mibII_ipaddr.c

/*
 * Copyright (c) 2001-2002
 *	Fraunhofer Institute for Open Communication Systems (FhG Fokus).
 *	All rights reserved.
 *
 * Author: Harti Brandt <[email protected]>
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS 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.
 *
 * $Begemot: bsnmp/snmp_mibII/mibII_ipaddr.c,v 1.10 2005/10/04 11:21:35 brandt_h Exp $
 *
 * IP address table. This table is writeable!
 *
 * Writing to this table will add a new IP address to the interface.
 * An address can be deleted with writing the interface index 0.
 */
#include "mibII.h"
#include "mibII_oid.h"

static const struct asn_oid
	oid_ipAddrTable = OIDX_ipAddrTable;

/*
 * Be careful not to hold any pointers during the SET processing - the
 * interface and address lists can be relocated at any time.
 */
struct update {
	struct snmp_dependency dep;

	uint32_t	set;
	struct in_addr	addr;
	struct in_addr	mask;
	int		bcast;
	u_int		ifindex;

	uint32_t	rb;
	struct in_addr	rb_mask;
	struct in_addr	rb_bcast;
};
#define UPD_IFINDEX	0x0001
#define UPD_MASK	0x0002
#define UPD_BCAST	0x0004
#define RB_CREATE	0x0001
#define RB_DESTROY	0x0002
#define RB_MODIFY	0x0004

/*
 * Create a new interface address
 */
static int
create(struct update *upd)
{
	struct in_addr bcast;
	struct mibifa *ifa;

	if (!(upd->set & UPD_MASK)) {
		if (IN_CLASSA(ntohl(upd->addr.s_addr)))
			upd->mask.s_addr = htonl(IN_CLASSA_NET);
		else if (IN_CLASSB(ntohl(upd->addr.s_addr)))
			upd->mask.s_addr = htonl(IN_CLASSB_NET);
		else if (IN_CLASSC(ntohl(upd->addr.s_addr)))
			upd->mask.s_addr = htonl(IN_CLASSC_NET);
		else
			upd->mask.s_addr = 0xffffffff;
	}

	bcast.s_addr = upd->addr.s_addr & upd->mask.s_addr;
	if (!(upd->set & UPD_BCAST) || upd->bcast) {
		uint32_t tmp = ~ntohl(upd->mask.s_addr);
		bcast.s_addr |= htonl(0xffffffff & ~tmp);
	}

	if ((ifa = mib_create_ifa(upd->ifindex, upd->addr, upd->mask, bcast))
	    == NULL)
		return (SNMP_ERR_GENERR);

	upd->rb |= RB_CREATE;
	return (SNMP_ERR_NOERROR);
}

/*
 * Modify the netmask or broadcast address. The ifindex cannot be
 * changed (obviously).
 */
static int
modify(struct update *upd, struct mibifa *ifa)
{
	struct mibif *ifp;

	if ((ifp = mib_find_if(ifa->ifindex)) == NULL)
		return (SNMP_ERR_WRONG_VALUE);
	if ((upd->set & UPD_IFINDEX) && upd->ifindex != ifa->ifindex)
		return (SNMP_ERR_INCONS_VALUE);

	upd->rb_mask = ifa->inmask;
	upd->rb_bcast = ifa->inbcast;
	if (((upd->set & UPD_MASK) && upd->mask.s_addr != ifa->inmask.s_addr) ||
	    (upd->set & UPD_BCAST)) {
		if (upd->set & UPD_MASK)
			ifa->inmask = upd->mask;
		if (upd->set & UPD_BCAST) {
			ifa->inbcast.s_addr = ifa->inaddr.s_addr
			    & ifa->inmask.s_addr;
			if (upd->bcast)
				ifa->inbcast.s_addr |= 0xffffffff
				    & ~ifa->inmask.s_addr;
		}
		if (mib_modify_ifa(ifa)) {
			syslog(LOG_ERR, "set netmask/bcast: %m");
			ifa->inmask = upd->rb_mask;
			ifa->inbcast = upd->rb_bcast;
			mib_unmodify_ifa(ifa);
			return (SNMP_ERR_GENERR);
		}
		upd->rb |= RB_MODIFY;
	}
	return (SNMP_ERR_NOERROR);
}

/*
 * Destroy the given row in the table. We remove the address from the
 * system, but keep the structure around for the COMMIT. It's deleted
 * only in the FINISH operation.
 */
static int
destroy(struct snmp_context *ctx __unused, struct update *upd,
    struct mibifa *ifa)
{
	if (mib_destroy_ifa(ifa))
		return (SNMP_ERR_GENERR);
	upd->rb |= RB_DESTROY;
	return (SNMP_ERR_NOERROR);
}

/*
 * This function is called to commit/rollback a SET on an IpAddrEntry
 */
static int
update_func(struct snmp_context *ctx, struct snmp_dependency *dep,
    enum snmp_depop op)
{
	struct update *upd = (struct update *)dep;
	struct mibifa *ifa;

	switch (op) {

	  case SNMP_DEPOP_COMMIT:
		if ((ifa = mib_find_ifa(upd->addr)) == NULL) {
			/* non existing entry - must have ifindex */
			if (!(upd->set & UPD_IFINDEX))
				return (SNMP_ERR_INCONS_NAME);
			return (create(upd));
		}
		/* existing entry */
		if ((upd->set & UPD_IFINDEX) && upd->ifindex == 0) {
			/* delete */
			return (destroy(ctx, upd, ifa));
		}
		/* modify entry */
		return (modify(upd, ifa));

	  case SNMP_DEPOP_ROLLBACK:
		if ((ifa = mib_find_ifa(upd->addr)) == NULL) {
			/* ups */
			mib_iflist_bad = 1;
			return (SNMP_ERR_NOERROR);
		}
		if (upd->rb & RB_CREATE) {
			mib_uncreate_ifa(ifa);
			return (SNMP_ERR_NOERROR);
		}
		if (upd->rb & RB_DESTROY) {
			mib_undestroy_ifa(ifa);
			return (SNMP_ERR_NOERROR);
		}
		if (upd->rb & RB_MODIFY) {
			ifa->inmask = upd->rb_mask;
			ifa->inbcast = upd->rb_bcast;
			mib_unmodify_ifa(ifa);
			return (SNMP_ERR_NOERROR);
		}
		return (SNMP_ERR_NOERROR);

	  case SNMP_DEPOP_FINISH:
		if ((upd->rb & RB_DESTROY) &&
		    (ifa = mib_find_ifa(upd->addr)) != NULL &&
		    (ifa->flags & MIBIFA_DESTROYED)) {
			TAILQ_REMOVE(&mibifa_list, ifa, link);
			free(ifa);
		}
		return (SNMP_ERR_NOERROR);
	}
	abort();
}

/**********************************************************************/
/*
 * ACTION
 */
int
op_ipaddr(struct snmp_context *ctx, struct snmp_value *value,
    u_int sub, u_int iidx, enum snmp_op op)
{
	asn_subid_t which;
	struct mibifa *ifa;
	struct update *upd;
	struct asn_oid idx;
	u_char ipaddr[4];

	which = value->var.subs[sub - 1];

	ifa = NULL;

	switch (op) {

	  case SNMP_OP_GETNEXT:
		if ((ifa = NEXT_OBJECT_OID(&mibifa_list, &value->var, sub)) == NULL)
			return (SNMP_ERR_NOSUCHNAME);
		index_append(&value->var, sub, &ifa->index);
		break;

	  case SNMP_OP_GET:
		if ((ifa = FIND_OBJECT_OID(&mibifa_list, &value->var, sub)) == NULL)
			return (SNMP_ERR_NOSUCHNAME);
		break;

	  case SNMP_OP_SET:
		if (index_decode(&value->var, sub, iidx, ipaddr))
			return (SNMP_ERR_NO_CREATION);
		ifa = FIND_OBJECT_OID(&mibifa_list, &value->var, sub);
		idx.len = 4;
		idx.subs[0] = ipaddr[0];
		idx.subs[1] = ipaddr[1];
		idx.subs[2] = ipaddr[2];
		idx.subs[3] = ipaddr[3];

		if ((upd = (struct update *)snmp_dep_lookup(ctx,
		    &oid_ipAddrTable, &idx, sizeof(*upd), update_func)) == NULL)
			return (SNMP_ERR_RES_UNAVAIL);

		upd->addr.s_addr = htonl((ipaddr[0] << 24) | (ipaddr[1] << 16) |
		    (ipaddr[2] << 8) | (ipaddr[3] << 0));

		switch (which) {

		  case LEAF_ipAdEntIfIndex:
			if (upd->set & UPD_IFINDEX)
				return (SNMP_ERR_INCONS_VALUE);
			if (value->v.integer < 0 ||
			    value->v.integer > 0x07fffffff)
				return (SNMP_ERR_WRONG_VALUE);
			if (ifa != NULL) {
				if (ifa->ifindex != (u_int)value->v.integer &&
				    value->v.integer != 0)
					return (SNMP_ERR_INCONS_VALUE);
			}
			upd->set |= UPD_IFINDEX;
			upd->ifindex = (u_int)value->v.integer;
			break;

		  case LEAF_ipAdEntNetMask:
			if (upd->set & UPD_MASK)
				return (SNMP_ERR_INCONS_VALUE);
			upd->mask.s_addr = htonl((value->v.ipaddress[0] << 24)
			    | (value->v.ipaddress[1] << 16)
			    | (value->v.ipaddress[2] << 8)
			    | (value->v.ipaddress[3] << 0));
			upd->set |= UPD_MASK;
			break;

		  case LEAF_ipAdEntBcastAddr:
			if (upd->set & UPD_BCAST)
				return (SNMP_ERR_INCONS_VALUE);
			if (value->v.integer != 0 && value->v.integer != 1)
				return (SNMP_ERR_WRONG_VALUE);
			upd->bcast = value->v.integer;
			upd->set |= UPD_BCAST;
			break;

		}
		return (SNMP_ERR_NOERROR);

	  case SNMP_OP_ROLLBACK:
	  case SNMP_OP_COMMIT:
		return (SNMP_ERR_NOERROR);
	}

	switch (which) {

	  case LEAF_ipAdEntAddr:
		value->v.ipaddress[0] = ifa->index.subs[0];
		value->v.ipaddress[1] = ifa->index.subs[1];
		value->v.ipaddress[2] = ifa->index.subs[2];
		value->v.ipaddress[3] = ifa->index.subs[3];
		break;

	  case LEAF_ipAdEntIfIndex:
		if (ifa->flags & MIBIFA_DESTROYED)
			value->v.integer = 0;
		else
			value->v.integer = ifa->ifindex;
		break;

	  case LEAF_ipAdEntNetMask:
		value->v.ipaddress[0] = (ntohl(ifa->inmask.s_addr) >> 24) & 0xff;
		value->v.ipaddress[1] = (ntohl(ifa->inmask.s_addr) >> 16) & 0xff;
		value->v.ipaddress[2] = (ntohl(ifa->inmask.s_addr) >>  8) & 0xff;
		value->v.ipaddress[3] = (ntohl(ifa->inmask.s_addr) >>  0) & 0xff;
		break;

	  case LEAF_ipAdEntBcastAddr:
		value->v.integer = ntohl(ifa->inbcast.s_addr) & 1;
		break;


	  case LEAF_ipAdEntReasmMaxSize:
		value->v.integer = 65535;
		break;
	}
	return (SNMP_ERR_NOERROR);
}