ipv6: ipv6_find_hdr restore prev functionality

[ Upstream commit accfe0e356327da5bd53da8852b93fc22de9b5fc ]

The commit 9195bb8e381d81d5a315f911904cdf0cfcc919b8 ("ipv6: improve
ipv6_find_hdr() to skip empty routing headers") broke ipv6_find_hdr().

When a target is specified like IPPROTO_ICMPV6 ipv6_find_hdr()
returns -ENOENT when it's found, not the header as expected.

A part of IPVS is broken and possible also nft_exthdr_eval().
When target is -1 which it is most cases, it works.

This patch exits the do while loop if the specific header is found
so the nexthdr could be returned as expected.

Reported-by: Art -kwaak- van Breemen <ard@telegraafnet.nl>
Signed-off-by: Hans Schillstrom <hans@schillstrom.com>
CC:Ansis Atteka <aatteka@nicira.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>

diff --git a/net/ipv6/exthdrs_core.c b/net/ipv6/exthdrs_core.c
index 140748d..8af3eb5 100644 (file)
--- a/net/ipv6/exthdrs_core.c
+++ b/net/ipv6/exthdrs_core.c
@@ -212,7 +212,7 @@ int ipv6_find_hdr(const struct sk_buff *skb, unsigned int *offset,
                found = (nexthdr == target);
 
                if ((!ipv6_ext_hdr(nexthdr)) || nexthdr == NEXTHDR_NONE) {
-                       if (target < 0)
+                       if (target < 0 || found)
                                break;
                        return -ENOENT;
                }