mirror of
https://github.com/team-infusion-developers/android_kernel_samsung_msm8976.git
synced 2024-10-19 18:09:05 +00:00
e104411b82
Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
281 lines
7.2 KiB
C
281 lines
7.2 KiB
C
/*
|
|
* IP6 tables REJECT target module
|
|
* Linux INET6 implementation
|
|
*
|
|
* Copyright (C)2003 USAGI/WIDE Project
|
|
*
|
|
* Authors:
|
|
* Yasuyuki Kozakai <yasuyuki.kozakai@toshiba.co.jp>
|
|
*
|
|
* Based on net/ipv4/netfilter/ipt_REJECT.c
|
|
*
|
|
* This program is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU General Public License
|
|
* as published by the Free Software Foundation; either version
|
|
* 2 of the License, or (at your option) any later version.
|
|
*/
|
|
|
|
#include <linux/config.h>
|
|
#include <linux/module.h>
|
|
#include <linux/skbuff.h>
|
|
#include <linux/icmpv6.h>
|
|
#include <linux/netdevice.h>
|
|
#include <net/ipv6.h>
|
|
#include <net/tcp.h>
|
|
#include <net/icmp.h>
|
|
#include <net/ip6_checksum.h>
|
|
#include <net/ip6_fib.h>
|
|
#include <net/ip6_route.h>
|
|
#include <net/flow.h>
|
|
#include <linux/netfilter_ipv6/ip6_tables.h>
|
|
#include <linux/netfilter_ipv6/ip6t_REJECT.h>
|
|
|
|
MODULE_AUTHOR("Yasuyuki KOZAKAI <yasuyuki.kozakai@toshiba.co.jp>");
|
|
MODULE_DESCRIPTION("IP6 tables REJECT target module");
|
|
MODULE_LICENSE("GPL");
|
|
|
|
#if 0
|
|
#define DEBUGP printk
|
|
#else
|
|
#define DEBUGP(format, args...)
|
|
#endif
|
|
|
|
/* Send RST reply */
|
|
static void send_reset(struct sk_buff *oldskb)
|
|
{
|
|
struct sk_buff *nskb;
|
|
struct tcphdr otcph, *tcph;
|
|
unsigned int otcplen, hh_len;
|
|
int tcphoff, needs_ack;
|
|
struct ipv6hdr *oip6h = oldskb->nh.ipv6h, *ip6h;
|
|
struct dst_entry *dst = NULL;
|
|
u8 proto;
|
|
struct flowi fl;
|
|
|
|
if ((!(ipv6_addr_type(&oip6h->saddr) & IPV6_ADDR_UNICAST)) ||
|
|
(!(ipv6_addr_type(&oip6h->daddr) & IPV6_ADDR_UNICAST))) {
|
|
DEBUGP("ip6t_REJECT: addr is not unicast.\n");
|
|
return;
|
|
}
|
|
|
|
proto = oip6h->nexthdr;
|
|
tcphoff = ipv6_skip_exthdr(oldskb, ((u8*)(oip6h+1) - oldskb->data), &proto);
|
|
|
|
if ((tcphoff < 0) || (tcphoff > oldskb->len)) {
|
|
DEBUGP("ip6t_REJECT: Can't get TCP header.\n");
|
|
return;
|
|
}
|
|
|
|
otcplen = oldskb->len - tcphoff;
|
|
|
|
/* IP header checks: fragment, too short. */
|
|
if ((proto != IPPROTO_TCP) || (otcplen < sizeof(struct tcphdr))) {
|
|
DEBUGP("ip6t_REJECT: proto(%d) != IPPROTO_TCP, or too short. otcplen = %d\n",
|
|
proto, otcplen);
|
|
return;
|
|
}
|
|
|
|
if (skb_copy_bits(oldskb, tcphoff, &otcph, sizeof(struct tcphdr)))
|
|
BUG();
|
|
|
|
/* No RST for RST. */
|
|
if (otcph.rst) {
|
|
DEBUGP("ip6t_REJECT: RST is set\n");
|
|
return;
|
|
}
|
|
|
|
/* Check checksum. */
|
|
if (csum_ipv6_magic(&oip6h->saddr, &oip6h->daddr, otcplen, IPPROTO_TCP,
|
|
skb_checksum(oldskb, tcphoff, otcplen, 0))) {
|
|
DEBUGP("ip6t_REJECT: TCP checksum is invalid\n");
|
|
return;
|
|
}
|
|
|
|
memset(&fl, 0, sizeof(fl));
|
|
fl.proto = IPPROTO_TCP;
|
|
ipv6_addr_copy(&fl.fl6_src, &oip6h->daddr);
|
|
ipv6_addr_copy(&fl.fl6_dst, &oip6h->saddr);
|
|
fl.fl_ip_sport = otcph.dest;
|
|
fl.fl_ip_dport = otcph.source;
|
|
dst = ip6_route_output(NULL, &fl);
|
|
if (dst == NULL)
|
|
return;
|
|
if (dst->error || xfrm_lookup(&dst, &fl, NULL, 0))
|
|
return;
|
|
|
|
hh_len = (dst->dev->hard_header_len + 15)&~15;
|
|
nskb = alloc_skb(hh_len + 15 + dst->header_len + sizeof(struct ipv6hdr)
|
|
+ sizeof(struct tcphdr) + dst->trailer_len,
|
|
GFP_ATOMIC);
|
|
|
|
if (!nskb) {
|
|
if (net_ratelimit())
|
|
printk("ip6t_REJECT: Can't alloc skb\n");
|
|
dst_release(dst);
|
|
return;
|
|
}
|
|
|
|
nskb->dst = dst;
|
|
|
|
skb_reserve(nskb, hh_len + dst->header_len);
|
|
|
|
ip6h = nskb->nh.ipv6h = (struct ipv6hdr *)
|
|
skb_put(nskb, sizeof(struct ipv6hdr));
|
|
ip6h->version = 6;
|
|
ip6h->hop_limit = dst_metric(dst, RTAX_HOPLIMIT);
|
|
ip6h->nexthdr = IPPROTO_TCP;
|
|
ip6h->payload_len = htons(sizeof(struct tcphdr));
|
|
ipv6_addr_copy(&ip6h->saddr, &oip6h->daddr);
|
|
ipv6_addr_copy(&ip6h->daddr, &oip6h->saddr);
|
|
|
|
tcph = (struct tcphdr *)skb_put(nskb, sizeof(struct tcphdr));
|
|
/* Truncate to length (no data) */
|
|
tcph->doff = sizeof(struct tcphdr)/4;
|
|
tcph->source = otcph.dest;
|
|
tcph->dest = otcph.source;
|
|
|
|
if (otcph.ack) {
|
|
needs_ack = 0;
|
|
tcph->seq = otcph.ack_seq;
|
|
tcph->ack_seq = 0;
|
|
} else {
|
|
needs_ack = 1;
|
|
tcph->ack_seq = htonl(ntohl(otcph.seq) + otcph.syn + otcph.fin
|
|
+ otcplen - (otcph.doff<<2));
|
|
tcph->seq = 0;
|
|
}
|
|
|
|
/* Reset flags */
|
|
((u_int8_t *)tcph)[13] = 0;
|
|
tcph->rst = 1;
|
|
tcph->ack = needs_ack;
|
|
tcph->window = 0;
|
|
tcph->urg_ptr = 0;
|
|
tcph->check = 0;
|
|
|
|
/* Adjust TCP checksum */
|
|
tcph->check = csum_ipv6_magic(&nskb->nh.ipv6h->saddr,
|
|
&nskb->nh.ipv6h->daddr,
|
|
sizeof(struct tcphdr), IPPROTO_TCP,
|
|
csum_partial((char *)tcph,
|
|
sizeof(struct tcphdr), 0));
|
|
|
|
NF_HOOK(PF_INET6, NF_IP6_LOCAL_OUT, nskb, NULL, nskb->dst->dev,
|
|
dst_output);
|
|
}
|
|
|
|
static inline void
|
|
send_unreach(struct sk_buff *skb_in, unsigned char code, unsigned int hooknum)
|
|
{
|
|
if (hooknum == NF_IP6_LOCAL_OUT && skb_in->dev == NULL)
|
|
skb_in->dev = &loopback_dev;
|
|
|
|
icmpv6_send(skb_in, ICMPV6_DEST_UNREACH, code, 0, NULL);
|
|
}
|
|
|
|
static unsigned int reject6_target(struct sk_buff **pskb,
|
|
const struct net_device *in,
|
|
const struct net_device *out,
|
|
unsigned int hooknum,
|
|
const void *targinfo,
|
|
void *userinfo)
|
|
{
|
|
const struct ip6t_reject_info *reject = targinfo;
|
|
|
|
DEBUGP(KERN_DEBUG "%s: medium point\n", __FUNCTION__);
|
|
/* WARNING: This code causes reentry within ip6tables.
|
|
This means that the ip6tables jump stack is now crap. We
|
|
must return an absolute verdict. --RR */
|
|
switch (reject->with) {
|
|
case IP6T_ICMP6_NO_ROUTE:
|
|
send_unreach(*pskb, ICMPV6_NOROUTE, hooknum);
|
|
break;
|
|
case IP6T_ICMP6_ADM_PROHIBITED:
|
|
send_unreach(*pskb, ICMPV6_ADM_PROHIBITED, hooknum);
|
|
break;
|
|
case IP6T_ICMP6_NOT_NEIGHBOUR:
|
|
send_unreach(*pskb, ICMPV6_NOT_NEIGHBOUR, hooknum);
|
|
break;
|
|
case IP6T_ICMP6_ADDR_UNREACH:
|
|
send_unreach(*pskb, ICMPV6_ADDR_UNREACH, hooknum);
|
|
break;
|
|
case IP6T_ICMP6_PORT_UNREACH:
|
|
send_unreach(*pskb, ICMPV6_PORT_UNREACH, hooknum);
|
|
break;
|
|
case IP6T_ICMP6_ECHOREPLY:
|
|
/* Do nothing */
|
|
break;
|
|
case IP6T_TCP_RESET:
|
|
send_reset(*pskb);
|
|
break;
|
|
default:
|
|
if (net_ratelimit())
|
|
printk(KERN_WARNING "ip6t_REJECT: case %u not handled yet\n", reject->with);
|
|
break;
|
|
}
|
|
|
|
return NF_DROP;
|
|
}
|
|
|
|
static int check(const char *tablename,
|
|
const struct ip6t_entry *e,
|
|
void *targinfo,
|
|
unsigned int targinfosize,
|
|
unsigned int hook_mask)
|
|
{
|
|
const struct ip6t_reject_info *rejinfo = targinfo;
|
|
|
|
if (targinfosize != IP6T_ALIGN(sizeof(struct ip6t_reject_info))) {
|
|
DEBUGP("ip6t_REJECT: targinfosize %u != 0\n", targinfosize);
|
|
return 0;
|
|
}
|
|
|
|
/* Only allow these for packet filtering. */
|
|
if (strcmp(tablename, "filter") != 0) {
|
|
DEBUGP("ip6t_REJECT: bad table `%s'.\n", tablename);
|
|
return 0;
|
|
}
|
|
|
|
if ((hook_mask & ~((1 << NF_IP6_LOCAL_IN)
|
|
| (1 << NF_IP6_FORWARD)
|
|
| (1 << NF_IP6_LOCAL_OUT))) != 0) {
|
|
DEBUGP("ip6t_REJECT: bad hook mask %X\n", hook_mask);
|
|
return 0;
|
|
}
|
|
|
|
if (rejinfo->with == IP6T_ICMP6_ECHOREPLY) {
|
|
printk("ip6t_REJECT: ECHOREPLY is not supported.\n");
|
|
return 0;
|
|
} else if (rejinfo->with == IP6T_TCP_RESET) {
|
|
/* Must specify that it's a TCP packet */
|
|
if (e->ipv6.proto != IPPROTO_TCP
|
|
|| (e->ipv6.invflags & IP6T_INV_PROTO)) {
|
|
DEBUGP("ip6t_REJECT: TCP_RESET illegal for non-tcp\n");
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
return 1;
|
|
}
|
|
|
|
static struct ip6t_target ip6t_reject_reg = {
|
|
.name = "REJECT",
|
|
.target = reject6_target,
|
|
.checkentry = check,
|
|
.me = THIS_MODULE
|
|
};
|
|
|
|
static int __init init(void)
|
|
{
|
|
if (ip6t_register_target(&ip6t_reject_reg))
|
|
return -EINVAL;
|
|
return 0;
|
|
}
|
|
|
|
static void __exit fini(void)
|
|
{
|
|
ip6t_unregister_target(&ip6t_reject_reg);
|
|
}
|
|
|
|
module_init(init);
|
|
module_exit(fini);
|