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linux-stable/net/ax25/af_ax25.c
Duoming Zhou 219b51a6f0 net: ax25: Fix deadlock caused by skb_recv_datagram in ax25_recvmsg 
The skb_recv_datagram() in ax25_recvmsg() will hold lock_sock
and block until it receives a packet from the remote. If the client
doesn`t connect to server and calls read() directly, it will not
receive any packets forever. As a result, the deadlock will happen.

The fail log caused by deadlock is shown below:

[  369.606973] INFO: task ax25_deadlock:157 blocked for more than 245 seconds.
[  369.608919] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[  369.613058] Call Trace:
[  369.613315]  <TASK>
[  369.614072]  __schedule+0x2f9/0xb20
[  369.615029]  schedule+0x49/0xb0
[  369.615734]  __lock_sock+0x92/0x100
[  369.616763]  ? destroy_sched_domains_rcu+0x20/0x20
[  369.617941]  lock_sock_nested+0x6e/0x70
[  369.618809]  ax25_bind+0xaa/0x210
[  369.619736]  __sys_bind+0xca/0xf0
[  369.620039]  ? do_futex+0xae/0x1b0
[  369.620387]  ? __x64_sys_futex+0x7c/0x1c0
[  369.620601]  ? fpregs_assert_state_consistent+0x19/0x40
[  369.620613]  __x64_sys_bind+0x11/0x20
[  369.621791]  do_syscall_64+0x3b/0x90
[  369.622423]  entry_SYSCALL_64_after_hwframe+0x46/0xb0
[  369.623319] RIP: 0033:0x7f43c8aa8af7
[  369.624301] RSP: 002b:00007f43c8197ef8 EFLAGS: 00000246 ORIG_RAX: 0000000000000031
[  369.625756] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f43c8aa8af7
[  369.626724] RDX: 0000000000000010 RSI: 000055768e2021d0 RDI: 0000000000000005
[  369.628569] RBP: 00007f43c8197f00 R08: 0000000000000011 R09: 00007f43c8198700
[  369.630208] R10: 0000000000000000 R11: 0000000000000246 R12: 00007fff845e6afe
[  369.632240] R13: 00007fff845e6aff R14: 00007f43c8197fc0 R15: 00007f43c8198700

This patch replaces skb_recv_datagram() with an open-coded variant of it
releasing the socket lock before the __skb_wait_for_more_packets() call
and re-acquiring it after such call in order that other functions that
need socket lock could be executed.

what's more, the socket lock will be released only when recvmsg() will
block and that should produce nicer overall behavior.

Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Suggested-by: Thomas Osterried <thomas@osterried.de>
Signed-off-by: Duoming Zhou <duoming@zju.edu.cn>
Reported-by: Thomas Habets <thomas@@habets.se>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-06-15 13:00:22 +01:00

2082 lines
45 KiB
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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) {
dev_put_track(ax25_dev->dev, &ax25_dev->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 = (void *) &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) {
strlcpy(devname, ax25_dev->dev->name, sizeof(devname));
length = strlen(devname) + 1;
} else {
*devname = '\0';
length = 1;
}
valptr = (void *) 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 = 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);
}
dev_put_track(ax25_dev->dev, &ax25_dev->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);
dev_hold_track(ax25_dev->dev, &ax25_dev->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, int flags,
bool kern)
{
struct sk_buff *skb;
struct sock *newsk;
DEFINE_WAIT(wait);
struct sock *sk;
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 (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;
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,
.sendpage = sock_no_sendpage,
};
/*
* 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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