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 a1d5d58a58bf904b25115fe8dff4397e4d541a29..86e0e84ff0a04fe09cd3b5d67dddcf93457ffa15 100644 (file)
--- 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)