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Diffstat (limited to 'src/gb/gprs_ns.c')
-rw-r--r-- | src/gb/gprs_ns.c | 1103 |
1 files changed, 1103 insertions, 0 deletions
diff --git a/src/gb/gprs_ns.c b/src/gb/gprs_ns.c new file mode 100644 index 00000000..cdee8338 --- /dev/null +++ b/src/gb/gprs_ns.c @@ -0,0 +1,1103 @@ +/* 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; +} + +/*! }@ */ |