blob: d088f5ed6b5a9f02374290a214b9b0f62ab1e192 [file] [log] [blame]
/*
* m_ipt.c iptables based targets
* utilities mostly ripped from iptables <duh, its the linux way>
*
* This program is free software; you can distribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*
* Authors: J Hadi Salim (hadi@cyberus.ca)
*/
#include <syslog.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <linux/if.h>
#include <iptables.h>
#include <linux/netfilter.h>
#include <linux/netfilter_ipv4/ip_tables.h>
#include "utils.h"
#include "tc_util.h"
#include <linux/tc_act/tc_ipt.h>
#include <stdio.h>
#include <dlfcn.h>
#include <getopt.h>
#include <errno.h>
#include <string.h>
#include <netdb.h>
#include <stdlib.h>
#include <ctype.h>
#include <stdarg.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/wait.h>
static const char *pname = "tc-ipt";
static const char *tname = "mangle";
static const char *pversion = "0.1";
static const char *ipthooks[] = {
"NF_IP_PRE_ROUTING",
"NF_IP_LOCAL_IN",
"NF_IP_FORWARD",
"NF_IP_LOCAL_OUT",
"NF_IP_POST_ROUTING",
};
static struct option original_opts[] = {
{"jump", 1, 0, 'j'},
{0, 0, 0, 0}
};
static struct iptables_target *t_list;
static struct option *opts = original_opts;
static unsigned int global_option_offset;
#define OPTION_OFFSET 256
char *lib_dir;
void
register_target(struct iptables_target *me)
{
/* fprintf(stderr, "\nDummy register_target %s\n", me->name);
*/
me->next = t_list;
t_list = me;
}
void
xtables_register_target(struct iptables_target *me)
{
me->next = t_list;
t_list = me;
}
void
exit_tryhelp(int status)
{
fprintf(stderr, "Try `%s -h' or '%s --help' for more information.\n",
pname, pname);
exit(status);
}
void
exit_error(enum exittype status, char *msg, ...)
{
va_list args;
va_start(args, msg);
fprintf(stderr, "%s v%s: ", pname, pversion);
vfprintf(stderr, msg, args);
va_end(args);
fprintf(stderr, "\n");
if (status == PARAMETER_PROBLEM)
exit_tryhelp(status);
if (status == VERSION_PROBLEM)
fprintf(stderr,
"Perhaps iptables or your kernel needs to be upgraded.\n");
exit(status);
}
/* stolen from iptables 1.2.11
They should really have them as a library so i can link to them
Email them next time i remember
*/
char *
addr_to_dotted(const struct in_addr *addrp)
{
static char buf[20];
const unsigned char *bytep;
bytep = (const unsigned char *) &(addrp->s_addr);
sprintf(buf, "%d.%d.%d.%d", bytep[0], bytep[1], bytep[2], bytep[3]);
return buf;
}
int string_to_number_ll(const char *s, unsigned long long min,
unsigned long long max,
unsigned long long *ret)
{
unsigned long long number;
char *end;
/* Handle hex, octal, etc. */
errno = 0;
number = strtoull(s, &end, 0);
if (*end == '\0' && end != s) {
/* we parsed a number, let's see if we want this */
if (errno != ERANGE && min <= number && (!max || number <= max)) {
*ret = number;
return 0;
}
}
return -1;
}
int string_to_number_l(const char *s, unsigned long min, unsigned long max,
unsigned long *ret)
{
int result;
unsigned long long number;
result = string_to_number_ll(s, min, max, &number);
*ret = (unsigned long)number;
return result;
}
int string_to_number(const char *s, unsigned int min, unsigned int max,
unsigned int *ret)
{
int result;
unsigned long number;
result = string_to_number_l(s, min, max, &number);
*ret = (unsigned int)number;
return result;
}
static void free_opts(struct option *local_opts)
{
if (local_opts != original_opts) {
free(local_opts);
opts = original_opts;
global_option_offset = 0;
}
}
static struct option *
merge_options(struct option *oldopts, const struct option *newopts,
unsigned int *option_offset)
{
struct option *merge;
unsigned int num_old, num_new, i;
for (num_old = 0; oldopts[num_old].name; num_old++);
for (num_new = 0; newopts[num_new].name; num_new++);
*option_offset = global_option_offset + OPTION_OFFSET;
merge = malloc(sizeof(struct option) * (num_new + num_old + 1));
memcpy(merge, oldopts, num_old * sizeof(struct option));
for (i = 0; i < num_new; i++) {
merge[num_old + i] = newopts[i];
merge[num_old + i].val += *option_offset;
}
memset(merge + num_old + num_new, 0, sizeof(struct option));
return merge;
}
static void *
fw_calloc(size_t count, size_t size)
{
void *p;
if ((p = (void *) calloc(count, size)) == NULL) {
perror("iptables: calloc failed");
exit(1);
}
return p;
}
static struct iptables_target *
find_t(char *name)
{
struct iptables_target *m;
for (m = t_list; m; m = m->next) {
if (strcmp(m->name, name) == 0)
return m;
}
return NULL;
}
static struct iptables_target *
get_target_name(const char *name)
{
void *handle;
char *error;
char *new_name, *lname;
struct iptables_target *m;
char path[strlen(lib_dir) + sizeof("/libipt_.so") + strlen(name)];
#ifdef NO_SHARED_LIBS
return NULL;
#endif
new_name = malloc(strlen(name) + 1);
lname = malloc(strlen(name) + 1);
if (new_name)
memset(new_name, '\0', strlen(name) + 1);
else
exit_error(PARAMETER_PROBLEM, "get_target_name");
if (lname)
memset(lname, '\0', strlen(name) + 1);
else
exit_error(PARAMETER_PROBLEM, "get_target_name");
strcpy(new_name, name);
strcpy(lname, name);
if (isupper(lname[0])) {
int i;
for (i = 0; i < strlen(name); i++) {
lname[i] = tolower(lname[i]);
}
}
if (islower(new_name[0])) {
int i;
for (i = 0; i < strlen(new_name); i++) {
new_name[i] = toupper(new_name[i]);
}
}
/* try libxt_xx first */
sprintf(path, "%s/libxt_%s.so", lib_dir, new_name);
handle = dlopen(path, RTLD_LAZY);
if (!handle) {
/* try libipt_xx next */
sprintf(path, "%s/libipt_%s.so", lib_dir, new_name);
handle = dlopen(path, RTLD_LAZY);
if (!handle) {
sprintf(path, "%s/libxt_%s.so", lib_dir, lname);
handle = dlopen(path, RTLD_LAZY);
}
if (!handle) {
sprintf(path, "%s/libipt_%s.so", lib_dir, lname);
handle = dlopen(path, RTLD_LAZY);
}
/* ok, lets give up .. */
if (!handle) {
fputs(dlerror(), stderr);
printf("\n");
free(new_name);
free(lname);
return NULL;
}
}
m = dlsym(handle, new_name);
if ((error = dlerror()) != NULL) {
m = (struct iptables_target *) dlsym(handle, lname);
if ((error = dlerror()) != NULL) {
m = find_t(new_name);
if (m == NULL) {
m = find_t(lname);
if (m == NULL) {
fputs(error, stderr);
fprintf(stderr, "\n");
dlclose(handle);
free(new_name);
free(lname);
return NULL;
}
}
}
}
free(new_name);
free(lname);
return m;
}
struct in_addr *dotted_to_addr(const char *dotted)
{
static struct in_addr addr;
unsigned char *addrp;
char *p, *q;
unsigned int onebyte;
int i;
char buf[20];
/* copy dotted string, because we need to modify it */
strncpy(buf, dotted, sizeof(buf) - 1);
addrp = (unsigned char *) &(addr.s_addr);
p = buf;
for (i = 0; i < 3; i++) {
if ((q = strchr(p, '.')) == NULL)
return (struct in_addr *) NULL;
*q = '\0';
if (string_to_number(p, 0, 255, &onebyte) == -1)
return (struct in_addr *) NULL;
addrp[i] = (unsigned char) onebyte;
p = q + 1;
}
/* we've checked 3 bytes, now we check the last one */
if (string_to_number(p, 0, 255, &onebyte) == -1)
return (struct in_addr *) NULL;
addrp[3] = (unsigned char) onebyte;
return &addr;
}
static void set_revision(char *name, u_int8_t revision)
{
/* Old kernel sources don't have ".revision" field,
* but we stole a byte from name. */
name[IPT_FUNCTION_MAXNAMELEN - 2] = '\0';
name[IPT_FUNCTION_MAXNAMELEN - 1] = revision;
}
/*
* we may need to check for version mismatch
*/
int
build_st(struct iptables_target *target, struct ipt_entry_target *t)
{
unsigned int nfcache = 0;
if (target) {
size_t size;
size =
IPT_ALIGN(sizeof(struct ipt_entry_target)) + target->size;
if (t == NULL) {
target->t = fw_calloc(1, size);
target->t->u.target_size = size;
if (target->init != NULL)
target->init(target->t, &nfcache);
set_revision(target->t->u.user.name, target->revision);
} else {
target->t = t;
}
strcpy(target->t->u.user.name, target->name);
return 0;
}
return -1;
}
static int parse_ipt(struct action_util *a, int *argc_p,
char ***argv_p, int tca_id, struct nlmsghdr *n)
{
struct iptables_target *m = NULL;
struct ipt_entry fw;
struct rtattr *tail;
int c;
int rargc = *argc_p;
char **argv = *argv_p;
int argc = 0, iargc = 0;
char k[16];
int size = 0;
int iok = 0, ok = 0;
__u32 hook = 0, index = 0;
lib_dir = getenv("IPTABLES_LIB_DIR");
if (!lib_dir)
lib_dir = IPT_LIB_DIR;
{
int i;
for (i = 0; i < rargc; i++) {
if (NULL == argv[i] || 0 == strcmp(argv[i], "action")) {
break;
}
}
iargc = argc = i;
}
if (argc <= 2) {
fprintf(stderr, "bad arguments to ipt %d vs %d\n", argc, rargc);
return -1;
}
while (1) {
c = getopt_long(argc, argv, "j:", opts, NULL);
if (c == -1)
break;
switch (c) {
case 'j':
m = get_target_name(optarg);
if (m != NULL) {
if (build_st(m, NULL) < 0) {
printf(" %s error\n", m->name);
return -1;
}
opts =
merge_options(opts, m->extra_opts,
&m->option_offset);
} else {
fprintf(stderr, " failed to find target %s\n\n", optarg);
return -1;
}
ok++;
break;
default:
memset(&fw, 0, sizeof(fw));
if (m) {
m->parse(c - m->option_offset, argv, 0,
&m->tflags, NULL, &m->t);
} else {
fprintf(stderr, " failed to find target %s\n\n", optarg);
return -1;
}
ok++;
break;
}
}
if (iargc > optind) {
if (matches(argv[optind], "index") == 0) {
if (get_u32(&index, argv[optind + 1], 10)) {
fprintf(stderr, "Illegal \"index\"\n");
free_opts(opts);
return -1;
}
iok++;
optind += 2;
}
}
if (!ok && !iok) {
fprintf(stderr, " ipt Parser BAD!! (%s)\n", *argv);
return -1;
}
/* check that we passed the correct parameters to the target */
if (m)
m->final_check(m->tflags);
{
struct tcmsg *t = NLMSG_DATA(n);
if (t->tcm_parent != TC_H_ROOT
&& t->tcm_parent == TC_H_MAJ(TC_H_INGRESS)) {
hook = NF_IP_PRE_ROUTING;
} else {
hook = NF_IP_POST_ROUTING;
}
}
tail = NLMSG_TAIL(n);
addattr_l(n, MAX_MSG, tca_id, NULL, 0);
fprintf(stdout, "tablename: %s hook: %s\n ", tname, ipthooks[hook]);
fprintf(stdout, "\ttarget: ");
if (m)
m->print(NULL, m->t, 0);
fprintf(stdout, " index %d\n", index);
if (strlen(tname) > 16) {
size = 16;
k[15] = 0;
} else {
size = 1 + strlen(tname);
}
strncpy(k, tname, size);
addattr_l(n, MAX_MSG, TCA_IPT_TABLE, k, size);
addattr_l(n, MAX_MSG, TCA_IPT_HOOK, &hook, 4);
addattr_l(n, MAX_MSG, TCA_IPT_INDEX, &index, 4);
if (m)
addattr_l(n, MAX_MSG, TCA_IPT_TARG, m->t, m->t->u.target_size);
tail->rta_len = (void *) NLMSG_TAIL(n) - (void *) tail;
argc -= optind;
argv += optind;
*argc_p = rargc - iargc;
*argv_p = argv;
optind = 0;
free_opts(opts);
/* Clear flags if target will be used again */
m->tflags = 0;
m->used = 0;
/* Free allocated memory */
if (m->t)
free(m->t);
return 0;
}
static int
print_ipt(struct action_util *au, FILE * f, struct rtattr *arg)
{
struct rtattr *tb[TCA_IPT_MAX + 1];
struct ipt_entry_target *t = NULL;
if (arg == NULL)
return -1;
lib_dir = getenv("IPTABLES_LIB_DIR");
if (!lib_dir)
lib_dir = IPT_LIB_DIR;
parse_rtattr_nested(tb, TCA_IPT_MAX, arg);
if (tb[TCA_IPT_TABLE] == NULL) {
fprintf(f, "[NULL ipt table name ] assuming mangle ");
} else {
fprintf(f, "tablename: %s ",
rta_getattr_str(tb[TCA_IPT_TABLE]));
}
if (tb[TCA_IPT_HOOK] == NULL) {
fprintf(f, "[NULL ipt hook name ]\n ");
return -1;
} else {
__u32 hook;
hook = rta_getattr_u32(tb[TCA_IPT_HOOK]);
fprintf(f, " hook: %s\n", ipthooks[hook]);
}
if (tb[TCA_IPT_TARG] == NULL) {
fprintf(f, "\t[NULL ipt target parameters ]\n");
return -1;
} else {
struct iptables_target *m = NULL;
t = RTA_DATA(tb[TCA_IPT_TARG]);
m = get_target_name(t->u.user.name);
if (m != NULL) {
if (build_st(m, t) < 0) {
fprintf(stderr, " %s error\n", m->name);
return -1;
}
opts =
merge_options(opts, m->extra_opts,
&m->option_offset);
} else {
fprintf(stderr, " failed to find target %s\n\n",
t->u.user.name);
return -1;
}
fprintf(f, "\ttarget ");
m->print(NULL, m->t, 0);
if (tb[TCA_IPT_INDEX] == NULL) {
fprintf(f, " [NULL ipt target index ]\n");
} else {
__u32 index;
index = rta_getattr_u32(tb[TCA_IPT_INDEX]);
fprintf(f, "\n\tindex %d", index);
}
if (tb[TCA_IPT_CNT]) {
struct tc_cnt *c = RTA_DATA(tb[TCA_IPT_CNT]);
fprintf(f, " ref %d bind %d", c->refcnt, c->bindcnt);
}
if (show_stats) {
if (tb[TCA_IPT_TM]) {
struct tcf_t *tm = RTA_DATA(tb[TCA_IPT_TM]);
print_tm(f, tm);
}
}
fprintf(f, "\n");
}
free_opts(opts);
return 0;
}
struct action_util ipt_action_util = {
.id = "ipt",
.parse_aopt = parse_ipt,
.print_aopt = print_ipt,
};