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/slab.h>
  27 #include <linux/socket.h>
  28 #include <net/sock.h>
  29 #include <net/tcp_states.h>
  30 #include <asm/ioctls.h>
  31
  32 #include <linux/phonet.h>
  33 #include <net/phonet/phonet.h>
  34 #include <net/phonet/pep.h>
  35 #include <net/phonet/gprs.h>
  36
  37 /* sk_state values:
  38  * TCP_CLOSE            sock not in use yet
  39  * TCP_CLOSE_WAIT       disconnected pipe
  40  * TCP_LISTEN           listening pipe endpoint
  41  * TCP_SYN_RECV         connected pipe in disabled state
  42  * TCP_ESTABLISHED      connected pipe in enabled state
  43  *
  44  * pep_sock locking:
  45  *  - sk_state, ackq, hlist: sock lock needed
  46  *  - listener: read only
  47  *  - pipe_handle: read only
  48  */
  49
  50 #define CREDITS_MAX     10
  51 #define CREDITS_THR     7
  52
  53 static const struct sockaddr_pn pipe_srv = {
  54         .spn_family = AF_PHONET,
  55         .spn_resource = 0xD9, /* pipe service */
  56 };
  57
  58 #define pep_sb_size(s) (((s) + 5) & ~3) /* 2-bytes head, 32-bits aligned */
  59
  60 /* Get the next TLV sub-block. */
  61 static unsigned char *pep_get_sb(struct sk_buff *skb, u8 *ptype, u8 *plen,
  62                                         void *buf)
  63 {
  64         void *data = NULL;
  65         struct {
  66                 u8 sb_type;
  67                 u8 sb_len;
  68         } *ph, h;
  69         int buflen = *plen;
  70
  71         ph = skb_header_pointer(skb, 0, 2, &h);
  72         if (ph == NULL || ph->sb_len < 2 || !pskb_may_pull(skb, ph->sb_len))
  73                 return NULL;
  74         ph->sb_len -= 2;
  75         *ptype = ph->sb_type;
  76         *plen = ph->sb_len;
  77
  78         if (buflen > ph->sb_len)
  79                 buflen = ph->sb_len;
  80         data = skb_header_pointer(skb, 2, buflen, buf);
  81         __skb_pull(skb, 2 + ph->sb_len);
  82         return data;
  83 }
  84
  85 static int pep_reply(struct sock *sk, struct sk_buff *oskb,
  86                         u8 code, const void *data, int len, gfp_t priority)
  87 {
  88         const struct pnpipehdr *oph = pnp_hdr(oskb);
  89         struct pnpipehdr *ph;
  90         struct sk_buff *skb;
  91
  92         skb = alloc_skb(MAX_PNPIPE_HEADER + len, priority);
  93         if (!skb)
  94                 return -ENOMEM;
  95         skb_set_owner_w(skb, sk);
  96
  97         skb_reserve(skb, MAX_PNPIPE_HEADER);
  98         __skb_put(skb, len);
  99         skb_copy_to_linear_data(skb, data, len);
 100         __skb_push(skb, sizeof(*ph));
 101         skb_reset_transport_header(skb);
 102         ph = pnp_hdr(skb);
 103         ph->utid = oph->utid;
 104         ph->message_id = oph->message_id + 1; /* REQ -> RESP */
 105         ph->pipe_handle = oph->pipe_handle;
 106         ph->error_code = code;
 107
 108         return pn_skb_send(sk, skb, &pipe_srv);
 109 }
 110
 111 #define PAD 0x00
 112 static int pep_accept_conn(struct sock *sk, struct sk_buff *skb)
 113 {
 114         static const u8 data[20] = {
 115                 PAD, PAD, PAD, 2 /* sub-blocks */,
 116                 PN_PIPE_SB_REQUIRED_FC_TX, pep_sb_size(5), 3, PAD,
 117                         PN_MULTI_CREDIT_FLOW_CONTROL,
 118                         PN_ONE_CREDIT_FLOW_CONTROL,
 119                         PN_LEGACY_FLOW_CONTROL,
 120                         PAD,
 121                 PN_PIPE_SB_PREFERRED_FC_RX, pep_sb_size(5), 3, PAD,
 122                         PN_MULTI_CREDIT_FLOW_CONTROL,
 123                         PN_ONE_CREDIT_FLOW_CONTROL,
 124                         PN_LEGACY_FLOW_CONTROL,
 125                         PAD,
 126         };
 127
 128         might_sleep();
 129         return pep_reply(sk, skb, PN_PIPE_NO_ERROR, data, sizeof(data),
 130                                 GFP_KERNEL);
 131 }
 132
 133 static int pep_reject_conn(struct sock *sk, struct sk_buff *skb, u8 code)
 134 {
 135         static const u8 data[4] = { PAD, PAD, PAD, 0 /* sub-blocks */ };
 136         WARN_ON(code == PN_PIPE_NO_ERROR);
 137         return pep_reply(sk, skb, code, data, sizeof(data), GFP_ATOMIC);
 138 }
 139
 140 /* Control requests are not sent by the pipe service and have a specific
 141  * message format. */
 142 static int pep_ctrlreq_error(struct sock *sk, struct sk_buff *oskb, u8 code,
 143                                 gfp_t priority)
 144 {
 145         const struct pnpipehdr *oph = pnp_hdr(oskb);
 146         struct sk_buff *skb;
 147         struct pnpipehdr *ph;
 148         struct sockaddr_pn dst;
 149
 150         skb = alloc_skb(MAX_PNPIPE_HEADER + 4, priority);
 151         if (!skb)
 152                 return -ENOMEM;
 153         skb_set_owner_w(skb, sk);
 154
 155         skb_reserve(skb, MAX_PHONET_HEADER);
 156         ph = (struct pnpipehdr *)skb_put(skb, sizeof(*ph) + 4);
 157
 158         ph->utid = oph->utid;
 159         ph->message_id = PNS_PEP_CTRL_RESP;
 160         ph->pipe_handle = oph->pipe_handle;
 161         ph->data[0] = oph->data[1]; /* CTRL id */
 162         ph->data[1] = oph->data[0]; /* PEP type */
 163         ph->data[2] = code; /* error code, at an usual offset */
 164         ph->data[3] = PAD;
 165         ph->data[4] = PAD;
 166
 167         pn_skb_get_src_sockaddr(oskb, &dst);
 168         return pn_skb_send(sk, skb, &dst);
 169 }
 170
 171 static int pipe_snd_status(struct sock *sk, u8 type, u8 status, gfp_t priority)
 172 {
 173         struct pep_sock *pn = pep_sk(sk);
 174         struct pnpipehdr *ph;
 175         struct sk_buff *skb;
 176
 177         skb = alloc_skb(MAX_PNPIPE_HEADER + 4, priority);
 178         if (!skb)
 179                 return -ENOMEM;
 180         skb_set_owner_w(skb, sk);
 181
 182         skb_reserve(skb, MAX_PNPIPE_HEADER + 4);
 183         __skb_push(skb, sizeof(*ph) + 4);
 184         skb_reset_transport_header(skb);
 185         ph = pnp_hdr(skb);
 186         ph->utid = 0;
 187         ph->message_id = PNS_PEP_STATUS_IND;
 188         ph->pipe_handle = pn->pipe_handle;
 189         ph->pep_type = PN_PEP_TYPE_COMMON;
 190         ph->data[1] = type;
 191         ph->data[2] = PAD;
 192         ph->data[3] = PAD;
 193         ph->data[4] = status;
 194
 195         return pn_skb_send(sk, skb, &pipe_srv);
 196 }
 197
 198 /* Send our RX flow control information to the sender.
 199  * Socket must be locked. */
 200 static void pipe_grant_credits(struct sock *sk)
 201 {
 202         struct pep_sock *pn = pep_sk(sk);
 203
 204         BUG_ON(sk->sk_state != TCP_ESTABLISHED);
 205
 206         switch (pn->rx_fc) {
 207         case PN_LEGACY_FLOW_CONTROL: /* TODO */
 208                 break;
 209         case PN_ONE_CREDIT_FLOW_CONTROL:
 210                 pipe_snd_status(sk, PN_PEP_IND_FLOW_CONTROL,
 211                                 PEP_IND_READY, GFP_ATOMIC);
 212                 pn->rx_credits = 1;
 213                 break;
 214         case PN_MULTI_CREDIT_FLOW_CONTROL:
 215                 if ((pn->rx_credits + CREDITS_THR) > CREDITS_MAX)
 216                         break;
 217                 if (pipe_snd_status(sk, PN_PEP_IND_ID_MCFC_GRANT_CREDITS,
 218                                         CREDITS_MAX - pn->rx_credits,
 219                                         GFP_ATOMIC) == 0)
 220                         pn->rx_credits = CREDITS_MAX;
 221                 break;
 222         }
 223 }
 224
 225 static int pipe_rcv_status(struct sock *sk, struct sk_buff *skb)
 226 {
 227         struct pep_sock *pn = pep_sk(sk);
 228         struct pnpipehdr *hdr;
 229         int wake = 0;
 230
 231         if (!pskb_may_pull(skb, sizeof(*hdr) + 4))
 232                 return -EINVAL;
 233
 234         hdr = pnp_hdr(skb);
 235         if (hdr->data[0] != PN_PEP_TYPE_COMMON) {
 236                 LIMIT_NETDEBUG(KERN_DEBUG"Phonet unknown PEP type: %u\n",
 237                                 (unsigned)hdr->data[0]);
 238                 return -EOPNOTSUPP;
 239         }
 240
 241         switch (hdr->data[1]) {
 242         case PN_PEP_IND_FLOW_CONTROL:
 243                 switch (pn->tx_fc) {
 244                 case PN_LEGACY_FLOW_CONTROL:
 245                         switch (hdr->data[4]) {
 246                         case PEP_IND_BUSY:
 247                                 atomic_set(&pn->tx_credits, 0);
 248                                 break;
 249                         case PEP_IND_READY:
 250                                 atomic_set(&pn->tx_credits, wake = 1);
 251                                 break;
 252                         }
 253                         break;
 254                 case PN_ONE_CREDIT_FLOW_CONTROL:
 255                         if (hdr->data[4] == PEP_IND_READY)
 256                                 atomic_set(&pn->tx_credits, wake = 1);
 257                         break;
 258                 }
 259                 break;
 260
 261         case PN_PEP_IND_ID_MCFC_GRANT_CREDITS:
 262                 if (pn->tx_fc != PN_MULTI_CREDIT_FLOW_CONTROL)
 263                         break;
 264                 atomic_add(wake = hdr->data[4], &pn->tx_credits);
 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 (wake)
 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                 atomic_set(&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                         atomic_inc(&sk->sk_drops);
 353                         break;
 354                 }
 355                 __skb_pull(skb, 4);
 356                 queue = &pn->ctrlreq_queue;
 357                 goto queue;
 358
 359         case PNS_PIPE_ALIGNED_DATA:
 360                 __skb_pull(skb, 1);
 361                 /* fall through */
 362         case PNS_PIPE_DATA:
 363                 __skb_pull(skb, 3); /* Pipe data header */
 364                 if (!pn_flow_safe(pn->rx_fc)) {
 365                         err = sock_queue_rcv_skb(sk, skb);
 366                         if (!err)
 367                                 return 0;
 368                         break;
 369                 }
 370
 371                 if (pn->rx_credits == 0) {
 372                         atomic_inc(&sk->sk_drops);
 373                         err = -ENOBUFS;
 374                         break;
 375                 }
 376                 pn->rx_credits--;
 377                 queue = &sk->sk_receive_queue;
 378                 goto queue;
 379
 380         case PNS_PEP_STATUS_IND:
 381                 pipe_rcv_status(sk, skb);
 382                 break;
 383
 384         case PNS_PIPE_REDIRECTED_IND:
 385                 err = pipe_rcv_created(sk, skb);
 386                 break;
 387
 388         case PNS_PIPE_CREATED_IND:
 389                 err = pipe_rcv_created(sk, skb);
 390                 if (err)
 391                         break;
 392                 /* fall through */
 393         case PNS_PIPE_RESET_IND:
 394                 if (!pn->init_enable)
 395                         break;
 396                 /* fall through */
 397         case PNS_PIPE_ENABLED_IND:
 398                 if (!pn_flow_safe(pn->tx_fc)) {
 399                         atomic_set(&pn->tx_credits, 1);
 400                         sk->sk_write_space(sk);
 401                 }
 402                 if (sk->sk_state == TCP_ESTABLISHED)
 403                         break; /* Nothing to do */
 404                 sk->sk_state = TCP_ESTABLISHED;
 405                 pipe_grant_credits(sk);
 406                 break;
 407
 408         case PNS_PIPE_DISABLED_IND:
 409                 sk->sk_state = TCP_SYN_RECV;
 410                 pn->rx_credits = 0;
 411                 break;
 412
 413         default:
 414                 LIMIT_NETDEBUG(KERN_DEBUG"Phonet unknown PEP message: %u\n",
 415                                 hdr->message_id);
 416                 err = -EINVAL;
 417         }
 418 out:
 419         kfree_skb(skb);
 420         return err;
 421
 422 queue:
 423         skb->dev = NULL;
 424         skb_set_owner_r(skb, sk);
 425         err = skb->len;
 426         skb_queue_tail(queue, skb);
 427         if (!sock_flag(sk, SOCK_DEAD))
 428                 sk->sk_data_ready(sk, err);
 429         return 0;
 430 }
 431
 432 /* Destroy connected sock. */
 433 static void pipe_destruct(struct sock *sk)
 434 {
 435         struct pep_sock *pn = pep_sk(sk);
 436
 437         skb_queue_purge(&sk->sk_receive_queue);
 438         skb_queue_purge(&pn->ctrlreq_queue);
 439 }
 440
 441 static int pep_connreq_rcv(struct sock *sk, struct sk_buff *skb)
 442 {
 443         struct sock *newsk;
 444         struct pep_sock *newpn, *pn = pep_sk(sk);
 445         struct pnpipehdr *hdr;
 446         struct sockaddr_pn dst;
 447         u16 peer_type;
 448         u8 pipe_handle, enabled, n_sb;
 449         u8 aligned = 0;
 450
 451         if (!pskb_pull(skb, sizeof(*hdr) + 4))
 452                 return -EINVAL;
 453
 454         hdr = pnp_hdr(skb);
 455         pipe_handle = hdr->pipe_handle;
 456         switch (hdr->state_after_connect) {
 457         case PN_PIPE_DISABLE:
 458                 enabled = 0;
 459                 break;
 460         case PN_PIPE_ENABLE:
 461                 enabled = 1;
 462                 break;
 463         default:
 464                 pep_reject_conn(sk, skb, PN_PIPE_ERR_INVALID_PARAM);
 465                 return -EINVAL;
 466         }
 467         peer_type = hdr->other_pep_type << 8;
 468
 469         if (unlikely(sk->sk_state != TCP_LISTEN) || sk_acceptq_is_full(sk)) {
 470                 pep_reject_conn(sk, skb, PN_PIPE_ERR_PEP_IN_USE);
 471                 return -ENOBUFS;
 472         }
 473
 474         /* Parse sub-blocks (options) */
 475         n_sb = hdr->data[4];
 476         while (n_sb > 0) {
 477                 u8 type, buf[1], len = sizeof(buf);
 478                 const u8 *data = pep_get_sb(skb, &type, &len, buf);
 479
 480                 if (data == NULL)
 481                         return -EINVAL;
 482                 switch (type) {
 483                 case PN_PIPE_SB_CONNECT_REQ_PEP_SUB_TYPE:
 484                         if (len < 1)
 485                                 return -EINVAL;
 486                         peer_type = (peer_type & 0xff00) | data[0];
 487                         break;
 488                 case PN_PIPE_SB_ALIGNED_DATA:
 489                         aligned = data[0] != 0;
 490                         break;
 491                 }
 492                 n_sb--;
 493         }
 494
 495         skb = skb_clone(skb, GFP_ATOMIC);
 496         if (!skb)
 497                 return -ENOMEM;
 498
 499         /* Create a new to-be-accepted sock */
 500         newsk = sk_alloc(sock_net(sk), PF_PHONET, GFP_ATOMIC, sk->sk_prot);
 501         if (!newsk) {
 502                 kfree_skb(skb);
 503                 return -ENOMEM;
 504         }
 505         sock_init_data(NULL, newsk);
 506         newsk->sk_state = TCP_SYN_RECV;
 507         newsk->sk_backlog_rcv = pipe_do_rcv;
 508         newsk->sk_protocol = sk->sk_protocol;
 509         newsk->sk_destruct = pipe_destruct;
 510
 511         newpn = pep_sk(newsk);
 512         pn_skb_get_dst_sockaddr(skb, &dst);
 513         newpn->pn_sk.sobject = pn_sockaddr_get_object(&dst);
 514         newpn->pn_sk.resource = pn->pn_sk.resource;
 515         skb_queue_head_init(&newpn->ctrlreq_queue);
 516         newpn->pipe_handle = pipe_handle;
 517         atomic_set(&newpn->tx_credits, 0);
 518         newpn->peer_type = peer_type;
 519         newpn->rx_credits = 0;
 520         newpn->rx_fc = newpn->tx_fc = PN_LEGACY_FLOW_CONTROL;
 521         newpn->init_enable = enabled;
 522         newpn->aligned = aligned;
 523
 524         BUG_ON(!skb_queue_empty(&newsk->sk_receive_queue));
 525         skb_queue_head(&newsk->sk_receive_queue, skb);
 526         if (!sock_flag(sk, SOCK_DEAD))
 527                 sk->sk_data_ready(sk, 0);
 528
 529         sk_acceptq_added(sk);
 530         sk_add_node(newsk, &pn->ackq);
 531         return 0;
 532 }
 533
 534 /* Listening sock must be locked */
 535 static struct sock *pep_find_pipe(const struct hlist_head *hlist,
 536                                         const struct sockaddr_pn *dst,
 537                                         u8 pipe_handle)
 538 {
 539         struct hlist_node *node;
 540         struct sock *sknode;
 541         u16 dobj = pn_sockaddr_get_object(dst);
 542
 543         sk_for_each(sknode, node, hlist) {
 544                 struct pep_sock *pnnode = pep_sk(sknode);
 545
 546                 /* Ports match, but addresses might not: */
 547                 if (pnnode->pn_sk.sobject != dobj)
 548                         continue;
 549                 if (pnnode->pipe_handle != pipe_handle)
 550                         continue;
 551                 if (sknode->sk_state == TCP_CLOSE_WAIT)
 552                         continue;
 553
 554                 sock_hold(sknode);
 555                 return sknode;
 556         }
 557         return NULL;
 558 }
 559
 560 /*
 561  * Deliver an skb to a listening sock.
 562  * Socket lock must be held.
 563  * We then queue the skb to the right connected sock (if any).
 564  */
 565 static int pep_do_rcv(struct sock *sk, struct sk_buff *skb)
 566 {
 567         struct pep_sock *pn = pep_sk(sk);
 568         struct sock *sknode;
 569         struct pnpipehdr *hdr;
 570         struct sockaddr_pn dst;
 571         int err = NET_RX_SUCCESS;
 572         u8 pipe_handle;
 573
 574         if (!pskb_may_pull(skb, sizeof(*hdr)))
 575                 goto drop;
 576
 577         hdr = pnp_hdr(skb);
 578         pipe_handle = hdr->pipe_handle;
 579         if (pipe_handle == PN_PIPE_INVALID_HANDLE)
 580                 goto drop;
 581
 582         pn_skb_get_dst_sockaddr(skb, &dst);
 583
 584         /* Look for an existing pipe handle */
 585         sknode = pep_find_pipe(&pn->hlist, &dst, pipe_handle);
 586         if (sknode)
 587                 return sk_receive_skb(sknode, skb, 1);
 588
 589         /* Look for a pipe handle pending accept */
 590         sknode = pep_find_pipe(&pn->ackq, &dst, pipe_handle);
 591         if (sknode) {
 592                 sock_put(sknode);
 593                 if (net_ratelimit())
 594                         printk(KERN_WARNING"Phonet unconnected PEP ignored");
 595                 err = NET_RX_DROP;
 596                 goto drop;
 597         }
 598
 599         switch (hdr->message_id) {
 600         case PNS_PEP_CONNECT_REQ:
 601                 err = pep_connreq_rcv(sk, skb);
 602                 break;
 603
 604         case PNS_PEP_DISCONNECT_REQ:
 605                 pep_reply(sk, skb, PN_PIPE_NO_ERROR, NULL, 0, GFP_ATOMIC);
 606                 break;
 607
 608         case PNS_PEP_CTRL_REQ:
 609                 pep_ctrlreq_error(sk, skb, PN_PIPE_INVALID_HANDLE, GFP_ATOMIC);
 610                 break;
 611
 612         case PNS_PEP_RESET_REQ:
 613         case PNS_PEP_ENABLE_REQ:
 614         case PNS_PEP_DISABLE_REQ:
 615                 /* invalid handle is not even allowed here! */
 616         default:
 617                 err = NET_RX_DROP;
 618         }
 619 drop:
 620         kfree_skb(skb);
 621         return err;
 622 }
 623
 624 /* associated socket ceases to exist */
 625 static void pep_sock_close(struct sock *sk, long timeout)
 626 {
 627         struct pep_sock *pn = pep_sk(sk);
 628         int ifindex = 0;
 629
 630         sock_hold(sk); /* keep a reference after sk_common_release() */
 631         sk_common_release(sk);
 632
 633         lock_sock(sk);
 634         if (sk->sk_state == TCP_LISTEN) {
 635                 /* Destroy the listen queue */
 636                 struct sock *sknode;
 637                 struct hlist_node *p, *n;
 638
 639                 sk_for_each_safe(sknode, p, n, &pn->ackq)
 640                         sk_del_node_init(sknode);
 641                 sk->sk_state = TCP_CLOSE;
 642         }
 643         ifindex = pn->ifindex;
 644         pn->ifindex = 0;
 645         release_sock(sk);
 646
 647         if (ifindex)
 648                 gprs_detach(sk);
 649         sock_put(sk);
 650 }
 651
 652 static int pep_wait_connreq(struct sock *sk, int noblock)
 653 {
 654         struct task_struct *tsk = current;
 655         struct pep_sock *pn = pep_sk(sk);
 656         long timeo = sock_rcvtimeo(sk, noblock);
 657
 658         for (;;) {
 659                 DEFINE_WAIT(wait);
 660
 661                 if (sk->sk_state != TCP_LISTEN)
 662                         return -EINVAL;
 663                 if (!hlist_empty(&pn->ackq))
 664                         break;
 665                 if (!timeo)
 666                         return -EWOULDBLOCK;
 667                 if (signal_pending(tsk))
 668                         return sock_intr_errno(timeo);
 669
 670                 prepare_to_wait_exclusive(sk_sleep(sk), &wait,
 671                                                 TASK_INTERRUPTIBLE);
 672                 release_sock(sk);
 673                 timeo = schedule_timeout(timeo);
 674                 lock_sock(sk);
 675                 finish_wait(sk_sleep(sk), &wait);
 676         }
 677
 678         return 0;
 679 }
 680
 681 static struct sock *pep_sock_accept(struct sock *sk, int flags, int *errp)
 682 {
 683         struct pep_sock *pn = pep_sk(sk);
 684         struct sock *newsk = NULL;
 685         struct sk_buff *oskb;
 686         int err;
 687
 688         lock_sock(sk);
 689         err = pep_wait_connreq(sk, flags & O_NONBLOCK);
 690         if (err)
 691                 goto out;
 692
 693         newsk = __sk_head(&pn->ackq);
 694
 695         oskb = skb_dequeue(&newsk->sk_receive_queue);
 696         err = pep_accept_conn(newsk, oskb);
 697         if (err) {
 698                 skb_queue_head(&newsk->sk_receive_queue, oskb);
 699                 newsk = NULL;
 700                 goto out;
 701         }
 702         kfree_skb(oskb);
 703
 704         sock_hold(sk);
 705         pep_sk(newsk)->listener = sk;
 706
 707         sock_hold(newsk);
 708         sk_del_node_init(newsk);
 709         sk_acceptq_removed(sk);
 710         sk_add_node(newsk, &pn->hlist);
 711         __sock_put(newsk);
 712
 713 out:
 714         release_sock(sk);
 715         *errp = err;
 716         return newsk;
 717 }
 718
 719 static int pep_ioctl(struct sock *sk, int cmd, unsigned long arg)
 720 {
 721         struct pep_sock *pn = pep_sk(sk);
 722         int answ;
 723
 724         switch (cmd) {
 725         case SIOCINQ:
 726                 if (sk->sk_state == TCP_LISTEN)
 727                         return -EINVAL;
 728
 729                 lock_sock(sk);
 730                 if (sock_flag(sk, SOCK_URGINLINE) &&
 731                     !skb_queue_empty(&pn->ctrlreq_queue))
 732                         answ = skb_peek(&pn->ctrlreq_queue)->len;
 733                 else if (!skb_queue_empty(&sk->sk_receive_queue))
 734                         answ = skb_peek(&sk->sk_receive_queue)->len;
 735                 else
 736                         answ = 0;
 737                 release_sock(sk);
 738                 return put_user(answ, (int __user *)arg);
 739         }
 740
 741         return -ENOIOCTLCMD;
 742 }
 743
 744 static int pep_init(struct sock *sk)
 745 {
 746         struct pep_sock *pn = pep_sk(sk);
 747
 748         INIT_HLIST_HEAD(&pn->ackq);
 749         INIT_HLIST_HEAD(&pn->hlist);
 750         skb_queue_head_init(&pn->ctrlreq_queue);
 751         pn->pipe_handle = PN_PIPE_INVALID_HANDLE;
 752         return 0;
 753 }
 754
 755 static int pep_setsockopt(struct sock *sk, int level, int optname,
 756                                 char __user *optval, unsigned int optlen)
 757 {
 758         struct pep_sock *pn = pep_sk(sk);
 759         int val = 0, err = 0;
 760
 761         if (level != SOL_PNPIPE)
 762                 return -ENOPROTOOPT;
 763         if (optlen >= sizeof(int)) {
 764                 if (get_user(val, (int __user *) optval))
 765                         return -EFAULT;
 766         }
 767
 768         lock_sock(sk);
 769         switch (optname) {
 770         case PNPIPE_ENCAP:
 771                 if (val && val != PNPIPE_ENCAP_IP) {
 772                         err = -EINVAL;
 773                         break;
 774                 }
 775                 if (!pn->ifindex == !val)
 776                         break; /* Nothing to do! */
 777                 if (!capable(CAP_NET_ADMIN)) {
 778                         err = -EPERM;
 779                         break;
 780                 }
 781                 if (val) {
 782                         release_sock(sk);
 783                         err = gprs_attach(sk);
 784                         if (err > 0) {
 785                                 pn->ifindex = err;
 786                                 err = 0;
 787                         }
 788                 } else {
 789                         pn->ifindex = 0;
 790                         release_sock(sk);
 791                         gprs_detach(sk);
 792                         err = 0;
 793                 }
 794                 goto out_norel;
 795         default:
 796                 err = -ENOPROTOOPT;
 797         }
 798         release_sock(sk);
 799
 800 out_norel:
 801         return err;
 802 }
 803
 804 static int pep_getsockopt(struct sock *sk, int level, int optname,
 805                                 char __user *optval, int __user *optlen)
 806 {
 807         struct pep_sock *pn = pep_sk(sk);
 808         int len, val;
 809
 810         if (level != SOL_PNPIPE)
 811                 return -ENOPROTOOPT;
 812         if (get_user(len, optlen))
 813                 return -EFAULT;
 814
 815         switch (optname) {
 816         case PNPIPE_ENCAP:
 817                 val = pn->ifindex ? PNPIPE_ENCAP_IP : PNPIPE_ENCAP_NONE;
 818                 break;
 819         case PNPIPE_IFINDEX:
 820                 val = pn->ifindex;
 821                 break;
 822         default:
 823                 return -ENOPROTOOPT;
 824         }
 825
 826         len = min_t(unsigned int, sizeof(int), len);
 827         if (put_user(len, optlen))
 828                 return -EFAULT;
 829         if (put_user(val, (int __user *) optval))
 830                 return -EFAULT;
 831         return 0;
 832 }
 833
 834 static int pipe_skb_send(struct sock *sk, struct sk_buff *skb)
 835 {
 836         struct pep_sock *pn = pep_sk(sk);
 837         struct pnpipehdr *ph;
 838
 839         if (pn_flow_safe(pn->tx_fc) &&
 840             !atomic_add_unless(&pn->tx_credits, -1, 0)) {
 841                 kfree_skb(skb);
 842                 return -ENOBUFS;
 843         }
 844
 845         skb_push(skb, 3 + pn->aligned);
 846         skb_reset_transport_header(skb);
 847         ph = pnp_hdr(skb);
 848         ph->utid = 0;
 849         if (pn->aligned) {
 850                 ph->message_id = PNS_PIPE_ALIGNED_DATA;
 851                 ph->data[0] = 0; /* padding */
 852         } else
 853                 ph->message_id = PNS_PIPE_DATA;
 854         ph->pipe_handle = pn->pipe_handle;
 855
 856         return pn_skb_send(sk, skb, &pipe_srv);
 857 }
 858
 859 static int pep_sendmsg(struct kiocb *iocb, struct sock *sk,
 860                         struct msghdr *msg, size_t len)
 861 {
 862         struct pep_sock *pn = pep_sk(sk);
 863         struct sk_buff *skb;
 864         long timeo;
 865         int flags = msg->msg_flags;
 866         int err, done;
 867
 868         if ((msg->msg_flags & ~(MSG_DONTWAIT|MSG_EOR|MSG_NOSIGNAL|
 869                                 MSG_CMSG_COMPAT)) ||
 870                         !(msg->msg_flags & MSG_EOR))
 871                 return -EOPNOTSUPP;
 872
 873         skb = sock_alloc_send_skb(sk, MAX_PNPIPE_HEADER + len,
 874                                         flags & MSG_DONTWAIT, &err);
 875         if (!skb)
 876                 return -ENOBUFS;
 877
 878         skb_reserve(skb, MAX_PHONET_HEADER + 3);
 879         err = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len);
 880         if (err < 0)
 881                 goto outfree;
 882
 883         lock_sock(sk);
 884         timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT);
 885         if ((1 << sk->sk_state) & (TCPF_LISTEN|TCPF_CLOSE)) {
 886                 err = -ENOTCONN;
 887                 goto out;
 888         }
 889         if (sk->sk_state != TCP_ESTABLISHED) {
 890                 /* Wait until the pipe gets to enabled state */
 891 disabled:
 892                 err = sk_stream_wait_connect(sk, &timeo);
 893                 if (err)
 894                         goto out;
 895
 896                 if (sk->sk_state == TCP_CLOSE_WAIT) {
 897                         err = -ECONNRESET;
 898                         goto out;
 899                 }
 900         }
 901         BUG_ON(sk->sk_state != TCP_ESTABLISHED);
 902
 903         /* Wait until flow control allows TX */
 904         done = atomic_read(&pn->tx_credits);
 905         while (!done) {
 906                 DEFINE_WAIT(wait);
 907
 908                 if (!timeo) {
 909                         err = -EAGAIN;
 910                         goto out;
 911                 }
 912                 if (signal_pending(current)) {
 913                         err = sock_intr_errno(timeo);
 914                         goto out;
 915                 }
 916
 917                 prepare_to_wait(sk_sleep(sk), &wait,
 918                                 TASK_INTERRUPTIBLE);
 919                 done = sk_wait_event(sk, &timeo, atomic_read(&pn->tx_credits));
 920                 finish_wait(sk_sleep(sk), &wait);
 921
 922                 if (sk->sk_state != TCP_ESTABLISHED)
 923                         goto disabled;
 924         }
 925
 926         err = pipe_skb_send(sk, skb);
 927         if (err >= 0)
 928                 err = len; /* success! */
 929         skb = NULL;
 930 out:
 931         release_sock(sk);
 932 outfree:
 933         kfree_skb(skb);
 934         return err;
 935 }
 936
 937 int pep_writeable(struct sock *sk)
 938 {
 939         struct pep_sock *pn = pep_sk(sk);
 940
 941         return atomic_read(&pn->tx_credits);
 942 }
 943
 944 int pep_write(struct sock *sk, struct sk_buff *skb)
 945 {
 946         struct sk_buff *rskb, *fs;
 947         int flen = 0;
 948
 949         if (pep_sk(sk)->aligned)
 950                 return pipe_skb_send(sk, skb);
 951
 952         rskb = alloc_skb(MAX_PNPIPE_HEADER, GFP_ATOMIC);
 953         if (!rskb) {
 954                 kfree_skb(skb);
 955                 return -ENOMEM;
 956         }
 957         skb_shinfo(rskb)->frag_list = skb;
 958         rskb->len += skb->len;
 959         rskb->data_len += rskb->len;
 960         rskb->truesize += rskb->len;
 961
 962         /* Avoid nested fragments */
 963         skb_walk_frags(skb, fs)
 964                 flen += fs->len;
 965         skb->next = skb_shinfo(skb)->frag_list;
 966         skb_frag_list_init(skb);
 967         skb->len -= flen;
 968         skb->data_len -= flen;
 969         skb->truesize -= flen;
 970
 971         skb_reserve(rskb, MAX_PHONET_HEADER + 3);
 972         return pipe_skb_send(sk, rskb);
 973 }
 974
 975 struct sk_buff *pep_read(struct sock *sk)
 976 {
 977         struct sk_buff *skb = skb_dequeue(&sk->sk_receive_queue);
 978
 979         if (sk->sk_state == TCP_ESTABLISHED)
 980                 pipe_grant_credits(sk);
 981         return skb;
 982 }
 983
 984 static int pep_recvmsg(struct kiocb *iocb, struct sock *sk,
 985                         struct msghdr *msg, size_t len, int noblock,
 986                         int flags, int *addr_len)
 987 {
 988         struct sk_buff *skb;
 989         int err;
 990
 991         if (flags & ~(MSG_OOB|MSG_PEEK|MSG_TRUNC|MSG_DONTWAIT|MSG_WAITALL|
 992                         MSG_NOSIGNAL|MSG_CMSG_COMPAT))
 993                 return -EOPNOTSUPP;
 994
 995         if (unlikely(1 << sk->sk_state & (TCPF_LISTEN | TCPF_CLOSE)))
 996                 return -ENOTCONN;
 997
 998         if ((flags & MSG_OOB) || sock_flag(sk, SOCK_URGINLINE)) {
 999                 /* Dequeue and acknowledge control request */
1000                 struct pep_sock *pn = pep_sk(sk);
1001
1002                 if (flags & MSG_PEEK)
1003                         return -EOPNOTSUPP;
1004                 skb = skb_dequeue(&pn->ctrlreq_queue);
1005                 if (skb) {
1006                         pep_ctrlreq_error(sk, skb, PN_PIPE_NO_ERROR,
1007                                                 GFP_KERNEL);
1008                         msg->msg_flags |= MSG_OOB;
1009                         goto copy;
1010                 }
1011                 if (flags & MSG_OOB)
1012                         return -EINVAL;
1013         }
1014
1015         skb = skb_recv_datagram(sk, flags, noblock, &err);
1016         lock_sock(sk);
1017         if (skb == NULL) {
1018                 if (err == -ENOTCONN && sk->sk_state == TCP_CLOSE_WAIT)
1019                         err = -ECONNRESET;
1020                 release_sock(sk);
1021                 return err;
1022         }
1023
1024         if (sk->sk_state == TCP_ESTABLISHED)
1025                 pipe_grant_credits(sk);
1026         release_sock(sk);
1027 copy:
1028         msg->msg_flags |= MSG_EOR;
1029         if (skb->len > len)
1030                 msg->msg_flags |= MSG_TRUNC;
1031         else
1032                 len = skb->len;
1033
1034         err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, len);
1035         if (!err)
1036                 err = (flags & MSG_TRUNC) ? skb->len : len;
1037
1038         skb_free_datagram(sk, skb);
1039         return err;
1040 }
1041
1042 static void pep_sock_unhash(struct sock *sk)
1043 {
1044         struct pep_sock *pn = pep_sk(sk);
1045         struct sock *skparent = NULL;
1046
1047         lock_sock(sk);
1048         if ((1 << sk->sk_state) & ~(TCPF_CLOSE|TCPF_LISTEN)) {
1049                 skparent = pn->listener;
1050                 release_sock(sk);
1051
1052                 pn = pep_sk(skparent);
1053                 lock_sock(skparent);
1054                 sk_del_node_init(sk);
1055                 sk = skparent;
1056         }
1057         /* Unhash a listening sock only when it is closed
1058          * and all of its active connected pipes are closed. */
1059         if (hlist_empty(&pn->hlist))
1060                 pn_sock_unhash(&pn->pn_sk.sk);
1061         release_sock(sk);
1062
1063         if (skparent)
1064                 sock_put(skparent);
1065 }
1066
1067 static struct proto pep_proto = {
1068         .close          = pep_sock_close,
1069         .accept         = pep_sock_accept,
1070         .ioctl          = pep_ioctl,
1071         .init           = pep_init,
1072         .setsockopt     = pep_setsockopt,
1073         .getsockopt     = pep_getsockopt,
1074         .sendmsg        = pep_sendmsg,
1075         .recvmsg        = pep_recvmsg,
1076         .backlog_rcv    = pep_do_rcv,
1077         .hash           = pn_sock_hash,
1078         .unhash         = pep_sock_unhash,
1079         .get_port       = pn_sock_get_port,
1080         .obj_size       = sizeof(struct pep_sock),
1081         .owner          = THIS_MODULE,
1082         .name           = "PNPIPE",
1083 };
1084
1085 static struct phonet_protocol pep_pn_proto = {
1086         .ops            = &phonet_stream_ops,
1087         .prot           = &pep_proto,
1088         .sock_type      = SOCK_SEQPACKET,
1089 };
1090
1091 static int __init pep_register(void)
1092 {
1093         return phonet_proto_register(PN_PROTO_PIPE, &pep_pn_proto);
1094 }
1095
1096 static void __exit pep_unregister(void)
1097 {
1098         phonet_proto_unregister(PN_PROTO_PIPE, &pep_pn_proto);
1099 }
1100
1101 module_init(pep_register);
1102 module_exit(pep_unregister);
1103 MODULE_AUTHOR("Remi Denis-Courmont, Nokia");
1104 MODULE_DESCRIPTION("Phonet pipe protocol");
1105 MODULE_LICENSE("GPL");
1106 MODULE_ALIAS_NET_PF_PROTO(PF_PHONET, PN_PROTO_PIPE);