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TOMOYO Linux Cross Reference
Linux/net/iucv/af_iucv.c

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  1 // SPDX-License-Identifier: GPL-2.0-only
  2 /*
  3  *  IUCV protocol stack for Linux on zSeries
  4  *
  5  *  Copyright IBM Corp. 2006, 2009
  6  *
  7  *  Author(s):  Jennifer Hunt <jenhunt@us.ibm.com>
  8  *              Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
  9  *  PM functions:
 10  *              Ursula Braun <ursula.braun@de.ibm.com>
 11  */
 12 
 13 #define KMSG_COMPONENT "af_iucv"
 14 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
 15 
 16 #include <linux/filter.h>
 17 #include <linux/module.h>
 18 #include <linux/netdevice.h>
 19 #include <linux/types.h>
 20 #include <linux/limits.h>
 21 #include <linux/list.h>
 22 #include <linux/errno.h>
 23 #include <linux/kernel.h>
 24 #include <linux/sched/signal.h>
 25 #include <linux/slab.h>
 26 #include <linux/skbuff.h>
 27 #include <linux/init.h>
 28 #include <linux/poll.h>
 29 #include <linux/security.h>
 30 #include <net/sock.h>
 31 #include <asm/ebcdic.h>
 32 #include <asm/cpcmd.h>
 33 #include <linux/kmod.h>
 34 
 35 #include <net/iucv/af_iucv.h>
 36 
 37 #define VERSION "1.2"
 38 
 39 static char iucv_userid[80];
 40 
 41 static struct proto iucv_proto = {
 42         .name           = "AF_IUCV",
 43         .owner          = THIS_MODULE,
 44         .obj_size       = sizeof(struct iucv_sock),
 45 };
 46 
 47 static struct iucv_interface *pr_iucv;
 48 static struct iucv_handler af_iucv_handler;
 49 
 50 /* special AF_IUCV IPRM messages */
 51 static const u8 iprm_shutdown[8] =
 52         {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01};
 53 
 54 #define TRGCLS_SIZE     sizeof_field(struct iucv_message, class)
 55 
 56 #define __iucv_sock_wait(sk, condition, timeo, ret)                     \
 57 do {                                                                    \
 58         DEFINE_WAIT(__wait);                                            \
 59         long __timeo = timeo;                                           \
 60         ret = 0;                                                        \
 61         prepare_to_wait(sk_sleep(sk), &__wait, TASK_INTERRUPTIBLE);     \
 62         while (!(condition)) {                                          \
 63                 if (!__timeo) {                                         \
 64                         ret = -EAGAIN;                                  \
 65                         break;                                          \
 66                 }                                                       \
 67                 if (signal_pending(current)) {                          \
 68                         ret = sock_intr_errno(__timeo);                 \
 69                         break;                                          \
 70                 }                                                       \
 71                 release_sock(sk);                                       \
 72                 __timeo = schedule_timeout(__timeo);                    \
 73                 lock_sock(sk);                                          \
 74                 ret = sock_error(sk);                                   \
 75                 if (ret)                                                \
 76                         break;                                          \
 77         }                                                               \
 78         finish_wait(sk_sleep(sk), &__wait);                             \
 79 } while (0)
 80 
 81 #define iucv_sock_wait(sk, condition, timeo)                            \
 82 ({                                                                      \
 83         int __ret = 0;                                                  \
 84         if (!(condition))                                               \
 85                 __iucv_sock_wait(sk, condition, timeo, __ret);          \
 86         __ret;                                                          \
 87 })
 88 
 89 static struct sock *iucv_accept_dequeue(struct sock *parent,
 90                                         struct socket *newsock);
 91 static void iucv_sock_kill(struct sock *sk);
 92 static void iucv_sock_close(struct sock *sk);
 93 
 94 static void afiucv_hs_callback_txnotify(struct sock *sk, enum iucv_tx_notify);
 95 
 96 static struct iucv_sock_list iucv_sk_list = {
 97         .lock = __RW_LOCK_UNLOCKED(iucv_sk_list.lock),
 98         .autobind_name = ATOMIC_INIT(0)
 99 };
100 
101 static inline void high_nmcpy(unsigned char *dst, char *src)
102 {
103        memcpy(dst, src, 8);
104 }
105 
106 static inline void low_nmcpy(unsigned char *dst, char *src)
107 {
108        memcpy(&dst[8], src, 8);
109 }
110 
111 /**
112  * iucv_msg_length() - Returns the length of an iucv message.
113  * @msg:        Pointer to struct iucv_message, MUST NOT be NULL
114  *
115  * The function returns the length of the specified iucv message @msg of data
116  * stored in a buffer and of data stored in the parameter list (PRMDATA).
117  *
118  * For IUCV_IPRMDATA, AF_IUCV uses the following convention to transport socket
119  * data:
120  *      PRMDATA[0..6]   socket data (max 7 bytes);
121  *      PRMDATA[7]      socket data length value (len is 0xff - PRMDATA[7])
122  *
123  * The socket data length is computed by subtracting the socket data length
124  * value from 0xFF.
125  * If the socket data len is greater 7, then PRMDATA can be used for special
126  * notifications (see iucv_sock_shutdown); and further,
127  * if the socket data len is > 7, the function returns 8.
128  *
129  * Use this function to allocate socket buffers to store iucv message data.
130  */
131 static inline size_t iucv_msg_length(struct iucv_message *msg)
132 {
133         size_t datalen;
134 
135         if (msg->flags & IUCV_IPRMDATA) {
136                 datalen = 0xff - msg->rmmsg[7];
137                 return (datalen < 8) ? datalen : 8;
138         }
139         return msg->length;
140 }
141 
142 /**
143  * iucv_sock_in_state() - check for specific states
144  * @sk:         sock structure
145  * @state:      first iucv sk state
146  * @state2:     second iucv sk state
147  *
148  * Returns true if the socket in either in the first or second state.
149  */
150 static int iucv_sock_in_state(struct sock *sk, int state, int state2)
151 {
152         return (sk->sk_state == state || sk->sk_state == state2);
153 }
154 
155 /**
156  * iucv_below_msglim() - function to check if messages can be sent
157  * @sk:         sock structure
158  *
159  * Returns true if the send queue length is lower than the message limit.
160  * Always returns true if the socket is not connected (no iucv path for
161  * checking the message limit).
162  */
163 static inline int iucv_below_msglim(struct sock *sk)
164 {
165         struct iucv_sock *iucv = iucv_sk(sk);
166 
167         if (sk->sk_state != IUCV_CONNECTED)
168                 return 1;
169         if (iucv->transport == AF_IUCV_TRANS_IUCV)
170                 return (atomic_read(&iucv->skbs_in_xmit) < iucv->path->msglim);
171         else
172                 return ((atomic_read(&iucv->msg_sent) < iucv->msglimit_peer) &&
173                         (atomic_read(&iucv->pendings) <= 0));
174 }
175 
176 /*
177  * iucv_sock_wake_msglim() - Wake up thread waiting on msg limit
178  */
179 static void iucv_sock_wake_msglim(struct sock *sk)
180 {
181         struct socket_wq *wq;
182 
183         rcu_read_lock();
184         wq = rcu_dereference(sk->sk_wq);
185         if (skwq_has_sleeper(wq))
186                 wake_up_interruptible_all(&wq->wait);
187         sk_wake_async_rcu(sk, SOCK_WAKE_SPACE, POLL_OUT);
188         rcu_read_unlock();
189 }
190 
191 /*
192  * afiucv_hs_send() - send a message through HiperSockets transport
193  */
194 static int afiucv_hs_send(struct iucv_message *imsg, struct sock *sock,
195                    struct sk_buff *skb, u8 flags)
196 {
197         struct iucv_sock *iucv = iucv_sk(sock);
198         struct af_iucv_trans_hdr *phs_hdr;
199         int err, confirm_recv = 0;
200 
201         phs_hdr = skb_push(skb, sizeof(*phs_hdr));
202         memset(phs_hdr, 0, sizeof(*phs_hdr));
203         skb_reset_network_header(skb);
204 
205         phs_hdr->magic = ETH_P_AF_IUCV;
206         phs_hdr->version = 1;
207         phs_hdr->flags = flags;
208         if (flags == AF_IUCV_FLAG_SYN)
209                 phs_hdr->window = iucv->msglimit;
210         else if ((flags == AF_IUCV_FLAG_WIN) || !flags) {
211                 confirm_recv = atomic_read(&iucv->msg_recv);
212                 phs_hdr->window = confirm_recv;
213                 if (confirm_recv)
214                         phs_hdr->flags = phs_hdr->flags | AF_IUCV_FLAG_WIN;
215         }
216         memcpy(phs_hdr->destUserID, iucv->dst_user_id, 8);
217         memcpy(phs_hdr->destAppName, iucv->dst_name, 8);
218         memcpy(phs_hdr->srcUserID, iucv->src_user_id, 8);
219         memcpy(phs_hdr->srcAppName, iucv->src_name, 8);
220         ASCEBC(phs_hdr->destUserID, sizeof(phs_hdr->destUserID));
221         ASCEBC(phs_hdr->destAppName, sizeof(phs_hdr->destAppName));
222         ASCEBC(phs_hdr->srcUserID, sizeof(phs_hdr->srcUserID));
223         ASCEBC(phs_hdr->srcAppName, sizeof(phs_hdr->srcAppName));
224         if (imsg)
225                 memcpy(&phs_hdr->iucv_hdr, imsg, sizeof(struct iucv_message));
226 
227         skb->dev = iucv->hs_dev;
228         if (!skb->dev) {
229                 err = -ENODEV;
230                 goto err_free;
231         }
232 
233         dev_hard_header(skb, skb->dev, ETH_P_AF_IUCV, NULL, NULL, skb->len);
234 
235         if (!(skb->dev->flags & IFF_UP) || !netif_carrier_ok(skb->dev)) {
236                 err = -ENETDOWN;
237                 goto err_free;
238         }
239         if (skb->len > skb->dev->mtu) {
240                 if (sock->sk_type == SOCK_SEQPACKET) {
241                         err = -EMSGSIZE;
242                         goto err_free;
243                 }
244                 err = pskb_trim(skb, skb->dev->mtu);
245                 if (err)
246                         goto err_free;
247         }
248         skb->protocol = cpu_to_be16(ETH_P_AF_IUCV);
249 
250         atomic_inc(&iucv->skbs_in_xmit);
251         err = dev_queue_xmit(skb);
252         if (net_xmit_eval(err)) {
253                 atomic_dec(&iucv->skbs_in_xmit);
254         } else {
255                 atomic_sub(confirm_recv, &iucv->msg_recv);
256                 WARN_ON(atomic_read(&iucv->msg_recv) < 0);
257         }
258         return net_xmit_eval(err);
259 
260 err_free:
261         kfree_skb(skb);
262         return err;
263 }
264 
265 static struct sock *__iucv_get_sock_by_name(char *nm)
266 {
267         struct sock *sk;
268 
269         sk_for_each(sk, &iucv_sk_list.head)
270                 if (!memcmp(&iucv_sk(sk)->src_name, nm, 8))
271                         return sk;
272 
273         return NULL;
274 }
275 
276 static void iucv_sock_destruct(struct sock *sk)
277 {
278         skb_queue_purge(&sk->sk_receive_queue);
279         skb_queue_purge(&sk->sk_error_queue);
280 
281         if (!sock_flag(sk, SOCK_DEAD)) {
282                 pr_err("Attempt to release alive iucv socket %p\n", sk);
283                 return;
284         }
285 
286         WARN_ON(atomic_read(&sk->sk_rmem_alloc));
287         WARN_ON(refcount_read(&sk->sk_wmem_alloc));
288         WARN_ON(sk->sk_wmem_queued);
289         WARN_ON(sk->sk_forward_alloc);
290 }
291 
292 /* Cleanup Listen */
293 static void iucv_sock_cleanup_listen(struct sock *parent)
294 {
295         struct sock *sk;
296 
297         /* Close non-accepted connections */
298         while ((sk = iucv_accept_dequeue(parent, NULL))) {
299                 iucv_sock_close(sk);
300                 iucv_sock_kill(sk);
301         }
302 
303         parent->sk_state = IUCV_CLOSED;
304 }
305 
306 static void iucv_sock_link(struct iucv_sock_list *l, struct sock *sk)
307 {
308         write_lock_bh(&l->lock);
309         sk_add_node(sk, &l->head);
310         write_unlock_bh(&l->lock);
311 }
312 
313 static void iucv_sock_unlink(struct iucv_sock_list *l, struct sock *sk)
314 {
315         write_lock_bh(&l->lock);
316         sk_del_node_init(sk);
317         write_unlock_bh(&l->lock);
318 }
319 
320 /* Kill socket (only if zapped and orphaned) */
321 static void iucv_sock_kill(struct sock *sk)
322 {
323         if (!sock_flag(sk, SOCK_ZAPPED) || sk->sk_socket)
324                 return;
325 
326         iucv_sock_unlink(&iucv_sk_list, sk);
327         sock_set_flag(sk, SOCK_DEAD);
328         sock_put(sk);
329 }
330 
331 /* Terminate an IUCV path */
332 static void iucv_sever_path(struct sock *sk, int with_user_data)
333 {
334         unsigned char user_data[16];
335         struct iucv_sock *iucv = iucv_sk(sk);
336         struct iucv_path *path = iucv->path;
337 
338         /* Whoever resets the path pointer, must sever and free it. */
339         if (xchg(&iucv->path, NULL)) {
340                 if (with_user_data) {
341                         low_nmcpy(user_data, iucv->src_name);
342                         high_nmcpy(user_data, iucv->dst_name);
343                         ASCEBC(user_data, sizeof(user_data));
344                         pr_iucv->path_sever(path, user_data);
345                 } else
346                         pr_iucv->path_sever(path, NULL);
347                 iucv_path_free(path);
348         }
349 }
350 
351 /* Send controlling flags through an IUCV socket for HIPER transport */
352 static int iucv_send_ctrl(struct sock *sk, u8 flags)
353 {
354         struct iucv_sock *iucv = iucv_sk(sk);
355         int err = 0;
356         int blen;
357         struct sk_buff *skb;
358         u8 shutdown = 0;
359 
360         blen = sizeof(struct af_iucv_trans_hdr) +
361                LL_RESERVED_SPACE(iucv->hs_dev);
362         if (sk->sk_shutdown & SEND_SHUTDOWN) {
363                 /* controlling flags should be sent anyway */
364                 shutdown = sk->sk_shutdown;
365                 sk->sk_shutdown &= RCV_SHUTDOWN;
366         }
367         skb = sock_alloc_send_skb(sk, blen, 1, &err);
368         if (skb) {
369                 skb_reserve(skb, blen);
370                 err = afiucv_hs_send(NULL, sk, skb, flags);
371         }
372         if (shutdown)
373                 sk->sk_shutdown = shutdown;
374         return err;
375 }
376 
377 /* Close an IUCV socket */
378 static void iucv_sock_close(struct sock *sk)
379 {
380         struct iucv_sock *iucv = iucv_sk(sk);
381         unsigned long timeo;
382         int err = 0;
383 
384         lock_sock(sk);
385 
386         switch (sk->sk_state) {
387         case IUCV_LISTEN:
388                 iucv_sock_cleanup_listen(sk);
389                 break;
390 
391         case IUCV_CONNECTED:
392                 if (iucv->transport == AF_IUCV_TRANS_HIPER) {
393                         err = iucv_send_ctrl(sk, AF_IUCV_FLAG_FIN);
394                         sk->sk_state = IUCV_DISCONN;
395                         sk->sk_state_change(sk);
396                 }
397                 fallthrough;
398 
399         case IUCV_DISCONN:
400                 sk->sk_state = IUCV_CLOSING;
401                 sk->sk_state_change(sk);
402 
403                 if (!err && atomic_read(&iucv->skbs_in_xmit) > 0) {
404                         if (sock_flag(sk, SOCK_LINGER) && sk->sk_lingertime)
405                                 timeo = sk->sk_lingertime;
406                         else
407                                 timeo = IUCV_DISCONN_TIMEOUT;
408                         iucv_sock_wait(sk,
409                                         iucv_sock_in_state(sk, IUCV_CLOSED, 0),
410                                         timeo);
411                 }
412                 fallthrough;
413 
414         case IUCV_CLOSING:
415                 sk->sk_state = IUCV_CLOSED;
416                 sk->sk_state_change(sk);
417 
418                 sk->sk_err = ECONNRESET;
419                 sk->sk_state_change(sk);
420 
421                 skb_queue_purge(&iucv->send_skb_q);
422                 skb_queue_purge(&iucv->backlog_skb_q);
423                 fallthrough;
424 
425         default:
426                 iucv_sever_path(sk, 1);
427         }
428 
429         if (iucv->hs_dev) {
430                 dev_put(iucv->hs_dev);
431                 iucv->hs_dev = NULL;
432                 sk->sk_bound_dev_if = 0;
433         }
434 
435         /* mark socket for deletion by iucv_sock_kill() */
436         sock_set_flag(sk, SOCK_ZAPPED);
437 
438         release_sock(sk);
439 }
440 
441 static void iucv_sock_init(struct sock *sk, struct sock *parent)
442 {
443         if (parent) {
444                 sk->sk_type = parent->sk_type;
445                 security_sk_clone(parent, sk);
446         }
447 }
448 
449 static struct sock *iucv_sock_alloc(struct socket *sock, int proto, gfp_t prio, int kern)
450 {
451         struct sock *sk;
452         struct iucv_sock *iucv;
453 
454         sk = sk_alloc(&init_net, PF_IUCV, prio, &iucv_proto, kern);
455         if (!sk)
456                 return NULL;
457         iucv = iucv_sk(sk);
458 
459         sock_init_data(sock, sk);
460         INIT_LIST_HEAD(&iucv->accept_q);
461         spin_lock_init(&iucv->accept_q_lock);
462         skb_queue_head_init(&iucv->send_skb_q);
463         INIT_LIST_HEAD(&iucv->message_q.list);
464         spin_lock_init(&iucv->message_q.lock);
465         skb_queue_head_init(&iucv->backlog_skb_q);
466         iucv->send_tag = 0;
467         atomic_set(&iucv->pendings, 0);
468         iucv->flags = 0;
469         iucv->msglimit = 0;
470         atomic_set(&iucv->skbs_in_xmit, 0);
471         atomic_set(&iucv->msg_sent, 0);
472         atomic_set(&iucv->msg_recv, 0);
473         iucv->path = NULL;
474         iucv->sk_txnotify = afiucv_hs_callback_txnotify;
475         memset(&iucv->init, 0, sizeof(iucv->init));
476         if (pr_iucv)
477                 iucv->transport = AF_IUCV_TRANS_IUCV;
478         else
479                 iucv->transport = AF_IUCV_TRANS_HIPER;
480 
481         sk->sk_destruct = iucv_sock_destruct;
482         sk->sk_sndtimeo = IUCV_CONN_TIMEOUT;
483 
484         sock_reset_flag(sk, SOCK_ZAPPED);
485 
486         sk->sk_protocol = proto;
487         sk->sk_state    = IUCV_OPEN;
488 
489         iucv_sock_link(&iucv_sk_list, sk);
490         return sk;
491 }
492 
493 static void iucv_accept_enqueue(struct sock *parent, struct sock *sk)
494 {
495         unsigned long flags;
496         struct iucv_sock *par = iucv_sk(parent);
497 
498         sock_hold(sk);
499         spin_lock_irqsave(&par->accept_q_lock, flags);
500         list_add_tail(&iucv_sk(sk)->accept_q, &par->accept_q);
501         spin_unlock_irqrestore(&par->accept_q_lock, flags);
502         iucv_sk(sk)->parent = parent;
503         sk_acceptq_added(parent);
504 }
505 
506 static void iucv_accept_unlink(struct sock *sk)
507 {
508         unsigned long flags;
509         struct iucv_sock *par = iucv_sk(iucv_sk(sk)->parent);
510 
511         spin_lock_irqsave(&par->accept_q_lock, flags);
512         list_del_init(&iucv_sk(sk)->accept_q);
513         spin_unlock_irqrestore(&par->accept_q_lock, flags);
514         sk_acceptq_removed(iucv_sk(sk)->parent);
515         iucv_sk(sk)->parent = NULL;
516         sock_put(sk);
517 }
518 
519 static struct sock *iucv_accept_dequeue(struct sock *parent,
520                                         struct socket *newsock)
521 {
522         struct iucv_sock *isk, *n;
523         struct sock *sk;
524 
525         list_for_each_entry_safe(isk, n, &iucv_sk(parent)->accept_q, accept_q) {
526                 sk = (struct sock *) isk;
527                 lock_sock(sk);
528 
529                 if (sk->sk_state == IUCV_CLOSED) {
530                         iucv_accept_unlink(sk);
531                         release_sock(sk);
532                         continue;
533                 }
534 
535                 if (sk->sk_state == IUCV_CONNECTED ||
536                     sk->sk_state == IUCV_DISCONN ||
537                     !newsock) {
538                         iucv_accept_unlink(sk);
539                         if (newsock)
540                                 sock_graft(sk, newsock);
541 
542                         release_sock(sk);
543                         return sk;
544                 }
545 
546                 release_sock(sk);
547         }
548         return NULL;
549 }
550 
551 static void __iucv_auto_name(struct iucv_sock *iucv)
552 {
553         char name[12];
554 
555         sprintf(name, "%08x", atomic_inc_return(&iucv_sk_list.autobind_name));
556         while (__iucv_get_sock_by_name(name)) {
557                 sprintf(name, "%08x",
558                         atomic_inc_return(&iucv_sk_list.autobind_name));
559         }
560         memcpy(iucv->src_name, name, 8);
561 }
562 
563 /* Bind an unbound socket */
564 static int iucv_sock_bind(struct socket *sock, struct sockaddr *addr,
565                           int addr_len)
566 {
567         DECLARE_SOCKADDR(struct sockaddr_iucv *, sa, addr);
568         char uid[sizeof(sa->siucv_user_id)];
569         struct sock *sk = sock->sk;
570         struct iucv_sock *iucv;
571         int err = 0;
572         struct net_device *dev;
573 
574         /* Verify the input sockaddr */
575         if (addr_len < sizeof(struct sockaddr_iucv) ||
576             addr->sa_family != AF_IUCV)
577                 return -EINVAL;
578 
579         lock_sock(sk);
580         if (sk->sk_state != IUCV_OPEN) {
581                 err = -EBADFD;
582                 goto done;
583         }
584 
585         write_lock_bh(&iucv_sk_list.lock);
586 
587         iucv = iucv_sk(sk);
588         if (__iucv_get_sock_by_name(sa->siucv_name)) {
589                 err = -EADDRINUSE;
590                 goto done_unlock;
591         }
592         if (iucv->path)
593                 goto done_unlock;
594 
595         /* Bind the socket */
596         if (pr_iucv)
597                 if (!memcmp(sa->siucv_user_id, iucv_userid, 8))
598                         goto vm_bind; /* VM IUCV transport */
599 
600         /* try hiper transport */
601         memcpy(uid, sa->siucv_user_id, sizeof(uid));
602         ASCEBC(uid, 8);
603         rcu_read_lock();
604         for_each_netdev_rcu(&init_net, dev) {
605                 if (!memcmp(dev->perm_addr, uid, 8)) {
606                         memcpy(iucv->src_user_id, sa->siucv_user_id, 8);
607                         /* Check for uninitialized siucv_name */
608                         if (strncmp(sa->siucv_name, "        ", 8) == 0)
609                                 __iucv_auto_name(iucv);
610                         else
611                                 memcpy(iucv->src_name, sa->siucv_name, 8);
612                         sk->sk_bound_dev_if = dev->ifindex;
613                         iucv->hs_dev = dev;
614                         dev_hold(dev);
615                         sk->sk_state = IUCV_BOUND;
616                         iucv->transport = AF_IUCV_TRANS_HIPER;
617                         if (!iucv->msglimit)
618                                 iucv->msglimit = IUCV_HIPER_MSGLIM_DEFAULT;
619                         rcu_read_unlock();
620                         goto done_unlock;
621                 }
622         }
623         rcu_read_unlock();
624 vm_bind:
625         if (pr_iucv) {
626                 /* use local userid for backward compat */
627                 memcpy(iucv->src_name, sa->siucv_name, 8);
628                 memcpy(iucv->src_user_id, iucv_userid, 8);
629                 sk->sk_state = IUCV_BOUND;
630                 iucv->transport = AF_IUCV_TRANS_IUCV;
631                 sk->sk_allocation |= GFP_DMA;
632                 if (!iucv->msglimit)
633                         iucv->msglimit = IUCV_QUEUELEN_DEFAULT;
634                 goto done_unlock;
635         }
636         /* found no dev to bind */
637         err = -ENODEV;
638 done_unlock:
639         /* Release the socket list lock */
640         write_unlock_bh(&iucv_sk_list.lock);
641 done:
642         release_sock(sk);
643         return err;
644 }
645 
646 /* Automatically bind an unbound socket */
647 static int iucv_sock_autobind(struct sock *sk)
648 {
649         struct iucv_sock *iucv = iucv_sk(sk);
650         int err = 0;
651 
652         if (unlikely(!pr_iucv))
653                 return -EPROTO;
654 
655         memcpy(iucv->src_user_id, iucv_userid, 8);
656         iucv->transport = AF_IUCV_TRANS_IUCV;
657         sk->sk_allocation |= GFP_DMA;
658 
659         write_lock_bh(&iucv_sk_list.lock);
660         __iucv_auto_name(iucv);
661         write_unlock_bh(&iucv_sk_list.lock);
662 
663         if (!iucv->msglimit)
664                 iucv->msglimit = IUCV_QUEUELEN_DEFAULT;
665 
666         return err;
667 }
668 
669 static int afiucv_path_connect(struct socket *sock, struct sockaddr *addr)
670 {
671         DECLARE_SOCKADDR(struct sockaddr_iucv *, sa, addr);
672         struct sock *sk = sock->sk;
673         struct iucv_sock *iucv = iucv_sk(sk);
674         unsigned char user_data[16];
675         int err;
676 
677         high_nmcpy(user_data, sa->siucv_name);
678         low_nmcpy(user_data, iucv->src_name);
679         ASCEBC(user_data, sizeof(user_data));
680 
681         /* Create path. */
682         iucv->path = iucv_path_alloc(iucv->msglimit,
683                                      IUCV_IPRMDATA, GFP_KERNEL);
684         if (!iucv->path) {
685                 err = -ENOMEM;
686                 goto done;
687         }
688         err = pr_iucv->path_connect(iucv->path, &af_iucv_handler,
689                                     sa->siucv_user_id, NULL, user_data,
690                                     sk);
691         if (err) {
692                 iucv_path_free(iucv->path);
693                 iucv->path = NULL;
694                 switch (err) {
695                 case 0x0b:      /* Target communicator is not logged on */
696                         err = -ENETUNREACH;
697                         break;
698                 case 0x0d:      /* Max connections for this guest exceeded */
699                 case 0x0e:      /* Max connections for target guest exceeded */
700                         err = -EAGAIN;
701                         break;
702                 case 0x0f:      /* Missing IUCV authorization */
703                         err = -EACCES;
704                         break;
705                 default:
706                         err = -ECONNREFUSED;
707                         break;
708                 }
709         }
710 done:
711         return err;
712 }
713 
714 /* Connect an unconnected socket */
715 static int iucv_sock_connect(struct socket *sock, struct sockaddr *addr,
716                              int alen, int flags)
717 {
718         DECLARE_SOCKADDR(struct sockaddr_iucv *, sa, addr);
719         struct sock *sk = sock->sk;
720         struct iucv_sock *iucv = iucv_sk(sk);
721         int err;
722 
723         if (alen < sizeof(struct sockaddr_iucv) || addr->sa_family != AF_IUCV)
724                 return -EINVAL;
725 
726         if (sk->sk_state != IUCV_OPEN && sk->sk_state != IUCV_BOUND)
727                 return -EBADFD;
728 
729         if (sk->sk_state == IUCV_OPEN &&
730             iucv->transport == AF_IUCV_TRANS_HIPER)
731                 return -EBADFD; /* explicit bind required */
732 
733         if (sk->sk_type != SOCK_STREAM && sk->sk_type != SOCK_SEQPACKET)
734                 return -EINVAL;
735 
736         if (sk->sk_state == IUCV_OPEN) {
737                 err = iucv_sock_autobind(sk);
738                 if (unlikely(err))
739                         return err;
740         }
741 
742         lock_sock(sk);
743 
744         /* Set the destination information */
745         memcpy(iucv->dst_user_id, sa->siucv_user_id, 8);
746         memcpy(iucv->dst_name, sa->siucv_name, 8);
747 
748         if (iucv->transport == AF_IUCV_TRANS_HIPER)
749                 err = iucv_send_ctrl(sock->sk, AF_IUCV_FLAG_SYN);
750         else
751                 err = afiucv_path_connect(sock, addr);
752         if (err)
753                 goto done;
754 
755         if (sk->sk_state != IUCV_CONNECTED)
756                 err = iucv_sock_wait(sk, iucv_sock_in_state(sk, IUCV_CONNECTED,
757                                                             IUCV_DISCONN),
758                                      sock_sndtimeo(sk, flags & O_NONBLOCK));
759 
760         if (sk->sk_state == IUCV_DISCONN || sk->sk_state == IUCV_CLOSED)
761                 err = -ECONNREFUSED;
762 
763         if (err && iucv->transport == AF_IUCV_TRANS_IUCV)
764                 iucv_sever_path(sk, 0);
765 
766 done:
767         release_sock(sk);
768         return err;
769 }
770 
771 /* Move a socket into listening state. */
772 static int iucv_sock_listen(struct socket *sock, int backlog)
773 {
774         struct sock *sk = sock->sk;
775         int err;
776 
777         lock_sock(sk);
778 
779         err = -EINVAL;
780         if (sk->sk_state != IUCV_BOUND)
781                 goto done;
782 
783         if (sock->type != SOCK_STREAM && sock->type != SOCK_SEQPACKET)
784                 goto done;
785 
786         sk->sk_max_ack_backlog = backlog;
787         sk->sk_ack_backlog = 0;
788         sk->sk_state = IUCV_LISTEN;
789         err = 0;
790 
791 done:
792         release_sock(sk);
793         return err;
794 }
795 
796 /* Accept a pending connection */
797 static int iucv_sock_accept(struct socket *sock, struct socket *newsock,
798                             struct proto_accept_arg *arg)
799 {
800         DECLARE_WAITQUEUE(wait, current);
801         struct sock *sk = sock->sk, *nsk;
802         long timeo;
803         int err = 0;
804 
805         lock_sock_nested(sk, SINGLE_DEPTH_NESTING);
806 
807         if (sk->sk_state != IUCV_LISTEN) {
808                 err = -EBADFD;
809                 goto done;
810         }
811 
812         timeo = sock_rcvtimeo(sk, arg->flags & O_NONBLOCK);
813 
814         /* Wait for an incoming connection */
815         add_wait_queue_exclusive(sk_sleep(sk), &wait);
816         while (!(nsk = iucv_accept_dequeue(sk, newsock))) {
817                 set_current_state(TASK_INTERRUPTIBLE);
818                 if (!timeo) {
819                         err = -EAGAIN;
820                         break;
821                 }
822 
823                 release_sock(sk);
824                 timeo = schedule_timeout(timeo);
825                 lock_sock_nested(sk, SINGLE_DEPTH_NESTING);
826 
827                 if (sk->sk_state != IUCV_LISTEN) {
828                         err = -EBADFD;
829                         break;
830                 }
831 
832                 if (signal_pending(current)) {
833                         err = sock_intr_errno(timeo);
834                         break;
835                 }
836         }
837 
838         set_current_state(TASK_RUNNING);
839         remove_wait_queue(sk_sleep(sk), &wait);
840 
841         if (err)
842                 goto done;
843 
844         newsock->state = SS_CONNECTED;
845 
846 done:
847         release_sock(sk);
848         return err;
849 }
850 
851 static int iucv_sock_getname(struct socket *sock, struct sockaddr *addr,
852                              int peer)
853 {
854         DECLARE_SOCKADDR(struct sockaddr_iucv *, siucv, addr);
855         struct sock *sk = sock->sk;
856         struct iucv_sock *iucv = iucv_sk(sk);
857 
858         addr->sa_family = AF_IUCV;
859 
860         if (peer) {
861                 memcpy(siucv->siucv_user_id, iucv->dst_user_id, 8);
862                 memcpy(siucv->siucv_name, iucv->dst_name, 8);
863         } else {
864                 memcpy(siucv->siucv_user_id, iucv->src_user_id, 8);
865                 memcpy(siucv->siucv_name, iucv->src_name, 8);
866         }
867         memset(&siucv->siucv_port, 0, sizeof(siucv->siucv_port));
868         memset(&siucv->siucv_addr, 0, sizeof(siucv->siucv_addr));
869         memset(&siucv->siucv_nodeid, 0, sizeof(siucv->siucv_nodeid));
870 
871         return sizeof(struct sockaddr_iucv);
872 }
873 
874 /**
875  * iucv_send_iprm() - Send socket data in parameter list of an iucv message.
876  * @path:       IUCV path
877  * @msg:        Pointer to a struct iucv_message
878  * @skb:        The socket data to send, skb->len MUST BE <= 7
879  *
880  * Send the socket data in the parameter list in the iucv message
881  * (IUCV_IPRMDATA). The socket data is stored at index 0 to 6 in the parameter
882  * list and the socket data len at index 7 (last byte).
883  * See also iucv_msg_length().
884  *
885  * Returns the error code from the iucv_message_send() call.
886  */
887 static int iucv_send_iprm(struct iucv_path *path, struct iucv_message *msg,
888                           struct sk_buff *skb)
889 {
890         u8 prmdata[8];
891 
892         memcpy(prmdata, (void *) skb->data, skb->len);
893         prmdata[7] = 0xff - (u8) skb->len;
894         return pr_iucv->message_send(path, msg, IUCV_IPRMDATA, 0,
895                                  (void *) prmdata, 8);
896 }
897 
898 static int iucv_sock_sendmsg(struct socket *sock, struct msghdr *msg,
899                              size_t len)
900 {
901         struct sock *sk = sock->sk;
902         struct iucv_sock *iucv = iucv_sk(sk);
903         size_t headroom = 0;
904         size_t linear;
905         struct sk_buff *skb;
906         struct iucv_message txmsg = {0};
907         struct cmsghdr *cmsg;
908         int cmsg_done;
909         long timeo;
910         char user_id[9];
911         char appl_id[9];
912         int err;
913         int noblock = msg->msg_flags & MSG_DONTWAIT;
914 
915         err = sock_error(sk);
916         if (err)
917                 return err;
918 
919         if (msg->msg_flags & MSG_OOB)
920                 return -EOPNOTSUPP;
921 
922         /* SOCK_SEQPACKET: we do not support segmented records */
923         if (sk->sk_type == SOCK_SEQPACKET && !(msg->msg_flags & MSG_EOR))
924                 return -EOPNOTSUPP;
925 
926         lock_sock(sk);
927 
928         if (sk->sk_shutdown & SEND_SHUTDOWN) {
929                 err = -EPIPE;
930                 goto out;
931         }
932 
933         /* Return if the socket is not in connected state */
934         if (sk->sk_state != IUCV_CONNECTED) {
935                 err = -ENOTCONN;
936                 goto out;
937         }
938 
939         /* initialize defaults */
940         cmsg_done   = 0;        /* check for duplicate headers */
941 
942         /* iterate over control messages */
943         for_each_cmsghdr(cmsg, msg) {
944                 if (!CMSG_OK(msg, cmsg)) {
945                         err = -EINVAL;
946                         goto out;
947                 }
948 
949                 if (cmsg->cmsg_level != SOL_IUCV)
950                         continue;
951 
952                 if (cmsg->cmsg_type & cmsg_done) {
953                         err = -EINVAL;
954                         goto out;
955                 }
956                 cmsg_done |= cmsg->cmsg_type;
957 
958                 switch (cmsg->cmsg_type) {
959                 case SCM_IUCV_TRGCLS:
960                         if (cmsg->cmsg_len != CMSG_LEN(TRGCLS_SIZE)) {
961                                 err = -EINVAL;
962                                 goto out;
963                         }
964 
965                         /* set iucv message target class */
966                         memcpy(&txmsg.class,
967                                 (void *) CMSG_DATA(cmsg), TRGCLS_SIZE);
968 
969                         break;
970 
971                 default:
972                         err = -EINVAL;
973                         goto out;
974                 }
975         }
976 
977         /* allocate one skb for each iucv message:
978          * this is fine for SOCK_SEQPACKET (unless we want to support
979          * segmented records using the MSG_EOR flag), but
980          * for SOCK_STREAM we might want to improve it in future */
981         if (iucv->transport == AF_IUCV_TRANS_HIPER) {
982                 headroom = sizeof(struct af_iucv_trans_hdr) +
983                            LL_RESERVED_SPACE(iucv->hs_dev);
984                 linear = min(len, PAGE_SIZE - headroom);
985         } else {
986                 if (len < PAGE_SIZE) {
987                         linear = len;
988                 } else {
989                         /* In nonlinear "classic" iucv skb,
990                          * reserve space for iucv_array
991                          */
992                         headroom = sizeof(struct iucv_array) *
993                                    (MAX_SKB_FRAGS + 1);
994                         linear = PAGE_SIZE - headroom;
995                 }
996         }
997         skb = sock_alloc_send_pskb(sk, headroom + linear, len - linear,
998                                    noblock, &err, 0);
999         if (!skb)
1000                 goto out;
1001         if (headroom)
1002                 skb_reserve(skb, headroom);
1003         skb_put(skb, linear);
1004         skb->len = len;
1005         skb->data_len = len - linear;
1006         err = skb_copy_datagram_from_iter(skb, 0, &msg->msg_iter, len);
1007         if (err)
1008                 goto fail;
1009 
1010         /* wait if outstanding messages for iucv path has reached */
1011         timeo = sock_sndtimeo(sk, noblock);
1012         err = iucv_sock_wait(sk, iucv_below_msglim(sk), timeo);
1013         if (err)
1014                 goto fail;
1015 
1016         /* return -ECONNRESET if the socket is no longer connected */
1017         if (sk->sk_state != IUCV_CONNECTED) {
1018                 err = -ECONNRESET;
1019                 goto fail;
1020         }
1021 
1022         /* increment and save iucv message tag for msg_completion cbk */
1023         txmsg.tag = iucv->send_tag++;
1024         IUCV_SKB_CB(skb)->tag = txmsg.tag;
1025 
1026         if (iucv->transport == AF_IUCV_TRANS_HIPER) {
1027                 atomic_inc(&iucv->msg_sent);
1028                 err = afiucv_hs_send(&txmsg, sk, skb, 0);
1029                 if (err) {
1030                         atomic_dec(&iucv->msg_sent);
1031                         goto out;
1032                 }
1033         } else { /* Classic VM IUCV transport */
1034                 skb_queue_tail(&iucv->send_skb_q, skb);
1035                 atomic_inc(&iucv->skbs_in_xmit);
1036 
1037                 if (((iucv->path->flags & IUCV_IPRMDATA) & iucv->flags) &&
1038                     skb->len <= 7) {
1039                         err = iucv_send_iprm(iucv->path, &txmsg, skb);
1040 
1041                         /* on success: there is no message_complete callback */
1042                         /* for an IPRMDATA msg; remove skb from send queue   */
1043                         if (err == 0) {
1044                                 atomic_dec(&iucv->skbs_in_xmit);
1045                                 skb_unlink(skb, &iucv->send_skb_q);
1046                                 consume_skb(skb);
1047                         }
1048 
1049                         /* this error should never happen since the     */
1050                         /* IUCV_IPRMDATA path flag is set... sever path */
1051                         if (err == 0x15) {
1052                                 pr_iucv->path_sever(iucv->path, NULL);
1053                                 atomic_dec(&iucv->skbs_in_xmit);
1054                                 skb_unlink(skb, &iucv->send_skb_q);
1055                                 err = -EPIPE;
1056                                 goto fail;
1057                         }
1058                 } else if (skb_is_nonlinear(skb)) {
1059                         struct iucv_array *iba = (struct iucv_array *)skb->head;
1060                         int i;
1061 
1062                         /* skip iucv_array lying in the headroom */
1063                         iba[0].address = virt_to_dma32(skb->data);
1064                         iba[0].length = (u32)skb_headlen(skb);
1065                         for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
1066                                 skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
1067 
1068                                 iba[i + 1].address = virt_to_dma32(skb_frag_address(frag));
1069                                 iba[i + 1].length = (u32)skb_frag_size(frag);
1070                         }
1071                         err = pr_iucv->message_send(iucv->path, &txmsg,
1072                                                     IUCV_IPBUFLST, 0,
1073                                                     (void *)iba, skb->len);
1074                 } else { /* non-IPRM Linear skb */
1075                         err = pr_iucv->message_send(iucv->path, &txmsg,
1076                                         0, 0, (void *)skb->data, skb->len);
1077                 }
1078                 if (err) {
1079                         if (err == 3) {
1080                                 user_id[8] = 0;
1081                                 memcpy(user_id, iucv->dst_user_id, 8);
1082                                 appl_id[8] = 0;
1083                                 memcpy(appl_id, iucv->dst_name, 8);
1084                                 pr_err(
1085                 "Application %s on z/VM guest %s exceeds message limit\n",
1086                                         appl_id, user_id);
1087                                 err = -EAGAIN;
1088                         } else {
1089                                 err = -EPIPE;
1090                         }
1091 
1092                         atomic_dec(&iucv->skbs_in_xmit);
1093                         skb_unlink(skb, &iucv->send_skb_q);
1094                         goto fail;
1095                 }
1096         }
1097 
1098         release_sock(sk);
1099         return len;
1100 
1101 fail:
1102         kfree_skb(skb);
1103 out:
1104         release_sock(sk);
1105         return err;
1106 }
1107 
1108 static struct sk_buff *alloc_iucv_recv_skb(unsigned long len)
1109 {
1110         size_t headroom, linear;
1111         struct sk_buff *skb;
1112         int err;
1113 
1114         if (len < PAGE_SIZE) {
1115                 headroom = 0;
1116                 linear = len;
1117         } else {
1118                 headroom = sizeof(struct iucv_array) * (MAX_SKB_FRAGS + 1);
1119                 linear = PAGE_SIZE - headroom;
1120         }
1121         skb = alloc_skb_with_frags(headroom + linear, len - linear,
1122                                    0, &err, GFP_ATOMIC | GFP_DMA);
1123         WARN_ONCE(!skb,
1124                   "alloc of recv iucv skb len=%lu failed with errcode=%d\n",
1125                   len, err);
1126         if (skb) {
1127                 if (headroom)
1128                         skb_reserve(skb, headroom);
1129                 skb_put(skb, linear);
1130                 skb->len = len;
1131                 skb->data_len = len - linear;
1132         }
1133         return skb;
1134 }
1135 
1136 /* iucv_process_message() - Receive a single outstanding IUCV message
1137  *
1138  * Locking: must be called with message_q.lock held
1139  */
1140 static void iucv_process_message(struct sock *sk, struct sk_buff *skb,
1141                                  struct iucv_path *path,
1142                                  struct iucv_message *msg)
1143 {
1144         int rc;
1145         unsigned int len;
1146 
1147         len = iucv_msg_length(msg);
1148 
1149         /* store msg target class in the second 4 bytes of skb ctrl buffer */
1150         /* Note: the first 4 bytes are reserved for msg tag */
1151         IUCV_SKB_CB(skb)->class = msg->class;
1152 
1153         /* check for special IPRM messages (e.g. iucv_sock_shutdown) */
1154         if ((msg->flags & IUCV_IPRMDATA) && len > 7) {
1155                 if (memcmp(msg->rmmsg, iprm_shutdown, 8) == 0) {
1156                         skb->data = NULL;
1157                         skb->len = 0;
1158                 }
1159         } else {
1160                 if (skb_is_nonlinear(skb)) {
1161                         struct iucv_array *iba = (struct iucv_array *)skb->head;
1162                         int i;
1163 
1164                         iba[0].address = virt_to_dma32(skb->data);
1165                         iba[0].length = (u32)skb_headlen(skb);
1166                         for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
1167                                 skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
1168 
1169                                 iba[i + 1].address = virt_to_dma32(skb_frag_address(frag));
1170                                 iba[i + 1].length = (u32)skb_frag_size(frag);
1171                         }
1172                         rc = pr_iucv->message_receive(path, msg,
1173                                               IUCV_IPBUFLST,
1174                                               (void *)iba, len, NULL);
1175                 } else {
1176                         rc = pr_iucv->message_receive(path, msg,
1177                                               msg->flags & IUCV_IPRMDATA,
1178                                               skb->data, len, NULL);
1179                 }
1180                 if (rc) {
1181                         kfree_skb(skb);
1182                         return;
1183                 }
1184                 WARN_ON_ONCE(skb->len != len);
1185         }
1186 
1187         IUCV_SKB_CB(skb)->offset = 0;
1188         if (sk_filter(sk, skb)) {
1189                 atomic_inc(&sk->sk_drops);      /* skb rejected by filter */
1190                 kfree_skb(skb);
1191                 return;
1192         }
1193         if (__sock_queue_rcv_skb(sk, skb))      /* handle rcv queue full */
1194                 skb_queue_tail(&iucv_sk(sk)->backlog_skb_q, skb);
1195 }
1196 
1197 /* iucv_process_message_q() - Process outstanding IUCV messages
1198  *
1199  * Locking: must be called with message_q.lock held
1200  */
1201 static void iucv_process_message_q(struct sock *sk)
1202 {
1203         struct iucv_sock *iucv = iucv_sk(sk);
1204         struct sk_buff *skb;
1205         struct sock_msg_q *p, *n;
1206 
1207         list_for_each_entry_safe(p, n, &iucv->message_q.list, list) {
1208                 skb = alloc_iucv_recv_skb(iucv_msg_length(&p->msg));
1209                 if (!skb)
1210                         break;
1211                 iucv_process_message(sk, skb, p->path, &p->msg);
1212                 list_del(&p->list);
1213                 kfree(p);
1214                 if (!skb_queue_empty(&iucv->backlog_skb_q))
1215                         break;
1216         }
1217 }
1218 
1219 static int iucv_sock_recvmsg(struct socket *sock, struct msghdr *msg,
1220                              size_t len, int flags)
1221 {
1222         struct sock *sk = sock->sk;
1223         struct iucv_sock *iucv = iucv_sk(sk);
1224         unsigned int copied, rlen;
1225         struct sk_buff *skb, *rskb, *cskb;
1226         int err = 0;
1227         u32 offset;
1228 
1229         if ((sk->sk_state == IUCV_DISCONN) &&
1230             skb_queue_empty(&iucv->backlog_skb_q) &&
1231             skb_queue_empty(&sk->sk_receive_queue) &&
1232             list_empty(&iucv->message_q.list))
1233                 return 0;
1234 
1235         if (flags & (MSG_OOB))
1236                 return -EOPNOTSUPP;
1237 
1238         /* receive/dequeue next skb:
1239          * the function understands MSG_PEEK and, thus, does not dequeue skb */
1240         skb = skb_recv_datagram(sk, flags, &err);
1241         if (!skb) {
1242                 if (sk->sk_shutdown & RCV_SHUTDOWN)
1243                         return 0;
1244                 return err;
1245         }
1246 
1247         offset = IUCV_SKB_CB(skb)->offset;
1248         rlen   = skb->len - offset;             /* real length of skb */
1249         copied = min_t(unsigned int, rlen, len);
1250         if (!rlen)
1251                 sk->sk_shutdown = sk->sk_shutdown | RCV_SHUTDOWN;
1252 
1253         cskb = skb;
1254         if (skb_copy_datagram_msg(cskb, offset, msg, copied)) {
1255                 if (!(flags & MSG_PEEK))
1256                         skb_queue_head(&sk->sk_receive_queue, skb);
1257                 return -EFAULT;
1258         }
1259 
1260         /* SOCK_SEQPACKET: set MSG_TRUNC if recv buf size is too small */
1261         if (sk->sk_type == SOCK_SEQPACKET) {
1262                 if (copied < rlen)
1263                         msg->msg_flags |= MSG_TRUNC;
1264                 /* each iucv message contains a complete record */
1265                 msg->msg_flags |= MSG_EOR;
1266         }
1267 
1268         /* create control message to store iucv msg target class:
1269          * get the trgcls from the control buffer of the skb due to
1270          * fragmentation of original iucv message. */
1271         err = put_cmsg(msg, SOL_IUCV, SCM_IUCV_TRGCLS,
1272                        sizeof(IUCV_SKB_CB(skb)->class),
1273                        (void *)&IUCV_SKB_CB(skb)->class);
1274         if (err) {
1275                 if (!(flags & MSG_PEEK))
1276                         skb_queue_head(&sk->sk_receive_queue, skb);
1277                 return err;
1278         }
1279 
1280         /* Mark read part of skb as used */
1281         if (!(flags & MSG_PEEK)) {
1282 
1283                 /* SOCK_STREAM: re-queue skb if it contains unreceived data */
1284                 if (sk->sk_type == SOCK_STREAM) {
1285                         if (copied < rlen) {
1286                                 IUCV_SKB_CB(skb)->offset = offset + copied;
1287                                 skb_queue_head(&sk->sk_receive_queue, skb);
1288                                 goto done;
1289                         }
1290                 }
1291 
1292                 consume_skb(skb);
1293                 if (iucv->transport == AF_IUCV_TRANS_HIPER) {
1294                         atomic_inc(&iucv->msg_recv);
1295                         if (atomic_read(&iucv->msg_recv) > iucv->msglimit) {
1296                                 WARN_ON(1);
1297                                 iucv_sock_close(sk);
1298                                 return -EFAULT;
1299                         }
1300                 }
1301 
1302                 /* Queue backlog skbs */
1303                 spin_lock_bh(&iucv->message_q.lock);
1304                 rskb = skb_dequeue(&iucv->backlog_skb_q);
1305                 while (rskb) {
1306                         IUCV_SKB_CB(rskb)->offset = 0;
1307                         if (__sock_queue_rcv_skb(sk, rskb)) {
1308                                 /* handle rcv queue full */
1309                                 skb_queue_head(&iucv->backlog_skb_q,
1310                                                 rskb);
1311                                 break;
1312                         }
1313                         rskb = skb_dequeue(&iucv->backlog_skb_q);
1314                 }
1315                 if (skb_queue_empty(&iucv->backlog_skb_q)) {
1316                         if (!list_empty(&iucv->message_q.list))
1317                                 iucv_process_message_q(sk);
1318                         if (atomic_read(&iucv->msg_recv) >=
1319                                                         iucv->msglimit / 2) {
1320                                 err = iucv_send_ctrl(sk, AF_IUCV_FLAG_WIN);
1321                                 if (err) {
1322                                         sk->sk_state = IUCV_DISCONN;
1323                                         sk->sk_state_change(sk);
1324                                 }
1325                         }
1326                 }
1327                 spin_unlock_bh(&iucv->message_q.lock);
1328         }
1329 
1330 done:
1331         /* SOCK_SEQPACKET: return real length if MSG_TRUNC is set */
1332         if (sk->sk_type == SOCK_SEQPACKET && (flags & MSG_TRUNC))
1333                 copied = rlen;
1334 
1335         return copied;
1336 }
1337 
1338 static inline __poll_t iucv_accept_poll(struct sock *parent)
1339 {
1340         struct iucv_sock *isk, *n;
1341         struct sock *sk;
1342 
1343         list_for_each_entry_safe(isk, n, &iucv_sk(parent)->accept_q, accept_q) {
1344                 sk = (struct sock *) isk;
1345 
1346                 if (sk->sk_state == IUCV_CONNECTED)
1347                         return EPOLLIN | EPOLLRDNORM;
1348         }
1349 
1350         return 0;
1351 }
1352 
1353 static __poll_t iucv_sock_poll(struct file *file, struct socket *sock,
1354                                poll_table *wait)
1355 {
1356         struct sock *sk = sock->sk;
1357         __poll_t mask = 0;
1358 
1359         sock_poll_wait(file, sock, wait);
1360 
1361         if (sk->sk_state == IUCV_LISTEN)
1362                 return iucv_accept_poll(sk);
1363 
1364         if (sk->sk_err || !skb_queue_empty(&sk->sk_error_queue))
1365                 mask |= EPOLLERR |
1366                         (sock_flag(sk, SOCK_SELECT_ERR_QUEUE) ? EPOLLPRI : 0);
1367 
1368         if (sk->sk_shutdown & RCV_SHUTDOWN)
1369                 mask |= EPOLLRDHUP;
1370 
1371         if (sk->sk_shutdown == SHUTDOWN_MASK)
1372                 mask |= EPOLLHUP;
1373 
1374         if (!skb_queue_empty(&sk->sk_receive_queue) ||
1375             (sk->sk_shutdown & RCV_SHUTDOWN))
1376                 mask |= EPOLLIN | EPOLLRDNORM;
1377 
1378         if (sk->sk_state == IUCV_CLOSED)
1379                 mask |= EPOLLHUP;
1380 
1381         if (sk->sk_state == IUCV_DISCONN)
1382                 mask |= EPOLLIN;
1383 
1384         if (sock_writeable(sk) && iucv_below_msglim(sk))
1385                 mask |= EPOLLOUT | EPOLLWRNORM | EPOLLWRBAND;
1386         else
1387                 sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
1388 
1389         return mask;
1390 }
1391 
1392 static int iucv_sock_shutdown(struct socket *sock, int how)
1393 {
1394         struct sock *sk = sock->sk;
1395         struct iucv_sock *iucv = iucv_sk(sk);
1396         struct iucv_message txmsg;
1397         int err = 0;
1398 
1399         how++;
1400 
1401         if ((how & ~SHUTDOWN_MASK) || !how)
1402                 return -EINVAL;
1403 
1404         lock_sock(sk);
1405         switch (sk->sk_state) {
1406         case IUCV_LISTEN:
1407         case IUCV_DISCONN:
1408         case IUCV_CLOSING:
1409         case IUCV_CLOSED:
1410                 err = -ENOTCONN;
1411                 goto fail;
1412         default:
1413                 break;
1414         }
1415 
1416         if ((how == SEND_SHUTDOWN || how == SHUTDOWN_MASK) &&
1417             sk->sk_state == IUCV_CONNECTED) {
1418                 if (iucv->transport == AF_IUCV_TRANS_IUCV) {
1419                         txmsg.class = 0;
1420                         txmsg.tag = 0;
1421                         err = pr_iucv->message_send(iucv->path, &txmsg,
1422                                 IUCV_IPRMDATA, 0, (void *) iprm_shutdown, 8);
1423                         if (err) {
1424                                 switch (err) {
1425                                 case 1:
1426                                         err = -ENOTCONN;
1427                                         break;
1428                                 case 2:
1429                                         err = -ECONNRESET;
1430                                         break;
1431                                 default:
1432                                         err = -ENOTCONN;
1433                                         break;
1434                                 }
1435                         }
1436                 } else
1437                         iucv_send_ctrl(sk, AF_IUCV_FLAG_SHT);
1438         }
1439 
1440         sk->sk_shutdown |= how;
1441         if (how == RCV_SHUTDOWN || how == SHUTDOWN_MASK) {
1442                 if ((iucv->transport == AF_IUCV_TRANS_IUCV) &&
1443                     iucv->path) {
1444                         err = pr_iucv->path_quiesce(iucv->path, NULL);
1445                         if (err)
1446                                 err = -ENOTCONN;
1447 /*                      skb_queue_purge(&sk->sk_receive_queue); */
1448                 }
1449                 skb_queue_purge(&sk->sk_receive_queue);
1450         }
1451 
1452         /* Wake up anyone sleeping in poll */
1453         sk->sk_state_change(sk);
1454 
1455 fail:
1456         release_sock(sk);
1457         return err;
1458 }
1459 
1460 static int iucv_sock_release(struct socket *sock)
1461 {
1462         struct sock *sk = sock->sk;
1463         int err = 0;
1464 
1465         if (!sk)
1466                 return 0;
1467 
1468         iucv_sock_close(sk);
1469 
1470         sock_orphan(sk);
1471         iucv_sock_kill(sk);
1472         return err;
1473 }
1474 
1475 /* getsockopt and setsockopt */
1476 static int iucv_sock_setsockopt(struct socket *sock, int level, int optname,
1477                                 sockptr_t optval, unsigned int optlen)
1478 {
1479         struct sock *sk = sock->sk;
1480         struct iucv_sock *iucv = iucv_sk(sk);
1481         int val;
1482         int rc;
1483 
1484         if (level != SOL_IUCV)
1485                 return -ENOPROTOOPT;
1486 
1487         if (optlen < sizeof(int))
1488                 return -EINVAL;
1489 
1490         if (copy_from_sockptr(&val, optval, sizeof(int)))
1491                 return -EFAULT;
1492 
1493         rc = 0;
1494 
1495         lock_sock(sk);
1496         switch (optname) {
1497         case SO_IPRMDATA_MSG:
1498                 if (val)
1499                         iucv->flags |= IUCV_IPRMDATA;
1500                 else
1501                         iucv->flags &= ~IUCV_IPRMDATA;
1502                 break;
1503         case SO_MSGLIMIT:
1504                 switch (sk->sk_state) {
1505                 case IUCV_OPEN:
1506                 case IUCV_BOUND:
1507                         if (val < 1 || val > U16_MAX)
1508                                 rc = -EINVAL;
1509                         else
1510                                 iucv->msglimit = val;
1511                         break;
1512                 default:
1513                         rc = -EINVAL;
1514                         break;
1515                 }
1516                 break;
1517         default:
1518                 rc = -ENOPROTOOPT;
1519                 break;
1520         }
1521         release_sock(sk);
1522 
1523         return rc;
1524 }
1525 
1526 static int iucv_sock_getsockopt(struct socket *sock, int level, int optname,
1527                                 char __user *optval, int __user *optlen)
1528 {
1529         struct sock *sk = sock->sk;
1530         struct iucv_sock *iucv = iucv_sk(sk);
1531         unsigned int val;
1532         int len;
1533 
1534         if (level != SOL_IUCV)
1535                 return -ENOPROTOOPT;
1536 
1537         if (get_user(len, optlen))
1538                 return -EFAULT;
1539 
1540         if (len < 0)
1541                 return -EINVAL;
1542 
1543         len = min_t(unsigned int, len, sizeof(int));
1544 
1545         switch (optname) {
1546         case SO_IPRMDATA_MSG:
1547                 val = (iucv->flags & IUCV_IPRMDATA) ? 1 : 0;
1548                 break;
1549         case SO_MSGLIMIT:
1550                 lock_sock(sk);
1551                 val = (iucv->path != NULL) ? iucv->path->msglim /* connected */
1552                                            : iucv->msglimit;    /* default */
1553                 release_sock(sk);
1554                 break;
1555         case SO_MSGSIZE:
1556                 if (sk->sk_state == IUCV_OPEN)
1557                         return -EBADFD;
1558                 val = (iucv->hs_dev) ? iucv->hs_dev->mtu -
1559                                 sizeof(struct af_iucv_trans_hdr) - ETH_HLEN :
1560                                 0x7fffffff;
1561                 break;
1562         default:
1563                 return -ENOPROTOOPT;
1564         }
1565 
1566         if (put_user(len, optlen))
1567                 return -EFAULT;
1568         if (copy_to_user(optval, &val, len))
1569                 return -EFAULT;
1570 
1571         return 0;
1572 }
1573 
1574 
1575 /* Callback wrappers - called from iucv base support */
1576 static int iucv_callback_connreq(struct iucv_path *path,
1577                                  u8 ipvmid[8], u8 ipuser[16])
1578 {
1579         unsigned char user_data[16];
1580         unsigned char nuser_data[16];
1581         unsigned char src_name[8];
1582         struct sock *sk, *nsk;
1583         struct iucv_sock *iucv, *niucv;
1584         int err;
1585 
1586         memcpy(src_name, ipuser, 8);
1587         EBCASC(src_name, 8);
1588         /* Find out if this path belongs to af_iucv. */
1589         read_lock(&iucv_sk_list.lock);
1590         iucv = NULL;
1591         sk = NULL;
1592         sk_for_each(sk, &iucv_sk_list.head)
1593                 if (sk->sk_state == IUCV_LISTEN &&
1594                     !memcmp(&iucv_sk(sk)->src_name, src_name, 8)) {
1595                         /*
1596                          * Found a listening socket with
1597                          * src_name == ipuser[0-7].
1598                          */
1599                         iucv = iucv_sk(sk);
1600                         break;
1601                 }
1602         read_unlock(&iucv_sk_list.lock);
1603         if (!iucv)
1604                 /* No socket found, not one of our paths. */
1605                 return -EINVAL;
1606 
1607         bh_lock_sock(sk);
1608 
1609         /* Check if parent socket is listening */
1610         low_nmcpy(user_data, iucv->src_name);
1611         high_nmcpy(user_data, iucv->dst_name);
1612         ASCEBC(user_data, sizeof(user_data));
1613         if (sk->sk_state != IUCV_LISTEN) {
1614                 err = pr_iucv->path_sever(path, user_data);
1615                 iucv_path_free(path);
1616                 goto fail;
1617         }
1618 
1619         /* Check for backlog size */
1620         if (sk_acceptq_is_full(sk)) {
1621                 err = pr_iucv->path_sever(path, user_data);
1622                 iucv_path_free(path);
1623                 goto fail;
1624         }
1625 
1626         /* Create the new socket */
1627         nsk = iucv_sock_alloc(NULL, sk->sk_protocol, GFP_ATOMIC, 0);
1628         if (!nsk) {
1629                 err = pr_iucv->path_sever(path, user_data);
1630                 iucv_path_free(path);
1631                 goto fail;
1632         }
1633 
1634         niucv = iucv_sk(nsk);
1635         iucv_sock_init(nsk, sk);
1636         niucv->transport = AF_IUCV_TRANS_IUCV;
1637         nsk->sk_allocation |= GFP_DMA;
1638 
1639         /* Set the new iucv_sock */
1640         memcpy(niucv->dst_name, ipuser + 8, 8);
1641         EBCASC(niucv->dst_name, 8);
1642         memcpy(niucv->dst_user_id, ipvmid, 8);
1643         memcpy(niucv->src_name, iucv->src_name, 8);
1644         memcpy(niucv->src_user_id, iucv->src_user_id, 8);
1645         niucv->path = path;
1646 
1647         /* Call iucv_accept */
1648         high_nmcpy(nuser_data, ipuser + 8);
1649         memcpy(nuser_data + 8, niucv->src_name, 8);
1650         ASCEBC(nuser_data + 8, 8);
1651 
1652         /* set message limit for path based on msglimit of accepting socket */
1653         niucv->msglimit = iucv->msglimit;
1654         path->msglim = iucv->msglimit;
1655         err = pr_iucv->path_accept(path, &af_iucv_handler, nuser_data, nsk);
1656         if (err) {
1657                 iucv_sever_path(nsk, 1);
1658                 iucv_sock_kill(nsk);
1659                 goto fail;
1660         }
1661 
1662         iucv_accept_enqueue(sk, nsk);
1663 
1664         /* Wake up accept */
1665         nsk->sk_state = IUCV_CONNECTED;
1666         sk->sk_data_ready(sk);
1667         err = 0;
1668 fail:
1669         bh_unlock_sock(sk);
1670         return 0;
1671 }
1672 
1673 static void iucv_callback_connack(struct iucv_path *path, u8 ipuser[16])
1674 {
1675         struct sock *sk = path->private;
1676 
1677         sk->sk_state = IUCV_CONNECTED;
1678         sk->sk_state_change(sk);
1679 }
1680 
1681 static void iucv_callback_rx(struct iucv_path *path, struct iucv_message *msg)
1682 {
1683         struct sock *sk = path->private;
1684         struct iucv_sock *iucv = iucv_sk(sk);
1685         struct sk_buff *skb;
1686         struct sock_msg_q *save_msg;
1687         int len;
1688 
1689         if (sk->sk_shutdown & RCV_SHUTDOWN) {
1690                 pr_iucv->message_reject(path, msg);
1691                 return;
1692         }
1693 
1694         spin_lock(&iucv->message_q.lock);
1695 
1696         if (!list_empty(&iucv->message_q.list) ||
1697             !skb_queue_empty(&iucv->backlog_skb_q))
1698                 goto save_message;
1699 
1700         len = atomic_read(&sk->sk_rmem_alloc);
1701         len += SKB_TRUESIZE(iucv_msg_length(msg));
1702         if (len > sk->sk_rcvbuf)
1703                 goto save_message;
1704 
1705         skb = alloc_iucv_recv_skb(iucv_msg_length(msg));
1706         if (!skb)
1707                 goto save_message;
1708 
1709         iucv_process_message(sk, skb, path, msg);
1710         goto out_unlock;
1711 
1712 save_message:
1713         save_msg = kzalloc(sizeof(struct sock_msg_q), GFP_ATOMIC | GFP_DMA);
1714         if (!save_msg)
1715                 goto out_unlock;
1716         save_msg->path = path;
1717         save_msg->msg = *msg;
1718 
1719         list_add_tail(&save_msg->list, &iucv->message_q.list);
1720 
1721 out_unlock:
1722         spin_unlock(&iucv->message_q.lock);
1723 }
1724 
1725 static void iucv_callback_txdone(struct iucv_path *path,
1726                                  struct iucv_message *msg)
1727 {
1728         struct sock *sk = path->private;
1729         struct sk_buff *this = NULL;
1730         struct sk_buff_head *list;
1731         struct sk_buff *list_skb;
1732         struct iucv_sock *iucv;
1733         unsigned long flags;
1734 
1735         iucv = iucv_sk(sk);
1736         list = &iucv->send_skb_q;
1737 
1738         bh_lock_sock(sk);
1739 
1740         spin_lock_irqsave(&list->lock, flags);
1741         skb_queue_walk(list, list_skb) {
1742                 if (msg->tag == IUCV_SKB_CB(list_skb)->tag) {
1743                         this = list_skb;
1744                         break;
1745                 }
1746         }
1747         if (this) {
1748                 atomic_dec(&iucv->skbs_in_xmit);
1749                 __skb_unlink(this, list);
1750         }
1751 
1752         spin_unlock_irqrestore(&list->lock, flags);
1753 
1754         if (this) {
1755                 consume_skb(this);
1756                 /* wake up any process waiting for sending */
1757                 iucv_sock_wake_msglim(sk);
1758         }
1759 
1760         if (sk->sk_state == IUCV_CLOSING) {
1761                 if (atomic_read(&iucv->skbs_in_xmit) == 0) {
1762                         sk->sk_state = IUCV_CLOSED;
1763                         sk->sk_state_change(sk);
1764                 }
1765         }
1766         bh_unlock_sock(sk);
1767 
1768 }
1769 
1770 static void iucv_callback_connrej(struct iucv_path *path, u8 ipuser[16])
1771 {
1772         struct sock *sk = path->private;
1773 
1774         if (sk->sk_state == IUCV_CLOSED)
1775                 return;
1776 
1777         bh_lock_sock(sk);
1778         iucv_sever_path(sk, 1);
1779         sk->sk_state = IUCV_DISCONN;
1780 
1781         sk->sk_state_change(sk);
1782         bh_unlock_sock(sk);
1783 }
1784 
1785 /* called if the other communication side shuts down its RECV direction;
1786  * in turn, the callback sets SEND_SHUTDOWN to disable sending of data.
1787  */
1788 static void iucv_callback_shutdown(struct iucv_path *path, u8 ipuser[16])
1789 {
1790         struct sock *sk = path->private;
1791 
1792         bh_lock_sock(sk);
1793         if (sk->sk_state != IUCV_CLOSED) {
1794                 sk->sk_shutdown |= SEND_SHUTDOWN;
1795                 sk->sk_state_change(sk);
1796         }
1797         bh_unlock_sock(sk);
1798 }
1799 
1800 static struct iucv_handler af_iucv_handler = {
1801         .path_pending           = iucv_callback_connreq,
1802         .path_complete          = iucv_callback_connack,
1803         .path_severed           = iucv_callback_connrej,
1804         .message_pending        = iucv_callback_rx,
1805         .message_complete       = iucv_callback_txdone,
1806         .path_quiesced          = iucv_callback_shutdown,
1807 };
1808 
1809 /***************** HiperSockets transport callbacks ********************/
1810 static void afiucv_swap_src_dest(struct sk_buff *skb)
1811 {
1812         struct af_iucv_trans_hdr *trans_hdr = iucv_trans_hdr(skb);
1813         char tmpID[8];
1814         char tmpName[8];
1815 
1816         ASCEBC(trans_hdr->destUserID, sizeof(trans_hdr->destUserID));
1817         ASCEBC(trans_hdr->destAppName, sizeof(trans_hdr->destAppName));
1818         ASCEBC(trans_hdr->srcUserID, sizeof(trans_hdr->srcUserID));
1819         ASCEBC(trans_hdr->srcAppName, sizeof(trans_hdr->srcAppName));
1820         memcpy(tmpID, trans_hdr->srcUserID, 8);
1821         memcpy(tmpName, trans_hdr->srcAppName, 8);
1822         memcpy(trans_hdr->srcUserID, trans_hdr->destUserID, 8);
1823         memcpy(trans_hdr->srcAppName, trans_hdr->destAppName, 8);
1824         memcpy(trans_hdr->destUserID, tmpID, 8);
1825         memcpy(trans_hdr->destAppName, tmpName, 8);
1826         skb_push(skb, ETH_HLEN);
1827         memset(skb->data, 0, ETH_HLEN);
1828 }
1829 
1830 /*
1831  * afiucv_hs_callback_syn - react on received SYN
1832  */
1833 static int afiucv_hs_callback_syn(struct sock *sk, struct sk_buff *skb)
1834 {
1835         struct af_iucv_trans_hdr *trans_hdr = iucv_trans_hdr(skb);
1836         struct sock *nsk;
1837         struct iucv_sock *iucv, *niucv;
1838         int err;
1839 
1840         iucv = iucv_sk(sk);
1841         if (!iucv) {
1842                 /* no sock - connection refused */
1843                 afiucv_swap_src_dest(skb);
1844                 trans_hdr->flags = AF_IUCV_FLAG_SYN | AF_IUCV_FLAG_FIN;
1845                 err = dev_queue_xmit(skb);
1846                 goto out;
1847         }
1848 
1849         nsk = iucv_sock_alloc(NULL, sk->sk_protocol, GFP_ATOMIC, 0);
1850         bh_lock_sock(sk);
1851         if ((sk->sk_state != IUCV_LISTEN) ||
1852             sk_acceptq_is_full(sk) ||
1853             !nsk) {
1854                 /* error on server socket - connection refused */
1855                 afiucv_swap_src_dest(skb);
1856                 trans_hdr->flags = AF_IUCV_FLAG_SYN | AF_IUCV_FLAG_FIN;
1857                 err = dev_queue_xmit(skb);
1858                 iucv_sock_kill(nsk);
1859                 bh_unlock_sock(sk);
1860                 goto out;
1861         }
1862 
1863         niucv = iucv_sk(nsk);
1864         iucv_sock_init(nsk, sk);
1865         niucv->transport = AF_IUCV_TRANS_HIPER;
1866         niucv->msglimit = iucv->msglimit;
1867         if (!trans_hdr->window)
1868                 niucv->msglimit_peer = IUCV_HIPER_MSGLIM_DEFAULT;
1869         else
1870                 niucv->msglimit_peer = trans_hdr->window;
1871         memcpy(niucv->dst_name, trans_hdr->srcAppName, 8);
1872         memcpy(niucv->dst_user_id, trans_hdr->srcUserID, 8);
1873         memcpy(niucv->src_name, iucv->src_name, 8);
1874         memcpy(niucv->src_user_id, iucv->src_user_id, 8);
1875         nsk->sk_bound_dev_if = sk->sk_bound_dev_if;
1876         niucv->hs_dev = iucv->hs_dev;
1877         dev_hold(niucv->hs_dev);
1878         afiucv_swap_src_dest(skb);
1879         trans_hdr->flags = AF_IUCV_FLAG_SYN | AF_IUCV_FLAG_ACK;
1880         trans_hdr->window = niucv->msglimit;
1881         /* if receiver acks the xmit connection is established */
1882         err = dev_queue_xmit(skb);
1883         if (!err) {
1884                 iucv_accept_enqueue(sk, nsk);
1885                 nsk->sk_state = IUCV_CONNECTED;
1886                 sk->sk_data_ready(sk);
1887         } else
1888                 iucv_sock_kill(nsk);
1889         bh_unlock_sock(sk);
1890 
1891 out:
1892         return NET_RX_SUCCESS;
1893 }
1894 
1895 /*
1896  * afiucv_hs_callback_synack() - react on received SYN-ACK
1897  */
1898 static int afiucv_hs_callback_synack(struct sock *sk, struct sk_buff *skb)
1899 {
1900         struct iucv_sock *iucv = iucv_sk(sk);
1901 
1902         if (!iucv || sk->sk_state != IUCV_BOUND) {
1903                 kfree_skb(skb);
1904                 return NET_RX_SUCCESS;
1905         }
1906 
1907         bh_lock_sock(sk);
1908         iucv->msglimit_peer = iucv_trans_hdr(skb)->window;
1909         sk->sk_state = IUCV_CONNECTED;
1910         sk->sk_state_change(sk);
1911         bh_unlock_sock(sk);
1912         consume_skb(skb);
1913         return NET_RX_SUCCESS;
1914 }
1915 
1916 /*
1917  * afiucv_hs_callback_synfin() - react on received SYN_FIN
1918  */
1919 static int afiucv_hs_callback_synfin(struct sock *sk, struct sk_buff *skb)
1920 {
1921         struct iucv_sock *iucv = iucv_sk(sk);
1922 
1923         if (!iucv || sk->sk_state != IUCV_BOUND) {
1924                 kfree_skb(skb);
1925                 return NET_RX_SUCCESS;
1926         }
1927 
1928         bh_lock_sock(sk);
1929         sk->sk_state = IUCV_DISCONN;
1930         sk->sk_state_change(sk);
1931         bh_unlock_sock(sk);
1932         consume_skb(skb);
1933         return NET_RX_SUCCESS;
1934 }
1935 
1936 /*
1937  * afiucv_hs_callback_fin() - react on received FIN
1938  */
1939 static int afiucv_hs_callback_fin(struct sock *sk, struct sk_buff *skb)
1940 {
1941         struct iucv_sock *iucv = iucv_sk(sk);
1942 
1943         /* other end of connection closed */
1944         if (!iucv) {
1945                 kfree_skb(skb);
1946                 return NET_RX_SUCCESS;
1947         }
1948 
1949         bh_lock_sock(sk);
1950         if (sk->sk_state == IUCV_CONNECTED) {
1951                 sk->sk_state = IUCV_DISCONN;
1952                 sk->sk_state_change(sk);
1953         }
1954         bh_unlock_sock(sk);
1955         consume_skb(skb);
1956         return NET_RX_SUCCESS;
1957 }
1958 
1959 /*
1960  * afiucv_hs_callback_win() - react on received WIN
1961  */
1962 static int afiucv_hs_callback_win(struct sock *sk, struct sk_buff *skb)
1963 {
1964         struct iucv_sock *iucv = iucv_sk(sk);
1965 
1966         if (!iucv)
1967                 return NET_RX_SUCCESS;
1968 
1969         if (sk->sk_state != IUCV_CONNECTED)
1970                 return NET_RX_SUCCESS;
1971 
1972         atomic_sub(iucv_trans_hdr(skb)->window, &iucv->msg_sent);
1973         iucv_sock_wake_msglim(sk);
1974         return NET_RX_SUCCESS;
1975 }
1976 
1977 /*
1978  * afiucv_hs_callback_rx() - react on received data
1979  */
1980 static int afiucv_hs_callback_rx(struct sock *sk, struct sk_buff *skb)
1981 {
1982         struct iucv_sock *iucv = iucv_sk(sk);
1983 
1984         if (!iucv) {
1985                 kfree_skb(skb);
1986                 return NET_RX_SUCCESS;
1987         }
1988 
1989         if (sk->sk_state != IUCV_CONNECTED) {
1990                 kfree_skb(skb);
1991                 return NET_RX_SUCCESS;
1992         }
1993 
1994         if (sk->sk_shutdown & RCV_SHUTDOWN) {
1995                 kfree_skb(skb);
1996                 return NET_RX_SUCCESS;
1997         }
1998 
1999         /* write stuff from iucv_msg to skb cb */
2000         skb_pull(skb, sizeof(struct af_iucv_trans_hdr));
2001         skb_reset_transport_header(skb);
2002         skb_reset_network_header(skb);
2003         IUCV_SKB_CB(skb)->offset = 0;
2004         if (sk_filter(sk, skb)) {
2005                 atomic_inc(&sk->sk_drops);      /* skb rejected by filter */
2006                 kfree_skb(skb);
2007                 return NET_RX_SUCCESS;
2008         }
2009 
2010         spin_lock(&iucv->message_q.lock);
2011         if (skb_queue_empty(&iucv->backlog_skb_q)) {
2012                 if (__sock_queue_rcv_skb(sk, skb))
2013                         /* handle rcv queue full */
2014                         skb_queue_tail(&iucv->backlog_skb_q, skb);
2015         } else
2016                 skb_queue_tail(&iucv_sk(sk)->backlog_skb_q, skb);
2017         spin_unlock(&iucv->message_q.lock);
2018         return NET_RX_SUCCESS;
2019 }
2020 
2021 /*
2022  * afiucv_hs_rcv() - base function for arriving data through HiperSockets
2023  *                   transport
2024  *                   called from netif RX softirq
2025  */
2026 static int afiucv_hs_rcv(struct sk_buff *skb, struct net_device *dev,
2027         struct packet_type *pt, struct net_device *orig_dev)
2028 {
2029         struct sock *sk;
2030         struct iucv_sock *iucv;
2031         struct af_iucv_trans_hdr *trans_hdr;
2032         int err = NET_RX_SUCCESS;
2033         char nullstring[8];
2034 
2035         if (!pskb_may_pull(skb, sizeof(*trans_hdr))) {
2036                 kfree_skb(skb);
2037                 return NET_RX_SUCCESS;
2038         }
2039 
2040         trans_hdr = iucv_trans_hdr(skb);
2041         EBCASC(trans_hdr->destAppName, sizeof(trans_hdr->destAppName));
2042         EBCASC(trans_hdr->destUserID, sizeof(trans_hdr->destUserID));
2043         EBCASC(trans_hdr->srcAppName, sizeof(trans_hdr->srcAppName));
2044         EBCASC(trans_hdr->srcUserID, sizeof(trans_hdr->srcUserID));
2045         memset(nullstring, 0, sizeof(nullstring));
2046         iucv = NULL;
2047         sk = NULL;
2048         read_lock(&iucv_sk_list.lock);
2049         sk_for_each(sk, &iucv_sk_list.head) {
2050                 if (trans_hdr->flags == AF_IUCV_FLAG_SYN) {
2051                         if ((!memcmp(&iucv_sk(sk)->src_name,
2052                                      trans_hdr->destAppName, 8)) &&
2053                             (!memcmp(&iucv_sk(sk)->src_user_id,
2054                                      trans_hdr->destUserID, 8)) &&
2055                             (!memcmp(&iucv_sk(sk)->dst_name, nullstring, 8)) &&
2056                             (!memcmp(&iucv_sk(sk)->dst_user_id,
2057                                      nullstring, 8))) {
2058                                 iucv = iucv_sk(sk);
2059                                 break;
2060                         }
2061                 } else {
2062                         if ((!memcmp(&iucv_sk(sk)->src_name,
2063                                      trans_hdr->destAppName, 8)) &&
2064                             (!memcmp(&iucv_sk(sk)->src_user_id,
2065                                      trans_hdr->destUserID, 8)) &&
2066                             (!memcmp(&iucv_sk(sk)->dst_name,
2067                                      trans_hdr->srcAppName, 8)) &&
2068                             (!memcmp(&iucv_sk(sk)->dst_user_id,
2069                                      trans_hdr->srcUserID, 8))) {
2070                                 iucv = iucv_sk(sk);
2071                                 break;
2072                         }
2073                 }
2074         }
2075         read_unlock(&iucv_sk_list.lock);
2076         if (!iucv)
2077                 sk = NULL;
2078 
2079         /* no sock
2080         how should we send with no sock
2081         1) send without sock no send rc checking?
2082         2) introduce default sock to handle this cases
2083 
2084          SYN -> send SYN|ACK in good case, send SYN|FIN in bad case
2085          data -> send FIN
2086          SYN|ACK, SYN|FIN, FIN -> no action? */
2087 
2088         switch (trans_hdr->flags) {
2089         case AF_IUCV_FLAG_SYN:
2090                 /* connect request */
2091                 err = afiucv_hs_callback_syn(sk, skb);
2092                 break;
2093         case (AF_IUCV_FLAG_SYN | AF_IUCV_FLAG_ACK):
2094                 /* connect request confirmed */
2095                 err = afiucv_hs_callback_synack(sk, skb);
2096                 break;
2097         case (AF_IUCV_FLAG_SYN | AF_IUCV_FLAG_FIN):
2098                 /* connect request refused */
2099                 err = afiucv_hs_callback_synfin(sk, skb);
2100                 break;
2101         case (AF_IUCV_FLAG_FIN):
2102                 /* close request */
2103                 err = afiucv_hs_callback_fin(sk, skb);
2104                 break;
2105         case (AF_IUCV_FLAG_WIN):
2106                 err = afiucv_hs_callback_win(sk, skb);
2107                 if (skb->len == sizeof(struct af_iucv_trans_hdr)) {
2108                         consume_skb(skb);
2109                         break;
2110                 }
2111                 fallthrough;    /* and receive non-zero length data */
2112         case (AF_IUCV_FLAG_SHT):
2113                 /* shutdown request */
2114                 fallthrough;    /* and receive zero length data */
2115         case 0:
2116                 /* plain data frame */
2117                 IUCV_SKB_CB(skb)->class = trans_hdr->iucv_hdr.class;
2118                 err = afiucv_hs_callback_rx(sk, skb);
2119                 break;
2120         default:
2121                 kfree_skb(skb);
2122         }
2123 
2124         return err;
2125 }
2126 
2127 /*
2128  * afiucv_hs_callback_txnotify() - handle send notifications from HiperSockets
2129  *                                 transport
2130  */
2131 static void afiucv_hs_callback_txnotify(struct sock *sk, enum iucv_tx_notify n)
2132 {
2133         struct iucv_sock *iucv = iucv_sk(sk);
2134 
2135         if (sock_flag(sk, SOCK_ZAPPED))
2136                 return;
2137 
2138         switch (n) {
2139         case TX_NOTIFY_OK:
2140                 atomic_dec(&iucv->skbs_in_xmit);
2141                 iucv_sock_wake_msglim(sk);
2142                 break;
2143         case TX_NOTIFY_PENDING:
2144                 atomic_inc(&iucv->pendings);
2145                 break;
2146         case TX_NOTIFY_DELAYED_OK:
2147                 atomic_dec(&iucv->skbs_in_xmit);
2148                 if (atomic_dec_return(&iucv->pendings) <= 0)
2149                         iucv_sock_wake_msglim(sk);
2150                 break;
2151         default:
2152                 atomic_dec(&iucv->skbs_in_xmit);
2153                 if (sk->sk_state == IUCV_CONNECTED) {
2154                         sk->sk_state = IUCV_DISCONN;
2155                         sk->sk_state_change(sk);
2156                 }
2157         }
2158 
2159         if (sk->sk_state == IUCV_CLOSING) {
2160                 if (atomic_read(&iucv->skbs_in_xmit) == 0) {
2161                         sk->sk_state = IUCV_CLOSED;
2162                         sk->sk_state_change(sk);
2163                 }
2164         }
2165 }
2166 
2167 /*
2168  * afiucv_netdev_event: handle netdev notifier chain events
2169  */
2170 static int afiucv_netdev_event(struct notifier_block *this,
2171                                unsigned long event, void *ptr)
2172 {
2173         struct net_device *event_dev = netdev_notifier_info_to_dev(ptr);
2174         struct sock *sk;
2175         struct iucv_sock *iucv;
2176 
2177         switch (event) {
2178         case NETDEV_REBOOT:
2179         case NETDEV_GOING_DOWN:
2180                 sk_for_each(sk, &iucv_sk_list.head) {
2181                         iucv = iucv_sk(sk);
2182                         if ((iucv->hs_dev == event_dev) &&
2183                             (sk->sk_state == IUCV_CONNECTED)) {
2184                                 if (event == NETDEV_GOING_DOWN)
2185                                         iucv_send_ctrl(sk, AF_IUCV_FLAG_FIN);
2186                                 sk->sk_state = IUCV_DISCONN;
2187                                 sk->sk_state_change(sk);
2188                         }
2189                 }
2190                 break;
2191         case NETDEV_DOWN:
2192         case NETDEV_UNREGISTER:
2193         default:
2194                 break;
2195         }
2196         return NOTIFY_DONE;
2197 }
2198 
2199 static struct notifier_block afiucv_netdev_notifier = {
2200         .notifier_call = afiucv_netdev_event,
2201 };
2202 
2203 static const struct proto_ops iucv_sock_ops = {
2204         .family         = PF_IUCV,
2205         .owner          = THIS_MODULE,
2206         .release        = iucv_sock_release,
2207         .bind           = iucv_sock_bind,
2208         .connect        = iucv_sock_connect,
2209         .listen         = iucv_sock_listen,
2210         .accept         = iucv_sock_accept,
2211         .getname        = iucv_sock_getname,
2212         .sendmsg        = iucv_sock_sendmsg,
2213         .recvmsg        = iucv_sock_recvmsg,
2214         .poll           = iucv_sock_poll,
2215         .ioctl          = sock_no_ioctl,
2216         .mmap           = sock_no_mmap,
2217         .socketpair     = sock_no_socketpair,
2218         .shutdown       = iucv_sock_shutdown,
2219         .setsockopt     = iucv_sock_setsockopt,
2220         .getsockopt     = iucv_sock_getsockopt,
2221 };
2222 
2223 static int iucv_sock_create(struct net *net, struct socket *sock, int protocol,
2224                             int kern)
2225 {
2226         struct sock *sk;
2227 
2228         if (protocol && protocol != PF_IUCV)
2229                 return -EPROTONOSUPPORT;
2230 
2231         sock->state = SS_UNCONNECTED;
2232 
2233         switch (sock->type) {
2234         case SOCK_STREAM:
2235         case SOCK_SEQPACKET:
2236                 /* currently, proto ops can handle both sk types */
2237                 sock->ops = &iucv_sock_ops;
2238                 break;
2239         default:
2240                 return -ESOCKTNOSUPPORT;
2241         }
2242 
2243         sk = iucv_sock_alloc(sock, protocol, GFP_KERNEL, kern);
2244         if (!sk)
2245                 return -ENOMEM;
2246 
2247         iucv_sock_init(sk, NULL);
2248 
2249         return 0;
2250 }
2251 
2252 static const struct net_proto_family iucv_sock_family_ops = {
2253         .family = AF_IUCV,
2254         .owner  = THIS_MODULE,
2255         .create = iucv_sock_create,
2256 };
2257 
2258 static struct packet_type iucv_packet_type = {
2259         .type = cpu_to_be16(ETH_P_AF_IUCV),
2260         .func = afiucv_hs_rcv,
2261 };
2262 
2263 static int __init afiucv_init(void)
2264 {
2265         int err;
2266 
2267         if (MACHINE_IS_VM && IS_ENABLED(CONFIG_IUCV)) {
2268                 cpcmd("QUERY USERID", iucv_userid, sizeof(iucv_userid), &err);
2269                 if (unlikely(err)) {
2270                         WARN_ON(err);
2271                         err = -EPROTONOSUPPORT;
2272                         goto out;
2273                 }
2274 
2275                 pr_iucv = &iucv_if;
2276         } else {
2277                 memset(&iucv_userid, 0, sizeof(iucv_userid));
2278                 pr_iucv = NULL;
2279         }
2280 
2281         err = proto_register(&iucv_proto, 0);
2282         if (err)
2283                 goto out;
2284         err = sock_register(&iucv_sock_family_ops);
2285         if (err)
2286                 goto out_proto;
2287 
2288         if (pr_iucv) {
2289                 err = pr_iucv->iucv_register(&af_iucv_handler, 0);
2290                 if (err)
2291                         goto out_sock;
2292         }
2293 
2294         err = register_netdevice_notifier(&afiucv_netdev_notifier);
2295         if (err)
2296                 goto out_notifier;
2297 
2298         dev_add_pack(&iucv_packet_type);
2299         return 0;
2300 
2301 out_notifier:
2302         if (pr_iucv)
2303                 pr_iucv->iucv_unregister(&af_iucv_handler, 0);
2304 out_sock:
2305         sock_unregister(PF_IUCV);
2306 out_proto:
2307         proto_unregister(&iucv_proto);
2308 out:
2309         return err;
2310 }
2311 
2312 static void __exit afiucv_exit(void)
2313 {
2314         if (pr_iucv)
2315                 pr_iucv->iucv_unregister(&af_iucv_handler, 0);
2316 
2317         unregister_netdevice_notifier(&afiucv_netdev_notifier);
2318         dev_remove_pack(&iucv_packet_type);
2319         sock_unregister(PF_IUCV);
2320         proto_unregister(&iucv_proto);
2321 }
2322 
2323 module_init(afiucv_init);
2324 module_exit(afiucv_exit);
2325 
2326 MODULE_AUTHOR("Jennifer Hunt <jenhunt@us.ibm.com>");
2327 MODULE_DESCRIPTION("IUCV Sockets ver " VERSION);
2328 MODULE_VERSION(VERSION);
2329 MODULE_LICENSE("GPL");
2330 MODULE_ALIAS_NETPROTO(PF_IUCV);
2331 

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