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/sched.h> 17 #include <linux/timer.h> 18 #include <linux/string.h> 19 #include <linux/sockios.h> 20 #include <linux/net.h> 21 #include <linux/spinlock.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 <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 HLIST_HEAD(ax25_uid_list); 48 static DEFINE_RWLOCK(ax25_uid_lock); 49 50 int ax25_uid_policy = 0; 51 52 ax25_uid_assoc *ax25_findbyuid(uid_t uid) 53 { 54 ax25_uid_assoc *ax25_uid, *res = NULL; 55 struct hlist_node *node; 56 57 read_lock(&ax25_uid_lock); 58 ax25_uid_for_each(ax25_uid, node, &ax25_uid_list) { 59 if (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 int ax25_uid_ioctl(int cmd, struct sockaddr_ax25 *sax) 71 { 72 ax25_uid_assoc *ax25_uid; 73 struct hlist_node *node; 74 ax25_uid_assoc *user; 75 unsigned long res; 76 77 switch (cmd) { 78 case SIOCAX25GETUID: 79 res = -ENOENT; 80 read_lock(&ax25_uid_lock); 81 ax25_uid_for_each(ax25_uid, node, &ax25_uid_list) { 82 if (ax25cmp(&sax->sax25_call, &ax25_uid->call) == 0) { 83 res = ax25_uid->uid; 84 break; 85 } 86 } 87 read_unlock(&ax25_uid_lock); 88 89 return res; 90 91 case SIOCAX25ADDUID: 92 if (!capable(CAP_NET_ADMIN)) 93 return -EPERM; 94 user = ax25_findbyuid(sax->sax25_uid); 95 if (user) { 96 ax25_uid_put(user); 97 return -EEXIST; 98 } 99 if (sax->sax25_uid == 0) 100 return -EINVAL; 101 if ((ax25_uid = kmalloc(sizeof(*ax25_uid), GFP_KERNEL)) == NULL) 102 return -ENOMEM; 103 104 atomic_set(&ax25_uid->refcount, 1); 105 ax25_uid->uid = sax->sax25_uid; 106 ax25_uid->call = sax->sax25_call; 107 108 write_lock(&ax25_uid_lock); 109 hlist_add_head(&ax25_uid->uid_node, &ax25_uid_list); 110 write_unlock(&ax25_uid_lock); 111 112 return 0; 113 114 case SIOCAX25DELUID: 115 if (!capable(CAP_NET_ADMIN)) 116 return -EPERM; 117 118 ax25_uid = NULL; 119 write_lock(&ax25_uid_lock); 120 ax25_uid_for_each(ax25_uid, node, &ax25_uid_list) { 121 if (ax25cmp(&sax->sax25_call, &ax25_uid->call) == 0) 122 break; 123 } 124 if (ax25_uid == NULL) { 125 write_unlock(&ax25_uid_lock); 126 return -ENOENT; 127 } 128 hlist_del_init(&ax25_uid->uid_node); 129 ax25_uid_put(ax25_uid); 130 write_unlock(&ax25_uid_lock); 131 132 return 0; 133 134 default: 135 return -EINVAL; 136 } 137 138 return -EINVAL; /*NOTREACHED */ 139 } 140 141 #ifdef CONFIG_PROC_FS 142 143 static void *ax25_uid_seq_start(struct seq_file *seq, loff_t *pos) 144 { 145 struct ax25_uid_assoc *pt; 146 struct hlist_node *node; 147 int i = 0; 148 149 read_lock(&ax25_uid_lock); 150 ax25_uid_for_each(pt, node, &ax25_uid_list) { 151 if (i == *pos) 152 return pt; 153 ++i; 154 } 155 return NULL; 156 } 157 158 static void *ax25_uid_seq_next(struct seq_file *seq, void *v, loff_t *pos) 159 { 160 ++*pos; 161 162 return hlist_entry(((ax25_uid_assoc *)v)->uid_node.next, 163 ax25_uid_assoc, uid_node); 164 } 165 166 static void ax25_uid_seq_stop(struct seq_file *seq, void *v) 167 { 168 read_unlock(&ax25_uid_lock); 169 } 170 171 static int ax25_uid_seq_show(struct seq_file *seq, void *v) 172 { 173 char buf[11]; 174 175 if (v == SEQ_START_TOKEN) 176 seq_printf(seq, "Policy: %d\n", ax25_uid_policy); 177 else { 178 struct ax25_uid_assoc *pt = v; 179 180 seq_printf(seq, "%6d %s\n", pt->uid, ax2asc(buf, &pt->call)); 181 } 182 return 0; 183 } 184 185 static 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 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 struct hlist_node *node; 214 215 write_lock(&ax25_uid_lock); 216 ax25_uid_for_each(ax25_uid, node, &ax25_uid_list) { 217 hlist_del_init(&ax25_uid->uid_node); 218 ax25_uid_put(ax25_uid); 219 } 220 write_unlock(&ax25_uid_lock); 221 } 222