summaryrefslogtreecommitdiffstats
path: root/tc/m_nat.c
blob: 654f9a3bd95e9136f3f5858a2ba86e1f9d37de78 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
/*
 * 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,
};