arp.c

wm PNE 3.3 source code, running at more than vxworks6.x version.

	SNMP_PKT_T *	SNMP packet currently being processed.
	VB_T *		Variable being processed.

RETURNS: void

****************************************************************************/
void
  arptable_test(OIDC_T		 last_match,
		int		 tcount,
		OIDC_T		*tlist,
		SNMP_PKT_T	*pktp,
		VB_T		*vbp)
{
struct in_addr ipaddr;
atab_t *tab;
int i;
OIDC_T iface;

/* Check that the oid is well formed, it must have 6 unused components,
   be a request for the IP protocol, the ip address must be realistic,
   and we need to be able to read the arp table */
if ((tcount != AT_INSTANCE_LEN) || (*(tlist+AT_PROT) != 1) ||
    (oid_to_ip(4, tlist+AT_ADDR, &ipaddr.s_addr) != 0)) {
    setproc_error(pktp, vbp, NO_CREATION);
    return;
    }

if (read_arptab(0) == -1) {
    testproc_error(pktp, vbp, GEN_ERR);
    return;
    }

/* Look up entry */
iface = tlist[AT_INTERFACE];
for (tab = atabp, i = 0; i < atab_cnt; i++, tab++) {
    if ((ipaddr.s_addr == tab->a_iaddr.s_addr) && (iface == tab->a_ifnum)) {
	testproc_good(pktp, vbp);
	return;
	}
    }
testproc_error(pktp, vbp, NO_CREATION);
return;
}

/****************************************************************************
NAME:  arptable_next

PURPOSE:  Locate the "next" object in the ARP table

PARAMETERS:
	OIDC_T		Last component of the object id leading to
			the leaf node in the MIB.  This is usually
			the identifier for the particular attribute
			in the table.
	int		Number of components in the unused part of the
			object identifier
	OIDC_T *	Unused part of the object identifier
	SNMP_PKT_T *	SNMP packet currently being processed.
	VB_T *		Variable being processed.

RETURNS: void

****************************************************************************/
/*ARGSUSED*/
void
  arptable_next(OIDC_T		 last_match,
		int		 tcount,
		OIDC_T		*tlist,
		SNMP_PKT_T	*pktp,
		VB_T		*vbp)
{
atab_t *tab, *best = 0;
OIDC_T	bra[AT_INSTANCE_LEN], vra[AT_INSTANCE_LEN];
int	i, j;
struct in_addr	vaddr;

if (read_arptab(0) == -1) {
    nextproc_no_next(pktp, vbp);
    return;
    }

/* Now find the lowest value larger than the given one */
vra[AT_PROT] = 1;		/* Only IP supported by ARP. */
for (tab = atabp, i = atab_cnt; i; i--, tab++) {
    vaddr.s_addr = tab->a_iaddr.s_addr;
    ip_to_rlist(vaddr.s_addr, vra+AT_ADDR);
    vra[AT_INTERFACE] = tab->a_ifnum;
	
    if (oidcmp2(AT_INSTANCE_LEN, vra, tcount, tlist) <= 0)
	continue;

    if (!best || (oidorder(vra, bra, AT_INSTANCE_LEN) < 0)) {
	best = tab;
	for (j = 0; j < AT_INSTANCE_LEN; j++)
	    bra[j] = vra[j];
	}
    }

if (best) {
    /* dig out the information */
    get_arpinfo(last_match, pktp, vbp, best);

    /* and create the instance information */
    nextproc_next_instance(pktp, vbp, AT_INSTANCE_LEN, bra);
    }
else {
    /* no next found */
    nextproc_no_next(pktp, vbp);
    }

return;
}

void
  get_n2minfo(OIDC_T		 last_match,
	      SNMP_PKT_T	*pktp,
	      VB_T		*vbp,
	      atab_t		*tab)
{
switch(last_match) {
    case n2mIfIndex:
	getproc_got_int32(pktp, vbp, tab->a_ifnum);
	break;
    case n2mPhysAddress:
	getproc_got_string(pktp, vbp, 6, tab->a_enaddr.ether_addr_octet,
			   0, VT_STRING);
	break;
    case n2mNetAddress:
	getproc_got_ip_address(pktp, vbp, tab->a_iaddr.s_addr);
	break;
    case n2mType:
	/* we only allow dynamic (3) for type */
	getproc_got_int32(pktp, vbp, 3);
	break;
    }
}

/****************************************************************************
NAME:  n2mtable_get

PURPOSE:  Find the appropriate entry in the arp table and attach information
	  from it to the vbp using the getproc_got_* functions.
	  If we can't find an entry indicate that by calling getproc_nosuchins.

PARAMETERS:
	OIDC_T		Last component of the object id leading to
			the leaf node in the MIB.  This is usually
			the identifier for the particular attribute
			in the table.
	int		Number of components in the unused part of the
			object identifier
	OIDC_T *	Unused part of the object identifier
	SNMP_PKT_T *	SNMP packet currently being processed.
	VB_T *		Variable being processed.

RETURNS: void

****************************************************************************/
/*ARGSUSED*/
void
  n2mtable_get(OIDC_T		 last_match,
	       int		 tcount,
	       OIDC_T		*tlist,
	       SNMP_PKT_T	*pktp,
	       VB_T		*vbp)
{
struct in_addr ipaddr;
atab_t *tab;
int i;
OIDC_T iface;

/* Check that the oid is well formed, it must have 5 unused components,
   the ip address must be realistic, and we need to be able to read the
   arp table */
if ((tcount != N2M_INSTANCE_LEN) ||
    (oid_to_ip(4, tlist + N2M_ADDR, &ipaddr.s_addr) != 0) ||
    (read_arptab(0) == -1)) {
    getproc_nosuchins(pktp, vbp);
    return;
    }

/* Look up entry and call get_n2minfo to fill in the vbp */
iface = tlist[N2M_INTERFACE];
for (tab = atabp, i = 0; i < atab_cnt; i++, tab++) {
    if ((ipaddr.s_addr == tab->a_iaddr.s_addr) && (iface == tab->a_ifnum)) {
	get_n2minfo(last_match, pktp, vbp, tab);
	return;
	}
    }

/* We fall through to here if there are no entries that match the request */
getproc_nosuchins(pktp, vbp);
return;
}

/****************************************************************************
NAME:  n2mtable_test

PURPOSE:  Test whether a given object exists in the ARP table

PARAMETERS:
	OIDC_T		Last component of the object id leading to
			the leaf node in the MIB.  This is usually
			the identifier for the particular attribute
			in the table.
	int		Number of components in the unused part of the
			object identifier
	OIDC_T *	Unused part of the object identifier
	SNMP_PKT_T *	SNMP packet currently being processed.
	VB_T *		Variable being processed.

RETURNS: void

****************************************************************************/
void
  n2mtable_test(OIDC_T		 last_match,
		int		 tcount,
		OIDC_T		*tlist,
		SNMP_PKT_T	*pktp,
		VB_T		*vbp)
{
struct in_addr ipaddr;
atab_t *tab;
int i;
OIDC_T iface;

/* See if the value is acceptable for the type */
if ((last_match == n2mType) &&
    ((vbp->value_u.v_number != 2) && (vbp->value_u.v_number != 3))) {
    testproc_error(pktp, vbp, WRONG_VALUE);
    return;
    }

/* Check that the oid is well formed, it must have 5 unused components,
   the ip address must be realistic, and we need to be able to read
   the arp table */
if ((tcount != N2M_INSTANCE_LEN) ||
    (oid_to_ip(4, tlist + N2M_ADDR, &ipaddr.s_addr) != 0)) {
    setproc_error(pktp, vbp, NO_CREATION);
    return;
    }

if (read_arptab(0) == -1) {
    testproc_error(pktp, vbp, GEN_ERR);
    return;
    }

/* Look up entry */
iface = tlist[N2M_INTERFACE];
for (tab = atabp, i = 0; i < atab_cnt; i++, tab++) {
    if ((ipaddr.s_addr == tab->a_iaddr.s_addr) && (iface == tab->a_ifnum)) {
	/* we are happy, return */
	testproc_good(pktp, vbp);
	return;
	}
    }
testproc_error(pktp, vbp, NO_CREATION);
return;
}

/****************************************************************************
NAME:  n2mtable_next

PURPOSE:  Locate the "next" object in the ARP table

PARAMETERS:
	OIDC_T		Last component of the object id leading to
			the leaf node in the MIB.  This is usually
			the identifier for the particular attribute
			in the table.
	int		Number of components in the unused part of the
			object identifier
	OIDC_T *	Unused part of the object identifier
	SNMP_PKT_T *	SNMP packet currently being processed.
	VB_T *		Variable being processed.

RETURNS: void

****************************************************************************/
/*ARGSUSED*/
void
  n2mtable_next(OIDC_T		 last_match,
		int		 tcount,
		OIDC_T		*tlist,
		SNMP_PKT_T	*pktp,
		VB_T		*vbp)
{
atab_t *tab, *best = 0;
OIDC_T  bra[N2M_INSTANCE_LEN], vra[N2M_INSTANCE_LEN];
int	i, j;
struct in_addr	vaddr;

if (read_arptab(0) == -1) {
    nextproc_no_next(pktp, vbp);
    return;
    }

/* Now find the lowest value larger than the given one */
for (tab = atabp, i = atab_cnt; i; i--, tab++) {
    vaddr.s_addr = tab->a_iaddr.s_addr;
    ip_to_rlist(vaddr.s_addr, vra + N2M_ADDR);
    vra[N2M_INTERFACE] = tab->a_ifnum;
	
    if (oidcmp2(N2M_INSTANCE_LEN, vra, tcount, tlist) <= 0)
	continue;

    if (!best || (oidorder(vra, bra, N2M_INSTANCE_LEN) < 0)) {
	best = tab;
	for (j = 0; j < N2M_INSTANCE_LEN; j++)
	    bra[j] = vra[j];
	}
    }

if (best) {
    /* dig out the information */
    get_n2minfo(last_match, pktp, vbp, best);

    /* and create the instance information */
    nextproc_next_instance(pktp, vbp, N2M_INSTANCE_LEN, bra);
    }
else {
    /* no next found */
    nextproc_no_next(pktp, vbp);
    }

return;
}

/****************************************************************************
NAME:  set_n2mType

PURPOSE:  Perform the set of the net to media type, 

PARAMETERS:
	OIDC_T		Last component of the object id leading to
			the leaf node in the MIB.  This is usually
			the identifier for the particular attribute
			in the table.
	int		Number of components in the unused part of the
			object identifier
	OIDC_T *	Unused part of the object identifier
	SNMP_PKT_T *	SNMP packet currently being processed.
	VB_T *		Variable being processed.

RETURNS: void

****************************************************************************/
/*ARGSUSED*/
void
  set_n2mType(OIDC_T		 last_match,
	      int		 tcount,
	      OIDC_T		*tlist,
	      SNMP_PKT_T	*pktp,
	      VB_T		*vbp)
{
struct in_addr ipaddr;

/* We only have to do anything if the new value is "invalid" */
if (vbp->value_u.v_number == 2) {
    if (oid_to_ip(4, tlist + N2M_ADDR, &ipaddr.s_addr) == 0)
	zap_arp(ipaddr, (int)(tlist[N2M_INTERFACE]), 0, 0);
    }
setproc_good(pktp, vbp);
}

/****************************************************************************
NAME:  set_n2mPhysAddress

PURPOSE:  Perform the set of the arp address

PARAMETERS:
	OIDC_T		Last component of the object id leading to
			the leaf node in the MIB.  This is usually
			the identifier for the particular attribute
			in the table.
	int		Number of components in the unused part of the
			object identifier
	OIDC_T *	Unused part of the object identifier
	SNMP_PKT_T *	SNMP packet currently being processed.
	VB_T *		Variable being processed.

RETURNS: void

****************************************************************************/
/*ARGSUSED*/
void
  set_n2mPhysAddress(OIDC_T	 last_match,
		    int		 tcount,
		    OIDC_T	*tlist,
		    SNMP_PKT_T	*pktp,
		    VB_T	*vbp)
{
struct in_addr ipaddr;

if (oid_to_ip(4, tlist + N2M_ADDR, &ipaddr.s_addr) == 0)
    zap_arp(ipaddr, (int)(tlist[N2M_INTERFACE]),
	    (char *)EBufferStart(&vbp->value_u.v_string),
	    EBufferUsed(&vbp->value_u.v_string));
setproc_good(pktp, vbp);
return;
}

int
  arp_init()
{
if (find_loc(&arptab_size) == 0) return -1;
if (find_loc(&arptab) == 0) return -1;
krnl_atab_cnt = read_int((off_t)arptab_size.offset);
#ifdef DEBUG
printf("Kernel maintains %d ARP entries\n", krnl_atab_cnt);
#endif
krnl_atab_bytes = krnl_atab_cnt * sizeof(struct arptab);
if ((krnl_atab = (struct arptab *)malloc(krnl_atab_bytes)) == 0)
    return -1;

if ((atabp = (atab_t *)malloc(krnl_atab_cnt * sizeof(atab_t))) == 0) {
    free((char *)krnl_atab);
    return -1;
    }

return read_arptab(ARP_FORCE);
}