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