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: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Eric Dumazet 2021-03-25 11:08:13 -07:00 committed by David S. Miller
parent d54e1348d8
commit cb94441306
3 changed files with 73 additions and 0 deletions

View file

@ -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) ||

View file

@ -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 *);

View file

@ -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)
{