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 struct hlist_node *node; 58 59 read_lock(&ax25_uid_lock); 60 ax25_uid_for_each(ax25_uid, node, &ax25_uid_list) { 61 if (uid_eq(ax25_uid->uid, uid)) { 62 ax25_uid_hold(ax25_uid); 63 res = ax25_uid; 64 break; 65 } 66 } 67 read_unlock(&ax25_uid_lock); 68 69 return res; 70 } 71 72 EXPORT_SYMBOL(ax25_findbyuid); 73 74 int ax25_uid_ioctl(int cmd, struct sockaddr_ax25 *sax) 75 { 76 ax25_uid_assoc *ax25_uid; 77 struct hlist_node *node; 78 ax25_uid_assoc *user; 79 unsigned long res; 80 81 switch (cmd) { 82 case SIOCAX25GETUID: 83 res = -ENOENT; 84 read_lock(&ax25_uid_lock); 85 ax25_uid_for_each(ax25_uid, node, &ax25_uid_list) { 86 if (ax25cmp(&sax->sax25_call, &ax25_uid->call) == 0) { 87 res = from_kuid_munged(current_user_ns(), ax25_uid->uid); 88 break; 89 } 90 } 91 read_unlock(&ax25_uid_lock); 92 93 return res; 94 95 case SIOCAX25ADDUID: 96 { 97 kuid_t sax25_kuid; 98 if (!capable(CAP_NET_ADMIN)) 99 return -EPERM; 100 sax25_kuid = make_kuid(current_user_ns(), sax->sax25_uid); 101 if (!uid_valid(sax25_kuid)) 102 return -EINVAL; 103 user = ax25_findbyuid(sax25_kuid); 104 if (user) { 105 ax25_uid_put(user); 106 return -EEXIST; 107 } 108 if (sax->sax25_uid == 0) 109 return -EINVAL; 110 if ((ax25_uid = kmalloc(sizeof(*ax25_uid), GFP_KERNEL)) == NULL) 111 return -ENOMEM; 112 113 atomic_set(&ax25_uid->refcount, 1); 114 ax25_uid->uid = sax25_kuid; 115 ax25_uid->call = sax->sax25_call; 116 117 write_lock(&ax25_uid_lock); 118 hlist_add_head(&ax25_uid->uid_node, &ax25_uid_list); 119 write_unlock(&ax25_uid_lock); 120 121 return 0; 122 } 123 case SIOCAX25DELUID: 124 if (!capable(CAP_NET_ADMIN)) 125 return -EPERM; 126 127 ax25_uid = NULL; 128 write_lock(&ax25_uid_lock); 129 ax25_uid_for_each(ax25_uid, node, &ax25_uid_list) { 130 if (ax25cmp(&sax->sax25_call, &ax25_uid->call) == 0) 131 break; 132 } 133 if (ax25_uid == NULL) { 134 write_unlock(&ax25_uid_lock); 135 return -ENOENT; 136 } 137 hlist_del_init(&ax25_uid->uid_node); 138 ax25_uid_put(ax25_uid); 139 write_unlock(&ax25_uid_lock); 140 141 return 0; 142 143 default: 144 return -EINVAL; 145 } 146 147 return -EINVAL; /*NOTREACHED */ 148 } 149 150 #ifdef CONFIG_PROC_FS 151 152 static void *ax25_uid_seq_start(struct seq_file *seq, loff_t *pos) 153 __acquires(ax25_uid_lock) 154 { 155 read_lock(&ax25_uid_lock); 156 return seq_hlist_start_head(&ax25_uid_list, *pos); 157 } 158 159 static void *ax25_uid_seq_next(struct seq_file *seq, void *v, loff_t *pos) 160 { 161 return seq_hlist_next(v, &ax25_uid_list, pos); 162 } 163 164 static void ax25_uid_seq_stop(struct seq_file *seq, void *v) 165 __releases(ax25_uid_lock) 166 { 167 read_unlock(&ax25_uid_lock); 168 } 169 170 static int ax25_uid_seq_show(struct seq_file *seq, void *v) 171 { 172 char buf[11]; 173 174 if (v == SEQ_START_TOKEN) 175 seq_printf(seq, "Policy: %d\n", ax25_uid_policy); 176 else { 177 struct ax25_uid_assoc *pt; 178 179 pt = hlist_entry(v, struct ax25_uid_assoc, uid_node); 180 seq_printf(seq, "%6d %s\n", 181 from_kuid_munged(seq_user_ns(seq), pt->uid), 182 ax2asc(buf, &pt->call)); 183 } 184 return 0; 185 } 186 187 static const struct seq_operations ax25_uid_seqops = { 188 .start = ax25_uid_seq_start, 189 .next = ax25_uid_seq_next, 190 .stop = ax25_uid_seq_stop, 191 .show = ax25_uid_seq_show, 192 }; 193 194 static int ax25_uid_info_open(struct inode *inode, struct file *file) 195 { 196 return seq_open(file, &ax25_uid_seqops); 197 } 198 199 const struct file_operations ax25_uid_fops = { 200 .owner = THIS_MODULE, 201 .open = ax25_uid_info_open, 202 .read = seq_read, 203 .llseek = seq_lseek, 204 .release = seq_release, 205 }; 206 207 #endif 208 209 /* 210 * Free all memory associated with UID/Callsign structures. 211 */ 212 void __exit ax25_uid_free(void) 213 { 214 ax25_uid_assoc *ax25_uid; 215 struct hlist_node *node; 216 217 write_lock(&ax25_uid_lock); 218 again: 219 ax25_uid_for_each(ax25_uid, node, &ax25_uid_list) { 220 hlist_del_init(&ax25_uid->uid_node); 221 ax25_uid_put(ax25_uid); 222 goto again; 223 } 224 write_unlock(&ax25_uid_lock); 225 } 226