text: /*-
   * Copyright 1996 Massachusetts Institute of Technology
   *
   * Permission to use, copy, modify, and distribute this software and
   * its documentation for any purpose and without fee is hereby
   * granted, provided that both the above copyright notice and this
   * permission notice appear in all copies, that both the above
   * copyright notice and this permission notice appear in all
   * supporting documentation, and that the name of M.I.T. not be used
   * in advertising or publicity pertaining to distribution of the
   * software without specific, written prior permission.  M.I.T. makes
   * no representations about the suitability of this software for any
   * purpose.  It is provided "as is" without express or implied
   * warranty.
   * 
   * THIS SOFTWARE IS PROVIDED BY M.I.T. ``AS IS''.  M.I.T. DISCLAIMS
   * ALL EXPRESS OR IMPLIED WARRANTIES WITH REGARD TO THIS SOFTWARE,
   * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
   * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT
   * SHALL M.I.T. 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: soc2013/dpl/head/sys/net/if_mib.c 227590 2011-11-07 15:43:11Z ed $
   */
  
  #include <sys/param.h>
  #include <sys/systm.h>
  #include <sys/kernel.h>
  #include <sys/socket.h>
  #include <sys/sysctl.h>
  
  #include <net/if.h>
  #include <net/if_mib.h>
  #include <net/vnet.h>
  
  /*
   * A sysctl(3) MIB for generic interface information.  This information
   * is exported in the net.link.generic branch, which has the following
   * structure:
   *
   * net.link.generic	.system			- system-wide control variables
   *						  and statistics (node)
   *			.ifdata.<ifindex>.general
   *						- what's in `struct ifdata'
   *						  plus some other info
   *			.ifdata.<ifindex>.linkspecific
   *						- a link-type-specific data
   *						  structure (as might be used
   *						  by an SNMP agent
   *
   * Perhaps someday we will make addresses accessible via this interface
   * as well (then there will be four such...).  The reason that the
   * index comes before the last element in the name is because it
   * seems more orthogonal that way, particularly with the possibility
   * of other per-interface data living down here as well (e.g., integrated
   * services stuff).
   */
  
  SYSCTL_DECL(_net_link_generic);
  static SYSCTL_NODE(_net_link_generic, IFMIB_SYSTEM, system, CTLFLAG_RW, 0,
  	    "Variables global to all interfaces");
  
  SYSCTL_VNET_INT(_net_link_generic_system, IFMIB_IFCOUNT, ifcount, CTLFLAG_RD,
  	    &VNET_NAME(if_index), 0,
  	     "Number of configured interfaces");
  
  static int
  sysctl_ifdata(SYSCTL_HANDLER_ARGS) /* XXX bad syntax! */
  {
  	int *name = (int *)arg1;
  	int error;
  	u_int namelen = arg2;
  	struct ifnet *ifp;
  	struct ifmibdata ifmd;
  	size_t dlen;
  	char *dbuf;
  
  	if (namelen != 2)
  		return EINVAL;
  	if (name[0] <= 0)
  		return (ENOENT);
  	ifp = ifnet_byindex_ref(name[0]);
  	if (ifp == NULL)
  		return (ENOENT);
  
  	switch(name[1]) {
  	default:
  		error = ENOENT;
  		goto out;
  
  	case IFDATA_GENERAL:
  		bzero(&ifmd, sizeof(ifmd));
  		strlcpy(ifmd.ifmd_name, ifp->if_xname, sizeof(ifmd.ifmd_name));
  
  #define COPY(fld) ifmd.ifmd_##fld = ifp->if_##fld
  		COPY(pcount);
  		COPY(data);
  #undef COPY
  		ifmd.ifmd_flags = ifp->if_flags | ifp->if_drv_flags;
  		ifmd.ifmd_snd_len = ifp->if_snd.ifq_len;
  		ifmd.ifmd_snd_maxlen = ifp->if_snd.ifq_maxlen;
  		ifmd.ifmd_snd_drops = ifp->if_snd.ifq_drops;
  
  		error = SYSCTL_OUT(req, &ifmd, sizeof ifmd);
  		if (error || !req->newptr)
  			goto out;
  
  		error = SYSCTL_IN(req, &ifmd, sizeof ifmd);
  		if (error)
  			goto out;
  
  #define DONTCOPY(fld) ifmd.ifmd_data.ifi_##fld = ifp->if_data.ifi_##fld
  		DONTCOPY(type);
  		DONTCOPY(physical);
  		DONTCOPY(addrlen);
  		DONTCOPY(hdrlen);
  		DONTCOPY(mtu);
  		DONTCOPY(metric);
  		DONTCOPY(baudrate);
  #undef DONTCOPY
  #define COPY(fld) ifp->if_##fld = ifmd.ifmd_##fld
  		COPY(data);
  		ifp->if_snd.ifq_maxlen = ifmd.ifmd_snd_maxlen;
  		ifp->if_snd.ifq_drops = ifmd.ifmd_snd_drops;
  #undef COPY
  		break;
  
  	case IFDATA_LINKSPECIFIC:
  		error = SYSCTL_OUT(req, ifp->if_linkmib, ifp->if_linkmiblen);
  		if (error || !req->newptr)
  			goto out;
  
  		error = SYSCTL_IN(req, ifp->if_linkmib, ifp->if_linkmiblen);
  		if (error)
  			goto out;
  		break;
  
  	case IFDATA_DRIVERNAME:
  		/* 20 is enough for 64bit ints */
  		dlen = strlen(ifp->if_dname) + 20 + 1;
  		if ((dbuf = malloc(dlen, M_TEMP, M_NOWAIT)) == NULL) {
  			error = ENOMEM;
  			goto out;
  		}
  		if (ifp->if_dunit == IF_DUNIT_NONE)
  			strcpy(dbuf, ifp->if_dname);
  		else
  			sprintf(dbuf, "%s%d", ifp->if_dname, ifp->if_dunit);
  
  		error = SYSCTL_OUT(req, dbuf, strlen(dbuf) + 1);
  		if (error == 0 && req->newptr != NULL)
  			error = EPERM;
  		free(dbuf, M_TEMP);
  		goto out;
  	}
  out:
  	if_rele(ifp);
  	return error;
  }
  
  static SYSCTL_NODE(_net_link_generic, IFMIB_IFDATA, ifdata, CTLFLAG_RW,
  	    sysctl_ifdata, "Interface table");
  
  