1 /*-
2 * Copyright (c) 2005-2006 The FreeBSD Project
3 * All rights reserved.
4 *
5 * Author: Victor Cruceru <soc-victor@freebsd.org>
6 *
7 * Redistribution of this software and documentation and use in source and
8 * binary forms, with or without modification, are permitted provided that
9 * the following conditions are met:
10 *
11 * 1. Redistributions of source code or documentation must retain the above
12 * copyright 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 THE 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 THE 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
30 /*
31 * Host Resources MIB implementation for SNMPd: instrumentation for
32 * hrNetworkTable
33 */
34
35 #include <sys/types.h>
36 #include <sys/ioctl.h>
37 #include <sys/socket.h>
38 #include <sys/sysctl.h>
39
40 #include <net/if.h>
41 #include <net/if_mib.h>
42
43 #include <assert.h>
44 #include <ctype.h>
45 #include <err.h>
46 #include <errno.h>
47 #include <ifaddrs.h>
48 #include <stdarg.h>
49 #include <stdlib.h>
50 #include <string.h>
51 #include <syslog.h>
52 #include <unistd.h>
53
54 #include "hostres_snmp.h"
55 #include "hostres_oid.h"
56 #include "hostres_tree.h"
57
58 #include <bsnmp/snmp_mibII.h>
59
60 /*
61 * This structure is used to hold a SNMP table entry
62 * for HOST-RESOURCES-MIB's hrNetworkTable
63 */
64 struct network_entry {
65 int32_t index;
66 int32_t ifIndex;
67 TAILQ_ENTRY(network_entry) link;
68 #define HR_NETWORK_FOUND 0x001
69 uint32_t flags;
70
71 };
72 TAILQ_HEAD(network_tbl, network_entry);
73
74 /* the head of the list with hrNetworkTable's entries */
75 static struct network_tbl network_tbl = TAILQ_HEAD_INITIALIZER(network_tbl);
76
77 /* last (agent) tick when hrNetworkTable was updated */
78 static uint64_t network_tick;
79
80 /* maximum number of ticks between updates of network table */
81 uint32_t network_tbl_refresh = HR_NETWORK_TBL_REFRESH * 100;
82
83 /* Constants */
84 static const struct asn_oid OIDX_hrDeviceNetwork_c = OIDX_hrDeviceNetwork;
85
86 /**
87 * Create a new entry into the network table
88 */
89 static struct network_entry *
network_entry_create(const struct device_entry * devEntry)90 network_entry_create(const struct device_entry *devEntry)
91 {
92 struct network_entry *entry;
93
94 assert(devEntry != NULL);
95 if (devEntry == NULL)
96 return (NULL);
97
98 if ((entry = malloc(sizeof(*entry))) == NULL) {
99 syslog(LOG_WARNING, "%s: %m", __func__);
100 return (NULL);
101 }
102
103 memset(entry, 0, sizeof(*entry));
104 entry->index = devEntry->index;
105 INSERT_OBJECT_INT(entry, &network_tbl);
106
107 return (entry);
108 }
109
110 /**
111 * Delete an entry in the network table
112 */
113 static void
network_entry_delete(struct network_entry * entry)114 network_entry_delete(struct network_entry* entry)
115 {
116
117 TAILQ_REMOVE(&network_tbl, entry, link);
118 free(entry);
119 }
120
121 /**
122 * Fetch the interfaces from the mibII module, get their real name from the
123 * kernel and try to find it in the device table.
124 */
125 static void
network_get_interfaces(void)126 network_get_interfaces(void)
127 {
128 struct device_entry *dev;
129 struct network_entry *net;
130 struct mibif *ifp;
131 int name[6];
132 size_t len;
133 char *dname;
134
135 name[0] = CTL_NET;
136 name[1] = PF_LINK;
137 name[2] = NETLINK_GENERIC;
138 name[3] = IFMIB_IFDATA;
139 name[5] = IFDATA_DRIVERNAME;
140
141 for (ifp = mib_first_if(); ifp != NULL; ifp = mib_next_if(ifp)) {
142 HRDBG("%s %s", ifp->name, ifp->descr);
143
144 name[4] = ifp->sysindex;
145
146 /* get the original name */
147 len = 0;
148 if (sysctl(name, 6, NULL, &len, 0, 0) < 0) {
149 syslog(LOG_ERR, "sysctl(net.link.ifdata.%d."
150 "drivername): %m", ifp->sysindex);
151 continue;
152 }
153 if ((dname = malloc(len)) == NULL) {
154 syslog(LOG_ERR, "malloc: %m");
155 continue;
156 }
157 if (sysctl(name, 6, dname, &len, 0, 0) < 0) {
158 syslog(LOG_ERR, "sysctl(net.link.ifdata.%d."
159 "drivername): %m", ifp->sysindex);
160 free(dname);
161 continue;
162 }
163
164 HRDBG("got device %s (%s)", ifp->name, dname);
165
166 if ((dev = device_find_by_name(dname)) == NULL) {
167 HRDBG("%s not in hrDeviceTable", dname);
168 free(dname);
169 continue;
170 }
171 HRDBG("%s found in hrDeviceTable", dname);
172
173 dev->type = &OIDX_hrDeviceNetwork_c;
174 dev->flags |= HR_DEVICE_IMMUTABLE;
175
176 free(dname);
177
178 /* Then check hrNetworkTable for this device */
179 TAILQ_FOREACH(net, &network_tbl, link)
180 if (net->index == dev->index)
181 break;
182
183 if (net == NULL && (net = network_entry_create(dev)) == NULL)
184 continue;
185
186 net->flags |= HR_NETWORK_FOUND;
187 net->ifIndex = ifp->index;
188 }
189
190 network_tick = this_tick;
191 }
192
193 /**
194 * Finalization routine for hrNetworkTable.
195 * It destroys the lists and frees any allocated heap memory.
196 */
197 void
fini_network_tbl(void)198 fini_network_tbl(void)
199 {
200 struct network_entry *n1;
201
202 while ((n1 = TAILQ_FIRST(&network_tbl)) != NULL) {
203 TAILQ_REMOVE(&network_tbl, n1, link);
204 free(n1);
205 }
206 }
207
208 /**
209 * Get the interface list from mibII only at this point to be sure that
210 * it is there already.
211 */
212 void
start_network_tbl(void)213 start_network_tbl(void)
214 {
215
216 mib_refresh_iflist();
217 network_get_interfaces();
218 }
219
220 /**
221 * Refresh the table.
222 */
223 static void
refresh_network_tbl(void)224 refresh_network_tbl(void)
225 {
226 struct network_entry *entry, *entry_tmp;
227
228 if (this_tick - network_tick < network_tbl_refresh) {
229 HRDBG("no refresh needed");
230 return;
231 }
232
233 /* mark each entry as missing */
234 TAILQ_FOREACH(entry, &network_tbl, link)
235 entry->flags &= ~HR_NETWORK_FOUND;
236
237 network_get_interfaces();
238
239 /*
240 * Purge items that disappeared
241 */
242 TAILQ_FOREACH_SAFE(entry, &network_tbl, link, entry_tmp) {
243 if (!(entry->flags & HR_NETWORK_FOUND))
244 network_entry_delete(entry);
245 }
246
247 HRDBG("refresh DONE");
248 }
249
250 /*
251 * This is the implementation for a generated (by our SNMP tool)
252 * function prototype, see hostres_tree.h
253 * It handles the SNMP operations for hrNetworkTable
254 */
255 int
op_hrNetworkTable(struct snmp_context * ctx __unused,struct snmp_value * value,u_int sub,u_int iidx __unused,enum snmp_op curr_op)256 op_hrNetworkTable(struct snmp_context *ctx __unused, struct snmp_value *value,
257 u_int sub, u_int iidx __unused, enum snmp_op curr_op)
258 {
259 struct network_entry *entry;
260
261 refresh_network_tbl();
262
263 switch (curr_op) {
264
265 case SNMP_OP_GETNEXT:
266 if ((entry = NEXT_OBJECT_INT(&network_tbl,
267 &value->var, sub)) == NULL)
268 return (SNMP_ERR_NOSUCHNAME);
269 value->var.len = sub + 1;
270 value->var.subs[sub] = entry->index;
271 goto get;
272
273 case SNMP_OP_GET:
274 if ((entry = FIND_OBJECT_INT(&network_tbl,
275 &value->var, sub)) == NULL)
276 return (SNMP_ERR_NOSUCHNAME);
277 goto get;
278
279 case SNMP_OP_SET:
280 if ((entry = FIND_OBJECT_INT(&network_tbl,
281 &value->var, sub)) == NULL)
282 return (SNMP_ERR_NO_CREATION);
283 return (SNMP_ERR_NOT_WRITEABLE);
284
285 case SNMP_OP_ROLLBACK:
286 case SNMP_OP_COMMIT:
287 abort();
288 }
289 abort();
290
291 get:
292 switch (value->var.subs[sub - 1]) {
293
294 case LEAF_hrNetworkIfIndex:
295 value->v.integer = entry->ifIndex;
296 return (SNMP_ERR_NOERROR);
297
298 }
299 abort();
300 }
301