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   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 <remi.denis-courmont@nokia.com>
   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 <net/phonet/phonet.h>
  34 #include <net/phonet/pep.h>
  35 #include <net/phonet/gprs.h>
  36
  37 /* sk_state values:
  38  * TCP_CLOSE            sock not in use yet
  39  * TCP_CLOSE_WAIT       disconnected pipe
  40  * TCP_LISTEN           listening pipe endpoint
  41  * TCP_SYN_RECV         connected pipe in disabled state
  42  * TCP_ESTABLISHED      connected pipe in enabled state
  43  *
  44  * pep_sock locking:
  45  *  - sk_state, ackq, hlist: sock lock needed
  46  *  - listener: read only
  47  *  - pipe_handle: read only
  48  */
  49
  50 #define CREDITS_MAX     10
  51 #define CREDITS_THR     7
  52
  53 static const struct sockaddr_pn pipe_srv = {
  54         .spn_family = AF_PHONET,
  55         .spn_resource = 0xD9, /* pipe service */
  56 };
  57
  58 #define pep_sb_size(s) (((s) + 5) & ~3) /* 2-bytes head, 32-bits aligned */
  59
  60 /* Get the next TLV sub-block. */
  61 static unsigned char *pep_get_sb(struct sk_buff *skb, u8 *ptype, u8 *plen,
  62                                         void *buf)
  63 {
  64         void *data = NULL;
  65         struct {
  66                 u8 sb_type;
  67                 u8 sb_len;
  68         } *ph, h;
  69         int buflen = *plen;
  70
  71         ph = skb_header_pointer(skb, 0, 2, &h);
  72         if (ph == NULL || ph->sb_len < 2 || !pskb_may_pull(skb, ph->sb_len))
  73                 return NULL;
  74         ph->sb_len -= 2;
  75         *ptype = ph->sb_type;
  76         *plen = ph->sb_len;
  77
  78         if (buflen > ph->sb_len)
  79                 buflen = ph->sb_len;
  80         data = skb_header_pointer(skb, 2, buflen, buf);
  81         __skb_pull(skb, 2 + ph->sb_len);
  82         return data;
  83 }
  84
  85 static int pep_reply(struct sock *sk, struct sk_buff *oskb,
  86                         u8 code, 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
  92         skb = alloc_skb(MAX_PNPIPE_HEADER + len, priority);
  93         if (!skb)
  94                 return -ENOMEM;
  95         skb_set_owner_w(skb, sk);
  96
  97         skb_reserve(skb, MAX_PNPIPE_HEADER);
  98         __skb_put(skb, len);
  99         skb_copy_to_linear_data(skb, data, len);
 100         __skb_push(skb, sizeof(*ph));
 101         skb_reset_transport_header(skb);
 102         ph = pnp_hdr(skb);
 103         ph->utid = oph->utid;
 104         ph->message_id = oph->message_id + 1; /* REQ -> RESP */
 105         ph->pipe_handle = oph->pipe_handle;
 106         ph->error_code = code;
 107
 108         return pn_skb_send(sk, skb, &pipe_srv);
 109 }
 110
 111 #define PAD 0x00
 112 static int pep_accept_conn(struct sock *sk, struct sk_buff *skb)
 113 {
 114         static const u8 data[20] = {
 115                 PAD, PAD, PAD, 2 /* sub-blocks */,
 116                 PN_PIPE_SB_REQUIRED_FC_TX, pep_sb_size(5), 3, PAD,
 117                         PN_MULTI_CREDIT_FLOW_CONTROL,
 118                         PN_ONE_CREDIT_FLOW_CONTROL,
 119                         PN_LEGACY_FLOW_CONTROL,
 120                         PAD,
 121                 PN_PIPE_SB_PREFERRED_FC_RX, pep_sb_size(5), 3, PAD,
 122                         PN_MULTI_CREDIT_FLOW_CONTROL,
 123                         PN_ONE_CREDIT_FLOW_CONTROL,
 124                         PN_LEGACY_FLOW_CONTROL,
 125                         PAD,
 126         };
 127
 128         might_sleep();
 129         return pep_reply(sk, skb, PN_PIPE_NO_ERROR, data, sizeof(data),
 130                                 GFP_KERNEL);
 131 }
 132
 133 static int pep_reject_conn(struct sock *sk, struct sk_buff *skb, u8 code)
 134 {
 135         static const u8 data[4] = { PAD, PAD, PAD, 0 /* sub-blocks */ };
 136         WARN_ON(code == PN_PIPE_NO_ERROR);
 137         return pep_reply(sk, skb, code, data, sizeof(data), GFP_ATOMIC);
 138 }
 139
 140 /* Control requests are not sent by the pipe service and have a specific
 141  * message format. */
 142 static int pep_ctrlreq_error(struct sock *sk, struct sk_buff *oskb, u8 code,
 143                                 gfp_t priority)
 144 {
 145         const struct pnpipehdr *oph = pnp_hdr(oskb);
 146         struct sk_buff *skb;
 147         struct pnpipehdr *ph;
 148         struct sockaddr_pn dst;
 149
 150         skb = alloc_skb(MAX_PNPIPE_HEADER + 4, priority);
 151         if (!skb)
 152                 return -ENOMEM;
 153         skb_set_owner_w(skb, sk);
 154
 155         skb_reserve(skb, MAX_PHONET_HEADER);
 156         ph = (struct pnpipehdr *)skb_put(skb, sizeof(*ph) + 4);
 157
 158         ph->utid = oph->utid;
 159         ph->message_id = PNS_PEP_CTRL_RESP;
 160         ph->pipe_handle = oph->pipe_handle;
 161         ph->data[0] = oph->data[1]; /* CTRL id */
 162         ph->data[1] = oph->data[0]; /* PEP type */
 163         ph->data[2] = code; /* error code, at an usual offset */
 164         ph->data[3] = PAD;
 165         ph->data[4] = PAD;
 166
 167         pn_skb_get_src_sockaddr(oskb, &dst);
 168         return pn_skb_send(sk, skb, &dst);
 169 }
 170
 171 static int pipe_snd_status(struct sock *sk, u8 type, u8 status, gfp_t priority)
 172 {
 173         struct pep_sock *pn = pep_sk(sk);
 174         struct pnpipehdr *ph;
 175         struct sk_buff *skb;
 176
 177         skb = alloc_skb(MAX_PNPIPE_HEADER + 4, priority);
 178         if (!skb)
 179                 return -ENOMEM;
 180         skb_set_owner_w(skb, sk);
 181
 182         skb_reserve(skb, MAX_PNPIPE_HEADER + 4);
 183         __skb_push(skb, sizeof(*ph) + 4);
 184         skb_reset_transport_header(skb);
 185         ph = pnp_hdr(skb);
 186         ph->utid = 0;
 187         ph->message_id = PNS_PEP_STATUS_IND;
 188         ph->pipe_handle = pn->pipe_handle;
 189         ph->pep_type = PN_PEP_TYPE_COMMON;
 190         ph->data[1] = type;
 191         ph->data[2] = PAD;
 192         ph->data[3] = PAD;
 193         ph->data[4] = status;
 194
 195         return pn_skb_send(sk, skb, &pipe_srv);
 196 }
 197
 198 /* Send our RX flow control information to the sender.
 199  * Socket must be locked. */
 200 static void pipe_grant_credits(struct sock *sk)
 201 {
 202         struct pep_sock *pn = pep_sk(sk);
 203
 204         BUG_ON(sk->sk_state != TCP_ESTABLISHED);
 205
 206         switch (pn->rx_fc) {
 207         case PN_LEGACY_FLOW_CONTROL: /* TODO */
 208                 break;
 209         case PN_ONE_CREDIT_FLOW_CONTROL:
 210                 pipe_snd_status(sk, PN_PEP_IND_FLOW_CONTROL,
 211                                 PEP_IND_READY, GFP_ATOMIC);
 212                 pn->rx_credits = 1;
 213                 break;
 214         case PN_MULTI_CREDIT_FLOW_CONTROL:
 215                 if ((pn->rx_credits + CREDITS_THR) > CREDITS_MAX)
 216                         break;
 217                 if (pipe_snd_status(sk, PN_PEP_IND_ID_MCFC_GRANT_CREDITS,
 218                                         CREDITS_MAX - pn->rx_credits,
 219                                         GFP_ATOMIC) == 0)
 220                         pn->rx_credits = CREDITS_MAX;
 221                 break;
 222         }
 223 }
 224
 225 static int pipe_rcv_status(struct sock *sk, struct sk_buff *skb)
 226 {
 227         struct pep_sock *pn = pep_sk(sk);
 228         struct pnpipehdr *hdr = pnp_hdr(skb);
 229         int wake = 0;
 230
 231         if (!pskb_may_pull(skb, sizeof(*hdr) + 4))
 232                 return -EINVAL;
 233
 234         if (hdr->data[0] != PN_PEP_TYPE_COMMON) {
 235                 LIMIT_NETDEBUG(KERN_DEBUG"Phonet unknown PEP type: %u\n",
 236                                 (unsigned)hdr->data[0]);
 237                 return -EOPNOTSUPP;
 238         }
 239
 240         switch (hdr->data[1]) {
 241         case PN_PEP_IND_FLOW_CONTROL:
 242                 switch (pn->tx_fc) {
 243                 case PN_LEGACY_FLOW_CONTROL:
 244                         switch (hdr->data[4]) {
 245                         case PEP_IND_BUSY:
 246                                 atomic_set(&pn->tx_credits, 0);
 247                                 break;
 248                         case PEP_IND_READY:
 249                                 atomic_set(&pn->tx_credits, wake = 1);
 250                                 break;
 251                         }
 252                         break;
 253                 case PN_ONE_CREDIT_FLOW_CONTROL:
 254                         if (hdr->data[4] == PEP_IND_READY)
 255                                 atomic_set(&pn->tx_credits, wake = 1);
 256                         break;
 257                 }
 258                 break;
 259
 260         case PN_PEP_IND_ID_MCFC_GRANT_CREDITS:
 261                 if (pn->tx_fc != PN_MULTI_CREDIT_FLOW_CONTROL)
 262                         break;
 263                 atomic_add(wake = hdr->data[4], &pn->tx_credits);
 264                 break;
 265
 266         default:
 267                 LIMIT_NETDEBUG(KERN_DEBUG"Phonet unknown PEP indication: %u\n",
 268                                 (unsigned)hdr->data[1]);
 269                 return -EOPNOTSUPP;
 270         }
 271         if (wake)
 272                 sk->sk_write_space(sk);
 273         return 0;
 274 }
 275
 276 static int pipe_rcv_created(struct sock *sk, struct sk_buff *skb)
 277 {
 278         struct pep_sock *pn = pep_sk(sk);
 279         struct pnpipehdr *hdr = pnp_hdr(skb);
 280         u8 n_sb = hdr->data[0];
 281
 282         pn->rx_fc = pn->tx_fc = PN_LEGACY_FLOW_CONTROL;
 283         __skb_pull(skb, sizeof(*hdr));
 284         while (n_sb > 0) {
 285                 u8 type, buf[2], len = sizeof(buf);
 286                 u8 *data = pep_get_sb(skb, &type, &len, buf);
 287
 288                 if (data == NULL)
 289                         return -EINVAL;
 290                 switch (type) {
 291                 case PN_PIPE_SB_NEGOTIATED_FC:
 292                         if (len < 2 || (data[0] | data[1]) > 3)
 293                                 break;
 294                         pn->tx_fc = data[0] & 3;
 295                         pn->rx_fc = data[1] & 3;
 296                         break;
 297                 }
 298                 n_sb--;
 299         }
 300         return 0;
 301 }
 302
 303 /* Queue an skb to a connected sock.
 304  * Socket lock must be held. */
 305 static int pipe_do_rcv(struct sock *sk, struct sk_buff *skb)
 306 {
 307         struct pep_sock *pn = pep_sk(sk);
 308         struct pnpipehdr *hdr = pnp_hdr(skb);
 309         struct sk_buff_head *queue;
 310         int err = 0;
 311
 312         BUG_ON(sk->sk_state == TCP_CLOSE_WAIT);
 313
 314         switch (hdr->message_id) {
 315         case PNS_PEP_CONNECT_REQ:
 316                 pep_reject_conn(sk, skb, PN_PIPE_ERR_PEP_IN_USE);
 317                 break;
 318
 319         case PNS_PEP_DISCONNECT_REQ:
 320                 pep_reply(sk, skb, PN_PIPE_NO_ERROR, NULL, 0, GFP_ATOMIC);
 321                 sk->sk_state = TCP_CLOSE_WAIT;
 322                 if (!sock_flag(sk, SOCK_DEAD))
 323                         sk->sk_state_change(sk);
 324                 break;
 325
 326         case PNS_PEP_ENABLE_REQ:
 327                 /* Wait for PNS_PIPE_(ENABLED|REDIRECTED)_IND */
 328                 pep_reply(sk, skb, PN_PIPE_NO_ERROR, NULL, 0, GFP_ATOMIC);
 329                 break;
 330
 331         case PNS_PEP_RESET_REQ:
 332                 switch (hdr->state_after_reset) {
 333                 case PN_PIPE_DISABLE:
 334                         pn->init_enable = 0;
 335                         break;
 336                 case PN_PIPE_ENABLE:
 337                         pn->init_enable = 1;
 338                         break;
 339                 default: /* not allowed to send an error here!? */
 340                         err = -EINVAL;
 341                         goto out;
 342                 }
 343                 /* fall through */
 344         case PNS_PEP_DISABLE_REQ:
 345                 atomic_set(&pn->tx_credits, 0);
 346                 pep_reply(sk, skb, PN_PIPE_NO_ERROR, NULL, 0, GFP_ATOMIC);
 347                 break;
 348
 349         case PNS_PEP_CTRL_REQ:
 350                 if (skb_queue_len(&pn->ctrlreq_queue) >= PNPIPE_CTRLREQ_MAX) {
 351                         atomic_inc(&sk->sk_drops);
 352                         break;
 353                 }
 354                 __skb_pull(skb, 4);
 355                 queue = &pn->ctrlreq_queue;
 356                 goto queue;
 357
 358         case PNS_PIPE_ALIGNED_DATA:
 359                 __skb_pull(skb, 1);
 360                 /* fall through */
 361         case PNS_PIPE_DATA:
 362                 __skb_pull(skb, 3); /* Pipe data header */
 363                 if (!pn_flow_safe(pn->rx_fc)) {
 364                         err = sock_queue_rcv_skb(sk, skb);
 365                         if (!err)
 366                                 return 0;
 367                         break;
 368                 }
 369
 370                 if (pn->rx_credits == 0) {
 371                         atomic_inc(&sk->sk_drops);
 372                         err = -ENOBUFS;
 373                         break;
 374                 }
 375                 pn->rx_credits--;
 376                 queue = &sk->sk_receive_queue;
 377                 goto queue;
 378
 379         case PNS_PEP_STATUS_IND:
 380                 pipe_rcv_status(sk, skb);
 381                 break;
 382
 383         case PNS_PIPE_REDIRECTED_IND:
 384                 err = pipe_rcv_created(sk, skb);
 385                 break;
 386
 387         case PNS_PIPE_CREATED_IND:
 388                 err = pipe_rcv_created(sk, skb);
 389                 if (err)
 390                         break;
 391                 /* fall through */
 392         case PNS_PIPE_RESET_IND:
 393                 if (!pn->init_enable)
 394                         break;
 395                 /* fall through */
 396         case PNS_PIPE_ENABLED_IND:
 397                 if (!pn_flow_safe(pn->tx_fc)) {
 398                         atomic_set(&pn->tx_credits, 1);
 399                         sk->sk_write_space(sk);
 400                 }
 401                 if (sk->sk_state == TCP_ESTABLISHED)
 402                         break; /* Nothing to do */
 403                 sk->sk_state = TCP_ESTABLISHED;
 404                 pipe_grant_credits(sk);
 405                 break;
 406
 407         case PNS_PIPE_DISABLED_IND:
 408                 sk->sk_state = TCP_SYN_RECV;
 409                 pn->rx_credits = 0;
 410                 break;
 411
 412         default:
 413                 LIMIT_NETDEBUG(KERN_DEBUG"Phonet unknown PEP message: %u\n",
 414                                 hdr->message_id);
 415                 err = -EINVAL;
 416         }
 417 out:
 418         kfree_skb(skb);
 419         return err;
 420
 421 queue:
 422         skb->dev = NULL;
 423         skb_set_owner_r(skb, sk);
 424         err = skb->len;
 425         skb_queue_tail(queue, skb);
 426         if (!sock_flag(sk, SOCK_DEAD))
 427                 sk->sk_data_ready(sk, err);
 428         return 0;
 429 }
 430
 431 /* Destroy connected sock. */
 432 static void pipe_destruct(struct sock *sk)
 433 {
 434         struct pep_sock *pn = pep_sk(sk);
 435
 436         skb_queue_purge(&sk->sk_receive_queue);
 437         skb_queue_purge(&pn->ctrlreq_queue);
 438 }
 439
 440 static int pep_connreq_rcv(struct sock *sk, struct sk_buff *skb)
 441 {
 442         struct sock *newsk;
 443         struct pep_sock *newpn, *pn = pep_sk(sk);
 444         struct pnpipehdr *hdr;
 445         struct sockaddr_pn dst;
 446         u16 peer_type;
 447         u8 pipe_handle, enabled, n_sb;
 448         u8 aligned = 0;
 449
 450         if (!pskb_pull(skb, sizeof(*hdr) + 4))
 451                 return -EINVAL;
 452
 453         hdr = pnp_hdr(skb);
 454         pipe_handle = hdr->pipe_handle;
 455         switch (hdr->state_after_connect) {
 456         case PN_PIPE_DISABLE:
 457                 enabled = 0;
 458                 break;
 459         case PN_PIPE_ENABLE:
 460                 enabled = 1;
 461                 break;
 462         default:
 463                 pep_reject_conn(sk, skb, PN_PIPE_ERR_INVALID_PARAM);
 464                 return -EINVAL;
 465         }
 466         peer_type = hdr->other_pep_type << 8;
 467
 468         if (unlikely(sk->sk_state != TCP_LISTEN) || sk_acceptq_is_full(sk)) {
 469                 pep_reject_conn(sk, skb, PN_PIPE_ERR_PEP_IN_USE);
 470                 return -ENOBUFS;
 471         }
 472
 473         /* Parse sub-blocks (options) */
 474         n_sb = hdr->data[4];
 475         while (n_sb > 0) {
 476                 u8 type, buf[1], len = sizeof(buf);
 477                 const u8 *data = pep_get_sb(skb, &type, &len, buf);
 478
 479                 if (data == NULL)
 480                         return -EINVAL;
 481                 switch (type) {
 482                 case PN_PIPE_SB_CONNECT_REQ_PEP_SUB_TYPE:
 483                         if (len < 1)
 484                                 return -EINVAL;
 485                         peer_type = (peer_type & 0xff00) | data[0];
 486                         break;
 487                 case PN_PIPE_SB_ALIGNED_DATA:
 488                         aligned = data[0] != 0;
 489                         break;
 490                 }
 491                 n_sb--;
 492         }
 493
 494         skb = skb_clone(skb, GFP_ATOMIC);
 495         if (!skb)
 496                 return -ENOMEM;
 497
 498         /* Create a new to-be-accepted sock */
 499         newsk = sk_alloc(sock_net(sk), PF_PHONET, GFP_ATOMIC, sk->sk_prot);
 500         if (!newsk) {
 501                 kfree_skb(skb);
 502                 return -ENOMEM;
 503         }
 504         sock_init_data(NULL, newsk);
 505         newsk->sk_state = TCP_SYN_RECV;
 506         newsk->sk_backlog_rcv = pipe_do_rcv;
 507         newsk->sk_protocol = sk->sk_protocol;
 508         newsk->sk_destruct = pipe_destruct;
 509
 510         newpn = pep_sk(newsk);
 511         pn_skb_get_dst_sockaddr(skb, &dst);
 512         newpn->pn_sk.sobject = pn_sockaddr_get_object(&dst);
 513         newpn->pn_sk.resource = pn->pn_sk.resource;
 514         skb_queue_head_init(&newpn->ctrlreq_queue);
 515         newpn->pipe_handle = pipe_handle;
 516         atomic_set(&newpn->tx_credits, 0);
 517         newpn->peer_type = peer_type;
 518         newpn->rx_credits = 0;
 519         newpn->rx_fc = newpn->tx_fc = PN_LEGACY_FLOW_CONTROL;
 520         newpn->init_enable = enabled;
 521         newpn->aligned = aligned;
 522
 523         BUG_ON(!skb_queue_empty(&newsk->sk_receive_queue));
 524         skb_queue_head(&newsk->sk_receive_queue, skb);
 525         if (!sock_flag(sk, SOCK_DEAD))
 526                 sk->sk_data_ready(sk, 0);
 527
 528         sk_acceptq_added(sk);
 529         sk_add_node(newsk, &pn->ackq);
 530         return 0;
 531 }
 532
 533 /* Listening sock must be locked */
 534 static struct sock *pep_find_pipe(const struct hlist_head *hlist,
 535                                         const struct sockaddr_pn *dst,
 536                                         u8 pipe_handle)
 537 {
 538         struct hlist_node *node;
 539         struct sock *sknode;
 540         u16 dobj = pn_sockaddr_get_object(dst);
 541
 542         sk_for_each(sknode, node, hlist) {
 543                 struct pep_sock *pnnode = pep_sk(sknode);
 544
 545                 /* Ports match, but addresses might not: */
 546                 if (pnnode->pn_sk.sobject != dobj)
 547                         continue;
 548                 if (pnnode->pipe_handle != pipe_handle)
 549                         continue;
 550                 if (sknode->sk_state == TCP_CLOSE_WAIT)
 551                         continue;
 552
 553                 sock_hold(sknode);
 554                 return sknode;
 555         }
 556         return NULL;
 557 }
 558
 559 /*
 560  * Deliver an skb to a listening sock.
 561  * Socket lock must be held.
 562  * We then queue the skb to the right connected sock (if any).
 563  */
 564 static int pep_do_rcv(struct sock *sk, struct sk_buff *skb)
 565 {
 566         struct pep_sock *pn = pep_sk(sk);
 567         struct sock *sknode;
 568         struct pnpipehdr *hdr;
 569         struct sockaddr_pn dst;
 570         int err = NET_RX_SUCCESS;
 571         u8 pipe_handle;
 572
 573         if (!pskb_may_pull(skb, sizeof(*hdr)))
 574                 goto drop;
 575
 576         hdr = pnp_hdr(skb);
 577         pipe_handle = hdr->pipe_handle;
 578         if (pipe_handle == PN_PIPE_INVALID_HANDLE)
 579                 goto drop;
 580
 581         pn_skb_get_dst_sockaddr(skb, &dst);
 582
 583         /* Look for an existing pipe handle */
 584         sknode = pep_find_pipe(&pn->hlist, &dst, pipe_handle);
 585         if (sknode)
 586                 return sk_receive_skb(sknode, skb, 1);
 587
 588         /* Look for a pipe handle pending accept */
 589         sknode = pep_find_pipe(&pn->ackq, &dst, pipe_handle);
 590         if (sknode) {
 591                 sock_put(sknode);
 592                 if (net_ratelimit())
 593                         printk(KERN_WARNING"Phonet unconnected PEP ignored");
 594                 err = NET_RX_DROP;
 595                 goto drop;
 596         }
 597
 598         switch (hdr->message_id) {
 599         case PNS_PEP_CONNECT_REQ:
 600                 err = pep_connreq_rcv(sk, skb);
 601                 break;
 602
 603         case PNS_PEP_DISCONNECT_REQ:
 604                 pep_reply(sk, skb, PN_PIPE_NO_ERROR, NULL, 0, GFP_ATOMIC);
 605                 break;
 606
 607         case PNS_PEP_CTRL_REQ:
 608                 pep_ctrlreq_error(sk, skb, PN_PIPE_INVALID_HANDLE, GFP_ATOMIC);
 609                 break;
 610
 611         case PNS_PEP_RESET_REQ:
 612         case PNS_PEP_ENABLE_REQ:
 613         case PNS_PEP_DISABLE_REQ:
 614                 /* invalid handle is not even allowed here! */
 615         default:
 616                 err = NET_RX_DROP;
 617         }
 618 drop:
 619         kfree_skb(skb);
 620         return err;
 621 }
 622
 623 /* associated socket ceases to exist */
 624 static void pep_sock_close(struct sock *sk, long timeout)
 625 {
 626         struct pep_sock *pn = pep_sk(sk);
 627         int ifindex = 0;
 628
 629         sk_common_release(sk);
 630
 631         lock_sock(sk);
 632         if (sk->sk_state == TCP_LISTEN) {
 633                 /* Destroy the listen queue */
 634                 struct sock *sknode;
 635                 struct hlist_node *p, *n;
 636
 637                 sk_for_each_safe(sknode, p, n, &pn->ackq)
 638                         sk_del_node_init(sknode);
 639                 sk->sk_state = TCP_CLOSE;
 640         }
 641         ifindex = pn->ifindex;
 642         pn->ifindex = 0;
 643         release_sock(sk);
 644
 645         if (ifindex)
 646                 gprs_detach(sk);
 647 }
 648
 649 static int pep_wait_connreq(struct sock *sk, int noblock)
 650 {
 651         struct task_struct *tsk = current;
 652         struct pep_sock *pn = pep_sk(sk);
 653         long timeo = sock_rcvtimeo(sk, noblock);
 654
 655         for (;;) {
 656                 DEFINE_WAIT(wait);
 657
 658                 if (sk->sk_state != TCP_LISTEN)
 659                         return -EINVAL;
 660                 if (!hlist_empty(&pn->ackq))
 661                         break;
 662                 if (!timeo)
 663                         return -EWOULDBLOCK;
 664                 if (signal_pending(tsk))
 665                         return sock_intr_errno(timeo);
 666
 667                 prepare_to_wait_exclusive(sk_sleep(sk), &wait,
 668                                                 TASK_INTERRUPTIBLE);
 669                 release_sock(sk);
 670                 timeo = schedule_timeout(timeo);
 671                 lock_sock(sk);
 672                 finish_wait(sk_sleep(sk), &wait);
 673         }
 674
 675         return 0;
 676 }
 677
 678 static struct sock *pep_sock_accept(struct sock *sk, int flags, int *errp)
 679 {
 680         struct pep_sock *pn = pep_sk(sk);
 681         struct sock *newsk = NULL;
 682         struct sk_buff *oskb;
 683         int err;
 684
 685         lock_sock(sk);
 686         err = pep_wait_connreq(sk, flags & O_NONBLOCK);
 687         if (err)
 688                 goto out;
 689
 690         newsk = __sk_head(&pn->ackq);
 691
 692         oskb = skb_dequeue(&newsk->sk_receive_queue);
 693         err = pep_accept_conn(newsk, oskb);
 694         if (err) {
 695                 skb_queue_head(&newsk->sk_receive_queue, oskb);
 696                 newsk = NULL;
 697                 goto out;
 698         }
 699
 700         sock_hold(sk);
 701         pep_sk(newsk)->listener = sk;
 702
 703         sock_hold(newsk);
 704         sk_del_node_init(newsk);
 705         sk_acceptq_removed(sk);
 706         sk_add_node(newsk, &pn->hlist);
 707         __sock_put(newsk);
 708
 709 out:
 710         release_sock(sk);
 711         *errp = err;
 712         return newsk;
 713 }
 714
 715 static int pep_ioctl(struct sock *sk, int cmd, unsigned long arg)
 716 {
 717         struct pep_sock *pn = pep_sk(sk);
 718         int answ;
 719
 720         switch (cmd) {
 721         case SIOCINQ:
 722                 if (sk->sk_state == TCP_LISTEN)
 723                         return -EINVAL;
 724
 725                 lock_sock(sk);
 726                 if (sock_flag(sk, SOCK_URGINLINE) &&
 727                     !skb_queue_empty(&pn->ctrlreq_queue))
 728                         answ = skb_peek(&pn->ctrlreq_queue)->len;
 729                 else if (!skb_queue_empty(&sk->sk_receive_queue))
 730                         answ = skb_peek(&sk->sk_receive_queue)->len;
 731                 else
 732                         answ = 0;
 733                 release_sock(sk);
 734                 return put_user(answ, (int __user *)arg);
 735         }
 736
 737         return -ENOIOCTLCMD;
 738 }
 739
 740 static int pep_init(struct sock *sk)
 741 {
 742         struct pep_sock *pn = pep_sk(sk);
 743
 744         INIT_HLIST_HEAD(&pn->ackq);
 745         INIT_HLIST_HEAD(&pn->hlist);
 746         skb_queue_head_init(&pn->ctrlreq_queue);
 747         pn->pipe_handle = PN_PIPE_INVALID_HANDLE;
 748         return 0;
 749 }
 750
 751 static int pep_setsockopt(struct sock *sk, int level, int optname,
 752                                 char __user *optval, unsigned int optlen)
 753 {
 754         struct pep_sock *pn = pep_sk(sk);
 755         int val = 0, err = 0;
 756
 757         if (level != SOL_PNPIPE)
 758                 return -ENOPROTOOPT;
 759         if (optlen >= sizeof(int)) {
 760                 if (get_user(val, (int __user *) optval))
 761                         return -EFAULT;
 762         }
 763
 764         lock_sock(sk);
 765         switch (optname) {
 766         case PNPIPE_ENCAP:
 767                 if (val && val != PNPIPE_ENCAP_IP) {
 768                         err = -EINVAL;
 769                         break;
 770                 }
 771                 if (!pn->ifindex == !val)
 772                         break; /* Nothing to do! */
 773                 if (!capable(CAP_NET_ADMIN)) {
 774                         err = -EPERM;
 775                         break;
 776                 }
 777                 if (val) {
 778                         release_sock(sk);
 779                         err = gprs_attach(sk);
 780                         if (err > 0) {
 781                                 pn->ifindex = err;
 782                                 err = 0;
 783                         }
 784                 } else {
 785                         pn->ifindex = 0;
 786                         release_sock(sk);
 787                         gprs_detach(sk);
 788                         err = 0;
 789                 }
 790                 goto out_norel;
 791         default:
 792                 err = -ENOPROTOOPT;
 793         }
 794         release_sock(sk);
 795
 796 out_norel:
 797         return err;
 798 }
 799
 800 static int pep_getsockopt(struct sock *sk, int level, int optname,
 801                                 char __user *optval, int __user *optlen)
 802 {
 803         struct pep_sock *pn = pep_sk(sk);
 804         int len, val;
 805
 806         if (level != SOL_PNPIPE)
 807                 return -ENOPROTOOPT;
 808         if (get_user(len, optlen))
 809                 return -EFAULT;
 810
 811         switch (optname) {
 812         case PNPIPE_ENCAP:
 813                 val = pn->ifindex ? PNPIPE_ENCAP_IP : PNPIPE_ENCAP_NONE;
 814                 break;
 815         case PNPIPE_IFINDEX:
 816                 val = pn->ifindex;
 817                 break;
 818         default:
 819                 return -ENOPROTOOPT;
 820         }
 821
 822         len = min_t(unsigned int, sizeof(int), len);
 823         if (put_user(len, optlen))
 824                 return -EFAULT;
 825         if (put_user(val, (int __user *) optval))
 826                 return -EFAULT;
 827         return 0;
 828 }
 829
 830 static int pipe_skb_send(struct sock *sk, struct sk_buff *skb)
 831 {
 832         struct pep_sock *pn = pep_sk(sk);
 833         struct pnpipehdr *ph;
 834
 835         if (pn_flow_safe(pn->tx_fc) &&
 836             !atomic_add_unless(&pn->tx_credits, -1, 0)) {
 837                 kfree_skb(skb);
 838                 return -ENOBUFS;
 839         }
 840
 841         skb_push(skb, 3 + pn->aligned);
 842         skb_reset_transport_header(skb);
 843         ph = pnp_hdr(skb);
 844         ph->utid = 0;
 845         if (pn->aligned) {
 846                 ph->message_id = PNS_PIPE_ALIGNED_DATA;
 847                 ph->data[0] = 0; /* padding */
 848         } else
 849                 ph->message_id = PNS_PIPE_DATA;
 850         ph->pipe_handle = pn->pipe_handle;
 851
 852         return pn_skb_send(sk, skb, &pipe_srv);
 853 }
 854
 855 static int pep_sendmsg(struct kiocb *iocb, struct sock *sk,
 856                         struct msghdr *msg, size_t len)
 857 {
 858         struct pep_sock *pn = pep_sk(sk);
 859         struct sk_buff *skb;
 860         long timeo;
 861         int flags = msg->msg_flags;
 862         int err, done;
 863
 864         if ((msg->msg_flags & ~(MSG_DONTWAIT|MSG_EOR|MSG_NOSIGNAL|
 865                                 MSG_CMSG_COMPAT)) ||
 866                         !(msg->msg_flags & MSG_EOR))
 867                 return -EOPNOTSUPP;
 868
 869         skb = sock_alloc_send_skb(sk, MAX_PNPIPE_HEADER + len,
 870                                         flags & MSG_DONTWAIT, &err);
 871         if (!skb)
 872                 return -ENOBUFS;
 873
 874         skb_reserve(skb, MAX_PHONET_HEADER + 3);
 875         err = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len);
 876         if (err < 0)
 877                 goto outfree;
 878
 879         lock_sock(sk);
 880         timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT);
 881         if ((1 << sk->sk_state) & (TCPF_LISTEN|TCPF_CLOSE)) {
 882                 err = -ENOTCONN;
 883                 goto out;
 884         }
 885         if (sk->sk_state != TCP_ESTABLISHED) {
 886                 /* Wait until the pipe gets to enabled state */
 887 disabled:
 888                 err = sk_stream_wait_connect(sk, &timeo);
 889                 if (err)
 890                         goto out;
 891
 892                 if (sk->sk_state == TCP_CLOSE_WAIT) {
 893                         err = -ECONNRESET;
 894                         goto out;
 895                 }
 896         }
 897         BUG_ON(sk->sk_state != TCP_ESTABLISHED);
 898
 899         /* Wait until flow control allows TX */
 900         done = atomic_read(&pn->tx_credits);
 901         while (!done) {
 902                 DEFINE_WAIT(wait);
 903
 904                 if (!timeo) {
 905                         err = -EAGAIN;
 906                         goto out;
 907                 }
 908                 if (signal_pending(current)) {
 909                         err = sock_intr_errno(timeo);
 910                         goto out;
 911                 }
 912
 913                 prepare_to_wait(sk_sleep(sk), &wait,
 914                                 TASK_INTERRUPTIBLE);
 915                 done = sk_wait_event(sk, &timeo, atomic_read(&pn->tx_credits));
 916                 finish_wait(sk_sleep(sk), &wait);
 917
 918                 if (sk->sk_state != TCP_ESTABLISHED)
 919                         goto disabled;
 920         }
 921
 922         err = pipe_skb_send(sk, skb);
 923         if (err >= 0)
 924                 err = len; /* success! */
 925         skb = NULL;
 926 out:
 927         release_sock(sk);
 928 outfree:
 929         kfree_skb(skb);
 930         return err;
 931 }
 932
 933 int pep_writeable(struct sock *sk)
 934 {
 935         struct pep_sock *pn = pep_sk(sk);
 936
 937         return atomic_read(&pn->tx_credits);
 938 }
 939
 940 int pep_write(struct sock *sk, struct sk_buff *skb)
 941 {
 942         struct sk_buff *rskb, *fs;
 943         int flen = 0;
 944
 945         if (pep_sk(sk)->aligned)
 946                 return pipe_skb_send(sk, skb);
 947
 948         rskb = alloc_skb(MAX_PNPIPE_HEADER, GFP_ATOMIC);
 949         if (!rskb) {
 950                 kfree_skb(skb);
 951                 return -ENOMEM;
 952         }
 953         skb_shinfo(rskb)->frag_list = skb;
 954         rskb->len += skb->len;
 955         rskb->data_len += rskb->len;
 956         rskb->truesize += rskb->len;
 957
 958         /* Avoid nested fragments */
 959         skb_walk_frags(skb, fs)
 960                 flen += fs->len;
 961         skb->next = skb_shinfo(skb)->frag_list;
 962         skb_frag_list_init(skb);
 963         skb->len -= flen;
 964         skb->data_len -= flen;
 965         skb->truesize -= flen;
 966
 967         skb_reserve(rskb, MAX_PHONET_HEADER + 3);
 968         return pipe_skb_send(sk, rskb);
 969 }
 970
 971 struct sk_buff *pep_read(struct sock *sk)
 972 {
 973         struct sk_buff *skb = skb_dequeue(&sk->sk_receive_queue);
 974
 975         if (sk->sk_state == TCP_ESTABLISHED)
 976                 pipe_grant_credits(sk);
 977         return skb;
 978 }
 979
 980 static int pep_recvmsg(struct kiocb *iocb, struct sock *sk,
 981                         struct msghdr *msg, size_t len, int noblock,
 982                         int flags, int *addr_len)
 983 {
 984         struct sk_buff *skb;
 985         int err;
 986
 987         if (flags & ~(MSG_OOB|MSG_PEEK|MSG_TRUNC|MSG_DONTWAIT|MSG_WAITALL|
 988                         MSG_NOSIGNAL|MSG_CMSG_COMPAT))
 989                 return -EOPNOTSUPP;
 990
 991         if (unlikely(1 << sk->sk_state & (TCPF_LISTEN | TCPF_CLOSE)))
 992                 return -ENOTCONN;
 993
 994         if ((flags & MSG_OOB) || sock_flag(sk, SOCK_URGINLINE)) {
 995                 /* Dequeue and acknowledge control request */
 996                 struct pep_sock *pn = pep_sk(sk);
 997
 998                 if (flags & MSG_PEEK)
 999                         return -EOPNOTSUPP;
1000                 skb = skb_dequeue(&pn->ctrlreq_queue);
1001                 if (skb) {
1002                         pep_ctrlreq_error(sk, skb, PN_PIPE_NO_ERROR,
1003                                                 GFP_KERNEL);
1004                         msg->msg_flags |= MSG_OOB;
1005                         goto copy;
1006                 }
1007                 if (flags & MSG_OOB)
1008                         return -EINVAL;
1009         }
1010
1011         skb = skb_recv_datagram(sk, flags, noblock, &err);
1012         lock_sock(sk);
1013         if (skb == NULL) {
1014                 if (err == -ENOTCONN && sk->sk_state == TCP_CLOSE_WAIT)
1015                         err = -ECONNRESET;
1016                 release_sock(sk);
1017                 return err;
1018         }
1019
1020         if (sk->sk_state == TCP_ESTABLISHED)
1021                 pipe_grant_credits(sk);
1022         release_sock(sk);
1023 copy:
1024         msg->msg_flags |= MSG_EOR;
1025         if (skb->len > len)
1026                 msg->msg_flags |= MSG_TRUNC;
1027         else
1028                 len = skb->len;
1029
1030         err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, len);
1031         if (!err)
1032                 err = (flags & MSG_TRUNC) ? skb->len : len;
1033
1034         skb_free_datagram(sk, skb);
1035         return err;
1036 }
1037
1038 static void pep_sock_unhash(struct sock *sk)
1039 {
1040         struct pep_sock *pn = pep_sk(sk);
1041         struct sock *skparent = NULL;
1042
1043         lock_sock(sk);
1044         if ((1 << sk->sk_state) & ~(TCPF_CLOSE|TCPF_LISTEN)) {
1045                 skparent = pn->listener;
1046                 sk_del_node_init(sk);
1047                 release_sock(sk);
1048
1049                 sk = skparent;
1050                 pn = pep_sk(skparent);
1051                 lock_sock(sk);
1052         }
1053         /* Unhash a listening sock only when it is closed
1054          * and all of its active connected pipes are closed. */
1055         if (hlist_empty(&pn->hlist))
1056                 pn_sock_unhash(&pn->pn_sk.sk);
1057         release_sock(sk);
1058
1059         if (skparent)
1060                 sock_put(skparent);
1061 }
1062
1063 static struct proto pep_proto = {
1064         .close          = pep_sock_close,
1065         .accept         = pep_sock_accept,
1066         .ioctl          = pep_ioctl,
1067         .init           = pep_init,
1068         .setsockopt     = pep_setsockopt,
1069         .getsockopt     = pep_getsockopt,
1070         .sendmsg        = pep_sendmsg,
1071         .recvmsg        = pep_recvmsg,
1072         .backlog_rcv    = pep_do_rcv,
1073         .hash           = pn_sock_hash,
1074         .unhash         = pep_sock_unhash,
1075         .get_port       = pn_sock_get_port,
1076         .obj_size       = sizeof(struct pep_sock),
1077         .owner          = THIS_MODULE,
1078         .name           = "PNPIPE",
1079 };
1080
1081 static struct phonet_protocol pep_pn_proto = {
1082         .ops            = &phonet_stream_ops,
1083         .prot           = &pep_proto,
1084         .sock_type      = SOCK_SEQPACKET,
1085 };
1086
1087 static int __init pep_register(void)
1088 {
1089         return phonet_proto_register(PN_PROTO_PIPE, &pep_pn_proto);
1090 }
1091
1092 static void __exit pep_unregister(void)
1093 {
1094         phonet_proto_unregister(PN_PROTO_PIPE, &pep_pn_proto);
1095 }
1096
1097 module_init(pep_register);
1098 module_exit(pep_unregister);
1099 MODULE_AUTHOR("Remi Denis-Courmont, Nokia");
1100 MODULE_DESCRIPTION("Phonet pipe protocol");
1101 MODULE_LICENSE("GPL");
1102 MODULE_ALIAS_NET_PF_PROTO(PF_PHONET, PN_PROTO_PIPE);