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 #include <sys/stream.h>
  35 #include <sys/tihdr.h>
  36
  37 /* Solaris defines these in both <netinet/in.h> and <inet/in.h>, sigh */
  38 #ifdef SUNOS_5
  39 #include <sys/tiuser.h>
  40 #ifndef T_CURRENT
  41 #define T_CURRENT       MI_T_CURRENT
  42 #endif /* T_CURRENT */
  43 #ifndef IRE_CACHE
  44 #define IRE_CACHE               0x0020  /* Cached Route entry */
  45 #endif /* IRE_CACHE */
  46 #ifndef IRE_HOST_REDIRECT
  47 #define IRE_HOST_REDIRECT       0x0200  /* Host route entry from redirects */
  48 #endif /* IRE_HOST_REDIRECT */
  49 #ifndef IRE_CACHETABLE
  50 #define IRE_CACHETABLE          (IRE_CACHE | IRE_BROADCAST | IRE_LOCAL | \
  51                                  IRE_LOOPBACK)
  52 #endif /* IRE_CACHETABLE */
  53 #undef IPOPT_EOL
  54 #undef IPOPT_NOP
  55 #undef IPOPT_LSRR
  56 #undef IPOPT_RR
  57 #undef IPOPT_SSRR
  58 #endif /* SUNOS_5 */
  59
  60 #include <inet/common.h>
  61 #include <inet/ip.h>
  62 #include <inet/mib2.h>
  63
  64 /* device to read IP routing table from */
  65 #ifndef _PATH_GETMSG_ROUTE
  66 #define _PATH_GETMSG_ROUTE      "/dev/ip"
  67 #endif /* _PATH_GETMSG_ROUTE */
  68
  69 #define RT_BUFSIZ               8192
  70
  71 static void
  72 handle_route_entry (mib2_ipRouteEntry_t *routeEntry)
  73 {
  74   struct prefix prefix;
  75   struct in_addr                tmpaddr, gateway;
  76   union g_addr *ggateway;
  77   u_char                        zebra_flags = 0;
  78
  79   if (routeEntry->ipRouteInfo.re_ire_type & IRE_CACHETABLE)
  80     return;
  81
  82   if (routeEntry->ipRouteInfo.re_ire_type & IRE_HOST_REDIRECT)
  83     zebra_flags |= ZEBRA_FLAG_SELFROUTE;
  84
  85   prefix.family = AF_INET;
  86
  87   tmpaddr.s_addr = routeEntry->ipRouteDest;
  88   prefix.u.prefix4 = tmpaddr;
  89
  90   tmpaddr.s_addr = routeEntry->ipRouteMask;
  91   prefix.prefixlen = ip_masklen (tmpaddr);
  92
  93   gateway.s_addr = routeEntry->ipRouteNextHop;
  94   ggateway = (union g_addr *)&gateway;
  95
  96   rib_add (AFI_IP, SAFI_UNICAST, VRF_DEFAULT, ZEBRA_ROUTE_KERNEL, 0,
  97            zebra_flags, &prefix, NULL, ggateway, NULL, 0, 0, 0, 0, 0);
  98 }
  99
 100 void
 101 route_read (struct zebra_ns *zns)
 102 {
 103         char                    storage[RT_BUFSIZ];
 104
 105         struct T_optmgmt_req    *TLIreq = (struct T_optmgmt_req *) storage;
 106         struct T_optmgmt_ack    *TLIack = (struct T_optmgmt_ack *) storage;
 107         struct T_error_ack      *TLIerr = (struct T_error_ack *) storage;
 108
 109         struct opthdr           *MIB2hdr;
 110
 111         mib2_ipRouteEntry_t     *routeEntry, *lastRouteEntry;
 112
 113         struct strbuf           msgdata;
 114         int                     flags, dev, retval, process;
 115
 116         if ((dev = open (_PATH_GETMSG_ROUTE, O_RDWR)) == -1) {
 117                 zlog_warn ("can't open %s: %s", _PATH_GETMSG_ROUTE,
 118                         safe_strerror (errno));
 119                 return;
 120         }
 121
 122         TLIreq->PRIM_type = T_OPTMGMT_REQ;
 123         TLIreq->OPT_offset = sizeof (struct T_optmgmt_req);
 124         TLIreq->OPT_length = sizeof (struct opthdr);
 125         TLIreq->MGMT_flags = T_CURRENT;
 126
 127         MIB2hdr = (struct opthdr *) &TLIreq[1];
 128
 129         MIB2hdr->level = MIB2_IP;
 130         MIB2hdr->name = 0;
 131         MIB2hdr->len = 0;
 132
 133         msgdata.buf = storage;
 134         msgdata.len = sizeof (struct T_optmgmt_req) + sizeof (struct opthdr);
 135
 136         flags = 0;
 137
 138         if (putmsg (dev, &msgdata, NULL, flags) == -1) {
 139                 zlog_warn ("putmsg failed: %s", safe_strerror (errno));
 140                 goto exit;
 141         }
 142
 143         MIB2hdr = (struct opthdr *) &TLIack[1];
 144         msgdata.maxlen = sizeof (storage);
 145
 146         while (1) {
 147                 flags = 0;
 148                 retval = getmsg (dev, &msgdata, NULL, &flags);
 149
 150                 if (retval == -1) {
 151                         zlog_warn ("getmsg(ctl) failed: %s", safe_strerror (errno));
 152                         goto exit;
 153                 }
 154
 155                 /* This is normal loop termination */
 156                 if (retval == 0 &&
 157                         (size_t)msgdata.len >= sizeof (struct T_optmgmt_ack) &&
 158                         TLIack->PRIM_type == T_OPTMGMT_ACK &&
 159                         TLIack->MGMT_flags == T_SUCCESS &&
 160                         MIB2hdr->len == 0)
 161                         break;
 162
 163                 if ((size_t)msgdata.len >= sizeof (struct T_error_ack) &&
 164                         TLIerr->PRIM_type == T_ERROR_ACK) {
 165                         zlog_warn ("getmsg(ctl) returned T_ERROR_ACK: %s",
 166                                 safe_strerror ((TLIerr->TLI_error == TSYSERR)
 167                                 ? TLIerr->UNIX_error : EPROTO));
 168                         break;
 169                 }
 170
 171                 /* should dump more debugging info to the log statement,
 172                    like what GateD does in this instance, but not
 173                    critical yet. */
 174                 if (retval != MOREDATA ||
 175                         (size_t)msgdata.len < sizeof (struct T_optmgmt_ack) ||
 176                         TLIack->PRIM_type != T_OPTMGMT_ACK ||
 177                         TLIack->MGMT_flags != T_SUCCESS) {
 178                         errno = ENOMSG;
 179                         zlog_warn ("getmsg(ctl) returned bizarreness");
 180                         break;
 181                 }
 182
 183                 /* MIB2_IP_21 is the the pseudo-MIB2 ipRouteTable
 184                    entry, see <inet/mib2.h>. "This isn't the MIB data
 185                    you're looking for." */
 186                 process = (MIB2hdr->level == MIB2_IP &&
 187                         MIB2hdr->name == MIB2_IP_21) ? 1 : 0;
 188
 189                 /* getmsg writes the data buffer out completely, not
 190                    to the closest smaller multiple. Unless reassembling
 191                    data structures across buffer boundaries is your idea
 192                    of a good time, set maxlen to the closest smaller
 193                    multiple of the size of the datastructure you're
 194                    retrieving. */
 195                 msgdata.maxlen = sizeof (storage) - (sizeof (storage)
 196                         % sizeof (mib2_ipRouteEntry_t));
 197
 198                 msgdata.len = 0;
 199                 flags = 0;
 200
 201                 do {
 202                         retval = getmsg (dev, NULL, &msgdata, &flags);
 203
 204                         if (retval == -1) {
 205                                 zlog_warn ("getmsg(data) failed: %s",
 206                                         safe_strerror (errno));
 207                                 goto exit;
 208                         }
 209
 210                         if (!(retval == 0 || retval == MOREDATA)) {
 211                                 zlog_warn ("getmsg(data) returned %d", retval);
 212                                 goto exit;
 213                         }
 214
 215                         if (process) {
 216                                 if (msgdata.len %
 217                                         sizeof (mib2_ipRouteEntry_t) != 0) {
 218                                         zlog_warn ("getmsg(data) returned "
 219 "msgdata.len = %d (%% sizeof (mib2_ipRouteEntry_t) != 0)", msgdata.len);
 220                                         goto exit;
 221                                 }
 222
 223                                 routeEntry = (mib2_ipRouteEntry_t *)
 224                                         msgdata.buf;
 225                                 lastRouteEntry = (mib2_ipRouteEntry_t *)
 226                                         (msgdata.buf + msgdata.len);
 227                                 do {
 228                                         handle_route_entry (routeEntry);
 229                                 } while (++routeEntry < lastRouteEntry);
 230                         }
 231                 } while (retval == MOREDATA);
 232         }
 233
 234 exit:
 235         close (dev);
 236 }