bsd/netns/ns_error.c

   1 /*
   2  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * The contents of this file constitute Original Code as defined in and
   7  * are subject to the Apple Public Source License Version 1.1 (the
   8  * "License").  You may not use this file except in compliance with the
   9  * License.  Please obtain a copy of the License at
  10  * http://www.apple.com/publicsource and read it before using this file.
  11  *
  12  * This Original Code and all software distributed under the License are
  13  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  14  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  15  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
  17  * License for the specific language governing rights and limitations
  18  * under the License.
  19  *
  20  * @APPLE_LICENSE_HEADER_END@
  21  */
  22 /*
  23  * Copyright (c) 1984, 1988, 1993
  24  *      The Regents of the University of California.  All rights reserved.
  25  *
  26  * Redistribution and use in source and binary forms, with or without
  27  * modification, are permitted provided that the following conditions
  28  * are met:
  29  * 1. Redistributions of source code must retain the above copyright
  30  *    notice, this list of conditions and the following disclaimer.
  31  * 2. Redistributions in binary form must reproduce the above copyright
  32  *    notice, this list of conditions and the following disclaimer in the
  33  *    documentation and/or other materials provided with the distribution.
  34  * 3. All advertising materials mentioning features or use of this software
  35  *    must display the following acknowledgement:
  36  *      This product includes software developed by the University of
  37  *      California, Berkeley and its contributors.
  38  * 4. Neither the name of the University nor the names of its contributors
  39  *    may be used to endorse or promote products derived from this software
  40  *    without specific prior written permission.
  41  *
  42  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  43  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  44  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  45  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  46  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  47  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  48  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  49  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  50  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  51  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  52  * SUCH DAMAGE.
  53  *
  54  *      @(#)ns_error.c  8.1 (Berkeley) 6/10/93
  55  */
  56
  57 #include <sys/param.h>
  58 #include <sys/systm.h>
  59 #include <sys/malloc.h>
  60 #include <sys/mbuf.h>
  61 #include <sys/protosw.h>
  62 #include <sys/socket.h>
  63 #include <sys/time.h>
  64 #include <sys/kernel.h>
  65
  66 #include <net/route.h>
  67
  68 #include <netns/ns.h>
  69 #include <netns/ns_pcb.h>
  70 #include <netns/idp.h>
  71 #include <netns/ns_error.h>
  72
  73 #ifdef lint
  74 #define NS_ERRPRINTFS 1
  75 #endif
  76
  77 #ifdef NS_ERRPRINTFS
  78 /*
  79  * NS_ERR routines: error generation, receive packet processing, and
  80  * routines to turnaround packets back to the originator.
  81  */
  82 int     ns_errprintfs = 0;
  83 #endif
  84
  85 ns_err_x(c)
  86 {
  87         register u_short *w, *lim, *base = ns_errstat.ns_es_codes;
  88         u_short x = c;
  89
  90         /*
  91          * zero is a legit error code, handle specially
  92          */
  93         if (x == 0)
  94                 return (0);
  95         lim = base + NS_ERR_MAX - 1;
  96         for (w = base + 1; w < lim; w++) {
  97                 if (*w == 0)
  98                         *w = x;
  99                 if (*w == x)
 100                         break;
 101         }
 102         return (w - base);
 103 }
 104
 105 /*
 106  * Generate an error packet of type error
 107  * in response to bad packet.
 108  */
 109
 110 ns_error(om, type, param)
 111         struct mbuf *om;
 112         int type;
 113 {
 114         register struct ns_epidp *ep;
 115         struct mbuf *m;
 116         struct idp *nip;
 117         register struct idp *oip = mtod(om, struct idp *);
 118         extern int idpcksum;
 119
 120         /*
 121          * If this packet was sent to the echo port,
 122          * and nobody was there, just echo it.
 123          * (Yes, this is a wart!)
 124          */
 125         if (type == NS_ERR_NOSOCK &&
 126             oip->idp_dna.x_port == htons(2) &&
 127             (type = ns_echo(om))==0)
 128                 return;
 129
 130 #ifdef NS_ERRPRINTFS
 131         if (ns_errprintfs)
 132                 printf("ns_err_error(%x, %d, %d)\n", oip, type, param);
 133 #endif
 134         /*
 135          * Don't Generate error packets in response to multicasts.
 136          */
 137         if (oip->idp_dna.x_host.c_host[0] & 1)
 138                 goto freeit;
 139
 140         ns_errstat.ns_es_error++;
 141         /*
 142          * Make sure that the old IDP packet had 30 bytes of data to return;
 143          * if not, don't bother.  Also don't EVER error if the old
 144          * packet protocol was NS_ERR.
 145          */
 146         if (oip->idp_len < sizeof(struct idp)) {
 147                 ns_errstat.ns_es_oldshort++;
 148                 goto freeit;
 149         }
 150         if (oip->idp_pt == NSPROTO_ERROR) {
 151                 ns_errstat.ns_es_oldns_err++;
 152                 goto freeit;
 153         }
 154
 155         /*
 156          * First, formulate ns_err message
 157          */
 158         m = m_gethdr(M_DONTWAIT, MT_HEADER);
 159         if (m == NULL)
 160                 goto freeit;
 161         m->m_len = sizeof(*ep);
 162         MH_ALIGN(m, m->m_len);
 163         ep = mtod(m, struct ns_epidp *);
 164         if ((u_int)type > NS_ERR_TOO_BIG)
 165                 panic("ns_err_error");
 166         ns_errstat.ns_es_outhist[ns_err_x(type)]++;
 167         ep->ns_ep_errp.ns_err_num = htons((u_short)type);
 168         ep->ns_ep_errp.ns_err_param = htons((u_short)param);
 169         bcopy((caddr_t)oip, (caddr_t)&ep->ns_ep_errp.ns_err_idp, 42);
 170         nip = &ep->ns_ep_idp;
 171         nip->idp_len = sizeof(*ep);
 172         nip->idp_len = htons((u_short)nip->idp_len);
 173         nip->idp_pt = NSPROTO_ERROR;
 174         nip->idp_tc = 0;
 175         nip->idp_dna = oip->idp_sna;
 176         nip->idp_sna = oip->idp_dna;
 177         if (idpcksum) {
 178                 nip->idp_sum = 0;
 179                 nip->idp_sum = ns_cksum(m, sizeof(*ep));
 180         } else
 181                 nip->idp_sum = 0xffff;
 182         (void) ns_output(m, (struct route *)0, 0);
 183
 184 freeit:
 185         m_freem(om);
 186 }
 187
 188 ns_printhost(p)
 189 register struct ns_addr *p;
 190 {
 191
 192         printf("<net:%x%x,host:%x%x%x,port:%x>",
 193                         p->x_net.s_net[0],
 194                         p->x_net.s_net[1],
 195                         p->x_host.s_host[0],
 196                         p->x_host.s_host[1],
 197                         p->x_host.s_host[2],
 198                         p->x_port);
 199
 200 }
 201
 202 /*
 203  * Process a received NS_ERR message.
 204  */
 205 ns_err_input(m)
 206         struct mbuf *m;
 207 {
 208         register struct ns_errp *ep;
 209         register struct ns_epidp *epidp = mtod(m, struct ns_epidp *);
 210         register int i;
 211         int type, code, param;
 212
 213         /*
 214          * Locate ns_err structure in mbuf, and check
 215          * that not corrupted and of at least minimum length.
 216          */
 217 #ifdef NS_ERRPRINTFS
 218         if (ns_errprintfs) {
 219                 printf("ns_err_input from ");
 220                 ns_printhost(&epidp->ns_ep_idp.idp_sna);
 221                 printf("len %d\n", ntohs(epidp->ns_ep_idp.idp_len));
 222         }
 223 #endif
 224         i = sizeof (struct ns_epidp);
 225         if (((m->m_flags & M_EXT) || m->m_len < i) &&
 226                 (m = m_pullup(m, i)) == 0)  {
 227                 ns_errstat.ns_es_tooshort++;
 228                 return;
 229         }
 230         ep = &(mtod(m, struct ns_epidp *)->ns_ep_errp);
 231         type = ntohs(ep->ns_err_num);
 232         param = ntohs(ep->ns_err_param);
 233         ns_errstat.ns_es_inhist[ns_err_x(type)]++;
 234
 235 #ifdef NS_ERRPRINTFS
 236         /*
 237          * Message type specific processing.
 238          */
 239         if (ns_errprintfs)
 240                 printf("ns_err_input, type %d param %d\n", type, param);
 241 #endif
 242         if (type >= NS_ERR_TOO_BIG) {
 243                 goto badcode;
 244         }
 245         ns_errstat.ns_es_outhist[ns_err_x(type)]++;
 246         switch (type) {
 247
 248         case NS_ERR_UNREACH_HOST:
 249                 code = PRC_UNREACH_NET;
 250                 goto deliver;
 251
 252         case NS_ERR_TOO_OLD:
 253                 code = PRC_TIMXCEED_INTRANS;
 254                 goto deliver;
 255
 256         case NS_ERR_TOO_BIG:
 257                 code = PRC_MSGSIZE;
 258                 goto deliver;
 259
 260         case NS_ERR_FULLUP:
 261                 code = PRC_QUENCH;
 262                 goto deliver;
 263
 264         case NS_ERR_NOSOCK:
 265                 code = PRC_UNREACH_PORT;
 266                 goto deliver;
 267
 268         case NS_ERR_UNSPEC_T:
 269         case NS_ERR_BADSUM_T:
 270         case NS_ERR_BADSUM:
 271         case NS_ERR_UNSPEC:
 272                 code = PRC_PARAMPROB;
 273                 goto deliver;
 274
 275         deliver:
 276                 /*
 277                  * Problem with datagram; advise higher level routines.
 278                  */
 279 #ifdef NS_ERRPRINTFS
 280                 if (ns_errprintfs)
 281                         printf("deliver to protocol %d\n",
 282                                        ep->ns_err_idp.idp_pt);
 283 #endif
 284                 switch(ep->ns_err_idp.idp_pt) {
 285                 case NSPROTO_SPP:
 286                         spp_ctlinput(code, (caddr_t)ep);
 287                         break;
 288
 289                 default:
 290                         idp_ctlinput(code, (caddr_t)ep);
 291                 }
 292
 293                 goto freeit;
 294
 295         default:
 296         badcode:
 297                 ns_errstat.ns_es_badcode++;
 298                 goto freeit;
 299
 300         }
 301 freeit:
 302         m_freem(m);
 303 }
 304
 305 #ifdef notdef
 306 u_long
 307 nstime()
 308 {
 309         int s = splclock();
 310         u_long t;
 311
 312         t = (time.tv_sec % (24*60*60)) * 1000 + time.tv_usec / 1000;
 313         splx(s);
 314         return (htonl(t));
 315 }
 316 #endif
 317
 318 ns_echo(m)
 319 struct mbuf *m;
 320 {
 321         register struct idp *idp = mtod(m, struct idp *);
 322         register struct echo {
 323             struct idp  ec_idp;
 324             u_short             ec_op; /* Operation, 1 = request, 2 = reply */
 325         } *ec = (struct echo *)idp;
 326         struct ns_addr temp;
 327
 328         if (idp->idp_pt!=NSPROTO_ECHO) return(NS_ERR_NOSOCK);
 329         if (ec->ec_op!=htons(1)) return(NS_ERR_UNSPEC);
 330
 331         ec->ec_op = htons(2);
 332
 333         temp = idp->idp_dna;
 334         idp->idp_dna = idp->idp_sna;
 335         idp->idp_sna = temp;
 336
 337         if (idp->idp_sum != 0xffff) {
 338                 idp->idp_sum = 0;
 339                 idp->idp_sum = ns_cksum(m,
 340                     (int)(((ntohs(idp->idp_len) - 1)|1)+1));
 341         }
 342         (void) ns_output(m, (struct route *)0, NS_FORWARDING);
 343         return(0);
 344 }