/*

 * Copyright (c) 2025, Net-snmp authors

 * All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions are met:

 *

 * * Redistributions of source code must retain the above copyright notice, this

 *   list of conditions and the following disclaimer.

 *

 * * Redistributions in binary form must reproduce the above copyright notice,

 *   this list of conditions and the following disclaimer in the documentation

 *   and/or other materials provided with the distribution.

 *

 * * Neither the name of the copyright holder nor the names of its

 *   contributors may be used to endorse or promote products derived from

 *   this software without specific prior written permission.

 *

 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"

 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE

 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE

 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL

 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR

 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER

 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,

 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE

 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

 */

#include <net-snmp/net-snmp-config.h>

#include <net-snmp/net-snmp-includes.h>

#include "../../apps/snmptrapd_handlers.h"

#include "ada_fuzz_header.h"

static netsnmp_session *add_session(netsnmp_transport *t)

{

    netsnmp_session session;

    snmp_sess_init(&session);

    session.peername = SNMP_DEFAULT_PEERNAME;

    session.version = SNMP_DEFAULT_VERSION;

    session.community_len = SNMP_DEFAULT_COMMUNITY_LEN;

    session.retries = SNMP_DEFAULT_RETRIES;

    session.timeout = SNMP_DEFAULT_TIMEOUT;

    session.callback = snmp_input;

    session.callback_magic = t;

    session.authenticator = NULL;

    session.isAuthoritative = SNMP_SESS_UNKNOWNAUTH;

    return snmp_add(&session, t, NULL, NULL);

}

int LLVMFuzzerInitialize(int *argc, char ***argv) {

    if (getenv("NETSNMP_DEBUGGING") != NULL) {

        snmp_enable_stderrlog();

        snmp_set_do_debugging(1);

        debug_register_tokens("sess_process_packet");

    }

    return 0;

}

int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {

    netsnmp_transport *transport = NULL;

    netsnmp_session *session = NULL;

    const unsigned short pkt_len = size;

    const void *const pkt = data;

    int skt = -1;

    int ret = 1;

    if (pkt_len == 0)

        goto cleanup;

    netsnmp_ds_set_string(NETSNMP_DS_LIBRARY_ID, NETSNMP_DS_LIB_MIBDIRS, "mibs");

    netsnmp_ds_set_boolean(NETSNMP_DS_LIBRARY_ID,

                           NETSNMP_DS_LIB_DONT_PERSIST_STATE, 1);

    netsnmp_ds_set_string(NETSNMP_DS_LIBRARY_ID, NETSNMP_DS_LIB_PERSISTENT_DIR,

                          "/tmp");

    init_snmp("snmptrapd");

    transport = netsnmp_transport_open_server("trap_fuzzer", "127.0.0.1:7365");

    if (!transport) {

        fprintf(stderr, "Error: failed to open Net-SNMP transport.\n");

        goto cleanup;

    }

    session = add_session(transport);

    if (!session) {

        fprintf(stderr, "Error: failed to add Net-SNMP session.\n");

        goto cleanup;

    }

    skt = socket(AF_INET, SOCK_DGRAM, 0);

    if (skt < 0) {

        perror("socket()");

        goto shutdown;

    }

    struct sockaddr_in addr = {

        .sin_family = AF_INET,

        .sin_port = htons(7365),

        .sin_addr = { htonl(INADDR_LOOPBACK) }

    };

    if (connect(skt, &addr, sizeof(addr)) < 0) {

        perror("connect()");

        goto shutdown;

    }

    if (send(skt, pkt, pkt_len, 0) < 0) {

        perror("send()");

        goto shutdown;

    }

    {

        fd_set readfds,writefds,exceptfds;

        int numfds = 0, block = 0;

        struct timeval timeout;

        FD_ZERO(&readfds);

        FD_ZERO(&writefds);

        FD_ZERO(&exceptfds);

        timerclear(&timeout);

        timeout.tv_sec = 5;

        snmp_select_info(&numfds, &readfds, &timeout, &block);

        if (select(numfds, &readfds, &writefds, &exceptfds, &timeout) > 0)

            snmp_read(&readfds);

    }

    ret = 0;

shutdown:

    snmp_shutdown("snmptrapd");

cleanup:

    if (skt >= 0)

        close(skt);

    if (session)

        snmp_close(session);

    return ret;

}