// SPDX-License-Identifier: GPL-2.0-only /* * File: sysctl.c * * Phonet /proc/sys/net/phonet interface implementation * * Copyright (C) 2008 Nokia Corporation. * * Author: RĂ©mi Denis-Courmont */ #include <linux/seqlock.h> #include <linux/sysctl.h> #include <linux/errno.h> #include <linux/init.h> #include <net/sock.h> #include <linux/phonet.h> #include <net/phonet/phonet.h> #define DYNAMIC_PORT_MIN 0x40 #define DYNAMIC_PORT_MAX 0x7f static DEFINE_SEQLOCK(local_port_range_lock); static int local_port_range_min[2] = {0, 0}; static int local_port_range_max[2] = {1023, 1023}; static int local_port_range[2] = {DYNAMIC_PORT_MIN, DYNAMIC_PORT_MAX}; static struct ctl_table_header *phonet_table_hrd; static void set_local_port_range(int range[2]) { write_seqlock(&local_port_range_lock); local_port_range[0] = range[0]; local_port_range[1] = range[1]; write_sequnlock(&local_port_range_lock); } void phonet_get_local_port_range(int *min, int *max) { unsigned int seq; do { seq = read_seqbegin(&local_port_range_lock); if (min) *min = local_port_range[0]; if (max) *max = local_port_range[1]; } while (read_seqretry(&local_port_range_lock, seq)); } static int proc_local_port_range(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos) { int ret; int range[2] = {local_port_range[0], local_port_range[1]}; struct ctl_table tmp = { .data = &range, .maxlen = sizeof(range), .mode = table->mode, .extra1 = &local_port_range_min, .extra2 = &local_port_range_max, }; ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos); if (write && ret == 0) { if (range[1] < range[0]) ret = -EINVAL; else set_local_port_range(range); } return ret; } static struct ctl_table phonet_table[] = { { .procname = "local_port_range", .data = &local_port_range, .maxlen = sizeof(local_port_range), .mode = 0644, .proc_handler = proc_local_port_range, }, { } }; int __init phonet_sysctl_init(void) { phonet_table_hrd = register_net_sysctl(&init_net, "net/phonet", phonet_table); return phonet_table_hrd == NULL ? -ENOMEM : 0; } void phonet_sysctl_exit(void) { unregister_net_sysctl_table(phonet_table_hrd); }