From 842599ca6252b9d65504fbe55148c6aad86f7025 Mon Sep 17 00:00:00 2001 From: Alexander Couzens Date: Wed, 20 Jan 2021 13:03:03 +0100 Subject: gprs_ns2_vc_fsm: check NSEI match the NSE The NSE must match the PDUs. The only exception is a RESET with dialect ipaccess. However those will be handled later. Change-Id: Ic8fc49d850490feb0ff69171a6b0881ae8696c0b --- src/gb/gprs_ns2_vc_fsm.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/src/gb/gprs_ns2_vc_fsm.c b/src/gb/gprs_ns2_vc_fsm.c index fc2a86a8..3ec69097 100644 --- a/src/gb/gprs_ns2_vc_fsm.c +++ b/src/gb/gprs_ns2_vc_fsm.c @@ -750,6 +750,7 @@ int gprs_ns2_vc_rx(struct gprs_ns2_vc *nsvc, struct msgb *msg, struct tlv_parsed struct osmo_fsm_inst *fi = nsvc->fi; int rc = 0; uint8_t cause; + uint16_t nsei; /* TODO: 7.2: on UNBLOCK/BLOCK: check if NS-VCI is correct, * if not answer STATUS with "NS-VC unknown" */ @@ -763,6 +764,19 @@ int gprs_ns2_vc_rx(struct gprs_ns2_vc *nsvc, struct msgb *msg, struct tlv_parsed } } + if (TLVP_PRESENT(tp, NS_IE_NSEI)) { + nsei = tlvp_val16be(tp, NS_IE_NSEI); + if (nsei != nsvc->nse->nsei) { + /* 48.016 ยง 7.3.1 send, RESET_ACK to wrong NSVCI + ignore */ + if (nsh->pdu_type == NS_PDUT_RESET) + ns2_tx_reset_ack(nsvc); + + LOGNSVC(nsvc, LOGL_ERROR, "Rx %s with wrong NSEI=%05u. Ignoring PDU.\n", + get_value_string(gprs_ns_pdu_strings, nsh->pdu_type), nsei); + goto out; + } + } + switch (nsh->pdu_type) { case NS_PDUT_RESET: osmo_fsm_inst_dispatch(fi, GPRS_NS2_EV_RX_RESET, tp); -- cgit v1.2.3