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linux/net/atm/svc.c
Stefan Hajnoczi c685293aa3 net/atm: sk_err_soft must be positive 
The sk_err and sk_err_soft fields are positive errno values and
userspace applications rely on this when using getsockopt(SO_ERROR).

ATM code places an -errno into sk_err_soft in sigd_send() and returns it
from svc_addparty()/svc_dropparty().

Although I am not familiar with ATM code I came to this conclusion
because:

1. sigd_send() msg->type cases as_okay and as_error both have:

   sk->sk_err = -msg->reply;

   while the as_addparty and as_dropparty cases have:

   sk->sk_err_soft = msg->reply;

   This is the source of the inconsistency.

2. svc_addparty() returns an -errno and assumes sk_err_soft is also an
   -errno:

       if (flags & O_NONBLOCK) {
           error = -EINPROGRESS;
           goto out;
       }
       ...
       error = xchg(&sk->sk_err_soft, 0);
   out:
       release_sock(sk);
       return error;

   This shows that sk_err_soft is indeed being treated as an -errno.

This patch ensures that sk_err_soft is always a positive errno.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-05-23 13:51:10 -07:00

691 lines
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/* net/atm/svc.c - ATM SVC sockets */
/* Written 1995-2000 by Werner Almesberger, EPFL LRC/ICA */
#define pr_fmt(fmt) KBUILD_MODNAME ":%s: " fmt, __func__
#include <linux/string.h>
#include <linux/net.h> /* struct socket, struct proto_ops */
#include <linux/errno.h> /* error codes */
#include <linux/kernel.h> /* printk */
#include <linux/skbuff.h>
#include <linux/wait.h>
#include <linux/sched.h> /* jiffies and HZ */
#include <linux/fcntl.h> /* O_NONBLOCK */
#include <linux/init.h>
#include <linux/atm.h> /* ATM stuff */
#include <linux/atmsap.h>
#include <linux/atmsvc.h>
#include <linux/atmdev.h>
#include <linux/bitops.h>
#include <net/sock.h> /* for sock_no_* */
#include <linux/uaccess.h>
#include <linux/export.h>
#include "resources.h"
#include "common.h" /* common for PVCs and SVCs */
#include "signaling.h"
#include "addr.h"
static int svc_create(struct net *net, struct socket *sock, int protocol,
int kern);
/*
* Note: since all this is still nicely synchronized with the signaling demon,
* there's no need to protect sleep loops with clis. If signaling is
* moved into the kernel, that would change.
*/
static int svc_shutdown(struct socket *sock, int how)
{
return 0;
}
static void svc_disconnect(struct atm_vcc *vcc)
{
DEFINE_WAIT(wait);
struct sk_buff *skb;
struct sock *sk = sk_atm(vcc);
pr_debug("%p\n", vcc);
if (test_bit(ATM_VF_REGIS, &vcc->flags)) {
sigd_enq(vcc, as_close, NULL, NULL, NULL);
for (;;) {
prepare_to_wait(sk_sleep(sk), &wait, TASK_UNINTERRUPTIBLE);
if (test_bit(ATM_VF_RELEASED, &vcc->flags) || !sigd)
break;
schedule();
}
finish_wait(sk_sleep(sk), &wait);
}
/* beware - socket is still in use by atmsigd until the last
as_indicate has been answered */
while ((skb = skb_dequeue(&sk->sk_receive_queue)) != NULL) {
atm_return(vcc, skb->truesize);
pr_debug("LISTEN REL\n");
sigd_enq2(NULL, as_reject, vcc, NULL, NULL, &vcc->qos, 0);
dev_kfree_skb(skb);
}
clear_bit(ATM_VF_REGIS, &vcc->flags);
/* ... may retry later */
}
static int svc_release(struct socket *sock)
{
struct sock *sk = sock->sk;
struct atm_vcc *vcc;
if (sk) {
vcc = ATM_SD(sock);
pr_debug("%p\n", vcc);
clear_bit(ATM_VF_READY, &vcc->flags);
/*
* VCC pointer is used as a reference,
* so we must not free it (thereby subjecting it to re-use)
* before all pending connections are closed
*/
svc_disconnect(vcc);
vcc_release(sock);
}
return 0;
}
static int svc_bind(struct socket *sock, struct sockaddr *sockaddr,
int sockaddr_len)
{
DEFINE_WAIT(wait);
struct sock *sk = sock->sk;
struct sockaddr_atmsvc *addr;
struct atm_vcc *vcc;
int error;
if (sockaddr_len != sizeof(struct sockaddr_atmsvc))
return -EINVAL;
lock_sock(sk);
if (sock->state == SS_CONNECTED) {
error = -EISCONN;
goto out;
}
if (sock->state != SS_UNCONNECTED) {
error = -EINVAL;
goto out;
}
vcc = ATM_SD(sock);
addr = (struct sockaddr_atmsvc *) sockaddr;
if (addr->sas_family != AF_ATMSVC) {
error = -EAFNOSUPPORT;
goto out;
}
clear_bit(ATM_VF_BOUND, &vcc->flags);
/* failing rebind will kill old binding */
/* @@@ check memory (de)allocation on rebind */
if (!test_bit(ATM_VF_HASQOS, &vcc->flags)) {
error = -EBADFD;
goto out;
}
vcc->local = *addr;
set_bit(ATM_VF_WAITING, &vcc->flags);
sigd_enq(vcc, as_bind, NULL, NULL, &vcc->local);
for (;;) {
prepare_to_wait(sk_sleep(sk), &wait, TASK_UNINTERRUPTIBLE);
if (!test_bit(ATM_VF_WAITING, &vcc->flags) || !sigd)
break;
schedule();
}
finish_wait(sk_sleep(sk), &wait);
clear_bit(ATM_VF_REGIS, &vcc->flags); /* doesn't count */
if (!sigd) {
error = -EUNATCH;
goto out;
}
if (!sk->sk_err)
set_bit(ATM_VF_BOUND, &vcc->flags);
error = -sk->sk_err;
out:
release_sock(sk);
return error;
}
static int svc_connect(struct socket *sock, struct sockaddr *sockaddr,
int sockaddr_len, int flags)
{
DEFINE_WAIT(wait);
struct sock *sk = sock->sk;
struct sockaddr_atmsvc *addr;
struct atm_vcc *vcc = ATM_SD(sock);
int error;
pr_debug("%p\n", vcc);
lock_sock(sk);
if (sockaddr_len != sizeof(struct sockaddr_atmsvc)) {
error = -EINVAL;
goto out;
}
switch (sock->state) {
default:
error = -EINVAL;
goto out;
case SS_CONNECTED:
error = -EISCONN;
goto out;
case SS_CONNECTING:
if (test_bit(ATM_VF_WAITING, &vcc->flags)) {
error = -EALREADY;
goto out;
}
sock->state = SS_UNCONNECTED;
if (sk->sk_err) {
error = -sk->sk_err;
goto out;
}
break;
case SS_UNCONNECTED:
addr = (struct sockaddr_atmsvc *) sockaddr;
if (addr->sas_family != AF_ATMSVC) {
error = -EAFNOSUPPORT;
goto out;
}
if (!test_bit(ATM_VF_HASQOS, &vcc->flags)) {
error = -EBADFD;
goto out;
}
if (vcc->qos.txtp.traffic_class == ATM_ANYCLASS ||
vcc->qos.rxtp.traffic_class == ATM_ANYCLASS) {
error = -EINVAL;
goto out;
}
if (!vcc->qos.txtp.traffic_class &&
!vcc->qos.rxtp.traffic_class) {
error = -EINVAL;
goto out;
}
vcc->remote = *addr;
set_bit(ATM_VF_WAITING, &vcc->flags);
sigd_enq(vcc, as_connect, NULL, NULL, &vcc->remote);
if (flags & O_NONBLOCK) {
sock->state = SS_CONNECTING;
error = -EINPROGRESS;
goto out;
}
error = 0;
prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
while (test_bit(ATM_VF_WAITING, &vcc->flags) && sigd) {
schedule();
if (!signal_pending(current)) {
prepare_to_wait(sk_sleep(sk), &wait,
TASK_INTERRUPTIBLE);
continue;
}
pr_debug("*ABORT*\n");
/*
* This is tricky:
* Kernel ---close--> Demon
* Kernel <--close--- Demon
* or
* Kernel ---close--> Demon
* Kernel <--error--- Demon
* or
* Kernel ---close--> Demon
* Kernel <--okay---- Demon
* Kernel <--close--- Demon
*/
sigd_enq(vcc, as_close, NULL, NULL, NULL);
while (test_bit(ATM_VF_WAITING, &vcc->flags) && sigd) {
prepare_to_wait(sk_sleep(sk), &wait,
TASK_INTERRUPTIBLE);
schedule();
}
if (!sk->sk_err)
while (!test_bit(ATM_VF_RELEASED, &vcc->flags) &&
sigd) {
prepare_to_wait(sk_sleep(sk), &wait,
TASK_INTERRUPTIBLE);
schedule();
}
clear_bit(ATM_VF_REGIS, &vcc->flags);
clear_bit(ATM_VF_RELEASED, &vcc->flags);
clear_bit(ATM_VF_CLOSE, &vcc->flags);
/* we're gone now but may connect later */
error = -EINTR;
break;
}
finish_wait(sk_sleep(sk), &wait);
if (error)
goto out;
if (!sigd) {
error = -EUNATCH;
goto out;
}
if (sk->sk_err) {
error = -sk->sk_err;
goto out;
}
}
vcc->qos.txtp.max_pcr = SELECT_TOP_PCR(vcc->qos.txtp);
vcc->qos.txtp.pcr = 0;
vcc->qos.txtp.min_pcr = 0;
error = vcc_connect(sock, vcc->itf, vcc->vpi, vcc->vci);
if (!error)
sock->state = SS_CONNECTED;
else
(void)svc_disconnect(vcc);
out:
release_sock(sk);
return error;
}
static int svc_listen(struct socket *sock, int backlog)
{
DEFINE_WAIT(wait);
struct sock *sk = sock->sk;
struct atm_vcc *vcc = ATM_SD(sock);
int error;
pr_debug("%p\n", vcc);
lock_sock(sk);
/* let server handle listen on unbound sockets */
if (test_bit(ATM_VF_SESSION, &vcc->flags)) {
error = -EINVAL;
goto out;
}
if (test_bit(ATM_VF_LISTEN, &vcc->flags)) {
error = -EADDRINUSE;
goto out;
}
set_bit(ATM_VF_WAITING, &vcc->flags);
sigd_enq(vcc, as_listen, NULL, NULL, &vcc->local);
for (;;) {
prepare_to_wait(sk_sleep(sk), &wait, TASK_UNINTERRUPTIBLE);
if (!test_bit(ATM_VF_WAITING, &vcc->flags) || !sigd)
break;
schedule();
}
finish_wait(sk_sleep(sk), &wait);
if (!sigd) {
error = -EUNATCH;
goto out;
}
set_bit(ATM_VF_LISTEN, &vcc->flags);
vcc_insert_socket(sk);
sk->sk_max_ack_backlog = backlog > 0 ? backlog : ATM_BACKLOG_DEFAULT;
error = -sk->sk_err;
out:
release_sock(sk);
return error;
}
static int svc_accept(struct socket *sock, struct socket *newsock, int flags)
{
struct sock *sk = sock->sk;
struct sk_buff *skb;
struct atmsvc_msg *msg;
struct atm_vcc *old_vcc = ATM_SD(sock);
struct atm_vcc *new_vcc;
int error;
lock_sock(sk);
error = svc_create(sock_net(sk), newsock, 0, 0);
if (error)
goto out;
new_vcc = ATM_SD(newsock);
pr_debug("%p -> %p\n", old_vcc, new_vcc);
while (1) {
DEFINE_WAIT(wait);
prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
while (!(skb = skb_dequeue(&sk->sk_receive_queue)) &&
sigd) {
if (test_bit(ATM_VF_RELEASED, &old_vcc->flags))
break;
if (test_bit(ATM_VF_CLOSE, &old_vcc->flags)) {
error = -sk->sk_err;
break;
}
if (flags & O_NONBLOCK) {
error = -EAGAIN;
break;
}
release_sock(sk);
schedule();
lock_sock(sk);
if (signal_pending(current)) {
error = -ERESTARTSYS;
break;
}
prepare_to_wait(sk_sleep(sk), &wait,
TASK_INTERRUPTIBLE);
}
finish_wait(sk_sleep(sk), &wait);
if (error)
goto out;
if (!skb) {
error = -EUNATCH;
goto out;
}
msg = (struct atmsvc_msg *)skb->data;
new_vcc->qos = msg->qos;
set_bit(ATM_VF_HASQOS, &new_vcc->flags);
new_vcc->remote = msg->svc;
new_vcc->local = msg->local;
new_vcc->sap = msg->sap;
error = vcc_connect(newsock, msg->pvc.sap_addr.itf,
msg->pvc.sap_addr.vpi,
msg->pvc.sap_addr.vci);
dev_kfree_skb(skb);
sk->sk_ack_backlog--;
if (error) {
sigd_enq2(NULL, as_reject, old_vcc, NULL, NULL,
&old_vcc->qos, error);
error = error == -EAGAIN ? -EBUSY : error;
goto out;
}
/* wait should be short, so we ignore the non-blocking flag */
set_bit(ATM_VF_WAITING, &new_vcc->flags);
sigd_enq(new_vcc, as_accept, old_vcc, NULL, NULL);
for (;;) {
prepare_to_wait(sk_sleep(sk_atm(new_vcc)), &wait,
TASK_UNINTERRUPTIBLE);
if (!test_bit(ATM_VF_WAITING, &new_vcc->flags) || !sigd)
break;
release_sock(sk);
schedule();
lock_sock(sk);
}
finish_wait(sk_sleep(sk_atm(new_vcc)), &wait);
if (!sigd) {
error = -EUNATCH;
goto out;
}
if (!sk_atm(new_vcc)->sk_err)
break;
if (sk_atm(new_vcc)->sk_err != ERESTARTSYS) {
error = -sk_atm(new_vcc)->sk_err;
goto out;
}
}
newsock->state = SS_CONNECTED;
out:
release_sock(sk);
return error;
}
static int svc_getname(struct socket *sock, struct sockaddr *sockaddr,
int *sockaddr_len, int peer)
{
struct sockaddr_atmsvc *addr;
*sockaddr_len = sizeof(struct sockaddr_atmsvc);
addr = (struct sockaddr_atmsvc *) sockaddr;
memcpy(addr, peer ? &ATM_SD(sock)->remote : &ATM_SD(sock)->local,
sizeof(struct sockaddr_atmsvc));
return 0;
}
int svc_change_qos(struct atm_vcc *vcc, struct atm_qos *qos)
{
struct sock *sk = sk_atm(vcc);
DEFINE_WAIT(wait);
set_bit(ATM_VF_WAITING, &vcc->flags);
sigd_enq2(vcc, as_modify, NULL, NULL, &vcc->local, qos, 0);
for (;;) {
prepare_to_wait(sk_sleep(sk), &wait, TASK_UNINTERRUPTIBLE);
if (!test_bit(ATM_VF_WAITING, &vcc->flags) ||
test_bit(ATM_VF_RELEASED, &vcc->flags) || !sigd) {
break;
}
schedule();
}
finish_wait(sk_sleep(sk), &wait);
if (!sigd)
return -EUNATCH;
return -sk->sk_err;
}
static int svc_setsockopt(struct socket *sock, int level, int optname,
char __user *optval, unsigned int optlen)
{
struct sock *sk = sock->sk;
struct atm_vcc *vcc = ATM_SD(sock);
int value, error = 0;
lock_sock(sk);
switch (optname) {
case SO_ATMSAP:
if (level != SOL_ATM || optlen != sizeof(struct atm_sap)) {
error = -EINVAL;
goto out;
}
if (copy_from_user(&vcc->sap, optval, optlen)) {
error = -EFAULT;
goto out;
}
set_bit(ATM_VF_HASSAP, &vcc->flags);
break;
case SO_MULTIPOINT:
if (level != SOL_ATM || optlen != sizeof(int)) {
error = -EINVAL;
goto out;
}
if (get_user(value, (int __user *)optval)) {
error = -EFAULT;
goto out;
}
if (value == 1)
set_bit(ATM_VF_SESSION, &vcc->flags);
else if (value == 0)
clear_bit(ATM_VF_SESSION, &vcc->flags);
else
error = -EINVAL;
break;
default:
error = vcc_setsockopt(sock, level, optname, optval, optlen);
}
out:
release_sock(sk);
return error;
}
static int svc_getsockopt(struct socket *sock, int level, int optname,
char __user *optval, int __user *optlen)
{
struct sock *sk = sock->sk;
int error = 0, len;
lock_sock(sk);
if (!__SO_LEVEL_MATCH(optname, level) || optname != SO_ATMSAP) {
error = vcc_getsockopt(sock, level, optname, optval, optlen);
goto out;
}
if (get_user(len, optlen)) {
error = -EFAULT;
goto out;
}
if (len != sizeof(struct atm_sap)) {
error = -EINVAL;
goto out;
}
if (copy_to_user(optval, &ATM_SD(sock)->sap, sizeof(struct atm_sap))) {
error = -EFAULT;
goto out;
}
out:
release_sock(sk);
return error;
}
static int svc_addparty(struct socket *sock, struct sockaddr *sockaddr,
int sockaddr_len, int flags)
{
DEFINE_WAIT(wait);
struct sock *sk = sock->sk;
struct atm_vcc *vcc = ATM_SD(sock);
int error;
lock_sock(sk);
set_bit(ATM_VF_WAITING, &vcc->flags);
sigd_enq(vcc, as_addparty, NULL, NULL,
(struct sockaddr_atmsvc *) sockaddr);
if (flags & O_NONBLOCK) {
error = -EINPROGRESS;
goto out;
}
pr_debug("added wait queue\n");
for (;;) {
prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
if (!test_bit(ATM_VF_WAITING, &vcc->flags) || !sigd)
break;
schedule();
}
finish_wait(sk_sleep(sk), &wait);
error = -xchg(&sk->sk_err_soft, 0);
out:
release_sock(sk);
return error;
}
static int svc_dropparty(struct socket *sock, int ep_ref)
{
DEFINE_WAIT(wait);
struct sock *sk = sock->sk;
struct atm_vcc *vcc = ATM_SD(sock);
int error;
lock_sock(sk);
set_bit(ATM_VF_WAITING, &vcc->flags);
sigd_enq2(vcc, as_dropparty, NULL, NULL, NULL, NULL, ep_ref);
for (;;) {
prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
if (!test_bit(ATM_VF_WAITING, &vcc->flags) || !sigd)
break;
schedule();
}
finish_wait(sk_sleep(sk), &wait);
if (!sigd) {
error = -EUNATCH;
goto out;
}
error = -xchg(&sk->sk_err_soft, 0);
out:
release_sock(sk);
return error;
}
static int svc_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
{
int error, ep_ref;
struct sockaddr_atmsvc sa;
struct atm_vcc *vcc = ATM_SD(sock);
switch (cmd) {
case ATM_ADDPARTY:
if (!test_bit(ATM_VF_SESSION, &vcc->flags))
return -EINVAL;
if (copy_from_user(&sa, (void __user *) arg, sizeof(sa)))
return -EFAULT;
error = svc_addparty(sock, (struct sockaddr *)&sa, sizeof(sa),
0);
break;
case ATM_DROPPARTY:
if (!test_bit(ATM_VF_SESSION, &vcc->flags))
return -EINVAL;
if (copy_from_user(&ep_ref, (void __user *) arg, sizeof(int)))
return -EFAULT;
error = svc_dropparty(sock, ep_ref);
break;
default:
error = vcc_ioctl(sock, cmd, arg);
}
return error;
}
#ifdef CONFIG_COMPAT
static int svc_compat_ioctl(struct socket *sock, unsigned int cmd,
unsigned long arg)
{
/* The definition of ATM_ADDPARTY uses the size of struct atm_iobuf.
But actually it takes a struct sockaddr_atmsvc, which doesn't need
compat handling. So all we have to do is fix up cmd... */
if (cmd == COMPAT_ATM_ADDPARTY)
cmd = ATM_ADDPARTY;
if (cmd == ATM_ADDPARTY || cmd == ATM_DROPPARTY)
return svc_ioctl(sock, cmd, arg);
else
return vcc_compat_ioctl(sock, cmd, arg);
}
#endif /* CONFIG_COMPAT */
static const struct proto_ops svc_proto_ops = {
.family = PF_ATMSVC,
.owner = THIS_MODULE,
.release = svc_release,
.bind = svc_bind,
.connect = svc_connect,
.socketpair = sock_no_socketpair,
.accept = svc_accept,
.getname = svc_getname,
.poll = vcc_poll,
.ioctl = svc_ioctl,
#ifdef CONFIG_COMPAT
.compat_ioctl = svc_compat_ioctl,
#endif
.listen = svc_listen,
.shutdown = svc_shutdown,
.setsockopt = svc_setsockopt,
.getsockopt = svc_getsockopt,
.sendmsg = vcc_sendmsg,
.recvmsg = vcc_recvmsg,
.mmap = sock_no_mmap,
.sendpage = sock_no_sendpage,
};
static int svc_create(struct net *net, struct socket *sock, int protocol,
int kern)
{
int error;
if (!net_eq(net, &init_net))
return -EAFNOSUPPORT;
sock->ops = &svc_proto_ops;
error = vcc_create(net, sock, protocol, AF_ATMSVC, kern);
if (error)
return error;
ATM_SD(sock)->local.sas_family = AF_ATMSVC;
ATM_SD(sock)->remote.sas_family = AF_ATMSVC;
return 0;
}
static const struct net_proto_family svc_family_ops = {
.family = PF_ATMSVC,
.create = svc_create,
.owner = THIS_MODULE,
};
/*
* Initialize the ATM SVC protocol family
*/
int __init atmsvc_init(void)
{
return sock_register(&svc_family_ops);
}
void atmsvc_exit(void)
{
sock_unregister(PF_ATMSVC);
}
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