patch-2.3.15 linux/net/ipv4/ip_masq_raudio.c

• Lines: 579
• Date: Wed Dec 31 16:00:00 1969
• Orig file: v2.3.14/linux/net/ipv4/ip_masq_raudio.c
• Orig date: Tue Oct 27 09:57:19 1998

diff -u --recursive --new-file v2.3.14/linux/net/ipv4/ip_masq_raudio.c linux/net/ipv4/ip_masq_raudio.c
@@ -1,578 +0,0 @@
-/*
- *		IP_MASQ_RAUDIO  - Real Audio masquerading module
- *
- *
- * Version:	@(#)$Id: ip_masq_raudio.c,v 1.11 1998/10/06 04:49:04 davem Exp $
- *
- * Author:	Nigel Metheringham
- *		Real Time Streaming code by Progressive Networks
- *		[strongly based on ftp module by Juan Jose Ciarlante & Wouter Gadeyne]
- *		[Real Audio information taken from Progressive Networks firewall docs]
- *		[Kudos to Progressive Networks for making the protocol specs available]
- *
- *
- *
- *
- *	This program is free software; you can redistribute it and/or
- *	modify it under the terms of the GNU General Public License
- *	as published by the Free Software Foundation; either version
- *	2 of the License, or (at your option) any later version.
- *
- *
- * Limitations
- *	The IP Masquerading proxies at present do not have access to a processed
- *	data stream.  Hence for a protocol like the Real Audio control protocol,
- *	which depends on knowing where you are in the data stream, you either
- *	to keep a *lot* of state in your proxy, or you cheat and simplify the
- *	problem [needless to say I did the latter].
- *
- *	This proxy only handles data in the first packet.  Everything else is
- *	passed transparently.  This means it should work under all normal
- *	circumstances, but it could be fooled by new data formats or a
- *	malicious application!
- *
- *	At present the "first packet" is defined as a packet starting with
- *	the protocol ID string - "PNA".
- *	When the link is up there appears to be enough control data 
- *	crossing the control link to keep it open even if a long audio
- *	piece is playing.
- *
- *	The Robust UDP support added in RealAudio 3.0 is supported, but due
- *	to servers/clients not making great use of this has not been greatly
- *	tested.  RealVideo (as used in the Real client version 4.0beta1) is
- *	supported but again is not greatly tested (bandwidth requirements
- *	appear to exceed that available at the sites supporting the protocol).
- *
- * Multiple Port Support
- *	The helper can be made to handle up to MAX_MASQ_APP_PORTS (normally 12)
- *	with the port numbers being defined at module load time.  The module
- *	uses the symbol "ports" to define a list of monitored ports, which can
- *	be specified on the insmod command line as
- *		ports=x1,x2,x3...
- *	where x[n] are integer port numbers.  This option can be put into
- *	/etc/conf.modules (or /etc/modules.conf depending on your config)
- *	where modload will pick it up should you use modload to load your
- *	modules.
- *
- * Fixes:
- * 	Juan Jose Ciarlante	:	Use control_add() for control chan
- * 	10/15/97 - Modifications to allow masquerading of RTSP connections as
- *     		well as PNA, which can potentially exist on the same port.
- *		Joe Rumsey <ogre@real.com>
- *	
- */
-
-#include <linux/config.h>
-#include <linux/module.h>
-#include <asm/system.h>
-#include <linux/types.h>
-#include <linux/ctype.h>
-#include <linux/kernel.h>
-#include <linux/skbuff.h>
-#include <linux/in.h>
-#include <linux/ip.h>
-#include <linux/init.h>
-#include <net/protocol.h>
-#include <net/tcp.h>
-#include <net/ip_masq.h>
-
-/*
-#ifndef DEBUG_CONFIG_IP_MASQ_RAUDIO
-#define DEBUG_CONFIG_IP_MASQ_RAUDIO 0
-#endif
-*/
-
-#define TOLOWER(c) (((c) >= 'A' && (c) <= 'Z') ? ((c) - 'A' + 'a') : (c))
-#define ISDIGIT(c) (((c) >= '0') && ((c) <= '9'))
-
-struct raudio_priv_data {
-	/* Associated data connection - setup but not used at present */
-	struct	ip_masq *data_conn;
-	/* UDP Error correction connection - setup but not used at present */
-	struct	ip_masq *error_conn;
-	/* Have we seen and performed setup */
-	short	seen_start;
-        short   is_rtsp;
-};
-
-int
-masq_rtsp_out (struct ip_masq_app *mapp, 
-		 struct ip_masq *ms, 
-		 struct sk_buff **skb_p, 
-		 __u32 maddr);
-
-/* 
- * List of ports (up to MAX_MASQ_APP_PORTS) to be handled by helper
- * First port is set to the default port.
- */
-int ports[MAX_MASQ_APP_PORTS] = {554, 7070, 0}; /* I rely on the trailing items being set to zero */
-struct ip_masq_app *masq_incarnations[MAX_MASQ_APP_PORTS];
-
-/*
- *	Debug level
- */
-#ifdef CONFIG_IP_MASQ_DEBUG
-static int debug=0;
-MODULE_PARM(debug, "i");
-#endif
-
-MODULE_PARM(ports, "1-" __MODULE_STRING(MAX_MASQ_APP_PORTS) "i");
-
-
-static int
-masq_raudio_init_1 (struct ip_masq_app *mapp, struct ip_masq *ms)
-{
-        MOD_INC_USE_COUNT;
-	if ((ms->app_data = kmalloc(sizeof(struct raudio_priv_data),
-				    GFP_ATOMIC)) == NULL) 
-		printk(KERN_INFO "RealAudio: No memory for application data\n");
-	else 
-	{
-		struct raudio_priv_data *priv = 
-			(struct raudio_priv_data *)ms->app_data;
-		priv->seen_start = 0;
-		priv->data_conn = NULL;
-		priv->error_conn = NULL;
-		priv->is_rtsp = 0;
-	}
-        return 0;
-}
-
-static int
-masq_raudio_done_1 (struct ip_masq_app *mapp, struct ip_masq *ms)
-{
-        MOD_DEC_USE_COUNT;
-	if (ms->app_data)
-		kfree_s(ms->app_data, sizeof(struct raudio_priv_data));
-        return 0;
-}
-
-int
-masq_raudio_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;
-	struct ip_masq *n_ms;
-	unsigned short version, msg_id, msg_len, udp_port;
-	struct raudio_priv_data *priv = 
-		(struct raudio_priv_data *)ms->app_data;
-
-	/* Everything running correctly already */
-	if (priv && priv->seen_start)
-		return 0;
-
-	if(priv && priv->is_rtsp)
-	    return masq_rtsp_out(mapp, ms, skb_p, maddr);
-
-        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;
-
-	if(memcmp(data, "OPTIONS", 7) == 0 ||
-	   memcmp(data, "DESCRIBE", 8) == 0)
-	{
-	    IP_MASQ_DEBUG(1-debug, "RealAudio: Detected RTSP connection\n");
-	    /* This is an RTSP client */
-	    if(priv)
-		priv->is_rtsp = 1;
-	    return masq_rtsp_out(mapp, ms, skb_p, maddr);
-	}
-
-	/* Check to see if this is the first packet with protocol ID */
-	if (memcmp(data, "PNA", 3)) {
-		IP_MASQ_DEBUG(1-debug, "RealAudio: not initial protocol packet - ignored\n");
-		return(0);
-	}
-	data += 3;
-	memcpy(&version, data, 2);
-
-	IP_MASQ_DEBUG(1-debug, "RealAudio: initial seen - protocol version %d\n",
-	       ntohs(version));
-	if (priv)
-		priv->seen_start = 1;
-
-	if (ntohs(version) >= 256)
-	{
-		printk(KERN_INFO "RealAudio: version (%d) not supported\n",
-		       ntohs(version));
-		return 0;
-	}
-
-	data += 2;
-	while (data+4 < data_limit) {
-		memcpy(&msg_id, data, 2);
-		data += 2;
-		memcpy(&msg_len, data, 2);
-		data += 2;
-		if (ntohs(msg_id) == 0) {
-			/* The zero tag indicates the end of options */
-			IP_MASQ_DEBUG(1-debug, "RealAudio: packet end tag seen\n");
-			return 0;
-		}
-		IP_MASQ_DEBUG(1-debug, "RealAudio: msg %d - %d byte\n",
-		       ntohs(msg_id), ntohs(msg_len));
-		if (ntohs(msg_id) == 0) {
-			/* The zero tag indicates the end of options */
-			return 0;
-		}
-		p = data;
-		data += ntohs(msg_len);
-		if (data > data_limit)
-		{
-			printk(KERN_INFO "RealAudio: Packet too short for data\n");
-			return 0;
-		}
-		if ((ntohs(msg_id) == 1) || (ntohs(msg_id) == 7)) {
-			/* 
-			 * MsgId == 1
-			 * Audio UDP data port on client
-			 *
-			 * MsgId == 7
-			 * Robust UDP error correction port number on client
-			 *
-			 * Since these messages are treated just the same, they
-			 * are bundled together here....
-			 */
-			memcpy(&udp_port, p, 2);
-
-			/* 
-			 * Sometimes a server sends a message 7 with a zero UDP port
-			 * Rather than do anything with this, just ignore it!
-			 */
-			if (udp_port == 0)
-				continue;
-
-
-			n_ms = ip_masq_new(IPPROTO_UDP,
-						maddr, 0,
-						ms->saddr, udp_port,
-						ms->daddr, 0,
-						IP_MASQ_F_NO_DPORT);
-
-			if (n_ms==NULL)
-				return 0;
-
-			ip_masq_listen(n_ms);
-			ip_masq_control_add(n_ms, ms);
-
-			memcpy(p, &(n_ms->mport), 2);
-			IP_MASQ_DEBUG(1-debug, "RealAudio: rewrote UDP port %d -> %d in msg %d\n",
-			       ntohs(udp_port), ntohs(n_ms->mport), ntohs(msg_id));
-
-			/* Make ref in application data to data connection */
-			if (priv) {
-				if (ntohs(msg_id) == 1)
-					priv->data_conn = n_ms;
-				else
-					priv->error_conn = n_ms;
-			}
-			
-			ip_masq_put(n_ms);
-		}
-	}
-	return 0;
-}
-
-/*
- * masq_rtsp_out
- *
- * 
- */
-int
-masq_rtsp_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;
-	struct ip_masq *n_ms, *n_ms2;
-	unsigned short udp_port;
-	struct raudio_priv_data *priv = 
-		(struct raudio_priv_data *)ms->app_data;
-	const char* srch = "transport:";
-	const char* srchpos = srch;
-	const char* srchend = srch + strlen(srch);
-	int state = 0;
-	char firstport[6];
-	int firstportpos = 0;
-	char secondport[6];
-	int secondportpos = 0;
-	char *portstart = NULL, *portend = NULL;
-	int diff;
-
-	/* Everything running correctly already */
-	if (priv && priv->seen_start)
-		return 0;
-
-        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;
-
-	firstport[0] = 0;
-	secondport[0] = 0;
-
-	while(data < data_limit && state >= 0)
-	{
-	    switch(state)
-	    {
-		case 0:
-		case 1:
-		    if(TOLOWER(*data) == *srchpos)
-		    {
-			srchpos++;
-			if(srchpos == srchend)
-			{
-			    IP_MASQ_DEBUG(1-debug, "Found string %s in message\n",
-				   srch);
-			    state++;
-			    if(state == 1)
-			    {
-				srch = "client_port";
-				srchpos = srch;
-				srchend = srch + strlen(srch);
-			    }
-			}
-		    }
-		    else
-		    {
-			srchpos = srch;
-		    }
-		    break;
-		case 2:
-		    if(*data == '=')
-			state = 3;
-		    break;
-		case 3:
-		    if(ISDIGIT(*data))
-		    {
-			portstart = data;
-			firstportpos = 0;
-			firstport[firstportpos++] = *data;
-			state = 4;
-		    }
-		    break;
-		case 4:
-		    if(*data == '-')
-		    {
-			state = 5;
-		    }
-		    else if(*data == ';')
-		    {
-			portend = data - 1;
-			firstport[firstportpos] = 0;
-			state = -1;
-		    }
-		    else if(ISDIGIT(*data))
-		    {
-			firstport[firstportpos++] = *data;
-		    }
-		    else if(*data != ' ' && *data != '\t')
-		    {
-			/* This is a badly formed RTSP message, let's bail out */
-			IP_MASQ_DEBUG(1-debug, "Badly formed RTSP Message\n");
-			return 0;
-		    }
-		    break;
-		case 5:
-		    if(ISDIGIT(*data))
-		    {
-			secondportpos = 0;
-			secondport[secondportpos++] = *data;
-			state = 6;
-		    }
-		    else if(*data == ';')
-		    {
-			portend = data - 1;
-			secondport[secondportpos] = 0;
-			state = -1;
-		    }
-		    break;
-		case 6:
-		    if(*data == ';')
-		    {
-			portend = data - 1;
-			secondport[secondportpos] = 0;
-			state = -1;
-		    }
-		    else if(ISDIGIT(*data))
-		    {
-			secondport[secondportpos++] = *data;
-		    }
-		    else if(*data != ' ' && *data != '\t')
-		    {
-			/* This is a badly formed RTSP message, let's bail out */
-			IP_MASQ_DEBUG(1-debug, "Badly formed RTSP Message\n");
-			return 0;
-		    }
-		    break;
-	    }
-	    data++;
-	}
-
-	if(state >= 0)
-	    return 0;
-
-	if(firstportpos > 0)
-	{
-	    char newbuf[12]; /* xxxxx-xxxxx\0 */
-	    char* tmpptr;
-
-	    udp_port = htons(simple_strtoul(firstport, &tmpptr, 10));
-	    n_ms = ip_masq_new(IPPROTO_UDP,
-			       maddr, 0,
-			       ms->saddr, udp_port,
-			       ms->daddr, 0,
-			       IP_MASQ_F_NO_DPORT);
-	    if (n_ms==NULL)
-		return 0;
-	    
-	    ip_masq_listen(n_ms);
-	    ip_masq_control_add(n_ms, ms);
-
-	    if(secondportpos > 0)
-	    {
-		udp_port = htons(simple_strtoul(secondport, &tmpptr, 10));
-		n_ms2 = ip_masq_new(IPPROTO_UDP,
-				maddr, 0,
-				ms->saddr, udp_port,
-				ms->daddr, 0,
-				IP_MASQ_F_NO_DPORT);
-		if (n_ms2==NULL) {
-		    ip_masq_put(n_ms);
-		    return 0;
-		}
-
-		ip_masq_listen(n_ms2);
-		ip_masq_control_add(n_ms2, ms);
-		sprintf(newbuf, "%d-%d", ntohs(n_ms->mport), 
-			ntohs(n_ms2->mport));
-	    }
-	    else
-	    {
-		sprintf(newbuf, "%d", ntohs(n_ms->mport));
-		n_ms2 = NULL;
-	    }
-	    *skb_p = ip_masq_skb_replace(skb, GFP_ATOMIC,
-					 portstart, portend - portstart + 1,
-					 newbuf, strlen(newbuf));
-	    IP_MASQ_DEBUG(1-debug, "RTSP: rewrote client_port to %s\n", newbuf);
-	    diff = strlen(newbuf) - (portend - portstart);
-	}
-	else
-	{
-	    return 0;
-	}
-	    
-	if(priv)
-	{
-	    priv->seen_start = 1;
-	    if(n_ms)
-		priv->data_conn = n_ms;
-	    if(n_ms2)
-		priv->error_conn = n_ms2;
-	}
-	/*
-	 *	Release tunnels
-	 */
-
-	if (n_ms)
-		ip_masq_put(n_ms);
-
-	if (n_ms2)
-		ip_masq_put(n_ms2);
-
-	return diff;
-}
-
-struct ip_masq_app ip_masq_raudio = {
-        NULL,			/* next */
-	"RealAudio",	       	/* name */
-        0,                      /* type */
-        0,                      /* n_attach */
-        masq_raudio_init_1,     /* ip_masq_init_1 */
-        masq_raudio_done_1,     /* ip_masq_done_1 */
-        masq_raudio_out,        /* pkt_out */
-        NULL                    /* pkt_in */
-};
-
-/*
- * 	ip_masq_raudio initialization
- */
-
-__initfunc(int ip_masq_raudio_init(void))
-{
-	int i, j;
-
-	for (i=0; (i<MAX_MASQ_APP_PORTS); i++) {
-		if (ports[i]) {
-			if ((masq_incarnations[i] = kmalloc(sizeof(struct ip_masq_app),
-							    GFP_KERNEL)) == NULL)
-				return -ENOMEM;
-			memcpy(masq_incarnations[i], &ip_masq_raudio, sizeof(struct ip_masq_app));
-			if ((j = register_ip_masq_app(masq_incarnations[i], 
-						      IPPROTO_TCP, 
-						      ports[i]))) {
-				return j;
-			}
-			IP_MASQ_DEBUG(1-debug, "RealAudio: loaded support on port[%d] = %d\n",
-			       i, ports[i]);
-		} else {
-			/* To be safe, force the incarnation table entry to NULL */
-			masq_incarnations[i] = NULL;
-		}
-	}
-	return 0;
-}
-
-/*
- * 	ip_masq_raudio fin.
- */
-
-int ip_masq_raudio_done(void)
-{
-	int i, j, k;
-
-	k=0;
-	for (i=0; (i<MAX_MASQ_APP_PORTS); i++) {
-		if (masq_incarnations[i]) {
-			if ((j = unregister_ip_masq_app(masq_incarnations[i]))) {
-				k = j;
-			} else {
-				kfree(masq_incarnations[i]);
-				masq_incarnations[i] = NULL;
-				IP_MASQ_DEBUG(1-debug, "RealAudio: unloaded support on port[%d] = %d\n",
-				       i, ports[i]);
-			}
-		}
-	}
-	return k;
-}
-
-#ifdef MODULE
-EXPORT_NO_SYMBOLS;
-
-int init_module(void)
-{
-        if (ip_masq_raudio_init() != 0)
-                return -EIO;
-        return 0;
-}
-
-void cleanup_module(void)
-{
-        if (ip_masq_raudio_done() != 0)
-                printk(KERN_INFO "ip_masq_raudio: can't remove module");
-}
-
-#endif /* MODULE */