host: use autotools and split shared code to libosmo-simtrace2

Change-Id: I57e77f927ee9e169cc794c5dc6b128a2d590201b

host/lib/gsmtap.c

@@ -0,0 +1,57 @@
+#include <osmocom/simtrace2/gsmtap.h>
+
+#include <osmocom/core/gsmtap.h>
+#include <osmocom/core/gsmtap_util.h>
+
+#include <errno.h>
+#include <string.h>
+#include <unistd.h>
+#include <stdio.h>
+
+/* global GSMTAP instance */
+static struct gsmtap_inst *g_gti;
+
+int osmo_st2_gsmtap_init(const char *gsmtap_host)
+{
+	if (g_gti)
+		return -EEXIST;
+
+	g_gti = gsmtap_source_init(gsmtap_host, GSMTAP_UDP_PORT, 0);
+	if (!g_gti) {
+		perror("unable to open GSMTAP");
+		return -EIO;
+	}
+	gsmtap_source_add_sink(g_gti);
+
+	return 0;
+}
+
+int osmo_st2_gsmtap_send_apdu(uint8_t sub_type, const uint8_t *apdu, unsigned int len)
+{
+	struct gsmtap_hdr *gh;
+	unsigned int gross_len = len + sizeof(*gh);
+	uint8_t *buf = malloc(gross_len);
+	int rc;
+
+	if (!buf)
+		return -ENOMEM;
+
+	memset(buf, 0, sizeof(*gh));
+	gh = (struct gsmtap_hdr *) buf;
+	gh->version = GSMTAP_VERSION;
+	gh->hdr_len = sizeof(*gh)/4;
+	gh->type = GSMTAP_TYPE_SIM;
+	gh->sub_type = sub_type;
+
+	memcpy(buf + sizeof(*gh), apdu, len);
+
+	rc = write(gsmtap_inst_fd(g_gti), buf, gross_len);
+	if (rc < 0) {
+		perror("write gsmtap");
+		free(buf);
+		return rc;
+	}
+
+	free(buf);
+	return 0;
+}