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/*
* m_nat.c NAT module
*
* 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: Herbert Xu <herbert@gondor.apana.org.au>
*
*/
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <string.h>
#include "utils.h"
#include "tc_util.h"
#include <linux/tc_act/tc_nat.h>
static void
explain(void)
{
fprintf(stderr, "Usage: ... nat NAT\n"
"NAT := DIRECTION OLD NEW\n"
"DIRECTION := { ingress | egress }\n"
"OLD := PREFIX\n"
"NEW := ADDRESS\n");
}
static void
usage(void)
{
explain();
exit(-1);
}
static int
parse_nat_args(int *argc_p, char ***argv_p, struct tc_nat *sel)
{
int argc = *argc_p;
char **argv = *argv_p;
inet_prefix addr;
if (argc <= 0)
return -1;
if (matches(*argv, "egress") == 0)
sel->flags |= TCA_NAT_FLAG_EGRESS;
else if (matches(*argv, "ingress") != 0)
goto bad_val;
NEXT_ARG();
if (get_prefix_1(&addr, *argv, AF_INET))
goto bad_val;
sel->old_addr = addr.data[0];
sel->mask = htonl(~0u << (32 - addr.bitlen));
NEXT_ARG();
if (get_prefix_1(&addr, *argv, AF_INET))
goto bad_val;
sel->new_addr = addr.data[0];
argc--;
argv++;
*argc_p = argc;
*argv_p = argv;
return 0;
bad_val:
return -1;
}
static int
parse_nat(struct action_util *a, int *argc_p, char ***argv_p, int tca_id, struct nlmsghdr *n)
{
struct tc_nat sel = {};
int argc = *argc_p;
char **argv = *argv_p;
int ok = 0;
struct rtattr *tail;
while (argc > 0) {
if (matches(*argv, "nat") == 0) {
NEXT_ARG();
if (parse_nat_args(&argc, &argv, &sel)) {
fprintf(stderr, "Illegal nat construct (%s)\n",
*argv);
explain();
return -1;
}
ok++;
continue;
} else if (matches(*argv, "help") == 0) {
usage();
} else {
break;
}
}
if (!ok) {
explain();
return -1;
}
parse_action_control_dflt(&argc, &argv, &sel.action, false, TC_ACT_OK);
if (argc) {
if (matches(*argv, "index") == 0) {
NEXT_ARG();
if (get_u32(&sel.index, *argv, 10)) {
fprintf(stderr, "Nat: Illegal \"index\"\n");
return -1;
}
argc--;
argv++;
}
}
tail = addattr_nest(n, MAX_MSG, tca_id);
addattr_l(n, MAX_MSG, TCA_NAT_PARMS, &sel, sizeof(sel));
addattr_nest_end(n, tail);
*argc_p = argc;
*argv_p = argv;
return 0;
}
static int
print_nat(struct action_util *au, FILE * f, struct rtattr *arg)
{
struct tc_nat *sel;
struct rtattr *tb[TCA_NAT_MAX + 1];
SPRINT_BUF(buf1);
SPRINT_BUF(buf2);
int len;
print_string(PRINT_ANY, "type", " %s ", "nat");
if (arg == NULL)
return 0;
parse_rtattr_nested(tb, TCA_NAT_MAX, arg);
if (tb[TCA_NAT_PARMS] == NULL) {
fprintf(stderr, "Missing nat parameters\n");
return -1;
}
sel = RTA_DATA(tb[TCA_NAT_PARMS]);
len = ffs(sel->mask);
len = len ? 33 - len : 0;
print_string(PRINT_ANY, "direction", "%s",
sel->flags & TCA_NAT_FLAG_EGRESS ? "egress" : "ingress");
snprintf(buf2, sizeof(buf2), "%s/%d",
format_host_r(AF_INET, 4, &sel->old_addr, buf1, sizeof(buf1)),
len);
print_string(PRINT_ANY, "old_addr", " %s", buf2);
print_string(PRINT_ANY, "new_addr", " %s",
format_host_r(AF_INET, 4, &sel->new_addr, buf1, sizeof(buf1)));
print_action_control(f, " ", sel->action, "");
print_nl();
print_uint(PRINT_ANY, "index", "\t index %u", sel->index);
print_int(PRINT_ANY, "ref", " ref %d", sel->refcnt);
print_int(PRINT_ANY, "bind", " bind %d", sel->bindcnt);
if (show_stats) {
if (tb[TCA_NAT_TM]) {
struct tcf_t *tm = RTA_DATA(tb[TCA_NAT_TM]);
print_tm(f, tm);
}
}
print_nl();
return 0;
}
struct action_util nat_action_util = {
.id = "nat",
.parse_aopt = parse_nat,
.print_aopt = print_nat,
};
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