From f6c53334d6c6ac7088c2e7e70ff2941bfb33f52e Mon Sep 17 00:00:00 2001 From: Junwei Zhang Date: Fri, 18 Sep 2015 00:00:05 -0400 Subject: [PATCH] net: only check perm protocol when register proto The permanent protocol nodes are at the head of the list, So only need check all these nodes. No matter the new node is permanent or not, insert the new node after the last permanent protocol node, If the new node conflicts with existing permanent node, return error. Signed-off-by: Martin Zhang Signed-off-by: David S. Miller --- net/ipv4/af_inet.c | 16 +++++----------- 1 file changed, 5 insertions(+), 11 deletions(-) diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c index 1d0c3adb6f34..8a556643b874 100644 --- a/net/ipv4/af_inet.c +++ b/net/ipv4/af_inet.c @@ -1043,22 +1043,16 @@ void inet_register_protosw(struct inet_protosw *p) goto out_illegal; /* If we are trying to override a permanent protocol, bail. */ - answer = NULL; last_perm = &inetsw[p->type]; list_for_each(lh, &inetsw[p->type]) { answer = list_entry(lh, struct inet_protosw, list); - /* Check only the non-wild match. */ - if (INET_PROTOSW_PERMANENT & answer->flags) { - if (protocol == answer->protocol) - break; - last_perm = lh; - } - - answer = NULL; + if ((INET_PROTOSW_PERMANENT & answer->flags) == 0) + break; + if (protocol == answer->protocol) + goto out_permanent; + last_perm = lh; } - if (answer) - goto out_permanent; /* Add the new entry after the last permanent entry if any, so that * the new entry does not override a permanent entry when matched with -- 2.20.1