diff options
Diffstat (limited to 'net/ipv6/output_core.c')
| -rw-r--r-- | net/ipv6/output_core.c | 31 |
1 files changed, 31 insertions, 0 deletions
diff --git a/net/ipv6/output_core.c b/net/ipv6/output_core.c index 4a7e5ffa5108..4fe7c90962dd 100644 --- a/net/ipv6/output_core.c +++ b/net/ipv6/output_core.c @@ -31,6 +31,37 @@ static u32 __ipv6_select_ident(struct net *net, u32 hashrnd, return id; } +/* This function exists only for tap drivers that must support broken + * clients requesting UFO without specifying an IPv6 fragment ID. + * + * This is similar to ipv6_select_ident() but we use an independent hash + * seed to limit information leakage. + * + * The network header must be set before calling this. + */ +__be32 ipv6_proxy_select_ident(struct net *net, struct sk_buff *skb) +{ + static u32 ip6_proxy_idents_hashrnd __read_mostly; + struct in6_addr buf[2]; + struct in6_addr *addrs; + u32 id; + + addrs = skb_header_pointer(skb, + skb_network_offset(skb) + + offsetof(struct ipv6hdr, saddr), + sizeof(buf), buf); + if (!addrs) + return 0; + + net_get_random_once(&ip6_proxy_idents_hashrnd, + sizeof(ip6_proxy_idents_hashrnd)); + + id = __ipv6_select_ident(net, ip6_proxy_idents_hashrnd, + &addrs[1], &addrs[0]); + return htonl(id); +} +EXPORT_SYMBOL_GPL(ipv6_proxy_select_ident); + __be32 ipv6_select_ident(struct net *net, const struct in6_addr *daddr, const struct in6_addr *saddr) |