1/*
2 * Copyright (c) 2003
3 * Fraunhofer Institute for Open Communication Systems (FhG Fokus).
4 * All rights reserved.
5 *
6 * Author: Harti Brandt <harti@freebsd.org>
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 *
17 * THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 *
29 * $Begemot: bsnmp/snmpd/trans_udp.c,v 1.4 2004/08/06 08:47:16 brandt Exp $
30 *
31 * UDP transport
32 */
33#include <sys/types.h>
34
35#include <stdlib.h>
36#include <syslog.h>
37#include <string.h>
38#include <errno.h>
39#include <unistd.h>
40
41#include <netinet/in.h>
42#include <arpa/inet.h>
43
44#include "snmpmod.h"
45#include "snmpd.h"
46#include "trans_udp.h"
47#include "tree.h"
48#include "oid.h"
49
50static int udp_start(void);
51static int udp_stop(int);
52static void udp_close_port(struct tport *);
53static int udp_init_port(struct tport *);
54static ssize_t udp_send(struct tport *, const u_char *, size_t,
55 const struct sockaddr *, size_t);
56
57/* exported */
58const struct transport_def udp_trans = {
59 "udp",
60 OIDX_begemotSnmpdTransUdp,
61 udp_start,
62 udp_stop,
63 udp_close_port,
64 udp_init_port,
65 udp_send
66};
67static struct transport *my_trans;
68
69static int
70udp_start(void)
71{
72 return (trans_register(&udp_trans, &my_trans));
73}
74
75static int
76udp_stop(int force __unused)
77{
78 if (my_trans != NULL)
79 if (trans_unregister(my_trans) != 0)
80 return (SNMP_ERR_GENERR);
81 return (SNMP_ERR_NOERROR);
82}
83
84/*
85 * A UDP port is ready
86 */
87static void
88udp_input(int fd __unused, void *udata)
89{
90 struct udp_port *p = udata;
91
92 p->input.peerlen = sizeof(p->ret);
93 snmpd_input(&p->input, &p->tport);
94}
95
96/*
97 * Create a UDP socket and bind it to the given port
98 */
99static int
100udp_init_port(struct tport *tp)
101{
102 struct udp_port *p = (struct udp_port *)tp;
103 struct sockaddr_in addr;
104 u_int32_t ip;
105
106 if ((p->input.fd = socket(PF_INET, SOCK_DGRAM, 0)) < 0) {
107 syslog(LOG_ERR, "creating UDP socket: %m");
108 return (SNMP_ERR_RES_UNAVAIL);
109 }
110 ip = (p->addr[0] << 24) | (p->addr[1] << 16) | (p->addr[2] << 8) |
111 p->addr[3];
112 memset(&addr, 0, sizeof(addr));
113 addr.sin_addr.s_addr = htonl(ip);
114 addr.sin_port = htons(p->port);
115 addr.sin_family = AF_INET;
116 addr.sin_len = sizeof(addr);
117 if (bind(p->input.fd, (struct sockaddr *)&addr, sizeof(addr))) {
118 if (errno == EADDRNOTAVAIL) {
119 close(p->input.fd);
120 p->input.fd = -1;
121 return (SNMP_ERR_INCONS_NAME);
122 }
123 syslog(LOG_ERR, "bind: %s:%u %m", inet_ntoa(addr.sin_addr),
124 p->port);
125 close(p->input.fd);
126 p->input.fd = -1;
127 return (SNMP_ERR_GENERR);
128 }
129 if ((p->input.id = fd_select(p->input.fd, udp_input,
130 p, NULL)) == NULL) {
131 close(p->input.fd);
132 p->input.fd = -1;
133 return (SNMP_ERR_GENERR);
134 }
135 return (SNMP_ERR_NOERROR);
136}
137
138/*
139 * Create a new SNMP Port object and start it, if we are not
140 * in initialisation mode. The arguments are in host byte order.
141 */
142static int
143udp_open_port(u_int8_t *addr, u_int32_t udp_port, struct udp_port **pp)
144{
145 struct udp_port *port;
146 int err;
147
148 if (udp_port > 0xffff)
149 return (SNMP_ERR_NO_CREATION);
150 if ((port = malloc(sizeof(*port))) == NULL)
151 return (SNMP_ERR_GENERR);
152 memset(port, 0, sizeof(*port));
153
154 /* initialize common part */
155 port->tport.index.len = 5;
156 port->tport.index.subs[0] = addr[0];
157 port->tport.index.subs[1] = addr[1];
158 port->tport.index.subs[2] = addr[2];
159 port->tport.index.subs[3] = addr[3];
160 port->tport.index.subs[4] = udp_port;
161
162 port->addr[0] = addr[0];
163 port->addr[1] = addr[1];
164 port->addr[2] = addr[2];
165 port->addr[3] = addr[3];
166 port->port = udp_port;
167
168 port->input.fd = -1;
169 port->input.id = NULL;
170 port->input.stream = 0;
171 port->input.cred = 0;
172 port->input.peer = (struct sockaddr *)&port->ret;
173 port->input.peerlen = sizeof(port->ret);
174
175 trans_insert_port(my_trans, &port->tport);
176
177 if (community != COMM_INITIALIZE &&
178 (err = udp_init_port(&port->tport)) != SNMP_ERR_NOERROR) {
179 udp_close_port(&port->tport);
180 return (err);
181 }
182 *pp = port;
183 return (SNMP_ERR_NOERROR);
184}
185
186/*
187 * Close an SNMP port
188 */
189static void
190udp_close_port(struct tport *tp)
191{
192 struct udp_port *port = (struct udp_port *)tp;
193
194 snmpd_input_close(&port->input);
195 trans_remove_port(tp);
196 free(port);
197}
198
199/*
200 * Send something
201 */
202static ssize_t
203udp_send(struct tport *tp, const u_char *buf, size_t len,
204 const struct sockaddr *addr, size_t addrlen)
205{
206 struct udp_port *p = (struct udp_port *)tp;
207
208 return (sendto(p->input.fd, buf, len, 0, addr, addrlen));
209}
210
211/*
212 * Port table
213 */
214int
215op_snmp_port(struct snmp_context *ctx, struct snmp_value *value,
216 u_int sub, u_int iidx, enum snmp_op op)
217{
218 asn_subid_t which = value->var.subs[sub-1];
219 struct udp_port *p;
220 u_int8_t addr[4];
221 u_int32_t port;
222
223 switch (op) {
224
225 case SNMP_OP_GETNEXT:
226 if ((p = (struct udp_port *)trans_next_port(my_trans,
227 &value->var, sub)) == NULL)
228 return (SNMP_ERR_NOSUCHNAME);
229 index_append(&value->var, sub, &p->tport.index);
230 break;
231
232 case SNMP_OP_GET:
233 if ((p = (struct udp_port *)trans_find_port(my_trans,
234 &value->var, sub)) == NULL)
235 return (SNMP_ERR_NOSUCHNAME);
236 break;
237
238 case SNMP_OP_SET:
239 p = (struct udp_port *)trans_find_port(my_trans,
240 &value->var, sub);
241 ctx->scratch->int1 = (p != NULL);
242
243 if (which != LEAF_begemotSnmpdPortStatus)
244 abort();
245 if (!TRUTH_OK(value->v.integer))
246 return (SNMP_ERR_WRONG_VALUE);
247
248 ctx->scratch->int2 = TRUTH_GET(value->v.integer);
249
250 if (ctx->scratch->int2) {
251 /* open an SNMP port */
252 if (p != NULL)
253 /* already open - do nothing */
254 return (SNMP_ERR_NOERROR);
255
256 if (index_decode(&value->var, sub, iidx, addr, &port))
257 return (SNMP_ERR_NO_CREATION);
258 return (udp_open_port(addr, port, &p));
259
260 } else {
261 /* close SNMP port - do in commit */
262 }
263 return (SNMP_ERR_NOERROR);
264
265 case SNMP_OP_ROLLBACK:
266 p = (struct udp_port *)trans_find_port(my_trans,
267 &value->var, sub);
268 if (ctx->scratch->int1 == 0) {
269 /* did not exist */
270 if (ctx->scratch->int2 == 1) {
271 /* created */
272 if (p != NULL)
273 udp_close_port(&p->tport);
274 }
275 }
276 return (SNMP_ERR_NOERROR);
277
278 case SNMP_OP_COMMIT:
279 p = (struct udp_port *)trans_find_port(my_trans,
280 &value->var, sub);
281 if (ctx->scratch->int1 == 1) {
282 /* did exist */
283 if (ctx->scratch->int2 == 0) {
284 /* delete */
285 if (p != NULL)
286 udp_close_port(&p->tport);
287 }
288 }
289 return (SNMP_ERR_NOERROR);
290
291 default:
292 abort();
293 }
294
295 /*
296 * Come here to fetch the value
297 */
298 switch (which) {
299
300 case LEAF_begemotSnmpdPortStatus:
301 value->v.integer = 1;
302 break;
303
304 default:
305 abort();
306 }
307
308 return (SNMP_ERR_NOERROR);
309}