| /* Gb proxy peer handling */ |
| |
| /* (C) 2010 by Harald Welte <laforge@gnumonks.org> |
| * (C) 2010-2013 by On-Waves |
| * (C) 2013 by Holger Hans Peter Freyther |
| * 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 <osmocom/sgsn/gb_proxy.h> |
| |
| #include <osmocom/sgsn/debug.h> |
| |
| #include <osmocom/gprs/protocol/gsm_08_18.h> |
| #include <osmocom/core/logging.h> |
| #include <osmocom/core/linuxlist.h> |
| #include <osmocom/core/rate_ctr.h> |
| #include <osmocom/core/stats.h> |
| #include <osmocom/core/talloc.h> |
| #include <osmocom/gsm/tlv.h> |
| |
| #include <string.h> |
| |
| extern void *tall_sgsn_ctx; |
| |
| static const struct rate_ctr_desc bvc_ctr_description[] = { |
| { "blocked", "BVC Block " }, |
| { "unblocked", "BVC Unblock " }, |
| { "dropped", "BVC blocked, dropped packet " }, |
| { "inv-nsei", "NSEI mismatch " }, |
| { "tx-err", "NS Transmission error " }, |
| }; |
| |
| osmo_static_assert(ARRAY_SIZE(bvc_ctr_description) == GBPROX_PEER_CTR_LAST, everything_described); |
| |
| static const struct rate_ctr_group_desc bvc_ctrg_desc = { |
| .group_name_prefix = "gbproxy:peer", |
| .group_description = "GBProxy Peer Statistics", |
| .num_ctr = ARRAY_SIZE(bvc_ctr_description), |
| .ctr_desc = bvc_ctr_description, |
| .class_id = OSMO_STATS_CLASS_PEER, |
| }; |
| |
| |
| /* Find the gbproxy_bvc by its BVCI. There can only be one match */ |
| struct gbproxy_bvc *gbproxy_bvc_by_bvci(struct gbproxy_nse *nse, uint16_t bvci) |
| { |
| struct gbproxy_bvc *bvc; |
| hash_for_each_possible(nse->bvcs, bvc, list, bvci) { |
| if (bvc->bvci == bvci) |
| return bvc; |
| } |
| return NULL; |
| } |
| |
| struct gbproxy_bvc *gbproxy_bvc_alloc(struct gbproxy_nse *nse, uint16_t bvci) |
| { |
| struct gbproxy_bvc *bvc; |
| OSMO_ASSERT(nse); |
| struct gbproxy_config *cfg = nse->cfg; |
| OSMO_ASSERT(cfg); |
| |
| bvc = talloc_zero(tall_sgsn_ctx, struct gbproxy_bvc); |
| if (!bvc) |
| return NULL; |
| |
| bvc->bvci = bvci; |
| bvc->ctrg = rate_ctr_group_alloc(bvc, &bvc_ctrg_desc, (nse->nsei << 16) | bvci); |
| if (!bvc->ctrg) { |
| talloc_free(bvc); |
| return NULL; |
| } |
| bvc->nse = nse; |
| |
| hash_add(nse->bvcs, &bvc->list, bvc->bvci); |
| |
| LOGPBVC_CAT(bvc, DOBJ, LOGL_INFO, "BVC Created\n"); |
| |
| /* We leave allocating the bvc->fi to the caller, as the FSM details depend |
| * on the type of BVC (SIG/PTP) and role (SGSN/BSS) */ |
| |
| return bvc; |
| } |
| |
| void gbproxy_bvc_free(struct gbproxy_bvc *bvc) |
| { |
| struct gbproxy_cell *cell; |
| |
| if (!bvc) |
| return; |
| |
| LOGPBVC_CAT(bvc, DOBJ, LOGL_INFO, "BVC Destroying\n"); |
| |
| hash_del(&bvc->list); |
| |
| rate_ctr_group_free(bvc->ctrg); |
| bvc->ctrg = NULL; |
| |
| osmo_fsm_inst_free(bvc->fi); |
| |
| cell = bvc->cell; |
| if (cell) { |
| int i; |
| |
| if (cell->bss_bvc == bvc) |
| cell->bss_bvc = NULL; |
| |
| /* we could also be a SGSN-side BVC */ |
| for (i = 0; i < ARRAY_SIZE(cell->sgsn_bvc); i++) { |
| if (cell->sgsn_bvc[i] == bvc) |
| cell->sgsn_bvc[i] = NULL; |
| } |
| bvc->cell = NULL; |
| } |
| |
| talloc_free(bvc); |
| } |
| |
| /*! remove BVCs on NSE specified by NSEI. |
| * \param[in] cfg proxy in which we operate |
| * \param[in] nsei NS entity in which we should clean up |
| * \param[in] bvci if 0: remove all PTP BVCs; if != 0: BVCI of the single BVC to clean up */ |
| int gbproxy_cleanup_bvcs(struct gbproxy_nse *nse, uint16_t bvci) |
| { |
| struct hlist_node *btmp; |
| struct gbproxy_bvc *bvc; |
| int j, counter = 0; |
| |
| if (!nse) |
| return 0; |
| |
| hash_for_each_safe(nse->bvcs, j, btmp, bvc, list) { |
| if (bvci && bvc->bvci != bvci) |
| continue; |
| if (bvci == 0 && bvc->bvci == 0) |
| continue; |
| |
| gbproxy_bvc_free(bvc); |
| counter += 1; |
| } |
| |
| return counter; |
| } |
| |
| |
| /*********************************************************************** |
| * CELL |
| ***********************************************************************/ |
| |
| /* Allocate a new 'cell' object */ |
| struct gbproxy_cell *gbproxy_cell_alloc(struct gbproxy_config *cfg, uint16_t bvci) |
| { |
| struct gbproxy_cell *cell; |
| OSMO_ASSERT(cfg); |
| |
| cell = talloc_zero(cfg, struct gbproxy_cell); |
| if (!cell) |
| return NULL; |
| |
| cell->cfg = cfg; |
| cell->bvci = bvci; |
| |
| hash_add(cfg->cells, &cell->list, cell->bvci); |
| |
| LOGPCELL_CAT(cell, DOBJ, LOGL_INFO, "CELL Created\n"); |
| |
| return cell; |
| } |
| |
| /* Find cell by BVCI */ |
| struct gbproxy_cell *gbproxy_cell_by_bvci(struct gbproxy_config *cfg, uint16_t bvci) |
| { |
| struct gbproxy_cell *cell; |
| |
| hash_for_each_possible(cfg->cells, cell, list, bvci) { |
| if (cell->bvci == bvci) |
| return cell; |
| } |
| return NULL; |
| } |
| |
| struct gbproxy_cell *gbproxy_cell_by_bvci_or_new(struct gbproxy_config *cfg, uint16_t bvci) |
| { |
| struct gbproxy_cell *cell; |
| OSMO_ASSERT(cfg); |
| |
| cell = gbproxy_cell_by_bvci(cfg, bvci); |
| if (!cell) |
| cell = gbproxy_cell_alloc(cfg, bvci); |
| |
| return cell; |
| } |
| |
| void gbproxy_cell_free(struct gbproxy_cell *cell) |
| { |
| unsigned int i; |
| |
| if (!cell) |
| return; |
| |
| LOGPCELL_CAT(cell, DOBJ, LOGL_INFO, "CELL Destroying\n"); |
| |
| /* remove from cfg.cells */ |
| hash_del(&cell->list); |
| |
| /* remove back-pointers from the BSS side */ |
| if (cell->bss_bvc && cell->bss_bvc->cell) |
| cell->bss_bvc->cell = NULL; |
| |
| /* remove back-pointers from the SGSN side */ |
| for (i = 0; i < ARRAY_SIZE(cell->sgsn_bvc); i++) { |
| if (!cell->sgsn_bvc[i]) |
| continue; |
| if (cell->sgsn_bvc[i]->cell) |
| cell->sgsn_bvc[i]->cell = NULL; |
| } |
| |
| talloc_free(cell); |
| } |
| |
| bool gbproxy_cell_add_sgsn_bvc(struct gbproxy_cell *cell, struct gbproxy_bvc *bvc) |
| { |
| unsigned int i; |
| for (i = 0; i < ARRAY_SIZE(cell->sgsn_bvc); i++) { |
| if (!cell->sgsn_bvc[i]) { |
| cell->sgsn_bvc[i] = bvc; |
| LOGPCELL_CAT(cell, DOBJ, LOGL_DEBUG, "CELL linked to SGSN\n"); |
| LOGPBVC_CAT(bvc, DOBJ, LOGL_DEBUG, "BVC linked to CELL\n"); |
| return true; |
| } |
| } |
| return false; |
| } |
| |
| /*********************************************************************** |
| * NSE - NS Entity |
| ***********************************************************************/ |
| |
| struct gbproxy_nse *gbproxy_nse_alloc(struct gbproxy_config *cfg, uint16_t nsei, bool sgsn_facing) |
| { |
| struct gbproxy_nse *nse; |
| OSMO_ASSERT(cfg); |
| |
| nse = talloc_zero(tall_sgsn_ctx, struct gbproxy_nse); |
| if (!nse) |
| return NULL; |
| |
| nse->nsei = nsei; |
| nse->cfg = cfg; |
| nse->sgsn_facing = sgsn_facing; |
| |
| if (sgsn_facing) |
| hash_add(cfg->sgsn_nses, &nse->list, nsei); |
| else |
| hash_add(cfg->bss_nses, &nse->list, nsei); |
| |
| hash_init(nse->bvcs); |
| |
| LOGPNSE_CAT(nse, DOBJ, LOGL_INFO, "NSE Created\n"); |
| |
| return nse; |
| } |
| |
| static void _nse_free(struct gbproxy_nse *nse) |
| { |
| struct gbproxy_bvc *bvc; |
| struct hlist_node *tmp; |
| int i; |
| |
| if (!nse) |
| return; |
| |
| LOGPNSE_CAT(nse, DOBJ, LOGL_INFO, "NSE Destroying\n"); |
| |
| hash_del(&nse->list); |
| |
| hash_for_each_safe(nse->bvcs, i, tmp, bvc, list) |
| gbproxy_bvc_free(bvc); |
| |
| talloc_free(nse); |
| } |
| static void _sgsn_free(struct gbproxy_sgsn *sgsn); |
| |
| void gbproxy_nse_free(struct gbproxy_nse *nse) |
| { |
| if (!nse) |
| return; |
| OSMO_ASSERT(nse->cfg); |
| |
| if (nse->sgsn_facing) { |
| struct gbproxy_sgsn *sgsn = gbproxy_sgsn_by_nsei(nse->cfg, nse->nsei); |
| OSMO_ASSERT(sgsn); |
| _sgsn_free(sgsn); |
| } |
| |
| _nse_free(nse); |
| } |
| |
| struct gbproxy_nse *gbproxy_nse_by_nsei(struct gbproxy_config *cfg, uint16_t nsei, uint32_t flags) |
| { |
| struct gbproxy_nse *nse; |
| OSMO_ASSERT(cfg); |
| |
| if (flags & NSE_F_SGSN) { |
| hash_for_each_possible(cfg->sgsn_nses, nse, list, nsei) { |
| if (nse->nsei == nsei) |
| return nse; |
| } |
| } |
| |
| if (flags & NSE_F_BSS) { |
| hash_for_each_possible(cfg->bss_nses, nse, list, nsei) { |
| if (nse->nsei == nsei) |
| return nse; |
| } |
| } |
| |
| return NULL; |
| } |
| |
| struct gbproxy_nse *gbproxy_nse_by_nsei_or_new(struct gbproxy_config *cfg, uint16_t nsei, bool sgsn_facing) |
| { |
| struct gbproxy_nse *nse; |
| OSMO_ASSERT(cfg); |
| |
| nse = gbproxy_nse_by_nsei(cfg, nsei, sgsn_facing ? NSE_F_SGSN : NSE_F_BSS); |
| if (!nse) |
| nse = gbproxy_nse_alloc(cfg, nsei, sgsn_facing); |
| |
| return nse; |
| } |
| |
| /*********************************************************************** |
| * SGSN - Serving GPRS Support Node |
| ***********************************************************************/ |
| |
| /*! Allocate a new SGSN. This ensures the corresponding gbproxy_nse is allocated as well |
| * \param[in] cfg The gbproxy configuration |
| * \param[in] nsei The nsei where the SGSN can be reached |
| * \param[in] name A name to give the SGSN |
| * \return The SGSN, NULL if it couldn't be allocated |
| */ |
| struct gbproxy_sgsn *gbproxy_sgsn_alloc(struct gbproxy_config *cfg, uint16_t nsei, const char *name) |
| { |
| struct gbproxy_sgsn *sgsn; |
| OSMO_ASSERT(cfg); |
| |
| sgsn = talloc_zero(tall_sgsn_ctx, struct gbproxy_sgsn); |
| if (!sgsn) |
| return NULL; |
| |
| sgsn->nse = gbproxy_nse_alloc(cfg, nsei, true); |
| if (!sgsn->nse) { |
| LOGPSGSN_CAT(sgsn, DOBJ, LOGL_INFO, "Could not allocate NSE(%05u) for SGSN\n", nsei); |
| goto free_sgsn; |
| } |
| |
| if (name) |
| sgsn->name = talloc_strdup(sgsn, name); |
| else |
| sgsn->name = talloc_asprintf(sgsn, "NSE(%05u)", sgsn->nse->nsei); |
| if (!sgsn->name) |
| goto free_sgsn; |
| |
| sgsn->pool.allow_attach = true; |
| sgsn->pool.nri_ranges = osmo_nri_ranges_alloc(sgsn); |
| |
| llist_add_tail(&sgsn->list, &cfg->sgsns); |
| LOGPSGSN_CAT(sgsn, DOBJ, LOGL_INFO, "SGSN Created\n"); |
| return sgsn; |
| |
| free_sgsn: |
| talloc_free(sgsn); |
| return NULL; |
| } |
| |
| /* Only free gbproxy_sgsn, sgsn can't be NULL */ |
| static void _sgsn_free(struct gbproxy_sgsn *sgsn) { |
| struct gbproxy_config *cfg; |
| |
| OSMO_ASSERT(sgsn->nse); |
| cfg = sgsn->nse->cfg; |
| OSMO_ASSERT(cfg); |
| |
| LOGPSGSN_CAT(sgsn, DOBJ, LOGL_INFO, "SGSN Destroying\n"); |
| llist_del(&sgsn->list); |
| // talloc will free ->name and ->pool.nri_ranges |
| talloc_free(sgsn); |
| } |
| |
| /*! Free the SGSN. This ensures the corresponding gbproxy_nse is freed as well |
| * \param[in] sgsn The SGSN |
| */ |
| void gbproxy_sgsn_free(struct gbproxy_sgsn *sgsn) |
| { |
| if (!sgsn) |
| return; |
| |
| OSMO_ASSERT(sgsn->nse) |
| |
| _nse_free(sgsn->nse); |
| _sgsn_free(sgsn); |
| } |
| |
| /*! Return the SGSN for a given NSEI |
| * \param[in] cfg The gbproxy configuration |
| * \param[in] nsei The nsei where the SGSN can be reached |
| * \return Returns the matching SGSN or NULL if it couldn't be found |
| */ |
| struct gbproxy_sgsn *gbproxy_sgsn_by_name(struct gbproxy_config *cfg, const char *name) |
| { |
| struct gbproxy_sgsn *sgsn; |
| OSMO_ASSERT(cfg); |
| |
| llist_for_each_entry(sgsn, &cfg->sgsns, list) { |
| if (!strcmp(sgsn->name, name)) |
| return sgsn; |
| } |
| |
| return NULL; |
| } |
| |
| /*! Return the SGSN for a given NSEI |
| * \param[in] cfg The gbproxy configuration |
| * \param[in] nsei The nsei where the SGSN can be reached |
| * \return Returns the matching SGSN or NULL if it couldn't be found |
| */ |
| struct gbproxy_sgsn *gbproxy_sgsn_by_nsei(struct gbproxy_config *cfg, uint16_t nsei) |
| { |
| struct gbproxy_sgsn *sgsn; |
| OSMO_ASSERT(cfg); |
| |
| llist_for_each_entry(sgsn, &cfg->sgsns, list) { |
| if (sgsn->nse->nsei == nsei) |
| return sgsn; |
| } |
| |
| return NULL; |
| } |
| |
| /*! Return the SGSN for a given NSEI, creating a new one if none exists |
| * \param[in] cfg The gbproxy configuration |
| * \param[in] nsei The nsei where the SGSN can be reached |
| * \return Returns the SGSN |
| */ |
| struct gbproxy_sgsn *gbproxy_sgsn_by_nsei_or_new(struct gbproxy_config *cfg, uint16_t nsei) |
| { |
| struct gbproxy_sgsn *sgsn; |
| OSMO_ASSERT(cfg); |
| |
| sgsn = gbproxy_sgsn_by_nsei(cfg, nsei); |
| if (!sgsn) |
| sgsn = gbproxy_sgsn_alloc(cfg, nsei, NULL); |
| |
| return sgsn; |
| } |
| |
| /*! Return the gbproxy_sgsn matching that NRI |
| * \param[in] cfg proxy in which we operate |
| * \param[in] nri NRI to look for |
| * \param[out] null_nri If not NULL this indicates whether the NRI is a null NRI |
| * \return The SGSN this NRI has been added to, NULL if no matching SGSN could be found |
| */ |
| struct gbproxy_sgsn *gbproxy_sgsn_by_nri(struct gbproxy_config *cfg, uint16_t nri, bool *null_nri) |
| { |
| struct gbproxy_sgsn *sgsn; |
| OSMO_ASSERT(cfg); |
| |
| llist_for_each_entry(sgsn, &cfg->sgsns, list) { |
| if (osmo_nri_v_matches_ranges(nri, sgsn->pool.nri_ranges)) { |
| /* Also check if the NRI we're looking for is a NULL NRI */ |
| if (sgsn && null_nri) { |
| if (osmo_nri_v_matches_ranges(nri, cfg->pool.null_nri_ranges)) |
| *null_nri = true; |
| else |
| *null_nri = false; |
| } |
| return sgsn; |
| } |
| } |
| |
| return NULL; |
| } |
| |
| /*! Seleect a pseudo-random SGSN for a given TLLI, ignoring any SGSN that is not accepting connections |
| * \param[in] cfg The gbproxy configuration |
| * \param[in] sgsn_avoid If not NULL then avoid this SGSN when selecting a new one. Use for load redistribution |
| * \param[in] tlli The tlli to choose an SGSN for. The same tlli will map to the same SGSN as long as no SGSN is |
| * added/removed or allow_attach changes. |
| * \return Returns the sgsn on success, NULL if no SGSN that allows new connections could be found |
| */ |
| struct gbproxy_sgsn *gbproxy_sgsn_by_tlli(struct gbproxy_config *cfg, struct gbproxy_sgsn *sgsn_avoid, |
| uint32_t tlli) |
| { |
| uint32_t i = 0; |
| uint32_t index, num_sgsns; |
| OSMO_ASSERT(cfg); |
| |
| struct gbproxy_sgsn *sgsn = cfg->pool.nsf_override; |
| |
| if (sgsn) { |
| LOGPSGSN(sgsn, LOGL_DEBUG, "Node selection function is overridden by config\n"); |
| return sgsn; |
| } |
| |
| // TODO: We should keep track of count in cfg |
| num_sgsns = llist_count(&cfg->sgsns); |
| |
| if (num_sgsns == 0) |
| return NULL; |
| |
| // FIXME: 256 SGSNs ought to be enough for everyone |
| index = hash_32(tlli, 8) % num_sgsns; |
| |
| // Get the first enabled SGSN after index |
| llist_for_each_entry(sgsn, &cfg->sgsns, list) { |
| if (i >= index && sgsn->pool.allow_attach) { |
| return sgsn; |
| } |
| i++; |
| } |
| // Start again from the beginning |
| llist_for_each_entry(sgsn, &cfg->sgsns, list) { |
| if (i > index) { |
| break; |
| } else if (sgsn->pool.allow_attach) { |
| return sgsn; |
| } |
| i++; |
| } |
| |
| return NULL; |
| } |