/* Copyright 2019 by sysmocom s.f.m.c. GmbH * * All Rights Reserved * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 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 General Public License for more details. * * You should have received a copy of the GNU General Public License along * with this program. If not, see . */ #include #include #include #include /*! \addtogroup mslookup * * Distributed GSM: finding subscribers * * There are various aspects of the D-GSM code base in osmo-hlr.git, here is an overview: * * mslookup is the main enabler of D-GSM, a concept for connecting services between independent core network stacks. * * D-GSM consists of: * (1) mslookup client to find subscribers: * (a) external clients like ESME, SIP PBX, ... ask osmo-hlr to tell where to send SMS, voice calls, ... * (b) osmo-hlr's own mslookup client asks remote osmo-hlrs whether they know a given IMSI. * (2) when a subscriber was found at a remote HLR, GSUP gets forwarded there: * (a) to deliver messages for the GSUP proxy, osmo-hlr manages many GSUP clients to establish links to remote HLRs. * (b) osmo-hlr has a GSUP proxy layer that caches data of IMSIs that get proxied to a remote HLR. * (c) decision making to distinguish local IMSIs from ones proxied to a remote HLR. * * (1) mslookup is a method of finding subscribers using (multicast) queries, by MSISDN or by IMSI. * It is open to various lookup methods, the first one being multicast DNS. * An mslookup client sends a request, and an mslookup server responds. * The mslookup server is implemented by osmo-hlr. mslookup clients are arbitrary programs, like an ESME or a SIP PBX. * Hence the mslookup client is public API, while the mslookup server is implemented "privately" in osmo-hlr. * * (1a) Public mslookup client: libosmo-mslookup * src/mslookup/mslookup.c Things useful for both client and server. * src/mslookup/mslookup_client.c The client API, which can use various lookup methods, * and consolidates results from various responders. * src/mslookup/mslookup_client_mdns.c lookup method implementing multicast DNS, client side. * * src/mslookup/osmo-mslookup-client.c Utility program to ease invocation for (blocking) mslookup clients. * * src/mslookup/mslookup_client_fake.c lookup method generating fake results, for testing client implementations. * * src/mslookup/mdns*.c implementation of DNS to be used by mslookup_client_mdns.c, * and the mslookup_server.c. * * contrib/dgsm/esme_dgsm.py Example implementation for an mslookup enabled SMS handler. * contrib/dgsm/freeswitch_dialplan_dgsm.py Example implementation for an mslookup enabled FreeSWITCH dialplan. * contrib/dgsm/osmo-mslookup-pipe.py Example for writing a python client using the osmo-mslookup-client * cmdline. * contrib/dgsm/osmo-mslookup-socket.py Example for writing a python client using the osmo-mslookup-client * unix domain socket. * * (1b) "Private" mslookup server in osmo-hlr: * src/mslookup_server.c Respond to mslookup queries, independent from the particular lookup method. * src/mslookup_server_mdns.c mDNS specific implementation for mslookup_server.c. * src/dgsm_vty.c Configure services that mslookup server sends to remote requests. * * (2) Proxy and GSUP clients to remote HLR instances: * * (a) Be a GSUP client to forward to a remote HLR: * src/gsupclient/ The same API that is used by osmo-{msc,sgsn} is also used to forward GSUP to remote osmo-hlrs. * src/remote_hlr.c Establish links to remote osmo-hlrs, where this osmo-hlr is a client (proxying e.g. for an MSC). * * (b) Keep track of remotely handled IMSIs: * src/proxy.c Keep track of proxied IMSIs and cache important subscriber data. * * (c) Direct GSUP request to the right destination: either the local or a remote HLR: * src/dgsm.c The glue that makes osmo-hlr distinguish between local IMSIs and those that are proxied to another * osmo-hlr. * src/dgsm_vty.c Config. * * @{ * \file mslookup.c */ const struct value_string osmo_mslookup_id_type_names[] = { { OSMO_MSLOOKUP_ID_NONE, "none" }, { OSMO_MSLOOKUP_ID_IMSI, "imsi" }, { OSMO_MSLOOKUP_ID_MSISDN, "msisdn" }, {} }; const struct value_string osmo_mslookup_result_code_names[] = { { OSMO_MSLOOKUP_RC_NONE, "none" }, { OSMO_MSLOOKUP_RC_RESULT, "result" }, { OSMO_MSLOOKUP_RC_NOT_FOUND, "not-found" }, {} }; /*! Compare two struct osmo_mslookup_id. * \returns 0 if a and b are equal, * < 0 if a (or the ID type / start of ID) is < b, * > 0 if a (or the ID type / start of ID) is > b. */ int osmo_mslookup_id_cmp(const struct osmo_mslookup_id *a, const struct osmo_mslookup_id *b) { int cmp; if (a == b) return 0; if (!a) return -1; if (!b) return 1; cmp = OSMO_CMP(a->type, b->type); if (cmp) return cmp; switch (a->type) { case OSMO_MSLOOKUP_ID_IMSI: return strncmp(a->imsi, b->imsi, sizeof(a->imsi)); case OSMO_MSLOOKUP_ID_MSISDN: return strncmp(a->msisdn, b->msisdn, sizeof(a->msisdn)); default: return 0; } } bool osmo_mslookup_id_valid(const struct osmo_mslookup_id *id) { switch (id->type) { case OSMO_MSLOOKUP_ID_IMSI: return osmo_imsi_str_valid(id->imsi); case OSMO_MSLOOKUP_ID_MSISDN: return osmo_msisdn_str_valid(id->msisdn); default: return false; } } bool osmo_mslookup_service_valid(const char *service) { return strlen(service) > 0; } /*! Write ID and ID type to a buffer. * \param[out] buf nul-terminated {id}.{id_type} string (e.g. "1234.msisdn") or * "?.none" if the ID type is invalid. * \returns amount of bytes written to buf. */ size_t osmo_mslookup_id_name_buf(char *buf, size_t buflen, const struct osmo_mslookup_id *id) { struct osmo_strbuf sb = { .buf = buf, .len = buflen }; switch (id->type) { case OSMO_MSLOOKUP_ID_IMSI: OSMO_STRBUF_PRINTF(sb, "%s", id->imsi); break; case OSMO_MSLOOKUP_ID_MSISDN: OSMO_STRBUF_PRINTF(sb, "%s", id->msisdn); break; default: OSMO_STRBUF_PRINTF(sb, "?"); break; } OSMO_STRBUF_PRINTF(sb, ".%s", osmo_mslookup_id_type_name(id->type)); return sb.chars_needed; } /*! Same as osmo_mslookup_id_name_buf(), but return a talloc allocated string of sufficient size. */ char *osmo_mslookup_id_name_c(void *ctx, const struct osmo_mslookup_id *id) { OSMO_NAME_C_IMPL(ctx, 64, "ERROR", osmo_mslookup_id_name_buf, id) } /*! Same as osmo_mslookup_id_name_buf(), but directly return the char* (for printf-like string formats). */ char *osmo_mslookup_id_name_b(char *buf, size_t buflen, const struct osmo_mslookup_id *id) { int rc = osmo_mslookup_id_name_buf(buf, buflen, id); if (rc < 0 && buflen) buf[0] = '\0'; return buf; } /*! Write mslookup result string to buffer. * \param[in] query with the service, ID and ID type to be written to buf like a domain string, or NULL to omit. * \param[in] result with the result code, IPv4/v6 and age to be written to buf or NULL to omit. * \param[out] buf result as flat string, which looks like the following for a valid query and result with IPv4 and v6 * answer: "sip.voice.1234.msisdn -> ipv4: 42.42.42.42:1337 -> ipv6: [1234:5678:9ABC::]:1338 (age=1)", * the result part can also be " -> timeout" or " -> rc=5" depending on the result code. * \returns amount of bytes written to buf. */ size_t osmo_mslookup_result_to_str_buf(char *buf, size_t buflen, const struct osmo_mslookup_query *query, const struct osmo_mslookup_result *result) { struct osmo_strbuf sb = { .buf = buf, .len = buflen }; if (query) { OSMO_STRBUF_PRINTF(sb, "%s.", query->service); OSMO_STRBUF_APPEND(sb, osmo_mslookup_id_name_buf, &query->id); } if (result && result->rc == OSMO_MSLOOKUP_RC_NONE) result = NULL; if (result) { if (result->rc != OSMO_MSLOOKUP_RC_RESULT) { OSMO_STRBUF_PRINTF(sb, " %s", osmo_mslookup_result_code_name(result->rc)); } else { if (result->host_v4.ip[0]) { OSMO_STRBUF_PRINTF(sb, " -> ipv4: " OSMO_SOCKADDR_STR_FMT, OSMO_SOCKADDR_STR_FMT_ARGS(&result->host_v4)); } if (result->host_v6.ip[0]) { OSMO_STRBUF_PRINTF(sb, " -> ipv6: " OSMO_SOCKADDR_STR_FMT, OSMO_SOCKADDR_STR_FMT_ARGS(&result->host_v6)); } OSMO_STRBUF_PRINTF(sb, " (age=%u)", result->age); } OSMO_STRBUF_PRINTF(sb, " %s", result->last ? "(last)" : "(not-last)"); } return sb.chars_needed; } /*! Same as osmo_mslookup_result_to_str_buf(), but return a talloc allocated string of sufficient size. */ char *osmo_mslookup_result_name_c(void *ctx, const struct osmo_mslookup_query *query, const struct osmo_mslookup_result *result) { OSMO_NAME_C_IMPL(ctx, 64, "ERROR", osmo_mslookup_result_to_str_buf, query, result) } /*! Same as osmo_mslookup_result_to_str_buf(), but directly return the char* (for printf-like string formats). */ char *osmo_mslookup_result_name_b(char *buf, size_t buflen, const struct osmo_mslookup_query *query, const struct osmo_mslookup_result *result) { int rc = osmo_mslookup_result_to_str_buf(buf, buflen, query, result); if (rc < 0 && buflen) buf[0] = '\0'; return buf; } /*! Copy part of a string to a buffer and nul-terminate it. * \returns 0 on success, negative on error. */ static int token(char *dest, size_t dest_size, const char *start, const char *end) { int len; if (start >= end) return -10; len = end - start; if (len >= dest_size) return -11; strncpy(dest, start, len); dest[len] = '\0'; return 0; } /*! Parse a string like "foo.moo.goo.123456789012345.msisdn" into service="foo.moo.goo", id="123456789012345" and * id_type="msisdn", placed in a struct osmo_mslookup_query. * \param q Write parsed query to this osmo_mslookup_query. * \param domain Human readable domain string like "sip.voice.12345678.msisdn". * \returns 0 on success, negative on error. */ int osmo_mslookup_query_init_from_domain_str(struct osmo_mslookup_query *q, const char *domain) { const char *last_dot; const char *second_last_dot; const char *id_type; const char *id; int rc; *q = (struct osmo_mslookup_query){}; if (!domain) return -1; last_dot = strrchr(domain, '.'); if (!last_dot) return -2; if (last_dot <= domain) return -3; for (second_last_dot = last_dot - 1; second_last_dot > domain && *second_last_dot != '.'; second_last_dot--); if (second_last_dot == domain || *second_last_dot != '.') return -3; id_type = last_dot + 1; if (!*id_type) return -4; q->id.type = get_string_value(osmo_mslookup_id_type_names, id_type); id = second_last_dot + 1; switch (q->id.type) { case OSMO_MSLOOKUP_ID_IMSI: rc = token(q->id.imsi, sizeof(q->id.imsi), id, last_dot); if (rc) return rc; if (!osmo_imsi_str_valid(q->id.imsi)) return -5; break; case OSMO_MSLOOKUP_ID_MSISDN: rc = token(q->id.msisdn, sizeof(q->id.msisdn), id, last_dot); if (rc) return rc; if (!osmo_msisdn_str_valid(q->id.msisdn)) return -6; break; default: return -7; } return token(q->service, sizeof(q->service), domain, second_last_dot); } /*! @} */