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/netfilter.h> 38 #include <linux/sysctl.h> 39 #include <linux/export.h> 40 #include <net/ip.h> 41 #include <net/arp.h> 42 43 /* 44 * Callsign/UID mapper. This is in kernel space for security on multi-amateur machines. 45 */ 46 47 static HLIST_HEAD(ax25_uid_list); 48 static DEFINE_RWLOCK(ax25_uid_lock); 49 50 int ax25_uid_policy; 51 52 EXPORT_SYMBOL(ax25_uid_policy); 53 54 ax25_uid_assoc *ax25_findbyuid(kuid_t uid) 55 { 56 ax25_uid_assoc *ax25_uid, *res = NULL; 57 58 read_lock(&ax25_uid_lock); 59 ax25_uid_for_each(ax25_uid, &ax25_uid_list) { 60 if (uid_eq(ax25_uid->uid, uid)) { 61 ax25_uid_hold(ax25_uid); 62 res = ax25_uid; 63 break; 64 } 65 } 66 read_unlock(&ax25_uid_lock); 67 68 return res; 69 } 70 71 EXPORT_SYMBOL(ax25_findbyuid); 72 73 int ax25_uid_ioctl(int cmd, struct sockaddr_ax25 *sax) 74 { 75 ax25_uid_assoc *ax25_uid; 76 ax25_uid_assoc *user; 77 unsigned long res; 78 79 switch (cmd) { 80 case SIOCAX25GETUID: 81 res = -ENOENT; 82 read_lock(&ax25_uid_lock); 83 ax25_uid_for_each(ax25_uid, &ax25_uid_list) { 84 if (ax25cmp(&sax->sax25_call, &ax25_uid->call) == 0) { 85 res = from_kuid_munged(current_user_ns(), ax25_uid->uid); 86 break; 87 } 88 } 89 read_unlock(&ax25_uid_lock); 90 91 return res; 92 93 case SIOCAX25ADDUID: 94 { 95 kuid_t sax25_kuid; 96 if (!capable(CAP_NET_ADMIN)) 97 return -EPERM; 98 sax25_kuid = make_kuid(current_user_ns(), sax->sax25_uid); 99 if (!uid_valid(sax25_kuid)) 100 return -EINVAL; 101 user = ax25_findbyuid(sax25_kuid); 102 if (user) { 103 ax25_uid_put(user); 104 return -EEXIST; 105 } 106 if (sax->sax25_uid == 0) 107 return -EINVAL; 108 if ((ax25_uid = kmalloc(sizeof(*ax25_uid), GFP_KERNEL)) == NULL) 109 return -ENOMEM; 110 111 atomic_set(&ax25_uid->refcount, 1); 112 ax25_uid->uid = sax25_kuid; 113 ax25_uid->call = sax->sax25_call; 114 115 write_lock(&ax25_uid_lock); 116 hlist_add_head(&ax25_uid->uid_node, &ax25_uid_list); 117 write_unlock(&ax25_uid_lock); 118 119 return 0; 120 } 121 case SIOCAX25DELUID: 122 if (!capable(CAP_NET_ADMIN)) 123 return -EPERM; 124 125 ax25_uid = NULL; 126 write_lock(&ax25_uid_lock); 127 ax25_uid_for_each(ax25_uid, &ax25_uid_list) { 128 if (ax25cmp(&sax->sax25_call, &ax25_uid->call) == 0) 129 break; 130 } 131 if (ax25_uid == NULL) { 132 write_unlock(&ax25_uid_lock); 133 return -ENOENT; 134 } 135 hlist_del_init(&ax25_uid->uid_node); 136 ax25_uid_put(ax25_uid); 137 write_unlock(&ax25_uid_lock); 138 139 return 0; 140 141 default: 142 return -EINVAL; 143 } 144 145 return -EINVAL; /*NOTREACHED */ 146 } 147 148 #ifdef CONFIG_PROC_FS 149 150 static void *ax25_uid_seq_start(struct seq_file *seq, loff_t *pos) 151 __acquires(ax25_uid_lock) 152 { 153 read_lock(&ax25_uid_lock); 154 return seq_hlist_start_head(&ax25_uid_list, *pos); 155 } 156 157 static void *ax25_uid_seq_next(struct seq_file *seq, void *v, loff_t *pos) 158 { 159 return seq_hlist_next(v, &ax25_uid_list, pos); 160 } 161 162 static void ax25_uid_seq_stop(struct seq_file *seq, void *v) 163 __releases(ax25_uid_lock) 164 { 165 read_unlock(&ax25_uid_lock); 166 } 167 168 static int ax25_uid_seq_show(struct seq_file *seq, void *v) 169 { 170 char buf[11]; 171 172 if (v == SEQ_START_TOKEN) 173 seq_printf(seq, "Policy: %d\n", ax25_uid_policy); 174 else { 175 struct ax25_uid_assoc *pt; 176 177 pt = hlist_entry(v, struct ax25_uid_assoc, uid_node); 178 seq_printf(seq, "%6d %s\n", 179 from_kuid_munged(seq_user_ns(seq), pt->uid), 180 ax2asc(buf, &pt->call)); 181 } 182 return 0; 183 } 184 185 static const struct seq_operations ax25_uid_seqops = { 186 .start = ax25_uid_seq_start, 187 .next = ax25_uid_seq_next, 188 .stop = ax25_uid_seq_stop, 189 .show = ax25_uid_seq_show, 190 }; 191 192 static int ax25_uid_info_open(struct inode *inode, struct file *file) 193 { 194 return seq_open(file, &ax25_uid_seqops); 195 } 196 197 const struct file_operations ax25_uid_fops = { 198 .owner = THIS_MODULE, 199 .open = ax25_uid_info_open, 200 .read = seq_read, 201 .llseek = seq_lseek, 202 .release = seq_release, 203 }; 204 205 #endif 206 207 /* 208 * Free all memory associated with UID/Callsign structures. 209 */ 210 void __exit ax25_uid_free(void) 211 { 212 ax25_uid_assoc *ax25_uid; 213 214 write_lock(&ax25_uid_lock); 215 again: 216 ax25_uid_for_each(ax25_uid, &ax25_uid_list) { 217 hlist_del_init(&ax25_uid->uid_node); 218 ax25_uid_put(ax25_uid); 219 goto again; 220 } 221 write_unlock(&ax25_uid_lock); 222 } 223