1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright (c) 1996 - 2001 Brian Somers <brian@Awfulhak.org> 5 * based on work by Toshiharu OHNO <tony-o@iij.ad.jp> 6 * Internet Initiative Japan, Inc (IIJ) 7 * All rights reserved. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28 * SUCH DAMAGE. 29 * 30 * $FreeBSD$ 31 */ 32 33 #include <sys/param.h> 34 #include <sys/socket.h> 35 #include <netinet/in.h> 36 #include <netinet/in_systm.h> 37 #include <netinet/ip.h> 38 #ifndef NOINET6 39 #include <netinet/icmp6.h> 40 #include <netinet/ip6.h> 41 #endif 42 #include <netinet/ip_icmp.h> 43 #include <netinet/udp.h> 44 #include <netinet/tcp.h> 45 #include <sys/un.h> 46 47 #include <errno.h> 48 #include <netdb.h> 49 #include <stdio.h> 50 #include <string.h> 51 #include <termios.h> 52 #include <unistd.h> 53 54 #include "layer.h" 55 #include "proto.h" 56 #include "mbuf.h" 57 #include "log.h" 58 #include "defs.h" 59 #include "timer.h" 60 #include "fsm.h" 61 #include "lqr.h" 62 #include "hdlc.h" 63 #include "throughput.h" 64 #include "iplist.h" 65 #include "slcompress.h" 66 #include "ncpaddr.h" 67 #include "ip.h" 68 #include "ipcp.h" 69 #include "filter.h" 70 #include "descriptor.h" 71 #include "lcp.h" 72 #include "ccp.h" 73 #include "link.h" 74 #include "mp.h" 75 #ifndef NORADIUS 76 #include "radius.h" 77 #endif 78 #include "ipv6cp.h" 79 #include "ncp.h" 80 #include "bundle.h" 81 #include "tun.h" 82 83 84 #define OPCODE_QUERY 0 85 #define OPCODE_IQUERY 1 86 #define OPCODE_STATUS 2 87 88 struct dns_header { 89 u_short id; 90 unsigned qr : 1; 91 unsigned opcode : 4; 92 unsigned aa : 1; 93 unsigned tc : 1; 94 unsigned rd : 1; 95 unsigned ra : 1; 96 unsigned z : 3; 97 unsigned rcode : 4; 98 u_short qdcount; 99 u_short ancount; 100 u_short nscount; 101 u_short arcount; 102 }; 103 104 static const char * 105 dns_Qclass2Txt(u_short qclass) 106 { 107 static char failure[6]; 108 struct { 109 u_short id; 110 const char *txt; 111 } qtxt[] = { 112 /* rfc1035 */ 113 { 1, "IN" }, { 2, "CS" }, { 3, "CH" }, { 4, "HS" }, { 255, "*" } 114 }; 115 unsigned f; 116 117 for (f = 0; f < sizeof qtxt / sizeof *qtxt; f++) 118 if (qtxt[f].id == qclass) 119 return qtxt[f].txt; 120 121 return HexStr(qclass, failure, sizeof failure); 122 } 123 124 static const char * 125 dns_Qtype2Txt(u_short qtype) 126 { 127 static char failure[6]; 128 struct { 129 u_short id; 130 const char *txt; 131 } qtxt[] = { 132 /* rfc1035/rfc1700 */ 133 { 1, "A" }, { 2, "NS" }, { 3, "MD" }, { 4, "MF" }, { 5, "CNAME" }, 134 { 6, "SOA" }, { 7, "MB" }, { 8, "MG" }, { 9, "MR" }, { 10, "NULL" }, 135 { 11, "WKS" }, { 12, "PTR" }, { 13, "HINFO" }, { 14, "MINFO" }, 136 { 15, "MX" }, { 16, "TXT" }, { 17, "RP" }, { 18, "AFSDB" }, 137 { 19, "X25" }, { 20, "ISDN" }, { 21, "RT" }, { 22, "NSAP" }, 138 { 23, "NSAP-PTR" }, { 24, "SIG" }, { 25, "KEY" }, { 26, "PX" }, 139 { 27, "GPOS" }, { 28, "AAAA" }, { 252, "AXFR" }, { 253, "MAILB" }, 140 { 254, "MAILA" }, { 255, "*" } 141 }; 142 unsigned f; 143 144 for (f = 0; f < sizeof qtxt / sizeof *qtxt; f++) 145 if (qtxt[f].id == qtype) 146 return qtxt[f].txt; 147 148 return HexStr(qtype, failure, sizeof failure); 149 } 150 151 static __inline int 152 PortMatch(int op, u_short pport, u_short rport) 153 { 154 switch (op) { 155 case OP_EQ: 156 return pport == rport; 157 case OP_GT: 158 return pport > rport; 159 case OP_LT: 160 return pport < rport; 161 default: 162 return 0; 163 } 164 } 165 166 /* 167 * Return a text string representing the cproto protocol number. 168 * 169 * The purpose of this routine is calculate this result, for 170 * the many times it is needed in FilterCheck, only on demand 171 * (i.e. when the corresponding logging functions are invoked). 172 * 173 * This optimization saves, over the previous implementation, which 174 * calculated prototxt at the beginning of FilterCheck, an 175 * open/read/close system call sequence per packet, approximately 176 * halving the ppp system overhead and reducing the overall (u + s) 177 * time by 38%. 178 * 179 * The caching performed here is just a side effect. 180 */ 181 static const char * 182 prototxt(int cproto) 183 { 184 static int oproto = -1; 185 static char protobuff[16] = "-1"; 186 struct protoent *pe; 187 188 if (cproto == oproto) 189 return protobuff; 190 if ((pe = getprotobynumber(cproto)) == NULL) 191 snprintf(protobuff, sizeof protobuff, "%d", cproto); 192 else 193 snprintf(protobuff, sizeof protobuff, "%s", pe->p_name); 194 oproto = cproto; 195 return (protobuff); 196 } 197 198 /* 199 * Check a packet against the given filter 200 * Returns 0 to accept the packet, non-zero to drop the packet. 201 * If psecs is not NULL, populate it with the timeout associated 202 * with the filter rule matched. 203 * 204 * If filtering is enabled, the initial fragment of a datagram must 205 * contain the complete protocol header, and subsequent fragments 206 * must not attempt to over-write it. 207 * 208 * One (and only one) of pip or pip6 must be set. 209 */ 210 int 211 FilterCheck(const unsigned char *packet, 212 #ifdef NOINET6 213 u_int32_t family __unused, 214 #else 215 u_int32_t family, 216 #endif 217 const struct filter *filter, unsigned *psecs) 218 { 219 int gotinfo; /* true if IP payload decoded */ 220 int cproto; /* IPPROTO_* protocol number if (gotinfo) */ 221 int estab, syn, finrst; /* TCP state flags if (gotinfo) */ 222 u_short sport, dport; /* src, dest port from packet if (gotinfo) */ 223 int n; /* filter rule to process */ 224 int len; /* bytes used in dbuff */ 225 int didname; /* true if filter header printed */ 226 int match; /* true if condition matched */ 227 int mindata; /* minimum data size or zero */ 228 const struct filterent *fp = filter->rule; 229 char dbuff[100], dstip[NCP_ASCIIBUFFERSIZE]; 230 struct ncpaddr srcaddr, dstaddr; 231 const char *payload; /* IP payload */ 232 int datalen; /* IP datagram length */ 233 234 if (fp->f_action == A_NONE) 235 return 0; /* No rule is given. Permit this packet */ 236 237 #ifndef NOINET6 238 if (family == AF_INET6) { 239 const struct ip6_hdr *pip6 = (const struct ip6_hdr *)packet; 240 241 ncpaddr_setip6(&srcaddr, &pip6->ip6_src); 242 ncpaddr_setip6(&dstaddr, &pip6->ip6_dst); 243 datalen = ntohs(pip6->ip6_plen); 244 payload = packet + sizeof *pip6; 245 cproto = pip6->ip6_nxt; 246 } else 247 #endif 248 { 249 /* 250 * Deny any packet fragment that tries to over-write the header. 251 * Since we no longer have the real header available, punt on the 252 * largest normal header - 20 bytes for TCP without options, rounded 253 * up to the next possible fragment boundary. Since the smallest 254 * `legal' MTU is 576, and the smallest recommended MTU is 296, any 255 * fragmentation within this range is dubious at best 256 */ 257 const struct ip *pip = (const struct ip *)packet; 258 259 len = ntohs(pip->ip_off) & IP_OFFMASK; /* fragment offset */ 260 if (len > 0) { /* Not first fragment within datagram */ 261 if (len < (24 >> 3)) { /* don't allow fragment to over-write header */ 262 log_Printf(LogFILTER, " error: illegal header\n"); 263 return 1; 264 } 265 /* permit fragments on in and out filter */ 266 if (!filter->fragok) { 267 log_Printf(LogFILTER, " error: illegal fragmentation\n"); 268 return 1; 269 } else 270 return 0; 271 } 272 273 ncpaddr_setip4(&srcaddr, pip->ip_src); 274 ncpaddr_setip4(&dstaddr, pip->ip_dst); 275 datalen = ntohs(pip->ip_len) - (pip->ip_hl << 2); 276 payload = packet + (pip->ip_hl << 2); 277 cproto = pip->ip_p; 278 } 279 280 281 gotinfo = estab = syn = finrst = didname = 0; 282 sport = dport = 0; 283 284 for (n = 0; n < MAXFILTERS; ) { 285 if (fp->f_action == A_NONE) { 286 n++; 287 fp++; 288 continue; 289 } 290 291 if (!didname) { 292 log_Printf(LogDEBUG, "%s filter:\n", filter->name); 293 didname = 1; 294 } 295 296 match = 0; 297 298 if ((ncprange_family(&fp->f_src) == AF_UNSPEC || 299 ncprange_contains(&fp->f_src, &srcaddr)) && 300 (ncprange_family(&fp->f_dst) == AF_UNSPEC || 301 ncprange_contains(&fp->f_dst, &dstaddr))) { 302 if (fp->f_proto != 0) { 303 if (!gotinfo) { 304 const struct tcphdr *th; 305 const struct udphdr *uh; 306 const struct icmp *ih; 307 #ifndef NOINET6 308 const struct icmp6_hdr *ih6; 309 #endif 310 mindata = 0; 311 sport = dport = 0; 312 estab = syn = finrst = -1; 313 314 switch (cproto) { 315 case IPPROTO_ICMP: 316 mindata = 8; /* ICMP must be at least 8 octets */ 317 ih = (const struct icmp *)payload; 318 sport = ih->icmp_type; 319 if (log_IsKept(LogDEBUG)) 320 snprintf(dbuff, sizeof dbuff, "sport = %d", sport); 321 break; 322 323 #ifndef NOINET6 324 case IPPROTO_ICMPV6: 325 mindata = 8; /* ICMP must be at least 8 octets */ 326 ih6 = (const struct icmp6_hdr *)payload; 327 sport = ih6->icmp6_type; 328 if (log_IsKept(LogDEBUG)) 329 snprintf(dbuff, sizeof dbuff, "sport = %d", sport); 330 break; 331 #endif 332 333 case IPPROTO_IGMP: 334 mindata = 8; /* IGMP uses 8-octet messages */ 335 break; 336 337 #ifdef IPPROTO_GRE 338 case IPPROTO_GRE: 339 mindata = 2; /* GRE uses 2-octet+ messages */ 340 break; 341 #endif 342 #ifdef IPPROTO_OSPFIGP 343 case IPPROTO_OSPFIGP: 344 mindata = 8; /* IGMP uses 8-octet messages */ 345 break; 346 #endif 347 #ifndef NOINET6 348 case IPPROTO_IPV6: 349 mindata = 20; /* RFC2893 Section 3.5: 5 * 32bit words */ 350 break; 351 #endif 352 353 case IPPROTO_UDP: 354 mindata = 8; /* UDP header is 8 octets */ 355 uh = (const struct udphdr *)payload; 356 sport = ntohs(uh->uh_sport); 357 dport = ntohs(uh->uh_dport); 358 if (log_IsKept(LogDEBUG)) 359 snprintf(dbuff, sizeof dbuff, "sport = %d, dport = %d", 360 sport, dport); 361 break; 362 363 case IPPROTO_TCP: 364 th = (const struct tcphdr *)payload; 365 /* 366 * TCP headers are variable length. The following code 367 * ensures that the TCP header length isn't de-referenced if 368 * the datagram is too short 369 */ 370 if (datalen < 20 || datalen < (th->th_off << 2)) { 371 log_Printf(LogFILTER, " error: TCP header incorrect\n"); 372 return 1; 373 } 374 sport = ntohs(th->th_sport); 375 dport = ntohs(th->th_dport); 376 estab = (th->th_flags & TH_ACK); 377 syn = (th->th_flags & TH_SYN); 378 finrst = (th->th_flags & (TH_FIN|TH_RST)); 379 if (log_IsKept(LogDEBUG)) { 380 if (!estab) 381 snprintf(dbuff, sizeof dbuff, 382 "flags = %02x, sport = %d, dport = %d", 383 th->th_flags, sport, dport); 384 else 385 *dbuff = '\0'; 386 } 387 break; 388 default: 389 break; 390 } 391 392 if (datalen < mindata) { 393 log_Printf(LogFILTER, " error: proto %s must be at least" 394 " %d octets\n", prototxt(cproto), mindata); 395 return 1; 396 } 397 398 if (log_IsKept(LogDEBUG)) { 399 if (estab != -1) { 400 len = strlen(dbuff); 401 snprintf(dbuff + len, sizeof dbuff - len, 402 ", estab = %d, syn = %d, finrst = %d", 403 estab, syn, finrst); 404 } 405 log_Printf(LogDEBUG, " Filter: proto = %s, %s\n", 406 prototxt(cproto), dbuff); 407 } 408 gotinfo = 1; 409 } 410 411 if (log_IsKept(LogDEBUG)) { 412 if (fp->f_srcop != OP_NONE) { 413 snprintf(dbuff, sizeof dbuff, ", src %s %d", 414 filter_Op2Nam(fp->f_srcop), fp->f_srcport); 415 len = strlen(dbuff); 416 } else 417 len = 0; 418 if (fp->f_dstop != OP_NONE) { 419 snprintf(dbuff + len, sizeof dbuff - len, 420 ", dst %s %d", filter_Op2Nam(fp->f_dstop), 421 fp->f_dstport); 422 } else if (!len) 423 *dbuff = '\0'; 424 425 log_Printf(LogDEBUG, " rule = %d: Address match, " 426 "check against proto %d%s, action = %s\n", 427 n, fp->f_proto, dbuff, filter_Action2Nam(fp->f_action)); 428 } 429 430 if (cproto == fp->f_proto) { 431 if ((fp->f_srcop == OP_NONE || 432 PortMatch(fp->f_srcop, sport, fp->f_srcport)) && 433 (fp->f_dstop == OP_NONE || 434 PortMatch(fp->f_dstop, dport, fp->f_dstport)) && 435 (fp->f_estab == 0 || estab) && 436 (fp->f_syn == 0 || syn) && 437 (fp->f_finrst == 0 || finrst)) { 438 match = 1; 439 } 440 } 441 } else { 442 /* Address is matched and no protocol specified. Make a decision. */ 443 log_Printf(LogDEBUG, " rule = %d: Address match, action = %s\n", n, 444 filter_Action2Nam(fp->f_action)); 445 match = 1; 446 } 447 } else 448 log_Printf(LogDEBUG, " rule = %d: Address mismatch\n", n); 449 450 if (match != fp->f_invert) { 451 /* Take specified action */ 452 if (fp->f_action < A_NONE) 453 fp = &filter->rule[n = fp->f_action]; 454 else { 455 if (fp->f_action == A_PERMIT) { 456 if (psecs != NULL) 457 *psecs = fp->timeout; 458 if (strcmp(filter->name, "DIAL") == 0) { 459 /* If dial filter then even print out accept packets */ 460 if (log_IsKept(LogFILTER)) { 461 snprintf(dstip, sizeof dstip, "%s", ncpaddr_ntoa(&dstaddr)); 462 log_Printf(LogFILTER, "%sbound rule = %d accept %s " 463 "src = %s:%d dst = %s:%d\n", filter->name, n, 464 prototxt(cproto), ncpaddr_ntoa(&srcaddr), sport, 465 dstip, dport); 466 } 467 } 468 return 0; 469 } else { 470 if (log_IsKept(LogFILTER)) { 471 snprintf(dstip, sizeof dstip, "%s", ncpaddr_ntoa(&dstaddr)); 472 log_Printf(LogFILTER, 473 "%sbound rule = %d deny %s src = %s/%d dst = %s/%d\n", 474 filter->name, n, prototxt(cproto), 475 ncpaddr_ntoa(&srcaddr), sport, dstip, dport); 476 } 477 return 1; 478 } /* Explicit match. Deny this packet */ 479 } 480 } else { 481 n++; 482 fp++; 483 } 484 } 485 486 if (log_IsKept(LogFILTER)) { 487 snprintf(dstip, sizeof dstip, "%s", ncpaddr_ntoa(&dstaddr)); 488 log_Printf(LogFILTER, 489 "%sbound rule = implicit deny %s src = %s/%d dst = %s/%d\n", 490 filter->name, prototxt(cproto), ncpaddr_ntoa(&srcaddr), 491 sport, dstip, dport); 492 } 493 494 return 1; /* No rule matched, deny this packet */ 495 } 496 497 static void 498 ip_LogDNS(const struct udphdr *uh, const char *direction) 499 { 500 struct dns_header header; 501 const u_short *pktptr; 502 const u_char *ptr; 503 u_short *hptr, tmp; 504 unsigned len; 505 506 ptr = (const char *)uh + sizeof *uh; 507 len = ntohs(uh->uh_ulen) - sizeof *uh; 508 if (len < sizeof header + 5) /* rfc1024 */ 509 return; 510 511 pktptr = (const u_short *)ptr; 512 hptr = (u_short *)&header; 513 ptr += sizeof header; 514 len -= sizeof header; 515 516 while (pktptr < (const u_short *)ptr) { 517 *hptr++ = ntohs(*pktptr); /* Careful of macro side-effects ! */ 518 pktptr++; 519 } 520 521 if (header.opcode == OPCODE_QUERY && header.qr == 0) { 522 /* rfc1035 */ 523 char namewithdot[MAXHOSTNAMELEN + 1], *n; 524 const char *qtype, *qclass; 525 const u_char *end; 526 527 n = namewithdot; 528 end = ptr + len - 4; 529 if (end - ptr >= (int)sizeof namewithdot) 530 end = ptr + sizeof namewithdot - 1; 531 while (ptr < end) { 532 len = *ptr++; 533 if ((int)len > end - ptr) 534 len = end - ptr; 535 if (n != namewithdot) 536 *n++ = '.'; 537 memcpy(n, ptr, len); 538 ptr += len; 539 n += len; 540 } 541 *n = '\0'; 542 543 if (log_IsKept(LogDNS)) { 544 memcpy(&tmp, end, sizeof tmp); 545 qtype = dns_Qtype2Txt(ntohs(tmp)); 546 memcpy(&tmp, end + 2, sizeof tmp); 547 qclass = dns_Qclass2Txt(ntohs(tmp)); 548 549 log_Printf(LogDNS, "%sbound query %s %s %s\n", 550 direction, qclass, qtype, namewithdot); 551 } 552 } 553 } 554 555 /* 556 * Check if the given packet matches the given filter. 557 * One of pip or pip6 must be set. 558 */ 559 int 560 PacketCheck(struct bundle *bundle, u_int32_t family, 561 const unsigned char *packet, int nb, struct filter *filter, 562 const char *prefix, unsigned *psecs) 563 { 564 char logbuf[200]; 565 static const char *const TcpFlags[] = { 566 "FIN", "SYN", "RST", "PSH", "ACK", "URG" 567 }; 568 const struct tcphdr *th; 569 const struct udphdr *uh; 570 const struct icmp *icmph; 571 #ifndef NOINET6 572 const struct icmp6_hdr *icmp6h; 573 #endif 574 const unsigned char *payload; 575 struct ncpaddr srcaddr, dstaddr; 576 int cproto, mask, len, n, pri, logit, result, datalen, frag; 577 unsigned loglen; 578 u_char tos; 579 580 logit = (log_IsKept(LogTCPIP) || log_IsKept(LogDNS)) && 581 (!filter || filter->logok); 582 loglen = 0; 583 pri = 0; 584 585 #ifndef NOINET6 586 if (family == AF_INET6) { 587 const struct ip6_hdr *pip6 = (const struct ip6_hdr *)packet; 588 589 ncpaddr_setip6(&srcaddr, &pip6->ip6_src); 590 ncpaddr_setip6(&dstaddr, &pip6->ip6_dst); 591 datalen = ntohs(pip6->ip6_plen); 592 payload = packet + sizeof *pip6; 593 cproto = pip6->ip6_nxt; 594 tos = 0; /* XXX: pip6->ip6_vfc >> 4 ? */ 595 frag = 0; /* XXX: ??? */ 596 } else 597 #endif 598 { 599 const struct ip *pip = (const struct ip *)packet; 600 601 ncpaddr_setip4(&srcaddr, pip->ip_src); 602 ncpaddr_setip4(&dstaddr, pip->ip_dst); 603 datalen = ntohs(pip->ip_len) - (pip->ip_hl << 2); 604 payload = packet + (pip->ip_hl << 2); 605 cproto = pip->ip_p; 606 tos = pip->ip_tos; 607 frag = ntohs(pip->ip_off) & IP_OFFMASK; 608 } 609 610 uh = NULL; 611 612 if (logit && loglen < sizeof logbuf) { 613 if (prefix) 614 snprintf(logbuf + loglen, sizeof logbuf - loglen, "%s", prefix); 615 else if (filter) 616 snprintf(logbuf + loglen, sizeof logbuf - loglen, "%s ", filter->name); 617 else 618 snprintf(logbuf + loglen, sizeof logbuf - loglen, " "); 619 loglen += strlen(logbuf + loglen); 620 } 621 622 switch (cproto) { 623 case IPPROTO_ICMP: 624 if (logit && loglen < sizeof logbuf) { 625 len = datalen - sizeof *icmph; 626 icmph = (const struct icmp *)payload; 627 snprintf(logbuf + loglen, sizeof logbuf - loglen, 628 "ICMP: %s:%d ---> ", ncpaddr_ntoa(&srcaddr), icmph->icmp_type); 629 loglen += strlen(logbuf + loglen); 630 snprintf(logbuf + loglen, sizeof logbuf - loglen, 631 "%s (%d/%d)", ncpaddr_ntoa(&dstaddr), len, nb); 632 loglen += strlen(logbuf + loglen); 633 } 634 break; 635 636 #ifndef NOINET6 637 case IPPROTO_ICMPV6: 638 if (logit && loglen < sizeof logbuf) { 639 len = datalen - sizeof *icmp6h; 640 icmp6h = (const struct icmp6_hdr *)payload; 641 snprintf(logbuf + loglen, sizeof logbuf - loglen, 642 "ICMP: %s:%d ---> ", ncpaddr_ntoa(&srcaddr), icmp6h->icmp6_type); 643 loglen += strlen(logbuf + loglen); 644 snprintf(logbuf + loglen, sizeof logbuf - loglen, 645 "%s (%d/%d)", ncpaddr_ntoa(&dstaddr), len, nb); 646 loglen += strlen(logbuf + loglen); 647 } 648 break; 649 #endif 650 651 case IPPROTO_UDP: 652 uh = (const struct udphdr *)payload; 653 if (tos == IPTOS_LOWDELAY && bundle->ncp.cfg.urgent.tos) 654 pri++; 655 656 if (!frag && ncp_IsUrgentUdpPort(&bundle->ncp, ntohs(uh->uh_sport), 657 ntohs(uh->uh_dport))) 658 pri++; 659 660 if (logit && loglen < sizeof logbuf) { 661 len = datalen - sizeof *uh; 662 snprintf(logbuf + loglen, sizeof logbuf - loglen, 663 "UDP: %s:%d ---> ", ncpaddr_ntoa(&srcaddr), ntohs(uh->uh_sport)); 664 loglen += strlen(logbuf + loglen); 665 snprintf(logbuf + loglen, sizeof logbuf - loglen, 666 "%s:%d (%d/%d)", ncpaddr_ntoa(&dstaddr), ntohs(uh->uh_dport), 667 len, nb); 668 loglen += strlen(logbuf + loglen); 669 } 670 671 if (Enabled(bundle, OPT_FILTERDECAP) && 672 payload[sizeof *uh] == HDLC_ADDR && 673 payload[sizeof *uh + 1] == HDLC_UI) { 674 u_short proto; 675 const char *type; 676 677 memcpy(&proto, payload + sizeof *uh + 2, sizeof proto); 678 type = NULL; 679 680 switch (ntohs(proto)) { 681 case PROTO_IP: 682 snprintf(logbuf + loglen, sizeof logbuf - loglen, " contains "); 683 result = PacketCheck(bundle, AF_INET, payload + sizeof *uh + 4, 684 nb - (payload - packet) - sizeof *uh - 4, filter, 685 logbuf, psecs); 686 if (result != -2) 687 return result; 688 type = "IP"; 689 break; 690 691 case PROTO_VJUNCOMP: type = "compressed VJ"; break; 692 case PROTO_VJCOMP: type = "uncompressed VJ"; break; 693 case PROTO_MP: type = "Multi-link"; break; 694 case PROTO_ICOMPD: type = "Individual link CCP"; break; 695 case PROTO_COMPD: type = "CCP"; break; 696 case PROTO_IPCP: type = "IPCP"; break; 697 case PROTO_LCP: type = "LCP"; break; 698 case PROTO_PAP: type = "PAP"; break; 699 case PROTO_CBCP: type = "CBCP"; break; 700 case PROTO_LQR: type = "LQR"; break; 701 case PROTO_CHAP: type = "CHAP"; break; 702 } 703 if (type) { 704 snprintf(logbuf + loglen, sizeof logbuf - loglen, 705 " - %s data", type); 706 loglen += strlen(logbuf + loglen); 707 } 708 } 709 710 break; 711 712 #ifdef IPPROTO_GRE 713 case IPPROTO_GRE: 714 if (logit && loglen < sizeof logbuf) { 715 snprintf(logbuf + loglen, sizeof logbuf - loglen, 716 "GRE: %s ---> ", ncpaddr_ntoa(&srcaddr)); 717 loglen += strlen(logbuf + loglen); 718 snprintf(logbuf + loglen, sizeof logbuf - loglen, 719 "%s (%d/%d)", ncpaddr_ntoa(&dstaddr), datalen, nb); 720 loglen += strlen(logbuf + loglen); 721 } 722 break; 723 #endif 724 725 #ifdef IPPROTO_OSPFIGP 726 case IPPROTO_OSPFIGP: 727 if (logit && loglen < sizeof logbuf) { 728 snprintf(logbuf + loglen, sizeof logbuf - loglen, 729 "OSPF: %s ---> ", ncpaddr_ntoa(&srcaddr)); 730 loglen += strlen(logbuf + loglen); 731 snprintf(logbuf + loglen, sizeof logbuf - loglen, 732 "%s (%d/%d)", ncpaddr_ntoa(&dstaddr), datalen, nb); 733 loglen += strlen(logbuf + loglen); 734 } 735 break; 736 #endif 737 738 #ifndef NOINET6 739 case IPPROTO_IPV6: 740 if (logit && loglen < sizeof logbuf) { 741 snprintf(logbuf + loglen, sizeof logbuf - loglen, 742 "IPv6: %s ---> ", ncpaddr_ntoa(&srcaddr)); 743 loglen += strlen(logbuf + loglen); 744 snprintf(logbuf + loglen, sizeof logbuf - loglen, 745 "%s (%d/%d)", ncpaddr_ntoa(&dstaddr), datalen, nb); 746 loglen += strlen(logbuf + loglen); 747 } 748 749 if (Enabled(bundle, OPT_FILTERDECAP)) { 750 snprintf(logbuf + loglen, sizeof logbuf - loglen, " contains "); 751 result = PacketCheck(bundle, AF_INET6, payload, nb - (payload - packet), 752 filter, logbuf, psecs); 753 if (result != -2) 754 return result; 755 } 756 break; 757 #endif 758 759 case IPPROTO_IPIP: 760 if (logit && loglen < sizeof logbuf) { 761 snprintf(logbuf + loglen, sizeof logbuf - loglen, 762 "IPIP: %s ---> ", ncpaddr_ntoa(&srcaddr)); 763 loglen += strlen(logbuf + loglen); 764 snprintf(logbuf + loglen, sizeof logbuf - loglen, 765 "%s", ncpaddr_ntoa(&dstaddr)); 766 loglen += strlen(logbuf + loglen); 767 } 768 769 if (Enabled(bundle, OPT_FILTERDECAP) && 770 ((const struct ip *)payload)->ip_v == 4) { 771 snprintf(logbuf + loglen, sizeof logbuf - loglen, " contains "); 772 result = PacketCheck(bundle, AF_INET, payload, nb - (payload - packet), 773 filter, logbuf, psecs); 774 loglen += strlen(logbuf + loglen); 775 if (result != -2) 776 return result; 777 } 778 break; 779 780 case IPPROTO_ESP: 781 if (logit && loglen < sizeof logbuf) { 782 snprintf(logbuf + loglen, sizeof logbuf - loglen, 783 "ESP: %s ---> ", ncpaddr_ntoa(&srcaddr)); 784 loglen += strlen(logbuf + loglen); 785 snprintf(logbuf + loglen, sizeof logbuf - loglen, "%s, spi %p", 786 ncpaddr_ntoa(&dstaddr), payload); 787 loglen += strlen(logbuf + loglen); 788 } 789 break; 790 791 case IPPROTO_AH: 792 if (logit && loglen < sizeof logbuf) { 793 snprintf(logbuf + loglen, sizeof logbuf - loglen, 794 "AH: %s ---> ", ncpaddr_ntoa(&srcaddr)); 795 loglen += strlen(logbuf + loglen); 796 snprintf(logbuf + loglen, sizeof logbuf - loglen, "%s, spi %p", 797 ncpaddr_ntoa(&dstaddr), payload + sizeof(u_int32_t)); 798 loglen += strlen(logbuf + loglen); 799 } 800 break; 801 802 case IPPROTO_IGMP: 803 if (logit && loglen < sizeof logbuf) { 804 uh = (const struct udphdr *)payload; 805 snprintf(logbuf + loglen, sizeof logbuf - loglen, 806 "IGMP: %s:%d ---> ", ncpaddr_ntoa(&srcaddr), 807 ntohs(uh->uh_sport)); 808 loglen += strlen(logbuf + loglen); 809 snprintf(logbuf + loglen, sizeof logbuf - loglen, 810 "%s:%d", ncpaddr_ntoa(&dstaddr), ntohs(uh->uh_dport)); 811 loglen += strlen(logbuf + loglen); 812 } 813 break; 814 815 case IPPROTO_TCP: 816 th = (const struct tcphdr *)payload; 817 if (tos == IPTOS_LOWDELAY && bundle->ncp.cfg.urgent.tos) 818 pri++; 819 820 if (!frag && ncp_IsUrgentTcpPort(&bundle->ncp, ntohs(th->th_sport), 821 ntohs(th->th_dport))) 822 pri++; 823 else if (!frag && ncp_IsUrgentTcpLen(&bundle->ncp, datalen)) 824 pri++; 825 826 if (logit && loglen < sizeof logbuf) { 827 len = datalen - (th->th_off << 2); 828 snprintf(logbuf + loglen, sizeof logbuf - loglen, 829 "TCP: %s:%d ---> ", ncpaddr_ntoa(&srcaddr), ntohs(th->th_sport)); 830 loglen += strlen(logbuf + loglen); 831 snprintf(logbuf + loglen, sizeof logbuf - loglen, 832 "%s:%d", ncpaddr_ntoa(&dstaddr), ntohs(th->th_dport)); 833 loglen += strlen(logbuf + loglen); 834 n = 0; 835 for (mask = TH_FIN; mask != 0x40; mask <<= 1) { 836 if (th->th_flags & mask) { 837 snprintf(logbuf + loglen, sizeof logbuf - loglen, " %s", TcpFlags[n]); 838 loglen += strlen(logbuf + loglen); 839 } 840 n++; 841 } 842 snprintf(logbuf + loglen, sizeof logbuf - loglen, 843 " seq:%lx ack:%lx (%d/%d)", 844 (u_long)ntohl(th->th_seq), (u_long)ntohl(th->th_ack), len, nb); 845 loglen += strlen(logbuf + loglen); 846 if ((th->th_flags & TH_SYN) && nb > 40) { 847 const u_short *sp; 848 849 sp = (const u_short *)(payload + 20); 850 if (ntohs(sp[0]) == 0x0204) { 851 snprintf(logbuf + loglen, sizeof logbuf - loglen, 852 " MSS = %d", ntohs(sp[1])); 853 loglen += strlen(logbuf + loglen); 854 } 855 } 856 snprintf(logbuf + loglen, sizeof logbuf - loglen, " pri:%d", pri); 857 loglen += strlen(logbuf + loglen); 858 } 859 break; 860 861 default: 862 if (prefix) 863 return -2; 864 865 if (logit && loglen < sizeof logbuf) { 866 snprintf(logbuf + loglen, sizeof logbuf - loglen, 867 "<%d>: %s ---> ", cproto, ncpaddr_ntoa(&srcaddr)); 868 loglen += strlen(logbuf + loglen); 869 snprintf(logbuf + loglen, sizeof logbuf - loglen, 870 "%s (%d)", ncpaddr_ntoa(&dstaddr), nb); 871 loglen += strlen(logbuf + loglen); 872 } 873 break; 874 } 875 876 if (filter && FilterCheck(packet, family, filter, psecs)) { 877 if (logit) 878 log_Printf(LogTCPIP, "%s - BLOCKED\n", logbuf); 879 result = -1; 880 } else { 881 /* Check Keep Alive filter */ 882 if (logit && log_IsKept(LogTCPIP)) { 883 unsigned alivesecs; 884 885 alivesecs = 0; 886 if (filter && 887 FilterCheck(packet, family, &bundle->filter.alive, &alivesecs)) 888 log_Printf(LogTCPIP, "%s - NO KEEPALIVE\n", logbuf); 889 else if (psecs != NULL) { 890 if(*psecs == 0) 891 *psecs = alivesecs; 892 if (*psecs) { 893 if (*psecs != alivesecs) 894 log_Printf(LogTCPIP, "%s - (timeout = %d / ALIVE = %d secs)\n", 895 logbuf, *psecs, alivesecs); 896 else 897 log_Printf(LogTCPIP, "%s - (timeout = %d secs)\n", logbuf, *psecs); 898 } else 899 log_Printf(LogTCPIP, "%s\n", logbuf); 900 } 901 } 902 result = pri; 903 } 904 905 if (filter && uh && ntohs(uh->uh_dport) == 53 && log_IsKept(LogDNS)) 906 ip_LogDNS(uh, filter->name); 907 908 return result; 909 } 910 911 static size_t 912 ip_Input(struct bundle *bundle, struct link *l, struct mbuf *bp, u_int32_t af) 913 { 914 ssize_t nw; 915 size_t nb; 916 struct tun_data tun; 917 char *data; 918 unsigned secs, alivesecs; 919 920 nb = m_length(bp); 921 if (nb > sizeof tun.data) { 922 log_Printf(LogWARN, "ip_Input: %s: Packet too large (got %zd, max %d)\n", 923 l->name, nb, (int)(sizeof tun.data)); 924 m_freem(bp); 925 return 0; 926 } 927 mbuf_Read(bp, tun.data, nb); 928 929 secs = 0; 930 if (PacketCheck(bundle, af, tun.data, nb, &bundle->filter.in, 931 NULL, &secs) < 0) 932 return 0; 933 934 alivesecs = 0; 935 if (!FilterCheck(tun.data, af, &bundle->filter.alive, &alivesecs)) { 936 if (secs == 0) 937 secs = alivesecs; 938 bundle_StartIdleTimer(bundle, secs); 939 } 940 941 if (bundle->dev.header) { 942 tun.header.family = htonl(af); 943 nb += sizeof tun - sizeof tun.data; 944 data = (char *)&tun; 945 } else 946 data = tun.data; 947 948 nw = write(bundle->dev.fd, data, nb); 949 if (nw != (ssize_t)nb) { 950 if (nw == -1) 951 log_Printf(LogERROR, "ip_Input: %s: wrote %zd, got %s\n", 952 l->name, nb, strerror(errno)); 953 else 954 log_Printf(LogERROR, "ip_Input: %s: wrote %zd, got %zd\n", l->name, nb, 955 nw); 956 } 957 958 return nb; 959 } 960 961 struct mbuf * 962 ipv4_Input(struct bundle *bundle, struct link *l, struct mbuf *bp) 963 { 964 int nb; 965 966 if (bundle->ncp.ipcp.fsm.state != ST_OPENED) { 967 log_Printf(LogWARN, "ipv4_Input: IPCP not open - packet dropped\n"); 968 m_freem(bp); 969 return NULL; 970 } 971 972 m_settype(bp, MB_IPIN); 973 974 nb = ip_Input(bundle, l, bp, AF_INET); 975 ipcp_AddInOctets(&bundle->ncp.ipcp, nb); 976 977 return NULL; 978 } 979 980 #ifndef NOINET6 981 struct mbuf * 982 ipv6_Input(struct bundle *bundle, struct link *l, struct mbuf *bp) 983 { 984 int nb; 985 986 if (bundle->ncp.ipv6cp.fsm.state != ST_OPENED) { 987 log_Printf(LogWARN, "ipv6_Input: IPV6CP not open - packet dropped\n"); 988 m_freem(bp); 989 return NULL; 990 } 991 992 m_settype(bp, MB_IPV6IN); 993 994 nb = ip_Input(bundle, l, bp, AF_INET6); 995 ipv6cp_AddInOctets(&bundle->ncp.ipv6cp, nb); 996 997 return NULL; 998 } 999 #endif 1000