xua_msg: Add xua_msg_free_tag() and xua_msg_copy_part()

... also, mark input to xua_msg_find_tag as 'const' pointer.

Change-Id: I083634db9c3606bcff87700f253054a38a20816d

2 files changed, 31 insertions, 2 deletions

diff --git a/include/osmocom/sigtran/xua_msg.h b/include/osmocom/sigtran/xua_msg.h
index 2a6e3ae..23f92c5 100644
--- a/include/osmocom/sigtran/xua_msg.h
+++ b/include/osmocom/sigtran/xua_msg.h
@@ -50,7 +50,10 @@ void xua_msg_free(struct xua_msg *msg);
 
 int xua_msg_add_data(struct xua_msg *msg, uint16_t tag, uint16_t len, uint8_t *dat);
 
-struct xua_msg_part *xua_msg_find_tag(struct xua_msg *msg, uint16_t tag);
+struct xua_msg_part *xua_msg_find_tag(const struct xua_msg *msg, uint16_t tag);
+int xua_msg_free_tag(struct xua_msg *xua, uint16_t tag);
+int xua_msg_copy_part(struct xua_msg *xua_out, uint16_t tag_out,
+		      const struct xua_msg *xua_in, uint16_t tag_in);
 
 struct xua_msg *xua_from_msg(const int version, uint16_t len, uint8_t *data);
 struct msgb *xua_to_msg(const int version, struct xua_msg *msg);
diff --git a/src/xua_msg.c b/src/xua_msg.c
index 4a3e013..71511a9 100644
--- a/src/xua_msg.c
+++ b/src/xua_msg.c
@@ -77,7 +77,7 @@ int xua_msg_add_data(struct xua_msg *msg, uint16_t tag,
 	return 0;
 }
 
-struct xua_msg_part *xua_msg_find_tag(struct xua_msg *xua, uint16_t tag)
+struct xua_msg_part *xua_msg_find_tag(const struct xua_msg *xua, uint16_t tag)
 {
 	struct xua_msg_part *part;
 
@@ -88,6 +88,32 @@ struct xua_msg_part *xua_msg_find_tag(struct xua_msg *xua, uint16_t tag)
 	return NULL;
 }
 
+int xua_msg_free_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) {
+			llist_del(&part->entry);
+			talloc_free(part);
+			return 1;
+		}
+	}
+	return 0;
+}
+
+int xua_msg_copy_part(struct xua_msg *xua_out, uint16_t tag_out,
+		      const struct xua_msg *xua_in, uint16_t tag_in)
+{
+	const struct xua_msg_part *part;
+
+	part = xua_msg_find_tag(xua_in, tag_in);
+	if (!part)
+		return -1;
+
+	return xua_msg_add_data(xua_out, tag_out, part->len, part->dat);
+}
+
 struct xua_msg *xua_from_msg(const int version, uint16_t len, uint8_t *data)
 {
 	struct xua_parameter_hdr *par;