| Message ID | 20240705145302.1717632-3-nicolas.dichtel@6wind.com (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | vrf: fix source address selection with route leak | expand |
On 7/5/24 8:52 AM, Nicolas Dichtel wrote: > diff --git a/include/net/ip6_route.h b/include/net/ip6_route.h > index a18ed24fed94..a7c27f0c6bce 100644 > --- a/include/net/ip6_route.h > +++ b/include/net/ip6_route.h > @@ -127,18 +127,23 @@ void rt6_age_exceptions(struct fib6_info *f6i, struct fib6_gc_args *gc_args, > > static inline int ip6_route_get_saddr(struct net *net, struct fib6_info *f6i, > const struct in6_addr *daddr, > - unsigned int prefs, > + unsigned int prefs, int l3mdev_index, > struct in6_addr *saddr) > { > + struct net_device *l3mdev; > + struct net_device *dev; > + bool same_vrf; > int err = 0; > > - if (f6i && f6i->fib6_prefsrc.plen) { > + rcu_read_lock(); > + l3mdev = dev_get_by_index_rcu(net, l3mdev_index); > + dev = f6i ? fib6_info_nh_dev(f6i) : NULL; > + same_vrf = l3mdev == NULL || l3mdev_master_dev_rcu(dev) == l3mdev; !l3mdev; checkpatch should complain > + if (f6i && f6i->fib6_prefsrc.plen && same_vrf) > *saddr = f6i->fib6_prefsrc.addr; > - } else { > - struct net_device *dev = f6i ? fib6_info_nh_dev(f6i) : NULL; > - > - err = ipv6_dev_get_saddr(net, dev, daddr, prefs, saddr); > - } > + else > + err = ipv6_dev_get_saddr(net, same_vrf ? dev : l3mdev, daddr, prefs, saddr); > + rcu_read_unlock(); > > return err; > } lot of logic lines jammed together. put a new line after the read_lock() and before the unlock().
Le 07/07/2024 à 18:58, David Ahern a écrit : > On 7/5/24 8:52 AM, Nicolas Dichtel wrote: >> diff --git a/include/net/ip6_route.h b/include/net/ip6_route.h >> index a18ed24fed94..a7c27f0c6bce 100644 >> --- a/include/net/ip6_route.h >> +++ b/include/net/ip6_route.h >> @@ -127,18 +127,23 @@ void rt6_age_exceptions(struct fib6_info *f6i, struct fib6_gc_args *gc_args, >> >> static inline int ip6_route_get_saddr(struct net *net, struct fib6_info *f6i, >> const struct in6_addr *daddr, >> - unsigned int prefs, >> + unsigned int prefs, int l3mdev_index, >> struct in6_addr *saddr) >> { >> + struct net_device *l3mdev; >> + struct net_device *dev; >> + bool same_vrf; >> int err = 0; >> >> - if (f6i && f6i->fib6_prefsrc.plen) { >> + rcu_read_lock(); >> + l3mdev = dev_get_by_index_rcu(net, l3mdev_index); >> + dev = f6i ? fib6_info_nh_dev(f6i) : NULL; >> + same_vrf = l3mdev == NULL || l3mdev_master_dev_rcu(dev) == l3mdev; > > !l3mdev; checkpatch should complain No. I was unaware of this preference, is there a rule written somewhere about this? $ git grep '(![a-zA-Z])' net/ipv6/ | wc -l 43 $ git grep '== NULL' net/ipv6/ | wc -l 44 It seems both are used. Regards, Nicolas
On 7/8/24 12:15 PM, Nicolas Dichtel wrote: >> !l3mdev; checkpatch should complain > No. I was unaware of this preference, is there a rule written somewhere about this? checkpatch
Le 08/07/2024 à 20:44, David Ahern a écrit : > On 7/8/24 12:15 PM, Nicolas Dichtel wrote: >>> !l3mdev; checkpatch should complain >> No. I was unaware of this preference, is there a rule written somewhere about this? > > checkpatch > After digging a bit more, I should run checkpatch with '--strict' to get it. Thanks, Nicolas
diff --git a/include/net/ip6_route.h b/include/net/ip6_route.h index a18ed24fed94..a7c27f0c6bce 100644 --- a/include/net/ip6_route.h +++ b/include/net/ip6_route.h @@ -127,18 +127,23 @@ void rt6_age_exceptions(struct fib6_info *f6i, struct fib6_gc_args *gc_args, static inline int ip6_route_get_saddr(struct net *net, struct fib6_info *f6i, const struct in6_addr *daddr, - unsigned int prefs, + unsigned int prefs, int l3mdev_index, struct in6_addr *saddr) { + struct net_device *l3mdev; + struct net_device *dev; + bool same_vrf; int err = 0; - if (f6i && f6i->fib6_prefsrc.plen) { + rcu_read_lock(); + l3mdev = dev_get_by_index_rcu(net, l3mdev_index); + dev = f6i ? fib6_info_nh_dev(f6i) : NULL; + same_vrf = l3mdev == NULL || l3mdev_master_dev_rcu(dev) == l3mdev; + if (f6i && f6i->fib6_prefsrc.plen && same_vrf) *saddr = f6i->fib6_prefsrc.addr; - } else { - struct net_device *dev = f6i ? fib6_info_nh_dev(f6i) : NULL; - - err = ipv6_dev_get_saddr(net, dev, daddr, prefs, saddr); - } + else + err = ipv6_dev_get_saddr(net, same_vrf ? dev : l3mdev, daddr, prefs, saddr); + rcu_read_unlock(); return err; } diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c index 27d8725445e3..784424ac4147 100644 --- a/net/ipv6/ip6_output.c +++ b/net/ipv6/ip6_output.c @@ -1124,6 +1124,7 @@ static int ip6_dst_lookup_tail(struct net *net, const struct sock *sk, from = rt ? rcu_dereference(rt->from) : NULL; err = ip6_route_get_saddr(net, from, &fl6->daddr, sk ? READ_ONCE(inet6_sk(sk)->srcprefs) : 0, + fl6->flowi6_l3mdev, &fl6->saddr); rcu_read_unlock(); diff --git a/net/ipv6/route.c b/net/ipv6/route.c index 8d72ca0b086d..c9a9506b714d 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -5689,7 +5689,7 @@ static int rt6_fill_node(struct net *net, struct sk_buff *skb, goto nla_put_failure; } else if (dest) { struct in6_addr saddr_buf; - if (ip6_route_get_saddr(net, rt, dest, 0, &saddr_buf) == 0 && + if (ip6_route_get_saddr(net, rt, dest, 0, 0, &saddr_buf) == 0 && nla_put_in6_addr(skb, RTA_PREFSRC, &saddr_buf)) goto nla_put_failure; }
By default, an address assigned to the output interface is selected when the source address is not specified. This is problematic when a route, configured in a vrf, uses an interface from another vrf (aka route leak). The original vrf does not own the selected source address. Let's add a check against the output interface and call the appropriate function to select the source address. CC: stable@vger.kernel.org Fixes: 0d240e7811c4 ("net: vrf: Implement get_saddr for IPv6") Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> --- include/net/ip6_route.h | 19 ++++++++++++------- net/ipv6/ip6_output.c | 1 + net/ipv6/route.c | 2 +- 3 files changed, 14 insertions(+), 8 deletions(-)