1 /* $OpenBSD: trap.c,v 1.43 2024/02/06 15:36:11 martijn Exp $ */
2
3 /*
4 * Copyright (c) 2008 Reyk Floeter <reyk@openbsd.org>
5 *
6 * Permission to use, copy, modify, and distribute this software for any
7 * purpose with or without fee is hereby granted, provided that the above
8 * copyright notice and this permission notice appear in all copies.
9 *
10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17 */
18
19 #include <sys/queue.h>
20 #include <sys/socket.h>
21
22 #include <ber.h>
23 #include <stdint.h>
24 #include <stdlib.h>
25 #include <string.h>
26
27 #include "log.h"
28 #include "mib.h"
29 #include "smi.h"
30 #include "snmp.h"
31 #include "snmpd.h"
32
33 void
trap_init(void)34 trap_init(void)
35 {
36 /*
37 * Send a coldStart to notify that the daemon has been
38 * started and re-initialized.
39 */
40 trap_send(&OID(MIB_coldStart), NULL);
41 }
42
43 int
trap_send(struct ber_oid * oid,struct ber_element * elm)44 trap_send(struct ber_oid *oid, struct ber_element *elm)
45 {
46 struct trap_address *tr;
47 struct ber_element *vblist, *trap;
48 struct ber_oid uptime = OID(MIB_sysUpTime, 0);
49 struct ber_oid trapoid = OID(MIB_snmpTrapOID, 0);
50 char ostr[SNMP_MAX_OID_STRLEN];
51 struct snmp_message *msg;
52 int r;
53
54 if (TAILQ_EMPTY(&snmpd_env->sc_trapreceivers))
55 return (0);
56
57 mib_oid2string(oid, ostr, sizeof(ostr), snmpd_env->sc_oidfmt);
58 log_debug("trap_send: oid %s", ostr);
59
60 /* Add mandatory varbind elements */
61 trap = ober_add_sequence(NULL);
62 vblist = ober_printf_elements(trap, "{Odt}{OO}",
63 &uptime, smi_getticks(),
64 BER_CLASS_APPLICATION, SNMP_T_TIMETICKS,
65 &trapoid, oid);
66 if (elm != NULL)
67 ober_link_elements(vblist, elm);
68
69 TAILQ_FOREACH(tr, &snmpd_env->sc_trapreceivers, entry) {
70 if (tr->ta_oid.bo_n) {
71 /* The trap receiver may want only a specified MIB */
72 r = ober_oid_cmp(oid, &tr->ta_oid);
73 if (r != 0 && r != 2)
74 continue;
75 }
76
77 if ((msg = calloc(1, sizeof(*msg))) == NULL)
78 fatal("malloc");
79 msg->sm_sock = snmpd_socket_af(&tr->ta_ss, SOCK_DGRAM);
80 if (msg->sm_sock == -1) {
81 log_warn("socket");
82 free(msg);
83 continue;
84 }
85 memcpy(&(msg->sm_ss), &(tr->ta_ss), sizeof(msg->sm_ss));
86 msg->sm_slen = tr->ta_ss.ss_len;
87 if (tr->ta_sslocal.ss_family != 0) {
88 memcpy(&(msg->sm_local_ss), &(tr->ta_sslocal),
89 sizeof(msg->sm_local_ss));
90 msg->sm_local_slen = tr->ta_sslocal.ss_len;
91 }
92 msg->sm_version = tr->ta_version;
93 msg->sm_pdutype = SNMP_C_TRAPV2;
94 ober_set_application(&msg->sm_ber, smi_application);
95 msg->sm_request = arc4random();
96 if ((msg->sm_varbindresp = ober_dup(trap->be_sub)) == NULL)
97 fatal("malloc");
98
99 switch (msg->sm_version) {
100 case SNMP_V2:
101 (void)strlcpy(msg->sm_community, tr->ta_community,
102 sizeof(msg->sm_community));
103 break;
104 case SNMP_V3:
105 msg->sm_msgid = msg->sm_request & INT32_MAX;
106 msg->sm_max_msg_size = READ_BUF_SIZE;
107 msg->sm_flags = tr->ta_seclevel != -1 ?
108 tr->ta_seclevel : snmpd_env->sc_min_seclevel;
109 msg->sm_secmodel = SNMP_SEC_USM;
110 msg->sm_engine_time = snmpd_engine_time();
111 msg->sm_engine_boots = snmpd_env->sc_engine_boots;
112 memcpy(msg->sm_ctxengineid, snmpd_env->sc_engineid,
113 snmpd_env->sc_engineid_len);
114 msg->sm_ctxengineid_len =
115 snmpd_env->sc_engineid_len;
116 (void)strlcpy(msg->sm_username, tr->ta_usmusername,
117 sizeof(msg->sm_username));
118 msg->sm_user = tr->ta_usmuser;
119 arc4random_buf(msg->sm_salt, sizeof(msg->sm_salt));
120 break;
121 }
122
123 snmpe_response(msg);
124 }
125 ober_free_elements(trap);
126
127 return 0;
128 }
129