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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 #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 = pnp_hdr(skb);
 228
 229         if (!pskb_may_pull(skb, sizeof(*hdr) + 4))
 230                 return -EINVAL;
 231
 232         if (hdr->data[0] != PN_PEP_TYPE_COMMON) {
 233                 LIMIT_NETDEBUG(KERN_DEBUG"Phonet unknown PEP type: %u\n",
 234                                 (unsigned)hdr->data[0]);
 235                 return -EOPNOTSUPP;
 236         }
 237
 238         switch (hdr->data[1]) {
 239         case PN_PEP_IND_FLOW_CONTROL:
 240                 switch (pn->tx_fc) {
 241                 case PN_LEGACY_FLOW_CONTROL:
 242                         switch (hdr->data[4]) {
 243                         case PEP_IND_BUSY:
 244                                 pn->tx_credits = 0;
 245                                 break;
 246                         case PEP_IND_READY:
 247                                 pn->tx_credits = 1;
 248                                 break;
 249                         }
 250                         break;
 251                 case PN_ONE_CREDIT_FLOW_CONTROL:
 252                         if (hdr->data[4] == PEP_IND_READY)
 253                                 pn->tx_credits = 1;
 254                         break;
 255                 }
 256                 break;
 257
 258         case PN_PEP_IND_ID_MCFC_GRANT_CREDITS:
 259                 if (pn->tx_fc != PN_MULTI_CREDIT_FLOW_CONTROL)
 260                         break;
 261                 if (pn->tx_credits + hdr->data[4] > 0xff)
 262                         pn->tx_credits = 0xff;
 263                 else
 264                         pn->tx_credits += hdr->data[4];
 265                 break;
 266
 267         default:
 268                 LIMIT_NETDEBUG(KERN_DEBUG"Phonet unknown PEP indication: %u\n",
 269                                 (unsigned)hdr->data[1]);
 270                 return -EOPNOTSUPP;
 271         }
 272         if (pn->tx_credits)
 273                 sk->sk_write_space(sk);
 274         return 0;
 275 }
 276
 277 static int pipe_rcv_created(struct sock *sk, struct sk_buff *skb)
 278 {
 279         struct pep_sock *pn = pep_sk(sk);
 280         struct pnpipehdr *hdr = pnp_hdr(skb);
 281         u8 n_sb = hdr->data[0];
 282
 283         pn->rx_fc = pn->tx_fc = PN_LEGACY_FLOW_CONTROL;
 284         __skb_pull(skb, sizeof(*hdr));
 285         while (n_sb > 0) {
 286                 u8 type, buf[2], len = sizeof(buf);
 287                 u8 *data = pep_get_sb(skb, &type, &len, buf);
 288
 289                 if (data == NULL)
 290                         return -EINVAL;
 291                 switch (type) {
 292                 case PN_PIPE_SB_NEGOTIATED_FC:
 293                         if (len < 2 || (data[0] | data[1]) > 3)
 294                                 break;
 295                         pn->tx_fc = data[0] & 3;
 296                         pn->rx_fc = data[1] & 3;
 297                         break;
 298                 }
 299                 n_sb--;
 300         }
 301         return 0;
 302 }
 303
 304 /* Queue an skb to a connected sock.
 305  * Socket lock must be held. */
 306 static int pipe_do_rcv(struct sock *sk, struct sk_buff *skb)
 307 {
 308         struct pep_sock *pn = pep_sk(sk);
 309         struct pnpipehdr *hdr = pnp_hdr(skb);
 310         struct sk_buff_head *queue;
 311         int err = 0;
 312
 313         BUG_ON(sk->sk_state == TCP_CLOSE_WAIT);
 314
 315         switch (hdr->message_id) {
 316         case PNS_PEP_CONNECT_REQ:
 317                 pep_reject_conn(sk, skb, PN_PIPE_ERR_PEP_IN_USE);
 318                 break;
 319
 320         case PNS_PEP_DISCONNECT_REQ:
 321                 pep_reply(sk, skb, PN_PIPE_NO_ERROR, NULL, 0, GFP_ATOMIC);
 322                 sk->sk_state = TCP_CLOSE_WAIT;
 323                 if (!sock_flag(sk, SOCK_DEAD))
 324                         sk->sk_state_change(sk);
 325                 break;
 326
 327         case PNS_PEP_ENABLE_REQ:
 328                 /* Wait for PNS_PIPE_(ENABLED|REDIRECTED)_IND */
 329                 pep_reply(sk, skb, PN_PIPE_NO_ERROR, NULL, 0, GFP_ATOMIC);
 330                 break;
 331
 332         case PNS_PEP_RESET_REQ:
 333                 switch (hdr->state_after_reset) {
 334                 case PN_PIPE_DISABLE:
 335                         pn->init_enable = 0;
 336                         break;
 337                 case PN_PIPE_ENABLE:
 338                         pn->init_enable = 1;
 339                         break;
 340                 default: /* not allowed to send an error here!? */
 341                         err = -EINVAL;
 342                         goto out;
 343                 }
 344                 /* fall through */
 345         case PNS_PEP_DISABLE_REQ:
 346                 pn->tx_credits = 0;
 347                 pep_reply(sk, skb, PN_PIPE_NO_ERROR, NULL, 0, GFP_ATOMIC);
 348                 break;
 349
 350         case PNS_PEP_CTRL_REQ:
 351                 if (skb_queue_len(&pn->ctrlreq_queue) >= PNPIPE_CTRLREQ_MAX)
 352                         break;
 353                 __skb_pull(skb, 4);
 354                 queue = &pn->ctrlreq_queue;
 355                 goto queue;
 356
 357         case PNS_PIPE_DATA:
 358                 __skb_pull(skb, 3); /* Pipe data header */
 359                 if (!pn_flow_safe(pn->rx_fc)) {
 360                         err = sock_queue_rcv_skb(sk, skb);
 361                         if (!err)
 362                                 return 0;
 363                         break;
 364                 }
 365
 366                 if (pn->rx_credits == 0) {
 367                         err = -ENOBUFS;
 368                         break;
 369                 }
 370                 pn->rx_credits--;
 371                 queue = &sk->sk_receive_queue;
 372                 goto queue;
 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 queue:
 417         skb->dev = NULL;
 418         skb_set_owner_r(skb, sk);
 419         err = skb->len;
 420         skb_queue_tail(queue, skb);
 421         if (!sock_flag(sk, SOCK_DEAD))
 422                 sk->sk_data_ready(sk, err);
 423         return 0;
 424 }
 425
 426 /* Destroy connected sock. */
 427 static void pipe_destruct(struct sock *sk)
 428 {
 429         struct pep_sock *pn = pep_sk(sk);
 430
 431         skb_queue_purge(&sk->sk_receive_queue);
 432         skb_queue_purge(&pn->ctrlreq_queue);
 433 }
 434
 435 static int pep_connreq_rcv(struct sock *sk, struct sk_buff *skb)
 436 {
 437         struct sock *newsk;
 438         struct pep_sock *newpn, *pn = pep_sk(sk);
 439         struct pnpipehdr *hdr;
 440         struct sockaddr_pn dst;
 441         u16 peer_type;
 442         u8 pipe_handle, enabled, n_sb;
 443
 444         if (!pskb_pull(skb, sizeof(*hdr) + 4))
 445                 return -EINVAL;
 446
 447         hdr = pnp_hdr(skb);
 448         pipe_handle = hdr->pipe_handle;
 449         switch (hdr->state_after_connect) {
 450         case PN_PIPE_DISABLE:
 451                 enabled = 0;
 452                 break;
 453         case PN_PIPE_ENABLE:
 454                 enabled = 1;
 455                 break;
 456         default:
 457                 pep_reject_conn(sk, skb, PN_PIPE_ERR_INVALID_PARAM);
 458                 return -EINVAL;
 459         }
 460         peer_type = hdr->other_pep_type << 8;
 461
 462         if (unlikely(sk->sk_state != TCP_LISTEN) || sk_acceptq_is_full(sk)) {
 463                 pep_reject_conn(sk, skb, PN_PIPE_ERR_PEP_IN_USE);
 464                 return -ENOBUFS;
 465         }
 466
 467         /* Parse sub-blocks (options) */
 468         n_sb = hdr->data[4];
 469         while (n_sb > 0) {
 470                 u8 type, buf[1], len = sizeof(buf);
 471                 const u8 *data = pep_get_sb(skb, &type, &len, buf);
 472
 473                 if (data == NULL)
 474                         return -EINVAL;
 475                 switch (type) {
 476                 case PN_PIPE_SB_CONNECT_REQ_PEP_SUB_TYPE:
 477                         if (len < 1)
 478                                 return -EINVAL;
 479                         peer_type = (peer_type & 0xff00) | data[0];
 480                         break;
 481                 }
 482                 n_sb--;
 483         }
 484
 485         skb = skb_clone(skb, GFP_ATOMIC);
 486         if (!skb)
 487                 return -ENOMEM;
 488
 489         /* Create a new to-be-accepted sock */
 490         newsk = sk_alloc(sock_net(sk), PF_PHONET, GFP_ATOMIC, sk->sk_prot);
 491         if (!newsk) {
 492                 kfree_skb(skb);
 493                 return -ENOMEM;
 494         }
 495         sock_init_data(NULL, newsk);
 496         newsk->sk_state = TCP_SYN_RECV;
 497         newsk->sk_backlog_rcv = pipe_do_rcv;
 498         newsk->sk_protocol = sk->sk_protocol;
 499         newsk->sk_destruct = pipe_destruct;
 500
 501         newpn = pep_sk(newsk);
 502         pn_skb_get_dst_sockaddr(skb, &dst);
 503         newpn->pn_sk.sobject = pn_sockaddr_get_object(&dst);
 504         newpn->pn_sk.resource = pn->pn_sk.resource;
 505         skb_queue_head_init(&newpn->ctrlreq_queue);
 506         newpn->pipe_handle = pipe_handle;
 507         newpn->peer_type = peer_type;
 508         newpn->rx_credits = newpn->tx_credits = 0;
 509         newpn->rx_fc = newpn->tx_fc = PN_LEGACY_FLOW_CONTROL;
 510         newpn->init_enable = enabled;
 511
 512         BUG_ON(!skb_queue_empty(&newsk->sk_receive_queue));
 513         skb_queue_head(&newsk->sk_receive_queue, skb);
 514         if (!sock_flag(sk, SOCK_DEAD))
 515                 sk->sk_data_ready(sk, 0);
 516
 517         sk_acceptq_added(sk);
 518         sk_add_node(newsk, &pn->ackq);
 519         return 0;
 520 }
 521
 522 /* Listening sock must be locked */
 523 static struct sock *pep_find_pipe(const struct hlist_head *hlist,
 524                                         const struct sockaddr_pn *dst,
 525                                         u8 pipe_handle)
 526 {
 527         struct hlist_node *node;
 528         struct sock *sknode;
 529         u16 dobj = pn_sockaddr_get_object(dst);
 530
 531         sk_for_each(sknode, node, hlist) {
 532                 struct pep_sock *pnnode = pep_sk(sknode);
 533
 534                 /* Ports match, but addresses might not: */
 535                 if (pnnode->pn_sk.sobject != dobj)
 536                         continue;
 537                 if (pnnode->pipe_handle != pipe_handle)
 538                         continue;
 539                 if (sknode->sk_state == TCP_CLOSE_WAIT)
 540                         continue;
 541
 542                 sock_hold(sknode);
 543                 return sknode;
 544         }
 545         return NULL;
 546 }
 547
 548 /*
 549  * Deliver an skb to a listening sock.
 550  * Socket lock must be held.
 551  * We then queue the skb to the right connected sock (if any).
 552  */
 553 static int pep_do_rcv(struct sock *sk, struct sk_buff *skb)
 554 {
 555         struct pep_sock *pn = pep_sk(sk);
 556         struct sock *sknode;
 557         struct pnpipehdr *hdr = pnp_hdr(skb);
 558         struct sockaddr_pn dst;
 559         int err = NET_RX_SUCCESS;
 560         u8 pipe_handle;
 561
 562         if (!pskb_may_pull(skb, sizeof(*hdr)))
 563                 goto drop;
 564
 565         hdr = pnp_hdr(skb);
 566         pipe_handle = hdr->pipe_handle;
 567         if (pipe_handle == PN_PIPE_INVALID_HANDLE)
 568                 goto drop;
 569
 570         pn_skb_get_dst_sockaddr(skb, &dst);
 571
 572         /* Look for an existing pipe handle */
 573         sknode = pep_find_pipe(&pn->hlist, &dst, pipe_handle);
 574         if (sknode)
 575                 return sk_receive_skb(sknode, skb, 1);
 576
 577         /* Look for a pipe handle pending accept */
 578         sknode = pep_find_pipe(&pn->ackq, &dst, pipe_handle);
 579         if (sknode) {
 580                 sock_put(sknode);
 581                 if (net_ratelimit())
 582                         printk(KERN_WARNING"Phonet unconnected PEP ignored");
 583                 err = NET_RX_DROP;
 584                 goto drop;
 585         }
 586
 587         switch (hdr->message_id) {
 588         case PNS_PEP_CONNECT_REQ:
 589                 err = pep_connreq_rcv(sk, skb);
 590                 break;
 591
 592         case PNS_PEP_DISCONNECT_REQ:
 593                 pep_reply(sk, skb, PN_PIPE_NO_ERROR, NULL, 0, GFP_ATOMIC);
 594                 break;
 595
 596         case PNS_PEP_CTRL_REQ:
 597                 pep_ctrlreq_error(sk, skb, PN_PIPE_INVALID_HANDLE, GFP_ATOMIC);
 598                 break;
 599
 600         case PNS_PEP_RESET_REQ:
 601         case PNS_PEP_ENABLE_REQ:
 602         case PNS_PEP_DISABLE_REQ:
 603                 /* invalid handle is not even allowed here! */
 604         default:
 605                 err = NET_RX_DROP;
 606         }
 607 drop:
 608         kfree_skb(skb);
 609         return err;
 610 }
 611
 612 /* associated socket ceases to exist */
 613 static void pep_sock_close(struct sock *sk, long timeout)
 614 {
 615         struct pep_sock *pn = pep_sk(sk);
 616         int ifindex = 0;
 617
 618         sk_common_release(sk);
 619
 620         lock_sock(sk);
 621         if (sk->sk_state == TCP_LISTEN) {
 622                 /* Destroy the listen queue */
 623                 struct sock *sknode;
 624                 struct hlist_node *p, *n;
 625
 626                 sk_for_each_safe(sknode, p, n, &pn->ackq)
 627                         sk_del_node_init(sknode);
 628                 sk->sk_state = TCP_CLOSE;
 629         }
 630         ifindex = pn->ifindex;
 631         pn->ifindex = 0;
 632         release_sock(sk);
 633
 634         if (ifindex)
 635                 gprs_detach(sk);
 636 }
 637
 638 static int pep_wait_connreq(struct sock *sk, int noblock)
 639 {
 640         struct task_struct *tsk = current;
 641         struct pep_sock *pn = pep_sk(sk);
 642         long timeo = sock_rcvtimeo(sk, noblock);
 643
 644         for (;;) {
 645                 DEFINE_WAIT(wait);
 646
 647                 if (sk->sk_state != TCP_LISTEN)
 648                         return -EINVAL;
 649                 if (!hlist_empty(&pn->ackq))
 650                         break;
 651                 if (!timeo)
 652                         return -EWOULDBLOCK;
 653                 if (signal_pending(tsk))
 654                         return sock_intr_errno(timeo);
 655
 656                 prepare_to_wait_exclusive(&sk->sk_socket->wait, &wait,
 657                                                 TASK_INTERRUPTIBLE);
 658                 release_sock(sk);
 659                 timeo = schedule_timeout(timeo);
 660                 lock_sock(sk);
 661                 finish_wait(&sk->sk_socket->wait, &wait);
 662         }
 663
 664         return 0;
 665 }
 666
 667 static struct sock *pep_sock_accept(struct sock *sk, int flags, int *errp)
 668 {
 669         struct pep_sock *pn = pep_sk(sk);
 670         struct sock *newsk = NULL;
 671         struct sk_buff *oskb;
 672         int err;
 673
 674         lock_sock(sk);
 675         err = pep_wait_connreq(sk, flags & O_NONBLOCK);
 676         if (err)
 677                 goto out;
 678
 679         newsk = __sk_head(&pn->ackq);
 680
 681         oskb = skb_dequeue(&newsk->sk_receive_queue);
 682         err = pep_accept_conn(newsk, oskb);
 683         if (err) {
 684                 skb_queue_head(&newsk->sk_receive_queue, oskb);
 685                 newsk = NULL;
 686                 goto out;
 687         }
 688
 689         sock_hold(sk);
 690         pep_sk(newsk)->listener = sk;
 691
 692         sock_hold(newsk);
 693         sk_del_node_init(newsk);
 694         sk_acceptq_removed(sk);
 695         sk_add_node(newsk, &pn->hlist);
 696         __sock_put(newsk);
 697
 698 out:
 699         release_sock(sk);
 700         *errp = err;
 701         return newsk;
 702 }
 703
 704 static int pep_ioctl(struct sock *sk, int cmd, unsigned long arg)
 705 {
 706         struct pep_sock *pn = pep_sk(sk);
 707         int answ;
 708
 709         switch (cmd) {
 710         case SIOCINQ:
 711                 if (sk->sk_state == TCP_LISTEN)
 712                         return -EINVAL;
 713
 714                 lock_sock(sk);
 715                 if (sock_flag(sk, SOCK_URGINLINE)
 716                  && !skb_queue_empty(&pn->ctrlreq_queue))
 717                         answ = skb_peek(&pn->ctrlreq_queue)->len;
 718                 else if (!skb_queue_empty(&sk->sk_receive_queue))
 719                         answ = skb_peek(&sk->sk_receive_queue)->len;
 720                 else
 721                         answ = 0;
 722                 release_sock(sk);
 723                 return put_user(answ, (int __user *)arg);
 724         }
 725
 726         return -ENOIOCTLCMD;
 727 }
 728
 729 static int pep_init(struct sock *sk)
 730 {
 731         struct pep_sock *pn = pep_sk(sk);
 732
 733         INIT_HLIST_HEAD(&pn->ackq);
 734         INIT_HLIST_HEAD(&pn->hlist);
 735         skb_queue_head_init(&pn->ctrlreq_queue);
 736         pn->pipe_handle = PN_PIPE_INVALID_HANDLE;
 737         return 0;
 738 }
 739
 740 static int pep_setsockopt(struct sock *sk, int level, int optname,
 741                                 char __user *optval, int optlen)
 742 {
 743         struct pep_sock *pn = pep_sk(sk);
 744         int val = 0, err = 0;
 745
 746         if (level != SOL_PNPIPE)
 747                 return -ENOPROTOOPT;
 748         if (optlen >= sizeof(int)) {
 749                 if (get_user(val, (int __user *) optval))
 750                         return -EFAULT;
 751         }
 752
 753         lock_sock(sk);
 754         switch (optname) {
 755         case PNPIPE_ENCAP:
 756                 if (val && val != PNPIPE_ENCAP_IP) {
 757                         err = -EINVAL;
 758                         break;
 759                 }
 760                 if (!pn->ifindex == !val)
 761                         break; /* Nothing to do! */
 762                 if (!capable(CAP_NET_ADMIN)) {
 763                         err = -EPERM;
 764                         break;
 765                 }
 766                 if (val) {
 767                         release_sock(sk);
 768                         err = gprs_attach(sk);
 769                         if (err > 0) {
 770                                 pn->ifindex = err;
 771                                 err = 0;
 772                         }
 773                 } else {
 774                         pn->ifindex = 0;
 775                         release_sock(sk);
 776                         gprs_detach(sk);
 777                         err = 0;
 778                 }
 779                 goto out_norel;
 780         default:
 781                 err = -ENOPROTOOPT;
 782         }
 783         release_sock(sk);
 784
 785 out_norel:
 786         return err;
 787 }
 788
 789 static int pep_getsockopt(struct sock *sk, int level, int optname,
 790                                 char __user *optval, int __user *optlen)
 791 {
 792         struct pep_sock *pn = pep_sk(sk);
 793         int len, val;
 794
 795         if (level != SOL_PNPIPE)
 796                 return -ENOPROTOOPT;
 797         if (get_user(len, optlen))
 798                 return -EFAULT;
 799
 800         switch (optname) {
 801         case PNPIPE_ENCAP:
 802                 val = pn->ifindex ? PNPIPE_ENCAP_IP : PNPIPE_ENCAP_NONE;
 803                 break;
 804         case PNPIPE_IFINDEX:
 805                 val = pn->ifindex;
 806                 break;
 807         default:
 808                 return -ENOPROTOOPT;
 809         }
 810
 811         len = min_t(unsigned int, sizeof(int), len);
 812         if (put_user(len, optlen))
 813                 return -EFAULT;
 814         if (put_user(val, (int __user *) optval))
 815                 return -EFAULT;
 816         return 0;
 817 }
 818
 819 static int pipe_skb_send(struct sock *sk, struct sk_buff *skb)
 820 {
 821         struct pep_sock *pn = pep_sk(sk);
 822         struct pnpipehdr *ph;
 823
 824         skb_push(skb, 3);
 825         skb_reset_transport_header(skb);
 826         ph = pnp_hdr(skb);
 827         ph->utid = 0;
 828         ph->message_id = PNS_PIPE_DATA;
 829         ph->pipe_handle = pn->pipe_handle;
 830         if (pn_flow_safe(pn->tx_fc) && pn->tx_credits)
 831                 pn->tx_credits--;
 832
 833         return pn_skb_send(sk, skb, &pipe_srv);
 834 }
 835
 836 static int pep_sendmsg(struct kiocb *iocb, struct sock *sk,
 837                         struct msghdr *msg, size_t len)
 838 {
 839         struct pep_sock *pn = pep_sk(sk);
 840         struct sk_buff *skb = NULL;
 841         long timeo;
 842         int flags = msg->msg_flags;
 843         int err, done;
 844
 845         if (msg->msg_flags & MSG_OOB || !(msg->msg_flags & MSG_EOR))
 846                 return -EOPNOTSUPP;
 847
 848         lock_sock(sk);
 849         timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT);
 850         if ((1 << sk->sk_state) & (TCPF_LISTEN|TCPF_CLOSE)) {
 851                 err = -ENOTCONN;
 852                 goto out;
 853         }
 854         if (sk->sk_state != TCP_ESTABLISHED) {
 855                 /* Wait until the pipe gets to enabled state */
 856 disabled:
 857                 err = sk_stream_wait_connect(sk, &timeo);
 858                 if (err)
 859                         goto out;
 860
 861                 if (sk->sk_state == TCP_CLOSE_WAIT) {
 862                         err = -ECONNRESET;
 863                         goto out;
 864                 }
 865         }
 866         BUG_ON(sk->sk_state != TCP_ESTABLISHED);
 867
 868         /* Wait until flow control allows TX */
 869         done = pn->tx_credits > 0;
 870         while (!done) {
 871                 DEFINE_WAIT(wait);
 872
 873                 if (!timeo) {
 874                         err = -EAGAIN;
 875                         goto out;
 876                 }
 877                 if (signal_pending(current)) {
 878                         err = sock_intr_errno(timeo);
 879                         goto out;
 880                 }
 881
 882                 prepare_to_wait(&sk->sk_socket->wait, &wait,
 883                                 TASK_INTERRUPTIBLE);
 884                 done = sk_wait_event(sk, &timeo, pn->tx_credits > 0);
 885                 finish_wait(&sk->sk_socket->wait, &wait);
 886
 887                 if (sk->sk_state != TCP_ESTABLISHED)
 888                         goto disabled;
 889         }
 890
 891         if (!skb) {
 892                 skb = sock_alloc_send_skb(sk, MAX_PNPIPE_HEADER + len,
 893                                                 flags & MSG_DONTWAIT, &err);
 894                 if (skb == NULL)
 895                         goto out;
 896                 skb_reserve(skb, MAX_PHONET_HEADER + 3);
 897
 898                 if (sk->sk_state != TCP_ESTABLISHED || !pn->tx_credits)
 899                         goto disabled; /* sock_alloc_send_skb might sleep */
 900         }
 901
 902         err = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len);
 903         if (err < 0)
 904                 goto out;
 905
 906         err = pipe_skb_send(sk, skb);
 907         if (err >= 0)
 908                 err = len; /* success! */
 909         skb = NULL;
 910 out:
 911         release_sock(sk);
 912         kfree_skb(skb);
 913         return err;
 914 }
 915
 916 int pep_writeable(struct sock *sk)
 917 {
 918         struct pep_sock *pn = pep_sk(sk);
 919
 920         return (sk->sk_state == TCP_ESTABLISHED) ? pn->tx_credits : 0;
 921 }
 922
 923 int pep_write(struct sock *sk, struct sk_buff *skb)
 924 {
 925         struct sk_buff *rskb, *fs;
 926         int flen = 0;
 927
 928         rskb = alloc_skb(MAX_PNPIPE_HEADER, GFP_ATOMIC);
 929         if (!rskb) {
 930                 kfree_skb(skb);
 931                 return -ENOMEM;
 932         }
 933         skb_shinfo(rskb)->frag_list = skb;
 934         rskb->len += skb->len;
 935         rskb->data_len += rskb->len;
 936         rskb->truesize += rskb->len;
 937
 938         /* Avoid nested fragments */
 939         for (fs = skb_shinfo(skb)->frag_list; fs; fs = fs->next)
 940                 flen += fs->len;
 941         skb->next = skb_shinfo(skb)->frag_list;
 942         skb_shinfo(skb)->frag_list = NULL;
 943         skb->len -= flen;
 944         skb->data_len -= flen;
 945         skb->truesize -= flen;
 946
 947         skb_reserve(rskb, MAX_PHONET_HEADER + 3);
 948         return pipe_skb_send(sk, rskb);
 949 }
 950
 951 struct sk_buff *pep_read(struct sock *sk)
 952 {
 953         struct sk_buff *skb = skb_dequeue(&sk->sk_receive_queue);
 954
 955         if (sk->sk_state == TCP_ESTABLISHED)
 956                 pipe_grant_credits(sk);
 957         return skb;
 958 }
 959
 960 static int pep_recvmsg(struct kiocb *iocb, struct sock *sk,
 961                         struct msghdr *msg, size_t len, int noblock,
 962                         int flags, int *addr_len)
 963 {
 964         struct sk_buff *skb;
 965         int err;
 966
 967         if (unlikely(1 << sk->sk_state & (TCPF_LISTEN | TCPF_CLOSE)))
 968                 return -ENOTCONN;
 969
 970         if ((flags & MSG_OOB) || sock_flag(sk, SOCK_URGINLINE)) {
 971                 /* Dequeue and acknowledge control request */
 972                 struct pep_sock *pn = pep_sk(sk);
 973
 974                 skb = skb_dequeue(&pn->ctrlreq_queue);
 975                 if (skb) {
 976                         pep_ctrlreq_error(sk, skb, PN_PIPE_NO_ERROR,
 977                                                 GFP_KERNEL);
 978                         msg->msg_flags |= MSG_OOB;
 979                         goto copy;
 980                 }
 981                 if (flags & MSG_OOB)
 982                         return -EINVAL;
 983         }
 984
 985         skb = skb_recv_datagram(sk, flags, noblock, &err);
 986         lock_sock(sk);
 987         if (skb == NULL) {
 988                 if (err == -ENOTCONN && sk->sk_state == TCP_CLOSE_WAIT)
 989                         err = -ECONNRESET;
 990                 release_sock(sk);
 991                 return err;
 992         }
 993
 994         if (sk->sk_state == TCP_ESTABLISHED)
 995                 pipe_grant_credits(sk);
 996         release_sock(sk);
 997 copy:
 998         msg->msg_flags |= MSG_EOR;
 999         if (skb->len > len)
1000                 msg->msg_flags |= MSG_TRUNC;
1001         else
1002                 len = skb->len;
1003
1004         err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, len);
1005         if (!err)
1006                 err = (flags & MSG_TRUNC) ? skb->len : len;
1007
1008         skb_free_datagram(sk, skb);
1009         return err;
1010 }
1011
1012 static void pep_sock_unhash(struct sock *sk)
1013 {
1014         struct pep_sock *pn = pep_sk(sk);
1015         struct sock *skparent = NULL;
1016
1017         lock_sock(sk);
1018         if ((1 << sk->sk_state) & ~(TCPF_CLOSE|TCPF_LISTEN)) {
1019                 skparent = pn->listener;
1020                 sk_del_node_init(sk);
1021                 release_sock(sk);
1022
1023                 sk = skparent;
1024                 pn = pep_sk(skparent);
1025                 lock_sock(sk);
1026         }
1027         /* Unhash a listening sock only when it is closed
1028          * and all of its active connected pipes are closed. */
1029         if (hlist_empty(&pn->hlist))
1030                 pn_sock_unhash(&pn->pn_sk.sk);
1031         release_sock(sk);
1032
1033         if (skparent)
1034                 sock_put(skparent);
1035 }
1036
1037 static struct proto pep_proto = {
1038         .close          = pep_sock_close,
1039         .accept         = pep_sock_accept,
1040         .ioctl          = pep_ioctl,
1041         .init           = pep_init,
1042         .setsockopt     = pep_setsockopt,
1043         .getsockopt     = pep_getsockopt,
1044         .sendmsg        = pep_sendmsg,
1045         .recvmsg        = pep_recvmsg,
1046         .backlog_rcv    = pep_do_rcv,
1047         .hash           = pn_sock_hash,
1048         .unhash         = pep_sock_unhash,
1049         .get_port       = pn_sock_get_port,
1050         .obj_size       = sizeof(struct pep_sock),
1051         .owner          = THIS_MODULE,
1052         .name           = "PNPIPE",
1053 };
1054
1055 static struct phonet_protocol pep_pn_proto = {
1056         .ops            = &phonet_stream_ops,
1057         .prot           = &pep_proto,
1058         .sock_type      = SOCK_SEQPACKET,
1059 };
1060
1061 static int __init pep_register(void)
1062 {
1063         return phonet_proto_register(PN_PROTO_PIPE, &pep_pn_proto);
1064 }
1065
1066 static void __exit pep_unregister(void)
1067 {
1068         phonet_proto_unregister(PN_PROTO_PIPE, &pep_pn_proto);
1069 }
1070
1071 module_init(pep_register);
1072 module_exit(pep_unregister);
1073 MODULE_AUTHOR("Remi Denis-Courmont, Nokia");
1074 MODULE_DESCRIPTION("Phonet pipe protocol");
1075 MODULE_LICENSE("GPL");
1076 MODULE_ALIAS_NET_PF_PROTO(PF_PHONET, PN_PROTO_PIPE);