From d948974ccc6613b30636014f76700de3aad7e9b7 Mon Sep 17 00:00:00 2001 From: Stefano Brivio Date: Fri, 21 Jun 2019 17:45:22 +0200 Subject: [PATCH] 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 Signed-off-by: Stefano Brivio Reviewed-by: David Ahern Signed-off-by: David S. Miller --- net/ipv4/route.c | 60 ++++++++++++++++++++++++++---------------------- 1 file changed, 32 insertions(+), 28 deletions(-) diff --git a/net/ipv4/route.c b/net/ipv4/route.c index 66cbe8a7a168..b1628d25e828 100644 --- a/net/ipv4/route.c +++ b/net/ipv4/route.c @@ -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; @@ -2767,36 +2767,40 @@ 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->flowi4_mark && - nla_put_u32(skb, RTA_MARK, fl4->flowi4_mark)) - 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))) - 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))) + goto nla_put_failure; + + if (rt_is_input_route(rt)) { +#ifdef CONFIG_IP_MROUTE + 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, + r, portid); + + if (err <= 0) { + if (err == 0) + return 0; + goto nla_put_failure; + } + } else +#endif + if (nla_put_u32(skb, RTA_IIF, fl4->flowi4_iif)) + 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) && - IPV4_DEVCONF_ALL(net, MC_FORWARDING)) { - int err = ipmr_get_route(net, skb, - fl4->saddr, fl4->daddr, - r, portid); - - if (err <= 0) { - if (err == 0) - return 0; - goto nla_put_failure; - } - } else -#endif - if (nla_put_u32(skb, RTA_IIF, fl4->flowi4_iif)) - goto nla_put_failure; - } - if (rtnl_put_cacheinfo(skb, &rt->dst, 0, expires, error) < 0) goto nla_put_failure;