summaryrefslogtreecommitdiffstats
path: root/zebra/irdp_packet.c
blob: d78348cdf7543ff6713384d8ef8f0f825a9e51ad (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
/*
 *
 * Copyright (C) 2000  Robert Olsson.
 * Swedish University of Agricultural Sciences
 *
 * This file is part of GNU Zebra.
 *
 * GNU Zebra is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the
 * Free Software Foundation; either version 2, or (at your option) any
 * later version.
 *
 * GNU Zebra is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with GNU Zebra; see the file COPYING.  If not, write to the Free
 * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
 * 02111-1307, USA.  
 */

/* 
 * This work includes work with the following copywrite:
 *
 * Copyright (C) 1997, 2000 Kunihiro Ishiguro
 *
 */

/* 
 * Thanks to Jens Låås at Swedish University of Agricultural Sciences
 * for reviewing and tests.
 */


#include <zebra.h>


#ifdef HAVE_IRDP

#include "if.h"
#include "vty.h"
#include "sockunion.h"
#include "prefix.h"
#include "command.h"
#include "memory.h"
#include "stream.h"
#include "ioctl.h"
#include "connected.h"
#include "log.h"
#include "zclient.h"
#include "thread.h"
#include "zebra/interface.h"
#include "zebra/rtadv.h"
#include "zebra/rib.h"
#include "zebra/zserv.h"
#include "zebra/redistribute.h"
#include "zebra/irdp.h"
#include <netinet/ip_icmp.h>
#include "if.h"
#include "sockunion.h"
#include "log.h"
#include "sockopt.h"


/* GLOBAL VARS */

int irdp_sock;
char b1[16], b2[16], b3[16], b4[16];  /* For inet_2a */

extern struct zebra_t zebrad;
extern struct thread *t_irdp_raw;
extern struct interface *get_iflist_ifp(int idx);
int in_cksum (void *ptr, int nbytes);
void process_solicit (struct interface *ifp);

void parse_irdp_packet(char *p, 
		  int len, 
		  struct interface *ifp)
{
  struct ip *ip = (struct ip *)p ;
  struct icmphdr *icmp;
  struct in_addr src;
  int ip_hlen, iplen, datalen;
  struct zebra_if *zi;
  struct irdp_interface *irdp;

  zi = ifp->info;
  if (!zi) 
    return;

  irdp = &zi->irdp;
  if (!irdp) 
    return;

  ip_hlen = ip->ip_hl << 2;
  
  sockopt_iphdrincl_swab_systoh (ip);
  
  iplen = ip->ip_len;
  datalen = len - ip_hlen;
  src = ip->ip_src;

  if (len != iplen)
    {
      zlog_err ("IRDP: RX length doesnt match IP length");
      return;
    }

  if (iplen < ICMP_MINLEN) 
    {
      zlog_err ("IRDP: RX ICMP packet too short from %s\n",
  	      inet_ntoa (src));
      return;
    }
    
  /* XXX: RAW doesnt receive link-layer, surely? ??? */
  /* Check so we don't checksum packets longer than oure RX_BUF - (ethlen +
   len of IP-header) 14+20 */
  if (iplen > IRDP_RX_BUF-34) 
    {
      zlog_err ("IRDP: RX ICMP packet too long from %s\n",
	        inet_ntoa (src));
      return;
    }

  icmp = (struct icmphdr *) (p+ip_hlen);

  /* check icmp checksum */    
  if (in_cksum (icmp, datalen) != icmp->checksum) 
    {
      zlog_warn ("IRDP: RX ICMP packet from %s. Bad checksum, silently ignored",
                 inet_ntoa (src));
      return;
    }
  
  /* Handle just only IRDP */
  if (!(icmp->type == ICMP_ROUTERADVERT
        || icmp->type == ICMP_ROUTERSOLICIT))
    return;
  
  if (icmp->code != 0) 
    {
      zlog_warn ("IRDP: RX packet type %d from %s. Bad ICMP type code,"
                 " silently ignored",
                 icmp->type, inet_ntoa (src));
      return;
    }

  if (! ((ntohl (ip->ip_dst.s_addr) == INADDR_BROADCAST)
         && (irdp->flags & IF_BROADCAST))
        ||
        (ntohl (ip->ip_dst.s_addr) == INADDR_ALLRTRS_GROUP
         && !(irdp->flags & IF_BROADCAST)))
    {
      zlog_warn ("IRDP: RX illegal from %s to %s while %s operates in %s\n",
                 inet_ntoa (src),
                 ntohl (ip->ip_dst.s_addr) == INADDR_ALLRTRS_GROUP ?
                 "multicast" : inet_ntoa (ip->ip_dst),
                 ifp->name,
                 irdp->flags & IF_BROADCAST ? "broadcast" : "multicast");

      zlog_warn ("IRDP: Please correct settings\n");
      return;
    }

  switch (icmp->type) 
    {
    case ICMP_ROUTERADVERT:
      break;

    case ICMP_ROUTERSOLICIT:

      if(irdp->flags & IF_DEBUG_MESSAGES) 
	zlog_warn ("IRDP: RX Solicit on %s from %s\n",
		   ifp->name,
		   inet_ntoa (src));

      process_solicit(ifp);
      break;

    default:
      zlog_warn ("IRDP: RX type %d from %s. Bad ICMP type, silently ignored",
		 icmp->type,
		 inet_ntoa (src));
    }
}

int irdp_recvmsg (int sock, u_char *buf, int size, int *ifindex)
{
  struct msghdr msg;
  struct iovec iov;
  char adata[CMSG_SPACE( SOPT_SIZE_CMSG_PKTINFO_IPV4() )];
  int ret;

  msg.msg_name = (void *)0;
  msg.msg_namelen = 0;
  msg.msg_iov = &iov;
  msg.msg_iovlen = 1;
  msg.msg_control = (void *) adata;
  msg.msg_controllen = sizeof adata;

  iov.iov_base = buf;
  iov.iov_len = size;

  ret = recvmsg (sock, &msg, 0);
  if (ret < 0) {
    zlog_warn("IRDP: recvmsg: read error %s", safe_strerror(errno));
    return ret;
  }

  if (msg.msg_flags & MSG_TRUNC) {
    zlog_warn("IRDP: recvmsg: truncated message");
    return ret;
  }
  if (msg.msg_flags & MSG_CTRUNC) {
    zlog_warn("IRDP: recvmsg: truncated control message");
    return ret;
  }

  *ifindex = getsockopt_ifindex (AF_INET, &msg);

  return ret;
}

int irdp_read_raw(struct thread *r)
{
  struct interface *ifp;
  struct zebra_if *zi;
  struct irdp_interface *irdp;
  char buf[IRDP_RX_BUF];
  int ret, ifindex;
  
  int irdp_sock = THREAD_FD (r);
  t_irdp_raw = thread_add_read (zebrad.master, irdp_read_raw, NULL, irdp_sock);
  
  ret = irdp_recvmsg (irdp_sock, (u_char *) buf, IRDP_RX_BUF,  &ifindex);
 
  if (ret < 0) zlog_warn ("IRDP: RX Error length = %d", ret);

  ifp = get_iflist_ifp(ifindex);
  if(! ifp ) return ret;

  zi= ifp->info;
  if(! zi ) return ret;

  irdp = &zi->irdp;
  if(! irdp ) return ret;

  if(! (irdp->flags & IF_ACTIVE)) {

    if(irdp->flags & IF_DEBUG_MISC) 
      zlog_warn("IRDP: RX ICMP for disabled interface %s\n",
		ifp->name);
    return 0;
  }

  if(irdp->flags & IF_DEBUG_PACKET) {
    int i;
    zlog_warn("IRDP: RX (idx %d) ", ifindex);
    for(i=0; i < ret; i++) zlog_warn( "IRDP: RX %x ", buf[i]&0xFF);
  }

  parse_irdp_packet(buf, ret, ifp);

  return ret;
}

void 
send_packet(struct interface *ifp, 
	    struct stream *s,
	    u_int32_t dst,
	    struct prefix *p,
	    u_int32_t ttl)
{
  static struct sockaddr_in sockdst = {AF_INET};
  struct ip *ip;
  struct icmphdr *icmp;
  struct msghdr *msg;
  struct cmsghdr *cmsg;
  struct iovec iovector;
  char msgbuf[256];
  char buf[256];
  struct in_pktinfo *pktinfo;
  u_long src;
  int on;
 
  if (!(ifp->flags & IFF_UP)) 
    return;

  if (!p) 
    src = ntohl(p->u.prefix4.s_addr);
  else 
    src = 0; /* Is filled in */
  
  ip = (struct ip *) buf;
  ip->ip_hl = sizeof(struct ip) >> 2;
  ip->ip_v = IPVERSION;
  ip->ip_tos = 0xC0;
  ip->ip_off = 0L;
  ip->ip_p = 1;       /* IP_ICMP */
  ip->ip_ttl = ttl;
  ip->ip_src.s_addr = src;
  ip->ip_dst.s_addr = dst;
  icmp = (struct icmphdr *) (buf + sizeof (struct ip));

  /* Merge IP header with icmp packet */

  stream_get(icmp, s, s->putp);

  /* icmp->checksum is already calculated */
  ip->ip_len  = sizeof(struct ip) + s->putp;
  stream_free(s); 

  on = 1;
  if (setsockopt(irdp_sock, IPPROTO_IP, IP_HDRINCL,
		 (char *) &on, sizeof(on)) < 0)
    zlog_warn("sendto %s", safe_strerror (errno));


  if(dst == INADDR_BROADCAST ) {
    on = 1;
    if (setsockopt(irdp_sock, SOL_SOCKET, SO_BROADCAST,
		   (char *) &on, sizeof(on)) < 0)
      zlog_warn("sendto %s", safe_strerror (errno));
  }

  if(dst !=  INADDR_BROADCAST) {
      on = 0; 
      if( setsockopt(irdp_sock,IPPROTO_IP, IP_MULTICAST_LOOP, 
		     (char *)&on,sizeof(on)) < 0)
	zlog_warn("sendto %s", safe_strerror (errno));
  }

  bzero(&sockdst,sizeof(sockdst));
  sockdst.sin_family=AF_INET;
  sockdst.sin_addr.s_addr = dst;

  cmsg = (struct cmsghdr *) (msgbuf + sizeof(struct msghdr));
  cmsg->cmsg_len = sizeof(struct cmsghdr) + sizeof(struct in_pktinfo);
  cmsg->cmsg_level = SOL_IP;
  cmsg->cmsg_type = IP_PKTINFO;
  pktinfo = (struct in_pktinfo *) CMSG_DATA(cmsg);
  pktinfo->ipi_ifindex = ifp->ifindex;
  pktinfo->ipi_spec_dst.s_addr = src;
  pktinfo->ipi_addr.s_addr = src;
 
  iovector.iov_base = (void *) buf;
  iovector.iov_len = ip->ip_len; 
  msg = (struct msghdr *) msgbuf;
  msg->msg_name = &sockdst;
  msg->msg_namelen = sizeof(sockdst);
  msg->msg_iov = &iovector;
  msg->msg_iovlen = 1;
  msg->msg_control = cmsg;
  msg->msg_controllen = cmsg->cmsg_len;
 
  sockopt_iphdrincl_swab_htosys (ip);
  
  if (sendmsg(irdp_sock, msg, 0) < 0) {
    zlog_warn("sendto %s", safe_strerror (errno));
  }
  /*   printf("TX on %s idx %d\n", ifp->name, ifp->ifindex); */
}


#endif /* HAVE_IRDP */