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 <linux/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 refcount_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 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 #endif 191 192 /* 193 * Free all memory associated with UID/Callsign structures. 194 */ 195 void __exit ax25_uid_free(void) 196 { 197 ax25_uid_assoc *ax25_uid; 198 199 write_lock(&ax25_uid_lock); 200 again: 201 ax25_uid_for_each(ax25_uid, &ax25_uid_list) { 202 hlist_del_init(&ax25_uid->uid_node); 203 ax25_uid_put(ax25_uid); 204 goto again; 205 } 206 write_unlock(&ax25_uid_lock); 207 } 208