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 (at) 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 rta_getattr_str(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 = rta_getattr_u32(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 = rta_getattr_u32(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 xt_action_util = { 354 .id = "xt", 355 .parse_aopt = parse_ipt, 356 .print_aopt = print_ipt, 357 }; 358 359
