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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         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                         break;
 351                 __skb_pull(skb, 4);
 352                 queue = &pn->ctrlreq_queue;
 353                 goto queue;
 354
 355         case PNS_PIPE_DATA:
 356                 __skb_pull(skb, 3); /* Pipe data header */
 357                 if (!pn_flow_safe(pn->rx_fc)) {
 358                         err = sock_queue_rcv_skb(sk, skb);
 359                         if (!err)
 360                                 return 0;
 361                         break;
 362                 }
 363
 364                 if (pn->rx_credits == 0) {
 365                         err = -ENOBUFS;
 366                         break;
 367                 }
 368                 pn->rx_credits--;
 369                 queue = &sk->sk_receive_queue;
 370                 goto queue;
 371
 372         case PNS_PEP_STATUS_IND:
 373                 pipe_rcv_status(sk, skb);
 374                 break;
 375
 376         case PNS_PIPE_REDIRECTED_IND:
 377                 err = pipe_rcv_created(sk, skb);
 378                 break;
 379
 380         case PNS_PIPE_CREATED_IND:
 381                 err = pipe_rcv_created(sk, skb);
 382                 if (err)
 383                         break;
 384                 /* fall through */
 385         case PNS_PIPE_RESET_IND:
 386                 if (!pn->init_enable)
 387                         break;
 388                 /* fall through */
 389         case PNS_PIPE_ENABLED_IND:
 390                 if (!pn_flow_safe(pn->tx_fc)) {
 391                         atomic_set(&pn->tx_credits, 1);
 392                         sk->sk_write_space(sk);
 393                 }
 394                 if (sk->sk_state == TCP_ESTABLISHED)
 395                         break; /* Nothing to do */
 396                 sk->sk_state = TCP_ESTABLISHED;
 397                 pipe_grant_credits(sk);
 398                 break;
 399
 400         case PNS_PIPE_DISABLED_IND:
 401                 sk->sk_state = TCP_SYN_RECV;
 402                 pn->rx_credits = 0;
 403                 break;
 404
 405         default:
 406                 LIMIT_NETDEBUG(KERN_DEBUG"Phonet unknown PEP message: %u\n",
 407                                 hdr->message_id);
 408                 err = -EINVAL;
 409         }
 410 out:
 411         kfree_skb(skb);
 412         return err;
 413
 414 queue:
 415         skb->dev = NULL;
 416         skb_set_owner_r(skb, sk);
 417         err = skb->len;
 418         skb_queue_tail(queue, skb);
 419         if (!sock_flag(sk, SOCK_DEAD))
 420                 sk->sk_data_ready(sk, err);
 421         return 0;
 422 }
 423
 424 /* Destroy connected sock. */
 425 static void pipe_destruct(struct sock *sk)
 426 {
 427         struct pep_sock *pn = pep_sk(sk);
 428
 429         skb_queue_purge(&sk->sk_receive_queue);
 430         skb_queue_purge(&pn->ctrlreq_queue);
 431 }
 432
 433 static int pep_connreq_rcv(struct sock *sk, struct sk_buff *skb)
 434 {
 435         struct sock *newsk;
 436         struct pep_sock *newpn, *pn = pep_sk(sk);
 437         struct pnpipehdr *hdr;
 438         struct sockaddr_pn dst;
 439         u16 peer_type;
 440         u8 pipe_handle, enabled, n_sb;
 441
 442         if (!pskb_pull(skb, sizeof(*hdr) + 4))
 443                 return -EINVAL;
 444
 445         hdr = pnp_hdr(skb);
 446         pipe_handle = hdr->pipe_handle;
 447         switch (hdr->state_after_connect) {
 448         case PN_PIPE_DISABLE:
 449                 enabled = 0;
 450                 break;
 451         case PN_PIPE_ENABLE:
 452                 enabled = 1;
 453                 break;
 454         default:
 455                 pep_reject_conn(sk, skb, PN_PIPE_ERR_INVALID_PARAM);
 456                 return -EINVAL;
 457         }
 458         peer_type = hdr->other_pep_type << 8;
 459
 460         if (unlikely(sk->sk_state != TCP_LISTEN) || sk_acceptq_is_full(sk)) {
 461                 pep_reject_conn(sk, skb, PN_PIPE_ERR_PEP_IN_USE);
 462                 return -ENOBUFS;
 463         }
 464
 465         /* Parse sub-blocks (options) */
 466         n_sb = hdr->data[4];
 467         while (n_sb > 0) {
 468                 u8 type, buf[1], len = sizeof(buf);
 469                 const u8 *data = pep_get_sb(skb, &type, &len, buf);
 470
 471                 if (data == NULL)
 472                         return -EINVAL;
 473                 switch (type) {
 474                 case PN_PIPE_SB_CONNECT_REQ_PEP_SUB_TYPE:
 475                         if (len < 1)
 476                                 return -EINVAL;
 477                         peer_type = (peer_type & 0xff00) | data[0];
 478                         break;
 479                 }
 480                 n_sb--;
 481         }
 482
 483         skb = skb_clone(skb, GFP_ATOMIC);
 484         if (!skb)
 485                 return -ENOMEM;
 486
 487         /* Create a new to-be-accepted sock */
 488         newsk = sk_alloc(sock_net(sk), PF_PHONET, GFP_ATOMIC, sk->sk_prot);
 489         if (!newsk) {
 490                 kfree_skb(skb);
 491                 return -ENOMEM;
 492         }
 493         sock_init_data(NULL, newsk);
 494         newsk->sk_state = TCP_SYN_RECV;
 495         newsk->sk_backlog_rcv = pipe_do_rcv;
 496         newsk->sk_protocol = sk->sk_protocol;
 497         newsk->sk_destruct = pipe_destruct;
 498
 499         newpn = pep_sk(newsk);
 500         pn_skb_get_dst_sockaddr(skb, &dst);
 501         newpn->pn_sk.sobject = pn_sockaddr_get_object(&dst);
 502         newpn->pn_sk.resource = pn->pn_sk.resource;
 503         skb_queue_head_init(&newpn->ctrlreq_queue);
 504         newpn->pipe_handle = pipe_handle;
 505         atomic_set(&newpn->tx_credits, 0);
 506         newpn->peer_type = peer_type;
 507         newpn->rx_credits = 0;
 508         newpn->rx_fc = newpn->tx_fc = PN_LEGACY_FLOW_CONTROL;
 509         newpn->init_enable = enabled;
 510
 511         BUG_ON(!skb_queue_empty(&newsk->sk_receive_queue));
 512         skb_queue_head(&newsk->sk_receive_queue, skb);
 513         if (!sock_flag(sk, SOCK_DEAD))
 514                 sk->sk_data_ready(sk, 0);
 515
 516         sk_acceptq_added(sk);
 517         sk_add_node(newsk, &pn->ackq);
 518         return 0;
 519 }
 520
 521 /* Listening sock must be locked */
 522 static struct sock *pep_find_pipe(const struct hlist_head *hlist,
 523                                         const struct sockaddr_pn *dst,
 524                                         u8 pipe_handle)
 525 {
 526         struct hlist_node *node;
 527         struct sock *sknode;
 528         u16 dobj = pn_sockaddr_get_object(dst);
 529
 530         sk_for_each(sknode, node, hlist) {
 531                 struct pep_sock *pnnode = pep_sk(sknode);
 532
 533                 /* Ports match, but addresses might not: */
 534                 if (pnnode->pn_sk.sobject != dobj)
 535                         continue;
 536                 if (pnnode->pipe_handle != pipe_handle)
 537                         continue;
 538                 if (sknode->sk_state == TCP_CLOSE_WAIT)
 539                         continue;
 540
 541                 sock_hold(sknode);
 542                 return sknode;
 543         }
 544         return NULL;
 545 }
 546
 547 /*
 548  * Deliver an skb to a listening sock.
 549  * Socket lock must be held.
 550  * We then queue the skb to the right connected sock (if any).
 551  */
 552 static int pep_do_rcv(struct sock *sk, struct sk_buff *skb)
 553 {
 554         struct pep_sock *pn = pep_sk(sk);
 555         struct sock *sknode;
 556         struct pnpipehdr *hdr = pnp_hdr(skb);
 557         struct sockaddr_pn dst;
 558         int err = NET_RX_SUCCESS;
 559         u8 pipe_handle;
 560
 561         if (!pskb_may_pull(skb, sizeof(*hdr)))
 562                 goto drop;
 563
 564         hdr = pnp_hdr(skb);
 565         pipe_handle = hdr->pipe_handle;
 566         if (pipe_handle == PN_PIPE_INVALID_HANDLE)
 567                 goto drop;
 568
 569         pn_skb_get_dst_sockaddr(skb, &dst);
 570
 571         /* Look for an existing pipe handle */
 572         sknode = pep_find_pipe(&pn->hlist, &dst, pipe_handle);
 573         if (sknode)
 574                 return sk_receive_skb(sknode, skb, 1);
 575
 576         /* Look for a pipe handle pending accept */
 577         sknode = pep_find_pipe(&pn->ackq, &dst, pipe_handle);
 578         if (sknode) {
 579                 sock_put(sknode);
 580                 if (net_ratelimit())
 581                         printk(KERN_WARNING"Phonet unconnected PEP ignored");
 582                 err = NET_RX_DROP;
 583                 goto drop;
 584         }
 585
 586         switch (hdr->message_id) {
 587         case PNS_PEP_CONNECT_REQ:
 588                 err = pep_connreq_rcv(sk, skb);
 589                 break;
 590
 591         case PNS_PEP_DISCONNECT_REQ:
 592                 pep_reply(sk, skb, PN_PIPE_NO_ERROR, NULL, 0, GFP_ATOMIC);
 593                 break;
 594
 595         case PNS_PEP_CTRL_REQ:
 596                 pep_ctrlreq_error(sk, skb, PN_PIPE_INVALID_HANDLE, GFP_ATOMIC);
 597                 break;
 598
 599         case PNS_PEP_RESET_REQ:
 600         case PNS_PEP_ENABLE_REQ:
 601         case PNS_PEP_DISABLE_REQ:
 602                 /* invalid handle is not even allowed here! */
 603         default:
 604                 err = NET_RX_DROP;
 605         }
 606 drop:
 607         kfree_skb(skb);
 608         return err;
 609 }
 610
 611 /* associated socket ceases to exist */
 612 static void pep_sock_close(struct sock *sk, long timeout)
 613 {
 614         struct pep_sock *pn = pep_sk(sk);
 615         int ifindex = 0;
 616
 617         sk_common_release(sk);
 618
 619         lock_sock(sk);
 620         if (sk->sk_state == TCP_LISTEN) {
 621                 /* Destroy the listen queue */
 622                 struct sock *sknode;
 623                 struct hlist_node *p, *n;
 624
 625                 sk_for_each_safe(sknode, p, n, &pn->ackq)
 626                         sk_del_node_init(sknode);
 627                 sk->sk_state = TCP_CLOSE;
 628         }
 629         ifindex = pn->ifindex;
 630         pn->ifindex = 0;
 631         release_sock(sk);
 632
 633         if (ifindex)
 634                 gprs_detach(sk);
 635 }
 636
 637 static int pep_wait_connreq(struct sock *sk, int noblock)
 638 {
 639         struct task_struct *tsk = current;
 640         struct pep_sock *pn = pep_sk(sk);
 641         long timeo = sock_rcvtimeo(sk, noblock);
 642
 643         for (;;) {
 644                 DEFINE_WAIT(wait);
 645
 646                 if (sk->sk_state != TCP_LISTEN)
 647                         return -EINVAL;
 648                 if (!hlist_empty(&pn->ackq))
 649                         break;
 650                 if (!timeo)
 651                         return -EWOULDBLOCK;
 652                 if (signal_pending(tsk))
 653                         return sock_intr_errno(timeo);
 654
 655                 prepare_to_wait_exclusive(&sk->sk_socket->wait, &wait,
 656                                                 TASK_INTERRUPTIBLE);
 657                 release_sock(sk);
 658                 timeo = schedule_timeout(timeo);
 659                 lock_sock(sk);
 660                 finish_wait(&sk->sk_socket->wait, &wait);
 661         }
 662
 663         return 0;
 664 }
 665
 666 static struct sock *pep_sock_accept(struct sock *sk, int flags, int *errp)
 667 {
 668         struct pep_sock *pn = pep_sk(sk);
 669         struct sock *newsk = NULL;
 670         struct sk_buff *oskb;
 671         int err;
 672
 673         lock_sock(sk);
 674         err = pep_wait_connreq(sk, flags & O_NONBLOCK);
 675         if (err)
 676                 goto out;
 677
 678         newsk = __sk_head(&pn->ackq);
 679
 680         oskb = skb_dequeue(&newsk->sk_receive_queue);
 681         err = pep_accept_conn(newsk, oskb);
 682         if (err) {
 683                 skb_queue_head(&newsk->sk_receive_queue, oskb);
 684                 newsk = NULL;
 685                 goto out;
 686         }
 687
 688         sock_hold(sk);
 689         pep_sk(newsk)->listener = sk;
 690
 691         sock_hold(newsk);
 692         sk_del_node_init(newsk);
 693         sk_acceptq_removed(sk);
 694         sk_add_node(newsk, &pn->hlist);
 695         __sock_put(newsk);
 696
 697 out:
 698         release_sock(sk);
 699         *errp = err;
 700         return newsk;
 701 }
 702
 703 static int pep_ioctl(struct sock *sk, int cmd, unsigned long arg)
 704 {
 705         struct pep_sock *pn = pep_sk(sk);
 706         int answ;
 707
 708         switch (cmd) {
 709         case SIOCINQ:
 710                 if (sk->sk_state == TCP_LISTEN)
 711                         return -EINVAL;
 712
 713                 lock_sock(sk);
 714                 if (sock_flag(sk, SOCK_URGINLINE)
 715                  && !skb_queue_empty(&pn->ctrlreq_queue))
 716                         answ = skb_peek(&pn->ctrlreq_queue)->len;
 717                 else if (!skb_queue_empty(&sk->sk_receive_queue))
 718                         answ = skb_peek(&sk->sk_receive_queue)->len;
 719                 else
 720                         answ = 0;
 721                 release_sock(sk);
 722                 return put_user(answ, (int __user *)arg);
 723         }
 724
 725         return -ENOIOCTLCMD;
 726 }
 727
 728 static int pep_init(struct sock *sk)
 729 {
 730         struct pep_sock *pn = pep_sk(sk);
 731
 732         INIT_HLIST_HEAD(&pn->ackq);
 733         INIT_HLIST_HEAD(&pn->hlist);
 734         skb_queue_head_init(&pn->ctrlreq_queue);
 735         pn->pipe_handle = PN_PIPE_INVALID_HANDLE;
 736         return 0;
 737 }
 738
 739 static int pep_setsockopt(struct sock *sk, int level, int optname,
 740                                 char __user *optval, int optlen)
 741 {
 742         struct pep_sock *pn = pep_sk(sk);
 743         int val = 0, err = 0;
 744
 745         if (level != SOL_PNPIPE)
 746                 return -ENOPROTOOPT;
 747         if (optlen >= sizeof(int)) {
 748                 if (get_user(val, (int __user *) optval))
 749                         return -EFAULT;
 750         }
 751
 752         lock_sock(sk);
 753         switch (optname) {
 754         case PNPIPE_ENCAP:
 755                 if (val && val != PNPIPE_ENCAP_IP) {
 756                         err = -EINVAL;
 757                         break;
 758                 }
 759                 if (!pn->ifindex == !val)
 760                         break; /* Nothing to do! */
 761                 if (!capable(CAP_NET_ADMIN)) {
 762                         err = -EPERM;
 763                         break;
 764                 }
 765                 if (val) {
 766                         release_sock(sk);
 767                         err = gprs_attach(sk);
 768                         if (err > 0) {
 769                                 pn->ifindex = err;
 770                                 err = 0;
 771                         }
 772                 } else {
 773                         pn->ifindex = 0;
 774                         release_sock(sk);
 775                         gprs_detach(sk);
 776                         err = 0;
 777                 }
 778                 goto out_norel;
 779         default:
 780                 err = -ENOPROTOOPT;
 781         }
 782         release_sock(sk);
 783
 784 out_norel:
 785         return err;
 786 }
 787
 788 static int pep_getsockopt(struct sock *sk, int level, int optname,
 789                                 char __user *optval, int __user *optlen)
 790 {
 791         struct pep_sock *pn = pep_sk(sk);
 792         int len, val;
 793
 794         if (level != SOL_PNPIPE)
 795                 return -ENOPROTOOPT;
 796         if (get_user(len, optlen))
 797                 return -EFAULT;
 798
 799         switch (optname) {
 800         case PNPIPE_ENCAP:
 801                 val = pn->ifindex ? PNPIPE_ENCAP_IP : PNPIPE_ENCAP_NONE;
 802                 break;
 803         case PNPIPE_IFINDEX:
 804                 val = pn->ifindex;
 805                 break;
 806         default:
 807                 return -ENOPROTOOPT;
 808         }
 809
 810         len = min_t(unsigned int, sizeof(int), len);
 811         if (put_user(len, optlen))
 812                 return -EFAULT;
 813         if (put_user(val, (int __user *) optval))
 814                 return -EFAULT;
 815         return 0;
 816 }
 817
 818 static int pipe_skb_send(struct sock *sk, struct sk_buff *skb)
 819 {
 820         struct pep_sock *pn = pep_sk(sk);
 821         struct pnpipehdr *ph;
 822
 823         if (pn_flow_safe(pn->tx_fc) &&
 824             !atomic_add_unless(&pn->tx_credits, -1, 0)) {
 825                 kfree_skb(skb);
 826                 return -ENOBUFS;
 827         }
 828
 829         skb_push(skb, 3);
 830         skb_reset_transport_header(skb);
 831         ph = pnp_hdr(skb);
 832         ph->utid = 0;
 833         ph->message_id = PNS_PIPE_DATA;
 834         ph->pipe_handle = pn->pipe_handle;
 835
 836         return pn_skb_send(sk, skb, &pipe_srv);
 837 }
 838
 839 static int pep_sendmsg(struct kiocb *iocb, struct sock *sk,
 840                         struct msghdr *msg, size_t len)
 841 {
 842         struct pep_sock *pn = pep_sk(sk);
 843         struct sk_buff *skb = NULL;
 844         long timeo;
 845         int flags = msg->msg_flags;
 846         int err, done;
 847
 848         if (msg->msg_flags & MSG_OOB || !(msg->msg_flags & MSG_EOR))
 849                 return -EOPNOTSUPP;
 850
 851         lock_sock(sk);
 852         timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT);
 853         if ((1 << sk->sk_state) & (TCPF_LISTEN|TCPF_CLOSE)) {
 854                 err = -ENOTCONN;
 855                 goto out;
 856         }
 857         if (sk->sk_state != TCP_ESTABLISHED) {
 858                 /* Wait until the pipe gets to enabled state */
 859 disabled:
 860                 err = sk_stream_wait_connect(sk, &timeo);
 861                 if (err)
 862                         goto out;
 863
 864                 if (sk->sk_state == TCP_CLOSE_WAIT) {
 865                         err = -ECONNRESET;
 866                         goto out;
 867                 }
 868         }
 869         BUG_ON(sk->sk_state != TCP_ESTABLISHED);
 870
 871         /* Wait until flow control allows TX */
 872         done = atomic_read(&pn->tx_credits);
 873         while (!done) {
 874                 DEFINE_WAIT(wait);
 875
 876                 if (!timeo) {
 877                         err = -EAGAIN;
 878                         goto out;
 879                 }
 880                 if (signal_pending(current)) {
 881                         err = sock_intr_errno(timeo);
 882                         goto out;
 883                 }
 884
 885                 prepare_to_wait(&sk->sk_socket->wait, &wait,
 886                                 TASK_INTERRUPTIBLE);
 887                 done = sk_wait_event(sk, &timeo, atomic_read(&pn->tx_credits));
 888                 finish_wait(&sk->sk_socket->wait, &wait);
 889
 890                 if (sk->sk_state != TCP_ESTABLISHED)
 891                         goto disabled;
 892         }
 893
 894         if (!skb) {
 895                 skb = sock_alloc_send_skb(sk, MAX_PNPIPE_HEADER + len,
 896                                                 flags & MSG_DONTWAIT, &err);
 897                 if (skb == NULL)
 898                         goto out;
 899                 skb_reserve(skb, MAX_PHONET_HEADER + 3);
 900
 901                 if (sk->sk_state != TCP_ESTABLISHED ||
 902                     !atomic_read(&pn->tx_credits))
 903                         goto disabled; /* sock_alloc_send_skb might sleep */
 904         }
 905
 906         err = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len);
 907         if (err < 0)
 908                 goto out;
 909
 910         err = pipe_skb_send(sk, skb);
 911         if (err >= 0)
 912                 err = len; /* success! */
 913         skb = NULL;
 914 out:
 915         release_sock(sk);
 916         kfree_skb(skb);
 917         return err;
 918 }
 919
 920 int pep_writeable(struct sock *sk)
 921 {
 922         struct pep_sock *pn = pep_sk(sk);
 923
 924         return atomic_read(&pn->tx_credits);
 925 }
 926
 927 int pep_write(struct sock *sk, struct sk_buff *skb)
 928 {
 929         struct sk_buff *rskb, *fs;
 930         int flen = 0;
 931
 932         rskb = alloc_skb(MAX_PNPIPE_HEADER, GFP_ATOMIC);
 933         if (!rskb) {
 934                 kfree_skb(skb);
 935                 return -ENOMEM;
 936         }
 937         skb_shinfo(rskb)->frag_list = skb;
 938         rskb->len += skb->len;
 939         rskb->data_len += rskb->len;
 940         rskb->truesize += rskb->len;
 941
 942         /* Avoid nested fragments */
 943         for (fs = skb_shinfo(skb)->frag_list; fs; fs = fs->next)
 944                 flen += fs->len;
 945         skb->next = skb_shinfo(skb)->frag_list;
 946         skb_shinfo(skb)->frag_list = NULL;
 947         skb->len -= flen;
 948         skb->data_len -= flen;
 949         skb->truesize -= flen;
 950
 951         skb_reserve(rskb, MAX_PHONET_HEADER + 3);
 952         return pipe_skb_send(sk, rskb);
 953 }
 954
 955 struct sk_buff *pep_read(struct sock *sk)
 956 {
 957         struct sk_buff *skb = skb_dequeue(&sk->sk_receive_queue);
 958
 959         if (sk->sk_state == TCP_ESTABLISHED)
 960                 pipe_grant_credits(sk);
 961         return skb;
 962 }
 963
 964 static int pep_recvmsg(struct kiocb *iocb, struct sock *sk,
 965                         struct msghdr *msg, size_t len, int noblock,
 966                         int flags, int *addr_len)
 967 {
 968         struct sk_buff *skb;
 969         int err;
 970
 971         if (unlikely(1 << sk->sk_state & (TCPF_LISTEN | TCPF_CLOSE)))
 972                 return -ENOTCONN;
 973
 974         if ((flags & MSG_OOB) || sock_flag(sk, SOCK_URGINLINE)) {
 975                 /* Dequeue and acknowledge control request */
 976                 struct pep_sock *pn = pep_sk(sk);
 977
 978                 skb = skb_dequeue(&pn->ctrlreq_queue);
 979                 if (skb) {
 980                         pep_ctrlreq_error(sk, skb, PN_PIPE_NO_ERROR,
 981                                                 GFP_KERNEL);
 982                         msg->msg_flags |= MSG_OOB;
 983                         goto copy;
 984                 }
 985                 if (flags & MSG_OOB)
 986                         return -EINVAL;
 987         }
 988
 989         skb = skb_recv_datagram(sk, flags, noblock, &err);
 990         lock_sock(sk);
 991         if (skb == NULL) {
 992                 if (err == -ENOTCONN && sk->sk_state == TCP_CLOSE_WAIT)
 993                         err = -ECONNRESET;
 994                 release_sock(sk);
 995                 return err;
 996         }
 997
 998         if (sk->sk_state == TCP_ESTABLISHED)
 999                 pipe_grant_credits(sk);
1000         release_sock(sk);
1001 copy:
1002         msg->msg_flags |= MSG_EOR;
1003         if (skb->len > len)
1004                 msg->msg_flags |= MSG_TRUNC;
1005         else
1006                 len = skb->len;
1007
1008         err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, len);
1009         if (!err)
1010                 err = (flags & MSG_TRUNC) ? skb->len : len;
1011
1012         skb_free_datagram(sk, skb);
1013         return err;
1014 }
1015
1016 static void pep_sock_unhash(struct sock *sk)
1017 {
1018         struct pep_sock *pn = pep_sk(sk);
1019         struct sock *skparent = NULL;
1020
1021         lock_sock(sk);
1022         if ((1 << sk->sk_state) & ~(TCPF_CLOSE|TCPF_LISTEN)) {
1023                 skparent = pn->listener;
1024                 sk_del_node_init(sk);
1025                 release_sock(sk);
1026
1027                 sk = skparent;
1028                 pn = pep_sk(skparent);
1029                 lock_sock(sk);
1030         }
1031         /* Unhash a listening sock only when it is closed
1032          * and all of its active connected pipes are closed. */
1033         if (hlist_empty(&pn->hlist))
1034                 pn_sock_unhash(&pn->pn_sk.sk);
1035         release_sock(sk);
1036
1037         if (skparent)
1038                 sock_put(skparent);
1039 }
1040
1041 static struct proto pep_proto = {
1042         .close          = pep_sock_close,
1043         .accept         = pep_sock_accept,
1044         .ioctl          = pep_ioctl,
1045         .init           = pep_init,
1046         .setsockopt     = pep_setsockopt,
1047         .getsockopt     = pep_getsockopt,
1048         .sendmsg        = pep_sendmsg,
1049         .recvmsg        = pep_recvmsg,
1050         .backlog_rcv    = pep_do_rcv,
1051         .hash           = pn_sock_hash,
1052         .unhash         = pep_sock_unhash,
1053         .get_port       = pn_sock_get_port,
1054         .obj_size       = sizeof(struct pep_sock),
1055         .owner          = THIS_MODULE,
1056         .name           = "PNPIPE",
1057 };
1058
1059 static struct phonet_protocol pep_pn_proto = {
1060         .ops            = &phonet_stream_ops,
1061         .prot           = &pep_proto,
1062         .sock_type      = SOCK_SEQPACKET,
1063 };
1064
1065 static int __init pep_register(void)
1066 {
1067         return phonet_proto_register(PN_PROTO_PIPE, &pep_pn_proto);
1068 }
1069
1070 static void __exit pep_unregister(void)
1071 {
1072         phonet_proto_unregister(PN_PROTO_PIPE, &pep_pn_proto);
1073 }
1074
1075 module_init(pep_register);
1076 module_exit(pep_unregister);
1077 MODULE_AUTHOR("Remi Denis-Courmont, Nokia");
1078 MODULE_DESCRIPTION("Phonet pipe protocol");
1079 MODULE_LICENSE("GPL");
1080 MODULE_ALIAS_NET_PF_PROTO(PF_PHONET, PN_PROTO_PIPE);