gprs: Separate LLC parsing from LLC state handling
Currently LLC parsing is part of gprs_llc.c which needs large parts
of the SGSN code parsing to fulfill its link dependencies.
This patch moves the functions that just do plain parsing, dumping,
and FCS computation to a different file to avoid these dependencies
if LLC stateful processing is not needed. It also exposes
struct gprs_llc_hdr_parsed and enum gprs_llc_cmd publically.
Sponsored-by: On-Waves ehf
diff --git a/openbsc/include/openbsc/gprs_llc.h b/openbsc/include/openbsc/gprs_llc.h
index 4be7b1f..854b968 100644
--- a/openbsc/include/openbsc/gprs_llc.h
+++ b/openbsc/include/openbsc/gprs_llc.h
@@ -165,6 +165,39 @@
extern struct llist_head gprs_llc_llmes;
+/* LLC low level types */
+
+enum gprs_llc_cmd {
+ GPRS_LLC_NULL,
+ GPRS_LLC_RR,
+ GPRS_LLC_ACK,
+ GPRS_LLC_RNR,
+ GPRS_LLC_SACK,
+ GPRS_LLC_DM,
+ GPRS_LLC_DISC,
+ GPRS_LLC_UA,
+ GPRS_LLC_SABM,
+ GPRS_LLC_FRMR,
+ GPRS_LLC_XID,
+ GPRS_LLC_UI,
+};
+
+struct gprs_llc_hdr_parsed {
+ uint8_t sapi;
+ uint8_t is_cmd:1,
+ ack_req:1,
+ is_encrypted:1;
+ uint32_t seq_rx;
+ uint32_t seq_tx;
+ uint32_t fcs;
+ uint32_t fcs_calc;
+ uint8_t *data;
+ uint16_t data_len;
+ uint16_t crc_length;
+ enum gprs_llc_cmd cmd;
+};
+
+
/* BSSGP-UL-UNITDATA.ind */
int gprs_llc_rcvmsg(struct msgb *msg, struct tlv_parsed *tv);
@@ -199,4 +232,12 @@
return 0 < delta && delta < 32;
}
+/* LLC low level functions */
+
+/* parse a GPRS LLC header, also check for invalid frames */
+int gprs_llc_hdr_parse(struct gprs_llc_hdr_parsed *ghp,
+ uint8_t *llc_hdr, int len);
+void gprs_llc_hdr_dump(struct gprs_llc_hdr_parsed *gph);
+int gprs_llc_fcs(uint8_t *data, unsigned int len);
+
#endif