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/* $OpenBSD: trap.c,v 1.21 2013/10/19 14:18:39 blambert Exp $ */
/*
* Copyright (c) 2008 Reyk Floeter <reyk@openbsd.org>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include <sys/queue.h>
#include <sys/param.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <sys/tree.h>
#include <net/if.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <stdlib.h>
#include <stdio.h>
#include <errno.h>
#include <event.h>
#include <fcntl.h>
#include <string.h>
#include <unistd.h>
#include <pwd.h>
#include "snmpd.h"
#include "mib.h"
extern struct snmpd *env;
void
trap_init(void)
{
struct ber_oid trapoid = OID(MIB_coldStart);
/*
* Send a coldStart to notify that the daemon has been
* started and re-initialized.
*/
trap_send(&trapoid, NULL);
}
int
trap_imsg(struct imsgev *iev, pid_t pid)
{
struct imsgbuf *ibuf;
struct imsg imsg;
int ret = -1, n, x = 0, state = 0;
int done = 0;
struct snmp_imsg *sm;
u_int32_t d;
u_int64_t l;
u_int8_t *c;
char ostr[SNMP_MAX_OID_LEN];
struct ber_element *ber = NULL, *varbind = NULL, *a;
size_t len = 0;
struct ber_oid o;
ibuf = &iev->ibuf;
while (!done) {
while (!done) {
if ((n = imsg_get(ibuf, &imsg)) == -1)
goto done;
if (n == 0)
break;
switch (imsg.hdr.type) {
case IMSG_SNMP_ELEMENT:
if (imsg.hdr.len < (IMSG_HEADER_SIZE +
sizeof(struct snmp_imsg)))
goto imsgdone;
sm = (struct snmp_imsg *)imsg.data;
if (!state++) {
/* First element must be the trap OID */
if (sm->snmp_type != SNMP_NULL)
goto imsgdone;
ber_string2oid(sm->snmp_oid, &o);
break;
}
ber = ber_add_sequence(ber);
if (varbind == NULL)
varbind = ber;
a = ber_add_oidstring(ber, sm->snmp_oid);
switch (sm->snmp_type) {
case SNMP_OBJECT:
if (sm->snmp_len > sizeof(ostr) - 1)
goto imsgdone;
bzero(&ostr, sizeof(ostr));
bcopy(sm + 1, &ostr, sm->snmp_len);
a = ber_add_oidstring(a, ostr);
break;
case SNMP_BITSTRING:
if (sm->snmp_len < 1)
goto imsgdone;
/* FALLTHROUGH */
case SNMP_OCTETSTRING:
case SNMP_IPADDR:
if (sm->snmp_len >= SNMPD_MAXSTRLEN)
goto imsgdone;
c = (u_int8_t *)(sm + 1);
if (sm->snmp_type == SNMP_BITSTRING)
a = ber_add_bitstring(a, c,
sm->snmp_len);
else
a = ber_add_nstring(a, c,
sm->snmp_len);
break;
case SNMP_NULL:
a = ber_add_null(a);
break;
case SNMP_INTEGER32:
case SNMP_COUNTER32:
case SNMP_GAUGE32:
case SNMP_TIMETICKS:
case SNMP_OPAQUE:
case SNMP_UINTEGER32:
if (sm->snmp_len != sizeof(d))
goto imsgdone;
bcopy(sm + 1, &d, sm->snmp_len);
a = ber_add_integer(a, d);
break;
case SNMP_COUNTER64:
if (sm->snmp_len != sizeof(l))
goto imsgdone;
bcopy(sm + 1, &l, sm->snmp_len);
a = ber_add_integer(a, l);
break;
default:
log_debug("trap_imsg: illegal type %d",
sm->snmp_type);
imsg_free(&imsg);
goto imsgdone;
}
switch (sm->snmp_type) {
case SNMP_INTEGER32:
case SNMP_BITSTRING:
case SNMP_OCTETSTRING:
case SNMP_NULL:
case SNMP_OBJECT:
/* universal types */
break;
default:
/* application-specific types */
ber_set_header(a, BER_CLASS_APPLICATION,
sm->snmp_type);
break;
}
x++;
break;
case IMSG_SNMP_END:
done = 1;
break;
default:
log_debug("trap_imsg: illegal imsg %d",
imsg.hdr.type);
goto imsgdone;
}
imsg_free(&imsg);
}
if (done)
break;
if ((n = imsg_read(ibuf)) == -1)
goto done;
if (n == 0)
goto done;
}
if (varbind != NULL)
len = ber_calc_len(varbind);
log_debug("trap_imsg: from pid %u len %d elements %d",
pid, len, x);
trap_send(&o, varbind);
return (0);
imsgdone:
imsg_free(&imsg);
done:
if (varbind != NULL)
ber_free_elements(varbind);
return (ret);
}
int
trap_send(struct ber_oid *oid, struct ber_element *elm)
{
int ret = 0, s;
struct address *tr;
struct ber_element *root, *b, *c, *trap;
struct ber ber;
char *cmn;
ssize_t len;
u_int8_t *ptr;
struct ber_oid uptime = OID(MIB_sysUpTime);
struct ber_oid trapoid = OID(MIB_snmpTrapOID);
char ostr[SNMP_MAX_OID_LEN];
struct oid oa, ob;
if (TAILQ_EMPTY(&env->sc_trapreceivers))
return (0);
smi_scalar_oidlen(&uptime);
smi_scalar_oidlen(&trapoid);
smi_scalar_oidlen(oid);
smi_oid2string(oid, ostr, sizeof(ostr), 0);
log_debug("trap_send: oid %s", ostr);
/* Setup OIDs to compare against the trap receiver MIB */
bzero(&oa, sizeof(oa));
bcopy(oid->bo_id, &oa.o_oid, sizeof(oa.o_oid));
oa.o_oidlen = oid->bo_n;
bzero(&ob, sizeof(ob));
ob.o_flags = OID_TABLE;
/* Add mandatory varbind elements */
trap = ber_add_sequence(NULL);
c = ber_printf_elements(trap, "{Odt}{OO}",
&uptime, smi_getticks(),
BER_CLASS_APPLICATION, SNMP_T_TIMETICKS,
&trapoid, oid);
if (elm != NULL)
ber_link_elements(c, elm);
bzero(&ber, sizeof(ber));
ber.fd = -1;
TAILQ_FOREACH(tr, &env->sc_trapreceivers, entry) {
if (tr->sa_oid != NULL && tr->sa_oid->bo_n) {
/* The trap receiver may want only a specified MIB */
bcopy(&tr->sa_oid->bo_id, &ob.o_oid,
sizeof(ob.o_oid));
ob.o_oidlen = tr->sa_oid->bo_n;
if (smi_oid_cmp(&oa, &ob) != 0)
continue;
}
if ((s = snmpd_socket_af(&tr->ss, htons(tr->port))) == -1) {
ret = -1;
goto done;
}
cmn = tr->sa_community != NULL ?
tr->sa_community : env->sc_trcommunity;
/* SNMP header */
root = ber_add_sequence(NULL);
b = ber_printf_elements(root, "ds{tddd",
SNMP_V2, cmn, BER_CLASS_CONTEXT, SNMP_C_TRAPV2,
arc4random(), 0, 0);
ber_link_elements(b, trap);
#ifdef DEBUG
smi_debug_elements(root);
#endif
len = ber_write_elements(&ber, root);
if (ber_get_writebuf(&ber, (void *)&ptr) > 0 &&
sendto(s, ptr, len, 0, (struct sockaddr *)&tr->ss,
tr->ss.ss_len) != -1) {
env->sc_stats.snmp_outpkts++;
ret++;
}
close(s);
ber_unlink_elements(b);
ber_free_elements(root);
}
done:
ber_free_elements(trap);
ber_free(&ber);
return (ret);
}
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