Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | #include <linux/module.h> |
| 2 | #include <linux/skbuff.h> |
| 3 | #include <net/ip.h> |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 4 | #include <net/ipv6.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 5 | #include <linux/sctp.h> |
| 6 | |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 7 | #include <linux/netfilter/x_tables.h> |
| 8 | #include <linux/netfilter/xt_sctp.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 9 | #include <linux/netfilter_ipv4/ip_tables.h> |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 10 | #include <linux/netfilter_ipv6/ip6_tables.h> |
| 11 | |
| 12 | MODULE_LICENSE("GPL"); |
| 13 | MODULE_AUTHOR("Kiran Kumar Immidi"); |
Jan Engelhardt | 2ae15b6 | 2008-01-14 23:42:28 -0800 | [diff] [blame] | 14 | MODULE_DESCRIPTION("Xtables: SCTP protocol packet match"); |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 15 | MODULE_ALIAS("ipt_sctp"); |
Jan Engelhardt | 73aaf93 | 2007-10-11 14:36:40 -0700 | [diff] [blame] | 16 | MODULE_ALIAS("ip6t_sctp"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 17 | |
| 18 | #ifdef DEBUG_SCTP |
| 19 | #define duprintf(format, args...) printk(format , ## args) |
| 20 | #else |
| 21 | #define duprintf(format, args...) |
| 22 | #endif |
| 23 | |
| 24 | #define SCCHECK(cond, option, flag, invflag) (!((flag) & (option)) \ |
| 25 | || (!!((invflag) & (option)) ^ (cond))) |
| 26 | |
Jan Engelhardt | 1d93a9c | 2007-07-07 22:15:35 -0700 | [diff] [blame] | 27 | static bool |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 28 | match_flags(const struct xt_sctp_flag_info *flag_info, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 29 | const int flag_count, |
| 30 | u_int8_t chunktype, |
| 31 | u_int8_t chunkflags) |
| 32 | { |
| 33 | int i; |
| 34 | |
Jan Engelhardt | 7c4e36b | 2007-07-07 22:19:08 -0700 | [diff] [blame] | 35 | for (i = 0; i < flag_count; i++) |
| 36 | if (flag_info[i].chunktype == chunktype) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 37 | return (chunkflags & flag_info[i].flag_mask) == flag_info[i].flag; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 38 | |
Jan Engelhardt | 1d93a9c | 2007-07-07 22:15:35 -0700 | [diff] [blame] | 39 | return true; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 40 | } |
| 41 | |
Jan Engelhardt | 1d93a9c | 2007-07-07 22:15:35 -0700 | [diff] [blame] | 42 | static inline bool |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 43 | match_packet(const struct sk_buff *skb, |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 44 | unsigned int offset, |
Li Zefan | 009e8c9 | 2007-10-18 05:12:21 -0700 | [diff] [blame] | 45 | const struct xt_sctp_info *info, |
Jan Engelhardt | cff533a | 2007-07-07 22:15:12 -0700 | [diff] [blame] | 46 | bool *hotdrop) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 47 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 48 | u_int32_t chunkmapcopy[256 / sizeof (u_int32_t)]; |
Jan Engelhardt | 3cf93c9 | 2008-04-14 09:56:05 +0200 | [diff] [blame] | 49 | const sctp_chunkhdr_t *sch; |
| 50 | sctp_chunkhdr_t _sch; |
Li Zefan | 009e8c9 | 2007-10-18 05:12:21 -0700 | [diff] [blame] | 51 | int chunk_match_type = info->chunk_match_type; |
| 52 | const struct xt_sctp_flag_info *flag_info = info->flag_info; |
| 53 | int flag_count = info->flag_count; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 54 | |
| 55 | #ifdef DEBUG_SCTP |
| 56 | int i = 0; |
| 57 | #endif |
| 58 | |
Jan Engelhardt | 7c4e36b | 2007-07-07 22:19:08 -0700 | [diff] [blame] | 59 | if (chunk_match_type == SCTP_CHUNK_MATCH_ALL) |
Li Zefan | 009e8c9 | 2007-10-18 05:12:21 -0700 | [diff] [blame] | 60 | SCTP_CHUNKMAP_COPY(chunkmapcopy, info->chunkmap); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 61 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 62 | do { |
| 63 | sch = skb_header_pointer(skb, offset, sizeof(_sch), &_sch); |
Patrick McHardy | d3dcd4e | 2006-06-19 23:39:45 -0700 | [diff] [blame] | 64 | if (sch == NULL || sch->length == 0) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 65 | duprintf("Dropping invalid SCTP packet.\n"); |
Jan Engelhardt | cff533a | 2007-07-07 22:15:12 -0700 | [diff] [blame] | 66 | *hotdrop = true; |
Jan Engelhardt | 1d93a9c | 2007-07-07 22:15:35 -0700 | [diff] [blame] | 67 | return false; |
YOSHIFUJI Hideaki | 601e68e | 2007-02-12 11:15:49 -0800 | [diff] [blame] | 68 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 69 | |
YOSHIFUJI Hideaki | 601e68e | 2007-02-12 11:15:49 -0800 | [diff] [blame] | 70 | duprintf("Chunk num: %d\toffset: %d\ttype: %d\tlength: %d\tflags: %x\n", |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 71 | ++i, offset, sch->type, htons(sch->length), sch->flags); |
| 72 | |
Al Viro | 962c837 | 2006-11-20 17:26:08 -0800 | [diff] [blame] | 73 | offset += (ntohs(sch->length) + 3) & ~3; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 74 | |
| 75 | duprintf("skb->len: %d\toffset: %d\n", skb->len, offset); |
| 76 | |
Li Zefan | 009e8c9 | 2007-10-18 05:12:21 -0700 | [diff] [blame] | 77 | if (SCTP_CHUNKMAP_IS_SET(info->chunkmap, sch->type)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 78 | switch (chunk_match_type) { |
| 79 | case SCTP_CHUNK_MATCH_ANY: |
YOSHIFUJI Hideaki | 601e68e | 2007-02-12 11:15:49 -0800 | [diff] [blame] | 80 | if (match_flags(flag_info, flag_count, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 81 | sch->type, sch->flags)) { |
Jan Engelhardt | 1d93a9c | 2007-07-07 22:15:35 -0700 | [diff] [blame] | 82 | return true; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 83 | } |
| 84 | break; |
| 85 | |
| 86 | case SCTP_CHUNK_MATCH_ALL: |
YOSHIFUJI Hideaki | 601e68e | 2007-02-12 11:15:49 -0800 | [diff] [blame] | 87 | if (match_flags(flag_info, flag_count, |
Jan Engelhardt | 7c4e36b | 2007-07-07 22:19:08 -0700 | [diff] [blame] | 88 | sch->type, sch->flags)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 89 | SCTP_CHUNKMAP_CLEAR(chunkmapcopy, sch->type); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 90 | break; |
| 91 | |
| 92 | case SCTP_CHUNK_MATCH_ONLY: |
YOSHIFUJI Hideaki | 601e68e | 2007-02-12 11:15:49 -0800 | [diff] [blame] | 93 | if (!match_flags(flag_info, flag_count, |
Jan Engelhardt | 7c4e36b | 2007-07-07 22:19:08 -0700 | [diff] [blame] | 94 | sch->type, sch->flags)) |
Jan Engelhardt | 1d93a9c | 2007-07-07 22:15:35 -0700 | [diff] [blame] | 95 | return false; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 96 | break; |
| 97 | } |
| 98 | } else { |
| 99 | switch (chunk_match_type) { |
| 100 | case SCTP_CHUNK_MATCH_ONLY: |
Jan Engelhardt | 1d93a9c | 2007-07-07 22:15:35 -0700 | [diff] [blame] | 101 | return false; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 102 | } |
| 103 | } |
| 104 | } while (offset < skb->len); |
| 105 | |
| 106 | switch (chunk_match_type) { |
| 107 | case SCTP_CHUNK_MATCH_ALL: |
Li Zefan | 009e8c9 | 2007-10-18 05:12:21 -0700 | [diff] [blame] | 108 | return SCTP_CHUNKMAP_IS_CLEAR(info->chunkmap); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 109 | case SCTP_CHUNK_MATCH_ANY: |
Jan Engelhardt | 1d93a9c | 2007-07-07 22:15:35 -0700 | [diff] [blame] | 110 | return false; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 111 | case SCTP_CHUNK_MATCH_ONLY: |
Jan Engelhardt | 1d93a9c | 2007-07-07 22:15:35 -0700 | [diff] [blame] | 112 | return true; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 113 | } |
| 114 | |
| 115 | /* This will never be reached, but required to stop compiler whine */ |
Jan Engelhardt | 1d93a9c | 2007-07-07 22:15:35 -0700 | [diff] [blame] | 116 | return false; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 117 | } |
| 118 | |
Jan Engelhardt | 1d93a9c | 2007-07-07 22:15:35 -0700 | [diff] [blame] | 119 | static bool |
Jan Engelhardt | d3c5ee6 | 2007-12-04 23:24:03 -0800 | [diff] [blame] | 120 | sctp_mt(const struct sk_buff *skb, const struct net_device *in, |
| 121 | const struct net_device *out, const struct xt_match *match, |
| 122 | const void *matchinfo, int offset, unsigned int protoff, bool *hotdrop) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 123 | { |
Patrick McHardy | 3e72b2f | 2006-05-29 18:19:19 -0700 | [diff] [blame] | 124 | const struct xt_sctp_info *info = matchinfo; |
Jan Engelhardt | 3cf93c9 | 2008-04-14 09:56:05 +0200 | [diff] [blame] | 125 | const sctp_sctphdr_t *sh; |
| 126 | sctp_sctphdr_t _sh; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 127 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 128 | if (offset) { |
| 129 | duprintf("Dropping non-first fragment.. FIXME\n"); |
Jan Engelhardt | 1d93a9c | 2007-07-07 22:15:35 -0700 | [diff] [blame] | 130 | return false; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 131 | } |
YOSHIFUJI Hideaki | 601e68e | 2007-02-12 11:15:49 -0800 | [diff] [blame] | 132 | |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 133 | sh = skb_header_pointer(skb, protoff, sizeof(_sh), &_sh); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 134 | if (sh == NULL) { |
| 135 | duprintf("Dropping evil TCP offset=0 tinygram.\n"); |
Jan Engelhardt | cff533a | 2007-07-07 22:15:12 -0700 | [diff] [blame] | 136 | *hotdrop = true; |
Jan Engelhardt | 1d93a9c | 2007-07-07 22:15:35 -0700 | [diff] [blame] | 137 | return false; |
YOSHIFUJI Hideaki | 601e68e | 2007-02-12 11:15:49 -0800 | [diff] [blame] | 138 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 139 | duprintf("spt: %d\tdpt: %d\n", ntohs(sh->source), ntohs(sh->dest)); |
| 140 | |
Jan Engelhardt | 7c4e36b | 2007-07-07 22:19:08 -0700 | [diff] [blame] | 141 | return SCCHECK(ntohs(sh->source) >= info->spts[0] |
| 142 | && ntohs(sh->source) <= info->spts[1], |
YOSHIFUJI Hideaki | 601e68e | 2007-02-12 11:15:49 -0800 | [diff] [blame] | 143 | XT_SCTP_SRC_PORTS, info->flags, info->invflags) |
Jan Engelhardt | 7c4e36b | 2007-07-07 22:19:08 -0700 | [diff] [blame] | 144 | && SCCHECK(ntohs(sh->dest) >= info->dpts[0] |
| 145 | && ntohs(sh->dest) <= info->dpts[1], |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 146 | XT_SCTP_DEST_PORTS, info->flags, info->invflags) |
Jorge Matias | 1c7e477 | 2006-06-27 03:01:25 -0700 | [diff] [blame] | 147 | && SCCHECK(match_packet(skb, protoff + sizeof (sctp_sctphdr_t), |
Li Zefan | 009e8c9 | 2007-10-18 05:12:21 -0700 | [diff] [blame] | 148 | info, hotdrop), |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 149 | XT_SCTP_CHUNK_TYPES, info->flags, info->invflags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 150 | } |
| 151 | |
Jan Engelhardt | ccb79bd | 2007-07-07 22:16:00 -0700 | [diff] [blame] | 152 | static bool |
Jan Engelhardt | d3c5ee6 | 2007-12-04 23:24:03 -0800 | [diff] [blame] | 153 | sctp_mt_check(const char *tablename, const void *inf, |
| 154 | const struct xt_match *match, void *matchinfo, |
| 155 | unsigned int hook_mask) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 156 | { |
Patrick McHardy | 5d04bff | 2006-03-20 18:01:58 -0800 | [diff] [blame] | 157 | const struct xt_sctp_info *info = matchinfo; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 158 | |
Patrick McHardy | 5d04bff | 2006-03-20 18:01:58 -0800 | [diff] [blame] | 159 | return !(info->flags & ~XT_SCTP_VALID_FLAGS) |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 160 | && !(info->invflags & ~XT_SCTP_VALID_FLAGS) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 161 | && !(info->invflags & ~info->flags) |
YOSHIFUJI Hideaki | 601e68e | 2007-02-12 11:15:49 -0800 | [diff] [blame] | 162 | && ((!(info->flags & XT_SCTP_CHUNK_TYPES)) || |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 163 | (info->chunk_match_type & |
YOSHIFUJI Hideaki | 601e68e | 2007-02-12 11:15:49 -0800 | [diff] [blame] | 164 | (SCTP_CHUNK_MATCH_ALL |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 165 | | SCTP_CHUNK_MATCH_ANY |
| 166 | | SCTP_CHUNK_MATCH_ONLY))); |
| 167 | } |
| 168 | |
Jan Engelhardt | d3c5ee6 | 2007-12-04 23:24:03 -0800 | [diff] [blame] | 169 | static struct xt_match sctp_mt_reg[] __read_mostly = { |
Patrick McHardy | 4470bbc | 2006-08-22 00:34:04 -0700 | [diff] [blame] | 170 | { |
| 171 | .name = "sctp", |
| 172 | .family = AF_INET, |
Jan Engelhardt | d3c5ee6 | 2007-12-04 23:24:03 -0800 | [diff] [blame] | 173 | .checkentry = sctp_mt_check, |
| 174 | .match = sctp_mt, |
Patrick McHardy | 4470bbc | 2006-08-22 00:34:04 -0700 | [diff] [blame] | 175 | .matchsize = sizeof(struct xt_sctp_info), |
| 176 | .proto = IPPROTO_SCTP, |
| 177 | .me = THIS_MODULE |
| 178 | }, |
| 179 | { |
| 180 | .name = "sctp", |
| 181 | .family = AF_INET6, |
Jan Engelhardt | d3c5ee6 | 2007-12-04 23:24:03 -0800 | [diff] [blame] | 182 | .checkentry = sctp_mt_check, |
| 183 | .match = sctp_mt, |
Patrick McHardy | 4470bbc | 2006-08-22 00:34:04 -0700 | [diff] [blame] | 184 | .matchsize = sizeof(struct xt_sctp_info), |
| 185 | .proto = IPPROTO_SCTP, |
| 186 | .me = THIS_MODULE |
| 187 | }, |
Patrick McHardy | 5d04bff | 2006-03-20 18:01:58 -0800 | [diff] [blame] | 188 | }; |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 189 | |
Jan Engelhardt | d3c5ee6 | 2007-12-04 23:24:03 -0800 | [diff] [blame] | 190 | static int __init sctp_mt_init(void) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 191 | { |
Jan Engelhardt | d3c5ee6 | 2007-12-04 23:24:03 -0800 | [diff] [blame] | 192 | return xt_register_matches(sctp_mt_reg, ARRAY_SIZE(sctp_mt_reg)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 193 | } |
| 194 | |
Jan Engelhardt | d3c5ee6 | 2007-12-04 23:24:03 -0800 | [diff] [blame] | 195 | static void __exit sctp_mt_exit(void) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 196 | { |
Jan Engelhardt | d3c5ee6 | 2007-12-04 23:24:03 -0800 | [diff] [blame] | 197 | xt_unregister_matches(sctp_mt_reg, ARRAY_SIZE(sctp_mt_reg)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 198 | } |
| 199 | |
Jan Engelhardt | d3c5ee6 | 2007-12-04 23:24:03 -0800 | [diff] [blame] | 200 | module_init(sctp_mt_init); |
| 201 | module_exit(sctp_mt_exit); |