1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21 
  22 /*
  23  * Copyright (c) 2010, Oracle and/or its affiliates. All rights reserved.
  24  */
  25 
  26 #include <sys/types.h>
  27 #include <sys/tihdr.h>
  28 #include <sys/policy.h>
  29 #include <sys/tsol/tnet.h>
  30 
  31 #include <inet/common.h>
  32 #include <inet/kstatcom.h>
  33 #include <inet/snmpcom.h>
  34 #include <inet/mib2.h>
  35 #include <inet/optcom.h>
  36 #include <inet/snmpcom.h>
  37 #include <inet/kstatcom.h>
  38 #include <inet/udp_impl.h>
  39 
  40 static int      udp_kstat_update(kstat_t *, int);
  41 static int      udp_kstat2_update(kstat_t *, int);
  42 static void     udp_sum_mib(udp_stack_t *, mib2_udp_t *);
  43 static void     udp_clr_stats(udp_stat_t *);
  44 static void     udp_add_stats(udp_stat_counter_t *, udp_stat_t *);
  45 static void     udp_add_mib(mib2_udp_t *, mib2_udp_t *);
  46 /*
  47  * return SNMP stuff in buffer in mpdata. We don't hold any lock and report
  48  * information that can be changing beneath us.
  49  */
  50 mblk_t *
  51 udp_snmp_get(queue_t *q, mblk_t *mpctl, boolean_t legacy_req)
  52 {
  53         mblk_t                  *mpdata;
  54         mblk_t                  *mp_conn_ctl;
  55         mblk_t                  *mp_attr_ctl;
  56         mblk_t                  *mp6_conn_ctl;
  57         mblk_t                  *mp6_attr_ctl;
  58         mblk_t                  *mp_conn_tail;
  59         mblk_t                  *mp_attr_tail;
  60         mblk_t                  *mp6_conn_tail;
  61         mblk_t                  *mp6_attr_tail;
  62         struct opthdr           *optp;
  63         mib2_udpEntry_t         ude;
  64         mib2_udp6Entry_t        ude6;
  65         mib2_transportMLPEntry_t mlp;
  66         int                     state;
  67         zoneid_t                zoneid;
  68         int                     i;
  69         connf_t                 *connfp;
  70         conn_t                  *connp = Q_TO_CONN(q);
  71         int                     v4_conn_idx;
  72         int                     v6_conn_idx;
  73         boolean_t               needattr;
  74         udp_t                   *udp;
  75         ip_stack_t              *ipst = connp->conn_netstack->netstack_ip;
  76         udp_stack_t             *us = connp->conn_netstack->netstack_udp;
  77         mblk_t                  *mp2ctl;
  78         mib2_udp_t              udp_mib;
  79         size_t                  udp_mib_size, ude_size, ude6_size;
  80 
  81 
  82         /*
  83          * make a copy of the original message
  84          */
  85         mp2ctl = copymsg(mpctl);
  86 
  87         mp_conn_ctl = mp_attr_ctl = mp6_conn_ctl = NULL;
  88         if (mpctl == NULL ||
  89             (mpdata = mpctl->b_cont) == NULL ||
  90             (mp_conn_ctl = copymsg(mpctl)) == NULL ||
  91             (mp_attr_ctl = copymsg(mpctl)) == NULL ||
  92             (mp6_conn_ctl = copymsg(mpctl)) == NULL ||
  93             (mp6_attr_ctl = copymsg(mpctl)) == NULL) {
  94                 freemsg(mp_conn_ctl);
  95                 freemsg(mp_attr_ctl);
  96                 freemsg(mp6_conn_ctl);
  97                 freemsg(mpctl);
  98                 freemsg(mp2ctl);
  99                 return (0);
 100         }
 101 
 102         zoneid = connp->conn_zoneid;
 103 
 104         if (legacy_req) {
 105                 udp_mib_size = LEGACY_MIB_SIZE(&udp_mib, mib2_udp_t);
 106                 ude_size = LEGACY_MIB_SIZE(&ude, mib2_udpEntry_t);
 107                 ude6_size = LEGACY_MIB_SIZE(&ude6, mib2_udp6Entry_t);
 108         } else {
 109                 udp_mib_size = sizeof (mib2_udp_t);
 110                 ude_size = sizeof (mib2_udpEntry_t);
 111                 ude6_size = sizeof (mib2_udp6Entry_t);
 112         }
 113 
 114         bzero(&udp_mib, sizeof (udp_mib));
 115         /* fixed length structure for IPv4 and IPv6 counters */
 116         SET_MIB(udp_mib.udpEntrySize, ude_size);
 117         SET_MIB(udp_mib.udp6EntrySize, ude6_size);
 118 
 119         udp_sum_mib(us, &udp_mib);
 120 
 121         /*
 122          * Synchronize 32- and 64-bit counters.  Note that udpInDatagrams and
 123          * udpOutDatagrams are not updated anywhere in UDP.  The new 64 bits
 124          * counters are used.  Hence the old counters' values in us_sc_mib
 125          * are always 0.
 126          */
 127         SYNC32_MIB(&udp_mib, udpInDatagrams, udpHCInDatagrams);
 128         SYNC32_MIB(&udp_mib, udpOutDatagrams, udpHCOutDatagrams);
 129 
 130         optp = (struct opthdr *)&mpctl->b_rptr[sizeof (struct T_optmgmt_ack)];
 131         optp->level = MIB2_UDP;
 132         optp->name = 0;
 133         (void) snmp_append_data(mpdata, (char *)&udp_mib, udp_mib_size);
 134         optp->len = msgdsize(mpdata);
 135         qreply(q, mpctl);
 136 
 137         mp_conn_tail = mp_attr_tail = mp6_conn_tail = mp6_attr_tail = NULL;
 138         v4_conn_idx = v6_conn_idx = 0;
 139 
 140         for (i = 0; i < CONN_G_HASH_SIZE; i++) {
 141                 connfp = &ipst->ips_ipcl_globalhash_fanout[i];
 142                 connp = NULL;
 143 
 144                 while ((connp = ipcl_get_next_conn(connfp, connp,
 145                     IPCL_UDPCONN))) {
 146                         udp = connp->conn_udp;
 147                         if (zoneid != connp->conn_zoneid)
 148                                 continue;
 149 
 150                         /*
 151                          * Note that the port numbers are sent in
 152                          * host byte order
 153                          */
 154 
 155                         if (udp->udp_state == TS_UNBND)
 156                                 state = MIB2_UDP_unbound;
 157                         else if (udp->udp_state == TS_IDLE)
 158                                 state = MIB2_UDP_idle;
 159                         else if (udp->udp_state == TS_DATA_XFER)
 160                                 state = MIB2_UDP_connected;
 161                         else
 162                                 state = MIB2_UDP_unknown;
 163 
 164                         needattr = B_FALSE;
 165                         bzero(&mlp, sizeof (mlp));
 166                         if (connp->conn_mlp_type != mlptSingle) {
 167                                 if (connp->conn_mlp_type == mlptShared ||
 168                                     connp->conn_mlp_type == mlptBoth)
 169                                         mlp.tme_flags |= MIB2_TMEF_SHARED;
 170                                 if (connp->conn_mlp_type == mlptPrivate ||
 171                                     connp->conn_mlp_type == mlptBoth)
 172                                         mlp.tme_flags |= MIB2_TMEF_PRIVATE;
 173                                 needattr = B_TRUE;
 174                         }
 175                         if (connp->conn_anon_mlp) {
 176                                 mlp.tme_flags |= MIB2_TMEF_ANONMLP;
 177                                 needattr = B_TRUE;
 178                         }
 179                         switch (connp->conn_mac_mode) {
 180                         case CONN_MAC_DEFAULT:
 181                                 break;
 182                         case CONN_MAC_AWARE:
 183                                 mlp.tme_flags |= MIB2_TMEF_MACEXEMPT;
 184                                 needattr = B_TRUE;
 185                                 break;
 186                         case CONN_MAC_IMPLICIT:
 187                                 mlp.tme_flags |= MIB2_TMEF_MACIMPLICIT;
 188                                 needattr = B_TRUE;
 189                                 break;
 190                         }
 191                         mutex_enter(&connp->conn_lock);
 192                         if (udp->udp_state == TS_DATA_XFER &&
 193                             connp->conn_ixa->ixa_tsl != NULL) {
 194                                 ts_label_t *tsl;
 195 
 196                                 tsl = connp->conn_ixa->ixa_tsl;
 197                                 mlp.tme_flags |= MIB2_TMEF_IS_LABELED;
 198                                 mlp.tme_doi = label2doi(tsl);
 199                                 mlp.tme_label = *label2bslabel(tsl);
 200                                 needattr = B_TRUE;
 201                         }
 202                         mutex_exit(&connp->conn_lock);
 203 
 204                         /*
 205                          * Create an IPv4 table entry for IPv4 entries and also
 206                          * any IPv6 entries which are bound to in6addr_any
 207                          * (i.e. anything a IPv4 peer could connect/send to).
 208                          */
 209                         if (connp->conn_ipversion == IPV4_VERSION ||
 210                             (udp->udp_state <= TS_IDLE &&
 211                             IN6_IS_ADDR_UNSPECIFIED(&connp->conn_laddr_v6))) {
 212                                 ude.udpEntryInfo.ue_state = state;
 213                                 /*
 214                                  * If in6addr_any this will set it to
 215                                  * INADDR_ANY
 216                                  */
 217                                 ude.udpLocalAddress = connp->conn_laddr_v4;
 218                                 ude.udpLocalPort = ntohs(connp->conn_lport);
 219                                 if (udp->udp_state == TS_DATA_XFER) {
 220                                         /*
 221                                          * Can potentially get here for
 222                                          * v6 socket if another process
 223                                          * (say, ping) has just done a
 224                                          * sendto(), changing the state
 225                                          * from the TS_IDLE above to
 226                                          * TS_DATA_XFER by the time we hit
 227                                          * this part of the code.
 228                                          */
 229                                         ude.udpEntryInfo.ue_RemoteAddress =
 230                                             connp->conn_faddr_v4;
 231                                         ude.udpEntryInfo.ue_RemotePort =
 232                                             ntohs(connp->conn_fport);
 233                                 } else {
 234                                         ude.udpEntryInfo.ue_RemoteAddress = 0;
 235                                         ude.udpEntryInfo.ue_RemotePort = 0;
 236                                 }
 237 
 238                                 /*
 239                                  * We make the assumption that all udp_t
 240                                  * structs will be created within an address
 241                                  * region no larger than 32-bits.
 242                                  */
 243                                 ude.udpInstance = (uint32_t)(uintptr_t)udp;
 244                                 ude.udpCreationProcess =
 245                                     (connp->conn_cpid < 0) ?
 246                                     MIB2_UNKNOWN_PROCESS :
 247                                     connp->conn_cpid;
 248                                 ude.udpCreationTime = connp->conn_open_time;
 249 
 250                                 (void) snmp_append_data2(mp_conn_ctl->b_cont,
 251                                     &mp_conn_tail, (char *)&ude, ude_size);
 252                                 mlp.tme_connidx = v4_conn_idx++;
 253                                 if (needattr)
 254                                         (void) snmp_append_data2(
 255                                             mp_attr_ctl->b_cont, &mp_attr_tail,
 256                                             (char *)&mlp, sizeof (mlp));
 257                         }
 258                         if (connp->conn_ipversion == IPV6_VERSION) {
 259                                 ude6.udp6EntryInfo.ue_state  = state;
 260                                 ude6.udp6LocalAddress = connp->conn_laddr_v6;
 261                                 ude6.udp6LocalPort = ntohs(connp->conn_lport);
 262                                 mutex_enter(&connp->conn_lock);
 263                                 if (connp->conn_ixa->ixa_flags &
 264                                     IXAF_SCOPEID_SET) {
 265                                         ude6.udp6IfIndex =
 266                                             connp->conn_ixa->ixa_scopeid;
 267                                 } else {
 268                                         ude6.udp6IfIndex = connp->conn_bound_if;
 269                                 }
 270                                 mutex_exit(&connp->conn_lock);
 271                                 if (udp->udp_state == TS_DATA_XFER) {
 272                                         ude6.udp6EntryInfo.ue_RemoteAddress =
 273                                             connp->conn_faddr_v6;
 274                                         ude6.udp6EntryInfo.ue_RemotePort =
 275                                             ntohs(connp->conn_fport);
 276                                 } else {
 277                                         ude6.udp6EntryInfo.ue_RemoteAddress =
 278                                             sin6_null.sin6_addr;
 279                                         ude6.udp6EntryInfo.ue_RemotePort = 0;
 280                                 }
 281                                 /*
 282                                  * We make the assumption that all udp_t
 283                                  * structs will be created within an address
 284                                  * region no larger than 32-bits.
 285                                  */
 286                                 ude6.udp6Instance = (uint32_t)(uintptr_t)udp;
 287                                 ude6.udp6CreationProcess =
 288                                     (connp->conn_cpid < 0) ?
 289                                     MIB2_UNKNOWN_PROCESS :
 290                                     connp->conn_cpid;
 291                                 ude6.udp6CreationTime = connp->conn_open_time;
 292 
 293                                 (void) snmp_append_data2(mp6_conn_ctl->b_cont,
 294                                     &mp6_conn_tail, (char *)&ude6, ude6_size);
 295                                 mlp.tme_connidx = v6_conn_idx++;
 296                                 if (needattr)
 297                                         (void) snmp_append_data2(
 298                                             mp6_attr_ctl->b_cont,
 299                                             &mp6_attr_tail, (char *)&mlp,
 300                                             sizeof (mlp));
 301                         }
 302                 }
 303         }
 304 
 305         /* IPv4 UDP endpoints */
 306         optp = (struct opthdr *)&mp_conn_ctl->b_rptr[
 307             sizeof (struct T_optmgmt_ack)];
 308         optp->level = MIB2_UDP;
 309         optp->name = MIB2_UDP_ENTRY;
 310         optp->len = msgdsize(mp_conn_ctl->b_cont);
 311         qreply(q, mp_conn_ctl);
 312 
 313         /* table of MLP attributes... */
 314         optp = (struct opthdr *)&mp_attr_ctl->b_rptr[
 315             sizeof (struct T_optmgmt_ack)];
 316         optp->level = MIB2_UDP;
 317         optp->name = EXPER_XPORT_MLP;
 318         optp->len = msgdsize(mp_attr_ctl->b_cont);
 319         if (optp->len == 0)
 320                 freemsg(mp_attr_ctl);
 321         else
 322                 qreply(q, mp_attr_ctl);
 323 
 324         /* IPv6 UDP endpoints */
 325         optp = (struct opthdr *)&mp6_conn_ctl->b_rptr[
 326             sizeof (struct T_optmgmt_ack)];
 327         optp->level = MIB2_UDP6;
 328         optp->name = MIB2_UDP6_ENTRY;
 329         optp->len = msgdsize(mp6_conn_ctl->b_cont);
 330         qreply(q, mp6_conn_ctl);
 331 
 332         /* table of MLP attributes... */
 333         optp = (struct opthdr *)&mp6_attr_ctl->b_rptr[
 334             sizeof (struct T_optmgmt_ack)];
 335         optp->level = MIB2_UDP6;
 336         optp->name = EXPER_XPORT_MLP;
 337         optp->len = msgdsize(mp6_attr_ctl->b_cont);
 338         if (optp->len == 0)
 339                 freemsg(mp6_attr_ctl);
 340         else
 341                 qreply(q, mp6_attr_ctl);
 342 
 343         return (mp2ctl);
 344 }
 345 
 346 /*
 347  * Return 0 if invalid set request, 1 otherwise, including non-udp requests.
 348  * NOTE: Per MIB-II, UDP has no writable data.
 349  * TODO:  If this ever actually tries to set anything, it needs to be
 350  * to do the appropriate locking.
 351  */
 352 /* ARGSUSED */
 353 int
 354 udp_snmp_set(queue_t *q, t_scalar_t level, t_scalar_t name,
 355     uchar_t *ptr, int len)
 356 {
 357         switch (level) {
 358         case MIB2_UDP:
 359                 return (0);
 360         default:
 361                 return (1);
 362         }
 363 }
 364 
 365 void
 366 udp_kstat_fini(netstackid_t stackid, kstat_t *ksp)
 367 {
 368         if (ksp != NULL) {
 369                 ASSERT(stackid == (netstackid_t)(uintptr_t)ksp->ks_private);
 370                 kstat_delete_netstack(ksp, stackid);
 371         }
 372 }
 373 
 374 /*
 375  * To add stats from one mib2_udp_t to another.  Static fields are not added.
 376  * The caller should set them up propertly.
 377  */
 378 static void
 379 udp_add_mib(mib2_udp_t *from, mib2_udp_t *to)
 380 {
 381         to->udpHCInDatagrams += from->udpHCInDatagrams;
 382         to->udpInErrors += from->udpInErrors;
 383         to->udpHCOutDatagrams += from->udpHCOutDatagrams;
 384         to->udpOutErrors += from->udpOutErrors;
 385 }
 386 
 387 
 388 void *
 389 udp_kstat2_init(netstackid_t stackid)
 390 {
 391         kstat_t *ksp;
 392 
 393         udp_stat_t template = {
 394                 { "udp_sock_fallback",          KSTAT_DATA_UINT64 },
 395                 { "udp_out_opt",                KSTAT_DATA_UINT64 },
 396                 { "udp_out_err_notconn",        KSTAT_DATA_UINT64 },
 397                 { "udp_out_err_output",         KSTAT_DATA_UINT64 },
 398                 { "udp_out_err_tudr",           KSTAT_DATA_UINT64 },
 399 #ifdef DEBUG
 400                 { "udp_data_conn",              KSTAT_DATA_UINT64 },
 401                 { "udp_data_notconn",           KSTAT_DATA_UINT64 },
 402                 { "udp_out_lastdst",            KSTAT_DATA_UINT64 },
 403                 { "udp_out_diffdst",            KSTAT_DATA_UINT64 },
 404                 { "udp_out_ipv6",               KSTAT_DATA_UINT64 },
 405                 { "udp_out_mapped",             KSTAT_DATA_UINT64 },
 406                 { "udp_out_ipv4",               KSTAT_DATA_UINT64 },
 407 #endif
 408         };
 409 
 410         ksp = kstat_create_netstack(UDP_MOD_NAME, 0, "udpstat", "net",
 411             KSTAT_TYPE_NAMED, sizeof (template) / sizeof (kstat_named_t),
 412             0, stackid);
 413 
 414         if (ksp == NULL)
 415                 return (NULL);
 416 
 417         bcopy(&template, ksp->ks_data, sizeof (template));
 418         ksp->ks_update = udp_kstat2_update;
 419         ksp->ks_private = (void *)(uintptr_t)stackid;
 420 
 421         kstat_install(ksp);
 422         return (ksp);
 423 }
 424 
 425 void
 426 udp_kstat2_fini(netstackid_t stackid, kstat_t *ksp)
 427 {
 428         if (ksp != NULL) {
 429                 ASSERT(stackid == (netstackid_t)(uintptr_t)ksp->ks_private);
 430                 kstat_delete_netstack(ksp, stackid);
 431         }
 432 }
 433 
 434 /*
 435  * To copy counters from the per CPU udpp_stat_counter_t to the stack
 436  * udp_stat_t.
 437  */
 438 static void
 439 udp_add_stats(udp_stat_counter_t *from, udp_stat_t *to)
 440 {
 441         to->udp_sock_fallback.value.ui64 += from->udp_sock_fallback;
 442         to->udp_out_opt.value.ui64 += from->udp_out_opt;
 443         to->udp_out_err_notconn.value.ui64 += from->udp_out_err_notconn;
 444         to->udp_out_err_output.value.ui64 += from->udp_out_err_output;
 445         to->udp_out_err_tudr.value.ui64 += from->udp_out_err_tudr;
 446 #ifdef DEBUG
 447         to->udp_data_conn.value.ui64 += from->udp_data_conn;
 448         to->udp_data_notconn.value.ui64 += from->udp_data_notconn;
 449         to->udp_out_lastdst.value.ui64 += from->udp_out_lastdst;
 450         to->udp_out_diffdst.value.ui64 += from->udp_out_diffdst;
 451         to->udp_out_ipv6.value.ui64 += from->udp_out_ipv6;
 452         to->udp_out_mapped.value.ui64 += from->udp_out_mapped;
 453         to->udp_out_ipv4.value.ui64 += from->udp_out_ipv4;
 454 #endif
 455 }
 456 
 457 /*
 458  * To set all udp_stat_t counters to 0.
 459  */
 460 static void
 461 udp_clr_stats(udp_stat_t *stats)
 462 {
 463         stats->udp_sock_fallback.value.ui64 = 0;
 464         stats->udp_out_opt.value.ui64 = 0;
 465         stats->udp_out_err_notconn.value.ui64 = 0;
 466         stats->udp_out_err_output.value.ui64 = 0;
 467         stats->udp_out_err_tudr.value.ui64 = 0;
 468 #ifdef DEBUG
 469         stats->udp_data_conn.value.ui64 = 0;
 470         stats->udp_data_notconn.value.ui64 = 0;
 471         stats->udp_out_lastdst.value.ui64 = 0;
 472         stats->udp_out_diffdst.value.ui64 = 0;
 473         stats->udp_out_ipv6.value.ui64 = 0;
 474         stats->udp_out_mapped.value.ui64 = 0;
 475         stats->udp_out_ipv4.value.ui64 = 0;
 476 #endif
 477 }
 478 
 479 int
 480 udp_kstat2_update(kstat_t *kp, int rw)
 481 {
 482         udp_stat_t      *stats;
 483         netstackid_t    stackid = (netstackid_t)(uintptr_t)kp->ks_private;
 484         netstack_t      *ns;
 485         udp_stack_t     *us;
 486         int             i;
 487         int             cnt;
 488 
 489         if (rw == KSTAT_WRITE)
 490                 return (EACCES);
 491 
 492         ns = netstack_find_by_stackid(stackid);
 493         if (ns == NULL)
 494                 return (-1);
 495         us = ns->netstack_udp;
 496         if (us == NULL) {
 497                 netstack_rele(ns);
 498                 return (-1);
 499         }
 500         stats = (udp_stat_t *)kp->ks_data;
 501         udp_clr_stats(stats);
 502 
 503         cnt = us->us_sc_cnt;
 504         for (i = 0; i < cnt; i++)
 505                 udp_add_stats(&us->us_sc[i]->udp_sc_stats, stats);
 506 
 507         netstack_rele(ns);
 508         return (0);
 509 }
 510 
 511 void *
 512 udp_kstat_init(netstackid_t stackid)
 513 {
 514         kstat_t *ksp;
 515 
 516         udp_named_kstat_t template = {
 517                 { "inDatagrams",        KSTAT_DATA_UINT64, 0 },
 518                 { "inErrors",           KSTAT_DATA_UINT32, 0 },
 519                 { "outDatagrams",       KSTAT_DATA_UINT64, 0 },
 520                 { "entrySize",          KSTAT_DATA_INT32, 0 },
 521                 { "entry6Size",         KSTAT_DATA_INT32, 0 },
 522                 { "outErrors",          KSTAT_DATA_UINT32, 0 },
 523         };
 524 
 525         ksp = kstat_create_netstack(UDP_MOD_NAME, 0, UDP_MOD_NAME, "mib2",
 526             KSTAT_TYPE_NAMED, NUM_OF_FIELDS(udp_named_kstat_t), 0, stackid);
 527 
 528         if (ksp == NULL)
 529                 return (NULL);
 530 
 531         template.entrySize.value.ui32 = sizeof (mib2_udpEntry_t);
 532         template.entry6Size.value.ui32 = sizeof (mib2_udp6Entry_t);
 533 
 534         bcopy(&template, ksp->ks_data, sizeof (template));
 535         ksp->ks_update = udp_kstat_update;
 536         ksp->ks_private = (void *)(uintptr_t)stackid;
 537 
 538         kstat_install(ksp);
 539         return (ksp);
 540 }
 541 
 542 /*
 543  * To sum up all MIB2 stats for a udp_stack_t from all per CPU stats.  The
 544  * caller should initialize the target mib2_udp_t properly as this function
 545  * just adds up all the per CPU stats.
 546  */
 547 static void
 548 udp_sum_mib(udp_stack_t *us, mib2_udp_t *udp_mib)
 549 {
 550         int i;
 551         int cnt;
 552 
 553         cnt = us->us_sc_cnt;
 554         for (i = 0; i < cnt; i++)
 555                 udp_add_mib(&us->us_sc[i]->udp_sc_mib, udp_mib);
 556 }
 557 
 558 static int
 559 udp_kstat_update(kstat_t *kp, int rw)
 560 {
 561         udp_named_kstat_t *udpkp;
 562         netstackid_t    stackid = (netstackid_t)(uintptr_t)kp->ks_private;
 563         netstack_t      *ns;
 564         udp_stack_t     *us;
 565         mib2_udp_t      udp_mib;
 566 
 567         if (rw == KSTAT_WRITE)
 568                 return (EACCES);
 569 
 570         ns = netstack_find_by_stackid(stackid);
 571         if (ns == NULL)
 572                 return (-1);
 573         us = ns->netstack_udp;
 574         if (us == NULL) {
 575                 netstack_rele(ns);
 576                 return (-1);
 577         }
 578         udpkp = (udp_named_kstat_t *)kp->ks_data;
 579 
 580         bzero(&udp_mib, sizeof (udp_mib));
 581         udp_sum_mib(us, &udp_mib);
 582 
 583         udpkp->inDatagrams.value.ui64 =      udp_mib.udpHCInDatagrams;
 584         udpkp->inErrors.value.ui32 = udp_mib.udpInErrors;
 585         udpkp->outDatagrams.value.ui64 = udp_mib.udpHCOutDatagrams;
 586         udpkp->outErrors.value.ui32 =        udp_mib.udpOutErrors;
 587         netstack_rele(ns);
 588         return (0);
 589 }