| 1 | /* |
| 2 | * This program is free software; you can redistribute it and/or modify |
| 3 | * it under the terms of the GNU General Public License as published by |
| 4 | * the Free Software Foundation; either version 2 of the License, or |
| 5 | * (at your option) any later version. |
| 6 | * |
| 7 | * Copyright (C) Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk) |
| 8 | */ |
| 9 | |
| 10 | #include <linux/capability.h> |
| 11 | #include <linux/errno.h> |
| 12 | #include <linux/types.h> |
| 13 | #include <linux/socket.h> |
| 14 | #include <linux/in.h> |
| 15 | #include <linux/kernel.h> |
| 16 | #include <linux/timer.h> |
| 17 | #include <linux/string.h> |
| 18 | #include <linux/sockios.h> |
| 19 | #include <linux/net.h> |
| 20 | #include <linux/spinlock.h> |
| 21 | #include <linux/slab.h> |
| 22 | #include <net/ax25.h> |
| 23 | #include <linux/inet.h> |
| 24 | #include <linux/netdevice.h> |
| 25 | #include <linux/if_arp.h> |
| 26 | #include <linux/skbuff.h> |
| 27 | #include <net/sock.h> |
| 28 | #include <asm/uaccess.h> |
| 29 | #include <linux/fcntl.h> |
| 30 | #include <linux/mm.h> |
| 31 | #include <linux/interrupt.h> |
| 32 | #include <linux/list.h> |
| 33 | #include <linux/notifier.h> |
| 34 | #include <linux/proc_fs.h> |
| 35 | #include <linux/seq_file.h> |
| 36 | #include <linux/stat.h> |
| 37 | #include <linux/sysctl.h> |
| 38 | #include <linux/export.h> |
| 39 | #include <net/ip.h> |
| 40 | #include <net/arp.h> |
| 41 | |
| 42 | /* |
| 43 | * Callsign/UID mapper. This is in kernel space for security on multi-amateur machines. |
| 44 | */ |
| 45 | |
| 46 | static HLIST_HEAD(ax25_uid_list); |
| 47 | static DEFINE_RWLOCK(ax25_uid_lock); |
| 48 | |
| 49 | int ax25_uid_policy; |
| 50 | |
| 51 | EXPORT_SYMBOL(ax25_uid_policy); |
| 52 | |
| 53 | ax25_uid_assoc *ax25_findbyuid(kuid_t uid) |
| 54 | { |
| 55 | ax25_uid_assoc *ax25_uid, *res = NULL; |
| 56 | |
| 57 | read_lock(&ax25_uid_lock); |
| 58 | ax25_uid_for_each(ax25_uid, &ax25_uid_list) { |
| 59 | if (uid_eq(ax25_uid->uid, uid)) { |
| 60 | ax25_uid_hold(ax25_uid); |
| 61 | res = ax25_uid; |
| 62 | break; |
| 63 | } |
| 64 | } |
| 65 | read_unlock(&ax25_uid_lock); |
| 66 | |
| 67 | return res; |
| 68 | } |
| 69 | |
| 70 | EXPORT_SYMBOL(ax25_findbyuid); |
| 71 | |
| 72 | int ax25_uid_ioctl(int cmd, struct sockaddr_ax25 *sax) |
| 73 | { |
| 74 | ax25_uid_assoc *ax25_uid; |
| 75 | ax25_uid_assoc *user; |
| 76 | unsigned long res; |
| 77 | |
| 78 | switch (cmd) { |
| 79 | case SIOCAX25GETUID: |
| 80 | res = -ENOENT; |
| 81 | read_lock(&ax25_uid_lock); |
| 82 | ax25_uid_for_each(ax25_uid, &ax25_uid_list) { |
| 83 | if (ax25cmp(&sax->sax25_call, &ax25_uid->call) == 0) { |
| 84 | res = from_kuid_munged(current_user_ns(), ax25_uid->uid); |
| 85 | break; |
| 86 | } |
| 87 | } |
| 88 | read_unlock(&ax25_uid_lock); |
| 89 | |
| 90 | return res; |
| 91 | |
| 92 | case SIOCAX25ADDUID: |
| 93 | { |
| 94 | kuid_t sax25_kuid; |
| 95 | if (!capable(CAP_NET_ADMIN)) |
| 96 | return -EPERM; |
| 97 | sax25_kuid = make_kuid(current_user_ns(), sax->sax25_uid); |
| 98 | if (!uid_valid(sax25_kuid)) |
| 99 | return -EINVAL; |
| 100 | user = ax25_findbyuid(sax25_kuid); |
| 101 | if (user) { |
| 102 | ax25_uid_put(user); |
| 103 | return -EEXIST; |
| 104 | } |
| 105 | if (sax->sax25_uid == 0) |
| 106 | return -EINVAL; |
| 107 | if ((ax25_uid = kmalloc(sizeof(*ax25_uid), GFP_KERNEL)) == NULL) |
| 108 | return -ENOMEM; |
| 109 | |
| 110 | atomic_set(&ax25_uid->refcount, 1); |
| 111 | ax25_uid->uid = sax25_kuid; |
| 112 | ax25_uid->call = sax->sax25_call; |
| 113 | |
| 114 | write_lock(&ax25_uid_lock); |
| 115 | hlist_add_head(&ax25_uid->uid_node, &ax25_uid_list); |
| 116 | write_unlock(&ax25_uid_lock); |
| 117 | |
| 118 | return 0; |
| 119 | } |
| 120 | case SIOCAX25DELUID: |
| 121 | if (!capable(CAP_NET_ADMIN)) |
| 122 | return -EPERM; |
| 123 | |
| 124 | ax25_uid = NULL; |
| 125 | write_lock(&ax25_uid_lock); |
| 126 | ax25_uid_for_each(ax25_uid, &ax25_uid_list) { |
| 127 | if (ax25cmp(&sax->sax25_call, &ax25_uid->call) == 0) |
| 128 | break; |
| 129 | } |
| 130 | if (ax25_uid == NULL) { |
| 131 | write_unlock(&ax25_uid_lock); |
| 132 | return -ENOENT; |
| 133 | } |
| 134 | hlist_del_init(&ax25_uid->uid_node); |
| 135 | ax25_uid_put(ax25_uid); |
| 136 | write_unlock(&ax25_uid_lock); |
| 137 | |
| 138 | return 0; |
| 139 | |
| 140 | default: |
| 141 | return -EINVAL; |
| 142 | } |
| 143 | |
| 144 | return -EINVAL; /*NOTREACHED */ |
| 145 | } |
| 146 | |
| 147 | #ifdef CONFIG_PROC_FS |
| 148 | |
| 149 | static void *ax25_uid_seq_start(struct seq_file *seq, loff_t *pos) |
| 150 | __acquires(ax25_uid_lock) |
| 151 | { |
| 152 | read_lock(&ax25_uid_lock); |
| 153 | return seq_hlist_start_head(&ax25_uid_list, *pos); |
| 154 | } |
| 155 | |
| 156 | static void *ax25_uid_seq_next(struct seq_file *seq, void *v, loff_t *pos) |
| 157 | { |
| 158 | return seq_hlist_next(v, &ax25_uid_list, pos); |
| 159 | } |
| 160 | |
| 161 | static void ax25_uid_seq_stop(struct seq_file *seq, void *v) |
| 162 | __releases(ax25_uid_lock) |
| 163 | { |
| 164 | read_unlock(&ax25_uid_lock); |
| 165 | } |
| 166 | |
| 167 | static int ax25_uid_seq_show(struct seq_file *seq, void *v) |
| 168 | { |
| 169 | char buf[11]; |
| 170 | |
| 171 | if (v == SEQ_START_TOKEN) |
| 172 | seq_printf(seq, "Policy: %d\n", ax25_uid_policy); |
| 173 | else { |
| 174 | struct ax25_uid_assoc *pt; |
| 175 | |
| 176 | pt = hlist_entry(v, struct ax25_uid_assoc, uid_node); |
| 177 | seq_printf(seq, "%6d %s\n", |
| 178 | from_kuid_munged(seq_user_ns(seq), pt->uid), |
| 179 | ax2asc(buf, &pt->call)); |
| 180 | } |
| 181 | return 0; |
| 182 | } |
| 183 | |
| 184 | static const struct seq_operations ax25_uid_seqops = { |
| 185 | .start = ax25_uid_seq_start, |
| 186 | .next = ax25_uid_seq_next, |
| 187 | .stop = ax25_uid_seq_stop, |
| 188 | .show = ax25_uid_seq_show, |
| 189 | }; |
| 190 | |
| 191 | static int ax25_uid_info_open(struct inode *inode, struct file *file) |
| 192 | { |
| 193 | return seq_open(file, &ax25_uid_seqops); |
| 194 | } |
| 195 | |
| 196 | const struct file_operations ax25_uid_fops = { |
| 197 | .owner = THIS_MODULE, |
| 198 | .open = ax25_uid_info_open, |
| 199 | .read = seq_read, |
| 200 | .llseek = seq_lseek, |
| 201 | .release = seq_release, |
| 202 | }; |
| 203 | |
| 204 | #endif |
| 205 | |
| 206 | /* |
| 207 | * Free all memory associated with UID/Callsign structures. |
| 208 | */ |
| 209 | void __exit ax25_uid_free(void) |
| 210 | { |
| 211 | ax25_uid_assoc *ax25_uid; |
| 212 | |
| 213 | write_lock(&ax25_uid_lock); |
| 214 | again: |
| 215 | ax25_uid_for_each(ax25_uid, &ax25_uid_list) { |
| 216 | hlist_del_init(&ax25_uid->uid_node); |
| 217 | ax25_uid_put(ax25_uid); |
| 218 | goto again; |
| 219 | } |
| 220 | write_unlock(&ax25_uid_lock); |
| 221 | } |