Patchwork [v2,5/8] net/ipv4/netfilter/nf_nat_ftp.c: Remove (*mangle[]) array and functions, use %pI4

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Submitter Joe Perches
Date Jan. 6, 2010, 7:23 p.m.
Message ID <1262805798.1952.105.camel@Joe-Laptop.home>
Download mbox | patch
Permalink /patch/42320/
State Not Applicable
Delegated to: David Miller
Headers show

Comments

Joe Perches - Jan. 6, 2010, 7:23 p.m.
These functions merely exist to format a buffer and call
nf_nat_mangle_tcp_packet.

Format the buffer and perform the call in nf_nat_ftp instead.

Use %pI4 for the IP address.

Saves ~600 bytes of text

old:
$ size net/ipv4/netfilter/nf_nat_ftp.o
   text	   data	    bss	    dec	    hex	filename
   2187	    160	    408	   2755	    ac3	net/ipv4/netfilter/nf_nat_ftp.o
new:
$ size net/ipv4/netfilter/nf_nat_ftp.o
   text    data     bss     dec     hex filename
   1532     112     288    1932     78c net/ipv4/netfilter/nf_nat_ftp.o

Signed-off-by: Joe Perches <joe@perches.com>

 net/ipv4/netfilter/nf_nat_ftp.c |  105 +++++++++++++--------------------------
 1 files changed, 35 insertions(+), 70 deletions(-)



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Patrick McHardy - Jan. 11, 2010, 10:51 a.m.
Joe Perches wrote:
> These functions merely exist to format a buffer and call
> nf_nat_mangle_tcp_packet.
> 
> Format the buffer and perform the call in nf_nat_ftp instead.
> 
> Use %pI4 for the IP address.
> 
> Saves ~600 bytes of text
> 
> old:
> $ size net/ipv4/netfilter/nf_nat_ftp.o
>    text	   data	    bss	    dec	    hex	filename
>    2187	    160	    408	   2755	    ac3	net/ipv4/netfilter/nf_nat_ftp.o
> new:
> $ size net/ipv4/netfilter/nf_nat_ftp.o
>    text    data     bss     dec     hex filename
>    1532     112     288    1932     78c net/ipv4/netfilter/nf_nat_ftp.o

Applied, thanks. BTW, its enough to CC netfilter-devel and optionally
netdev on patches, netfilter and netfilter-core are unnecessary.

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Patch

diff --git a/net/ipv4/netfilter/nf_nat_ftp.c b/net/ipv4/netfilter/nf_nat_ftp.c
index a1d5d58..86e0e84 100644
--- a/net/ipv4/netfilter/nf_nat_ftp.c
+++ b/net/ipv4/netfilter/nf_nat_ftp.c
@@ -27,76 +27,29 @@  MODULE_ALIAS("ip_nat_ftp");
 
 /* FIXME: Time out? --RR */
 
-static int
-mangle_rfc959_packet(struct sk_buff *skb,
-		     __be32 newip,
-		     u_int16_t port,
-		     unsigned int matchoff,
-		     unsigned int matchlen,
-		     struct nf_conn *ct,
-		     enum ip_conntrack_info ctinfo)
+static int nf_nat_ftp_fmt_cmd(enum nf_ct_ftp_type type,
+			      char *buffer, size_t buflen,
+			      __be32 addr, u16 port)
 {
-	char buffer[sizeof("nnn,nnn,nnn,nnn,nnn,nnn")];
-
-	sprintf(buffer, "%u,%u,%u,%u,%u,%u",
-		NIPQUAD(newip), port>>8, port&0xFF);
-
-	pr_debug("calling nf_nat_mangle_tcp_packet\n");
-
-	return nf_nat_mangle_tcp_packet(skb, ct, ctinfo, matchoff,
-					matchlen, buffer, strlen(buffer));
-}
-
-/* |1|132.235.1.2|6275| */
-static int
-mangle_eprt_packet(struct sk_buff *skb,
-		   __be32 newip,
-		   u_int16_t port,
-		   unsigned int matchoff,
-		   unsigned int matchlen,
-		   struct nf_conn *ct,
-		   enum ip_conntrack_info ctinfo)
-{
-	char buffer[sizeof("|1|255.255.255.255|65535|")];
-
-	sprintf(buffer, "|1|%u.%u.%u.%u|%u|", NIPQUAD(newip), port);
-
-	pr_debug("calling nf_nat_mangle_tcp_packet\n");
-
-	return nf_nat_mangle_tcp_packet(skb, ct, ctinfo, matchoff,
-					matchlen, buffer, strlen(buffer));
-}
-
-/* |1|132.235.1.2|6275| */
-static int
-mangle_epsv_packet(struct sk_buff *skb,
-		   __be32 newip,
-		   u_int16_t port,
-		   unsigned int matchoff,
-		   unsigned int matchlen,
-		   struct nf_conn *ct,
-		   enum ip_conntrack_info ctinfo)
-{
-	char buffer[sizeof("|||65535|")];
-
-	sprintf(buffer, "|||%u|", port);
-
-	pr_debug("calling nf_nat_mangle_tcp_packet\n");
+	switch (type) {
+	case NF_CT_FTP_PORT:
+	case NF_CT_FTP_PASV:
+		return snprintf(buffer, buflen, "%u,%u,%u,%u,%u,%u",
+				((unsigned char *)&addr)[0],
+				((unsigned char *)&addr)[1],
+				((unsigned char *)&addr)[2],
+				((unsigned char *)&addr)[3],
+				port >> 8,
+				port & 0xFF);
+	case NF_CT_FTP_EPRT:
+		return snprintf(buffer, buflen, "|1|%pI4|%u|", &addr, port);
+	case NF_CT_FTP_EPSV:
+		return snprintf(buffer, buflen, "|||%u|", port);
+	}
 
-	return nf_nat_mangle_tcp_packet(skb, ct, ctinfo, matchoff,
-					matchlen, buffer, strlen(buffer));
+	return 0;
 }
 
-static int (*mangle[])(struct sk_buff *, __be32, u_int16_t,
-		       unsigned int, unsigned int, struct nf_conn *,
-		       enum ip_conntrack_info)
-= {
-	[NF_CT_FTP_PORT] = mangle_rfc959_packet,
-	[NF_CT_FTP_PASV] = mangle_rfc959_packet,
-	[NF_CT_FTP_EPRT] = mangle_eprt_packet,
-	[NF_CT_FTP_EPSV] = mangle_epsv_packet
-};
-
 /* So, this packet has hit the connection tracking matching code.
    Mangle it, and change the expectation to match the new version. */
 static unsigned int nf_nat_ftp(struct sk_buff *skb,
@@ -110,6 +63,8 @@  static unsigned int nf_nat_ftp(struct sk_buff *skb,
 	u_int16_t port;
 	int dir = CTINFO2DIR(ctinfo);
 	struct nf_conn *ct = exp->master;
+	char buffer[sizeof("|1|255.255.255.255|65535|")];
+	unsigned int buflen;
 
 	pr_debug("FTP_NAT: type %i, off %u len %u\n", type, matchoff, matchlen);
 
@@ -132,11 +87,21 @@  static unsigned int nf_nat_ftp(struct sk_buff *skb,
 	if (port == 0)
 		return NF_DROP;
 
-	if (!mangle[type](skb, newip, port, matchoff, matchlen, ct, ctinfo)) {
-		nf_ct_unexpect_related(exp);
-		return NF_DROP;
-	}
+	buflen = nf_nat_ftp_fmt_cmd(type, buffer, sizeof(buffer), newip, port);
+	if (!buflen)
+		goto out;
+
+	pr_debug("calling nf_nat_mangle_tcp_packet\n");
+
+	if (!nf_nat_mangle_tcp_packet(skb, ct, ctinfo, matchoff,
+				      matchlen, buffer, buflen))
+		goto out;
+
 	return NF_ACCEPT;
+
+out:
+	nf_ct_unexpect_related(exp);
+	return NF_DROP;
 }
 
 static void __exit nf_nat_ftp_fini(void)