1 /* Shared library add-on to iptables to add simple non load-balancing SNAT support. */
8 #include <linux/netfilter_ipv4/ip_tables.h>
9 #include <linux/netfilter_ipv4/ip_nat_rule.h>
10 /* For 64bit kernel / 32bit userspace */
11 #include "../include/linux/netfilter_ipv4/ipt_SAME.h"
13 /* Function which prints out usage message. */
19 " --to <ipaddr>-<ipaddr>\n"
20 " Addresses to map source to.\n"
21 " May be specified more than\n"
22 " once for multiple ranges.\n"
24 " Don't use destination-ip in\n"
25 " source selection\n",
29 static struct option opts[] = {
31 { "nodst", 0, 0, '2'},
35 /* Initialize the target. */
37 init(struct ipt_entry_target *t, unsigned int *nfcache)
39 struct ipt_same_info *mr = (struct ipt_same_info *)t->data;
41 /* Set default to 0 */
48 /* Parses range of IPs */
50 parse_to(char *arg, struct ip_nat_range *range)
55 range->flags |= IP_NAT_RANGE_MAP_IPS;
56 dash = strchr(arg, '-');
61 ip = dotted_to_addr(arg);
63 exit_error(PARAMETER_PROBLEM, "Bad IP address `%s'\n",
65 range->min_ip = ip->s_addr;
68 ip = dotted_to_addr(dash+1);
70 exit_error(PARAMETER_PROBLEM, "Bad IP address `%s'\n",
73 range->max_ip = ip->s_addr;
75 if (range->min_ip > range->max_ip)
76 exit_error(PARAMETER_PROBLEM, "Bad IP range `%s-%s'\n",
80 #define IPT_SAME_OPT_TO 0x01
81 #define IPT_SAME_OPT_NODST 0x02
83 /* Function which parses command options; returns true if it
86 parse(int c, char **argv, int invert, unsigned int *flags,
87 const struct ipt_entry *entry,
88 struct ipt_entry_target **target)
90 struct ipt_same_info *mr
91 = (struct ipt_same_info *)(*target)->data;
95 if (mr->rangesize == IPT_SAME_MAX_RANGE)
96 exit_error(PARAMETER_PROBLEM,
97 "Too many ranges specified, maximum "
100 if (check_inverse(optarg, &invert, NULL, 0))
101 exit_error(PARAMETER_PROBLEM,
102 "Unexpected `!' after --to");
104 parse_to(optarg, &mr->range[mr->rangesize]);
106 *flags |= IPT_SAME_OPT_TO;
110 if (*flags & IPT_SAME_OPT_NODST)
111 exit_error(PARAMETER_PROBLEM,
112 "Can't specify --nodst twice");
114 mr->info |= IPT_SAME_NODST;
115 *flags |= IPT_SAME_OPT_NODST;
125 /* Final check; need --to. */
126 static void final_check(unsigned int flags)
128 if (!(flags & IPT_SAME_OPT_TO))
129 exit_error(PARAMETER_PROBLEM,
133 /* Prints out the targinfo. */
135 print(const struct ipt_ip *ip,
136 const struct ipt_entry_target *target,
140 struct ipt_same_info *mr
141 = (struct ipt_same_info *)target->data;
145 for (count = 0; count < mr->rangesize; count++) {
146 struct ip_nat_range *r = &mr->range[count];
149 a.s_addr = r->min_ip;
151 printf("%s", addr_to_dotted(&a));
152 a.s_addr = r->max_ip;
154 if (r->min_ip == r->max_ip)
157 printf("-%s ", addr_to_dotted(&a));
160 if (mr->info & IPT_SAME_NODST)
164 /* Saves the union ipt_targinfo in parsable form to stdout. */
166 save(const struct ipt_ip *ip, const struct ipt_entry_target *target)
169 struct ipt_same_info *mr
170 = (struct ipt_same_info *)target->data;
172 for (count = 0; count < mr->rangesize; count++) {
173 struct ip_nat_range *r = &mr->range[count];
176 a.s_addr = r->min_ip;
177 printf("--to %s", addr_to_dotted(&a));
178 a.s_addr = r->max_ip;
180 if (r->min_ip == r->max_ip)
183 printf("-%s ", addr_to_dotted(&a));
186 if (mr->info & IPT_SAME_NODST)
190 static struct iptables_target same = {
193 .version = IPTABLES_VERSION,
194 .size = IPT_ALIGN(sizeof(struct ipt_same_info)),
195 .userspacesize = IPT_ALIGN(sizeof(struct ipt_same_info)),
199 .final_check = &final_check,
207 register_target(&same);