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 = 0;
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 (NULL == t) {
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 for (i = 0; i < rargc; i++) {
227 if (NULL == argv[i] || 0 == strcmp(argv[i], "action")) {
228 break;
229 }
230 }
231 iargc = argc = i;
232 }
233
234 if (argc <= 2) {
235 fprintf(stderr,"bad arguments to ipt %d vs %d \n", argc, rargc);
236 return -1;
237 }
238
239 while (1) {
240 c = getopt_long(argc, argv, "j:", opts, NULL);
241 if (c == -1)
242 break;
243 switch (c) {
244 case 'j':
245 m = find_target(optarg, TRY_LOAD);
246 if (NULL != m) {
247
248 if (0 > build_st(m, NULL)) {
249 printf(" %s error \n", m->name);
250 return -1;
251 }
252 opts =
253 merge_options(opts, m->extra_opts,
254 &m->option_offset);
255 } else {
256 fprintf(stderr," failed to find target %s\n\n", optarg);
257 return -1;
258 }
259 ok++;
260 break;
261
262 default:
263 memset(&fw, 0, sizeof (fw));
264 if (m) {
265 m->parse(c - m->option_offset, argv, 0,
266 &m->tflags, NULL, &m->t);
267 } else {
268 fprintf(stderr," failed to find target %s\n\n", optarg);
269 return -1;
270
271 }
272 ok++;
273 break;
274
275 }
276 }
277
278 if (iargc > optind) {
279 if (matches(argv[optind], "index") == 0) {
280 if (get_u32(&index, argv[optind + 1], 10)) {
281 fprintf(stderr, "Illegal \"index\"\n");
282 free_opts(opts);
283 return -1;
284 }
285 iok++;
286
287 optind += 2;
288 }
289 }
290
291 if (!ok && !iok) {
292 fprintf(stderr," ipt Parser BAD!! (%s)\n", *argv);
293 return -1;
294 }
295
296 /* check that we passed the correct parameters to the target */
297 if (m)
298 m->final_check(m->tflags);
299
300 {
301 struct tcmsg *t = NLMSG_DATA(n);
302 if (t->tcm_parent != TC_H_ROOT
303 && t->tcm_parent == TC_H_MAJ(TC_H_INGRESS)) {
304 hook = NF_IP_PRE_ROUTING;
305 } else {
306 hook = NF_IP_POST_ROUTING;
307 }
308 }
309
310 tail = NLMSG_TAIL(n);
311 addattr_l(n, MAX_MSG, tca_id, NULL, 0);
312 fprintf(stdout, "tablename: %s hook: %s\n ", tname, ipthooks[hook]);
313 fprintf(stdout, "\ttarget: ");
314
315 if (m)
316 m->print(NULL, m->t, 0);
317 fprintf(stdout, " index %d\n", index);
318
319 if (strlen(tname) > 16) {
320 size = 16;
321 k[15] = 0;
322 } else {
323 size = 1 + strlen(tname);
324 }
325 strncpy(k, tname, size);
326
327 addattr_l(n, MAX_MSG, TCA_IPT_TABLE, k, size);
328 addattr_l(n, MAX_MSG, TCA_IPT_HOOK, &hook, 4);
329 addattr_l(n, MAX_MSG, TCA_IPT_INDEX, &index, 4);
330 if (m)
331 addattr_l(n, MAX_MSG, TCA_IPT_TARG, m->t, m->t->u.target_size);
332 tail->rta_len = (void *) NLMSG_TAIL(n) - (void *) tail;
333
334 argc -= optind;
335 argv += optind;
336 *argc_p = rargc - iargc;
337 *argv_p = argv;
338
339 optind = 0;
340 free_opts(opts);
341 /* Clear flags if target will be used again */
342 m->tflags=0;
343 m->used=0;
344 /* Free allocated memory */
345 if (m->t)
346 free(m->t);
347
348
349 return 0;
350
351 }
352
353 static int
print_ipt(struct action_util * au,FILE * f,struct rtattr * arg)354 print_ipt(struct action_util *au,FILE * f, struct rtattr *arg)
355 {
356 struct rtattr *tb[TCA_IPT_MAX + 1];
357 struct xt_entry_target *t = NULL;
358
359 if (arg == NULL)
360 return -1;
361
362 set_lib_dir();
363
364 parse_rtattr_nested(tb, TCA_IPT_MAX, arg);
365
366 if (tb[TCA_IPT_TABLE] == NULL) {
367 fprintf(f, "[NULL ipt table name ] assuming mangle ");
368 } else {
369 fprintf(f, "tablename: %s ",
370 rta_getattr_str(tb[TCA_IPT_TABLE]));
371 }
372
373 if (tb[TCA_IPT_HOOK] == NULL) {
374 fprintf(f, "[NULL ipt hook name ]\n ");
375 return -1;
376 } else {
377 __u32 hook;
378 hook = rta_getattr_u32(tb[TCA_IPT_HOOK]);
379 fprintf(f, " hook: %s \n", ipthooks[hook]);
380 }
381
382 if (tb[TCA_IPT_TARG] == NULL) {
383 fprintf(f, "\t[NULL ipt target parameters ] \n");
384 return -1;
385 } else {
386 struct xtables_target *m = NULL;
387 t = RTA_DATA(tb[TCA_IPT_TARG]);
388 m = find_target(t->u.user.name, TRY_LOAD);
389 if (NULL != m) {
390 if (0 > build_st(m, t)) {
391 fprintf(stderr, " %s error \n", m->name);
392 return -1;
393 }
394
395 opts =
396 merge_options(opts, m->extra_opts,
397 &m->option_offset);
398 } else {
399 fprintf(stderr, " failed to find target %s\n\n",
400 t->u.user.name);
401 return -1;
402 }
403 fprintf(f, "\ttarget ");
404 m->print(NULL, m->t, 0);
405 if (tb[TCA_IPT_INDEX] == NULL) {
406 fprintf(f, " [NULL ipt target index ]\n");
407 } else {
408 __u32 index;
409 index = rta_getattr_u32(tb[TCA_IPT_INDEX]);
410 fprintf(f, " \n\tindex %d", index);
411 }
412
413 if (tb[TCA_IPT_CNT]) {
414 struct tc_cnt *c = RTA_DATA(tb[TCA_IPT_CNT]);;
415 fprintf(f, " ref %d bind %d", c->refcnt, c->bindcnt);
416 }
417 if (show_stats) {
418 if (tb[TCA_IPT_TM]) {
419 struct tcf_t *tm = RTA_DATA(tb[TCA_IPT_TM]);
420 print_tm(f,tm);
421 }
422 }
423 fprintf(f, " \n");
424
425 }
426 free_opts(opts);
427
428 return 0;
429 }
430
431 struct action_util ipt_action_util = {
432 .id = "ipt",
433 .parse_aopt = parse_ipt,
434 .print_aopt = print_ipt,
435 };
436