dvb_net.c

linux-2.6.15.6

/*
 * dvb_net.c
 *
 * Copyright (C) 2001 Convergence integrated media GmbH
 *                    Ralph Metzler <[e-mail]>
 * Copyright (C) 2002 Ralph Metzler <[e-mail]>
 *
 * ULE Decapsulation code:
 * Copyright (C) 2003, 2004 gcs - Global Communication & Services GmbH.
 *                      and Department of Scientific Computing
 *                          Paris Lodron University of Salzburg.
 *                          Hilmar Linder <[e-mail]>
 *                      and Wolfram Stering <[e-mail]>
 *
 * ULE Decaps according to draft-ietf-ipdvb-ule-03.txt.
 *
 * 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.
 */

/*
 * FIXME / TODO (dvb_net.c):
 *
 * Unloading does not work for 2.6.9 kernels: a refcount doesn't go to zero.
 *
 * TS_FEED callback is called once for every single TS cell although it is
 * registered (in dvb_net_feed_start()) for 100 TS cells (used for dvb_net_ule()).
 *
 */

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

static int dvb_net_debug;
module_param(dvb_net_debug, int, 0444);
MODULE_PARM_DESC(dvb_net_debug, "enable debug messages");

#define dprintk(x...) do { if (dvb_net_debug) printk(x); } while (0)


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

#define isprint(c)	((c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z') || (c >= '0' && c <= '9'))

static void hexdump( const unsigned char *buf, unsigned short len )
{
	char str[80], octet[10];
	int ofs, i, l;

	for (ofs = 0; ofs < len; ofs += 16) {
		sprintf( str, "%03d: ", ofs );

		for (i = 0; i < 16; i++) {
			if ((i + ofs) < len)
				sprintf( octet, "%02x ", buf[ofs + i] );
			else
				strcpy( octet, "   " );

			strcat( str, octet );
		}
		strcat( str, "  " );
		l = strlen( str );

		for (i = 0; (i < 16) && ((i + ofs) < len); i++)
			str[l++] = isprint( buf[ofs + i] ) ? buf[ofs + i] : '.';

		str[l] = '\0';
		printk( KERN_WARNING "%s\n", str );
	}
}

#endif

struct dvb_net_priv {
	int in_use;
	struct net_device_stats stats;
	u16 pid;
	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 semaphore 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 <[e-mail]>
 */
static unsigned short dvb_net_eth_type_trans(struct sk_buff *skb,
				      struct net_device *dev)
{
	struct ethhdr *eth;
	unsigned char *rawp;

	skb->mac.raw=skb->data;
	skb_pull(skb,dev->hard_header_len);
	eth = eth_hdr(skb);

	if (*eth->h_dest & 1) {
		if(memcmp(eth->h_dest,dev->broadcast, ETH_ALEN)==0)
			skb->pkt_type=PACKET_BROADCAST;
		else
			skb->pkt_type=PACKET_MULTICAST;
	}

	if (ntohs(eth->h_proto) >= 1536)
		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

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

static int ule_bridged_sndu( struct dvb_net_priv *p )
{
	/* BRIDGE SNDU handling sucks in draft-ietf-ipdvb-ule-03.txt.
	 * This has to be the last extension header, otherwise it won't work.
	 * Blame the authors!
	 */
	p->ule_bridged = 1;
	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 ) = { NULL, };

	int ext_len = 0;
	unsigned char hlen = (p->ule_sndu_type & 0x0700) >> 8;
	unsigned char htype = p->ule_sndu_type & 0x00FF;

	/* Discriminate mandatory and optional extension headers. */
	if (hlen == 0) {
		/* Mandatory extension header */
		if (ule_mandatory_ext_handlers[htype]) {
			ext_len = ule_mandatory_ext_handlers[htype]( p );
			p->ule_next_hdr += ext_len;
			if (! p->ule_bridged) {
				p->ule_sndu_type = ntohs( *(unsigned short *)p->ule_next_hdr );
				p->ule_next_hdr += 2;
			} else {
				p->ule_sndu_type = ntohs( *(unsigned short *)(p->ule_next_hdr + ((p->ule_dbit ? 2 : 3) * ETH_ALEN)) );
				/* This assures the extension handling loop will terminate. */
			}
		} else
			ext_len = -1;	/* SNDU has to be discarded. */
	} else {
		/* Optional extension header.  Calculate the length. */
		ext_len = hlen << 2;
		/* Process the optional extension header according to its type. */
		if (ule_optional_ext_handlers[htype])
			(void)ule_optional_ext_handlers[htype]( p );
		p->ule_next_hdr += ext_len;
		p->ule_sndu_type = ntohs( *(unsigned short *)p->ule_next_hdr );
		p->ule_next_hdr += 2;
	}

	return ext_len;
}

static int handle_ule_extensions( struct dvb_net_priv *p )
{
	int total_ext_len = 0, l;

	p->ule_next_hdr = p->ule_skb->data;
	do {
		l = handle_one_ule_extension( p );
		if (l == -1) return -1;	/* Stop extension header processing and discard SNDU. */
		total_ext_len += l;

	} while (p->ule_sndu_type < 1536);

	return total_ext_len;
}


/** Prepare for a new ULE SNDU: reset the decoder state. */
static inline void reset_ule( struct dvb_net_priv *p )
{
	p->ule_skb = NULL;
	p->ule_next_hdr = NULL;
	p->ule_sndu_len = 0;
	p->ule_sndu_type = 0;
	p->ule_sndu_type_1 = 0;
	p->ule_sndu_remain = 0;
	p->ule_dbit = 0xFF;
	p->ule_bridged = 0;
}

/**
 * Decode ULE SNDUs according to draft-ietf-ipdvb-ule-03.txt from a sequence of
 * TS cells of a single PID.
 */
static void dvb_net_ule( struct net_device *dev, const u8 *buf, size_t buf_len )
{
	struct dvb_net_priv *priv = dev->priv;
	unsigned long skipped = 0L;
	u8 *ts, *ts_end, *from_where = NULL, ts_remain = 0, how_much = 0, new_ts = 1;
	struct ethhdr *ethh = NULL;

#ifdef ULE_DEBUG
	/* The code inside ULE_DEBUG keeps a history of the last 100 TS cells processed. */
	static unsigned char ule_hist[100*TS_SZ];
	static unsigned char *ule_where = ule_hist, ule_dump = 0;
#endif

	if (dev == NULL) {
		printk( KERN_ERR "NO netdev struct!\n" );
		return;
	}

	/* For all TS cells in current buffer.
	 * Appearently, we are called for every single TS cell.
	 */
	for (ts = (char *)buf, ts_end = (char *)buf + buf_len; ts < ts_end; /* no default incr. */ ) {

		if (new_ts) {
			/* We are about to process a new TS cell. */

#ifdef ULE_DEBUG
			if (ule_where >= &ule_hist[100*TS_SZ]) ule_where = ule_hist;
			memcpy( ule_where, ts, TS_SZ );
			if (ule_dump) {
				hexdump( ule_where, TS_SZ );
				ule_dump = 0;
			}
			ule_where += TS_SZ;
#endif

			/* Check TS error conditions: sync_byte, transport_error_indicator, scrambling_control . */
			if ((ts[0] != TS_SYNC) || (ts[1] & TS_TEI) || ((ts[3] & TS_SC) != 0)) {
				printk(KERN_WARNING "%lu: Invalid TS cell: SYNC %#x, TEI %u, SC %#x.\n",
				       priv->ts_count, ts[0], ts[1] & TS_TEI >> 7, ts[3] & 0xC0 >> 6);

				/* Drop partly decoded SNDU, reset state, resync on PUSI. */
				if (priv->ule_skb) {
					dev_kfree_skb( priv->ule_skb );
					/* Prepare for next SNDU. */
					((struct dvb_net_priv *) dev->priv)->stats.rx_errors++;
					((struct dvb_net_priv *) dev->priv)->stats.rx_frame_errors++;
				}
				reset_ule(priv);
				priv->need_pusi = 1;

				/* Continue with next TS cell. */
				ts += TS_SZ;
				priv->ts_count++;
				continue;
			}

			ts_remain = 184;
			from_where = ts + 4;
		}
		/* Synchronize on PUSI, if required. */
		if (priv->need_pusi) {
			if (ts[1] & TS_PUSI) {
				/* Find beginning of first ULE SNDU in current TS cell. */
				/* Synchronize continuity counter. */
				priv->tscc = ts[3] & 0x0F;
				/* There is a pointer field here. */
				if (ts[4] > ts_remain) {
					printk(KERN_ERR "%lu: Invalid ULE packet "
					       "(pointer field %d)\n", priv->ts_count, ts[4]);
					ts += TS_SZ;
					priv->ts_count++;
					continue;
				}
				/* Skip to destination of pointer field. */
				from_where = &ts[5] + ts[4];
				ts_remain -= 1 + ts[4];
				skipped = 0;
			} else {
				skipped++;
				ts += TS_SZ;
				priv->ts_count++;
				continue;
			}
		}

		/* Check continuity counter. */
		if (new_ts) {
			if ((ts[3] & 0x0F) == priv->tscc)
				priv->tscc = (priv->tscc + 1) & 0x0F;
			else {
				/* TS discontinuity handling: */
				printk(KERN_WARNING "%lu: TS discontinuity: got %#x, "
				       "exptected %#x.\n", priv->ts_count, ts[3] & 0x0F, priv->tscc);
				/* Drop partly decoded SNDU, reset state, resync on PUSI. */
				if (priv->ule_skb) {
					dev_kfree_skb( priv->ule_skb );
					/* Prepare for next SNDU. */
					// reset_ule(priv);  moved to below.
					((struct dvb_net_priv *) dev->priv)->stats.rx_errors++;
					((struct dvb_net_priv *) dev->priv)->stats.rx_frame_errors++;
				}
				reset_ule(priv);
				/* skip to next PUSI. */
				priv->need_pusi = 1;
				ts += TS_SZ;
				priv->ts_count++;
				continue;
			}
			/* If we still have an incomplete payload, but PUSI is
			 * set; some TS cells are missing.
			 * This is only possible here, if we missed exactly 16 TS
			 * cells (continuity counter wrap). */
			if (ts[1] & TS_PUSI) {
				if (! priv->need_pusi) {
					if (*from_where > 181) {
						/* Pointer field is invalid.  Drop this TS cell and any started ULE SNDU. */
						printk(KERN_WARNING "%lu: Invalid pointer "
						       "field: %u.\n", priv->ts_count, *from_where);

						/* Drop partly decoded SNDU, reset state, resync on PUSI. */
						if (priv->ule_skb) {
							dev_kfree_skb( priv->ule_skb );
							((struct dvb_net_priv *) dev->priv)->stats.rx_errors++;
							((struct dvb_net_priv *) dev->priv)->stats.rx_frame_errors++;
						}
						reset_ule(priv);
						priv->need_pusi = 1;
						ts += TS_SZ;
						priv->ts_count++;
						continue;
					}
					/* Skip pointer field (we're processing a
					 * packed payload). */
					from_where += 1;
					ts_remain -= 1;
				} else
					priv->need_pusi = 0;

				if (priv->ule_sndu_remain > 183) {
					/* Current SNDU lacks more data than there could be available in the
					 * current TS cell. */
					((struct dvb_net_priv *) dev->priv)->stats.rx_errors++;
					((struct dvb_net_priv *) dev->priv)->stats.rx_length_errors++;
					printk(KERN_WARNING "%lu: Expected %d more SNDU bytes, but "
					       "got PUSI (pf %d, ts_remain %d).  Flushing incomplete payload.\n",
					       priv->ts_count, priv->ule_sndu_remain, ts[4], ts_remain);
					dev_kfree_skb(priv->ule_skb);
					/* Prepare for next SNDU. */
					reset_ule(priv);
					/* Resync: go to where pointer field points to: start of next ULE SNDU. */
					from_where += ts[4];
					ts_remain -= ts[4];
				}
			}