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Diffstat (limited to 'net/ipv4/netfilter/ip_conntrack_tftp.c')
-rw-r--r--net/ipv4/netfilter/ip_conntrack_tftp.c159
1 files changed, 159 insertions, 0 deletions
diff --git a/net/ipv4/netfilter/ip_conntrack_tftp.c b/net/ipv4/netfilter/ip_conntrack_tftp.c
new file mode 100644
index 00000000000..992fac3e36e
--- /dev/null
+++ b/net/ipv4/netfilter/ip_conntrack_tftp.c
@@ -0,0 +1,159 @@
+/* (C) 2001-2002 Magnus Boden <mb@ozaba.mine.nu>
+ *
+ * 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.
+ *
+ * Version: 0.0.7
+ *
+ * Thu 21 Mar 2002 Harald Welte <laforge@gnumonks.org>
+ * - port to newnat API
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/ip.h>
+#include <linux/udp.h>
+
+#include <linux/netfilter.h>
+#include <linux/netfilter_ipv4/ip_tables.h>
+#include <linux/netfilter_ipv4/ip_conntrack_helper.h>
+#include <linux/netfilter_ipv4/ip_conntrack_tftp.h>
+#include <linux/moduleparam.h>
+
+MODULE_AUTHOR("Magnus Boden <mb@ozaba.mine.nu>");
+MODULE_DESCRIPTION("tftp connection tracking helper");
+MODULE_LICENSE("GPL");
+
+#define MAX_PORTS 8
+static int ports[MAX_PORTS];
+static int ports_c;
+module_param_array(ports, int, &ports_c, 0400);
+MODULE_PARM_DESC(ports, "port numbers of tftp servers");
+
+#if 0
+#define DEBUGP(format, args...) printk("%s:%s:" format, \
+ __FILE__, __FUNCTION__ , ## args)
+#else
+#define DEBUGP(format, args...)
+#endif
+
+unsigned int (*ip_nat_tftp_hook)(struct sk_buff **pskb,
+ enum ip_conntrack_info ctinfo,
+ struct ip_conntrack_expect *exp);
+EXPORT_SYMBOL_GPL(ip_nat_tftp_hook);
+
+static int tftp_help(struct sk_buff **pskb,
+ struct ip_conntrack *ct,
+ enum ip_conntrack_info ctinfo)
+{
+ struct tftphdr _tftph, *tfh;
+ struct ip_conntrack_expect *exp;
+ unsigned int ret = NF_ACCEPT;
+
+ tfh = skb_header_pointer(*pskb,
+ (*pskb)->nh.iph->ihl*4+sizeof(struct udphdr),
+ sizeof(_tftph), &_tftph);
+ if (tfh == NULL)
+ return NF_ACCEPT;
+
+ switch (ntohs(tfh->opcode)) {
+ /* RRQ and WRQ works the same way */
+ case TFTP_OPCODE_READ:
+ case TFTP_OPCODE_WRITE:
+ DEBUGP("");
+ DUMP_TUPLE(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
+ DUMP_TUPLE(&ct->tuplehash[IP_CT_DIR_REPLY].tuple);
+
+ exp = ip_conntrack_expect_alloc();
+ if (exp == NULL)
+ return NF_DROP;
+
+ exp->tuple = ct->tuplehash[IP_CT_DIR_REPLY].tuple;
+ exp->mask.src.ip = 0xffffffff;
+ exp->mask.dst.ip = 0xffffffff;
+ exp->mask.dst.u.udp.port = 0xffff;
+ exp->mask.dst.protonum = 0xff;
+ exp->expectfn = NULL;
+ exp->master = ct;
+
+ DEBUGP("expect: ");
+ DUMP_TUPLE(&exp->tuple);
+ DUMP_TUPLE(&exp->mask);
+ if (ip_nat_tftp_hook)
+ ret = ip_nat_tftp_hook(pskb, ctinfo, exp);
+ else if (ip_conntrack_expect_related(exp) != 0) {
+ ip_conntrack_expect_free(exp);
+ ret = NF_DROP;
+ }
+ break;
+ case TFTP_OPCODE_DATA:
+ case TFTP_OPCODE_ACK:
+ DEBUGP("Data/ACK opcode\n");
+ break;
+ case TFTP_OPCODE_ERROR:
+ DEBUGP("Error opcode\n");
+ break;
+ default:
+ DEBUGP("Unknown opcode\n");
+ }
+ return NF_ACCEPT;
+}
+
+static struct ip_conntrack_helper tftp[MAX_PORTS];
+static char tftp_names[MAX_PORTS][10];
+
+static void fini(void)
+{
+ int i;
+
+ for (i = 0 ; i < ports_c; i++) {
+ DEBUGP("unregistering helper for port %d\n",
+ ports[i]);
+ ip_conntrack_helper_unregister(&tftp[i]);
+ }
+}
+
+static int __init init(void)
+{
+ int i, ret;
+ char *tmpname;
+
+ if (ports_c == 0)
+ ports[ports_c++] = TFTP_PORT;
+
+ for (i = 0; i < ports_c; i++) {
+ /* Create helper structure */
+ memset(&tftp[i], 0, sizeof(struct ip_conntrack_helper));
+
+ tftp[i].tuple.dst.protonum = IPPROTO_UDP;
+ tftp[i].tuple.src.u.udp.port = htons(ports[i]);
+ tftp[i].mask.dst.protonum = 0xFF;
+ tftp[i].mask.src.u.udp.port = 0xFFFF;
+ tftp[i].max_expected = 1;
+ tftp[i].timeout = 5 * 60; /* 5 minutes */
+ tftp[i].me = THIS_MODULE;
+ tftp[i].help = tftp_help;
+
+ tmpname = &tftp_names[i][0];
+ if (ports[i] == TFTP_PORT)
+ sprintf(tmpname, "tftp");
+ else
+ sprintf(tmpname, "tftp-%d", i);
+ tftp[i].name = tmpname;
+
+ DEBUGP("port #%d: %d\n", i, ports[i]);
+
+ ret=ip_conntrack_helper_register(&tftp[i]);
+ if (ret) {
+ printk("ERROR registering helper for port %d\n",
+ ports[i]);
+ fini();
+ return(ret);
+ }
+ }
+ return(0);
+}
+
+module_init(init);
+module_exit(fini);