+/* Perform the actual read/write of a sysctl table entry. */
+static int do_sysctl_strategy(struct ctl_table_root *root,
+ struct ctl_table *table,
+ void __user *oldval, size_t __user *oldlenp,
+ void __user *newval, size_t newlen)
+{
+ int op = 0, rc;
+
+ if (oldval)
+ op |= MAY_READ;
+ if (newval)
+ op |= MAY_WRITE;
+ if (sysctl_perm(root, table, op))
+ return -EPERM;
+
+ if (table->strategy) {
+ rc = table->strategy(table, oldval, oldlenp, newval, newlen);
+ if (rc < 0)
+ return rc;
+ if (rc > 0)
+ return 0;
+ }
+
+ /* If there is no strategy routine, or if the strategy returns
+ * zero, proceed with automatic r/w */
+ if (table->data && table->maxlen) {
+ rc = sysctl_data(table, oldval, oldlenp, newval, newlen);
+ if (rc < 0)
+ return rc;
+ }
+ return 0;
+}
+
+static int parse_table(int __user *name, int nlen,
+ void __user *oldval, size_t __user *oldlenp,
+ void __user *newval, size_t newlen,
+ struct ctl_table_root *root,
+ struct ctl_table *table)
+{
+ int n;
+repeat:
+ if (!nlen)
+ return -ENOTDIR;
+ if (get_user(n, name))
+ return -EFAULT;
+ for ( ; table->ctl_name || table->procname; table++) {
+ if (!table->ctl_name)
+ continue;
+ if (n == table->ctl_name) {
+ int error;
+ if (table->child) {
+ if (sysctl_perm(root, table, MAY_EXEC))
+ return -EPERM;
+ name++;
+ nlen--;
+ table = table->child;
+ goto repeat;
+ }
+ error = do_sysctl_strategy(root, table,
+ oldval, oldlenp,
+ newval, newlen);
+ return error;
+ }
+ }
+ return -ENOTDIR;
+}
+