[S390]: Add AF_IUCV socket support

From: Jennifer Hunt <jenhunt@us.ibm.com>

This patch adds AF_IUCV socket support.

Signed-off-by: Frank Pavlic <fpavlic@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 1077 insertions, 0 deletions

diff --git a/net/iucv/af_iucv.c b/net/iucv/af_iucv.c
new file mode 100644
index 000000000000..acc94214bde6
--- /dev/null
+++ b/net/iucv/af_iucv.c
@@ -0,0 +1,1077 @@
+/*
+ *  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>
+ */
+
+#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),
+};
+
+/* 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,
+        .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 void iucv_sock_init_timer(struct sock *sk)
+{
+        init_timer(&sk->sk_timer);
+        sk->sk_timer.function = iucv_sock_timeout;
+        sk->sk_timer.data = (unsigned long)sk;
+}
+
+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;
+
+        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;
+                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_state = IUCV_CLOSED;
+                sk->sk_state_change(sk);
+                sk->sk_err = ECONNRESET;
+                sk->sk_state_change(sk);
+
+                skb_queue_purge(&iucv->send_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(PF_IUCV, prio, &iucv_proto, 1);
+        if (!sk)
+                return NULL;
+
+        sock_init_data(sock, sk);
+        INIT_LIST_HEAD(&iucv_sk(sk)->accept_q);
+        skb_queue_head_init(&iucv_sk(sk)->send_skb_q);
+        iucv_sk(sk)->send_tag = 0;
+
+        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;
+
+        iucv_sock_init_timer(sk);
+
+        iucv_sock_link(&iucv_sk_list, sk);
+        return sk;
+}
+
+/* Create an IUCV socket */
+static int iucv_sock_create(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)
+{
+        sock_hold(sk);
+        list_add_tail(&iucv_sk(sk)->accept_q, &iucv_sk(parent)->accept_q);
+        iucv_sk(sk)->parent = parent;
+        parent->sk_ack_backlog++;
+}
+
+void iucv_accept_unlink(struct sock *sk)
+{
+        list_del_init(&iucv_sk(sk)->accept_q);
+        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) {
+                        release_sock(sk);
+                        iucv_accept_unlink(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);
+        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;
+                err = -ECONNREFUSED;
+                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;
+        }
+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(sk);
+
+        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(sk);
+
+                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;
+        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)))
+                        return err;
+
+                if (memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len)){
+                        err = -EFAULT;
+                        goto fail;
+                }
+
+                txmsg.class = 0;
+                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)
+                                printk(KERN_ERR "AF_IUCV msg limit exceeded\n");
+                        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_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;
+        int target, copied = 0;
+        struct sk_buff *skb;
+        int err = 0;
+
+        if (flags & (MSG_OOB))
+                return -EOPNOTSUPP;
+
+        target = sock_rcvlowat(sk, flags & MSG_WAITALL, len);
+
+        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);
+
+        if (memcpy_toiovec(msg->msg_iov, skb->data, copied)) {
+                skb_queue_head(&sk->sk_receive_queue, skb);
+                if (copied == 0)
+                        return -EFAULT;
+        }
+
+        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);
+        } else
+                skb_queue_head(&sk->sk_receive_queue, skb);
+
+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 (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_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;
+        }
+
+        if (sock_flag(sk, SOCK_LINGER) && sk->sk_lingertime){
+                lock_sock(sk);
+                err = iucv_sock_wait_state(sk, IUCV_CLOSED, 0,
+                                           sk->sk_lingertime);
+                release_sock(sk);
+        }
+
+        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_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);
+                goto fail;
+        }
+
+        /* Check for backlog size */
+        if (sk_acceptq_is_full(sk)) {
+                err = iucv_path_sever(path, user_data);
+                goto fail;
+        }
+
+        /* Create the new socket */
+        nsk = iucv_sock_alloc(NULL, SOCK_STREAM, GFP_ATOMIC);
+        if (!nsk){
+                err = iucv_path_sever(path, user_data);
+                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);
+                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 sk_buff *skb;
+        int rc;
+
+        if (sk->sk_shutdown & RCV_SHUTDOWN)
+                return;
+
+        skb = alloc_skb(msg->length, GFP_ATOMIC | GFP_DMA);
+        if (!skb) {
+                iucv_message_reject(path, msg);
+                return;
+        }
+
+        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;
+                }
+
+                skb->h.raw = skb->data;
+                skb->nh.raw = skb->data;
+                skb->len = msg->length;
+        }
+
+        if (sock_queue_rcv_skb(sk, skb))
+                kfree_skb(skb);
+}
+
+static void iucv_callback_txdone(struct iucv_path *path,
+                                 struct iucv_message *msg)
+{
+        struct sock *sk = path->private;
+        struct sk_buff *this;
+        struct sk_buff_head *list = &iucv_sk(sk)->send_skb_q;
+        struct sk_buff *list_skb = list->next;
+        unsigned long flags;
+
+        spin_lock_irqsave(&list->lock, flags);
+
+        do {
+                this = list_skb;
+                list_skb = list_skb->next;
+        } while (memcmp(&msg->tag, this->cb, 4));
+
+        spin_unlock_irqrestore(&list->lock, flags);
+
+        skb_unlink(this, &iucv_sk(sk)->send_skb_q);
+        kfree_skb(this);
+}
+
+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 afiucv_init(void)
+{
+        int err;
+
+        if (!MACHINE_IS_VM) {
+                printk(KERN_ERR "AF_IUCV connection needs VM as base\n");
+                err = -EPROTONOSUPPORT;
+                goto out;
+        }
+        cpcmd("QUERY USERID", iucv_userid, sizeof(iucv_userid), &err);
+        if (unlikely(err)) {
+                printk(KERN_ERR "AF_IUCV needs the VM userid\n");
+                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;
+        printk(KERN_INFO "AF_IUCV lowlevel driver initialized\n");
+        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);
+
+        printk(KERN_INFO "AF_IUCV lowlevel driver unloaded\n");
+}
+
+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);