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 "stream.h"
  49 #include "ioctl.h"
  50 #include "connected.h"
  51 #include "log.h"
  52 #include "zclient.h"
  53 #include "thread.h"
  54 #include "zebra/interface.h"
  55 #include "zebra/rtadv.h"
  56 #include "zebra/rib.h"
  57 #include "zebra/zserv.h"
  58 #include "zebra/redistribute.h"
  59 #include "zebra/irdp.h"
  60 #include <netinet/ip_icmp.h>
  61 #include "if.h"
  62 #include "sockunion.h"
  63 #include "log.h"
  64 #include "sockopt.h"
  65
  66
  67 /* GLOBAL VARS */
  68
  69 int irdp_sock = -1;
  70 char b1[16], b2[16], b3[16], b4[16];  /* For inet_2a */
  71
  72 extern struct zebra_t zebrad;
  73 extern struct thread *t_irdp_raw;
  74 int in_cksum (void *ptr, int nbytes);
  75 void process_solicit (struct interface *ifp);
  76
  77 static void
  78 parse_irdp_packet(char *p,
  79                   int len,
  80                   struct interface *ifp)
  81 {
  82   struct ip *ip = (struct ip *)p ;
  83   struct icmphdr *icmp;
  84   struct in_addr src;
  85   int ip_hlen, iplen, datalen;
  86   struct zebra_if *zi;
  87   struct irdp_interface *irdp;
  88
  89   zi = ifp->info;
  90   if (!zi)
  91     return;
  92
  93   irdp = &zi->irdp;
  94   if (!irdp)
  95     return;
  96
  97   ip_hlen = ip->ip_hl << 2;
  98
  99   sockopt_iphdrincl_swab_systoh (ip);
 100
 101   iplen = ip->ip_len;
 102   datalen = len - ip_hlen;
 103   src = ip->ip_src;
 104
 105   if (len != iplen)
 106     {
 107       zlog_err ("IRDP: RX length doesnt match IP length");
 108       return;
 109     }
 110
 111   if (iplen < ICMP_MINLEN)
 112     {
 113       zlog_err ("IRDP: RX ICMP packet too short from %s\n",
 114               inet_ntoa (src));
 115       return;
 116     }
 117
 118   /* XXX: RAW doesnt receive link-layer, surely? ??? */
 119   /* Check so we don't checksum packets longer than oure RX_BUF - (ethlen +
 120    len of IP-header) 14+20 */
 121   if (iplen > IRDP_RX_BUF-34)
 122     {
 123       zlog_err ("IRDP: RX ICMP packet too long from %s\n",
 124                 inet_ntoa (src));
 125       return;
 126     }
 127
 128   icmp = (struct icmphdr *) (p+ip_hlen);
 129
 130   /* check icmp checksum */
 131   if (in_cksum (icmp, datalen) != icmp->checksum)
 132     {
 133       zlog_warn ("IRDP: RX ICMP packet from %s. Bad checksum, silently ignored",
 134                  inet_ntoa (src));
 135       return;
 136     }
 137
 138   /* Handle just only IRDP */
 139   if (!(icmp->type == ICMP_ROUTERADVERT
 140         || icmp->type == ICMP_ROUTERSOLICIT))
 141     return;
 142
 143   if (icmp->code != 0)
 144     {
 145       zlog_warn ("IRDP: RX packet type %d from %s. Bad ICMP type code,"
 146                  " silently ignored",
 147                  icmp->type, inet_ntoa (src));
 148       return;
 149     }
 150
 151   if (! ((ntohl (ip->ip_dst.s_addr) == INADDR_BROADCAST)
 152          && (irdp->flags & IF_BROADCAST))
 153         ||
 154         (ntohl (ip->ip_dst.s_addr) == INADDR_ALLRTRS_GROUP
 155          && !(irdp->flags & IF_BROADCAST)))
 156     {
 157       zlog_warn ("IRDP: RX illegal from %s to %s while %s operates in %s\n",
 158                  inet_ntoa (src),
 159                  ntohl (ip->ip_dst.s_addr) == INADDR_ALLRTRS_GROUP ?
 160                  "multicast" : inet_ntoa (ip->ip_dst),
 161                  ifp->name,
 162                  irdp->flags & IF_BROADCAST ? "broadcast" : "multicast");
 163
 164       zlog_warn ("IRDP: Please correct settings\n");
 165       return;
 166     }
 167
 168   switch (icmp->type)
 169     {
 170     case ICMP_ROUTERADVERT:
 171       break;
 172
 173     case ICMP_ROUTERSOLICIT:
 174
 175       if(irdp->flags & IF_DEBUG_MESSAGES)
 176         zlog_debug ("IRDP: RX Solicit on %s from %s\n",
 177                     ifp->name,
 178                     inet_ntoa (src));
 179
 180       process_solicit(ifp);
 181       break;
 182
 183     default:
 184       zlog_warn ("IRDP: RX type %d from %s. Bad ICMP type, silently ignored",
 185                  icmp->type,
 186                  inet_ntoa (src));
 187     }
 188 }
 189 \f
 190 static int
 191 irdp_recvmsg (int sock, u_char *buf, int size, int *ifindex)
 192 {
 193   struct msghdr msg;
 194   struct iovec iov;
 195   char adata[CMSG_SPACE( SOPT_SIZE_CMSG_PKTINFO_IPV4() )];
 196   int ret;
 197
 198   msg.msg_name = (void *)0;
 199   msg.msg_namelen = 0;
 200   msg.msg_iov = &iov;
 201   msg.msg_iovlen = 1;
 202   msg.msg_control = (void *) adata;
 203   msg.msg_controllen = sizeof adata;
 204
 205   iov.iov_base = buf;
 206   iov.iov_len = size;
 207
 208   ret = recvmsg (sock, &msg, 0);
 209   if (ret < 0) {
 210     zlog_warn("IRDP: recvmsg: read error %s", safe_strerror(errno));
 211     return ret;
 212   }
 213
 214   if (msg.msg_flags & MSG_TRUNC) {
 215     zlog_warn("IRDP: recvmsg: truncated message");
 216     return ret;
 217   }
 218   if (msg.msg_flags & MSG_CTRUNC) {
 219     zlog_warn("IRDP: recvmsg: truncated control message");
 220     return ret;
 221   }
 222
 223   *ifindex = getsockopt_ifindex (AF_INET, &msg);
 224
 225   return ret;
 226 }
 227 \f
 228 int irdp_read_raw(struct thread *r)
 229 {
 230   struct interface *ifp;
 231   struct zebra_if *zi;
 232   struct irdp_interface *irdp;
 233   char buf[IRDP_RX_BUF];
 234   int ret, ifindex;
 235
 236   int irdp_sock = THREAD_FD (r);
 237   t_irdp_raw = thread_add_read (zebrad.master, irdp_read_raw, NULL, irdp_sock);
 238
 239   ret = irdp_recvmsg (irdp_sock, (u_char *) buf, IRDP_RX_BUF,  &ifindex);
 240
 241   if (ret < 0) zlog_warn ("IRDP: RX Error length = %d", ret);
 242
 243   ifp = if_lookup_by_index(ifindex);
 244   if(! ifp ) return ret;
 245
 246   zi= ifp->info;
 247   if(! zi ) return ret;
 248
 249   irdp = &zi->irdp;
 250   if(! irdp ) return ret;
 251
 252   if(! (irdp->flags & IF_ACTIVE)) {
 253
 254     if(irdp->flags & IF_DEBUG_MISC)
 255       zlog_debug("IRDP: RX ICMP for disabled interface %s\n", ifp->name);
 256     return 0;
 257   }
 258
 259   if(irdp->flags & IF_DEBUG_PACKET) {
 260     int i;
 261     zlog_debug("IRDP: RX (idx %d) ", ifindex);
 262     for(i=0; i < ret; i++) zlog_debug( "IRDP: RX %x ", buf[i]&0xFF);
 263   }
 264
 265   parse_irdp_packet(buf, ret, ifp);
 266
 267   return ret;
 268 }
 269 \f
 270 void
 271 send_packet(struct interface *ifp,
 272             struct stream *s,
 273             u_int32_t dst,
 274             struct prefix *p,
 275             u_int32_t ttl)
 276 {
 277   static struct sockaddr_in sockdst = {AF_INET};
 278   struct ip *ip;
 279   struct icmphdr *icmp;
 280   struct msghdr *msg;
 281   struct cmsghdr *cmsg;
 282   struct iovec iovector;
 283   char msgbuf[256];
 284   char buf[256];
 285   struct in_pktinfo *pktinfo;
 286   u_long src;
 287   int on;
 288
 289   if (!(ifp->flags & IFF_UP))
 290     return;
 291
 292   if (!p)
 293     src = ntohl(p->u.prefix4.s_addr);
 294   else
 295     src = 0; /* Is filled in */
 296
 297   ip = (struct ip *) buf;
 298   ip->ip_hl = sizeof(struct ip) >> 2;
 299   ip->ip_v = IPVERSION;
 300   ip->ip_tos = 0xC0;
 301   ip->ip_off = 0L;
 302   ip->ip_p = 1;       /* IP_ICMP */
 303   ip->ip_ttl = ttl;
 304   ip->ip_src.s_addr = src;
 305   ip->ip_dst.s_addr = dst;
 306   icmp = (struct icmphdr *) (buf + sizeof (struct ip));
 307
 308   /* Merge IP header with icmp packet */
 309   assert (stream_get_endp(s) < (sizeof (buf) - sizeof (struct ip)));
 310   stream_get(icmp, s, stream_get_endp(s));
 311
 312   /* icmp->checksum is already calculated */
 313   ip->ip_len  = sizeof(struct ip) + stream_get_endp(s);
 314
 315   on = 1;
 316   if (setsockopt(irdp_sock, IPPROTO_IP, IP_HDRINCL,
 317                  (char *) &on, sizeof(on)) < 0)
 318     zlog_warn("sendto %s", safe_strerror (errno));
 319
 320
 321   if(dst == INADDR_BROADCAST ) {
 322     on = 1;
 323     if (setsockopt(irdp_sock, SOL_SOCKET, SO_BROADCAST,
 324                    (char *) &on, sizeof(on)) < 0)
 325       zlog_warn("sendto %s", safe_strerror (errno));
 326   }
 327
 328   if(dst !=  INADDR_BROADCAST) {
 329       on = 0;
 330       if( setsockopt(irdp_sock,IPPROTO_IP, IP_MULTICAST_LOOP,
 331                      (char *)&on,sizeof(on)) < 0)
 332         zlog_warn("sendto %s", safe_strerror (errno));
 333   }
 334
 335   memset(&sockdst,0,sizeof(sockdst));
 336   sockdst.sin_family=AF_INET;
 337   sockdst.sin_addr.s_addr = dst;
 338
 339   cmsg = (struct cmsghdr *) (msgbuf + sizeof(struct msghdr));
 340   cmsg->cmsg_len = sizeof(struct cmsghdr) + sizeof(struct in_pktinfo);
 341   cmsg->cmsg_level = SOL_IP;
 342   cmsg->cmsg_type = IP_PKTINFO;
 343   pktinfo = (struct in_pktinfo *) CMSG_DATA(cmsg);
 344   pktinfo->ipi_ifindex = ifp->ifindex;
 345   pktinfo->ipi_spec_dst.s_addr = src;
 346   pktinfo->ipi_addr.s_addr = src;
 347
 348   iovector.iov_base = (void *) buf;
 349   iovector.iov_len = ip->ip_len;
 350   msg = (struct msghdr *) msgbuf;
 351   msg->msg_name = &sockdst;
 352   msg->msg_namelen = sizeof(sockdst);
 353   msg->msg_iov = &iovector;
 354   msg->msg_iovlen = 1;
 355   msg->msg_control = cmsg;
 356   msg->msg_controllen = cmsg->cmsg_len;
 357
 358   sockopt_iphdrincl_swab_htosys (ip);
 359
 360   if (sendmsg(irdp_sock, msg, 0) < 0) {
 361     zlog_warn("sendto %s", safe_strerror (errno));
 362   }
 363   /*   printf("TX on %s idx %d\n", ifp->name, ifp->ifindex); */
 364 }
 365
 366
 367 #endif /* HAVE_IRDP */
 368
 369
 370