1 /* 2 * m_pedit.c generic packet editor actions module 3 * 4 * This program is free software; you can distribute it and/or 5 * modify it under the terms of the GNU General Public License 6 * as published by the Free Software Foundation; either version 7 * 2 of the License, or (at your option) any later version. 8 * 9 * Authors: J Hadi Salim (hadi (at) cyberus.ca) 10 * 11 * TODO: 12 * 1) Big endian broken in some spots 13 * 2) A lot of this stuff was added on the fly; get a big double-double 14 * and clean it up at some point. 15 * 16 */ 17 18 #include <stdio.h> 19 #include <stdlib.h> 20 #include <unistd.h> 21 #include <syslog.h> 22 #include <fcntl.h> 23 #include <sys/socket.h> 24 #include <netinet/in.h> 25 #include <arpa/inet.h> 26 #include <string.h> 27 #include <dlfcn.h> 28 #include "utils.h" 29 #include "tc_util.h" 30 #include "m_pedit.h" 31 32 static struct m_pedit_util *pedit_list; 33 int pedit_debug = 1; 34 35 static void 36 explain(void) 37 { 38 fprintf(stderr, "Usage: ... pedit munge <MUNGE>\n"); 39 fprintf(stderr, 40 "Where: MUNGE := <RAW>|<LAYERED>\n" 41 "\t<RAW>:= <OFFSETC>[ATC]<CMD>\n " 42 "\t\tOFFSETC:= offset <offval> <u8|u16|u32>\n " 43 "\t\tATC:= at <atval> offmask <maskval> shift <shiftval>\n " 44 "\t\tNOTE: offval is byte offset, must be multiple of 4\n " 45 "\t\tNOTE: maskval is a 32 bit hex number\n " 46 "\t\tNOTE: shiftval is a is a shift value\n " 47 "\t\tCMD:= clear | invert | set <setval>| retain\n " 48 "\t<LAYERED>:= ip <ipdata> | ip6 <ip6data> \n " 49 " \t\t| udp <udpdata> | tcp <tcpdata> | icmp <icmpdata> \n" 50 "For Example usage look at the examples directory\n"); 51 52 } 53 54 static void 55 usage(void) 56 { 57 explain(); 58 exit(-1); 59 } 60 61 static int 62 pedit_parse_nopopt (int *argc_p, char ***argv_p,struct tc_pedit_sel *sel,struct tc_pedit_key *tkey) 63 { 64 int argc = *argc_p; 65 char **argv = *argv_p; 66 67 if (argc) { 68 fprintf(stderr, "Unknown action hence option \"%s\" is unparsable\n", *argv); 69 return -1; 70 } 71 72 return 0; 73 74 } 75 76 struct m_pedit_util 77 *get_pedit_kind(char *str) 78 { 79 static void *pBODY; 80 void *dlh; 81 char buf[256]; 82 struct m_pedit_util *p; 83 84 for (p = pedit_list; p; p = p->next) { 85 if (strcmp(p->id, str) == 0) 86 return p; 87 } 88 89 snprintf(buf, sizeof(buf), "p_%s.so", str); 90 dlh = dlopen(buf, RTLD_LAZY); 91 if (dlh == NULL) { 92 dlh = pBODY; 93 if (dlh == NULL) { 94 dlh = pBODY = dlopen(NULL, RTLD_LAZY); 95 if (dlh == NULL) 96 goto noexist; 97 } 98 } 99 100 snprintf(buf, sizeof(buf), "p_pedit_%s", str); 101 p = dlsym(dlh, buf); 102 if (p == NULL) 103 goto noexist; 104 105 reg: 106 p->next = pedit_list; 107 pedit_list = p; 108 return p; 109 110 noexist: 111 p = malloc(sizeof(*p)); 112 if (p) { 113 memset(p, 0, sizeof(*p)); 114 strncpy(p->id, str, sizeof(p->id)-1); 115 p->parse_peopt = pedit_parse_nopopt; 116 goto reg; 117 } 118 return p; 119 } 120 121 int 122 pack_key(struct tc_pedit_sel *sel,struct tc_pedit_key *tkey) 123 { 124 int hwm = sel->nkeys; 125 126 if (hwm >= MAX_OFFS) 127 return -1; 128 129 if (tkey->off % 4) { 130 fprintf(stderr, "offsets MUST be in 32 bit boundaries\n"); 131 return -1; 132 } 133 134 sel->keys[hwm].val = tkey->val; 135 sel->keys[hwm].mask = tkey->mask; 136 sel->keys[hwm].off = tkey->off; 137 sel->keys[hwm].at = tkey->at; 138 sel->keys[hwm].offmask = tkey->offmask; 139 sel->keys[hwm].shift = tkey->shift; 140 sel->nkeys++; 141 return 0; 142 } 143 144 145 int 146 pack_key32(__u32 retain,struct tc_pedit_sel *sel,struct tc_pedit_key *tkey) 147 { 148 if (tkey->off > (tkey->off & ~3)) { 149 fprintf(stderr, 150 "pack_key32: 32 bit offsets must begin in 32bit boundaries\n"); 151 return -1; 152 } 153 154 tkey->val = htonl(tkey->val & retain); 155 tkey->mask = htonl(tkey->mask | ~retain); 156 /* jamal remove this - it is not necessary given the if check above */ 157 tkey->off &= ~3; 158 return pack_key(sel,tkey); 159 } 160 161 int 162 pack_key16(__u32 retain,struct tc_pedit_sel *sel,struct tc_pedit_key *tkey) 163 { 164 int ind = 0, stride = 0; 165 __u32 m[4] = {0xFFFF0000,0xFF0000FF,0x0000FFFF}; 166 167 if (0 > tkey->off) { 168 ind = tkey->off + 1; 169 if (0 > ind) 170 ind = -1*ind; 171 } else { 172 ind = tkey->off; 173 } 174 175 if (tkey->val > 0xFFFF || tkey->mask > 0xFFFF) { 176 fprintf(stderr, "pack_key16 bad value\n"); 177 return -1; 178 } 179 180 ind = tkey->off & 3; 181 182 if (0 > ind || 2 < ind) { 183 fprintf(stderr, "pack_key16 bad index value %d\n",ind); 184 return -1; 185 } 186 187 stride = 8 * ind; 188 tkey->val = htons(tkey->val); 189 if (stride > 0) { 190 tkey->val <<= stride; 191 tkey->mask <<= stride; 192 retain <<= stride; 193 } 194 tkey->mask = retain|m[ind]; 195 196 tkey->off &= ~3; 197 198 if (pedit_debug) 199 printf("pack_key16: Final val %08x mask %08x \n",tkey->val,tkey->mask); 200 return pack_key(sel,tkey); 201 202 } 203 204 int 205 pack_key8(__u32 retain,struct tc_pedit_sel *sel,struct tc_pedit_key *tkey) 206 { 207 int ind = 0, stride = 0; 208 __u32 m[4] = {0xFFFFFF00,0xFFFF00FF,0xFF00FFFF,0x00FFFFFF}; 209 210 if (0 > tkey->off) { 211 ind = tkey->off + 1; 212 if (0 > ind) 213 ind = -1*ind; 214 } else { 215 ind = tkey->off; 216 } 217 218 if (tkey->val > 0xFF || tkey->mask > 0xFF) { 219 fprintf(stderr, "pack_key8 bad value (val %x mask %x\n", tkey->val, tkey->mask); 220 return -1; 221 } 222 223 ind = tkey->off & 3; 224 stride = 8 * ind; 225 tkey->val <<= stride; 226 tkey->mask <<= stride; 227 retain <<= stride; 228 tkey->mask = retain|m[ind]; 229 tkey->off &= ~3; 230 231 if (pedit_debug) 232 printf("pack_key8: Final word off %d val %08x mask %08x \n",tkey->off , tkey->val,tkey->mask); 233 return pack_key(sel,tkey); 234 } 235 236 int 237 parse_val(int *argc_p, char ***argv_p, __u32 * val, int type) 238 { 239 int argc = *argc_p; 240 char **argv = *argv_p; 241 242 if (argc <= 0) 243 return -1; 244 245 if (TINT == type) 246 return get_integer((int *) val, *argv, 0); 247 248 if (TU32 == type) 249 return get_u32(val, *argv, 0); 250 251 if (TIPV4 == type) { 252 inet_prefix addr; 253 if (get_prefix_1(&addr, *argv, AF_INET)) { 254 return -1; 255 } 256 *val=addr.data[0]; 257 return 0; 258 } 259 if (TIPV6 == type) { 260 /* not implemented yet */ 261 return -1; 262 } 263 264 return -1; 265 } 266 267 int 268 parse_cmd(int *argc_p, char ***argv_p, __u32 len, int type,__u32 retain,struct tc_pedit_sel *sel,struct tc_pedit_key *tkey) 269 { 270 __u32 mask = 0, val = 0; 271 __u32 o = 0xFF; 272 int res = -1; 273 int argc = *argc_p; 274 char **argv = *argv_p; 275 276 if (argc <= 0) 277 return -1; 278 279 if (pedit_debug) 280 printf("parse_cmd argc %d %s offset %d length %d\n",argc,*argv,tkey->off,len); 281 282 if (len == 2) 283 o = 0xFFFF; 284 if (len == 4) 285 o = 0xFFFFFFFF; 286 287 if (matches(*argv, "invert") == 0) { 288 retain = val = mask = o; 289 } else if (matches(*argv, "set") == 0) { 290 NEXT_ARG(); 291 if (parse_val(&argc, &argv, &val, type)) 292 return -1; 293 } else if (matches(*argv, "preserve") == 0) { 294 retain = mask = o; 295 } else { 296 if (matches(*argv, "clear") != 0) 297 return -1; 298 } 299 300 argc--; argv++; 301 302 if (argc && matches(*argv, "retain") == 0) { 303 NEXT_ARG(); 304 if (parse_val(&argc, &argv, &retain, TU32)) 305 return -1; 306 argc--; argv++; 307 } 308 309 tkey->val = val; 310 311 if (len == 1) { 312 tkey->mask = 0xFF; 313 res = pack_key8(retain,sel,tkey); 314 goto done; 315 } 316 if (len == 2) { 317 tkey->mask = mask; 318 res = pack_key16(retain,sel,tkey); 319 goto done; 320 } 321 if (len == 4) { 322 tkey->mask = mask; 323 res = pack_key32(retain,sel,tkey); 324 goto done; 325 } 326 327 return -1; 328 done: 329 if (pedit_debug) 330 printf("parse_cmd done argc %d %s offset %d length %d\n",argc,*argv,tkey->off,len); 331 *argc_p = argc; 332 *argv_p = argv; 333 return res; 334 335 } 336 337 int 338 parse_offset(int *argc_p, char ***argv_p,struct tc_pedit_sel *sel,struct tc_pedit_key *tkey) 339 { 340 int off; 341 __u32 len, retain; 342 int argc = *argc_p; 343 char **argv = *argv_p; 344 int res = -1; 345 346 if (argc <= 0) 347 return -1; 348 349 if (get_integer(&off, *argv, 0)) 350 return -1; 351 tkey->off = off; 352 353 argc--; 354 argv++; 355 356 if (argc <= 0) 357 return -1; 358 359 360 if (matches(*argv, "u32") == 0) { 361 len = 4; 362 retain = 0xFFFFFFFF; 363 goto done; 364 } 365 if (matches(*argv, "u16") == 0) { 366 len = 2; 367 retain = 0x0; 368 goto done; 369 } 370 if (matches(*argv, "u8") == 0) { 371 len = 1; 372 retain = 0x0; 373 goto done; 374 } 375 376 return -1; 377 378 done: 379 380 NEXT_ARG(); 381 382 /* [at <someval> offmask <maskval> shift <shiftval>] */ 383 if (matches(*argv, "at") == 0) { 384 385 __u32 atv=0,offmask=0x0,shift=0; 386 387 NEXT_ARG(); 388 if (get_u32(&atv, *argv, 0)) 389 return -1; 390 tkey->at = atv; 391 392 NEXT_ARG(); 393 394 if (get_u32(&offmask, *argv, 16)) 395 return -1; 396 tkey->offmask = offmask; 397 398 NEXT_ARG(); 399 400 if (get_u32(&shift, *argv, 0)) 401 return -1; 402 tkey->shift = shift; 403 404 NEXT_ARG(); 405 } 406 407 res = parse_cmd(&argc, &argv, len, TU32,retain,sel,tkey); 408 409 *argc_p = argc; 410 *argv_p = argv; 411 return res; 412 } 413 414 int 415 parse_munge(int *argc_p, char ***argv_p,struct tc_pedit_sel *sel) 416 { 417 struct tc_pedit_key tkey; 418 int argc = *argc_p; 419 char **argv = *argv_p; 420 int res = -1; 421 422 if (argc <= 0) 423 return -1; 424 425 memset(&tkey, 0, sizeof(tkey)); 426 427 if (matches(*argv, "offset") == 0) { 428 NEXT_ARG(); 429 res = parse_offset(&argc, &argv,sel,&tkey); 430 goto done; 431 } else { 432 char k[16]; 433 struct m_pedit_util *p = NULL; 434 435 strncpy(k, *argv, sizeof (k) - 1); 436 437 if (argc > 0 ) { 438 p = get_pedit_kind(k); 439 if (NULL == p) 440 goto bad_val; 441 res = p->parse_peopt(&argc, &argv, sel,&tkey); 442 if (res < 0) { 443 fprintf(stderr,"bad pedit parsing\n"); 444 goto bad_val; 445 } 446 goto done; 447 } 448 } 449 450 bad_val: 451 return -1; 452 453 done: 454 455 *argc_p = argc; 456 *argv_p = argv; 457 return res; 458 } 459 460 int 461 parse_pedit(struct action_util *a, int *argc_p, char ***argv_p, int tca_id, struct nlmsghdr *n) 462 { 463 struct { 464 struct tc_pedit_sel sel; 465 struct tc_pedit_key keys[MAX_OFFS]; 466 } sel; 467 468 int argc = *argc_p; 469 char **argv = *argv_p; 470 int ok = 0, iok = 0; 471 struct rtattr *tail; 472 473 memset(&sel, 0, sizeof(sel)); 474 475 while (argc > 0) { 476 if (pedit_debug > 1) 477 fprintf(stderr, "while pedit (%d:%s)\n",argc, *argv); 478 if (matches(*argv, "pedit") == 0) { 479 NEXT_ARG(); 480 ok++; 481 continue; 482 } else if (matches(*argv, "help") == 0) { 483 usage(); 484 } else if (matches(*argv, "munge") == 0) { 485 if (!ok) { 486 fprintf(stderr, "Illegal pedit construct (%s) \n", *argv); 487 explain(); 488 return -1; 489 } 490 NEXT_ARG(); 491 if (parse_munge(&argc, &argv,&sel.sel)) { 492 fprintf(stderr, "Illegal pedit construct (%s) \n", *argv); 493 explain(); 494 return -1; 495 } 496 ok++; 497 } else { 498 break; 499 } 500 501 } 502 503 if (!ok) { 504 explain(); 505 return -1; 506 } 507 508 if (argc) { 509 if (matches(*argv, "reclassify") == 0) { 510 sel.sel.action = TC_ACT_RECLASSIFY; 511 NEXT_ARG(); 512 } else if (matches(*argv, "pipe") == 0) { 513 sel.sel.action = TC_ACT_PIPE; 514 NEXT_ARG(); 515 } else if (matches(*argv, "drop") == 0 || 516 matches(*argv, "shot") == 0) { 517 sel.sel.action = TC_ACT_SHOT; 518 NEXT_ARG(); 519 } else if (matches(*argv, "continue") == 0) { 520 sel.sel.action = TC_ACT_UNSPEC; 521 NEXT_ARG(); 522 } else if (matches(*argv, "pass") == 0) { 523 sel.sel.action = TC_ACT_OK; 524 NEXT_ARG(); 525 } 526 } 527 528 if (argc) { 529 if (matches(*argv, "index") == 0) { 530 NEXT_ARG(); 531 if (get_u32(&sel.sel.index, *argv, 10)) { 532 fprintf(stderr, "Pedit: Illegal \"index\"\n"); 533 return -1; 534 } 535 argc--; 536 argv++; 537 iok++; 538 } 539 } 540 541 tail = NLMSG_TAIL(n); 542 addattr_l(n, MAX_MSG, tca_id, NULL, 0); 543 addattr_l(n, MAX_MSG, TCA_PEDIT_PARMS,&sel, sizeof(sel.sel)+sel.sel.nkeys*sizeof(struct tc_pedit_key)); 544 tail->rta_len = (void *) NLMSG_TAIL(n) - (void *) tail; 545 546 *argc_p = argc; 547 *argv_p = argv; 548 return 0; 549 } 550 551 int 552 print_pedit(struct action_util *au,FILE * f, struct rtattr *arg) 553 { 554 struct tc_pedit_sel *sel; 555 struct rtattr *tb[TCA_PEDIT_MAX + 1]; 556 SPRINT_BUF(b1); 557 558 if (arg == NULL) 559 return -1; 560 561 parse_rtattr_nested(tb, TCA_PEDIT_MAX, arg); 562 563 if (tb[TCA_PEDIT_PARMS] == NULL) { 564 fprintf(f, "[NULL pedit parameters]"); 565 return -1; 566 } 567 sel = RTA_DATA(tb[TCA_PEDIT_PARMS]); 568 569 fprintf(f, " pedit action %s keys %d\n ", action_n2a(sel->action, b1, sizeof (b1)),sel->nkeys); 570 fprintf(f, "\t index %d ref %d bind %d", sel->index,sel->refcnt, sel->bindcnt); 571 572 if (show_stats) { 573 if (tb[TCA_PEDIT_TM]) { 574 struct tcf_t *tm = RTA_DATA(tb[TCA_PEDIT_TM]); 575 print_tm(f,tm); 576 } 577 } 578 if (sel->nkeys) { 579 int i; 580 struct tc_pedit_key *key = sel->keys; 581 582 for (i=0; i<sel->nkeys; i++, key++) { 583 fprintf(f, "\n\t key #%d",i); 584 fprintf(f, " at %d: val %08x mask %08x", 585 (unsigned int)key->off, 586 (unsigned int)ntohl(key->val), 587 (unsigned int)ntohl(key->mask)); 588 } 589 } else { 590 fprintf(f, "\npedit %x keys %d is not LEGIT", sel->index,sel->nkeys); 591 } 592 593 594 fprintf(f, "\n "); 595 return 0; 596 } 597 598 int 599 pedit_print_xstats(struct action_util *au, FILE *f, struct rtattr *xstats) 600 { 601 return 0; 602 } 603 604 struct action_util pedit_action_util = { 605 .id = "pedit", 606 .parse_aopt = parse_pedit, 607 .print_aopt = print_pedit, 608 }; 609
