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