diff options
Diffstat (limited to 'net/ipv6/netfilter/ip6_tables.c')
| -rw-r--r-- | net/ipv6/netfilter/ip6_tables.c | 52 |
1 files changed, 52 insertions, 0 deletions
diff --git a/net/ipv6/netfilter/ip6_tables.c b/net/ipv6/netfilter/ip6_tables.c index 1cb8adb2787fc5..2da514b16d95e7 100644 --- a/net/ipv6/netfilter/ip6_tables.c +++ b/net/ipv6/netfilter/ip6_tables.c @@ -1955,6 +1955,57 @@ static void __exit fini(void) #endif } +/* + * find specified header up to transport protocol header. + * If found target header, the offset to the header is set to *offset + * and return 0. otherwise, return -1. + * + * Notes: - non-1st Fragment Header isn't skipped. + * - ESP header isn't skipped. + * - The target header may be trancated. + */ +int ipv6_find_hdr(const struct sk_buff *skb, unsigned int *offset, u8 target) +{ + unsigned int start = (u8*)(skb->nh.ipv6h + 1) - skb->data; + u8 nexthdr = skb->nh.ipv6h->nexthdr; + unsigned int len = skb->len - start; + + while (nexthdr != target) { + struct ipv6_opt_hdr _hdr, *hp; + unsigned int hdrlen; + + if ((!ipv6_ext_hdr(nexthdr)) || nexthdr == NEXTHDR_NONE) + return -1; + hp = skb_header_pointer(skb, start, sizeof(_hdr), &_hdr); + if (hp == NULL) + return -1; + if (nexthdr == NEXTHDR_FRAGMENT) { + unsigned short _frag_off, *fp; + fp = skb_header_pointer(skb, + start+offsetof(struct frag_hdr, + frag_off), + sizeof(_frag_off), + &_frag_off); + if (fp == NULL) + return -1; + + if (ntohs(*fp) & ~0x7) + return -1; + hdrlen = 8; + } else if (nexthdr == NEXTHDR_AUTH) + hdrlen = (hp->hdrlen + 2) << 2; + else + hdrlen = ipv6_optlen(hp); + + nexthdr = hp->nexthdr; + len -= hdrlen; + start += hdrlen; + } + + *offset = start; + return 0; +} + EXPORT_SYMBOL(ip6t_register_table); EXPORT_SYMBOL(ip6t_unregister_table); EXPORT_SYMBOL(ip6t_do_table); @@ -1963,6 +2014,7 @@ EXPORT_SYMBOL(ip6t_unregister_match); EXPORT_SYMBOL(ip6t_register_target); EXPORT_SYMBOL(ip6t_unregister_target); EXPORT_SYMBOL(ip6t_ext_hdr); +EXPORT_SYMBOL(ipv6_find_hdr); module_init(init); module_exit(fini); |