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
  30 #include "zebra/rib.h"
  31 #include "zebra/zserv.h"
  32
  33 #include <sys/stream.h>
  34 #include <sys/tihdr.h>
  35
  36 /* Solaris defines these in both <netinet/in.h> and <inet/in.h>, sigh */
  37 #ifdef SUNOS_5
  38 #include <sys/tiuser.h>
  39 #ifndef T_CURRENT
  40 #define T_CURRENT       MI_T_CURRENT
  41 #endif /* T_CURRENT */
  42 #ifndef IRE_CACHE
  43 #define IRE_CACHE               0x0020  /* Cached Route entry */
  44 #endif /* IRE_CACHE */
  45 #ifndef IRE_HOST_REDIRECT
  46 #define IRE_HOST_REDIRECT       0x0200  /* Host route entry from redirects */
  47 #endif /* IRE_HOST_REDIRECT */
  48 #ifndef IRE_CACHETABLE
  49 #define IRE_CACHETABLE          (IRE_CACHE | IRE_BROADCAST | IRE_LOCAL | \
  50                                  IRE_LOOPBACK)
  51 #endif /* IRE_CACHETABLE */
  52 #undef IPOPT_EOL
  53 #undef IPOPT_NOP
  54 #undef IPOPT_LSRR
  55 #undef IPOPT_RR
  56 #undef IPOPT_SSRR
  57 #endif /* SUNOS_5 */
  58
  59 #include <inet/common.h>
  60 #include <inet/ip.h>
  61 #include <inet/mib2.h>
  62
  63 /* device to read IP routing table from */
  64 #ifndef _PATH_GETMSG_ROUTE
  65 #define _PATH_GETMSG_ROUTE      "/dev/ip"
  66 #endif /* _PATH_GETMSG_ROUTE */
  67
  68 #define RT_BUFSIZ               8192
  69
  70 static void
  71 handle_route_entry (mib2_ipRouteEntry_t *routeEntry)
  72 {
  73         struct prefix_ipv4      prefix;
  74         struct in_addr          tmpaddr, gateway;
  75         u_char                  zebra_flags = 0;
  76
  77         if (routeEntry->ipRouteInfo.re_ire_type & IRE_CACHETABLE)
  78                 return;
  79
  80         if (routeEntry->ipRouteInfo.re_ire_type & IRE_HOST_REDIRECT)
  81                 zebra_flags |= ZEBRA_FLAG_SELFROUTE;
  82
  83         prefix.family = AF_INET;
  84
  85         tmpaddr.s_addr = routeEntry->ipRouteDest;
  86         prefix.prefix = tmpaddr;
  87
  88         tmpaddr.s_addr = routeEntry->ipRouteMask;
  89         prefix.prefixlen = ip_masklen (tmpaddr);
  90
  91         gateway.s_addr = routeEntry->ipRouteNextHop;
  92
  93         rib_add_ipv4 (ZEBRA_ROUTE_KERNEL, 0, zebra_flags, &prefix,
  94                       &gateway, NULL, 0, VRF_DEFAULT, 0, 0, 0, SAFI_UNICAST);
  95 }
  96
  97 void
  98 route_read (struct zebra_vrf *zvrf)
  99 {
 100         char                    storage[RT_BUFSIZ];
 101
 102         struct T_optmgmt_req    *TLIreq = (struct T_optmgmt_req *) storage;
 103         struct T_optmgmt_ack    *TLIack = (struct T_optmgmt_ack *) storage;
 104         struct T_error_ack      *TLIerr = (struct T_error_ack *) storage;
 105
 106         struct opthdr           *MIB2hdr;
 107
 108         mib2_ipRouteEntry_t     *routeEntry, *lastRouteEntry;
 109
 110         struct strbuf           msgdata;
 111         int                     flags, dev, retval, process;
 112
 113         if (zvrf->vrf_id != VRF_DEFAULT) {
 114                 return;
 115         }
 116
 117         if ((dev = open (_PATH_GETMSG_ROUTE, O_RDWR)) == -1) {
 118                 zlog_warn ("can't open %s: %s", _PATH_GETMSG_ROUTE,
 119                         safe_strerror (errno));
 120                 return;
 121         }
 122
 123         TLIreq->PRIM_type = T_OPTMGMT_REQ;
 124         TLIreq->OPT_offset = sizeof (struct T_optmgmt_req);
 125         TLIreq->OPT_length = sizeof (struct opthdr);
 126         TLIreq->MGMT_flags = T_CURRENT;
 127
 128         MIB2hdr = (struct opthdr *) &TLIreq[1];
 129
 130         MIB2hdr->level = MIB2_IP;
 131         MIB2hdr->name = 0;
 132         MIB2hdr->len = 0;
 133
 134         msgdata.buf = storage;
 135         msgdata.len = sizeof (struct T_optmgmt_req) + sizeof (struct opthdr);
 136
 137         flags = 0;
 138
 139         if (putmsg (dev, &msgdata, NULL, flags) == -1) {
 140                 zlog_warn ("putmsg failed: %s", safe_strerror (errno));
 141                 goto exit;
 142         }
 143
 144         MIB2hdr = (struct opthdr *) &TLIack[1];
 145         msgdata.maxlen = sizeof (storage);
 146
 147         while (1) {
 148                 flags = 0;
 149                 retval = getmsg (dev, &msgdata, NULL, &flags);
 150
 151                 if (retval == -1) {
 152                         zlog_warn ("getmsg(ctl) failed: %s", safe_strerror (errno));
 153                         goto exit;
 154                 }
 155
 156                 /* This is normal loop termination */
 157                 if (retval == 0 &&
 158                         msgdata.len >= sizeof (struct T_optmgmt_ack) &&
 159                         TLIack->PRIM_type == T_OPTMGMT_ACK &&
 160                         TLIack->MGMT_flags == T_SUCCESS &&
 161                         MIB2hdr->len == 0)
 162                         break;
 163
 164                 if (msgdata.len >= sizeof (struct T_error_ack) &&
 165                         TLIerr->PRIM_type == T_ERROR_ACK) {
 166                         zlog_warn ("getmsg(ctl) returned T_ERROR_ACK: %s",
 167                                 safe_strerror ((TLIerr->TLI_error == TSYSERR)
 168                                 ? TLIerr->UNIX_error : EPROTO));
 169                         break;
 170                 }
 171
 172                 /* should dump more debugging info to the log statement,
 173                    like what GateD does in this instance, but not
 174                    critical yet. */
 175                 if (retval != MOREDATA ||
 176                         msgdata.len < sizeof (struct T_optmgmt_ack) ||
 177                         TLIack->PRIM_type != T_OPTMGMT_ACK ||
 178                         TLIack->MGMT_flags != T_SUCCESS) {
 179                         errno = ENOMSG;
 180                         zlog_warn ("getmsg(ctl) returned bizarreness");
 181                         break;
 182                 }
 183
 184                 /* MIB2_IP_21 is the the pseudo-MIB2 ipRouteTable
 185                    entry, see <inet/mib2.h>. "This isn't the MIB data
 186                    you're looking for." */
 187                 process = (MIB2hdr->level == MIB2_IP &&
 188                         MIB2hdr->name == MIB2_IP_21) ? 1 : 0;
 189
 190                 /* getmsg writes the data buffer out completely, not
 191                    to the closest smaller multiple. Unless reassembling
 192                    data structures across buffer boundaries is your idea
 193                    of a good time, set maxlen to the closest smaller
 194                    multiple of the size of the datastructure you're
 195                    retrieving. */
 196                 msgdata.maxlen = sizeof (storage) - (sizeof (storage)
 197                         % sizeof (mib2_ipRouteEntry_t));
 198
 199                 msgdata.len = 0;
 200                 flags = 0;
 201
 202                 do {
 203                         retval = getmsg (dev, NULL, &msgdata, &flags);
 204
 205                         if (retval == -1) {
 206                                 zlog_warn ("getmsg(data) failed: %s",
 207                                         safe_strerror (errno));
 208                                 goto exit;
 209                         }
 210
 211                         if (!(retval == 0 || retval == MOREDATA)) {
 212                                 zlog_warn ("getmsg(data) returned %d", retval);
 213                                 goto exit;
 214                         }
 215
 216                         if (process) {
 217                                 if (msgdata.len %
 218                                         sizeof (mib2_ipRouteEntry_t) != 0) {
 219                                         zlog_warn ("getmsg(data) returned "
 220 "msgdata.len = %d (%% sizeof (mib2_ipRouteEntry_t) != 0)", msgdata.len);
 221                                         goto exit;
 222                                 }
 223
 224                                 routeEntry = (mib2_ipRouteEntry_t *)
 225                                         msgdata.buf;
 226                                 lastRouteEntry = (mib2_ipRouteEntry_t *)
 227                                         (msgdata.buf + msgdata.len);
 228                                 do {
 229                                         handle_route_entry (routeEntry);
 230                                 } while (++routeEntry < lastRouteEntry);
 231                         }
 232                 } while (retval == MOREDATA);
 233         }
 234
 235 exit:
 236         close (dev);
 237 }