hnbgw: Avoid allocating SCCP conn id >0x00fffffe

This fixes bug in use of M3UA/SCCP after 2**24 connection IDs have been
allocated.

Related: SYS#6211
Change-Id: I03bad960f65fbff6e467def5bba60fefb328f962
This commit is contained in:
Pau Espin 2022-11-23 17:27:04 +01:00
parent 0589c3ecf1
commit 61021881ac
1 changed files with 14 additions and 1 deletions

View File

@ -58,8 +58,21 @@ static int alloc_cn_conn_id(struct hnbgw_cnlink *cn, uint32_t *id_out)
uint32_t i;
uint32_t id;
for (i = 0; i < 0xffffffff; i++) {
/* SUA: RFC3868 sec 3.10.4:
* The source reference number is a 4 octet long integer.
* This is allocated by the source SUA instance.
* M3UA/SCCP: ITU-T Q.713 sec 3.3:
* The "source local reference" parameter field is a three-octet field containing a
* reference number which is generated and used by the local node to identify the
* connection section after the connection section is set up.
* The coding "all ones" is reserved for future use.
* Hence, let's simply use 24 bit ids to fit all link types (excluding 0x00ffffff).
*/
for (i = 0; i < 0x00ffffff; i++) {
id = cn->next_conn_id++;
if (cn->next_conn_id == 0x00ffffff)
cn->next_conn_id = 0;
if (!cn_id_in_use(cn, id)) {
*id_out = id;
return 1;