266 строки
6.5 KiB
C
266 строки
6.5 KiB
C
/*
|
|
* IPv6 specific functions of netfilter core
|
|
*
|
|
* Rusty Russell (C) 2000 -- This code is GPL.
|
|
* Patrick McHardy (C) 2006-2012
|
|
*/
|
|
#include <linux/kernel.h>
|
|
#include <linux/init.h>
|
|
#include <linux/ipv6.h>
|
|
#include <linux/netfilter.h>
|
|
#include <linux/netfilter_ipv6.h>
|
|
#include <linux/export.h>
|
|
#include <net/addrconf.h>
|
|
#include <net/dst.h>
|
|
#include <net/ipv6.h>
|
|
#include <net/ip6_route.h>
|
|
#include <net/xfrm.h>
|
|
#include <net/netfilter/nf_queue.h>
|
|
#include <net/netfilter/nf_conntrack_bridge.h>
|
|
#include <net/netfilter/ipv6/nf_defrag_ipv6.h>
|
|
#include "../bridge/br_private.h"
|
|
|
|
int ip6_route_me_harder(struct net *net, struct sk_buff *skb)
|
|
{
|
|
const struct ipv6hdr *iph = ipv6_hdr(skb);
|
|
struct sock *sk = sk_to_full_sk(skb->sk);
|
|
unsigned int hh_len;
|
|
struct dst_entry *dst;
|
|
int strict = (ipv6_addr_type(&iph->daddr) &
|
|
(IPV6_ADDR_MULTICAST | IPV6_ADDR_LINKLOCAL));
|
|
struct flowi6 fl6 = {
|
|
.flowi6_oif = sk && sk->sk_bound_dev_if ? sk->sk_bound_dev_if :
|
|
strict ? skb_dst(skb)->dev->ifindex : 0,
|
|
.flowi6_mark = skb->mark,
|
|
.flowi6_uid = sock_net_uid(net, sk),
|
|
.daddr = iph->daddr,
|
|
.saddr = iph->saddr,
|
|
};
|
|
int err;
|
|
|
|
dst = ip6_route_output(net, sk, &fl6);
|
|
err = dst->error;
|
|
if (err) {
|
|
IP6_INC_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTNOROUTES);
|
|
net_dbg_ratelimited("ip6_route_me_harder: No more route\n");
|
|
dst_release(dst);
|
|
return err;
|
|
}
|
|
|
|
/* Drop old route. */
|
|
skb_dst_drop(skb);
|
|
|
|
skb_dst_set(skb, dst);
|
|
|
|
#ifdef CONFIG_XFRM
|
|
if (!(IP6CB(skb)->flags & IP6SKB_XFRM_TRANSFORMED) &&
|
|
xfrm_decode_session(skb, flowi6_to_flowi(&fl6), AF_INET6) == 0) {
|
|
skb_dst_set(skb, NULL);
|
|
dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), sk, 0);
|
|
if (IS_ERR(dst))
|
|
return PTR_ERR(dst);
|
|
skb_dst_set(skb, dst);
|
|
}
|
|
#endif
|
|
|
|
/* Change in oif may mean change in hh_len. */
|
|
hh_len = skb_dst(skb)->dev->hard_header_len;
|
|
if (skb_headroom(skb) < hh_len &&
|
|
pskb_expand_head(skb, HH_DATA_ALIGN(hh_len - skb_headroom(skb)),
|
|
0, GFP_ATOMIC))
|
|
return -ENOMEM;
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL(ip6_route_me_harder);
|
|
|
|
static int nf_ip6_reroute(struct sk_buff *skb,
|
|
const struct nf_queue_entry *entry)
|
|
{
|
|
struct ip6_rt_info *rt_info = nf_queue_entry_reroute(entry);
|
|
|
|
if (entry->state.hook == NF_INET_LOCAL_OUT) {
|
|
const struct ipv6hdr *iph = ipv6_hdr(skb);
|
|
if (!ipv6_addr_equal(&iph->daddr, &rt_info->daddr) ||
|
|
!ipv6_addr_equal(&iph->saddr, &rt_info->saddr) ||
|
|
skb->mark != rt_info->mark)
|
|
return ip6_route_me_harder(entry->state.net, skb);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
int __nf_ip6_route(struct net *net, struct dst_entry **dst,
|
|
struct flowi *fl, bool strict)
|
|
{
|
|
static const struct ipv6_pinfo fake_pinfo;
|
|
static const struct inet_sock fake_sk = {
|
|
/* makes ip6_route_output set RT6_LOOKUP_F_IFACE: */
|
|
.sk.sk_bound_dev_if = 1,
|
|
.pinet6 = (struct ipv6_pinfo *) &fake_pinfo,
|
|
};
|
|
const void *sk = strict ? &fake_sk : NULL;
|
|
struct dst_entry *result;
|
|
int err;
|
|
|
|
result = ip6_route_output(net, sk, &fl->u.ip6);
|
|
err = result->error;
|
|
if (err)
|
|
dst_release(result);
|
|
else
|
|
*dst = result;
|
|
return err;
|
|
}
|
|
EXPORT_SYMBOL_GPL(__nf_ip6_route);
|
|
|
|
int br_ip6_fragment(struct net *net, struct sock *sk, struct sk_buff *skb,
|
|
struct nf_bridge_frag_data *data,
|
|
int (*output)(struct net *, struct sock *sk,
|
|
const struct nf_bridge_frag_data *data,
|
|
struct sk_buff *))
|
|
{
|
|
int frag_max_size = BR_INPUT_SKB_CB(skb)->frag_max_size;
|
|
ktime_t tstamp = skb->tstamp;
|
|
struct ip6_frag_state state;
|
|
u8 *prevhdr, nexthdr = 0;
|
|
unsigned int mtu, hlen;
|
|
int hroom, err = 0;
|
|
__be32 frag_id;
|
|
|
|
err = ip6_find_1stfragopt(skb, &prevhdr);
|
|
if (err < 0)
|
|
goto blackhole;
|
|
hlen = err;
|
|
nexthdr = *prevhdr;
|
|
|
|
mtu = skb->dev->mtu;
|
|
if (frag_max_size > mtu ||
|
|
frag_max_size < IPV6_MIN_MTU)
|
|
goto blackhole;
|
|
|
|
mtu = frag_max_size;
|
|
if (mtu < hlen + sizeof(struct frag_hdr) + 8)
|
|
goto blackhole;
|
|
mtu -= hlen + sizeof(struct frag_hdr);
|
|
|
|
frag_id = ipv6_select_ident(net, &ipv6_hdr(skb)->daddr,
|
|
&ipv6_hdr(skb)->saddr);
|
|
|
|
if (skb->ip_summed == CHECKSUM_PARTIAL &&
|
|
(err = skb_checksum_help(skb)))
|
|
goto blackhole;
|
|
|
|
hroom = LL_RESERVED_SPACE(skb->dev);
|
|
if (skb_has_frag_list(skb)) {
|
|
unsigned int first_len = skb_pagelen(skb);
|
|
struct ip6_fraglist_iter iter;
|
|
struct sk_buff *frag2;
|
|
|
|
if (first_len - hlen > mtu ||
|
|
skb_headroom(skb) < (hroom + sizeof(struct frag_hdr)))
|
|
goto blackhole;
|
|
|
|
if (skb_cloned(skb))
|
|
goto slow_path;
|
|
|
|
skb_walk_frags(skb, frag2) {
|
|
if (frag2->len > mtu ||
|
|
skb_headroom(frag2) < (hlen + hroom + sizeof(struct frag_hdr)))
|
|
goto blackhole;
|
|
|
|
/* Partially cloned skb? */
|
|
if (skb_shared(frag2))
|
|
goto slow_path;
|
|
}
|
|
|
|
err = ip6_fraglist_init(skb, hlen, prevhdr, nexthdr, frag_id,
|
|
&iter);
|
|
if (err < 0)
|
|
goto blackhole;
|
|
|
|
for (;;) {
|
|
/* Prepare header of the next frame,
|
|
* before previous one went down.
|
|
*/
|
|
if (iter.frag)
|
|
ip6_fraglist_prepare(skb, &iter);
|
|
|
|
skb->tstamp = tstamp;
|
|
err = output(net, sk, data, skb);
|
|
if (err || !iter.frag)
|
|
break;
|
|
|
|
skb = ip6_fraglist_next(&iter);
|
|
}
|
|
|
|
kfree(iter.tmp_hdr);
|
|
if (!err)
|
|
return 0;
|
|
|
|
kfree_skb_list(iter.frag);
|
|
return err;
|
|
}
|
|
slow_path:
|
|
/* This is a linearized skbuff, the original geometry is lost for us.
|
|
* This may also be a clone skbuff, we could preserve the geometry for
|
|
* the copies but probably not worth the effort.
|
|
*/
|
|
ip6_frag_init(skb, hlen, mtu, skb->dev->needed_tailroom,
|
|
LL_RESERVED_SPACE(skb->dev), prevhdr, nexthdr, frag_id,
|
|
&state);
|
|
|
|
while (state.left > 0) {
|
|
struct sk_buff *skb2;
|
|
|
|
skb2 = ip6_frag_next(skb, &state);
|
|
if (IS_ERR(skb2)) {
|
|
err = PTR_ERR(skb2);
|
|
goto blackhole;
|
|
}
|
|
|
|
skb2->tstamp = tstamp;
|
|
err = output(net, sk, data, skb2);
|
|
if (err)
|
|
goto blackhole;
|
|
}
|
|
consume_skb(skb);
|
|
return err;
|
|
|
|
blackhole:
|
|
kfree_skb(skb);
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(br_ip6_fragment);
|
|
|
|
static const struct nf_ipv6_ops ipv6ops = {
|
|
#if IS_MODULE(CONFIG_IPV6)
|
|
.chk_addr = ipv6_chk_addr,
|
|
.route_me_harder = ip6_route_me_harder,
|
|
.dev_get_saddr = ipv6_dev_get_saddr,
|
|
.route = __nf_ip6_route,
|
|
#if IS_ENABLED(CONFIG_SYN_COOKIES)
|
|
.cookie_init_sequence = __cookie_v6_init_sequence,
|
|
.cookie_v6_check = __cookie_v6_check,
|
|
#endif
|
|
#endif
|
|
.route_input = ip6_route_input,
|
|
.fragment = ip6_fragment,
|
|
.reroute = nf_ip6_reroute,
|
|
#if IS_MODULE(CONFIG_IPV6)
|
|
.br_fragment = br_ip6_fragment,
|
|
#endif
|
|
};
|
|
|
|
int __init ipv6_netfilter_init(void)
|
|
{
|
|
RCU_INIT_POINTER(nf_ipv6_ops, &ipv6ops);
|
|
return 0;
|
|
}
|
|
|
|
/* This can be called from inet6_init() on errors, so it cannot
|
|
* be marked __exit. -DaveM
|
|
*/
|
|
void ipv6_netfilter_fini(void)
|
|
{
|
|
RCU_INIT_POINTER(nf_ipv6_ops, NULL);
|
|
}
|