diff options
Diffstat (limited to 'openbsc/src/libmsc/a_iface.c')
| -rw-r--r-- | openbsc/src/libmsc/a_iface.c | 218 |
1 files changed, 187 insertions, 31 deletions
diff --git a/openbsc/src/libmsc/a_iface.c b/openbsc/src/libmsc/a_iface.c index 869cd7887..19d853c88 100644 --- a/openbsc/src/libmsc/a_iface.c +++ b/openbsc/src/libmsc/a_iface.c @@ -37,12 +37,108 @@ #include <openbsc/mgcpgw_client.h> #include <osmocom/core/byteswap.h> #include <osmocom/sccp/sccp_types.h> +#include <openbsc/a_reset.h> +#include <openbsc/osmo_msc.h> /* A pointer to the GSM network we work with. By the current paradigm, * there can only be one gsm_network per MSC. The pointer is set once * when calling a_init() */ static struct gsm_network *gsm_network = NULL; +/* A struct to track currently active connections. We need that information + * to handle failure sitautions. In case of a problem, we must know which + * connections are currently open and which BSC is responsible. We also need + * the data to perform our connection checks (a_reset). All other logic will + * look at the connection ids and addresses that are supplied by the + * primitives */ +struct bsc_conn { + struct llist_head list; + struct osmo_sccp_addr called_addr; /* BSC (remote) */ + struct osmo_sccp_addr calling_addr; /* MSC (local) */ + uint32_t conn_id; /* Connection identifier */ +}; + +/* Internal list with connections we currently maintain. This + * list is of type struct bsc_conn (see above) */ +static LLIST_HEAD(active_connections); + +/* Context information about the BSC, will be used only internally in this + * file to manage the BSCs we are associated with */ +struct bsc_context { + struct llist_head list; + struct a_reset_ctx reset; /* Reset FSM (one per BSC) */ + struct osmo_sccp_addr called_addr; /* BSC (remote) */ + struct osmo_sccp_addr calling_addr; /* MSC (local) */ + struct osmo_sccp_user *sccp_user; /* SCCP user (the same for all) */ +}; + +/* List with BSCs we are associated with. This list is of type + * struct bsc_context (see above) */ +static LLIST_HEAD(bsc_context_list); + +/* Record info of a new active connection in the active connection list */ +static void record_bsc_con(void *ctx, struct osmo_sccp_addr *called_addr, struct osmo_sccp_addr *calling_addr, + uint32_t conn_id) +{ + struct bsc_conn *conn; + + conn = talloc_zero(ctx, struct bsc_conn); + OSMO_ASSERT(conn); + + memcpy(&conn->called_addr, called_addr, sizeof(*called_addr)); + memcpy(&conn->calling_addr, calling_addr, sizeof(*calling_addr)); + conn->conn_id = conn_id; + + llist_add_tail(&conn->list, &active_connections); +} + +/* Delete info of a closed connection from the active connection list */ +void a_delete_bsc_con(uint32_t conn_id) +{ + struct bsc_conn *conn; + struct bsc_conn *conn_temp; + + llist_for_each_entry_safe(conn, conn_temp, &active_connections, list) { + if (conn->conn_id == conn_id) { + llist_del(&conn->list); + talloc_free(conn); + } + } +} + +/* Check if a specified connection id has an active SCCP connection */ +static bool check_connection_active(uint32_t conn_id) +{ + struct bsc_conn *conn; + + /* Find the address for the current connection id */ + llist_for_each_entry(conn, &active_connections, list) { + if (conn->conn_id == conn_id) { + return true; + } + } + + return false; +} + +/* Get the reset context for a specifiec calling (BSC) address */ +static struct a_reset_ctx *get_reset_ctx_by_sccp_addr(struct osmo_sccp_addr *addr) +{ + struct bsc_context *bsc_ctx; + + if (!addr) + return NULL; + + llist_for_each_entry(bsc_ctx, &bsc_context_list, list) { + if (memcmp(&bsc_ctx->called_addr, addr, sizeof(*addr)) == 0) + return &bsc_ctx->reset; + } + + LOGP(DMSC, LOGL_ERROR, "The calling BSC (%s) is unknown to this MSC ...\n", + osmo_sccp_addr_dump(addr)); + return NULL; +} + /* Send DTAP message via A-interface */ int a_iface_tx_dtap(struct msgb *msg) { @@ -107,9 +203,9 @@ int a_iface_tx_cipher_mode(struct gsm_subscriber_connection *conn, /* Page a subscriber via A-interface */ int a_iface_tx_paging(const char *imsi, uint32_t tmsi, uint16_t lac) { - struct a_bsc_addr *addr; - struct llist_head *bsc_addr_list = get_bsc_addr_list(); + struct bsc_context *bsc_ctx; struct gsm0808_cell_id_list cil; + struct msgb *msg; int page_count = 0; cil.id_discr = CELL_IDENT_LAC; @@ -117,16 +213,26 @@ int a_iface_tx_paging(const char *imsi, uint32_t tmsi, uint16_t lac) cil.id_list_len = 1; /* Deliver paging request to all known BSCs */ - llist_for_each_entry(addr, bsc_addr_list, list) { - LOGP(DMSC, LOGL_DEBUG, "Passing paging message from MSC to BSC %s (imsi=%s, tmsi=0x%08x, lac=%u)\n", - osmo_sccp_addr_dump(&addr->calling_addr), imsi, tmsi, lac); - osmo_sccp_tx_unitdata_msg(addr->scu, &addr->called_addr, &addr->calling_addr, - gsm0808_create_paging(imsi, &tmsi, &cil, NULL)); - page_count++; + llist_for_each_entry(bsc_ctx, &bsc_context_list, list) { + if (a_reset_conn_ready(&bsc_ctx->reset)) { + LOGP(DMSC, LOGL_DEBUG, + "Passing paging message from MSC %s to BSC %s (imsi=%s, tmsi=0x%08x, lac=%u)\n", + osmo_sccp_addr_dump(&bsc_ctx->calling_addr), + osmo_sccp_addr_dump(&bsc_ctx->called_addr), imsi, tmsi, lac); + msg = gsm0808_create_paging(imsi, &tmsi, &cil, NULL); + osmo_sccp_tx_unitdata_msg(bsc_ctx->sccp_user, + &bsc_ctx->calling_addr, &bsc_ctx->called_addr, msg); + page_count++; + } else { + LOGP(DMSC, LOGL_DEBUG, + "Connection down, dropping paging from MSC %s to BSC %s (imsi=%s, tmsi=0x%08x, lac=%u)\n", + osmo_sccp_addr_dump(&bsc_ctx->calling_addr), + osmo_sccp_addr_dump(&bsc_ctx->called_addr), imsi, tmsi, lac); + } } if (page_count <= 0) - LOGP(DMSC, LOGL_ERROR, "Could not deliver paging because no BSC is available!\n"); + LOGP(DMSC, LOGL_ERROR, "Could not deliver paging because none of the associated BSCs is available!\n"); return page_count; } @@ -303,26 +409,6 @@ int a_iface_tx_assignment(struct gsm_trans *trans) return osmo_sccp_tx_data_msg(conn->a.scu, conn->a.conn_id, msg); } -/* Check if we already know this BSC from a successfuly executed reset procedure. */ -static bool test_bsc_known(struct osmo_sccp_addr *bsc_addr) -{ - struct a_bsc_addr *addr; - struct llist_head *bsc_addr_list = get_bsc_addr_list(); - - /* Check if the given address is */ - llist_for_each_entry(addr, bsc_addr_list, list) { - if (memcmp(&addr->calling_addr, bsc_addr, sizeof(*bsc_addr)) == 0) { - LOGP(DMSC, LOGL_ERROR, "The calling BSC (%s) is known by this MSC, proceeding...\n", - osmo_sccp_addr_dump(bsc_addr)); - return true; - } - } - - LOGP(DMSC, LOGL_ERROR, "The calling BSC (%s) is unknown to this MSC, rejecting...\n", - osmo_sccp_addr_dump(bsc_addr)); - return false; -} - /* Callback function, called by the SSCP stack when data arrives */ static int sccp_sap_up(struct osmo_prim_hdr *oph, void *_scu) { @@ -332,6 +418,7 @@ static int sccp_sap_up(struct osmo_prim_hdr *oph, void *_scu) struct a_conn_info a_conn_info; memset(&a_conn_info, 0, sizeof(a_conn_info)); a_conn_info.network = gsm_network; + a_conn_info.reset = NULL; switch (OSMO_PRIM_HDR(&scu_prim->oph)) { case OSMO_PRIM(OSMO_SCU_PRIM_N_CONNECT, PRIM_OP_INDICATION): @@ -339,8 +426,9 @@ static int sccp_sap_up(struct osmo_prim_hdr *oph, void *_scu) a_conn_info.conn_id = scu_prim->u.connect.conn_id; a_conn_info.called_addr = &scu_prim->u.connect.called_addr; a_conn_info.calling_addr = &scu_prim->u.connect.calling_addr; + a_conn_info.reset = get_reset_ctx_by_sccp_addr(&scu_prim->u.unitdata.calling_addr); - if (test_bsc_known(a_conn_info.calling_addr) == false) { + if (a_reset_conn_ready(a_conn_info.reset) == false) { rc = osmo_sccp_tx_disconn(scu, a_conn_info.conn_id, a_conn_info.called_addr, SCCP_RETURN_CAUSE_UNQUALIFIED); break; @@ -353,6 +441,8 @@ static int sccp_sap_up(struct osmo_prim_hdr *oph, void *_scu) rc = sccp_rx_dt(scu, &a_conn_info, oph->msg); } else LOGP(DMSC, LOGL_DEBUG, "N-CONNECT.ind(%u)\n", scu_prim->u.connect.conn_id); + + record_bsc_con(scu, &scu_prim->u.connect.calling_addr, &scu_prim->u.connect.called_addr, scu_prim->u.connect.conn_id); break; case OSMO_PRIM(OSMO_SCU_PRIM_N_DATA, PRIM_OP_INDICATION): @@ -367,6 +457,8 @@ static int sccp_sap_up(struct osmo_prim_hdr *oph, void *_scu) /* Handle inbound UNITDATA */ a_conn_info.called_addr = &scu_prim->u.unitdata.called_addr; a_conn_info.calling_addr = &scu_prim->u.unitdata.calling_addr; + a_conn_info.reset = get_reset_ctx_by_sccp_addr(&scu_prim->u.unitdata.calling_addr); + DEBUGP(DMSC, "N-UNITDATA.ind(%s)\n", osmo_hexdump(msgb_l2(oph->msg), msgb_l2len(oph->msg))); sccp_rx_udt(scu, &a_conn_info, oph->msg); break; @@ -379,16 +471,80 @@ static int sccp_sap_up(struct osmo_prim_hdr *oph, void *_scu) return rc; } +/* Clear all subscriber connections on a specified BSC */ +void a_clear_all(struct osmo_sccp_user *scu, struct osmo_sccp_addr *bsc_addr) +{ + struct gsm_subscriber_connection *conn; + struct gsm_subscriber_connection *conn_temp; + struct gsm_network *network = gsm_network; + + llist_for_each_entry_safe(conn, conn_temp, &network->subscr_conns, entry) { + /* Clear only A connections and connections that actually + * belong to the specified BSC */ + if (conn->via_ran == RAN_GERAN_A + && memcmp(bsc_addr, &conn->a.bsc_addr, sizeof(conn->a.bsc_addr)) == 0) { + LOGP(DMSC, LOGL_NOTICE, "Dropping orphaned subscriber connection (conn_id %i)\n", conn->a.conn_id); + msc_clear_request(conn, GSM48_CC_CAUSE_SWITCH_CONG); + + /* If there is still an SCCP connection active, remove it now */ + if (check_connection_active(conn->a.conn_id)) { + osmo_sccp_tx_disconn(scu, conn->a.conn_id, bsc_addr, SCCP_RELEASE_CAUSE_END_USER_ORIGINATED); + a_delete_bsc_con(conn->a.conn_id); + } + } + } +} + +/* Callback function: Close all open connections */ +static void a_reset_cb(void *priv) +{ + struct msgb *msg; + struct bsc_context *bsc_ctx = (struct bsc_context*) priv; + + /* Clear all now orphaned subscriber connections */ + a_clear_all(bsc_ctx->sccp_user, &bsc_ctx->called_addr); + + LOGP(DMSC, LOGL_NOTICE, "Sending RESET to BSC %s\n", osmo_sccp_addr_dump(&bsc_ctx->called_addr)); + msg = gsm0808_create_reset(); + osmo_sccp_tx_unitdata_msg(bsc_ctx->sccp_user, &bsc_ctx->calling_addr, + &bsc_ctx->called_addr, msg); +} + /* Initalize A interface connection between to MSC and BSC */ int a_init(void *ctx, struct osmo_sccp_instance *sccp, struct gsm_network *network) { /* FIXME: Remove hardcoded parameters, use parameters in parameter list */ + struct osmo_sccp_user *scu; + struct bsc_context *bsc_ctx; + LOGP(DMSC, LOGL_NOTICE, "Initalizing SCCP connection to stp...\n"); gsm_network = network; /* SCCP Protocol stack */ - osmo_sccp_user_bind(sccp, "OsmoMSC-A", sccp_sap_up, SCCP_SSN_BSSAP); + scu = osmo_sccp_user_bind(sccp, "OsmoMSC-A", sccp_sap_up, SCCP_SSN_BSSAP); + + /* Add some BSCs to the context list */ + /* FIXME: Make this configurable (VTY!) */ + bsc_ctx = talloc_zero(NULL, struct bsc_context); + bsc_ctx->reset.priv = bsc_ctx; + bsc_ctx->reset.cb = a_reset_cb; + llist_add_tail(&bsc_ctx->list, &bsc_context_list); + bsc_ctx->called_addr.presence = OSMO_SCCP_ADDR_T_SSN | OSMO_SCCP_ADDR_T_PC; + bsc_ctx->called_addr.ssn = SCCP_SSN_BSSAP; + bsc_ctx->called_addr.ri = OSMO_SCCP_RI_SSN_PC; + bsc_ctx->called_addr.pc = 23; + bsc_ctx->calling_addr.presence = OSMO_SCCP_ADDR_T_SSN | OSMO_SCCP_ADDR_T_PC; + bsc_ctx->calling_addr.ssn = SCCP_SSN_BSSAP; + bsc_ctx->calling_addr.ri = OSMO_SCCP_RI_SSN_PC; + bsc_ctx->calling_addr.pc = 1; + bsc_ctx->sccp_user = scu; + bsc_ctx = NULL; + + /* Start reset procedure for all BSC connections */ + llist_for_each_entry(bsc_ctx, &bsc_context_list, list) { + a_reset_start(&bsc_ctx->reset); + } return 0; } |