mirror of https://gerrit.osmocom.org/libosmocore
968 lines
23 KiB
C
968 lines
23 KiB
C
/*! \file frame_relay.c
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* Implement frame relay/PVC by Q.933
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*/
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/* (C) 2020 Harald Welte <laforge@gnumonks.org>
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* (C) 2020 sysmocom - s.f.m.c. GmbH
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* Author: Alexander Couzens <lynxis@fe80.eu>
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*
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* All Rights Reserved
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*
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* SPDX-License-Identifier: GPL-2.0+
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*
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*/
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#include <stdint.h>
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#include <stdbool.h>
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#include <unistd.h>
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#include <errno.h>
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#include <osmocom/gprs/frame_relay.h>
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#include <osmocom/core/endian.h>
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#include <osmocom/core/utils.h>
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#include <osmocom/core/logging.h>
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#include <osmocom/core/linuxlist.h>
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#include <osmocom/core/tdef.h>
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#include <osmocom/core/timer.h>
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#include <osmocom/core/msgb.h>
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#include <osmocom/gsm/tlv.h>
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#define LOGPFRL(frl, lvl, fmt, args ...) \
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LOGP(DFR, lvl, "%s: " fmt, (frl)->name, ## args)
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#define DFR DLNS
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/* Table 4-2/Q.931 */
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enum q931_msgtype {
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/* Call establishment message */
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Q931_MSGT_ALERTING = 0x01,
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Q931_MSGT_CALL_PROCEEDING = 0x02,
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Q931_MSGT_CONNECT = 0x07,
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Q931_MSGT_CONNECT_ACK = 0x0f,
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Q931_MSGT_PROGRESS = 0x03,
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Q931_MSGT_SETUP = 0x05,
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Q931_MSGT_SETUP_ACK = 0x0d,
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/* Call information phase message */
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Q931_MSGT_RESUME = 0x26,
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Q931_MSGT_RESUME_ACK = 0x2e,
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Q931_MSGT_RESUME_REJ = 0x22,
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Q931_MSGT_SUSPEND = 0x25,
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Q931_MSGT_SUSPEND_ACK = 0x2d,
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Q931_MSGT_USER_INFO = 0x20,
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/* Call clearing message */
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Q931_MSGT_DISCONNECT = 0x45,
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Q931_MSGT_RELEASE = 0x4d,
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Q931_MSGT_RELEASE_COMPLETE = 0x5a,
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Q931_MSGT_RESTART = 0x46,
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Q931_MSGT_RESTART_ACK = 0x4e,
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/* Miscellaneous messages */
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Q931_MSGT_SEGMENT = 0x60,
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Q931_MSGT_CONGESTION_CONTROL = 0x79,
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Q931_MSGT_IFORMATION = 0x7b,
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Q931_MSGT_NOTIFY = 0x6e,
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Q931_MSGT_STATUS = 0x7d,
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Q931_MSGT_STATUS_ENQUIRY = 0x75,
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};
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/* Figure A.1/Q.933 Report type information element */
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enum q933_type_of_report {
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Q933_REPT_FULL_STATUS = 0x00,
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Q933_REPT_LINK_INTEGRITY_VERIF = 0x01,
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Q933_REPT_SINGLE_PVC_ASYNC_STS = 0x02,
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};
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/* Q.933 Section A.3 */
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enum q933_iei {
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Q933_IEI_REPORT_TYPE = 0x51,
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Q933_IEI_LINK_INT_VERIF = 0x53,
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Q933_IEI_PVC_STATUS = 0x57,
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};
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/* Q.933 Section A.3.3 */
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enum q933_pvc_status {
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Q933_PVC_STATUS_DLC_ACTIVE = 0x02,
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Q933_PVC_STATUS_DLC_DELETE = 0x04,
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Q933_PVC_STATUS_DLC_NEW = 0x08,
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};
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#define LAPF_UI 0x03 /* UI control word */
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#define Q931_PDISC_CC 0x08 /* protocol discriminator */
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#define LMI_Q933A_CALLREF 0x00 /* NULL call-ref */
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/* LMI DLCI values */
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#define LMI_Q933A_DLCI 0 /* Q.933A DLCI */
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#define LMI_CISCO_DLCI 1023 /* Cisco DLCI */
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/* maximum of supported */
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#define MAX_SUPPORTED_PVC 10
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/* TODO: add counters since good connection */
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/* Message header of the L3 payload of a Q.933 Annex A message */
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struct q933_a_hdr {
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uint8_t prot_disc;
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uint8_t call_ref;
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uint8_t msg_type;
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} __attribute__((packed));
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/* Value part of the Q.933 Annex A.3.3 IE */
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struct q933_a_pvc_sts {
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uint8_t dlci_msb:6,
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spare:1,
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ext0:1;
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uint8_t space1:3,
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dlci_lsb:4,
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ext1:1;
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uint8_t reserved:1,
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active:1,
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delete:1,
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new:1,
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spare2:3,
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ext2:1;
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} __attribute__((packed));
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/* RX Message: 14 [ 00 01 03 08 00 75 95 01 01 00 03 02 01 00 ] */
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/* RX Message: 13 [ 00 01 03 08 00 75 51 01 00 53 02 01 00 ] */
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const struct value_string osmo_fr_role_names[] = {
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{ FR_ROLE_USER_EQUIPMENT, "USER" },
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{ FR_ROLE_NETWORK_EQUIPMENT, "NETWORK" },
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{ 0, NULL }
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};
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/* Table A.4/Q.933 */
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struct osmo_tdef fr_tdefs[] = {
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{
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.T=391,
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.default_val = 10,
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.min_val = 5,
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.max_val = 30,
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.desc = "Link integrity verification polling timer",
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.unit = OSMO_TDEF_S,
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}, {
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.T=392,
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.default_val = 15,
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.min_val = 5,
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.max_val = 30,
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.desc = "Polling verification timer",
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.unit = OSMO_TDEF_S,
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},
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{}
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};
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static const struct tlv_definition q933_att_tlvdef = {
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.def = {
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[Q933_IEI_REPORT_TYPE] = { TLV_TYPE_TLV },
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[Q933_IEI_LINK_INT_VERIF] = { TLV_TYPE_TLV },
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[Q933_IEI_PVC_STATUS] = { TLV_TYPE_TLV },
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},
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};
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static void check_link_state(struct osmo_fr_link *link, bool valid);
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static inline uint16_t q922_to_dlci(const uint8_t *hdr)
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{
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return ((hdr[0] & 0xFC) << 2) | ((hdr[1] & 0xF0) >> 4);
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}
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static inline void dlci_to_q922(uint8_t *hdr, uint16_t dlci)
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{
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hdr[0] = (dlci >> 2) & 0xFC;
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hdr[1] = ((dlci << 4) & 0xF0) | 0x01;
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}
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/* allocate a message buffer and put Q.933 Annex A headers (L2 + L3) */
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static struct msgb *q933_msgb_alloc(uint16_t dlci, uint8_t prot_disc, uint8_t msg_type)
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{
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struct msgb *msg = msgb_alloc_headroom(1600+64, 64, "FR Q.933 Tx");
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struct q933_a_hdr *qh;
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if (!msg)
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return NULL;
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msg->l1h = msgb_put(msg, 2);
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dlci_to_q922(msg->l1h, dlci);
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/* LAPF UI control */
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msg->l2h = msgb_put(msg, 1);
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*msg->l2h = LAPF_UI;
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msg->l3h = msgb_put(msg, sizeof(*qh));
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qh = (struct q933_a_hdr *) msg->l3h;
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qh->prot_disc = prot_disc;
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qh->call_ref = LMI_Q933A_CALLREF;
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qh->msg_type = msg_type;
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return msg;
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}
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/* obtain the [next] transmit sequence number */
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static uint8_t link_get_tx_seq(struct osmo_fr_link *link)
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{
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/* The {user equipment, network} increments the send sequence
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* counter using modulo 256. The value zero is skipped. */
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link->last_tx_seq++;
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if (link->last_tx_seq == 0)
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link->last_tx_seq++;
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return link->last_tx_seq;
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}
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/* Append PVC Status IE according to Q.933 A.3.2 */
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static void msgb_put_link_int_verif(struct msgb *msg, struct osmo_fr_link *link)
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{
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uint8_t link_int_tx[2];
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link_int_tx[0] = link_get_tx_seq(link);
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link_int_tx[1] = link->last_rx_seq;
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msgb_tlv_put(msg, Q933_IEI_LINK_INT_VERIF, 2, link_int_tx);
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}
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static void dlc_destroy(struct osmo_fr_dlc *dlc)
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{
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llist_del(&dlc->list);
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talloc_free(dlc);
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}
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/* Append PVC Status IE according to Q.933 A.3.3 */
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static void msgb_put_pvc_status(struct msgb *msg, struct osmo_fr_dlc *dlc)
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{
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uint8_t ie[3];
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ie[0] = (dlc->dlci >> 4) & 0x3f;
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/* extension bits */
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ie[1] = 0x80 | ((dlc->dlci & 0xf) << 3);
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/* extension bits */
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ie[2] = 0x80;
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/* FIXME: validate: this status should be added as long it's not yet acked by the remote */
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if (dlc->active)
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ie[2] |= Q933_PVC_STATUS_DLC_ACTIVE;
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if (dlc->add) {
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ie[2] |= Q933_PVC_STATUS_DLC_NEW;
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/* we've reported it as new once, reset the status */
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}
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if (dlc->del) {
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ie[2] |= Q933_PVC_STATUS_DLC_DELETE;
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/* we've reported it as deleted once, destroy it */
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dlc_destroy(dlc);
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}
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msgb_tlv_put(msg, Q933_IEI_PVC_STATUS, 3, ie);
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}
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/* Send a Q.933 STATUS ENQUIRY given type over given link */
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static int tx_lmi_q933_status_enq(struct osmo_fr_link *link, uint8_t rep_type)
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{
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struct msgb *resp;
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resp = q933_msgb_alloc(0, Q931_PDISC_CC, Q931_MSGT_STATUS_ENQUIRY);
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if (!resp)
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return -1;
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resp->dst = link;
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link->expected_rep = rep_type;
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/* Table A.2/Q.933 */
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msgb_tlv_put(resp, Q933_IEI_REPORT_TYPE, 1, &rep_type);
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msgb_put_link_int_verif(resp, link);
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return link->tx_cb(link->tx_cb_data, resp);
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}
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/* Send a Q.933 STATUS of given type over given link */
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static int tx_lmi_q933_status(struct osmo_fr_link *link, uint8_t rep_type)
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{
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struct osmo_fr_dlc *dlc;
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struct msgb *resp;
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resp = q933_msgb_alloc(0, Q931_PDISC_CC, Q931_MSGT_STATUS);
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if (!resp)
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return -1;
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resp->dst = link;
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/* Table A.1/Q.933 */
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msgb_tlv_put(resp, Q933_IEI_REPORT_TYPE, 1, &rep_type);
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switch (rep_type) {
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case Q933_REPT_FULL_STATUS:
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msgb_put_link_int_verif(resp, link);
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llist_for_each_entry(dlc, &link->dlc_list, list) {
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if (dlc->add || dlc->del)
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dlc->state_send = true;
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msgb_put_pvc_status(resp, dlc);
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}
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break;
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case Q933_REPT_LINK_INTEGRITY_VERIF:
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msgb_put_link_int_verif(resp, link);
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llist_for_each_entry(dlc, &link->dlc_list, list) {
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if (dlc->add || dlc->del) {
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msgb_put_pvc_status(resp, dlc);
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dlc->state_send = true;
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}
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}
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break;
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case Q933_REPT_SINGLE_PVC_ASYNC_STS:
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llist_for_each_entry(dlc, &link->dlc_list, list)
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msgb_put_pvc_status(resp, dlc);
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break;
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}
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return link->tx_cb(link->tx_cb_data, resp);
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}
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/* Q.933 */
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static int rx_lmi_q933_status_enq(struct msgb *msg, struct tlv_parsed *tp)
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{
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struct osmo_fr_link *link = msg->dst;
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struct osmo_fr_dlc *dlc;
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const uint8_t *link_int_rx;
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uint8_t rep_type;
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OSMO_ASSERT(link);
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if (link->role == FR_ROLE_USER_EQUIPMENT) {
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LOGPFRL(link, LOGL_ERROR, "STATUS-ENQ aren't supported in role user\n");
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return -1;
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}
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/* check for mandatory IEs */
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if (!TLVP_PRES_LEN(tp, Q933_IEI_REPORT_TYPE, 1) ||
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!TLVP_PRES_LEN(tp, Q933_IEI_LINK_INT_VERIF, 2))
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return -1;
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rep_type = *TLVP_VAL(tp, Q933_IEI_REPORT_TYPE);
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link_int_rx = TLVP_VAL(tp, Q933_IEI_LINK_INT_VERIF);
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link->last_rx_seq = link_int_rx[0];
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/* the network checks the receive sequence number received from
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* the user equipment against its send sequence counter */
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if (link_int_rx[1] != link->last_tx_seq) {
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check_link_state(link, false);
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link->err_count++;
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} else {
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check_link_state(link, true);
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/* confirm DLC state changes */
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llist_for_each_entry(dlc, &link->dlc_list, list) {
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if (!dlc->state_send)
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continue;
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if (dlc->add) {
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dlc->active = link->state;
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dlc->add = false;
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}
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if (dlc->del) {
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dlc->del = false;
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}
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dlc->state_send = false;
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}
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}
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/* The network responds to each STATUS ENQUIRY message with a
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* STATUS message and resets the T392 timer */
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osmo_timer_schedule(&link->t392, osmo_tdef_get(link->net->T_defs, 392, OSMO_TDEF_S, 15), 0);
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return tx_lmi_q933_status(link, rep_type);
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}
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/* check if the link become active.
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* The link becomes active when enough times a STATUS/STATUS ENQUIRY arrives without any loss.
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* Look at the last N393 STATUS/STATUS ENQUIRY PDUs. The link is valid if at least N392
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* got received.
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* param[in] valid contains the status of the last packet */
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static void check_link_state(struct osmo_fr_link *link, bool valid)
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{
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unsigned int last, i;
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unsigned int carry = 0;
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struct osmo_fr_dlc *dlc;
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link->succeed <<= 1;
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if (valid)
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link->succeed |= 1;
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/* count the bits */
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last = link->succeed & ((1 << link->net->n393) - 1);
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for (i = 0; i < link->net->n393; i++)
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if (last & (1 << i))
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carry++;
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if (link->net->n393 - carry >= link->net->n392) {
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/* failing link */
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if (!link->state)
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return;
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LOGPFRL(link, LOGL_NOTICE, "Link failed\n");
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link->state = false;
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if (link->role == FR_ROLE_USER_EQUIPMENT)
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return;
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llist_for_each_entry(dlc, &link->dlc_list, list) {
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dlc->active = false;
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}
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} else {
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/* good link */
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if (link->state)
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return;
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LOGPFRL(link, LOGL_NOTICE, "Link recovered\n");
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link->state = true;
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if (link->role == FR_ROLE_USER_EQUIPMENT)
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return;
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llist_for_each_entry(dlc, &link->dlc_list, list) {
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if (!dlc->add && !dlc->del)
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dlc->active = true;
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}
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}
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}
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static int validate_pvc_status(struct tlv_parsed *tp, size_t tp_len)
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{
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size_t i;
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uint16_t len = 0;
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for (i = 0; i < tp_len; i++) {
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if (!TLVP_PRESENT(&tp[i], Q933_IEI_PVC_STATUS))
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continue;
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/* PVC status can be 2 or 3 bytes. If the PVC is bigger
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* ignore this to be compatible to future extensions. */
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len = TLVP_LEN(&tp[i], Q933_IEI_PVC_STATUS);
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if (len <= 1) {
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return -EINVAL;
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}
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/* FIXME: validate correct flags: are some flags invalid at the same time? */
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}
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return 0;
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}
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static int parse_full_pvc_status(struct osmo_fr_link *link, struct tlv_parsed *tp, size_t tp_len)
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{
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size_t i;
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int err = 0;
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struct osmo_fr_dlc *dlc, *tmp;
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struct q933_a_pvc_sts *pvc;
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uint16_t dlci = 0;
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uint16_t *dlcis = talloc_zero_array(link, uint16_t, tp_len);
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if (!dlcis)
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return -ENOMEM;
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/* first run validate all PVCs */
|
|
err = validate_pvc_status(tp, tp_len);
|
|
if (err < 0)
|
|
goto out;
|
|
|
|
for (i = 0; i < tp_len; i++) {
|
|
if (!TLVP_PRESENT(&tp[i], Q933_IEI_PVC_STATUS))
|
|
continue;
|
|
|
|
/* parse only 3 byte PVCs */
|
|
pvc = (struct q933_a_pvc_sts *) TLVP_VAL_MINLEN(
|
|
&tp[i],
|
|
Q933_IEI_PVC_STATUS,
|
|
sizeof(struct q933_a_pvc_sts));
|
|
if (!pvc)
|
|
continue;
|
|
|
|
dlci = ((pvc->dlci_msb & 0x3f) << 4) | (pvc->dlci_lsb & 0xf);
|
|
dlcis[i] = dlci;
|
|
dlc = osmo_fr_dlc_by_dlci(link, dlci);
|
|
if (!dlc) {
|
|
dlc = osmo_fr_dlc_alloc(link, dlci);
|
|
if (!dlc) {
|
|
LOGPFRL(link, LOGL_ERROR, "Could not create DLC %d\n", dlci);
|
|
continue;
|
|
}
|
|
}
|
|
|
|
/* Figure A.3/Q.933: The delete bit is only applicable for timely notification
|
|
* using the optional single PVC asynchronous status report.
|
|
* Ignoring the delete. */
|
|
dlc->add = pvc->new;
|
|
dlc->active = pvc->active;
|
|
dlc->del = 0;
|
|
}
|
|
|
|
/* check if all dlc are present in PVC Status */
|
|
llist_for_each_entry_safe(dlc, tmp, &link->dlc_list, list) {
|
|
bool found = false;
|
|
for (i = 0; i < tp_len; i++) {
|
|
if (dlcis[i] == dlc->dlci) {
|
|
found = true;
|
|
break;
|
|
}
|
|
}
|
|
|
|
if (!found) {
|
|
dlc->active = false;
|
|
dlc->del = true;
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
out:
|
|
talloc_free(dlcis);
|
|
return err;
|
|
}
|
|
|
|
static int parse_link_pvc_status(struct osmo_fr_link *link, struct tlv_parsed *tp, size_t tp_len)
|
|
{
|
|
int err;
|
|
size_t i;
|
|
struct q933_a_pvc_sts *pvc;
|
|
struct osmo_fr_dlc *dlc;
|
|
uint16_t dlci = 0;
|
|
|
|
err = validate_pvc_status(tp, tp_len);
|
|
if (err < 0)
|
|
return err;
|
|
|
|
for (i = 0; i < tp_len; i++) {
|
|
if (!TLVP_PRESENT(&tp[i], Q933_IEI_PVC_STATUS))
|
|
continue;
|
|
|
|
/* parse only 3 byte PVCs */
|
|
pvc = (struct q933_a_pvc_sts *) TLVP_VAL_MINLEN(
|
|
&tp[i],
|
|
Q933_IEI_PVC_STATUS,
|
|
sizeof(struct q933_a_pvc_sts));
|
|
if (!pvc)
|
|
continue;
|
|
|
|
dlci = ((pvc->dlci_msb & 0x3f) << 4) | (pvc->dlci_lsb & 0xf);
|
|
dlc = osmo_fr_dlc_by_dlci(link, dlci);
|
|
if (!dlc) {
|
|
/* don't create dlc's for the ones which are about to be deleted. */
|
|
if (pvc->delete)
|
|
continue;
|
|
|
|
dlc = osmo_fr_dlc_alloc(link, dlci);
|
|
if (!dlc) {
|
|
LOGPFRL(link, LOGL_ERROR, "Rx STATUS: Could not create DLC %d\n", dlci);
|
|
}
|
|
}
|
|
|
|
if (pvc->delete) {
|
|
dlc->del = 1;
|
|
} else {
|
|
dlc->add = pvc->new;
|
|
dlc->active = pvc->active;
|
|
dlc->del = 0;
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static size_t count_pvc_status(struct tlv_parsed *tp, size_t tp_len)
|
|
{
|
|
size_t i, count = 0;
|
|
for (i = 0; i < tp_len; i++) {
|
|
if (!TLVP_PRESENT(&tp[i], Q933_IEI_PVC_STATUS))
|
|
continue;
|
|
count++;
|
|
}
|
|
|
|
return count;
|
|
}
|
|
|
|
static int rx_lmi_q933_status(struct msgb *msg, struct tlv_parsed *tp)
|
|
{
|
|
struct osmo_fr_link *link = msg->dst;
|
|
const uint8_t *link_int_rx;
|
|
uint8_t rep_type;
|
|
|
|
OSMO_ASSERT(link);
|
|
|
|
if (link->role == FR_ROLE_NETWORK_EQUIPMENT) {
|
|
LOGPFRL(link, LOGL_ERROR, "Rx STATUS: STATUS aren't supported in role network\n");
|
|
return -1;
|
|
}
|
|
|
|
/* check for mandatory IEs */
|
|
if (!TLVP_PRES_LEN(tp, Q933_IEI_REPORT_TYPE, 1)) {
|
|
LOGPFRL(link, LOGL_NOTICE, "Rx STATUSL: Missing TLV Q933 Report Type\n");
|
|
return -1;
|
|
}
|
|
|
|
rep_type = *TLVP_VAL(tp, Q933_IEI_REPORT_TYPE);
|
|
|
|
switch (rep_type) {
|
|
case Q933_REPT_FULL_STATUS:
|
|
case Q933_REPT_LINK_INTEGRITY_VERIF:
|
|
if (rep_type != link->expected_rep) {
|
|
LOGPFRL(link, LOGL_NOTICE, "Rx STATUS: Unexpected Q933 report type (got 0x%x != exp 0x%x)\n",
|
|
rep_type, link->expected_rep);
|
|
return -1;
|
|
}
|
|
|
|
if (!TLVP_PRES_LEN(tp, Q933_IEI_LINK_INT_VERIF, 2)) {
|
|
LOGPFRL(link, LOGL_NOTICE, "Rx STATUS: Missing TLV Q933 Link Integrety Verification\n");
|
|
return -1;
|
|
}
|
|
link_int_rx = TLVP_VAL(tp, Q933_IEI_LINK_INT_VERIF);
|
|
link->last_rx_seq = link_int_rx[0];
|
|
/* The received receive sequence number is not valid if
|
|
* it is not equal to the last transmitted send sequence
|
|
* number. Ignore messages containing this error. As a
|
|
* result, timer T391 expires and the user then
|
|
* increments the error count. */
|
|
if (link_int_rx[1] != link->last_tx_seq)
|
|
return 0;
|
|
break;
|
|
case Q933_REPT_SINGLE_PVC_ASYNC_STS:
|
|
default:
|
|
return -1;
|
|
}
|
|
|
|
check_link_state(link, true);
|
|
if (count_pvc_status(tp, MAX_SUPPORTED_PVC + 1) > MAX_SUPPORTED_PVC) {
|
|
LOGPFRL(link, LOGL_ERROR, "Rx STATUS: Too many PVC! Only %d are supported!\n", MAX_SUPPORTED_PVC);
|
|
}
|
|
|
|
switch (rep_type) {
|
|
case Q933_REPT_FULL_STATUS:
|
|
parse_full_pvc_status(link, tp, MAX_SUPPORTED_PVC);
|
|
break;
|
|
case Q933_REPT_LINK_INTEGRITY_VERIF:
|
|
parse_link_pvc_status(link, tp, MAX_SUPPORTED_PVC);
|
|
break;
|
|
default:
|
|
break;
|
|
}
|
|
|
|
/* The network responds to each STATUS ENQUIRY message with a
|
|
* STATUS message and resets the T392 timer */
|
|
osmo_timer_schedule(&link->t392, osmo_tdef_get(link->net->T_defs, 392, OSMO_TDEF_S, 15), 0);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int rx_lmi_q922(struct msgb *msg)
|
|
{
|
|
struct osmo_fr_link *link = msg->dst;
|
|
struct q933_a_hdr *qh;
|
|
/* the + 1 is used to detect more than MAX_SUPPORTED_PVC */
|
|
struct tlv_parsed tp[MAX_SUPPORTED_PVC + 1];
|
|
uint8_t *lapf;
|
|
int rc;
|
|
|
|
OSMO_ASSERT(link);
|
|
|
|
if (msgb_l2len(msg) < 1)
|
|
return -1;
|
|
lapf = msgb_l2(msg);
|
|
|
|
/* we only support LAPF UI frames */
|
|
if (lapf[0] != LAPF_UI)
|
|
return -1;
|
|
|
|
msg->l3h = msg->l2h + 1;
|
|
if (msgb_l3len(msg) < 3)
|
|
return -1;
|
|
|
|
qh = (struct q933_a_hdr *) msgb_l3(msg);
|
|
if (qh->prot_disc != Q931_PDISC_CC) {
|
|
LOGPFRL(link, LOGL_NOTICE,
|
|
"Rx unsupported LMI protocol discriminator %u\n", qh->prot_disc);
|
|
return -1;
|
|
}
|
|
|
|
rc = tlv_parse2(tp, MAX_SUPPORTED_PVC + 1, &q933_att_tlvdef,
|
|
msgb_l3(msg) + sizeof(*qh),
|
|
msgb_l3len(msg) - sizeof(*qh), 0, 0);
|
|
if (rc < 0) {
|
|
LOGPFRL(link, LOGL_NOTICE,
|
|
"Failed to parse TLVs in LMI message type %u\n", qh->msg_type);
|
|
return rc;
|
|
}
|
|
|
|
switch (qh->msg_type) {
|
|
case Q931_MSGT_STATUS_ENQUIRY:
|
|
rc = rx_lmi_q933_status_enq(msg, tp);
|
|
break;
|
|
case Q931_MSGT_STATUS:
|
|
rc = rx_lmi_q933_status(msg, tp);
|
|
break;
|
|
default:
|
|
LOGPFRL(link, LOGL_NOTICE,
|
|
"Rx unsupported LMI message type %u\n", qh->msg_type);
|
|
rc = -1;
|
|
break;
|
|
}
|
|
msgb_free(msg);
|
|
|
|
return rc;
|
|
}
|
|
|
|
int osmo_fr_rx(struct msgb *msg)
|
|
{
|
|
int rc = 0;
|
|
uint8_t *frh;
|
|
uint16_t dlci;
|
|
struct osmo_fr_dlc *dlc;
|
|
struct osmo_fr_link *link = msg->dst;
|
|
|
|
OSMO_ASSERT(link);
|
|
|
|
if (msgb_length(msg) < 2) {
|
|
LOGPFRL(link, LOGL_ERROR, "Rx short FR header: %u bytes\n", msgb_length(msg));
|
|
rc = -1;
|
|
goto out;
|
|
}
|
|
|
|
frh = msg->l1h = msgb_data(msg);
|
|
if (frh[0] & 0x01) {
|
|
LOGPFRL(link, LOGL_NOTICE, "Rx Unsupported single-byte FR address\n");
|
|
rc = -1;
|
|
goto out;
|
|
}
|
|
if ((frh[1] & 0x0f) != 0x01) {
|
|
LOGPFRL(link, LOGL_NOTICE, "Rx Unknown second FR octet 0x%02x\n", frh[1]);
|
|
rc = -1;
|
|
goto out;
|
|
}
|
|
dlci = q922_to_dlci(frh);
|
|
msg->l2h = frh + 2;
|
|
|
|
switch (dlci) {
|
|
case LMI_Q933A_DLCI:
|
|
return rx_lmi_q922(msg);
|
|
case LMI_CISCO_DLCI:
|
|
LOGPFRL(link, LOGL_ERROR, "Rx Unsupported FR DLCI %u\n", dlci);
|
|
goto out;
|
|
}
|
|
|
|
if (!link->state) {
|
|
LOGPFRL(link, LOGL_NOTICE, "Link is not reliable. Discarding Rx PDU on DLCI %d\n", dlci);
|
|
goto out;
|
|
}
|
|
|
|
llist_for_each_entry(dlc, &link->dlc_list, list) {
|
|
if (dlc->dlci == dlci) {
|
|
/* dispatch to handler of respective DLC */
|
|
msg->dst = dlc;
|
|
return dlc->rx_cb(dlc->rx_cb_data, msg);
|
|
}
|
|
}
|
|
|
|
if (link->unknown_dlc_rx_cb)
|
|
return link->unknown_dlc_rx_cb(link->unknown_dlc_rx_cb_data, msg);
|
|
else
|
|
LOGPFRL(link, LOGL_NOTICE, "DLCI %u doesn't exist, discarding\n", dlci);
|
|
|
|
out:
|
|
msgb_free(msg);
|
|
|
|
return rc;
|
|
}
|
|
|
|
int osmo_fr_tx_dlc(struct msgb *msg)
|
|
{
|
|
uint8_t *frh;
|
|
struct osmo_fr_dlc *dlc = msg->dst;
|
|
struct osmo_fr_link *link = dlc->link;
|
|
|
|
OSMO_ASSERT(dlc);
|
|
OSMO_ASSERT(link);
|
|
|
|
if (!link->state) {
|
|
LOGPFRL(link, LOGL_NOTICE, "Link is not reliable (yet), discarding Tx\n");
|
|
msgb_free(msg);
|
|
return -1;
|
|
}
|
|
if (!dlc->active) {
|
|
LOGPFRL(link, LOGL_NOTICE, "DLCI %u is not active (yet), discarding Tx\n", dlc->dlci);
|
|
msgb_free(msg);
|
|
return -1;
|
|
}
|
|
LOGPFRL(link, LOGL_DEBUG, "DLCI %u is active, sending message\n", dlc->dlci);
|
|
|
|
if (msgb_headroom(msg) < 2) {
|
|
msgb_free(msg);
|
|
return -ENOSPC;
|
|
}
|
|
|
|
frh = msgb_push(msg, 2);
|
|
dlci_to_q922(frh, dlc->dlci);
|
|
|
|
msg->dst = link;
|
|
return link->tx_cb(link->tx_cb_data, msg);
|
|
}
|
|
|
|
/* Every T391 seconds, the user equipment sends a STATUS ENQUIRY
|
|
* message to the network and resets its polling timer (T391). */
|
|
static void fr_t391_cb(void *data)
|
|
{
|
|
struct osmo_fr_link *link = data;
|
|
|
|
OSMO_ASSERT(link);
|
|
|
|
if (link->polling_count % link->net->n391 == 0)
|
|
tx_lmi_q933_status_enq(link, Q933_REPT_FULL_STATUS);
|
|
else
|
|
tx_lmi_q933_status_enq(link, Q933_REPT_LINK_INTEGRITY_VERIF);
|
|
link->polling_count++;
|
|
osmo_timer_schedule(&link->t391, osmo_tdef_get(link->net->T_defs, 391, OSMO_TDEF_S, 10), 0);
|
|
}
|
|
|
|
static void fr_t392_cb(void *data)
|
|
{
|
|
struct osmo_fr_link *link = data;
|
|
|
|
OSMO_ASSERT(link);
|
|
|
|
/* A.5 The network increments the error count .. Non-receipt of
|
|
* a STATUS ENQUIRY within T392, which results in restarting
|
|
* T392 */
|
|
link->err_count++;
|
|
check_link_state(link, false);
|
|
osmo_timer_schedule(&link->t392, osmo_tdef_get(link->net->T_defs, 392, OSMO_TDEF_S, 15), 0);
|
|
}
|
|
|
|
/* allocate a frame relay network */
|
|
struct osmo_fr_network *osmo_fr_network_alloc(void *ctx)
|
|
{
|
|
struct osmo_fr_network *net = talloc_zero(ctx, struct osmo_fr_network);
|
|
if (!net)
|
|
return NULL;
|
|
|
|
INIT_LLIST_HEAD(&net->links);
|
|
net->T_defs = fr_tdefs;
|
|
osmo_tdefs_reset(net->T_defs);
|
|
net->n391 = 6;
|
|
net->n392 = 3;
|
|
net->n393 = 4;
|
|
|
|
return net;
|
|
}
|
|
|
|
void osmo_fr_network_free(struct osmo_fr_network *net)
|
|
{
|
|
struct osmo_fr_link *link, *tmp;
|
|
|
|
if (!net)
|
|
return;
|
|
|
|
llist_for_each_entry_safe(link, tmp, &net->links, list) {
|
|
osmo_fr_link_free(link);
|
|
}
|
|
}
|
|
|
|
/* allocate a frame relay link in a given network */
|
|
struct osmo_fr_link *osmo_fr_link_alloc(struct osmo_fr_network *net, enum osmo_fr_role role, const char *name)
|
|
{
|
|
struct osmo_fr_link *link = talloc_zero(net, struct osmo_fr_link);
|
|
if (!link)
|
|
return NULL;
|
|
link->role = role;
|
|
link->net = net;
|
|
link->name = talloc_strdup(link, name);
|
|
INIT_LLIST_HEAD(&link->dlc_list);
|
|
llist_add_tail(&link->list, &net->links);
|
|
|
|
osmo_timer_setup(&link->t391, fr_t391_cb, link);
|
|
osmo_timer_setup(&link->t392, fr_t392_cb, link);
|
|
|
|
switch (role) {
|
|
case FR_ROLE_USER_EQUIPMENT:
|
|
osmo_timer_schedule(&link->t391, osmo_tdef_get(link->net->T_defs, 391, OSMO_TDEF_S, 15), 0);
|
|
break;
|
|
case FR_ROLE_NETWORK_EQUIPMENT:
|
|
osmo_timer_schedule(&link->t392, osmo_tdef_get(link->net->T_defs, 392, OSMO_TDEF_S, 15), 0);
|
|
break;
|
|
}
|
|
|
|
LOGPFRL(link, LOGL_INFO, "Creating frame relay link with role %s\n", osmo_fr_role_str(role));
|
|
|
|
return link;
|
|
}
|
|
|
|
void osmo_fr_link_free(struct osmo_fr_link *link)
|
|
{
|
|
struct osmo_fr_dlc *dlc, *tmp;
|
|
|
|
if (!link)
|
|
return;
|
|
|
|
osmo_timer_del(&link->t391);
|
|
osmo_timer_del(&link->t392);
|
|
|
|
llist_for_each_entry_safe(dlc, tmp, &link->dlc_list, list) {
|
|
osmo_fr_dlc_free(dlc);
|
|
}
|
|
|
|
llist_del(&link->list);
|
|
talloc_free(link);
|
|
}
|
|
|
|
/* allocate a data link connectoin on a given framerelay link */
|
|
struct osmo_fr_dlc *osmo_fr_dlc_alloc(struct osmo_fr_link *link, uint16_t dlci)
|
|
{
|
|
struct osmo_fr_dlc *dlc = talloc_zero(link, struct osmo_fr_dlc);
|
|
if (!dlc)
|
|
return NULL;
|
|
|
|
dlc->link = link;
|
|
dlc->dlci = dlci;
|
|
dlc->active = false;
|
|
|
|
llist_add_tail(&dlc->list, &link->dlc_list);
|
|
|
|
dlc->add = true;
|
|
tx_lmi_q933_status(link, Q933_IEI_PVC_STATUS);
|
|
|
|
return dlc;
|
|
}
|
|
|
|
void osmo_fr_dlc_free(struct osmo_fr_dlc *dlc)
|
|
{
|
|
llist_del(&dlc->list);
|
|
talloc_free(dlc);
|
|
}
|
|
|
|
/* TODO: rework osmo_fr_dlc_alloc/free with handling it's own memory.
|
|
* For network role: The dlc have to created by the application (e.g. vty).
|
|
* The dlc shouldn't free'd directly. It should be communicated to the
|
|
* other side and wait until it's confirmed OR the link go off and free it afterwards.
|
|
* For user equpment role: The dlc can be created by the application or the dlc will be created
|
|
* by the frame relay because the network is configuring the dlc.
|
|
* The dlc shouldn't be free'd. Only the handler should be set to NULL.
|
|
*/
|
|
|
|
struct osmo_fr_dlc *osmo_fr_dlc_by_dlci(struct osmo_fr_link *link, uint16_t dlci)
|
|
{
|
|
struct osmo_fr_dlc *dlc;
|
|
|
|
llist_for_each_entry(dlc, &link->dlc_list, list) {
|
|
if (dlc->dlci == dlci)
|
|
return dlc;
|
|
}
|
|
return NULL;
|
|
}
|