ipt_ipp2p.c

通过linux操作系统限制P2P的流量的源代码

#if defined(MODVERSIONS)
#include <linux/modversions.h>
#endif
#include <linux/module.h>
#include <linux/netfilter_ipv4/ip_tables.h>
#include <linux/version.h>
//#include <linux/netfilter_ipv4/ipt_ipp2p.h>
#include "ipt_ipp2p.h"
#include <net/tcp.h>
#include <net/udp.h>

#define get_u8(X,O)  (*(__u8 *)(X + O))
#define get_u16(X,O)  (*(__u16 *)(X + O))
#define get_u32(X,O)  (*(__u32 *)(X + O))

MODULE_AUTHOR("Eicke Friedrich/Klaus Degner <[e-mail]>");
MODULE_DESCRIPTION("An extension to iptables to identify P2P traffic.");
MODULE_LICENSE("GPL");


/*Search for UDP eDonkey/eMule/Kad commands*/
int
udp_search_edk (unsigned char *haystack, int packet_len)
{
    unsigned char *t = haystack;
    t += 8;

	switch (t[0]) {
		case 0xe3: 
		{	/*edonkey*/
			switch (t[1]) 
			{
				/* client -> server status request */
				case 0x96: 
					if (packet_len == 14) return ((IPP2P_EDK * 100) + 50);
					break;
				/* server -> client status request */
				case 0x97: if (packet_len == 42) return ((IPP2P_EDK * 100) + 51);
					break;
						/* server description request */
						/* e3 2a ff f0 .. | size == 6 */
				case 0xa2: if ( (packet_len == 14) && ( get_u16(t,2) == __constant_htons(0xfff0) ) ) return ((IPP2P_EDK * 100) + 52);
					break;
						/* server description response */
						/* e3 a3 ff f0 ..  | size > 40 && size < 200 */
				//case 0xa3: return ((IPP2P_EDK * 100) + 53);
				//	break;
				case 0x9a: if (packet_len==26) return ((IPP2P_EDK * 100) + 54);
					break;

				case 0x92: if (packet_len==18) return ((IPP2P_EDK * 100) + 55);
					break;
			}
			break;
		}
		case 0xe4: 
		{
			switch (t[1]) 
			{
						/* e4 20 .. | size == 43 */
				case 0x20: if ((packet_len == 43) && (t[2] != 0x00) && (t[34] != 0x00)) return ((IPP2P_EDK * 100) + 60);
					break;
						/* e4 00 .. 00 | size == 35 ? */
				case 0x00: if ((packet_len == 35) && (t[26] == 0x00)) return ((IPP2P_EDK * 100) + 61);
					break;
						/* e4 10 .. 00 | size == 35 ? */
				case 0x10: if ((packet_len == 35) && (t[26] == 0x00)) return ((IPP2P_EDK * 100) + 62);
					break;
						/* e4 18 .. 00 | size == 35 ? */
				case 0x18: if ((packet_len == 35) && (t[26] == 0x00)) return ((IPP2P_EDK * 100) + 63);
					break;
						/* e4 52 .. | size = 44 */
				case 0x52: if (packet_len == 44 ) return ((IPP2P_EDK * 100) + 64);
					break;
						/* e4 58 .. | size == 6 */
				case 0x58: if (packet_len == 14 ) return ((IPP2P_EDK * 100) + 65);
					break;
						/* e4 59 .. | size == 2 */
				case 0x59: if (packet_len == 10 )return ((IPP2P_EDK * 100) + 66);
					break;
					/* e4 28 .. | packet_len == 52,77,102,127... */
				case 0x28: if (((packet_len-52) % 25) == 0) return ((IPP2P_EDK * 100) + 67);
					break;
					/* e4 50 xx xx | size == 4 */
				case 0x50: if (packet_len == 12) return ((IPP2P_EDK * 100) + 68);
					break;
					/* e4 40 xx xx | size == 48 */
				case 0x40: if (packet_len == 56) return ((IPP2P_EDK * 100) + 69);
					break;
			}
			break;
		}
	} /* end of switch (t[0]) */
    return 0;
}/*udp_search_edk*/


/*Search for UDP Gnutella commands*/
int
udp_search_gnu (unsigned char *haystack, int packet_len)
{
    unsigned char *t = haystack;
    t += 8;
    
    if (memcmp(t, "GND", 3) == 0) return ((IPP2P_GNU * 100) + 51);
    if (memcmp(t, "GNUTELLA ", 9) == 0) return ((IPP2P_GNU * 100) + 52);
    return 0;
}/*udp_search_gnu*/


/*Search for UDP KaZaA commands*/
int
udp_search_kazaa (unsigned char *haystack, int packet_len)
{
    unsigned char *t = haystack;
    
    if (t[packet_len-1] == 0x00){
	t += (packet_len - 6);
	if (memcmp(t, "KaZaA", 5) == 0) return (IPP2P_KAZAA * 100 +50);
    }
    
    return 0;
}/*udp_search_kazaa*/

/*Search for UDP DirectConnect commands*/
int
udp_search_directconnect (unsigned char *haystack, int packet_len)
{
    unsigned char *t = haystack;
    if ((*(t + 8) == 0x24) && (*(t + packet_len - 1) == 0x7c)) {
    	t+=8;
    	if (memcmp(t, "SR ", 3) == 0)	 		return ((IPP2P_DC * 100) + 60);
    	if (memcmp(t, "Ping ", 5) == 0)	 		return ((IPP2P_DC * 100) + 61);
    }
    return 0;
}/*udp_search_directconnect*/



/*Search for UDP BitTorrent commands*/
int
udp_search_bit (unsigned char *haystack, int packet_len)
{
	switch(packet_len)
	{
		case 24:
			/* ^ 00 00 04 17 27 10 19 80 */
			if ((ntohl(get_u32(haystack, 8)) == 0x00000417) && (ntohl(get_u32(haystack, 12)) == 0x27101980)) 
				return (IPP2P_BIT * 100 + 50);
			break;
		case 44:
			if (get_u32(haystack, 16) == __constant_htonl(0x00000400) && get_u32(haystack, 36) == __constant_htonl(0x00000104)) 
				return (IPP2P_BIT * 100 + 51);
			if (get_u32(haystack, 16) == __constant_htonl(0x00000400))
				return (IPP2P_BIT * 100 + 61);
			break;
		case 65:
			if (get_u32(haystack, 16) == __constant_htonl(0x00000404) && get_u32(haystack, 36) == __constant_htonl(0x00000104)) 
				return (IPP2P_BIT * 100 + 52);
			if (get_u32(haystack, 16) == __constant_htonl(0x00000404))
				return (IPP2P_BIT * 100 + 62);
			break;
		case 67:
			if (get_u32(haystack, 16) == __constant_htonl(0x00000406) && get_u32(haystack, 36) == __constant_htonl(0x00000104)) 
				return (IPP2P_BIT * 100 + 53);
			if (get_u32(haystack, 16) == __constant_htonl(0x00000406))
				return (IPP2P_BIT * 100 + 63);
			break;
		case 211:
			if (get_u32(haystack, 8) == __constant_htonl(0x00000405)) 
				return (IPP2P_BIT * 100 + 54);
			break;
		case 29:
			if ((get_u32(haystack, 8) == __constant_htonl(0x00000401))) 
				return (IPP2P_BIT * 100 + 55);
			break;
		case 52:
			if (get_u32(haystack,8)  == __constant_htonl(0x00000827) &&
			get_u32(haystack,12) == __constant_htonl(0x37502950))
				return (IPP2P_BIT * 100 + 80);
			break;
		default:
			/* this packet does not have a constant size */
			if (packet_len >= 40 && get_u32(haystack, 16) == __constant_htonl(0x00000402) && get_u32(haystack, 36) == __constant_htonl(0x00000104)) 
				return (IPP2P_BIT * 100 + 56);
			break;
	}
    
	/* some extra-bitcomet rules:
	* "d1:" [a|r] "d2:id20:"
	*/
	if (packet_len > 30 && get_u8(haystack, 8) == 'd' && get_u8(haystack, 9) == '1' && get_u8(haystack, 10) == ':' )
	{
		if (get_u8(haystack, 11) == 'a' || get_u8(haystack, 11) == 'r')
		{
			if (memcmp(haystack+12,"d2:id20:",8)==0)
				return (IPP2P_BIT * 100 + 57);
		}
	}
    
#if 0
	/* bitlord rules */
	/* packetlen must be bigger than 40 */
	/* first 4 bytes are zero */
	if (packet_len > 40 && get_u32(haystack, 8) == 0x00000000)
	{
		/* first rule: 00 00 00 00 01 00 00 xx xx xx xx 00 00 00 00*/
		if (get_u32(haystack, 12) == 0x00000000 && 
		    get_u32(haystack, 16) == 0x00010000 &&
		    get_u32(haystack, 24) == 0x00000000 )
			return (IPP2P_BIT * 100 + 71);
			
		/* 00 01 00 00 0d 00 00 xx xx xx xx 00 00 00 00*/
		if (get_u32(haystack, 12) == 0x00000001 && 
		    get_u32(haystack, 16) == 0x000d0000 &&
		    get_u32(haystack, 24) == 0x00000000 )
			return (IPP2P_BIT * 100 + 71);
		
		    
	}
#endif

    return 0;
}/*udp_search_bit*/



/*Search for Ares commands*/
//#define IPP2P_DEBUG_ARES
int
search_ares (const unsigned char *payload, const u16 plen)
//int search_ares (unsigned char *haystack, int packet_len, int head_len)
{
//	const unsigned char *t = haystack + head_len;
	
	/* all ares packets start with  */
	if (payload[1] == 0 && (plen - payload[0]) == 3)
	{
		switch (payload[2])
		{
			case 0x5a:
				/* ares connect */
				if ( plen == 6 && payload[5] == 0x05 ) return ((IPP2P_ARES * 100) + 1);
				break;
			case 0x09:
				/* ares search, min 3 chars --> 14 bytes
				 * lets define a search can be up to 30 chars --> max 34 bytes
				 */
				if ( plen >= 14 && plen <= 34 ) return ((IPP2P_ARES * 100) + 1);
				break;
#ifdef IPP2P_DEBUG_ARES
			default:
			printk(KERN_DEBUG "Unknown Ares command %x recognized, len: %u \n", (unsigned int) payload[2],plen);
#endif /* IPP2P_DEBUG_ARES */
		}
	}

#if 0	        
	/* found connect packet: 03 00 5a 04 03 05 */
	/* new version ares 1.8: 03 00 5a xx xx 05 */
    if ((plen) == 6){	/* possible connect command*/
	if ((payload[0] == 0x03) && (payload[1] == 0x00) && (payload[2] == 0x5a) && (payload[5] == 0x05))
	    return ((IPP2P_ARES * 100) + 1);
    }
    if ((plen) == 60){	/* possible download command*/
	if ((payload[59] == 0x0a) && (payload[58] == 0x0a)){
	    if (memcmp(t, "PUSH SHA1:", 10) == 0) /* found download command */
	    	return ((IPP2P_ARES * 100) + 2);
	}
    }
#endif

    return 0;
} /*search_ares*/

/*Search for SoulSeek commands*/
int
search_soul (const unsigned char *payload, const u16 plen)
{
//#define IPP2P_DEBUG_SOUL
    /* match: xx xx xx xx | xx = sizeof(payload) - 4 */
    if (get_u32(payload, 0) == (plen - 4)){
	const __u32 m=get_u32(payload, 4);
	/* match 00 yy yy 00, yy can be everything */
        if ( get_u8(payload, 4) == 0x00 && get_u8(payload, 7) == 0x00 )
	{
#ifdef IPP2P_DEBUG_SOUL
	printk(KERN_DEBUG "0: Soulseek command 0x%x recognized\n",get_u32(payload, 4));
#endif /* IPP2P_DEBUG_SOUL */
		return ((IPP2P_SOUL * 100) + 1);
	}
	
        /* next match: 01 yy 00 00 | yy can be everything */
        if ( get_u8(payload, 4) == 0x01 && get_u16(payload, 6) == 0x0000 )
	{
#ifdef IPP2P_DEBUG_SOUL
	printk(KERN_DEBUG "1: Soulseek command 0x%x recognized\n",get_u16(payload, 4));
#endif /* IPP2P_DEBUG_SOUL */
		return ((IPP2P_SOUL * 100) + 2);
	}
	
	/* other soulseek commandos are: 1-5,7,9,13-18,22,23,26,28,35-37,40-46,50,51,60,62-69,91,92,1001 */
	/* try to do this in an intelligent way */
	/* get all small commandos */
	switch(m)
	{
		case 7:
		case 9:
		case 22:
		case 23:
		case 26:
		case 28:
		case 50:
		case 51:
		case 60:
		case 91:
		case 92:
		case 1001:
#ifdef IPP2P_DEBUG_SOUL
		printk(KERN_DEBUG "2: Soulseek command 0x%x recognized\n",get_u16(payload, 4));
#endif /* IPP2P_DEBUG_SOUL */
		return ((IPP2P_SOUL * 100) + 3);
	}
	
	if (m > 0 && m < 6 ) 
	{
#ifdef IPP2P_DEBUG_SOUL
		printk(KERN_DEBUG "3: Soulseek command 0x%x recognized\n",get_u16(payload, 4));
#endif /* IPP2P_DEBUG_SOUL */
		return ((IPP2P_SOUL * 100) + 4);
	}
	if (m > 12 && m < 19 )
	{
#ifdef IPP2P_DEBUG_SOUL
		printk(KERN_DEBUG "4: Soulseek command 0x%x recognized\n",get_u16(payload, 4));
#endif /* IPP2P_DEBUG_SOUL */
		return ((IPP2P_SOUL * 100) + 5);
	}

	if (m > 34 && m < 38 )
	{
#ifdef IPP2P_DEBUG_SOUL
		printk(KERN_DEBUG "5: Soulseek command 0x%x recognized\n",get_u16(payload, 4));
#endif /* IPP2P_DEBUG_SOUL */
		return ((IPP2P_SOUL * 100) + 6);
	}

	if (m > 39 && m < 47 )
	{
#ifdef IPP2P_DEBUG_SOUL
		printk(KERN_DEBUG "6: Soulseek command 0x%x recognized\n",get_u16(payload, 4));
#endif /* IPP2P_DEBUG_SOUL */
		return ((IPP2P_SOUL * 100) + 7);
	}

	if (m > 61 && m < 70 ) 
	{
#ifdef IPP2P_DEBUG_SOUL
		printk(KERN_DEBUG "7: Soulseek command 0x%x recognized\n",get_u16(payload, 4));
#endif /* IPP2P_DEBUG_SOUL */
		return ((IPP2P_SOUL * 100) + 8);
	}

#ifdef IPP2P_DEBUG_SOUL
	printk(KERN_DEBUG "unknown SOULSEEK command: 0x%x, first 16 bit: 0x%x, first 8 bit: 0x%x ,soulseek ???\n",get_u32(payload, 4),get_u16(payload, 4) >> 16,get_u8(payload, 4) >> 24);
#endif /* IPP2P_DEBUG_SOUL */
    }
	
	/* match 14 00 00 00 01 yy 00 00 00 STRING(YY) 01 00 00 00 00 46|50 00 00 00 00 */
	/* without size at the beginning !!! */
	if ( get_u32(payload, 0) == 0x14 && get_u8(payload, 4) == 0x01 )
	{
		__u32 y=get_u32(payload, 5);
		/* we need 19 chars + string */
		if ( (y + 19) <= (plen) )
		{
			const unsigned char *w=payload+9+y;
			if (get_u32(w, 0) == 0x01 && ( get_u16(w, 4) == 0x4600 || get_u16(w, 4) == 0x5000) && get_u32(w, 6) == 0x00);
#ifdef IPP2P_DEBUG_SOUL
	    		printk(KERN_DEBUG "Soulssek special client command recognized\n");
#endif /* IPP2P_DEBUG_SOUL */
	    		return ((IPP2P_SOUL * 100) + 9);
		}
	}
    return 0;
}


/*Search for WinMX commands*/
int
search_winmx (const unsigned char *payload, const u16 plen)
{
//#define IPP2P_DEBUG_WINMX
    if (((plen) == 4) && (memcmp(payload, "SEND", 4) == 0))  return ((IPP2P_WINMX * 100) + 1);
    if (((plen) == 3) && (memcmp(payload, "GET", 3) == 0))  return ((IPP2P_WINMX * 100) + 2);
    //if (packet_len < (head_len + 10)) return 0;
    if (plen < 10) return 0;
    
    if ((memcmp(payload, "SEND", 4) == 0) || (memcmp(payload, "GET", 3) == 0)){
        u16 c=4;
        const u16 end=plen-2;
        u8 count=0;
        while (c < end)
        {
        	if (payload[c]== 0x20 && payload[c+1] == 0x22)
        	{
        		c++;
        		count++;
        		if (count>=2) return ((IPP2P_WINMX * 100) + 3);
        	}
        	c++;
        }
    }
    
    if ( plen == 149 && payload[0] == '8' )
    {
#ifdef IPP2P_DEBUG_WINMX
    	printk(KERN_INFO "maybe WinMX\n");
#endif
    	if (get_u32(payload,17) == 0 && get_u32(payload,21) == 0 && get_u32(payload,25) == 0 &&
//    	    get_u32(payload,33) == __constant_htonl(0x71182b1a) && get_u32(payload,37) == __constant_htonl(0x05050000) &&
//    	    get_u32(payload,133) == __constant_htonl(0x31097edf) && get_u32(payload,145) == __constant_htonl(0xdcb8f792))
    	    get_u16(payload,39) == 0 && get_u16(payload,135) == __constant_htons(0x7edf) && get_u16(payload,147) == __constant_htons(0xf792))
    	    
    	{
#ifdef IPP2P_DEBUG_WINMX
    		printk(KERN_INFO "got WinMX\n");
#endif
    		return ((IPP2P_WINMX * 100) + 4);
    	}
    }
    return 0;
} /*search_winmx*/