Cleaned up code and added -Wall to the compiler flags. Moved packet types over to enums for more ease of use.

9 files changed, 110 insertions, 113 deletions

diff --git a/Makefile b/Makefile
index d6e6d7b..ce31dd4 100644
--- a/Makefile
+++ b/Makefile
@@ -15,10 +15,10 @@ install: all
 	chmod 600 $(DESTDIR)/etc/mactelnetd.users
 
 mactelnet: config.h udp.h udp.c mactelnet.c mactelnet.h protocol.c protocol.h console.c console.h devices.c devices.h md5.c md5.h
-	gcc -g -DUSERSFILE='"/etc/mactelnetd.users"' -o mactelnet mactelnet.c udp.c protocol.c console.c devices.c md5.c
+	gcc -Wall -g -DUSERSFILE='"/etc/mactelnetd.users"' -o mactelnet mactelnet.c udp.c protocol.c console.c devices.c md5.c
 
 mactelnetd: config.h mactelnetd.c udp.h udp.c protocol.c protocol.h console.c console.h users.c users.h md5.c md5.h
-	gcc -g -DUSERSFILE='"/etc/mactelnetd.users"' -o mactelnetd mactelnetd.c udp.c protocol.c console.c users.c md5.c
+	gcc -Wall -g -DUSERSFILE='"/etc/mactelnetd.users"' -o mactelnetd mactelnetd.c udp.c protocol.c console.c users.c md5.c
 
 mndp: config.h mndp.c protocol.c protocol.h
-	gcc -g -o mndp mndp.c protocol.c
+	gcc -Wall -g -o mndp mndp.c protocol.c
diff --git a/devices.c b/devices.c
index 9fafdb7..a40ee9d 100644
--- a/devices.c
+++ b/devices.c
@@ -35,7 +35,7 @@
 
 /* Functions using NETDEVICE api */
 
-int getDeviceIndex(int sockfd, unsigned char *deviceName) {
+int getDeviceIndex(int sockfd, char *deviceName) {
 	struct ifreq ifr;
 
 	/* Find interface index from deviceName */
@@ -48,7 +48,7 @@ int getDeviceIndex(int sockfd, unsigned char *deviceName) {
 	return ifr.ifr_ifindex;
 }
 
-int getDeviceMAC(const int sockfd, const unsigned char *deviceName, unsigned char *mac) {
+int getDeviceMAC(const int sockfd, const char *deviceName, unsigned char *mac) {
 	struct ifreq ifr;
 
 	/* Find interface hardware address from deviceName */
@@ -62,7 +62,7 @@ int getDeviceMAC(const int sockfd, const unsigned char *deviceName, unsigned cha
 	return 1;
 }
 
-int getDeviceIp(const int sockfd, const unsigned char *deviceName, struct sockaddr_in *ip) {
+int getDeviceIp(const int sockfd, const char *deviceName, struct sockaddr_in *ip) {
 	struct ifconf ifc;
 	struct ifreq *ifr;
 	int i,numDevices;
@@ -134,11 +134,10 @@ int getIps(char *name, int nameLen, struct sockaddr_in *ip) {
 			int_cursor = int_cursor->ifa_next;
 		}
 	}
-	if (int_cursor == NULL) {
-		if (int_addrs != NULL) {
-			freeifaddrs(int_addrs);
-			int_addrs = NULL;
-		}
-		return 0;
+	if (int_addrs != NULL) {
+		freeifaddrs(int_addrs);
+		int_addrs = NULL;
 	}
+	return 0;
+
 }
diff --git a/devices.h b/devices.h
index ab83821..d917401 100644
--- a/devices.h
+++ b/devices.h
@@ -1,4 +1,4 @@
-extern int getDeviceIndex(int sockfd, unsigned char *deviceName);
-extern int getDeviceMAC(const int sockfd, const unsigned char *deviceName, unsigned char *mac);
-extern int getDeviceIp(const int sockfd, const unsigned char *deviceName, struct sockaddr_in *ip);
+extern int getDeviceIndex(int sockfd, char *deviceName);
+extern int getDeviceMAC(const int sockfd, const char *deviceName, unsigned char *mac);
+extern int getDeviceIp(const int sockfd, const char *deviceName, struct sockaddr_in *ip);
 int getIps(char *name, int nameLen, struct sockaddr_in *ip);
diff --git a/mactelnet.c b/mactelnet.c
index 2c54982..8049ff3 100644
--- a/mactelnet.c
+++ b/mactelnet.c
@@ -60,15 +60,15 @@ int sourceport;
 int connect_timeout = CONNECT_TIMEOUT;
 
 unsigned char encryptionkey[128];
-unsigned char username[255];
-unsigned char password[255];
+char username[255];
+char password[255];
 
 /* Protocol data direction */
 unsigned char mt_direction_fromserver = 0;
 
 unsigned int sendSocket;
 
-int sendUDP(struct mt_packet *packet) {
+static int sendUDP(struct mt_packet *packet) {
 
 	if (broadcastMode) {
 		/* Init SendTo struct */
@@ -84,16 +84,15 @@ int sendUDP(struct mt_packet *packet) {
 
 }
 
-void sendAuthData(unsigned char *username, unsigned char *password) {
+static void sendAuthData(char *username, char *password) {
 	struct mt_packet data;
-	unsigned char *terminal = (unsigned char *)getenv("TERM");
 	unsigned short width = 0;
 	unsigned short height = 0;
-	unsigned char md5data[100];
+	char *terminal = getenv("TERM");
+	char md5data[100];
 	unsigned char md5sum[17];
 	int result;
-	int plen;
-	int databytes;
+	int plen = 0;
 	md5_state_t state;
 
 	/* Concat string of 0 + password + encryptionkey */
@@ -109,8 +108,7 @@ void sendAuthData(unsigned char *username, unsigned char *password) {
 	md5sum[0] = 0;
 
 	/* Send combined packet to server */
-	plen = initPacket(&data, MT_PTYPE_DATA, srcmac, dstmac, sessionkey, outcounter);
-	databytes = plen;
+	 initPacket(&data, MT_PTYPE_DATA, srcmac, dstmac, sessionkey, outcounter);
 	plen += addControlPacket(&data, MT_CPTYPE_PASSWORD, md5sum, 17);
 	plen += addControlPacket(&data, MT_CPTYPE_USERNAME, username, strlen(username));
 	plen += addControlPacket(&data, MT_CPTYPE_TERM_TYPE, terminal, strlen(terminal));
@@ -120,24 +118,23 @@ void sendAuthData(unsigned char *username, unsigned char *password) {
 		plen += addControlPacket(&data, MT_CPTYPE_TERM_HEIGHT, &height, 2);
 	}
 
-	outcounter += plen - databytes;
+	outcounter += plen;
 
 	/* TODO: handle result */
 	result = sendUDP(&data);
 }
 
-void sig_winch(int sig) {
+static void sig_winch(int sig) {
 	unsigned short width,height;
 	struct mt_packet data;
-	int result,plen,databytes;
+	int result,plen;
 
 	/* terminal height/width has changed, inform server */
 	if (getTerminalSize(&width, &height) != -1) {
-		plen = initPacket(&data, MT_PTYPE_DATA, srcmac, dstmac, sessionkey, outcounter);
-		databytes = plen;
-		plen += addControlPacket(&data, MT_CPTYPE_TERM_WIDTH, &width, 2);
+		initPacket(&data, MT_PTYPE_DATA, srcmac, dstmac, sessionkey, outcounter);
+		plen = addControlPacket(&data, MT_CPTYPE_TERM_WIDTH, &width, 2);
 		plen += addControlPacket(&data, MT_CPTYPE_TERM_HEIGHT, &height, 2);
-		outcounter += plen - databytes;
+		outcounter += plen;
 
 		result = sendUDP(&data);
 	}
@@ -146,7 +143,7 @@ void sig_winch(int sig) {
 	signal(SIGWINCH, sig_winch);
 }
 
-void handlePacket(unsigned char *data, int data_len) {
+static void handlePacket(unsigned char *data, int data_len) {
 	struct mt_mactelnet_hdr pkthdr;
 	parsePacket(data, &pkthdr);
 
@@ -159,11 +156,11 @@ void handlePacket(unsigned char *data, int data_len) {
 	if (pkthdr.ptype == MT_PTYPE_DATA) {
 		struct mt_packet odata;
 		struct mt_mactelnet_control_hdr cpkt;
-		int plen=0,result=0;
+		int result=0;
 		int success = 0;
 
 		/* Always transmit ACKNOWLEDGE packets in response to DATA packets */
-		plen = initPacket(&odata, MT_PTYPE_ACK, srcmac, dstmac, sessionkey, pkthdr.counter + (data_len - MT_HEADER_LEN));
+		initPacket(&odata, MT_PTYPE_ACK, srcmac, dstmac, sessionkey, pkthdr.counter + (data_len - MT_HEADER_LEN));
 		result = sendUDP(&odata);
 
 		/* Accept first packet, and all packets greater than incounter, and if counter has
@@ -218,10 +215,10 @@ void handlePacket(unsigned char *data, int data_len) {
 	/* The server wants to terminate the connection, we have to oblige */
 	else if (pkthdr.ptype == MT_PTYPE_END) {
 		struct mt_packet odata;
-		int plen=0,result=0;
+		int result=0;
 
 		/* Acknowledge the disconnection by sending a END packet in return */
-		plen = initPacket(&odata, MT_PTYPE_END, srcmac, dstmac, pkthdr.seskey, 0);
+		initPacket(&odata, MT_PTYPE_END, srcmac, dstmac, pkthdr.seskey, 0);
 		result = sendUDP(&odata);
 
 		fprintf(stderr, "Connection closed.\n");
@@ -233,18 +230,17 @@ void handlePacket(unsigned char *data, int data_len) {
 	}
 }
 
-int findInterface() {
+static int findInterface() {
 	struct mt_packet data;
 	struct sockaddr_in myip;
 	int success;
-	unsigned char devicename[128];
+	char devicename[128];
 	int testsocket;
 	fd_set read_fds;
 	struct timeval timeout;
 	int optval = 1;
-	int i,ii, selected;
 	
-	while (success = getIps(devicename, 128, &myip)) {
+	while ((success = getIps(devicename, 128, &myip))) {
 		char str[INET_ADDRSTRLEN];
 
 		/* Skip loopback interfaces */
@@ -309,11 +305,9 @@ int main (int argc, char **argv) {
 	struct mt_packet data;
 	struct sockaddr_in si_me;
 	unsigned char buff[1500];
-	int plen = 0;
 	struct timeval timeout;
 	int keepalive_counter = 0;
 	fd_set read_fds;
-	unsigned char devicename[30];
 	unsigned char printHelp = 0, haveUsername = 0, havePassword = 0;
 	int c;
 	int optval = 1;
@@ -409,7 +403,7 @@ int main (int argc, char **argv) {
 
 	/* Check for identity name or mac address */
 	{
-		unsigned char *p = argv[optind];
+		char *p = argv[optind];
 		int colons = 0;
 		while (*p++) {
 			if (*p == ':') {
@@ -436,7 +430,6 @@ int main (int argc, char **argv) {
 	}
 
 	if (!haveUsername) {
-		int ret=0;
 		printf("Login: ");
 		scanf("%254s", username);
 	}
@@ -480,7 +473,7 @@ int main (int argc, char **argv) {
 		return 1;
 	}
 
-	if (!findInterface() || recvfrom(insockfd, buff, 1400, 0, 0, 0) < 1) {
+	if (!findInterface() || (result = recvfrom(insockfd, buff, 1400, 0, 0, 0)) < 1) {
 		fprintf(stderr, "Connection failed.\n");
 		return 1;
 	}
@@ -493,9 +486,8 @@ int main (int argc, char **argv) {
 	 * TODO: Should resubmit whenever a PTYPE_DATA packet is sent, and an ACK packet with correct datacounter is received
 	 * or time out the connection, in all other cases.
 	*/
-	plen = initPacket(&data, MT_PTYPE_DATA, srcmac, dstmac, sessionkey, 0);
-	plen = addControlPacket(&data, MT_CPTYPE_BEGINAUTH, NULL, 0);
-	outcounter += plen;
+	initPacket(&data, MT_PTYPE_DATA, srcmac, dstmac, sessionkey, 0);
+	outcounter +=  addControlPacket(&data, MT_CPTYPE_BEGINAUTH, NULL, 0);
 
 	/* TODO: handle result of sendUDP */
 	result = sendUDP(&data);
@@ -526,8 +518,8 @@ int main (int argc, char **argv) {
 
 				datalen = read(STDIN_FILENO, &keydata, 512);
 
-				plen = initPacket(&data, MT_PTYPE_DATA, srcmac, dstmac, sessionkey, outcounter);
-				plen += addControlPacket(&data, MT_CPTYPE_PLAINDATA, &keydata, datalen);
+				initPacket(&data, MT_PTYPE_DATA, srcmac, dstmac, sessionkey, outcounter);
+				addControlPacket(&data, MT_CPTYPE_PLAINDATA, &keydata, datalen);
 				outcounter += datalen;
 				result = sendUDP(&data);
 			}
diff --git a/mactelnetd.c b/mactelnetd.c
index 157c8de..79fa680 100644
--- a/mactelnetd.c
+++ b/mactelnetd.c
@@ -35,6 +35,7 @@
 #include <string.h>
 #include <linux/if_ether.h>
 #include <sys/ioctl.h>
+#include <sys/stat.h>
 #include <pwd.h>
 #include <utmp.h>
 #include <syslog.h>
@@ -81,7 +82,7 @@ struct mt_connection {
 	int pid;
 	int waitForAck;
 
-	unsigned char username[30];
+	char username[30];
 	unsigned char srcip[4];
 	unsigned char srcmac[6];
 	unsigned short srcport;
@@ -89,17 +90,17 @@ struct mt_connection {
 	unsigned char enckey[16];
 	unsigned short terminal_width;
 	unsigned short terminal_height;
-	unsigned char terminal_type[30];
+	char terminal_type[30];
 
 	struct mt_connection *next;
 };
 
-void uwtmp_login(struct mt_connection *);
-void uwtmp_logout(struct mt_connection *);
+static void uwtmp_login(struct mt_connection *);
+static void uwtmp_logout(struct mt_connection *);
 
 struct mt_connection *connections_head = NULL;
 
-void list_addConnection(struct mt_connection *conn) {
+static void list_addConnection(struct mt_connection *conn) {
 	struct mt_connection *p;
 	struct mt_connection *last;
 	if (connections_head == NULL) {
@@ -112,7 +113,7 @@ void list_addConnection(struct mt_connection *conn) {
 	conn->next = NULL;
 }
 
-void list_removeConnection(struct mt_connection *conn) {
+static void list_removeConnection(struct mt_connection *conn) {
 	struct mt_connection *p;
 	struct mt_connection *last;
 	if (connections_head == NULL)
@@ -143,7 +144,7 @@ void list_removeConnection(struct mt_connection *conn) {
 	}
 }
 
-struct mt_connection *list_findConnection(unsigned short seskey, unsigned char *srcmac) {
+static struct mt_connection *list_findConnection(unsigned short seskey, unsigned char *srcmac) {
 	struct mt_connection *p;
 
 	if (connections_head == NULL)
@@ -158,11 +159,11 @@ struct mt_connection *list_findConnection(unsigned short seskey, unsigned char *
 	return NULL;
 }
 
-int sendUDP(const struct mt_connection *conn, const struct mt_packet *data) {
+static int sendUDP(const struct mt_connection *conn, const struct mt_packet *data) {
 	return sendCustomUDP(sockfd, 2, conn->dstmac, conn->srcmac, &sourceip, sourceport, &destip, conn->srcport, data->data, data->size);
 }
 
-void displayMotd() {
+static void displayMotd() {
 	FILE *fp;
 	int c;
 
@@ -174,7 +175,7 @@ void displayMotd() {
 	}
 }
 
-void displayNologin() {
+static void displayNologin() {
 	FILE *fp;
 	int c;
 
@@ -186,7 +187,7 @@ void displayNologin() {
 	}	
 }
 
-void uwtmp_login(struct mt_connection *conn) {
+static void uwtmp_login(struct mt_connection *conn) {
 	struct utmp utent;
 	pid_t pid;
 
@@ -213,7 +214,7 @@ void uwtmp_login(struct mt_connection *conn) {
 	updwtmp(_PATH_WTMP, &utent);
 }
 
-void uwtmp_logout(struct mt_connection *conn) {
+static void uwtmp_logout(struct mt_connection *conn) {
 	if (conn->pid > 0) {
 		struct utmp *utentp;
 		struct utmp utent;
@@ -238,7 +239,7 @@ void uwtmp_logout(struct mt_connection *conn) {
 	}
 }
 
-void abortConnection(struct mt_connection *curconn, struct mt_mactelnet_hdr *pkthdr, char *message) {
+static void abortConnection(struct mt_connection *curconn, struct mt_mactelnet_hdr *pkthdr, char *message) {
 	struct mt_packet pdata;
 	
 	initPacket(&pdata, MT_PTYPE_DATA, pkthdr->dstaddr, pkthdr->srcaddr, pkthdr->seskey, curconn->outcounter);
@@ -251,12 +252,11 @@ void abortConnection(struct mt_connection *curconn, struct mt_mactelnet_hdr *pkt
 	sendUDP(curconn, &pdata);
 }
 
-void userLogin(struct mt_connection *curconn, struct mt_mactelnet_hdr *pkthdr) {
+static void userLogin(struct mt_connection *curconn, struct mt_mactelnet_hdr *pkthdr) {
 	struct mt_packet pdata;
 	unsigned char md5sum[17];
-	unsigned char md5data[100];
+	char md5data[100];
 	struct mt_credentials *user;
-	char shouldDoLogin = 0;
 	char *slavename;
 
 	/* Reparse user file before each login */
@@ -390,7 +390,7 @@ void userLogin(struct mt_connection *curconn, struct mt_mactelnet_hdr *pkthdr) {
 
 }
 
-void handleDataPacket(struct mt_connection *curconn, struct mt_mactelnet_hdr *pkthdr, int data_len) {
+static void handleDataPacket(struct mt_connection *curconn, struct mt_mactelnet_hdr *pkthdr, int data_len) {
 	struct mt_mactelnet_control_hdr cpkt;
 	struct mt_packet pdata;
 	unsigned char *data = pkthdr->data;
@@ -470,14 +470,14 @@ void handleDataPacket(struct mt_connection *curconn, struct mt_mactelnet_hdr *pk
 	}
 }
 
-void terminate() {
+static void terminate() {
 	syslog(LOG_NOTICE, "Exiting.");
 	exit(0);
 }
 
-void handlePacket(unsigned char *data, int data_len, const struct sockaddr_in *address) {
+static void handlePacket(unsigned char *data, int data_len, const struct sockaddr_in *address) {
 	struct mt_mactelnet_hdr pkthdr;
-	struct mt_connection *curconn;
+	struct mt_connection *curconn = NULL;
 	struct mt_packet pdata;
 
 	parsePacket(data, &pkthdr);
@@ -557,16 +557,18 @@ void handlePacket(unsigned char *data, int data_len, const struct sockaddr_in *a
 			handleDataPacket(curconn, &pkthdr, data_len);
 			break;
 		default:
-			syslog(LOG_WARNING, "(%d) Unhandeled packet type: %d", curconn->seskey, pkthdr.ptype);
-			initPacket(&pdata, MT_PTYPE_ACK, pkthdr.dstaddr, pkthdr.srcaddr, pkthdr.seskey, pkthdr.counter);
-			sendUDP(curconn, &pdata);
-	}
+			if (curconn) {
+				syslog(LOG_WARNING, "(%d) Unhandeled packet type: %d", curconn->seskey, pkthdr.ptype);
+				initPacket(&pdata, MT_PTYPE_ACK, pkthdr.dstaddr, pkthdr.srcaddr, pkthdr.seskey, pkthdr.counter);
+				sendUDP(curconn, &pdata);
+			}
+		}
 	if (0 && curconn != NULL) {
 		printf("Packet, incounter %d, outcounter %d\n", curconn->incounter, curconn->outcounter);
 	}
 }
 
-void daemonize() {
+static void daemonize() {
 	int pid,fd;
 
 	pid = fork();
@@ -601,7 +603,6 @@ int main (int argc, char **argv) {
 	int result;
 	struct sockaddr_in si_me;
 	struct timeval timeout;
-	int keepalive_counter = 0;
 	struct mt_packet pdata;
 	fd_set read_fds;
 
@@ -690,7 +691,7 @@ int main (int argc, char **argv) {
 			if (FD_ISSET(insockfd, &read_fds)) {
 				unsigned char buff[1500];
 				struct sockaddr_in saddress;
-				int slen = sizeof(saddress);
+				unsigned int slen = sizeof(saddress);
 				result = recvfrom(insockfd, buff, 1500, 0, (struct sockaddr *)&saddress, &slen);
 				handlePacket(buff, result, &saddress);
 			}
diff --git a/protocol.c b/protocol.c
index ad17910..7202292 100644
--- a/protocol.c
+++ b/protocol.c
@@ -23,6 +23,7 @@
 #include <arpa/inet.h>
 #include <netinet/in.h>
 #include <netinet/ether.h>
+#include <time.h>
 #include "protocol.h"
 #include "config.h"
 
@@ -30,7 +31,7 @@ unsigned char mt_mactelnet_cpmagic[4] = { 0x56, 0x34, 0x12, 0xff };
 unsigned char mt_mactelnet_clienttype[2] = { 0x00, 0x15 };
 
 
-int initPacket(struct mt_packet *packet, unsigned char ptype, unsigned char *srcmac, unsigned char *dstmac, unsigned short sessionkey, unsigned int counter) {
+int initPacket(struct mt_packet *packet, enum mt_ptype ptype, unsigned char *srcmac, unsigned char *dstmac, unsigned short sessionkey, unsigned int counter) {
 	unsigned char *data = packet->data;
 
 	/* Packet version */
@@ -72,7 +73,7 @@ int initPacket(struct mt_packet *packet, unsigned char ptype, unsigned char *src
 	return 22;
 }
 
-int addControlPacket(struct mt_packet *packet, char cptype, void *cpdata, int data_len) {
+int addControlPacket(struct mt_packet *packet, enum mt_cptype cptype, void *cpdata, int data_len) {
 	unsigned char *data = packet->data + packet->size;
 
 	/* Something is really wrong. Packets should never become over 1500 bytes */
@@ -204,7 +205,7 @@ int parseControlPacket(unsigned char *packetdata, int data_len, struct mt_mactel
 	}
 }
 
-struct mt_mndp_packet *parseMNDP(const char *data, const int packetLen) {
+struct mt_mndp_packet *parseMNDP(const unsigned char *data, const int packetLen) {
 	static struct mt_mndp_packet packet;
 	unsigned short nameLen = 0;
 
@@ -232,7 +233,7 @@ struct mt_mndp_packet *parseMNDP(const char *data, const int packetLen) {
 	return &packet;
 }
 
-int queryMNDP(const unsigned char *identity, unsigned char *mac) {
+int queryMNDP(const char *identity, unsigned char *mac) {
 	int fastlookup = 0;
 	int sock, length;
 	int optval = 1;
diff --git a/protocol.h b/protocol.h
index 9068708..72445da 100644
--- a/protocol.h
+++ b/protocol.h
@@ -32,27 +32,31 @@
 #define MT_MNDP_LONGTIMEOUT 120
 
 /* Packet type */
-#define MT_PTYPE_SESSIONSTART 0
-#define MT_PTYPE_DATA 1
-#define MT_PTYPE_ACK 2
-#define MT_PTYPE_END 255
+enum mt_ptype {
+	MT_PTYPE_SESSIONSTART,
+	MT_PTYPE_DATA,
+	MT_PTYPE_ACK,
+	MT_PTYPE_END = 255
+};
 
 /* Control packet type */
-#define MT_CPTYPE_BEGINAUTH 0
-#define MT_CPTYPE_ENCRYPTIONKEY 1
-#define MT_CPTYPE_PASSWORD 2
-#define MT_CPTYPE_USERNAME 3
-#define MT_CPTYPE_TERM_TYPE 4
-#define MT_CPTYPE_TERM_WIDTH 5
-#define MT_CPTYPE_TERM_HEIGHT 6
-#define MT_CPTYPE_PACKET_ERROR 7
-#define MT_CPTYPE_END_AUTH 9
-/* Internal CPTYPE, not part of protocol */
-#define MT_CPTYPE_PLAINDATA -1
+enum mt_cptype {
+	MT_CPTYPE_BEGINAUTH,
+	MT_CPTYPE_ENCRYPTIONKEY,
+	MT_CPTYPE_PASSWORD,
+	MT_CPTYPE_USERNAME,
+	MT_CPTYPE_TERM_TYPE,
+	MT_CPTYPE_TERM_WIDTH,
+	MT_CPTYPE_TERM_HEIGHT,
+	MT_CPTYPE_PACKET_ERROR,
+	MT_CPTYPE_END_AUTH = 9,
+	/* Internal CPTYPE, not part of protocol */
+	MT_CPTYPE_PLAINDATA = -1
+};
 
 struct mt_mactelnet_hdr {
 	unsigned char ver;
-	unsigned char ptype;
+	enum mt_ptype ptype;
 	unsigned int clienttype;
 	unsigned char srcaddr[6];
 	unsigned char dstaddr[6];
@@ -62,7 +66,7 @@ struct mt_mactelnet_hdr {
 };
 
 struct mt_mactelnet_control_hdr {
-	signed char cptype;
+	enum mt_cptype cptype;
 	unsigned int length;
 	unsigned char *data;
 };
@@ -70,7 +74,7 @@ struct mt_mactelnet_control_hdr {
 /* TODO: Add all the other information obtainable from mndp */
 struct mt_mndp_packet {
 	unsigned char address[ETH_ALEN];
-	unsigned char identity[MT_MNDP_MAX_IDENTITY_LENGTH];
+	char identity[MT_MNDP_MAX_IDENTITY_LENGTH];
 };
 
 struct mt_packet {
@@ -79,14 +83,14 @@ struct mt_packet {
 };
 
 /* MacTelnet/Winbox packets */
-extern int initPacket(struct mt_packet *packet, unsigned char ptype, unsigned char *srcmac, unsigned char *dstmac, unsigned short sessionkey, unsigned int counter);
-extern int addControlPacket(struct mt_packet *packet, char cptype, void *cpdata, int data_len);
+extern int initPacket(struct mt_packet *packet, enum mt_ptype ptype, unsigned char *srcmac, unsigned char *dstmac, unsigned short sessionkey, unsigned int counter);
+extern int addControlPacket(struct mt_packet *packet, enum mt_cptype cptype, void *cpdata, int data_len);
 extern void parsePacket(unsigned char *data, struct mt_mactelnet_hdr *pkthdr);
 extern int parseControlPacket(unsigned char *data, int data_len, struct mt_mactelnet_control_hdr *cpkthdr);
 
 /* MNDP packets */
-struct mt_mndp_packet *parseMNDP(const char *data, const int packetLen);
-int queryMNDP(const unsigned char *identity, unsigned char *mac);
+struct mt_mndp_packet *parseMNDP(const unsigned char *data, const int packetLen);
+int queryMNDP(const char *identity, unsigned char *mac);
 
 /* Control packet magic header */
 extern unsigned char mt_mactelnet_cpmagic[4];
diff --git a/users.c b/users.c
index 6ae39c8..1c0bb7d 100644
--- a/users.c
+++ b/users.c
@@ -27,7 +27,7 @@ struct mt_credentials mt_users[MT_CRED_MAXNUM];
 
 void readUserfile() {
 	FILE *file = fopen(USERSFILE, "r");
-	unsigned char line [BUFSIZ];
+	char line [BUFSIZ];
 	int i = 0;
 
 	if (file == NULL) {
@@ -36,11 +36,11 @@ void readUserfile() {
 	}
 
 	while ( fgets(line, sizeof line, file) ) {
-		unsigned char *user;
-		unsigned char *password;
+		char *user;
+		char *password;
 
-		user = (unsigned char *)strtok(line, ":");
-		password = (unsigned char *)strtok(NULL, "\n");
+		user = strtok(line, ":");
+		password = strtok(NULL, "\n");
 
 		if (user == NULL || password == NULL) {
 			continue;
@@ -60,7 +60,7 @@ void readUserfile() {
 	fclose(file);
 }
 
-struct mt_credentials* findUser(unsigned char *username) {
+struct mt_credentials* findUser(char *username) {
 	int i = 0;
 
 	while (i < MT_CRED_MAXNUM && mt_users[i].username[0] != 0) {
diff --git a/users.h b/users.h
index 5f2bf56..a478434 100644
--- a/users.h
+++ b/users.h
@@ -5,13 +5,13 @@
 #define MT_CRED_MAXNUM 128
 
 struct mt_credentials {
-	unsigned char username[MT_CRED_LEN];
-	unsigned char password[MT_CRED_LEN];
+	char username[MT_CRED_LEN];
+	char password[MT_CRED_LEN];
 };
 
 extern struct mt_credentials mt_users[MT_CRED_MAXNUM];
 
 extern void readUserfile();
-struct mt_credentials* findUser(unsigned char *username);
+struct mt_credentials* findUser(char *username);
 
 #endif