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 /*XXX: in the future (xtables 1.4.3?) get rid of everything tagged
14 * as TC_CONFIG_XT_H */
15
16 #include <syslog.h>
17 #include <sys/socket.h>
18 #include <netinet/in.h>
19 #include <arpa/inet.h>
20 #include <net/if.h>
21 #include <linux/netfilter.h>
22 #include <linux/netfilter_ipv4/ip_tables.h>
23 #include <xtables.h>
24 #include "utils.h"
25 #include "tc_util.h"
26 #include <linux/tc_act/tc_ipt.h>
27 #include <stdio.h>
28 #include <getopt.h>
29 #include <errno.h>
30 #include <string.h>
31 #include <netdb.h>
32 #include <stdlib.h>
33 #include <ctype.h>
34 #include <stdarg.h>
35 #include <limits.h>
36 #include <unistd.h>
37 #include <fcntl.h>
38 #include <sys/wait.h>
39 #ifdef TC_CONFIG_XT_H
40 #include "xt-internal.h"
41 #endif
42
43 #ifndef ALIGN
44 #define ALIGN(x, a) __ALIGN_MASK(x, (typeof(x))(a)-1)
45 #define __ALIGN_MASK(x, mask) (((x)+(mask))&~(mask))
46 #endif
47
48 static const char *pname = "tc-ipt";
49 static const char *tname = "mangle";
50 static const char *pversion = "0.2";
51
52 static const char *ipthooks[] = {
53 "NF_IP_PRE_ROUTING",
54 "NF_IP_LOCAL_IN",
55 "NF_IP_FORWARD",
56 "NF_IP_LOCAL_OUT",
57 "NF_IP_POST_ROUTING",
58 };
59
60 static struct option original_opts[] = {
61 {"jump", 1, 0, 'j'},
62 {0, 0, 0, 0}
63 };
64
65 static struct option *opts = original_opts;
66 static unsigned int global_option_offset;
67 char *lib_dir;
68 const char *program_version = XTABLES_VERSION;
69 const char *program_name = "tc-ipt";
70 struct afinfo afinfo = {
71 .family = AF_INET,
72 .libprefix = "libxt_",
73 .ipproto = IPPROTO_IP,
74 .kmod = "ip_tables",
75 .so_rev_target = IPT_SO_GET_REVISION_TARGET,
76 };
77
78
79 #define OPTION_OFFSET 256
80
81 /*XXX: TC_CONFIG_XT_H */
free_opts(struct option * local_opts)82 static void free_opts(struct option *local_opts)
83 {
84 if (local_opts != original_opts) {
85 free(local_opts);
86 opts = original_opts;
87 global_option_offset = 0;
88 }
89 }
90
91 /*XXX: TC_CONFIG_XT_H */
92 static struct option *
merge_options(struct option * oldopts,const struct option * newopts,unsigned int * option_offset)93 merge_options(struct option *oldopts, const struct option *newopts,
94 unsigned int *option_offset)
95 {
96 struct option *merge;
97 unsigned int num_old, num_new, i;
98
99 for (num_old = 0; oldopts[num_old].name; num_old++);
100 for (num_new = 0; newopts[num_new].name; num_new++);
101
102 *option_offset = global_option_offset + OPTION_OFFSET;
103
104 merge = malloc(sizeof(struct option) * (num_new + num_old + 1));
105 memcpy(merge, oldopts, num_old * sizeof(struct option));
106 for (i = 0; i < num_new; i++) {
107 merge[num_old + i] = newopts[i];
108 merge[num_old + i].val += *option_offset;
109 }
110 memset(merge + num_old + num_new, 0, sizeof(struct option));
111
112 return merge;
113 }
114
115
116 /*XXX: TC_CONFIG_XT_H */
117 #ifndef TRUE
118 #define TRUE 1
119 #endif
120 #ifndef FALSE
121 #define FALSE 0
122 #endif
123
124 /*XXX: TC_CONFIG_XT_H */
125 int
check_inverse(const char option[],int * invert,int * my_optind,int argc)126 check_inverse(const char option[], int *invert, int *my_optind, int argc)
127 {
128 if (option && strcmp(option, "!") == 0) {
129 if (*invert)
130 exit_error(PARAMETER_PROBLEM,
131 "Multiple `!' flags not allowed");
132 *invert = TRUE;
133 if (my_optind != NULL) {
134 ++*my_optind;
135 if (argc && *my_optind > argc)
136 exit_error(PARAMETER_PROBLEM,
137 "no argument following `!'");
138 }
139
140 return TRUE;
141 }
142 return FALSE;
143 }
144
145 /*XXX: TC_CONFIG_XT_H */
exit_error(enum exittype status,const char * msg,...)146 void exit_error(enum exittype status, const char *msg, ...)
147 {
148 va_list args;
149
150 va_start(args, msg);
151 fprintf(stderr, "%s v%s: ", pname, pversion);
152 vfprintf(stderr, msg, args);
153 va_end(args);
154 fprintf(stderr, "\n");
155 /* On error paths, make sure that we don't leak memory */
156 exit(status);
157 }
158
159 /*XXX: TC_CONFIG_XT_H */
set_revision(char * name,u_int8_t revision)160 static void set_revision(char *name, u_int8_t revision)
161 {
162 /* Old kernel sources don't have ".revision" field,
163 * but we stole a byte from name. */
164 name[IPT_FUNCTION_MAXNAMELEN - 2] = '\0';
165 name[IPT_FUNCTION_MAXNAMELEN - 1] = revision;
166 }
167
168 /*
169 * we may need to check for version mismatch
170 */
171 int
build_st(struct xtables_target * target,struct xt_entry_target * t)172 build_st(struct xtables_target *target, struct xt_entry_target *t)
173 {
174
175 size_t size =
176 XT_ALIGN(sizeof(struct xt_entry_target)) + target->size;
177
178 if (t == NULL) {
179 target->t = fw_calloc(1, size);
180 target->t->u.target_size = size;
181 strcpy(target->t->u.user.name, target->name);
182 set_revision(target->t->u.user.name, target->revision);
183
184 if (target->init != NULL)
185 target->init(target->t);
186 } else {
187 target->t = t;
188 }
189 return 0;
190
191 }
192
set_lib_dir(void)193 inline void set_lib_dir(void)
194 {
195
196 lib_dir = getenv("XTABLES_LIBDIR");
197 if (!lib_dir) {
198 lib_dir = getenv("IPTABLES_LIB_DIR");
199 if (lib_dir)
200 fprintf(stderr, "using deprecated IPTABLES_LIB_DIR\n");
201 }
202 if (lib_dir == NULL)
203 lib_dir = XT_LIB_DIR;
204
205 }
206
parse_ipt(struct action_util * a,int * argc_p,char *** argv_p,int tca_id,struct nlmsghdr * n)207 static int parse_ipt(struct action_util *a, int *argc_p,
208 char ***argv_p, int tca_id, struct nlmsghdr *n)
209 {
210 struct xtables_target *m = NULL;
211 struct ipt_entry fw;
212 struct rtattr *tail;
213 int c;
214 int rargc = *argc_p;
215 char **argv = *argv_p;
216 int argc = 0, iargc = 0;
217 char k[16];
218 int size = 0;
219 int iok = 0, ok = 0;
220 __u32 hook = 0, index = 0;
221
222 set_lib_dir();
223
224 {
225 int i;
226
227 for (i = 0; i < rargc; i++) {
228 if (NULL == argv[i] || 0 == strcmp(argv[i], "action")) {
229 break;
230 }
231 }
232 iargc = argc = i;
233 }
234
235 if (argc <= 2) {
236 fprintf(stderr, "bad arguments to ipt %d vs %d\n", argc, rargc);
237 return -1;
238 }
239
240 while (1) {
241 c = getopt_long(argc, argv, "j:", opts, NULL);
242 if (c == -1)
243 break;
244 switch (c) {
245 case 'j':
246 m = find_target(optarg, TRY_LOAD);
247 if (m != NULL) {
248
249 if (build_st(m, NULL) < 0) {
250 printf(" %s error\n", m->name);
251 return -1;
252 }
253 opts =
254 merge_options(opts, m->extra_opts,
255 &m->option_offset);
256 } else {
257 fprintf(stderr, " failed to find target %s\n\n", optarg);
258 return -1;
259 }
260 ok++;
261 break;
262
263 default:
264 memset(&fw, 0, sizeof(fw));
265 if (m) {
266 m->parse(c - m->option_offset, argv, 0,
267 &m->tflags, NULL, &m->t);
268 } else {
269 fprintf(stderr, " failed to find target %s\n\n", optarg);
270 return -1;
271
272 }
273 ok++;
274 break;
275
276 }
277 }
278
279 if (iargc > optind) {
280 if (matches(argv[optind], "index") == 0) {
281 if (get_u32(&index, argv[optind + 1], 10)) {
282 fprintf(stderr, "Illegal \"index\"\n");
283 free_opts(opts);
284 return -1;
285 }
286 iok++;
287
288 optind += 2;
289 }
290 }
291
292 if (!ok && !iok) {
293 fprintf(stderr, " ipt Parser BAD!! (%s)\n", *argv);
294 return -1;
295 }
296
297 /* check that we passed the correct parameters to the target */
298 if (m)
299 m->final_check(m->tflags);
300
301 {
302 struct tcmsg *t = NLMSG_DATA(n);
303
304 if (t->tcm_parent != TC_H_ROOT
305 && t->tcm_parent == TC_H_MAJ(TC_H_INGRESS)) {
306 hook = NF_IP_PRE_ROUTING;
307 } else {
308 hook = NF_IP_POST_ROUTING;
309 }
310 }
311
312 tail = NLMSG_TAIL(n);
313 addattr_l(n, MAX_MSG, tca_id, NULL, 0);
314 fprintf(stdout, "tablename: %s hook: %s\n ", tname, ipthooks[hook]);
315 fprintf(stdout, "\ttarget: ");
316
317 if (m)
318 m->print(NULL, m->t, 0);
319 fprintf(stdout, " index %d\n", index);
320
321 if (strlen(tname) > 16) {
322 size = 16;
323 k[15] = 0;
324 } else {
325 size = 1 + strlen(tname);
326 }
327 strncpy(k, tname, size);
328
329 addattr_l(n, MAX_MSG, TCA_IPT_TABLE, k, size);
330 addattr_l(n, MAX_MSG, TCA_IPT_HOOK, &hook, 4);
331 addattr_l(n, MAX_MSG, TCA_IPT_INDEX, &index, 4);
332 if (m)
333 addattr_l(n, MAX_MSG, TCA_IPT_TARG, m->t, m->t->u.target_size);
334 tail->rta_len = (void *) NLMSG_TAIL(n) - (void *) tail;
335
336 argc -= optind;
337 argv += optind;
338 *argc_p = rargc - iargc;
339 *argv_p = argv;
340
341 optind = 0;
342 free_opts(opts);
343 /* Clear flags if target will be used again */
344 m->tflags = 0;
345 m->used = 0;
346 /* Free allocated memory */
347 if (m->t)
348 free(m->t);
349
350
351 return 0;
352
353 }
354
355 static int
print_ipt(struct action_util * au,FILE * f,struct rtattr * arg)356 print_ipt(struct action_util *au, FILE * f, struct rtattr *arg)
357 {
358 struct rtattr *tb[TCA_IPT_MAX + 1];
359 struct xt_entry_target *t = NULL;
360
361 if (arg == NULL)
362 return -1;
363
364 set_lib_dir();
365
366 parse_rtattr_nested(tb, TCA_IPT_MAX, arg);
367
368 if (tb[TCA_IPT_TABLE] == NULL) {
369 fprintf(f, "[NULL ipt table name ] assuming mangle ");
370 } else {
371 fprintf(f, "tablename: %s ",
372 rta_getattr_str(tb[TCA_IPT_TABLE]));
373 }
374
375 if (tb[TCA_IPT_HOOK] == NULL) {
376 fprintf(f, "[NULL ipt hook name ]\n ");
377 return -1;
378 } else {
379 __u32 hook;
380
381 hook = rta_getattr_u32(tb[TCA_IPT_HOOK]);
382 fprintf(f, " hook: %s\n", ipthooks[hook]);
383 }
384
385 if (tb[TCA_IPT_TARG] == NULL) {
386 fprintf(f, "\t[NULL ipt target parameters ]\n");
387 return -1;
388 } else {
389 struct xtables_target *m = NULL;
390
391 t = RTA_DATA(tb[TCA_IPT_TARG]);
392 m = find_target(t->u.user.name, TRY_LOAD);
393 if (m != NULL) {
394 if (build_st(m, t) < 0) {
395 fprintf(stderr, " %s error\n", m->name);
396 return -1;
397 }
398
399 opts =
400 merge_options(opts, m->extra_opts,
401 &m->option_offset);
402 } else {
403 fprintf(stderr, " failed to find target %s\n\n",
404 t->u.user.name);
405 return -1;
406 }
407 fprintf(f, "\ttarget ");
408 m->print(NULL, m->t, 0);
409 if (tb[TCA_IPT_INDEX] == NULL) {
410 fprintf(f, " [NULL ipt target index ]\n");
411 } else {
412 __u32 index;
413
414 index = rta_getattr_u32(tb[TCA_IPT_INDEX]);
415 fprintf(f, "\n\tindex %u", index);
416 }
417
418 if (tb[TCA_IPT_CNT]) {
419 struct tc_cnt *c = RTA_DATA(tb[TCA_IPT_CNT]);
420
421 fprintf(f, " ref %d bind %d", c->refcnt, c->bindcnt);
422 }
423 if (show_stats) {
424 if (tb[TCA_IPT_TM]) {
425 struct tcf_t *tm = RTA_DATA(tb[TCA_IPT_TM]);
426
427 print_tm(f, tm);
428 }
429 }
430 fprintf(f, "\n");
431
432 }
433 free_opts(opts);
434
435 return 0;
436 }
437
438 struct action_util ipt_action_util = {
439 .id = "ipt",
440 .parse_aopt = parse_ipt,
441 .print_aopt = print_ipt,
442 };
443