diff options
Diffstat (limited to 'net/ax25/ax25_uid.c')
| -rw-r--r-- | net/ax25/ax25_uid.c | 204 |
1 files changed, 204 insertions, 0 deletions
diff --git a/net/ax25/ax25_uid.c b/net/ax25/ax25_uid.c new file mode 100644 index 000000000..241e4680e --- /dev/null +++ b/net/ax25/ax25_uid.c @@ -0,0 +1,204 @@ +// 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); +} |