zebra/rtread_getmsg.c

   1 /*
   2  * Kernel routing table readup by getmsg(2)
   3  * Copyright (C) 1999 Michael Handler
   4  *
   5  * This file is part of GNU Zebra.
   6  *
   7  * GNU Zebra is free software; you can redistribute it and/or modify it
   8  * under the terms of the GNU General Public License as published by the
   9  * Free Software Foundation; either version 2, or (at your option) any
  10  * later version.
  11  *
  12  * GNU Zebra is distributed in the hope that it will be useful, but
  13  * WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with GNU Zebra; see the file COPYING.  If not, write to the Free
  19  * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
  20  * 02111-1307, USA.
  21  */
  22
  23 #include <zebra.h>
  24
  25 #include "prefix.h"
  26 #include "log.h"
  27 #include "if.h"
  28 #include "vrf.h"
  29 #include "vty.h"
  30
  31 #include "zebra/rib.h"
  32 #include "zebra/zserv.h"
  33
  34 /* Thank you, Solaris, for polluting application symbol namespace. */
  35 #undef hook_register
  36 #undef hook_unregister
  37
  38 #include <sys/stream.h>
  39 #include <sys/tihdr.h>
  40
  41 /* Solaris defines these in both <netinet/in.h> and <inet/in.h>, sigh */
  42 #ifdef SUNOS_5
  43 #include <sys/tiuser.h>
  44 #ifndef T_CURRENT
  45 #define T_CURRENT       MI_T_CURRENT
  46 #endif /* T_CURRENT */
  47 #ifndef IRE_CACHE
  48 #define IRE_CACHE               0x0020  /* Cached Route entry */
  49 #endif /* IRE_CACHE */
  50 #ifndef IRE_HOST_REDIRECT
  51 #define IRE_HOST_REDIRECT       0x0200  /* Host route entry from redirects */
  52 #endif /* IRE_HOST_REDIRECT */
  53 #ifndef IRE_CACHETABLE
  54 #define IRE_CACHETABLE          (IRE_CACHE | IRE_BROADCAST | IRE_LOCAL | \
  55                                  IRE_LOOPBACK)
  56 #endif /* IRE_CACHETABLE */
  57 #undef IPOPT_EOL
  58 #undef IPOPT_NOP
  59 #undef IPOPT_LSRR
  60 #undef IPOPT_RR
  61 #undef IPOPT_SSRR
  62 #endif /* SUNOS_5 */
  63
  64 #include <inet/common.h>
  65 #include <inet/ip.h>
  66 #include <inet/mib2.h>
  67
  68 /* device to read IP routing table from */
  69 #ifndef _PATH_GETMSG_ROUTE
  70 #define _PATH_GETMSG_ROUTE      "/dev/ip"
  71 #endif /* _PATH_GETMSG_ROUTE */
  72
  73 #define RT_BUFSIZ               8192
  74
  75 static void
  76 handle_route_entry (mib2_ipRouteEntry_t *routeEntry)
  77 {
  78   struct prefix prefix;
  79   struct in_addr                tmpaddr, gateway;
  80   union g_addr *ggateway;
  81   u_char                        zebra_flags = 0;
  82
  83   if (routeEntry->ipRouteInfo.re_ire_type & IRE_CACHETABLE)
  84     return;
  85
  86   if (routeEntry->ipRouteInfo.re_ire_type & IRE_HOST_REDIRECT)
  87     zebra_flags |= ZEBRA_FLAG_SELFROUTE;
  88
  89   prefix.family = AF_INET;
  90
  91   tmpaddr.s_addr = routeEntry->ipRouteDest;
  92   prefix.u.prefix4 = tmpaddr;
  93
  94   tmpaddr.s_addr = routeEntry->ipRouteMask;
  95   prefix.prefixlen = ip_masklen (tmpaddr);
  96
  97   gateway.s_addr = routeEntry->ipRouteNextHop;
  98   ggateway = (union g_addr *)&gateway;
  99
 100   rib_add (AFI_IP, SAFI_UNICAST, VRF_DEFAULT, ZEBRA_ROUTE_KERNEL, 0,
 101            zebra_flags, &prefix, NULL, ggateway, NULL, 0, 0, 0, 0, 0);
 102 }
 103
 104 void
 105 route_read (struct zebra_ns *zns)
 106 {
 107         char                    storage[RT_BUFSIZ];
 108
 109         struct T_optmgmt_req    *TLIreq = (struct T_optmgmt_req *) storage;
 110         struct T_optmgmt_ack    *TLIack = (struct T_optmgmt_ack *) storage;
 111         struct T_error_ack      *TLIerr = (struct T_error_ack *) storage;
 112
 113         struct opthdr           *MIB2hdr;
 114
 115         mib2_ipRouteEntry_t     *routeEntry, *lastRouteEntry;
 116
 117         struct strbuf           msgdata;
 118         int                     flags, dev, retval, process;
 119
 120         if ((dev = open (_PATH_GETMSG_ROUTE, O_RDWR)) == -1) {
 121                 zlog_warn ("can't open %s: %s", _PATH_GETMSG_ROUTE,
 122                         safe_strerror (errno));
 123                 return;
 124         }
 125
 126         TLIreq->PRIM_type = T_OPTMGMT_REQ;
 127         TLIreq->OPT_offset = sizeof (struct T_optmgmt_req);
 128         TLIreq->OPT_length = sizeof (struct opthdr);
 129         TLIreq->MGMT_flags = T_CURRENT;
 130
 131         MIB2hdr = (struct opthdr *) &TLIreq[1];
 132
 133         MIB2hdr->level = MIB2_IP;
 134         MIB2hdr->name = 0;
 135         MIB2hdr->len = 0;
 136
 137         msgdata.buf = storage;
 138         msgdata.len = sizeof (struct T_optmgmt_req) + sizeof (struct opthdr);
 139
 140         flags = 0;
 141
 142         if (putmsg (dev, &msgdata, NULL, flags) == -1) {
 143                 zlog_warn ("putmsg failed: %s", safe_strerror (errno));
 144                 goto exit;
 145         }
 146
 147         MIB2hdr = (struct opthdr *) &TLIack[1];
 148         msgdata.maxlen = sizeof (storage);
 149
 150         while (1) {
 151                 flags = 0;
 152                 retval = getmsg (dev, &msgdata, NULL, &flags);
 153
 154                 if (retval == -1) {
 155                         zlog_warn ("getmsg(ctl) failed: %s", safe_strerror (errno));
 156                         goto exit;
 157                 }
 158
 159                 /* This is normal loop termination */
 160                 if (retval == 0 &&
 161                         (size_t)msgdata.len >= sizeof (struct T_optmgmt_ack) &&
 162                         TLIack->PRIM_type == T_OPTMGMT_ACK &&
 163                         TLIack->MGMT_flags == T_SUCCESS &&
 164                         MIB2hdr->len == 0)
 165                         break;
 166
 167                 if ((size_t)msgdata.len >= sizeof (struct T_error_ack) &&
 168                         TLIerr->PRIM_type == T_ERROR_ACK) {
 169                         zlog_warn ("getmsg(ctl) returned T_ERROR_ACK: %s",
 170                                 safe_strerror ((TLIerr->TLI_error == TSYSERR)
 171                                 ? TLIerr->UNIX_error : EPROTO));
 172                         break;
 173                 }
 174
 175                 /* should dump more debugging info to the log statement,
 176                    like what GateD does in this instance, but not
 177                    critical yet. */
 178                 if (retval != MOREDATA ||
 179                         (size_t)msgdata.len < sizeof (struct T_optmgmt_ack) ||
 180                         TLIack->PRIM_type != T_OPTMGMT_ACK ||
 181                         TLIack->MGMT_flags != T_SUCCESS) {
 182                         errno = ENOMSG;
 183                         zlog_warn ("getmsg(ctl) returned bizarreness");
 184                         break;
 185                 }
 186
 187                 /* MIB2_IP_21 is the the pseudo-MIB2 ipRouteTable
 188                    entry, see <inet/mib2.h>. "This isn't the MIB data
 189                    you're looking for." */
 190                 process = (MIB2hdr->level == MIB2_IP &&
 191                         MIB2hdr->name == MIB2_IP_21) ? 1 : 0;
 192
 193                 /* getmsg writes the data buffer out completely, not
 194                    to the closest smaller multiple. Unless reassembling
 195                    data structures across buffer boundaries is your idea
 196                    of a good time, set maxlen to the closest smaller
 197                    multiple of the size of the datastructure you're
 198                    retrieving. */
 199                 msgdata.maxlen = sizeof (storage) - (sizeof (storage)
 200                         % sizeof (mib2_ipRouteEntry_t));
 201
 202                 msgdata.len = 0;
 203                 flags = 0;
 204
 205                 do {
 206                         retval = getmsg (dev, NULL, &msgdata, &flags);
 207
 208                         if (retval == -1) {
 209                                 zlog_warn ("getmsg(data) failed: %s",
 210                                         safe_strerror (errno));
 211                                 goto exit;
 212                         }
 213
 214                         if (!(retval == 0 || retval == MOREDATA)) {
 215                                 zlog_warn ("getmsg(data) returned %d", retval);
 216                                 goto exit;
 217                         }
 218
 219                         if (process) {
 220                                 if (msgdata.len %
 221                                         sizeof (mib2_ipRouteEntry_t) != 0) {
 222                                         zlog_warn ("getmsg(data) returned "
 223 "msgdata.len = %d (%% sizeof (mib2_ipRouteEntry_t) != 0)", msgdata.len);
 224                                         goto exit;
 225                                 }
 226
 227                                 routeEntry = (mib2_ipRouteEntry_t *)
 228                                         msgdata.buf;
 229                                 lastRouteEntry = (mib2_ipRouteEntry_t *)
 230                                         (msgdata.buf + msgdata.len);
 231                                 do {
 232                                         handle_route_entry (routeEntry);
 233                                 } while (++routeEntry < lastRouteEntry);
 234                         }
 235                 } while (retval == MOREDATA);
 236         }
 237
 238 exit:
 239         close (dev);
 240 }