proc_fs

Using Proc Filesystem in Drivers

The alternative method for creating a /proc entry is to create and initialize a proc_dir_entry structure and pass it to proc_register_dynamic(version 2.0) or proc_register (version 2.2, which assumes a dynamic file if the inode number in the structure is 0). As an example, consider the following code that scull uses when compiled against 2.0 headers:

struct airo_info {
	......
	struct proc_dir_entry *proc_entry;
        ....

}

Then in setup_proc_entry(dev, dev->priv ) function, a parent directory with the dev name and some files to read information

apriv->proc_entry = create_proc_entry(dev->name,
					      S_IFDIR|airo_perm,
					      airo_entry);

S_IFDIR Shows this is a directory named with device name. See Appendix


/* Setup the Status */
	entry = create_proc_entry("Status",
				  S_IFREG | (S_IRUGO&proc_perm),
				  apriv->proc_entry);
        entry->uid = proc_uid;
        entry->gid = proc_gid;
	entry->data = dev;
        entry->owner = THIS_MODULE;
	SETPROC_OPS(entry, proc_status_ops);

	/* Setup the  Timestamp */
	entry = create_proc_entry("TimeStamps",
				  S_IFREG | proc_perm,
				  apriv->proc_entry);
        entry->uid = proc_uid;
        entry->gid = proc_gid;
	entry->data = dev;
        entry->owner = THIS_MODULE;
	SETPROC_OPS(entry, proc_stamps_ops);

Above show a regular file (S_IFREG) named "Status" is created under the directory, and the permission is set as S_IRUGO&proc_perm,
the SETPROC_OPS(entry, proc_status_ops) is from "#define SETPROC_OPS(entry, ops) (entry)->proc_fops = &(ops)", and proc_status_ops is defined as:

static struct file_operations proc_status_ops = {
	.read		= proc_read,
	.open		= proc_status_open,
	.release	= proc_close
};
static struct file_operations proc_stamps_ops = {
	.read		= proc_read,
	.open		= proc_stamps_open,
	.release	= proc_close
};

There is no "write" operation in above abstract becasue the status of the card is read-only.

static int proc_status_open( struct inode *inode, struct file *file ) {
	struct proc_data *data;
	struct proc_dir_entry *dp = PDE(inode);
	struct net_device *dev = dp->data;
	struct airo_info *apriv = dev->priv;
	CapabilityRid cap_rid;
	StatusRid status_rid;
	int i;

	if ((file->private_data = kmalloc(sizeof(struct proc_data ), GFP_KERNEL)) == NULL)
		return -ENOMEM;
	memset(file->private_data, 0, sizeof(struct proc_data));
	data = (struct proc_data *)file->private_data;
	if ((data->rbuffer = kmalloc( 2048, GFP_KERNEL )) == NULL) {
		kfree (file->private_data);
		return -ENOMEM;
	}

	readStatusRid(apriv, &status_rid, 1);
	readCapabilityRid(apriv, &cap_rid);

        i = sprintf(data->rbuffer, "Status: %s%s%s%s%s%s%s%s%s\n",
                    status_rid.mode & 1 ? "CFG ": "",
                    status_rid.mode & 2 ? "ACT ": "",
                    status_rid.mode & 0x10 ? "SYN ": "",
                    status_rid.mode & 0x20 ? "LNK ": "",
                    status_rid.mode & 0x40 ? "LEAP ": "",
                    status_rid.mode & 0x80 ? "PRIV ": "",
                    status_rid.mode & 0x100 ? "KEY ": "",
                    status_rid.mode & 0x200 ? "WEP ": "",
                    status_rid.mode & 0x8000 ? "ERR ": "");
	sprintf( data->rbuffer+i, "Mode: %x\n"
		 "Signal Strength: %d\n"
		 "Signal Quality: %d\n"
		 "SSID: %-.*s\n"
		 "AP: %-.16s\n"
		 "Freq: %d\n"
		 "BitRate: %dmbs\n"
		 "Driver Version: %s\n"
		 "Device: %s\nManufacturer: %s\nFirmware Version: %s\n"
		 "Radio type: %x\nCountry: %x\nHardware Version: %x\n"
		 "Software Version: %x\nSoftware Subversion: %x\n"
		 "Boot block version: %x\n",
		 (int)status_rid.mode,
		 (int)status_rid.normalizedSignalStrength,
		 (int)status_rid.signalQuality,
		 (int)status_rid.SSIDlen,
		 status_rid.SSID,
		 status_rid.apName,
		 (int)status_rid.channel,
		 (int)status_rid.currentXmitRate/2,
		 version,
		 cap_rid.prodName,
		 cap_rid.manName,
		 cap_rid.prodVer,
		 cap_rid.radioType,
		 cap_rid.country,
		 cap_rid.hardVer,
		 (int)cap_rid.softVer,
		 (int)cap_rid.softSubVer,
		 (int)cap_rid.bootBlockVer );
	data->readlen = strlen( data->rbuffer );
	return 0;
}
static int proc_stamps_open( struct inode *inode, struct file *file ) {
	struct proc_data *data;
	struct proc_dir_entry *dp = PDE(inode);
	struct net_device *dev = dp->data;
	struct airo_info *apriv = dev->priv;
	CapabilityRid cap_rid;
	StatusRid status_rid;
	int i;

	if ((file->private_data = kmalloc(sizeof(struct proc_data ), GFP_KERNEL)) == NULL)
		return -ENOMEM;
	memset(file->private_data, 0, sizeof(struct proc_data));
	data = (struct proc_data *)file->private_data;
	if ((data->rbuffer = kmalloc( 2048, GFP_KERNEL )) == NULL) {
		kfree (file->private_data);
		return -ENOMEM;
	}

	
	sprintf( data->rbuffer, "Mode: Empty\n"
		 "NO DATA NOW\n");
		
	data->readlen = strlen( data->rbuffer );
	return 0;
}

The open function has a lot of operations, basically, the pointer file->private_data is pointed to the proc_data structure filled here.
data->rbuffer is allocated as 2048 Bytes (enough for a status information).
data->readlen = strlen ( data->rbuffer);

struct proc_data {
	int release_buffer;
	int readlen;
	char *rbuffer;
	int writelen;
	int maxwritelen;
	char *wbuffer;
	void (*on_close) (struct inode *, struct file *);
};

#ifndef SETPROC_OPS
#define SETPROC_OPS(entry, ops) (entry)->proc_fops = &(ops)
#endif

static int setup_proc_entry( struct net_device *dev,
			     struct airo_info *apriv ) {
	struct proc_dir_entry *entry;
	/* First setup the device directory */
	apriv->proc_entry = create_proc_entry(dev->name,
					      S_IFDIR|airo_perm,
					      airo_entry);
        apriv->proc_entry->uid = proc_uid;
        apriv->proc_entry->gid = proc_gid;
        apriv->proc_entry->owner = THIS_MODULE;

	/* Setup the StatsDelta */
	entry = create_proc_entry("StatsDelta",
				  S_IFREG | (S_IRUGO&proc_perm),
				  apriv->proc_entry);
        entry->uid = proc_uid;
        entry->gid = proc_gid;
	entry->data = dev;
        entry->owner = THIS_MODULE;
	SETPROC_OPS(entry, proc_statsdelta_ops);

	/* Setup the Stats */
	entry = create_proc_entry("Stats",
				  S_IFREG | (S_IRUGO&proc_perm),
				  apriv->proc_entry);
        entry->uid = proc_uid;
        entry->gid = proc_gid;
	entry->data = dev;
        entry->owner = THIS_MODULE;
	SETPROC_OPS(entry, proc_stats_ops);

	/* Setup the Status */
	entry = create_proc_entry("Status",
				  S_IFREG | (S_IRUGO&proc_perm),
				  apriv->proc_entry);
        entry->uid = proc_uid;
        entry->gid = proc_gid;
	entry->data = dev;
        entry->owner = THIS_MODULE;
	SETPROC_OPS(entry, proc_status_ops);

	/* Setup the Config */
	entry = create_proc_entry("Config",
				  S_IFREG | proc_perm,
				  apriv->proc_entry);
        entry->uid = proc_uid;
        entry->gid = proc_gid;
	entry->data = dev;
        entry->owner = THIS_MODULE;
	SETPROC_OPS(entry, proc_config_ops);

	/* Setup the SSID */
	entry = create_proc_entry("SSID",
				  S_IFREG | proc_perm,
				  apriv->proc_entry);
        entry->uid = proc_uid;
        entry->gid = proc_gid;
	entry->data = dev;
        entry->owner = THIS_MODULE;
	SETPROC_OPS(entry, proc_SSID_ops);

	/* Setup the APList */
	entry = create_proc_entry("APList",
				  S_IFREG | proc_perm,
				  apriv->proc_entry);
        entry->uid = proc_uid;
        entry->gid = proc_gid;
	entry->data = dev;
        entry->owner = THIS_MODULE;
	SETPROC_OPS(entry, proc_APList_ops);

	/* Setup the BSSList */
	entry = create_proc_entry("BSSList",
				  S_IFREG | proc_perm,
				  apriv->proc_entry);
	entry->uid = proc_uid;
	entry->gid = proc_gid;
	entry->data = dev;
        entry->owner = THIS_MODULE;
	SETPROC_OPS(entry, proc_BSSList_ops);

	/* Setup the WepKey */
	entry = create_proc_entry("WepKey",
				  S_IFREG | proc_perm,
				  apriv->proc_entry);
        entry->uid = proc_uid;
        entry->gid = proc_gid;
	entry->data = dev;
        entry->owner = THIS_MODULE;
	SETPROC_OPS(entry, proc_wepkey_ops);

	return 0;
}

static int takedown_proc_entry( struct net_device *dev,
				struct airo_info *apriv ) {
	if ( !apriv->proc_entry->namelen ) return 0;
	remove_proc_entry("Stats",apriv->proc_entry);
	remove_proc_entry("StatsDelta",apriv->proc_entry);
	remove_proc_entry("Status",apriv->proc_entry);
	remove_proc_entry("Config",apriv->proc_entry);
	remove_proc_entry("SSID",apriv->proc_entry);
	remove_proc_entry("APList",apriv->proc_entry);
	remove_proc_entry("BSSList",apriv->proc_entry);
	remove_proc_entry("WepKey",apriv->proc_entry);
	remove_proc_entry(dev->name,airo_entry);
	return 0;
}

/*
 *  What we want from the proc_fs is to be able to efficiently read
 *  and write the configuration.  To do this, we want to read the
 *  configuration when the file is opened and write it when the file is
 *  closed.  So basically we allocate a read buffer at open and fill it
 *  with data, and allocate a write buffer and read it at close.
 */

/*
 *  The read routine is generic, it relies on the preallocated rbuffer
 *  to supply the data.
 */
static ssize_t proc_read( struct file *file,
			  char *buffer,
			  size_t len,
			  loff_t *offset )
{
	int i;
	int pos;
	struct proc_data *priv = (struct proc_data*)file->private_data;

	if( !priv->rbuffer ) return -EINVAL;

	pos = *offset;
	for( i = 0; i+pos < priv->readlen && i < len; i++ ) {
		if (put_user( priv->rbuffer[i+pos], buffer+i ))
			return -EFAULT;
	}
	*offset += i;
	return i;
}

/*
 *  The write routine is generic, it fills in a preallocated rbuffer
 *  to supply the data.
 */
static ssize_t proc_write( struct file *file,
			   const char *buffer,
			   size_t len,
			   loff_t *offset )
{
	int i;
	int pos;
	struct proc_data *priv = (struct proc_data*)file->private_data;

	if ( !priv->wbuffer ) {
		return -EINVAL;
	}

	pos = *offset;

	for( i = 0; i + pos <  priv->maxwritelen &&
		     i < len; i++ ) {
		if (get_user( priv->wbuffer[i+pos], buffer + i ))
			return -EFAULT;
	}
	if ( i+pos > priv->writelen ) priv->writelen = i+file->f_pos;
	*offset += i;
	return i;
}

static int proc_status_open( struct inode *inode, struct file *file ) {
	struct proc_data *data;
	struct proc_dir_entry *dp = PDE(inode);
	struct net_device *dev = dp->data;
	struct airo_info *apriv = dev->priv;
	CapabilityRid cap_rid;
	StatusRid status_rid;
	int i;

	if ((file->private_data = kmalloc(sizeof(struct proc_data ), GFP_KERNEL)) == NULL)
		return -ENOMEM;
	memset(file->private_data, 0, sizeof(struct proc_data));
	data = (struct proc_data *)file->private_data;
	if ((data->rbuffer = kmalloc( 2048, GFP_KERNEL )) == NULL) {
		kfree (file->private_data);
		return -ENOMEM;
	}

	readStatusRid(apriv, &status_rid, 1);
	readCapabilityRid(apriv, &cap_rid);

        i = sprintf(data->rbuffer, "Status: %s%s%s%s%s%s%s%s%s\n",
                    status_rid.mode & 1 ? "CFG ": "",
                    status_rid.mode & 2 ? "ACT ": "",
                    status_rid.mode & 0x10 ? "SYN ": "",
                    status_rid.mode & 0x20 ? "LNK ": "",
                    status_rid.mode & 0x40 ? "LEAP ": "",
                    status_rid.mode & 0x80 ? "PRIV ": "",
                    status_rid.mode & 0x100 ? "KEY ": "",
                    status_rid.mode & 0x200 ? "WEP ": "",
                    status_rid.mode & 0x8000 ? "ERR ": "");
	sprintf( data->rbuffer+i, "Mode: %x\n"
		 "Signal Strength: %d\n"
		 "Signal Quality: %d\n"
		 "SSID: %-.*s\n"
		 "AP: %-.16s\n"
		 "Freq: %d\n"
		 "BitRate: %dmbs\n"
		 "Driver Version: %s\n"
		 "Device: %s\nManufacturer: %s\nFirmware Version: %s\n"
		 "Radio type: %x\nCountry: %x\nHardware Version: %x\n"
		 "Software Version: %x\nSoftware Subversion: %x\n"
		 "Boot block version: %x\n",
		 (int)status_rid.mode,
		 (int)status_rid.normalizedSignalStrength,
		 (int)status_rid.signalQuality,
		 (int)status_rid.SSIDlen,
		 status_rid.SSID,
		 status_rid.apName,
		 (int)status_rid.channel,
		 (int)status_rid.currentXmitRate/2,
		 version,
		 cap_rid.prodName,
		 cap_rid.manName,
		 cap_rid.prodVer,
		 cap_rid.radioType,
		 cap_rid.country,
		 cap_rid.hardVer,
		 (int)cap_rid.softVer,
		 (int)cap_rid.softSubVer,
		 (int)cap_rid.bootBlockVer );
	data->readlen = strlen( data->rbuffer );
	return 0;
}

static int proc_stats_rid_open(struct inode*, struct file*, u16);
static int proc_statsdelta_open( struct inode *inode,
				 struct file *file ) {
	if (file->f_mode&FMODE_WRITE) {
		return proc_stats_rid_open(inode, file, RID_STATSDELTACLEAR);
	}
	return proc_stats_rid_open(inode, file, RID_STATSDELTA);
}

static int proc_stats_open( struct inode *inode, struct file *file ) {
	return proc_stats_rid_open(inode, file, RID_STATS);
}

static int proc_stats_rid_open( struct inode *inode,
				struct file *file,
				u16 rid ) {
	struct proc_data *data;
	struct proc_dir_entry *dp = PDE(inode);
	struct net_device *dev = dp->data;
	struct airo_info *apriv = dev->priv;
	StatsRid stats;
	int i, j;
	u32 *vals = stats.vals;

	if ((file->private_data = kmalloc(sizeof(struct proc_data ), GFP_KERNEL)) == NULL)
		return -ENOMEM;
	memset(file->private_data, 0, sizeof(struct proc_data));
	data = (struct proc_data *)file->private_data;
	if ((data->rbuffer = kmalloc( 4096, GFP_KERNEL )) == NULL) {
		kfree (file->private_data);
		return -ENOMEM;
	}

	readStatsRid(apriv, &stats, rid, 1);

        j = 0;
	for(i=0; statsLabels[i]!=(char *)-1 &&
		    i*4<stats.len; i++){
		if (!statsLabels[i]) continue;
		if (j+strlen(statsLabels[i])+16>4096) {
			printk(KERN_WARNING
			       "airo: Potentially disasterous buffer overflow averted!\n");
			break;
		}
		j+=sprintf(data->rbuffer+j, "%s: %u\n", statsLabels[i], vals[i]);
	}
	if (i*4>=stats.len){
		printk(KERN_WARNING
		       "airo: Got a short rid\n");
	}
	data->readlen = j;
	return 0;
}

static int get_dec_u16( char *buffer, int *start, int limit ) {
	u16 value;
	int valid = 0;
	for( value = 0; buffer[*start] >= '0' &&
		     buffer[*start] <= '9' &&
		     *start < limit; (*start)++ ) {
		valid = 1;
		value *= 10;
		value += buffer[*start] - '0';
	}
	if ( !valid ) return -1;
	return value;
}

static int airo_config_commit(struct net_device *dev,
			      struct iw_request_info *info, void *zwrq,
			      char *extra);

static void proc_config_on_close( struct inode *inode, struct file *file ) {
	struct proc_data *data = file->private_data;
	struct proc_dir_entry *dp = PDE(inode);
	struct net_device *dev = dp->data;
	struct airo_info *ai = dev->priv;
	char *line;

	if ( !data->writelen ) return;

	readConfigRid(ai, 1);
	set_bit (FLAG_COMMIT, &ai->flags);

	line = data->wbuffer;
	while( line[0] ) {
/*** Mode processing */
		if ( !strncmp( line, "Mode: ", 6 ) ) {
			line += 6;
			if ((ai->config.rmode & 0xff) >= RXMODE_RFMON)
					set_bit (FLAG_RESET, &ai->flags);
			ai->config.rmode &= 0xfe00;
			clear_bit (FLAG_802_11, &ai->flags);
			ai->config.opmode &= 0xFF00;
			ai->config.scanMode = SCANMODE_ACTIVE;
			if ( line[0] == 'a' ) {
				ai->config.opmode |= 0;
			} else {
				ai->config.opmode |= 1;
				if ( line[0] == 'r' ) {
					ai->config.rmode |= RXMODE_RFMON | RXMODE_DISABLE_802_3_HEADER;
					ai->config.scanMode = SCANMODE_PASSIVE;
					set_bit (FLAG_802_11, &ai->flags);
				} else if ( line[0] == 'y' ) {
					ai->config.rmode |= RXMODE_RFMON_ANYBSS | RXMODE_DISABLE_802_3_HEADER;
					ai->config.scanMode = SCANMODE_PASSIVE;
					set_bit (FLAG_802_11, &ai->flags);
				} else if ( line[0] == 'l' )
					ai->config.rmode |= RXMODE_LANMON;
			}
			set_bit (FLAG_COMMIT, &ai->flags);
		}

/*** Radio status */
		else if (!strncmp(line,"Radio: ", 7)) {
			line += 7;
			if (!strncmp(line,"off",3)) {
				set_bit (FLAG_RADIO_OFF, &ai->flags);
			} else {
				clear_bit (FLAG_RADIO_OFF, &ai->flags);
			}
		}
/*** NodeName processing */
		else if ( !strncmp( line, "NodeName: ", 10 ) ) {
			int j;

			line += 10;
			memset( ai->config.nodeName, 0, 16 );
/* Do the name, assume a space between the mode and node name */
			for( j = 0; j < 16 && line[j] != '\n'; j++ ) {
				ai->config.nodeName[j] = line[j];
			}
			set_bit (FLAG_COMMIT, &ai->flags);
		}

/*** PowerMode processing */
		else if ( !strncmp( line, "PowerMode: ", 11 ) ) {
			line += 11;
			if ( !strncmp( line, "PSPCAM", 6 ) ) {
				ai->config.powerSaveMode = POWERSAVE_PSPCAM;
				set_bit (FLAG_COMMIT, &ai->flags);
			} else if ( !strncmp( line, "PSP", 3 ) ) {
				ai->config.powerSaveMode = POWERSAVE_PSP;
				set_bit (FLAG_COMMIT, &ai->flags);
			} else {
				ai->config.powerSaveMode = POWERSAVE_CAM;
				set_bit (FLAG_COMMIT, &ai->flags);
			}
		} else if ( !strncmp( line, "DataRates: ", 11 ) ) {
			int v, i = 0, k = 0; /* i is index into line,
						k is index to rates */

			line += 11;
			while((v = get_dec_u16(line, &i, 3))!=-1) {
				ai->config.rates[k++] = (u8)v;
				line += i + 1;
				i = 0;
			}
			set_bit (FLAG_COMMIT, &ai->flags);
		} else if ( !strncmp( line, "Channel: ", 9 ) ) {
			int v, i = 0;
			line += 9;
			v = get_dec_u16(line, &i, i+3);
			if ( v != -1 ) {
				ai->config.channelSet = (u16)v;
				set_bit (FLAG_COMMIT, &ai->flags);
			}
		} else if ( !strncmp( line, "XmitPower: ", 11 ) ) {
			int v, i = 0;
			line += 11;
			v = get_dec_u16(line, &i, i+3);
			if ( v != -1 ) {
				ai->config.txPower = (u16)v;
				set_bit (FLAG_COMMIT, &ai->flags);
			}
		} else if ( !strncmp( line, "WEP: ", 5 ) ) {
			line += 5;
			switch( line[0] ) {
			case 's':
				ai->config.authType = (u16)AUTH_SHAREDKEY;
				break;
			case 'e':
				ai->config.authType = (u16)AUTH_ENCRYPT;
				break;
			default:
				ai->config.authType = (u16)AUTH_OPEN;
				break;
			}
			set_bit (FLAG_COMMIT, &ai->flags);
		} else if ( !strncmp( line, "LongRetryLimit: ", 16 ) ) {
			int v, i = 0;

			line += 16;
			v = get_dec_u16(line, &i, 3);
			v = (v<0) ? 0 : ((v>255) ? 255 : v);
			ai->config.longRetryLimit = (u16)v;
			set_bit (FLAG_COMMIT, &ai->flags);
		} else if ( !strncmp( line, "ShortRetryLimit: ", 17 ) ) {
			int v, i = 0;

			line += 17;
			v = get_dec_u16(line, &i, 3);
			v = (v<0) ? 0 : ((v>255) ? 255 : v);
			ai->config.shortRetryLimit = (u16)v;
			set_bit (FLAG_COMMIT, &ai->flags);
		} else if ( !strncmp( line, "RTSThreshold: ", 14 ) ) {
			int v, i = 0;

			line += 14;
			v = get_dec_u16(line, &i, 4);
			v = (v<0) ? 0 : ((v>2312) ? 2312 : v);
			ai->config.rtsThres = (u16)v;
			set_bit (FLAG_COMMIT, &ai->flags);
		} else if ( !strncmp( line, "TXMSDULifetime: ", 16 ) ) {
			int v, i = 0;

			line += 16;
			v = get_dec_u16(line, &i, 5);
			v = (v<0) ? 0 : v;
			ai->config.txLifetime = (u16)v;
			set_bit (FLAG_COMMIT, &ai->flags);
		} else if ( !strncmp( line, "RXMSDULifetime: ", 16 ) ) {
			int v, i = 0;

			line += 16;
			v = get_dec_u16(line, &i, 5);
			v = (v<0) ? 0 : v;
			ai->config.rxLifetime = (u16)v;
			set_bit (FLAG_COMMIT, &ai->flags);
		} else if ( !strncmp( line, "TXDiversity: ", 13 ) ) {
			ai->config.txDiversity =
				(line[13]=='l') ? 1 :
				((line[13]=='r')? 2: 3);
			set_bit (FLAG_COMMIT, &ai->flags);
		} else if ( !strncmp( line, "RXDiversity: ", 13 ) ) {
			ai->config.rxDiversity =
				(line[13]=='l') ? 1 :
				((line[13]=='r')? 2: 3);
			set_bit (FLAG_COMMIT, &ai->flags);
		} else if ( !strncmp( line, "FragThreshold: ", 15 ) ) {
			int v, i = 0;

			line += 15;
			v = get_dec_u16(line, &i, 4);
			v = (v<256) ? 256 : ((v>2312) ? 2312 : v);
			v = v & 0xfffe; /* Make sure its even */
			ai->config.fragThresh = (u16)v;
			set_bit (FLAG_COMMIT, &ai->flags);
		} else if (!strncmp(line, "Modulation: ", 12)) {
			line += 12;
			switch(*line) {
			case 'd':  ai->config.modulation=MOD_DEFAULT; set_bit(FLAG_COMMIT, &ai->flags); break;
			case 'c':  ai->config.modulation=MOD_CCK; set_bit(FLAG_COMMIT, &ai->flags); break;
			case 'm':  ai->config.modulation=MOD_MOK; set_bit(FLAG_COMMIT, &ai->flags); break;
			default:
				printk( KERN_WARNING "airo: Unknown modulation\n" );
			}
		} else if (!strncmp(line, "Preamble: ", 10)) {
			line += 10;
			switch(*line) {
			case 'a': ai->config.preamble=PREAMBLE_AUTO; set_bit(FLAG_COMMIT, &ai->flags); break;
			case 'l': ai->config.preamble=PREAMBLE_LONG; set_bit(FLAG_COMMIT, &ai->flags); break;
			case 's': ai->config.preamble=PREAMBLE_SHORT; set_bit(FLAG_COMMIT, &ai->flags); break;
		        default: printk(KERN_WARNING "airo: Unknown preamble\n");
			}
		} else {
			printk( KERN_WARNING "Couldn't figure out %s\n", line );
		}
		while( line[0] && line[0] != '\n' ) line++;
		if ( line[0] ) line++;
	}
	airo_config_commit(dev, NULL, NULL, NULL);
}

static char *get_rmode(u16 mode) {
        switch(mode&0xff) {
        case RXMODE_RFMON:  return "rfmon";
        case RXMODE_RFMON_ANYBSS:  return "yna (any) bss rfmon";
        case RXMODE_LANMON:  return "lanmon";
        }
        return "ESS";
}

static int proc_config_open( struct inode *inode, struct file *file ) {
	struct proc_data *data;
	struct proc_dir_entry *dp = PDE(inode);
	struct net_device *dev = dp->data;
	struct airo_info *ai = dev->priv;
	int i;

	if ((file->private_data = kmalloc(sizeof(struct proc_data ), GFP_KERNEL)) == NULL)
		return -ENOMEM;
	memset(file->private_data, 0, sizeof(struct proc_data));
	data = (struct proc_data *)file->private_data;
	if ((data->rbuffer = kmalloc( 2048, GFP_KERNEL )) == NULL) {
		kfree (file->private_data);
		return -ENOMEM;
	}
	if ((data->wbuffer = kmalloc( 2048, GFP_KERNEL )) == NULL) {
		kfree (data->rbuffer);
		kfree (file->private_data);
		return -ENOMEM;
	}
	memset( data->wbuffer, 0, 2048 );
	data->maxwritelen = 2048;
	data->on_close = proc_config_on_close;

	readConfigRid(ai, 1);

	i = sprintf( data->rbuffer,
		     "Mode: %s\n"
		     "Radio: %s\n"
		     "NodeName: %-16s\n"
		     "PowerMode: %s\n"
		     "DataRates: %d %d %d %d %d %d %d %d\n"
		     "Channel: %d\n"
		     "XmitPower: %d\n",
		     (ai->config.opmode & 0xFF) == 0 ? "adhoc" :
		     (ai->config.opmode & 0xFF) == 1 ? get_rmode(ai->config.rmode):
		     (ai->config.opmode & 0xFF) == 2 ? "AP" :
		     (ai->config.opmode & 0xFF) == 3 ? "AP RPTR" : "Error",
		     test_bit(FLAG_RADIO_OFF, &ai->flags) ? "off" : "on",
		     ai->config.nodeName,
		     ai->config.powerSaveMode == 0 ? "CAM" :
		     ai->config.powerSaveMode == 1 ? "PSP" :
		     ai->config.powerSaveMode == 2 ? "PSPCAM" : "Error",
		     (int)ai->config.rates[0],
		     (int)ai->config.rates[1],
		     (int)ai->config.rates[2],
		     (int)ai->config.rates[3],
		     (int)ai->config.rates[4],
		     (int)ai->config.rates[5],
		     (int)ai->config.rates[6],
		     (int)ai->config.rates[7],
		     (int)ai->config.channelSet,
		     (int)ai->config.txPower
		);
	sprintf( data->rbuffer + i,
		 "LongRetryLimit: %d\n"
		 "ShortRetryLimit: %d\n"
		 "RTSThreshold: %d\n"
		 "TXMSDULifetime: %d\n"
		 "RXMSDULifetime: %d\n"
		 "TXDiversity: %s\n"
		 "RXDiversity: %s\n"
		 "FragThreshold: %d\n"
		 "WEP: %s\n"
		 "Modulation: %s\n"
		 "Preamble: %s\n",
		 (int)ai->config.longRetryLimit,
		 (int)ai->config.shortRetryLimit,
		 (int)ai->config.rtsThres,
		 (int)ai->config.txLifetime,
		 (int)ai->config.rxLifetime,
		 ai->config.txDiversity == 1 ? "left" :
		 ai->config.txDiversity == 2 ? "right" : "both",
		 ai->config.rxDiversity == 1 ? "left" :
		 ai->config.rxDiversity == 2 ? "right" : "both",
		 (int)ai->config.fragThresh,
		 ai->config.authType == AUTH_ENCRYPT ? "encrypt" :
		 ai->config.authType == AUTH_SHAREDKEY ? "shared" : "open",
		 ai->config.modulation == 0 ? "default" :
		 ai->config.modulation == MOD_CCK ? "cck" :
		 ai->config.modulation == MOD_MOK ? "mok" : "error",
		 ai->config.preamble == PREAMBLE_AUTO ? "auto" :
		 ai->config.preamble == PREAMBLE_LONG ? "long" :
		 ai->config.preamble == PREAMBLE_SHORT ? "short" : "error"
		);
	data->readlen = strlen( data->rbuffer );
	return 0;
}

static void proc_SSID_on_close( struct inode *inode, struct file *file ) {
	struct proc_data *data = (struct proc_data *)file->private_data;
	struct proc_dir_entry *dp = PDE(inode);
	struct net_device *dev = dp->data;
	struct airo_info *ai = dev->priv;
	SsidRid SSID_rid;
	Resp rsp;
	int i;
	int offset = 0;

	if ( !data->writelen ) return;

	memset( &SSID_rid, 0, sizeof( SSID_rid ) );

	for( i = 0; i < 3; i++ ) {
		int j;
		for( j = 0; j+offset < data->writelen && j < 32 &&
			     data->wbuffer[offset+j] != '\n'; j++ ) {
			SSID_rid.ssids[i].ssid[j] = data->wbuffer[offset+j];
		}
		if ( j == 0 ) break;
		SSID_rid.ssids[i].len = j;
		offset += j;
		while( data->wbuffer[offset] != '\n' &&
		       offset < data->writelen ) offset++;
		offset++;
	}
	if (i)
		SSID_rid.len = sizeof(SSID_rid);
	disable_MAC(ai, 1);
	writeSsidRid(ai, &SSID_rid);
	enable_MAC(ai, &rsp, 1);
}

inline static u8 hexVal(char c) {
	if (c>='0' && c<='9') return c -= '0';
	if (c>='a' && c<='f') return c -= 'a'-10;
	if (c>='A' && c<='F') return c -= 'A'-10;
	return 0;
}

static void proc_APList_on_close( struct inode *inode, struct file *file ) {
	struct proc_data *data = (struct proc_data *)file->private_data;
	struct proc_dir_entry *dp = PDE(inode);
	struct net_device *dev = dp->data;
	struct airo_info *ai = dev->priv;
	APListRid APList_rid;
	Resp rsp;
	int i;

	if ( !data->writelen ) return;

	memset( &APList_rid, 0, sizeof(APList_rid) );
	APList_rid.len = sizeof(APList_rid);

	for( i = 0; i < 4 && data->writelen >= (i+1)*6*3; i++ ) {
		int j;
		for( j = 0; j < 6*3 && data->wbuffer[j+i*6*3]; j++ ) {
			switch(j%3) {
			case 0:
				APList_rid.ap[i][j/3]=
					hexVal(data->wbuffer[j+i*6*3])<<4;
				break;
			case 1:
				APList_rid.ap[i][j/3]|=
					hexVal(data->wbuffer[j+i*6*3]);
				break;
			}
		}
	}
	disable_MAC(ai, 1);
	writeAPListRid(ai, &APList_rid);
	enable_MAC(ai, &rsp, 1);
}

Appendix


#define S_IFMT       0170000     /* type of file (mask for following) */
#define S_IFIFO      0010000     /* first-in/first-out (pipe) */
#define S_IFCHR      0020000     /* character-special file */
#define S_IFDIR      0040000     /* directory */
#define S_IFBLK      0060000     /* blocking device (not used on NetWare) */
#define S_IFREG      0100000     /* regular */
#define S_IFLNK      0120000     /* symbolic link (not used on NetWare) */
#define S_IFSOCK     0140000     /* Berkeley socket */

/* POSIX file modes: owner (user) permission */
#define S_IRWXU      0000700
#define S_IRUSR      0000400
#define S_IWUSR      0000200
#define S_IXUSR      0000100

#define S_IREAD      S_IRUSR
#define S_IWRITE     S_IWUSR
#define S_IEXEC      S_IXUSR

/* POSIX file modes: group permission */
#define S_IRWXG      0000070
#define S_IRGRP      0000040
#define S_IWGRP      0000020
#define S_IXGRP      0000010

/* POSIX file modes: other permission */
#define S_IRWXO      0000007
#define S_IROTH      0000004
#define S_IWOTH      0000002
#define S_IXOTH      0000001