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>

1 files changed, 35 insertions, 70 deletions

diff --git a/net/ipv4/netfilter/nf_nat_ftp.c b/net/ipv4/netfilter/nf_nat_ftp.c
index a1d5d58a58bf..86e0e84ff0a0 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)