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author | Balazs Scheidler <bazsi@balabit.hu> | 2010-10-21 16:19:42 +0200 |
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committer | Patrick McHardy <kaber@trash.net> | 2010-10-21 16:19:42 +0200 |
commit | b64c9256a9b76fc9f059f71bd08ba88fb0cbba2e (patch) | |
tree | 73ee45920aa05b8800b1eb468a6f34ddb71273fe /net | |
parent | 6ad7889327a5ee6ab4220bd34e4428c7d0de0f32 (diff) | |
download | lwn-b64c9256a9b76fc9f059f71bd08ba88fb0cbba2e.tar.gz lwn-b64c9256a9b76fc9f059f71bd08ba88fb0cbba2e.zip |
tproxy: added IPv6 support to the socket match
The ICMP extraction bits were contributed by Harry Mason.
Signed-off-by: Balazs Scheidler <bazsi@balabit.hu>
Signed-off-by: KOVACS Krisztian <hidden@balabit.hu>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Diffstat (limited to 'net')
-rw-r--r-- | net/netfilter/xt_socket.c | 165 |
1 files changed, 154 insertions, 11 deletions
diff --git a/net/netfilter/xt_socket.c b/net/netfilter/xt_socket.c index 266faa0a2fbf..2dbd4c857735 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, @@ -86,7 +88,6 @@ extract_icmp_fields(const struct sk_buff *skb, return 0; } - static bool socket_match(const struct sk_buff *skb, struct xt_action_param *par, const struct xt_socket_mtinfo1 *info) @@ -115,7 +116,7 @@ socket_match(const struct sk_buff *skb, struct xt_action_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 { @@ -165,32 +166,157 @@ socket_match(const struct sk_buff *skb, struct xt_action_param *par, sk = NULL; } - pr_debug("proto %u %08x:%u -> %08x:%u (orig %08x:%u) sock %p\n", - protocol, ntohl(saddr), ntohs(sport), - ntohl(daddr), ntohs(dport), - ntohl(iph->daddr), hp ? ntohs(hp->dest) : 0, sk); + pr_debug("proto %hhu %pI4:%hu -> %pI4:%hu (orig %pI4:%hu) sock %p\n", + protocol, &saddr, ntohs(sport), + &daddr, ntohs(dport), + &iph->daddr, hp ? ntohs(hp->dest) : 0, sk); return (sk != NULL); } static bool -socket_mt_v0(const struct sk_buff *skb, struct xt_action_param *par) +socket_mt4_v0(const struct sk_buff *skb, struct xt_action_param *par) { return socket_match(skb, par, NULL); } static bool -socket_mt_v1(const struct sk_buff *skb, struct xt_action_param *par) +socket_mt4_v1(const struct sk_buff *skb, struct xt_action_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, + unsigned int outside_hdrlen, + u8 *protocol, + struct in6_addr **raddr, + struct in6_addr **laddr, + __be16 *rport, + __be16 *lport) +{ + struct ipv6hdr *inside_iph, _inside_iph; + struct icmp6hdr *icmph, _icmph; + __be16 *ports, _ports[2]; + u8 inside_nexthdr; + int inside_hdrlen; + + icmph = skb_header_pointer(skb, outside_hdrlen, + sizeof(_icmph), &_icmph); + if (icmph == NULL) + return 1; + + if (icmph->icmp6_type & ICMPV6_INFOMSG_MASK) + return 1; + + inside_iph = skb_header_pointer(skb, outside_hdrlen + sizeof(_icmph), sizeof(_inside_iph), &_inside_iph); + if (inside_iph == NULL) + return 1; + inside_nexthdr = inside_iph->nexthdr; + + inside_hdrlen = ipv6_skip_exthdr(skb, outside_hdrlen + sizeof(_icmph) + sizeof(_inside_iph), &inside_nexthdr); + if (inside_hdrlen < 0) + return 1; /* hjm: Packet has no/incomplete transport layer headers. */ + + if (inside_nexthdr != IPPROTO_TCP && + inside_nexthdr != IPPROTO_UDP) + return 1; + + ports = skb_header_pointer(skb, inside_hdrlen, + sizeof(_ports), &_ports); + if (ports == NULL) + return 1; + + /* the inside IP packet is the one quoted from our side, thus + * its saddr is the local address */ + *protocol = inside_nexthdr; + *laddr = &inside_iph->saddr; + *lport = ports[0]; + *raddr = &inside_iph->daddr; + *rport = ports[1]; + + return 0; +} + +static bool +socket_mt6_v1(const struct sk_buff *skb, struct xt_action_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("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_ICMPV6) { + if (extract_icmp6_fields(skb, thoff, &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("proto %hhu %pI6:%hu -> %pI6:%hu " + "(orig %pI6:%hu) 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) | (1 << NF_INET_LOCAL_IN), .me = THIS_MODULE, @@ -199,17 +325,33 @@ 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) | (1 << NF_INET_LOCAL_IN), .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) | + (1 << NF_INET_LOCAL_IN), + .me = THIS_MODULE, + }, +#endif }; static int __init socket_mt_init(void) { nf_defrag_ipv4_enable(); +#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) + nf_defrag_ipv6_enable(); +#endif + return xt_register_matches(socket_mt_reg, ARRAY_SIZE(socket_mt_reg)); } @@ -225,3 +367,4 @@ MODULE_LICENSE("GPL"); MODULE_AUTHOR("Krisztian Kovacs, Balazs Scheidler"); MODULE_DESCRIPTION("x_tables socket match module"); MODULE_ALIAS("ipt_socket"); +MODULE_ALIAS("ip6t_socket"); |