SAFE public projects git trees. - safe/jmp/linux-2.6/blob - 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
  35 /* sk_state values:
  36  * TCP_CLOSE            sock not in use yet
  37  * TCP_CLOSE_WAIT       disconnected pipe
  38  * TCP_LISTEN           listening pipe endpoint
  39  * TCP_SYN_RECV         connected pipe in disabled state
  40  * TCP_ESTABLISHED      connected pipe in enabled state
  41  *
  42  * pep_sock locking:
  43  *  - sk_state, ackq, hlist: sock lock needed
  44  *  - listener: read only
  45  *  - pipe_handle: read only
  46  */
  47
  48 #define CREDITS_MAX     10
  49 #define CREDITS_THR     7
  50
  51 static const struct sockaddr_pn pipe_srv = {
  52         .spn_family = AF_PHONET,
  53         .spn_resource = 0xD9, /* pipe service */
  54 };
  55
  56 #define pep_sb_size(s) (((s) + 5) & ~3) /* 2-bytes head, 32-bits aligned */
  57
  58 /* Get the next TLV sub-block. */
  59 static unsigned char *pep_get_sb(struct sk_buff *skb, u8 *ptype, u8 *plen,
  60                                         void *buf)
  61 {
  62         void *data = NULL;
  63         struct {
  64                 u8 sb_type;
  65                 u8 sb_len;
  66         } *ph, h;
  67         int buflen = *plen;
  68
  69         ph = skb_header_pointer(skb, 0, 2, &h);
  70         if (ph == NULL || ph->sb_len < 2 || !pskb_may_pull(skb, ph->sb_len))
  71                 return NULL;
  72         ph->sb_len -= 2;
  73         *ptype = ph->sb_type;
  74         *plen = ph->sb_len;
  75
  76         if (buflen > ph->sb_len)
  77                 buflen = ph->sb_len;
  78         data = skb_header_pointer(skb, 2, buflen, buf);
  79         __skb_pull(skb, 2 + ph->sb_len);
  80         return data;
  81 }
  82
  83 static int pep_reply(struct sock *sk, struct sk_buff *oskb,
  84                         u8 code, const void *data, int len, gfp_t priority)
  85 {
  86         const struct pnpipehdr *oph = pnp_hdr(oskb);
  87         struct pnpipehdr *ph;
  88         struct sk_buff *skb;
  89
  90         skb = alloc_skb(MAX_PNPIPE_HEADER + len, priority);
  91         if (!skb)
  92                 return -ENOMEM;
  93         skb_set_owner_w(skb, sk);
  94
  95         skb_reserve(skb, MAX_PNPIPE_HEADER);
  96         __skb_put(skb, len);
  97         skb_copy_to_linear_data(skb, data, len);
  98         __skb_push(skb, sizeof(*ph));
  99         skb_reset_transport_header(skb);
 100         ph = pnp_hdr(skb);
 101         ph->utid = oph->utid;
 102         ph->message_id = oph->message_id + 1; /* REQ -> RESP */
 103         ph->pipe_handle = oph->pipe_handle;
 104         ph->error_code = code;
 105
 106         return pn_skb_send(sk, skb, &pipe_srv);
 107 }
 108
 109 #define PAD 0x00
 110 static int pep_accept_conn(struct sock *sk, struct sk_buff *skb)
 111 {
 112         static const u8 data[20] = {
 113                 PAD, PAD, PAD, 2 /* sub-blocks */,
 114                 PN_PIPE_SB_REQUIRED_FC_TX, pep_sb_size(5), 3, PAD,
 115                         PN_MULTI_CREDIT_FLOW_CONTROL,
 116                         PN_ONE_CREDIT_FLOW_CONTROL,
 117                         PN_LEGACY_FLOW_CONTROL,
 118                         PAD,
 119                 PN_PIPE_SB_PREFERRED_FC_RX, pep_sb_size(5), 3, PAD,
 120                         PN_MULTI_CREDIT_FLOW_CONTROL,
 121                         PN_ONE_CREDIT_FLOW_CONTROL,
 122                         PN_LEGACY_FLOW_CONTROL,
 123                         PAD,
 124         };
 125
 126         might_sleep();
 127         return pep_reply(sk, skb, PN_PIPE_NO_ERROR, data, sizeof(data),
 128                                 GFP_KERNEL);
 129 }
 130
 131 static int pep_reject_conn(struct sock *sk, struct sk_buff *skb, u8 code)
 132 {
 133         static const u8 data[4] = { PAD, PAD, PAD, 0 /* sub-blocks */ };
 134         WARN_ON(code == PN_PIPE_NO_ERROR);
 135         return pep_reply(sk, skb, code, data, sizeof(data), GFP_ATOMIC);
 136 }
 137
 138 /* Control requests are not sent by the pipe service and have a specific
 139  * message format. */
 140 static int pep_ctrlreq_error(struct sock *sk, struct sk_buff *oskb, u8 code,
 141                                 gfp_t priority)
 142 {
 143         const struct pnpipehdr *oph = pnp_hdr(oskb);
 144         struct sk_buff *skb;
 145         struct pnpipehdr *ph;
 146         struct sockaddr_pn dst;
 147
 148         skb = alloc_skb(MAX_PNPIPE_HEADER + 4, priority);
 149         if (!skb)
 150                 return -ENOMEM;
 151         skb_set_owner_w(skb, sk);
 152
 153         skb_reserve(skb, MAX_PHONET_HEADER);
 154         ph = (struct pnpipehdr *)skb_put(skb, sizeof(*ph) + 4);
 155
 156         ph->utid = oph->utid;
 157         ph->message_id = PNS_PEP_CTRL_RESP;
 158         ph->pipe_handle = oph->pipe_handle;
 159         ph->data[0] = oph->data[1]; /* CTRL id */
 160         ph->data[1] = oph->data[0]; /* PEP type */
 161         ph->data[2] = code; /* error code, at an usual offset */
 162         ph->data[3] = PAD;
 163         ph->data[4] = PAD;
 164
 165         pn_skb_get_src_sockaddr(oskb, &dst);
 166         return pn_skb_send(sk, skb, &dst);
 167 }
 168
 169 static int pipe_snd_status(struct sock *sk, u8 type, u8 status, gfp_t priority)
 170 {
 171         struct pep_sock *pn = pep_sk(sk);
 172         struct pnpipehdr *ph;
 173         struct sk_buff *skb;
 174
 175         skb = alloc_skb(MAX_PNPIPE_HEADER + 4, priority);
 176         if (!skb)
 177                 return -ENOMEM;
 178         skb_set_owner_w(skb, sk);
 179
 180         skb_reserve(skb, MAX_PNPIPE_HEADER + 4);
 181         __skb_push(skb, sizeof(*ph) + 4);
 182         skb_reset_transport_header(skb);
 183         ph = pnp_hdr(skb);
 184         ph->utid = 0;
 185         ph->message_id = PNS_PEP_STATUS_IND;
 186         ph->pipe_handle = pn->pipe_handle;
 187         ph->pep_type = PN_PEP_TYPE_COMMON;
 188         ph->data[1] = type;
 189         ph->data[2] = PAD;
 190         ph->data[3] = PAD;
 191         ph->data[4] = status;
 192
 193         return pn_skb_send(sk, skb, &pipe_srv);
 194 }
 195
 196 /* Send our RX flow control information to the sender.
 197  * Socket must be locked. */
 198 static void pipe_grant_credits(struct sock *sk)
 199 {
 200         struct pep_sock *pn = pep_sk(sk);
 201
 202         BUG_ON(sk->sk_state != TCP_ESTABLISHED);
 203
 204         switch (pn->rx_fc) {
 205         case PN_LEGACY_FLOW_CONTROL: /* TODO */
 206                 break;
 207         case PN_ONE_CREDIT_FLOW_CONTROL:
 208                 pipe_snd_status(sk, PN_PEP_IND_FLOW_CONTROL,
 209                                 PEP_IND_READY, GFP_ATOMIC);
 210                 pn->rx_credits = 1;
 211                 break;
 212         case PN_MULTI_CREDIT_FLOW_CONTROL:
 213                 if ((pn->rx_credits + CREDITS_THR) > CREDITS_MAX)
 214                         break;
 215                 if (pipe_snd_status(sk, PN_PEP_IND_ID_MCFC_GRANT_CREDITS,
 216                                         CREDITS_MAX - pn->rx_credits,
 217                                         GFP_ATOMIC) == 0)
 218                         pn->rx_credits = CREDITS_MAX;
 219                 break;
 220         }
 221 }
 222
 223 static int pipe_rcv_status(struct sock *sk, struct sk_buff *skb)
 224 {
 225         struct pep_sock *pn = pep_sk(sk);
 226         struct pnpipehdr *hdr = pnp_hdr(skb);
 227
 228         if (!pskb_may_pull(skb, sizeof(*hdr) + 4))
 229                 return -EINVAL;
 230
 231         if (hdr->data[0] != PN_PEP_TYPE_COMMON) {
 232                 LIMIT_NETDEBUG(KERN_DEBUG"Phonet unknown PEP type: %u\n",
 233                                 (unsigned)hdr->data[0]);
 234                 return -EOPNOTSUPP;
 235         }
 236
 237         switch (hdr->data[1]) {
 238         case PN_PEP_IND_FLOW_CONTROL:
 239                 switch (pn->tx_fc) {
 240                 case PN_LEGACY_FLOW_CONTROL:
 241                         switch (hdr->data[4]) {
 242                         case PEP_IND_BUSY:
 243                                 pn->tx_credits = 0;
 244                                 break;
 245                         case PEP_IND_READY:
 246                                 pn->tx_credits = 1;
 247                                 break;
 248                         }
 249                         break;
 250                 case PN_ONE_CREDIT_FLOW_CONTROL:
 251                         if (hdr->data[4] == PEP_IND_READY)
 252                                 pn->tx_credits = 1;
 253                         break;
 254                 }
 255                 break;
 256
 257         case PN_PEP_IND_ID_MCFC_GRANT_CREDITS:
 258                 if (pn->tx_fc != PN_MULTI_CREDIT_FLOW_CONTROL)
 259                         break;
 260                 if (pn->tx_credits + hdr->data[4] > 0xff)
 261                         pn->tx_credits = 0xff;
 262                 else
 263                         pn->tx_credits += hdr->data[4];
 264                 break;
 265
 266         default:
 267                 LIMIT_NETDEBUG(KERN_DEBUG"Phonet unknown PEP indication: %u\n",
 268                                 (unsigned)hdr->data[1]);
 269                 return -EOPNOTSUPP;
 270         }
 271         if (pn->tx_credits)
 272                 sk->sk_write_space(sk);
 273         return 0;
 274 }
 275
 276 static int pipe_rcv_created(struct sock *sk, struct sk_buff *skb)
 277 {
 278         struct pep_sock *pn = pep_sk(sk);
 279         struct pnpipehdr *hdr = pnp_hdr(skb);
 280         u8 n_sb = hdr->data[0];
 281
 282         pn->rx_fc = pn->tx_fc = PN_LEGACY_FLOW_CONTROL;
 283         __skb_pull(skb, sizeof(*hdr));
 284         while (n_sb > 0) {
 285                 u8 type, buf[2], len = sizeof(buf);
 286                 u8 *data = pep_get_sb(skb, &type, &len, buf);
 287
 288                 if (data == NULL)
 289                         return -EINVAL;
 290                 switch (type) {
 291                 case PN_PIPE_SB_NEGOTIATED_FC:
 292                         if (len < 2 || (data[0] | data[1]) > 3)
 293                                 break;
 294                         pn->tx_fc = data[0] & 3;
 295                         pn->rx_fc = data[1] & 3;
 296                         break;
 297                 }
 298                 n_sb--;
 299         }
 300         return 0;
 301 }
 302
 303 /* Queue an skb to a connected sock.
 304  * Socket lock must be held. */
 305 static int pipe_do_rcv(struct sock *sk, struct sk_buff *skb)
 306 {
 307         struct pep_sock *pn = pep_sk(sk);
 308         struct pnpipehdr *hdr = pnp_hdr(skb);
 309         struct sk_buff_head *queue;
 310         int err = 0;
 311
 312         BUG_ON(sk->sk_state == TCP_CLOSE_WAIT);
 313
 314         switch (hdr->message_id) {
 315         case PNS_PEP_CONNECT_REQ:
 316                 pep_reject_conn(sk, skb, PN_PIPE_ERR_PEP_IN_USE);
 317                 break;
 318
 319         case PNS_PEP_DISCONNECT_REQ:
 320                 pep_reply(sk, skb, PN_PIPE_NO_ERROR, NULL, 0, GFP_ATOMIC);
 321                 sk->sk_state = TCP_CLOSE_WAIT;
 322                 if (!sock_flag(sk, SOCK_DEAD))
 323                         sk->sk_state_change(sk);
 324                 break;
 325
 326         case PNS_PEP_ENABLE_REQ:
 327                 /* Wait for PNS_PIPE_(ENABLED|REDIRECTED)_IND */
 328                 pep_reply(sk, skb, PN_PIPE_NO_ERROR, NULL, 0, GFP_ATOMIC);
 329                 break;
 330
 331         case PNS_PEP_RESET_REQ:
 332                 switch (hdr->state_after_reset) {
 333                 case PN_PIPE_DISABLE:
 334                         pn->init_enable = 0;
 335                         break;
 336                 case PN_PIPE_ENABLE:
 337                         pn->init_enable = 1;
 338                         break;
 339                 default: /* not allowed to send an error here!? */
 340                         err = -EINVAL;
 341                         goto out;
 342                 }
 343                 /* fall through */
 344         case PNS_PEP_DISABLE_REQ:
 345                 pn->tx_credits = 0;
 346                 pep_reply(sk, skb, PN_PIPE_NO_ERROR, NULL, 0, GFP_ATOMIC);
 347                 break;
 348
 349         case PNS_PEP_CTRL_REQ:
 350                 if (skb_queue_len(&pn->ctrlreq_queue) >= PNPIPE_CTRLREQ_MAX)
 351                         break;
 352                 __skb_pull(skb, 4);
 353                 queue = &pn->ctrlreq_queue;
 354                 goto queue;
 355
 356         case PNS_PIPE_DATA:
 357                 __skb_pull(skb, 3); /* Pipe data header */
 358                 if (!pn_flow_safe(pn->rx_fc)) {
 359                         err = sock_queue_rcv_skb(sk, skb);
 360                         if (!err)
 361                                 return 0;
 362                         break;
 363                 }
 364
 365                 if (pn->rx_credits == 0) {
 366                         err = -ENOBUFS;
 367                         break;
 368                 }
 369                 pn->rx_credits--;
 370                 queue = &sk->sk_receive_queue;
 371                 goto queue;
 372
 373         case PNS_PEP_STATUS_IND:
 374                 pipe_rcv_status(sk, skb);
 375                 break;
 376
 377         case PNS_PIPE_REDIRECTED_IND:
 378                 err = pipe_rcv_created(sk, skb);
 379                 break;
 380
 381         case PNS_PIPE_CREATED_IND:
 382                 err = pipe_rcv_created(sk, skb);
 383                 if (err)
 384                         break;
 385                 /* fall through */
 386         case PNS_PIPE_RESET_IND:
 387                 if (!pn->init_enable)
 388                         break;
 389                 /* fall through */
 390         case PNS_PIPE_ENABLED_IND:
 391                 if (!pn_flow_safe(pn->tx_fc)) {
 392                         pn->tx_credits = 1;
 393                         sk->sk_write_space(sk);
 394                 }
 395                 if (sk->sk_state == TCP_ESTABLISHED)
 396                         break; /* Nothing to do */
 397                 sk->sk_state = TCP_ESTABLISHED;
 398                 pipe_grant_credits(sk);
 399                 break;
 400
 401         case PNS_PIPE_DISABLED_IND:
 402                 sk->sk_state = TCP_SYN_RECV;
 403                 pn->rx_credits = 0;
 404                 break;
 405
 406         default:
 407                 LIMIT_NETDEBUG(KERN_DEBUG"Phonet unknown PEP message: %u\n",
 408                                 hdr->message_id);
 409                 err = -EINVAL;
 410         }
 411 out:
 412         kfree_skb(skb);
 413         return err;
 414
 415 queue:
 416         skb->dev = NULL;
 417         skb_set_owner_r(skb, sk);
 418         err = skb->len;
 419         skb_queue_tail(queue, skb);
 420         if (!sock_flag(sk, SOCK_DEAD))
 421                 sk->sk_data_ready(sk, err);
 422         return 0;
 423 }
 424
 425 /* Destroy connected sock. */
 426 static void pipe_destruct(struct sock *sk)
 427 {
 428         struct pep_sock *pn = pep_sk(sk);
 429
 430         skb_queue_purge(&sk->sk_receive_queue);
 431         skb_queue_purge(&pn->ctrlreq_queue);
 432 }
 433
 434 static int pep_connreq_rcv(struct sock *sk, struct sk_buff *skb)
 435 {
 436         struct sock *newsk;
 437         struct pep_sock *newpn, *pn = pep_sk(sk);
 438         struct pnpipehdr *hdr;
 439         struct sockaddr_pn dst;
 440         u16 peer_type;
 441         u8 pipe_handle, enabled, n_sb;
 442
 443         if (!pskb_pull(skb, sizeof(*hdr) + 4))
 444                 return -EINVAL;
 445
 446         hdr = pnp_hdr(skb);
 447         pipe_handle = hdr->pipe_handle;
 448         switch (hdr->state_after_connect) {
 449         case PN_PIPE_DISABLE:
 450                 enabled = 0;
 451                 break;
 452         case PN_PIPE_ENABLE:
 453                 enabled = 1;
 454                 break;
 455         default:
 456                 pep_reject_conn(sk, skb, PN_PIPE_ERR_INVALID_PARAM);
 457                 return -EINVAL;
 458         }
 459         peer_type = hdr->other_pep_type << 8;
 460
 461         if (unlikely(sk->sk_state != TCP_LISTEN) || sk_acceptq_is_full(sk)) {
 462                 pep_reject_conn(sk, skb, PN_PIPE_ERR_PEP_IN_USE);
 463                 return -ENOBUFS;
 464         }
 465
 466         /* Parse sub-blocks (options) */
 467         n_sb = hdr->data[4];
 468         while (n_sb > 0) {
 469                 u8 type, buf[1], len = sizeof(buf);
 470                 const u8 *data = pep_get_sb(skb, &type, &len, buf);
 471
 472                 if (data == NULL)
 473                         return -EINVAL;
 474                 switch (type) {
 475                 case PN_PIPE_SB_CONNECT_REQ_PEP_SUB_TYPE:
 476                         if (len < 1)
 477                                 return -EINVAL;
 478                         peer_type = (peer_type & 0xff00) | data[0];
 479                         break;
 480                 }
 481                 n_sb--;
 482         }
 483
 484         skb = skb_clone(skb, GFP_ATOMIC);
 485         if (!skb)
 486                 return -ENOMEM;
 487
 488         /* Create a new to-be-accepted sock */
 489         newsk = sk_alloc(sock_net(sk), PF_PHONET, GFP_ATOMIC, sk->sk_prot);
 490         if (!newsk) {
 491                 kfree_skb(skb);
 492                 return -ENOMEM;
 493         }
 494         sock_init_data(NULL, newsk);
 495         newsk->sk_state = TCP_SYN_RECV;
 496         newsk->sk_backlog_rcv = pipe_do_rcv;
 497         newsk->sk_protocol = sk->sk_protocol;
 498         newsk->sk_destruct = pipe_destruct;
 499
 500         newpn = pep_sk(newsk);
 501         pn_skb_get_dst_sockaddr(skb, &dst);
 502         newpn->pn_sk.sobject = pn_sockaddr_get_object(&dst);
 503         newpn->pn_sk.resource = pn->pn_sk.resource;
 504         skb_queue_head_init(&newpn->ctrlreq_queue);
 505         newpn->pipe_handle = pipe_handle;
 506         newpn->peer_type = peer_type;
 507         newpn->rx_credits = newpn->tx_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
 616         sk_common_release(sk);
 617
 618         lock_sock(sk);
 619         if (sk->sk_state == TCP_LISTEN) {
 620                 /* Destroy the listen queue */
 621                 struct sock *sknode;
 622                 struct hlist_node *p, *n;
 623
 624                 sk_for_each_safe(sknode, p, n, &pn->ackq)
 625                         sk_del_node_init(sknode);
 626                 sk->sk_state = TCP_CLOSE;
 627         }
 628         release_sock(sk);
 629 }
 630
 631 static int pep_wait_connreq(struct sock *sk, int noblock)
 632 {
 633         struct task_struct *tsk = current;
 634         struct pep_sock *pn = pep_sk(sk);
 635         long timeo = sock_rcvtimeo(sk, noblock);
 636
 637         for (;;) {
 638                 DEFINE_WAIT(wait);
 639
 640                 if (sk->sk_state != TCP_LISTEN)
 641                         return -EINVAL;
 642                 if (!hlist_empty(&pn->ackq))
 643                         break;
 644                 if (!timeo)
 645                         return -EWOULDBLOCK;
 646                 if (signal_pending(tsk))
 647                         return sock_intr_errno(timeo);
 648
 649                 prepare_to_wait_exclusive(&sk->sk_socket->wait, &wait,
 650                                                 TASK_INTERRUPTIBLE);
 651                 release_sock(sk);
 652                 timeo = schedule_timeout(timeo);
 653                 lock_sock(sk);
 654                 finish_wait(&sk->sk_socket->wait, &wait);
 655         }
 656
 657         return 0;
 658 }
 659
 660 static struct sock *pep_sock_accept(struct sock *sk, int flags, int *errp)
 661 {
 662         struct pep_sock *pn = pep_sk(sk);
 663         struct sock *newsk = NULL;
 664         struct sk_buff *oskb;
 665         int err;
 666
 667         lock_sock(sk);
 668         err = pep_wait_connreq(sk, flags & O_NONBLOCK);
 669         if (err)
 670                 goto out;
 671
 672         newsk = __sk_head(&pn->ackq);
 673
 674         oskb = skb_dequeue(&newsk->sk_receive_queue);
 675         err = pep_accept_conn(newsk, oskb);
 676         if (err) {
 677                 skb_queue_head(&newsk->sk_receive_queue, oskb);
 678                 newsk = NULL;
 679                 goto out;
 680         }
 681
 682         sock_hold(sk);
 683         pep_sk(newsk)->listener = sk;
 684
 685         sock_hold(newsk);
 686         sk_del_node_init(newsk);
 687         sk_acceptq_removed(sk);
 688         sk_add_node(newsk, &pn->hlist);
 689         __sock_put(newsk);
 690
 691 out:
 692         release_sock(sk);
 693         *errp = err;
 694         return newsk;
 695 }
 696
 697 static int pep_ioctl(struct sock *sk, int cmd, unsigned long arg)
 698 {
 699         struct pep_sock *pn = pep_sk(sk);
 700         int answ;
 701
 702         switch (cmd) {
 703         case SIOCINQ:
 704                 if (sk->sk_state == TCP_LISTEN)
 705                         return -EINVAL;
 706
 707                 lock_sock(sk);
 708                 if (sock_flag(sk, SOCK_URGINLINE)
 709                  && !skb_queue_empty(&pn->ctrlreq_queue))
 710                         answ = skb_peek(&pn->ctrlreq_queue)->len;
 711                 else if (!skb_queue_empty(&sk->sk_receive_queue))
 712                         answ = skb_peek(&sk->sk_receive_queue)->len;
 713                 else
 714                         answ = 0;
 715                 release_sock(sk);
 716                 return put_user(answ, (int __user *)arg);
 717         }
 718
 719         return -ENOIOCTLCMD;
 720 }
 721
 722 static int pep_init(struct sock *sk)
 723 {
 724         struct pep_sock *pn = pep_sk(sk);
 725
 726         INIT_HLIST_HEAD(&pn->ackq);
 727         INIT_HLIST_HEAD(&pn->hlist);
 728         skb_queue_head_init(&pn->ctrlreq_queue);
 729         pn->pipe_handle = PN_PIPE_INVALID_HANDLE;
 730         return 0;
 731 }
 732
 733 static int pep_sendmsg(struct kiocb *iocb, struct sock *sk,
 734                         struct msghdr *msg, size_t len)
 735 {
 736         struct pep_sock *pn = pep_sk(sk);
 737         struct sk_buff *skb = NULL;
 738         struct pnpipehdr *ph;
 739         long timeo;
 740         int flags = msg->msg_flags;
 741         int err, done;
 742
 743         if (msg->msg_flags & MSG_OOB || !(msg->msg_flags & MSG_EOR))
 744                 return -EOPNOTSUPP;
 745
 746         lock_sock(sk);
 747         timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT);
 748         if ((1 << sk->sk_state) & (TCPF_LISTEN|TCPF_CLOSE)) {
 749                 err = -ENOTCONN;
 750                 goto out;
 751         }
 752         if (sk->sk_state != TCP_ESTABLISHED) {
 753                 /* Wait until the pipe gets to enabled state */
 754 disabled:
 755                 err = sk_stream_wait_connect(sk, &timeo);
 756                 if (err)
 757                         goto out;
 758
 759                 if (sk->sk_state == TCP_CLOSE_WAIT) {
 760                         err = -ECONNRESET;
 761                         goto out;
 762                 }
 763         }
 764         BUG_ON(sk->sk_state != TCP_ESTABLISHED);
 765
 766         /* Wait until flow control allows TX */
 767         done = pn->tx_credits > 0;
 768         while (!done) {
 769                 DEFINE_WAIT(wait);
 770
 771                 if (!timeo) {
 772                         err = -EAGAIN;
 773                         goto out;
 774                 }
 775                 if (signal_pending(current)) {
 776                         err = sock_intr_errno(timeo);
 777                         goto out;
 778                 }
 779
 780                 prepare_to_wait(&sk->sk_socket->wait, &wait,
 781                                 TASK_INTERRUPTIBLE);
 782                 done = sk_wait_event(sk, &timeo, pn->tx_credits > 0);
 783                 finish_wait(&sk->sk_socket->wait, &wait);
 784
 785                 if (sk->sk_state != TCP_ESTABLISHED)
 786                         goto disabled;
 787         }
 788
 789         if (!skb) {
 790                 skb = sock_alloc_send_skb(sk, MAX_PNPIPE_HEADER + len,
 791                                                 flags & MSG_DONTWAIT, &err);
 792                 if (skb == NULL)
 793                         goto out;
 794                 skb_reserve(skb, MAX_PHONET_HEADER + 3);
 795
 796                 if (sk->sk_state != TCP_ESTABLISHED || !pn->tx_credits)
 797                         goto disabled; /* sock_alloc_send_skb might sleep */
 798         }
 799
 800         err = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len);
 801         if (err < 0)
 802                 goto out;
 803
 804         __skb_push(skb, 3);
 805         skb_reset_transport_header(skb);
 806         ph = pnp_hdr(skb);
 807         ph->utid = 0;
 808         ph->message_id = PNS_PIPE_DATA;
 809         ph->pipe_handle = pn->pipe_handle;
 810         if (pn_flow_safe(pn->tx_fc)) /* credit-based flow control */
 811                 pn->tx_credits--;
 812
 813         err = pn_skb_send(sk, skb, &pipe_srv);
 814         if (err >= 0)
 815                 err = len; /* success! */
 816         skb = NULL;
 817 out:
 818         release_sock(sk);
 819         kfree_skb(skb);
 820         return err;
 821 }
 822
 823 static int pep_recvmsg(struct kiocb *iocb, struct sock *sk,
 824                         struct msghdr *msg, size_t len, int noblock,
 825                         int flags, int *addr_len)
 826 {
 827         struct sk_buff *skb;
 828         int err;
 829
 830         if (unlikely(1 << sk->sk_state & (TCPF_LISTEN | TCPF_CLOSE)))
 831                 return -ENOTCONN;
 832
 833         if ((flags & MSG_OOB) || sock_flag(sk, SOCK_URGINLINE)) {
 834                 /* Dequeue and acknowledge control request */
 835                 struct pep_sock *pn = pep_sk(sk);
 836
 837                 skb = skb_dequeue(&pn->ctrlreq_queue);
 838                 if (skb) {
 839                         pep_ctrlreq_error(sk, skb, PN_PIPE_NO_ERROR,
 840                                                 GFP_KERNEL);
 841                         msg->msg_flags |= MSG_OOB;
 842                         goto copy;
 843                 }
 844                 if (flags & MSG_OOB)
 845                         return -EINVAL;
 846         }
 847
 848         skb = skb_recv_datagram(sk, flags, noblock, &err);
 849         lock_sock(sk);
 850         if (skb == NULL) {
 851                 if (err == -ENOTCONN && sk->sk_state == TCP_CLOSE_WAIT)
 852                         err = -ECONNRESET;
 853                 release_sock(sk);
 854                 return err;
 855         }
 856
 857         if (sk->sk_state == TCP_ESTABLISHED)
 858                 pipe_grant_credits(sk);
 859         release_sock(sk);
 860 copy:
 861         msg->msg_flags |= MSG_EOR;
 862         if (skb->len > len)
 863                 msg->msg_flags |= MSG_TRUNC;
 864         else
 865                 len = skb->len;
 866
 867         err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, len);
 868         if (!err)
 869                 err = (flags & MSG_TRUNC) ? skb->len : len;
 870
 871         skb_free_datagram(sk, skb);
 872         return err;
 873 }
 874
 875 static void pep_sock_unhash(struct sock *sk)
 876 {
 877         struct pep_sock *pn = pep_sk(sk);
 878         struct sock *skparent = NULL;
 879
 880         lock_sock(sk);
 881         if ((1 << sk->sk_state) & ~(TCPF_CLOSE|TCPF_LISTEN)) {
 882                 skparent = pn->listener;
 883                 sk_del_node_init(sk);
 884                 release_sock(sk);
 885
 886                 sk = skparent;
 887                 pn = pep_sk(skparent);
 888                 lock_sock(sk);
 889         }
 890         /* Unhash a listening sock only when it is closed
 891          * and all of its active connected pipes are closed. */
 892         if (hlist_empty(&pn->hlist))
 893                 pn_sock_unhash(&pn->pn_sk.sk);
 894         release_sock(sk);
 895
 896         if (skparent)
 897                 sock_put(skparent);
 898 }
 899
 900 static struct proto pep_proto = {
 901         .close          = pep_sock_close,
 902         .accept         = pep_sock_accept,
 903         .ioctl          = pep_ioctl,
 904         .init           = pep_init,
 905         .sendmsg        = pep_sendmsg,
 906         .recvmsg        = pep_recvmsg,
 907         .backlog_rcv    = pep_do_rcv,
 908         .hash           = pn_sock_hash,
 909         .unhash         = pep_sock_unhash,
 910         .get_port       = pn_sock_get_port,
 911         .obj_size       = sizeof(struct pep_sock),
 912         .owner          = THIS_MODULE,
 913         .name           = "PNPIPE",
 914 };
 915
 916 static struct phonet_protocol pep_pn_proto = {
 917         .ops            = &phonet_stream_ops,
 918         .prot           = &pep_proto,
 919         .sock_type      = SOCK_SEQPACKET,
 920 };
 921
 922 static int __init pep_register(void)
 923 {
 924         return phonet_proto_register(PN_PROTO_PIPE, &pep_pn_proto);
 925 }
 926
 927 static void __exit pep_unregister(void)
 928 {
 929         phonet_proto_unregister(PN_PROTO_PIPE, &pep_pn_proto);
 930 }
 931
 932 module_init(pep_register);
 933 module_exit(pep_unregister);
 934 MODULE_AUTHOR("Remi Denis-Courmont, Nokia");
 935 MODULE_DESCRIPTION("Phonet pipe protocol");
 936 MODULE_LICENSE("GPL");
 937 MODULE_ALIAS_NET_PF_PROTO(PF_PHONET, PN_PROTO_PIPE);