net/phonet/pep.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * File: pep.c
   4  *
   5  * Phonet pipe protocol end point socket
   6  *
   7  * Copyright (C) 2008 Nokia Corporation.
   8  *
   9  * Author: Rémi Denis-Courmont
  10  */
  11
  12 #include <linux/kernel.h>
  13 #include <linux/sched/signal.h>
  14 #include <linux/slab.h>
  15 #include <linux/socket.h>
  16 #include <net/sock.h>
  17 #include <net/tcp_states.h>
  18 #include <asm/ioctls.h>
  19
  20 #include <linux/phonet.h>
  21 #include <linux/module.h>
  22 #include <net/phonet/phonet.h>
  23 #include <net/phonet/pep.h>
  24 #include <net/phonet/gprs.h>
  25
  26 /* sk_state values:
  27  * TCP_CLOSE            sock not in use yet
  28  * TCP_CLOSE_WAIT       disconnected pipe
  29  * TCP_LISTEN           listening pipe endpoint
  30  * TCP_SYN_RECV         connected pipe in disabled state
  31  * TCP_ESTABLISHED      connected pipe in enabled state
  32  *
  33  * pep_sock locking:
  34  *  - sk_state, hlist: sock lock needed
  35  *  - listener: read only
  36  *  - pipe_handle: read only
  37  */
  38
  39 #define CREDITS_MAX     10
  40 #define CREDITS_THR     7
  41
  42 #define pep_sb_size(s) (((s) + 5) & ~3) /* 2-bytes head, 32-bits aligned */
  43
  44 /* Get the next TLV sub-block. */
  45 static unsigned char *pep_get_sb(struct sk_buff *skb, u8 *ptype, u8 *plen,
  46                                         void *buf)
  47 {
  48         void *data = NULL;
  49         struct {
  50                 u8 sb_type;
  51                 u8 sb_len;
  52         } *ph, h;
  53         int buflen = *plen;
  54
  55         ph = skb_header_pointer(skb, 0, 2, &h);
  56         if (ph == NULL || ph->sb_len < 2 || !pskb_may_pull(skb, ph->sb_len))
  57                 return NULL;
  58         ph->sb_len -= 2;
  59         *ptype = ph->sb_type;
  60         *plen = ph->sb_len;
  61
  62         if (buflen > ph->sb_len)
  63                 buflen = ph->sb_len;
  64         data = skb_header_pointer(skb, 2, buflen, buf);
  65         __skb_pull(skb, 2 + ph->sb_len);
  66         return data;
  67 }
  68
  69 static struct sk_buff *pep_alloc_skb(struct sock *sk, const void *payload,
  70                                         int len, gfp_t priority)
  71 {
  72         struct sk_buff *skb = alloc_skb(MAX_PNPIPE_HEADER + len, priority);
  73         if (!skb)
  74                 return NULL;
  75         skb_set_owner_w(skb, sk);
  76
  77         skb_reserve(skb, MAX_PNPIPE_HEADER);
  78         __skb_put(skb, len);
  79         skb_copy_to_linear_data(skb, payload, len);
  80         __skb_push(skb, sizeof(struct pnpipehdr));
  81         skb_reset_transport_header(skb);
  82         return skb;
  83 }
  84
  85 static int pep_reply(struct sock *sk, struct sk_buff *oskb, u8 code,
  86                         const void *data, int len, gfp_t priority)
  87 {
  88         const struct pnpipehdr *oph = pnp_hdr(oskb);
  89         struct pnpipehdr *ph;
  90         struct sk_buff *skb;
  91         struct sockaddr_pn peer;
  92
  93         skb = pep_alloc_skb(sk, data, len, priority);
  94         if (!skb)
  95                 return -ENOMEM;
  96
  97         ph = pnp_hdr(skb);
  98         ph->utid = oph->utid;
  99         ph->message_id = oph->message_id + 1; /* REQ -> RESP */
 100         ph->pipe_handle = oph->pipe_handle;
 101         ph->error_code = code;
 102
 103         pn_skb_get_src_sockaddr(oskb, &peer);
 104         return pn_skb_send(sk, skb, &peer);
 105 }
 106
 107 static int pep_indicate(struct sock *sk, u8 id, u8 code,
 108                         const void *data, int len, gfp_t priority)
 109 {
 110         struct pep_sock *pn = pep_sk(sk);
 111         struct pnpipehdr *ph;
 112         struct sk_buff *skb;
 113
 114         skb = pep_alloc_skb(sk, data, len, priority);
 115         if (!skb)
 116                 return -ENOMEM;
 117
 118         ph = pnp_hdr(skb);
 119         ph->utid = 0;
 120         ph->message_id = id;
 121         ph->pipe_handle = pn->pipe_handle;
 122         ph->error_code = code;
 123         return pn_skb_send(sk, skb, NULL);
 124 }
 125
 126 #define PAD 0x00
 127
 128 static int pipe_handler_request(struct sock *sk, u8 id, u8 code,
 129                                 const void *data, int len)
 130 {
 131         struct pep_sock *pn = pep_sk(sk);
 132         struct pnpipehdr *ph;
 133         struct sk_buff *skb;
 134
 135         skb = pep_alloc_skb(sk, data, len, GFP_KERNEL);
 136         if (!skb)
 137                 return -ENOMEM;
 138
 139         ph = pnp_hdr(skb);
 140         ph->utid = id; /* whatever */
 141         ph->message_id = id;
 142         ph->pipe_handle = pn->pipe_handle;
 143         ph->error_code = code;
 144         return pn_skb_send(sk, skb, NULL);
 145 }
 146
 147 static int pipe_handler_send_created_ind(struct sock *sk)
 148 {
 149         struct pep_sock *pn = pep_sk(sk);
 150         u8 data[4] = {
 151                 PN_PIPE_SB_NEGOTIATED_FC, pep_sb_size(2),
 152                 pn->tx_fc, pn->rx_fc,
 153         };
 154
 155         return pep_indicate(sk, PNS_PIPE_CREATED_IND, 1 /* sub-blocks */,
 156                                 data, 4, GFP_ATOMIC);
 157 }
 158
 159 static int pep_accept_conn(struct sock *sk, struct sk_buff *skb)
 160 {
 161         static const u8 data[20] = {
 162                 PAD, PAD, PAD, 2 /* sub-blocks */,
 163                 PN_PIPE_SB_REQUIRED_FC_TX, pep_sb_size(5), 3, PAD,
 164                         PN_MULTI_CREDIT_FLOW_CONTROL,
 165                         PN_ONE_CREDIT_FLOW_CONTROL,
 166                         PN_LEGACY_FLOW_CONTROL,
 167                         PAD,
 168                 PN_PIPE_SB_PREFERRED_FC_RX, pep_sb_size(5), 3, PAD,
 169                         PN_MULTI_CREDIT_FLOW_CONTROL,
 170                         PN_ONE_CREDIT_FLOW_CONTROL,
 171                         PN_LEGACY_FLOW_CONTROL,
 172                         PAD,
 173         };
 174
 175         might_sleep();
 176         return pep_reply(sk, skb, PN_PIPE_NO_ERROR, data, sizeof(data),
 177                                 GFP_KERNEL);
 178 }
 179
 180 static int pep_reject_conn(struct sock *sk, struct sk_buff *skb, u8 code,
 181                                 gfp_t priority)
 182 {
 183         static const u8 data[4] = { PAD, PAD, PAD, 0 /* sub-blocks */ };
 184         WARN_ON(code == PN_PIPE_NO_ERROR);
 185         return pep_reply(sk, skb, code, data, sizeof(data), priority);
 186 }
 187
 188 /* Control requests are not sent by the pipe service and have a specific
 189  * message format. */
 190 static int pep_ctrlreq_error(struct sock *sk, struct sk_buff *oskb, u8 code,
 191                                 gfp_t priority)
 192 {
 193         const struct pnpipehdr *oph = pnp_hdr(oskb);
 194         struct sk_buff *skb;
 195         struct pnpipehdr *ph;
 196         struct sockaddr_pn dst;
 197         u8 data[4] = {
 198                 oph->pep_type, /* PEP type */
 199                 code, /* error code, at an unusual offset */
 200                 PAD, PAD,
 201         };
 202
 203         skb = pep_alloc_skb(sk, data, 4, priority);
 204         if (!skb)
 205                 return -ENOMEM;
 206
 207         ph = pnp_hdr(skb);
 208         ph->utid = oph->utid;
 209         ph->message_id = PNS_PEP_CTRL_RESP;
 210         ph->pipe_handle = oph->pipe_handle;
 211         ph->data0 = oph->data[0]; /* CTRL id */
 212
 213         pn_skb_get_src_sockaddr(oskb, &dst);
 214         return pn_skb_send(sk, skb, &dst);
 215 }
 216
 217 static int pipe_snd_status(struct sock *sk, u8 type, u8 status, gfp_t priority)
 218 {
 219         u8 data[4] = { type, PAD, PAD, status };
 220
 221         return pep_indicate(sk, PNS_PEP_STATUS_IND, PN_PEP_TYPE_COMMON,
 222                                 data, 4, priority);
 223 }
 224
 225 /* Send our RX flow control information to the sender.
 226  * Socket must be locked. */
 227 static void pipe_grant_credits(struct sock *sk, gfp_t priority)
 228 {
 229         struct pep_sock *pn = pep_sk(sk);
 230
 231         BUG_ON(sk->sk_state != TCP_ESTABLISHED);
 232
 233         switch (pn->rx_fc) {
 234         case PN_LEGACY_FLOW_CONTROL: /* TODO */
 235                 break;
 236         case PN_ONE_CREDIT_FLOW_CONTROL:
 237                 if (pipe_snd_status(sk, PN_PEP_IND_FLOW_CONTROL,
 238                                         PEP_IND_READY, priority) == 0)
 239                         pn->rx_credits = 1;
 240                 break;
 241         case PN_MULTI_CREDIT_FLOW_CONTROL:
 242                 if ((pn->rx_credits + CREDITS_THR) > CREDITS_MAX)
 243                         break;
 244                 if (pipe_snd_status(sk, PN_PEP_IND_ID_MCFC_GRANT_CREDITS,
 245                                         CREDITS_MAX - pn->rx_credits,
 246                                         priority) == 0)
 247                         pn->rx_credits = CREDITS_MAX;
 248                 break;
 249         }
 250 }
 251
 252 static int pipe_rcv_status(struct sock *sk, struct sk_buff *skb)
 253 {
 254         struct pep_sock *pn = pep_sk(sk);
 255         struct pnpipehdr *hdr;
 256         int wake = 0;
 257
 258         if (!pskb_may_pull(skb, sizeof(*hdr) + 4))
 259                 return -EINVAL;
 260
 261         hdr = pnp_hdr(skb);
 262         if (hdr->pep_type != PN_PEP_TYPE_COMMON) {
 263                 net_dbg_ratelimited("Phonet unknown PEP type: %u\n",
 264                                     (unsigned int)hdr->pep_type);
 265                 return -EOPNOTSUPP;
 266         }
 267
 268         switch (hdr->data[0]) {
 269         case PN_PEP_IND_FLOW_CONTROL:
 270                 switch (pn->tx_fc) {
 271                 case PN_LEGACY_FLOW_CONTROL:
 272                         switch (hdr->data[3]) {
 273                         case PEP_IND_BUSY:
 274                                 atomic_set(&pn->tx_credits, 0);
 275                                 break;
 276                         case PEP_IND_READY:
 277                                 atomic_set(&pn->tx_credits, wake = 1);
 278                                 break;
 279                         }
 280                         break;
 281                 case PN_ONE_CREDIT_FLOW_CONTROL:
 282                         if (hdr->data[3] == PEP_IND_READY)
 283                                 atomic_set(&pn->tx_credits, wake = 1);
 284                         break;
 285                 }
 286                 break;
 287
 288         case PN_PEP_IND_ID_MCFC_GRANT_CREDITS:
 289                 if (pn->tx_fc != PN_MULTI_CREDIT_FLOW_CONTROL)
 290                         break;
 291                 atomic_add(wake = hdr->data[3], &pn->tx_credits);
 292                 break;
 293
 294         default:
 295                 net_dbg_ratelimited("Phonet unknown PEP indication: %u\n",
 296                                     (unsigned int)hdr->data[0]);
 297                 return -EOPNOTSUPP;
 298         }
 299         if (wake)
 300                 sk->sk_write_space(sk);
 301         return 0;
 302 }
 303
 304 static int pipe_rcv_created(struct sock *sk, struct sk_buff *skb)
 305 {
 306         struct pep_sock *pn = pep_sk(sk);
 307         struct pnpipehdr *hdr = pnp_hdr(skb);
 308         u8 n_sb = hdr->data0;
 309
 310         pn->rx_fc = pn->tx_fc = PN_LEGACY_FLOW_CONTROL;
 311         __skb_pull(skb, sizeof(*hdr));
 312         while (n_sb > 0) {
 313                 u8 type, buf[2], len = sizeof(buf);
 314                 u8 *data = pep_get_sb(skb, &type, &len, buf);
 315
 316                 if (data == NULL)
 317                         return -EINVAL;
 318                 switch (type) {
 319                 case PN_PIPE_SB_NEGOTIATED_FC:
 320                         if (len < 2 || (data[0] | data[1]) > 3)
 321                                 break;
 322                         pn->tx_fc = data[0] & 3;
 323                         pn->rx_fc = data[1] & 3;
 324                         break;
 325                 }
 326                 n_sb--;
 327         }
 328         return 0;
 329 }
 330
 331 /* Queue an skb to a connected sock.
 332  * Socket lock must be held. */
 333 static int pipe_do_rcv(struct sock *sk, struct sk_buff *skb)
 334 {
 335         struct pep_sock *pn = pep_sk(sk);
 336         struct pnpipehdr *hdr = pnp_hdr(skb);
 337         struct sk_buff_head *queue;
 338         int err = 0;
 339
 340         BUG_ON(sk->sk_state == TCP_CLOSE_WAIT);
 341
 342         switch (hdr->message_id) {
 343         case PNS_PEP_CONNECT_REQ:
 344                 pep_reject_conn(sk, skb, PN_PIPE_ERR_PEP_IN_USE, GFP_ATOMIC);
 345                 break;
 346
 347         case PNS_PEP_DISCONNECT_REQ:
 348                 pep_reply(sk, skb, PN_PIPE_NO_ERROR, NULL, 0, GFP_ATOMIC);
 349                 sk->sk_state = TCP_CLOSE_WAIT;
 350                 if (!sock_flag(sk, SOCK_DEAD))
 351                         sk->sk_state_change(sk);
 352                 break;
 353
 354         case PNS_PEP_ENABLE_REQ:
 355                 /* Wait for PNS_PIPE_(ENABLED|REDIRECTED)_IND */
 356                 pep_reply(sk, skb, PN_PIPE_NO_ERROR, NULL, 0, GFP_ATOMIC);
 357                 break;
 358
 359         case PNS_PEP_RESET_REQ:
 360                 switch (hdr->state_after_reset) {
 361                 case PN_PIPE_DISABLE:
 362                         pn->init_enable = 0;
 363                         break;
 364                 case PN_PIPE_ENABLE:
 365                         pn->init_enable = 1;
 366                         break;
 367                 default: /* not allowed to send an error here!? */
 368                         err = -EINVAL;
 369                         goto out;
 370                 }
 371                 fallthrough;
 372         case PNS_PEP_DISABLE_REQ:
 373                 atomic_set(&pn->tx_credits, 0);
 374                 pep_reply(sk, skb, PN_PIPE_NO_ERROR, NULL, 0, GFP_ATOMIC);
 375                 break;
 376
 377         case PNS_PEP_CTRL_REQ:
 378                 if (skb_queue_len(&pn->ctrlreq_queue) >= PNPIPE_CTRLREQ_MAX) {
 379                         atomic_inc(&sk->sk_drops);
 380                         break;
 381                 }
 382                 __skb_pull(skb, 4);
 383                 queue = &pn->ctrlreq_queue;
 384                 goto queue;
 385
 386         case PNS_PIPE_ALIGNED_DATA:
 387                 __skb_pull(skb, 1);
 388                 fallthrough;
 389         case PNS_PIPE_DATA:
 390                 __skb_pull(skb, 3); /* Pipe data header */
 391                 if (!pn_flow_safe(pn->rx_fc)) {
 392                         err = sock_queue_rcv_skb(sk, skb);
 393                         if (!err)
 394                                 return NET_RX_SUCCESS;
 395                         err = -ENOBUFS;
 396                         break;
 397                 }
 398
 399                 if (pn->rx_credits == 0) {
 400                         atomic_inc(&sk->sk_drops);
 401                         err = -ENOBUFS;
 402                         break;
 403                 }
 404                 pn->rx_credits--;
 405                 queue = &sk->sk_receive_queue;
 406                 goto queue;
 407
 408         case PNS_PEP_STATUS_IND:
 409                 pipe_rcv_status(sk, skb);
 410                 break;
 411
 412         case PNS_PIPE_REDIRECTED_IND:
 413                 err = pipe_rcv_created(sk, skb);
 414                 break;
 415
 416         case PNS_PIPE_CREATED_IND:
 417                 err = pipe_rcv_created(sk, skb);
 418                 if (err)
 419                         break;
 420                 fallthrough;
 421         case PNS_PIPE_RESET_IND:
 422                 if (!pn->init_enable)
 423                         break;
 424                 fallthrough;
 425         case PNS_PIPE_ENABLED_IND:
 426                 if (!pn_flow_safe(pn->tx_fc)) {
 427                         atomic_set(&pn->tx_credits, 1);
 428                         sk->sk_write_space(sk);
 429                 }
 430                 if (sk->sk_state == TCP_ESTABLISHED)
 431                         break; /* Nothing to do */
 432                 sk->sk_state = TCP_ESTABLISHED;
 433                 pipe_grant_credits(sk, GFP_ATOMIC);
 434                 break;
 435
 436         case PNS_PIPE_DISABLED_IND:
 437                 sk->sk_state = TCP_SYN_RECV;
 438                 pn->rx_credits = 0;
 439                 break;
 440
 441         default:
 442                 net_dbg_ratelimited("Phonet unknown PEP message: %u\n",
 443                                     hdr->message_id);
 444                 err = -EINVAL;
 445         }
 446 out:
 447         kfree_skb(skb);
 448         return (err == -ENOBUFS) ? NET_RX_DROP : NET_RX_SUCCESS;
 449
 450 queue:
 451         skb->dev = NULL;
 452         skb_set_owner_r(skb, sk);
 453         skb_queue_tail(queue, skb);
 454         if (!sock_flag(sk, SOCK_DEAD))
 455                 sk->sk_data_ready(sk);
 456         return NET_RX_SUCCESS;
 457 }
 458
 459 /* Destroy connected sock. */
 460 static void pipe_destruct(struct sock *sk)
 461 {
 462         struct pep_sock *pn = pep_sk(sk);
 463
 464         skb_queue_purge(&sk->sk_receive_queue);
 465         skb_queue_purge(&pn->ctrlreq_queue);
 466 }
 467
 468 static u8 pipe_negotiate_fc(const u8 *fcs, unsigned int n)
 469 {
 470         unsigned int i;
 471         u8 final_fc = PN_NO_FLOW_CONTROL;
 472
 473         for (i = 0; i < n; i++) {
 474                 u8 fc = fcs[i];
 475
 476                 if (fc > final_fc && fc < PN_MAX_FLOW_CONTROL)
 477                         final_fc = fc;
 478         }
 479         return final_fc;
 480 }
 481
 482 static int pep_connresp_rcv(struct sock *sk, struct sk_buff *skb)
 483 {
 484         struct pep_sock *pn = pep_sk(sk);
 485         struct pnpipehdr *hdr;
 486         u8 n_sb;
 487
 488         if (!pskb_pull(skb, sizeof(*hdr) + 4))
 489                 return -EINVAL;
 490
 491         hdr = pnp_hdr(skb);
 492         if (hdr->error_code != PN_PIPE_NO_ERROR)
 493                 return -ECONNREFUSED;
 494
 495         /* Parse sub-blocks */
 496         n_sb = hdr->data[3];
 497         while (n_sb > 0) {
 498                 u8 type, buf[6], len = sizeof(buf);
 499                 const u8 *data = pep_get_sb(skb, &type, &len, buf);
 500
 501                 if (data == NULL)
 502                         return -EINVAL;
 503
 504                 switch (type) {
 505                 case PN_PIPE_SB_REQUIRED_FC_TX:
 506                         if (len < 2 || len < data[0])
 507                                 break;
 508                         pn->tx_fc = pipe_negotiate_fc(data + 2, len - 2);
 509                         break;
 510
 511                 case PN_PIPE_SB_PREFERRED_FC_RX:
 512                         if (len < 2 || len < data[0])
 513                                 break;
 514                         pn->rx_fc = pipe_negotiate_fc(data + 2, len - 2);
 515                         break;
 516
 517                 }
 518                 n_sb--;
 519         }
 520
 521         return pipe_handler_send_created_ind(sk);
 522 }
 523
 524 static int pep_enableresp_rcv(struct sock *sk, struct sk_buff *skb)
 525 {
 526         struct pnpipehdr *hdr = pnp_hdr(skb);
 527
 528         if (hdr->error_code != PN_PIPE_NO_ERROR)
 529                 return -ECONNREFUSED;
 530
 531         return pep_indicate(sk, PNS_PIPE_ENABLED_IND, 0 /* sub-blocks */,
 532                 NULL, 0, GFP_ATOMIC);
 533
 534 }
 535
 536 static void pipe_start_flow_control(struct sock *sk)
 537 {
 538         struct pep_sock *pn = pep_sk(sk);
 539
 540         if (!pn_flow_safe(pn->tx_fc)) {
 541                 atomic_set(&pn->tx_credits, 1);
 542                 sk->sk_write_space(sk);
 543         }
 544         pipe_grant_credits(sk, GFP_ATOMIC);
 545 }
 546
 547 /* Queue an skb to an actively connected sock.
 548  * Socket lock must be held. */
 549 static int pipe_handler_do_rcv(struct sock *sk, struct sk_buff *skb)
 550 {
 551         struct pep_sock *pn = pep_sk(sk);
 552         struct pnpipehdr *hdr = pnp_hdr(skb);
 553         int err = NET_RX_SUCCESS;
 554
 555         switch (hdr->message_id) {
 556         case PNS_PIPE_ALIGNED_DATA:
 557                 __skb_pull(skb, 1);
 558                 fallthrough;
 559         case PNS_PIPE_DATA:
 560                 __skb_pull(skb, 3); /* Pipe data header */
 561                 if (!pn_flow_safe(pn->rx_fc)) {
 562                         err = sock_queue_rcv_skb(sk, skb);
 563                         if (!err)
 564                                 return NET_RX_SUCCESS;
 565                         err = NET_RX_DROP;
 566                         break;
 567                 }
 568
 569                 if (pn->rx_credits == 0) {
 570                         atomic_inc(&sk->sk_drops);
 571                         err = NET_RX_DROP;
 572                         break;
 573                 }
 574                 pn->rx_credits--;
 575                 skb->dev = NULL;
 576                 skb_set_owner_r(skb, sk);
 577                 skb_queue_tail(&sk->sk_receive_queue, skb);
 578                 if (!sock_flag(sk, SOCK_DEAD))
 579                         sk->sk_data_ready(sk);
 580                 return NET_RX_SUCCESS;
 581
 582         case PNS_PEP_CONNECT_RESP:
 583                 if (sk->sk_state != TCP_SYN_SENT)
 584                         break;
 585                 if (!sock_flag(sk, SOCK_DEAD))
 586                         sk->sk_state_change(sk);
 587                 if (pep_connresp_rcv(sk, skb)) {
 588                         sk->sk_state = TCP_CLOSE_WAIT;
 589                         break;
 590                 }
 591                 if (pn->init_enable == PN_PIPE_DISABLE)
 592                         sk->sk_state = TCP_SYN_RECV;
 593                 else {
 594                         sk->sk_state = TCP_ESTABLISHED;
 595                         pipe_start_flow_control(sk);
 596                 }
 597                 break;
 598
 599         case PNS_PEP_ENABLE_RESP:
 600                 if (sk->sk_state != TCP_SYN_SENT)
 601                         break;
 602
 603                 if (pep_enableresp_rcv(sk, skb)) {
 604                         sk->sk_state = TCP_CLOSE_WAIT;
 605                         break;
 606                 }
 607
 608                 sk->sk_state = TCP_ESTABLISHED;
 609                 pipe_start_flow_control(sk);
 610                 break;
 611
 612         case PNS_PEP_DISCONNECT_RESP:
 613                 /* sock should already be dead, nothing to do */
 614                 break;
 615
 616         case PNS_PEP_STATUS_IND:
 617                 pipe_rcv_status(sk, skb);
 618                 break;
 619         }
 620         kfree_skb(skb);
 621         return err;
 622 }
 623
 624 /* Listening sock must be locked */
 625 static struct sock *pep_find_pipe(const struct hlist_head *hlist,
 626                                         const struct sockaddr_pn *dst,
 627                                         u8 pipe_handle)
 628 {
 629         struct sock *sknode;
 630         u16 dobj = pn_sockaddr_get_object(dst);
 631
 632         sk_for_each(sknode, hlist) {
 633                 struct pep_sock *pnnode = pep_sk(sknode);
 634
 635                 /* Ports match, but addresses might not: */
 636                 if (pnnode->pn_sk.sobject != dobj)
 637                         continue;
 638                 if (pnnode->pipe_handle != pipe_handle)
 639                         continue;
 640                 if (sknode->sk_state == TCP_CLOSE_WAIT)
 641                         continue;
 642
 643                 sock_hold(sknode);
 644                 return sknode;
 645         }
 646         return NULL;
 647 }
 648
 649 /*
 650  * Deliver an skb to a listening sock.
 651  * Socket lock must be held.
 652  * We then queue the skb to the right connected sock (if any).
 653  */
 654 static int pep_do_rcv(struct sock *sk, struct sk_buff *skb)
 655 {
 656         struct pep_sock *pn = pep_sk(sk);
 657         struct sock *sknode;
 658         struct pnpipehdr *hdr;
 659         struct sockaddr_pn dst;
 660         u8 pipe_handle;
 661
 662         if (!pskb_may_pull(skb, sizeof(*hdr)))
 663                 goto drop;
 664
 665         hdr = pnp_hdr(skb);
 666         pipe_handle = hdr->pipe_handle;
 667         if (pipe_handle == PN_PIPE_INVALID_HANDLE)
 668                 goto drop;
 669
 670         pn_skb_get_dst_sockaddr(skb, &dst);
 671
 672         /* Look for an existing pipe handle */
 673         sknode = pep_find_pipe(&pn->hlist, &dst, pipe_handle);
 674         if (sknode)
 675                 return sk_receive_skb(sknode, skb, 1);
 676
 677         switch (hdr->message_id) {
 678         case PNS_PEP_CONNECT_REQ:
 679                 if (sk->sk_state != TCP_LISTEN || sk_acceptq_is_full(sk)) {
 680                         pep_reject_conn(sk, skb, PN_PIPE_ERR_PEP_IN_USE,
 681                                         GFP_ATOMIC);
 682                         break;
 683                 }
 684                 skb_queue_head(&sk->sk_receive_queue, skb);
 685                 sk_acceptq_added(sk);
 686                 if (!sock_flag(sk, SOCK_DEAD))
 687                         sk->sk_data_ready(sk);
 688                 return NET_RX_SUCCESS;
 689
 690         case PNS_PEP_DISCONNECT_REQ:
 691                 pep_reply(sk, skb, PN_PIPE_NO_ERROR, NULL, 0, GFP_ATOMIC);
 692                 break;
 693
 694         case PNS_PEP_CTRL_REQ:
 695                 pep_ctrlreq_error(sk, skb, PN_PIPE_INVALID_HANDLE, GFP_ATOMIC);
 696                 break;
 697
 698         case PNS_PEP_RESET_REQ:
 699         case PNS_PEP_ENABLE_REQ:
 700         case PNS_PEP_DISABLE_REQ:
 701                 /* invalid handle is not even allowed here! */
 702                 break;
 703
 704         default:
 705                 if ((1 << sk->sk_state)
 706                                 & ~(TCPF_CLOSE|TCPF_LISTEN|TCPF_CLOSE_WAIT))
 707                         /* actively connected socket */
 708                         return pipe_handler_do_rcv(sk, skb);
 709         }
 710 drop:
 711         kfree_skb(skb);
 712         return NET_RX_SUCCESS;
 713 }
 714
 715 static int pipe_do_remove(struct sock *sk)
 716 {
 717         struct pep_sock *pn = pep_sk(sk);
 718         struct pnpipehdr *ph;
 719         struct sk_buff *skb;
 720
 721         skb = pep_alloc_skb(sk, NULL, 0, GFP_KERNEL);
 722         if (!skb)
 723                 return -ENOMEM;
 724
 725         ph = pnp_hdr(skb);
 726         ph->utid = 0;
 727         ph->message_id = PNS_PIPE_REMOVE_REQ;
 728         ph->pipe_handle = pn->pipe_handle;
 729         ph->data0 = PAD;
 730         return pn_skb_send(sk, skb, NULL);
 731 }
 732
 733 /* associated socket ceases to exist */
 734 static void pep_sock_close(struct sock *sk, long timeout)
 735 {
 736         struct pep_sock *pn = pep_sk(sk);
 737         int ifindex = 0;
 738
 739         sock_hold(sk); /* keep a reference after sk_common_release() */
 740         sk_common_release(sk);
 741
 742         lock_sock(sk);
 743         if ((1 << sk->sk_state) & (TCPF_SYN_RECV|TCPF_ESTABLISHED)) {
 744                 if (sk->sk_backlog_rcv == pipe_do_rcv)
 745                         /* Forcefully remove dangling Phonet pipe */
 746                         pipe_do_remove(sk);
 747                 else
 748                         pipe_handler_request(sk, PNS_PEP_DISCONNECT_REQ, PAD,
 749                                                 NULL, 0);
 750         }
 751         sk->sk_state = TCP_CLOSE;
 752
 753         ifindex = pn->ifindex;
 754         pn->ifindex = 0;
 755         release_sock(sk);
 756
 757         if (ifindex)
 758                 gprs_detach(sk);
 759         sock_put(sk);
 760 }
 761
 762 static struct sock *pep_sock_accept(struct sock *sk, int flags, int *errp,
 763                                     bool kern)
 764 {
 765         struct pep_sock *pn = pep_sk(sk), *newpn;
 766         struct sock *newsk = NULL;
 767         struct sk_buff *skb;
 768         struct pnpipehdr *hdr;
 769         struct sockaddr_pn dst, src;
 770         int err;
 771         u16 peer_type;
 772         u8 pipe_handle, enabled, n_sb;
 773         u8 aligned = 0;
 774
 775         skb = skb_recv_datagram(sk, (flags & O_NONBLOCK) ? MSG_DONTWAIT : 0,
 776                                 errp);
 777         if (!skb)
 778                 return NULL;
 779
 780         lock_sock(sk);
 781         if (sk->sk_state != TCP_LISTEN) {
 782                 err = -EINVAL;
 783                 goto drop;
 784         }
 785         sk_acceptq_removed(sk);
 786
 787         err = -EPROTO;
 788         if (!pskb_may_pull(skb, sizeof(*hdr) + 4))
 789                 goto drop;
 790
 791         hdr = pnp_hdr(skb);
 792         pipe_handle = hdr->pipe_handle;
 793         switch (hdr->state_after_connect) {
 794         case PN_PIPE_DISABLE:
 795                 enabled = 0;
 796                 break;
 797         case PN_PIPE_ENABLE:
 798                 enabled = 1;
 799                 break;
 800         default:
 801                 pep_reject_conn(sk, skb, PN_PIPE_ERR_INVALID_PARAM,
 802                                 GFP_KERNEL);
 803                 goto drop;
 804         }
 805         peer_type = hdr->other_pep_type << 8;
 806
 807         /* Parse sub-blocks (options) */
 808         n_sb = hdr->data[3];
 809         while (n_sb > 0) {
 810                 u8 type, buf[1], len = sizeof(buf);
 811                 const u8 *data = pep_get_sb(skb, &type, &len, buf);
 812
 813                 if (data == NULL)
 814                         goto drop;
 815                 switch (type) {
 816                 case PN_PIPE_SB_CONNECT_REQ_PEP_SUB_TYPE:
 817                         if (len < 1)
 818                                 goto drop;
 819                         peer_type = (peer_type & 0xff00) | data[0];
 820                         break;
 821                 case PN_PIPE_SB_ALIGNED_DATA:
 822                         aligned = data[0] != 0;
 823                         break;
 824                 }
 825                 n_sb--;
 826         }
 827
 828         /* Check for duplicate pipe handle */
 829         newsk = pep_find_pipe(&pn->hlist, &dst, pipe_handle);
 830         if (unlikely(newsk)) {
 831                 __sock_put(newsk);
 832                 newsk = NULL;
 833                 pep_reject_conn(sk, skb, PN_PIPE_ERR_PEP_IN_USE, GFP_KERNEL);
 834                 goto drop;
 835         }
 836
 837         /* Create a new to-be-accepted sock */
 838         newsk = sk_alloc(sock_net(sk), PF_PHONET, GFP_KERNEL, sk->sk_prot,
 839                          kern);
 840         if (!newsk) {
 841                 pep_reject_conn(sk, skb, PN_PIPE_ERR_OVERLOAD, GFP_KERNEL);
 842                 err = -ENOBUFS;
 843                 goto drop;
 844         }
 845
 846         sock_init_data(NULL, newsk);
 847         newsk->sk_state = TCP_SYN_RECV;
 848         newsk->sk_backlog_rcv = pipe_do_rcv;
 849         newsk->sk_protocol = sk->sk_protocol;
 850         newsk->sk_destruct = pipe_destruct;
 851
 852         newpn = pep_sk(newsk);
 853         pn_skb_get_dst_sockaddr(skb, &dst);
 854         pn_skb_get_src_sockaddr(skb, &src);
 855         newpn->pn_sk.sobject = pn_sockaddr_get_object(&dst);
 856         newpn->pn_sk.dobject = pn_sockaddr_get_object(&src);
 857         newpn->pn_sk.resource = pn_sockaddr_get_resource(&dst);
 858         sock_hold(sk);
 859         newpn->listener = sk;
 860         skb_queue_head_init(&newpn->ctrlreq_queue);
 861         newpn->pipe_handle = pipe_handle;
 862         atomic_set(&newpn->tx_credits, 0);
 863         newpn->ifindex = 0;
 864         newpn->peer_type = peer_type;
 865         newpn->rx_credits = 0;
 866         newpn->rx_fc = newpn->tx_fc = PN_LEGACY_FLOW_CONTROL;
 867         newpn->init_enable = enabled;
 868         newpn->aligned = aligned;
 869
 870         err = pep_accept_conn(newsk, skb);
 871         if (err) {
 872                 __sock_put(sk);
 873                 sock_put(newsk);
 874                 newsk = NULL;
 875                 goto drop;
 876         }
 877         sk_add_node(newsk, &pn->hlist);
 878 drop:
 879         release_sock(sk);
 880         kfree_skb(skb);
 881         *errp = err;
 882         return newsk;
 883 }
 884
 885 static int pep_sock_connect(struct sock *sk, struct sockaddr *addr, int len)
 886 {
 887         struct pep_sock *pn = pep_sk(sk);
 888         int err;
 889         u8 data[4] = { 0 /* sub-blocks */, PAD, PAD, PAD };
 890
 891         if (pn->pipe_handle == PN_PIPE_INVALID_HANDLE)
 892                 pn->pipe_handle = 1; /* anything but INVALID_HANDLE */
 893
 894         err = pipe_handler_request(sk, PNS_PEP_CONNECT_REQ,
 895                                 pn->init_enable, data, 4);
 896         if (err) {
 897                 pn->pipe_handle = PN_PIPE_INVALID_HANDLE;
 898                 return err;
 899         }
 900
 901         sk->sk_state = TCP_SYN_SENT;
 902
 903         return 0;
 904 }
 905
 906 static int pep_sock_enable(struct sock *sk, struct sockaddr *addr, int len)
 907 {
 908         int err;
 909
 910         err = pipe_handler_request(sk, PNS_PEP_ENABLE_REQ, PAD,
 911                                 NULL, 0);
 912         if (err)
 913                 return err;
 914
 915         sk->sk_state = TCP_SYN_SENT;
 916
 917         return 0;
 918 }
 919
 920 static unsigned int pep_first_packet_length(struct sock *sk)
 921 {
 922         struct pep_sock *pn = pep_sk(sk);
 923         struct sk_buff_head *q;
 924         struct sk_buff *skb;
 925         unsigned int len = 0;
 926         bool found = false;
 927
 928         if (sock_flag(sk, SOCK_URGINLINE)) {
 929                 q = &pn->ctrlreq_queue;
 930                 spin_lock_bh(&q->lock);
 931                 skb = skb_peek(q);
 932                 if (skb) {
 933                         len = skb->len;
 934                         found = true;
 935                 }
 936                 spin_unlock_bh(&q->lock);
 937         }
 938
 939         if (likely(!found)) {
 940                 q = &sk->sk_receive_queue;
 941                 spin_lock_bh(&q->lock);
 942                 skb = skb_peek(q);
 943                 if (skb)
 944                         len = skb->len;
 945                 spin_unlock_bh(&q->lock);
 946         }
 947
 948         return len;
 949 }
 950
 951 static int pep_ioctl(struct sock *sk, int cmd, int *karg)
 952 {
 953         struct pep_sock *pn = pep_sk(sk);
 954         int ret = -ENOIOCTLCMD;
 955
 956         switch (cmd) {
 957         case SIOCINQ:
 958                 if (sk->sk_state == TCP_LISTEN) {
 959                         ret = -EINVAL;
 960                         break;
 961                 }
 962
 963                 *karg = pep_first_packet_length(sk);
 964                 ret = 0;
 965                 break;
 966
 967         case SIOCPNENABLEPIPE:
 968                 lock_sock(sk);
 969                 if (sk->sk_state == TCP_SYN_SENT)
 970                         ret =  -EBUSY;
 971                 else if (sk->sk_state == TCP_ESTABLISHED)
 972                         ret = -EISCONN;
 973                 else if (!pn->pn_sk.sobject)
 974                         ret = -EADDRNOTAVAIL;
 975                 else
 976                         ret = pep_sock_enable(sk, NULL, 0);
 977                 release_sock(sk);
 978                 break;
 979         }
 980
 981         return ret;
 982 }
 983
 984 static int pep_init(struct sock *sk)
 985 {
 986         struct pep_sock *pn = pep_sk(sk);
 987
 988         sk->sk_destruct = pipe_destruct;
 989         INIT_HLIST_HEAD(&pn->hlist);
 990         pn->listener = NULL;
 991         skb_queue_head_init(&pn->ctrlreq_queue);
 992         atomic_set(&pn->tx_credits, 0);
 993         pn->ifindex = 0;
 994         pn->peer_type = 0;
 995         pn->pipe_handle = PN_PIPE_INVALID_HANDLE;
 996         pn->rx_credits = 0;
 997         pn->rx_fc = pn->tx_fc = PN_LEGACY_FLOW_CONTROL;
 998         pn->init_enable = 1;
 999         pn->aligned = 0;
1000         return 0;
1001 }
1002
1003 static int pep_setsockopt(struct sock *sk, int level, int optname,
1004                           sockptr_t optval, unsigned int optlen)
1005 {
1006         struct pep_sock *pn = pep_sk(sk);
1007         int val = 0, err = 0;
1008
1009         if (level != SOL_PNPIPE)
1010                 return -ENOPROTOOPT;
1011         if (optlen >= sizeof(int)) {
1012                 if (copy_from_sockptr(&val, optval, sizeof(int)))
1013                         return -EFAULT;
1014         }
1015
1016         lock_sock(sk);
1017         switch (optname) {
1018         case PNPIPE_ENCAP:
1019                 if (val && val != PNPIPE_ENCAP_IP) {
1020                         err = -EINVAL;
1021                         break;
1022                 }
1023                 if (!pn->ifindex == !val)
1024                         break; /* Nothing to do! */
1025                 if (!capable(CAP_NET_ADMIN)) {
1026                         err = -EPERM;
1027                         break;
1028                 }
1029                 if (val) {
1030                         release_sock(sk);
1031                         err = gprs_attach(sk);
1032                         if (err > 0) {
1033                                 pn->ifindex = err;
1034                                 err = 0;
1035                         }
1036                 } else {
1037                         pn->ifindex = 0;
1038                         release_sock(sk);
1039                         gprs_detach(sk);
1040                         err = 0;
1041                 }
1042                 goto out_norel;
1043
1044         case PNPIPE_HANDLE:
1045                 if ((sk->sk_state == TCP_CLOSE) &&
1046                         (val >= 0) && (val < PN_PIPE_INVALID_HANDLE))
1047                         pn->pipe_handle = val;
1048                 else
1049                         err = -EINVAL;
1050                 break;
1051
1052         case PNPIPE_INITSTATE:
1053                 pn->init_enable = !!val;
1054                 break;
1055
1056         default:
1057                 err = -ENOPROTOOPT;
1058         }
1059         release_sock(sk);
1060
1061 out_norel:
1062         return err;
1063 }
1064
1065 static int pep_getsockopt(struct sock *sk, int level, int optname,
1066                                 char __user *optval, int __user *optlen)
1067 {
1068         struct pep_sock *pn = pep_sk(sk);
1069         int len, val;
1070
1071         if (level != SOL_PNPIPE)
1072                 return -ENOPROTOOPT;
1073         if (get_user(len, optlen))
1074                 return -EFAULT;
1075
1076         switch (optname) {
1077         case PNPIPE_ENCAP:
1078                 val = pn->ifindex ? PNPIPE_ENCAP_IP : PNPIPE_ENCAP_NONE;
1079                 break;
1080
1081         case PNPIPE_IFINDEX:
1082                 val = pn->ifindex;
1083                 break;
1084
1085         case PNPIPE_HANDLE:
1086                 val = pn->pipe_handle;
1087                 if (val == PN_PIPE_INVALID_HANDLE)
1088                         return -EINVAL;
1089                 break;
1090
1091         case PNPIPE_INITSTATE:
1092                 val = pn->init_enable;
1093                 break;
1094
1095         default:
1096                 return -ENOPROTOOPT;
1097         }
1098
1099         len = min_t(unsigned int, sizeof(int), len);
1100         if (put_user(len, optlen))
1101                 return -EFAULT;
1102         if (put_user(val, (int __user *) optval))
1103                 return -EFAULT;
1104         return 0;
1105 }
1106
1107 static int pipe_skb_send(struct sock *sk, struct sk_buff *skb)
1108 {
1109         struct pep_sock *pn = pep_sk(sk);
1110         struct pnpipehdr *ph;
1111         int err;
1112
1113         if (pn_flow_safe(pn->tx_fc) &&
1114             !atomic_add_unless(&pn->tx_credits, -1, 0)) {
1115                 kfree_skb(skb);
1116                 return -ENOBUFS;
1117         }
1118
1119         skb_push(skb, 3 + pn->aligned);
1120         skb_reset_transport_header(skb);
1121         ph = pnp_hdr(skb);
1122         ph->utid = 0;
1123         if (pn->aligned) {
1124                 ph->message_id = PNS_PIPE_ALIGNED_DATA;
1125                 ph->data0 = 0; /* padding */
1126         } else
1127                 ph->message_id = PNS_PIPE_DATA;
1128         ph->pipe_handle = pn->pipe_handle;
1129         err = pn_skb_send(sk, skb, NULL);
1130
1131         if (err && pn_flow_safe(pn->tx_fc))
1132                 atomic_inc(&pn->tx_credits);
1133         return err;
1134
1135 }
1136
1137 static int pep_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
1138 {
1139         struct pep_sock *pn = pep_sk(sk);
1140         struct sk_buff *skb;
1141         long timeo;
1142         int flags = msg->msg_flags;
1143         int err, done;
1144
1145         if (len > USHRT_MAX)
1146                 return -EMSGSIZE;
1147
1148         if ((msg->msg_flags & ~(MSG_DONTWAIT|MSG_EOR|MSG_NOSIGNAL|
1149                                 MSG_CMSG_COMPAT)) ||
1150                         !(msg->msg_flags & MSG_EOR))
1151                 return -EOPNOTSUPP;
1152
1153         skb = sock_alloc_send_skb(sk, MAX_PNPIPE_HEADER + len,
1154                                         flags & MSG_DONTWAIT, &err);
1155         if (!skb)
1156                 return err;
1157
1158         skb_reserve(skb, MAX_PHONET_HEADER + 3 + pn->aligned);
1159         err = memcpy_from_msg(skb_put(skb, len), msg, len);
1160         if (err < 0)
1161                 goto outfree;
1162
1163         lock_sock(sk);
1164         timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT);
1165         if ((1 << sk->sk_state) & (TCPF_LISTEN|TCPF_CLOSE)) {
1166                 err = -ENOTCONN;
1167                 goto out;
1168         }
1169         if (sk->sk_state != TCP_ESTABLISHED) {
1170                 /* Wait until the pipe gets to enabled state */
1171 disabled:
1172                 err = sk_stream_wait_connect(sk, &timeo);
1173                 if (err)
1174                         goto out;
1175
1176                 if (sk->sk_state == TCP_CLOSE_WAIT) {
1177                         err = -ECONNRESET;
1178                         goto out;
1179                 }
1180         }
1181         BUG_ON(sk->sk_state != TCP_ESTABLISHED);
1182
1183         /* Wait until flow control allows TX */
1184         done = atomic_read(&pn->tx_credits);
1185         while (!done) {
1186                 DEFINE_WAIT_FUNC(wait, woken_wake_function);
1187
1188                 if (!timeo) {
1189                         err = -EAGAIN;
1190                         goto out;
1191                 }
1192                 if (signal_pending(current)) {
1193                         err = sock_intr_errno(timeo);
1194                         goto out;
1195                 }
1196
1197                 add_wait_queue(sk_sleep(sk), &wait);
1198                 done = sk_wait_event(sk, &timeo, atomic_read(&pn->tx_credits), &wait);
1199                 remove_wait_queue(sk_sleep(sk), &wait);
1200
1201                 if (sk->sk_state != TCP_ESTABLISHED)
1202                         goto disabled;
1203         }
1204
1205         err = pipe_skb_send(sk, skb);
1206         if (err >= 0)
1207                 err = len; /* success! */
1208         skb = NULL;
1209 out:
1210         release_sock(sk);
1211 outfree:
1212         kfree_skb(skb);
1213         return err;
1214 }
1215
1216 int pep_writeable(struct sock *sk)
1217 {
1218         struct pep_sock *pn = pep_sk(sk);
1219
1220         return atomic_read(&pn->tx_credits);
1221 }
1222
1223 int pep_write(struct sock *sk, struct sk_buff *skb)
1224 {
1225         struct sk_buff *rskb, *fs;
1226         int flen = 0;
1227
1228         if (pep_sk(sk)->aligned)
1229                 return pipe_skb_send(sk, skb);
1230
1231         rskb = alloc_skb(MAX_PNPIPE_HEADER, GFP_ATOMIC);
1232         if (!rskb) {
1233                 kfree_skb(skb);
1234                 return -ENOMEM;
1235         }
1236         skb_shinfo(rskb)->frag_list = skb;
1237         rskb->len += skb->len;
1238         rskb->data_len += rskb->len;
1239         rskb->truesize += rskb->len;
1240
1241         /* Avoid nested fragments */
1242         skb_walk_frags(skb, fs)
1243                 flen += fs->len;
1244         skb->next = skb_shinfo(skb)->frag_list;
1245         skb_frag_list_init(skb);
1246         skb->len -= flen;
1247         skb->data_len -= flen;
1248         skb->truesize -= flen;
1249
1250         skb_reserve(rskb, MAX_PHONET_HEADER + 3);
1251         return pipe_skb_send(sk, rskb);
1252 }
1253
1254 struct sk_buff *pep_read(struct sock *sk)
1255 {
1256         struct sk_buff *skb = skb_dequeue(&sk->sk_receive_queue);
1257
1258         if (sk->sk_state == TCP_ESTABLISHED)
1259                 pipe_grant_credits(sk, GFP_ATOMIC);
1260         return skb;
1261 }
1262
1263 static int pep_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
1264                        int flags, int *addr_len)
1265 {
1266         struct sk_buff *skb;
1267         int err;
1268
1269         if (flags & ~(MSG_OOB|MSG_PEEK|MSG_TRUNC|MSG_DONTWAIT|MSG_WAITALL|
1270                         MSG_NOSIGNAL|MSG_CMSG_COMPAT))
1271                 return -EOPNOTSUPP;
1272
1273         if (unlikely(1 << sk->sk_state & (TCPF_LISTEN | TCPF_CLOSE)))
1274                 return -ENOTCONN;
1275
1276         if ((flags & MSG_OOB) || sock_flag(sk, SOCK_URGINLINE)) {
1277                 /* Dequeue and acknowledge control request */
1278                 struct pep_sock *pn = pep_sk(sk);
1279
1280                 if (flags & MSG_PEEK)
1281                         return -EOPNOTSUPP;
1282                 skb = skb_dequeue(&pn->ctrlreq_queue);
1283                 if (skb) {
1284                         pep_ctrlreq_error(sk, skb, PN_PIPE_NO_ERROR,
1285                                                 GFP_KERNEL);
1286                         msg->msg_flags |= MSG_OOB;
1287                         goto copy;
1288                 }
1289                 if (flags & MSG_OOB)
1290                         return -EINVAL;
1291         }
1292
1293         skb = skb_recv_datagram(sk, flags, &err);
1294         lock_sock(sk);
1295         if (skb == NULL) {
1296                 if (err == -ENOTCONN && sk->sk_state == TCP_CLOSE_WAIT)
1297                         err = -ECONNRESET;
1298                 release_sock(sk);
1299                 return err;
1300         }
1301
1302         if (sk->sk_state == TCP_ESTABLISHED)
1303                 pipe_grant_credits(sk, GFP_KERNEL);
1304         release_sock(sk);
1305 copy:
1306         msg->msg_flags |= MSG_EOR;
1307         if (skb->len > len)
1308                 msg->msg_flags |= MSG_TRUNC;
1309         else
1310                 len = skb->len;
1311
1312         err = skb_copy_datagram_msg(skb, 0, msg, len);
1313         if (!err)
1314                 err = (flags & MSG_TRUNC) ? skb->len : len;
1315
1316         skb_free_datagram(sk, skb);
1317         return err;
1318 }
1319
1320 static void pep_sock_unhash(struct sock *sk)
1321 {
1322         struct pep_sock *pn = pep_sk(sk);
1323         struct sock *skparent = NULL;
1324
1325         lock_sock(sk);
1326
1327         if (pn->listener != NULL) {
1328                 skparent = pn->listener;
1329                 pn->listener = NULL;
1330                 release_sock(sk);
1331
1332                 pn = pep_sk(skparent);
1333                 lock_sock(skparent);
1334                 sk_del_node_init(sk);
1335                 sk = skparent;
1336         }
1337
1338         /* Unhash a listening sock only when it is closed
1339          * and all of its active connected pipes are closed. */
1340         if (hlist_empty(&pn->hlist))
1341                 pn_sock_unhash(&pn->pn_sk.sk);
1342         release_sock(sk);
1343
1344         if (skparent)
1345                 sock_put(skparent);
1346 }
1347
1348 static struct proto pep_proto = {
1349         .close          = pep_sock_close,
1350         .accept         = pep_sock_accept,
1351         .connect        = pep_sock_connect,
1352         .ioctl          = pep_ioctl,
1353         .init           = pep_init,
1354         .setsockopt     = pep_setsockopt,
1355         .getsockopt     = pep_getsockopt,
1356         .sendmsg        = pep_sendmsg,
1357         .recvmsg        = pep_recvmsg,
1358         .backlog_rcv    = pep_do_rcv,
1359         .hash           = pn_sock_hash,
1360         .unhash         = pep_sock_unhash,
1361         .get_port       = pn_sock_get_port,
1362         .obj_size       = sizeof(struct pep_sock),
1363         .owner          = THIS_MODULE,
1364         .name           = "PNPIPE",
1365 };
1366
1367 static const struct phonet_protocol pep_pn_proto = {
1368         .ops            = &phonet_stream_ops,
1369         .prot           = &pep_proto,
1370         .sock_type      = SOCK_SEQPACKET,
1371 };
1372
1373 static int __init pep_register(void)
1374 {
1375         return phonet_proto_register(PN_PROTO_PIPE, &pep_pn_proto);
1376 }
1377
1378 static void __exit pep_unregister(void)
1379 {
1380         phonet_proto_unregister(PN_PROTO_PIPE, &pep_pn_proto);
1381 }
1382
1383 module_init(pep_register);
1384 module_exit(pep_unregister);
1385 MODULE_AUTHOR("Remi Denis-Courmont, Nokia");
1386 MODULE_DESCRIPTION("Phonet pipe protocol");
1387 MODULE_LICENSE("GPL");
1388 MODULE_ALIAS_NET_PF_PROTO(PF_PHONET, PN_PROTO_PIPE);