/* GPRS LLC protocol primitive implementation as per 3GPP TS 44.064 */ /* * (C) 2022 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 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 . * */ #include #include #include #include #include #include #include #include #define LLC_MSGB_HEADROOM 0 const struct value_string osmo_gprs_llc_prim_sap_names[] = { { OSMO_GPRS_LLC_SAP_LLGMM, "LLGMM" }, { OSMO_GPRS_LLC_SAP_LL, "LL" }, { OSMO_GPRS_LLC_SAP_GRR, "GRR" }, { OSMO_GPRS_LLC_SAP_BSSGP, "BSSGP" }, { 0, NULL } }; const char *osmo_gprs_llc_prim_name(const struct osmo_gprs_llc_prim *llc_prim) { static char name_buf[256]; const char *sap = osmo_gprs_llc_prim_sap_name(llc_prim->oph.sap); const char *op = get_value_string(osmo_prim_op_names, llc_prim->oph.operation); const char *type; switch (llc_prim->oph.sap) { case OSMO_GPRS_LLC_SAP_LLGMM: type = osmo_gprs_llc_llgmm_prim_type_name(llc_prim->oph.primitive); break; case OSMO_GPRS_LLC_SAP_LL: type = osmo_gprs_llc_ll_prim_type_name(llc_prim->oph.primitive); break; case OSMO_GPRS_LLC_SAP_GRR: type = osmo_gprs_llc_grr_prim_type_name(llc_prim->oph.primitive); break; case OSMO_GPRS_LLC_SAP_BSSGP: type = osmo_gprs_llc_bssgp_prim_type_name(llc_prim->oph.primitive); break; default: type = "unsupported-llc-sap"; } snprintf(name_buf, sizeof(name_buf), "%s-%s.%s", sap, type, op); return name_buf; } static int llc_up_cb_dummy(struct osmo_gprs_llc_prim *llc_prim, void *user_data) { LOGLLC(LOGL_INFO, "llc_up_cb_dummy(%s)\n", osmo_gprs_llc_prim_name(llc_prim)); return 0; } static int llc_down_cb_dummy(struct osmo_gprs_llc_prim *llc_prim, void *user_data) { LOGLLC(LOGL_INFO, "llc_down_cb_dummy(%s)\n", osmo_gprs_llc_prim_name(llc_prim)); return 0; } /* Set callback used by LLC layer to push primitives to higher layers in protocol stack */ void osmo_gprs_llc_prim_set_up_cb(osmo_gprs_llc_prim_up_cb up_cb, void *up_user_data) { g_llc_ctx->llc_up_cb = up_cb; g_llc_ctx->llc_up_cb_user_data = up_user_data; } /* Set callback used by LLC layer to push primitives to lower layers in protocol stack */ void osmo_gprs_llc_prim_set_down_cb(osmo_gprs_llc_prim_down_cb down_cb, void *down_user_data) { g_llc_ctx->llc_down_cb = down_cb; g_llc_ctx->llc_down_cb_user_data = down_user_data; } /******************************** * Primitive allocation: ********************************/ /* allocate a msgb containing a struct osmo_gprs_llc_prim + optional l3 data */ static struct msgb *gprs_llc_prim_msgb_alloc(unsigned int l3_len) { const int headroom = LLC_MSGB_HEADROOM; const int size = headroom + sizeof(struct osmo_gprs_llc_prim) + l3_len; struct msgb *msg = msgb_alloc_headroom(size, headroom, "llc_prim"); if (!msg) return NULL; msg->l1h = msgb_put(msg, sizeof(struct osmo_gprs_llc_prim)); return msg; } struct osmo_gprs_llc_prim *gprs_llc_prim_alloc(enum osmo_gprs_llc_prim_sap sap, unsigned int type, enum osmo_prim_operation operation, unsigned int l3_len) { struct msgb *msg = gprs_llc_prim_msgb_alloc(l3_len); struct osmo_gprs_llc_prim *llc_prim = msgb_llc_prim(msg); osmo_prim_init(&llc_prim->oph, sap, type, operation, msg); return llc_prim; } int gprs_llc_prim_handle_unsupported(struct osmo_gprs_llc_prim *llc_prim) { LOGLLC(LOGL_ERROR, "Unsupported llc_prim! %s\n", osmo_gprs_llc_prim_name(llc_prim)); msgb_free(llc_prim->oph.msg); return -ENOTSUP; } /******************************** * Handling from/to upper layers: ********************************/ int gprs_llc_prim_call_up_cb(struct osmo_gprs_llc_prim *llc_prim) { int rc; if (g_llc_ctx->llc_up_cb) rc = g_llc_ctx->llc_up_cb(llc_prim, g_llc_ctx->llc_up_cb_user_data); else rc = llc_up_cb_dummy(llc_prim, g_llc_ctx->llc_up_cb_user_data); /* Special return value '1' means: do not free */ if (rc != 1) msgb_free(llc_prim->oph.msg); return rc; } /* LLC higher layers push LLC primitive down to LLC layer: */ int osmo_gprs_llc_prim_upper_down(struct osmo_gprs_llc_prim *llc_prim) { int rc; OSMO_ASSERT(g_llc_ctx); LOGLLC(LOGL_INFO, "Rx from upper layers: %s\n", osmo_gprs_llc_prim_name(llc_prim)); switch (llc_prim->oph.sap) { case OSMO_GPRS_LLC_SAP_LLGMM: rc = gprs_llc_prim_llgmm_upper_down(llc_prim); break; case OSMO_GPRS_LLC_SAP_LL: rc = gprs_llc_prim_ll_upper_down(llc_prim); break; default: rc = gprs_llc_prim_handle_unsupported(llc_prim); } return rc; } /******************************** * Handling from/to lower layers: ********************************/ int gprs_llc_prim_call_down_cb(struct osmo_gprs_llc_prim *llc_prim) { int rc; if (g_llc_ctx->llc_down_cb) rc = g_llc_ctx->llc_down_cb(llc_prim, g_llc_ctx->llc_down_cb_user_data); else rc = llc_down_cb_dummy(llc_prim, g_llc_ctx->llc_down_cb_user_data); /* Special return value '1' means: do not free */ if (rc != 1) msgb_free(llc_prim->oph.msg); else rc = 0; return rc; } /* LLC lower layers push LLC primitive up to LLC layer: */ int osmo_gprs_llc_prim_lower_up(struct osmo_gprs_llc_prim *llc_prim) { OSMO_ASSERT(g_llc_ctx); OSMO_ASSERT(llc_prim); struct msgb *msg = llc_prim->oph.msg; int rc; LOGLLC(LOGL_INFO, "Rx from lower layers: %s\n", osmo_gprs_llc_prim_name(llc_prim)); switch (llc_prim->oph.sap) { case OSMO_GPRS_LLC_SAP_GRR: OSMO_ASSERT(g_llc_ctx->location == OSMO_GPRS_LLC_LOCATION_MS); rc = gprs_llc_prim_lower_up_grr(llc_prim); break; case OSMO_GPRS_LLC_SAP_BSSGP: OSMO_ASSERT(g_llc_ctx->location == OSMO_GPRS_LLC_LOCATION_SGSN); rc = gprs_llc_prim_lower_up_bssgp(llc_prim); break; default: rc = -EINVAL; } /* Special return value '1' means: do not free */ if (rc != 1) msgb_free(msg); else rc = 0; return rc; }