netfilter 06/62: nf_nat_ftp: remove (*mangle[]) array and functions, use %pI4

Patrick McHardy
2010-02-16T14:55:28Z

commit c299bd53aa2616e6afc304b4f848186af3b3a881
Author: Joe Perches <joe@perches.com>
Date: Mon Jan 11 11:49:51 2010 +0100

netfilter: nf_nat_ftp: remove (*mangle[]) array and functions, use %pI4

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>
Signed-off-by: Patrick McHardy <kaber@trash.net>

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)