ppp: Initial port of PPP to use GAtHDLC

1 files changed, 41 insertions, 359 deletions

diff --git a/gatchat/gatppp.c b/gatchat/gatppp.c
index c7bf089b..bd230bf4 100644
--- a/gatchat/gatppp.c
+++ b/gatchat/gatppp.c
@@ -35,6 +35,7 @@
 #include <glib.h>
 
 #include "gatutil.h"
+#include "gathdlc.h"
 #include "gatppp.h"
 #include "crc-ccitt.h"
 #include "ppp.h"
@@ -42,13 +43,6 @@
 #define DEFAULT_MRU	1500
 #define DEFAULT_MTU	1500
 
-#define BUFFERSZ	(DEFAULT_MRU * 2)
-
-#define PPP_ESC		0x7d
-#define PPP_FLAG_SEQ 	0x7e
-#define PPP_ADDR_FIELD	0xff
-#define PPP_CTRL	0x03
-
 struct _GAtPPP {
 	gint ref_count;
 	enum ppp_phase phase;
@@ -56,25 +50,17 @@ struct _GAtPPP {
 	struct pppcp_data *ipcp;
 	struct ppp_net *net;
 	struct ppp_chap *chap;
-	guint8 buffer[BUFFERSZ];
-	int index;
+	GAtHDLC *hdlc;
 	gint mru;
 	gint mtu;
 	char username[256];
 	char password[256];
-	guint32 xmit_accm[8];
-	guint32 recv_accm;
-	GIOChannel *modem;
 	GAtPPPConnectFunc connect_cb;
 	gpointer connect_data;
 	GAtDisconnectFunc disconnect_cb;
 	gpointer disconnect_data;
-	gint read_watch;
-	gint write_watch;
 	GAtDebugFunc debugf;
 	gpointer debug_data;
-	int record_fd;
-	GQueue *xmit_queue;
 };
 
 void ppp_debug(GAtPPP *ppp, const char *str)
@@ -85,99 +71,11 @@ void ppp_debug(GAtPPP *ppp, const char *str)
 	ppp->debugf(str, ppp->debug_data);
 }
 
-#define PPPINITFCS16    0xffff  /* Initial FCS value */
-#define PPPGOODFCS16    0xf0b8  /* Good final FCS value */
-
-struct frame_buffer {
-	gsize len;
-	guint8 bytes[0];
-};
-
-/*
- * escape any chars less than 0x20, and check the transmit accm table to
- * see if this character should be escaped.
- */
-static gboolean ppp_escape(GAtPPP *ppp, guint8 c, gboolean lcp)
-{
-	if ((lcp && c < 0x20) || (ppp->xmit_accm[c >> 5] & (1 << (c & 0x1f))))
-		return TRUE;
-	return FALSE;
-}
-
-static void ppp_put(GAtPPP *ppp, guint8 *buf, int *pos,
-			guint8 c, gboolean lcp)
-{
-	int i = *pos;
-
-	/* escape characters if needed,  copy into buf, increment pos */
-	if (ppp_escape(ppp, c, lcp)) {
-		buf[i++] = PPP_ESC;
-		buf[i++] = c ^ 0x20;
-	} else
-		buf[i++] = c;
-	*pos = i;
-}
-
-static struct frame_buffer *ppp_encode(GAtPPP *ppp, guint8 *data, int len)
-{
-	int pos = 0;
-	int i = 0;
-	guint16 fcs = PPPINITFCS16;
-	guint16 proto = get_host_short(data);
-	guint8 code;
-	gboolean lcp = (proto == LCP_PROTOCOL);
-	guint8 *frame;
-	struct frame_buffer *fb =
-		g_try_malloc0(BUFFERSZ + sizeof(struct frame_buffer));
-
-	if (!fb)
-		return NULL;
-	frame = fb->bytes;
-
-	/*
-	 * all LCP Link Configuration, Link Termination, and Code-Reject
-	 * packets must be sent with the default sending ACCM
-	 */
-	if (lcp) {
-		code = pppcp_get_code(data);
-		lcp = code > 0 && code < 8;
-	}
-
-	/* copy in the HDLC framing */
-	frame[pos++] = PPP_FLAG_SEQ;
-
-	/* from here till end flag, calculate FCS over each character */
-	fcs = crc_ccitt_byte(fcs, PPP_ADDR_FIELD);
-	ppp_put(ppp, frame, &pos, PPP_ADDR_FIELD, lcp);
-	fcs = crc_ccitt_byte(fcs, PPP_CTRL);
-	ppp_put(ppp, frame, &pos, PPP_CTRL, lcp);
-
-	/*
-	 * for each byte, first calculate FCS, then do escaping if
-	 * neccessary
-	 */
-	while (len--) {
-		fcs = crc_ccitt_byte(fcs, data[i]);
-		ppp_put(ppp, frame, &pos, data[i++], lcp);
-	}
-
-	/* add FCS */
-	fcs ^= 0xffff;		/* complement */
-	ppp_put(ppp, frame, &pos, (guint8)(fcs & 0x00ff), lcp);
-	ppp_put(ppp, frame, &pos, (guint8)((fcs >> 8) & 0x00ff), lcp);
-
-	/* add flag */
-	frame[pos++] = PPP_FLAG_SEQ;
-
-	fb->len = pos;
-	return fb;
-}
-
-/* called when we have received a complete ppp frame */
-static void ppp_recv(GAtPPP *ppp, struct frame_buffer *frame)
+static void ppp_receive(const unsigned char *buf, gsize len, void *data)
 {
-	guint16 protocol = ppp_proto(frame->bytes);
-	guint8 *packet = ppp_info(frame->bytes);
+	GAtPPP *ppp = data;
+	guint16 protocol = ppp_proto(buf);
+	const guint8 *packet = ppp_info(buf);
 
 	/*
 	 * Any non-LCP packets received during Link Establishment
@@ -205,144 +103,42 @@ static void ppp_recv(GAtPPP *ppp, struct frame_buffer *frame)
 		}
 		/* fall through */
 	default:
-		pppcp_send_protocol_reject(ppp->lcp, frame->bytes, frame->len);
+		pppcp_send_protocol_reject(ppp->lcp, buf, len);
 		break;
 	};
 }
 
-static struct frame_buffer *ppp_decode(GAtPPP *ppp, guint8 *frame)
-{
-	guint8 *data;
-	guint pos;
-	int i;
-	guint16 fcs;
-	struct frame_buffer *fb;
-
-	fb = g_try_malloc0(sizeof(struct frame_buffer) + ppp->mru + 10);
-	if (!fb)
-		return NULL;
-	data = fb->bytes;
-
-	/* skip the first flag char */
-	pos = 1;
-
-	fcs = PPPINITFCS16;
-	i = 0;
-
-	while (frame[pos] != PPP_FLAG_SEQ) {
-		/* Skip the characters in receive ACCM */
-		if (frame[pos] < 0x20 &&
-				(ppp->recv_accm & (1 << frame[pos])) != 0) {
-			pos++;
-			continue;
-		}
-
-		/* scan for escape character */
-		if (frame[pos] == PPP_ESC) {
-			/* skip that char */
-			pos++;
-			data[i] = frame[pos] ^ 0x20;
-		} else
-			data[i] = frame[pos];
-
-		fcs = crc_ccitt_byte(fcs, data[i]);
-
-		i++; pos++;
-	}
-
-	fb->len = i;
-
-	/* see if we have a good FCS */
-	if (fcs != PPPGOODFCS16) {
-		g_free(fb);
-		return NULL;
-	}
-
-	return fb;
-}
-
-static void ppp_feed(GAtPPP *ppp, guint8 *data, gsize len)
+/*
+ * transmit out through the lower layer interface
+ *
+ * infolen - length of the information part of the packet
+ */
+void ppp_transmit(GAtPPP *ppp, guint8 *packet, guint infolen)
 {
-	guint pos = 0;
-	struct frame_buffer *frame;
+	guint16 proto = get_host_short(packet);
+	guint8 code;
+	gboolean lcp = (proto == LCP_PROTOCOL);
+	guint32 xmit_accm = 0;
 
-	/* collect bytes until we detect we have received a complete frame */
-	/* examine the data.  If we are at the beginning of a new frame,
-	 * allocate memory to buffer the frame.
+	/*
+	 * all LCP Link Configuration, Link Termination, and Code-Reject
+	 * packets must be sent with the default sending ACCM
 	 */
-
-	for (pos = 0; pos < len; pos++) {
-		if (data[pos] == PPP_FLAG_SEQ) {
-			if (ppp->index != 0) {
-				/* store last flag character & decode */
-				ppp->buffer[ppp->index++] = data[pos];
-				frame = ppp_decode(ppp, ppp->buffer);
-				if (frame) {
-					/* process receive frame */
-					ppp_recv(ppp, frame);
-					g_free(frame);
-				}
-
-				/* zero buffer */
-				memset(ppp->buffer, 0, BUFFERSZ);
-				ppp->index = 0;
-				continue;
-			}
-		}
-		/* copy byte to buffer */
-		if (ppp->index < BUFFERSZ)
-			ppp->buffer[ppp->index++] = data[pos];
+	if (lcp) {
+		code = pppcp_get_code(packet);
+		lcp = code > 0 && code < 8;
 	}
-}
 
-static void ppp_record(GAtPPP *ppp, gboolean in, guint8 *data, guint16 length)
-{
-	guint16 len = htons(length);
-	guint32 ts;
-	struct timeval now;
-	unsigned char id;
-	int err;
-
-	if (ppp->record_fd < 0)
-		return;
-
-	gettimeofday(&now, NULL);
-	ts = htonl(now.tv_sec & 0xffffffff);
-
-	id = 0x07;
-	err = write(ppp->record_fd, &id, 1);
-	err = write(ppp->record_fd, &ts, 4);
-
-	id = in ? 0x02 : 0x01;
-	err = write(ppp->record_fd, &id, 1);
-	err = write(ppp->record_fd, &len, 2);
-	err = write(ppp->record_fd, data, length);
-}
-
-static gboolean ppp_read_cb(GIOChannel *channel, GIOCondition cond,
-								gpointer data)
-{
-	GAtPPP *ppp = data;
-	GIOStatus status;
-	gchar buf[256];
-	gsize bytes_read;
-	GError *error = NULL;
-
-	if (cond & (G_IO_NVAL | G_IO_ERR | G_IO_HUP))
-		return FALSE;
-
-	if (cond & G_IO_IN) {
-		status = g_io_channel_read_chars(channel, buf, 256,
-				&bytes_read, &error);
-		if (bytes_read > 0) {
-			ppp_record(ppp, TRUE, (guint8 *) buf, bytes_read);
-			ppp_feed(ppp, (guint8 *) buf, bytes_read);
-		}
-		if (status != G_IO_STATUS_NORMAL && status != G_IO_STATUS_AGAIN)
-			return FALSE;
+	if (lcp) {
+		xmit_accm = g_at_hdlc_get_xmit_accm(ppp->hdlc);
+		g_at_hdlc_set_xmit_accm(ppp->hdlc, ~0U);
 	}
 
-	return TRUE;
+	if (g_at_hdlc_send(ppp->hdlc, packet, infolen + 2) == FALSE)
+		g_print("Failed to send a frame\n");
+
+	if (lcp)
+		g_at_hdlc_set_xmit_accm(ppp->hdlc, xmit_accm);
 }
 
 static void ppp_dead(GAtPPP *ppp)
@@ -392,12 +188,6 @@ void ppp_enter_phase(GAtPPP *ppp, enum ppp_phase phase)
 	}
 }
 
-static void read_watcher_destroy_notify(GAtPPP *ppp)
-{
-	ppp->read_watch = 0;
-	pppcp_signal_down(ppp->lcp);
-}
-
 void ppp_set_auth(GAtPPP *ppp, const guint8* auth_data)
 {
 	guint16 proto = get_host_short(auth_data);
@@ -451,12 +241,12 @@ void ppp_net_down_notify(GAtPPP *ppp)
 
 void ppp_set_recv_accm(GAtPPP *ppp, guint32 accm)
 {
-	ppp->recv_accm = accm;
+	g_at_hdlc_set_recv_accm(ppp->hdlc, accm);
 }
 
 void ppp_set_xmit_accm(GAtPPP *ppp, guint32 accm)
 {
-	ppp->xmit_accm[0] = accm;
+	g_at_hdlc_set_xmit_accm(ppp->hdlc, accm);
 }
 
 /*
@@ -536,23 +326,6 @@ void g_at_ppp_set_debug(GAtPPP *ppp, GAtDebugFunc func, gpointer user_data)
 	ppp->debug_data = user_data;
 }
 
-void g_at_ppp_set_recording(GAtPPP *ppp, const char *filename)
-{
-	if (ppp == NULL)
-		return;
-
-	if (ppp->record_fd > fileno(stderr)) {
-		close(ppp->record_fd);
-		ppp->record_fd = -1;
-	}
-
-	if (filename == NULL)
-		return;
-
-	ppp->record_fd = open(filename, O_WRONLY | O_CREAT | O_APPEND,
-					S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH);
-}
-
 void g_at_ppp_shutdown(GAtPPP *ppp)
 {
 	pppcp_signal_close(ppp->lcp);
@@ -572,24 +345,15 @@ void g_at_ppp_unref(GAtPPP *ppp)
 	if (is_zero == FALSE)
 		return;
 
-	if (ppp->record_fd > fileno(stderr))
-		close(ppp->record_fd);
-
-	/* cleanup queue */
-	g_queue_free(ppp->xmit_queue);
+	if (ppp->net)
+		ppp_net_free(ppp->net);
 
-	/* cleanup modem channel */
-	g_source_remove(ppp->read_watch);
-	g_source_remove(ppp->write_watch);
-	g_io_channel_unref(ppp->modem);
+	if (ppp->chap)
+		ppp_chap_free(ppp->chap);
 
 	lcp_free(ppp->lcp);
-	ppp_chap_free(ppp->chap);
 	ipcp_free(ppp->ipcp);
 
-	if (ppp->net)
-		ppp_net_free(ppp->net);
-
 	g_free(ppp);
 }
 
@@ -601,25 +365,18 @@ GAtPPP *g_at_ppp_new(GIOChannel *modem)
 	if (!ppp)
 		return NULL;
 
-	if (!g_at_util_setup_io(modem, G_IO_FLAG_NONBLOCK)) {
+	ppp->hdlc = g_at_hdlc_new(modem);
+
+	if (ppp->hdlc == NULL) {
 		g_free(ppp);
 		return NULL;
 	}
-	g_io_channel_set_buffered(modem, FALSE);
 
 	ppp->ref_count = 1;
 
 	/* set options to defaults */
 	ppp->mru = DEFAULT_MRU;
 	ppp->mtu = DEFAULT_MTU;
-	ppp->recv_accm = ~0U;
-	ppp->xmit_accm[0] = ~0U;
-	ppp->xmit_accm[3] = 0x60000000; /* 0x7d, 0x7e */
-
-	ppp->index = 0;
-
-	/* intialize the queue */
-	ppp->xmit_queue = g_queue_new();
 
 	/* initialize the lcp state */
 	ppp->lcp = lcp_new(ppp);
@@ -627,82 +384,7 @@ GAtPPP *g_at_ppp_new(GIOChannel *modem)
 	/* initialize IPCP state */
 	ppp->ipcp = ipcp_new(ppp);
 
-	/* start listening for packets from the modem */
-	ppp->read_watch = g_io_add_watch_full(modem, G_PRIORITY_DEFAULT,
-				G_IO_IN | G_IO_HUP | G_IO_ERR | G_IO_NVAL,
-				ppp_read_cb, ppp,
-				(GDestroyNotify)read_watcher_destroy_notify);
-
-	ppp->modem = modem;
-	ppp->record_fd = -1;
+	g_at_hdlc_set_receive(ppp->hdlc, ppp_receive, ppp);
 
 	return ppp;
 }
-
-static gboolean ppp_xmit_cb(GIOChannel *channel, GIOCondition cond,
-				gpointer data)
-{
-	GAtPPP *ppp = data;
-	struct frame_buffer *fb;
-	GError *error = NULL;
-	GIOStatus status;
-	gsize bytes_written;
-
-	if (cond & (G_IO_NVAL | G_IO_HUP | G_IO_ERR))
-		return FALSE;
-
-	if (cond & G_IO_OUT) {
-		while ((fb = g_queue_peek_head(ppp->xmit_queue))) {
-			status = g_io_channel_write_chars(ppp->modem,
-					(gchar *) fb->bytes, fb->len,
-					&bytes_written, &error);
-			if (status != G_IO_STATUS_NORMAL &&
-				status != G_IO_STATUS_AGAIN)
-				return FALSE;
-
-			if (bytes_written < fb->len)
-				return TRUE;
-
-			ppp_record(ppp, FALSE, fb->bytes, bytes_written);
-			g_free(g_queue_pop_head(ppp->xmit_queue));
-		}
-	}
-	return FALSE;
-}
-
-static void ppp_xmit_destroy_notify(gpointer destroy_data)
-{
-	GAtPPP *ppp = destroy_data;
-
-	ppp->write_watch = 0;
-
-	if (ppp->phase == PPP_PHASE_DEAD)
-		ppp_dead(ppp);
-}
-
-/*
- * transmit out through the lower layer interface
- *
- * infolen - length of the information part of the packet
- */
-void ppp_transmit(GAtPPP *ppp, guint8 *packet, guint infolen)
-{
-	struct frame_buffer *fb;
-
-	/*
-	 * do the octet stuffing.  Add 2 bytes to the infolen to
-	 * include the protocol field.
-	 */
-	fb = ppp_encode(ppp, packet, infolen + 2);
-	if (!fb) {
-		g_printerr("Failed to encode packet to transmit\n");
-		return;
-	}
-	/* push decoded frame onto xmit queue */
-	g_queue_push_tail(ppp->xmit_queue, fb);
-
-	/* transmit this whenever we can write without blocking */
-	ppp->write_watch = g_io_add_watch_full(ppp->modem, G_PRIORITY_DEFAULT,
-				G_IO_OUT | G_IO_HUP | G_IO_ERR | G_IO_NVAL,
-				ppp_xmit_cb, ppp, ppp_xmit_destroy_notify);
-}