linux-sg2042/net/ax25/ax25_uid.c

229 lines
4.8 KiB
C

/*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* Copyright (C) Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk)
*/
#include <linux/errno.h>
#include <linux/types.h>
#include <linux/socket.h>
#include <linux/in.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/timer.h>
#include <linux/string.h>
#include <linux/sockios.h>
#include <linux/net.h>
#include <linux/spinlock.h>
#include <net/ax25.h>
#include <linux/inet.h>
#include <linux/netdevice.h>
#include <linux/if_arp.h>
#include <linux/skbuff.h>
#include <net/sock.h>
#include <asm/uaccess.h>
#include <asm/system.h>
#include <linux/fcntl.h>
#include <linux/mm.h>
#include <linux/interrupt.h>
#include <linux/notifier.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/stat.h>
#include <linux/netfilter.h>
#include <linux/sysctl.h>
#include <net/ip.h>
#include <net/arp.h>
/*
* Callsign/UID mapper. This is in kernel space for security on multi-amateur machines.
*/
static ax25_uid_assoc *ax25_uid_list;
static DEFINE_RWLOCK(ax25_uid_lock);
int ax25_uid_policy = 0;
ax25_address *ax25_findbyuid(uid_t uid)
{
ax25_uid_assoc *ax25_uid;
ax25_address *res = NULL;
read_lock(&ax25_uid_lock);
for (ax25_uid = ax25_uid_list; ax25_uid != NULL; ax25_uid = ax25_uid->next) {
if (ax25_uid->uid == uid) {
res = &ax25_uid->call;
break;
}
}
read_unlock(&ax25_uid_lock);
return NULL;
}
int ax25_uid_ioctl(int cmd, struct sockaddr_ax25 *sax)
{
ax25_uid_assoc *s, *ax25_uid;
unsigned long res;
switch (cmd) {
case SIOCAX25GETUID:
res = -ENOENT;
read_lock(&ax25_uid_lock);
for (ax25_uid = ax25_uid_list; ax25_uid != NULL; ax25_uid = ax25_uid->next) {
if (ax25cmp(&sax->sax25_call, &ax25_uid->call) == 0) {
res = ax25_uid->uid;
break;
}
}
read_unlock(&ax25_uid_lock);
return res;
case SIOCAX25ADDUID:
if (!capable(CAP_NET_ADMIN))
return -EPERM;
if (ax25_findbyuid(sax->sax25_uid))
return -EEXIST;
if (sax->sax25_uid == 0)
return -EINVAL;
if ((ax25_uid = kmalloc(sizeof(*ax25_uid), GFP_KERNEL)) == NULL)
return -ENOMEM;
ax25_uid->uid = sax->sax25_uid;
ax25_uid->call = sax->sax25_call;
write_lock(&ax25_uid_lock);
ax25_uid->next = ax25_uid_list;
ax25_uid_list = ax25_uid;
write_unlock(&ax25_uid_lock);
return 0;
case SIOCAX25DELUID:
if (!capable(CAP_NET_ADMIN))
return -EPERM;
write_lock(&ax25_uid_lock);
for (ax25_uid = ax25_uid_list; ax25_uid != NULL; ax25_uid = ax25_uid->next) {
if (ax25cmp(&sax->sax25_call, &ax25_uid->call) == 0) {
break;
}
}
if (ax25_uid == NULL) {
write_unlock(&ax25_uid_lock);
return -ENOENT;
}
if ((s = ax25_uid_list) == ax25_uid) {
ax25_uid_list = s->next;
write_unlock(&ax25_uid_lock);
kfree(ax25_uid);
return 0;
}
while (s != NULL && s->next != NULL) {
if (s->next == ax25_uid) {
s->next = ax25_uid->next;
write_unlock(&ax25_uid_lock);
kfree(ax25_uid);
return 0;
}
s = s->next;
}
write_unlock(&ax25_uid_lock);
return -ENOENT;
default:
return -EINVAL;
}
return -EINVAL; /*NOTREACHED */
}
#ifdef CONFIG_PROC_FS
static void *ax25_uid_seq_start(struct seq_file *seq, loff_t *pos)
{
struct ax25_uid_assoc *pt;
int i = 1;
read_lock(&ax25_uid_lock);
if (*pos == 0)
return SEQ_START_TOKEN;
for (pt = ax25_uid_list; pt != NULL; pt = pt->next) {
if (i == *pos)
return pt;
++i;
}
return NULL;
}
static void *ax25_uid_seq_next(struct seq_file *seq, void *v, loff_t *pos)
{
++*pos;
return (v == SEQ_START_TOKEN) ? ax25_uid_list :
((struct ax25_uid_assoc *) v)->next;
}
static void ax25_uid_seq_stop(struct seq_file *seq, void *v)
{
read_unlock(&ax25_uid_lock);
}
static int ax25_uid_seq_show(struct seq_file *seq, void *v)
{
if (v == SEQ_START_TOKEN)
seq_printf(seq, "Policy: %d\n", ax25_uid_policy);
else {
struct ax25_uid_assoc *pt = v;
seq_printf(seq, "%6d %s\n", pt->uid, ax2asc(&pt->call));
}
return 0;
}
static struct seq_operations ax25_uid_seqops = {
.start = ax25_uid_seq_start,
.next = ax25_uid_seq_next,
.stop = ax25_uid_seq_stop,
.show = ax25_uid_seq_show,
};
static int ax25_uid_info_open(struct inode *inode, struct file *file)
{
return seq_open(file, &ax25_uid_seqops);
}
struct file_operations ax25_uid_fops = {
.owner = THIS_MODULE,
.open = ax25_uid_info_open,
.read = seq_read,
.llseek = seq_lseek,
.release = seq_release,
};
#endif
/*
* Free all memory associated with UID/Callsign structures.
*/
void __exit ax25_uid_free(void)
{
ax25_uid_assoc *s, *ax25_uid;
write_lock(&ax25_uid_lock);
ax25_uid = ax25_uid_list;
while (ax25_uid != NULL) {
s = ax25_uid;
ax25_uid = ax25_uid->next;
kfree(s);
}
ax25_uid_list = NULL;
write_unlock(&ax25_uid_lock);
}