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