netdev - [PATCH 05/53] netfilter: ftp: Remove the useless dlen==0 condition check in find

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Date:   Mon, 26 Sep 2016 01:06:15 +0200
From:   Pablo Neira Ayuso <pablo@...filter.org>
To:     netfilter-devel@...r.kernel.org
Cc:     davem@...emloft.net, netdev@...r.kernel.org
Subject: [PATCH 05/53] netfilter: ftp: Remove the useless dlen==0 condition check in find_pattern

From: Gao Feng <fgao@...ai8.com>

The caller function "help" has already make sure the datalen could not be zero
before invoke find_pattern as a parameter by the following codes

        if (dataoff >= skb->len) {
                pr_debug("ftp: dataoff(%u) >= skblen(%u)\n", dataoff,
                         skb->len);
                return NF_ACCEPT;
        }
        datalen = skb->len - dataoff;

And the latter codes "ends_in_nl = (fb_ptr[datalen - 1] == '\n');" use datalen
directly without checking if it is zero.

So it is unneccessary to check it in find_pattern too.

Signed-off-by: Gao Feng <fgao@...ai8.com>
Signed-off-by: Pablo Neira Ayuso <pablo@...filter.org>
---
 net/netfilter/nf_conntrack_ftp.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/net/netfilter/nf_conntrack_ftp.c b/net/netfilter/nf_conntrack_ftp.c
index b6934b5edf7a..d49a2d410813 100644
--- a/net/netfilter/nf_conntrack_ftp.c
+++ b/net/netfilter/nf_conntrack_ftp.c
@@ -301,8 +301,6 @@ static int find_pattern(const char *data, size_t dlen,
 	size_t i = plen;
 
 	pr_debug("find_pattern `%s': dlen = %Zu\n", pattern, dlen);
-	if (dlen == 0)
-		return 0;
 
 	if (dlen <= plen) {
 		/* Short packet: try for partial? */
-- 
2.1.4