/* $OpenBSD: bss_acpt.c,v 1.33 2025/06/02 12:18:21 jsg Exp $ */
/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
 * All rights reserved.
 *
 * This package is an SSL implementation written
 * by Eric Young (eay@cryptsoft.com).
 * The implementation was written so as to conform with Netscapes SSL.
 * 
 * This library is free for commercial and non-commercial use as long as
 * the following conditions are aheared to.  The following conditions
 * apply to all code found in this distribution, be it the RC4, RSA,
 * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
 * included with this distribution is covered by the same copyright terms
 * except that the holder is Tim Hudson (tjh@cryptsoft.com).
 * 
 * Copyright remains Eric Young's, and as such any Copyright notices in
 * the code are not to be removed.
 * If this package is used in a product, Eric Young should be given attribution
 * as the author of the parts of the library used.
 * This can be in the form of a textual message at program startup or
 * in documentation (online or textual) provided with the package.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. 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.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *    "This product includes cryptographic software written by
 *     Eric Young (eay@cryptsoft.com)"
 *    The word 'cryptographic' can be left out if the rouines from the library
 *    being used are not cryptographic related :-).
 * 4. If you include any Windows specific code (or a derivative thereof) from 
 *    the apps directory (application code) you must include an acknowledgement:
 *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
 * 
 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``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 AUTHOR 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.
 * 
 * The licence and distribution terms for any publically available version or
 * derivative of this code cannot be changed.  i.e. this code cannot simply be
 * copied and put under another distribution licence
 * [including the GNU Public Licence.]
 */

#include <sys/socket.h>

#include <errno.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>

#include <openssl/bio.h>
#include <openssl/buffer.h>

#include "bio_local.h"
#include "err_local.h"

#define SOCKET_PROTOCOL IPPROTO_TCP

typedef struct bio_accept_st {
        int state;
        char *param_addr;

        int accept_sock;
        int accept_nbio;

        char *addr;
        int nbio;
        /* If 0, it means normal, if 1, do a connect on bind failure,
         * and if there is no-one listening, bind with SO_REUSEADDR.
         * If 2, always use SO_REUSEADDR. */
        int bind_mode;
        BIO *bio_chain;
} BIO_ACCEPT;

static int acpt_write(BIO *h, const char *buf, int num);
static int acpt_read(BIO *h, char *buf, int size);
static int acpt_puts(BIO *h, const char *str);
static long acpt_ctrl(BIO *h, int cmd, long arg1, void *arg2);
static int acpt_new(BIO *h);
static int acpt_free(BIO *data);
static int acpt_state(BIO *b, BIO_ACCEPT *c);
static void acpt_close_socket(BIO *data);
static BIO_ACCEPT *BIO_ACCEPT_new(void );
static void BIO_ACCEPT_free(BIO_ACCEPT *a);

#define ACPT_S_BEFORE                   1
#define ACPT_S_GET_ACCEPT_SOCKET        2
#define ACPT_S_OK                       3

static const BIO_METHOD methods_acceptp = {
        .type = BIO_TYPE_ACCEPT,
        .name = "socket accept",
        .bwrite = acpt_write,
        .bread = acpt_read,
        .bputs = acpt_puts,
        .ctrl = acpt_ctrl,
        .create = acpt_new,
        .destroy = acpt_free
};

const BIO_METHOD *
BIO_s_accept(void)
{
        return (&methods_acceptp);
}
LCRYPTO_ALIAS(BIO_s_accept);

static int
acpt_new(BIO *bi)
{
        BIO_ACCEPT *ba;

        bi->init = 0;
        bi->num = -1;
        bi->flags = 0;
        if ((ba = BIO_ACCEPT_new()) == NULL)
                return (0);
        bi->ptr = (char *)ba;
        ba->state = ACPT_S_BEFORE;
        bi->shutdown = 1;
        return (1);
}

static BIO_ACCEPT *
BIO_ACCEPT_new(void)
{
        BIO_ACCEPT *ret;

        if ((ret = calloc(1, sizeof(BIO_ACCEPT))) == NULL)
                return (NULL);
        ret->accept_sock = -1;
        ret->bind_mode = BIO_BIND_NORMAL;
        return (ret);
}

static void
BIO_ACCEPT_free(BIO_ACCEPT *a)
{
        if (a == NULL)
                return;

        free(a->param_addr);
        free(a->addr);
        BIO_free(a->bio_chain);
        free(a);
}

static void
acpt_close_socket(BIO *bio)
{
        BIO_ACCEPT *c;

        c = (BIO_ACCEPT *)bio->ptr;
        if (c->accept_sock != -1) {
                shutdown(c->accept_sock, SHUT_RDWR);
                close(c->accept_sock);
                c->accept_sock = -1;
                bio->num = -1;
        }
}

static int
acpt_free(BIO *a)
{
        BIO_ACCEPT *data;

        if (a == NULL)
                return (0);
        data = (BIO_ACCEPT *)a->ptr;

        if (a->shutdown) {
                acpt_close_socket(a);
                BIO_ACCEPT_free(data);
                a->ptr = NULL;
                a->flags = 0;
                a->init = 0;
        }
        return (1);
}

static int
acpt_state(BIO *b, BIO_ACCEPT *c)
{
        BIO *bio = NULL, *dbio;
        int s = -1;
        int i;

again:
        switch (c->state) {
        case ACPT_S_BEFORE:
                if (c->param_addr == NULL) {
                        BIOerror(BIO_R_NO_ACCEPT_PORT_SPECIFIED);
                        return (-1);
                }
                s = BIO_get_accept_socket(c->param_addr, c->bind_mode);
                if (s == -1)
                        return (-1);

                if (c->accept_nbio) {
                        if (!BIO_socket_nbio(s, 1)) {
                                close(s);
                                BIOerror(BIO_R_ERROR_SETTING_NBIO_ON_ACCEPT_SOCKET);
                                return (-1);
                        }
                }
                c->accept_sock = s;
                b->num = s;
                c->state = ACPT_S_GET_ACCEPT_SOCKET;
                return (1);
                /* break; */
        case ACPT_S_GET_ACCEPT_SOCKET:
                if (b->next_bio != NULL) {
                        c->state = ACPT_S_OK;
                        goto again;
                }
                BIO_clear_retry_flags(b);
                b->retry_reason = 0;
                i = BIO_accept(c->accept_sock, &(c->addr));

                /* -2 return means we should retry */
                if (i == -2) {
                        BIO_set_retry_special(b);
                        b->retry_reason = BIO_RR_ACCEPT;
                        return -1;
                }

                if (i < 0)
                        return (i);

                bio = BIO_new_socket(i, BIO_CLOSE);
                if (bio == NULL)
                        goto err;

                BIO_set_callback(bio, BIO_get_callback(b));
                BIO_set_callback_arg(bio, BIO_get_callback_arg(b));

                if (c->nbio) {
                        if (!BIO_socket_nbio(i, 1)) {
                                BIOerror(BIO_R_ERROR_SETTING_NBIO_ON_ACCEPTED_SOCKET);
                                goto err;
                        }
                }

                /* If the accept BIO has an bio_chain, we dup it and
                 * put the new socket at the end. */
                if (c->bio_chain != NULL) {
                        if ((dbio = BIO_dup_chain(c->bio_chain)) == NULL)
                                goto err;
                        if (!BIO_push(dbio, bio))
                                goto err;
                        bio = dbio;
                }
                if (BIO_push(b, bio) == NULL)
                        goto err;

                c->state = ACPT_S_OK;
                return (1);

err:
                if (bio != NULL)
                        BIO_free(bio);
                return (0);
                /* break; */
        case ACPT_S_OK:
                if (b->next_bio == NULL) {
                        c->state = ACPT_S_GET_ACCEPT_SOCKET;
                        goto again;
                }
                return (1);
                /* break; */
        default:
                return (0);
                /* break; */
        }
}

static int
acpt_read(BIO *b, char *out, int outl)
{
        int ret = 0;
        BIO_ACCEPT *data;

        BIO_clear_retry_flags(b);
        data = (BIO_ACCEPT *)b->ptr;

        while (b->next_bio == NULL) {
                ret = acpt_state(b, data);
                if (ret <= 0)
                        return (ret);
        }

        ret = BIO_read(b->next_bio, out, outl);
        BIO_copy_next_retry(b);
        return (ret);
}

static int
acpt_write(BIO *b, const char *in, int inl)
{
        int ret;
        BIO_ACCEPT *data;

        BIO_clear_retry_flags(b);
        data = (BIO_ACCEPT *)b->ptr;

        while (b->next_bio == NULL) {
                ret = acpt_state(b, data);
                if (ret <= 0)
                        return (ret);
        }

        ret = BIO_write(b->next_bio, in, inl);
        BIO_copy_next_retry(b);
        return (ret);
}

static long
acpt_ctrl(BIO *b, int cmd, long num, void *ptr)
{
        int *ip;
        long ret = 1;
        BIO_ACCEPT *data;
        char **pp;

        data = (BIO_ACCEPT *)b->ptr;

        switch (cmd) {
        case BIO_CTRL_RESET:
                ret = 0;
                data->state = ACPT_S_BEFORE;
                acpt_close_socket(b);
                b->flags = 0;
                break;
        case BIO_C_DO_STATE_MACHINE:
                /* use this one to start the connection */
                ret = (long)acpt_state(b, data);
                break;
        case BIO_C_SET_ACCEPT:
                if (ptr != NULL) {
                        if (num == 0) {
                                b->init = 1;
                                free(data->param_addr);
                                data->param_addr = strdup(ptr);
                        } else if (num == 1) {
                                data->accept_nbio = (ptr != NULL);
                        } else if (num == 2) {
                                BIO_free(data->bio_chain);
                                data->bio_chain = (BIO *)ptr;
                        }
                }
                break;
        case BIO_C_SET_NBIO:
                data->nbio = (int)num;
                break;
        case BIO_C_SET_FD:
                b->init = 1;
                b->num= *((int *)ptr);
                data->accept_sock = b->num;
                data->state = ACPT_S_GET_ACCEPT_SOCKET;
                b->shutdown = (int)num;
                b->init = 1;
                break;
        case BIO_C_GET_FD:
                if (b->init) {
                        ip = (int *)ptr;
                        if (ip != NULL)
                                *ip = data->accept_sock;
                        ret = data->accept_sock;
                } else
                        ret = -1;
                break;
        case BIO_C_GET_ACCEPT:
                if (b->init) {
                        if (ptr != NULL) {
                                pp = (char **)ptr;
                                *pp = data->param_addr;
                        } else
                                ret = -1;
                } else
                        ret = -1;
                break;
        case BIO_CTRL_GET_CLOSE:
                ret = b->shutdown;
                break;
        case BIO_CTRL_SET_CLOSE:
                b->shutdown = (int)num;
                break;
        case BIO_CTRL_PENDING:
        case BIO_CTRL_WPENDING:
                ret = 0;
                break;
        case BIO_CTRL_FLUSH:
                break;
        case BIO_C_SET_BIND_MODE:
                data->bind_mode = (int)num;
                break;
        case BIO_C_GET_BIND_MODE:
                ret = (long)data->bind_mode;
                break;
        case BIO_CTRL_DUP:
/*              dbio=(BIO *)ptr;
                if (data->param_port) EAY EAY
                        BIO_set_port(dbio,data->param_port);
                if (data->param_hostname)
                        BIO_set_hostname(dbio,data->param_hostname);
                BIO_set_nbio(dbio,data->nbio);
*/
                break;

        default:
                ret = 0;
                break;
        }
        return (ret);
}

static int
acpt_puts(BIO *bp, const char *str)
{
        int n, ret;

        n = strlen(str);
        ret = acpt_write(bp, str, n);
        return (ret);
}

BIO *
BIO_new_accept(const char *str)
{
        BIO *ret;

        ret = BIO_new(BIO_s_accept());
        if (ret == NULL)
                return (NULL);
        if (BIO_set_accept_port(ret, str))
                return (ret);
        else {
                BIO_free(ret);
                return (NULL);
        }
}
LCRYPTO_ALIAS(BIO_new_accept);