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