[gprs] SGSN: Expect all Identifiers to be stored at highest level
We now expect the highest level (actual SGSN GMM code) to know
all identifiers for every element in the protocol stack, i.e.
TLLI, SAPI, BVCI and NSEI. The layer-inetrnal state is looked
up based on those identifiers.
The reason for this is to ensure only the highest level state
needs to be persistent, while everything else can be regenerated
dynamically (e.g. in a SGSN restart)
diff --git a/openbsc/src/gprs_llc.c b/openbsc/src/gprs_llc.c
index 883eedb..ba031a2 100644
--- a/openbsc/src/gprs_llc.c
+++ b/openbsc/src/gprs_llc.c
@@ -61,6 +61,10 @@
unsigned int n200;
unsigned int retrans_ctr;
+
+ /* over which BSSGP BTS ctx do we need to transmit */
+ uint16_t bvci;
+ uint16_t nsei;
};
static LLIST_HEAD(gprs_llc_lles);
@@ -190,11 +194,22 @@
/* Transmit a UI frame over the given SAPI */
int gprs_llc_tx_ui(struct msgb *msg, u_int8_t sapi, int command)
{
+ struct gprs_llc_lle *lle;
u_int8_t *fcs, *llch;
u_int8_t addr, ctrl[2];
u_int32_t fcs_calc;
u_int16_t nu = 0;
+ /* Identifiers from UP: (TLLI, SAPI) + (BVCI, NSEI) */
+
+ /* look-up or create the LL Entity for this (TLLI, SAPI) tuple */
+ lle = lle_by_tlli_sapi(msgb_tlli(msg), sapi);
+ if (!lle)
+ lle = lle_alloc(msgb_tlli(msg), sapi);
+ /* Update LLE's (BVCI, NSEI) tuple */
+ lle->bvci = msgb_bvci(msg);
+ lle->nsei = msgb_nsei(msg);
+
/* Address Field */
addr = sapi & 0xf;
if (command)
@@ -219,6 +234,8 @@
fcs[1] = (fcs_calc >> 8) & 0xff;
fcs[2] = (fcs_calc >> 16) & 0xff;
+ /* Identifiers passed down: (BVCI, NSEI) */
+
return gprs_bssgp_tx_dl_ud(msg);
}