Add the rt linux 4.1.3-rt3 as base
[kvmfornfv.git] / kernel / net / iucv / af_iucv.c
diff --git a/kernel/net/iucv/af_iucv.c b/kernel/net/iucv/af_iucv.c
new file mode 100644 (file)
index 0000000..6daa52a
--- /dev/null
@@ -0,0 +1,2463 @@
+/*
+ *  IUCV protocol stack for Linux on zSeries
+ *
+ *  Copyright IBM Corp. 2006, 2009
+ *
+ *  Author(s): Jennifer Hunt <jenhunt@us.ibm.com>
+ *             Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
+ *  PM functions:
+ *             Ursula Braun <ursula.braun@de.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/af_iucv.h>
+
+#define VERSION "1.2"
+
+static char iucv_userid[80];
+
+static const struct proto_ops iucv_sock_ops;
+
+static struct proto iucv_proto = {
+       .name           = "AF_IUCV",
+       .owner          = THIS_MODULE,
+       .obj_size       = sizeof(struct iucv_sock),
+};
+
+static struct iucv_interface *pr_iucv;
+
+/* special AF_IUCV IPRM messages */
+static const u8 iprm_shutdown[8] =
+       {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01};
+
+#define TRGCLS_SIZE    (sizeof(((struct iucv_message *)0)->class))
+
+#define __iucv_sock_wait(sk, condition, timeo, ret)                    \
+do {                                                                   \
+       DEFINE_WAIT(__wait);                                            \
+       long __timeo = timeo;                                           \
+       ret = 0;                                                        \
+       prepare_to_wait(sk_sleep(sk), &__wait, TASK_INTERRUPTIBLE);     \
+       while (!(condition)) {                                          \
+               if (!__timeo) {                                         \
+                       ret = -EAGAIN;                                  \
+                       break;                                          \
+               }                                                       \
+               if (signal_pending(current)) {                          \
+                       ret = sock_intr_errno(__timeo);                 \
+                       break;                                          \
+               }                                                       \
+               release_sock(sk);                                       \
+               __timeo = schedule_timeout(__timeo);                    \
+               lock_sock(sk);                                          \
+               ret = sock_error(sk);                                   \
+               if (ret)                                                \
+                       break;                                          \
+       }                                                               \
+       finish_wait(sk_sleep(sk), &__wait);                             \
+} while (0)
+
+#define iucv_sock_wait(sk, condition, timeo)                           \
+({                                                                     \
+       int __ret = 0;                                                  \
+       if (!(condition))                                               \
+               __iucv_sock_wait(sk, condition, timeo, __ret);          \
+       __ret;                                                          \
+})
+
+static void iucv_sock_kill(struct sock *sk);
+static void iucv_sock_close(struct sock *sk);
+static void iucv_sever_path(struct sock *, int);
+
+static int afiucv_hs_rcv(struct sk_buff *skb, struct net_device *dev,
+       struct packet_type *pt, struct net_device *orig_dev);
+static int afiucv_hs_send(struct iucv_message *imsg, struct sock *sock,
+                  struct sk_buff *skb, u8 flags);
+static void afiucv_hs_callback_txnotify(struct sk_buff *, enum iucv_tx_notify);
+
+/* 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 void iucv_callback_shutdown(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,
+       .path_quiesced    = iucv_callback_shutdown,
+};
+
+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);
+}
+
+static int afiucv_pm_prepare(struct device *dev)
+{
+#ifdef CONFIG_PM_DEBUG
+       printk(KERN_WARNING "afiucv_pm_prepare\n");
+#endif
+       return 0;
+}
+
+static void afiucv_pm_complete(struct device *dev)
+{
+#ifdef CONFIG_PM_DEBUG
+       printk(KERN_WARNING "afiucv_pm_complete\n");
+#endif
+}
+
+/**
+ * afiucv_pm_freeze() - Freeze PM callback
+ * @dev:       AFIUCV dummy device
+ *
+ * Sever all established IUCV communication pathes
+ */
+static int afiucv_pm_freeze(struct device *dev)
+{
+       struct iucv_sock *iucv;
+       struct sock *sk;
+       int err = 0;
+
+#ifdef CONFIG_PM_DEBUG
+       printk(KERN_WARNING "afiucv_pm_freeze\n");
+#endif
+       read_lock(&iucv_sk_list.lock);
+       sk_for_each(sk, &iucv_sk_list.head) {
+               iucv = iucv_sk(sk);
+               switch (sk->sk_state) {
+               case IUCV_DISCONN:
+               case IUCV_CLOSING:
+               case IUCV_CONNECTED:
+                       iucv_sever_path(sk, 0);
+                       break;
+               case IUCV_OPEN:
+               case IUCV_BOUND:
+               case IUCV_LISTEN:
+               case IUCV_CLOSED:
+               default:
+                       break;
+               }
+               skb_queue_purge(&iucv->send_skb_q);
+               skb_queue_purge(&iucv->backlog_skb_q);
+       }
+       read_unlock(&iucv_sk_list.lock);
+       return err;
+}
+
+/**
+ * afiucv_pm_restore_thaw() - Thaw and restore PM callback
+ * @dev:       AFIUCV dummy device
+ *
+ * socket clean up after freeze
+ */
+static int afiucv_pm_restore_thaw(struct device *dev)
+{
+       struct sock *sk;
+
+#ifdef CONFIG_PM_DEBUG
+       printk(KERN_WARNING "afiucv_pm_restore_thaw\n");
+#endif
+       read_lock(&iucv_sk_list.lock);
+       sk_for_each(sk, &iucv_sk_list.head) {
+               switch (sk->sk_state) {
+               case IUCV_CONNECTED:
+                       sk->sk_err = EPIPE;
+                       sk->sk_state = IUCV_DISCONN;
+                       sk->sk_state_change(sk);
+                       break;
+               case IUCV_DISCONN:
+               case IUCV_CLOSING:
+               case IUCV_LISTEN:
+               case IUCV_BOUND:
+               case IUCV_OPEN:
+               default:
+                       break;
+               }
+       }
+       read_unlock(&iucv_sk_list.lock);
+       return 0;
+}
+
+static const struct dev_pm_ops afiucv_pm_ops = {
+       .prepare = afiucv_pm_prepare,
+       .complete = afiucv_pm_complete,
+       .freeze = afiucv_pm_freeze,
+       .thaw = afiucv_pm_restore_thaw,
+       .restore = afiucv_pm_restore_thaw,
+};
+
+static struct device_driver af_iucv_driver = {
+       .owner = THIS_MODULE,
+       .name = "afiucv",
+       .bus  = NULL,
+       .pm   = &afiucv_pm_ops,
+};
+
+/* dummy device used as trigger for PM functions */
+static struct device *af_iucv_dev;
+
+/**
+ * iucv_msg_length() - Returns the length of an iucv message.
+ * @msg:       Pointer to struct iucv_message, MUST NOT be NULL
+ *
+ * The function returns the length of the specified iucv message @msg of data
+ * stored in a buffer and of data stored in the parameter list (PRMDATA).
+ *
+ * For IUCV_IPRMDATA, AF_IUCV uses the following convention to transport socket
+ * data:
+ *     PRMDATA[0..6]   socket data (max 7 bytes);
+ *     PRMDATA[7]      socket data length value (len is 0xff - PRMDATA[7])
+ *
+ * The socket data length is computed by subtracting the socket data length
+ * value from 0xFF.
+ * If the socket data len is greater 7, then PRMDATA can be used for special
+ * notifications (see iucv_sock_shutdown); and further,
+ * if the socket data len is > 7, the function returns 8.
+ *
+ * Use this function to allocate socket buffers to store iucv message data.
+ */
+static inline size_t iucv_msg_length(struct iucv_message *msg)
+{
+       size_t datalen;
+
+       if (msg->flags & IUCV_IPRMDATA) {
+               datalen = 0xff - msg->rmmsg[7];
+               return (datalen < 8) ? datalen : 8;
+       }
+       return msg->length;
+}
+
+/**
+ * iucv_sock_in_state() - check for specific states
+ * @sk:                sock structure
+ * @state:     first iucv sk state
+ * @state:     second iucv sk state
+ *
+ * Returns true if the socket in either in the first or second state.
+ */
+static int iucv_sock_in_state(struct sock *sk, int state, int state2)
+{
+       return (sk->sk_state == state || sk->sk_state == state2);
+}
+
+/**
+ * iucv_below_msglim() - function to check if messages can be sent
+ * @sk:                sock structure
+ *
+ * Returns true if the send queue length is lower than the message limit.
+ * Always returns true if the socket is not connected (no iucv path for
+ * checking the message limit).
+ */
+static inline int iucv_below_msglim(struct sock *sk)
+{
+       struct iucv_sock *iucv = iucv_sk(sk);
+
+       if (sk->sk_state != IUCV_CONNECTED)
+               return 1;
+       if (iucv->transport == AF_IUCV_TRANS_IUCV)
+               return (skb_queue_len(&iucv->send_skb_q) < iucv->path->msglim);
+       else
+               return ((atomic_read(&iucv->msg_sent) < iucv->msglimit_peer) &&
+                       (atomic_read(&iucv->pendings) <= 0));
+}
+
+/**
+ * iucv_sock_wake_msglim() - Wake up thread waiting on msg limit
+ */
+static void iucv_sock_wake_msglim(struct sock *sk)
+{
+       struct socket_wq *wq;
+
+       rcu_read_lock();
+       wq = rcu_dereference(sk->sk_wq);
+       if (wq_has_sleeper(wq))
+               wake_up_interruptible_all(&wq->wait);
+       sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
+       rcu_read_unlock();
+}
+
+/**
+ * afiucv_hs_send() - send a message through HiperSockets transport
+ */
+static int afiucv_hs_send(struct iucv_message *imsg, struct sock *sock,
+                  struct sk_buff *skb, u8 flags)
+{
+       struct iucv_sock *iucv = iucv_sk(sock);
+       struct af_iucv_trans_hdr *phs_hdr;
+       struct sk_buff *nskb;
+       int err, confirm_recv = 0;
+
+       memset(skb->head, 0, ETH_HLEN);
+       phs_hdr = (struct af_iucv_trans_hdr *)skb_push(skb,
+                                       sizeof(struct af_iucv_trans_hdr));
+       skb_reset_mac_header(skb);
+       skb_reset_network_header(skb);
+       skb_push(skb, ETH_HLEN);
+       skb_reset_mac_header(skb);
+       memset(phs_hdr, 0, sizeof(struct af_iucv_trans_hdr));
+
+       phs_hdr->magic = ETH_P_AF_IUCV;
+       phs_hdr->version = 1;
+       phs_hdr->flags = flags;
+       if (flags == AF_IUCV_FLAG_SYN)
+               phs_hdr->window = iucv->msglimit;
+       else if ((flags == AF_IUCV_FLAG_WIN) || !flags) {
+               confirm_recv = atomic_read(&iucv->msg_recv);
+               phs_hdr->window = confirm_recv;
+               if (confirm_recv)
+                       phs_hdr->flags = phs_hdr->flags | AF_IUCV_FLAG_WIN;
+       }
+       memcpy(phs_hdr->destUserID, iucv->dst_user_id, 8);
+       memcpy(phs_hdr->destAppName, iucv->dst_name, 8);
+       memcpy(phs_hdr->srcUserID, iucv->src_user_id, 8);
+       memcpy(phs_hdr->srcAppName, iucv->src_name, 8);
+       ASCEBC(phs_hdr->destUserID, sizeof(phs_hdr->destUserID));
+       ASCEBC(phs_hdr->destAppName, sizeof(phs_hdr->destAppName));
+       ASCEBC(phs_hdr->srcUserID, sizeof(phs_hdr->srcUserID));
+       ASCEBC(phs_hdr->srcAppName, sizeof(phs_hdr->srcAppName));
+       if (imsg)
+               memcpy(&phs_hdr->iucv_hdr, imsg, sizeof(struct iucv_message));
+
+       skb->dev = iucv->hs_dev;
+       if (!skb->dev)
+               return -ENODEV;
+       if (!(skb->dev->flags & IFF_UP) || !netif_carrier_ok(skb->dev))
+               return -ENETDOWN;
+       if (skb->len > skb->dev->mtu) {
+               if (sock->sk_type == SOCK_SEQPACKET)
+                       return -EMSGSIZE;
+               else
+                       skb_trim(skb, skb->dev->mtu);
+       }
+       skb->protocol = ETH_P_AF_IUCV;
+       nskb = skb_clone(skb, GFP_ATOMIC);
+       if (!nskb)
+               return -ENOMEM;
+       skb_queue_tail(&iucv->send_skb_q, nskb);
+       err = dev_queue_xmit(skb);
+       if (net_xmit_eval(err)) {
+               skb_unlink(nskb, &iucv->send_skb_q);
+               kfree_skb(nskb);
+       } else {
+               atomic_sub(confirm_recv, &iucv->msg_recv);
+               WARN_ON(atomic_read(&iucv->msg_recv) < 0);
+       }
+       return net_xmit_eval(err);
+}
+
+static struct sock *__iucv_get_sock_by_name(char *nm)
+{
+       struct sock *sk;
+
+       sk_for_each(sk, &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_error_queue);
+
+       sk_mem_reclaim(sk);
+
+       if (!sock_flag(sk, SOCK_DEAD)) {
+               pr_err("Attempt to release alive iucv socket %p\n", sk);
+               return;
+       }
+
+       WARN_ON(atomic_read(&sk->sk_rmem_alloc));
+       WARN_ON(atomic_read(&sk->sk_wmem_alloc));
+       WARN_ON(sk->sk_wmem_queued);
+       WARN_ON(sk->sk_forward_alloc);
+}
+
+/* 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;
+}
+
+/* Kill socket (only if zapped and orphaned) */
+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);
+}
+
+/* Terminate an IUCV path */
+static void iucv_sever_path(struct sock *sk, int with_user_data)
+{
+       unsigned char user_data[16];
+       struct iucv_sock *iucv = iucv_sk(sk);
+       struct iucv_path *path = iucv->path;
+
+       if (iucv->path) {
+               iucv->path = NULL;
+               if (with_user_data) {
+                       low_nmcpy(user_data, iucv->src_name);
+                       high_nmcpy(user_data, iucv->dst_name);
+                       ASCEBC(user_data, sizeof(user_data));
+                       pr_iucv->path_sever(path, user_data);
+               } else
+                       pr_iucv->path_sever(path, NULL);
+               iucv_path_free(path);
+       }
+}
+
+/* Send FIN through an IUCV socket for HIPER transport */
+static int iucv_send_ctrl(struct sock *sk, u8 flags)
+{
+       int err = 0;
+       int blen;
+       struct sk_buff *skb;
+
+       blen = sizeof(struct af_iucv_trans_hdr) + ETH_HLEN;
+       skb = sock_alloc_send_skb(sk, blen, 1, &err);
+       if (skb) {
+               skb_reserve(skb, blen);
+               err = afiucv_hs_send(NULL, sk, skb, flags);
+       }
+       return err;
+}
+
+/* Close an IUCV socket */
+static void iucv_sock_close(struct sock *sk)
+{
+       struct iucv_sock *iucv = iucv_sk(sk);
+       unsigned long timeo;
+       int err = 0;
+
+       lock_sock(sk);
+
+       switch (sk->sk_state) {
+       case IUCV_LISTEN:
+               iucv_sock_cleanup_listen(sk);
+               break;
+
+       case IUCV_CONNECTED:
+               if (iucv->transport == AF_IUCV_TRANS_HIPER) {
+                       err = iucv_send_ctrl(sk, AF_IUCV_FLAG_FIN);
+                       sk->sk_state = IUCV_DISCONN;
+                       sk->sk_state_change(sk);
+               }
+       case IUCV_DISCONN:   /* fall through */
+               sk->sk_state = IUCV_CLOSING;
+               sk->sk_state_change(sk);
+
+               if (!err && !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;
+                       iucv_sock_wait(sk,
+                                       iucv_sock_in_state(sk, IUCV_CLOSED, 0),
+                                       timeo);
+               }
+
+       case IUCV_CLOSING:   /* fall through */
+               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);
+               skb_queue_purge(&iucv->backlog_skb_q);
+
+       default:   /* fall through */
+               iucv_sever_path(sk, 1);
+       }
+
+       if (iucv->hs_dev) {
+               dev_put(iucv->hs_dev);
+               iucv->hs_dev = NULL;
+               sk->sk_bound_dev_if = 0;
+       }
+
+       /* mark socket for deletion by iucv_sock_kill() */
+       sock_set_flag(sk, SOCK_ZAPPED);
+
+       release_sock(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;
+       struct iucv_sock *iucv;
+
+       sk = sk_alloc(&init_net, PF_IUCV, prio, &iucv_proto);
+       if (!sk)
+               return NULL;
+       iucv = iucv_sk(sk);
+
+       sock_init_data(sock, sk);
+       INIT_LIST_HEAD(&iucv->accept_q);
+       spin_lock_init(&iucv->accept_q_lock);
+       skb_queue_head_init(&iucv->send_skb_q);
+       INIT_LIST_HEAD(&iucv->message_q.list);
+       spin_lock_init(&iucv->message_q.lock);
+       skb_queue_head_init(&iucv->backlog_skb_q);
+       iucv->send_tag = 0;
+       atomic_set(&iucv->pendings, 0);
+       iucv->flags = 0;
+       iucv->msglimit = 0;
+       atomic_set(&iucv->msg_sent, 0);
+       atomic_set(&iucv->msg_recv, 0);
+       iucv->path = NULL;
+       iucv->sk_txnotify = afiucv_hs_callback_txnotify;
+       memset(&iucv->src_user_id , 0, 32);
+       if (pr_iucv)
+               iucv->transport = AF_IUCV_TRANS_IUCV;
+       else
+               iucv->transport = AF_IUCV_TRANS_HIPER;
+
+       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_link(&iucv_sk_list, sk);
+       return sk;
+}
+
+/* Create an IUCV socket */
+static int iucv_sock_create(struct net *net, struct socket *sock, int protocol,
+                           int kern)
+{
+       struct sock *sk;
+
+       if (protocol && protocol != PF_IUCV)
+               return -EPROTONOSUPPORT;
+
+       sock->state = SS_UNCONNECTED;
+
+       switch (sock->type) {
+       case SOCK_STREAM:
+               sock->ops = &iucv_sock_ops;
+               break;
+       case SOCK_SEQPACKET:
+               /* currently, proto ops can handle both sk types */
+               sock->ops = &iucv_sock_ops;
+               break;
+       default:
+               return -ESOCKTNOSUPPORT;
+       }
+
+       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;
+       sk_acceptq_added(parent);
+}
+
+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);
+       sk_acceptq_removed(iucv_sk(sk)->parent);
+       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_DISCONN ||
+                   !newsock) {
+                       iucv_accept_unlink(sk);
+                       if (newsock)
+                               sock_graft(sk, newsock);
+
+                       release_sock(sk);
+                       return sk;
+               }
+
+               release_sock(sk);
+       }
+       return NULL;
+}
+
+static void __iucv_auto_name(struct iucv_sock *iucv)
+{
+       char name[12];
+
+       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));
+       }
+       memcpy(iucv->src_name, name, 8);
+}
+
+/* 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 = 0;
+       struct net_device *dev;
+       char uid[9];
+
+       /* 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)
+               goto done_unlock;
+
+       /* Bind the socket */
+       if (pr_iucv)
+               if (!memcmp(sa->siucv_user_id, iucv_userid, 8))
+                       goto vm_bind; /* VM IUCV transport */
+
+       /* try hiper transport */
+       memcpy(uid, sa->siucv_user_id, sizeof(uid));
+       ASCEBC(uid, 8);
+       rcu_read_lock();
+       for_each_netdev_rcu(&init_net, dev) {
+               if (!memcmp(dev->perm_addr, uid, 8)) {
+                       memcpy(iucv->src_user_id, sa->siucv_user_id, 8);
+                       /* Check for unitialized siucv_name */
+                       if (strncmp(sa->siucv_name, "        ", 8) == 0)
+                               __iucv_auto_name(iucv);
+                       else
+                               memcpy(iucv->src_name, sa->siucv_name, 8);
+                       sk->sk_bound_dev_if = dev->ifindex;
+                       iucv->hs_dev = dev;
+                       dev_hold(dev);
+                       sk->sk_state = IUCV_BOUND;
+                       iucv->transport = AF_IUCV_TRANS_HIPER;
+                       if (!iucv->msglimit)
+                               iucv->msglimit = IUCV_HIPER_MSGLIM_DEFAULT;
+                       rcu_read_unlock();
+                       goto done_unlock;
+               }
+       }
+       rcu_read_unlock();
+vm_bind:
+       if (pr_iucv) {
+               /* use local userid for backward compat */
+               memcpy(iucv->src_name, sa->siucv_name, 8);
+               memcpy(iucv->src_user_id, iucv_userid, 8);
+               sk->sk_state = IUCV_BOUND;
+               iucv->transport = AF_IUCV_TRANS_IUCV;
+               if (!iucv->msglimit)
+                       iucv->msglimit = IUCV_QUEUELEN_DEFAULT;
+               goto done_unlock;
+       }
+       /* found no dev to bind */
+       err = -ENODEV;
+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);
+       int err = 0;
+
+       if (unlikely(!pr_iucv))
+               return -EPROTO;
+
+       memcpy(iucv->src_user_id, iucv_userid, 8);
+
+       write_lock_bh(&iucv_sk_list.lock);
+       __iucv_auto_name(iucv);
+       write_unlock_bh(&iucv_sk_list.lock);
+
+       if (!iucv->msglimit)
+               iucv->msglimit = IUCV_QUEUELEN_DEFAULT;
+
+       return err;
+}
+
+static int afiucv_path_connect(struct socket *sock, struct sockaddr *addr)
+{
+       struct sockaddr_iucv *sa = (struct sockaddr_iucv *) addr;
+       struct sock *sk = sock->sk;
+       struct iucv_sock *iucv = iucv_sk(sk);
+       unsigned char user_data[16];
+       int err;
+
+       high_nmcpy(user_data, sa->siucv_name);
+       low_nmcpy(user_data, iucv->src_name);
+       ASCEBC(user_data, sizeof(user_data));
+
+       /* Create path. */
+       iucv->path = iucv_path_alloc(iucv->msglimit,
+                                    IUCV_IPRMDATA, GFP_KERNEL);
+       if (!iucv->path) {
+               err = -ENOMEM;
+               goto done;
+       }
+       err = pr_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;
+               }
+       }
+done:
+       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 = iucv_sk(sk);
+       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_state == IUCV_OPEN &&
+           iucv->transport == AF_IUCV_TRANS_HIPER)
+               return -EBADFD; /* explicit bind required */
+
+       if (sk->sk_type != SOCK_STREAM && sk->sk_type != SOCK_SEQPACKET)
+               return -EINVAL;
+
+       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->dst_user_id, sa->siucv_user_id, 8);
+       memcpy(iucv->dst_name, sa->siucv_name, 8);
+
+       if (iucv->transport == AF_IUCV_TRANS_HIPER)
+               err = iucv_send_ctrl(sock->sk, AF_IUCV_FLAG_SYN);
+       else
+               err = afiucv_path_connect(sock, addr);
+       if (err)
+               goto done;
+
+       if (sk->sk_state != IUCV_CONNECTED)
+               err = iucv_sock_wait(sk, iucv_sock_in_state(sk, IUCV_CONNECTED,
+                                                           IUCV_DISCONN),
+                                    sock_sndtimeo(sk, flags & O_NONBLOCK));
+
+       if (sk->sk_state == IUCV_DISCONN || sk->sk_state == IUCV_CLOSED)
+               err = -ECONNREFUSED;
+
+       if (err && iucv->transport == AF_IUCV_TRANS_IUCV)
+               iucv_sever_path(sk, 0);
+
+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)
+               goto done;
+
+       if (sock->type != SOCK_STREAM && sock->type != SOCK_SEQPACKET)
+               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_sleep(sk), &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_sleep(sk), &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;
+       struct iucv_sock *iucv = iucv_sk(sk);
+
+       addr->sa_family = AF_IUCV;
+       *len = sizeof(struct sockaddr_iucv);
+
+       if (peer) {
+               memcpy(siucv->siucv_user_id, iucv->dst_user_id, 8);
+               memcpy(siucv->siucv_name, iucv->dst_name, 8);
+       } else {
+               memcpy(siucv->siucv_user_id, iucv->src_user_id, 8);
+               memcpy(siucv->siucv_name, iucv->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;
+}
+
+/**
+ * iucv_send_iprm() - Send socket data in parameter list of an iucv message.
+ * @path:      IUCV path
+ * @msg:       Pointer to a struct iucv_message
+ * @skb:       The socket data to send, skb->len MUST BE <= 7
+ *
+ * Send the socket data in the parameter list in the iucv message
+ * (IUCV_IPRMDATA). The socket data is stored at index 0 to 6 in the parameter
+ * list and the socket data len at index 7 (last byte).
+ * See also iucv_msg_length().
+ *
+ * Returns the error code from the iucv_message_send() call.
+ */
+static int iucv_send_iprm(struct iucv_path *path, struct iucv_message *msg,
+                         struct sk_buff *skb)
+{
+       u8 prmdata[8];
+
+       memcpy(prmdata, (void *) skb->data, skb->len);
+       prmdata[7] = 0xff - (u8) skb->len;
+       return pr_iucv->message_send(path, msg, IUCV_IPRMDATA, 0,
+                                (void *) prmdata, 8);
+}
+
+static int iucv_sock_sendmsg(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;
+       struct cmsghdr *cmsg;
+       int cmsg_done;
+       long timeo;
+       char user_id[9];
+       char appl_id[9];
+       int err;
+       int noblock = msg->msg_flags & MSG_DONTWAIT;
+
+       err = sock_error(sk);
+       if (err)
+               return err;
+
+       if (msg->msg_flags & MSG_OOB)
+               return -EOPNOTSUPP;
+
+       /* SOCK_SEQPACKET: we do not support segmented records */
+       if (sk->sk_type == SOCK_SEQPACKET && !(msg->msg_flags & MSG_EOR))
+               return -EOPNOTSUPP;
+
+       lock_sock(sk);
+
+       if (sk->sk_shutdown & SEND_SHUTDOWN) {
+               err = -EPIPE;
+               goto out;
+       }
+
+       /* Return if the socket is not in connected state */
+       if (sk->sk_state != IUCV_CONNECTED) {
+               err = -ENOTCONN;
+               goto out;
+       }
+
+       /* initialize defaults */
+       cmsg_done   = 0;        /* check for duplicate headers */
+       txmsg.class = 0;
+
+       /* iterate over control messages */
+       for_each_cmsghdr(cmsg, msg) {
+               if (!CMSG_OK(msg, cmsg)) {
+                       err = -EINVAL;
+                       goto out;
+               }
+
+               if (cmsg->cmsg_level != SOL_IUCV)
+                       continue;
+
+               if (cmsg->cmsg_type & cmsg_done) {
+                       err = -EINVAL;
+                       goto out;
+               }
+               cmsg_done |= cmsg->cmsg_type;
+
+               switch (cmsg->cmsg_type) {
+               case SCM_IUCV_TRGCLS:
+                       if (cmsg->cmsg_len != CMSG_LEN(TRGCLS_SIZE)) {
+                               err = -EINVAL;
+                               goto out;
+                       }
+
+                       /* set iucv message target class */
+                       memcpy(&txmsg.class,
+                               (void *) CMSG_DATA(cmsg), TRGCLS_SIZE);
+
+                       break;
+
+               default:
+                       err = -EINVAL;
+                       goto out;
+               }
+       }
+
+       /* allocate one skb for each iucv message:
+        * this is fine for SOCK_SEQPACKET (unless we want to support
+        * segmented records using the MSG_EOR flag), but
+        * for SOCK_STREAM we might want to improve it in future */
+       if (iucv->transport == AF_IUCV_TRANS_HIPER)
+               skb = sock_alloc_send_skb(sk,
+                       len + sizeof(struct af_iucv_trans_hdr) + ETH_HLEN,
+                       noblock, &err);
+       else
+               skb = sock_alloc_send_skb(sk, len, noblock, &err);
+       if (!skb)
+               goto out;
+       if (iucv->transport == AF_IUCV_TRANS_HIPER)
+               skb_reserve(skb, sizeof(struct af_iucv_trans_hdr) + ETH_HLEN);
+       if (memcpy_from_msg(skb_put(skb, len), msg, len)) {
+               err = -EFAULT;
+               goto fail;
+       }
+
+       /* wait if outstanding messages for iucv path has reached */
+       timeo = sock_sndtimeo(sk, noblock);
+       err = iucv_sock_wait(sk, iucv_below_msglim(sk), timeo);
+       if (err)
+               goto fail;
+
+       /* return -ECONNRESET if the socket is no longer connected */
+       if (sk->sk_state != IUCV_CONNECTED) {
+               err = -ECONNRESET;
+               goto fail;
+       }
+
+       /* increment and save iucv message tag for msg_completion cbk */
+       txmsg.tag = iucv->send_tag++;
+       IUCV_SKB_CB(skb)->tag = txmsg.tag;
+
+       if (iucv->transport == AF_IUCV_TRANS_HIPER) {
+               atomic_inc(&iucv->msg_sent);
+               err = afiucv_hs_send(&txmsg, sk, skb, 0);
+               if (err) {
+                       atomic_dec(&iucv->msg_sent);
+                       goto fail;
+               }
+               goto release;
+       }
+       skb_queue_tail(&iucv->send_skb_q, skb);
+
+       if (((iucv->path->flags & IUCV_IPRMDATA) & iucv->flags)
+             && skb->len <= 7) {
+               err = iucv_send_iprm(iucv->path, &txmsg, skb);
+
+               /* on success: there is no message_complete callback
+                * for an IPRMDATA msg; remove skb from send queue */
+               if (err == 0) {
+                       skb_unlink(skb, &iucv->send_skb_q);
+                       kfree_skb(skb);
+               }
+
+               /* this error should never happen since the
+                * IUCV_IPRMDATA path flag is set... sever path */
+               if (err == 0x15) {
+                       pr_iucv->path_sever(iucv->path, NULL);
+                       skb_unlink(skb, &iucv->send_skb_q);
+                       err = -EPIPE;
+                       goto fail;
+               }
+       } else
+               err = pr_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",
+                               appl_id, user_id);
+                       err = -EAGAIN;
+               } else
+                       err = -EPIPE;
+               skb_unlink(skb, &iucv->send_skb_q);
+               goto fail;
+       }
+
+release:
+       release_sock(sk);
+       return len;
+
+fail:
+       kfree_skb(skb);
+out:
+       release_sock(sk);
+       return err;
+}
+
+/* iucv_fragment_skb() - Fragment a single IUCV message into multiple skb's
+ *
+ * Locking: must be called with message_q.lock held
+ */
+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;
+
+               /* copy target class to control buffer of new skb */
+               IUCV_SKB_CB(nskb)->class = IUCV_SKB_CB(skb)->class;
+
+               /* copy data fragment */
+               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;
+}
+
+/* iucv_process_message() - Receive a single outstanding IUCV message
+ *
+ * Locking: must be called with message_q.lock held
+ */
+static void iucv_process_message(struct sock *sk, struct sk_buff *skb,
+                                struct iucv_path *path,
+                                struct iucv_message *msg)
+{
+       int rc;
+       unsigned int len;
+
+       len = iucv_msg_length(msg);
+
+       /* store msg target class in the second 4 bytes of skb ctrl buffer */
+       /* Note: the first 4 bytes are reserved for msg tag */
+       IUCV_SKB_CB(skb)->class = msg->class;
+
+       /* check for special IPRM messages (e.g. iucv_sock_shutdown) */
+       if ((msg->flags & IUCV_IPRMDATA) && len > 7) {
+               if (memcmp(msg->rmmsg, iprm_shutdown, 8) == 0) {
+                       skb->data = NULL;
+                       skb->len = 0;
+               }
+       } else {
+               rc = pr_iucv->message_receive(path, msg,
+                                             msg->flags & IUCV_IPRMDATA,
+                                             skb->data, len, NULL);
+               if (rc) {
+                       kfree_skb(skb);
+                       return;
+               }
+               /* we need to fragment iucv messages for SOCK_STREAM only;
+                * for SOCK_SEQPACKET, it is only relevant if we support
+                * record segmentation using MSG_EOR (see also recvmsg()) */
+               if (sk->sk_type == SOCK_STREAM &&
+                   skb->truesize >= sk->sk_rcvbuf / 4) {
+                       rc = iucv_fragment_skb(sk, skb, len);
+                       kfree_skb(skb);
+                       skb = NULL;
+                       if (rc) {
+                               pr_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 = len;
+               }
+       }
+
+       IUCV_SKB_CB(skb)->offset = 0;
+       if (sock_queue_rcv_skb(sk, skb))
+               skb_queue_head(&iucv_sk(sk)->backlog_skb_q, skb);
+}
+
+/* iucv_process_message_q() - Process outstanding IUCV messages
+ *
+ * Locking: must be called with message_q.lock held
+ */
+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(iucv_msg_length(&p->msg), 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 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);
+       unsigned int copied, rlen;
+       struct sk_buff *skb, *rskb, *cskb;
+       int err = 0;
+       u32 offset;
+
+       if ((sk->sk_state == IUCV_DISCONN) &&
+           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;
+
+       /* 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;
+       }
+
+       offset = IUCV_SKB_CB(skb)->offset;
+       rlen   = skb->len - offset;             /* real length of skb */
+       copied = min_t(unsigned int, rlen, len);
+       if (!rlen)
+               sk->sk_shutdown = sk->sk_shutdown | RCV_SHUTDOWN;
+
+       cskb = skb;
+       if (skb_copy_datagram_msg(cskb, offset, msg, copied)) {
+               if (!(flags & MSG_PEEK))
+                       skb_queue_head(&sk->sk_receive_queue, skb);
+               return -EFAULT;
+       }
+
+       /* SOCK_SEQPACKET: set MSG_TRUNC if recv buf size is too small */
+       if (sk->sk_type == SOCK_SEQPACKET) {
+               if (copied < rlen)
+                       msg->msg_flags |= MSG_TRUNC;
+               /* each iucv message contains a complete record */
+               msg->msg_flags |= MSG_EOR;
+       }
+
+       /* create control message to store iucv msg target class:
+        * get the trgcls from the control buffer of the skb due to
+        * fragmentation of original iucv message. */
+       err = put_cmsg(msg, SOL_IUCV, SCM_IUCV_TRGCLS,
+                      sizeof(IUCV_SKB_CB(skb)->class),
+                      (void *)&IUCV_SKB_CB(skb)->class);
+       if (err) {
+               if (!(flags & MSG_PEEK))
+                       skb_queue_head(&sk->sk_receive_queue, skb);
+               return err;
+       }
+
+       /* Mark read part of skb as used */
+       if (!(flags & MSG_PEEK)) {
+
+               /* SOCK_STREAM: re-queue skb if it contains unreceived data */
+               if (sk->sk_type == SOCK_STREAM) {
+                       if (copied < rlen) {
+                               IUCV_SKB_CB(skb)->offset = offset + copied;
+                               skb_queue_head(&sk->sk_receive_queue, skb);
+                               goto done;
+                       }
+               }
+
+               kfree_skb(skb);
+               if (iucv->transport == AF_IUCV_TRANS_HIPER) {
+                       atomic_inc(&iucv->msg_recv);
+                       if (atomic_read(&iucv->msg_recv) > iucv->msglimit) {
+                               WARN_ON(1);
+                               iucv_sock_close(sk);
+                               return -EFAULT;
+                       }
+               }
+
+               /* Queue backlog skbs */
+               spin_lock_bh(&iucv->message_q.lock);
+               rskb = skb_dequeue(&iucv->backlog_skb_q);
+               while (rskb) {
+                       IUCV_SKB_CB(rskb)->offset = 0;
+                       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)) {
+                       if (!list_empty(&iucv->message_q.list))
+                               iucv_process_message_q(sk);
+                       if (atomic_read(&iucv->msg_recv) >=
+                                                       iucv->msglimit / 2) {
+                               err = iucv_send_ctrl(sk, AF_IUCV_FLAG_WIN);
+                               if (err) {
+                                       sk->sk_state = IUCV_DISCONN;
+                                       sk->sk_state_change(sk);
+                               }
+                       }
+               }
+               spin_unlock_bh(&iucv->message_q.lock);
+       }
+
+done:
+       /* SOCK_SEQPACKET: return real length if MSG_TRUNC is set */
+       if (sk->sk_type == SOCK_SEQPACKET && (flags & MSG_TRUNC))
+               copied = rlen;
+
+       return 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;
+
+       sock_poll_wait(file, sk_sleep(sk), 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 |
+                       (sock_flag(sk, SOCK_SELECT_ERR_QUEUE) ? POLLPRI : 0);
+
+       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)
+               mask |= POLLIN;
+
+       if (sock_writeable(sk) && iucv_below_msglim(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;
+
+       how++;
+
+       if ((how & ~SHUTDOWN_MASK) || !how)
+               return -EINVAL;
+
+       lock_sock(sk);
+       switch (sk->sk_state) {
+       case IUCV_LISTEN:
+       case IUCV_DISCONN:
+       case IUCV_CLOSING:
+       case IUCV_CLOSED:
+               err = -ENOTCONN;
+               goto fail;
+       default:
+               break;
+       }
+
+       if (how == SEND_SHUTDOWN || how == SHUTDOWN_MASK) {
+               if (iucv->transport == AF_IUCV_TRANS_IUCV) {
+                       txmsg.class = 0;
+                       txmsg.tag = 0;
+                       err = pr_iucv->message_send(iucv->path, &txmsg,
+                               IUCV_IPRMDATA, 0, (void *) iprm_shutdown, 8);
+                       if (err) {
+                               switch (err) {
+                               case 1:
+                                       err = -ENOTCONN;
+                                       break;
+                               case 2:
+                                       err = -ECONNRESET;
+                                       break;
+                               default:
+                                       err = -ENOTCONN;
+                                       break;
+                               }
+                       }
+               } else
+                       iucv_send_ctrl(sk, AF_IUCV_FLAG_SHT);
+       }
+
+       sk->sk_shutdown |= how;
+       if (how == RCV_SHUTDOWN || how == SHUTDOWN_MASK) {
+               if ((iucv->transport == AF_IUCV_TRANS_IUCV) &&
+                   iucv->path) {
+                       err = pr_iucv->path_quiesce(iucv->path, NULL);
+                       if (err)
+                               err = -ENOTCONN;
+/*                     skb_queue_purge(&sk->sk_receive_queue); */
+               }
+               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);
+
+       sock_orphan(sk);
+       iucv_sock_kill(sk);
+       return err;
+}
+
+/* getsockopt and setsockopt */
+static int iucv_sock_setsockopt(struct socket *sock, int level, int optname,
+                               char __user *optval, unsigned int optlen)
+{
+       struct sock *sk = sock->sk;
+       struct iucv_sock *iucv = iucv_sk(sk);
+       int val;
+       int rc;
+
+       if (level != SOL_IUCV)
+               return -ENOPROTOOPT;
+
+       if (optlen < sizeof(int))
+               return -EINVAL;
+
+       if (get_user(val, (int __user *) optval))
+               return -EFAULT;
+
+       rc = 0;
+
+       lock_sock(sk);
+       switch (optname) {
+       case SO_IPRMDATA_MSG:
+               if (val)
+                       iucv->flags |= IUCV_IPRMDATA;
+               else
+                       iucv->flags &= ~IUCV_IPRMDATA;
+               break;
+       case SO_MSGLIMIT:
+               switch (sk->sk_state) {
+               case IUCV_OPEN:
+               case IUCV_BOUND:
+                       if (val < 1 || val > (u16)(~0))
+                               rc = -EINVAL;
+                       else
+                               iucv->msglimit = val;
+                       break;
+               default:
+                       rc = -EINVAL;
+                       break;
+               }
+               break;
+       default:
+               rc = -ENOPROTOOPT;
+               break;
+       }
+       release_sock(sk);
+
+       return rc;
+}
+
+static int iucv_sock_getsockopt(struct socket *sock, int level, int optname,
+                               char __user *optval, int __user *optlen)
+{
+       struct sock *sk = sock->sk;
+       struct iucv_sock *iucv = iucv_sk(sk);
+       unsigned int val;
+       int len;
+
+       if (level != SOL_IUCV)
+               return -ENOPROTOOPT;
+
+       if (get_user(len, optlen))
+               return -EFAULT;
+
+       if (len < 0)
+               return -EINVAL;
+
+       len = min_t(unsigned int, len, sizeof(int));
+
+       switch (optname) {
+       case SO_IPRMDATA_MSG:
+               val = (iucv->flags & IUCV_IPRMDATA) ? 1 : 0;
+               break;
+       case SO_MSGLIMIT:
+               lock_sock(sk);
+               val = (iucv->path != NULL) ? iucv->path->msglim /* connected */
+                                          : iucv->msglimit;    /* default */
+               release_sock(sk);
+               break;
+       case SO_MSGSIZE:
+               if (sk->sk_state == IUCV_OPEN)
+                       return -EBADFD;
+               val = (iucv->hs_dev) ? iucv->hs_dev->mtu -
+                               sizeof(struct af_iucv_trans_hdr) - ETH_HLEN :
+                               0x7fffffff;
+               break;
+       default:
+               return -ENOPROTOOPT;
+       }
+
+       if (put_user(len, optlen))
+               return -EFAULT;
+       if (copy_to_user(optval, &val, len))
+               return -EFAULT;
+
+       return 0;
+}
+
+
+/* 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 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, &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 = pr_iucv->path_sever(path, user_data);
+               iucv_path_free(path);
+               goto fail;
+       }
+
+       /* Check for backlog size */
+       if (sk_acceptq_is_full(sk)) {
+               err = pr_iucv->path_sever(path, user_data);
+               iucv_path_free(path);
+               goto fail;
+       }
+
+       /* Create the new socket */
+       nsk = iucv_sock_alloc(NULL, sk->sk_type, GFP_ATOMIC);
+       if (!nsk) {
+               err = pr_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);
+
+       /* set message limit for path based on msglimit of accepting socket */
+       niucv->msglimit = iucv->msglimit;
+       path->msglim = iucv->msglimit;
+       err = pr_iucv->path_accept(path, &af_iucv_handler, nuser_data, nsk);
+       if (err) {
+               iucv_sever_path(nsk, 1);
+               iucv_sock_kill(nsk);
+               goto fail;
+       }
+
+       iucv_accept_enqueue(sk, nsk);
+
+       /* Wake up accept */
+       nsk->sk_state = IUCV_CONNECTED;
+       sk->sk_data_ready(sk);
+       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) {
+               pr_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 += SKB_TRUESIZE(iucv_msg_length(msg));
+       if (len > sk->sk_rcvbuf)
+               goto save_message;
+
+       skb = alloc_skb(iucv_msg_length(msg), GFP_ATOMIC | GFP_DMA);
+       if (!skb)
+               goto save_message;
+
+       iucv_process_message(sk, skb, path, msg);
+       goto out_unlock;
+
+save_message:
+       save_msg = kzalloc(sizeof(struct sock_msg_q), GFP_ATOMIC | GFP_DMA);
+       if (!save_msg)
+               goto out_unlock;
+       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;
+
+       bh_lock_sock(sk);
+       if (!skb_queue_empty(list)) {
+               spin_lock_irqsave(&list->lock, flags);
+
+               while (list_skb != (struct sk_buff *)list) {
+                       if (msg->tag == IUCV_SKB_CB(list_skb)->tag) {
+                               this = list_skb;
+                               break;
+                       }
+                       list_skb = list_skb->next;
+               }
+               if (this)
+                       __skb_unlink(this, list);
+
+               spin_unlock_irqrestore(&list->lock, flags);
+
+               if (this) {
+                       kfree_skb(this);
+                       /* wake up any process waiting for sending */
+                       iucv_sock_wake_msglim(sk);
+               }
+       }
+
+       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);
+               }
+       }
+       bh_unlock_sock(sk);
+
+}
+
+static void iucv_callback_connrej(struct iucv_path *path, u8 ipuser[16])
+{
+       struct sock *sk = path->private;
+
+       if (sk->sk_state == IUCV_CLOSED)
+               return;
+
+       bh_lock_sock(sk);
+       iucv_sever_path(sk, 1);
+       sk->sk_state = IUCV_DISCONN;
+
+       sk->sk_state_change(sk);
+       bh_unlock_sock(sk);
+}
+
+/* called if the other communication side shuts down its RECV direction;
+ * in turn, the callback sets SEND_SHUTDOWN to disable sending of data.
+ */
+static void iucv_callback_shutdown(struct iucv_path *path, u8 ipuser[16])
+{
+       struct sock *sk = path->private;
+
+       bh_lock_sock(sk);
+       if (sk->sk_state != IUCV_CLOSED) {
+               sk->sk_shutdown |= SEND_SHUTDOWN;
+               sk->sk_state_change(sk);
+       }
+       bh_unlock_sock(sk);
+}
+
+/***************** HiperSockets transport callbacks ********************/
+static void afiucv_swap_src_dest(struct sk_buff *skb)
+{
+       struct af_iucv_trans_hdr *trans_hdr =
+                               (struct af_iucv_trans_hdr *)skb->data;
+       char tmpID[8];
+       char tmpName[8];
+
+       ASCEBC(trans_hdr->destUserID, sizeof(trans_hdr->destUserID));
+       ASCEBC(trans_hdr->destAppName, sizeof(trans_hdr->destAppName));
+       ASCEBC(trans_hdr->srcUserID, sizeof(trans_hdr->srcUserID));
+       ASCEBC(trans_hdr->srcAppName, sizeof(trans_hdr->srcAppName));
+       memcpy(tmpID, trans_hdr->srcUserID, 8);
+       memcpy(tmpName, trans_hdr->srcAppName, 8);
+       memcpy(trans_hdr->srcUserID, trans_hdr->destUserID, 8);
+       memcpy(trans_hdr->srcAppName, trans_hdr->destAppName, 8);
+       memcpy(trans_hdr->destUserID, tmpID, 8);
+       memcpy(trans_hdr->destAppName, tmpName, 8);
+       skb_push(skb, ETH_HLEN);
+       memset(skb->data, 0, ETH_HLEN);
+}
+
+/**
+ * afiucv_hs_callback_syn - react on received SYN
+ **/
+static int afiucv_hs_callback_syn(struct sock *sk, struct sk_buff *skb)
+{
+       struct sock *nsk;
+       struct iucv_sock *iucv, *niucv;
+       struct af_iucv_trans_hdr *trans_hdr;
+       int err;
+
+       iucv = iucv_sk(sk);
+       trans_hdr = (struct af_iucv_trans_hdr *)skb->data;
+       if (!iucv) {
+               /* no sock - connection refused */
+               afiucv_swap_src_dest(skb);
+               trans_hdr->flags = AF_IUCV_FLAG_SYN | AF_IUCV_FLAG_FIN;
+               err = dev_queue_xmit(skb);
+               goto out;
+       }
+
+       nsk = iucv_sock_alloc(NULL, sk->sk_type, GFP_ATOMIC);
+       bh_lock_sock(sk);
+       if ((sk->sk_state != IUCV_LISTEN) ||
+           sk_acceptq_is_full(sk) ||
+           !nsk) {
+               /* error on server socket - connection refused */
+               afiucv_swap_src_dest(skb);
+               trans_hdr->flags = AF_IUCV_FLAG_SYN | AF_IUCV_FLAG_FIN;
+               err = dev_queue_xmit(skb);
+               iucv_sock_kill(nsk);
+               bh_unlock_sock(sk);
+               goto out;
+       }
+
+       niucv = iucv_sk(nsk);
+       iucv_sock_init(nsk, sk);
+       niucv->transport = AF_IUCV_TRANS_HIPER;
+       niucv->msglimit = iucv->msglimit;
+       if (!trans_hdr->window)
+               niucv->msglimit_peer = IUCV_HIPER_MSGLIM_DEFAULT;
+       else
+               niucv->msglimit_peer = trans_hdr->window;
+       memcpy(niucv->dst_name, trans_hdr->srcAppName, 8);
+       memcpy(niucv->dst_user_id, trans_hdr->srcUserID, 8);
+       memcpy(niucv->src_name, iucv->src_name, 8);
+       memcpy(niucv->src_user_id, iucv->src_user_id, 8);
+       nsk->sk_bound_dev_if = sk->sk_bound_dev_if;
+       niucv->hs_dev = iucv->hs_dev;
+       dev_hold(niucv->hs_dev);
+       afiucv_swap_src_dest(skb);
+       trans_hdr->flags = AF_IUCV_FLAG_SYN | AF_IUCV_FLAG_ACK;
+       trans_hdr->window = niucv->msglimit;
+       /* if receiver acks the xmit connection is established */
+       err = dev_queue_xmit(skb);
+       if (!err) {
+               iucv_accept_enqueue(sk, nsk);
+               nsk->sk_state = IUCV_CONNECTED;
+               sk->sk_data_ready(sk);
+       } else
+               iucv_sock_kill(nsk);
+       bh_unlock_sock(sk);
+
+out:
+       return NET_RX_SUCCESS;
+}
+
+/**
+ * afiucv_hs_callback_synack() - react on received SYN-ACK
+ **/
+static int afiucv_hs_callback_synack(struct sock *sk, struct sk_buff *skb)
+{
+       struct iucv_sock *iucv = iucv_sk(sk);
+       struct af_iucv_trans_hdr *trans_hdr =
+                                       (struct af_iucv_trans_hdr *)skb->data;
+
+       if (!iucv)
+               goto out;
+       if (sk->sk_state != IUCV_BOUND)
+               goto out;
+       bh_lock_sock(sk);
+       iucv->msglimit_peer = trans_hdr->window;
+       sk->sk_state = IUCV_CONNECTED;
+       sk->sk_state_change(sk);
+       bh_unlock_sock(sk);
+out:
+       kfree_skb(skb);
+       return NET_RX_SUCCESS;
+}
+
+/**
+ * afiucv_hs_callback_synfin() - react on received SYN_FIN
+ **/
+static int afiucv_hs_callback_synfin(struct sock *sk, struct sk_buff *skb)
+{
+       struct iucv_sock *iucv = iucv_sk(sk);
+
+       if (!iucv)
+               goto out;
+       if (sk->sk_state != IUCV_BOUND)
+               goto out;
+       bh_lock_sock(sk);
+       sk->sk_state = IUCV_DISCONN;
+       sk->sk_state_change(sk);
+       bh_unlock_sock(sk);
+out:
+       kfree_skb(skb);
+       return NET_RX_SUCCESS;
+}
+
+/**
+ * afiucv_hs_callback_fin() - react on received FIN
+ **/
+static int afiucv_hs_callback_fin(struct sock *sk, struct sk_buff *skb)
+{
+       struct iucv_sock *iucv = iucv_sk(sk);
+
+       /* other end of connection closed */
+       if (!iucv)
+               goto out;
+       bh_lock_sock(sk);
+       if (sk->sk_state == IUCV_CONNECTED) {
+               sk->sk_state = IUCV_DISCONN;
+               sk->sk_state_change(sk);
+       }
+       bh_unlock_sock(sk);
+out:
+       kfree_skb(skb);
+       return NET_RX_SUCCESS;
+}
+
+/**
+ * afiucv_hs_callback_win() - react on received WIN
+ **/
+static int afiucv_hs_callback_win(struct sock *sk, struct sk_buff *skb)
+{
+       struct iucv_sock *iucv = iucv_sk(sk);
+       struct af_iucv_trans_hdr *trans_hdr =
+                                       (struct af_iucv_trans_hdr *)skb->data;
+
+       if (!iucv)
+               return NET_RX_SUCCESS;
+
+       if (sk->sk_state != IUCV_CONNECTED)
+               return NET_RX_SUCCESS;
+
+       atomic_sub(trans_hdr->window, &iucv->msg_sent);
+       iucv_sock_wake_msglim(sk);
+       return NET_RX_SUCCESS;
+}
+
+/**
+ * afiucv_hs_callback_rx() - react on received data
+ **/
+static int afiucv_hs_callback_rx(struct sock *sk, struct sk_buff *skb)
+{
+       struct iucv_sock *iucv = iucv_sk(sk);
+
+       if (!iucv) {
+               kfree_skb(skb);
+               return NET_RX_SUCCESS;
+       }
+
+       if (sk->sk_state != IUCV_CONNECTED) {
+               kfree_skb(skb);
+               return NET_RX_SUCCESS;
+       }
+
+       if (sk->sk_shutdown & RCV_SHUTDOWN) {
+               kfree_skb(skb);
+               return NET_RX_SUCCESS;
+       }
+
+               /* write stuff from iucv_msg to skb cb */
+       if (skb->len < sizeof(struct af_iucv_trans_hdr)) {
+               kfree_skb(skb);
+               return NET_RX_SUCCESS;
+       }
+       skb_pull(skb, sizeof(struct af_iucv_trans_hdr));
+       skb_reset_transport_header(skb);
+       skb_reset_network_header(skb);
+       IUCV_SKB_CB(skb)->offset = 0;
+       spin_lock(&iucv->message_q.lock);
+       if (skb_queue_empty(&iucv->backlog_skb_q)) {
+               if (sock_queue_rcv_skb(sk, skb)) {
+                       /* handle rcv queue full */
+                       skb_queue_tail(&iucv->backlog_skb_q, skb);
+               }
+       } else
+               skb_queue_tail(&iucv_sk(sk)->backlog_skb_q, skb);
+       spin_unlock(&iucv->message_q.lock);
+       return NET_RX_SUCCESS;
+}
+
+/**
+ * afiucv_hs_rcv() - base function for arriving data through HiperSockets
+ *                   transport
+ *                   called from netif RX softirq
+ **/
+static int afiucv_hs_rcv(struct sk_buff *skb, struct net_device *dev,
+       struct packet_type *pt, struct net_device *orig_dev)
+{
+       struct sock *sk;
+       struct iucv_sock *iucv;
+       struct af_iucv_trans_hdr *trans_hdr;
+       char nullstring[8];
+       int err = 0;
+
+       skb_pull(skb, ETH_HLEN);
+       trans_hdr = (struct af_iucv_trans_hdr *)skb->data;
+       EBCASC(trans_hdr->destAppName, sizeof(trans_hdr->destAppName));
+       EBCASC(trans_hdr->destUserID, sizeof(trans_hdr->destUserID));
+       EBCASC(trans_hdr->srcAppName, sizeof(trans_hdr->srcAppName));
+       EBCASC(trans_hdr->srcUserID, sizeof(trans_hdr->srcUserID));
+       memset(nullstring, 0, sizeof(nullstring));
+       iucv = NULL;
+       sk = NULL;
+       read_lock(&iucv_sk_list.lock);
+       sk_for_each(sk, &iucv_sk_list.head) {
+               if (trans_hdr->flags == AF_IUCV_FLAG_SYN) {
+                       if ((!memcmp(&iucv_sk(sk)->src_name,
+                                    trans_hdr->destAppName, 8)) &&
+                           (!memcmp(&iucv_sk(sk)->src_user_id,
+                                    trans_hdr->destUserID, 8)) &&
+                           (!memcmp(&iucv_sk(sk)->dst_name, nullstring, 8)) &&
+                           (!memcmp(&iucv_sk(sk)->dst_user_id,
+                                    nullstring, 8))) {
+                               iucv = iucv_sk(sk);
+                               break;
+                       }
+               } else {
+                       if ((!memcmp(&iucv_sk(sk)->src_name,
+                                    trans_hdr->destAppName, 8)) &&
+                           (!memcmp(&iucv_sk(sk)->src_user_id,
+                                    trans_hdr->destUserID, 8)) &&
+                           (!memcmp(&iucv_sk(sk)->dst_name,
+                                    trans_hdr->srcAppName, 8)) &&
+                           (!memcmp(&iucv_sk(sk)->dst_user_id,
+                                    trans_hdr->srcUserID, 8))) {
+                               iucv = iucv_sk(sk);
+                               break;
+                       }
+               }
+       }
+       read_unlock(&iucv_sk_list.lock);
+       if (!iucv)
+               sk = NULL;
+
+       /* no sock
+       how should we send with no sock
+       1) send without sock no send rc checking?
+       2) introduce default sock to handle this cases
+
+        SYN -> send SYN|ACK in good case, send SYN|FIN in bad case
+        data -> send FIN
+        SYN|ACK, SYN|FIN, FIN -> no action? */
+
+       switch (trans_hdr->flags) {
+       case AF_IUCV_FLAG_SYN:
+               /* connect request */
+               err = afiucv_hs_callback_syn(sk, skb);
+               break;
+       case (AF_IUCV_FLAG_SYN | AF_IUCV_FLAG_ACK):
+               /* connect request confirmed */
+               err = afiucv_hs_callback_synack(sk, skb);
+               break;
+       case (AF_IUCV_FLAG_SYN | AF_IUCV_FLAG_FIN):
+               /* connect request refused */
+               err = afiucv_hs_callback_synfin(sk, skb);
+               break;
+       case (AF_IUCV_FLAG_FIN):
+               /* close request */
+               err = afiucv_hs_callback_fin(sk, skb);
+               break;
+       case (AF_IUCV_FLAG_WIN):
+               err = afiucv_hs_callback_win(sk, skb);
+               if (skb->len == sizeof(struct af_iucv_trans_hdr)) {
+                       kfree_skb(skb);
+                       break;
+               }
+               /* fall through and receive non-zero length data */
+       case (AF_IUCV_FLAG_SHT):
+               /* shutdown request */
+               /* fall through and receive zero length data */
+       case 0:
+               /* plain data frame */
+               IUCV_SKB_CB(skb)->class = trans_hdr->iucv_hdr.class;
+               err = afiucv_hs_callback_rx(sk, skb);
+               break;
+       default:
+               ;
+       }
+
+       return err;
+}
+
+/**
+ * afiucv_hs_callback_txnotify() - handle send notifcations from HiperSockets
+ *                                 transport
+ **/
+static void afiucv_hs_callback_txnotify(struct sk_buff *skb,
+                                       enum iucv_tx_notify n)
+{
+       struct sock *isk = skb->sk;
+       struct sock *sk = NULL;
+       struct iucv_sock *iucv = NULL;
+       struct sk_buff_head *list;
+       struct sk_buff *list_skb;
+       struct sk_buff *nskb;
+       unsigned long flags;
+
+       read_lock_irqsave(&iucv_sk_list.lock, flags);
+       sk_for_each(sk, &iucv_sk_list.head)
+               if (sk == isk) {
+                       iucv = iucv_sk(sk);
+                       break;
+               }
+       read_unlock_irqrestore(&iucv_sk_list.lock, flags);
+
+       if (!iucv || sock_flag(sk, SOCK_ZAPPED))
+               return;
+
+       list = &iucv->send_skb_q;
+       spin_lock_irqsave(&list->lock, flags);
+       if (skb_queue_empty(list))
+               goto out_unlock;
+       list_skb = list->next;
+       nskb = list_skb->next;
+       while (list_skb != (struct sk_buff *)list) {
+               if (skb_shinfo(list_skb) == skb_shinfo(skb)) {
+                       switch (n) {
+                       case TX_NOTIFY_OK:
+                               __skb_unlink(list_skb, list);
+                               kfree_skb(list_skb);
+                               iucv_sock_wake_msglim(sk);
+                               break;
+                       case TX_NOTIFY_PENDING:
+                               atomic_inc(&iucv->pendings);
+                               break;
+                       case TX_NOTIFY_DELAYED_OK:
+                               __skb_unlink(list_skb, list);
+                               atomic_dec(&iucv->pendings);
+                               if (atomic_read(&iucv->pendings) <= 0)
+                                       iucv_sock_wake_msglim(sk);
+                               kfree_skb(list_skb);
+                               break;
+                       case TX_NOTIFY_UNREACHABLE:
+                       case TX_NOTIFY_DELAYED_UNREACHABLE:
+                       case TX_NOTIFY_TPQFULL: /* not yet used */
+                       case TX_NOTIFY_GENERALERROR:
+                       case TX_NOTIFY_DELAYED_GENERALERROR:
+                               __skb_unlink(list_skb, list);
+                               kfree_skb(list_skb);
+                               if (sk->sk_state == IUCV_CONNECTED) {
+                                       sk->sk_state = IUCV_DISCONN;
+                                       sk->sk_state_change(sk);
+                               }
+                               break;
+                       }
+                       break;
+               }
+               list_skb = nskb;
+               nskb = nskb->next;
+       }
+out_unlock:
+       spin_unlock_irqrestore(&list->lock, flags);
+
+       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);
+               }
+       }
+
+}
+
+/*
+ * afiucv_netdev_event: handle netdev notifier chain events
+ */
+static int afiucv_netdev_event(struct notifier_block *this,
+                              unsigned long event, void *ptr)
+{
+       struct net_device *event_dev = netdev_notifier_info_to_dev(ptr);
+       struct sock *sk;
+       struct iucv_sock *iucv;
+
+       switch (event) {
+       case NETDEV_REBOOT:
+       case NETDEV_GOING_DOWN:
+               sk_for_each(sk, &iucv_sk_list.head) {
+                       iucv = iucv_sk(sk);
+                       if ((iucv->hs_dev == event_dev) &&
+                           (sk->sk_state == IUCV_CONNECTED)) {
+                               if (event == NETDEV_GOING_DOWN)
+                                       iucv_send_ctrl(sk, AF_IUCV_FLAG_FIN);
+                               sk->sk_state = IUCV_DISCONN;
+                               sk->sk_state_change(sk);
+                       }
+               }
+               break;
+       case NETDEV_DOWN:
+       case NETDEV_UNREGISTER:
+       default:
+               break;
+       }
+       return NOTIFY_DONE;
+}
+
+static struct notifier_block afiucv_netdev_notifier = {
+       .notifier_call = afiucv_netdev_event,
+};
+
+static const 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     = iucv_sock_setsockopt,
+       .getsockopt     = iucv_sock_getsockopt,
+};
+
+static const struct net_proto_family iucv_sock_family_ops = {
+       .family = AF_IUCV,
+       .owner  = THIS_MODULE,
+       .create = iucv_sock_create,
+};
+
+static struct packet_type iucv_packet_type = {
+       .type = cpu_to_be16(ETH_P_AF_IUCV),
+       .func = afiucv_hs_rcv,
+};
+
+static int afiucv_iucv_init(void)
+{
+       int err;
+
+       err = pr_iucv->iucv_register(&af_iucv_handler, 0);
+       if (err)
+               goto out;
+       /* establish dummy device */
+       af_iucv_driver.bus = pr_iucv->bus;
+       err = driver_register(&af_iucv_driver);
+       if (err)
+               goto out_iucv;
+       af_iucv_dev = kzalloc(sizeof(struct device), GFP_KERNEL);
+       if (!af_iucv_dev) {
+               err = -ENOMEM;
+               goto out_driver;
+       }
+       dev_set_name(af_iucv_dev, "af_iucv");
+       af_iucv_dev->bus = pr_iucv->bus;
+       af_iucv_dev->parent = pr_iucv->root;
+       af_iucv_dev->release = (void (*)(struct device *))kfree;
+       af_iucv_dev->driver = &af_iucv_driver;
+       err = device_register(af_iucv_dev);
+       if (err)
+               goto out_driver;
+       return 0;
+
+out_driver:
+       driver_unregister(&af_iucv_driver);
+out_iucv:
+       pr_iucv->iucv_unregister(&af_iucv_handler, 0);
+out:
+       return err;
+}
+
+static int __init afiucv_init(void)
+{
+       int err;
+
+       if (MACHINE_IS_VM) {
+               cpcmd("QUERY USERID", iucv_userid, sizeof(iucv_userid), &err);
+               if (unlikely(err)) {
+                       WARN_ON(err);
+                       err = -EPROTONOSUPPORT;
+                       goto out;
+               }
+
+               pr_iucv = try_then_request_module(symbol_get(iucv_if), "iucv");
+               if (!pr_iucv) {
+                       printk(KERN_WARNING "iucv_if lookup failed\n");
+                       memset(&iucv_userid, 0, sizeof(iucv_userid));
+               }
+       } else {
+               memset(&iucv_userid, 0, sizeof(iucv_userid));
+               pr_iucv = NULL;
+       }
+
+       err = proto_register(&iucv_proto, 0);
+       if (err)
+               goto out;
+       err = sock_register(&iucv_sock_family_ops);
+       if (err)
+               goto out_proto;
+
+       if (pr_iucv) {
+               err = afiucv_iucv_init();
+               if (err)
+                       goto out_sock;
+       } else
+               register_netdevice_notifier(&afiucv_netdev_notifier);
+       dev_add_pack(&iucv_packet_type);
+       return 0;
+
+out_sock:
+       sock_unregister(PF_IUCV);
+out_proto:
+       proto_unregister(&iucv_proto);
+out:
+       if (pr_iucv)
+               symbol_put(iucv_if);
+       return err;
+}
+
+static void __exit afiucv_exit(void)
+{
+       if (pr_iucv) {
+               device_unregister(af_iucv_dev);
+               driver_unregister(&af_iucv_driver);
+               pr_iucv->iucv_unregister(&af_iucv_handler, 0);
+               symbol_put(iucv_if);
+       } else
+               unregister_netdevice_notifier(&afiucv_netdev_notifier);
+       dev_remove_pack(&iucv_packet_type);
+       sock_unregister(PF_IUCV);
+       proto_unregister(&iucv_proto);
+}
+
+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);
+