| Message ID | 20130117033258.GA23782@order.stressinduktion.org |
|---|---|
| State | Superseded, archived |
| Delegated to: | David Miller |
| Headers | show |
On Thu, Jan 17, 2013 at 04:32:58AM +0100, Hannes Frederic Sowa wrote: > +static int sit_chksrc(struct ip_tunnel *tunnel, const __be32 *addr, > + const struct in6_addr *addr6) > +{ > +#ifdef CONFIG_IPV6_SIT_6RD > + if (ipv6_prefix_equal(addr6, &tunnel->ip6rd.prefix, > + tunnel->ip6rd.prefixlen) && > + memcmp(addr, &addr6->s6_addr16[1], 4)) > + return 0; This is wrong. David, please drop my patch, sorry. I will respin another one. In 6rd setups one can, of course, have longer prefixlens than 16. Thanks! -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Hannes Frederic Sowa wrote: > This patch adds anti-spoofing checks in sit.c as specified in RFC3964 > section 5.2 for 6to4 and RFC5969 section 12 for 6rd. I left out the > checks which could easily be implemented with netfilter. > > Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org> > --- > net/ipv6/sit.c | 27 +++++++++++++++++++++++++-- > 1 file changed, 25 insertions(+), 2 deletions(-) > > diff --git a/net/ipv6/sit.c b/net/ipv6/sit.c > index cfba99b..2b4c15a 100644 > --- a/net/ipv6/sit.c > +++ b/net/ipv6/sit.c > @@ -590,6 +590,22 @@ out: > return err; > } > > +static int sit_chksrc(struct ip_tunnel *tunnel, const __be32 *addr, > + const struct in6_addr *addr6) > +{ > +#ifdef CONFIG_IPV6_SIT_6RD > + if (ipv6_prefix_equal(addr6, &tunnel->ip6rd.prefix, > + tunnel->ip6rd.prefixlen) && > + memcmp(addr, &addr6->s6_addr16[1], 4)) > + return 0; > +#else > + if (addr6->s6_addr16[0] == htons(0x2002) && > + memcmp(addr, &addr6->s6_addr16[1], 4)) > + return 0; > +#endif > + return 1; > It seems wrong. Check should be done for - inner source prefix - embedded source with relay_prefix. - inner destination prefix. Note: embedded destination is not being checked. --yoshfuji -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Fri, Jan 18, 2013 at 12:44:11AM +0900, YOSHIFUJI Hideaki wrote: > Hannes Frederic Sowa wrote: > > This patch adds anti-spoofing checks in sit.c as specified in RFC3964 > > section 5.2 for 6to4 and RFC5969 section 12 for 6rd. I left out the > > checks which could easily be implemented with netfilter. > > > > Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org> > > --- > > net/ipv6/sit.c | 27 +++++++++++++++++++++++++-- > > 1 file changed, 25 insertions(+), 2 deletions(-) > > > > diff --git a/net/ipv6/sit.c b/net/ipv6/sit.c > > index cfba99b..2b4c15a 100644 > > --- a/net/ipv6/sit.c > > +++ b/net/ipv6/sit.c > > @@ -590,6 +590,22 @@ out: > > return err; > > } > > > > +static int sit_chksrc(struct ip_tunnel *tunnel, const __be32 *addr, > > + const struct in6_addr *addr6) > > +{ > > +#ifdef CONFIG_IPV6_SIT_6RD > > + if (ipv6_prefix_equal(addr6, &tunnel->ip6rd.prefix, > > + tunnel->ip6rd.prefixlen) && > > + memcmp(addr, &addr6->s6_addr16[1], 4)) > > + return 0; > > +#else > > + if (addr6->s6_addr16[0] == htons(0x2002) && > > + memcmp(addr, &addr6->s6_addr16[1], 4)) > > + return 0; > > +#endif > > + return 1; > > > > It seems wrong. Check should be done for > - inner source prefix I intentionally skipped this check because it could be easily checked with netfilter (after decapsulation) and I am a bit afraid breaking already working setups with non-standard prefixes. Do you think I should add this check anyway? > - embedded source with relay_prefix. I'll use try_6rd to extract the ipv4 address and check it against the outer address. I will check this later if I have access to my test setup. > - inner destination prefix. > > Note: embedded destination is not being checked. Also left these checks out because of the same reasons I stated above. Should they be added? Thanks for the review! -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/net/ipv6/sit.c b/net/ipv6/sit.c index cfba99b..2b4c15a 100644 --- a/net/ipv6/sit.c +++ b/net/ipv6/sit.c @@ -590,6 +590,22 @@ out: return err; } +static int sit_chksrc(struct ip_tunnel *tunnel, const __be32 *addr, + const struct in6_addr *addr6) +{ +#ifdef CONFIG_IPV6_SIT_6RD + if (ipv6_prefix_equal(addr6, &tunnel->ip6rd.prefix, + tunnel->ip6rd.prefixlen) && + memcmp(addr, &addr6->s6_addr16[1], 4)) + return 0; +#else + if (addr6->s6_addr16[0] == htons(0x2002) && + memcmp(addr, &addr6->s6_addr16[1], 4)) + return 0; +#endif + return 1; +} + static int ipip6_rcv(struct sk_buff *skb) { const struct iphdr *iph; @@ -613,8 +629,15 @@ static int ipip6_rcv(struct sk_buff *skb) skb->protocol = htons(ETH_P_IPV6); skb->pkt_type = PACKET_HOST; - if ((tunnel->dev->priv_flags & IFF_ISATAP) && - !isatap_chksrc(skb, iph, tunnel)) { + if (tunnel->dev->priv_flags & IFF_ISATAP) { + if (!isatap_chksrc(skb, iph, tunnel)) { + tunnel->dev->stats.rx_errors++; + goto out; + } + } else if (!sit_chksrc(tunnel, &iph->saddr, + &ipv6_hdr(skb)->saddr) || + !sit_chksrc(tunnel, &iph->daddr, + &ipv6_hdr(skb)->daddr)) { tunnel->dev->stats.rx_errors++; goto out; }
This patch adds anti-spoofing checks in sit.c as specified in RFC3964 section 5.2 for 6to4 and RFC5969 section 12 for 6rd. I left out the checks which could easily be implemented with netfilter. Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org> --- net/ipv6/sit.c | 27 +++++++++++++++++++++++++-- 1 file changed, 25 insertions(+), 2 deletions(-)