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