Svenning Soerensen | b2f9cb7 | 2001-05-03 01:15:09 +0000 | [diff] [blame] | 1 | /* Shared library add-on to iptables to add static NAT support. |
| 2 | Author: Svenning Soerensen <svenning@post5.tele.dk> |
| 3 | */ |
Svenning Soerensen | b2f9cb7 | 2001-05-03 01:15:09 +0000 | [diff] [blame] | 4 | #include <stdio.h> |
| 5 | #include <netdb.h> |
| 6 | #include <string.h> |
| 7 | #include <stdlib.h> |
| 8 | #include <getopt.h> |
Jan Engelhardt | 5d9678a | 2008-11-20 10:15:35 +0100 | [diff] [blame] | 9 | #include <xtables.h> |
Jan Engelhardt | 978e27e | 2009-02-21 04:42:32 +0100 | [diff] [blame] | 10 | #include <net/netfilter/nf_nat.h> |
Svenning Soerensen | b2f9cb7 | 2001-05-03 01:15:09 +0000 | [diff] [blame] | 11 | |
| 12 | #define MODULENAME "NETMAP" |
| 13 | |
Jan Engelhardt | ef7d2e8 | 2011-05-08 21:12:46 +0200 | [diff] [blame] | 14 | enum { |
| 15 | O_TO = 0, |
| 16 | }; |
| 17 | |
| 18 | static const struct xt_option_entry NETMAP_opts[] = { |
| 19 | {.name = "to", .id = O_TO, .type = XTTYPE_HOSTMASK, |
| 20 | .flags = XTOPT_MAND}, |
| 21 | XTOPT_TABLEEND, |
Svenning Soerensen | b2f9cb7 | 2001-05-03 01:15:09 +0000 | [diff] [blame] | 22 | }; |
| 23 | |
Jan Engelhardt | 1d5b63d | 2007-10-04 16:29:00 +0000 | [diff] [blame] | 24 | static void NETMAP_help(void) |
Svenning Soerensen | b2f9cb7 | 2001-05-03 01:15:09 +0000 | [diff] [blame] | 25 | { |
Jan Engelhardt | 8b7c64d | 2008-04-15 11:48:25 +0200 | [diff] [blame] | 26 | printf(MODULENAME" target options:\n" |
Svenning Soerensen | b2f9cb7 | 2001-05-03 01:15:09 +0000 | [diff] [blame] | 27 | " --%s address[/mask]\n" |
| 28 | " Network address to map to.\n\n", |
Jan Engelhardt | 8b7c64d | 2008-04-15 11:48:25 +0200 | [diff] [blame] | 29 | NETMAP_opts[0].name); |
Svenning Soerensen | b2f9cb7 | 2001-05-03 01:15:09 +0000 | [diff] [blame] | 30 | } |
| 31 | |
Svenning Soerensen | b2f9cb7 | 2001-05-03 01:15:09 +0000 | [diff] [blame] | 32 | static int |
Jan Engelhardt | 7ac4052 | 2011-01-07 12:34:04 +0100 | [diff] [blame] | 33 | netmask2bits(uint32_t netmask) |
Svenning Soerensen | b2f9cb7 | 2001-05-03 01:15:09 +0000 | [diff] [blame] | 34 | { |
Jan Engelhardt | 7ac4052 | 2011-01-07 12:34:04 +0100 | [diff] [blame] | 35 | uint32_t bm; |
Svenning Soerensen | b2f9cb7 | 2001-05-03 01:15:09 +0000 | [diff] [blame] | 36 | int bits; |
| 37 | |
| 38 | netmask = ntohl(netmask); |
| 39 | for (bits = 0, bm = 0x80000000; netmask & bm; netmask <<= 1) |
| 40 | bits++; |
| 41 | if (netmask) |
| 42 | return -1; /* holes in netmask */ |
| 43 | return bits; |
| 44 | } |
| 45 | |
Jan Engelhardt | 1d5b63d | 2007-10-04 16:29:00 +0000 | [diff] [blame] | 46 | static void NETMAP_init(struct xt_entry_target *t) |
Svenning Soerensen | b2f9cb7 | 2001-05-03 01:15:09 +0000 | [diff] [blame] | 47 | { |
Jan Engelhardt | 978e27e | 2009-02-21 04:42:32 +0100 | [diff] [blame] | 48 | struct nf_nat_multi_range *mr = (struct nf_nat_multi_range *)t->data; |
Svenning Soerensen | b2f9cb7 | 2001-05-03 01:15:09 +0000 | [diff] [blame] | 49 | |
| 50 | /* Actually, it's 0, but it's ignored at the moment. */ |
| 51 | mr->rangesize = 1; |
Svenning Soerensen | b2f9cb7 | 2001-05-03 01:15:09 +0000 | [diff] [blame] | 52 | } |
| 53 | |
Jan Engelhardt | ef7d2e8 | 2011-05-08 21:12:46 +0200 | [diff] [blame] | 54 | static void NETMAP_parse(struct xt_option_call *cb) |
Svenning Soerensen | b2f9cb7 | 2001-05-03 01:15:09 +0000 | [diff] [blame] | 55 | { |
Jan Engelhardt | ef7d2e8 | 2011-05-08 21:12:46 +0200 | [diff] [blame] | 56 | struct nf_nat_multi_range *mr = cb->data; |
| 57 | struct nf_nat_range *range = &mr->range[0]; |
Svenning Soerensen | b2f9cb7 | 2001-05-03 01:15:09 +0000 | [diff] [blame] | 58 | |
Jan Engelhardt | ef7d2e8 | 2011-05-08 21:12:46 +0200 | [diff] [blame] | 59 | xtables_option_parse(cb); |
Svenning Soerensen | b2f9cb7 | 2001-05-03 01:15:09 +0000 | [diff] [blame] | 60 | range->flags |= IP_NAT_RANGE_MAP_IPS; |
Jan Engelhardt | ef7d2e8 | 2011-05-08 21:12:46 +0200 | [diff] [blame] | 61 | range->min_ip = cb->val.haddr.ip & cb->val.hmask.ip; |
| 62 | range->max_ip = range->min_ip | ~cb->val.hmask.ip; |
Svenning Soerensen | b2f9cb7 | 2001-05-03 01:15:09 +0000 | [diff] [blame] | 63 | } |
| 64 | |
Jan Engelhardt | 1d5b63d | 2007-10-04 16:29:00 +0000 | [diff] [blame] | 65 | static void NETMAP_print(const void *ip, const struct xt_entry_target *target, |
| 66 | int numeric) |
Svenning Soerensen | b2f9cb7 | 2001-05-03 01:15:09 +0000 | [diff] [blame] | 67 | { |
Jan Engelhardt | 69f564e | 2009-05-26 13:14:06 +0200 | [diff] [blame] | 68 | const struct nf_nat_multi_range *mr = (const void *)target->data; |
| 69 | const struct nf_nat_range *r = &mr->range[0]; |
Svenning Soerensen | b2f9cb7 | 2001-05-03 01:15:09 +0000 | [diff] [blame] | 70 | struct in_addr a; |
| 71 | int bits; |
| 72 | |
| 73 | a.s_addr = r->min_ip; |
Jan Engelhardt | e44ea7f | 2009-01-30 03:55:09 +0100 | [diff] [blame] | 74 | printf("%s", xtables_ipaddr_to_numeric(&a)); |
Svenning Soerensen | b2f9cb7 | 2001-05-03 01:15:09 +0000 | [diff] [blame] | 75 | a.s_addr = ~(r->min_ip ^ r->max_ip); |
| 76 | bits = netmask2bits(a.s_addr); |
| 77 | if (bits < 0) |
Jan Engelhardt | e44ea7f | 2009-01-30 03:55:09 +0100 | [diff] [blame] | 78 | printf("/%s", xtables_ipaddr_to_numeric(&a)); |
Svenning Soerensen | b2f9cb7 | 2001-05-03 01:15:09 +0000 | [diff] [blame] | 79 | else |
| 80 | printf("/%d", bits); |
| 81 | } |
| 82 | |
Jan Engelhardt | 1d5b63d | 2007-10-04 16:29:00 +0000 | [diff] [blame] | 83 | static void NETMAP_save(const void *ip, const struct xt_entry_target *target) |
Svenning Soerensen | b2f9cb7 | 2001-05-03 01:15:09 +0000 | [diff] [blame] | 84 | { |
Jan Engelhardt | 7386635 | 2010-12-18 02:04:59 +0100 | [diff] [blame] | 85 | printf(" --%s ", NETMAP_opts[0].name); |
Jan Engelhardt | 1d5b63d | 2007-10-04 16:29:00 +0000 | [diff] [blame] | 86 | NETMAP_print(ip, target, 0); |
Svenning Soerensen | b2f9cb7 | 2001-05-03 01:15:09 +0000 | [diff] [blame] | 87 | } |
| 88 | |
Jan Engelhardt | 8b7c64d | 2008-04-15 11:48:25 +0200 | [diff] [blame] | 89 | static struct xtables_target netmap_tg_reg = { |
Pablo Neira | 8caee8b | 2004-12-28 13:11:59 +0000 | [diff] [blame] | 90 | .name = MODULENAME, |
Jan Engelhardt | 8b7c64d | 2008-04-15 11:48:25 +0200 | [diff] [blame] | 91 | .version = XTABLES_VERSION, |
Jan Engelhardt | 03d9948 | 2008-11-18 12:27:54 +0100 | [diff] [blame] | 92 | .family = NFPROTO_IPV4, |
Jan Engelhardt | 978e27e | 2009-02-21 04:42:32 +0100 | [diff] [blame] | 93 | .size = XT_ALIGN(sizeof(struct nf_nat_multi_range)), |
| 94 | .userspacesize = XT_ALIGN(sizeof(struct nf_nat_multi_range)), |
Jan Engelhardt | 1d5b63d | 2007-10-04 16:29:00 +0000 | [diff] [blame] | 95 | .help = NETMAP_help, |
| 96 | .init = NETMAP_init, |
Jan Engelhardt | ef7d2e8 | 2011-05-08 21:12:46 +0200 | [diff] [blame] | 97 | .x6_parse = NETMAP_parse, |
Jan Engelhardt | 1d5b63d | 2007-10-04 16:29:00 +0000 | [diff] [blame] | 98 | .print = NETMAP_print, |
| 99 | .save = NETMAP_save, |
Jan Engelhardt | ef7d2e8 | 2011-05-08 21:12:46 +0200 | [diff] [blame] | 100 | .x6_options = NETMAP_opts, |
Svenning Soerensen | b2f9cb7 | 2001-05-03 01:15:09 +0000 | [diff] [blame] | 101 | }; |
| 102 | |
| 103 | void _init(void) |
| 104 | { |
Jan Engelhardt | 8b7c64d | 2008-04-15 11:48:25 +0200 | [diff] [blame] | 105 | xtables_register_target(&netmap_tg_reg); |
Svenning Soerensen | b2f9cb7 | 2001-05-03 01:15:09 +0000 | [diff] [blame] | 106 | } |