r4sas/ts3init_linux_netfilter_module
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added min_client_version check

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This commit is contained in:
Niels Werensteijn 2016-10-11 15:09:26 +02:00
parent 2bf9af83b9
commit 4a11da005b
1 changed files with 17 additions and 5 deletions
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22
src/ts3init_match.c
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@ -39,7 +39,7 @@ static int ts3init_payload_sizes[] = { 16, 20, 20, 244, -1, 1 };
DEFINE_PER_CPU(struct ts3init_cache_t, ts3init_cache);
static bool check_header(const struct sk_buff *skb, const struct xt_action_param *par,
struct ts3_init_checked_header_data* header_data)
struct ts3_init_checked_header_data* header_data, __u32 min_client_version)
{
unsigned int data_len;
struct udphdr *udp;
@ -63,9 +63,21 @@ static bool check_header(const struct sk_buff *skb, const struct xt_action_param
if (ts3_header->flags != 0x88) return false;
if (ts3_header->command >= COMMAND_MAX) return false;
/* TODO: check min_client_version if needed */
/* check min_client_version if needed */
if (min_client_version)
{
/* the client version is unaligned in the packet.
* load it byte for byte. big endian*/
__u8* v = ts3_header->client_version;
__u32 packet_min_client_version =
((__u32)v[0]) << 24 | ((__u32)v[1]) << 16 |
((__u32)v[1]) << 8 | ((__u32)v[3]);
/* TODO: add payload size check for COMMAND_SOLVE_PUZZLE */
if (packet_min_client_version < min_client_version)
return false;
}
/* payload size check*/
expected_payload_size = ts3init_payload_sizes[ts3_header->command];
if (data_len != header_size + expected_payload_size) return false;
@ -94,7 +106,7 @@ 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, &header_data))
if (!check_header(skb, par, &header_data, info->min_client_version))
return false;
if (header_data.ts3_header->command != COMMAND_GET_COOKIE) return false;
@ -158,7 +170,7 @@ 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, &header_data))
if (!check_header(skb, par, &header_data, info->min_client_version))
return false;
if (header_data.ts3_header->command != COMMAND_GET_PUZZLE) return false;