path: root/drivers/media/dvb-core/dvb_net.c

/*
 * dvb_net.c
 *
 * Copyright (C) 2001 Convergence integrated media GmbH
 *                    Ralph Metzler <ralph@convergence.de>
 * Copyright (C) 2002 Ralph Metzler <rjkm@metzlerbros.de>
 *
 * ULE Decapsulation code:
 * Copyright (C) 2003, 2004 gcs - Global Communication & Services GmbH.
 *                      and Department of Scientific Computing
 *                          Paris Lodron University of Salzburg.
 *                          Hilmar Linder <hlinder@cosy.sbg.ac.at>
 *                      and Wolfram Stering <wstering@cosy.sbg.ac.at>
 *
 * ULE Decaps according to RFC 4326.
 *
 * 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.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 * Or, point your browser to http://www.gnu.org/copyleft/gpl.html
 */

/*
 * ULE ChangeLog:
 * Feb 2004: hl/ws v1: Implementing draft-fair-ipdvb-ule-01.txt
 *
 * Dec 2004: hl/ws v2: Implementing draft-ietf-ipdvb-ule-03.txt:
 *                       ULE Extension header handling.
 *                     Bugreports by Moritz Vieth and Hanno Tersteegen,
 *                       Fraunhofer Institute for Open Communication Systems
 *                       Competence Center for Advanced Satellite Communications.
 *                     Bugfixes and robustness improvements.
 *                     Filtering on dest MAC addresses, if present (D-Bit = 0)
 *                     ULE_DEBUG compile-time option.
 * Apr 2006: cp v3:    Bugfixes and compliency with RFC 4326 (ULE) by
 *                       Christian Praehauser <cpraehaus@cosy.sbg.ac.at>,
 *                       Paris Lodron University of Salzburg.
 */

/*
 * FIXME / TODO (dvb_net.c):
 *
 * Unloading does not work for 2.6.9 kernels: a refcount doesn't go to zero.
 *
 */

#define pr_fmt(fmt) "dvb_net: " fmt

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/dvb/net.h>
#include <linux/uio.h>
#include <asm/uaccess.h>
#include <linux/crc32.h>
#include <linux/mutex.h>
#include <linux/sched.h>

#include "dvb_demux.h"
#include "dvb_net.h"

static inline __u32 iov_crc32( __u32 c, struct kvec *iov, unsigned int cnt )
{
	unsigned int j;
	for (j = 0; j < cnt; j++)
		c = crc32_be( c, iov[j].iov_base, iov[j].iov_len );
	return c;
}


#define DVB_NET_MULTICAST_MAX 10

#undef ULE_DEBUG

#ifdef ULE_DEBUG

static void hexdump(const unsigned char *buf, unsigned short len)
{
	print_hex_dump_debug("", DUMP_PREFIX_OFFSET, 16, 1, buf, len, true);
}

#endif

struct dvb_net_priv {
	int in_use;
	u16 pid;
	struct net_device *net;
	struct dvb_net *host;
	struct dmx_demux *demux;
	struct dmx_section_feed *secfeed;
	struct dmx_section_filter *secfilter;
	struct dmx_ts_feed *tsfeed;
	int multi_num;
	struct dmx_section_filter *multi_secfilter[DVB_NET_MULTICAST_MAX];
	unsigned char multi_macs[DVB_NET_MULTICAST_MAX][6];
	int rx_mode;
#define RX_MODE_UNI 0
#define RX_MODE_MULTI 1
#define RX_MODE_ALL_MULTI 2
#define RX_MODE_PROMISC 3
	struct work_struct set_multicast_list_wq;
	struct work_struct restart_net_feed_wq;
	unsigned char feedtype;			/* Either FEED_TYPE_ or FEED_TYPE_ULE */
	int need_pusi;				/* Set to 1, if synchronization on PUSI required. */
	unsigned char tscc;			/* TS continuity counter after sync on PUSI. */
	struct sk_buff *ule_skb;		/* ULE SNDU decodes into this buffer. */
	unsigned char *ule_next_hdr;		/* Pointer into skb to next ULE extension header. */
	unsigned short ule_sndu_len;		/* ULE SNDU length in bytes, w/o D-Bit. */
	unsigned short ule_sndu_type;		/* ULE SNDU type field, complete. */
	unsigned char ule_sndu_type_1;		/* ULE SNDU type field, if split across 2 TS cells. */
	unsigned char ule_dbit;			/* Whether the DestMAC address present
						 * or not (bit is set). */
	unsigned char ule_bridged;		/* Whether the ULE_BRIDGED extension header was found. */
	int ule_sndu_remain;			/* Nr. of bytes still required for current ULE SNDU. */
	unsigned long ts_count;			/* Current ts cell counter. */
	struct mutex mutex;
};


/**
 *	Determine the packet's protocol ID. The rule here is that we
 *	assume 802.3 if the type field is short enough to be a length.
 *	This is normal practice and works for any 'now in use' protocol.
 *
 *  stolen from eth.c out of the linux kernel, hacked for dvb-device
 *  by Michael Holzt <kju@debian.org>
 */
static __be16 dvb_net_eth_type_trans(struct sk_buff *skb,
				      struct net_device *dev)
{
	struct ethhdr *eth;
	unsigned char *rawp;

	skb_reset_mac_header(skb);
	skb_pull(skb,dev->hard_header_len);
	eth = eth_hdr(skb);

	if (*eth->h_dest & 1) {
		if(ether_addr_equal(eth->h_dest,dev->broadcast))
			skb->pkt_type=PACKET_BROADCAST;
		else
			skb->pkt_type=PACKET_MULTICAST;
	}

	if (ntohs(eth->h_proto) >= ETH_P_802_3_MIN)
		return eth->h_proto;

	rawp = skb->data;

	/**
	 *	This is a magic hack to spot IPX packets. Older Novell breaks
	 *	the protocol design and runs IPX over 802.3 without an 802.2 LLC
	 *	layer. We look for FFFF which isn't a used 802.2 SSAP/DSAP. This
	 *	won't work for fault tolerant netware but does for the rest.
	 */
	if (*(unsigned short *)rawp == 0xFFFF)
		return htons(ETH_P_802_3);

	/**
	 *	Real 802.2 LLC
	 */
	return htons(ETH_P_802_2);
}

#define TS_SZ	188
#define TS_SYNC	0x47
#define TS_TEI	0x80
#define TS_SC	0xC0
#define TS_PUSI	0x40
#define TS_AF_A	0x20
#define TS_AF_D	0x10

/* ULE Extension Header handlers. */

#define ULE_TEST	0
#define ULE_BRIDGED	1

#define ULE_OPTEXTHDR_PADDING 0

static int ule_test_sndu( struct dvb_net_priv *p )
{
	return -1;
}

static int ule_bridged_sndu( struct dvb_net_priv *p )
{
	struct ethhdr *hdr = (struct ethhdr*) p->ule_next_hdr;
	if(ntohs(hdr->h_proto) < ETH_P_802_3_MIN) {
		int framelen = p->ule_sndu_len - ((p->ule_next_hdr+sizeof(struct ethhdr)) - p->ule_skb->data);
		/* A frame Type < ETH_P_802_3_MIN for a bridged frame, introduces a LLC Length field. */
		if(framelen != ntohs(hdr->h_proto)) {
			return -1;
		}
	}
	/* Note:
	 * From RFC4326:
	 *  "A bridged SNDU is a Mandatory Extension Header of Type 1.
	 *   It must be the final (or only) extension header specified in the header chain of a SNDU."
	 * The 'ule_bridged' flag will cause the extension header processing loop to terminate.
	 */
	p->ule_bridged = 1;
	return 0;
}

static int ule_exthdr_padding(struct dvb_net_priv *p)
{
	return 0;
}

/** Handle ULE extension headers.
 *  Function is called after a successful CRC32 verification of an ULE SNDU to complete its decoding.
 *  Returns: >= 0: nr. of bytes consumed by next extension header
 *	     -1:   Mandatory extension header that is not recognized or TEST SNDU; discard.
 */
static int handle_one_ule_extension( struct dvb_net_priv *p )
{
	/* Table of mandatory extension header handlers.  The header type is the index. */
	static int (*ule_mandatory_ext_handlers[255])( struct dvb_net_priv *p ) =
		{ [0] = ule_test_sndu, [1] = ule_bridged_sndu, [2] = NULL,  };

	/* Table of optional extension header handlers.  The header type is the index. */
	static int (*ule_optional_ext_handlers[255])( struct dvb_net_priv *p ) =
		{ [0] = ule_exthdr_padding, [1] = NULL, };

	int ext_len = 0;
	unsigned char hlen = (p->ule_sndu_type & 0x