tc/m_xt.c

   1 /*
   2  * m_xt.c       xtables 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
  13 /*XXX: in the future (xtables 1.4.3?) get rid of everything tagged
  14  * as TC_CONFIG_XT_H */
  15
  16 #include <syslog.h>
  17 #include <sys/socket.h>
  18 #include <netinet/in.h>
  19 #include <arpa/inet.h>
  20 #include <net/if.h>
  21 #include <limits.h>
  22 #include <linux/netfilter.h>
  23 #include <linux/netfilter_ipv4/ip_tables.h>
  24 #include <xtables.h>
  25 #include "utils.h"
  26 #include "tc_util.h"
  27 #include <linux/tc_act/tc_ipt.h>
  28 #include <stdio.h>
  29 #include <dlfcn.h>
  30 #include <getopt.h>
  31 #include <errno.h>
  32 #include <string.h>
  33 #include <netdb.h>
  34 #include <stdlib.h>
  35 #include <ctype.h>
  36 #include <stdarg.h>
  37 #include <limits.h>
  38 #include <unistd.h>
  39 #include <fcntl.h>
  40 #include <sys/wait.h>
  41 #ifdef TC_CONFIG_XT_H
  42 #include "xt-internal.h"
  43 #endif
  44
  45 static const char *pname = "tc-ipt";
  46 static const char *tname = "mangle";
  47 static const char *pversion = "0.2";
  48
  49 static const char *ipthooks[] = {
  50         "NF_IP_PRE_ROUTING",
  51         "NF_IP_LOCAL_IN",
  52         "NF_IP_FORWARD",
  53         "NF_IP_LOCAL_OUT",
  54         "NF_IP_POST_ROUTING",
  55 };
  56
  57 static struct option original_opts[] = {
  58         {"jump", 1, 0, 'j'},
  59         {0, 0, 0, 0}
  60 };
  61
  62 static struct option *opts = original_opts;
  63 static unsigned int global_option_offset = 0;
  64 char *lib_dir;
  65 const char *program_version = XTABLES_VERSION;
  66 const char *program_name = "tc-ipt";
  67 struct afinfo afinfo = {
  68         .family         = AF_INET,
  69         .libprefix      = "libxt_",
  70         .ipproto        = IPPROTO_IP,
  71         .kmod           = "ip_tables",
  72         .so_rev_target  = IPT_SO_GET_REVISION_TARGET,
  73 };
  74
  75
  76 #define OPTION_OFFSET 256
  77
  78 /*XXX: TC_CONFIG_XT_H */
  79 static void free_opts(struct option *local_opts)
  80 {
  81         if (local_opts != original_opts) {
  82                 free(local_opts);
  83                 opts = original_opts;
  84                 global_option_offset = 0;
  85         }
  86 }
  87
  88 /*XXX: TC_CONFIG_XT_H */
  89 static struct option *
  90 merge_options(struct option *oldopts, const struct option *newopts,
  91               unsigned int *option_offset)
  92 {
  93         struct option *merge;
  94         unsigned int num_old, num_new, i;
  95
  96         for (num_old = 0; oldopts[num_old].name; num_old++) ;
  97         for (num_new = 0; newopts[num_new].name; num_new++) ;
  98
  99         *option_offset = global_option_offset + OPTION_OFFSET;
 100
 101         merge = malloc(sizeof (struct option) * (num_new + num_old + 1));
 102         memcpy(merge, oldopts, num_old * sizeof (struct option));
 103         for (i = 0; i < num_new; i++) {
 104                 merge[num_old + i] = newopts[i];
 105                 merge[num_old + i].val += *option_offset;
 106         }
 107         memset(merge + num_old + num_new, 0, sizeof (struct option));
 108
 109         return merge;
 110 }
 111
 112
 113 /*XXX: TC_CONFIG_XT_H */
 114 #ifndef TRUE
 115 #define TRUE 1
 116 #endif
 117 #ifndef FALSE
 118 #define FALSE 0
 119 #endif
 120
 121 /*XXX: TC_CONFIG_XT_H */
 122 int
 123 check_inverse(const char option[], int *invert, int *my_optind, int argc)
 124 {
 125         if (option && strcmp(option, "!") == 0) {
 126                 if (*invert)
 127                         exit_error(PARAMETER_PROBLEM,
 128                                    "Multiple `!' flags not allowed");
 129                 *invert = TRUE;
 130                 if (my_optind != NULL) {
 131                         ++*my_optind;
 132                         if (argc && *my_optind > argc)
 133                                 exit_error(PARAMETER_PROBLEM,
 134                                            "no argument following `!'");
 135                 }
 136
 137                 return TRUE;
 138         }
 139         return FALSE;
 140 }
 141
 142 /*XXX: TC_CONFIG_XT_H */
 143 void exit_error(enum exittype status, const char *msg, ...)
 144 {
 145         va_list args;
 146
 147         va_start(args, msg);
 148         fprintf(stderr, "%s v%s: ", pname, pversion);
 149         vfprintf(stderr, msg, args);
 150         va_end(args);
 151         fprintf(stderr, "\n");
 152         /* On error paths, make sure that we don't leak memory */
 153         exit(status);
 154 }
 155
 156 /*XXX: TC_CONFIG_XT_H */
 157 static void set_revision(char *name, u_int8_t revision)
 158 {
 159         /* Old kernel sources don't have ".revision" field,
 160         *  but we stole a byte from name. */
 161         name[IPT_FUNCTION_MAXNAMELEN - 2] = '\0';
 162         name[IPT_FUNCTION_MAXNAMELEN - 1] = revision;
 163 }
 164
 165 /*
 166  * we may need to check for version mismatch
 167 */
 168 int
 169 build_st(struct xtables_target *target, struct xt_entry_target *t)
 170 {
 171
 172         size_t size =
 173                     XT_ALIGN(sizeof (struct xt_entry_target)) + target->size;
 174
 175         if (NULL == t) {
 176                 target->t = fw_calloc(1, size);
 177                 target->t->u.target_size = size;
 178                 strcpy(target->t->u.user.name, target->name);
 179                 set_revision(target->t->u.user.name, target->revision);
 180
 181                 if (target->init != NULL)
 182                         target->init(target->t);
 183         } else {
 184                 target->t = t;
 185         }
 186         return 0;
 187
 188 }
 189
 190 inline void set_lib_dir(void)
 191 {
 192
 193         lib_dir = getenv("XTABLES_LIBDIR");
 194         if (!lib_dir) {
 195                 lib_dir = getenv("IPTABLES_LIB_DIR");
 196                 if (lib_dir)
 197                         fprintf(stderr, "using deprecated IPTABLES_LIB_DIR \n");
 198         }
 199         if (lib_dir == NULL)
 200                 lib_dir = XT_LIB_DIR;
 201
 202 }
 203
 204 static int parse_ipt(struct action_util *a,int *argc_p,
 205                      char ***argv_p, int tca_id, struct nlmsghdr *n)
 206 {
 207         struct xtables_target *m = NULL;
 208         struct ipt_entry fw;
 209         struct rtattr *tail;
 210         int c;
 211         int rargc = *argc_p;
 212         char **argv = *argv_p;
 213         int argc = 0, iargc = 0;
 214         char k[16];
 215         int res = -1;
 216         int size = 0;
 217         int iok = 0, ok = 0;
 218         __u32 hook = 0, index = 0;
 219         res = 0;
 220
 221         set_lib_dir();
 222
 223         {
 224                 int i;
 225                 for (i = 0; i < rargc; i++) {
 226                         if (NULL == argv[i] || 0 == strcmp(argv[i], "action")) {
 227                                 break;
 228                         }
 229                 }
 230                 iargc = argc = i;
 231         }
 232
 233         if (argc <= 2) {
 234                 fprintf(stderr,"bad arguements to ipt %d vs %d \n", argc, rargc);
 235                 return -1;
 236         }
 237
 238         while (1) {
 239                 c = getopt_long(argc, argv, "j:", opts, NULL);
 240                 if (c == -1)
 241                         break;
 242                 switch (c) {
 243                 case 'j':
 244                         m = find_target(optarg, TRY_LOAD);
 245                         if (NULL != m) {
 246
 247                                 if (0 > build_st(m, NULL)) {
 248                                         printf(" %s error \n", m->name);
 249                                         return -1;
 250                                 }
 251                                 opts =
 252                                     merge_options(opts, m->extra_opts,
 253                                                   &m->option_offset);
 254                         } else {
 255                                 fprintf(stderr," failed to find target %s\n\n", optarg);
 256                                 return -1;
 257                         }
 258                         ok++;
 259                         break;
 260
 261                 default:
 262                         memset(&fw, 0, sizeof (fw));
 263                         if (m) {
 264                                 m->parse(c - m->option_offset, argv, 0,
 265                                          &m->tflags, NULL, &m->t);
 266                         } else {
 267                                 fprintf(stderr," failed to find target %s\n\n", optarg);
 268                                 return -1;
 269
 270                         }
 271                         ok++;
 272                         break;
 273
 274                 }
 275         }
 276
 277         if (iargc > optind) {
 278                 if (matches(argv[optind], "index") == 0) {
 279                         if (get_u32(&index, argv[optind + 1], 10)) {
 280                                 fprintf(stderr, "Illegal \"index\"\n");
 281                                 free_opts(opts);
 282                                 return -1;
 283                         }
 284                         iok++;
 285
 286                         optind += 2;
 287                 }
 288         }
 289
 290         if (!ok && !iok) {
 291                 fprintf(stderr," ipt Parser BAD!! (%s)\n", *argv);
 292                 return -1;
 293         }
 294
 295         /* check that we passed the correct parameters to the target */
 296         if (m)
 297                 m->final_check(m->tflags);
 298
 299         {
 300                 struct tcmsg *t = NLMSG_DATA(n);
 301                 if (t->tcm_parent != TC_H_ROOT
 302                     && t->tcm_parent == TC_H_MAJ(TC_H_INGRESS)) {
 303                         hook = NF_IP_PRE_ROUTING;
 304                 } else {
 305                         hook = NF_IP_POST_ROUTING;
 306                 }
 307         }
 308
 309         tail = NLMSG_TAIL(n);
 310         addattr_l(n, MAX_MSG, tca_id, NULL, 0);
 311         fprintf(stdout, "tablename: %s hook: %s\n ", tname, ipthooks[hook]);
 312         fprintf(stdout, "\ttarget: ");
 313
 314         if (m)
 315                 m->print(NULL, m->t, 0);
 316         fprintf(stdout, " index %d\n", index);
 317
 318         if (strlen(tname) > 16) {
 319                 size = 16;
 320                 k[15] = 0;
 321         } else {
 322                 size = 1 + strlen(tname);
 323         }
 324         strncpy(k, tname, size);
 325
 326         addattr_l(n, MAX_MSG, TCA_IPT_TABLE, k, size);
 327         addattr_l(n, MAX_MSG, TCA_IPT_HOOK, &hook, 4);
 328         addattr_l(n, MAX_MSG, TCA_IPT_INDEX, &index, 4);
 329         if (m)
 330                 addattr_l(n, MAX_MSG, TCA_IPT_TARG, m->t, m->t->u.target_size);
 331         tail->rta_len = (void *) NLMSG_TAIL(n) - (void *) tail;
 332
 333         argc -= optind;
 334         argv += optind;
 335         *argc_p = rargc - iargc;
 336         *argv_p = argv;
 337
 338         optind = 0;
 339         free_opts(opts);
 340         /* Clear flags if target will be used again */
 341         m->tflags=0;
 342         m->used=0;
 343         /* Free allocated memory */
 344         if (m->t)
 345             free(m->t);
 346
 347
 348         return 0;
 349
 350 }
 351
 352 static int
 353 print_ipt(struct action_util *au,FILE * f, struct rtattr *arg)
 354 {
 355         struct rtattr *tb[TCA_IPT_MAX + 1];
 356         struct xt_entry_target *t = NULL;
 357
 358         if (arg == NULL)
 359                 return -1;
 360
 361         set_lib_dir();
 362
 363         parse_rtattr_nested(tb, TCA_IPT_MAX, arg);
 364
 365         if (tb[TCA_IPT_TABLE] == NULL) {
 366                 fprintf(f, "[NULL ipt table name ] assuming mangle ");
 367         } else {
 368                 fprintf(f, "tablename: %s ",
 369                         (char *) RTA_DATA(tb[TCA_IPT_TABLE]));
 370         }
 371
 372         if (tb[TCA_IPT_HOOK] == NULL) {
 373                 fprintf(f, "[NULL ipt hook name ]\n ");
 374                 return -1;
 375         } else {
 376                 __u32 hook;
 377                 hook = *(__u32 *) RTA_DATA(tb[TCA_IPT_HOOK]);
 378                 fprintf(f, " hook: %s \n", ipthooks[hook]);
 379         }
 380
 381         if (tb[TCA_IPT_TARG] == NULL) {
 382                 fprintf(f, "\t[NULL ipt target parameters ] \n");
 383                 return -1;
 384         } else {
 385                 struct xtables_target *m = NULL;
 386                 t = RTA_DATA(tb[TCA_IPT_TARG]);
 387                 m = find_target(t->u.user.name, TRY_LOAD);
 388                 if (NULL != m) {
 389                         if (0 > build_st(m, t)) {
 390                                 fprintf(stderr, " %s error \n", m->name);
 391                                 return -1;
 392                         }
 393
 394                         opts =
 395                             merge_options(opts, m->extra_opts,
 396                                           &m->option_offset);
 397                 } else {
 398                         fprintf(stderr, " failed to find target %s\n\n",
 399                                 t->u.user.name);
 400                         return -1;
 401                 }
 402                 fprintf(f, "\ttarget ");
 403                 m->print(NULL, m->t, 0);
 404                 if (tb[TCA_IPT_INDEX] == NULL) {
 405                         fprintf(f, " [NULL ipt target index ]\n");
 406                 } else {
 407                         __u32 index;
 408                         index = *(__u32 *) RTA_DATA(tb[TCA_IPT_INDEX]);
 409                         fprintf(f, " \n\tindex %d", index);
 410                 }
 411
 412                 if (tb[TCA_IPT_CNT]) {
 413                         struct tc_cnt *c  = RTA_DATA(tb[TCA_IPT_CNT]);;
 414                         fprintf(f, " ref %d bind %d", c->refcnt, c->bindcnt);
 415                 }
 416                 if (show_stats) {
 417                         if (tb[TCA_IPT_TM]) {
 418                                 struct tcf_t *tm = RTA_DATA(tb[TCA_IPT_TM]);
 419                                 print_tm(f,tm);
 420                         }
 421                 }
 422                 fprintf(f, " \n");
 423
 424         }
 425         free_opts(opts);
 426
 427         return 0;
 428 }
 429
 430 struct action_util ipt_action_util = {
 431         .id = "ipt",
 432         .parse_aopt = parse_ipt,
 433         .print_aopt = print_ipt,
 434 };
 435