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_vdolive_out (struct ip_masq_app *mapp, struct ip_masq *ms, struct sk_buff **skb_p, struct device *dev)
{
        struct sk_buff *skb;
	struct iphdr *iph;
	struct tcphdr *th;
	char *data, *data_limit;
	unsigned int tagval;	/* This should be a 32 bit quantity */
	struct ip_masq *n_ms;
	struct vdolive_priv_data *priv = 
		(struct vdolive_priv_data *)ms->app_data;

	/* This doesn't work at all if no priv data was allocated on startup */
	if (!priv)
		return 0;

	/* Everything running correctly already */
	if (priv->state == 3)
		return 0;

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

        data_limit = skb->h.raw + skb->len;

	if (data+8 > data_limit) {
#if DEBUG_CONFIG_IP_MASQ_VDOLIVE
		printk("VDOlive: packet too short for ID %lx %lx\n",
		       data, data_limit);
#endif
		return 0;
	}
	memcpy(&tagval, data+4, 4);
#if DEBUG_CONFIG_IP_MASQ_VDOLIVE
	printk("VDOlive: packet seen, tag %ld, in initial state %d\n",
	       ntohl(tagval), priv->state);
#endif

	/* Check for leading packet ID */
	if ((ntohl(tagval) != 6) && (ntohl(tagval) != 1)) {
#if DEBUG_CONFIG_IP_MASQ_VDOLIVE
		printk("VDOlive: unrecognised tag %ld, in initial state %d\n",
		       ntohl(tagval), priv->state);
#endif
		return 0;
	}
		

	/* Check packet is long enough for data - ignore if not */
	if ((ntohl(tagval) == 6) && (data+36 > data_limit)) {
#if DEBUG_CONFIG_IP_MASQ_VDOLIVE
		printk("VDOlive: initial packet too short %lx %lx\n",
		       data, data_limit);
#endif
		return 0;
	} else if ((ntohl(tagval) == 1) && (data+20 > data_limit)) {
#if DEBUG_CONFIG_IP_MASQ_VDOLIVE
		printk("VDOlive: secondary packet too short %lx %lx\n",
		       data, data_limit);
#endif
		return 0;
	}

	/* Adjust data pointers */
	/*
	 * I could check the complete protocol version tag 
	 * in here however I am just going to look for the
	 * "VDO Live" tag in the hope that this part will
	 * remain constant even if the version changes
	 */
	if (ntohl(tagval) == 6) {
		data += 24;
#if DEBUG_CONFIG_IP_MASQ_VDOLIVE
		printk("VDOlive: initial packet found\n");
#endif
	} else {
		data += 8;
#if DEBUG_CONFIG_IP_MASQ_VDOLIVE
		printk("VDOlive: secondary packet found\n");
#endif
	}

	if (memcmp(data, "VDO Live", 8) != 0) {
#if DEBUG_CONFIG_IP_MASQ_VDOLIVE
		printk("VDOlive: did not find tag\n");
#endif
		return 0;
	}
	/* 
	 * The port number is the next word after the tag.
	 * VDOlive encodes all of these values
	 * in 32 bit words, so in this case I am
	 * skipping the first 2 bytes of the next
	 * word to get to the relevant 16 bits
	 */
	data += 10;

	/*
	 * If we have not seen the port already,
	 * set the masquerading tunnel up
	 */
	if (!priv->origport) {
		memcpy(&priv->origport, data, 2);

#if DEBUG_CONFIG_IP_MASQ_VDOLIVE
		printk("VDOlive: found port %d\n",
		       ntohs(priv->origport));
#endif

		/* Open up a tunnel */
		n_ms = ip_masq_new(dev, IPPROTO_UDP,
				   ms->saddr, priv->origport,
				   ms->daddr, 0,
				   IP_MASQ_F_NO_DPORT);
					
		if (n_ms==NULL) {
			printk("VDOlive: unable to build UDP tunnel for %x:%x\n",
			       ms->saddr, priv->origport);
			/* Leave state as unset */
			priv->origport = 0;
			return 0;
		}

		ip_masq_set_expire(n_ms, ip_masq_expire->udp_timeout);
		priv->masqport = n_ms->mport;
	} else if (memcmp(data, &(priv->origport), 2)) {
		printk("VDOlive: ports do not match\n");
		/* Write the port in anyhow!!! */
	}

	/*
	 * Write masq port into packet
	 */
	memcpy(data, &(priv->masqport), 2);
#if DEBUG_CONFIG_IP_MASQ_VDOLIVE
	printk("VDOlive: rewrote port %d to %d, server %s\n",
	       ntohs(priv->origport), ntohs(priv->masqport), in_ntoa(ms->saddr));
#endif

	/*
	 * Set state bit to make which bit has been done
	 */

	priv->state |= (ntohl(tagval) == 6) ? 1 : 2;

	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, struct device *dev)
{
        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;
        int xtra_args = 0;      /* extra int args wanted after addr */
        char *dcc_p, *addr_beg_p, *addr_end_p;

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

        /*
         *	Hunt irc DCC string, the _shortest_:
         *
         *	strlen("DCC CHAT chat AAAAAAAA P\x01\n")=26
         *	strlen("DCC SEND F AAAAAAAA P S\x01\n")=25
         *		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 - 25) )
	{
		if (memcmp(data,"DCC ",4))  {
			data ++;
			continue;
		}
                
                dcc_p = data;
		data += 4;     /* point to DCC cmd */
                
                if (memcmp(data, "CHAT ", 5) == 0 ||
                    memcmp(data, "SEND ", 5) == 0)
                {
                        /*
                         *	extra arg (file_size) req. for "SEND"
                         */
                        
                        if (*data == 'S') xtra_args++;
                        data += 5;
                }
                else
                        continue;

                /*
                 *	skip next string.
                 */
                
                while( *data++ != ' ')
                        
                        /*
                         *	must still parse, at least, "AAAAAAAA P\x01\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;
                
                /*
                 *	should check args consistency?
                 */
                
                while(xtra_args) {
                        if (*data != ' ')
                                break;
                        data++;
                        simple_strtoul(data,&data,10);
                        xtra_args--;
                }
                
                if (xtra_args != 0) continue;
                
                /*
                 *	terminators.
                 */
                
                if (data[0] != 0x01)
                        continue;
		if (data[1]!='\r' && data[1]!='\n')
			continue;
                
		/*
		 *	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(dev, IPPROTO_TCP,
                                   htonl(s_addr),htons(s_port),
                                   0, 0,
                                   IP_MASQ_F_NO_DPORT|IP_MASQ_F_NO_DADDR
                                   );
		if (n_ms==NULL)
			return 0;

                ip_masq_set_expire(n_ms, ip_masq_expire->tcp_fin_timeout);
                
		/*
		 * 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);

#if DEBUG_CONFIG_IP_MASQ_IRC
                *addr_beg_p = '\0';
		printk("masq_irc_out(): '%s' %X:%X detected (diff=%d)\n", dcc_p, s_addr,s_port, diff);
#endif	
		/*
		 *	No shift.
		 */
		 
		if (diff==0) 
		{
			/*
			 * simple case, just copy.
 			 */
 			memcpy(addr_beg_p,buf,buf_len);
 			return 0;
 		}

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

}
Exemplo n.º 4
0
int ip_fw_masq_icmp(struct sk_buff **skb_p, struct device *dev)
{
        struct sk_buff 	*skb   = *skb_p;
 	struct iphdr	*iph   = skb->h.iph;
	struct icmphdr  *icmph = (struct icmphdr *)((char *)iph + (iph->ihl<<2));
	struct iphdr    *ciph;	/* The ip header contained within the ICMP */
	__u16	        *pptr;	/* port numbers from TCP/UDP contained header */
	struct ip_masq	*ms;
	unsigned short   len   = ntohs(iph->tot_len) - (iph->ihl * 4);

#ifdef DEBUG_CONFIG_IP_MASQUERADE_ICMP
 	printk("Incoming forward ICMP (%d,%d) %lX -> %lX\n",
	        icmph->type, ntohs(icmp_id(icmph)),
 		ntohl(iph->saddr), ntohl(iph->daddr));
#endif

#ifdef CONFIG_IP_MASQUERADE_ICMP		
	if ((icmph->type == ICMP_ECHO ) ||
	    (icmph->type == ICMP_TIMESTAMP ) ||
	    (icmph->type == ICMP_INFO_REQUEST ) ||
	    (icmph->type == ICMP_ADDRESS )) {
#ifdef DEBUG_CONFIG_IP_MASQUERADE_ICMP
		printk("MASQ: icmp request rcv %lX->%lX id %d type %d\n",
		       ntohl(iph->saddr),
		       ntohl(iph->daddr),
		       ntohs(icmp_id(icmph)),
		       icmph->type);
#endif
		ms = ip_masq_out_get_2(iph->protocol,
				       iph->saddr,
				       icmp_id(icmph),
				       iph->daddr,
				       icmp_hv_req(icmph));
		if (ms == NULL) {
			ms = ip_masq_new(dev,
					 iph->protocol,
					 iph->saddr,
					 icmp_id(icmph),
					 iph->daddr,
					 icmp_hv_req(icmph),
					 0);
			if (ms == NULL)
				return (-1);
#ifdef DEBUG_CONFIG_IP_MASQUERADE_ICMP
			printk("MASQ: Create new icmp entry\n");
#endif	              
		}
		ip_masq_set_expire(ms, 0);
		/* Rewrite source address */
                
                /*
                 *	If sysctl !=0 and no pkt has been received yet
                 *	in this tunnel and routing iface address has changed...
                 *	 "You are welcome, diald".
                 */
                if ( sysctl_ip_dynaddr && ms->flags & IP_MASQ_F_NO_REPLY && dev->pa_addr != ms->maddr) {
                        unsigned long flags;
#ifdef DEBUG_CONFIG_IP_MASQUERADE
                        printk(KERN_INFO "ip_fw_masq_icmp(): change masq.addr %s",
                               in_ntoa(ms->maddr));
                        printk("-> %s\n", in_ntoa(dev->pa_addr));
#endif
                        save_flags(flags);
                        cli();
                        ip_masq_unhash(ms);
                        ms->maddr = dev->pa_addr;
                        ip_masq_hash(ms);
                        restore_flags(flags);
                }
                
		iph->saddr = ms->maddr;
		ip_send_check(iph);
		/* Rewrite port (id) */
		(icmph->un).echo.id = ms->mport;
		icmph->checksum = 0;
		icmph->checksum = ip_compute_csum((unsigned char *)icmph, len);
		ip_masq_set_expire(ms, MASQUERADE_EXPIRE_ICMP);
#ifdef DEBUG_CONFIG_IP_MASQUERADE_ICMP
		printk("MASQ: icmp request rwt %lX->%lX id %d type %d\n",
		       ntohl(iph->saddr),
		       ntohl(iph->daddr),
		       ntohs(icmp_id(icmph)),
		       icmph->type);
#endif
		return (1);
	}
#endif

	/* 
	 * Work through seeing if this is for us.
	 * These checks are supposed to be in an order that
	 * means easy things are checked first to speed up
	 * processing.... however this means that some
	 * packets will manage to get a long way down this
	 * stack and then be rejected, but thats life
	 */
	if ((icmph->type != ICMP_DEST_UNREACH) &&
	    (icmph->type != ICMP_SOURCE_QUENCH) &&
	    (icmph->type != ICMP_TIME_EXCEEDED))
		return 0;

	/* Now find the contained IP header */
	ciph = (struct iphdr *) (icmph + 1);

#ifdef CONFIG_IP_MASQUERADE_ICMP
	if (ciph->protocol == IPPROTO_ICMP) {
		/*
		 * This section handles ICMP errors for ICMP packets
		 */
		struct icmphdr  *cicmph = (struct icmphdr *)((char *)ciph + 
							     (ciph->ihl<<2));

#ifdef DEBUG_CONFIG_IP_MASQUERADE_ICMP
		printk("MASQ: fw icmp/icmp rcv %lX->%lX id %d type %d\n",
		       ntohl(ciph->saddr),
		       ntohl(ciph->daddr),
		       ntohs(icmp_id(cicmph)),
		       cicmph->type);
#endif
		ms = ip_masq_out_get_2(ciph->protocol, 
				      ciph->daddr,
				      icmp_id(cicmph),
				      ciph->saddr,
				      icmp_hv_rep(cicmph));

		if (ms == NULL)
			return 0;

		/* Now we do real damage to this packet...! */
		/* First change the source IP address, and recalc checksum */
		iph->saddr = ms->maddr;
		ip_send_check(iph);
	
		/* Now change the *dest* address in the contained IP */
		ciph->daddr = ms->maddr;
		ip_send_check(ciph);

		/* Change the ID to the masqed one! */
		(cicmph->un).echo.id = ms->mport;
	
		/* And finally the ICMP checksum */
		icmph->checksum = 0;
		icmph->checksum = ip_compute_csum((unsigned char *) icmph, len);

#ifdef DEBUG_CONFIG_IP_MASQUERADE_ICMP
		printk("MASQ: fw icmp/icmp rwt %lX->%lX id %d type %d\n",
		       ntohl(ciph->saddr),
		       ntohl(ciph->daddr),
		       ntohs(icmp_id(cicmph)),
		       cicmph->type);
#endif
		return 1;
	}
#endif /* CONFIG_IP_MASQUERADE_ICMP */

	/* We are only interested ICMPs generated from TCP or UDP packets */
	if ((ciph->protocol != IPPROTO_UDP) && (ciph->protocol != IPPROTO_TCP))
		return 0;

	/* 
	 * Find the ports involved - this packet was 
	 * incoming so the ports are right way round
	 * (but reversed relative to outer IP header!)
	 */
	pptr = (__u16 *)&(((char *)ciph)[ciph->ihl*4]);

	/* Ensure the checksum is correct */
	if (ip_compute_csum((unsigned char *) icmph, len)) 
	{
		/* Failed checksum! */
		printk(KERN_DEBUG "MASQ: forward ICMP: failed checksum from %s!\n", 
		       in_ntoa(iph->saddr));
		return(-1);
	}

#ifdef DEBUG_CONFIG_IP_MASQUERADE
	printk("Handling forward ICMP for %lX:%X -> %lX:%X\n",
	       ntohl(ciph->saddr), ntohs(pptr[0]),
	       ntohl(ciph->daddr), ntohs(pptr[1]));
#endif

	/* This is pretty much what ip_masq_out_get() does */
	ms = ip_masq_out_get_2(ciph->protocol, 
			       ciph->daddr, 
			       pptr[1], 
			       ciph->saddr, 
			       pptr[0]);

	if (ms == NULL)
		return 0;

	/* Now we do real damage to this packet...! */
	/* First change the source IP address, and recalc checksum */
	iph->saddr = ms->maddr;
	ip_send_check(iph);
	
	/* Now change the *dest* address in the contained IP */
	ciph->daddr = ms->maddr;
	ip_send_check(ciph);
	
	/* the TCP/UDP dest port - cannot redo check */
	pptr[1] = ms->mport;

	/* And finally the ICMP checksum */
	icmph->checksum = 0;
	icmph->checksum = ip_compute_csum((unsigned char *) icmph, len);

#ifdef DEBUG_CONFIG_IP_MASQUERADE
	printk("Rewrote forward ICMP to %lX:%X -> %lX:%X\n",
	       ntohl(ciph->saddr), ntohs(pptr[0]),
	       ntohl(ciph->daddr), ntohs(pptr[1]));
#endif

	return 1;
}
Exemplo n.º 5
0
int
masq_quake_out (struct ip_masq_app *mapp, struct ip_masq *ms, struct sk_buff **skb_p, struct device *dev)
{
	struct sk_buff *skb;
	struct iphdr *iph;
	struct udphdr *uh;
	QUAKEHEADER *qh;
	__u16 udp_port;
	char *data;
	unsigned char code;
	struct ip_masq *n_ms;
	struct quake_priv_data *priv = (struct quake_priv_data *)ms->app_data;

	if(priv->cl_connect == -1)
	  return 0;
        
	skb = *skb_p;
	iph = skb->h.iph;
/*	iph = skb->nh.iph; */

	uh = (struct udphdr *)&(((char *)iph)[iph->ihl*4]);

	/* Check for lenght */
	if(ntohs(uh->len) < 5)
	  return 0;
	
	qh = (QUAKEHEADER *)&uh[1];

#if DEBUG_CONFIG_IP_MASQ_QUAKE
	  printk("Quake_out: qh->type = %d \n", (int)qh->type);
#endif

	if(qh->type != 0x0080)
	  return 0;
	
	code = qh->message[0];

#if DEBUG_CONFIG_IP_MASQ_QUAKE
	  printk("Quake_out: code = %d \n", (int)code);
#endif

	switch(code) {
	case 0x01:
	  /* Connection Request */

	  if(ntohs(qh->length) < 0x0c) {
#if DEBUG_CONFIG_IP_MASQ_QUAKE
	    printk("Quake_out: length < 0xc \n");
#endif
	    return 0;
	  }

	  data = &qh->message[1];

	  /* Check for stomping string */
	  if(memcmp(data,"QUAKE\0\3",7)) {
#if DEBUG_CONFIG_IP_MASQ_QUAKE
	    printk("Quake_out: memcmp failed \n");
#endif
	    return 0;
	  }
	  else {
	    priv->cl_connect = 1;
#if DEBUG_CONFIG_IP_MASQ_QUAKE
	    printk("Quake_out: memcmp ok \n");
#endif
	  }
	  break;

	case 0x81:
	  /* Maybe a redirection of a quake-server at the inner side works in
             the future? */

	  /* Accept Connection */
	  if((ntohs(qh->length) < 0x09) || (priv->cl_connect == 0))
	    return 0;

	  data = &qh->message[1];

	  memcpy(&udp_port, data, 2);
	  
	  n_ms = ip_masq_new(dev, IPPROTO_UDP,
			     ms->saddr, htons(udp_port),
			     ms->daddr, ms->dport,
			     0);

	  if (n_ms==NULL)
	    return 0;

#if DEBUG_CONFIG_IP_MASQ_QUAKE
	  printk("Quake_out: out_rewrote UDP port %d -> %d\n",
		 udp_port, ntohs(n_ms->mport));
#endif
	  udp_port = ntohs(n_ms->mport);
	  memcpy(data, &udp_port, 2);

	  break;
	}
	 
	return 0;
}
Exemplo n.º 6
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 7
0
int
masq_ftp_in (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;
	unsigned char p1,p2,p3,p4,p5,p6;
	__u32 to;
	__u16 port;
	struct ip_masq *n_ms;

	if (ms->app_data != &masq_ftp_pasv)
		return 0;	/* quick exit if no outstanding PASV */

	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;

	while (data < data_limit && *data != ' ')
		++data;	
	while (data < data_limit && *data == ' ')
		++data;	
	data += 22;
	if (data >= data_limit || *data != '(')
		return 0;
	p1 = simple_strtoul(data+1, &data, 10);
	if (data >= data_limit || *data != ',')
		return 0;
	p2 = simple_strtoul(data+1, &data, 10);
	if (data >= data_limit || *data != ',')
		return 0;
	p3 = simple_strtoul(data+1, &data, 10);
	if (data >= data_limit || *data != ',')
		return 0;
	p4 = simple_strtoul(data+1, &data, 10);
	if (data >= data_limit || *data != ',')
		return 0;
	p5 = simple_strtoul(data+1, &data, 10);
	if (data >= data_limit || *data != ',')
		return 0;
	p6 = simple_strtoul(data+1, &data, 10);
	if (data >= data_limit || *data != ')')
		return 0;

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

	/*
	 * Now update or create an masquerade entry for it
	 */
	IP_MASQ_DEBUG(1-debug, "PASV response %lX:%X %X:%X detected\n", ntohl(ms->saddr), 0, to, port);

	n_ms = ip_masq_out_get(iph->protocol,
				 ms->saddr, 0,
				 htonl(to), htons(port));
	if (!n_ms) {
		n_ms = ip_masq_new(IPPROTO_TCP,
					maddr, 0,
					ms->saddr, 0,
					htonl(to), htons(port),
					IP_MASQ_F_NO_SPORT);

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

#if 0	/* v0.12 state processing */

	/*
	 * keep for a bit longer than tcp_fin, client may not issue open
	 * to server port before tcp_fin_timeout.
	 */
	n_ms->timeout = ip_masq_expire->tcp_fin_timeout*3;
#endif
	ms->app_data = NULL;
	ip_masq_put(n_ms);

	return 0;	/* no diff required for incoming packets, thank goodness */
}
Exemplo n.º 8
0
int
masq_ftp_out (struct ip_masq_app *mapp, struct ip_masq *ms, struct sk_buff **skb_p, struct device *dev)
{
        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->h.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->flags |= IP_MASQ_F_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;
#if DEBUG_CONFIG_IP_MASQ_FTP
		printk("PORT %X:%X detected\n",from,port);
#endif	
		/*
		 * Now update or create an masquerade entry for it
		 */
#if DEBUG_CONFIG_IP_MASQ_FTP
		printk("protocol %d %lX:%X %X:%X\n", iph->protocol, htonl(from), htons(port), iph->daddr, 0);

#endif	
		n_ms = ip_masq_out_get_2(iph->protocol,
					 htonl(from), htons(port),
					 iph->daddr, 0);
		if (n_ms) {
			/* existing masquerade, clear timer */
			ip_masq_set_expire(n_ms,0);
		}
		else {
			n_ms = ip_masq_new(dev, IPPROTO_TCP,
					   htonl(from), htons(port),
					   iph->daddr, 0,
					   IP_MASQ_F_NO_DPORT);
					
			if (n_ms==NULL)
				return 0;
			n_ms->control = ms;		/* keepalive from data to the control channel */
			ms->flags |= IP_MASQ_F_CONTROL;	/* this is a control channel */
		}

                /*
                 * keep for a bit longer than tcp_fin, caller may not reissue
                 * PORT before tcp_fin_timeout.
                 */
                ip_masq_set_expire(n_ms, ip_masq_expire->tcp_fin_timeout*3);

		/*
		 * 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);
#if DEBUG_CONFIG_IP_MASQ_FTP
		printk("new PORT %X:%X\n",from,port);
#endif	

		/*
		 * 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);
 			return 0;
 		}

                *skb_p = ip_masq_skb_replace(skb, GFP_ATOMIC, p, data-p, buf, buf_len);
                return diff;

	}
	return 0;

}
Exemplo n.º 9
0
int
masq_ftp_in (struct ip_masq_app *mapp, struct ip_masq *ms, struct sk_buff **skb_p, struct device *dev)
{
	struct sk_buff *skb;
	struct iphdr *iph;
	struct tcphdr *th;
	char *data, *data_limit;
	unsigned char p1,p2,p3,p4,p5,p6;
	__u32 to;
	__u16 port;
	struct ip_masq *n_ms;

	if (! ms->flags & IP_MASQ_F_FTP_PASV)
		return 0;	/* quick exit if no outstanding PASV */

	skb = *skb_p;
	iph = skb->h.iph;
	th = (struct tcphdr *)&(((char *)iph)[iph->ihl*4]);
	data = (char *)&th[1];
	data_limit = skb->h.raw + skb->len;

	while (data < data_limit && *data != ' ')
		++data;	
	while (data < data_limit && *data == ' ')
		++data;	
	data += 22;
	if (data >= data_limit || *data != '(')
		return 0;
	p1 = simple_strtoul(data+1, &data, 10);
	if (data >= data_limit || *data != ',')
		return 0;
	p2 = simple_strtoul(data+1, &data, 10);
	if (data >= data_limit || *data != ',')
		return 0;
	p3 = simple_strtoul(data+1, &data, 10);
	if (data >= data_limit || *data != ',')
		return 0;
	p4 = simple_strtoul(data+1, &data, 10);
	if (data >= data_limit || *data != ',')
		return 0;
	p5 = simple_strtoul(data+1, &data, 10);
	if (data >= data_limit || *data != ',')
		return 0;
	p6 = simple_strtoul(data+1, &data, 10);
	if (data >= data_limit || *data != ')')
		return 0;

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

	/*
	 * Now update or create an masquerade entry for it
	 */
#if DEBUG_CONFIG_IP_MASQ_FTP
	printk("PASV response %lX:%X %X:%X detected\n", ntohl(ms->saddr), 0, to, port);
#endif	
	n_ms = ip_masq_out_get_2(iph->protocol,
				 ms->saddr, 0,
				 htonl(to), htons(port));
	if (n_ms) {
		/* existing masquerade, clear timer */
		ip_masq_set_expire(n_ms,0);
	}
	else {
		n_ms = ip_masq_new(dev, IPPROTO_TCP,
				   ms->saddr, 0,
				   htonl(to), htons(port),
				   IP_MASQ_F_NO_SPORT);

		if (n_ms==NULL)
			return 0;
		n_ms->control = ms;		/* keepalive from data to the control channel */
		ms->flags |= IP_MASQ_F_CONTROL;	/* this is a control channel */
	}

	/*
	 * keep for a bit longer than tcp_fin, client may not issue open
	 * to server port before tcp_fin_timeout.
	 */
	ip_masq_set_expire(n_ms, ip_masq_expire->tcp_fin_timeout*3);
	ms->flags &= ~IP_MASQ_F_FTP_PASV;
	return 0;	/* no diff required for incoming packets, thank goodness */
}
Exemplo n.º 10
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;

}