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