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remarkable-linux/net/netrom/af_netrom.c
David Howells cdfbabfb2f net: Work around lockdep limitation in sockets that use sockets 
Lockdep issues a circular dependency warning when AFS issues an operation
through AF_RXRPC from a context in which the VFS/VM holds the mmap_sem.

The theory lockdep comes up with is as follows:

 (1) If the pagefault handler decides it needs to read pages from AFS, it
     calls AFS with mmap_sem held and AFS begins an AF_RXRPC call, but
     creating a call requires the socket lock:

	mmap_sem must be taken before sk_lock-AF_RXRPC

 (2) afs_open_socket() opens an AF_RXRPC socket and binds it.  rxrpc_bind()
     binds the underlying UDP socket whilst holding its socket lock.
     inet_bind() takes its own socket lock:

	sk_lock-AF_RXRPC must be taken before sk_lock-AF_INET

 (3) Reading from a TCP socket into a userspace buffer might cause a fault
     and thus cause the kernel to take the mmap_sem, but the TCP socket is
     locked whilst doing this:

	sk_lock-AF_INET must be taken before mmap_sem

However, lockdep's theory is wrong in this instance because it deals only
with lock classes and not individual locks.  The AF_INET lock in (2) isn't
really equivalent to the AF_INET lock in (3) as the former deals with a
socket entirely internal to the kernel that never sees userspace.  This is
a limitation in the design of lockdep.

Fix the general case by:

 (1) Double up all the locking keys used in sockets so that one set are
     used if the socket is created by userspace and the other set is used
     if the socket is created by the kernel.

 (2) Store the kern parameter passed to sk_alloc() in a variable in the
     sock struct (sk_kern_sock).  This informs sock_lock_init(),
     sock_init_data() and sk_clone_lock() as to the lock keys to be used.

     Note that the child created by sk_clone_lock() inherits the parent's
     kern setting.

 (3) Add a 'kern' parameter to ->accept() that is analogous to the one
     passed in to ->create() that distinguishes whether kernel_accept() or
     sys_accept4() was the caller and can be passed to sk_alloc().

     Note that a lot of accept functions merely dequeue an already
     allocated socket.  I haven't touched these as the new socket already
     exists before we get the parameter.

     Note also that there are a couple of places where I've made the accepted
     socket unconditionally kernel-based:

	irda_accept()
	rds_rcp_accept_one()
	tcp_accept_from_sock()

     because they follow a sock_create_kern() and accept off of that.

Whilst creating this, I noticed that lustre and ocfs don't create sockets
through sock_create_kern() and thus they aren't marked as for-kernel,
though they appear to be internal.  I wonder if these should do that so
that they use the new set of lock keys.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-09 18:23:27 -08:00

1513 lines
32 KiB
C
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/*
* 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 Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk)
* Copyright Alan Cox GW4PTS (alan@lxorguk.ukuu.org.uk)
* Copyright Darryl Miles G7LED (dlm@g7led.demon.co.uk)
*/
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/capability.h>
#include <linux/errno.h>
#include <linux/types.h>
#include <linux/socket.h>
#include <linux/in.h>
#include <linux/slab.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/stat.h>
#include <net/ax25.h>
#include <linux/inet.h>
#include <linux/netdevice.h>
#include <linux/if_arp.h>
#include <linux/skbuff.h>
#include <net/net_namespace.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 <net/netrom.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <net/ip.h>
#include <net/tcp_states.h>
#include <net/arp.h>
#include <linux/init.h>
static int nr_ndevs = 4;
int sysctl_netrom_default_path_quality = NR_DEFAULT_QUAL;
int sysctl_netrom_obsolescence_count_initialiser = NR_DEFAULT_OBS;
int sysctl_netrom_network_ttl_initialiser = NR_DEFAULT_TTL;
int sysctl_netrom_transport_timeout = NR_DEFAULT_T1;
int sysctl_netrom_transport_maximum_tries = NR_DEFAULT_N2;
int sysctl_netrom_transport_acknowledge_delay = NR_DEFAULT_T2;
int sysctl_netrom_transport_busy_delay = NR_DEFAULT_T4;
int sysctl_netrom_transport_requested_window_size = NR_DEFAULT_WINDOW;
int sysctl_netrom_transport_no_activity_timeout = NR_DEFAULT_IDLE;
int sysctl_netrom_routing_control = NR_DEFAULT_ROUTING;
int sysctl_netrom_link_fails_count = NR_DEFAULT_FAILS;
int sysctl_netrom_reset_circuit = NR_DEFAULT_RESET;
static unsigned short circuit = 0x101;
static HLIST_HEAD(nr_list);
static DEFINE_SPINLOCK(nr_list_lock);
static const struct proto_ops nr_proto_ops;
/*
* NETROM network devices are virtual network devices encapsulating NETROM
* frames into AX.25 which will be sent through an AX.25 device, so form a
* special "super class" of normal net devices; split their locks off into a
* separate class since they always nest.
*/
static struct lock_class_key nr_netdev_xmit_lock_key;
static struct lock_class_key nr_netdev_addr_lock_key;
static void nr_set_lockdep_one(struct net_device *dev,
struct netdev_queue *txq,
void *_unused)
{
lockdep_set_class(&txq->_xmit_lock, &nr_netdev_xmit_lock_key);
}
static void nr_set_lockdep_key(struct net_device *dev)
{
lockdep_set_class(&dev->addr_list_lock, &nr_netdev_addr_lock_key);
netdev_for_each_tx_queue(dev, nr_set_lockdep_one, NULL);
}
/*
* Socket removal during an interrupt is now safe.
*/
static void nr_remove_socket(struct sock *sk)
{
spin_lock_bh(&nr_list_lock);
sk_del_node_init(sk);
spin_unlock_bh(&nr_list_lock);
}
/*
* Kill all bound sockets on a dropped device.
*/
static void nr_kill_by_device(struct net_device *dev)
{
struct sock *s;
spin_lock_bh(&nr_list_lock);
sk_for_each(s, &nr_list)
if (nr_sk(s)->device == dev)
nr_disconnect(s, ENETUNREACH);
spin_unlock_bh(&nr_list_lock);
}
/*
* Handle device status changes.
*/
static int nr_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;
if (event != NETDEV_DOWN)
return NOTIFY_DONE;
nr_kill_by_device(dev);
nr_rt_device_down(dev);
return NOTIFY_DONE;
}
/*
* Add a socket to the bound sockets list.
*/
static void nr_insert_socket(struct sock *sk)
{
spin_lock_bh(&nr_list_lock);
sk_add_node(sk, &nr_list);
spin_unlock_bh(&nr_list_lock);
}
/*
* Find a socket that wants to accept the Connect Request we just
* received.
*/
static struct sock *nr_find_listener(ax25_address *addr)
{
struct sock *s;
spin_lock_bh(&nr_list_lock);
sk_for_each(s, &nr_list)
if (!ax25cmp(&nr_sk(s)->source_addr, addr) &&
s->sk_state == TCP_LISTEN) {
bh_lock_sock(s);
goto found;
}
s = NULL;
found:
spin_unlock_bh(&nr_list_lock);
return s;
}
/*
* Find a connected NET/ROM socket given my circuit IDs.
*/
static struct sock *nr_find_socket(unsigned char index, unsigned char id)
{
struct sock *s;
spin_lock_bh(&nr_list_lock);
sk_for_each(s, &nr_list) {
struct nr_sock *nr = nr_sk(s);
if (nr->my_index == index && nr->my_id == id) {
bh_lock_sock(s);
goto found;
}
}
s = NULL;
found:
spin_unlock_bh(&nr_list_lock);
return s;
}
/*
* Find a connected NET/ROM socket given their circuit IDs.
*/
static struct sock *nr_find_peer(unsigned char index, unsigned char id,
ax25_address *dest)
{
struct sock *s;
spin_lock_bh(&nr_list_lock);
sk_for_each(s, &nr_list) {
struct nr_sock *nr = nr_sk(s);
if (nr->your_index == index && nr->your_id == id &&
!ax25cmp(&nr->dest_addr, dest)) {
bh_lock_sock(s);
goto found;
}
}
s = NULL;
found:
spin_unlock_bh(&nr_list_lock);
return s;
}
/*
* Find next free circuit ID.
*/
static unsigned short nr_find_next_circuit(void)
{
unsigned short id = circuit;
unsigned char i, j;
struct sock *sk;
for (;;) {
i = id / 256;
j = id % 256;
if (i != 0 && j != 0) {
if ((sk=nr_find_socket(i, j)) == NULL)
break;
bh_unlock_sock(sk);
}
id++;
}
return id;
}
/*
* Deferred destroy.
*/
void nr_destroy_socket(struct sock *);
/*
* Handler for deferred kills.
*/
static void nr_destroy_timer(unsigned long data)
{
struct sock *sk=(struct sock *)data;
bh_lock_sock(sk);
sock_hold(sk);
nr_destroy_socket(sk);
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 nr_destroy_socket(struct sock *sk)
{
struct sk_buff *skb;
nr_remove_socket(sk);
nr_stop_heartbeat(sk);
nr_stop_t1timer(sk);
nr_stop_t2timer(sk);
nr_stop_t4timer(sk);
nr_stop_idletimer(sk);
nr_clear_queues(sk); /* Flush the queues */
while ((skb = skb_dequeue(&sk->sk_receive_queue)) != NULL) {
if (skb->sk != sk) { /* A pending connection */
/* Queue the unaccepted socket for death */
sock_set_flag(skb->sk, SOCK_DEAD);
nr_start_heartbeat(skb->sk);
nr_sk(skb->sk)->state = NR_STATE_0;
}
kfree_skb(skb);
}
if (sk_has_allocations(sk)) {
/* Defer: outstanding buffers */
sk->sk_timer.function = nr_destroy_timer;
sk->sk_timer.expires = jiffies + 2 * HZ;
add_timer(&sk->sk_timer);
} else
sock_put(sk);
}
/*
* Handling for system calls applied via the various interfaces to a
* NET/ROM socket object.
*/
static int nr_setsockopt(struct socket *sock, int level, int optname,
char __user *optval, unsigned int optlen)
{
struct sock *sk = sock->sk;
struct nr_sock *nr = nr_sk(sk);
unsigned long opt;
if (level != SOL_NETROM)
return -ENOPROTOOPT;
if (optlen < sizeof(unsigned int))
return -EINVAL;
if (get_user(opt, (unsigned int __user *)optval))
return -EFAULT;
switch (optname) {
case NETROM_T1:
if (opt < 1 || opt > ULONG_MAX / HZ)
return -EINVAL;
nr->t1 = opt * HZ;
return 0;
case NETROM_T2:
if (opt < 1 || opt > ULONG_MAX / HZ)
return -EINVAL;
nr->t2 = opt * HZ;
return 0;
case NETROM_N2:
if (opt < 1 || opt > 31)
return -EINVAL;
nr->n2 = opt;
return 0;
case NETROM_T4:
if (opt < 1 || opt > ULONG_MAX / HZ)
return -EINVAL;
nr->t4 = opt * HZ;
return 0;
case NETROM_IDLE:
if (opt > ULONG_MAX / (60 * HZ))
return -EINVAL;
nr->idle = opt * 60 * HZ;
return 0;
default:
return -ENOPROTOOPT;
}
}
static int nr_getsockopt(struct socket *sock, int level, int optname,
char __user *optval, int __user *optlen)
{
struct sock *sk = sock->sk;
struct nr_sock *nr = nr_sk(sk);
int val = 0;
int len;
if (level != SOL_NETROM)
return -ENOPROTOOPT;
if (get_user(len, optlen))
return -EFAULT;
if (len < 0)
return -EINVAL;
switch (optname) {
case NETROM_T1:
val = nr->t1 / HZ;
break;
case NETROM_T2:
val = nr->t2 / HZ;
break;
case NETROM_N2:
val = nr->n2;
break;
case NETROM_T4:
val = nr->t4 / HZ;
break;
case NETROM_IDLE:
val = nr->idle / (60 * HZ);
break;
default:
return -ENOPROTOOPT;
}
len = min_t(unsigned int, len, sizeof(int));
if (put_user(len, optlen))
return -EFAULT;
return copy_to_user(optval, &val, len) ? -EFAULT : 0;
}
static int nr_listen(struct socket *sock, int backlog)
{
struct sock *sk = sock->sk;
lock_sock(sk);
if (sk->sk_state != TCP_LISTEN) {
memset(&nr_sk(sk)->user_addr, 0, AX25_ADDR_LEN);
sk->sk_max_ack_backlog = backlog;
sk->sk_state = TCP_LISTEN;
release_sock(sk);
return 0;
}
release_sock(sk);
return -EOPNOTSUPP;
}
static struct proto nr_proto = {
.name = "NETROM",
.owner = THIS_MODULE,
.obj_size = sizeof(struct nr_sock),
};
static int nr_create(struct net *net, struct socket *sock, int protocol,
int kern)
{
struct sock *sk;
struct nr_sock *nr;
if (!net_eq(net, &init_net))
return -EAFNOSUPPORT;
if (sock->type != SOCK_SEQPACKET || protocol != 0)
return -ESOCKTNOSUPPORT;
sk = sk_alloc(net, PF_NETROM, GFP_ATOMIC, &nr_proto, kern);
if (sk == NULL)
return -ENOMEM;
nr = nr_sk(sk);
sock_init_data(sock, sk);
sock->ops = &nr_proto_ops;
sk->sk_protocol = protocol;
skb_queue_head_init(&nr->ack_queue);
skb_queue_head_init(&nr->reseq_queue);
skb_queue_head_init(&nr->frag_queue);
nr_init_timers(sk);
nr->t1 =
msecs_to_jiffies(sysctl_netrom_transport_timeout);
nr->t2 =
msecs_to_jiffies(sysctl_netrom_transport_acknowledge_delay);
nr->n2 =
msecs_to_jiffies(sysctl_netrom_transport_maximum_tries);
nr->t4 =
msecs_to_jiffies(sysctl_netrom_transport_busy_delay);
nr->idle =
msecs_to_jiffies(sysctl_netrom_transport_no_activity_timeout);
nr->window = sysctl_netrom_transport_requested_window_size;
nr->bpqext = 1;
nr->state = NR_STATE_0;
return 0;
}
static struct sock *nr_make_new(struct sock *osk)
{
struct sock *sk;
struct nr_sock *nr, *onr;
if (osk->sk_type != SOCK_SEQPACKET)
return NULL;
sk = sk_alloc(sock_net(osk), PF_NETROM, GFP_ATOMIC, osk->sk_prot, 0);
if (sk == NULL)
return NULL;
nr = nr_sk(sk);
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);
skb_queue_head_init(&nr->ack_queue);
skb_queue_head_init(&nr->reseq_queue);
skb_queue_head_init(&nr->frag_queue);
nr_init_timers(sk);
onr = nr_sk(osk);
nr->t1 = onr->t1;
nr->t2 = onr->t2;
nr->n2 = onr->n2;
nr->t4 = onr->t4;
nr->idle = onr->idle;
nr->window = onr->window;
nr->device = onr->device;
nr->bpqext = onr->bpqext;
return sk;
}
static int nr_release(struct socket *sock)
{
struct sock *sk = sock->sk;
struct nr_sock *nr;
if (sk == NULL) return 0;
sock_hold(sk);
sock_orphan(sk);
lock_sock(sk);
nr = nr_sk(sk);
switch (nr->state) {
case NR_STATE_0:
case NR_STATE_1:
case NR_STATE_2:
nr_disconnect(sk, 0);
nr_destroy_socket(sk);
break;
case NR_STATE_3:
nr_clear_queues(sk);
nr->n2count = 0;
nr_write_internal(sk, NR_DISCREQ);
nr_start_t1timer(sk);
nr_stop_t2timer(sk);
nr_stop_t4timer(sk);
nr_stop_idletimer(sk);
nr->state = NR_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;
}
sock->sk = NULL;
release_sock(sk);
sock_put(sk);
return 0;
}
static int nr_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
{
struct sock *sk = sock->sk;
struct nr_sock *nr = nr_sk(sk);
struct full_sockaddr_ax25 *addr = (struct full_sockaddr_ax25 *)uaddr;
struct net_device *dev;
ax25_uid_assoc *user;
ax25_address *source;
lock_sock(sk);
if (!sock_flag(sk, SOCK_ZAPPED)) {
release_sock(sk);
return -EINVAL;
}
if (addr_len < sizeof(struct sockaddr_ax25) || addr_len > sizeof(struct full_sockaddr_ax25)) {
release_sock(sk);
return -EINVAL;
}
if (addr_len < (addr->fsa_ax25.sax25_ndigis * sizeof(ax25_address) + sizeof(struct sockaddr_ax25))) {
release_sock(sk);
return -EINVAL;
}
if (addr->fsa_ax25.sax25_family != AF_NETROM) {
release_sock(sk);
return -EINVAL;
}
if ((dev = nr_dev_get(&addr->fsa_ax25.sax25_call)) == NULL) {
release_sock(sk);
return -EADDRNOTAVAIL;
}
/*
* Only the super user can set an arbitrary user callsign.
*/
if (addr->fsa_ax25.sax25_ndigis == 1) {
if (!capable(CAP_NET_BIND_SERVICE)) {
dev_put(dev);
release_sock(sk);
return -EPERM;
}
nr->user_addr = addr->fsa_digipeater[0];
nr->source_addr = addr->fsa_ax25.sax25_call;
} else {
source = &addr->fsa_ax25.sax25_call;
user = ax25_findbyuid(current_euid());
if (user) {
nr->user_addr = user->call;
ax25_uid_put(user);
} else {
if (ax25_uid_policy && !capable(CAP_NET_BIND_SERVICE)) {
release_sock(sk);
dev_put(dev);
return -EPERM;
}
nr->user_addr = *source;
}
nr->source_addr = *source;
}
nr->device = dev;
nr_insert_socket(sk);
sock_reset_flag(sk, SOCK_ZAPPED);
dev_put(dev);
release_sock(sk);
return 0;
}
static int nr_connect(struct socket *sock, struct sockaddr *uaddr,
int addr_len, int flags)
{
struct sock *sk = sock->sk;
struct nr_sock *nr = nr_sk(sk);
struct sockaddr_ax25 *addr = (struct sockaddr_ax25 *)uaddr;
ax25_address *source = NULL;
ax25_uid_assoc *user;
struct net_device *dev;
int err = 0;
lock_sock(sk);
if (sk->sk_state == TCP_ESTABLISHED && sock->state == SS_CONNECTING) {
sock->state = SS_CONNECTED;
goto out_release; /* Connect completed during a ERESTARTSYS event */
}
if (sk->sk_state == TCP_CLOSE && sock->state == SS_CONNECTING) {
sock->state = SS_UNCONNECTED;
err = -ECONNREFUSED;
goto out_release;
}
if (sk->sk_state == TCP_ESTABLISHED) {
err = -EISCONN; /* No reconnect on a seqpacket socket */
goto out_release;
}
sk->sk_state = TCP_CLOSE;
sock->state = SS_UNCONNECTED;
if (addr_len != sizeof(struct sockaddr_ax25) && addr_len != sizeof(struct full_sockaddr_ax25)) {
err = -EINVAL;
goto out_release;
}
if (addr->sax25_family != AF_NETROM) {
err = -EINVAL;
goto out_release;
}
if (sock_flag(sk, SOCK_ZAPPED)) { /* Must bind first - autobinding in this may or may not work */
sock_reset_flag(sk, SOCK_ZAPPED);
if ((dev = nr_dev_first()) == NULL) {
err = -ENETUNREACH;
goto out_release;
}
source = (ax25_address *)dev->dev_addr;
user = ax25_findbyuid(current_euid());
if (user) {
nr->user_addr = user->call;
ax25_uid_put(user);
} else {
if (ax25_uid_policy && !capable(CAP_NET_ADMIN)) {
dev_put(dev);
err = -EPERM;
goto out_release;
}
nr->user_addr = *source;
}
nr->source_addr = *source;
nr->device = dev;
dev_put(dev);
nr_insert_socket(sk); /* Finish the bind */
}
nr->dest_addr = addr->sax25_call;
release_sock(sk);
circuit = nr_find_next_circuit();
lock_sock(sk);
nr->my_index = circuit / 256;
nr->my_id = circuit % 256;
circuit++;
/* Move to connecting socket, start sending Connect Requests */
sock->state = SS_CONNECTING;
sk->sk_state = TCP_SYN_SENT;
nr_establish_data_link(sk);
nr->state = NR_STATE_1;
nr_start_heartbeat(sk);
/* Now the loop */
if (sk->sk_state != TCP_ESTABLISHED && (flags & O_NONBLOCK)) {
err = -EINPROGRESS;
goto out_release;
}
/*
* A Connect Ack with Choke or timeout or failed routing will go to
* closed.
*/
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) {
sock->state = SS_UNCONNECTED;
err = sock_error(sk); /* Always set at this point */
goto out_release;
}
sock->state = SS_CONNECTED;
out_release:
release_sock(sk);
return err;
}
static int nr_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 ((sk = sock->sk) == NULL)
return -EINVAL;
lock_sock(sk);
if (sk->sk_type != SOCK_SEQPACKET) {
err = -EOPNOTSUPP;
goto out_release;
}
if (sk->sk_state != TCP_LISTEN) {
err = -EINVAL;
goto out_release;
}
/*
* The write 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_release;
newsk = skb->sk;
sock_graft(newsk, newsock);
/* Now attach up the new socket */
kfree_skb(skb);
sk_acceptq_removed(sk);
out_release:
release_sock(sk);
return err;
}
static int nr_getname(struct socket *sock, struct sockaddr *uaddr,
int *uaddr_len, int peer)
{
struct full_sockaddr_ax25 *sax = (struct full_sockaddr_ax25 *)uaddr;
struct sock *sk = sock->sk;
struct nr_sock *nr = nr_sk(sk);
memset(&sax->fsa_ax25, 0, sizeof(struct sockaddr_ax25));
lock_sock(sk);
if (peer != 0) {
if (sk->sk_state != TCP_ESTABLISHED) {
release_sock(sk);
return -ENOTCONN;
}
sax->fsa_ax25.sax25_family = AF_NETROM;
sax->fsa_ax25.sax25_ndigis = 1;
sax->fsa_ax25.sax25_call = nr->user_addr;
memset(sax->fsa_digipeater, 0, sizeof(sax->fsa_digipeater));
sax->fsa_digipeater[0] = nr->dest_addr;
*uaddr_len = sizeof(struct full_sockaddr_ax25);
} else {
sax->fsa_ax25.sax25_family = AF_NETROM;
sax->fsa_ax25.sax25_ndigis = 0;
sax->fsa_ax25.sax25_call = nr->source_addr;
*uaddr_len = sizeof(struct sockaddr_ax25);
}
release_sock(sk);
return 0;
}
int nr_rx_frame(struct sk_buff *skb, struct net_device *dev)
{
struct sock *sk;
struct sock *make;
struct nr_sock *nr_make;
ax25_address *src, *dest, *user;
unsigned short circuit_index, circuit_id;
unsigned short peer_circuit_index, peer_circuit_id;
unsigned short frametype, flags, window, timeout;
int ret;
skb->sk = NULL; /* Initially we don't know who it's for */
/*
* skb->data points to the netrom frame start
*/
src = (ax25_address *)(skb->data + 0);
dest = (ax25_address *)(skb->data + 7);
circuit_index = skb->data[15];
circuit_id = skb->data[16];
peer_circuit_index = skb->data[17];
peer_circuit_id = skb->data[18];
frametype = skb->data[19] & 0x0F;
flags = skb->data[19] & 0xF0;
/*
* Check for an incoming IP over NET/ROM frame.
*/
if (frametype == NR_PROTOEXT &&
circuit_index == NR_PROTO_IP && circuit_id == NR_PROTO_IP) {
skb_pull(skb, NR_NETWORK_LEN + NR_TRANSPORT_LEN);
skb_reset_transport_header(skb);
return nr_rx_ip(skb, dev);
}
/*
* Find an existing socket connection, based on circuit ID, if it's
* a Connect Request base it on their circuit ID.
*
* Circuit ID 0/0 is not valid but it could still be a "reset" for a
* circuit that no longer exists at the other end ...
*/
sk = NULL;
if (circuit_index == 0 && circuit_id == 0) {
if (frametype == NR_CONNACK && flags == NR_CHOKE_FLAG)
sk = nr_find_peer(peer_circuit_index, peer_circuit_id, src);
} else {
if (frametype == NR_CONNREQ)
sk = nr_find_peer(circuit_index, circuit_id, src);
else
sk = nr_find_socket(circuit_index, circuit_id);
}
if (sk != NULL) {
skb_reset_transport_header(skb);
if (frametype == NR_CONNACK && skb->len == 22)
nr_sk(sk)->bpqext = 1;
else
nr_sk(sk)->bpqext = 0;
ret = nr_process_rx_frame(sk, skb);
bh_unlock_sock(sk);
return ret;
}
/*
* Now it should be a CONNREQ.
*/
if (frametype != NR_CONNREQ) {
/*
* Here it would be nice to be able to send a reset but
* NET/ROM doesn't have one. We've tried to extend the protocol
* by sending NR_CONNACK | NR_CHOKE_FLAGS replies but that
* apparently kills BPQ boxes... :-(
* So now we try to follow the established behaviour of
* G8PZT's Xrouter which is sending packets with command type 7
* as an extension of the protocol.
*/
if (sysctl_netrom_reset_circuit &&
(frametype != NR_RESET || flags != 0))
nr_transmit_reset(skb, 1);
return 0;
}
sk = nr_find_listener(dest);
user = (ax25_address *)(skb->data + 21);
if (sk == NULL || sk_acceptq_is_full(sk) ||
(make = nr_make_new(sk)) == NULL) {
nr_transmit_refusal(skb, 0);
if (sk)
bh_unlock_sock(sk);
return 0;
}
window = skb->data[20];
skb->sk = make;
make->sk_state = TCP_ESTABLISHED;
/* Fill in his circuit details */
nr_make = nr_sk(make);
nr_make->source_addr = *dest;
nr_make->dest_addr = *src;
nr_make->user_addr = *user;
nr_make->your_index = circuit_index;
nr_make->your_id = circuit_id;
bh_unlock_sock(sk);
circuit = nr_find_next_circuit();
bh_lock_sock(sk);
nr_make->my_index = circuit / 256;
nr_make->my_id = circuit % 256;
circuit++;
/* Window negotiation */
if (window < nr_make->window)
nr_make->window = window;
/* L4 timeout negotiation */
if (skb->len == 37) {
timeout = skb->data[36] * 256 + skb->data[35];
if (timeout * HZ < nr_make->t1)
nr_make->t1 = timeout * HZ;
nr_make->bpqext = 1;
} else {
nr_make->bpqext = 0;
}
nr_write_internal(make, NR_CONNACK);
nr_make->condition = 0x00;
nr_make->vs = 0;
nr_make->va = 0;
nr_make->vr = 0;
nr_make->vl = 0;
nr_make->state = NR_STATE_3;
sk_acceptq_added(sk);
skb_queue_head(&sk->sk_receive_queue, skb);
if (!sock_flag(sk, SOCK_DEAD))
sk->sk_data_ready(sk);
bh_unlock_sock(sk);
nr_insert_socket(make);
nr_start_heartbeat(make);
nr_start_idletimer(make);
return 1;
}
static int nr_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
{
struct sock *sk = sock->sk;
struct nr_sock *nr = nr_sk(sk);
DECLARE_SOCKADDR(struct sockaddr_ax25 *, usax, msg->msg_name);
int err;
struct sockaddr_ax25 sax;
struct sk_buff *skb;
unsigned char *asmptr;
int size;
if (msg->msg_flags & ~(MSG_DONTWAIT|MSG_EOR|MSG_CMSG_COMPAT))
return -EINVAL;
lock_sock(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 (nr->device == NULL) {
err = -ENETUNREACH;
goto out;
}
if (usax) {
if (msg->msg_namelen < sizeof(sax)) {
err = -EINVAL;
goto out;
}
sax = *usax;
if (ax25cmp(&nr->dest_addr, &sax.sax25_call) != 0) {
err = -EISCONN;
goto out;
}
if (sax.sax25_family != AF_NETROM) {
err = -EINVAL;
goto out;
}
} else {
if (sk->sk_state != TCP_ESTABLISHED) {
err = -ENOTCONN;
goto out;
}
sax.sax25_family = AF_NETROM;
sax.sax25_call = nr->dest_addr;
}
/* Build a packet - the conventional user limit is 236 bytes. We can
do ludicrously large NetROM frames but must not overflow */
if (len > 65536) {
err = -EMSGSIZE;
goto out;
}
size = len + NR_NETWORK_LEN + NR_TRANSPORT_LEN;
if ((skb = sock_alloc_send_skb(sk, size, msg->msg_flags & MSG_DONTWAIT, &err)) == NULL)
goto out;
skb_reserve(skb, size - len);
skb_reset_transport_header(skb);
/*
* Push down the NET/ROM header
*/
asmptr = skb_push(skb, NR_TRANSPORT_LEN);
/* Build a NET/ROM Transport header */
*asmptr++ = nr->your_index;
*asmptr++ = nr->your_id;
*asmptr++ = 0; /* To be filled in later */
*asmptr++ = 0; /* Ditto */
*asmptr++ = NR_INFO;
/*
* Put the data on the end
*/
skb_put(skb, len);
/* User data follows immediately after the NET/ROM transport header */
if (memcpy_from_msg(skb_transport_header(skb), msg, len)) {
kfree_skb(skb);
err = -EFAULT;
goto out;
}
if (sk->sk_state != TCP_ESTABLISHED) {
kfree_skb(skb);
err = -ENOTCONN;
goto out;
}
nr_output(sk, skb); /* Shove it onto the queue */
err = len;
out:
release_sock(sk);
return err;
}
static int nr_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
int flags)
{
struct sock *sk = sock->sk;
DECLARE_SOCKADDR(struct sockaddr_ax25 *, sax, msg->msg_name);
size_t copied;
struct sk_buff *skb;
int er;
/*
* This works for seqpacket too. The receiver has ordered the queue for
* us! We do one quick check first though
*/
lock_sock(sk);
if (sk->sk_state != TCP_ESTABLISHED) {
release_sock(sk);
return -ENOTCONN;
}
/* Now we can treat all alike */
if ((skb = skb_recv_datagram(sk, flags & ~MSG_DONTWAIT, flags & MSG_DONTWAIT, &er)) == NULL) {
release_sock(sk);
return er;
}
skb_reset_transport_header(skb);
copied = skb->len;
if (copied > size) {
copied = size;
msg->msg_flags |= MSG_TRUNC;
}
er = skb_copy_datagram_msg(skb, 0, msg, copied);
if (er < 0) {
skb_free_datagram(sk, skb);
release_sock(sk);
return er;
}
if (sax != NULL) {
memset(sax, 0, sizeof(*sax));
sax->sax25_family = AF_NETROM;
skb_copy_from_linear_data_offset(skb, 7, sax->sax25_call.ax25_call,
AX25_ADDR_LEN);
msg->msg_namelen = sizeof(*sax);
}
skb_free_datagram(sk, skb);
release_sock(sk);
return copied;
}
static int nr_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
{
struct sock *sk = sock->sk;
void __user *argp = (void __user *)arg;
int ret;
switch (cmd) {
case TIOCOUTQ: {
long amount;
lock_sock(sk);
amount = sk->sk_sndbuf - sk_wmem_alloc_get(sk);
if (amount < 0)
amount = 0;
release_sock(sk);
return put_user(amount, (int __user *)argp);
}
case TIOCINQ: {
struct sk_buff *skb;
long amount = 0L;
lock_sock(sk);
/* 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;
release_sock(sk);
return put_user(amount, (int __user *)argp);
}
case SIOCGSTAMP:
lock_sock(sk);
ret = sock_get_timestamp(sk, argp);
release_sock(sk);
return ret;
case SIOCGSTAMPNS:
lock_sock(sk);
ret = sock_get_timestampns(sk, argp);
release_sock(sk);
return ret;
case SIOCGIFADDR:
case SIOCSIFADDR:
case SIOCGIFDSTADDR:
case SIOCSIFDSTADDR:
case SIOCGIFBRDADDR:
case SIOCSIFBRDADDR:
case SIOCGIFNETMASK:
case SIOCSIFNETMASK:
case SIOCGIFMETRIC:
case SIOCSIFMETRIC:
return -EINVAL;
case SIOCADDRT:
case SIOCDELRT:
case SIOCNRDECOBS:
if (!capable(CAP_NET_ADMIN))
return -EPERM;
return nr_rt_ioctl(cmd, argp);
default:
return -ENOIOCTLCMD;
}
return 0;
}
#ifdef CONFIG_PROC_FS
static void *nr_info_start(struct seq_file *seq, loff_t *pos)
{
spin_lock_bh(&nr_list_lock);
return seq_hlist_start_head(&nr_list, *pos);
}
static void *nr_info_next(struct seq_file *seq, void *v, loff_t *pos)
{
return seq_hlist_next(v, &nr_list, pos);
}
static void nr_info_stop(struct seq_file *seq, void *v)
{
spin_unlock_bh(&nr_list_lock);
}
static int nr_info_show(struct seq_file *seq, void *v)
{
struct sock *s = sk_entry(v);
struct net_device *dev;
struct nr_sock *nr;
const char *devname;
char buf[11];
if (v == SEQ_START_TOKEN)
seq_puts(seq,
"user_addr dest_node src_node dev my your st vs vr va t1 t2 t4 idle n2 wnd Snd-Q Rcv-Q inode\n");
else {
bh_lock_sock(s);
nr = nr_sk(s);
if ((dev = nr->device) == NULL)
devname = "???";
else
devname = dev->name;
seq_printf(seq, "%-9s ", ax2asc(buf, &nr->user_addr));
seq_printf(seq, "%-9s ", ax2asc(buf, &nr->dest_addr));
seq_printf(seq,
"%-9s %-3s %02X/%02X %02X/%02X %2d %3d %3d %3d %3lu/%03lu %2lu/%02lu %3lu/%03lu %3lu/%03lu %2d/%02d %3d %5d %5d %ld\n",
ax2asc(buf, &nr->source_addr),
devname,
nr->my_index,
nr->my_id,
nr->your_index,
nr->your_id,
nr->state,
nr->vs,
nr->vr,
nr->va,
ax25_display_timer(&nr->t1timer) / HZ,
nr->t1 / HZ,
ax25_display_timer(&nr->t2timer) / HZ,
nr->t2 / HZ,
ax25_display_timer(&nr->t4timer) / HZ,
nr->t4 / HZ,
ax25_display_timer(&nr->idletimer) / (60 * HZ),
nr->idle / (60 * HZ),
nr->n2count,
nr->n2,
nr->window,
sk_wmem_alloc_get(s),
sk_rmem_alloc_get(s),
s->sk_socket ? SOCK_INODE(s->sk_socket)->i_ino : 0L);
bh_unlock_sock(s);
}
return 0;
}
static const struct seq_operations nr_info_seqops = {
.start = nr_info_start,
.next = nr_info_next,
.stop = nr_info_stop,
.show = nr_info_show,
};
static int nr_info_open(struct inode *inode, struct file *file)
{
return seq_open(file, &nr_info_seqops);
}
static const struct file_operations nr_info_fops = {
.owner = THIS_MODULE,
.open = nr_info_open,
.read = seq_read,
.llseek = seq_lseek,
.release = seq_release,
};
#endif /* CONFIG_PROC_FS */
static const struct net_proto_family nr_family_ops = {
.family = PF_NETROM,
.create = nr_create,
.owner = THIS_MODULE,
};
static const struct proto_ops nr_proto_ops = {
.family = PF_NETROM,
.owner = THIS_MODULE,
.release = nr_release,
.bind = nr_bind,
.connect = nr_connect,
.socketpair = sock_no_socketpair,
.accept = nr_accept,
.getname = nr_getname,
.poll = datagram_poll,
.ioctl = nr_ioctl,
.listen = nr_listen,
.shutdown = sock_no_shutdown,
.setsockopt = nr_setsockopt,
.getsockopt = nr_getsockopt,
.sendmsg = nr_sendmsg,
.recvmsg = nr_recvmsg,
.mmap = sock_no_mmap,
.sendpage = sock_no_sendpage,
};
static struct notifier_block nr_dev_notifier = {
.notifier_call = nr_device_event,
};
static struct net_device **dev_nr;
static struct ax25_protocol nr_pid = {
.pid = AX25_P_NETROM,
.func = nr_route_frame
};
static struct ax25_linkfail nr_linkfail_notifier = {
.func = nr_link_failed,
};
static int __init nr_proto_init(void)
{
int i;
int rc = proto_register(&nr_proto, 0);
if (rc != 0)
goto out;
if (nr_ndevs > 0x7fffffff/sizeof(struct net_device *)) {
printk(KERN_ERR "NET/ROM: nr_proto_init - nr_ndevs parameter to large\n");
return -1;
}
dev_nr = kzalloc(nr_ndevs * sizeof(struct net_device *), GFP_KERNEL);
if (dev_nr == NULL) {
printk(KERN_ERR "NET/ROM: nr_proto_init - unable to allocate device array\n");
return -1;
}
for (i = 0; i < nr_ndevs; i++) {
char name[IFNAMSIZ];
struct net_device *dev;
sprintf(name, "nr%d", i);
dev = alloc_netdev(0, name, NET_NAME_UNKNOWN, nr_setup);
if (!dev) {
printk(KERN_ERR "NET/ROM: nr_proto_init - unable to allocate device structure\n");
goto fail;
}
dev->base_addr = i;
if (register_netdev(dev)) {
printk(KERN_ERR "NET/ROM: nr_proto_init - unable to register network device\n");
free_netdev(dev);
goto fail;
}
nr_set_lockdep_key(dev);
dev_nr[i] = dev;
}
if (sock_register(&nr_family_ops)) {
printk(KERN_ERR "NET/ROM: nr_proto_init - unable to register socket family\n");
goto fail;
}
register_netdevice_notifier(&nr_dev_notifier);
ax25_register_pid(&nr_pid);
ax25_linkfail_register(&nr_linkfail_notifier);
#ifdef CONFIG_SYSCTL
nr_register_sysctl();
#endif
nr_loopback_init();
proc_create("nr", S_IRUGO, init_net.proc_net, &nr_info_fops);
proc_create("nr_neigh", S_IRUGO, init_net.proc_net, &nr_neigh_fops);
proc_create("nr_nodes", S_IRUGO, init_net.proc_net, &nr_nodes_fops);
out:
return rc;
fail:
while (--i >= 0) {
unregister_netdev(dev_nr[i]);
free_netdev(dev_nr[i]);
}
kfree(dev_nr);
proto_unregister(&nr_proto);
rc = -1;
goto out;
}
module_init(nr_proto_init);
module_param(nr_ndevs, int, 0);
MODULE_PARM_DESC(nr_ndevs, "number of NET/ROM devices");
MODULE_AUTHOR("Jonathan Naylor G4KLX <g4klx@g4klx.demon.co.uk>");
MODULE_DESCRIPTION("The amateur radio NET/ROM network and transport layer protocol");
MODULE_LICENSE("GPL");
MODULE_ALIAS_NETPROTO(PF_NETROM);
static void __exit nr_exit(void)
{
int i;
remove_proc_entry("nr", init_net.proc_net);
remove_proc_entry("nr_neigh", init_net.proc_net);
remove_proc_entry("nr_nodes", init_net.proc_net);
nr_loopback_clear();
nr_rt_free();
#ifdef CONFIG_SYSCTL
nr_unregister_sysctl();
#endif
ax25_linkfail_release(&nr_linkfail_notifier);
ax25_protocol_release(AX25_P_NETROM);
unregister_netdevice_notifier(&nr_dev_notifier);
sock_unregister(PF_NETROM);
for (i = 0; i < nr_ndevs; i++) {
struct net_device *dev = dev_nr[i];
if (dev) {
unregister_netdev(dev);
free_netdev(dev);
}
}
kfree(dev_nr);
proto_unregister(&nr_proto);
}
module_exit(nr_exit);
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