sys/ipkdb/ipkdb_ipkdb.c

   1 /*      $NetBSD: ipkdb_ipkdb.c,v 1.26 2009/04/12 22:37:50 elad Exp $    */
   2
   3 /*
   4  * Copyright (C) 1993-2000 Wolfgang Solfrank.
   5  * Copyright (C) 1993-2000 TooLs GmbH.
   6  * All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  * 3. All advertising materials mentioning features or use of this software
  17  *    must display the following acknowledgement:
  18  *      This product includes software developed by TooLs GmbH.
  19  * 4. The name of TooLs GmbH may not be used to endorse or promote products
  20  *    derived from this software without specific prior written permission.
  21  *
  22  * THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``AS IS'' AND ANY EXPRESS OR
  23  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  24  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  25  * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  26  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  27  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
  28  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
  29  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
  30  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
  31  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  32  */
  33
  34 #include <sys/cdefs.h>
  35 __KERNEL_RCSID(0, "$NetBSD: ipkdb_ipkdb.c,v 1.26 2009/04/12 22:37:50 elad Exp $");
  36
  37 #include "opt_ipkdb.h"
  38
  39 #include <sys/param.h>
  40 #include <sys/socket.h>
  41 #include <sys/mbuf.h>
  42 #include <sys/reboot.h>
  43 #include <sys/systm.h>
  44 #include <sys/kauth.h>
  45 #include <sys/cpu.h>
  46
  47 #include <net/if.h>
  48 #include <net/if_arp.h>
  49 #include <net/if_ether.h>
  50
  51 #include <netinet/in.h>
  52 #include <netinet/in_systm.h>
  53 #include <netinet/if_inarp.h>
  54 #include <netinet/ip.h>
  55 #include <netinet/ip_var.h>
  56 #include <netinet/udp.h>
  57
  58 #include <machine/reg.h>
  59
  60 #include <ipkdb/ipkdb.h>
  61 #include <machine/ipkdb.h>
  62
  63 int ipkdbpanic = 0;
  64
  65 #ifndef IPKDBKEY
  66 #error You must specify the IPKDBKEY option to use IPKDB.
  67 #else
  68 static char ipkdbkey[] = IPKDBKEY;
  69 #endif
  70
  71 static struct ipkdb_if ipkdb_if;
  72
  73 static kauth_listener_t ipkdb_listener;
  74
  75 static u_char *ipkdbaddr(u_char *, int *, void **);
  76 static void peekmem(struct ipkdb_if *, u_char *, void *, long);
  77 static void pokemem(struct ipkdb_if *, u_char *, void *, long);
  78 static u_int32_t getnl(void *);
  79 static u_int getns(void *);
  80 static void setnl(void *, u_int32_t);
  81 static void setns(void *, int);
  82 static u_short cksum(u_short, void *, int);
  83 static int assemble(struct ipkdb_if *, void *);
  84 static char *inpkt(struct ipkdb_if *, char *, int);
  85 static void outpkt(struct ipkdb_if *, char *, int, int, int);
  86 static void init(struct ipkdb_if *);
  87 static void *chksum(void *, int);
  88 static void getpkt(struct ipkdb_if *, char *, int *);
  89 static void putpkt(struct ipkdb_if *, const char *, int);
  90 static int check_ipkdb(struct ipkdb_if *, struct in_addr *, char *, int);
  91 static int connectipkdb(struct ipkdb_if *, char *, int);
  92 static int hmac_init(void);
  93
  94 static int
  95 ipkdb_listener_cb(kauth_cred_t cred, kauth_action_t action, void *cookie,
  96     void *arg0, void *arg1, void *arg2, void *arg3)
  97 {
  98         enum kauth_system_req req;
  99         int result;
 100
 101         req = (enum kauth_system_req)arg0;
 102         result = KAUTH_RESULT_DEFER;
 103
 104         if ((action != KAUTH_SYSTEM_DEBUG) ||
 105             (req != KAUTH_REQ_SYSTEM_DEBUG_IPKDB))
 106                 return result;
 107
 108         result = KAUTH_RESULT_ALLOW;
 109
 110         return result;
 111 }
 112
 113 void
 114 ipkdb_init(void)
 115 {
 116         ipkdbinit();
 117         if (   ipkdbifinit(&ipkdb_if) < 0
 118             || !(ipkdb_if.flags&IPKDB_MYHW)
 119             || !hmac_init()) {
 120                 /* Interface not found, drop IPKDB */
 121                 printf("IPKDB: No interface found!\n");
 122                 boothowto &= ~RB_KDB;
 123         }
 124
 125         ipkdb_listener = kauth_listen_scope(KAUTH_SCOPE_SYSTEM,
 126             ipkdb_listener_cb, NULL);
 127 }
 128
 129 void
 130 ipkdb_connect(int when)
 131 {
 132         boothowto |= RB_KDB;
 133         if (when == 0)
 134                 printf("waiting for remote debugger\n");
 135         ipkdb_trap();
 136 }
 137
 138 void
 139 ipkdb_panic(void)
 140 {
 141         ipkdbpanic = 1;
 142         ipkdb_trap();
 143 }
 144
 145 /*
 146  * Doesn't handle overlapping regions!
 147  */
 148 void
 149 ipkdbcopy(const void *s, void *d, int n)
 150 {
 151         const char *sp = s;
 152         char *dp = d;
 153
 154         while (--n >= 0)
 155                 *dp++ = *sp++;
 156 }
 157
 158 void
 159 ipkdbzero(void *d, int n)
 160 {
 161         char *dp = d;
 162
 163         while (--n >= 0)
 164                 *dp++ = 0;
 165 }
 166
 167 int
 168 ipkdbcmp(void *s, void *d, int n)
 169 {
 170         char *sp = s, *dp = d;
 171
 172         while (--n >= 0)
 173                 if (*sp++ != *dp++)
 174                         return *--dp - *--sp;
 175         return 0;
 176 }
 177
 178 int
 179 ipkdbcmds(void)
 180 {
 181         static char buf[512];
 182         char *cp;
 183         int plen;
 184
 185         if (!(ipkdb_if.flags&IPKDB_MYHW))       /* no interface */
 186                 return IPKDB_CMD_EXIT;
 187         init(&ipkdb_if);
 188         if (ipkdbpanic > 1) {
 189                 ipkdb_if.leave(&ipkdb_if);
 190                 return IPKDB_CMD_RUN;
 191         }
 192         putpkt(&ipkdb_if, "s", 1);
 193         while (1) {
 194                 getpkt(&ipkdb_if, buf, &plen);
 195                 if (!plen) {
 196                         if (ipkdbpanic && ipkdb_poll()) {
 197                                 ipkdb_if.leave(&ipkdb_if);
 198                                 return IPKDB_CMD_RUN;
 199                         } else
 200                                 continue;
 201                 } else
 202                         ipkdbpanic = 0;
 203                 switch (*buf) {
 204                 default:
 205                         putpkt(&ipkdb_if, "eunknown command", 16);
 206                         break;
 207                 case 'O':
 208                         /* This is an allowed reconnect, ack it */
 209                         putpkt(&ipkdb_if, "s", 1);
 210                         break;
 211                 case 'R':
 212                         peekmem(&ipkdb_if, buf, ipkdbregs, sizeof ipkdbregs);
 213                         break;
 214                 case 'W':
 215                         if (plen != sizeof ipkdbregs + 1) {
 216                                 putpkt(&ipkdb_if, "einvalid register size", 22);
 217                                 break;
 218                         }
 219                         pokemem(&ipkdb_if, buf + 1, ipkdbregs, sizeof ipkdbregs);
 220                         break;
 221                 case 'M':
 222                         {
 223                                 void *addr, *len;
 224
 225                                 plen--;
 226                                 if (   !(cp = ipkdbaddr(buf + 1, &plen, &addr))
 227                                     || !ipkdbaddr(cp, &plen, &len)) {
 228                                         putpkt(&ipkdb_if, "einvalid peek format", 20);
 229                                         break;
 230                                 }
 231                                 peekmem(&ipkdb_if, buf, addr, (long)len);
 232                                 break;
 233                         }
 234                 case 'N':
 235                         {
 236                                 void *addr, *len;
 237
 238                                 plen--;
 239                                 if (   !(cp = ipkdbaddr(buf + 1, &plen, &addr))
 240                                     || !(cp = ipkdbaddr(cp, &plen, &len))
 241                                     || plen < (long)len) {
 242                                         putpkt(&ipkdb_if, "einvalid poke format", 20);
 243                                         break;
 244                                 }
 245                                 pokemem(&ipkdb_if, cp, addr, (long)len);
 246                                 break;
 247                         }
 248                 case 'S':
 249                         ipkdb_if.leave(&ipkdb_if);
 250                         return IPKDB_CMD_STEP;
 251                 case 'X':
 252                         putpkt(&ipkdb_if, "ok",2);
 253                         ipkdb_if.leave(&ipkdb_if);
 254                         return IPKDB_CMD_EXIT;
 255                 case 'C':
 256                         ipkdb_if.leave(&ipkdb_if);
 257                         return IPKDB_CMD_RUN;
 258                 }
 259         }
 260 }
 261
 262 static u_char *
 263 ipkdbaddr(u_char *cp, int *pl, void **dp)
 264 {
 265         /* Assume that sizeof(void *) <= sizeof(u_long) */
 266         u_long l;
 267         int i;
 268
 269         if ((*pl -= sizeof *dp) < 0)
 270                 return 0;
 271         for (i = sizeof *dp, l = 0; --i >= 0;) {
 272                 l <<= 8;
 273                 l |= *cp++;
 274         }
 275         *dp = (void *)l;
 276         return cp;
 277 }
 278
 279 static void
 280 peekmem(struct ipkdb_if *ifp, u_char *buf, void *addr, long len)
 281 {
 282         u_char *cp, *p = addr;
 283         int l;
 284
 285         cp = buf;
 286         *cp++ = 'p';
 287         for (l = len; --l >= 0;)
 288                 *cp++ = ipkdbfbyte(p++);
 289         putpkt(ifp, buf, len + 1);
 290 }
 291
 292 static void
 293 pokemem(struct ipkdb_if *ifp, u_char *cp, void *addr, long len)
 294 {
 295         u_char *p = addr;
 296
 297         while (--len >= 0)
 298                 ipkdbsbyte(p++, *cp++);
 299         putpkt(ifp, "ok", 2);
 300 }
 301
 302 inline static u_int32_t
 303 getnl(void *vs)
 304 {
 305         u_char *s = vs;
 306
 307         return (*s << 24)|(s[1] << 16)|(s[2] << 8)|s[3];
 308 }
 309
 310 inline static u_int
 311 getns(void *vs)
 312 {
 313         u_char *s = vs;
 314
 315         return (*s << 8)|s[1];
 316 }
 317
 318 inline static void
 319 setnl(void *vs, u_int32_t l)
 320 {
 321         u_char *s = vs;
 322
 323         *s++ = l >> 24;
 324         *s++ = l >> 16;
 325         *s++ = l >> 8;
 326         *s = l;
 327 }
 328
 329 inline static void
 330 setns(void *vs, int l)
 331 {
 332         u_char *s = vs;
 333
 334         *s++ = l >> 8;
 335         *s = l;
 336 }
 337
 338 static u_short
 339 cksum(u_short st, void *vcp, int l)
 340 {
 341         u_char *cp = vcp;
 342         u_long s;
 343
 344         for (s = st; (l -= 2) >= 0; cp += 2)
 345                 s += (*cp << 8) + cp[1];
 346         if (l == -1)
 347                 s += *cp << 8;
 348         while (s&0xffff0000)
 349                 s = (s&0xffff) + (s >> 16);
 350         return s == 0xffff ? 0 : s;
 351 }
 352
 353 static int
 354 assemble(struct ipkdb_if *ifp, void *buf)
 355 {
 356         struct ip *ip, iph;
 357         int off, len, i;
 358         u_char *cp, *ecp;
 359
 360         ip = (struct ip *)buf;
 361         ipkdbcopy(ip, &iph, sizeof iph);
 362         iph.ip_hl = 5;
 363         iph.ip_tos = 0;
 364         iph.ip_len = 0;
 365         iph.ip_off = 0;
 366         iph.ip_ttl = 0;
 367         iph.ip_sum = 0;
 368         if (ifp->asslen) {
 369                 if (ipkdbcmp(&iph, ifp->ass, sizeof iph)) {
 370                         /*
 371                          * different packet
 372                          * decide whether to keep the old
 373                          * or start a new one
 374                          */
 375                         i = (getns(&ip->ip_id)
 376                              ^ getns(&((struct ip *)ifp->ass)->ip_id));
 377                         i ^= ((i >> 2) ^ (i >> 4) ^ (i >> 8) ^ (i >> 12));
 378                         if (i & 1)
 379                                 /* keep the old */
 380                                 return 0;
 381                         ifp->asslen = 0;
 382                 }
 383         }
 384         if (!ifp->asslen) {
 385                 ipkdbzero(ifp->assbit, sizeof ifp->assbit);
 386                 ipkdbcopy(&iph, ifp->ass, sizeof iph);
 387         }
 388         off = getns(&ip->ip_off);
 389         len = ((off & IP_OFFMASK) << 3) + getns(&ip->ip_len) - ip->ip_hl * 4;
 390         if (ifp->asslen < len)
 391                 ifp->asslen = len;
 392         if (ifp->asslen + sizeof *ip > sizeof ifp->ass) {
 393                 /* packet too long */
 394                 ifp->asslen = 0;
 395                 return 0;
 396         }
 397         if (!(off & IP_MF)) {
 398                 off &= IP_OFFMASK;
 399                 cp = ifp->assbit + (off >> 3);
 400                 for (i = (off & 7); i < 8; *cp |= 1 << i++);
 401                 for (; cp < ifp->assbit + sizeof ifp->assbit; *cp++ = -1);
 402         } else {
 403                 off &= IP_OFFMASK;
 404                 cp = ifp->assbit + (off >> 3);
 405                 ecp = ifp->assbit + (len >> 6);
 406                 if (cp == ecp)
 407                         for (i = (off & 7); i <= ((len >> 3) & 7);
 408                              *cp |= 1 << i++);
 409                 else {
 410                         for (i = (off & 7); i < 8; *cp |= 1 << i++);
 411                         for (; ++cp < ecp; *cp = -1);
 412                         for (i = 0; i < ((len >> 3) & 7); *cp |= 1 << i++);
 413                 }
 414         }
 415         ipkdbcopy((char *)buf + ip->ip_hl * 4,
 416                   ifp->ass + sizeof *ip + (off << 3),
 417                   len - (off << 3));
 418         for (cp = ifp->assbit; cp < ifp->assbit + sizeof ifp->assbit;)
 419                 if (*cp++ != (u_char)-1)
 420                         /* not complete */
 421                         return 0;
 422         ip = (struct ip *)ifp->ass;
 423         setns(&ip->ip_len, sizeof *ip + ifp->asslen);
 424         /* complete */
 425         return 1;
 426 }
 427
 428 static char *
 429 inpkt(struct ipkdb_if *ifp, char *ibuf, int poll)
 430 {
 431         int cnt = 1000000;
 432         int l, ul;
 433         struct ether_header *eh;
 434         struct arphdr *ah;
 435         struct ip *ip;
 436         struct udphdr *udp;
 437         struct ipovly ipo;
 438
 439         while (1) {
 440                 l = ifp->receive(ifp, ibuf, poll != 0);
 441                 if (!l) {
 442                         if (poll == 1 || (poll == 2 && --cnt <= 0))
 443                                 break;
 444                         else
 445                                 continue;
 446                 }
 447                 eh = (struct ether_header *)ibuf;
 448                 switch (getns(&eh->ether_type)) {
 449                 case ETHERTYPE_ARP:
 450                         ah = (struct arphdr *)(ibuf + 14);
 451                         if (   getns(&ah->ar_hrd) != ARPHRD_ETHER
 452                             || getns(&ah->ar_pro) != ETHERTYPE_IP
 453                             || ah->ar_hln != 6
 454                             || ah->ar_pln != 4)
 455                                 /* unsupported arp packet */
 456                                 break;
 457                         switch (getns(&ah->ar_op)) {
 458                         case ARPOP_REQUEST:
 459                                 if (   (ifp->flags&IPKDB_MYIP)
 460                                     && !ipkdbcmp(ar_tpa(ah),
 461                                                  ifp->myinetaddr,
 462                                                  sizeof ifp->myinetaddr)) {
 463                                         /* someone requested my address */
 464                                         ipkdbcopy(eh->ether_shost,
 465                                                   eh->ether_dhost,
 466                                                   sizeof eh->ether_dhost);
 467                                         ipkdbcopy(ifp->myenetaddr,
 468                                                   eh->ether_shost,
 469                                                   sizeof eh->ether_shost);
 470                                         setns(&ah->ar_op, ARPOP_REPLY);
 471                                         ipkdbcopy(ar_sha(ah),
 472                                                   ar_tha(ah),
 473                                                   ah->ar_hln);
 474                                         ipkdbcopy(ar_spa(ah),
 475                                                   ar_tpa(ah),
 476                                                   ah->ar_pln);
 477                                         ipkdbcopy(ifp->myenetaddr,
 478                                                   ar_sha(ah),
 479                                                   ah->ar_hln);
 480                                         ipkdbcopy(ifp->myinetaddr,
 481                                                   ar_spa(ah),
 482                                                   ah->ar_pln);
 483                                         ifp->send(ifp, ibuf, 74);
 484                                         continue;
 485                                 }
 486                                 break;
 487                         default:
 488                                 break;
 489                         }
 490                         break;
 491                 case ETHERTYPE_IP:
 492                         ip = (struct ip *)(ibuf + 14);
 493                         if (   ip->ip_v != IPVERSION
 494                             || ip->ip_hl < 5
 495                             || getns(&ip->ip_len) + 14 > l)
 496                                 /* invalid packet */
 497                                 break;
 498                         if (cksum(0, ip, ip->ip_hl * 4))
 499                                 /* wrong checksum */
 500                                 break;
 501                         if (ip->ip_p != IPPROTO_UDP)
 502                                 break;
 503                         if (getns(&ip->ip_off) & ~IP_DF) {
 504                                 if (!assemble(ifp, ip))
 505                                         break;
 506                                 ip = (struct ip *)ifp->ass;
 507                                 ifp->asslen = 0;
 508                         }
 509                         udp = (struct udphdr *)((char *)ip + ip->ip_hl * 4);
 510                         ul = getns(&ip->ip_len) - ip->ip_hl * 4;
 511                         if (getns(&udp->uh_ulen) != ul)
 512                                 /* invalid UDP packet length */
 513                                 break;
 514                         ipkdbcopy(ip, &ipo, sizeof ipo);
 515                         ipkdbzero(ipo.ih_x1, sizeof ipo.ih_x1);
 516                         ipo.ih_len = udp->uh_ulen;
 517                         if (   udp->uh_sum
 518                             && cksum(cksum(0, &ipo, sizeof ipo), udp, ul))
 519                                 /* wrong checksum */
 520                                 break;
 521                         if (!(ifp->flags & IPKDB_MYIP)) {
 522                                 if (   getns(&udp->uh_sport) == 67
 523                                     && getns(&udp->uh_dport) == 68
 524                                     && *(char *)(udp + 1) == 2) {
 525                                         /* this is a BOOTP reply to our ethernet address */
 526                                         /* should check a bit more?             XXX */
 527                                         char *bootp = (char *)(udp + 1);
 528                                         ipkdbcopy(bootp + 16,
 529                                                   ifp->myinetaddr,
 530                                                   sizeof ifp->myinetaddr);
 531                                         ifp->flags |= IPKDB_MYIP;
 532                                 }
 533                                 /* give caller a chance to resend his request */
 534                                 return 0;
 535                         }
 536                         if (   ipkdbcmp(&ip->ip_dst, ifp->myinetaddr, sizeof ifp->myinetaddr)
 537                             || getns(&udp->uh_dport) != IPKDBPORT)
 538                                 break;
 539                         /* so now it's a UDP packet for the debugger */
 540                         {
 541                                 /* Check for reconnect packet */
 542                                 u_char *p;
 543
 544                                 p = (u_char *)(udp + 1);
 545                                 if (!getnl(p) && p[6] == 'O') {
 546                                         l = getns(p + 4);
 547                                         if (   l <= ul - sizeof *udp - 6
 548                                             && check_ipkdb(ifp, &ip->ip_src,
 549                                                            p, l + 6)) {
 550                                                 ipkdbcopy(&ip->ip_src,
 551                                                           ifp->hisinetaddr,
 552                                                           sizeof ifp->hisinetaddr);
 553                                                 ipkdbcopy(eh->ether_shost,
 554                                                           ifp->hisenetaddr,
 555                                                           sizeof ifp->hisenetaddr);
 556                                                 ifp->hisport = getns(&udp->uh_sport);
 557                                                 ifp->flags |= IPKDB_HISHW|IPKDB_HISIP;
 558                                                 return p;
 559                                         }
 560                                 }
 561                         }
 562                         if (   (ifp->flags&IPKDB_HISIP)
 563                             && ipkdbcmp(&ip->ip_src,
 564                                         ifp->hisinetaddr, sizeof ifp->hisinetaddr))
 565                                 /* It's a packet from someone else */
 566                                 break;
 567                         if (!(ifp->flags&IPKDB_HISIP))
 568                                 break;
 569                         return (char *)(udp + 1);
 570                 default:
 571                         /* unknown type */
 572                         break;
 573                 }
 574         }
 575         return 0;
 576 }
 577
 578 static short ipkdb_ipid = 0;
 579
 580 static void
 581 outpkt(struct ipkdb_if *ifp, char *in, int l, int srcport, int dstport)
 582 {
 583         struct ether_header *eh;
 584         struct ip *ip;
 585         struct udphdr *udp;
 586         u_char *cp;
 587         char _obuf[ETHERMTU + 16];
 588 #define obuf    (_obuf + 2)             /* align ip data in packet */
 589         struct ipovly ipo;
 590         int i, off;
 591
 592         ipkdbzero(_obuf, sizeof _obuf);
 593         eh = (struct ether_header *)obuf;
 594         /*
 595          * If we don't have his ethernet address, or this is a bootp request,
 596          * broadcast the packet.
 597          */
 598         if (!(ifp->flags & IPKDB_HISHW)
 599             || dstport == 67)
 600                 for (cp = eh->ether_dhost;
 601                      cp < eh->ether_dhost + sizeof eh->ether_dhost;
 602                      *cp++ = -1);
 603         else
 604                 ipkdbcopy(ifp->hisenetaddr, eh->ether_dhost, sizeof eh->ether_dhost);
 605         ipkdbcopy(ifp->myenetaddr, eh->ether_shost, sizeof eh->ether_shost);
 606         setns(&eh->ether_type, ETHERTYPE_IP);
 607         ip = (struct ip *)(obuf + 14);
 608         ip->ip_v = IPVERSION;
 609         ip->ip_hl = 5;
 610         setns(&ip->ip_id, ipkdb_ipid++);
 611         ip->ip_ttl = 255;
 612         ip->ip_p = IPPROTO_UDP;
 613         ipkdbcopy(ifp->myinetaddr, &ip->ip_src, sizeof ip->ip_src);
 614         /*
 615          * If this is a bootp request, broadcast it.
 616          */
 617         if (dstport == 67)
 618                 for (cp = (u_char *)&ip->ip_dst;
 619                      cp < (u_char *)&ip->ip_dst + sizeof ip->ip_dst;
 620                      *cp++ = -1);
 621         else
 622                 ipkdbcopy(ifp->hisinetaddr, &ip->ip_dst, sizeof ip->ip_dst);
 623         udp = (struct udphdr *)(ip + 1);
 624         setns(&udp->uh_sport, srcport);
 625         setns(&udp->uh_dport, dstport);
 626         setns(&udp->uh_ulen, l + sizeof *udp);
 627         ipkdbcopy(ip, &ipo, sizeof ipo);
 628         ipkdbzero(ipo.ih_x1, sizeof ipo.ih_x1);
 629         ipo.ih_len = udp->uh_ulen;
 630         setns(&udp->uh_sum,
 631               ~cksum(cksum(cksum(0, &ipo, sizeof ipo),
 632                            udp, sizeof *udp),
 633                      in, l));
 634         for (cp = (u_char *)(udp + 1), l += sizeof *udp, off = 0;
 635              l > 0;
 636              l -= i, in += i, off += i, cp = (u_char *)udp) {
 637                 i = l > ifp->mtu - sizeof *ip ? ((ifp->mtu - sizeof *ip) & ~7) : l;
 638                 ipkdbcopy(in, cp, i);
 639                 setns(&ip->ip_len, i + sizeof *ip);
 640                 setns(&ip->ip_off, (l > i ? IP_MF : 0) | (off >> 3));
 641                 ip->ip_sum = 0;
 642                 setns(&ip->ip_sum, ~cksum(0, ip, sizeof *ip));
 643                 if (i + sizeof *ip < ETHERMIN)
 644                         i = ETHERMIN - sizeof *ip;
 645                 ifp->send(ifp, obuf, i + sizeof *ip + 14);
 646         }
 647 #undef  obuf
 648 }
 649
 650 static void
 651 init(struct ipkdb_if *ifp)
 652 {
 653         u_char *cp;
 654         u_char _ibuf[ETHERMTU + 16];
 655 #define ibuf    (_ibuf + 2)             /* align ip data in packet */
 656         int secs = 0;
 657
 658         ifp->start(ifp);
 659         if (ifp->flags & IPKDB_MYIP)
 660                 return;
 661
 662         while (!(ifp->flags & IPKDB_MYIP)) {
 663                 ipkdbzero(_ibuf, sizeof _ibuf);
 664                 cp = _ibuf;
 665                 *cp++ = 1;              /* BOOTP_REQUEST */
 666                 *cp++ = 1;              /* Ethernet hardware */
 667                 *cp++ = 6;              /* length of address */
 668                 setnl(++cp, 0x12345678); /* some random number? */
 669                 setns(cp + 4, secs++);
 670                 ipkdbcopy(ifp->myenetaddr, cp + 24, sizeof ifp->myenetaddr);
 671                 outpkt(ifp, _ibuf, 300, 68, 67);
 672                 inpkt(ifp, ibuf, 2);
 673                 if (ipkdbpanic && ipkdb_poll()) {
 674                         ipkdbpanic++;
 675                         return;
 676                 }
 677         }
 678         cp = ifp->myinetaddr;
 679         printf("My IP address is %d.%d.%d.%d\n",
 680                cp[0], cp[1], cp[2], cp[3]);
 681 #undef  ibuf
 682 }
 683
 684 /* HMAC Checksumming routines, see draft-ietf-ipsec-hmac-md5-00.txt */
 685 #define LENCHK  16      /* Length of checksum in bytes */
 686
 687 /*
 688  * This code is based on the MD5 implementation as found in ssh.
 689  * It's quite a bit hacked by myself, but the original has
 690  * the following non-copyright comments on it:
 691  */
 692 /* This code has been heavily hacked by Tatu Ylonen <ylo@cs.hut.fi> to
 693    make it compile on machines like Cray that don't have a 32 bit integer
 694    type. */
 695 /*
 696  * This code implements the MD5 message-digest algorithm.
 697  * The algorithm is due to Ron Rivest.  This code was
 698  * written by Colin Plumb in 1993, no copyright is claimed.
 699  * This code is in the public domain; do with it what you wish.
 700  *
 701  * Equivalent code is available from RSA Data Security, Inc.
 702  * This code has been tested against that, and is equivalent,
 703  * except that you don't need to include two pages of legalese
 704  * with every copy.
 705  */
 706 static struct ipkdb_MD5Context {
 707         u_int buf[4];
 708         u_int bits[2];
 709         u_char in[64];
 710 } icontext, ocontext;
 711
 712 static u_int32_t getNl(void *);
 713 static void setNl(void *, u_int32_t);
 714 static void ipkdb_MD5Transform(struct ipkdb_MD5Context *);
 715 static void ipkdb_MD5Init(struct ipkdb_MD5Context *);
 716 static void ipkdb_MD5Update(struct ipkdb_MD5Context *, u_char *, u_int);
 717 static u_char *ipkdb_MD5Final(struct ipkdb_MD5Context *);
 718
 719 inline static u_int32_t
 720 getNl(void *vs)
 721 {
 722         u_char *s = vs;
 723
 724         return *s | (s[1] << 8) | (s[2] << 16) | (s[3] << 24);
 725 }
 726
 727 inline static void
 728 setNl(void *vs, u_int32_t l)
 729 {
 730         u_char *s = vs;
 731
 732         *s++ = l;
 733         *s++ = l >> 8;
 734         *s++ = l >> 16;
 735         *s = l >> 24;
 736 }
 737
 738 /* The four core functions - F1 is optimized somewhat */
 739 /* #define F1(x, y, z)  (((x) & (y)) | (~(x) & (z))) */
 740 #define F1(x, y, z)     ((z) ^ ((x) & ((y) ^ (z))))
 741 #define F2(x, y, z)     F1(z, x, y)
 742 #define F3(x, y, z)     ((x) ^ (y) ^ (z))
 743 #define F4(x, y, z)     ((y) ^ ((x) | ~(z)))
 744
 745 /* This is the central step in the MD5 algorithm. */
 746 #define ipkdb_MD5STEP(f, w, x, y, z, data, s) \
 747         ((w) += f(x, y, z) + (data), \
 748          (w) = ((w) << (s)) | (((w) >> (32 - s)) & 0xffffffff), \
 749          (w) += (x))
 750
 751 /*
 752  * The core of the MD5 algorithm, this alters an existing MD5 hash to
 753  * reflect the addition of 16 longwords of new data.  MD5Update blocks
 754  * the data for this routine.
 755  */
 756 static void
 757 ipkdb_MD5Transform(struct ipkdb_MD5Context *ctx)
 758 {
 759         u_int a, b, c, d, i;
 760         u_int in[16];
 761
 762         for (i = 0; i < 16; i++)
 763                 in[i] = getNl(ctx->in + 4 * i);
 764
 765         a = ctx->buf[0];
 766         b = ctx->buf[1];
 767         c = ctx->buf[2];
 768         d = ctx->buf[3];
 769
 770         ipkdb_MD5STEP(F1, a, b, c, d, in[0] + 0xd76aa478, 7);
 771         ipkdb_MD5STEP(F1, d, a, b, c, in[1] + 0xe8c7b756, 12);
 772         ipkdb_MD5STEP(F1, c, d, a, b, in[2] + 0x242070db, 17);
 773         ipkdb_MD5STEP(F1, b, c, d, a, in[3] + 0xc1bdceee, 22);
 774         ipkdb_MD5STEP(F1, a, b, c, d, in[4] + 0xf57c0faf, 7);
 775         ipkdb_MD5STEP(F1, d, a, b, c, in[5] + 0x4787c62a, 12);
 776         ipkdb_MD5STEP(F1, c, d, a, b, in[6] + 0xa8304613, 17);
 777         ipkdb_MD5STEP(F1, b, c, d, a, in[7] + 0xfd469501, 22);
 778         ipkdb_MD5STEP(F1, a, b, c, d, in[8] + 0x698098d8, 7);
 779         ipkdb_MD5STEP(F1, d, a, b, c, in[9] + 0x8b44f7af, 12);
 780         ipkdb_MD5STEP(F1, c, d, a, b, in[10] + 0xffff5bb1, 17);
 781         ipkdb_MD5STEP(F1, b, c, d, a, in[11] + 0x895cd7be, 22);
 782         ipkdb_MD5STEP(F1, a, b, c, d, in[12] + 0x6b901122, 7);
 783         ipkdb_MD5STEP(F1, d, a, b, c, in[13] + 0xfd987193, 12);
 784         ipkdb_MD5STEP(F1, c, d, a, b, in[14] + 0xa679438e, 17);
 785         ipkdb_MD5STEP(F1, b, c, d, a, in[15] + 0x49b40821, 22);
 786
 787         ipkdb_MD5STEP(F2, a, b, c, d, in[1] + 0xf61e2562, 5);
 788         ipkdb_MD5STEP(F2, d, a, b, c, in[6] + 0xc040b340, 9);
 789         ipkdb_MD5STEP(F2, c, d, a, b, in[11] + 0x265e5a51, 14);
 790         ipkdb_MD5STEP(F2, b, c, d, a, in[0] + 0xe9b6c7aa, 20);
 791         ipkdb_MD5STEP(F2, a, b, c, d, in[5] + 0xd62f105d, 5);
 792         ipkdb_MD5STEP(F2, d, a, b, c, in[10] + 0x02441453, 9);
 793         ipkdb_MD5STEP(F2, c, d, a, b, in[15] + 0xd8a1e681, 14);
 794         ipkdb_MD5STEP(F2, b, c, d, a, in[4] + 0xe7d3fbc8, 20);
 795         ipkdb_MD5STEP(F2, a, b, c, d, in[9] + 0x21e1cde6, 5);
 796         ipkdb_MD5STEP(F2, d, a, b, c, in[14] + 0xc33707d6, 9);
 797         ipkdb_MD5STEP(F2, c, d, a, b, in[3] + 0xf4d50d87, 14);
 798         ipkdb_MD5STEP(F2, b, c, d, a, in[8] + 0x455a14ed, 20);
 799         ipkdb_MD5STEP(F2, a, b, c, d, in[13] + 0xa9e3e905, 5);
 800         ipkdb_MD5STEP(F2, d, a, b, c, in[2] + 0xfcefa3f8, 9);
 801         ipkdb_MD5STEP(F2, c, d, a, b, in[7] + 0x676f02d9, 14);
 802         ipkdb_MD5STEP(F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20);
 803
 804         ipkdb_MD5STEP(F3, a, b, c, d, in[5] + 0xfffa3942, 4);
 805         ipkdb_MD5STEP(F3, d, a, b, c, in[8] + 0x8771f681, 11);
 806         ipkdb_MD5STEP(F3, c, d, a, b, in[11] + 0x6d9d6122, 16);
 807         ipkdb_MD5STEP(F3, b, c, d, a, in[14] + 0xfde5380c, 23);
 808         ipkdb_MD5STEP(F3, a, b, c, d, in[1] + 0xa4beea44, 4);
 809         ipkdb_MD5STEP(F3, d, a, b, c, in[4] + 0x4bdecfa9, 11);
 810         ipkdb_MD5STEP(F3, c, d, a, b, in[7] + 0xf6bb4b60, 16);
 811         ipkdb_MD5STEP(F3, b, c, d, a, in[10] + 0xbebfbc70, 23);
 812         ipkdb_MD5STEP(F3, a, b, c, d, in[13] + 0x289b7ec6, 4);
 813         ipkdb_MD5STEP(F3, d, a, b, c, in[0] + 0xeaa127fa, 11);
 814         ipkdb_MD5STEP(F3, c, d, a, b, in[3] + 0xd4ef3085, 16);
 815         ipkdb_MD5STEP(F3, b, c, d, a, in[6] + 0x04881d05, 23);
 816         ipkdb_MD5STEP(F3, a, b, c, d, in[9] + 0xd9d4d039, 4);
 817         ipkdb_MD5STEP(F3, d, a, b, c, in[12] + 0xe6db99e5, 11);
 818         ipkdb_MD5STEP(F3, c, d, a, b, in[15] + 0x1fa27cf8, 16);
 819         ipkdb_MD5STEP(F3, b, c, d, a, in[2] + 0xc4ac5665, 23);
 820
 821         ipkdb_MD5STEP(F4, a, b, c, d, in[0] + 0xf4292244, 6);
 822         ipkdb_MD5STEP(F4, d, a, b, c, in[7] + 0x432aff97, 10);
 823         ipkdb_MD5STEP(F4, c, d, a, b, in[14] + 0xab9423a7, 15);
 824         ipkdb_MD5STEP(F4, b, c, d, a, in[5] + 0xfc93a039, 21);
 825         ipkdb_MD5STEP(F4, a, b, c, d, in[12] + 0x655b59c3, 6);
 826         ipkdb_MD5STEP(F4, d, a, b, c, in[3] + 0x8f0ccc92, 10);
 827         ipkdb_MD5STEP(F4, c, d, a, b, in[10] + 0xffeff47d, 15);
 828         ipkdb_MD5STEP(F4, b, c, d, a, in[1] + 0x85845dd1, 21);
 829         ipkdb_MD5STEP(F4, a, b, c, d, in[8] + 0x6fa87e4f, 6);
 830         ipkdb_MD5STEP(F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10);
 831         ipkdb_MD5STEP(F4, c, d, a, b, in[6] + 0xa3014314, 15);
 832         ipkdb_MD5STEP(F4, b, c, d, a, in[13] + 0x4e0811a1, 21);
 833         ipkdb_MD5STEP(F4, a, b, c, d, in[4] + 0xf7537e82, 6);
 834         ipkdb_MD5STEP(F4, d, a, b, c, in[11] + 0xbd3af235, 10);
 835         ipkdb_MD5STEP(F4, c, d, a, b, in[2] + 0x2ad7d2bb, 15);
 836         ipkdb_MD5STEP(F4, b, c, d, a, in[9] + 0xeb86d391, 21);
 837
 838         ctx->buf[0] += a;
 839         ctx->buf[1] += b;
 840         ctx->buf[2] += c;
 841         ctx->buf[3] += d;
 842 }
 843
 844 /*
 845  * Start MD5 accumulation.  Set bit count to 0 and buffer to mysterious
 846  * initialization constants.
 847  */
 848 static void
 849 ipkdb_MD5Init(struct ipkdb_MD5Context *ctx)
 850 {
 851         ctx->buf[0] = 0x67452301;
 852         ctx->buf[1] = 0xefcdab89;
 853         ctx->buf[2] = 0x98badcfe;
 854         ctx->buf[3] = 0x10325476;
 855
 856         ctx->bits[0] = 0;
 857         ctx->bits[1] = 0;
 858 }
 859
 860 /*
 861  * Update context to reflect the concatenation of another buffer full
 862  * of bytes.
 863  */
 864 static void
 865 ipkdb_MD5Update(struct ipkdb_MD5Context *ctx, u_char *buf, unsigned len)
 866 {
 867         u_int t;
 868
 869         /* Update bitcount */
 870         t = ctx->bits[0];
 871         if ((ctx->bits[0] = (t + (len << 3)) & 0xffffffff) < t)
 872                 ctx->bits[1]++; /* Carry from low to high */
 873         ctx->bits[1] += (len >> 29) & 0xffffffff;
 874
 875         t = (t >> 3) & 0x3f;    /* Bytes already in ctx->in */
 876
 877         /* Handle any leading odd-sized chunks */
 878         if (t) {
 879                 u_char *p = ctx->in + t;
 880
 881                 t = 64 - t;
 882                 if (len < t) {
 883                         ipkdbcopy(buf, p, len);
 884                         return;
 885                 }
 886                 ipkdbcopy(buf, p, t);
 887                 ipkdb_MD5Transform(ctx);
 888                 buf += t;
 889                 len -= t;
 890         }
 891
 892         /* Process data in 64-byte chunks */
 893         while (len >= 64) {
 894                 ipkdbcopy(buf, ctx->in, 64);
 895                 ipkdb_MD5Transform(ctx);
 896                 buf += 64;
 897                 len -= 64;
 898         }
 899
 900         /* Handle any remaining bytes of data. */
 901         ipkdbcopy(buf, ctx->in, len);
 902 }
 903
 904 /*
 905  * Final wrapup - pad to 64-byte boundary with the bit pattern
 906  * 1 0* (64-bit count of bits processed, LSB-first)
 907  */
 908 static u_char *
 909 ipkdb_MD5Final(struct ipkdb_MD5Context *ctx)
 910 {
 911         static u_char digest[16];
 912         unsigned count;
 913         u_char *p;
 914
 915         /* Compute number of bytes mod 64 */
 916         count = (ctx->bits[0] >> 3) & 0x3f;
 917
 918         /* Set the first char of padding to 0x80.  This is safe since there is
 919            always at least one byte free */
 920         p = ctx->in + count;
 921         *p++ = 0x80;
 922
 923         /* Bytes of padding needed to make 64 bytes */
 924         count = 64 - 1 - count;
 925
 926         /* Pad out to 56 mod 64 */
 927         if (count < 8) {
 928                 /* Two lots of padding:  Pad the first block to 64 bytes */
 929                 ipkdbzero(p, count);
 930                 ipkdb_MD5Transform(ctx);
 931
 932                 /* Now fill the next block with 56 bytes */
 933                 ipkdbzero(ctx->in, 56);
 934         } else
 935                 /* Pad block to 56 bytes */
 936                 ipkdbzero(p, count - 8);
 937
 938         /* Append length in bits and transform */
 939         setNl(ctx->in + 56, ctx->bits[0]);
 940         setNl(ctx->in + 60, ctx->bits[1]);
 941
 942         ipkdb_MD5Transform(ctx);
 943         setNl(digest, ctx->buf[0]);
 944         setNl(digest + 4, ctx->buf[1]);
 945         setNl(digest + 8, ctx->buf[2]);
 946         setNl(digest + 12, ctx->buf[3]);
 947
 948         return digest;
 949 }
 950
 951 /*
 952  * The following code is more or less stolen from the hmac_md5
 953  * function in the Appendix of the HMAC IETF draft, but is
 954  * optimized as suggested in this same paper.
 955  */
 956 static int
 957 hmac_init(void)
 958 {
 959         char pad[64];
 960         char tk[16];
 961         u_char *key = ipkdbkey;
 962         int key_len = strlen(key);
 963         int i;
 964
 965         /* Require key to be at least 16 bytes long */
 966         if (key_len < 16) {
 967                 printf("IPKDBKEY must be at least 16 bytes long!\n");
 968                 ipkdbzero(key, key_len);                                /* XXX */
 969                 return 0;
 970         }
 971
 972         /* if key is longer than 64 bytes reset it to key=MD5(key) */
 973         if (key_len > 64) {
 974                 ipkdb_MD5Init(&icontext);
 975                 ipkdb_MD5Update(&icontext, key, key_len);
 976                 ipkdbcopy(ipkdb_MD5Final(&icontext), tk, 16);
 977                 ipkdbzero(key, key_len);                                /* XXX */
 978                 key = tk;
 979                 key_len = 16;
 980         }
 981
 982         /*
 983          * the HMAC_MD5 transform looks like:
 984          *
 985          * MD5(K XOR opad, MD5(K XOR ipad, text))
 986          *
 987          * where K is and n byte key
 988          * ipad is the byte 0x36 repeated 64 times
 989          * opad is the byte 0x5c repeated 64 times
 990          * and text is the data being protected
 991          */
 992         /*
 993          * We do the initial part of MD5(K XOR ipad)
 994          * and MD5(K XOR opad) here, in order to
 995          * speed up the computation later on.
 996          */
 997         ipkdbzero(pad, sizeof pad);
 998         ipkdbcopy(key, pad, key_len);
 999         for (i = 0; i < 64; i++)
1000                 pad[i] ^= 0x36;
1001         ipkdb_MD5Init(&icontext);
1002         ipkdb_MD5Update(&icontext, pad, 64);
1003
1004         ipkdbzero(pad, sizeof pad);
1005         ipkdbcopy(key, pad, key_len);
1006         for (i = 0; i < 64; i++)
1007                 pad[i] ^= 0x5c;
1008         ipkdb_MD5Init(&ocontext);
1009         ipkdb_MD5Update(&ocontext, pad, 64);
1010
1011         /* Zero out the key                                             XXX */
1012         ipkdbzero(key, key_len);
1013
1014         return 1;
1015 }
1016
1017 /*
1018  * This is more or less hmac_md5 from the HMAC IETF draft, Appendix.
1019  */
1020 static void *
1021 chksum(void *buf, int len)
1022 {
1023         u_char *digest;
1024         struct ipkdb_MD5Context context;
1025
1026         /*
1027          * the HMAC_MD5 transform looks like:
1028          *
1029          * MD5(K XOR opad, MD5(K XOR ipad, text))
1030          *
1031          * where K is an n byte key
1032          * ipad is the byte 0x36 repeated 64 times
1033          * opad is the byte 0x5c repeated 64 times
1034          * and text is the data being protected
1035          */
1036         /*
1037          * Since we've already done the precomputation,
1038          * we can now stuff the data into the relevant
1039          * preinitialized contexts to get the result.
1040          */
1041         /*
1042          * perform inner MD5
1043          */
1044         ipkdbcopy(&icontext, &context, sizeof context);
1045         ipkdb_MD5Update(&context, buf, len);
1046         digest = ipkdb_MD5Final(&context);
1047         /*
1048          * perform outer MD5
1049          */
1050         ipkdbcopy(&ocontext, &context, sizeof context);
1051         ipkdb_MD5Update(&context, digest, 16);
1052         return ipkdb_MD5Final(&context);
1053 }
1054
1055 static void
1056 getpkt(struct ipkdb_if *ifp, char *buf, int *lp)
1057 {
1058         char *got;
1059         int l;
1060         char _ibuf[ETHERMTU + 16];
1061 #define ibuf    (_ibuf + 2)             /* align ip data in packet */
1062
1063         *lp = 0;
1064         while (1) {
1065                 if (!(got = inpkt(ifp, ibuf, ipkdbpanic != 0))) {
1066                         *lp = 0;
1067                         return;
1068                 }
1069                 if (   ifp->seq == getnl(got)
1070                     && got[6] >= 'A'
1071                     && got[6] <= 'Z'
1072                     && (l = getns(got + 4))
1073                     && !ipkdbcmp(chksum(got, l + 6), got + l + 6, LENCHK)) {
1074                         ipkdbcopy(got + 6, buf, *lp = l);
1075                         return;
1076                 }
1077                 if (   ifp->pktlen
1078                     && ((ifp->flags & (IPKDB_MYIP | IPKDB_HISIP | IPKDB_CONNECTED))
1079                         == (IPKDB_MYIP | IPKDB_HISIP | IPKDB_CONNECTED)))
1080                         outpkt(ifp, ifp->pkt, ifp->pktlen, IPKDBPORT, ifp->hisport);
1081         }
1082 #undef  ibuf
1083 }
1084
1085 static void
1086 putpkt(struct ipkdb_if *ifp, const char *buf, int l)
1087 {
1088         setnl(ifp->pkt, ifp->seq++);
1089         setns(ifp->pkt + 4, l);
1090         ipkdbcopy(buf, ifp->pkt + 6, l);
1091         ipkdbcopy(chksum(ifp->pkt, l + 6), ifp->pkt + 6 + l, LENCHK);
1092         ifp->pktlen = l + 6 + LENCHK;
1093         if (   (ifp->flags & (IPKDB_MYIP | IPKDB_HISIP | IPKDB_CONNECTED))
1094             != (IPKDB_MYIP | IPKDB_HISIP | IPKDB_CONNECTED))
1095                 return;
1096         outpkt(ifp, ifp->pkt, ifp->pktlen, IPKDBPORT, ifp->hisport);
1097 }
1098
1099 static int
1100 check_ipkdb(struct ipkdb_if *ifp, struct in_addr *shost, char *p, int l)
1101 {
1102         u_char hisenet[6];
1103         u_char hisinet[4];
1104         u_int16_t hisport;
1105         char save;
1106
1107 #ifndef IPKDBSECURE
1108         if (kauth_authorize_system(curlwp->l_cred, KAUTH_SYSTEM_DEBUG,
1109             KAUTH_REQ_SYSTEM_DEBUG_IPKDB, NULL, NULL, NULL))
1110                 return 0;
1111 #endif
1112         if (ipkdbcmp(chksum(p, l), p + l, LENCHK))
1113                 return 0;
1114         ipkdbcopy(ifp->hisenetaddr, hisenet, sizeof hisenet);
1115         ipkdbcopy(ifp->hisinetaddr, hisinet, sizeof hisinet);
1116         hisport = ifp->hisport;
1117         save = ifp->flags;
1118         ipkdbcopy(shost, ifp->hisinetaddr, sizeof ifp->hisinetaddr);
1119         ifp->flags &= ~IPKDB_HISHW;
1120         ifp->flags |= IPKDB_HISIP;
1121         if (connectipkdb(ifp, p + 6, l - 6) < 0) {
1122                 ipkdbcopy(hisenet, ifp->hisenetaddr, sizeof ifp->hisenetaddr);
1123                 ipkdbcopy(hisinet, ifp->hisinetaddr, sizeof ifp->hisinetaddr);
1124                 ifp->hisport = hisport;
1125                 ifp->flags = save;
1126                 return 0;
1127         }
1128         return 1;
1129 }
1130
1131 /*
1132  * Should check whether packet came across the correct interface.       XXX
1133  */
1134 int
1135 checkipkdb(struct in_addr *shost, u_short sport, u_short dport, struct mbuf *m, int off, int len)
1136 {
1137         char *p;
1138         int l;
1139         char ibuf[ETHERMTU+50];
1140
1141         if (dport != IPKDBPORT)
1142                 return 0;
1143         if (len > sizeof ibuf)
1144                 return 0;
1145         m_copydata(m, off, len, ibuf);
1146         p = ibuf;
1147         if (getnl(p) || p[6] != 'O')
1148                 return 0;
1149         l = getns(p + 4);
1150         if (l > len - 6 || !check_ipkdb(&ipkdb_if, shost, p, l + 6))
1151                 return 0;
1152         ipkdb_if.hisport = sport;
1153         ipkdb_connect(1);
1154         return 1;
1155 }
1156
1157 static int
1158 connectipkdb(struct ipkdb_if *ifp, char *buf, int l)
1159 {
1160         char *cp;
1161         u_char *ip;
1162
1163         if (*buf != 'O')
1164                 return -1;
1165         if (getnl(buf + 1) == ifp->id)
1166                 /* It's a retry of a connect packet, ignore it */
1167                 return -1;
1168         ip = ifp->hisinetaddr;
1169         printf("debugged by ");
1170         l -= 1 + sizeof(u_int32_t);
1171         for (cp = buf + 1 + sizeof(u_int32_t); --l >= 0; printf("%c", *cp++));
1172         printf(" (%d.%d.%d.%d)\n", ip[0], ip[1], ip[2], ip[3]);
1173         ifp->flags |= IPKDB_CONNECTED;
1174         ifp->seq = 0;
1175         ifp->pktlen = 0;
1176         ifp->id = getnl(buf + 1);
1177         return 0;
1178 }