release/src/router/iproute2/tc/m_ipt.c

   1 /*
   2  * m_ipt.c      iptables based targets
   3  *              utilities mostly ripped from iptables <duh, its the linux way>
   4  *
   5  *              This program is free software; you can distribute it and/or
   6  *              modify it under the terms of the GNU General Public License
   7  *              as published by the Free Software Foundation; either version
   8  *              2 of the License, or (at your option) any later version.
   9  *
  10  * Authors:  J Hadi Salim (hadi@cyberus.ca)
  11  *
  12  * TODO: bad bad hardcoding IPT_LIB_DIR and PROC_SYS_MODPROBE
  13  *
  14 */
  15
  16 #include <syslog.h>
  17 #include <sys/socket.h>
  18 #include <netinet/in.h>
  19 #include <arpa/inet.h>
  20 #include <iptables.h>
  21 #include <linux/netfilter_ipv4/ip_tables.h>
  22 #include "utils.h"
  23 #include "tc_util.h"
  24 #include <linux/tc_act/tc_ipt.h>
  25 #include <stdio.h>
  26 #include <dlfcn.h>
  27 #include <getopt.h>
  28 #include <errno.h>
  29 #include <string.h>
  30 #include <netdb.h>
  31 #include <stdlib.h>
  32 #include <ctype.h>
  33 #include <stdarg.h>
  34 #include <limits.h>
  35 #include <unistd.h>
  36 #include <fcntl.h>
  37 #include <sys/wait.h>
  38
  39 const char *pname = "tc-ipt";
  40 const char *tname = "mangle";
  41 const char *pversion = "0.1";
  42
  43 #ifndef TRUE
  44 #define TRUE 1
  45 #endif
  46 #ifndef FALSE
  47 #define FALSE 0
  48 #endif
  49
  50 #ifndef IPT_LIB_DIR
  51 #define IPT_LIB_DIR "/usr/local/lib/iptables"
  52 #endif
  53
  54 #ifndef PROC_SYS_MODPROBE
  55 #define PROC_SYS_MODPROBE "/proc/sys/kernel/modprobe"
  56 #endif
  57
  58 static const char *ipthooks[] = {
  59         "NF_IP_PRE_ROUTING",
  60         "NF_IP_LOCAL_IN",
  61         "NF_IP_FORWARD",
  62         "NF_IP_LOCAL_OUT",
  63         "NF_IP_POST_ROUTING",
  64 };
  65
  66 static struct option original_opts[] = {
  67         {"jump", 1, 0, 'j'},
  68         {0, 0, 0, 0}
  69 };
  70
  71 static struct iptables_target *t_list = NULL;
  72 static struct option *opts = original_opts;
  73 static unsigned int global_option_offset = 0;
  74 #define OPTION_OFFSET 256
  75
  76
  77 void
  78 register_target(struct iptables_target *me)
  79 {
  80 /*      fprintf(stderr, "\nDummy register_target %s \n", me->name);
  81 */
  82         me->next = t_list;
  83         t_list = me;
  84
  85 }
  86
  87 void
  88 exit_tryhelp(int status)
  89 {
  90         fprintf(stderr, "Try `%s -h' or '%s --help' for more information.\n",
  91                 pname, pname);
  92         exit(status);
  93 }
  94
  95 void
  96 exit_error(enum exittype status, char *msg, ...)
  97 {
  98         va_list args;
  99
 100         va_start(args, msg);
 101         fprintf(stderr, "%s v%s: ", pname, pversion);
 102         vfprintf(stderr, msg, args);
 103         va_end(args);
 104         fprintf(stderr, "\n");
 105         if (status == PARAMETER_PROBLEM)
 106                 exit_tryhelp(status);
 107         if (status == VERSION_PROBLEM)
 108                 fprintf(stderr,
 109                         "Perhaps iptables or your kernel needs to be upgraded.\n");
 110         exit(status);
 111 }
 112
 113 /* stolen from iptables 1.2.11
 114 They should really have them as a library so i can link to them
 115 Email them next time i remember
 116 */
 117
 118 char *
 119 addr_to_dotted(const struct in_addr *addrp)
 120 {
 121         static char buf[20];
 122         const unsigned char *bytep;
 123
 124         bytep = (const unsigned char *) &(addrp->s_addr);
 125         sprintf(buf, "%d.%d.%d.%d", bytep[0], bytep[1], bytep[2], bytep[3]);
 126         return buf;
 127 }
 128
 129 int string_to_number_ll(const char *s, unsigned long long min,
 130                         unsigned long long max,
 131                  unsigned long long *ret)
 132 {
 133         unsigned long long number;
 134         char *end;
 135
 136         /* Handle hex, octal, etc. */
 137         errno = 0;
 138         number = strtoull(s, &end, 0);
 139         if (*end == '\0' && end != s) {
 140                 /* we parsed a number, let's see if we want this */
 141                 if (errno != ERANGE && min <= number && (!max || number <= max)) {
 142                         *ret = number;
 143                         return 0;
 144                 }
 145         }
 146         return -1;
 147 }
 148
 149 int string_to_number_l(const char *s, unsigned long min, unsigned long max,
 150                        unsigned long *ret)
 151 {
 152         int result;
 153         unsigned long long number;
 154
 155         result = string_to_number_ll(s, min, max, &number);
 156         *ret = (unsigned long)number;
 157
 158         return result;
 159 }
 160
 161 int string_to_number(const char *s, unsigned int min, unsigned int max,
 162                 unsigned int *ret)
 163 {
 164         int result;
 165         unsigned long number;
 166
 167         result = string_to_number_l(s, min, max, &number);
 168         *ret = (unsigned int)number;
 169
 170         return result;
 171 }
 172
 173 static void free_opts(struct option *local_opts)
 174 {
 175         if (local_opts != original_opts) {
 176                 free(local_opts);
 177                 opts = original_opts;
 178                 global_option_offset = 0;
 179         }
 180 }
 181
 182 static struct option *
 183 merge_options(struct option *oldopts, const struct option *newopts,
 184               unsigned int *option_offset)
 185 {
 186         struct option *merge;
 187         unsigned int num_old, num_new, i;
 188
 189         for (num_old = 0; oldopts[num_old].name; num_old++) ;
 190         for (num_new = 0; newopts[num_new].name; num_new++) ;
 191
 192         *option_offset = global_option_offset + OPTION_OFFSET;
 193
 194         merge = malloc(sizeof (struct option) * (num_new + num_old + 1));
 195         memcpy(merge, oldopts, num_old * sizeof (struct option));
 196         for (i = 0; i < num_new; i++) {
 197                 merge[num_old + i] = newopts[i];
 198                 merge[num_old + i].val += *option_offset;
 199         }
 200         memset(merge + num_old + num_new, 0, sizeof (struct option));
 201
 202         return merge;
 203 }
 204
 205 static void *
 206 fw_calloc(size_t count, size_t size)
 207 {
 208         void *p;
 209
 210         if ((p = (void *) calloc(count, size)) == NULL) {
 211                 perror("iptables: calloc failed");
 212                 exit(1);
 213         }
 214         return p;
 215 }
 216
 217 static struct iptables_target *
 218 find_t(char *name)
 219 {
 220         struct iptables_target *m;
 221         for (m = t_list; m; m = m->next) {
 222                 if (strcmp(m->name, name) == 0)
 223                         return m;
 224         }
 225
 226         return NULL;
 227 }
 228
 229 static struct iptables_target *
 230 get_target_name(char *name)
 231 {
 232         void *handle;
 233         char *error;
 234         char *new_name, *lname;
 235         struct iptables_target *m;
 236
 237         char path[sizeof (IPT_LIB_DIR) + sizeof ("/libipt_.so") + strlen(name)];
 238
 239         new_name = malloc(strlen(name) + 1);
 240         lname = malloc(strlen(name) + 1);
 241         if (new_name)
 242                 memset(new_name, '\0', strlen(name) + 1);
 243         else
 244                 exit_error(PARAMETER_PROBLEM, "get_target_name");
 245
 246         if (lname)
 247                 memset(lname, '\0', strlen(name) + 1);
 248         else
 249                 exit_error(PARAMETER_PROBLEM, "get_target_name");
 250
 251         strcpy(new_name, name);
 252         strcpy(lname, name);
 253
 254         if (isupper(lname[0])) {
 255                 int i;
 256                 for (i = 0; i < strlen(name); i++) {
 257                         lname[i] = tolower(lname[i]);
 258                 }
 259         }
 260
 261         if (islower(new_name[0])) {
 262                 int i;
 263                 for (i = 0; i < strlen(new_name); i++) {
 264                         new_name[i] = toupper(new_name[i]);
 265                 }
 266         }
 267
 268         sprintf(path, IPT_LIB_DIR "/libipt_%s.so", new_name);
 269         handle = dlopen(path, RTLD_LAZY);
 270         if (!handle) {
 271                 sprintf(path, IPT_LIB_DIR "/libipt_%s.so", lname);
 272                 handle = dlopen(path, RTLD_LAZY);
 273                 if (!handle) {
 274                         fputs(dlerror(), stderr);
 275                         printf("\n");
 276                         free(lname);
 277                         free(new_name);
 278                         return NULL;
 279                 }
 280         }
 281
 282         m = dlsym(handle, new_name);
 283         if ((error = dlerror()) != NULL) {
 284                 m = (struct iptables_target *) dlsym(handle, lname);
 285                 if ((error = dlerror()) != NULL) {
 286                         m = find_t(new_name);
 287                         if (NULL == m) {
 288                                 m = find_t(lname);
 289                                 if (NULL == m) {
 290                                         fputs(error, stderr);
 291                                         fprintf(stderr, "\n");
 292                                         dlclose(handle);
 293                                         free(lname);
 294                                         free(new_name);
 295                                         return NULL;
 296                                 }
 297                         }
 298                 }
 299         }
 300
 301         free(lname);
 302         free(new_name);
 303         return m;
 304 }
 305
 306
 307 struct in_addr *dotted_to_addr(const char *dotted)
 308 {
 309         static struct in_addr addr;
 310         unsigned char *addrp;
 311         char *p, *q;
 312         unsigned int onebyte;
 313         int i;
 314         char buf[20];
 315
 316         /* copy dotted string, because we need to modify it */
 317         strncpy(buf, dotted, sizeof (buf) - 1);
 318         addrp = (unsigned char *) &(addr.s_addr);
 319
 320         p = buf;
 321         for (i = 0; i < 3; i++) {
 322                 if ((q = strchr(p, '.')) == NULL)
 323                         return (struct in_addr *) NULL;
 324
 325                 *q = '\0';
 326                 if (string_to_number(p, 0, 255, &onebyte) == -1)
 327                         return (struct in_addr *) NULL;
 328
 329                 addrp[i] = (unsigned char) onebyte;
 330                 p = q + 1;
 331         }
 332
 333         /* we've checked 3 bytes, now we check the last one */
 334         if (string_to_number(p, 0, 255, &onebyte) == -1)
 335                 return (struct in_addr *) NULL;
 336
 337         addrp[3] = (unsigned char) onebyte;
 338
 339         return &addr;
 340 }
 341
 342 static void set_revision(char *name, u_int8_t revision)
 343 {
 344         /* Old kernel sources don't have ".revision" field,
 345         *  but we stole a byte from name. */
 346         name[IPT_FUNCTION_MAXNAMELEN - 2] = '\0';
 347         name[IPT_FUNCTION_MAXNAMELEN - 1] = revision;
 348 }
 349
 350 /*
 351  * we may need to check for version mismatch
 352 */
 353 int
 354 build_st(struct iptables_target *target, struct ipt_entry_target *t)
 355 {
 356         unsigned int nfcache = 0;
 357
 358         if (target) {
 359                 size_t size;
 360
 361                 size =
 362                     IPT_ALIGN(sizeof (struct ipt_entry_target)) + target->size;
 363
 364                 if (NULL == t) {
 365                         target->t = fw_calloc(1, size);
 366                         target->t->u.target_size = size;
 367
 368                         if (target->init != NULL)
 369                                 target->init(target->t, &nfcache);
 370                         set_revision(target->t->u.user.name, target->revision);
 371                 } else {
 372                         target->t = t;
 373                 }
 374                 strcpy(target->t->u.user.name, target->name);
 375                 return 0;
 376         }
 377
 378         return -1;
 379 }
 380
 381 static int parse_ipt(struct action_util *a,int *argc_p,
 382                      char ***argv_p, int tca_id, struct nlmsghdr *n)
 383 {
 384         struct iptables_target *m = NULL;
 385         struct ipt_entry fw;
 386         struct rtattr *tail;
 387         int c;
 388         int rargc = *argc_p;
 389         char **argv = *argv_p;
 390         int argc = 0, iargc = 0;
 391         char k[16];
 392         int res = -1;
 393         int size = 0;
 394         int iok = 0, ok = 0;
 395         __u32 hook = 0, index = 0;
 396         res = 0;
 397
 398         {
 399                 int i;
 400                 for (i = 0; i < rargc; i++) {
 401                         if (NULL == argv[i] || 0 == strcmp(argv[i], "action")) {
 402                                 break;
 403                         }
 404                 }
 405                 iargc = argc = i;
 406         }
 407
 408         if (argc <= 2) {
 409                 fprintf(stderr,"bad arguements to ipt %d vs %d \n", argc, rargc);
 410                 return -1;
 411         }
 412
 413         while (1) {
 414                 c = getopt_long(argc, argv, "j:", opts, NULL);
 415                 if (c == -1)
 416                         break;
 417                 switch (c) {
 418                 case 'j':
 419                         m = get_target_name(optarg);
 420                         if (NULL != m) {
 421
 422                                 if (0 > build_st(m, NULL)) {
 423                                         printf(" %s error \n", m->name);
 424                                         return -1;
 425                                 }
 426                                 opts =
 427                                     merge_options(opts, m->extra_opts,
 428                                                   &m->option_offset);
 429                         } else {
 430                                 fprintf(stderr," failed to find target %s\n\n", optarg);
 431                                 return -1;
 432                         }
 433                         ok++;
 434                         break;
 435
 436                 default:
 437                         memset(&fw, 0, sizeof (fw));
 438                         if (m) {
 439                                 m->parse(c - m->option_offset, argv, 0,
 440                                          &m->tflags, NULL, &m->t);
 441                         } else {
 442                                 fprintf(stderr," failed to find target %s\n\n", optarg);
 443                                 return -1;
 444
 445                         }
 446                         ok++;
 447                         break;
 448
 449                 }
 450         }
 451
 452         if (iargc > optind) {
 453                 if (matches(argv[optind], "index") == 0) {
 454                         if (get_u32(&index, argv[optind + 1], 10)) {
 455                                 fprintf(stderr, "Illegal \"index\"\n");
 456                                 free_opts(opts);
 457                                 return -1;
 458                         }
 459                         iok++;
 460
 461                         optind += 2;
 462                 }
 463         }
 464
 465         if (!ok && !iok) {
 466                 fprintf(stderr," ipt Parser BAD!! (%s)\n", *argv);
 467                 return -1;
 468         }
 469
 470         /* check that we passed the correct parameters to the target */
 471         if (m)
 472                 m->final_check(m->tflags);
 473
 474         {
 475                 struct tcmsg *t = NLMSG_DATA(n);
 476                 if (t->tcm_parent != TC_H_ROOT
 477                     && t->tcm_parent == TC_H_MAJ(TC_H_INGRESS)) {
 478                         hook = NF_IP_PRE_ROUTING;
 479                 } else {
 480                         hook = NF_IP_POST_ROUTING;
 481                 }
 482         }
 483
 484         tail = NLMSG_TAIL(n);
 485         addattr_l(n, MAX_MSG, tca_id, NULL, 0);
 486         fprintf(stdout, "tablename: %s hook: %s\n ", tname, ipthooks[hook]);
 487         fprintf(stdout, "\ttarget: ");
 488
 489         if (m)
 490                 m->print(NULL, m->t, 0);
 491         fprintf(stdout, " index %d\n", index);
 492
 493         if (strlen(tname) > 16) {
 494                 size = 16;
 495                 k[15] = 0;
 496         } else {
 497                 size = 1 + strlen(tname);
 498         }
 499         strncpy(k, tname, size);
 500
 501         addattr_l(n, MAX_MSG, TCA_IPT_TABLE, k, size);
 502         addattr_l(n, MAX_MSG, TCA_IPT_HOOK, &hook, 4);
 503         addattr_l(n, MAX_MSG, TCA_IPT_INDEX, &index, 4);
 504         if (m)
 505                 addattr_l(n, MAX_MSG, TCA_IPT_TARG, m->t, m->t->u.target_size);
 506         tail->rta_len = (void *) NLMSG_TAIL(n) - (void *) tail;
 507
 508         argc -= optind;
 509         argv += optind;
 510         *argc_p = rargc - iargc;
 511         *argv_p = argv;
 512
 513         optind = 0;
 514         free_opts(opts);
 515         /* Clear flags if target will be used again */
 516         m->tflags=0;
 517         m->used=0;
 518         /* Free allocated memory */
 519         if (m->t)
 520                 free(m->t);
 521
 522
 523         return 0;
 524
 525 }
 526
 527 static int
 528 print_ipt(struct action_util *au,FILE * f, struct rtattr *arg)
 529 {
 530         struct rtattr *tb[TCA_IPT_MAX + 1];
 531         struct ipt_entry_target *t = NULL;
 532
 533         if (arg == NULL)
 534                 return -1;
 535
 536         parse_rtattr_nested(tb, TCA_IPT_MAX, arg);
 537
 538         if (tb[TCA_IPT_TABLE] == NULL) {
 539                 fprintf(f, "[NULL ipt table name ] assuming mangle ");
 540         } else {
 541                 fprintf(f, "tablename: %s ",
 542                         (char *) RTA_DATA(tb[TCA_IPT_TABLE]));
 543         }
 544
 545         if (tb[TCA_IPT_HOOK] == NULL) {
 546                 fprintf(f, "[NULL ipt hook name ]\n ");
 547                 return -1;
 548         } else {
 549                 __u32 hook;
 550                 hook = *(__u32 *) RTA_DATA(tb[TCA_IPT_HOOK]);
 551                 fprintf(f, " hook: %s \n", ipthooks[hook]);
 552         }
 553
 554         if (tb[TCA_IPT_TARG] == NULL) {
 555                 fprintf(f, "\t[NULL ipt target parameters ] \n");
 556                 return -1;
 557         } else {
 558                 struct iptables_target *m = NULL;
 559                 t = RTA_DATA(tb[TCA_IPT_TARG]);
 560                 m = get_target_name(t->u.user.name);
 561                 if (NULL != m) {
 562                         if (0 > build_st(m, t)) {
 563                                 fprintf(stderr, " %s error \n", m->name);
 564                                 return -1;
 565                         }
 566
 567                         opts =
 568                             merge_options(opts, m->extra_opts,
 569                                           &m->option_offset);
 570                 } else {
 571                         fprintf(stderr, " failed to find target %s\n\n",
 572                                 t->u.user.name);
 573                         return -1;
 574                 }
 575                 fprintf(f, "\ttarget ");
 576                 m->print(NULL, m->t, 0);
 577                 if (tb[TCA_IPT_INDEX] == NULL) {
 578                         fprintf(f, " [NULL ipt target index ]\n");
 579                 } else {
 580                         __u32 index;
 581                         index = *(__u32 *) RTA_DATA(tb[TCA_IPT_INDEX]);
 582                         fprintf(f, " \n\tindex %d", index);
 583                 }
 584
 585                 if (tb[TCA_IPT_CNT]) {
 586                         struct tc_cnt *c  = RTA_DATA(tb[TCA_IPT_CNT]);;
 587                         fprintf(f, " ref %d bind %d", c->refcnt, c->bindcnt);
 588                 }
 589                 if (show_stats) {
 590                         if (tb[TCA_IPT_TM]) {
 591                                 struct tcf_t *tm = RTA_DATA(tb[TCA_IPT_TM]);
 592                                 print_tm(f,tm);
 593                         }
 594                 }
 595                 fprintf(f, " \n");
 596
 597         }
 598         free_opts(opts);
 599
 600         return 0;
 601 }
 602
 603 struct action_util ipt_action_util = {
 604         .id = "ipt",
 605         .parse_aopt = parse_ipt,
 606         .print_aopt = print_ipt,
 607 };
 608