/*      $OpenBSD: if_media.c,v 1.40 2025/07/07 02:28:50 jsg Exp $       */
/*      $NetBSD: if_media.c,v 1.10 2000/03/13 23:52:39 soren Exp $      */

/*-
 * Copyright (c) 1998 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility,
 * NASA Ames Research Center.
 *
 * 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
 */

/*
 * Copyright (c) 1997
 *      Jonathan Stone and Jason R. Thorpe.  All rights reserved.
 *
 * This software is derived from information provided by Matt Thomas.
 *
 * 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. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by Jonathan Stone
 *      and Jason R. Thorpe for the NetBSD Project.
 * 4. The names of the authors may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``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 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.
 */

/*
 * BSD/OS-compatible network interface media selection.
 *
 * Where it is safe to do so, this code strays slightly from the BSD/OS
 * design.  Software which uses the API (device drivers, basically)
 * shouldn't notice any difference.
 *
 * Many thanks to Matt Thomas for providing the information necessary
 * to implement this interface.
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/errno.h>
#include <sys/ioctl.h>
#include <sys/malloc.h>
#include <sys/mutex.h>

#include <net/if.h>
#ifdef IFMEDIA_DEBUG
#include <net/if_var.h>
#endif
#include <net/if_media.h>

/*
 * Compile-time options:
 * IFMEDIA_DEBUG:
 *      turn on implementation-level debug printfs.
 *      Useful for debugging newly-ported  drivers.
 */

#ifdef IFMEDIA_DEBUG
int     ifmedia_debug = 0;
static  void ifmedia_printword(uint64_t);
#endif

struct mutex ifmedia_mtx = MUTEX_INITIALIZER(IPL_NET);

struct  ifmedia_entry *ifmedia_get(struct ifmedia *, uint64_t, uint64_t);

/*
 * Initialize if_media struct for a specific interface instance.
 */
void
ifmedia_init(struct ifmedia *ifm, uint64_t dontcare_mask,
    ifm_change_cb_t change_callback, ifm_stat_cb_t status_callback)
{
        TAILQ_INIT(&ifm->ifm_list);
        ifm->ifm_nwords = 0;
        ifm->ifm_cur = NULL;
        ifm->ifm_media = 0;
        ifm->ifm_mask = dontcare_mask;          /* IF don't-care bits */
        ifm->ifm_change_cb = change_callback;
        ifm->ifm_status_cb = status_callback;
}

/*
 * Add a media configuration to the list of supported media
 * for a specific interface instance.
 */
void
ifmedia_add(struct ifmedia *ifm, uint64_t mword, int data, void *aux)
{
        struct ifmedia_entry *entry;

#ifdef IFMEDIA_DEBUG
        if (ifmedia_debug) {
                if (ifm == NULL) {
                        printf("%s: null ifm\n", __func__);
                        return;
                }
                printf("%s: adding entry for ", __func__);
                ifmedia_printword(mword);
        }
#endif

        entry = malloc(sizeof(*entry), M_IFADDR, M_NOWAIT);
        if (entry == NULL)
                panic("ifmedia_add: can't malloc entry");

        entry->ifm_media = mword;
        entry->ifm_data = data;
        entry->ifm_aux = aux;

        mtx_enter(&ifmedia_mtx);
        TAILQ_INSERT_TAIL(&ifm->ifm_list, entry, ifm_list);
        ifm->ifm_nwords++;
        mtx_leave(&ifmedia_mtx);
}

/*
 * Set the default active media.
 *
 * Called by device-specific code which is assumed to have already
 * selected the default media in hardware.  We do _not_ call the
 * media-change callback.
 */
void
ifmedia_set(struct ifmedia *ifm, uint64_t target)
{
        struct ifmedia_entry *match;

        mtx_enter(&ifmedia_mtx);
        match = ifmedia_get(ifm, target, ifm->ifm_mask);

        /*
         * If we didn't find the requested media, then we try to fall
         * back to target-type (IFM_ETHER, e.g.) | IFM_NONE.  If that's
         * not on the list, then we add it and set the media to it.
         *
         * Since ifmedia_set is almost always called with IFM_AUTO or
         * with a known-good media, this really should only occur if we:
         *
         * a) didn't find any PHYs, or
         * b) didn't find an autoselect option on the PHY when the
         *    parent ethernet driver expected to.
         *
         * In either case, it makes sense to select no media.
         */
        if (match == NULL) {
                printf("%s: no match for 0x%llx/0x%llx\n", __func__,
                    target, ~ifm->ifm_mask);
                target = (target & IFM_NMASK) | IFM_NONE;
                match = ifmedia_get(ifm, target, ifm->ifm_mask);
                if (match == NULL) {
                        mtx_leave(&ifmedia_mtx);
                        ifmedia_add(ifm, target, 0, NULL);
                        mtx_enter(&ifmedia_mtx);
                        match = ifmedia_get(ifm, target, ifm->ifm_mask);
                        if (match == NULL) {
                                mtx_leave(&ifmedia_mtx);
                                panic("ifmedia_set failed");
                        }
                }
        }
        ifm->ifm_cur = match;
        mtx_leave(&ifmedia_mtx);

#ifdef IFMEDIA_DEBUG
        if (ifmedia_debug) {
                printf("%s: target ", __func__);
                ifmedia_printword(target);
                printf("%s: setting to ", __func__);
                ifmedia_printword(ifm->ifm_cur->ifm_media);
        }
#endif
}

/*
 * Device-independent media ioctl support function.
 */
int
ifmedia_ioctl(struct ifnet *ifp, struct ifreq *ifr, struct ifmedia *ifm,
    u_long cmd)
{
        struct ifmedia_entry *match;
        int error = 0;

        if (ifp == NULL || ifr == NULL || ifm == NULL)
                return (EINVAL);

        switch (cmd) {

        /*
         * Set the current media.
         */
        case SIOCSIFMEDIA:
        {
                struct ifmedia_entry *oldentry;
                uint64_t oldmedia;
                uint64_t newmedia = ifr->ifr_media;

                mtx_enter(&ifmedia_mtx);
                match = ifmedia_get(ifm, newmedia, ifm->ifm_mask);
                if (match == NULL) {
                        mtx_leave(&ifmedia_mtx);
#ifdef IFMEDIA_DEBUG
                        if (ifmedia_debug) {
                                printf("%s: no media found for 0x%llx\n",
                                    __func__, newmedia);
                        }
#endif
                        return (EINVAL);
                }

                /*
                 * If no change, we're done.
                 * XXX Automedia may involve software intervention.
                 *     Keep going in case the connected media changed.
                 *     Similarly, if best match changed (kernel debugger?).
                 */
                if ((IFM_SUBTYPE(newmedia) != IFM_AUTO) &&
                    (newmedia == ifm->ifm_media) &&
                    (match == ifm->ifm_cur)) {
                        mtx_leave(&ifmedia_mtx);
                        return (0);
                }

                /*
                 * We found a match, now make the driver switch to it.
                 * Make sure to preserve our old media type in case the
                 * driver can't switch.
                 */
#ifdef IFMEDIA_DEBUG
                if (ifmedia_debug) {
                        printf("%s: switching %s to ", __func__,
                            ifp->if_xname);
                        ifmedia_printword(match->ifm_media);
                }
#endif
                oldentry = ifm->ifm_cur;
                oldmedia = ifm->ifm_media;
                ifm->ifm_cur = match;
                ifm->ifm_media = newmedia;
                mtx_leave(&ifmedia_mtx);

                error = (*ifm->ifm_change_cb)(ifp);
                if (error && error != ENETRESET) {
                        mtx_enter(&ifmedia_mtx);
                        if (ifm->ifm_cur == match) {
                                ifm->ifm_cur = oldentry;
                                ifm->ifm_media = oldmedia;
                        }
                        mtx_leave(&ifmedia_mtx);
                }
                break;
        }

        /*
         * Get list of available media and current media on interface.
         */
        case SIOCGIFMEDIA:
        {
                struct ifmediareq *ifmr = (struct ifmediareq *) ifr;
                size_t nwords;

                if (ifmr->ifm_count < 0)
                        return (EINVAL);

                mtx_enter(&ifmedia_mtx);
                ifmr->ifm_active = ifmr->ifm_current = ifm->ifm_cur ?
                    ifm->ifm_cur->ifm_media : IFM_NONE;
                ifmr->ifm_mask = ifm->ifm_mask;
                ifmr->ifm_status = 0;
                mtx_leave(&ifmedia_mtx);

                (*ifm->ifm_status_cb)(ifp, ifmr);

                mtx_enter(&ifmedia_mtx);
                nwords = ifm->ifm_nwords;
                mtx_leave(&ifmedia_mtx);

                if (ifmr->ifm_count == 0) {
                        ifmr->ifm_count = nwords;
                        return (0);
                }

                while (1) {
                        struct ifmedia_entry *ife;
                        uint64_t *kptr;
                        size_t ksiz;

                        kptr = mallocarray(nwords, sizeof(*kptr), M_TEMP,
                            M_WAITOK | M_ZERO);
                        ksiz = nwords * sizeof(*kptr);

                        mtx_enter(&ifmedia_mtx);
                        /* Media list might grow during malloc(). */
                        if (nwords < ifm->ifm_nwords) {
                                nwords = ifm->ifm_nwords;
                                mtx_leave(&ifmedia_mtx);
                                free(kptr, M_TEMP, ksiz);
                                continue;
                        }
                        /* Request memory too small, set error and ifm_count. */
                        if (ifmr->ifm_count < ifm->ifm_nwords) {
                                nwords = ifm->ifm_nwords;
                                mtx_leave(&ifmedia_mtx);
                                free(kptr, M_TEMP, ksiz);
                                error = E2BIG;
                                break;
                        }
                        /*
                         * Get the media words from the interface's list.
                         */
                        nwords = 0;
                        TAILQ_FOREACH(ife, &ifm->ifm_list, ifm_list) {
                                kptr[nwords++] = ife->ifm_media;
                        }
                        KASSERT(nwords == ifm->ifm_nwords);
                        mtx_leave(&ifmedia_mtx);

                        error = copyout(kptr, ifmr->ifm_ulist,
                            nwords * sizeof(*kptr));
                        free(kptr, M_TEMP, ksiz);
                        break;
                }
                ifmr->ifm_count = nwords;
                break;
        }

        default:
                return (ENOTTY);
        }

        return (error);
}

/*
 * Find media entry matching a given ifm word.  Return 1 if found.
 */
int
ifmedia_match(struct ifmedia *ifm, uint64_t target, uint64_t mask)
{
        struct ifmedia_entry *match;

        mtx_enter(&ifmedia_mtx);
        match = ifmedia_get(ifm, target, mask);
        mtx_leave(&ifmedia_mtx);

        return (match != NULL);
}

struct ifmedia_entry *
ifmedia_get(struct ifmedia *ifm, uint64_t target, uint64_t mask)
{
        struct ifmedia_entry *match, *next;

        MUTEX_ASSERT_LOCKED(&ifmedia_mtx);

        match = NULL;
        mask = ~mask;

        TAILQ_FOREACH(next, &ifm->ifm_list, ifm_list) {
                if ((next->ifm_media & mask) == (target & mask)) {
                        if (match) {
#if defined(IFMEDIA_DEBUG) || defined(DIAGNOSTIC)
                                printf("%s: multiple match for 0x%llx/0x%llx, "
                                    "selected instance %lld\n", __func__,
                                    target, mask, IFM_INST(match->ifm_media));
#endif
                                break;
                        }
                        match = next;
                }
        }

        return (match);
}

/*
 * Delete all media for a given instance.
 */
void
ifmedia_delete_instance(struct ifmedia *ifm, uint64_t inst)
{
        struct ifmedia_entry *ife, *nife;
        struct ifmedia_list ifmlist;

        TAILQ_INIT(&ifmlist);

        mtx_enter(&ifmedia_mtx);
        TAILQ_FOREACH_SAFE(ife, &ifm->ifm_list, ifm_list, nife) {
                if (inst == IFM_INST_ANY ||
                    inst == IFM_INST(ife->ifm_media)) {
                        TAILQ_REMOVE(&ifm->ifm_list, ife, ifm_list);
                        ifm->ifm_nwords--;
                        TAILQ_INSERT_TAIL(&ifmlist, ife, ifm_list);
                }
        }
        ifm->ifm_cur = NULL;
        mtx_leave(&ifmedia_mtx);

        /* Do not hold mutex longer than necessary, call free() without. */
        while((ife = TAILQ_FIRST(&ifmlist)) != NULL) {
                TAILQ_REMOVE(&ifmlist, ife, ifm_list);
                free(ife, M_IFADDR, sizeof *ife);
        }
}

/*
 * Compute the interface `baudrate' from the media, for the interface
 * metrics (used by routing daemons).
 */
const struct ifmedia_baudrate ifmedia_baudrate_descriptions[] =
    IFM_BAUDRATE_DESCRIPTIONS;

uint64_t
ifmedia_baudrate(uint64_t mword)
{
        int i;

        for (i = 0; ifmedia_baudrate_descriptions[i].ifmb_word != 0; i++) {
                if ((mword & (IFM_NMASK|IFM_TMASK)) ==
                    ifmedia_baudrate_descriptions[i].ifmb_word)
                        return (ifmedia_baudrate_descriptions[i].ifmb_baudrate);
        }

        /* Not known. */
        return (0);
}

#ifdef IFMEDIA_DEBUG

const struct ifmedia_description ifm_type_descriptions[] =
    IFM_TYPE_DESCRIPTIONS;

const struct ifmedia_description ifm_subtype_descriptions[] =
    IFM_SUBTYPE_DESCRIPTIONS;

const struct ifmedia_description ifm_option_descriptions[] =
    IFM_OPTION_DESCRIPTIONS;

/*
 * print a media word.
 */
static void
ifmedia_printword(uint64_t ifmw)
{
        const struct ifmedia_description *desc;
        uint64_t seen_option = 0;

        /* Print the top-level interface type. */
        for (desc = ifm_type_descriptions; desc->ifmt_string != NULL;
             desc++) {
                if (IFM_TYPE(ifmw) == desc->ifmt_word)
                        break;
        }
        if (desc->ifmt_string == NULL)
                printf("<unknown type> ");
        else
                printf("%s ", desc->ifmt_string);

        /* Print the subtype. */
        for (desc = ifm_subtype_descriptions; desc->ifmt_string != NULL;
             desc++) {
                if (IFM_TYPE_MATCH(desc->ifmt_word, ifmw) &&
                    IFM_SUBTYPE(desc->ifmt_word) == IFM_SUBTYPE(ifmw))
                        break;
        }
        if (desc->ifmt_string == NULL)
                printf("<unknown subtype>");
        else
                printf("%s", desc->ifmt_string);

        /* Print any options. */
        for (desc = ifm_option_descriptions; desc->ifmt_string != NULL;
             desc++) {
                if (IFM_TYPE_MATCH(desc->ifmt_word, ifmw) &&
                    (ifmw & desc->ifmt_word) != 0 &&
                    (seen_option & IFM_OPTIONS(desc->ifmt_word)) == 0) {
                        if (seen_option == 0)
                                printf(" <");
                        printf("%s%s", seen_option ? "," : "",
                            desc->ifmt_string);
                        seen_option |= IFM_OPTIONS(desc->ifmt_word);
                }
        }
        printf("%s\n", seen_option ? ">" : "");
}

#endif /* IFMEDIA_DEBUG */