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linux/net/ax25/af_ax25.c
Lars Kellogg-Stedman 3c34fb0bd4 ax25: Fix refcount imbalance on inbound connections 
When releasing a socket in ax25_release(), we call netdev_put() to
decrease the refcount on the associated ax.25 device. However, the
execution path for accepting an incoming connection never calls
netdev_hold(). This imbalance leads to refcount errors, and ultimately
to kernel crashes.

A typical call trace for the above situation will start with one of the
following errors:

    refcount_t: decrement hit 0; leaking memory.
    refcount_t: underflow; use-after-free.

And will then have a trace like:

    Call Trace:
    <TASK>
    ? show_regs+0x64/0x70
    ? __warn+0x83/0x120
    ? refcount_warn_saturate+0xb2/0x100
    ? report_bug+0x158/0x190
    ? prb_read_valid+0x20/0x30
    ? handle_bug+0x3e/0x70
    ? exc_invalid_op+0x1c/0x70
    ? asm_exc_invalid_op+0x1f/0x30
    ? refcount_warn_saturate+0xb2/0x100
    ? refcount_warn_saturate+0xb2/0x100
    ax25_release+0x2ad/0x360
    __sock_release+0x35/0xa0
    sock_close+0x19/0x20
    [...]

On reboot (or any attempt to remove the interface), the kernel gets
stuck in an infinite loop:

    unregister_netdevice: waiting for ax0 to become free. Usage count = 0

This patch corrects these issues by ensuring that we call netdev_hold()
and ax25_dev_hold() for new connections in ax25_accept(). This makes the
logic leading to ax25_accept() match the logic for ax25_bind(): in both
cases we increment the refcount, which is ultimately decremented in
ax25_release().

Fixes: 9fd75b66b8 ("ax25: Fix refcount leaks caused by ax25_cb_del()")
Signed-off-by: Lars Kellogg-Stedman <lars@oddbit.com>
Tested-by: Duoming Zhou <duoming@zju.edu.cn>
Tested-by: Dan Cross <crossd@gmail.com>
Tested-by: Chris Maness <christopher.maness@gmail.com>
Reviewed-by: Dan Carpenter <dan.carpenter@linaro.org>
Link: https://lore.kernel.org/r/20240529210242.3346844-2-lars@oddbit.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-06-01 15:49:26 -07:00

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// SPDX-License-Identifier: GPL-2.0-or-later
/*
*
* Copyright (C) Alan Cox GW4PTS (alan@lxorguk.ukuu.org.uk)
* Copyright (C) Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk)
* Copyright (C) Darryl Miles G7LED (dlm@g7led.demon.co.uk)
* Copyright (C) Steven Whitehouse GW7RRM (stevew@acm.org)
* Copyright (C) Joerg Reuter DL1BKE (jreuter@yaina.de)
* Copyright (C) Hans-Joachim Hetscher DD8NE (dd8ne@bnv-bamberg.de)
* Copyright (C) Hans Alblas PE1AYX (hans@esrac.ele.tue.nl)
* Copyright (C) Frederic Rible F1OAT (frible@teaser.fr)
*/
#include <linux/capability.h>
#include <linux/module.h>
#include <linux/errno.h>
#include <linux/types.h>
#include <linux/socket.h>
#include <linux/in.h>
#include <linux/kernel.h>
#include <linux/sched/signal.h>
#include <linux/timer.h>
#include <linux/string.h>
#include <linux/sockios.h>
#include <linux/net.h>
#include <linux/slab.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 <linux/uaccess.h>
#include <linux/fcntl.h>
#include <linux/termios.h> /* For TIOCINQ/OUTQ */
#include <linux/mm.h>
#include <linux/interrupt.h>
#include <linux/notifier.h>
#include <linux/proc_fs.h>
#include <linux/stat.h>
#include <linux/sysctl.h>
#include <linux/init.h>
#include <linux/spinlock.h>
#include <net/net_namespace.h>
#include <net/tcp_states.h>
#include <net/ip.h>
#include <net/arp.h>
HLIST_HEAD(ax25_list);
DEFINE_SPINLOCK(ax25_list_lock);
static const struct proto_ops ax25_proto_ops;
static void ax25_free_sock(struct sock *sk)
{
ax25_cb_put(sk_to_ax25(sk));
}
/*
* Socket removal during an interrupt is now safe.
*/
static void ax25_cb_del(ax25_cb *ax25)
{
spin_lock_bh(&ax25_list_lock);
if (!hlist_unhashed(&ax25->ax25_node)) {
hlist_del_init(&ax25->ax25_node);
ax25_cb_put(ax25);
}
spin_unlock_bh(&ax25_list_lock);
}
/*
* Kill all bound sockets on a dropped device.
*/
static void ax25_kill_by_device(struct net_device *dev)
{
ax25_dev *ax25_dev;
ax25_cb *s;
struct sock *sk;
if ((ax25_dev = ax25_dev_ax25dev(dev)) == NULL)
return;
ax25_dev->device_up = false;
spin_lock_bh(&ax25_list_lock);
again:
ax25_for_each(s, &ax25_list) {
if (s->ax25_dev == ax25_dev) {
sk = s->sk;
if (!sk) {
spin_unlock_bh(&ax25_list_lock);
ax25_disconnect(s, ENETUNREACH);
s->ax25_dev = NULL;
ax25_cb_del(s);
spin_lock_bh(&ax25_list_lock);
goto again;
}
sock_hold(sk);
spin_unlock_bh(&ax25_list_lock);
lock_sock(sk);
ax25_disconnect(s, ENETUNREACH);
s->ax25_dev = NULL;
if (sk->sk_socket) {
netdev_put(ax25_dev->dev,
&s->dev_tracker);
ax25_dev_put(ax25_dev);
}
ax25_cb_del(s);
release_sock(sk);
spin_lock_bh(&ax25_list_lock);
sock_put(sk);
/* The entry could have been deleted from the
* list meanwhile and thus the next pointer is
* no longer valid. Play it safe and restart
* the scan. Forward progress is ensured
* because we set s->ax25_dev to NULL and we
* are never passed a NULL 'dev' argument.
*/
goto again;
}
}
spin_unlock_bh(&ax25_list_lock);
}
/*
* Handle device status changes.
*/
static int ax25_device_event(struct notifier_block *this, unsigned long event,
void *ptr)
{
struct net_device *dev = netdev_notifier_info_to_dev(ptr);
if (!net_eq(dev_net(dev), &init_net))
return NOTIFY_DONE;
/* Reject non AX.25 devices */
if (dev->type != ARPHRD_AX25)
return NOTIFY_DONE;
switch (event) {
case NETDEV_UP:
ax25_dev_device_up(dev);
break;
case NETDEV_DOWN:
ax25_kill_by_device(dev);
ax25_rt_device_down(dev);
ax25_dev_device_down(dev);
break;
default:
break;
}
return NOTIFY_DONE;
}
/*
* Add a socket to the bound sockets list.
*/
void ax25_cb_add(ax25_cb *ax25)
{
spin_lock_bh(&ax25_list_lock);
ax25_cb_hold(ax25);
hlist_add_head(&ax25->ax25_node, &ax25_list);
spin_unlock_bh(&ax25_list_lock);
}
/*
* Find a socket that wants to accept the SABM we have just
* received.
*/
struct sock *ax25_find_listener(ax25_address *addr, int digi,
struct net_device *dev, int type)
{
ax25_cb *s;
spin_lock(&ax25_list_lock);
ax25_for_each(s, &ax25_list) {
if ((s->iamdigi && !digi) || (!s->iamdigi && digi))
continue;
if (s->sk && !ax25cmp(&s->source_addr, addr) &&
s->sk->sk_type == type && s->sk->sk_state == TCP_LISTEN) {
/* If device is null we match any device */
if (s->ax25_dev == NULL || s->ax25_dev->dev == dev) {
sock_hold(s->sk);
spin_unlock(&ax25_list_lock);
return s->sk;
}
}
}
spin_unlock(&ax25_list_lock);
return NULL;
}
/*
* Find an AX.25 socket given both ends.
*/
struct sock *ax25_get_socket(ax25_address *my_addr, ax25_address *dest_addr,
int type)
{
struct sock *sk = NULL;
ax25_cb *s;
spin_lock(&ax25_list_lock);
ax25_for_each(s, &ax25_list) {
if (s->sk && !ax25cmp(&s->source_addr, my_addr) &&
!ax25cmp(&s->dest_addr, dest_addr) &&
s->sk->sk_type == type) {
sk = s->sk;
sock_hold(sk);
break;
}
}
spin_unlock(&ax25_list_lock);
return sk;
}
/*
* Find an AX.25 control block given both ends. It will only pick up
* floating AX.25 control blocks or non Raw socket bound control blocks.
*/
ax25_cb *ax25_find_cb(const ax25_address *src_addr, ax25_address *dest_addr,
ax25_digi *digi, struct net_device *dev)
{
ax25_cb *s;
spin_lock_bh(&ax25_list_lock);
ax25_for_each(s, &ax25_list) {
if (s->sk && s->sk->sk_type != SOCK_SEQPACKET)
continue;
if (s->ax25_dev == NULL)
continue;
if (ax25cmp(&s->source_addr, src_addr) == 0 && ax25cmp(&s->dest_addr, dest_addr) == 0 && s->ax25_dev->dev == dev) {
if (digi != NULL && digi->ndigi != 0) {
if (s->digipeat == NULL)
continue;
if (ax25digicmp(s->digipeat, digi) != 0)
continue;
} else {
if (s->digipeat != NULL && s->digipeat->ndigi != 0)
continue;
}
ax25_cb_hold(s);
spin_unlock_bh(&ax25_list_lock);
return s;
}
}
spin_unlock_bh(&ax25_list_lock);
return NULL;
}
EXPORT_SYMBOL(ax25_find_cb);
void ax25_send_to_raw(ax25_address *addr, struct sk_buff *skb, int proto)
{
ax25_cb *s;
struct sk_buff *copy;
spin_lock(&ax25_list_lock);
ax25_for_each(s, &ax25_list) {
if (s->sk != NULL && ax25cmp(&s->source_addr, addr) == 0 &&
s->sk->sk_type == SOCK_RAW &&
s->sk->sk_protocol == proto &&
s->ax25_dev->dev == skb->dev &&
atomic_read(&s->sk->sk_rmem_alloc) <= s->sk->sk_rcvbuf) {
if ((copy = skb_clone(skb, GFP_ATOMIC)) == NULL)
continue;
if (sock_queue_rcv_skb(s->sk, copy) != 0)
kfree_skb(copy);
}
}
spin_unlock(&ax25_list_lock);
}
/*
* Deferred destroy.
*/
void ax25_destroy_socket(ax25_cb *);
/*
* Handler for deferred kills.
*/
static void ax25_destroy_timer(struct timer_list *t)
{
ax25_cb *ax25 = from_timer(ax25, t, dtimer);
struct sock *sk;
sk=ax25->sk;
bh_lock_sock(sk);
sock_hold(sk);
ax25_destroy_socket(ax25);
bh_unlock_sock(sk);
sock_put(sk);
}
/*
* This is called from user mode and the timers. Thus it protects itself
* against interrupt users but doesn't worry about being called during
* work. Once it is removed from the queue no interrupt or bottom half
* will touch it and we are (fairly 8-) ) safe.
*/
void ax25_destroy_socket(ax25_cb *ax25)
{
struct sk_buff *skb;
ax25_cb_del(ax25);
ax25_stop_heartbeat(ax25);
ax25_stop_t1timer(ax25);
ax25_stop_t2timer(ax25);
ax25_stop_t3timer(ax25);
ax25_stop_idletimer(ax25);
ax25_clear_queues(ax25); /* Flush the queues */
if (ax25->sk != NULL) {
while ((skb = skb_dequeue(&ax25->sk->sk_receive_queue)) != NULL) {
if (skb->sk != ax25->sk) {
/* A pending connection */
ax25_cb *sax25 = sk_to_ax25(skb->sk);
/* Queue the unaccepted socket for death */
sock_orphan(skb->sk);
/* 9A4GL: hack to release unaccepted sockets */
skb->sk->sk_state = TCP_LISTEN;
ax25_start_heartbeat(sax25);
sax25->state = AX25_STATE_0;
}
kfree_skb(skb);
}
skb_queue_purge(&ax25->sk->sk_write_queue);
}
if (ax25->sk != NULL) {
if (sk_has_allocations(ax25->sk)) {
/* Defer: outstanding buffers */
timer_setup(&ax25->dtimer, ax25_destroy_timer, 0);
ax25->dtimer.expires = jiffies + 2 * HZ;
add_timer(&ax25->dtimer);
} else {
struct sock *sk=ax25->sk;
ax25->sk=NULL;
sock_put(sk);
}
} else {
ax25_cb_put(ax25);
}
}
/*
* dl1bke 960311: set parameters for existing AX.25 connections,
* includes a KILL command to abort any connection.
* VERY useful for debugging ;-)
*/
static int ax25_ctl_ioctl(const unsigned int cmd, void __user *arg)
{
struct ax25_ctl_struct ax25_ctl;
ax25_digi digi;
ax25_dev *ax25_dev;
ax25_cb *ax25;
unsigned int k;
int ret = 0;
if (copy_from_user(&ax25_ctl, arg, sizeof(ax25_ctl)))
return -EFAULT;
if (ax25_ctl.digi_count > AX25_MAX_DIGIS)
return -EINVAL;
if (ax25_ctl.arg > ULONG_MAX / HZ && ax25_ctl.cmd != AX25_KILL)
return -EINVAL;
ax25_dev = ax25_addr_ax25dev(&ax25_ctl.port_addr);
if (!ax25_dev)
return -ENODEV;
digi.ndigi = ax25_ctl.digi_count;
for (k = 0; k < digi.ndigi; k++)
digi.calls[k] = ax25_ctl.digi_addr[k];
ax25 = ax25_find_cb(&ax25_ctl.source_addr, &ax25_ctl.dest_addr, &digi, ax25_dev->dev);
if (!ax25) {
ax25_dev_put(ax25_dev);
return -ENOTCONN;
}
switch (ax25_ctl.cmd) {
case AX25_KILL:
ax25_send_control(ax25, AX25_DISC, AX25_POLLON, AX25_COMMAND);
#ifdef CONFIG_AX25_DAMA_SLAVE
if (ax25_dev->dama.slave && ax25->ax25_dev->values[AX25_VALUES_PROTOCOL] == AX25_PROTO_DAMA_SLAVE)
ax25_dama_off(ax25);
#endif
ax25_disconnect(ax25, ENETRESET);
break;
case AX25_WINDOW:
if (ax25->modulus == AX25_MODULUS) {
if (ax25_ctl.arg < 1 || ax25_ctl.arg > 7)
goto einval_put;
} else {
if (ax25_ctl.arg < 1 || ax25_ctl.arg > 63)
goto einval_put;
}
ax25->window = ax25_ctl.arg;
break;
case AX25_T1:
if (ax25_ctl.arg < 1 || ax25_ctl.arg > ULONG_MAX / HZ)
goto einval_put;
ax25->rtt = (ax25_ctl.arg * HZ) / 2;
ax25->t1 = ax25_ctl.arg * HZ;
break;
case AX25_T2:
if (ax25_ctl.arg < 1 || ax25_ctl.arg > ULONG_MAX / HZ)
goto einval_put;
ax25->t2 = ax25_ctl.arg * HZ;
break;
case AX25_N2:
if (ax25_ctl.arg < 1 || ax25_ctl.arg > 31)
goto einval_put;
ax25->n2count = 0;
ax25->n2 = ax25_ctl.arg;
break;
case AX25_T3:
if (ax25_ctl.arg > ULONG_MAX / HZ)
goto einval_put;
ax25->t3 = ax25_ctl.arg * HZ;
break;
case AX25_IDLE:
if (ax25_ctl.arg > ULONG_MAX / (60 * HZ))
goto einval_put;
ax25->idle = ax25_ctl.arg * 60 * HZ;
break;
case AX25_PACLEN:
if (ax25_ctl.arg < 16 || ax25_ctl.arg > 65535)
goto einval_put;
ax25->paclen = ax25_ctl.arg;
break;
default:
goto einval_put;
}
out_put:
ax25_dev_put(ax25_dev);
ax25_cb_put(ax25);
return ret;
einval_put:
ret = -EINVAL;
goto out_put;
}
static void ax25_fillin_cb_from_dev(ax25_cb *ax25, ax25_dev *ax25_dev)
{
ax25->rtt = msecs_to_jiffies(ax25_dev->values[AX25_VALUES_T1]) / 2;
ax25->t1 = msecs_to_jiffies(ax25_dev->values[AX25_VALUES_T1]);
ax25->t2 = msecs_to_jiffies(ax25_dev->values[AX25_VALUES_T2]);
ax25->t3 = msecs_to_jiffies(ax25_dev->values[AX25_VALUES_T3]);
ax25->n2 = ax25_dev->values[AX25_VALUES_N2];
ax25->paclen = ax25_dev->values[AX25_VALUES_PACLEN];
ax25->idle = msecs_to_jiffies(ax25_dev->values[AX25_VALUES_IDLE]);
ax25->backoff = ax25_dev->values[AX25_VALUES_BACKOFF];
if (ax25_dev->values[AX25_VALUES_AXDEFMODE]) {
ax25->modulus = AX25_EMODULUS;
ax25->window = ax25_dev->values[AX25_VALUES_EWINDOW];
} else {
ax25->modulus = AX25_MODULUS;
ax25->window = ax25_dev->values[AX25_VALUES_WINDOW];
}
}
/*
* Fill in a created AX.25 created control block with the default
* values for a particular device.
*/
void ax25_fillin_cb(ax25_cb *ax25, ax25_dev *ax25_dev)
{
ax25->ax25_dev = ax25_dev;
if (ax25->ax25_dev != NULL) {
ax25_fillin_cb_from_dev(ax25, ax25_dev);
return;
}
/*
* No device, use kernel / AX.25 spec default values
*/
ax25->rtt = msecs_to_jiffies(AX25_DEF_T1) / 2;
ax25->t1 = msecs_to_jiffies(AX25_DEF_T1);
ax25->t2 = msecs_to_jiffies(AX25_DEF_T2);
ax25->t3 = msecs_to_jiffies(AX25_DEF_T3);
ax25->n2 = AX25_DEF_N2;
ax25->paclen = AX25_DEF_PACLEN;
ax25->idle = msecs_to_jiffies(AX25_DEF_IDLE);
ax25->backoff = AX25_DEF_BACKOFF;
if (AX25_DEF_AXDEFMODE) {
ax25->modulus = AX25_EMODULUS;
ax25->window = AX25_DEF_EWINDOW;
} else {
ax25->modulus = AX25_MODULUS;
ax25->window = AX25_DEF_WINDOW;
}
}
/*
* Create an empty AX.25 control block.
*/
ax25_cb *ax25_create_cb(void)
{
ax25_cb *ax25;
if ((ax25 = kzalloc(sizeof(*ax25), GFP_ATOMIC)) == NULL)
return NULL;
refcount_set(&ax25->refcount, 1);
skb_queue_head_init(&ax25->write_queue);
skb_queue_head_init(&ax25->frag_queue);
skb_queue_head_init(&ax25->ack_queue);
skb_queue_head_init(&ax25->reseq_queue);
ax25_setup_timers(ax25);
ax25_fillin_cb(ax25, NULL);
ax25->state = AX25_STATE_0;
return ax25;
}
/*
* Handling for system calls applied via the various interfaces to an
* AX25 socket object
*/
static int ax25_setsockopt(struct socket *sock, int level, int optname,
sockptr_t optval, unsigned int optlen)
{
struct sock *sk = sock->sk;
ax25_cb *ax25;
struct net_device *dev;
char devname[IFNAMSIZ];
unsigned int opt;
int res = 0;
if (level != SOL_AX25)
return -ENOPROTOOPT;
if (optlen < sizeof(unsigned int))
return -EINVAL;
if (copy_from_sockptr(&opt, optval, sizeof(unsigned int)))
return -EFAULT;
lock_sock(sk);
ax25 = sk_to_ax25(sk);
switch (optname) {
case AX25_WINDOW:
if (ax25->modulus == AX25_MODULUS) {
if (opt < 1 || opt > 7) {
res = -EINVAL;
break;
}
} else {
if (opt < 1 || opt > 63) {
res = -EINVAL;
break;
}
}
ax25->window = opt;
break;
case AX25_T1:
if (opt < 1 || opt > UINT_MAX / HZ) {
res = -EINVAL;
break;
}
ax25->rtt = (opt * HZ) >> 1;
ax25->t1 = opt * HZ;
break;
case AX25_T2:
if (opt < 1 || opt > UINT_MAX / HZ) {
res = -EINVAL;
break;
}
ax25->t2 = opt * HZ;
break;
case AX25_N2:
if (opt < 1 || opt > 31) {
res = -EINVAL;
break;
}
ax25->n2 = opt;
break;
case AX25_T3:
if (opt < 1 || opt > UINT_MAX / HZ) {
res = -EINVAL;
break;
}
ax25->t3 = opt * HZ;
break;
case AX25_IDLE:
if (opt > UINT_MAX / (60 * HZ)) {
res = -EINVAL;
break;
}
ax25->idle = opt * 60 * HZ;
break;
case AX25_BACKOFF:
if (opt > 2) {
res = -EINVAL;
break;
}
ax25->backoff = opt;
break;
case AX25_EXTSEQ:
ax25->modulus = opt ? AX25_EMODULUS : AX25_MODULUS;
break;
case AX25_PIDINCL:
ax25->pidincl = opt ? 1 : 0;
break;
case AX25_IAMDIGI:
ax25->iamdigi = opt ? 1 : 0;
break;
case AX25_PACLEN:
if (opt < 16 || opt > 65535) {
res = -EINVAL;
break;
}
ax25->paclen = opt;
break;
case SO_BINDTODEVICE:
if (optlen > IFNAMSIZ - 1)
optlen = IFNAMSIZ - 1;
memset(devname, 0, sizeof(devname));
if (copy_from_sockptr(devname, optval, optlen)) {
res = -EFAULT;
break;
}
if (sk->sk_type == SOCK_SEQPACKET &&
(sock->state != SS_UNCONNECTED ||
sk->sk_state == TCP_LISTEN)) {
res = -EADDRNOTAVAIL;
break;
}
rtnl_lock();
dev = __dev_get_by_name(&init_net, devname);
if (!dev) {
rtnl_unlock();
res = -ENODEV;
break;
}
ax25->ax25_dev = ax25_dev_ax25dev(dev);
if (!ax25->ax25_dev) {
rtnl_unlock();
res = -ENODEV;
break;
}
ax25_fillin_cb(ax25, ax25->ax25_dev);
rtnl_unlock();
break;
default:
res = -ENOPROTOOPT;
}
release_sock(sk);
return res;
}
static int ax25_getsockopt(struct socket *sock, int level, int optname,
char __user *optval, int __user *optlen)
{
struct sock *sk = sock->sk;
ax25_cb *ax25;
struct ax25_dev *ax25_dev;
char devname[IFNAMSIZ];
void *valptr;
int val = 0;
int maxlen, length;
if (level != SOL_AX25)
return -ENOPROTOOPT;
if (get_user(maxlen, optlen))
return -EFAULT;
if (maxlen < 1)
return -EFAULT;
valptr = &val;
length = min_t(unsigned int, maxlen, sizeof(int));
lock_sock(sk);
ax25 = sk_to_ax25(sk);
switch (optname) {
case AX25_WINDOW:
val = ax25->window;
break;
case AX25_T1:
val = ax25->t1 / HZ;
break;
case AX25_T2:
val = ax25->t2 / HZ;
break;
case AX25_N2:
val = ax25->n2;
break;
case AX25_T3:
val = ax25->t3 / HZ;
break;
case AX25_IDLE:
val = ax25->idle / (60 * HZ);
break;
case AX25_BACKOFF:
val = ax25->backoff;
break;
case AX25_EXTSEQ:
val = (ax25->modulus == AX25_EMODULUS);
break;
case AX25_PIDINCL:
val = ax25->pidincl;
break;
case AX25_IAMDIGI:
val = ax25->iamdigi;
break;
case AX25_PACLEN:
val = ax25->paclen;
break;
case SO_BINDTODEVICE:
ax25_dev = ax25->ax25_dev;
if (ax25_dev != NULL && ax25_dev->dev != NULL) {
strscpy(devname, ax25_dev->dev->name, sizeof(devname));
length = strlen(devname) + 1;
} else {
*devname = '\0';
length = 1;
}
valptr = devname;
break;
default:
release_sock(sk);
return -ENOPROTOOPT;
}
release_sock(sk);
if (put_user(length, optlen))
return -EFAULT;
return copy_to_user(optval, valptr, length) ? -EFAULT : 0;
}
static int ax25_listen(struct socket *sock, int backlog)
{
struct sock *sk = sock->sk;
int res = 0;
lock_sock(sk);
if (sk->sk_type == SOCK_SEQPACKET && sk->sk_state != TCP_LISTEN) {
sk->sk_max_ack_backlog = backlog;
sk->sk_state = TCP_LISTEN;
goto out;
}
res = -EOPNOTSUPP;
out:
release_sock(sk);
return res;
}
/*
* XXX: when creating ax25_sock we should update the .obj_size setting
* below.
*/
static struct proto ax25_proto = {
.name = "AX25",
.owner = THIS_MODULE,
.obj_size = sizeof(struct ax25_sock),
};
static int ax25_create(struct net *net, struct socket *sock, int protocol,
int kern)
{
struct sock *sk;
ax25_cb *ax25;
if (protocol < 0 || protocol > U8_MAX)
return -EINVAL;
if (!net_eq(net, &init_net))
return -EAFNOSUPPORT;
switch (sock->type) {
case SOCK_DGRAM:
if (protocol == 0 || protocol == PF_AX25)
protocol = AX25_P_TEXT;
break;
case SOCK_SEQPACKET:
switch (protocol) {
case 0:
case PF_AX25: /* For CLX */
protocol = AX25_P_TEXT;
break;
case AX25_P_SEGMENT:
#ifdef CONFIG_INET
case AX25_P_ARP:
case AX25_P_IP:
#endif
#ifdef CONFIG_NETROM
case AX25_P_NETROM:
#endif
#ifdef CONFIG_ROSE
case AX25_P_ROSE:
#endif
return -ESOCKTNOSUPPORT;
#ifdef CONFIG_NETROM_MODULE
case AX25_P_NETROM:
if (ax25_protocol_is_registered(AX25_P_NETROM))
return -ESOCKTNOSUPPORT;
break;
#endif
#ifdef CONFIG_ROSE_MODULE
case AX25_P_ROSE:
if (ax25_protocol_is_registered(AX25_P_ROSE))
return -ESOCKTNOSUPPORT;
break;
#endif
default:
break;
}
break;
case SOCK_RAW:
if (!capable(CAP_NET_RAW))
return -EPERM;
break;
default:
return -ESOCKTNOSUPPORT;
}
sk = sk_alloc(net, PF_AX25, GFP_ATOMIC, &ax25_proto, kern);
if (sk == NULL)
return -ENOMEM;
ax25 = ax25_sk(sk)->cb = ax25_create_cb();
if (!ax25) {
sk_free(sk);
return -ENOMEM;
}
sock_init_data(sock, sk);
sk->sk_destruct = ax25_free_sock;
sock->ops = &ax25_proto_ops;
sk->sk_protocol = protocol;
ax25->sk = sk;
return 0;
}
struct sock *ax25_make_new(struct sock *osk, struct ax25_dev *ax25_dev)
{
struct sock *sk;
ax25_cb *ax25, *oax25;
sk = sk_alloc(sock_net(osk), PF_AX25, GFP_ATOMIC, osk->sk_prot, 0);
if (sk == NULL)
return NULL;
if ((ax25 = ax25_create_cb()) == NULL) {
sk_free(sk);
return NULL;
}
switch (osk->sk_type) {
case SOCK_DGRAM:
break;
case SOCK_SEQPACKET:
break;
default:
sk_free(sk);
ax25_cb_put(ax25);
return NULL;
}
sock_init_data(NULL, sk);
sk->sk_type = osk->sk_type;
sk->sk_priority = READ_ONCE(osk->sk_priority);
sk->sk_protocol = osk->sk_protocol;
sk->sk_rcvbuf = osk->sk_rcvbuf;
sk->sk_sndbuf = osk->sk_sndbuf;
sk->sk_state = TCP_ESTABLISHED;
sock_copy_flags(sk, osk);
oax25 = sk_to_ax25(osk);
ax25->modulus = oax25->modulus;
ax25->backoff = oax25->backoff;
ax25->pidincl = oax25->pidincl;
ax25->iamdigi = oax25->iamdigi;
ax25->rtt = oax25->rtt;
ax25->t1 = oax25->t1;
ax25->t2 = oax25->t2;
ax25->t3 = oax25->t3;
ax25->n2 = oax25->n2;
ax25->idle = oax25->idle;
ax25->paclen = oax25->paclen;
ax25->window = oax25->window;
ax25->ax25_dev = ax25_dev;
ax25->source_addr = oax25->source_addr;
if (oax25->digipeat != NULL) {
ax25->digipeat = kmemdup(oax25->digipeat, sizeof(ax25_digi),
GFP_ATOMIC);
if (ax25->digipeat == NULL) {
sk_free(sk);
ax25_cb_put(ax25);
return NULL;
}
}
ax25_sk(sk)->cb = ax25;
sk->sk_destruct = ax25_free_sock;
ax25->sk = sk;
return sk;
}
static int ax25_release(struct socket *sock)
{
struct sock *sk = sock->sk;
ax25_cb *ax25;
ax25_dev *ax25_dev;
if (sk == NULL)
return 0;
sock_hold(sk);
lock_sock(sk);
sock_orphan(sk);
ax25 = sk_to_ax25(sk);
ax25_dev = ax25->ax25_dev;
if (sk->sk_type == SOCK_SEQPACKET) {
switch (ax25->state) {
case AX25_STATE_0:
if (!sock_flag(ax25->sk, SOCK_DEAD)) {
release_sock(sk);
ax25_disconnect(ax25, 0);
lock_sock(sk);
}
ax25_destroy_socket(ax25);
break;
case AX25_STATE_1:
case AX25_STATE_2:
ax25_send_control(ax25, AX25_DISC, AX25_POLLON, AX25_COMMAND);
release_sock(sk);
ax25_disconnect(ax25, 0);
lock_sock(sk);
if (!sock_flag(ax25->sk, SOCK_DESTROY))
ax25_destroy_socket(ax25);
break;
case AX25_STATE_3:
case AX25_STATE_4:
ax25_clear_queues(ax25);
ax25->n2count = 0;
switch (ax25->ax25_dev->values[AX25_VALUES_PROTOCOL]) {
case AX25_PROTO_STD_SIMPLEX:
case AX25_PROTO_STD_DUPLEX:
ax25_send_control(ax25,
AX25_DISC,
AX25_POLLON,
AX25_COMMAND);
ax25_stop_t2timer(ax25);
ax25_stop_t3timer(ax25);
ax25_stop_idletimer(ax25);
break;
#ifdef CONFIG_AX25_DAMA_SLAVE
case AX25_PROTO_DAMA_SLAVE:
ax25_stop_t3timer(ax25);
ax25_stop_idletimer(ax25);
break;
#endif
}
ax25_calculate_t1(ax25);
ax25_start_t1timer(ax25);
ax25->state = AX25_STATE_2;
sk->sk_state = TCP_CLOSE;
sk->sk_shutdown |= SEND_SHUTDOWN;
sk->sk_state_change(sk);
sock_set_flag(sk, SOCK_DESTROY);
break;
default:
break;
}
} else {
sk->sk_state = TCP_CLOSE;
sk->sk_shutdown |= SEND_SHUTDOWN;
sk->sk_state_change(sk);
ax25_destroy_socket(ax25);
}
if (ax25_dev) {
if (!ax25_dev->device_up) {
del_timer_sync(&ax25->timer);
del_timer_sync(&ax25->t1timer);
del_timer_sync(&ax25->t2timer);
del_timer_sync(&ax25->t3timer);
del_timer_sync(&ax25->idletimer);
}
netdev_put(ax25_dev->dev, &ax25->dev_tracker);
ax25_dev_put(ax25_dev);
}
sock->sk = NULL;
release_sock(sk);
sock_put(sk);
return 0;
}
/*
* We support a funny extension here so you can (as root) give any callsign
* digipeated via a local address as source. This hack is obsolete now
* that we've implemented support for SO_BINDTODEVICE. It is however small
* and trivially backward compatible.
*/
static int ax25_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
{
struct sock *sk = sock->sk;
struct full_sockaddr_ax25 *addr = (struct full_sockaddr_ax25 *)uaddr;
ax25_dev *ax25_dev = NULL;
ax25_uid_assoc *user;
ax25_address call;
ax25_cb *ax25;
int err = 0;
if (addr_len != sizeof(struct sockaddr_ax25) &&
addr_len != sizeof(struct full_sockaddr_ax25))
/* support for old structure may go away some time
* ax25_bind(): uses old (6 digipeater) socket structure.
*/
if ((addr_len < sizeof(struct sockaddr_ax25) + sizeof(ax25_address) * 6) ||
(addr_len > sizeof(struct full_sockaddr_ax25)))
return -EINVAL;
if (addr->fsa_ax25.sax25_family != AF_AX25)
return -EINVAL;
user = ax25_findbyuid(current_euid());
if (user) {
call = user->call;
ax25_uid_put(user);
} else {
if (ax25_uid_policy && !capable(CAP_NET_ADMIN))
return -EACCES;
call = addr->fsa_ax25.sax25_call;
}
lock_sock(sk);
ax25 = sk_to_ax25(sk);
if (!sock_flag(sk, SOCK_ZAPPED)) {
err = -EINVAL;
goto out;
}
ax25->source_addr = call;
/*
* User already set interface with SO_BINDTODEVICE
*/
if (ax25->ax25_dev != NULL)
goto done;
if (addr_len > sizeof(struct sockaddr_ax25) && addr->fsa_ax25.sax25_ndigis == 1) {
if (ax25cmp(&addr->fsa_digipeater[0], &null_ax25_address) != 0 &&
(ax25_dev = ax25_addr_ax25dev(&addr->fsa_digipeater[0])) == NULL) {
err = -EADDRNOTAVAIL;
goto out;
}
} else {
if ((ax25_dev = ax25_addr_ax25dev(&addr->fsa_ax25.sax25_call)) == NULL) {
err = -EADDRNOTAVAIL;
goto out;
}
}
if (ax25_dev) {
ax25_fillin_cb(ax25, ax25_dev);
netdev_hold(ax25_dev->dev, &ax25->dev_tracker, GFP_ATOMIC);
}
done:
ax25_cb_add(ax25);
sock_reset_flag(sk, SOCK_ZAPPED);
out:
release_sock(sk);
return err;
}
/*
* FIXME: nonblock behaviour looks like it may have a bug.
*/
static int __must_check ax25_connect(struct socket *sock,
struct sockaddr *uaddr, int addr_len, int flags)
{
struct sock *sk = sock->sk;
ax25_cb *ax25 = sk_to_ax25(sk), *ax25t;
struct full_sockaddr_ax25 *fsa = (struct full_sockaddr_ax25 *)uaddr;
ax25_digi *digi = NULL;
int ct = 0, err = 0;
/*
* some sanity checks. code further down depends on this
*/
if (addr_len == sizeof(struct sockaddr_ax25))
/* support for this will go away in early 2.5.x
* ax25_connect(): uses obsolete socket structure
*/
;
else if (addr_len != sizeof(struct full_sockaddr_ax25))
/* support for old structure may go away some time
* ax25_connect(): uses old (6 digipeater) socket structure.
*/
if ((addr_len < sizeof(struct sockaddr_ax25) + sizeof(ax25_address) * 6) ||
(addr_len > sizeof(struct full_sockaddr_ax25)))
return -EINVAL;
if (fsa->fsa_ax25.sax25_family != AF_AX25)
return -EINVAL;
lock_sock(sk);
/* deal with restarts */
if (sock->state == SS_CONNECTING) {
switch (sk->sk_state) {
case TCP_SYN_SENT: /* still trying */
err = -EINPROGRESS;
goto out_release;
case TCP_ESTABLISHED: /* connection established */
sock->state = SS_CONNECTED;
goto out_release;
case TCP_CLOSE: /* connection refused */
sock->state = SS_UNCONNECTED;
err = -ECONNREFUSED;
goto out_release;
}
}
if (sk->sk_state == TCP_ESTABLISHED && sk->sk_type == SOCK_SEQPACKET) {
err = -EISCONN; /* No reconnect on a seqpacket socket */
goto out_release;
}
sk->sk_state = TCP_CLOSE;
sock->state = SS_UNCONNECTED;
kfree(ax25->digipeat);
ax25->digipeat = NULL;
/*
* Handle digi-peaters to be used.
*/
if (addr_len > sizeof(struct sockaddr_ax25) &&
fsa->fsa_ax25.sax25_ndigis != 0) {
/* Valid number of digipeaters ? */
if (fsa->fsa_ax25.sax25_ndigis < 1 ||
fsa->fsa_ax25.sax25_ndigis > AX25_MAX_DIGIS ||
addr_len < sizeof(struct sockaddr_ax25) +
sizeof(ax25_address) * fsa->fsa_ax25.sax25_ndigis) {
err = -EINVAL;
goto out_release;
}
if ((digi = kmalloc(sizeof(ax25_digi), GFP_KERNEL)) == NULL) {
err = -ENOBUFS;
goto out_release;
}
digi->ndigi = fsa->fsa_ax25.sax25_ndigis;
digi->lastrepeat = -1;
while (ct < fsa->fsa_ax25.sax25_ndigis) {
if ((fsa->fsa_digipeater[ct].ax25_call[6] &
AX25_HBIT) && ax25->iamdigi) {
digi->repeated[ct] = 1;
digi->lastrepeat = ct;
} else {
digi->repeated[ct] = 0;
}
digi->calls[ct] = fsa->fsa_digipeater[ct];
ct++;
}
}
/*
* Must bind first - autobinding in this may or may not work. If
* the socket is already bound, check to see if the device has
* been filled in, error if it hasn't.
*/
if (sock_flag(sk, SOCK_ZAPPED)) {
/* check if we can remove this feature. It is broken. */
printk(KERN_WARNING "ax25_connect(): %s uses autobind, please contact jreuter@yaina.de\n",
current->comm);
if ((err = ax25_rt_autobind(ax25, &fsa->fsa_ax25.sax25_call)) < 0) {
kfree(digi);
goto out_release;
}
ax25_fillin_cb(ax25, ax25->ax25_dev);
ax25_cb_add(ax25);
} else {
if (ax25->ax25_dev == NULL) {
kfree(digi);
err = -EHOSTUNREACH;
goto out_release;
}
}
if (sk->sk_type == SOCK_SEQPACKET &&
(ax25t=ax25_find_cb(&ax25->source_addr, &fsa->fsa_ax25.sax25_call, digi,
ax25->ax25_dev->dev))) {
kfree(digi);
err = -EADDRINUSE; /* Already such a connection */
ax25_cb_put(ax25t);
goto out_release;
}
ax25->dest_addr = fsa->fsa_ax25.sax25_call;
ax25->digipeat = digi;
/* First the easy one */
if (sk->sk_type != SOCK_SEQPACKET) {
sock->state = SS_CONNECTED;
sk->sk_state = TCP_ESTABLISHED;
goto out_release;
}
/* Move to connecting socket, ax.25 lapb WAIT_UA.. */
sock->state = SS_CONNECTING;
sk->sk_state = TCP_SYN_SENT;
switch (ax25->ax25_dev->values[AX25_VALUES_PROTOCOL]) {
case AX25_PROTO_STD_SIMPLEX:
case AX25_PROTO_STD_DUPLEX:
ax25_std_establish_data_link(ax25);
break;
#ifdef CONFIG_AX25_DAMA_SLAVE
case AX25_PROTO_DAMA_SLAVE:
ax25->modulus = AX25_MODULUS;
ax25->window = ax25->ax25_dev->values[AX25_VALUES_WINDOW];
if (ax25->ax25_dev->dama.slave)
ax25_ds_establish_data_link(ax25);
else
ax25_std_establish_data_link(ax25);
break;
#endif
}
ax25->state = AX25_STATE_1;
ax25_start_heartbeat(ax25);
/* Now the loop */
if (sk->sk_state != TCP_ESTABLISHED && (flags & O_NONBLOCK)) {
err = -EINPROGRESS;
goto out_release;
}
if (sk->sk_state == TCP_SYN_SENT) {
DEFINE_WAIT(wait);
for (;;) {
prepare_to_wait(sk_sleep(sk), &wait,
TASK_INTERRUPTIBLE);
if (sk->sk_state != TCP_SYN_SENT)
break;
if (!signal_pending(current)) {
release_sock(sk);
schedule();
lock_sock(sk);
continue;
}
err = -ERESTARTSYS;
break;
}
finish_wait(sk_sleep(sk), &wait);
if (err)
goto out_release;
}
if (sk->sk_state != TCP_ESTABLISHED) {
/* Not in ABM, not in WAIT_UA -> failed */
sock->state = SS_UNCONNECTED;
err = sock_error(sk); /* Always set at this point */
goto out_release;
}
sock->state = SS_CONNECTED;
err = 0;
out_release:
release_sock(sk);
return err;
}
static int ax25_accept(struct socket *sock, struct socket *newsock,
struct proto_accept_arg *arg)
{
struct sk_buff *skb;
struct sock *newsk;
ax25_dev *ax25_dev;
DEFINE_WAIT(wait);
struct sock *sk;
ax25_cb *ax25;
int err = 0;
if (sock->state != SS_UNCONNECTED)
return -EINVAL;
if ((sk = sock->sk) == NULL)
return -EINVAL;
lock_sock(sk);
if (sk->sk_type != SOCK_SEQPACKET) {
err = -EOPNOTSUPP;
goto out;
}
if (sk->sk_state != TCP_LISTEN) {
err = -EINVAL;
goto out;
}
/*
* The read queue this time is holding sockets ready to use
* hooked into the SABM we saved
*/
for (;;) {
prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
skb = skb_dequeue(&sk->sk_receive_queue);
if (skb)
break;
if (arg->flags & O_NONBLOCK) {
err = -EWOULDBLOCK;
break;
}
if (!signal_pending(current)) {
release_sock(sk);
schedule();
lock_sock(sk);
continue;
}
err = -ERESTARTSYS;
break;
}
finish_wait(sk_sleep(sk), &wait);
if (err)
goto out;
newsk = skb->sk;
sock_graft(newsk, newsock);
/* Now attach up the new socket */
kfree_skb(skb);
sk_acceptq_removed(sk);
newsock->state = SS_CONNECTED;
ax25 = sk_to_ax25(newsk);
ax25_dev = ax25->ax25_dev;
netdev_hold(ax25_dev->dev, &ax25->dev_tracker, GFP_ATOMIC);
ax25_dev_hold(ax25_dev);
out:
release_sock(sk);
return err;
}
static int ax25_getname(struct socket *sock, struct sockaddr *uaddr,
int peer)
{
struct full_sockaddr_ax25 *fsa = (struct full_sockaddr_ax25 *)uaddr;
struct sock *sk = sock->sk;
unsigned char ndigi, i;
ax25_cb *ax25;
int err = 0;
memset(fsa, 0, sizeof(*fsa));
lock_sock(sk);
ax25 = sk_to_ax25(sk);
if (peer != 0) {
if (sk->sk_state != TCP_ESTABLISHED) {
err = -ENOTCONN;
goto out;
}
fsa->fsa_ax25.sax25_family = AF_AX25;
fsa->fsa_ax25.sax25_call = ax25->dest_addr;
if (ax25->digipeat != NULL) {
ndigi = ax25->digipeat->ndigi;
fsa->fsa_ax25.sax25_ndigis = ndigi;
for (i = 0; i < ndigi; i++)
fsa->fsa_digipeater[i] =
ax25->digipeat->calls[i];
}
} else {
fsa->fsa_ax25.sax25_family = AF_AX25;
fsa->fsa_ax25.sax25_call = ax25->source_addr;
fsa->fsa_ax25.sax25_ndigis = 1;
if (ax25->ax25_dev != NULL) {
memcpy(&fsa->fsa_digipeater[0],
ax25->ax25_dev->dev->dev_addr, AX25_ADDR_LEN);
} else {
fsa->fsa_digipeater[0] = null_ax25_address;
}
}
err = sizeof (struct full_sockaddr_ax25);
out:
release_sock(sk);
return err;
}
static int ax25_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
{
DECLARE_SOCKADDR(struct sockaddr_ax25 *, usax, msg->msg_name);
struct sock *sk = sock->sk;
struct sockaddr_ax25 sax;
struct sk_buff *skb;
ax25_digi dtmp, *dp;
ax25_cb *ax25;
size_t size;
int lv, err, addr_len = msg->msg_namelen;
if (msg->msg_flags & ~(MSG_DONTWAIT|MSG_EOR|MSG_CMSG_COMPAT))
return -EINVAL;
lock_sock(sk);
ax25 = sk_to_ax25(sk);
if (sock_flag(sk, SOCK_ZAPPED)) {
err = -EADDRNOTAVAIL;
goto out;
}
if (sk->sk_shutdown & SEND_SHUTDOWN) {
send_sig(SIGPIPE, current, 0);
err = -EPIPE;
goto out;
}
if (ax25->ax25_dev == NULL) {
err = -ENETUNREACH;
goto out;
}
if (len > ax25->ax25_dev->dev->mtu) {
err = -EMSGSIZE;
goto out;
}
if (usax != NULL) {
if (usax->sax25_family != AF_AX25) {
err = -EINVAL;
goto out;
}
if (addr_len == sizeof(struct sockaddr_ax25))
/* ax25_sendmsg(): uses obsolete socket structure */
;
else if (addr_len != sizeof(struct full_sockaddr_ax25))
/* support for old structure may go away some time
* ax25_sendmsg(): uses old (6 digipeater)
* socket structure.
*/
if ((addr_len < sizeof(struct sockaddr_ax25) + sizeof(ax25_address) * 6) ||
(addr_len > sizeof(struct full_sockaddr_ax25))) {
err = -EINVAL;
goto out;
}
if (addr_len > sizeof(struct sockaddr_ax25) && usax->sax25_ndigis != 0) {
int ct = 0;
struct full_sockaddr_ax25 *fsa = (struct full_sockaddr_ax25 *)usax;
/* Valid number of digipeaters ? */
if (usax->sax25_ndigis < 1 ||
usax->sax25_ndigis > AX25_MAX_DIGIS ||
addr_len < sizeof(struct sockaddr_ax25) +
sizeof(ax25_address) * usax->sax25_ndigis) {
err = -EINVAL;
goto out;
}
dtmp.ndigi = usax->sax25_ndigis;
while (ct < usax->sax25_ndigis) {
dtmp.repeated[ct] = 0;
dtmp.calls[ct] = fsa->fsa_digipeater[ct];
ct++;
}
dtmp.lastrepeat = 0;
}
sax = *usax;
if (sk->sk_type == SOCK_SEQPACKET &&
ax25cmp(&ax25->dest_addr, &sax.sax25_call)) {
err = -EISCONN;
goto out;
}
if (usax->sax25_ndigis == 0)
dp = NULL;
else
dp = &dtmp;
} else {
/*
* FIXME: 1003.1g - if the socket is like this because
* it has become closed (not started closed) and is VC
* we ought to SIGPIPE, EPIPE
*/
if (sk->sk_state != TCP_ESTABLISHED) {
err = -ENOTCONN;
goto out;
}
sax.sax25_family = AF_AX25;
sax.sax25_call = ax25->dest_addr;
dp = ax25->digipeat;
}
/* Build a packet */
/* Assume the worst case */
size = len + ax25->ax25_dev->dev->hard_header_len;
skb = sock_alloc_send_skb(sk, size, msg->msg_flags&MSG_DONTWAIT, &err);
if (skb == NULL)
goto out;
skb_reserve(skb, size - len);
/* User data follows immediately after the AX.25 data */
if (memcpy_from_msg(skb_put(skb, len), msg, len)) {
err = -EFAULT;
kfree_skb(skb);
goto out;
}
skb_reset_network_header(skb);
/* Add the PID if one is not supplied by the user in the skb */
if (!ax25->pidincl)
*(u8 *)skb_push(skb, 1) = sk->sk_protocol;
if (sk->sk_type == SOCK_SEQPACKET) {
/* Connected mode sockets go via the LAPB machine */
if (sk->sk_state != TCP_ESTABLISHED) {
kfree_skb(skb);
err = -ENOTCONN;
goto out;
}
/* Shove it onto the queue and kick */
ax25_output(ax25, ax25->paclen, skb);
err = len;
goto out;
}
skb_push(skb, 1 + ax25_addr_size(dp));
/* Building AX.25 Header */
/* Build an AX.25 header */
lv = ax25_addr_build(skb->data, &ax25->source_addr, &sax.sax25_call,
dp, AX25_COMMAND, AX25_MODULUS);
skb_set_transport_header(skb, lv);
*skb_transport_header(skb) = AX25_UI;
/* Datagram frames go straight out of the door as UI */
ax25_queue_xmit(skb, ax25->ax25_dev->dev);
err = len;
out:
release_sock(sk);
return err;
}
static int ax25_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
int flags)
{
struct sock *sk = sock->sk;
struct sk_buff *skb, *last;
struct sk_buff_head *sk_queue;
int copied;
int err = 0;
int off = 0;
long timeo;
lock_sock(sk);
/*
* This works for seqpacket too. The receiver has ordered the
* queue for us! We do one quick check first though
*/
if (sk->sk_type == SOCK_SEQPACKET && sk->sk_state != TCP_ESTABLISHED) {
err = -ENOTCONN;
goto out;
}
/* We need support for non-blocking reads. */
sk_queue = &sk->sk_receive_queue;
skb = __skb_try_recv_datagram(sk, sk_queue, flags, &off, &err, &last);
/* If no packet is available, release_sock(sk) and try again. */
if (!skb) {
if (err != -EAGAIN)
goto out;
release_sock(sk);
timeo = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
while (timeo && !__skb_wait_for_more_packets(sk, sk_queue, &err,
&timeo, last)) {
skb = __skb_try_recv_datagram(sk, sk_queue, flags, &off,
&err, &last);
if (skb)
break;
if (err != -EAGAIN)
goto done;
}
if (!skb)
goto done;
lock_sock(sk);
}
if (!sk_to_ax25(sk)->pidincl)
skb_pull(skb, 1); /* Remove PID */
skb_reset_transport_header(skb);
copied = skb->len;
if (copied > size) {
copied = size;
msg->msg_flags |= MSG_TRUNC;
}
skb_copy_datagram_msg(skb, 0, msg, copied);
if (msg->msg_name) {
ax25_digi digi;
ax25_address src;
const unsigned char *mac = skb_mac_header(skb);
DECLARE_SOCKADDR(struct sockaddr_ax25 *, sax, msg->msg_name);
memset(sax, 0, sizeof(struct full_sockaddr_ax25));
ax25_addr_parse(mac + 1, skb->data - mac - 1, &src, NULL,
&digi, NULL, NULL);
sax->sax25_family = AF_AX25;
/* We set this correctly, even though we may not let the
application know the digi calls further down (because it
did NOT ask to know them). This could get political... **/
sax->sax25_ndigis = digi.ndigi;
sax->sax25_call = src;
if (sax->sax25_ndigis != 0) {
int ct;
struct full_sockaddr_ax25 *fsa = (struct full_sockaddr_ax25 *)sax;
for (ct = 0; ct < digi.ndigi; ct++)
fsa->fsa_digipeater[ct] = digi.calls[ct];
}
msg->msg_namelen = sizeof(struct full_sockaddr_ax25);
}
skb_free_datagram(sk, skb);
err = copied;
out:
release_sock(sk);
done:
return err;
}
static int ax25_shutdown(struct socket *sk, int how)
{
/* FIXME - generate DM and RNR states */
return -EOPNOTSUPP;
}
static int ax25_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
{
struct sock *sk = sock->sk;
void __user *argp = (void __user *)arg;
int res = 0;
lock_sock(sk);
switch (cmd) {
case TIOCOUTQ: {
long amount;
amount = sk->sk_sndbuf - sk_wmem_alloc_get(sk);
if (amount < 0)
amount = 0;
res = put_user(amount, (int __user *)argp);
break;
}
case TIOCINQ: {
struct sk_buff *skb;
long amount = 0L;
/* These two are safe on a single CPU system as only user tasks fiddle here */
if ((skb = skb_peek(&sk->sk_receive_queue)) != NULL)
amount = skb->len;
res = put_user(amount, (int __user *) argp);
break;
}
case SIOCAX25ADDUID: /* Add a uid to the uid/call map table */
case SIOCAX25DELUID: /* Delete a uid from the uid/call map table */
case SIOCAX25GETUID: {
struct sockaddr_ax25 sax25;
if (copy_from_user(&sax25, argp, sizeof(sax25))) {
res = -EFAULT;
break;
}
res = ax25_uid_ioctl(cmd, &sax25);
break;
}
case SIOCAX25NOUID: { /* Set the default policy (default/bar) */
long amount;
if (!capable(CAP_NET_ADMIN)) {
res = -EPERM;
break;
}
if (get_user(amount, (long __user *)argp)) {
res = -EFAULT;
break;
}
if (amount < 0 || amount > AX25_NOUID_BLOCK) {
res = -EINVAL;
break;
}
ax25_uid_policy = amount;
res = 0;
break;
}
case SIOCADDRT:
case SIOCDELRT:
case SIOCAX25OPTRT:
if (!capable(CAP_NET_ADMIN)) {
res = -EPERM;
break;
}
res = ax25_rt_ioctl(cmd, argp);
break;
case SIOCAX25CTLCON:
if (!capable(CAP_NET_ADMIN)) {
res = -EPERM;
break;
}
res = ax25_ctl_ioctl(cmd, argp);
break;
case SIOCAX25GETINFO:
case SIOCAX25GETINFOOLD: {
ax25_cb *ax25 = sk_to_ax25(sk);
struct ax25_info_struct ax25_info;
ax25_info.t1 = ax25->t1 / HZ;
ax25_info.t2 = ax25->t2 / HZ;
ax25_info.t3 = ax25->t3 / HZ;
ax25_info.idle = ax25->idle / (60 * HZ);
ax25_info.n2 = ax25->n2;
ax25_info.t1timer = ax25_display_timer(&ax25->t1timer) / HZ;
ax25_info.t2timer = ax25_display_timer(&ax25->t2timer) / HZ;
ax25_info.t3timer = ax25_display_timer(&ax25->t3timer) / HZ;
ax25_info.idletimer = ax25_display_timer(&ax25->idletimer) / (60 * HZ);
ax25_info.n2count = ax25->n2count;
ax25_info.state = ax25->state;
ax25_info.rcv_q = sk_rmem_alloc_get(sk);
ax25_info.snd_q = sk_wmem_alloc_get(sk);
ax25_info.vs = ax25->vs;
ax25_info.vr = ax25->vr;
ax25_info.va = ax25->va;
ax25_info.vs_max = ax25->vs; /* reserved */
ax25_info.paclen = ax25->paclen;
ax25_info.window = ax25->window;
/* old structure? */
if (cmd == SIOCAX25GETINFOOLD) {
static int warned = 0;
if (!warned) {
printk(KERN_INFO "%s uses old SIOCAX25GETINFO\n",
current->comm);
warned=1;
}
if (copy_to_user(argp, &ax25_info, sizeof(struct ax25_info_struct_deprecated))) {
res = -EFAULT;
break;
}
} else {
if (copy_to_user(argp, &ax25_info, sizeof(struct ax25_info_struct))) {
res = -EINVAL;
break;
}
}
res = 0;
break;
}
case SIOCAX25ADDFWD:
case SIOCAX25DELFWD: {
struct ax25_fwd_struct ax25_fwd;
if (!capable(CAP_NET_ADMIN)) {
res = -EPERM;
break;
}
if (copy_from_user(&ax25_fwd, argp, sizeof(ax25_fwd))) {
res = -EFAULT;
break;
}
res = ax25_fwd_ioctl(cmd, &ax25_fwd);
break;
}
case SIOCGIFADDR:
case SIOCSIFADDR:
case SIOCGIFDSTADDR:
case SIOCSIFDSTADDR:
case SIOCGIFBRDADDR:
case SIOCSIFBRDADDR:
case SIOCGIFNETMASK:
case SIOCSIFNETMASK:
case SIOCGIFMETRIC:
case SIOCSIFMETRIC:
res = -EINVAL;
break;
default:
res = -ENOIOCTLCMD;
break;
}
release_sock(sk);
return res;
}
#ifdef CONFIG_PROC_FS
static void *ax25_info_start(struct seq_file *seq, loff_t *pos)
__acquires(ax25_list_lock)
{
spin_lock_bh(&ax25_list_lock);
return seq_hlist_start(&ax25_list, *pos);
}
static void *ax25_info_next(struct seq_file *seq, void *v, loff_t *pos)
{
return seq_hlist_next(v, &ax25_list, pos);
}
static void ax25_info_stop(struct seq_file *seq, void *v)
__releases(ax25_list_lock)
{
spin_unlock_bh(&ax25_list_lock);
}
static int ax25_info_show(struct seq_file *seq, void *v)
{
ax25_cb *ax25 = hlist_entry(v, struct ax25_cb, ax25_node);
char buf[11];
int k;
/*
* New format:
* magic dev src_addr dest_addr,digi1,digi2,.. st vs vr va t1 t1 t2 t2 t3 t3 idle idle n2 n2 rtt window paclen Snd-Q Rcv-Q inode
*/
seq_printf(seq, "%p %s %s%s ",
ax25,
ax25->ax25_dev == NULL? "???" : ax25->ax25_dev->dev->name,
ax2asc(buf, &ax25->source_addr),
ax25->iamdigi? "*":"");
seq_printf(seq, "%s", ax2asc(buf, &ax25->dest_addr));
for (k=0; (ax25->digipeat != NULL) && (k < ax25->digipeat->ndigi); k++) {
seq_printf(seq, ",%s%s",
ax2asc(buf, &ax25->digipeat->calls[k]),
ax25->digipeat->repeated[k]? "*":"");
}
seq_printf(seq, " %d %d %d %d %lu %lu %lu %lu %lu %lu %lu %lu %d %d %lu %d %d",
ax25->state,
ax25->vs, ax25->vr, ax25->va,
ax25_display_timer(&ax25->t1timer) / HZ, ax25->t1 / HZ,
ax25_display_timer(&ax25->t2timer) / HZ, ax25->t2 / HZ,
ax25_display_timer(&ax25->t3timer) / HZ, ax25->t3 / HZ,
ax25_display_timer(&ax25->idletimer) / (60 * HZ),
ax25->idle / (60 * HZ),
ax25->n2count, ax25->n2,
ax25->rtt / HZ,
ax25->window,
ax25->paclen);
if (ax25->sk != NULL) {
seq_printf(seq, " %d %d %lu\n",
sk_wmem_alloc_get(ax25->sk),
sk_rmem_alloc_get(ax25->sk),
sock_i_ino(ax25->sk));
} else {
seq_puts(seq, " * * *\n");
}
return 0;
}
static const struct seq_operations ax25_info_seqops = {
.start = ax25_info_start,
.next = ax25_info_next,
.stop = ax25_info_stop,
.show = ax25_info_show,
};
#endif
static const struct net_proto_family ax25_family_ops = {
.family = PF_AX25,
.create = ax25_create,
.owner = THIS_MODULE,
};
static const struct proto_ops ax25_proto_ops = {
.family = PF_AX25,
.owner = THIS_MODULE,
.release = ax25_release,
.bind = ax25_bind,
.connect = ax25_connect,
.socketpair = sock_no_socketpair,
.accept = ax25_accept,
.getname = ax25_getname,
.poll = datagram_poll,
.ioctl = ax25_ioctl,
.gettstamp = sock_gettstamp,
.listen = ax25_listen,
.shutdown = ax25_shutdown,
.setsockopt = ax25_setsockopt,
.getsockopt = ax25_getsockopt,
.sendmsg = ax25_sendmsg,
.recvmsg = ax25_recvmsg,
.mmap = sock_no_mmap,
};
/*
* Called by socket.c on kernel start up
*/
static struct packet_type ax25_packet_type __read_mostly = {
.type = cpu_to_be16(ETH_P_AX25),
.func = ax25_kiss_rcv,
};
static struct notifier_block ax25_dev_notifier = {
.notifier_call = ax25_device_event,
};
static int __init ax25_init(void)
{
int rc = proto_register(&ax25_proto, 0);
if (rc != 0)
goto out;
sock_register(&ax25_family_ops);
dev_add_pack(&ax25_packet_type);
register_netdevice_notifier(&ax25_dev_notifier);
proc_create_seq("ax25_route", 0444, init_net.proc_net, &ax25_rt_seqops);
proc_create_seq("ax25", 0444, init_net.proc_net, &ax25_info_seqops);
proc_create_seq("ax25_calls", 0444, init_net.proc_net,
&ax25_uid_seqops);
out:
return rc;
}
module_init(ax25_init);
MODULE_AUTHOR("Jonathan Naylor G4KLX <g4klx@g4klx.demon.co.uk>");
MODULE_DESCRIPTION("The amateur radio AX.25 link layer protocol");
MODULE_LICENSE("GPL");
MODULE_ALIAS_NETPROTO(PF_AX25);
static void __exit ax25_exit(void)
{
remove_proc_entry("ax25_route", init_net.proc_net);
remove_proc_entry("ax25", init_net.proc_net);
remove_proc_entry("ax25_calls", init_net.proc_net);
unregister_netdevice_notifier(&ax25_dev_notifier);
dev_remove_pack(&ax25_packet_type);
sock_unregister(PF_AX25);
proto_unregister(&ax25_proto);
ax25_rt_free();
ax25_uid_free();
ax25_dev_free();
}
module_exit(ax25_exit);
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