sys/netproto/ns/ns_input.c

   1 /*
   2  * Copyright (c) 1984, 1985, 1986, 1987, 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_input.c  8.1 (Berkeley) 6/10/93
  34  * $FreeBSD: src/sys/netns/ns_input.c,v 1.13 2000/02/13 03:32:04 peter Exp $
  35  * $DragonFly: src/sys/netproto/ns/ns_input.c,v 1.20 2007/05/23 08:57:08 dillon 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/domain.h>
  43 #include <sys/protosw.h>
  44 #include <sys/socket.h>
  45 #include <sys/socketvar.h>
  46 #include <sys/errno.h>
  47 #include <sys/time.h>
  48 #include <sys/kernel.h>
  49
  50 #include <sys/thread2.h>
  51 #include <sys/msgport2.h>
  52
  53 #include <net/if.h>
  54 #include <net/route.h>
  55 #include <net/raw_cb.h>
  56 #include <net/netisr.h>
  57
  58 #include "ns.h"
  59 #include "ns_if.h"
  60 #include "ns_pcb.h"
  61 #include "idp.h"
  62 #include "idp_var.h"
  63 #include "ns_error.h"
  64
  65 extern void     spp_input(struct mbuf *, ...); /* spp_usrreq.c XXX */
  66
  67 /*
  68  * NS initialization.
  69  */
  70 union ns_host   ns_thishost;
  71 union ns_host   ns_zerohost;
  72 union ns_host   ns_broadhost;
  73 union ns_net    ns_zeronet;
  74 union ns_net    ns_broadnet;
  75 struct sockaddr_ns ns_netmask, ns_hostmask;
  76
  77 static u_short allones[] = {-1, -1, -1};
  78
  79 struct nspcb nsrawpcb;
  80
  81 int     idpcksum = 1;
  82 long    ns_pexseq;
  83
  84 static void nsintr(struct netmsg *msg);
  85
  86 void
  87 ns_init(void)
  88 {
  89         ns_broadhost = * (union ns_host *) allones;
  90         ns_broadnet = * (union ns_net *) allones;
  91         nspcb.nsp_next = nspcb.nsp_prev = &nspcb;
  92         nsrawpcb.nsp_next = nsrawpcb.nsp_prev = &nsrawpcb;
  93         ns_pexseq = tick;
  94         ns_netmask.sns_len = 6;
  95         ns_netmask.sns_addr.x_net = ns_broadnet;
  96         ns_hostmask.sns_len = 12;
  97         ns_hostmask.sns_addr.x_net = ns_broadnet;
  98         ns_hostmask.sns_addr.x_host = ns_broadhost;
  99         netisr_register(NETISR_NS, cpu0_portfn, nsintr);
 100 }
 101
 102 /*
 103  * Idp input routine.  Pass to next level.
 104  */
 105 int nsintr_getpck = 0;
 106 int nsintr_swtch = 0;
 107
 108 static void
 109 nsintr(struct netmsg *msg)
 110 {
 111         struct mbuf *m = ((struct netmsg_packet *)msg)->nm_packet;
 112         struct idp *idp;
 113         struct nspcb *nsp;
 114         int i;
 115         int len, error;
 116         char oddpacketp;
 117
 118         /*
 119          * Get IDP header in first mbuf.
 120          */
 121         nsintr_getpck++;
 122         if ((m->m_flags & M_EXT || m->m_len < sizeof (struct idp)) &&
 123             (m = m_pullup(m, sizeof (struct idp))) == 0) {
 124                 idpstat.idps_toosmall++;
 125                 goto out;
 126         }
 127
 128         /*
 129          * Give any raw listeners a crack at the packet
 130          */
 131         for (nsp = nsrawpcb.nsp_next; nsp != &nsrawpcb; nsp = nsp->nsp_next) {
 132                 struct mbuf *m1 = m_copy(m, 0, (int)M_COPYALL);
 133                 if (m1) idp_input(m1, nsp);
 134         }
 135
 136         idp = mtod(m, struct idp *);
 137         len = ntohs(idp->idp_len);
 138         if ((oddpacketp = (len & 1))) {
 139                 len++;          /* If this packet is of odd length,
 140                                    preserve garbage byte for checksum */
 141         }
 142
 143         /*
 144          * Check that the amount of data in the buffers
 145          * is as at least much as the IDP header would have us expect.
 146          * Trim mbufs if longer than we expect.
 147          * Drop packet if shorter than we expect.
 148          */
 149         if (m->m_pkthdr.len < len) {
 150                 idpstat.idps_tooshort++;
 151                 goto bad;
 152         }
 153         if (m->m_pkthdr.len > len) {
 154                 if (m->m_len == m->m_pkthdr.len) {
 155                         m->m_len = len;
 156                         m->m_pkthdr.len = len;
 157                 } else
 158                         m_adj(m, len - m->m_pkthdr.len);
 159         }
 160         if (idpcksum && ((i = idp->idp_sum)!=0xffff)) {
 161                 idp->idp_sum = 0;
 162                 if (i != (idp->idp_sum = ns_cksum(m, len))) {
 163                         idpstat.idps_badsum++;
 164                         idp->idp_sum = i;
 165                         if (ns_hosteqnh(ns_thishost, idp->idp_dna.x_host))
 166                                 error = NS_ERR_BADSUM;
 167                         else
 168                                 error = NS_ERR_BADSUM_T;
 169                         ns_error(m, error, 0);
 170                         goto out;
 171                 }
 172         }
 173         /*
 174          * Is this a directed broadcast?
 175          */
 176         if (ns_hosteqnh(ns_broadhost,idp->idp_dna.x_host)) {
 177                 if ((!ns_neteq(idp->idp_dna, idp->idp_sna)) &&
 178                     (!ns_neteqnn(idp->idp_dna.x_net, ns_broadnet)) &&
 179                     (!ns_neteqnn(idp->idp_sna.x_net, ns_zeronet)) &&
 180                     (!ns_neteqnn(idp->idp_dna.x_net, ns_zeronet)) ) {
 181                         /*
 182                          * Look to see if I need to eat this packet.
 183                          * Algorithm is to forward all young packets
 184                          * and prematurely age any packets which will
 185                          * by physically broadcasted.
 186                          * Any very old packets eaten without forwarding
 187                          * would die anyway.
 188                          *
 189                          * Suggestion of Bill Nesheim, Cornell U.
 190                          */
 191                         if (idp->idp_tc < NS_MAXHOPS) {
 192                                 idp_forward(m);
 193                                 goto out;
 194                         }
 195                 }
 196         /*
 197          * Is this our packet? If not, forward.
 198          */
 199         } else if (!ns_hosteqnh(ns_thishost,idp->idp_dna.x_host)) {
 200                 idp_forward(m);
 201                 goto out;
 202         }
 203         /*
 204          * Locate pcb for datagram.
 205          */
 206         nsp = ns_pcblookup(&idp->idp_sna, idp->idp_dna.x_port, NS_WILDCARD);
 207         /*
 208          * Switch out to protocol's input routine.
 209          */
 210         nsintr_swtch++;
 211         if (nsp) {
 212                 if (oddpacketp) {
 213                         m_adj(m, -1);
 214                 }
 215                 if ((nsp->nsp_flags & NSP_ALL_PACKETS)==0)
 216                         switch (idp->idp_pt) {
 217
 218                             case NSPROTO_SPP:
 219                                     spp_input(m, nsp);
 220                                     goto out;
 221
 222                             case NSPROTO_ERROR:
 223                                     ns_err_input(m);
 224                                     goto out;
 225                         }
 226                 idp_input(m, nsp);
 227         } else {
 228                 ns_error(m, NS_ERR_NOSOCK, 0);
 229         }
 230         goto out;
 231
 232 bad:
 233         m_freem(m);
 234 out:
 235         ;
 236         /* msg was embedded in the mbuf, do not reply! */
 237 }
 238
 239 u_char nsctlerrmap[PRC_NCMDS] = {
 240         ECONNABORTED,   ECONNABORTED,   0,              0,
 241         0,              0,              EHOSTDOWN,      EHOSTUNREACH,
 242         ENETUNREACH,    EHOSTUNREACH,   ECONNREFUSED,   ECONNREFUSED,
 243         EMSGSIZE,       0,              0,              0,
 244         0,              0,              0,              0
 245 };
 246
 247 int idp_donosocks = 1;
 248
 249 void
 250 idp_ctlinput(int cmd, caddr_t arg)
 251 {
 252         struct ns_addr *ns;
 253         struct nspcb *nsp;
 254         struct ns_errp *errp = (struct ns_errp *)arg;   /* XXX */
 255         int type;
 256
 257         if (cmd < 0 || cmd > PRC_NCMDS)
 258                 return;
 259         if (nsctlerrmap[cmd] == 0)
 260                 return;         /* XXX */
 261         type = NS_ERR_UNREACH_HOST;
 262         switch (cmd) {
 263                 struct sockaddr_ns *sns;
 264
 265         case PRC_IFDOWN:
 266         case PRC_HOSTDEAD:
 267         case PRC_HOSTUNREACH:
 268                 sns = (struct sockaddr_ns *)arg;
 269                 if (sns->sns_family != AF_NS)
 270                         return;
 271                 ns = &sns->sns_addr;
 272                 break;
 273
 274         default:
 275                 errp = (struct ns_errp *)arg;
 276                 ns = &errp->ns_err_idp.idp_dna;
 277                 type = errp->ns_err_num;
 278                 type = ntohs((u_short)type);
 279         }
 280         switch (type) {
 281
 282         case NS_ERR_UNREACH_HOST:
 283                 ns_pcbnotify(ns, (int)nsctlerrmap[cmd], idp_abort, (long)0);
 284                 break;
 285
 286         case NS_ERR_NOSOCK:
 287                 nsp = ns_pcblookup(ns, errp->ns_err_idp.idp_sna.x_port,
 288                         NS_WILDCARD);
 289                 if(nsp && idp_donosocks && ! ns_nullhost(nsp->nsp_faddr))
 290                         idp_drop(nsp, (int)nsctlerrmap[cmd]);
 291         }
 292 }
 293
 294 int     idpprintfs = 0;
 295 int     idpforwarding = 1;
 296 /*
 297  * Forward a packet.  If some error occurs return the sender
 298  * an error packet.  Note we can't always generate a meaningful
 299  * error message because the NS errors don't have a large enough repetoire
 300  * of codes and types.
 301  */
 302 struct route idp_droute;
 303 struct route idp_sroute;
 304
 305 void
 306 idp_forward(struct mbuf *m)
 307 {
 308         struct idp *idp = mtod(m, struct idp *);
 309         int error, type, code;
 310         struct mbuf *mcopy = NULL;
 311         int agedelta = 1;
 312         int flags = NS_FORWARDING;
 313         int ok_there = 0;
 314         int ok_back = 0;
 315
 316         if (idpprintfs) {
 317                 kprintf("forward: src ");
 318                 ns_printhost(&idp->idp_sna);
 319                 kprintf(", dst ");
 320                 ns_printhost(&idp->idp_dna);
 321                 kprintf("hop count %d\n", idp->idp_tc);
 322         }
 323         if (idpforwarding == 0) {
 324                 /* can't tell difference between net and host */
 325                 type = NS_ERR_UNREACH_HOST, code = 0;
 326                 goto senderror;
 327         }
 328         idp->idp_tc++;
 329         if (idp->idp_tc > NS_MAXHOPS) {
 330                 type = NS_ERR_TOO_OLD, code = 0;
 331                 goto senderror;
 332         }
 333         /*
 334          * Save at most 42 bytes of the packet in case
 335          * we need to generate an NS error message to the src.
 336          */
 337         mcopy = m_copy(m, 0, imin((int)ntohs(idp->idp_len), 42));
 338
 339         if ((ok_there = idp_do_route(&idp->idp_dna,&idp_droute))==0) {
 340                 type = NS_ERR_UNREACH_HOST, code = 0;
 341                 goto senderror;
 342         }
 343         /*
 344          * Here we think about  forwarding  broadcast packets,
 345          * so we try to insure that it doesn't go back out
 346          * on the interface it came in on.  Also, if we
 347          * are going to physically broadcast this, let us
 348          * age the packet so we can eat it safely the second time around.
 349          */
 350         if (idp->idp_dna.x_host.c_host[0] & 0x1) {
 351                 struct ns_ifaddr *ia = ns_iaonnetof(&idp->idp_dna);
 352                 struct ifnet *ifp;
 353                 if (ia) {
 354                         /* I'm gonna hafta eat this packet */
 355                         agedelta += NS_MAXHOPS - idp->idp_tc;
 356                         idp->idp_tc = NS_MAXHOPS;
 357                 }
 358                 if ((ok_back = idp_do_route(&idp->idp_sna,&idp_sroute))==0) {
 359                         /* error = ENETUNREACH; He'll never get it! */
 360                         m_freem(m);
 361                         goto cleanup;
 362                 }
 363                 if (idp_droute.ro_rt &&
 364                     (ifp=idp_droute.ro_rt->rt_ifp) &&
 365                     idp_sroute.ro_rt &&
 366                     (ifp!=idp_sroute.ro_rt->rt_ifp)) {
 367                         flags |= NS_ALLOWBROADCAST;
 368                 } else {
 369                         type = NS_ERR_UNREACH_HOST, code = 0;
 370                         goto senderror;
 371                 }
 372         }
 373         /* need to adjust checksum */
 374         if (idp->idp_sum!=0xffff) {
 375                 union bytes {
 376                         u_char c[4];
 377                         u_short s[2];
 378                         long l;
 379                 } x;
 380                 int shift;
 381                 x.l = 0; x.c[0] = agedelta;
 382                 shift = (((((int)ntohs(idp->idp_len))+1)>>1)-2) & 0xf;
 383                 x.l = idp->idp_sum + (x.s[0] << shift);
 384                 x.l = x.s[0] + x.s[1];
 385                 x.l = x.s[0] + x.s[1];
 386                 if (x.l==0xffff) idp->idp_sum = 0; else idp->idp_sum = x.l;
 387         }
 388         if ((error = ns_output(m, &idp_droute, flags)) &&
 389             (mcopy!=NULL)) {
 390                 idp = mtod(mcopy, struct idp *);
 391                 type = NS_ERR_UNSPEC_T, code = 0;
 392                 switch (error) {
 393
 394                 case ENETUNREACH:
 395                 case EHOSTDOWN:
 396                 case EHOSTUNREACH:
 397                 case ENETDOWN:
 398                 case EPERM:
 399                         type = NS_ERR_UNREACH_HOST;
 400                         break;
 401
 402                 case EMSGSIZE:
 403                         type = NS_ERR_TOO_BIG;
 404                         code = 576; /* too hard to figure out mtu here */
 405                         break;
 406
 407                 case ENOBUFS:
 408                         type = NS_ERR_UNSPEC_T;
 409                         break;
 410                 }
 411                 mcopy = NULL;
 412         senderror:
 413                 ns_error(m, type, code);
 414         }
 415 cleanup:
 416         if (ok_there)
 417                 idp_undo_route(&idp_droute);
 418         if (ok_back)
 419                 idp_undo_route(&idp_sroute);
 420         if (mcopy != NULL)
 421                 m_freem(mcopy);
 422 }
 423
 424 int
 425 idp_do_route(struct ns_addr *src, struct route *ro)
 426 {
 427
 428         struct sockaddr_ns *dst;
 429
 430         bzero((caddr_t)ro, sizeof (*ro));
 431         dst = (struct sockaddr_ns *)&ro->ro_dst;
 432
 433         dst->sns_len = sizeof(*dst);
 434         dst->sns_family = AF_NS;
 435         dst->sns_addr = *src;
 436         dst->sns_addr.x_port = 0;
 437         rtalloc(ro);
 438         if (ro->ro_rt == 0 || ro->ro_rt->rt_ifp == 0) {
 439                 return (0);
 440         }
 441         ro->ro_rt->rt_use++;
 442         return (1);
 443 }
 444
 445 void
 446 idp_undo_route(struct route *ro)
 447 {
 448         if (ro->ro_rt) {RTFREE(ro->ro_rt);}
 449 }
 450
 451 void
 452 ns_watch_output(struct mbuf *m, struct ifnet *ifp)
 453 {
 454         struct nspcb *nsp;
 455         struct ifaddr *ifa;
 456         /*
 457          * Give any raw listeners a crack at the packet
 458          */
 459         for (nsp = nsrawpcb.nsp_next; nsp != &nsrawpcb; nsp = nsp->nsp_next) {
 460                 struct mbuf *m0 = m_copy(m, 0, (int)M_COPYALL);
 461                 if (m0) {
 462                         struct idp *idp;
 463
 464                         M_PREPEND(m0, sizeof (*idp), MB_DONTWAIT);
 465                         if (m0 == NULL)
 466                                 continue;
 467                         idp = mtod(m0, struct idp *);
 468                         idp->idp_sna.x_net = ns_zeronet;
 469                         idp->idp_sna.x_host = ns_thishost;
 470                         if (ifp && (ifp->if_flags & IFF_POINTOPOINT))
 471                                 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link)
 472                                 if (ifa->ifa_addr->sa_family==AF_NS) {
 473                                     idp->idp_sna = IA_SNS(ifa)->sns_addr;
 474                                     break;
 475                                 }
 476                         idp->idp_len = ntohl(m0->m_pkthdr.len);
 477                         idp_input(m0, nsp);
 478                 }
 479         }
 480 }