Add PPP protocol support with HDLC framing

This patch implements the basic PPP protocol. LCP, NCP etc. are handled in
a different patch.

Index: ofono/Makefile.am

Makefile.am +3 -1

@@ -55,7 +55,9 @@
 				gatchat/gattty.h gatchat/gattty.c \
 				gatchat/gatutil.h gatchat/gatutil.c \
 				gatchat/gat.h \
-				gatchat/gatserver.h gatchat/gatserver.c
+				gatchat/gatserver.h gatchat/gatserver.c \
+				gatchat/gatppp.c gatchat/gatppp.h \
+				gatchat/gatppp_internal.h
 
 udev_files = plugins/ofono.rules
 

Index: ofono/gatchat/gatppp_internal.h

gatchat/gatppp_internal.h new file +57 -0

@@ -0,0 +1,97 @@
+/*
+ *
+ *  PPP library with GLib integration
+ *
+ *  Copyright (C) 2010  Intel Corporation. All rights reserved.
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License version 2 as
+ *  published by the Free Software Foundation.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 
 USA + *
+ */
+
+#ifndef __G_AT_PPP_INTERNAL_H
+#define __G_AT_PPP_INTERNAL_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#define DEFAULT_MRU	1500
+#define BUFFERSZ	DEFAULT_MRU*2
+#define DEFAULT_ACCM	0x00000000
+#define PPP_ESC		0x7d
+#define PPP_FLAG_SEQ 	0x7e
+#define PPP_ADDR_FIELD	0xff
+#define PPP_CTRL	0x03
+#define LCP_PROTOCOL	0xc021
+#define CHAP_PROTOCOL	0xc223
+#define PPP_HEADROOM	2
+#define HDLC_HEADROOM	3
+#define HDLC_TAIL	3
+#define MD5		5
+
+enum PPP_PHASE {
+	DEAD = 0,
+	ESTABLISHMENT,
+	AUTHENTICATION,
+	NETWORK,
+	TERMINATION,
+};
+
+enum PPP_EVENTS {
+	PPP_UP = 1,
+	PPP_OPENED,
+	PPP_SUCCESS,
+	PPP_NONE,
+	PPP_CLOSING,
+	PPP_FAIL,
+	PPP_DOWN

gatchat/gatppp_internal.h new file +23 -0

+
+#define ppp_info(packet) \
+	(packet+4)
+
+#define ppp_proto(packet) \
+	(ntohs(*((guint16*)(packet+2))))
+
+void __ppp_generate_event(struct ppp_link *link, guint event);
+void __ppp_register_packet_handler(struct ppp_packet_handler *handler);
+void __ppp_transmit(struct ppp_link *link, guint8 *packet, guint infolen);
+void __ppp_set_auth(struct ppp_link *link, guint8 *auth_data);
+void __ppp_set_recv_accm(struct ppp_link *link, guint32 accm);
+guint32 __ppp_get_xmit_accm(struct ppp_link *link);
+void __ppp_set_pfc(struct ppp_link *link, gboolean pfc);
+gboolean __ppp_get_pfc(struct ppp_link *link);
+void __ppp_set_acfc(struct ppp_link *link, gboolean acfc);
+gboolean __ppp_get_acfc(struct ppp_link *link);
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* __G_AT_PPP_INTERNAL_H */
+

Index: ofono/gatchat/gatppp.c

gatchat/gatppp.c new file +252 -0

@@ -0,0 +1,557 @@
+/*
+ *
+ *  PPP library with GLib integration
+ *
+ *  Copyright (C) 2010  Intel Corporation. All rights reserved.
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License version 2 as
+ *  published by the Free Software Foundation.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 
 USA + *
+ */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <stdio.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <string.h>
+#include <termios.h>
+#include <arpa/inet.h>
+
+#include <glib.h>
+
+#include "gatppp.h"
+#include "gatppp_internal.h"
+
+#define PPPINITFCS16    0xffff  /* Initial FCS value */
+#define PPPGOODFCS16    0xf0b8  /* Good final FCS value */
+
+static GList *packet_handlers = NULL;
+
+void __ppp_register_packet_handler(struct ppp_packet_handler *handler)
+{
+	packet_handlers = g_list_append(packet_handlers, handler);
+}
+
+/*
+ * FCS lookup table copied from rfc1662.
+ */
+static guint16 fcstab[256] = {
+	0x0000, 0x1189, 0x2312, 0x329b, 0x4624, 0x57ad, 0x6536, 0x74bf,
+	0x8c48, 0x9dc1, 0xaf5a, 0xbed3, 0xca6c, 0xdbe5, 0xe97e, 0xf8f7,
+	0x1081, 0x0108, 0x3393, 0x221a, 0x56a5, 0x472c, 0x75b7, 0x643e,
+	0x9cc9, 0x8d40, 0xbfdb, 0xae52, 0xdaed, 0xcb64, 0xf9ff, 0xe876,
+	0x2102, 0x308b, 0x0210, 0x1399, 0x6726, 0x76af, 0x4434, 0x55bd,
+	0xad4a, 0xbcc3, 0x8e58, 0x9fd1, 0xeb6e, 0xfae7, 0xc87c, 0xd9f5,
+	0x3183, 0x200a, 0x1291, 0x0318, 0x77a7, 0x662e, 0x54b5, 0x453c,
+	0xbdcb, 0xac42, 0x9ed9, 0x8f50, 0xfbef, 0xea66, 0xd8fd, 0xc974,
+	0x4204, 0x538d, 0x6116, 0x709f, 0x0420, 0x15a9, 0x2732, 0x36bb,
+	0xce4c, 0xdfc5, 0xed5e, 0xfcd7, 0x8868, 0x99e1, 0xab7a, 0xbaf3,
+	0x5285, 0x430c, 0x7197, 0x601e, 0x14a1, 0x0528, 0x37b3, 0x263a,
+	0xdecd, 0xcf44, 0xfddf, 0xec56, 0x98e9, 0x8960, 0xbbfb, 0xaa72,
+	0x6306, 0x728f, 0x4014, 0x519d, 0x2522, 0x34ab, 0x0630, 0x17b9,
+	0xef4e, 0xfec7, 0xcc5c, 0xddd5, 0xa96a, 0xb8e3, 0x8a78, 0x9bf1,
+	0x7387, 0x620e, 0x5095, 0x411c, 0x35a3, 0x242a, 0x16b1, 0x0738,
+	0xffcf, 0xee46, 0xdcdd, 0xcd54, 0xb9eb, 0xa862, 0x9af9, 0x8b70,
+	0x8408, 0x9581, 0xa71a, 0xb693, 0xc22c, 0xd3a5, 0xe13e, 0xf0b7,
+	0x0840, 0x19c9, 0x2b52, 0x3adb, 0x4e64, 0x5fed, 0x6d76, 0x7cff,
+	0x9489, 0x8500, 0xb79b, 0xa612, 0xd2ad, 0xc324, 0xf1bf, 0xe036,
+	0x18c1, 0x0948, 0x3bd3, 0x2a5a, 0x5ee5, 0x4f6c, 0x7df7, 0x6c7e,
+	0xa50a, 0xb483, 0x8618, 0x9791, 0xe32e, 0xf2a7, 0xc03c, 0xd1b5,
+	0x2942, 0x38cb, 0x0a50, 0x1bd9, 0x6f66, 0x7eef, 0x4c74, 0x5dfd,
+	0xb58b, 0xa402, 0x9699, 0x8710, 0xf3af, 0xe226, 0xd0bd, 0xc134,
+	0x39c3, 0x284a, 0x1ad1, 0x0b58, 0x7fe7, 0x6e6e, 0x5cf5, 0x4d7c,
+	0xc60c, 0xd785, 0xe51e, 0xf497, 0x8028, 0x91a1, 0xa33a, 0xb2b3,
+	0x4a44, 0x5bcd, 0x6956, 0x78df, 0x0c60, 0x1de9, 0x2f72, 0x3efb,
+	0xd68d, 0xc704, 0xf59f, 0xe416, 0x90a9, 0x8120, 0xb3bb, 0xa232,
+	0x5ac5, 0x4b4c, 0x79d7, 0x685e, 0x1ce1, 0x0d68, 0x3ff3, 0x2e7a,
+	0xe70e, 0xf687, 0xc41c, 0xd595, 0xa12a, 0xb0a3, 0x8238, 0x93b1,
+	0x6b46, 0x7acf, 0x4854, 0x59dd, 0x2d62, 0x3ceb, 0x0e70, 0x1ff9,
+	0xf78f, 0xe606, 0xd49d, 0xc514, 0xb1ab, 0xa022, 0x92b9, 0x8330,
+	0x7bc7, 0x6a4e, 0x58d5, 0x495c, 0x3de3, 0x2c6a, 0x1ef1, 0x0f78
+};
+
+/*
+ * Calculate a new fcs given the current fcs and the new data.
+ * copied from rfc1662
+ *
+ *     The FCS field is calculated over all bits of the Address, Control,
+ *     Protocol, Information and Padding fields, not including any start
+ *     and stop bits (asynchronous) nor any bits (synchronous) or octets
+ *     (asynchronous or synchronous) inserted for transparency.  This
+ *     also does not include the Flag Sequences nor the FCS field itself.
+ */
+static guint16 ppp_fcs(guint16 fcs, guint8 c)
+{
+	guint16 new_fcs;
+
+	new_fcs = (fcs >> 8) ^ fcstab[(fcs ^ c) & 0xff];
+	return new_fcs;
+}
+
+/*
+ * escape any chars less than 0x20, and check the transmit accm table to
+ * see if this character should be escaped.
+ */
+static gboolean ppp_escape(struct ppp_link *link, guint8 c, gboolean lcp)
+{
+	if ((lcp && c < 0x20) || (link->xmit_accm[c >> 5] & (1 << (c & 0x1f))))
+		return TRUE;
+	return FALSE;
+}
+
+static void ppp_put(struct ppp_link *link, guint8 *buf, int *pos,
+			guint8 c, gboolean lcp)
+{
+	int i = *pos;
+
+	/* escape characters if needed,  copy into buf, increment pos */
+	if (ppp_escape(link, c, lcp)) {
+		buf[i++] = PPP_ESC;
+		buf[i++] = c ^ 0x20;
+	} else
+		buf[i++] = c;
+	*pos = i;
+}
+
+/* XXX implement PFC and ACFC */
+static guint8 *ppp_encode(struct ppp_link *link, guint8 *data, int len,
+				guint *newlen)
+{
+	guint8 *frame = g_malloc0(BUFFERSZ);
+	int pos = 0;
+	int i = 0;
+	guint16 fcs = PPPINITFCS16;
+	guint16 proto = ntohs(*(guint16 *)data);
+	gboolean lcp = (proto == LCP_PROTOCOL);
+	if (!frame)
+		return NULL;
+
+	/* copy in the HDLC framing */
+	frame[pos++] = PPP_FLAG_SEQ;
+
+	/* from here till end flag, calculate FCS over each character */
+	fcs = ppp_fcs(fcs, PPP_ADDR_FIELD);
+	ppp_put(link, frame, &pos, PPP_ADDR_FIELD, lcp);
+	fcs = ppp_fcs(fcs, PPP_CTRL);
+	ppp_put(link, frame, &pos, PPP_CTRL, lcp);
+
+	/*
+	 * for each byte, first calculate FCS, then do escaping if
+	 * neccessary
+	 */
+	while (len--) {
+		fcs = ppp_fcs(fcs, data[i]);
+		ppp_put(link, frame, &pos, data[i++], lcp);
+	}
+
+	/* add FCS */
+	fcs ^= 0xffff;                 /* complement */
+	ppp_put(link, frame, &pos, (guint8)(fcs & 0x00ff), lcp);
+	ppp_put(link, frame, &pos, (guint8)((fcs >> 8) & 0x00ff), lcp);
+
+	/* add flag */
+	frame[pos++] = PPP_FLAG_SEQ;
+
+	*newlen = pos;
+	return frame;
+}
+
+static gint is_proto_handler(struct ppp_packet_handler *h, gpointer user)
+{
+	guint16 proto = (guint16) GPOINTER_TO_UINT(user);
+
+	if (h->proto == proto)
+		return 0;
+	else
+		return -1;
+}
+
+/* called when we have received a complete ppp frame */
+static void ppp_recv(struct ppp_link *link)
+{
+	guint16 protocol;
+	guint8 *frame, *packet;
+	GList *list;
+	struct ppp_packet_handler *h;
+
+	/* pop frames off of receive queue */
+	while ((frame = g_queue_pop_head(link->recv_queue))) {
+		protocol = ppp_proto(frame);
+		packet = ppp_info(frame);
+
+		/*
+		 * check to see if we have a protocol handler
+		 * registered for this packet
+		 */
+		list = g_list_find_custom(packet_handlers,
+				GUINT_TO_POINTER(protocol),
+				(GCompareFunc) is_proto_handler);
+		if (list) {
+			h = list->data;
+			h->handler(h->priv, packet);
+		}
+		g_free(frame);
+	}
+}
+
+/* XXX - Implement PFC and ACFC */
+static guint8 * ppp_decode(struct ppp_link *link, guint8 *frame)
+{
+	guint8 *data;
+	guint pos = 0;
+	int i = 0;
+	int len;
+	guint16 fcs;
+
+	data = g_malloc0(link->mru + 10);
+
+	/* skip the first flag char */
+	pos++;
+
+	/* TBD - how to deal with recv_accm */
+	while (frame[pos] != PPP_FLAG_SEQ) {
+		/* scan for escape character */
+		if (frame[pos] == PPP_ESC) {
+			/* skip that char */
+			pos++;
+			data[i] = frame[pos] ^ 0x20;
+		} else
+			data[i] = frame[pos];
+		i++; pos++;
+	}
+
+	len = i;
+
+	/* see if we have a good FCS */
+	fcs = PPPINITFCS16;
+	for (i = 0; i < len; i++)
+		fcs = ppp_fcs(fcs, data[i]);
+
+	if (fcs != PPPGOODFCS16) {
+		g_free(data);
+		return NULL;
+	}
+	return data;
+}
+
+static void ppp_feed(struct ppp_link *link, guint8 *data, gsize len)
+{
+	guint pos = 0;
+	guint8 *frame;

gatchat/gatppp.c new file +5 -0

+				/* push decoded frame onto receive queue */
+				if (frame)
+					g_queue_push_tail(link->recv_queue,
+								frame);
+

gatchat/gatppp.c new file +30 -0

+		else
+			g_printerr("oops, no buffer, no start of frame\n");
+
+	}
+	/* process receive queue */
+	ppp_recv(link);
+}
+
+/*
+ * transmit out through the lower layer interface
+ *
+ * infolen - length of the information part of the packet
+ */
+void __ppp_transmit(struct ppp_link *link, guint8 *packet, guint infolen)
+{
+	guint8 *frame;
+	guint framelen;
+        GError *error = NULL;
+        GIOStatus status;
+        gsize bytes_written;
+
+	/*
+	 * do the octet stuffing.  Add 2 bytes to the infolen to
+	 * include the protocol field.
+	 */
+	frame = ppp_encode(link, packet, infolen+2, &framelen);
+	if (!frame) {
+		g_printerr("Failed to encode packet to transmit\n");
+		return;
+	}

gatchat/gatppp.c new file +179 -0

+
+}
+
+static gboolean ppp_cb(GIOChannel *channel, GIOCondition cond, gpointer
 data) +{
+	struct ppp_link *ppp = (struct ppp_link *) data;
+	GIOStatus status;
+	gchar buf[256];
+	gsize bytes_read;
+	GError *error = NULL;
+
+	if (cond & (G_IO_NVAL | G_IO_ERR | G_IO_HUP)) {
+		g_print("G_IO_NVAL | G_IO_ERR");
+		return FALSE;
+	}
+
+	if (cond & G_IO_IN) {
+		status = g_io_channel_read_chars(channel, buf, 256,
+				&bytes_read, &error);
+		if (bytes_read > 0)
+			ppp_feed(ppp, (guint8 *)buf, bytes_read);
+        	if (status != G_IO_STATUS_NORMAL && status != G_IO_STATUS_AGAIN)
+                	return FALSE;
+	}
+
+	return TRUE;
+}
+
+/* Administrative Close */
+static void ppp_close(struct ppp_link *link)
+{
+	/* send a CLOSE event to the lcp layer */
+}
+
+/* Administrative Open */
+void g_at_ppp_open(struct ppp_link *link)
+{
+	/* send an OPEN event to the lcp layer */
+}
+
+static void ppp_link_establishment(struct ppp_link *link)
+{
+	/* signal UP event to LCP */
+}
+
+static void ppp_terminate(struct ppp_link *link)
+{
+	/* signal DOWN event to LCP */
+}
+
+static void ppp_authenticate(struct ppp_link *link)
+{
+	/* we don't do authentication right now, so send NONE */
+	if (!link->auth_proto)
+		ppp_generate_event(link, PPP_NONE);
+	/* otherwise we need to wait for the peer to send us a challenge */
+}
+
+static void ppp_dead(struct ppp_link *link)
+{
+	/* re-initialize everything */
+}
+
+static void ppp_network(struct ppp_link *link)
+{
+	/* bring network phase up */
+}
+
+static void ppp_transition_phase(struct ppp_link *link, guint phase)
+{
+	/* don't do anything if we're already there */
+	if (link->phase == phase)
+		return;
+
+	/* set new phase */
+	link->phase = phase;
+
+	switch(phase) {
+	case ESTABLISHMENT:
+		ppp_link_establishment(link);
+		break;
+	case AUTHENTICATION:
+		ppp_authenticate(link);
+		break;
+	case TERMINATION:
+		ppp_terminate(link);
+		break;
+	case DEAD:
+		ppp_dead(link);
+		break;
+	case NETWORK:
+		ppp_network(link);
+		break;
+	default:
+		break;
+	}
+
+}
+
+static void ppp_handle_event(struct ppp_link *link)
+{
+	guint event;
+
+	while ((event = GPOINTER_TO_UINT(g_queue_pop_head(link->event_queue)))){
+		switch(event) {
+		case PPP_UP:
+			/* causes transition to link establishment */
+			ppp_transition_phase(link, ESTABLISHMENT);
+			break;
+		case PPP_OPENED:
+			ppp_transition_phase(link, AUTHENTICATION);
+			break;
+		case PPP_CLOSING:
+			/* causes transition to termination phase */
+			ppp_transition_phase(link, TERMINATION);
+			break;
+		case PPP_DOWN:
+			/* cases transition to dead phase */
+			ppp_transition_phase(link, DEAD);
+			break;
+		case PPP_NONE:
+		case PPP_SUCCESS:
+			/* causes transition to network phase */
+			ppp_transition_phase(link, NETWORK);
+			break;
+		}
+	}
+}
+
+/*
+ * send the event handler a new event to process
+ */
+void __ppp_generate_event(struct ppp_link *link, guint event)
+{
+	g_queue_push_tail(link->event_queue, GUINT_TO_POINTER(event));
+	ppp_handle_event(link);
+}
+
+void g_at_ppp_set_connect_function(struct ppp_link *link,
+			       GAtPPPConnectFunc callback, gpointer user_data)
+{
+	link->connect_cb = callback;
+	link->connect_priv = user_data;
+}
+
+void g_at_ppp_set_disconnect_function(struct ppp_link *link,
+				  GAtPPPDisconnectFunc callback,
+				  gpointer user_data)
+{
+	link->disconnect_cb = callback;
+	link->disconnect_priv = user_data;
+}
+
+void g_at_ppp_shutdown(struct ppp_link *link)
+{
+	/* close the link */
+	ppp_close(link);
+
+	/* clean up all the queues */
+	g_queue_free(link->event_queue);
+	g_queue_free(link->recv_queue);
+
+	/* cleanup modem channel */
+	g_source_remove(link->modem_watch);
+	g_io_channel_unref(link->modem);
+}
+
+void g_at_ppp_ref(struct ppp_link *link)
+{
+	g_atomic_int_inc(&link->ref_count);
+}
+
+void g_at_ppp_unref(struct ppp_link *link)
+{
+	gboolean last;
+
+	last = g_atomic_int_dec_and_test(&link->ref_count);
+	if (last) {
+		g_at_ppp_shutdown(link);
+		g_free(link);

gatchat/gatppp.c new file +18 -0

+	if (!link)
+		return NULL;
+
+	link->ref_count = 1;
+
+	/* set options to defaults */
+	link->mru = DEFAULT_MRU;
+	link->recv_accm = DEFAULT_ACCM;
+	link->xmit_accm[0] = DEFAULT_ACCM;
+	link->xmit_accm[3] = 0x60000000; /* 0x7d, 0x7e */
+	link->pfc = FALSE;
+	link->acfc = FALSE;
+
+	/* allocate the queues */
+	link->event_queue = g_queue_new();
+	link->recv_queue = g_queue_new();
+
+	link->buffer = NULL;

gatchat/gatppp.c new file +4 -0

+
+	/* initialize the lcp state */
+
+

gatchat/gatppp.c new file +3 -0

+
+	return link;
+}

Index: ofono/gatchat/gatppp.h

gatchat/gatppp.h new file +18 -0

@@ -0,0 +1,81 @@
+/*
+ *
+ *  PPP library with GLib integration
+ *
+ *  Copyright (C) 2010  Intel Corporation. All rights reserved.
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License version 2 as
+ *  published by the Free Software Foundation.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 
 USA + *

gatchat/gatppp.h new file +5 -0

+	guint8 *buffer;
+	int index;
+	gint mru;
+	guint16 auth_proto;
+	char user_name[256];

gatchat/gatppp.h new file +6 -0

+struct ppp_link * g_at_ppp_new(GIOChannel *modem);
+void g_at_ppp_open(struct ppp_link *link);
+void g_at_ppp_set_connect_function(struct ppp_link *link,
+			       GAtPPPConnectFunc callback, gpointer user_data);
+void g_at_ppp_set_disconnect_function(struct ppp_link *link,
+				  GAtPPPDisconnectFunc callback,

Quoted 6 lines

gatchat/gatppp.h new file +6 -0

+struct ppp_link * g_at_ppp_new(GIOChannel *modem);
+void g_at_ppp_open(struct ppp_link *link);
+void g_at_ppp_set_connect_function(struct ppp_link *link,
+			       GAtPPPConnectFunc callback, gpointer user_data);
+void g_at_ppp_set_disconnect_function(struct ppp_link *link,
+				  GAtPPPDisconnectFunc callback,

gatchat/gatppp.h line 75

Quoted 4 lines

gatchat/gatppp.h new file +4 -0

+				  gpointer user_data);
+void g_at_ppp_shutdown(struct ppp_link *link);
+void g_at_ppp_ref(struct ppp_link *link);
+void g_at_ppp_unref(struct ppp_link *link);

Almost forgot, let us not use struct ppp_link here, but instead use GAtPpp *ppp as the parameter. Again, mostly for consistency with how glib / gatchat does this.

gatchat/gsmdial.c +1 -0

 static GAtChat *control;
 static GAtChat *modem;
 static GMainLoop *event_loop;
+static struct ppp_link *ppp;
 
 enum state {
 	STATE_NONE = 0,

gatchat/gsmdial.c +7 -0

+static void ppp_connect(struct ppp_link *link, gint success, guint32 ip_addr,
+		 guint32 dns1, guint32 dns2, gpointer user_data)
+{
+	if (success == PPP_CONNECT_SUCCESS) {
+		/* print out the negotiated address and dns server */
+		g_print("Negotiated IP Address: ");
+		print_ip_address(ip_addr);

gatchat/gsmdial.c +6 -0

+	/* open ppp */
+	ppp = g_at_ppp_new(channel);
+	if (ppp) {
+		g_print("Setting PPP Credentials to %s, %s\n", option_username,
+				option_passwd);
+		g_at_ppp_set_credentials(ppp, option_username,

gatchat/gsmdial.c +0 -0

 static void at_cgdcont_cb(gboolean ok, GAtResult *result, gpointer user_data)
 {
 	char buf[64];

@@ -231,8 +302,14 @@
 
 	if (option_legacy == TRUE) {
 			sprintf(buf, "ATD*99***%u#", option_cid);

Implement IPCP support. Creates a tun interface to pass IP traffic.

===================================================================

gatchat/gatppp_internal.h +7 -0

@@ -66,6 +66,13 @@
 	gpointer priv;
 };
 
+struct net_data {
+	struct ppp_link *link;
+	char *if_name;
+	GIOChannel *channel;
+	struct pppcp_data *ipcp;
+};
+
 struct auth_data {
 	guint16 proto;
 	gpointer proto_data;

gatchat/gatppp_internal.h +10 -0

+/****** IPCP support ****************/
+enum {
+	/* supported codes */
+	IPCP_SUPPORTED_CODES	= (1 << CONFIGURE_REQUEST) |
+				  (1 << CONFIGURE_ACK) |
+				  (1 << CONFIGURE_NAK) |
+				  (1 << CONFIGURE_REJECT) |
+				  (1 << TERMINATE_REQUEST) |
+				  (1 << TERMINATE_ACK) |
+				  (1 << CODE_REJECT),

gatchat/gatppp.c line 267

Quoted 5 lines

gatchat/gatppp.c new file +4 -0

+			} else {
+				/* store last flag character */
+				link->buffer[link->index++] = data[pos];
+				frame = ppp_decode(link, link->buffer);

This function along with ppp_decode do almost exactly the same thing as gsm0710_advanced_extract_frame in gsm0710.c. They both do HDLC frame decoding, and the only difference I can see is in the fcs table. Can we combine these somehow?

On Thu, 11 Mar 2010 20:17:49 -0600

Quoted 9 lines · Denis Kenzior

gatchat/gatppp.c line 267

Quoted 4 lines

gatchat/gatppp.c new file +4 -0

+			} else {
+				/* store last flag character */
+				link->buffer[link->index++] = data[pos];
+				frame = ppp_decode(link, link->buffer);

This function along with ppp_decode do almost exactly the same thing as gsm0710_advanced_extract_frame in gsm0710.c. They both do HDLC frame decoding, and the only difference I can see is in the fcs table. Can we combine these somehow?

Possibly - although in theory in addition to the escaping that you do in the gsm0710 code, we have to support a negotiated accm (which you see I've not yet implemented here). We also in theory should support PFC and ACFC (which the one modem I tested with required, otherwise it refused to ack my Configure-Request). I think there may eventually be enough differences to keep these separate.

Quoted 10 lines

gatchat/gatpppnet.c new file +10 -0

+/****** IPCP support ****************/
+enum {
+	/* supported codes */
+	IPCP_SUPPORTED_CODES	= (1 << CONFIGURE_REQUEST) |
+				  (1 << CONFIGURE_ACK) |
+				  (1 << CONFIGURE_NAK) |
+				  (1 << CONFIGURE_REJECT) |
+				  (1 << TERMINATE_REQUEST) |
+				  (1 << TERMINATE_ACK) |
+				  (1 << CODE_REJECT),

gatchat/gatpppnet.c line 214

Quoted 10 lines

gatchat/gatpppnet.c new file +10 -0

+
+	IPCP_PROTO		= 0x8021,
+
+	/* option types */
+	IP_ADDRESSES		= 1,
+	IP_COMPRESSION_PROTO	= 2,
+	IP_ADDRESS		= 3,
+	PRIMARY_DNS_SERVER	= 129,
+	SECONDARY_DNS_SERVER	= 131,
+};

I don't think enum is the right way for this. I can see it for the option types, but for IPCP_PROTO and IPCP_SUPPORTED_CODES. I would say just using simple defines is way better.

Feel free to convince me other way or show me what I have missed here.

gatchat/gsmdial.c line 234

Quoted 6 lines

gatchat/gsmdial.c +5 -0

+static void print_ip_address(guint32 ip_addr)
+{
+	struct in_addr addr;
+	addr.s_addr = ip_addr;
+	g_print("%s\n", inet_ntoa(addr));

It is just fine to use printf() like everybody else. The g_print function is pretty much stupid idea from GLib. Same as gchar should not be used either.

The only case where g_print makes sense is in GLib based unit tests.

Quoted 25 lines

Quoted 10 lines

gatchat/gatpppnet.c new file +10 -0

+/****** IPCP support ****************/
+enum {
+	/* supported codes */
+	IPCP_SUPPORTED_CODES	= (1 << CONFIGURE_REQUEST) |
+				  (1 << CONFIGURE_ACK) |
+				  (1 << CONFIGURE_NAK) |
+				  (1 << CONFIGURE_REJECT) |
+				  (1 << TERMINATE_REQUEST) |
+				  (1 << TERMINATE_ACK) |
+				  (1 << CODE_REJECT),

gatchat/gatpppnet.c line 214

Quoted 10 lines

gatchat/gatpppnet.c new file +10 -0

+
+	IPCP_PROTO		= 0x8021,
+
+	/* option types */
+	IP_ADDRESSES		= 1,
+	IP_COMPRESSION_PROTO	= 2,
+	IP_ADDRESS		= 3,
+	PRIMARY_DNS_SERVER	= 129,
+	SECONDARY_DNS_SERVER	= 131,
+};

I don't think enum is the right way for this. I can see it for the option types, but for IPCP_PROTO and IPCP_SUPPORTED_CODES. I would say just using simple defines is way better.

Quoted 1 line

Feel free to convince me other way or show me what I have missed here.

It's mostly just a habit, but in general there are advantages to using enum vs. a define. You are assured that the scope is kept local, even if you are uncreative with your name choices, whereas with a macro it is not. Also it's sometimes easier to debug with an enum vs. a macro. I can certainly change it if you really want me too.