[IPV6]: Disallow RH0 by default.

A security issue is emerging.  Disallow Routing Header Type 0 by default
as we have been doing for IPv4.
Note: We allow RH2 by default because it is harmless.

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
YOSHIFUJI Hideaki 2007-04-24 14:58:30 -07:00 committed by David S. Miller
parent 05d224468a
commit 0bcbc92629
5 changed files with 58 additions and 6 deletions

View File

@ -851,6 +851,15 @@ accept_redirects - BOOLEAN
Functional default: enabled if local forwarding is disabled.
disabled if local forwarding is enabled.
accept_source_route - INTEGER
Accept source routing (routing extension header).
> 0: Accept routing header.
= 0: Accept only routing header type 2.
< 0: Do not accept routing header.
Default: 0
autoconf - BOOLEAN
Autoconfigure addresses using Prefix Information in Router
Advertisements.

View File

@ -177,6 +177,7 @@ struct ipv6_devconf {
#endif
#endif
__s32 proxy_ndp;
__s32 accept_source_route;
void *sysctl;
};
@ -205,6 +206,8 @@ enum {
DEVCONF_RTR_PROBE_INTERVAL,
DEVCONF_ACCEPT_RA_RT_INFO_MAX_PLEN,
DEVCONF_PROXY_NDP,
__DEVCONF_OPTIMISTIC_DAD,
DEVCONF_ACCEPT_SOURCE_ROUTE,
DEVCONF_MAX
};

View File

@ -580,6 +580,7 @@ enum {
NET_IPV6_RTR_PROBE_INTERVAL=21,
NET_IPV6_ACCEPT_RA_RT_INFO_MAX_PLEN=22,
NET_IPV6_PROXY_NDP=23,
NET_IPV6_ACCEPT_SOURCE_ROUTE=25,
__NET_IPV6_MAX
};

View File

@ -172,6 +172,7 @@ struct ipv6_devconf ipv6_devconf __read_mostly = {
#endif
#endif
.proxy_ndp = 0,
.accept_source_route = 0, /* we do not accept RH0 by default. */
};
static struct ipv6_devconf ipv6_devconf_dflt __read_mostly = {
@ -203,6 +204,7 @@ static struct ipv6_devconf ipv6_devconf_dflt __read_mostly = {
#endif
#endif
.proxy_ndp = 0,
.accept_source_route = 0, /* we do not accept RH0 by default. */
};
/* IPv6 Wildcard Address and Loopback Address defined by RFC2553 */
@ -3356,6 +3358,7 @@ static inline void ipv6_store_devconf(struct ipv6_devconf *cnf,
#endif
#endif
array[DEVCONF_PROXY_NDP] = cnf->proxy_ndp;
array[DEVCONF_ACCEPT_SOURCE_ROUTE] = cnf->accept_source_route;
}
static inline size_t inet6_if_nlmsg_size(void)
@ -3883,6 +3886,14 @@ static struct addrconf_sysctl_table
.mode = 0644,
.proc_handler = &proc_dointvec,
},
{
.ctl_name = NET_IPV6_ACCEPT_SOURCE_ROUTE,
.procname = "accept_source_route",
.data = &ipv6_devconf.accept_source_route,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = &proc_dointvec,
},
{
.ctl_name = 0, /* sentinel */
}

View File

@ -362,10 +362,27 @@ static int ipv6_rthdr_rcv(struct sk_buff **skbp)
struct inet6_skb_parm *opt = IP6CB(skb);
struct in6_addr *addr = NULL;
struct in6_addr daddr;
struct inet6_dev *idev;
int n, i;
struct ipv6_rt_hdr *hdr;
struct rt0_hdr *rthdr;
int accept_source_route = ipv6_devconf.accept_source_route;
if (accept_source_route < 0 ||
((idev = in6_dev_get(skb->dev)) == NULL)) {
kfree_skb(skb);
return -1;
}
if (idev->cnf.accept_source_route < 0) {
in6_dev_put(idev);
kfree_skb(skb);
return -1;
}
if (accept_source_route > idev->cnf.accept_source_route)
accept_source_route = idev->cnf.accept_source_route;
in6_dev_put(idev);
if (!pskb_may_pull(skb, (skb->h.raw-skb->data)+8) ||
!pskb_may_pull(skb, (skb->h.raw-skb->data)+((skb->h.raw[1]+1)<<3))) {
@ -377,6 +394,22 @@ static int ipv6_rthdr_rcv(struct sk_buff **skbp)
hdr = (struct ipv6_rt_hdr *) skb->h.raw;
switch (hdr->type) {
#ifdef CONFIG_IPV6_MIP6
break;
#endif
case IPV6_SRCRT_TYPE_0:
if (accept_source_route <= 0)
break;
kfree_skb(skb);
return -1;
default:
IP6_INC_STATS_BH(ip6_dst_idev(skb->dst),
IPSTATS_MIB_INHDRERRORS);
icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, (&hdr->type) - skb->nh.raw);
return -1;
}
if (ipv6_addr_is_multicast(&skb->nh.ipv6h->daddr) ||
skb->pkt_type != PACKET_HOST) {
IP6_INC_STATS_BH(ip6_dst_idev(skb->dst),
@ -434,11 +467,6 @@ looped_back:
}
break;
#endif
default:
IP6_INC_STATS_BH(ip6_dst_idev(skb->dst),
IPSTATS_MIB_INHDRERRORS);
icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, (&hdr->type) - skb->nh.raw);
return -1;
}
/*