1 /* $OpenBSD: trap.c,v 1.36 2020/09/06 15:51:28 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/types.h> 21 #include <sys/stat.h> 22 #include <sys/socket.h> 23 #include <sys/un.h> 24 #include <sys/tree.h> 25 26 #include <net/if.h> 27 #include <netinet/in.h> 28 #include <arpa/inet.h> 29 30 #include <stdlib.h> 31 #include <stdio.h> 32 #include <errno.h> 33 #include <event.h> 34 #include <fcntl.h> 35 #include <string.h> 36 #include <unistd.h> 37 #include <pwd.h> 38 39 #include "snmpd.h" 40 #include "mib.h" 41 42 void 43 trap_init(void) 44 { 45 struct ber_oid trapoid = OID(MIB_coldStart); 46 47 /* 48 * Send a coldStart to notify that the daemon has been 49 * started and re-initialized. 50 */ 51 trap_send(&trapoid, NULL); 52 } 53 54 int 55 trap_send(struct ber_oid *oid, struct ber_element *elm) 56 { 57 int ret = 0, s; 58 struct trap_address *tr; 59 struct ber_element *root, *b, *c, *trap; 60 struct ber ber; 61 char *cmn; 62 ssize_t len; 63 u_int8_t *ptr; 64 struct ber_oid uptime = OID(MIB_sysUpTime); 65 struct ber_oid trapoid = OID(MIB_snmpTrapOID); 66 char ostr[SNMP_MAX_OID_STRLEN]; 67 struct oid oa, ob; 68 69 if (TAILQ_EMPTY(&snmpd_env->sc_trapreceivers)) 70 return (0); 71 72 smi_scalar_oidlen(&uptime); 73 smi_scalar_oidlen(&trapoid); 74 smi_scalar_oidlen(oid); 75 76 smi_oid2string(oid, ostr, sizeof(ostr), 0); 77 log_debug("trap_send: oid %s", ostr); 78 79 /* Setup OIDs to compare against the trap receiver MIB */ 80 bzero(&oa, sizeof(oa)); 81 bcopy(oid->bo_id, &oa.o_oid, sizeof(oa.o_oid)); 82 oa.o_oidlen = oid->bo_n; 83 bzero(&ob, sizeof(ob)); 84 ob.o_flags = OID_TABLE; 85 86 /* Add mandatory varbind elements */ 87 trap = ober_add_sequence(NULL); 88 c = ober_printf_elements(trap, "{Odt}{OO}", 89 &uptime, smi_getticks(), 90 BER_CLASS_APPLICATION, SNMP_T_TIMETICKS, 91 &trapoid, oid); 92 if (elm != NULL) 93 ober_link_elements(c, elm); 94 95 bzero(&ber, sizeof(ber)); 96 97 TAILQ_FOREACH(tr, &snmpd_env->sc_trapreceivers, entry) { 98 if (tr->sa_oid != NULL && tr->sa_oid->bo_n) { 99 /* The trap receiver may want only a specified MIB */ 100 bcopy(&tr->sa_oid->bo_id, &ob.o_oid, 101 sizeof(ob.o_oid)); 102 ob.o_oidlen = tr->sa_oid->bo_n; 103 if (smi_oid_cmp(&oa, &ob) != 0) 104 continue; 105 } 106 107 if ((s = snmpd_socket_af(&tr->ss, SOCK_DGRAM)) == -1) { 108 ret = -1; 109 goto done; 110 } 111 if (tr->ss_local.ss_family != 0) { 112 if (bind(s, (struct sockaddr *)&(tr->ss_local), 113 tr->ss_local.ss_len) == -1) { 114 ret = -1; 115 goto done; 116 } 117 } 118 119 cmn = tr->sa_community != NULL ? 120 tr->sa_community : snmpd_env->sc_trcommunity; 121 122 /* SNMP header */ 123 root = ober_add_sequence(NULL); 124 b = ober_printf_elements(root, "ds{tddd", 125 SNMP_V2, cmn, BER_CLASS_CONTEXT, SNMP_C_TRAPV2, 126 arc4random(), 0, 0); 127 ober_link_elements(b, trap); 128 129 #ifdef DEBUG 130 smi_debug_elements(root); 131 #endif 132 len = ober_write_elements(&ber, root); 133 if (ober_get_writebuf(&ber, (void *)&ptr) > 0 && 134 sendto(s, ptr, len, 0, (struct sockaddr *)&tr->ss, 135 tr->ss.ss_len) != -1) { 136 snmpd_env->sc_stats.snmp_outpkts++; 137 ret++; 138 } 139 140 close(s); 141 ober_unlink_elements(b); 142 ober_free_elements(root); 143 } 144 145 done: 146 ober_free_elements(trap); 147 ober_free(&ber); 148 149 return (ret); 150 } 151