/*      $NetBSD: netif.c,v 1.28 2025/11/28 14:46:32 nia Exp $   */

/*
 * Copyright (c) 1993 Adam Glass
 * All rights reserved.
 *
 * 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 above 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. The name of the Author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY Adam Glass ``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 REGENTS 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 <sys/param.h>
#include <sys/cdefs.h>
#include <sys/mount.h>
#ifdef _STANDALONE
#include <lib/libkern/libkern.h>
#else
#include <string.h>
#endif

#include <netinet/in.h>
#include <netinet/in_systm.h>

#include "stand.h"
#include "netif.h"

struct iodesc sockets[SOPEN_MAX];
#ifdef NETIF_DEBUG
int netif_debug = 0;
#endif

/*
 * netif_init:
 *
 * initialize the generic network interface layer
 */

void
netif_init(void)
{
        struct netif_driver *drv;
        int d, i;

#ifdef NETIF_DEBUG
        if (netif_debug)
                printf("%s: called\n", __func__);
#endif
        for (d = 0; d < n_netif_drivers; d++) {
                drv = netif_drivers[d];
                for (i = 0; i < drv->netif_nifs; i++)
                        drv->netif_ifs[i].dif_used = 0;
        }
}

int     netif_match(struct netif *, void *);

int
netif_match(struct netif *nif, void *machdep_hint)
{
        struct netif_driver *drv = nif->nif_driver;

#if 0
        if (netif_debug)
                printf("%s%d: %s (%d)\n", drv->netif_bname,
                    nif->nif_unit, __func__, nif->nif_sel);
#endif
        return drv->netif_match(nif, machdep_hint);
}

struct netif *
netif_select(void *machdep_hint)
{
        int d, u, s;
        struct netif_driver *drv;
        struct netif cur_if;
        static struct netif best_if;
        int best_val;
        int val;

        best_val = 0;
        best_if.nif_driver = NULL;

#ifdef NETIF_DEBUG
        if (netif_debug)
                printf("%s: %d interfaces\n", __func__, n_netif_drivers);
#endif

        for (d = 0; d < n_netif_drivers; d++) {
                cur_if.nif_driver = netif_drivers[d];
                drv = cur_if.nif_driver;

                for (u = 0; u < drv->netif_nifs; u++) {
                        cur_if.nif_unit = u;

#ifdef NETIF_DEBUG
                        if (netif_debug)
                                printf("\t%s%d:", drv->netif_bname,
                                    cur_if.nif_unit);
#endif

                        for (s = 0; s < drv->netif_ifs[u].dif_nsel; s++) {
                                cur_if.nif_sel = s;

                                if (drv->netif_ifs[u].dif_used & (1 << s)) {
#ifdef NETIF_DEBUG
                                        if (netif_debug)
                                                printf(" [%d used]", s);
#endif
                                        continue;
                                }

                                val = netif_match(&cur_if, machdep_hint);
#ifdef NETIF_DEBUG
                                if (netif_debug)
                                        printf(" [%d -> %d]", s, val);
#endif
                                if (val > best_val) {
                                        best_val = val;
                                        best_if = cur_if;
                                }
                        }
#ifdef NETIF_DEBUG
                        if (netif_debug)
                                printf("\n");
#endif
                }
        }

        if (best_if.nif_driver == NULL)
                return NULL;

        best_if.nif_driver->
            netif_ifs[best_if.nif_unit].dif_used |= (1 << best_if.nif_sel);

#ifdef NETIF_DEBUG
        if (netif_debug)
                printf("%s: %s%d(%d) wins\n", __func__,
                        best_if.nif_driver->netif_bname,
                        best_if.nif_unit, best_if.nif_sel);
#endif
        return &best_if;
}

int
netif_probe(struct netif *nif, void *machdep_hint)
{
        struct netif_driver *drv = nif->nif_driver;

#ifdef NETIF_DEBUG
        if (netif_debug)
                printf("%s%d: %s\n", drv->netif_bname, nif->nif_unit, __func__);
#endif
        return drv->netif_probe(nif, machdep_hint);
}

void
netif_attach(struct netif *nif, struct iodesc *desc, void *machdep_hint)
{
        struct netif_driver *drv = nif->nif_driver;

#ifdef NETIF_DEBUG
        if (netif_debug)
                printf("%s%d: %s\n", drv->netif_bname, nif->nif_unit, __func__);
#endif
        desc->io_netif = nif;
#ifdef PARANOID
        if (drv->netif_init == NULL)
                panic("%s%d: no netif_init support", drv->netif_bname,
                    nif->nif_unit);
#endif
        drv->netif_init(desc, machdep_hint);
        (void)memset(drv->netif_ifs[nif->nif_unit].dif_stats, 0,
            sizeof(struct netif_stats));
}

void
netif_detach(struct netif *nif)
{
        struct netif_driver *drv = nif->nif_driver;

#ifdef NETIF_DEBUG
        if (netif_debug)
                printf("%s%d: %s\n", drv->netif_bname, nif->nif_unit, __func__);
#endif
#ifdef PARANOID
        if (drv->netif_end == NULL)
                panic("%s%d: no netif_end support", drv->netif_bname,
                    nif->nif_unit);
#endif
        drv->netif_end(nif);
}

ssize_t
netif_get(struct iodesc *desc, void *pkt, size_t len, saseconds_t timo)
{
        struct netif *nif = desc->io_netif;
        struct netif_driver *drv = nif->nif_driver;
        ssize_t rv;

#ifdef NETIF_DEBUG
        if (netif_debug)
                printf("%s%d: %s\n", drv->netif_bname, nif->nif_unit, __func__);
#endif
#ifdef PARANOID
        if (drv->netif_get == NULL)
                panic("%s%d: no %s support", drv->netif_bname,
                    nif->nif_unit, __func__);
#endif
        rv = drv->netif_get(desc, pkt, len, timo);
#ifdef NETIF_DEBUG
        if (netif_debug)
                printf("%s%d: %s returning %zd\n", drv->netif_bname,
                    nif->nif_unit, __func__, rv);
#endif
        return rv;
}

ssize_t
netif_put(struct iodesc *desc, void *pkt, size_t len)
{
        struct netif *nif = desc->io_netif;
        struct netif_driver *drv = nif->nif_driver;
        ssize_t rv;

#ifdef NETIF_DEBUG
        if (netif_debug)
                printf("%s%d: %s\n", drv->netif_bname, nif->nif_unit, __func__);
#endif
#ifdef PARANOID
        if (drv->netif_put == NULL)
                panic("%s%d: no netif_put support", drv->netif_bname,
                    nif->nif_unit);
#endif
        rv = drv->netif_put(desc, pkt, len);
#ifdef NETIF_DEBUG
        if (netif_debug)
                printf("%s%d: %s returning %zd\n", drv->netif_bname,
                    nif->nif_unit, __func__, rv);
#endif
        return rv;
}

struct iodesc *
socktodesc(int sock)
{
#if !defined(LIBSA_NO_FD_CHECKING)
        if (sock >= SOPEN_MAX) {
                errno = EBADF;
                return NULL;
        }
#endif
        return &sockets[sock];
}

int
netif_open(void *machdep_hint)
{
        int fd;
        struct iodesc *s;
        struct netif *nif;

        /* find a free socket */
        for (fd = 0, s = sockets; fd < SOPEN_MAX; fd++, s++)
                if (s->io_netif == (struct netif *)0)
                        goto fnd;
        errno = EMFILE;
        return -1;

fnd:
        (void)memset(s, 0, sizeof(*s));
        netif_init();
        nif = netif_select(machdep_hint);
        if (!nif) {
                errno = ENXIO;
                return -1;
        }
        if (netif_probe(nif, machdep_hint)) {
                printf("%s: couldn't probe %s%d\n", __func__,
                    nif->nif_driver->netif_bname, nif->nif_unit);
                errno = EINVAL;
                return -1;
        }
        netif_attach(nif, s, machdep_hint);

        return fd;
}

int
netif_close(int sock)
{
#if !defined(LIBSA_NO_FD_CHECKING)
        if (sock >= SOPEN_MAX) {
                errno = EBADF;
                return -1;
        }
#endif
        netif_detach(sockets[sock].io_netif);
        sockets[sock].io_netif = (struct netif *)0;

        return 0;
}