diff options
Diffstat (limited to 'openbsc/src')
| -rw-r--r-- | openbsc/src/gprs_bssgp.c | 397 | ||||
| -rw-r--r-- | openbsc/src/gprs_ns.c | 348 |
2 files changed, 745 insertions, 0 deletions
diff --git a/openbsc/src/gprs_bssgp.c b/openbsc/src/gprs_bssgp.c new file mode 100644 index 00000000..de57d25d --- /dev/null +++ b/openbsc/src/gprs_bssgp.c @@ -0,0 +1,397 @@ +/* GPRS BSSGP protocol implementation as per 3GPP TS 08.18 */ + +/* (C) 2009 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 General Public License as published by + * the Free Software Foundation; either version 2 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 General Public License for more details. + * + * You should have received a copy of the GNU General Public License along + * with this program; if not, write to the Free Software Foundation, Inc., + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + * + */ + +#include <errno.h> +#include <sys/types.h> + +#include <netinet/in.h> + +#include <osmocore/msgb.h> +#include <osmocore/tlv.h> +#include <openbsc/debug.h> +#include <openbsc/gsm_data.h> +#include <openbsc/gsm_04_08_gprs.h> +#include <openbsc/gprs_bssgp.h> +#include <openbsc/gprs_llc.h> +#include <openbsc/gprs_ns.h> + +/* global pointer to the gsm network data structure */ +/* FIXME: this must go! */ +extern struct gsm_network *bsc_gsmnet; + +/* Chapter 11.3.9 / Table 11.10: Cause coding */ +static const char *bssgp_cause_strings[] = { + [BSSGP_CAUSE_PROC_OVERLOAD] = "Processor overload", + [BSSGP_CAUSE_EQUIP_FAIL] = "Equipment Failure", + [BSSGP_CAUSE_TRASIT_NET_FAIL] = "Transit netowkr service failure", + [BSSGP_CAUSE_CAPA_GREATER_0KPBS]= "Transmission capacity modified", + [BSSGP_CAUSE_UNKNOWN_MS] = "Unknown MS", + [BSSGP_CAUSE_UNKNOWN_BVCI] = "Unknown BVCI", + [BSSGP_CAUSE_CELL_TRAF_CONG] = "Cell traffic congestion", + [BSSGP_CAUSE_SGSN_CONG] = "SGSN congestion", + [BSSGP_CAUSE_OML_INTERV] = "O&M intervention", + [BSSGP_CAUSE_BVCI_BLOCKED] = "BVCI blocked", + [BSSGP_CAUSE_PFC_CREATE_FAIL] = "PFC create failure", + [BSSGP_CAUSE_SEM_INCORR_PDU] = "Semantically incorrect PDU", + [BSSGP_CAUSE_INV_MAND_INF] = "Invalid mandatory information", + [BSSGP_CAUSE_MISSING_MAND_IE] = "Missing mandatory IE", + [BSSGP_CAUSE_MISSING_COND_IE] = "Missing conditional IE", + [BSSGP_CAUSE_UNEXP_COND_IE] = "Unexpected conditional IE", + [BSSGP_CAUSE_COND_IE_ERR] = "Conditional IE error", + [BSSGP_CAUSE_PDU_INCOMP_STATE] = "PDU incompatible with protocol state", + [BSSGP_CAUSE_PROTO_ERR_UNSPEC] = "Protocol error - unspecified", + [BSSGP_CAUSE_PDU_INCOMP_FEAT] = "PDU not compatible with feature set", +}; + +static const char *bssgp_cause_str(enum gprs_bssgp_cause cause) +{ + if (cause >= ARRAY_SIZE(bssgp_cause_strings)) + return "undefined"; + + if (bssgp_cause_strings[cause]) + return bssgp_cause_strings[cause]; + + return "undefined"; +} + +static inline int bssgp_tlv_parse(struct tlv_parsed *tp, u_int8_t *buf, int len) +{ + return tlv_parse(tp, &tvlv_att_def, buf, len, 0, 0); +} + +static inline struct msgb *bssgp_msgb_alloc(void) +{ + return msgb_alloc_headroom(4096, 128, "BSSGP"); +} + +/* Transmit a simple response such as BLOCK/UNBLOCK/RESET ACK/NACK */ +static int bssgp_tx_simple_bvci(u_int8_t pdu_type, u_int16_t bvci, u_int16_t ns_bvci) +{ + struct msgb *msg = bssgp_msgb_alloc(); + struct bssgp_normal_hdr *bgph = + (struct bssgp_normal_hdr *) msgb_put(msg, sizeof(*bgph)); + u_int16_t _bvci; + + bgph->pdu_type = pdu_type; + _bvci = htons(bvci); + msgb_tvlv_put(msg, BSSGP_IE_BVCI, 2, (u_int8_t *) &_bvci); + + return gprs_ns_sendmsg(NULL, ns_bvci, msg); +} + +/* Chapter 10.4.5: Flow Control BVC ACK */ +static int bssgp_tx_fc_bvc_ack(u_int8_t tag, u_int16_t ns_bvci) +{ + struct msgb *msg = bssgp_msgb_alloc(); + struct bssgp_normal_hdr *bgph = + (struct bssgp_normal_hdr *) msgb_put(msg, sizeof(*bgph)); + + bgph->pdu_type = BSSGP_PDUT_FLOW_CONTROL_BVC_ACK; + msgb_tvlv_put(msg, BSSGP_IE_TAG, 1, &tag); + + return gprs_ns_sendmsg(NULL, ns_bvci, msg); +} + +/* Chapter 10.4.14: Status */ +static int bssgp_tx_status(u_int8_t cause, u_int16_t *bvci, struct msgb *orig_msg) +{ + struct msgb *msg = bssgp_msgb_alloc(); + struct bssgp_normal_hdr *bgph = + (struct bssgp_normal_hdr *) msgb_put(msg, sizeof(*bgph)); + + DEBUGPC(DGPRS, "BSSGP: TX STATUS, cause=%s\n", bssgp_cause_str(cause)); + + bgph->pdu_type = BSSGP_PDUT_STATUS; + msgb_tvlv_put(msg, BSSGP_IE_CAUSE, 1, &cause); + if (bvci) { + u_int16_t _bvci = htons(*bvci); + msgb_tvlv_put(msg, BSSGP_IE_BVCI, 2, (u_int8_t *) &_bvci); + } + if (orig_msg) + msgb_tvlv_put(msg, BSSGP_IE_PDU_IN_ERROR, + msgb_l3len(orig_msg), orig_msg->l3h); + + return gprs_ns_sendmsg(NULL, 0, msg); +} + +/* Uplink unit-data */ +static int bssgp_rx_ul_ud(struct msgb *msg, u_int16_t bvci) +{ + struct bssgp_ud_hdr *budh = (struct bssgp_ud_hdr *) msg->l3h; + struct gsm_bts *bts; + int data_len = msgb_l3len(msg) - sizeof(*budh); + struct tlv_parsed tp; + int rc; + + DEBUGP(DGPRS, "BSSGP UL-UD\n"); + + msg->tlli = ntohl(budh->tlli); + rc = bssgp_tlv_parse(&tp, budh->data, data_len); + + /* Cell ID and LLC_PDU are the only mandatory IE */ + if (!TLVP_PRESENT(&tp, BSSGP_IE_CELL_ID) || + !TLVP_PRESENT(&tp, BSSGP_IE_LLC_PDU)) + return -EIO; + + /* Determine the BTS based on the Cell ID */ + bts = gsm48_bts_by_ra_id(bsc_gsmnet, + TLVP_VAL(&tp, BSSGP_IE_CELL_ID), + TLVP_LEN(&tp, BSSGP_IE_CELL_ID)); + if (bts) + msg->trx = bts->c0; + + msg->llch = TLVP_VAL(&tp, BSSGP_IE_LLC_PDU); + + return gprs_llc_rcvmsg(msg, &tp); +} + +static int bssgp_rx_suspend(struct msgb *msg, u_int16_t bvci) +{ + struct bssgp_normal_hdr *bgph = (struct bssgp_normal_hdr *) msg->l3h; + int data_len = msgb_l3len(msg) - sizeof(*bgph); + struct tlv_parsed tp; + int rc; + + DEBUGP(DGPRS, "BSSGP SUSPEND\n"); + + rc = bssgp_tlv_parse(&tp, bgph->data, data_len); + if (rc < 0) + return rc; + + if (!TLVP_PRESENT(&tp, BSSGP_IE_TLLI) || + !TLVP_PRESENT(&tp, BSSGP_IE_ROUTEING_AREA)) + return -EIO; + + /* SEND SUSPEND_ACK or SUSPEND_NACK */ + /* FIXME */ +} + +static int bssgp_rx_resume(struct msgb *msg, u_int16_t bvci) +{ + struct bssgp_normal_hdr *bgph = (struct bssgp_normal_hdr *) msg->l3h; + int data_len = msgb_l3len(msg) - sizeof(*bgph); + struct tlv_parsed tp; + int rc; + + DEBUGP(DGPRS, "BSSGP RESUME\n"); + + rc = bssgp_tlv_parse(&tp, bgph->data, data_len); + if (rc < 0) + return rc; + + if (!TLVP_PRESENT(&tp, BSSGP_IE_TLLI) || + !TLVP_PRESENT(&tp, BSSGP_IE_ROUTEING_AREA) || + !TLVP_PRESENT(&tp, BSSGP_IE_SUSPEND_REF_NR)) + return -EIO; + + /* SEND RESUME_ACK or RESUME_NACK */ + /* FIXME */ +} + +static int bssgp_rx_fc_bvc(struct msgb *msg, struct tlv_parsed *tp, + u_int16_t ns_bvci) +{ + + DEBUGP(DGPRS, "BSSGP FC BVC\n"); + + if (!TLVP_PRESENT(tp, BSSGP_IE_TAG) || + !TLVP_PRESENT(tp, BSSGP_IE_BVC_BUCKET_SIZE) || + !TLVP_PRESENT(tp, BSSGP_IE_BUCKET_LEAK_RATE) || + !TLVP_PRESENT(tp, BSSGP_IE_BMAX_DEFAULT_MS) || + !TLVP_PRESENT(tp, BSSGP_IE_R_DEFAULT_MS)) + return bssgp_tx_status(BSSGP_CAUSE_MISSING_MAND_IE, NULL, msg); + + /* Send FLOW_CONTROL_BVC_ACK */ + return bssgp_tx_fc_bvc_ack(*TLVP_VAL(tp, BSSGP_IE_TAG), ns_bvci); +} +/* We expect msg->l3h to point to the BSSGP header */ +int gprs_bssgp_rcvmsg(struct msgb *msg, u_int16_t ns_bvci) +{ + struct bssgp_normal_hdr *bgph = (struct bssgp_normal_hdr *) msg->l3h; + struct tlv_parsed tp; + u_int8_t pdu_type = bgph->pdu_type; + int data_len = msgb_l3len(msg) - sizeof(*bgph); + u_int16_t bvci; + int rc = 0; + + if (pdu_type != BSSGP_PDUT_UL_UNITDATA && + pdu_type != BSSGP_PDUT_DL_UNITDATA) + rc = bssgp_tlv_parse(&tp, bgph->data, data_len); + + switch (pdu_type) { + case BSSGP_PDUT_UL_UNITDATA: + /* some LLC data from the MS */ + rc = bssgp_rx_ul_ud(msg, ns_bvci); + break; + case BSSGP_PDUT_RA_CAPABILITY: + /* BSS requests RA capability or IMSI */ + DEBUGP(DGPRS, "BSSGP RA CAPABILITY UPDATE\n"); + /* FIXME: send RA_CAPA_UPDATE_ACK */ + break; + case BSSGP_PDUT_RADIO_STATUS: + DEBUGP(DGPRS, "BSSGP RADIO STATUS\n"); + /* BSS informs us of some exception */ + break; + case BSSGP_PDUT_SUSPEND: + /* MS wants to suspend */ + rc = bssgp_rx_suspend(msg, ns_bvci); + break; + case BSSGP_PDUT_RESUME: + /* MS wants to resume */ + rc = bssgp_rx_resume(msg, ns_bvci); + break; + case BSSGP_PDUT_FLUSH_LL: + /* BSS informs MS has moved to one cell to other cell */ + DEBUGP(DGPRS, "BSSGP FLUSH LL\n"); + /* Send FLUSH_LL_ACK */ + break; + case BSSGP_PDUT_LLC_DISCARD: + /* BSS informs that some LLC PDU's have been discarded */ + DEBUGP(DGPRS, "BSSGP LLC DISCARDED\n"); + break; + case BSSGP_PDUT_FLOW_CONTROL_BVC: + /* BSS informs us of available bandwidth in Gb interface */ + rc = bssgp_rx_fc_bvc(msg, &tp, ns_bvci); + break; + case BSSGP_PDUT_FLOW_CONTROL_MS: + /* BSS informs us of available bandwidth to one MS */ + DEBUGP(DGPRS, "BSSGP FC MS\n"); + /* Send FLOW_CONTROL_MS_ACK */ + break; + case BSSGP_PDUT_BVC_BLOCK: + /* BSS tells us that BVC shall be blocked */ + DEBUGP(DGPRS, "BSSGP BVC BLOCK "); + if (!TLVP_PRESENT(&tp, BSSGP_IE_BVCI) || + !TLVP_PRESENT(&tp, BSSGP_IE_CAUSE)) + goto err_mand_ie; + bvci = ntohs(*(u_int16_t *)TLVP_VAL(&tp, BSSGP_IE_BVCI)); + DEBUGPC(DGPRS, "BVCI=%u, cause=%s\n", bvci, + bssgp_cause_str(*TLVP_VAL(&tp, BSSGP_IE_CAUSE))); + rc = bssgp_tx_simple_bvci(BSSGP_PDUT_BVC_BLOCK_ACK, + bvci, ns_bvci); + break; + case BSSGP_PDUT_BVC_UNBLOCK: + /* BSS tells us that BVC shall be unblocked */ + DEBUGP(DGPRS, "BSSGP BVC UNBLOCK "); + if (!TLVP_PRESENT(&tp, BSSGP_IE_BVCI)) + goto err_mand_ie; + bvci = ntohs(*(u_int16_t *)TLVP_VAL(&tp, BSSGP_IE_BVCI)); + DEBUGPC(DGPRS, "BVCI=%u\n", bvci); + rc = bssgp_tx_simple_bvci(BSSGP_PDUT_BVC_UNBLOCK_ACK, + bvci, ns_bvci); + break; + case BSSGP_PDUT_BVC_RESET: + /* BSS tells us that BVC init is required */ + DEBUGP(DGPRS, "BSSGP BVC RESET "); + if (!TLVP_PRESENT(&tp, BSSGP_IE_BVCI) || + !TLVP_PRESENT(&tp, BSSGP_IE_CAUSE)) + goto err_mand_ie; + bvci = ntohs(*(u_int16_t *)TLVP_VAL(&tp, BSSGP_IE_BVCI)); + DEBUGPC(DGPRS, "BVCI=%u, cause=%s\n", bvci, + bssgp_cause_str(*TLVP_VAL(&tp, BSSGP_IE_CAUSE))); + rc = bssgp_tx_simple_bvci(BSSGP_PDUT_BVC_RESET_ACK, + bvci, ns_bvci); + break; + case BSSGP_PDUT_STATUS: + /* Some exception has occurred */ + case BSSGP_PDUT_DOWNLOAD_BSS_PFC: + case BSSGP_PDUT_CREATE_BSS_PFC_ACK: + case BSSGP_PDUT_CREATE_BSS_PFC_NACK: + case BSSGP_PDUT_MODIFY_BSS_PFC: + case BSSGP_PDUT_DELETE_BSS_PFC_ACK: + DEBUGP(DGPRS, "BSSGP PDU type 0x%02x not [yet] implemented\n", + pdu_type); + break; + /* those only exist in the SGSN -> BSS direction */ + case BSSGP_PDUT_DL_UNITDATA: + case BSSGP_PDUT_PAGING_PS: + case BSSGP_PDUT_PAGING_CS: + case BSSGP_PDUT_RA_CAPA_UPDATE_ACK: + case BSSGP_PDUT_SUSPEND_ACK: + case BSSGP_PDUT_SUSPEND_NACK: + case BSSGP_PDUT_RESUME_ACK: + case BSSGP_PDUT_RESUME_NACK: + case BSSGP_PDUT_FLUSH_LL_ACK: + case BSSGP_PDUT_FLOW_CONTROL_BVC_ACK: + case BSSGP_PDUT_FLOW_CONTROL_MS_ACK: + case BSSGP_PDUT_BVC_BLOCK_ACK: + case BSSGP_PDUT_BVC_UNBLOCK_ACK: + case BSSGP_PDUT_SGSN_INVOKE_TRACE: + DEBUGP(DGPRS, "BSSGP PDU type 0x%02x only exists in DL\n", + pdu_type); + rc = -EINVAL; + break; + default: + DEBUGP(DGPRS, "BSSGP PDU type 0x%02x unknown\n", pdu_type); + break; + } + + return rc; +err_mand_ie: + return bssgp_tx_status(BSSGP_CAUSE_MISSING_MAND_IE, NULL, msg); +} + +int gprs_bssgp_tx_dl_ud(struct msgb *msg) +{ + struct gsm_bts *bts; + struct bssgp_ud_hdr *budh; + u_int8_t llc_pdu_tlv_hdr_len = 2; + u_int8_t *llc_pdu_tlv, *qos_profile; + u_int16_t pdu_lifetime = 1000; /* centi-seconds */ + u_int8_t qos_profile_default[3] = { 0x00, 0x00, 0x21 }; + u_int16_t msg_len = msg->len; + + if (!msg->trx) { + DEBUGP(DGPRS, "Cannot transmit DL-UD without TRX assigned\n"); + return -EINVAL; + } + + bts = msg->trx->bts; + + if (msg->len > TVLV_MAX_ONEBYTE) + llc_pdu_tlv_hdr_len += 1; + + /* prepend the tag and length of the LLC-PDU TLV */ + llc_pdu_tlv = msgb_push(msg, llc_pdu_tlv_hdr_len); + llc_pdu_tlv[0] = BSSGP_IE_LLC_PDU; + if (llc_pdu_tlv_hdr_len > 2) { + llc_pdu_tlv[1] = msg_len >> 8; + llc_pdu_tlv[2] = msg_len & 0xff; + } else { + llc_pdu_tlv[1] = msg_len & 0x3f; + llc_pdu_tlv[1] |= 0x80; + } + + /* FIXME: optional elements */ + + /* prepend the pdu lifetime */ + pdu_lifetime = htons(pdu_lifetime); + msgb_tvlv_push(msg, BSSGP_IE_PDU_LIFETIME, 2, (u_int8_t *)&pdu_lifetime); + + /* prepend the QoS profile, TLLI and pdu type */ + budh = (struct bssgp_ud_hdr *) msgb_push(msg, sizeof(*budh)); + memcpy(budh->qos_profile, qos_profile_default, sizeof(qos_profile_default)); + budh->tlli = htonl(msg->tlli); + budh->pdu_type = BSSGP_PDUT_DL_UNITDATA; + + return gprs_ns_sendmsg(NULL, bts->gprs.cell.bvci, msg); +} diff --git a/openbsc/src/gprs_ns.c b/openbsc/src/gprs_ns.c new file mode 100644 index 00000000..a686a22a --- /dev/null +++ b/openbsc/src/gprs_ns.c @@ -0,0 +1,348 @@ +/* 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 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 General Public License as published by + * the Free Software Foundation; either version 2 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 General Public License for more details. + * + * You should have received a copy of the GNU General Public License along + * with this program; if not, write to the Free Software Foundation, Inc., + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + * + */ + +/* 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. + */ + +#include <stdlib.h> +#include <unistd.h> +#include <errno.h> +#include <sys/types.h> + +#include <arpa/inet.h> + +#include <openbsc/gsm_data.h> +#include <osmocore/msgb.h> +#include <osmocore/tlv.h> +#include <osmocore/talloc.h> +#include <openbsc/debug.h> +#include <openbsc/gprs_ns.h> +#include <openbsc/gprs_bssgp.h> + +#define NS_ALLOC_SIZE 1024 + +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 }, + }, +}; + +#define NSE_S_BLOCKED 0x0001 +#define NSE_S_ALIVE 0x0002 + +struct gprs_nsvc { + struct llist_head list; + + u_int16_t nsei; /* end-to-end significance */ + u_int16_t nsvci; /* uniquely identifies NS-VC at SGSN */ + + u_int32_t state; + + struct timer_list alive_timer; + int timer_is_tns_alive; + int alive_retries; +}; + +/* FIXME: dynamically search for the matching NSVC */ +static struct gprs_nsvc dummy_nsvc = { .state = NSE_S_BLOCKED | NSE_S_ALIVE }; + +/* Section 10.3.2, Table 13 */ +static const char *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", +}; + +static const char *gprs_ns_cause_str(enum ns_cause cause) +{ + if (cause >= ARRAY_SIZE(ns_cause_str)) + return "undefined"; + + if (ns_cause_str[cause]) + return ns_cause_str[cause]; + + return "undefined"; +} + +static int gprs_ns_tx(struct msgb *msg) +{ + return ipac_gprs_send(msg); +} + +static int gprs_ns_tx_simple(struct gprs_ns_link *link, u_int8_t pdu_type) +{ + struct msgb *msg = msgb_alloc(NS_ALLOC_SIZE, "GPRS/NS"); + struct gprs_ns_hdr *nsh; + + if (!msg) + return -ENOMEM; + + nsh = (struct gprs_ns_hdr *) msgb_put(msg, sizeof(*nsh)); + + nsh->pdu_type = pdu_type; + + return gprs_ns_tx(msg); +} + +#define NS_TIMER_ALIVE 3, 0 /* after 3 seconds without response, we retry */ +#define NS_TIMER_TEST 30, 0 /* every 10 seconds we check if the BTS is still alive */ +#define NS_ALIVE_RETRIES 10 /* after 3 failed retransmit we declare BTS as dead */ + +static void gprs_ns_alive_cb(void *data) +{ + struct gprs_nsvc *nsvc = data; + + if (nsvc->timer_is_tns_alive) { + /* Tns-alive case: we expired without response ! */ + nsvc->alive_retries++; + if (nsvc->alive_retries > NS_ALIVE_RETRIES) { + /* mark as dead and blocked */ + nsvc->state = NSE_S_BLOCKED; + DEBUGP(DGPRS, "Tns-alive more then %u retries, " + " blocking NS-VC\n", NS_ALIVE_RETRIES); + /* FIXME: inform higher layers */ + return; + } + } else { + /* Tns-test case: send NS-ALIVE PDU */ + gprs_ns_tx_simple(NULL, NS_PDUT_ALIVE); + /* start Tns-alive timer */ + nsvc->timer_is_tns_alive = 1; + } + bsc_schedule_timer(&nsvc->alive_timer, NS_TIMER_ALIVE); +} + +/* Section 9.2.6 */ +static int gprs_ns_tx_reset_ack(u_int16_t nsvci, u_int16_t nsei) +{ + struct msgb *msg = msgb_alloc(NS_ALLOC_SIZE, "GPRS/NS"); + struct gprs_ns_hdr *nsh; + + if (!msg) + return -ENOMEM; + + nsvci = htons(nsvci); + nsei = htons(nsei); + + nsh = (struct gprs_ns_hdr *) msgb_put(msg, sizeof(*nsh)); + + nsh->pdu_type = NS_PDUT_RESET_ACK; + + msgb_tvlv_put(msg, NS_IE_VCI, 2, (u_int8_t *)&nsvci); + msgb_tvlv_put(msg, NS_IE_NSEI, 2, (u_int8_t *)&nsei); + + return gprs_ns_tx(msg); +} + +/* Section 9.2.10: transmit side */ +int gprs_ns_sendmsg(struct gprs_ns_link *link, u_int16_t bvci, + struct msgb *msg) +{ + struct gprs_ns_hdr *nsh; + + nsh = (struct gprs_ns_hdr *) msgb_push(msg, sizeof(*nsh) + 3); + if (!nsh) { + DEBUGP(DGPRS, "Not enough headroom for NS header\n"); + 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(msg); +} + +/* Section 9.2.10: receive side */ +static int gprs_ns_rx_unitdata(struct msgb *msg) +{ + struct gprs_ns_hdr *nsh = (struct gprs_ns_hdr *)msg->l2h; + u_int16_t bvci; + + /* spare octet in data[0] */ + bvci = nsh->data[1] << 8 | nsh->data[2]; + msg->l3h = &nsh->data[3]; + + /* call upper layer (BSSGP) */ + return gprs_bssgp_rcvmsg(msg, bvci); +} + +/* Section 9.2.7 */ +static int gprs_ns_rx_status(struct msgb *msg) +{ + struct gprs_ns_hdr *nsh = msg->l2h; + struct tlv_parsed tp; + u_int8_t cause; + int rc; + + DEBUGP(DGPRS, "NS STATUS "); + + rc = tlv_parse(&tp, &ns_att_tlvdef, nsh->data, msgb_l2len(msg), 0, 0); + + if (!TLVP_PRESENT(&tp, NS_IE_CAUSE)) { + DEBUGPC(DGPRS, "missing cause IE\n"); + return -EINVAL; + } + + cause = *TLVP_VAL(&tp, NS_IE_CAUSE); + DEBUGPC(DGPRS, "cause=%s\n", gprs_ns_cause_str(cause)); + + return 0; +} + +/* Section 7.3 */ +static int gprs_ns_rx_reset(struct msgb *msg) +{ + struct gprs_ns_hdr *nsh = (struct gprs_ns_hdr *) msg->l2h; + struct gprs_nsvc *nsvc = &dummy_nsvc; + struct tlv_parsed tp; + u_int8_t *cause; + u_int16_t *nsvci, *nsei; + int rc; + + DEBUGP(DGPRS, "NS RESET "); + + rc = tlv_parse(&tp, &ns_att_tlvdef, nsh->data, msgb_l2len(msg), 0, 0); + + if (!TLVP_PRESENT(&tp, NS_IE_CAUSE) || + !TLVP_PRESENT(&tp, NS_IE_VCI) || + !TLVP_PRESENT(&tp, NS_IE_NSEI)) { + /* FIXME: respond with NS_CAUSE_MISSING_ESSENT_IE */ + DEBUGPC(DGPRS, "Missing mandatory IE\n"); + return -EINVAL; + } + + cause = (u_int8_t *) TLVP_VAL(&tp, NS_IE_CAUSE); + nsvci = (u_int16_t *) TLVP_VAL(&tp, NS_IE_VCI); + nsei = (u_int16_t *) TLVP_VAL(&tp, NS_IE_NSEI); + + *nsvci = ntohs(*nsvci); + *nsei = ntohs(*nsei); + + DEBUGPC(DGPRS, "cause=%s, NSVCI=%u, NSEI=%u\n", + gprs_ns_cause_str(*cause), *nsvci, *nsei); + + /* mark the NS-VC as blocked and alive */ + nsvc->state = NSE_S_BLOCKED | NSE_S_ALIVE; + nsvc->nsei = *nsei; + nsvc->nsvci = *nsvci; + + /* start the test procedure */ + nsvc->alive_timer.cb = gprs_ns_alive_cb; + nsvc->alive_timer.data = nsvc; + bsc_schedule_timer(&nsvc->alive_timer, NS_TIMER_ALIVE); + + return gprs_ns_tx_reset_ack(*nsvci, *nsei); +} + +/* main entry point, here incoming NS frames enter */ +int gprs_ns_rcvmsg(struct msgb *msg) +{ + struct gprs_ns_hdr *nsh = (struct gprs_ns_hdr *) msg->l2h; + struct gprs_nsvc *nsvc = &dummy_nsvc; + int rc = 0; + + switch (nsh->pdu_type) { + case NS_PDUT_ALIVE: + /* remote end inquires whether we're still alive, + * we need to respond with ALIVE_ACK */ + rc = gprs_ns_tx_simple(NULL, NS_PDUT_ALIVE_ACK); + break; + case NS_PDUT_ALIVE_ACK: + /* stop Tns-alive */ + bsc_del_timer(&nsvc->alive_timer); + /* start Tns-test */ + nsvc->timer_is_tns_alive = 0; + bsc_schedule_timer(&nsvc->alive_timer, NS_TIMER_TEST); + break; + case NS_PDUT_UNITDATA: + /* actual user data */ + rc = gprs_ns_rx_unitdata(msg); + break; + case NS_PDUT_STATUS: + rc = gprs_ns_rx_status(msg); + break; + case NS_PDUT_RESET: + rc = gprs_ns_rx_reset(msg); + break; + case NS_PDUT_RESET_ACK: + /* FIXME: mark remote NS-VC as blocked + active */ + break; + case NS_PDUT_UNBLOCK: + /* Section 7.2: unblocking procedure */ + DEBUGP(DGPRS, "NS UNBLOCK\n"); + nsvc->state &= ~NSE_S_BLOCKED; + rc = gprs_ns_tx_simple(NULL, NS_PDUT_UNBLOCK_ACK); + break; + case NS_PDUT_UNBLOCK_ACK: + /* FIXME: mark remote NS-VC as unblocked + active */ + break; + case NS_PDUT_BLOCK: + DEBUGP(DGPRS, "NS BLOCK\n"); + nsvc->state |= NSE_S_BLOCKED; + rc = gprs_ns_tx_simple(NULL, NS_PDUT_UNBLOCK_ACK); + break; + case NS_PDUT_BLOCK_ACK: + /* FIXME: mark remote NS-VC as blocked + active */ + break; + default: + DEBUGP(DGPRS, "Unknown NS PDU type 0x%02x\n", nsh->pdu_type); + rc = -EINVAL; + break; + } + return rc; +} + |