net/iucv/af_iucv.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  *  IUCV protocol stack for Linux on zSeries
   4  *
   5  *  Copyright IBM Corp. 2006, 2009
   6  *
   7  *  Author(s):  Jennifer Hunt <jenhunt@us.ibm.com>
   8  *              Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
   9  *  PM functions:
  10  *              Ursula Braun <ursula.braun@de.ibm.com>
  11  */
  12
  13 #define KMSG_COMPONENT "af_iucv"
  14 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
  15
  16 #include <linux/module.h>
  17 #include <linux/netdevice.h>
  18 #include <linux/types.h>
  19 #include <linux/limits.h>
  20 #include <linux/list.h>
  21 #include <linux/errno.h>
  22 #include <linux/kernel.h>
  23 #include <linux/sched/signal.h>
  24 #include <linux/slab.h>
  25 #include <linux/skbuff.h>
  26 #include <linux/init.h>
  27 #include <linux/poll.h>
  28 #include <linux/security.h>
  29 #include <net/sock.h>
  30 #include <asm/ebcdic.h>
  31 #include <asm/cpcmd.h>
  32 #include <linux/kmod.h>
  33
  34 #include <net/iucv/af_iucv.h>
  35
  36 #define VERSION "1.2"
  37
  38 static char iucv_userid[80];
  39
  40 static struct proto iucv_proto = {
  41         .name           = "AF_IUCV",
  42         .owner          = THIS_MODULE,
  43         .obj_size       = sizeof(struct iucv_sock),
  44 };
  45
  46 static struct iucv_interface *pr_iucv;
  47
  48 /* special AF_IUCV IPRM messages */
  49 static const u8 iprm_shutdown[8] =
  50         {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01};
  51
  52 #define TRGCLS_SIZE     sizeof_field(struct iucv_message, class)
  53
  54 #define __iucv_sock_wait(sk, condition, timeo, ret)                     \
  55 do {                                                                    \
  56         DEFINE_WAIT(__wait);                                            \
  57         long __timeo = timeo;                                           \
  58         ret = 0;                                                        \
  59         prepare_to_wait(sk_sleep(sk), &__wait, TASK_INTERRUPTIBLE);     \
  60         while (!(condition)) {                                          \
  61                 if (!__timeo) {                                         \
  62                         ret = -EAGAIN;                                  \
  63                         break;                                          \
  64                 }                                                       \
  65                 if (signal_pending(current)) {                          \
  66                         ret = sock_intr_errno(__timeo);                 \
  67                         break;                                          \
  68                 }                                                       \
  69                 release_sock(sk);                                       \
  70                 __timeo = schedule_timeout(__timeo);                    \
  71                 lock_sock(sk);                                          \
  72                 ret = sock_error(sk);                                   \
  73                 if (ret)                                                \
  74                         break;                                          \
  75         }                                                               \
  76         finish_wait(sk_sleep(sk), &__wait);                             \
  77 } while (0)
  78
  79 #define iucv_sock_wait(sk, condition, timeo)                            \
  80 ({                                                                      \
  81         int __ret = 0;                                                  \
  82         if (!(condition))                                               \
  83                 __iucv_sock_wait(sk, condition, timeo, __ret);          \
  84         __ret;                                                          \
  85 })
  86
  87 static struct sock *iucv_accept_dequeue(struct sock *parent,
  88                                         struct socket *newsock);
  89 static void iucv_sock_kill(struct sock *sk);
  90 static void iucv_sock_close(struct sock *sk);
  91
  92 static void afiucv_hs_callback_txnotify(struct sock *sk, enum iucv_tx_notify);
  93
  94 /* Call Back functions */
  95 static void iucv_callback_rx(struct iucv_path *, struct iucv_message *);
  96 static void iucv_callback_txdone(struct iucv_path *, struct iucv_message *);
  97 static void iucv_callback_connack(struct iucv_path *, u8 *);
  98 static int iucv_callback_connreq(struct iucv_path *, u8 *, u8 *);
  99 static void iucv_callback_connrej(struct iucv_path *, u8 *);
 100 static void iucv_callback_shutdown(struct iucv_path *, u8 *);
 101
 102 static struct iucv_sock_list iucv_sk_list = {
 103         .lock = __RW_LOCK_UNLOCKED(iucv_sk_list.lock),
 104         .autobind_name = ATOMIC_INIT(0)
 105 };
 106
 107 static struct iucv_handler af_iucv_handler = {
 108         .path_pending     = iucv_callback_connreq,
 109         .path_complete    = iucv_callback_connack,
 110         .path_severed     = iucv_callback_connrej,
 111         .message_pending  = iucv_callback_rx,
 112         .message_complete = iucv_callback_txdone,
 113         .path_quiesced    = iucv_callback_shutdown,
 114 };
 115
 116 static inline void high_nmcpy(unsigned char *dst, char *src)
 117 {
 118        memcpy(dst, src, 8);
 119 }
 120
 121 static inline void low_nmcpy(unsigned char *dst, char *src)
 122 {
 123        memcpy(&dst[8], src, 8);
 124 }
 125
 126 /**
 127  * iucv_msg_length() - Returns the length of an iucv message.
 128  * @msg:        Pointer to struct iucv_message, MUST NOT be NULL
 129  *
 130  * The function returns the length of the specified iucv message @msg of data
 131  * stored in a buffer and of data stored in the parameter list (PRMDATA).
 132  *
 133  * For IUCV_IPRMDATA, AF_IUCV uses the following convention to transport socket
 134  * data:
 135  *      PRMDATA[0..6]   socket data (max 7 bytes);
 136  *      PRMDATA[7]      socket data length value (len is 0xff - PRMDATA[7])
 137  *
 138  * The socket data length is computed by subtracting the socket data length
 139  * value from 0xFF.
 140  * If the socket data len is greater 7, then PRMDATA can be used for special
 141  * notifications (see iucv_sock_shutdown); and further,
 142  * if the socket data len is > 7, the function returns 8.
 143  *
 144  * Use this function to allocate socket buffers to store iucv message data.
 145  */
 146 static inline size_t iucv_msg_length(struct iucv_message *msg)
 147 {
 148         size_t datalen;
 149
 150         if (msg->flags & IUCV_IPRMDATA) {
 151                 datalen = 0xff - msg->rmmsg[7];
 152                 return (datalen < 8) ? datalen : 8;
 153         }
 154         return msg->length;
 155 }
 156
 157 /**
 158  * iucv_sock_in_state() - check for specific states
 159  * @sk:         sock structure
 160  * @state:      first iucv sk state
 161  * @state:      second iucv sk state
 162  *
 163  * Returns true if the socket in either in the first or second state.
 164  */
 165 static int iucv_sock_in_state(struct sock *sk, int state, int state2)
 166 {
 167         return (sk->sk_state == state || sk->sk_state == state2);
 168 }
 169
 170 /**
 171  * iucv_below_msglim() - function to check if messages can be sent
 172  * @sk:         sock structure
 173  *
 174  * Returns true if the send queue length is lower than the message limit.
 175  * Always returns true if the socket is not connected (no iucv path for
 176  * checking the message limit).
 177  */
 178 static inline int iucv_below_msglim(struct sock *sk)
 179 {
 180         struct iucv_sock *iucv = iucv_sk(sk);
 181
 182         if (sk->sk_state != IUCV_CONNECTED)
 183                 return 1;
 184         if (iucv->transport == AF_IUCV_TRANS_IUCV)
 185                 return (atomic_read(&iucv->skbs_in_xmit) < iucv->path->msglim);
 186         else
 187                 return ((atomic_read(&iucv->msg_sent) < iucv->msglimit_peer) &&
 188                         (atomic_read(&iucv->pendings) <= 0));
 189 }
 190
 191 /**
 192  * iucv_sock_wake_msglim() - Wake up thread waiting on msg limit
 193  */
 194 static void iucv_sock_wake_msglim(struct sock *sk)
 195 {
 196         struct socket_wq *wq;
 197
 198         rcu_read_lock();
 199         wq = rcu_dereference(sk->sk_wq);
 200         if (skwq_has_sleeper(wq))
 201                 wake_up_interruptible_all(&wq->wait);
 202         sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
 203         rcu_read_unlock();
 204 }
 205
 206 /**
 207  * afiucv_hs_send() - send a message through HiperSockets transport
 208  */
 209 static int afiucv_hs_send(struct iucv_message *imsg, struct sock *sock,
 210                    struct sk_buff *skb, u8 flags)
 211 {
 212         struct iucv_sock *iucv = iucv_sk(sock);
 213         struct af_iucv_trans_hdr *phs_hdr;
 214         int err, confirm_recv = 0;
 215
 216         phs_hdr = skb_push(skb, sizeof(*phs_hdr));
 217         memset(phs_hdr, 0, sizeof(*phs_hdr));
 218         skb_reset_network_header(skb);
 219
 220         phs_hdr->magic = ETH_P_AF_IUCV;
 221         phs_hdr->version = 1;
 222         phs_hdr->flags = flags;
 223         if (flags == AF_IUCV_FLAG_SYN)
 224                 phs_hdr->window = iucv->msglimit;
 225         else if ((flags == AF_IUCV_FLAG_WIN) || !flags) {
 226                 confirm_recv = atomic_read(&iucv->msg_recv);
 227                 phs_hdr->window = confirm_recv;
 228                 if (confirm_recv)
 229                         phs_hdr->flags = phs_hdr->flags | AF_IUCV_FLAG_WIN;
 230         }
 231         memcpy(phs_hdr->destUserID, iucv->dst_user_id, 8);
 232         memcpy(phs_hdr->destAppName, iucv->dst_name, 8);
 233         memcpy(phs_hdr->srcUserID, iucv->src_user_id, 8);
 234         memcpy(phs_hdr->srcAppName, iucv->src_name, 8);
 235         ASCEBC(phs_hdr->destUserID, sizeof(phs_hdr->destUserID));
 236         ASCEBC(phs_hdr->destAppName, sizeof(phs_hdr->destAppName));
 237         ASCEBC(phs_hdr->srcUserID, sizeof(phs_hdr->srcUserID));
 238         ASCEBC(phs_hdr->srcAppName, sizeof(phs_hdr->srcAppName));
 239         if (imsg)
 240                 memcpy(&phs_hdr->iucv_hdr, imsg, sizeof(struct iucv_message));
 241
 242         skb->dev = iucv->hs_dev;
 243         if (!skb->dev) {
 244                 err = -ENODEV;
 245                 goto err_free;
 246         }
 247
 248         dev_hard_header(skb, skb->dev, ETH_P_AF_IUCV, NULL, NULL, skb->len);
 249
 250         if (!(skb->dev->flags & IFF_UP) || !netif_carrier_ok(skb->dev)) {
 251                 err = -ENETDOWN;
 252                 goto err_free;
 253         }
 254         if (skb->len > skb->dev->mtu) {
 255                 if (sock->sk_type == SOCK_SEQPACKET) {
 256                         err = -EMSGSIZE;
 257                         goto err_free;
 258                 }
 259                 err = pskb_trim(skb, skb->dev->mtu);
 260                 if (err)
 261                         goto err_free;
 262         }
 263         skb->protocol = cpu_to_be16(ETH_P_AF_IUCV);
 264
 265         atomic_inc(&iucv->skbs_in_xmit);
 266         err = dev_queue_xmit(skb);
 267         if (net_xmit_eval(err)) {
 268                 atomic_dec(&iucv->skbs_in_xmit);
 269         } else {
 270                 atomic_sub(confirm_recv, &iucv->msg_recv);
 271                 WARN_ON(atomic_read(&iucv->msg_recv) < 0);
 272         }
 273         return net_xmit_eval(err);
 274
 275 err_free:
 276         kfree_skb(skb);
 277         return err;
 278 }
 279
 280 static struct sock *__iucv_get_sock_by_name(char *nm)
 281 {
 282         struct sock *sk;
 283
 284         sk_for_each(sk, &iucv_sk_list.head)
 285                 if (!memcmp(&iucv_sk(sk)->src_name, nm, 8))
 286                         return sk;
 287
 288         return NULL;
 289 }
 290
 291 static void iucv_sock_destruct(struct sock *sk)
 292 {
 293         skb_queue_purge(&sk->sk_receive_queue);
 294         skb_queue_purge(&sk->sk_error_queue);
 295
 296         sk_mem_reclaim(sk);
 297
 298         if (!sock_flag(sk, SOCK_DEAD)) {
 299                 pr_err("Attempt to release alive iucv socket %p\n", sk);
 300                 return;
 301         }
 302
 303         WARN_ON(atomic_read(&sk->sk_rmem_alloc));
 304         WARN_ON(refcount_read(&sk->sk_wmem_alloc));
 305         WARN_ON(sk->sk_wmem_queued);
 306         WARN_ON(sk->sk_forward_alloc);
 307 }
 308
 309 /* Cleanup Listen */
 310 static void iucv_sock_cleanup_listen(struct sock *parent)
 311 {
 312         struct sock *sk;
 313
 314         /* Close non-accepted connections */
 315         while ((sk = iucv_accept_dequeue(parent, NULL))) {
 316                 iucv_sock_close(sk);
 317                 iucv_sock_kill(sk);
 318         }
 319
 320         parent->sk_state = IUCV_CLOSED;
 321 }
 322
 323 static void iucv_sock_link(struct iucv_sock_list *l, struct sock *sk)
 324 {
 325         write_lock_bh(&l->lock);
 326         sk_add_node(sk, &l->head);
 327         write_unlock_bh(&l->lock);
 328 }
 329
 330 static void iucv_sock_unlink(struct iucv_sock_list *l, struct sock *sk)
 331 {
 332         write_lock_bh(&l->lock);
 333         sk_del_node_init(sk);
 334         write_unlock_bh(&l->lock);
 335 }
 336
 337 /* Kill socket (only if zapped and orphaned) */
 338 static void iucv_sock_kill(struct sock *sk)
 339 {
 340         if (!sock_flag(sk, SOCK_ZAPPED) || sk->sk_socket)
 341                 return;
 342
 343         iucv_sock_unlink(&iucv_sk_list, sk);
 344         sock_set_flag(sk, SOCK_DEAD);
 345         sock_put(sk);
 346 }
 347
 348 /* Terminate an IUCV path */
 349 static void iucv_sever_path(struct sock *sk, int with_user_data)
 350 {
 351         unsigned char user_data[16];
 352         struct iucv_sock *iucv = iucv_sk(sk);
 353         struct iucv_path *path = iucv->path;
 354
 355         if (iucv->path) {
 356                 iucv->path = NULL;
 357                 if (with_user_data) {
 358                         low_nmcpy(user_data, iucv->src_name);
 359                         high_nmcpy(user_data, iucv->dst_name);
 360                         ASCEBC(user_data, sizeof(user_data));
 361                         pr_iucv->path_sever(path, user_data);
 362                 } else
 363                         pr_iucv->path_sever(path, NULL);
 364                 iucv_path_free(path);
 365         }
 366 }
 367
 368 /* Send controlling flags through an IUCV socket for HIPER transport */
 369 static int iucv_send_ctrl(struct sock *sk, u8 flags)
 370 {
 371         struct iucv_sock *iucv = iucv_sk(sk);
 372         int err = 0;
 373         int blen;
 374         struct sk_buff *skb;
 375         u8 shutdown = 0;
 376
 377         blen = sizeof(struct af_iucv_trans_hdr) +
 378                LL_RESERVED_SPACE(iucv->hs_dev);
 379         if (sk->sk_shutdown & SEND_SHUTDOWN) {
 380                 /* controlling flags should be sent anyway */
 381                 shutdown = sk->sk_shutdown;
 382                 sk->sk_shutdown &= RCV_SHUTDOWN;
 383         }
 384         skb = sock_alloc_send_skb(sk, blen, 1, &err);
 385         if (skb) {
 386                 skb_reserve(skb, blen);
 387                 err = afiucv_hs_send(NULL, sk, skb, flags);
 388         }
 389         if (shutdown)
 390                 sk->sk_shutdown = shutdown;
 391         return err;
 392 }
 393
 394 /* Close an IUCV socket */
 395 static void iucv_sock_close(struct sock *sk)
 396 {
 397         struct iucv_sock *iucv = iucv_sk(sk);
 398         unsigned long timeo;
 399         int err = 0;
 400
 401         lock_sock(sk);
 402
 403         switch (sk->sk_state) {
 404         case IUCV_LISTEN:
 405                 iucv_sock_cleanup_listen(sk);
 406                 break;
 407
 408         case IUCV_CONNECTED:
 409                 if (iucv->transport == AF_IUCV_TRANS_HIPER) {
 410                         err = iucv_send_ctrl(sk, AF_IUCV_FLAG_FIN);
 411                         sk->sk_state = IUCV_DISCONN;
 412                         sk->sk_state_change(sk);
 413                 }
 414                 fallthrough;
 415
 416         case IUCV_DISCONN:
 417                 sk->sk_state = IUCV_CLOSING;
 418                 sk->sk_state_change(sk);
 419
 420                 if (!err && atomic_read(&iucv->skbs_in_xmit) > 0) {
 421                         if (sock_flag(sk, SOCK_LINGER) && sk->sk_lingertime)
 422                                 timeo = sk->sk_lingertime;
 423                         else
 424                                 timeo = IUCV_DISCONN_TIMEOUT;
 425                         iucv_sock_wait(sk,
 426                                         iucv_sock_in_state(sk, IUCV_CLOSED, 0),
 427                                         timeo);
 428                 }
 429                 fallthrough;
 430
 431         case IUCV_CLOSING:
 432                 sk->sk_state = IUCV_CLOSED;
 433                 sk->sk_state_change(sk);
 434
 435                 sk->sk_err = ECONNRESET;
 436                 sk->sk_state_change(sk);
 437
 438                 skb_queue_purge(&iucv->send_skb_q);
 439                 skb_queue_purge(&iucv->backlog_skb_q);
 440                 fallthrough;
 441
 442         default:
 443                 iucv_sever_path(sk, 1);
 444         }
 445
 446         if (iucv->hs_dev) {
 447                 dev_put(iucv->hs_dev);
 448                 iucv->hs_dev = NULL;
 449                 sk->sk_bound_dev_if = 0;
 450         }
 451
 452         /* mark socket for deletion by iucv_sock_kill() */
 453         sock_set_flag(sk, SOCK_ZAPPED);
 454
 455         release_sock(sk);
 456 }
 457
 458 static void iucv_sock_init(struct sock *sk, struct sock *parent)
 459 {
 460         if (parent) {
 461                 sk->sk_type = parent->sk_type;
 462                 security_sk_clone(parent, sk);
 463         }
 464 }
 465
 466 static struct sock *iucv_sock_alloc(struct socket *sock, int proto, gfp_t prio, int kern)
 467 {
 468         struct sock *sk;
 469         struct iucv_sock *iucv;
 470
 471         sk = sk_alloc(&init_net, PF_IUCV, prio, &iucv_proto, kern);
 472         if (!sk)
 473                 return NULL;
 474         iucv = iucv_sk(sk);
 475
 476         sock_init_data(sock, sk);
 477         INIT_LIST_HEAD(&iucv->accept_q);
 478         spin_lock_init(&iucv->accept_q_lock);
 479         skb_queue_head_init(&iucv->send_skb_q);
 480         INIT_LIST_HEAD(&iucv->message_q.list);
 481         spin_lock_init(&iucv->message_q.lock);
 482         skb_queue_head_init(&iucv->backlog_skb_q);
 483         iucv->send_tag = 0;
 484         atomic_set(&iucv->pendings, 0);
 485         iucv->flags = 0;
 486         iucv->msglimit = 0;
 487         atomic_set(&iucv->skbs_in_xmit, 0);
 488         atomic_set(&iucv->msg_sent, 0);
 489         atomic_set(&iucv->msg_recv, 0);
 490         iucv->path = NULL;
 491         iucv->sk_txnotify = afiucv_hs_callback_txnotify;
 492         memset(&iucv->src_user_id , 0, 32);
 493         if (pr_iucv)
 494                 iucv->transport = AF_IUCV_TRANS_IUCV;
 495         else
 496                 iucv->transport = AF_IUCV_TRANS_HIPER;
 497
 498         sk->sk_destruct = iucv_sock_destruct;
 499         sk->sk_sndtimeo = IUCV_CONN_TIMEOUT;
 500
 501         sock_reset_flag(sk, SOCK_ZAPPED);
 502
 503         sk->sk_protocol = proto;
 504         sk->sk_state    = IUCV_OPEN;
 505
 506         iucv_sock_link(&iucv_sk_list, sk);
 507         return sk;
 508 }
 509
 510 static void iucv_accept_enqueue(struct sock *parent, struct sock *sk)
 511 {
 512         unsigned long flags;
 513         struct iucv_sock *par = iucv_sk(parent);
 514
 515         sock_hold(sk);
 516         spin_lock_irqsave(&par->accept_q_lock, flags);
 517         list_add_tail(&iucv_sk(sk)->accept_q, &par->accept_q);
 518         spin_unlock_irqrestore(&par->accept_q_lock, flags);
 519         iucv_sk(sk)->parent = parent;
 520         sk_acceptq_added(parent);
 521 }
 522
 523 static void iucv_accept_unlink(struct sock *sk)
 524 {
 525         unsigned long flags;
 526         struct iucv_sock *par = iucv_sk(iucv_sk(sk)->parent);
 527
 528         spin_lock_irqsave(&par->accept_q_lock, flags);
 529         list_del_init(&iucv_sk(sk)->accept_q);
 530         spin_unlock_irqrestore(&par->accept_q_lock, flags);
 531         sk_acceptq_removed(iucv_sk(sk)->parent);
 532         iucv_sk(sk)->parent = NULL;
 533         sock_put(sk);
 534 }
 535
 536 static struct sock *iucv_accept_dequeue(struct sock *parent,
 537                                         struct socket *newsock)
 538 {
 539         struct iucv_sock *isk, *n;
 540         struct sock *sk;
 541
 542         list_for_each_entry_safe(isk, n, &iucv_sk(parent)->accept_q, accept_q) {
 543                 sk = (struct sock *) isk;
 544                 lock_sock(sk);
 545
 546                 if (sk->sk_state == IUCV_CLOSED) {
 547                         iucv_accept_unlink(sk);
 548                         release_sock(sk);
 549                         continue;
 550                 }
 551
 552                 if (sk->sk_state == IUCV_CONNECTED ||
 553                     sk->sk_state == IUCV_DISCONN ||
 554                     !newsock) {
 555                         iucv_accept_unlink(sk);
 556                         if (newsock)
 557                                 sock_graft(sk, newsock);
 558
 559                         release_sock(sk);
 560                         return sk;
 561                 }
 562
 563                 release_sock(sk);
 564         }
 565         return NULL;
 566 }
 567
 568 static void __iucv_auto_name(struct iucv_sock *iucv)
 569 {
 570         char name[12];
 571
 572         sprintf(name, "%08x", atomic_inc_return(&iucv_sk_list.autobind_name));
 573         while (__iucv_get_sock_by_name(name)) {
 574                 sprintf(name, "%08x",
 575                         atomic_inc_return(&iucv_sk_list.autobind_name));
 576         }
 577         memcpy(iucv->src_name, name, 8);
 578 }
 579
 580 /* Bind an unbound socket */
 581 static int iucv_sock_bind(struct socket *sock, struct sockaddr *addr,
 582                           int addr_len)
 583 {
 584         DECLARE_SOCKADDR(struct sockaddr_iucv *, sa, addr);
 585         char uid[sizeof(sa->siucv_user_id)];
 586         struct sock *sk = sock->sk;
 587         struct iucv_sock *iucv;
 588         int err = 0;
 589         struct net_device *dev;
 590
 591         /* Verify the input sockaddr */
 592         if (addr_len < sizeof(struct sockaddr_iucv) ||
 593             addr->sa_family != AF_IUCV)
 594                 return -EINVAL;
 595
 596         lock_sock(sk);
 597         if (sk->sk_state != IUCV_OPEN) {
 598                 err = -EBADFD;
 599                 goto done;
 600         }
 601
 602         write_lock_bh(&iucv_sk_list.lock);
 603
 604         iucv = iucv_sk(sk);
 605         if (__iucv_get_sock_by_name(sa->siucv_name)) {
 606                 err = -EADDRINUSE;
 607                 goto done_unlock;
 608         }
 609         if (iucv->path)
 610                 goto done_unlock;
 611
 612         /* Bind the socket */
 613         if (pr_iucv)
 614                 if (!memcmp(sa->siucv_user_id, iucv_userid, 8))
 615                         goto vm_bind; /* VM IUCV transport */
 616
 617         /* try hiper transport */
 618         memcpy(uid, sa->siucv_user_id, sizeof(uid));
 619         ASCEBC(uid, 8);
 620         rcu_read_lock();
 621         for_each_netdev_rcu(&init_net, dev) {
 622                 if (!memcmp(dev->perm_addr, uid, 8)) {
 623                         memcpy(iucv->src_user_id, sa->siucv_user_id, 8);
 624                         /* Check for unitialized siucv_name */
 625                         if (strncmp(sa->siucv_name, "        ", 8) == 0)
 626                                 __iucv_auto_name(iucv);
 627                         else
 628                                 memcpy(iucv->src_name, sa->siucv_name, 8);
 629                         sk->sk_bound_dev_if = dev->ifindex;
 630                         iucv->hs_dev = dev;
 631                         dev_hold(dev);
 632                         sk->sk_state = IUCV_BOUND;
 633                         iucv->transport = AF_IUCV_TRANS_HIPER;
 634                         if (!iucv->msglimit)
 635                                 iucv->msglimit = IUCV_HIPER_MSGLIM_DEFAULT;
 636                         rcu_read_unlock();
 637                         goto done_unlock;
 638                 }
 639         }
 640         rcu_read_unlock();
 641 vm_bind:
 642         if (pr_iucv) {
 643                 /* use local userid for backward compat */
 644                 memcpy(iucv->src_name, sa->siucv_name, 8);
 645                 memcpy(iucv->src_user_id, iucv_userid, 8);
 646                 sk->sk_state = IUCV_BOUND;
 647                 iucv->transport = AF_IUCV_TRANS_IUCV;
 648                 sk->sk_allocation |= GFP_DMA;
 649                 if (!iucv->msglimit)
 650                         iucv->msglimit = IUCV_QUEUELEN_DEFAULT;
 651                 goto done_unlock;
 652         }
 653         /* found no dev to bind */
 654         err = -ENODEV;
 655 done_unlock:
 656         /* Release the socket list lock */
 657         write_unlock_bh(&iucv_sk_list.lock);
 658 done:
 659         release_sock(sk);
 660         return err;
 661 }
 662
 663 /* Automatically bind an unbound socket */
 664 static int iucv_sock_autobind(struct sock *sk)
 665 {
 666         struct iucv_sock *iucv = iucv_sk(sk);
 667         int err = 0;
 668
 669         if (unlikely(!pr_iucv))
 670                 return -EPROTO;
 671
 672         memcpy(iucv->src_user_id, iucv_userid, 8);
 673         iucv->transport = AF_IUCV_TRANS_IUCV;
 674         sk->sk_allocation |= GFP_DMA;
 675
 676         write_lock_bh(&iucv_sk_list.lock);
 677         __iucv_auto_name(iucv);
 678         write_unlock_bh(&iucv_sk_list.lock);
 679
 680         if (!iucv->msglimit)
 681                 iucv->msglimit = IUCV_QUEUELEN_DEFAULT;
 682
 683         return err;
 684 }
 685
 686 static int afiucv_path_connect(struct socket *sock, struct sockaddr *addr)
 687 {
 688         DECLARE_SOCKADDR(struct sockaddr_iucv *, sa, addr);
 689         struct sock *sk = sock->sk;
 690         struct iucv_sock *iucv = iucv_sk(sk);
 691         unsigned char user_data[16];
 692         int err;
 693
 694         high_nmcpy(user_data, sa->siucv_name);
 695         low_nmcpy(user_data, iucv->src_name);
 696         ASCEBC(user_data, sizeof(user_data));
 697
 698         /* Create path. */
 699         iucv->path = iucv_path_alloc(iucv->msglimit,
 700                                      IUCV_IPRMDATA, GFP_KERNEL);
 701         if (!iucv->path) {
 702                 err = -ENOMEM;
 703                 goto done;
 704         }
 705         err = pr_iucv->path_connect(iucv->path, &af_iucv_handler,
 706                                     sa->siucv_user_id, NULL, user_data,
 707                                     sk);
 708         if (err) {
 709                 iucv_path_free(iucv->path);
 710                 iucv->path = NULL;
 711                 switch (err) {
 712                 case 0x0b:      /* Target communicator is not logged on */
 713                         err = -ENETUNREACH;
 714                         break;
 715                 case 0x0d:      /* Max connections for this guest exceeded */
 716                 case 0x0e:      /* Max connections for target guest exceeded */
 717                         err = -EAGAIN;
 718                         break;
 719                 case 0x0f:      /* Missing IUCV authorization */
 720                         err = -EACCES;
 721                         break;
 722                 default:
 723                         err = -ECONNREFUSED;
 724                         break;
 725                 }
 726         }
 727 done:
 728         return err;
 729 }
 730
 731 /* Connect an unconnected socket */
 732 static int iucv_sock_connect(struct socket *sock, struct sockaddr *addr,
 733                              int alen, int flags)
 734 {
 735         DECLARE_SOCKADDR(struct sockaddr_iucv *, sa, addr);
 736         struct sock *sk = sock->sk;
 737         struct iucv_sock *iucv = iucv_sk(sk);
 738         int err;
 739
 740         if (alen < sizeof(struct sockaddr_iucv) || addr->sa_family != AF_IUCV)
 741                 return -EINVAL;
 742
 743         if (sk->sk_state != IUCV_OPEN && sk->sk_state != IUCV_BOUND)
 744                 return -EBADFD;
 745
 746         if (sk->sk_state == IUCV_OPEN &&
 747             iucv->transport == AF_IUCV_TRANS_HIPER)
 748                 return -EBADFD; /* explicit bind required */
 749
 750         if (sk->sk_type != SOCK_STREAM && sk->sk_type != SOCK_SEQPACKET)
 751                 return -EINVAL;
 752
 753         if (sk->sk_state == IUCV_OPEN) {
 754                 err = iucv_sock_autobind(sk);
 755                 if (unlikely(err))
 756                         return err;
 757         }
 758
 759         lock_sock(sk);
 760
 761         /* Set the destination information */
 762         memcpy(iucv->dst_user_id, sa->siucv_user_id, 8);
 763         memcpy(iucv->dst_name, sa->siucv_name, 8);
 764
 765         if (iucv->transport == AF_IUCV_TRANS_HIPER)
 766                 err = iucv_send_ctrl(sock->sk, AF_IUCV_FLAG_SYN);
 767         else
 768                 err = afiucv_path_connect(sock, addr);
 769         if (err)
 770                 goto done;
 771
 772         if (sk->sk_state != IUCV_CONNECTED)
 773                 err = iucv_sock_wait(sk, iucv_sock_in_state(sk, IUCV_CONNECTED,
 774                                                             IUCV_DISCONN),
 775                                      sock_sndtimeo(sk, flags & O_NONBLOCK));
 776
 777         if (sk->sk_state == IUCV_DISCONN || sk->sk_state == IUCV_CLOSED)
 778                 err = -ECONNREFUSED;
 779
 780         if (err && iucv->transport == AF_IUCV_TRANS_IUCV)
 781                 iucv_sever_path(sk, 0);
 782
 783 done:
 784         release_sock(sk);
 785         return err;
 786 }
 787
 788 /* Move a socket into listening state. */
 789 static int iucv_sock_listen(struct socket *sock, int backlog)
 790 {
 791         struct sock *sk = sock->sk;
 792         int err;
 793
 794         lock_sock(sk);
 795
 796         err = -EINVAL;
 797         if (sk->sk_state != IUCV_BOUND)
 798                 goto done;
 799
 800         if (sock->type != SOCK_STREAM && sock->type != SOCK_SEQPACKET)
 801                 goto done;
 802
 803         sk->sk_max_ack_backlog = backlog;
 804         sk->sk_ack_backlog = 0;
 805         sk->sk_state = IUCV_LISTEN;
 806         err = 0;
 807
 808 done:
 809         release_sock(sk);
 810         return err;
 811 }
 812
 813 /* Accept a pending connection */
 814 static int iucv_sock_accept(struct socket *sock, struct socket *newsock,
 815                             int flags, bool kern)
 816 {
 817         DECLARE_WAITQUEUE(wait, current);
 818         struct sock *sk = sock->sk, *nsk;
 819         long timeo;
 820         int err = 0;
 821
 822         lock_sock_nested(sk, SINGLE_DEPTH_NESTING);
 823
 824         if (sk->sk_state != IUCV_LISTEN) {
 825                 err = -EBADFD;
 826                 goto done;
 827         }
 828
 829         timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);
 830
 831         /* Wait for an incoming connection */
 832         add_wait_queue_exclusive(sk_sleep(sk), &wait);
 833         while (!(nsk = iucv_accept_dequeue(sk, newsock))) {
 834                 set_current_state(TASK_INTERRUPTIBLE);
 835                 if (!timeo) {
 836                         err = -EAGAIN;
 837                         break;
 838                 }
 839
 840                 release_sock(sk);
 841                 timeo = schedule_timeout(timeo);
 842                 lock_sock_nested(sk, SINGLE_DEPTH_NESTING);
 843
 844                 if (sk->sk_state != IUCV_LISTEN) {
 845                         err = -EBADFD;
 846                         break;
 847                 }
 848
 849                 if (signal_pending(current)) {
 850                         err = sock_intr_errno(timeo);
 851                         break;
 852                 }
 853         }
 854
 855         set_current_state(TASK_RUNNING);
 856         remove_wait_queue(sk_sleep(sk), &wait);
 857
 858         if (err)
 859                 goto done;
 860
 861         newsock->state = SS_CONNECTED;
 862
 863 done:
 864         release_sock(sk);
 865         return err;
 866 }
 867
 868 static int iucv_sock_getname(struct socket *sock, struct sockaddr *addr,
 869                              int peer)
 870 {
 871         DECLARE_SOCKADDR(struct sockaddr_iucv *, siucv, addr);
 872         struct sock *sk = sock->sk;
 873         struct iucv_sock *iucv = iucv_sk(sk);
 874
 875         addr->sa_family = AF_IUCV;
 876
 877         if (peer) {
 878                 memcpy(siucv->siucv_user_id, iucv->dst_user_id, 8);
 879                 memcpy(siucv->siucv_name, iucv->dst_name, 8);
 880         } else {
 881                 memcpy(siucv->siucv_user_id, iucv->src_user_id, 8);
 882                 memcpy(siucv->siucv_name, iucv->src_name, 8);
 883         }
 884         memset(&siucv->siucv_port, 0, sizeof(siucv->siucv_port));
 885         memset(&siucv->siucv_addr, 0, sizeof(siucv->siucv_addr));
 886         memset(&siucv->siucv_nodeid, 0, sizeof(siucv->siucv_nodeid));
 887
 888         return sizeof(struct sockaddr_iucv);
 889 }
 890
 891 /**
 892  * iucv_send_iprm() - Send socket data in parameter list of an iucv message.
 893  * @path:       IUCV path
 894  * @msg:        Pointer to a struct iucv_message
 895  * @skb:        The socket data to send, skb->len MUST BE <= 7
 896  *
 897  * Send the socket data in the parameter list in the iucv message
 898  * (IUCV_IPRMDATA). The socket data is stored at index 0 to 6 in the parameter
 899  * list and the socket data len at index 7 (last byte).
 900  * See also iucv_msg_length().
 901  *
 902  * Returns the error code from the iucv_message_send() call.
 903  */
 904 static int iucv_send_iprm(struct iucv_path *path, struct iucv_message *msg,
 905                           struct sk_buff *skb)
 906 {
 907         u8 prmdata[8];
 908
 909         memcpy(prmdata, (void *) skb->data, skb->len);
 910         prmdata[7] = 0xff - (u8) skb->len;
 911         return pr_iucv->message_send(path, msg, IUCV_IPRMDATA, 0,
 912                                  (void *) prmdata, 8);
 913 }
 914
 915 static int iucv_sock_sendmsg(struct socket *sock, struct msghdr *msg,
 916                              size_t len)
 917 {
 918         struct sock *sk = sock->sk;
 919         struct iucv_sock *iucv = iucv_sk(sk);
 920         size_t headroom = 0;
 921         size_t linear;
 922         struct sk_buff *skb;
 923         struct iucv_message txmsg = {0};
 924         struct cmsghdr *cmsg;
 925         int cmsg_done;
 926         long timeo;
 927         char user_id[9];
 928         char appl_id[9];
 929         int err;
 930         int noblock = msg->msg_flags & MSG_DONTWAIT;
 931
 932         err = sock_error(sk);
 933         if (err)
 934                 return err;
 935
 936         if (msg->msg_flags & MSG_OOB)
 937                 return -EOPNOTSUPP;
 938
 939         /* SOCK_SEQPACKET: we do not support segmented records */
 940         if (sk->sk_type == SOCK_SEQPACKET && !(msg->msg_flags & MSG_EOR))
 941                 return -EOPNOTSUPP;
 942
 943         lock_sock(sk);
 944
 945         if (sk->sk_shutdown & SEND_SHUTDOWN) {
 946                 err = -EPIPE;
 947                 goto out;
 948         }
 949
 950         /* Return if the socket is not in connected state */
 951         if (sk->sk_state != IUCV_CONNECTED) {
 952                 err = -ENOTCONN;
 953                 goto out;
 954         }
 955
 956         /* initialize defaults */
 957         cmsg_done   = 0;        /* check for duplicate headers */
 958
 959         /* iterate over control messages */
 960         for_each_cmsghdr(cmsg, msg) {
 961                 if (!CMSG_OK(msg, cmsg)) {
 962                         err = -EINVAL;
 963                         goto out;
 964                 }
 965
 966                 if (cmsg->cmsg_level != SOL_IUCV)
 967                         continue;
 968
 969                 if (cmsg->cmsg_type & cmsg_done) {
 970                         err = -EINVAL;
 971                         goto out;
 972                 }
 973                 cmsg_done |= cmsg->cmsg_type;
 974
 975                 switch (cmsg->cmsg_type) {
 976                 case SCM_IUCV_TRGCLS:
 977                         if (cmsg->cmsg_len != CMSG_LEN(TRGCLS_SIZE)) {
 978                                 err = -EINVAL;
 979                                 goto out;
 980                         }
 981
 982                         /* set iucv message target class */
 983                         memcpy(&txmsg.class,
 984                                 (void *) CMSG_DATA(cmsg), TRGCLS_SIZE);
 985
 986                         break;
 987
 988                 default:
 989                         err = -EINVAL;
 990                         goto out;
 991                 }
 992         }
 993
 994         /* allocate one skb for each iucv message:
 995          * this is fine for SOCK_SEQPACKET (unless we want to support
 996          * segmented records using the MSG_EOR flag), but
 997          * for SOCK_STREAM we might want to improve it in future */
 998         if (iucv->transport == AF_IUCV_TRANS_HIPER) {
 999                 headroom = sizeof(struct af_iucv_trans_hdr) +
1000                            LL_RESERVED_SPACE(iucv->hs_dev);
1001                 linear = min(len, PAGE_SIZE - headroom);
1002         } else {
1003                 if (len < PAGE_SIZE) {
1004                         linear = len;
1005                 } else {
1006                         /* In nonlinear "classic" iucv skb,
1007                          * reserve space for iucv_array
1008                          */
1009                         headroom = sizeof(struct iucv_array) *
1010                                    (MAX_SKB_FRAGS + 1);
1011                         linear = PAGE_SIZE - headroom;
1012                 }
1013         }
1014         skb = sock_alloc_send_pskb(sk, headroom + linear, len - linear,
1015                                    noblock, &err, 0);
1016         if (!skb)
1017                 goto out;
1018         if (headroom)
1019                 skb_reserve(skb, headroom);
1020         skb_put(skb, linear);
1021         skb->len = len;
1022         skb->data_len = len - linear;
1023         err = skb_copy_datagram_from_iter(skb, 0, &msg->msg_iter, len);
1024         if (err)
1025                 goto fail;
1026
1027         /* wait if outstanding messages for iucv path has reached */
1028         timeo = sock_sndtimeo(sk, noblock);
1029         err = iucv_sock_wait(sk, iucv_below_msglim(sk), timeo);
1030         if (err)
1031                 goto fail;
1032
1033         /* return -ECONNRESET if the socket is no longer connected */
1034         if (sk->sk_state != IUCV_CONNECTED) {
1035                 err = -ECONNRESET;
1036                 goto fail;
1037         }
1038
1039         /* increment and save iucv message tag for msg_completion cbk */
1040         txmsg.tag = iucv->send_tag++;
1041         IUCV_SKB_CB(skb)->tag = txmsg.tag;
1042
1043         if (iucv->transport == AF_IUCV_TRANS_HIPER) {
1044                 atomic_inc(&iucv->msg_sent);
1045                 err = afiucv_hs_send(&txmsg, sk, skb, 0);
1046                 if (err) {
1047                         atomic_dec(&iucv->msg_sent);
1048                         goto out;
1049                 }
1050         } else { /* Classic VM IUCV transport */
1051                 skb_queue_tail(&iucv->send_skb_q, skb);
1052                 atomic_inc(&iucv->skbs_in_xmit);
1053
1054                 if (((iucv->path->flags & IUCV_IPRMDATA) & iucv->flags) &&
1055                     skb->len <= 7) {
1056                         err = iucv_send_iprm(iucv->path, &txmsg, skb);
1057
1058                         /* on success: there is no message_complete callback */
1059                         /* for an IPRMDATA msg; remove skb from send queue   */
1060                         if (err == 0) {
1061                                 atomic_dec(&iucv->skbs_in_xmit);
1062                                 skb_unlink(skb, &iucv->send_skb_q);
1063                                 kfree_skb(skb);
1064                         }
1065
1066                         /* this error should never happen since the     */
1067                         /* IUCV_IPRMDATA path flag is set... sever path */
1068                         if (err == 0x15) {
1069                                 pr_iucv->path_sever(iucv->path, NULL);
1070                                 atomic_dec(&iucv->skbs_in_xmit);
1071                                 skb_unlink(skb, &iucv->send_skb_q);
1072                                 err = -EPIPE;
1073                                 goto fail;
1074                         }
1075                 } else if (skb_is_nonlinear(skb)) {
1076                         struct iucv_array *iba = (struct iucv_array *)skb->head;
1077                         int i;
1078
1079                         /* skip iucv_array lying in the headroom */
1080                         iba[0].address = (u32)(addr_t)skb->data;
1081                         iba[0].length = (u32)skb_headlen(skb);
1082                         for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
1083                                 skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
1084
1085                                 iba[i + 1].address =
1086                                         (u32)(addr_t)skb_frag_address(frag);
1087                                 iba[i + 1].length = (u32)skb_frag_size(frag);
1088                         }
1089                         err = pr_iucv->message_send(iucv->path, &txmsg,
1090                                                     IUCV_IPBUFLST, 0,
1091                                                     (void *)iba, skb->len);
1092                 } else { /* non-IPRM Linear skb */
1093                         err = pr_iucv->message_send(iucv->path, &txmsg,
1094                                         0, 0, (void *)skb->data, skb->len);
1095                 }
1096                 if (err) {
1097                         if (err == 3) {
1098                                 user_id[8] = 0;
1099                                 memcpy(user_id, iucv->dst_user_id, 8);
1100                                 appl_id[8] = 0;
1101                                 memcpy(appl_id, iucv->dst_name, 8);
1102                                 pr_err(
1103                 "Application %s on z/VM guest %s exceeds message limit\n",
1104                                         appl_id, user_id);
1105                                 err = -EAGAIN;
1106                         } else {
1107                                 err = -EPIPE;
1108                         }
1109
1110                         atomic_dec(&iucv->skbs_in_xmit);
1111                         skb_unlink(skb, &iucv->send_skb_q);
1112                         goto fail;
1113                 }
1114         }
1115
1116         release_sock(sk);
1117         return len;
1118
1119 fail:
1120         kfree_skb(skb);
1121 out:
1122         release_sock(sk);
1123         return err;
1124 }
1125
1126 static struct sk_buff *alloc_iucv_recv_skb(unsigned long len)
1127 {
1128         size_t headroom, linear;
1129         struct sk_buff *skb;
1130         int err;
1131
1132         if (len < PAGE_SIZE) {
1133                 headroom = 0;
1134                 linear = len;
1135         } else {
1136                 headroom = sizeof(struct iucv_array) * (MAX_SKB_FRAGS + 1);
1137                 linear = PAGE_SIZE - headroom;
1138         }
1139         skb = alloc_skb_with_frags(headroom + linear, len - linear,
1140                                    0, &err, GFP_ATOMIC | GFP_DMA);
1141         WARN_ONCE(!skb,
1142                   "alloc of recv iucv skb len=%lu failed with errcode=%d\n",
1143                   len, err);
1144         if (skb) {
1145                 if (headroom)
1146                         skb_reserve(skb, headroom);
1147                 skb_put(skb, linear);
1148                 skb->len = len;
1149                 skb->data_len = len - linear;
1150         }
1151         return skb;
1152 }
1153
1154 /* iucv_process_message() - Receive a single outstanding IUCV message
1155  *
1156  * Locking: must be called with message_q.lock held
1157  */
1158 static void iucv_process_message(struct sock *sk, struct sk_buff *skb,
1159                                  struct iucv_path *path,
1160                                  struct iucv_message *msg)
1161 {
1162         int rc;
1163         unsigned int len;
1164
1165         len = iucv_msg_length(msg);
1166
1167         /* store msg target class in the second 4 bytes of skb ctrl buffer */
1168         /* Note: the first 4 bytes are reserved for msg tag */
1169         IUCV_SKB_CB(skb)->class = msg->class;
1170
1171         /* check for special IPRM messages (e.g. iucv_sock_shutdown) */
1172         if ((msg->flags & IUCV_IPRMDATA) && len > 7) {
1173                 if (memcmp(msg->rmmsg, iprm_shutdown, 8) == 0) {
1174                         skb->data = NULL;
1175                         skb->len = 0;
1176                 }
1177         } else {
1178                 if (skb_is_nonlinear(skb)) {
1179                         struct iucv_array *iba = (struct iucv_array *)skb->head;
1180                         int i;
1181
1182                         iba[0].address = (u32)(addr_t)skb->data;
1183                         iba[0].length = (u32)skb_headlen(skb);
1184                         for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
1185                                 skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
1186
1187                                 iba[i + 1].address =
1188                                         (u32)(addr_t)skb_frag_address(frag);
1189                                 iba[i + 1].length = (u32)skb_frag_size(frag);
1190                         }
1191                         rc = pr_iucv->message_receive(path, msg,
1192                                               IUCV_IPBUFLST,
1193                                               (void *)iba, len, NULL);
1194                 } else {
1195                         rc = pr_iucv->message_receive(path, msg,
1196                                               msg->flags & IUCV_IPRMDATA,
1197                                               skb->data, len, NULL);
1198                 }
1199                 if (rc) {
1200                         kfree_skb(skb);
1201                         return;
1202                 }
1203                 WARN_ON_ONCE(skb->len != len);
1204         }
1205
1206         IUCV_SKB_CB(skb)->offset = 0;
1207         if (sk_filter(sk, skb)) {
1208                 atomic_inc(&sk->sk_drops);      /* skb rejected by filter */
1209                 kfree_skb(skb);
1210                 return;
1211         }
1212         if (__sock_queue_rcv_skb(sk, skb))      /* handle rcv queue full */
1213                 skb_queue_tail(&iucv_sk(sk)->backlog_skb_q, skb);
1214 }
1215
1216 /* iucv_process_message_q() - Process outstanding IUCV messages
1217  *
1218  * Locking: must be called with message_q.lock held
1219  */
1220 static void iucv_process_message_q(struct sock *sk)
1221 {
1222         struct iucv_sock *iucv = iucv_sk(sk);
1223         struct sk_buff *skb;
1224         struct sock_msg_q *p, *n;
1225
1226         list_for_each_entry_safe(p, n, &iucv->message_q.list, list) {
1227                 skb = alloc_iucv_recv_skb(iucv_msg_length(&p->msg));
1228                 if (!skb)
1229                         break;
1230                 iucv_process_message(sk, skb, p->path, &p->msg);
1231                 list_del(&p->list);
1232                 kfree(p);
1233                 if (!skb_queue_empty(&iucv->backlog_skb_q))
1234                         break;
1235         }
1236 }
1237
1238 static int iucv_sock_recvmsg(struct socket *sock, struct msghdr *msg,
1239                              size_t len, int flags)
1240 {
1241         int noblock = flags & MSG_DONTWAIT;
1242         struct sock *sk = sock->sk;
1243         struct iucv_sock *iucv = iucv_sk(sk);
1244         unsigned int copied, rlen;
1245         struct sk_buff *skb, *rskb, *cskb;
1246         int err = 0;
1247         u32 offset;
1248
1249         if ((sk->sk_state == IUCV_DISCONN) &&
1250             skb_queue_empty(&iucv->backlog_skb_q) &&
1251             skb_queue_empty(&sk->sk_receive_queue) &&
1252             list_empty(&iucv->message_q.list))
1253                 return 0;
1254
1255         if (flags & (MSG_OOB))
1256                 return -EOPNOTSUPP;
1257
1258         /* receive/dequeue next skb:
1259          * the function understands MSG_PEEK and, thus, does not dequeue skb */
1260         skb = skb_recv_datagram(sk, flags, noblock, &err);
1261         if (!skb) {
1262                 if (sk->sk_shutdown & RCV_SHUTDOWN)
1263                         return 0;
1264                 return err;
1265         }
1266
1267         offset = IUCV_SKB_CB(skb)->offset;
1268         rlen   = skb->len - offset;             /* real length of skb */
1269         copied = min_t(unsigned int, rlen, len);
1270         if (!rlen)
1271                 sk->sk_shutdown = sk->sk_shutdown | RCV_SHUTDOWN;
1272
1273         cskb = skb;
1274         if (skb_copy_datagram_msg(cskb, offset, msg, copied)) {
1275                 if (!(flags & MSG_PEEK))
1276                         skb_queue_head(&sk->sk_receive_queue, skb);
1277                 return -EFAULT;
1278         }
1279
1280         /* SOCK_SEQPACKET: set MSG_TRUNC if recv buf size is too small */
1281         if (sk->sk_type == SOCK_SEQPACKET) {
1282                 if (copied < rlen)
1283                         msg->msg_flags |= MSG_TRUNC;
1284                 /* each iucv message contains a complete record */
1285                 msg->msg_flags |= MSG_EOR;
1286         }
1287
1288         /* create control message to store iucv msg target class:
1289          * get the trgcls from the control buffer of the skb due to
1290          * fragmentation of original iucv message. */
1291         err = put_cmsg(msg, SOL_IUCV, SCM_IUCV_TRGCLS,
1292                        sizeof(IUCV_SKB_CB(skb)->class),
1293                        (void *)&IUCV_SKB_CB(skb)->class);
1294         if (err) {
1295                 if (!(flags & MSG_PEEK))
1296                         skb_queue_head(&sk->sk_receive_queue, skb);
1297                 return err;
1298         }
1299
1300         /* Mark read part of skb as used */
1301         if (!(flags & MSG_PEEK)) {
1302
1303                 /* SOCK_STREAM: re-queue skb if it contains unreceived data */
1304                 if (sk->sk_type == SOCK_STREAM) {
1305                         if (copied < rlen) {
1306                                 IUCV_SKB_CB(skb)->offset = offset + copied;
1307                                 skb_queue_head(&sk->sk_receive_queue, skb);
1308                                 goto done;
1309                         }
1310                 }
1311
1312                 kfree_skb(skb);
1313                 if (iucv->transport == AF_IUCV_TRANS_HIPER) {
1314                         atomic_inc(&iucv->msg_recv);
1315                         if (atomic_read(&iucv->msg_recv) > iucv->msglimit) {
1316                                 WARN_ON(1);
1317                                 iucv_sock_close(sk);
1318                                 return -EFAULT;
1319                         }
1320                 }
1321
1322                 /* Queue backlog skbs */
1323                 spin_lock_bh(&iucv->message_q.lock);
1324                 rskb = skb_dequeue(&iucv->backlog_skb_q);
1325                 while (rskb) {
1326                         IUCV_SKB_CB(rskb)->offset = 0;
1327                         if (__sock_queue_rcv_skb(sk, rskb)) {
1328                                 /* handle rcv queue full */
1329                                 skb_queue_head(&iucv->backlog_skb_q,
1330                                                 rskb);
1331                                 break;
1332                         }
1333                         rskb = skb_dequeue(&iucv->backlog_skb_q);
1334                 }
1335                 if (skb_queue_empty(&iucv->backlog_skb_q)) {
1336                         if (!list_empty(&iucv->message_q.list))
1337                                 iucv_process_message_q(sk);
1338                         if (atomic_read(&iucv->msg_recv) >=
1339                                                         iucv->msglimit / 2) {
1340                                 err = iucv_send_ctrl(sk, AF_IUCV_FLAG_WIN);
1341                                 if (err) {
1342                                         sk->sk_state = IUCV_DISCONN;
1343                                         sk->sk_state_change(sk);
1344                                 }
1345                         }
1346                 }
1347                 spin_unlock_bh(&iucv->message_q.lock);
1348         }
1349
1350 done:
1351         /* SOCK_SEQPACKET: return real length if MSG_TRUNC is set */
1352         if (sk->sk_type == SOCK_SEQPACKET && (flags & MSG_TRUNC))
1353                 copied = rlen;
1354
1355         return copied;
1356 }
1357
1358 static inline __poll_t iucv_accept_poll(struct sock *parent)
1359 {
1360         struct iucv_sock *isk, *n;
1361         struct sock *sk;
1362
1363         list_for_each_entry_safe(isk, n, &iucv_sk(parent)->accept_q, accept_q) {
1364                 sk = (struct sock *) isk;
1365
1366                 if (sk->sk_state == IUCV_CONNECTED)
1367                         return EPOLLIN | EPOLLRDNORM;
1368         }
1369
1370         return 0;
1371 }
1372
1373 static __poll_t iucv_sock_poll(struct file *file, struct socket *sock,
1374                                poll_table *wait)
1375 {
1376         struct sock *sk = sock->sk;
1377         __poll_t mask = 0;
1378
1379         sock_poll_wait(file, sock, wait);
1380
1381         if (sk->sk_state == IUCV_LISTEN)
1382                 return iucv_accept_poll(sk);
1383
1384         if (sk->sk_err || !skb_queue_empty(&sk->sk_error_queue))
1385                 mask |= EPOLLERR |
1386                         (sock_flag(sk, SOCK_SELECT_ERR_QUEUE) ? EPOLLPRI : 0);
1387
1388         if (sk->sk_shutdown & RCV_SHUTDOWN)
1389                 mask |= EPOLLRDHUP;
1390
1391         if (sk->sk_shutdown == SHUTDOWN_MASK)
1392                 mask |= EPOLLHUP;
1393
1394         if (!skb_queue_empty(&sk->sk_receive_queue) ||
1395             (sk->sk_shutdown & RCV_SHUTDOWN))
1396                 mask |= EPOLLIN | EPOLLRDNORM;
1397
1398         if (sk->sk_state == IUCV_CLOSED)
1399                 mask |= EPOLLHUP;
1400
1401         if (sk->sk_state == IUCV_DISCONN)
1402                 mask |= EPOLLIN;
1403
1404         if (sock_writeable(sk) && iucv_below_msglim(sk))
1405                 mask |= EPOLLOUT | EPOLLWRNORM | EPOLLWRBAND;
1406         else
1407                 sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
1408
1409         return mask;
1410 }
1411
1412 static int iucv_sock_shutdown(struct socket *sock, int how)
1413 {
1414         struct sock *sk = sock->sk;
1415         struct iucv_sock *iucv = iucv_sk(sk);
1416         struct iucv_message txmsg;
1417         int err = 0;
1418
1419         how++;
1420
1421         if ((how & ~SHUTDOWN_MASK) || !how)
1422                 return -EINVAL;
1423
1424         lock_sock(sk);
1425         switch (sk->sk_state) {
1426         case IUCV_LISTEN:
1427         case IUCV_DISCONN:
1428         case IUCV_CLOSING:
1429         case IUCV_CLOSED:
1430                 err = -ENOTCONN;
1431                 goto fail;
1432         default:
1433                 break;
1434         }
1435
1436         if ((how == SEND_SHUTDOWN || how == SHUTDOWN_MASK) &&
1437             sk->sk_state == IUCV_CONNECTED) {
1438                 if (iucv->transport == AF_IUCV_TRANS_IUCV) {
1439                         txmsg.class = 0;
1440                         txmsg.tag = 0;
1441                         err = pr_iucv->message_send(iucv->path, &txmsg,
1442                                 IUCV_IPRMDATA, 0, (void *) iprm_shutdown, 8);
1443                         if (err) {
1444                                 switch (err) {
1445                                 case 1:
1446                                         err = -ENOTCONN;
1447                                         break;
1448                                 case 2:
1449                                         err = -ECONNRESET;
1450                                         break;
1451                                 default:
1452                                         err = -ENOTCONN;
1453                                         break;
1454                                 }
1455                         }
1456                 } else
1457                         iucv_send_ctrl(sk, AF_IUCV_FLAG_SHT);
1458         }
1459
1460         sk->sk_shutdown |= how;
1461         if (how == RCV_SHUTDOWN || how == SHUTDOWN_MASK) {
1462                 if ((iucv->transport == AF_IUCV_TRANS_IUCV) &&
1463                     iucv->path) {
1464                         err = pr_iucv->path_quiesce(iucv->path, NULL);
1465                         if (err)
1466                                 err = -ENOTCONN;
1467 /*                      skb_queue_purge(&sk->sk_receive_queue); */
1468                 }
1469                 skb_queue_purge(&sk->sk_receive_queue);
1470         }
1471
1472         /* Wake up anyone sleeping in poll */
1473         sk->sk_state_change(sk);
1474
1475 fail:
1476         release_sock(sk);
1477         return err;
1478 }
1479
1480 static int iucv_sock_release(struct socket *sock)
1481 {
1482         struct sock *sk = sock->sk;
1483         int err = 0;
1484
1485         if (!sk)
1486                 return 0;
1487
1488         iucv_sock_close(sk);
1489
1490         sock_orphan(sk);
1491         iucv_sock_kill(sk);
1492         return err;
1493 }
1494
1495 /* getsockopt and setsockopt */
1496 static int iucv_sock_setsockopt(struct socket *sock, int level, int optname,
1497                                 sockptr_t optval, unsigned int optlen)
1498 {
1499         struct sock *sk = sock->sk;
1500         struct iucv_sock *iucv = iucv_sk(sk);
1501         int val;
1502         int rc;
1503
1504         if (level != SOL_IUCV)
1505                 return -ENOPROTOOPT;
1506
1507         if (optlen < sizeof(int))
1508                 return -EINVAL;
1509
1510         if (copy_from_sockptr(&val, optval, sizeof(int)))
1511                 return -EFAULT;
1512
1513         rc = 0;
1514
1515         lock_sock(sk);
1516         switch (optname) {
1517         case SO_IPRMDATA_MSG:
1518                 if (val)
1519                         iucv->flags |= IUCV_IPRMDATA;
1520                 else
1521                         iucv->flags &= ~IUCV_IPRMDATA;
1522                 break;
1523         case SO_MSGLIMIT:
1524                 switch (sk->sk_state) {
1525                 case IUCV_OPEN:
1526                 case IUCV_BOUND:
1527                         if (val < 1 || val > U16_MAX)
1528                                 rc = -EINVAL;
1529                         else
1530                                 iucv->msglimit = val;
1531                         break;
1532                 default:
1533                         rc = -EINVAL;
1534                         break;
1535                 }
1536                 break;
1537         default:
1538                 rc = -ENOPROTOOPT;
1539                 break;
1540         }
1541         release_sock(sk);
1542
1543         return rc;
1544 }
1545
1546 static int iucv_sock_getsockopt(struct socket *sock, int level, int optname,
1547                                 char __user *optval, int __user *optlen)
1548 {
1549         struct sock *sk = sock->sk;
1550         struct iucv_sock *iucv = iucv_sk(sk);
1551         unsigned int val;
1552         int len;
1553
1554         if (level != SOL_IUCV)
1555                 return -ENOPROTOOPT;
1556
1557         if (get_user(len, optlen))
1558                 return -EFAULT;
1559
1560         if (len < 0)
1561                 return -EINVAL;
1562
1563         len = min_t(unsigned int, len, sizeof(int));
1564
1565         switch (optname) {
1566         case SO_IPRMDATA_MSG:
1567                 val = (iucv->flags & IUCV_IPRMDATA) ? 1 : 0;
1568                 break;
1569         case SO_MSGLIMIT:
1570                 lock_sock(sk);
1571                 val = (iucv->path != NULL) ? iucv->path->msglim /* connected */
1572                                            : iucv->msglimit;    /* default */
1573                 release_sock(sk);
1574                 break;
1575         case SO_MSGSIZE:
1576                 if (sk->sk_state == IUCV_OPEN)
1577                         return -EBADFD;
1578                 val = (iucv->hs_dev) ? iucv->hs_dev->mtu -
1579                                 sizeof(struct af_iucv_trans_hdr) - ETH_HLEN :
1580                                 0x7fffffff;
1581                 break;
1582         default:
1583                 return -ENOPROTOOPT;
1584         }
1585
1586         if (put_user(len, optlen))
1587                 return -EFAULT;
1588         if (copy_to_user(optval, &val, len))
1589                 return -EFAULT;
1590
1591         return 0;
1592 }
1593
1594
1595 /* Callback wrappers - called from iucv base support */
1596 static int iucv_callback_connreq(struct iucv_path *path,
1597                                  u8 ipvmid[8], u8 ipuser[16])
1598 {
1599         unsigned char user_data[16];
1600         unsigned char nuser_data[16];
1601         unsigned char src_name[8];
1602         struct sock *sk, *nsk;
1603         struct iucv_sock *iucv, *niucv;
1604         int err;
1605
1606         memcpy(src_name, ipuser, 8);
1607         EBCASC(src_name, 8);
1608         /* Find out if this path belongs to af_iucv. */
1609         read_lock(&iucv_sk_list.lock);
1610         iucv = NULL;
1611         sk = NULL;
1612         sk_for_each(sk, &iucv_sk_list.head)
1613                 if (sk->sk_state == IUCV_LISTEN &&
1614                     !memcmp(&iucv_sk(sk)->src_name, src_name, 8)) {
1615                         /*
1616                          * Found a listening socket with
1617                          * src_name == ipuser[0-7].
1618                          */
1619                         iucv = iucv_sk(sk);
1620                         break;
1621                 }
1622         read_unlock(&iucv_sk_list.lock);
1623         if (!iucv)
1624                 /* No socket found, not one of our paths. */
1625                 return -EINVAL;
1626
1627         bh_lock_sock(sk);
1628
1629         /* Check if parent socket is listening */
1630         low_nmcpy(user_data, iucv->src_name);
1631         high_nmcpy(user_data, iucv->dst_name);
1632         ASCEBC(user_data, sizeof(user_data));
1633         if (sk->sk_state != IUCV_LISTEN) {
1634                 err = pr_iucv->path_sever(path, user_data);
1635                 iucv_path_free(path);
1636                 goto fail;
1637         }
1638
1639         /* Check for backlog size */
1640         if (sk_acceptq_is_full(sk)) {
1641                 err = pr_iucv->path_sever(path, user_data);
1642                 iucv_path_free(path);
1643                 goto fail;
1644         }
1645
1646         /* Create the new socket */
1647         nsk = iucv_sock_alloc(NULL, sk->sk_protocol, GFP_ATOMIC, 0);
1648         if (!nsk) {
1649                 err = pr_iucv->path_sever(path, user_data);
1650                 iucv_path_free(path);
1651                 goto fail;
1652         }
1653
1654         niucv = iucv_sk(nsk);
1655         iucv_sock_init(nsk, sk);
1656         niucv->transport = AF_IUCV_TRANS_IUCV;
1657         nsk->sk_allocation |= GFP_DMA;
1658
1659         /* Set the new iucv_sock */
1660         memcpy(niucv->dst_name, ipuser + 8, 8);
1661         EBCASC(niucv->dst_name, 8);
1662         memcpy(niucv->dst_user_id, ipvmid, 8);
1663         memcpy(niucv->src_name, iucv->src_name, 8);
1664         memcpy(niucv->src_user_id, iucv->src_user_id, 8);
1665         niucv->path = path;
1666
1667         /* Call iucv_accept */
1668         high_nmcpy(nuser_data, ipuser + 8);
1669         memcpy(nuser_data + 8, niucv->src_name, 8);
1670         ASCEBC(nuser_data + 8, 8);
1671
1672         /* set message limit for path based on msglimit of accepting socket */
1673         niucv->msglimit = iucv->msglimit;
1674         path->msglim = iucv->msglimit;
1675         err = pr_iucv->path_accept(path, &af_iucv_handler, nuser_data, nsk);
1676         if (err) {
1677                 iucv_sever_path(nsk, 1);
1678                 iucv_sock_kill(nsk);
1679                 goto fail;
1680         }
1681
1682         iucv_accept_enqueue(sk, nsk);
1683
1684         /* Wake up accept */
1685         nsk->sk_state = IUCV_CONNECTED;
1686         sk->sk_data_ready(sk);
1687         err = 0;
1688 fail:
1689         bh_unlock_sock(sk);
1690         return 0;
1691 }
1692
1693 static void iucv_callback_connack(struct iucv_path *path, u8 ipuser[16])
1694 {
1695         struct sock *sk = path->private;
1696
1697         sk->sk_state = IUCV_CONNECTED;
1698         sk->sk_state_change(sk);
1699 }
1700
1701 static void iucv_callback_rx(struct iucv_path *path, struct iucv_message *msg)
1702 {
1703         struct sock *sk = path->private;
1704         struct iucv_sock *iucv = iucv_sk(sk);
1705         struct sk_buff *skb;
1706         struct sock_msg_q *save_msg;
1707         int len;
1708
1709         if (sk->sk_shutdown & RCV_SHUTDOWN) {
1710                 pr_iucv->message_reject(path, msg);
1711                 return;
1712         }
1713
1714         spin_lock(&iucv->message_q.lock);
1715
1716         if (!list_empty(&iucv->message_q.list) ||
1717             !skb_queue_empty(&iucv->backlog_skb_q))
1718                 goto save_message;
1719
1720         len = atomic_read(&sk->sk_rmem_alloc);
1721         len += SKB_TRUESIZE(iucv_msg_length(msg));
1722         if (len > sk->sk_rcvbuf)
1723                 goto save_message;
1724
1725         skb = alloc_iucv_recv_skb(iucv_msg_length(msg));
1726         if (!skb)
1727                 goto save_message;
1728
1729         iucv_process_message(sk, skb, path, msg);
1730         goto out_unlock;
1731
1732 save_message:
1733         save_msg = kzalloc(sizeof(struct sock_msg_q), GFP_ATOMIC | GFP_DMA);
1734         if (!save_msg)
1735                 goto out_unlock;
1736         save_msg->path = path;
1737         save_msg->msg = *msg;
1738
1739         list_add_tail(&save_msg->list, &iucv->message_q.list);
1740
1741 out_unlock:
1742         spin_unlock(&iucv->message_q.lock);
1743 }
1744
1745 static void iucv_callback_txdone(struct iucv_path *path,
1746                                  struct iucv_message *msg)
1747 {
1748         struct sock *sk = path->private;
1749         struct sk_buff *this = NULL;
1750         struct sk_buff_head *list;
1751         struct sk_buff *list_skb;
1752         struct iucv_sock *iucv;
1753         unsigned long flags;
1754
1755         iucv = iucv_sk(sk);
1756         list = &iucv->send_skb_q;
1757
1758         bh_lock_sock(sk);
1759
1760         spin_lock_irqsave(&list->lock, flags);
1761         skb_queue_walk(list, list_skb) {
1762                 if (msg->tag == IUCV_SKB_CB(list_skb)->tag) {
1763                         this = list_skb;
1764                         break;
1765                 }
1766         }
1767         if (this) {
1768                 atomic_dec(&iucv->skbs_in_xmit);
1769                 __skb_unlink(this, list);
1770         }
1771
1772         spin_unlock_irqrestore(&list->lock, flags);
1773
1774         if (this) {
1775                 kfree_skb(this);
1776                 /* wake up any process waiting for sending */
1777                 iucv_sock_wake_msglim(sk);
1778         }
1779
1780         if (sk->sk_state == IUCV_CLOSING) {
1781                 if (atomic_read(&iucv->skbs_in_xmit) == 0) {
1782                         sk->sk_state = IUCV_CLOSED;
1783                         sk->sk_state_change(sk);
1784                 }
1785         }
1786         bh_unlock_sock(sk);
1787
1788 }
1789
1790 static void iucv_callback_connrej(struct iucv_path *path, u8 ipuser[16])
1791 {
1792         struct sock *sk = path->private;
1793
1794         if (sk->sk_state == IUCV_CLOSED)
1795                 return;
1796
1797         bh_lock_sock(sk);
1798         iucv_sever_path(sk, 1);
1799         sk->sk_state = IUCV_DISCONN;
1800
1801         sk->sk_state_change(sk);
1802         bh_unlock_sock(sk);
1803 }
1804
1805 /* called if the other communication side shuts down its RECV direction;
1806  * in turn, the callback sets SEND_SHUTDOWN to disable sending of data.
1807  */
1808 static void iucv_callback_shutdown(struct iucv_path *path, u8 ipuser[16])
1809 {
1810         struct sock *sk = path->private;
1811
1812         bh_lock_sock(sk);
1813         if (sk->sk_state != IUCV_CLOSED) {
1814                 sk->sk_shutdown |= SEND_SHUTDOWN;
1815                 sk->sk_state_change(sk);
1816         }
1817         bh_unlock_sock(sk);
1818 }
1819
1820 /***************** HiperSockets transport callbacks ********************/
1821 static void afiucv_swap_src_dest(struct sk_buff *skb)
1822 {
1823         struct af_iucv_trans_hdr *trans_hdr = iucv_trans_hdr(skb);
1824         char tmpID[8];
1825         char tmpName[8];
1826
1827         ASCEBC(trans_hdr->destUserID, sizeof(trans_hdr->destUserID));
1828         ASCEBC(trans_hdr->destAppName, sizeof(trans_hdr->destAppName));
1829         ASCEBC(trans_hdr->srcUserID, sizeof(trans_hdr->srcUserID));
1830         ASCEBC(trans_hdr->srcAppName, sizeof(trans_hdr->srcAppName));
1831         memcpy(tmpID, trans_hdr->srcUserID, 8);
1832         memcpy(tmpName, trans_hdr->srcAppName, 8);
1833         memcpy(trans_hdr->srcUserID, trans_hdr->destUserID, 8);
1834         memcpy(trans_hdr->srcAppName, trans_hdr->destAppName, 8);
1835         memcpy(trans_hdr->destUserID, tmpID, 8);
1836         memcpy(trans_hdr->destAppName, tmpName, 8);
1837         skb_push(skb, ETH_HLEN);
1838         memset(skb->data, 0, ETH_HLEN);
1839 }
1840
1841 /**
1842  * afiucv_hs_callback_syn - react on received SYN
1843  **/
1844 static int afiucv_hs_callback_syn(struct sock *sk, struct sk_buff *skb)
1845 {
1846         struct af_iucv_trans_hdr *trans_hdr = iucv_trans_hdr(skb);
1847         struct sock *nsk;
1848         struct iucv_sock *iucv, *niucv;
1849         int err;
1850
1851         iucv = iucv_sk(sk);
1852         if (!iucv) {
1853                 /* no sock - connection refused */
1854                 afiucv_swap_src_dest(skb);
1855                 trans_hdr->flags = AF_IUCV_FLAG_SYN | AF_IUCV_FLAG_FIN;
1856                 err = dev_queue_xmit(skb);
1857                 goto out;
1858         }
1859
1860         nsk = iucv_sock_alloc(NULL, sk->sk_protocol, GFP_ATOMIC, 0);
1861         bh_lock_sock(sk);
1862         if ((sk->sk_state != IUCV_LISTEN) ||
1863             sk_acceptq_is_full(sk) ||
1864             !nsk) {
1865                 /* error on server socket - connection refused */
1866                 afiucv_swap_src_dest(skb);
1867                 trans_hdr->flags = AF_IUCV_FLAG_SYN | AF_IUCV_FLAG_FIN;
1868                 err = dev_queue_xmit(skb);
1869                 iucv_sock_kill(nsk);
1870                 bh_unlock_sock(sk);
1871                 goto out;
1872         }
1873
1874         niucv = iucv_sk(nsk);
1875         iucv_sock_init(nsk, sk);
1876         niucv->transport = AF_IUCV_TRANS_HIPER;
1877         niucv->msglimit = iucv->msglimit;
1878         if (!trans_hdr->window)
1879                 niucv->msglimit_peer = IUCV_HIPER_MSGLIM_DEFAULT;
1880         else
1881                 niucv->msglimit_peer = trans_hdr->window;
1882         memcpy(niucv->dst_name, trans_hdr->srcAppName, 8);
1883         memcpy(niucv->dst_user_id, trans_hdr->srcUserID, 8);
1884         memcpy(niucv->src_name, iucv->src_name, 8);
1885         memcpy(niucv->src_user_id, iucv->src_user_id, 8);
1886         nsk->sk_bound_dev_if = sk->sk_bound_dev_if;
1887         niucv->hs_dev = iucv->hs_dev;
1888         dev_hold(niucv->hs_dev);
1889         afiucv_swap_src_dest(skb);
1890         trans_hdr->flags = AF_IUCV_FLAG_SYN | AF_IUCV_FLAG_ACK;
1891         trans_hdr->window = niucv->msglimit;
1892         /* if receiver acks the xmit connection is established */
1893         err = dev_queue_xmit(skb);
1894         if (!err) {
1895                 iucv_accept_enqueue(sk, nsk);
1896                 nsk->sk_state = IUCV_CONNECTED;
1897                 sk->sk_data_ready(sk);
1898         } else
1899                 iucv_sock_kill(nsk);
1900         bh_unlock_sock(sk);
1901
1902 out:
1903         return NET_RX_SUCCESS;
1904 }
1905
1906 /**
1907  * afiucv_hs_callback_synack() - react on received SYN-ACK
1908  **/
1909 static int afiucv_hs_callback_synack(struct sock *sk, struct sk_buff *skb)
1910 {
1911         struct iucv_sock *iucv = iucv_sk(sk);
1912
1913         if (!iucv)
1914                 goto out;
1915         if (sk->sk_state != IUCV_BOUND)
1916                 goto out;
1917         bh_lock_sock(sk);
1918         iucv->msglimit_peer = iucv_trans_hdr(skb)->window;
1919         sk->sk_state = IUCV_CONNECTED;
1920         sk->sk_state_change(sk);
1921         bh_unlock_sock(sk);
1922 out:
1923         kfree_skb(skb);
1924         return NET_RX_SUCCESS;
1925 }
1926
1927 /**
1928  * afiucv_hs_callback_synfin() - react on received SYN_FIN
1929  **/
1930 static int afiucv_hs_callback_synfin(struct sock *sk, struct sk_buff *skb)
1931 {
1932         struct iucv_sock *iucv = iucv_sk(sk);
1933
1934         if (!iucv)
1935                 goto out;
1936         if (sk->sk_state != IUCV_BOUND)
1937                 goto out;
1938         bh_lock_sock(sk);
1939         sk->sk_state = IUCV_DISCONN;
1940         sk->sk_state_change(sk);
1941         bh_unlock_sock(sk);
1942 out:
1943         kfree_skb(skb);
1944         return NET_RX_SUCCESS;
1945 }
1946
1947 /**
1948  * afiucv_hs_callback_fin() - react on received FIN
1949  **/
1950 static int afiucv_hs_callback_fin(struct sock *sk, struct sk_buff *skb)
1951 {
1952         struct iucv_sock *iucv = iucv_sk(sk);
1953
1954         /* other end of connection closed */
1955         if (!iucv)
1956                 goto out;
1957         bh_lock_sock(sk);
1958         if (sk->sk_state == IUCV_CONNECTED) {
1959                 sk->sk_state = IUCV_DISCONN;
1960                 sk->sk_state_change(sk);
1961         }
1962         bh_unlock_sock(sk);
1963 out:
1964         kfree_skb(skb);
1965         return NET_RX_SUCCESS;
1966 }
1967
1968 /**
1969  * afiucv_hs_callback_win() - react on received WIN
1970  **/
1971 static int afiucv_hs_callback_win(struct sock *sk, struct sk_buff *skb)
1972 {
1973         struct iucv_sock *iucv = iucv_sk(sk);
1974
1975         if (!iucv)
1976                 return NET_RX_SUCCESS;
1977
1978         if (sk->sk_state != IUCV_CONNECTED)
1979                 return NET_RX_SUCCESS;
1980
1981         atomic_sub(iucv_trans_hdr(skb)->window, &iucv->msg_sent);
1982         iucv_sock_wake_msglim(sk);
1983         return NET_RX_SUCCESS;
1984 }
1985
1986 /**
1987  * afiucv_hs_callback_rx() - react on received data
1988  **/
1989 static int afiucv_hs_callback_rx(struct sock *sk, struct sk_buff *skb)
1990 {
1991         struct iucv_sock *iucv = iucv_sk(sk);
1992
1993         if (!iucv) {
1994                 kfree_skb(skb);
1995                 return NET_RX_SUCCESS;
1996         }
1997
1998         if (sk->sk_state != IUCV_CONNECTED) {
1999                 kfree_skb(skb);
2000                 return NET_RX_SUCCESS;
2001         }
2002
2003         if (sk->sk_shutdown & RCV_SHUTDOWN) {
2004                 kfree_skb(skb);
2005                 return NET_RX_SUCCESS;
2006         }
2007
2008         /* write stuff from iucv_msg to skb cb */
2009         skb_pull(skb, sizeof(struct af_iucv_trans_hdr));
2010         skb_reset_transport_header(skb);
2011         skb_reset_network_header(skb);
2012         IUCV_SKB_CB(skb)->offset = 0;
2013         if (sk_filter(sk, skb)) {
2014                 atomic_inc(&sk->sk_drops);      /* skb rejected by filter */
2015                 kfree_skb(skb);
2016                 return NET_RX_SUCCESS;
2017         }
2018
2019         spin_lock(&iucv->message_q.lock);
2020         if (skb_queue_empty(&iucv->backlog_skb_q)) {
2021                 if (__sock_queue_rcv_skb(sk, skb))
2022                         /* handle rcv queue full */
2023                         skb_queue_tail(&iucv->backlog_skb_q, skb);
2024         } else
2025                 skb_queue_tail(&iucv_sk(sk)->backlog_skb_q, skb);
2026         spin_unlock(&iucv->message_q.lock);
2027         return NET_RX_SUCCESS;
2028 }
2029
2030 /**
2031  * afiucv_hs_rcv() - base function for arriving data through HiperSockets
2032  *                   transport
2033  *                   called from netif RX softirq
2034  **/
2035 static int afiucv_hs_rcv(struct sk_buff *skb, struct net_device *dev,
2036         struct packet_type *pt, struct net_device *orig_dev)
2037 {
2038         struct sock *sk;
2039         struct iucv_sock *iucv;
2040         struct af_iucv_trans_hdr *trans_hdr;
2041         int err = NET_RX_SUCCESS;
2042         char nullstring[8];
2043
2044         if (!pskb_may_pull(skb, sizeof(*trans_hdr))) {
2045                 kfree_skb(skb);
2046                 return NET_RX_SUCCESS;
2047         }
2048
2049         trans_hdr = iucv_trans_hdr(skb);
2050         EBCASC(trans_hdr->destAppName, sizeof(trans_hdr->destAppName));
2051         EBCASC(trans_hdr->destUserID, sizeof(trans_hdr->destUserID));
2052         EBCASC(trans_hdr->srcAppName, sizeof(trans_hdr->srcAppName));
2053         EBCASC(trans_hdr->srcUserID, sizeof(trans_hdr->srcUserID));
2054         memset(nullstring, 0, sizeof(nullstring));
2055         iucv = NULL;
2056         sk = NULL;
2057         read_lock(&iucv_sk_list.lock);
2058         sk_for_each(sk, &iucv_sk_list.head) {
2059                 if (trans_hdr->flags == AF_IUCV_FLAG_SYN) {
2060                         if ((!memcmp(&iucv_sk(sk)->src_name,
2061                                      trans_hdr->destAppName, 8)) &&
2062                             (!memcmp(&iucv_sk(sk)->src_user_id,
2063                                      trans_hdr->destUserID, 8)) &&
2064                             (!memcmp(&iucv_sk(sk)->dst_name, nullstring, 8)) &&
2065                             (!memcmp(&iucv_sk(sk)->dst_user_id,
2066                                      nullstring, 8))) {
2067                                 iucv = iucv_sk(sk);
2068                                 break;
2069                         }
2070                 } else {
2071                         if ((!memcmp(&iucv_sk(sk)->src_name,
2072                                      trans_hdr->destAppName, 8)) &&
2073                             (!memcmp(&iucv_sk(sk)->src_user_id,
2074                                      trans_hdr->destUserID, 8)) &&
2075                             (!memcmp(&iucv_sk(sk)->dst_name,
2076                                      trans_hdr->srcAppName, 8)) &&
2077                             (!memcmp(&iucv_sk(sk)->dst_user_id,
2078                                      trans_hdr->srcUserID, 8))) {
2079                                 iucv = iucv_sk(sk);
2080                                 break;
2081                         }
2082                 }
2083         }
2084         read_unlock(&iucv_sk_list.lock);
2085         if (!iucv)
2086                 sk = NULL;
2087
2088         /* no sock
2089         how should we send with no sock
2090         1) send without sock no send rc checking?
2091         2) introduce default sock to handle this cases
2092
2093          SYN -> send SYN|ACK in good case, send SYN|FIN in bad case
2094          data -> send FIN
2095          SYN|ACK, SYN|FIN, FIN -> no action? */
2096
2097         switch (trans_hdr->flags) {
2098         case AF_IUCV_FLAG_SYN:
2099                 /* connect request */
2100                 err = afiucv_hs_callback_syn(sk, skb);
2101                 break;
2102         case (AF_IUCV_FLAG_SYN | AF_IUCV_FLAG_ACK):
2103                 /* connect request confirmed */
2104                 err = afiucv_hs_callback_synack(sk, skb);
2105                 break;
2106         case (AF_IUCV_FLAG_SYN | AF_IUCV_FLAG_FIN):
2107                 /* connect request refused */
2108                 err = afiucv_hs_callback_synfin(sk, skb);
2109                 break;
2110         case (AF_IUCV_FLAG_FIN):
2111                 /* close request */
2112                 err = afiucv_hs_callback_fin(sk, skb);
2113                 break;
2114         case (AF_IUCV_FLAG_WIN):
2115                 err = afiucv_hs_callback_win(sk, skb);
2116                 if (skb->len == sizeof(struct af_iucv_trans_hdr)) {
2117                         kfree_skb(skb);
2118                         break;
2119                 }
2120                 fallthrough;    /* and receive non-zero length data */
2121         case (AF_IUCV_FLAG_SHT):
2122                 /* shutdown request */
2123                 fallthrough;    /* and receive zero length data */
2124         case 0:
2125                 /* plain data frame */
2126                 IUCV_SKB_CB(skb)->class = trans_hdr->iucv_hdr.class;
2127                 err = afiucv_hs_callback_rx(sk, skb);
2128                 break;
2129         default:
2130                 kfree_skb(skb);
2131         }
2132
2133         return err;
2134 }
2135
2136 /**
2137  * afiucv_hs_callback_txnotify() - handle send notifcations from HiperSockets
2138  *                                 transport
2139  **/
2140 static void afiucv_hs_callback_txnotify(struct sock *sk, enum iucv_tx_notify n)
2141 {
2142         struct iucv_sock *iucv = iucv_sk(sk);
2143
2144         if (sock_flag(sk, SOCK_ZAPPED))
2145                 return;
2146
2147         switch (n) {
2148         case TX_NOTIFY_OK:
2149                 atomic_dec(&iucv->skbs_in_xmit);
2150                 iucv_sock_wake_msglim(sk);
2151                 break;
2152         case TX_NOTIFY_PENDING:
2153                 atomic_inc(&iucv->pendings);
2154                 break;
2155         case TX_NOTIFY_DELAYED_OK:
2156                 atomic_dec(&iucv->skbs_in_xmit);
2157                 if (atomic_dec_return(&iucv->pendings) <= 0)
2158                         iucv_sock_wake_msglim(sk);
2159                 break;
2160         default:
2161                 atomic_dec(&iucv->skbs_in_xmit);
2162                 if (sk->sk_state == IUCV_CONNECTED) {
2163                         sk->sk_state = IUCV_DISCONN;
2164                         sk->sk_state_change(sk);
2165                 }
2166         }
2167
2168         if (sk->sk_state == IUCV_CLOSING) {
2169                 if (atomic_read(&iucv->skbs_in_xmit) == 0) {
2170                         sk->sk_state = IUCV_CLOSED;
2171                         sk->sk_state_change(sk);
2172                 }
2173         }
2174 }
2175
2176 /*
2177  * afiucv_netdev_event: handle netdev notifier chain events
2178  */
2179 static int afiucv_netdev_event(struct notifier_block *this,
2180                                unsigned long event, void *ptr)
2181 {
2182         struct net_device *event_dev = netdev_notifier_info_to_dev(ptr);
2183         struct sock *sk;
2184         struct iucv_sock *iucv;
2185
2186         switch (event) {
2187         case NETDEV_REBOOT:
2188         case NETDEV_GOING_DOWN:
2189                 sk_for_each(sk, &iucv_sk_list.head) {
2190                         iucv = iucv_sk(sk);
2191                         if ((iucv->hs_dev == event_dev) &&
2192                             (sk->sk_state == IUCV_CONNECTED)) {
2193                                 if (event == NETDEV_GOING_DOWN)
2194                                         iucv_send_ctrl(sk, AF_IUCV_FLAG_FIN);
2195                                 sk->sk_state = IUCV_DISCONN;
2196                                 sk->sk_state_change(sk);
2197                         }
2198                 }
2199                 break;
2200         case NETDEV_DOWN:
2201         case NETDEV_UNREGISTER:
2202         default:
2203                 break;
2204         }
2205         return NOTIFY_DONE;
2206 }
2207
2208 static struct notifier_block afiucv_netdev_notifier = {
2209         .notifier_call = afiucv_netdev_event,
2210 };
2211
2212 static const struct proto_ops iucv_sock_ops = {
2213         .family         = PF_IUCV,
2214         .owner          = THIS_MODULE,
2215         .release        = iucv_sock_release,
2216         .bind           = iucv_sock_bind,
2217         .connect        = iucv_sock_connect,
2218         .listen         = iucv_sock_listen,
2219         .accept         = iucv_sock_accept,
2220         .getname        = iucv_sock_getname,
2221         .sendmsg        = iucv_sock_sendmsg,
2222         .recvmsg        = iucv_sock_recvmsg,
2223         .poll           = iucv_sock_poll,
2224         .ioctl          = sock_no_ioctl,
2225         .mmap           = sock_no_mmap,
2226         .socketpair     = sock_no_socketpair,
2227         .shutdown       = iucv_sock_shutdown,
2228         .setsockopt     = iucv_sock_setsockopt,
2229         .getsockopt     = iucv_sock_getsockopt,
2230 };
2231
2232 static int iucv_sock_create(struct net *net, struct socket *sock, int protocol,
2233                             int kern)
2234 {
2235         struct sock *sk;
2236
2237         if (protocol && protocol != PF_IUCV)
2238                 return -EPROTONOSUPPORT;
2239
2240         sock->state = SS_UNCONNECTED;
2241
2242         switch (sock->type) {
2243         case SOCK_STREAM:
2244         case SOCK_SEQPACKET:
2245                 /* currently, proto ops can handle both sk types */
2246                 sock->ops = &iucv_sock_ops;
2247                 break;
2248         default:
2249                 return -ESOCKTNOSUPPORT;
2250         }
2251
2252         sk = iucv_sock_alloc(sock, protocol, GFP_KERNEL, kern);
2253         if (!sk)
2254                 return -ENOMEM;
2255
2256         iucv_sock_init(sk, NULL);
2257
2258         return 0;
2259 }
2260
2261 static const struct net_proto_family iucv_sock_family_ops = {
2262         .family = AF_IUCV,
2263         .owner  = THIS_MODULE,
2264         .create = iucv_sock_create,
2265 };
2266
2267 static struct packet_type iucv_packet_type = {
2268         .type = cpu_to_be16(ETH_P_AF_IUCV),
2269         .func = afiucv_hs_rcv,
2270 };
2271
2272 static int afiucv_iucv_init(void)
2273 {
2274         return pr_iucv->iucv_register(&af_iucv_handler, 0);
2275 }
2276
2277 static void afiucv_iucv_exit(void)
2278 {
2279         pr_iucv->iucv_unregister(&af_iucv_handler, 0);
2280 }
2281
2282 static int __init afiucv_init(void)
2283 {
2284         int err;
2285
2286         if (MACHINE_IS_VM) {
2287                 cpcmd("QUERY USERID", iucv_userid, sizeof(iucv_userid), &err);
2288                 if (unlikely(err)) {
2289                         WARN_ON(err);
2290                         err = -EPROTONOSUPPORT;
2291                         goto out;
2292                 }
2293
2294                 pr_iucv = try_then_request_module(symbol_get(iucv_if), "iucv");
2295                 if (!pr_iucv) {
2296                         printk(KERN_WARNING "iucv_if lookup failed\n");
2297                         memset(&iucv_userid, 0, sizeof(iucv_userid));
2298                 }
2299         } else {
2300                 memset(&iucv_userid, 0, sizeof(iucv_userid));
2301                 pr_iucv = NULL;
2302         }
2303
2304         err = proto_register(&iucv_proto, 0);
2305         if (err)
2306                 goto out;
2307         err = sock_register(&iucv_sock_family_ops);
2308         if (err)
2309                 goto out_proto;
2310
2311         if (pr_iucv) {
2312                 err = afiucv_iucv_init();
2313                 if (err)
2314                         goto out_sock;
2315         }
2316
2317         err = register_netdevice_notifier(&afiucv_netdev_notifier);
2318         if (err)
2319                 goto out_notifier;
2320
2321         dev_add_pack(&iucv_packet_type);
2322         return 0;
2323
2324 out_notifier:
2325         if (pr_iucv)
2326                 afiucv_iucv_exit();
2327 out_sock:
2328         sock_unregister(PF_IUCV);
2329 out_proto:
2330         proto_unregister(&iucv_proto);
2331 out:
2332         if (pr_iucv)
2333                 symbol_put(iucv_if);
2334         return err;
2335 }
2336
2337 static void __exit afiucv_exit(void)
2338 {
2339         if (pr_iucv) {
2340                 afiucv_iucv_exit();
2341                 symbol_put(iucv_if);
2342         }
2343
2344         unregister_netdevice_notifier(&afiucv_netdev_notifier);
2345         dev_remove_pack(&iucv_packet_type);
2346         sock_unregister(PF_IUCV);
2347         proto_unregister(&iucv_proto);
2348 }
2349
2350 module_init(afiucv_init);
2351 module_exit(afiucv_exit);
2352
2353 MODULE_AUTHOR("Jennifer Hunt <jenhunt@us.ibm.com>");
2354 MODULE_DESCRIPTION("IUCV Sockets ver " VERSION);
2355 MODULE_VERSION(VERSION);
2356 MODULE_LICENSE("GPL");
2357 MODULE_ALIAS_NETPROTO(PF_IUCV);