1 /* 2 * Copyright (c) 2001-2003 3 * Fraunhofer Institute for Open Communication Systems (FhG Fokus). 4 * All rights reserved. 5 * 6 * Author: Harti Brandt <harti@freebsd.org> 7 * Kendy Kutzner 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 18 * THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS ``AS IS'' AND 19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21 * ARE DISCLAIMED. IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE 22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28 * SUCH DAMAGE. 29 * 30 * $Begemot: bsnmp/lib/snmpclient.h,v 1.19 2005/05/23 11:10:14 brandt_h Exp $ 31 */ 32 #ifndef _BSNMP_SNMPCLIENT_H 33 #define _BSNMP_SNMPCLIENT_H 34 35 #include <sys/types.h> 36 #include <sys/socket.h> 37 #include <sys/time.h> 38 #include <netinet/in.h> 39 #include <stddef.h> 40 41 42 #define SNMP_STRERROR_LEN 200 43 44 #define SNMP_LOCAL_PATH "/tmp/snmpXXXXXXXXXXXXXX" 45 46 /* 47 * transport methods 48 */ 49 #define SNMP_TRANS_UDP 0 50 #define SNMP_TRANS_LOC_DGRAM 1 51 #define SNMP_TRANS_LOC_STREAM 2 52 #define SNMP_TRANS_UDP6 3 53 54 /* type of callback function for responses 55 * this callback function is responsible for free() any memory associated with 56 * any of the PDUs. Therefor it may call snmp_pdu_free() */ 57 typedef void (*snmp_send_cb_f)(struct snmp_pdu *, struct snmp_pdu *, void *); 58 59 /* type of callback function for timeouts */ 60 typedef void (*snmp_timeout_cb_f)(void * ); 61 62 /* timeout start function */ 63 typedef void *(*snmp_timeout_start_f)(struct timeval *timeout, 64 snmp_timeout_cb_f callback, void *); 65 66 /* timeout stop function */ 67 typedef void (*snmp_timeout_stop_f)(void *timeout_id); 68 69 /* 70 * Client context. 71 */ 72 struct snmp_client { 73 enum snmp_version version; 74 int trans; /* which transport to use */ 75 76 /* these two are read-only for the application */ 77 char *cport; /* port number as string */ 78 char *chost; /* host name or IP address as string */ 79 80 char read_community[SNMP_COMMUNITY_MAXLEN + 1]; 81 char write_community[SNMP_COMMUNITY_MAXLEN + 1]; 82 83 /* SNMPv3 specific fields */ 84 int32_t identifier; 85 int32_t security_model; 86 struct snmp_engine engine; 87 struct snmp_user user; 88 89 /* SNMPv3 Access control - VACM*/ 90 uint32_t clen; 91 uint8_t cengine[SNMP_ENGINE_ID_SIZ]; 92 char cname[SNMP_CONTEXT_NAME_SIZ]; 93 94 struct timeval timeout; 95 u_int retries; 96 97 int dump_pdus; 98 99 size_t txbuflen; 100 size_t rxbuflen; 101 102 int fd; 103 104 int32_t next_reqid; 105 int32_t max_reqid; 106 int32_t min_reqid; 107 108 char error[SNMP_STRERROR_LEN]; 109 110 snmp_timeout_start_f timeout_start; 111 snmp_timeout_stop_f timeout_stop; 112 113 char local_path[sizeof(SNMP_LOCAL_PATH)]; 114 }; 115 116 /* the global context */ 117 extern struct snmp_client snmp_client; 118 119 /* initizialies a snmp_client structure */ 120 void snmp_client_init(struct snmp_client *); 121 122 /* initialize fields */ 123 int snmp_client_set_host(struct snmp_client *, const char *); 124 int snmp_client_set_port(struct snmp_client *, const char *); 125 126 /* open connection to snmp server (hostname or portname can be NULL) */ 127 int snmp_open(const char *_hostname, const char *_portname, 128 const char *_read_community, const char *_write_community); 129 130 /* close connection */ 131 void snmp_close(void); 132 133 /* initialize a snmp_pdu structure */ 134 void snmp_pdu_create(struct snmp_pdu *, u_int _op); 135 136 /* add pairs of (struct asn_oid *, enum snmp_syntax) to an existing pdu */ 137 int snmp_add_binding(struct snmp_pdu *, ...); 138 139 /* check wheater the answer is valid or not */ 140 int snmp_pdu_check(const struct snmp_pdu *_req, const struct snmp_pdu *_resp); 141 142 int32_t snmp_pdu_send(struct snmp_pdu *_pdu, snmp_send_cb_f _func, void *_arg); 143 144 /* append an index to an oid */ 145 int snmp_oid_append(struct asn_oid *_oid, const char *_fmt, ...); 146 147 /* receive a packet */ 148 int snmp_receive(int _blocking); 149 150 /* 151 * This structure is used to describe an SNMP table that is to be fetched. 152 * The C-structure that is produced by the fetch function must start with 153 * a TAILQ_ENTRY and an u_int64_t. 154 */ 155 struct snmp_table { 156 /* base OID of the table */ 157 struct asn_oid table; 158 /* type OID of the LastChange variable for the table if any */ 159 struct asn_oid last_change; 160 /* maximum number of iterations if table has changed */ 161 u_int max_iter; 162 /* size of the C-structure */ 163 size_t entry_size; 164 /* number of index fields */ 165 u_int index_size; 166 /* bit mask of required fields */ 167 uint64_t req_mask; 168 169 /* indexes and columns to fetch. Ended by a NULL syntax entry */ 170 struct snmp_table_entry { 171 /* the column sub-oid, ignored for index fields */ 172 asn_subid_t subid; 173 /* the syntax of the column or index */ 174 enum snmp_syntax syntax; 175 /* offset of the field into the C-structure. For octet strings 176 * this points to an u_char * followed by a size_t */ 177 off_t offset; 178 #if defined(__GNUC__) && __GNUC__ < 3 179 } entries[0]; 180 #else 181 } entries[]; 182 #endif 183 }; 184 185 /* callback type for table fetch */ 186 typedef void (*snmp_table_cb_f)(void *_list, void *_arg, int _res); 187 188 /* fetch a table. The argument points to a TAILQ_HEAD */ 189 int snmp_table_fetch(const struct snmp_table *descr, void *); 190 int snmp_table_fetch_async(const struct snmp_table *, void *, 191 snmp_table_cb_f, void *); 192 193 /* send a request and wait for the response */ 194 int snmp_dialog(struct snmp_pdu *_req, struct snmp_pdu *_resp); 195 196 /* discover an authorative snmpEngineId */ 197 int snmp_discover_engine(char *); 198 199 /* parse a server specification */ 200 int snmp_parse_server(struct snmp_client *, const char *); 201 202 #endif /* _BSNMP_SNMPCLIENT_H */ 203