sysctl.c

Kernel code of linux kernel

				break;

			sprintf(p, "%s%lu", neg ? "-" : "", lval);
			len = strlen(buf);
			if (len > left)
				len = left;
			if(copy_to_user(s, buf, len))
				return -EFAULT;
			left -= len;
			s += len;
		}
	}

	if (!write && !first && left) {
		if(put_user('\n', s))
			return -EFAULT;
		left--, s++;
	}
	if (write) {
		while (left) {
			char c;
			if (get_user(c, s++))
				return -EFAULT;
			if (!isspace(c))
				break;
			left--;
		}
	}
	if (write && first)
		return -EINVAL;
	*lenp -= left;
	*ppos += *lenp;
	return 0;
#undef TMPBUFLEN
}

static int do_proc_dointvec(struct ctl_table *table, int write, struct file *filp,
		  void __user *buffer, size_t *lenp, loff_t *ppos,
		  int (*conv)(int *negp, unsigned long *lvalp, int *valp,
			      int write, void *data),
		  void *data)
{
	return __do_proc_dointvec(table->data, table, write, filp,
			buffer, lenp, ppos, conv, data);
}

/**
 * proc_dointvec - read a vector of integers
 * @table: the sysctl table
 * @write: %TRUE if this is a write to the sysctl file
 * @filp: the file structure
 * @buffer: the user buffer
 * @lenp: the size of the user buffer
 * @ppos: file position
 *
 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
 * values from/to the user buffer, treated as an ASCII string. 
 *
 * Returns 0 on success.
 */
int proc_dointvec(struct ctl_table *table, int write, struct file *filp,
		     void __user *buffer, size_t *lenp, loff_t *ppos)
{
    return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
		    	    NULL,NULL);
}

#define OP_SET	0
#define OP_AND	1
#define OP_OR	2

static int do_proc_dointvec_bset_conv(int *negp, unsigned long *lvalp,
				      int *valp,
				      int write, void *data)
{
	int op = *(int *)data;
	if (write) {
		int val = *negp ? -*lvalp : *lvalp;
		switch(op) {
		case OP_SET:	*valp = val; break;
		case OP_AND:	*valp &= val; break;
		case OP_OR:	*valp |= val; break;
		}
	} else {
		int val = *valp;
		if (val < 0) {
			*negp = -1;
			*lvalp = (unsigned long)-val;
		} else {
			*negp = 0;
			*lvalp = (unsigned long)val;
		}
	}
	return 0;
}

/*
 *	Taint values can only be increased
 */
static int proc_dointvec_taint(struct ctl_table *table, int write, struct file *filp,
			       void __user *buffer, size_t *lenp, loff_t *ppos)
{
	int op;

	if (write && !capable(CAP_SYS_ADMIN))
		return -EPERM;

	op = OP_OR;
	return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
				do_proc_dointvec_bset_conv,&op);
}

struct do_proc_dointvec_minmax_conv_param {
	int *min;
	int *max;
};

static int do_proc_dointvec_minmax_conv(int *negp, unsigned long *lvalp, 
					int *valp, 
					int write, void *data)
{
	struct do_proc_dointvec_minmax_conv_param *param = data;
	if (write) {
		int val = *negp ? -*lvalp : *lvalp;
		if ((param->min && *param->min > val) ||
		    (param->max && *param->max < val))
			return -EINVAL;
		*valp = val;
	} else {
		int val = *valp;
		if (val < 0) {
			*negp = -1;
			*lvalp = (unsigned long)-val;
		} else {
			*negp = 0;
			*lvalp = (unsigned long)val;
		}
	}
	return 0;
}

/**
 * proc_dointvec_minmax - read a vector of integers with min/max values
 * @table: the sysctl table
 * @write: %TRUE if this is a write to the sysctl file
 * @filp: the file structure
 * @buffer: the user buffer
 * @lenp: the size of the user buffer
 * @ppos: file position
 *
 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
 * values from/to the user buffer, treated as an ASCII string.
 *
 * This routine will ensure the values are within the range specified by
 * table->extra1 (min) and table->extra2 (max).
 *
 * Returns 0 on success.
 */
int proc_dointvec_minmax(struct ctl_table *table, int write, struct file *filp,
		  void __user *buffer, size_t *lenp, loff_t *ppos)
{
	struct do_proc_dointvec_minmax_conv_param param = {
		.min = (int *) table->extra1,
		.max = (int *) table->extra2,
	};
	return do_proc_dointvec(table, write, filp, buffer, lenp, ppos,
				do_proc_dointvec_minmax_conv, &param);
}

static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, int write,
				     struct file *filp,
				     void __user *buffer,
				     size_t *lenp, loff_t *ppos,
				     unsigned long convmul,
				     unsigned long convdiv)
{
#define TMPBUFLEN 21
	unsigned long *i, *min, *max, val;
	int vleft, first=1, neg;
	size_t len, left;
	char buf[TMPBUFLEN], *p;
	char __user *s = buffer;
	
	if (!data || !table->maxlen || !*lenp ||
	    (*ppos && !write)) {
		*lenp = 0;
		return 0;
	}
	
	i = (unsigned long *) data;
	min = (unsigned long *) table->extra1;
	max = (unsigned long *) table->extra2;
	vleft = table->maxlen / sizeof(unsigned long);
	left = *lenp;
	
	for (; left && vleft--; i++, min++, max++, first=0) {
		if (write) {
			while (left) {
				char c;
				if (get_user(c, s))
					return -EFAULT;
				if (!isspace(c))
					break;
				left--;
				s++;
			}
			if (!left)
				break;
			neg = 0;
			len = left;
			if (len > TMPBUFLEN-1)
				len = TMPBUFLEN-1;
			if (copy_from_user(buf, s, len))
				return -EFAULT;
			buf[len] = 0;
			p = buf;
			if (*p == '-' && left > 1) {
				neg = 1;
				p++;
			}
			if (*p < '0' || *p > '9')
				break;
			val = simple_strtoul(p, &p, 0) * convmul / convdiv ;
			len = p-buf;
			if ((len < left) && *p && !isspace(*p))
				break;
			if (neg)
				val = -val;
			s += len;
			left -= len;

			if(neg)
				continue;
			if ((min && val < *min) || (max && val > *max))
				continue;
			*i = val;
		} else {
			p = buf;
			if (!first)
				*p++ = '\t';
			sprintf(p, "%lu", convdiv * (*i) / convmul);
			len = strlen(buf);
			if (len > left)
				len = left;
			if(copy_to_user(s, buf, len))
				return -EFAULT;
			left -= len;
			s += len;
		}
	}

	if (!write && !first && left) {
		if(put_user('\n', s))
			return -EFAULT;
		left--, s++;
	}
	if (write) {
		while (left) {
			char c;
			if (get_user(c, s++))
				return -EFAULT;
			if (!isspace(c))
				break;
			left--;
		}
	}
	if (write && first)
		return -EINVAL;
	*lenp -= left;
	*ppos += *lenp;
	return 0;
#undef TMPBUFLEN
}

static int do_proc_doulongvec_minmax(struct ctl_table *table, int write,
				     struct file *filp,
				     void __user *buffer,
				     size_t *lenp, loff_t *ppos,
				     unsigned long convmul,
				     unsigned long convdiv)
{
	return __do_proc_doulongvec_minmax(table->data, table, write,
			filp, buffer, lenp, ppos, convmul, convdiv);
}

/**
 * proc_doulongvec_minmax - read a vector of long integers with min/max values
 * @table: the sysctl table
 * @write: %TRUE if this is a write to the sysctl file
 * @filp: the file structure
 * @buffer: the user buffer
 * @lenp: the size of the user buffer
 * @ppos: file position
 *
 * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
 * values from/to the user buffer, treated as an ASCII string.
 *
 * This routine will ensure the values are within the range specified by
 * table->extra1 (min) and table->extra2 (max).
 *
 * Returns 0 on success.
 */
int proc_doulongvec_minmax(struct ctl_table *table, int write, struct file *filp,
			   void __user *buffer, size_t *lenp, loff_t *ppos)
{
    return do_proc_doulongvec_minmax(table, write, filp, buffer, lenp, ppos, 1l, 1l);
}

/**
 * proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values
 * @table: the sysctl table
 * @write: %TRUE if this is a write to the sysctl file
 * @filp: the file structure
 * @buffer: the user buffer
 * @lenp: the size of the user buffer
 * @ppos: file position
 *
 * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
 * values from/to the user buffer, treated as an ASCII string. The values
 * are treated as milliseconds, and converted to jiffies when they are stored.
 *
 * This routine will ensure the values are within the range specified by
 * table->extra1 (min) and table->extra2 (max).
 *
 * Returns 0 on success.
 */
int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
				      struct file *filp,
				      void __user *buffer,
				      size_t *lenp, loff_t *ppos)
{
    return do_proc_doulongvec_minmax(table, write, filp, buffer,
				     lenp, ppos, HZ, 1000l);
}


static int do_proc_dointvec_jiffies_conv(int *negp, unsigned long *lvalp,
					 int *valp,
					 int write, void *data)
{
	if (write) {
		if (*lvalp > LONG_MAX / HZ)
			return 1;
		*valp = *negp ? -(*lvalp*HZ) : (*lvalp*HZ);
	} else {
		int val = *valp;
		unsigned long lval;
		if (val < 0) {
			*negp = -1;
			lval = (unsigned long)-val;
		} else {
			*negp = 0;
			lval = (unsigned long)val;
		}
		*lvalp = lval / HZ;
	}
	return 0;
}

static int do_proc_dointvec_userhz_jiffies_conv(int *negp, unsigned long *lvalp,
						int *valp,
						int write, void *data)
{
	if (write) {
		if (USER_HZ < HZ && *lvalp > (LONG_MAX / HZ) * USER_HZ)
			return 1;
		*valp = clock_t_to_jiffies(*negp ? -*lvalp : *lvalp);
	} else {
		int val = *valp;
		unsigned long lval;
		if (val < 0) {
			*negp = -1;
			lval = (unsigned long)-val;
		} else {
			*negp = 0;
			lval = (unsigned long)val;
		}
		*lvalp = jiffies_to_clock_t(lval);
	}
	return 0;
}

static int do_proc_dointvec_ms_jiffies_conv(int *negp, unsigned long *lvalp,
					    int *valp,
					    int write, void *data)
{
	if (write) {
		*valp = msecs_to_jiffies(*negp ? -*lvalp : *lvalp);
	} else {
		int val = *valp;
		unsigned long lval;
		if (val < 0) {
			*negp = -1;
			lval = (unsigned long)-val;
		} else {
			*negp = 0;
			lval = (unsigned long)val;
		}
		*lvalp = jiffies_to_msecs(lval);
	}
	return 0;
}

/**
 * proc_dointvec_jiffies - read a vector of integers as seconds
 * @table: the sysctl table
 * @write: %TRUE if this is a write to the sysctl file
 * @filp: the file structure
 * @buffer: the user buffer
 * @lenp: the size of the user buffer
 * @ppos: file position
 *
 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
 * values from/to the user buffer, treated as an ASCII string. 
 * The values read are assumed to be in seconds, and are converted into
 * jiffies.
 *
 * Returns 0 on success.
 */
int proc_dointvec_jiffies(struct ctl_table *table, int write, struct file *filp,
			  void __user *buffer, size_t *lenp, loff_t *ppos)
{
    return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
		    	    do_proc_dointvec_jiffies_conv,NULL);
}

/**
 * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds
 * @table: the sysctl table
 * @write: %TRUE if this is a write to the sysctl file
 * @filp: the file structure
 * @buffer: the user buffer
 * @lenp: the size of the user buffer
 * @ppos: pointer to the file position
 *
 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
 * values from/to the user buffer, treated as an ASCII string. 
 * The values read are assumed to be in 1/USER_HZ seconds, and 
 * are converted into jiffies.
 *
 * Returns 0 on success.
 */
int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write, struct file *filp,
				 void __user *buffer, size_t *lenp, loff_t *ppos)
{
    return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
		    	    do_proc_dointvec_userhz_jiffies_conv,NULL);
}

/**
 * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds
 * @table: the sysctl table
 * @write: %TRUE if this is a write to the sysctl file
 * @filp: the file structure
 * @buffer: the user buffer
 * @lenp: the size of the user buffer
 * @ppos: file position
 * @ppos: the current position in the file
 *
 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
 * values from/to the user buffer, treated as an ASCII string. 
 * The values read are assumed to be in 1/1000 seconds, and 
 * are converted into jiffies.
 *
 * Returns 0 on success.
 */
int proc_dointvec_ms_jiffies(struct ctl_table *table, int write, struct file *filp,
			     void __user *buffer, size_t *lenp, loff_t *ppos)
{
	return do_proc_dointvec(table, write, filp, buffer, lenp, ppos,
				do_proc_dointvec_ms_jiffies_conv, NULL);
}

static int proc_do_cad_pid(struct ctl_table *table, int write, struct file *filp,
			   void __user *buffer, size_t *lenp, loff_t *ppos)
{
	struct pid *new_pid;
	pid_t tmp;
	int r;

	tmp = pid_vnr(cad_pid);

	r = __do_proc_dointvec(&tmp, table, write, filp, buffer,
			       lenp, ppos, NULL, NULL);
	if (r || !write)
		return r;

	new_pid = find_get_pid(tmp);
	if (!new_pid)
		return -ESRCH;

	put_pid(xchg(&cad_pid, new_pid));
	return 0;
}

#else /* CONFIG_PROC_FS */

int proc_dostring(struct ctl_table *table, int write, struct file *filp,
		  void __user *buffer, size_t *lenp, loff_t *ppos)
{
	return -ENOSYS;
}

int proc_dointvec(struct ctl_table *table, int write, struct file *filp,
		  void __user *buffer, size_t *lenp, loff_t *ppos)
{
	return -ENOSYS;
}

int proc_dointvec_minmax(struct ctl_table *table, int write, struct file *filp,
		    void __user *buffer, size_t *lenp, loff_t *ppos)
{
	return -ENOSYS;
}

int proc_dointvec_jiffies(struct ctl_table *table, int write, struct file *filp,
		    void __user *buffer, size_t *lenp, loff_t *ppos)
{
	return -ENOSYS;
}

int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write, struct file *filp,
		    void __user *buffer, size_t *lenp, loff_t *ppos)
{
	return -ENOSYS;
}

int proc_dointvec_ms_jiffies(struct ctl_table *table, int write, struct file *filp,
			     void __user *buffer, size_t *lenp, loff_t *ppos)
{
	return -ENOSYS;
}

int proc_doulongvec_minmax(struct ctl_table *table, int write, struct file *filp,
		    void __user *buffer, size_t *lenp, loff_t *ppos)
{
	return -ENOSYS;
}

int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,