m_xt.c revision 52d6a850505d70a699fc89604986c45b0cd0c54e 
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 <dlfcn.h>
29#include <getopt.h>
30#include <errno.h>
31#include <string.h>
32#include <netdb.h>
33#include <stdlib.h>
34#include <ctype.h>
35#include <stdarg.h>
36#include <limits.h>
37#include <unistd.h>
38#include <fcntl.h>
39#include <sys/wait.h>
40#ifdef TC_CONFIG_XT_H
41#include "xt-internal.h"
42#endif
43
44static const char *pname = "tc-ipt";
45static const char *tname = "mangle";
46static const char *pversion = "0.2";
47
48static const char *ipthooks[] = {
49	"NF_IP_PRE_ROUTING",
50	"NF_IP_LOCAL_IN",
51	"NF_IP_FORWARD",
52	"NF_IP_LOCAL_OUT",
53	"NF_IP_POST_ROUTING",
54};
55
56static struct option original_opts[] = {
57	{"jump", 1, 0, 'j'},
58	{0, 0, 0, 0}
59};
60
61static struct option *opts = original_opts;
62static unsigned int global_option_offset = 0;
63char *lib_dir;
64const char *program_version = XTABLES_VERSION;
65const char *program_name = "tc-ipt";
66struct afinfo afinfo = {
67	.family         = AF_INET,
68	.libprefix      = "libxt_",
69	.ipproto        = IPPROTO_IP,
70	.kmod           = "ip_tables",
71	.so_rev_target  = IPT_SO_GET_REVISION_TARGET,
72};
73
74
75#define OPTION_OFFSET 256
76
77/*XXX: TC_CONFIG_XT_H */
78static void free_opts(struct option *local_opts)
79{
80	if (local_opts != original_opts) {
81		free(local_opts);
82		opts = original_opts;
83		global_option_offset = 0;
84	}
85}
86
87/*XXX: TC_CONFIG_XT_H */
88static struct option *
89merge_options(struct option *oldopts, const struct option *newopts,
90	      unsigned int *option_offset)
91{
92	struct option *merge;
93	unsigned int num_old, num_new, i;
94
95	for (num_old = 0; oldopts[num_old].name; num_old++) ;
96	for (num_new = 0; newopts[num_new].name; num_new++) ;
97
98	*option_offset = global_option_offset + OPTION_OFFSET;
99
100	merge = malloc(sizeof (struct option) * (num_new + num_old + 1));
101	memcpy(merge, oldopts, num_old * sizeof (struct option));
102	for (i = 0; i < num_new; i++) {
103		merge[num_old + i] = newopts[i];
104		merge[num_old + i].val += *option_offset;
105	}
106	memset(merge + num_old + num_new, 0, sizeof (struct option));
107
108	return merge;
109}
110
111
112/*XXX: TC_CONFIG_XT_H */
113#ifndef TRUE
114#define TRUE 1
115#endif
116#ifndef FALSE
117#define FALSE 0
118#endif
119
120/*XXX: TC_CONFIG_XT_H */
121int
122check_inverse(const char option[], int *invert, int *my_optind, int argc)
123{
124        if (option && strcmp(option, "!") == 0) {
125                if (*invert)
126                        exit_error(PARAMETER_PROBLEM,
127                                   "Multiple `!' flags not allowed");
128                *invert = TRUE;
129                if (my_optind != NULL) {
130                        ++*my_optind;
131                        if (argc && *my_optind > argc)
132                                exit_error(PARAMETER_PROBLEM,
133                                           "no argument following `!'");
134                }
135
136                return TRUE;
137        }
138        return FALSE;
139}
140
141/*XXX: TC_CONFIG_XT_H */
142void exit_error(enum exittype status, const char *msg, ...)
143{
144        va_list args;
145
146        va_start(args, msg);
147        fprintf(stderr, "%s v%s: ", pname, pversion);
148        vfprintf(stderr, msg, args);
149        va_end(args);
150        fprintf(stderr, "\n");
151        /* On error paths, make sure that we don't leak memory */
152        exit(status);
153}
154
155/*XXX: TC_CONFIG_XT_H */
156static void set_revision(char *name, u_int8_t revision)
157{
158	/* Old kernel sources don't have ".revision" field,
159	*  but we stole a byte from name. */
160	name[IPT_FUNCTION_MAXNAMELEN - 2] = '\0';
161	name[IPT_FUNCTION_MAXNAMELEN - 1] = revision;
162}
163
164/*
165 * we may need to check for version mismatch
166*/
167int
168build_st(struct xtables_target *target, struct xt_entry_target *t)
169{
170
171	size_t size =
172		    XT_ALIGN(sizeof (struct xt_entry_target)) + target->size;
173
174	if (NULL == t) {
175		target->t = fw_calloc(1, size);
176		target->t->u.target_size = size;
177		strcpy(target->t->u.user.name, target->name);
178		set_revision(target->t->u.user.name, target->revision);
179
180		if (target->init != NULL)
181			target->init(target->t);
182	} else {
183		target->t = t;
184	}
185	return 0;
186
187}
188
189inline void set_lib_dir(void)
190{
191
192	lib_dir = getenv("XTABLES_LIBDIR");
193	if (!lib_dir) {
194		lib_dir = getenv("IPTABLES_LIB_DIR");
195		if (lib_dir)
196			fprintf(stderr, "using deprecated IPTABLES_LIB_DIR \n");
197	}
198	if (lib_dir == NULL)
199		lib_dir = XT_LIB_DIR;
200
201}
202
203static int parse_ipt(struct action_util *a,int *argc_p,
204		     char ***argv_p, int tca_id, struct nlmsghdr *n)
205{
206	struct xtables_target *m = NULL;
207	struct ipt_entry fw;
208	struct rtattr *tail;
209	int c;
210	int rargc = *argc_p;
211	char **argv = *argv_p;
212	int argc = 0, iargc = 0;
213	char k[16];
214	int res = -1;
215	int size = 0;
216	int iok = 0, ok = 0;
217	__u32 hook = 0, index = 0;
218	res = 0;
219
220	set_lib_dir();
221
222	{
223		int i;
224		for (i = 0; i < rargc; i++) {
225			if (NULL == argv[i] || 0 == strcmp(argv[i], "action")) {
226				break;
227			}
228		}
229		iargc = argc = i;
230	}
231
232	if (argc <= 2) {
233		fprintf(stderr,"bad arguements to ipt %d vs %d \n", argc, rargc);
234		return -1;
235	}
236
237	while (1) {
238		c = getopt_long(argc, argv, "j:", opts, NULL);
239		if (c == -1)
240			break;
241		switch (c) {
242		case 'j':
243			m = find_target(optarg, TRY_LOAD);
244			if (NULL != m) {
245
246				if (0 > build_st(m, NULL)) {
247					printf(" %s error \n", m->name);
248					return -1;
249				}
250				opts =
251				    merge_options(opts, m->extra_opts,
252						  &m->option_offset);
253			} else {
254				fprintf(stderr," failed to find target %s\n\n", optarg);
255				return -1;
256			}
257			ok++;
258			break;
259
260		default:
261			memset(&fw, 0, sizeof (fw));
262			if (m) {
263				m->parse(c - m->option_offset, argv, 0,
264					 &m->tflags, NULL, &m->t);
265			} else {
266				fprintf(stderr," failed to find target %s\n\n", optarg);
267				return -1;
268
269			}
270			ok++;
271			break;
272
273		}
274	}
275
276	if (iargc > optind) {
277		if (matches(argv[optind], "index") == 0) {
278			if (get_u32(&index, argv[optind + 1], 10)) {
279				fprintf(stderr, "Illegal \"index\"\n");
280				free_opts(opts);
281				return -1;
282			}
283			iok++;
284
285			optind += 2;
286		}
287	}
288
289	if (!ok && !iok) {
290		fprintf(stderr," ipt Parser BAD!! (%s)\n", *argv);
291		return -1;
292	}
293
294	/* check that we passed the correct parameters to the target */
295	if (m)
296		m->final_check(m->tflags);
297
298	{
299		struct tcmsg *t = NLMSG_DATA(n);
300		if (t->tcm_parent != TC_H_ROOT
301		    && t->tcm_parent == TC_H_MAJ(TC_H_INGRESS)) {
302			hook = NF_IP_PRE_ROUTING;
303		} else {
304			hook = NF_IP_POST_ROUTING;
305		}
306	}
307
308	tail = NLMSG_TAIL(n);
309	addattr_l(n, MAX_MSG, tca_id, NULL, 0);
310	fprintf(stdout, "tablename: %s hook: %s\n ", tname, ipthooks[hook]);
311	fprintf(stdout, "\ttarget: ");
312
313	if (m)
314		m->print(NULL, m->t, 0);
315	fprintf(stdout, " index %d\n", index);
316
317	if (strlen(tname) > 16) {
318		size = 16;
319		k[15] = 0;
320	} else {
321		size = 1 + strlen(tname);
322	}
323	strncpy(k, tname, size);
324
325	addattr_l(n, MAX_MSG, TCA_IPT_TABLE, k, size);
326	addattr_l(n, MAX_MSG, TCA_IPT_HOOK, &hook, 4);
327	addattr_l(n, MAX_MSG, TCA_IPT_INDEX, &index, 4);
328	if (m)
329		addattr_l(n, MAX_MSG, TCA_IPT_TARG, m->t, m->t->u.target_size);
330	tail->rta_len = (void *) NLMSG_TAIL(n) - (void *) tail;
331
332	argc -= optind;
333	argv += optind;
334	*argc_p = rargc - iargc;
335	*argv_p = argv;
336
337	optind = 0;
338	free_opts(opts);
339	/* Clear flags if target will be used again */
340        m->tflags=0;
341        m->used=0;
342	/* Free allocated memory */
343        if (m->t)
344            free(m->t);
345
346
347	return 0;
348
349}
350
351static int
352print_ipt(struct action_util *au,FILE * f, struct rtattr *arg)
353{
354	struct rtattr *tb[TCA_IPT_MAX + 1];
355	struct xt_entry_target *t = NULL;
356
357	if (arg == NULL)
358		return -1;
359
360	set_lib_dir();
361
362	parse_rtattr_nested(tb, TCA_IPT_MAX, arg);
363
364	if (tb[TCA_IPT_TABLE] == NULL) {
365		fprintf(f, "[NULL ipt table name ] assuming mangle ");
366	} else {
367		fprintf(f, "tablename: %s ",
368			(char *) RTA_DATA(tb[TCA_IPT_TABLE]));
369	}
370
371	if (tb[TCA_IPT_HOOK] == NULL) {
372		fprintf(f, "[NULL ipt hook name ]\n ");
373		return -1;
374	} else {
375		__u32 hook;
376		hook = *(__u32 *) RTA_DATA(tb[TCA_IPT_HOOK]);
377		fprintf(f, " hook: %s \n", ipthooks[hook]);
378	}
379
380	if (tb[TCA_IPT_TARG] == NULL) {
381		fprintf(f, "\t[NULL ipt target parameters ] \n");
382		return -1;
383	} else {
384		struct xtables_target *m = NULL;
385		t = RTA_DATA(tb[TCA_IPT_TARG]);
386		m = find_target(t->u.user.name, TRY_LOAD);
387		if (NULL != m) {
388			if (0 > build_st(m, t)) {
389				fprintf(stderr, " %s error \n", m->name);
390				return -1;
391			}
392
393			opts =
394			    merge_options(opts, m->extra_opts,
395					  &m->option_offset);
396		} else {
397			fprintf(stderr, " failed to find target %s\n\n",
398				t->u.user.name);
399			return -1;
400		}
401		fprintf(f, "\ttarget ");
402		m->print(NULL, m->t, 0);
403		if (tb[TCA_IPT_INDEX] == NULL) {
404			fprintf(f, " [NULL ipt target index ]\n");
405		} else {
406			__u32 index;
407			index = *(__u32 *) RTA_DATA(tb[TCA_IPT_INDEX]);
408			fprintf(f, " \n\tindex %d", index);
409		}
410
411		if (tb[TCA_IPT_CNT]) {
412			struct tc_cnt *c  = RTA_DATA(tb[TCA_IPT_CNT]);;
413			fprintf(f, " ref %d bind %d", c->refcnt, c->bindcnt);
414		}
415		if (show_stats) {
416			if (tb[TCA_IPT_TM]) {
417				struct tcf_t *tm = RTA_DATA(tb[TCA_IPT_TM]);
418				print_tm(f,tm);
419			}
420		}
421		fprintf(f, " \n");
422
423	}
424	free_opts(opts);
425
426	return 0;
427}
428
429struct action_util ipt_action_util = {
430        .id = "ipt",
431        .parse_aopt = parse_ipt,
432        .print_aopt = print_ipt,
433};
434
435