sys/netproto/ns/ns_error.c

   1 /*
   2  * Copyright (c) 1984, 1988, 1993
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. All advertising materials mentioning features or use of this software
  14  *    must display the following acknowledgement:
  15  *      This product includes software developed by the University of
  16  *      California, Berkeley and its contributors.
  17  * 4. Neither the name of the University nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  *
  33  *      @(#)ns_error.c  8.1 (Berkeley) 6/10/93
  34  * $FreeBSD: src/sys/netns/ns_error.c,v 1.9 1999/08/28 00:49:49 peter Exp $
  35  * $DragonFly: src/sys/netproto/ns/ns_error.c,v 1.11 2006/12/22 23:57:54 swildner Exp $
  36  */
  37
  38 #include <sys/param.h>
  39 #include <sys/systm.h>
  40 #include <sys/malloc.h>
  41 #include <sys/mbuf.h>
  42 #include <sys/protosw.h>
  43 #include <sys/socket.h>
  44 #include <sys/time.h>
  45 #include <sys/kernel.h>
  46
  47 #include <net/route.h>
  48
  49 #include "ns.h"
  50 #include "ns_pcb.h"
  51 #include "idp.h"
  52 #include "ns_error.h"
  53
  54 extern int idpcksum;            /* from ns_input.c */
  55 extern int idpchsum;            /* from ns_input.c */
  56 extern void spp_ctlinput( int, caddr_t);        /* from spp_usrreq.c XXX */
  57
  58 struct   ns_errstat ns_errstat;
  59
  60 #ifdef lint
  61 #define NS_ERRPRINTFS 1
  62 #endif
  63
  64 #ifdef NS_ERRPRINTFS
  65 /*
  66  * NS_ERR routines: error generation, receive packet processing, and
  67  * routines to turnaround packets back to the originator.
  68  */
  69 int     ns_errprintfs = 0;
  70 #endif
  71
  72 int
  73 ns_err_x(int c)
  74 {
  75         u_short *w, *lim, *base = ns_errstat.ns_es_codes;
  76         u_short x = c;
  77
  78         /*
  79          * zero is a legit error code, handle specially
  80          */
  81         if (x == 0)
  82                 return (0);
  83         lim = base + NS_ERR_MAX - 1;
  84         for (w = base + 1; w < lim; w++) {
  85                 if (*w == 0)
  86                         *w = x;
  87                 if (*w == x)
  88                         break;
  89         }
  90         return (w - base);
  91 }
  92
  93 /*
  94  * Generate an error packet of type error
  95  * in response to bad packet.
  96  */
  97
  98 void
  99 ns_error(struct mbuf *om, int type, int param)
 100 {
 101         struct ns_epidp *ep;
 102         struct mbuf *m;
 103         struct idp *nip;
 104         struct idp *oip = mtod(om, struct idp *);
 105
 106         /*
 107          * If this packet was sent to the echo port,
 108          * and nobody was there, just echo it.
 109          * (Yes, this is a wart!)
 110          */
 111         if (type == NS_ERR_NOSOCK &&
 112             oip->idp_dna.x_port == htons(2) &&
 113             (type = ns_echo(om))==0)
 114                 return;
 115
 116 #ifdef NS_ERRPRINTFS
 117         if (ns_errprintfs)
 118                 kprintf("ns_err_error(%x, %d, %d)\n", oip, type, param);
 119 #endif
 120         /*
 121          * Don't Generate error packets in response to multicasts.
 122          */
 123         if (oip->idp_dna.x_host.c_host[0] & 1)
 124                 goto freeit;
 125
 126         ns_errstat.ns_es_error++;
 127         /*
 128          * Make sure that the old IDP packet had 30 bytes of data to return;
 129          * if not, don't bother.  Also don't EVER error if the old
 130          * packet protocol was NS_ERR.
 131          */
 132         if (oip->idp_len < sizeof(struct idp)) {
 133                 ns_errstat.ns_es_oldshort++;
 134                 goto freeit;
 135         }
 136         if (oip->idp_pt == NSPROTO_ERROR) {
 137                 ns_errstat.ns_es_oldns_err++;
 138                 goto freeit;
 139         }
 140
 141         /*
 142          * First, formulate ns_err message
 143          */
 144         m = m_gethdr(MB_DONTWAIT, MT_HEADER);
 145         if (m == NULL)
 146                 goto freeit;
 147         m->m_len = sizeof(*ep);
 148         MH_ALIGN(m, m->m_len);
 149         ep = mtod(m, struct ns_epidp *);
 150         if ((u_int)type > NS_ERR_TOO_BIG)
 151                 panic("ns_err_error");
 152         ns_errstat.ns_es_outhist[ns_err_x(type)]++;
 153         ep->ns_ep_errp.ns_err_num = htons((u_short)type);
 154         ep->ns_ep_errp.ns_err_param = htons((u_short)param);
 155         bcopy((caddr_t)oip, (caddr_t)&ep->ns_ep_errp.ns_err_idp, 42);
 156         nip = &ep->ns_ep_idp;
 157         nip->idp_len = sizeof(*ep);
 158         nip->idp_len = htons((u_short)nip->idp_len);
 159         nip->idp_pt = NSPROTO_ERROR;
 160         nip->idp_tc = 0;
 161         nip->idp_dna = oip->idp_sna;
 162         nip->idp_sna = oip->idp_dna;
 163         if (idpcksum) {
 164                 nip->idp_sum = 0;
 165                 nip->idp_sum = ns_cksum(m, sizeof(*ep));
 166         } else
 167                 nip->idp_sum = 0xffff;
 168         ns_output(m, (struct route *)0, 0);
 169
 170 freeit:
 171         m_freem(om);
 172 }
 173
 174 void
 175 ns_printhost(struct ns_addr *p)
 176 {
 177
 178         kprintf("<net:%x%x,host:%x%x%x,port:%x>",
 179                         p->x_net.s_net[0],
 180                         p->x_net.s_net[1],
 181                         p->x_host.s_host[0],
 182                         p->x_host.s_host[1],
 183                         p->x_host.s_host[2],
 184                         p->x_port);
 185
 186 }
 187
 188 /*
 189  * Process a received NS_ERR message.
 190  */
 191 void
 192 ns_err_input(struct mbuf *m)
 193 {
 194         struct ns_errp *ep;
 195 #ifdef  NS_ERRPRINTFS
 196         struct ns_epidp *epidp = mtod(m, struct ns_epidp *);
 197 #endif
 198         int i;
 199         int type, code, param;
 200
 201         /*
 202          * Locate ns_err structure in mbuf, and check
 203          * that not corrupted and of at least minimum length.
 204          */
 205 #ifdef NS_ERRPRINTFS
 206         if (ns_errprintfs) {
 207                 kprintf("ns_err_input from ");
 208                 ns_printhost(&epidp->ns_ep_idp.idp_sna);
 209                 kprintf("len %d\n", ntohs(epidp->ns_ep_idp.idp_len));
 210         }
 211 #endif
 212         i = sizeof (struct ns_epidp);
 213         if (((m->m_flags & M_EXT) || m->m_len < i) &&
 214                 (m = m_pullup(m, i)) == 0)  {
 215                 ns_errstat.ns_es_tooshort++;
 216                 return;
 217         }
 218         ep = &(mtod(m, struct ns_epidp *)->ns_ep_errp);
 219         type = ntohs(ep->ns_err_num);
 220         param = ntohs(ep->ns_err_param);
 221         ns_errstat.ns_es_inhist[ns_err_x(type)]++;
 222
 223 #ifdef NS_ERRPRINTFS
 224         /*
 225          * Message type specific processing.
 226          */
 227         if (ns_errprintfs)
 228                 kprintf("ns_err_input, type %d param %d\n", type, param);
 229 #endif
 230         if (type >= NS_ERR_TOO_BIG) {
 231                 goto badcode;
 232         }
 233         ns_errstat.ns_es_outhist[ns_err_x(type)]++;
 234         switch (type) {
 235
 236         case NS_ERR_UNREACH_HOST:
 237                 code = PRC_UNREACH_NET;
 238                 goto deliver;
 239
 240         case NS_ERR_TOO_OLD:
 241                 code = PRC_TIMXCEED_INTRANS;
 242                 goto deliver;
 243
 244         case NS_ERR_TOO_BIG:
 245                 code = PRC_MSGSIZE;
 246                 goto deliver;
 247
 248         case NS_ERR_FULLUP:
 249                 code = PRC_QUENCH;
 250                 goto deliver;
 251
 252         case NS_ERR_NOSOCK:
 253                 code = PRC_UNREACH_PORT;
 254                 goto deliver;
 255
 256         case NS_ERR_UNSPEC_T:
 257         case NS_ERR_BADSUM_T:
 258         case NS_ERR_BADSUM:
 259         case NS_ERR_UNSPEC:
 260                 code = PRC_PARAMPROB;
 261                 goto deliver;
 262
 263         deliver:
 264                 /*
 265                  * Problem with datagram; advise higher level routines.
 266                  */
 267 #ifdef NS_ERRPRINTFS
 268                 if (ns_errprintfs)
 269                         kprintf("deliver to protocol %d\n",
 270                                        ep->ns_err_idp.idp_pt);
 271 #endif
 272                 switch(ep->ns_err_idp.idp_pt) {
 273                 case NSPROTO_SPP:
 274                         spp_ctlinput(code, (caddr_t)ep);
 275                         break;
 276
 277                 default:
 278                         idp_ctlinput(code, (caddr_t)ep);
 279                 }
 280
 281                 goto freeit;
 282
 283         default:
 284         badcode:
 285                 ns_errstat.ns_es_badcode++;
 286                 goto freeit;
 287
 288         }
 289 freeit:
 290         m_freem(m);
 291 }
 292
 293 int
 294 ns_echo(struct mbuf *m)
 295 {
 296         struct idp *idp = mtod(m, struct idp *);
 297         struct echo {
 298             struct idp  ec_idp;
 299             u_short             ec_op; /* Operation, 1 = request, 2 = reply */
 300         } *ec = (struct echo *)idp;
 301         struct ns_addr temp;
 302
 303         if (idp->idp_pt!=NSPROTO_ECHO) return(NS_ERR_NOSOCK);
 304         if (ec->ec_op!=htons(1)) return(NS_ERR_UNSPEC);
 305
 306         ec->ec_op = htons(2);
 307
 308         temp = idp->idp_dna;
 309         idp->idp_dna = idp->idp_sna;
 310         idp->idp_sna = temp;
 311
 312         if (idp->idp_sum != 0xffff) {
 313                 idp->idp_sum = 0;
 314                 idp->idp_sum = ns_cksum(m,
 315                     (int)(((ntohs(idp->idp_len) - 1)|1)+1));
 316         }
 317         ns_output(m, (struct route *)0, NS_FORWARDING);
 318         return(0);
 319 }