[PATCH] net: ipv4: fix table id in getroute response

[PATCH] net: ipv4: fix table id in getroute response

[David Ahern]

rtm_table is an 8-bit field while table ids are allowed up to u32. Commit
709772e6e065 ("net: Fix routing tables with id > 255 for legacy software")
added the preference to set rtm_table in dumps to RT_TABLE_COMPAT if the
table id is > 255. The table id returned on get route requests should do
the same.

Fixes: c36ba6603a11 ("net: Allow user to get table id from route lookup")
Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
---
 net/ipv4/route.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 0fcac8e7a2b2..709ffe67d1de 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -2472,7 +2472,7 @@ static int rt_fill_info(struct net *net,  __be32 dst, __be32 src, u32 table_id,
 	r->rtm_dst_len	= 32;
 	r->rtm_src_len	= 0;
 	r->rtm_tos	= fl4->flowi4_tos;
-	r->rtm_table	= table_id;
+	r->rtm_table	= table_id < 256 ? table_id : RT_TABLE_COMPAT;
 	if (nla_put_u32(skb, RTA_TABLE, table_id))
 		goto nla_put_failure;
 	r->rtm_type	= rt->rt_type;
-- 
2.1.4

Re: [PATCH] net: ipv4: fix table id in getroute response

[David Miller]

From: David Ahern <dsa@cumulusnetworks.com>
Date: Wed, 11 Jan 2017 15:42:17 -0800

> rtm_table is an 8-bit field while table ids are allowed up to u32. Commit
> 709772e6e065 ("net: Fix routing tables with id > 255 for legacy software")
> added the preference to set rtm_table in dumps to RT_TABLE_COMPAT if the
> table id is > 255. The table id returned on get route requests should do
> the same.
> 
> Fixes: c36ba6603a11 ("net: Allow user to get table id from route lookup")
> Signed-off-by: David Ahern <dsa@cumulusnetworks.com>

Good catch, applied and queued up for -stable.