#include <linux/netfilter_ipv6/ip6_tables.h>
#include <linux/netfilter_ipv6/ip6t_opts.h>
-#define LOW(n) (n & 0x00FF)
-
-#define HOPBYHOP 1
-
MODULE_LICENSE("GPL");
-#if HOPBYHOP
-MODULE_DESCRIPTION("IPv6 HbH match");
-#else
-MODULE_DESCRIPTION("IPv6 DST match");
-#endif
+MODULE_DESCRIPTION("IPv6 opts match");
MODULE_AUTHOR("Andras Kis-Szabo <kisza@sch.bme.hu>");
+MODULE_ALIAS("ip6t_dst");
#if 0
#define DEBUGP printk
#endif
/*
- * (Type & 0xC0) >> 6
- * 0 -> ignorable
- * 1 -> must drop the packet
- * 2 -> send ICMP PARM PROB regardless and drop packet
- * 3 -> Send ICMP if not a multicast address and drop packet
+ * (Type & 0xC0) >> 6
+ * 0 -> ignorable
+ * 1 -> must drop the packet
+ * 2 -> send ICMP PARM PROB regardless and drop packet
+ * 3 -> Send ICMP if not a multicast address and drop packet
* (Type & 0x20) >> 5
- * 0 -> invariant
- * 1 -> can change the routing
+ * 0 -> invariant
+ * 1 -> can change the routing
* (Type & 0x1F) Type
- * 0 -> PAD0 (only 1 byte!)
- * 1 -> PAD1 LENGTH info (total length = length + 2)
- * C0 | 2 -> JUMBO 4 x x x x ( xxxx > 64k )
- * 5 -> RTALERT 2 x x
+ * 0 -> Pad1 (only 1 byte!)
+ * 1 -> PadN LENGTH info (total length = length + 2)
+ * C0 | 2 -> JUMBO 4 x x x x ( xxxx > 64k )
+ * 5 -> RTALERT 2 x x
*/
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,
- const void *protohdr,
- u_int16_t datalen,
+ unsigned int protoff,
int *hotdrop)
{
- struct ipv6_opt_hdr *optsh = NULL;
- const struct ip6t_opts *optinfo = matchinfo;
- unsigned int temp;
- unsigned int len;
- u8 nexthdr;
- unsigned int ptr;
- unsigned int hdrlen = 0;
- unsigned int ret = 0;
- u_int16_t *optdesc = NULL;
-
- /* type of the 1st exthdr */
- nexthdr = skb->nh.ipv6h->nexthdr;
- /* pointer to the 1st exthdr */
- ptr = sizeof(struct ipv6hdr);
- /* available length */
- len = skb->len - ptr;
- temp = 0;
-
- while (ip6t_ext_hdr(nexthdr)) {
- struct ipv6_opt_hdr *hdr;
-
- DEBUGP("ipv6_opts header iteration \n");
-
- /* Is there enough space for the next ext header? */
- if (len < (int)sizeof(struct ipv6_opt_hdr))
- return 0;
- /* No more exthdr -> evaluate */
- if (nexthdr == NEXTHDR_NONE) {
- break;
- }
- /* ESP -> evaluate */
- if (nexthdr == NEXTHDR_ESP) {
- break;
- }
-
- hdr=(void *)(skb->data)+ptr;
-
- /* Calculate the header length */
- if (nexthdr == NEXTHDR_FRAGMENT) {
- hdrlen = 8;
- } else if (nexthdr == NEXTHDR_AUTH)
- hdrlen = (hdr->hdrlen+2)<<2;
- else
- hdrlen = ipv6_optlen(hdr);
-
- /* OPTS -> evaluate */
-#if HOPBYHOP
- if (nexthdr == NEXTHDR_HOP) {
- temp |= MASK_HOPOPTS;
-#else
- if (nexthdr == NEXTHDR_DEST) {
- temp |= MASK_DSTOPTS;
-#endif
- break;
- }
-
-
- /* set the flag */
- switch (nexthdr){
- case NEXTHDR_HOP:
- case NEXTHDR_ROUTING:
- case NEXTHDR_FRAGMENT:
- case NEXTHDR_AUTH:
- case NEXTHDR_DEST:
- break;
- default:
- DEBUGP("ipv6_opts match: unknown nextheader %u\n",nexthdr);
- return 0;
- break;
- }
-
- nexthdr = hdr->nexthdr;
- len -= hdrlen;
- ptr += hdrlen;
- if ( ptr > skb->len ) {
- DEBUGP("ipv6_opts: new pointer is too large! \n");
- break;
- }
- }
-
- /* OPTIONS header not found */
-#if HOPBYHOP
- if ( temp != MASK_HOPOPTS ) return 0;
-#else
- if ( temp != MASK_DSTOPTS ) return 0;
-#endif
-
- if (len < (int)sizeof(struct ipv6_opt_hdr)){
- *hotdrop = 1;
- return 0;
- }
+ struct ipv6_opt_hdr _optsh, *oh;
+ const struct ip6t_opts *optinfo = matchinfo;
+ unsigned int temp;
+ unsigned int ptr;
+ unsigned int hdrlen = 0;
+ unsigned int ret = 0;
+ u8 _opttype, *tp = NULL;
+ u8 _optlen, *lp = NULL;
+ unsigned int optlen;
+ int err;
+
+ err = ipv6_find_hdr(skb, &ptr, match->data, NULL);
+ if (err < 0) {
+ if (err != -ENOENT)
+ *hotdrop = 1;
+ return 0;
+ }
- if (len < hdrlen){
- /* Packet smaller than it's length field */
- return 0;
- }
+ oh = skb_header_pointer(skb, ptr, sizeof(_optsh), &_optsh);
+ if (oh == NULL) {
+ *hotdrop = 1;
+ return 0;
+ }
- optsh=(void *)(skb->data)+ptr;
+ hdrlen = ipv6_optlen(oh);
+ if (skb->len - ptr < hdrlen) {
+ /* Packet smaller than it's length field */
+ return 0;
+ }
- DEBUGP("IPv6 OPTS LEN %u %u ", hdrlen, optsh->hdrlen);
+ DEBUGP("IPv6 OPTS LEN %u %u ", hdrlen, oh->hdrlen);
- DEBUGP("len %02X %04X %02X ",
- optinfo->hdrlen, hdrlen,
- (!(optinfo->flags & IP6T_OPTS_LEN) ||
- ((optinfo->hdrlen == hdrlen) ^
- !!(optinfo->invflags & IP6T_OPTS_INV_LEN))));
+ DEBUGP("len %02X %04X %02X ",
+ optinfo->hdrlen, hdrlen,
+ (!(optinfo->flags & IP6T_OPTS_LEN) ||
+ ((optinfo->hdrlen == hdrlen) ^
+ !!(optinfo->invflags & IP6T_OPTS_INV_LEN))));
- ret = (optsh != NULL)
- &&
- (!(optinfo->flags & IP6T_OPTS_LEN) ||
- ((optinfo->hdrlen == hdrlen) ^
- !!(optinfo->invflags & IP6T_OPTS_INV_LEN)));
+ ret = (oh != NULL) &&
+ (!(optinfo->flags & IP6T_OPTS_LEN) ||
+ ((optinfo->hdrlen == hdrlen) ^
+ !!(optinfo->invflags & IP6T_OPTS_INV_LEN)));
- temp = len = 0;
- ptr += 2;
- hdrlen -= 2;
- if ( !(optinfo->flags & IP6T_OPTS_OPTS) ){
- return ret;
+ ptr += 2;
+ hdrlen -= 2;
+ if (!(optinfo->flags & IP6T_OPTS_OPTS)) {
+ return ret;
} else if (optinfo->flags & IP6T_OPTS_NSTRICT) {
DEBUGP("Not strict - not implemented");
} else {
DEBUGP("Strict ");
- DEBUGP("#%d ",optinfo->optsnr);
- for(temp=0; temp<optinfo->optsnr; temp++){
- optdesc = (void *)(skb->data)+ptr;
+ DEBUGP("#%d ", optinfo->optsnr);
+ for (temp = 0; temp < optinfo->optsnr; temp++) {
+ /* type field exists ? */
+ if (hdrlen < 1)
+ break;
+ tp = skb_header_pointer(skb, ptr, sizeof(_opttype),
+ &_opttype);
+ if (tp == NULL)
+ break;
+
/* Type check */
- if ( (unsigned char)*optdesc !=
- (optinfo->opts[temp] & 0xFF00)>>8 ){
+ if (*tp != (optinfo->opts[temp] & 0xFF00) >> 8) {
DEBUGP("Tbad %02X %02X\n",
- (unsigned char)*optdesc,
- (optinfo->opts[temp] &
- 0xFF00)>>8);
+ *tp,
+ (optinfo->opts[temp] & 0xFF00) >> 8);
return 0;
} else {
DEBUGP("Tok ");
}
/* Length check */
- if (((optinfo->opts[temp] & 0x00FF) != 0xFF) &&
- (unsigned char)*optdesc != 0){
- if ( ntohs((u16)*optdesc) !=
- optinfo->opts[temp] ){
- DEBUGP("Lbad %02X %04X %04X\n",
- (unsigned char)*optdesc,
- ntohs((u16)*optdesc),
- optinfo->opts[temp]);
+ if (*tp) {
+ u16 spec_len;
+
+ /* length field exists ? */
+ if (hdrlen < 2)
+ break;
+ lp = skb_header_pointer(skb, ptr + 1,
+ sizeof(_optlen),
+ &_optlen);
+ if (lp == NULL)
+ break;
+ spec_len = optinfo->opts[temp] & 0x00FF;
+
+ if (spec_len != 0x00FF && spec_len != *lp) {
+ DEBUGP("Lbad %02X %04X\n", *lp,
+ spec_len);
return 0;
- } else {
- DEBUGP("Lok ");
}
- }
- /* Step to the next */
- if ((unsigned char)*optdesc == 0){
- DEBUGP("PAD0 \n");
- ptr++;
- hdrlen--;
+ DEBUGP("Lok ");
+ optlen = *lp + 2;
} else {
- ptr += LOW(ntohs(*optdesc));
- hdrlen -= LOW(ntohs(*optdesc));
- DEBUGP("len%04X \n",
- LOW(ntohs(*optdesc)));
+ DEBUGP("Pad1\n");
+ optlen = 1;
}
- if (ptr > skb->len || ( !hdrlen &&
- (temp != optinfo->optsnr - 1))) {
+
+ /* Step to the next */
+ DEBUGP("len%04X \n", optlen);
+
+ if ((ptr > skb->len - optlen || hdrlen < optlen) &&
+ (temp < optinfo->optsnr - 1)) {
DEBUGP("new pointer is too large! \n");
break;
}
+ ptr += optlen;
+ hdrlen -= optlen;
}
if (temp == optinfo->optsnr)
return ret;
- else return 0;
+ else
+ return 0;
}
return 0;
/* Called when user tries to insert an entry of this type. */
static int
checkentry(const char *tablename,
- const struct ip6t_ip6 *ip,
- void *matchinfo,
- unsigned int matchinfosize,
- unsigned int hook_mask)
+ const void *entry,
+ const struct xt_match *match,
+ void *matchinfo,
+ unsigned int hook_mask)
{
- const struct ip6t_opts *optsinfo = matchinfo;
+ const struct ip6t_opts *optsinfo = matchinfo;
- if (matchinfosize != IP6T_ALIGN(sizeof(struct ip6t_opts))) {
- DEBUGP("ip6t_opts: matchsize %u != %u\n",
- matchinfosize, IP6T_ALIGN(sizeof(struct ip6t_opts)));
- return 0;
- }
- if (optsinfo->invflags & ~IP6T_OPTS_INV_MASK) {
- DEBUGP("ip6t_opts: unknown flags %X\n",
- optsinfo->invflags);
- return 0;
- }
-
- return 1;
+ if (optsinfo->invflags & ~IP6T_OPTS_INV_MASK) {
+ DEBUGP("ip6t_opts: unknown flags %X\n", optsinfo->invflags);
+ return 0;
+ }
+ return 1;
}
-static struct ip6t_match opts_match = {
-#if HOPBYHOP
- .name = "hbh",
-#else
- .name = "dst",
-#endif
- .match = &match,
- .checkentry = &checkentry,
- .me = THIS_MODULE,
+static struct xt_match opts_match[] = {
+ {
+ .name = "hbh",
+ .family = AF_INET6,
+ .match = match,
+ .matchsize = sizeof(struct ip6t_opts),
+ .checkentry = checkentry,
+ .me = THIS_MODULE,
+ .data = NEXTHDR_HOP,
+ },
+ {
+ .name = "dst",
+ .family = AF_INET6,
+ .match = match,
+ .matchsize = sizeof(struct ip6t_opts),
+ .checkentry = checkentry,
+ .me = THIS_MODULE,
+ .data = NEXTHDR_DEST,
+ },
};
-static int __init init(void)
+static int __init ip6t_hbh_init(void)
{
- return ip6t_register_match(&opts_match);
+ return xt_register_matches(opts_match, ARRAY_SIZE(opts_match));
}
-static void __exit cleanup(void)
+static void __exit ip6t_hbh_fini(void)
{
- ip6t_unregister_match(&opts_match);
+ xt_unregister_matches(opts_match, ARRAY_SIZE(opts_match));
}
-module_init(init);
-module_exit(cleanup);
+module_init(ip6t_hbh_init);
+module_exit(ip6t_hbh_fini);