net/iucv/af_iucv.c

   1 /*
   2  *  linux/net/iucv/af_iucv.c
   3  *
   4  *  IUCV protocol stack for Linux on zSeries
   5  *
   6  *  Copyright 2006 IBM Corporation
   7  *
   8  *  Author(s):  Jennifer Hunt <jenhunt@us.ibm.com>
   9  */
  10
  11 #define KMSG_COMPONENT "af_iucv"
  12 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
  13
  14 #include <linux/module.h>
  15 #include <linux/types.h>
  16 #include <linux/list.h>
  17 #include <linux/errno.h>
  18 #include <linux/kernel.h>
  19 #include <linux/sched.h>
  20 #include <linux/slab.h>
  21 #include <linux/skbuff.h>
  22 #include <linux/init.h>
  23 #include <linux/poll.h>
  24 #include <net/sock.h>
  25 #include <asm/ebcdic.h>
  26 #include <asm/cpcmd.h>
  27 #include <linux/kmod.h>
  28
  29 #include <net/iucv/iucv.h>
  30 #include <net/iucv/af_iucv.h>
  31
  32 #define CONFIG_IUCV_SOCK_DEBUG 1
  33
  34 #define IPRMDATA 0x80
  35 #define VERSION "1.0"
  36
  37 static char iucv_userid[80];
  38
  39 static 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 void iucv_sock_kill(struct sock *sk);
  48 static void iucv_sock_close(struct sock *sk);
  49
  50 /* Call Back functions */
  51 static void iucv_callback_rx(struct iucv_path *, struct iucv_message *);
  52 static void iucv_callback_txdone(struct iucv_path *, struct iucv_message *);
  53 static void iucv_callback_connack(struct iucv_path *, u8 ipuser[16]);
  54 static int iucv_callback_connreq(struct iucv_path *, u8 ipvmid[8],
  55                                  u8 ipuser[16]);
  56 static void iucv_callback_connrej(struct iucv_path *, u8 ipuser[16]);
  57 static void iucv_callback_shutdown(struct iucv_path *, u8 ipuser[16]);
  58
  59 static struct iucv_sock_list iucv_sk_list = {
  60         .lock = __RW_LOCK_UNLOCKED(iucv_sk_list.lock),
  61         .autobind_name = ATOMIC_INIT(0)
  62 };
  63
  64 static struct iucv_handler af_iucv_handler = {
  65         .path_pending     = iucv_callback_connreq,
  66         .path_complete    = iucv_callback_connack,
  67         .path_severed     = iucv_callback_connrej,
  68         .message_pending  = iucv_callback_rx,
  69         .message_complete = iucv_callback_txdone,
  70         .path_quiesced    = iucv_callback_shutdown,
  71 };
  72
  73 static inline void high_nmcpy(unsigned char *dst, char *src)
  74 {
  75        memcpy(dst, src, 8);
  76 }
  77
  78 static inline void low_nmcpy(unsigned char *dst, char *src)
  79 {
  80        memcpy(&dst[8], src, 8);
  81 }
  82
  83 /* Timers */
  84 static void iucv_sock_timeout(unsigned long arg)
  85 {
  86         struct sock *sk = (struct sock *)arg;
  87
  88         bh_lock_sock(sk);
  89         sk->sk_err = ETIMEDOUT;
  90         sk->sk_state_change(sk);
  91         bh_unlock_sock(sk);
  92
  93         iucv_sock_kill(sk);
  94         sock_put(sk);
  95 }
  96
  97 static void iucv_sock_clear_timer(struct sock *sk)
  98 {
  99         sk_stop_timer(sk, &sk->sk_timer);
 100 }
 101
 102 static struct sock *__iucv_get_sock_by_name(char *nm)
 103 {
 104         struct sock *sk;
 105         struct hlist_node *node;
 106
 107         sk_for_each(sk, node, &iucv_sk_list.head)
 108                 if (!memcmp(&iucv_sk(sk)->src_name, nm, 8))
 109                         return sk;
 110
 111         return NULL;
 112 }
 113
 114 static void iucv_sock_destruct(struct sock *sk)
 115 {
 116         skb_queue_purge(&sk->sk_receive_queue);
 117         skb_queue_purge(&sk->sk_write_queue);
 118 }
 119
 120 /* Cleanup Listen */
 121 static void iucv_sock_cleanup_listen(struct sock *parent)
 122 {
 123         struct sock *sk;
 124
 125         /* Close non-accepted connections */
 126         while ((sk = iucv_accept_dequeue(parent, NULL))) {
 127                 iucv_sock_close(sk);
 128                 iucv_sock_kill(sk);
 129         }
 130
 131         parent->sk_state = IUCV_CLOSED;
 132         sock_set_flag(parent, SOCK_ZAPPED);
 133 }
 134
 135 /* Kill socket */
 136 static void iucv_sock_kill(struct sock *sk)
 137 {
 138         if (!sock_flag(sk, SOCK_ZAPPED) || sk->sk_socket)
 139                 return;
 140
 141         iucv_sock_unlink(&iucv_sk_list, sk);
 142         sock_set_flag(sk, SOCK_DEAD);
 143         sock_put(sk);
 144 }
 145
 146 /* Close an IUCV socket */
 147 static void iucv_sock_close(struct sock *sk)
 148 {
 149         unsigned char user_data[16];
 150         struct iucv_sock *iucv = iucv_sk(sk);
 151         int err;
 152         unsigned long timeo;
 153
 154         iucv_sock_clear_timer(sk);
 155         lock_sock(sk);
 156
 157         switch (sk->sk_state) {
 158         case IUCV_LISTEN:
 159                 iucv_sock_cleanup_listen(sk);
 160                 break;
 161
 162         case IUCV_CONNECTED:
 163         case IUCV_DISCONN:
 164                 err = 0;
 165
 166                 sk->sk_state = IUCV_CLOSING;
 167                 sk->sk_state_change(sk);
 168
 169                 if (!skb_queue_empty(&iucv->send_skb_q)) {
 170                         if (sock_flag(sk, SOCK_LINGER) && sk->sk_lingertime)
 171                                 timeo = sk->sk_lingertime;
 172                         else
 173                                 timeo = IUCV_DISCONN_TIMEOUT;
 174                         err = iucv_sock_wait_state(sk, IUCV_CLOSED, 0, timeo);
 175                 }
 176
 177                 sk->sk_state = IUCV_CLOSED;
 178                 sk->sk_state_change(sk);
 179
 180                 if (iucv->path) {
 181                         low_nmcpy(user_data, iucv->src_name);
 182                         high_nmcpy(user_data, iucv->dst_name);
 183                         ASCEBC(user_data, sizeof(user_data));
 184                         err = iucv_path_sever(iucv->path, user_data);
 185                         iucv_path_free(iucv->path);
 186                         iucv->path = NULL;
 187                 }
 188
 189                 sk->sk_err = ECONNRESET;
 190                 sk->sk_state_change(sk);
 191
 192                 skb_queue_purge(&iucv->send_skb_q);
 193                 skb_queue_purge(&iucv->backlog_skb_q);
 194
 195                 sock_set_flag(sk, SOCK_ZAPPED);
 196                 break;
 197
 198         default:
 199                 sock_set_flag(sk, SOCK_ZAPPED);
 200                 break;
 201         }
 202
 203         release_sock(sk);
 204         iucv_sock_kill(sk);
 205 }
 206
 207 static void iucv_sock_init(struct sock *sk, struct sock *parent)
 208 {
 209         if (parent)
 210                 sk->sk_type = parent->sk_type;
 211 }
 212
 213 static struct sock *iucv_sock_alloc(struct socket *sock, int proto, gfp_t prio)
 214 {
 215         struct sock *sk;
 216
 217         sk = sk_alloc(&init_net, PF_IUCV, prio, &iucv_proto);
 218         if (!sk)
 219                 return NULL;
 220
 221         sock_init_data(sock, sk);
 222         INIT_LIST_HEAD(&iucv_sk(sk)->accept_q);
 223         spin_lock_init(&iucv_sk(sk)->accept_q_lock);
 224         skb_queue_head_init(&iucv_sk(sk)->send_skb_q);
 225         INIT_LIST_HEAD(&iucv_sk(sk)->message_q.list);
 226         spin_lock_init(&iucv_sk(sk)->message_q.lock);
 227         skb_queue_head_init(&iucv_sk(sk)->backlog_skb_q);
 228         iucv_sk(sk)->send_tag = 0;
 229
 230         sk->sk_destruct = iucv_sock_destruct;
 231         sk->sk_sndtimeo = IUCV_CONN_TIMEOUT;
 232         sk->sk_allocation = GFP_DMA;
 233
 234         sock_reset_flag(sk, SOCK_ZAPPED);
 235
 236         sk->sk_protocol = proto;
 237         sk->sk_state    = IUCV_OPEN;
 238
 239         setup_timer(&sk->sk_timer, iucv_sock_timeout, (unsigned long)sk);
 240
 241         iucv_sock_link(&iucv_sk_list, sk);
 242         return sk;
 243 }
 244
 245 /* Create an IUCV socket */
 246 static int iucv_sock_create(struct net *net, struct socket *sock, int protocol)
 247 {
 248         struct sock *sk;
 249
 250         if (sock->type != SOCK_STREAM)
 251                 return -ESOCKTNOSUPPORT;
 252
 253         sock->state = SS_UNCONNECTED;
 254         sock->ops = &iucv_sock_ops;
 255
 256         sk = iucv_sock_alloc(sock, protocol, GFP_KERNEL);
 257         if (!sk)
 258                 return -ENOMEM;
 259
 260         iucv_sock_init(sk, NULL);
 261
 262         return 0;
 263 }
 264
 265 void iucv_sock_link(struct iucv_sock_list *l, struct sock *sk)
 266 {
 267         write_lock_bh(&l->lock);
 268         sk_add_node(sk, &l->head);
 269         write_unlock_bh(&l->lock);
 270 }
 271
 272 void iucv_sock_unlink(struct iucv_sock_list *l, struct sock *sk)
 273 {
 274         write_lock_bh(&l->lock);
 275         sk_del_node_init(sk);
 276         write_unlock_bh(&l->lock);
 277 }
 278
 279 void iucv_accept_enqueue(struct sock *parent, struct sock *sk)
 280 {
 281         unsigned long flags;
 282         struct iucv_sock *par = iucv_sk(parent);
 283
 284         sock_hold(sk);
 285         spin_lock_irqsave(&par->accept_q_lock, flags);
 286         list_add_tail(&iucv_sk(sk)->accept_q, &par->accept_q);
 287         spin_unlock_irqrestore(&par->accept_q_lock, flags);
 288         iucv_sk(sk)->parent = parent;
 289         parent->sk_ack_backlog++;
 290 }
 291
 292 void iucv_accept_unlink(struct sock *sk)
 293 {
 294         unsigned long flags;
 295         struct iucv_sock *par = iucv_sk(iucv_sk(sk)->parent);
 296
 297         spin_lock_irqsave(&par->accept_q_lock, flags);
 298         list_del_init(&iucv_sk(sk)->accept_q);
 299         spin_unlock_irqrestore(&par->accept_q_lock, flags);
 300         iucv_sk(sk)->parent->sk_ack_backlog--;
 301         iucv_sk(sk)->parent = NULL;
 302         sock_put(sk);
 303 }
 304
 305 struct sock *iucv_accept_dequeue(struct sock *parent, struct socket *newsock)
 306 {
 307         struct iucv_sock *isk, *n;
 308         struct sock *sk;
 309
 310         list_for_each_entry_safe(isk, n, &iucv_sk(parent)->accept_q, accept_q) {
 311                 sk = (struct sock *) isk;
 312                 lock_sock(sk);
 313
 314                 if (sk->sk_state == IUCV_CLOSED) {
 315                         iucv_accept_unlink(sk);
 316                         release_sock(sk);
 317                         continue;
 318                 }
 319
 320                 if (sk->sk_state == IUCV_CONNECTED ||
 321                     sk->sk_state == IUCV_SEVERED ||
 322                     !newsock) {
 323                         iucv_accept_unlink(sk);
 324                         if (newsock)
 325                                 sock_graft(sk, newsock);
 326
 327                         if (sk->sk_state == IUCV_SEVERED)
 328                                 sk->sk_state = IUCV_DISCONN;
 329
 330                         release_sock(sk);
 331                         return sk;
 332                 }
 333
 334                 release_sock(sk);
 335         }
 336         return NULL;
 337 }
 338
 339 int iucv_sock_wait_state(struct sock *sk, int state, int state2,
 340                          unsigned long timeo)
 341 {
 342         DECLARE_WAITQUEUE(wait, current);
 343         int err = 0;
 344
 345         add_wait_queue(sk->sk_sleep, &wait);
 346         while (sk->sk_state != state && sk->sk_state != state2) {
 347                 set_current_state(TASK_INTERRUPTIBLE);
 348
 349                 if (!timeo) {
 350                         err = -EAGAIN;
 351                         break;
 352                 }
 353
 354                 if (signal_pending(current)) {
 355                         err = sock_intr_errno(timeo);
 356                         break;
 357                 }
 358
 359                 release_sock(sk);
 360                 timeo = schedule_timeout(timeo);
 361                 lock_sock(sk);
 362
 363                 err = sock_error(sk);
 364                 if (err)
 365                         break;
 366         }
 367         set_current_state(TASK_RUNNING);
 368         remove_wait_queue(sk->sk_sleep, &wait);
 369         return err;
 370 }
 371
 372 /* Bind an unbound socket */
 373 static int iucv_sock_bind(struct socket *sock, struct sockaddr *addr,
 374                           int addr_len)
 375 {
 376         struct sockaddr_iucv *sa = (struct sockaddr_iucv *) addr;
 377         struct sock *sk = sock->sk;
 378         struct iucv_sock *iucv;
 379         int err;
 380
 381         /* Verify the input sockaddr */
 382         if (!addr || addr->sa_family != AF_IUCV)
 383                 return -EINVAL;
 384
 385         lock_sock(sk);
 386         if (sk->sk_state != IUCV_OPEN) {
 387                 err = -EBADFD;
 388                 goto done;
 389         }
 390
 391         write_lock_bh(&iucv_sk_list.lock);
 392
 393         iucv = iucv_sk(sk);
 394         if (__iucv_get_sock_by_name(sa->siucv_name)) {
 395                 err = -EADDRINUSE;
 396                 goto done_unlock;
 397         }
 398         if (iucv->path) {
 399                 err = 0;
 400                 goto done_unlock;
 401         }
 402
 403         /* Bind the socket */
 404         memcpy(iucv->src_name, sa->siucv_name, 8);
 405
 406         /* Copy the user id */
 407         memcpy(iucv->src_user_id, iucv_userid, 8);
 408         sk->sk_state = IUCV_BOUND;
 409         err = 0;
 410
 411 done_unlock:
 412         /* Release the socket list lock */
 413         write_unlock_bh(&iucv_sk_list.lock);
 414 done:
 415         release_sock(sk);
 416         return err;
 417 }
 418
 419 /* Automatically bind an unbound socket */
 420 static int iucv_sock_autobind(struct sock *sk)
 421 {
 422         struct iucv_sock *iucv = iucv_sk(sk);
 423         char query_buffer[80];
 424         char name[12];
 425         int err = 0;
 426
 427         /* Set the userid and name */
 428         cpcmd("QUERY USERID", query_buffer, sizeof(query_buffer), &err);
 429         if (unlikely(err))
 430                 return -EPROTO;
 431
 432         memcpy(iucv->src_user_id, query_buffer, 8);
 433
 434         write_lock_bh(&iucv_sk_list.lock);
 435
 436         sprintf(name, "%08x", atomic_inc_return(&iucv_sk_list.autobind_name));
 437         while (__iucv_get_sock_by_name(name)) {
 438                 sprintf(name, "%08x",
 439                         atomic_inc_return(&iucv_sk_list.autobind_name));
 440         }
 441
 442         write_unlock_bh(&iucv_sk_list.lock);
 443
 444         memcpy(&iucv->src_name, name, 8);
 445
 446         return err;
 447 }
 448
 449 /* Connect an unconnected socket */
 450 static int iucv_sock_connect(struct socket *sock, struct sockaddr *addr,
 451                              int alen, int flags)
 452 {
 453         struct sockaddr_iucv *sa = (struct sockaddr_iucv *) addr;
 454         struct sock *sk = sock->sk;
 455         struct iucv_sock *iucv;
 456         unsigned char user_data[16];
 457         int err;
 458
 459         if (addr->sa_family != AF_IUCV || alen < sizeof(struct sockaddr_iucv))
 460                 return -EINVAL;
 461
 462         if (sk->sk_state != IUCV_OPEN && sk->sk_state != IUCV_BOUND)
 463                 return -EBADFD;
 464
 465         if (sk->sk_type != SOCK_STREAM)
 466                 return -EINVAL;
 467
 468         iucv = iucv_sk(sk);
 469
 470         if (sk->sk_state == IUCV_OPEN) {
 471                 err = iucv_sock_autobind(sk);
 472                 if (unlikely(err))
 473                         return err;
 474         }
 475
 476         lock_sock(sk);
 477
 478         /* Set the destination information */
 479         memcpy(iucv_sk(sk)->dst_user_id, sa->siucv_user_id, 8);
 480         memcpy(iucv_sk(sk)->dst_name, sa->siucv_name, 8);
 481
 482         high_nmcpy(user_data, sa->siucv_name);
 483         low_nmcpy(user_data, iucv_sk(sk)->src_name);
 484         ASCEBC(user_data, sizeof(user_data));
 485
 486         iucv = iucv_sk(sk);
 487         /* Create path. */
 488         iucv->path = iucv_path_alloc(IUCV_QUEUELEN_DEFAULT,
 489                                      IPRMDATA, GFP_KERNEL);
 490         if (!iucv->path) {
 491                 err = -ENOMEM;
 492                 goto done;
 493         }
 494         err = iucv_path_connect(iucv->path, &af_iucv_handler,
 495                                 sa->siucv_user_id, NULL, user_data, sk);
 496         if (err) {
 497                 iucv_path_free(iucv->path);
 498                 iucv->path = NULL;
 499                 switch (err) {
 500                 case 0x0b:      /* Target communicator is not logged on */
 501                         err = -ENETUNREACH;
 502                         break;
 503                 case 0x0d:      /* Max connections for this guest exceeded */
 504                 case 0x0e:      /* Max connections for target guest exceeded */
 505                         err = -EAGAIN;
 506                         break;
 507                 case 0x0f:      /* Missing IUCV authorization */
 508                         err = -EACCES;
 509                         break;
 510                 default:
 511                         err = -ECONNREFUSED;
 512                         break;
 513                 }
 514                 goto done;
 515         }
 516
 517         if (sk->sk_state != IUCV_CONNECTED) {
 518                 err = iucv_sock_wait_state(sk, IUCV_CONNECTED, IUCV_DISCONN,
 519                                 sock_sndtimeo(sk, flags & O_NONBLOCK));
 520         }
 521
 522         if (sk->sk_state == IUCV_DISCONN) {
 523                 release_sock(sk);
 524                 return -ECONNREFUSED;
 525         }
 526
 527         if (err) {
 528                 iucv_path_sever(iucv->path, NULL);
 529                 iucv_path_free(iucv->path);
 530                 iucv->path = NULL;
 531         }
 532
 533 done:
 534         release_sock(sk);
 535         return err;
 536 }
 537
 538 /* Move a socket into listening state. */
 539 static int iucv_sock_listen(struct socket *sock, int backlog)
 540 {
 541         struct sock *sk = sock->sk;
 542         int err;
 543
 544         lock_sock(sk);
 545
 546         err = -EINVAL;
 547         if (sk->sk_state != IUCV_BOUND || sock->type != SOCK_STREAM)
 548                 goto done;
 549
 550         sk->sk_max_ack_backlog = backlog;
 551         sk->sk_ack_backlog = 0;
 552         sk->sk_state = IUCV_LISTEN;
 553         err = 0;
 554
 555 done:
 556         release_sock(sk);
 557         return err;
 558 }
 559
 560 /* Accept a pending connection */
 561 static int iucv_sock_accept(struct socket *sock, struct socket *newsock,
 562                             int flags)
 563 {
 564         DECLARE_WAITQUEUE(wait, current);
 565         struct sock *sk = sock->sk, *nsk;
 566         long timeo;
 567         int err = 0;
 568
 569         lock_sock_nested(sk, SINGLE_DEPTH_NESTING);
 570
 571         if (sk->sk_state != IUCV_LISTEN) {
 572                 err = -EBADFD;
 573                 goto done;
 574         }
 575
 576         timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);
 577
 578         /* Wait for an incoming connection */
 579         add_wait_queue_exclusive(sk->sk_sleep, &wait);
 580         while (!(nsk = iucv_accept_dequeue(sk, newsock))) {
 581                 set_current_state(TASK_INTERRUPTIBLE);
 582                 if (!timeo) {
 583                         err = -EAGAIN;
 584                         break;
 585                 }
 586
 587                 release_sock(sk);
 588                 timeo = schedule_timeout(timeo);
 589                 lock_sock_nested(sk, SINGLE_DEPTH_NESTING);
 590
 591                 if (sk->sk_state != IUCV_LISTEN) {
 592                         err = -EBADFD;
 593                         break;
 594                 }
 595
 596                 if (signal_pending(current)) {
 597                         err = sock_intr_errno(timeo);
 598                         break;
 599                 }
 600         }
 601
 602         set_current_state(TASK_RUNNING);
 603         remove_wait_queue(sk->sk_sleep, &wait);
 604
 605         if (err)
 606                 goto done;
 607
 608         newsock->state = SS_CONNECTED;
 609
 610 done:
 611         release_sock(sk);
 612         return err;
 613 }
 614
 615 static int iucv_sock_getname(struct socket *sock, struct sockaddr *addr,
 616                              int *len, int peer)
 617 {
 618         struct sockaddr_iucv *siucv = (struct sockaddr_iucv *) addr;
 619         struct sock *sk = sock->sk;
 620
 621         addr->sa_family = AF_IUCV;
 622         *len = sizeof(struct sockaddr_iucv);
 623
 624         if (peer) {
 625                 memcpy(siucv->siucv_user_id, iucv_sk(sk)->dst_user_id, 8);
 626                 memcpy(siucv->siucv_name, &iucv_sk(sk)->dst_name, 8);
 627         } else {
 628                 memcpy(siucv->siucv_user_id, iucv_sk(sk)->src_user_id, 8);
 629                 memcpy(siucv->siucv_name, iucv_sk(sk)->src_name, 8);
 630         }
 631         memset(&siucv->siucv_port, 0, sizeof(siucv->siucv_port));
 632         memset(&siucv->siucv_addr, 0, sizeof(siucv->siucv_addr));
 633         memset(siucv->siucv_nodeid, 0, sizeof(siucv->siucv_nodeid));
 634
 635         return 0;
 636 }
 637
 638 static int iucv_sock_sendmsg(struct kiocb *iocb, struct socket *sock,
 639                              struct msghdr *msg, size_t len)
 640 {
 641         struct sock *sk = sock->sk;
 642         struct iucv_sock *iucv = iucv_sk(sk);
 643         struct sk_buff *skb;
 644         struct iucv_message txmsg;
 645         char user_id[9];
 646         char appl_id[9];
 647         int err;
 648
 649         err = sock_error(sk);
 650         if (err)
 651                 return err;
 652
 653         if (msg->msg_flags & MSG_OOB)
 654                 return -EOPNOTSUPP;
 655
 656         lock_sock(sk);
 657
 658         if (sk->sk_shutdown & SEND_SHUTDOWN) {
 659                 err = -EPIPE;
 660                 goto out;
 661         }
 662
 663         if (sk->sk_state == IUCV_CONNECTED) {
 664                 if (!(skb = sock_alloc_send_skb(sk, len,
 665                                                 msg->msg_flags & MSG_DONTWAIT,
 666                                                 &err)))
 667                         goto out;
 668
 669                 if (memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len)) {
 670                         err = -EFAULT;
 671                         goto fail;
 672                 }
 673
 674                 txmsg.class = 0;
 675                 memcpy(&txmsg.class, skb->data, skb->len >= 4 ? 4 : skb->len);
 676                 txmsg.tag = iucv->send_tag++;
 677                 memcpy(skb->cb, &txmsg.tag, 4);
 678                 skb_queue_tail(&iucv->send_skb_q, skb);
 679                 err = iucv_message_send(iucv->path, &txmsg, 0, 0,
 680                                         (void *) skb->data, skb->len);
 681                 if (err) {
 682                         if (err == 3) {
 683                                 user_id[8] = 0;
 684                                 memcpy(user_id, iucv->dst_user_id, 8);
 685                                 appl_id[8] = 0;
 686                                 memcpy(appl_id, iucv->dst_name, 8);
 687                                 pr_err("Application %s on z/VM guest %s"
 688                                        " exceeds message limit\n",
 689                                        user_id, appl_id);
 690                         }
 691                         skb_unlink(skb, &iucv->send_skb_q);
 692                         err = -EPIPE;
 693                         goto fail;
 694                 }
 695
 696         } else {
 697                 err = -ENOTCONN;
 698                 goto out;
 699         }
 700
 701         release_sock(sk);
 702         return len;
 703
 704 fail:
 705         kfree_skb(skb);
 706 out:
 707         release_sock(sk);
 708         return err;
 709 }
 710
 711 static int iucv_fragment_skb(struct sock *sk, struct sk_buff *skb, int len)
 712 {
 713         int dataleft, size, copied = 0;
 714         struct sk_buff *nskb;
 715
 716         dataleft = len;
 717         while (dataleft) {
 718                 if (dataleft >= sk->sk_rcvbuf / 4)
 719                         size = sk->sk_rcvbuf / 4;
 720                 else
 721                         size = dataleft;
 722
 723                 nskb = alloc_skb(size, GFP_ATOMIC | GFP_DMA);
 724                 if (!nskb)
 725                         return -ENOMEM;
 726
 727                 memcpy(nskb->data, skb->data + copied, size);
 728                 copied += size;
 729                 dataleft -= size;
 730
 731                 skb_reset_transport_header(nskb);
 732                 skb_reset_network_header(nskb);
 733                 nskb->len = size;
 734
 735                 skb_queue_tail(&iucv_sk(sk)->backlog_skb_q, nskb);
 736         }
 737
 738         return 0;
 739 }
 740
 741 static void iucv_process_message(struct sock *sk, struct sk_buff *skb,
 742                                  struct iucv_path *path,
 743                                  struct iucv_message *msg)
 744 {
 745         int rc;
 746
 747         if (msg->flags & IPRMDATA) {
 748                 skb->data = NULL;
 749                 skb->len = 0;
 750         } else {
 751                 rc = iucv_message_receive(path, msg, 0, skb->data,
 752                                           msg->length, NULL);
 753                 if (rc) {
 754                         kfree_skb(skb);
 755                         return;
 756                 }
 757                 if (skb->truesize >= sk->sk_rcvbuf / 4) {
 758                         rc = iucv_fragment_skb(sk, skb, msg->length);
 759                         kfree_skb(skb);
 760                         skb = NULL;
 761                         if (rc) {
 762                                 iucv_path_sever(path, NULL);
 763                                 return;
 764                         }
 765                         skb = skb_dequeue(&iucv_sk(sk)->backlog_skb_q);
 766                 } else {
 767                         skb_reset_transport_header(skb);
 768                         skb_reset_network_header(skb);
 769                         skb->len = msg->length;
 770                 }
 771         }
 772
 773         if (sock_queue_rcv_skb(sk, skb))
 774                 skb_queue_head(&iucv_sk(sk)->backlog_skb_q, skb);
 775 }
 776
 777 static void iucv_process_message_q(struct sock *sk)
 778 {
 779         struct iucv_sock *iucv = iucv_sk(sk);
 780         struct sk_buff *skb;
 781         struct sock_msg_q *p, *n;
 782
 783         list_for_each_entry_safe(p, n, &iucv->message_q.list, list) {
 784                 skb = alloc_skb(p->msg.length, GFP_ATOMIC | GFP_DMA);
 785                 if (!skb)
 786                         break;
 787                 iucv_process_message(sk, skb, p->path, &p->msg);
 788                 list_del(&p->list);
 789                 kfree(p);
 790                 if (!skb_queue_empty(&iucv->backlog_skb_q))
 791                         break;
 792         }
 793 }
 794
 795 static int iucv_sock_recvmsg(struct kiocb *iocb, struct socket *sock,
 796                              struct msghdr *msg, size_t len, int flags)
 797 {
 798         int noblock = flags & MSG_DONTWAIT;
 799         struct sock *sk = sock->sk;
 800         struct iucv_sock *iucv = iucv_sk(sk);
 801         int target, copied = 0;
 802         struct sk_buff *skb, *rskb, *cskb;
 803         int err = 0;
 804
 805         if ((sk->sk_state == IUCV_DISCONN || sk->sk_state == IUCV_SEVERED) &&
 806             skb_queue_empty(&iucv->backlog_skb_q) &&
 807             skb_queue_empty(&sk->sk_receive_queue) &&
 808             list_empty(&iucv->message_q.list))
 809                 return 0;
 810
 811         if (flags & (MSG_OOB))
 812                 return -EOPNOTSUPP;
 813
 814         target = sock_rcvlowat(sk, flags & MSG_WAITALL, len);
 815
 816         skb = skb_recv_datagram(sk, flags, noblock, &err);
 817         if (!skb) {
 818                 if (sk->sk_shutdown & RCV_SHUTDOWN)
 819                         return 0;
 820                 return err;
 821         }
 822
 823         copied = min_t(unsigned int, skb->len, len);
 824
 825         cskb = skb;
 826         if (memcpy_toiovec(msg->msg_iov, cskb->data, copied)) {
 827                 skb_queue_head(&sk->sk_receive_queue, skb);
 828                 if (copied == 0)
 829                         return -EFAULT;
 830                 goto done;
 831         }
 832
 833         len -= copied;
 834
 835         /* Mark read part of skb as used */
 836         if (!(flags & MSG_PEEK)) {
 837                 skb_pull(skb, copied);
 838
 839                 if (skb->len) {
 840                         skb_queue_head(&sk->sk_receive_queue, skb);
 841                         goto done;
 842                 }
 843
 844                 kfree_skb(skb);
 845
 846                 /* Queue backlog skbs */
 847                 rskb = skb_dequeue(&iucv->backlog_skb_q);
 848                 while (rskb) {
 849                         if (sock_queue_rcv_skb(sk, rskb)) {
 850                                 skb_queue_head(&iucv->backlog_skb_q,
 851                                                 rskb);
 852                                 break;
 853                         } else {
 854                                 rskb = skb_dequeue(&iucv->backlog_skb_q);
 855                         }
 856                 }
 857                 if (skb_queue_empty(&iucv->backlog_skb_q)) {
 858                         spin_lock_bh(&iucv->message_q.lock);
 859                         if (!list_empty(&iucv->message_q.list))
 860                                 iucv_process_message_q(sk);
 861                         spin_unlock_bh(&iucv->message_q.lock);
 862                 }
 863
 864         } else
 865                 skb_queue_head(&sk->sk_receive_queue, skb);
 866
 867 done:
 868         return err ? : copied;
 869 }
 870
 871 static inline unsigned int iucv_accept_poll(struct sock *parent)
 872 {
 873         struct iucv_sock *isk, *n;
 874         struct sock *sk;
 875
 876         list_for_each_entry_safe(isk, n, &iucv_sk(parent)->accept_q, accept_q) {
 877                 sk = (struct sock *) isk;
 878
 879                 if (sk->sk_state == IUCV_CONNECTED)
 880                         return POLLIN | POLLRDNORM;
 881         }
 882
 883         return 0;
 884 }
 885
 886 unsigned int iucv_sock_poll(struct file *file, struct socket *sock,
 887                             poll_table *wait)
 888 {
 889         struct sock *sk = sock->sk;
 890         unsigned int mask = 0;
 891
 892         poll_wait(file, sk->sk_sleep, wait);
 893
 894         if (sk->sk_state == IUCV_LISTEN)
 895                 return iucv_accept_poll(sk);
 896
 897         if (sk->sk_err || !skb_queue_empty(&sk->sk_error_queue))
 898                 mask |= POLLERR;
 899
 900         if (sk->sk_shutdown & RCV_SHUTDOWN)
 901                 mask |= POLLRDHUP;
 902
 903         if (sk->sk_shutdown == SHUTDOWN_MASK)
 904                 mask |= POLLHUP;
 905
 906         if (!skb_queue_empty(&sk->sk_receive_queue) ||
 907             (sk->sk_shutdown & RCV_SHUTDOWN))
 908                 mask |= POLLIN | POLLRDNORM;
 909
 910         if (sk->sk_state == IUCV_CLOSED)
 911                 mask |= POLLHUP;
 912
 913         if (sk->sk_state == IUCV_DISCONN || sk->sk_state == IUCV_SEVERED)
 914                 mask |= POLLIN;
 915
 916         if (sock_writeable(sk))
 917                 mask |= POLLOUT | POLLWRNORM | POLLWRBAND;
 918         else
 919                 set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
 920
 921         return mask;
 922 }
 923
 924 static int iucv_sock_shutdown(struct socket *sock, int how)
 925 {
 926         struct sock *sk = sock->sk;
 927         struct iucv_sock *iucv = iucv_sk(sk);
 928         struct iucv_message txmsg;
 929         int err = 0;
 930         u8 prmmsg[8] = {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01};
 931
 932         how++;
 933
 934         if ((how & ~SHUTDOWN_MASK) || !how)
 935                 return -EINVAL;
 936
 937         lock_sock(sk);
 938         switch (sk->sk_state) {
 939         case IUCV_CLOSED:
 940                 err = -ENOTCONN;
 941                 goto fail;
 942
 943         default:
 944                 sk->sk_shutdown |= how;
 945                 break;
 946         }
 947
 948         if (how == SEND_SHUTDOWN || how == SHUTDOWN_MASK) {
 949                 txmsg.class = 0;
 950                 txmsg.tag = 0;
 951                 err = iucv_message_send(iucv->path, &txmsg, IUCV_IPRMDATA, 0,
 952                                         (void *) prmmsg, 8);
 953                 if (err) {
 954                         switch (err) {
 955                         case 1:
 956                                 err = -ENOTCONN;
 957                                 break;
 958                         case 2:
 959                                 err = -ECONNRESET;
 960                                 break;
 961                         default:
 962                                 err = -ENOTCONN;
 963                                 break;
 964                         }
 965                 }
 966         }
 967
 968         if (how == RCV_SHUTDOWN || how == SHUTDOWN_MASK) {
 969                 err = iucv_path_quiesce(iucv_sk(sk)->path, NULL);
 970                 if (err)
 971                         err = -ENOTCONN;
 972
 973                 skb_queue_purge(&sk->sk_receive_queue);
 974         }
 975
 976         /* Wake up anyone sleeping in poll */
 977         sk->sk_state_change(sk);
 978
 979 fail:
 980         release_sock(sk);
 981         return err;
 982 }
 983
 984 static int iucv_sock_release(struct socket *sock)
 985 {
 986         struct sock *sk = sock->sk;
 987         int err = 0;
 988
 989         if (!sk)
 990                 return 0;
 991
 992         iucv_sock_close(sk);
 993
 994         /* Unregister with IUCV base support */
 995         if (iucv_sk(sk)->path) {
 996                 iucv_path_sever(iucv_sk(sk)->path, NULL);
 997                 iucv_path_free(iucv_sk(sk)->path);
 998                 iucv_sk(sk)->path = NULL;
 999         }
1000
1001         sock_orphan(sk);
1002         iucv_sock_kill(sk);
1003         return err;
1004 }
1005
1006 /* Callback wrappers - called from iucv base support */
1007 static int iucv_callback_connreq(struct iucv_path *path,
1008                                  u8 ipvmid[8], u8 ipuser[16])
1009 {
1010         unsigned char user_data[16];
1011         unsigned char nuser_data[16];
1012         unsigned char src_name[8];
1013         struct hlist_node *node;
1014         struct sock *sk, *nsk;
1015         struct iucv_sock *iucv, *niucv;
1016         int err;
1017
1018         memcpy(src_name, ipuser, 8);
1019         EBCASC(src_name, 8);
1020         /* Find out if this path belongs to af_iucv. */
1021         read_lock(&iucv_sk_list.lock);
1022         iucv = NULL;
1023         sk = NULL;
1024         sk_for_each(sk, node, &iucv_sk_list.head)
1025                 if (sk->sk_state == IUCV_LISTEN &&
1026                     !memcmp(&iucv_sk(sk)->src_name, src_name, 8)) {
1027                         /*
1028                          * Found a listening socket with
1029                          * src_name == ipuser[0-7].
1030                          */
1031                         iucv = iucv_sk(sk);
1032                         break;
1033                 }
1034         read_unlock(&iucv_sk_list.lock);
1035         if (!iucv)
1036                 /* No socket found, not one of our paths. */
1037                 return -EINVAL;
1038
1039         bh_lock_sock(sk);
1040
1041         /* Check if parent socket is listening */
1042         low_nmcpy(user_data, iucv->src_name);
1043         high_nmcpy(user_data, iucv->dst_name);
1044         ASCEBC(user_data, sizeof(user_data));
1045         if (sk->sk_state != IUCV_LISTEN) {
1046                 err = iucv_path_sever(path, user_data);
1047                 iucv_path_free(path);
1048                 goto fail;
1049         }
1050
1051         /* Check for backlog size */
1052         if (sk_acceptq_is_full(sk)) {
1053                 err = iucv_path_sever(path, user_data);
1054                 iucv_path_free(path);
1055                 goto fail;
1056         }
1057
1058         /* Create the new socket */
1059         nsk = iucv_sock_alloc(NULL, SOCK_STREAM, GFP_ATOMIC);
1060         if (!nsk) {
1061                 err = iucv_path_sever(path, user_data);
1062                 iucv_path_free(path);
1063                 goto fail;
1064         }
1065
1066         niucv = iucv_sk(nsk);
1067         iucv_sock_init(nsk, sk);
1068
1069         /* Set the new iucv_sock */
1070         memcpy(niucv->dst_name, ipuser + 8, 8);
1071         EBCASC(niucv->dst_name, 8);
1072         memcpy(niucv->dst_user_id, ipvmid, 8);
1073         memcpy(niucv->src_name, iucv->src_name, 8);
1074         memcpy(niucv->src_user_id, iucv->src_user_id, 8);
1075         niucv->path = path;
1076
1077         /* Call iucv_accept */
1078         high_nmcpy(nuser_data, ipuser + 8);
1079         memcpy(nuser_data + 8, niucv->src_name, 8);
1080         ASCEBC(nuser_data + 8, 8);
1081
1082         path->msglim = IUCV_QUEUELEN_DEFAULT;
1083         err = iucv_path_accept(path, &af_iucv_handler, nuser_data, nsk);
1084         if (err) {
1085                 err = iucv_path_sever(path, user_data);
1086                 iucv_path_free(path);
1087                 iucv_sock_kill(nsk);
1088                 goto fail;
1089         }
1090
1091         iucv_accept_enqueue(sk, nsk);
1092
1093         /* Wake up accept */
1094         nsk->sk_state = IUCV_CONNECTED;
1095         sk->sk_data_ready(sk, 1);
1096         err = 0;
1097 fail:
1098         bh_unlock_sock(sk);
1099         return 0;
1100 }
1101
1102 static void iucv_callback_connack(struct iucv_path *path, u8 ipuser[16])
1103 {
1104         struct sock *sk = path->private;
1105
1106         sk->sk_state = IUCV_CONNECTED;
1107         sk->sk_state_change(sk);
1108 }
1109
1110 static void iucv_callback_rx(struct iucv_path *path, struct iucv_message *msg)
1111 {
1112         struct sock *sk = path->private;
1113         struct iucv_sock *iucv = iucv_sk(sk);
1114         struct sk_buff *skb;
1115         struct sock_msg_q *save_msg;
1116         int len;
1117
1118         if (sk->sk_shutdown & RCV_SHUTDOWN)
1119                 return;
1120
1121         if (!list_empty(&iucv->message_q.list) ||
1122             !skb_queue_empty(&iucv->backlog_skb_q))
1123                 goto save_message;
1124
1125         len = atomic_read(&sk->sk_rmem_alloc);
1126         len += msg->length + sizeof(struct sk_buff);
1127         if (len > sk->sk_rcvbuf)
1128                 goto save_message;
1129
1130         skb = alloc_skb(msg->length, GFP_ATOMIC | GFP_DMA);
1131         if (!skb)
1132                 goto save_message;
1133
1134         spin_lock(&iucv->message_q.lock);
1135         iucv_process_message(sk, skb, path, msg);
1136         spin_unlock(&iucv->message_q.lock);
1137
1138         return;
1139
1140 save_message:
1141         save_msg = kzalloc(sizeof(struct sock_msg_q), GFP_ATOMIC | GFP_DMA);
1142         if (!save_msg)
1143                 return;
1144         save_msg->path = path;
1145         save_msg->msg = *msg;
1146
1147         spin_lock(&iucv->message_q.lock);
1148         list_add_tail(&save_msg->list, &iucv->message_q.list);
1149         spin_unlock(&iucv->message_q.lock);
1150 }
1151
1152 static void iucv_callback_txdone(struct iucv_path *path,
1153                                  struct iucv_message *msg)
1154 {
1155         struct sock *sk = path->private;
1156         struct sk_buff *this = NULL;
1157         struct sk_buff_head *list = &iucv_sk(sk)->send_skb_q;
1158         struct sk_buff *list_skb = list->next;
1159         unsigned long flags;
1160
1161         if (!skb_queue_empty(list)) {
1162                 spin_lock_irqsave(&list->lock, flags);
1163
1164                 while (list_skb != (struct sk_buff *)list) {
1165                         if (!memcmp(&msg->tag, list_skb->cb, 4)) {
1166                                 this = list_skb;
1167                                 break;
1168                         }
1169                         list_skb = list_skb->next;
1170                 }
1171                 if (this)
1172                         __skb_unlink(this, list);
1173
1174                 spin_unlock_irqrestore(&list->lock, flags);
1175
1176                 kfree_skb(this);
1177         }
1178         BUG_ON(!this);
1179
1180         if (sk->sk_state == IUCV_CLOSING) {
1181                 if (skb_queue_empty(&iucv_sk(sk)->send_skb_q)) {
1182                         sk->sk_state = IUCV_CLOSED;
1183                         sk->sk_state_change(sk);
1184                 }
1185         }
1186
1187 }
1188
1189 static void iucv_callback_connrej(struct iucv_path *path, u8 ipuser[16])
1190 {
1191         struct sock *sk = path->private;
1192
1193         if (!list_empty(&iucv_sk(sk)->accept_q))
1194                 sk->sk_state = IUCV_SEVERED;
1195         else
1196                 sk->sk_state = IUCV_DISCONN;
1197
1198         sk->sk_state_change(sk);
1199 }
1200
1201 /* called if the other communication side shuts down its RECV direction;
1202  * in turn, the callback sets SEND_SHUTDOWN to disable sending of data.
1203  */
1204 static void iucv_callback_shutdown(struct iucv_path *path, u8 ipuser[16])
1205 {
1206         struct sock *sk = path->private;
1207
1208         bh_lock_sock(sk);
1209         if (sk->sk_state != IUCV_CLOSED) {
1210                 sk->sk_shutdown |= SEND_SHUTDOWN;
1211                 sk->sk_state_change(sk);
1212         }
1213         bh_unlock_sock(sk);
1214 }
1215
1216 static struct proto_ops iucv_sock_ops = {
1217         .family         = PF_IUCV,
1218         .owner          = THIS_MODULE,
1219         .release        = iucv_sock_release,
1220         .bind           = iucv_sock_bind,
1221         .connect        = iucv_sock_connect,
1222         .listen         = iucv_sock_listen,
1223         .accept         = iucv_sock_accept,
1224         .getname        = iucv_sock_getname,
1225         .sendmsg        = iucv_sock_sendmsg,
1226         .recvmsg        = iucv_sock_recvmsg,
1227         .poll           = iucv_sock_poll,
1228         .ioctl          = sock_no_ioctl,
1229         .mmap           = sock_no_mmap,
1230         .socketpair     = sock_no_socketpair,
1231         .shutdown       = iucv_sock_shutdown,
1232         .setsockopt     = sock_no_setsockopt,
1233         .getsockopt     = sock_no_getsockopt
1234 };
1235
1236 static struct net_proto_family iucv_sock_family_ops = {
1237         .family = AF_IUCV,
1238         .owner  = THIS_MODULE,
1239         .create = iucv_sock_create,
1240 };
1241
1242 static int __init afiucv_init(void)
1243 {
1244         int err;
1245
1246         if (!MACHINE_IS_VM) {
1247                 pr_err("The af_iucv module cannot be loaded"
1248                        " without z/VM\n");
1249                 err = -EPROTONOSUPPORT;
1250                 goto out;
1251         }
1252         cpcmd("QUERY USERID", iucv_userid, sizeof(iucv_userid), &err);
1253         if (unlikely(err)) {
1254                 WARN_ON(err);
1255                 err = -EPROTONOSUPPORT;
1256                 goto out;
1257         }
1258
1259         err = iucv_register(&af_iucv_handler, 0);
1260         if (err)
1261                 goto out;
1262         err = proto_register(&iucv_proto, 0);
1263         if (err)
1264                 goto out_iucv;
1265         err = sock_register(&iucv_sock_family_ops);
1266         if (err)
1267                 goto out_proto;
1268         return 0;
1269
1270 out_proto:
1271         proto_unregister(&iucv_proto);
1272 out_iucv:
1273         iucv_unregister(&af_iucv_handler, 0);
1274 out:
1275         return err;
1276 }
1277
1278 static void __exit afiucv_exit(void)
1279 {
1280         sock_unregister(PF_IUCV);
1281         proto_unregister(&iucv_proto);
1282         iucv_unregister(&af_iucv_handler, 0);
1283 }
1284
1285 module_init(afiucv_init);
1286 module_exit(afiucv_exit);
1287
1288 MODULE_AUTHOR("Jennifer Hunt <jenhunt@us.ibm.com>");
1289 MODULE_DESCRIPTION("IUCV Sockets ver " VERSION);
1290 MODULE_VERSION(VERSION);
1291 MODULE_LICENSE("GPL");
1292 MODULE_ALIAS_NETPROTO(PF_IUCV);