/*
* Internet Control Message Protocol (ICMPv6)
* Linux INET6 implementation
*
* Authors:
* Pedro Roque <roque@di.fc.ul.pt>
*
* Based on net/ipv4/icmp.c
*
* RFC 1885
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
/*
* Changes:
*
* Andi Kleen : exception handling
* Andi Kleen add rate limits. never reply to a icmp.
* add more length checks and other fixes.
* yoshfuji : ensure to sent parameter problem for
* fragments.
* YOSHIFUJI Hideaki @USAGI: added sysctl for icmp rate limit.
* Randy Dunlap and
* YOSHIFUJI Hideaki @USAGI: Per-interface statistics support
* Kazunori MIYAZAWA @USAGI: change output process to use ip6_append_data
*/
#define pr_fmt(fmt) "IPv6: " fmt
#include <linux/module.h>
#include <linux/errno.h>
#include <linux/types.h>
#include <linux/socket.h>
#include <linux/in.h>
#include <linux/kernel.h>
#include <linux/sockios.h>
#include <linux/net.h>
#include <linux/skbuff.h>
#include <linux/init.h>
#include <linux/netfilter.h>
#include <linux/slab.h>
#ifdef CONFIG_SYSCTL
#include <linux/sysctl.h>
#endif
#include <linux/inet.h>
#include <linux/netdevice.h>
#include <linux/icmpv6.h>
#include <net/ip.h>
#include <net/sock.h>
#include <net/ipv6.h>
#include <net/ip6_checksum.h>
#include <net/ping.h>
#include <net/protocol.h>
#include <net/raw.h>
#include <net/rawv6.h>
#include <net/transp_v6.h>
#include <net/ip6_route.h>
#include <net/addrconf.h>
#include <net/icmp.h>
#include <net/xfrm.h>
#include <net/inet_common.h>
#include <net/dsfield.h>
#include <asm/uaccess.h>
/*
* The ICMP socket(s). This is the most convenient way to flow control
* our ICMP output as well as maintain a clean interface throughout
* all layers. All Socketless IP sends will soon be gone.
*
* On SMP we have one ICMP socket per-cpu.
*/
static inline struct sock *icmpv6_sk(struct net *net)
{
return net->ipv6.icmp_sk[smp_processor_id()];
}
static void icmpv6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
u8 type, u8 code, int offset, __be32 info)
{
/* icmpv6_notify checks 8 bytes can be pulled, icmp6hdr is 8 bytes */
struct icmp6hdr *icmp6 = (struct icmp6hdr *) (skb->data + offset);
struct net *net = dev_net(skb->dev);
if (type == ICMPV6_PKT_TOOBIG)
ip6_update_pmtu(skb, net, info, 0, 0);
else if (type == NDISC_REDIRECT)
ip6_redirect(skb, net, skb->dev->ifindex, 0);
if (!(type & ICMPV6_INFOMSG_MASK))
if (icmp6->icmp6_type == ICMPV6_ECHO_REQUEST)
ping_err(skb, offset, info);
}
static int icmpv6_rcv(struct sk_buff *skb);
static const struct inet6_protocol icmpv6_protocol = {
.handler = icmpv6_rcv,
.err_handler = icmpv6_err,
.flags = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
};
static __inline__ struct sock *icmpv6_xmit_lock(struct net *net)
{
struct sock *sk;
local_bh_disable();
sk = icmpv6_sk(net);
if (unlikely(!spin_trylock(&sk->sk_lock.slock))) {
/* This can happen if the output path (f.e. SIT or
* ip6ip6 tunnel) signals dst_link_failure() for an
* outgoing ICMP6 packet.
*/
local_bh_enable();
return NULL;
}
return sk;
}
static __inline__ void icmpv6_xmit_unlock(struct sock *sk)
{
spin_unlock_bh(&sk->sk_lock.slock);
}
/*
* Figure out, may we reply to this packet with icmp error.
*
* We do not reply, if:
* - it was icmp error message.
* - it is truncated, so that it is known, that protocol is ICMPV6
* (i.e. in the middle of some exthdr)
*
* --ANK (980726)
*/
static bool is_ineligible(const struct sk_buff *skb)
{
int ptr = (u8 *)(ipv6_hdr(skb) + 1) - skb->data;
int len = skb->len - ptr;
__u8 nexthdr = ipv6_hdr(skb)->nexthdr;
__be16 frag_off;
if (len < 0)
return true;
ptr = ipv6_skip_exthdr(skb, ptr, &nexthdr, &frag_off);
if (ptr < 0)
return false;
if (nexthdr == IPPROTO_ICMPV6) {
u8 _type, *tp;
tp = skb_header_pointer(skb,
ptr+offsetof(struct icmp6hdr, icmp6_type),
sizeof(_type), &_type);
if (tp == NULL ||
!(*tp & ICMPV6_INFOMSG_MASK))
return true;
}
return false;
}
/*
* Check the ICMP output rate limit
*/
static inline bool icmpv6_xrlim_allow(struct sock *sk, u8 type,
struct flowi6 *fl6)
{
struct dst_entry *