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
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+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) ||
+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 *);
+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)
{