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 sk_buff *, 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 (skb_queue_len(&iucv->send_skb_q) < 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         struct sk_buff *nskb;
 215         int err, confirm_recv = 0;
 216
 217         phs_hdr = skb_push(skb, sizeof(*phs_hdr));
 218         memset(phs_hdr, 0, sizeof(*phs_hdr));
 219         skb_reset_network_header(skb);
 220
 221         phs_hdr->magic = ETH_P_AF_IUCV;
 222         phs_hdr->version = 1;
 223         phs_hdr->flags = flags;
 224         if (flags == AF_IUCV_FLAG_SYN)
 225                 phs_hdr->window = iucv->msglimit;
 226         else if ((flags == AF_IUCV_FLAG_WIN) || !flags) {
 227                 confirm_recv = atomic_read(&iucv->msg_recv);
 228                 phs_hdr->window = confirm_recv;
 229                 if (confirm_recv)
 230                         phs_hdr->flags = phs_hdr->flags | AF_IUCV_FLAG_WIN;
 231         }
 232         memcpy(phs_hdr->destUserID, iucv->dst_user_id, 8);
 233         memcpy(phs_hdr->destAppName, iucv->dst_name, 8);
 234         memcpy(phs_hdr->srcUserID, iucv->src_user_id, 8);
 235         memcpy(phs_hdr->srcAppName, iucv->src_name, 8);
 236         ASCEBC(phs_hdr->destUserID, sizeof(phs_hdr->destUserID));
 237         ASCEBC(phs_hdr->destAppName, sizeof(phs_hdr->destAppName));
 238         ASCEBC(phs_hdr->srcUserID, sizeof(phs_hdr->srcUserID));
 239         ASCEBC(phs_hdr->srcAppName, sizeof(phs_hdr->srcAppName));
 240         if (imsg)
 241                 memcpy(&phs_hdr->iucv_hdr, imsg, sizeof(struct iucv_message));
 242
 243         skb->dev = iucv->hs_dev;
 244         if (!skb->dev) {
 245                 err = -ENODEV;
 246                 goto err_free;
 247         }
 248
 249         dev_hard_header(skb, skb->dev, ETH_P_AF_IUCV, NULL, NULL, skb->len);
 250
 251         if (!(skb->dev->flags & IFF_UP) || !netif_carrier_ok(skb->dev)) {
 252                 err = -ENETDOWN;
 253                 goto err_free;
 254         }
 255         if (skb->len > skb->dev->mtu) {
 256                 if (sock->sk_type == SOCK_SEQPACKET) {
 257                         err = -EMSGSIZE;
 258                         goto err_free;
 259                 }
 260                 skb_trim(skb, skb->dev->mtu);
 261         }
 262         skb->protocol = cpu_to_be16(ETH_P_AF_IUCV);
 263
 264         __skb_header_release(skb);
 265         nskb = skb_clone(skb, GFP_ATOMIC);
 266         if (!nskb) {
 267                 err = -ENOMEM;
 268                 goto err_free;
 269         }
 270
 271         skb_queue_tail(&iucv->send_skb_q, nskb);
 272         err = dev_queue_xmit(skb);
 273         if (net_xmit_eval(err)) {
 274                 skb_unlink(nskb, &iucv->send_skb_q);
 275                 kfree_skb(nskb);
 276         } else {
 277                 atomic_sub(confirm_recv, &iucv->msg_recv);
 278                 WARN_ON(atomic_read(&iucv->msg_recv) < 0);
 279         }
 280         return net_xmit_eval(err);
 281
 282 err_free:
 283         kfree_skb(skb);
 284         return err;
 285 }
 286
 287 static struct sock *__iucv_get_sock_by_name(char *nm)
 288 {
 289         struct sock *sk;
 290
 291         sk_for_each(sk, &iucv_sk_list.head)
 292                 if (!memcmp(&iucv_sk(sk)->src_name, nm, 8))
 293                         return sk;
 294
 295         return NULL;
 296 }
 297
 298 static void iucv_sock_destruct(struct sock *sk)
 299 {
 300         skb_queue_purge(&sk->sk_receive_queue);
 301         skb_queue_purge(&sk->sk_error_queue);
 302
 303         sk_mem_reclaim(sk);
 304
 305         if (!sock_flag(sk, SOCK_DEAD)) {
 306                 pr_err("Attempt to release alive iucv socket %p\n", sk);
 307                 return;
 308         }
 309
 310         WARN_ON(atomic_read(&sk->sk_rmem_alloc));
 311         WARN_ON(refcount_read(&sk->sk_wmem_alloc));
 312         WARN_ON(sk->sk_wmem_queued);
 313         WARN_ON(sk->sk_forward_alloc);
 314 }
 315
 316 /* Cleanup Listen */
 317 static void iucv_sock_cleanup_listen(struct sock *parent)
 318 {
 319         struct sock *sk;
 320
 321         /* Close non-accepted connections */
 322         while ((sk = iucv_accept_dequeue(parent, NULL))) {
 323                 iucv_sock_close(sk);
 324                 iucv_sock_kill(sk);
 325         }
 326
 327         parent->sk_state = IUCV_CLOSED;
 328 }
 329
 330 static void iucv_sock_link(struct iucv_sock_list *l, struct sock *sk)
 331 {
 332         write_lock_bh(&l->lock);
 333         sk_add_node(sk, &l->head);
 334         write_unlock_bh(&l->lock);
 335 }
 336
 337 static void iucv_sock_unlink(struct iucv_sock_list *l, struct sock *sk)
 338 {
 339         write_lock_bh(&l->lock);
 340         sk_del_node_init(sk);
 341         write_unlock_bh(&l->lock);
 342 }
 343
 344 /* Kill socket (only if zapped and orphaned) */
 345 static void iucv_sock_kill(struct sock *sk)
 346 {
 347         if (!sock_flag(sk, SOCK_ZAPPED) || sk->sk_socket)
 348                 return;
 349
 350         iucv_sock_unlink(&iucv_sk_list, sk);
 351         sock_set_flag(sk, SOCK_DEAD);
 352         sock_put(sk);
 353 }
 354
 355 /* Terminate an IUCV path */
 356 static void iucv_sever_path(struct sock *sk, int with_user_data)
 357 {
 358         unsigned char user_data[16];
 359         struct iucv_sock *iucv = iucv_sk(sk);
 360         struct iucv_path *path = iucv->path;
 361
 362         if (iucv->path) {
 363                 iucv->path = NULL;
 364                 if (with_user_data) {
 365                         low_nmcpy(user_data, iucv->src_name);
 366                         high_nmcpy(user_data, iucv->dst_name);
 367                         ASCEBC(user_data, sizeof(user_data));
 368                         pr_iucv->path_sever(path, user_data);
 369                 } else
 370                         pr_iucv->path_sever(path, NULL);
 371                 iucv_path_free(path);
 372         }
 373 }
 374
 375 /* Send controlling flags through an IUCV socket for HIPER transport */
 376 static int iucv_send_ctrl(struct sock *sk, u8 flags)
 377 {
 378         struct iucv_sock *iucv = iucv_sk(sk);
 379         int err = 0;
 380         int blen;
 381         struct sk_buff *skb;
 382         u8 shutdown = 0;
 383
 384         blen = sizeof(struct af_iucv_trans_hdr) +
 385                LL_RESERVED_SPACE(iucv->hs_dev);
 386         if (sk->sk_shutdown & SEND_SHUTDOWN) {
 387                 /* controlling flags should be sent anyway */
 388                 shutdown = sk->sk_shutdown;
 389                 sk->sk_shutdown &= RCV_SHUTDOWN;
 390         }
 391         skb = sock_alloc_send_skb(sk, blen, 1, &err);
 392         if (skb) {
 393                 skb_reserve(skb, blen);
 394                 err = afiucv_hs_send(NULL, sk, skb, flags);
 395         }
 396         if (shutdown)
 397                 sk->sk_shutdown = shutdown;
 398         return err;
 399 }
 400
 401 /* Close an IUCV socket */
 402 static void iucv_sock_close(struct sock *sk)
 403 {
 404         struct iucv_sock *iucv = iucv_sk(sk);
 405         unsigned long timeo;
 406         int err = 0;
 407
 408         lock_sock(sk);
 409
 410         switch (sk->sk_state) {
 411         case IUCV_LISTEN:
 412                 iucv_sock_cleanup_listen(sk);
 413                 break;
 414
 415         case IUCV_CONNECTED:
 416                 if (iucv->transport == AF_IUCV_TRANS_HIPER) {
 417                         err = iucv_send_ctrl(sk, AF_IUCV_FLAG_FIN);
 418                         sk->sk_state = IUCV_DISCONN;
 419                         sk->sk_state_change(sk);
 420                 }
 421                 fallthrough;
 422
 423         case IUCV_DISCONN:
 424                 sk->sk_state = IUCV_CLOSING;
 425                 sk->sk_state_change(sk);
 426
 427                 if (!err && !skb_queue_empty(&iucv->send_skb_q)) {
 428                         if (sock_flag(sk, SOCK_LINGER) && sk->sk_lingertime)
 429                                 timeo = sk->sk_lingertime;
 430                         else
 431                                 timeo = IUCV_DISCONN_TIMEOUT;
 432                         iucv_sock_wait(sk,
 433                                         iucv_sock_in_state(sk, IUCV_CLOSED, 0),
 434                                         timeo);
 435                 }
 436                 fallthrough;
 437
 438         case IUCV_CLOSING:
 439                 sk->sk_state = IUCV_CLOSED;
 440                 sk->sk_state_change(sk);
 441
 442                 sk->sk_err = ECONNRESET;
 443                 sk->sk_state_change(sk);
 444
 445                 skb_queue_purge(&iucv->send_skb_q);
 446                 skb_queue_purge(&iucv->backlog_skb_q);
 447                 fallthrough;
 448
 449         default:
 450                 iucv_sever_path(sk, 1);
 451         }
 452
 453         if (iucv->hs_dev) {
 454                 dev_put(iucv->hs_dev);
 455                 iucv->hs_dev = NULL;
 456                 sk->sk_bound_dev_if = 0;
 457         }
 458
 459         /* mark socket for deletion by iucv_sock_kill() */
 460         sock_set_flag(sk, SOCK_ZAPPED);
 461
 462         release_sock(sk);
 463 }
 464
 465 static void iucv_sock_init(struct sock *sk, struct sock *parent)
 466 {
 467         if (parent) {
 468                 sk->sk_type = parent->sk_type;
 469                 security_sk_clone(parent, sk);
 470         }
 471 }
 472
 473 static struct sock *iucv_sock_alloc(struct socket *sock, int proto, gfp_t prio, int kern)
 474 {
 475         struct sock *sk;
 476         struct iucv_sock *iucv;
 477
 478         sk = sk_alloc(&init_net, PF_IUCV, prio, &iucv_proto, kern);
 479         if (!sk)
 480                 return NULL;
 481         iucv = iucv_sk(sk);
 482
 483         sock_init_data(sock, sk);
 484         INIT_LIST_HEAD(&iucv->accept_q);
 485         spin_lock_init(&iucv->accept_q_lock);
 486         skb_queue_head_init(&iucv->send_skb_q);
 487         INIT_LIST_HEAD(&iucv->message_q.list);
 488         spin_lock_init(&iucv->message_q.lock);
 489         skb_queue_head_init(&iucv->backlog_skb_q);
 490         iucv->send_tag = 0;
 491         atomic_set(&iucv->pendings, 0);
 492         iucv->flags = 0;
 493         iucv->msglimit = 0;
 494         atomic_set(&iucv->msg_sent, 0);
 495         atomic_set(&iucv->msg_recv, 0);
 496         iucv->path = NULL;
 497         iucv->sk_txnotify = afiucv_hs_callback_txnotify;
 498         memset(&iucv->src_user_id , 0, 32);
 499         if (pr_iucv)
 500                 iucv->transport = AF_IUCV_TRANS_IUCV;
 501         else
 502                 iucv->transport = AF_IUCV_TRANS_HIPER;
 503
 504         sk->sk_destruct = iucv_sock_destruct;
 505         sk->sk_sndtimeo = IUCV_CONN_TIMEOUT;
 506
 507         sock_reset_flag(sk, SOCK_ZAPPED);
 508
 509         sk->sk_protocol = proto;
 510         sk->sk_state    = IUCV_OPEN;
 511
 512         iucv_sock_link(&iucv_sk_list, sk);
 513         return sk;
 514 }
 515
 516 static void iucv_accept_enqueue(struct sock *parent, struct sock *sk)
 517 {
 518         unsigned long flags;
 519         struct iucv_sock *par = iucv_sk(parent);
 520
 521         sock_hold(sk);
 522         spin_lock_irqsave(&par->accept_q_lock, flags);
 523         list_add_tail(&iucv_sk(sk)->accept_q, &par->accept_q);
 524         spin_unlock_irqrestore(&par->accept_q_lock, flags);
 525         iucv_sk(sk)->parent = parent;
 526         sk_acceptq_added(parent);
 527 }
 528
 529 static void iucv_accept_unlink(struct sock *sk)
 530 {
 531         unsigned long flags;
 532         struct iucv_sock *par = iucv_sk(iucv_sk(sk)->parent);
 533
 534         spin_lock_irqsave(&par->accept_q_lock, flags);
 535         list_del_init(&iucv_sk(sk)->accept_q);
 536         spin_unlock_irqrestore(&par->accept_q_lock, flags);
 537         sk_acceptq_removed(iucv_sk(sk)->parent);
 538         iucv_sk(sk)->parent = NULL;
 539         sock_put(sk);
 540 }
 541
 542 static struct sock *iucv_accept_dequeue(struct sock *parent,
 543                                         struct socket *newsock)
 544 {
 545         struct iucv_sock *isk, *n;
 546         struct sock *sk;
 547
 548         list_for_each_entry_safe(isk, n, &iucv_sk(parent)->accept_q, accept_q) {
 549                 sk = (struct sock *) isk;
 550                 lock_sock(sk);
 551
 552                 if (sk->sk_state == IUCV_CLOSED) {
 553                         iucv_accept_unlink(sk);
 554                         release_sock(sk);
 555                         continue;
 556                 }
 557
 558                 if (sk->sk_state == IUCV_CONNECTED ||
 559                     sk->sk_state == IUCV_DISCONN ||
 560                     !newsock) {
 561                         iucv_accept_unlink(sk);
 562                         if (newsock)
 563                                 sock_graft(sk, newsock);
 564
 565                         release_sock(sk);
 566                         return sk;
 567                 }
 568
 569                 release_sock(sk);
 570         }
 571         return NULL;
 572 }
 573
 574 static void __iucv_auto_name(struct iucv_sock *iucv)
 575 {
 576         char name[12];
 577
 578         sprintf(name, "%08x", atomic_inc_return(&iucv_sk_list.autobind_name));
 579         while (__iucv_get_sock_by_name(name)) {
 580                 sprintf(name, "%08x",
 581                         atomic_inc_return(&iucv_sk_list.autobind_name));
 582         }
 583         memcpy(iucv->src_name, name, 8);
 584 }
 585
 586 /* Bind an unbound socket */
 587 static int iucv_sock_bind(struct socket *sock, struct sockaddr *addr,
 588                           int addr_len)
 589 {
 590         struct sockaddr_iucv *sa = (struct sockaddr_iucv *) addr;
 591         char uid[sizeof(sa->siucv_user_id)];
 592         struct sock *sk = sock->sk;
 593         struct iucv_sock *iucv;
 594         int err = 0;
 595         struct net_device *dev;
 596
 597         /* Verify the input sockaddr */
 598         if (addr_len < sizeof(struct sockaddr_iucv) ||
 599             addr->sa_family != AF_IUCV)
 600                 return -EINVAL;
 601
 602         lock_sock(sk);
 603         if (sk->sk_state != IUCV_OPEN) {
 604                 err = -EBADFD;
 605                 goto done;
 606         }
 607
 608         write_lock_bh(&iucv_sk_list.lock);
 609
 610         iucv = iucv_sk(sk);
 611         if (__iucv_get_sock_by_name(sa->siucv_name)) {
 612                 err = -EADDRINUSE;
 613                 goto done_unlock;
 614         }
 615         if (iucv->path)
 616                 goto done_unlock;
 617
 618         /* Bind the socket */
 619         if (pr_iucv)
 620                 if (!memcmp(sa->siucv_user_id, iucv_userid, 8))
 621                         goto vm_bind; /* VM IUCV transport */
 622
 623         /* try hiper transport */
 624         memcpy(uid, sa->siucv_user_id, sizeof(uid));
 625         ASCEBC(uid, 8);
 626         rcu_read_lock();
 627         for_each_netdev_rcu(&init_net, dev) {
 628                 if (!memcmp(dev->perm_addr, uid, 8)) {
 629                         memcpy(iucv->src_user_id, sa->siucv_user_id, 8);
 630                         /* Check for unitialized siucv_name */
 631                         if (strncmp(sa->siucv_name, "        ", 8) == 0)
 632                                 __iucv_auto_name(iucv);
 633                         else
 634                                 memcpy(iucv->src_name, sa->siucv_name, 8);
 635                         sk->sk_bound_dev_if = dev->ifindex;
 636                         iucv->hs_dev = dev;
 637                         dev_hold(dev);
 638                         sk->sk_state = IUCV_BOUND;
 639                         iucv->transport = AF_IUCV_TRANS_HIPER;
 640                         if (!iucv->msglimit)
 641                                 iucv->msglimit = IUCV_HIPER_MSGLIM_DEFAULT;
 642                         rcu_read_unlock();
 643                         goto done_unlock;
 644                 }
 645         }
 646         rcu_read_unlock();
 647 vm_bind:
 648         if (pr_iucv) {
 649                 /* use local userid for backward compat */
 650                 memcpy(iucv->src_name, sa->siucv_name, 8);
 651                 memcpy(iucv->src_user_id, iucv_userid, 8);
 652                 sk->sk_state = IUCV_BOUND;
 653                 iucv->transport = AF_IUCV_TRANS_IUCV;
 654                 sk->sk_allocation |= GFP_DMA;
 655                 if (!iucv->msglimit)
 656                         iucv->msglimit = IUCV_QUEUELEN_DEFAULT;
 657                 goto done_unlock;
 658         }
 659         /* found no dev to bind */
 660         err = -ENODEV;
 661 done_unlock:
 662         /* Release the socket list lock */
 663         write_unlock_bh(&iucv_sk_list.lock);
 664 done:
 665         release_sock(sk);
 666         return err;
 667 }
 668
 669 /* Automatically bind an unbound socket */
 670 static int iucv_sock_autobind(struct sock *sk)
 671 {
 672         struct iucv_sock *iucv = iucv_sk(sk);
 673         int err = 0;
 674
 675         if (unlikely(!pr_iucv))
 676                 return -EPROTO;
 677
 678         memcpy(iucv->src_user_id, iucv_userid, 8);
 679         iucv->transport = AF_IUCV_TRANS_IUCV;
 680         sk->sk_allocation |= GFP_DMA;
 681
 682         write_lock_bh(&iucv_sk_list.lock);
 683         __iucv_auto_name(iucv);
 684         write_unlock_bh(&iucv_sk_list.lock);
 685
 686         if (!iucv->msglimit)
 687                 iucv->msglimit = IUCV_QUEUELEN_DEFAULT;
 688
 689         return err;
 690 }
 691
 692 static int afiucv_path_connect(struct socket *sock, struct sockaddr *addr)
 693 {
 694         struct sockaddr_iucv *sa = (struct sockaddr_iucv *) addr;
 695         struct sock *sk = sock->sk;
 696         struct iucv_sock *iucv = iucv_sk(sk);
 697         unsigned char user_data[16];
 698         int err;
 699
 700         high_nmcpy(user_data, sa->siucv_name);
 701         low_nmcpy(user_data, iucv->src_name);
 702         ASCEBC(user_data, sizeof(user_data));
 703
 704         /* Create path. */
 705         iucv->path = iucv_path_alloc(iucv->msglimit,
 706                                      IUCV_IPRMDATA, GFP_KERNEL);
 707         if (!iucv->path) {
 708                 err = -ENOMEM;
 709                 goto done;
 710         }
 711         err = pr_iucv->path_connect(iucv->path, &af_iucv_handler,
 712                                     sa->siucv_user_id, NULL, user_data,
 713                                     sk);
 714         if (err) {
 715                 iucv_path_free(iucv->path);
 716                 iucv->path = NULL;
 717                 switch (err) {
 718                 case 0x0b:      /* Target communicator is not logged on */
 719                         err = -ENETUNREACH;
 720                         break;
 721                 case 0x0d:      /* Max connections for this guest exceeded */
 722                 case 0x0e:      /* Max connections for target guest exceeded */
 723                         err = -EAGAIN;
 724                         break;
 725                 case 0x0f:      /* Missing IUCV authorization */
 726                         err = -EACCES;
 727                         break;
 728                 default:
 729                         err = -ECONNREFUSED;
 730                         break;
 731                 }
 732         }
 733 done:
 734         return err;
 735 }
 736
 737 /* Connect an unconnected socket */
 738 static int iucv_sock_connect(struct socket *sock, struct sockaddr *addr,
 739                              int alen, int flags)
 740 {
 741         struct sockaddr_iucv *sa = (struct sockaddr_iucv *) addr;
 742         struct sock *sk = sock->sk;
 743         struct iucv_sock *iucv = iucv_sk(sk);
 744         int err;
 745
 746         if (alen < sizeof(struct sockaddr_iucv) || addr->sa_family != AF_IUCV)
 747                 return -EINVAL;
 748
 749         if (sk->sk_state != IUCV_OPEN && sk->sk_state != IUCV_BOUND)
 750                 return -EBADFD;
 751
 752         if (sk->sk_state == IUCV_OPEN &&
 753             iucv->transport == AF_IUCV_TRANS_HIPER)
 754                 return -EBADFD; /* explicit bind required */
 755
 756         if (sk->sk_type != SOCK_STREAM && sk->sk_type != SOCK_SEQPACKET)
 757                 return -EINVAL;
 758
 759         if (sk->sk_state == IUCV_OPEN) {
 760                 err = iucv_sock_autobind(sk);
 761                 if (unlikely(err))
 762                         return err;
 763         }
 764
 765         lock_sock(sk);
 766
 767         /* Set the destination information */
 768         memcpy(iucv->dst_user_id, sa->siucv_user_id, 8);
 769         memcpy(iucv->dst_name, sa->siucv_name, 8);
 770
 771         if (iucv->transport == AF_IUCV_TRANS_HIPER)
 772                 err = iucv_send_ctrl(sock->sk, AF_IUCV_FLAG_SYN);
 773         else
 774                 err = afiucv_path_connect(sock, addr);
 775         if (err)
 776                 goto done;
 777
 778         if (sk->sk_state != IUCV_CONNECTED)
 779                 err = iucv_sock_wait(sk, iucv_sock_in_state(sk, IUCV_CONNECTED,
 780                                                             IUCV_DISCONN),
 781                                      sock_sndtimeo(sk, flags & O_NONBLOCK));
 782
 783         if (sk->sk_state == IUCV_DISCONN || sk->sk_state == IUCV_CLOSED)
 784                 err = -ECONNREFUSED;
 785
 786         if (err && iucv->transport == AF_IUCV_TRANS_IUCV)
 787                 iucv_sever_path(sk, 0);
 788
 789 done:
 790         release_sock(sk);
 791         return err;
 792 }
 793
 794 /* Move a socket into listening state. */
 795 static int iucv_sock_listen(struct socket *sock, int backlog)
 796 {
 797         struct sock *sk = sock->sk;
 798         int err;
 799
 800         lock_sock(sk);
 801
 802         err = -EINVAL;
 803         if (sk->sk_state != IUCV_BOUND)
 804                 goto done;
 805
 806         if (sock->type != SOCK_STREAM && sock->type != SOCK_SEQPACKET)
 807                 goto done;
 808
 809         sk->sk_max_ack_backlog = backlog;
 810         sk->sk_ack_backlog = 0;
 811         sk->sk_state = IUCV_LISTEN;
 812         err = 0;
 813
 814 done:
 815         release_sock(sk);
 816         return err;
 817 }
 818
 819 /* Accept a pending connection */
 820 static int iucv_sock_accept(struct socket *sock, struct socket *newsock,
 821                             int flags, bool kern)
 822 {
 823         DECLARE_WAITQUEUE(wait, current);
 824         struct sock *sk = sock->sk, *nsk;
 825         long timeo;
 826         int err = 0;
 827
 828         lock_sock_nested(sk, SINGLE_DEPTH_NESTING);
 829
 830         if (sk->sk_state != IUCV_LISTEN) {
 831                 err = -EBADFD;
 832                 goto done;
 833         }
 834
 835         timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);
 836
 837         /* Wait for an incoming connection */
 838         add_wait_queue_exclusive(sk_sleep(sk), &wait);
 839         while (!(nsk = iucv_accept_dequeue(sk, newsock))) {
 840                 set_current_state(TASK_INTERRUPTIBLE);
 841                 if (!timeo) {
 842                         err = -EAGAIN;
 843                         break;
 844                 }
 845
 846                 release_sock(sk);
 847                 timeo = schedule_timeout(timeo);
 848                 lock_sock_nested(sk, SINGLE_DEPTH_NESTING);
 849
 850                 if (sk->sk_state != IUCV_LISTEN) {
 851                         err = -EBADFD;
 852                         break;
 853                 }
 854
 855                 if (signal_pending(current)) {
 856                         err = sock_intr_errno(timeo);
 857                         break;
 858                 }
 859         }
 860
 861         set_current_state(TASK_RUNNING);
 862         remove_wait_queue(sk_sleep(sk), &wait);
 863
 864         if (err)
 865                 goto done;
 866
 867         newsock->state = SS_CONNECTED;
 868
 869 done:
 870         release_sock(sk);
 871         return err;
 872 }
 873
 874 static int iucv_sock_getname(struct socket *sock, struct sockaddr *addr,
 875                              int peer)
 876 {
 877         struct sockaddr_iucv *siucv = (struct sockaddr_iucv *) addr;
 878         struct sock *sk = sock->sk;
 879         struct iucv_sock *iucv = iucv_sk(sk);
 880
 881         addr->sa_family = AF_IUCV;
 882
 883         if (peer) {
 884                 memcpy(siucv->siucv_user_id, iucv->dst_user_id, 8);
 885                 memcpy(siucv->siucv_name, iucv->dst_name, 8);
 886         } else {
 887                 memcpy(siucv->siucv_user_id, iucv->src_user_id, 8);
 888                 memcpy(siucv->siucv_name, iucv->src_name, 8);
 889         }
 890         memset(&siucv->siucv_port, 0, sizeof(siucv->siucv_port));
 891         memset(&siucv->siucv_addr, 0, sizeof(siucv->siucv_addr));
 892         memset(&siucv->siucv_nodeid, 0, sizeof(siucv->siucv_nodeid));
 893
 894         return sizeof(struct sockaddr_iucv);
 895 }
 896
 897 /**
 898  * iucv_send_iprm() - Send socket data in parameter list of an iucv message.
 899  * @path:       IUCV path
 900  * @msg:        Pointer to a struct iucv_message
 901  * @skb:        The socket data to send, skb->len MUST BE <= 7
 902  *
 903  * Send the socket data in the parameter list in the iucv message
 904  * (IUCV_IPRMDATA). The socket data is stored at index 0 to 6 in the parameter
 905  * list and the socket data len at index 7 (last byte).
 906  * See also iucv_msg_length().
 907  *
 908  * Returns the error code from the iucv_message_send() call.
 909  */
 910 static int iucv_send_iprm(struct iucv_path *path, struct iucv_message *msg,
 911                           struct sk_buff *skb)
 912 {
 913         u8 prmdata[8];
 914
 915         memcpy(prmdata, (void *) skb->data, skb->len);
 916         prmdata[7] = 0xff - (u8) skb->len;
 917         return pr_iucv->message_send(path, msg, IUCV_IPRMDATA, 0,
 918                                  (void *) prmdata, 8);
 919 }
 920
 921 static int iucv_sock_sendmsg(struct socket *sock, struct msghdr *msg,
 922                              size_t len)
 923 {
 924         struct sock *sk = sock->sk;
 925         struct iucv_sock *iucv = iucv_sk(sk);
 926         size_t headroom = 0;
 927         size_t linear;
 928         struct sk_buff *skb;
 929         struct iucv_message txmsg = {0};
 930         struct cmsghdr *cmsg;
 931         int cmsg_done;
 932         long timeo;
 933         char user_id[9];
 934         char appl_id[9];
 935         int err;
 936         int noblock = msg->msg_flags & MSG_DONTWAIT;
 937
 938         err = sock_error(sk);
 939         if (err)
 940                 return err;
 941
 942         if (msg->msg_flags & MSG_OOB)
 943                 return -EOPNOTSUPP;
 944
 945         /* SOCK_SEQPACKET: we do not support segmented records */
 946         if (sk->sk_type == SOCK_SEQPACKET && !(msg->msg_flags & MSG_EOR))
 947                 return -EOPNOTSUPP;
 948
 949         lock_sock(sk);
 950
 951         if (sk->sk_shutdown & SEND_SHUTDOWN) {
 952                 err = -EPIPE;
 953                 goto out;
 954         }
 955
 956         /* Return if the socket is not in connected state */
 957         if (sk->sk_state != IUCV_CONNECTED) {
 958                 err = -ENOTCONN;
 959                 goto out;
 960         }
 961
 962         /* initialize defaults */
 963         cmsg_done   = 0;        /* check for duplicate headers */
 964
 965         /* iterate over control messages */
 966         for_each_cmsghdr(cmsg, msg) {
 967                 if (!CMSG_OK(msg, cmsg)) {
 968                         err = -EINVAL;
 969                         goto out;
 970                 }
 971
 972                 if (cmsg->cmsg_level != SOL_IUCV)
 973                         continue;
 974
 975                 if (cmsg->cmsg_type & cmsg_done) {
 976                         err = -EINVAL;
 977                         goto out;
 978                 }
 979                 cmsg_done |= cmsg->cmsg_type;
 980
 981                 switch (cmsg->cmsg_type) {
 982                 case SCM_IUCV_TRGCLS:
 983                         if (cmsg->cmsg_len != CMSG_LEN(TRGCLS_SIZE)) {
 984                                 err = -EINVAL;
 985                                 goto out;
 986                         }
 987
 988                         /* set iucv message target class */
 989                         memcpy(&txmsg.class,
 990                                 (void *) CMSG_DATA(cmsg), TRGCLS_SIZE);
 991
 992                         break;
 993
 994                 default:
 995                         err = -EINVAL;
 996                         goto out;
 997                 }
 998         }
 999
1000         /* allocate one skb for each iucv message:
1001          * this is fine for SOCK_SEQPACKET (unless we want to support
1002          * segmented records using the MSG_EOR flag), but
1003          * for SOCK_STREAM we might want to improve it in future */
1004         if (iucv->transport == AF_IUCV_TRANS_HIPER) {
1005                 headroom = sizeof(struct af_iucv_trans_hdr) +
1006                            LL_RESERVED_SPACE(iucv->hs_dev);
1007                 linear = len;
1008         } else {
1009                 if (len < PAGE_SIZE) {
1010                         linear = len;
1011                 } else {
1012                         /* In nonlinear "classic" iucv skb,
1013                          * reserve space for iucv_array
1014                          */
1015                         headroom = sizeof(struct iucv_array) *
1016                                    (MAX_SKB_FRAGS + 1);
1017                         linear = PAGE_SIZE - headroom;
1018                 }
1019         }
1020         skb = sock_alloc_send_pskb(sk, headroom + linear, len - linear,
1021                                    noblock, &err, 0);
1022         if (!skb)
1023                 goto out;
1024         if (headroom)
1025                 skb_reserve(skb, headroom);
1026         skb_put(skb, linear);
1027         skb->len = len;
1028         skb->data_len = len - linear;
1029         err = skb_copy_datagram_from_iter(skb, 0, &msg->msg_iter, len);
1030         if (err)
1031                 goto fail;
1032
1033         /* wait if outstanding messages for iucv path has reached */
1034         timeo = sock_sndtimeo(sk, noblock);
1035         err = iucv_sock_wait(sk, iucv_below_msglim(sk), timeo);
1036         if (err)
1037                 goto fail;
1038
1039         /* return -ECONNRESET if the socket is no longer connected */
1040         if (sk->sk_state != IUCV_CONNECTED) {
1041                 err = -ECONNRESET;
1042                 goto fail;
1043         }
1044
1045         /* increment and save iucv message tag for msg_completion cbk */
1046         txmsg.tag = iucv->send_tag++;
1047         IUCV_SKB_CB(skb)->tag = txmsg.tag;
1048
1049         if (iucv->transport == AF_IUCV_TRANS_HIPER) {
1050                 atomic_inc(&iucv->msg_sent);
1051                 err = afiucv_hs_send(&txmsg, sk, skb, 0);
1052                 if (err) {
1053                         atomic_dec(&iucv->msg_sent);
1054                         goto out;
1055                 }
1056         } else { /* Classic VM IUCV transport */
1057                 skb_queue_tail(&iucv->send_skb_q, skb);
1058
1059                 if (((iucv->path->flags & IUCV_IPRMDATA) & iucv->flags) &&
1060                     skb->len <= 7) {
1061                         err = iucv_send_iprm(iucv->path, &txmsg, skb);
1062
1063                         /* on success: there is no message_complete callback */
1064                         /* for an IPRMDATA msg; remove skb from send queue   */
1065                         if (err == 0) {
1066                                 skb_unlink(skb, &iucv->send_skb_q);
1067                                 kfree_skb(skb);
1068                         }
1069
1070                         /* this error should never happen since the     */
1071                         /* IUCV_IPRMDATA path flag is set... sever path */
1072                         if (err == 0x15) {
1073                                 pr_iucv->path_sever(iucv->path, NULL);
1074                                 skb_unlink(skb, &iucv->send_skb_q);
1075                                 err = -EPIPE;
1076                                 goto fail;
1077                         }
1078                 } else if (skb_is_nonlinear(skb)) {
1079                         struct iucv_array *iba = (struct iucv_array *)skb->head;
1080                         int i;
1081
1082                         /* skip iucv_array lying in the headroom */
1083                         iba[0].address = (u32)(addr_t)skb->data;
1084                         iba[0].length = (u32)skb_headlen(skb);
1085                         for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
1086                                 skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
1087
1088                                 iba[i + 1].address =
1089                                         (u32)(addr_t)skb_frag_address(frag);
1090                                 iba[i + 1].length = (u32)skb_frag_size(frag);
1091                         }
1092                         err = pr_iucv->message_send(iucv->path, &txmsg,
1093                                                     IUCV_IPBUFLST, 0,
1094                                                     (void *)iba, skb->len);
1095                 } else { /* non-IPRM Linear skb */
1096                         err = pr_iucv->message_send(iucv->path, &txmsg,
1097                                         0, 0, (void *)skb->data, skb->len);
1098                 }
1099                 if (err) {
1100                         if (err == 3) {
1101                                 user_id[8] = 0;
1102                                 memcpy(user_id, iucv->dst_user_id, 8);
1103                                 appl_id[8] = 0;
1104                                 memcpy(appl_id, iucv->dst_name, 8);
1105                                 pr_err(
1106                 "Application %s on z/VM guest %s exceeds message limit\n",
1107                                         appl_id, user_id);
1108                                 err = -EAGAIN;
1109                         } else {
1110                                 err = -EPIPE;
1111                         }
1112                         skb_unlink(skb, &iucv->send_skb_q);
1113                         goto fail;
1114                 }
1115         }
1116
1117         release_sock(sk);
1118         return len;
1119
1120 fail:
1121         kfree_skb(skb);
1122 out:
1123         release_sock(sk);
1124         return err;
1125 }
1126
1127 static struct sk_buff *alloc_iucv_recv_skb(unsigned long len)
1128 {
1129         size_t headroom, linear;
1130         struct sk_buff *skb;
1131         int err;
1132
1133         if (len < PAGE_SIZE) {
1134                 headroom = 0;
1135                 linear = len;
1136         } else {
1137                 headroom = sizeof(struct iucv_array) * (MAX_SKB_FRAGS + 1);
1138                 linear = PAGE_SIZE - headroom;
1139         }
1140         skb = alloc_skb_with_frags(headroom + linear, len - linear,
1141                                    0, &err, GFP_ATOMIC | GFP_DMA);
1142         WARN_ONCE(!skb,
1143                   "alloc of recv iucv skb len=%lu failed with errcode=%d\n",
1144                   len, err);
1145         if (skb) {
1146                 if (headroom)
1147                         skb_reserve(skb, headroom);
1148                 skb_put(skb, linear);
1149                 skb->len = len;
1150                 skb->data_len = len - linear;
1151         }
1152         return skb;
1153 }
1154
1155 /* iucv_process_message() - Receive a single outstanding IUCV message
1156  *
1157  * Locking: must be called with message_q.lock held
1158  */
1159 static void iucv_process_message(struct sock *sk, struct sk_buff *skb,
1160                                  struct iucv_path *path,
1161                                  struct iucv_message *msg)
1162 {
1163         int rc;
1164         unsigned int len;
1165
1166         len = iucv_msg_length(msg);
1167
1168         /* store msg target class in the second 4 bytes of skb ctrl buffer */
1169         /* Note: the first 4 bytes are reserved for msg tag */
1170         IUCV_SKB_CB(skb)->class = msg->class;
1171
1172         /* check for special IPRM messages (e.g. iucv_sock_shutdown) */
1173         if ((msg->flags & IUCV_IPRMDATA) && len > 7) {
1174                 if (memcmp(msg->rmmsg, iprm_shutdown, 8) == 0) {
1175                         skb->data = NULL;
1176                         skb->len = 0;
1177                 }
1178         } else {
1179                 if (skb_is_nonlinear(skb)) {
1180                         struct iucv_array *iba = (struct iucv_array *)skb->head;
1181                         int i;
1182
1183                         iba[0].address = (u32)(addr_t)skb->data;
1184                         iba[0].length = (u32)skb_headlen(skb);
1185                         for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
1186                                 skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
1187
1188                                 iba[i + 1].address =
1189                                         (u32)(addr_t)skb_frag_address(frag);
1190                                 iba[i + 1].length = (u32)skb_frag_size(frag);
1191                         }
1192                         rc = pr_iucv->message_receive(path, msg,
1193                                               IUCV_IPBUFLST,
1194                                               (void *)iba, len, NULL);
1195                 } else {
1196                         rc = pr_iucv->message_receive(path, msg,
1197                                               msg->flags & IUCV_IPRMDATA,
1198                                               skb->data, len, NULL);
1199                 }
1200                 if (rc) {
1201                         kfree_skb(skb);
1202                         return;
1203                 }
1204                 WARN_ON_ONCE(skb->len != len);
1205         }
1206
1207         IUCV_SKB_CB(skb)->offset = 0;
1208         if (sk_filter(sk, skb)) {
1209                 atomic_inc(&sk->sk_drops);      /* skb rejected by filter */
1210                 kfree_skb(skb);
1211                 return;
1212         }
1213         if (__sock_queue_rcv_skb(sk, skb))      /* handle rcv queue full */
1214                 skb_queue_tail(&iucv_sk(sk)->backlog_skb_q, skb);
1215 }
1216
1217 /* iucv_process_message_q() - Process outstanding IUCV messages
1218  *
1219  * Locking: must be called with message_q.lock held
1220  */
1221 static void iucv_process_message_q(struct sock *sk)
1222 {
1223         struct iucv_sock *iucv = iucv_sk(sk);
1224         struct sk_buff *skb;
1225         struct sock_msg_q *p, *n;
1226
1227         list_for_each_entry_safe(p, n, &iucv->message_q.list, list) {
1228                 skb = alloc_iucv_recv_skb(iucv_msg_length(&p->msg));
1229                 if (!skb)
1230                         break;
1231                 iucv_process_message(sk, skb, p->path, &p->msg);
1232                 list_del(&p->list);
1233                 kfree(p);
1234                 if (!skb_queue_empty(&iucv->backlog_skb_q))
1235                         break;
1236         }
1237 }
1238
1239 static int iucv_sock_recvmsg(struct socket *sock, struct msghdr *msg,
1240                              size_t len, int flags)
1241 {
1242         int noblock = flags & MSG_DONTWAIT;
1243         struct sock *sk = sock->sk;
1244         struct iucv_sock *iucv = iucv_sk(sk);
1245         unsigned int copied, rlen;
1246         struct sk_buff *skb, *rskb, *cskb;
1247         int err = 0;
1248         u32 offset;
1249
1250         if ((sk->sk_state == IUCV_DISCONN) &&
1251             skb_queue_empty(&iucv->backlog_skb_q) &&
1252             skb_queue_empty(&sk->sk_receive_queue) &&
1253             list_empty(&iucv->message_q.list))
1254                 return 0;
1255
1256         if (flags & (MSG_OOB))
1257                 return -EOPNOTSUPP;
1258
1259         /* receive/dequeue next skb:
1260          * the function understands MSG_PEEK and, thus, does not dequeue skb */
1261         skb = skb_recv_datagram(sk, flags, noblock, &err);
1262         if (!skb) {
1263                 if (sk->sk_shutdown & RCV_SHUTDOWN)
1264                         return 0;
1265                 return err;
1266         }
1267
1268         offset = IUCV_SKB_CB(skb)->offset;
1269         rlen   = skb->len - offset;             /* real length of skb */
1270         copied = min_t(unsigned int, rlen, len);
1271         if (!rlen)
1272                 sk->sk_shutdown = sk->sk_shutdown | RCV_SHUTDOWN;
1273
1274         cskb = skb;
1275         if (skb_copy_datagram_msg(cskb, offset, msg, copied)) {
1276                 if (!(flags & MSG_PEEK))
1277                         skb_queue_head(&sk->sk_receive_queue, skb);
1278                 return -EFAULT;
1279         }
1280
1281         /* SOCK_SEQPACKET: set MSG_TRUNC if recv buf size is too small */
1282         if (sk->sk_type == SOCK_SEQPACKET) {
1283                 if (copied < rlen)
1284                         msg->msg_flags |= MSG_TRUNC;
1285                 /* each iucv message contains a complete record */
1286                 msg->msg_flags |= MSG_EOR;
1287         }
1288
1289         /* create control message to store iucv msg target class:
1290          * get the trgcls from the control buffer of the skb due to
1291          * fragmentation of original iucv message. */
1292         err = put_cmsg(msg, SOL_IUCV, SCM_IUCV_TRGCLS,
1293                        sizeof(IUCV_SKB_CB(skb)->class),
1294                        (void *)&IUCV_SKB_CB(skb)->class);
1295         if (err) {
1296                 if (!(flags & MSG_PEEK))
1297                         skb_queue_head(&sk->sk_receive_queue, skb);
1298                 return err;
1299         }
1300
1301         /* Mark read part of skb as used */
1302         if (!(flags & MSG_PEEK)) {
1303
1304                 /* SOCK_STREAM: re-queue skb if it contains unreceived data */
1305                 if (sk->sk_type == SOCK_STREAM) {
1306                         if (copied < rlen) {
1307                                 IUCV_SKB_CB(skb)->offset = offset + copied;
1308                                 skb_queue_head(&sk->sk_receive_queue, skb);
1309                                 goto done;
1310                         }
1311                 }
1312
1313                 kfree_skb(skb);
1314                 if (iucv->transport == AF_IUCV_TRANS_HIPER) {
1315                         atomic_inc(&iucv->msg_recv);
1316                         if (atomic_read(&iucv->msg_recv) > iucv->msglimit) {
1317                                 WARN_ON(1);
1318                                 iucv_sock_close(sk);
1319                                 return -EFAULT;
1320                         }
1321                 }
1322
1323                 /* Queue backlog skbs */
1324                 spin_lock_bh(&iucv->message_q.lock);
1325                 rskb = skb_dequeue(&iucv->backlog_skb_q);
1326                 while (rskb) {
1327                         IUCV_SKB_CB(rskb)->offset = 0;
1328                         if (__sock_queue_rcv_skb(sk, rskb)) {
1329                                 /* handle rcv queue full */
1330                                 skb_queue_head(&iucv->backlog_skb_q,
1331                                                 rskb);
1332                                 break;
1333                         }
1334                         rskb = skb_dequeue(&iucv->backlog_skb_q);
1335                 }
1336                 if (skb_queue_empty(&iucv->backlog_skb_q)) {
1337                         if (!list_empty(&iucv->message_q.list))
1338                                 iucv_process_message_q(sk);
1339                         if (atomic_read(&iucv->msg_recv) >=
1340                                                         iucv->msglimit / 2) {
1341                                 err = iucv_send_ctrl(sk, AF_IUCV_FLAG_WIN);
1342                                 if (err) {
1343                                         sk->sk_state = IUCV_DISCONN;
1344                                         sk->sk_state_change(sk);
1345                                 }
1346                         }
1347                 }
1348                 spin_unlock_bh(&iucv->message_q.lock);
1349         }
1350
1351 done:
1352         /* SOCK_SEQPACKET: return real length if MSG_TRUNC is set */
1353         if (sk->sk_type == SOCK_SEQPACKET && (flags & MSG_TRUNC))
1354                 copied = rlen;
1355
1356         return copied;
1357 }
1358
1359 static inline __poll_t iucv_accept_poll(struct sock *parent)
1360 {
1361         struct iucv_sock *isk, *n;
1362         struct sock *sk;
1363
1364         list_for_each_entry_safe(isk, n, &iucv_sk(parent)->accept_q, accept_q) {
1365                 sk = (struct sock *) isk;
1366
1367                 if (sk->sk_state == IUCV_CONNECTED)
1368                         return EPOLLIN | EPOLLRDNORM;
1369         }
1370
1371         return 0;
1372 }
1373
1374 static __poll_t iucv_sock_poll(struct file *file, struct socket *sock,
1375                                poll_table *wait)
1376 {
1377         struct sock *sk = sock->sk;
1378         __poll_t mask = 0;
1379
1380         sock_poll_wait(file, sock, wait);
1381
1382         if (sk->sk_state == IUCV_LISTEN)
1383                 return iucv_accept_poll(sk);
1384
1385         if (sk->sk_err || !skb_queue_empty(&sk->sk_error_queue))
1386                 mask |= EPOLLERR |
1387                         (sock_flag(sk, SOCK_SELECT_ERR_QUEUE) ? EPOLLPRI : 0);
1388
1389         if (sk->sk_shutdown & RCV_SHUTDOWN)
1390                 mask |= EPOLLRDHUP;
1391
1392         if (sk->sk_shutdown == SHUTDOWN_MASK)
1393                 mask |= EPOLLHUP;
1394
1395         if (!skb_queue_empty(&sk->sk_receive_queue) ||
1396             (sk->sk_shutdown & RCV_SHUTDOWN))
1397                 mask |= EPOLLIN | EPOLLRDNORM;
1398
1399         if (sk->sk_state == IUCV_CLOSED)
1400                 mask |= EPOLLHUP;
1401
1402         if (sk->sk_state == IUCV_DISCONN)
1403                 mask |= EPOLLIN;
1404
1405         if (sock_writeable(sk) && iucv_below_msglim(sk))
1406                 mask |= EPOLLOUT | EPOLLWRNORM | EPOLLWRBAND;
1407         else
1408                 sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
1409
1410         return mask;
1411 }
1412
1413 static int iucv_sock_shutdown(struct socket *sock, int how)
1414 {
1415         struct sock *sk = sock->sk;
1416         struct iucv_sock *iucv = iucv_sk(sk);
1417         struct iucv_message txmsg;
1418         int err = 0;
1419
1420         how++;
1421
1422         if ((how & ~SHUTDOWN_MASK) || !how)
1423                 return -EINVAL;
1424
1425         lock_sock(sk);
1426         switch (sk->sk_state) {
1427         case IUCV_LISTEN:
1428         case IUCV_DISCONN:
1429         case IUCV_CLOSING:
1430         case IUCV_CLOSED:
1431                 err = -ENOTCONN;
1432                 goto fail;
1433         default:
1434                 break;
1435         }
1436
1437         if (how == SEND_SHUTDOWN || how == SHUTDOWN_MASK) {
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_type, 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 = &iucv_sk(sk)->send_skb_q;
1751         struct sk_buff *list_skb;
1752         unsigned long flags;
1753
1754         bh_lock_sock(sk);
1755
1756         spin_lock_irqsave(&list->lock, flags);
1757         skb_queue_walk(list, list_skb) {
1758                 if (msg->tag == IUCV_SKB_CB(list_skb)->tag) {
1759                         this = list_skb;
1760                         break;
1761                 }
1762         }
1763         if (this)
1764                 __skb_unlink(this, list);
1765         spin_unlock_irqrestore(&list->lock, flags);
1766
1767         if (this) {
1768                 kfree_skb(this);
1769                 /* wake up any process waiting for sending */
1770                 iucv_sock_wake_msglim(sk);
1771         }
1772
1773         if (sk->sk_state == IUCV_CLOSING) {
1774                 if (skb_queue_empty(&iucv_sk(sk)->send_skb_q)) {
1775                         sk->sk_state = IUCV_CLOSED;
1776                         sk->sk_state_change(sk);
1777                 }
1778         }
1779         bh_unlock_sock(sk);
1780
1781 }
1782
1783 static void iucv_callback_connrej(struct iucv_path *path, u8 ipuser[16])
1784 {
1785         struct sock *sk = path->private;
1786
1787         if (sk->sk_state == IUCV_CLOSED)
1788                 return;
1789
1790         bh_lock_sock(sk);
1791         iucv_sever_path(sk, 1);
1792         sk->sk_state = IUCV_DISCONN;
1793
1794         sk->sk_state_change(sk);
1795         bh_unlock_sock(sk);
1796 }
1797
1798 /* called if the other communication side shuts down its RECV direction;
1799  * in turn, the callback sets SEND_SHUTDOWN to disable sending of data.
1800  */
1801 static void iucv_callback_shutdown(struct iucv_path *path, u8 ipuser[16])
1802 {
1803         struct sock *sk = path->private;
1804
1805         bh_lock_sock(sk);
1806         if (sk->sk_state != IUCV_CLOSED) {
1807                 sk->sk_shutdown |= SEND_SHUTDOWN;
1808                 sk->sk_state_change(sk);
1809         }
1810         bh_unlock_sock(sk);
1811 }
1812
1813 /***************** HiperSockets transport callbacks ********************/
1814 static void afiucv_swap_src_dest(struct sk_buff *skb)
1815 {
1816         struct af_iucv_trans_hdr *trans_hdr = iucv_trans_hdr(skb);
1817         char tmpID[8];
1818         char tmpName[8];
1819
1820         ASCEBC(trans_hdr->destUserID, sizeof(trans_hdr->destUserID));
1821         ASCEBC(trans_hdr->destAppName, sizeof(trans_hdr->destAppName));
1822         ASCEBC(trans_hdr->srcUserID, sizeof(trans_hdr->srcUserID));
1823         ASCEBC(trans_hdr->srcAppName, sizeof(trans_hdr->srcAppName));
1824         memcpy(tmpID, trans_hdr->srcUserID, 8);
1825         memcpy(tmpName, trans_hdr->srcAppName, 8);
1826         memcpy(trans_hdr->srcUserID, trans_hdr->destUserID, 8);
1827         memcpy(trans_hdr->srcAppName, trans_hdr->destAppName, 8);
1828         memcpy(trans_hdr->destUserID, tmpID, 8);
1829         memcpy(trans_hdr->destAppName, tmpName, 8);
1830         skb_push(skb, ETH_HLEN);
1831         memset(skb->data, 0, ETH_HLEN);
1832 }
1833
1834 /**
1835  * afiucv_hs_callback_syn - react on received SYN
1836  **/
1837 static int afiucv_hs_callback_syn(struct sock *sk, struct sk_buff *skb)
1838 {
1839         struct af_iucv_trans_hdr *trans_hdr = iucv_trans_hdr(skb);
1840         struct sock *nsk;
1841         struct iucv_sock *iucv, *niucv;
1842         int err;
1843
1844         iucv = iucv_sk(sk);
1845         if (!iucv) {
1846                 /* no sock - connection refused */
1847                 afiucv_swap_src_dest(skb);
1848                 trans_hdr->flags = AF_IUCV_FLAG_SYN | AF_IUCV_FLAG_FIN;
1849                 err = dev_queue_xmit(skb);
1850                 goto out;
1851         }
1852
1853         nsk = iucv_sock_alloc(NULL, sk->sk_type, GFP_ATOMIC, 0);
1854         bh_lock_sock(sk);
1855         if ((sk->sk_state != IUCV_LISTEN) ||
1856             sk_acceptq_is_full(sk) ||
1857             !nsk) {
1858                 /* error on server socket - connection refused */
1859                 afiucv_swap_src_dest(skb);
1860                 trans_hdr->flags = AF_IUCV_FLAG_SYN | AF_IUCV_FLAG_FIN;
1861                 err = dev_queue_xmit(skb);
1862                 iucv_sock_kill(nsk);
1863                 bh_unlock_sock(sk);
1864                 goto out;
1865         }
1866
1867         niucv = iucv_sk(nsk);
1868         iucv_sock_init(nsk, sk);
1869         niucv->transport = AF_IUCV_TRANS_HIPER;
1870         niucv->msglimit = iucv->msglimit;
1871         if (!trans_hdr->window)
1872                 niucv->msglimit_peer = IUCV_HIPER_MSGLIM_DEFAULT;
1873         else
1874                 niucv->msglimit_peer = trans_hdr->window;
1875         memcpy(niucv->dst_name, trans_hdr->srcAppName, 8);
1876         memcpy(niucv->dst_user_id, trans_hdr->srcUserID, 8);
1877         memcpy(niucv->src_name, iucv->src_name, 8);
1878         memcpy(niucv->src_user_id, iucv->src_user_id, 8);
1879         nsk->sk_bound_dev_if = sk->sk_bound_dev_if;
1880         niucv->hs_dev = iucv->hs_dev;
1881         dev_hold(niucv->hs_dev);
1882         afiucv_swap_src_dest(skb);
1883         trans_hdr->flags = AF_IUCV_FLAG_SYN | AF_IUCV_FLAG_ACK;
1884         trans_hdr->window = niucv->msglimit;
1885         /* if receiver acks the xmit connection is established */
1886         err = dev_queue_xmit(skb);
1887         if (!err) {
1888                 iucv_accept_enqueue(sk, nsk);
1889                 nsk->sk_state = IUCV_CONNECTED;
1890                 sk->sk_data_ready(sk);
1891         } else
1892                 iucv_sock_kill(nsk);
1893         bh_unlock_sock(sk);
1894
1895 out:
1896         return NET_RX_SUCCESS;
1897 }
1898
1899 /**
1900  * afiucv_hs_callback_synack() - react on received SYN-ACK
1901  **/
1902 static int afiucv_hs_callback_synack(struct sock *sk, struct sk_buff *skb)
1903 {
1904         struct iucv_sock *iucv = iucv_sk(sk);
1905
1906         if (!iucv)
1907                 goto out;
1908         if (sk->sk_state != IUCV_BOUND)
1909                 goto out;
1910         bh_lock_sock(sk);
1911         iucv->msglimit_peer = iucv_trans_hdr(skb)->window;
1912         sk->sk_state = IUCV_CONNECTED;
1913         sk->sk_state_change(sk);
1914         bh_unlock_sock(sk);
1915 out:
1916         kfree_skb(skb);
1917         return NET_RX_SUCCESS;
1918 }
1919
1920 /**
1921  * afiucv_hs_callback_synfin() - react on received SYN_FIN
1922  **/
1923 static int afiucv_hs_callback_synfin(struct sock *sk, struct sk_buff *skb)
1924 {
1925         struct iucv_sock *iucv = iucv_sk(sk);
1926
1927         if (!iucv)
1928                 goto out;
1929         if (sk->sk_state != IUCV_BOUND)
1930                 goto out;
1931         bh_lock_sock(sk);
1932         sk->sk_state = IUCV_DISCONN;
1933         sk->sk_state_change(sk);
1934         bh_unlock_sock(sk);
1935 out:
1936         kfree_skb(skb);
1937         return NET_RX_SUCCESS;
1938 }
1939
1940 /**
1941  * afiucv_hs_callback_fin() - react on received FIN
1942  **/
1943 static int afiucv_hs_callback_fin(struct sock *sk, struct sk_buff *skb)
1944 {
1945         struct iucv_sock *iucv = iucv_sk(sk);
1946
1947         /* other end of connection closed */
1948         if (!iucv)
1949                 goto out;
1950         bh_lock_sock(sk);
1951         if (sk->sk_state == IUCV_CONNECTED) {
1952                 sk->sk_state = IUCV_DISCONN;
1953                 sk->sk_state_change(sk);
1954         }
1955         bh_unlock_sock(sk);
1956 out:
1957         kfree_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                 WARN_ONCE(1, "AF_IUCV failed to receive skb, len=%u", skb->len);
2039                 kfree_skb(skb);
2040                 return NET_RX_SUCCESS;
2041         }
2042
2043         trans_hdr = iucv_trans_hdr(skb);
2044         EBCASC(trans_hdr->destAppName, sizeof(trans_hdr->destAppName));
2045         EBCASC(trans_hdr->destUserID, sizeof(trans_hdr->destUserID));
2046         EBCASC(trans_hdr->srcAppName, sizeof(trans_hdr->srcAppName));
2047         EBCASC(trans_hdr->srcUserID, sizeof(trans_hdr->srcUserID));
2048         memset(nullstring, 0, sizeof(nullstring));
2049         iucv = NULL;
2050         sk = NULL;
2051         read_lock(&iucv_sk_list.lock);
2052         sk_for_each(sk, &iucv_sk_list.head) {
2053                 if (trans_hdr->flags == AF_IUCV_FLAG_SYN) {
2054                         if ((!memcmp(&iucv_sk(sk)->src_name,
2055                                      trans_hdr->destAppName, 8)) &&
2056                             (!memcmp(&iucv_sk(sk)->src_user_id,
2057                                      trans_hdr->destUserID, 8)) &&
2058                             (!memcmp(&iucv_sk(sk)->dst_name, nullstring, 8)) &&
2059                             (!memcmp(&iucv_sk(sk)->dst_user_id,
2060                                      nullstring, 8))) {
2061                                 iucv = iucv_sk(sk);
2062                                 break;
2063                         }
2064                 } else {
2065                         if ((!memcmp(&iucv_sk(sk)->src_name,
2066                                      trans_hdr->destAppName, 8)) &&
2067                             (!memcmp(&iucv_sk(sk)->src_user_id,
2068                                      trans_hdr->destUserID, 8)) &&
2069                             (!memcmp(&iucv_sk(sk)->dst_name,
2070                                      trans_hdr->srcAppName, 8)) &&
2071                             (!memcmp(&iucv_sk(sk)->dst_user_id,
2072                                      trans_hdr->srcUserID, 8))) {
2073                                 iucv = iucv_sk(sk);
2074                                 break;
2075                         }
2076                 }
2077         }
2078         read_unlock(&iucv_sk_list.lock);
2079         if (!iucv)
2080                 sk = NULL;
2081
2082         /* no sock
2083         how should we send with no sock
2084         1) send without sock no send rc checking?
2085         2) introduce default sock to handle this cases
2086
2087          SYN -> send SYN|ACK in good case, send SYN|FIN in bad case
2088          data -> send FIN
2089          SYN|ACK, SYN|FIN, FIN -> no action? */
2090
2091         switch (trans_hdr->flags) {
2092         case AF_IUCV_FLAG_SYN:
2093                 /* connect request */
2094                 err = afiucv_hs_callback_syn(sk, skb);
2095                 break;
2096         case (AF_IUCV_FLAG_SYN | AF_IUCV_FLAG_ACK):
2097                 /* connect request confirmed */
2098                 err = afiucv_hs_callback_synack(sk, skb);
2099                 break;
2100         case (AF_IUCV_FLAG_SYN | AF_IUCV_FLAG_FIN):
2101                 /* connect request refused */
2102                 err = afiucv_hs_callback_synfin(sk, skb);
2103                 break;
2104         case (AF_IUCV_FLAG_FIN):
2105                 /* close request */
2106                 err = afiucv_hs_callback_fin(sk, skb);
2107                 break;
2108         case (AF_IUCV_FLAG_WIN):
2109                 err = afiucv_hs_callback_win(sk, skb);
2110                 if (skb->len == sizeof(struct af_iucv_trans_hdr)) {
2111                         kfree_skb(skb);
2112                         break;
2113                 }
2114                 fallthrough;    /* and receive non-zero length data */
2115         case (AF_IUCV_FLAG_SHT):
2116                 /* shutdown request */
2117                 fallthrough;    /* and receive zero length data */
2118         case 0:
2119                 /* plain data frame */
2120                 IUCV_SKB_CB(skb)->class = trans_hdr->iucv_hdr.class;
2121                 err = afiucv_hs_callback_rx(sk, skb);
2122                 break;
2123         default:
2124                 kfree_skb(skb);
2125         }
2126
2127         return err;
2128 }
2129
2130 /**
2131  * afiucv_hs_callback_txnotify() - handle send notifcations from HiperSockets
2132  *                                 transport
2133  **/
2134 static void afiucv_hs_callback_txnotify(struct sk_buff *skb,
2135                                         enum iucv_tx_notify n)
2136 {
2137         struct sock *isk = skb->sk;
2138         struct sock *sk = NULL;
2139         struct iucv_sock *iucv = NULL;
2140         struct sk_buff_head *list;
2141         struct sk_buff *list_skb;
2142         struct sk_buff *nskb;
2143         unsigned long flags;
2144
2145         read_lock_irqsave(&iucv_sk_list.lock, flags);
2146         sk_for_each(sk, &iucv_sk_list.head)
2147                 if (sk == isk) {
2148                         iucv = iucv_sk(sk);
2149                         break;
2150                 }
2151         read_unlock_irqrestore(&iucv_sk_list.lock, flags);
2152
2153         if (!iucv || sock_flag(sk, SOCK_ZAPPED))
2154                 return;
2155
2156         list = &iucv->send_skb_q;
2157         spin_lock_irqsave(&list->lock, flags);
2158         skb_queue_walk_safe(list, list_skb, nskb) {
2159                 if (skb_shinfo(list_skb) == skb_shinfo(skb)) {
2160                         switch (n) {
2161                         case TX_NOTIFY_OK:
2162                                 __skb_unlink(list_skb, list);
2163                                 kfree_skb(list_skb);
2164                                 iucv_sock_wake_msglim(sk);
2165                                 break;
2166                         case TX_NOTIFY_PENDING:
2167                                 atomic_inc(&iucv->pendings);
2168                                 break;
2169                         case TX_NOTIFY_DELAYED_OK:
2170                                 __skb_unlink(list_skb, list);
2171                                 atomic_dec(&iucv->pendings);
2172                                 if (atomic_read(&iucv->pendings) <= 0)
2173                                         iucv_sock_wake_msglim(sk);
2174                                 kfree_skb(list_skb);
2175                                 break;
2176                         case TX_NOTIFY_UNREACHABLE:
2177                         case TX_NOTIFY_DELAYED_UNREACHABLE:
2178                         case TX_NOTIFY_TPQFULL: /* not yet used */
2179                         case TX_NOTIFY_GENERALERROR:
2180                         case TX_NOTIFY_DELAYED_GENERALERROR:
2181                                 __skb_unlink(list_skb, list);
2182                                 kfree_skb(list_skb);
2183                                 if (sk->sk_state == IUCV_CONNECTED) {
2184                                         sk->sk_state = IUCV_DISCONN;
2185                                         sk->sk_state_change(sk);
2186                                 }
2187                                 break;
2188                         }
2189                         break;
2190                 }
2191         }
2192         spin_unlock_irqrestore(&list->lock, flags);
2193
2194         if (sk->sk_state == IUCV_CLOSING) {
2195                 if (skb_queue_empty(&iucv_sk(sk)->send_skb_q)) {
2196                         sk->sk_state = IUCV_CLOSED;
2197                         sk->sk_state_change(sk);
2198                 }
2199         }
2200
2201 }
2202
2203 /*
2204  * afiucv_netdev_event: handle netdev notifier chain events
2205  */
2206 static int afiucv_netdev_event(struct notifier_block *this,
2207                                unsigned long event, void *ptr)
2208 {
2209         struct net_device *event_dev = netdev_notifier_info_to_dev(ptr);
2210         struct sock *sk;
2211         struct iucv_sock *iucv;
2212
2213         switch (event) {
2214         case NETDEV_REBOOT:
2215         case NETDEV_GOING_DOWN:
2216                 sk_for_each(sk, &iucv_sk_list.head) {
2217                         iucv = iucv_sk(sk);
2218                         if ((iucv->hs_dev == event_dev) &&
2219                             (sk->sk_state == IUCV_CONNECTED)) {
2220                                 if (event == NETDEV_GOING_DOWN)
2221                                         iucv_send_ctrl(sk, AF_IUCV_FLAG_FIN);
2222                                 sk->sk_state = IUCV_DISCONN;
2223                                 sk->sk_state_change(sk);
2224                         }
2225                 }
2226                 break;
2227         case NETDEV_DOWN:
2228         case NETDEV_UNREGISTER:
2229         default:
2230                 break;
2231         }
2232         return NOTIFY_DONE;
2233 }
2234
2235 static struct notifier_block afiucv_netdev_notifier = {
2236         .notifier_call = afiucv_netdev_event,
2237 };
2238
2239 static const struct proto_ops iucv_sock_ops = {
2240         .family         = PF_IUCV,
2241         .owner          = THIS_MODULE,
2242         .release        = iucv_sock_release,
2243         .bind           = iucv_sock_bind,
2244         .connect        = iucv_sock_connect,
2245         .listen         = iucv_sock_listen,
2246         .accept         = iucv_sock_accept,
2247         .getname        = iucv_sock_getname,
2248         .sendmsg        = iucv_sock_sendmsg,
2249         .recvmsg        = iucv_sock_recvmsg,
2250         .poll           = iucv_sock_poll,
2251         .ioctl          = sock_no_ioctl,
2252         .mmap           = sock_no_mmap,
2253         .socketpair     = sock_no_socketpair,
2254         .shutdown       = iucv_sock_shutdown,
2255         .setsockopt     = iucv_sock_setsockopt,
2256         .getsockopt     = iucv_sock_getsockopt,
2257 };
2258
2259 static int iucv_sock_create(struct net *net, struct socket *sock, int protocol,
2260                             int kern)
2261 {
2262         struct sock *sk;
2263
2264         if (protocol && protocol != PF_IUCV)
2265                 return -EPROTONOSUPPORT;
2266
2267         sock->state = SS_UNCONNECTED;
2268
2269         switch (sock->type) {
2270         case SOCK_STREAM:
2271         case SOCK_SEQPACKET:
2272                 /* currently, proto ops can handle both sk types */
2273                 sock->ops = &iucv_sock_ops;
2274                 break;
2275         default:
2276                 return -ESOCKTNOSUPPORT;
2277         }
2278
2279         sk = iucv_sock_alloc(sock, protocol, GFP_KERNEL, kern);
2280         if (!sk)
2281                 return -ENOMEM;
2282
2283         iucv_sock_init(sk, NULL);
2284
2285         return 0;
2286 }
2287
2288 static const struct net_proto_family iucv_sock_family_ops = {
2289         .family = AF_IUCV,
2290         .owner  = THIS_MODULE,
2291         .create = iucv_sock_create,
2292 };
2293
2294 static struct packet_type iucv_packet_type = {
2295         .type = cpu_to_be16(ETH_P_AF_IUCV),
2296         .func = afiucv_hs_rcv,
2297 };
2298
2299 static int afiucv_iucv_init(void)
2300 {
2301         return pr_iucv->iucv_register(&af_iucv_handler, 0);
2302 }
2303
2304 static void afiucv_iucv_exit(void)
2305 {
2306         pr_iucv->iucv_unregister(&af_iucv_handler, 0);
2307 }
2308
2309 static int __init afiucv_init(void)
2310 {
2311         int err;
2312
2313         if (MACHINE_IS_VM) {
2314                 cpcmd("QUERY USERID", iucv_userid, sizeof(iucv_userid), &err);
2315                 if (unlikely(err)) {
2316                         WARN_ON(err);
2317                         err = -EPROTONOSUPPORT;
2318                         goto out;
2319                 }
2320
2321                 pr_iucv = try_then_request_module(symbol_get(iucv_if), "iucv");
2322                 if (!pr_iucv) {
2323                         printk(KERN_WARNING "iucv_if lookup failed\n");
2324                         memset(&iucv_userid, 0, sizeof(iucv_userid));
2325                 }
2326         } else {
2327                 memset(&iucv_userid, 0, sizeof(iucv_userid));
2328                 pr_iucv = NULL;
2329         }
2330
2331         err = proto_register(&iucv_proto, 0);
2332         if (err)
2333                 goto out;
2334         err = sock_register(&iucv_sock_family_ops);
2335         if (err)
2336                 goto out_proto;
2337
2338         if (pr_iucv) {
2339                 err = afiucv_iucv_init();
2340                 if (err)
2341                         goto out_sock;
2342         }
2343
2344         err = register_netdevice_notifier(&afiucv_netdev_notifier);
2345         if (err)
2346                 goto out_notifier;
2347
2348         dev_add_pack(&iucv_packet_type);
2349         return 0;
2350
2351 out_notifier:
2352         if (pr_iucv)
2353                 afiucv_iucv_exit();
2354 out_sock:
2355         sock_unregister(PF_IUCV);
2356 out_proto:
2357         proto_unregister(&iucv_proto);
2358 out:
2359         if (pr_iucv)
2360                 symbol_put(iucv_if);
2361         return err;
2362 }
2363
2364 static void __exit afiucv_exit(void)
2365 {
2366         if (pr_iucv) {
2367                 afiucv_iucv_exit();
2368                 symbol_put(iucv_if);
2369         }
2370
2371         unregister_netdevice_notifier(&afiucv_netdev_notifier);
2372         dev_remove_pack(&iucv_packet_type);
2373         sock_unregister(PF_IUCV);
2374         proto_unregister(&iucv_proto);
2375 }
2376
2377 module_init(afiucv_init);
2378 module_exit(afiucv_exit);
2379
2380 MODULE_AUTHOR("Jennifer Hunt <jenhunt@us.ibm.com>");
2381 MODULE_DESCRIPTION("IUCV Sockets ver " VERSION);
2382 MODULE_VERSION(VERSION);
2383 MODULE_LICENSE("GPL");
2384 MODULE_ALIAS_NETPROTO(PF_IUCV);