libipt_ULOG.c revision a28d495285ad7dd9f286d63958cf20d74eec6bcb 
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 struct option opts[] = {
48	{"ulog-nlgroup", 1, 0, '!'},
49	{"ulog-prefix", 1, 0, '#'},
50	{"ulog-cprange", 1, 0, 'A'},
51	{"ulog-qthreshold", 1, 0, 'B'},
52	{0}
53};
54
55/* Initialize the target. */
56static void init(struct ipt_entry_target *t, unsigned int *nfcache)
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	/* Can't cache this */
64	*nfcache |= NFC_UNKNOWN;
65}
66
67#define IPT_LOG_OPT_NLGROUP 0x01
68#define IPT_LOG_OPT_PREFIX 0x02
69#define IPT_LOG_OPT_CPRANGE 0x04
70#define IPT_LOG_OPT_QTHRESHOLD 0x08
71
72/* Function which parses command options; returns true if it
73   ate an option */
74static int parse(int c, char **argv, int invert, unsigned int *flags,
75		 const struct ipt_entry *entry,
76		 struct ipt_entry_target **target)
77{
78	struct ipt_ulog_info *loginfo =
79	    (struct ipt_ulog_info *) (*target)->data;
80	int group_d;
81
82	switch (c) {
83	case '!':
84		if (*flags & IPT_LOG_OPT_NLGROUP)
85			exit_error(PARAMETER_PROBLEM,
86				   "Can't specify --ulog-nlgroup twice");
87
88		if (check_inverse(optarg, &invert, NULL, 0))
89			exit_error(PARAMETER_PROBLEM,
90				   "Unexpected `!' after --ulog-nlgroup");
91		group_d = atoi(optarg);
92		if (group_d > 32 || group_d < 1)
93			exit_error(PARAMETER_PROBLEM,
94				   "--ulog-nlgroup has to be between 1 and 32");
95
96		loginfo->nl_group = (1 << (group_d - 1));
97
98		*flags |= IPT_LOG_OPT_NLGROUP;
99		break;
100
101	case '#':
102		if (*flags & IPT_LOG_OPT_PREFIX)
103			exit_error(PARAMETER_PROBLEM,
104				   "Can't specify --ulog-prefix twice");
105
106		if (check_inverse(optarg, &invert, NULL, 0))
107			exit_error(PARAMETER_PROBLEM,
108				   "Unexpected `!' after --ulog-prefix");
109
110		if (strlen(optarg) > sizeof(loginfo->prefix) - 1)
111			exit_error(PARAMETER_PROBLEM,
112				   "Maximum prefix length %u for --ulog-prefix",
113				   (unsigned int)sizeof(loginfo->prefix) - 1);
114
115		strcpy(loginfo->prefix, optarg);
116		*flags |= IPT_LOG_OPT_PREFIX;
117		break;
118	case 'A':
119		if (*flags & IPT_LOG_OPT_CPRANGE)
120			exit_error(PARAMETER_PROBLEM,
121				   "Can't specify --ulog-cprange twice");
122		if (atoi(optarg) < 0)
123			exit_error(PARAMETER_PROBLEM,
124				   "Negative copy range?");
125#ifdef KERNEL_64_USERSPACE_32
126		loginfo->copy_range = (unsigned long long)atoll(optarg);
127#else
128		loginfo->copy_range = atoi(optarg);
129#endif
130		*flags |= IPT_LOG_OPT_CPRANGE;
131		break;
132	case 'B':
133		if (*flags & IPT_LOG_OPT_QTHRESHOLD)
134			exit_error(PARAMETER_PROBLEM,
135				   "Can't specify --ulog-qthreshold twice");
136		if (atoi(optarg) < 1)
137			exit_error(PARAMETER_PROBLEM,
138				   "Negative or zero queue threshold ?");
139		if (atoi(optarg) > ULOG_MAX_QLEN)
140			exit_error(PARAMETER_PROBLEM,
141				   "Maximum queue length exceeded");
142#ifdef KERNEL_64_USERSPACE_32
143		loginfo->qthreshold = (unsigned long long)atoll(optarg);
144#else
145		loginfo->qthreshold = atoi(optarg);
146#endif
147		*flags |= IPT_LOG_OPT_QTHRESHOLD;
148		break;
149	}
150	return 1;
151}
152
153/* Final check; nothing. */
154static void final_check(unsigned int flags)
155{
156}
157
158/* Saves the union ipt_targinfo in parsable form to stdout. */
159static void save(const struct ipt_ip *ip,
160		 const struct ipt_entry_target *target)
161{
162	const struct ipt_ulog_info *loginfo
163	    = (const struct ipt_ulog_info *) target->data;
164
165	if (strcmp(loginfo->prefix, "") != 0)
166		printf("--ulog-prefix \"%s\" ", loginfo->prefix);
167
168	if (loginfo->nl_group != ULOG_DEFAULT_NLGROUP) {
169		printf("--ulog-nlgroup ");
170		print_groups(loginfo->nl_group);
171	}
172#ifdef KERNEL_64_USERSPACE_32
173	if (loginfo->copy_range)
174		printf("--ulog-cprange %llu ", loginfo->copy_range);
175
176	if (loginfo->qthreshold != ULOG_DEFAULT_QTHRESHOLD)
177		printf("--ulog-qthreshold %llu ", loginfo->qthreshold);
178#else
179	if (loginfo->copy_range)
180		printf("--ulog-cprange %u ", (unsigned int)loginfo->copy_range);
181
182	if (loginfo->qthreshold != ULOG_DEFAULT_QTHRESHOLD)
183		printf("--ulog-qthreshold %u ", (unsigned int)loginfo->qthreshold);
184#endif
185}
186
187/* Prints out the targinfo. */
188static void
189print(const struct ipt_ip *ip,
190      const struct ipt_entry_target *target, int numeric)
191{
192	const struct ipt_ulog_info *loginfo
193	    = (const struct ipt_ulog_info *) target->data;
194
195	printf("ULOG ");
196#ifdef KERNEL_64_USERSPACE_32
197	printf("copy_range %llu nlgroup ", loginfo->copy_range);
198#else
199	printf("copy_range %u nlgroup ", (unsigned int)loginfo->copy_range);
200#endif
201	print_groups(loginfo->nl_group);
202	if (strcmp(loginfo->prefix, "") != 0)
203		printf("prefix `%s' ", loginfo->prefix);
204#ifdef KERNEL_64_USERSPACE_32
205	printf("queue_threshold %llu ", loginfo->qthreshold);
206#else
207	printf("queue_threshold %u ", (unsigned int)loginfo->qthreshold);
208#endif
209}
210
211static
212struct iptables_target ulog = { NULL,
213	"ULOG",
214	IPTABLES_VERSION,
215	IPT_ALIGN(sizeof(struct ipt_ulog_info)),
216	IPT_ALIGN(sizeof(struct ipt_ulog_info)),
217	&help,
218	&init,
219	&parse,
220	&final_check,
221	&print,
222	&save,
223	opts
224};
225
226void _init(void)
227{
228	register_target(&ulog);
229}
230