Add the rt linux 4.1.3-rt3 as base

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

diff --git a/kernel/net/netfilter/nf_conntrack_tftp.c b/kernel/net/netfilter/nf_conntrack_tftp.c
new file mode 100644 (file)
index 0000000..e68ab4f
--- /dev/null
+++ b/kernel/net/netfilter/nf_conntrack_tftp.c
@@ -0,0 +1,153 @@
+/* (C) 2001-2002 Magnus Boden <mb@ozaba.mine.nu>
+ * (C) 2006-2012 Patrick McHardy <kaber@trash.net>
+ * 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/in.h>
+#include <linux/udp.h>
+#include <linux/netfilter.h>
+
+#include <net/netfilter/nf_conntrack.h>
+#include <net/netfilter/nf_conntrack_tuple.h>
+#include <net/netfilter/nf_conntrack_expect.h>
+#include <net/netfilter/nf_conntrack_ecache.h>
+#include <net/netfilter/nf_conntrack_helper.h>
+#include <linux/netfilter/nf_conntrack_tftp.h>
+
+MODULE_AUTHOR("Magnus Boden <mb@ozaba.mine.nu>");
+MODULE_DESCRIPTION("TFTP connection tracking helper");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("ip_conntrack_tftp");
+MODULE_ALIAS_NFCT_HELPER("tftp");
+
+#define MAX_PORTS 8
+static unsigned short ports[MAX_PORTS];
+static unsigned int ports_c;
+module_param_array(ports, ushort, &ports_c, 0400);
+MODULE_PARM_DESC(ports, "Port numbers of TFTP servers");
+
+unsigned int (*nf_nat_tftp_hook)(struct sk_buff *skb,
+                                enum ip_conntrack_info ctinfo,
+                                struct nf_conntrack_expect *exp) __read_mostly;
+EXPORT_SYMBOL_GPL(nf_nat_tftp_hook);
+
+static int tftp_help(struct sk_buff *skb,
+                    unsigned int protoff,
+                    struct nf_conn *ct,
+                    enum ip_conntrack_info ctinfo)
+{
+       const struct tftphdr *tfh;
+       struct tftphdr _tftph;
+       struct nf_conntrack_expect *exp;
+       struct nf_conntrack_tuple *tuple;
+       unsigned int ret = NF_ACCEPT;
+       typeof(nf_nat_tftp_hook) nf_nat_tftp;
+
+       tfh = skb_header_pointer(skb, protoff + sizeof(struct udphdr),
+                                sizeof(_tftph), &_tftph);
+       if (tfh == NULL)
+               return NF_ACCEPT;
+
+       switch (ntohs(tfh->opcode)) {
+       case TFTP_OPCODE_READ:
+       case TFTP_OPCODE_WRITE:
+               /* RRQ and WRQ works the same way */
+               nf_ct_dump_tuple(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
+               nf_ct_dump_tuple(&ct->tuplehash[IP_CT_DIR_REPLY].tuple);
+
+               exp = nf_ct_expect_alloc(ct);
+               if (exp == NULL) {
+                       nf_ct_helper_log(skb, ct, "cannot alloc expectation");
+                       return NF_DROP;
+               }
+               tuple = &ct->tuplehash[IP_CT_DIR_REPLY].tuple;
+               nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT,
+                                 nf_ct_l3num(ct),
+                                 &tuple->src.u3, &tuple->dst.u3,
+                                 IPPROTO_UDP, NULL, &tuple->dst.u.udp.port);
+
+               pr_debug("expect: ");
+               nf_ct_dump_tuple(&exp->tuple);
+
+               nf_nat_tftp = rcu_dereference(nf_nat_tftp_hook);
+               if (nf_nat_tftp && ct->status & IPS_NAT_MASK)
+                       ret = nf_nat_tftp(skb, ctinfo, exp);
+               else if (nf_ct_expect_related(exp) != 0) {
+                       nf_ct_helper_log(skb, ct, "cannot add expectation");
+                       ret = NF_DROP;
+               }
+               nf_ct_expect_put(exp);
+               break;
+       case TFTP_OPCODE_DATA:
+       case TFTP_OPCODE_ACK:
+               pr_debug("Data/ACK opcode\n");
+               break;
+       case TFTP_OPCODE_ERROR:
+               pr_debug("Error opcode\n");
+               break;
+       default:
+               pr_debug("Unknown opcode\n");
+       }
+       return ret;
+}
+
+static struct nf_conntrack_helper tftp[MAX_PORTS][2] __read_mostly;
+
+static const struct nf_conntrack_expect_policy tftp_exp_policy = {
+       .max_expected   = 1,
+       .timeout        = 5 * 60,
+};
+
+static void nf_conntrack_tftp_fini(void)
+{
+       int i, j;
+
+       for (i = 0; i < ports_c; i++) {
+               for (j = 0; j < 2; j++)
+                       nf_conntrack_helper_unregister(&tftp[i][j]);
+       }
+}
+
+static int __init nf_conntrack_tftp_init(void)
+{
+       int i, j, ret;
+
+       if (ports_c == 0)
+               ports[ports_c++] = TFTP_PORT;
+
+       for (i = 0; i < ports_c; i++) {
+               memset(&tftp[i], 0, sizeof(tftp[i]));
+
+               tftp[i][0].tuple.src.l3num = AF_INET;
+               tftp[i][1].tuple.src.l3num = AF_INET6;
+               for (j = 0; j < 2; j++) {
+                       tftp[i][j].tuple.dst.protonum = IPPROTO_UDP;
+                       tftp[i][j].tuple.src.u.udp.port = htons(ports[i]);
+                       tftp[i][j].expect_policy = &tftp_exp_policy;
+                       tftp[i][j].me = THIS_MODULE;
+                       tftp[i][j].help = tftp_help;
+
+                       if (ports[i] == TFTP_PORT)
+                               sprintf(tftp[i][j].name, "tftp");
+                       else
+                               sprintf(tftp[i][j].name, "tftp-%u", i);
+
+                       ret = nf_conntrack_helper_register(&tftp[i][j]);
+                       if (ret) {
+                               printk(KERN_ERR "nf_ct_tftp: failed to register"
+                                      " helper for pf: %u port: %u\n",
+                                       tftp[i][j].tuple.src.l3num, ports[i]);
+                               nf_conntrack_tftp_fini();
+                               return ret;
+                       }
+               }
+       }
+       return 0;
+}
+
+module_init(nf_conntrack_tftp_init);
+module_exit(nf_conntrack_tftp_fini);