diff options
Diffstat (limited to 'src/sgsn/gprs_sm.c')
-rw-r--r-- | src/sgsn/gprs_sm.c | 749 |
1 files changed, 749 insertions, 0 deletions
diff --git a/src/sgsn/gprs_sm.c b/src/sgsn/gprs_sm.c new file mode 100644 index 000000000..8cf5c5d88 --- /dev/null +++ b/src/sgsn/gprs_sm.c @@ -0,0 +1,749 @@ +/* Section "9.5 GPRS Session Management Messages" + * 3GPP TS 04.08 version 7.21.0 Release 1998 / ETSI TS 100 940 V7.21.0 */ + +/* (C) 2009-2015 by Harald Welte <laforge@gnumonks.org> + * (C) 2010 by On-Waves + * (C) 2019 by sysmocom s.f.m.c. GmbH <info@sysmocom.de> + * + * 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/>. + * + */ + +#include <netinet/in.h> +#include <arpa/inet.h> +#include <netdb.h> + +#include "bscconfig.h" + +#include <osmocom/core/rate_ctr.h> +#include <osmocom/core/tdef.h> +#include <osmocom/gsm/apn.h> +#include <osmocom/gprs/gprs_bssgp.h> + +#include <osmocom/sgsn/gprs_sm.h> +#include <osmocom/sgsn/gprs_gmm.h> +#include <osmocom/sgsn/gprs_utils.h> +#include <osmocom/sgsn/sgsn.h> +#include <osmocom/sgsn/debug.h> +#include <osmocom/sgsn/gprs_llc.h> +#include <osmocom/sgsn/gprs_sndcp.h> +#include <osmocom/sgsn/gprs_ranap.h> + +extern void *tall_sgsn_ctx; + +/* 3GPP TS 04.08 sec 6.1.3.4.3(.a) "Abnormal cases" */ +#define T339X_MAX_RETRANS 4 + +static const struct tlv_definition gsm48_sm_att_tlvdef = { + .def = { + [GSM48_IE_GSM_APN] = { TLV_TYPE_TLV, 0 }, + [GSM48_IE_GSM_PROTO_CONF_OPT] = { TLV_TYPE_TLV, 0 }, + [GSM48_IE_GSM_PDP_ADDR] = { TLV_TYPE_TLV, 0 }, + [GSM48_IE_GSM_AA_TMR] = { TLV_TYPE_TV, 1 }, + [GSM48_IE_GSM_NAME_FULL] = { TLV_TYPE_TLV, 0 }, + [GSM48_IE_GSM_NAME_SHORT] = { TLV_TYPE_TLV, 0 }, + [GSM48_IE_GSM_TIMEZONE] = { TLV_TYPE_FIXED, 1 }, + [GSM48_IE_GSM_UTC_AND_TZ] = { TLV_TYPE_FIXED, 7 }, + [GSM48_IE_GSM_LSA_ID] = { TLV_TYPE_TLV, 0 }, + }, +}; + +static struct gsm48_qos default_qos = { + .delay_class = 4, /* best effort */ + .reliab_class = GSM48_QOS_RC_LLC_UN_RLC_ACK_DATA_PROT, + .peak_tput = GSM48_QOS_PEAK_TPUT_32000bps, + .preced_class = GSM48_QOS_PC_NORMAL, + .mean_tput = GSM48_QOS_MEAN_TPUT_BEST_EFFORT, + .traf_class = GSM48_QOS_TC_INTERACTIVE, + .deliv_order = GSM48_QOS_DO_UNORDERED, + .deliv_err_sdu = GSM48_QOS_ERRSDU_YES, + .max_sdu_size = GSM48_QOS_MAXSDU_1520, + .max_bitrate_up = GSM48_QOS_MBRATE_63k, + .max_bitrate_down = GSM48_QOS_MBRATE_63k, + .resid_ber = GSM48_QOS_RBER_5e_2, + .sdu_err_ratio = GSM48_QOS_SERR_1e_2, + .handling_prio = 3, + .xfer_delay = 0x10, /* 200ms */ + .guar_bitrate_up = GSM48_QOS_MBRATE_0k, + .guar_bitrate_down = GSM48_QOS_MBRATE_0k, + .sig_ind = 0, /* not optimised for signalling */ + .max_bitrate_down_ext = 0, /* use octet 9 */ + .guar_bitrate_down_ext = 0, /* use octet 13 */ +}; + +/* GPRS SESSION MANAGEMENT */ + +static void pdpctx_timer_cb(void *_mm); + +static void pdpctx_timer_rearm(struct sgsn_pdp_ctx *pdp, unsigned int T) +{ + unsigned long seconds; + if (osmo_timer_pending(&pdp->timer)) + LOGPDPCTXP(LOGL_ERROR, pdp, "Scheduling PDP timer %u while old " + "timer %u pending\n", T, pdp->T); + seconds = osmo_tdef_get(sgsn->cfg.T_defs, T, OSMO_TDEF_S, -1); + osmo_timer_schedule(&pdp->timer, seconds, 0); +} + +static void pdpctx_timer_start(struct sgsn_pdp_ctx *pdp, unsigned int T) +{ + if (osmo_timer_pending(&pdp->timer)) + LOGPDPCTXP(LOGL_ERROR, pdp, "Starting PDP timer %u while old " + "timer %u pending\n", T, pdp->T); + pdp->T = T; + pdp->num_T_exp = 0; + + osmo_timer_setup(&pdp->timer, pdpctx_timer_cb, pdp); + pdpctx_timer_rearm(pdp, pdp->T); +} + +static void pdpctx_timer_stop(struct sgsn_pdp_ctx *pdp, unsigned int T) +{ + if (pdp->T != T) + LOGPDPCTXP(LOGL_ERROR, pdp, "Stopping PDP timer %u but " + "%u is running\n", T, pdp->T); + osmo_timer_del(&pdp->timer); +} + +void pdp_ctx_detach_mm_ctx(struct sgsn_pdp_ctx *pdp) +{ + /* Detach from MM context */ + llist_del(&pdp->list); + pdp->mm = NULL; + + /* stop timer 3395 */ + pdpctx_timer_stop(pdp, 3395); +} + +#if 0 +static void msgb_put_pdp_addr_ipv4(struct msgb *msg, uint32_t ipaddr) +{ + uint8_t v[6]; + + v[0] = PDP_TYPE_ORG_IETF; + v[1] = PDP_TYPE_N_IETF_IPv4; + *(uint32_t *)(v+2) = htonl(ipaddr); + + msgb_tlv_put(msg, GSM48_IE_GSM_PDP_ADDR, sizeof(v), v); +} + +static void msgb_put_pdp_addr_ppp(struct msgb *msg) +{ + uint8_t v[2]; + + v[0] = PDP_TYPE_ORG_ETSI; + v[1] = PDP_TYPE_N_ETSI_PPP; + + msgb_tlv_put(msg, GSM48_IE_GSM_PDP_ADDR, sizeof(v), v); +} +#endif + +/* Chapter 9.4.18 */ +static int _tx_status(struct msgb *msg, uint8_t cause, + struct sgsn_mm_ctx *mmctx) +{ + struct gsm48_hdr *gh; + + /* MMCTX might be NULL! */ + + DEBUGP(DMM, "<- GPRS MM STATUS (cause: %s)\n", + get_value_string(gsm48_gmm_cause_names, cause)); + + gh = (struct gsm48_hdr *) msgb_put(msg, sizeof(*gh) + 1); + gh->proto_discr = GSM48_PDISC_SM_GPRS; + gh->msg_type = GSM48_MT_GSM_STATUS; + gh->data[0] = cause; + + return gsm48_gmm_sendmsg(msg, 0, mmctx, true); +} + +static int gsm48_tx_sm_status(struct sgsn_mm_ctx *mmctx, uint8_t cause) +{ + struct msgb *msg = gsm48_msgb_alloc_name("GSM 04.08 SM STATUS"); + + mmctx2msgid(msg, mmctx); + return _tx_status(msg, cause, mmctx); +} + +/* 3GPP TS 24.008 § 9.5.2: Activate PDP Context Accept */ +int gsm48_tx_gsm_act_pdp_acc(struct sgsn_pdp_ctx *pdp) +{ + struct msgb *msg = gsm48_msgb_alloc_name("GSM 04.08 PDP ACC"); + struct gsm48_hdr *gh; + uint8_t transaction_id = pdp->ti ^ 0x8; /* flip */ + + LOGPDPCTXP(LOGL_INFO, pdp, "<- ACTIVATE PDP CONTEXT ACK\n"); + rate_ctr_inc(&sgsn->rate_ctrs->ctr[CTR_PDP_ACTIVATE_ACCEPT]); + + mmctx2msgid(msg, pdp->mm); + + gh = (struct gsm48_hdr *) msgb_put(msg, sizeof(*gh)); + gh->proto_discr = GSM48_PDISC_SM_GPRS | (transaction_id << 4); + gh->msg_type = GSM48_MT_GSM_ACT_PDP_ACK; + + /* Negotiated LLC SAPI */ + msgb_v_put(msg, pdp->sapi); + + /* FIXME: copy QoS parameters from original request */ + //msgb_lv_put(msg, pdp->lib->qos_neg.l, pdp->lib->qos_neg.v); + msgb_lv_put(msg, sizeof(default_qos), (uint8_t *)&default_qos); + + /* Radio priority 10.5.7.2 */ + msgb_v_put(msg, pdp->lib->radio_pri); + + /* PDP address */ + /* Highest 4 bits of first byte need to be set to 1, otherwise + * the IE is identical with the 04.08 PDP Address IE */ + pdp->lib->eua.v[0] &= ~0xf0; + msgb_tlv_put(msg, GSM48_IE_GSM_PDP_ADDR, + pdp->lib->eua.l, pdp->lib->eua.v); + pdp->lib->eua.v[0] |= 0xf0; + + /* Optional: Protocol configuration options (FIXME: why 'req') */ + if (pdp->lib->pco_req.l) + msgb_tlv_put(msg, GSM48_IE_GSM_PROTO_CONF_OPT, + pdp->lib->pco_req.l, pdp->lib->pco_req.v); + + /* Optional: Packet Flow Identifier */ + + return gsm48_gmm_sendmsg(msg, 0, pdp->mm, true); +} + +/* 3GPP TS 24.008 § 9.5.3: Activate PDP Context reject */ +int gsm48_tx_gsm_act_pdp_rej(struct sgsn_mm_ctx *mm, uint8_t tid, + uint8_t cause, uint8_t pco_len, uint8_t *pco_v) +{ + struct msgb *msg = gsm48_msgb_alloc_name("GSM 04.08 PDP REJ"); + struct gsm48_hdr *gh; + uint8_t transaction_id = tid ^ 0x8; /* flip */ + + LOGMMCTXP(LOGL_NOTICE, mm, "<- ACTIVATE PDP CONTEXT REJ: %s\n", + get_value_string(gsm48_gsm_cause_names, cause)); + rate_ctr_inc(&sgsn->rate_ctrs->ctr[CTR_PDP_ACTIVATE_REJECT]); + + mmctx2msgid(msg, mm); + + gh = (struct gsm48_hdr *) msgb_put(msg, sizeof(*gh)); + gh->proto_discr = GSM48_PDISC_SM_GPRS | (transaction_id << 4); + gh->msg_type = GSM48_MT_GSM_ACT_PDP_REJ; + + msgb_v_put(msg, cause); + if (pco_len && pco_v) + msgb_tlv_put(msg, GSM48_IE_GSM_PROTO_CONF_OPT, pco_len, pco_v); + + return gsm48_gmm_sendmsg(msg, 0, mm, true); +} + +/* 3GPP TS 24.008 § 9.5.8: Deactivate PDP Context Request */ +static int _gsm48_tx_gsm_deact_pdp_req(struct sgsn_mm_ctx *mm, uint8_t tid, + uint8_t sm_cause, bool teardown) +{ + struct msgb *msg = gsm48_msgb_alloc_name("GSM 04.08 PDP DET REQ"); + struct gsm48_hdr *gh; + uint8_t transaction_id = tid ^ 0x8; /* flip */ + uint8_t tear_down_ind = (0x9 << 4) | (!!teardown); + + LOGMMCTXP(LOGL_INFO, mm, "<- DEACTIVATE PDP CONTEXT REQ\n"); + rate_ctr_inc(&sgsn->rate_ctrs->ctr[CTR_PDP_DL_DEACTIVATE_REQUEST]); + + mmctx2msgid(msg, mm); + + gh = (struct gsm48_hdr *) msgb_put(msg, sizeof(*gh)); + gh->proto_discr = GSM48_PDISC_SM_GPRS | (transaction_id << 4); + gh->msg_type = GSM48_MT_GSM_DEACT_PDP_REQ; + + msgb_v_put(msg, sm_cause); + msgb_v_put(msg, tear_down_ind); + + return gsm48_gmm_sendmsg(msg, 0, mm, true); +} +int gsm48_tx_gsm_deact_pdp_req(struct sgsn_pdp_ctx *pdp, uint8_t sm_cause, bool teardown) +{ + pdpctx_timer_start(pdp, 3395); + + return _gsm48_tx_gsm_deact_pdp_req(pdp->mm, pdp->ti, sm_cause, teardown); +} + +/* 3GPP TS 24.008 § 9.5.9: Deactivate PDP Context Accept */ +static int _gsm48_tx_gsm_deact_pdp_acc(struct sgsn_mm_ctx *mm, uint8_t tid) +{ + struct msgb *msg = gsm48_msgb_alloc_name("GSM 04.08 PDP DET ACC"); + struct gsm48_hdr *gh; + uint8_t transaction_id = tid ^ 0x8; /* flip */ + + LOGMMCTXP(LOGL_INFO, mm, "<- DEACTIVATE PDP CONTEXT ACK\n"); + rate_ctr_inc(&sgsn->rate_ctrs->ctr[CTR_PDP_DL_DEACTIVATE_ACCEPT]); + + mmctx2msgid(msg, mm); + + gh = (struct gsm48_hdr *) msgb_put(msg, sizeof(*gh)); + gh->proto_discr = GSM48_PDISC_SM_GPRS | (transaction_id << 4); + gh->msg_type = GSM48_MT_GSM_DEACT_PDP_ACK; + + return gsm48_gmm_sendmsg(msg, 0, mm, true); +} +int gsm48_tx_gsm_deact_pdp_acc(struct sgsn_pdp_ctx *pdp) +{ + return _gsm48_tx_gsm_deact_pdp_acc(pdp->mm, pdp->ti); +} + +static int activate_ggsn(struct sgsn_mm_ctx *mmctx, + struct sgsn_ggsn_ctx *ggsn, const uint8_t transaction_id, + const uint8_t req_nsapi, const uint8_t req_llc_sapi, + struct tlv_parsed *tp, int destroy_ggsn) +{ + struct sgsn_pdp_ctx *pdp; + + LOGMMCTXP(LOGL_DEBUG, mmctx, "Using GGSN %u\n", ggsn->id); + ggsn->gsn = sgsn->gsn; + pdp = sgsn_create_pdp_ctx(ggsn, mmctx, req_nsapi, tp); + if (!pdp) + return -1; + + /* Store SAPI and Transaction Identifier */ + pdp->sapi = req_llc_sapi; + pdp->ti = transaction_id; + pdp->destroy_ggsn = destroy_ggsn; + + return 0; +} + +static void ggsn_lookup_cb(void *arg, int status, int timeouts, struct hostent *hostent) +{ + struct sgsn_ggsn_ctx *ggsn; + struct sgsn_ggsn_lookup *lookup = arg; + struct in_addr *addr = NULL; + char buf[INET_ADDRSTRLEN]; + + /* The context is gone while we made a request */ + if (!lookup->mmctx) { + talloc_free(lookup->orig_msg); + talloc_free(lookup); + return; + } + + if (status != ARES_SUCCESS) { + struct sgsn_mm_ctx *mmctx = lookup->mmctx; + + LOGMMCTXP(LOGL_ERROR, mmctx, "DNS query failed.\n"); + + /* Need to try with three digits now */ + if (lookup->state == SGSN_GGSN_2DIGIT) { + char *hostname; + int rc; + + lookup->state = SGSN_GGSN_3DIGIT; + hostname = osmo_apn_qualify_from_imsi(mmctx->imsi, + lookup->apn_str, 1); + LOGMMCTXP(LOGL_DEBUG, mmctx, + "Going to query %s\n", hostname); + rc = sgsn_ares_query(sgsn, hostname, + ggsn_lookup_cb, lookup); + if (rc != 0) { + LOGMMCTXP(LOGL_ERROR, mmctx, "Couldn't start GGSN\n"); + goto reject_due_failure; + } + return; + } + + LOGMMCTXP(LOGL_ERROR, mmctx, "Couldn't resolve GGSN\n"); + goto reject_due_failure; + } + + if (hostent->h_length != sizeof(struct in_addr)) { + LOGMMCTXP(LOGL_ERROR, lookup->mmctx, + "Wrong addr size(%zu)\n", sizeof(struct in_addr)); + goto reject_due_failure; + } + + /* Get the first addr from the list */ + addr = (struct in_addr *) hostent->h_addr_list[0]; + if (!addr) { + LOGMMCTXP(LOGL_ERROR, lookup->mmctx, "No host address.\n"); + goto reject_due_failure; + } + + ggsn = sgsn_ggsn_ctx_alloc(UINT32_MAX); + if (!ggsn) { + LOGMMCTXP(LOGL_ERROR, lookup->mmctx, "Failed to create ggsn.\n"); + goto reject_due_failure; + } + ggsn->remote_addr = *addr; + LOGMMCTXP(LOGL_NOTICE, lookup->mmctx, + "Selected %s as GGSN.\n", + inet_ntop(AF_INET, addr, buf, sizeof(buf))); + + /* forget about the ggsn look-up */ + lookup->mmctx->ggsn_lookup = NULL; + + activate_ggsn(lookup->mmctx, ggsn, lookup->ti, lookup->nsapi, + lookup->sapi, &lookup->tp, 1); + + /* Now free it */ + talloc_free(lookup->orig_msg); + talloc_free(lookup); + return; + +reject_due_failure: + gsm48_tx_gsm_act_pdp_rej(lookup->mmctx, lookup->ti, + GMM_CAUSE_NET_FAIL, 0, NULL); + lookup->mmctx->ggsn_lookup = NULL; + talloc_free(lookup->orig_msg); + talloc_free(lookup); +} + +static int do_act_pdp_req(struct sgsn_mm_ctx *mmctx, struct msgb *msg, bool *delete) +{ + struct gsm48_hdr *gh = (struct gsm48_hdr *) msgb_gmmh(msg); + struct gsm48_act_pdp_ctx_req *act_req = (struct gsm48_act_pdp_ctx_req *) gh->data; + uint8_t req_qos_len, req_pdpa_len; + uint8_t *req_qos, *req_pdpa; + struct tlv_parsed tp; + uint8_t transaction_id = gsm48_hdr_trans_id(gh); + struct sgsn_ggsn_ctx *ggsn; + struct sgsn_pdp_ctx *pdp; + enum gsm48_gsm_cause gsm_cause; + char apn_str[GSM_APN_LENGTH] = { 0, }; + char *hostname; + int rc; + struct gprs_llc_lle *lle; + char buf[INET_ADDRSTRLEN]; + + LOGMMCTXP(LOGL_INFO, mmctx, "-> ACTIVATE PDP CONTEXT REQ: SAPI=%u NSAPI=%u ", + act_req->req_llc_sapi, act_req->req_nsapi); + + /* FIXME: length checks! */ + req_qos_len = act_req->data[0]; + req_qos = act_req->data + 1; /* 10.5.6.5 */ + req_pdpa_len = act_req->data[1 + req_qos_len]; + req_pdpa = act_req->data + 1 + req_qos_len + 1; /* 10.5.6.4 */ + + switch (req_pdpa[0] & 0xf) { + case 0x0: + DEBUGPC(DMM, "ETSI "); + break; + case 0x1: + DEBUGPC(DMM, "IETF "); + break; + case 0xf: + DEBUGPC(DMM, "Empty "); + break; + } + + switch (req_pdpa[1]) { + case 0x21: + DEBUGPC(DMM, "IPv4 "); + if (req_pdpa_len >= 6) { + struct in_addr ia; + ia.s_addr = ntohl(*((uint32_t *) (req_pdpa+2))); + DEBUGPC(DMM, "%s ", inet_ntop(AF_INET, &ia, buf, sizeof(buf))); + } + break; + case 0x57: + DEBUGPC(DMM, "IPv6 "); + if (req_pdpa_len >= 18) { + /* FIXME: print IPv6 address */ + } + break; + default: + DEBUGPC(DMM, "0x%02x ", req_pdpa[1]); + break; + } + + LOGPC(DMM, LOGL_INFO, "\n"); + + /* Check if NSAPI is out of range (TS 04.65 / 7.2) */ + if (act_req->req_nsapi < 5 || act_req->req_nsapi > 15) { + /* Send reject with GSM_CAUSE_INV_MAND_INFO */ + return gsm48_tx_gsm_act_pdp_rej(mmctx, transaction_id, + GSM_CAUSE_INV_MAND_INFO, + 0, NULL); + } + + /* Optional: Access Point Name, Protocol Config Options */ + if (req_pdpa + req_pdpa_len < msg->data + msg->len) + tlv_parse(&tp, &gsm48_sm_att_tlvdef, req_pdpa + req_pdpa_len, + (msg->data + msg->len) - (req_pdpa + req_pdpa_len), 0, 0); + else + memset(&tp, 0, sizeof(tp)); + + + /* put the non-TLV elements in the TLV parser structure to + * pass them on to the SGSN / GTP code */ + tp.lv[OSMO_IE_GSM_REQ_QOS].len = req_qos_len; + tp.lv[OSMO_IE_GSM_REQ_QOS].val = req_qos; + tp.lv[OSMO_IE_GSM_REQ_PDP_ADDR].len = req_pdpa_len; + tp.lv[OSMO_IE_GSM_REQ_PDP_ADDR].val = req_pdpa; + + /* Check if NSAPI is already in use */ + pdp = sgsn_pdp_ctx_by_nsapi(mmctx, act_req->req_nsapi); + if (pdp) { + /* We already have a PDP context for this TLLI + NSAPI tuple */ + if (pdp->sapi == act_req->req_llc_sapi && + pdp->ti == transaction_id) { + /* This apparently is a re-transmission of a PDP CTX + * ACT REQ (our ACT ACK must have got dropped) */ + rc = gsm48_tx_gsm_act_pdp_acc(pdp); + if (rc < 0) + return rc; + + if (pdp->mm->ran_type == MM_CTX_T_GERAN_Gb) { + /* Also re-transmit the SNDCP XID message */ + lle = &pdp->mm->gb.llme->lle[pdp->sapi]; + rc = sndcp_sn_xid_req(lle,pdp->nsapi); + if (rc < 0) + return rc; + } + + return 0; + } + + /* Send reject with GSM_CAUSE_NSAPI_IN_USE */ + return gsm48_tx_gsm_act_pdp_rej(mmctx, transaction_id, + GSM_CAUSE_NSAPI_IN_USE, + 0, NULL); + } + + if (mmctx->ggsn_lookup) { + if (mmctx->ggsn_lookup->sapi == act_req->req_llc_sapi && + mmctx->ggsn_lookup->ti == transaction_id) { + LOGMMCTXP(LOGL_NOTICE, mmctx, + "Re-transmission while doing look-up. Ignoring.\n"); + return 0; + } + } + + /* Only increment counter for a real activation, after we checked + * for re-transmissions */ + rate_ctr_inc(&mmctx->ctrg->ctr[GMM_CTR_PDP_CTX_ACT]); + + /* Determine GGSN based on APN and subscription options */ + ggsn = sgsn_mm_ctx_find_ggsn_ctx(mmctx, &tp, &gsm_cause, apn_str); + if (ggsn) + return activate_ggsn(mmctx, ggsn, transaction_id, + act_req->req_nsapi, act_req->req_llc_sapi, + &tp, 0); + + if (strlen(apn_str) == 0) + goto no_context; + if (!sgsn->cfg.dynamic_lookup) + goto no_context; + + /* schedule a dynamic look-up */ + mmctx->ggsn_lookup = talloc_zero(tall_sgsn_ctx, struct sgsn_ggsn_lookup); + if (!mmctx->ggsn_lookup) + goto no_context; + + mmctx->ggsn_lookup->state = SGSN_GGSN_2DIGIT; + mmctx->ggsn_lookup->mmctx = mmctx; + strcpy(mmctx->ggsn_lookup->apn_str, apn_str); + + mmctx->ggsn_lookup->orig_msg = msg; + mmctx->ggsn_lookup->tp = tp; + + mmctx->ggsn_lookup->ti = transaction_id; + mmctx->ggsn_lookup->nsapi = act_req->req_nsapi; + mmctx->ggsn_lookup->sapi = act_req->req_llc_sapi; + + hostname = osmo_apn_qualify_from_imsi(mmctx->imsi, + mmctx->ggsn_lookup->apn_str, 0); + + LOGMMCTXP(LOGL_DEBUG, mmctx, "Going to query %s\n", hostname); + rc = sgsn_ares_query(sgsn, hostname, + ggsn_lookup_cb, mmctx->ggsn_lookup); + if (rc != 0) { + LOGMMCTXP(LOGL_ERROR, mmctx, "Failed to start ares query.\n"); + goto no_context; + } + *delete = 0; + + return 0; + +no_context: + LOGMMCTXP(LOGL_ERROR, mmctx, "No GGSN context found!\n"); + return gsm48_tx_gsm_act_pdp_rej(mmctx, transaction_id, + gsm_cause, 0, NULL); +} + +/* 3GPP TS 24.008 § 9.5.1: Activate PDP Context Request */ +static int gsm48_rx_gsm_act_pdp_req(struct sgsn_mm_ctx *mmctx, + struct msgb *_msg) +{ + bool delete = 1; + struct msgb *msg; + int rc; + + rate_ctr_inc(&sgsn->rate_ctrs->ctr[CTR_PDP_ACTIVATE_REQUEST]); + + /* + * This is painful. We might not have a static GGSN + * configuration and then would need to copy the msg + * and re-do most of this routine (or call it again + * and make sure it only goes through the dynamic + * resolving. The question is what to optimize for + * and the dynamic resolution will be the right thing + * in the long run. + */ + msg = bssgp_msgb_copy(_msg, __func__); + if (!msg) { + struct gsm48_hdr *gh = (struct gsm48_hdr *) msgb_gmmh(_msg); + uint8_t transaction_id = gsm48_hdr_trans_id(gh); + + LOGMMCTXP(LOGL_ERROR, mmctx, "-> ACTIVATE PDP CONTEXT REQ failed copy.\n"); + /* Send reject with GSM_CAUSE_INV_MAND_INFO */ + return gsm48_tx_gsm_act_pdp_rej(mmctx, transaction_id, + GSM_CAUSE_NET_FAIL, + 0, NULL); + } + + rc = do_act_pdp_req(mmctx, msg, &delete); + if (delete) + msgb_free(msg); + return rc; +} + +/* 3GPP TS 24.008 § 9.5.8: Deactivate PDP Context Request */ +static int gsm48_rx_gsm_deact_pdp_req(struct sgsn_mm_ctx *mm, struct msgb *msg) +{ + struct gsm48_hdr *gh = (struct gsm48_hdr *) msgb_gmmh(msg); + uint8_t transaction_id = gsm48_hdr_trans_id(gh); + struct sgsn_pdp_ctx *pdp; + + LOGMMCTXP(LOGL_INFO, mm, "-> DEACTIVATE PDP CONTEXT REQ (cause: %s)\n", + get_value_string(gsm48_gsm_cause_names, gh->data[0])); + rate_ctr_inc(&sgsn->rate_ctrs->ctr[CTR_PDP_UL_DEACTIVATE_REQUEST]); + + pdp = sgsn_pdp_ctx_by_tid(mm, transaction_id); + if (!pdp) { + LOGMMCTXP(LOGL_NOTICE, mm, "Deactivate PDP Context Request for " + "non-existing PDP Context (IMSI=%s, TI=%u)\n", + mm->imsi, transaction_id); + return _gsm48_tx_gsm_deact_pdp_acc(mm, transaction_id); + } + + return sgsn_delete_pdp_ctx(pdp); +} + +/* 3GPP TS 24.008 § 9.5.9: Deactivate PDP Context Accept */ +static int gsm48_rx_gsm_deact_pdp_ack(struct sgsn_mm_ctx *mm, struct msgb *msg) +{ + struct gsm48_hdr *gh = (struct gsm48_hdr *) msgb_gmmh(msg); + uint8_t transaction_id = gsm48_hdr_trans_id(gh); + struct sgsn_pdp_ctx *pdp; + + LOGMMCTXP(LOGL_INFO, mm, "-> DEACTIVATE PDP CONTEXT ACK\n"); + rate_ctr_inc(&sgsn->rate_ctrs->ctr[CTR_PDP_UL_DEACTIVATE_ACCEPT]); + + pdp = sgsn_pdp_ctx_by_tid(mm, transaction_id); + if (!pdp) { + LOGMMCTXP(LOGL_NOTICE, mm, "Deactivate PDP Context Accept for " + "non-existing PDP Context (IMSI=%s, TI=%u)\n", + mm->imsi, transaction_id); + return 0; + } + /* stop timer 3395 */ + pdpctx_timer_stop(pdp, 3395); + if (pdp->ggsn) + return sgsn_delete_pdp_ctx(pdp); + /* GTP side already detached, freeing */ + sgsn_pdp_ctx_free(pdp); + return 0; +} + +static int gsm48_rx_gsm_status(struct sgsn_mm_ctx *ctx, struct msgb *msg) +{ + struct gsm48_hdr *gh = msgb_l3(msg); + + LOGMMCTXP(LOGL_INFO, ctx, "-> GPRS SM STATUS (cause: %s)\n", + get_value_string(gsm48_gsm_cause_names, gh->data[0])); + + return 0; +} + +static void pdpctx_timer_cb(void *_pdp) +{ + struct sgsn_pdp_ctx *pdp = _pdp; + + pdp->num_T_exp++; + + switch (pdp->T) { + case 3395: /* waiting for PDP CTX DEACT ACK */ + if (pdp->num_T_exp > T339X_MAX_RETRANS) { + LOGPDPCTXP(LOGL_NOTICE, pdp, "T3395 expired > %d times\n", T339X_MAX_RETRANS); + pdp->state = PDP_STATE_INACTIVE; + if (pdp->ggsn) + sgsn_delete_pdp_ctx(pdp); + else + sgsn_pdp_ctx_free(pdp); + break; + } + _gsm48_tx_gsm_deact_pdp_req(pdp->mm, pdp->ti, GSM_CAUSE_NET_FAIL, true); + pdpctx_timer_rearm(pdp, 3395); + break; + default: + LOGPDPCTXP(LOGL_ERROR, pdp, "timer expired in unknown mode %u\n", + pdp->T); + } +} + +/* GPRS Session Management */ +int gsm0408_rcv_gsm(struct sgsn_mm_ctx *mmctx, struct msgb *msg, + struct gprs_llc_llme *llme) +{ + struct gsm48_hdr *gh = (struct gsm48_hdr *) msgb_gmmh(msg); + int rc; + + /* MMCTX can be NULL when called */ + + if (!mmctx) { + LOGGBIUP(llme, msg, LOGL_NOTICE, "Cannot handle SM for unknown MM CTX\n"); + /* 6.1.3.6 */ + if (gh->msg_type == GSM48_MT_GSM_STATUS) + return 0; + + return gsm0408_gprs_force_reattach_oldmsg(msg, llme); + } + + switch (gh->msg_type) { + case GSM48_MT_GSM_ACT_PDP_REQ: + rc = gsm48_rx_gsm_act_pdp_req(mmctx, msg); + break; + case GSM48_MT_GSM_DEACT_PDP_REQ: + rc = gsm48_rx_gsm_deact_pdp_req(mmctx, msg); + break; + case GSM48_MT_GSM_DEACT_PDP_ACK: + rc = gsm48_rx_gsm_deact_pdp_ack(mmctx, msg); + break; + case GSM48_MT_GSM_STATUS: + rc = gsm48_rx_gsm_status(mmctx, msg); + break; + case GSM48_MT_GSM_REQ_PDP_ACT_REJ: + case GSM48_MT_GSM_ACT_AA_PDP_REQ: + case GSM48_MT_GSM_DEACT_AA_PDP_REQ: + LOGMMCTXP(LOGL_NOTICE, mmctx, "Unimplemented GSM 04.08 GSM msg type 0x%02x: %s\n", + gh->msg_type, osmo_hexdump((uint8_t *)gh, msgb_l3len(msg))); + rc = gsm48_tx_sm_status(mmctx, GSM_CAUSE_MSGT_NOTEXIST_NOTIMPL); + break; + default: + LOGMMCTXP(LOGL_NOTICE, mmctx, "Unknown GSM 04.08 GSM msg type 0x%02x: %s\n", + gh->msg_type, osmo_hexdump((uint8_t *)gh, msgb_l3len(msg))); + rc = gsm48_tx_sm_status(mmctx, GSM_CAUSE_MSGT_NOTEXIST_NOTIMPL); + break; + + } + + return rc; +} |