1 /* 2 * PPP IP Protocol Interface 3 * 4 * Written by Toshiharu OHNO (tony-o@iij.ad.jp) 5 * 6 * Copyright (C) 1993, Internet Initiative Japan, Inc. All rights reserverd. 7 * 8 * Redistribution and use in source and binary forms are permitted 9 * provided that the above copyright notice and this paragraph are 10 * duplicated in all such forms and that any documentation, 11 * advertising materials, and other materials related to such 12 * distribution and use acknowledge that the software was developed 13 * by the Internet Initiative Japan. The name of the 14 * IIJ may not be used to endorse or promote products derived 15 * from this software without specific prior written permission. 16 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR 17 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED 18 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE. 19 * 20 * $FreeBSD$ 21 * 22 * TODO: 23 * o Return ICMP message for filterd packet 24 * and optionaly record it into log. 25 */ 26 #include <sys/param.h> 27 #include <sys/socket.h> 28 #include <netinet/in.h> 29 #include <netinet/in_systm.h> 30 #include <netinet/ip.h> 31 #include <netinet/ip_icmp.h> 32 #include <netinet/udp.h> 33 #include <netinet/tcp.h> 34 #include <arpa/inet.h> 35 #include <sys/un.h> 36 37 #include <errno.h> 38 #include <stdio.h> 39 #include <string.h> 40 #include <termios.h> 41 #include <unistd.h> 42 43 #include "layer.h" 44 #include "proto.h" 45 #include "mbuf.h" 46 #include "log.h" 47 #include "defs.h" 48 #include "timer.h" 49 #include "fsm.h" 50 #include "lqr.h" 51 #include "hdlc.h" 52 #include "throughput.h" 53 #include "iplist.h" 54 #include "slcompress.h" 55 #include "ipcp.h" 56 #include "filter.h" 57 #include "descriptor.h" 58 #include "lcp.h" 59 #include "ccp.h" 60 #include "link.h" 61 #include "mp.h" 62 #ifndef NORADIUS 63 #include "radius.h" 64 #endif 65 #include "bundle.h" 66 #include "tun.h" 67 #include "ip.h" 68 69 70 #define OPCODE_QUERY 0 71 #define OPCODE_IQUERY 1 72 #define OPCODE_STATUS 2 73 74 struct dns_header { 75 u_short id; 76 unsigned qr : 1; 77 unsigned opcode : 4; 78 unsigned aa : 1; 79 unsigned tc : 1; 80 unsigned rd : 1; 81 unsigned ra : 1; 82 unsigned z : 3; 83 unsigned rcode : 4; 84 u_short qdcount; 85 u_short ancount; 86 u_short nscount; 87 u_short arcount; 88 }; 89 90 static const char * 91 dns_Qclass2Txt(u_short qclass) 92 { 93 static char failure[6]; 94 struct { 95 u_short id; 96 const char *txt; 97 } qtxt[] = { 98 /* rfc1035 */ 99 { 1, "IN" }, { 2, "CS" }, { 3, "CH" }, { 4, "HS" }, { 255, "*" } 100 }; 101 int f; 102 103 for (f = 0; f < sizeof qtxt / sizeof *qtxt; f++) 104 if (qtxt[f].id == qclass) 105 return qtxt[f].txt; 106 107 return HexStr(qclass, failure, sizeof failure); 108 } 109 110 static const char * 111 dns_Qtype2Txt(u_short qtype) 112 { 113 static char failure[6]; 114 struct { 115 u_short id; 116 const char *txt; 117 } qtxt[] = { 118 /* rfc1035/rfc1700 */ 119 { 1, "A" }, { 2, "NS" }, { 3, "MD" }, { 4, "MF" }, { 5, "CNAME" }, 120 { 6, "SOA" }, { 7, "MB" }, { 8, "MG" }, { 9, "MR" }, { 10, "NULL" }, 121 { 11, "WKS" }, { 12, "PTR" }, { 13, "HINFO" }, { 14, "MINFO" }, 122 { 15, "MX" }, { 16, "TXT" }, { 17, "RP" }, { 18, "AFSDB" }, 123 { 19, "X25" }, { 20, "ISDN" }, { 21, "RT" }, { 22, "NSAP" }, 124 { 23, "NSAP-PTR" }, { 24, "SIG" }, { 25, "KEY" }, { 26, "PX" }, 125 { 27, "GPOS" }, { 28, "AAAA" }, { 252, "AXFR" }, { 253, "MAILB" }, 126 { 254, "MAILA" }, { 255, "*" } 127 }; 128 int f; 129 130 for (f = 0; f < sizeof qtxt / sizeof *qtxt; f++) 131 if (qtxt[f].id == qtype) 132 return qtxt[f].txt; 133 134 return HexStr(qtype, failure, sizeof failure); 135 } 136 137 static __inline int 138 PortMatch(int op, u_short pport, u_short rport) 139 { 140 switch (op) { 141 case OP_EQ: 142 return pport == rport; 143 case OP_GT: 144 return pport > rport; 145 case OP_LT: 146 return pport < rport; 147 default: 148 return 0; 149 } 150 } 151 152 /* 153 * Check a packet against a defined filter 154 * Returns 0 to accept the packet, non-zero to drop the packet 155 * 156 * If filtering is enabled, the initial fragment of a datagram must 157 * contain the complete protocol header, and subsequent fragments 158 * must not attempt to over-write it. 159 */ 160 static int 161 FilterCheck(const struct ip *pip, const struct filter *filter, unsigned *psecs) 162 { 163 int gotinfo; /* true if IP payload decoded */ 164 int cproto; /* P_* protocol type if (gotinfo) */ 165 int estab, syn, finrst; /* TCP state flags if (gotinfo) */ 166 u_short sport, dport; /* src, dest port from packet if (gotinfo) */ 167 int n; /* filter rule to process */ 168 int len; /* bytes used in dbuff */ 169 int didname; /* true if filter header printed */ 170 int match; /* true if condition matched */ 171 const struct filterent *fp = filter->rule; 172 char dbuff[100], dstip[16]; 173 174 if (fp->f_action == A_NONE) 175 return 0; /* No rule is given. Permit this packet */ 176 177 /* 178 * Deny any packet fragment that tries to over-write the header. 179 * Since we no longer have the real header available, punt on the 180 * largest normal header - 20 bytes for TCP without options, rounded 181 * up to the next possible fragment boundary. Since the smallest 182 * `legal' MTU is 576, and the smallest recommended MTU is 296, any 183 * fragmentation within this range is dubious at best 184 */ 185 len = ntohs(pip->ip_off) & IP_OFFMASK; /* fragment offset */ 186 if (len > 0) { /* Not first fragment within datagram */ 187 if (len < (24 >> 3)) { /* don't allow fragment to over-write header */ 188 log_Printf(LogFILTER, " error: illegal header\n"); 189 return 1; 190 } 191 /* permit fragments on in and out filter */ 192 if (!filter->fragok) { 193 log_Printf(LogFILTER, " error: illegal fragmentation\n"); 194 return 1; 195 } else 196 return 0; 197 } 198 199 cproto = gotinfo = estab = syn = finrst = didname = 0; 200 sport = dport = 0; 201 for (n = 0; n < MAXFILTERS; ) { 202 if (fp->f_action == A_NONE) { 203 n++; 204 fp++; 205 continue; 206 } 207 208 if (!didname) { 209 log_Printf(LogDEBUG, "%s filter:\n", filter->name); 210 didname = 1; 211 } 212 213 match = 0; 214 if (!((pip->ip_src.s_addr ^ fp->f_src.ipaddr.s_addr) & 215 fp->f_src.mask.s_addr) && 216 !((pip->ip_dst.s_addr ^ fp->f_dst.ipaddr.s_addr) & 217 fp->f_dst.mask.s_addr)) { 218 if (fp->f_proto != P_NONE) { 219 if (!gotinfo) { 220 const char *ptop = (const char *) pip + (pip->ip_hl << 2); 221 const struct tcphdr *th; 222 const struct udphdr *uh; 223 const struct icmp *ih; 224 int datalen; /* IP datagram length */ 225 226 datalen = ntohs(pip->ip_len) - (pip->ip_hl << 2); 227 switch (pip->ip_p) { 228 case IPPROTO_ICMP: 229 cproto = P_ICMP; 230 if (datalen < 8) { /* ICMP must be at least 8 octets */ 231 log_Printf(LogFILTER, " error: ICMP must be at least 8 octets\n"); 232 return 1; 233 } 234 235 ih = (const struct icmp *) ptop; 236 sport = ih->icmp_type; 237 estab = syn = finrst = -1; 238 if (log_IsKept(LogDEBUG)) 239 snprintf(dbuff, sizeof dbuff, "sport = %d", sport); 240 break; 241 case IPPROTO_IGMP: 242 cproto = P_IGMP; 243 if (datalen < 8) { /* IGMP uses 8-octet messages */ 244 log_Printf(LogFILTER, " error: IGMP must be at least 8 octets\n"); 245 return 1; 246 } 247 estab = syn = finrst = -1; 248 sport = ntohs(0); 249 break; 250 #ifdef IPPROTO_GRE 251 case IPPROTO_GRE: 252 cproto = P_GRE; 253 if (datalen < 2) { /* GRE uses 2-octet+ messages */ 254 log_Printf(LogFILTER, " error: GRE must be at least 2 octets\n"); 255 return 1; 256 } 257 estab = syn = finrst = -1; 258 sport = ntohs(0); 259 break; 260 #endif 261 #ifdef IPPROTO_OSPFIGP 262 case IPPROTO_OSPFIGP: 263 cproto = P_OSPF; 264 if (datalen < 8) { /* IGMP uses 8-octet messages */ 265 log_Printf(LogFILTER, " error: IGMP must be at least 8 octets\n"); 266 return 1; 267 } 268 estab = syn = finrst = -1; 269 sport = ntohs(0); 270 break; 271 #endif 272 case IPPROTO_ESP: 273 cproto = P_ESP; 274 estab = syn = finrst = -1; 275 sport = ntohs(0); 276 break; 277 case IPPROTO_AH: 278 cproto = P_AH; 279 estab = syn = finrst = -1; 280 sport = ntohs(0); 281 break; 282 case IPPROTO_UDP: 283 case IPPROTO_IPIP: 284 cproto = P_UDP; 285 if (datalen < 8) { /* UDP header is 8 octets */ 286 log_Printf(LogFILTER, " error: UDP must be at least 8 octets\n"); 287 return 1; 288 } 289 290 uh = (const struct udphdr *) ptop; 291 sport = ntohs(uh->uh_sport); 292 dport = ntohs(uh->uh_dport); 293 estab = syn = finrst = -1; 294 if (log_IsKept(LogDEBUG)) 295 snprintf(dbuff, sizeof dbuff, "sport = %d, dport = %d", 296 sport, dport); 297 break; 298 case IPPROTO_TCP: 299 cproto = P_TCP; 300 th = (const struct tcphdr *) ptop; 301 /* TCP headers are variable length. The following code 302 * ensures that the TCP header length isn't de-referenced if 303 * the datagram is too short 304 */ 305 if (datalen < 20 || datalen < (th->th_off << 2)) { 306 log_Printf(LogFILTER, " error: TCP header incorrect\n"); 307 return 1; 308 } 309 sport = ntohs(th->th_sport); 310 dport = ntohs(th->th_dport); 311 estab = (th->th_flags & TH_ACK); 312 syn = (th->th_flags & TH_SYN); 313 finrst = (th->th_flags & (TH_FIN|TH_RST)); 314 if (log_IsKept(LogDEBUG)) { 315 if (!estab) 316 snprintf(dbuff, sizeof dbuff, 317 "flags = %02x, sport = %d, dport = %d", 318 th->th_flags, sport, dport); 319 else 320 *dbuff = '\0'; 321 } 322 break; 323 default: 324 log_Printf(LogFILTER, " error: unknown protocol\n"); 325 return 1; /* We'll block unknown type of packet */ 326 } 327 328 if (log_IsKept(LogDEBUG)) { 329 if (estab != -1) { 330 len = strlen(dbuff); 331 snprintf(dbuff + len, sizeof dbuff - len, 332 ", estab = %d, syn = %d, finrst = %d", 333 estab, syn, finrst); 334 } 335 log_Printf(LogDEBUG, " Filter: proto = %s, %s\n", 336 filter_Proto2Nam(cproto), dbuff); 337 } 338 gotinfo = 1; 339 } 340 if (log_IsKept(LogDEBUG)) { 341 if (fp->f_srcop != OP_NONE) { 342 snprintf(dbuff, sizeof dbuff, ", src %s %d", 343 filter_Op2Nam(fp->f_srcop), fp->f_srcport); 344 len = strlen(dbuff); 345 } else 346 len = 0; 347 if (fp->f_dstop != OP_NONE) { 348 snprintf(dbuff + len, sizeof dbuff - len, 349 ", dst %s %d", filter_Op2Nam(fp->f_dstop), 350 fp->f_dstport); 351 } else if (!len) 352 *dbuff = '\0'; 353 354 log_Printf(LogDEBUG, " rule = %d: Address match, " 355 "check against proto %s%s, action = %s\n", 356 n, filter_Proto2Nam(fp->f_proto), 357 dbuff, filter_Action2Nam(fp->f_action)); 358 } 359 360 if (cproto == fp->f_proto) { 361 if ((fp->f_srcop == OP_NONE || 362 PortMatch(fp->f_srcop, sport, fp->f_srcport)) && 363 (fp->f_dstop == OP_NONE || 364 PortMatch(fp->f_dstop, dport, fp->f_dstport)) && 365 (fp->f_estab == 0 || estab) && 366 (fp->f_syn == 0 || syn) && 367 (fp->f_finrst == 0 || finrst)) { 368 match = 1; 369 } 370 } 371 } else { 372 /* Address is matched and no protocol specified. Make a decision. */ 373 log_Printf(LogDEBUG, " rule = %d: Address match, action = %s\n", n, 374 filter_Action2Nam(fp->f_action)); 375 match = 1; 376 } 377 } else 378 log_Printf(LogDEBUG, " rule = %d: Address mismatch\n", n); 379 380 if (match != fp->f_invert) { 381 /* Take specified action */ 382 if (fp->f_action < A_NONE) 383 fp = &filter->rule[n = fp->f_action]; 384 else { 385 if (fp->f_action == A_PERMIT) { 386 if (psecs != NULL) 387 *psecs = fp->timeout; 388 if (strcmp(filter->name, "DIAL") == 0) { 389 /* If dial filter then even print out accept packets */ 390 if (log_IsKept(LogFILTER)) { 391 snprintf(dstip, sizeof dstip, "%s", inet_ntoa(pip->ip_dst)); 392 log_Printf(LogFILTER, "%sbound rule = %d accept %s " 393 "src = %s/%d dst = %s/%d\n", 394 filter->name, n, filter_Proto2Nam(cproto), 395 inet_ntoa(pip->ip_src), sport, dstip, dport); 396 } 397 } 398 return 0; 399 } else { 400 if (log_IsKept(LogFILTER)) { 401 snprintf(dstip, sizeof dstip, "%s", inet_ntoa(pip->ip_dst)); 402 log_Printf(LogFILTER, 403 "%sbound rule = %d deny %s src = %s/%d dst = %s/%d\n", 404 filter->name, n, filter_Proto2Nam(cproto), 405 inet_ntoa(pip->ip_src), sport, dstip, dport); 406 } 407 return 1; 408 } /* Explict math. Deny this packet */ 409 } 410 } else { 411 n++; 412 fp++; 413 } 414 } 415 416 if (log_IsKept(LogFILTER)) { 417 snprintf(dstip, sizeof dstip, "%s", inet_ntoa(pip->ip_dst)); 418 log_Printf(LogFILTER, 419 "%sbound rule = implicit deny %s src = %s/%d dst = %s/%d\n", 420 filter->name, filter_Proto2Nam(cproto), 421 inet_ntoa(pip->ip_src), sport, dstip, dport); 422 } 423 424 return 1; /* No rule is mached. Deny this packet */ 425 } 426 427 #ifdef notdef 428 static void 429 IcmpError(struct ip *pip, int code) 430 { 431 struct mbuf *bp; 432 433 if (pip->ip_p != IPPROTO_ICMP) { 434 bp = m_get(m_len, MB_IPIN); 435 memcpy(MBUF_CTOP(bp), ptr, m_len); 436 vj_SendFrame(bp); 437 ipcp_AddOutOctets(m_len); 438 } 439 } 440 #endif 441 442 static void 443 ip_LogDNS(const struct udphdr *uh, const char *direction) 444 { 445 struct dns_header header; 446 const u_short *pktptr; 447 const u_char *ptr; 448 u_short *hptr; 449 int len; 450 451 ptr = (const char *)uh + sizeof *uh; 452 len = ntohs(uh->uh_ulen) - sizeof *uh; 453 if (len < sizeof header + 5) /* rfc1024 */ 454 return; 455 456 pktptr = (const u_short *)ptr; 457 hptr = (u_short *)&header; 458 ptr += sizeof header; 459 len -= sizeof header; 460 461 while (pktptr < (const u_short *)ptr) { 462 *hptr++ = ntohs(*pktptr); /* Careful of macro side-effects ! */ 463 pktptr++; 464 } 465 466 if (header.opcode == OPCODE_QUERY && header.qr == 0) { 467 /* rfc1035 */ 468 char name[MAXHOSTNAMELEN + 1], *n; 469 const char *qtype, *qclass; 470 const u_char *end; 471 472 n = name; 473 end = ptr + len - 4; 474 if (end - ptr >= sizeof name) 475 end = ptr + sizeof name - 1; 476 while (ptr < end) { 477 len = *ptr++; 478 if (len > end - ptr) 479 len = end - ptr; 480 if (n != name) 481 *n++ = '.'; 482 memcpy(n, ptr, len); 483 ptr += len; 484 n += len; 485 } 486 *n = '\0'; 487 qtype = dns_Qtype2Txt(ntohs(*(const u_short *)end)); 488 qclass = dns_Qclass2Txt(ntohs(*(const u_short *)(end + 2))); 489 490 log_Printf(LogDNS, "%sbound query %s %s %s\n", 491 direction, qclass, qtype, name); 492 } 493 } 494 495 /* 496 * For debugging aid. 497 */ 498 int 499 PacketCheck(struct bundle *bundle, unsigned char *cp, int nb, 500 struct filter *filter, const char *prefix, unsigned *psecs) 501 { 502 static const char *const TcpFlags[] = { 503 "FIN", "SYN", "RST", "PSH", "ACK", "URG" 504 }; 505 struct ip *pip; 506 struct tcphdr *th; 507 struct udphdr *uh; 508 struct icmp *icmph; 509 unsigned char *ptop; 510 int mask, len, n, pri, logit, loglen, result; 511 char logbuf[200]; 512 513 logit = (log_IsKept(LogTCPIP) || log_IsKept(LogDNS)) && 514 (!filter || filter->logok); 515 loglen = 0; 516 pri = 0; 517 518 pip = (struct ip *)cp; 519 uh = NULL; 520 521 if (logit && loglen < sizeof logbuf) { 522 if (prefix) 523 snprintf(logbuf + loglen, sizeof logbuf - loglen, "%s", prefix); 524 else if (filter) 525 snprintf(logbuf + loglen, sizeof logbuf - loglen, "%s ", filter->name); 526 else 527 snprintf(logbuf + loglen, sizeof logbuf - loglen, " "); 528 loglen += strlen(logbuf + loglen); 529 } 530 ptop = (cp + (pip->ip_hl << 2)); 531 532 switch (pip->ip_p) { 533 case IPPROTO_ICMP: 534 if (logit && loglen < sizeof logbuf) { 535 len = ntohs(pip->ip_len) - (pip->ip_hl << 2) - sizeof *icmph; 536 icmph = (struct icmp *) ptop; 537 snprintf(logbuf + loglen, sizeof logbuf - loglen, 538 "ICMP: %s:%d ---> ", inet_ntoa(pip->ip_src), icmph->icmp_type); 539 loglen += strlen(logbuf + loglen); 540 snprintf(logbuf + loglen, sizeof logbuf - loglen, 541 "%s:%d (%d/%d)", inet_ntoa(pip->ip_dst), icmph->icmp_type, 542 len, nb); 543 loglen += strlen(logbuf + loglen); 544 } 545 break; 546 547 case IPPROTO_UDP: 548 uh = (struct udphdr *) ptop; 549 if (pip->ip_tos == IPTOS_LOWDELAY && bundle->ncp.ipcp.cfg.urgent.tos) 550 pri++; 551 552 if ((ntohs(pip->ip_off) & IP_OFFMASK) == 0 && 553 ipcp_IsUrgentUdpPort(&bundle->ncp.ipcp, ntohs(uh->uh_sport), 554 ntohs(uh->uh_dport))) 555 pri++; 556 557 if (logit && loglen < sizeof logbuf) { 558 len = ntohs(pip->ip_len) - (pip->ip_hl << 2) - sizeof *uh; 559 snprintf(logbuf + loglen, sizeof logbuf - loglen, 560 "UDP: %s:%d ---> ", inet_ntoa(pip->ip_src), ntohs(uh->uh_sport)); 561 loglen += strlen(logbuf + loglen); 562 snprintf(logbuf + loglen, sizeof logbuf - loglen, 563 "%s:%d (%d/%d)", inet_ntoa(pip->ip_dst), ntohs(uh->uh_dport), 564 len, nb); 565 loglen += strlen(logbuf + loglen); 566 } 567 568 if (Enabled(bundle, OPT_FILTERDECAP) && 569 ptop[sizeof *uh] == HDLC_ADDR && ptop[sizeof *uh + 1] == HDLC_UI) { 570 u_short proto; 571 const char *type; 572 573 memcpy(&proto, ptop + sizeof *uh + 2, sizeof proto); 574 type = NULL; 575 576 switch (ntohs(proto)) { 577 case PROTO_IP: 578 snprintf(logbuf + loglen, sizeof logbuf - loglen, " contains "); 579 result = PacketCheck(bundle, ptop + sizeof *uh + 4, 580 nb - (ptop - cp) - sizeof *uh - 4, filter, 581 logbuf, psecs); 582 if (result != -2) 583 return result; 584 type = "IP"; 585 break; 586 587 case PROTO_VJUNCOMP: type = "compressed VJ"; break; 588 case PROTO_VJCOMP: type = "uncompressed VJ"; break; 589 case PROTO_MP: type = "Multi-link"; break; 590 case PROTO_ICOMPD: type = "Individual link CCP"; break; 591 case PROTO_COMPD: type = "CCP"; break; 592 case PROTO_IPCP: type = "IPCP"; break; 593 case PROTO_LCP: type = "LCP"; break; 594 case PROTO_PAP: type = "PAP"; break; 595 case PROTO_CBCP: type = "CBCP"; break; 596 case PROTO_LQR: type = "LQR"; break; 597 case PROTO_CHAP: type = "CHAP"; break; 598 } 599 if (type) { 600 snprintf(logbuf + loglen, sizeof logbuf - loglen, 601 " - %s data", type); 602 loglen += strlen(logbuf + loglen); 603 } 604 } 605 606 break; 607 608 #ifdef IPPROTO_GRE 609 case IPPROTO_GRE: 610 if (logit && loglen < sizeof logbuf) { 611 len = ntohs(pip->ip_len) - (pip->ip_hl << 2); 612 snprintf(logbuf + loglen, sizeof logbuf - loglen, 613 "GRE: %s ---> ", inet_ntoa(pip->ip_src)); 614 loglen += strlen(logbuf + loglen); 615 snprintf(logbuf + loglen, sizeof logbuf - loglen, 616 "%s (%d/%d)", inet_ntoa(pip->ip_dst), len, nb); 617 loglen += strlen(logbuf + loglen); 618 } 619 break; 620 #endif 621 622 #ifdef IPPROTO_OSPFIGP 623 case IPPROTO_OSPFIGP: 624 if (logit && loglen < sizeof logbuf) { 625 len = ntohs(pip->ip_len) - (pip->ip_hl << 2); 626 snprintf(logbuf + loglen, sizeof logbuf - loglen, 627 "OSPF: %s ---> ", inet_ntoa(pip->ip_src)); 628 loglen += strlen(logbuf + loglen); 629 snprintf(logbuf + loglen, sizeof logbuf - loglen, 630 "%s (%d/%d)", inet_ntoa(pip->ip_dst), len, nb); 631 loglen += strlen(logbuf + loglen); 632 } 633 break; 634 #endif 635 636 case IPPROTO_IPIP: 637 if (logit && loglen < sizeof logbuf) { 638 uh = (struct udphdr *) ptop; 639 snprintf(logbuf + loglen, sizeof logbuf - loglen, 640 "IPIP: %s:%d ---> ", inet_ntoa(pip->ip_src), 641 ntohs(uh->uh_sport)); 642 loglen += strlen(logbuf + loglen); 643 snprintf(logbuf + loglen, sizeof logbuf - loglen, 644 "%s:%d", inet_ntoa(pip->ip_dst), ntohs(uh->uh_dport)); 645 loglen += strlen(logbuf + loglen); 646 } 647 break; 648 649 case IPPROTO_ESP: 650 if (logit && loglen < sizeof logbuf) { 651 snprintf(logbuf + loglen, sizeof logbuf - loglen, 652 "ESP: %s ---> ", inet_ntoa(pip->ip_src)); 653 loglen += strlen(logbuf + loglen); 654 snprintf(logbuf + loglen, sizeof logbuf - loglen, "%s, spi %p", 655 inet_ntoa(pip->ip_dst), ptop); 656 loglen += strlen(logbuf + loglen); 657 } 658 break; 659 660 case IPPROTO_AH: 661 if (logit && loglen < sizeof logbuf) { 662 snprintf(logbuf + loglen, sizeof logbuf - loglen, 663 "AH: %s ---> ", inet_ntoa(pip->ip_src)); 664 loglen += strlen(logbuf + loglen); 665 snprintf(logbuf + loglen, sizeof logbuf - loglen, "%s, spi %p", 666 inet_ntoa(pip->ip_dst), ptop + sizeof(u_int32_t)); 667 loglen += strlen(logbuf + loglen); 668 } 669 break; 670 671 case IPPROTO_IGMP: 672 if (logit && loglen < sizeof logbuf) { 673 uh = (struct udphdr *) ptop; 674 snprintf(logbuf + loglen, sizeof logbuf - loglen, 675 "IGMP: %s:%d ---> ", inet_ntoa(pip->ip_src), 676 ntohs(uh->uh_sport)); 677 loglen += strlen(logbuf + loglen); 678 snprintf(logbuf + loglen, sizeof logbuf - loglen, 679 "%s:%d", inet_ntoa(pip->ip_dst), ntohs(uh->uh_dport)); 680 loglen += strlen(logbuf + loglen); 681 } 682 break; 683 684 case IPPROTO_TCP: 685 th = (struct tcphdr *) ptop; 686 if (pip->ip_tos == IPTOS_LOWDELAY && bundle->ncp.ipcp.cfg.urgent.tos) 687 pri++; 688 689 if ((ntohs(pip->ip_off) & IP_OFFMASK) == 0 && 690 ipcp_IsUrgentTcpPort(&bundle->ncp.ipcp, ntohs(th->th_sport), 691 ntohs(th->th_dport))) 692 pri++; 693 694 if (logit && loglen < sizeof logbuf) { 695 len = ntohs(pip->ip_len) - (pip->ip_hl << 2) - (th->th_off << 2); 696 snprintf(logbuf + loglen, sizeof logbuf - loglen, 697 "TCP: %s:%d ---> ", inet_ntoa(pip->ip_src), ntohs(th->th_sport)); 698 loglen += strlen(logbuf + loglen); 699 snprintf(logbuf + loglen, sizeof logbuf - loglen, 700 "%s:%d", inet_ntoa(pip->ip_dst), ntohs(th->th_dport)); 701 loglen += strlen(logbuf + loglen); 702 n = 0; 703 for (mask = TH_FIN; mask != 0x40; mask <<= 1) { 704 if (th->th_flags & mask) { 705 snprintf(logbuf + loglen, sizeof logbuf - loglen, " %s", TcpFlags[n]); 706 loglen += strlen(logbuf + loglen); 707 } 708 n++; 709 } 710 snprintf(logbuf + loglen, sizeof logbuf - loglen, 711 " seq:%lx ack:%lx (%d/%d)", 712 (u_long)ntohl(th->th_seq), (u_long)ntohl(th->th_ack), len, nb); 713 loglen += strlen(logbuf + loglen); 714 if ((th->th_flags & TH_SYN) && nb > 40) { 715 u_short *sp; 716 717 ptop += 20; 718 sp = (u_short *) ptop; 719 if (ntohs(sp[0]) == 0x0204) { 720 snprintf(logbuf + loglen, sizeof logbuf - loglen, 721 " MSS = %d", ntohs(sp[1])); 722 loglen += strlen(logbuf + loglen); 723 } 724 } 725 } 726 break; 727 728 default: 729 if (prefix) 730 return -2; 731 } 732 733 if (filter && FilterCheck(pip, filter, psecs)) { 734 if (logit) 735 log_Printf(LogTCPIP, "%s - BLOCKED\n", logbuf); 736 #ifdef notdef 737 if (direction == 0) 738 IcmpError(pip, pri); 739 #endif 740 result = -1; 741 } else { 742 /* Check Keep Alive filter */ 743 if (logit && log_IsKept(LogTCPIP)) { 744 unsigned alivesecs; 745 746 alivesecs = 0; 747 if (filter && FilterCheck(pip, &bundle->filter.alive, &alivesecs)) 748 log_Printf(LogTCPIP, "%s - NO KEEPALIVE\n", logbuf); 749 else if (psecs != NULL) { 750 if(*psecs == 0) 751 *psecs = alivesecs; 752 if (*psecs) { 753 if (*psecs != alivesecs) 754 log_Printf(LogTCPIP, "%s - (timeout = %d / ALIVE = %d secs)\n", 755 logbuf, *psecs, alivesecs); 756 else 757 log_Printf(LogTCPIP, "%s - (timeout = %d secs)\n", logbuf, *psecs); 758 } else 759 log_Printf(LogTCPIP, "%s\n", logbuf); 760 } 761 } 762 result = pri; 763 } 764 765 if (filter && uh && ntohs(uh->uh_dport) == 53 && log_IsKept(LogDNS)) 766 ip_LogDNS(uh, filter->name); 767 768 return result; 769 } 770 771 struct mbuf * 772 ip_Input(struct bundle *bundle, struct link *l, struct mbuf *bp) 773 { 774 int nb, nw; 775 struct tun_data tun; 776 struct ip *pip; 777 char *data; 778 unsigned secs, alivesecs; 779 780 if (bundle->ncp.ipcp.fsm.state != ST_OPENED) { 781 log_Printf(LogWARN, "ip_Input: IPCP not open - packet dropped\n"); 782 m_freem(bp); 783 return NULL; 784 } 785 786 m_settype(bp, MB_IPIN); 787 nb = m_length(bp); 788 if (nb > sizeof tun.data) { 789 log_Printf(LogWARN, "ip_Input: %s: Packet too large (got %d, max %d)\n", 790 l->name, nb, (int)(sizeof tun.data)); 791 m_freem(bp); 792 return NULL; 793 } 794 mbuf_Read(bp, tun.data, nb); 795 796 secs = 0; 797 if (PacketCheck(bundle, tun.data, nb, &bundle->filter.in, NULL, &secs) < 0) 798 return NULL; 799 800 pip = (struct ip *)tun.data; 801 alivesecs = 0; 802 if (!FilterCheck(pip, &bundle->filter.alive, &alivesecs)) { 803 if (secs == 0) 804 secs = alivesecs; 805 bundle_StartIdleTimer(bundle, secs); 806 } 807 808 ipcp_AddInOctets(&bundle->ncp.ipcp, nb); 809 810 if (bundle->dev.header) { 811 tun.header.family = htonl(AF_INET); 812 nb += sizeof tun - sizeof tun.data; 813 data = (char *)&tun; 814 } else 815 data = tun.data; 816 817 nw = write(bundle->dev.fd, data, nb); 818 if (nw != nb) { 819 if (nw == -1) 820 log_Printf(LogERROR, "ip_Input: %s: wrote %d, got %s\n", 821 l->name, nb, strerror(errno)); 822 else 823 log_Printf(LogERROR, "ip_Input: %s: wrote %d, got %d\n", l->name, nb, nw); 824 } 825 826 return NULL; 827 } 828 829 void 830 ip_Enqueue(struct ipcp *ipcp, int pri, char *ptr, int count) 831 { 832 struct mbuf *bp; 833 834 if (pri < 0 || pri >= IPCP_QUEUES(ipcp)) 835 log_Printf(LogERROR, "Can't store in ip queue %d\n", pri); 836 else { 837 /* 838 * We allocate an extra 6 bytes, four at the front and two at the end. 839 * This is an optimisation so that we need to do less work in 840 * m_prepend() in acf_LayerPush() and proto_LayerPush() and 841 * appending in hdlc_LayerPush(). 842 */ 843 bp = m_get(count + 6, MB_IPOUT); 844 bp->m_offset += 4; 845 bp->m_len -= 6; 846 memcpy(MBUF_CTOP(bp), ptr, count); 847 m_enqueue(ipcp->Queue + pri, bp); 848 } 849 } 850 851 void 852 ip_DeleteQueue(struct ipcp *ipcp) 853 { 854 struct mqueue *queue; 855 856 for (queue = ipcp->Queue; queue < ipcp->Queue + IPCP_QUEUES(ipcp); queue++) 857 while (queue->top) 858 m_freem(m_dequeue(queue)); 859 } 860 861 size_t 862 ip_QueueLen(struct ipcp *ipcp) 863 { 864 struct mqueue *queue; 865 size_t result; 866 867 result = 0; 868 for (queue = ipcp->Queue; queue < ipcp->Queue + IPCP_QUEUES(ipcp); queue++) 869 result += queue->len; 870 871 return result; 872 } 873 874 int 875 ip_PushPacket(struct link *l, struct bundle *bundle) 876 { 877 struct ipcp *ipcp = &bundle->ncp.ipcp; 878 struct mqueue *queue; 879 struct mbuf *bp; 880 struct ip *pip; 881 int m_len; 882 u_int32_t secs = 0; 883 unsigned alivesecs = 0; 884 885 if (ipcp->fsm.state != ST_OPENED) 886 return 0; 887 888 queue = ipcp->Queue + IPCP_QUEUES(ipcp) - 1; 889 do { 890 if (queue->top) { 891 bp = m_dequeue(queue); 892 bp = mbuf_Read(bp, &secs, sizeof secs); 893 bp = m_pullup(bp); 894 m_len = m_length(bp); 895 pip = (struct ip *)MBUF_CTOP(bp); 896 if (!FilterCheck(pip, &bundle->filter.alive, &alivesecs)) { 897 if (secs == 0) 898 secs = alivesecs; 899 bundle_StartIdleTimer(bundle, secs); 900 } 901 link_PushPacket(l, bp, bundle, 0, PROTO_IP); 902 ipcp_AddOutOctets(ipcp, m_len); 903 return 1; 904 } 905 } while (queue-- != ipcp->Queue); 906 907 return 0; 908 } 909