diff options
Diffstat (limited to 'src/sccp_scmg.c')
| -rw-r--r-- | src/sccp_scmg.c | 131 |
1 files changed, 131 insertions, 0 deletions
diff --git a/src/sccp_scmg.c b/src/sccp_scmg.c index 4a8ccf6..0e3905d 100644 --- a/src/sccp_scmg.c +++ b/src/sccp_scmg.c @@ -30,6 +30,7 @@ #include <osmocom/sigtran/sccp_sap.h> #include <osmocom/sigtran/protocol/sua.h> +#include <osmocom/sigtran/protocol/sccp_scmg.h> #include <osmocom/sccp/sccp_types.h> #include "xua_internal.h" @@ -81,3 +82,133 @@ void sccp_scmg_rx_mtp_resume(struct osmo_sccp_instance *inst, uint32_t dpc) /* 8) local broadcast of "user-in-service" * [this would require us to track SSNs at each PC, which we don't] */ } + +const struct value_string sccp_scmg_msgt_names[] = { + { SCCP_SCMG_MSGT_SSA, "SSA (Subsystem Allowed)" }, + { SCCP_SCMG_MSGT_SSP, "SSP (Subsystem Prohibited)" }, + { SCCP_SCMG_MSGT_SST, "SST (Subsystem Status Test)" }, + { SCCP_SCMG_MSGT_SOR, "SOR (Subsystem Out-of-service Request)" }, + { SCCP_SCMG_MSGT_SOG, "SOG (Subsystem Out-of-service Grant)" }, + { SCCP_SCMG_MSGT_SSC, "SSC (Subsystem Congested)" }, + { 0, NULL } +}; + +static int sccp_scmg_tx(struct osmo_sccp_user *scu, const struct osmo_sccp_addr *calling_addr, + const struct osmo_sccp_addr *called_addr, + uint8_t msg_type, uint8_t ssn, uint16_t pc, uint8_t smi, uint8_t *ssc_cong_lvl) +{ + struct msgb *msg = sccp_msgb_alloc(__func__); + struct osmo_scu_prim *prim; + struct osmo_scu_unitdata_param *param; + struct sccp_scmg_msg *scmg; + + /* fill primitive header */ + prim = (struct osmo_scu_prim *) msgb_put(msg, sizeof(*prim)); + param = &prim->u.unitdata; + memcpy(¶m->calling_addr, calling_addr, sizeof(*calling_addr)); + memcpy(¶m->called_addr, called_addr, sizeof(*called_addr)); + osmo_prim_init(&prim->oph, SCCP_SAP_USER, OSMO_SCU_PRIM_N_UNITDATA, PRIM_OP_REQUEST, msg); + + /* Fill the actual SCMG message */ + msg->l2h = msgb_put(msg, sizeof(*scmg)); + scmg = (struct sccp_scmg_msg *) msg->l2h; + scmg->msg_type = msg_type; + scmg->affected_ssn = ssn; + scmg->affected_pc = pc; + scmg->smi = smi; + + /* add congestion level in case of SSC message */ + if (msg_type == SCCP_SCMG_MSGT_SSC) { + msgb_put(msg, 1); + OSMO_ASSERT(ssc_cong_lvl); + scmg->ssc_congestion_lvl[1] = *ssc_cong_lvl; + } + + return osmo_sccp_user_sap_down(scu, &prim->oph); +} + + +/* Subsystem Test received */ +static int scmg_rx_sst(struct osmo_sccp_user *scu, const struct osmo_sccp_addr *calling_addr, + const struct osmo_sccp_addr *called_addr, const struct sccp_scmg_msg *sst) +{ + /* Q.714 5.3.4.3 Actions at the receiving side (of SST) */ + + /* check "ignore subsystem status test" and bail out */ + /* check if SSN in question is available. If yes, return SSA. If not, ignore */ + scu = sccp_user_find(scu->inst, sst->affected_ssn, sst->affected_pc); + if (!scu) + return 0; + + /* is subsystem available? */ + if (0 /* !subsys_available(scu) */) + return 0; + + return sccp_scmg_tx(scu, called_addr, calling_addr, SCCP_SCMG_MSGT_SSA, + sst->affected_ssn, sst->affected_pc, 0, NULL); +} + +static int scmg_rx(struct osmo_sccp_user *scu, const struct osmo_sccp_addr *calling_addr, + const struct osmo_sccp_addr *called_addr, const struct sccp_scmg_msg *scmg) +{ + switch (scmg->msg_type) { + case SCCP_SCMG_MSGT_SST: + return scmg_rx_sst(scu, calling_addr, called_addr, scmg); + case SCCP_SCMG_MSGT_SSP: + case SCCP_SCMG_MSGT_SSA: + case SCCP_SCMG_MSGT_SOR: + case SCCP_SCMG_MSGT_SOG: + case SCCP_SCMG_MSGT_SSC: + default: + LOGP(DLSCCP, LOGL_NOTICE, "Rx unsupported SCCP SCMG %s, ignoring", + sccp_scmg_msgt_name(scmg->msg_type)); + break; + } + return 0; +} + +/* main entry point for SCCP user primitives from SCRC/SCOC */ +static int scmg_prim_cb(struct osmo_prim_hdr *oph, void *_scu) +{ + struct osmo_sccp_user *scu = _scu; + struct osmo_scu_prim *prim = (struct osmo_scu_prim *) oph; + struct osmo_scu_unitdata_param *param; + struct sccp_scmg_msg *scmg; + int rc = 0; + + switch (OSMO_PRIM_HDR(oph)) { + case OSMO_PRIM(OSMO_SCU_PRIM_N_UNITDATA, PRIM_OP_INDICATION): + param = &prim->u.unitdata; + scmg = msgb_l2(oph->msg); + /* ensure minimum length based on message type */ + if (msgb_l2len(oph->msg) < sizeof(*scmg)) { + rc = -1; + break; + } + if (scmg->msg_type == SCCP_SCMG_MSGT_SSC && msgb_l2len(oph->msg) < sizeof(*scmg)+1) { + rc = -1; + break; + } + /* interestingly, PC is specified to be encoded in little endian ?!? */ + scmg->affected_pc = osmo_load16le(&scmg->affected_pc); + rc = scmg_rx(scu, ¶m->calling_addr, ¶m->called_addr, scmg); + break; + default: + LOGP(DLSCCP, LOGL_ERROR, "unsupported SCCP user primitive %s\n", + osmo_scu_prim_name(oph)); + break; + } + + msgb_free(oph->msg); + return rc; +} + +/* register SCMG as SCCP user for SSN=1 */ +int sccp_scmg_init(struct osmo_sccp_instance *inst) +{ + struct osmo_sccp_user *scu; + scu = osmo_sccp_user_bind(inst, "SCCP Maangement", scmg_prim_cb, SCCP_SSN_MANAGEMENT); + if (!scu) + return -1; + return 0; +} |