release/src/router/pppd/modules/if_ppp.c

   1 /*
   2  * if_ppp.c - a network interface connected to a STREAMS module.
   3  *
   4  * Copyright (c) 1994 Paul Mackerras. All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  *
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  *
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in
  15  *    the documentation and/or other materials provided with the
  16  *    distribution.
  17  *
  18  * 3. The name(s) of the authors of this software must not be used to
  19  *    endorse or promote products derived from this software without
  20  *    prior written permission.
  21  *
  22  * 4. Redistributions of any form whatsoever must retain the following
  23  *    acknowledgment:
  24  *    "This product includes software developed by Paul Mackerras
  25  *     <paulus@samba.org>".
  26  *
  27  * THE AUTHORS OF THIS SOFTWARE DISCLAIM ALL WARRANTIES WITH REGARD TO
  28  * THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
  29  * AND FITNESS, IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY
  30  * SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  31  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN
  32  * AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
  33  * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  34  *
  35  * $Id: if_ppp.c,v 1.18 2002/12/06 09:49:15 paulus Exp $
  36  */
  37
  38 /*
  39  * This file is used under SunOS 4 and Digital UNIX.
  40  *
  41  * This file provides the glue between PPP and IP.
  42  */
  43
  44 #define INET    1
  45
  46 #include <sys/types.h>
  47 #include <sys/param.h>
  48 #include <sys/errno.h>
  49 #include <sys/mbuf.h>
  50 #include <sys/socket.h>
  51 #include <net/if.h>
  52 #include <net/netisr.h>
  53 #include <net/ppp_defs.h>
  54 #include <net/pppio.h>
  55 #include <netinet/in.h>
  56 #include <netinet/in_var.h>
  57 #ifdef __osf__
  58 #include <sys/ioctl.h>
  59 #include <net/if_types.h>
  60 #else
  61 #include <sys/sockio.h>
  62 #endif
  63 #include "ppp_mod.h"
  64
  65 #include <sys/stream.h>
  66
  67 #ifdef SNIT_SUPPORT
  68 #include <sys/time.h>
  69 #include <net/nit_if.h>
  70 #include <netinet/if_ether.h>
  71 #endif
  72
  73 #ifdef __osf__
  74 #define SIOCSIFMTU SIOCSIPMTU
  75 #define SIOCGIFMTU SIOCRIPMTU
  76 #define IFA_ADDR(ifa)   (*(ifa)->ifa_addr)
  77 #else
  78 #define IFA_ADDR(ifa)   ((ifa)->ifa_addr)
  79 #endif
  80
  81 #define ifr_mtu         ifr_metric
  82
  83 static int if_ppp_open __P((queue_t *, int, int, int));
  84 static int if_ppp_close __P((queue_t *, int));
  85 static int if_ppp_wput __P((queue_t *, mblk_t *));
  86 static int if_ppp_rput __P((queue_t *, mblk_t *));
  87
  88 #define PPP_IF_ID 0x8021
  89 static struct module_info minfo = {
  90     PPP_IF_ID, "if_ppp", 0, INFPSZ, 4096, 128
  91 };
  92
  93 static struct qinit rinit = {
  94     if_ppp_rput, NULL, if_ppp_open, if_ppp_close, NULL, &minfo, NULL
  95 };
  96
  97 static struct qinit winit = {
  98     if_ppp_wput, NULL, NULL, NULL, NULL, &minfo, NULL
  99 };
 100
 101 struct streamtab if_pppinfo = {
 102     &rinit, &winit, NULL, NULL
 103 };
 104
 105 typedef struct if_ppp_state {
 106     int unit;
 107     queue_t *q;
 108     int flags;
 109 } if_ppp_t;
 110
 111 /* Values for flags */
 112 #define DBGLOG          1
 113
 114 static int if_ppp_count;        /* Number of currently-active streams */
 115
 116 static int ppp_nalloc;          /* Number of elements of ifs and states */
 117 static struct ifnet **ifs;      /* Array of pointers to interface structs */
 118 static if_ppp_t **states;       /* Array of pointers to state structs */
 119
 120 static int if_ppp_output __P((struct ifnet *, struct mbuf *,
 121                               struct sockaddr *));
 122 static int if_ppp_ioctl __P((struct ifnet *, u_int, caddr_t));
 123 static struct mbuf *make_mbufs __P((mblk_t *, int));
 124 static mblk_t *make_message __P((struct mbuf *, int));
 125
 126 #ifdef SNIT_SUPPORT
 127 /* Fake ether header for SNIT */
 128 static struct ether_header snit_ehdr = {{0}, {0}, ETHERTYPE_IP};
 129 #endif
 130
 131 #ifndef __osf__
 132 static void ppp_if_detach __P((struct ifnet *));
 133
 134 /*
 135  * Detach all the interfaces before unloading.
 136  * Not sure this works.
 137  */
 138 int
 139 if_ppp_unload()
 140 {
 141     int i;
 142
 143     if (if_ppp_count > 0)
 144         return EBUSY;
 145     for (i = 0; i < ppp_nalloc; ++i)
 146         if (ifs[i] != 0)
 147             ppp_if_detach(ifs[i]);
 148     if (ifs) {
 149         FREE(ifs, ppp_nalloc * sizeof (struct ifnet *));
 150         FREE(states, ppp_nalloc * sizeof (struct if_ppp_t *));
 151     }
 152     ppp_nalloc = 0;
 153     return 0;
 154 }
 155 #endif /* __osf__ */
 156
 157 /*
 158  * STREAMS module entry points.
 159  */
 160 static int
 161 if_ppp_open(q, dev, flag, sflag)
 162     queue_t *q;
 163     int dev;
 164     int flag, sflag;
 165 {
 166     if_ppp_t *sp;
 167
 168     if (q->q_ptr == 0) {
 169         sp = (if_ppp_t *) ALLOC_SLEEP(sizeof (if_ppp_t));
 170         if (sp == 0)
 171             return OPENFAIL;
 172         bzero(sp, sizeof (if_ppp_t));
 173         q->q_ptr = (caddr_t) sp;
 174         WR(q)->q_ptr = (caddr_t) sp;
 175         sp->unit = -1;          /* no interface unit attached at present */
 176         sp->q = WR(q);
 177         sp->flags = 0;
 178         ++if_ppp_count;
 179     }
 180     return 0;
 181 }
 182
 183 static int
 184 if_ppp_close(q, flag)
 185     queue_t *q;
 186     int flag;
 187 {
 188     if_ppp_t *sp;
 189     struct ifnet *ifp;
 190
 191     sp = (if_ppp_t *) q->q_ptr;
 192     if (sp != 0) {
 193         if (sp->flags & DBGLOG)
 194             printf("if_ppp closed, q=%x sp=%x\n", q, sp);
 195         if (sp->unit >= 0) {
 196             if (sp->unit < ppp_nalloc) {
 197                 states[sp->unit] = 0;
 198                 ifp = ifs[sp->unit];
 199                 if (ifp != 0)
 200                     ifp->if_flags &= ~(IFF_UP | IFF_RUNNING);
 201 #ifdef DEBUG
 202             } else {
 203                 printf("if_ppp: unit %d nonexistent!\n", sp->unit);
 204 #endif
 205             }
 206         }
 207         FREE(sp, sizeof (if_ppp_t));
 208         --if_ppp_count;
 209     }
 210     return 0;
 211 }
 212
 213 static int
 214 if_ppp_wput(q, mp)
 215     queue_t *q;
 216     mblk_t *mp;
 217 {
 218     if_ppp_t *sp;
 219     struct iocblk *iop;
 220     int error, unit;
 221     struct ifnet *ifp;
 222
 223     sp = (if_ppp_t *) q->q_ptr;
 224     switch (mp->b_datap->db_type) {
 225     case M_DATA:
 226         /*
 227          * Now why would we be getting data coming in here??
 228          */
 229         if (sp->flags & DBGLOG)
 230             printf("if_ppp: got M_DATA len=%d\n", msgdsize(mp));
 231         freemsg(mp);
 232         break;
 233
 234     case M_IOCTL:
 235         iop = (struct iocblk *) mp->b_rptr;
 236         error = EINVAL;
 237
 238         if (sp->flags & DBGLOG)
 239             printf("if_ppp: got ioctl cmd=%x count=%d\n",
 240                    iop->ioc_cmd, iop->ioc_count);
 241
 242         switch (iop->ioc_cmd) {
 243         case PPPIO_NEWPPA:              /* well almost */
 244             if (iop->ioc_count != sizeof(int) || sp->unit >= 0)
 245                 break;
 246             if ((error = NOTSUSER()) != 0)
 247                 break;
 248             unit = *(int *)mp->b_cont->b_rptr;
 249
 250             /* Check that this unit isn't already in use */
 251             if (unit < ppp_nalloc && states[unit] != 0) {
 252                 error = EADDRINUSE;
 253                 break;
 254             }
 255
 256             /* Extend ifs and states arrays if necessary. */
 257             error = ENOSR;
 258             if (unit >= ppp_nalloc) {
 259                 int newn;
 260                 struct ifnet **newifs;
 261                 if_ppp_t **newstates;
 262
 263                 newn = unit + 4;
 264                 if (sp->flags & DBGLOG)
 265                     printf("if_ppp: extending ifs to %d\n", newn);
 266                 newifs = (struct ifnet **)
 267                     ALLOC_NOSLEEP(newn * sizeof (struct ifnet *));
 268                 if (newifs == 0)
 269                     break;
 270                 bzero(newifs, newn * sizeof (struct ifnet *));
 271                 newstates = (if_ppp_t **)
 272                     ALLOC_NOSLEEP(newn * sizeof (struct if_ppp_t *));
 273                 if (newstates == 0) {
 274                     FREE(newifs, newn * sizeof (struct ifnet *));
 275                     break;
 276                 }
 277                 bzero(newstates, newn * sizeof (struct if_ppp_t *));
 278                 bcopy(ifs, newifs, ppp_nalloc * sizeof(struct ifnet *));
 279                 bcopy(states, newstates, ppp_nalloc * sizeof(if_ppp_t *));
 280                 if (ifs) {
 281                     FREE(ifs, ppp_nalloc * sizeof(struct ifnet *));
 282                     FREE(states, ppp_nalloc * sizeof(if_ppp_t *));
 283                 }
 284                 ifs = newifs;
 285                 states = newstates;
 286                 ppp_nalloc = newn;
 287             }
 288
 289             /* Allocate a new ifnet struct if necessary. */
 290             ifp = ifs[unit];
 291             if (ifp == 0) {
 292                 ifp = (struct ifnet *) ALLOC_NOSLEEP(sizeof (struct ifnet));
 293                 if (ifp == 0)
 294                     break;
 295                 bzero(ifp, sizeof (struct ifnet));
 296                 ifs[unit] = ifp;
 297                 ifp->if_name = "ppp";
 298                 ifp->if_unit = unit;
 299                 ifp->if_mtu = PPP_MTU;
 300                 ifp->if_flags = IFF_POINTOPOINT | IFF_RUNNING;
 301 #ifndef __osf__
 302 #ifdef IFF_MULTICAST
 303                 ifp->if_flags |= IFF_MULTICAST;
 304 #endif
 305 #endif /* __osf__ */
 306                 ifp->if_output = if_ppp_output;
 307 #ifdef __osf__
 308                 ifp->if_version = "Point-to-Point Protocol, version 2.3.11";
 309                 ifp->if_mediamtu = PPP_MTU;
 310                 ifp->if_type = IFT_PPP;
 311                 ifp->if_hdrlen = PPP_HDRLEN;
 312                 ifp->if_addrlen = 0;
 313                 ifp->if_flags |= IFF_NOARP | IFF_SIMPLEX | IFF_NOTRAILERS;
 314 #ifdef IFF_VAR_MTU
 315                 ifp->if_flags |= IFF_VAR_MTU;
 316 #endif
 317 #ifdef NETMASTERCPU
 318                 ifp->if_affinity = NETMASTERCPU;
 319 #endif
 320 #endif
 321                 ifp->if_ioctl = if_ppp_ioctl;
 322                 ifp->if_snd.ifq_maxlen = IFQ_MAXLEN;
 323                 if_attach(ifp);
 324                 if (sp->flags & DBGLOG)
 325                     printf("if_ppp: created unit %d\n", unit);
 326             } else {
 327                 ifp->if_mtu = PPP_MTU;
 328                 ifp->if_flags |= IFF_RUNNING;
 329             }
 330
 331             states[unit] = sp;
 332             sp->unit = unit;
 333
 334             error = 0;
 335             iop->ioc_count = 0;
 336             if (sp->flags & DBGLOG)
 337                 printf("if_ppp: attached unit %d, sp=%x q=%x\n", unit,
 338                        sp, sp->q);
 339             break;
 340
 341         case PPPIO_DEBUG:
 342             error = -1;
 343             if (iop->ioc_count == sizeof(int)) {
 344                 if (*(int *)mp->b_cont->b_rptr == PPPDBG_LOG + PPPDBG_IF) {
 345                     printf("if_ppp: debug log enabled, q=%x sp=%x\n", q, sp);
 346                     sp->flags |= DBGLOG;
 347                     error = 0;
 348                     iop->ioc_count = 0;
 349                 }
 350             }
 351             break;
 352
 353         default:
 354             error = -1;
 355             break;
 356         }
 357
 358         if (sp->flags & DBGLOG)
 359             printf("if_ppp: ioctl result %d\n", error);
 360         if (error < 0)
 361             putnext(q, mp);
 362         else if (error == 0) {
 363             mp->b_datap->db_type = M_IOCACK;
 364             qreply(q, mp);
 365         } else {
 366             mp->b_datap->db_type = M_IOCNAK;
 367             iop->ioc_count = 0;
 368             iop->ioc_error = error;
 369             qreply(q, mp);
 370         }
 371         break;
 372
 373     default:
 374         putnext(q, mp);
 375     }
 376     return 0;
 377 }
 378
 379 static int
 380 if_ppp_rput(q, mp)
 381     queue_t *q;
 382     mblk_t *mp;
 383 {
 384     if_ppp_t *sp;
 385     int proto, s;
 386     struct mbuf *mb;
 387     struct ifqueue *inq;
 388     struct ifnet *ifp;
 389     int len;
 390
 391     sp = (if_ppp_t *) q->q_ptr;
 392     switch (mp->b_datap->db_type) {
 393     case M_DATA:
 394         /*
 395          * Convert the message into an mbuf chain
 396          * and inject it into the network code.
 397          */
 398         if (sp->flags & DBGLOG)
 399             printf("if_ppp: rput pkt len %d data %x %x %x %x %x %x %x %x\n",
 400                    msgdsize(mp), mp->b_rptr[0], mp->b_rptr[1], mp->b_rptr[2],
 401                    mp->b_rptr[3], mp->b_rptr[4], mp->b_rptr[5], mp->b_rptr[6],
 402                    mp->b_rptr[7]);
 403
 404         if (sp->unit < 0) {
 405             freemsg(mp);
 406             break;
 407         }
 408         if (sp->unit >= ppp_nalloc || (ifp = ifs[sp->unit]) == 0) {
 409 #ifdef DEBUG
 410             printf("if_ppp: no unit %d!\n", sp->unit);
 411 #endif
 412             freemsg(mp);
 413             break;
 414         }
 415
 416         if ((ifp->if_flags & IFF_UP) == 0) {
 417             freemsg(mp);
 418             break;
 419         }
 420         ++ifp->if_ipackets;
 421
 422         proto = PPP_PROTOCOL(mp->b_rptr);
 423         adjmsg(mp, PPP_HDRLEN);
 424         len = msgdsize(mp);
 425         mb = make_mbufs(mp, sizeof(struct ifnet *));
 426         freemsg(mp);
 427         if (mb == NULL) {
 428             if (sp->flags & DBGLOG)
 429                 printf("if_ppp%d: make_mbufs failed\n", ifp->if_unit);
 430             ++ifp->if_ierrors;
 431             break;
 432         }
 433
 434 #ifdef SNIT_SUPPORT
 435         if (proto == PPP_IP && (ifp->if_flags & IFF_PROMISC)) {
 436             struct nit_if nif;
 437
 438             nif.nif_header = (caddr_t) &snit_ehdr;
 439             nif.nif_hdrlen = sizeof(snit_ehdr);
 440             nif.nif_bodylen = len;
 441             nif.nif_promisc = 0;
 442             snit_intr(ifp, mb, &nif);
 443         }
 444 #endif
 445
 446 /*
 447  * For Digital UNIX, there's space set aside in the header mbuf
 448  * for the interface info.
 449  *
 450  * For Sun it's smuggled around via a pointer at the front of the mbuf.
 451  */
 452 #ifdef __osf__
 453         mb->m_pkthdr.rcvif = ifp;
 454         mb->m_pkthdr.len = len;
 455 #else
 456         mb->m_off -= sizeof(struct ifnet *);
 457         mb->m_len += sizeof(struct ifnet *);
 458         *mtod(mb, struct ifnet **) = ifp;
 459 #endif
 460
 461         inq = 0;
 462         switch (proto) {
 463         case PPP_IP:
 464             inq = &ipintrq;
 465             schednetisr(NETISR_IP);
 466         }
 467
 468         if (inq != 0) {
 469             s = splhigh();
 470             if (IF_QFULL(inq)) {
 471                 IF_DROP(inq);
 472                 ++ifp->if_ierrors;
 473                 if (sp->flags & DBGLOG)
 474                     printf("if_ppp: inq full, proto=%x\n", proto);
 475                 m_freem(mb);
 476             } else {
 477                 IF_ENQUEUE(inq, mb);
 478             }
 479             splx(s);
 480         } else {
 481             if (sp->flags & DBGLOG)
 482                 printf("if_ppp%d: proto=%x?\n", ifp->if_unit, proto);
 483             ++ifp->if_ierrors;
 484             m_freem(mb);
 485         }
 486         break;
 487
 488     default:
 489         putnext(q, mp);
 490     }
 491     return 0;
 492 }
 493
 494 /*
 495  * Network code wants to output a packet.
 496  * Turn it into a STREAMS message and send it down.
 497  */
 498 static int
 499 if_ppp_output(ifp, m0, dst)
 500     struct ifnet *ifp;
 501     struct mbuf *m0;
 502     struct sockaddr *dst;
 503 {
 504     mblk_t *mp;
 505     int proto, s;
 506     if_ppp_t *sp;
 507     u_char *p;
 508
 509     if ((ifp->if_flags & IFF_UP) == 0) {
 510         m_freem(m0);
 511         return ENETDOWN;
 512     }
 513
 514     if ((unsigned)ifp->if_unit >= ppp_nalloc) {
 515 #ifdef DEBUG
 516         printf("if_ppp_output: unit %d?\n", ifp->if_unit);
 517 #endif
 518         m_freem(m0);
 519         return EINVAL;
 520     }
 521     sp = states[ifp->if_unit];
 522     if (sp == 0) {
 523 #ifdef DEBUG
 524         printf("if_ppp_output: no queue?\n");
 525 #endif
 526         m_freem(m0);
 527         return ENETDOWN;
 528     }
 529
 530     if (sp->flags & DBGLOG) {
 531         p = mtod(m0, u_char *);
 532         printf("if_ppp_output%d: af=%d data=%x %x %x %x %x %x %x %x q=%x\n",
 533                ifp->if_unit, dst->sa_family, p[0], p[1], p[2], p[3], p[4],
 534                p[5], p[6], p[7], sp->q);
 535     }
 536
 537     switch (dst->sa_family) {
 538     case AF_INET:
 539         proto = PPP_IP;
 540 #ifdef SNIT_SUPPORT
 541         if (ifp->if_flags & IFF_PROMISC) {
 542             struct nit_if nif;
 543             struct mbuf *m;
 544             int len;
 545
 546             for (len = 0, m = m0; m != NULL; m = m->m_next)
 547                 len += m->m_len;
 548             nif.nif_header = (caddr_t) &snit_ehdr;
 549             nif.nif_hdrlen = sizeof(snit_ehdr);
 550             nif.nif_bodylen = len;
 551             nif.nif_promisc = 0;
 552             snit_intr(ifp, m0, &nif);
 553         }
 554 #endif
 555         break;
 556
 557     default:
 558         m_freem(m0);
 559         return EAFNOSUPPORT;
 560     }
 561
 562     ++ifp->if_opackets;
 563     mp = make_message(m0, PPP_HDRLEN);
 564     m_freem(m0);
 565     if (mp == 0) {
 566         ++ifp->if_oerrors;
 567         return ENOBUFS;
 568     }
 569     mp->b_rptr -= PPP_HDRLEN;
 570     mp->b_rptr[0] = PPP_ALLSTATIONS;
 571     mp->b_rptr[1] = PPP_UI;
 572     mp->b_rptr[2] = proto >> 8;
 573     mp->b_rptr[3] = proto;
 574
 575     s = splstr();
 576     if (sp->flags & DBGLOG)
 577         printf("if_ppp: putnext(%x, %x), r=%x w=%x p=%x\n",
 578                sp->q, mp, mp->b_rptr, mp->b_wptr, proto);
 579     putnext(sp->q, mp);
 580     splx(s);
 581
 582     return 0;
 583 }
 584
 585 /*
 586  * Socket ioctl routine for ppp interfaces.
 587  */
 588 static int
 589 if_ppp_ioctl(ifp, cmd, data)
 590     struct ifnet *ifp;
 591     u_int cmd;
 592     caddr_t data;
 593 {
 594     int s, error;
 595     struct ifreq *ifr = (struct ifreq *) data;
 596     struct ifaddr *ifa = (struct ifaddr *) data;
 597     u_short mtu;
 598
 599     error = 0;
 600     s = splimp();
 601     switch (cmd) {
 602     case SIOCSIFFLAGS:
 603         if ((ifp->if_flags & IFF_RUNNING) == 0)
 604             ifp->if_flags &= ~IFF_UP;
 605         break;
 606
 607     case SIOCSIFADDR:
 608         if (IFA_ADDR(ifa).sa_family != AF_INET)
 609             error = EAFNOSUPPORT;
 610         break;
 611
 612     case SIOCSIFDSTADDR:
 613         if (IFA_ADDR(ifa).sa_family != AF_INET)
 614             error = EAFNOSUPPORT;
 615         break;
 616
 617     case SIOCSIFMTU:
 618         if ((error = NOTSUSER()) != 0)
 619             break;
 620 #ifdef __osf__
 621         /* this hack is necessary because ifioctl checks ifr_data
 622          * in 4.0 and 5.0, but ifr_data and ifr_metric overlay each
 623          * other in the definition of struct ifreq so pppd can't set both.
 624          */
 625         bcopy(ifr->ifr_data, &mtu, sizeof (u_short));
 626         ifr->ifr_mtu = mtu;
 627 #endif
 628
 629         if (ifr->ifr_mtu < PPP_MINMTU || ifr->ifr_mtu > PPP_MAXMTU) {
 630             error = EINVAL;
 631             break;
 632         }
 633         ifp->if_mtu = ifr->ifr_mtu;
 634         break;
 635
 636     case SIOCGIFMTU:
 637         ifr->ifr_mtu = ifp->if_mtu;
 638         break;
 639
 640     case SIOCADDMULTI:
 641     case SIOCDELMULTI:
 642         switch(ifr->ifr_addr.sa_family) {
 643         case AF_INET:
 644             break;
 645         default:
 646             error = EAFNOSUPPORT;
 647             break;
 648         }
 649         break;
 650
 651     default:
 652         error = EINVAL;
 653     }
 654     splx(s);
 655     return (error);
 656 }
 657
 658 /*
 659  * Turn a STREAMS message into an mbuf chain.
 660  */
 661 static struct mbuf *
 662 make_mbufs(mp, off)
 663     mblk_t *mp;
 664     int off;
 665 {
 666     struct mbuf *head, **prevp, *m;
 667     int len, space, n;
 668     unsigned char *cp, *dp;
 669
 670     len = msgdsize(mp);
 671     if (len == 0)
 672         return 0;
 673     prevp = &head;
 674     space = 0;
 675     cp = mp->b_rptr;
 676 #ifdef __osf__
 677     MGETHDR(m, M_DONTWAIT, MT_DATA);
 678     m->m_len = 0;
 679     space = MHLEN;
 680     *prevp = m;
 681     prevp = &m->m_next;
 682     dp = mtod(m, unsigned char *);
 683     len -= space;
 684     off = 0;
 685 #endif
 686     for (;;) {
 687         while (cp >= mp->b_wptr) {
 688             mp = mp->b_cont;
 689             if (mp == 0) {
 690                 *prevp = 0;
 691                 return head;
 692             }
 693             cp = mp->b_rptr;
 694         }
 695         n = mp->b_wptr - cp;
 696         if (space == 0) {
 697             MGET(m, M_DONTWAIT, MT_DATA);
 698             *prevp = m;
 699             if (m == 0) {
 700                 if (head != 0)
 701                     m_freem(head);
 702                 return 0;
 703             }
 704             if (len + off > 2 * MLEN) {
 705 #ifdef __osf__
 706                 MCLGET(m, M_DONTWAIT);
 707 #else
 708                 MCLGET(m);
 709 #endif
 710             }
 711 #ifdef __osf__
 712             space = ((m->m_flags & M_EXT) ? MCLBYTES : MLEN);
 713 #else
 714             space = (m->m_off > MMAXOFF? MCLBYTES: MLEN) - off;
 715             m->m_off += off;
 716 #endif
 717             m->m_len = 0;
 718             len -= space;
 719             dp = mtod(m, unsigned char *);
 720             off = 0;
 721             prevp = &m->m_next;
 722         }
 723         if (n > space)
 724             n = space;
 725         bcopy(cp, dp, n);
 726         cp += n;
 727         dp += n;
 728         space -= n;
 729         m->m_len += n;
 730     }
 731 }
 732
 733 /*
 734  * Turn an mbuf chain into a STREAMS message.
 735  */
 736 #define ALLOCB_MAX      4096
 737
 738 static mblk_t *
 739 make_message(m, off)
 740     struct mbuf *m;
 741     int off;
 742 {
 743     mblk_t *head, **prevp, *mp;
 744     int len, space, n, nb;
 745     unsigned char *cp, *dp;
 746     struct mbuf *nm;
 747
 748     len = 0;
 749     for (nm = m; nm != 0; nm = nm->m_next)
 750         len += nm->m_len;
 751     prevp = &head;
 752     space = 0;
 753     cp = mtod(m, unsigned char *);
 754     nb = m->m_len;
 755     for (;;) {
 756         while (nb <= 0) {
 757             m = m->m_next;
 758             if (m == 0) {
 759                 *prevp = 0;
 760                 return head;
 761             }
 762             cp = mtod(m, unsigned char *);
 763             nb = m->m_len;
 764         }
 765         if (space == 0) {
 766             space = len + off;
 767             if (space > ALLOCB_MAX)
 768                 space = ALLOCB_MAX;
 769             mp = allocb(space, BPRI_LO);
 770             *prevp = mp;
 771             if (mp == 0) {
 772                 if (head != 0)
 773                     freemsg(head);
 774                 return 0;
 775             }
 776             dp = mp->b_rptr += off;
 777             space -= off;
 778             len -= space;
 779             off = 0;
 780             prevp = &mp->b_cont;
 781         }
 782         n = nb < space? nb: space;
 783         bcopy(cp, dp, n);
 784         cp += n;
 785         dp += n;
 786         nb -= n;
 787         space -= n;
 788         mp->b_wptr = dp;
 789     }
 790 }
 791
 792 /*
 793  * Digital UNIX doesn't allow for removing ifnet structures
 794  * from the list.  But then we're not using this as a loadable
 795  * module anyway, so that's OK.
 796  *
 797  * Under SunOS, this should allow the module to be unloaded.
 798  * Unfortunately, it doesn't seem to detach all the references,
 799  * so your system may well crash after you unload this module :-(
 800  */
 801 #ifndef __osf__
 802
 803 /*
 804  * Remove an interface from the system.
 805  * This routine contains magic.
 806  */
 807 #include <net/route.h>
 808 #include <netinet/in_pcb.h>
 809 #include <netinet/ip_var.h>
 810 #include <netinet/tcp.h>
 811 #include <netinet/tcp_timer.h>
 812 #include <netinet/tcp_var.h>
 813 #include <netinet/udp.h>
 814 #include <netinet/udp_var.h>
 815
 816 static void
 817 ppp_if_detach(ifp)
 818     struct ifnet *ifp;
 819 {
 820     int s;
 821     struct inpcb *pcb;
 822     struct ifaddr *ifa;
 823     struct in_ifaddr **inap;
 824     struct ifnet **ifpp;
 825
 826     s = splhigh();
 827
 828     /*
 829      * Clear the interface from any routes currently cached in
 830      * TCP or UDP protocol control blocks.
 831      */
 832     for (pcb = tcb.inp_next; pcb != &tcb; pcb = pcb->inp_next)
 833         if (pcb->inp_route.ro_rt && pcb->inp_route.ro_rt->rt_ifp == ifp)
 834             in_losing(pcb);
 835     for (pcb = udb.inp_next; pcb != &udb; pcb = pcb->inp_next)
 836         if (pcb->inp_route.ro_rt && pcb->inp_route.ro_rt->rt_ifp == ifp)
 837             in_losing(pcb);
 838
 839     /*
 840      * Delete routes through all addresses of the interface.
 841      */
 842     for (ifa = ifp->if_addrlist; ifa != 0; ifa = ifa->ifa_next) {
 843         rtinit(ifa, ifa, SIOCDELRT, RTF_HOST);
 844         rtinit(ifa, ifa, SIOCDELRT, 0);
 845     }
 846
 847     /*
 848      * Unlink the interface's address(es) from the in_ifaddr list.
 849      */
 850     for (inap = &in_ifaddr; *inap != 0; ) {
 851         if ((*inap)->ia_ifa.ifa_ifp == ifp)
 852             *inap = (*inap)->ia_next;
 853         else
 854             inap = &(*inap)->ia_next;
 855     }
 856
 857     /*
 858      * Delete the interface from the ifnet list.
 859      */
 860     for (ifpp = &ifnet; (*ifpp) != 0; ) {
 861         if (*ifpp == ifp)
 862             break;
 863         ifpp = &(*ifpp)->if_next;
 864     }
 865     if (*ifpp == 0)
 866         printf("couldn't find interface ppp%d in ifnet list\n", ifp->if_unit);
 867     else
 868         *ifpp = ifp->if_next;
 869
 870     splx(s);
 871 }
 872
 873 #endif /* __osf__ */