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 = pnp_hdr(skb);
 228         int wake = 0;
 229
 230         if (!pskb_may_pull(skb, sizeof(*hdr) + 4))
 231                 return -EINVAL;
 232
 233         if (hdr->data[0] != PN_PEP_TYPE_COMMON) {
 234                 LIMIT_NETDEBUG(KERN_DEBUG"Phonet unknown PEP type: %u\n",
 235                                 (unsigned)hdr->data[0]);
 236                 return -EOPNOTSUPP;
 237         }
 238
 239         switch (hdr->data[1]) {
 240         case PN_PEP_IND_FLOW_CONTROL:
 241                 switch (pn->tx_fc) {
 242                 case PN_LEGACY_FLOW_CONTROL:
 243                         switch (hdr->data[4]) {
 244                         case PEP_IND_BUSY:
 245                                 atomic_set(&pn->tx_credits, 0);
 246                                 break;
 247                         case PEP_IND_READY:
 248                                 atomic_set(&pn->tx_credits, wake = 1);
 249                                 break;
 250                         }
 251                         break;
 252                 case PN_ONE_CREDIT_FLOW_CONTROL:
 253                         if (hdr->data[4] == PEP_IND_READY)
 254                                 atomic_set(&pn->tx_credits, wake = 1);
 255                         break;
 256                 }
 257                 break;
 258
 259         case PN_PEP_IND_ID_MCFC_GRANT_CREDITS:
 260                 if (pn->tx_fc != PN_MULTI_CREDIT_FLOW_CONTROL)
 261                         break;
 262                 atomic_add(wake = hdr->data[4], &pn->tx_credits);
 263                 break;
 264
 265         default:
 266                 LIMIT_NETDEBUG(KERN_DEBUG"Phonet unknown PEP indication: %u\n",
 267                                 (unsigned)hdr->data[1]);
 268                 return -EOPNOTSUPP;
 269         }
 270         if (wake)
 271                 sk->sk_write_space(sk);
 272         return 0;
 273 }
 274
 275 static int pipe_rcv_created(struct sock *sk, struct sk_buff *skb)
 276 {
 277         struct pep_sock *pn = pep_sk(sk);
 278         struct pnpipehdr *hdr = pnp_hdr(skb);
 279         u8 n_sb = hdr->data[0];
 280
 281         pn->rx_fc = pn->tx_fc = PN_LEGACY_FLOW_CONTROL;
 282         __skb_pull(skb, sizeof(*hdr));
 283         while (n_sb > 0) {
 284                 u8 type, buf[2], len = sizeof(buf);
 285                 u8 *data = pep_get_sb(skb, &type, &len, buf);
 286
 287                 if (data == NULL)
 288                         return -EINVAL;
 289                 switch (type) {
 290                 case PN_PIPE_SB_NEGOTIATED_FC:
 291                         if (len < 2 || (data[0] | data[1]) > 3)
 292                                 break;
 293                         pn->tx_fc = data[0] & 3;
 294                         pn->rx_fc = data[1] & 3;
 295                         break;
 296                 }
 297                 n_sb--;
 298         }
 299         return 0;
 300 }
 301
 302 /* Queue an skb to a connected sock.
 303  * Socket lock must be held. */
 304 static int pipe_do_rcv(struct sock *sk, struct sk_buff *skb)
 305 {
 306         struct pep_sock *pn = pep_sk(sk);
 307         struct pnpipehdr *hdr = pnp_hdr(skb);
 308         struct sk_buff_head *queue;
 309         int err = 0;
 310
 311         BUG_ON(sk->sk_state == TCP_CLOSE_WAIT);
 312
 313         switch (hdr->message_id) {
 314         case PNS_PEP_CONNECT_REQ:
 315                 pep_reject_conn(sk, skb, PN_PIPE_ERR_PEP_IN_USE);
 316                 break;
 317
 318         case PNS_PEP_DISCONNECT_REQ:
 319                 pep_reply(sk, skb, PN_PIPE_NO_ERROR, NULL, 0, GFP_ATOMIC);
 320                 sk->sk_state = TCP_CLOSE_WAIT;
 321                 if (!sock_flag(sk, SOCK_DEAD))
 322                         sk->sk_state_change(sk);
 323                 break;
 324
 325         case PNS_PEP_ENABLE_REQ:
 326                 /* Wait for PNS_PIPE_(ENABLED|REDIRECTED)_IND */
 327                 pep_reply(sk, skb, PN_PIPE_NO_ERROR, NULL, 0, GFP_ATOMIC);
 328                 break;
 329
 330         case PNS_PEP_RESET_REQ:
 331                 switch (hdr->state_after_reset) {
 332                 case PN_PIPE_DISABLE:
 333                         pn->init_enable = 0;
 334                         break;
 335                 case PN_PIPE_ENABLE:
 336                         pn->init_enable = 1;
 337                         break;
 338                 default: /* not allowed to send an error here!? */
 339                         err = -EINVAL;
 340                         goto out;
 341                 }
 342                 /* fall through */
 343         case PNS_PEP_DISABLE_REQ:
 344                 atomic_set(&pn->tx_credits, 0);
 345                 pep_reply(sk, skb, PN_PIPE_NO_ERROR, NULL, 0, GFP_ATOMIC);
 346                 break;
 347
 348         case PNS_PEP_CTRL_REQ:
 349                 if (skb_queue_len(&pn->ctrlreq_queue) >= PNPIPE_CTRLREQ_MAX) {
 350                         atomic_inc(&sk->sk_drops);
 351                         break;
 352                 }
 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                         atomic_inc(&sk->sk_drops);
 368                         err = -ENOBUFS;
 369                         break;
 370                 }
 371                 pn->rx_credits--;
 372                 queue = &sk->sk_receive_queue;
 373                 goto queue;
 374
 375         case PNS_PEP_STATUS_IND:
 376                 pipe_rcv_status(sk, skb);
 377                 break;
 378
 379         case PNS_PIPE_REDIRECTED_IND:
 380                 err = pipe_rcv_created(sk, skb);
 381                 break;
 382
 383         case PNS_PIPE_CREATED_IND:
 384                 err = pipe_rcv_created(sk, skb);
 385                 if (err)
 386                         break;
 387                 /* fall through */
 388         case PNS_PIPE_RESET_IND:
 389                 if (!pn->init_enable)
 390                         break;
 391                 /* fall through */
 392         case PNS_PIPE_ENABLED_IND:
 393                 if (!pn_flow_safe(pn->tx_fc)) {
 394                         atomic_set(&pn->tx_credits, 1);
 395                         sk->sk_write_space(sk);
 396                 }
 397                 if (sk->sk_state == TCP_ESTABLISHED)
 398                         break; /* Nothing to do */
 399                 sk->sk_state = TCP_ESTABLISHED;
 400                 pipe_grant_credits(sk);
 401                 break;
 402
 403         case PNS_PIPE_DISABLED_IND:
 404                 sk->sk_state = TCP_SYN_RECV;
 405                 pn->rx_credits = 0;
 406                 break;
 407
 408         default:
 409                 LIMIT_NETDEBUG(KERN_DEBUG"Phonet unknown PEP message: %u\n",
 410                                 hdr->message_id);
 411                 err = -EINVAL;
 412         }
 413 out:
 414         kfree_skb(skb);
 415         return err;
 416
 417 queue:
 418         skb->dev = NULL;
 419         skb_set_owner_r(skb, sk);
 420         err = skb->len;
 421         skb_queue_tail(queue, skb);
 422         if (!sock_flag(sk, SOCK_DEAD))
 423                 sk->sk_data_ready(sk, err);
 424         return 0;
 425 }
 426
 427 /* Destroy connected sock. */
 428 static void pipe_destruct(struct sock *sk)
 429 {
 430         struct pep_sock *pn = pep_sk(sk);
 431
 432         skb_queue_purge(&sk->sk_receive_queue);
 433         skb_queue_purge(&pn->ctrlreq_queue);
 434 }
 435
 436 static int pep_connreq_rcv(struct sock *sk, struct sk_buff *skb)
 437 {
 438         struct sock *newsk;
 439         struct pep_sock *newpn, *pn = pep_sk(sk);
 440         struct pnpipehdr *hdr;
 441         struct sockaddr_pn dst;
 442         u16 peer_type;
 443         u8 pipe_handle, enabled, n_sb;
 444
 445         if (!pskb_pull(skb, sizeof(*hdr) + 4))
 446                 return -EINVAL;
 447
 448         hdr = pnp_hdr(skb);
 449         pipe_handle = hdr->pipe_handle;
 450         switch (hdr->state_after_connect) {
 451         case PN_PIPE_DISABLE:
 452                 enabled = 0;
 453                 break;
 454         case PN_PIPE_ENABLE:
 455                 enabled = 1;
 456                 break;
 457         default:
 458                 pep_reject_conn(sk, skb, PN_PIPE_ERR_INVALID_PARAM);
 459                 return -EINVAL;
 460         }
 461         peer_type = hdr->other_pep_type << 8;
 462
 463         if (unlikely(sk->sk_state != TCP_LISTEN) || sk_acceptq_is_full(sk)) {
 464                 pep_reject_conn(sk, skb, PN_PIPE_ERR_PEP_IN_USE);
 465                 return -ENOBUFS;
 466         }
 467
 468         /* Parse sub-blocks (options) */
 469         n_sb = hdr->data[4];
 470         while (n_sb > 0) {
 471                 u8 type, buf[1], len = sizeof(buf);
 472                 const u8 *data = pep_get_sb(skb, &type, &len, buf);
 473
 474                 if (data == NULL)
 475                         return -EINVAL;
 476                 switch (type) {
 477                 case PN_PIPE_SB_CONNECT_REQ_PEP_SUB_TYPE:
 478                         if (len < 1)
 479                                 return -EINVAL;
 480                         peer_type = (peer_type & 0xff00) | data[0];
 481                         break;
 482                 }
 483                 n_sb--;
 484         }
 485
 486         skb = skb_clone(skb, GFP_ATOMIC);
 487         if (!skb)
 488                 return -ENOMEM;
 489
 490         /* Create a new to-be-accepted sock */
 491         newsk = sk_alloc(sock_net(sk), PF_PHONET, GFP_ATOMIC, sk->sk_prot);
 492         if (!newsk) {
 493                 kfree_skb(skb);
 494                 return -ENOMEM;
 495         }
 496         sock_init_data(NULL, newsk);
 497         newsk->sk_state = TCP_SYN_RECV;
 498         newsk->sk_backlog_rcv = pipe_do_rcv;
 499         newsk->sk_protocol = sk->sk_protocol;
 500         newsk->sk_destruct = pipe_destruct;
 501
 502         newpn = pep_sk(newsk);
 503         pn_skb_get_dst_sockaddr(skb, &dst);
 504         newpn->pn_sk.sobject = pn_sockaddr_get_object(&dst);
 505         newpn->pn_sk.resource = pn->pn_sk.resource;
 506         skb_queue_head_init(&newpn->ctrlreq_queue);
 507         newpn->pipe_handle = pipe_handle;
 508         atomic_set(&newpn->tx_credits, 0);
 509         newpn->peer_type = peer_type;
 510         newpn->rx_credits = 0;
 511         newpn->rx_fc = newpn->tx_fc = PN_LEGACY_FLOW_CONTROL;
 512         newpn->init_enable = enabled;
 513
 514         BUG_ON(!skb_queue_empty(&newsk->sk_receive_queue));
 515         skb_queue_head(&newsk->sk_receive_queue, skb);
 516         if (!sock_flag(sk, SOCK_DEAD))
 517                 sk->sk_data_ready(sk, 0);
 518
 519         sk_acceptq_added(sk);
 520         sk_add_node(newsk, &pn->ackq);
 521         return 0;
 522 }
 523
 524 /* Listening sock must be locked */
 525 static struct sock *pep_find_pipe(const struct hlist_head *hlist,
 526                                         const struct sockaddr_pn *dst,
 527                                         u8 pipe_handle)
 528 {
 529         struct hlist_node *node;
 530         struct sock *sknode;
 531         u16 dobj = pn_sockaddr_get_object(dst);
 532
 533         sk_for_each(sknode, node, hlist) {
 534                 struct pep_sock *pnnode = pep_sk(sknode);
 535
 536                 /* Ports match, but addresses might not: */
 537                 if (pnnode->pn_sk.sobject != dobj)
 538                         continue;
 539                 if (pnnode->pipe_handle != pipe_handle)
 540                         continue;
 541                 if (sknode->sk_state == TCP_CLOSE_WAIT)
 542                         continue;
 543
 544                 sock_hold(sknode);
 545                 return sknode;
 546         }
 547         return NULL;
 548 }
 549
 550 /*
 551  * Deliver an skb to a listening sock.
 552  * Socket lock must be held.
 553  * We then queue the skb to the right connected sock (if any).
 554  */
 555 static int pep_do_rcv(struct sock *sk, struct sk_buff *skb)
 556 {
 557         struct pep_sock *pn = pep_sk(sk);
 558         struct sock *sknode;
 559         struct pnpipehdr *hdr;
 560         struct sockaddr_pn dst;
 561         int err = NET_RX_SUCCESS;
 562         u8 pipe_handle;
 563
 564         if (!pskb_may_pull(skb, sizeof(*hdr)))
 565                 goto drop;
 566
 567         hdr = pnp_hdr(skb);
 568         pipe_handle = hdr->pipe_handle;
 569         if (pipe_handle == PN_PIPE_INVALID_HANDLE)
 570                 goto drop;
 571
 572         pn_skb_get_dst_sockaddr(skb, &dst);
 573
 574         /* Look for an existing pipe handle */
 575         sknode = pep_find_pipe(&pn->hlist, &dst, pipe_handle);
 576         if (sknode)
 577                 return sk_receive_skb(sknode, skb, 1);
 578
 579         /* Look for a pipe handle pending accept */
 580         sknode = pep_find_pipe(&pn->ackq, &dst, pipe_handle);
 581         if (sknode) {
 582                 sock_put(sknode);
 583                 if (net_ratelimit())
 584                         printk(KERN_WARNING"Phonet unconnected PEP ignored");
 585                 err = NET_RX_DROP;
 586                 goto drop;
 587         }
 588
 589         switch (hdr->message_id) {
 590         case PNS_PEP_CONNECT_REQ:
 591                 err = pep_connreq_rcv(sk, skb);
 592                 break;
 593
 594         case PNS_PEP_DISCONNECT_REQ:
 595                 pep_reply(sk, skb, PN_PIPE_NO_ERROR, NULL, 0, GFP_ATOMIC);
 596                 break;
 597
 598         case PNS_PEP_CTRL_REQ:
 599                 pep_ctrlreq_error(sk, skb, PN_PIPE_INVALID_HANDLE, GFP_ATOMIC);
 600                 break;
 601
 602         case PNS_PEP_RESET_REQ:
 603         case PNS_PEP_ENABLE_REQ:
 604         case PNS_PEP_DISABLE_REQ:
 605                 /* invalid handle is not even allowed here! */
 606         default:
 607                 err = NET_RX_DROP;
 608         }
 609 drop:
 610         kfree_skb(skb);
 611         return err;
 612 }
 613
 614 /* associated socket ceases to exist */
 615 static void pep_sock_close(struct sock *sk, long timeout)
 616 {
 617         struct pep_sock *pn = pep_sk(sk);
 618         int ifindex = 0;
 619
 620         sk_common_release(sk);
 621
 622         lock_sock(sk);
 623         if (sk->sk_state == TCP_LISTEN) {
 624                 /* Destroy the listen queue */
 625                 struct sock *sknode;
 626                 struct hlist_node *p, *n;
 627
 628                 sk_for_each_safe(sknode, p, n, &pn->ackq)
 629                         sk_del_node_init(sknode);
 630                 sk->sk_state = TCP_CLOSE;
 631         }
 632         ifindex = pn->ifindex;
 633         pn->ifindex = 0;
 634         release_sock(sk);
 635
 636         if (ifindex)
 637                 gprs_detach(sk);
 638 }
 639
 640 static int pep_wait_connreq(struct sock *sk, int noblock)
 641 {
 642         struct task_struct *tsk = current;
 643         struct pep_sock *pn = pep_sk(sk);
 644         long timeo = sock_rcvtimeo(sk, noblock);
 645
 646         for (;;) {
 647                 DEFINE_WAIT(wait);
 648
 649                 if (sk->sk_state != TCP_LISTEN)
 650                         return -EINVAL;
 651                 if (!hlist_empty(&pn->ackq))
 652                         break;
 653                 if (!timeo)
 654                         return -EWOULDBLOCK;
 655                 if (signal_pending(tsk))
 656                         return sock_intr_errno(timeo);
 657
 658                 prepare_to_wait_exclusive(&sk->sk_socket->wait, &wait,
 659                                                 TASK_INTERRUPTIBLE);
 660                 release_sock(sk);
 661                 timeo = schedule_timeout(timeo);
 662                 lock_sock(sk);
 663                 finish_wait(&sk->sk_socket->wait, &wait);
 664         }
 665
 666         return 0;
 667 }
 668
 669 static struct sock *pep_sock_accept(struct sock *sk, int flags, int *errp)
 670 {
 671         struct pep_sock *pn = pep_sk(sk);
 672         struct sock *newsk = NULL;
 673         struct sk_buff *oskb;
 674         int err;
 675
 676         lock_sock(sk);
 677         err = pep_wait_connreq(sk, flags & O_NONBLOCK);
 678         if (err)
 679                 goto out;
 680
 681         newsk = __sk_head(&pn->ackq);
 682
 683         oskb = skb_dequeue(&newsk->sk_receive_queue);
 684         err = pep_accept_conn(newsk, oskb);
 685         if (err) {
 686                 skb_queue_head(&newsk->sk_receive_queue, oskb);
 687                 newsk = NULL;
 688                 goto out;
 689         }
 690
 691         sock_hold(sk);
 692         pep_sk(newsk)->listener = sk;
 693
 694         sock_hold(newsk);
 695         sk_del_node_init(newsk);
 696         sk_acceptq_removed(sk);
 697         sk_add_node(newsk, &pn->hlist);
 698         __sock_put(newsk);
 699
 700 out:
 701         release_sock(sk);
 702         *errp = err;
 703         return newsk;
 704 }
 705
 706 static int pep_ioctl(struct sock *sk, int cmd, unsigned long arg)
 707 {
 708         struct pep_sock *pn = pep_sk(sk);
 709         int answ;
 710
 711         switch (cmd) {
 712         case SIOCINQ:
 713                 if (sk->sk_state == TCP_LISTEN)
 714                         return -EINVAL;
 715
 716                 lock_sock(sk);
 717                 if (sock_flag(sk, SOCK_URGINLINE) &&
 718                     !skb_queue_empty(&pn->ctrlreq_queue))
 719                         answ = skb_peek(&pn->ctrlreq_queue)->len;
 720                 else if (!skb_queue_empty(&sk->sk_receive_queue))
 721                         answ = skb_peek(&sk->sk_receive_queue)->len;
 722                 else
 723                         answ = 0;
 724                 release_sock(sk);
 725                 return put_user(answ, (int __user *)arg);
 726         }
 727
 728         return -ENOIOCTLCMD;
 729 }
 730
 731 static int pep_init(struct sock *sk)
 732 {
 733         struct pep_sock *pn = pep_sk(sk);
 734
 735         INIT_HLIST_HEAD(&pn->ackq);
 736         INIT_HLIST_HEAD(&pn->hlist);
 737         skb_queue_head_init(&pn->ctrlreq_queue);
 738         pn->pipe_handle = PN_PIPE_INVALID_HANDLE;
 739         return 0;
 740 }
 741
 742 static int pep_setsockopt(struct sock *sk, int level, int optname,
 743                                 char __user *optval, unsigned int optlen)
 744 {
 745         struct pep_sock *pn = pep_sk(sk);
 746         int val = 0, err = 0;
 747
 748         if (level != SOL_PNPIPE)
 749                 return -ENOPROTOOPT;
 750         if (optlen >= sizeof(int)) {
 751                 if (get_user(val, (int __user *) optval))
 752                         return -EFAULT;
 753         }
 754
 755         lock_sock(sk);
 756         switch (optname) {
 757         case PNPIPE_ENCAP:
 758                 if (val && val != PNPIPE_ENCAP_IP) {
 759                         err = -EINVAL;
 760                         break;
 761                 }
 762                 if (!pn->ifindex == !val)
 763                         break; /* Nothing to do! */
 764                 if (!capable(CAP_NET_ADMIN)) {
 765                         err = -EPERM;
 766                         break;
 767                 }
 768                 if (val) {
 769                         release_sock(sk);
 770                         err = gprs_attach(sk);
 771                         if (err > 0) {
 772                                 pn->ifindex = err;
 773                                 err = 0;
 774                         }
 775                 } else {
 776                         pn->ifindex = 0;
 777                         release_sock(sk);
 778                         gprs_detach(sk);
 779                         err = 0;
 780                 }
 781                 goto out_norel;
 782         default:
 783                 err = -ENOPROTOOPT;
 784         }
 785         release_sock(sk);
 786
 787 out_norel:
 788         return err;
 789 }
 790
 791 static int pep_getsockopt(struct sock *sk, int level, int optname,
 792                                 char __user *optval, int __user *optlen)
 793 {
 794         struct pep_sock *pn = pep_sk(sk);
 795         int len, val;
 796
 797         if (level != SOL_PNPIPE)
 798                 return -ENOPROTOOPT;
 799         if (get_user(len, optlen))
 800                 return -EFAULT;
 801
 802         switch (optname) {
 803         case PNPIPE_ENCAP:
 804                 val = pn->ifindex ? PNPIPE_ENCAP_IP : PNPIPE_ENCAP_NONE;
 805                 break;
 806         case PNPIPE_IFINDEX:
 807                 val = pn->ifindex;
 808                 break;
 809         default:
 810                 return -ENOPROTOOPT;
 811         }
 812
 813         len = min_t(unsigned int, sizeof(int), len);
 814         if (put_user(len, optlen))
 815                 return -EFAULT;
 816         if (put_user(val, (int __user *) optval))
 817                 return -EFAULT;
 818         return 0;
 819 }
 820
 821 static int pipe_skb_send(struct sock *sk, struct sk_buff *skb)
 822 {
 823         struct pep_sock *pn = pep_sk(sk);
 824         struct pnpipehdr *ph;
 825
 826         if (pn_flow_safe(pn->tx_fc) &&
 827             !atomic_add_unless(&pn->tx_credits, -1, 0)) {
 828                 kfree_skb(skb);
 829                 return -ENOBUFS;
 830         }
 831
 832         skb_push(skb, 3);
 833         skb_reset_transport_header(skb);
 834         ph = pnp_hdr(skb);
 835         ph->utid = 0;
 836         ph->message_id = PNS_PIPE_DATA;
 837         ph->pipe_handle = pn->pipe_handle;
 838
 839         return pn_skb_send(sk, skb, &pipe_srv);
 840 }
 841
 842 static int pep_sendmsg(struct kiocb *iocb, struct sock *sk,
 843                         struct msghdr *msg, size_t len)
 844 {
 845         struct pep_sock *pn = pep_sk(sk);
 846         struct sk_buff *skb;
 847         long timeo;
 848         int flags = msg->msg_flags;
 849         int err, done;
 850
 851         if (msg->msg_flags & MSG_OOB || !(msg->msg_flags & MSG_EOR))
 852                 return -EOPNOTSUPP;
 853
 854         skb = sock_alloc_send_skb(sk, MAX_PNPIPE_HEADER + len,
 855                                         flags & MSG_DONTWAIT, &err);
 856         if (!skb)
 857                 return -ENOBUFS;
 858
 859         skb_reserve(skb, MAX_PHONET_HEADER + 3);
 860         err = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len);
 861         if (err < 0)
 862                 goto outfree;
 863
 864         lock_sock(sk);
 865         timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT);
 866         if ((1 << sk->sk_state) & (TCPF_LISTEN|TCPF_CLOSE)) {
 867                 err = -ENOTCONN;
 868                 goto out;
 869         }
 870         if (sk->sk_state != TCP_ESTABLISHED) {
 871                 /* Wait until the pipe gets to enabled state */
 872 disabled:
 873                 err = sk_stream_wait_connect(sk, &timeo);
 874                 if (err)
 875                         goto out;
 876
 877                 if (sk->sk_state == TCP_CLOSE_WAIT) {
 878                         err = -ECONNRESET;
 879                         goto out;
 880                 }
 881         }
 882         BUG_ON(sk->sk_state != TCP_ESTABLISHED);
 883
 884         /* Wait until flow control allows TX */
 885         done = atomic_read(&pn->tx_credits);
 886         while (!done) {
 887                 DEFINE_WAIT(wait);
 888
 889                 if (!timeo) {
 890                         err = -EAGAIN;
 891                         goto out;
 892                 }
 893                 if (signal_pending(current)) {
 894                         err = sock_intr_errno(timeo);
 895                         goto out;
 896                 }
 897
 898                 prepare_to_wait(&sk->sk_socket->wait, &wait,
 899                                 TASK_INTERRUPTIBLE);
 900                 done = sk_wait_event(sk, &timeo, atomic_read(&pn->tx_credits));
 901                 finish_wait(&sk->sk_socket->wait, &wait);
 902
 903                 if (sk->sk_state != TCP_ESTABLISHED)
 904                         goto disabled;
 905         }
 906
 907         err = pipe_skb_send(sk, skb);
 908         if (err >= 0)
 909                 err = len; /* success! */
 910         skb = NULL;
 911 out:
 912         release_sock(sk);
 913 outfree:
 914         kfree_skb(skb);
 915         return err;
 916 }
 917
 918 int pep_writeable(struct sock *sk)
 919 {
 920         struct pep_sock *pn = pep_sk(sk);
 921
 922         return atomic_read(&pn->tx_credits);
 923 }
 924
 925 int pep_write(struct sock *sk, struct sk_buff *skb)
 926 {
 927         struct sk_buff *rskb, *fs;
 928         int flen = 0;
 929
 930         rskb = alloc_skb(MAX_PNPIPE_HEADER, GFP_ATOMIC);
 931         if (!rskb) {
 932                 kfree_skb(skb);
 933                 return -ENOMEM;
 934         }
 935         skb_shinfo(rskb)->frag_list = skb;
 936         rskb->len += skb->len;
 937         rskb->data_len += rskb->len;
 938         rskb->truesize += rskb->len;
 939
 940         /* Avoid nested fragments */
 941         skb_walk_frags(skb, fs)
 942                 flen += fs->len;
 943         skb->next = skb_shinfo(skb)->frag_list;
 944         skb_frag_list_init(skb);
 945         skb->len -= flen;
 946         skb->data_len -= flen;
 947         skb->truesize -= flen;
 948
 949         skb_reserve(rskb, MAX_PHONET_HEADER + 3);
 950         return pipe_skb_send(sk, rskb);
 951 }
 952
 953 struct sk_buff *pep_read(struct sock *sk)
 954 {
 955         struct sk_buff *skb = skb_dequeue(&sk->sk_receive_queue);
 956
 957         if (sk->sk_state == TCP_ESTABLISHED)
 958                 pipe_grant_credits(sk);
 959         return skb;
 960 }
 961
 962 static int pep_recvmsg(struct kiocb *iocb, struct sock *sk,
 963                         struct msghdr *msg, size_t len, int noblock,
 964                         int flags, int *addr_len)
 965 {
 966         struct sk_buff *skb;
 967         int err;
 968
 969         if (unlikely(1 << sk->sk_state & (TCPF_LISTEN | TCPF_CLOSE)))
 970                 return -ENOTCONN;
 971
 972         if ((flags & MSG_OOB) || sock_flag(sk, SOCK_URGINLINE)) {
 973                 /* Dequeue and acknowledge control request */
 974                 struct pep_sock *pn = pep_sk(sk);
 975
 976                 skb = skb_dequeue(&pn->ctrlreq_queue);
 977                 if (skb) {
 978                         pep_ctrlreq_error(sk, skb, PN_PIPE_NO_ERROR,
 979                                                 GFP_KERNEL);
 980                         msg->msg_flags |= MSG_OOB;
 981                         goto copy;
 982                 }
 983                 if (flags & MSG_OOB)
 984                         return -EINVAL;
 985         }
 986
 987         skb = skb_recv_datagram(sk, flags, noblock, &err);
 988         lock_sock(sk);
 989         if (skb == NULL) {
 990                 if (err == -ENOTCONN && sk->sk_state == TCP_CLOSE_WAIT)
 991                         err = -ECONNRESET;
 992                 release_sock(sk);
 993                 return err;
 994         }
 995
 996         if (sk->sk_state == TCP_ESTABLISHED)
 997                 pipe_grant_credits(sk);
 998         release_sock(sk);
 999 copy:
1000         msg->msg_flags |= MSG_EOR;
1001         if (skb->len > len)
1002                 msg->msg_flags |= MSG_TRUNC;
1003         else
1004                 len = skb->len;
1005
1006         err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, len);
1007         if (!err)
1008                 err = (flags & MSG_TRUNC) ? skb->len : len;
1009
1010         skb_free_datagram(sk, skb);
1011         return err;
1012 }
1013
1014 static void pep_sock_unhash(struct sock *sk)
1015 {
1016         struct pep_sock *pn = pep_sk(sk);
1017         struct sock *skparent = NULL;
1018
1019         lock_sock(sk);
1020         if ((1 << sk->sk_state) & ~(TCPF_CLOSE|TCPF_LISTEN)) {
1021                 skparent = pn->listener;
1022                 sk_del_node_init(sk);
1023                 release_sock(sk);
1024
1025                 sk = skparent;
1026                 pn = pep_sk(skparent);
1027                 lock_sock(sk);
1028         }
1029         /* Unhash a listening sock only when it is closed
1030          * and all of its active connected pipes are closed. */
1031         if (hlist_empty(&pn->hlist))
1032                 pn_sock_unhash(&pn->pn_sk.sk);
1033         release_sock(sk);
1034
1035         if (skparent)
1036                 sock_put(skparent);
1037 }
1038
1039 static struct proto pep_proto = {
1040         .close          = pep_sock_close,
1041         .accept         = pep_sock_accept,
1042         .ioctl          = pep_ioctl,
1043         .init           = pep_init,
1044         .setsockopt     = pep_setsockopt,
1045         .getsockopt     = pep_getsockopt,
1046         .sendmsg        = pep_sendmsg,
1047         .recvmsg        = pep_recvmsg,
1048         .backlog_rcv    = pep_do_rcv,
1049         .hash           = pn_sock_hash,
1050         .unhash         = pep_sock_unhash,
1051         .get_port       = pn_sock_get_port,
1052         .obj_size       = sizeof(struct pep_sock),
1053         .owner          = THIS_MODULE,
1054         .name           = "PNPIPE",
1055 };
1056
1057 static struct phonet_protocol pep_pn_proto = {
1058         .ops            = &phonet_stream_ops,
1059         .prot           = &pep_proto,
1060         .sock_type      = SOCK_SEQPACKET,
1061 };
1062
1063 static int __init pep_register(void)
1064 {
1065         return phonet_proto_register(PN_PROTO_PIPE, &pep_pn_proto);
1066 }
1067
1068 static void __exit pep_unregister(void)
1069 {
1070         phonet_proto_unregister(PN_PROTO_PIPE, &pep_pn_proto);
1071 }
1072
1073 module_init(pep_register);
1074 module_exit(pep_unregister);
1075 MODULE_AUTHOR("Remi Denis-Courmont, Nokia");
1076 MODULE_DESCRIPTION("Phonet pipe protocol");
1077 MODULE_LICENSE("GPL");
1078 MODULE_ALIAS_NET_PF_PROTO(PF_PHONET, PN_PROTO_PIPE);