ipv4/route: Allow NULL flowinfo in rt_fill_info()

In the next patch, we're going to use rt_fill_info() to dump exception
routes upon RTM_GETROUTE with NLM_F_ROOT, meaning userspace is requesting
a dump and not a specific route selection, which in turn implies the input
interface is not relevant. Update rt_fill_info() to handle a NULL
flowinfo.

v7: If fl4 is NULL, explicitly set r->rtm_tos to 0: it's not initialised
    otherwise (spotted by David Ahern)

v6: New patch

Suggested-by: David Ahern <dsahern@gmail.com>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Stefano Brivio 2019-06-21 17:45:22 +02:00 committed by David S. Miller
parent b597ca6e83
commit d948974ccc

View file

@ -2699,7 +2699,7 @@ static int rt_fill_info(struct net *net, __be32 dst, __be32 src,
r->rtm_family = AF_INET;
r->rtm_dst_len = 32;
r->rtm_src_len = 0;
r->rtm_tos = fl4->flowi4_tos;
r->rtm_tos = fl4 ? fl4->flowi4_tos : 0;
r->rtm_table = table_id < 256 ? table_id : RT_TABLE_COMPAT;
if (nla_put_u32(skb, RTA_TABLE, table_id))
goto nla_put_failure;
@ -2727,7 +2727,7 @@ static int rt_fill_info(struct net *net, __be32 dst, __be32 src,
nla_put_u32(skb, RTA_FLOW, rt->dst.tclassid))
goto nla_put_failure;
#endif
if (!rt_is_input_route(rt) &&
if (fl4 && !rt_is_input_route(rt) &&
fl4->saddr != src) {
if (nla_put_in_addr(skb, RTA_PREFSRC, fl4->saddr))
goto nla_put_failure;
@ -2767,20 +2767,21 @@ static int rt_fill_info(struct net *net, __be32 dst, __be32 src,
if (rtnetlink_put_metrics(skb, metrics) < 0)
goto nla_put_failure;
if (fl4) {
if (fl4->flowi4_mark &&
nla_put_u32(skb, RTA_MARK, fl4->flowi4_mark))
goto nla_put_failure;
if (!uid_eq(fl4->flowi4_uid, INVALID_UID) &&
nla_put_u32(skb, RTA_UID,
from_kuid_munged(current_user_ns(), fl4->flowi4_uid)))
from_kuid_munged(current_user_ns(),
fl4->flowi4_uid)))
goto nla_put_failure;
error = rt->dst.error;
if (rt_is_input_route(rt)) {
#ifdef CONFIG_IP_MROUTE
if (ipv4_is_multicast(dst) && !ipv4_is_local_multicast(dst) &&
if (ipv4_is_multicast(dst) &&
!ipv4_is_local_multicast(dst) &&
IPV4_DEVCONF_ALL(net, MC_FORWARDING)) {
int err = ipmr_get_route(net, skb,
fl4->saddr, fl4->daddr,
@ -2796,6 +2797,9 @@ static int rt_fill_info(struct net *net, __be32 dst, __be32 src,
if (nla_put_u32(skb, RTA_IIF, fl4->flowi4_iif))
goto nla_put_failure;
}
}
error = rt->dst.error;
if (rtnl_put_cacheinfo(skb, &rt->dst, 0, expires, error) < 0)
goto nla_put_failure;