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 <net/ax25.h> 22 #include <linux/inet.h> 23 #include <linux/netdevice.h> 24 #include <linux/if_arp.h> 25 #include <linux/skbuff.h> 26 #include <net/sock.h> 27 #include <asm/uaccess.h> 28 #include <asm/system.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 <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(uid_t uid) 54 { 55 ax25_uid_assoc *ax25_uid, *res = NULL; 56 struct hlist_node *node; 57 58 read_lock(&ax25_uid_lock); 59 ax25_uid_for_each(ax25_uid, node, &ax25_uid_list) { 60 if (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 struct hlist_node *node; 77 ax25_uid_assoc *user; 78 unsigned long res; 79 80 switch (cmd) { 81 case SIOCAX25GETUID: 82 res = -ENOENT; 83 read_lock(&ax25_uid_lock); 84 ax25_uid_for_each(ax25_uid, node, &ax25_uid_list) { 85 if (ax25cmp(&sax->sax25_call, &ax25_uid->call) == 0) { 86 res = ax25_uid->uid; 87 break; 88 } 89 } 90 read_unlock(&ax25_uid_lock); 91 92 return res; 93 94 case SIOCAX25ADDUID: 95 if (!capable(CAP_NET_ADMIN)) 96 return -EPERM; 97 user = ax25_findbyuid(sax->sax25_uid); 98 if (user) { 99 ax25_uid_put(user); 100 return -EEXIST; 101 } 102 if (sax->sax25_uid == 0) 103 return -EINVAL; 104 if ((ax25_uid = kmalloc(sizeof(*ax25_uid), GFP_KERNEL)) == NULL) 105 return -ENOMEM; 106 107 atomic_set(&ax25_uid->refcount, 1); 108 ax25_uid->uid = sax->sax25_uid; 109 ax25_uid->call = sax->sax25_call; 110 111 write_lock(&ax25_uid_lock); 112 hlist_add_head(&ax25_uid->uid_node, &ax25_uid_list); 113 write_unlock(&ax25_uid_lock); 114 115 return 0; 116 117 case SIOCAX25DELUID: 118 if (!capable(CAP_NET_ADMIN)) 119 return -EPERM; 120 121 ax25_uid = NULL; 122 write_lock(&ax25_uid_lock); 123 ax25_uid_for_each(ax25_uid, node, &ax25_uid_list) { 124 if (ax25cmp(&sax->sax25_call, &ax25_uid->call) == 0) 125 break; 126 } 127 if (ax25_uid == NULL) { 128 write_unlock(&ax25_uid_lock); 129 return -ENOENT; 130 } 131 hlist_del_init(&ax25_uid->uid_node); 132 ax25_uid_put(ax25_uid); 133 write_unlock(&ax25_uid_lock); 134 135 return 0; 136 137 default: 138 return -EINVAL; 139 } 140 141 return -EINVAL; /*NOTREACHED */ 142 } 143 144 #ifdef CONFIG_PROC_FS 145 146 static void *ax25_uid_seq_start(struct seq_file *seq, loff_t *pos) 147 __acquires(ax25_uid_lock) 148 { 149 struct ax25_uid_assoc *pt; 150 struct hlist_node *node; 151 int i = 0; 152 153 read_lock(&ax25_uid_lock); 154 ax25_uid_for_each(pt, node, &ax25_uid_list) { 155 if (i == *pos) 156 return pt; 157 ++i; 158 } 159 return NULL; 160 } 161 162 static void *ax25_uid_seq_next(struct seq_file *seq, void *v, loff_t *pos) 163 { 164 ++*pos; 165 166 return hlist_entry(((ax25_uid_assoc *)v)->uid_node.next, 167 ax25_uid_assoc, uid_node); 168 } 169 170 static void ax25_uid_seq_stop(struct seq_file *seq, void *v) 171 __releases(ax25_uid_lock) 172 { 173 read_unlock(&ax25_uid_lock); 174 } 175 176 static int ax25_uid_seq_show(struct seq_file *seq, void *v) 177 { 178 char buf[11]; 179 180 if (v == SEQ_START_TOKEN) 181 seq_printf(seq, "Policy: %d\n", ax25_uid_policy); 182 else { 183 struct ax25_uid_assoc *pt = v; 184 185 seq_printf(seq, "%6d %s\n", pt->uid, ax2asc(buf, &pt->call)); 186 } 187 return 0; 188 } 189 190 static const struct seq_operations ax25_uid_seqops = { 191 .start = ax25_uid_seq_start, 192 .next = ax25_uid_seq_next, 193 .stop = ax25_uid_seq_stop, 194 .show = ax25_uid_seq_show, 195 }; 196 197 static int ax25_uid_info_open(struct inode *inode, struct file *file) 198 { 199 return seq_open(file, &ax25_uid_seqops); 200 } 201 202 const struct file_operations ax25_uid_fops = { 203 .owner = THIS_MODULE, 204 .open = ax25_uid_info_open, 205 .read = seq_read, 206 .llseek = seq_lseek, 207 .release = seq_release, 208 }; 209 210 #endif 211 212 /* 213 * Free all memory associated with UID/Callsign structures. 214 */ 215 void __exit ax25_uid_free(void) 216 { 217 ax25_uid_assoc *ax25_uid; 218 struct hlist_node *node; 219 220 write_lock(&ax25_uid_lock); 221 again: 222 ax25_uid_for_each(ax25_uid, node, &ax25_uid_list) { 223 hlist_del_init(&ax25_uid->uid_node); 224 ax25_uid_put(ax25_uid); 225 goto again; 226 } 227 write_unlock(&ax25_uid_lock); 228 } 229