Common library for all Osmocom projects (libosmocore, libosmogsm, libosmovty, libosmogb, libosmosim, libosmousb, ...) https://osmocom.org/projects/libosmocore
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libosmocore/src/gb/gprs_ns.c

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/* GPRS Networks Service (NS) messages on the Gb interface
* 3GPP TS 08.16 version 8.0.1 Release 1999 / ETSI TS 101 299 V8.0.1 (2002-05) */
/* (C) 2009-2012 by Harald Welte <laforge@gnumonks.org>
*
* All Rights Reserved
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as published by
* the Free Software Foundation; either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
*/
/*! \addtogroup libgb
* @{
*/
/*! \file gprs_ns.c */
/*!
* GPRS Networks Service (NS) messages on the Gb interface
* 3GPP TS 08.16 version 8.0.1 Release 1999 / ETSI TS 101 299 V8.0.1 (2002-05)
*
* Some introduction into NS: NS is used typically on top of frame relay,
* but in the ip.access world it is encapsulated in UDP packets. It serves
* as an intermediate shim betwen BSSGP and the underlying medium. It doesn't
* do much, apart from providing congestion notification and status indication.
*
* Terms:
* NS Network Service
* NSVC NS Virtual Connection
* NSEI NS Entity Identifier
* NSVL NS Virtual Link
* NSVLI NS Virtual Link Identifier
* BVC BSSGP Virtual Connection
* BVCI BSSGP Virtual Connection Identifier
* NSVCG NS Virtual Connection Goup
* Blocked NS-VC cannot be used for user traffic
* Alive Ability of a NS-VC to provide communication
*
* There can be multiple BSSGP virtual connections over one (group of) NSVC's. BSSGP will
* therefore identify the BSSGP virtual connection by a BVCI passed down to NS.
* NS then has to firgure out which NSVC's are responsible for this BVCI.
* Those mappings are administratively configured.
*/
/* This implementation has the following limitations:
* o Only one NS-VC for each NSE: No load-sharing function
* o NSVCI 65535 and 65534 are reserved for internal use
* o Only UDP is supported as of now, no frame relay support
* o The IP Sub-Network-Service (SNS) as specified in 48.016 is not implemented
* o There are no BLOCK and UNBLOCK timers (yet?)
*/
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <stdint.h>
#include <arpa/inet.h>
#include <osmocom/core/msgb.h>
#include <osmocom/gsm/tlv.h>
#include <osmocom/core/talloc.h>
#include <osmocom/core/select.h>
#include <osmocom/core/rate_ctr.h>
#include <osmocom/core/socket.h>
#include <osmocom/core/signal.h>
#include <osmocom/gprs/gprs_ns.h>
#include <osmocom/gprs/gprs_bssgp.h>
#include <osmocom/gprs/gprs_ns_frgre.h>
#include "common_vty.h"
static const struct tlv_definition ns_att_tlvdef = {
.def = {
[NS_IE_CAUSE] = { TLV_TYPE_TvLV, 0 },
[NS_IE_VCI] = { TLV_TYPE_TvLV, 0 },
[NS_IE_PDU] = { TLV_TYPE_TvLV, 0 },
[NS_IE_BVCI] = { TLV_TYPE_TvLV, 0 },
[NS_IE_NSEI] = { TLV_TYPE_TvLV, 0 },
},
};
enum ns_ctr {
NS_CTR_PKTS_IN,
NS_CTR_PKTS_OUT,
NS_CTR_BYTES_IN,
NS_CTR_BYTES_OUT,
NS_CTR_BLOCKED,
NS_CTR_DEAD,
};
static const struct rate_ctr_desc nsvc_ctr_description[] = {
{ "packets.in", "Packets at NS Level ( In)" },
{ "packets.out","Packets at NS Level (Out)" },
{ "bytes.in", "Bytes at NS Level ( In)" },
{ "bytes.out", "Bytes at NS Level (Out)" },
{ "blocked", "NS-VC Block count " },
{ "dead", "NS-VC gone dead count " },
};
static const struct rate_ctr_group_desc nsvc_ctrg_desc = {
.group_name_prefix = "ns.nsvc",
.group_description = "NSVC Peer Statistics",
.num_ctr = ARRAY_SIZE(nsvc_ctr_description),
.ctr_desc = nsvc_ctr_description,
};
/*! \brief Lookup struct gprs_nsvc based on NSVCI
* \param[in] nsi NS instance in which to search
* \param[in] nsvci NSVCI to be searched
* \returns gprs_nsvc of respective NSVCI
*/
struct gprs_nsvc *gprs_nsvc_by_nsvci(struct gprs_ns_inst *nsi, uint16_t nsvci)
{
struct gprs_nsvc *nsvc;
llist_for_each_entry(nsvc, &nsi->gprs_nsvcs, list) {
if (nsvc->nsvci == nsvci)
return nsvc;
}
return NULL;
}
/*! \brief Lookup struct gprs_nsvc based on NSEI
* \param[in] nsi NS instance in which to search
* \param[in] nsei NSEI to be searched
* \returns gprs_nsvc of respective NSEI
*/
struct gprs_nsvc *gprs_nsvc_by_nsei(struct gprs_ns_inst *nsi, uint16_t nsei)
{
struct gprs_nsvc *nsvc;
llist_for_each_entry(nsvc, &nsi->gprs_nsvcs, list) {
if (nsvc->nsei == nsei)
return nsvc;
}
return NULL;
}
/* Lookup struct gprs_nsvc based on remote peer socket addr */
static struct gprs_nsvc *nsvc_by_rem_addr(struct gprs_ns_inst *nsi,
struct sockaddr_in *sin)
{
struct gprs_nsvc *nsvc;
llist_for_each_entry(nsvc, &nsi->gprs_nsvcs, list) {
if (nsvc->ip.bts_addr.sin_addr.s_addr ==
sin->sin_addr.s_addr &&
nsvc->ip.bts_addr.sin_port == sin->sin_port)
return nsvc;
}
return NULL;
}
static void gprs_ns_timer_cb(void *data);
struct gprs_nsvc *gprs_nsvc_create(struct gprs_ns_inst *nsi, uint16_t nsvci)
{
struct gprs_nsvc *nsvc;
LOGP(DNS, LOGL_INFO, "NSVCI=%u Creating NS-VC\n", nsvci);
nsvc = talloc_zero(nsi, struct gprs_nsvc);
nsvc->nsvci = nsvci;
/* before RESET procedure: BLOCKED and DEAD */
nsvc->state = NSE_S_BLOCKED;
nsvc->nsi = nsi;
nsvc->timer.cb = gprs_ns_timer_cb;
nsvc->timer.data = nsvc;
nsvc->ctrg = rate_ctr_group_alloc(nsvc, &nsvc_ctrg_desc, nsvci);
llist_add(&nsvc->list, &nsi->gprs_nsvcs);
return nsvc;
}
/*! \brief Delete given NS-VC
* \param[in] nsvc gprs_nsvc to be deleted
*/
void gprs_nsvc_delete(struct gprs_nsvc *nsvc)
{
if (osmo_timer_pending(&nsvc->timer))
osmo_timer_del(&nsvc->timer);
llist_del(&nsvc->list);
talloc_free(nsvc);
}
static void ns_osmo_signal_dispatch(struct gprs_nsvc *nsvc, unsigned int signal,
uint8_t cause)
{
struct ns_signal_data nssd;
nssd.nsvc = nsvc;
nssd.cause = cause;
osmo_signal_dispatch(SS_L_NS, signal, &nssd);
}
/* Section 10.3.2, Table 13 */
static const struct value_string ns_cause_str[] = {
{ NS_CAUSE_TRANSIT_FAIL, "Transit network failure" },
{ NS_CAUSE_OM_INTERVENTION, "O&M intervention" },
{ NS_CAUSE_EQUIP_FAIL, "Equipment failure" },
{ NS_CAUSE_NSVC_BLOCKED, "NS-VC blocked" },
{ NS_CAUSE_NSVC_UNKNOWN, "NS-VC unknown" },
{ NS_CAUSE_BVCI_UNKNOWN, "BVCI unknown" },
{ NS_CAUSE_SEM_INCORR_PDU, "Semantically incorrect PDU" },
{ NS_CAUSE_PDU_INCOMP_PSTATE, "PDU not compatible with protocol state" },
{ NS_CAUSE_PROTO_ERR_UNSPEC, "Protocol error, unspecified" },
{ NS_CAUSE_INVAL_ESSENT_IE, "Invalid essential IE" },
{ NS_CAUSE_MISSING_ESSENT_IE, "Missing essential IE" },
{ 0, NULL }
};
/*! \brief Obtain a human-readable string for NS cause value */
const char *gprs_ns_cause_str(enum ns_cause cause)
{
return get_value_string(ns_cause_str, cause);
}
static int nsip_sendmsg(struct gprs_nsvc *nsvc, struct msgb *msg);
extern int grps_ns_frgre_sendmsg(struct gprs_nsvc *nsvc, struct msgb *msg);
static int gprs_ns_tx(struct gprs_nsvc *nsvc, struct msgb *msg)
{
int ret;
log_set_context(GPRS_CTX_NSVC, nsvc);
/* Increment number of Uplink bytes */
rate_ctr_inc(&nsvc->ctrg->ctr[NS_CTR_PKTS_OUT]);
rate_ctr_add(&nsvc->ctrg->ctr[NS_CTR_BYTES_OUT], msgb_l2len(msg));
switch (nsvc->ll) {
case GPRS_NS_LL_UDP:
ret = nsip_sendmsg(nsvc, msg);
break;
case GPRS_NS_LL_FR_GRE:
ret = gprs_ns_frgre_sendmsg(nsvc, msg);
break;
default:
LOGP(DNS, LOGL_ERROR, "unsupported NS linklayer %u\n", nsvc->ll);
msgb_free(msg);
ret = -EIO;
break;
}
return ret;
}
static int gprs_ns_tx_simple(struct gprs_nsvc *nsvc, uint8_t pdu_type)
{
struct msgb *msg = gprs_ns_msgb_alloc();
struct gprs_ns_hdr *nsh;
log_set_context(GPRS_CTX_NSVC, nsvc);
if (!msg)
return -ENOMEM;
msg->l2h = msgb_put(msg, sizeof(*nsh));
nsh = (struct gprs_ns_hdr *) msg->l2h;
nsh->pdu_type = pdu_type;
return gprs_ns_tx(nsvc, msg);
}
/*! \brief Transmit a NS-RESET on a given NSVC
* \param[in] nsvc NS-VC used for transmission
* \paam[in] cause Numeric NS cause value
*/
int gprs_ns_tx_reset(struct gprs_nsvc *nsvc, uint8_t cause)
{
struct msgb *msg = gprs_ns_msgb_alloc();
struct gprs_ns_hdr *nsh;
uint16_t nsvci = htons(nsvc->nsvci);
uint16_t nsei = htons(nsvc->nsei);
log_set_context(GPRS_CTX_NSVC, nsvc);
if (!msg)
return -ENOMEM;
LOGP(DNS, LOGL_INFO, "NSEI=%u Tx NS RESET (NSVCI=%u, cause=%s)\n",
nsvc->nsei, nsvc->nsvci, gprs_ns_cause_str(cause));
msg->l2h = msgb_put(msg, sizeof(*nsh));
nsh = (struct gprs_ns_hdr *) msg->l2h;
nsh->pdu_type = NS_PDUT_RESET;
msgb_tvlv_put(msg, NS_IE_CAUSE, 1, &cause);
msgb_tvlv_put(msg, NS_IE_VCI, 2, (uint8_t *) &nsvci);
msgb_tvlv_put(msg, NS_IE_NSEI, 2, (uint8_t *) &nsei);
return gprs_ns_tx(nsvc, msg);
}
/*! \brief Transmit a NS-STATUS on a given NSVC
* \param[in] nsvc NS-VC to be used for transmission
* \param[in] cause Numeric NS cause value
* \param[in] bvci BVCI to be reset within NSVC
* \param[in] orig_msg message causing the STATUS */
int gprs_ns_tx_status(struct gprs_nsvc *nsvc, uint8_t cause,
uint16_t bvci, struct msgb *orig_msg)
{
struct msgb *msg = gprs_ns_msgb_alloc();
struct gprs_ns_hdr *nsh;
uint16_t nsvci = htons(nsvc->nsvci);
log_set_context(GPRS_CTX_NSVC, nsvc);
bvci = htons(bvci);
if (!msg)
return -ENOMEM;
LOGP(DNS, LOGL_NOTICE, "NSEI=%u Tx NS STATUS (NSVCI=%u, cause=%s)\n",
nsvc->nsei, nsvc->nsvci, gprs_ns_cause_str(cause));
msg->l2h = msgb_put(msg, sizeof(*nsh));
nsh = (struct gprs_ns_hdr *) msg->l2h;
nsh->pdu_type = NS_PDUT_STATUS;
msgb_tvlv_put(msg, NS_IE_CAUSE, 1, &cause);
/* Section 9.2.7.1: Static conditions for NS-VCI */
if (cause == NS_CAUSE_NSVC_BLOCKED ||
cause == NS_CAUSE_NSVC_UNKNOWN)
msgb_tvlv_put(msg, NS_IE_VCI, 2, (uint8_t *)&nsvci);
/* Section 9.2.7.2: Static conditions for NS PDU */
switch (cause) {
case NS_CAUSE_SEM_INCORR_PDU:
case NS_CAUSE_PDU_INCOMP_PSTATE:
case NS_CAUSE_PROTO_ERR_UNSPEC:
case NS_CAUSE_INVAL_ESSENT_IE:
case NS_CAUSE_MISSING_ESSENT_IE:
msgb_tvlv_put(msg, NS_IE_PDU, msgb_l2len(orig_msg),
orig_msg->l2h);
break;
default:
break;
}
/* Section 9.2.7.3: Static conditions for BVCI */
if (cause == NS_CAUSE_BVCI_UNKNOWN)
msgb_tvlv_put(msg, NS_IE_VCI, 2, (uint8_t *)&bvci);
return gprs_ns_tx(nsvc, msg);
}
/*! \brief Transmit a NS-BLOCK on a tiven NS-VC
* \param[in] nsvc NS-VC on which the NS-BLOCK is to be transmitted
* \param[in] cause Numeric NS Cause value
* \returns 0 in case of success
*/
int gprs_ns_tx_block(struct gprs_nsvc *nsvc, uint8_t cause)
{
struct msgb *msg = gprs_ns_msgb_alloc();
struct gprs_ns_hdr *nsh;
uint16_t nsvci = htons(nsvc->nsvci);
log_set_context(GPRS_CTX_NSVC, nsvc);
if (!msg)
return -ENOMEM;
LOGP(DNS, LOGL_INFO, "NSEI=%u Tx NS BLOCK (NSVCI=%u, cause=%s)\n",
nsvc->nsei, nsvc->nsvci, gprs_ns_cause_str(cause));
/* be conservative and mark it as blocked even now! */
nsvc->state |= NSE_S_BLOCKED;
rate_ctr_inc(&nsvc->ctrg->ctr[NS_CTR_BLOCKED]);
msg->l2h = msgb_put(msg, sizeof(*nsh));
nsh = (struct gprs_ns_hdr *) msg->l2h;
nsh->pdu_type = NS_PDUT_BLOCK;
msgb_tvlv_put(msg, NS_IE_CAUSE, 1, &cause);
msgb_tvlv_put(msg, NS_IE_VCI, 2, (uint8_t *) &nsvci);
return gprs_ns_tx(nsvc, msg);
}
/*! \brief Transmit a NS-UNBLOCK on a given NS-VC
* \param[in] nsvc NS-VC on which the NS-UNBLOCK is to be transmitted
* \returns 0 in case of success
*/
int gprs_ns_tx_unblock(struct gprs_nsvc *nsvc)
{
log_set_context(GPRS_CTX_NSVC, nsvc);
LOGP(DNS, LOGL_INFO, "NSEI=%u Tx NS UNBLOCK (NSVCI=%u)\n",
nsvc->nsei, nsvc->nsvci);
return gprs_ns_tx_simple(nsvc, NS_PDUT_UNBLOCK);
}
/*! \brief Transmit a NS-ALIVE on a given NS-VC
* \param[in] nsvc NS-VC on which the NS-ALIVE is to be transmitted
* \returns 0 in case of success
*/
int gprs_ns_tx_alive(struct gprs_nsvc *nsvc)
{
log_set_context(GPRS_CTX_NSVC, nsvc);
LOGP(DNS, LOGL_DEBUG, "NSEI=%u Tx NS ALIVE (NSVCI=%u)\n",
nsvc->nsei, nsvc->nsvci);
return gprs_ns_tx_simple(nsvc, NS_PDUT_ALIVE);
}
/*! \brief Transmit a NS-ALIVE-ACK on a given NS-VC
* \param[in] nsvc NS-VC on which the NS-ALIVE-ACK is to be transmitted
* \returns 0 in case of success
*/
int gprs_ns_tx_alive_ack(struct gprs_nsvc *nsvc)
{
log_set_context(GPRS_CTX_NSVC, nsvc);
LOGP(DNS, LOGL_DEBUG, "NSEI=%u Tx NS ALIVE_ACK (NSVCI=%u)\n",
nsvc->nsei, nsvc->nsvci);
return gprs_ns_tx_simple(nsvc, NS_PDUT_ALIVE_ACK);
}
static const enum ns_timeout timer_mode_tout[_NSVC_TIMER_NR] = {
[NSVC_TIMER_TNS_RESET] = NS_TOUT_TNS_RESET,
[NSVC_TIMER_TNS_ALIVE] = NS_TOUT_TNS_ALIVE,
[NSVC_TIMER_TNS_TEST] = NS_TOUT_TNS_TEST,
};
static const struct value_string timer_mode_strs[] = {
{ NSVC_TIMER_TNS_RESET, "tns-reset" },
{ NSVC_TIMER_TNS_ALIVE, "tns-alive" },
{ NSVC_TIMER_TNS_TEST, "tns-test" },
{ 0, NULL }
};
static void nsvc_start_timer(struct gprs_nsvc *nsvc, enum nsvc_timer_mode mode)
{
enum ns_timeout tout = timer_mode_tout[mode];
unsigned int seconds = nsvc->nsi->timeout[tout];
log_set_context(GPRS_CTX_NSVC, nsvc);
DEBUGP(DNS, "NSEI=%u Starting timer in mode %s (%u seconds)\n",
nsvc->nsei, get_value_string(timer_mode_strs, mode),
seconds);
if (osmo_timer_pending(&nsvc->timer))
osmo_timer_del(&nsvc->timer);
nsvc->timer_mode = mode;
osmo_timer_schedule(&nsvc->timer, seconds, 0);
}
static void gprs_ns_timer_cb(void *data)
{
struct gprs_nsvc *nsvc = data;
enum ns_timeout tout = timer_mode_tout[nsvc->timer_mode];
unsigned int seconds = nsvc->nsi->timeout[tout];
log_set_context(GPRS_CTX_NSVC, nsvc);
DEBUGP(DNS, "NSEI=%u Timer expired in mode %s (%u seconds)\n",
nsvc->nsei, get_value_string(timer_mode_strs, nsvc->timer_mode),
seconds);
switch (nsvc->timer_mode) {
case NSVC_TIMER_TNS_ALIVE:
/* Tns-alive case: we expired without response ! */
nsvc->alive_retries++;
if (nsvc->alive_retries >
nsvc->nsi->timeout[NS_TOUT_TNS_ALIVE_RETRIES]) {
/* mark as dead and blocked */
nsvc->state = NSE_S_BLOCKED;
rate_ctr_inc(&nsvc->ctrg->ctr[NS_CTR_BLOCKED]);
rate_ctr_inc(&nsvc->ctrg->ctr[NS_CTR_DEAD]);
LOGP(DNS, LOGL_NOTICE,
"NSEI=%u Tns-alive expired more then "
"%u times, blocking NS-VC\n", nsvc->nsei,
nsvc->nsi->timeout[NS_TOUT_TNS_ALIVE_RETRIES]);
ns_osmo_signal_dispatch(nsvc, S_NS_ALIVE_EXP, 0);
ns_osmo_signal_dispatch(nsvc, S_NS_BLOCK, NS_CAUSE_NSVC_BLOCKED);
return;
}
/* Tns-test case: send NS-ALIVE PDU */
gprs_ns_tx_alive(nsvc);
/* start Tns-alive timer */
nsvc_start_timer(nsvc, NSVC_TIMER_TNS_ALIVE);
break;
case NSVC_TIMER_TNS_TEST:
/* Tns-test case: send NS-ALIVE PDU */
gprs_ns_tx_alive(nsvc);
/* start Tns-alive timer (transition into faster
* alive retransmissions) */
nsvc->alive_retries = 0;
nsvc_start_timer(nsvc, NSVC_TIMER_TNS_ALIVE);
break;
case NSVC_TIMER_TNS_RESET:
/* Chapter 7.3: Re-send the RESET */
gprs_ns_tx_reset(nsvc, NS_CAUSE_OM_INTERVENTION);
/* Re-start Tns-reset timer */
nsvc_start_timer(nsvc, NSVC_TIMER_TNS_RESET);
break;
case _NSVC_TIMER_NR:
break;
}
}
/* Section 9.2.6 */
static int gprs_ns_tx_reset_ack(struct gprs_nsvc *nsvc)
{
struct msgb *msg = gprs_ns_msgb_alloc();
struct gprs_ns_hdr *nsh;
uint16_t nsvci, nsei;
log_set_context(GPRS_CTX_NSVC, nsvc);
if (!msg)
return -ENOMEM;
nsvci = htons(nsvc->nsvci);
nsei = htons(nsvc->nsei);
msg->l2h = msgb_put(msg, sizeof(*nsh));
nsh = (struct gprs_ns_hdr *) msg->l2h;
nsh->pdu_type = NS_PDUT_RESET_ACK;
LOGP(DNS, LOGL_INFO, "NSEI=%u Tx NS RESET ACK (NSVCI=%u)\n",
nsvc->nsei, nsvc->nsvci);
msgb_tvlv_put(msg, NS_IE_VCI, 2, (uint8_t *)&nsvci);
msgb_tvlv_put(msg, NS_IE_NSEI, 2, (uint8_t *)&nsei);
return gprs_ns_tx(nsvc, msg);
}
/*! \brief High-level function for transmitting a NS-UNITDATA messsage
* \param[in] nsi NS-instance on which we shall transmit
* \param[in] msg struct msgb to be trasnmitted
*
* This function obtains the NS-VC by the msgb_nsei(msg) and then checks
* if the NS-VC is ALIVEV and not BLOCKED. After that, it adds a NS
* header for the NS-UNITDATA message type and sends it off.
*
* Section 9.2.10: transmit side / NS-UNITDATA-REQUEST primitive
*/
int gprs_ns_sendmsg(struct gprs_ns_inst *nsi, struct msgb *msg)
{
struct gprs_nsvc *nsvc;
struct gprs_ns_hdr *nsh;
uint16_t bvci = msgb_bvci(msg);
nsvc = gprs_nsvc_by_nsei(nsi, msgb_nsei(msg));
if (!nsvc) {
LOGP(DNS, LOGL_ERROR, "Unable to resolve NSEI %u "
"to NS-VC!\n", msgb_nsei(msg));
msgb_free(msg);
return -EINVAL;
}
log_set_context(GPRS_CTX_NSVC, nsvc);
if (!(nsvc->state & NSE_S_ALIVE)) {
LOGP(DNS, LOGL_ERROR, "NSEI=%u is not alive, cannot send\n",
nsvc->nsei);
msgb_free(msg);
return -EBUSY;
}
if (nsvc->state & NSE_S_BLOCKED) {
LOGP(DNS, LOGL_ERROR, "NSEI=%u is blocked, cannot send\n",
nsvc->nsei);
msgb_free(msg);
return -EBUSY;
}
msg->l2h = msgb_push(msg, sizeof(*nsh) + 3);
nsh = (struct gprs_ns_hdr *) msg->l2h;
if (!nsh) {
LOGP(DNS, LOGL_ERROR, "Not enough headroom for NS header\n");
msgb_free(msg);
return -EIO;
}
nsh->pdu_type = NS_PDUT_UNITDATA;
/* spare octet in data[0] */
nsh->data[1] = bvci >> 8;
nsh->data[2] = bvci & 0xff;
return gprs_ns_tx(nsvc, msg);
}
/* Section 9.2.10: receive side */
static int gprs_ns_rx_unitdata(struct gprs_nsvc *nsvc, struct msgb *msg)
{
struct gprs_ns_hdr *nsh = (struct gprs_ns_hdr *)msg->l2h;
uint16_t bvci;
if (nsvc->state & NSE_S_BLOCKED)
return gprs_ns_tx_status(nsvc, NS_CAUSE_NSVC_BLOCKED,
0, msg);
/* spare octet in data[0] */
bvci = nsh->data[1] << 8 | nsh->data[2];
msgb_bssgph(msg) = &nsh->data[3];
msgb_bvci(msg) = bvci;
/* call upper layer (BSSGP) */
return nsvc->nsi->cb(GPRS_NS_EVT_UNIT_DATA, nsvc, msg, bvci);
}
/* Section 9.2.7 */
static int gprs_ns_rx_status(struct gprs_nsvc *nsvc, struct msgb *msg)
{
struct gprs_ns_hdr *nsh = (struct gprs_ns_hdr *) msg->l2h;
struct tlv_parsed tp;
uint8_t cause;
int rc;
LOGP(DNS, LOGL_NOTICE, "NSEI=%u Rx NS STATUS ", nsvc->nsei);
rc = tlv_parse(&tp, &ns_att_tlvdef, nsh->data,
msgb_l2len(msg) - sizeof(*nsh), 0, 0);
if (rc < 0) {
LOGPC(DNS, LOGL_NOTICE, "Error during TLV Parse\n");
LOGP(DNS, LOGL_ERROR, "NSEI=%u Rx NS STATUS: "
"Error during TLV Parse\n", nsvc->nsei);
return rc;
}
if (!TLVP_PRESENT(&tp, NS_IE_CAUSE)) {
LOGPC(DNS, LOGL_INFO, "missing cause IE\n");
return -EINVAL;
}
cause = *TLVP_VAL(&tp, NS_IE_CAUSE);
LOGPC(DNS, LOGL_NOTICE, "cause=%s\n", gprs_ns_cause_str(cause));
return 0;
}
/* Section 7.3 */
static int gprs_ns_rx_reset(struct gprs_nsvc *nsvc, struct msgb *msg)
{
struct gprs_ns_hdr *nsh = (struct gprs_ns_hdr *) msg->l2h;
struct tlv_parsed tp;
uint8_t *cause;
uint16_t *nsvci, *nsei;
int rc;
rc = tlv_parse(&tp, &ns_att_tlvdef, nsh->data,
msgb_l2len(msg) - sizeof(*nsh), 0, 0);
if (rc < 0) {
LOGP(DNS, LOGL_ERROR, "NSEI=%u Rx NS RESET "
"Error during TLV Parse\n", nsvc->nsei);
return rc;
}
if (!TLVP_PRESENT(&tp, NS_IE_CAUSE) ||
!TLVP_PRESENT(&tp, NS_IE_VCI) ||
!TLVP_PRESENT(&tp, NS_IE_NSEI)) {
LOGP(DNS, LOGL_ERROR, "NS RESET Missing mandatory IE\n");
gprs_ns_tx_status(nsvc, NS_CAUSE_MISSING_ESSENT_IE, 0, msg);
return -EINVAL;
}
cause = (uint8_t *) TLVP_VAL(&tp, NS_IE_CAUSE);
nsvci = (uint16_t *) TLVP_VAL(&tp, NS_IE_VCI);
nsei = (uint16_t *) TLVP_VAL(&tp, NS_IE_NSEI);
LOGP(DNS, LOGL_INFO, "NSEI=%u Rx NS RESET (NSVCI=%u, cause=%s)\n",
nsvc->nsvci, nsvc->nsei, gprs_ns_cause_str(*cause));
/* Mark NS-VC as blocked and alive */
nsvc->state = NSE_S_BLOCKED | NSE_S_ALIVE;
nsvc->nsei = ntohs(*nsei);
nsvc->nsvci = ntohs(*nsvci);
/* start the test procedure */
gprs_ns_tx_simple(nsvc, NS_PDUT_ALIVE);
nsvc_start_timer(nsvc, NSVC_TIMER_TNS_TEST);
/* inform interested parties about the fact that this NSVC
* has received RESET */
ns_osmo_signal_dispatch(nsvc, S_NS_RESET, *cause);
return gprs_ns_tx_reset_ack(nsvc);
}
static int gprs_ns_rx_block(struct gprs_nsvc *nsvc, struct msgb *msg)
{
struct gprs_ns_hdr *nsh = (struct gprs_ns_hdr *) msg->l2h;
struct tlv_parsed tp;
uint8_t *cause;
int rc;
LOGP(DNS, LOGL_INFO, "NSEI=%u Rx NS BLOCK\n", nsvc->nsei);
nsvc->state |= NSE_S_BLOCKED;
rc = tlv_parse(&tp, &ns_att_tlvdef, nsh->data,
msgb_l2len(msg) - sizeof(*nsh), 0, 0);
if (rc < 0) {
LOGP(DNS, LOGL_ERROR, "NSEI=%u Rx NS BLOCK "
"Error during TLV Parse\n", nsvc->nsei);
return rc;
}
if (!TLVP_PRESENT(&tp, NS_IE_CAUSE) ||
!TLVP_PRESENT(&tp, NS_IE_VCI)) {
LOGP(DNS, LOGL_ERROR, "NS RESET Missing mandatory IE\n");
gprs_ns_tx_status(nsvc, NS_CAUSE_MISSING_ESSENT_IE, 0, msg);
return -EINVAL;
}
cause = (uint8_t *) TLVP_VAL(&tp, NS_IE_CAUSE);
//nsvci = (uint16_t *) TLVP_VAL(&tp, NS_IE_VCI);
ns_osmo_signal_dispatch(nsvc, S_NS_BLOCK, *cause);
rate_ctr_inc(&nsvc->ctrg->ctr[NS_CTR_BLOCKED]);
return gprs_ns_tx_simple(nsvc, NS_PDUT_BLOCK_ACK);
}
/*! \brief Receive incoming NS message from underlying transport layer
* \param nsi NS instance to which the data belongs
* \param[in] msg message buffer containing newly-received data
* \param[in] saddr socketaddr from which data was received
* \param[in] ll link-layer type in which data was received
* \returns 0 in case of success, < 0 in case of error
*
* This is the main entry point int othe NS imlementation where frames
* from the underlying transport (normally UDP) enter.
*/
int gprs_ns_rcvmsg(struct gprs_ns_inst *nsi, struct msgb *msg,
struct sockaddr_in *saddr, enum gprs_ns_ll ll)
{
struct gprs_ns_hdr *nsh = (struct gprs_ns_hdr *) msg->l2h;
struct gprs_nsvc *nsvc;
int rc = 0;
/* look up the NSVC based on source address */
nsvc = nsvc_by_rem_addr(nsi, saddr);
if (!nsvc) {
struct tlv_parsed tp;
uint16_t nsei;
if (nsh->pdu_type == NS_PDUT_STATUS) {
LOGP(DNS, LOGL_INFO, "Ignoring NS STATUS from %s:%u "
"for non-existing NS-VC\n",
inet_ntoa(saddr->sin_addr), ntohs(saddr->sin_port));
return 0;
}
/* Only the RESET procedure creates a new NSVC */
if (nsh->pdu_type != NS_PDUT_RESET) {
/* Since we have no NSVC, we have to use a fake */
nsvc = nsi->unknown_nsvc;
log_set_context(GPRS_CTX_NSVC, nsvc);
LOGP(DNS, LOGL_INFO, "Rejecting NS PDU type 0x%0x "
"from %s:%u for non-existing NS-VC\n",
nsh->pdu_type, inet_ntoa(saddr->sin_addr),
ntohs(saddr->sin_port));
nsvc->nsvci = nsvc->nsei = 0xfffe;
nsvc->ip.bts_addr = *saddr;
nsvc->state = NSE_S_ALIVE;
nsvc->ll = ll;
#if 0
return gprs_ns_tx_reset(nsvc, NS_CAUSE_PDU_INCOMP_PSTATE);
#else
return gprs_ns_tx_status(nsvc,
NS_CAUSE_PDU_INCOMP_PSTATE, 0,
msg);
#endif
}
rc = tlv_parse(&tp, &ns_att_tlvdef, nsh->data,
msgb_l2len(msg) - sizeof(*nsh), 0, 0);
if (rc < 0) {
LOGP(DNS, LOGL_ERROR, "Rx NS RESET Error %d during "
"TLV Parse\n", rc);
return rc;
}
if (!TLVP_PRESENT(&tp, NS_IE_CAUSE) ||
!TLVP_PRESENT(&tp, NS_IE_VCI) ||
!TLVP_PRESENT(&tp, NS_IE_NSEI)) {
LOGP(DNS, LOGL_ERROR, "NS RESET Missing mandatory IE\n");
gprs_ns_tx_status(nsvc, NS_CAUSE_MISSING_ESSENT_IE, 0,
msg);
return -EINVAL;
}
nsei = ntohs(*(uint16_t *)TLVP_VAL(&tp, NS_IE_NSEI));
/* Check if we already know this NSEI, the remote end might
* simply have changed addresses, or it is a SGSN */
nsvc = gprs_nsvc_by_nsei(nsi, nsei);
if (!nsvc) {
nsvc = gprs_nsvc_create(nsi, 0xffff);
nsvc->ll = ll;
log_set_context(GPRS_CTX_NSVC, nsvc);
LOGP(DNS, LOGL_INFO, "Creating NS-VC for BSS at %s:%u\n",
inet_ntoa(saddr->sin_addr), ntohs(saddr->sin_port));
}
/* Update the remote peer IP address/port */
nsvc->ip.bts_addr = *saddr;
} else
msgb_nsei(msg) = nsvc->nsei;
log_set_context(GPRS_CTX_NSVC, nsvc);
/* Increment number of Incoming bytes */
rate_ctr_inc(&nsvc->ctrg->ctr[NS_CTR_PKTS_IN]);
rate_ctr_add(&nsvc->ctrg->ctr[NS_CTR_BYTES_IN], msgb_l2len(msg));
switch (nsh->pdu_type) {
case NS_PDUT_ALIVE:
/* If we're dead and blocked and suddenly receive a
* NS-ALIVE out of the blue, we might have been re-started
* and should send a NS-RESET to make sure everything recovers
* fine. */
if (nsvc->state == NSE_S_BLOCKED)
rc = gprs_ns_tx_reset(nsvc, NS_CAUSE_PDU_INCOMP_PSTATE);
else
rc = gprs_ns_tx_alive_ack(nsvc);
break;
case NS_PDUT_ALIVE_ACK:
/* stop Tns-alive and start Tns-test */
nsvc_start_timer(nsvc, NSVC_TIMER_TNS_TEST);
if (nsvc->remote_end_is_sgsn) {
/* FIXME: this should be one level higher */
if (nsvc->state & NSE_S_BLOCKED)
rc = gprs_ns_tx_unblock(nsvc);
}
break;
case NS_PDUT_UNITDATA:
/* actual user data */
rc = gprs_ns_rx_unitdata(nsvc, msg);
break;
case NS_PDUT_STATUS:
rc = gprs_ns_rx_status(nsvc, msg);
break;
case NS_PDUT_RESET:
rc = gprs_ns_rx_reset(nsvc, msg);
break;
case NS_PDUT_RESET_ACK:
LOGP(DNS, LOGL_INFO, "NSEI=%u Rx NS RESET ACK\n", nsvc->nsei);
/* mark NS-VC as blocked + active */
nsvc->state = NSE_S_BLOCKED | NSE_S_ALIVE;
nsvc->remote_state = NSE_S_BLOCKED | NSE_S_ALIVE;
rate_ctr_inc(&nsvc->ctrg->ctr[NS_CTR_BLOCKED]);
if (nsvc->persistent || nsvc->remote_end_is_sgsn) {
/* stop RESET timer */
osmo_timer_del(&nsvc->timer);
}
/* Initiate TEST proc.: Send ALIVE and start timer */
rc = gprs_ns_tx_simple(nsvc, NS_PDUT_ALIVE);
nsvc_start_timer(nsvc, NSVC_TIMER_TNS_TEST);
break;
case NS_PDUT_UNBLOCK:
/* Section 7.2: unblocking procedure */
LOGP(DNS, LOGL_INFO, "NSEI=%u Rx NS UNBLOCK\n", nsvc->nsei);
nsvc->state &= ~NSE_S_BLOCKED;
ns_osmo_signal_dispatch(nsvc, S_NS_UNBLOCK, 0);
rc = gprs_ns_tx_simple(nsvc, NS_PDUT_UNBLOCK_ACK);
break;
case NS_PDUT_UNBLOCK_ACK:
LOGP(DNS, LOGL_INFO, "NSEI=%u Rx NS UNBLOCK ACK\n", nsvc->nsei);
/* mark NS-VC as unblocked + active */
nsvc->state = NSE_S_ALIVE;
nsvc->remote_state = NSE_S_ALIVE;
ns_osmo_signal_dispatch(nsvc, S_NS_UNBLOCK, 0);
break;
case NS_PDUT_BLOCK:
rc = gprs_ns_rx_block(nsvc, msg);
break;
case NS_PDUT_BLOCK_ACK:
LOGP(DNS, LOGL_INFO, "NSEI=%u Rx NS BLOCK ACK\n", nsvc->nsei);
/* mark remote NS-VC as blocked + active */
nsvc->remote_state = NSE_S_BLOCKED | NSE_S_ALIVE;
break;
default:
LOGP(DNS, LOGL_NOTICE, "NSEI=%u Rx Unknown NS PDU type 0x%02x\n",
nsvc->nsei, nsh->pdu_type);
rc = -EINVAL;
break;
}
return rc;
}
/*! \brief Create a new GPRS NS instance
* \param[in] cb Call-back function for incoming BSSGP data
* \returns dynamically allocated gprs_ns_inst
*/
struct gprs_ns_inst *gprs_ns_instantiate(gprs_ns_cb_t *cb, void *ctx)
{
struct gprs_ns_inst *nsi = talloc_zero(ctx, struct gprs_ns_inst);
nsi->cb = cb;
INIT_LLIST_HEAD(&nsi->gprs_nsvcs);
nsi->timeout[NS_TOUT_TNS_BLOCK] = 3;
nsi->timeout[NS_TOUT_TNS_BLOCK_RETRIES] = 3;
nsi->timeout[NS_TOUT_TNS_RESET] = 3;
nsi->timeout[NS_TOUT_TNS_RESET_RETRIES] = 3;
nsi->timeout[NS_TOUT_TNS_TEST] = 30;
nsi->timeout[NS_TOUT_TNS_ALIVE] = 3;
nsi->timeout[NS_TOUT_TNS_ALIVE_RETRIES] = 10;
/* Create the dummy NSVC that we use for sending
* messages to non-existant/unknown NS-VC's */
nsi->unknown_nsvc = gprs_nsvc_create(nsi, 0xfffe);
llist_del(&nsi->unknown_nsvc->list);
return nsi;
}
/*! \brief Destroy an entire NS instance
* \param nsi gprs_ns_inst that is to be destroyed
*
* This function SHOULD release all resources associated with the
* NS-instance but is actually not completely implemented!
*/
void gprs_ns_destroy(struct gprs_ns_inst *nsi)
{
/* FIXME: clear all timers */
/* recursively free the NSI and all its NSVCs */
talloc_free(nsi);
}
/* NS-over-IP code, according to 3GPP TS 48.016 Chapter 6.2
* We don't support Size Procedure, Configuration Procedure, ChangeWeight Procedure */
/* Read a single NS-over-IP message */
static struct msgb *read_nsip_msg(struct osmo_fd *bfd, int *error,
struct sockaddr_in *saddr)
{
struct msgb *msg = gprs_ns_msgb_alloc();
int ret = 0;
socklen_t saddr_len = sizeof(*saddr);
if (!msg) {
*error = -ENOMEM;
return NULL;
}
ret = recvfrom(bfd->fd, msg->data, NS_ALLOC_SIZE - NS_ALLOC_HEADROOM, 0,
(struct sockaddr *)saddr, &saddr_len);
if (ret < 0) {
LOGP(DNS, LOGL_ERROR, "recv error %s during NSIP recv\n",
strerror(errno));
msgb_free(msg);
*error = ret;
return NULL;
} else if (ret == 0) {
msgb_free(msg);
*error = ret;
return NULL;
}
msg->l2h = msg->data;
msgb_put(msg, ret);
return msg;
}
static int handle_nsip_read(struct osmo_fd *bfd)
{
int error;
struct sockaddr_in saddr;
struct gprs_ns_inst *nsi = bfd->data;
struct msgb *msg = read_nsip_msg(bfd, &error, &saddr);
if (!msg)
return error;
error = gprs_ns_rcvmsg(nsi, msg, &saddr, GPRS_NS_LL_UDP);
msgb_free(msg);
return error;
}
static int handle_nsip_write(struct osmo_fd *bfd)
{
/* FIXME: actually send the data here instead of nsip_sendmsg() */
return -EIO;
}
static int nsip_sendmsg(struct gprs_nsvc *nsvc, struct msgb *msg)
{
int rc;
struct gprs_ns_inst *nsi = nsvc->nsi;
struct sockaddr_in *daddr = &nsvc->ip.bts_addr;
rc = sendto(nsi->nsip.fd.fd, msg->data, msg->len, 0,
(struct sockaddr *)daddr, sizeof(*daddr));
msgb_free(msg);
return rc;
}
/* UDP Port 23000 carries the LLC-in-BSSGP-in-NS protocol stack */
static int nsip_fd_cb(struct osmo_fd *bfd, unsigned int what)
{
int rc = 0;
if (what & BSC_FD_READ)
rc = handle_nsip_read(bfd);
if (what & BSC_FD_WRITE)
rc = handle_nsip_write(bfd);
return rc;
}
/*! \brief Create a listening socket for GPRS NS/UDP/IP
* \param[in] nsi NS protocol instance to listen
* \returns >=0 (fd) in case of success, negative in case of error
*
* A call to this function will create a UDP socket bound to the port
* number and IP address specified in the NS protocol instance. The
* file descriptor of the socket will be stored in nsi->nsip.fd.
*/
int gprs_ns_nsip_listen(struct gprs_ns_inst *nsi)
{
struct in_addr in;
int ret;
in.s_addr = htonl(nsi->nsip.local_ip);
nsi->nsip.fd.cb = nsip_fd_cb;
nsi->nsip.fd.data = nsi;
ret = osmo_sock_init_ofd(&nsi->nsip.fd, AF_INET, SOCK_DGRAM,
IPPROTO_UDP, inet_ntoa(in),
nsi->nsip.local_port, OSMO_SOCK_F_BIND);
if (ret < 0)
return ret;
return ret;
}
/*! \brief Initiate a RESET procedure
* \param[in] nsvc NS-VC in which to start the procedure
* \param[in] cause Numeric NS cause value
*
* This is a high-level function initiating a NS-RESET procedure. It
* will not only send a NS-RESET, but also set the state to BLOCKED and
* start the Tns-reset timer.
*/
void gprs_nsvc_reset(struct gprs_nsvc *nsvc, uint8_t cause)
{
LOGP(DNS, LOGL_INFO, "NSEI=%u RESET procedure based on API request\n",
nsvc->nsei);
/* Mark NS-VC locally as blocked and dead */
nsvc->state = NSE_S_BLOCKED;
/* Send NS-RESET PDU */
if (gprs_ns_tx_reset(nsvc, cause) < 0) {
LOGP(DNS, LOGL_ERROR, "NSEI=%u, error resetting NS-VC\n",
nsvc->nsei);
}
/* Start Tns-reset */
nsvc_start_timer(nsvc, NSVC_TIMER_TNS_RESET);
}
/*! \brief Establish a NS connection (from the BSS) to the SGSN
* \param nsi NS-instance
* \param[in] dest Destination IP/Port
* \param[in] nsei NSEI of the to-be-established NS-VC
* \param[in] nsvci NSVCI of the to-be-established NS-VC
* \returns struct gprs_nsvc representing the new NS-VC
*
* This function will establish a single NS/UDP/IP connection in uplink
* (BSS to SGSN) direction.
*/
struct gprs_nsvc *gprs_ns_nsip_connect(struct gprs_ns_inst *nsi,
struct sockaddr_in *dest, uint16_t nsei,
uint16_t nsvci)
{
struct gprs_nsvc *nsvc;
nsvc = nsvc_by_rem_addr(nsi, dest);
if (!nsvc)
nsvc = gprs_nsvc_create(nsi, nsvci);
nsvc->ip.bts_addr = *dest;
nsvc->nsei = nsei;
nsvc->nsvci = nsvci;
nsvc->remote_end_is_sgsn = 1;
gprs_nsvc_reset(nsvc, NS_CAUSE_OM_INTERVENTION);
return nsvc;
}
void gprs_ns_set_log_ss(int ss)
{
DNS = ss;
}
/*! }@ */