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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                         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_ALIGNED_DATA:
 358                 __skb_pull(skb, 1);
 359                 /* fall through */
 360         case PNS_PIPE_DATA:
 361                 __skb_pull(skb, 3); /* Pipe data header */
 362                 if (!pn_flow_safe(pn->rx_fc)) {
 363                         err = sock_queue_rcv_skb(sk, skb);
 364                         if (!err)
 365                                 return 0;
 366                         break;
 367                 }
 368
 369                 if (pn->rx_credits == 0) {
 370                         atomic_inc(&sk->sk_drops);
 371                         err = -ENOBUFS;
 372                         break;
 373                 }
 374                 pn->rx_credits--;
 375                 queue = &sk->sk_receive_queue;
 376                 goto queue;
 377
 378         case PNS_PEP_STATUS_IND:
 379                 pipe_rcv_status(sk, skb);
 380                 break;
 381
 382         case PNS_PIPE_REDIRECTED_IND:
 383                 err = pipe_rcv_created(sk, skb);
 384                 break;
 385
 386         case PNS_PIPE_CREATED_IND:
 387                 err = pipe_rcv_created(sk, skb);
 388                 if (err)
 389                         break;
 390                 /* fall through */
 391         case PNS_PIPE_RESET_IND:
 392                 if (!pn->init_enable)
 393                         break;
 394                 /* fall through */
 395         case PNS_PIPE_ENABLED_IND:
 396                 if (!pn_flow_safe(pn->tx_fc)) {
 397                         atomic_set(&pn->tx_credits, 1);
 398                         sk->sk_write_space(sk);
 399                 }
 400                 if (sk->sk_state == TCP_ESTABLISHED)
 401                         break; /* Nothing to do */
 402                 sk->sk_state = TCP_ESTABLISHED;
 403                 pipe_grant_credits(sk);
 404                 break;
 405
 406         case PNS_PIPE_DISABLED_IND:
 407                 sk->sk_state = TCP_SYN_RECV;
 408                 pn->rx_credits = 0;
 409                 break;
 410
 411         default:
 412                 LIMIT_NETDEBUG(KERN_DEBUG"Phonet unknown PEP message: %u\n",
 413                                 hdr->message_id);
 414                 err = -EINVAL;
 415         }
 416 out:
 417         kfree_skb(skb);
 418         return err;
 419
 420 queue:
 421         skb->dev = NULL;
 422         skb_set_owner_r(skb, sk);
 423         err = skb->len;
 424         skb_queue_tail(queue, skb);
 425         if (!sock_flag(sk, SOCK_DEAD))
 426                 sk->sk_data_ready(sk, err);
 427         return 0;
 428 }
 429
 430 /* Destroy connected sock. */
 431 static void pipe_destruct(struct sock *sk)
 432 {
 433         struct pep_sock *pn = pep_sk(sk);
 434
 435         skb_queue_purge(&sk->sk_receive_queue);
 436         skb_queue_purge(&pn->ctrlreq_queue);
 437 }
 438
 439 static int pep_connreq_rcv(struct sock *sk, struct sk_buff *skb)
 440 {
 441         struct sock *newsk;
 442         struct pep_sock *newpn, *pn = pep_sk(sk);
 443         struct pnpipehdr *hdr;
 444         struct sockaddr_pn dst;
 445         u16 peer_type;
 446         u8 pipe_handle, enabled, n_sb;
 447         u8 aligned = 0;
 448
 449         if (!pskb_pull(skb, sizeof(*hdr) + 4))
 450                 return -EINVAL;
 451
 452         hdr = pnp_hdr(skb);
 453         pipe_handle = hdr->pipe_handle;
 454         switch (hdr->state_after_connect) {
 455         case PN_PIPE_DISABLE:
 456                 enabled = 0;
 457                 break;
 458         case PN_PIPE_ENABLE:
 459                 enabled = 1;
 460                 break;
 461         default:
 462                 pep_reject_conn(sk, skb, PN_PIPE_ERR_INVALID_PARAM);
 463                 return -EINVAL;
 464         }
 465         peer_type = hdr->other_pep_type << 8;
 466
 467         if (unlikely(sk->sk_state != TCP_LISTEN) || sk_acceptq_is_full(sk)) {
 468                 pep_reject_conn(sk, skb, PN_PIPE_ERR_PEP_IN_USE);
 469                 return -ENOBUFS;
 470         }
 471
 472         /* Parse sub-blocks (options) */
 473         n_sb = hdr->data[4];
 474         while (n_sb > 0) {
 475                 u8 type, buf[1], len = sizeof(buf);
 476                 const u8 *data = pep_get_sb(skb, &type, &len, buf);
 477
 478                 if (data == NULL)
 479                         return -EINVAL;
 480                 switch (type) {
 481                 case PN_PIPE_SB_CONNECT_REQ_PEP_SUB_TYPE:
 482                         if (len < 1)
 483                                 return -EINVAL;
 484                         peer_type = (peer_type & 0xff00) | data[0];
 485                         break;
 486                 case PN_PIPE_SB_ALIGNED_DATA:
 487                         aligned = data[0] != 0;
 488                         break;
 489                 }
 490                 n_sb--;
 491         }
 492
 493         skb = skb_clone(skb, GFP_ATOMIC);
 494         if (!skb)
 495                 return -ENOMEM;
 496
 497         /* Create a new to-be-accepted sock */
 498         newsk = sk_alloc(sock_net(sk), PF_PHONET, GFP_ATOMIC, sk->sk_prot);
 499         if (!newsk) {
 500                 kfree_skb(skb);
 501                 return -ENOMEM;
 502         }
 503         sock_init_data(NULL, newsk);
 504         newsk->sk_state = TCP_SYN_RECV;
 505         newsk->sk_backlog_rcv = pipe_do_rcv;
 506         newsk->sk_protocol = sk->sk_protocol;
 507         newsk->sk_destruct = pipe_destruct;
 508
 509         newpn = pep_sk(newsk);
 510         pn_skb_get_dst_sockaddr(skb, &dst);
 511         newpn->pn_sk.sobject = pn_sockaddr_get_object(&dst);
 512         newpn->pn_sk.resource = pn->pn_sk.resource;
 513         skb_queue_head_init(&newpn->ctrlreq_queue);
 514         newpn->pipe_handle = pipe_handle;
 515         atomic_set(&newpn->tx_credits, 0);
 516         newpn->peer_type = peer_type;
 517         newpn->rx_credits = 0;
 518         newpn->rx_fc = newpn->tx_fc = PN_LEGACY_FLOW_CONTROL;
 519         newpn->init_enable = enabled;
 520         newpn->aligned = aligned;
 521
 522         BUG_ON(!skb_queue_empty(&newsk->sk_receive_queue));
 523         skb_queue_head(&newsk->sk_receive_queue, skb);
 524         if (!sock_flag(sk, SOCK_DEAD))
 525                 sk->sk_data_ready(sk, 0);
 526
 527         sk_acceptq_added(sk);
 528         sk_add_node(newsk, &pn->ackq);
 529         return 0;
 530 }
 531
 532 /* Listening sock must be locked */
 533 static struct sock *pep_find_pipe(const struct hlist_head *hlist,
 534                                         const struct sockaddr_pn *dst,
 535                                         u8 pipe_handle)
 536 {
 537         struct hlist_node *node;
 538         struct sock *sknode;
 539         u16 dobj = pn_sockaddr_get_object(dst);
 540
 541         sk_for_each(sknode, node, hlist) {
 542                 struct pep_sock *pnnode = pep_sk(sknode);
 543
 544                 /* Ports match, but addresses might not: */
 545                 if (pnnode->pn_sk.sobject != dobj)
 546                         continue;
 547                 if (pnnode->pipe_handle != pipe_handle)
 548                         continue;
 549                 if (sknode->sk_state == TCP_CLOSE_WAIT)
 550                         continue;
 551
 552                 sock_hold(sknode);
 553                 return sknode;
 554         }
 555         return NULL;
 556 }
 557
 558 /*
 559  * Deliver an skb to a listening sock.
 560  * Socket lock must be held.
 561  * We then queue the skb to the right connected sock (if any).
 562  */
 563 static int pep_do_rcv(struct sock *sk, struct sk_buff *skb)
 564 {
 565         struct pep_sock *pn = pep_sk(sk);
 566         struct sock *sknode;
 567         struct pnpipehdr *hdr;
 568         struct sockaddr_pn dst;
 569         int err = NET_RX_SUCCESS;
 570         u8 pipe_handle;
 571
 572         if (!pskb_may_pull(skb, sizeof(*hdr)))
 573                 goto drop;
 574
 575         hdr = pnp_hdr(skb);
 576         pipe_handle = hdr->pipe_handle;
 577         if (pipe_handle == PN_PIPE_INVALID_HANDLE)
 578                 goto drop;
 579
 580         pn_skb_get_dst_sockaddr(skb, &dst);
 581
 582         /* Look for an existing pipe handle */
 583         sknode = pep_find_pipe(&pn->hlist, &dst, pipe_handle);
 584         if (sknode)
 585                 return sk_receive_skb(sknode, skb, 1);
 586
 587         /* Look for a pipe handle pending accept */
 588         sknode = pep_find_pipe(&pn->ackq, &dst, pipe_handle);
 589         if (sknode) {
 590                 sock_put(sknode);
 591                 if (net_ratelimit())
 592                         printk(KERN_WARNING"Phonet unconnected PEP ignored");
 593                 err = NET_RX_DROP;
 594                 goto drop;
 595         }
 596
 597         switch (hdr->message_id) {
 598         case PNS_PEP_CONNECT_REQ:
 599                 err = pep_connreq_rcv(sk, skb);
 600                 break;
 601
 602         case PNS_PEP_DISCONNECT_REQ:
 603                 pep_reply(sk, skb, PN_PIPE_NO_ERROR, NULL, 0, GFP_ATOMIC);
 604                 break;
 605
 606         case PNS_PEP_CTRL_REQ:
 607                 pep_ctrlreq_error(sk, skb, PN_PIPE_INVALID_HANDLE, GFP_ATOMIC);
 608                 break;
 609
 610         case PNS_PEP_RESET_REQ:
 611         case PNS_PEP_ENABLE_REQ:
 612         case PNS_PEP_DISABLE_REQ:
 613                 /* invalid handle is not even allowed here! */
 614         default:
 615                 err = NET_RX_DROP;
 616         }
 617 drop:
 618         kfree_skb(skb);
 619         return err;
 620 }
 621
 622 /* associated socket ceases to exist */
 623 static void pep_sock_close(struct sock *sk, long timeout)
 624 {
 625         struct pep_sock *pn = pep_sk(sk);
 626         int ifindex = 0;
 627
 628         sk_common_release(sk);
 629
 630         lock_sock(sk);
 631         if (sk->sk_state == TCP_LISTEN) {
 632                 /* Destroy the listen queue */
 633                 struct sock *sknode;
 634                 struct hlist_node *p, *n;
 635
 636                 sk_for_each_safe(sknode, p, n, &pn->ackq)
 637                         sk_del_node_init(sknode);
 638                 sk->sk_state = TCP_CLOSE;
 639         }
 640         ifindex = pn->ifindex;
 641         pn->ifindex = 0;
 642         release_sock(sk);
 643
 644         if (ifindex)
 645                 gprs_detach(sk);
 646 }
 647
 648 static int pep_wait_connreq(struct sock *sk, int noblock)
 649 {
 650         struct task_struct *tsk = current;
 651         struct pep_sock *pn = pep_sk(sk);
 652         long timeo = sock_rcvtimeo(sk, noblock);
 653
 654         for (;;) {
 655                 DEFINE_WAIT(wait);
 656
 657                 if (sk->sk_state != TCP_LISTEN)
 658                         return -EINVAL;
 659                 if (!hlist_empty(&pn->ackq))
 660                         break;
 661                 if (!timeo)
 662                         return -EWOULDBLOCK;
 663                 if (signal_pending(tsk))
 664                         return sock_intr_errno(timeo);
 665
 666                 prepare_to_wait_exclusive(&sk->sk_socket->wait, &wait,
 667                                                 TASK_INTERRUPTIBLE);
 668                 release_sock(sk);
 669                 timeo = schedule_timeout(timeo);
 670                 lock_sock(sk);
 671                 finish_wait(&sk->sk_socket->wait, &wait);
 672         }
 673
 674         return 0;
 675 }
 676
 677 static struct sock *pep_sock_accept(struct sock *sk, int flags, int *errp)
 678 {
 679         struct pep_sock *pn = pep_sk(sk);
 680         struct sock *newsk = NULL;
 681         struct sk_buff *oskb;
 682         int err;
 683
 684         lock_sock(sk);
 685         err = pep_wait_connreq(sk, flags & O_NONBLOCK);
 686         if (err)
 687                 goto out;
 688
 689         newsk = __sk_head(&pn->ackq);
 690
 691         oskb = skb_dequeue(&newsk->sk_receive_queue);
 692         err = pep_accept_conn(newsk, oskb);
 693         if (err) {
 694                 skb_queue_head(&newsk->sk_receive_queue, oskb);
 695                 newsk = NULL;
 696                 goto out;
 697         }
 698
 699         sock_hold(sk);
 700         pep_sk(newsk)->listener = sk;
 701
 702         sock_hold(newsk);
 703         sk_del_node_init(newsk);
 704         sk_acceptq_removed(sk);
 705         sk_add_node(newsk, &pn->hlist);
 706         __sock_put(newsk);
 707
 708 out:
 709         release_sock(sk);
 710         *errp = err;
 711         return newsk;
 712 }
 713
 714 static int pep_ioctl(struct sock *sk, int cmd, unsigned long arg)
 715 {
 716         struct pep_sock *pn = pep_sk(sk);
 717         int answ;
 718
 719         switch (cmd) {
 720         case SIOCINQ:
 721                 if (sk->sk_state == TCP_LISTEN)
 722                         return -EINVAL;
 723
 724                 lock_sock(sk);
 725                 if (sock_flag(sk, SOCK_URGINLINE) &&
 726                     !skb_queue_empty(&pn->ctrlreq_queue))
 727                         answ = skb_peek(&pn->ctrlreq_queue)->len;
 728                 else if (!skb_queue_empty(&sk->sk_receive_queue))
 729                         answ = skb_peek(&sk->sk_receive_queue)->len;
 730                 else
 731                         answ = 0;
 732                 release_sock(sk);
 733                 return put_user(answ, (int __user *)arg);
 734         }
 735
 736         return -ENOIOCTLCMD;
 737 }
 738
 739 static int pep_init(struct sock *sk)
 740 {
 741         struct pep_sock *pn = pep_sk(sk);
 742
 743         INIT_HLIST_HEAD(&pn->ackq);
 744         INIT_HLIST_HEAD(&pn->hlist);
 745         skb_queue_head_init(&pn->ctrlreq_queue);
 746         pn->pipe_handle = PN_PIPE_INVALID_HANDLE;
 747         return 0;
 748 }
 749
 750 static int pep_setsockopt(struct sock *sk, int level, int optname,
 751                                 char __user *optval, unsigned int optlen)
 752 {
 753         struct pep_sock *pn = pep_sk(sk);
 754         int val = 0, err = 0;
 755
 756         if (level != SOL_PNPIPE)
 757                 return -ENOPROTOOPT;
 758         if (optlen >= sizeof(int)) {
 759                 if (get_user(val, (int __user *) optval))
 760                         return -EFAULT;
 761         }
 762
 763         lock_sock(sk);
 764         switch (optname) {
 765         case PNPIPE_ENCAP:
 766                 if (val && val != PNPIPE_ENCAP_IP) {
 767                         err = -EINVAL;
 768                         break;
 769                 }
 770                 if (!pn->ifindex == !val)
 771                         break; /* Nothing to do! */
 772                 if (!capable(CAP_NET_ADMIN)) {
 773                         err = -EPERM;
 774                         break;
 775                 }
 776                 if (val) {
 777                         release_sock(sk);
 778                         err = gprs_attach(sk);
 779                         if (err > 0) {
 780                                 pn->ifindex = err;
 781                                 err = 0;
 782                         }
 783                 } else {
 784                         pn->ifindex = 0;
 785                         release_sock(sk);
 786                         gprs_detach(sk);
 787                         err = 0;
 788                 }
 789                 goto out_norel;
 790         default:
 791                 err = -ENOPROTOOPT;
 792         }
 793         release_sock(sk);
 794
 795 out_norel:
 796         return err;
 797 }
 798
 799 static int pep_getsockopt(struct sock *sk, int level, int optname,
 800                                 char __user *optval, int __user *optlen)
 801 {
 802         struct pep_sock *pn = pep_sk(sk);
 803         int len, val;
 804
 805         if (level != SOL_PNPIPE)
 806                 return -ENOPROTOOPT;
 807         if (get_user(len, optlen))
 808                 return -EFAULT;
 809
 810         switch (optname) {
 811         case PNPIPE_ENCAP:
 812                 val = pn->ifindex ? PNPIPE_ENCAP_IP : PNPIPE_ENCAP_NONE;
 813                 break;
 814         case PNPIPE_IFINDEX:
 815                 val = pn->ifindex;
 816                 break;
 817         default:
 818                 return -ENOPROTOOPT;
 819         }
 820
 821         len = min_t(unsigned int, sizeof(int), len);
 822         if (put_user(len, optlen))
 823                 return -EFAULT;
 824         if (put_user(val, (int __user *) optval))
 825                 return -EFAULT;
 826         return 0;
 827 }
 828
 829 static int pipe_skb_send(struct sock *sk, struct sk_buff *skb)
 830 {
 831         struct pep_sock *pn = pep_sk(sk);
 832         struct pnpipehdr *ph;
 833
 834         if (pn_flow_safe(pn->tx_fc) &&
 835             !atomic_add_unless(&pn->tx_credits, -1, 0)) {
 836                 kfree_skb(skb);
 837                 return -ENOBUFS;
 838         }
 839
 840         skb_push(skb, 3 + pn->aligned);
 841         skb_reset_transport_header(skb);
 842         ph = pnp_hdr(skb);
 843         ph->utid = 0;
 844         if (pn->aligned) {
 845                 ph->message_id = PNS_PIPE_ALIGNED_DATA;
 846                 ph->data[0] = 0; /* padding */
 847         } else
 848                 ph->message_id = PNS_PIPE_DATA;
 849         ph->pipe_handle = pn->pipe_handle;
 850
 851         return pn_skb_send(sk, skb, &pipe_srv);
 852 }
 853
 854 static int pep_sendmsg(struct kiocb *iocb, struct sock *sk,
 855                         struct msghdr *msg, size_t len)
 856 {
 857         struct pep_sock *pn = pep_sk(sk);
 858         struct sk_buff *skb;
 859         long timeo;
 860         int flags = msg->msg_flags;
 861         int err, done;
 862
 863         if ((msg->msg_flags & ~(MSG_DONTWAIT|MSG_EOR|MSG_NOSIGNAL|
 864                                 MSG_CMSG_COMPAT)) ||
 865                         !(msg->msg_flags & MSG_EOR))
 866                 return -EOPNOTSUPP;
 867
 868         skb = sock_alloc_send_skb(sk, MAX_PNPIPE_HEADER + len,
 869                                         flags & MSG_DONTWAIT, &err);
 870         if (!skb)
 871                 return -ENOBUFS;
 872
 873         skb_reserve(skb, MAX_PHONET_HEADER + 3);
 874         err = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len);
 875         if (err < 0)
 876                 goto outfree;
 877
 878         lock_sock(sk);
 879         timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT);
 880         if ((1 << sk->sk_state) & (TCPF_LISTEN|TCPF_CLOSE)) {
 881                 err = -ENOTCONN;
 882                 goto out;
 883         }
 884         if (sk->sk_state != TCP_ESTABLISHED) {
 885                 /* Wait until the pipe gets to enabled state */
 886 disabled:
 887                 err = sk_stream_wait_connect(sk, &timeo);
 888                 if (err)
 889                         goto out;
 890
 891                 if (sk->sk_state == TCP_CLOSE_WAIT) {
 892                         err = -ECONNRESET;
 893                         goto out;
 894                 }
 895         }
 896         BUG_ON(sk->sk_state != TCP_ESTABLISHED);
 897
 898         /* Wait until flow control allows TX */
 899         done = atomic_read(&pn->tx_credits);
 900         while (!done) {
 901                 DEFINE_WAIT(wait);
 902
 903                 if (!timeo) {
 904                         err = -EAGAIN;
 905                         goto out;
 906                 }
 907                 if (signal_pending(current)) {
 908                         err = sock_intr_errno(timeo);
 909                         goto out;
 910                 }
 911
 912                 prepare_to_wait(&sk->sk_socket->wait, &wait,
 913                                 TASK_INTERRUPTIBLE);
 914                 done = sk_wait_event(sk, &timeo, atomic_read(&pn->tx_credits));
 915                 finish_wait(&sk->sk_socket->wait, &wait);
 916
 917                 if (sk->sk_state != TCP_ESTABLISHED)
 918                         goto disabled;
 919         }
 920
 921         err = pipe_skb_send(sk, skb);
 922         if (err >= 0)
 923                 err = len; /* success! */
 924         skb = NULL;
 925 out:
 926         release_sock(sk);
 927 outfree:
 928         kfree_skb(skb);
 929         return err;
 930 }
 931
 932 int pep_writeable(struct sock *sk)
 933 {
 934         struct pep_sock *pn = pep_sk(sk);
 935
 936         return atomic_read(&pn->tx_credits);
 937 }
 938
 939 int pep_write(struct sock *sk, struct sk_buff *skb)
 940 {
 941         struct sk_buff *rskb, *fs;
 942         int flen = 0;
 943
 944         if (pep_sk(sk)->aligned)
 945                 return pipe_skb_send(sk, skb);
 946
 947         rskb = alloc_skb(MAX_PNPIPE_HEADER, GFP_ATOMIC);
 948         if (!rskb) {
 949                 kfree_skb(skb);
 950                 return -ENOMEM;
 951         }
 952         skb_shinfo(rskb)->frag_list = skb;
 953         rskb->len += skb->len;
 954         rskb->data_len += rskb->len;
 955         rskb->truesize += rskb->len;
 956
 957         /* Avoid nested fragments */
 958         skb_walk_frags(skb, fs)
 959                 flen += fs->len;
 960         skb->next = skb_shinfo(skb)->frag_list;
 961         skb_frag_list_init(skb);
 962         skb->len -= flen;
 963         skb->data_len -= flen;
 964         skb->truesize -= flen;
 965
 966         skb_reserve(rskb, MAX_PHONET_HEADER + 3);
 967         return pipe_skb_send(sk, rskb);
 968 }
 969
 970 struct sk_buff *pep_read(struct sock *sk)
 971 {
 972         struct sk_buff *skb = skb_dequeue(&sk->sk_receive_queue);
 973
 974         if (sk->sk_state == TCP_ESTABLISHED)
 975                 pipe_grant_credits(sk);
 976         return skb;
 977 }
 978
 979 static int pep_recvmsg(struct kiocb *iocb, struct sock *sk,
 980                         struct msghdr *msg, size_t len, int noblock,
 981                         int flags, int *addr_len)
 982 {
 983         struct sk_buff *skb;
 984         int err;
 985
 986         if (flags & ~(MSG_OOB|MSG_PEEK|MSG_TRUNC|MSG_DONTWAIT|MSG_WAITALL|
 987                         MSG_NOSIGNAL|MSG_CMSG_COMPAT))
 988                 return -EOPNOTSUPP;
 989
 990         if (unlikely(1 << sk->sk_state & (TCPF_LISTEN | TCPF_CLOSE)))
 991                 return -ENOTCONN;
 992
 993         if ((flags & MSG_OOB) || sock_flag(sk, SOCK_URGINLINE)) {
 994                 /* Dequeue and acknowledge control request */
 995                 struct pep_sock *pn = pep_sk(sk);
 996
 997                 if (flags & MSG_PEEK)
 998                         return -EOPNOTSUPP;
 999                 skb = skb_dequeue(&pn->ctrlreq_queue);
1000                 if (skb) {
1001                         pep_ctrlreq_error(sk, skb, PN_PIPE_NO_ERROR,
1002                                                 GFP_KERNEL);
1003                         msg->msg_flags |= MSG_OOB;
1004                         goto copy;
1005                 }
1006                 if (flags & MSG_OOB)
1007                         return -EINVAL;
1008         }
1009
1010         skb = skb_recv_datagram(sk, flags, noblock, &err);
1011         lock_sock(sk);
1012         if (skb == NULL) {
1013                 if (err == -ENOTCONN && sk->sk_state == TCP_CLOSE_WAIT)
1014                         err = -ECONNRESET;
1015                 release_sock(sk);
1016                 return err;
1017         }
1018
1019         if (sk->sk_state == TCP_ESTABLISHED)
1020                 pipe_grant_credits(sk);
1021         release_sock(sk);
1022 copy:
1023         msg->msg_flags |= MSG_EOR;
1024         if (skb->len > len)
1025                 msg->msg_flags |= MSG_TRUNC;
1026         else
1027                 len = skb->len;
1028
1029         err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, len);
1030         if (!err)
1031                 err = (flags & MSG_TRUNC) ? skb->len : len;
1032
1033         skb_free_datagram(sk, skb);
1034         return err;
1035 }
1036
1037 static void pep_sock_unhash(struct sock *sk)
1038 {
1039         struct pep_sock *pn = pep_sk(sk);
1040         struct sock *skparent = NULL;
1041
1042         lock_sock(sk);
1043         if ((1 << sk->sk_state) & ~(TCPF_CLOSE|TCPF_LISTEN)) {
1044                 skparent = pn->listener;
1045                 sk_del_node_init(sk);
1046                 release_sock(sk);
1047
1048                 sk = skparent;
1049                 pn = pep_sk(skparent);
1050                 lock_sock(sk);
1051         }
1052         /* Unhash a listening sock only when it is closed
1053          * and all of its active connected pipes are closed. */
1054         if (hlist_empty(&pn->hlist))
1055                 pn_sock_unhash(&pn->pn_sk.sk);
1056         release_sock(sk);
1057
1058         if (skparent)
1059                 sock_put(skparent);
1060 }
1061
1062 static struct proto pep_proto = {
1063         .close          = pep_sock_close,
1064         .accept         = pep_sock_accept,
1065         .ioctl          = pep_ioctl,
1066         .init           = pep_init,
1067         .setsockopt     = pep_setsockopt,
1068         .getsockopt     = pep_getsockopt,
1069         .sendmsg        = pep_sendmsg,
1070         .recvmsg        = pep_recvmsg,
1071         .backlog_rcv    = pep_do_rcv,
1072         .hash           = pn_sock_hash,
1073         .unhash         = pep_sock_unhash,
1074         .get_port       = pn_sock_get_port,
1075         .obj_size       = sizeof(struct pep_sock),
1076         .owner          = THIS_MODULE,
1077         .name           = "PNPIPE",
1078 };
1079
1080 static struct phonet_protocol pep_pn_proto = {
1081         .ops            = &phonet_stream_ops,
1082         .prot           = &pep_proto,
1083         .sock_type      = SOCK_SEQPACKET,
1084 };
1085
1086 static int __init pep_register(void)
1087 {
1088         return phonet_proto_register(PN_PROTO_PIPE, &pep_pn_proto);
1089 }
1090
1091 static void __exit pep_unregister(void)
1092 {
1093         phonet_proto_unregister(PN_PROTO_PIPE, &pep_pn_proto);
1094 }
1095
1096 module_init(pep_register);
1097 module_exit(pep_unregister);
1098 MODULE_AUTHOR("Remi Denis-Courmont, Nokia");
1099 MODULE_DESCRIPTION("Phonet pipe protocol");
1100 MODULE_LICENSE("GPL");
1101 MODULE_ALIAS_NET_PF_PROTO(PF_PHONET, PN_PROTO_PIPE);