af_iucv: add HiperSockets transport

The current transport mechanism for af_iucv is the z/VM offered
communications facility IUCV. To provide equivalent support when
running Linux in an LPAR, HiperSockets transport is added to the
AF_IUCV address family. It requires explicit binding of an AF_IUCV
socket to a HiperSockets device. A new packet_type ETH_P_AF_IUCV
is announced. An af_iucv specific transport header is defined
preceding the skb data. A small protocol is implemented for
connecting and for flow control/congestion management.

Signed-off-by: Ursula Braun <ursula.braun@de.ibm.com>
Signed-off-by: Frank Blaschka <frank.blaschka@de.ibm.com>
Reviewed-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 677 insertions, 72 deletions

diff --git a/net/iucv/af_iucv.c b/net/iucv/af_iucv.c
index 1d8cb72da3a4..c39f3a43cd80 100644
--- a/net/iucv/af_iucv.c
+++ b/net/iucv/af_iucv.c
@@ -27,10 +27,9 @@
 #include <asm/cpcmd.h>
 #include <linux/kmod.h>
 
-#include <net/iucv/iucv.h>
 #include <net/iucv/af_iucv.h>
 
-#define VERSION "1.1"
+#define VERSION "1.2"
 
 static char iucv_userid[80];
 
@@ -92,6 +91,12 @@ do {									\
 static void iucv_sock_kill(struct sock *sk);
 static void iucv_sock_close(struct sock *sk);
 
+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 *);
@@ -296,7 +301,11 @@ static inline int iucv_below_msglim(struct sock *sk)
 
         if (sk->sk_state != IUCV_CONNECTED)
                 return 1;
-        return (skb_queue_len(&iucv->send_skb_q) < iucv->path->msglim);
+        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));
 }
 
 /**
@@ -314,6 +323,79 @@ static void iucv_sock_wake_msglim(struct sock *sk)
         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 net *net = sock_net(sock);
+        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));
+
+        rcu_read_lock();
+        skb->dev = dev_get_by_index_rcu(net, sock->sk_bound_dev_if);
+        rcu_read_unlock();
+        if (!skb->dev)
+                return -ENODEV;
+        if (!(skb->dev->flags & IFF_UP))
+                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;
+        skb_shinfo(skb)->tx_flags |= SKBTX_DRV_NEEDS_SK_REF;
+        nskb = skb_clone(skb, GFP_ATOMIC);
+        if (!nskb)
+                return -ENOMEM;
+        skb_queue_tail(&iucv->send_skb_q, nskb);
+        err = dev_queue_xmit(skb);
+        if (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 err;
+}
+
 /* Timers */
 static void iucv_sock_timeout(unsigned long arg)
 {
@@ -382,6 +464,8 @@ static void iucv_sock_close(struct sock *sk)
         unsigned char user_data[16];
         struct iucv_sock *iucv = iucv_sk(sk);
         unsigned long timeo;
+        int err, blen;
+        struct sk_buff *skb;
 
         iucv_sock_clear_timer(sk);
         lock_sock(sk);
@@ -392,6 +476,20 @@ static void iucv_sock_close(struct sock *sk)
                 break;
 
         case IUCV_CONNECTED:
+                if (iucv->transport == AF_IUCV_TRANS_HIPER) {
+                        /* send fin */
+                        blen = sizeof(struct af_iucv_trans_hdr) + ETH_HLEN;
+                        skb = sock_alloc_send_skb(sk, blen, 1, &err);
+                        if (skb) {
+                                skb_reserve(skb,
+                                        sizeof(struct af_iucv_trans_hdr) +
+                                        ETH_HLEN);
+                                err = afiucv_hs_send(NULL, sk, skb,
+                                                     AF_IUCV_FLAG_FIN);
+                        }
+                        sk->sk_state = IUCV_DISCONN;
+                        sk->sk_state_change(sk);
+                }
         case IUCV_DISCONN:
                 sk->sk_state = IUCV_CLOSING;
                 sk->sk_state_change(sk);
@@ -461,10 +559,18 @@ static struct sock *iucv_sock_alloc(struct socket *sock, int proto, gfp_t prio)
         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 = IUCV_QUEUELEN_DEFAULT;
+        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;
@@ -595,7 +701,9 @@ static int iucv_sock_bind(struct socket *sock, struct sockaddr *addr,
         struct sockaddr_iucv *sa = (struct sockaddr_iucv *) addr;
         struct sock *sk = sock->sk;
         struct iucv_sock *iucv;
-        int err;
+        int err = 0;
+        struct net_device *dev;
+        char uid[9];
 
         /* Verify the input sockaddr */
         if (!addr || addr->sa_family != AF_IUCV)
@@ -614,19 +722,46 @@ static int iucv_sock_bind(struct socket *sock, struct sockaddr *addr,
                 err = -EADDRINUSE;
                 goto done_unlock;
         }
-        if (iucv->path) {
-                err = 0;
+        if (iucv->path)
                 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;
+        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_name, sa->siucv_name, 8);
+                        memcpy(iucv->src_user_id, sa->siucv_user_id, 8);
+                        sock->sk->sk_bound_dev_if = dev->ifindex;
+                        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);
@@ -662,12 +797,33 @@ static int iucv_sock_autobind(struct sock *sk)
 
         memcpy(&iucv->src_name, name, 8);
 
+        if (!iucv->msglimit)
+                iucv->msglimit = IUCV_QUEUELEN_DEFAULT;
+
         return err;
 }
 
-/* Connect an unconnected socket */
-static int iucv_sock_connect(struct socket *sock, struct sockaddr *addr,
-                             int alen, int flags)
+static int afiucv_hs_connect(struct socket *sock)
+{
+        struct sock *sk = sock->sk;
+        struct sk_buff *skb;
+        int blen = sizeof(struct af_iucv_trans_hdr) + ETH_HLEN;
+        int err = 0;
+
+        /* send syn */
+        skb = sock_alloc_send_skb(sk, blen, 1, &err);
+        if (!skb) {
+                err = -ENOMEM;
+                goto done;
+        }
+        skb->dev = NULL;
+        skb_reserve(skb, blen);
+        err = afiucv_hs_send(NULL, sk, skb, AF_IUCV_FLAG_SYN);
+done:
+        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;
@@ -675,27 +831,6 @@ static int iucv_sock_connect(struct socket *sock, struct sockaddr *addr,
         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 && 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);
-
         high_nmcpy(user_data, sa->siucv_name);
         low_nmcpy(user_data, iucv->src_name);
         ASCEBC(user_data, sizeof(user_data));
@@ -728,20 +863,61 @@ static int iucv_sock_connect(struct socket *sock, struct sockaddr *addr,
                         err = -ECONNREFUSED;
                         break;
                 }
-                goto done;
         }
+done:
+        return err;
+}
 
-        if (sk->sk_state != IUCV_CONNECTED) {
+/* 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 = afiucv_hs_connect(sock);
+        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) {
+        if (sk->sk_state == IUCV_DISCONN || sk->sk_state == IUCV_CLOSED)
                 err = -ECONNREFUSED;
-        }
 
-        if (err) {
+        if (err && iucv->transport == AF_IUCV_TRANS_IUCV) {
                 pr_iucv->path_sever(iucv->path, NULL);
                 iucv_path_free(iucv->path);
                 iucv->path = NULL;
@@ -965,9 +1141,16 @@ static int iucv_sock_sendmsg(struct kiocb *iocb, struct socket *sock,
          * 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 */
-        skb = sock_alloc_send_skb(sk, len, noblock, &err);
+        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_fromiovec(skb_put(skb, len), msg->msg_iov, len)) {
                 err = -EFAULT;
                 goto fail;
@@ -988,6 +1171,15 @@ static int iucv_sock_sendmsg(struct kiocb *iocb, struct socket *sock,
         /* increment and save iucv message tag for msg_completion cbk */
         txmsg.tag = iucv->send_tag++;
         memcpy(CB_TAG(skb), &txmsg.tag, CB_TAG_LEN);
+        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)
@@ -1028,6 +1220,7 @@ static int iucv_sock_sendmsg(struct kiocb *iocb, struct socket *sock,
                 goto fail;
         }
 
+release:
         release_sock(sk);
         return len;
 
@@ -1160,7 +1353,8 @@ static int iucv_sock_recvmsg(struct kiocb *iocb, struct socket *sock,
         struct sock *sk = sock->sk;
         struct iucv_sock *iucv = iucv_sk(sk);
         unsigned int copied, rlen;
-        struct sk_buff *skb, *rskb, *cskb;
+        struct sk_buff *skb, *rskb, *cskb, *sskb;
+        int blen;
         int err = 0;
 
         if ((sk->sk_state == IUCV_DISCONN || sk->sk_state == IUCV_SEVERED) &&
@@ -1185,7 +1379,7 @@ static int iucv_sock_recvmsg(struct kiocb *iocb, struct socket *sock,
         copied = min_t(unsigned int, rlen, len);
 
         cskb = skb;
-        if (memcpy_toiovec(msg->msg_iov, cskb->data, copied)) {
+        if (skb_copy_datagram_iovec(cskb, 0, msg->msg_iov, copied)) {
                 if (!(flags & MSG_PEEK))
                         skb_queue_head(&sk->sk_receive_queue, skb);
                 return -EFAULT;
@@ -1223,6 +1417,7 @@ static int iucv_sock_recvmsg(struct kiocb *iocb, struct socket *sock,
                 }
 
                 kfree_skb(skb);
+                atomic_inc(&iucv->msg_recv);
 
                 /* Queue backlog skbs */
                 spin_lock_bh(&iucv->message_q.lock);
@@ -1239,6 +1434,24 @@ static int iucv_sock_recvmsg(struct kiocb *iocb, struct socket *sock,
                 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) {
+                                /* send WIN to peer */
+                                blen = sizeof(struct af_iucv_trans_hdr) +
+                                        ETH_HLEN;
+                                sskb = sock_alloc_send_skb(sk, blen, 1, &err);
+                                if (sskb) {
+                                        skb_reserve(sskb,
+                                                sizeof(struct af_iucv_trans_hdr)
+                                                + ETH_HLEN);
+                                        err = afiucv_hs_send(NULL, sk, sskb,
+                                                             AF_IUCV_FLAG_WIN);
+                                }
+                                if (err) {
+                                        sk->sk_state = IUCV_DISCONN;
+                                        sk->sk_state_change(sk);
+                                }
+                        }
                 }
                 spin_unlock_bh(&iucv->message_q.lock);
         }
@@ -1698,6 +1911,389 @@ static void iucv_callback_shutdown(struct iucv_path *path, u8 ipuser[16])
         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 */
+                if (nsk)
+                        sk_free(nsk);
+                afiucv_swap_src_dest(skb);
+                trans_hdr->flags = AF_IUCV_FLAG_SYN | AF_IUCV_FLAG_FIN;
+                err = dev_queue_xmit(skb);
+                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;
+        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, 1);
+        } 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) {
+                bh_lock_sock(sk);
+                if (!list_empty(&iucv->accept_q))
+                        sk->sk_state = IUCV_SEVERED;
+                else
+                        sk->sk_state = IUCV_DISCONN;
+                sk->sk_state_change(sk);
+                bh_unlock_sock(sk);
+        }
+        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;
+        }
+
+                /* 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);
+        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 hlist_node *node;
+        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, node, &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))
+                        err = afiucv_hs_callback_rx(sk, skb);
+                else
+                        kfree(skb);
+                break;
+        case 0:
+                /* plain data frame */
+                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 *this = NULL;
+        unsigned long flags;
+        struct hlist_node *node;
+
+        read_lock(&iucv_sk_list.lock);
+        sk_for_each(sk, node, &iucv_sk_list.head)
+                if (sk == isk) {
+                        iucv = iucv_sk(sk);
+                        break;
+                }
+        read_unlock(&iucv_sk_list.lock);
+
+        if (!iucv)
+                return;
+
+        bh_lock_sock(sk);
+        list = &iucv->send_skb_q;
+        list_skb = list->next;
+        if (skb_queue_empty(list))
+                goto out_unlock;
+
+        spin_lock_irqsave(&list->lock, flags);
+        while (list_skb != (struct sk_buff *)list) {
+                if (skb_shinfo(list_skb) == skb_shinfo(skb)) {
+                        this = list_skb;
+                        switch (n) {
+                        case TX_NOTIFY_OK:
+                                __skb_unlink(this, list);
+                                iucv_sock_wake_msglim(sk);
+                                kfree_skb(this);
+                                break;
+                        case TX_NOTIFY_PENDING:
+                                atomic_inc(&iucv->pendings);
+                                break;
+                        case TX_NOTIFY_DELAYED_OK:
+                                __skb_unlink(this, list);
+                                atomic_dec(&iucv->pendings);
+                                if (atomic_read(&iucv->pendings) <= 0)
+                                        iucv_sock_wake_msglim(sk);
+                                kfree_skb(this);
+                                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(this, list);
+                                kfree_skb(this);
+                                if (!list_empty(&iucv->accept_q))
+                                        sk->sk_state = IUCV_SEVERED;
+                                else
+                                        sk->sk_state = IUCV_DISCONN;
+                                sk->sk_state_change(sk);
+                                break;
+                        }
+                        break;
+                }
+                list_skb = list_skb->next;
+        }
+        spin_unlock_irqrestore(&list->lock, flags);
+
+out_unlock:
+        bh_unlock_sock(sk);
+}
 static const struct proto_ops iucv_sock_ops = {
         .family         = PF_IUCV,
         .owner          = THIS_MODULE,
@@ -1724,7 +2320,12 @@ static const struct net_proto_family iucv_sock_family_ops = {
         .create = iucv_sock_create,
 };
 
-static int __init afiucv_iucv_init(void)
+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;
 
@@ -1763,24 +2364,22 @@ static int __init afiucv_init(void)
 {
         int err;
 
-        if (!MACHINE_IS_VM) {
-                pr_err("The af_iucv module cannot be loaded"
-                       " without z/VM\n");
-                err = -EPROTONOSUPPORT;
-                goto out;
-        }
-        cpcmd("QUERY USERID", iucv_userid, sizeof(iucv_userid), &err);
-        if (unlikely(err)) {
-                WARN_ON(err);
-                err = -EPROTONOSUPPORT;
-                goto out;
-        }
+        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");
-                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);
@@ -1790,10 +2389,12 @@ static int __init afiucv_init(void)
         if (err)
                 goto out_proto;
 
-        err = afiucv_iucv_init();
-        if (err)
-                goto out_sock;
-
+        if (pr_iucv) {
+                err = afiucv_iucv_init();
+                if (err)
+                        goto out_sock;
+        }
+        dev_add_pack(&iucv_packet_type);
         return 0;
 
 out_sock:
@@ -1808,10 +2409,13 @@ out:
 
 static void __exit afiucv_exit(void)
 {
-        device_unregister(af_iucv_dev);
-        driver_unregister(&af_iucv_driver);
-        pr_iucv->iucv_unregister(&af_iucv_handler, 0);
-        symbol_put(iucv_if);
+        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);
+        }
+        dev_remove_pack(&iucv_packet_type);
         sock_unregister(PF_IUCV);
         proto_unregister(&iucv_proto);
 }
@@ -1824,3 +2428,4 @@ MODULE_DESCRIPTION("IUCV Sockets ver " VERSION);
 MODULE_VERSION(VERSION);
 MODULE_LICENSE("GPL");
 MODULE_ALIAS_NETPROTO(PF_IUCV);
+