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* [PATCH nf-next] netfilter: ftp: Remove the useless dlen==0 condition check in find_pattern
@ 2016-09-01  2:14 fgao
  2016-09-01  2:26 ` Feng Gao
  0 siblings, 1 reply; 5+ messages in thread
From: fgao @ 2016-09-01  2:14 UTC (permalink / raw)
  To: pablo, kadlec, netfilter-devel, coreteam; +Cc: gfree.wind, Gao Feng

From: Gao Feng <fgao@ikuai8.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@ikuai8.com>
---
 net/netfilter/nf_conntrack_ftp.c | 12 ------------
 1 file changed, 12 deletions(-)

diff --git a/net/netfilter/nf_conntrack_ftp.c b/net/netfilter/nf_conntrack_ftp.c
index b6934b5..77f05ac 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? */
@@ -312,16 +310,6 @@ static int find_pattern(const char *data, size_t dlen,
 	}
 
 	if (strncasecmp(data, pattern, plen) != 0) {
-#if 0
-		size_t i;
-
-		pr_debug("ftp: string mismatch\n");
-		for (i = 0; i < plen; i++) {
-			pr_debug("ftp:char %u `%c'(%u) vs `%c'(%u)\n",
-				 i, data[i], data[i],
-				 pattern[i], pattern[i]);
-		}
-#endif
 		return 0;
 	}
 
-- 
1.9.1



^ permalink raw reply related	[flat|nested] 5+ messages in thread

end of thread, other threads:[~2016-09-01 11:08 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2016-09-01  2:14 [PATCH nf-next] netfilter: ftp: Remove the useless dlen==0 condition check in find_pattern fgao
2016-09-01  2:26 ` Feng Gao
2016-09-01 10:20   ` Pablo Neira Ayuso
2016-09-01 11:01     ` Feng Gao
2016-09-01 11:08       ` Pablo Neira Ayuso

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