else {
+			fprintf(stderr, ".");
+			fflush(stderr);
+		}
+	}
+	
+
+	/* TODO */
 	fprintf(stderr, ": not implemented\n");
 	return 1;
 	/* TODO and then return 0 on success */
@@ -951,7 +1006,7 @@ handshake(int dns_fd, int autodetect_frag_size, int fragsize)
 		return r;
 	}
 
-	handshake_raw_udp(dns_fd);
+	handshake_raw_udp(dns_fd, seed);
 
 	handshake_case_check(dns_fd);
 
diff --git a/src/iodined.c b/src/iodined.c
index 3f06c29..a20066d 100644
--- a/src/iodined.c
+++ b/src/iodined.c
@@ -870,7 +870,9 @@ read_dns(int fd, struct query *q)
 #endif /* !WINDOWS32 */
 
 	if (r > 0) {
-		dns_decode(NULL, 0, q, QR_QUERY, packet, r);
+		if (dns_decode(NULL, 0, q, QR_QUERY, packet, r) < 0) {
+			return 0;
+		}
 		memcpy((struct sockaddr*)&q->from, (struct sockaddr*)&from, addrlen);
 		q->fromlen = addrlen;