filter.c revision 46686
1/* 2 * PPP Filter command 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 * $Id: filter.c,v 1.27 1999/01/28 01:56:31 brian Exp $ 21 * 22 * TODO: Shoud send ICMP error message when we discard packets. 23 */ 24 25#include <sys/param.h> 26#include <netinet/in.h> 27#include <arpa/inet.h> 28#include <netdb.h> 29#include <netinet/in_systm.h> 30#include <netinet/ip.h> 31#include <sys/un.h> 32 33#include <stdio.h> 34#include <stdlib.h> 35#include <strings.h> 36#include <termios.h> 37 38#include "layer.h" 39#include "defs.h" 40#include "command.h" 41#include "mbuf.h" 42#include "log.h" 43#include "iplist.h" 44#include "timer.h" 45#include "throughput.h" 46#include "lqr.h" 47#include "hdlc.h" 48#include "fsm.h" 49#include "lcp.h" 50#include "ccp.h" 51#include "link.h" 52#include "slcompress.h" 53#include "ipcp.h" 54#include "filter.h" 55#include "descriptor.h" 56#include "prompt.h" 57#include "mp.h" 58#ifndef NORADIUS 59#include "radius.h" 60#endif 61#include "bundle.h" 62 63static int filter_Nam2Proto(int, char const *const *); 64static int filter_Nam2Op(const char *); 65 66static const u_int32_t netmasks[33] = { 67 0x00000000, 68 0x80000000, 0xC0000000, 0xE0000000, 0xF0000000, 69 0xF8000000, 0xFC000000, 0xFE000000, 0xFF000000, 70 0xFF800000, 0xFFC00000, 0xFFE00000, 0xFFF00000, 71 0xFFF80000, 0xFFFC0000, 0xFFFE0000, 0xFFFF0000, 72 0xFFFF8000, 0xFFFFC000, 0xFFFFE000, 0xFFFFF000, 73 0xFFFFF800, 0xFFFFFC00, 0xFFFFFE00, 0xFFFFFF00, 74 0xFFFFFF80, 0xFFFFFFC0, 0xFFFFFFE0, 0xFFFFFFF0, 75 0xFFFFFFF8, 0xFFFFFFFC, 0xFFFFFFFE, 0xFFFFFFFF, 76}; 77 78struct in_addr 79bits2mask(int bits) 80{ 81 struct in_addr result; 82 83 result.s_addr = htonl(netmasks[bits]); 84 return result; 85} 86 87int 88ParseAddr(struct ipcp *ipcp, const char *data, 89 struct in_addr *paddr, struct in_addr *pmask, int *pwidth) 90{ 91 int bits, len; 92 char *wp; 93 const char *cp; 94 95 if (pmask) 96 pmask->s_addr = INADDR_BROADCAST; /* Assume 255.255.255.255 as default */ 97 98 cp = pmask || pwidth ? strchr(data, '/') : NULL; 99 len = cp ? cp - data : strlen(data); 100 101 if (ipcp && strncasecmp(data, "HISADDR", len) == 0) 102 *paddr = ipcp->peer_ip; 103 else if (ipcp && strncasecmp(data, "MYADDR", len) == 0) 104 *paddr = ipcp->my_ip; 105 else if (len > 15) 106 log_Printf(LogWARN, "ParseAddr: %s: Bad address\n", data); 107 else { 108 char s[16]; 109 strncpy(s, data, len); 110 s[len] = '\0'; 111 if (inet_aton(s, paddr) == 0) { 112 log_Printf(LogWARN, "ParseAddr: %s: Bad address\n", s); 113 return (0); 114 } 115 } 116 if (cp && *++cp) { 117 bits = strtol(cp, &wp, 0); 118 if (cp == wp || bits < 0 || bits > 32) { 119 log_Printf(LogWARN, "ParseAddr: bad mask width.\n"); 120 return (0); 121 } 122 } else if (paddr->s_addr == INADDR_ANY) 123 /* An IP of 0.0.0.0 without a width is anything */ 124 bits = 0; 125 else 126 /* If a valid IP is given without a width, assume 32 bits */ 127 bits = 32; 128 129 if (pwidth) 130 *pwidth = bits; 131 132 if (pmask) { 133 if (paddr->s_addr == INADDR_ANY) 134 pmask->s_addr = INADDR_ANY; 135 else 136 *pmask = bits2mask(bits); 137 } 138 139 return (1); 140} 141 142static int 143ParsePort(const char *service, int proto) 144{ 145 const char *protocol_name; 146 char *cp; 147 struct servent *servent; 148 int port; 149 150 switch (proto) { 151 case P_UDP: 152 protocol_name = "udp"; 153 break; 154 case P_TCP: 155 protocol_name = "tcp"; 156 break; 157 default: 158 protocol_name = 0; 159 } 160 161 servent = getservbyname(service, protocol_name); 162 if (servent != 0) 163 return (ntohs(servent->s_port)); 164 165 port = strtol(service, &cp, 0); 166 if (cp == service) { 167 log_Printf(LogWARN, "ParsePort: %s is not a port name or number.\n", 168 service); 169 return (0); 170 } 171 return (port); 172} 173 174/* 175 * ICMP Syntax: src eq icmp_message_type 176 */ 177static int 178ParseIcmp(int argc, char const *const *argv, struct filterent *tgt) 179{ 180 int type; 181 char *cp; 182 183 switch (argc) { 184 case 0: 185 /* permit/deny all ICMP types */ 186 tgt->opt.srcop = OP_NONE; 187 break; 188 189 case 3: 190 if (!strcmp(*argv, "src") && !strcmp(argv[1], "eq")) { 191 type = strtol(argv[2], &cp, 0); 192 if (cp == argv[2]) { 193 log_Printf(LogWARN, "ParseIcmp: type is expected.\n"); 194 return (0); 195 } 196 tgt->opt.srcop = OP_EQ; 197 tgt->opt.srcport = type; 198 } 199 break; 200 201 default: 202 log_Printf(LogWARN, "ParseIcmp: bad icmp syntax.\n"); 203 return (0); 204 } 205 return (1); 206} 207 208/* 209 * UDP Syntax: [src op port] [dst op port] 210 */ 211static int 212ParseUdpOrTcp(int argc, char const *const *argv, int proto, 213 struct filterent *tgt) 214{ 215 tgt->opt.srcop = tgt->opt.dstop = OP_NONE; 216 tgt->opt.estab = tgt->opt.syn = tgt->opt.finrst = 0; 217 218 if (argc >= 3 && !strcmp(*argv, "src")) { 219 tgt->opt.srcop = filter_Nam2Op(argv[1]); 220 if (tgt->opt.srcop == OP_NONE) { 221 log_Printf(LogWARN, "ParseUdpOrTcp: bad operation\n"); 222 return (0); 223 } 224 tgt->opt.srcport = ParsePort(argv[2], proto); 225 if (tgt->opt.srcport == 0) 226 return (0); 227 argc -= 3; 228 argv += 3; 229 } 230 231 if (argc >= 3 && !strcmp(argv[0], "dst")) { 232 tgt->opt.dstop = filter_Nam2Op(argv[1]); 233 if (tgt->opt.dstop == OP_NONE) { 234 log_Printf(LogWARN, "ParseUdpOrTcp: bad operation\n"); 235 return (0); 236 } 237 tgt->opt.dstport = ParsePort(argv[2], proto); 238 if (tgt->opt.dstport == 0) 239 return (0); 240 argc -= 3; 241 argv += 3; 242 } 243 244 if (proto == P_TCP) { 245 for (; argc > 0; argc--, argv++) 246 if (!strcmp(*argv, "estab")) 247 tgt->opt.estab = 1; 248 else if (!strcmp(*argv, "syn")) 249 tgt->opt.syn = 1; 250 else if (!strcmp(*argv, "finrst")) 251 tgt->opt.finrst = 1; 252 else 253 break; 254 } 255 256 if (argc > 0) { 257 log_Printf(LogWARN, "ParseUdpOrTcp: bad src/dst port syntax: %s\n", *argv); 258 return 0; 259 } 260 261 return 1; 262} 263 264static int 265Parse(struct ipcp *ipcp, int argc, char const *const *argv, 266 struct filterent *ofp) 267{ 268 int action, proto; 269 int val; 270 char *wp; 271 struct filterent filterdata; 272 273 val = strtol(*argv, &wp, 0); 274 if (*argv == wp || val > MAXFILTERS) { 275 log_Printf(LogWARN, "Parse: invalid filter number.\n"); 276 return (0); 277 } 278 if (val < 0) { 279 for (val = 0; val < MAXFILTERS; val++) { 280 ofp->action = A_NONE; 281 ofp++; 282 } 283 log_Printf(LogWARN, "Parse: filter cleared.\n"); 284 return (1); 285 } 286 ofp += val; 287 288 if (--argc == 0) { 289 log_Printf(LogWARN, "Parse: missing action.\n"); 290 return (0); 291 } 292 argv++; 293 294 proto = P_NONE; 295 memset(&filterdata, '\0', sizeof filterdata); 296 297 if (!strcmp(*argv, "permit")) { 298 action = A_PERMIT; 299 } else if (!strcmp(*argv, "deny")) { 300 action = A_DENY; 301 } else if (!strcmp(*argv, "clear")) { 302 ofp->action = A_NONE; 303 return (1); 304 } else { 305 log_Printf(LogWARN, "Parse: bad action: %s\n", *argv); 306 return (0); 307 } 308 filterdata.action = action; 309 310 argc--; 311 argv++; 312 313 if (argc && filterdata.action == A_DENY) { 314 if (!strcmp(*argv, "host")) { 315 filterdata.action |= A_UHOST; 316 argc--; 317 argv++; 318 } else if (!strcmp(*argv, "port")) { 319 filterdata.action |= A_UPORT; 320 argc--; 321 argv++; 322 } 323 } 324 325 proto = filter_Nam2Proto(argc, argv); 326 if (proto == P_NONE) { 327 if (!argc) 328 log_Printf(LogWARN, "Parse: address/mask is expected.\n"); 329 else if (ParseAddr(ipcp, *argv, &filterdata.saddr, &filterdata.smask, 330 &filterdata.swidth)) { 331 argc--; 332 argv++; 333 proto = filter_Nam2Proto(argc, argv); 334 if (!argc) 335 log_Printf(LogWARN, "Parse: address/mask is expected.\n"); 336 else if (proto == P_NONE) { 337 if (ParseAddr(ipcp, *argv, &filterdata.daddr, &filterdata.dmask, 338 &filterdata.dwidth)) { 339 argc--; 340 argv++; 341 } 342 proto = filter_Nam2Proto(argc, argv); 343 if (argc && proto != P_NONE) { 344 argc--; 345 argv++; 346 } 347 } else { 348 argc--; 349 argv++; 350 } 351 } else { 352 log_Printf(LogWARN, "Parse: Address/protocol expected.\n"); 353 return (0); 354 } 355 } else { 356 argc--; 357 argv++; 358 } 359 360 val = 1; 361 filterdata.proto = proto; 362 363 switch (proto) { 364 case P_TCP: 365 val = ParseUdpOrTcp(argc, argv, P_TCP, &filterdata); 366 break; 367 case P_UDP: 368 val = ParseUdpOrTcp(argc, argv, P_UDP, &filterdata); 369 break; 370 case P_ICMP: 371 val = ParseIcmp(argc, argv, &filterdata); 372 break; 373 } 374 375 log_Printf(LogDEBUG, "Parse: Src: %s\n", inet_ntoa(filterdata.saddr)); 376 log_Printf(LogDEBUG, "Parse: Src mask: %s\n", inet_ntoa(filterdata.smask)); 377 log_Printf(LogDEBUG, "Parse: Dst: %s\n", inet_ntoa(filterdata.daddr)); 378 log_Printf(LogDEBUG, "Parse: Dst mask: %s\n", inet_ntoa(filterdata.dmask)); 379 log_Printf(LogDEBUG, "Parse: Proto = %d\n", proto); 380 381 log_Printf(LogDEBUG, "Parse: src: %s (%d)\n", 382 filter_Op2Nam(filterdata.opt.srcop), filterdata.opt.srcport); 383 log_Printf(LogDEBUG, "Parse: dst: %s (%d)\n", 384 filter_Op2Nam(filterdata.opt.dstop), filterdata.opt.dstport); 385 log_Printf(LogDEBUG, "Parse: estab: %u\n", filterdata.opt.estab); 386 log_Printf(LogDEBUG, "Parse: syn: %u\n", filterdata.opt.syn); 387 log_Printf(LogDEBUG, "Parse: finrst: %u\n", filterdata.opt.finrst); 388 389 if (val) 390 *ofp = filterdata; 391 return (val); 392} 393 394int 395filter_Set(struct cmdargs const *arg) 396{ 397 struct filter *filter; 398 399 if (arg->argc < arg->argn+2) 400 return -1; 401 402 if (!strcmp(arg->argv[arg->argn], "in")) 403 filter = &arg->bundle->filter.in; 404 else if (!strcmp(arg->argv[arg->argn], "out")) 405 filter = &arg->bundle->filter.out; 406 else if (!strcmp(arg->argv[arg->argn], "dial")) 407 filter = &arg->bundle->filter.dial; 408 else if (!strcmp(arg->argv[arg->argn], "alive")) 409 filter = &arg->bundle->filter.alive; 410 else { 411 log_Printf(LogWARN, "filter_Set: %s: Invalid filter name.\n", 412 arg->argv[arg->argn]); 413 return -1; 414 } 415 416 Parse(&arg->bundle->ncp.ipcp, arg->argc - arg->argn - 1, 417 arg->argv + arg->argn + 1, filter->rule); 418 return 0; 419} 420 421const char * 422filter_Action2Nam(int act) 423{ 424 static const char *actname[] = { "none ", "permit ", "deny " }; 425 return actname[act & (A_PERMIT|A_DENY)]; 426} 427 428static void 429doShowFilter(struct filterent *fp, struct prompt *prompt) 430{ 431 int n; 432 433 for (n = 0; n < MAXFILTERS; n++, fp++) { 434 if (fp->action != A_NONE) { 435 prompt_Printf(prompt, " %2d %s", n, filter_Action2Nam(fp->action)); 436 if (fp->action & A_UHOST) 437 prompt_Printf(prompt, "host "); 438 else if (fp->action & A_UPORT) 439 prompt_Printf(prompt, "port "); 440 else 441 prompt_Printf(prompt, " "); 442 prompt_Printf(prompt, "%s/%d ", inet_ntoa(fp->saddr), fp->swidth); 443 prompt_Printf(prompt, "%s/%d ", inet_ntoa(fp->daddr), fp->dwidth); 444 if (fp->proto) { 445 prompt_Printf(prompt, "%s", filter_Proto2Nam(fp->proto)); 446 447 if (fp->opt.srcop) 448 prompt_Printf(prompt, " src %s %d", filter_Op2Nam(fp->opt.srcop), 449 fp->opt.srcport); 450 if (fp->opt.dstop) 451 prompt_Printf(prompt, " dst %s %d", filter_Op2Nam(fp->opt.dstop), 452 fp->opt.dstport); 453 if (fp->opt.estab) 454 prompt_Printf(prompt, " estab"); 455 if (fp->opt.syn) 456 prompt_Printf(prompt, " syn"); 457 if (fp->opt.finrst) 458 prompt_Printf(prompt, " finrst"); 459 } 460 prompt_Printf(prompt, "\n"); 461 } 462 } 463} 464 465int 466filter_Show(struct cmdargs const *arg) 467{ 468 if (arg->argc > arg->argn+1) 469 return -1; 470 471 if (arg->argc == arg->argn+1) { 472 struct filter *filter; 473 474 if (!strcmp(arg->argv[arg->argn], "in")) 475 filter = &arg->bundle->filter.in; 476 else if (!strcmp(arg->argv[arg->argn], "out")) 477 filter = &arg->bundle->filter.out; 478 else if (!strcmp(arg->argv[arg->argn], "dial")) 479 filter = &arg->bundle->filter.dial; 480 else if (!strcmp(arg->argv[arg->argn], "alive")) 481 filter = &arg->bundle->filter.alive; 482 else 483 return -1; 484 doShowFilter(filter->rule, arg->prompt); 485 } else { 486 struct filter *filter[4]; 487 int f; 488 489 filter[0] = &arg->bundle->filter.in; 490 filter[1] = &arg->bundle->filter.out; 491 filter[2] = &arg->bundle->filter.dial; 492 filter[3] = &arg->bundle->filter.alive; 493 for (f = 0; f < 4; f++) { 494 if (f) 495 prompt_Printf(arg->prompt, "\n"); 496 prompt_Printf(arg->prompt, "%s:\n", filter[f]->name); 497 doShowFilter(filter[f]->rule, arg->prompt); 498 } 499 } 500 501 return 0; 502} 503 504static const char *protoname[] = { "none", "tcp", "udp", "icmp" }; 505 506const char * 507filter_Proto2Nam(int proto) 508{ 509 if (proto >= sizeof protoname / sizeof protoname[0]) 510 return "unknown"; 511 return protoname[proto]; 512} 513 514static int 515filter_Nam2Proto(int argc, char const *const *argv) 516{ 517 int proto; 518 519 if (argc == 0) 520 proto = 0; 521 else 522 for (proto = sizeof protoname / sizeof protoname[0] - 1; proto; proto--) 523 if (!strcasecmp(*argv, protoname[proto])) 524 break; 525 526 return proto; 527} 528 529static const char *opname[] = {"none", "eq", "gt", "unknown", "lt"}; 530 531const char * 532filter_Op2Nam(int op) 533{ 534 if (op >= sizeof opname / sizeof opname[0]) 535 return "unknown"; 536 return opname[op]; 537 538} 539 540static int 541filter_Nam2Op(const char *cp) 542{ 543 int op; 544 545 for (op = sizeof opname / sizeof opname[0] - 1; op; op--) 546 if (!strcasecmp(cp, opname[op])) 547 break; 548 549 return op; 550} 551