Use `skb_header_pointer` to copy byte-ranges for matching and
`skb_find_text` for substring searches. Doing so allows the module to
work with non-linear skbs.
Signed-off-by: Jeremy Sowden <jeremy@xxxxxxxxxx>
---
extensions/xt_ipp2p.c | 487 ++++++++++++++++++++++++++++++++----------
1 file changed, 372 insertions(+), 115 deletions(-)
diff --git a/extensions/xt_ipp2p.c b/extensions/xt_ipp2p.c
index 1378701605c3..def2d1ffc7bf 100644
--- a/extensions/xt_ipp2p.c
+++ b/extensions/xt_ipp2p.c
@@ -1,5 +1,6 @@
#include <linux/gfp.h>
#include <linux/module.h>
+#include <linux/skbuff.h>
#include <linux/textsearch.h>
#include <linux/version.h>
#include <linux/netfilter_ipv4/ip_tables.h>
@@ -38,7 +39,9 @@ ipv6_transport_len(const struct sk_buff *skb)
struct ipp2p_result_printer {
const union nf_inet_addr *saddr, *daddr;
short sport, dport;
- void (*print)(const union nf_inet_addr *, short, const union nf_inet_addr *, short, bool, unsigned int);
+ void (*print)(const union nf_inet_addr *, short,
+ const union nf_inet_addr *, short,
+ bool, unsigned int);
};
static bool iscrlf(const unsigned char *str)
@@ -57,12 +60,23 @@ 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 struct sk_buff *skb,
+ const unsigned int packet_off,
+ const unsigned int packet_len,
const struct ipt_p2p_info *info)
{
+ unsigned char buf[36], *t;
+
if (packet_len < 4)
return 0;
+ t = skb_header_pointer(skb, packet_off,
+ packet_len < sizeof(buf) ?
+ packet_len : sizeof(buf),
+ buf);
+ if (t == NULL)
+ return 0;
+
switch (t[0]) {
case 0xe3:
/* edonkey */
@@ -176,9 +190,20 @@ 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 struct sk_buff *skb,
+ const unsigned int packet_off,
+ const unsigned int packet_len,
const struct ipt_p2p_info *info)
{
+ unsigned char buf[9], *t;
+
+ t = skb_header_pointer(skb, packet_off,
+ packet_len < sizeof(buf) ?
+ packet_len : sizeof(buf),
+ buf);
+ if (t == NULL)
+ return 0;
+
if (packet_len >= 3 && memcmp(t, "GND", 3) == 0)
return IPP2P_GNU * 100 + 51;
if (packet_len >= 9 && memcmp(t, "GNUTELLA ", 9) == 0)
@@ -188,39 +213,73 @@ 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 struct sk_buff *skb,
+ const unsigned int packet_off,
+ const unsigned int packet_len,
const struct ipt_p2p_info *info)
{
+ unsigned char buf[6], *t;
+
if (packet_len < 6)
return 0;
- if (memcmp(t + packet_len - 6, "KaZaA\x00", 6) == 0)
+
+ t = skb_header_pointer(skb, packet_off + packet_len - 6, 6, buf);
+ if (t == NULL)
+ return 0;
+
+ if (memcmp(t, "KaZaA\x00", 6) == 0)
return IPP2P_KAZAA * 100 + 50;
return 0;
}
/* Search for UDP DirectConnect commands */
static unsigned int
-udp_search_directconnect(const unsigned char *t, const unsigned int packet_len,
+udp_search_directconnect(const struct sk_buff *skb,
+ const unsigned int packet_off,
+ const unsigned int packet_len,
const struct ipt_p2p_info *info)
{
+ unsigned char hbuf[6], *head, tbuf, *tail;
+
if (packet_len < 5)
return 0;
- if (t[0] != 0x24)
+
+ head = skb_header_pointer(skb, packet_off, packet_len < 7 ? 4 : 6,
+ hbuf);
+ if (head == NULL)
return 0;
- if (t[packet_len-1] != 0x7c)
+
+ tail = skb_header_pointer(skb, packet_off + packet_len - 1, 1, &tbuf);
+ if (tail == NULL)
return 0;
- if (memcmp(&t[1], "SR ", 3) == 0)
+
+ if (head[0] != 0x24)
+ return 0;
+ if (tail[0] != 0x7c)
+ return 0;
+ if (memcmp(&head[1], "SR ", 3) == 0)
return IPP2P_DC * 100 + 60;
- if (packet_len >= 7 && memcmp(&t[1], "Ping ", 5) == 0)
+ if (packet_len >= 7 && memcmp(&head[1], "Ping ", 5) == 0)
return IPP2P_DC * 100 + 61;
return 0;
}
/* Search for UDP BitTorrent commands */
static unsigned int
-udp_search_bit(const unsigned char *haystack, const unsigned int packet_len,
+udp_search_bit(const struct sk_buff *skb,
+ const unsigned int packet_off,
+ const unsigned int packet_len,
const struct ipt_p2p_info *info)
{
+ unsigned char buf[32], *haystack;
+
+ haystack = skb_header_pointer(skb, packet_off,
+ packet_len < sizeof(buf) ?
+ packet_len : sizeof(buf),
+ buf);
+ if (haystack == NULL)
+ return 0;
+
switch (packet_len) {
case 16:
/* ^ 00 00 04 17 27 10 19 80 */
@@ -305,11 +364,22 @@ 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 struct sk_buff *skb,
+ const unsigned int poff,
+ const unsigned int plen,
const struct ipt_p2p_info *info)
{
+ unsigned char buf[60], *payload;
+
if (plen < 3)
return 0;
+
+ payload = skb_header_pointer(skb, poff,
+ plen < sizeof(buf) ? plen : sizeof(buf),
+ buf);
+ if (payload == NULL)
+ return 0;
+
/* all ares packets start with */
if (payload[1] == 0 && plen - payload[0] == 3) {
switch (payload[2]) {
@@ -358,11 +428,22 @@ 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 struct sk_buff *skb,
+ const unsigned int poff,
+ const unsigned int plen,
const struct ipt_p2p_info *info)
{
+ unsigned char buf[16], *payload;
+
if (plen < 8)
return 0;
+
+ payload = skb_header_pointer(skb, poff,
+ plen < sizeof(buf) ? plen : sizeof(buf),
+ buf);
+ if (payload == NULL)
+ return 0;
+
/* match: xx xx xx xx | xx = sizeof(payload) - 4 */
if (get_u32(payload, 0) == plen - 4) {
const uint32_t m = get_u32(payload, 4);
@@ -461,12 +542,20 @@ search_soul(const unsigned char *payload, const unsigned int plen,
if (get_u32(payload, 0) == 0x14 && get_u8(payload, 4) == 0x01) {
uint32_t y = get_u32(payload, 5);
const unsigned char *w;
+ unsigned int off, len;
/* we need 19 chars + string */
if (plen < y + 19)
return 0;
- w = payload + 9 + y;
+ off = poff + y + 9;
+ len = plen - y + 9;
+
+ w = skb_header_pointer(skb, off,
+ len < sizeof(buf) ? len : sizeof(buf),
+ buf);
+ if (w == NULL)
+ return 0;
if (get_u32(w, 0) == 0x01 &&
(get_u16(w, 4) == 0x4600 ||
@@ -483,10 +572,19 @@ 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 struct sk_buff *skb,
+ const unsigned int poff,
+ const unsigned int plen,
const struct ipt_p2p_info *info)
{
- uint16_t start;
+ unsigned char buf[149], *payload;
+ uint16_t start = poff;
+
+ payload = skb_header_pointer(skb, poff,
+ plen < sizeof(buf) ? plen : sizeof(buf),
+ buf);
+ if (payload == NULL)
+ return 0;
if (plen == 4 && memcmp(payload, "SEND", 4) == 0)
return IPP2P_WINMX * 100 + 1;
@@ -500,23 +598,18 @@ search_winmx(const unsigned char *payload, const unsigned int plen,
return 0;
if (memcmp(payload, "SEND", 4) == 0)
- start = 4;
+ start += 4;
else if (memcmp(payload, "GET", 3) == 0)
- start = 3;
- else
- start = 0;
+ start += 3;
- if (start) {
+ if (start > poff) {
uint8_t count = 0;
do {
- struct ts_state state;
unsigned int pos;
- pos = textsearch_find_continuous(info->ts_conf_winmx,
- &state,
- &payload[start],
- plen - start);
+ pos = skb_find_text((struct sk_buff *)skb, start,
+ skb->len, info->ts_conf_winmx);
if (pos == UINT_MAX)
break;
@@ -525,7 +618,7 @@ search_winmx(const unsigned char *payload, const unsigned int plen,
return IPP2P_WINMX * 100 + 3;
start = pos + 2;
- } while (start < plen);
+ } while (start < skb->len);
}
if (plen == 149 && payload[0] == '8') {
@@ -553,11 +646,22 @@ 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 struct sk_buff *skb,
+ const unsigned int poff,
+ const unsigned int plen,
const struct ipt_p2p_info *info)
{
+ unsigned char buf[8], *payload;
+
if (plen < 8)
return 0;
+
+ payload = skb_header_pointer(skb, poff,
+ plen < sizeof(buf) ? plen : sizeof(buf),
+ buf);
+ if (payload == NULL)
+ return 0;
+
if (memcmp(payload, "ajprot\r\n", 8) == 0)
return IPP2P_APPLE * 100;
return 0;
@@ -565,12 +669,20 @@ 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 struct sk_buff *skb,
+ const unsigned int poff,
+ const unsigned int plen,
const struct ipt_p2p_info *info)
{
- struct ts_state state;
+ unsigned char buf[20], *payload;
unsigned int pos;
+ payload = skb_header_pointer(skb, poff,
+ plen < sizeof(buf) ? plen : sizeof(buf),
+ buf);
+ if (payload == NULL)
+ return 0;
+
/*
* bitcomet encrypts the first packet, so we have to detect another one
* later in the flow.
@@ -598,18 +710,18 @@ search_bittorrent(const unsigned char *payload, const unsigned int plen,
if (memcmp(payload, "GET /", 5) != 0)
return 0;
- pos = textsearch_find_continuous(info->ts_conf_bt_info_hash,
- &state, &payload[5], plen - 5);
+ pos = skb_find_text((struct sk_buff *)skb, poff + 5, skb->len,
+ info->ts_conf_bt_info_hash);
if (pos != UINT_MAX)
return IPP2P_BIT * 100 + 1;
- pos = textsearch_find_continuous(info->ts_conf_bt_peer_id,
- &state, &payload[5], plen - 5);
+ pos = skb_find_text((struct sk_buff *)skb, poff + 5, skb->len,
+ info->ts_conf_bt_peer_id);
if (pos != UINT_MAX)
return IPP2P_BIT * 100 + 2;
- pos = textsearch_find_continuous(info->ts_conf_bt_passkey,
- &state, &payload[5], plen - 5);
+ pos = skb_find_text((struct sk_buff *)skb, poff + 5, skb->len,
+ info->ts_conf_bt_passkey);
if (pos != UINT_MAX)
return IPP2P_BIT * 100 + 4;
@@ -618,13 +730,25 @@ 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 struct sk_buff *skb,
+ const unsigned int poff,
+ const unsigned int plen,
const struct ipt_p2p_info *info)
{
+ unsigned char hbuf[11], *head, tbuf[2], *tail;
+
if (plen < 13)
return 0;
- if (iscrlf(&payload[plen - 2]) &&
- memcmp(payload, "GET /.hash=", 11) == 0)
+
+ head = skb_header_pointer(skb, poff, 11, hbuf);
+ if (head == NULL)
+ return 0;
+
+ tail = skb_header_pointer(skb, poff + plen - 2, 2, tbuf);
+ if (tail == NULL)
+ return 0;
+
+ if (iscrlf(tail) && memcmp(head, "GET /.hash=", 11) == 0)
return IPP2P_DATA_KAZAA * 100;
return 0;
@@ -632,54 +756,87 @@ 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 struct sk_buff *skb,
+ const unsigned int poff,
+ const unsigned int plen,
const struct ipt_p2p_info *info)
{
+ unsigned char hbuf[15], *head, tbuf[2], *tail;
+
if (plen < 11)
return 0;
- if (!iscrlf(&payload[plen - 2]))
+
+ head = skb_header_pointer(skb, poff,
+ plen - 2 < sizeof(hbuf) ?
+ plen - 2 : sizeof(hbuf),
+ hbuf);
+ if (head == NULL)
+ return 0;
+
+ tail = skb_header_pointer(skb, poff + plen - 2, 2, tbuf);
+ if (tail == NULL)
+ return 0;
+
+ if (!iscrlf(tail))
return 0;
- if (memcmp(payload, "GET /get/", 9) == 0)
+ if (memcmp(head, "GET /get/", 9) == 0)
return IPP2P_DATA_GNU * 100 + 1;
- if (plen >= 15 && memcmp(payload, "GET /uri-res/", 13) == 0)
+ if (plen >= 15 && memcmp(head, "GET /uri-res/", 13) == 0)
return IPP2P_DATA_GNU * 100 + 2;
return 0;
}
/* 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 struct sk_buff *skb,
+ const unsigned int poff,
+ const unsigned int plen,
const struct ipt_p2p_info *info)
{
- struct ts_state state;
- unsigned int c, pos;
+ unsigned char hbuf[17], *head, tbuf[2], *tail;
+ unsigned int off, pos;
if (plen < 11)
return 0;
- if (!iscrlf(&payload[plen - 2]))
+
+ head = skb_header_pointer(skb, poff,
+ plen - 2 < sizeof(hbuf) ?
+ plen - 2 : sizeof(hbuf),
+ hbuf);
+ if (head == NULL)
+ return 0;
+
+ tail = skb_header_pointer(skb, poff + plen - 2, 2, tbuf);
+ if (tail == NULL)
return 0;
- if (plen >= 19 && memcmp(payload, "GNUTELLA CONNECT/", 17) == 0)
+
+ if (!iscrlf(tail))
+ return 0;
+
+ if (plen >= 19 && memcmp(head, "GNUTELLA CONNECT/", 17) == 0)
return IPP2P_GNU * 100 + 1;
- if (memcmp(payload, "GNUTELLA/", 9) == 0)
+
+ if (memcmp(head, "GNUTELLA/", 9) == 0)
return IPP2P_GNU * 100 + 2;
if (plen < 22)
return 0;
- if (memcmp(payload, "GET /get/", 9) == 0)
- c = 9;
- else if (memcmp(payload, "GET /uri-res/", 13) == 0)
- c = 13;
+ if (memcmp(head, "GET /get/", 9) == 0)
+ off = 9;
+ else if (memcmp(head, "GET /uri-res/", 13) == 0)
+ off = 13;
else
return 0;
- pos = textsearch_find_continuous(info->ts_conf_gnu_x_gnutella,
- &state, &payload[c], plen - c);
+ pos = skb_find_text((struct sk_buff *)skb, poff + off, skb->len,
+ info->ts_conf_gnu_x_gnutella);
if (pos != UINT_MAX)
return IPP2P_GNU * 100 + 3;
- pos = textsearch_find_continuous(info->ts_conf_gnu_x_queue,
- &state, &payload[c], plen - c);
+ pos = skb_find_text((struct sk_buff *)skb, poff + off, skb->len,
+ info->ts_conf_gnu_x_queue);
+
if (pos != UINT_MAX)
return IPP2P_GNU * 100 + 3;
@@ -689,36 +846,46 @@ search_all_gnu(const unsigned char *payload, const unsigned int plen,
/* 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 struct sk_buff *skb,
+ const unsigned int poff,
+ const unsigned int plen,
const struct ipt_p2p_info *info)
{
- struct ts_state state;
+ unsigned char hbuf[5], *head, tbuf[2], *tail;
unsigned int pos;
if (plen < 7)
/* too short for anything we test for - early bailout */
return 0;
- if (!iscrlf(&payload[plen - 2]))
+ head = skb_header_pointer(skb, poff, sizeof(hbuf), hbuf);
+ if (head == NULL)
+ return 0;
+
+ tail = skb_header_pointer(skb, poff + plen - 2, 2, tbuf);
+ if (tail == NULL)
return 0;
- if (memcmp(payload, "GIVE ", 5) == 0)
+ if (!iscrlf(tail))
+ return 0;
+
+ if (memcmp(head, "GIVE ", 5) == 0)
return IPP2P_KAZAA * 100 + 1;
- if (memcmp(payload, "GET /", 5) != 0)
+ if (memcmp(head, "GET /", 5) != 0)
return 0;
if (plen < 18)
/* The next tests would not succeed anyhow. */
return 0;
- pos = textsearch_find_continuous(info->ts_conf_kz_x_kazaa_username,
- &state, &payload[5], plen - 5);
+ pos = skb_find_text((struct sk_buff *)skb, poff + 5, skb->len,
+ info->ts_conf_kz_x_kazaa_username);
if (pos != UINT_MAX)
return IPP2P_KAZAA * 100 + 2;
- pos = textsearch_find_continuous(info->ts_conf_kz_user_agent,
- &state, &payload[5], plen - 5);
+ pos = skb_find_text((struct sk_buff *)skb, poff + 5, skb->len,
+ info->ts_conf_kz_user_agent);
if (pos != UINT_MAX)
return IPP2P_KAZAA * 100 + 2;
@@ -727,11 +894,20 @@ search_all_kazaa(const unsigned char *payload, const unsigned int plen,
/* fast check for edonkey file segment transfer command */
static unsigned int
-search_edk(const unsigned char *payload, const unsigned int plen,
+search_edk(const struct sk_buff *skb,
+ const unsigned int poff,
+ const unsigned int plen,
const struct ipt_p2p_info *info)
{
+ unsigned char buf[6], *payload;
+
if (plen < 6)
return 0;
+
+ payload = skb_header_pointer(skb, poff, sizeof(buf), buf);
+ if (payload == NULL)
+ return 0;
+
if (payload[0] != 0xe3)
return 0;
if (payload[5] == 0x47)
@@ -741,13 +917,21 @@ 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 struct sk_buff *skb,
+ const unsigned int poff,
+ const unsigned int plen,
const struct ipt_p2p_info *info)
{
+ unsigned char buf[6], *payload;
unsigned int cmd;
if (plen < 6)
return 0;
+
+ payload = skb_header_pointer(skb, poff, sizeof(buf), buf);
+ if (payload == NULL)
+ return 0;
+
if (payload[0] != 0xe3)
return 0;
@@ -768,11 +952,20 @@ 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 struct sk_buff *skb,
+ const unsigned int poff,
+ const unsigned int plen,
const struct ipt_p2p_info *info)
{
+ unsigned char buf[6], *payload;
+
if (plen < 6)
return 0;
+
+ payload = skb_header_pointer(skb, poff, sizeof(buf), buf);
+ if (payload == NULL)
+ return 0;
+
if (payload[0] != 0x24)
return 0;
if (memcmp(&payload[1], "Send|", 5) == 0)
@@ -782,21 +975,35 @@ 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 struct sk_buff *skb,
+ const unsigned int poff,
+ const unsigned int plen,
const struct ipt_p2p_info *info)
{
+ unsigned char hbuf[8], *head, tbuf, *tail;
const unsigned char *t;
if (plen < 7)
return 0;
- if (payload[0] != 0x24)
+ head = skb_header_pointer(skb, poff,
+ plen - 1 < sizeof(hbuf) ?
+ plen - 1 : sizeof(hbuf),
+ hbuf);
+ if (head == NULL)
return 0;
- if (payload[plen-1] != 0x7c)
+ tail = skb_header_pointer(skb, poff + plen - 1, 1, &tbuf);
+ if (tail == NULL)
return 0;
- t = &payload[1];
+ if (head[0] != 0x24)
+ return 0;
+
+ if (tail[0] != 0x7c)
+ return 0;
+
+ t = &head[1];
/* Client-Hub-Protocol */
if (memcmp(t, "Lock ", 5) == 0)
@@ -814,18 +1021,21 @@ 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 struct sk_buff *skb,
+ const unsigned int poff,
+ const unsigned int plen,
const struct ipt_p2p_info *info)
{
if (plen == 209 || plen == 345 || plen == 473 || plen == 609 ||
plen == 1121) {
- //printk(KERN_DEBUG "size hit: %u", size);
+ unsigned char buf[11], *payload;
+
+ payload = skb_header_pointer(skb, poff, sizeof(buf), buf);
+ if (payload == NULL)
+ return 0;
+
if (memcmp(payload,"PublicKey: ", 11) == 0) {
return IPP2P_MUTE * 100 + 0;
- /*
- if (memcmp(t + size - 14, "\x0aEndPublicKey\x0a", 14) == 0)
- printk(KERN_DEBUG "end pubic key hit: %u", size);
- */
}
}
return 0;
@@ -833,22 +1043,35 @@ 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 struct sk_buff *skb,
+ const unsigned int poff,
+ const unsigned int plen,
const struct ipt_p2p_info *info)
{
- struct ts_state state;
+ unsigned char hbuf[8], *head, tbuf[2], *tail;
unsigned int pos;
/* search in small packets only */
if (plen <= 20 || plen >= 200)
return 0;
- if (memcmp(payload, "PRIVMSG ", 8) != 0 || !iscrlf(&payload[plen - 2]))
+ head = skb_header_pointer(skb, poff,
+ plen - 2 < sizeof(hbuf) ?
+ plen - 2 : sizeof(hbuf),
+ hbuf);
+ if (head == NULL)
+ return 0;
+
+ tail = skb_header_pointer(skb, poff + plen - 2, 2, &tbuf);
+ if (tail == NULL)
+ return 0;
+
+ if (memcmp(head, "PRIVMSG ", 8) != 0 || !iscrlf(tail))
return 0;
/* seems to be a irc private massage, check for xdcc command */
- pos = textsearch_find_continuous(info->ts_conf_xdcc,
- &state, &payload[8], plen - 8);
+ pos = skb_find_text((struct sk_buff *)skb, poff + 8, skb->len,
+ info->ts_conf_xdcc);
if (pos != UINT_MAX)
return IPP2P_XDCC * 100 + 0;
@@ -857,10 +1080,23 @@ search_xdcc(const unsigned char *payload, const unsigned int plen,
/* search for waste */
static unsigned int
-search_waste(const unsigned char *payload, const unsigned int plen,
+search_waste(const struct sk_buff *skb,
+ const unsigned int poff,
+ const unsigned int plen,
const struct ipt_p2p_info *info)
{
- if (plen >= 9 && memcmp(payload, "GET.sha1:", 9) == 0)
+ unsigned char buf[9], *payload;
+
+ if (plen < 9)
+ return 0;
+
+ payload = skb_header_pointer(skb, poff,
+ plen < sizeof(buf) ? plen : sizeof(buf),
+ buf);
+ if (payload == NULL)
+ return 0;
+
+ if (memcmp(payload, "GET.sha1:", 9) == 0)
return IPP2P_WASTE * 100 + 0;
return 0;
@@ -869,7 +1105,9 @@ 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 struct sk_buff *,
+ const unsigned int,
+ const unsigned int,
const struct ipt_p2p_info *);
} matchlist[] = {
{IPP2P_EDK, 20, search_all_edk},
@@ -894,7 +1132,9 @@ 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 struct sk_buff *,
+ const unsigned int,
+ const unsigned int,
const struct ipt_p2p_info *);
} udp_list[] = {
{IPP2P_KAZAA, 14, udp_search_kazaa},
@@ -925,8 +1165,9 @@ ipp2p_print_result_tcp6(const union nf_inet_addr *saddr, short sport,
static bool
ipp2p_mt_tcp(const struct ipt_p2p_info *info, const struct tcphdr *tcph,
- const unsigned char *haystack, unsigned int hlen,
- const struct ipp2p_result_printer *rp)
+ const struct sk_buff *skb, unsigned int packet_off,
+ unsigned int packet_len,
+ const struct ipp2p_result_printer *rp)
{
size_t tcph_len = tcph->doff * 4;
int i;
@@ -935,25 +1176,26 @@ ipp2p_mt_tcp(const struct ipt_p2p_info *info, const struct tcphdr *tcph,
if (tcph->syn) return 0; /* if SYN bit is set bail out */
if (tcph->rst) return 0; /* if RST bit is set bail out */
- if (hlen < tcph_len) {
+ if (packet_len < tcph_len) {
if (info->debug)
pr_info("TCP header indicated packet larger than it is\n");
return 0;
}
- if (hlen == tcph_len)
+ if (packet_len == tcph_len)
return 0;
- haystack += tcph_len;
- hlen -= tcph_len;
+ packet_off += tcph_len;
+ packet_len -= tcph_len;
for (i = 0; matchlist[i].command; ++i) {
if ((info->cmd & matchlist[i].command) != matchlist[i].command)
continue;
- if (hlen <= matchlist[i].packet_len)
+ if (packet_len <= matchlist[i].packet_len)
continue;
- if (matchlist[i].function_name(haystack, hlen, info)) {
+ if (matchlist[i].function_name(skb, packet_off, packet_len,
+ info)) {
if (info->debug)
- print_result(rp, true, hlen);
+ print_result(rp, true, packet_len);
return true;
}
}
@@ -980,31 +1222,33 @@ ipp2p_print_result_udp6(const union nf_inet_addr *saddr, short sport,
static bool
ipp2p_mt_udp(const struct ipt_p2p_info *info, const struct udphdr *udph,
- const unsigned char *haystack, unsigned int hlen,
- const struct ipp2p_result_printer *rp)
+ const struct sk_buff *skb, unsigned int packet_off,
+ unsigned int packet_len,
+ const struct ipp2p_result_printer *rp)
{
size_t udph_len = sizeof(*udph);
int i;
- if (hlen < udph_len) {
+ if (packet_len < udph_len) {
if (info->debug)
pr_info("UDP header indicated packet larger than it is\n");
return 0;
}
- if (hlen == udph_len)
+ if (packet_len == udph_len)
return 0;
- haystack += udph_len;
- hlen -= udph_len;
+ packet_off += udph_len;
+ packet_len -= udph_len;
for (i = 0; udp_list[i].command; ++i) {
if ((info->cmd & udp_list[i].command) != udp_list[i].command)
continue;
- if (hlen <= udp_list[i].packet_len)
+ if (packet_len <= udp_list[i].packet_len)
continue;
- if (udp_list[i].function_name(haystack, hlen, info)) {
+ if (udp_list[i].function_name(skb, packet_off, packet_len,
+ info)) {
if (info->debug)
- print_result(rp, true, hlen);
+ print_result(rp, true, packet_len);
return true;
}
}
@@ -1017,9 +1261,8 @@ ipp2p_mt(const struct sk_buff *skb, struct xt_action_param *par)
const struct ipt_p2p_info *info = par->matchinfo;
struct ipp2p_result_printer printer;
union nf_inet_addr saddr, daddr;
- const unsigned char *haystack; /* packet data */
- unsigned int hlen; /* packet data length */
uint8_t family = xt_family(par);
+ unsigned int packet_len;
int protocol;
/*
@@ -1044,10 +1287,11 @@ ipp2p_mt(const struct sk_buff *skb, struct xt_action_param *par)
if (family == NFPROTO_IPV4) {
const struct iphdr *ip = ip_hdr(skb);
+
saddr.ip = ip->saddr;
daddr.ip = ip->daddr;
protocol = ip->protocol;
- hlen = ip_transport_len(skb);
+ packet_len = ip_transport_len(skb);
} else {
const struct ipv6hdr *ip = ipv6_hdr(skb);
int thoff = 0;
@@ -1057,34 +1301,47 @@ ipp2p_mt(const struct sk_buff *skb, struct xt_action_param *par)
protocol = ipv6_find_hdr(skb, &thoff, -1, NULL, NULL);
if (protocol < 0)
return 0;
- hlen = ipv6_transport_len(skb);
+ packet_len = ipv6_transport_len(skb);
}
printer.saddr = &saddr;
printer.daddr = &daddr;
- haystack = skb_transport_header(skb);
switch (protocol) {
case IPPROTO_TCP: /* what to do with a TCP packet */
{
- const struct tcphdr *tcph = tcp_hdr(skb);
+ const struct tcphdr *tcph;
+ struct tcphdr _tcph;
+
+ tcph = skb_header_pointer(skb, par->thoff, sizeof(_tcph), &_tcph);
+ if (tcph == NULL)
+ return 0;
printer.sport = ntohs(tcph->source);
printer.dport = ntohs(tcph->dest);
printer.print = family == NFPROTO_IPV6 ?
ipp2p_print_result_tcp6 : ipp2p_print_result_tcp4;
- return ipp2p_mt_tcp(info, tcph, haystack, hlen, &printer);
+
+ return ipp2p_mt_tcp(info, tcph, skb, par->thoff, packet_len,
+ &printer);
}
case IPPROTO_UDP: /* what to do with a UDP packet */
case IPPROTO_UDPLITE:
{
- const struct udphdr *udph = udp_hdr(skb);
+ const struct udphdr *udph;
+ struct udphdr _udph;
+
+ udph = skb_header_pointer(skb, par->thoff, sizeof(_udph), &_udph);
+ if (udph == NULL)
+ return 0;
printer.sport = ntohs(udph->source);
printer.dport = ntohs(udph->dest);
printer.print = family == NFPROTO_IPV6 ?
ipp2p_print_result_udp6 : ipp2p_print_result_udp4;
- return ipp2p_mt_udp(info, udph, haystack, hlen, &printer);
+
+ return ipp2p_mt_udp(info, udph, skb, par->thoff, packet_len,
+ &printer);
}
default:
return 0;
--
2.39.2
