/*      $NetBSD: ofnet.c,v 1.63 2020/01/29 06:18:17 thorpej Exp $       */

/*
 * Copyright (C) 1995, 1996 Wolfgang Solfrank.
 * Copyright (C) 1995, 1996 TooLs GmbH.
 * 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. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by TooLs GmbH.
 * 4. The name of TooLs GmbH may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``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 TOOLS GMBH 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/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: ofnet.c,v 1.63 2020/01/29 06:18:17 thorpej Exp $");

#include "ofnet.h"
#include "opt_inet.h"

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/callout.h>
#include <sys/device.h>
#include <sys/disk.h>
#include <sys/ioctl.h>
#include <sys/mbuf.h>
#include <sys/socket.h>
#include <sys/syslog.h>

#include <net/if.h>
#include <net/if_ether.h>
#include <net/bpf.h>

#ifdef INET
#include <netinet/in.h>
#include <netinet/if_inarp.h>
#endif

#include <dev/ofw/openfirm.h>

struct ofnet_softc {
        device_t sc_dev;
        int sc_phandle;
        int sc_ihandle;
        struct ethercom sc_ethercom;
        struct callout sc_callout;
};

static int ofnet_match (device_t, cfdata_t, void *);
static void ofnet_attach (device_t, device_t, void *);

CFATTACH_DECL_NEW(ofnet, sizeof(struct ofnet_softc),
    ofnet_match, ofnet_attach, NULL, NULL);

static void ofnet_read (struct ofnet_softc *);
static void ofnet_timer (void *);
static void ofnet_init (struct ofnet_softc *);
static void ofnet_stop (struct ofnet_softc *);

static void ofnet_start (struct ifnet *);
static int ofnet_ioctl (struct ifnet *, u_long, void *);
static void ofnet_watchdog (struct ifnet *);

static int
ofnet_match(device_t parent, cfdata_t match, void *aux)
{
        struct ofbus_attach_args *oba = aux;
        char type[32];
        int l;

        if (strcmp(oba->oba_busname, "ofw"))
                return (0);
        if ((l = OF_getprop(oba->oba_phandle, "device_type", type,
            sizeof type - 1)) < 0)
                return 0;
        if (l >= sizeof type)
                return 0;
        type[l] = 0;
        if (strcmp(type, "network"))
                return 0;
        return 1;
}

static void
ofnet_attach(device_t parent, device_t self, void *aux)
{
        struct ofnet_softc *of = device_private(self);
        struct ifnet *ifp = &of->sc_ethercom.ec_if;
        struct ofbus_attach_args *oba = aux;
        char path[256];
        int l;
        u_int8_t myaddr[ETHER_ADDR_LEN];

        of->sc_dev = self;

        of->sc_phandle = oba->oba_phandle;

        if ((l = OF_package_to_path(oba->oba_phandle, path,
            sizeof path - 1)) < 0 ||
            l >= sizeof path ||
            (path[l] = 0, !(of->sc_ihandle = OF_open(path))))
                panic("ofnet_attach: unable to open");
        if (OF_getprop(oba->oba_phandle, "mac-address", myaddr,
            sizeof myaddr) < 0)
                panic("ofnet_attach: no mac-address");
        printf(": address %s\n", ether_sprintf(myaddr));

        callout_init(&of->sc_callout, 0);

        strlcpy(ifp->if_xname, device_xname(of->sc_dev), IFNAMSIZ);
        ifp->if_softc = of;
        ifp->if_start = ofnet_start;
        ifp->if_ioctl = ofnet_ioctl;
        ifp->if_watchdog = ofnet_watchdog;
        ifp->if_flags = IFF_BROADCAST | IFF_SIMPLEX;
        IFQ_SET_READY(&ifp->if_snd);

        if_attach(ifp);
        ether_ifattach(ifp, myaddr);
}

static char buf[ETHER_MAX_LEN];

static void
ofnet_read(struct ofnet_softc *of)
{
        struct ifnet *ifp = &of->sc_ethercom.ec_if;
        struct mbuf *m, **mp, *head;
        int s, l, len;
        char *bufp;

        s = splnet();

        for (;;) {
                len = OF_read(of->sc_ihandle, buf, sizeof buf);
                if (len == -2 || len == 0)
                        break;
                if (len < sizeof(struct ether_header)) {
                        if_statinc(ifp, if_ierrors);
                        continue;
                }
                bufp = buf;

                /*
                 * We don't know if the interface included the FCS
                 * or not.  For now, assume that it did if we got
                 * a packet length that looks like it could include
                 * the FCS.
                 *
                 * XXX Yuck.
                 */
                if (len > ETHER_MAX_LEN - ETHER_CRC_LEN)
                        len = ETHER_MAX_LEN - ETHER_CRC_LEN;

                /* Allocate a header mbuf */
                MGETHDR(m, M_DONTWAIT, MT_DATA);
                if (m == 0) {
                        if_statinc(ifp, if_ierrors);
                        continue;
                }
                m_set_rcvif(m, ifp);
                m->m_pkthdr.len = len;

                l = MHLEN;
                head = 0;
                mp = &head;

                while (len > 0) {
                        if (head) {
                                MGET(m, M_DONTWAIT, MT_DATA);
                                if (m == 0) {
                                        if_statinc(ifp, if_ierrors);
                                        m_freem(head);
                                        head = 0;
                                        break;
                                }
                                l = MLEN;
                        }
                        if (len >= MINCLSIZE) {
                                MCLGET(m, M_DONTWAIT);
                                if ((m->m_flags & M_EXT) == 0) {
                                        if_statinc(ifp, if_ierrors);
                                        m_free(m);
                                        m_freem(head);
                                        head = 0;
                                        break;
                                }
                                l = MCLBYTES;
                        }

                        /*
                         * Make sure the data after the Ethernet header
                         * is aligned.
                         *
                         * XXX Assumes the device is an ethernet, but
                         * XXX then so does other code in this driver.
                         */
                        if (head == NULL) {
                                char *newdata = (char *)ALIGN(m->m_data +
                                      sizeof(struct ether_header)) -
                                    sizeof(struct ether_header);
                                l -= newdata - m->m_data;
                                m->m_data = newdata;
                        }

                        m->m_len = l = uimin(len, l);
                        memcpy(mtod(m, char *), bufp, l);
                        bufp += l;
                        len -= l;
                        *mp = m;
                        mp = &m->m_next;
                }
                if (head == 0)
                        continue;

                if_percpuq_enqueue(ifp->if_percpuq, head);
        }
        splx(s);
}

static void
ofnet_timer(void *arg)
{
        struct ofnet_softc *of = arg;

        ofnet_read(of);
        callout_reset(&of->sc_callout, 1, ofnet_timer, of);
}

static void
ofnet_init(struct ofnet_softc *of)
{
        struct ifnet *ifp = &of->sc_ethercom.ec_if;

        if (ifp->if_flags & IFF_RUNNING)
                return;

        ifp->if_flags |= IFF_RUNNING;
        /* Start reading from interface */
        ofnet_timer(of);
        /* Attempt to start output */
        ofnet_start(ifp);
}

static void
ofnet_stop(struct ofnet_softc *of)
{
        callout_stop(&of->sc_callout);
        of->sc_ethercom.ec_if.if_flags &= ~IFF_RUNNING;
}

static void
ofnet_start(struct ifnet *ifp)
{
        struct ofnet_softc *of = ifp->if_softc;
        struct mbuf *m, *m0;
        char *bufp;
        int len;

        if (!(ifp->if_flags & IFF_RUNNING))
                return;

        for (;;) {
                /* First try reading any packets */
                ofnet_read(of);

                /* Now get the first packet on the queue */
                IFQ_DEQUEUE(&ifp->if_snd, m0);
                if (!m0)
                        return;

                if (!(m0->m_flags & M_PKTHDR))
                        panic("ofnet_start: no header mbuf");
                len = m0->m_pkthdr.len;

                bpf_mtap(ifp, m0, BPF_D_OUT);

                if (len > ETHERMTU + sizeof(struct ether_header)) {
                        /* packet too large, toss it */
                        if_statinc(ifp, if_oerrors);
                        m_freem(m0);
                        continue;
                }

                for (bufp = buf; (m = m0) != NULL;) {
                        memcpy(bufp, mtod(m, char *), m->m_len);
                        bufp += m->m_len;
                        m0 = m_free(m);
                }

                /*
                 * We don't know if the interface will auto-pad for
                 * us, so make sure it's at least as large as a
                 * minimum size Ethernet packet.
                 */

                if (len < (ETHER_MIN_LEN - ETHER_CRC_LEN)) {
                        memset(bufp, 0, ETHER_MIN_LEN - ETHER_CRC_LEN - len);
                        bufp += ETHER_MIN_LEN - ETHER_CRC_LEN - len;
                } else
                        len = bufp - buf;

                if (OF_write(of->sc_ihandle, buf, len) != len)
                        if_statinc(ifp, if_oerrors);
                else
                        if_statinc(ifp, if_opackets);
        }
}

static int
ofnet_ioctl(struct ifnet *ifp, u_long cmd, void *data)
{
        struct ofnet_softc *of = ifp->if_softc;
        struct ifaddr *ifa = (struct ifaddr *)data;
        /* struct ifreq *ifr = (struct ifreq *)data; */
        int error = 0;

        switch (cmd) {
        case SIOCINITIFADDR:
                ifp->if_flags |= IFF_UP;

                switch (ifa->ifa_addr->sa_family) {
#ifdef  INET
                case AF_INET:
                        arp_ifinit(ifp, ifa);
                        break;
#endif
                default:
                        break;
                }
                ofnet_init(of);
                break;
        case SIOCSIFFLAGS:
                if ((error = ifioctl_common(ifp, cmd, data)) != 0)
                        break;
                /* XXX re-use ether_ioctl() */
                switch (ifp->if_flags & (IFF_UP|IFF_RUNNING)) {
                case IFF_RUNNING:
                        /* If interface is down, but running, stop it. */
                        ofnet_stop(of);
                        break;
                case IFF_UP:
                        /* If interface is up, but not running, start it. */
                        ofnet_init(of);
                        break;
                default:
                        /* Other flags are ignored. */
                        break;
                }
                break;
        default:
                error = ether_ioctl(ifp, cmd, data);
                break;
        }
        return error;
}

static void
ofnet_watchdog(struct ifnet *ifp)
{
        struct ofnet_softc *of = ifp->if_softc;

        log(LOG_ERR, "%s: device timeout\n", device_xname(of->sc_dev));
        if_statinc(ifp, if_oerrors);
        ofnet_stop(of);
        ofnet_init(of);
}