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 * 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 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 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 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 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 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 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