Refactor GAtChat to accept user-provided parsers

Intended for really broken modems.  A default 27.007 compliant
parser is provided.

1 files changed, 228 insertions, 0 deletions

diff --git a/gatchat/gatsyntax.c b/gatchat/gatsyntax.c
new file mode 100644
index 00000000..7c5aadce
--- /dev/null
+++ b/gatchat/gatsyntax.c
@@ -0,0 +1,228 @@
+/*
+ *
+ *  AT chat library with GLib integration
+ *
+ *  Copyright (C) 2008-2009  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 <glib.h>
+
+#include "gatsyntax.h"
+
+enum GSMV1_STATE_ {
+	GSMV1_STATE_IDLE = 0,
+	GSMV1_STATE_INITIAL_CR,
+	GSMV1_STATE_INITIAL_LF,
+	GSMV1_STATE_RESPONSE,
+	GSMV1_STATE_TERMINATOR_CR,
+	GSMV1_STATE_GUESS_MULTILINE_RESPONSE,
+	GSMV1_STATE_MULTILINE_RESPONSE,
+	GSMV1_STATE_MULTILINE_TERMINATOR_CR,
+	GSMV1_STATE_PDU,
+	GSMV1_STATE_PDU_CR,
+	GSMV1_STATE_PROMPT,
+	GSMV1_STATE_GARBAGE,
+	GSMV1_STATE_GARBAGE_CHECK_LF,
+};
+
+static void gsmv1_hint(GAtSyntax *syntax, GAtSyntaxExpectHint hint)
+{
+	switch (hint) {
+	case G_AT_SYNTAX_EXPECT_PDU:
+		syntax->state = GSMV1_STATE_PDU;
+		break;
+	case G_AT_SYNTAX_EXPECT_MULTILINE:
+		syntax->state = GSMV1_STATE_GUESS_MULTILINE_RESPONSE;
+		break;
+	default:
+		break;
+	};
+}
+
+static GAtSyntaxResult gsmv1_feed(GAtSyntax *syntax,
+					const char *bytes, gsize *len)
+{
+	gsize i = 0;
+	GAtSyntaxResult res = G_AT_SYNTAX_RESULT_UNSURE;
+
+	while (i < *len) {
+		char byte = bytes[i];
+
+		switch (syntax->state) {
+		case GSMV1_STATE_IDLE:
+			if (byte == '\r')
+				syntax->state = GSMV1_STATE_INITIAL_CR;
+			else
+				syntax->state = GSMV1_STATE_GARBAGE;
+			break;
+
+		case GSMV1_STATE_INITIAL_CR:
+			if (byte == '\n')
+				syntax->state = GSMV1_STATE_INITIAL_LF;
+			else
+				syntax->state = GSMV1_STATE_GARBAGE;
+			break;
+
+		case GSMV1_STATE_INITIAL_LF:
+			if (byte == '\r')
+				syntax->state = GSMV1_STATE_TERMINATOR_CR;
+			else if (byte == '>')
+				syntax->state = GSMV1_STATE_PROMPT;
+			else
+				syntax->state = GSMV1_STATE_RESPONSE;
+			break;
+
+		case GSMV1_STATE_RESPONSE:
+			if (byte == '\r')
+				syntax->state = GSMV1_STATE_TERMINATOR_CR;
+			break;
+
+		case GSMV1_STATE_TERMINATOR_CR:
+			syntax->state = GSMV1_STATE_IDLE;
+
+			if (byte == '\n') {
+				i += 1;
+				res = G_AT_SYNTAX_RESULT_LINE;
+			} else
+				res = G_AT_SYNTAX_RESULT_UNRECOGNIZED;
+
+			goto out;
+
+		case GSMV1_STATE_GUESS_MULTILINE_RESPONSE:
+			if (byte == '\r')
+				syntax->state = GSMV1_STATE_INITIAL_CR;
+			else
+				syntax->state = GSMV1_STATE_MULTILINE_RESPONSE;
+			break;
+
+		case GSMV1_STATE_MULTILINE_RESPONSE:
+			if (byte == '\r')
+				syntax->state = GSMV1_STATE_MULTILINE_TERMINATOR_CR;
+			break;
+
+		case GSMV1_STATE_MULTILINE_TERMINATOR_CR:
+			syntax->state = GSMV1_STATE_IDLE;
+
+			if (byte == '\n') {
+				i += 1;
+				res = G_AT_SYNTAX_RESULT_MULTILINE;
+			} else
+				res = G_AT_SYNTAX_RESULT_UNRECOGNIZED;
+
+			goto out;
+
+		case GSMV1_STATE_PDU:
+			if (byte == '\r')
+				syntax->state = GSMV1_STATE_PDU_CR;
+			break;
+
+		case GSMV1_STATE_PDU_CR:
+			syntax->state = GSMV1_STATE_IDLE;
+
+			if (byte == '\n') {
+				i += 1;
+				res = G_AT_SYNTAX_RESULT_PDU;
+			} else
+				res = G_AT_SYNTAX_RESULT_UNRECOGNIZED;
+
+			goto out;
+
+		case GSMV1_STATE_PROMPT:
+			if (byte == ' ') {
+				syntax->state = GSMV1_STATE_IDLE;
+				i += 1;
+				res = G_AT_SYNTAX_RESULT_PROMPT;
+				goto out;
+			}
+
+			syntax->state = GSMV1_STATE_RESPONSE;
+			return G_AT_SYNTAX_RESULT_UNSURE;
+
+		case GSMV1_STATE_GARBAGE:
+			if (byte == '\r')
+				syntax->state = GSMV1_STATE_GARBAGE_CHECK_LF;
+			break;
+
+		case GSMV1_STATE_GARBAGE_CHECK_LF:
+			syntax->state = GSMV1_STATE_IDLE;
+			res = G_AT_SYNTAX_RESULT_UNRECOGNIZED;
+
+			if (byte == '\n')
+				i += 1;
+
+			goto out;
+
+		default:
+			break;
+		};
+
+		i += 1;
+	}
+
+out:
+	*len = i;
+	return res;
+}
+
+GAtSyntax *g_at_syntax_new_full(GAtSyntaxFeedFunc feed,
+					GAtSyntaxSetHintFunc hint,
+					int initial_state)
+{
+	GAtSyntax *syntax;
+
+	syntax = g_new0(GAtSyntax, 1);
+
+	syntax->feed = feed;
+	syntax->set_hint = hint;
+	syntax->state = initial_state;
+	syntax->ref_count = 1;
+
+	return syntax;
+}
+
+
+GAtSyntax *g_at_syntax_new_gsmv1()
+{
+	return g_at_syntax_new_full(gsmv1_feed, gsmv1_hint, GSMV1_STATE_IDLE);
+}
+
+GAtSyntax *g_at_syntax_ref(GAtSyntax *syntax)
+{
+	if (syntax == NULL)
+		return NULL;
+
+	g_atomic_int_inc(&syntax->ref_count);
+
+	return syntax;
+}
+
+void g_at_syntax_unref(GAtSyntax *syntax)
+{
+	gboolean is_zero;
+
+	if (syntax == NULL)
+		return;
+
+	is_zero = g_atomic_int_dec_and_test(&syntax->ref_count);
+
+	if (is_zero)
+		g_free(syntax);
+}