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 #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
build_st(struct xtables_target * target,struct xt_entry_target * t)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
set_lib_dir(void)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
parse_ipt(struct action_util * a,int * argc_p,char *** argv_p,int tca_id,struct nlmsghdr * n)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
print_ipt(struct action_util * au,FILE * f,struct rtattr * arg)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