#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 unsigned short ports[MAX_PORTS];
static int ports_c;
-MODULE_PARM(ports, "1-" __MODULE_STRING(MAX_PORTS) "i");
+module_param_array(ports, ushort, &ports_c, 0400);
MODULE_PARM_DESC(ports, "port numbers of tftp servers");
#if 0
#define DEBUGP(format, args...)
#endif
-static int tftp_help(struct sk_buff *skb,
+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;
+ struct tftphdr _tftph, *tfh;
struct ip_conntrack_expect *exp;
+ unsigned int ret = NF_ACCEPT;
+ typeof(ip_nat_tftp_hook) ip_nat_tftp;
- if (skb_copy_bits(skb, skb->nh.iph->ihl * 4 + sizeof(struct udphdr),
- &tftph, sizeof(tftph)) != 0)
+ tfh = skb_header_pointer(*pskb,
+ (*pskb)->nh.iph->ihl*4+sizeof(struct udphdr),
+ sizeof(_tftph), &_tftph);
+ if (tfh == NULL)
return NF_ACCEPT;
- switch (ntohs(tftph.opcode)) {
+ switch (ntohs(tfh->opcode)) {
/* RRQ and WRQ works the same way */
case TFTP_OPCODE_READ:
case TFTP_OPCODE_WRITE:
DUMP_TUPLE(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
DUMP_TUPLE(&ct->tuplehash[IP_CT_DIR_REPLY].tuple);
- exp = ip_conntrack_expect_alloc();
+ exp = ip_conntrack_expect_alloc(ct);
if (exp == NULL)
- return NF_ACCEPT;
+ 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 = 0xffff;
+ exp->mask.src.ip = htonl(0xffffffff);
+ exp->mask.src.u.udp.port = 0;
+ exp->mask.dst.ip = htonl(0xffffffff);
+ exp->mask.dst.u.udp.port = htons(0xffff);
+ exp->mask.dst.protonum = 0xff;
exp->expectfn = NULL;
+ exp->flags = 0;
DEBUGP("expect: ");
DUMP_TUPLE(&exp->tuple);
DUMP_TUPLE(&exp->mask);
- ip_conntrack_expect_related(exp, ct);
+ ip_nat_tftp = rcu_dereference(ip_nat_tftp_hook);
+ if (ip_nat_tftp)
+ ret = ip_nat_tftp(pskb, ctinfo, exp);
+ else if (ip_conntrack_expect_related(exp) != 0)
+ ret = NF_DROP;
+ ip_conntrack_expect_put(exp);
break;
case TFTP_OPCODE_DATA:
case TFTP_OPCODE_ACK:
}
static struct ip_conntrack_helper tftp[MAX_PORTS];
-static char tftp_names[MAX_PORTS][10];
+static char tftp_names[MAX_PORTS][sizeof("tftp-65535")];
-static void fini(void)
+static void ip_conntrack_tftp_fini(void)
{
int i;
}
}
-static int __init init(void)
+static int __init ip_conntrack_tftp_init(void)
{
int i, ret;
char *tmpname;
- if (!ports[0])
- ports[0]=TFTP_PORT;
+ if (ports_c == 0)
+ ports[ports_c++] = TFTP_PORT;
- for (i = 0 ; (i < MAX_PORTS) && ports[i] ; i++) {
+ 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 = 0xFFFF;
- tftp[i].mask.src.u.udp.port = 0xFFFF;
+ tftp[i].mask.dst.protonum = 0xFF;
+ tftp[i].mask.src.u.udp.port = htons(0xFFFF);
tftp[i].max_expected = 1;
- tftp[i].timeout = 0;
- tftp[i].flags = IP_CT_HELPER_F_REUSE_EXPECT;
+ tftp[i].timeout = 5 * 60; /* 5 minutes */
tftp[i].me = THIS_MODULE;
tftp[i].help = tftp_help;
if (ret) {
printk("ERROR registering helper for port %d\n",
ports[i]);
- fini();
+ ip_conntrack_tftp_fini();
return(ret);
}
- ports_c++;
}
return(0);
}
-PROVIDES_CONNTRACK(tftp);
-
-module_init(init);
-module_exit(fini);
+module_init(ip_conntrack_tftp_init);
+module_exit(ip_conntrack_tftp_fini);