libipt_ULOG.c revision 830132ac9c0d270bf9dcfe85c2464e3fe8c73fb9 
1/* Shared library add-on to iptables to add ULOG support.
2 *
3 * (C) 2000 by Harald Welte <laforge@gnumonks.org>
4 *
5 * multipart netlink support based on ideas by Sebastian Zander
6 * 						<zander@fokus.gmd.de>
7 *
8 * This software is released under the terms of GNU GPL
9 *
10 * libipt_ULOG.c,v 1.7 2001/01/30 11:55:02 laforge Exp
11 */
12#include <stdio.h>
13#include <netdb.h>
14#include <string.h>
15#include <stdlib.h>
16#include <syslog.h>
17#include <getopt.h>
18#include <iptables.h>
19#include <linux/netfilter_ipv4/ip_tables.h>
20/* For 64bit kernel / 32bit userspace */
21#include "../include/linux/netfilter_ipv4/ipt_ULOG.h"
22
23
24void print_groups(unsigned int gmask)
25{
26	int b;
27	unsigned int test;
28
29	for (b = 31; b >= 0; b--) {
30		test = (1 << b);
31		if (gmask & test)
32			printf("%d ", b + 1);
33	}
34}
35
36/* Function which prints out usage message. */
37static void help(void)
38{
39	printf("ULOG v%s options:\n"
40	       " --ulog-nlgroup nlgroup		NETLINK group used for logging\n"
41	       " --ulog-cprange size		Bytes of each packet to be passed\n"
42	       " --ulog-qthreshold		Threshold of in-kernel queue\n"
43	       " --ulog-prefix prefix		Prefix log messages with this prefix.\n\n",
44	       IPTABLES_VERSION);
45}
46
47static const struct option opts[] = {
48	{"ulog-nlgroup", 1, NULL, '!'},
49	{"ulog-prefix", 1, NULL, '#'},
50	{"ulog-cprange", 1, NULL, 'A'},
51	{"ulog-qthreshold", 1, NULL, 'B'},
52	{ }
53};
54
55/* Initialize the target. */
56static void init(struct xt_entry_target *t)
57{
58	struct ipt_ulog_info *loginfo = (struct ipt_ulog_info *) t->data;
59
60	loginfo->nl_group = ULOG_DEFAULT_NLGROUP;
61	loginfo->qthreshold = ULOG_DEFAULT_QTHRESHOLD;
62
63}
64
65#define IPT_LOG_OPT_NLGROUP 0x01
66#define IPT_LOG_OPT_PREFIX 0x02
67#define IPT_LOG_OPT_CPRANGE 0x04
68#define IPT_LOG_OPT_QTHRESHOLD 0x08
69
70/* Function which parses command options; returns true if it
71   ate an option */
72static int parse(int c, char **argv, int invert, unsigned int *flags,
73		 const void *entry,
74		 struct xt_entry_target **target)
75{
76	struct ipt_ulog_info *loginfo =
77	    (struct ipt_ulog_info *) (*target)->data;
78	int group_d;
79
80	switch (c) {
81	case '!':
82		if (*flags & IPT_LOG_OPT_NLGROUP)
83			exit_error(PARAMETER_PROBLEM,
84				   "Can't specify --ulog-nlgroup twice");
85
86		if (check_inverse(optarg, &invert, NULL, 0))
87			exit_error(PARAMETER_PROBLEM,
88				   "Unexpected `!' after --ulog-nlgroup");
89		group_d = atoi(optarg);
90		if (group_d > 32 || group_d < 1)
91			exit_error(PARAMETER_PROBLEM,
92				   "--ulog-nlgroup has to be between 1 and 32");
93
94		loginfo->nl_group = (1 << (group_d - 1));
95
96		*flags |= IPT_LOG_OPT_NLGROUP;
97		break;
98
99	case '#':
100		if (*flags & IPT_LOG_OPT_PREFIX)
101			exit_error(PARAMETER_PROBLEM,
102				   "Can't specify --ulog-prefix twice");
103
104		if (check_inverse(optarg, &invert, NULL, 0))
105			exit_error(PARAMETER_PROBLEM,
106				   "Unexpected `!' after --ulog-prefix");
107
108		if (strlen(optarg) > sizeof(loginfo->prefix) - 1)
109			exit_error(PARAMETER_PROBLEM,
110				   "Maximum prefix length %u for --ulog-prefix",
111				   (unsigned int)sizeof(loginfo->prefix) - 1);
112
113		if (strlen(optarg) == 0)
114			exit_error(PARAMETER_PROBLEM,
115				   "No prefix specified for --ulog-prefix");
116
117		if (strlen(optarg) != strlen(strtok(optarg, "\n")))
118			exit_error(PARAMETER_PROBLEM,
119				   "Newlines not allowed in --ulog-prefix");
120
121		strcpy(loginfo->prefix, optarg);
122		*flags |= IPT_LOG_OPT_PREFIX;
123		break;
124	case 'A':
125		if (*flags & IPT_LOG_OPT_CPRANGE)
126			exit_error(PARAMETER_PROBLEM,
127				   "Can't specify --ulog-cprange twice");
128		if (atoi(optarg) < 0)
129			exit_error(PARAMETER_PROBLEM,
130				   "Negative copy range?");
131		loginfo->copy_range = atoi(optarg);
132		*flags |= IPT_LOG_OPT_CPRANGE;
133		break;
134	case 'B':
135		if (*flags & IPT_LOG_OPT_QTHRESHOLD)
136			exit_error(PARAMETER_PROBLEM,
137				   "Can't specify --ulog-qthreshold twice");
138		if (atoi(optarg) < 1)
139			exit_error(PARAMETER_PROBLEM,
140				   "Negative or zero queue threshold ?");
141		if (atoi(optarg) > ULOG_MAX_QLEN)
142			exit_error(PARAMETER_PROBLEM,
143				   "Maximum queue length exceeded");
144		loginfo->qthreshold = atoi(optarg);
145		*flags |= IPT_LOG_OPT_QTHRESHOLD;
146		break;
147	default:
148		return 0;
149	}
150	return 1;
151}
152
153/* Saves the union ipt_targinfo in parsable form to stdout. */
154static void save(const void *ip,
155		 const struct xt_entry_target *target)
156{
157	const struct ipt_ulog_info *loginfo
158	    = (const struct ipt_ulog_info *) target->data;
159
160	if (strcmp(loginfo->prefix, "") != 0)
161		printf("--ulog-prefix \"%s\" ", loginfo->prefix);
162
163	if (loginfo->nl_group != ULOG_DEFAULT_NLGROUP) {
164		printf("--ulog-nlgroup ");
165		print_groups(loginfo->nl_group);
166	}
167	if (loginfo->copy_range)
168		printf("--ulog-cprange %u ", (unsigned int)loginfo->copy_range);
169
170	if (loginfo->qthreshold != ULOG_DEFAULT_QTHRESHOLD)
171		printf("--ulog-qthreshold %u ", (unsigned int)loginfo->qthreshold);
172}
173
174/* Prints out the targinfo. */
175static void
176print(const void *ip,
177      const struct xt_entry_target *target, int numeric)
178{
179	const struct ipt_ulog_info *loginfo
180	    = (const struct ipt_ulog_info *) target->data;
181
182	printf("ULOG ");
183	printf("copy_range %u nlgroup ", (unsigned int)loginfo->copy_range);
184	print_groups(loginfo->nl_group);
185	if (strcmp(loginfo->prefix, "") != 0)
186		printf("prefix `%s' ", loginfo->prefix);
187	printf("queue_threshold %u ", (unsigned int)loginfo->qthreshold);
188}
189
190static struct iptables_target ulog = {
191	.name		= "ULOG",
192	.version	= IPTABLES_VERSION,
193	.size		= IPT_ALIGN(sizeof(struct ipt_ulog_info)),
194	.userspacesize	= IPT_ALIGN(sizeof(struct ipt_ulog_info)),
195	.help		= &help,
196	.init		= &init,
197	.parse		= &parse,
198	.print		= &print,
199	.save		= &save,
200	.extra_opts	= opts
201};
202
203void _init(void)
204{
205	register_target(&ulog);
206}
207