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 53 /* type of callback function for responses 54 * this callback function is responsible for free() any memory associated with 55 * any of the PDUs. Therefor it may call snmp_pdu_free() */ 56 typedef void (*snmp_send_cb_f)(struct snmp_pdu *, struct snmp_pdu *, void *); 57 58 /* type of callback function for timeouts */ 59 typedef void (*snmp_timeout_cb_f)(void * ); 60 61 /* timeout start function */ 62 typedef void *(*snmp_timeout_start_f)(struct timeval *timeout, 63 snmp_timeout_cb_f callback, void *); 64 65 /* timeout stop function */ 66 typedef void (*snmp_timeout_stop_f)(void *timeout_id); 67 68 /* 69 * Client context. 70 */ 71 struct snmp_client { 72 enum snmp_version version; 73 int trans; /* which transport to use */ 74 75 /* these two are read-only for the application */ 76 char *cport; /* port number as string */ 77 char *chost; /* host name or IP address as string */ 78 79 char read_community[SNMP_COMMUNITY_MAXLEN + 1]; 80 char write_community[SNMP_COMMUNITY_MAXLEN + 1]; 81 82 struct timeval timeout; 83 u_int retries; 84 85 int dump_pdus; 86 87 size_t txbuflen; 88 size_t rxbuflen; 89 90 int fd; 91 92 int32_t next_reqid; 93 int32_t max_reqid; 94 int32_t min_reqid; 95 96 char error[SNMP_STRERROR_LEN]; 97 98 snmp_timeout_start_f timeout_start; 99 snmp_timeout_stop_f timeout_stop; 100 101 char local_path[sizeof(SNMP_LOCAL_PATH)]; 102 }; 103 104 /* the global context */ 105 extern struct snmp_client snmp_client; 106 107 /* initizialies a snmp_client structure */ 108 void snmp_client_init(struct snmp_client *); 109 110 /* initialize fields */ 111 int snmp_client_set_host(struct snmp_client *, const char *); 112 int snmp_client_set_port(struct snmp_client *, const char *); 113 114 /* open connection to snmp server (hostname or portname can be NULL) */ 115 int snmp_open(const char *_hostname, const char *_portname, 116 const char *_read_community, const char *_write_community); 117 118 /* close connection */ 119 void snmp_close(void); 120 121 /* initialize a snmp_pdu structure */ 122 void snmp_pdu_create(struct snmp_pdu *, u_int _op); 123 124 /* add pairs of (struct asn_oid *, enum snmp_syntax) to an existing pdu */ 125 int snmp_add_binding(struct snmp_pdu *, ...); 126 127 /* check wheater the answer is valid or not */ 128 int snmp_pdu_check(const struct snmp_pdu *_req, const struct snmp_pdu *_resp); 129 130 int32_t snmp_pdu_send(struct snmp_pdu *_pdu, snmp_send_cb_f _func, void *_arg); 131 132 /* append an index to an oid */ 133 int snmp_oid_append(struct asn_oid *_oid, const char *_fmt, ...); 134 135 /* receive a packet */ 136 int snmp_receive(int _blocking); 137 138 /* 139 * This structure is used to describe an SNMP table that is to be fetched. 140 * The C-structure that is produced by the fetch function must start with 141 * a TAILQ_ENTRY and an u_int64_t. 142 */ 143 struct snmp_table { 144 /* base OID of the table */ 145 struct asn_oid table; 146 /* type OID of the LastChange variable for the table if any */ 147 struct asn_oid last_change; 148 /* maximum number of iterations if table has changed */ 149 u_int max_iter; 150 /* size of the C-structure */ 151 size_t entry_size; 152 /* number of index fields */ 153 u_int index_size; 154 /* bit mask of required fields */ 155 uint64_t req_mask; 156 157 /* indexes and columns to fetch. Ended by a NULL syntax entry */ 158 struct snmp_table_entry { 159 /* the column sub-oid, ignored for index fields */ 160 asn_subid_t subid; 161 /* the syntax of the column or index */ 162 enum snmp_syntax syntax; 163 /* offset of the field into the C-structure. For octet strings 164 * this points to an u_char * followed by a size_t */ 165 off_t offset; 166 #if defined(__GNUC__) && __GNUC__ < 3 167 } entries[0]; 168 #else 169 } entries[]; 170 #endif 171 }; 172 173 /* callback type for table fetch */ 174 typedef void (*snmp_table_cb_f)(void *_list, void *_arg, int _res); 175 176 /* fetch a table. The argument points to a TAILQ_HEAD */ 177 int snmp_table_fetch(const struct snmp_table *descr, void *); 178 int snmp_table_fetch_async(const struct snmp_table *, void *, 179 snmp_table_cb_f, void *); 180 181 /* send a request and wait for the response */ 182 int snmp_dialog(struct snmp_pdu *_req, struct snmp_pdu *_resp); 183 184 /* parse a server specification */ 185 int snmp_parse_server(struct snmp_client *, const char *); 186 187 #endif /* _BSNMP_SNMPCLIENT_H */ 188