Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* Kernel module to match Hop-by-Hop and Destination parameters. */ |
| 2 | |
| 3 | /* (C) 2001-2002 Andras Kis-Szabo <kisza@sch.bme.hu> |
| 4 | * |
| 5 | * This program is free software; you can redistribute it and/or modify |
| 6 | * it under the terms of the GNU General Public License version 2 as |
| 7 | * published by the Free Software Foundation. |
| 8 | */ |
Jan Engelhardt | ff67e4e | 2010-03-19 21:08:16 +0100 | [diff] [blame] | 9 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 10 | #include <linux/module.h> |
| 11 | #include <linux/skbuff.h> |
| 12 | #include <linux/ipv6.h> |
| 13 | #include <linux/types.h> |
| 14 | #include <net/checksum.h> |
| 15 | #include <net/ipv6.h> |
| 16 | |
| 17 | #include <asm/byteorder.h> |
| 18 | |
Jan Engelhardt | 6709dbb | 2007-02-07 15:11:19 -0800 | [diff] [blame] | 19 | #include <linux/netfilter/x_tables.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 20 | #include <linux/netfilter_ipv6/ip6_tables.h> |
| 21 | #include <linux/netfilter_ipv6/ip6t_opts.h> |
| 22 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 23 | MODULE_LICENSE("GPL"); |
Jan Engelhardt | 2ae15b6 | 2008-01-14 23:42:28 -0800 | [diff] [blame] | 24 | MODULE_DESCRIPTION("Xtables: IPv6 Hop-By-Hop and Destination Header match"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 25 | MODULE_AUTHOR("Andras Kis-Szabo <kisza@sch.bme.hu>"); |
Patrick McHardy | 5fa2a76 | 2006-08-22 00:43:55 -0700 | [diff] [blame] | 26 | MODULE_ALIAS("ip6t_dst"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 27 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 28 | /* |
Yasuyuki Kozakai | f0daaa6 | 2006-01-17 02:39:39 -0800 | [diff] [blame] | 29 | * (Type & 0xC0) >> 6 |
| 30 | * 0 -> ignorable |
| 31 | * 1 -> must drop the packet |
| 32 | * 2 -> send ICMP PARM PROB regardless and drop packet |
| 33 | * 3 -> Send ICMP if not a multicast address and drop packet |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 34 | * (Type & 0x20) >> 5 |
Yasuyuki Kozakai | f0daaa6 | 2006-01-17 02:39:39 -0800 | [diff] [blame] | 35 | * 0 -> invariant |
| 36 | * 1 -> can change the routing |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 37 | * (Type & 0x1F) Type |
Yasuyuki Kozakai | f0daaa6 | 2006-01-17 02:39:39 -0800 | [diff] [blame] | 38 | * 0 -> Pad1 (only 1 byte!) |
| 39 | * 1 -> PadN LENGTH info (total length = length + 2) |
| 40 | * C0 | 2 -> JUMBO 4 x x x x ( xxxx > 64k ) |
| 41 | * 5 -> RTALERT 2 x x |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 42 | */ |
| 43 | |
Jan Engelhardt | 4f948db | 2010-03-18 11:03:51 +0100 | [diff] [blame] | 44 | static struct xt_match hbh_mt6_reg[] __read_mostly; |
| 45 | |
Jan Engelhardt | 1d93a9c | 2007-07-07 22:15:35 -0700 | [diff] [blame] | 46 | static bool |
Jan Engelhardt | 62fc805 | 2009-07-07 20:42:08 +0200 | [diff] [blame] | 47 | hbh_mt6(const struct sk_buff *skb, struct xt_action_param *par) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 48 | { |
Jan Engelhardt | a47362a | 2007-07-07 22:16:55 -0700 | [diff] [blame] | 49 | struct ipv6_opt_hdr _optsh; |
| 50 | const struct ipv6_opt_hdr *oh; |
Jan Engelhardt | f7108a2 | 2008-10-08 11:35:18 +0200 | [diff] [blame] | 51 | const struct ip6t_opts *optinfo = par->matchinfo; |
Yasuyuki Kozakai | f0daaa6 | 2006-01-17 02:39:39 -0800 | [diff] [blame] | 52 | unsigned int temp; |
Hans Schillstrom | 84018f5 | 2012-04-23 03:35:26 +0000 | [diff] [blame] | 53 | unsigned int ptr = 0; |
Yasuyuki Kozakai | f0daaa6 | 2006-01-17 02:39:39 -0800 | [diff] [blame] | 54 | unsigned int hdrlen = 0; |
Jan Engelhardt | 1d93a9c | 2007-07-07 22:15:35 -0700 | [diff] [blame] | 55 | bool ret = false; |
Jan Engelhardt | a47362a | 2007-07-07 22:16:55 -0700 | [diff] [blame] | 56 | u8 _opttype; |
| 57 | u8 _optlen; |
| 58 | const u_int8_t *tp = NULL; |
| 59 | const u_int8_t *lp = NULL; |
Yasuyuki Kozakai | f0daaa6 | 2006-01-17 02:39:39 -0800 | [diff] [blame] | 60 | unsigned int optlen; |
Patrick McHardy | 6d38163 | 2006-10-24 16:15:10 -0700 | [diff] [blame] | 61 | int err; |
Yasuyuki Kozakai | f0daaa6 | 2006-01-17 02:39:39 -0800 | [diff] [blame] | 62 | |
Jan Engelhardt | 4f948db | 2010-03-18 11:03:51 +0100 | [diff] [blame] | 63 | err = ipv6_find_hdr(skb, &ptr, |
| 64 | (par->match == &hbh_mt6_reg[0]) ? |
Hans Schillstrom | 84018f5 | 2012-04-23 03:35:26 +0000 | [diff] [blame] | 65 | NEXTHDR_HOP : NEXTHDR_DEST, NULL, NULL); |
Patrick McHardy | 6d38163 | 2006-10-24 16:15:10 -0700 | [diff] [blame] | 66 | if (err < 0) { |
| 67 | if (err != -ENOENT) |
Jan Engelhardt | b4ba261 | 2009-07-07 20:54:30 +0200 | [diff] [blame] | 68 | par->hotdrop = true; |
Jan Engelhardt | 1d93a9c | 2007-07-07 22:15:35 -0700 | [diff] [blame] | 69 | return false; |
Patrick McHardy | 6d38163 | 2006-10-24 16:15:10 -0700 | [diff] [blame] | 70 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 71 | |
Yasuyuki Kozakai | f0daaa6 | 2006-01-17 02:39:39 -0800 | [diff] [blame] | 72 | oh = skb_header_pointer(skb, ptr, sizeof(_optsh), &_optsh); |
| 73 | if (oh == NULL) { |
Jan Engelhardt | b4ba261 | 2009-07-07 20:54:30 +0200 | [diff] [blame] | 74 | par->hotdrop = true; |
Jan Engelhardt | 1d93a9c | 2007-07-07 22:15:35 -0700 | [diff] [blame] | 75 | return false; |
Yasuyuki Kozakai | f0daaa6 | 2006-01-17 02:39:39 -0800 | [diff] [blame] | 76 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 77 | |
Yasuyuki Kozakai | f0daaa6 | 2006-01-17 02:39:39 -0800 | [diff] [blame] | 78 | hdrlen = ipv6_optlen(oh); |
| 79 | if (skb->len - ptr < hdrlen) { |
| 80 | /* Packet smaller than it's length field */ |
Jan Engelhardt | 1d93a9c | 2007-07-07 22:15:35 -0700 | [diff] [blame] | 81 | return false; |
Yasuyuki Kozakai | f0daaa6 | 2006-01-17 02:39:39 -0800 | [diff] [blame] | 82 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 83 | |
Patrick McHardy | 0d53778 | 2007-07-07 22:39:38 -0700 | [diff] [blame] | 84 | pr_debug("IPv6 OPTS LEN %u %u ", hdrlen, oh->hdrlen); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 85 | |
Patrick McHardy | 0d53778 | 2007-07-07 22:39:38 -0700 | [diff] [blame] | 86 | pr_debug("len %02X %04X %02X ", |
| 87 | optinfo->hdrlen, hdrlen, |
| 88 | (!(optinfo->flags & IP6T_OPTS_LEN) || |
| 89 | ((optinfo->hdrlen == hdrlen) ^ |
| 90 | !!(optinfo->invflags & IP6T_OPTS_INV_LEN)))); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 91 | |
Yasuyuki Kozakai | f0daaa6 | 2006-01-17 02:39:39 -0800 | [diff] [blame] | 92 | ret = (oh != NULL) && |
| 93 | (!(optinfo->flags & IP6T_OPTS_LEN) || |
| 94 | ((optinfo->hdrlen == hdrlen) ^ |
| 95 | !!(optinfo->invflags & IP6T_OPTS_INV_LEN))); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 96 | |
Yasuyuki Kozakai | f0daaa6 | 2006-01-17 02:39:39 -0800 | [diff] [blame] | 97 | ptr += 2; |
| 98 | hdrlen -= 2; |
| 99 | if (!(optinfo->flags & IP6T_OPTS_OPTS)) { |
| 100 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 101 | } else { |
Patrick McHardy | 0d53778 | 2007-07-07 22:39:38 -0700 | [diff] [blame] | 102 | pr_debug("Strict "); |
| 103 | pr_debug("#%d ", optinfo->optsnr); |
Yasuyuki Kozakai | f0daaa6 | 2006-01-17 02:39:39 -0800 | [diff] [blame] | 104 | for (temp = 0; temp < optinfo->optsnr; temp++) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 105 | /* type field exists ? */ |
| 106 | if (hdrlen < 1) |
| 107 | break; |
| 108 | tp = skb_header_pointer(skb, ptr, sizeof(_opttype), |
| 109 | &_opttype); |
| 110 | if (tp == NULL) |
| 111 | break; |
| 112 | |
| 113 | /* Type check */ |
Yasuyuki Kozakai | f0daaa6 | 2006-01-17 02:39:39 -0800 | [diff] [blame] | 114 | if (*tp != (optinfo->opts[temp] & 0xFF00) >> 8) { |
Patrick McHardy | 0d53778 | 2007-07-07 22:39:38 -0700 | [diff] [blame] | 115 | pr_debug("Tbad %02X %02X\n", *tp, |
| 116 | (optinfo->opts[temp] & 0xFF00) >> 8); |
Jan Engelhardt | 1d93a9c | 2007-07-07 22:15:35 -0700 | [diff] [blame] | 117 | return false; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 118 | } else { |
Patrick McHardy | 0d53778 | 2007-07-07 22:39:38 -0700 | [diff] [blame] | 119 | pr_debug("Tok "); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 120 | } |
| 121 | /* Length check */ |
| 122 | if (*tp) { |
| 123 | u16 spec_len; |
| 124 | |
| 125 | /* length field exists ? */ |
| 126 | if (hdrlen < 2) |
| 127 | break; |
| 128 | lp = skb_header_pointer(skb, ptr + 1, |
| 129 | sizeof(_optlen), |
| 130 | &_optlen); |
| 131 | if (lp == NULL) |
| 132 | break; |
| 133 | spec_len = optinfo->opts[temp] & 0x00FF; |
| 134 | |
| 135 | if (spec_len != 0x00FF && spec_len != *lp) { |
Patrick McHardy | 0d53778 | 2007-07-07 22:39:38 -0700 | [diff] [blame] | 136 | pr_debug("Lbad %02X %04X\n", *lp, |
| 137 | spec_len); |
Jan Engelhardt | 1d93a9c | 2007-07-07 22:15:35 -0700 | [diff] [blame] | 138 | return false; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 139 | } |
Patrick McHardy | 0d53778 | 2007-07-07 22:39:38 -0700 | [diff] [blame] | 140 | pr_debug("Lok "); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 141 | optlen = *lp + 2; |
| 142 | } else { |
Patrick McHardy | 0d53778 | 2007-07-07 22:39:38 -0700 | [diff] [blame] | 143 | pr_debug("Pad1\n"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 144 | optlen = 1; |
| 145 | } |
| 146 | |
| 147 | /* Step to the next */ |
Frans Pop | b138338 | 2010-03-24 07:57:28 +0000 | [diff] [blame] | 148 | pr_debug("len%04X\n", optlen); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 149 | |
| 150 | if ((ptr > skb->len - optlen || hdrlen < optlen) && |
Jan Engelhardt | 7c4e36b | 2007-07-07 22:19:08 -0700 | [diff] [blame] | 151 | temp < optinfo->optsnr - 1) { |
Frans Pop | b138338 | 2010-03-24 07:57:28 +0000 | [diff] [blame] | 152 | pr_debug("new pointer is too large!\n"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 153 | break; |
| 154 | } |
| 155 | ptr += optlen; |
| 156 | hdrlen -= optlen; |
| 157 | } |
| 158 | if (temp == optinfo->optsnr) |
| 159 | return ret; |
Yasuyuki Kozakai | f0daaa6 | 2006-01-17 02:39:39 -0800 | [diff] [blame] | 160 | else |
Jan Engelhardt | 1d93a9c | 2007-07-07 22:15:35 -0700 | [diff] [blame] | 161 | return false; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 162 | } |
| 163 | |
Jan Engelhardt | 1d93a9c | 2007-07-07 22:15:35 -0700 | [diff] [blame] | 164 | return false; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 165 | } |
| 166 | |
Jan Engelhardt | b0f3845 | 2010-03-19 17:16:42 +0100 | [diff] [blame] | 167 | static int hbh_mt6_check(const struct xt_mtchk_param *par) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 168 | { |
Jan Engelhardt | 9b4fce7 | 2008-10-08 11:35:18 +0200 | [diff] [blame] | 169 | const struct ip6t_opts *optsinfo = par->matchinfo; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 170 | |
Yasuyuki Kozakai | f0daaa6 | 2006-01-17 02:39:39 -0800 | [diff] [blame] | 171 | if (optsinfo->invflags & ~IP6T_OPTS_INV_MASK) { |
Jan Engelhardt | ff67e4e | 2010-03-19 21:08:16 +0100 | [diff] [blame] | 172 | pr_debug("unknown flags %X\n", optsinfo->invflags); |
Jan Engelhardt | bd414ee | 2010-03-23 16:35:56 +0100 | [diff] [blame] | 173 | return -EINVAL; |
Yasuyuki Kozakai | f0daaa6 | 2006-01-17 02:39:39 -0800 | [diff] [blame] | 174 | } |
Yasuyuki Kozakai | 8ca31ce | 2008-09-24 15:53:39 -0700 | [diff] [blame] | 175 | |
| 176 | if (optsinfo->flags & IP6T_OPTS_NSTRICT) { |
Jan Engelhardt | ff67e4e | 2010-03-19 21:08:16 +0100 | [diff] [blame] | 177 | pr_debug("Not strict - not implemented"); |
Jan Engelhardt | bd414ee | 2010-03-23 16:35:56 +0100 | [diff] [blame] | 178 | return -EINVAL; |
Yasuyuki Kozakai | 8ca31ce | 2008-09-24 15:53:39 -0700 | [diff] [blame] | 179 | } |
| 180 | |
Jan Engelhardt | bd414ee | 2010-03-23 16:35:56 +0100 | [diff] [blame] | 181 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 182 | } |
| 183 | |
Jan Engelhardt | d3c5ee6 | 2007-12-04 23:24:03 -0800 | [diff] [blame] | 184 | static struct xt_match hbh_mt6_reg[] __read_mostly = { |
Patrick McHardy | 5fa2a76 | 2006-08-22 00:43:55 -0700 | [diff] [blame] | 185 | { |
Jan Engelhardt | 4f948db | 2010-03-18 11:03:51 +0100 | [diff] [blame] | 186 | /* Note, hbh_mt6 relies on the order of hbh_mt6_reg */ |
Patrick McHardy | 5fa2a76 | 2006-08-22 00:43:55 -0700 | [diff] [blame] | 187 | .name = "hbh", |
Jan Engelhardt | ee999d8 | 2008-10-08 11:35:01 +0200 | [diff] [blame] | 188 | .family = NFPROTO_IPV6, |
Jan Engelhardt | d3c5ee6 | 2007-12-04 23:24:03 -0800 | [diff] [blame] | 189 | .match = hbh_mt6, |
Patrick McHardy | 5fa2a76 | 2006-08-22 00:43:55 -0700 | [diff] [blame] | 190 | .matchsize = sizeof(struct ip6t_opts), |
Jan Engelhardt | d3c5ee6 | 2007-12-04 23:24:03 -0800 | [diff] [blame] | 191 | .checkentry = hbh_mt6_check, |
Patrick McHardy | 5fa2a76 | 2006-08-22 00:43:55 -0700 | [diff] [blame] | 192 | .me = THIS_MODULE, |
Patrick McHardy | 5fa2a76 | 2006-08-22 00:43:55 -0700 | [diff] [blame] | 193 | }, |
| 194 | { |
| 195 | .name = "dst", |
Jan Engelhardt | ee999d8 | 2008-10-08 11:35:01 +0200 | [diff] [blame] | 196 | .family = NFPROTO_IPV6, |
Jan Engelhardt | d3c5ee6 | 2007-12-04 23:24:03 -0800 | [diff] [blame] | 197 | .match = hbh_mt6, |
Patrick McHardy | 5fa2a76 | 2006-08-22 00:43:55 -0700 | [diff] [blame] | 198 | .matchsize = sizeof(struct ip6t_opts), |
Jan Engelhardt | d3c5ee6 | 2007-12-04 23:24:03 -0800 | [diff] [blame] | 199 | .checkentry = hbh_mt6_check, |
Patrick McHardy | 5fa2a76 | 2006-08-22 00:43:55 -0700 | [diff] [blame] | 200 | .me = THIS_MODULE, |
Patrick McHardy | 5fa2a76 | 2006-08-22 00:43:55 -0700 | [diff] [blame] | 201 | }, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 202 | }; |
| 203 | |
Jan Engelhardt | d3c5ee6 | 2007-12-04 23:24:03 -0800 | [diff] [blame] | 204 | static int __init hbh_mt6_init(void) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 205 | { |
Jan Engelhardt | d3c5ee6 | 2007-12-04 23:24:03 -0800 | [diff] [blame] | 206 | return xt_register_matches(hbh_mt6_reg, ARRAY_SIZE(hbh_mt6_reg)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 207 | } |
| 208 | |
Jan Engelhardt | d3c5ee6 | 2007-12-04 23:24:03 -0800 | [diff] [blame] | 209 | static void __exit hbh_mt6_exit(void) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 210 | { |
Jan Engelhardt | d3c5ee6 | 2007-12-04 23:24:03 -0800 | [diff] [blame] | 211 | xt_unregister_matches(hbh_mt6_reg, ARRAY_SIZE(hbh_mt6_reg)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 212 | } |
| 213 | |
Jan Engelhardt | d3c5ee6 | 2007-12-04 23:24:03 -0800 | [diff] [blame] | 214 | module_init(hbh_mt6_init); |
| 215 | module_exit(hbh_mt6_exit); |