FreeBSD/Linux Kernel Cross Reference
sys/net/if_mib.c

     /*-
      * 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.
     *
     * $FreeBSD$
     */
    
    #include <sys/param.h>
    #include <sys/systm.h>
    #include <sys/kernel.h>
    #include <sys/malloc.h>
    #include <sys/socket.h>
    #include <sys/sysctl.h>
    
    #include <net/if.h>
    #include <net/if_var.h>
    #include <net/if_private.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).
     */
    
    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;
            struct epoch_tracker et;
            size_t dlen;
            char *dbuf;
    
            if (namelen != 2)
                    return EINVAL;
            if (name[0] <= 0)
                    return (ENOENT);
            NET_EPOCH_ENTER(et);
            ifp = ifnet_byindex_ref(name[0]);
            NET_EPOCH_EXIT(et);
            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));
    
                    ifmd.ifmd_pcount = ifp->if_pcount;
                   if_data_copy(ifp, &ifmd.ifmd_data);
   
                   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_get_counter(ifp, IFCOUNTER_OQDROPS);
   
                   error = SYSCTL_OUT(req, &ifmd, sizeof ifmd);
                   if (error)
                           goto out;
                   break;
   
           case IFDATA_LINKSPECIFIC:
                   error = SYSCTL_OUT(req, ifp->if_linkmib, ifp->if_linkmiblen);
                   if (error || !req->newptr)
                           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;
   }
   
   SYSCTL_DECL(_net_link_generic);
   static SYSCTL_NODE(_net_link_generic, IFMIB_IFDATA, ifdata,
       CTLFLAG_RD | CTLFLAG_MPSAFE, sysctl_ifdata,
       "Interface table");

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