Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / net / netfilter / nf_nat_ftp.c

diff --git a/kernel/net/netfilter/nf_nat_ftp.c b/kernel/net/netfilter/nf_nat_ftp.c
new file mode 100644 (file)
index 0000000..e84a578
--- /dev/null
+++ b/kernel/net/netfilter/nf_nat_ftp.c
@@ -0,0 +1,146 @@
+/* FTP extension for TCP NAT alteration. */
+
+/* (C) 1999-2001 Paul `Rusty' Russell
+ * (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/inet.h>
+#include <linux/tcp.h>
+#include <linux/netfilter_ipv4.h>
+#include <net/netfilter/nf_nat.h>
+#include <net/netfilter/nf_nat_helper.h>
+#include <net/netfilter/nf_conntrack_helper.h>
+#include <net/netfilter/nf_conntrack_expect.h>
+#include <linux/netfilter/nf_conntrack_ftp.h>
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Rusty Russell <rusty@rustcorp.com.au>");
+MODULE_DESCRIPTION("ftp NAT helper");
+MODULE_ALIAS("ip_nat_ftp");
+
+/* FIXME: Time out? --RR */
+
+static int nf_nat_ftp_fmt_cmd(struct nf_conn *ct, enum nf_ct_ftp_type type,
+                             char *buffer, size_t buflen,
+                             union nf_inet_addr *addr, u16 port)
+{
+       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->ip)[0],
+                               ((unsigned char *)&addr->ip)[1],
+                               ((unsigned char *)&addr->ip)[2],
+                               ((unsigned char *)&addr->ip)[3],
+                               port >> 8,
+                               port & 0xFF);
+       case NF_CT_FTP_EPRT:
+               if (nf_ct_l3num(ct) == NFPROTO_IPV4)
+                       return snprintf(buffer, buflen, "|1|%pI4|%u|",
+                                       &addr->ip, port);
+               else
+                       return snprintf(buffer, buflen, "|2|%pI6|%u|",
+                                       &addr->ip6, port);
+       case NF_CT_FTP_EPSV:
+               return snprintf(buffer, buflen, "|||%u|", port);
+       }
+
+       return 0;
+}
+
+/* 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,
+                              enum ip_conntrack_info ctinfo,
+                              enum nf_ct_ftp_type type,
+                              unsigned int protoff,
+                              unsigned int matchoff,
+                              unsigned int matchlen,
+                              struct nf_conntrack_expect *exp)
+{
+       union nf_inet_addr newaddr;
+       u_int16_t port;
+       int dir = CTINFO2DIR(ctinfo);
+       struct nf_conn *ct = exp->master;
+       char buffer[sizeof("|1||65535|") + INET6_ADDRSTRLEN];
+       unsigned int buflen;
+
+       pr_debug("FTP_NAT: type %i, off %u len %u\n", type, matchoff, matchlen);
+
+       /* Connection will come from wherever this packet goes, hence !dir */
+       newaddr = ct->tuplehash[!dir].tuple.dst.u3;
+       exp->saved_proto.tcp.port = exp->tuple.dst.u.tcp.port;
+       exp->dir = !dir;
+
+       /* When you see the packet, we need to NAT it the same as the
+        * this one. */
+       exp->expectfn = nf_nat_follow_master;
+
+       /* Try to get same port: if not, try to change it. */
+       for (port = ntohs(exp->saved_proto.tcp.port); port != 0; port++) {
+               int ret;
+
+               exp->tuple.dst.u.tcp.port = htons(port);
+               ret = nf_ct_expect_related(exp);
+               if (ret == 0)
+                       break;
+               else if (ret != -EBUSY) {
+                       port = 0;
+                       break;
+               }
+       }
+
+       if (port == 0) {
+               nf_ct_helper_log(skb, ct, "all ports in use");
+               return NF_DROP;
+       }
+
+       buflen = nf_nat_ftp_fmt_cmd(ct, type, buffer, sizeof(buffer),
+                                   &newaddr, port);
+       if (!buflen)
+               goto out;
+
+       pr_debug("calling nf_nat_mangle_tcp_packet\n");
+
+       if (!nf_nat_mangle_tcp_packet(skb, ct, ctinfo, protoff, matchoff,
+                                     matchlen, buffer, buflen))
+               goto out;
+
+       return NF_ACCEPT;
+
+out:
+       nf_ct_helper_log(skb, ct, "cannot mangle packet");
+       nf_ct_unexpect_related(exp);
+       return NF_DROP;
+}
+
+static void __exit nf_nat_ftp_fini(void)
+{
+       RCU_INIT_POINTER(nf_nat_ftp_hook, NULL);
+       synchronize_rcu();
+}
+
+static int __init nf_nat_ftp_init(void)
+{
+       BUG_ON(nf_nat_ftp_hook != NULL);
+       RCU_INIT_POINTER(nf_nat_ftp_hook, nf_nat_ftp);
+       return 0;
+}
+
+/* Prior to 2.6.11, we had a ports param.  No longer, but don't break users. */
+static int warn_set(const char *val, struct kernel_param *kp)
+{
+       printk(KERN_INFO KBUILD_MODNAME
+              ": kernel >= 2.6.10 only uses 'ports' for conntrack modules\n");
+       return 0;
+}
+module_param_call(ports, warn_set, NULL, NULL, 0);
+
+module_init(nf_nat_ftp_init);
+module_exit(nf_nat_ftp_fini);