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![Daniel Borkmann](/assets/img/avatar_default.png)
This patch replaces the zone id which is pushed down into functions with the actual zone object. It's a bigger one-time change, but needed for later on extending zones with a direction parameter, and thus decoupling this additional information from all call-sites. No functional changes in this patch. The default zone becomes a global const object, namely nf_ct_zone_dflt and will be returned directly in various cases, one being, when there's f.e. no zoning support. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
471 lines
13 KiB
C
471 lines
13 KiB
C
/*
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* Copyright (C)2004 USAGI/WIDE Project
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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* Author:
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* Yasuyuki Kozakai @USAGI <yasuyuki.kozakai@toshiba.co.jp>
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*/
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#include <linux/types.h>
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#include <linux/ipv6.h>
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#include <linux/in6.h>
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#include <linux/netfilter.h>
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#include <linux/module.h>
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#include <linux/skbuff.h>
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#include <linux/icmp.h>
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#include <net/ipv6.h>
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#include <net/inet_frag.h>
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#include <linux/netfilter_bridge.h>
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#include <linux/netfilter_ipv6.h>
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#include <linux/netfilter_ipv6/ip6_tables.h>
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#include <net/netfilter/nf_conntrack.h>
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#include <net/netfilter/nf_conntrack_helper.h>
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#include <net/netfilter/nf_conntrack_l4proto.h>
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#include <net/netfilter/nf_conntrack_l3proto.h>
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#include <net/netfilter/nf_conntrack_core.h>
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#include <net/netfilter/nf_conntrack_zones.h>
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#include <net/netfilter/nf_conntrack_seqadj.h>
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#include <net/netfilter/ipv6/nf_conntrack_ipv6.h>
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#include <net/netfilter/nf_nat_helper.h>
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#include <net/netfilter/ipv6/nf_defrag_ipv6.h>
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#include <net/netfilter/nf_log.h>
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static bool ipv6_pkt_to_tuple(const struct sk_buff *skb, unsigned int nhoff,
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struct nf_conntrack_tuple *tuple)
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{
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const u_int32_t *ap;
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u_int32_t _addrs[8];
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ap = skb_header_pointer(skb, nhoff + offsetof(struct ipv6hdr, saddr),
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sizeof(_addrs), _addrs);
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if (ap == NULL)
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return false;
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memcpy(tuple->src.u3.ip6, ap, sizeof(tuple->src.u3.ip6));
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memcpy(tuple->dst.u3.ip6, ap + 4, sizeof(tuple->dst.u3.ip6));
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return true;
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}
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static bool ipv6_invert_tuple(struct nf_conntrack_tuple *tuple,
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const struct nf_conntrack_tuple *orig)
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{
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memcpy(tuple->src.u3.ip6, orig->dst.u3.ip6, sizeof(tuple->src.u3.ip6));
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memcpy(tuple->dst.u3.ip6, orig->src.u3.ip6, sizeof(tuple->dst.u3.ip6));
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return true;
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}
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static void ipv6_print_tuple(struct seq_file *s,
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const struct nf_conntrack_tuple *tuple)
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{
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seq_printf(s, "src=%pI6 dst=%pI6 ",
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tuple->src.u3.ip6, tuple->dst.u3.ip6);
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}
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static int ipv6_get_l4proto(const struct sk_buff *skb, unsigned int nhoff,
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unsigned int *dataoff, u_int8_t *protonum)
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{
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unsigned int extoff = nhoff + sizeof(struct ipv6hdr);
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__be16 frag_off;
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int protoff;
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u8 nexthdr;
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if (skb_copy_bits(skb, nhoff + offsetof(struct ipv6hdr, nexthdr),
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&nexthdr, sizeof(nexthdr)) != 0) {
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pr_debug("ip6_conntrack_core: can't get nexthdr\n");
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return -NF_ACCEPT;
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}
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protoff = ipv6_skip_exthdr(skb, extoff, &nexthdr, &frag_off);
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/*
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* (protoff == skb->len) means the packet has not data, just
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* IPv6 and possibly extensions headers, but it is tracked anyway
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*/
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if (protoff < 0 || (frag_off & htons(~0x7)) != 0) {
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pr_debug("ip6_conntrack_core: can't find proto in pkt\n");
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return -NF_ACCEPT;
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}
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*dataoff = protoff;
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*protonum = nexthdr;
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return NF_ACCEPT;
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}
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static unsigned int ipv6_helper(const struct nf_hook_ops *ops,
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struct sk_buff *skb,
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const struct nf_hook_state *state)
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{
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struct nf_conn *ct;
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const struct nf_conn_help *help;
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const struct nf_conntrack_helper *helper;
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enum ip_conntrack_info ctinfo;
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__be16 frag_off;
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int protoff;
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u8 nexthdr;
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/* This is where we call the helper: as the packet goes out. */
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ct = nf_ct_get(skb, &ctinfo);
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if (!ct || ctinfo == IP_CT_RELATED_REPLY)
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return NF_ACCEPT;
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help = nfct_help(ct);
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if (!help)
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return NF_ACCEPT;
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/* rcu_read_lock()ed by nf_hook_slow */
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helper = rcu_dereference(help->helper);
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if (!helper)
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return NF_ACCEPT;
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nexthdr = ipv6_hdr(skb)->nexthdr;
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protoff = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), &nexthdr,
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&frag_off);
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if (protoff < 0 || (frag_off & htons(~0x7)) != 0) {
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pr_debug("proto header not found\n");
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return NF_ACCEPT;
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}
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return helper->help(skb, protoff, ct, ctinfo);
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}
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static unsigned int ipv6_confirm(const struct nf_hook_ops *ops,
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struct sk_buff *skb,
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const struct nf_hook_state *state)
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{
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struct nf_conn *ct;
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enum ip_conntrack_info ctinfo;
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unsigned char pnum = ipv6_hdr(skb)->nexthdr;
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int protoff;
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__be16 frag_off;
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ct = nf_ct_get(skb, &ctinfo);
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if (!ct || ctinfo == IP_CT_RELATED_REPLY)
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goto out;
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protoff = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), &pnum,
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&frag_off);
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if (protoff < 0 || (frag_off & htons(~0x7)) != 0) {
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pr_debug("proto header not found\n");
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goto out;
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}
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/* adjust seqs for loopback traffic only in outgoing direction */
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if (test_bit(IPS_SEQ_ADJUST_BIT, &ct->status) &&
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!nf_is_loopback_packet(skb)) {
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if (!nf_ct_seq_adjust(skb, ct, ctinfo, protoff)) {
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NF_CT_STAT_INC_ATOMIC(nf_ct_net(ct), drop);
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return NF_DROP;
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}
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}
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out:
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/* We've seen it coming out the other side: confirm it */
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return nf_conntrack_confirm(skb);
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}
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static unsigned int ipv6_conntrack_in(const struct nf_hook_ops *ops,
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struct sk_buff *skb,
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const struct nf_hook_state *state)
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{
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return nf_conntrack_in(dev_net(state->in), PF_INET6, ops->hooknum, skb);
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}
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static unsigned int ipv6_conntrack_local(const struct nf_hook_ops *ops,
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struct sk_buff *skb,
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const struct nf_hook_state *state)
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{
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/* root is playing with raw sockets. */
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if (skb->len < sizeof(struct ipv6hdr)) {
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net_notice_ratelimited("ipv6_conntrack_local: packet too short\n");
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return NF_ACCEPT;
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}
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return nf_conntrack_in(dev_net(state->out), PF_INET6, ops->hooknum, skb);
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}
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static struct nf_hook_ops ipv6_conntrack_ops[] __read_mostly = {
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{
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.hook = ipv6_conntrack_in,
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.owner = THIS_MODULE,
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.pf = NFPROTO_IPV6,
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.hooknum = NF_INET_PRE_ROUTING,
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.priority = NF_IP6_PRI_CONNTRACK,
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},
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{
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.hook = ipv6_conntrack_local,
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.owner = THIS_MODULE,
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.pf = NFPROTO_IPV6,
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.hooknum = NF_INET_LOCAL_OUT,
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.priority = NF_IP6_PRI_CONNTRACK,
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},
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{
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.hook = ipv6_helper,
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.owner = THIS_MODULE,
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.pf = NFPROTO_IPV6,
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.hooknum = NF_INET_POST_ROUTING,
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.priority = NF_IP6_PRI_CONNTRACK_HELPER,
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},
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{
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.hook = ipv6_confirm,
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.owner = THIS_MODULE,
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.pf = NFPROTO_IPV6,
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.hooknum = NF_INET_POST_ROUTING,
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.priority = NF_IP6_PRI_LAST,
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},
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{
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.hook = ipv6_helper,
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.owner = THIS_MODULE,
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.pf = NFPROTO_IPV6,
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.hooknum = NF_INET_LOCAL_IN,
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.priority = NF_IP6_PRI_CONNTRACK_HELPER,
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},
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{
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.hook = ipv6_confirm,
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.owner = THIS_MODULE,
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.pf = NFPROTO_IPV6,
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.hooknum = NF_INET_LOCAL_IN,
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.priority = NF_IP6_PRI_LAST-1,
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},
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};
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static int
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ipv6_getorigdst(struct sock *sk, int optval, void __user *user, int *len)
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{
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const struct inet_sock *inet = inet_sk(sk);
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const struct ipv6_pinfo *inet6 = inet6_sk(sk);
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const struct nf_conntrack_tuple_hash *h;
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struct sockaddr_in6 sin6;
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struct nf_conntrack_tuple tuple = { .src.l3num = NFPROTO_IPV6 };
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struct nf_conn *ct;
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tuple.src.u3.in6 = sk->sk_v6_rcv_saddr;
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tuple.src.u.tcp.port = inet->inet_sport;
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tuple.dst.u3.in6 = sk->sk_v6_daddr;
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tuple.dst.u.tcp.port = inet->inet_dport;
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tuple.dst.protonum = sk->sk_protocol;
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if (sk->sk_protocol != IPPROTO_TCP && sk->sk_protocol != IPPROTO_SCTP)
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return -ENOPROTOOPT;
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if (*len < 0 || (unsigned int) *len < sizeof(sin6))
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return -EINVAL;
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h = nf_conntrack_find_get(sock_net(sk), &nf_ct_zone_dflt, &tuple);
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if (!h) {
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pr_debug("IP6T_SO_ORIGINAL_DST: Can't find %pI6c/%u-%pI6c/%u.\n",
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&tuple.src.u3.ip6, ntohs(tuple.src.u.tcp.port),
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&tuple.dst.u3.ip6, ntohs(tuple.dst.u.tcp.port));
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return -ENOENT;
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}
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ct = nf_ct_tuplehash_to_ctrack(h);
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sin6.sin6_family = AF_INET6;
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sin6.sin6_port = ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.u.tcp.port;
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sin6.sin6_flowinfo = inet6->flow_label & IPV6_FLOWINFO_MASK;
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memcpy(&sin6.sin6_addr,
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&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.u3.in6,
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sizeof(sin6.sin6_addr));
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nf_ct_put(ct);
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sin6.sin6_scope_id = ipv6_iface_scope_id(&sin6.sin6_addr,
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sk->sk_bound_dev_if);
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return copy_to_user(user, &sin6, sizeof(sin6)) ? -EFAULT : 0;
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}
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#if IS_ENABLED(CONFIG_NF_CT_NETLINK)
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#include <linux/netfilter/nfnetlink.h>
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#include <linux/netfilter/nfnetlink_conntrack.h>
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static int ipv6_tuple_to_nlattr(struct sk_buff *skb,
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const struct nf_conntrack_tuple *tuple)
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{
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if (nla_put_in6_addr(skb, CTA_IP_V6_SRC, &tuple->src.u3.in6) ||
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nla_put_in6_addr(skb, CTA_IP_V6_DST, &tuple->dst.u3.in6))
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goto nla_put_failure;
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return 0;
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nla_put_failure:
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return -1;
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}
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static const struct nla_policy ipv6_nla_policy[CTA_IP_MAX+1] = {
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[CTA_IP_V6_SRC] = { .len = sizeof(u_int32_t)*4 },
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[CTA_IP_V6_DST] = { .len = sizeof(u_int32_t)*4 },
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};
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static int ipv6_nlattr_to_tuple(struct nlattr *tb[],
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struct nf_conntrack_tuple *t)
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{
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if (!tb[CTA_IP_V6_SRC] || !tb[CTA_IP_V6_DST])
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return -EINVAL;
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t->src.u3.in6 = nla_get_in6_addr(tb[CTA_IP_V6_SRC]);
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t->dst.u3.in6 = nla_get_in6_addr(tb[CTA_IP_V6_DST]);
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return 0;
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}
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static int ipv6_nlattr_tuple_size(void)
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{
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return nla_policy_len(ipv6_nla_policy, CTA_IP_MAX + 1);
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}
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#endif
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struct nf_conntrack_l3proto nf_conntrack_l3proto_ipv6 __read_mostly = {
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.l3proto = PF_INET6,
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.name = "ipv6",
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.pkt_to_tuple = ipv6_pkt_to_tuple,
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.invert_tuple = ipv6_invert_tuple,
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.print_tuple = ipv6_print_tuple,
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.get_l4proto = ipv6_get_l4proto,
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#if IS_ENABLED(CONFIG_NF_CT_NETLINK)
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.tuple_to_nlattr = ipv6_tuple_to_nlattr,
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.nlattr_tuple_size = ipv6_nlattr_tuple_size,
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.nlattr_to_tuple = ipv6_nlattr_to_tuple,
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.nla_policy = ipv6_nla_policy,
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#endif
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.me = THIS_MODULE,
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};
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MODULE_ALIAS("nf_conntrack-" __stringify(AF_INET6));
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MODULE_LICENSE("GPL");
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MODULE_AUTHOR("Yasuyuki KOZAKAI @USAGI <yasuyuki.kozakai@toshiba.co.jp>");
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static struct nf_sockopt_ops so_getorigdst6 = {
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.pf = NFPROTO_IPV6,
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.get_optmin = IP6T_SO_ORIGINAL_DST,
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.get_optmax = IP6T_SO_ORIGINAL_DST + 1,
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.get = ipv6_getorigdst,
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.owner = THIS_MODULE,
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};
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static int ipv6_net_init(struct net *net)
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{
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int ret = 0;
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ret = nf_ct_l4proto_pernet_register(net, &nf_conntrack_l4proto_tcp6);
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if (ret < 0) {
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pr_err("nf_conntrack_tcp6: pernet registration failed\n");
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goto out;
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}
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ret = nf_ct_l4proto_pernet_register(net, &nf_conntrack_l4proto_udp6);
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if (ret < 0) {
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pr_err("nf_conntrack_udp6: pernet registration failed\n");
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goto cleanup_tcp6;
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}
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ret = nf_ct_l4proto_pernet_register(net, &nf_conntrack_l4proto_icmpv6);
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if (ret < 0) {
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pr_err("nf_conntrack_icmp6: pernet registration failed\n");
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goto cleanup_udp6;
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}
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ret = nf_ct_l3proto_pernet_register(net, &nf_conntrack_l3proto_ipv6);
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if (ret < 0) {
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pr_err("nf_conntrack_ipv6: pernet registration failed.\n");
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goto cleanup_icmpv6;
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}
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return 0;
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cleanup_icmpv6:
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nf_ct_l4proto_pernet_unregister(net, &nf_conntrack_l4proto_icmpv6);
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cleanup_udp6:
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nf_ct_l4proto_pernet_unregister(net, &nf_conntrack_l4proto_udp6);
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cleanup_tcp6:
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nf_ct_l4proto_pernet_unregister(net, &nf_conntrack_l4proto_tcp6);
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out:
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return ret;
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}
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static void ipv6_net_exit(struct net *net)
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{
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nf_ct_l3proto_pernet_unregister(net, &nf_conntrack_l3proto_ipv6);
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nf_ct_l4proto_pernet_unregister(net, &nf_conntrack_l4proto_icmpv6);
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nf_ct_l4proto_pernet_unregister(net, &nf_conntrack_l4proto_udp6);
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nf_ct_l4proto_pernet_unregister(net, &nf_conntrack_l4proto_tcp6);
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}
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static struct pernet_operations ipv6_net_ops = {
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.init = ipv6_net_init,
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.exit = ipv6_net_exit,
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};
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static int __init nf_conntrack_l3proto_ipv6_init(void)
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{
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int ret = 0;
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need_conntrack();
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nf_defrag_ipv6_enable();
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ret = nf_register_sockopt(&so_getorigdst6);
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if (ret < 0) {
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pr_err("Unable to register netfilter socket option\n");
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return ret;
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}
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ret = register_pernet_subsys(&ipv6_net_ops);
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if (ret < 0)
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goto cleanup_sockopt;
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ret = nf_register_hooks(ipv6_conntrack_ops,
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ARRAY_SIZE(ipv6_conntrack_ops));
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if (ret < 0) {
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pr_err("nf_conntrack_ipv6: can't register pre-routing defrag "
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"hook.\n");
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goto cleanup_pernet;
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}
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ret = nf_ct_l4proto_register(&nf_conntrack_l4proto_tcp6);
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if (ret < 0) {
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pr_err("nf_conntrack_ipv6: can't register tcp6 proto.\n");
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goto cleanup_hooks;
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}
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ret = nf_ct_l4proto_register(&nf_conntrack_l4proto_udp6);
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if (ret < 0) {
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pr_err("nf_conntrack_ipv6: can't register udp6 proto.\n");
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goto cleanup_tcp6;
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}
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ret = nf_ct_l4proto_register(&nf_conntrack_l4proto_icmpv6);
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if (ret < 0) {
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pr_err("nf_conntrack_ipv6: can't register icmpv6 proto.\n");
|
|
goto cleanup_udp6;
|
|
}
|
|
|
|
ret = nf_ct_l3proto_register(&nf_conntrack_l3proto_ipv6);
|
|
if (ret < 0) {
|
|
pr_err("nf_conntrack_ipv6: can't register ipv6 proto.\n");
|
|
goto cleanup_icmpv6;
|
|
}
|
|
return ret;
|
|
|
|
cleanup_icmpv6:
|
|
nf_ct_l4proto_unregister(&nf_conntrack_l4proto_icmpv6);
|
|
cleanup_udp6:
|
|
nf_ct_l4proto_unregister(&nf_conntrack_l4proto_udp6);
|
|
cleanup_tcp6:
|
|
nf_ct_l4proto_unregister(&nf_conntrack_l4proto_tcp6);
|
|
cleanup_hooks:
|
|
nf_unregister_hooks(ipv6_conntrack_ops, ARRAY_SIZE(ipv6_conntrack_ops));
|
|
cleanup_pernet:
|
|
unregister_pernet_subsys(&ipv6_net_ops);
|
|
cleanup_sockopt:
|
|
nf_unregister_sockopt(&so_getorigdst6);
|
|
return ret;
|
|
}
|
|
|
|
static void __exit nf_conntrack_l3proto_ipv6_fini(void)
|
|
{
|
|
synchronize_net();
|
|
nf_ct_l3proto_unregister(&nf_conntrack_l3proto_ipv6);
|
|
nf_ct_l4proto_unregister(&nf_conntrack_l4proto_tcp6);
|
|
nf_ct_l4proto_unregister(&nf_conntrack_l4proto_udp6);
|
|
nf_ct_l4proto_unregister(&nf_conntrack_l4proto_icmpv6);
|
|
nf_unregister_hooks(ipv6_conntrack_ops, ARRAY_SIZE(ipv6_conntrack_ops));
|
|
unregister_pernet_subsys(&ipv6_net_ops);
|
|
nf_unregister_sockopt(&so_getorigdst6);
|
|
}
|
|
|
|
module_init(nf_conntrack_l3proto_ipv6_init);
|
|
module_exit(nf_conntrack_l3proto_ipv6_fini);
|