libipt_CLUSTERIP.c revision 0463ee1f28946cc49815737daa0ced0c68f39f0b 
1/* Shared library add-on to iptables to add CLUSTERIP target support.
2 * (C) 2003 by Harald Welte <laforge@gnumonks.org>
3 *
4 * Development of this code was funded by SuSE AG, http://www.suse.com/
5 */
6#include <stdio.h>
7#include <string.h>
8#include <stdlib.h>
9#include <getopt.h>
10#include <stddef.h>
11
12#if defined(__GLIBC__) && __GLIBC__ == 2
13#include <net/ethernet.h>
14#else
15#include <linux/if_ether.h>
16#endif
17
18#include <iptables.h>
19#include <linux/netfilter_ipv4/ip_tables.h>
20#include "../include/linux/netfilter_ipv4/ipt_CLUSTERIP.h"
21
22static void
23help(void)
24{
25	printf(
26"CLUSTERIP target v%s options:\n"
27"  --new			 Create a new ClusterIP\n"
28"  --hashmode <mode>		 Specify hashing mode\n"
29"					sourceip\n"
30"					sourceip-sourceport\n"
31"					sourceip-sourceport-destport\n"
32"  --clustermac <mac>		 Set clusterIP MAC address\n"
33"  --total-nodes <num>		 Set number of total nodes in cluster\n"
34"  --local-node <num>		 Set the local node number\n"
35"  --hash-init <num>		 Set init value of the Jenkins hash\n"
36"\n",
37IPTABLES_VERSION);
38}
39
40#define	PARAM_NEW	0x0001
41#define PARAM_HMODE	0x0002
42#define PARAM_MAC	0x0004
43#define PARAM_TOTALNODE	0x0008
44#define PARAM_LOCALNODE	0x0010
45#define PARAM_HASHINIT	0x0020
46
47static const struct option opts[] = {
48	{ "new", 0, NULL, '1' },
49	{ "hashmode", 1, NULL, '2' },
50	{ "clustermac", 1, NULL, '3' },
51	{ "total-nodes", 1, NULL, '4' },
52	{ "local-node", 1, NULL, '5' },
53	{ "hash-init", 1, NULL, '6' },
54	{ }
55};
56
57static void
58parse_mac(const char *mac, char *macbuf)
59{
60	unsigned int i = 0;
61
62	if (strlen(mac) != ETH_ALEN*3-1)
63		exit_error(PARAMETER_PROBLEM, "Bad mac address `%s'", mac);
64
65	for (i = 0; i < ETH_ALEN; i++) {
66		long number;
67		char *end;
68
69		number = strtol(mac + i*3, &end, 16);
70
71		if (end == mac + i*3 + 2
72		    && number >= 0
73		    && number <= 255)
74			macbuf[i] = number;
75		else
76			exit_error(PARAMETER_PROBLEM,
77				   "Bad mac address `%s'", mac);
78	}
79}
80
81static int
82parse(int c, char **argv, int invert, unsigned int *flags,
83      const void *entry,
84      struct xt_entry_target **target)
85{
86	struct ipt_clusterip_tgt_info *cipinfo
87		= (struct ipt_clusterip_tgt_info *)(*target)->data;
88
89	switch (c) {
90		unsigned int num;
91	case '1':
92		cipinfo->flags |= CLUSTERIP_FLAG_NEW;
93		if (*flags & PARAM_NEW)
94			exit_error(PARAMETER_PROBLEM, "Can only specify `--new' once\n");
95		*flags |= PARAM_NEW;
96		break;
97	case '2':
98		if (!(*flags & PARAM_NEW))
99			exit_error(PARAMETER_PROBLEM, "Can only specify hashmode combined with `--new'\n");
100		if (*flags & PARAM_HMODE)
101			exit_error(PARAMETER_PROBLEM, "Can only specify hashmode once\n");
102		if (!strcmp(optarg, "sourceip"))
103			cipinfo->hash_mode = CLUSTERIP_HASHMODE_SIP;
104		else if (!strcmp(optarg, "sourceip-sourceport"))
105			cipinfo->hash_mode = CLUSTERIP_HASHMODE_SIP_SPT;
106		else if (!strcmp(optarg, "sourceip-sourceport-destport"))
107			cipinfo->hash_mode = CLUSTERIP_HASHMODE_SIP_SPT_DPT;
108		else
109			exit_error(PARAMETER_PROBLEM, "Unknown hashmode `%s'\n",
110				   optarg);
111		*flags |= PARAM_HMODE;
112		break;
113	case '3':
114		if (!(*flags & PARAM_NEW))
115			exit_error(PARAMETER_PROBLEM, "Can only specify MAC combined with `--new'\n");
116		if (*flags & PARAM_MAC)
117			exit_error(PARAMETER_PROBLEM, "Can only specify MAC once\n");
118		parse_mac(optarg, (char *)cipinfo->clustermac);
119		if (!(cipinfo->clustermac[0] & 0x01))
120			exit_error(PARAMETER_PROBLEM, "MAC has to be a multicast ethernet address\n");
121		*flags |= PARAM_MAC;
122		break;
123	case '4':
124		if (!(*flags & PARAM_NEW))
125			exit_error(PARAMETER_PROBLEM, "Can only specify node number combined with `--new'\n");
126		if (*flags & PARAM_TOTALNODE)
127			exit_error(PARAMETER_PROBLEM, "Can only specify total node number once\n");
128		if (string_to_number(optarg, 1, CLUSTERIP_MAX_NODES, &num) < 0)
129			exit_error(PARAMETER_PROBLEM, "Unable to parse `%s'\n", optarg);
130		cipinfo->num_total_nodes = (u_int16_t)num;
131		*flags |= PARAM_TOTALNODE;
132		break;
133	case '5':
134		if (!(*flags & PARAM_NEW))
135			exit_error(PARAMETER_PROBLEM, "Can only specify node number combined with `--new'\n");
136		if (*flags & PARAM_LOCALNODE)
137			exit_error(PARAMETER_PROBLEM, "Can only specify local node number once\n");
138		if (string_to_number(optarg, 1, CLUSTERIP_MAX_NODES, &num) < 0)
139			exit_error(PARAMETER_PROBLEM, "Unable to parse `%s'\n", optarg);
140		cipinfo->num_local_nodes = 1;
141		cipinfo->local_nodes[0] = (u_int16_t)num;
142		*flags |= PARAM_LOCALNODE;
143		break;
144	case '6':
145		if (!(*flags & PARAM_NEW))
146			exit_error(PARAMETER_PROBLEM, "Can only specify hash init value combined with `--new'\n");
147		if (*flags & PARAM_HASHINIT)
148			exit_error(PARAMETER_PROBLEM, "Can specify hash init value only once\n");
149		if (string_to_number(optarg, 0, UINT_MAX, &num) < 0)
150			exit_error(PARAMETER_PROBLEM, "Unable to parse `%s'\n", optarg);
151		cipinfo->hash_initval = num;
152		*flags |= PARAM_HASHINIT;
153		break;
154	default:
155		return 0;
156	}
157
158	return 1;
159}
160
161static void
162final_check(unsigned int flags)
163{
164	if (flags == 0)
165		return;
166
167	if ((flags & (PARAM_NEW|PARAM_HMODE|PARAM_MAC|PARAM_TOTALNODE|PARAM_LOCALNODE))
168		== (PARAM_NEW|PARAM_HMODE|PARAM_MAC|PARAM_TOTALNODE|PARAM_LOCALNODE))
169		return;
170
171	exit_error(PARAMETER_PROBLEM, "CLUSTERIP target: Invalid parameter combination\n");
172}
173
174static char *hashmode2str(enum clusterip_hashmode mode)
175{
176	char *retstr;
177	switch (mode) {
178		case CLUSTERIP_HASHMODE_SIP:
179			retstr = "sourceip";
180			break;
181		case CLUSTERIP_HASHMODE_SIP_SPT:
182			retstr = "sourceip-sourceport";
183			break;
184		case CLUSTERIP_HASHMODE_SIP_SPT_DPT:
185			retstr = "sourceip-sourceport-destport";
186			break;
187		default:
188			retstr = "unknown-error";
189			break;
190	}
191	return retstr;
192}
193
194static char *mac2str(const u_int8_t mac[ETH_ALEN])
195{
196	static char buf[ETH_ALEN*3];
197	sprintf(buf, "%02X:%02X:%02X:%02X:%02X:%02X",
198		mac[0], mac[1], mac[2], mac[3], mac[4], mac[5]);
199	return buf;
200}
201
202
203/* Prints out the targinfo. */
204static void
205print(const void *ip,
206      const struct xt_entry_target *target,
207      int numeric)
208{
209	const struct ipt_clusterip_tgt_info *cipinfo =
210		(const struct ipt_clusterip_tgt_info *)target->data;
211
212	if (!cipinfo->flags & CLUSTERIP_FLAG_NEW) {
213		printf("CLUSTERIP");
214		return;
215	}
216
217	printf("CLUSTERIP hashmode=%s clustermac=%s total_nodes=%u local_node=%u hash_init=%u",
218		hashmode2str(cipinfo->hash_mode),
219		mac2str(cipinfo->clustermac),
220		cipinfo->num_total_nodes,
221		cipinfo->local_nodes[0],
222		cipinfo->hash_initval);
223}
224
225/* Saves the union ipt_targinfo in parsable form to stdout. */
226static void
227save(const void *ip, const struct xt_entry_target *target)
228{
229	const struct ipt_clusterip_tgt_info *cipinfo =
230		(const struct ipt_clusterip_tgt_info *)target->data;
231
232	/* if this is not a new entry, we don't need to save target
233	 * parameters */
234	if (!cipinfo->flags & CLUSTERIP_FLAG_NEW)
235		return;
236
237	printf("--new --hashmode %s --clustermac %s --total-nodes %d --local-node %d --hash-init %u",
238	       hashmode2str(cipinfo->hash_mode),
239	       mac2str(cipinfo->clustermac),
240	       cipinfo->num_total_nodes,
241	       cipinfo->local_nodes[0],
242	       cipinfo->hash_initval);
243}
244
245static struct iptables_target clusterip = {
246	.name		= "CLUSTERIP",
247	.version	= IPTABLES_VERSION,
248	.size		= IPT_ALIGN(sizeof(struct ipt_clusterip_tgt_info)),
249	.userspacesize	= offsetof(struct ipt_clusterip_tgt_info, config),
250 	.help		= &help,
251	.parse		= &parse,
252	.final_check	= &final_check,
253	.print		= &print,
254	.save		= &save,
255	.extra_opts	= opts
256};
257
258void _init(void)
259{
260	register_target(&clusterip);
261}
262