#3 major cleanup on client, moved all network code from dns.c to iodine.c

src/common.c

@@ -1,5 +1,4 @@
-/*
+/* Copyright (c) 2006 Bjorn Andersson <flex@kryo.se>, Erik Ekman <yarrick@kryo.se>
- * Copyright (c) 2006 Bjorn Andersson <flex@kryo.se>, Erik Ekman <yarrick@kryo.se>
  *
  * Permission to use, copy, modify, and distribute this software for any
  * purpose with or without fee is hereby granted, provided that the above
@@ -70,3 +69,4 @@ close_dns(int fd)
 {
 	close(fd);
 }
+

src/common.h

@@ -17,6 +17,9 @@
 #ifndef __COMMON_H__
 #define __COMMON_H__
 
+#ifndef MIN
+#define MIN(a,b) ((a)<(b)?(a):(b))
+#endif
 #ifndef MAX
 #define MAX(a,b) ((a)>(b)?(a):(b))
 #endif

src/dns.c

@@ -37,126 +37,18 @@
 #include "encoding.h"
 #include "read.h"
 
-// For FreeBSD
-#ifndef MIN
-#define MIN(a,b) ((a)<(b)?(a):(b))
-#endif
-
-
-static int dns_write(int, int, char *, int, char);
-static void dns_query(int, int, char *, int);
 static int decodepacket(const char*, char*, int);
 
-static struct sockaddr_in peer;
+static char *topdomain;
-static char topdomain[256];
-
-// Current IP packet
-static char activepacket[4096];
-static int lastlen;
-static int packetpos;
-static int packetlen;
-static uint16_t chunkid;
-
-static uint16_t pingid;
 
 
+/* XXX: only used from server, remove! */
 void
 dns_set_topdomain(const char *domain)
 {
-	strncpy(topdomain, domain, sizeof(topdomain) - 1);
+	topdomain = strdup(domain);
-	topdomain[sizeof(topdomain) - 1] = '\0';
 }
 
-int 
-dns_settarget(const char *host) 
-{
-	struct hostent *h;
-
-	// Init dns target struct
-	h = gethostbyname(host);
-	if (!h) {
-		printf("Could not resolve name %s, exiting\n", host);
-		return -1;
-	}
-
-	memset(&peer, 0, sizeof(peer));
-	peer.sin_family = AF_INET;
-	peer.sin_port = htons(53);
-	peer.sin_addr = *((struct in_addr *) h->h_addr);
-
-	// Init chunk id
-	chunkid = 0;
-	pingid = 0;
-
-	return 0;
-}
-
-
-int
-dns_sending()
-{
-	return (packetlen != 0);
-}
-
-static void
-dns_send_chunk(int fd)
-{
-	int avail;
-	char *p;
-
-	p = activepacket;
-	p += packetpos;
-	avail = packetlen - packetpos;
-	lastlen = dns_write(fd, ++chunkid, p, avail, 0);
-}
-
-void
-dns_handle_tun(int fd, char *data, int len)
-{
-	memcpy(activepacket, data, MIN(len, sizeof(activepacket)));
-	lastlen = 0;
-	packetpos = 0;
-	packetlen = len;
-
-	dns_send_chunk(fd);
-}
-
-void
-dns_ping(int dns_fd)
-{
-	char data[2];
-	if (dns_sending()) {
-		lastlen = 0;
-		packetpos = 0;
-		packetlen = 0;
-	}
-	data[0] = (pingid & 0xFF00) >> 8;
-	data[1] = (pingid & 0xFF);
-	dns_write(dns_fd, ++pingid, data, 2, 'P');
-}
-
-void
-dns_login(int dns_fd, char *login, int len)
-{
-	char data[18];
-	memcpy(data, login, MIN(len, 16));
-	data[16] = (pingid & 0xFF00) >> 8;
-	data[17] = (pingid & 0xFF);
-	dns_write(dns_fd, ++pingid, data, 18, 'L');
-}
-
-void 
-dns_send_version(int dns_fd, int version)
-{
-	char data[6];
-	int v;
-
-	v = htonl(version);
-	memcpy(data, &v, 4);
-	data[4] = (pingid & 0xFF00) >> 8;
-	data[5] = (pingid & 0xFF);
-	dns_write(dns_fd, ++pingid, data, 6, 'V');
-}
 
 int
 dns_encode(char *buf, size_t buflen, struct query *q, qr_t qr, char *data, size_t datalen)
@@ -171,7 +63,7 @@ dns_encode(char *buf, size_t buflen, struct query *q, qr_t qr, char *data, size_
 	header = (HEADER*)buf;
 	
 	header->id = htons(q->id);
-	header->qr = qr;
+	header->qr = (qr == QR_ANSWER);
 	header->opcode = 0;
 	header->aa = (qr == QR_ANSWER);
 	header->tc = 0;
@@ -220,9 +112,6 @@ dns_encode(char *buf, size_t buflen, struct query *q, qr_t qr, char *data, size_
 		putshort(&p, 0x8000); // Z
 		putshort(&p, 0x0000); // Data length
 		break;
-	default:
-		errx(1, "dns_encode: qr is wrong!!!");
-		/* NOTREACHED */
 	}
 	
 	len = p - buf;
@@ -250,9 +139,8 @@ dns_decode(char *buf, size_t buflen, struct query *q, qr_t qr, char *packet, siz
 	header = (HEADER*)packet;
 
 	// Reject short packets
-	if (packetlen < sizeof(HEADER)) {
+	if (packetlen < sizeof(HEADER)) 
-		return rv;
+		return 0;
-	}
 	
 	if (header->qr != qr) {
 		warnx("header->qr does not match the requested qr");
@@ -274,6 +162,9 @@ dns_decode(char *buf, size_t buflen, struct query *q, qr_t qr, char *packet, siz
 			return -1;
 		}
 
+		if (q != NULL) 
+			q->id = header->id;
+
 		readname(packet, packetlen, &data, name, sizeof(name));
 		readshort(packet, &data, &type);
 		readshort(packet, &data, &class);
@@ -318,80 +209,28 @@ dns_decode(char *buf, size_t buflen, struct query *q, qr_t qr, char *packet, siz
 	return rv;
 }
 
-static void 
+int
-dns_query(int fd, int id, char *host, int type)
+dns_build_hostname(char *buf, size_t buflen, char *data, size_t datalen, char *topdomain)
-{
-	char buf[1024];
-	struct query q;
-	int peerlen;
-	int len;
-
-	q.id = id;
-	q.type = type;
-	
-	len = dns_encode(buf, sizeof(buf), &q, QR_QUERY, host, strlen(host));
-
-	peerlen = sizeof(peer);
-	sendto(fd, buf, len, 0, (struct sockaddr*)&peer, peerlen);
-}
-
-static int
-dns_write(int fd, int id, char *buf, int len, char flag)
 {
 	int avail;
 	int written;
 	int encoded;
-	char data[257];
+	char *b;
-	char *d;
 
-	avail = 0xFF - strlen(topdomain) - 2;
+	avail = MIN(0xFF, buflen) - strlen(topdomain) - 2;
-	memset(data, 0, sizeof(data));
+	memset(buf, 0, buflen);
-	d = data;
+	b = buf;
-	written = encode_data(buf, len, avail, d, flag);
+	written = encode_data(data, datalen, avail, b);
-	encoded = strlen(data);
+	encoded = strlen(buf);
-	d += encoded;
+	b += encoded;
-	if (*d != '.') {
+	if (*b != '.') {
-		*d++ = '.';
+		*b++ = '.';
 	}
-	strncpy(d, topdomain, strlen(topdomain)+1);
+	strncpy(b, topdomain, strlen(topdomain)+1);
 	
-	dns_query(fd, id, data, T_NULL);
 	return written;
 }
 
-int
-dns_read(int fd, char *buf, int buflen)
-{
-	int r;
-	socklen_t addrlen;
-	char packet[64*1024];
-	struct sockaddr_in from;
-	HEADER *header;
-
-	addrlen = sizeof(struct sockaddr);
-	r = recvfrom(fd, packet, sizeof(packet), 0, (struct sockaddr*)&from, &addrlen);
-	if(r == -1) {
-		perror("recvfrom");
-		return 0;
-	}
-
-	header = (HEADER*)packet;
-	if (dns_sending() && chunkid == ntohs(header->id)) {
-		/* Got ACK on sent packet */
-		packetpos += lastlen;
-		if (packetpos == packetlen) {
-			/* Packet completed */
-			packetpos = 0;
-			packetlen = 0;
-			lastlen = 0;
-		} else {
-			/* More to send */
-			dns_send_chunk(fd);
-		}
-	}
-	return dns_decode(buf, buflen, NULL, QR_ANSWER, packet, r);
-}
-
 int
 dns_encode_hostname(const char *host, char *buffer, int size)
 {
@@ -441,6 +280,7 @@ dnsd_send(int fd, struct query *q, char *data, int datalen)
 static int
 decodepacket(const char *name, char *buf, int buflen)
 {
+	/*
 	int len;
 	char *domain;
 
@@ -450,5 +290,7 @@ decodepacket(const char *name, char *buf, int buflen)
 	if (len == buflen)
 		return -1; 
 	return len;
+	*/
+	return 0;
 }
 

src/dns.h

@@ -24,18 +24,18 @@ typedef enum {
 	QR_ANSWER = 1
 } qr_t;
 
-int dns_settarget(const char*);
 void dns_set_topdomain(const char*);
 
 int dns_sending();
 void dns_handle_tun(int, char *, int);
 void dns_ping(int);
-void dns_send_version(int, int);
 void dns_login(int, char *, int);
 int dns_read(int, char *, int);
 int dns_encode_hostname(const char *, char *, int);
 int dns_encode(char *, size_t, struct query *, qr_t, char *, size_t);
 int dns_decode(char *, size_t, struct query *, qr_t, char *, size_t);
+	
+int dns_build_hostname(char *, size_t, char *, size_t, char *);
 
 void dnsd_send(int, struct query*, char *, int);
 

src/encoding.c

@@ -102,7 +102,7 @@ decode_chunk(char *dest, char *src)
 }
 
 int
-encode_data(char *buf, int len, int space, char *dest, char flag)
+encode_data(char *buf, int len, int space, char *dest)
 {
 	int final;
 	int write;
@@ -127,15 +127,6 @@ encode_data(char *buf, int len, int space, char *dest, char flag)
 	chunks = write / RAW_CHUNK;
 	leftovers = write % RAW_CHUNK;
 
-	// flag is special character to be placed first in the encoded data
-	if (flag != 0) {
-		*dest = flag;
-	} else {
-		// First byte is 0 for middle packet and 1 for last packet
-		*dest = '0' + final;
-	}
-	dest++;
-
 	memset(encoded, 0, sizeof(encoded));
 	ep = encoded;
 	dp = buf;
@@ -182,12 +173,6 @@ decode_data(char *dest, int size, const char *src, char *srcend)
 	char *pp;
 	char *ep;
 
-	// Copy flag
-	len = 1;
-	*dest = *src;
-	dest++;
-	src++;
-
 	memset(encoded, 0, sizeof(encoded));
 	ep = encoded;
 	while(len < size && src < srcend) {

src/encoding.h

@@ -17,7 +17,7 @@
 #ifndef _ENCODING_H_
 #define _ENCODING_H_
 
-int encode_data(char *, int, int, char *, char);
+int encode_data(char *, int, int, char *);
 int decode_data(char *, int, const char *, char *);
 
 #endif /* _ENCODING_H_ */

src/iodine.c

@@ -20,6 +20,7 @@
 #include <string.h>
 #include <signal.h>
 #include <unistd.h>
+#include <netdb.h>
 #include <netinet/in.h>
 #include <sys/types.h>
 #include <sys/socket.h>
@@ -29,6 +30,10 @@
 #include <pwd.h>
 #include <arpa/inet.h>
 #include <zlib.h>
+#include <arpa/nameser.h>
+#ifdef DARWIN
+#include <arpa/nameser8_compat.h>
+#endif
 
 #include "common.h"
 #include "dns.h"
@@ -36,15 +41,99 @@
 #include "tun.h"
 #include "version.h"
 
+static void send_ping(int fd);
+
 int running = 1;
 char password[33];
 
+struct sockaddr_in peer;
+static char *topdomain;
+
+uint16_t rand_seed;
+
+/* Current IP packet */
+static char activepacket[4096];
+static int lastlen;
+static int packetpos;
+static int packetlen;
+static uint16_t chunkid;
+
 static void
 sighandler(int sig) 
 {
 	running = 0;
 }
 
+static void
+dns_send_chunk(int fd)
+{
+	char packet[512];
+	struct query q;
+	char buf[256];
+	int avail;
+	char *p;
+	int len;
+
+	q.id = rand_seed;
+	q.type = T_NULL;
+
+	p = activepacket;
+	p += packetpos;
+	avail = packetlen - packetpos;
+
+	lastlen = dns_build_hostname(buf + 1, sizeof(buf) - 1, p, avail, topdomain);
+	if (lastlen == avail)
+		buf[0] = '1';
+	else 
+		buf[0] = '0';
+		
+	len = dns_encode(packet, sizeof(packet), &q, QR_QUERY, buf, strlen(buf));
+
+	sendto(fd, packet, len, 0, (struct sockaddr*)&peer, sizeof(peer));
+}
+
+int
+dns_sending()
+{
+	return (packetlen != 0);
+}
+
+int
+dns_read(int fd, char *buf, int buflen)
+{
+	struct sockaddr_in from;
+	char packet[64*1024];
+	socklen_t addrlen;
+	struct query q;
+	int rv;
+	int r;
+
+	addrlen = sizeof(struct sockaddr);
+	r = recvfrom(fd, packet, sizeof(packet), 0, (struct sockaddr*)&from, &addrlen);
+	if(r == -1) {
+		perror("recvfrom");
+		return 0;
+	}
+
+	rv = dns_decode(buf, buflen, &q, QR_ANSWER, packet, r);
+
+	if (dns_sending() && chunkid == q.id) {
+		/* Got ACK on sent packet */
+		packetpos += lastlen;
+		if (packetpos == packetlen) {
+			/* Packet completed */
+			packetpos = 0;
+			packetlen = 0;
+			lastlen = 0;
+		} else {
+			/* More to send */
+			dns_send_chunk(fd);
+		}
+	}
+	return rv;
+}
+
+
 static int
 tunnel_tun(int tun_fd, int dns_fd)
 {
@@ -59,7 +148,13 @@ tunnel_tun(int tun_fd, int dns_fd)
 		outlen = sizeof(out);
 		inlen = read;
 		compress2(out, &outlen, in, inlen, 9);
-		dns_handle_tun(dns_fd, out, outlen);
+		
+		memcpy(activepacket, out, MIN(outlen, sizeof(activepacket)));
+		lastlen = 0;
+		packetpos = 0;
+		packetlen = outlen;
+
+		dns_send_chunk(dns_fd);
 	}
 
 	return read;
@@ -82,7 +177,7 @@ tunnel_dns(int tun_fd, int dns_fd)
 
 		write_tun(tun_fd, out, outlen);
 		if (!dns_sending()) 
-			dns_ping(dns_fd);
+			send_ping(dns_fd);
 	}
 	
 	return read;
@@ -115,7 +210,7 @@ tunnel(int tun_fd, int dns_fd)
 		}
 		
 		if (i == 0) /* timeout */
-			dns_ping(dns_fd);
+			send_ping(dns_fd);
 		else {	
 			if(FD_ISSET(tun_fd, &fds)) {
 				if (tunnel_tun(tun_fd, dns_fd) <= 0)
@@ -131,6 +226,91 @@ tunnel(int tun_fd, int dns_fd)
 	return rv;
 }
 
+void
+send_login(int fd, char *login, int len)
+{
+	char packet[512];
+	struct query q;
+	char buf[256];
+	char data[18];
+
+	q.id = rand_seed;
+	q.type = T_NULL;
+
+	memset(data, 0, sizeof(data));
+	memcpy(data, login, MIN(len, 16));
+
+	data[16] = (rand_seed >> 8) & 0xff;
+	data[17] = (rand_seed >> 0) & 0xff;
+	
+	rand_seed++;
+
+	buf[0] = 'L';
+	len = dns_build_hostname(buf + 1, sizeof(buf) - 1, data, sizeof(data), topdomain);
+	len = dns_encode(packet, sizeof(packet), &q, QR_QUERY, buf, strlen(buf));
+
+	sendto(fd, packet, len, 0, (struct sockaddr*)&peer, sizeof(peer));
+}
+
+static void
+send_ping(int fd)
+{
+	
+	char packet[512];
+	struct query q;
+	char buf[256];
+	char data[2];
+	int len;
+	
+	if (dns_sending()) {
+		lastlen = 0;
+		packetpos = 0;
+		packetlen = 0;
+	}
+
+	q.id = rand_seed;
+
+	data[0] = (rand_seed >> 8) & 0xff;
+	data[1] = (rand_seed >> 0) & 0xff;
+	
+	rand_seed++;
+
+	buf[0] = 'P';
+	len = dns_build_hostname(buf + 1, sizeof(buf) - 1, data, sizeof(data), topdomain);
+	len = dns_encode(packet, sizeof(packet), &q, QR_QUERY, buf, strlen(buf));
+
+	sendto(fd, packet, len, 0, (struct sockaddr*)&peer, sizeof(peer));
+}
+
+void 
+send_version(int fd, uint32_t version)
+{
+	char packet[512];
+	struct query q;
+	char buf[256];
+	char data[6];
+	int len;
+
+	q.id = rand_seed;
+	q.type = T_NULL;
+
+	data[0] = (version >> 24) & 0xff;
+	data[1] = (version >> 16) & 0xff;
+	data[2] = (version >> 8) & 0xff;
+	data[3] = (version >> 0) & 0xff;
+
+	data[4] = (rand_seed >> 8) & 0xff;
+	data[5] = (rand_seed >> 0) & 0xff;
+	
+	rand_seed++;
+
+	buf[0] = 'V';
+	len = dns_build_hostname(buf + 1, sizeof(buf) - 1, data, sizeof(data), topdomain);
+	len = dns_encode(packet, sizeof(packet), &q, QR_QUERY, buf, strlen(buf));
+
+	sendto(fd, packet, len, 0, (struct sockaddr*)&peer, sizeof(peer));
+}
+
 static int
 handshake(int dns_fd)
 {
@@ -151,7 +331,7 @@ handshake(int dns_fd)
 		tv.tv_sec = i + 1;
 		tv.tv_usec = 0;
 
-		dns_send_version(dns_fd, VERSION);
+		send_version(dns_fd, VERSION);
 		
 		FD_ZERO(&fds);
 		FD_SET(dns_fd, &fds);
@@ -185,8 +365,9 @@ handshake(int dns_fd)
 			}
 		}
 		
-		if (i == 4)
+		if (i == 4) 
-			return 1;
+			errx(1, "couldn't connect to server");
+		
 		printf("Retrying version check...\n");
 	}
 	
@@ -195,7 +376,7 @@ handshake(int dns_fd)
 		tv.tv_sec = i + 1;
 		tv.tv_usec = 0;
 
-		dns_login(dns_fd, login, 16);
+		send_login(dns_fd, login, 16);
 		
 		FD_ZERO(&fds);
 		FD_SET(dns_fd, &fds);
@@ -237,6 +418,24 @@ handshake(int dns_fd)
 	return 1;
 }
 
+int 
+set_target(const char *host) 
+{
+	struct hostent *h;
+
+	// Init dns target struct
+	if ((h = gethostbyname(host)) <= 0)
+		err(1, "couldn't resovle name %s", host);
+
+	memset(&peer, 0, sizeof(peer));
+	peer.sin_family = AF_INET;
+	peer.sin_port = htons(53);
+	peer.sin_addr = *((struct in_addr *) h->h_addr);
+
+	return 0;
+}
+
+
 static void
 usage() {
 	extern char *__progname;
@@ -330,7 +529,9 @@ main(int argc, char **argv)
 	
 	if (argc != 2) 
 		usage();
-	
+
+	topdomain = strdup(argv[1]);
+
 	if(username) {
 		pw = getpwnam(username);
 		if (!pw) {
@@ -347,10 +548,9 @@ main(int argc, char **argv)
 
 	if ((tun_fd = open_tun(device)) == -1)
 		goto cleanup1;
-	dns_set_topdomain(argv[1]);
 	if ((dns_fd = open_dns(0, INADDR_ANY)) == -1)
 		goto cleanup2;
-	if (dns_settarget(argv[0]) == -1)
+	if (set_target(argv[0]) == -1)
 		goto cleanup2;
 
 	signal(SIGINT, sighandler);

src/iodined.c

@@ -44,6 +44,8 @@ struct packet packetbuf;
 struct packet outpacket;
 int outid;
 
+static char *topdomain;
+
 struct query q;
 
 struct user u;
@@ -383,7 +385,7 @@ main(int argc, char **argv)
 
 	argc -= optind;
 	argv += optind;
-	
+
 	if (geteuid() != 0) {
 		printf("Run as root and you'll be happy.\n");
 		usage();
@@ -392,6 +394,8 @@ main(int argc, char **argv)
 	if (argc != 2) 
 		usage();
 
+	topdomain = strdup(argv[1]);
+
 	if (username) {
 		pw = getpwnam(username);
 		if (!pw) {
@@ -420,7 +424,6 @@ main(int argc, char **argv)
 		goto cleanup0;
 	if (tun_setip(argv[0]) != 0 || tun_setmtu(mtu) != 0)
 		goto cleanup1;
-	dns_set_topdomain(argv[1]);
 	if ((dnsd_fd = open_dns(port, listen_ip)) == -1) 
 		goto cleanup2;