2 * m_ipt.c iptables based targets
3 * utilities mostly ripped from iptables <duh, its the linux way>
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.
10 * Authors: J Hadi Salim (hadi@cyberus.ca)
12 * TODO: bad bad hardcoding IPT_LIB_DIR and PROC_SYS_MODPROBE
17 #include <sys/socket.h>
18 #include <netinet/in.h>
19 #include <arpa/inet.h>
21 #include <linux/netfilter_ipv4/ip_tables.h>
24 #include <linux/tc_act/tc_ipt.h>
39 const char *pname = "tc-ipt";
40 const char *tname = "mangle";
41 const char *pversion = "0.1";
51 #define IPT_LIB_DIR "/usr/local/lib/iptables"
54 #ifndef PROC_SYS_MODPROBE
55 #define PROC_SYS_MODPROBE "/proc/sys/kernel/modprobe"
58 static const char *ipthooks[] = {
66 static struct option original_opts[] = {
71 static struct iptables_target *t_list = NULL;
72 static struct option *opts = original_opts;
73 static unsigned int global_option_offset = 0;
74 #define OPTION_OFFSET 256
78 register_target(struct iptables_target *me)
80 /* fprintf(stderr, "\nDummy register_target %s \n", me->name);
88 exit_tryhelp(int status)
90 fprintf(stderr, "Try `%s -h' or '%s --help' for more information.\n",
96 exit_error(enum exittype status, char *msg, ...)
101 fprintf(stderr, "%s v%s: ", pname, pversion);
102 vfprintf(stderr, msg, args);
104 fprintf(stderr, "\n");
105 if (status == PARAMETER_PROBLEM)
106 exit_tryhelp(status);
107 if (status == VERSION_PROBLEM)
109 "Perhaps iptables or your kernel needs to be upgraded.\n");
113 /* stolen from iptables 1.2.11
114 They should really have them as a library so i can link to them
115 Email them next time i remember
119 addr_to_dotted(const struct in_addr *addrp)
122 const unsigned char *bytep;
124 bytep = (const unsigned char *) &(addrp->s_addr);
125 sprintf(buf, "%d.%d.%d.%d", bytep[0], bytep[1], bytep[2], bytep[3]);
129 int string_to_number_ll(const char *s, unsigned long long min,
130 unsigned long long max,
131 unsigned long long *ret)
133 unsigned long long number;
136 /* Handle hex, octal, etc. */
138 number = strtoull(s, &end, 0);
139 if (*end == '\0' && end != s) {
140 /* we parsed a number, let's see if we want this */
141 if (errno != ERANGE && min <= number && (!max || number <= max)) {
149 int string_to_number_l(const char *s, unsigned long min, unsigned long max,
153 unsigned long long number;
155 result = string_to_number_ll(s, min, max, &number);
156 *ret = (unsigned long)number;
161 int string_to_number(const char *s, unsigned int min, unsigned int max,
165 unsigned long number;
167 result = string_to_number_l(s, min, max, &number);
168 *ret = (unsigned int)number;
173 static void free_opts(struct option *opts)
175 if (opts != original_opts) {
177 opts = original_opts;
178 global_option_offset = 0;
182 static struct option *
183 merge_options(struct option *oldopts, const struct option *newopts,
184 unsigned int *option_offset)
186 struct option *merge;
187 unsigned int num_old, num_new, i;
189 for (num_old = 0; oldopts[num_old].name; num_old++) ;
190 for (num_new = 0; newopts[num_new].name; num_new++) ;
192 *option_offset = global_option_offset + OPTION_OFFSET;
194 merge = malloc(sizeof (struct option) * (num_new + num_old + 1));
195 memcpy(merge, oldopts, num_old * sizeof (struct option));
196 for (i = 0; i < num_new; i++) {
197 merge[num_old + i] = newopts[i];
198 merge[num_old + i].val += *option_offset;
200 memset(merge + num_old + num_new, 0, sizeof (struct option));
206 fw_calloc(size_t count, size_t size)
210 if ((p = (void *) calloc(count, size)) == NULL) {
211 perror("iptables: calloc failed");
217 static struct iptables_target *
220 struct iptables_target *m;
221 for (m = t_list; m; m = m->next) {
222 if (strcmp(m->name, name) == 0)
229 static struct iptables_target *
230 get_target_name(char *name)
234 char *new_name, *lname;
235 struct iptables_target *m;
237 char path[sizeof (IPT_LIB_DIR) + sizeof ("/libipt_.so") + strlen(name)];
239 new_name = malloc(strlen(name) + 1);
240 lname = malloc(strlen(name) + 1);
242 memset(new_name, '\0', strlen(name) + 1);
244 exit_error(PARAMETER_PROBLEM, "get_target_name");
247 memset(lname, '\0', strlen(name) + 1);
249 exit_error(PARAMETER_PROBLEM, "get_target_name");
251 strcpy(new_name, name);
254 if (isupper(lname[0])) {
256 for (i = 0; i < strlen(name); i++) {
257 lname[i] = tolower(lname[i]);
261 if (islower(new_name[0])) {
263 for (i = 0; i < strlen(new_name); i++) {
264 new_name[i] = toupper(new_name[i]);
268 sprintf(path, IPT_LIB_DIR "/libipt_%s.so", new_name);
269 handle = dlopen(path, RTLD_LAZY);
271 sprintf(path, IPT_LIB_DIR "/libipt_%s.so", lname);
272 handle = dlopen(path, RTLD_LAZY);
274 fputs(dlerror(), stderr);
280 m = dlsym(handle, new_name);
281 if ((error = dlerror()) != NULL) {
282 m = (struct iptables_target *) dlsym(handle, lname);
283 if ((error = dlerror()) != NULL) {
284 m = find_t(new_name);
288 fputs(error, stderr);
289 fprintf(stderr, "\n");
301 struct in_addr *dotted_to_addr(const char *dotted)
303 static struct in_addr addr;
304 unsigned char *addrp;
306 unsigned int onebyte;
310 /* copy dotted string, because we need to modify it */
311 strncpy(buf, dotted, sizeof (buf) - 1);
312 addrp = (unsigned char *) &(addr.s_addr);
315 for (i = 0; i < 3; i++) {
316 if ((q = strchr(p, '.')) == NULL)
317 return (struct in_addr *) NULL;
320 if (string_to_number(p, 0, 255, &onebyte) == -1)
321 return (struct in_addr *) NULL;
323 addrp[i] = (unsigned char) onebyte;
327 /* we've checked 3 bytes, now we check the last one */
328 if (string_to_number(p, 0, 255, &onebyte) == -1)
329 return (struct in_addr *) NULL;
331 addrp[3] = (unsigned char) onebyte;
336 static void set_revision(char *name, u_int8_t revision)
338 /* Old kernel sources don't have ".revision" field,
339 * but we stole a byte from name. */
340 name[IPT_FUNCTION_MAXNAMELEN - 2] = '\0';
341 name[IPT_FUNCTION_MAXNAMELEN - 1] = revision;
345 * we may need to check for version mismatch
348 build_st(struct iptables_target *target, struct ipt_entry_target *t)
350 unsigned int nfcache = 0;
356 IPT_ALIGN(sizeof (struct ipt_entry_target)) + target->size;
359 target->t = fw_calloc(1, size);
360 target->t->u.target_size = size;
362 if (target->init != NULL)
363 target->init(target->t, &nfcache);
364 set_revision(target->t->u.user.name, target->revision);
368 strcpy(target->t->u.user.name, target->name);
375 static int parse_ipt(struct action_util *a,int *argc_p,
376 char ***argv_p, int tca_id, struct nlmsghdr *n)
378 struct iptables_target *m = NULL;
383 char **argv = *argv_p;
384 int argc = 0, iargc = 0;
389 __u32 hook = 0, index = 0;
394 for (i = 0; i < rargc; i++) {
395 if (NULL == argv[i] || 0 == strcmp(argv[i], "action")) {
403 fprintf(stderr,"bad arguements to ipt %d vs %d \n", argc, rargc);
408 c = getopt_long(argc, argv, "j:", opts, NULL);
413 m = get_target_name(optarg);
416 if (0 > build_st(m, NULL)) {
417 printf(" %s error \n", m->name);
421 merge_options(opts, m->extra_opts,
424 fprintf(stderr," failed to find target %s\n\n", optarg);
431 memset(&fw, 0, sizeof (fw));
433 m->parse(c - m->option_offset, argv, 0,
434 &m->tflags, NULL, &m->t);
436 fprintf(stderr," failed to find target %s\n\n", optarg);
446 if (iargc > optind) {
447 if (matches(argv[optind], "index") == 0) {
448 if (get_u32(&index, argv[optind + 1], 10)) {
449 fprintf(stderr, "Illegal \"index\"\n");
460 fprintf(stderr," ipt Parser BAD!! (%s)\n", *argv);
464 /* check that we passed the correct parameters to the target */
466 m->final_check(m->tflags);
469 struct tcmsg *t = NLMSG_DATA(n);
470 if (t->tcm_parent != TC_H_ROOT
471 && t->tcm_parent == TC_H_MAJ(TC_H_INGRESS)) {
472 hook = NF_IP_PRE_ROUTING;
474 hook = NF_IP_POST_ROUTING;
478 tail = NLMSG_TAIL(n);
479 addattr_l(n, MAX_MSG, tca_id, NULL, 0);
480 fprintf(stdout, "tablename: %s hook: %s\n ", tname, ipthooks[hook]);
481 fprintf(stdout, "\ttarget: ");
484 m->print(NULL, m->t, 0);
485 fprintf(stdout, " index %d\n", index);
487 if (strlen(tname) > 16) {
491 size = 1 + strlen(tname);
493 strncpy(k, tname, size);
495 addattr_l(n, MAX_MSG, TCA_IPT_TABLE, k, size);
496 addattr_l(n, MAX_MSG, TCA_IPT_HOOK, &hook, 4);
497 addattr_l(n, MAX_MSG, TCA_IPT_INDEX, &index, 4);
499 addattr_l(n, MAX_MSG, TCA_IPT_TARG, m->t, m->t->u.target_size);
500 tail->rta_len = (void *) NLMSG_TAIL(n) - (void *) tail;
504 *argc_p = rargc - iargc;
515 print_ipt(struct action_util *au,FILE * f, struct rtattr *arg)
517 struct rtattr *tb[TCA_IPT_MAX + 1];
518 struct ipt_entry_target *t = NULL;
523 parse_rtattr_nested(tb, TCA_IPT_MAX, arg);
525 if (tb[TCA_IPT_TABLE] == NULL) {
526 fprintf(f, "[NULL ipt table name ] assuming mangle ");
528 fprintf(f, "tablename: %s ",
529 (char *) RTA_DATA(tb[TCA_IPT_TABLE]));
532 if (tb[TCA_IPT_HOOK] == NULL) {
533 fprintf(f, "[NULL ipt hook name ]\n ");
537 hook = *(__u32 *) RTA_DATA(tb[TCA_IPT_HOOK]);
538 fprintf(f, " hook: %s \n", ipthooks[hook]);
541 if (tb[TCA_IPT_TARG] == NULL) {
542 fprintf(f, "\t[NULL ipt target parameters ] \n");
545 struct iptables_target *m = NULL;
546 t = RTA_DATA(tb[TCA_IPT_TARG]);
547 m = get_target_name(t->u.user.name);
549 if (0 > build_st(m, t)) {
550 fprintf(stderr, " %s error \n", m->name);
555 merge_options(opts, m->extra_opts,
558 fprintf(stderr, " failed to find target %s\n\n",
562 fprintf(f, "\ttarget ");
563 m->print(NULL, m->t, 0);
564 if (tb[TCA_IPT_INDEX] == NULL) {
565 fprintf(f, " [NULL ipt target index ]\n");
568 index = *(__u32 *) RTA_DATA(tb[TCA_IPT_INDEX]);
569 fprintf(f, " \n\tindex %d", index);
572 if (tb[TCA_IPT_CNT]) {
573 struct tc_cnt *c = RTA_DATA(tb[TCA_IPT_CNT]);;
574 fprintf(f, " ref %d bind %d", c->refcnt, c->bindcnt);
577 if (tb[TCA_IPT_TM]) {
578 struct tcf_t *tm = RTA_DATA(tb[TCA_IPT_TM]);
590 struct action_util ipt_action_util = {
592 .parse_aopt = parse_ipt,
593 .print_aopt = print_ipt,