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 <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 #include <net/phonet/gprs.h>
  35
  36 /* sk_state values:
  37  * TCP_CLOSE            sock not in use yet
  38  * TCP_CLOSE_WAIT       disconnected pipe
  39  * TCP_LISTEN           listening pipe endpoint
  40  * TCP_SYN_RECV         connected pipe in disabled state
  41  * TCP_ESTABLISHED      connected pipe in enabled state
  42  *
  43  * pep_sock locking:
  44  *  - sk_state, ackq, hlist: sock lock needed
  45  *  - listener: read only
  46  *  - pipe_handle: read only
  47  */
  48
  49 #define CREDITS_MAX     10
  50 #define CREDITS_THR     7
  51
  52 static const struct sockaddr_pn pipe_srv = {
  53         .spn_family = AF_PHONET,
  54         .spn_resource = 0xD9, /* pipe service */
  55 };
  56
  57 #define pep_sb_size(s) (((s) + 5) & ~3) /* 2-bytes head, 32-bits aligned */
  58
  59 /* Get the next TLV sub-block. */
  60 static unsigned char *pep_get_sb(struct sk_buff *skb, u8 *ptype, u8 *plen,
  61                                         void *buf)
  62 {
  63         void *data = NULL;
  64         struct {
  65                 u8 sb_type;
  66                 u8 sb_len;
  67         } *ph, h;
  68         int buflen = *plen;
  69
  70         ph = skb_header_pointer(skb, 0, 2, &h);
  71         if (ph == NULL || ph->sb_len < 2 || !pskb_may_pull(skb, ph->sb_len))
  72                 return NULL;
  73         ph->sb_len -= 2;
  74         *ptype = ph->sb_type;
  75         *plen = ph->sb_len;
  76
  77         if (buflen > ph->sb_len)
  78                 buflen = ph->sb_len;
  79         data = skb_header_pointer(skb, 2, buflen, buf);
  80         __skb_pull(skb, 2 + ph->sb_len);
  81         return data;
  82 }
  83
  84 static int pep_reply(struct sock *sk, struct sk_buff *oskb,
  85                         u8 code, const void *data, int len, gfp_t priority)
  86 {
  87         const struct pnpipehdr *oph = pnp_hdr(oskb);
  88         struct pnpipehdr *ph;
  89         struct sk_buff *skb;
  90
  91         skb = alloc_skb(MAX_PNPIPE_HEADER + len, priority);
  92         if (!skb)
  93                 return -ENOMEM;
  94         skb_set_owner_w(skb, sk);
  95
  96         skb_reserve(skb, MAX_PNPIPE_HEADER);
  97         __skb_put(skb, len);
  98         skb_copy_to_linear_data(skb, data, len);
  99         __skb_push(skb, sizeof(*ph));
 100         skb_reset_transport_header(skb);
 101         ph = pnp_hdr(skb);
 102         ph->utid = oph->utid;
 103         ph->message_id = oph->message_id + 1; /* REQ -> RESP */
 104         ph->pipe_handle = oph->pipe_handle;
 105         ph->error_code = code;
 106
 107         return pn_skb_send(sk, skb, &pipe_srv);
 108 }
 109
 110 #define PAD 0x00
 111 static int pep_accept_conn(struct sock *sk, struct sk_buff *skb)
 112 {
 113         static const u8 data[20] = {
 114                 PAD, PAD, PAD, 2 /* sub-blocks */,
 115                 PN_PIPE_SB_REQUIRED_FC_TX, pep_sb_size(5), 3, PAD,
 116                         PN_MULTI_CREDIT_FLOW_CONTROL,
 117                         PN_ONE_CREDIT_FLOW_CONTROL,
 118                         PN_LEGACY_FLOW_CONTROL,
 119                         PAD,
 120                 PN_PIPE_SB_PREFERRED_FC_RX, pep_sb_size(5), 3, PAD,
 121                         PN_MULTI_CREDIT_FLOW_CONTROL,
 122                         PN_ONE_CREDIT_FLOW_CONTROL,
 123                         PN_LEGACY_FLOW_CONTROL,
 124                         PAD,
 125         };
 126
 127         might_sleep();
 128         return pep_reply(sk, skb, PN_PIPE_NO_ERROR, data, sizeof(data),
 129                                 GFP_KERNEL);
 130 }
 131
 132 static int pep_reject_conn(struct sock *sk, struct sk_buff *skb, u8 code)
 133 {
 134         static const u8 data[4] = { PAD, PAD, PAD, 0 /* sub-blocks */ };
 135         WARN_ON(code == PN_PIPE_NO_ERROR);
 136         return pep_reply(sk, skb, code, data, sizeof(data), GFP_ATOMIC);
 137 }
 138
 139 /* Control requests are not sent by the pipe service and have a specific
 140  * message format. */
 141 static int pep_ctrlreq_error(struct sock *sk, struct sk_buff *oskb, u8 code,
 142                                 gfp_t priority)
 143 {
 144         const struct pnpipehdr *oph = pnp_hdr(oskb);
 145         struct sk_buff *skb;
 146         struct pnpipehdr *ph;
 147         struct sockaddr_pn dst;
 148
 149         skb = alloc_skb(MAX_PNPIPE_HEADER + 4, priority);
 150         if (!skb)
 151                 return -ENOMEM;
 152         skb_set_owner_w(skb, sk);
 153
 154         skb_reserve(skb, MAX_PHONET_HEADER);
 155         ph = (struct pnpipehdr *)skb_put(skb, sizeof(*ph) + 4);
 156
 157         ph->utid = oph->utid;
 158         ph->message_id = PNS_PEP_CTRL_RESP;
 159         ph->pipe_handle = oph->pipe_handle;
 160         ph->data[0] = oph->data[1]; /* CTRL id */
 161         ph->data[1] = oph->data[0]; /* PEP type */
 162         ph->data[2] = code; /* error code, at an usual offset */
 163         ph->data[3] = PAD;
 164         ph->data[4] = PAD;
 165
 166         pn_skb_get_src_sockaddr(oskb, &dst);
 167         return pn_skb_send(sk, skb, &dst);
 168 }
 169
 170 static int pipe_snd_status(struct sock *sk, u8 type, u8 status, gfp_t priority)
 171 {
 172         struct pep_sock *pn = pep_sk(sk);
 173         struct pnpipehdr *ph;
 174         struct sk_buff *skb;
 175
 176         skb = alloc_skb(MAX_PNPIPE_HEADER + 4, priority);
 177         if (!skb)
 178                 return -ENOMEM;
 179         skb_set_owner_w(skb, sk);
 180
 181         skb_reserve(skb, MAX_PNPIPE_HEADER + 4);
 182         __skb_push(skb, sizeof(*ph) + 4);
 183         skb_reset_transport_header(skb);
 184         ph = pnp_hdr(skb);
 185         ph->utid = 0;
 186         ph->message_id = PNS_PEP_STATUS_IND;
 187         ph->pipe_handle = pn->pipe_handle;
 188         ph->pep_type = PN_PEP_TYPE_COMMON;
 189         ph->data[1] = type;
 190         ph->data[2] = PAD;
 191         ph->data[3] = PAD;
 192         ph->data[4] = status;
 193
 194         return pn_skb_send(sk, skb, &pipe_srv);
 195 }
 196
 197 /* Send our RX flow control information to the sender.
 198  * Socket must be locked. */
 199 static void pipe_grant_credits(struct sock *sk)
 200 {
 201         struct pep_sock *pn = pep_sk(sk);
 202
 203         BUG_ON(sk->sk_state != TCP_ESTABLISHED);
 204
 205         switch (pn->rx_fc) {
 206         case PN_LEGACY_FLOW_CONTROL: /* TODO */
 207                 break;
 208         case PN_ONE_CREDIT_FLOW_CONTROL:
 209                 pipe_snd_status(sk, PN_PEP_IND_FLOW_CONTROL,
 210                                 PEP_IND_READY, GFP_ATOMIC);
 211                 pn->rx_credits = 1;
 212                 break;
 213         case PN_MULTI_CREDIT_FLOW_CONTROL:
 214                 if ((pn->rx_credits + CREDITS_THR) > CREDITS_MAX)
 215                         break;
 216                 if (pipe_snd_status(sk, PN_PEP_IND_ID_MCFC_GRANT_CREDITS,
 217                                         CREDITS_MAX - pn->rx_credits,
 218                                         GFP_ATOMIC) == 0)
 219                         pn->rx_credits = CREDITS_MAX;
 220                 break;
 221         }
 222 }
 223
 224 static int pipe_rcv_status(struct sock *sk, struct sk_buff *skb)
 225 {
 226         struct pep_sock *pn = pep_sk(sk);
 227         struct pnpipehdr *hdr;
 228         int wake = 0;
 229
 230         if (!pskb_may_pull(skb, sizeof(*hdr) + 4))
 231                 return -EINVAL;
 232
 233         hdr = pnp_hdr(skb);
 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_DATA:
 359                 __skb_pull(skb, 3); /* Pipe data header */
 360                 if (!pn_flow_safe(pn->rx_fc)) {
 361                         err = sock_queue_rcv_skb(sk, skb);
 362                         if (!err)
 363                                 return 0;
 364                         if (err == -ENOMEM)
 365                                 atomic_inc(&sk->sk_drops);
 366                         break;
 367                 }
 368
 369                 if (pn->rx_credits == 0) {
 370                         atomic_inc(&sk->sk_drops);
 371                         err = -ENOBUFS;
 372                         break;
 373                 }
 374                 pn->rx_credits--;
 375                 queue = &sk->sk_receive_queue;
 376                 goto queue;
 377
 378         case PNS_PEP_STATUS_IND:
 379                 pipe_rcv_status(sk, skb);
 380                 break;
 381
 382         case PNS_PIPE_REDIRECTED_IND:
 383                 err = pipe_rcv_created(sk, skb);
 384                 break;
 385
 386         case PNS_PIPE_CREATED_IND:
 387                 err = pipe_rcv_created(sk, skb);
 388                 if (err)
 389                         break;
 390                 /* fall through */
 391         case PNS_PIPE_RESET_IND:
 392                 if (!pn->init_enable)
 393                         break;
 394                 /* fall through */
 395         case PNS_PIPE_ENABLED_IND:
 396                 if (!pn_flow_safe(pn->tx_fc)) {
 397                         atomic_set(&pn->tx_credits, 1);
 398                         sk->sk_write_space(sk);
 399                 }
 400                 if (sk->sk_state == TCP_ESTABLISHED)
 401                         break; /* Nothing to do */
 402                 sk->sk_state = TCP_ESTABLISHED;
 403                 pipe_grant_credits(sk);
 404                 break;
 405
 406         case PNS_PIPE_DISABLED_IND:
 407                 sk->sk_state = TCP_SYN_RECV;
 408                 pn->rx_credits = 0;
 409                 break;
 410
 411         default:
 412                 LIMIT_NETDEBUG(KERN_DEBUG"Phonet unknown PEP message: %u\n",
 413                                 hdr->message_id);
 414                 err = -EINVAL;
 415         }
 416 out:
 417         kfree_skb(skb);
 418         return err;
 419
 420 queue:
 421         skb->dev = NULL;
 422         skb_set_owner_r(skb, sk);
 423         err = skb->len;
 424         skb_queue_tail(queue, skb);
 425         if (!sock_flag(sk, SOCK_DEAD))
 426                 sk->sk_data_ready(sk, err);
 427         return 0;
 428 }
 429
 430 /* Destroy connected sock. */
 431 static void pipe_destruct(struct sock *sk)
 432 {
 433         struct pep_sock *pn = pep_sk(sk);
 434
 435         skb_queue_purge(&sk->sk_receive_queue);
 436         skb_queue_purge(&pn->ctrlreq_queue);
 437 }
 438
 439 static int pep_connreq_rcv(struct sock *sk, struct sk_buff *skb)
 440 {
 441         struct sock *newsk;
 442         struct pep_sock *newpn, *pn = pep_sk(sk);
 443         struct pnpipehdr *hdr;
 444         struct sockaddr_pn dst;
 445         u16 peer_type;
 446         u8 pipe_handle, enabled, n_sb;
 447
 448         if (!pskb_pull(skb, sizeof(*hdr) + 4))
 449                 return -EINVAL;
 450
 451         hdr = pnp_hdr(skb);
 452         pipe_handle = hdr->pipe_handle;
 453         switch (hdr->state_after_connect) {
 454         case PN_PIPE_DISABLE:
 455                 enabled = 0;
 456                 break;
 457         case PN_PIPE_ENABLE:
 458                 enabled = 1;
 459                 break;
 460         default:
 461                 pep_reject_conn(sk, skb, PN_PIPE_ERR_INVALID_PARAM);
 462                 return -EINVAL;
 463         }
 464         peer_type = hdr->other_pep_type << 8;
 465
 466         if (unlikely(sk->sk_state != TCP_LISTEN) || sk_acceptq_is_full(sk)) {
 467                 pep_reject_conn(sk, skb, PN_PIPE_ERR_PEP_IN_USE);
 468                 return -ENOBUFS;
 469         }
 470
 471         /* Parse sub-blocks (options) */
 472         n_sb = hdr->data[4];
 473         while (n_sb > 0) {
 474                 u8 type, buf[1], len = sizeof(buf);
 475                 const u8 *data = pep_get_sb(skb, &type, &len, buf);
 476
 477                 if (data == NULL)
 478                         return -EINVAL;
 479                 switch (type) {
 480                 case PN_PIPE_SB_CONNECT_REQ_PEP_SUB_TYPE:
 481                         if (len < 1)
 482                                 return -EINVAL;
 483                         peer_type = (peer_type & 0xff00) | data[0];
 484                         break;
 485                 }
 486                 n_sb--;
 487         }
 488
 489         skb = skb_clone(skb, GFP_ATOMIC);
 490         if (!skb)
 491                 return -ENOMEM;
 492
 493         /* Create a new to-be-accepted sock */
 494         newsk = sk_alloc(sock_net(sk), PF_PHONET, GFP_ATOMIC, sk->sk_prot);
 495         if (!newsk) {
 496                 kfree_skb(skb);
 497                 return -ENOMEM;
 498         }
 499         sock_init_data(NULL, newsk);
 500         newsk->sk_state = TCP_SYN_RECV;
 501         newsk->sk_backlog_rcv = pipe_do_rcv;
 502         newsk->sk_protocol = sk->sk_protocol;
 503         newsk->sk_destruct = pipe_destruct;
 504
 505         newpn = pep_sk(newsk);
 506         pn_skb_get_dst_sockaddr(skb, &dst);
 507         newpn->pn_sk.sobject = pn_sockaddr_get_object(&dst);
 508         newpn->pn_sk.resource = pn->pn_sk.resource;
 509         skb_queue_head_init(&newpn->ctrlreq_queue);
 510         newpn->pipe_handle = pipe_handle;
 511         atomic_set(&newpn->tx_credits, 0);
 512         newpn->peer_type = peer_type;
 513         newpn->rx_credits = 0;
 514         newpn->rx_fc = newpn->tx_fc = PN_LEGACY_FLOW_CONTROL;
 515         newpn->init_enable = enabled;
 516
 517         BUG_ON(!skb_queue_empty(&newsk->sk_receive_queue));
 518         skb_queue_head(&newsk->sk_receive_queue, skb);
 519         if (!sock_flag(sk, SOCK_DEAD))
 520                 sk->sk_data_ready(sk, 0);
 521
 522         sk_acceptq_added(sk);
 523         sk_add_node(newsk, &pn->ackq);
 524         return 0;
 525 }
 526
 527 /* Listening sock must be locked */
 528 static struct sock *pep_find_pipe(const struct hlist_head *hlist,
 529                                         const struct sockaddr_pn *dst,
 530                                         u8 pipe_handle)
 531 {
 532         struct hlist_node *node;
 533         struct sock *sknode;
 534         u16 dobj = pn_sockaddr_get_object(dst);
 535
 536         sk_for_each(sknode, node, hlist) {
 537                 struct pep_sock *pnnode = pep_sk(sknode);
 538
 539                 /* Ports match, but addresses might not: */
 540                 if (pnnode->pn_sk.sobject != dobj)
 541                         continue;
 542                 if (pnnode->pipe_handle != pipe_handle)
 543                         continue;
 544                 if (sknode->sk_state == TCP_CLOSE_WAIT)
 545                         continue;
 546
 547                 sock_hold(sknode);
 548                 return sknode;
 549         }
 550         return NULL;
 551 }
 552
 553 /*
 554  * Deliver an skb to a listening sock.
 555  * Socket lock must be held.
 556  * We then queue the skb to the right connected sock (if any).
 557  */
 558 static int pep_do_rcv(struct sock *sk, struct sk_buff *skb)
 559 {
 560         struct pep_sock *pn = pep_sk(sk);
 561         struct sock *sknode;
 562         struct pnpipehdr *hdr;
 563         struct sockaddr_pn dst;
 564         int err = NET_RX_SUCCESS;
 565         u8 pipe_handle;
 566
 567         if (!pskb_may_pull(skb, sizeof(*hdr)))
 568                 goto drop;
 569
 570         hdr = pnp_hdr(skb);
 571         pipe_handle = hdr->pipe_handle;
 572         if (pipe_handle == PN_PIPE_INVALID_HANDLE)
 573                 goto drop;
 574
 575         pn_skb_get_dst_sockaddr(skb, &dst);
 576
 577         /* Look for an existing pipe handle */
 578         sknode = pep_find_pipe(&pn->hlist, &dst, pipe_handle);
 579         if (sknode)
 580                 return sk_receive_skb(sknode, skb, 1);
 581
 582         /* Look for a pipe handle pending accept */
 583         sknode = pep_find_pipe(&pn->ackq, &dst, pipe_handle);
 584         if (sknode) {
 585                 sock_put(sknode);
 586                 if (net_ratelimit())
 587                         printk(KERN_WARNING"Phonet unconnected PEP ignored");
 588                 err = NET_RX_DROP;
 589                 goto drop;
 590         }
 591
 592         switch (hdr->message_id) {
 593         case PNS_PEP_CONNECT_REQ:
 594                 err = pep_connreq_rcv(sk, skb);
 595                 break;
 596
 597         case PNS_PEP_DISCONNECT_REQ:
 598                 pep_reply(sk, skb, PN_PIPE_NO_ERROR, NULL, 0, GFP_ATOMIC);
 599                 break;
 600
 601         case PNS_PEP_CTRL_REQ:
 602                 pep_ctrlreq_error(sk, skb, PN_PIPE_INVALID_HANDLE, GFP_ATOMIC);
 603                 break;
 604
 605         case PNS_PEP_RESET_REQ:
 606         case PNS_PEP_ENABLE_REQ:
 607         case PNS_PEP_DISABLE_REQ:
 608                 /* invalid handle is not even allowed here! */
 609         default:
 610                 err = NET_RX_DROP;
 611         }
 612 drop:
 613         kfree_skb(skb);
 614         return err;
 615 }
 616
 617 /* associated socket ceases to exist */
 618 static void pep_sock_close(struct sock *sk, long timeout)
 619 {
 620         struct pep_sock *pn = pep_sk(sk);
 621         int ifindex = 0;
 622
 623         sk_common_release(sk);
 624
 625         lock_sock(sk);
 626         if (sk->sk_state == TCP_LISTEN) {
 627                 /* Destroy the listen queue */
 628                 struct sock *sknode;
 629                 struct hlist_node *p, *n;
 630
 631                 sk_for_each_safe(sknode, p, n, &pn->ackq)
 632                         sk_del_node_init(sknode);
 633                 sk->sk_state = TCP_CLOSE;
 634         }
 635         ifindex = pn->ifindex;
 636         pn->ifindex = 0;
 637         release_sock(sk);
 638
 639         if (ifindex)
 640                 gprs_detach(sk);
 641 }
 642
 643 static int pep_wait_connreq(struct sock *sk, int noblock)
 644 {
 645         struct task_struct *tsk = current;
 646         struct pep_sock *pn = pep_sk(sk);
 647         long timeo = sock_rcvtimeo(sk, noblock);
 648
 649         for (;;) {
 650                 DEFINE_WAIT(wait);
 651
 652                 if (sk->sk_state != TCP_LISTEN)
 653                         return -EINVAL;
 654                 if (!hlist_empty(&pn->ackq))
 655                         break;
 656                 if (!timeo)
 657                         return -EWOULDBLOCK;
 658                 if (signal_pending(tsk))
 659                         return sock_intr_errno(timeo);
 660
 661                 prepare_to_wait_exclusive(&sk->sk_socket->wait, &wait,
 662                                                 TASK_INTERRUPTIBLE);
 663                 release_sock(sk);
 664                 timeo = schedule_timeout(timeo);
 665                 lock_sock(sk);
 666                 finish_wait(&sk->sk_socket->wait, &wait);
 667         }
 668
 669         return 0;
 670 }
 671
 672 static struct sock *pep_sock_accept(struct sock *sk, int flags, int *errp)
 673 {
 674         struct pep_sock *pn = pep_sk(sk);
 675         struct sock *newsk = NULL;
 676         struct sk_buff *oskb;
 677         int err;
 678
 679         lock_sock(sk);
 680         err = pep_wait_connreq(sk, flags & O_NONBLOCK);
 681         if (err)
 682                 goto out;
 683
 684         newsk = __sk_head(&pn->ackq);
 685
 686         oskb = skb_dequeue(&newsk->sk_receive_queue);
 687         err = pep_accept_conn(newsk, oskb);
 688         if (err) {
 689                 skb_queue_head(&newsk->sk_receive_queue, oskb);
 690                 newsk = NULL;
 691                 goto out;
 692         }
 693
 694         sock_hold(sk);
 695         pep_sk(newsk)->listener = sk;
 696
 697         sock_hold(newsk);
 698         sk_del_node_init(newsk);
 699         sk_acceptq_removed(sk);
 700         sk_add_node(newsk, &pn->hlist);
 701         __sock_put(newsk);
 702
 703 out:
 704         release_sock(sk);
 705         *errp = err;
 706         return newsk;
 707 }
 708
 709 static int pep_ioctl(struct sock *sk, int cmd, unsigned long arg)
 710 {
 711         struct pep_sock *pn = pep_sk(sk);
 712         int answ;
 713
 714         switch (cmd) {
 715         case SIOCINQ:
 716                 if (sk->sk_state == TCP_LISTEN)
 717                         return -EINVAL;
 718
 719                 lock_sock(sk);
 720                 if (sock_flag(sk, SOCK_URGINLINE)
 721                  && !skb_queue_empty(&pn->ctrlreq_queue))
 722                         answ = skb_peek(&pn->ctrlreq_queue)->len;
 723                 else if (!skb_queue_empty(&sk->sk_receive_queue))
 724                         answ = skb_peek(&sk->sk_receive_queue)->len;
 725                 else
 726                         answ = 0;
 727                 release_sock(sk);
 728                 return put_user(answ, (int __user *)arg);
 729         }
 730
 731         return -ENOIOCTLCMD;
 732 }
 733
 734 static int pep_init(struct sock *sk)
 735 {
 736         struct pep_sock *pn = pep_sk(sk);
 737
 738         INIT_HLIST_HEAD(&pn->ackq);
 739         INIT_HLIST_HEAD(&pn->hlist);
 740         skb_queue_head_init(&pn->ctrlreq_queue);
 741         pn->pipe_handle = PN_PIPE_INVALID_HANDLE;
 742         return 0;
 743 }
 744
 745 static int pep_setsockopt(struct sock *sk, int level, int optname,
 746                                 char __user *optval, unsigned int optlen)
 747 {
 748         struct pep_sock *pn = pep_sk(sk);
 749         int val = 0, err = 0;
 750
 751         if (level != SOL_PNPIPE)
 752                 return -ENOPROTOOPT;
 753         if (optlen >= sizeof(int)) {
 754                 if (get_user(val, (int __user *) optval))
 755                         return -EFAULT;
 756         }
 757
 758         lock_sock(sk);
 759         switch (optname) {
 760         case PNPIPE_ENCAP:
 761                 if (val && val != PNPIPE_ENCAP_IP) {
 762                         err = -EINVAL;
 763                         break;
 764                 }
 765                 if (!pn->ifindex == !val)
 766                         break; /* Nothing to do! */
 767                 if (!capable(CAP_NET_ADMIN)) {
 768                         err = -EPERM;
 769                         break;
 770                 }
 771                 if (val) {
 772                         release_sock(sk);
 773                         err = gprs_attach(sk);
 774                         if (err > 0) {
 775                                 pn->ifindex = err;
 776                                 err = 0;
 777                         }
 778                 } else {
 779                         pn->ifindex = 0;
 780                         release_sock(sk);
 781                         gprs_detach(sk);
 782                         err = 0;
 783                 }
 784                 goto out_norel;
 785         default:
 786                 err = -ENOPROTOOPT;
 787         }
 788         release_sock(sk);
 789
 790 out_norel:
 791         return err;
 792 }
 793
 794 static int pep_getsockopt(struct sock *sk, int level, int optname,
 795                                 char __user *optval, int __user *optlen)
 796 {
 797         struct pep_sock *pn = pep_sk(sk);
 798         int len, val;
 799
 800         if (level != SOL_PNPIPE)
 801                 return -ENOPROTOOPT;
 802         if (get_user(len, optlen))
 803                 return -EFAULT;
 804
 805         switch (optname) {
 806         case PNPIPE_ENCAP:
 807                 val = pn->ifindex ? PNPIPE_ENCAP_IP : PNPIPE_ENCAP_NONE;
 808                 break;
 809         case PNPIPE_IFINDEX:
 810                 val = pn->ifindex;
 811                 break;
 812         default:
 813                 return -ENOPROTOOPT;
 814         }
 815
 816         len = min_t(unsigned int, sizeof(int), len);
 817         if (put_user(len, optlen))
 818                 return -EFAULT;
 819         if (put_user(val, (int __user *) optval))
 820                 return -EFAULT;
 821         return 0;
 822 }
 823
 824 static int pipe_skb_send(struct sock *sk, struct sk_buff *skb)
 825 {
 826         struct pep_sock *pn = pep_sk(sk);
 827         struct pnpipehdr *ph;
 828
 829         if (pn_flow_safe(pn->tx_fc) &&
 830             !atomic_add_unless(&pn->tx_credits, -1, 0)) {
 831                 kfree_skb(skb);
 832                 return -ENOBUFS;
 833         }
 834
 835         skb_push(skb, 3);
 836         skb_reset_transport_header(skb);
 837         ph = pnp_hdr(skb);
 838         ph->utid = 0;
 839         ph->message_id = PNS_PIPE_DATA;
 840         ph->pipe_handle = pn->pipe_handle;
 841
 842         return pn_skb_send(sk, skb, &pipe_srv);
 843 }
 844
 845 static int pep_sendmsg(struct kiocb *iocb, struct sock *sk,
 846                         struct msghdr *msg, size_t len)
 847 {
 848         struct pep_sock *pn = pep_sk(sk);
 849         struct sk_buff *skb = NULL;
 850         long timeo;
 851         int flags = msg->msg_flags;
 852         int err, done;
 853
 854         if (msg->msg_flags & MSG_OOB || !(msg->msg_flags & MSG_EOR))
 855                 return -EOPNOTSUPP;
 856
 857         lock_sock(sk);
 858         timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT);
 859         if ((1 << sk->sk_state) & (TCPF_LISTEN|TCPF_CLOSE)) {
 860                 err = -ENOTCONN;
 861                 goto out;
 862         }
 863         if (sk->sk_state != TCP_ESTABLISHED) {
 864                 /* Wait until the pipe gets to enabled state */
 865 disabled:
 866                 err = sk_stream_wait_connect(sk, &timeo);
 867                 if (err)
 868                         goto out;
 869
 870                 if (sk->sk_state == TCP_CLOSE_WAIT) {
 871                         err = -ECONNRESET;
 872                         goto out;
 873                 }
 874         }
 875         BUG_ON(sk->sk_state != TCP_ESTABLISHED);
 876
 877         /* Wait until flow control allows TX */
 878         done = atomic_read(&pn->tx_credits);
 879         while (!done) {
 880                 DEFINE_WAIT(wait);
 881
 882                 if (!timeo) {
 883                         err = -EAGAIN;
 884                         goto out;
 885                 }
 886                 if (signal_pending(current)) {
 887                         err = sock_intr_errno(timeo);
 888                         goto out;
 889                 }
 890
 891                 prepare_to_wait(&sk->sk_socket->wait, &wait,
 892                                 TASK_INTERRUPTIBLE);
 893                 done = sk_wait_event(sk, &timeo, atomic_read(&pn->tx_credits));
 894                 finish_wait(&sk->sk_socket->wait, &wait);
 895
 896                 if (sk->sk_state != TCP_ESTABLISHED)
 897                         goto disabled;
 898         }
 899
 900         if (!skb) {
 901                 skb = sock_alloc_send_skb(sk, MAX_PNPIPE_HEADER + len,
 902                                                 flags & MSG_DONTWAIT, &err);
 903                 if (skb == NULL)
 904                         goto out;
 905                 skb_reserve(skb, MAX_PHONET_HEADER + 3);
 906
 907                 if (sk->sk_state != TCP_ESTABLISHED ||
 908                     !atomic_read(&pn->tx_credits))
 909                         goto disabled; /* sock_alloc_send_skb might sleep */
 910         }
 911
 912         err = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len);
 913         if (err < 0)
 914                 goto out;
 915
 916         err = pipe_skb_send(sk, skb);
 917         if (err >= 0)
 918                 err = len; /* success! */
 919         skb = NULL;
 920 out:
 921         release_sock(sk);
 922         kfree_skb(skb);
 923         return err;
 924 }
 925
 926 int pep_writeable(struct sock *sk)
 927 {
 928         struct pep_sock *pn = pep_sk(sk);
 929
 930         return atomic_read(&pn->tx_credits);
 931 }
 932
 933 int pep_write(struct sock *sk, struct sk_buff *skb)
 934 {
 935         struct sk_buff *rskb, *fs;
 936         int flen = 0;
 937
 938         rskb = alloc_skb(MAX_PNPIPE_HEADER, GFP_ATOMIC);
 939         if (!rskb) {
 940                 kfree_skb(skb);
 941                 return -ENOMEM;
 942         }
 943         skb_shinfo(rskb)->frag_list = skb;
 944         rskb->len += skb->len;
 945         rskb->data_len += rskb->len;
 946         rskb->truesize += rskb->len;
 947
 948         /* Avoid nested fragments */
 949         skb_walk_frags(skb, fs)
 950                 flen += fs->len;
 951         skb->next = skb_shinfo(skb)->frag_list;
 952         skb_frag_list_init(skb);
 953         skb->len -= flen;
 954         skb->data_len -= flen;
 955         skb->truesize -= flen;
 956
 957         skb_reserve(rskb, MAX_PHONET_HEADER + 3);
 958         return pipe_skb_send(sk, rskb);
 959 }
 960
 961 struct sk_buff *pep_read(struct sock *sk)
 962 {
 963         struct sk_buff *skb = skb_dequeue(&sk->sk_receive_queue);
 964
 965         if (sk->sk_state == TCP_ESTABLISHED)
 966                 pipe_grant_credits(sk);
 967         return skb;
 968 }
 969
 970 static int pep_recvmsg(struct kiocb *iocb, struct sock *sk,
 971                         struct msghdr *msg, size_t len, int noblock,
 972                         int flags, int *addr_len)
 973 {
 974         struct sk_buff *skb;
 975         int err;
 976
 977         if (unlikely(1 << sk->sk_state & (TCPF_LISTEN | TCPF_CLOSE)))
 978                 return -ENOTCONN;
 979
 980         if ((flags & MSG_OOB) || sock_flag(sk, SOCK_URGINLINE)) {
 981                 /* Dequeue and acknowledge control request */
 982                 struct pep_sock *pn = pep_sk(sk);
 983
 984                 skb = skb_dequeue(&pn->ctrlreq_queue);
 985                 if (skb) {
 986                         pep_ctrlreq_error(sk, skb, PN_PIPE_NO_ERROR,
 987                                                 GFP_KERNEL);
 988                         msg->msg_flags |= MSG_OOB;
 989                         goto copy;
 990                 }
 991                 if (flags & MSG_OOB)
 992                         return -EINVAL;
 993         }
 994
 995         skb = skb_recv_datagram(sk, flags, noblock, &err);
 996         lock_sock(sk);
 997         if (skb == NULL) {
 998                 if (err == -ENOTCONN && sk->sk_state == TCP_CLOSE_WAIT)
 999                         err = -ECONNRESET;
1000                 release_sock(sk);
1001                 return err;
1002         }
1003
1004         if (sk->sk_state == TCP_ESTABLISHED)
1005                 pipe_grant_credits(sk);
1006         release_sock(sk);
1007 copy:
1008         msg->msg_flags |= MSG_EOR;
1009         if (skb->len > len)
1010                 msg->msg_flags |= MSG_TRUNC;
1011         else
1012                 len = skb->len;
1013
1014         err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, len);
1015         if (!err)
1016                 err = (flags & MSG_TRUNC) ? skb->len : len;
1017
1018         skb_free_datagram(sk, skb);
1019         return err;
1020 }
1021
1022 static void pep_sock_unhash(struct sock *sk)
1023 {
1024         struct pep_sock *pn = pep_sk(sk);
1025         struct sock *skparent = NULL;
1026
1027         lock_sock(sk);
1028         if ((1 << sk->sk_state) & ~(TCPF_CLOSE|TCPF_LISTEN)) {
1029                 skparent = pn->listener;
1030                 sk_del_node_init(sk);
1031                 release_sock(sk);
1032
1033                 sk = skparent;
1034                 pn = pep_sk(skparent);
1035                 lock_sock(sk);
1036         }
1037         /* Unhash a listening sock only when it is closed
1038          * and all of its active connected pipes are closed. */
1039         if (hlist_empty(&pn->hlist))
1040                 pn_sock_unhash(&pn->pn_sk.sk);
1041         release_sock(sk);
1042
1043         if (skparent)
1044                 sock_put(skparent);
1045 }
1046
1047 static struct proto pep_proto = {
1048         .close          = pep_sock_close,
1049         .accept         = pep_sock_accept,
1050         .ioctl          = pep_ioctl,
1051         .init           = pep_init,
1052         .setsockopt     = pep_setsockopt,
1053         .getsockopt     = pep_getsockopt,
1054         .sendmsg        = pep_sendmsg,
1055         .recvmsg        = pep_recvmsg,
1056         .backlog_rcv    = pep_do_rcv,
1057         .hash           = pn_sock_hash,
1058         .unhash         = pep_sock_unhash,
1059         .get_port       = pn_sock_get_port,
1060         .obj_size       = sizeof(struct pep_sock),
1061         .owner          = THIS_MODULE,
1062         .name           = "PNPIPE",
1063 };
1064
1065 static struct phonet_protocol pep_pn_proto = {
1066         .ops            = &phonet_stream_ops,
1067         .prot           = &pep_proto,
1068         .sock_type      = SOCK_SEQPACKET,
1069 };
1070
1071 static int __init pep_register(void)
1072 {
1073         return phonet_proto_register(PN_PROTO_PIPE, &pep_pn_proto);
1074 }
1075
1076 static void __exit pep_unregister(void)
1077 {
1078         phonet_proto_unregister(PN_PROTO_PIPE, &pep_pn_proto);
1079 }
1080
1081 module_init(pep_register);
1082 module_exit(pep_unregister);
1083 MODULE_AUTHOR("Remi Denis-Courmont, Nokia");
1084 MODULE_DESCRIPTION("Phonet pipe protocol");
1085 MODULE_LICENSE("GPL");
1086 MODULE_ALIAS_NET_PF_PROTO(PF_PHONET, PN_PROTO_PIPE);