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 #include <syslog.h>
  14 #include <sys/socket.h>
  15 #include <netinet/in.h>
  16 #include <arpa/inet.h>
  17 #include <net/if.h>
  18 #include <limits.h>
  19 #include <linux/netfilter.h>
  20 #include <linux/netfilter_ipv4/ip_tables.h>
  21 #include <xtables.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 <unistd.h>
  35 #include <fcntl.h>
  36 #include <sys/wait.h>
  37 #ifndef XT_LIB_DIR
  38 #       define XT_LIB_DIR "/lib/xtables"
  39 #endif
  40
  41 #ifndef ALIGN
  42 #define ALIGN(x,a)              __ALIGN_MASK(x,(typeof(x))(a)-1)
  43 #define __ALIGN_MASK(x,mask)    (((x)+(mask))&~(mask))
  44 #endif
  45
  46 static const char *tname = "mangle";
  47
  48 char *lib_dir;
  49
  50 static const char *ipthooks[] = {
  51         "NF_IP_PRE_ROUTING",
  52         "NF_IP_LOCAL_IN",
  53         "NF_IP_FORWARD",
  54         "NF_IP_LOCAL_OUT",
  55         "NF_IP_POST_ROUTING",
  56 };
  57
  58 static struct option original_opts[] = {
  59         {
  60                 .name = "jump",
  61                 .has_arg = 1,
  62                 .val = 'j'
  63         },
  64         {0, 0, 0, 0}
  65 };
  66
  67 static struct xtables_globals tcipt_globals = {
  68         .option_offset = 0,
  69         .program_name = "tc-ipt",
  70         .program_version = "0.2",
  71         .orig_opts = original_opts,
  72         .opts = original_opts,
  73         .exit_err = NULL,
  74 };
  75
  76 /*
  77  * we may need to check for version mismatch
  78 */
  79 int
  80 build_st(struct xtables_target *target, struct xt_entry_target *t)
  81 {
  82
  83         size_t size =
  84                     XT_ALIGN(sizeof (struct xt_entry_target)) + target->size;
  85
  86         if (NULL == t) {
  87                 target->t = xtables_calloc(1, size);
  88                 target->t->u.target_size = size;
  89                 strcpy(target->t->u.user.name, target->name);
  90                 target->t->u.user.revision = target->revision;
  91
  92                 if (target->init != NULL)
  93                         target->init(target->t);
  94         } else {
  95                 target->t = t;
  96         }
  97         return 0;
  98
  99 }
 100
 101 inline void set_lib_dir(void)
 102 {
 103
 104         lib_dir = getenv("XTABLES_LIBDIR");
 105         if (!lib_dir) {
 106                 lib_dir = getenv("IPTABLES_LIB_DIR");
 107                 if (lib_dir)
 108                         fprintf(stderr, "using deprecated IPTABLES_LIB_DIR \n");
 109         }
 110         if (lib_dir == NULL)
 111                 lib_dir = XT_LIB_DIR;
 112
 113 }
 114
 115 static int parse_ipt(struct action_util *a,int *argc_p,
 116                      char ***argv_p, int tca_id, struct nlmsghdr *n)
 117 {
 118         struct xtables_target *m = NULL;
 119         struct ipt_entry fw;
 120         struct rtattr *tail;
 121         int c;
 122         int rargc = *argc_p;
 123         char **argv = *argv_p;
 124         int argc = 0, iargc = 0;
 125         char k[16];
 126         int size = 0;
 127         int iok = 0, ok = 0;
 128         __u32 hook = 0, index = 0;
 129
 130         xtables_init_all(&tcipt_globals, NFPROTO_IPV4);
 131         set_lib_dir();
 132
 133         {
 134                 int i;
 135                 for (i = 0; i < rargc; i++) {
 136                         if (NULL == argv[i] || 0 == strcmp(argv[i], "action")) {
 137                                 break;
 138                         }
 139                 }
 140                 iargc = argc = i;
 141         }
 142
 143         if (argc <= 2) {
 144                 fprintf(stderr,"bad arguements to ipt %d vs %d \n", argc, rargc);
 145                 return -1;
 146         }
 147
 148         while (1) {
 149                 c = getopt_long(argc, argv, "j:", tcipt_globals.opts, NULL);
 150                 if (c == -1)
 151                         break;
 152                 switch (c) {
 153                 case 'j':
 154                         m = xtables_find_target(optarg, XTF_TRY_LOAD);
 155                         if (NULL != m) {
 156
 157                                 if (0 > build_st(m, NULL)) {
 158                                         printf(" %s error \n", m->name);
 159                                         return -1;
 160                                 }
 161                                 tcipt_globals.opts =
 162                                     xtables_merge_options(
 163 #if (XTABLES_VERSION_CODE >= 6)
 164                                         tcipt_globals.orig_opts,
 165 #endif
 166                                         tcipt_globals.opts,
 167                                         m->extra_opts,
 168                                         &m->option_offset);
 169                         } else {
 170                                 fprintf(stderr," failed to find target %s\n\n", optarg);
 171                                 return -1;
 172                         }
 173                         ok++;
 174                         break;
 175
 176                 default:
 177                         memset(&fw, 0, sizeof (fw));
 178                         if (m) {
 179                                 m->parse(c - m->option_offset, argv, 0,
 180                                          &m->tflags, NULL, &m->t);
 181                         } else {
 182                                 fprintf(stderr," failed to find target %s\n\n", optarg);
 183                                 return -1;
 184
 185                         }
 186                         ok++;
 187                         break;
 188
 189                 }
 190         }
 191
 192         if (iargc > optind) {
 193                 if (matches(argv[optind], "index") == 0) {
 194                         if (get_u32(&index, argv[optind + 1], 10)) {
 195                                 fprintf(stderr, "Illegal \"index\"\n");
 196                                 xtables_free_opts(1);
 197                                 return -1;
 198                         }
 199                         iok++;
 200
 201                         optind += 2;
 202                 }
 203         }
 204
 205         if (!ok && !iok) {
 206                 fprintf(stderr," ipt Parser BAD!! (%s)\n", *argv);
 207                 return -1;
 208         }
 209
 210         /* check that we passed the correct parameters to the target */
 211         if (m && m->final_check)
 212                 m->final_check(m->tflags);
 213
 214         {
 215                 struct tcmsg *t = NLMSG_DATA(n);
 216                 if (t->tcm_parent != TC_H_ROOT
 217                     && t->tcm_parent == TC_H_MAJ(TC_H_INGRESS)) {
 218                         hook = NF_IP_PRE_ROUTING;
 219                 } else {
 220                         hook = NF_IP_POST_ROUTING;
 221                 }
 222         }
 223
 224         tail = NLMSG_TAIL(n);
 225         addattr_l(n, MAX_MSG, tca_id, NULL, 0);
 226         fprintf(stdout, "tablename: %s hook: %s\n ", tname, ipthooks[hook]);
 227         fprintf(stdout, "\ttarget: ");
 228
 229         if (m)
 230                 m->print(NULL, m->t, 0);
 231         fprintf(stdout, " index %d\n", index);
 232
 233         if (strlen(tname) > 16) {
 234                 size = 16;
 235                 k[15] = 0;
 236         } else {
 237                 size = 1 + strlen(tname);
 238         }
 239         strncpy(k, tname, size);
 240
 241         addattr_l(n, MAX_MSG, TCA_IPT_TABLE, k, size);
 242         addattr_l(n, MAX_MSG, TCA_IPT_HOOK, &hook, 4);
 243         addattr_l(n, MAX_MSG, TCA_IPT_INDEX, &index, 4);
 244         if (m)
 245                 addattr_l(n, MAX_MSG, TCA_IPT_TARG, m->t, m->t->u.target_size);
 246         tail->rta_len = (void *) NLMSG_TAIL(n) - (void *) tail;
 247
 248         argc -= optind;
 249         argv += optind;
 250         *argc_p = rargc - iargc;
 251         *argv_p = argv;
 252
 253         optind = 0;
 254         xtables_free_opts(1);
 255
 256         if (m) {
 257                 /* Clear flags if target will be used again */
 258                 m->tflags = 0;
 259                 m->used = 0;
 260                 /* Free allocated memory */
 261                 if (m->t)
 262                         free(m->t);
 263         }
 264
 265         return 0;
 266
 267 }
 268
 269 static int
 270 print_ipt(struct action_util *au,FILE * f, struct rtattr *arg)
 271 {
 272         struct rtattr *tb[TCA_IPT_MAX + 1];
 273         struct xt_entry_target *t = NULL;
 274
 275         if (arg == NULL)
 276                 return -1;
 277
 278         xtables_init_all(&tcipt_globals, NFPROTO_IPV4);
 279         set_lib_dir();
 280
 281         parse_rtattr_nested(tb, TCA_IPT_MAX, arg);
 282
 283         if (tb[TCA_IPT_TABLE] == NULL) {
 284                 fprintf(f, "[NULL ipt table name ] assuming mangle ");
 285         } else {
 286                 fprintf(f, "tablename: %s ",
 287                         (char *) RTA_DATA(tb[TCA_IPT_TABLE]));
 288         }
 289
 290         if (tb[TCA_IPT_HOOK] == NULL) {
 291                 fprintf(f, "[NULL ipt hook name ]\n ");
 292                 return -1;
 293         } else {
 294                 __u32 hook;
 295                 hook = *(__u32 *) RTA_DATA(tb[TCA_IPT_HOOK]);
 296                 fprintf(f, " hook: %s \n", ipthooks[hook]);
 297         }
 298
 299         if (tb[TCA_IPT_TARG] == NULL) {
 300                 fprintf(f, "\t[NULL ipt target parameters ] \n");
 301                 return -1;
 302         } else {
 303                 struct xtables_target *m = NULL;
 304                 t = RTA_DATA(tb[TCA_IPT_TARG]);
 305                 m = xtables_find_target(t->u.user.name, XTF_TRY_LOAD);
 306                 if (NULL != m) {
 307                         if (0 > build_st(m, t)) {
 308                                 fprintf(stderr, " %s error \n", m->name);
 309                                 return -1;
 310                         }
 311
 312                         tcipt_globals.opts =
 313                             xtables_merge_options(
 314 #if (XTABLES_VERSION_CODE >= 6)
 315                                                   tcipt_globals.orig_opts,
 316 #endif
 317                                                   tcipt_globals.opts,
 318                                                   m->extra_opts,
 319                                                   &m->option_offset);
 320                 } else {
 321                         fprintf(stderr, " failed to find target %s\n\n",
 322                                 t->u.user.name);
 323                         return -1;
 324                 }
 325                 fprintf(f, "\ttarget ");
 326                 m->print(NULL, m->t, 0);
 327                 if (tb[TCA_IPT_INDEX] == NULL) {
 328                         fprintf(f, " [NULL ipt target index ]\n");
 329                 } else {
 330                         __u32 index;
 331                         index = *(__u32 *) RTA_DATA(tb[TCA_IPT_INDEX]);
 332                         fprintf(f, " \n\tindex %d", index);
 333                 }
 334
 335                 if (tb[TCA_IPT_CNT]) {
 336                         struct tc_cnt *c  = RTA_DATA(tb[TCA_IPT_CNT]);;
 337                         fprintf(f, " ref %d bind %d", c->refcnt, c->bindcnt);
 338                 }
 339                 if (show_stats) {
 340                         if (tb[TCA_IPT_TM]) {
 341                                 struct tcf_t *tm = RTA_DATA(tb[TCA_IPT_TM]);
 342                                 print_tm(f,tm);
 343                         }
 344                 }
 345                 fprintf(f, " \n");
 346
 347         }
 348         xtables_free_opts(1);
 349
 350         return 0;
 351 }
 352
 353 struct action_util ipt_action_util = {
 354         .id = "ipt",
 355         .parse_aopt = parse_ipt,
 356         .print_aopt = print_ipt,
 357 };
 358