net: Fix routing tables with id > 255 for legacy software

Most legacy software do not like tables > 255 as rtm_table is u8 so tb_id is sent &0xff and it is possible to mismatch for example table 510 with table 254 (main). This patch introduces RT_TABLE_COMPAT=252 so the code uses it if tb_id > 255. It makes such old applications happy, new ones are still able to use RTA_TABLE to get a proper table id. Signed-off-by: Krzysztof Piotr Oledzki <[email protected]> Acked-by: Patrick McHardy <[email protected]> Signed-off-by: David S. Miller <[email protected]>
crow-misia · Jun 10, 2008 · 709772e · 709772e
1 parent 99c6f60
commit 709772e
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Showing 2 changed files with 5 additions and 1 deletion.
diff --git a/include/linux/rtnetlink.h b/include/linux/rtnetlink.h
@@ -246,6 +246,7 @@ enum rt_class_t
 {
 	RT_TABLE_UNSPEC=0,
 /* User defined values */
+	RT_TABLE_COMPAT=252,
 	RT_TABLE_DEFAULT=253,
 	RT_TABLE_MAIN=254,
 	RT_TABLE_LOCAL=255,

diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c
@@ -960,7 +960,10 @@ int fib_dump_info(struct sk_buff *skb, u32 pid, u32 seq, int event,
 	rtm->rtm_dst_len = dst_len;
 	rtm->rtm_src_len = 0;
 	rtm->rtm_tos = tos;
-	rtm->rtm_table = tb_id;
+	if (tb_id < 256)
+		rtm->rtm_table = tb_id;
+	else
+		rtm->rtm_table = RT_TABLE_COMPAT;
 	NLA_PUT_U32(skb, RTA_TABLE, tb_id);
 	rtm->rtm_type = type;
 	rtm->rtm_flags = fi->fib_flags;