| 1 |
1275 |
phoenix |
#include <linux/types.h>
|
| 2 |
|
|
#include <linux/sched.h>
|
| 3 |
|
|
#include <linux/timer.h>
|
| 4 |
|
|
#include <linux/netfilter.h>
|
| 5 |
|
|
#include <linux/in.h>
|
| 6 |
|
|
#include <linux/icmp.h>
|
| 7 |
|
|
#include <linux/netfilter_ipv4/ip_conntrack_protocol.h>
|
| 8 |
|
|
|
| 9 |
|
|
unsigned long ip_ct_icmp_timeout = 30*HZ;
|
| 10 |
|
|
|
| 11 |
|
|
#if 0
|
| 12 |
|
|
#define DEBUGP printk
|
| 13 |
|
|
#else
|
| 14 |
|
|
#define DEBUGP(format, args...)
|
| 15 |
|
|
#endif
|
| 16 |
|
|
|
| 17 |
|
|
static int icmp_pkt_to_tuple(const void *datah, size_t datalen,
|
| 18 |
|
|
struct ip_conntrack_tuple *tuple)
|
| 19 |
|
|
{
|
| 20 |
|
|
const struct icmphdr *hdr = datah;
|
| 21 |
|
|
|
| 22 |
|
|
tuple->dst.u.icmp.type = hdr->type;
|
| 23 |
|
|
tuple->src.u.icmp.id = hdr->un.echo.id;
|
| 24 |
|
|
tuple->dst.u.icmp.code = hdr->code;
|
| 25 |
|
|
|
| 26 |
|
|
return 1;
|
| 27 |
|
|
}
|
| 28 |
|
|
|
| 29 |
|
|
static int icmp_invert_tuple(struct ip_conntrack_tuple *tuple,
|
| 30 |
|
|
const struct ip_conntrack_tuple *orig)
|
| 31 |
|
|
{
|
| 32 |
|
|
/* Add 1; spaces filled with 0. */
|
| 33 |
|
|
static u_int8_t invmap[]
|
| 34 |
|
|
= { [ICMP_ECHO] = ICMP_ECHOREPLY + 1,
|
| 35 |
|
|
[ICMP_ECHOREPLY] = ICMP_ECHO + 1,
|
| 36 |
|
|
[ICMP_TIMESTAMP] = ICMP_TIMESTAMPREPLY + 1,
|
| 37 |
|
|
[ICMP_TIMESTAMPREPLY] = ICMP_TIMESTAMP + 1,
|
| 38 |
|
|
[ICMP_INFO_REQUEST] = ICMP_INFO_REPLY + 1,
|
| 39 |
|
|
[ICMP_INFO_REPLY] = ICMP_INFO_REQUEST + 1,
|
| 40 |
|
|
[ICMP_ADDRESS] = ICMP_ADDRESSREPLY + 1,
|
| 41 |
|
|
[ICMP_ADDRESSREPLY] = ICMP_ADDRESS + 1};
|
| 42 |
|
|
|
| 43 |
|
|
if (orig->dst.u.icmp.type >= sizeof(invmap)
|
| 44 |
|
|
|| !invmap[orig->dst.u.icmp.type])
|
| 45 |
|
|
return 0;
|
| 46 |
|
|
|
| 47 |
|
|
tuple->src.u.icmp.id = orig->src.u.icmp.id;
|
| 48 |
|
|
tuple->dst.u.icmp.type = invmap[orig->dst.u.icmp.type] - 1;
|
| 49 |
|
|
tuple->dst.u.icmp.code = orig->dst.u.icmp.code;
|
| 50 |
|
|
return 1;
|
| 51 |
|
|
}
|
| 52 |
|
|
|
| 53 |
|
|
/* Print out the per-protocol part of the tuple. */
|
| 54 |
|
|
static unsigned int icmp_print_tuple(char *buffer,
|
| 55 |
|
|
const struct ip_conntrack_tuple *tuple)
|
| 56 |
|
|
{
|
| 57 |
|
|
return sprintf(buffer, "type=%u code=%u id=%u ",
|
| 58 |
|
|
tuple->dst.u.icmp.type,
|
| 59 |
|
|
tuple->dst.u.icmp.code,
|
| 60 |
|
|
ntohs(tuple->src.u.icmp.id));
|
| 61 |
|
|
}
|
| 62 |
|
|
|
| 63 |
|
|
/* Print out the private part of the conntrack. */
|
| 64 |
|
|
static unsigned int icmp_print_conntrack(char *buffer,
|
| 65 |
|
|
const struct ip_conntrack *conntrack)
|
| 66 |
|
|
{
|
| 67 |
|
|
return 0;
|
| 68 |
|
|
}
|
| 69 |
|
|
|
| 70 |
|
|
/* Returns verdict for packet, or -1 for invalid. */
|
| 71 |
|
|
static int icmp_packet(struct ip_conntrack *ct,
|
| 72 |
|
|
struct iphdr *iph, size_t len,
|
| 73 |
|
|
enum ip_conntrack_info ctinfo)
|
| 74 |
|
|
{
|
| 75 |
|
|
/* Try to delete connection immediately after all replies:
|
| 76 |
|
|
won't actually vanish as we still have skb, and del_timer
|
| 77 |
|
|
means this will only run once even if count hits zero twice
|
| 78 |
|
|
(theoretically possible with SMP) */
|
| 79 |
|
|
if (CTINFO2DIR(ctinfo) == IP_CT_DIR_REPLY) {
|
| 80 |
|
|
if (atomic_dec_and_test(&ct->proto.icmp.count)
|
| 81 |
|
|
&& del_timer(&ct->timeout))
|
| 82 |
|
|
ct->timeout.function((unsigned long)ct);
|
| 83 |
|
|
} else {
|
| 84 |
|
|
atomic_inc(&ct->proto.icmp.count);
|
| 85 |
|
|
ip_ct_refresh(ct, ip_ct_icmp_timeout);
|
| 86 |
|
|
}
|
| 87 |
|
|
|
| 88 |
|
|
return NF_ACCEPT;
|
| 89 |
|
|
}
|
| 90 |
|
|
|
| 91 |
|
|
/* Called when a new connection for this protocol found. */
|
| 92 |
|
|
static int icmp_new(struct ip_conntrack *conntrack,
|
| 93 |
|
|
struct iphdr *iph, size_t len)
|
| 94 |
|
|
{
|
| 95 |
|
|
static u_int8_t valid_new[]
|
| 96 |
|
|
= { [ICMP_ECHO] = 1,
|
| 97 |
|
|
[ICMP_TIMESTAMP] = 1,
|
| 98 |
|
|
[ICMP_INFO_REQUEST] = 1,
|
| 99 |
|
|
[ICMP_ADDRESS] = 1 };
|
| 100 |
|
|
|
| 101 |
|
|
if (conntrack->tuplehash[0].tuple.dst.u.icmp.type >= sizeof(valid_new)
|
| 102 |
|
|
|| !valid_new[conntrack->tuplehash[0].tuple.dst.u.icmp.type]) {
|
| 103 |
|
|
/* Can't create a new ICMP `conn' with this. */
|
| 104 |
|
|
DEBUGP("icmp: can't create new conn with type %u\n",
|
| 105 |
|
|
conntrack->tuplehash[0].tuple.dst.u.icmp.type);
|
| 106 |
|
|
DUMP_TUPLE(&conntrack->tuplehash[0].tuple);
|
| 107 |
|
|
return 0;
|
| 108 |
|
|
}
|
| 109 |
|
|
atomic_set(&conntrack->proto.icmp.count, 0);
|
| 110 |
|
|
return 1;
|
| 111 |
|
|
}
|
| 112 |
|
|
|
| 113 |
|
|
struct ip_conntrack_protocol ip_conntrack_protocol_icmp
|
| 114 |
|
|
= { { NULL, NULL }, IPPROTO_ICMP, "icmp",
|
| 115 |
|
|
icmp_pkt_to_tuple, icmp_invert_tuple, icmp_print_tuple,
|
| 116 |
|
|
icmp_print_conntrack, icmp_packet, icmp_new, NULL, NULL, NULL };
|
