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/module.h>
  17 #include <linux/netdevice.h>
  18 #include <linux/types.h>
  19 #include <linux/list.h>
  20 #include <linux/errno.h>
  21 #include <linux/kernel.h>
  22 #include <linux/sched/signal.h>
  23 #include <linux/slab.h>
  24 #include <linux/skbuff.h>
  25 #include <linux/init.h>
  26 #include <linux/poll.h>
  27 #include <linux/security.h>
  28 #include <net/sock.h>
  29 #include <asm/ebcdic.h>
  30 #include <asm/cpcmd.h>
  31 #include <linux/kmod.h>
  32
  33 #include <net/iucv/af_iucv.h>
  34
  35 #define VERSION "1.2"
  36
  37 static char iucv_userid[80];
  38
  39 static const struct proto_ops iucv_sock_ops;
  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
  49 /* special AF_IUCV IPRM messages */
  50 static const u8 iprm_shutdown[8] =
  51         {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01};
  52
  53 #define TRGCLS_SIZE     sizeof_field(struct iucv_message, class)
  54
  55 #define __iucv_sock_wait(sk, condition, timeo, ret)                     \
  56 do {                                                                    \
  57         DEFINE_WAIT(__wait);                                            \
  58         long __timeo = timeo;                                           \
  59         ret = 0;                                                        \
  60         prepare_to_wait(sk_sleep(sk), &__wait, TASK_INTERRUPTIBLE);     \
  61         while (!(condition)) {                                          \
  62                 if (!__timeo) {                                         \
  63                         ret = -EAGAIN;                                  \
  64                         break;                                          \
  65                 }                                                       \
  66                 if (signal_pending(current)) {                          \
  67                         ret = sock_intr_errno(__timeo);                 \
  68                         break;                                          \
  69                 }                                                       \
  70                 release_sock(sk);                                       \
  71                 __timeo = schedule_timeout(__timeo);                    \
  72                 lock_sock(sk);                                          \
  73                 ret = sock_error(sk);                                   \
  74                 if (ret)                                                \
  75                         break;                                          \
  76         }                                                               \
  77         finish_wait(sk_sleep(sk), &__wait);                             \
  78 } while (0)
  79
  80 #define iucv_sock_wait(sk, condition, timeo)                            \
  81 ({                                                                      \
  82         int __ret = 0;                                                  \
  83         if (!(condition))                                               \
  84                 __iucv_sock_wait(sk, condition, timeo, __ret);          \
  85         __ret;                                                          \
  86 })
  87
  88 static void iucv_sock_kill(struct sock *sk);
  89 static void iucv_sock_close(struct sock *sk);
  90 static void iucv_sever_path(struct sock *, int);
  91
  92 static int afiucv_hs_rcv(struct sk_buff *skb, struct net_device *dev,
  93         struct packet_type *pt, struct net_device *orig_dev);
  94 static int afiucv_hs_send(struct iucv_message *imsg, struct sock *sock,
  95                    struct sk_buff *skb, u8 flags);
  96 static void afiucv_hs_callback_txnotify(struct sk_buff *, enum iucv_tx_notify);
  97
  98 /* Call Back functions */
  99 static void iucv_callback_rx(struct iucv_path *, struct iucv_message *);
 100 static void iucv_callback_txdone(struct iucv_path *, struct iucv_message *);
 101 static void iucv_callback_connack(struct iucv_path *, u8 *);
 102 static int iucv_callback_connreq(struct iucv_path *, u8 *, u8 *);
 103 static void iucv_callback_connrej(struct iucv_path *, u8 *);
 104 static void iucv_callback_shutdown(struct iucv_path *, u8 *);
 105
 106 static struct iucv_sock_list iucv_sk_list = {
 107         .lock = __RW_LOCK_UNLOCKED(iucv_sk_list.lock),
 108         .autobind_name = ATOMIC_INIT(0)
 109 };
 110
 111 static struct iucv_handler af_iucv_handler = {
 112         .path_pending     = iucv_callback_connreq,
 113         .path_complete    = iucv_callback_connack,
 114         .path_severed     = iucv_callback_connrej,
 115         .message_pending  = iucv_callback_rx,
 116         .message_complete = iucv_callback_txdone,
 117         .path_quiesced    = iucv_callback_shutdown,
 118 };
 119
 120 static inline void high_nmcpy(unsigned char *dst, char *src)
 121 {
 122        memcpy(dst, src, 8);
 123 }
 124
 125 static inline void low_nmcpy(unsigned char *dst, char *src)
 126 {
 127        memcpy(&dst[8], src, 8);
 128 }
 129
 130 static int afiucv_pm_prepare(struct device *dev)
 131 {
 132 #ifdef CONFIG_PM_DEBUG
 133         printk(KERN_WARNING "afiucv_pm_prepare\n");
 134 #endif
 135         return 0;
 136 }
 137
 138 static void afiucv_pm_complete(struct device *dev)
 139 {
 140 #ifdef CONFIG_PM_DEBUG
 141         printk(KERN_WARNING "afiucv_pm_complete\n");
 142 #endif
 143 }
 144
 145 /**
 146  * afiucv_pm_freeze() - Freeze PM callback
 147  * @dev:        AFIUCV dummy device
 148  *
 149  * Sever all established IUCV communication pathes
 150  */
 151 static int afiucv_pm_freeze(struct device *dev)
 152 {
 153         struct iucv_sock *iucv;
 154         struct sock *sk;
 155
 156 #ifdef CONFIG_PM_DEBUG
 157         printk(KERN_WARNING "afiucv_pm_freeze\n");
 158 #endif
 159         read_lock(&iucv_sk_list.lock);
 160         sk_for_each(sk, &iucv_sk_list.head) {
 161                 iucv = iucv_sk(sk);
 162                 switch (sk->sk_state) {
 163                 case IUCV_DISCONN:
 164                 case IUCV_CLOSING:
 165                 case IUCV_CONNECTED:
 166                         iucv_sever_path(sk, 0);
 167                         break;
 168                 case IUCV_OPEN:
 169                 case IUCV_BOUND:
 170                 case IUCV_LISTEN:
 171                 case IUCV_CLOSED:
 172                 default:
 173                         break;
 174                 }
 175                 skb_queue_purge(&iucv->send_skb_q);
 176                 skb_queue_purge(&iucv->backlog_skb_q);
 177         }
 178         read_unlock(&iucv_sk_list.lock);
 179         return 0;
 180 }
 181
 182 /**
 183  * afiucv_pm_restore_thaw() - Thaw and restore PM callback
 184  * @dev:        AFIUCV dummy device
 185  *
 186  * socket clean up after freeze
 187  */
 188 static int afiucv_pm_restore_thaw(struct device *dev)
 189 {
 190         struct sock *sk;
 191
 192 #ifdef CONFIG_PM_DEBUG
 193         printk(KERN_WARNING "afiucv_pm_restore_thaw\n");
 194 #endif
 195         read_lock(&iucv_sk_list.lock);
 196         sk_for_each(sk, &iucv_sk_list.head) {
 197                 switch (sk->sk_state) {
 198                 case IUCV_CONNECTED:
 199                         sk->sk_err = EPIPE;
 200                         sk->sk_state = IUCV_DISCONN;
 201                         sk->sk_state_change(sk);
 202                         break;
 203                 case IUCV_DISCONN:
 204                 case IUCV_CLOSING:
 205                 case IUCV_LISTEN:
 206                 case IUCV_BOUND:
 207                 case IUCV_OPEN:
 208                 default:
 209                         break;
 210                 }
 211         }
 212         read_unlock(&iucv_sk_list.lock);
 213         return 0;
 214 }
 215
 216 static const struct dev_pm_ops afiucv_pm_ops = {
 217         .prepare = afiucv_pm_prepare,
 218         .complete = afiucv_pm_complete,
 219         .freeze = afiucv_pm_freeze,
 220         .thaw = afiucv_pm_restore_thaw,
 221         .restore = afiucv_pm_restore_thaw,
 222 };
 223
 224 static struct device_driver af_iucv_driver = {
 225         .owner = THIS_MODULE,
 226         .name = "afiucv",
 227         .bus  = NULL,
 228         .pm   = &afiucv_pm_ops,
 229 };
 230
 231 /* dummy device used as trigger for PM functions */
 232 static struct device *af_iucv_dev;
 233
 234 /**
 235  * iucv_msg_length() - Returns the length of an iucv message.
 236  * @msg:        Pointer to struct iucv_message, MUST NOT be NULL
 237  *
 238  * The function returns the length of the specified iucv message @msg of data
 239  * stored in a buffer and of data stored in the parameter list (PRMDATA).
 240  *
 241  * For IUCV_IPRMDATA, AF_IUCV uses the following convention to transport socket
 242  * data:
 243  *      PRMDATA[0..6]   socket data (max 7 bytes);
 244  *      PRMDATA[7]      socket data length value (len is 0xff - PRMDATA[7])
 245  *
 246  * The socket data length is computed by subtracting the socket data length
 247  * value from 0xFF.
 248  * If the socket data len is greater 7, then PRMDATA can be used for special
 249  * notifications (see iucv_sock_shutdown); and further,
 250  * if the socket data len is > 7, the function returns 8.
 251  *
 252  * Use this function to allocate socket buffers to store iucv message data.
 253  */
 254 static inline size_t iucv_msg_length(struct iucv_message *msg)
 255 {
 256         size_t datalen;
 257
 258         if (msg->flags & IUCV_IPRMDATA) {
 259                 datalen = 0xff - msg->rmmsg[7];
 260                 return (datalen < 8) ? datalen : 8;
 261         }
 262         return msg->length;
 263 }
 264
 265 /**
 266  * iucv_sock_in_state() - check for specific states
 267  * @sk:         sock structure
 268  * @state:      first iucv sk state
 269  * @state:      second iucv sk state
 270  *
 271  * Returns true if the socket in either in the first or second state.
 272  */
 273 static int iucv_sock_in_state(struct sock *sk, int state, int state2)
 274 {
 275         return (sk->sk_state == state || sk->sk_state == state2);
 276 }
 277
 278 /**
 279  * iucv_below_msglim() - function to check if messages can be sent
 280  * @sk:         sock structure
 281  *
 282  * Returns true if the send queue length is lower than the message limit.
 283  * Always returns true if the socket is not connected (no iucv path for
 284  * checking the message limit).
 285  */
 286 static inline int iucv_below_msglim(struct sock *sk)
 287 {
 288         struct iucv_sock *iucv = iucv_sk(sk);
 289
 290         if (sk->sk_state != IUCV_CONNECTED)
 291                 return 1;
 292         if (iucv->transport == AF_IUCV_TRANS_IUCV)
 293                 return (skb_queue_len(&iucv->send_skb_q) < iucv->path->msglim);
 294         else
 295                 return ((atomic_read(&iucv->msg_sent) < iucv->msglimit_peer) &&
 296                         (atomic_read(&iucv->pendings) <= 0));
 297 }
 298
 299 /**
 300  * iucv_sock_wake_msglim() - Wake up thread waiting on msg limit
 301  */
 302 static void iucv_sock_wake_msglim(struct sock *sk)
 303 {
 304         struct socket_wq *wq;
 305
 306         rcu_read_lock();
 307         wq = rcu_dereference(sk->sk_wq);
 308         if (skwq_has_sleeper(wq))
 309                 wake_up_interruptible_all(&wq->wait);
 310         sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
 311         rcu_read_unlock();
 312 }
 313
 314 /**
 315  * afiucv_hs_send() - send a message through HiperSockets transport
 316  */
 317 static int afiucv_hs_send(struct iucv_message *imsg, struct sock *sock,
 318                    struct sk_buff *skb, u8 flags)
 319 {
 320         struct iucv_sock *iucv = iucv_sk(sock);
 321         struct af_iucv_trans_hdr *phs_hdr;
 322         struct sk_buff *nskb;
 323         int err, confirm_recv = 0;
 324
 325         phs_hdr = skb_push(skb, sizeof(*phs_hdr));
 326         memset(phs_hdr, 0, sizeof(*phs_hdr));
 327         skb_reset_network_header(skb);
 328
 329         phs_hdr->magic = ETH_P_AF_IUCV;
 330         phs_hdr->version = 1;
 331         phs_hdr->flags = flags;
 332         if (flags == AF_IUCV_FLAG_SYN)
 333                 phs_hdr->window = iucv->msglimit;
 334         else if ((flags == AF_IUCV_FLAG_WIN) || !flags) {
 335                 confirm_recv = atomic_read(&iucv->msg_recv);
 336                 phs_hdr->window = confirm_recv;
 337                 if (confirm_recv)
 338                         phs_hdr->flags = phs_hdr->flags | AF_IUCV_FLAG_WIN;
 339         }
 340         memcpy(phs_hdr->destUserID, iucv->dst_user_id, 8);
 341         memcpy(phs_hdr->destAppName, iucv->dst_name, 8);
 342         memcpy(phs_hdr->srcUserID, iucv->src_user_id, 8);
 343         memcpy(phs_hdr->srcAppName, iucv->src_name, 8);
 344         ASCEBC(phs_hdr->destUserID, sizeof(phs_hdr->destUserID));
 345         ASCEBC(phs_hdr->destAppName, sizeof(phs_hdr->destAppName));
 346         ASCEBC(phs_hdr->srcUserID, sizeof(phs_hdr->srcUserID));
 347         ASCEBC(phs_hdr->srcAppName, sizeof(phs_hdr->srcAppName));
 348         if (imsg)
 349                 memcpy(&phs_hdr->iucv_hdr, imsg, sizeof(struct iucv_message));
 350
 351         skb->dev = iucv->hs_dev;
 352         if (!skb->dev) {
 353                 err = -ENODEV;
 354                 goto err_free;
 355         }
 356
 357         dev_hard_header(skb, skb->dev, ETH_P_AF_IUCV, NULL, NULL, skb->len);
 358
 359         if (!(skb->dev->flags & IFF_UP) || !netif_carrier_ok(skb->dev)) {
 360                 err = -ENETDOWN;
 361                 goto err_free;
 362         }
 363         if (skb->len > skb->dev->mtu) {
 364                 if (sock->sk_type == SOCK_SEQPACKET) {
 365                         err = -EMSGSIZE;
 366                         goto err_free;
 367                 }
 368                 skb_trim(skb, skb->dev->mtu);
 369         }
 370         skb->protocol = cpu_to_be16(ETH_P_AF_IUCV);
 371
 372         __skb_header_release(skb);
 373         nskb = skb_clone(skb, GFP_ATOMIC);
 374         if (!nskb) {
 375                 err = -ENOMEM;
 376                 goto err_free;
 377         }
 378
 379         skb_queue_tail(&iucv->send_skb_q, nskb);
 380         err = dev_queue_xmit(skb);
 381         if (net_xmit_eval(err)) {
 382                 skb_unlink(nskb, &iucv->send_skb_q);
 383                 kfree_skb(nskb);
 384         } else {
 385                 atomic_sub(confirm_recv, &iucv->msg_recv);
 386                 WARN_ON(atomic_read(&iucv->msg_recv) < 0);
 387         }
 388         return net_xmit_eval(err);
 389
 390 err_free:
 391         kfree_skb(skb);
 392         return err;
 393 }
 394
 395 static struct sock *__iucv_get_sock_by_name(char *nm)
 396 {
 397         struct sock *sk;
 398
 399         sk_for_each(sk, &iucv_sk_list.head)
 400                 if (!memcmp(&iucv_sk(sk)->src_name, nm, 8))
 401                         return sk;
 402
 403         return NULL;
 404 }
 405
 406 static void iucv_sock_destruct(struct sock *sk)
 407 {
 408         skb_queue_purge(&sk->sk_receive_queue);
 409         skb_queue_purge(&sk->sk_error_queue);
 410
 411         sk_mem_reclaim(sk);
 412
 413         if (!sock_flag(sk, SOCK_DEAD)) {
 414                 pr_err("Attempt to release alive iucv socket %p\n", sk);
 415                 return;
 416         }
 417
 418         WARN_ON(atomic_read(&sk->sk_rmem_alloc));
 419         WARN_ON(refcount_read(&sk->sk_wmem_alloc));
 420         WARN_ON(sk->sk_wmem_queued);
 421         WARN_ON(sk->sk_forward_alloc);
 422 }
 423
 424 /* Cleanup Listen */
 425 static void iucv_sock_cleanup_listen(struct sock *parent)
 426 {
 427         struct sock *sk;
 428
 429         /* Close non-accepted connections */
 430         while ((sk = iucv_accept_dequeue(parent, NULL))) {
 431                 iucv_sock_close(sk);
 432                 iucv_sock_kill(sk);
 433         }
 434
 435         parent->sk_state = IUCV_CLOSED;
 436 }
 437
 438 /* Kill socket (only if zapped and orphaned) */
 439 static void iucv_sock_kill(struct sock *sk)
 440 {
 441         if (!sock_flag(sk, SOCK_ZAPPED) || sk->sk_socket)
 442                 return;
 443
 444         iucv_sock_unlink(&iucv_sk_list, sk);
 445         sock_set_flag(sk, SOCK_DEAD);
 446         sock_put(sk);
 447 }
 448
 449 /* Terminate an IUCV path */
 450 static void iucv_sever_path(struct sock *sk, int with_user_data)
 451 {
 452         unsigned char user_data[16];
 453         struct iucv_sock *iucv = iucv_sk(sk);
 454         struct iucv_path *path = iucv->path;
 455
 456         if (iucv->path) {
 457                 iucv->path = NULL;
 458                 if (with_user_data) {
 459                         low_nmcpy(user_data, iucv->src_name);
 460                         high_nmcpy(user_data, iucv->dst_name);
 461                         ASCEBC(user_data, sizeof(user_data));
 462                         pr_iucv->path_sever(path, user_data);
 463                 } else
 464                         pr_iucv->path_sever(path, NULL);
 465                 iucv_path_free(path);
 466         }
 467 }
 468
 469 /* Send controlling flags through an IUCV socket for HIPER transport */
 470 static int iucv_send_ctrl(struct sock *sk, u8 flags)
 471 {
 472         struct iucv_sock *iucv = iucv_sk(sk);
 473         int err = 0;
 474         int blen;
 475         struct sk_buff *skb;
 476         u8 shutdown = 0;
 477
 478         blen = sizeof(struct af_iucv_trans_hdr) +
 479                LL_RESERVED_SPACE(iucv->hs_dev);
 480         if (sk->sk_shutdown & SEND_SHUTDOWN) {
 481                 /* controlling flags should be sent anyway */
 482                 shutdown = sk->sk_shutdown;
 483                 sk->sk_shutdown &= RCV_SHUTDOWN;
 484         }
 485         skb = sock_alloc_send_skb(sk, blen, 1, &err);
 486         if (skb) {
 487                 skb_reserve(skb, blen);
 488                 err = afiucv_hs_send(NULL, sk, skb, flags);
 489         }
 490         if (shutdown)
 491                 sk->sk_shutdown = shutdown;
 492         return err;
 493 }
 494
 495 /* Close an IUCV socket */
 496 static void iucv_sock_close(struct sock *sk)
 497 {
 498         struct iucv_sock *iucv = iucv_sk(sk);
 499         unsigned long timeo;
 500         int err = 0;
 501
 502         lock_sock(sk);
 503
 504         switch (sk->sk_state) {
 505         case IUCV_LISTEN:
 506                 iucv_sock_cleanup_listen(sk);
 507                 break;
 508
 509         case IUCV_CONNECTED:
 510                 if (iucv->transport == AF_IUCV_TRANS_HIPER) {
 511                         err = iucv_send_ctrl(sk, AF_IUCV_FLAG_FIN);
 512                         sk->sk_state = IUCV_DISCONN;
 513                         sk->sk_state_change(sk);
 514                 }
 515                 /* fall through */
 516
 517         case IUCV_DISCONN:
 518                 sk->sk_state = IUCV_CLOSING;
 519                 sk->sk_state_change(sk);
 520
 521                 if (!err && !skb_queue_empty(&iucv->send_skb_q)) {
 522                         if (sock_flag(sk, SOCK_LINGER) && sk->sk_lingertime)
 523                                 timeo = sk->sk_lingertime;
 524                         else
 525                                 timeo = IUCV_DISCONN_TIMEOUT;
 526                         iucv_sock_wait(sk,
 527                                         iucv_sock_in_state(sk, IUCV_CLOSED, 0),
 528                                         timeo);
 529                 }
 530                 /* fall through */
 531
 532         case IUCV_CLOSING:
 533                 sk->sk_state = IUCV_CLOSED;
 534                 sk->sk_state_change(sk);
 535
 536                 sk->sk_err = ECONNRESET;
 537                 sk->sk_state_change(sk);
 538
 539                 skb_queue_purge(&iucv->send_skb_q);
 540                 skb_queue_purge(&iucv->backlog_skb_q);
 541                 /* fall through */
 542
 543         default:
 544                 iucv_sever_path(sk, 1);
 545         }
 546
 547         if (iucv->hs_dev) {
 548                 dev_put(iucv->hs_dev);
 549                 iucv->hs_dev = NULL;
 550                 sk->sk_bound_dev_if = 0;
 551         }
 552
 553         /* mark socket for deletion by iucv_sock_kill() */
 554         sock_set_flag(sk, SOCK_ZAPPED);
 555
 556         release_sock(sk);
 557 }
 558
 559 static void iucv_sock_init(struct sock *sk, struct sock *parent)
 560 {
 561         if (parent) {
 562                 sk->sk_type = parent->sk_type;
 563                 security_sk_clone(parent, sk);
 564         }
 565 }
 566
 567 static struct sock *iucv_sock_alloc(struct socket *sock, int proto, gfp_t prio, int kern)
 568 {
 569         struct sock *sk;
 570         struct iucv_sock *iucv;
 571
 572         sk = sk_alloc(&init_net, PF_IUCV, prio, &iucv_proto, kern);
 573         if (!sk)
 574                 return NULL;
 575         iucv = iucv_sk(sk);
 576
 577         sock_init_data(sock, sk);
 578         INIT_LIST_HEAD(&iucv->accept_q);
 579         spin_lock_init(&iucv->accept_q_lock);
 580         skb_queue_head_init(&iucv->send_skb_q);
 581         INIT_LIST_HEAD(&iucv->message_q.list);
 582         spin_lock_init(&iucv->message_q.lock);
 583         skb_queue_head_init(&iucv->backlog_skb_q);
 584         iucv->send_tag = 0;
 585         atomic_set(&iucv->pendings, 0);
 586         iucv->flags = 0;
 587         iucv->msglimit = 0;
 588         atomic_set(&iucv->msg_sent, 0);
 589         atomic_set(&iucv->msg_recv, 0);
 590         iucv->path = NULL;
 591         iucv->sk_txnotify = afiucv_hs_callback_txnotify;
 592         memset(&iucv->src_user_id , 0, 32);
 593         if (pr_iucv)
 594                 iucv->transport = AF_IUCV_TRANS_IUCV;
 595         else
 596                 iucv->transport = AF_IUCV_TRANS_HIPER;
 597
 598         sk->sk_destruct = iucv_sock_destruct;
 599         sk->sk_sndtimeo = IUCV_CONN_TIMEOUT;
 600
 601         sock_reset_flag(sk, SOCK_ZAPPED);
 602
 603         sk->sk_protocol = proto;
 604         sk->sk_state    = IUCV_OPEN;
 605
 606         iucv_sock_link(&iucv_sk_list, sk);
 607         return sk;
 608 }
 609
 610 /* Create an IUCV socket */
 611 static int iucv_sock_create(struct net *net, struct socket *sock, int protocol,
 612                             int kern)
 613 {
 614         struct sock *sk;
 615
 616         if (protocol && protocol != PF_IUCV)
 617                 return -EPROTONOSUPPORT;
 618
 619         sock->state = SS_UNCONNECTED;
 620
 621         switch (sock->type) {
 622         case SOCK_STREAM:
 623                 sock->ops = &iucv_sock_ops;
 624                 break;
 625         case SOCK_SEQPACKET:
 626                 /* currently, proto ops can handle both sk types */
 627                 sock->ops = &iucv_sock_ops;
 628                 break;
 629         default:
 630                 return -ESOCKTNOSUPPORT;
 631         }
 632
 633         sk = iucv_sock_alloc(sock, protocol, GFP_KERNEL, kern);
 634         if (!sk)
 635                 return -ENOMEM;
 636
 637         iucv_sock_init(sk, NULL);
 638
 639         return 0;
 640 }
 641
 642 void iucv_sock_link(struct iucv_sock_list *l, struct sock *sk)
 643 {
 644         write_lock_bh(&l->lock);
 645         sk_add_node(sk, &l->head);
 646         write_unlock_bh(&l->lock);
 647 }
 648
 649 void iucv_sock_unlink(struct iucv_sock_list *l, struct sock *sk)
 650 {
 651         write_lock_bh(&l->lock);
 652         sk_del_node_init(sk);
 653         write_unlock_bh(&l->lock);
 654 }
 655
 656 void iucv_accept_enqueue(struct sock *parent, struct sock *sk)
 657 {
 658         unsigned long flags;
 659         struct iucv_sock *par = iucv_sk(parent);
 660
 661         sock_hold(sk);
 662         spin_lock_irqsave(&par->accept_q_lock, flags);
 663         list_add_tail(&iucv_sk(sk)->accept_q, &par->accept_q);
 664         spin_unlock_irqrestore(&par->accept_q_lock, flags);
 665         iucv_sk(sk)->parent = parent;
 666         sk_acceptq_added(parent);
 667 }
 668
 669 void iucv_accept_unlink(struct sock *sk)
 670 {
 671         unsigned long flags;
 672         struct iucv_sock *par = iucv_sk(iucv_sk(sk)->parent);
 673
 674         spin_lock_irqsave(&par->accept_q_lock, flags);
 675         list_del_init(&iucv_sk(sk)->accept_q);
 676         spin_unlock_irqrestore(&par->accept_q_lock, flags);
 677         sk_acceptq_removed(iucv_sk(sk)->parent);
 678         iucv_sk(sk)->parent = NULL;
 679         sock_put(sk);
 680 }
 681
 682 struct sock *iucv_accept_dequeue(struct sock *parent, struct socket *newsock)
 683 {
 684         struct iucv_sock *isk, *n;
 685         struct sock *sk;
 686
 687         list_for_each_entry_safe(isk, n, &iucv_sk(parent)->accept_q, accept_q) {
 688                 sk = (struct sock *) isk;
 689                 lock_sock(sk);
 690
 691                 if (sk->sk_state == IUCV_CLOSED) {
 692                         iucv_accept_unlink(sk);
 693                         release_sock(sk);
 694                         continue;
 695                 }
 696
 697                 if (sk->sk_state == IUCV_CONNECTED ||
 698                     sk->sk_state == IUCV_DISCONN ||
 699                     !newsock) {
 700                         iucv_accept_unlink(sk);
 701                         if (newsock)
 702                                 sock_graft(sk, newsock);
 703
 704                         release_sock(sk);
 705                         return sk;
 706                 }
 707
 708                 release_sock(sk);
 709         }
 710         return NULL;
 711 }
 712
 713 static void __iucv_auto_name(struct iucv_sock *iucv)
 714 {
 715         char name[12];
 716
 717         sprintf(name, "%08x", atomic_inc_return(&iucv_sk_list.autobind_name));
 718         while (__iucv_get_sock_by_name(name)) {
 719                 sprintf(name, "%08x",
 720                         atomic_inc_return(&iucv_sk_list.autobind_name));
 721         }
 722         memcpy(iucv->src_name, name, 8);
 723 }
 724
 725 /* Bind an unbound socket */
 726 static int iucv_sock_bind(struct socket *sock, struct sockaddr *addr,
 727                           int addr_len)
 728 {
 729         struct sockaddr_iucv *sa = (struct sockaddr_iucv *) addr;
 730         struct sock *sk = sock->sk;
 731         struct iucv_sock *iucv;
 732         int err = 0;
 733         struct net_device *dev;
 734         char uid[9];
 735
 736         /* Verify the input sockaddr */
 737         if (addr_len < sizeof(struct sockaddr_iucv) ||
 738             addr->sa_family != AF_IUCV)
 739                 return -EINVAL;
 740
 741         lock_sock(sk);
 742         if (sk->sk_state != IUCV_OPEN) {
 743                 err = -EBADFD;
 744                 goto done;
 745         }
 746
 747         write_lock_bh(&iucv_sk_list.lock);
 748
 749         iucv = iucv_sk(sk);
 750         if (__iucv_get_sock_by_name(sa->siucv_name)) {
 751                 err = -EADDRINUSE;
 752                 goto done_unlock;
 753         }
 754         if (iucv->path)
 755                 goto done_unlock;
 756
 757         /* Bind the socket */
 758         if (pr_iucv)
 759                 if (!memcmp(sa->siucv_user_id, iucv_userid, 8))
 760                         goto vm_bind; /* VM IUCV transport */
 761
 762         /* try hiper transport */
 763         memcpy(uid, sa->siucv_user_id, sizeof(uid));
 764         ASCEBC(uid, 8);
 765         rcu_read_lock();
 766         for_each_netdev_rcu(&init_net, dev) {
 767                 if (!memcmp(dev->perm_addr, uid, 8)) {
 768                         memcpy(iucv->src_user_id, sa->siucv_user_id, 8);
 769                         /* Check for unitialized siucv_name */
 770                         if (strncmp(sa->siucv_name, "        ", 8) == 0)
 771                                 __iucv_auto_name(iucv);
 772                         else
 773                                 memcpy(iucv->src_name, sa->siucv_name, 8);
 774                         sk->sk_bound_dev_if = dev->ifindex;
 775                         iucv->hs_dev = dev;
 776                         dev_hold(dev);
 777                         sk->sk_state = IUCV_BOUND;
 778                         iucv->transport = AF_IUCV_TRANS_HIPER;
 779                         if (!iucv->msglimit)
 780                                 iucv->msglimit = IUCV_HIPER_MSGLIM_DEFAULT;
 781                         rcu_read_unlock();
 782                         goto done_unlock;
 783                 }
 784         }
 785         rcu_read_unlock();
 786 vm_bind:
 787         if (pr_iucv) {
 788                 /* use local userid for backward compat */
 789                 memcpy(iucv->src_name, sa->siucv_name, 8);
 790                 memcpy(iucv->src_user_id, iucv_userid, 8);
 791                 sk->sk_state = IUCV_BOUND;
 792                 iucv->transport = AF_IUCV_TRANS_IUCV;
 793                 sk->sk_allocation |= GFP_DMA;
 794                 if (!iucv->msglimit)
 795                         iucv->msglimit = IUCV_QUEUELEN_DEFAULT;
 796                 goto done_unlock;
 797         }
 798         /* found no dev to bind */
 799         err = -ENODEV;
 800 done_unlock:
 801         /* Release the socket list lock */
 802         write_unlock_bh(&iucv_sk_list.lock);
 803 done:
 804         release_sock(sk);
 805         return err;
 806 }
 807
 808 /* Automatically bind an unbound socket */
 809 static int iucv_sock_autobind(struct sock *sk)
 810 {
 811         struct iucv_sock *iucv = iucv_sk(sk);
 812         int err = 0;
 813
 814         if (unlikely(!pr_iucv))
 815                 return -EPROTO;
 816
 817         memcpy(iucv->src_user_id, iucv_userid, 8);
 818         iucv->transport = AF_IUCV_TRANS_IUCV;
 819         sk->sk_allocation |= GFP_DMA;
 820
 821         write_lock_bh(&iucv_sk_list.lock);
 822         __iucv_auto_name(iucv);
 823         write_unlock_bh(&iucv_sk_list.lock);
 824
 825         if (!iucv->msglimit)
 826                 iucv->msglimit = IUCV_QUEUELEN_DEFAULT;
 827
 828         return err;
 829 }
 830
 831 static int afiucv_path_connect(struct socket *sock, struct sockaddr *addr)
 832 {
 833         struct sockaddr_iucv *sa = (struct sockaddr_iucv *) addr;
 834         struct sock *sk = sock->sk;
 835         struct iucv_sock *iucv = iucv_sk(sk);
 836         unsigned char user_data[16];
 837         int err;
 838
 839         high_nmcpy(user_data, sa->siucv_name);
 840         low_nmcpy(user_data, iucv->src_name);
 841         ASCEBC(user_data, sizeof(user_data));
 842
 843         /* Create path. */
 844         iucv->path = iucv_path_alloc(iucv->msglimit,
 845                                      IUCV_IPRMDATA, GFP_KERNEL);
 846         if (!iucv->path) {
 847                 err = -ENOMEM;
 848                 goto done;
 849         }
 850         err = pr_iucv->path_connect(iucv->path, &af_iucv_handler,
 851                                     sa->siucv_user_id, NULL, user_data,
 852                                     sk);
 853         if (err) {
 854                 iucv_path_free(iucv->path);
 855                 iucv->path = NULL;
 856                 switch (err) {
 857                 case 0x0b:      /* Target communicator is not logged on */
 858                         err = -ENETUNREACH;
 859                         break;
 860                 case 0x0d:      /* Max connections for this guest exceeded */
 861                 case 0x0e:      /* Max connections for target guest exceeded */
 862                         err = -EAGAIN;
 863                         break;
 864                 case 0x0f:      /* Missing IUCV authorization */
 865                         err = -EACCES;
 866                         break;
 867                 default:
 868                         err = -ECONNREFUSED;
 869                         break;
 870                 }
 871         }
 872 done:
 873         return err;
 874 }
 875
 876 /* Connect an unconnected socket */
 877 static int iucv_sock_connect(struct socket *sock, struct sockaddr *addr,
 878                              int alen, int flags)
 879 {
 880         struct sockaddr_iucv *sa = (struct sockaddr_iucv *) addr;
 881         struct sock *sk = sock->sk;
 882         struct iucv_sock *iucv = iucv_sk(sk);
 883         int err;
 884
 885         if (alen < sizeof(struct sockaddr_iucv) || addr->sa_family != AF_IUCV)
 886                 return -EINVAL;
 887
 888         if (sk->sk_state != IUCV_OPEN && sk->sk_state != IUCV_BOUND)
 889                 return -EBADFD;
 890
 891         if (sk->sk_state == IUCV_OPEN &&
 892             iucv->transport == AF_IUCV_TRANS_HIPER)
 893                 return -EBADFD; /* explicit bind required */
 894
 895         if (sk->sk_type != SOCK_STREAM && sk->sk_type != SOCK_SEQPACKET)
 896                 return -EINVAL;
 897
 898         if (sk->sk_state == IUCV_OPEN) {
 899                 err = iucv_sock_autobind(sk);
 900                 if (unlikely(err))
 901                         return err;
 902         }
 903
 904         lock_sock(sk);
 905
 906         /* Set the destination information */
 907         memcpy(iucv->dst_user_id, sa->siucv_user_id, 8);
 908         memcpy(iucv->dst_name, sa->siucv_name, 8);
 909
 910         if (iucv->transport == AF_IUCV_TRANS_HIPER)
 911                 err = iucv_send_ctrl(sock->sk, AF_IUCV_FLAG_SYN);
 912         else
 913                 err = afiucv_path_connect(sock, addr);
 914         if (err)
 915                 goto done;
 916
 917         if (sk->sk_state != IUCV_CONNECTED)
 918                 err = iucv_sock_wait(sk, iucv_sock_in_state(sk, IUCV_CONNECTED,
 919                                                             IUCV_DISCONN),
 920                                      sock_sndtimeo(sk, flags & O_NONBLOCK));
 921
 922         if (sk->sk_state == IUCV_DISCONN || sk->sk_state == IUCV_CLOSED)
 923                 err = -ECONNREFUSED;
 924
 925         if (err && iucv->transport == AF_IUCV_TRANS_IUCV)
 926                 iucv_sever_path(sk, 0);
 927
 928 done:
 929         release_sock(sk);
 930         return err;
 931 }
 932
 933 /* Move a socket into listening state. */
 934 static int iucv_sock_listen(struct socket *sock, int backlog)
 935 {
 936         struct sock *sk = sock->sk;
 937         int err;
 938
 939         lock_sock(sk);
 940
 941         err = -EINVAL;
 942         if (sk->sk_state != IUCV_BOUND)
 943                 goto done;
 944
 945         if (sock->type != SOCK_STREAM && sock->type != SOCK_SEQPACKET)
 946                 goto done;
 947
 948         sk->sk_max_ack_backlog = backlog;
 949         sk->sk_ack_backlog = 0;
 950         sk->sk_state = IUCV_LISTEN;
 951         err = 0;
 952
 953 done:
 954         release_sock(sk);
 955         return err;
 956 }
 957
 958 /* Accept a pending connection */
 959 static int iucv_sock_accept(struct socket *sock, struct socket *newsock,
 960                             int flags, bool kern)
 961 {
 962         DECLARE_WAITQUEUE(wait, current);
 963         struct sock *sk = sock->sk, *nsk;
 964         long timeo;
 965         int err = 0;
 966
 967         lock_sock_nested(sk, SINGLE_DEPTH_NESTING);
 968
 969         if (sk->sk_state != IUCV_LISTEN) {
 970                 err = -EBADFD;
 971                 goto done;
 972         }
 973
 974         timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);
 975
 976         /* Wait for an incoming connection */
 977         add_wait_queue_exclusive(sk_sleep(sk), &wait);
 978         while (!(nsk = iucv_accept_dequeue(sk, newsock))) {
 979                 set_current_state(TASK_INTERRUPTIBLE);
 980                 if (!timeo) {
 981                         err = -EAGAIN;
 982                         break;
 983                 }
 984
 985                 release_sock(sk);
 986                 timeo = schedule_timeout(timeo);
 987                 lock_sock_nested(sk, SINGLE_DEPTH_NESTING);
 988
 989                 if (sk->sk_state != IUCV_LISTEN) {
 990                         err = -EBADFD;
 991                         break;
 992                 }
 993
 994                 if (signal_pending(current)) {
 995                         err = sock_intr_errno(timeo);
 996                         break;
 997                 }
 998         }
 999
1000         set_current_state(TASK_RUNNING);
1001         remove_wait_queue(sk_sleep(sk), &wait);
1002
1003         if (err)
1004                 goto done;
1005
1006         newsock->state = SS_CONNECTED;
1007
1008 done:
1009         release_sock(sk);
1010         return err;
1011 }
1012
1013 static int iucv_sock_getname(struct socket *sock, struct sockaddr *addr,
1014                              int peer)
1015 {
1016         struct sockaddr_iucv *siucv = (struct sockaddr_iucv *) addr;
1017         struct sock *sk = sock->sk;
1018         struct iucv_sock *iucv = iucv_sk(sk);
1019
1020         addr->sa_family = AF_IUCV;
1021
1022         if (peer) {
1023                 memcpy(siucv->siucv_user_id, iucv->dst_user_id, 8);
1024                 memcpy(siucv->siucv_name, iucv->dst_name, 8);
1025         } else {
1026                 memcpy(siucv->siucv_user_id, iucv->src_user_id, 8);
1027                 memcpy(siucv->siucv_name, iucv->src_name, 8);
1028         }
1029         memset(&siucv->siucv_port, 0, sizeof(siucv->siucv_port));
1030         memset(&siucv->siucv_addr, 0, sizeof(siucv->siucv_addr));
1031         memset(&siucv->siucv_nodeid, 0, sizeof(siucv->siucv_nodeid));
1032
1033         return sizeof(struct sockaddr_iucv);
1034 }
1035
1036 /**
1037  * iucv_send_iprm() - Send socket data in parameter list of an iucv message.
1038  * @path:       IUCV path
1039  * @msg:        Pointer to a struct iucv_message
1040  * @skb:        The socket data to send, skb->len MUST BE <= 7
1041  *
1042  * Send the socket data in the parameter list in the iucv message
1043  * (IUCV_IPRMDATA). The socket data is stored at index 0 to 6 in the parameter
1044  * list and the socket data len at index 7 (last byte).
1045  * See also iucv_msg_length().
1046  *
1047  * Returns the error code from the iucv_message_send() call.
1048  */
1049 static int iucv_send_iprm(struct iucv_path *path, struct iucv_message *msg,
1050                           struct sk_buff *skb)
1051 {
1052         u8 prmdata[8];
1053
1054         memcpy(prmdata, (void *) skb->data, skb->len);
1055         prmdata[7] = 0xff - (u8) skb->len;
1056         return pr_iucv->message_send(path, msg, IUCV_IPRMDATA, 0,
1057                                  (void *) prmdata, 8);
1058 }
1059
1060 static int iucv_sock_sendmsg(struct socket *sock, struct msghdr *msg,
1061                              size_t len)
1062 {
1063         struct sock *sk = sock->sk;
1064         struct iucv_sock *iucv = iucv_sk(sk);
1065         size_t headroom = 0;
1066         size_t linear;
1067         struct sk_buff *skb;
1068         struct iucv_message txmsg = {0};
1069         struct cmsghdr *cmsg;
1070         int cmsg_done;
1071         long timeo;
1072         char user_id[9];
1073         char appl_id[9];
1074         int err;
1075         int noblock = msg->msg_flags & MSG_DONTWAIT;
1076
1077         err = sock_error(sk);
1078         if (err)
1079                 return err;
1080
1081         if (msg->msg_flags & MSG_OOB)
1082                 return -EOPNOTSUPP;
1083
1084         /* SOCK_SEQPACKET: we do not support segmented records */
1085         if (sk->sk_type == SOCK_SEQPACKET && !(msg->msg_flags & MSG_EOR))
1086                 return -EOPNOTSUPP;
1087
1088         lock_sock(sk);
1089
1090         if (sk->sk_shutdown & SEND_SHUTDOWN) {
1091                 err = -EPIPE;
1092                 goto out;
1093         }
1094
1095         /* Return if the socket is not in connected state */
1096         if (sk->sk_state != IUCV_CONNECTED) {
1097                 err = -ENOTCONN;
1098                 goto out;
1099         }
1100
1101         /* initialize defaults */
1102         cmsg_done   = 0;        /* check for duplicate headers */
1103         txmsg.class = 0;
1104
1105         /* iterate over control messages */
1106         for_each_cmsghdr(cmsg, msg) {
1107                 if (!CMSG_OK(msg, cmsg)) {
1108                         err = -EINVAL;
1109                         goto out;
1110                 }
1111
1112                 if (cmsg->cmsg_level != SOL_IUCV)
1113                         continue;
1114
1115                 if (cmsg->cmsg_type & cmsg_done) {
1116                         err = -EINVAL;
1117                         goto out;
1118                 }
1119                 cmsg_done |= cmsg->cmsg_type;
1120
1121                 switch (cmsg->cmsg_type) {
1122                 case SCM_IUCV_TRGCLS:
1123                         if (cmsg->cmsg_len != CMSG_LEN(TRGCLS_SIZE)) {
1124                                 err = -EINVAL;
1125                                 goto out;
1126                         }
1127
1128                         /* set iucv message target class */
1129                         memcpy(&txmsg.class,
1130                                 (void *) CMSG_DATA(cmsg), TRGCLS_SIZE);
1131
1132                         break;
1133
1134                 default:
1135                         err = -EINVAL;
1136                         goto out;
1137                 }
1138         }
1139
1140         /* allocate one skb for each iucv message:
1141          * this is fine for SOCK_SEQPACKET (unless we want to support
1142          * segmented records using the MSG_EOR flag), but
1143          * for SOCK_STREAM we might want to improve it in future */
1144         if (iucv->transport == AF_IUCV_TRANS_HIPER) {
1145                 headroom = sizeof(struct af_iucv_trans_hdr) +
1146                            LL_RESERVED_SPACE(iucv->hs_dev);
1147                 linear = len;
1148         } else {
1149                 if (len < PAGE_SIZE) {
1150                         linear = len;
1151                 } else {
1152                         /* In nonlinear "classic" iucv skb,
1153                          * reserve space for iucv_array
1154                          */
1155                         headroom = sizeof(struct iucv_array) *
1156                                    (MAX_SKB_FRAGS + 1);
1157                         linear = PAGE_SIZE - headroom;
1158                 }
1159         }
1160         skb = sock_alloc_send_pskb(sk, headroom + linear, len - linear,
1161                                    noblock, &err, 0);
1162         if (!skb)
1163                 goto out;
1164         if (headroom)
1165                 skb_reserve(skb, headroom);
1166         skb_put(skb, linear);
1167         skb->len = len;
1168         skb->data_len = len - linear;
1169         err = skb_copy_datagram_from_iter(skb, 0, &msg->msg_iter, len);
1170         if (err)
1171                 goto fail;
1172
1173         /* wait if outstanding messages for iucv path has reached */
1174         timeo = sock_sndtimeo(sk, noblock);
1175         err = iucv_sock_wait(sk, iucv_below_msglim(sk), timeo);
1176         if (err)
1177                 goto fail;
1178
1179         /* return -ECONNRESET if the socket is no longer connected */
1180         if (sk->sk_state != IUCV_CONNECTED) {
1181                 err = -ECONNRESET;
1182                 goto fail;
1183         }
1184
1185         /* increment and save iucv message tag for msg_completion cbk */
1186         txmsg.tag = iucv->send_tag++;
1187         IUCV_SKB_CB(skb)->tag = txmsg.tag;
1188
1189         if (iucv->transport == AF_IUCV_TRANS_HIPER) {
1190                 atomic_inc(&iucv->msg_sent);
1191                 err = afiucv_hs_send(&txmsg, sk, skb, 0);
1192                 if (err) {
1193                         atomic_dec(&iucv->msg_sent);
1194                         goto out;
1195                 }
1196         } else { /* Classic VM IUCV transport */
1197                 skb_queue_tail(&iucv->send_skb_q, skb);
1198
1199                 if (((iucv->path->flags & IUCV_IPRMDATA) & iucv->flags) &&
1200                     skb->len <= 7) {
1201                         err = iucv_send_iprm(iucv->path, &txmsg, skb);
1202
1203                         /* on success: there is no message_complete callback */
1204                         /* for an IPRMDATA msg; remove skb from send queue   */
1205                         if (err == 0) {
1206                                 skb_unlink(skb, &iucv->send_skb_q);
1207                                 kfree_skb(skb);
1208                         }
1209
1210                         /* this error should never happen since the     */
1211                         /* IUCV_IPRMDATA path flag is set... sever path */
1212                         if (err == 0x15) {
1213                                 pr_iucv->path_sever(iucv->path, NULL);
1214                                 skb_unlink(skb, &iucv->send_skb_q);
1215                                 err = -EPIPE;
1216                                 goto fail;
1217                         }
1218                 } else if (skb_is_nonlinear(skb)) {
1219                         struct iucv_array *iba = (struct iucv_array *)skb->head;
1220                         int i;
1221
1222                         /* skip iucv_array lying in the headroom */
1223                         iba[0].address = (u32)(addr_t)skb->data;
1224                         iba[0].length = (u32)skb_headlen(skb);
1225                         for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
1226                                 skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
1227
1228                                 iba[i + 1].address =
1229                                         (u32)(addr_t)skb_frag_address(frag);
1230                                 iba[i + 1].length = (u32)skb_frag_size(frag);
1231                         }
1232                         err = pr_iucv->message_send(iucv->path, &txmsg,
1233                                                     IUCV_IPBUFLST, 0,
1234                                                     (void *)iba, skb->len);
1235                 } else { /* non-IPRM Linear skb */
1236                         err = pr_iucv->message_send(iucv->path, &txmsg,
1237                                         0, 0, (void *)skb->data, skb->len);
1238                 }
1239                 if (err) {
1240                         if (err == 3) {
1241                                 user_id[8] = 0;
1242                                 memcpy(user_id, iucv->dst_user_id, 8);
1243                                 appl_id[8] = 0;
1244                                 memcpy(appl_id, iucv->dst_name, 8);
1245                                 pr_err(
1246                 "Application %s on z/VM guest %s exceeds message limit\n",
1247                                         appl_id, user_id);
1248                                 err = -EAGAIN;
1249                         } else {
1250                                 err = -EPIPE;
1251                         }
1252                         skb_unlink(skb, &iucv->send_skb_q);
1253                         goto fail;
1254                 }
1255         }
1256
1257         release_sock(sk);
1258         return len;
1259
1260 fail:
1261         kfree_skb(skb);
1262 out:
1263         release_sock(sk);
1264         return err;
1265 }
1266
1267 static struct sk_buff *alloc_iucv_recv_skb(unsigned long len)
1268 {
1269         size_t headroom, linear;
1270         struct sk_buff *skb;
1271         int err;
1272
1273         if (len < PAGE_SIZE) {
1274                 headroom = 0;
1275                 linear = len;
1276         } else {
1277                 headroom = sizeof(struct iucv_array) * (MAX_SKB_FRAGS + 1);
1278                 linear = PAGE_SIZE - headroom;
1279         }
1280         skb = alloc_skb_with_frags(headroom + linear, len - linear,
1281                                    0, &err, GFP_ATOMIC | GFP_DMA);
1282         WARN_ONCE(!skb,
1283                   "alloc of recv iucv skb len=%lu failed with errcode=%d\n",
1284                   len, err);
1285         if (skb) {
1286                 if (headroom)
1287                         skb_reserve(skb, headroom);
1288                 skb_put(skb, linear);
1289                 skb->len = len;
1290                 skb->data_len = len - linear;
1291         }
1292         return skb;
1293 }
1294
1295 /* iucv_process_message() - Receive a single outstanding IUCV message
1296  *
1297  * Locking: must be called with message_q.lock held
1298  */
1299 static void iucv_process_message(struct sock *sk, struct sk_buff *skb,
1300                                  struct iucv_path *path,
1301                                  struct iucv_message *msg)
1302 {
1303         int rc;
1304         unsigned int len;
1305
1306         len = iucv_msg_length(msg);
1307
1308         /* store msg target class in the second 4 bytes of skb ctrl buffer */
1309         /* Note: the first 4 bytes are reserved for msg tag */
1310         IUCV_SKB_CB(skb)->class = msg->class;
1311
1312         /* check for special IPRM messages (e.g. iucv_sock_shutdown) */
1313         if ((msg->flags & IUCV_IPRMDATA) && len > 7) {
1314                 if (memcmp(msg->rmmsg, iprm_shutdown, 8) == 0) {
1315                         skb->data = NULL;
1316                         skb->len = 0;
1317                 }
1318         } else {
1319                 if (skb_is_nonlinear(skb)) {
1320                         struct iucv_array *iba = (struct iucv_array *)skb->head;
1321                         int i;
1322
1323                         iba[0].address = (u32)(addr_t)skb->data;
1324                         iba[0].length = (u32)skb_headlen(skb);
1325                         for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
1326                                 skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
1327
1328                                 iba[i + 1].address =
1329                                         (u32)(addr_t)skb_frag_address(frag);
1330                                 iba[i + 1].length = (u32)skb_frag_size(frag);
1331                         }
1332                         rc = pr_iucv->message_receive(path, msg,
1333                                               IUCV_IPBUFLST,
1334                                               (void *)iba, len, NULL);
1335                 } else {
1336                         rc = pr_iucv->message_receive(path, msg,
1337                                               msg->flags & IUCV_IPRMDATA,
1338                                               skb->data, len, NULL);
1339                 }
1340                 if (rc) {
1341                         kfree_skb(skb);
1342                         return;
1343                 }
1344                 WARN_ON_ONCE(skb->len != len);
1345         }
1346
1347         IUCV_SKB_CB(skb)->offset = 0;
1348         if (sk_filter(sk, skb)) {
1349                 atomic_inc(&sk->sk_drops);      /* skb rejected by filter */
1350                 kfree_skb(skb);
1351                 return;
1352         }
1353         if (__sock_queue_rcv_skb(sk, skb))      /* handle rcv queue full */
1354                 skb_queue_tail(&iucv_sk(sk)->backlog_skb_q, skb);
1355 }
1356
1357 /* iucv_process_message_q() - Process outstanding IUCV messages
1358  *
1359  * Locking: must be called with message_q.lock held
1360  */
1361 static void iucv_process_message_q(struct sock *sk)
1362 {
1363         struct iucv_sock *iucv = iucv_sk(sk);
1364         struct sk_buff *skb;
1365         struct sock_msg_q *p, *n;
1366
1367         list_for_each_entry_safe(p, n, &iucv->message_q.list, list) {
1368                 skb = alloc_iucv_recv_skb(iucv_msg_length(&p->msg));
1369                 if (!skb)
1370                         break;
1371                 iucv_process_message(sk, skb, p->path, &p->msg);
1372                 list_del(&p->list);
1373                 kfree(p);
1374                 if (!skb_queue_empty(&iucv->backlog_skb_q))
1375                         break;
1376         }
1377 }
1378
1379 static int iucv_sock_recvmsg(struct socket *sock, struct msghdr *msg,
1380                              size_t len, int flags)
1381 {
1382         int noblock = flags & MSG_DONTWAIT;
1383         struct sock *sk = sock->sk;
1384         struct iucv_sock *iucv = iucv_sk(sk);
1385         unsigned int copied, rlen;
1386         struct sk_buff *skb, *rskb, *cskb;
1387         int err = 0;
1388         u32 offset;
1389
1390         if ((sk->sk_state == IUCV_DISCONN) &&
1391             skb_queue_empty(&iucv->backlog_skb_q) &&
1392             skb_queue_empty(&sk->sk_receive_queue) &&
1393             list_empty(&iucv->message_q.list))
1394                 return 0;
1395
1396         if (flags & (MSG_OOB))
1397                 return -EOPNOTSUPP;
1398
1399         /* receive/dequeue next skb:
1400          * the function understands MSG_PEEK and, thus, does not dequeue skb */
1401         skb = skb_recv_datagram(sk, flags, noblock, &err);
1402         if (!skb) {
1403                 if (sk->sk_shutdown & RCV_SHUTDOWN)
1404                         return 0;
1405                 return err;
1406         }
1407
1408         offset = IUCV_SKB_CB(skb)->offset;
1409         rlen   = skb->len - offset;             /* real length of skb */
1410         copied = min_t(unsigned int, rlen, len);
1411         if (!rlen)
1412                 sk->sk_shutdown = sk->sk_shutdown | RCV_SHUTDOWN;
1413
1414         cskb = skb;
1415         if (skb_copy_datagram_msg(cskb, offset, msg, copied)) {
1416                 if (!(flags & MSG_PEEK))
1417                         skb_queue_head(&sk->sk_receive_queue, skb);
1418                 return -EFAULT;
1419         }
1420
1421         /* SOCK_SEQPACKET: set MSG_TRUNC if recv buf size is too small */
1422         if (sk->sk_type == SOCK_SEQPACKET) {
1423                 if (copied < rlen)
1424                         msg->msg_flags |= MSG_TRUNC;
1425                 /* each iucv message contains a complete record */
1426                 msg->msg_flags |= MSG_EOR;
1427         }
1428
1429         /* create control message to store iucv msg target class:
1430          * get the trgcls from the control buffer of the skb due to
1431          * fragmentation of original iucv message. */
1432         err = put_cmsg(msg, SOL_IUCV, SCM_IUCV_TRGCLS,
1433                        sizeof(IUCV_SKB_CB(skb)->class),
1434                        (void *)&IUCV_SKB_CB(skb)->class);
1435         if (err) {
1436                 if (!(flags & MSG_PEEK))
1437                         skb_queue_head(&sk->sk_receive_queue, skb);
1438                 return err;
1439         }
1440
1441         /* Mark read part of skb as used */
1442         if (!(flags & MSG_PEEK)) {
1443
1444                 /* SOCK_STREAM: re-queue skb if it contains unreceived data */
1445                 if (sk->sk_type == SOCK_STREAM) {
1446                         if (copied < rlen) {
1447                                 IUCV_SKB_CB(skb)->offset = offset + copied;
1448                                 skb_queue_head(&sk->sk_receive_queue, skb);
1449                                 goto done;
1450                         }
1451                 }
1452
1453                 kfree_skb(skb);
1454                 if (iucv->transport == AF_IUCV_TRANS_HIPER) {
1455                         atomic_inc(&iucv->msg_recv);
1456                         if (atomic_read(&iucv->msg_recv) > iucv->msglimit) {
1457                                 WARN_ON(1);
1458                                 iucv_sock_close(sk);
1459                                 return -EFAULT;
1460                         }
1461                 }
1462
1463                 /* Queue backlog skbs */
1464                 spin_lock_bh(&iucv->message_q.lock);
1465                 rskb = skb_dequeue(&iucv->backlog_skb_q);
1466                 while (rskb) {
1467                         IUCV_SKB_CB(rskb)->offset = 0;
1468                         if (__sock_queue_rcv_skb(sk, rskb)) {
1469                                 /* handle rcv queue full */
1470                                 skb_queue_head(&iucv->backlog_skb_q,
1471                                                 rskb);
1472                                 break;
1473                         }
1474                         rskb = skb_dequeue(&iucv->backlog_skb_q);
1475                 }
1476                 if (skb_queue_empty(&iucv->backlog_skb_q)) {
1477                         if (!list_empty(&iucv->message_q.list))
1478                                 iucv_process_message_q(sk);
1479                         if (atomic_read(&iucv->msg_recv) >=
1480                                                         iucv->msglimit / 2) {
1481                                 err = iucv_send_ctrl(sk, AF_IUCV_FLAG_WIN);
1482                                 if (err) {
1483                                         sk->sk_state = IUCV_DISCONN;
1484                                         sk->sk_state_change(sk);
1485                                 }
1486                         }
1487                 }
1488                 spin_unlock_bh(&iucv->message_q.lock);
1489         }
1490
1491 done:
1492         /* SOCK_SEQPACKET: return real length if MSG_TRUNC is set */
1493         if (sk->sk_type == SOCK_SEQPACKET && (flags & MSG_TRUNC))
1494                 copied = rlen;
1495
1496         return copied;
1497 }
1498
1499 static inline __poll_t iucv_accept_poll(struct sock *parent)
1500 {
1501         struct iucv_sock *isk, *n;
1502         struct sock *sk;
1503
1504         list_for_each_entry_safe(isk, n, &iucv_sk(parent)->accept_q, accept_q) {
1505                 sk = (struct sock *) isk;
1506
1507                 if (sk->sk_state == IUCV_CONNECTED)
1508                         return EPOLLIN | EPOLLRDNORM;
1509         }
1510
1511         return 0;
1512 }
1513
1514 __poll_t iucv_sock_poll(struct file *file, struct socket *sock,
1515                             poll_table *wait)
1516 {
1517         struct sock *sk = sock->sk;
1518         __poll_t mask = 0;
1519
1520         sock_poll_wait(file, sock, wait);
1521
1522         if (sk->sk_state == IUCV_LISTEN)
1523                 return iucv_accept_poll(sk);
1524
1525         if (sk->sk_err || !skb_queue_empty(&sk->sk_error_queue))
1526                 mask |= EPOLLERR |
1527                         (sock_flag(sk, SOCK_SELECT_ERR_QUEUE) ? EPOLLPRI : 0);
1528
1529         if (sk->sk_shutdown & RCV_SHUTDOWN)
1530                 mask |= EPOLLRDHUP;
1531
1532         if (sk->sk_shutdown == SHUTDOWN_MASK)
1533                 mask |= EPOLLHUP;
1534
1535         if (!skb_queue_empty(&sk->sk_receive_queue) ||
1536             (sk->sk_shutdown & RCV_SHUTDOWN))
1537                 mask |= EPOLLIN | EPOLLRDNORM;
1538
1539         if (sk->sk_state == IUCV_CLOSED)
1540                 mask |= EPOLLHUP;
1541
1542         if (sk->sk_state == IUCV_DISCONN)
1543                 mask |= EPOLLIN;
1544
1545         if (sock_writeable(sk) && iucv_below_msglim(sk))
1546                 mask |= EPOLLOUT | EPOLLWRNORM | EPOLLWRBAND;
1547         else
1548                 sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
1549
1550         return mask;
1551 }
1552
1553 static int iucv_sock_shutdown(struct socket *sock, int how)
1554 {
1555         struct sock *sk = sock->sk;
1556         struct iucv_sock *iucv = iucv_sk(sk);
1557         struct iucv_message txmsg;
1558         int err = 0;
1559
1560         how++;
1561
1562         if ((how & ~SHUTDOWN_MASK) || !how)
1563                 return -EINVAL;
1564
1565         lock_sock(sk);
1566         switch (sk->sk_state) {
1567         case IUCV_LISTEN:
1568         case IUCV_DISCONN:
1569         case IUCV_CLOSING:
1570         case IUCV_CLOSED:
1571                 err = -ENOTCONN;
1572                 goto fail;
1573         default:
1574                 break;
1575         }
1576
1577         if (how == SEND_SHUTDOWN || how == SHUTDOWN_MASK) {
1578                 if (iucv->transport == AF_IUCV_TRANS_IUCV) {
1579                         txmsg.class = 0;
1580                         txmsg.tag = 0;
1581                         err = pr_iucv->message_send(iucv->path, &txmsg,
1582                                 IUCV_IPRMDATA, 0, (void *) iprm_shutdown, 8);
1583                         if (err) {
1584                                 switch (err) {
1585                                 case 1:
1586                                         err = -ENOTCONN;
1587                                         break;
1588                                 case 2:
1589                                         err = -ECONNRESET;
1590                                         break;
1591                                 default:
1592                                         err = -ENOTCONN;
1593                                         break;
1594                                 }
1595                         }
1596                 } else
1597                         iucv_send_ctrl(sk, AF_IUCV_FLAG_SHT);
1598         }
1599
1600         sk->sk_shutdown |= how;
1601         if (how == RCV_SHUTDOWN || how == SHUTDOWN_MASK) {
1602                 if ((iucv->transport == AF_IUCV_TRANS_IUCV) &&
1603                     iucv->path) {
1604                         err = pr_iucv->path_quiesce(iucv->path, NULL);
1605                         if (err)
1606                                 err = -ENOTCONN;
1607 /*                      skb_queue_purge(&sk->sk_receive_queue); */
1608                 }
1609                 skb_queue_purge(&sk->sk_receive_queue);
1610         }
1611
1612         /* Wake up anyone sleeping in poll */
1613         sk->sk_state_change(sk);
1614
1615 fail:
1616         release_sock(sk);
1617         return err;
1618 }
1619
1620 static int iucv_sock_release(struct socket *sock)
1621 {
1622         struct sock *sk = sock->sk;
1623         int err = 0;
1624
1625         if (!sk)
1626                 return 0;
1627
1628         iucv_sock_close(sk);
1629
1630         sock_orphan(sk);
1631         iucv_sock_kill(sk);
1632         return err;
1633 }
1634
1635 /* getsockopt and setsockopt */
1636 static int iucv_sock_setsockopt(struct socket *sock, int level, int optname,
1637                                 char __user *optval, unsigned int optlen)
1638 {
1639         struct sock *sk = sock->sk;
1640         struct iucv_sock *iucv = iucv_sk(sk);
1641         int val;
1642         int rc;
1643
1644         if (level != SOL_IUCV)
1645                 return -ENOPROTOOPT;
1646
1647         if (optlen < sizeof(int))
1648                 return -EINVAL;
1649
1650         if (get_user(val, (int __user *) optval))
1651                 return -EFAULT;
1652
1653         rc = 0;
1654
1655         lock_sock(sk);
1656         switch (optname) {
1657         case SO_IPRMDATA_MSG:
1658                 if (val)
1659                         iucv->flags |= IUCV_IPRMDATA;
1660                 else
1661                         iucv->flags &= ~IUCV_IPRMDATA;
1662                 break;
1663         case SO_MSGLIMIT:
1664                 switch (sk->sk_state) {
1665                 case IUCV_OPEN:
1666                 case IUCV_BOUND:
1667                         if (val < 1 || val > (u16)(~0))
1668                                 rc = -EINVAL;
1669                         else
1670                                 iucv->msglimit = val;
1671                         break;
1672                 default:
1673                         rc = -EINVAL;
1674                         break;
1675                 }
1676                 break;
1677         default:
1678                 rc = -ENOPROTOOPT;
1679                 break;
1680         }
1681         release_sock(sk);
1682
1683         return rc;
1684 }
1685
1686 static int iucv_sock_getsockopt(struct socket *sock, int level, int optname,
1687                                 char __user *optval, int __user *optlen)
1688 {
1689         struct sock *sk = sock->sk;
1690         struct iucv_sock *iucv = iucv_sk(sk);
1691         unsigned int val;
1692         int len;
1693
1694         if (level != SOL_IUCV)
1695                 return -ENOPROTOOPT;
1696
1697         if (get_user(len, optlen))
1698                 return -EFAULT;
1699
1700         if (len < 0)
1701                 return -EINVAL;
1702
1703         len = min_t(unsigned int, len, sizeof(int));
1704
1705         switch (optname) {
1706         case SO_IPRMDATA_MSG:
1707                 val = (iucv->flags & IUCV_IPRMDATA) ? 1 : 0;
1708                 break;
1709         case SO_MSGLIMIT:
1710                 lock_sock(sk);
1711                 val = (iucv->path != NULL) ? iucv->path->msglim /* connected */
1712                                            : iucv->msglimit;    /* default */
1713                 release_sock(sk);
1714                 break;
1715         case SO_MSGSIZE:
1716                 if (sk->sk_state == IUCV_OPEN)
1717                         return -EBADFD;
1718                 val = (iucv->hs_dev) ? iucv->hs_dev->mtu -
1719                                 sizeof(struct af_iucv_trans_hdr) - ETH_HLEN :
1720                                 0x7fffffff;
1721                 break;
1722         default:
1723                 return -ENOPROTOOPT;
1724         }
1725
1726         if (put_user(len, optlen))
1727                 return -EFAULT;
1728         if (copy_to_user(optval, &val, len))
1729                 return -EFAULT;
1730
1731         return 0;
1732 }
1733
1734
1735 /* Callback wrappers - called from iucv base support */
1736 static int iucv_callback_connreq(struct iucv_path *path,
1737                                  u8 ipvmid[8], u8 ipuser[16])
1738 {
1739         unsigned char user_data[16];
1740         unsigned char nuser_data[16];
1741         unsigned char src_name[8];
1742         struct sock *sk, *nsk;
1743         struct iucv_sock *iucv, *niucv;
1744         int err;
1745
1746         memcpy(src_name, ipuser, 8);
1747         EBCASC(src_name, 8);
1748         /* Find out if this path belongs to af_iucv. */
1749         read_lock(&iucv_sk_list.lock);
1750         iucv = NULL;
1751         sk = NULL;
1752         sk_for_each(sk, &iucv_sk_list.head)
1753                 if (sk->sk_state == IUCV_LISTEN &&
1754                     !memcmp(&iucv_sk(sk)->src_name, src_name, 8)) {
1755                         /*
1756                          * Found a listening socket with
1757                          * src_name == ipuser[0-7].
1758                          */
1759                         iucv = iucv_sk(sk);
1760                         break;
1761                 }
1762         read_unlock(&iucv_sk_list.lock);
1763         if (!iucv)
1764                 /* No socket found, not one of our paths. */
1765                 return -EINVAL;
1766
1767         bh_lock_sock(sk);
1768
1769         /* Check if parent socket is listening */
1770         low_nmcpy(user_data, iucv->src_name);
1771         high_nmcpy(user_data, iucv->dst_name);
1772         ASCEBC(user_data, sizeof(user_data));
1773         if (sk->sk_state != IUCV_LISTEN) {
1774                 err = pr_iucv->path_sever(path, user_data);
1775                 iucv_path_free(path);
1776                 goto fail;
1777         }
1778
1779         /* Check for backlog size */
1780         if (sk_acceptq_is_full(sk)) {
1781                 err = pr_iucv->path_sever(path, user_data);
1782                 iucv_path_free(path);
1783                 goto fail;
1784         }
1785
1786         /* Create the new socket */
1787         nsk = iucv_sock_alloc(NULL, sk->sk_type, GFP_ATOMIC, 0);
1788         if (!nsk) {
1789                 err = pr_iucv->path_sever(path, user_data);
1790                 iucv_path_free(path);
1791                 goto fail;
1792         }
1793
1794         niucv = iucv_sk(nsk);
1795         iucv_sock_init(nsk, sk);
1796         niucv->transport = AF_IUCV_TRANS_IUCV;
1797         nsk->sk_allocation |= GFP_DMA;
1798
1799         /* Set the new iucv_sock */
1800         memcpy(niucv->dst_name, ipuser + 8, 8);
1801         EBCASC(niucv->dst_name, 8);
1802         memcpy(niucv->dst_user_id, ipvmid, 8);
1803         memcpy(niucv->src_name, iucv->src_name, 8);
1804         memcpy(niucv->src_user_id, iucv->src_user_id, 8);
1805         niucv->path = path;
1806
1807         /* Call iucv_accept */
1808         high_nmcpy(nuser_data, ipuser + 8);
1809         memcpy(nuser_data + 8, niucv->src_name, 8);
1810         ASCEBC(nuser_data + 8, 8);
1811
1812         /* set message limit for path based on msglimit of accepting socket */
1813         niucv->msglimit = iucv->msglimit;
1814         path->msglim = iucv->msglimit;
1815         err = pr_iucv->path_accept(path, &af_iucv_handler, nuser_data, nsk);
1816         if (err) {
1817                 iucv_sever_path(nsk, 1);
1818                 iucv_sock_kill(nsk);
1819                 goto fail;
1820         }
1821
1822         iucv_accept_enqueue(sk, nsk);
1823
1824         /* Wake up accept */
1825         nsk->sk_state = IUCV_CONNECTED;
1826         sk->sk_data_ready(sk);
1827         err = 0;
1828 fail:
1829         bh_unlock_sock(sk);
1830         return 0;
1831 }
1832
1833 static void iucv_callback_connack(struct iucv_path *path, u8 ipuser[16])
1834 {
1835         struct sock *sk = path->private;
1836
1837         sk->sk_state = IUCV_CONNECTED;
1838         sk->sk_state_change(sk);
1839 }
1840
1841 static void iucv_callback_rx(struct iucv_path *path, struct iucv_message *msg)
1842 {
1843         struct sock *sk = path->private;
1844         struct iucv_sock *iucv = iucv_sk(sk);
1845         struct sk_buff *skb;
1846         struct sock_msg_q *save_msg;
1847         int len;
1848
1849         if (sk->sk_shutdown & RCV_SHUTDOWN) {
1850                 pr_iucv->message_reject(path, msg);
1851                 return;
1852         }
1853
1854         spin_lock(&iucv->message_q.lock);
1855
1856         if (!list_empty(&iucv->message_q.list) ||
1857             !skb_queue_empty(&iucv->backlog_skb_q))
1858                 goto save_message;
1859
1860         len = atomic_read(&sk->sk_rmem_alloc);
1861         len += SKB_TRUESIZE(iucv_msg_length(msg));
1862         if (len > sk->sk_rcvbuf)
1863                 goto save_message;
1864
1865         skb = alloc_iucv_recv_skb(iucv_msg_length(msg));
1866         if (!skb)
1867                 goto save_message;
1868
1869         iucv_process_message(sk, skb, path, msg);
1870         goto out_unlock;
1871
1872 save_message:
1873         save_msg = kzalloc(sizeof(struct sock_msg_q), GFP_ATOMIC | GFP_DMA);
1874         if (!save_msg)
1875                 goto out_unlock;
1876         save_msg->path = path;
1877         save_msg->msg = *msg;
1878
1879         list_add_tail(&save_msg->list, &iucv->message_q.list);
1880
1881 out_unlock:
1882         spin_unlock(&iucv->message_q.lock);
1883 }
1884
1885 static void iucv_callback_txdone(struct iucv_path *path,
1886                                  struct iucv_message *msg)
1887 {
1888         struct sock *sk = path->private;
1889         struct sk_buff *this = NULL;
1890         struct sk_buff_head *list = &iucv_sk(sk)->send_skb_q;
1891         struct sk_buff *list_skb;
1892         unsigned long flags;
1893
1894         bh_lock_sock(sk);
1895
1896         spin_lock_irqsave(&list->lock, flags);
1897         skb_queue_walk(list, list_skb) {
1898                 if (msg->tag == IUCV_SKB_CB(list_skb)->tag) {
1899                         this = list_skb;
1900                         break;
1901                 }
1902         }
1903         if (this)
1904                 __skb_unlink(this, list);
1905         spin_unlock_irqrestore(&list->lock, flags);
1906
1907         if (this) {
1908                 kfree_skb(this);
1909                 /* wake up any process waiting for sending */
1910                 iucv_sock_wake_msglim(sk);
1911         }
1912
1913         if (sk->sk_state == IUCV_CLOSING) {
1914                 if (skb_queue_empty(&iucv_sk(sk)->send_skb_q)) {
1915                         sk->sk_state = IUCV_CLOSED;
1916                         sk->sk_state_change(sk);
1917                 }
1918         }
1919         bh_unlock_sock(sk);
1920
1921 }
1922
1923 static void iucv_callback_connrej(struct iucv_path *path, u8 ipuser[16])
1924 {
1925         struct sock *sk = path->private;
1926
1927         if (sk->sk_state == IUCV_CLOSED)
1928                 return;
1929
1930         bh_lock_sock(sk);
1931         iucv_sever_path(sk, 1);
1932         sk->sk_state = IUCV_DISCONN;
1933
1934         sk->sk_state_change(sk);
1935         bh_unlock_sock(sk);
1936 }
1937
1938 /* called if the other communication side shuts down its RECV direction;
1939  * in turn, the callback sets SEND_SHUTDOWN to disable sending of data.
1940  */
1941 static void iucv_callback_shutdown(struct iucv_path *path, u8 ipuser[16])
1942 {
1943         struct sock *sk = path->private;
1944
1945         bh_lock_sock(sk);
1946         if (sk->sk_state != IUCV_CLOSED) {
1947                 sk->sk_shutdown |= SEND_SHUTDOWN;
1948                 sk->sk_state_change(sk);
1949         }
1950         bh_unlock_sock(sk);
1951 }
1952
1953 /***************** HiperSockets transport callbacks ********************/
1954 static void afiucv_swap_src_dest(struct sk_buff *skb)
1955 {
1956         struct af_iucv_trans_hdr *trans_hdr = iucv_trans_hdr(skb);
1957         char tmpID[8];
1958         char tmpName[8];
1959
1960         ASCEBC(trans_hdr->destUserID, sizeof(trans_hdr->destUserID));
1961         ASCEBC(trans_hdr->destAppName, sizeof(trans_hdr->destAppName));
1962         ASCEBC(trans_hdr->srcUserID, sizeof(trans_hdr->srcUserID));
1963         ASCEBC(trans_hdr->srcAppName, sizeof(trans_hdr->srcAppName));
1964         memcpy(tmpID, trans_hdr->srcUserID, 8);
1965         memcpy(tmpName, trans_hdr->srcAppName, 8);
1966         memcpy(trans_hdr->srcUserID, trans_hdr->destUserID, 8);
1967         memcpy(trans_hdr->srcAppName, trans_hdr->destAppName, 8);
1968         memcpy(trans_hdr->destUserID, tmpID, 8);
1969         memcpy(trans_hdr->destAppName, tmpName, 8);
1970         skb_push(skb, ETH_HLEN);
1971         memset(skb->data, 0, ETH_HLEN);
1972 }
1973
1974 /**
1975  * afiucv_hs_callback_syn - react on received SYN
1976  **/
1977 static int afiucv_hs_callback_syn(struct sock *sk, struct sk_buff *skb)
1978 {
1979         struct af_iucv_trans_hdr *trans_hdr = iucv_trans_hdr(skb);
1980         struct sock *nsk;
1981         struct iucv_sock *iucv, *niucv;
1982         int err;
1983
1984         iucv = iucv_sk(sk);
1985         if (!iucv) {
1986                 /* no sock - connection refused */
1987                 afiucv_swap_src_dest(skb);
1988                 trans_hdr->flags = AF_IUCV_FLAG_SYN | AF_IUCV_FLAG_FIN;
1989                 err = dev_queue_xmit(skb);
1990                 goto out;
1991         }
1992
1993         nsk = iucv_sock_alloc(NULL, sk->sk_type, GFP_ATOMIC, 0);
1994         bh_lock_sock(sk);
1995         if ((sk->sk_state != IUCV_LISTEN) ||
1996             sk_acceptq_is_full(sk) ||
1997             !nsk) {
1998                 /* error on server socket - connection refused */
1999                 afiucv_swap_src_dest(skb);
2000                 trans_hdr->flags = AF_IUCV_FLAG_SYN | AF_IUCV_FLAG_FIN;
2001                 err = dev_queue_xmit(skb);
2002                 iucv_sock_kill(nsk);
2003                 bh_unlock_sock(sk);
2004                 goto out;
2005         }
2006
2007         niucv = iucv_sk(nsk);
2008         iucv_sock_init(nsk, sk);
2009         niucv->transport = AF_IUCV_TRANS_HIPER;
2010         niucv->msglimit = iucv->msglimit;
2011         if (!trans_hdr->window)
2012                 niucv->msglimit_peer = IUCV_HIPER_MSGLIM_DEFAULT;
2013         else
2014                 niucv->msglimit_peer = trans_hdr->window;
2015         memcpy(niucv->dst_name, trans_hdr->srcAppName, 8);
2016         memcpy(niucv->dst_user_id, trans_hdr->srcUserID, 8);
2017         memcpy(niucv->src_name, iucv->src_name, 8);
2018         memcpy(niucv->src_user_id, iucv->src_user_id, 8);
2019         nsk->sk_bound_dev_if = sk->sk_bound_dev_if;
2020         niucv->hs_dev = iucv->hs_dev;
2021         dev_hold(niucv->hs_dev);
2022         afiucv_swap_src_dest(skb);
2023         trans_hdr->flags = AF_IUCV_FLAG_SYN | AF_IUCV_FLAG_ACK;
2024         trans_hdr->window = niucv->msglimit;
2025         /* if receiver acks the xmit connection is established */
2026         err = dev_queue_xmit(skb);
2027         if (!err) {
2028                 iucv_accept_enqueue(sk, nsk);
2029                 nsk->sk_state = IUCV_CONNECTED;
2030                 sk->sk_data_ready(sk);
2031         } else
2032                 iucv_sock_kill(nsk);
2033         bh_unlock_sock(sk);
2034
2035 out:
2036         return NET_RX_SUCCESS;
2037 }
2038
2039 /**
2040  * afiucv_hs_callback_synack() - react on received SYN-ACK
2041  **/
2042 static int afiucv_hs_callback_synack(struct sock *sk, struct sk_buff *skb)
2043 {
2044         struct iucv_sock *iucv = iucv_sk(sk);
2045
2046         if (!iucv)
2047                 goto out;
2048         if (sk->sk_state != IUCV_BOUND)
2049                 goto out;
2050         bh_lock_sock(sk);
2051         iucv->msglimit_peer = iucv_trans_hdr(skb)->window;
2052         sk->sk_state = IUCV_CONNECTED;
2053         sk->sk_state_change(sk);
2054         bh_unlock_sock(sk);
2055 out:
2056         kfree_skb(skb);
2057         return NET_RX_SUCCESS;
2058 }
2059
2060 /**
2061  * afiucv_hs_callback_synfin() - react on received SYN_FIN
2062  **/
2063 static int afiucv_hs_callback_synfin(struct sock *sk, struct sk_buff *skb)
2064 {
2065         struct iucv_sock *iucv = iucv_sk(sk);
2066
2067         if (!iucv)
2068                 goto out;
2069         if (sk->sk_state != IUCV_BOUND)
2070                 goto out;
2071         bh_lock_sock(sk);
2072         sk->sk_state = IUCV_DISCONN;
2073         sk->sk_state_change(sk);
2074         bh_unlock_sock(sk);
2075 out:
2076         kfree_skb(skb);
2077         return NET_RX_SUCCESS;
2078 }
2079
2080 /**
2081  * afiucv_hs_callback_fin() - react on received FIN
2082  **/
2083 static int afiucv_hs_callback_fin(struct sock *sk, struct sk_buff *skb)
2084 {
2085         struct iucv_sock *iucv = iucv_sk(sk);
2086
2087         /* other end of connection closed */
2088         if (!iucv)
2089                 goto out;
2090         bh_lock_sock(sk);
2091         if (sk->sk_state == IUCV_CONNECTED) {
2092                 sk->sk_state = IUCV_DISCONN;
2093                 sk->sk_state_change(sk);
2094         }
2095         bh_unlock_sock(sk);
2096 out:
2097         kfree_skb(skb);
2098         return NET_RX_SUCCESS;
2099 }
2100
2101 /**
2102  * afiucv_hs_callback_win() - react on received WIN
2103  **/
2104 static int afiucv_hs_callback_win(struct sock *sk, struct sk_buff *skb)
2105 {
2106         struct iucv_sock *iucv = iucv_sk(sk);
2107
2108         if (!iucv)
2109                 return NET_RX_SUCCESS;
2110
2111         if (sk->sk_state != IUCV_CONNECTED)
2112                 return NET_RX_SUCCESS;
2113
2114         atomic_sub(iucv_trans_hdr(skb)->window, &iucv->msg_sent);
2115         iucv_sock_wake_msglim(sk);
2116         return NET_RX_SUCCESS;
2117 }
2118
2119 /**
2120  * afiucv_hs_callback_rx() - react on received data
2121  **/
2122 static int afiucv_hs_callback_rx(struct sock *sk, struct sk_buff *skb)
2123 {
2124         struct iucv_sock *iucv = iucv_sk(sk);
2125
2126         if (!iucv) {
2127                 kfree_skb(skb);
2128                 return NET_RX_SUCCESS;
2129         }
2130
2131         if (sk->sk_state != IUCV_CONNECTED) {
2132                 kfree_skb(skb);
2133                 return NET_RX_SUCCESS;
2134         }
2135
2136         if (sk->sk_shutdown & RCV_SHUTDOWN) {
2137                 kfree_skb(skb);
2138                 return NET_RX_SUCCESS;
2139         }
2140
2141         /* write stuff from iucv_msg to skb cb */
2142         skb_pull(skb, sizeof(struct af_iucv_trans_hdr));
2143         skb_reset_transport_header(skb);
2144         skb_reset_network_header(skb);
2145         IUCV_SKB_CB(skb)->offset = 0;
2146         if (sk_filter(sk, skb)) {
2147                 atomic_inc(&sk->sk_drops);      /* skb rejected by filter */
2148                 kfree_skb(skb);
2149                 return NET_RX_SUCCESS;
2150         }
2151
2152         spin_lock(&iucv->message_q.lock);
2153         if (skb_queue_empty(&iucv->backlog_skb_q)) {
2154                 if (__sock_queue_rcv_skb(sk, skb))
2155                         /* handle rcv queue full */
2156                         skb_queue_tail(&iucv->backlog_skb_q, skb);
2157         } else
2158                 skb_queue_tail(&iucv_sk(sk)->backlog_skb_q, skb);
2159         spin_unlock(&iucv->message_q.lock);
2160         return NET_RX_SUCCESS;
2161 }
2162
2163 /**
2164  * afiucv_hs_rcv() - base function for arriving data through HiperSockets
2165  *                   transport
2166  *                   called from netif RX softirq
2167  **/
2168 static int afiucv_hs_rcv(struct sk_buff *skb, struct net_device *dev,
2169         struct packet_type *pt, struct net_device *orig_dev)
2170 {
2171         struct sock *sk;
2172         struct iucv_sock *iucv;
2173         struct af_iucv_trans_hdr *trans_hdr;
2174         int err = NET_RX_SUCCESS;
2175         char nullstring[8];
2176
2177         if (!pskb_may_pull(skb, sizeof(*trans_hdr))) {
2178                 WARN_ONCE(1, "AF_IUCV failed to receive skb, len=%u", skb->len);
2179                 kfree_skb(skb);
2180                 return NET_RX_SUCCESS;
2181         }
2182
2183         trans_hdr = iucv_trans_hdr(skb);
2184         EBCASC(trans_hdr->destAppName, sizeof(trans_hdr->destAppName));
2185         EBCASC(trans_hdr->destUserID, sizeof(trans_hdr->destUserID));
2186         EBCASC(trans_hdr->srcAppName, sizeof(trans_hdr->srcAppName));
2187         EBCASC(trans_hdr->srcUserID, sizeof(trans_hdr->srcUserID));
2188         memset(nullstring, 0, sizeof(nullstring));
2189         iucv = NULL;
2190         sk = NULL;
2191         read_lock(&iucv_sk_list.lock);
2192         sk_for_each(sk, &iucv_sk_list.head) {
2193                 if (trans_hdr->flags == AF_IUCV_FLAG_SYN) {
2194                         if ((!memcmp(&iucv_sk(sk)->src_name,
2195                                      trans_hdr->destAppName, 8)) &&
2196                             (!memcmp(&iucv_sk(sk)->src_user_id,
2197                                      trans_hdr->destUserID, 8)) &&
2198                             (!memcmp(&iucv_sk(sk)->dst_name, nullstring, 8)) &&
2199                             (!memcmp(&iucv_sk(sk)->dst_user_id,
2200                                      nullstring, 8))) {
2201                                 iucv = iucv_sk(sk);
2202                                 break;
2203                         }
2204                 } else {
2205                         if ((!memcmp(&iucv_sk(sk)->src_name,
2206                                      trans_hdr->destAppName, 8)) &&
2207                             (!memcmp(&iucv_sk(sk)->src_user_id,
2208                                      trans_hdr->destUserID, 8)) &&
2209                             (!memcmp(&iucv_sk(sk)->dst_name,
2210                                      trans_hdr->srcAppName, 8)) &&
2211                             (!memcmp(&iucv_sk(sk)->dst_user_id,
2212                                      trans_hdr->srcUserID, 8))) {
2213                                 iucv = iucv_sk(sk);
2214                                 break;
2215                         }
2216                 }
2217         }
2218         read_unlock(&iucv_sk_list.lock);
2219         if (!iucv)
2220                 sk = NULL;
2221
2222         /* no sock
2223         how should we send with no sock
2224         1) send without sock no send rc checking?
2225         2) introduce default sock to handle this cases
2226
2227          SYN -> send SYN|ACK in good case, send SYN|FIN in bad case
2228          data -> send FIN
2229          SYN|ACK, SYN|FIN, FIN -> no action? */
2230
2231         switch (trans_hdr->flags) {
2232         case AF_IUCV_FLAG_SYN:
2233                 /* connect request */
2234                 err = afiucv_hs_callback_syn(sk, skb);
2235                 break;
2236         case (AF_IUCV_FLAG_SYN | AF_IUCV_FLAG_ACK):
2237                 /* connect request confirmed */
2238                 err = afiucv_hs_callback_synack(sk, skb);
2239                 break;
2240         case (AF_IUCV_FLAG_SYN | AF_IUCV_FLAG_FIN):
2241                 /* connect request refused */
2242                 err = afiucv_hs_callback_synfin(sk, skb);
2243                 break;
2244         case (AF_IUCV_FLAG_FIN):
2245                 /* close request */
2246                 err = afiucv_hs_callback_fin(sk, skb);
2247                 break;
2248         case (AF_IUCV_FLAG_WIN):
2249                 err = afiucv_hs_callback_win(sk, skb);
2250                 if (skb->len == sizeof(struct af_iucv_trans_hdr)) {
2251                         kfree_skb(skb);
2252                         break;
2253                 }
2254                 /* fall through - and receive non-zero length data */
2255         case (AF_IUCV_FLAG_SHT):
2256                 /* shutdown request */
2257                 /* fall through - and receive zero length data */
2258         case 0:
2259                 /* plain data frame */
2260                 IUCV_SKB_CB(skb)->class = trans_hdr->iucv_hdr.class;
2261                 err = afiucv_hs_callback_rx(sk, skb);
2262                 break;
2263         default:
2264                 kfree_skb(skb);
2265         }
2266
2267         return err;
2268 }
2269
2270 /**
2271  * afiucv_hs_callback_txnotify() - handle send notifcations from HiperSockets
2272  *                                 transport
2273  **/
2274 static void afiucv_hs_callback_txnotify(struct sk_buff *skb,
2275                                         enum iucv_tx_notify n)
2276 {
2277         struct sock *isk = skb->sk;
2278         struct sock *sk = NULL;
2279         struct iucv_sock *iucv = NULL;
2280         struct sk_buff_head *list;
2281         struct sk_buff *list_skb;
2282         struct sk_buff *nskb;
2283         unsigned long flags;
2284
2285         read_lock_irqsave(&iucv_sk_list.lock, flags);
2286         sk_for_each(sk, &iucv_sk_list.head)
2287                 if (sk == isk) {
2288                         iucv = iucv_sk(sk);
2289                         break;
2290                 }
2291         read_unlock_irqrestore(&iucv_sk_list.lock, flags);
2292
2293         if (!iucv || sock_flag(sk, SOCK_ZAPPED))
2294                 return;
2295
2296         list = &iucv->send_skb_q;
2297         spin_lock_irqsave(&list->lock, flags);
2298         skb_queue_walk_safe(list, list_skb, nskb) {
2299                 if (skb_shinfo(list_skb) == skb_shinfo(skb)) {
2300                         switch (n) {
2301                         case TX_NOTIFY_OK:
2302                                 __skb_unlink(list_skb, list);
2303                                 kfree_skb(list_skb);
2304                                 iucv_sock_wake_msglim(sk);
2305                                 break;
2306                         case TX_NOTIFY_PENDING:
2307                                 atomic_inc(&iucv->pendings);
2308                                 break;
2309                         case TX_NOTIFY_DELAYED_OK:
2310                                 __skb_unlink(list_skb, list);
2311                                 atomic_dec(&iucv->pendings);
2312                                 if (atomic_read(&iucv->pendings) <= 0)
2313                                         iucv_sock_wake_msglim(sk);
2314                                 kfree_skb(list_skb);
2315                                 break;
2316                         case TX_NOTIFY_UNREACHABLE:
2317                         case TX_NOTIFY_DELAYED_UNREACHABLE:
2318                         case TX_NOTIFY_TPQFULL: /* not yet used */
2319                         case TX_NOTIFY_GENERALERROR:
2320                         case TX_NOTIFY_DELAYED_GENERALERROR:
2321                                 __skb_unlink(list_skb, list);
2322                                 kfree_skb(list_skb);
2323                                 if (sk->sk_state == IUCV_CONNECTED) {
2324                                         sk->sk_state = IUCV_DISCONN;
2325                                         sk->sk_state_change(sk);
2326                                 }
2327                                 break;
2328                         }
2329                         break;
2330                 }
2331         }
2332         spin_unlock_irqrestore(&list->lock, flags);
2333
2334         if (sk->sk_state == IUCV_CLOSING) {
2335                 if (skb_queue_empty(&iucv_sk(sk)->send_skb_q)) {
2336                         sk->sk_state = IUCV_CLOSED;
2337                         sk->sk_state_change(sk);
2338                 }
2339         }
2340
2341 }
2342
2343 /*
2344  * afiucv_netdev_event: handle netdev notifier chain events
2345  */
2346 static int afiucv_netdev_event(struct notifier_block *this,
2347                                unsigned long event, void *ptr)
2348 {
2349         struct net_device *event_dev = netdev_notifier_info_to_dev(ptr);
2350         struct sock *sk;
2351         struct iucv_sock *iucv;
2352
2353         switch (event) {
2354         case NETDEV_REBOOT:
2355         case NETDEV_GOING_DOWN:
2356                 sk_for_each(sk, &iucv_sk_list.head) {
2357                         iucv = iucv_sk(sk);
2358                         if ((iucv->hs_dev == event_dev) &&
2359                             (sk->sk_state == IUCV_CONNECTED)) {
2360                                 if (event == NETDEV_GOING_DOWN)
2361                                         iucv_send_ctrl(sk, AF_IUCV_FLAG_FIN);
2362                                 sk->sk_state = IUCV_DISCONN;
2363                                 sk->sk_state_change(sk);
2364                         }
2365                 }
2366                 break;
2367         case NETDEV_DOWN:
2368         case NETDEV_UNREGISTER:
2369         default:
2370                 break;
2371         }
2372         return NOTIFY_DONE;
2373 }
2374
2375 static struct notifier_block afiucv_netdev_notifier = {
2376         .notifier_call = afiucv_netdev_event,
2377 };
2378
2379 static const struct proto_ops iucv_sock_ops = {
2380         .family         = PF_IUCV,
2381         .owner          = THIS_MODULE,
2382         .release        = iucv_sock_release,
2383         .bind           = iucv_sock_bind,
2384         .connect        = iucv_sock_connect,
2385         .listen         = iucv_sock_listen,
2386         .accept         = iucv_sock_accept,
2387         .getname        = iucv_sock_getname,
2388         .sendmsg        = iucv_sock_sendmsg,
2389         .recvmsg        = iucv_sock_recvmsg,
2390         .poll           = iucv_sock_poll,
2391         .ioctl          = sock_no_ioctl,
2392         .mmap           = sock_no_mmap,
2393         .socketpair     = sock_no_socketpair,
2394         .shutdown       = iucv_sock_shutdown,
2395         .setsockopt     = iucv_sock_setsockopt,
2396         .getsockopt     = iucv_sock_getsockopt,
2397 };
2398
2399 static const struct net_proto_family iucv_sock_family_ops = {
2400         .family = AF_IUCV,
2401         .owner  = THIS_MODULE,
2402         .create = iucv_sock_create,
2403 };
2404
2405 static struct packet_type iucv_packet_type = {
2406         .type = cpu_to_be16(ETH_P_AF_IUCV),
2407         .func = afiucv_hs_rcv,
2408 };
2409
2410 static int afiucv_iucv_init(void)
2411 {
2412         int err;
2413
2414         err = pr_iucv->iucv_register(&af_iucv_handler, 0);
2415         if (err)
2416                 goto out;
2417         /* establish dummy device */
2418         af_iucv_driver.bus = pr_iucv->bus;
2419         err = driver_register(&af_iucv_driver);
2420         if (err)
2421                 goto out_iucv;
2422         af_iucv_dev = kzalloc(sizeof(struct device), GFP_KERNEL);
2423         if (!af_iucv_dev) {
2424                 err = -ENOMEM;
2425                 goto out_driver;
2426         }
2427         dev_set_name(af_iucv_dev, "af_iucv");
2428         af_iucv_dev->bus = pr_iucv->bus;
2429         af_iucv_dev->parent = pr_iucv->root;
2430         af_iucv_dev->release = (void (*)(struct device *))kfree;
2431         af_iucv_dev->driver = &af_iucv_driver;
2432         err = device_register(af_iucv_dev);
2433         if (err)
2434                 goto out_iucv_dev;
2435         return 0;
2436
2437 out_iucv_dev:
2438         put_device(af_iucv_dev);
2439 out_driver:
2440         driver_unregister(&af_iucv_driver);
2441 out_iucv:
2442         pr_iucv->iucv_unregister(&af_iucv_handler, 0);
2443 out:
2444         return err;
2445 }
2446
2447 static void afiucv_iucv_exit(void)
2448 {
2449         device_unregister(af_iucv_dev);
2450         driver_unregister(&af_iucv_driver);
2451         pr_iucv->iucv_unregister(&af_iucv_handler, 0);
2452 }
2453
2454 static int __init afiucv_init(void)
2455 {
2456         int err;
2457
2458         if (MACHINE_IS_VM) {
2459                 cpcmd("QUERY USERID", iucv_userid, sizeof(iucv_userid), &err);
2460                 if (unlikely(err)) {
2461                         WARN_ON(err);
2462                         err = -EPROTONOSUPPORT;
2463                         goto out;
2464                 }
2465
2466                 pr_iucv = try_then_request_module(symbol_get(iucv_if), "iucv");
2467                 if (!pr_iucv) {
2468                         printk(KERN_WARNING "iucv_if lookup failed\n");
2469                         memset(&iucv_userid, 0, sizeof(iucv_userid));
2470                 }
2471         } else {
2472                 memset(&iucv_userid, 0, sizeof(iucv_userid));
2473                 pr_iucv = NULL;
2474         }
2475
2476         err = proto_register(&iucv_proto, 0);
2477         if (err)
2478                 goto out;
2479         err = sock_register(&iucv_sock_family_ops);
2480         if (err)
2481                 goto out_proto;
2482
2483         if (pr_iucv) {
2484                 err = afiucv_iucv_init();
2485                 if (err)
2486                         goto out_sock;
2487         }
2488
2489         err = register_netdevice_notifier(&afiucv_netdev_notifier);
2490         if (err)
2491                 goto out_notifier;
2492
2493         dev_add_pack(&iucv_packet_type);
2494         return 0;
2495
2496 out_notifier:
2497         if (pr_iucv)
2498                 afiucv_iucv_exit();
2499 out_sock:
2500         sock_unregister(PF_IUCV);
2501 out_proto:
2502         proto_unregister(&iucv_proto);
2503 out:
2504         if (pr_iucv)
2505                 symbol_put(iucv_if);
2506         return err;
2507 }
2508
2509 static void __exit afiucv_exit(void)
2510 {
2511         if (pr_iucv) {
2512                 afiucv_iucv_exit();
2513                 symbol_put(iucv_if);
2514         }
2515
2516         unregister_netdevice_notifier(&afiucv_netdev_notifier);
2517         dev_remove_pack(&iucv_packet_type);
2518         sock_unregister(PF_IUCV);
2519         proto_unregister(&iucv_proto);
2520 }
2521
2522 module_init(afiucv_init);
2523 module_exit(afiucv_exit);
2524
2525 MODULE_AUTHOR("Jennifer Hunt <[email protected]>");
2526 MODULE_DESCRIPTION("IUCV Sockets ver " VERSION);
2527 MODULE_VERSION(VERSION);
2528 MODULE_LICENSE("GPL");
2529 MODULE_ALIAS_NETPROTO(PF_IUCV);