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() */
57typedef void (*snmp_send_cb_f)(struct snmp_pdu *, struct snmp_pdu *, void *);
58
59/* type of callback function for timeouts */
60typedef void (*snmp_timeout_cb_f)(void * );
61
62/* timeout start function */
63typedef void *(*snmp_timeout_start_f)(struct timeval *timeout,
64    snmp_timeout_cb_f callback, void *);
65
66/* timeout stop function */
67typedef void (*snmp_timeout_stop_f)(void *timeout_id);
68
69/*
70 * Client context.
71 */
72struct 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 */
117extern struct snmp_client snmp_client;
118
119/* initizialies a snmp_client structure */
120void snmp_client_init(struct snmp_client *);
121
122/* initialize fields */
123int snmp_client_set_host(struct snmp_client *, const char *);
124int snmp_client_set_port(struct snmp_client *, const char *);
125
126/* open connection to snmp server (hostname or portname can be NULL) */
127int snmp_open(const char *_hostname, const char *_portname,
128    const char *_read_community, const char *_write_community);
129
130/* close connection */
131void snmp_close(void);
132
133/* initialize a snmp_pdu structure */
134void snmp_pdu_create(struct snmp_pdu *, u_int _op);
135
136/* add pairs of (struct asn_oid *, enum snmp_syntax) to an existing pdu */
137int snmp_add_binding(struct snmp_pdu *, ...);
138
139/* check wheater the answer is valid or not */
140int snmp_pdu_check(const struct snmp_pdu *_req, const struct snmp_pdu *_resp);
141
142int32_t snmp_pdu_send(struct snmp_pdu *_pdu, snmp_send_cb_f _func, void *_arg);
143
144/*  append an index to an oid */
145int snmp_oid_append(struct asn_oid *_oid, const char *_fmt, ...);
146
147/* receive a packet */
148int 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 */
155struct 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 */
186typedef void (*snmp_table_cb_f)(void *_list, void *_arg, int _res);
187
188/* fetch a table. The argument points to a TAILQ_HEAD */
189int snmp_table_fetch(const struct snmp_table *descr, void *);
190int 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 */
194int snmp_dialog(struct snmp_pdu *_req, struct snmp_pdu *_resp);
195
196/* discover an authorative snmpEngineId */
197int snmp_discover_engine(char *);
198
199/* parse a server specification */
200int snmp_parse_server(struct snmp_client *, const char *);
201
202#endif /* _BSNMP_SNMPCLIENT_H */
203