/***********************************************************************
*
* if.c
*
* Implementation of user-space PPPoE redirector for Linux.
*
* Functions for opening a raw socket and reading/writing raw Ethernet frames.
*
* Copyright (C) 2000 by Roaring Penguin Software Inc.
*
* This program may be distributed according to the terms of the GNU
* General Public License, version 2 or (at your option) any later version.
*
***********************************************************************/

static char const RCSID[] =
"$Id: if.c,v 1.1 2001/12/14 02:55:20 mostrows Exp $";

#include "pppoe.h"

#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif

#ifdef HAVE_NETPACKET_PACKET_H
#include <netpacket/packet.h>
#elif defined(HAVE_LINUX_IF_PACKET_H)
#include <linux/if_packet.h>
#endif

#ifdef HAVE_NET_ETHERNET_H
#include <net/ethernet.h>
#endif

#ifdef HAVE_ASM_TYPES_H
#include <asm/types.h>
#endif

#ifdef HAVE_SYS_IOCTL_H
#include <sys/ioctl.h>
#endif

#ifdef HAVE_SYSLOG_H
#include <syslog.h>
#endif

#include <errno.h>
#include <stdlib.h>
#include <string.h>

#ifdef HAVE_NET_IF_ARP_H
#include <net/if_arp.h>
#endif

#ifdef USE_DLPI

#include <limits.h>
#include <fcntl.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/time.h>
#include <sys/stream.h>
#include <sys/stropts.h>
#include <sys/dlpi.h>
#include <sys/bufmod.h>
#include <stdio.h>
#include <signal.h>
#include <stropts.h>

/* function declarations */

void dlpromisconreq( int fd, u_long  level);
void dlinforeq(int fd);
void dlunitdatareq(int fd, u_char *addrp, int addrlen, u_long minpri, u_long maxpri, u_char *datap, int datalen);
void dlinfoack(int fd, char *bufp);
void dlbindreq(int fd, u_long sap, u_long max_conind, u_long service_mode, u_long conn_mgmt, u_long xidtest);
void dlattachreq(int fd, u_long ppa);
void dlokack(int fd, char *bufp);
void dlbindack(int fd, char *bufp);
int strioctl(int fd, int cmd, int timout, int len, char *dp);
void strgetmsg(int fd, struct strbuf *ctlp, struct strbuf *datap, int *flagsp, char *caller);
void sigalrm(int sig);
void expecting(int prim, union DL_primitives *dlp);
char *dlprim(u_long prim);

/* #define DL_DEBUG */

static	int     dl_abssaplen;
static	int     dl_saplen;
static	int 	dl_addrlen;

#endif

#ifdef USE_BPF
#include <net/bpf.h>
#include <fcntl.h>

unsigned char *bpfBuffer;	/* Packet filter buffer */
int bpfLength = 0;		/* Packet filter buffer length */
int bpfSize = 0;		/* Number of unread bytes in buffer */
int bpfOffset = 0;		/* Current offset in bpfBuffer */
#endif

/* Initialize frame types to RFC 2516 values.  Some broken peers apparently
   use different frame types... sigh... */

UINT16_t Eth_PPPOE_Discovery = ETH_PPPOE_DISCOVERY;
UINT16_t Eth_PPPOE_Session   = ETH_PPPOE_SESSION;

/**********************************************************************
*%FUNCTION: etherType
*%ARGUMENTS:
* packet -- a received PPPoE packet
*%RETURNS:
* ethernet packet type (see /usr/include/net/ethertypes.h)
*%DESCRIPTION:
* Checks the ethernet packet header to determine its type.
* We should only be receveing DISCOVERY and SESSION types if the BPF
* is set up correctly.  Logs an error if an unexpected type is received.
* Note that the ethernet type names come from "pppoe.h" and the packet
* packet structure names use the LINUX dialect to maintain consistency
* with the rest of this file.  See the BSD section of "pppoe.h" for
* translations of the data structure names.
***********************************************************************/
UINT16_t
etherType(PPPoEPacket *packet)
{
    UINT16_t type = (UINT16_t) ntohs(packet->ethHdr.h_proto);
    if (type != Eth_PPPOE_Discovery && type != Eth_PPPOE_Session) {
	syslog(LOG_ERR, "Invalid ether type 0x%x", type);
    }
    return type;
}

#ifdef USE_BPF
/**********************************************************************
*%FUNCTION: getHWaddr
*%ARGUMENTS:
* ifname -- name of interface
* hwaddr -- buffer for ehthernet address
*%RETURNS:
* Nothing
*%DESCRIPTION:
* Locates the Ethernet hardware address for an interface.
***********************************************************************/
void
getHWaddr(int sock, char const *ifname, unsigned char *hwaddr)
{
    char inbuf[8192];
    const struct sockaddr_dl *sdl;
    struct ifconf ifc;
    struct ifreq ifreq, *ifr;
    int i;
    int found = 0;

    ifc.ifc_len = sizeof(inbuf);
    ifc.ifc_buf = inbuf;
    if (ioctl(sock, SIOCGIFCONF, &ifc) < 0) {
	fatalSys("SIOCGIFCONF");
    }
    ifr = ifc.ifc_req;
    ifreq.ifr_name[0] = '\0';
    for (i = 0; i < ifc.ifc_len; ) {
	ifr = (struct ifreq *)((caddr_t)ifc.ifc_req + i);
	i += sizeof(ifr->ifr_name) +
		    (ifr->ifr_addr.sa_len > sizeof(struct sockaddr)
		    ? ifr->ifr_addr.sa_len
		    : sizeof(struct sockaddr));
	if (ifr->ifr_addr.sa_family == AF_LINK) {
	    sdl = (const struct sockaddr_dl *) &ifr->ifr_addr;
	    if ((sdl->sdl_type == IFT_ETHER) &&
	        (sdl->sdl_alen == ETH_ALEN) &&
		!strncmp(ifname, ifr->ifr_name, sizeof(ifr->ifr_name))) {
		if (found) {
		    char buffer[256];
		    sprintf(buffer, "interface %.16s has more than one ethernet address", ifname);
		    rp_fatal(buffer);
		} else {
		    found = 1;
	            memcpy(hwaddr, LLADDR(sdl), ETH_ALEN);
		}
	    }
	}
    }
    if (!found) {
	char buffer[256];
        sprintf(buffer, "interface %.16s has no ethernet address", ifname);
	rp_fatal(buffer);
    }
}

/**********************************************************************
*%FUNCTION: initFilter
*%ARGUMENTS:
* fd -- file descriptor of BSD device
* type -- Ethernet frame type (0 for watch mode)
* hwaddr -- buffer with ehthernet address
*%RETURNS:
* Nothing
*%DESCRIPTION:
* Initializes the packet filter rules.
***********************************************************************/
void
initFilter(int fd, UINT16_t type, unsigned char *hwaddr)
{
    /* Packet Filter Instructions:
     * Note that the ethernet type names come from "pppoe.h" and are
     * used here to maintain consistency with the rest of this file. */
    static struct bpf_insn bpfRun[] = {         /* run PPPoE */
        BPF_STMT(BPF_LD+BPF_H+BPF_ABS, 12),     /* ethernet type */
        BPF_JUMP(BPF_JMP+BPF_JEQ+BPF_K, ETH_PPPOE_SESSION, 5, 0),
        BPF_JUMP(BPF_JMP+BPF_JEQ+BPF_K, ETH_PPPOE_DISCOVERY, 0, 9),
        BPF_STMT(BPF_LD+BPF_W+BPF_ABS, 0),      /* first word of dest. addr */
#define PPPOE_BCAST_CMPW 4                     /* offset of word compare */
        BPF_JUMP(BPF_JMP+BPF_JEQ+BPF_K, 0, 0, 2),
        BPF_STMT(BPF_LD+BPF_H+BPF_ABS, 4),      /* next 1/2 word of dest. */
#define PPPOE_BCAST_CMPH 6                     /* offset of 1/2 word compare */
        BPF_JUMP(BPF_JMP+BPF_JEQ+BPF_K, 0, 4, 0),
        BPF_STMT(BPF_LD+BPF_W+BPF_ABS, 0),      /* first word of dest. addr */
#define PPPOE_FILTER_CMPW 8                     /* offset of word compare */
        BPF_JUMP(BPF_JMP+BPF_JEQ+BPF_K, 0, 0, 3),
        BPF_STMT(BPF_LD+BPF_H+BPF_ABS, 4),      /* next 1/2 word of dest. */
#define PPPOE_FILTER_CMPH 10                    /* offset of 1/rd compare */
        BPF_JUMP(BPF_JMP+BPF_JEQ+BPF_K, 0, 0, 1),
        BPF_STMT(BPF_RET+BPF_K, (u_int) -1),    /* keep packet */
        BPF_STMT(BPF_RET+BPF_K, 0),             /* drop packet */
    };

    /* Fix the potentially varying parts */
    bpfRun[1].code = (u_short) BPF_JMP+BPF_JEQ+BPF_K;
    bpfRun[1].jt   = 5;
    bpfRun[1].jf   = 0;
    bpfRun[1].k    = Eth_PPPOE_Session;

    bpfRun[2].code = (u_short) BPF_JMP+BPF_JEQ+BPF_K;
    bpfRun[2].jt   = 0;
    bpfRun[2].jf   = 9;
    bpfRun[2].k    = Eth_PPPOE_Discovery;

    {
      struct bpf_insn bpfInsn[sizeof(bpfRun) / sizeof(bpfRun[0])];
      struct bpf_program bpfProgram;
      memcpy(bpfInsn, bpfRun, sizeof(bpfRun));
      bpfInsn[PPPOE_BCAST_CMPW].k = ((0xff << 24) | (0xff << 16) |
                                     (0xff << 8) | 0xff);
      bpfInsn[PPPOE_BCAST_CMPH].k = ((0xff << 8) | 0xff);
      bpfInsn[PPPOE_FILTER_CMPW].k = ((hwaddr[0] << 24) | (hwaddr[1] << 16) |
				      (hwaddr[2] << 8) | hwaddr[3]);
      bpfInsn[PPPOE_FILTER_CMPH].k = ((hwaddr[4] << 8) | hwaddr[5]);
      bpfProgram.bf_len = (sizeof(bpfInsn) / sizeof(bpfInsn[0]));
      bpfProgram.bf_insns = &bpfInsn[0];
      
      /* Apply the filter */
      if (ioctl(fd, BIOCSETF, &bpfProgram) < 0) {
	fatalSys("ioctl(BIOCSETF)");
      }
    }
}

/**********************************************************************
*%FUNCTION: openInterface
*%ARGUMENTS:
* ifname -- name of interface
* type -- Ethernet frame type (0 for any frame type)
* hwaddr -- if non-NULL, set to the hardware address
*%RETURNS:
* A file descriptor for talking with the Ethernet card.  Exits on error.
* Note that the Linux version of this routine returns a socket instead.
*%DESCRIPTION:
* Opens a BPF on an interface for all PPPoE traffic (discovery and
* session).  If 'type' is 0, uses promiscuous mode to watch any PPPoE
* traffic on this network.
***********************************************************************/
int
openInterface(char const *ifname, UINT16_t type, unsigned char *hwaddr)
{
    static int fd = -1;
    char bpfName[32];
    u_int optval;
    struct bpf_version bpf_ver;
    struct ifreq ifr;
    int sock;
    int i;

    /* BSD only opens one socket for both Discovery and Session packets */
    if (fd >= 0) {
	return fd;
    }

    /* Find a free BPF device */
    for (i = 0; i < 256; i++) {
	sprintf(bpfName, "/dev/bpf%d", i);
	if (((fd = open(bpfName, O_RDWR, 0)) >= 0) ||
	    (errno != EBUSY)) {
	    break;
	}
    }
    if (fd < 0) {
	switch (errno) {
	case EACCES:		/* permission denied */
	    {
		char buffer[256];
		sprintf(buffer, "Cannot open %.32s -- pppoe must be run as root.", bpfName);
		rp_fatal(buffer);
	    }
	    break;
	case EBUSY:
	case ENOENT:		/* no such file */
	    if (i == 0) {
		rp_fatal("No /dev/bpf* devices (check your kernel configuration for BPF support)");
	    } else {
		rp_fatal("All /dev/bpf* devices are in use");
	    }
	    break;
	}
	fatalSys(bpfName);
    }

    if ((sock = socket(AF_LOCAL, SOCK_DGRAM, 0)) < 0) {
	fatalSys("socket");
    }

    /* Check that the interface is up */
    strncpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name));
    if (ioctl(sock, SIOCGIFFLAGS, &ifr) < 0) {
	fatalSys("ioctl(SIOCGIFFLAGS)");
    }
    if ((ifr.ifr_flags & IFF_UP) == 0) {
	char buffer[256];
	sprintf(buffer, "Interface %.16s is not up\n", ifname);
	rp_fatal(buffer);
    }

    /* Fill in hardware address and initialize the packet filter rules */
    if (hwaddr == NULL) {
	rp_fatal("openInterface: no hwaddr arg.");
    }
    getHWaddr(sock, ifname, hwaddr);
    initFilter(fd, type, hwaddr);

    /* Sanity check on MTU -- apparently does not work on OpenBSD */
#if !defined(__OpenBSD__)
    strncpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name));
    if (ioctl(sock, SIOCGIFMTU, &ifr) < 0) {
	fatalSys("ioctl(SIOCGIFMTU)");
    }
    if (ifr.ifr_mtu < ETH_DATA_LEN) {
	char buffer[256];
	sprintf(buffer, "Interface %.16s has MTU of %d -- should be %d.  You may have serious connection problems.",
		ifname, ifr.ifr_mtu, ETH_DATA_LEN);
	printErr(buffer);
    }
#endif

    /* done with the socket */
    if (close(sock) < 0) {
	fatalSys("close");
    }

    /* Check the BPF version number */
    if (ioctl(fd, BIOCVERSION, &bpf_ver) < 0) {
	fatalSys("ioctl(BIOCVERSION)");
    }
    if ((bpf_ver.bv_major != BPF_MAJOR_VERSION) ||
        (bpf_ver.bv_minor < BPF_MINOR_VERSION)) {
	char buffer[256];
	sprintf(buffer, "Unsupported BPF version: %d.%d (kernel: %d.%d)", 
			BPF_MAJOR_VERSION, BPF_MINOR_VERSION,
			bpf_ver.bv_major, bpf_ver.bv_minor);
	rp_fatal(buffer);
    }

    /* allocate a receive packet buffer */
    if (ioctl(fd, BIOCGBLEN, &bpfLength) < 0) {
	fatalSys("ioctl(BIOCGBLEN)");
    }
    if (!(bpfBuffer = (unsigned char *) malloc(bpfLength))) {
	rp_fatal("malloc");
    }

    /* reads should return as soon as there is a packet available */
    optval = 1;
    if (ioctl(fd, BIOCIMMEDIATE, &optval) < 0) {
	fatalSys("ioctl(BIOCIMMEDIATE)");
    }

    /* Bind the interface to the filter */
    strncpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name));
    if (ioctl(fd, BIOCSETIF, &ifr) < 0) {
	char buffer[256];
	sprintf(buffer, "ioctl(BIOCSETIF) can't select interface %.16s",
		ifname);
	rp_fatal(buffer);
    }

    syslog(LOG_INFO, "Interface=%.16s HWaddr=%02X:%02X:%02X:%02X:%02X:%02X Device=%.32s Buffer size=%d",
	   ifname, 
	   hwaddr[0], hwaddr[1], hwaddr[2],
	   hwaddr[3], hwaddr[4], hwaddr[5],
	   bpfName, bpfLength);
    return fd;
}

#endif /* USE_BPF */

#ifdef USE_LINUX_PACKET
/**********************************************************************
*%FUNCTION: openInterface
*%ARGUMENTS:
* ifname -- name of interface
* type -- Ethernet frame type
* hwaddr -- if non-NULL, set to the hardware address
*%RETURNS:
* A raw socket for talking to the Ethernet card.  Exits on error.
*%DESCRIPTION:
* Opens a raw Ethernet socket
***********************************************************************/
int
openInterface(char const *ifname, UINT16_t type, unsigned char *hwaddr)
{
    int optval=1;
    int fd;
    struct ifreq ifr;
    int domain, stype;

#ifdef HAVE_STRUCT_SOCKADDR_LL
    struct sockaddr_ll sa;
#else
    struct sockaddr sa;
#endif

    memset(&sa, 0, sizeof(sa));

#ifdef HAVE_STRUCT_SOCKADDR_LL
    domain = PF_PACKET;
    stype = SOCK_RAW;
#else
    domain = PF_INET;
    stype = SOCK_PACKET;
#endif

    if ((fd = socket(domain, stype, htons(type))) < 0) {
	/* Give a more helpful message for the common error case */
	if (errno == EPERM) {
	    rp_fatal("Cannot create raw socket -- pppoe must be run as root.");
	}
	fatalSys("socket");
    }

    if (setsockopt(fd, SOL_SOCKET, SO_BROADCAST, &optval, sizeof(optval)) < 0) {
	fatalSys("setsockopt");
    }

    /* Fill in hardware address */
    if (hwaddr) {
	strncpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name));
	if (ioctl(fd, SIOCGIFHWADDR, &ifr) < 0) {
	    fatalSys("ioctl(SIOCGIFHWADDR)");
	}
	memcpy(hwaddr, ifr.ifr_hwaddr.sa_data, ETH_ALEN);
#ifdef ARPHRD_ETHER
	if (ifr.ifr_hwaddr.sa_family != ARPHRD_ETHER) {
	    char buffer[256];
	    sprintf(buffer, "Interface %.16s is not Ethernet", ifname);
	    rp_fatal(buffer);
	}
#endif
	if (NOT_UNICAST(hwaddr)) {
	    char buffer[256];
	    sprintf(buffer,
		    "Interface %.16s has broadcast/multicast MAC address??",
		    ifname);
	    rp_fatal(buffer);
	}
    }

    /* Sanity check on MTU */
    strncpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name));
    if (ioctl(fd, SIOCGIFMTU, &ifr) < 0) {
	fatalSys("ioctl(SIOCGIFMTU)");
    }
    if (ifr.ifr_mtu < ETH_DATA_LEN) {
	char buffer[256];
	sprintf(buffer, "Interface %.16s has MTU of %d -- should be %d.  You may have serious connection problems.",
		ifname, ifr.ifr_mtu, ETH_DATA_LEN);
	printErr(buffer);
    }

#ifdef HAVE_STRUCT_SOCKADDR_LL
    /* Get interface index */
    sa.sll_family = AF_PACKET;
    sa.sll_protocol = htons(type);

    strncpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name));
    if (ioctl(fd, SIOCGIFINDEX, &ifr) < 0) {
	fatalSys("ioctl(SIOCFIGINDEX): Could not get interface index");
    }
    sa.sll_ifindex = ifr.ifr_ifindex;

#else
    strcpy(sa.sa_data, ifname);
#endif

    /* We're only interested in packets on specified interface */
    if (bind(fd, (struct sockaddr *) &sa, sizeof(sa)) < 0) {
	fatalSys("bind");
    }

    return fd;
}

#endif /* USE_LINUX */

/***********************************************************************
*%FUNCTION: sendPacket
*%ARGUMENTS:
* sock -- socket to send to
* pkt -- the packet to transmit
* size -- size of packet (in bytes)
*%RETURNS:
* 0 on success; -1 on failure
*%DESCRIPTION:
* Transmits a packet
***********************************************************************/
int
sendPacket(PPPoEConnection *conn, int sock, PPPoEPacket *pkt, int size)
{
#if defined(USE_BPF)
    if (write(sock, pkt, size) < 0) {
	sysErr("write (sendPacket)");
	return -1;
    }
#elif defined(HAVE_STRUCT_SOCKADDR_LL)
    if (send(sock, pkt, size, 0) < 0) {
	sysErr("send (sendPacket)");
	return -1;
    }
#else
#ifdef USE_DLPI

#define ABS(x)          ((x) < 0 ? -(x) : (x))

	u_char  addr[MAXDLADDR];
	u_char  phys[MAXDLADDR];
	u_char  sap[MAXDLADDR];
	u_char    xmitbuf[MAXDLBUF];
	int	data_size;

	short	tmp_sap;

	tmp_sap = htons(pkt->ethHdr.h_proto); 
	data_size = size - sizeof(struct ethhdr); 

	memcpy((char *)phys, (char *)pkt->ethHdr.h_dest, ETHERADDRL);
	memcpy((char *)sap,  (char *)&tmp_sap, sizeof(ushort_t));
	memcpy((char *)xmitbuf, (char *)pkt + sizeof(struct ethhdr), data_size); 

	if (dl_saplen > 0) {  /* order is sap+phys */
		(void) memcpy((char*)addr, (char*)&sap, dl_abssaplen);
		(void) memcpy((char*)addr+dl_abssaplen, (char*)phys, ETHERADDRL);
	} else {        /* order is phys+sap */
		(void) memcpy((char*)addr, (char*)phys, ETHERADDRL);
		(void) memcpy((char*)addr+ETHERADDRL, (char*)&sap, dl_abssaplen);
	}

#ifdef DL_DEBUG
	printf("%02x:%02x:%02x:%02x:%02x:%02x %02x:%02x\n", 
		addr[0],addr[1],addr[2],addr[3],addr[4],addr[5],
		addr[6],addr[7]);
#endif

	dlunitdatareq(sock, addr, dl_addrlen, 0, 0, xmitbuf, data_size);


#else
    struct sockaddr sa;

    if (!conn) {
	rp_fatal("relay and server not supported on Linux 2.0 kernels");
    }
    strcpy(sa.sa_data, conn->ifName);
    if (sendto(sock, pkt, size, 0, &sa, sizeof(sa)) < 0) {
	sysErr("sendto (sendPacket)");
	return -1;
    }
#endif
#endif
    return 0;
}

#ifdef USE_BPF
/***********************************************************************
*%FUNCTION: clearPacketHeader
*%ARGUMENTS:
* pkt -- packet that needs its head clearing
*%RETURNS:
* nothing
*%DESCRIPTION:
* Clears a PPPoE packet header after a truncated packet has been
* received.  Insures that the packet will fail any integrity tests
* and will be discarded by upper level routines.  Also resets the
* bpfSize and bpfOffset variables to force a new read on the next
* call to receivePacket().
***********************************************************************/
void
clearPacketHeader(PPPoEPacket *pkt)
{
    bpfSize = bpfOffset = 0;
    memset(pkt, 0, HDR_SIZE);
}
#endif

/***********************************************************************
*%FUNCTION: receivePacket
*%ARGUMENTS:
* sock -- socket to read from
* pkt -- place to store the received packet
* size -- set to size of packet in bytes
*%RETURNS:
* >= 0 if all OK; < 0 if error
*%DESCRIPTION:
* Receives a packet
***********************************************************************/
int
receivePacket(int sock, PPPoEPacket *pkt, int *size)
{
#ifdef USE_BPF
    struct bpf_hdr hdr;
    int seglen, copylen;

    if (bpfSize <= 0) {
	bpfOffset = 0;
	if ((bpfSize = read(sock, bpfBuffer, bpfLength)) < 0) {
	    sysErr("read (receivePacket)");
	    return -1;
	}
    }
    if (bpfSize < sizeof(hdr)) {
	syslog(LOG_ERR, "Truncated bpf packet header: len=%d", bpfSize);
	clearPacketHeader(pkt);		/* resets bpfSize and bpfOffset */
	return 0;
    }
    memcpy(&hdr, bpfBuffer + bpfOffset, sizeof(hdr));
    if (hdr.bh_caplen != hdr.bh_datalen) {
	syslog(LOG_ERR, "Truncated bpf packet: caplen=%d, datalen=%d",
	       hdr.bh_caplen, hdr.bh_datalen);
	clearPacketHeader(pkt);		/* resets bpfSize and bpfOffset */
	return 0;
    }
    seglen = hdr.bh_hdrlen + hdr.bh_caplen;
    if (seglen > bpfSize) {
	syslog(LOG_ERR, "Truncated bpf packet: seglen=%d, bpfSize=%d",
	       seglen, bpfSize);
	clearPacketHeader(pkt);		/* resets bpfSize and bpfOffset */
	return 0;
    }
    seglen = BPF_WORDALIGN(seglen);
    *size = copylen = ((hdr.bh_caplen < sizeof(PPPoEPacket)) ?
			hdr.bh_caplen : sizeof(PPPoEPacket));
    memcpy(pkt, bpfBuffer + bpfOffset + hdr.bh_hdrlen, copylen);
    if (seglen >= bpfSize) {
	bpfSize = bpfOffset = 0;
    } else {
	bpfSize -= seglen;
	bpfOffset += seglen;
    }
#else
#ifdef USE_DLPI
	struct strbuf data; 
	int flags = 0; 	
	int retval; 

	data.buf = (char *) pkt; 
	data.maxlen = MAXDLBUF; 
	data.len = 0; 
	
	if ((retval = getmsg(sock, NULL, &data, &flags)) < 0) {
	    sysErr("read (receivePacket)");
	    return -1;
	}

	*size = data.len; 

#else
    if ((*size = recv(sock, pkt, sizeof(PPPoEPacket), 0)) < 0) {
	sysErr("recv (receivePacket)");
	return -1;
    }
#endif
#endif
    return 0;
}

#ifdef USE_DLPI
/**********************************************************************
*%FUNCTION: openInterface
*%ARGUMENTS:
* ifname -- name of interface
* type -- Ethernet frame type
* hwaddr -- if non-NULL, set to the hardware address
*%RETURNS:
* A raw socket for talking to the Ethernet card.  Exits on error.
*%DESCRIPTION:
* Opens a raw Ethernet socket
***********************************************************************/
int
openInterface(char const *ifname, UINT16_t type, unsigned char *hwaddr)
{
    int fd;
    long buf[MAXDLBUF]; 

	union   DL_primitives   *dlp;

    char base_dev[PATH_MAX]; 
    int ppa; 

    if(strlen(ifname) > PATH_MAX) {
	rp_fatal("socket: string to long"); 
    }

    ppa = atoi(&ifname[strlen(ifname)-1]);
    strncpy(base_dev, ifname, PATH_MAX); 
    base_dev[strlen(base_dev)-1] = '\0'; 

/* rearranged order of DLPI code - delphys 20010803 */
    dlp = (union DL_primitives*) buf;

    if (( fd = open(base_dev, O_RDWR)) < 0) {
	/* Give a more helpful message for the common error case */
	if (errno == EPERM) {
	    rp_fatal("Cannot create raw socket -- pppoe must be run as root.");
	}
	fatalSys("socket");
    }

/* rearranged order of DLPI code - delphys 20010803 */
    dlattachreq(fd, ppa); 
    dlokack(fd, (char *)buf);

    dlbindreq(fd, type, 0, DL_CLDLS, 0, 0);
    dlbindack(fd, (char *)buf);

    dlinforeq(fd);
    dlinfoack(fd, (char *)buf);

    dl_abssaplen = ABS(dlp->info_ack.dl_sap_length);
    dl_saplen = dlp->info_ack.dl_sap_length;
    if (ETHERADDRL != (dlp->info_ack.dl_addr_length - dl_abssaplen))
	fatalSys("invalid destination physical address length");
    dl_addrlen = dl_abssaplen + ETHERADDRL;

/* ethernet address retrieved as part of DL_INFO_ACK - delphys 20010803 */
    memcpy(hwaddr, (u_char*)((char*)(dlp) + (int)(dlp->info_ack.dl_addr_offset)), ETHERADDRL);

    if ( strioctl(fd, DLIOCRAW, -1, 0, NULL) < 0 ) { 
	fatalSys("DLIOCRAW"); 
    }

    if (ioctl(fd, I_FLUSH, FLUSHR) < 0) fatalSys("I_FLUSH");

    return fd;
}

/* cloned from dlcommon.c */

void dlpromisconreq(int fd, u_long level)
{
        dl_promiscon_req_t      promiscon_req;
        struct  strbuf  ctl;
        int     flags;

        promiscon_req.dl_primitive = DL_PROMISCON_REQ;
        promiscon_req.dl_level = level;

        ctl.maxlen = 0;
        ctl.len = sizeof (promiscon_req);
        ctl.buf = (char *) &promiscon_req;

        flags = 0;

        if (putmsg(fd, &ctl, (struct strbuf*) NULL, flags) < 0)
                fatalSys("dlpromiscon:  putmsg");

}

void dlinforeq(int fd)
{
        dl_info_req_t   info_req;
        struct  strbuf  ctl;
        int     flags;

        info_req.dl_primitive = DL_INFO_REQ;

        ctl.maxlen = 0;
        ctl.len = sizeof (info_req);
        ctl.buf = (char *) &info_req;

        flags = RS_HIPRI;

        if (putmsg(fd, &ctl, (struct strbuf*) NULL, flags) < 0)
                fatalSys("dlinforeq:  putmsg");
}

void dlunitdatareq(int fd, u_char *addrp, int addrlen, u_long minpri, u_long maxpri, u_char *datap, int datalen)
{
        long    buf[MAXDLBUF];
        union   DL_primitives   *dlp;
        struct  strbuf  data, ctl;

        dlp = (union DL_primitives*) buf;

        dlp->unitdata_req.dl_primitive = DL_UNITDATA_REQ;
        dlp->unitdata_req.dl_dest_addr_length = addrlen;
        dlp->unitdata_req.dl_dest_addr_offset = sizeof (dl_unitdata_req_t);
        dlp->unitdata_req.dl_priority.dl_min = minpri;
        dlp->unitdata_req.dl_priority.dl_max = maxpri;

        (void) memcpy(OFFADDR(dlp, sizeof (dl_unitdata_req_t)), addrp, addrlen);

        ctl.maxlen = 0;
        ctl.len = sizeof (dl_unitdata_req_t) + addrlen;
        ctl.buf = (char *) buf;

        data.maxlen = 0;
        data.len = datalen;
        data.buf = (char *) datap;

        if (putmsg(fd, &ctl, &data, 0) < 0)
                fatalSys("dlunitdatareq:  putmsg");
}

void dlinfoack(int fd, char *bufp)
{
        union   DL_primitives   *dlp;
        struct  strbuf  ctl;
        int     flags;

        ctl.maxlen = MAXDLBUF;
        ctl.len = 0;
        ctl.buf = bufp;

        strgetmsg(fd, &ctl, (struct strbuf*)NULL, &flags, "dlinfoack");

        dlp = (union DL_primitives *) ctl.buf;

        expecting(DL_INFO_ACK, dlp);

        if (ctl.len < sizeof (dl_info_ack_t)) {
		char buffer[256];
		sprintf(buffer, "dlinfoack:  response ctl.len too short:  %d", ctl.len); 
                rp_fatal(buffer); 
	}

        if (flags != RS_HIPRI)
                rp_fatal("dlinfoack:  DL_INFO_ACK was not M_PCPROTO");

        if (ctl.len < sizeof (dl_info_ack_t)) {
		char buffer[256];
		sprintf(buffer, "dlinfoack:  short response ctl.len:  %d", ctl.len); 
		rp_fatal(buffer); 
	}
}

void dlbindreq(int fd, u_long sap, u_long max_conind, u_long service_mode, u_long conn_mgmt, u_long xidtest)
{
        dl_bind_req_t   bind_req;
        struct  strbuf  ctl;
        int     flags;

        bind_req.dl_primitive = DL_BIND_REQ;
        bind_req.dl_sap = sap;
        bind_req.dl_max_conind = max_conind;
        bind_req.dl_service_mode = service_mode;
        bind_req.dl_conn_mgmt = conn_mgmt;
        bind_req.dl_xidtest_flg = xidtest;

        ctl.maxlen = 0;
        ctl.len = sizeof (bind_req);
        ctl.buf = (char *) &bind_req;

        flags = 0;

        if (putmsg(fd, &ctl, (struct strbuf*) NULL, flags) < 0)
                fatalSys("dlbindreq:  putmsg");
}

void dlattachreq(int fd, u_long ppa)
{
        dl_attach_req_t attach_req;
        struct  strbuf  ctl;
        int     flags;

        attach_req.dl_primitive = DL_ATTACH_REQ;
        attach_req.dl_ppa = ppa;

        ctl.maxlen = 0;
        ctl.len = sizeof (attach_req);
        ctl.buf = (char *) &attach_req;

        flags = 0;

        if (putmsg(fd, &ctl, (struct strbuf*) NULL, flags) < 0)
                fatalSys("dlattachreq:  putmsg");
}

void dlokack(int fd, char *bufp)
{
        union   DL_primitives   *dlp;
        struct  strbuf  ctl;
        int     flags;

        ctl.maxlen = MAXDLBUF;
        ctl.len = 0;
        ctl.buf = bufp;

        strgetmsg(fd, &ctl, (struct strbuf*)NULL, &flags, "dlokack");

        dlp = (union DL_primitives *) ctl.buf;

        expecting(DL_OK_ACK, dlp);

        if (ctl.len < sizeof (dl_ok_ack_t)) { 
		char buffer[256];
		sprintf(buffer, "dlokack:  response ctl.len too short:  %d", ctl.len);
		rp_fatal(buffer); 
	}

        if (flags != RS_HIPRI)
                rp_fatal("dlokack:  DL_OK_ACK was not M_PCPROTO");

        if (ctl.len < sizeof (dl_ok_ack_t)) {
		char buffer[256]; 
		sprintf(buffer, "dlokack:  short response ctl.len:  %d", ctl.len);
		rp_fatal(buffer); 
	}
}

void dlbindack(int fd, char *bufp)
{
        union   DL_primitives   *dlp;
        struct  strbuf  ctl;
        int     flags;

        ctl.maxlen = MAXDLBUF;
        ctl.len = 0;
        ctl.buf = bufp;

        strgetmsg(fd, &ctl, (struct strbuf*)NULL, &flags, "dlbindack");

        dlp = (union DL_primitives *) ctl.buf;

        expecting(DL_BIND_ACK, dlp);

        if (flags != RS_HIPRI)
                rp_fatal("dlbindack:  DL_OK_ACK was not M_PCPROTO");

        if (ctl.len < sizeof (dl_bind_ack_t)) {
		char buffer[256];
		sprintf(buffer, "dlbindack:  short response ctl.len:  %d", ctl.len);
		rp_fatal(buffer); 
	}
}

int strioctl(int fd, int cmd, int timout, int len, char *dp)
{
        struct  strioctl        sioc;
        int     rc;

        sioc.ic_cmd = cmd;
        sioc.ic_timout = timout;
        sioc.ic_len = len;
        sioc.ic_dp = dp;
        rc = ioctl(fd, I_STR, &sioc);

        if (rc < 0)
                return (rc);
        else
                return (sioc.ic_len);
}

void strgetmsg(int fd, struct strbuf *ctlp, struct strbuf *datap, int *flagsp, char *caller)
{
        int     rc;
        static  char    errmsg[80];

        /*
         * Start timer.
         */
        (void) signal(SIGALRM, sigalrm);
        if (alarm(MAXWAIT) < 0) {
                (void) sprintf(errmsg, "%s:  alarm", caller);
                fatalSys(errmsg);
        }

        /*
         * Set flags argument and issue getmsg().
         */
        *flagsp = 0;
        if ((rc = getmsg(fd, ctlp, datap, flagsp)) < 0) {
                (void) sprintf(errmsg, "%s:  getmsg", caller);
                fatalSys(errmsg);
        }

        /*
         * Stop timer.
         */
        if (alarm(0) < 0) {
                (void) sprintf(errmsg, "%s:  alarm", caller);
                fatalSys(errmsg);
        }

        /*
         * Check for MOREDATA and/or MORECTL.
         */
        if ((rc & (MORECTL | MOREDATA)) == (MORECTL | MOREDATA)) {
		char buffer[256]; 
		sprintf(buffer, "%s:  MORECTL|MOREDATA", caller);
		rp_fatal(buffer);
	}
                
        if (rc & MORECTL) {
		char buffer[256];
		sprintf(buffer, "%s:  MORECTL", caller);
		rp_fatal(buffer); 
	}
        
        if (rc & MOREDATA) {
		char buffer[256]; 
		sprintf(buffer, "%s:  MOREDATA", caller);
		rp_fatal(buffer);
	}

        /*
         * Check for at least sizeof (long) control data portion.
         */
        if (ctlp->len < sizeof (long)) {
		char buffer[256]; 
		sprintf(buffer, "getmsg:  control portion length < sizeof (long):  %d", ctlp->len);
		rp_fatal(buffer); 
	}
}

void sigalrm(int sig)
{
        (void) rp_fatal("sigalrm:  TIMEOUT");
}

void expecting(int prim, union DL_primitives *dlp)
{
        if (dlp->dl_primitive != (u_long)prim) {
		char buffer[256]; 
		sprintf(buffer, "expected %s got %s", dlprim(prim), dlprim(dlp->dl_primitive));
		rp_fatal(buffer); 
		exit(1); 
	}
}

char *dlprim(u_long prim)
{
        static  char    primbuf[80];

        switch ((int)prim) {
                CASERET(DL_INFO_REQ);
                CASERET(DL_INFO_ACK);
                CASERET(DL_ATTACH_REQ);
                CASERET(DL_DETACH_REQ);
                CASERET(DL_BIND_REQ);
                CASERET(DL_BIND_ACK);
                CASERET(DL_UNBIND_REQ);
                CASERET(DL_OK_ACK);
                CASERET(DL_ERROR_ACK);
                CASERET(DL_SUBS_BIND_REQ);
                CASERET(DL_SUBS_BIND_ACK);
                CASERET(DL_UNITDATA_REQ);
                CASERET(DL_UNITDATA_IND);
                CASERET(DL_UDERROR_IND);
                CASERET(DL_UDQOS_REQ);
                CASERET(DL_CONNECT_REQ);
                CASERET(DL_CONNECT_IND);
                CASERET(DL_CONNECT_RES);
                CASERET(DL_CONNECT_CON);
                CASERET(DL_TOKEN_REQ);
                CASERET(DL_TOKEN_ACK);
                CASERET(DL_DISCONNECT_REQ);
                CASERET(DL_DISCONNECT_IND);
                CASERET(DL_RESET_REQ);
                CASERET(DL_RESET_IND);
                CASERET(DL_RESET_RES);
                CASERET(DL_RESET_CON);
                default:
                        (void) sprintf(primbuf, "unknown primitive 0x%lx", prim);
                        return (primbuf);
        }
}

#endif /* USE_DLPI */