/* Copyright (C) The libssh2 project and its contributors.
 *
 * SPDX-License-Identifier: BSD-3-Clause
 */
#include <assert.h>
#include <errno.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/socket.h>
#include <unistd.h>
#include <libssh2.h>
#include "testinput.h"

#define FUZZ_ASSERT(COND)                                                     \
    do {                                                                      \
        if(!(COND))                                                           \
        {                                                                     \
            fprintf(stderr, "Assertion failed: " #COND "\n%s",                \
                    strerror(errno));                                         \
            goto EXIT_LABEL;                                                  \
        }                                                                     \
    } while(0)

extern "C" int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size)
{
    int socket_fds[2] = {-1, -1};
    ssize_t written;
    int rc;
    LIBSSH2_SESSION *session = NULL;
    int handshake_completed = 0;

    rc = libssh2_init(0);

    if(rc) {
        fprintf(stderr, "libssh2 initialization failed (%d)\n", rc);
        goto EXIT_LABEL;
    }

    /* Create a socket pair so data can be sent in. */
    rc = socketpair(AF_UNIX, SOCK_STREAM, 0, socket_fds);
    FUZZ_ASSERT(rc == 0);

    written = send(socket_fds[1], data, size, 0);

    if(written != (ssize_t)size) {
        /* Handle whatever error case we're in. */
        fprintf(stderr, "send() of %zu bytes returned %zu (%d)\n",
                size,
                written,
                errno);
        goto EXIT_LABEL;
    }

    rc = shutdown(socket_fds[1], SHUT_WR);
    if(rc) {
        fprintf(stderr, "socket shutdown failed (%d)\n", rc);
        goto EXIT_LABEL;
    }

    /* Create a session and start the handshake using the fuzz data
       passed in. */
    session = libssh2_session_init();
    if(session) {
        libssh2_session_set_blocking(session, 1);
    }
    else {
        goto EXIT_LABEL;
    }

    if(libssh2_session_handshake(session, socket_fds[0])) {
        goto EXIT_LABEL;
    }

    /* If we get here the handshake actually completed. */
    handshake_completed = 1;

EXIT_LABEL:

    if(session) {
        if(handshake_completed) {
            libssh2_session_disconnect(session,
                                       "Normal Shutdown, "
                                       "Thank you for playing");
        }

        libssh2_session_free(session);
    }

    libssh2_exit();

    close(socket_fds[0]);
    close(socket_fds[1]);

    return 0;
}