cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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ax25_uid.c (4419B)

      1// SPDX-License-Identifier: GPL-2.0-or-later
      2/*
      3 *
      4 * Copyright (C) Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk)
      5 */
      6
      7#include <linux/capability.h>
      8#include <linux/errno.h>
      9#include <linux/types.h>
     10#include <linux/socket.h>
     11#include <linux/in.h>
     12#include <linux/kernel.h>
     13#include <linux/timer.h>
     14#include <linux/string.h>
     15#include <linux/sockios.h>
     16#include <linux/net.h>
     17#include <linux/spinlock.h>
     18#include <linux/slab.h>
     19#include <net/ax25.h>
     20#include <linux/inet.h>
     21#include <linux/netdevice.h>
     22#include <linux/if_arp.h>
     23#include <linux/skbuff.h>
     24#include <net/sock.h>
     25#include <linux/uaccess.h>
     26#include <linux/fcntl.h>
     27#include <linux/mm.h>
     28#include <linux/interrupt.h>
     29#include <linux/list.h>
     30#include <linux/notifier.h>
     31#include <linux/proc_fs.h>
     32#include <linux/seq_file.h>
     33#include <linux/stat.h>
     34#include <linux/sysctl.h>
     35#include <linux/export.h>
     36#include <net/ip.h>
     37#include <net/arp.h>
     38
     39/*
     40 *	Callsign/UID mapper. This is in kernel space for security on multi-amateur machines.
     41 */
     42
     43static HLIST_HEAD(ax25_uid_list);
     44static DEFINE_RWLOCK(ax25_uid_lock);
     45
     46int ax25_uid_policy;
     47
     48EXPORT_SYMBOL(ax25_uid_policy);
     49
     50ax25_uid_assoc *ax25_findbyuid(kuid_t uid)
     51{
     52	ax25_uid_assoc *ax25_uid, *res = NULL;
     53
     54	read_lock(&ax25_uid_lock);
     55	ax25_uid_for_each(ax25_uid, &ax25_uid_list) {
     56		if (uid_eq(ax25_uid->uid, uid)) {
     57			ax25_uid_hold(ax25_uid);
     58			res = ax25_uid;
     59			break;
     60		}
     61	}
     62	read_unlock(&ax25_uid_lock);
     63
     64	return res;
     65}
     66
     67EXPORT_SYMBOL(ax25_findbyuid);
     68
     69int ax25_uid_ioctl(int cmd, struct sockaddr_ax25 *sax)
     70{
     71	ax25_uid_assoc *ax25_uid;
     72	ax25_uid_assoc *user;
     73	unsigned long res;
     74
     75	switch (cmd) {
     76	case SIOCAX25GETUID:
     77		res = -ENOENT;
     78		read_lock(&ax25_uid_lock);
     79		ax25_uid_for_each(ax25_uid, &ax25_uid_list) {
     80			if (ax25cmp(&sax->sax25_call, &ax25_uid->call) == 0) {
     81				res = from_kuid_munged(current_user_ns(), ax25_uid->uid);
     82				break;
     83			}
     84		}
     85		read_unlock(&ax25_uid_lock);
     86
     87		return res;
     88
     89	case SIOCAX25ADDUID:
     90	{
     91		kuid_t sax25_kuid;
     92		if (!capable(CAP_NET_ADMIN))
     93			return -EPERM;
     94		sax25_kuid = make_kuid(current_user_ns(), sax->sax25_uid);
     95		if (!uid_valid(sax25_kuid))
     96			return -EINVAL;
     97		user = ax25_findbyuid(sax25_kuid);
     98		if (user) {
     99			ax25_uid_put(user);
    100			return -EEXIST;
    101		}
    102		if (sax->sax25_uid == 0)
    103			return -EINVAL;
    104		if ((ax25_uid = kmalloc(sizeof(*ax25_uid), GFP_KERNEL)) == NULL)
    105			return -ENOMEM;
    106
    107		refcount_set(&ax25_uid->refcount, 1);
    108		ax25_uid->uid  = sax25_kuid;
    109		ax25_uid->call = sax->sax25_call;
    110
    111		write_lock(&ax25_uid_lock);
    112		hlist_add_head(&ax25_uid->uid_node, &ax25_uid_list);
    113		write_unlock(&ax25_uid_lock);
    114
    115		return 0;
    116	}
    117	case SIOCAX25DELUID:
    118		if (!capable(CAP_NET_ADMIN))
    119			return -EPERM;
    120
    121		ax25_uid = NULL;
    122		write_lock(&ax25_uid_lock);
    123		ax25_uid_for_each(ax25_uid, &ax25_uid_list) {
    124			if (ax25cmp(&sax->sax25_call, &ax25_uid->call) == 0)
    125				break;
    126		}
    127		if (ax25_uid == NULL) {
    128			write_unlock(&ax25_uid_lock);
    129			return -ENOENT;
    130		}
    131		hlist_del_init(&ax25_uid->uid_node);
    132		ax25_uid_put(ax25_uid);
    133		write_unlock(&ax25_uid_lock);
    134
    135		return 0;
    136
    137	default:
    138		return -EINVAL;
    139	}
    140
    141	return -EINVAL;	/*NOTREACHED */
    142}
    143
    144#ifdef CONFIG_PROC_FS
    145
    146static void *ax25_uid_seq_start(struct seq_file *seq, loff_t *pos)
    147	__acquires(ax25_uid_lock)
    148{
    149	read_lock(&ax25_uid_lock);
    150	return seq_hlist_start_head(&ax25_uid_list, *pos);
    151}
    152
    153static void *ax25_uid_seq_next(struct seq_file *seq, void *v, loff_t *pos)
    154{
    155	return seq_hlist_next(v, &ax25_uid_list, pos);
    156}
    157
    158static void ax25_uid_seq_stop(struct seq_file *seq, void *v)
    159	__releases(ax25_uid_lock)
    160{
    161	read_unlock(&ax25_uid_lock);
    162}
    163
    164static int ax25_uid_seq_show(struct seq_file *seq, void *v)
    165{
    166	char buf[11];
    167
    168	if (v == SEQ_START_TOKEN)
    169		seq_printf(seq, "Policy: %d\n", ax25_uid_policy);
    170	else {
    171		struct ax25_uid_assoc *pt;
    172
    173		pt = hlist_entry(v, struct ax25_uid_assoc, uid_node);
    174		seq_printf(seq, "%6d %s\n",
    175			from_kuid_munged(seq_user_ns(seq), pt->uid),
    176			ax2asc(buf, &pt->call));
    177	}
    178	return 0;
    179}
    180
    181const struct seq_operations ax25_uid_seqops = {
    182	.start = ax25_uid_seq_start,
    183	.next = ax25_uid_seq_next,
    184	.stop = ax25_uid_seq_stop,
    185	.show = ax25_uid_seq_show,
    186};
    187#endif
    188
    189/*
    190 *	Free all memory associated with UID/Callsign structures.
    191 */
    192void __exit ax25_uid_free(void)
    193{
    194	ax25_uid_assoc *ax25_uid;
    195
    196	write_lock(&ax25_uid_lock);
    197again:
    198	ax25_uid_for_each(ax25_uid, &ax25_uid_list) {
    199		hlist_del_init(&ax25_uid->uid_node);
    200		ax25_uid_put(ax25_uid);
    201		goto again;
    202	}
    203	write_unlock(&ax25_uid_lock);
    204}