linux/net/iucv/af_iucv.c
Hendrik Brueckner 3fa6b5adbe af_iucv: Fix race when queuing incoming iucv messages
AF_IUCV runs into a race when queuing incoming iucv messages
and receiving the resulting backlog.

If the Linux system is under pressure (high load or steal time),
the message queue grows up, but messages are not received and queued
onto the backlog queue. In that case, applications do not
receive any data with recvmsg() even if AF_IUCV puts incoming
messages onto the message queue.

The race can be avoided if the message queue spinlock in the
message_pending callback is spreaded across the entire callback
function.

Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Ursula Braun <ursula.braun@de.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-04-21 23:43:15 -07:00

1286 lines
27 KiB
C

/*
* linux/net/iucv/af_iucv.c
*
* IUCV protocol stack for Linux on zSeries
*
* Copyright 2006 IBM Corporation
*
* Author(s): Jennifer Hunt <jenhunt@us.ibm.com>
*/
#define KMSG_COMPONENT "af_iucv"
#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
#include <linux/module.h>
#include <linux/types.h>
#include <linux/list.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/skbuff.h>
#include <linux/init.h>
#include <linux/poll.h>
#include <net/sock.h>
#include <asm/ebcdic.h>
#include <asm/cpcmd.h>
#include <linux/kmod.h>
#include <net/iucv/iucv.h>
#include <net/iucv/af_iucv.h>
#define CONFIG_IUCV_SOCK_DEBUG 1
#define IPRMDATA 0x80
#define VERSION "1.0"
static char iucv_userid[80];
static struct proto_ops iucv_sock_ops;
static struct proto iucv_proto = {
.name = "AF_IUCV",
.owner = THIS_MODULE,
.obj_size = sizeof(struct iucv_sock),
};
static void iucv_sock_kill(struct sock *sk);
static void iucv_sock_close(struct sock *sk);
/* Call Back functions */
static void iucv_callback_rx(struct iucv_path *, struct iucv_message *);
static void iucv_callback_txdone(struct iucv_path *, struct iucv_message *);
static void iucv_callback_connack(struct iucv_path *, u8 ipuser[16]);
static int iucv_callback_connreq(struct iucv_path *, u8 ipvmid[8],
u8 ipuser[16]);
static void iucv_callback_connrej(struct iucv_path *, u8 ipuser[16]);
static struct iucv_sock_list iucv_sk_list = {
.lock = __RW_LOCK_UNLOCKED(iucv_sk_list.lock),
.autobind_name = ATOMIC_INIT(0)
};
static struct iucv_handler af_iucv_handler = {
.path_pending = iucv_callback_connreq,
.path_complete = iucv_callback_connack,
.path_severed = iucv_callback_connrej,
.message_pending = iucv_callback_rx,
.message_complete = iucv_callback_txdone
};
static inline void high_nmcpy(unsigned char *dst, char *src)
{
memcpy(dst, src, 8);
}
static inline void low_nmcpy(unsigned char *dst, char *src)
{
memcpy(&dst[8], src, 8);
}
/* Timers */
static void iucv_sock_timeout(unsigned long arg)
{
struct sock *sk = (struct sock *)arg;
bh_lock_sock(sk);
sk->sk_err = ETIMEDOUT;
sk->sk_state_change(sk);
bh_unlock_sock(sk);
iucv_sock_kill(sk);
sock_put(sk);
}
static void iucv_sock_clear_timer(struct sock *sk)
{
sk_stop_timer(sk, &sk->sk_timer);
}
static struct sock *__iucv_get_sock_by_name(char *nm)
{
struct sock *sk;
struct hlist_node *node;
sk_for_each(sk, node, &iucv_sk_list.head)
if (!memcmp(&iucv_sk(sk)->src_name, nm, 8))
return sk;
return NULL;
}
static void iucv_sock_destruct(struct sock *sk)
{
skb_queue_purge(&sk->sk_receive_queue);
skb_queue_purge(&sk->sk_write_queue);
}
/* Cleanup Listen */
static void iucv_sock_cleanup_listen(struct sock *parent)
{
struct sock *sk;
/* Close non-accepted connections */
while ((sk = iucv_accept_dequeue(parent, NULL))) {
iucv_sock_close(sk);
iucv_sock_kill(sk);
}
parent->sk_state = IUCV_CLOSED;
sock_set_flag(parent, SOCK_ZAPPED);
}
/* Kill socket */
static void iucv_sock_kill(struct sock *sk)
{
if (!sock_flag(sk, SOCK_ZAPPED) || sk->sk_socket)
return;
iucv_sock_unlink(&iucv_sk_list, sk);
sock_set_flag(sk, SOCK_DEAD);
sock_put(sk);
}
/* Close an IUCV socket */
static void iucv_sock_close(struct sock *sk)
{
unsigned char user_data[16];
struct iucv_sock *iucv = iucv_sk(sk);
int err;
unsigned long timeo;
iucv_sock_clear_timer(sk);
lock_sock(sk);
switch (sk->sk_state) {
case IUCV_LISTEN:
iucv_sock_cleanup_listen(sk);
break;
case IUCV_CONNECTED:
case IUCV_DISCONN:
err = 0;
sk->sk_state = IUCV_CLOSING;
sk->sk_state_change(sk);
if (!skb_queue_empty(&iucv->send_skb_q)) {
if (sock_flag(sk, SOCK_LINGER) && sk->sk_lingertime)
timeo = sk->sk_lingertime;
else
timeo = IUCV_DISCONN_TIMEOUT;
err = iucv_sock_wait_state(sk, IUCV_CLOSED, 0, timeo);
}
case IUCV_CLOSING: /* fall through */
sk->sk_state = IUCV_CLOSED;
sk->sk_state_change(sk);
if (iucv->path) {
low_nmcpy(user_data, iucv->src_name);
high_nmcpy(user_data, iucv->dst_name);
ASCEBC(user_data, sizeof(user_data));
err = iucv_path_sever(iucv->path, user_data);
iucv_path_free(iucv->path);
iucv->path = NULL;
}
sk->sk_err = ECONNRESET;
sk->sk_state_change(sk);
skb_queue_purge(&iucv->send_skb_q);
skb_queue_purge(&iucv->backlog_skb_q);
sock_set_flag(sk, SOCK_ZAPPED);
break;
default:
sock_set_flag(sk, SOCK_ZAPPED);
break;
}
release_sock(sk);
iucv_sock_kill(sk);
}
static void iucv_sock_init(struct sock *sk, struct sock *parent)
{
if (parent)
sk->sk_type = parent->sk_type;
}
static struct sock *iucv_sock_alloc(struct socket *sock, int proto, gfp_t prio)
{
struct sock *sk;
sk = sk_alloc(&init_net, PF_IUCV, prio, &iucv_proto);
if (!sk)
return NULL;
sock_init_data(sock, sk);
INIT_LIST_HEAD(&iucv_sk(sk)->accept_q);
spin_lock_init(&iucv_sk(sk)->accept_q_lock);
skb_queue_head_init(&iucv_sk(sk)->send_skb_q);
INIT_LIST_HEAD(&iucv_sk(sk)->message_q.list);
spin_lock_init(&iucv_sk(sk)->message_q.lock);
skb_queue_head_init(&iucv_sk(sk)->backlog_skb_q);
iucv_sk(sk)->send_tag = 0;
iucv_sk(sk)->path = NULL;
memset(&iucv_sk(sk)->src_user_id , 0, 32);
sk->sk_destruct = iucv_sock_destruct;
sk->sk_sndtimeo = IUCV_CONN_TIMEOUT;
sk->sk_allocation = GFP_DMA;
sock_reset_flag(sk, SOCK_ZAPPED);
sk->sk_protocol = proto;
sk->sk_state = IUCV_OPEN;
setup_timer(&sk->sk_timer, iucv_sock_timeout, (unsigned long)sk);
iucv_sock_link(&iucv_sk_list, sk);
return sk;
}
/* Create an IUCV socket */
static int iucv_sock_create(struct net *net, struct socket *sock, int protocol)
{
struct sock *sk;
if (sock->type != SOCK_STREAM)
return -ESOCKTNOSUPPORT;
sock->state = SS_UNCONNECTED;
sock->ops = &iucv_sock_ops;
sk = iucv_sock_alloc(sock, protocol, GFP_KERNEL);
if (!sk)
return -ENOMEM;
iucv_sock_init(sk, NULL);
return 0;
}
void iucv_sock_link(struct iucv_sock_list *l, struct sock *sk)
{
write_lock_bh(&l->lock);
sk_add_node(sk, &l->head);
write_unlock_bh(&l->lock);
}
void iucv_sock_unlink(struct iucv_sock_list *l, struct sock *sk)
{
write_lock_bh(&l->lock);
sk_del_node_init(sk);
write_unlock_bh(&l->lock);
}
void iucv_accept_enqueue(struct sock *parent, struct sock *sk)
{
unsigned long flags;
struct iucv_sock *par = iucv_sk(parent);
sock_hold(sk);
spin_lock_irqsave(&par->accept_q_lock, flags);
list_add_tail(&iucv_sk(sk)->accept_q, &par->accept_q);
spin_unlock_irqrestore(&par->accept_q_lock, flags);
iucv_sk(sk)->parent = parent;
parent->sk_ack_backlog++;
}
void iucv_accept_unlink(struct sock *sk)
{
unsigned long flags;
struct iucv_sock *par = iucv_sk(iucv_sk(sk)->parent);
spin_lock_irqsave(&par->accept_q_lock, flags);
list_del_init(&iucv_sk(sk)->accept_q);
spin_unlock_irqrestore(&par->accept_q_lock, flags);
iucv_sk(sk)->parent->sk_ack_backlog--;
iucv_sk(sk)->parent = NULL;
sock_put(sk);
}
struct sock *iucv_accept_dequeue(struct sock *parent, struct socket *newsock)
{
struct iucv_sock *isk, *n;
struct sock *sk;
list_for_each_entry_safe(isk, n, &iucv_sk(parent)->accept_q, accept_q) {
sk = (struct sock *) isk;
lock_sock(sk);
if (sk->sk_state == IUCV_CLOSED) {
iucv_accept_unlink(sk);
release_sock(sk);
continue;
}
if (sk->sk_state == IUCV_CONNECTED ||
sk->sk_state == IUCV_SEVERED ||
!newsock) {
iucv_accept_unlink(sk);
if (newsock)
sock_graft(sk, newsock);
if (sk->sk_state == IUCV_SEVERED)
sk->sk_state = IUCV_DISCONN;
release_sock(sk);
return sk;
}
release_sock(sk);
}
return NULL;
}
int iucv_sock_wait_state(struct sock *sk, int state, int state2,
unsigned long timeo)
{
DECLARE_WAITQUEUE(wait, current);
int err = 0;
add_wait_queue(sk->sk_sleep, &wait);
while (sk->sk_state != state && sk->sk_state != state2) {
set_current_state(TASK_INTERRUPTIBLE);
if (!timeo) {
err = -EAGAIN;
break;
}
if (signal_pending(current)) {
err = sock_intr_errno(timeo);
break;
}
release_sock(sk);
timeo = schedule_timeout(timeo);
lock_sock(sk);
err = sock_error(sk);
if (err)
break;
}
set_current_state(TASK_RUNNING);
remove_wait_queue(sk->sk_sleep, &wait);
return err;
}
/* Bind an unbound socket */
static int iucv_sock_bind(struct socket *sock, struct sockaddr *addr,
int addr_len)
{
struct sockaddr_iucv *sa = (struct sockaddr_iucv *) addr;
struct sock *sk = sock->sk;
struct iucv_sock *iucv;
int err;
/* Verify the input sockaddr */
if (!addr || addr->sa_family != AF_IUCV)
return -EINVAL;
lock_sock(sk);
if (sk->sk_state != IUCV_OPEN) {
err = -EBADFD;
goto done;
}
write_lock_bh(&iucv_sk_list.lock);
iucv = iucv_sk(sk);
if (__iucv_get_sock_by_name(sa->siucv_name)) {
err = -EADDRINUSE;
goto done_unlock;
}
if (iucv->path) {
err = 0;
goto done_unlock;
}
/* Bind the socket */
memcpy(iucv->src_name, sa->siucv_name, 8);
/* Copy the user id */
memcpy(iucv->src_user_id, iucv_userid, 8);
sk->sk_state = IUCV_BOUND;
err = 0;
done_unlock:
/* Release the socket list lock */
write_unlock_bh(&iucv_sk_list.lock);
done:
release_sock(sk);
return err;
}
/* Automatically bind an unbound socket */
static int iucv_sock_autobind(struct sock *sk)
{
struct iucv_sock *iucv = iucv_sk(sk);
char query_buffer[80];
char name[12];
int err = 0;
/* Set the userid and name */
cpcmd("QUERY USERID", query_buffer, sizeof(query_buffer), &err);
if (unlikely(err))
return -EPROTO;
memcpy(iucv->src_user_id, query_buffer, 8);
write_lock_bh(&iucv_sk_list.lock);
sprintf(name, "%08x", atomic_inc_return(&iucv_sk_list.autobind_name));
while (__iucv_get_sock_by_name(name)) {
sprintf(name, "%08x",
atomic_inc_return(&iucv_sk_list.autobind_name));
}
write_unlock_bh(&iucv_sk_list.lock);
memcpy(&iucv->src_name, name, 8);
return err;
}
/* Connect an unconnected socket */
static int iucv_sock_connect(struct socket *sock, struct sockaddr *addr,
int alen, int flags)
{
struct sockaddr_iucv *sa = (struct sockaddr_iucv *) addr;
struct sock *sk = sock->sk;
struct iucv_sock *iucv;
unsigned char user_data[16];
int err;
if (addr->sa_family != AF_IUCV || alen < sizeof(struct sockaddr_iucv))
return -EINVAL;
if (sk->sk_state != IUCV_OPEN && sk->sk_state != IUCV_BOUND)
return -EBADFD;
if (sk->sk_type != SOCK_STREAM)
return -EINVAL;
iucv = iucv_sk(sk);
if (sk->sk_state == IUCV_OPEN) {
err = iucv_sock_autobind(sk);
if (unlikely(err))
return err;
}
lock_sock(sk);
/* Set the destination information */
memcpy(iucv_sk(sk)->dst_user_id, sa->siucv_user_id, 8);
memcpy(iucv_sk(sk)->dst_name, sa->siucv_name, 8);
high_nmcpy(user_data, sa->siucv_name);
low_nmcpy(user_data, iucv_sk(sk)->src_name);
ASCEBC(user_data, sizeof(user_data));
iucv = iucv_sk(sk);
/* Create path. */
iucv->path = iucv_path_alloc(IUCV_QUEUELEN_DEFAULT,
IPRMDATA, GFP_KERNEL);
if (!iucv->path) {
err = -ENOMEM;
goto done;
}
err = iucv_path_connect(iucv->path, &af_iucv_handler,
sa->siucv_user_id, NULL, user_data, sk);
if (err) {
iucv_path_free(iucv->path);
iucv->path = NULL;
switch (err) {
case 0x0b: /* Target communicator is not logged on */
err = -ENETUNREACH;
break;
case 0x0d: /* Max connections for this guest exceeded */
case 0x0e: /* Max connections for target guest exceeded */
err = -EAGAIN;
break;
case 0x0f: /* Missing IUCV authorization */
err = -EACCES;
break;
default:
err = -ECONNREFUSED;
break;
}
goto done;
}
if (sk->sk_state != IUCV_CONNECTED) {
err = iucv_sock_wait_state(sk, IUCV_CONNECTED, IUCV_DISCONN,
sock_sndtimeo(sk, flags & O_NONBLOCK));
}
if (sk->sk_state == IUCV_DISCONN) {
release_sock(sk);
return -ECONNREFUSED;
}
if (err) {
iucv_path_sever(iucv->path, NULL);
iucv_path_free(iucv->path);
iucv->path = NULL;
}
done:
release_sock(sk);
return err;
}
/* Move a socket into listening state. */
static int iucv_sock_listen(struct socket *sock, int backlog)
{
struct sock *sk = sock->sk;
int err;
lock_sock(sk);
err = -EINVAL;
if (sk->sk_state != IUCV_BOUND || sock->type != SOCK_STREAM)
goto done;
sk->sk_max_ack_backlog = backlog;
sk->sk_ack_backlog = 0;
sk->sk_state = IUCV_LISTEN;
err = 0;
done:
release_sock(sk);
return err;
}
/* Accept a pending connection */
static int iucv_sock_accept(struct socket *sock, struct socket *newsock,
int flags)
{
DECLARE_WAITQUEUE(wait, current);
struct sock *sk = sock->sk, *nsk;
long timeo;
int err = 0;
lock_sock_nested(sk, SINGLE_DEPTH_NESTING);
if (sk->sk_state != IUCV_LISTEN) {
err = -EBADFD;
goto done;
}
timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);
/* Wait for an incoming connection */
add_wait_queue_exclusive(sk->sk_sleep, &wait);
while (!(nsk = iucv_accept_dequeue(sk, newsock))) {
set_current_state(TASK_INTERRUPTIBLE);
if (!timeo) {
err = -EAGAIN;
break;
}
release_sock(sk);
timeo = schedule_timeout(timeo);
lock_sock_nested(sk, SINGLE_DEPTH_NESTING);
if (sk->sk_state != IUCV_LISTEN) {
err = -EBADFD;
break;
}
if (signal_pending(current)) {
err = sock_intr_errno(timeo);
break;
}
}
set_current_state(TASK_RUNNING);
remove_wait_queue(sk->sk_sleep, &wait);
if (err)
goto done;
newsock->state = SS_CONNECTED;
done:
release_sock(sk);
return err;
}
static int iucv_sock_getname(struct socket *sock, struct sockaddr *addr,
int *len, int peer)
{
struct sockaddr_iucv *siucv = (struct sockaddr_iucv *) addr;
struct sock *sk = sock->sk;
addr->sa_family = AF_IUCV;
*len = sizeof(struct sockaddr_iucv);
if (peer) {
memcpy(siucv->siucv_user_id, iucv_sk(sk)->dst_user_id, 8);
memcpy(siucv->siucv_name, &iucv_sk(sk)->dst_name, 8);
} else {
memcpy(siucv->siucv_user_id, iucv_sk(sk)->src_user_id, 8);
memcpy(siucv->siucv_name, iucv_sk(sk)->src_name, 8);
}
memset(&siucv->siucv_port, 0, sizeof(siucv->siucv_port));
memset(&siucv->siucv_addr, 0, sizeof(siucv->siucv_addr));
memset(siucv->siucv_nodeid, 0, sizeof(siucv->siucv_nodeid));
return 0;
}
static int iucv_sock_sendmsg(struct kiocb *iocb, struct socket *sock,
struct msghdr *msg, size_t len)
{
struct sock *sk = sock->sk;
struct iucv_sock *iucv = iucv_sk(sk);
struct sk_buff *skb;
struct iucv_message txmsg;
char user_id[9];
char appl_id[9];
int err;
err = sock_error(sk);
if (err)
return err;
if (msg->msg_flags & MSG_OOB)
return -EOPNOTSUPP;
lock_sock(sk);
if (sk->sk_shutdown & SEND_SHUTDOWN) {
err = -EPIPE;
goto out;
}
if (sk->sk_state == IUCV_CONNECTED) {
if (!(skb = sock_alloc_send_skb(sk, len,
msg->msg_flags & MSG_DONTWAIT,
&err)))
goto out;
if (memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len)) {
err = -EFAULT;
goto fail;
}
txmsg.class = 0;
memcpy(&txmsg.class, skb->data, skb->len >= 4 ? 4 : skb->len);
txmsg.tag = iucv->send_tag++;
memcpy(skb->cb, &txmsg.tag, 4);
skb_queue_tail(&iucv->send_skb_q, skb);
err = iucv_message_send(iucv->path, &txmsg, 0, 0,
(void *) skb->data, skb->len);
if (err) {
if (err == 3) {
user_id[8] = 0;
memcpy(user_id, iucv->dst_user_id, 8);
appl_id[8] = 0;
memcpy(appl_id, iucv->dst_name, 8);
pr_err("Application %s on z/VM guest %s"
" exceeds message limit\n",
user_id, appl_id);
}
skb_unlink(skb, &iucv->send_skb_q);
err = -EPIPE;
goto fail;
}
} else {
err = -ENOTCONN;
goto out;
}
release_sock(sk);
return len;
fail:
kfree_skb(skb);
out:
release_sock(sk);
return err;
}
static int iucv_fragment_skb(struct sock *sk, struct sk_buff *skb, int len)
{
int dataleft, size, copied = 0;
struct sk_buff *nskb;
dataleft = len;
while (dataleft) {
if (dataleft >= sk->sk_rcvbuf / 4)
size = sk->sk_rcvbuf / 4;
else
size = dataleft;
nskb = alloc_skb(size, GFP_ATOMIC | GFP_DMA);
if (!nskb)
return -ENOMEM;
memcpy(nskb->data, skb->data + copied, size);
copied += size;
dataleft -= size;
skb_reset_transport_header(nskb);
skb_reset_network_header(nskb);
nskb->len = size;
skb_queue_tail(&iucv_sk(sk)->backlog_skb_q, nskb);
}
return 0;
}
static void iucv_process_message(struct sock *sk, struct sk_buff *skb,
struct iucv_path *path,
struct iucv_message *msg)
{
int rc;
if (msg->flags & IPRMDATA) {
skb->data = NULL;
skb->len = 0;
} else {
rc = iucv_message_receive(path, msg, 0, skb->data,
msg->length, NULL);
if (rc) {
kfree_skb(skb);
return;
}
if (skb->truesize >= sk->sk_rcvbuf / 4) {
rc = iucv_fragment_skb(sk, skb, msg->length);
kfree_skb(skb);
skb = NULL;
if (rc) {
iucv_path_sever(path, NULL);
return;
}
skb = skb_dequeue(&iucv_sk(sk)->backlog_skb_q);
} else {
skb_reset_transport_header(skb);
skb_reset_network_header(skb);
skb->len = msg->length;
}
}
if (sock_queue_rcv_skb(sk, skb))
skb_queue_head(&iucv_sk(sk)->backlog_skb_q, skb);
}
static void iucv_process_message_q(struct sock *sk)
{
struct iucv_sock *iucv = iucv_sk(sk);
struct sk_buff *skb;
struct sock_msg_q *p, *n;
list_for_each_entry_safe(p, n, &iucv->message_q.list, list) {
skb = alloc_skb(p->msg.length, GFP_ATOMIC | GFP_DMA);
if (!skb)
break;
iucv_process_message(sk, skb, p->path, &p->msg);
list_del(&p->list);
kfree(p);
if (!skb_queue_empty(&iucv->backlog_skb_q))
break;
}
}
static int iucv_sock_recvmsg(struct kiocb *iocb, struct socket *sock,
struct msghdr *msg, size_t len, int flags)
{
int noblock = flags & MSG_DONTWAIT;
struct sock *sk = sock->sk;
struct iucv_sock *iucv = iucv_sk(sk);
int target, copied = 0;
struct sk_buff *skb, *rskb, *cskb;
int err = 0;
if ((sk->sk_state == IUCV_DISCONN || sk->sk_state == IUCV_SEVERED) &&
skb_queue_empty(&iucv->backlog_skb_q) &&
skb_queue_empty(&sk->sk_receive_queue) &&
list_empty(&iucv->message_q.list))
return 0;
if (flags & (MSG_OOB))
return -EOPNOTSUPP;
target = sock_rcvlowat(sk, flags & MSG_WAITALL, len);
/* receive/dequeue next skb:
* the function understands MSG_PEEK and, thus, does not dequeue skb */
skb = skb_recv_datagram(sk, flags, noblock, &err);
if (!skb) {
if (sk->sk_shutdown & RCV_SHUTDOWN)
return 0;
return err;
}
copied = min_t(unsigned int, skb->len, len);
cskb = skb;
if (memcpy_toiovec(msg->msg_iov, cskb->data, copied)) {
skb_queue_head(&sk->sk_receive_queue, skb);
if (copied == 0)
return -EFAULT;
goto done;
}
len -= copied;
/* Mark read part of skb as used */
if (!(flags & MSG_PEEK)) {
skb_pull(skb, copied);
if (skb->len) {
skb_queue_head(&sk->sk_receive_queue, skb);
goto done;
}
kfree_skb(skb);
/* Queue backlog skbs */
rskb = skb_dequeue(&iucv->backlog_skb_q);
while (rskb) {
if (sock_queue_rcv_skb(sk, rskb)) {
skb_queue_head(&iucv->backlog_skb_q,
rskb);
break;
} else {
rskb = skb_dequeue(&iucv->backlog_skb_q);
}
}
if (skb_queue_empty(&iucv->backlog_skb_q)) {
spin_lock_bh(&iucv->message_q.lock);
if (!list_empty(&iucv->message_q.list))
iucv_process_message_q(sk);
spin_unlock_bh(&iucv->message_q.lock);
}
}
done:
return err ? : copied;
}
static inline unsigned int iucv_accept_poll(struct sock *parent)
{
struct iucv_sock *isk, *n;
struct sock *sk;
list_for_each_entry_safe(isk, n, &iucv_sk(parent)->accept_q, accept_q) {
sk = (struct sock *) isk;
if (sk->sk_state == IUCV_CONNECTED)
return POLLIN | POLLRDNORM;
}
return 0;
}
unsigned int iucv_sock_poll(struct file *file, struct socket *sock,
poll_table *wait)
{
struct sock *sk = sock->sk;
unsigned int mask = 0;
poll_wait(file, sk->sk_sleep, wait);
if (sk->sk_state == IUCV_LISTEN)
return iucv_accept_poll(sk);
if (sk->sk_err || !skb_queue_empty(&sk->sk_error_queue))
mask |= POLLERR;
if (sk->sk_shutdown & RCV_SHUTDOWN)
mask |= POLLRDHUP;
if (sk->sk_shutdown == SHUTDOWN_MASK)
mask |= POLLHUP;
if (!skb_queue_empty(&sk->sk_receive_queue) ||
(sk->sk_shutdown & RCV_SHUTDOWN))
mask |= POLLIN | POLLRDNORM;
if (sk->sk_state == IUCV_CLOSED)
mask |= POLLHUP;
if (sk->sk_state == IUCV_DISCONN || sk->sk_state == IUCV_SEVERED)
mask |= POLLIN;
if (sock_writeable(sk))
mask |= POLLOUT | POLLWRNORM | POLLWRBAND;
else
set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
return mask;
}
static int iucv_sock_shutdown(struct socket *sock, int how)
{
struct sock *sk = sock->sk;
struct iucv_sock *iucv = iucv_sk(sk);
struct iucv_message txmsg;
int err = 0;
u8 prmmsg[8] = {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01};
how++;
if ((how & ~SHUTDOWN_MASK) || !how)
return -EINVAL;
lock_sock(sk);
switch (sk->sk_state) {
case IUCV_DISCONN:
case IUCV_CLOSING:
case IUCV_SEVERED:
case IUCV_CLOSED:
err = -ENOTCONN;
goto fail;
default:
sk->sk_shutdown |= how;
break;
}
if (how == SEND_SHUTDOWN || how == SHUTDOWN_MASK) {
txmsg.class = 0;
txmsg.tag = 0;
err = iucv_message_send(iucv->path, &txmsg, IUCV_IPRMDATA, 0,
(void *) prmmsg, 8);
if (err) {
switch (err) {
case 1:
err = -ENOTCONN;
break;
case 2:
err = -ECONNRESET;
break;
default:
err = -ENOTCONN;
break;
}
}
}
if (how == RCV_SHUTDOWN || how == SHUTDOWN_MASK) {
err = iucv_path_quiesce(iucv_sk(sk)->path, NULL);
if (err)
err = -ENOTCONN;
skb_queue_purge(&sk->sk_receive_queue);
}
/* Wake up anyone sleeping in poll */
sk->sk_state_change(sk);
fail:
release_sock(sk);
return err;
}
static int iucv_sock_release(struct socket *sock)
{
struct sock *sk = sock->sk;
int err = 0;
if (!sk)
return 0;
iucv_sock_close(sk);
/* Unregister with IUCV base support */
if (iucv_sk(sk)->path) {
iucv_path_sever(iucv_sk(sk)->path, NULL);
iucv_path_free(iucv_sk(sk)->path);
iucv_sk(sk)->path = NULL;
}
sock_orphan(sk);
iucv_sock_kill(sk);
return err;
}
/* Callback wrappers - called from iucv base support */
static int iucv_callback_connreq(struct iucv_path *path,
u8 ipvmid[8], u8 ipuser[16])
{
unsigned char user_data[16];
unsigned char nuser_data[16];
unsigned char src_name[8];
struct hlist_node *node;
struct sock *sk, *nsk;
struct iucv_sock *iucv, *niucv;
int err;
memcpy(src_name, ipuser, 8);
EBCASC(src_name, 8);
/* Find out if this path belongs to af_iucv. */
read_lock(&iucv_sk_list.lock);
iucv = NULL;
sk = NULL;
sk_for_each(sk, node, &iucv_sk_list.head)
if (sk->sk_state == IUCV_LISTEN &&
!memcmp(&iucv_sk(sk)->src_name, src_name, 8)) {
/*
* Found a listening socket with
* src_name == ipuser[0-7].
*/
iucv = iucv_sk(sk);
break;
}
read_unlock(&iucv_sk_list.lock);
if (!iucv)
/* No socket found, not one of our paths. */
return -EINVAL;
bh_lock_sock(sk);
/* Check if parent socket is listening */
low_nmcpy(user_data, iucv->src_name);
high_nmcpy(user_data, iucv->dst_name);
ASCEBC(user_data, sizeof(user_data));
if (sk->sk_state != IUCV_LISTEN) {
err = iucv_path_sever(path, user_data);
iucv_path_free(path);
goto fail;
}
/* Check for backlog size */
if (sk_acceptq_is_full(sk)) {
err = iucv_path_sever(path, user_data);
iucv_path_free(path);
goto fail;
}
/* Create the new socket */
nsk = iucv_sock_alloc(NULL, SOCK_STREAM, GFP_ATOMIC);
if (!nsk) {
err = iucv_path_sever(path, user_data);
iucv_path_free(path);
goto fail;
}
niucv = iucv_sk(nsk);
iucv_sock_init(nsk, sk);
/* Set the new iucv_sock */
memcpy(niucv->dst_name, ipuser + 8, 8);
EBCASC(niucv->dst_name, 8);
memcpy(niucv->dst_user_id, ipvmid, 8);
memcpy(niucv->src_name, iucv->src_name, 8);
memcpy(niucv->src_user_id, iucv->src_user_id, 8);
niucv->path = path;
/* Call iucv_accept */
high_nmcpy(nuser_data, ipuser + 8);
memcpy(nuser_data + 8, niucv->src_name, 8);
ASCEBC(nuser_data + 8, 8);
path->msglim = IUCV_QUEUELEN_DEFAULT;
err = iucv_path_accept(path, &af_iucv_handler, nuser_data, nsk);
if (err) {
err = iucv_path_sever(path, user_data);
iucv_path_free(path);
iucv_sock_kill(nsk);
goto fail;
}
iucv_accept_enqueue(sk, nsk);
/* Wake up accept */
nsk->sk_state = IUCV_CONNECTED;
sk->sk_data_ready(sk, 1);
err = 0;
fail:
bh_unlock_sock(sk);
return 0;
}
static void iucv_callback_connack(struct iucv_path *path, u8 ipuser[16])
{
struct sock *sk = path->private;
sk->sk_state = IUCV_CONNECTED;
sk->sk_state_change(sk);
}
static void iucv_callback_rx(struct iucv_path *path, struct iucv_message *msg)
{
struct sock *sk = path->private;
struct iucv_sock *iucv = iucv_sk(sk);
struct sk_buff *skb;
struct sock_msg_q *save_msg;
int len;
if (sk->sk_shutdown & RCV_SHUTDOWN) {
iucv_message_reject(path, msg);
return;
}
spin_lock(&iucv->message_q.lock);
if (!list_empty(&iucv->message_q.list) ||
!skb_queue_empty(&iucv->backlog_skb_q))
goto save_message;
len = atomic_read(&sk->sk_rmem_alloc);
len += msg->length + sizeof(struct sk_buff);
if (len > sk->sk_rcvbuf)
goto save_message;
skb = alloc_skb(msg->length, GFP_ATOMIC | GFP_DMA);
if (!skb)
goto save_message;
iucv_process_message(sk, skb, path, msg);
goto out_unlock;
return;
save_message:
save_msg = kzalloc(sizeof(struct sock_msg_q), GFP_ATOMIC | GFP_DMA);
if (!save_msg)
return;
save_msg->path = path;
save_msg->msg = *msg;
list_add_tail(&save_msg->list, &iucv->message_q.list);
out_unlock:
spin_unlock(&iucv->message_q.lock);
}
static void iucv_callback_txdone(struct iucv_path *path,
struct iucv_message *msg)
{
struct sock *sk = path->private;
struct sk_buff *this = NULL;
struct sk_buff_head *list = &iucv_sk(sk)->send_skb_q;
struct sk_buff *list_skb = list->next;
unsigned long flags;
if (!skb_queue_empty(list)) {
spin_lock_irqsave(&list->lock, flags);
while (list_skb != (struct sk_buff *)list) {
if (!memcmp(&msg->tag, list_skb->cb, 4)) {
this = list_skb;
break;
}
list_skb = list_skb->next;
}
if (this)
__skb_unlink(this, list);
spin_unlock_irqrestore(&list->lock, flags);
kfree_skb(this);
}
BUG_ON(!this);
if (sk->sk_state == IUCV_CLOSING) {
if (skb_queue_empty(&iucv_sk(sk)->send_skb_q)) {
sk->sk_state = IUCV_CLOSED;
sk->sk_state_change(sk);
}
}
}
static void iucv_callback_connrej(struct iucv_path *path, u8 ipuser[16])
{
struct sock *sk = path->private;
if (!list_empty(&iucv_sk(sk)->accept_q))
sk->sk_state = IUCV_SEVERED;
else
sk->sk_state = IUCV_DISCONN;
sk->sk_state_change(sk);
}
static struct proto_ops iucv_sock_ops = {
.family = PF_IUCV,
.owner = THIS_MODULE,
.release = iucv_sock_release,
.bind = iucv_sock_bind,
.connect = iucv_sock_connect,
.listen = iucv_sock_listen,
.accept = iucv_sock_accept,
.getname = iucv_sock_getname,
.sendmsg = iucv_sock_sendmsg,
.recvmsg = iucv_sock_recvmsg,
.poll = iucv_sock_poll,
.ioctl = sock_no_ioctl,
.mmap = sock_no_mmap,
.socketpair = sock_no_socketpair,
.shutdown = iucv_sock_shutdown,
.setsockopt = sock_no_setsockopt,
.getsockopt = sock_no_getsockopt
};
static struct net_proto_family iucv_sock_family_ops = {
.family = AF_IUCV,
.owner = THIS_MODULE,
.create = iucv_sock_create,
};
static int __init afiucv_init(void)
{
int err;
if (!MACHINE_IS_VM) {
pr_err("The af_iucv module cannot be loaded"
" without z/VM\n");
err = -EPROTONOSUPPORT;
goto out;
}
cpcmd("QUERY USERID", iucv_userid, sizeof(iucv_userid), &err);
if (unlikely(err)) {
WARN_ON(err);
err = -EPROTONOSUPPORT;
goto out;
}
err = iucv_register(&af_iucv_handler, 0);
if (err)
goto out;
err = proto_register(&iucv_proto, 0);
if (err)
goto out_iucv;
err = sock_register(&iucv_sock_family_ops);
if (err)
goto out_proto;
return 0;
out_proto:
proto_unregister(&iucv_proto);
out_iucv:
iucv_unregister(&af_iucv_handler, 0);
out:
return err;
}
static void __exit afiucv_exit(void)
{
sock_unregister(PF_IUCV);
proto_unregister(&iucv_proto);
iucv_unregister(&af_iucv_handler, 0);
}
module_init(afiucv_init);
module_exit(afiucv_exit);
MODULE_AUTHOR("Jennifer Hunt <jenhunt@us.ibm.com>");
MODULE_DESCRIPTION("IUCV Sockets ver " VERSION);
MODULE_VERSION(VERSION);
MODULE_LICENSE("GPL");
MODULE_ALIAS_NETPROTO(PF_IUCV);