xua: Generalize the m2ua_msg and call it xua_msg

Generalize, this requires various API modifications
but that is the most sane path forward.

1 files changed, 184 insertions, 0 deletions

diff --git a/src/xua_msg.c b/src/xua_msg.c
new file mode 100644
index 0000000..e10b942
--- /dev/null
+++ b/src/xua_msg.c
@@ -0,0 +1,184 @@
+/* Routines for generating and parsing messages */
+/* (C) 2011 by Holger Hans Peter Freyther <zecke@selfish.org>
+ *
+ * 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 <sigtran/xua_msg.h>
+
+#include <osmocom/core/msgb.h>
+#include <osmocom/core/logging.h>
+#include <osmocom/core/talloc.h>
+
+#include <arpa/inet.h>
+
+#include <string.h>
+
+static void *tall_xua;
+static int DXUA = -1;
+
+struct xua_msg *xua_msg_alloc(void)
+{
+	struct xua_msg *msg;
+
+	msg = talloc_zero(tall_xua, struct xua_msg);
+	if (!msg) {
+		LOGP(DXUA, LOGL_ERROR, "Failed to allocate.\n");
+		return NULL;
+	}
+
+	INIT_LLIST_HEAD(&msg->headers);
+	return msg;
+}
+
+void xua_msg_free(struct xua_msg *msg)
+{
+	talloc_free(msg);
+}
+
+int xua_msg_add_data(struct xua_msg *msg, uint16_t tag,
+		      uint16_t len, uint8_t *dat)
+{
+	struct xua_msg_part *part;
+
+	part = talloc_zero(msg, struct xua_msg_part);
+	if (!part)
+		return -1;
+
+	part->tag = tag;
+	part->len = len;
+
+	/* do we have any data? */
+	if (part->len != 0) {
+		part->dat = talloc_memdup(part, dat, len);
+		if (!part->dat) {
+			talloc_free(part);
+			return -1;
+		}
+	}
+
+	llist_add_tail(&part->entry, &msg->headers);
+	return 0;
+}
+
+struct xua_msg_part *xua_msg_find_tag(struct xua_msg *xua, uint16_t tag)
+{
+	struct xua_msg_part *part;
+
+	llist_for_each_entry(part, &xua->headers, entry)
+		if (part->tag == tag)
+			return part;
+
+	return NULL;
+}
+
+struct xua_msg *xua_from_msg(const int version, uint16_t len, uint8_t *data)
+{
+	struct xua_parameter_hdr *par;
+	struct xua_common_hdr *hdr;
+	struct xua_msg *msg;
+	uint16_t pos, par_len, padding;
+	int rc;
+
+	msg = xua_msg_alloc();
+	if (!msg)
+		return NULL;
+
+	if (len < sizeof(*hdr))
+		goto fail;
+
+	hdr = (struct xua_common_hdr *) data;
+	if (hdr->version != version)
+		goto fail;
+	if (ntohl(hdr->msg_length) > len)
+		goto fail;
+
+	msg->hdr = *hdr;
+	pos = sizeof(*hdr);
+
+	while (pos + sizeof(*par) < len) {
+		par = (struct xua_parameter_hdr *) &data[pos];
+		par_len = ntohs(par->len);
+
+		if (pos + par_len > len || par_len < 4) 
+			goto fail;
+
+		rc = xua_msg_add_data(msg, ntohs(par->tag),
+				       par_len - 4, par->data);
+		if (rc != 0)
+			goto fail;
+
+		pos += par_len;
+
+		/* move over the padding */
+		padding = (4 - (par_len % 4)) & 0x3;
+		pos += padding;
+	}
+
+	/* TODO: parse */
+	return msg;
+
+fail:
+	LOGP(DXUA, LOGL_ERROR, "Failed to parse.\n");
+	xua_msg_free(msg);
+	return NULL;
+}
+
+struct msgb *xua_to_msg(const int version, struct xua_msg *xua)
+{
+	struct xua_msg_part *part;
+	struct xua_common_hdr *hdr;
+	struct msgb *msg;
+	uint8_t rest;
+
+	msg = msgb_alloc_headroom(2048, 512, "xua msg");
+	if (!msg) {
+		LOGP(DXUA, LOGL_ERROR, "Failed to allocate.\n");
+		return NULL;
+	}
+
+	msg->l2h = msgb_put(msg, sizeof(*hdr));
+	hdr = (struct xua_common_hdr *) msg->l2h;
+	memcpy(hdr, &xua->hdr, sizeof(*hdr));
+
+	/* make sure that is right */
+	hdr->version = version;
+	hdr->spare = 0;
+
+	llist_for_each_entry(part, &xua->headers, entry) {
+		msgb_put_u16(msg, part->tag);
+		msgb_put_u16(msg, part->len + 4);
+		if (part->dat) {
+			uint8_t *dat = msgb_put(msg, part->len);
+			memcpy(dat, part->dat, part->len);
+
+			/* padding */
+			rest = (4 - (part->len % 4)) & 0x3;
+			if (rest > 0) {
+				dat = msgb_put(msg, rest);
+				memset(dat, 0, rest);
+			}
+		}
+	}
+
+	/* update the size of the data */
+	hdr->msg_length = htonl(msgb_l2len(msg));
+	return msg;
+}
+
+void xua_set_log_area(int log_area)
+{
+	DXUA = log_area;
+}