#include <linux/module.h>
#include <linux/skbuff.h>
+#include <linux/ip.h>
#include <linux/ipv6.h>
#include <linux/types.h>
#include <net/checksum.h>
static inline int
spi_match(u_int32_t min, u_int32_t max, u_int32_t spi, int invert)
{
- int r=0;
- DEBUGP("ah spi_match:%c 0x%x <= 0x%x <= 0x%x",invert? '!':' ',
- min,spi,max);
- r=(spi >= min && spi <= max) ^ invert;
- DEBUGP(" result %s\n",r? "PASS\n" : "FAILED\n");
- return r;
+ int r=0;
+ DEBUGP("ah spi_match:%c 0x%x <= 0x%x <= 0x%x",invert? '!':' ',
+ min,spi,max);
+ r = (spi >= min && spi <= max) ^ invert;
+ DEBUGP(" result %s\n",r? "PASS\n" : "FAILED\n");
+ return r;
}
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 ip_auth_hdr *ah = NULL;
- const struct ip6t_ah *ahinfo = matchinfo;
- unsigned int temp;
- int len;
- u8 nexthdr;
- unsigned int ptr;
- unsigned int hdrlen = 0;
-
- /*DEBUGP("IPv6 AH entered\n");*/
- /* if (opt->auth == 0) return 0;
- * It does not filled on output */
-
- /* 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_ah 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=(struct ipv6_opt_hdr *)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);
-
- /* AH -> evaluate */
- if (nexthdr == NEXTHDR_AUTH) {
- temp |= MASK_AH;
- 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_ah match: unknown nextheader %u\n",nexthdr);
- return 0;
- break;
- }
-
- nexthdr = hdr->nexthdr;
- len -= hdrlen;
- ptr += hdrlen;
- if ( ptr > skb->len ) {
- DEBUGP("ipv6_ah: new pointer too large! \n");
- break;
- }
- }
-
- /* AH header not found */
- if ( temp != MASK_AH ) return 0;
-
- if (len < (int)sizeof(struct ip_auth_hdr)){
- *hotdrop = 1;
- return 0;
- }
-
- ah = (struct ip_auth_hdr *) (skb->data + ptr);
-
- DEBUGP("IPv6 AH LEN %u %u ", hdrlen, ah->hdrlen);
- DEBUGP("RES %04X ", ah->reserved);
- DEBUGP("SPI %u %08X\n", ntohl(ah->spi), ntohl(ah->spi));
-
- DEBUGP("IPv6 AH spi %02X ",
- (spi_match(ahinfo->spis[0], ahinfo->spis[1],
- ntohl(ah->spi),
- !!(ahinfo->invflags & IP6T_AH_INV_SPI))));
- DEBUGP("len %02X %04X %02X ",
- ahinfo->hdrlen, hdrlen,
- (!ahinfo->hdrlen ||
- (ahinfo->hdrlen == hdrlen) ^
- !!(ahinfo->invflags & IP6T_AH_INV_LEN)));
- DEBUGP("res %02X %04X %02X\n",
- ahinfo->hdrres, ah->reserved,
- !(ahinfo->hdrres && ah->reserved));
-
- return (ah != NULL)
- &&
- (spi_match(ahinfo->spis[0], ahinfo->spis[1],
- ntohl(ah->spi),
- !!(ahinfo->invflags & IP6T_AH_INV_SPI)))
- &&
- (!ahinfo->hdrlen ||
- (ahinfo->hdrlen == hdrlen) ^
- !!(ahinfo->invflags & IP6T_AH_INV_LEN))
- &&
- !(ahinfo->hdrres && ah->reserved);
+ struct ip_auth_hdr *ah, _ah;
+ const struct ip6t_ah *ahinfo = matchinfo;
+ unsigned int ptr;
+ unsigned int hdrlen = 0;
+ int err;
+
+ err = ipv6_find_hdr(skb, &ptr, NEXTHDR_AUTH, NULL);
+ if (err < 0) {
+ if (err != -ENOENT)
+ *hotdrop = 1;
+ return 0;
+ }
+
+ ah = skb_header_pointer(skb, ptr, sizeof(_ah), &_ah);
+ if (ah == NULL) {
+ *hotdrop = 1;
+ return 0;
+ }
+
+ hdrlen = (ah->hdrlen + 2) << 2;
+
+ DEBUGP("IPv6 AH LEN %u %u ", hdrlen, ah->hdrlen);
+ DEBUGP("RES %04X ", ah->reserved);
+ DEBUGP("SPI %u %08X\n", ntohl(ah->spi), ntohl(ah->spi));
+
+ DEBUGP("IPv6 AH spi %02X ",
+ (spi_match(ahinfo->spis[0], ahinfo->spis[1],
+ ntohl(ah->spi),
+ !!(ahinfo->invflags & IP6T_AH_INV_SPI))));
+ DEBUGP("len %02X %04X %02X ",
+ ahinfo->hdrlen, hdrlen,
+ (!ahinfo->hdrlen ||
+ (ahinfo->hdrlen == hdrlen) ^
+ !!(ahinfo->invflags & IP6T_AH_INV_LEN)));
+ DEBUGP("res %02X %04X %02X\n",
+ ahinfo->hdrres, ah->reserved,
+ !(ahinfo->hdrres && ah->reserved));
+
+ return (ah != NULL)
+ &&
+ (spi_match(ahinfo->spis[0], ahinfo->spis[1],
+ ntohl(ah->spi),
+ !!(ahinfo->invflags & IP6T_AH_INV_SPI)))
+ &&
+ (!ahinfo->hdrlen ||
+ (ahinfo->hdrlen == hdrlen) ^
+ !!(ahinfo->invflags & IP6T_AH_INV_LEN))
+ &&
+ !(ahinfo->hdrres && ah->reserved);
}
/* Called when user tries to insert an entry of this type. */
static int
checkentry(const char *tablename,
- const struct ip6t_ip6 *ip,
+ const void *entry,
+ const struct xt_match *match,
void *matchinfo,
- unsigned int matchinfosize,
unsigned int hook_mask)
{
- const struct ip6t_ah *ahinfo = matchinfo;
-
- if (matchinfosize != IP6T_ALIGN(sizeof(struct ip6t_ah))) {
- DEBUGP("ip6t_ah: matchsize %u != %u\n",
- matchinfosize, IP6T_ALIGN(sizeof(struct ip6t_ah)));
- return 0;
- }
- if (ahinfo->invflags & ~IP6T_AH_INV_MASK) {
- DEBUGP("ip6t_ah: unknown flags %X\n",
- ahinfo->invflags);
- return 0;
- }
-
- return 1;
+ const struct ip6t_ah *ahinfo = matchinfo;
+
+ if (ahinfo->invflags & ~IP6T_AH_INV_MASK) {
+ DEBUGP("ip6t_ah: unknown flags %X\n", ahinfo->invflags);
+ return 0;
+ }
+ return 1;
}
static struct ip6t_match ah_match = {
.name = "ah",
- .match = &match,
- .checkentry = &checkentry,
+ .match = match,
+ .matchsize = sizeof(struct ip6t_ah),
+ .checkentry = checkentry,
.me = THIS_MODULE,
};
-static int __init init(void)
+static int __init ip6t_ah_init(void)
{
- return ip6t_register_match(&ah_match);
+ return ip6t_register_match(&ah_match);
}
-static void __exit cleanup(void)
+static void __exit ip6t_ah_fini(void)
{
- ip6t_unregister_match(&ah_match);
+ ip6t_unregister_match(&ah_match);
}
-module_init(init);
-module_exit(cleanup);
+module_init(ip6t_ah_init);
+module_exit(ip6t_ah_fini);