linux-stable/net/ax25/ax25_uid.c
Thomas Gleixner 2874c5fd28 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152
Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation either version 2 of the license or at
  your option any later version

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 3029 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:26:32 -07:00

204 lines
4.3 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
*
* Copyright (C) Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk)
*/
#include <linux/capability.h>
#include <linux/errno.h>
#include <linux/types.h>
#include <linux/socket.h>
#include <linux/in.h>
#include <linux/kernel.h>
#include <linux/timer.h>
#include <linux/string.h>
#include <linux/sockios.h>
#include <linux/net.h>
#include <linux/spinlock.h>
#include <linux/slab.h>
#include <net/ax25.h>
#include <linux/inet.h>
#include <linux/netdevice.h>
#include <linux/if_arp.h>
#include <linux/skbuff.h>
#include <net/sock.h>
#include <linux/uaccess.h>
#include <linux/fcntl.h>
#include <linux/mm.h>
#include <linux/interrupt.h>
#include <linux/list.h>
#include <linux/notifier.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/stat.h>
#include <linux/sysctl.h>
#include <linux/export.h>
#include <net/ip.h>
#include <net/arp.h>
/*
* Callsign/UID mapper. This is in kernel space for security on multi-amateur machines.
*/
static HLIST_HEAD(ax25_uid_list);
static DEFINE_RWLOCK(ax25_uid_lock);
int ax25_uid_policy;
EXPORT_SYMBOL(ax25_uid_policy);
ax25_uid_assoc *ax25_findbyuid(kuid_t uid)
{
ax25_uid_assoc *ax25_uid, *res = NULL;
read_lock(&ax25_uid_lock);
ax25_uid_for_each(ax25_uid, &ax25_uid_list) {
if (uid_eq(ax25_uid->uid, uid)) {
ax25_uid_hold(ax25_uid);
res = ax25_uid;
break;
}
}
read_unlock(&ax25_uid_lock);
return res;
}
EXPORT_SYMBOL(ax25_findbyuid);
int ax25_uid_ioctl(int cmd, struct sockaddr_ax25 *sax)
{
ax25_uid_assoc *ax25_uid;
ax25_uid_assoc *user;
unsigned long res;
switch (cmd) {
case SIOCAX25GETUID:
res = -ENOENT;
read_lock(&ax25_uid_lock);
ax25_uid_for_each(ax25_uid, &ax25_uid_list) {
if (ax25cmp(&sax->sax25_call, &ax25_uid->call) == 0) {
res = from_kuid_munged(current_user_ns(), ax25_uid->uid);
break;
}
}
read_unlock(&ax25_uid_lock);
return res;
case SIOCAX25ADDUID:
{
kuid_t sax25_kuid;
if (!capable(CAP_NET_ADMIN))
return -EPERM;
sax25_kuid = make_kuid(current_user_ns(), sax->sax25_uid);
if (!uid_valid(sax25_kuid))
return -EINVAL;
user = ax25_findbyuid(sax25_kuid);
if (user) {
ax25_uid_put(user);
return -EEXIST;
}
if (sax->sax25_uid == 0)
return -EINVAL;
if ((ax25_uid = kmalloc(sizeof(*ax25_uid), GFP_KERNEL)) == NULL)
return -ENOMEM;
refcount_set(&ax25_uid->refcount, 1);
ax25_uid->uid = sax25_kuid;
ax25_uid->call = sax->sax25_call;
write_lock(&ax25_uid_lock);
hlist_add_head(&ax25_uid->uid_node, &ax25_uid_list);
write_unlock(&ax25_uid_lock);
return 0;
}
case SIOCAX25DELUID:
if (!capable(CAP_NET_ADMIN))
return -EPERM;
ax25_uid = NULL;
write_lock(&ax25_uid_lock);
ax25_uid_for_each(ax25_uid, &ax25_uid_list) {
if (ax25cmp(&sax->sax25_call, &ax25_uid->call) == 0)
break;
}
if (ax25_uid == NULL) {
write_unlock(&ax25_uid_lock);
return -ENOENT;
}
hlist_del_init(&ax25_uid->uid_node);
ax25_uid_put(ax25_uid);
write_unlock(&ax25_uid_lock);
return 0;
default:
return -EINVAL;
}
return -EINVAL; /*NOTREACHED */
}
#ifdef CONFIG_PROC_FS
static void *ax25_uid_seq_start(struct seq_file *seq, loff_t *pos)
__acquires(ax25_uid_lock)
{
read_lock(&ax25_uid_lock);
return seq_hlist_start_head(&ax25_uid_list, *pos);
}
static void *ax25_uid_seq_next(struct seq_file *seq, void *v, loff_t *pos)
{
return seq_hlist_next(v, &ax25_uid_list, pos);
}
static void ax25_uid_seq_stop(struct seq_file *seq, void *v)
__releases(ax25_uid_lock)
{
read_unlock(&ax25_uid_lock);
}
static int ax25_uid_seq_show(struct seq_file *seq, void *v)
{
char buf[11];
if (v == SEQ_START_TOKEN)
seq_printf(seq, "Policy: %d\n", ax25_uid_policy);
else {
struct ax25_uid_assoc *pt;
pt = hlist_entry(v, struct ax25_uid_assoc, uid_node);
seq_printf(seq, "%6d %s\n",
from_kuid_munged(seq_user_ns(seq), pt->uid),
ax2asc(buf, &pt->call));
}
return 0;
}
const struct seq_operations ax25_uid_seqops = {
.start = ax25_uid_seq_start,
.next = ax25_uid_seq_next,
.stop = ax25_uid_seq_stop,
.show = ax25_uid_seq_show,
};
#endif
/*
* Free all memory associated with UID/Callsign structures.
*/
void __exit ax25_uid_free(void)
{
ax25_uid_assoc *ax25_uid;
write_lock(&ax25_uid_lock);
again:
ax25_uid_for_each(ax25_uid, &ax25_uid_list) {
hlist_del_init(&ax25_uid->uid_node);
ax25_uid_put(ax25_uid);
goto again;
}
write_unlock(&ax25_uid_lock);
}