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DEFINITIONS
This source file includes following definitions.
- icmpv6_pkt_to_tuple
- icmpv6_invert_tuple
- icmpv6_print_tuple
- icmpv6_packet
- icmpv6_new
- icmpv6_error_message
- icmpv6_error
- icmpv6_tuple_to_nlattr
- icmpv6_nlattr_to_tuple
/*
* Copyright (C)2003,2004 USAGI/WIDE Project
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* Author:
* Yasuyuki Kozakai @USAGI <yasuyuki.kozakai@toshiba.co.jp>
*/
#include <linux/types.h>
#include <linux/timer.h>
#include <linux/module.h>
#include <linux/netfilter.h>
#include <linux/in6.h>
#include <linux/icmpv6.h>
#include <linux/ipv6.h>
#include <net/ipv6.h>
#include <net/ip6_checksum.h>
#include <linux/seq_file.h>
#include <linux/netfilter_ipv6.h>
#include <net/netfilter/nf_conntrack_tuple.h>
#include <net/netfilter/nf_conntrack_l4proto.h>
#include <net/netfilter/nf_conntrack_core.h>
#include <net/netfilter/ipv6/nf_conntrack_icmpv6.h>
#include <net/netfilter/nf_log.h>
static unsigned long nf_ct_icmpv6_timeout __read_mostly = 30*HZ;
static bool icmpv6_pkt_to_tuple(const struct sk_buff *skb,
unsigned int dataoff,
struct nf_conntrack_tuple *tuple)
{
const struct icmp6hdr *hp;
struct icmp6hdr _hdr;
hp = skb_header_pointer(skb, dataoff, sizeof(_hdr), &_hdr);
if (hp == NULL)
return false;
tuple->dst.u.icmp.type = hp->icmp6_type;
tuple->src.u.icmp.id = hp->icmp6_identifier;
tuple->dst.u.icmp.code = hp->icmp6_code;
return true;
}
/* Add 1; spaces filled with 0. */
static const u_int8_t invmap[] = {
[ICMPV6_ECHO_REQUEST - 128] = ICMPV6_ECHO_REPLY + 1,
[ICMPV6_ECHO_REPLY - 128] = ICMPV6_ECHO_REQUEST + 1,
[ICMPV6_NI_QUERY - 128] = ICMPV6_NI_QUERY + 1,
[ICMPV6_NI_REPLY - 128] = ICMPV6_NI_REPLY +1
};
static bool icmpv6_invert_tuple(struct nf_conntrack_tuple *tuple,
const struct nf_conntrack_tuple *orig)
{
int type = orig->dst.u.icmp.type - 128;
if (type < 0 || type >= sizeof(invmap) || !invmap[type])
return false;
tuple->src.u.icmp.id = orig->src.u.icmp.id;
tuple->dst.u.icmp.type = invmap[type] - 1;
tuple->dst.u.icmp.code = orig->dst.u.icmp.code;
return true;
}
/* Print out the per-protocol part of the tuple. */
static int icmpv6_print_tuple(struct seq_file *s,
const struct nf_conntrack_tuple *tuple)
{
return seq_printf(s, "type=%u code=%u id=%u ",
tuple->dst.u.icmp.type,
tuple->dst.u.icmp.code,
ntohs(tuple->src.u.icmp.id));
}
/* Returns verdict for packet, or -1 for invalid. */
static int icmpv6_packet(struct nf_conn *ct,
const struct sk_buff *skb,
unsigned int dataoff,
enum ip_conntrack_info ctinfo,
u_int8_t pf,
unsigned int hooknum)
{
/* Try to delete connection immediately after all replies:
won't actually vanish as we still have skb, and del_timer
means this will only run once even if count hits zero twice
(theoretically possible with SMP) */
if (CTINFO2DIR(ctinfo) == IP_CT_DIR_REPLY) {
if (atomic_dec_and_test(&ct->proto.icmp.count))
nf_ct_kill_acct(ct, ctinfo, skb);
} else {
atomic_inc(&ct->proto.icmp.count);
nf_conntrack_event_cache(IPCT_PROTOINFO_VOLATILE, ct);
nf_ct_refresh_acct(ct, ctinfo, skb, nf_ct_icmpv6_timeout);
}
return NF_ACCEPT;
}
/* Called when a new connection for this protocol found. */
static bool icmpv6_new(struct nf_conn *ct, const struct sk_buff *skb,
unsigned int dataoff)
{
static const u_int8_t valid_new[] = {
[ICMPV6_ECHO_REQUEST - 128] = 1,
[ICMPV6_NI_QUERY - 128] = 1
};
int type = ct->tuplehash[0].tuple.dst.u.icmp.type - 128;
if (type < 0 || type >= sizeof(valid_new) || !valid_new[type]) {
/* Can't create a new ICMPv6 `conn' with this. */
pr_debug("icmpv6: can't create new conn with type %u\n",
type + 128);
nf_ct_dump_tuple_ipv6(&ct->tuplehash[0].tuple);
return false;
}
atomic_set(&ct->proto.icmp.count, 0);
return true;
}
static int
icmpv6_error_message(struct net *net,
struct sk_buff *skb,
unsigned int icmp6off,
enum ip_conntrack_info *ctinfo,
unsigned int hooknum)
{
struct nf_conntrack_tuple intuple, origtuple;
const struct nf_conntrack_tuple_hash *h;
const struct nf_conntrack_l4proto *inproto;
NF_CT_ASSERT(skb->nfct == NULL);
/* Are they talking about one of our connections? */
if (!nf_ct_get_tuplepr(skb,
skb_network_offset(skb)
+ sizeof(struct ipv6hdr)
+ sizeof(struct icmp6hdr),
PF_INET6, &origtuple)) {
pr_debug("icmpv6_error: Can't get tuple\n");
return -NF_ACCEPT;
}
/* rcu_read_lock()ed by nf_hook_slow */
inproto = __nf_ct_l4proto_find(PF_INET6, origtuple.dst.protonum);
/* Ordinarily, we'd expect the inverted tupleproto, but it's
been preserved inside the ICMP. */
if (!nf_ct_invert_tuple(&intuple, &origtuple,
&nf_conntrack_l3proto_ipv6, inproto)) {
pr_debug("icmpv6_error: Can't invert tuple\n");
return -NF_ACCEPT;
}
*ctinfo = IP_CT_RELATED;
h = nf_conntrack_find_get(net, &intuple);
if (!h) {
pr_debug("icmpv6_error: no match\n");
return -NF_ACCEPT;
} else {
if (NF_CT_DIRECTION(h) == IP_CT_DIR_REPLY)
*ctinfo += IP_CT_IS_REPLY;
}
/* Update skb to refer to this connection */
skb->nfct = &nf_ct_tuplehash_to_ctrack(h)->ct_general;
skb->nfctinfo = *ctinfo;
return -NF_ACCEPT;
}
static int
icmpv6_error(struct net *net, struct sk_buff *skb, unsigned int dataoff,
enum ip_conntrack_info *ctinfo, u_int8_t pf, unsigned int hooknum)
{
const struct icmp6hdr *icmp6h;
struct icmp6hdr _ih;
icmp6h = skb_header_pointer(skb, dataoff, sizeof(_ih), &_ih);
if (icmp6h == NULL) {
if (LOG_INVALID(net, IPPROTO_ICMPV6))
nf_log_packet(PF_INET6, 0, skb, NULL, NULL, NULL,
"nf_ct_icmpv6: short packet ");
return -NF_ACCEPT;
}
if (net->ct.sysctl_checksum && hooknum == NF_INET_PRE_ROUTING &&
nf_ip6_checksum(skb, hooknum, dataoff, IPPROTO_ICMPV6)) {
nf_log_packet(PF_INET6, 0, skb, NULL, NULL, NULL,
"nf_ct_icmpv6: ICMPv6 checksum failed\n");
return -NF_ACCEPT;
}
/* is not error message ? */
if (icmp6h->icmp6_type >= 128)
return NF_ACCEPT;
return icmpv6_error_message(net, skb, dataoff, ctinfo, hooknum);
}
#if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
#include <linux/netfilter/nfnetlink.h>
#include <linux/netfilter/nfnetlink_conntrack.h>
static int icmpv6_tuple_to_nlattr(struct sk_buff *skb,
const struct nf_conntrack_tuple *t)
{
NLA_PUT_BE16(skb, CTA_PROTO_ICMPV6_ID, t->src.u.icmp.id);
NLA_PUT_U8(skb, CTA_PROTO_ICMPV6_TYPE, t->dst.u.icmp.type);
NLA_PUT_U8(skb, CTA_PROTO_ICMPV6_CODE, t->dst.u.icmp.code);
return 0;
nla_put_failure:
return -1;
}
static const struct nla_policy icmpv6_nla_policy[CTA_PROTO_MAX+1] = {
[CTA_PROTO_ICMPV6_TYPE] = { .type = NLA_U8 },
[CTA_PROTO_ICMPV6_CODE] = { .type = NLA_U8 },
[CTA_PROTO_ICMPV6_ID] = { .type = NLA_U16 },
};
static int icmpv6_nlattr_to_tuple(struct nlattr *tb[],
struct nf_conntrack_tuple *tuple)
{
if (!tb[CTA_PROTO_ICMPV6_TYPE]
|| !tb[CTA_PROTO_ICMPV6_CODE]
|| !tb[CTA_PROTO_ICMPV6_ID])
return -EINVAL;
tuple->dst.u.icmp.type = nla_get_u8(tb[CTA_PROTO_ICMPV6_TYPE]);
tuple->dst.u.icmp.code = nla_get_u8(tb[CTA_PROTO_ICMPV6_CODE]);
tuple->src.u.icmp.id = nla_get_be16(tb[CTA_PROTO_ICMPV6_ID]);
if (tuple->dst.u.icmp.type < 128
|| tuple->dst.u.icmp.type - 128 >= sizeof(invmap)
|| !invmap[tuple->dst.u.icmp.type - 128])
return -EINVAL;
return 0;
}
#endif
#ifdef CONFIG_SYSCTL
static struct ctl_table_header *icmpv6_sysctl_header;
static struct ctl_table icmpv6_sysctl_table[] = {
{
.procname = "nf_conntrack_icmpv6_timeout",
.data = &nf_ct_icmpv6_timeout,
.maxlen = sizeof(unsigned int),
.mode = 0644,
.proc_handler = &proc_dointvec_jiffies,
},
{
.ctl_name = 0
}
};
#endif /* CONFIG_SYSCTL */
struct nf_conntrack_l4proto nf_conntrack_l4proto_icmpv6 __read_mostly =
{
.l3proto = PF_INET6,
.l4proto = IPPROTO_ICMPV6,
.name = "icmpv6",
.pkt_to_tuple = icmpv6_pkt_to_tuple,
.invert_tuple = icmpv6_invert_tuple,
.print_tuple = icmpv6_print_tuple,
.packet = icmpv6_packet,
.new = icmpv6_new,
.error = icmpv6_error,
#if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
.tuple_to_nlattr = icmpv6_tuple_to_nlattr,
.nlattr_to_tuple = icmpv6_nlattr_to_tuple,
.nla_policy = icmpv6_nla_policy,
#endif
#ifdef CONFIG_SYSCTL
.ctl_table_header = &icmpv6_sysctl_header,
.ctl_table = icmpv6_sysctl_table,
#endif
};