dlpi.c

DHCP服务器源码

         * protocol should be udp. this is a byte compare, test for
         * endianess.
         */
        offset = ETHER_H_PREFIX + ((u_int8_t *)&(iphdr.ip_p) - (u_int8_t *)&iphdr);
        pf.Pf_Filter [pf.Pf_FilterLen++] = ENF_PUSHWORD + (offset / 2);
        pf.Pf_Filter [pf.Pf_FilterLen++] = ENF_PUSHLIT | ENF_AND;
        pf.Pf_Filter [pf.Pf_FilterLen++] = htons (0x00FF);
        pf.Pf_Filter [pf.Pf_FilterLen++] = ENF_PUSHLIT | ENF_CAND;
      pf.Pf_Filter [pf.Pf_FilterLen++] = htons (IPPROTO_UDP);

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

        if (!quiet_interface_discovery)
		log_info ("Listening 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_SEND
	sleep (DLPI_FIRST_SEND_WAIT / 2);
# else
	sleep (DLPI_FIRST_SEND_WAIT);
# endif
#endif
}

void if_deregister_receive (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_SEND
	close (info -> rfdesc);
#endif
	info -> rfdesc = -1;

        if (!quiet_interface_discovery)
		log_info ("Disabling input 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_RECEIVE */

#ifdef USE_DLPI_SEND
ssize_t send_packet (interface, packet, raw, len, from, to, hto)
	struct interface_info *interface;
	struct packet *packet;
	struct dhcp_packet *raw;
	size_t len;
	struct in_addr from;
	struct sockaddr_in *to;
	struct hardware *hto;
{
	unsigned hbufp = 0;
	double hh [32];
	double ih [1536 / sizeof (double)];
	unsigned char *dbuf = (unsigned char *)ih;
	unsigned dbuflen;
	unsigned char dstaddr [DLPI_MAXDLADDR];
	unsigned addrlen;
	int result;
	int fudge;

	if (!strcmp (interface -> name, "fallback"))
		return send_fallback (interface, packet, raw,
				      len, from, to, hto);

	dbuflen = 0;

	/* Assemble the headers... */
#ifdef USE_DLPI_RAW
	assemble_hw_header (interface, (unsigned char *)hh, &dbuflen, hto);
      if (dbuflen > sizeof hh)
              log_fatal ("send_packet: hh buffer too small.\n");
	fudge = dbuflen % 4; /* IP header must be word-aligned. */
	memcpy (dbuf + fudge, (unsigned char *)hh, dbuflen);
	dbuflen += fudge;
#else
	fudge = 0;
#endif
	assemble_udp_ip_header (interface, dbuf, &dbuflen, from.s_addr,
				to -> sin_addr.s_addr, to -> sin_port,
				(unsigned char *)raw, len);

	/* Copy the data into the buffer (yuk). */
	memcpy (dbuf + dbuflen, raw, len);
	dbuflen += len;

#ifdef USE_DLPI_RAW
	result = write (interface -> wfdesc, dbuf + fudge, dbuflen - fudge);
#else

	/*
         * Setup the destination address (DLSAP) in dstaddr 
         *
         * If sap_length < 0 we must deliver the DLSAP as phys+sap. 
         * If sap_length > 0 we must deliver the DLSAP as sap+phys.
         *
         * sap = Service Access Point == ETHERTYPE_IP
         * sap + datalink address is called DLSAP in dlpi speak.
         */
        { /* ENCODE DLSAP */
          unsigned char phys [DLPI_MAXDLADDR];
          unsigned char sap [4];
          int sap_len = interface -> dlpi_sap_length;
          int phys_len = interface -> hw_address.hlen - 1;

          /* sap = htons (ETHERTYPE_IP) kludge */
          memset (sap, 0, sizeof (sap));
# if (BYTE_ORDER == LITTLE_ENDIAN)
          sap [0] = 0x00;
          sap [1] = 0x08;
# else
          sap [0] = 0x08;
          sap [1] = 0x00;
# endif

        if (hto && hto -> hlen == interface -> hw_address.hlen)
             memcpy ( phys, (char *) &hto -> hbuf [1], phys_len);
          else 
             memcpy ( phys, interface -> dlpi_broadcast_addr.hbuf, 
              interface -> dlpi_broadcast_addr.hlen);
           
          if (sap_len < 0) { 
             memcpy ( dstaddr, phys, phys_len);
             memcpy ( (char *) &dstaddr [phys_len], sap, ABS (sap_len));
          }
          else {
             memcpy ( dstaddr, (void *) sap, sap_len);
             memcpy ( (char *) &dstaddr [sap_len], phys, phys_len);
          }
        addrlen = phys_len + ABS (sap_len);
      } /* ENCODE DLSAP */

	result = dlpiunitdatareq (interface -> wfdesc, dstaddr, addrlen,
				  0, 0, dbuf, dbuflen);
#endif /* USE_DLPI_RAW */
	if (result < 0)
		log_error ("send_packet: %m");
	return result;
}
#endif /* USE_DLPI_SEND */

#ifdef USE_DLPI_RECEIVE
ssize_t receive_packet (interface, buf, len, from, hfrom)
	struct interface_info *interface;
	unsigned char *buf;
	size_t len;
	struct sockaddr_in *from;
	struct hardware *hfrom;
{
	unsigned char dbuf [1536];
	unsigned char srcaddr [DLPI_MAXDLADDR];
	unsigned long srcaddrlen;
	int flags = 0;
	int length = 0;
	int offset = 0;
	int rslt;
	int bufix = 0;
	
#ifdef USE_DLPI_RAW
	length = read (interface -> rfdesc, dbuf, sizeof (dbuf));
#else	
	length = dlpiunitdataind (interface -> rfdesc, (unsigned char *)NULL,
				  (unsigned long *)NULL, srcaddr, &srcaddrlen,
				  (unsigned long *)NULL, dbuf, sizeof (dbuf));
#endif

	if (length <= 0) {
	    return length;
	}

# if !defined (USE_DLPI_RAW)
        /*
         * Copy the sender's hw address into hfrom
         * If sap_len < 0 the DLSAP is as phys+sap.
         * If sap_len > 0 the DLSAP is as sap+phys.
         *
         * sap is discarded here.
         */
        { /* DECODE DLSAP */
          int sap_len = interface -> dlpi_sap_length;
          int phys_len = interface -> hw_address.hlen - 1;

          if (hfrom && (srcaddrlen == ABS (sap_len) + phys_len )) {
            hfrom -> hbuf [0] = interface -> hw_address.hbuf [0];
            hfrom -> hlen = interface -> hw_address.hlen;
            
            if (sap_len < 0) {
              memcpy ((char *) &hfrom -> hbuf [1], srcaddr, phys_len);
            }
            else {
              memcpy ((char *) &hfrom -> hbuf [1], (char *) &srcaddr [phys_len],
                phys_len);
            }
          } 
          else if (hfrom) {
            memset (hfrom, '\0', sizeof *hfrom);
          }
        } /* DECODE_DLSAP */

# endif /* !defined (USE_DLPI_RAW) */

	/* Decode the IP and UDP headers... */
	bufix = 0;
#ifdef USE_DLPI_RAW
	/* Decode the physical header... */
	offset = decode_hw_header (interface, dbuf, bufix, hfrom);

	/* If a physical layer checksum failed (dunno of any
	   physical layer that supports this, but WTH), skip this
	   packet. */
	if (offset < 0) {
		return 0;
	}
	bufix += offset;
	length -= offset;
#endif
	offset = decode_udp_ip_header (interface, dbuf, bufix,
				       from, (unsigned char *)0, length);

	/* If the IP or UDP checksum was bad, skip the packet... */
	if (offset < 0) {
	    return 0;
	}

	bufix += offset;
	length -= offset;

	/* Copy out the data in the packet... */
	memcpy (buf, &dbuf [bufix], length);
	return length;
}
#endif

/* Common DLPI routines ...
 *
 * Written by Eric James Negaard, <[e-mail]>
 *
 * Based largely in part to the example code contained in the document
 * "How to Use the STREAMS Data Link Provider Interface (DLPI)", written
 * by Neal Nuckolls of SunSoft Internet Engineering.
 * 
 * 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.
 * 
 * The usual disclaimers apply.  This code works for me.  Don't blame me
 * if it makes your machine or network go down in flames.  That taken
 * into consideration, use this code as you wish.  If you make usefull
 * modifications I'd appreciate hearing about it.
 */

#define DLPI_MAXWAIT		15	/* Max timeout */


/*
 * Parse an interface name and extract the unit number
 */

static int dlpiunit (ifname)
	char *ifname;
{
	int fd;
	char *cp, *dp, *ep;
	int unit;
	
	if (!ifname) {
		return 0;
	}
	
	/* Advance to the end of the name */
	cp = ifname;
	while (*cp) cp++;
	/* Back up to the start of the first digit */
	while ((*(cp-1) >= '0' && *(cp-1) <= '9') || *(cp - 1) == ':') cp--;
	
	/* Convert the unit number */
	unit = 0;
	while (*cp >= '0' && *cp <= '9') {
		unit *= 10;
		unit += (*cp++ - '0');
	}
	
	return unit;
}

/*
 * dlpiopen - open the DLPI device for a given interface name
 */
static int dlpiopen (ifname)
	char *ifname;
{
	char devname [50];
	char *cp, *dp, *ep;
	
	if (!ifname) {
		return -1;
	}
	
	/* Open a DLPI device */
	if (*ifname == '/') {
		dp = devname;
	} else {
		/* Prepend the device directory */
		memcpy (devname, DLPI_DEVDIR, strlen (DLPI_DEVDIR));
		dp = &devname [strlen (DLPI_DEVDIR)];
	}

	/* Find the end of the interface name */
	ep = cp = ifname;
	while (*ep)
		ep++;
	/* And back up to the first digit (unit number) */
	while ((*(ep - 1) >= '0' && *(ep - 1) <= '9') || *(ep - 1) == ':')
		ep--;
	
	/* Copy everything up to the unit number */
	while (cp < ep) {
		*dp++ = *cp++;
	}
	*dp = '\0';
	
	return open (devname, O_RDWR, 0);
}

/*
 * dlpiinforeq - request information about the data link provider.
 */

static int dlpiinforeq (fd)
	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;
	
	return putmsg (fd, &ctl, (struct strbuf *)NULL, flags);
}

/*
 * dlpiphysaddrreq - request the current physical address.
 */
static int dlpiphysaddrreq (fd, addrtype)
	int fd;
	unsigned long addrtype;
{
	dl_phys_addr_req_t physaddr_req;
	struct strbuf ctl;
	int flags;
	
	physaddr_req.dl_primitive = DL_PHYS_ADDR_REQ;
	physaddr_req.dl_addr_type = addrtype;
	
	ctl.maxlen = 0;
	ctl.len = sizeof (physaddr_req);
	ctl.buf = (char *)&physaddr_req;
	
	flags = RS_HIPRI;
	
	return putmsg (fd, &ctl, (struct strbuf *)NULL, flags);
}

/*
 * dlpiattachreq - send a request to attach to a specific unit.
 */
static int dlpiattachreq (fd, ppa)
	unsigned long ppa;
	int fd;
{
	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;
	
	return putmsg (fd, &ctl, (struct strbuf*)NULL, flags);
}

/*
 * dlpibindreq - send a request to bind to a specific SAP address.
 */
static int dlpibindreq (fd, sap, max_conind, service_mode, conn_mgmt, xidtest)
	unsigned long sap;
	unsigned long max_conind;
	unsigned long service_mode;
	unsigned long conn_mgmt;
	unsigned long xidtest;
	int fd;
{
	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;
	
	return putmsg (fd, &ctl, (struct strbuf*)NULL, flags);
}

/*
 * dlpiunbindreq - send a request to unbind.
 */
static int dlpiunbindreq (fd)
	int fd;