D-GSM 1/n: add mslookup server in osmo-hlr

Implement the mslookup server to service remote mslookup requests.

This patch merely adds the logic to answer incoming mslookup requests, an
actual method to receive requests (mDNS) follows in a subsequent patch.

- API to configure service names and addresses for the local site (per MSC).
- determine whether a subscriber is on a local MSC
  (checking the local proxy will be added in subsequent patch that adds proxy
  capability).
- VTY config follows in a subsequent patch.

For a detailed overview of the D-GSM and mslookup related files, please see the
elaborate comment at the top of mslookup.c (already added in an earlier patch).

Change-Id: Ife4a61d71926d08f310a1aeed9d9f1974f64178b
This commit is contained in:
Neels Hofmeyr 2019-11-20 03:35:37 +01:00
parent 86b507b6ea
commit ab7dc40f16
8 changed files with 537 additions and 0 deletions

View File

@ -10,5 +10,7 @@ noinst_HEADERS = \
hlr_vty_subscr.h \
logging.h \
lu_fsm.h \
mslookup_server.h \
rand.h \
timestamp.h \
$(NULL)

View File

@ -67,6 +67,13 @@ struct hlr {
/* Bitmask of DB_SUBSCR_FLAG_* */
uint8_t subscr_create_on_demand_flags;
unsigned int subscr_create_on_demand_rand_msisdn_len;
struct {
struct {
uint32_t local_attach_max_age;
struct llist_head local_site_services;
} server;
} mslookup;
};
extern struct hlr *g_hlr;

View File

@ -0,0 +1,65 @@
/* Copyright 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/>.
*
*/
#pragma once
struct osmo_mslookup_query;
struct osmo_mslookup_result;
/*! mslookup service name used for roaming/proxying between osmo-hlr instances. */
#define OSMO_MSLOOKUP_SERVICE_HLR_GSUP "gsup.hlr"
/*! What addresses to return to mslookup queries when a subscriber is attached at the local site.
* Mapping of service name to IP address and port. This corresponds to the VTY config for
* 'mslookup' / 'server' [/ 'msc MSC-1-2-3'] / 'service sip.voice at 1.2.3.4 1234'.
*/
struct mslookup_service_host {
struct llist_head entry;
char service[OSMO_MSLOOKUP_SERVICE_MAXLEN+1];
struct osmo_sockaddr_str host_v4;
struct osmo_sockaddr_str host_v6;
};
/*! Sets of mslookup_service_host per connected MSC.
* When there are more than one MSC connected to this osmo-hlr, this allows keeping separate sets of service addresses
* for each MSC. The entry with mslookup_server_msc_wildcard as MSC name is used for all MSCs (if no match for that
* particular MSC is found). This corresponds to the VTY config for
* 'mslookup' / 'server' / 'msc MSC-1-2-3'.
*/
struct mslookup_server_msc_cfg {
struct llist_head entry;
struct osmo_ipa_name name;
struct llist_head service_hosts;
};
struct mslookup_service_host *mslookup_server_service_get(const struct osmo_ipa_name *msc_name, const char *service);
struct mslookup_service_host *mslookup_server_msc_service_get(struct mslookup_server_msc_cfg *msc, const char *service,
bool create);
int mslookup_server_msc_service_set(struct mslookup_server_msc_cfg *msc, const char *service,
const struct osmo_sockaddr_str *addr);
int mslookup_server_msc_service_del(struct mslookup_server_msc_cfg *msc, const char *service,
const struct osmo_sockaddr_str *addr);
extern const struct osmo_ipa_name mslookup_server_msc_wildcard;
struct mslookup_server_msc_cfg *mslookup_server_msc_get(const struct osmo_ipa_name *msc_name, bool create);
const struct mslookup_service_host *mslookup_server_get_local_gsup_addr();
void mslookup_server_rx(const struct osmo_mslookup_query *query,
struct osmo_mslookup_result *result);

View File

@ -0,0 +1,28 @@
/* Copyright 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/>.
*
*/
#pragma once
#include <sys/time.h>
#include <stdbool.h>
#include <stdint.h>
typedef time_t timestamp_t;
void timestamp_update(timestamp_t *timestamp);
bool timestamp_age(const timestamp_t *timestamp, uint32_t *age);

View File

@ -9,6 +9,7 @@ AM_CFLAGS = \
$(LIBOSMOGSM_CFLAGS) \
$(LIBOSMOVTY_CFLAGS) \
$(LIBOSMOCTRL_CFLAGS) \
$(LIBOSMOMSLOOKUP_CFLAGS) \
$(LIBOSMOABIS_CFLAGS) \
$(SQLITE3_CFLAGS) \
$(NULL)
@ -53,14 +54,18 @@ osmo_hlr_SOURCES = \
gsup_send.c \
hlr_ussd.c \
lu_fsm.c \
mslookup_server.c \
timestamp.c \
$(NULL)
osmo_hlr_LDADD = \
$(top_builddir)/src/gsupclient/libosmo-gsup-client.la \
$(top_builddir)/src/mslookup/libosmo-mslookup.la \
$(LIBOSMOCORE_LIBS) \
$(LIBOSMOGSM_LIBS) \
$(LIBOSMOVTY_LIBS) \
$(LIBOSMOCTRL_LIBS) \
$(LIBOSMOMSLOOKUP_LIBS) \
$(LIBOSMOABIS_LIBS) \
$(SQLITE3_LIBS) \
$(NULL)

View File

@ -695,6 +695,7 @@ int main(int argc, char **argv)
INIT_LLIST_HEAD(&g_hlr->euse_list);
INIT_LLIST_HEAD(&g_hlr->ss_sessions);
INIT_LLIST_HEAD(&g_hlr->ussd_routes);
INIT_LLIST_HEAD(&g_hlr->mslookup.server.local_site_services);
g_hlr->db_file_path = talloc_strdup(g_hlr, HLR_DEFAULT_DB_FILE_PATH);
/* Init default (call independent) SS session guard timeout value */

376
src/mslookup_server.c Normal file
View File

@ -0,0 +1,376 @@
/* Copyright 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 <string.h>
#include <errno.h>
#include <osmocom/core/sockaddr_str.h>
#include <osmocom/gsm/gsup.h>
#include <osmocom/mslookup/mslookup.h>
#include <osmocom/hlr/logging.h>
#include <osmocom/hlr/hlr.h>
#include <osmocom/hlr/db.h>
#include <osmocom/hlr/timestamp.h>
#include <osmocom/hlr/mslookup_server.h>
static const struct osmo_mslookup_result not_found = {
.rc = OSMO_MSLOOKUP_RC_NOT_FOUND,
};
const struct osmo_ipa_name mslookup_server_msc_wildcard = {};
static void set_result(struct osmo_mslookup_result *result,
const struct mslookup_service_host *service_host,
uint32_t age)
{
if (!osmo_sockaddr_str_is_nonzero(&service_host->host_v4)
&& !osmo_sockaddr_str_is_nonzero(&service_host->host_v6)) {
*result = not_found;
return;
}
result->rc = OSMO_MSLOOKUP_RC_RESULT;
result->host_v4 = service_host->host_v4;
result->host_v6 = service_host->host_v6;
result->age = age;
}
const struct mslookup_service_host *mslookup_server_get_local_gsup_addr()
{
static struct mslookup_service_host gsup_bind = {};
struct mslookup_service_host *host;
/* Find a HLR/GSUP service set for the server (no VLR unit name) */
host = mslookup_server_service_get(&mslookup_server_msc_wildcard, OSMO_MSLOOKUP_SERVICE_HLR_GSUP);
if (host)
return host;
/* Try to use the locally configured GSUP bind address */
osmo_sockaddr_str_from_str(&gsup_bind.host_v4, g_hlr->gsup_bind_addr, OSMO_GSUP_PORT);
if (gsup_bind.host_v4.af == AF_INET6) {
gsup_bind.host_v6 = gsup_bind.host_v4;
gsup_bind.host_v4 = (struct osmo_sockaddr_str){};
}
return &gsup_bind;
}
struct mslookup_server_msc_cfg *mslookup_server_msc_get(const struct osmo_ipa_name *msc_name, bool create)
{
struct llist_head *c = &g_hlr->mslookup.server.local_site_services;
struct mslookup_server_msc_cfg *msc;
if (!msc_name)
return NULL;
llist_for_each_entry(msc, c, entry) {
if (osmo_ipa_name_cmp(&msc->name, msc_name))
continue;
return msc;
}
if (!create)
return NULL;
msc = talloc_zero(g_hlr, struct mslookup_server_msc_cfg);
OSMO_ASSERT(msc);
INIT_LLIST_HEAD(&msc->service_hosts);
msc->name = *msc_name;
llist_add_tail(&msc->entry, c);
return msc;
}
struct mslookup_service_host *mslookup_server_msc_service_get(struct mslookup_server_msc_cfg *msc, const char *service,
bool create)
{
struct mslookup_service_host *e;
if (!msc)
return NULL;
llist_for_each_entry(e, &msc->service_hosts, entry) {
if (!strcmp(e->service, service))
return e;
}
if (!create)
return NULL;
e = talloc_zero(msc, struct mslookup_service_host);
OSMO_ASSERT(e);
OSMO_STRLCPY_ARRAY(e->service, service);
llist_add_tail(&e->entry, &msc->service_hosts);
return e;
}
struct mslookup_service_host *mslookup_server_service_get(const struct osmo_ipa_name *msc_name, const char *service)
{
struct mslookup_server_msc_cfg *msc = mslookup_server_msc_get(msc_name, false);
if (!msc)
return NULL;
return mslookup_server_msc_service_get(msc, service, false);
}
int mslookup_server_msc_service_set(struct mslookup_server_msc_cfg *msc, const char *service,
const struct osmo_sockaddr_str *addr)
{
struct mslookup_service_host *e;
if (!service || !service[0]
|| strlen(service) > OSMO_MSLOOKUP_SERVICE_MAXLEN)
return -EINVAL;
if (!addr || !osmo_sockaddr_str_is_nonzero(addr))
return -EINVAL;
e = mslookup_server_msc_service_get(msc, service, true);
if (!e)
return -EINVAL;
switch (addr->af) {
case AF_INET:
e->host_v4 = *addr;
break;
case AF_INET6:
e->host_v6 = *addr;
break;
default:
return -EINVAL;
}
return 0;
}
int mslookup_server_msc_service_del(struct mslookup_server_msc_cfg *msc, const char *service,
const struct osmo_sockaddr_str *addr)
{
struct mslookup_service_host *e, *n;
int deleted = 0;
if (!msc)
return -ENOENT;
llist_for_each_entry_safe(e, n, &msc->service_hosts, entry) {
if (service && strcmp(service, e->service))
continue;
if (addr) {
if (!osmo_sockaddr_str_cmp(addr, &e->host_v4)) {
e->host_v4 = (struct osmo_sockaddr_str){};
/* Removed one addr. If the other is still there, keep the entry. */
if (osmo_sockaddr_str_is_nonzero(&e->host_v6))
continue;
} else if (!osmo_sockaddr_str_cmp(addr, &e->host_v6)) {
e->host_v6 = (struct osmo_sockaddr_str){};
/* Removed one addr. If the other is still there, keep the entry. */
if (osmo_sockaddr_str_is_nonzero(&e->host_v4))
continue;
} else
/* No addr match, keep the entry. */
continue;
/* Addr matched and none is left. Delete. */
}
llist_del(&e->entry);
talloc_free(e);
deleted++;
}
return deleted;
}
/* A remote entity is asking us whether we are the home HLR of the given subscriber. */
static void mslookup_server_rx_hlr_gsup(const struct osmo_mslookup_query *query,
struct osmo_mslookup_result *result)
{
const struct mslookup_service_host *host;
int rc;
switch (query->id.type) {
case OSMO_MSLOOKUP_ID_IMSI:
rc = db_subscr_exists_by_imsi(g_hlr->dbc, query->id.imsi);
break;
case OSMO_MSLOOKUP_ID_MSISDN:
rc = db_subscr_exists_by_msisdn(g_hlr->dbc, query->id.msisdn);
break;
default:
LOGP(DMSLOOKUP, LOGL_ERROR, "Unknown mslookup ID type: %d\n", query->id.type);
*result = not_found;
return;
}
if (rc) {
LOGP(DMSLOOKUP, LOGL_DEBUG, "%s: does not exist in local HLR\n",
osmo_mslookup_result_name_c(OTC_SELECT, query, NULL));
*result = not_found;
return;
}
LOGP(DMSLOOKUP, LOGL_DEBUG, "%s: found in local HLR\n",
osmo_mslookup_result_name_c(OTC_SELECT, query, NULL));
host = mslookup_server_get_local_gsup_addr();
set_result(result, host, 0);
if (result->rc != OSMO_MSLOOKUP_RC_RESULT) {
LOGP(DMSLOOKUP, LOGL_ERROR,
"Subscriber found, but error in service '" OSMO_MSLOOKUP_SERVICE_HLR_GSUP "' config:"
" v4: " OSMO_SOCKADDR_STR_FMT " v6: " OSMO_SOCKADDR_STR_FMT "\n",
OSMO_SOCKADDR_STR_FMT_ARGS(&host->host_v4),
OSMO_SOCKADDR_STR_FMT_ARGS(&host->host_v6));
}
}
/* Look in the local HLR record: If the subscriber is "at home" in this HLR and is also currently located at a local
* VLR, we will find a valid location updating with vlr_number, and no vlr_via_proxy entry. */
static bool subscriber_has_done_lu_here_hlr(const struct osmo_mslookup_query *query,
uint32_t *lu_age,
struct osmo_ipa_name *local_msc_name,
struct hlr_subscriber *ret_subscr)
{
struct hlr_subscriber _subscr;
int rc;
uint32_t age;
struct hlr_subscriber *subscr = ret_subscr ? : &_subscr;
switch (query->id.type) {
case OSMO_MSLOOKUP_ID_IMSI:
rc = db_subscr_get_by_imsi(g_hlr->dbc, query->id.imsi, subscr);
break;
case OSMO_MSLOOKUP_ID_MSISDN:
rc = db_subscr_get_by_msisdn(g_hlr->dbc, query->id.msisdn, subscr);
break;
default:
LOGP(DMSLOOKUP, LOGL_ERROR, "Unknown mslookup ID type: %d\n", query->id.type);
return false;
}
if (rc) {
LOGP(DMSLOOKUP, LOGL_DEBUG, "%s: does not exist in local HLR\n",
osmo_mslookup_result_name_c(OTC_SELECT, query, NULL));
return false;
}
if (!subscr->vlr_number[0]) {
LOGP(DMSLOOKUP, LOGL_DEBUG, "%s: not attached (vlr_number unset)\n",
osmo_mslookup_result_name_c(OTC_SELECT, query, NULL));
return false;
}
if (subscr->vlr_via_proxy.len) {
/* The VLR is behind a proxy, the subscriber is not attached to a local VLR but a remote one. That
* remote proxy should instead respond to the service lookup request. */
LOGP(DMSLOOKUP, LOGL_DEBUG, "%s: last attach is not at local VLR, but at VLR '%s' via proxy %s\n",
osmo_mslookup_result_name_c(OTC_SELECT, query, NULL),
subscr->vlr_number,
osmo_ipa_name_to_str(&subscr->vlr_via_proxy));
return false;
}
if (!timestamp_age(&subscr->last_lu_seen, &age)) {
LOGP(DMSLOOKUP, LOGL_DEBUG, "%s: Invalid last_lu_seen timestamp for subscriber\n",
osmo_mslookup_result_name_c(OTC_SELECT, query, NULL));
return false;
}
if (age > g_hlr->mslookup.server.local_attach_max_age) {
LOGP(DMSLOOKUP, LOGL_DEBUG, "%s: last attach was here, but too long ago: %us > %us\n",
osmo_mslookup_result_name_c(OTC_SELECT, query, NULL),
age, g_hlr->mslookup.server.local_attach_max_age);
return false;
}
*lu_age = age;
osmo_ipa_name_set_str(local_msc_name, subscr->vlr_number);
LOGP(DMSLOOKUP, LOGL_DEBUG, "%s: attached %u seconds ago at local VLR %s\n",
osmo_mslookup_result_name_c(OTC_SELECT, query, NULL),
age, osmo_ipa_name_to_str(local_msc_name));
return true;
}
static bool subscriber_has_done_lu_here(const struct osmo_mslookup_query *query,
uint32_t *lu_age_p,
struct osmo_ipa_name *local_msc_name)
{
bool attached_here;
uint32_t lu_age = 0;
struct osmo_ipa_name msc_name = {};
/* First ask the local HLR db, but if the local proxy record indicates a more recent LU, use that instead.
* For all usual cases, only one of these will reflect a LU, even if a subscriber had more than one home HLR:
* - if the subscriber is known here, we will never proxy.
* - if the subscriber is not known here, this local HLR db will never record a LU.
* However, if a subscriber was being proxied to a remote home HLR, and if then the subscriber was also added to
* the local HLR database, there might occur a situation where both reflect a LU. So, to be safe against all
* situations, compare the two entries.
*/
attached_here = subscriber_has_done_lu_here_hlr(query, &lu_age, &msc_name, NULL);
/* Future: If proxy has a younger lu, replace. */
if (attached_here && !msc_name.len) {
LOGP(DMSLOOKUP, LOGL_ERROR, "%s: attached here, but no VLR name known\n",
osmo_mslookup_result_name_c(OTC_SELECT, query, NULL));
return false;
}
if (!attached_here) {
/* Already logged "not attached" for both local-db and proxy attach */
return false;
}
LOGP(DMSLOOKUP, LOGL_INFO, "%s: attached here, at VLR %s\n",
osmo_mslookup_result_name_c(OTC_SELECT, query, NULL),
osmo_ipa_name_to_str(&msc_name));
*lu_age_p = lu_age;
*local_msc_name = msc_name;
return true;
}
/* A remote entity is asking us whether we are providing the given service for the given subscriber. */
void mslookup_server_rx(const struct osmo_mslookup_query *query,
struct osmo_mslookup_result *result)
{
const struct mslookup_service_host *service_host;
uint32_t age;
struct osmo_ipa_name msc_name;
/* A request for a home HLR: answer exactly if this is the subscriber's home HLR, i.e. the IMSI is listed in the
* HLR database. */
if (strcmp(query->service, OSMO_MSLOOKUP_SERVICE_HLR_GSUP) == 0)
return mslookup_server_rx_hlr_gsup(query, result);
/* All other service types: answer when the subscriber has done a LU that is either listed in the local HLR or
* in the GSUP proxy database: i.e. if the subscriber has done a Location Updating at an VLR belonging to this
* HLR. Respond with whichever services are configured in the osmo-hlr.cfg. */
if (!subscriber_has_done_lu_here(query, &age, &msc_name)) {
*result = not_found;
return;
}
/* We've detected a LU here. The VLR where the LU happened is stored in msc_unit_name, and the LU age is stored
* in 'age'. Figure out the address configured for that VLR and service name. */
service_host = mslookup_server_service_get(&msc_name, query->service);
if (!service_host) {
/* Find such service set globally (no VLR unit name) */
service_host = mslookup_server_service_get(&mslookup_server_msc_wildcard, query->service);
}
if (!service_host) {
LOGP(DMSLOOKUP, LOGL_ERROR,
"%s: subscriber found, but no service %s configured, cannot service lookup request\n",
osmo_mslookup_result_name_c(OTC_SELECT, query, NULL),
osmo_quote_str_c(OTC_SELECT, query->service, -1));
*result = not_found;
return;
}
set_result(result, service_host, age);
}

53
src/timestamp.c Normal file
View File

@ -0,0 +1,53 @@
/* Copyright 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 <osmocom/core/timer.h>
#include <osmocom/hlr/timestamp.h>
/* Central implementation to set a timestamp to the current time, in case we want to modify this in the future. */
void timestamp_update(timestamp_t *timestamp)
{
struct timeval tv;
time_t raw;
struct tm utc;
/* The simpler way would be just time(&raw), but by using osmo_gettimeofday() we can also use
* osmo_gettimeofday_override for unit tests independent from real time. */
osmo_gettimeofday(&tv, NULL);
raw = tv.tv_sec;
gmtime_r(&raw, &utc);
*timestamp = mktime(&utc);
}
/* Calculate seconds since a given timestamp was taken. Return true for a valid age returned in age_p, return false if
* the timestamp is either in the future or the age surpasses uint32_t range. When false is returned, *age_p is set to
* UINT32_MAX. */
bool timestamp_age(const timestamp_t *timestamp, uint32_t *age_p)
{
int64_t age64;
timestamp_t now;
timestamp_update(&now);
age64 = (int64_t)now - (int64_t)(*timestamp);
if (age64 < 0 || age64 > UINT32_MAX) {
*age_p = UINT32_MAX;
return false;
}
*age_p = (uint32_t)age64;
return true;
}