dlpi.c

DHCP服务器源码

/* dlpi.c
 
   Data Link Provider Interface (DLPI) network interface code. */

/*
 * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
 * Copyright (c) 1996-2003 by Internet Software Consortium
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
 * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 *
 *   Internet Systems Consortium, Inc.
 *   950 Charter Street
 *   Redwood City, CA 94063
 *   <[e-mail]>
 *   http://www.isc.org/
 *
 * This software was written for Internet Systems Consortium
 * by Eric James Negaard, <[e-mail]>.  To learn more about
 * Internet Systems Consortium, see ``http://www.isc.org''.
 *
 * Joost Mulders has also done considerable work in debugging the DLPI API
 * support on Solaris and getting this code to work properly on a variety
 * of different Solaris platforms.
 */

/*
 * Based largely in part to the existing NIT code in nit.c.
 *
 * This code has been developed and tested on sparc-based machines running
 * SunOS 5.5.1, with le and hme network interfaces.  It should be pretty
 * generic, though.
 */

/*
 * Implementation notes:
 *
 * I first tried to write this code to the "vanilla" DLPI 2.0 API.
 * It worked on a Sun Ultra-1 with a hme interface, but didn't work
 * on Sun SparcStation 5's with "le" interfaces (the packets sent out
 * via dlpiunitdatareq contained an Ethernet type of 0x0000 instead
 * of the expected 0x0800).
 *
 * Therefore I added the "DLPI_RAW" code which is a Sun extension to
 * the DLPI standard.  This code works on both of the above machines.
 * This is configurable in the OS-dependent include file by defining
 * USE_DLPI_RAW.
 *
 * It quickly became apparant that I should also use the "pfmod"
 * STREAMS module to cut down on the amount of user level packet
 * processing.  I don't know how widely available "pfmod" is, so it's
 * use is conditionally included. This is configurable in the
 * OS-dependent include file by defining USE_DLPI_PFMOD.
 *
 * A major quirk on the Sun's at least, is that no packets seem to get
 * sent out the interface until six seconds after the interface is
 * first "attached" to [per system reboot] (it's actually from when
 * the interface is attached, not when it is plumbed, so putting a
 * sleep into the dhclient-script at PREINIT time doesn't help).  I
 * HAVE tried, without success to poll the fd to see when it is ready
 * for writing.  This doesn't help at all. If the sleeps are not done,
 * the initial DHCPREQUEST or DHCPDISCOVER never gets sent out, so
 * I've put them here, when register_send and register_receive are
 * called (split up into two three-second sleeps between the notices,
 * so that it doesn't seem like so long when you're watching :-).  The
 * amount of time to sleep is configurable in the OS-dependent include
 * file by defining DLPI_FIRST_SEND_WAIT to be the number of seconds
 * to sleep.
 */

#ifndef lint
static char copyright[] =
"$Id: dlpi.c,v 1.28.2.2 2004/06/10 17:59:17 dhankins Exp $ Copyright (c) 2004 Internet Systems Consortium.  All rights reserved.\n";
#endif /* not lint */

#include "dhcpd.h"

#if defined (USE_DLPI_SEND) || defined (USE_DLPI_RECEIVE)

# include <sys/ioctl.h>
# include <sys/time.h>
# include <sys/dlpi.h>
# include <stropts.h>
# ifdef USE_DLPI_PFMOD
#  include <sys/pfmod.h>
# endif
# ifdef USE_POLL
#  include <poll.h>
# endif

# include <netinet/in_systm.h>
# include "includes/netinet/ip.h"
# include "includes/netinet/udp.h"
# include "includes/netinet/if_ether.h"

# ifdef USE_DLPI_PFMOD
#  ifdef USE_DLPI_RAW
#   define DLPI_MODNAME "DLPI+RAW+PFMOD"
#  else
#   define DLPI_MODNAME "DLPI+PFMOD"
#  endif
# else
#  ifdef USE_DLPI_RAW
#   define DLPI_MODNAME "DLPI+RAW"
#  else
#   define DLPI_MODNAME "DLPI"
#  endif
# endif

# ifndef ABS
#  define ABS(x) ((x) >= 0 ? (x) : 0-(x))
# endif

static int strioctl PROTO ((int fd, int cmd, int timeout, int len, char *dp));

#define DLPI_MAXDLBUF		8192	/* Buffer size */
#define DLPI_MAXDLADDR		1024	/* Max address size */
#define DLPI_DEVDIR		"/dev/"	/* Device directory */

static int dlpiopen PROTO ((char *ifname));
static int dlpiunit PROTO ((char *ifname));
static int dlpiinforeq PROTO ((int fd));
static int dlpiphysaddrreq PROTO ((int fd, unsigned long addrtype));
static int dlpiattachreq PROTO ((int fd, unsigned long ppa));
static int dlpibindreq PROTO ((int fd, unsigned long sap, unsigned long max_conind,
			       unsigned long service_mode, unsigned long conn_mgmt,
			       unsigned long xidtest));
static int dlpidetachreq PROTO ((int fd));
static int dlpiunbindreq PROTO ((int fd));
static int dlpiokack PROTO ((int fd, char *bufp));
static int dlpiinfoack PROTO ((int fd, char *bufp));
static int dlpiphysaddrack PROTO ((int fd, char *bufp));
static int dlpibindack PROTO ((int fd, char *bufp));
static int dlpiunitdatareq PROTO ((int fd, unsigned char *addr,
				   int addrlen, unsigned long minpri,
				   unsigned long maxpri, unsigned char *data,
				   int datalen));
static int dlpiunitdataind PROTO ((int fd,
				   unsigned char *dstaddr,
				   unsigned long *dstaddrlen,
				   unsigned char *srcaddr,
				   unsigned long *srcaddrlen,
				   unsigned long *grpaddr,
				   unsigned char *data,
				   int datalen));

# ifndef USE_POLL
static void	sigalrm PROTO ((int sig));
# endif
static int	expected PROTO ((unsigned long prim, union DL_primitives *dlp,
				  int msgflags));
static int	strgetmsg PROTO ((int fd, struct strbuf *ctlp,
				  struct strbuf *datap, int *flagsp,
				  char *caller));

/* Reinitializes the specified interface after an address change.   This
   is not required for packet-filter APIs. */

#ifdef USE_DLPI_SEND
void if_reinitialize_send (info)
	struct interface_info *info;
{
}
#endif

#ifdef USE_DLPI_RECEIVE
void if_reinitialize_receive (info)
	struct interface_info *info;
{
}
#endif

/* Called by get_interface_list for each interface that's discovered.
   Opens a packet filter for each interface and adds it to the select
   mask. */

int if_register_dlpi (info)
	struct interface_info *info;
{
	int sock;
	int unit;
	long buf [DLPI_MAXDLBUF];
	union DL_primitives *dlp;

	dlp = (union DL_primitives *)buf;

	/* Open a DLPI device */
	if ((sock = dlpiopen (info -> name)) < 0) {
	    log_fatal ("Can't open DLPI device for %s: %m", info -> name);
	}


	/*
       * Submit a DL_INFO_REQ request, to find the dl_mac_type and 
         * dl_provider_style
	 */
	if (dlpiinforeq(sock) < 0 || dlpiinfoack(sock, (char *)buf) < 0) {
	    log_fatal ("Can't get DLPI MAC type for %s: %m", info -> name);
	} else {
	    switch (dlp -> info_ack.dl_mac_type) {
	      case DL_CSMACD: /* IEEE 802.3 */
	      case DL_ETHER:
		info -> hw_address.hbuf [0] = HTYPE_ETHER;
		break;
	      /* adding token ring 5/1999 - [e-mail]  */ 
	      case DL_TPR:
		info -> hw_address.hbuf [0] = HTYPE_IEEE802;
		break;
	      case DL_FDDI:
		info -> hw_address.hbuf [0] = HTYPE_FDDI;
		break;
	      default:
              log_fatal ("%s: unsupported DLPI MAC type %ld",
                     info -> name, dlp -> info_ack.dl_mac_type);
		break;
	    }
            /*
             * copy the sap length and broadcast address of this interface
             * to interface_info. This fixes nothing but seemed nicer than to
             * assume -2 and ffffff.
             */
            info -> dlpi_sap_length = dlp -> info_ack.dl_sap_length;
            info -> dlpi_broadcast_addr.hlen = 
             dlp -> info_ack.dl_brdcst_addr_length;
            memcpy (info -> dlpi_broadcast_addr.hbuf, 
             (char *)dlp + dlp -> info_ack.dl_brdcst_addr_offset, 
             dlp -> info_ack.dl_brdcst_addr_length);
	}

	if (dlp -> info_ack.dl_provider_style == DL_STYLE2) {
	    /*
	     * Attach to the device.  If this fails, the device
	     * does not exist.
	     */
	    unit = dlpiunit (info -> name);
	
	    if (dlpiattachreq (sock, unit) < 0
		|| dlpiokack (sock, (char *)buf) < 0) {
		log_fatal ("Can't attach DLPI device for %s: %m", info -> name);
	    }
	}

	/*
	 * Bind to the IP service access point (SAP), connectionless (CLDLS).
	 */
      if (dlpibindreq (sock, ETHERTYPE_IP, 0, DL_CLDLS, 0, 0) < 0
	    || dlpibindack (sock, (char *)buf) < 0) {
	    log_fatal ("Can't bind DLPI device for %s: %m", info -> name);
	}

	/*
	 * Submit a DL_PHYS_ADDR_REQ request, to find
	 * the hardware address
	 */
	if (dlpiphysaddrreq (sock, DL_CURR_PHYS_ADDR) < 0
	    || dlpiphysaddrack (sock, (char *)buf) < 0) {
	    log_fatal ("Can't get DLPI hardware address for %s: %m",
		   info -> name);
	}

	info -> hw_address.hlen = dlp -> physaddr_ack.dl_addr_length + 1;
	memcpy (&info -> hw_address.hbuf [1],
		(char *)buf + dlp -> physaddr_ack.dl_addr_offset,
		dlp -> physaddr_ack.dl_addr_length);

#ifdef USE_DLPI_RAW
	if (strioctl (sock, DLIOCRAW, INFTIM, 0, 0) < 0) {
	    log_fatal ("Can't set DLPI RAW mode for %s: %m",
		   info -> name);
	}
#endif

#ifdef USE_DLPI_PFMOD
	if (ioctl (sock, I_PUSH, "pfmod") < 0) {
	    log_fatal ("Can't push packet filter onto DLPI for %s: %m",
		   info -> name);
	}
#endif

	return sock;
}

static int
strioctl (fd, cmd, timeout, len, dp)
int fd;
int cmd;
int timeout;
int len;
char *dp;
{
    struct strioctl sio;
    int rslt;

    sio.ic_cmd = cmd;
    sio.ic_timout = timeout;
    sio.ic_len = len;
    sio.ic_dp = dp;

    if ((rslt = ioctl (fd, I_STR, &sio)) < 0) {
	return rslt;
    } else {
	return sio.ic_len;
    }
}

#ifdef USE_DLPI_SEND
void if_register_send (info)
	struct interface_info *info;
{
	/* If we're using the DLPI API for sending and receiving,
	   we don't need to register this interface twice. */
#ifndef USE_DLPI_RECEIVE
# ifdef USE_DLPI_PFMOD
	struct packetfilt pf;
# endif

	info -> wfdesc = if_register_dlpi (info);

# ifdef USE_DLPI_PFMOD
	/* Set up an PFMOD filter that rejects everything... */
	pf.Pf_Priority = 0;
	pf.Pf_FilterLen = 1;
	pf.Pf_Filter [0] = ENF_PUSHZERO;

	/* Install the filter */
	if (strioctl (info -> wfdesc, PFIOCSETF, INFTIM,
		      sizeof (pf), (char *)&pf) < 0) {
	    log_fatal ("Can't set PFMOD send filter on %s: %m", info -> name);
	}

# endif /* USE_DLPI_PFMOD */
#else /* !defined (USE_DLPI_RECEIVE) */
	/*
	 * If using DLPI for both send and receive, simply re-use
	 * the read file descriptor that was set up earlier.
	 */
	info -> wfdesc = info -> rfdesc;
#endif

        if (!quiet_interface_discovery)
		log_info ("Sending on   DLPI/%s/%s%s%s",
		      info -> name,
		      print_hw_addr (info -> hw_address.hbuf [0],
				     info -> hw_address.hlen - 1,
				     &info -> hw_address.hbuf [1]),
		      (info -> shared_network ? "/" : ""),
		      (info -> shared_network ?
		       info -> shared_network -> name : ""));

#ifdef DLPI_FIRST_SEND_WAIT
/* See the implementation notes at the beginning of this file */
# ifdef USE_DLPI_RECEIVE
	sleep (DLPI_FIRST_SEND_WAIT - (DLPI_FIRST_SEND_WAIT / 2));
# else
	sleep (DLPI_FIRST_SEND_WAIT);
# endif
#endif
}

void if_deregister_send (info)
	struct interface_info *info;
{
	/* If we're using the DLPI API for sending and receiving,
	   we don't need to register this interface twice. */
#ifndef USE_DLPI_RECEIVE
	close (info -> wfdesc);
#endif
	info -> wfdesc = -1;

        if (!quiet_interface_discovery)
		log_info ("Disabling output on DLPI/%s/%s%s%s",
		      info -> name,
		      print_hw_addr (info -> hw_address.hbuf [0],
				     info -> hw_address.hlen - 1,
				     &info -> hw_address.hbuf [1]),
		      (info -> shared_network ? "/" : ""),
		      (info -> shared_network ?
		       info -> shared_network -> name : ""));
}
#endif /* USE_DLPI_SEND */

#ifdef USE_DLPI_RECEIVE
/* Packet filter program...
   XXX Changes to the filter program may require changes to the constant
   offsets used in if_register_send to patch the NIT program! XXX */

void if_register_receive (info)
	struct interface_info *info;
{
#ifdef USE_DLPI_PFMOD
	struct packetfilt pf;
        struct ip iphdr;
        u_int16_t offset;
#endif

	/* Open a DLPI device and hang it on this interface... */
	info -> rfdesc = if_register_dlpi (info);

#ifdef USE_DLPI_PFMOD
	/* Set up the PFMOD filter program. */
	/* XXX Unlike the BPF filter program, this one won't work if the
	   XXX IP packet is fragmented or if there are options on the IP
	   XXX header. */
	pf.Pf_Priority = 0;
	pf.Pf_FilterLen = 0;

#if defined (USE_DLPI_RAW)
# define ETHER_H_PREFIX (14) /* sizeof (ethernet_header) */
    /*
     * ethertype == ETHERTYPE_IP
     */
    offset = 12;
    pf.Pf_Filter [pf.Pf_FilterLen++] = ENF_PUSHWORD + (offset / 2);
    pf.Pf_Filter [pf.Pf_FilterLen++] = ENF_PUSHLIT | ENF_CAND;
    pf.Pf_Filter [pf.Pf_FilterLen++] = htons (ETHERTYPE_IP);
# else
# define ETHER_H_PREFIX (0)
# endif /* USE_DLPI_RAW */
	/*
	 * The packets that will be received on this file descriptor
	 * will be IP packets (due to the SAP that was specified in
	 * the dlbind call).  There will be no ethernet header.
	 * Therefore, setup the packet filter to check the protocol
	 * field for UDP, and the destination port number equal
	 * to the local port.  All offsets are relative to the start
	 * of an IP packet.
	 */

        /*
         * BOOTPS destination port
         */
        offset = ETHER_H_PREFIX + sizeof (iphdr) + sizeof (u_int16_t);
        pf.Pf_Filter [pf.Pf_FilterLen++] = ENF_PUSHWORD + (offset / 2);
        pf.Pf_Filter [pf.Pf_FilterLen++] = ENF_PUSHLIT | ENF_CAND;
        pf.Pf_Filter [pf.Pf_FilterLen++] = local_port;

        /*