Signed-off-by: Balazs Scheidler <bazsi@balabit.hu> --- net/netfilter/xt_socket.c | 111 ++++++++++++++++++++++++++++++++++++++++++--- 1 files changed, 105 insertions(+), 6 deletions(-) diff --git a/net/netfilter/xt_socket.c b/net/netfilter/xt_socket.c index 12a7140..41a8383 100644 --- a/net/netfilter/xt_socket.c +++ b/net/netfilter/xt_socket.c @@ -14,6 +14,7 @@ #include <linux/skbuff.h> #include <linux/netfilter/x_tables.h> #include <linux/netfilter_ipv4/ip_tables.h> +#include <linux/netfilter_ipv6/ip6_tables.h> #include <net/tcp.h> #include <net/udp.h> #include <net/icmp.h> @@ -21,6 +22,7 @@ #include <net/inet_sock.h> #include <net/netfilter/nf_tproxy_core.h> #include <net/netfilter/ipv4/nf_defrag_ipv4.h> +#include <net/netfilter/ipv6/nf_defrag_ipv6.h> #include <linux/netfilter/xt_socket.h> @@ -30,7 +32,7 @@ #endif static int -extract_icmp_fields(const struct sk_buff *skb, +extract_icmp4_fields(const struct sk_buff *skb, u8 *protocol, __be32 *raddr, __be32 *laddr, @@ -115,7 +117,7 @@ socket_match(const struct sk_buff *skb, const struct xt_match_param *par, dport = hp->dest; } else if (iph->protocol == IPPROTO_ICMP) { - if (extract_icmp_fields(skb, &protocol, &saddr, &daddr, + if (extract_icmp4_fields(skb, &protocol, &saddr, &daddr, &sport, &dport)) return false; } else { @@ -175,23 +177,107 @@ socket_match(const struct sk_buff *skb, const struct xt_match_param *par, } static bool -socket_mt_v0(const struct sk_buff *skb, const struct xt_match_param *par) +socket_mt4_v0(const struct sk_buff *skb, const struct xt_match_param *par) { return socket_match(skb, par, NULL); } static bool -socket_mt_v1(const struct sk_buff *skb, const struct xt_match_param *par) +socket_mt4_v1(const struct sk_buff *skb, const struct xt_match_param *par) { return socket_match(skb, par, par->matchinfo); } +#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) + +static int +extract_icmp6_fields(const struct sk_buff *skb, + u8 *protocol, + struct in6_addr **raddr, + struct in6_addr **laddr, + __be16 *rport, + __be16 *lport) +{ + return 1; +} + +static bool +socket_mt6_v1(const struct sk_buff *skb, const struct xt_match_param *par) +{ + struct ipv6hdr *iph = ipv6_hdr(skb); + struct udphdr _hdr, *hp = NULL; + struct sock *sk; + struct in6_addr *daddr, *saddr; + __be16 dport, sport; + int thoff; + u8 tproto; + const struct xt_socket_mtinfo1 *info = (struct xt_socket_mtinfo1 *) par->matchinfo; + + tproto = ipv6_find_hdr(skb, &thoff, -1, NULL); + if (tproto < 0) { + pr_debug("socket match: Unable to find transport header in IPv6 packet, dropping\n"); + return NF_DROP; + } + + if (tproto == IPPROTO_UDP || tproto == IPPROTO_TCP) { + hp = skb_header_pointer(skb, thoff, + sizeof(_hdr), &_hdr); + if (hp == NULL) + return false; + + saddr = &iph->saddr; + sport = hp->source; + daddr = &iph->daddr; + dport = hp->dest; + + } else if (tproto == IPPROTO_ICMP) { + if (extract_icmp6_fields(skb, &tproto, &saddr, &daddr, + &sport, &dport)) + return false; + } else { + return false; + } + + sk = nf_tproxy_get_sock_v6(dev_net(skb->dev), tproto, + saddr, daddr, sport, dport, par->in, NFT_LOOKUP_ANY); + if (sk != NULL) { + bool wildcard; + bool transparent = true; + + /* Ignore sockets listening on INADDR_ANY */ + wildcard = (sk->sk_state != TCP_TIME_WAIT && + ipv6_addr_any(&inet6_sk(sk)->rcv_saddr)); + + /* Ignore non-transparent sockets, + if XT_SOCKET_TRANSPARENT is used */ + if (info && info->flags & XT_SOCKET_TRANSPARENT) + transparent = ((sk->sk_state != TCP_TIME_WAIT && + inet_sk(sk)->transparent) || + (sk->sk_state == TCP_TIME_WAIT && + inet_twsk(sk)->tw_transparent)); + + nf_tproxy_put_sock(sk); + + if (wildcard || !transparent) + sk = NULL; + } + + pr_debug("socket match: proto %u %pI6:%u -> %pI6:%u " + "(orig %pI6:%u) sock %p\n", + tproto, saddr, ntohs(sport), + daddr, ntohs(dport), + &iph->daddr, hp ? ntohs(hp->dest) : 0, sk); + + return (sk != NULL); +} +#endif + static struct xt_match socket_mt_reg[] __read_mostly = { { .name = "socket", .revision = 0, .family = NFPROTO_IPV4, - .match = socket_mt_v0, + .match = socket_mt4_v0, .hooks = 1 << NF_INET_PRE_ROUTING, .me = THIS_MODULE, }, @@ -199,16 +285,28 @@ static struct xt_match socket_mt_reg[] __read_mostly = { .name = "socket", .revision = 1, .family = NFPROTO_IPV4, - .match = socket_mt_v1, + .match = socket_mt4_v1, + .matchsize = sizeof(struct xt_socket_mtinfo1), + .hooks = 1 << NF_INET_PRE_ROUTING, + .me = THIS_MODULE, + }, +#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) + { + .name = "socket", + .revision = 1, + .family = NFPROTO_IPV6, + .match = socket_mt6_v1, .matchsize = sizeof(struct xt_socket_mtinfo1), .hooks = 1 << NF_INET_PRE_ROUTING, .me = THIS_MODULE, }, +#endif }; static int __init socket_mt_init(void) { nf_defrag_ipv4_enable(); + nf_defrag_ipv6_enable(); return xt_register_matches(socket_mt_reg, ARRAY_SIZE(socket_mt_reg)); } @@ -224,3 +322,4 @@ MODULE_LICENSE("GPL"); MODULE_AUTHOR("Krisztian Kovacs, Balazs Scheidler"); MODULE_DESCRIPTION("x_tables socket match module"); MODULE_ALIAS("ipt_socket"); +MODULE_ALIAS("ip6t_socket"); -- 1.6.0.4