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 <limits.h>
35 #include <unistd.h>
36 #include <fcntl.h>
37 #include <sys/wait.h>
38 #ifndef XT_LIB_DIR
39 # define XT_LIB_DIR "/lib/xtables"
40 #endif
41
42 #ifndef ALIGN
43 #define ALIGN(x,a) __ALIGN_MASK(x,(typeof(x))(a)-1)
44 #define __ALIGN_MASK(x,mask) (((x)+(mask))&~(mask))
45 #endif
46
47 static const char *tname = "mangle";
48
49 char *lib_dir;
50
51 static const char *ipthooks[] = {
52 "NF_IP_PRE_ROUTING",
53 "NF_IP_LOCAL_IN",
54 "NF_IP_FORWARD",
55 "NF_IP_LOCAL_OUT",
56 "NF_IP_POST_ROUTING",
57 };
58
59 static struct option original_opts[] = {
60 {
61 .name = "jump",
62 .has_arg = 1,
63 .val = 'j'
64 },
65 {0, 0, 0, 0}
66 };
67
68 static struct xtables_globals tcipt_globals = {
69 .option_offset = 0,
70 .program_name = "tc-ipt",
71 .program_version = "0.2",
72 .orig_opts = original_opts,
73 .opts = original_opts,
74 .exit_err = NULL,
75 };
76
77 /*
78 * we may need to check for version mismatch
79 */
80 int
build_st(struct xtables_target * target,struct xt_entry_target * t)81 build_st(struct xtables_target *target, struct xt_entry_target *t)
82 {
83
84 size_t size =
85 XT_ALIGN(sizeof (struct xt_entry_target)) + target->size;
86
87 if (NULL == t) {
88 target->t = xtables_calloc(1, size);
89 target->t->u.target_size = size;
90 strcpy(target->t->u.user.name, target->name);
91 xtables_set_revision(target->t->u.user.name, target->revision);
92
93 if (target->init != NULL)
94 target->init(target->t);
95 } else {
96 target->t = t;
97 }
98 return 0;
99
100 }
101
set_lib_dir(void)102 inline void set_lib_dir(void)
103 {
104
105 lib_dir = getenv("XTABLES_LIBDIR");
106 if (!lib_dir) {
107 lib_dir = getenv("IPTABLES_LIB_DIR");
108 if (lib_dir)
109 fprintf(stderr, "using deprecated IPTABLES_LIB_DIR \n");
110 }
111 if (lib_dir == NULL)
112 lib_dir = XT_LIB_DIR;
113
114 }
115
parse_ipt(struct action_util * a,int * argc_p,char *** argv_p,int tca_id,struct nlmsghdr * n)116 static int parse_ipt(struct action_util *a,int *argc_p,
117 char ***argv_p, int tca_id, struct nlmsghdr *n)
118 {
119 struct xtables_target *m = NULL;
120 struct ipt_entry fw;
121 struct rtattr *tail;
122 int c;
123 int rargc = *argc_p;
124 char **argv = *argv_p;
125 int argc = 0, iargc = 0;
126 char k[16];
127 int res = -1;
128 int size = 0;
129 int iok = 0, ok = 0;
130 __u32 hook = 0, index = 0;
131 res = 0;
132
133 xtables_init_all(&tcipt_globals, NFPROTO_IPV4);
134 set_lib_dir();
135
136 {
137 int i;
138 for (i = 0; i < rargc; i++) {
139 if (NULL == argv[i] || 0 == strcmp(argv[i], "action")) {
140 break;
141 }
142 }
143 iargc = argc = i;
144 }
145
146 if (argc <= 2) {
147 fprintf(stderr,"bad arguements to ipt %d vs %d \n", argc, rargc);
148 return -1;
149 }
150
151 while (1) {
152 c = getopt_long(argc, argv, "j:", tcipt_globals.opts, NULL);
153 if (c == -1)
154 break;
155 switch (c) {
156 case 'j':
157 m = xtables_find_target(optarg, XTF_TRY_LOAD);
158 if (NULL != m) {
159
160 if (0 > build_st(m, NULL)) {
161 printf(" %s error \n", m->name);
162 return -1;
163 }
164 tcipt_globals.opts =
165 xtables_merge_options(tcipt_globals.opts,
166 m->extra_opts,
167 &m->option_offset);
168 } else {
169 fprintf(stderr," failed to find target %s\n\n", optarg);
170 return -1;
171 }
172 ok++;
173 break;
174
175 default:
176 memset(&fw, 0, sizeof (fw));
177 if (m) {
178 m->parse(c - m->option_offset, argv, 0,
179 &m->tflags, NULL, &m->t);
180 } else {
181 fprintf(stderr," failed to find target %s\n\n", optarg);
182 return -1;
183
184 }
185 ok++;
186 break;
187
188 }
189 }
190
191 if (iargc > optind) {
192 if (matches(argv[optind], "index") == 0) {
193 if (get_u32(&index, argv[optind + 1], 10)) {
194 fprintf(stderr, "Illegal \"index\"\n");
195 xtables_free_opts(1);
196 return -1;
197 }
198 iok++;
199
200 optind += 2;
201 }
202 }
203
204 if (!ok && !iok) {
205 fprintf(stderr," ipt Parser BAD!! (%s)\n", *argv);
206 return -1;
207 }
208
209 /* check that we passed the correct parameters to the target */
210 if (m && m->final_check)
211 m->final_check(m->tflags);
212
213 {
214 struct tcmsg *t = NLMSG_DATA(n);
215 if (t->tcm_parent != TC_H_ROOT
216 && t->tcm_parent == TC_H_MAJ(TC_H_INGRESS)) {
217 hook = NF_IP_PRE_ROUTING;
218 } else {
219 hook = NF_IP_POST_ROUTING;
220 }
221 }
222
223 tail = NLMSG_TAIL(n);
224 addattr_l(n, MAX_MSG, tca_id, NULL, 0);
225 fprintf(stdout, "tablename: %s hook: %s\n ", tname, ipthooks[hook]);
226 fprintf(stdout, "\ttarget: ");
227
228 if (m)
229 m->print(NULL, m->t, 0);
230 fprintf(stdout, " index %d\n", index);
231
232 if (strlen(tname) > 16) {
233 size = 16;
234 k[15] = 0;
235 } else {
236 size = 1 + strlen(tname);
237 }
238 strncpy(k, tname, size);
239
240 addattr_l(n, MAX_MSG, TCA_IPT_TABLE, k, size);
241 addattr_l(n, MAX_MSG, TCA_IPT_HOOK, &hook, 4);
242 addattr_l(n, MAX_MSG, TCA_IPT_INDEX, &index, 4);
243 if (m)
244 addattr_l(n, MAX_MSG, TCA_IPT_TARG, m->t, m->t->u.target_size);
245 tail->rta_len = (void *) NLMSG_TAIL(n) - (void *) tail;
246
247 argc -= optind;
248 argv += optind;
249 *argc_p = rargc - iargc;
250 *argv_p = argv;
251
252 optind = 0;
253 xtables_free_opts(1);
254 /* Clear flags if target will be used again */
255 m->tflags=0;
256 m->used=0;
257 /* Free allocated memory */
258 if (m->t)
259 free(m->t);
260
261
262 return 0;
263
264 }
265
266 static int
print_ipt(struct action_util * au,FILE * f,struct rtattr * arg)267 print_ipt(struct action_util *au,FILE * f, struct rtattr *arg)
268 {
269 struct rtattr *tb[TCA_IPT_MAX + 1];
270 struct xt_entry_target *t = NULL;
271
272 if (arg == NULL)
273 return -1;
274
275 xtables_init_all(&tcipt_globals, NFPROTO_IPV4);
276 set_lib_dir();
277
278 parse_rtattr_nested(tb, TCA_IPT_MAX, arg);
279
280 if (tb[TCA_IPT_TABLE] == NULL) {
281 fprintf(f, "[NULL ipt table name ] assuming mangle ");
282 } else {
283 fprintf(f, "tablename: %s ",
284 (char *) RTA_DATA(tb[TCA_IPT_TABLE]));
285 }
286
287 if (tb[TCA_IPT_HOOK] == NULL) {
288 fprintf(f, "[NULL ipt hook name ]\n ");
289 return -1;
290 } else {
291 __u32 hook;
292 hook = *(__u32 *) RTA_DATA(tb[TCA_IPT_HOOK]);
293 fprintf(f, " hook: %s \n", ipthooks[hook]);
294 }
295
296 if (tb[TCA_IPT_TARG] == NULL) {
297 fprintf(f, "\t[NULL ipt target parameters ] \n");
298 return -1;
299 } else {
300 struct xtables_target *m = NULL;
301 t = RTA_DATA(tb[TCA_IPT_TARG]);
302 m = xtables_find_target(t->u.user.name, XTF_TRY_LOAD);
303 if (NULL != m) {
304 if (0 > build_st(m, t)) {
305 fprintf(stderr, " %s error \n", m->name);
306 return -1;
307 }
308
309 tcipt_globals.opts =
310 xtables_merge_options(tcipt_globals.opts,
311 m->extra_opts,
312 &m->option_offset);
313 } else {
314 fprintf(stderr, " failed to find target %s\n\n",
315 t->u.user.name);
316 return -1;
317 }
318 fprintf(f, "\ttarget ");
319 m->print(NULL, m->t, 0);
320 if (tb[TCA_IPT_INDEX] == NULL) {
321 fprintf(f, " [NULL ipt target index ]\n");
322 } else {
323 __u32 index;
324 index = *(__u32 *) RTA_DATA(tb[TCA_IPT_INDEX]);
325 fprintf(f, " \n\tindex %d", index);
326 }
327
328 if (tb[TCA_IPT_CNT]) {
329 struct tc_cnt *c = RTA_DATA(tb[TCA_IPT_CNT]);;
330 fprintf(f, " ref %d bind %d", c->refcnt, c->bindcnt);
331 }
332 if (show_stats) {
333 if (tb[TCA_IPT_TM]) {
334 struct tcf_t *tm = RTA_DATA(tb[TCA_IPT_TM]);
335 print_tm(f,tm);
336 }
337 }
338 fprintf(f, " \n");
339
340 }
341 xtables_free_opts(1);
342
343 return 0;
344 }
345
346 struct action_util ipt_action_util = {
347 .id = "ipt",
348 .parse_aopt = parse_ipt,
349 .print_aopt = print_ipt,
350 };
351
352