[GitHub/exynos8895/android_kernel_samsung_universal8895.git] / net / netfilter / nf_conntrack_tftp.c

/* (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.
 */

#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");

#define MAX_PORTS 8
static unsigned short ports[MAX_PORTS];
static 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)
{
	struct tftphdr _tftph, *tfh;
	struct nf_conntrack_expect *exp;
	struct nf_conntrack_tuple *tuple;
	unsigned int ret = NF_ACCEPT;
	int family = ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.l3num;
	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)
			return NF_DROP;
		tuple = &ct->tuplehash[IP_CT_DIR_REPLY].tuple;
		nf_ct_expect_init(exp, family, &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)
			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 char tftp_names[MAX_PORTS][2][sizeof("tftp-65535")] __read_mostly;

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;
	char *tmpname;

	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].max_expected = 1;
			tftp[i][j].timeout = 5 * 60; /* 5 minutes */
			tftp[i][j].me = THIS_MODULE;
			tftp[i][j].help = tftp_help;

			tmpname = &tftp_names[i][j][0];
			if (ports[i] == TFTP_PORT)
				sprintf(tmpname, "tftp");
			else
				sprintf(tmpname, "tftp-%u", i);
			tftp[i][j].name = tmpname;

			ret = nf_conntrack_helper_register(&tftp[i][j]);
			if (ret) {
				printk("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);
Commit	Line	Data
a536df35 PM	1	/* (C) 2001-2002 Magnus Boden <mb@ozaba.mine.nu>
	2	*
	3	* This program is free software; you can redistribute it and/or modify
	4	* it under the terms of the GNU General Public License version 2 as
	5	* published by the Free Software Foundation.
	6	*/
	7
	8	#include <linux/module.h>
	9	#include <linux/moduleparam.h>
	10	#include <linux/in.h>
	11	#include <linux/udp.h>
1863f096	12	#include <linux/netfilter.h>
a536df35 PM	13
	14	#include <net/netfilter/nf_conntrack.h>
	15	#include <net/netfilter/nf_conntrack_tuple.h>
	16	#include <net/netfilter/nf_conntrack_expect.h>
	17	#include <net/netfilter/nf_conntrack_ecache.h>
	18	#include <net/netfilter/nf_conntrack_helper.h>
	19	#include <linux/netfilter/nf_conntrack_tftp.h>
	20
	21	MODULE_AUTHOR("Magnus Boden <mb@ozaba.mine.nu>");
	22	MODULE_DESCRIPTION("TFTP connection tracking helper");
	23	MODULE_LICENSE("GPL");
	24	MODULE_ALIAS("ip_conntrack_tftp");
	25
	26	#define MAX_PORTS 8
	27	static unsigned short ports[MAX_PORTS];
	28	static int ports_c;
	29	module_param_array(ports, ushort, &ports_c, 0400);
	30	MODULE_PARM_DESC(ports, "Port numbers of TFTP servers");
	31
3db05fea	32	unsigned int (nf_nat_tftp_hook)(struct sk_buff skb,
a536df35 PM	33	enum ip_conntrack_info ctinfo,
	34	struct nf_conntrack_expect *exp) __read_mostly;
	35	EXPORT_SYMBOL_GPL(nf_nat_tftp_hook);
	36
3db05fea	37	static int tftp_help(struct sk_buff *skb,
a536df35 PM	38	unsigned int protoff,
	39	struct nf_conn *ct,
	40	enum ip_conntrack_info ctinfo)
	41	{
	42	struct tftphdr _tftph, *tfh;
	43	struct nf_conntrack_expect *exp;
	44	struct nf_conntrack_tuple *tuple;
	45	unsigned int ret = NF_ACCEPT;
	46	int family = ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.l3num;
	47	typeof(nf_nat_tftp_hook) nf_nat_tftp;
	48
3db05fea	49	tfh = skb_header_pointer(skb, protoff + sizeof(struct udphdr),
a536df35 PM	50	sizeof(_tftph), &_tftph);
	51	if (tfh == NULL)
	52	return NF_ACCEPT;
	53
	54	switch (ntohs(tfh->opcode)) {
	55	case TFTP_OPCODE_READ:
	56	case TFTP_OPCODE_WRITE:
	57	/* RRQ and WRQ works the same way */
a536df35 PM	58	NF_CT_DUMP_TUPLE(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
	59	NF_CT_DUMP_TUPLE(&ct->tuplehash[IP_CT_DIR_REPLY].tuple);
	60
6823645d	61	exp = nf_ct_expect_alloc(ct);
a536df35 PM	62	if (exp == NULL)
	63	return NF_DROP;
	64	tuple = &ct->tuplehash[IP_CT_DIR_REPLY].tuple;
6823645d PM	65	nf_ct_expect_init(exp, family, &tuple->src.u3, &tuple->dst.u3,
6823645d PM	66	IPPROTO_UDP, NULL, &tuple->dst.u.udp.port);
a536df35	67
0d53778e	68	pr_debug("expect: ");
a536df35	69	NF_CT_DUMP_TUPLE(&exp->tuple);
a536df35 PM	70
	71	nf_nat_tftp = rcu_dereference(nf_nat_tftp_hook);
	72	if (nf_nat_tftp && ct->status & IPS_NAT_MASK)
3db05fea	73	ret = nf_nat_tftp(skb, ctinfo, exp);
6823645d	74	else if (nf_ct_expect_related(exp) != 0)
a536df35	75	ret = NF_DROP;
6823645d	76	nf_ct_expect_put(exp);
a536df35 PM	77	break;
	78	case TFTP_OPCODE_DATA:
	79	case TFTP_OPCODE_ACK:
0d53778e	80	pr_debug("Data/ACK opcode\n");
a536df35 PM	81	break;
a536df35 PM	82	case TFTP_OPCODE_ERROR:
0d53778e	83	pr_debug("Error opcode\n");
a536df35 PM	84	break;
a536df35 PM	85	default:
0d53778e	86	pr_debug("Unknown opcode\n");
a536df35 PM	87	}
	88	return ret;
	89	}
	90
	91	static struct nf_conntrack_helper tftp[MAX_PORTS][2] __read_mostly;
	92	static char tftp_names[MAX_PORTS][2][sizeof("tftp-65535")] __read_mostly;
	93
	94	static void nf_conntrack_tftp_fini(void)
	95	{
	96	int i, j;
	97
	98	for (i = 0; i < ports_c; i++) {
	99	for (j = 0; j < 2; j++)
	100	nf_conntrack_helper_unregister(&tftp[i][j]);
	101	}
	102	}
	103
	104	static int __init nf_conntrack_tftp_init(void)
	105	{
	106	int i, j, ret;
	107	char *tmpname;
	108
	109	if (ports_c == 0)
	110	ports[ports_c++] = TFTP_PORT;
	111
	112	for (i = 0; i < ports_c; i++) {
	113	memset(&tftp[i], 0, sizeof(tftp[i]));
	114
	115	tftp[i][0].tuple.src.l3num = AF_INET;
	116	tftp[i][1].tuple.src.l3num = AF_INET6;
	117	for (j = 0; j < 2; j++) {
	118	tftp[i][j].tuple.dst.protonum = IPPROTO_UDP;
	119	tftp[i][j].tuple.src.u.udp.port = htons(ports[i]);
a536df35 PM	120	tftp[i][j].max_expected = 1;
	121	tftp[i][j].timeout = 5 * 60; /* 5 minutes */
	122	tftp[i][j].me = THIS_MODULE;
	123	tftp[i][j].help = tftp_help;
	124
	125	tmpname = &tftp_names[i][j][0];
	126	if (ports[i] == TFTP_PORT)
	127	sprintf(tmpname, "tftp");
	128	else
	129	sprintf(tmpname, "tftp-%u", i);
	130	tftp[i][j].name = tmpname;
	131
	132	ret = nf_conntrack_helper_register(&tftp[i][j]);
	133	if (ret) {
	134	printk("nf_ct_tftp: failed to register helper "
	135	"for pf: %u port: %u\n",
	136	tftp[i][j].tuple.src.l3num, ports[i]);
	137	nf_conntrack_tftp_fini();
	138	return ret;
	139	}
	140	}
	141	}
	142	return 0;
	143	}
	144
	145	module_init(nf_conntrack_tftp_init);
	146	module_exit(nf_conntrack_tftp_fini);