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
48static const char *pname = "tc-ipt";
49static const char *tname = "mangle";
50static const char *pversion = "0.2";
51
52static 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
60static struct option original_opts[] = {
61	{"jump", 1, 0, 'j'},
62	{0, 0, 0, 0}
63};
64
65static struct option *opts = original_opts;
66static unsigned int global_option_offset = 0;
67char *lib_dir;
68const char *program_version = XTABLES_VERSION;
69const char *program_name = "tc-ipt";
70struct 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 */
82static 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 */
92static struct option *
93merge_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 */
125int
126check_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 */
146void 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 */
160static 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*/
171int
172build_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
193inline 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
207static 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
353static int
354print_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
431struct action_util ipt_action_util = {
432        .id = "ipt",
433        .parse_aopt = parse_ipt,
434        .print_aopt = print_ipt,
435};
436