WIP: send xid window size

siu/l2tp/l2tpd.h

@@ -8,6 +8,7 @@
 #include <osmocom/core/logging.h>
 #include <osmocom/core/msgb.h>
 #include <osmocom/core/select.h>
+#include <osmocom/core/timer.h>
 
 #include "l2tpd_socket.h"
 
@@ -71,8 +72,10 @@ struct l2tpd_session {
 	uint8_t remote_end_id;
 	/* finite state machine for call/session */
 	struct osmo_fsm_inst *fsm;
-
+	/* send every X ms a xid request with window size */
+	struct osmo_timer_list  xid_timer;
 	/* TODO: sockets for TRAU and PCU */
+
 };
 
 struct traffic_channel {

siu/l2tp/l2tpd_fsm.c

@@ -1,10 +1,12 @@
 
 #include <osmocom/core/fsm.h>
+#include <osmocom/core/timer.h>
 
 #include "l2tp_protocol.h"
 
 #include "l2tpd.h"
 #include "l2tpd_packet.h"
+#include "l2tpd_lapd.h"
 #include "l2tpd_data.h"
 #include "l2tpd_fsm.h"
 
@@ -320,6 +322,38 @@ static void l2tp_ic_s_established(struct osmo_fsm_inst *fi, uint32_t event, void
 	/* FIXME: remove old session if it got dealloc from l2i->trau.session etc. */
 }
 
+static void established_timer_cb(void *priv)
+{
+	struct l2tpd_session *l2s = priv;
+	switch (l2s->remote_end_id) {
+		case TC_GROUP_PGSL:
+			break;
+		case TC_GROUP_RSL_OML:
+//			lapd_send_xid(l2i, l2s, 00, 01);
+//			lapd_send_xid(l2i, l2s, 62, 62);
+//			lapd_send_xid(l2i, l2s, 62, 01);
+			break;
+		case TC_GROUP_TRAU:
+			break;
+	}
+	osmo_timer_schedule(&l2s->xid_timer, 0, 500 * 1000);
+}
+
+static void l2tp_ic_s_established_onenter(struct osmo_fsm_inst *fi, uint32_t prev_state)
+{
+	struct l2tpd_session *l2s = (struct l2tpd_session *) fi->priv;
+	osmo_timer_schedule(&l2s->xid_timer, 0, 500 * 1000);
+
+	l2s->xid_timer.cb = established_timer_cb;
+	l2s->xid_timer.data = l2s;
+	/* start XID until received */
+}
+
+static void l2tp_ic_s_established_onleave(struct osmo_fsm_inst *fi, uint32_t prev_state)
+{
+	;
+}
+
 
 static const struct value_string l2tp_ic_names[] = {
 	{ L2IC_E_RX_ICRQ, "RX-InCall-Req" },
@@ -348,6 +382,8 @@ static const struct osmo_fsm_state l2tp_ic_states[] = {
 		.out_state_mask = 0,
 		.name = "ESTABLISHED",
 		.action = l2tp_ic_s_established,
+		.onenter = l2tp_ic_s_established_onenter,
+		.onleave = l2tp_ic_s_established_onleave,
 	},
 };
 

siu/l2tp/l2tpd_lapd.c

@@ -206,6 +206,42 @@ int lapd_ehdlc_to_lapd(struct l2tpd_instance *l2i, struct l2tpd_session *l2s, st
 }
 
 
+/*!
+ * \brief fill_xid write a ehdlc xid window request into msgb
+ * \param msg
+ * \param csapi
+ * \param ctei
+ * \return 0 on success
+ */
+int lapd_send_xid(struct l2tpd_instance *l2i, struct l2tpd_session *l2s, int sapi, int tei)
+{
+	struct msgb *msg = l2tp_msgb_alloc();
+	uint16_t ehdlc_compressed = 0;
+	int rc = 0;
+	uint8_t xid[14] = {
+		0xaf, 0x82, 0x80, /* U, XID, Unnumbered, */
+		0x00, 0x09, /* length */
+		0x07, 0x01, 0x10, /* transmit window size */
+		0x09, 0x01, 0x0e, /* timer (ms) */
+		0x08, 0x01, 0x03 }; /* receive window */
+	int length = ARRAY_SIZE(xid) + 2; /* add 2 byte for the ehdlc header itself */
+	int cr = 1;
+
+	ehdlc_compressed |= (sapi_to_csapi(sapi, cr) <<  EHDLC_CSAPI_SHIFT) & EHDLC_CSAPI_MASK;
+	ehdlc_compressed |= (tei_to_ctei(tei) <<  EHDLC_CTEI_SHIFT) & EHDLC_CTEI_MASK;
+	ehdlc_compressed |= length & EHDLC_LENGTH_MASK;
+
+	msgb_put_u16(msg, ehdlc_compressed);
+	memcpy(msgb_put(msg, ARRAY_SIZE(xid)), xid, ARRAY_SIZE(xid));
+	msg->dst = l2s;
+
+	rc = l2tp_tx_data(msg);
+	msgb_free(msg);
+	return rc;
+}
+
+
+
 /*!
  * \brief rsl_oml_cb called when data arrived on the unix socket
  * \param fd

siu/l2tp/l2tpd_lapd.h

@@ -2,6 +2,7 @@
 
 int lapd_lapd_to_ehdlc(struct l2tpd_instance *l2i, struct msgb *msg);
 int lapd_ehdlc_to_lapd(struct l2tpd_instance *l2i, struct l2tpd_session *session, struct msgb *msg);
+int lapd_send_xid(struct l2tpd_instance *l2i, struct l2tpd_session *l2s, int sapi, int tei);
 int unix_rsl_oml_cb(struct osmo_fd *fd);
 int unix_trau_cb(struct osmo_fd *fd);
 int unix_pgsl_cb(struct osmo_fd *fd);