Commit cb944413 authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller
Browse files

sysctl: add proc_dou8vec_minmax() 



Networking has many sysctls that could fit in one u8.

This patch adds proc_dou8vec_minmax() for this purpose.

Note that the .extra1 and .extra2 fields are pointing
to integers, because it makes conversions easier.

Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent d54e1348

fs/proc/proc_sysctl.c

+6 −0
Original line number Diff line number Diff line
@@ -1108,6 +1108,11 @@ static int sysctl_check_table_array(const char *path, struct ctl_table *table) 
			err |= sysctl_err(path, table, "array not allowed");

	}



	if (table->proc_handler == proc_dou8vec_minmax) {

		if (table->maxlen != sizeof(u8))

			err |= sysctl_err(path, table, "array not allowed");

	}



	return err;

}
@@ -1123,6 +1128,7 @@ static int sysctl_check_table(const char *path, struct ctl_table *table) 
		    (table->proc_handler == proc_douintvec) ||

		    (table->proc_handler == proc_douintvec_minmax) ||

		    (table->proc_handler == proc_dointvec_minmax) ||

		    (table->proc_handler == proc_dou8vec_minmax) ||

		    (table->proc_handler == proc_dointvec_jiffies) ||

		    (table->proc_handler == proc_dointvec_userhz_jiffies) ||

		    (table->proc_handler == proc_dointvec_ms_jiffies) ||

include/linux/sysctl.h

+2 −0
Original line number Diff line number Diff line
@@ -53,6 +53,8 @@ int proc_douintvec(struct ctl_table *, int, void *, size_t *, loff_t *); 
int proc_dointvec_minmax(struct ctl_table *, int, void *, size_t *, loff_t *);

int proc_douintvec_minmax(struct ctl_table *table, int write, void *buffer,

		size_t *lenp, loff_t *ppos);

int proc_dou8vec_minmax(struct ctl_table *table, int write, void *buffer,

			size_t *lenp, loff_t *ppos);

int proc_dointvec_jiffies(struct ctl_table *, int, void *, size_t *, loff_t *);

int proc_dointvec_userhz_jiffies(struct ctl_table *, int, void *, size_t *,

		loff_t *);

kernel/sysctl.c

+65 −0
Original line number Diff line number Diff line
@@ -1034,6 +1034,65 @@ int proc_douintvec_minmax(struct ctl_table *table, int write, 
				 do_proc_douintvec_minmax_conv, &param);

}



/**

 * proc_dou8vec_minmax - read a vector of unsigned chars with min/max values

 * @table: the sysctl table

 * @write: %TRUE if this is a write to the sysctl file

 * @buffer: the user buffer

 * @lenp: the size of the user buffer

 * @ppos: file position

 *

 * Reads/writes up to table->maxlen/sizeof(u8) unsigned chars

 * values from/to the user buffer, treated as an ASCII string. Negative

 * strings are not allowed.

 *

 * This routine will ensure the values are within the range specified by

 * table->extra1 (min) and table->extra2 (max).

 *

 * Returns 0 on success or an error on write when the range check fails.

 */

int proc_dou8vec_minmax(struct ctl_table *table, int write,

			void *buffer, size_t *lenp, loff_t *ppos)

{

	struct ctl_table tmp;

	unsigned int min = 0, max = 255U, val;

	u8 *data = table->data;

	struct do_proc_douintvec_minmax_conv_param param = {

		.min = &min,

		.max = &max,

	};

	int res;



	/* Do not support arrays yet. */

	if (table->maxlen != sizeof(u8))

		return -EINVAL;



	if (table->extra1) {

		min = *(unsigned int *) table->extra1;

		if (min > 255U)

			return -EINVAL;

	}

	if (table->extra2) {

		max = *(unsigned int *) table->extra2;

		if (max > 255U)

			return -EINVAL;

	}



	tmp = *table;



	tmp.maxlen = sizeof(val);

	tmp.data = &val;

	val = *data;

	res = do_proc_douintvec(&tmp, write, buffer, lenp, ppos,

				do_proc_douintvec_minmax_conv, &param);

	if (res)

		return res;

	if (write)

		*data = val;

	return 0;

}

EXPORT_SYMBOL_GPL(proc_dou8vec_minmax);



static int do_proc_dopipe_max_size_conv(unsigned long *lvalp,

					unsigned int *valp,

					int write, void *data)
@@ -1582,6 +1641,12 @@ int proc_douintvec_minmax(struct ctl_table *table, int write, 
	return -ENOSYS;

}



int proc_dou8vec_minmax(struct ctl_table *table, int write,

			void *buffer, size_t *lenp, loff_t *ppos)

{

	return -ENOSYS;

}



int proc_dointvec_jiffies(struct ctl_table *table, int write,

		    void *buffer, size_t *lenp, loff_t *ppos)

{