Exemplo n.º 1
0
/*
 *	Create new entry (from uspace)
 */
static int ip_masq_user_new(struct ip_masq_user *ums)
{
	struct ip_masq *ms = NULL;
	unsigned mflags = 0;
	int ret;

	if (masq_proto_num (ums->protocol) == -1) {
		return EPROTONOSUPPORT;
	}

	if (ums->dport == 0) {
		ums->flags |= IP_MASQ_USER_F_LISTEN;
	}

	if (ums->flags | IP_MASQ_USER_F_LISTEN) {
		if ((ums->saddr == 0) || (ums->sport == 0)) {
			return EINVAL;
		}
		mflags |= (IP_MASQ_F_NO_DPORT|IP_MASQ_F_NO_DADDR);

	}

	if ((ret = ip_masq_user_maddr(ums)) < 0) {
		return -ret;
	}

	mflags |= IP_MASQ_F_USER;
	ms = ip_masq_new(ums->protocol, 
			ums->maddr, ums->mport, 
			ums->saddr, ums->sport,
			ums->daddr, ums->dport,
			mflags);
	
	if (ms == NULL) {
		/*
		 *	FIXME: ip_masq_new() should return errno
		 */
		return EBUSY;
	}

	/*
	 *	Setup timeouts for this new entry
	 */

	if (ums->timeout) {
		ms->timeout = ums->timeout;
	} else if (ums->flags | IP_MASQ_USER_F_LISTEN) {
		ip_masq_listen(ms);
	}

	masq_user_k2u(ms, ums);
	ip_masq_put(ms);
	return 0;
}
Exemplo n.º 2
0
int
masq_ftp_out (struct ip_masq_app *mapp, struct ip_masq *ms, struct sk_buff **skb_p, __u32 maddr)
{
        struct sk_buff *skb;
	struct iphdr *iph;
	struct tcphdr *th;
	char *p, *data, *data_limit;
	unsigned char p1,p2,p3,p4,p5,p6;
	__u32 from;
	__u16 port;
	struct ip_masq *n_ms;
	char buf[24];		/* xxx.xxx.xxx.xxx,ppp,ppp\000 */
        unsigned buf_len;
	int diff;

        skb = *skb_p;
	iph = skb->nh.iph;
        th = (struct tcphdr *)&(((char *)iph)[iph->ihl*4]);
        data = (char *)&th[1];

        data_limit = skb->h.raw + skb->len - 18;
        if (skb->len >= 6 && (memcmp(data, "PASV\r\n", 6) == 0 || memcmp(data, "pasv\r\n", 6) == 0))
		ms->app_data = &masq_ftp_pasv;

	while (data < data_limit)
	{
		if (memcmp(data,"PORT ",5) && memcmp(data,"port ",5))
		{
			data ++;
			continue;
		}
		p = data+5;
 		p1 = simple_strtoul(data+5,&data,10);
		if (*data!=',')
			continue;
		p2 = simple_strtoul(data+1,&data,10);
		if (*data!=',')
			continue;
		p3 = simple_strtoul(data+1,&data,10);
		if (*data!=',')
			continue;
		p4 = simple_strtoul(data+1,&data,10);
		if (*data!=',')
			continue;
		p5 = simple_strtoul(data+1,&data,10);
		if (*data!=',')
			continue;
		p6 = simple_strtoul(data+1,&data,10);
		if (*data!='\r' && *data!='\n')
			continue;

		from = (p1<<24) | (p2<<16) | (p3<<8) | p4;
		port = (p5<<8) | p6;

		IP_MASQ_DEBUG(1-debug, "PORT %X:%X detected\n",from,port);

		/*
		 * Now update or create an masquerade entry for it
		 */

		IP_MASQ_DEBUG(1-debug, "protocol %d %lX:%X %X:%X\n", iph->protocol, htonl(from), htons(port), iph->daddr, 0);

		n_ms = ip_masq_out_get(iph->protocol,
					 htonl(from), htons(port),
					 iph->daddr, 0);
		if (!n_ms) {
			n_ms = ip_masq_new(IPPROTO_TCP,
					   maddr, 0,
					   htonl(from), htons(port),
					   iph->daddr, 0,
					   IP_MASQ_F_NO_DPORT);

			if (n_ms==NULL)
				return 0;
			ip_masq_control_add(n_ms, ms);
		}

		/*
		 * Replace the old PORT with the new one
		 */
		from = ntohl(n_ms->maddr);
		port = ntohs(n_ms->mport);
		sprintf(buf,"%d,%d,%d,%d,%d,%d",
			from>>24&255,from>>16&255,from>>8&255,from&255,
			port>>8&255,port&255);
		buf_len = strlen(buf);

		IP_MASQ_DEBUG(1-debug, "new PORT %X:%X\n",from,port);

		/*
		 * Calculate required delta-offset to keep TCP happy
		 */
		
		diff = buf_len - (data-p);
		
		/*
		 *	No shift.
		 */
		
		if (diff==0) {
			/*
			 * simple case, just replace the old PORT cmd
 			 */
 			memcpy(p,buf,buf_len);
 		} else {

			*skb_p = ip_masq_skb_replace(skb, GFP_ATOMIC, p, data-p, buf, buf_len);
		}
                /*
                 * 	Move tunnel to listen state
                 */
		ip_masq_listen(n_ms);
		ip_masq_put(n_ms);

                return diff;

	}
	return 0;

}
Exemplo n.º 3
0
int
masq_irc_out (struct ip_masq_app *mapp, struct ip_masq *ms, struct sk_buff **skb_p, __u32 maddr)
{
        struct sk_buff *skb;
	struct iphdr *iph;
	struct tcphdr *th;
	char *data, *data_limit;
	__u32 s_addr;
	__u16 s_port;
	struct ip_masq *n_ms;
	char buf[20];		/* "m_addr m_port" (dec base)*/
        unsigned buf_len;
	int diff;
        char *dcc_p, *addr_beg_p, *addr_end_p;

        skb = *skb_p;
	iph = skb->nh.iph;
        th = (struct tcphdr *)&(((char *)iph)[iph->ihl*4]);
        data = (char *)&th[1];

        /*
	 *	Hunt irc DCC string, the _shortest_:
	 *
	 *	strlen("\1DCC CHAT chat AAAAAAAA P\1\n")=27
	 *	strlen("\1DCC SCHAT chat AAAAAAAA P\1\n")=28
	 *	strlen("\1DCC SEND F AAAAAAAA P S\1\n")=26
	 *	strlen("\1DCC MOVE F AAAAAAAA P S\1\n")=26
	 *	strlen("\1DCC TSEND F AAAAAAAA P S\1\n")=27
	 *		AAAAAAAAA: bound addr (1.0.0.0==16777216, min 8 digits)
	 *		P:         bound port (min 1 d )
	 *		F:         filename   (min 1 d )
	 *		S:         size       (min 1 d ) 
	 *		0x01, \n:  terminators
         */

        data_limit = skb->h.raw + skb->len;
        
	while (data < (data_limit - ( 22 + MAXMATCHLEN ) ) )
	{
		int i;
		if (memcmp(data,"\1DCC ",5))  {
			data ++;
			continue;
		}

		dcc_p = data;
		data += 5;     /* point to DCC cmd */

		for(i=0; i<NUM_DCCPROTO; i++)
		{
			/*
			 * go through the table and hunt a match string
			 */

			if( memcmp(data, dccprotos[i].match, dccprotos[i].matchlen ) == 0 )
			{
				data += dccprotos[i].matchlen;

				/*
				 *	skip next string.
				 */

				while( *data++ != ' ')

					/*
					 *	must still parse, at least, "AAAAAAAA P\1\n",
					 *      12 bytes left.
					 */
					if (data > (data_limit-12)) return 0;


				addr_beg_p = data;

				/*
				 *	client bound address in dec base
				 */

				s_addr = simple_strtoul(data,&data,10);
				if (*data++ !=' ')
					continue;

				/*
				 *	client bound port in dec base
				 */

				s_port = simple_strtoul(data,&data,10);
				addr_end_p = data;

				/*
				 *	Now create an masquerade entry for it
				 * 	must set NO_DPORT and NO_DADDR because
				 *	connection is requested by another client.
				 */

				n_ms = ip_masq_new(IPPROTO_TCP,
						maddr, 0,
						htonl(s_addr),htons(s_port),
						0, 0,
						IP_MASQ_F_NO_DPORT|IP_MASQ_F_NO_DADDR);
				if (n_ms==NULL)
					return 0;

				/*
				 * Replace the old "address port" with the new one
				 */

				buf_len = sprintf(buf,"%lu %u",
						ntohl(n_ms->maddr),ntohs(n_ms->mport));

				/*
				 * Calculate required delta-offset to keep TCP happy
				 */

				diff = buf_len - (addr_end_p-addr_beg_p);

				*addr_beg_p = '\0';
				IP_MASQ_DEBUG(1-debug, "masq_irc_out(): '%s' %X:%X detected (diff=%d)\n", dcc_p, s_addr,s_port, diff);

				/*
				 *	No shift.
				 */

				if (diff==0) {
					/*
					 * simple case, just copy.
					 */
					memcpy(addr_beg_p,buf,buf_len);
				} else {

					*skb_p = ip_masq_skb_replace(skb, GFP_ATOMIC,
							addr_beg_p, addr_end_p-addr_beg_p,
							buf, buf_len);
				}
				ip_masq_listen(n_ms);
				ip_masq_put(n_ms);
				return diff;
			}
		}
	}
	return 0;

}