Some of the matchers have hand-rolled substring search implementations.
Replace them with the kernel's textsearch API.
Signed-off-by: Jeremy Sowden <jeremy@xxxxxxxxxx>
---
extensions/xt_ipp2p.c | 312 +++++++++++++++++++++++++++++++-----------
extensions/xt_ipp2p.h | 10 ++
2 files changed, 245 insertions(+), 77 deletions(-)
diff --git a/extensions/xt_ipp2p.c b/extensions/xt_ipp2p.c
index ae9a3dd2a920..1378701605c3 100644
--- a/extensions/xt_ipp2p.c
+++ b/extensions/xt_ipp2p.c
@@ -1,4 +1,6 @@
+#include <linux/gfp.h>
#include <linux/module.h>
+#include <linux/textsearch.h>
#include <linux/version.h>
#include <linux/netfilter_ipv4/ip_tables.h>
#include <net/tcp.h>
@@ -55,7 +57,8 @@ print_result(const struct ipp2p_result_printer *rp, bool result,
/* Search for UDP eDonkey/eMule/Kad commands */
static unsigned int
-udp_search_edk(const unsigned char *t, const unsigned int packet_len)
+udp_search_edk(const unsigned char *t, const unsigned int packet_len,
+ const struct ipt_p2p_info *info)
{
if (packet_len < 4)
return 0;
@@ -173,7 +176,8 @@ udp_search_edk(const unsigned char *t, const unsigned int packet_len)
/* Search for UDP Gnutella commands */
static unsigned int
-udp_search_gnu(const unsigned char *t, const unsigned int packet_len)
+udp_search_gnu(const unsigned char *t, const unsigned int packet_len,
+ const struct ipt_p2p_info *info)
{
if (packet_len >= 3 && memcmp(t, "GND", 3) == 0)
return IPP2P_GNU * 100 + 51;
@@ -184,7 +188,8 @@ udp_search_gnu(const unsigned char *t, const unsigned int packet_len)
/* Search for UDP KaZaA commands */
static unsigned int
-udp_search_kazaa(const unsigned char *t, const unsigned int packet_len)
+udp_search_kazaa(const unsigned char *t, const unsigned int packet_len,
+ const struct ipt_p2p_info *info)
{
if (packet_len < 6)
return 0;
@@ -194,8 +199,9 @@ udp_search_kazaa(const unsigned char *t, const unsigned int packet_len)
}
/* Search for UDP DirectConnect commands */
-static unsigned int udp_search_directconnect(const unsigned char *t,
- const unsigned int packet_len)
+static unsigned int
+udp_search_directconnect(const unsigned char *t, const unsigned int packet_len,
+ const struct ipt_p2p_info *info)
{
if (packet_len < 5)
return 0;
@@ -212,7 +218,8 @@ static unsigned int udp_search_directconnect(const unsigned char *t,
/* Search for UDP BitTorrent commands */
static unsigned int
-udp_search_bit(const unsigned char *haystack, const unsigned int packet_len)
+udp_search_bit(const unsigned char *haystack, const unsigned int packet_len,
+ const struct ipt_p2p_info *info)
{
switch (packet_len) {
case 16:
@@ -298,7 +305,8 @@ udp_search_bit(const unsigned char *haystack, const unsigned int packet_len)
/* Search for Ares commands */
static unsigned int
-search_ares(const unsigned char *payload, const unsigned int plen)
+search_ares(const unsigned char *payload, const unsigned int plen,
+ const struct ipt_p2p_info *info)
{
if (plen < 3)
return 0;
@@ -350,7 +358,8 @@ search_ares(const unsigned char *payload, const unsigned int plen)
/* Search for SoulSeek commands */
static unsigned int
-search_soul(const unsigned char *payload, const unsigned int plen)
+search_soul(const unsigned char *payload, const unsigned int plen,
+ const struct ipt_p2p_info *info)
{
if (plen < 8)
return 0;
@@ -474,8 +483,11 @@ search_soul(const unsigned char *payload, const unsigned int plen)
/* Search for WinMX commands */
static unsigned int
-search_winmx(const unsigned char *payload, const unsigned int plen)
+search_winmx(const unsigned char *payload, const unsigned int plen,
+ const struct ipt_p2p_info *info)
{
+ uint16_t start;
+
if (plen == 4 && memcmp(payload, "SEND", 4) == 0)
return IPP2P_WINMX * 100 + 1;
if (plen == 3 && memcmp(payload, "GET", 3) == 0)
@@ -487,20 +499,33 @@ search_winmx(const unsigned char *payload, const unsigned int plen)
if (plen < 10)
return 0;
- if (memcmp(payload, "SEND", 4) == 0 || memcmp(payload, "GET", 3) == 0) {
- uint16_t c = 4;
- const uint16_t end = plen - 2;
+ if (memcmp(payload, "SEND", 4) == 0)
+ start = 4;
+ else if (memcmp(payload, "GET", 3) == 0)
+ start = 3;
+ else
+ start = 0;
+
+ if (start) {
uint8_t count = 0;
- while (c < end) {
- if (payload[c] == 0x20 && payload[c+1] == 0x22) {
- c++;
- count++;
- if (count >= 2)
- return IPP2P_WINMX * 100 + 3;
- }
- c++;
- }
+ do {
+ struct ts_state state;
+ unsigned int pos;
+
+ pos = textsearch_find_continuous(info->ts_conf_winmx,
+ &state,
+ &payload[start],
+ plen - start);
+ if (pos == UINT_MAX)
+ break;
+
+ count++;
+ if (count >= 2)
+ return IPP2P_WINMX * 100 + 3;
+
+ start = pos + 2;
+ } while (start < plen);
}
if (plen == 149 && payload[0] == '8') {
@@ -528,7 +553,8 @@ search_winmx(const unsigned char *payload, const unsigned int plen)
/* Search for appleJuice commands */
static unsigned int
-search_apple(const unsigned char *payload, const unsigned int plen)
+search_apple(const unsigned char *payload, const unsigned int plen,
+ const struct ipt_p2p_info *info)
{
if (plen < 8)
return 0;
@@ -539,8 +565,12 @@ search_apple(const unsigned char *payload, const unsigned int plen)
/* Search for BitTorrent commands */
static unsigned int
-search_bittorrent(const unsigned char *payload, const unsigned int plen)
+search_bittorrent(const unsigned char *payload, const unsigned int plen,
+ const struct ipt_p2p_info *info)
{
+ struct ts_state state;
+ unsigned int pos;
+
/*
* bitcomet encrypts the first packet, so we have to detect another one
* later in the flow.
@@ -567,11 +597,20 @@ search_bittorrent(const unsigned char *payload, const unsigned int plen)
*/
if (memcmp(payload, "GET /", 5) != 0)
return 0;
- if (HX_memmem(payload, plen, "info_hash=", 10) != NULL)
+
+ pos = textsearch_find_continuous(info->ts_conf_bt_info_hash,
+ &state, &payload[5], plen - 5);
+ if (pos != UINT_MAX)
return IPP2P_BIT * 100 + 1;
- if (HX_memmem(payload, plen, "peer_id=", 8) != NULL)
+
+ pos = textsearch_find_continuous(info->ts_conf_bt_peer_id,
+ &state, &payload[5], plen - 5);
+ if (pos != UINT_MAX)
return IPP2P_BIT * 100 + 2;
- if (HX_memmem(payload, plen, "passkey=", 8) != NULL)
+
+ pos = textsearch_find_continuous(info->ts_conf_bt_passkey,
+ &state, &payload[5], plen - 5);
+ if (pos != UINT_MAX)
return IPP2P_BIT * 100 + 4;
return 0;
@@ -579,7 +618,8 @@ search_bittorrent(const unsigned char *payload, const unsigned int plen)
/* check for Kazaa get command */
static unsigned int
-search_kazaa(const unsigned char *payload, const unsigned int plen)
+search_kazaa(const unsigned char *payload, const unsigned int plen,
+ const struct ipt_p2p_info *info)
{
if (plen < 13)
return 0;
@@ -592,7 +632,8 @@ search_kazaa(const unsigned char *payload, const unsigned int plen)
/* check for gnutella get command */
static unsigned int
-search_gnu(const unsigned char *payload, const unsigned int plen)
+search_gnu(const unsigned char *payload, const unsigned int plen,
+ const struct ipt_p2p_info *info)
{
if (plen < 11)
return 0;
@@ -607,9 +648,11 @@ search_gnu(const unsigned char *payload, const unsigned int plen)
/* check for gnutella get commands and other typical data */
static unsigned int
-search_all_gnu(const unsigned char *payload, const unsigned int plen)
+search_all_gnu(const unsigned char *payload, const unsigned int plen,
+ const struct ipt_p2p_info *info)
{
- unsigned int c;
+ struct ts_state state;
+ unsigned int c, pos;
if (plen < 11)
return 0;
@@ -623,29 +666,34 @@ search_all_gnu(const unsigned char *payload, const unsigned int plen)
if (plen < 22)
return 0;
- if (memcmp(payload, "GET /get/", 9) != 0 &&
- memcmp(payload, "GET /uri-res/", 13) != 0)
+ if (memcmp(payload, "GET /get/", 9) == 0)
+ c = 9;
+ else if (memcmp(payload, "GET /uri-res/", 13) == 0)
+ c = 13;
+ else
return 0;
- for (c = 0; c < plen - 22; ++c) {
- if (!iscrlf(&payload[c]))
- continue;
+ pos = textsearch_find_continuous(info->ts_conf_gnu_x_gnutella,
+ &state, &payload[c], plen - c);
+ if (pos != UINT_MAX)
+ return IPP2P_GNU * 100 + 3;
- if (memcmp(&payload[c+2], "X-Gnutella-", 11) == 0)
- return IPP2P_GNU * 100 + 3;
+ pos = textsearch_find_continuous(info->ts_conf_gnu_x_queue,
+ &state, &payload[c], plen - c);
+ if (pos != UINT_MAX)
+ return IPP2P_GNU * 100 + 3;
- if ( memcmp(&payload[c+2], "X-Queue:", 8) == 0)
- return IPP2P_GNU * 100 + 3;
- }
return 0;
}
/* check for KaZaA download commands and other typical data */
/* plen is guaranteed to be >= 5 (see @matchlist) */
static unsigned int
-search_all_kazaa(const unsigned char *payload, const unsigned int plen)
+search_all_kazaa(const unsigned char *payload, const unsigned int plen,
+ const struct ipt_p2p_info *info)
{
- uint16_t c, end, rem;
+ struct ts_state state;
+ unsigned int pos;
if (plen < 7)
/* too short for anything we test for - early bailout */
@@ -664,25 +712,23 @@ search_all_kazaa(const unsigned char *payload, const unsigned int plen)
/* The next tests would not succeed anyhow. */
return 0;
- end = plen - 18;
- rem = plen - 5;
- for (c = 5; c < end; ++c, --rem) {
- if (!iscrlf(&payload[c]))
- continue;
- if (rem >= 18 &&
- memcmp(&payload[c+2], "X-Kazaa-Username: ", 18) == 0)
- return IPP2P_KAZAA * 100 + 2;
- if (rem >= 24 &&
- memcmp(&payload[c+2], "User-Agent: PeerEnabler/", 24) == 0)
- return IPP2P_KAZAA * 100 + 2;
- }
+ pos = textsearch_find_continuous(info->ts_conf_kz_x_kazaa_username,
+ &state, &payload[5], plen - 5);
+ if (pos != UINT_MAX)
+ return IPP2P_KAZAA * 100 + 2;
+
+ pos = textsearch_find_continuous(info->ts_conf_kz_user_agent,
+ &state, &payload[5], plen - 5);
+ if (pos != UINT_MAX)
+ return IPP2P_KAZAA * 100 + 2;
return 0;
}
/* fast check for edonkey file segment transfer command */
static unsigned int
-search_edk(const unsigned char *payload, const unsigned int plen)
+search_edk(const unsigned char *payload, const unsigned int plen,
+ const struct ipt_p2p_info *info)
{
if (plen < 6)
return 0;
@@ -695,7 +741,8 @@ search_edk(const unsigned char *payload, const unsigned int plen)
/* intensive but slower search for some edonkey packets including size-check */
static unsigned int
-search_all_edk(const unsigned char *payload, const unsigned int plen)
+search_all_edk(const unsigned char *payload, const unsigned int plen,
+ const struct ipt_p2p_info *info)
{
unsigned int cmd;
@@ -721,7 +768,8 @@ search_all_edk(const unsigned char *payload, const unsigned int plen)
/* fast check for Direct Connect send command */
static unsigned int
-search_dc(const unsigned char *payload, const unsigned int plen)
+search_dc(const unsigned char *payload, const unsigned int plen,
+ const struct ipt_p2p_info *info)
{
if (plen < 6)
return 0;
@@ -734,7 +782,8 @@ search_dc(const unsigned char *payload, const unsigned int plen)
/* intensive but slower check for all direct connect packets */
static unsigned int
-search_all_dc(const unsigned char *payload, const unsigned int plen)
+search_all_dc(const unsigned char *payload, const unsigned int plen,
+ const struct ipt_p2p_info *info)
{
const unsigned char *t;
@@ -765,7 +814,8 @@ search_all_dc(const unsigned char *payload, const unsigned int plen)
/* check for mute */
static unsigned int
-search_mute(const unsigned char *payload, const unsigned int plen)
+search_mute(const unsigned char *payload, const unsigned int plen,
+ const struct ipt_p2p_info *info)
{
if (plen == 209 || plen == 345 || plen == 473 || plen == 609 ||
plen == 1121) {
@@ -783,10 +833,11 @@ search_mute(const unsigned char *payload, const unsigned int plen)
/* check for xdcc */
static unsigned int
-search_xdcc(const unsigned char *payload, const unsigned int plen)
+search_xdcc(const unsigned char *payload, const unsigned int plen,
+ const struct ipt_p2p_info *info)
{
- uint16_t x = 10;
- const uint16_t end = plen - 13;
+ struct ts_state state;
+ unsigned int pos;
/* search in small packets only */
if (plen <= 20 || plen >= 200)
@@ -795,22 +846,19 @@ search_xdcc(const unsigned char *payload, const unsigned int plen)
if (memcmp(payload, "PRIVMSG ", 8) != 0 || !iscrlf(&payload[plen - 2]))
return 0;
- /*
- * is seems to be a irc private massage, chedck for
- * xdcc command
- */
- while (x < end) {
- if (payload[x] == ':' &&
- memcmp(&payload[x + 1], "xdcc send #", 11) == 0)
- return IPP2P_XDCC * 100 + 0;
- x++;
- }
+ /* seems to be a irc private massage, check for xdcc command */
+ pos = textsearch_find_continuous(info->ts_conf_xdcc,
+ &state, &payload[8], plen - 8);
+ if (pos != UINT_MAX)
+ return IPP2P_XDCC * 100 + 0;
+
return 0;
}
/* search for waste */
static unsigned int
-search_waste(const unsigned char *payload, const unsigned int plen)
+search_waste(const unsigned char *payload, const unsigned int plen,
+ const struct ipt_p2p_info *info)
{
if (plen >= 9 && memcmp(payload, "GET.sha1:", 9) == 0)
return IPP2P_WASTE * 100 + 0;
@@ -821,7 +869,8 @@ search_waste(const unsigned char *payload, const unsigned int plen)
static const struct {
unsigned int command;
unsigned int packet_len;
- unsigned int (*function_name)(const unsigned char *, const unsigned int);
+ unsigned int (*function_name)(const unsigned char *, const unsigned int,
+ const struct ipt_p2p_info *);
} matchlist[] = {
{IPP2P_EDK, 20, search_all_edk},
{IPP2P_DATA_KAZAA, 200, search_kazaa}, /* exp */
@@ -845,7 +894,8 @@ static const struct {
static const struct {
unsigned int command;
unsigned int packet_len;
- unsigned int (*function_name)(const unsigned char *, const unsigned int);
+ unsigned int (*function_name)(const unsigned char *, const unsigned int,
+ const struct ipt_p2p_info *);
} udp_list[] = {
{IPP2P_KAZAA, 14, udp_search_kazaa},
{IPP2P_BIT, 23, udp_search_bit},
@@ -901,7 +951,7 @@ ipp2p_mt_tcp(const struct ipt_p2p_info *info, const struct tcphdr *tcph,
continue;
if (hlen <= matchlist[i].packet_len)
continue;
- if (matchlist[i].function_name(haystack, hlen)) {
+ if (matchlist[i].function_name(haystack, hlen, info)) {
if (info->debug)
print_result(rp, true, hlen);
return true;
@@ -952,7 +1002,7 @@ ipp2p_mt_udp(const struct ipt_p2p_info *info, const struct udphdr *udph,
continue;
if (hlen <= udp_list[i].packet_len)
continue;
- if (udp_list[i].function_name(haystack, hlen)) {
+ if (udp_list[i].function_name(haystack, hlen, info)) {
if (info->debug)
print_result(rp, true, hlen);
return true;
@@ -1041,12 +1091,118 @@ ipp2p_mt(const struct sk_buff *skb, struct xt_action_param *par)
}
}
+static int ipp2p_mt_check(const struct xt_mtchk_param *par)
+{
+ struct ipt_p2p_info *info = par->matchinfo;
+ struct ts_config *ts_conf;
+
+ ts_conf = textsearch_prepare("bm", "\x20\x22", 2,
+ GFP_KERNEL, TS_AUTOLOAD);
+ if (IS_ERR(ts_conf))
+ goto err_return;
+ info->ts_conf_winmx = ts_conf;
+
+ ts_conf = textsearch_prepare("bm", "info_hash=", 10,
+ GFP_KERNEL, TS_AUTOLOAD);
+ if (IS_ERR(ts_conf))
+ goto err_ts_destroy_winmx;
+ info->ts_conf_bt_info_hash = ts_conf;
+
+ ts_conf = textsearch_prepare("bm", "peer_id=", 8,
+ GFP_KERNEL, TS_AUTOLOAD);
+ if (IS_ERR(ts_conf))
+ goto err_ts_destroy_bt_info_hash;
+ info->ts_conf_bt_peer_id = ts_conf;
+
+ ts_conf = textsearch_prepare("bm", "passkey", 8,
+ GFP_KERNEL, TS_AUTOLOAD);
+ if (IS_ERR(ts_conf))
+ goto err_ts_destroy_bt_peer_id;
+ info->ts_conf_bt_passkey = ts_conf;
+
+ ts_conf = textsearch_prepare("bm", "\r\nX-Gnutella-", 13,
+ GFP_KERNEL, TS_AUTOLOAD);
+ if (IS_ERR(ts_conf))
+ goto err_ts_destroy_bt_passkey;
+ info->ts_conf_gnu_x_gnutella = ts_conf;
+
+ ts_conf = textsearch_prepare("bm", "\r\nX-Queue-", 10,
+ GFP_KERNEL, TS_AUTOLOAD);
+ if (IS_ERR(ts_conf))
+ goto err_ts_destroy_gnu_x_gnutella;
+ info->ts_conf_gnu_x_queue = ts_conf;
+
+ ts_conf = textsearch_prepare("bm", "\r\nX-Kazaa-Username: ", 20,
+ GFP_KERNEL, TS_AUTOLOAD);
+ if (IS_ERR(ts_conf))
+ goto err_ts_destroy_gnu_x_queue;
+ info->ts_conf_kz_x_kazaa_username = ts_conf;
+
+ ts_conf = textsearch_prepare("bm", "\r\nUser-Agent: PeerEnabler/", 26,
+ GFP_KERNEL, TS_AUTOLOAD);
+ if (IS_ERR(ts_conf))
+ goto err_ts_destroy_kazaa_x_kazaa_username;
+ info->ts_conf_kz_user_agent = ts_conf;
+
+ ts_conf = textsearch_prepare("bm", ":xdcc send #", 12,
+ GFP_KERNEL, TS_AUTOLOAD);
+ if (IS_ERR(ts_conf))
+ goto err_ts_destroy_kazaa_user_agent;
+ info->ts_conf_xdcc = ts_conf;
+
+ return 0;
+
+err_ts_destroy_kazaa_user_agent:
+ textsearch_destroy(info->ts_conf_kz_user_agent);
+
+err_ts_destroy_kazaa_x_kazaa_username:
+ textsearch_destroy(info->ts_conf_kz_x_kazaa_username);
+
+err_ts_destroy_gnu_x_queue:
+ textsearch_destroy(info->ts_conf_gnu_x_queue);
+
+err_ts_destroy_gnu_x_gnutella:
+ textsearch_destroy(info->ts_conf_gnu_x_gnutella);
+
+err_ts_destroy_bt_passkey:
+ textsearch_destroy(info->ts_conf_bt_passkey);
+
+err_ts_destroy_bt_peer_id:
+ textsearch_destroy(info->ts_conf_bt_peer_id);
+
+err_ts_destroy_bt_info_hash:
+ textsearch_destroy(info->ts_conf_bt_info_hash);
+
+err_ts_destroy_winmx:
+ textsearch_destroy(info->ts_conf_winmx);
+
+err_return:
+ return PTR_ERR(ts_conf);
+}
+
+static void ipp2p_mt_destroy(const struct xt_mtdtor_param *par)
+{
+ struct ipt_p2p_info *info = (struct ipt_p2p_info *) par->matchinfo;
+
+ textsearch_destroy(info->ts_conf_winmx);
+ textsearch_destroy(info->ts_conf_bt_info_hash);
+ textsearch_destroy(info->ts_conf_bt_peer_id);
+ textsearch_destroy(info->ts_conf_bt_passkey);
+ textsearch_destroy(info->ts_conf_gnu_x_gnutella);
+ textsearch_destroy(info->ts_conf_gnu_x_queue);
+ textsearch_destroy(info->ts_conf_kz_x_kazaa_username);
+ textsearch_destroy(info->ts_conf_kz_user_agent);
+ textsearch_destroy(info->ts_conf_xdcc);
+}
+
static struct xt_match ipp2p_mt_reg[] __read_mostly = {
{
.name = "ipp2p",
.revision = 1,
.family = NFPROTO_IPV4,
+ .checkentry = ipp2p_mt_check,
.match = ipp2p_mt,
+ .destroy = ipp2p_mt_destroy,
.matchsize = sizeof(struct ipt_p2p_info),
.me = THIS_MODULE,
},
@@ -1054,7 +1210,9 @@ static struct xt_match ipp2p_mt_reg[] __read_mostly = {
.name = "ipp2p",
.revision = 1,
.family = NFPROTO_IPV6,
+ .checkentry = ipp2p_mt_check,
.match = ipp2p_mt,
+ .destroy = ipp2p_mt_destroy,
.matchsize = sizeof(struct ipt_p2p_info),
.me = THIS_MODULE,
},
diff --git a/extensions/xt_ipp2p.h b/extensions/xt_ipp2p.h
index f463f7f6e630..b821d75220b6 100644
--- a/extensions/xt_ipp2p.h
+++ b/extensions/xt_ipp2p.h
@@ -39,4 +39,14 @@ enum {
struct ipt_p2p_info {
int32_t cmd, debug;
+
+ struct ts_config *ts_conf_winmx;
+ struct ts_config *ts_conf_bt_info_hash;
+ struct ts_config *ts_conf_bt_peer_id;
+ struct ts_config *ts_conf_bt_passkey;
+ struct ts_config *ts_conf_gnu_x_gnutella;
+ struct ts_config *ts_conf_gnu_x_queue;
+ struct ts_config *ts_conf_kz_x_kazaa_username;
+ struct ts_config *ts_conf_kz_user_agent;
+ struct ts_config *ts_conf_xdcc;
};
--
2.39.2
