Neels Hofmeyr | 76328bd | 2019-11-20 03:35:37 +0100 | [diff] [blame] | 1 | /* Copyright 2019 by sysmocom s.f.m.c. GmbH <info@sysmocom.de> |
| 2 | * |
| 3 | * All Rights Reserved |
| 4 | * |
| 5 | * This program is free software; you can redistribute it and/or modify |
| 6 | * it under the terms of the GNU Affero General Public License as published by |
| 7 | * the Free Software Foundation; either version 3 of the License, or |
| 8 | * (at your option) any later version. |
| 9 | * |
| 10 | * This program is distributed in the hope that it will be useful, |
| 11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 13 | * GNU Affero General Public License for more details. |
| 14 | * |
| 15 | * You should have received a copy of the GNU Affero General Public License |
| 16 | * along with this program. If not, see <http://www.gnu.org/licenses/>. |
| 17 | * |
| 18 | */ |
| 19 | |
| 20 | #include <osmocom/gsm/protocol/gsm_04_08_gprs.h> |
| 21 | #include <osmocom/gsm/gsup.h> |
| 22 | #include <osmocom/gsm/gsm23003.h> |
| 23 | #include <osmocom/abis/ipa.h> |
| 24 | #include <osmocom/gsupclient/gsup_client.h> |
| 25 | #include <osmocom/hlr/logging.h> |
| 26 | #include <osmocom/hlr/hlr.h> |
| 27 | #include <osmocom/hlr/gsup_server.h> |
| 28 | #include <osmocom/hlr/gsup_router.h> |
| 29 | #include <osmocom/hlr/remote_hlr.h> |
| 30 | #include <osmocom/hlr/proxy.h> |
| 31 | |
| 32 | static LLIST_HEAD(remote_hlrs); |
| 33 | |
| 34 | static void remote_hlr_err_reply(struct remote_hlr *rh, const struct osmo_gsup_message *gsup_orig, |
| 35 | enum gsm48_gmm_cause cause) |
| 36 | { |
| 37 | struct osmo_gsup_message gsup_reply; |
| 38 | |
| 39 | /* No need to answer if we couldn't parse an ERROR message type, only REQUESTs need an error reply. */ |
| 40 | if (!OSMO_GSUP_IS_MSGT_REQUEST(gsup_orig->message_type)) |
| 41 | return; |
| 42 | |
| 43 | gsup_reply = (struct osmo_gsup_message){ |
| 44 | .cause = cause, |
| 45 | .message_type = OSMO_GSUP_TO_MSGT_ERROR(gsup_orig->message_type), |
| 46 | .message_class = gsup_orig->message_class, |
| 47 | |
| 48 | /* RP-Message-Reference is mandatory for SM Service */ |
| 49 | .sm_rp_mr = gsup_orig->sm_rp_mr, |
| 50 | }; |
| 51 | |
| 52 | OSMO_STRLCPY_ARRAY(gsup_reply.imsi, gsup_orig->imsi); |
| 53 | |
| 54 | /* For SS/USSD, it's important to keep both session state and ID IEs */ |
| 55 | if (gsup_orig->session_state != OSMO_GSUP_SESSION_STATE_NONE) { |
| 56 | gsup_reply.session_state = OSMO_GSUP_SESSION_STATE_END; |
| 57 | gsup_reply.session_id = gsup_orig->session_id; |
| 58 | } |
| 59 | |
| 60 | if (osmo_gsup_client_enc_send(rh->gsupc, &gsup_reply)) |
| 61 | LOGP(DLGSUP, LOGL_ERROR, "Failed to send Error reply (imsi=%s)\n", |
| 62 | osmo_quote_str(gsup_orig->imsi, -1)); |
| 63 | } |
| 64 | |
| 65 | /* We are receiving a GSUP message from a remote HLR to go back to a local MSC. |
| 66 | * The local MSC shall be indicated by gsup.destination_name. */ |
| 67 | static int remote_hlr_rx(struct osmo_gsup_client *gsupc, struct msgb *msg) |
| 68 | { |
| 69 | struct remote_hlr *rh = gsupc->data; |
| 70 | struct proxy_subscr proxy_subscr; |
| 71 | struct osmo_gsup_message gsup; |
| 72 | int rc; |
| 73 | |
| 74 | rc = osmo_gsup_decode(msgb_l2(msg), msgb_l2len(msg), &gsup); |
| 75 | if (rc < 0) { |
| 76 | LOG_REMOTE_HLR(rh, LOGL_ERROR, "Failed to decode GSUP message: '%s' (%d) [ %s]\n", |
| 77 | get_value_string(gsm48_gmm_cause_names, -rc), |
| 78 | -rc, osmo_hexdump(msg->data, msg->len)); |
| 79 | return rc; |
| 80 | } |
| 81 | |
| 82 | if (!osmo_imsi_str_valid(gsup.imsi)) { |
| 83 | LOG_REMOTE_HLR_MSG(rh, &gsup, LOGL_ERROR, "Invalid IMSI\n"); |
| 84 | remote_hlr_err_reply(rh, &gsup, GMM_CAUSE_INV_MAND_INFO); |
| 85 | return -GMM_CAUSE_INV_MAND_INFO; |
| 86 | } |
| 87 | |
| 88 | if (proxy_subscr_get_by_imsi(&proxy_subscr, g_hlr->gs->proxy, gsup.imsi)) { |
| 89 | LOG_REMOTE_HLR_MSG(rh, &gsup, LOGL_ERROR, "No proxy entry for this IMSI\n"); |
| 90 | remote_hlr_err_reply(rh, &gsup, GMM_CAUSE_NET_FAIL); |
| 91 | return -GMM_CAUSE_NET_FAIL; |
| 92 | } |
| 93 | |
| 94 | rc = proxy_subscr_forward_to_vlr(g_hlr->gs->proxy, &proxy_subscr, &gsup, rh); |
| 95 | if (rc) { |
| 96 | LOG_REMOTE_HLR_MSG(rh, &gsup, LOGL_ERROR, "Failed to forward GSUP message towards VLR\n"); |
| 97 | remote_hlr_err_reply(rh, &gsup, GMM_CAUSE_NET_FAIL); |
| 98 | return -GMM_CAUSE_NET_FAIL; |
| 99 | } |
| 100 | return 0; |
| 101 | } |
| 102 | |
| 103 | struct remote_hlr_pending_up { |
| 104 | struct llist_head entry; |
| 105 | remote_hlr_connect_result_cb_t connect_result_cb; |
| 106 | void *data; |
| 107 | }; |
| 108 | |
| 109 | static bool remote_hlr_up_down(struct osmo_gsup_client *gsupc, bool up) |
| 110 | { |
| 111 | struct remote_hlr *remote_hlr = gsupc->data; |
| 112 | struct remote_hlr_pending_up *p, *n; |
| 113 | if (!up) { |
| 114 | LOG_REMOTE_HLR(remote_hlr, LOGL_NOTICE, "link to remote HLR is down, removing GSUP client\n"); |
| 115 | remote_hlr_destroy(remote_hlr); |
| 116 | return false; |
| 117 | } |
| 118 | |
| 119 | LOG_REMOTE_HLR(remote_hlr, LOGL_NOTICE, "link up\n"); |
| 120 | llist_for_each_entry_safe(p, n, &remote_hlr->pending_up_callbacks, entry) { |
| 121 | if (p->connect_result_cb) |
| 122 | p->connect_result_cb(&remote_hlr->addr, remote_hlr, p->data); |
| 123 | llist_del(&p->entry); |
| 124 | } |
| 125 | return true; |
| 126 | } |
| 127 | |
| 128 | bool remote_hlr_is_up(struct remote_hlr *remote_hlr) |
| 129 | { |
| 130 | return remote_hlr && remote_hlr->gsupc && remote_hlr->gsupc->is_connected; |
| 131 | } |
| 132 | |
| 133 | struct remote_hlr *remote_hlr_get_or_connect(const struct osmo_sockaddr_str *addr, bool connect, |
| 134 | remote_hlr_connect_result_cb_t connect_result_cb, void *data) |
| 135 | { |
| 136 | struct remote_hlr *rh = NULL; |
| 137 | struct remote_hlr *rh_i; |
| 138 | struct osmo_gsup_client_config cfg; |
| 139 | |
| 140 | llist_for_each_entry(rh_i, &remote_hlrs, entry) { |
| 141 | if (!osmo_sockaddr_str_cmp(&rh_i->addr, addr)) { |
| 142 | rh = rh_i; |
| 143 | break; |
| 144 | } |
| 145 | } |
| 146 | |
| 147 | if (rh) |
| 148 | goto add_result_cb; |
| 149 | |
| 150 | if (!connect) { |
| 151 | if (connect_result_cb) |
| 152 | connect_result_cb(addr, NULL, data); |
| 153 | return NULL; |
| 154 | } |
| 155 | |
| 156 | /* Doesn't exist yet, create a GSUP client to remote HLR. */ |
| 157 | cfg = (struct osmo_gsup_client_config){ |
| 158 | .ipa_dev = &g_hlr->gsup_unit_name, |
| 159 | .ip_addr = addr->ip, |
| 160 | .tcp_port = addr->port, |
| 161 | .oapc_config = NULL, |
| 162 | .read_cb = remote_hlr_rx, |
| 163 | .up_down_cb = remote_hlr_up_down, |
| 164 | .data = rh, |
| 165 | }; |
| 166 | rh = talloc_zero(dgsm_ctx, struct remote_hlr); |
| 167 | OSMO_ASSERT(rh); |
| 168 | *rh = (struct remote_hlr){ |
| 169 | .addr = *addr, |
| 170 | .gsupc = osmo_gsup_client_create3(rh, &cfg), |
| 171 | }; |
| 172 | INIT_LLIST_HEAD(&rh->pending_up_callbacks); |
| 173 | if (!rh->gsupc) { |
| 174 | LOGP(DDGSM, LOGL_ERROR, |
| 175 | "Failed to establish connection to remote HLR " OSMO_SOCKADDR_STR_FMT "\n", |
| 176 | OSMO_SOCKADDR_STR_FMT_ARGS(addr)); |
| 177 | talloc_free(rh); |
| 178 | if (connect_result_cb) |
| 179 | connect_result_cb(addr, NULL, data); |
| 180 | return NULL; |
| 181 | } |
| 182 | |
| 183 | rh->gsupc->data = rh; |
| 184 | llist_add(&rh->entry, &remote_hlrs); |
| 185 | |
| 186 | add_result_cb: |
| 187 | if (connect_result_cb) { |
| 188 | if (remote_hlr_is_up(rh)) { |
| 189 | connect_result_cb(addr, rh, data); |
| 190 | } else { |
| 191 | struct remote_hlr_pending_up *p; |
| 192 | p = talloc_zero(rh, struct remote_hlr_pending_up); |
| 193 | OSMO_ASSERT(p); |
| 194 | p->connect_result_cb = connect_result_cb; |
| 195 | p->data = data; |
| 196 | llist_add_tail(&p->entry, &rh->pending_up_callbacks); |
| 197 | } |
| 198 | } |
| 199 | return rh; |
| 200 | } |
| 201 | |
| 202 | void remote_hlr_destroy(struct remote_hlr *remote_hlr) |
| 203 | { |
| 204 | osmo_gsup_client_destroy(remote_hlr->gsupc); |
| 205 | remote_hlr->gsupc = NULL; |
| 206 | llist_del(&remote_hlr->entry); |
| 207 | talloc_free(remote_hlr); |
| 208 | } |
| 209 | |
| 210 | /* This function takes ownership of the msg, do not free it after passing to this function. */ |
| 211 | int remote_hlr_msgb_send(struct remote_hlr *remote_hlr, struct msgb *msg) |
| 212 | { |
| 213 | int rc = osmo_gsup_client_send(remote_hlr->gsupc, msg); |
| 214 | if (rc) { |
| 215 | LOGP(DDGSM, LOGL_ERROR, "Failed to send GSUP message to " OSMO_SOCKADDR_STR_FMT "\n", |
| 216 | OSMO_SOCKADDR_STR_FMT_ARGS(&remote_hlr->addr)); |
| 217 | } |
| 218 | return rc; |
| 219 | } |
| 220 | |
| 221 | /* A GSUP message was received from the MS/MSC side, forward it to the remote HLR. */ |
| 222 | void remote_hlr_gsup_forward_to_remote_hlr(struct remote_hlr *remote_hlr, struct osmo_gsup_req *req, |
| 223 | struct osmo_gsup_message *modified_gsup) |
| 224 | { |
| 225 | int rc; |
| 226 | struct msgb *msg; |
| 227 | /* To forward to a remote HLR, we need to indicate the source MSC's name in the Source Name IE to make sure the |
| 228 | * reply can be routed back. Store the sender MSC in gsup->source_name -- the remote HLR is required to return |
| 229 | * this as gsup->destination_name so that the reply gets routed to the original MSC. */ |
| 230 | struct osmo_gsup_message forward; |
| 231 | if (modified_gsup) |
| 232 | forward = *modified_gsup; |
| 233 | else |
| 234 | forward = req->gsup; |
| 235 | |
| 236 | if (req->source_name.type != OSMO_CNI_PEER_ID_IPA_NAME) { |
| 237 | osmo_gsup_req_respond_err(req, GMM_CAUSE_NET_FAIL, "Unsupported GSUP peer id type: %s", |
| 238 | osmo_cni_peer_id_type_name(req->source_name.type)); |
| 239 | return; |
| 240 | } |
| 241 | forward.source_name = req->source_name.ipa_name.val; |
| 242 | forward.source_name_len = req->source_name.ipa_name.len; |
| 243 | |
| 244 | msg = osmo_gsup_msgb_alloc("GSUP proxy to remote HLR"); |
| 245 | rc = osmo_gsup_encode(msg, &forward); |
| 246 | if (rc) { |
| 247 | osmo_gsup_req_respond_err(req, GMM_CAUSE_NET_FAIL, "Failed to encode GSUP message for forwarding"); |
| 248 | return; |
| 249 | } |
| 250 | remote_hlr_msgb_send(remote_hlr, msg); |
| 251 | osmo_gsup_req_free(req); |
| 252 | } |