/*
 * ng_eiface.c
 *
 * Copyright (c) 1999-2000, Vitaly V Belekhov
 * 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 unmodified, 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 AUTHOR 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 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.
 *
 *      $Id: ng_eiface.c,v 1.14 2000/03/15 12:28:44 vitaly Exp $
 * $FreeBSD: src/sys/netgraph/ng_eiface.c,v 1.4.2.5 2002/12/17 21:47:48 julian Exp $
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/errno.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/sockio.h>
#include <sys/socket.h>
#include <sys/syslog.h>
#include <sys/serialize.h>
#include <sys/thread2.h>

#include <net/if.h>
#include <net/if_types.h>
#include <net/ifq_var.h>
#include <net/netisr.h>
#include <net/route.h>


#include <netgraph/ng_message.h>
#include <netgraph/netgraph.h>
#include <netgraph/ng_parse.h>
#include "ng_eiface.h"

#include <net/bpf.h>
#include <net/ethernet.h>
#include <net/if_arp.h>

static const struct ng_parse_struct_field ng_eiface_par_fields[]
        = NG_EIFACE_PAR_FIELDS;

static const struct ng_parse_type ng_eiface_par_type = {
        &ng_parse_struct_type,
        &ng_eiface_par_fields
};

static const struct ng_cmdlist ng_eiface_cmdlist[] = {
        {
          NGM_EIFACE_COOKIE,
          NGM_EIFACE_SET,
          "set",
          &ng_eiface_par_type,
          NULL
        },
        { 0 }
};

/* Node private data */
struct ng_eiface_private {
        struct arpcom   arpcom;         /* per-interface network data */
        struct  ifnet *ifp;             /* This interface */
        node_p  node;                   /* Our netgraph node */
        hook_p  ether;                  /* Hook for ethernet stream */
        struct  private *next;          /* When hung on the free list */
};
typedef struct ng_eiface_private *priv_p;

/* Interface methods */
static void     ng_eiface_init(void *xsc);
static void     ng_eiface_start(struct ifnet *ifp, struct ifaltq_subque *);
static int      ng_eiface_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data,
                                struct ucred *cr);
#ifdef DEBUG
static void     ng_eiface_print_ioctl(struct ifnet *ifp, int cmd, caddr_t data);
#endif

/* Netgraph methods */
static ng_constructor_t ng_eiface_constructor;
static ng_rcvmsg_t      ng_eiface_rcvmsg;
static ng_shutdown_t    ng_eiface_rmnode;
static ng_newhook_t     ng_eiface_newhook;
static ng_rcvdata_t     ng_eiface_rcvdata;
static ng_connect_t     ng_eiface_connect;
static ng_disconnect_t  ng_eiface_disconnect;

/* Node type descriptor */
static struct ng_type typestruct = {
        NG_VERSION,
        NG_EIFACE_NODE_TYPE,
        NULL,
        ng_eiface_constructor,
        ng_eiface_rcvmsg,
        ng_eiface_rmnode,
        ng_eiface_newhook,
        NULL,
        ng_eiface_connect,
        ng_eiface_rcvdata,
        ng_eiface_rcvdata,
        ng_eiface_disconnect,
        ng_eiface_cmdlist
};
NETGRAPH_INIT(eiface, &typestruct);

static char ng_eiface_ifname[] = NG_EIFACE_EIFACE_NAME;
static int ng_eiface_next_unit;

/************************************************************************
                        INTERFACE STUFF
 ************************************************************************/

/*
 * Process an ioctl for the virtual interface
 */
static int
ng_eiface_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data, struct ucred *cr)
{
        struct ifreq *const ifr = (struct ifreq *) data;
        int error = 0;

#ifdef DEBUG
        ng_eiface_print_ioctl(ifp, cmd, data);
#endif
        crit_enter();
        switch (cmd) {

        /* These two are mostly handled at a higher layer */
        case SIOCSIFADDR:
                error = ether_ioctl(ifp, cmd, data);
                break;
        case SIOCGIFADDR:
                break;

        /* Set flags */
        case SIOCSIFFLAGS:
                /*
                 * If the interface is marked up and stopped, then start it.
                 * If it is marked down and running, then stop it.
                 */
                if (ifr->ifr_flags & IFF_UP) {
                        if (!(ifp->if_flags & IFF_RUNNING)) {
                                ifq_clr_oactive(&ifp->if_snd);
                                ifp->if_flags |= IFF_RUNNING;
                        }
                } else {
                        if (ifp->if_flags & IFF_RUNNING) {
                                ifp->if_flags &= ~IFF_RUNNING;
                                ifq_clr_oactive(&ifp->if_snd);
                        }
                }
                break;

        /* Set the interface MTU */
        case SIOCSIFMTU:
                if (ifr->ifr_mtu > NG_EIFACE_MTU_MAX
                    || ifr->ifr_mtu < NG_EIFACE_MTU_MIN)
                        error = EINVAL;
                else
                        ifp->if_mtu = ifr->ifr_mtu;
                break;

        /* Stuff that's not supported */
        case SIOCADDMULTI:
        case SIOCDELMULTI:
                error = 0;
                break;
        case SIOCSIFPHYS:
                error = EOPNOTSUPP;
                break;

        default:
                error = EINVAL;
                break;
        }
        crit_exit();
        return (error);
}

static void
ng_eiface_init(void *xsc)
{
        priv_p sc = xsc;
        struct ifnet *ifp = sc->ifp;

        crit_enter();

        ifp->if_flags |= IFF_RUNNING;
        ifq_clr_oactive(&ifp->if_snd);

        crit_exit();

}

/*
 * This routine is called to deliver a packet out the interface.
 * We simply relay the packet to
 * the ether hook, if it is connected.
 */

static void
ng_eiface_start(struct ifnet *ifp, struct ifaltq_subque *ifsq __unused)
{
        const priv_p priv = (priv_p) ifp->if_softc;
        meta_p meta = NULL;
        int len, error = 0;
        struct mbuf *m;

        /* Check interface flags */
        if ((ifp->if_flags & (IFF_UP|IFF_RUNNING)) != (IFF_UP|IFF_RUNNING))
                return;

        /* Don't do anything if output is active */
        if(ifq_is_oactive(&ifp->if_snd))
                return;

        ifq_set_oactive(&ifp->if_snd);

        /*
         * Grab a packet to transmit.
         */
        m = ifq_dequeue(&ifp->if_snd);

        /* If there's nothing to send, return. */
        if(m == NULL)
        {
                ifq_clr_oactive(&ifp->if_snd);
                return;
        }

        BPF_MTAP(ifp, m);

        /* Copy length before the mbuf gets invalidated */
        len = m->m_pkthdr.len;

        /* Send packet; if hook is not connected, mbuf will get freed. */
        NG_SEND_DATA(error, priv->ether, m, meta);

        /* Update stats */
        if (error == 0) {
                IFNET_STAT_INC(ifp, obytes, len);
                IFNET_STAT_INC(ifp, opackets, 1);
        }

        ifq_clr_oactive(&ifp->if_snd);

        return;
}

#ifdef DEBUG
/*
 * Display an ioctl to the virtual interface
 */

static void
ng_eiface_print_ioctl(struct ifnet *ifp, int cmd, caddr_t data)
{
        char   *str;

        switch (cmd & IOC_DIRMASK) {
        case IOC_VOID:
                str = "IO";
                break;
        case IOC_OUT:
                str = "IOR";
                break;
        case IOC_IN:
                str = "IOW";
                break;
        case IOC_INOUT:
                str = "IORW";
                break;
        default:
                str = "IO??";
        }
        log(LOG_DEBUG, "%s: %s('%c', %d, char[%d])\n",
               ifp->if_xname,
               str,
               IOCGROUP(cmd),
               cmd & 0xff,
               IOCPARM_LEN(cmd));
}
#endif /* DEBUG */

/************************************************************************
                        NETGRAPH NODE STUFF
 ************************************************************************/

/*
 * Constructor for a node
 */
static int
ng_eiface_constructor(node_p *nodep)
{
        struct ifnet *ifp;
        node_p node;
        priv_p priv;
        int error = 0;

        /* Allocate node and interface private structures */
        priv = kmalloc(sizeof(*priv), M_NETGRAPH, M_WAITOK | M_ZERO);

        ifp = &(priv->arpcom.ac_if);

        /* Link them together */
        ifp->if_softc = priv;
        priv->ifp = ifp;

        /* Call generic node constructor */
        if ((error = ng_make_node_common(&typestruct, nodep))) {
                kfree(priv, M_NETGRAPH);
                return (error);
        }
        node = *nodep;

        /* Link together node and private info */
        node->private = priv;
        priv->node = node;

        /* Initialize interface structure */
        if_initname(ifp, ng_eiface_ifname, ng_eiface_next_unit++);
        ifp->if_init = ng_eiface_init;
        ifp->if_start = ng_eiface_start;
        ifp->if_ioctl = ng_eiface_ioctl;
        ifp->if_watchdog = NULL;
        ifq_set_maxlen(&ifp->if_snd, IFQ_MAXLEN);
        ifp->if_flags = (IFF_SIMPLEX | IFF_BROADCAST | IFF_MULTICAST);

        /* Give this node name *
        bzero(ifname, sizeof(ifname));
        ksprintf(ifname, "if%s", ifp->if_xname);
        ng_name_node(node, ifname);
        */

        /* Attach the interface */
        ether_ifattach(ifp, priv->arpcom.ac_enaddr, NULL);

        /* Done */
        return (0);
}

/*
 * Give our ok for a hook to be added
 */
static int
ng_eiface_newhook(node_p node, hook_p hook, const char *name)
{
        priv_p priv = node->private;

        if (strcmp(name, NG_EIFACE_HOOK_ETHER))
                return (EPFNOSUPPORT);
        if (priv->ether != NULL)
                return (EISCONN);
        priv->ether = hook;
        hook->private = &priv->ether;

        return (0);
}

/*
 * Receive a control message
 */
static int
ng_eiface_rcvmsg(node_p node, struct ng_mesg *msg,
                const char *retaddr, struct ng_mesg **rptr)
{
        const priv_p priv = node->private;
        struct ifnet *const ifp = priv->ifp;
        struct ng_mesg *resp = NULL;
        int error = 0;

        switch (msg->header.typecookie) {
        case NGM_EIFACE_COOKIE:
                switch (msg->header.cmd) {

                case NGM_EIFACE_SET:
                    {
                      struct ng_eiface_par *eaddr;

                      if (msg->header.arglen != sizeof(struct ng_eiface_par)) 
                        {
                          error = EINVAL;
                          break;
                        }
                      eaddr = (struct ng_eiface_par *)(msg->data);

                      priv->arpcom.ac_enaddr[0] = eaddr->oct0;
                      priv->arpcom.ac_enaddr[1] = eaddr->oct1;
                      priv->arpcom.ac_enaddr[2] = eaddr->oct2;
                      priv->arpcom.ac_enaddr[3] = eaddr->oct3;
                      priv->arpcom.ac_enaddr[4] = eaddr->oct4;
                      priv->arpcom.ac_enaddr[5] = eaddr->oct5;

                      break;
                    }

                case NGM_EIFACE_GET_IFNAME:
                    {
                        struct ng_eiface_ifname *arg;

                        NG_MKRESPONSE(resp, msg, sizeof(*arg), M_NOWAIT);
                        if (resp == NULL) {
                                error = ENOMEM;
                                break;
                        }
                        arg = (struct ng_eiface_ifname *) resp->data;
                        ksprintf(arg->ngif_name,
                            "%s", ifp->if_xname); /* XXX: strings */
                        break;
                    }

                case NGM_EIFACE_GET_IFADDRS:
                    {
                        struct ifaddr_container *ifac;
                        caddr_t ptr;
                        int buflen;

#define SA_SIZE(s)      RT_ROUNDUP((s)->sa_len)

                        /* Determine size of response and allocate it */
                        buflen = 0;
                        TAILQ_FOREACH(ifac, &ifp->if_addrheads[mycpuid],
                                      ifa_link) {
                                /* Ignore marker */
                                if (ifac->ifa->ifa_addr->sa_family == AF_UNSPEC)
                                         continue;
                                buflen += SA_SIZE(ifac->ifa->ifa_addr);
                        }
                        NG_MKRESPONSE(resp, msg, buflen, M_NOWAIT);
                        if (resp == NULL) {
                                error = ENOMEM;
                                break;
                        }

                        /* Add addresses */
                        ptr = resp->data;
                        TAILQ_FOREACH(ifac, &ifp->if_addrheads[mycpuid],
                                      ifa_link) {
                                struct ifaddr *ifa = ifac->ifa;
                                const int len = SA_SIZE(ifa->ifa_addr);

                                /* Ignore marker */
                                if (ifa->ifa_addr->sa_family == AF_UNSPEC)
                                         continue;

                                if (buflen < len) {
                                        log(LOG_ERR, "%s: len changed?\n",
                                            ifp->if_xname);
                                        break;
                                }
                                bcopy(ifa->ifa_addr, ptr, len);
                                ptr += len;
                                buflen -= len;
                        }
                        break;
#undef SA_SIZE
                    }

                default:
                        error = EINVAL;
                        break;
                }
                break;
        default:
                error = EINVAL;
                break;
        }
        if (rptr)
                *rptr = resp;
        else if (resp)
                kfree(resp, M_NETGRAPH);
        kfree(msg, M_NETGRAPH);
        return (error);
}

/*
 * Recive data from a hook. Pass the packet to the ether_input routine.
 */
static int
ng_eiface_rcvdata(hook_p hook, struct mbuf *m, meta_p meta)
{
        const priv_p priv = hook->node->private;
        struct ifnet *const ifp = priv->ifp;
        int error = 0;

        /* Meta-data is end its life here... */
        NG_FREE_META(meta);

        if (m == NULL) {
            kprintf("ng_eiface: mbuf is null.\n");
            return (EINVAL);
        }

        if ( !(ifp->if_flags & IFF_UP) )
                return (ENETDOWN);

        /* Note receiving interface */
        m->m_pkthdr.rcvif = ifp;

        /* Update interface stats */
        IFNET_STAT_INC(ifp, ipackets, 1);

        BPF_MTAP(ifp, m);

        ifp->if_input(ifp, m, NULL, -1);

        /* Done */
        return (error);
}

/*
 * Because the BSD networking code doesn't support the removal of
 * networking interfaces, iface nodes (once created) are persistent.
 * So this method breaks all connections and marks the interface
 * down, but does not remove the node.
 */
static int
ng_eiface_rmnode(node_p node)
{
        const priv_p priv = node->private;
        struct ifnet *const ifp = priv->ifp;

        ng_cutlinks(node);
        node->flags &= ~NG_INVALID;
        ifnet_serialize_all(ifp);
        ifp->if_flags &= ~(IFF_UP | IFF_RUNNING);
        ifq_clr_oactive(&ifp->if_snd);
        ifnet_deserialize_all(ifp);
        return (0);
}


/*
 * This is called once we've already connected a new hook to the other node.
 * It gives us a chance to balk at the last minute.
 */
static int
ng_eiface_connect(hook_p hook)
{
        /* be really amiable and just say "YUP that's OK by me! " */
        return (0);
}

/*
 * Hook disconnection
 */
static int
ng_eiface_disconnect(hook_p hook)
{
        const priv_p priv = hook->node->private;

        priv->ether = NULL;
        return (0);
}