gprs: Create a gprs_utils file and move to be shared code in there

We intend to move some of these routines to libosmocore but to avoid
a feature symbol clash we are prefixing these routines with gprs_.

Done with Jacob

1 files changed, 152 insertions, 0 deletions

diff --git a/openbsc/src/gprs/gprs_utils.c b/openbsc/src/gprs/gprs_utils.c
new file mode 100644
index 000000000..8b82f2506
--- /dev/null
+++ b/openbsc/src/gprs/gprs_utils.c
@@ -0,0 +1,152 @@
+/* GPRS utility functions */
+
+/* (C) 2010 by Harald Welte <laforge@gnumonks.org>
+ * (C) 2010-2014 by On-Waves
+ * (C) 2013 by Holger Hans Peter Freyther
+ * All Rights Reserved
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * 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 Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+#include <openbsc/gprs_utils.h>
+
+#include <osmocom/core/msgb.h>
+#include <osmocom/gprs/gprs_ns.h>
+
+#include <string.h>
+
+/* FIXME: this needs to go to libosmocore/msgb.c */
+struct msgb *gprs_msgb_copy(const struct msgb *msg, const char *name)
+{
+	struct libgb_msgb_cb *old_cb, *new_cb;
+	struct msgb *new_msg;
+
+	new_msg = msgb_alloc(msg->data_len, name);
+	if (!new_msg)
+		return NULL;
+
+	/* copy data */
+	memcpy(new_msg->_data, msg->_data, new_msg->data_len);
+
+	/* copy header */
+	new_msg->len = msg->len;
+	new_msg->data += msg->data - msg->_data;
+	new_msg->head += msg->head - msg->_data;
+	new_msg->tail += msg->tail - msg->_data;
+
+	new_msg->l1h = new_msg->_data + (msg->l1h - msg->_data);
+	new_msg->l2h = new_msg->_data + (msg->l2h - msg->_data);
+	new_msg->l3h = new_msg->_data + (msg->l3h - msg->_data);
+	new_msg->l4h = new_msg->_data + (msg->l4h - msg->_data);
+
+	/* copy GB specific data */
+	old_cb = LIBGB_MSGB_CB(msg);
+	new_cb = LIBGB_MSGB_CB(new_msg);
+
+	new_cb->bssgph = new_msg->_data + (old_cb->bssgph - msg->_data);
+	new_cb->llch = new_msg->_data + (old_cb->llch - msg->_data);
+
+	/* bssgp_cell_id is a pointer into the old msgb, so we need to make
+	 * it a pointer into the new msgb */
+	new_cb->bssgp_cell_id = new_msg->_data + (old_cb->bssgp_cell_id - msg->_data);
+	new_cb->nsei = old_cb->nsei;
+	new_cb->bvci = old_cb->bvci;
+	new_cb->tlli = old_cb->tlli;
+
+	return new_msg;
+}
+
+/* TODO: Move this to libosmocore/msgb.c */
+int gprs_msgb_resize_area(struct msgb *msg, uint8_t *area,
+			    size_t old_size, size_t new_size)
+{
+	int rc;
+	uint8_t *rest = area + old_size;
+	int rest_len = msg->len - old_size - (area - msg->data);
+	int delta_size = (int)new_size - (int)old_size;
+
+	if (delta_size == 0)
+		return 0;
+
+	if (delta_size > 0) {
+		rc = msgb_trim(msg, msg->len + delta_size);
+		if (rc < 0)
+			return rc;
+	}
+
+	memmove(area + new_size, area + old_size, rest_len);
+
+	if (msg->l1h >= rest)
+		msg->l1h += delta_size;
+	if (msg->l2h >= rest)
+		msg->l2h += delta_size;
+	if (msg->l3h >= rest)
+		msg->l3h += delta_size;
+	if (msg->l4h >= rest)
+		msg->l4h += delta_size;
+
+	if (delta_size < 0)
+		msgb_trim(msg, msg->len + delta_size);
+
+	return 0;
+}
+
+/* TODO: Move these conversion functions to a utils file. */
+char * gprs_apn_to_str(char *out_str, const uint8_t *apn_enc, size_t rest_chars)
+{
+	char *str = out_str;
+
+	while (rest_chars > 0 && apn_enc[0]) {
+		size_t label_size = apn_enc[0];
+		if (label_size + 1 > rest_chars)
+			return NULL;
+
+		memmove(str, apn_enc + 1, label_size);
+		str += label_size;
+		rest_chars -= label_size + 1;
+		apn_enc += label_size + 1;
+
+		if (rest_chars)
+			*(str++) = '.';
+	}
+	str[0] = '\0';
+
+	return out_str;
+}
+
+int gprs_str_to_apn(uint8_t *apn_enc, const char *str, size_t max_chars)
+{
+	uint8_t *last_len_field = apn_enc;
+	int len = 1;
+	apn_enc += 1;
+
+	while (str[0]) {
+		if (str[0] == '.') {
+			*last_len_field = (apn_enc - last_len_field) - 1;
+			last_len_field = apn_enc;
+		} else {
+			*apn_enc = str[0];
+		}
+		apn_enc += 1;
+		str += 1;
+		len += 1;
+		if (len > max_chars)
+			return -1;
+	}
+
+	*last_len_field = (apn_enc - last_len_field) - 1;
+
+	return len;
+}
+