project restructured

3 files changed, 863 insertions, 0 deletions

diff --git a/accel-pptpd/ctrl/CMakeLists.txt b/accel-pptpd/ctrl/CMakeLists.txt
new file mode 100644
index 00000000..97f8e0d8
--- /dev/null
+++ b/accel-pptpd/ctrl/CMakeLists.txt
@@ -0,0 +1,4 @@
+INCLUDE_DIRECTORIES(${CMAKE_CURRENT_SOURCE_DIR})
+
+ADD_LIBRARY(pptp SHARED pptp.c)
+
diff --git a/accel-pptpd/ctrl/pptp.c b/accel-pptpd/ctrl/pptp.c
new file mode 100644
index 00000000..b503d85e
--- /dev/null
+++ b/accel-pptpd/ctrl/pptp.c
@@ -0,0 +1,562 @@
+#include <unistd.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <stdarg.h>
+#include <errno.h>
+#include <string.h>
+#include <fcntl.h>
+#include <time.h>
+#include <arpa/inet.h>
+#include <netinet/in.h>
+#include <sys/socket.h>
+
+#include "if_pppox.h"
+
+#include "list.h"
+#include "pptp_prot.h"
+#include "triton.h"
+#include "log.h"
+#include "ppp.h"
+
+
+#define STATE_IDLE 0
+#define STATE_ESTB 1
+#define STATE_PPP  2
+#define STATE_FIN  3
+#define STATE_CLOSE 4
+
+struct pptp_conn_t
+{
+	struct triton_ctx_t ctx;
+	struct triton_md_handler_t hnd;
+	struct triton_timer_t timeout_timer;
+	struct triton_timer_t echo_timer;
+	int state;
+	int echo_sent;
+
+	uint8_t *in_buf;
+	int in_size;
+	uint8_t *out_buf;
+	int out_size;
+	int out_pos;
+
+	struct ppp_ctrl_t ctrl;
+	struct ppp_t ppp;
+};
+
+static int conf_timeout = 3;
+static int conf_echo_interval = 0;
+
+static int pptp_read(struct triton_md_handler_t *h);
+static int pptp_write(struct triton_md_handler_t *h);
+static void pptp_timeout(struct triton_timer_t *);
+static void ppp_started(struct ppp_t *);
+static void ppp_finished(struct ppp_t *);
+
+static void disconnect(struct pptp_conn_t *conn)
+{
+	triton_md_unregister_handler(&conn->hnd);
+	close(conn->hnd.fd);
+	
+	if (conn->timeout_timer.period) {
+		triton_timer_del(&conn->timeout_timer);
+		conn->timeout_timer.period = 0;
+	}
+
+	if (conn->echo_timer.period) {
+		triton_timer_del(&conn->echo_timer);
+		conn->echo_timer.period = 0;
+	}
+
+	if (conn->state == STATE_PPP) {
+		conn->state = STATE_CLOSE;
+		ppp_terminate(&conn->ppp, 1);
+	}
+	
+	triton_unregister_ctx(&conn->ctx);
+	
+	free(conn->in_buf);
+	free(conn->out_buf);
+	free(conn);
+}
+
+static int post_msg(struct pptp_conn_t *conn, void *buf, int size)
+{
+	int n;
+	if (conn->out_size) {
+		log_debug("post_msg: buffer is not empty\n");
+		return -1;
+	}
+
+	n=write(conn->hnd.fd, buf, size);
+	if (n < 0) {
+		if (errno == EINTR || errno == EAGAIN)
+			n = 0;
+		else {
+			if (errno != EPIPE)
+				log_debug("post_msg: failed to write socket %i\n",errno);
+			return -1;
+		}
+	}
+
+	if ( n<size ) {
+		memcpy(conn->out_buf, buf + n, size - n);
+		triton_md_enable_handler(&conn->hnd, MD_MODE_WRITE);
+	}
+
+	return 0;
+}
+
+static int send_pptp_stop_ctrl_conn_rqst(struct pptp_conn_t *conn, int reason, int err_code)
+{
+	struct pptp_stop_ctrl_conn msg = {
+		.header = PPTP_HEADER_CTRL(PPTP_STOP_CTRL_CONN_RQST),
+		.reason_result = hton8(reason),
+		.error_code = hton8(err_code),
+	};
+
+	return post_msg(conn, &msg, sizeof(msg));
+}
+
+static int send_pptp_stop_ctrl_conn_rply(struct pptp_conn_t *conn, int reason, int err_code)
+{
+	struct pptp_stop_ctrl_conn msg = {
+		.header = PPTP_HEADER_CTRL(PPTP_STOP_CTRL_CONN_RPLY),
+		.reason_result = hton8(reason),
+		.error_code = hton8(err_code),
+	};
+
+	return post_msg(conn, &msg, sizeof(msg));
+}
+static int pptp_stop_ctrl_conn_rqst(struct pptp_conn_t *conn)
+{
+	struct pptp_stop_ctrl_conn *msg = (struct pptp_stop_ctrl_conn *)conn->in_buf;
+	log_info("PPTP_STOP_CTRL_CONN_RQST reason=%i error_code=%i\n",msg->reason_result, msg->error_code);
+
+	if (conn->state == STATE_PPP) {
+		conn->state = STATE_FIN;
+		ppp_terminate(&conn->ppp, 0);
+	}
+
+	send_pptp_stop_ctrl_conn_rply(conn, PPTP_CONN_STOP_OK, 0);
+	return -1;
+}
+
+static int send_pptp_start_ctrl_conn_rply(struct pptp_conn_t *conn, int res_code, int err_code)
+{
+	struct pptp_start_ctrl_conn msg = {
+		.header = PPTP_HEADER_CTRL(PPTP_START_CTRL_CONN_RPLY),
+		.version = htons(PPTP_VERSION),
+		.result_code = res_code,
+		.error_code = err_code,
+		.framing_cap = htonl(PPTP_FRAME_SYNC),
+		.bearer_cap = htonl(0),
+		.max_channels = htons(1),
+		.firmware_rev = htons(PPTP_FIRMWARE_VERSION),
+	};
+
+	memset(msg.hostname, 0, sizeof(msg.hostname));
+	strcpy((char*)msg.hostname, PPTP_HOSTNAME);
+
+	memset(msg.vendor, 0, sizeof(msg.vendor));
+	strcpy((char*)msg.vendor, PPTP_VENDOR);
+
+	return post_msg(conn, &msg, sizeof(msg));
+}
+static int pptp_start_ctrl_conn_rqst(struct pptp_conn_t *conn)
+{
+	struct pptp_start_ctrl_conn *msg = (struct pptp_start_ctrl_conn *)conn->in_buf;
+
+	if (conn->state != STATE_IDLE) {
+		log_info("unexpected PPTP_START_CTRL_CONN_RQST\n");
+		if (send_pptp_start_ctrl_conn_rply(conn, PPTP_CONN_RES_EXISTS, 0))
+			return -1;
+		return 0;
+	}
+
+	if (msg->version != htons(PPTP_VERSION)) {
+		log_info("PPTP version mismatch: expecting %x, received %s\n", PPTP_VERSION, msg->version);
+		if (send_pptp_start_ctrl_conn_rply(conn, PPTP_CONN_RES_PROTOCOL, 0))
+			return -1;
+		return 0;
+	}
+	if (!(ntohl(msg->framing_cap) & PPTP_FRAME_SYNC)) {
+		log_info("connection does not supports sync mode\n");
+		if (send_pptp_start_ctrl_conn_rply(conn, PPTP_CONN_RES_GE, 0))
+			return -1;
+		return 0;
+	}
+	if (send_pptp_start_ctrl_conn_rply(conn, PPTP_CONN_RES_SUCCESS, 0))
+		return -1;
+
+	triton_timer_mod(&conn->timeout_timer, 0);
+
+	conn->state = STATE_ESTB;
+
+	return 0;
+}
+
+static int send_pptp_out_call_rply(struct pptp_conn_t *conn, struct pptp_out_call_rqst *rqst, int call_id, int res_code, int err_code)
+{
+	struct pptp_out_call_rply msg = {
+		.header = PPTP_HEADER_CTRL(PPTP_OUT_CALL_RPLY),
+		.call_id = htons(call_id),
+		.call_id_peer = rqst->call_id,
+		.result_code = res_code,
+		.error_code = err_code,
+		.cause_code = 0,
+		.speed = rqst->bps_max,
+		.recv_size = rqst->recv_size,
+		.delay = 0,
+		.channel = 0,
+	};
+
+	return post_msg(conn, &msg, sizeof(msg));
+}
+
+static int pptp_out_call_rqst(struct pptp_conn_t *conn)
+{
+	struct pptp_out_call_rqst *msg = (struct pptp_out_call_rqst *)conn->in_buf;
+	struct sockaddr_pppox src_addr, dst_addr;
+  struct sockaddr_in addr;
+	socklen_t addrlen;
+	int pptp_sock;
+
+	if (conn->state != STATE_ESTB) {
+		log_error("unexpected PPTP_OUT_CALL_RQST\n");
+		if (send_pptp_out_call_rply(conn, msg, 0, PPTP_CALL_RES_GE, PPTP_GE_NOCONN))
+			return -1;
+		return 0;
+	}
+
+	src_addr.sa_family = AF_PPPOX;
+	src_addr.sa_protocol = PX_PROTO_PPTP;
+	src_addr.sa_addr.pptp.call_id = 0;
+	addrlen = sizeof(addr);
+	getsockname(conn->hnd.fd, (struct sockaddr*)&addr, &addrlen);
+	src_addr.sa_addr.pptp.sin_addr = addr.sin_addr;
+
+	dst_addr.sa_family = AF_PPPOX;
+	dst_addr.sa_protocol = PX_PROTO_PPTP;
+	dst_addr.sa_addr.pptp.call_id = htons(msg->call_id);
+	addrlen = sizeof(addr);
+	getpeername(conn->hnd.fd, (struct sockaddr*)&addr, &addrlen);
+	dst_addr.sa_addr.pptp.sin_addr = addr.sin_addr;
+
+	pptp_sock = socket(AF_PPPOX, SOCK_STREAM, PX_PROTO_PPTP);
+	if (pptp_sock < 0) {
+		log_error("failed to create PPTP socket (%s)\n", strerror(errno));
+		return -1;
+	}
+	if (bind(pptp_sock, (struct sockaddr*)&src_addr, sizeof(src_addr))) {
+		log_error("failed to bind PPTP socket (%s)\n", strerror(errno));
+		close(pptp_sock);
+		return -1;
+	}
+	addrlen = sizeof(src_addr);
+	getsockname(pptp_sock, (struct sockaddr*)&src_addr, &addrlen);
+
+	if (connect(pptp_sock, (struct sockaddr*)&dst_addr, sizeof(dst_addr))) {
+		log_error("failed to connect PPTP socket (%s)\n", strerror(errno));
+		close(pptp_sock);
+		return -1;
+	}
+
+	if (send_pptp_out_call_rply(conn, msg, src_addr.sa_addr.pptp.call_id, PPTP_CALL_RES_OK, 0))
+		return -1;
+
+	conn->ppp.fd = pptp_sock;
+	conn->ppp.chan_name = strdup(inet_ntoa(dst_addr.sa_addr.pptp.sin_addr));
+	conn->ppp.ctrl = &conn->ctrl;
+	conn->ctrl.ctx = &conn->ctx;
+	conn->ctrl.started = ppp_started;
+	conn->ctrl.finished = ppp_finished;
+	if (establish_ppp(&conn->ppp)) {
+		close(pptp_sock);
+		//if (send_pptp_stop_ctrl_conn_rqst(conn, 0, 0))
+		conn->state = STATE_FIN;
+		return -1;
+	}
+	conn->state = STATE_PPP;
+	
+	triton_timer_del(&conn->timeout_timer);
+	conn->timeout_timer.period = 0;
+
+	if (conf_echo_interval) {
+		conn->echo_timer.period = conf_echo_interval * 1000;
+		triton_timer_add(&conn->ctx, &conn->echo_timer, 0);
+	}
+
+	return 0;
+}
+
+static int pptp_echo_rqst(struct pptp_conn_t *conn)
+{
+	struct pptp_echo_rqst *in_msg = (struct pptp_echo_rqst *)conn->in_buf;
+	struct pptp_echo_rply out_msg = {
+		.header = PPTP_HEADER_CTRL(PPTP_ECHO_RQST),
+		.identifier = in_msg->identifier,
+		.result_code = 1,
+	};
+
+	return post_msg(conn, &out_msg, sizeof(out_msg));
+}
+
+static int pptp_echo_rply(struct pptp_conn_t *conn)
+{
+	struct pptp_echo_rply *msg = (struct pptp_echo_rply *)conn->in_buf;
+	if (msg->identifier != conn->echo_sent) {
+		log_error("pptp:echo: identifier mismatch\n");
+		return -1;
+	}
+	conn->echo_sent = 0;
+	return 0;
+}
+static void pptp_send_echo(struct triton_timer_t *t)
+{
+	struct pptp_conn_t *conn = container_of(t, typeof(*conn), echo_timer);
+	struct pptp_echo_rqst msg = {
+		.header = PPTP_HEADER_CTRL(PPTP_ECHO_RQST),
+	};
+
+	if (conn->echo_sent) {
+		log_warn("pptp: no echo reply\n");
+		disconnect(conn);
+		return;
+	}
+
+	conn->echo_sent = random();
+	msg.identifier = conn->echo_sent;
+
+	if (post_msg(conn, &msg, sizeof(msg)))
+		disconnect(conn);
+}
+
+static int process_packet(struct pptp_conn_t *conn)
+{
+	struct pptp_header *hdr = (struct pptp_header *)conn->in_buf;
+	switch(ntohs(hdr->ctrl_type))
+	{
+		case PPTP_START_CTRL_CONN_RQST:
+			return pptp_start_ctrl_conn_rqst(conn);
+		case PPTP_STOP_CTRL_CONN_RQST:
+			return pptp_stop_ctrl_conn_rqst(conn);
+		case PPTP_OUT_CALL_RQST:
+			return pptp_out_call_rqst(conn);
+		case PPTP_ECHO_RQST:
+			return pptp_echo_rqst(conn);
+		case PPTP_ECHO_RPLY:
+			return pptp_echo_rply(conn);
+	}
+	return 0;
+}
+
+static int pptp_read(struct triton_md_handler_t *h)
+{
+	struct pptp_conn_t *conn=container_of(h,typeof(*conn),hnd);
+	struct pptp_header *hdr=(struct pptp_header *)conn->in_buf;
+	int n;
+
+	while(1) {
+		n = read(h->fd,conn->in_buf,PPTP_CTRL_SIZE_MAX-conn->in_size);
+		if (n < 0) {
+			if (errno == EINTR)
+				continue;
+			if (errno == EAGAIN)
+				return 0;
+			log_error("pptp: read: %s\n",strerror(errno));
+			goto drop;
+		}
+		if (n == 0)
+			goto drop;
+		conn->in_size += n;
+		if (conn->in_size >= sizeof(*hdr)) {
+			if (hdr->magic != htonl(PPTP_MAGIC))
+				goto drop;
+			if (ntohs(hdr->length) >= PPTP_CTRL_SIZE_MAX)
+				goto drop;
+			if (ntohs(hdr->length) > conn->in_size)
+				goto drop;
+			if (ntohs(hdr->length) == conn->in_size) {
+				if (ntohs(hdr->length) != PPTP_CTRL_SIZE(ntohs(hdr->ctrl_type)))
+					goto drop;
+				if (process_packet(conn))
+					goto drop;
+				conn->in_size = 0;
+			}
+		}
+	}
+drop:
+	disconnect(conn);
+	return 1;
+}
+static int pptp_write(struct triton_md_handler_t *h)
+{
+	struct pptp_conn_t *conn = container_of(h, typeof(*conn), hnd);
+	int n;
+
+	while (1) {
+		n = write(h->fd, conn->out_buf+conn->out_pos, conn->out_size-conn->out_pos);
+
+		if (n < 0) {
+			if (errno == EINTR)
+				continue;
+			if (errno == EAGAIN)
+				n = 0;
+			else {
+				if (errno != EPIPE)
+					log_error("pptp:post_msg: %s\n", strerror(errno));
+				disconnect(conn);
+				return 1;
+			}
+		}
+
+		conn->out_pos += n;
+		if (conn->out_pos == conn->out_size) {
+			conn->out_pos = 0;
+			conn->out_size = 0;
+			triton_md_disable_handler(h, MD_MODE_WRITE);
+			return 0;
+		}
+	}
+}
+static void pptp_timeout(struct triton_timer_t *t)
+{
+	struct pptp_conn_t *conn = container_of(t, typeof(*conn), timeout_timer);
+	disconnect(conn);
+}
+static void pptp_close(struct triton_ctx_t *ctx)
+{
+	struct pptp_conn_t *conn = container_of(ctx, typeof(*conn), ctx);
+	if (conn->state == STATE_PPP) {
+		conn->state = STATE_FIN;
+		ppp_terminate(&conn->ppp, 0);
+	} else
+		disconnect(conn);
+}
+static void ppp_started(struct ppp_t *ppp)
+{
+	log_msg("ppp_started\n");
+}
+static void ppp_finished(struct ppp_t *ppp)
+{
+	struct pptp_conn_t *conn = container_of(ppp, typeof(*conn), ppp);
+
+	log_msg("ppp_finished\n");
+	close(conn->ppp.fd);
+	//send_pptp_stop_ctrl_conn_rqst(conn, 0, 0);
+	if (conn->state != STATE_CLOSE) {
+		conn->state = STATE_CLOSE;
+		disconnect(conn);
+	}
+}
+
+//==================================
+
+struct pptp_serv_t
+{
+	struct triton_ctx_t ctx;
+	struct triton_md_handler_t hnd;
+};
+
+static int pptp_connect(struct triton_md_handler_t *h)
+{
+  struct sockaddr_in addr;
+	socklen_t size = sizeof(addr);
+	int sock;
+	struct pptp_conn_t *conn;
+
+	while(1) {
+		sock = accept(h->fd, (struct sockaddr *)&addr, &size);
+		if (sock < 0) {
+			if (errno == EAGAIN)
+				return 0;
+			log_error("pptp: accept failed: %s\n", strerror(errno));
+			continue;
+		}
+
+		log_info("pptp: new connection from %s\n", inet_ntoa(addr.sin_addr));
+
+		if (fcntl(sock, F_SETFL, O_NONBLOCK)) {
+			log_error("pptp: failed to set nonblocking mode: %s, closing connection...\n", strerror(errno));
+			close(sock);
+			continue;
+		}
+
+		conn = malloc(sizeof(*conn));
+		memset(conn, 0, sizeof(*conn));
+		conn->hnd.fd = sock;
+		conn->hnd.read = pptp_read;
+		conn->hnd.write = pptp_write;
+		conn->ctx.close = pptp_close;
+		conn->in_buf = malloc(PPTP_CTRL_SIZE_MAX);
+		conn->out_buf = malloc(PPTP_CTRL_SIZE_MAX);
+		conn->timeout_timer.expire = pptp_timeout;
+		conn->timeout_timer.period = conf_timeout * 1000;
+		conn->echo_timer.expire = pptp_send_echo;
+
+		triton_register_ctx(&conn->ctx);
+		triton_md_register_handler(&conn->ctx, &conn->hnd);
+		triton_md_enable_handler(&conn->hnd,MD_MODE_READ);
+		triton_timer_add(&conn->ctx, &conn->timeout_timer, 0);
+	}
+	return 0;
+}
+static void pptp_serv_close(struct triton_ctx_t *ctx)
+{
+	struct pptp_serv_t *s=container_of(ctx,typeof(*s),ctx);
+	triton_md_unregister_handler(&s->hnd);
+	close(s->hnd.fd);
+}
+
+static struct pptp_serv_t serv=
+{
+	.hnd.read=pptp_connect,
+	.ctx.close=pptp_serv_close,
+};
+
+static void __init pptp_init(void)
+{
+  struct sockaddr_in addr;
+	char *opt;
+	
+	serv.hnd.fd = socket (PF_INET, SOCK_STREAM, 0);
+  if (serv.hnd.fd < 0) {
+    log_error("pptp: failed to create server socket: %s\n", strerror(errno));
+    return;
+  }
+  addr.sin_family = AF_INET;
+  addr.sin_port = htons (PPTP_PORT);
+  addr.sin_addr.s_addr = htonl (INADDR_ANY);
+  if (bind (serv.hnd.fd, (struct sockaddr *) &addr, sizeof (addr)) < 0) {
+  	perror("pptp: bind");
+    log_error("pptp: failed to bind socket: %s\n", strerror(errno));
+		close(serv.hnd.fd);
+    return;
+  }
+
+  if (listen (serv.hnd.fd, 100) < 0) {
+    log_error("pptp: failed to listen socket: %s\n", strerror(errno));
+		close(serv.hnd.fd);
+    return;
+  }
+
+	if (fcntl(serv.hnd.fd, F_SETFL, O_NONBLOCK)) {
+    log_error("pptp: failed to set nonblocking mode: %s\n", strerror(errno));
+		close(serv.hnd.fd);
+    return;
+	}
+	
+	triton_register_ctx(&serv.ctx);
+	triton_md_register_handler(&serv.ctx, &serv.hnd);
+	triton_md_enable_handler(&serv.hnd, MD_MODE_READ);
+
+	opt = conf_get_opt("pptp", "timeout");
+	if (opt && atoi(opt) > 0)
+		conf_timeout = atoi(opt);
+	
+	opt = conf_get_opt("pptp", "echo-interval");
+	if (opt && atoi(opt) > 0)
+		conf_echo_interval = atoi(opt);
+}
+
diff --git a/accel-pptpd/ctrl/pptp_prot.h b/accel-pptpd/ctrl/pptp_prot.h
new file mode 100644
index 00000000..7e3ebdd4
--- /dev/null
+++ b/accel-pptpd/ctrl/pptp_prot.h
@@ -0,0 +1,297 @@
+#ifndef PPTP_PROT_H
+#define PPTP_PROT_H
+
+#include <sys/types.h>
+
+#define hton8(x)  (x)
+#define ntoh8(x)  (x)
+#define hton16(x) htons(x)
+#define ntoh16(x) ntohs(x)
+#define hton32(x) htonl(x)
+#define ntoh32(x) ntohl(x)
+
+/* PPTP magic numbers: ----------------------------------------- */
+
+#define PPTP_MAGIC 0x1A2B3C4D /* Magic cookie for PPTP datagrams */
+#define PPTP_PORT  1723       /* PPTP TCP port number            */
+#define PPTP_PROTO 47         /* PPTP IP protocol number         */
+
+/* PPTP result codes:---------------------------------------- */
+#define PPTP_CONN_RES_SUCCESS 1
+#define PPTP_CONN_RES_GE      2
+#define PPTP_CONN_RES_EXISTS  3
+#define PPTP_CONN_RES_AUTH 	  4
+#define PPTP_CONN_RES_PROTOCOL 5
+
+#define PPTP_CONN_STOP_OK     1
+#define PPTP_CONN_STOP_GE     2
+
+#define PPTP_CALL_RES_OK	    1
+#define PPTP_CALL_RES_GE	    2
+
+#define PPTP_GE_NOCONN				1
+
+/* Control Connection Message Types: --------------------------- */
+
+#define PPTP_MESSAGE_CONTROL	1
+#define PPTP_MESSAGE_MANAGE		2
+
+/* Control Message Types: -------------------------------------- */
+
+/* (Control Connection Management) */
+#define PPTP_START_CTRL_CONN_RQST	1
+#define PPTP_START_CTRL_CONN_RPLY	2
+#define PPTP_STOP_CTRL_CONN_RQST	3
+#define PPTP_STOP_CTRL_CONN_RPLY	4
+#define PPTP_ECHO_RQST					5
+#define PPTP_ECHO_RPLY					6
+
+/* (Call Management) */
+#define PPTP_OUT_CALL_RQST			7
+#define PPTP_OUT_CALL_RPLY			8
+#define PPTP_IN_CALL_RQST				9
+#define PPTP_IN_CALL_RPLY				10
+#define PPTP_IN_CALL_CONNECT		11
+#define PPTP_CALL_CLEAR_RQST		12
+#define PPTP_CALL_CLEAR_NTFY		13
+
+/* (Error Reporting) */
+#define PPTP_WAN_ERR_NTFY				14
+
+/* (PPP Session Control) */
+#define PPTP_SET_LINK_INFO			15
+
+/* PPTP version information: --------------------------------------*/
+#define PPTP_VERSION_STRING			"1.00"
+#define PPTP_VERSION						0x100
+#define PPTP_FIRMWARE_STRING		"0.01"
+#define PPTP_FIRMWARE_VERSION		0x001
+
+#define PPTP_HOSTNAME "local"
+#define PPTP_VENDOR   "cananian"
+
+/* PPTP capabilities: ---------------------------------------------*/
+
+/* (Framing capabilities for msg sender) */
+#define PPTP_FRAME_ASYNC				1
+#define PPTP_FRAME_SYNC					2
+#define PPTP_FRAME_ANY          3
+
+/* (Bearer capabilities for msg sender) */
+#define PPTP_BEARER_ANALOG			1
+#define PPTP_BEARER_DIGITAL 		2
+#define PPTP_BEARER_ANY					3
+
+#define PPTP_RESULT_GENERAL_ERROR 2
+
+/* (Reasons to close a connection) */
+#define PPTP_STOP_NONE		  		1 /* no good reason                        */
+#define PPTP_STOP_PROTOCOL	  	2 /* can't support peer's protocol version */
+#define PPTP_STOP_LOCAL_SHUTDOWN  3 /* requester is being shut down          */
+
+/* PPTP datagram structures (all data in network byte order): ----------*/
+
+struct pptp_header
+{
+  uint16_t length;	  		/* message length in octets, including header */
+  uint16_t pptp_type;	  /* PPTP message type. 1 for control message.  */
+  uint32_t magic;	  		/* this should be PPTP_MAGIC.                 */
+  uint16_t ctrl_type;	  /* Control message type (0-15)                */
+  uint16_t reserved0;	  /* reserved.  MUST BE ZERO.                   */
+}__attribute__((packed));
+
+struct pptp_start_ctrl_conn /* for control message types 1 and 2 */
+{
+  struct pptp_header header;
+
+  uint16_t version;      /* PPTP protocol version.  = PPTP_VERSION     */
+  uint8_t  result_code;    /* these two fields should be zero on rqst msg*/
+  uint8_t  error_code;   /* 0 unless result_code==2 (General Error)    */
+  uint32_t framing_cap;  /* Framing capabilities                       */
+  uint32_t bearer_cap;   /* Bearer Capabilities                        */
+  uint16_t max_channels; /* Maximum Channels (=0 for PNS, PAC ignores) */
+  uint16_t firmware_rev; /* Firmware or Software Revision              */
+  uint8_t  hostname[64]; /* Host Name (64 octets, zero terminated)     */
+  uint8_t  vendor[64];   /* Vendor string (64 octets, zero term.)      */
+}__attribute__((packed));
+
+struct pptp_stop_ctrl_conn /* for control message types 3 and 4 */
+{
+  struct pptp_header header;
+
+  uint8_t reason_result; /* reason for rqst, result for rply          */
+  uint8_t error_code;	  /* MUST be 0, unless rply result==2 (general err)*/
+  uint16_t reserved1;    /* MUST be 0                                */
+}__attribute__((packed));
+
+struct pptp_echo_rqst /* for control message type 5 */
+{
+  struct pptp_header header;
+  uint32_t identifier;   /* arbitrary value set by sender which is used */
+                          /* to match up reply and request               */
+}__attribute__((packed));
+
+struct pptp_echo_rply /* for control message type 6 */
+{
+  struct pptp_header header;
+  uint32_t identifier;	  /* should correspond to id of rqst             */
+  uint8_t result_code;
+  uint8_t error_code;    /* =0, unless result_code==2 (general error)   */
+  uint16_t reserved1;    /* MUST BE ZERO                                */
+}__attribute__((packed));
+
+struct pptp_out_call_rqst /* for control message type 7 */
+{
+  struct pptp_header header;
+  uint16_t call_id;	  /* Call ID (unique id used to multiplex data)  */
+  uint16_t call_sernum;  /* Call Serial Number (used for logging)       */
+  uint32_t bps_min;      /* Minimum BPS (lowest acceptable line speed)  */
+  uint32_t bps_max;	  /* Maximum BPS (highest acceptable line speed) */
+  uint32_t bearer;	  /* Bearer type                                 */
+  uint32_t framing;      /* Framing type                                */
+  uint16_t recv_size;	  /* Recv. Window Size (no. of buffered packets) */
+  uint16_t delay;	  /* Packet Processing Delay (in 1/10 sec)       */
+  uint16_t phone_len;	  /* Phone Number Length (num. of valid digits)  */
+  uint16_t reserved1;    /* MUST BE ZERO				 */
+  uint8_t  phone_num[64]; /* Phone Number (64 octets, null term.)       */
+  uint8_t subaddress[64]; /* Subaddress (64 octets, null term.)         */
+}__attribute__((packed));
+
+struct pptp_out_call_rply /* for control message type 8 */
+{
+  struct pptp_header header;
+  uint16_t call_id;      /* Call ID (used to multiplex data over tunnel)*/
+  uint16_t call_id_peer; /* Peer's Call ID (call_id of pptp_out_call_rqst)*/
+  uint8_t  result_code;  /* Result Code (1 is no errors)                */
+  uint8_t  error_code;   /* Error Code (=0 unless result_code==2)       */
+  uint16_t cause_code;   /* Cause Code (addt'l failure information)     */
+  uint32_t speed;        /* Connect Speed (in BPS)                      */
+  uint16_t recv_size;    /* Recv. Window Size (no. of buffered packets) */
+  uint16_t delay;	  /* Packet Processing Delay (in 1/10 sec)       */
+  uint32_t channel;      /* Physical Channel ID (for logging)           */
+}__attribute__((packed));
+
+struct pptp_in_call_rqst /* for control message type 9 */
+{
+  struct pptp_header header;
+  uint16_t call_id;	  /* Call ID (unique id used to multiplex data)  */
+  uint16_t call_sernum;  /* Call Serial Number (used for logging)       */
+  uint32_t bearer;	  /* Bearer type                                 */
+  uint32_t channel;      /* Physical Channel ID (for logging)           */
+  uint16_t dialed_len;   /* Dialed Number Length (# of valid digits)    */
+  uint16_t dialing_len;  /* Dialing Number Length (# of valid digits)   */
+  uint8_t dialed_num[64]; /* Dialed Number (64 octets, zero term.)      */
+  uint8_t dialing_num[64]; /* Dialing Number (64 octets, zero term.)    */
+  uint8_t subaddress[64];  /* Subaddress (64 octets, zero term.)        */
+}__attribute__((packed));
+
+struct pptp_in_call_rply /* for control message type 10 */
+{
+  struct pptp_header header;
+  uint16_t call_id;      /* Call ID (used to multiplex data over tunnel)*/
+  uint16_t call_id_peer; /* Peer's Call ID (call_id of pptp_out_call_rqst)*/
+  uint8_t  result_code;  /* Result Code (1 is no errors)                */
+  uint8_t  error_code;   /* Error Code (=0 unless result_code==2)       */
+  uint16_t recv_size;    /* Recv. Window Size (no. of buffered packets) */
+  uint16_t delay;	  /* Packet Processing Delay (in 1/10 sec)       */
+  uint16_t reserved1;    /* MUST BE ZERO                                */
+}__attribute__((packed));
+
+struct pptp_in_call_connect /* for control message type 11 */
+{
+  struct pptp_header header;
+  uint16_t call_id_peer; /* Peer's Call ID (call_id of pptp_out_call_rqst)*/
+  uint16_t reserved1;    /* MUST BE ZERO                                */
+  uint32_t speed;        /* Connect Speed (in BPS)                      */
+  uint16_t recv_size;    /* Recv. Window Size (no. of buffered packets) */
+  uint16_t delay;	  /* Packet Processing Delay (in 1/10 sec)       */
+  uint32_t framing;      /* Framing type                                */
+}__attribute__((packed));
+
+struct pptp_call_clear_rqst /* for control message type 12 */
+{
+  struct pptp_header header;
+  uint16_t call_id;      /* Call ID (used to multiplex data over tunnel)*/
+  uint16_t reserved1;    /* MUST BE ZERO                                */
+}__attribute__((packed));
+
+struct pptp_call_clear_ntfy /* for control message type 13 */
+{
+  struct pptp_header header;
+  uint16_t call_id;      /* Call ID (used to multiplex data over tunnel)*/
+  uint8_t  result_code;  /* Result Code                                 */
+  uint8_t  error_code;   /* Error Code (=0 unless result_code==2)       */
+  uint16_t cause_code;   /* Cause Code (for ISDN, is Q.931 cause code)  */
+  uint16_t reserved1;    /* MUST BE ZERO                                */
+  uint8_t call_stats[128]; /* Call Statistics: 128 octets, ascii, 0-term */
+}__attribute__((packed));
+
+struct pptp_wan_err_ntfy  /* for control message type 14 */
+{
+  struct pptp_header header;
+  uint16_t call_id_peer; /* Peer's Call ID (call_id of pptp_out_call_rqst)*/
+  uint16_t reserved1;    /* MUST BE ZERO                                */
+  uint32_t crc_errors;   /* CRC errors 				 */
+  uint32_t frame_errors; /* Framing errors 				 */
+  uint32_t hard_errors;  /* Hardware overruns 				 */
+  uint32_t buff_errors;  /* Buffer overruns				 */
+  uint32_t time_errors;  /* Time-out errors				 */
+  uint32_t align_errors; /* Alignment errors				 */
+}__attribute__((packed));
+
+struct pptp_set_link_info /* for control message type 15 */
+{
+  struct pptp_header header;
+  uint16_t call_id_peer; /* Peer's Call ID (call_id of pptp_out_call_rqst) */
+  uint16_t reserved1;    /* MUST BE ZERO                                   */
+  uint32_t send_accm;    /* Send ACCM (for PPP packets; default 0xFFFFFFFF)*/
+  uint32_t recv_accm;    /* Receive ACCM (for PPP pack.;default 0xFFFFFFFF)*/
+}__attribute__((packed));
+
+/* helpful #defines: -------------------------------------------- */
+#define pptp_isvalid_ctrl(header, type, length) \
+ (!( ( ntoh16(((struct pptp_header *)header)->length)    < (length)  ) ||   \
+     ( ntoh16(((struct pptp_header *)header)->pptp_type) !=(type)    ) ||   \
+     ( ntoh32(((struct pptp_header *)header)->magic)     !=PPTP_MAGIC) ||   \
+     ( ntoh16(((struct pptp_header *)header)->ctrl_type) > PPTP_SET_LINK_INFO) || \
+     ( ntoh16(((struct pptp_header *)header)->reserved0) !=0         ) ))
+
+#define PPTP_HEADER_CTRL(type)  \
+{ hton16(PPTP_CTRL_SIZE(type)), \
+  hton16(PPTP_MESSAGE_CONTROL), \
+  hton32(PPTP_MAGIC),           \
+  hton16(type), 0 }
+
+#define PPTP_CTRL_SIZE(type) ( \
+(type==PPTP_START_CTRL_CONN_RQST)?sizeof(struct pptp_start_ctrl_conn):	\
+(type==PPTP_START_CTRL_CONN_RPLY)?sizeof(struct pptp_start_ctrl_conn):	\
+(type==PPTP_STOP_CTRL_CONN_RQST )?sizeof(struct pptp_stop_ctrl_conn):	\
+(type==PPTP_STOP_CTRL_CONN_RPLY )?sizeof(struct pptp_stop_ctrl_conn):	\
+(type==PPTP_ECHO_RQST           )?sizeof(struct pptp_echo_rqst):	\
+(type==PPTP_ECHO_RPLY           )?sizeof(struct pptp_echo_rply):	\
+(type==PPTP_OUT_CALL_RQST       )?sizeof(struct pptp_out_call_rqst):	\
+(type==PPTP_OUT_CALL_RPLY       )?sizeof(struct pptp_out_call_rply):	\
+(type==PPTP_IN_CALL_RQST        )?sizeof(struct pptp_in_call_rqst):	\
+(type==PPTP_IN_CALL_RPLY        )?sizeof(struct pptp_in_call_rply):	\
+(type==PPTP_IN_CALL_CONNECT     )?sizeof(struct pptp_in_call_connect):	\
+(type==PPTP_CALL_CLEAR_RQST     )?sizeof(struct pptp_call_clear_rqst):	\
+(type==PPTP_CALL_CLEAR_NTFY     )?sizeof(struct pptp_call_clear_ntfy):	\
+(type==PPTP_WAN_ERR_NTFY        )?sizeof(struct pptp_wan_err_ntfy):	\
+(type==PPTP_SET_LINK_INFO       )?sizeof(struct pptp_set_link_info):	\
+0)
+#define max(a,b) (((a)>(b))?(a):(b))
+#define PPTP_CTRL_SIZE_MAX (			\
+max(sizeof(struct pptp_start_ctrl_conn),	\
+max(sizeof(struct pptp_echo_rqst),		\
+max(sizeof(struct pptp_echo_rply),		\
+max(sizeof(struct pptp_out_call_rqst),		\
+max(sizeof(struct pptp_out_call_rply),		\
+max(sizeof(struct pptp_in_call_rqst),		\
+max(sizeof(struct pptp_in_call_rply),		\
+max(sizeof(struct pptp_in_call_connect),	\
+max(sizeof(struct pptp_call_clear_rqst),	\
+max(sizeof(struct pptp_call_clear_ntfy),	\
+max(sizeof(struct pptp_wan_err_ntfy),		\
+max(sizeof(struct pptp_set_link_info), 0)))))))))))))
+
+#endif