Neels Hofmeyr | 7299215 | 2020-09-19 02:36:08 +0200 | [diff] [blame] | 1 | /* |
| 2 | * (C) 2020 by sysmocom - s.m.f.c. GmbH <info@sysmocom.de> |
| 3 | * All Rights Reserved |
| 4 | * |
| 5 | * SPDX-License-Identifier: AGPL-3.0+ |
| 6 | * |
| 7 | * Author: Neels Hofmeyr |
| 8 | * |
| 9 | * This program is free software; you can redistribute it and/or modify |
| 10 | * it under the terms of the GNU Affero General Public License as published by |
| 11 | * the Free Software Foundation; either version 3 of the License, or |
| 12 | * (at your option) any later version. |
| 13 | * |
| 14 | * This program is distributed in the hope that it will be useful, |
| 15 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 16 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 17 | * GNU Affero General Public License for more details. |
| 18 | * |
| 19 | * You should have received a copy of the GNU Affero General Public License |
| 20 | * along with this program. If not, see <http://www.gnu.org/licenses/>. |
| 21 | */ |
| 22 | |
| 23 | #include <osmocom/core/logging.h> |
| 24 | |
| 25 | #include <osmocom/sccp/sccp_types.h> |
| 26 | #include <osmocom/sigtran/sccp_sap.h> |
| 27 | #include <osmocom/sigtran/sccp_helpers.h> |
| 28 | |
| 29 | #include <osmocom/smlc/debug.h> |
| 30 | #include <osmocom/smlc/smlc_data.h> |
| 31 | #include <osmocom/smlc/sccp_lb_inst.h> |
| 32 | #include <osmocom/smlc/lb_peer.h> |
| 33 | |
| 34 | /* We need an unused SCCP conn_id across all SCCP users. */ |
| 35 | int sccp_lb_inst_next_conn_id() |
| 36 | { |
| 37 | static uint32_t next_id = 1; |
| 38 | int i; |
| 39 | |
| 40 | /* This looks really suboptimal, but in most cases the static next_id should indicate exactly the next unused |
| 41 | * conn_id, and we only iterate all conns once to make super sure that it is not already in use. */ |
| 42 | |
| 43 | for (i = 0; i < 0xFFFFFF; i++) { |
| 44 | struct lb_peer *lb_peer; |
| 45 | uint32_t conn_id = next_id; |
| 46 | bool conn_id_already_used = false; |
| 47 | next_id = (next_id + 1) & 0xffffff; |
| 48 | |
| 49 | llist_for_each_entry(lb_peer, &g_smlc->lb->lb_peers, entry) { |
| 50 | struct lb_conn *conn; |
| 51 | lb_peer_for_each_lb_conn(conn, lb_peer) { |
| 52 | if (conn_id == conn->sccp_conn_id) { |
| 53 | conn_id_already_used = true; |
| 54 | break; |
| 55 | } |
| 56 | } |
| 57 | if (conn_id_already_used) |
| 58 | break; |
| 59 | } |
| 60 | |
| 61 | if (!conn_id_already_used) |
| 62 | return conn_id; |
| 63 | } |
| 64 | return -1; |
| 65 | } |
| 66 | |
| 67 | static int sccp_lb_sap_up(struct osmo_prim_hdr *oph, void *_scu); |
| 68 | |
| 69 | struct sccp_lb_inst *sccp_lb_init(void *talloc_ctx, struct osmo_sccp_instance *sccp, enum osmo_sccp_ssn ssn, |
| 70 | const char *sccp_user_name) |
| 71 | { |
| 72 | struct sccp_lb_inst *sli = talloc(talloc_ctx, struct sccp_lb_inst); |
| 73 | OSMO_ASSERT(sli); |
| 74 | *sli = (struct sccp_lb_inst){ |
| 75 | .sccp = sccp, |
| 76 | }; |
| 77 | |
| 78 | INIT_LLIST_HEAD(&sli->lb_peers); |
| 79 | INIT_LLIST_HEAD(&sli->lb_conns); |
| 80 | |
| 81 | osmo_sccp_local_addr_by_instance(&sli->local_sccp_addr, sccp, ssn); |
| 82 | sli->scu = osmo_sccp_user_bind(sccp, sccp_user_name, sccp_lb_sap_up, ssn); |
| 83 | osmo_sccp_user_set_priv(sli->scu, sli); |
| 84 | |
| 85 | return sli; |
| 86 | } |
| 87 | |
| 88 | static int sccp_lb_sap_up(struct osmo_prim_hdr *oph, void *_scu) |
| 89 | { |
| 90 | struct osmo_sccp_user *scu = _scu; |
| 91 | struct sccp_lb_inst *sli = osmo_sccp_user_get_priv(scu); |
| 92 | struct osmo_scu_prim *prim = (struct osmo_scu_prim *) oph; |
| 93 | struct osmo_sccp_addr *my_addr; |
| 94 | struct osmo_sccp_addr *peer_addr; |
| 95 | uint32_t conn_id; |
| 96 | int rc; |
| 97 | |
| 98 | switch (OSMO_PRIM_HDR(oph)) { |
| 99 | case OSMO_PRIM(OSMO_SCU_PRIM_N_CONNECT, PRIM_OP_INDICATION): |
| 100 | /* indication of new inbound connection request */ |
| 101 | conn_id = prim->u.connect.conn_id; |
| 102 | my_addr = &prim->u.connect.called_addr; |
| 103 | peer_addr = &prim->u.connect.calling_addr; |
| 104 | LOG_SCCP_LB_CO(sli, peer_addr, conn_id, LOGL_DEBUG, "%s(%s)\n", __func__, osmo_scu_prim_name(oph)); |
| 105 | |
| 106 | if (!msgb_l2(oph->msg) || msgb_l2len(oph->msg) == 0) { |
| 107 | LOG_SCCP_LB_CO(sli, peer_addr, conn_id, LOGL_NOTICE, "Received invalid N-CONNECT.ind\n"); |
| 108 | rc = -1; |
| 109 | break; |
| 110 | } |
| 111 | |
| 112 | if (osmo_sccp_addr_ri_cmp(&sli->local_sccp_addr, my_addr)) |
| 113 | LOG_SCCP_LB_CO(sli, peer_addr, conn_id, LOGL_ERROR, |
| 114 | "Rx N-CONNECT: Called address is %s != local address %s\n", |
| 115 | osmo_sccp_inst_addr_to_str_c(OTC_SELECT, sli->sccp, my_addr), |
| 116 | osmo_sccp_inst_addr_to_str_c(OTC_SELECT, sli->sccp, &sli->local_sccp_addr)); |
| 117 | |
| 118 | /* ensure the local SCCP socket is ACTIVE */ |
| 119 | osmo_sccp_tx_conn_resp(scu, conn_id, my_addr, NULL, 0); |
| 120 | |
| 121 | rc = lb_peer_up_l2(sli, peer_addr, true, conn_id, oph->msg); |
| 122 | if (rc) |
| 123 | osmo_sccp_tx_disconn(scu, conn_id, my_addr, SCCP_RETURN_CAUSE_UNQUALIFIED); |
| 124 | break; |
| 125 | |
| 126 | case OSMO_PRIM(OSMO_SCU_PRIM_N_DATA, PRIM_OP_INDICATION): |
| 127 | /* connection-oriented data received */ |
| 128 | conn_id = prim->u.data.conn_id; |
| 129 | LOG_SCCP_LB_CO(sli, NULL, conn_id, LOGL_DEBUG, "%s(%s)\n", __func__, osmo_scu_prim_name(oph)); |
| 130 | |
| 131 | rc = lb_peer_up_l2(sli, NULL, true, conn_id, oph->msg); |
| 132 | break; |
| 133 | |
| 134 | case OSMO_PRIM(OSMO_SCU_PRIM_N_DISCONNECT, PRIM_OP_INDICATION): |
| 135 | /* indication of disconnect */ |
| 136 | conn_id = prim->u.disconnect.conn_id; |
| 137 | LOG_SCCP_LB_CO(sli, NULL, conn_id, LOGL_DEBUG, "%s(%s)\n", __func__, osmo_scu_prim_name(oph)); |
| 138 | |
| 139 | /* If there is no L2 payload in the N-DISCONNECT, no need to dispatch up_l2(). */ |
| 140 | if (msgb_l2len(oph->msg)) |
| 141 | rc = lb_peer_up_l2(sli, NULL, true, conn_id, oph->msg); |
| 142 | else |
| 143 | rc = 0; |
| 144 | |
| 145 | /* Make sure the lb_conn is dropped. It might seem more optimal to combine the disconnect() into |
| 146 | * up_l2(), but since an up_l2() dispatch might already cause the lb_conn to be discarded for other |
| 147 | * reasons, a separate disconnect() with a separate conn_id lookup is actually necessary. */ |
| 148 | sccp_lb_disconnect(sli, conn_id, 0); |
| 149 | break; |
| 150 | |
| 151 | case OSMO_PRIM(OSMO_SCU_PRIM_N_UNITDATA, PRIM_OP_INDICATION): |
| 152 | /* connection-less data received */ |
| 153 | my_addr = &prim->u.unitdata.called_addr; |
| 154 | peer_addr = &prim->u.unitdata.calling_addr; |
| 155 | LOG_SCCP_LB_CL(sli, peer_addr, LOGL_DEBUG, "%s(%s)\n", __func__, osmo_scu_prim_name(oph)); |
| 156 | |
| 157 | if (osmo_sccp_addr_ri_cmp(&sli->local_sccp_addr, my_addr)) |
| 158 | LOG_SCCP_LB_CL(sli, peer_addr, LOGL_ERROR, |
| 159 | "Rx N-UNITDATA: Called address is %s != local address %s\n", |
| 160 | osmo_sccp_inst_addr_to_str_c(OTC_SELECT, sli->sccp, my_addr), |
| 161 | osmo_sccp_inst_addr_to_str_c(OTC_SELECT, sli->sccp, &sli->local_sccp_addr)); |
| 162 | |
| 163 | rc = lb_peer_up_l2(sli, peer_addr, false, 0, oph->msg); |
| 164 | break; |
| 165 | |
| 166 | default: |
| 167 | LOG_SCCP_LB_CL(sli, NULL, LOGL_ERROR, "%s(%s) unsupported\n", __func__, osmo_scu_prim_name(oph)); |
| 168 | rc = -1; |
| 169 | break; |
| 170 | } |
| 171 | |
| 172 | msgb_free(oph->msg); |
| 173 | return rc; |
| 174 | } |
| 175 | |
| 176 | /* Push some padding if necessary to reach a multiple-of-eight offset to be msgb_push() an osmo_scu_prim that will then |
| 177 | * be 8-byte aligned. */ |
| 178 | static void msgb_pad_mod8(struct msgb *msg) |
| 179 | { |
| 180 | uint8_t mod8 = (intptr_t)(msg->data) % 8; |
| 181 | if (mod8) |
| 182 | msgb_push(msg, mod8); |
| 183 | } |
| 184 | |
| 185 | static int sccp_lb_sap_down(struct sccp_lb_inst *sli, struct osmo_prim_hdr *oph) |
| 186 | { |
| 187 | int rc; |
| 188 | if (!sli->scu) { |
Pau Espin Pedrol | 44a2a85 | 2021-06-04 18:07:05 +0200 | [diff] [blame^] | 189 | rate_ctr_inc(rate_ctr_group_get_ctr(g_smlc->ctrs, SMLC_CTR_BSSMAP_LE_TX_ERR_CONN_NOT_READY)); |
Neels Hofmeyr | 7299215 | 2020-09-19 02:36:08 +0200 | [diff] [blame] | 190 | return -EIO; |
| 191 | } |
| 192 | rc = osmo_sccp_user_sap_down_nofree(sli->scu, oph); |
| 193 | if (rc >= 0) |
Pau Espin Pedrol | 44a2a85 | 2021-06-04 18:07:05 +0200 | [diff] [blame^] | 194 | rate_ctr_inc(rate_ctr_group_get_ctr(g_smlc->ctrs, SMLC_CTR_BSSMAP_LE_TX_SUCCESS)); |
Neels Hofmeyr | 7299215 | 2020-09-19 02:36:08 +0200 | [diff] [blame] | 195 | else |
Pau Espin Pedrol | 44a2a85 | 2021-06-04 18:07:05 +0200 | [diff] [blame^] | 196 | rate_ctr_inc(rate_ctr_group_get_ctr(g_smlc->ctrs, SMLC_CTR_BSSMAP_LE_TX_ERR_SEND)); |
Neels Hofmeyr | 7299215 | 2020-09-19 02:36:08 +0200 | [diff] [blame] | 197 | return rc; |
| 198 | } |
| 199 | |
| 200 | int sccp_lb_down_l2_co_initial(struct sccp_lb_inst *sli, |
| 201 | const struct osmo_sccp_addr *called_addr, |
| 202 | uint32_t conn_id, struct msgb *l2) |
| 203 | { |
| 204 | struct osmo_scu_prim *prim; |
| 205 | |
| 206 | l2->l2h = l2->data; |
| 207 | |
| 208 | msgb_pad_mod8(l2); |
| 209 | prim = (struct osmo_scu_prim *) msgb_push(l2, sizeof(*prim)); |
| 210 | prim->u.connect = (struct osmo_scu_connect_param){ |
| 211 | .called_addr = *called_addr, |
| 212 | .calling_addr = sli->local_sccp_addr, |
| 213 | .sccp_class = 2, |
| 214 | //.importance = ?, |
| 215 | .conn_id = conn_id, |
| 216 | }; |
| 217 | osmo_prim_init(&prim->oph, SCCP_SAP_USER, OSMO_SCU_PRIM_N_CONNECT, PRIM_OP_REQUEST, l2); |
| 218 | return sccp_lb_sap_down(sli, &prim->oph); |
| 219 | } |
| 220 | |
| 221 | int sccp_lb_down_l2_co(struct sccp_lb_inst *sli, uint32_t conn_id, struct msgb *l2) |
| 222 | { |
| 223 | struct osmo_scu_prim *prim; |
| 224 | |
| 225 | l2->l2h = l2->data; |
| 226 | |
| 227 | msgb_pad_mod8(l2); |
| 228 | prim = (struct osmo_scu_prim *) msgb_push(l2, sizeof(*prim)); |
| 229 | prim->u.data.conn_id = conn_id; |
| 230 | osmo_prim_init(&prim->oph, SCCP_SAP_USER, OSMO_SCU_PRIM_N_DATA, PRIM_OP_REQUEST, l2); |
| 231 | return sccp_lb_sap_down(sli, &prim->oph); |
| 232 | } |
| 233 | |
| 234 | int sccp_lb_down_l2_cl(struct sccp_lb_inst *sli, const struct osmo_sccp_addr *called_addr, struct msgb *l2) |
| 235 | { |
| 236 | struct osmo_scu_prim *prim; |
| 237 | |
| 238 | l2->l2h = l2->data; |
| 239 | |
| 240 | msgb_pad_mod8(l2); |
| 241 | prim = (struct osmo_scu_prim *) msgb_push(l2, sizeof(*prim)); |
| 242 | prim->u.unitdata = (struct osmo_scu_unitdata_param){ |
| 243 | .called_addr = *called_addr, |
| 244 | .calling_addr = sli->local_sccp_addr, |
| 245 | }; |
| 246 | osmo_prim_init(&prim->oph, SCCP_SAP_USER, OSMO_SCU_PRIM_N_UNITDATA, PRIM_OP_REQUEST, l2); |
| 247 | return sccp_lb_sap_down(sli, &prim->oph); |
| 248 | } |
| 249 | |
| 250 | int sccp_lb_disconnect(struct sccp_lb_inst *sli, uint32_t conn_id, uint32_t cause) |
| 251 | { |
| 252 | return osmo_sccp_tx_disconn(sli->scu, conn_id, NULL, cause); |
| 253 | } |