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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 <sys/types.h>
#include <sys/socket.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,
NS_CTR_REPLACED,
NS_CTR_NSEI_CHG,
NS_CTR_INV_VCI,
NS_CTR_INV_NSEI,
};
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 " },
{ "replaced", "NS-VC replaced other count" },
{ "nsei-chg", "NS-VC changed NSEI count " },
{ "inv-nsvci", "NS-VCI was invalid count " },
{ "inv-nsei", "NSEI was invalid 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,
};
#define CHECK_TX_RC(rc, nsvc) \
if (rc < 0) \
LOGP(DNS, LOGL_ERROR, "TX failed (%d) to peer %s\n", \
rc, gprs_ns_ll_str(nsvc));
/*! \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 first 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;
}
static struct gprs_nsvc *gprs_active_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) {
if (!(nsvc->state & NSE_S_BLOCKED) &&
nsvc->state & NSE_S_ALIVE)
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;
nsvc->nsvci_is_valid = 1;
/* 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);
rate_ctr_group_free(nsvc->ctrg);
talloc_free(nsvc);
}
static void ns_osmo_signal_dispatch(struct gprs_nsvc *nsvc, unsigned int signal,
uint8_t cause)
{
struct ns_signal_data nssd = {0};
nssd.nsvc = nsvc;
nssd.cause = cause;
osmo_signal_dispatch(SS_L_NS, signal, &nssd);
}
static void ns_osmo_signal_dispatch_mismatch(struct gprs_nsvc *nsvc,
struct msgb *msg,
uint8_t pdu_type, uint8_t ie_type)
{
struct ns_signal_data nssd = {0};
nssd.nsvc = nsvc;
nssd.pdu_type = pdu_type;
nssd.ie_type = ie_type;
nssd.msg = msg;
osmo_signal_dispatch(SS_L_NS, S_NS_MISMATCH, &nssd);
}
static void ns_osmo_signal_dispatch_replaced(struct gprs_nsvc *nsvc, struct gprs_nsvc *old_nsvc)
{
struct ns_signal_data nssd = {0};
nssd.nsvc = nsvc;
nssd.old_nsvc = old_nsvc;
osmo_signal_dispatch(SS_L_NS, S_NS_REPLACED, &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_active_nsvc_by_nsei(nsi, msgb_nsei(msg));
if (!nsvc) {
int rc;
if (gprs_nsvc_by_nsei(nsi, msgb_nsei(msg))) {
LOGP(DNS, LOGL_ERROR,
"All NS-VCs for NSEI %u are either dead or blocked!\n",
msgb_nsei(msg));
rc = -EBUSY;
} else {
LOGP(DNS, LOGL_ERROR, "Unable to resolve NSEI %u "
"to NS-VC!\n", msgb_nsei(msg));
rc = -EINVAL;
}
msgb_free(msg);
return rc;
}
log_set_context(GPRS_CTX_NSVC, nsvc);
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;
}
/* Replace a nsvc object with another based on NSVCI.
* This function replaces looks for a NSVC with the given NSVCI and replaces it
* if possible and necessary. If replaced, the former value of *nsvc is
* returned in *old_nsvc.
* \return != 0 if *nsvc points to a matching NSVC.
*/
static int gprs_nsvc_replace_if_found(uint16_t nsvci,
struct gprs_nsvc **nsvc,
struct gprs_nsvc **old_nsvc)
{
struct gprs_nsvc *matching_nsvc;
if ((*nsvc)->nsvci == nsvci) {
*old_nsvc = NULL;
return 1;
}
matching_nsvc = gprs_nsvc_by_nsvci((*nsvc)->nsi, nsvci);
if (!matching_nsvc)
return 0;
/* The NS-VCI is already used by this NS-VC */
char *old_peer;
/* Exchange the NS-VC objects */
*old_nsvc = *nsvc;
*nsvc = matching_nsvc;
/* Do logging */
old_peer = talloc_strdup(*old_nsvc, gprs_ns_ll_str(*old_nsvc));
LOGP(DNS, LOGL_INFO, "NS-VC changed link (NSVCI=%u) from %s to %s\n",
nsvci, old_peer, gprs_ns_ll_str(*nsvc));
talloc_free(old_peer);
return 1;
}
/* 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;
struct gprs_nsvc *orig_nsvc = NULL;
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 = ntohs(*(uint16_t *) TLVP_VAL(&tp, NS_IE_VCI));
nsei = ntohs(*(uint16_t *) TLVP_VAL(&tp, NS_IE_NSEI));
LOGP(DNS, LOGL_INFO, "NSVCI=%u%s Rx NS RESET (NSEI=%u, NSVCI=%u, cause=%s)\n",
(*nsvc)->nsvci, (*nsvc)->nsvci_is_valid ? "" : "(invalid)",
nsei, nsvci, gprs_ns_cause_str(cause));
if ((*nsvc)->nsvci_is_valid && (*nsvc)->nsvci != nsvci) {
if ((*nsvc)->persistent || (*nsvc)->remote_end_is_sgsn) {
/* The incoming RESET doesn't match the NSVCI. Send an
* appropriate RESET_ACK and ignore the RESET.
* See 3GPP TS 08.16, 7.3.1, 2nd paragraph.
*/
ns_osmo_signal_dispatch_mismatch(*nsvc, msg,
NS_PDUT_RESET,
NS_IE_VCI);
rate_ctr_inc(&(*nsvc)->ctrg->ctr[NS_CTR_INV_VCI]);
gprs_ns_tx_reset_ack(*nsvc);
return 0;
}
/* NS-VCI has changed */
if (!gprs_nsvc_replace_if_found(nsvci, nsvc, &orig_nsvc)) {
LOGP(DNS, LOGL_INFO, "Creating NS-VC %d replacing %d "
"at %s\n",
nsvci, (*nsvc)->nsvci,
gprs_ns_ll_str(*nsvc));
orig_nsvc = *nsvc;
*nsvc = gprs_nsvc_create((*nsvc)->nsi, nsvci);
(*nsvc)->nsei = nsei;
}
}
if ((*nsvc)->nsvci_is_valid && (*nsvc)->nsei != nsei) {
if ((*nsvc)->persistent || (*nsvc)->remote_end_is_sgsn) {
/* The incoming RESET doesn't match the NSEI. Send an
* appropriate RESET_ACK and ignore the RESET.
* See 3GPP TS 08.16, 7.3.1, 3rd paragraph.
*/
ns_osmo_signal_dispatch_mismatch(*nsvc, msg,
NS_PDUT_RESET,
NS_IE_NSEI);
rate_ctr_inc(&(*nsvc)->ctrg->ctr[NS_CTR_INV_NSEI]);
rc = gprs_ns_tx_reset_ack(*nsvc);
CHECK_TX_RC(rc, *nsvc);
return 0;
}
/* NSEI has changed */
rate_ctr_inc(&(*nsvc)->ctrg->ctr[NS_CTR_NSEI_CHG]);
(*nsvc)->nsei = nsei;
}
/* Mark NS-VC as blocked and alive */
(*nsvc)->state = NSE_S_BLOCKED | NSE_S_ALIVE;
if (orig_nsvc) {
rate_ctr_inc(&(*nsvc)->ctrg->ctr[NS_CTR_REPLACED]);
ns_osmo_signal_dispatch_replaced(*nsvc, orig_nsvc);
/* Update the ll info fields */
gprs_ns_ll_copy(*nsvc, orig_nsvc);
gprs_ns_ll_clear(orig_nsvc);
} else {
(*nsvc)->nsei = nsei;
(*nsvc)->nsvci = nsvci;
(*nsvc)->nsvci_is_valid = 1;
}
/* inform interested parties about the fact that this NSVC
* has received RESET */
ns_osmo_signal_dispatch(*nsvc, S_NS_RESET, cause);
rc = gprs_ns_tx_reset_ack(*nsvc);
/* start the test procedure */
gprs_ns_tx_simple((*nsvc), NS_PDUT_ALIVE);
nsvc_start_timer((*nsvc), NSVC_TIMER_TNS_TEST);
return rc;
}
static int gprs_ns_rx_reset_ack(struct gprs_nsvc **nsvc, struct msgb *msg)
{
struct gprs_ns_hdr *nsh = (struct gprs_ns_hdr *) msg->l2h;
struct tlv_parsed tp;
uint16_t nsvci, nsei;
struct gprs_nsvc *orig_nsvc = NULL;
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 ACK "
"Error during TLV Parse\n", (*nsvc)->nsei);
return rc;
}
if (!TLVP_PRESENT(&tp, NS_IE_VCI) ||
!TLVP_PRESENT(&tp, NS_IE_NSEI)) {
LOGP(DNS, LOGL_ERROR, "NS RESET ACK Missing mandatory IE\n");
rc = gprs_ns_tx_status(*nsvc, NS_CAUSE_MISSING_ESSENT_IE, 0, msg);
CHECK_TX_RC(rc, *nsvc);
return -EINVAL;
}
nsvci = ntohs(*(uint16_t *) TLVP_VAL(&tp, NS_IE_VCI));
nsei = ntohs(*(uint16_t *) TLVP_VAL(&tp, NS_IE_NSEI));
LOGP(DNS, LOGL_INFO, "NSVCI=%u%s Rx NS RESET ACK (NSEI=%u, NSVCI=%u)\n",
(*nsvc)->nsvci, (*nsvc)->nsvci_is_valid ? "" : "(invalid)",
nsei, nsvci);
if (!((*nsvc)->state & NSE_S_RESET)) {
/* Not waiting for a RESET_ACK on this NS-VC, ignore it.
* See 3GPP TS 08.16, 7.3.1, 5th paragraph.
*/
LOGP(DNS, LOGL_ERROR,
"NS RESET ACK Discarding unexpected message for "
"NS-VCI %d from SGSN NSEI=%d\n",
nsvci, nsei);
return 0;
}
if (!(*nsvc)->nsvci_is_valid) {
LOGP(DNS, LOGL_NOTICE,
"NS RESET ACK Uninitialised NS-VC (%u) for "
"NS-VCI %d, NSEI=%d from %s\n",
(*nsvc)->nsvci, nsvci, nsei, gprs_ns_ll_str(*nsvc));
return -EINVAL;
}
if ((*nsvc)->nsvci != nsvci) {
/* NS-VCI has changed */
/* if !0, use another NSVC object that matches the NSVCI */
int use_other_nsvc;
/* Only do this with BSS peers */
use_other_nsvc = !(*nsvc)->remote_end_is_sgsn &&
!(*nsvc)->persistent;
if (use_other_nsvc)
/* Update *nsvc to point to the right NSVC object */
use_other_nsvc = gprs_nsvc_replace_if_found(nsvci, nsvc,
&orig_nsvc);
if (!use_other_nsvc) {
/* The incoming RESET_ACK doesn't match the NSVCI.
* See 3GPP TS 08.16, 7.3.1, 4th paragraph.
*/
ns_osmo_signal_dispatch_mismatch(*nsvc, msg,
NS_PDUT_RESET_ACK,
NS_IE_VCI);
rate_ctr_inc(&(*nsvc)->ctrg->ctr[NS_CTR_INV_VCI]);
LOGP(DNS, LOGL_ERROR,
"NS RESET ACK Unknown NS-VCI %d (%s NSEI=%d) "
"from %s\n",
nsvci,
(*nsvc)->remote_end_is_sgsn ? "SGSN" : "BSS",
nsei, gprs_ns_ll_str(*nsvc));
return -EINVAL;
}
/* Notify others */
rate_ctr_inc(&(*nsvc)->ctrg->ctr[NS_CTR_REPLACED]);
ns_osmo_signal_dispatch_replaced(*nsvc, orig_nsvc);
/* Update the ll info fields */
gprs_ns_ll_copy(*nsvc, orig_nsvc);
gprs_ns_ll_clear(orig_nsvc);
} else if ((*nsvc)->nsei != nsei) {
if ((*nsvc)->persistent || (*nsvc)->remote_end_is_sgsn) {
/* The incoming RESET_ACK doesn't match the NSEI.
* See 3GPP TS 08.16, 7.3.1, 4th paragraph.
*/
ns_osmo_signal_dispatch_mismatch(*nsvc, msg,
NS_PDUT_RESET_ACK,
NS_IE_NSEI);
rate_ctr_inc(&(*nsvc)->ctrg->ctr[NS_CTR_INV_NSEI]);
LOGP(DNS, LOGL_ERROR,
"NS RESET ACK Unknown NSEI %d (NS-VCI=%u) from %s\n",
nsei, nsvci, gprs_ns_ll_str(*nsvc));
return -EINVAL;
}
/* NSEI has changed */
rate_ctr_inc(&(*nsvc)->ctrg->ctr[NS_CTR_NSEI_CHG]);
(*nsvc)->nsei = nsei;
}
/* Mark NS-VC as blocked and alive */
(*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);
return rc;
}
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);
}
int gprs_ns_vc_create(struct gprs_ns_inst *nsi, struct msgb *msg,
struct gprs_nsvc *fallback_nsvc,
struct gprs_nsvc **new_nsvc);
int gprs_ns_process_msg(struct gprs_ns_inst *nsi, struct msgb *msg,
struct gprs_nsvc **nsvc);
/*! \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_nsvc *nsvc;
int rc = 0;
/* look up the NSVC based on source address */
nsvc = nsvc_by_rem_addr(nsi, saddr);
if (!nsvc) {
struct gprs_nsvc *fallback_nsvc;
fallback_nsvc = nsi->unknown_nsvc;
log_set_context(GPRS_CTX_NSVC, fallback_nsvc);
fallback_nsvc->ip.bts_addr = *saddr;
fallback_nsvc->ll = ll;
rc = gprs_ns_vc_create(nsi, msg, fallback_nsvc, &nsvc);
if (rc < 0)
return rc;
rc = 0;
}
if (nsvc)
rc = gprs_ns_process_msg(nsi, msg, &nsvc);
return rc;
}
const char *gprs_ns_ll_str(struct gprs_nsvc *nsvc)
{
static char buf[80];
snprintf(buf, sizeof(buf), "%s:%u",
inet_ntoa(nsvc->ip.bts_addr.sin_addr),
ntohs(nsvc->ip.bts_addr.sin_port));
buf[sizeof(buf) - 1] = '\0';
return buf;
}
void gprs_ns_ll_copy(struct gprs_nsvc *nsvc, struct gprs_nsvc *other)
{
nsvc->ll = other->ll;
switch (nsvc->ll) {
case GPRS_NS_LL_UDP:
nsvc->ip = other->ip;
break;
case GPRS_NS_LL_FR_GRE:
nsvc->frgre = other->frgre;
break;
default:
break;
}
}
void gprs_ns_ll_clear(struct gprs_nsvc *nsvc)
{
switch (nsvc->ll) {
case GPRS_NS_LL_UDP:
nsvc->ip.bts_addr.sin_addr.s_addr = INADDR_ANY;
nsvc->ip.bts_addr.sin_port = 0;
break;
case GPRS_NS_LL_FR_GRE:
nsvc->frgre.bts_addr.sin_addr.s_addr = INADDR_ANY;
nsvc->frgre.bts_addr.sin_port = 0;
break;
default:
break;
}
}
/*! \brief Create/get NS-VC independently from underlying transport layer
* \param nsi NS instance to which the data belongs
* \param[in] msg message buffer containing newly-received data
* \param[in] fallback_nsvc is used to send error messages back to the peer
* and to initialise the ll info of a created NS-VC object
* \param[out] new_nsvc contains a pointer to a NS-VC object if one has
* been created or found
* \returns < 0 in case of error, GPRS_NS_CS_SKIPPED if a message has been
* skipped, GPRS_NS_CS_REJECTED if a message has been rejected and
* answered accordingly, GPRS_NS_CS_CREATED if a new NS-VC object
* has been created and registered, and GPRS_NS_CS_FOUND if an
* existing NS-VC object has been found with the same NSEI.
*
* This contains the initial NS automaton state (NS-VC not yet attached).
*/
int gprs_ns_vc_create(struct gprs_ns_inst *nsi, struct msgb *msg,
struct gprs_nsvc *fallback_nsvc,
struct gprs_nsvc **new_nsvc)
{
struct gprs_ns_hdr *nsh = (struct gprs_ns_hdr *)msg->l2h;
struct gprs_nsvc *existing_nsvc;
struct tlv_parsed tp;
uint16_t nsvci;
uint16_t nsei;
int rc;
if (nsh->pdu_type == NS_PDUT_STATUS) {
/* Do not respond, see 3GPP TS 08.16, 7.5.1 */
LOGP(DNS, LOGL_INFO, "Ignoring NS STATUS from %s "
"for non-existing NS-VC\n",
gprs_ns_ll_str(fallback_nsvc));
return GPRS_NS_CS_SKIPPED;
}
if (nsh->pdu_type == NS_PDUT_ALIVE_ACK) {
/* Ignore this, see 3GPP TS 08.16, 7.4.1 */
LOGP(DNS, LOGL_INFO, "Ignoring NS ALIVE ACK from %s "
"for non-existing NS-VC\n",
gprs_ns_ll_str(fallback_nsvc));
return GPRS_NS_CS_SKIPPED;
}
if (nsh->pdu_type == NS_PDUT_RESET_ACK) {
/* Ignore this, see 3GPP TS 08.16, 7.3.1 */
LOGP(DNS, LOGL_INFO, "Ignoring NS RESET ACK from %s "
"for non-existing NS-VC\n",
gprs_ns_ll_str(fallback_nsvc));
return GPRS_NS_CS_SKIPPED;
}
/* 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 */
log_set_context(GPRS_CTX_NSVC, fallback_nsvc);
LOGP(DNS, LOGL_INFO, "Rejecting NS PDU type 0x%0x "
"from %s for non-existing NS-VC\n",
nsh->pdu_type, gprs_ns_ll_str(fallback_nsvc));
fallback_nsvc->nsvci = fallback_nsvc->nsei = 0xfffe;
fallback_nsvc->nsvci_is_valid = 0;
fallback_nsvc->state = NSE_S_ALIVE;
rc = gprs_ns_tx_status(fallback_nsvc,
NS_CAUSE_PDU_INCOMP_PSTATE, 0, msg);
if (rc < 0) {
LOGP(DNS, LOGL_ERROR, "TX failed (%d) to peer %s\n",
rc, gprs_ns_ll_str(fallback_nsvc));
return rc;
}
return GPRS_NS_CS_REJECTED;
}
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");
rc = gprs_ns_tx_status(fallback_nsvc, NS_CAUSE_MISSING_ESSENT_IE, 0,
msg);
CHECK_TX_RC(rc, fallback_nsvc);
return -EINVAL;
}
nsvci = ntohs(*(uint16_t *) TLVP_VAL(&tp, NS_IE_VCI));
nsei = ntohs(*(uint16_t *) TLVP_VAL(&tp, NS_IE_NSEI));
/* Check if we already know this NSVCI, the remote end might
* simply have changed addresses, or it is a SGSN */
existing_nsvc = gprs_nsvc_by_nsvci(nsi, nsvci);
if (!existing_nsvc) {
*new_nsvc = gprs_nsvc_create(nsi, 0xffff);
(*new_nsvc)->nsvci_is_valid = 0;
log_set_context(GPRS_CTX_NSVC, *new_nsvc);
gprs_ns_ll_copy(*new_nsvc, fallback_nsvc);
LOGP(DNS, LOGL_INFO, "Creating NS-VC for BSS at %s\n",
gprs_ns_ll_str(fallback_nsvc));
return GPRS_NS_CS_CREATED;
}
/* Check NSEI */
if (existing_nsvc->nsei != nsei) {
LOGP(DNS, LOGL_NOTICE,
"NS-VC changed NSEI (NSVCI=%u) from %u to %u\n",
nsvci, existing_nsvc->nsei, nsei);
/* Override old NSEI */
existing_nsvc->nsei = nsei;
/* Do statistics */
rate_ctr_inc(&existing_nsvc->ctrg->ctr[NS_CTR_NSEI_CHG]);
}
*new_nsvc = existing_nsvc;
gprs_ns_ll_copy(*new_nsvc, fallback_nsvc);
return GPRS_NS_CS_FOUND;
}
/*! \brief Process NS message independently from underlying transport layer
* \param nsi NS instance to which the data belongs
* \param[in] msg message buffer containing newly-received data
* \param[inout] nsvc refers to the virtual connection, may be modified when
* processing a NS_RESET
* \returns 0 in case of success, < 0 in case of error
*
* This contains the main NS automaton.
*/
int gprs_ns_process_msg(struct gprs_ns_inst *nsi, struct msgb *msg,
struct gprs_nsvc **nsvc)
{
struct gprs_ns_hdr *nsh = (struct gprs_ns_hdr *) msg->l2h;
int rc = 0;
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_nsvc_reset((*nsvc), NS_CAUSE_PDU_INCOMP_PSTATE);
else if (!((*nsvc)->state & NSE_S_RESET))
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:
rc = gprs_ns_rx_reset_ack(nsvc, msg);
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);
nsi->unknown_nsvc->nsvci_is_valid = 0;
llist_del(&nsi->unknown_nsvc->list);
INIT_LLIST_HEAD(&nsi->unknown_nsvc->list);
return nsi;
}
void gprs_ns_close(struct gprs_ns_inst *nsi)
{
struct gprs_nsvc *nsvc, *nsvc2;
gprs_nsvc_delete(nsi->unknown_nsvc);
/* delete all NSVCs and clear their timers */
llist_for_each_entry_safe(nsvc, nsvc2, &nsi->gprs_nsvcs, list)
gprs_nsvc_delete(nsvc);
/* close socket and unregister */
if (nsi->nsip.fd.data) {
close(nsi->nsip.fd.fd);
osmo_fd_unregister(&nsi->nsip.fd);
nsi->nsip.fd.data = NULL;
}
}
/*! \brief Destroy an entire NS instance
* \param nsi gprs_ns_inst that is to be destroyed
*
* This function releases all resources associated with the
* NS-instance.
*/
void gprs_ns_destroy(struct gprs_ns_inst *nsi)
{
gprs_ns_close(nsi);
/* free the NSI */
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;
ret = setsockopt(nsi->nsip.fd.fd, IPPROTO_IP, IP_TOS,
&nsi->nsip.dscp, sizeof(nsi->nsip.dscp));
if (ret < 0)
LOGP(DNS, LOGL_ERROR,
"Failed to set the DSCP to %d with ret(%d) errno(%d)\n",
nsi->nsip.dscp, ret, errno);
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.
*/
int gprs_nsvc_reset(struct gprs_nsvc *nsvc, uint8_t cause)
{
int rc;
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 | NSE_S_RESET;
/* Send NS-RESET PDU */
rc = gprs_ns_tx_reset(nsvc, cause);
if (rc < 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);
return rc;
}
/*! \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->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;
}
/*! }@ */
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