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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/socket.h>
  27 #include <net/sock.h>
  28 #include <net/tcp_states.h>
  29 #include <asm/ioctls.h>
  30
  31 #include <linux/phonet.h>
  32 #include <net/phonet/phonet.h>
  33 #include <net/phonet/pep.h>
  34
  35 /* sk_state values:
  36  * TCP_CLOSE            sock not in use yet
  37  * TCP_CLOSE_WAIT       disconnected pipe
  38  * TCP_LISTEN           listening pipe endpoint
  39  * TCP_SYN_RECV         connected pipe in disabled state
  40  * TCP_ESTABLISHED      connected pipe in enabled state
  41  *
  42  * pep_sock locking:
  43  *  - sk_state, ackq, hlist: sock lock needed
  44  *  - listener: read only
  45  *  - pipe_handle: read only
  46  */
  47
  48 #define CREDITS_MAX     10
  49 #define CREDITS_THR     7
  50
  51 static const struct sockaddr_pn pipe_srv = {
  52         .spn_family = AF_PHONET,
  53         .spn_resource = 0xD9, /* pipe service */
  54 };
  55
  56 #define pep_sb_size(s) (((s) + 5) & ~3) /* 2-bytes head, 32-bits aligned */
  57
  58 /* Get the next TLV sub-block. */
  59 static unsigned char *pep_get_sb(struct sk_buff *skb, u8 *ptype, u8 *plen,
  60                                         void *buf)
  61 {
  62         void *data = NULL;
  63         struct {
  64                 u8 sb_type;
  65                 u8 sb_len;
  66         } *ph, h;
  67         int buflen = *plen;
  68
  69         ph = skb_header_pointer(skb, 0, 2, &h);
  70         if (ph == NULL || ph->sb_len < 2 || !pskb_may_pull(skb, ph->sb_len))
  71                 return NULL;
  72         ph->sb_len -= 2;
  73         *ptype = ph->sb_type;
  74         *plen = ph->sb_len;
  75
  76         if (buflen > ph->sb_len)
  77                 buflen = ph->sb_len;
  78         data = skb_header_pointer(skb, 2, buflen, buf);
  79         __skb_pull(skb, 2 + ph->sb_len);
  80         return data;
  81 }
  82
  83 static int pep_reply(struct sock *sk, struct sk_buff *oskb,
  84                         u8 code, const void *data, int len, gfp_t priority)
  85 {
  86         const struct pnpipehdr *oph = pnp_hdr(oskb);
  87         struct pnpipehdr *ph;
  88         struct sk_buff *skb;
  89
  90         skb = alloc_skb(MAX_PNPIPE_HEADER + len, priority);
  91         if (!skb)
  92                 return -ENOMEM;
  93         skb_set_owner_w(skb, sk);
  94
  95         skb_reserve(skb, MAX_PNPIPE_HEADER);
  96         __skb_put(skb, len);
  97         skb_copy_to_linear_data(skb, data, len);
  98         __skb_push(skb, sizeof(*ph));
  99         skb_reset_transport_header(skb);
 100         ph = pnp_hdr(skb);
 101         ph->utid = oph->utid;
 102         ph->message_id = oph->message_id + 1; /* REQ -> RESP */
 103         ph->pipe_handle = oph->pipe_handle;
 104         ph->error_code = code;
 105
 106         return pn_skb_send(sk, skb, &pipe_srv);
 107 }
 108
 109 #define PAD 0x00
 110 static int pep_accept_conn(struct sock *sk, struct sk_buff *skb)
 111 {
 112         static const u8 data[20] = {
 113                 PAD, PAD, PAD, 2 /* sub-blocks */,
 114                 PN_PIPE_SB_REQUIRED_FC_TX, pep_sb_size(5), 3, PAD,
 115                         PN_MULTI_CREDIT_FLOW_CONTROL,
 116                         PN_ONE_CREDIT_FLOW_CONTROL,
 117                         PN_LEGACY_FLOW_CONTROL,
 118                         PAD,
 119                 PN_PIPE_SB_PREFERRED_FC_RX, pep_sb_size(5), 3, PAD,
 120                         PN_MULTI_CREDIT_FLOW_CONTROL,
 121                         PN_ONE_CREDIT_FLOW_CONTROL,
 122                         PN_LEGACY_FLOW_CONTROL,
 123                         PAD,
 124         };
 125
 126         might_sleep();
 127         return pep_reply(sk, skb, PN_PIPE_NO_ERROR, data, sizeof(data),
 128                                 GFP_KERNEL);
 129 }
 130
 131 static int pep_reject_conn(struct sock *sk, struct sk_buff *skb, u8 code)
 132 {
 133         static const u8 data[4] = { PAD, PAD, PAD, 0 /* sub-blocks */ };
 134         WARN_ON(code == PN_PIPE_NO_ERROR);
 135         return pep_reply(sk, skb, code, data, sizeof(data), GFP_ATOMIC);
 136 }
 137
 138 /* Control requests are not sent by the pipe service and have a specific
 139  * message format. */
 140 static int pep_ctrlreq_error(struct sock *sk, struct sk_buff *oskb, u8 code)
 141 {
 142         const struct pnpipehdr *oph = pnp_hdr(oskb);
 143         struct sk_buff *skb;
 144         struct pnpipehdr *ph;
 145         struct sockaddr_pn dst;
 146
 147         skb = alloc_skb(MAX_PNPIPE_HEADER + 4, GFP_ATOMIC);
 148         if (!skb)
 149                 return -ENOMEM;
 150         skb_set_owner_w(skb, sk);
 151
 152         skb_reserve(skb, MAX_PHONET_HEADER);
 153         ph = (struct pnpipehdr *)skb_put(skb, sizeof(*ph) + 4);
 154
 155         ph->utid = oph->utid;
 156         ph->message_id = PNS_PEP_CTRL_RESP;
 157         ph->pipe_handle = oph->pipe_handle;
 158         ph->data[0] = oph->data[1]; /* CTRL id */
 159         ph->data[1] = oph->data[0]; /* PEP type */
 160         ph->data[2] = code; /* error code, at an usual offset */
 161         ph->data[3] = PAD;
 162         ph->data[4] = PAD;
 163
 164         pn_skb_get_src_sockaddr(oskb, &dst);
 165         return pn_skb_send(sk, skb, &dst);
 166 }
 167
 168 static int pipe_snd_status(struct sock *sk, u8 type, u8 status, gfp_t priority)
 169 {
 170         struct pep_sock *pn = pep_sk(sk);
 171         struct pnpipehdr *ph;
 172         struct sk_buff *skb;
 173
 174         skb = alloc_skb(MAX_PNPIPE_HEADER + 4, priority);
 175         if (!skb)
 176                 return -ENOMEM;
 177         skb_set_owner_w(skb, sk);
 178
 179         skb_reserve(skb, MAX_PNPIPE_HEADER + 4);
 180         __skb_push(skb, sizeof(*ph) + 4);
 181         skb_reset_transport_header(skb);
 182         ph = pnp_hdr(skb);
 183         ph->utid = 0;
 184         ph->message_id = PNS_PEP_STATUS_IND;
 185         ph->pipe_handle = pn->pipe_handle;
 186         ph->pep_type = PN_PEP_TYPE_COMMON;
 187         ph->data[1] = type;
 188         ph->data[2] = PAD;
 189         ph->data[3] = PAD;
 190         ph->data[4] = status;
 191
 192         return pn_skb_send(sk, skb, &pipe_srv);
 193 }
 194
 195 /* Send our RX flow control information to the sender.
 196  * Socket must be locked. */
 197 static void pipe_grant_credits(struct sock *sk)
 198 {
 199         struct pep_sock *pn = pep_sk(sk);
 200
 201         BUG_ON(sk->sk_state != TCP_ESTABLISHED);
 202
 203         switch (pn->rx_fc) {
 204         case PN_LEGACY_FLOW_CONTROL: /* TODO */
 205                 break;
 206         case PN_ONE_CREDIT_FLOW_CONTROL:
 207                 pipe_snd_status(sk, PN_PEP_IND_FLOW_CONTROL,
 208                                 PEP_IND_READY, GFP_ATOMIC);
 209                 pn->rx_credits = 1;
 210                 break;
 211         case PN_MULTI_CREDIT_FLOW_CONTROL:
 212                 if ((pn->rx_credits + CREDITS_THR) > CREDITS_MAX)
 213                         break;
 214                 if (pipe_snd_status(sk, PN_PEP_IND_ID_MCFC_GRANT_CREDITS,
 215                                         CREDITS_MAX - pn->rx_credits,
 216                                         GFP_ATOMIC) == 0)
 217                         pn->rx_credits = CREDITS_MAX;
 218                 break;
 219         }
 220 }
 221
 222 static int pipe_rcv_status(struct sock *sk, struct sk_buff *skb)
 223 {
 224         struct pep_sock *pn = pep_sk(sk);
 225         struct pnpipehdr *hdr = pnp_hdr(skb);
 226
 227         if (!pskb_may_pull(skb, sizeof(*hdr) + 4))
 228                 return -EINVAL;
 229
 230         if (hdr->data[0] != PN_PEP_TYPE_COMMON) {
 231                 LIMIT_NETDEBUG(KERN_DEBUG"Phonet unknown PEP type: %u\n",
 232                                 (unsigned)hdr->data[0]);
 233                 return -EOPNOTSUPP;
 234         }
 235
 236         switch (hdr->data[1]) {
 237         case PN_PEP_IND_FLOW_CONTROL:
 238                 switch (pn->tx_fc) {
 239                 case PN_LEGACY_FLOW_CONTROL:
 240                         switch (hdr->data[4]) {
 241                         case PEP_IND_BUSY:
 242                                 pn->tx_credits = 0;
 243                                 break;
 244                         case PEP_IND_READY:
 245                                 pn->tx_credits = 1;
 246                                 break;
 247                         }
 248                         break;
 249                 case PN_ONE_CREDIT_FLOW_CONTROL:
 250                         if (hdr->data[4] == PEP_IND_READY)
 251                                 pn->tx_credits = 1;
 252                         break;
 253                 }
 254                 break;
 255
 256         case PN_PEP_IND_ID_MCFC_GRANT_CREDITS:
 257                 if (pn->tx_fc != PN_MULTI_CREDIT_FLOW_CONTROL)
 258                         break;
 259                 if (pn->tx_credits + hdr->data[4] > 0xff)
 260                         pn->tx_credits = 0xff;
 261                 else
 262                         pn->tx_credits += hdr->data[4];
 263                 break;
 264
 265         default:
 266                 LIMIT_NETDEBUG(KERN_DEBUG"Phonet unknown PEP indication: %u\n",
 267                                 (unsigned)hdr->data[1]);
 268                 return -EOPNOTSUPP;
 269         }
 270         if (pn->tx_credits)
 271                 sk->sk_write_space(sk);
 272         return 0;
 273 }
 274
 275 static int pipe_rcv_created(struct sock *sk, struct sk_buff *skb)
 276 {
 277         struct pep_sock *pn = pep_sk(sk);
 278         struct pnpipehdr *hdr = pnp_hdr(skb);
 279         u8 n_sb = hdr->data[0];
 280
 281         pn->rx_fc = pn->tx_fc = PN_LEGACY_FLOW_CONTROL;
 282         __skb_pull(skb, sizeof(*hdr));
 283         while (n_sb > 0) {
 284                 u8 type, buf[2], len = sizeof(buf);
 285                 u8 *data = pep_get_sb(skb, &type, &len, buf);
 286
 287                 if (data == NULL)
 288                         return -EINVAL;
 289                 switch (type) {
 290                 case PN_PIPE_SB_NEGOTIATED_FC:
 291                         if (len < 2 || (data[0] | data[1]) > 3)
 292                                 break;
 293                         pn->tx_fc = data[0] & 3;
 294                         pn->rx_fc = data[1] & 3;
 295                         break;
 296                 }
 297                 n_sb--;
 298         }
 299         return 0;
 300 }
 301
 302 /* Queue an skb to a connected sock.
 303  * Socket lock must be held. */
 304 static int pipe_do_rcv(struct sock *sk, struct sk_buff *skb)
 305 {
 306         struct pep_sock *pn = pep_sk(sk);
 307         struct pnpipehdr *hdr = pnp_hdr(skb);
 308         int err = 0;
 309
 310         BUG_ON(sk->sk_state == TCP_CLOSE_WAIT);
 311
 312         switch (hdr->message_id) {
 313         case PNS_PEP_CONNECT_REQ:
 314                 pep_reject_conn(sk, skb, PN_PIPE_ERR_PEP_IN_USE);
 315                 break;
 316
 317         case PNS_PEP_DISCONNECT_REQ:
 318                 pep_reply(sk, skb, PN_PIPE_NO_ERROR, NULL, 0, GFP_ATOMIC);
 319                 sk->sk_state = TCP_CLOSE_WAIT;
 320                 if (!sock_flag(sk, SOCK_DEAD))
 321                         sk->sk_state_change(sk);
 322                 break;
 323
 324         case PNS_PEP_ENABLE_REQ:
 325                 /* Wait for PNS_PIPE_(ENABLED|REDIRECTED)_IND */
 326                 pep_reply(sk, skb, PN_PIPE_NO_ERROR, NULL, 0, GFP_ATOMIC);
 327                 break;
 328
 329         case PNS_PEP_RESET_REQ:
 330                 switch (hdr->state_after_reset) {
 331                 case PN_PIPE_DISABLE:
 332                         pn->init_enable = 0;
 333                         break;
 334                 case PN_PIPE_ENABLE:
 335                         pn->init_enable = 1;
 336                         break;
 337                 default: /* not allowed to send an error here!? */
 338                         err = -EINVAL;
 339                         goto out;
 340                 }
 341                 /* fall through */
 342         case PNS_PEP_DISABLE_REQ:
 343                 pn->tx_credits = 0;
 344                 pep_reply(sk, skb, PN_PIPE_NO_ERROR, NULL, 0, GFP_ATOMIC);
 345                 break;
 346
 347         case PNS_PEP_CTRL_REQ:
 348                 /* TODO */
 349                 pep_ctrlreq_error(sk, skb, PN_PIPE_NO_ERROR);
 350                 break;
 351
 352         case PNS_PIPE_DATA:
 353                 __skb_pull(skb, 3); /* Pipe data header */
 354                 if (!pn_flow_safe(pn->rx_fc)) {
 355                         err = sock_queue_rcv_skb(sk, skb);
 356                         if (!err)
 357                                 return 0;
 358                         break;
 359                 }
 360
 361                 if (pn->rx_credits == 0) {
 362                         err = -ENOBUFS;
 363                         break;
 364                 }
 365                 pn->rx_credits--;
 366                 skb->dev = NULL;
 367                 skb_set_owner_r(skb, sk);
 368                 err = skb->len;
 369                 skb_queue_tail(&sk->sk_receive_queue, skb);
 370                 if (!sock_flag(sk, SOCK_DEAD))
 371                         sk->sk_data_ready(sk, err);
 372                 return 0;
 373
 374         case PNS_PEP_STATUS_IND:
 375                 pipe_rcv_status(sk, skb);
 376                 break;
 377
 378         case PNS_PIPE_REDIRECTED_IND:
 379                 err = pipe_rcv_created(sk, skb);
 380                 break;
 381
 382         case PNS_PIPE_CREATED_IND:
 383                 err = pipe_rcv_created(sk, skb);
 384                 if (err)
 385                         break;
 386                 /* fall through */
 387         case PNS_PIPE_RESET_IND:
 388                 if (!pn->init_enable)
 389                         break;
 390                 /* fall through */
 391         case PNS_PIPE_ENABLED_IND:
 392                 if (!pn_flow_safe(pn->tx_fc)) {
 393                         pn->tx_credits = 1;
 394                         sk->sk_write_space(sk);
 395                 }
 396                 if (sk->sk_state == TCP_ESTABLISHED)
 397                         break; /* Nothing to do */
 398                 sk->sk_state = TCP_ESTABLISHED;
 399                 pipe_grant_credits(sk);
 400                 break;
 401
 402         case PNS_PIPE_DISABLED_IND:
 403                 sk->sk_state = TCP_SYN_RECV;
 404                 pn->rx_credits = 0;
 405                 break;
 406
 407         default:
 408                 LIMIT_NETDEBUG(KERN_DEBUG"Phonet unknown PEP message: %u\n",
 409                                 hdr->message_id);
 410                 err = -EINVAL;
 411         }
 412 out:
 413         kfree_skb(skb);
 414         return err;
 415 }
 416
 417 /* Destroy connected sock. */
 418 static void pipe_destruct(struct sock *sk)
 419 {
 420         skb_queue_purge(&sk->sk_receive_queue);
 421 }
 422
 423 static int pep_connreq_rcv(struct sock *sk, struct sk_buff *skb)
 424 {
 425         struct sock *newsk;
 426         struct pep_sock *newpn, *pn = pep_sk(sk);
 427         struct pnpipehdr *hdr;
 428         struct sockaddr_pn dst;
 429         u16 peer_type;
 430         u8 pipe_handle, enabled, n_sb;
 431
 432         if (!pskb_pull(skb, sizeof(*hdr) + 4))
 433                 return -EINVAL;
 434
 435         hdr = pnp_hdr(skb);
 436         pipe_handle = hdr->pipe_handle;
 437         switch (hdr->state_after_connect) {
 438         case PN_PIPE_DISABLE:
 439                 enabled = 0;
 440                 break;
 441         case PN_PIPE_ENABLE:
 442                 enabled = 1;
 443                 break;
 444         default:
 445                 pep_reject_conn(sk, skb, PN_PIPE_ERR_INVALID_PARAM);
 446                 return -EINVAL;
 447         }
 448         peer_type = hdr->other_pep_type << 8;
 449
 450         if (unlikely(sk->sk_state != TCP_LISTEN) || sk_acceptq_is_full(sk)) {
 451                 pep_reject_conn(sk, skb, PN_PIPE_ERR_PEP_IN_USE);
 452                 return -ENOBUFS;
 453         }
 454
 455         /* Parse sub-blocks (options) */
 456         n_sb = hdr->data[4];
 457         while (n_sb > 0) {
 458                 u8 type, buf[1], len = sizeof(buf);
 459                 const u8 *data = pep_get_sb(skb, &type, &len, buf);
 460
 461                 if (data == NULL)
 462                         return -EINVAL;
 463                 switch (type) {
 464                 case PN_PIPE_SB_CONNECT_REQ_PEP_SUB_TYPE:
 465                         if (len < 1)
 466                                 return -EINVAL;
 467                         peer_type = (peer_type & 0xff00) | data[0];
 468                         break;
 469                 }
 470                 n_sb--;
 471         }
 472
 473         skb = skb_clone(skb, GFP_ATOMIC);
 474         if (!skb)
 475                 return -ENOMEM;
 476
 477         /* Create a new to-be-accepted sock */
 478         newsk = sk_alloc(sock_net(sk), PF_PHONET, GFP_ATOMIC, sk->sk_prot);
 479         if (!newsk) {
 480                 kfree_skb(skb);
 481                 return -ENOMEM;
 482         }
 483         sock_init_data(NULL, newsk);
 484         newsk->sk_state = TCP_SYN_RECV;
 485         newsk->sk_backlog_rcv = pipe_do_rcv;
 486         newsk->sk_protocol = sk->sk_protocol;
 487         newsk->sk_destruct = pipe_destruct;
 488
 489         newpn = pep_sk(newsk);
 490         pn_skb_get_dst_sockaddr(skb, &dst);
 491         newpn->pn_sk.sobject = pn_sockaddr_get_object(&dst);
 492         newpn->pn_sk.resource = pn->pn_sk.resource;
 493         newpn->pipe_handle = pipe_handle;
 494         newpn->peer_type = peer_type;
 495         newpn->rx_credits = newpn->tx_credits = 0;
 496         newpn->rx_fc = newpn->tx_fc = PN_LEGACY_FLOW_CONTROL;
 497         newpn->init_enable = enabled;
 498
 499         BUG_ON(!skb_queue_empty(&newsk->sk_receive_queue));
 500         skb_queue_head(&newsk->sk_receive_queue, skb);
 501         if (!sock_flag(sk, SOCK_DEAD))
 502                 sk->sk_data_ready(sk, 0);
 503
 504         sk_acceptq_added(sk);
 505         sk_add_node(newsk, &pn->ackq);
 506         return 0;
 507 }
 508
 509 /* Listening sock must be locked */
 510 static struct sock *pep_find_pipe(const struct hlist_head *hlist,
 511                                         const struct sockaddr_pn *dst,
 512                                         u8 pipe_handle)
 513 {
 514         struct hlist_node *node;
 515         struct sock *sknode;
 516         u16 dobj = pn_sockaddr_get_object(dst);
 517
 518         sk_for_each(sknode, node, hlist) {
 519                 struct pep_sock *pnnode = pep_sk(sknode);
 520
 521                 /* Ports match, but addresses might not: */
 522                 if (pnnode->pn_sk.sobject != dobj)
 523                         continue;
 524                 if (pnnode->pipe_handle != pipe_handle)
 525                         continue;
 526                 if (sknode->sk_state == TCP_CLOSE_WAIT)
 527                         continue;
 528
 529                 sock_hold(sknode);
 530                 return sknode;
 531         }
 532         return NULL;
 533 }
 534
 535 /*
 536  * Deliver an skb to a listening sock.
 537  * Socket lock must be held.
 538  * We then queue the skb to the right connected sock (if any).
 539  */
 540 static int pep_do_rcv(struct sock *sk, struct sk_buff *skb)
 541 {
 542         struct pep_sock *pn = pep_sk(sk);
 543         struct sock *sknode;
 544         struct pnpipehdr *hdr = pnp_hdr(skb);
 545         struct sockaddr_pn dst;
 546         int err = NET_RX_SUCCESS;
 547         u8 pipe_handle;
 548
 549         if (!pskb_may_pull(skb, sizeof(*hdr)))
 550                 goto drop;
 551
 552         hdr = pnp_hdr(skb);
 553         pipe_handle = hdr->pipe_handle;
 554         if (pipe_handle == PN_PIPE_INVALID_HANDLE)
 555                 goto drop;
 556
 557         pn_skb_get_dst_sockaddr(skb, &dst);
 558
 559         /* Look for an existing pipe handle */
 560         sknode = pep_find_pipe(&pn->hlist, &dst, pipe_handle);
 561         if (sknode)
 562                 return sk_receive_skb(sknode, skb, 1);
 563
 564         /* Look for a pipe handle pending accept */
 565         sknode = pep_find_pipe(&pn->ackq, &dst, pipe_handle);
 566         if (sknode) {
 567                 sock_put(sknode);
 568                 if (net_ratelimit())
 569                         printk(KERN_WARNING"Phonet unconnected PEP ignored");
 570                 err = NET_RX_DROP;
 571                 goto drop;
 572         }
 573
 574         switch (hdr->message_id) {
 575         case PNS_PEP_CONNECT_REQ:
 576                 err = pep_connreq_rcv(sk, skb);
 577                 break;
 578
 579         case PNS_PEP_DISCONNECT_REQ:
 580                 pep_reply(sk, skb, PN_PIPE_NO_ERROR, NULL, 0, GFP_ATOMIC);
 581                 break;
 582
 583         case PNS_PEP_CTRL_REQ:
 584                 pep_ctrlreq_error(sk, skb, PN_PIPE_INVALID_HANDLE);
 585                 break;
 586
 587         case PNS_PEP_RESET_REQ:
 588         case PNS_PEP_ENABLE_REQ:
 589         case PNS_PEP_DISABLE_REQ:
 590                 /* invalid handle is not even allowed here! */
 591         default:
 592                 err = NET_RX_DROP;
 593         }
 594 drop:
 595         kfree_skb(skb);
 596         return err;
 597 }
 598
 599 /* associated socket ceases to exist */
 600 static void pep_sock_close(struct sock *sk, long timeout)
 601 {
 602         struct pep_sock *pn = pep_sk(sk);
 603
 604         sk_common_release(sk);
 605
 606         lock_sock(sk);
 607         if (sk->sk_state == TCP_LISTEN) {
 608                 /* Destroy the listen queue */
 609                 struct sock *sknode;
 610                 struct hlist_node *p, *n;
 611
 612                 sk_for_each_safe(sknode, p, n, &pn->ackq)
 613                         sk_del_node_init(sknode);
 614                 sk->sk_state = TCP_CLOSE;
 615         }
 616         release_sock(sk);
 617 }
 618
 619 static int pep_wait_connreq(struct sock *sk, int noblock)
 620 {
 621         struct task_struct *tsk = current;
 622         struct pep_sock *pn = pep_sk(sk);
 623         long timeo = sock_rcvtimeo(sk, noblock);
 624
 625         for (;;) {
 626                 DEFINE_WAIT(wait);
 627
 628                 if (sk->sk_state != TCP_LISTEN)
 629                         return -EINVAL;
 630                 if (!hlist_empty(&pn->ackq))
 631                         break;
 632                 if (!timeo)
 633                         return -EWOULDBLOCK;
 634                 if (signal_pending(tsk))
 635                         return sock_intr_errno(timeo);
 636
 637                 prepare_to_wait_exclusive(&sk->sk_socket->wait, &wait,
 638                                                 TASK_INTERRUPTIBLE);
 639                 release_sock(sk);
 640                 timeo = schedule_timeout(timeo);
 641                 lock_sock(sk);
 642                 finish_wait(&sk->sk_socket->wait, &wait);
 643         }
 644
 645         return 0;
 646 }
 647
 648 static struct sock *pep_sock_accept(struct sock *sk, int flags, int *errp)
 649 {
 650         struct pep_sock *pn = pep_sk(sk);
 651         struct sock *newsk = NULL;
 652         struct sk_buff *oskb;
 653         int err;
 654
 655         lock_sock(sk);
 656         err = pep_wait_connreq(sk, flags & O_NONBLOCK);
 657         if (err)
 658                 goto out;
 659
 660         newsk = __sk_head(&pn->ackq);
 661
 662         oskb = skb_dequeue(&newsk->sk_receive_queue);
 663         err = pep_accept_conn(newsk, oskb);
 664         if (err) {
 665                 skb_queue_head(&newsk->sk_receive_queue, oskb);
 666                 newsk = NULL;
 667                 goto out;
 668         }
 669
 670         sock_hold(sk);
 671         pep_sk(newsk)->listener = sk;
 672
 673         sock_hold(newsk);
 674         sk_del_node_init(newsk);
 675         sk_acceptq_removed(sk);
 676         sk_add_node(newsk, &pn->hlist);
 677         __sock_put(newsk);
 678
 679 out:
 680         release_sock(sk);
 681         *errp = err;
 682         return newsk;
 683 }
 684
 685 static int pep_ioctl(struct sock *sk, int cmd, unsigned long arg)
 686 {
 687         int answ;
 688
 689         switch (cmd) {
 690         case SIOCINQ:
 691                 if (sk->sk_state == TCP_LISTEN)
 692                         return -EINVAL;
 693
 694                 lock_sock(sk);
 695                 if (!skb_queue_empty(&sk->sk_receive_queue))
 696                         answ = skb_peek(&sk->sk_receive_queue)->len;
 697                 else
 698                         answ = 0;
 699                 release_sock(sk);
 700                 return put_user(answ, (int __user *)arg);
 701         }
 702
 703         return -ENOIOCTLCMD;
 704 }
 705
 706 static int pep_init(struct sock *sk)
 707 {
 708         struct pep_sock *pn = pep_sk(sk);
 709
 710         INIT_HLIST_HEAD(&pn->ackq);
 711         INIT_HLIST_HEAD(&pn->hlist);
 712         pn->pipe_handle = PN_PIPE_INVALID_HANDLE;
 713         return 0;
 714 }
 715
 716 static int pep_sendmsg(struct kiocb *iocb, struct sock *sk,
 717                         struct msghdr *msg, size_t len)
 718 {
 719         struct pep_sock *pn = pep_sk(sk);
 720         struct sk_buff *skb = NULL;
 721         struct pnpipehdr *ph;
 722         long timeo;
 723         int flags = msg->msg_flags;
 724         int err, done;
 725
 726         if (msg->msg_flags & MSG_OOB || !(msg->msg_flags & MSG_EOR))
 727                 return -EOPNOTSUPP;
 728
 729         lock_sock(sk);
 730         timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT);
 731         if ((1 << sk->sk_state) & (TCPF_LISTEN|TCPF_CLOSE)) {
 732                 err = -ENOTCONN;
 733                 goto out;
 734         }
 735         if (sk->sk_state != TCP_ESTABLISHED) {
 736                 /* Wait until the pipe gets to enabled state */
 737 disabled:
 738                 err = sk_stream_wait_connect(sk, &timeo);
 739                 if (err)
 740                         goto out;
 741
 742                 if (sk->sk_state == TCP_CLOSE_WAIT) {
 743                         err = -ECONNRESET;
 744                         goto out;
 745                 }
 746         }
 747         BUG_ON(sk->sk_state != TCP_ESTABLISHED);
 748
 749         /* Wait until flow control allows TX */
 750         done = pn->tx_credits > 0;
 751         while (!done) {
 752                 DEFINE_WAIT(wait);
 753
 754                 if (!timeo) {
 755                         err = -EAGAIN;
 756                         goto out;
 757                 }
 758                 if (signal_pending(current)) {
 759                         err = sock_intr_errno(timeo);
 760                         goto out;
 761                 }
 762
 763                 prepare_to_wait(&sk->sk_socket->wait, &wait,
 764                                 TASK_INTERRUPTIBLE);
 765                 done = sk_wait_event(sk, &timeo, pn->tx_credits > 0);
 766                 finish_wait(&sk->sk_socket->wait, &wait);
 767
 768                 if (sk->sk_state != TCP_ESTABLISHED)
 769                         goto disabled;
 770         }
 771
 772         if (!skb) {
 773                 skb = sock_alloc_send_skb(sk, MAX_PNPIPE_HEADER + len,
 774                                                 flags & MSG_DONTWAIT, &err);
 775                 if (skb == NULL)
 776                         goto out;
 777                 skb_reserve(skb, MAX_PHONET_HEADER + 3);
 778
 779                 if (sk->sk_state != TCP_ESTABLISHED || !pn->tx_credits)
 780                         goto disabled; /* sock_alloc_send_skb might sleep */
 781         }
 782
 783         err = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len);
 784         if (err < 0)
 785                 goto out;
 786
 787         __skb_push(skb, 3);
 788         skb_reset_transport_header(skb);
 789         ph = pnp_hdr(skb);
 790         ph->utid = 0;
 791         ph->message_id = PNS_PIPE_DATA;
 792         ph->pipe_handle = pn->pipe_handle;
 793         if (pn_flow_safe(pn->tx_fc)) /* credit-based flow control */
 794                 pn->tx_credits--;
 795
 796         err = pn_skb_send(sk, skb, &pipe_srv);
 797         if (err >= 0)
 798                 err = len; /* success! */
 799         skb = NULL;
 800 out:
 801         release_sock(sk);
 802         kfree_skb(skb);
 803         return err;
 804 }
 805
 806 static int pep_recvmsg(struct kiocb *iocb, struct sock *sk,
 807                         struct msghdr *msg, size_t len, int noblock,
 808                         int flags, int *addr_len)
 809 {
 810         struct sk_buff *skb;
 811         int err;
 812
 813         if (unlikely(flags & MSG_OOB))
 814                 return -EOPNOTSUPP;
 815         if (unlikely(1 << sk->sk_state & (TCPF_LISTEN | TCPF_CLOSE)))
 816                 return -ENOTCONN;
 817
 818         skb = skb_recv_datagram(sk, flags, noblock, &err);
 819         lock_sock(sk);
 820         if (skb == NULL) {
 821                 if (err == -ENOTCONN && sk->sk_state == TCP_CLOSE_WAIT)
 822                         err = -ECONNRESET;
 823                 release_sock(sk);
 824                 return err;
 825         }
 826
 827         if (sk->sk_state == TCP_ESTABLISHED)
 828                 pipe_grant_credits(sk);
 829         release_sock(sk);
 830
 831         msg->msg_flags |= MSG_EOR;
 832
 833         if (skb->len > len)
 834                 msg->msg_flags |= MSG_TRUNC;
 835         else
 836                 len = skb->len;
 837
 838         err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, len);
 839         if (!err)
 840                 err = (flags & MSG_TRUNC) ? skb->len : len;
 841
 842         skb_free_datagram(sk, skb);
 843         return err;
 844 }
 845
 846 static void pep_sock_unhash(struct sock *sk)
 847 {
 848         struct pep_sock *pn = pep_sk(sk);
 849         struct sock *skparent = NULL;
 850
 851         lock_sock(sk);
 852         if ((1 << sk->sk_state) & ~(TCPF_CLOSE|TCPF_LISTEN)) {
 853                 skparent = pn->listener;
 854                 sk_del_node_init(sk);
 855                 release_sock(sk);
 856
 857                 sk = skparent;
 858                 pn = pep_sk(skparent);
 859                 lock_sock(sk);
 860         }
 861         /* Unhash a listening sock only when it is closed
 862          * and all of its active connected pipes are closed. */
 863         if (hlist_empty(&pn->hlist))
 864                 pn_sock_unhash(&pn->pn_sk.sk);
 865         release_sock(sk);
 866
 867         if (skparent)
 868                 sock_put(skparent);
 869 }
 870
 871 static struct proto pep_proto = {
 872         .close          = pep_sock_close,
 873         .accept         = pep_sock_accept,
 874         .ioctl          = pep_ioctl,
 875         .init           = pep_init,
 876         .sendmsg        = pep_sendmsg,
 877         .recvmsg        = pep_recvmsg,
 878         .backlog_rcv    = pep_do_rcv,
 879         .hash           = pn_sock_hash,
 880         .unhash         = pep_sock_unhash,
 881         .get_port       = pn_sock_get_port,
 882         .obj_size       = sizeof(struct pep_sock),
 883         .owner          = THIS_MODULE,
 884         .name           = "PNPIPE",
 885 };
 886
 887 static struct phonet_protocol pep_pn_proto = {
 888         .ops            = &phonet_stream_ops,
 889         .prot           = &pep_proto,
 890         .sock_type      = SOCK_SEQPACKET,
 891 };
 892
 893 static int __init pep_register(void)
 894 {
 895         return phonet_proto_register(PN_PROTO_PIPE, &pep_pn_proto);
 896 }
 897
 898 static void __exit pep_unregister(void)
 899 {
 900         phonet_proto_unregister(PN_PROTO_PIPE, &pep_pn_proto);
 901 }
 902
 903 module_init(pep_register);
 904 module_exit(pep_unregister);
 905 MODULE_AUTHOR("Remi Denis-Courmont, Nokia");
 906 MODULE_DESCRIPTION("Phonet pipe protocol");
 907 MODULE_LICENSE("GPL");
 908 MODULE_ALIAS_NET_PF_PROTO(PF_PHONET, PN_PROTO_PIPE);