freebsd-dev/sys/net/if_mib.c
Gleb Smirnoff 178b14d674 Remove ability to write to struct if_data residing in struct ifnet
via net.link.generic.IFMIB_IFDATA.*.IFDATA_GENERAL sysctl. Reasons
for removal are:
- No code in tree uses this possibility.
- The documentation ifmib(4) doesn't say that such possibility
  exist. The example provided in manual page only reads data.
- On many interfaces the feature simply doesn't work, since they
  do accounting in hardware, and overwrite if_data on tick.

Sponsored by:	Nginx, Inc.
2014-08-31 06:23:54 +00:00

152 lines
4.6 KiB
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/socket.h>
#include <sys/sysctl.h>
#include <net/if.h>
#include <net/if_var.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)
goto out;
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");