--- /dev/null
+/* Shared library add-on to iptables to add simple non load-balancing SNAT support. */
+#include <stdio.h>
+#include <netdb.h>
+#include <string.h>
+#include <stdlib.h>
+#include <getopt.h>
+#include <iptables.h>
+#include <linux/netfilter_ipv4/ip_tables.h>
+#include <linux/netfilter/nf_nat.h>
+/* For 64bit kernel / 32bit userspace */
+#include "../include/linux/netfilter_ipv4/ipt_SAME.h"
+
+/* Function which prints out usage message. */
+static void SAME_help(void)
+{
+ printf(
+"SAME target options:\n"
+" --to <ipaddr>-<ipaddr>\n"
+" Addresses to map source to.\n"
+" May be specified more than\n"
+" once for multiple ranges.\n"
+" --nodst\n"
+" Don't use destination-ip in\n"
+" source selection\n"
+" --random\n"
+" Randomize source port\n");
+}
+
+static const struct option SAME_opts[] = {
+ { "to", 1, NULL, '1' },
+ { "nodst", 0, NULL, '2'},
+ { "random", 0, NULL, '3' },
+ { .name = NULL }
+};
+
+/* Initialize the target. */
+static void SAME_init(struct xt_entry_target *t)
+{
+ struct ipt_same_info *mr = (struct ipt_same_info *)t->data;
+
+ /* Set default to 0 */
+ mr->rangesize = 0;
+ mr->info = 0;
+ mr->ipnum = 0;
+
+}
+
+/* Parses range of IPs */
+static void
+parse_to(char *arg, struct ip_nat_range *range)
+{
+ char *dash;
+ const struct in_addr *ip;
+
+ range->flags |= IP_NAT_RANGE_MAP_IPS;
+ dash = strchr(arg, '-');
+
+ if (dash)
+ *dash = '\0';
+
+ ip = numeric_to_ipaddr(arg);
+ if (!ip)
+ exit_error(PARAMETER_PROBLEM, "Bad IP address `%s'\n",
+ arg);
+ range->min_ip = ip->s_addr;
+
+ if (dash) {
+ ip = numeric_to_ipaddr(dash+1);
+ if (!ip)
+ exit_error(PARAMETER_PROBLEM, "Bad IP address `%s'\n",
+ dash+1);
+ }
+ range->max_ip = ip->s_addr;
+ if (dash)
+ if (range->min_ip > range->max_ip)
+ exit_error(PARAMETER_PROBLEM, "Bad IP range `%s-%s'\n",
+ arg, dash+1);
+}
+
+#define IPT_SAME_OPT_TO 0x01
+#define IPT_SAME_OPT_NODST 0x02
+#define IPT_SAME_OPT_RANDOM 0x04
+
+/* Function which parses command options; returns true if it
+ ate an option */
+static int SAME_parse(int c, char **argv, int invert, unsigned int *flags,
+ const void *entry, struct xt_entry_target **target)
+{
+ struct ipt_same_info *mr
+ = (struct ipt_same_info *)(*target)->data;
+ unsigned int count;
+
+ switch (c) {
+ case '1':
+ if (mr->rangesize == IPT_SAME_MAX_RANGE)
+ exit_error(PARAMETER_PROBLEM,
+ "Too many ranges specified, maximum "
+ "is %i ranges.\n",
+ IPT_SAME_MAX_RANGE);
+ if (check_inverse(optarg, &invert, NULL, 0))
+ exit_error(PARAMETER_PROBLEM,
+ "Unexpected `!' after --to");
+
+ parse_to(optarg, &mr->range[mr->rangesize]);
+ /* WTF do we need this for? */
+ if (*flags & IPT_SAME_OPT_RANDOM)
+ mr->range[mr->rangesize].flags
+ |= IP_NAT_RANGE_PROTO_RANDOM;
+ mr->rangesize++;
+ *flags |= IPT_SAME_OPT_TO;
+ break;
+
+ case '2':
+ if (*flags & IPT_SAME_OPT_NODST)
+ exit_error(PARAMETER_PROBLEM,
+ "Can't specify --nodst twice");
+
+ mr->info |= IPT_SAME_NODST;
+ *flags |= IPT_SAME_OPT_NODST;
+ break;
+
+ case '3':
+ *flags |= IPT_SAME_OPT_RANDOM;
+ for (count=0; count < mr->rangesize; count++)
+ mr->range[count].flags |= IP_NAT_RANGE_PROTO_RANDOM;
+ break;
+
+ default:
+ return 0;
+ }
+
+ return 1;
+}
+
+/* Final check; need --to. */
+static void SAME_check(unsigned int flags)
+{
+ if (!(flags & IPT_SAME_OPT_TO))
+ exit_error(PARAMETER_PROBLEM,
+ "SAME needs --to");
+}
+
+/* Prints out the targinfo. */
+static void SAME_print(const void *ip, const struct xt_entry_target *target,
+ int numeric)
+{
+ unsigned int count;
+ struct ipt_same_info *mr
+ = (struct ipt_same_info *)target->data;
+ int random_selection = 0;
+
+ printf("same:");
+
+ for (count = 0; count < mr->rangesize; count++) {
+ struct ip_nat_range *r = &mr->range[count];
+ struct in_addr a;
+
+ a.s_addr = r->min_ip;
+
+ printf("%s", ipaddr_to_numeric(&a));
+ a.s_addr = r->max_ip;
+
+ if (r->min_ip == r->max_ip)
+ printf(" ");
+ else
+ printf("-%s ", ipaddr_to_numeric(&a));
+ if (r->flags & IP_NAT_RANGE_PROTO_RANDOM)
+ random_selection = 1;
+ }
+
+ if (mr->info & IPT_SAME_NODST)
+ printf("nodst ");
+
+ if (random_selection)
+ printf("random ");
+}
+
+/* Saves the union ipt_targinfo in parsable form to stdout. */
+static void SAME_save(const void *ip, const struct xt_entry_target *target)
+{
+ unsigned int count;
+ struct ipt_same_info *mr
+ = (struct ipt_same_info *)target->data;
+ int random_selection = 0;
+
+ for (count = 0; count < mr->rangesize; count++) {
+ struct ip_nat_range *r = &mr->range[count];
+ struct in_addr a;
+
+ a.s_addr = r->min_ip;
+ printf("--to %s", ipaddr_to_numeric(&a));
+ a.s_addr = r->max_ip;
+
+ if (r->min_ip == r->max_ip)
+ printf(" ");
+ else
+ printf("-%s ", ipaddr_to_numeric(&a));
+ if (r->flags & IP_NAT_RANGE_PROTO_RANDOM)
+ random_selection = 1;
+ }
+
+ if (mr->info & IPT_SAME_NODST)
+ printf("--nodst ");
+
+ if (random_selection)
+ printf("--random ");
+}
+
+static struct xtables_target same_tg_reg = {
+ .name = "SAME",
+ .version = XTABLES_VERSION,
+ .family = PF_INET,
+ .size = XT_ALIGN(sizeof(struct ipt_same_info)),
+ .userspacesize = XT_ALIGN(sizeof(struct ipt_same_info)),
+ .help = SAME_help,
+ .init = SAME_init,
+ .parse = SAME_parse,
+ .final_check = SAME_check,
+ .print = SAME_print,
+ .save = SAME_save,
+ .extra_opts = SAME_opts,
+};
+
+void _init(void)
+{
+ xtables_register_target(&same_tg_reg);
+}
git://git.onelab.eu / iptables.git / blobdiff