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_KERNEL
  42 #define __ALIGN_KERNEL(x, a)            __ALIGN_KERNEL_MASK(x, (typeof(x))(a) - 1)
  43 #define __ALIGN_KERNEL_MASK(x, mask)    (((x) + (mask)) & ~(mask))
  44 #endif
  45
  46 #ifndef ALIGN
  47 #define ALIGN(x,a)      __ALIGN_KERNEL((x), (a))
  48 #endif
  49
  50 static const char *tname = "mangle";
  51
  52 char *lib_dir;
  53
  54 static const char *ipthooks[] = {
  55         "NF_IP_PRE_ROUTING",
  56         "NF_IP_LOCAL_IN",
  57         "NF_IP_FORWARD",
  58         "NF_IP_LOCAL_OUT",
  59         "NF_IP_POST_ROUTING",
  60 };
  61
  62 static struct option original_opts[] = {
  63         {
  64                 .name = "jump",
  65                 .has_arg = 1,
  66                 .val = 'j'
  67         },
  68         {0, 0, 0, 0}
  69 };
  70
  71 static struct xtables_globals tcipt_globals = {
  72         .option_offset = 0,
  73         .program_name = "tc-ipt",
  74         .program_version = "0.2",
  75         .orig_opts = original_opts,
  76         .opts = original_opts,
  77         .exit_err = NULL,
  78 };
  79
  80 /*
  81  * we may need to check for version mismatch
  82 */
  83 static int
  84 build_st(struct xtables_target *target, struct xt_entry_target *t)
  85 {
  86
  87         size_t size =
  88                     XT_ALIGN(sizeof (struct xt_entry_target)) + target->size;
  89
  90         if (NULL == t) {
  91                 target->t = xtables_calloc(1, size);
  92                 target->t->u.target_size = size;
  93                 strcpy(target->t->u.user.name, target->name);
  94                 target->t->u.user.revision = target->revision;
  95
  96                 if (target->init != NULL)
  97                         target->init(target->t);
  98         } else {
  99                 target->t = t;
 100         }
 101         return 0;
 102
 103 }
 104
 105 static void set_lib_dir(void)
 106 {
 107
 108         lib_dir = getenv("XTABLES_LIBDIR");
 109         if (!lib_dir) {
 110                 lib_dir = getenv("IPTABLES_LIB_DIR");
 111                 if (lib_dir)
 112                         fprintf(stderr, "using deprecated IPTABLES_LIB_DIR \n");
 113         }
 114         if (lib_dir == NULL)
 115                 lib_dir = XT_LIB_DIR;
 116
 117 }
 118
 119 static int parse_ipt(struct action_util *a,int *argc_p,
 120                      char ***argv_p, int tca_id, struct nlmsghdr *n)
 121 {
 122         struct xtables_target *m = NULL;
 123         struct ipt_entry fw;
 124         struct rtattr *tail;
 125
 126         int c;
 127         int rargc = *argc_p;
 128         char **argv = *argv_p;
 129         int argc = 0, iargc = 0;
 130         char k[16];
 131         int size = 0;
 132         int iok = 0, ok = 0;
 133         __u32 hook = 0, index = 0;
 134         struct option *opts = NULL;
 135
 136         xtables_init_all(&tcipt_globals, NFPROTO_IPV4);
 137         set_lib_dir();
 138
 139         {
 140                 int i;
 141                 for (i = 0; i < rargc; i++) {
 142                         if (NULL == argv[i] || 0 == strcmp(argv[i], "action")) {
 143                                 break;
 144                         }
 145                 }
 146                 iargc = argc = i;
 147         }
 148
 149         if (argc <= 2) {
 150                 fprintf(stderr,"bad arguments to ipt %d vs %d \n", argc, rargc);
 151                 return -1;
 152         }
 153
 154         while (1) {
 155                 c = getopt_long(argc, argv, "j:", tcipt_globals.opts, NULL);
 156                 if (c == -1)
 157                         break;
 158                 switch (c) {
 159                 case 'j':
 160                         m = xtables_find_target(optarg, XTF_TRY_LOAD);
 161                         if (NULL != m) {
 162
 163                                 if (0 > build_st(m, NULL)) {
 164                                         printf(" %s error \n", m->name);
 165                                         return -1;
 166                                 }
 167 #if (XTABLES_VERSION_CODE >= 6)
 168                         opts = xtables_options_xfrm(tcipt_globals.orig_opts,
 169                                                     tcipt_globals.opts,
 170                                                     m->x6_options,
 171                                                     &m->option_offset);
 172 #else
 173                         opts = xtables_merge_options(tcipt_globals.opts,
 174                                                      m->extra_opts,
 175                                                      &m->option_offset);
 176 #endif
 177                         if (opts == NULL) {
 178                                 fprintf(stderr, " failed to find additional options for target %s\n\n", optarg);
 179                                 return -1;
 180                         } else
 181                                 tcipt_globals.opts = opts;
 182                         } else {
 183                                 fprintf(stderr," failed to find target %s\n\n", optarg);
 184                                 return -1;
 185                         }
 186                         ok++;
 187                         break;
 188
 189                 default:
 190                         memset(&fw, 0, sizeof (fw));
 191 #if (XTABLES_VERSION_CODE >= 6)
 192                 if (m != NULL && m->x6_parse != NULL ) {
 193                         xtables_option_tpcall(c, argv, 0 , m, NULL);
 194 #else
 195                 if (m != NULL && m->parse != NULL ) {
 196                         m->parse(c - m->option_offset, argv, 0, &m->tflags,
 197                                  NULL, &m->t);
 198 #endif
 199                         } else {
 200                                 fprintf(stderr,"failed to find target %s\n\n", optarg);
 201                                 return -1;
 202
 203                         }
 204                         ok++;
 205                         break;
 206                 }
 207         }
 208
 209         if (iargc > optind) {
 210                 if (matches(argv[optind], "index") == 0) {
 211                         if (get_u32(&index, argv[optind + 1], 10)) {
 212                                 fprintf(stderr, "Illegal \"index\"\n");
 213                                 xtables_free_opts(1);
 214                                 return -1;
 215                         }
 216                         iok++;
 217
 218                         optind += 2;
 219                 }
 220         }
 221
 222         if (!ok && !iok) {
 223                 fprintf(stderr," ipt Parser BAD!! (%s)\n", *argv);
 224                 return -1;
 225         }
 226
 227         /* check that we passed the correct parameters to the target */
 228 #if (XTABLES_VERSION_CODE >= 6)
 229         if (m)
 230                 xtables_option_tfcall(m);
 231 #else
 232         if (m && m->final_check)
 233                 m->final_check(m->tflags);
 234 #endif
 235
 236         {
 237                 struct tcmsg *t = NLMSG_DATA(n);
 238                 if (t->tcm_parent != TC_H_ROOT
 239                     && t->tcm_parent == TC_H_MAJ(TC_H_INGRESS)) {
 240                         hook = NF_IP_PRE_ROUTING;
 241                 } else {
 242                         hook = NF_IP_POST_ROUTING;
 243                 }
 244         }
 245
 246         tail = NLMSG_TAIL(n);
 247         addattr_l(n, MAX_MSG, tca_id, NULL, 0);
 248         fprintf(stdout, "tablename: %s hook: %s\n ", tname, ipthooks[hook]);
 249         fprintf(stdout, "\ttarget: ");
 250
 251         if (m)
 252                 m->print(NULL, m->t, 0);
 253         fprintf(stdout, " index %d\n", index);
 254
 255         if (strlen(tname) > 16) {
 256                 size = 16;
 257                 k[15] = 0;
 258         } else {
 259                 size = 1 + strlen(tname);
 260         }
 261         strncpy(k, tname, size);
 262
 263         addattr_l(n, MAX_MSG, TCA_IPT_TABLE, k, size);
 264         addattr_l(n, MAX_MSG, TCA_IPT_HOOK, &hook, 4);
 265         addattr_l(n, MAX_MSG, TCA_IPT_INDEX, &index, 4);
 266         if (m)
 267                 addattr_l(n, MAX_MSG, TCA_IPT_TARG, m->t, m->t->u.target_size);
 268         tail->rta_len = (void *) NLMSG_TAIL(n) - (void *) tail;
 269
 270         argc -= optind;
 271         argv += optind;
 272         *argc_p = rargc - iargc;
 273         *argv_p = argv;
 274
 275         optind = 0;
 276         xtables_free_opts(1);
 277
 278         if (m) {
 279                 /* Clear flags if target will be used again */
 280                 m->tflags = 0;
 281                 m->used = 0;
 282                 /* Free allocated memory */
 283                 if (m->t)
 284                         free(m->t);
 285         }
 286
 287         return 0;
 288
 289 }
 290
 291 static int
 292 print_ipt(struct action_util *au,FILE * f, struct rtattr *arg)
 293 {
 294         struct rtattr *tb[TCA_IPT_MAX + 1];
 295         struct xt_entry_target *t = NULL;
 296         struct option *opts = NULL;
 297
 298         if (arg == NULL)
 299                 return -1;
 300
 301         /* copy tcipt_globals because .opts will be modified by iptables */
 302         struct xtables_globals tmp_tcipt_globals = tcipt_globals;
 303
 304         xtables_init_all(&tmp_tcipt_globals, NFPROTO_IPV4);
 305         set_lib_dir();
 306
 307         parse_rtattr_nested(tb, TCA_IPT_MAX, arg);
 308
 309         if (tb[TCA_IPT_TABLE] == NULL) {
 310                 fprintf(f, "[NULL ipt table name ] assuming mangle ");
 311         } else {
 312                 fprintf(f, "tablename: %s ",
 313                         rta_getattr_str(tb[TCA_IPT_TABLE]));
 314         }
 315
 316         if (tb[TCA_IPT_HOOK] == NULL) {
 317                 fprintf(f, "[NULL ipt hook name ]\n ");
 318                 return -1;
 319         } else {
 320                 __u32 hook;
 321                 hook = rta_getattr_u32(tb[TCA_IPT_HOOK]);
 322                 fprintf(f, " hook: %s \n", ipthooks[hook]);
 323         }
 324
 325         if (tb[TCA_IPT_TARG] == NULL) {
 326                 fprintf(f, "\t[NULL ipt target parameters ] \n");
 327                 return -1;
 328         } else {
 329                 struct xtables_target *m = NULL;
 330                 t = RTA_DATA(tb[TCA_IPT_TARG]);
 331                 m = xtables_find_target(t->u.user.name, XTF_TRY_LOAD);
 332                 if (NULL != m) {
 333                         if (0 > build_st(m, t)) {
 334                                 fprintf(stderr, " %s error \n", m->name);
 335                                 return -1;
 336                         }
 337
 338 #if (XTABLES_VERSION_CODE >= 6)
 339                 opts = xtables_options_xfrm(tmp_tcipt_globals.orig_opts,
 340                                             tmp_tcipt_globals.opts,
 341                                             m->x6_options,
 342                                             &m->option_offset);
 343 #else
 344                 opts = xtables_merge_options(tmp_tcipt_globals.opts,
 345                                              m->extra_opts,
 346                                              &m->option_offset);
 347 #endif
 348         if (opts == NULL) {
 349                 fprintf(stderr, " failed to find additional options for target %s\n\n", optarg);
 350                 return -1;
 351         } else
 352                 tmp_tcipt_globals.opts = opts;
 353                 } else {
 354                         fprintf(stderr, " failed to find target %s\n\n",
 355                                 t->u.user.name);
 356                         return -1;
 357                 }
 358                 fprintf(f, "\ttarget ");
 359                 m->print(NULL, m->t, 0);
 360                 if (tb[TCA_IPT_INDEX] == NULL) {
 361                         fprintf(f, " [NULL ipt target index ]\n");
 362                 } else {
 363                         __u32 index;
 364                         index = rta_getattr_u32(tb[TCA_IPT_INDEX]);
 365                         fprintf(f, " \n\tindex %d", index);
 366                 }
 367
 368                 if (tb[TCA_IPT_CNT]) {
 369                         struct tc_cnt *c  = RTA_DATA(tb[TCA_IPT_CNT]);;
 370                         fprintf(f, " ref %d bind %d", c->refcnt, c->bindcnt);
 371                 }
 372                 if (show_stats) {
 373                         if (tb[TCA_IPT_TM]) {
 374                                 struct tcf_t *tm = RTA_DATA(tb[TCA_IPT_TM]);
 375                                 print_tm(f,tm);
 376                         }
 377                 }
 378                 fprintf(f, " \n");
 379
 380         }
 381         xtables_free_opts(1);
 382
 383         return 0;
 384 }
 385
 386 struct action_util xt_action_util = {
 387         .id = "xt",
 388         .parse_aopt = parse_ipt,
 389         .print_aopt = print_ipt,
 390 };