r4sas/ts3init_linux_netfilter_module
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moved ts3init-header specific definitions into a seperate header file.

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This commit is contained in:
Maximilian Münchow 2016-10-11 09:23:22 +02:00
parent b31273e12f
commit 8348d1e327
2 changed files with 59 additions and 40 deletions
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41
src/ts3init_header.h Normal file
View File

@ -0,0 +1,41 @@
#ifndef _TS3INIT_HEADER_H
#define _TS3INIT_HEADER_H
struct ts3_init_header_tag
{
union
{
char tag8[8];
__aligned_u64 tag64;
};
};
struct ts3_init_header
{
struct ts3_init_header_tag tag;
__be16 packet_id;
__be16 client_id;
__u8 flags;
__u8 client_version[4];
__u8 command;
__u8 payload[20];
};
struct ts3_init_checked_header_data
{
struct udphdr *udp, udp_buf;
struct ts3_init_header* ts3_header, ts3_header_buf;
};
enum
{
COMMAND_GET_COOKIE = 0,
COMMAND_SET_COOKIE,
COMMAND_GET_PUZZLE,
COMMAND_SET_PUZZLE,
COMMAND_SOLVE_PUZZLE,
COMMAND_RESET_PUZZLE,
COMMAND_MAX
};
#endif /* _TS3INIT_HEADER_H */

58
src/ts3init_match.c
View File

@ -21,6 +21,7 @@
#include <linux/percpu.h>
#include "ts3init_match.h"
#include "ts3init_cookie.h"
#include "ts3init_header.h"
struct ts3init_cache_t
{
@ -29,54 +30,26 @@ struct ts3init_cache_t
struct xt_ts3init_cookie_cache cookie_cache;
};
struct ts3_init_header_tag
{
union
{
char tag8[8];
__aligned_u64 tag64;
};
};
struct ts3_init_header
{
struct ts3_init_header_tag tag;
__be16 packet_id;
__be16 client_id;
__u8 flags;
__u8 client_version[4];
__u8 command;
__u8 payload[20];
};
struct ts3_init_checked_header_data
{
struct udphdr *udp, udp_buf;
struct ts3_init_header* ts3_header, ts3_header_buf;
};
enum
{
GET_COOKIE_PAYLOAD_SIZE = 34,
GET_PUZZLE_PAYLOAD_SIZE = 38
};
static const struct ts3_init_header_tag ts3init_header_tag_signature =
{ .tag8 = {'T', 'S', '3', 'I', 'N', 'I', 'T', '1'} };
static const int header_size = 18;
static int payload_sizes[] = { 16, 20, 20, 244, -1, 1 };
DEFINE_PER_CPU(struct ts3init_cache_t, ts3init_cache);
static inline bool check_header(const struct sk_buff *skb, struct xt_action_param *par,
int payload_size, struct ts3_init_checked_header_data* header_data)
bool check_header(const struct sk_buff *skb, const struct xt_action_param *par,
struct ts3_init_checked_header_data* header_data)
{
unsigned int data_len;
struct udphdr *udp;
struct ts3_init_header* ts3_header;
int expected_payload_size;
udp = skb_header_pointer(skb, par->thoff, sizeof(*udp), &header_data->udp_buf);
data_len = be16_to_cpu(udp->len) - sizeof(*udp);
if (data_len != payload_size) return false;
if (data_len < header_size) return false;
ts3_header = (struct ts3_init_header*) skb_header_pointer(skb,
par->thoff + sizeof(*udp), data_len,
@ -88,9 +61,14 @@ static inline bool check_header(const struct sk_buff *skb, struct xt_action_para
if (ts3_header->packet_id != cpu_to_be16(101)) return false;
if (ts3_header->client_id != 0) return false;
if (ts3_header->flags != 0x88) return false;
if (ts3_header->command >= COMMAND_MAX) return false;
/* TODO: check min_client_version if needed */
/* TODO: add payload size check for COMMAND_SOLVE_PUZZLE */
expected_payload_size = payload_sizes[ts3_header->command];
if (data_len != header_size + expected_payload_size) return false;
header_data->udp = udp;
header_data->ts3_header = ts3_header;
return true;
@ -116,10 +94,10 @@ ts3init_get_cookie_mt(const struct sk_buff *skb, struct xt_action_param *par)
const struct xt_ts3init_get_cookie_mtinfo *info = par->matchinfo;
struct ts3_init_checked_header_data header_data;
if (!check_header(skb, par, GET_COOKIE_PAYLOAD_SIZE, &header_data))
if (!check_header(skb, par, &header_data))
return false;
if (header_data.ts3_header->command != 0) return false;
if (header_data.ts3_header->command != COMMAND_GET_COOKIE) return false;
if (info->specific_options & CHK_GET_COOKIE_CHECK_TIMESTAMP)
{
@ -180,10 +158,10 @@ ts3init_get_puzzle_mt(const struct sk_buff *skb, struct xt_action_param *par)
const struct xt_ts3init_get_puzzle_mtinfo *info = par->matchinfo;
struct ts3_init_checked_header_data header_data;
if (!check_header(skb, par, GET_PUZZLE_PAYLOAD_SIZE, &header_data))
if (!check_header(skb, par, &header_data))
return false;
if (header_data.ts3_header->command != 2) return false;
if (header_data.ts3_header->command != COMMAND_GET_PUZZLE) return false;
if (info->specific_options & CHK_GET_PUZZLE_CHECK_COOKIE)
{