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 <asm/system.h> 30 #include <linux/fcntl.h> 31 #include <linux/mm.h> 32 #include <linux/interrupt.h> 33 #include <linux/list.h> 34 #include <linux/notifier.h> 35 #include <linux/proc_fs.h> 36 #include <linux/seq_file.h> 37 #include <linux/stat.h> 38 #include <linux/netfilter.h> 39 #include <linux/sysctl.h> 40 #include <linux/export.h> 41 #include <net/ip.h> 42 #include <net/arp.h> 43 44 /* 45 * Callsign/UID mapper. This is in kernel space for security on multi-amateur machines. 46 */ 47 48 static HLIST_HEAD(ax25_uid_list); 49 static DEFINE_RWLOCK(ax25_uid_lock); 50 51 int ax25_uid_policy; 52 53 EXPORT_SYMBOL(ax25_uid_policy); 54 55 ax25_uid_assoc *ax25_findbyuid(uid_t uid) 56 { 57 ax25_uid_assoc *ax25_uid, *res = NULL; 58 struct hlist_node *node; 59 60 read_lock(&ax25_uid_lock); 61 ax25_uid_for_each(ax25_uid, node, &ax25_uid_list) { 62 if (ax25_uid->uid == uid) { 63 ax25_uid_hold(ax25_uid); 64 res = ax25_uid; 65 break; 66 } 67 } 68 read_unlock(&ax25_uid_lock); 69 70 return res; 71 } 72 73 EXPORT_SYMBOL(ax25_findbyuid); 74 75 int ax25_uid_ioctl(int cmd, struct sockaddr_ax25 *sax) 76 { 77 ax25_uid_assoc *ax25_uid; 78 struct hlist_node *node; 79 ax25_uid_assoc *user; 80 unsigned long res; 81 82 switch (cmd) { 83 case SIOCAX25GETUID: 84 res = -ENOENT; 85 read_lock(&ax25_uid_lock); 86 ax25_uid_for_each(ax25_uid, node, &ax25_uid_list) { 87 if (ax25cmp(&sax->sax25_call, &ax25_uid->call) == 0) { 88 res = ax25_uid->uid; 89 break; 90 } 91 } 92 read_unlock(&ax25_uid_lock); 93 94 return res; 95 96 case SIOCAX25ADDUID: 97 if (!capable(CAP_NET_ADMIN)) 98 return -EPERM; 99 user = ax25_findbyuid(sax->sax25_uid); 100 if (user) { 101 ax25_uid_put(user); 102 return -EEXIST; 103 } 104 if (sax->sax25_uid == 0) 105 return -EINVAL; 106 if ((ax25_uid = kmalloc(sizeof(*ax25_uid), GFP_KERNEL)) == NULL) 107 return -ENOMEM; 108 109 atomic_set(&ax25_uid->refcount, 1); 110 ax25_uid->uid = sax->sax25_uid; 111 ax25_uid->call = sax->sax25_call; 112 113 write_lock(&ax25_uid_lock); 114 hlist_add_head(&ax25_uid->uid_node, &ax25_uid_list); 115 write_unlock(&ax25_uid_lock); 116 117 return 0; 118 119 case SIOCAX25DELUID: 120 if (!capable(CAP_NET_ADMIN)) 121 return -EPERM; 122 123 ax25_uid = NULL; 124 write_lock(&ax25_uid_lock); 125 ax25_uid_for_each(ax25_uid, node, &ax25_uid_list) { 126 if (ax25cmp(&sax->sax25_call, &ax25_uid->call) == 0) 127 break; 128 } 129 if (ax25_uid == NULL) { 130 write_unlock(&ax25_uid_lock); 131 return -ENOENT; 132 } 133 hlist_del_init(&ax25_uid->uid_node); 134 ax25_uid_put(ax25_uid); 135 write_unlock(&ax25_uid_lock); 136 137 return 0; 138 139 default: 140 return -EINVAL; 141 } 142 143 return -EINVAL; /*NOTREACHED */ 144 } 145 146 #ifdef CONFIG_PROC_FS 147 148 static void *ax25_uid_seq_start(struct seq_file *seq, loff_t *pos) 149 __acquires(ax25_uid_lock) 150 { 151 read_lock(&ax25_uid_lock); 152 return seq_hlist_start_head(&ax25_uid_list, *pos); 153 } 154 155 static void *ax25_uid_seq_next(struct seq_file *seq, void *v, loff_t *pos) 156 { 157 return seq_hlist_next(v, &ax25_uid_list, pos); 158 } 159 160 static void ax25_uid_seq_stop(struct seq_file *seq, void *v) 161 __releases(ax25_uid_lock) 162 { 163 read_unlock(&ax25_uid_lock); 164 } 165 166 static int ax25_uid_seq_show(struct seq_file *seq, void *v) 167 { 168 char buf[11]; 169 170 if (v == SEQ_START_TOKEN) 171 seq_printf(seq, "Policy: %d\n", ax25_uid_policy); 172 else { 173 struct ax25_uid_assoc *pt; 174 175 pt = hlist_entry(v, struct ax25_uid_assoc, uid_node); 176 seq_printf(seq, "%6d %s\n", pt->uid, ax2asc(buf, &pt->call)); 177 } 178 return 0; 179 } 180 181 static const 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 }; 187 188 static int ax25_uid_info_open(struct inode *inode, struct file *file) 189 { 190 return seq_open(file, &ax25_uid_seqops); 191 } 192 193 const struct file_operations ax25_uid_fops = { 194 .owner = THIS_MODULE, 195 .open = ax25_uid_info_open, 196 .read = seq_read, 197 .llseek = seq_lseek, 198 .release = seq_release, 199 }; 200 201 #endif 202 203 /* 204 * Free all memory associated with UID/Callsign structures. 205 */ 206 void __exit ax25_uid_free(void) 207 { 208 ax25_uid_assoc *ax25_uid; 209 struct hlist_node *node; 210 211 write_lock(&ax25_uid_lock); 212 again: 213 ax25_uid_for_each(ax25_uid, node, &ax25_uid_list) { 214 hlist_del_init(&ax25_uid->uid_node); 215 ax25_uid_put(ax25_uid); 216 goto again; 217 } 218 write_unlock(&ax25_uid_lock); 219 } 220