libmsc/gsm_04_11.c: clarify implicit CP-ACK handling

Change-Id: I3c5327a5019590c65d0ccb33a52f07b3988ea952
This commit is contained in:
Vadim Yanitskiy 2019-04-14 18:34:18 +07:00
parent baccf3a74b
commit 03e8754960
1 changed files with 6 additions and 4 deletions

View File

@ -1238,11 +1238,13 @@ int gsm0411_rcv_sms(struct ran_conn *conn,
LOG_TRANS(trans, LOGL_DEBUG, "receiving SMS message %s\n",
gsm48_pdisc_msgtype_name(gsm48_hdr_pdisc(gh), gsm48_hdr_msg_type(gh)));
/* 5.4: For MO, if a CP-DATA is received for a new
* transaction, equals reception of an implicit
* last CP-ACK for previous transaction */
/* According to section 5.3.4, due to structure of message flow on
* SAPI 0 and 3 it is possible that the CP-ACK of a short message
* transfer might not be received. In this case the reception of
* CP-DATA may be interpreted as the reception of the awaited
* CP-ACK (implicit) and CP-DATA message. */
if (trans->sms.smc_inst.cp_state == GSM411_CPS_IDLE
&& msg_type == GSM411_MT_CP_DATA) {
&& msg_type == GSM411_MT_CP_DATA) {
int i;
struct gsm_trans *ptrans;