MODULE_LICENSE("GPL");
MODULE_AUTHOR("Kiran Kumar Immidi");
-MODULE_DESCRIPTION("Match for SCTP protocol packets");
+MODULE_DESCRIPTION("Xtables: SCTP protocol packet match");
MODULE_ALIAS("ipt_sctp");
+MODULE_ALIAS("ip6t_sctp");
#ifdef DEBUG_SCTP
#define duprintf(format, args...) printk(format , ## args)
#define SCCHECK(cond, option, flag, invflag) (!((flag) & (option)) \
|| (!!((invflag) & (option)) ^ (cond)))
-static int
+static bool
match_flags(const struct xt_sctp_flag_info *flag_info,
const int flag_count,
u_int8_t chunktype,
{
int i;
- for (i = 0; i < flag_count; i++) {
- if (flag_info[i].chunktype == chunktype) {
+ for (i = 0; i < flag_count; i++)
+ if (flag_info[i].chunktype == chunktype)
return (chunkflags & flag_info[i].flag_mask) == flag_info[i].flag;
- }
- }
- return 1;
+ return true;
}
-static inline int
+static inline bool
match_packet(const struct sk_buff *skb,
unsigned int offset,
- const u_int32_t *chunkmap,
- int chunk_match_type,
- const struct xt_sctp_flag_info *flag_info,
- const int flag_count,
- int *hotdrop)
+ const struct xt_sctp_info *info,
+ bool *hotdrop)
{
u_int32_t chunkmapcopy[256 / sizeof (u_int32_t)];
- sctp_chunkhdr_t _sch, *sch;
+ const sctp_chunkhdr_t *sch;
+ sctp_chunkhdr_t _sch;
+ int chunk_match_type = info->chunk_match_type;
+ const struct xt_sctp_flag_info *flag_info = info->flag_info;
+ int flag_count = info->flag_count;
#ifdef DEBUG_SCTP
int i = 0;
#endif
- if (chunk_match_type == SCTP_CHUNK_MATCH_ALL) {
- SCTP_CHUNKMAP_COPY(chunkmapcopy, chunkmap);
- }
+ if (chunk_match_type == SCTP_CHUNK_MATCH_ALL)
+ SCTP_CHUNKMAP_COPY(chunkmapcopy, info->chunkmap);
do {
sch = skb_header_pointer(skb, offset, sizeof(_sch), &_sch);
- if (sch == NULL) {
+ if (sch == NULL || sch->length == 0) {
duprintf("Dropping invalid SCTP packet.\n");
- *hotdrop = 1;
- return 0;
- }
+ *hotdrop = true;
+ return false;
+ }
- duprintf("Chunk num: %d\toffset: %d\ttype: %d\tlength: %d\tflags: %x\n",
+ duprintf("Chunk num: %d\toffset: %d\ttype: %d\tlength: %d\tflags: %x\n",
++i, offset, sch->type, htons(sch->length), sch->flags);
- offset += (htons(sch->length) + 3) & ~3;
+ offset += (ntohs(sch->length) + 3) & ~3;
duprintf("skb->len: %d\toffset: %d\n", skb->len, offset);
- if (SCTP_CHUNKMAP_IS_SET(chunkmap, sch->type)) {
+ if (SCTP_CHUNKMAP_IS_SET(info->chunkmap, sch->type)) {
switch (chunk_match_type) {
case SCTP_CHUNK_MATCH_ANY:
- if (match_flags(flag_info, flag_count,
+ if (match_flags(flag_info, flag_count,
sch->type, sch->flags)) {
- return 1;
+ return true;
}
break;
case SCTP_CHUNK_MATCH_ALL:
- if (match_flags(flag_info, flag_count,
- sch->type, sch->flags)) {
+ if (match_flags(flag_info, flag_count,
+ sch->type, sch->flags))
SCTP_CHUNKMAP_CLEAR(chunkmapcopy, sch->type);
- }
break;
case SCTP_CHUNK_MATCH_ONLY:
- if (!match_flags(flag_info, flag_count,
- sch->type, sch->flags)) {
- return 0;
- }
+ if (!match_flags(flag_info, flag_count,
+ sch->type, sch->flags))
+ return false;
break;
}
} else {
switch (chunk_match_type) {
case SCTP_CHUNK_MATCH_ONLY:
- return 0;
+ return false;
}
}
} while (offset < skb->len);
switch (chunk_match_type) {
case SCTP_CHUNK_MATCH_ALL:
- return SCTP_CHUNKMAP_IS_CLEAR(chunkmap);
+ return SCTP_CHUNKMAP_IS_CLEAR(info->chunkmap);
case SCTP_CHUNK_MATCH_ANY:
- return 0;
+ return false;
case SCTP_CHUNK_MATCH_ONLY:
- return 1;
+ return true;
}
/* This will never be reached, but required to stop compiler whine */
- return 0;
+ return false;
}
-static int
-match(const struct sk_buff *skb,
- const struct net_device *in,
- const struct net_device *out,
- const struct xt_match *match,
- const void *matchinfo,
- int offset,
- unsigned int protoff,
- int *hotdrop)
+static bool
+sctp_mt(const struct sk_buff *skb, const struct xt_match_param *par)
{
- const struct xt_sctp_info *info;
- sctp_sctphdr_t _sh, *sh;
+ const struct xt_sctp_info *info = par->matchinfo;
+ const sctp_sctphdr_t *sh;
+ sctp_sctphdr_t _sh;
- info = (const struct xt_sctp_info *)matchinfo;
-
- if (offset) {
+ if (par->fragoff != 0) {
duprintf("Dropping non-first fragment.. FIXME\n");
- return 0;
+ return false;
}
-
- sh = skb_header_pointer(skb, protoff, sizeof(_sh), &_sh);
+
+ sh = skb_header_pointer(skb, par->thoff, sizeof(_sh), &_sh);
if (sh == NULL) {
duprintf("Dropping evil TCP offset=0 tinygram.\n");
- *hotdrop = 1;
- return 0;
- }
+ *par->hotdrop = true;
+ return false;
+ }
duprintf("spt: %d\tdpt: %d\n", ntohs(sh->source), ntohs(sh->dest));
- return SCCHECK(((ntohs(sh->source) >= info->spts[0])
- && (ntohs(sh->source) <= info->spts[1])),
- XT_SCTP_SRC_PORTS, info->flags, info->invflags)
- && SCCHECK(((ntohs(sh->dest) >= info->dpts[0])
- && (ntohs(sh->dest) <= info->dpts[1])),
+ return SCCHECK(ntohs(sh->source) >= info->spts[0]
+ && ntohs(sh->source) <= info->spts[1],
+ XT_SCTP_SRC_PORTS, info->flags, info->invflags)
+ && SCCHECK(ntohs(sh->dest) >= info->dpts[0]
+ && ntohs(sh->dest) <= info->dpts[1],
XT_SCTP_DEST_PORTS, info->flags, info->invflags)
- && SCCHECK(match_packet(skb, protoff,
- info->chunkmap, info->chunk_match_type,
- info->flag_info, info->flag_count,
- hotdrop),
+ && SCCHECK(match_packet(skb, par->thoff + sizeof(sctp_sctphdr_t),
+ info, par->hotdrop),
XT_SCTP_CHUNK_TYPES, info->flags, info->invflags);
}
-static int
-checkentry(const char *tablename,
- const void *inf,
- const struct xt_match *match,
- void *matchinfo,
- unsigned int matchsize,
- unsigned int hook_mask)
+static bool sctp_mt_check(const struct xt_mtchk_param *par)
{
- const struct xt_sctp_info *info = matchinfo;
+ const struct xt_sctp_info *info = par->matchinfo;
return !(info->flags & ~XT_SCTP_VALID_FLAGS)
&& !(info->invflags & ~XT_SCTP_VALID_FLAGS)
&& !(info->invflags & ~info->flags)
- && ((!(info->flags & XT_SCTP_CHUNK_TYPES)) ||
+ && ((!(info->flags & XT_SCTP_CHUNK_TYPES)) ||
(info->chunk_match_type &
- (SCTP_CHUNK_MATCH_ALL
+ (SCTP_CHUNK_MATCH_ALL
| SCTP_CHUNK_MATCH_ANY
| SCTP_CHUNK_MATCH_ONLY)));
}
-static struct xt_match sctp_match = {
- .name = "sctp",
- .match = match,
- .matchsize = sizeof(struct xt_sctp_info),
- .proto = IPPROTO_SCTP,
- .checkentry = checkentry,
- .me = THIS_MODULE
+static struct xt_match sctp_mt_reg[] __read_mostly = {
+ {
+ .name = "sctp",
+ .family = NFPROTO_IPV4,
+ .checkentry = sctp_mt_check,
+ .match = sctp_mt,
+ .matchsize = sizeof(struct xt_sctp_info),
+ .proto = IPPROTO_SCTP,
+ .me = THIS_MODULE
+ },
+ {
+ .name = "sctp",
+ .family = NFPROTO_IPV6,
+ .checkentry = sctp_mt_check,
+ .match = sctp_mt,
+ .matchsize = sizeof(struct xt_sctp_info),
+ .proto = IPPROTO_SCTP,
+ .me = THIS_MODULE
+ },
};
-static struct xt_match sctp6_match = {
- .name = "sctp",
- .match = match,
- .matchsize = sizeof(struct xt_sctp_info),
- .proto = IPPROTO_SCTP,
- .checkentry = checkentry,
- .me = THIS_MODULE
-};
-
-static int __init init(void)
+static int __init sctp_mt_init(void)
{
- int ret;
- ret = xt_register_match(AF_INET, &sctp_match);
- if (ret)
- return ret;
-
- ret = xt_register_match(AF_INET6, &sctp6_match);
- if (ret)
- xt_unregister_match(AF_INET, &sctp_match);
-
- return ret;
+ return xt_register_matches(sctp_mt_reg, ARRAY_SIZE(sctp_mt_reg));
}
-static void __exit fini(void)
+static void __exit sctp_mt_exit(void)
{
- xt_unregister_match(AF_INET6, &sctp6_match);
- xt_unregister_match(AF_INET, &sctp_match);
+ xt_unregister_matches(sctp_mt_reg, ARRAY_SIZE(sctp_mt_reg));
}
-module_init(init);
-module_exit(fini);
+module_init(sctp_mt_init);
+module_exit(sctp_mt_exit);