net/phonet/pep.c

   1 /*
   2  * File: pep.c
   3  *
   4  * Phonet pipe protocol end point socket
   5  *
   6  * Copyright (C) 2008 Nokia Corporation.
   7  *
   8  * Author: Rémi Denis-Courmont
   9  *
  10  * This program is free software; you can redistribute it and/or
  11  * modify it under the terms of the GNU General Public License
  12  * version 2 as published by the Free Software Foundation.
  13  *
  14  * This program is distributed in the hope that it will be useful, but
  15  * WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  17  * General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program; if not, write to the Free Software
  21  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
  22  * 02110-1301 USA
  23  */
  24
  25 #include <linux/kernel.h>
  26 #include <linux/slab.h>
  27 #include <linux/socket.h>
  28 #include <net/sock.h>
  29 #include <net/tcp_states.h>
  30 #include <asm/ioctls.h>
  31
  32 #include <linux/phonet.h>
  33 #include <linux/module.h>
  34 #include <net/phonet/phonet.h>
  35 #include <net/phonet/pep.h>
  36 #include <net/phonet/gprs.h>
  37
  38 /* sk_state values:
  39  * TCP_CLOSE            sock not in use yet
  40  * TCP_CLOSE_WAIT       disconnected pipe
  41  * TCP_LISTEN           listening pipe endpoint
  42  * TCP_SYN_RECV         connected pipe in disabled state
  43  * TCP_ESTABLISHED      connected pipe in enabled state
  44  *
  45  * pep_sock locking:
  46  *  - sk_state, hlist: sock lock needed
  47  *  - listener: read only
  48  *  - pipe_handle: read only
  49  */
  50
  51 #define CREDITS_MAX     10
  52 #define CREDITS_THR     7
  53
  54 #define pep_sb_size(s) (((s) + 5) & ~3) /* 2-bytes head, 32-bits aligned */
  55
  56 /* Get the next TLV sub-block. */
  57 static unsigned char *pep_get_sb(struct sk_buff *skb, u8 *ptype, u8 *plen,
  58                                         void *buf)
  59 {
  60         void *data = NULL;
  61         struct {
  62                 u8 sb_type;
  63                 u8 sb_len;
  64         } *ph, h;
  65         int buflen = *plen;
  66
  67         ph = skb_header_pointer(skb, 0, 2, &h);
  68         if (ph == NULL || ph->sb_len < 2 || !pskb_may_pull(skb, ph->sb_len))
  69                 return NULL;
  70         ph->sb_len -= 2;
  71         *ptype = ph->sb_type;
  72         *plen = ph->sb_len;
  73
  74         if (buflen > ph->sb_len)
  75                 buflen = ph->sb_len;
  76         data = skb_header_pointer(skb, 2, buflen, buf);
  77         __skb_pull(skb, 2 + ph->sb_len);
  78         return data;
  79 }
  80
  81 static struct sk_buff *pep_alloc_skb(struct sock *sk, const void *payload,
  82                                         int len, gfp_t priority)
  83 {
  84         struct sk_buff *skb = alloc_skb(MAX_PNPIPE_HEADER + len, priority);
  85         if (!skb)
  86                 return NULL;
  87         skb_set_owner_w(skb, sk);
  88
  89         skb_reserve(skb, MAX_PNPIPE_HEADER);
  90         __skb_put(skb, len);
  91         skb_copy_to_linear_data(skb, payload, len);
  92         __skb_push(skb, sizeof(struct pnpipehdr));
  93         skb_reset_transport_header(skb);
  94         return skb;
  95 }
  96
  97 static int pep_reply(struct sock *sk, struct sk_buff *oskb, u8 code,
  98                         const void *data, int len, gfp_t priority)
  99 {
 100         const struct pnpipehdr *oph = pnp_hdr(oskb);
 101         struct pnpipehdr *ph;
 102         struct sk_buff *skb;
 103         struct sockaddr_pn peer;
 104
 105         skb = pep_alloc_skb(sk, data, len, priority);
 106         if (!skb)
 107                 return -ENOMEM;
 108
 109         ph = pnp_hdr(skb);
 110         ph->utid = oph->utid;
 111         ph->message_id = oph->message_id + 1; /* REQ -> RESP */
 112         ph->pipe_handle = oph->pipe_handle;
 113         ph->error_code = code;
 114
 115         pn_skb_get_src_sockaddr(oskb, &peer);
 116         return pn_skb_send(sk, skb, &peer);
 117 }
 118
 119 static int pep_indicate(struct sock *sk, u8 id, u8 code,
 120                         const void *data, int len, gfp_t priority)
 121 {
 122         struct pep_sock *pn = pep_sk(sk);
 123         struct pnpipehdr *ph;
 124         struct sk_buff *skb;
 125
 126         skb = pep_alloc_skb(sk, data, len, priority);
 127         if (!skb)
 128                 return -ENOMEM;
 129
 130         ph = pnp_hdr(skb);
 131         ph->utid = 0;
 132         ph->message_id = id;
 133         ph->pipe_handle = pn->pipe_handle;
 134         ph->error_code = code;
 135         return pn_skb_send(sk, skb, NULL);
 136 }
 137
 138 #define PAD 0x00
 139
 140 static int pipe_handler_request(struct sock *sk, u8 id, u8 code,
 141                                 const void *data, int len)
 142 {
 143         struct pep_sock *pn = pep_sk(sk);
 144         struct pnpipehdr *ph;
 145         struct sk_buff *skb;
 146
 147         skb = pep_alloc_skb(sk, data, len, GFP_KERNEL);
 148         if (!skb)
 149                 return -ENOMEM;
 150
 151         ph = pnp_hdr(skb);
 152         ph->utid = id; /* whatever */
 153         ph->message_id = id;
 154         ph->pipe_handle = pn->pipe_handle;
 155         ph->error_code = code;
 156         return pn_skb_send(sk, skb, NULL);
 157 }
 158
 159 static int pipe_handler_send_created_ind(struct sock *sk)
 160 {
 161         struct pep_sock *pn = pep_sk(sk);
 162         u8 data[4] = {
 163                 PN_PIPE_SB_NEGOTIATED_FC, pep_sb_size(2),
 164                 pn->tx_fc, pn->rx_fc,
 165         };
 166
 167         return pep_indicate(sk, PNS_PIPE_CREATED_IND, 1 /* sub-blocks */,
 168                                 data, 4, GFP_ATOMIC);
 169 }
 170
 171 static int pep_accept_conn(struct sock *sk, struct sk_buff *skb)
 172 {
 173         static const u8 data[20] = {
 174                 PAD, PAD, PAD, 2 /* sub-blocks */,
 175                 PN_PIPE_SB_REQUIRED_FC_TX, pep_sb_size(5), 3, PAD,
 176                         PN_MULTI_CREDIT_FLOW_CONTROL,
 177                         PN_ONE_CREDIT_FLOW_CONTROL,
 178                         PN_LEGACY_FLOW_CONTROL,
 179                         PAD,
 180                 PN_PIPE_SB_PREFERRED_FC_RX, pep_sb_size(5), 3, PAD,
 181                         PN_MULTI_CREDIT_FLOW_CONTROL,
 182                         PN_ONE_CREDIT_FLOW_CONTROL,
 183                         PN_LEGACY_FLOW_CONTROL,
 184                         PAD,
 185         };
 186
 187         might_sleep();
 188         return pep_reply(sk, skb, PN_PIPE_NO_ERROR, data, sizeof(data),
 189                                 GFP_KERNEL);
 190 }
 191
 192 static int pep_reject_conn(struct sock *sk, struct sk_buff *skb, u8 code,
 193                                 gfp_t priority)
 194 {
 195         static const u8 data[4] = { PAD, PAD, PAD, 0 /* sub-blocks */ };
 196         WARN_ON(code == PN_PIPE_NO_ERROR);
 197         return pep_reply(sk, skb, code, data, sizeof(data), priority);
 198 }
 199
 200 /* Control requests are not sent by the pipe service and have a specific
 201  * message format. */
 202 static int pep_ctrlreq_error(struct sock *sk, struct sk_buff *oskb, u8 code,
 203                                 gfp_t priority)
 204 {
 205         const struct pnpipehdr *oph = pnp_hdr(oskb);
 206         struct sk_buff *skb;
 207         struct pnpipehdr *ph;
 208         struct sockaddr_pn dst;
 209         u8 data[4] = {
 210                 oph->pep_type, /* PEP type */
 211                 code, /* error code, at an unusual offset */
 212                 PAD, PAD,
 213         };
 214
 215         skb = pep_alloc_skb(sk, data, 4, priority);
 216         if (!skb)
 217                 return -ENOMEM;
 218
 219         ph = pnp_hdr(skb);
 220         ph->utid = oph->utid;
 221         ph->message_id = PNS_PEP_CTRL_RESP;
 222         ph->pipe_handle = oph->pipe_handle;
 223         ph->data0 = oph->data[0]; /* CTRL id */
 224
 225         pn_skb_get_src_sockaddr(oskb, &dst);
 226         return pn_skb_send(sk, skb, &dst);
 227 }
 228
 229 static int pipe_snd_status(struct sock *sk, u8 type, u8 status, gfp_t priority)
 230 {
 231         u8 data[4] = { type, PAD, PAD, status };
 232
 233         return pep_indicate(sk, PNS_PEP_STATUS_IND, PN_PEP_TYPE_COMMON,
 234                                 data, 4, priority);
 235 }
 236
 237 /* Send our RX flow control information to the sender.
 238  * Socket must be locked. */
 239 static void pipe_grant_credits(struct sock *sk, gfp_t priority)
 240 {
 241         struct pep_sock *pn = pep_sk(sk);
 242
 243         BUG_ON(sk->sk_state != TCP_ESTABLISHED);
 244
 245         switch (pn->rx_fc) {
 246         case PN_LEGACY_FLOW_CONTROL: /* TODO */
 247                 break;
 248         case PN_ONE_CREDIT_FLOW_CONTROL:
 249                 if (pipe_snd_status(sk, PN_PEP_IND_FLOW_CONTROL,
 250                                         PEP_IND_READY, priority) == 0)
 251                         pn->rx_credits = 1;
 252                 break;
 253         case PN_MULTI_CREDIT_FLOW_CONTROL:
 254                 if ((pn->rx_credits + CREDITS_THR) > CREDITS_MAX)
 255                         break;
 256                 if (pipe_snd_status(sk, PN_PEP_IND_ID_MCFC_GRANT_CREDITS,
 257                                         CREDITS_MAX - pn->rx_credits,
 258                                         priority) == 0)
 259                         pn->rx_credits = CREDITS_MAX;
 260                 break;
 261         }
 262 }
 263
 264 static int pipe_rcv_status(struct sock *sk, struct sk_buff *skb)
 265 {
 266         struct pep_sock *pn = pep_sk(sk);
 267         struct pnpipehdr *hdr;
 268         int wake = 0;
 269
 270         if (!pskb_may_pull(skb, sizeof(*hdr) + 4))
 271                 return -EINVAL;
 272
 273         hdr = pnp_hdr(skb);
 274         if (hdr->pep_type != PN_PEP_TYPE_COMMON) {
 275                 net_dbg_ratelimited("Phonet unknown PEP type: %u\n",
 276                                     (unsigned int)hdr->pep_type);
 277                 return -EOPNOTSUPP;
 278         }
 279
 280         switch (hdr->data[0]) {
 281         case PN_PEP_IND_FLOW_CONTROL:
 282                 switch (pn->tx_fc) {
 283                 case PN_LEGACY_FLOW_CONTROL:
 284                         switch (hdr->data[3]) {
 285                         case PEP_IND_BUSY:
 286                                 atomic_set(&pn->tx_credits, 0);
 287                                 break;
 288                         case PEP_IND_READY:
 289                                 atomic_set(&pn->tx_credits, wake = 1);
 290                                 break;
 291                         }
 292                         break;
 293                 case PN_ONE_CREDIT_FLOW_CONTROL:
 294                         if (hdr->data[3] == PEP_IND_READY)
 295                                 atomic_set(&pn->tx_credits, wake = 1);
 296                         break;
 297                 }
 298                 break;
 299
 300         case PN_PEP_IND_ID_MCFC_GRANT_CREDITS:
 301                 if (pn->tx_fc != PN_MULTI_CREDIT_FLOW_CONTROL)
 302                         break;
 303                 atomic_add(wake = hdr->data[3], &pn->tx_credits);
 304                 break;
 305
 306         default:
 307                 net_dbg_ratelimited("Phonet unknown PEP indication: %u\n",
 308                                     (unsigned int)hdr->data[0]);
 309                 return -EOPNOTSUPP;
 310         }
 311         if (wake)
 312                 sk->sk_write_space(sk);
 313         return 0;
 314 }
 315
 316 static int pipe_rcv_created(struct sock *sk, struct sk_buff *skb)
 317 {
 318         struct pep_sock *pn = pep_sk(sk);
 319         struct pnpipehdr *hdr = pnp_hdr(skb);
 320         u8 n_sb = hdr->data0;
 321
 322         pn->rx_fc = pn->tx_fc = PN_LEGACY_FLOW_CONTROL;
 323         __skb_pull(skb, sizeof(*hdr));
 324         while (n_sb > 0) {
 325                 u8 type, buf[2], len = sizeof(buf);
 326                 u8 *data = pep_get_sb(skb, &type, &len, buf);
 327
 328                 if (data == NULL)
 329                         return -EINVAL;
 330                 switch (type) {
 331                 case PN_PIPE_SB_NEGOTIATED_FC:
 332                         if (len < 2 || (data[0] | data[1]) > 3)
 333                                 break;
 334                         pn->tx_fc = data[0] & 3;
 335                         pn->rx_fc = data[1] & 3;
 336                         break;
 337                 }
 338                 n_sb--;
 339         }
 340         return 0;
 341 }
 342
 343 /* Queue an skb to a connected sock.
 344  * Socket lock must be held. */
 345 static int pipe_do_rcv(struct sock *sk, struct sk_buff *skb)
 346 {
 347         struct pep_sock *pn = pep_sk(sk);
 348         struct pnpipehdr *hdr = pnp_hdr(skb);
 349         struct sk_buff_head *queue;
 350         int err = 0;
 351
 352         BUG_ON(sk->sk_state == TCP_CLOSE_WAIT);
 353
 354         switch (hdr->message_id) {
 355         case PNS_PEP_CONNECT_REQ:
 356                 pep_reject_conn(sk, skb, PN_PIPE_ERR_PEP_IN_USE, GFP_ATOMIC);
 357                 break;
 358
 359         case PNS_PEP_DISCONNECT_REQ:
 360                 pep_reply(sk, skb, PN_PIPE_NO_ERROR, NULL, 0, GFP_ATOMIC);
 361                 sk->sk_state = TCP_CLOSE_WAIT;
 362                 if (!sock_flag(sk, SOCK_DEAD))
 363                         sk->sk_state_change(sk);
 364                 break;
 365
 366         case PNS_PEP_ENABLE_REQ:
 367                 /* Wait for PNS_PIPE_(ENABLED|REDIRECTED)_IND */
 368                 pep_reply(sk, skb, PN_PIPE_NO_ERROR, NULL, 0, GFP_ATOMIC);
 369                 break;
 370
 371         case PNS_PEP_RESET_REQ:
 372                 switch (hdr->state_after_reset) {
 373                 case PN_PIPE_DISABLE:
 374                         pn->init_enable = 0;
 375                         break;
 376                 case PN_PIPE_ENABLE:
 377                         pn->init_enable = 1;
 378                         break;
 379                 default: /* not allowed to send an error here!? */
 380                         err = -EINVAL;
 381                         goto out;
 382                 }
 383                 /* fall through */
 384         case PNS_PEP_DISABLE_REQ:
 385                 atomic_set(&pn->tx_credits, 0);
 386                 pep_reply(sk, skb, PN_PIPE_NO_ERROR, NULL, 0, GFP_ATOMIC);
 387                 break;
 388
 389         case PNS_PEP_CTRL_REQ:
 390                 if (skb_queue_len(&pn->ctrlreq_queue) >= PNPIPE_CTRLREQ_MAX) {
 391                         atomic_inc(&sk->sk_drops);
 392                         break;
 393                 }
 394                 __skb_pull(skb, 4);
 395                 queue = &pn->ctrlreq_queue;
 396                 goto queue;
 397
 398         case PNS_PIPE_ALIGNED_DATA:
 399                 __skb_pull(skb, 1);
 400                 /* fall through */
 401         case PNS_PIPE_DATA:
 402                 __skb_pull(skb, 3); /* Pipe data header */
 403                 if (!pn_flow_safe(pn->rx_fc)) {
 404                         err = sock_queue_rcv_skb(sk, skb);
 405                         if (!err)
 406                                 return NET_RX_SUCCESS;
 407                         err = -ENOBUFS;
 408                         break;
 409                 }
 410
 411                 if (pn->rx_credits == 0) {
 412                         atomic_inc(&sk->sk_drops);
 413                         err = -ENOBUFS;
 414                         break;
 415                 }
 416                 pn->rx_credits--;
 417                 queue = &sk->sk_receive_queue;
 418                 goto queue;
 419
 420         case PNS_PEP_STATUS_IND:
 421                 pipe_rcv_status(sk, skb);
 422                 break;
 423
 424         case PNS_PIPE_REDIRECTED_IND:
 425                 err = pipe_rcv_created(sk, skb);
 426                 break;
 427
 428         case PNS_PIPE_CREATED_IND:
 429                 err = pipe_rcv_created(sk, skb);
 430                 if (err)
 431                         break;
 432                 /* fall through */
 433         case PNS_PIPE_RESET_IND:
 434                 if (!pn->init_enable)
 435                         break;
 436                 /* fall through */
 437         case PNS_PIPE_ENABLED_IND:
 438                 if (!pn_flow_safe(pn->tx_fc)) {
 439                         atomic_set(&pn->tx_credits, 1);
 440                         sk->sk_write_space(sk);
 441                 }
 442                 if (sk->sk_state == TCP_ESTABLISHED)
 443                         break; /* Nothing to do */
 444                 sk->sk_state = TCP_ESTABLISHED;
 445                 pipe_grant_credits(sk, GFP_ATOMIC);
 446                 break;
 447
 448         case PNS_PIPE_DISABLED_IND:
 449                 sk->sk_state = TCP_SYN_RECV;
 450                 pn->rx_credits = 0;
 451                 break;
 452
 453         default:
 454                 net_dbg_ratelimited("Phonet unknown PEP message: %u\n",
 455                                     hdr->message_id);
 456                 err = -EINVAL;
 457         }
 458 out:
 459         kfree_skb(skb);
 460         return (err == -ENOBUFS) ? NET_RX_DROP : NET_RX_SUCCESS;
 461
 462 queue:
 463         skb->dev = NULL;
 464         skb_set_owner_r(skb, sk);
 465         skb_queue_tail(queue, skb);
 466         if (!sock_flag(sk, SOCK_DEAD))
 467                 sk->sk_data_ready(sk);
 468         return NET_RX_SUCCESS;
 469 }
 470
 471 /* Destroy connected sock. */
 472 static void pipe_destruct(struct sock *sk)
 473 {
 474         struct pep_sock *pn = pep_sk(sk);
 475
 476         skb_queue_purge(&sk->sk_receive_queue);
 477         skb_queue_purge(&pn->ctrlreq_queue);
 478 }
 479
 480 static u8 pipe_negotiate_fc(const u8 *fcs, unsigned int n)
 481 {
 482         unsigned int i;
 483         u8 final_fc = PN_NO_FLOW_CONTROL;
 484
 485         for (i = 0; i < n; i++) {
 486                 u8 fc = fcs[i];
 487
 488                 if (fc > final_fc && fc < PN_MAX_FLOW_CONTROL)
 489                         final_fc = fc;
 490         }
 491         return final_fc;
 492 }
 493
 494 static int pep_connresp_rcv(struct sock *sk, struct sk_buff *skb)
 495 {
 496         struct pep_sock *pn = pep_sk(sk);
 497         struct pnpipehdr *hdr;
 498         u8 n_sb;
 499
 500         if (!pskb_pull(skb, sizeof(*hdr) + 4))
 501                 return -EINVAL;
 502
 503         hdr = pnp_hdr(skb);
 504         if (hdr->error_code != PN_PIPE_NO_ERROR)
 505                 return -ECONNREFUSED;
 506
 507         /* Parse sub-blocks */
 508         n_sb = hdr->data[3];
 509         while (n_sb > 0) {
 510                 u8 type, buf[6], len = sizeof(buf);
 511                 const u8 *data = pep_get_sb(skb, &type, &len, buf);
 512
 513                 if (data == NULL)
 514                         return -EINVAL;
 515
 516                 switch (type) {
 517                 case PN_PIPE_SB_REQUIRED_FC_TX:
 518                         if (len < 2 || len < data[0])
 519                                 break;
 520                         pn->tx_fc = pipe_negotiate_fc(data + 2, len - 2);
 521                         break;
 522
 523                 case PN_PIPE_SB_PREFERRED_FC_RX:
 524                         if (len < 2 || len < data[0])
 525                                 break;
 526                         pn->rx_fc = pipe_negotiate_fc(data + 2, len - 2);
 527                         break;
 528
 529                 }
 530                 n_sb--;
 531         }
 532
 533         return pipe_handler_send_created_ind(sk);
 534 }
 535
 536 static int pep_enableresp_rcv(struct sock *sk, struct sk_buff *skb)
 537 {
 538         struct pnpipehdr *hdr = pnp_hdr(skb);
 539
 540         if (hdr->error_code != PN_PIPE_NO_ERROR)
 541                 return -ECONNREFUSED;
 542
 543         return pep_indicate(sk, PNS_PIPE_ENABLED_IND, 0 /* sub-blocks */,
 544                 NULL, 0, GFP_ATOMIC);
 545
 546 }
 547
 548 static void pipe_start_flow_control(struct sock *sk)
 549 {
 550         struct pep_sock *pn = pep_sk(sk);
 551
 552         if (!pn_flow_safe(pn->tx_fc)) {
 553                 atomic_set(&pn->tx_credits, 1);
 554                 sk->sk_write_space(sk);
 555         }
 556         pipe_grant_credits(sk, GFP_ATOMIC);
 557 }
 558
 559 /* Queue an skb to an actively connected sock.
 560  * Socket lock must be held. */
 561 static int pipe_handler_do_rcv(struct sock *sk, struct sk_buff *skb)
 562 {
 563         struct pep_sock *pn = pep_sk(sk);
 564         struct pnpipehdr *hdr = pnp_hdr(skb);
 565         int err = NET_RX_SUCCESS;
 566
 567         switch (hdr->message_id) {
 568         case PNS_PIPE_ALIGNED_DATA:
 569                 __skb_pull(skb, 1);
 570                 /* fall through */
 571         case PNS_PIPE_DATA:
 572                 __skb_pull(skb, 3); /* Pipe data header */
 573                 if (!pn_flow_safe(pn->rx_fc)) {
 574                         err = sock_queue_rcv_skb(sk, skb);
 575                         if (!err)
 576                                 return NET_RX_SUCCESS;
 577                         err = NET_RX_DROP;
 578                         break;
 579                 }
 580
 581                 if (pn->rx_credits == 0) {
 582                         atomic_inc(&sk->sk_drops);
 583                         err = NET_RX_DROP;
 584                         break;
 585                 }
 586                 pn->rx_credits--;
 587                 skb->dev = NULL;
 588                 skb_set_owner_r(skb, sk);
 589                 skb_queue_tail(&sk->sk_receive_queue, skb);
 590                 if (!sock_flag(sk, SOCK_DEAD))
 591                         sk->sk_data_ready(sk);
 592                 return NET_RX_SUCCESS;
 593
 594         case PNS_PEP_CONNECT_RESP:
 595                 if (sk->sk_state != TCP_SYN_SENT)
 596                         break;
 597                 if (!sock_flag(sk, SOCK_DEAD))
 598                         sk->sk_state_change(sk);
 599                 if (pep_connresp_rcv(sk, skb)) {
 600                         sk->sk_state = TCP_CLOSE_WAIT;
 601                         break;
 602                 }
 603                 if (pn->init_enable == PN_PIPE_DISABLE)
 604                         sk->sk_state = TCP_SYN_RECV;
 605                 else {
 606                         sk->sk_state = TCP_ESTABLISHED;
 607                         pipe_start_flow_control(sk);
 608                 }
 609                 break;
 610
 611         case PNS_PEP_ENABLE_RESP:
 612                 if (sk->sk_state != TCP_SYN_SENT)
 613                         break;
 614
 615                 if (pep_enableresp_rcv(sk, skb)) {
 616                         sk->sk_state = TCP_CLOSE_WAIT;
 617                         break;
 618                 }
 619
 620                 sk->sk_state = TCP_ESTABLISHED;
 621                 pipe_start_flow_control(sk);
 622                 break;
 623
 624         case PNS_PEP_DISCONNECT_RESP:
 625                 /* sock should already be dead, nothing to do */
 626                 break;
 627
 628         case PNS_PEP_STATUS_IND:
 629                 pipe_rcv_status(sk, skb);
 630                 break;
 631         }
 632         kfree_skb(skb);
 633         return err;
 634 }
 635
 636 /* Listening sock must be locked */
 637 static struct sock *pep_find_pipe(const struct hlist_head *hlist,
 638                                         const struct sockaddr_pn *dst,
 639                                         u8 pipe_handle)
 640 {
 641         struct sock *sknode;
 642         u16 dobj = pn_sockaddr_get_object(dst);
 643
 644         sk_for_each(sknode, hlist) {
 645                 struct pep_sock *pnnode = pep_sk(sknode);
 646
 647                 /* Ports match, but addresses might not: */
 648                 if (pnnode->pn_sk.sobject != dobj)
 649                         continue;
 650                 if (pnnode->pipe_handle != pipe_handle)
 651                         continue;
 652                 if (sknode->sk_state == TCP_CLOSE_WAIT)
 653                         continue;
 654
 655                 sock_hold(sknode);
 656                 return sknode;
 657         }
 658         return NULL;
 659 }
 660
 661 /*
 662  * Deliver an skb to a listening sock.
 663  * Socket lock must be held.
 664  * We then queue the skb to the right connected sock (if any).
 665  */
 666 static int pep_do_rcv(struct sock *sk, struct sk_buff *skb)
 667 {
 668         struct pep_sock *pn = pep_sk(sk);
 669         struct sock *sknode;
 670         struct pnpipehdr *hdr;
 671         struct sockaddr_pn dst;
 672         u8 pipe_handle;
 673
 674         if (!pskb_may_pull(skb, sizeof(*hdr)))
 675                 goto drop;
 676
 677         hdr = pnp_hdr(skb);
 678         pipe_handle = hdr->pipe_handle;
 679         if (pipe_handle == PN_PIPE_INVALID_HANDLE)
 680                 goto drop;
 681
 682         pn_skb_get_dst_sockaddr(skb, &dst);
 683
 684         /* Look for an existing pipe handle */
 685         sknode = pep_find_pipe(&pn->hlist, &dst, pipe_handle);
 686         if (sknode)
 687                 return sk_receive_skb(sknode, skb, 1);
 688
 689         switch (hdr->message_id) {
 690         case PNS_PEP_CONNECT_REQ:
 691                 if (sk->sk_state != TCP_LISTEN || sk_acceptq_is_full(sk)) {
 692                         pep_reject_conn(sk, skb, PN_PIPE_ERR_PEP_IN_USE,
 693                                         GFP_ATOMIC);
 694                         break;
 695                 }
 696                 skb_queue_head(&sk->sk_receive_queue, skb);
 697                 sk_acceptq_added(sk);
 698                 if (!sock_flag(sk, SOCK_DEAD))
 699                         sk->sk_data_ready(sk);
 700                 return NET_RX_SUCCESS;
 701
 702         case PNS_PEP_DISCONNECT_REQ:
 703                 pep_reply(sk, skb, PN_PIPE_NO_ERROR, NULL, 0, GFP_ATOMIC);
 704                 break;
 705
 706         case PNS_PEP_CTRL_REQ:
 707                 pep_ctrlreq_error(sk, skb, PN_PIPE_INVALID_HANDLE, GFP_ATOMIC);
 708                 break;
 709
 710         case PNS_PEP_RESET_REQ:
 711         case PNS_PEP_ENABLE_REQ:
 712         case PNS_PEP_DISABLE_REQ:
 713                 /* invalid handle is not even allowed here! */
 714                 break;
 715
 716         default:
 717                 if ((1 << sk->sk_state)
 718                                 & ~(TCPF_CLOSE|TCPF_LISTEN|TCPF_CLOSE_WAIT))
 719                         /* actively connected socket */
 720                         return pipe_handler_do_rcv(sk, skb);
 721         }
 722 drop:
 723         kfree_skb(skb);
 724         return NET_RX_SUCCESS;
 725 }
 726
 727 static int pipe_do_remove(struct sock *sk)
 728 {
 729         struct pep_sock *pn = pep_sk(sk);
 730         struct pnpipehdr *ph;
 731         struct sk_buff *skb;
 732
 733         skb = pep_alloc_skb(sk, NULL, 0, GFP_KERNEL);
 734         if (!skb)
 735                 return -ENOMEM;
 736
 737         ph = pnp_hdr(skb);
 738         ph->utid = 0;
 739         ph->message_id = PNS_PIPE_REMOVE_REQ;
 740         ph->pipe_handle = pn->pipe_handle;
 741         ph->data0 = PAD;
 742         return pn_skb_send(sk, skb, NULL);
 743 }
 744
 745 /* associated socket ceases to exist */
 746 static void pep_sock_close(struct sock *sk, long timeout)
 747 {
 748         struct pep_sock *pn = pep_sk(sk);
 749         int ifindex = 0;
 750
 751         sock_hold(sk); /* keep a reference after sk_common_release() */
 752         sk_common_release(sk);
 753
 754         lock_sock(sk);
 755         if ((1 << sk->sk_state) & (TCPF_SYN_RECV|TCPF_ESTABLISHED)) {
 756                 if (sk->sk_backlog_rcv == pipe_do_rcv)
 757                         /* Forcefully remove dangling Phonet pipe */
 758                         pipe_do_remove(sk);
 759                 else
 760                         pipe_handler_request(sk, PNS_PEP_DISCONNECT_REQ, PAD,
 761                                                 NULL, 0);
 762         }
 763         sk->sk_state = TCP_CLOSE;
 764
 765         ifindex = pn->ifindex;
 766         pn->ifindex = 0;
 767         release_sock(sk);
 768
 769         if (ifindex)
 770                 gprs_detach(sk);
 771         sock_put(sk);
 772 }
 773
 774 static struct sock *pep_sock_accept(struct sock *sk, int flags, int *errp)
 775 {
 776         struct pep_sock *pn = pep_sk(sk), *newpn;
 777         struct sock *newsk = NULL;
 778         struct sk_buff *skb;
 779         struct pnpipehdr *hdr;
 780         struct sockaddr_pn dst, src;
 781         int err;
 782         u16 peer_type;
 783         u8 pipe_handle, enabled, n_sb;
 784         u8 aligned = 0;
 785
 786         skb = skb_recv_datagram(sk, 0, flags & O_NONBLOCK, errp);
 787         if (!skb)
 788                 return NULL;
 789
 790         lock_sock(sk);
 791         if (sk->sk_state != TCP_LISTEN) {
 792                 err = -EINVAL;
 793                 goto drop;
 794         }
 795         sk_acceptq_removed(sk);
 796
 797         err = -EPROTO;
 798         if (!pskb_may_pull(skb, sizeof(*hdr) + 4))
 799                 goto drop;
 800
 801         hdr = pnp_hdr(skb);
 802         pipe_handle = hdr->pipe_handle;
 803         switch (hdr->state_after_connect) {
 804         case PN_PIPE_DISABLE:
 805                 enabled = 0;
 806                 break;
 807         case PN_PIPE_ENABLE:
 808                 enabled = 1;
 809                 break;
 810         default:
 811                 pep_reject_conn(sk, skb, PN_PIPE_ERR_INVALID_PARAM,
 812                                 GFP_KERNEL);
 813                 goto drop;
 814         }
 815         peer_type = hdr->other_pep_type << 8;
 816
 817         /* Parse sub-blocks (options) */
 818         n_sb = hdr->data[3];
 819         while (n_sb > 0) {
 820                 u8 type, buf[1], len = sizeof(buf);
 821                 const u8 *data = pep_get_sb(skb, &type, &len, buf);
 822
 823                 if (data == NULL)
 824                         goto drop;
 825                 switch (type) {
 826                 case PN_PIPE_SB_CONNECT_REQ_PEP_SUB_TYPE:
 827                         if (len < 1)
 828                                 goto drop;
 829                         peer_type = (peer_type & 0xff00) | data[0];
 830                         break;
 831                 case PN_PIPE_SB_ALIGNED_DATA:
 832                         aligned = data[0] != 0;
 833                         break;
 834                 }
 835                 n_sb--;
 836         }
 837
 838         /* Check for duplicate pipe handle */
 839         newsk = pep_find_pipe(&pn->hlist, &dst, pipe_handle);
 840         if (unlikely(newsk)) {
 841                 __sock_put(newsk);
 842                 newsk = NULL;
 843                 pep_reject_conn(sk, skb, PN_PIPE_ERR_PEP_IN_USE, GFP_KERNEL);
 844                 goto drop;
 845         }
 846
 847         /* Create a new to-be-accepted sock */
 848         newsk = sk_alloc(sock_net(sk), PF_PHONET, GFP_KERNEL, sk->sk_prot, 0);
 849         if (!newsk) {
 850                 pep_reject_conn(sk, skb, PN_PIPE_ERR_OVERLOAD, GFP_KERNEL);
 851                 err = -ENOBUFS;
 852                 goto drop;
 853         }
 854
 855         sock_init_data(NULL, newsk);
 856         newsk->sk_state = TCP_SYN_RECV;
 857         newsk->sk_backlog_rcv = pipe_do_rcv;
 858         newsk->sk_protocol = sk->sk_protocol;
 859         newsk->sk_destruct = pipe_destruct;
 860
 861         newpn = pep_sk(newsk);
 862         pn_skb_get_dst_sockaddr(skb, &dst);
 863         pn_skb_get_src_sockaddr(skb, &src);
 864         newpn->pn_sk.sobject = pn_sockaddr_get_object(&dst);
 865         newpn->pn_sk.dobject = pn_sockaddr_get_object(&src);
 866         newpn->pn_sk.resource = pn_sockaddr_get_resource(&dst);
 867         sock_hold(sk);
 868         newpn->listener = sk;
 869         skb_queue_head_init(&newpn->ctrlreq_queue);
 870         newpn->pipe_handle = pipe_handle;
 871         atomic_set(&newpn->tx_credits, 0);
 872         newpn->ifindex = 0;
 873         newpn->peer_type = peer_type;
 874         newpn->rx_credits = 0;
 875         newpn->rx_fc = newpn->tx_fc = PN_LEGACY_FLOW_CONTROL;
 876         newpn->init_enable = enabled;
 877         newpn->aligned = aligned;
 878
 879         err = pep_accept_conn(newsk, skb);
 880         if (err) {
 881                 __sock_put(sk);
 882                 sock_put(newsk);
 883                 newsk = NULL;
 884                 goto drop;
 885         }
 886         sk_add_node(newsk, &pn->hlist);
 887 drop:
 888         release_sock(sk);
 889         kfree_skb(skb);
 890         *errp = err;
 891         return newsk;
 892 }
 893
 894 static int pep_sock_connect(struct sock *sk, struct sockaddr *addr, int len)
 895 {
 896         struct pep_sock *pn = pep_sk(sk);
 897         int err;
 898         u8 data[4] = { 0 /* sub-blocks */, PAD, PAD, PAD };
 899
 900         if (pn->pipe_handle == PN_PIPE_INVALID_HANDLE)
 901                 pn->pipe_handle = 1; /* anything but INVALID_HANDLE */
 902
 903         err = pipe_handler_request(sk, PNS_PEP_CONNECT_REQ,
 904                                 pn->init_enable, data, 4);
 905         if (err) {
 906                 pn->pipe_handle = PN_PIPE_INVALID_HANDLE;
 907                 return err;
 908         }
 909
 910         sk->sk_state = TCP_SYN_SENT;
 911
 912         return 0;
 913 }
 914
 915 static int pep_sock_enable(struct sock *sk, struct sockaddr *addr, int len)
 916 {
 917         int err;
 918
 919         err = pipe_handler_request(sk, PNS_PEP_ENABLE_REQ, PAD,
 920                                 NULL, 0);
 921         if (err)
 922                 return err;
 923
 924         sk->sk_state = TCP_SYN_SENT;
 925
 926         return 0;
 927 }
 928
 929 static int pep_ioctl(struct sock *sk, int cmd, unsigned long arg)
 930 {
 931         struct pep_sock *pn = pep_sk(sk);
 932         int answ;
 933         int ret = -ENOIOCTLCMD;
 934
 935         switch (cmd) {
 936         case SIOCINQ:
 937                 if (sk->sk_state == TCP_LISTEN) {
 938                         ret = -EINVAL;
 939                         break;
 940                 }
 941
 942                 lock_sock(sk);
 943                 if (sock_flag(sk, SOCK_URGINLINE) &&
 944                     !skb_queue_empty(&pn->ctrlreq_queue))
 945                         answ = skb_peek(&pn->ctrlreq_queue)->len;
 946                 else if (!skb_queue_empty(&sk->sk_receive_queue))
 947                         answ = skb_peek(&sk->sk_receive_queue)->len;
 948                 else
 949                         answ = 0;
 950                 release_sock(sk);
 951                 ret = put_user(answ, (int __user *)arg);
 952                 break;
 953
 954         case SIOCPNENABLEPIPE:
 955                 lock_sock(sk);
 956                 if (sk->sk_state == TCP_SYN_SENT)
 957                         ret =  -EBUSY;
 958                 else if (sk->sk_state == TCP_ESTABLISHED)
 959                         ret = -EISCONN;
 960                 else if (!pn->pn_sk.sobject)
 961                         ret = -EADDRNOTAVAIL;
 962                 else
 963                         ret = pep_sock_enable(sk, NULL, 0);
 964                 release_sock(sk);
 965                 break;
 966         }
 967
 968         return ret;
 969 }
 970
 971 static int pep_init(struct sock *sk)
 972 {
 973         struct pep_sock *pn = pep_sk(sk);
 974
 975         sk->sk_destruct = pipe_destruct;
 976         INIT_HLIST_HEAD(&pn->hlist);
 977         pn->listener = NULL;
 978         skb_queue_head_init(&pn->ctrlreq_queue);
 979         atomic_set(&pn->tx_credits, 0);
 980         pn->ifindex = 0;
 981         pn->peer_type = 0;
 982         pn->pipe_handle = PN_PIPE_INVALID_HANDLE;
 983         pn->rx_credits = 0;
 984         pn->rx_fc = pn->tx_fc = PN_LEGACY_FLOW_CONTROL;
 985         pn->init_enable = 1;
 986         pn->aligned = 0;
 987         return 0;
 988 }
 989
 990 static int pep_setsockopt(struct sock *sk, int level, int optname,
 991                                 char __user *optval, unsigned int optlen)
 992 {
 993         struct pep_sock *pn = pep_sk(sk);
 994         int val = 0, err = 0;
 995
 996         if (level != SOL_PNPIPE)
 997                 return -ENOPROTOOPT;
 998         if (optlen >= sizeof(int)) {
 999                 if (get_user(val, (int __user *) optval))
1000                         return -EFAULT;
1001         }
1002
1003         lock_sock(sk);
1004         switch (optname) {
1005         case PNPIPE_ENCAP:
1006                 if (val && val != PNPIPE_ENCAP_IP) {
1007                         err = -EINVAL;
1008                         break;
1009                 }
1010                 if (!pn->ifindex == !val)
1011                         break; /* Nothing to do! */
1012                 if (!capable(CAP_NET_ADMIN)) {
1013                         err = -EPERM;
1014                         break;
1015                 }
1016                 if (val) {
1017                         release_sock(sk);
1018                         err = gprs_attach(sk);
1019                         if (err > 0) {
1020                                 pn->ifindex = err;
1021                                 err = 0;
1022                         }
1023                 } else {
1024                         pn->ifindex = 0;
1025                         release_sock(sk);
1026                         gprs_detach(sk);
1027                         err = 0;
1028                 }
1029                 goto out_norel;
1030
1031         case PNPIPE_HANDLE:
1032                 if ((sk->sk_state == TCP_CLOSE) &&
1033                         (val >= 0) && (val < PN_PIPE_INVALID_HANDLE))
1034                         pn->pipe_handle = val;
1035                 else
1036                         err = -EINVAL;
1037                 break;
1038
1039         case PNPIPE_INITSTATE:
1040                 pn->init_enable = !!val;
1041                 break;
1042
1043         default:
1044                 err = -ENOPROTOOPT;
1045         }
1046         release_sock(sk);
1047
1048 out_norel:
1049         return err;
1050 }
1051
1052 static int pep_getsockopt(struct sock *sk, int level, int optname,
1053                                 char __user *optval, int __user *optlen)
1054 {
1055         struct pep_sock *pn = pep_sk(sk);
1056         int len, val;
1057
1058         if (level != SOL_PNPIPE)
1059                 return -ENOPROTOOPT;
1060         if (get_user(len, optlen))
1061                 return -EFAULT;
1062
1063         switch (optname) {
1064         case PNPIPE_ENCAP:
1065                 val = pn->ifindex ? PNPIPE_ENCAP_IP : PNPIPE_ENCAP_NONE;
1066                 break;
1067
1068         case PNPIPE_IFINDEX:
1069                 val = pn->ifindex;
1070                 break;
1071
1072         case PNPIPE_HANDLE:
1073                 val = pn->pipe_handle;
1074                 if (val == PN_PIPE_INVALID_HANDLE)
1075                         return -EINVAL;
1076                 break;
1077
1078         case PNPIPE_INITSTATE:
1079                 val = pn->init_enable;
1080                 break;
1081
1082         default:
1083                 return -ENOPROTOOPT;
1084         }
1085
1086         len = min_t(unsigned int, sizeof(int), len);
1087         if (put_user(len, optlen))
1088                 return -EFAULT;
1089         if (put_user(val, (int __user *) optval))
1090                 return -EFAULT;
1091         return 0;
1092 }
1093
1094 static int pipe_skb_send(struct sock *sk, struct sk_buff *skb)
1095 {
1096         struct pep_sock *pn = pep_sk(sk);
1097         struct pnpipehdr *ph;
1098         int err;
1099
1100         if (pn_flow_safe(pn->tx_fc) &&
1101             !atomic_add_unless(&pn->tx_credits, -1, 0)) {
1102                 kfree_skb(skb);
1103                 return -ENOBUFS;
1104         }
1105
1106         skb_push(skb, 3 + pn->aligned);
1107         skb_reset_transport_header(skb);
1108         ph = pnp_hdr(skb);
1109         ph->utid = 0;
1110         if (pn->aligned) {
1111                 ph->message_id = PNS_PIPE_ALIGNED_DATA;
1112                 ph->data0 = 0; /* padding */
1113         } else
1114                 ph->message_id = PNS_PIPE_DATA;
1115         ph->pipe_handle = pn->pipe_handle;
1116         err = pn_skb_send(sk, skb, NULL);
1117
1118         if (err && pn_flow_safe(pn->tx_fc))
1119                 atomic_inc(&pn->tx_credits);
1120         return err;
1121
1122 }
1123
1124 static int pep_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
1125 {
1126         struct pep_sock *pn = pep_sk(sk);
1127         struct sk_buff *skb;
1128         long timeo;
1129         int flags = msg->msg_flags;
1130         int err, done;
1131
1132         if (len > USHRT_MAX)
1133                 return -EMSGSIZE;
1134
1135         if ((msg->msg_flags & ~(MSG_DONTWAIT|MSG_EOR|MSG_NOSIGNAL|
1136                                 MSG_CMSG_COMPAT)) ||
1137                         !(msg->msg_flags & MSG_EOR))
1138                 return -EOPNOTSUPP;
1139
1140         skb = sock_alloc_send_skb(sk, MAX_PNPIPE_HEADER + len,
1141                                         flags & MSG_DONTWAIT, &err);
1142         if (!skb)
1143                 return err;
1144
1145         skb_reserve(skb, MAX_PHONET_HEADER + 3 + pn->aligned);
1146         err = memcpy_from_msg(skb_put(skb, len), msg, len);
1147         if (err < 0)
1148                 goto outfree;
1149
1150         lock_sock(sk);
1151         timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT);
1152         if ((1 << sk->sk_state) & (TCPF_LISTEN|TCPF_CLOSE)) {
1153                 err = -ENOTCONN;
1154                 goto out;
1155         }
1156         if (sk->sk_state != TCP_ESTABLISHED) {
1157                 /* Wait until the pipe gets to enabled state */
1158 disabled:
1159                 err = sk_stream_wait_connect(sk, &timeo);
1160                 if (err)
1161                         goto out;
1162
1163                 if (sk->sk_state == TCP_CLOSE_WAIT) {
1164                         err = -ECONNRESET;
1165                         goto out;
1166                 }
1167         }
1168         BUG_ON(sk->sk_state != TCP_ESTABLISHED);
1169
1170         /* Wait until flow control allows TX */
1171         done = atomic_read(&pn->tx_credits);
1172         while (!done) {
1173                 DEFINE_WAIT(wait);
1174
1175                 if (!timeo) {
1176                         err = -EAGAIN;
1177                         goto out;
1178                 }
1179                 if (signal_pending(current)) {
1180                         err = sock_intr_errno(timeo);
1181                         goto out;
1182                 }
1183
1184                 prepare_to_wait(sk_sleep(sk), &wait,
1185                                 TASK_INTERRUPTIBLE);
1186                 done = sk_wait_event(sk, &timeo, atomic_read(&pn->tx_credits));
1187                 finish_wait(sk_sleep(sk), &wait);
1188
1189                 if (sk->sk_state != TCP_ESTABLISHED)
1190                         goto disabled;
1191         }
1192
1193         err = pipe_skb_send(sk, skb);
1194         if (err >= 0)
1195                 err = len; /* success! */
1196         skb = NULL;
1197 out:
1198         release_sock(sk);
1199 outfree:
1200         kfree_skb(skb);
1201         return err;
1202 }
1203
1204 int pep_writeable(struct sock *sk)
1205 {
1206         struct pep_sock *pn = pep_sk(sk);
1207
1208         return atomic_read(&pn->tx_credits);
1209 }
1210
1211 int pep_write(struct sock *sk, struct sk_buff *skb)
1212 {
1213         struct sk_buff *rskb, *fs;
1214         int flen = 0;
1215
1216         if (pep_sk(sk)->aligned)
1217                 return pipe_skb_send(sk, skb);
1218
1219         rskb = alloc_skb(MAX_PNPIPE_HEADER, GFP_ATOMIC);
1220         if (!rskb) {
1221                 kfree_skb(skb);
1222                 return -ENOMEM;
1223         }
1224         skb_shinfo(rskb)->frag_list = skb;
1225         rskb->len += skb->len;
1226         rskb->data_len += rskb->len;
1227         rskb->truesize += rskb->len;
1228
1229         /* Avoid nested fragments */
1230         skb_walk_frags(skb, fs)
1231                 flen += fs->len;
1232         skb->next = skb_shinfo(skb)->frag_list;
1233         skb_frag_list_init(skb);
1234         skb->len -= flen;
1235         skb->data_len -= flen;
1236         skb->truesize -= flen;
1237
1238         skb_reserve(rskb, MAX_PHONET_HEADER + 3);
1239         return pipe_skb_send(sk, rskb);
1240 }
1241
1242 struct sk_buff *pep_read(struct sock *sk)
1243 {
1244         struct sk_buff *skb = skb_dequeue(&sk->sk_receive_queue);
1245
1246         if (sk->sk_state == TCP_ESTABLISHED)
1247                 pipe_grant_credits(sk, GFP_ATOMIC);
1248         return skb;
1249 }
1250
1251 static int pep_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
1252                        int noblock, int flags, int *addr_len)
1253 {
1254         struct sk_buff *skb;
1255         int err;
1256
1257         if (flags & ~(MSG_OOB|MSG_PEEK|MSG_TRUNC|MSG_DONTWAIT|MSG_WAITALL|
1258                         MSG_NOSIGNAL|MSG_CMSG_COMPAT))
1259                 return -EOPNOTSUPP;
1260
1261         if (unlikely(1 << sk->sk_state & (TCPF_LISTEN | TCPF_CLOSE)))
1262                 return -ENOTCONN;
1263
1264         if ((flags & MSG_OOB) || sock_flag(sk, SOCK_URGINLINE)) {
1265                 /* Dequeue and acknowledge control request */
1266                 struct pep_sock *pn = pep_sk(sk);
1267
1268                 if (flags & MSG_PEEK)
1269                         return -EOPNOTSUPP;
1270                 skb = skb_dequeue(&pn->ctrlreq_queue);
1271                 if (skb) {
1272                         pep_ctrlreq_error(sk, skb, PN_PIPE_NO_ERROR,
1273                                                 GFP_KERNEL);
1274                         msg->msg_flags |= MSG_OOB;
1275                         goto copy;
1276                 }
1277                 if (flags & MSG_OOB)
1278                         return -EINVAL;
1279         }
1280
1281         skb = skb_recv_datagram(sk, flags, noblock, &err);
1282         lock_sock(sk);
1283         if (skb == NULL) {
1284                 if (err == -ENOTCONN && sk->sk_state == TCP_CLOSE_WAIT)
1285                         err = -ECONNRESET;
1286                 release_sock(sk);
1287                 return err;
1288         }
1289
1290         if (sk->sk_state == TCP_ESTABLISHED)
1291                 pipe_grant_credits(sk, GFP_KERNEL);
1292         release_sock(sk);
1293 copy:
1294         msg->msg_flags |= MSG_EOR;
1295         if (skb->len > len)
1296                 msg->msg_flags |= MSG_TRUNC;
1297         else
1298                 len = skb->len;
1299
1300         err = skb_copy_datagram_msg(skb, 0, msg, len);
1301         if (!err)
1302                 err = (flags & MSG_TRUNC) ? skb->len : len;
1303
1304         skb_free_datagram(sk, skb);
1305         return err;
1306 }
1307
1308 static void pep_sock_unhash(struct sock *sk)
1309 {
1310         struct pep_sock *pn = pep_sk(sk);
1311         struct sock *skparent = NULL;
1312
1313         lock_sock(sk);
1314
1315         if (pn->listener != NULL) {
1316                 skparent = pn->listener;
1317                 pn->listener = NULL;
1318                 release_sock(sk);
1319
1320                 pn = pep_sk(skparent);
1321                 lock_sock(skparent);
1322                 sk_del_node_init(sk);
1323                 sk = skparent;
1324         }
1325
1326         /* Unhash a listening sock only when it is closed
1327          * and all of its active connected pipes are closed. */
1328         if (hlist_empty(&pn->hlist))
1329                 pn_sock_unhash(&pn->pn_sk.sk);
1330         release_sock(sk);
1331
1332         if (skparent)
1333                 sock_put(skparent);
1334 }
1335
1336 static struct proto pep_proto = {
1337         .close          = pep_sock_close,
1338         .accept         = pep_sock_accept,
1339         .connect        = pep_sock_connect,
1340         .ioctl          = pep_ioctl,
1341         .init           = pep_init,
1342         .setsockopt     = pep_setsockopt,
1343         .getsockopt     = pep_getsockopt,
1344         .sendmsg        = pep_sendmsg,
1345         .recvmsg        = pep_recvmsg,
1346         .backlog_rcv    = pep_do_rcv,
1347         .hash           = pn_sock_hash,
1348         .unhash         = pep_sock_unhash,
1349         .get_port       = pn_sock_get_port,
1350         .obj_size       = sizeof(struct pep_sock),
1351         .owner          = THIS_MODULE,
1352         .name           = "PNPIPE",
1353 };
1354
1355 static struct phonet_protocol pep_pn_proto = {
1356         .ops            = &phonet_stream_ops,
1357         .prot           = &pep_proto,
1358         .sock_type      = SOCK_SEQPACKET,
1359 };
1360
1361 static int __init pep_register(void)
1362 {
1363         return phonet_proto_register(PN_PROTO_PIPE, &pep_pn_proto);
1364 }
1365
1366 static void __exit pep_unregister(void)
1367 {
1368         phonet_proto_unregister(PN_PROTO_PIPE, &pep_pn_proto);
1369 }
1370
1371 module_init(pep_register);
1372 module_exit(pep_unregister);
1373 MODULE_AUTHOR("Remi Denis-Courmont, Nokia");
1374 MODULE_DESCRIPTION("Phonet pipe protocol");
1375 MODULE_LICENSE("GPL");
1376 MODULE_ALIAS_NET_PF_PROTO(PF_PHONET, PN_PROTO_PIPE);