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 res = -1;
 128         int size = 0;
 129         int iok = 0, ok = 0;
 130         __u32 hook = 0, index = 0;
 131         res = 0;
 132
 133         xtables_init_all(&tcipt_globals, NFPROTO_IPV4);
 134         set_lib_dir();
 135
 136         {
 137                 int i;
 138                 for (i = 0; i < rargc; i++) {
 139                         if (NULL == argv[i] || 0 == strcmp(argv[i], "action")) {
 140                                 break;
 141                         }
 142                 }
 143                 iargc = argc = i;
 144         }
 145
 146         if (argc <= 2) {
 147                 fprintf(stderr,"bad arguements to ipt %d vs %d \n", argc, rargc);
 148                 return -1;
 149         }
 150
 151         while (1) {
 152                 c = getopt_long(argc, argv, "j:", tcipt_globals.opts, NULL);
 153                 if (c == -1)
 154                         break;
 155                 switch (c) {
 156                 case 'j':
 157                         m = xtables_find_target(optarg, XTF_TRY_LOAD);
 158                         if (NULL != m) {
 159
 160                                 if (0 > build_st(m, NULL)) {
 161                                         printf(" %s error \n", m->name);
 162                                         return -1;
 163                                 }
 164                                 tcipt_globals.opts =
 165                                     xtables_merge_options(tcipt_globals.opts,
 166                                                           m->extra_opts,
 167                                                           &m->option_offset);
 168                         } else {
 169                                 fprintf(stderr," failed to find target %s\n\n", optarg);
 170                                 return -1;
 171                         }
 172                         ok++;
 173                         break;
 174
 175                 default:
 176                         memset(&fw, 0, sizeof (fw));
 177                         if (m) {
 178                                 m->parse(c - m->option_offset, argv, 0,
 179                                          &m->tflags, NULL, &m->t);
 180                         } else {
 181                                 fprintf(stderr," failed to find target %s\n\n", optarg);
 182                                 return -1;
 183
 184                         }
 185                         ok++;
 186                         break;
 187
 188                 }
 189         }
 190
 191         if (iargc > optind) {
 192                 if (matches(argv[optind], "index") == 0) {
 193                         if (get_u32(&index, argv[optind + 1], 10)) {
 194                                 fprintf(stderr, "Illegal \"index\"\n");
 195                                 xtables_free_opts(1);
 196                                 return -1;
 197                         }
 198                         iok++;
 199
 200                         optind += 2;
 201                 }
 202         }
 203
 204         if (!ok && !iok) {
 205                 fprintf(stderr," ipt Parser BAD!! (%s)\n", *argv);
 206                 return -1;
 207         }
 208
 209         /* check that we passed the correct parameters to the target */
 210         if (m && m->final_check)
 211                 m->final_check(m->tflags);
 212
 213         {
 214                 struct tcmsg *t = NLMSG_DATA(n);
 215                 if (t->tcm_parent != TC_H_ROOT
 216                     && t->tcm_parent == TC_H_MAJ(TC_H_INGRESS)) {
 217                         hook = NF_IP_PRE_ROUTING;
 218                 } else {
 219                         hook = NF_IP_POST_ROUTING;
 220                 }
 221         }
 222
 223         tail = NLMSG_TAIL(n);
 224         addattr_l(n, MAX_MSG, tca_id, NULL, 0);
 225         fprintf(stdout, "tablename: %s hook: %s\n ", tname, ipthooks[hook]);
 226         fprintf(stdout, "\ttarget: ");
 227
 228         if (m)
 229                 m->print(NULL, m->t, 0);
 230         fprintf(stdout, " index %d\n", index);
 231
 232         if (strlen(tname) > 16) {
 233                 size = 16;
 234                 k[15] = 0;
 235         } else {
 236                 size = 1 + strlen(tname);
 237         }
 238         strncpy(k, tname, size);
 239
 240         addattr_l(n, MAX_MSG, TCA_IPT_TABLE, k, size);
 241         addattr_l(n, MAX_MSG, TCA_IPT_HOOK, &hook, 4);
 242         addattr_l(n, MAX_MSG, TCA_IPT_INDEX, &index, 4);
 243         if (m)
 244                 addattr_l(n, MAX_MSG, TCA_IPT_TARG, m->t, m->t->u.target_size);
 245         tail->rta_len = (void *) NLMSG_TAIL(n) - (void *) tail;
 246
 247         argc -= optind;
 248         argv += optind;
 249         *argc_p = rargc - iargc;
 250         *argv_p = argv;
 251
 252         optind = 0;
 253         xtables_free_opts(1);
 254         /* Clear flags if target will be used again */
 255         m->tflags=0;
 256         m->used=0;
 257         /* Free allocated memory */
 258         if (m->t)
 259             free(m->t);
 260
 261
 262         return 0;
 263
 264 }
 265
 266 static int
 267 print_ipt(struct action_util *au,FILE * f, struct rtattr *arg)
 268 {
 269         struct rtattr *tb[TCA_IPT_MAX + 1];
 270         struct xt_entry_target *t = NULL;
 271
 272         if (arg == NULL)
 273                 return -1;
 274
 275         xtables_init_all(&tcipt_globals, NFPROTO_IPV4);
 276         set_lib_dir();
 277
 278         parse_rtattr_nested(tb, TCA_IPT_MAX, arg);
 279
 280         if (tb[TCA_IPT_TABLE] == NULL) {
 281                 fprintf(f, "[NULL ipt table name ] assuming mangle ");
 282         } else {
 283                 fprintf(f, "tablename: %s ",
 284                         (char *) RTA_DATA(tb[TCA_IPT_TABLE]));
 285         }
 286
 287         if (tb[TCA_IPT_HOOK] == NULL) {
 288                 fprintf(f, "[NULL ipt hook name ]\n ");
 289                 return -1;
 290         } else {
 291                 __u32 hook;
 292                 hook = *(__u32 *) RTA_DATA(tb[TCA_IPT_HOOK]);
 293                 fprintf(f, " hook: %s \n", ipthooks[hook]);
 294         }
 295
 296         if (tb[TCA_IPT_TARG] == NULL) {
 297                 fprintf(f, "\t[NULL ipt target parameters ] \n");
 298                 return -1;
 299         } else {
 300                 struct xtables_target *m = NULL;
 301                 t = RTA_DATA(tb[TCA_IPT_TARG]);
 302                 m = xtables_find_target(t->u.user.name, XTF_TRY_LOAD);
 303                 if (NULL != m) {
 304                         if (0 > build_st(m, t)) {
 305                                 fprintf(stderr, " %s error \n", m->name);
 306                                 return -1;
 307                         }
 308
 309                         tcipt_globals.opts =
 310                             xtables_merge_options(tcipt_globals.opts,
 311                                                   m->extra_opts,
 312                                                   &m->option_offset);
 313                 } else {
 314                         fprintf(stderr, " failed to find target %s\n\n",
 315                                 t->u.user.name);
 316                         return -1;
 317                 }
 318                 fprintf(f, "\ttarget ");
 319                 m->print(NULL, m->t, 0);
 320                 if (tb[TCA_IPT_INDEX] == NULL) {
 321                         fprintf(f, " [NULL ipt target index ]\n");
 322                 } else {
 323                         __u32 index;
 324                         index = *(__u32 *) RTA_DATA(tb[TCA_IPT_INDEX]);
 325                         fprintf(f, " \n\tindex %d", index);
 326                 }
 327
 328                 if (tb[TCA_IPT_CNT]) {
 329                         struct tc_cnt *c  = RTA_DATA(tb[TCA_IPT_CNT]);;
 330                         fprintf(f, " ref %d bind %d", c->refcnt, c->bindcnt);
 331                 }
 332                 if (show_stats) {
 333                         if (tb[TCA_IPT_TM]) {
 334                                 struct tcf_t *tm = RTA_DATA(tb[TCA_IPT_TM]);
 335                                 print_tm(f,tm);
 336                         }
 337                 }
 338                 fprintf(f, " \n");
 339
 340         }
 341         xtables_free_opts(1);
 342
 343         return 0;
 344 }
 345
 346 struct action_util ipt_action_util = {
 347         .id = "ipt",
 348         .parse_aopt = parse_ipt,
 349         .print_aopt = print_ipt,
 350 };
 351