Jan Engelhardt | be91fd5 | 2010-03-18 02:22:32 +0100 | [diff] [blame^] | 1 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2 | #include <linux/module.h> |
| 3 | #include <linux/skbuff.h> |
| 4 | #include <net/ip.h> |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 5 | #include <net/ipv6.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 6 | #include <linux/sctp.h> |
| 7 | |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 8 | #include <linux/netfilter/x_tables.h> |
| 9 | #include <linux/netfilter/xt_sctp.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 10 | #include <linux/netfilter_ipv4/ip_tables.h> |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 11 | #include <linux/netfilter_ipv6/ip6_tables.h> |
| 12 | |
| 13 | MODULE_LICENSE("GPL"); |
| 14 | MODULE_AUTHOR("Kiran Kumar Immidi"); |
Jan Engelhardt | 2ae15b6 | 2008-01-14 23:42:28 -0800 | [diff] [blame] | 15 | MODULE_DESCRIPTION("Xtables: SCTP protocol packet match"); |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 16 | MODULE_ALIAS("ipt_sctp"); |
Jan Engelhardt | 73aaf93 | 2007-10-11 14:36:40 -0700 | [diff] [blame] | 17 | MODULE_ALIAS("ip6t_sctp"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 18 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 19 | #define SCCHECK(cond, option, flag, invflag) (!((flag) & (option)) \ |
| 20 | || (!!((invflag) & (option)) ^ (cond))) |
| 21 | |
Jan Engelhardt | 1d93a9c | 2007-07-07 22:15:35 -0700 | [diff] [blame] | 22 | static bool |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 23 | match_flags(const struct xt_sctp_flag_info *flag_info, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 24 | const int flag_count, |
| 25 | u_int8_t chunktype, |
| 26 | u_int8_t chunkflags) |
| 27 | { |
| 28 | int i; |
| 29 | |
Jan Engelhardt | 7c4e36b | 2007-07-07 22:19:08 -0700 | [diff] [blame] | 30 | for (i = 0; i < flag_count; i++) |
| 31 | if (flag_info[i].chunktype == chunktype) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 32 | return (chunkflags & flag_info[i].flag_mask) == flag_info[i].flag; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 33 | |
Jan Engelhardt | 1d93a9c | 2007-07-07 22:15:35 -0700 | [diff] [blame] | 34 | return true; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 35 | } |
| 36 | |
Jan Engelhardt | 1d93a9c | 2007-07-07 22:15:35 -0700 | [diff] [blame] | 37 | static inline bool |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 38 | match_packet(const struct sk_buff *skb, |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 39 | unsigned int offset, |
Li Zefan | 009e8c9 | 2007-10-18 05:12:21 -0700 | [diff] [blame] | 40 | const struct xt_sctp_info *info, |
Jan Engelhardt | cff533a | 2007-07-07 22:15:12 -0700 | [diff] [blame] | 41 | bool *hotdrop) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 42 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 43 | u_int32_t chunkmapcopy[256 / sizeof (u_int32_t)]; |
Jan Engelhardt | 3cf93c9 | 2008-04-14 09:56:05 +0200 | [diff] [blame] | 44 | const sctp_chunkhdr_t *sch; |
| 45 | sctp_chunkhdr_t _sch; |
Li Zefan | 009e8c9 | 2007-10-18 05:12:21 -0700 | [diff] [blame] | 46 | int chunk_match_type = info->chunk_match_type; |
| 47 | const struct xt_sctp_flag_info *flag_info = info->flag_info; |
| 48 | int flag_count = info->flag_count; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 49 | |
Jan Engelhardt | be91fd5 | 2010-03-18 02:22:32 +0100 | [diff] [blame^] | 50 | #ifdef DEBUG |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 51 | int i = 0; |
| 52 | #endif |
| 53 | |
Jan Engelhardt | 7c4e36b | 2007-07-07 22:19:08 -0700 | [diff] [blame] | 54 | if (chunk_match_type == SCTP_CHUNK_MATCH_ALL) |
Li Zefan | 009e8c9 | 2007-10-18 05:12:21 -0700 | [diff] [blame] | 55 | SCTP_CHUNKMAP_COPY(chunkmapcopy, info->chunkmap); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 56 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 57 | do { |
| 58 | sch = skb_header_pointer(skb, offset, sizeof(_sch), &_sch); |
Patrick McHardy | d3dcd4e | 2006-06-19 23:39:45 -0700 | [diff] [blame] | 59 | if (sch == NULL || sch->length == 0) { |
Jan Engelhardt | be91fd5 | 2010-03-18 02:22:32 +0100 | [diff] [blame^] | 60 | pr_debug("Dropping invalid SCTP packet.\n"); |
Jan Engelhardt | cff533a | 2007-07-07 22:15:12 -0700 | [diff] [blame] | 61 | *hotdrop = true; |
Jan Engelhardt | 1d93a9c | 2007-07-07 22:15:35 -0700 | [diff] [blame] | 62 | return false; |
YOSHIFUJI Hideaki | 601e68e | 2007-02-12 11:15:49 -0800 | [diff] [blame] | 63 | } |
Jan Engelhardt | be91fd5 | 2010-03-18 02:22:32 +0100 | [diff] [blame^] | 64 | #ifdef DEBUG |
| 65 | pr_debug("Chunk num: %d\toffset: %d\ttype: %d\tlength: %d" |
| 66 | "\tflags: %x\n", |
| 67 | ++i, offset, sch->type, htons(sch->length), |
| 68 | sch->flags); |
| 69 | #endif |
Al Viro | 962c837 | 2006-11-20 17:26:08 -0800 | [diff] [blame] | 70 | offset += (ntohs(sch->length) + 3) & ~3; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 71 | |
Jan Engelhardt | be91fd5 | 2010-03-18 02:22:32 +0100 | [diff] [blame^] | 72 | pr_debug("skb->len: %d\toffset: %d\n", skb->len, offset); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 73 | |
Li Zefan | 009e8c9 | 2007-10-18 05:12:21 -0700 | [diff] [blame] | 74 | if (SCTP_CHUNKMAP_IS_SET(info->chunkmap, sch->type)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 75 | switch (chunk_match_type) { |
| 76 | case SCTP_CHUNK_MATCH_ANY: |
YOSHIFUJI Hideaki | 601e68e | 2007-02-12 11:15:49 -0800 | [diff] [blame] | 77 | if (match_flags(flag_info, flag_count, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 78 | sch->type, sch->flags)) { |
Jan Engelhardt | 1d93a9c | 2007-07-07 22:15:35 -0700 | [diff] [blame] | 79 | return true; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 80 | } |
| 81 | break; |
| 82 | |
| 83 | case SCTP_CHUNK_MATCH_ALL: |
YOSHIFUJI Hideaki | 601e68e | 2007-02-12 11:15:49 -0800 | [diff] [blame] | 84 | if (match_flags(flag_info, flag_count, |
Jan Engelhardt | 7c4e36b | 2007-07-07 22:19:08 -0700 | [diff] [blame] | 85 | sch->type, sch->flags)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 86 | SCTP_CHUNKMAP_CLEAR(chunkmapcopy, sch->type); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 87 | break; |
| 88 | |
| 89 | case SCTP_CHUNK_MATCH_ONLY: |
YOSHIFUJI Hideaki | 601e68e | 2007-02-12 11:15:49 -0800 | [diff] [blame] | 90 | if (!match_flags(flag_info, flag_count, |
Jan Engelhardt | 7c4e36b | 2007-07-07 22:19:08 -0700 | [diff] [blame] | 91 | sch->type, sch->flags)) |
Jan Engelhardt | 1d93a9c | 2007-07-07 22:15:35 -0700 | [diff] [blame] | 92 | return false; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 93 | break; |
| 94 | } |
| 95 | } else { |
| 96 | switch (chunk_match_type) { |
| 97 | case SCTP_CHUNK_MATCH_ONLY: |
Jan Engelhardt | 1d93a9c | 2007-07-07 22:15:35 -0700 | [diff] [blame] | 98 | return false; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 99 | } |
| 100 | } |
| 101 | } while (offset < skb->len); |
| 102 | |
| 103 | switch (chunk_match_type) { |
| 104 | case SCTP_CHUNK_MATCH_ALL: |
Qu Haoran | d4e2675 | 2009-02-09 14:34:56 -0800 | [diff] [blame] | 105 | return SCTP_CHUNKMAP_IS_CLEAR(chunkmapcopy); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 106 | case SCTP_CHUNK_MATCH_ANY: |
Jan Engelhardt | 1d93a9c | 2007-07-07 22:15:35 -0700 | [diff] [blame] | 107 | return false; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 108 | case SCTP_CHUNK_MATCH_ONLY: |
Jan Engelhardt | 1d93a9c | 2007-07-07 22:15:35 -0700 | [diff] [blame] | 109 | return true; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 110 | } |
| 111 | |
| 112 | /* This will never be reached, but required to stop compiler whine */ |
Jan Engelhardt | 1d93a9c | 2007-07-07 22:15:35 -0700 | [diff] [blame] | 113 | return false; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 114 | } |
| 115 | |
Jan Engelhardt | 1d93a9c | 2007-07-07 22:15:35 -0700 | [diff] [blame] | 116 | static bool |
Jan Engelhardt | f7108a2 | 2008-10-08 11:35:18 +0200 | [diff] [blame] | 117 | sctp_mt(const struct sk_buff *skb, const struct xt_match_param *par) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 118 | { |
Jan Engelhardt | f7108a2 | 2008-10-08 11:35:18 +0200 | [diff] [blame] | 119 | const struct xt_sctp_info *info = par->matchinfo; |
Jan Engelhardt | 3cf93c9 | 2008-04-14 09:56:05 +0200 | [diff] [blame] | 120 | const sctp_sctphdr_t *sh; |
| 121 | sctp_sctphdr_t _sh; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 122 | |
Jan Engelhardt | f7108a2 | 2008-10-08 11:35:18 +0200 | [diff] [blame] | 123 | if (par->fragoff != 0) { |
Jan Engelhardt | be91fd5 | 2010-03-18 02:22:32 +0100 | [diff] [blame^] | 124 | pr_debug("Dropping non-first fragment.. FIXME\n"); |
Jan Engelhardt | 1d93a9c | 2007-07-07 22:15:35 -0700 | [diff] [blame] | 125 | return false; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 126 | } |
YOSHIFUJI Hideaki | 601e68e | 2007-02-12 11:15:49 -0800 | [diff] [blame] | 127 | |
Jan Engelhardt | f7108a2 | 2008-10-08 11:35:18 +0200 | [diff] [blame] | 128 | sh = skb_header_pointer(skb, par->thoff, sizeof(_sh), &_sh); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 129 | if (sh == NULL) { |
Jan Engelhardt | be91fd5 | 2010-03-18 02:22:32 +0100 | [diff] [blame^] | 130 | pr_debug("Dropping evil TCP offset=0 tinygram.\n"); |
Jan Engelhardt | f7108a2 | 2008-10-08 11:35:18 +0200 | [diff] [blame] | 131 | *par->hotdrop = true; |
Jan Engelhardt | 1d93a9c | 2007-07-07 22:15:35 -0700 | [diff] [blame] | 132 | return false; |
YOSHIFUJI Hideaki | 601e68e | 2007-02-12 11:15:49 -0800 | [diff] [blame] | 133 | } |
Jan Engelhardt | be91fd5 | 2010-03-18 02:22:32 +0100 | [diff] [blame^] | 134 | pr_debug("spt: %d\tdpt: %d\n", ntohs(sh->source), ntohs(sh->dest)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 135 | |
Jan Engelhardt | 7c4e36b | 2007-07-07 22:19:08 -0700 | [diff] [blame] | 136 | return SCCHECK(ntohs(sh->source) >= info->spts[0] |
| 137 | && ntohs(sh->source) <= info->spts[1], |
YOSHIFUJI Hideaki | 601e68e | 2007-02-12 11:15:49 -0800 | [diff] [blame] | 138 | XT_SCTP_SRC_PORTS, info->flags, info->invflags) |
Jan Engelhardt | 7c4e36b | 2007-07-07 22:19:08 -0700 | [diff] [blame] | 139 | && SCCHECK(ntohs(sh->dest) >= info->dpts[0] |
| 140 | && ntohs(sh->dest) <= info->dpts[1], |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 141 | XT_SCTP_DEST_PORTS, info->flags, info->invflags) |
Jan Engelhardt | f7108a2 | 2008-10-08 11:35:18 +0200 | [diff] [blame] | 142 | && SCCHECK(match_packet(skb, par->thoff + sizeof(sctp_sctphdr_t), |
| 143 | info, par->hotdrop), |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 144 | XT_SCTP_CHUNK_TYPES, info->flags, info->invflags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 145 | } |
| 146 | |
Jan Engelhardt | 9b4fce7 | 2008-10-08 11:35:18 +0200 | [diff] [blame] | 147 | static bool sctp_mt_check(const struct xt_mtchk_param *par) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 148 | { |
Jan Engelhardt | 9b4fce7 | 2008-10-08 11:35:18 +0200 | [diff] [blame] | 149 | const struct xt_sctp_info *info = par->matchinfo; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 150 | |
Patrick McHardy | 5d04bff | 2006-03-20 18:01:58 -0800 | [diff] [blame] | 151 | return !(info->flags & ~XT_SCTP_VALID_FLAGS) |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 152 | && !(info->invflags & ~XT_SCTP_VALID_FLAGS) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 153 | && !(info->invflags & ~info->flags) |
YOSHIFUJI Hideaki | 601e68e | 2007-02-12 11:15:49 -0800 | [diff] [blame] | 154 | && ((!(info->flags & XT_SCTP_CHUNK_TYPES)) || |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 155 | (info->chunk_match_type & |
YOSHIFUJI Hideaki | 601e68e | 2007-02-12 11:15:49 -0800 | [diff] [blame] | 156 | (SCTP_CHUNK_MATCH_ALL |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 157 | | SCTP_CHUNK_MATCH_ANY |
| 158 | | SCTP_CHUNK_MATCH_ONLY))); |
| 159 | } |
| 160 | |
Jan Engelhardt | d3c5ee6 | 2007-12-04 23:24:03 -0800 | [diff] [blame] | 161 | static struct xt_match sctp_mt_reg[] __read_mostly = { |
Patrick McHardy | 4470bbc | 2006-08-22 00:34:04 -0700 | [diff] [blame] | 162 | { |
| 163 | .name = "sctp", |
Jan Engelhardt | ee999d8 | 2008-10-08 11:35:01 +0200 | [diff] [blame] | 164 | .family = NFPROTO_IPV4, |
Jan Engelhardt | d3c5ee6 | 2007-12-04 23:24:03 -0800 | [diff] [blame] | 165 | .checkentry = sctp_mt_check, |
| 166 | .match = sctp_mt, |
Patrick McHardy | 4470bbc | 2006-08-22 00:34:04 -0700 | [diff] [blame] | 167 | .matchsize = sizeof(struct xt_sctp_info), |
| 168 | .proto = IPPROTO_SCTP, |
| 169 | .me = THIS_MODULE |
| 170 | }, |
| 171 | { |
| 172 | .name = "sctp", |
Jan Engelhardt | ee999d8 | 2008-10-08 11:35:01 +0200 | [diff] [blame] | 173 | .family = NFPROTO_IPV6, |
Jan Engelhardt | d3c5ee6 | 2007-12-04 23:24:03 -0800 | [diff] [blame] | 174 | .checkentry = sctp_mt_check, |
| 175 | .match = sctp_mt, |
Patrick McHardy | 4470bbc | 2006-08-22 00:34:04 -0700 | [diff] [blame] | 176 | .matchsize = sizeof(struct xt_sctp_info), |
| 177 | .proto = IPPROTO_SCTP, |
| 178 | .me = THIS_MODULE |
| 179 | }, |
Patrick McHardy | 5d04bff | 2006-03-20 18:01:58 -0800 | [diff] [blame] | 180 | }; |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 181 | |
Jan Engelhardt | d3c5ee6 | 2007-12-04 23:24:03 -0800 | [diff] [blame] | 182 | static int __init sctp_mt_init(void) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 183 | { |
Jan Engelhardt | d3c5ee6 | 2007-12-04 23:24:03 -0800 | [diff] [blame] | 184 | return xt_register_matches(sctp_mt_reg, ARRAY_SIZE(sctp_mt_reg)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 185 | } |
| 186 | |
Jan Engelhardt | d3c5ee6 | 2007-12-04 23:24:03 -0800 | [diff] [blame] | 187 | static void __exit sctp_mt_exit(void) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 188 | { |
Jan Engelhardt | d3c5ee6 | 2007-12-04 23:24:03 -0800 | [diff] [blame] | 189 | xt_unregister_matches(sctp_mt_reg, ARRAY_SIZE(sctp_mt_reg)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 190 | } |
| 191 | |
Jan Engelhardt | d3c5ee6 | 2007-12-04 23:24:03 -0800 | [diff] [blame] | 192 | module_init(sctp_mt_init); |
| 193 | module_exit(sctp_mt_exit); |