zebra/irdp_packet.c

   1 /*
   2  *
   3  * Copyright (C) 2000  Robert Olsson.
   4  * Swedish University of Agricultural Sciences
   5  *
   6  * This file is part of GNU Zebra.
   7  *
   8  * GNU Zebra is free software; you can redistribute it and/or modify it
   9  * under the terms of the GNU General Public License as published by the
  10  * Free Software Foundation; either version 2, or (at your option) any
  11  * later version.
  12  *
  13  * GNU Zebra is distributed in the hope that it will be useful, but
  14  * WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  * General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with GNU Zebra; see the file COPYING.  If not, write to the Free
  20  * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
  21  * 02111-1307, USA.
  22  */
  23
  24 /*
  25  * This work includes work with the following copywrite:
  26  *
  27  * Copyright (C) 1997, 2000 Kunihiro Ishiguro
  28  *
  29  */
  30
  31 /*
  32  * Thanks to Jens Låås at Swedish University of Agricultural Sciences
  33  * for reviewing and tests.
  34  */
  35
  36
  37 #include <zebra.h>
  38
  39
  40 #ifdef HAVE_IRDP
  41
  42 #include "if.h"
  43 #include "vty.h"
  44 #include "sockunion.h"
  45 #include "prefix.h"
  46 #include "command.h"
  47 #include "memory.h"
  48 #include "zebra_memory.h"
  49 #include "stream.h"
  50 #include "ioctl.h"
  51 #include "connected.h"
  52 #include "log.h"
  53 #include "zclient.h"
  54 #include "thread.h"
  55 #include "zebra/interface.h"
  56 #include "zebra/rtadv.h"
  57 #include "zebra/rib.h"
  58 #include "zebra/zserv.h"
  59 #include "zebra/redistribute.h"
  60 #include "zebra/irdp.h"
  61 #include <netinet/ip_icmp.h>
  62 #include "if.h"
  63 #include "checksum.h"
  64 #include "sockunion.h"
  65 #include "log.h"
  66 #include "sockopt.h"
  67
  68
  69 /* GLOBAL VARS */
  70
  71 int irdp_sock = -1;
  72
  73 extern struct thread *t_irdp_raw;
  74
  75 static void
  76 parse_irdp_packet(char *p,
  77                   int len,
  78                   struct interface *ifp)
  79 {
  80   struct ip *ip = (struct ip *)p ;
  81   struct icmphdr *icmp;
  82   struct in_addr src;
  83   int ip_hlen, iplen, datalen;
  84   struct zebra_if *zi;
  85   struct irdp_interface *irdp;
  86
  87   zi = ifp->info;
  88   if (!zi)
  89     return;
  90
  91   irdp = &zi->irdp;
  92   if (!irdp)
  93     return;
  94
  95   ip_hlen = ip->ip_hl << 2;
  96
  97   sockopt_iphdrincl_swab_systoh (ip);
  98
  99   iplen = ip->ip_len;
 100   datalen = len - ip_hlen;
 101   src = ip->ip_src;
 102
 103   if (len != iplen)
 104     {
 105       zlog_err ("IRDP: RX length doesnt match IP length");
 106       return;
 107     }
 108
 109   if (iplen < ICMP_MINLEN)
 110     {
 111       zlog_err ("IRDP: RX ICMP packet too short from %s\n",
 112               inet_ntoa (src));
 113       return;
 114     }
 115
 116   /* XXX: RAW doesnt receive link-layer, surely? ??? */
 117   /* Check so we don't checksum packets longer than oure RX_BUF - (ethlen +
 118    len of IP-header) 14+20 */
 119   if (iplen > IRDP_RX_BUF-34)
 120     {
 121       zlog_err ("IRDP: RX ICMP packet too long from %s\n",
 122                 inet_ntoa (src));
 123       return;
 124     }
 125
 126   icmp = (struct icmphdr *) (p+ip_hlen);
 127
 128   /* check icmp checksum */
 129   if (in_cksum (icmp, datalen) != icmp->checksum)
 130     {
 131       zlog_warn ("IRDP: RX ICMP packet from %s. Bad checksum, silently ignored",
 132                  inet_ntoa (src));
 133       return;
 134     }
 135
 136   /* Handle just only IRDP */
 137   if (!(icmp->type == ICMP_ROUTERADVERT
 138         || icmp->type == ICMP_ROUTERSOLICIT))
 139     return;
 140
 141   if (icmp->code != 0)
 142     {
 143       zlog_warn ("IRDP: RX packet type %d from %s. Bad ICMP type code,"
 144                  " silently ignored",
 145                  icmp->type, inet_ntoa (src));
 146       return;
 147     }
 148
 149   if (! ((ntohl (ip->ip_dst.s_addr) == INADDR_BROADCAST)
 150          && (irdp->flags & IF_BROADCAST))
 151         ||
 152         (ntohl (ip->ip_dst.s_addr) == INADDR_ALLRTRS_GROUP
 153          && !(irdp->flags & IF_BROADCAST)))
 154     {
 155       zlog_warn ("IRDP: RX illegal from %s to %s while %s operates in %s\n",
 156                  inet_ntoa (src),
 157                  ntohl (ip->ip_dst.s_addr) == INADDR_ALLRTRS_GROUP ?
 158                  "multicast" : inet_ntoa (ip->ip_dst),
 159                  ifp->name,
 160                  irdp->flags & IF_BROADCAST ? "broadcast" : "multicast");
 161
 162       zlog_warn ("IRDP: Please correct settings\n");
 163       return;
 164     }
 165
 166   switch (icmp->type)
 167     {
 168     case ICMP_ROUTERADVERT:
 169       break;
 170
 171     case ICMP_ROUTERSOLICIT:
 172
 173       if(irdp->flags & IF_DEBUG_MESSAGES)
 174         zlog_debug ("IRDP: RX Solicit on %s from %s\n",
 175                     ifp->name,
 176                     inet_ntoa (src));
 177
 178       process_solicit(ifp);
 179       break;
 180
 181     default:
 182       zlog_warn ("IRDP: RX type %d from %s. Bad ICMP type, silently ignored",
 183                  icmp->type,
 184                  inet_ntoa (src));
 185     }
 186 }
 187
 188 static int
 189 irdp_recvmsg (int sock, u_char *buf, int size, int *ifindex)
 190 {
 191   struct msghdr msg;
 192   struct iovec iov;
 193   char adata[CMSG_SPACE( SOPT_SIZE_CMSG_PKTINFO_IPV4() )];
 194   int ret;
 195
 196   msg.msg_name = (void *)0;
 197   msg.msg_namelen = 0;
 198   msg.msg_iov = &iov;
 199   msg.msg_iovlen = 1;
 200   msg.msg_control = (void *) adata;
 201   msg.msg_controllen = sizeof adata;
 202
 203   iov.iov_base = buf;
 204   iov.iov_len = size;
 205
 206   ret = recvmsg (sock, &msg, 0);
 207   if (ret < 0) {
 208     zlog_warn("IRDP: recvmsg: read error %s", safe_strerror(errno));
 209     return ret;
 210   }
 211
 212   if (msg.msg_flags & MSG_TRUNC) {
 213     zlog_warn("IRDP: recvmsg: truncated message");
 214     return ret;
 215   }
 216   if (msg.msg_flags & MSG_CTRUNC) {
 217     zlog_warn("IRDP: recvmsg: truncated control message");
 218     return ret;
 219   }
 220
 221   *ifindex = getsockopt_ifindex (AF_INET, &msg);
 222
 223   return ret;
 224 }
 225
 226 int irdp_read_raw(struct thread *r)
 227 {
 228   struct interface *ifp;
 229   struct zebra_if *zi;
 230   struct irdp_interface *irdp;
 231   char buf[IRDP_RX_BUF];
 232   int ret, ifindex = 0;
 233
 234   int irdp_sock = THREAD_FD (r);
 235   t_irdp_raw = thread_add_read (zebrad.master, irdp_read_raw, NULL, irdp_sock);
 236
 237   ret = irdp_recvmsg (irdp_sock, (u_char *) buf, IRDP_RX_BUF,  &ifindex);
 238
 239   if (ret < 0) zlog_warn ("IRDP: RX Error length = %d", ret);
 240
 241   ifp = if_lookup_by_index(ifindex);
 242   if(! ifp ) return ret;
 243
 244   zi= ifp->info;
 245   if(! zi ) return ret;
 246
 247   irdp = &zi->irdp;
 248   if(! irdp ) return ret;
 249
 250   if(! (irdp->flags & IF_ACTIVE)) {
 251
 252     if(irdp->flags & IF_DEBUG_MISC)
 253       zlog_debug("IRDP: RX ICMP for disabled interface %s\n", ifp->name);
 254     return 0;
 255   }
 256
 257   if(irdp->flags & IF_DEBUG_PACKET) {
 258     int i;
 259     zlog_debug("IRDP: RX (idx %d) ", ifindex);
 260     for(i=0; i < ret; i++) zlog_debug( "IRDP: RX %x ", buf[i]&0xFF);
 261   }
 262
 263   parse_irdp_packet(buf, ret, ifp);
 264
 265   return ret;
 266 }
 267
 268 void
 269 send_packet(struct interface *ifp,
 270             struct stream *s,
 271             u_int32_t dst,
 272             struct prefix *p,
 273             u_int32_t ttl)
 274 {
 275   static struct sockaddr_in sockdst = {AF_INET};
 276   struct ip *ip;
 277   struct icmphdr *icmp;
 278   struct msghdr *msg;
 279   struct cmsghdr *cmsg;
 280   struct iovec iovector;
 281   char msgbuf[256];
 282   char buf[256];
 283   struct in_pktinfo *pktinfo;
 284   u_long src;
 285   int on;
 286
 287   if (!(ifp->flags & IFF_UP))
 288     return;
 289
 290   if (p)
 291     src = ntohl(p->u.prefix4.s_addr);
 292   else
 293     src = 0; /* Is filled in */
 294
 295   ip = (struct ip *) buf;
 296   ip->ip_hl = sizeof(struct ip) >> 2;
 297   ip->ip_v = IPVERSION;
 298   ip->ip_tos = 0xC0;
 299   ip->ip_off = 0L;
 300   ip->ip_p = 1;       /* IP_ICMP */
 301   ip->ip_ttl = ttl;
 302   ip->ip_src.s_addr = src;
 303   ip->ip_dst.s_addr = dst;
 304   icmp = (struct icmphdr *) (buf + sizeof (struct ip));
 305
 306   /* Merge IP header with icmp packet */
 307   assert (stream_get_endp(s) < (sizeof (buf) - sizeof (struct ip)));
 308   stream_get(icmp, s, stream_get_endp(s));
 309
 310   /* icmp->checksum is already calculated */
 311   ip->ip_len  = sizeof(struct ip) + stream_get_endp(s);
 312
 313   on = 1;
 314   if (setsockopt(irdp_sock, IPPROTO_IP, IP_HDRINCL,
 315                  (char *) &on, sizeof(on)) < 0)
 316     zlog_warn("sendto %s", safe_strerror (errno));
 317
 318
 319   if(dst == INADDR_BROADCAST ) {
 320     on = 1;
 321     if (setsockopt(irdp_sock, SOL_SOCKET, SO_BROADCAST,
 322                    (char *) &on, sizeof(on)) < 0)
 323       zlog_warn("sendto %s", safe_strerror (errno));
 324   }
 325
 326   if(dst !=  INADDR_BROADCAST) {
 327       on = 0;
 328       if( setsockopt(irdp_sock,IPPROTO_IP, IP_MULTICAST_LOOP,
 329                      (char *)&on,sizeof(on)) < 0)
 330         zlog_warn("sendto %s", safe_strerror (errno));
 331   }
 332
 333   memset(&sockdst,0,sizeof(sockdst));
 334   sockdst.sin_family=AF_INET;
 335   sockdst.sin_addr.s_addr = dst;
 336
 337   cmsg = (struct cmsghdr *) (msgbuf + sizeof(struct msghdr));
 338   cmsg->cmsg_len = sizeof(struct cmsghdr) + sizeof(struct in_pktinfo);
 339   cmsg->cmsg_level = SOL_IP;
 340   cmsg->cmsg_type = IP_PKTINFO;
 341   pktinfo = (struct in_pktinfo *) CMSG_DATA(cmsg);
 342   pktinfo->ipi_ifindex = ifp->ifindex;
 343   pktinfo->ipi_spec_dst.s_addr = src;
 344   pktinfo->ipi_addr.s_addr = src;
 345
 346   iovector.iov_base = (void *) buf;
 347   iovector.iov_len = ip->ip_len;
 348   msg = (struct msghdr *) msgbuf;
 349   msg->msg_name = &sockdst;
 350   msg->msg_namelen = sizeof(sockdst);
 351   msg->msg_iov = &iovector;
 352   msg->msg_iovlen = 1;
 353   msg->msg_control = cmsg;
 354   msg->msg_controllen = cmsg->cmsg_len;
 355
 356   sockopt_iphdrincl_swab_htosys (ip);
 357
 358   if (sendmsg(irdp_sock, msg, 0) < 0) {
 359     zlog_warn("sendto %s", safe_strerror (errno));
 360   }
 361   /*   printf("TX on %s idx %d\n", ifp->name, ifp->ifindex); */
 362 }
 363
 364
 365 #endif /* HAVE_IRDP */
 366
 367
 368