dev.c

《嵌入式系统设计与实例开发实验教材二源码》Linux内核移植与编译实验

	dev = __dev_get_by_index(ifr.ifr_ifindex);
	if (!dev) {
		read_unlock(&dev_base_lock);
		return -ENODEV;
	}

	strcpy(ifr.ifr_name, dev->name);
	read_unlock(&dev_base_lock);

	if (copy_to_user(arg, &ifr, sizeof(struct ifreq)))
		return -EFAULT;
	return 0;
}

/*
 *	Perform a SIOCGIFCONF call. This structure will change
 *	size eventually, and there is nothing I can do about it.
 *	Thus we will need a 'compatibility mode'.
 */

static int dev_ifconf(char *arg)
{
	struct ifconf ifc;
	struct net_device *dev;
	char *pos;
	int len;
	int total;
	int i;

	/*
	 *	Fetch the caller's info block. 
	 */
	
	if (copy_from_user(&ifc, arg, sizeof(struct ifconf)))
		return -EFAULT;

	pos = ifc.ifc_buf;
	len = ifc.ifc_len;

	/*
	 *	Loop over the interfaces, and write an info block for each. 
	 */

	total = 0;
	for (dev = dev_base; dev != NULL; dev = dev->next) {
		for (i=0; i<NPROTO; i++) {
			if (gifconf_list[i]) {
				int done;
				if (pos==NULL) {
					done = gifconf_list[i](dev, NULL, 0);
				} else {
					done = gifconf_list[i](dev, pos+total, len-total);
				}
				if (done<0) {
					return -EFAULT;
				}
				total += done;
			}
		}
  	}

	/*
	 *	All done.  Write the updated control block back to the caller. 
	 */
	ifc.ifc_len = total;

	if (copy_to_user(arg, &ifc, sizeof(struct ifconf)))
		return -EFAULT; 

	/* 
	 * 	Both BSD and Solaris return 0 here, so we do too.
	 */
	return 0;
}

/*
 *	This is invoked by the /proc filesystem handler to display a device
 *	in detail.
 */

#ifdef CONFIG_PROC_FS

static int sprintf_stats(char *buffer, struct net_device *dev)
{
	struct net_device_stats *stats = (dev->get_stats ? dev->get_stats(dev): NULL);
	int size;
	
	if (stats)
		size = sprintf(buffer, "%6s:%8lu %7lu %4lu %4lu %4lu %5lu %10lu %9lu %8lu %7lu %4lu %4lu %4lu %5lu %7lu %10lu\n",
 		   dev->name,
		   stats->rx_bytes,
		   stats->rx_packets, stats->rx_errors,
		   stats->rx_dropped + stats->rx_missed_errors,
		   stats->rx_fifo_errors,
		   stats->rx_length_errors + stats->rx_over_errors
		   + stats->rx_crc_errors + stats->rx_frame_errors,
		   stats->rx_compressed, stats->multicast,
		   stats->tx_bytes,
		   stats->tx_packets, stats->tx_errors, stats->tx_dropped,
		   stats->tx_fifo_errors, stats->collisions,
		   stats->tx_carrier_errors + stats->tx_aborted_errors
		   + stats->tx_window_errors + stats->tx_heartbeat_errors,
		   stats->tx_compressed);
	else
		size = sprintf(buffer, "%6s: No statistics available.\n", dev->name);

	return size;
}

/*
 *	Called from the PROCfs module. This now uses the new arbitrary sized /proc/net interface
 *	to create /proc/net/dev
 */
 
static int dev_get_info(char *buffer, char **start, off_t offset, int length)
{
	int len = 0;
	off_t begin = 0;
	off_t pos = 0;
	int size;
	struct net_device *dev;


	size = sprintf(buffer, 
		"Inter-|   Receive                                                |  Transmit\n"
		" face |bytes    packets errs drop fifo frame compressed multicast|bytes    packets errs drop fifo colls carrier compressed\n");
	
	pos += size;
	len += size;
	

	read_lock(&dev_base_lock);
	for (dev = dev_base; dev != NULL; dev = dev->next) {
		size = sprintf_stats(buffer+len, dev);
		len += size;
		pos = begin + len;
				
		if (pos < offset) {
			len = 0;
			begin = pos;
		}
		if (pos > offset + length)
			break;
	}
	read_unlock(&dev_base_lock);

	*start = buffer + (offset - begin);	/* Start of wanted data */
	len -= (offset - begin);		/* Start slop */
	if (len > length)
		len = length;			/* Ending slop */
	if (len < 0)
		len = 0;
	return len;
}

static int dev_proc_stats(char *buffer, char **start, off_t offset,
			  int length, int *eof, void *data)
{
	int i, lcpu;
	int len=0;

	for (lcpu=0; lcpu<smp_num_cpus; lcpu++) {
		i = cpu_logical_map(lcpu);
		len += sprintf(buffer+len, "%08x %08x %08x %08x %08x %08x %08x %08x %08x\n",
			       netdev_rx_stat[i].total,
			       netdev_rx_stat[i].dropped,
			       netdev_rx_stat[i].time_squeeze,
			       netdev_rx_stat[i].throttled,
			       netdev_rx_stat[i].fastroute_hit,
			       netdev_rx_stat[i].fastroute_success,
			       netdev_rx_stat[i].fastroute_defer,
			       netdev_rx_stat[i].fastroute_deferred_out,
#if 0
			       netdev_rx_stat[i].fastroute_latency_reduction
#else
			       netdev_rx_stat[i].cpu_collision
#endif
			       );
	}

	len -= offset;

	if (len > length)
		len = length;
	if (len < 0)
		len = 0;

	*start = buffer + offset;
	*eof = 1;

	return len;
}

#endif	/* CONFIG_PROC_FS */


#ifdef WIRELESS_EXT
#ifdef CONFIG_PROC_FS

/*
 * Print one entry of /proc/net/wireless
 * This is a clone of /proc/net/dev (just above)
 */
static int sprintf_wireless_stats(char *buffer, struct net_device *dev)
{
	/* Get stats from the driver */
	struct iw_statistics *stats = (dev->get_wireless_stats ?
				       dev->get_wireless_stats(dev) :
				       (struct iw_statistics *) NULL);
	int size;

	if (stats != (struct iw_statistics *) NULL) {
		size = sprintf(buffer,
			       "%6s: %04x  %3d%c  %3d%c  %3d%c  %6d %6d %6d %6d %6d   %6d\n",
			       dev->name,
			       stats->status,
			       stats->qual.qual,
			       stats->qual.updated & 1 ? '.' : ' ',
			       stats->qual.level,
			       stats->qual.updated & 2 ? '.' : ' ',
			       stats->qual.noise,
			       stats->qual.updated & 4 ? '.' : ' ',
			       stats->discard.nwid,
			       stats->discard.code,
			       stats->discard.fragment,
			       stats->discard.retries,
			       stats->discard.misc,
			       stats->miss.beacon);
		stats->qual.updated = 0;
	}
	else
		size = 0;

	return size;
}

/*
 * Print info for /proc/net/wireless (print all entries)
 * This is a clone of /proc/net/dev (just above)
 */
static int dev_get_wireless_info(char * buffer, char **start, off_t offset,
			  int length)
{
	int		len = 0;
	off_t		begin = 0;
	off_t		pos = 0;
	int		size;
	
	struct net_device *	dev;

	size = sprintf(buffer,
		       "Inter-| sta-|   Quality        |   Discarded packets               | Missed\n"
		       " face | tus | link level noise |  nwid  crypt   frag  retry   misc | beacon\n"
			);
	
	pos += size;
	len += size;

	read_lock(&dev_base_lock);
	for (dev = dev_base; dev != NULL; dev = dev->next) {
		size = sprintf_wireless_stats(buffer + len, dev);
		len += size;
		pos = begin + len;

		if (pos < offset) {
			len = 0;
			begin = pos;
		}
		if (pos > offset + length)
			break;
	}
	read_unlock(&dev_base_lock);

	*start = buffer + (offset - begin);	/* Start of wanted data */
	len -= (offset - begin);		/* Start slop */
	if (len > length)
		len = length;			/* Ending slop */
	if (len < 0)
		len = 0;

	return len;
}
#endif	/* CONFIG_PROC_FS */

/*
 *	Allow programatic access to /proc/net/wireless even if /proc
 *	doesn't exist... Also more efficient...
 */
static inline int dev_iwstats(struct net_device *dev, struct ifreq *ifr)
{
	/* Get stats from the driver */
	struct iw_statistics *stats = (dev->get_wireless_stats ?
				       dev->get_wireless_stats(dev) :
				       (struct iw_statistics *) NULL);

	if (stats != (struct iw_statistics *) NULL) {
		struct iwreq *	wrq = (struct iwreq *)ifr;

		/* Copy statistics to the user buffer */
		if(copy_to_user(wrq->u.data.pointer, stats,
				sizeof(struct iw_statistics)))
			return -EFAULT;

		/* Check if we need to clear the update flag */
		if(wrq->u.data.flags != 0)
			stats->qual.updated = 0;
		return(0);
	} else
		return -EOPNOTSUPP;
}
#endif	/* WIRELESS_EXT */

/**
 *	netdev_set_master	-	set up master/slave pair
 *	@slave: slave device
 *	@master: new master device
 *
 *	Changes the master device of the slave. Pass %NULL to break the
 *	bonding. The caller must hold the RTNL semaphore. On a failure
 *	a negative errno code is returned. On success the reference counts
 *	are adjusted, %RTM_NEWLINK is sent to the routing socket and the
 *	function returns zero.
 */
 
int netdev_set_master(struct net_device *slave, struct net_device *master)
{
	struct net_device *old = slave->master;

	ASSERT_RTNL();

	if (master) {
		if (old)
			return -EBUSY;
		dev_hold(master);
	}

	br_write_lock_bh(BR_NETPROTO_LOCK);
	slave->master = master;
	br_write_unlock_bh(BR_NETPROTO_LOCK);

	if (old)
		dev_put(old);

	if (master)
		slave->flags |= IFF_SLAVE;
	else
		slave->flags &= ~IFF_SLAVE;

	rtmsg_ifinfo(RTM_NEWLINK, slave, IFF_SLAVE);
	return 0;
}

/**
 *	dev_set_promiscuity	- update promiscuity count on a device
 *	@dev: device
 *	@inc: modifier
 *
 *	Add or remove promsicuity from a device. While the count in the device
 *	remains above zero the interface remains promiscuous. Once it hits zero
 *	the device reverts back to normal filtering operation. A negative inc
 *	value is used to drop promiscuity on the device.
 */
 
void dev_set_promiscuity(struct net_device *dev, int inc)
{
	unsigned short old_flags = dev->flags;

	dev->flags |= IFF_PROMISC;
	if ((dev->promiscuity += inc) == 0)
		dev->flags &= ~IFF_PROMISC;
	if (dev->flags^old_flags) {
#ifdef CONFIG_NET_FASTROUTE
		if (dev->flags&IFF_PROMISC) {
			netdev_fastroute_obstacles++;
			dev_clear_fastroute(dev);
		} else
			netdev_fastroute_obstacles--;
#endif
		dev_mc_upload(dev);
		printk(KERN_INFO "device %s %s promiscuous mode\n",
		       dev->name, (dev->flags&IFF_PROMISC) ? "entered" : "left");
	}
}

/**
 *	dev_set_allmulti	- update allmulti count on a device
 *	@dev: device
 *	@inc: modifier
 *
 *	Add or remove reception of all multicast frames to a device. While the
 *	count in the device remains above zero the interface remains listening
 *	to all interfaces. Once it hits zero the device reverts back to normal
 *	filtering operation. A negative @inc value is used to drop the counter
 *	when releasing a resource needing all multicasts.
 */

void dev_set_allmulti(struct net_device *dev, int inc)
{
	unsigned short old_flags = dev->flags;

	dev->flags |= IFF_ALLMULTI;
	if ((dev->allmulti += inc) == 0)
		dev->flags &= ~IFF_ALLMULTI;
	if (dev->flags^old_flags)
		dev_mc_upload(dev);
}

int dev_change_flags(struct net_device *dev, unsigned flags)
{
	int ret;
	int old_flags = dev->flags;

	/*
	 *	Set the flags on our device.
	 */

	dev->flags = (flags & (IFF_DEBUG|IFF_NOTRAILERS|IFF_NOARP|IFF_DYNAMIC|
			       IFF_MULTICAST|IFF_PORTSEL|IFF_AUTOMEDIA)) |
				       (dev->flags & (IFF_UP|IFF_VOLATILE|IFF_PROMISC|IFF_ALLMULTI));

	/*
	 *	Load in the correct multicast list now the flags have changed.
	 */				

	dev_mc_upload(dev);

	/*
	 *	Have we downed the interface. We handle IFF_UP ourselves
	 *	according to user attempts to set it, rather than blindly
	 *	setting it.
	 */

	ret = 0;
	if ((old_flags^flags)&IFF_UP)	/* Bit is different  ? */
	{
		ret = ((old_flags & IFF_UP) ? dev_close : dev_open)(dev);

		if (ret == 0) 
			dev_mc_upload(dev);
	}

	if (dev->flags&IFF_UP &&
	    ((old_flags^dev->flags)&~(IFF_UP|IFF_PROMISC|IFF_ALLMULTI|IFF_VOLATILE)))
		notifier_call_chain(&netdev_chain, NETDEV_CHANGE, dev);

	if ((flags^dev->gflags)&IFF_PROMISC) {
		int inc = (flags&IFF_PROMISC) ? +1 : -1;
		dev->gflags ^= IFF_PROMISC;
		dev_set_promiscuity(dev, inc);
	}

	/* NOTE: order of synchronization of IFF_PROMISC and IFF_ALLMULTI
	   is important. Some (broken) drivers set IFF_PROMISC, when
	   IFF_ALLMULTI is requested not asking us and not reporting.
	 */
	if ((flags^dev->gflags)&IFF_ALLMULTI) {
		int inc = (flags&IFF_ALLMULTI) ? +1 : -1;
		dev->gflags ^= IFF_ALLMULTI;
		dev_set_allmulti(dev, inc);
	}

	if (old_flags^dev->flags)
		rtmsg_ifinfo(RTM_NEWLINK, dev, old_flags^dev->flags);

	return ret;
}

/*
 *	Perform the SIOCxIFxxx calls. 
 */
 
static int dev_ifsioc(struct ifreq *ifr, unsigned int cmd)
{
	struct net_device *dev;
	int err;

	if ((dev = __dev_get_by_name(ifr->ifr_name)) == NULL)
		return -ENODEV;

	switch(cmd) 
	{
		case SIOCGIFFLAGS:	/* Get interface flags */
			ifr->ifr_flags = (dev->flags&~(IFF_PROMISC|IFF_ALLMULTI|IFF_RUNNING))
				|(dev->gflags&(IFF_PROMISC|IFF_ALLMULTI));
			if (netif_running(dev) && netif_carrier_ok(dev))
				ifr->ifr_flags |= IFF_RUNNING;
			return 0;

		case SIOCSIFFLAGS:	/* Set interface flags */
			return dev_change_flags(dev, ifr->ifr_flags);
		
		case SIOCGIFMETRIC:	/* Get the metric on the interface (currently unused) */
			ifr->ifr_metric = 0;
			return 0;
			
		case SIOCSIFMETRIC:	/* Set the metric on the interface (currently unused) */
			return -EOPNOTSUPP;
	
		case SIOCGIFMTU:	/* Get the MTU of a device */
			ifr->ifr_mtu = dev->mtu;
			return 0;
	
		case SIOCSIFMTU:	/* Set the MTU of a device */
			if (ifr->ifr_mtu == dev->mtu)
				return 0;

			/*
			 *	MTU must be positive.
			 */
			 
			if (ifr->ifr_mtu<0)
				return -EINVAL;

			if (!netif_device_present(dev))
				return -ENODEV;

			if (dev->change_mtu)
				err = dev->change_mtu(dev, ifr->ifr_mtu);
			else {
				dev->mtu = ifr->ifr_mtu;
				err = 0;
			}
			if (!err && dev->flags&IFF_UP)
				notifier_call_chain(&netdev_chain, NETDEV_CHANGEMTU, dev);
			return err;

		case SIOCGIFHWADDR:
			memcpy(ifr->ifr_hwaddr.sa_data,dev->dev_addr, MAX_ADDR_LEN);
			ifr->ifr_hwaddr.sa_family=dev->type;
			return 0;
				
		case SIOCSIFHWADDR:
			if (dev->set_mac_address == NULL)
				return -EOPNOTSUPP;