open5gs/src/amf/gnb-info.c

/*
 * Copyright (C) 2025 by Juraj Elias <juraj.elias@gmail.com>
 *
 * This file is part of Open5GS.
 *
 * 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 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 <https://www.gnu.org/licenses/>.
 */

/*
 * GNB info - AMF gNBs JSON dumper for the Prometheus HTTP server (/gnb-info).
 * - gnb_id, plmn, amf, ng, gnb_IP, supported ta_list, slices, num_connceted_ues
 * - pager: /gnb-info?page=0&page_size=100 (0-based, page=-1 without paging) Default: page=0 page_size=100=MAXSIZE
 *
 * path: http://AMF_IP:9090/gnb-info
 * curl -s "http://127.0.0.5:9090/gnb-info?" |jq . 
 * {
 *   "items": [
 *     {
 *       "gnb_id": 100,
 *       "plmn": "99970",
 *       "network": {
 *         "amf_name": "efire-amf0",
 *         "ngap_port": 38412
 *       },
 *       "ng": {
 *         "sctp": {
 *           "peer": "[192.168.168.100]:60110",
 *           "max_out_streams": 2,
 *           "next_ostream_id": 1
 *         },
 *         "setup_success": true
 *       },
 *       "supported_ta_list": [
 *         {
 *           "tac": "000001",
 *           "bplmns": [
 *             {
 *               "plmn": "99970",
 *               "snssai": [
 *                 {
 *                   "sst": 1,
 *                   "sd": "ffffff"
 *                 }
 *               ]
 *             },
 *             {
 *               "plmn": "99971",
 *               "snssai": [
 *                 {
 *                   "sst": 2,
 *                   "sd": "000000"
 *                 }
 *               ]
 *             }
 *           ]
 *         }
 *       ],
 *       "num_connected_ues": 2
 *     }
 *   ],
 *   "pager": {
 *     "page": 0,
 *     "page_size": 100,
 *     "count": 1
 *   }
 * }
 */

#include <stdio.h>
#include <string.h>
#include <stdbool.h>
#include <sys/socket.h>

#include "ogs-core.h"
#include "ogs-proto.h"
#include "context.h"
#include "gnb-info.h"

#include "sbi/openapi/external/cJSON.h"
#include "metrics/prometheus/json_pager.h"

#ifndef GNB_INFO_PAGE_SIZE_DEFAULT
#define GNB_INFO_PAGE_SIZE_DEFAULT 100U
#endif

size_t amf_dump_gnb_info(char *buf, size_t buflen, size_t page, size_t page_size)
{
    return amf_dump_gnb_info_paged(buf, buflen, page, page_size);
}

static inline uint32_t u24_to_u32(ogs_uint24_t v)
{
    uint32_t x = 0; memcpy(&x, &v, sizeof(v) < sizeof(x) ? sizeof(v) : sizeof(x));
    return (x & 0xFFFFFFu);
}

static inline const char *safe_sa_str(ogs_sockaddr_t *sa)
{
    if (!sa) return "";
    int fam = sa->sa.sa_family;
    if (fam != AF_INET && fam != AF_INET6) return "";
    return ogs_sockaddr_to_string_static(sa);
}

static inline int add_plmn_string(cJSON *obj, const char *key, const ogs_plmn_id_t *plmn)
{
    char s[OGS_PLMNIDSTRLEN] = {0};
    if (plmn) ogs_plmn_id_to_string(plmn, s);
    return cJSON_AddStringToObject(obj, key, s) ? 0 : -1;
}

/* ---------- main (paged) ---------- */

size_t amf_dump_gnb_info_paged(char *buf, size_t buflen, size_t page, size_t page_size)
{
    if (!buf || buflen == 0) return 0;

    const bool no_paging = (page == SIZE_MAX);
    if (!no_paging) {
        if (page_size == 0) page_size = GNB_INFO_PAGE_SIZE_DEFAULT;
        if (page_size > GNB_INFO_PAGE_SIZE_DEFAULT) page_size = GNB_INFO_PAGE_SIZE_DEFAULT;
    } else {
        page_size = SIZE_MAX;
        page = 0;
    }

    amf_context_t *ctxt = amf_self();

    cJSON *root = cJSON_CreateObject();
    if (!root) { if (buflen >= 3) { memcpy(buf, "{}", 3); return 2; } buf[0] = '\0'; return 0; }

    cJSON *items = cJSON_AddArrayToObject(root, "items");
    if (!items) { cJSON_Delete(root); if (buflen >= 3) { memcpy(buf, "{}", 3); return 2; } buf[0] = '\0'; return 0; }

    size_t idx = 0, emitted = 0;
    bool has_next = false, oom = false;

    const size_t start_index = json_pager_safe_start_index(no_paging, page, page_size);

    amf_gnb_t *gnb = NULL;
    ogs_list_for_each(&ctxt->gnb_list, gnb) {
        int act = json_pager_advance(no_paging, idx, start_index, emitted, page_size, &has_next);
        if (act == 1) { idx++; continue; }
        if (act == 2) break;

        /* Build the item completely before attaching to items[] */
        cJSON *g = cJSON_CreateObject();
        if (!g) { oom = true; break; }

        /* basics */
        if (!cJSON_AddNumberToObject(g, "gnb_id", (double)(unsigned)gnb->gnb_id)) { cJSON_Delete(g); oom = true; break; }
        if (add_plmn_string(g, "plmn", &gnb->plmn_id) < 0) { cJSON_Delete(g); oom = true; break; }

        /* network */
        {
            cJSON *network = cJSON_CreateObject();
            if (!network) { cJSON_Delete(g); oom = true; break; }

            if (!cJSON_AddStringToObject(network, "amf_name", ctxt->amf_name ? ctxt->amf_name : "")) { cJSON_Delete(network); cJSON_Delete(g); oom = true; break; }
            if (!cJSON_AddNumberToObject(network, "ngap_port", (double)(unsigned)ctxt->ngap_port)) { cJSON_Delete(network); cJSON_Delete(g); oom = true; break; }

            cJSON_AddItemToObjectCS(g, "network", network);
        }

        /* ng + sctp */
        {
            cJSON *ng = cJSON_CreateObject();
            if (!ng) { cJSON_Delete(g); oom = true; break; }

            /* Build sctp first, then attach */
            cJSON *sctp = cJSON_CreateObject();
            if (!sctp) { cJSON_Delete(ng); cJSON_Delete(g); oom = true; break; }

            if (!cJSON_AddStringToObject(sctp, "peer", safe_sa_str(gnb->sctp.addr))) { cJSON_Delete(sctp); cJSON_Delete(ng); cJSON_Delete(g); oom = true; break; }
            if (!cJSON_AddNumberToObject(sctp, "max_out_streams", (double)gnb->max_num_of_ostreams)) { cJSON_Delete(sctp); cJSON_Delete(ng); cJSON_Delete(g); oom = true; break; }
            if (!cJSON_AddNumberToObject(sctp, "next_ostream_id", (double)(unsigned)gnb->ostream_id)) { cJSON_Delete(sctp); cJSON_Delete(ng); cJSON_Delete(g); oom = true; break; }

            cJSON_AddItemToObjectCS(ng, "sctp", sctp);

            if (!cJSON_AddBoolToObject(ng, "setup_success", gnb->state.ng_setup_success ? 1 : 0)) { cJSON_Delete(ng); cJSON_Delete(g); oom = true; break; }

            cJSON_AddItemToObjectCS(g, "ng", ng);
        }

        /* supported_ta_list */
        {
            cJSON *tas = cJSON_CreateArray();
            if (!tas) { cJSON_Delete(g); oom = true; break; }

            bool inner_oom = false;
            int t;

            for (t = 0; t < gnb->num_of_supported_ta_list; t++) {
                const ogs_uint24_t tac = gnb->supported_ta_list[t].tac;
                const int nbp = gnb->supported_ta_list[t].num_of_bplmn_list;

                cJSON *ta = cJSON_CreateObject();
                if (!ta) { inner_oom = true; break; }

                char tac_hex[7]; snprintf(tac_hex, sizeof tac_hex, "%06x", (unsigned)u24_to_u32(tac));
                if (!cJSON_AddStringToObject(ta, "tac", tac_hex)) { cJSON_Delete(ta); inner_oom = true; break; }

                cJSON *bplmns = cJSON_CreateArray();
                if (!bplmns) { cJSON_Delete(ta); inner_oom = true; break; }

                bool inner2_oom = false;
                int p;

                for (p = 0; p < nbp; p++) {
                    const ogs_plmn_id_t *bp_plmn = &gnb->supported_ta_list[t].bplmn_list[p].plmn_id;
                    const int ns = gnb->supported_ta_list[t].bplmn_list[p].num_of_s_nssai;
                    const ogs_s_nssai_t *sn = gnb->supported_ta_list[t].bplmn_list[p].s_nssai;

                    cJSON *bp = cJSON_CreateObject();
                    if (!bp) { inner2_oom = true; break; }

                    if (add_plmn_string(bp, "plmn", bp_plmn) < 0) { cJSON_Delete(bp); inner2_oom = true; break; }

                    cJSON *sns = cJSON_CreateArray();
                    if (!sns) { cJSON_Delete(bp); inner2_oom = true; break; }

                    bool inner3_oom = false;
                    int i;

                    for (i = 0; i < ns; i++) {
                        cJSON *o = cJSON_CreateObject();
                        if (!o) { inner3_oom = true; break; }

                        if (!cJSON_AddNumberToObject(o, "sst", (double)(unsigned)sn[i].sst)) { cJSON_Delete(o); inner3_oom = true; break; }
                        char sd[7]; snprintf(sd, sizeof sd, "%06x", (unsigned)u24_to_u32(sn[i].sd));
                        if (!cJSON_AddStringToObject(o, "sd", sd)) { cJSON_Delete(o); inner3_oom = true; break; }

                        cJSON_AddItemToArray(sns, o);
                    }

                    if (inner3_oom) { cJSON_Delete(sns); cJSON_Delete(bp); inner2_oom = true; break; }

                    cJSON_AddItemToObjectCS(bp, "snssai", sns);
                    cJSON_AddItemToArray(bplmns, bp);
                }

                if (inner2_oom) { cJSON_Delete(bplmns); cJSON_Delete(ta); inner_oom = true; break; }

                cJSON_AddItemToObjectCS(ta, "bplmns", bplmns);
                cJSON_AddItemToArray(tas, ta);
            }

            if (inner_oom) { cJSON_Delete(tas); cJSON_Delete(g); oom = true; break; }

            cJSON_AddItemToObjectCS(g, "supported_ta_list", tas);
        }

        /* num_connected_ues */
        {
            size_t num = 0; ran_ue_t *r = NULL; ogs_list_for_each(&((amf_gnb_t*)gnb)->ran_ue_list, r) num++;
            if (!cJSON_AddNumberToObject(g, "num_connected_ues", (double)num)) { cJSON_Delete(g); oom = true; break; }
        }

        /* attach completed item */
        cJSON_AddItemToArray(items, g);
        emitted++;
        idx++;
    }

    json_pager_add_trailing(root, no_paging, page, page_size, emitted, has_next && !oom,"/gnb-info", oom);

    return json_pager_finalize(root, buf, buflen);
}