libosmogb: Port BSSGP flow control from openbsc/laforge/bssgp_fc branch
This code is supposed to implement the BSSGP flow control algorithm,
both for the per-BSS and for the per-MS flow control.
The code currently has no test cases, they will come in a separate
commit.
diff --git a/include/osmocom/gprs/gprs_bssgp.h b/include/osmocom/gprs/gprs_bssgp.h
index 8ca42bf..0646ff7 100644
--- a/include/osmocom/gprs/gprs_bssgp.h
+++ b/include/osmocom/gprs/gprs_bssgp.h
@@ -2,6 +2,8 @@
#define _GPRS_BSSGP_H
#include <stdint.h>
+#include <osmocom/core/timer.h>
+#include <osmocom/core/linuxlist.h>
#include <osmocom/gsm/gsm48.h>
#include <osmocom/gsm/prim.h>
@@ -54,6 +56,25 @@
/* gprs_bssgp.c */
+/*! \brief BSSGP flow control (SGSN side) According to Section 8.2 */
+struct bssgp_flow_control {
+ uint32_t bucket_size_max; /*!< maximum size of the bucket */
+ uint32_t bucket_leak_rate; /*!< leak rate of the bucket */
+
+ uint32_t bucket_counter; /*!< number of tokens in the bucket */
+ struct timeval time_last_pdu; /*!< timestamp of last PDU sent */
+
+ /* the built-in queue */
+ uint32_t max_queue_depth; /*!< how many packets to queue */
+ uint32_t queue_depth; /*!< current length of queue */
+ struct llist_head queue; /*!< linked list of msgb's */
+ struct osmo_timer_list timer; /*!< timer-based dequeueing */
+
+ /*! callback to be called at output of flow control */
+ int (*out_cb)(struct bssgp_flow_control *fc, struct msgb *msg,
+ uint32_t llc_pdu_len, void *priv);
+};
+
#define BVC_S_BLOCKED 0x0001
/* The per-BTS context that we keep on the SGSN side of the BSSGP link */
@@ -72,6 +93,10 @@
struct rate_ctr_group *ctrg;
+ struct bssgp_flow_control fc;
+ uint32_t bmax_default_ms;
+ uint32_t r_default_ms;
+
/* we might want to add this as a shortcut later, avoiding the NSVC
* lookup for every packet, similar to a routing cache */
//struct gprs_nsvc *nsvc;
@@ -109,6 +134,7 @@
struct bssgp_dl_ud_par {
uint32_t *tlli;
char *imsi;
+ struct bssgp_flow_control *fc;
uint16_t drx_parms;
/* FIXME: priority */
struct bssgp_lv ms_ra_cap;
@@ -157,6 +183,17 @@
int bssgp_tx_paging(uint16_t nsei, uint16_t ns_bvci,
struct bssgp_paging_info *pinfo);
+/* input function of the flow control implementation, called first
+ * for the MM flow control, and then as the MM flow control output
+ * callback in order to perform BVC flow control */
+int bssgp_fc_in(struct bssgp_flow_control *fc, struct msgb *msg,
+ uint32_t llc_pdu_len, void *priv);
+
+/* Initialize the Flow Control parameters for a new MS according to
+ * default values for the BVC specified by BVCI and NSEI */
+int bssgp_fc_ms_init(struct bssgp_flow_control *fc_ms, uint16_t bvci,
+ uint16_t nsei);
+
/* gprs_bssgp_vty.c */
int bssgp_vty_init(void);
void bssgp_set_log_ss(int ss);