/*      $NetBSD: if_media.c,v 1.1 1997/03/17 02:55:15 thorpej Exp $     */
/* $FreeBSD: src/sys/net/if_media.c,v 1.21.2.1 2006/03/17 20:17:43 glebius Exp $ */

/*-
 * 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 <string.h>

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/socket.h>
#include <sys/sockio.h>
#include <sys/malloc.h>
#include <sys/sysctl.h>

#include <net/if.h>
#include <net/if_media.h>

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

//#define IFMEDIA_DEBUG
#ifdef IFMEDIA_DEBUG
#   define TRACE(x...) dprintf(x)

static  void ifmedia_printword(int);
#else
#   define TRACE(x...) ;
#endif

static struct ifmedia_entry *ifmedia_match(struct ifmedia *ifm,
        int flags, int mask);

/*
 * Initialize if_media struct for a specific interface instance.
 */
void
ifmedia_init(ifm, dontcare_mask, change_callback, status_callback)
        struct ifmedia *ifm;
        int dontcare_mask;
        ifm_change_cb_t change_callback;
        ifm_stat_cb_t status_callback;
{

        LIST_INIT(&ifm->ifm_list);
        ifm->ifm_cur = NULL;
        ifm->ifm_media = 0;
        ifm->ifm_mask = dontcare_mask;          /* IF don't-care bits */
        ifm->ifm_change = change_callback;
        ifm->ifm_status = status_callback;
}

void
ifmedia_removeall(ifm)
        struct ifmedia *ifm;
{
        struct ifmedia_entry *entry;

        for (entry = LIST_FIRST(&ifm->ifm_list); entry;
             entry = LIST_FIRST(&ifm->ifm_list)) {
                LIST_REMOVE(entry, ifm_list);
                kernel_free(entry, M_IFADDR);
        }
}

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

#ifdef IFMEDIA_DEBUG
        if (ifm == NULL) {
                TRACE("ifmedia_add: null ifm\n");
                return;
        }
        TRACE("ifmedia_add: Adding Entry...\n");
        ifmedia_printword(mword);
#endif

        entry = kernel_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;

        LIST_INSERT_HEAD(&ifm->ifm_list, entry, ifm_list);
}

/*
 * Add an array of media configurations to the list of
 * supported media for a specific interface instance.
 */
void
ifmedia_list_add(ifm, lp, count)
        struct ifmedia *ifm;
        struct ifmedia_entry *lp;
        int count;
{
        int i;

        for (i = 0; i < count; i++)
                ifmedia_add(ifm, lp[i].ifm_media, lp[i].ifm_data,
                    lp[i].ifm_aux);
}

/*
 * 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(ifm, target)
        struct ifmedia *ifm;
        int target;

{
        struct ifmedia_entry *match;

        match = ifmedia_match(ifm, target, ifm->ifm_mask);

        if (match == NULL) {
                TRACE("ifmedia_set: no match for 0x%x/0x%x\n",
                        target, ~ifm->ifm_mask);
                panic("ifmedia_set");
        }
        ifm->ifm_cur = match;

#ifdef IFMEDIA_DEBUG
        TRACE("ifmedia_set: target ");
        ifmedia_printword(target);
        TRACE("ifmedia_set: setting to ");
        ifmedia_printword(ifm->ifm_cur->ifm_media);
#endif
}

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

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

        switch (cmd) {

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

                match = ifmedia_match(ifm, newmedia, ifm->ifm_mask);
                if (match == NULL) {
                        TRACE("ifmedia_ioctl: no media found for 0x%x\n",
                                newmedia);
                        return (ENXIO);
                }

                /*
                 * If no change, we're done.
                 * XXX Automedia may invole software intervention.
                 *     Keep going in case the 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))
                        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
                TRACE("ifmedia_ioctl: switching %s to ",
                        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;
                error = (*ifm->ifm_change)(ifp);
                if (error) {
                        ifm->ifm_cur = oldentry;
                        ifm->ifm_media = oldmedia;
                }
                break;
        }

        /*
         * Get list of available media and current media on interface.
         */
        case  SIOCGIFMEDIA:
        {
                struct ifmedia_entry *ep;
                int *kptr, count;
                int usermax;    /* user requested max */

                kptr = NULL;            /* XXX gcc */

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

                count = 0;
                usermax = 0;

                /*
                 * If there are more interfaces on the list, count
                 * them.  This allows the caller to set ifmr->ifm_count
                 * to 0 on the first call to know how much space to
                 * allocate.
                 */
                LIST_FOREACH(ep, &ifm->ifm_list, ifm_list)
                        usermax++;

                /*
                 * Don't allow the user to ask for too many
                 * or a negative number.
                 */
                if (ifmr->ifm_count > usermax)
                        ifmr->ifm_count = usermax;
                else if (ifmr->ifm_count < 0)
                        return (EINVAL);

                if (ifmr->ifm_count != 0) {
                        kptr = (int *)kernel_malloc(ifmr->ifm_count * sizeof(int),
                            M_TEMP, M_NOWAIT);

                        if (kptr == NULL)
                                return (ENOMEM);
                        /*
                         * Get the media words from the interface's list.
                         */
                        ep = LIST_FIRST(&ifm->ifm_list);
                        for (; ep != NULL && count < ifmr->ifm_count;
                            ep = LIST_NEXT(ep, ifm_list), count++)
                                kptr[count] = ep->ifm_media;

                        if (ep != NULL)
                                error = E2BIG;  /* oops! */
                } else {
                        count = usermax;
                }

                /*
                 * We do the copyout on E2BIG, because that's
                 * just our way of telling userland that there
                 * are more.  This is the behavior I've observed
                 * under BSD/OS 3.0
                 */
                sticky = error;
                if ((error == 0 || error == E2BIG) && ifmr->ifm_count != 0) {
#if 0
                        error = copyout((caddr_t)kptr,
                            (caddr_t)ifmr->ifm_ulist,
                            ifmr->ifm_count * sizeof(int));
#endif
                        /* this ioctl() is only called from within the kernel -hugo */
                        memcpy(kptr, ifmr->ifm_ulist, ifmr->ifm_count * sizeof(int));
                }

                if (error == 0)
                        error = sticky;

                if (ifmr->ifm_count != 0)
                        kernel_free(kptr, M_TEMP);

                ifmr->ifm_count = count;
                break;
        }

        default:
                return (EINVAL);
        }

        return (error);
}

/*
 * Find media entry matching a given ifm word.
 *
 */
static struct ifmedia_entry *
ifmedia_match(ifm, target, mask)
        struct ifmedia *ifm;
        int target;
        int mask;
{
        struct ifmedia_entry *match, *next;

        match = NULL;
        mask = ~mask;

        LIST_FOREACH(next, &ifm->ifm_list, ifm_list) {
                if ((next->ifm_media & mask) == (target & mask)) {
#ifdef IFMEDIA_DEBUG
                        if (match) {
                                TRACE("ifmedia_match: multiple match for "
                                        "0x%x/0x%x\n", target, mask);
                        }
#endif
                        match = next;
                }
        }

        return match;
}

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

uint64_t
ifmedia_baudrate(int 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
struct ifmedia_description ifm_type_descriptions[] =
    IFM_TYPE_DESCRIPTIONS;

struct ifmedia_description ifm_subtype_ethernet_descriptions[] =
    IFM_SUBTYPE_ETHERNET_DESCRIPTIONS;

struct ifmedia_description ifm_subtype_ethernet_option_descriptions[] =
    IFM_SUBTYPE_ETHERNET_OPTION_DESCRIPTIONS;

struct ifmedia_description ifm_subtype_ieee80211_descriptions[] =
    IFM_SUBTYPE_IEEE80211_DESCRIPTIONS;

struct ifmedia_description ifm_subtype_ieee80211_option_descriptions[] =
    IFM_SUBTYPE_IEEE80211_OPTION_DESCRIPTIONS;

struct ifmedia_description ifm_subtype_ieee80211_mode_descriptions[] =
    IFM_SUBTYPE_IEEE80211_MODE_DESCRIPTIONS;

struct ifmedia_description ifm_subtype_atm_descriptions[] =
    IFM_SUBTYPE_ATM_DESCRIPTIONS;

struct ifmedia_description ifm_subtype_atm_option_descriptions[] =
    IFM_SUBTYPE_ATM_OPTION_DESCRIPTIONS;

struct ifmedia_description ifm_subtype_shared_descriptions[] =
    IFM_SUBTYPE_SHARED_DESCRIPTIONS;

struct ifmedia_description ifm_shared_option_descriptions[] =
    IFM_SHARED_OPTION_DESCRIPTIONS;

struct ifmedia_type_to_subtype {
        struct ifmedia_description *subtypes;
        struct ifmedia_description *options;
        struct ifmedia_description *modes;
};

/* must be in the same order as IFM_TYPE_DESCRIPTIONS */
struct ifmedia_type_to_subtype ifmedia_types_to_subtypes[] = {
        {
          &ifm_subtype_ethernet_descriptions[0],
          &ifm_subtype_ethernet_option_descriptions[0],
          NULL,
        },
        {
          &ifm_subtype_ieee80211_descriptions[0],
          &ifm_subtype_ieee80211_option_descriptions[0],
          &ifm_subtype_ieee80211_mode_descriptions[0]
        },
        {
          &ifm_subtype_atm_descriptions[0],
          &ifm_subtype_atm_option_descriptions[0],
          NULL,
        },
};

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

        /* Find the top-level interface type. */
        for (desc = ifm_type_descriptions, ttos = ifmedia_types_to_subtypes;
            desc->ifmt_string != NULL; desc++, ttos++)
                if (IFM_TYPE(ifmw) == desc->ifmt_word)
                        break;
        if (desc->ifmt_string == NULL) {
                TRACE("  Type: <unknown type>\n");
                return;
        }
        TRACE("  Type: %s\n", desc->ifmt_string);

        /* Any mode. */
        for (desc = ttos->modes; desc && desc->ifmt_string != NULL; desc++)
                if (IFM_MODE(ifmw) == desc->ifmt_word) {
                        if (desc->ifmt_string != NULL)
                                TRACE("  Mode: %s\n", desc->ifmt_string);
                        break;
                }

        /*
         * Check for the shared subtype descriptions first, then the
         * type-specific ones.
         */
        for (desc = ifm_subtype_shared_descriptions;
            desc->ifmt_string != NULL; desc++)
                if (IFM_SUBTYPE(ifmw) == desc->ifmt_word)
                        goto got_subtype;

        for (desc = ttos->subtypes; desc->ifmt_string != NULL; desc++)
                if (IFM_SUBTYPE(ifmw) == desc->ifmt_word)
                        break;
        if (desc->ifmt_string == NULL) {
                TRACE("  SubType: <unknown>\n");
                return;
        }

 got_subtype:
        TRACE("  SubType: %s\n", desc->ifmt_string);

        /*
         * Look for shared options.
         */
        for (desc = ifm_shared_option_descriptions;
            desc->ifmt_string != NULL; desc++) {
                if (ifmw & desc->ifmt_word) {
                        TRACE("  Shared Option[%d]: %s\n", seen_option++,
                                desc->ifmt_string);
                }
        }

        /*
         * Look for subtype-specific options.
         */
        for (desc = ttos->options; desc->ifmt_string != NULL; desc++) {
                if (ifmw & desc->ifmt_word) {
                        TRACE("  SubType Option[%d]: %s\n", seen_option++,
                                desc->ifmt_string);
                }
        }
}
#endif /* IFMEDIA_DEBUG */