1 files changed, 278 insertions, 0 deletions
diff --git a/gsmdecode/src/gsmdecode.c b/gsmdecode/src/gsmdecode.c
new file mode 100644
index 0000000..a2456d3
--- /dev/null
+++ b/gsmdecode/src/gsmdecode.c
@@ -0,0 +1,278 @@
+#include "common.h"
+#include <stdio.h>
+#include <ctype.h>
+#include <string.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include "data_out.h"
+
+/*
+ * B: 112, 176, 128
+ * Bbis: 96, 80, 
+ */
+
+#if 0
+- if there is layer 2 always use layer 2 (BBIS!)
+- if there is layer 1 but no layer 2 then generate layer2 from l1! (BBIS!)
+
+or
+
+- if there is layer1 use layer 1
+- if there is layer2 but no layer 1 generate layer1 msg
+#endif
+
+struct _opt opt;
+
+struct _ch_info
+{
+	unsigned char flags;
+	int logical;
+	int physical;
+	int fn;
+	unsigned char data[23];
+	int data_len;
+};
+
+#define FL_CH_UP		(0x01)
+#define FL_CH_DOWN		(0x02)
+
+static int hex2bin(unsigned char *out, unsigned char *in);
+
+static void
+usage(char *str)
+{
+	fprintf(stderr,
+"Usage: gsmdecode [ options ]\n"
+" Raw hex input: It decodes one line at a time. The input format should look\n"
+" like this:\n"
+" 00 01 02 03 04 05 2b 2b 2b 2b 2b 2b 2b ...\n"
+" Nokia DCT3 trace debug input (XML) is supported with the -x option.\n"
+"\n"
+" Options:\n"
+"   -h  This message\n"
+"   -b  Force Format B (e.g. raw hex SDCCH)\n"
+"   -i  Force Format Bbis (e.g. raw hex BCCH)\n"
+"   -x  Force OpenGPA xml input format [default]\n"
+"   -m  Accept Motorola input (experimental)\n"
+"");
+
+	if (str)
+	{
+		fprintf(stderr, str);
+		exit(-1);
+	}
+	exit(0);
+}
+
+static int
+xml_get_int(int *val, const unsigned char *str, const unsigned char *pattern)
+{
+	char *ptr;
+	char *start, *end;
+	char buf[32];
+
+	ptr = strstr((char *)str, (char *)pattern);
+	if (ptr == NULL)
+		return -1;
+	start = strchr(ptr, '"');
+	if (start == NULL)
+		return -2;
+	start++;
+	end = strchr(start, '"');
+	if (end == NULL)
+		return -3;
+
+	memcpy(buf, start, end - start);
+	buf[end - start] = '\0';
+	*val = atoi(buf);
+	return 0;
+}
+
+/*
+ * - if there is layer1 use layer 1
+ * - if there is layer2 but no layer 1 generate layer1 msg
+ * Return -1 if no structure has been found.
+ */
+static int
+xml_in(struct _ch_info *chinfo, unsigned char *str)
+{
+	unsigned char *dst;
+	char *ptr;
+	int len;
+	int layer = 0;
+
+	if (memcmp(str, "<l1 ", 4) == 0)
+	{
+		memset(chinfo, 0, sizeof *chinfo);
+		memset(chinfo->data, 0x2b, sizeof chinfo->data);
+		layer = 1;
+	} else if (memcmp(str, "<l2 ", 4) == 0) {
+		/* If layer2 exists but layer1 also then do not decode
+		 * layer2 again.
+		 */
+		if (chinfo->data_len > 0)
+			return -1;
+		layer = 2;
+	} else
+		return -1;
+
+	/* First read all kind of meta information (logical channel, fn, ..) */
+	xml_get_int(&chinfo->logical, str, (const unsigned char *)"logicalchannel");
+//		fprintf(stderr, "logical %u\n", chinfo->logical);
+
+	/* Last see if there is a data="..." section. if so convert it into
+	 * binary and prefix it with pseudo length and up/down indicator
+	 * if required
+	 */
+	ptr = strstr((char *)str, "data=\"");
+	/* Return 0 (true) here so that caller can decide if data_len
+	 * contains other data to decode them...
+	 * (This can happen if there is l1 but no l2 data)
+	 */
+	if (ptr == NULL)
+		return 0;
+
+	ptr += 6;
+	dst = chinfo->data;
+	/* For layer 2 the xml input is missing the length data */
+	/* We prefix it! */
+	if (layer == 2)
+	{
+		/* HERE: Layer 1 missing, layer 2 available */
+		if ((chinfo->logical ==  112) || (chinfo->logical == 176) || (chinfo->logical == 128))
+		{
+			/* B header */
+			memcpy(dst, "\x01\x01", 3);
+			chinfo->data_len = 3;
+		} else {
+			/* BBis header */
+			chinfo->data_len = 1;
+		}
+		dst += chinfo->data_len;
+	}
+	
+	len = hex2bin(dst, (unsigned char *)ptr);
+	if (len <= 0)
+		return -3;
+	chinfo->data_len += len;
+	/* If layer 2 exist but not layer1 then we add a fake header */
+	if (layer == 2)
+		*(dst - 1) = len << 2;
+
+	return 0;
+}
+
+static void
+init_defaults()
+{
+	opt.format = MSG_FORMAT_XML;
+}
+
+static void
+do_getopt(int argc, char *argv[])
+{
+	int c;
+
+	while ((c = getopt(argc, argv, "hbixm")) != -1)
+	{
+		switch (c)
+		{
+		case 'm':
+			opt.flags |= FL_MOTOROLA;
+			break;
+		case 'x':
+			opt.format = MSG_FORMAT_XML;
+			break;
+		case 'b':
+			opt.format = MSG_FORMAT_B;
+			break;
+		case 'i':
+			opt.format = MSG_FORMAT_BBIS;
+			break;
+		case 'h':
+		default:
+			usage(NULL);
+		}
+
+	}
+}
+
+static int
+hc2b(unsigned char hex)
+{
+	hex = tolower(hex);
+	if ((hex >= '0') && (hex <= '9'))
+		return hex - '0';
+	if ((hex >= 'a') && (hex <= 'f'))
+		return hex - 'a' + 10;
+	return -1;
+}
+
+static int
+hex2bin(unsigned char *out, unsigned char *in)
+{
+	unsigned char *out_start = out;
+	unsigned char *end = in + strlen((char *)in);
+	int is_low = 0;
+	int c;
+
+	while (in < end)
+	{
+		c = hc2b(in[0]);
+		if (c < 0)
+		{
+			in++;
+			continue;
+		}
+		if (is_low == 0)
+		{
+			out[0] = c << 4;
+			is_low = 1;
+		} else {
+			out[0] |= (c & 0x0f);
+			is_low = 0;
+			out++;
+		}
+		in++;
+	}
+
+	return out - out_start;
+}
+
+int
+main(int argc, char *argv[])
+{
+	unsigned char buf[1024];
+	unsigned char bin[sizeof buf / 2 + 1];
+	int len;
+	struct _ch_info chi;
+
+	init_defaults();
+	do_getopt(argc, argv);
+	while (fgets((char *)buf, sizeof buf, stdin) != NULL)
+	{
+		if (opt.format == MSG_FORMAT_XML)
+		{
+			if (xml_in(&chi, buf) != 0)
+				continue;
+			if (chi.data_len <= 0)
+				continue;
+			if ((chi.logical ==  112) || (chi.logical == 176) || (chi.logical == 128))
+				l2_data_out_B(0, chi.data, chi.data_len);
+			else
+				l2_data_out_Bbis(0, chi.data, chi.data_len);
+
+			continue;
+		}
+		memset(bin, 0, sizeof bin);
+		len = hex2bin(bin, buf);
+		if (opt.format == MSG_FORMAT_B)
+			l2_data_out_B(0, bin, len);
+		else
+			l2_data_out_Bbis(0, bin, len);
+	}
+
+	exit(0);
+	return 0;
+}
+