736 lines
19 KiB
C
736 lines
19 KiB
C
/* LAPV5-DL as per Section 10.1 of ITU-T G.964 */
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/* (C) 2021 by Harald Welte <laforge@gnumonks.org>
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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 along
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* with this program; if not, write to the Free Software Foundation, Inc.,
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* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
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*
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*/
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#include "internal.h"
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#include <stdio.h>
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#include <string.h>
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#include <errno.h>
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#include <osmocom/core/linuxlist.h>
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#include <osmocom/core/logging.h>
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#include <osmocom/core/talloc.h>
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#include <osmocom/core/msgb.h>
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#include <osmocom/core/timer.h>
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#include <osmocom/abis/lapd.h>
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#include <osmocom/abis/lapd_pcap.h>
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#define LAPD_ADDR2(sapi, cr) ((((sapi) & 0x3f) << 2) | (((cr) & 0x1) << 1))
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#define LAPD_ADDR3(tei) ((((tei) & 0x7f) << 1) | 0x1)
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#define LAPD_ADDR_SAPI(addr) ((addr) >> 2)
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#define LAPD_ADDR_CR(addr) (((addr) >> 1) & 0x1)
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#define LAPD_ADDR_EA(addr) ((addr) & 0x1)
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#define LAPD_ADDR_TEI(addr) ((addr) >> 1)
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#define LAPD_CTRL_I4(ns) (((ns) & 0x7f) << 1)
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#define LAPD_CTRL_I5(nr, p) ((((nr) & 0x7f) << 1) | ((p) & 0x1))
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#define LAPD_CTRL_S4(s) ((((s) & 0x3) << 2) | 0x1)
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#define LAPD_CTRL_S5(nr, p) ((((nr) & 0x7f) << 1) | ((p) & 0x1))
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#define LAPD_CTRL_U4(u, p) ((((u) & 0x1c) << (5-2)) | (((p) & 0x1) << 4) | (((u) & 0x3) << 2) | 0x3)
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#define LAPD_CTRL_is_I(ctrl) (((ctrl) & 0x1) == 0)
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#define LAPD_CTRL_is_S(ctrl) (((ctrl) & 0x3) == 1)
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#define LAPD_CTRL_is_U(ctrl) (((ctrl) & 0x3) == 3)
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#define LAPD_CTRL_U_BITS(ctrl) ((((ctrl) & 0xC) >> 2) | ((ctrl) & 0xE0) >> 3)
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#define LAPD_CTRL_U_PF(ctrl) (((ctrl) >> 4) & 0x1)
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#define LAPD_CTRL_S_BITS(ctrl) (((ctrl) & 0xC) >> 2)
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#define LAPD_CTRL_S_PF(ctrl) (ctrl & 0x1)
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#define LAPD_CTRL_I_Ns(ctrl) (((ctrl) & 0xFE) >> 1)
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#define LAPD_CTRL_I_P(ctrl) (ctrl & 0x1)
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#define LAPD_CTRL_Nr(ctrl) (((ctrl) & 0xFE) >> 1)
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#define LAPD_LEN(len) ((len << 2) | 0x1)
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#define LAPD_EL 0x1
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#define LAPD_SET_K(n, o) {n,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o}
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#define LOGLI(li, level, fmt, args ...) \
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LOGP(DLLAPD, level, "(%s): " fmt, (li)->name, ## args)
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#define LOGTEI(teip, level, fmt, args ...) \
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LOGP(DLLAPD, level, "(%s-T%u): " fmt, (teip)->li->name, (teip)->tei, ## args)
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#define LOGSAP(sap, level, fmt, args ...) \
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LOGP(DLLAPD, level, "(%s): " fmt, (sap)->dl.name, ## args)
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#define DLSAP_MSGB_SIZE 128
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#define DLSAP_MSGB_HEADROOM 56
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const struct lapd_profile lapd_profile_lapv5dl = {
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.k = LAPD_SET_K(7,7),
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.n200 = 3,
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.n201 = 260,
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.n202 = 3,
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.t200_sec = 1, .t200_usec = 0,
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.t203_sec = 10, .t203_usec = 0,
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.short_address = 0
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};
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typedef enum {
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LAPD_TEI_NONE = 0,
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LAPD_TEI_ASSIGNED,
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LAPD_TEI_ACTIVE,
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} lapd_tei_state;
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const char *lapd_tei_states[] = {
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"NONE",
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"ASSIGNED",
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"ACTIVE",
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};
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/* Structure representing an allocated TEI within a LAPD instance. */
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struct lapd_tei {
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struct llist_head list;
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struct lapd_instance *li;
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uint8_t tei;
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lapd_tei_state state;
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struct llist_head sap_list;
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};
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/* Structure representing a SAP within a TEI. It includes exactly one datalink
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* instance. */
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struct lapd_sap {
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struct llist_head list;
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struct lapd_tei *tei;
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uint8_t sapi;
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struct lapd_datalink dl;
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};
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/* Resolve TEI structure from given numeric TEI */
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static struct lapd_tei *teip_from_tei(struct lapd_instance *li, uint8_t tei)
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{
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struct lapd_tei *lt;
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llist_for_each_entry(lt, &li->tei_list, list) {
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if (lt->tei == tei)
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return lt;
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}
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return NULL;
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};
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/* Change state of TEI */
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static void lapd_tei_set_state(struct lapd_tei *teip, int newstate)
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{
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LOGTEI(teip, LOGL_INFO, "LAPD state change on TEI %d: %s -> %s\n",
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teip->tei, lapd_tei_states[teip->state],
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lapd_tei_states[newstate]);
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teip->state = newstate;
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};
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/* Allocate a new TEI */
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struct lapd_tei *lapd_tei_alloc(struct lapd_instance *li, uint8_t tei)
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{
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struct lapd_tei *teip;
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teip = talloc_zero(li, struct lapd_tei);
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if (!teip)
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return NULL;
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teip->li = li;
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teip->tei = tei;
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llist_add(&teip->list, &li->tei_list);
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INIT_LLIST_HEAD(&teip->sap_list);
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lapd_tei_set_state(teip, LAPD_TEI_ASSIGNED);
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return teip;
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}
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/* Find a SAP within a given TEI */
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static struct lapd_sap *lapd_sap_find(struct lapd_tei *teip, uint8_t sapi)
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{
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struct lapd_sap *sap;
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llist_for_each_entry(sap, &teip->sap_list, list) {
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if (sap->sapi == sapi)
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return sap;
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}
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return NULL;
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}
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static int send_ph_data_req(struct lapd_msg_ctx *lctx, struct msgb *msg);
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static int send_dlsap(struct osmo_dlsap_prim *dp, struct lapd_msg_ctx *lctx);
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/* Allocate a new SAP within a given TEI */
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static struct lapd_sap *lapd_sap_alloc(struct lapd_tei *teip, uint8_t sapi)
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{
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struct lapd_sap *sap;
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struct lapd_datalink *dl;
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struct lapd_instance *li = teip->li;
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struct lapd_profile *profile;
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char name[256];
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int k;
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snprintf(name, sizeof(name), "%s-T%u-S%u", li->name, teip->tei, sapi);
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sap = talloc_zero(teip, struct lapd_sap);
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if (!sap)
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return NULL;
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LOGP(DLLAPD, LOGL_NOTICE,
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"(%s): LAPD Allocating SAP for SAPI=%u / TEI=%u (dl=%p, sap=%p)\n",
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name, sapi, teip->tei, &sap->dl, sap);
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sap->sapi = sapi;
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sap->tei = teip;
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dl = &sap->dl;
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profile = &li->profile;
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k = profile->k[sapi & 0x3f];
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LOGP(DLLAPD, LOGL_NOTICE, "(%s): k=%d N200=%d N201=%d T200=%d.%d T203=%d.%d\n",
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name, k, profile->n200, profile->n201, profile->t200_sec,
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profile->t200_usec, profile->t203_sec, profile->t203_usec);
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lapd_dl_init2(dl, k, 128, profile->n201, name);
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dl->use_sabme = 1; /* use SABME instead of SABM (GSM) */
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dl->send_ph_data_req = send_ph_data_req;
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dl->send_dlsap = send_dlsap;
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dl->n200 = profile->n200;
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dl->n200_est_rel = profile->n200;
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dl->t200_sec = profile->t200_sec; dl->t200_usec = profile->t200_usec;
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dl->t203_sec = profile->t203_sec; dl->t203_usec = profile->t203_usec;
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dl->lctx.dl = &sap->dl;
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dl->lctx.sapi = sapi;
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dl->lctx.tei = teip->tei;
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dl->lctx.n201 = profile->n201;
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lapd_set_mode(&sap->dl, (teip->li->network_side) ? LAPD_MODE_NETWORK
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: LAPD_MODE_USER);
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llist_add(&sap->list, &teip->sap_list);
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return sap;
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}
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/* Free SAP instance, including the datalink */
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static void lapd_sap_free(struct lapd_sap *sap)
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{
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LOGSAP(sap, LOGL_NOTICE,
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"LAPD Freeing SAP for SAPI=%u / TEI=%u (dl=%p, sap=%p)\n",
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sap->sapi, sap->tei->tei, &sap->dl, sap);
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/* free datalink structures and timers */
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lapd_dl_exit(&sap->dl);
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llist_del(&sap->list);
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talloc_free(sap);
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}
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/* Free TEI instance */
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static void lapd_tei_free(struct lapd_tei *teip)
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{
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struct lapd_sap *sap, *sap2;
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llist_for_each_entry_safe(sap, sap2, &teip->sap_list, list) {
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lapd_sap_free(sap);
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}
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llist_del(&teip->list);
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talloc_free(teip);
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}
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/* Input function into TEI manager */
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static int lapd_tei_receive(struct lapd_instance *li, uint8_t *data, int len)
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{
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uint8_t entity;
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uint8_t ref;
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uint8_t mt;
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uint8_t action;
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uint8_t e;
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uint8_t resp[8];
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struct lapd_tei *teip;
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struct msgb *msg;
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if (len < 5) {
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LOGLI(li, LOGL_ERROR, "LAPD TEIMGR frame receive len %d < 5"
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", ignoring\n", len);
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return -EINVAL;
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};
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entity = data[0];
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ref = data[1];
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mt = data[3];
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action = data[4] >> 1;
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e = data[4] & 1;
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DEBUGP(DLLAPD, "LAPD TEIMGR: entity %x, ref %x, mt %x, action %x, "
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"e %x\n", entity, ref, mt, action, e);
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switch (mt) {
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case 0x01: /* IDENTITY REQUEST */
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DEBUGP(DLLAPD, "LAPD TEIMGR: identity request for TEI %u\n",
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action);
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teip = teip_from_tei(li, action);
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if (!teip) {
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LOGLI(li, LOGL_INFO, "TEI MGR: New TEI %u\n",
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action);
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teip = lapd_tei_alloc(li, action);
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if (!teip)
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return -ENOMEM;
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}
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/* Send ACCEPT */
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memmove(resp, "\xfe\xff\x03\x0f\x00\x00\x02\x00", 8);
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resp[7] = (action << 1) | 1;
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msg = msgb_alloc_headroom(DLSAP_MSGB_SIZE, DLSAP_MSGB_HEADROOM, "DL EST");
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msg->l2h = msgb_push(msg, 8);
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memcpy(msg->l2h, resp, 8);
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/* write to PCAP file, if enabled. */
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osmo_pcap_lapd_write(li->pcap_fd, OSMO_LAPD_PCAP_OUTPUT, msg);
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LOGTEI(teip, LOGL_DEBUG, "TX: %s\n", osmo_hexdump(msg->data, msg->len));
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li->transmit_cb(msg, li->transmit_cbdata);
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if (teip->state == LAPD_TEI_NONE)
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lapd_tei_set_state(teip, LAPD_TEI_ASSIGNED);
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break;
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default:
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LOGLI(li, LOGL_NOTICE, "LAPD TEIMGR: unknown mt %x action %x\n", mt, action);
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break;
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};
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return 0;
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}
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/* General input function for any data received for this LAPD instance */
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int lapd_receive(struct lapd_instance *li, struct msgb *msg, int *error)
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{
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int i;
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struct lapd_msg_ctx lctx;
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int rc;
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struct lapd_sap *sap;
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struct lapd_tei *teip;
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/* write to PCAP file, if enabled. */
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osmo_pcap_lapd_write(li->pcap_fd, OSMO_LAPD_PCAP_INPUT, msg);
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LOGLI(li, LOGL_DEBUG, "RX: %s\n", osmo_hexdump(msg->data, msg->len));
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if (msg->len < 2) {
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LOGLI(li, LOGL_ERROR, "LAPD frame receive len %d < 2, ignoring\n", msg->len);
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*error = LAPD_ERR_BAD_LEN;
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return -EINVAL;
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};
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msg->l2h = msg->data;
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memset(&lctx, 0, sizeof(lctx));
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i = 0;
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/* adress field */
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lctx.sapi = LAPD_ADDR_SAPI(msg->l2h[i]);
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lctx.cr = LAPD_ADDR_CR(msg->l2h[i]);
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lctx.lpd = 0;
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if (!LAPD_ADDR_EA(msg->l2h[i])) {
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if (msg->len < 3) {
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LOGLI(li, LOGL_ERROR, "LAPD frame with TEI receive "
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"len %d < 3, ignoring\n", msg->len);
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*error = LAPD_ERR_BAD_LEN;
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return -EINVAL;
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};
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i++;
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lctx.tei = LAPD_ADDR_TEI(msg->l2h[i]);
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}
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i++;
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/* control field */
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if (LAPD_CTRL_is_I(msg->l2h[i])) {
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lctx.format = LAPD_FORM_I;
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lctx.n_send = LAPD_CTRL_I_Ns(msg->l2h[i]);
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i++;
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if (msg->len < 3 && i == 2) {
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LOGLI(li, LOGL_ERROR, "LAPD I frame without TEI "
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"receive len %d < 3, ignoring\n", msg->len);
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*error = LAPD_ERR_BAD_LEN;
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return -EINVAL;
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};
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if (msg->len < 4 && i == 3) {
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LOGLI(li, LOGL_ERROR, "LAPD I frame with TEI "
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"receive len %d < 4, ignoring\n", msg->len);
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*error = LAPD_ERR_BAD_LEN;
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return -EINVAL;
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};
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lctx.n_recv = LAPD_CTRL_Nr(msg->l2h[i]);
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lctx.p_f = LAPD_CTRL_I_P(msg->l2h[i]);
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} else if (LAPD_CTRL_is_S(msg->l2h[i])) {
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lctx.format = LAPD_FORM_S;
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lctx.s_u = LAPD_CTRL_S_BITS(msg->l2h[i]);
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i++;
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if (msg->len < 3 && i == 2) {
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LOGLI(li, LOGL_ERROR, "LAPD S frame without TEI "
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"receive len %d < 3, ignoring\n", msg->len);
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*error = LAPD_ERR_BAD_LEN;
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return -EINVAL;
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};
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if (msg->len < 4 && i == 3) {
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LOGLI(li, LOGL_ERROR, "LAPD S frame with TEI "
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"receive len %d < 4, ignoring\n", msg->len);
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*error = LAPD_ERR_BAD_LEN;
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return -EINVAL;
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};
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lctx.n_recv = LAPD_CTRL_Nr(msg->l2h[i]);
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lctx.p_f = LAPD_CTRL_S_PF(msg->l2h[i]);
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} else if (LAPD_CTRL_is_U(msg->l2h[i])) {
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lctx.format = LAPD_FORM_U;
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lctx.s_u = LAPD_CTRL_U_BITS(msg->l2h[i]);
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lctx.p_f = LAPD_CTRL_U_PF(msg->l2h[i]);
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} else
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lctx.format = LAPD_FORM_UKN;
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i++;
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/* length */
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msg->l3h = msg->l2h + i;
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msgb_pull(msg, i);
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lctx.length = msg->len;
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/* perform TEI assignment, if received */
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if (lctx.tei == 127) {
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rc = lapd_tei_receive(li, msg->data, msg->len);
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msgb_free(msg);
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return rc;
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}
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/* resolve TEI and SAPI */
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teip = teip_from_tei(li, lctx.tei);
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if (!teip) {
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LOGLI(li, LOGL_NOTICE, "LAPD Unknown TEI %u\n", lctx.tei);
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*error = LAPD_ERR_UNKNOWN_TEI;
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msgb_free(msg);
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return -EINVAL;
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}
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sap = lapd_sap_find(teip, lctx.sapi);
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if (!sap) {
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LOGTEI(teip, LOGL_INFO, "LAPD No SAP for TEI=%u / SAPI=%u, "
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"allocating\n", lctx.tei, lctx.sapi);
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sap = lapd_sap_alloc(teip, lctx.sapi);
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if (!sap) {
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*error = LAPD_ERR_NO_MEM;
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msgb_free(msg);
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return -ENOMEM;
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}
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}
|
|
lctx.dl = &sap->dl;
|
|
lctx.n201 = lctx.dl->maxf;
|
|
|
|
if (msg->len > lctx.n201) {
|
|
LOGSAP(sap, LOGL_ERROR, "message len %d > N201(%d) "
|
|
"(discarding)\n", msg->len, lctx.n201);
|
|
msgb_free(msg);
|
|
*error = LAPD_ERR_BAD_LEN;
|
|
return -EINVAL;
|
|
}
|
|
|
|
/* send to LAPD */
|
|
return lapd_ph_data_ind(msg, &lctx);
|
|
}
|
|
|
|
/* Start a (user-side) SAP for the specified TEI/SAPI on the LAPD instance */
|
|
int lapd_sap_start(struct lapd_instance *li, uint8_t tei, uint8_t sapi)
|
|
{
|
|
struct lapd_sap *sap;
|
|
struct lapd_tei *teip;
|
|
struct osmo_dlsap_prim dp;
|
|
struct msgb *msg;
|
|
|
|
teip = teip_from_tei(li, tei);
|
|
if (!teip)
|
|
teip = lapd_tei_alloc(li, tei);
|
|
|
|
sap = lapd_sap_find(teip, sapi);
|
|
if (sap)
|
|
return -EEXIST;
|
|
|
|
sap = lapd_sap_alloc(teip, sapi);
|
|
if (!sap)
|
|
return -ENOMEM;
|
|
|
|
LOGSAP(sap, LOGL_NOTICE, "LAPD DL-ESTABLISH request TEI=%d SAPI=%d\n", tei, sapi);
|
|
|
|
/* prepare prim */
|
|
msg = msgb_alloc_headroom(DLSAP_MSGB_SIZE, DLSAP_MSGB_HEADROOM, "DL EST");
|
|
msg->l3h = msg->data;
|
|
osmo_prim_init(&dp.oph, 0, PRIM_DL_EST, PRIM_OP_REQUEST, msg);
|
|
|
|
/* send to L2 */
|
|
return lapd_recv_dlsap(&dp, &sap->dl.lctx);
|
|
}
|
|
|
|
/* Stop a (user-side) SAP for the specified TEI/SAPI on the LAPD instance */
|
|
int lapd_sap_stop(struct lapd_instance *li, uint8_t tei, uint8_t sapi)
|
|
{
|
|
struct lapd_tei *teip;
|
|
struct lapd_sap *sap;
|
|
struct osmo_dlsap_prim dp;
|
|
struct msgb *msg;
|
|
|
|
teip = teip_from_tei(li, tei);
|
|
if (!teip)
|
|
return -ENODEV;
|
|
|
|
sap = lapd_sap_find(teip, sapi);
|
|
if (!sap)
|
|
return -ENODEV;
|
|
|
|
LOGSAP(sap, LOGL_NOTICE, "LAPD DL-RELEASE request TEI=%d SAPI=%d\n", tei, sapi);
|
|
|
|
/* prepare prim */
|
|
msg = msgb_alloc_headroom(DLSAP_MSGB_SIZE, DLSAP_MSGB_HEADROOM, "DL REL");
|
|
msg->l3h = msg->data;
|
|
osmo_prim_init(&dp.oph, 0, PRIM_DL_REL, PRIM_OP_REQUEST, msg);
|
|
|
|
/* send to L2 */
|
|
return lapd_recv_dlsap(&dp, &sap->dl.lctx);
|
|
}
|
|
|
|
/* Transmit Data (DL-DATA request) on the given LAPD Instance / TEI / SAPI */
|
|
void lapd_transmit(struct lapd_instance *li, uint8_t tei, uint8_t sapi,
|
|
struct msgb *msg)
|
|
{
|
|
struct lapd_tei *teip = teip_from_tei(li, tei);
|
|
struct lapd_sap *sap;
|
|
struct osmo_dlsap_prim dp;
|
|
|
|
if (!teip) {
|
|
LOGLI(li, LOGL_ERROR, "LAPD Cannot transmit on non-existing TEI %u\n", tei);
|
|
msgb_free(msg);
|
|
return;
|
|
}
|
|
|
|
sap = lapd_sap_find(teip, sapi);
|
|
if (!sap) {
|
|
LOGTEI(teip, LOGL_INFO, "LAPD Tx on unknown SAPI=%u in TEI=%u\n", sapi, tei);
|
|
msgb_free(msg);
|
|
return;
|
|
}
|
|
|
|
/* prepare prim */
|
|
msg->l3h = msg->data;
|
|
osmo_prim_init(&dp.oph, 0, PRIM_DL_DATA, PRIM_OP_REQUEST, msg);
|
|
|
|
/* send to L2 */
|
|
lapd_recv_dlsap(&dp, &sap->dl.lctx);
|
|
};
|
|
|
|
static int send_ph_data_req(struct lapd_msg_ctx *lctx, struct msgb *msg)
|
|
{
|
|
struct lapd_datalink *dl = lctx->dl;
|
|
struct lapd_sap *sap =
|
|
container_of(dl, struct lapd_sap, dl);
|
|
struct lapd_instance *li = sap->tei->li;
|
|
int format = lctx->format;
|
|
int addr_len;
|
|
|
|
/* control field */
|
|
switch (format) {
|
|
case LAPD_FORM_I:
|
|
msg->l2h = msgb_push(msg, 2);
|
|
msg->l2h[0] = LAPD_CTRL_I4(lctx->n_send);
|
|
msg->l2h[1] = LAPD_CTRL_I5(lctx->n_recv, lctx->p_f);
|
|
break;
|
|
case LAPD_FORM_S:
|
|
msg->l2h = msgb_push(msg, 2);
|
|
msg->l2h[0] = LAPD_CTRL_S4(lctx->s_u);
|
|
msg->l2h[1] = LAPD_CTRL_S5(lctx->n_recv, lctx->p_f);
|
|
break;
|
|
case LAPD_FORM_U:
|
|
msg->l2h = msgb_push(msg, 1);
|
|
msg->l2h[0] = LAPD_CTRL_U4(lctx->s_u, lctx->p_f);
|
|
break;
|
|
default:
|
|
msgb_free(msg);
|
|
return -EINVAL;
|
|
}
|
|
/* address field */
|
|
if (li->profile.short_address && lctx->tei == 0)
|
|
addr_len = 1;
|
|
else
|
|
addr_len = 2;
|
|
msg->l2h = msgb_push(msg, addr_len);
|
|
msg->l2h[0] = LAPD_ADDR2(lctx->sapi, lctx->cr);
|
|
if (addr_len == 1)
|
|
msg->l2h[0] |= 0x1;
|
|
else
|
|
msg->l2h[1] = LAPD_ADDR3(lctx->tei);
|
|
|
|
/* write to PCAP file, if enabled. */
|
|
osmo_pcap_lapd_write(li->pcap_fd, OSMO_LAPD_PCAP_OUTPUT, msg);
|
|
|
|
/* forward frame to L1 */
|
|
LOGDL(dl, LOGL_DEBUG, "TX: %s\n", osmo_hexdump(msg->data, msg->len));
|
|
li->transmit_cb(msg, li->transmit_cbdata);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/* A DL-SAP message is received from datalink instance and forwarded to L3 */
|
|
static int send_dlsap(struct osmo_dlsap_prim *dp, struct lapd_msg_ctx *lctx)
|
|
{
|
|
struct lapd_datalink *dl = lctx->dl;
|
|
struct lapd_sap *sap =
|
|
container_of(dl, struct lapd_sap, dl);
|
|
struct lapd_instance *li;
|
|
uint8_t tei, sapi;
|
|
char *op = (dp->oph.operation == PRIM_OP_INDICATION) ? "indication"
|
|
: "confirm";
|
|
|
|
li = sap->tei->li;
|
|
tei = lctx->tei;
|
|
sapi = lctx->sapi;
|
|
|
|
switch (dp->oph.primitive) {
|
|
case PRIM_DL_EST:
|
|
LOGDL(dl, LOGL_NOTICE, "LAPD DL-ESTABLISH %s TEI=%d "
|
|
"SAPI=%d\n", op, lctx->tei, lctx->sapi);
|
|
break;
|
|
case PRIM_DL_REL:
|
|
LOGDL(dl, LOGL_NOTICE, "LAPD DL-RELEASE %s TEI=%d "
|
|
"SAPI=%d\n", op, lctx->tei, lctx->sapi);
|
|
lapd_sap_free(sap);
|
|
/* note: sap and dl is now gone, don't use it anymore */
|
|
break;
|
|
default:
|
|
;
|
|
}
|
|
|
|
li->receive_cb(dp, tei, sapi, li->receive_cbdata);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/* Allocate a new LAPD instance */
|
|
struct lapd_instance *lapd_instance_alloc2(int network_side,
|
|
void (*tx_cb)(struct msgb *msg, void *cbdata), void *tx_cbdata,
|
|
void (*rx_cb)(struct osmo_dlsap_prim *odp, uint8_t tei, uint8_t sapi,
|
|
void *rx_cbdata), void *rx_cbdata,
|
|
const struct lapd_profile *profile, const char *name)
|
|
{
|
|
struct lapd_instance *li;
|
|
|
|
li = talloc_zero(NULL, struct lapd_instance);
|
|
if (!li)
|
|
return NULL;
|
|
|
|
li->network_side = network_side;
|
|
li->transmit_cb = tx_cb;
|
|
li->transmit_cbdata = tx_cbdata;
|
|
li->receive_cb = rx_cb;
|
|
li->receive_cbdata = rx_cbdata;
|
|
li->pcap_fd = -1;
|
|
li->name = talloc_strdup(li, name);
|
|
memcpy(&li->profile, profile, sizeof(li->profile));
|
|
|
|
INIT_LLIST_HEAD(&li->tei_list);
|
|
|
|
return li;
|
|
}
|
|
|
|
struct lapd_instance *lapd_instance_alloc(int network_side,
|
|
void (*tx_cb)(struct msgb *msg, void *cbdata), void *tx_cbdata,
|
|
void (*rx_cb)(struct osmo_dlsap_prim *odp, uint8_t tei, uint8_t sapi,
|
|
void *rx_cbdata), void *rx_cbdata,
|
|
const struct lapd_profile *profile)
|
|
{
|
|
return lapd_instance_alloc2(network_side, tx_cbdata, tx_cb, rx_cb, rx_cbdata, profile, NULL);
|
|
}
|
|
|
|
|
|
/* Change lapd-profile on the fly (use with caution!) */
|
|
void lapd_instance_set_profile(struct lapd_instance *li,
|
|
const struct lapd_profile *profile)
|
|
{
|
|
memcpy(&li->profile, profile, sizeof(li->profile));
|
|
}
|
|
|
|
void lapd_instance_free(struct lapd_instance *li)
|
|
{
|
|
struct lapd_tei *teip, *teip2;
|
|
|
|
/* Free all TEI instances */
|
|
llist_for_each_entry_safe(teip, teip2, &li->tei_list, list) {
|
|
lapd_tei_free(teip);
|
|
}
|
|
|
|
talloc_free(li);
|
|
}
|
|
|
|
/***********************************************************************
|
|
* LAPV5-EF (Encapsulation Function)
|
|
***********************************************************************/
|
|
|
|
/* The LAPV5-EF adds another layer around of the LAPD-style LAPV5-DL. It consists of
|
|
* a two-byte header in front of the normal data link header. Examples see Figure E.1/G.964 */
|
|
|
|
|
|
/* main entry point for receiving signaling frames from the AN. The assumption is that
|
|
* the flag octets are removed and the msg->data points to the first octet of the EFaddr,
|
|
* while the last octet (before msg->tail) points to the last FCS octet. */
|
|
int lapv5ef_rx(struct v5x_link *link, struct msgb *msg)
|
|
{
|
|
uint16_t efaddr, efaddr_enc;
|
|
bool is_isdn;
|
|
|
|
msg->l1h = msg->data;
|
|
|
|
if (msgb_length(msg) < 2) {
|
|
msgb_free(msg);
|
|
return -EINVAL;
|
|
}
|
|
|
|
msg->l2h = msg->l1h + 2;
|
|
efaddr_enc = msg->l1h[0] << 8 | msg->l1h[1];
|
|
efaddr = v51_l3_addr_dec(efaddr_enc, &is_isdn);
|
|
|
|
if (!is_isdn) {
|
|
/* EFaddr are structured like isdn-type L3 Address */
|
|
msgb_free(msg);
|
|
return -EINVAL;
|
|
}
|
|
|
|
switch (efaddr) {
|
|
case V51_DLADDR_PSTN:
|
|
/* hand-over to LAPD-DL instance for PSTN */
|
|
break;
|
|
case V51_DLADDR_CTRL:
|
|
/* hand-over to LAPD-DL instance for CTRL */
|
|
break;
|
|
case V52_DLADDR_BCC:
|
|
case V52_DLADDR_PROTECTION:
|
|
case V52_DLADDR_LCP:
|
|
/* TOOD: implement V5.2 */
|
|
msgb_free(msg);
|
|
break;
|
|
default:
|
|
if (efaddr >= 8176) {
|
|
/* reserved as per Section 9.2.2.2 of G.964 */
|
|
msgb_free(msg);
|
|
return -EINVAL;
|
|
}
|
|
/* relay function for LAPD of user ports */
|
|
}
|
|
}
|