ng_atmllc.c

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/*-
 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
 *
 * Copyright (c) 2003-2004 Benno Rice <benno@eloquent.com.au>
 * 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR  ``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.
 *
 * $FreeBSD$
 */
 
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/socket.h>
#include <sys/sockio.h>
 
#include <netgraph/ng_message.h>
#include <netgraph/netgraph.h>
#include <netgraph/ng_atmllc.h>
 
#include <net/if.h>
#include <net/ethernet.h>       /* for M_HASFCS and ETHER_HDR_LEN */
 
#define NG_ATMLLC_HEADER                "\252\252\3\0\200\302"
#define NG_ATMLLC_HEADER_LEN            (sizeof(struct atmllc))
#define NG_ATMLLC_TYPE_ETHERNET_FCS     0x0001
#define NG_ATMLLC_TYPE_FDDI_FCS         0x0004
#define NG_ATMLLC_TYPE_ETHERNET_NOFCS   0x0007
#define NG_ATMLLC_TYPE_FDDI_NOFCS       0x000A
 
struct ng_atmllc_priv {
        hook_p          atm;
        hook_p          ether;
        hook_p          fddi;
};
 
struct atmllc {
        uint8_t         llchdr[6];      /* aa.aa.03.00.00.00 */
        uint8_t         type[2];        /* "ethernet" type */
};
 
/* ATM_LLC macros: note type code in host byte order */
#define ATM_LLC_TYPE(X) (((X)->type[0] << 8) | ((X)->type[1]))
#define ATM_LLC_SETTYPE(X, V) do {              \
        (X)->type[0] = ((V) >> 8) & 0xff;       \
        (X)->type[1] = ((V) & 0xff);            \
    } while (0)
 
/* Netgraph methods. */
static ng_constructor_t         ng_atmllc_constructor;
static ng_shutdown_t            ng_atmllc_shutdown;
static ng_rcvmsg_t              ng_atmllc_rcvmsg;
static ng_newhook_t             ng_atmllc_newhook;
static ng_rcvdata_t             ng_atmllc_rcvdata;
static ng_disconnect_t          ng_atmllc_disconnect;
 
static struct ng_type ng_atmllc_typestruct = {
        .version =      NG_ABI_VERSION, 
        .name =         NG_ATMLLC_NODE_TYPE,
        .constructor =  ng_atmllc_constructor,
        .rcvmsg =       ng_atmllc_rcvmsg,
        .shutdown =     ng_atmllc_shutdown,
        .newhook =      ng_atmllc_newhook,
        .rcvdata =      ng_atmllc_rcvdata,
        .disconnect =   ng_atmllc_disconnect,
};
NETGRAPH_INIT(atmllc, &ng_atmllc_typestruct);
 
static int
ng_atmllc_constructor(node_p node)
{
        struct  ng_atmllc_priv *priv;
 
        priv = malloc(sizeof(*priv), M_NETGRAPH, M_WAITOK | M_ZERO);
        NG_NODE_SET_PRIVATE(node, priv);
 
        return (0);
}
 
static int
ng_atmllc_rcvmsg(node_p node, item_p item, hook_p lasthook)
{
        struct  ng_mesg *msg;
        int     error;
 
        error = 0;
        NGI_GET_MSG(item, msg);
        msg->header.flags |= NGF_RESP;
        NG_RESPOND_MSG(error, node, item, msg);
        return (error);
}
 
static int
ng_atmllc_shutdown(node_p node)
{
        struct  ng_atmllc_priv *priv;
 
        priv = NG_NODE_PRIVATE(node);
 
        free(priv, M_NETGRAPH);
 
        NG_NODE_UNREF(node);
 
        return (0);
}
 
static int
ng_atmllc_newhook(node_p node, hook_p hook, const char *name)
{
        struct  ng_atmllc_priv *priv;
 
        priv = NG_NODE_PRIVATE(node);
 
        if (strcmp(name, NG_ATMLLC_HOOK_ATM) == 0) {
                if (priv->atm != NULL) {
                        return (EISCONN);
                }
                priv->atm = hook;
        } else if (strcmp(name, NG_ATMLLC_HOOK_ETHER) == 0) {
                if (priv->ether != NULL) {
                        return (EISCONN);
                }
                priv->ether = hook;
        } else if (strcmp(name, NG_ATMLLC_HOOK_FDDI) == 0) {
                if (priv->fddi != NULL) {
                        return (EISCONN);
                }
                priv->fddi = hook;
        } else {
                return (EINVAL);
        }
 
        return (0);
}
 
static int
ng_atmllc_rcvdata(hook_p hook, item_p item)
{
        struct  ng_atmllc_priv *priv;
        struct  mbuf *m;
        struct  atmllc *hdr;
        hook_p  outhook;
        u_int   padding;
        int     error;
 
        priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
        NGI_GET_M(item, m);
        outhook = NULL;
        padding = 0;
 
        if (hook == priv->atm) {
                /* Ditch the pseudoheader. */
                hdr = mtod(m, struct atmllc *);
                /* m_adj(m, sizeof(struct atm_pseudohdr)); */
 
                /*
                 * Make sure we have the LLC and ethernet headers.
                 * The ethernet header size is slightly larger than the FDDI
                 * header, which is convenient.
                 */
                if (m->m_len < sizeof(struct atmllc) + ETHER_HDR_LEN) {
                        m = m_pullup(m, sizeof(struct atmllc) + ETHER_HDR_LEN);
                        if (m == NULL) {
                                NG_FREE_ITEM(item);
                                return (ENOMEM);
                        }
                }
 
                /* Decode the LLC header. */
                hdr = mtod(m, struct atmllc *);
                if (ATM_LLC_TYPE(hdr) == NG_ATMLLC_TYPE_ETHERNET_NOFCS) {
                        m->m_flags &= ~M_HASFCS;
                        outhook = priv->ether;
                        padding = 2;
                } else if (ATM_LLC_TYPE(hdr) == NG_ATMLLC_TYPE_ETHERNET_FCS) {
                        m->m_flags |= M_HASFCS;
                        outhook = priv->ether;
                        padding = 2;
                } else if (ATM_LLC_TYPE(hdr) == NG_ATMLLC_TYPE_FDDI_NOFCS) {
                        m->m_flags &= ~M_HASFCS;
                        outhook = priv->fddi;
                        padding = 3;
                } else if (ATM_LLC_TYPE(hdr) == NG_ATMLLC_TYPE_FDDI_FCS) {
                        m->m_flags |= M_HASFCS;
                        outhook = priv->fddi;
                        padding = 3;
                } else {
                        printf("ng_atmllc: unknown type: %x\n",
                            ATM_LLC_TYPE(hdr));
                }
 
                /* Remove the LLC header and any padding*/
                m_adj(m, sizeof(struct atmllc) + padding);
        } else if (hook == priv->ether) {
                /* Add the LLC header */
                M_PREPEND(m, NG_ATMLLC_HEADER_LEN + 2, M_NOWAIT);
                if (m == NULL) {
                        printf("ng_atmllc: M_PREPEND failed\n");
                        NG_FREE_ITEM(item);
                        return (ENOMEM);
                }
                hdr = mtod(m, struct atmllc *);
                bzero((void *)hdr, sizeof(struct atmllc) + 2);
                bcopy(NG_ATMLLC_HEADER, hdr->llchdr, 6);
                if ((m->m_flags & M_HASFCS) != 0) {
                        ATM_LLC_SETTYPE(hdr, NG_ATMLLC_TYPE_ETHERNET_FCS);
                } else {
                        ATM_LLC_SETTYPE(hdr, NG_ATMLLC_TYPE_ETHERNET_NOFCS);
                }
                outhook = priv->atm;
        } else if (hook == priv->fddi) {
                /* Add the LLC header */
                M_PREPEND(m, NG_ATMLLC_HEADER_LEN + 3, M_NOWAIT);
                if (m == NULL) {
                        printf("ng_atmllc: M_PREPEND failed\n");
                        NG_FREE_ITEM(item);
                        return (ENOMEM);
                }
                hdr = mtod(m, struct atmllc *);
                bzero((void *)hdr, sizeof(struct atmllc) + 3);
                bcopy(NG_ATMLLC_HEADER, hdr->llchdr, 6);
                if ((m->m_flags & M_HASFCS) != 0) {
                        ATM_LLC_SETTYPE(hdr, NG_ATMLLC_TYPE_FDDI_FCS);
                } else {
                        ATM_LLC_SETTYPE(hdr, NG_ATMLLC_TYPE_FDDI_NOFCS);
                }
                outhook = priv->atm;
        }
 
        if (outhook == NULL) {
                NG_FREE_M(m);
                NG_FREE_ITEM(item);
                return (0);
        }
 
        NG_FWD_NEW_DATA(error, item, outhook, m);
        return (error);
}
 
static int
ng_atmllc_disconnect(hook_p hook)
{
        node_p  node;
        struct  ng_atmllc_priv *priv;
 
        node = NG_HOOK_NODE(hook);
        priv = NG_NODE_PRIVATE(node);
 
        if (hook == priv->atm) {
                priv->atm = NULL;
        } else if (hook == priv->ether) {
                priv->ether = NULL;
        } else if (hook == priv->fddi) {
                priv->fddi = NULL;
        }
 
        if (NG_NODE_NUMHOOKS(node) == 0 && NG_NODE_IS_VALID(node)) {
                ng_rmnode_self(node);
        }
 
        return (0);
}