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