net/phonet/pep.c

   1 /*
   2  * File: pep.c
   3  *
   4  * Phonet pipe protocol end point socket
   5  *
   6  * Copyright (C) 2008 Nokia Corporation.
   7  *
   8  * Author: Rémi Denis-Courmont <remi.denis-courmont@nokia.com>
   9  *
  10  * This program is free software; you can redistribute it and/or
  11  * modify it under the terms of the GNU General Public License
  12  * version 2 as published by the Free Software Foundation.
  13  *
  14  * This program is distributed in the hope that it will be useful, but
  15  * WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  17  * General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program; if not, write to the Free Software
  21  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
  22  * 02110-1301 USA
  23  */
  24
  25 #include <linux/kernel.h>
  26 #include <linux/socket.h>
  27 #include <net/sock.h>
  28 #include <net/tcp_states.h>
  29 #include <asm/ioctls.h>
  30
  31 #include <linux/phonet.h>
  32 #include <net/phonet/phonet.h>
  33 #include <net/phonet/pep.h>
  34 #include <net/phonet/gprs.h>
  35
  36 /* sk_state values:
  37  * TCP_CLOSE            sock not in use yet
  38  * TCP_CLOSE_WAIT       disconnected pipe
  39  * TCP_LISTEN           listening pipe endpoint
  40  * TCP_SYN_RECV         connected pipe in disabled state
  41  * TCP_ESTABLISHED      connected pipe in enabled state
  42  *
  43  * pep_sock locking:
  44  *  - sk_state, ackq, hlist: sock lock needed
  45  *  - listener: read only
  46  *  - pipe_handle: read only
  47  */
  48
  49 #define CREDITS_MAX     10
  50 #define CREDITS_THR     7
  51
  52 static const struct sockaddr_pn pipe_srv = {
  53         .spn_family = AF_PHONET,
  54         .spn_resource = 0xD9, /* pipe service */
  55 };
  56
  57 #define pep_sb_size(s) (((s) + 5) & ~3) /* 2-bytes head, 32-bits aligned */
  58
  59 /* Get the next TLV sub-block. */
  60 static unsigned char *pep_get_sb(struct sk_buff *skb, u8 *ptype, u8 *plen,
  61                                         void *buf)
  62 {
  63         void *data = NULL;
  64         struct {
  65                 u8 sb_type;
  66                 u8 sb_len;
  67         } *ph, h;
  68         int buflen = *plen;
  69
  70         ph = skb_header_pointer(skb, 0, 2, &h);
  71         if (ph == NULL || ph->sb_len < 2 || !pskb_may_pull(skb, ph->sb_len))
  72                 return NULL;
  73         ph->sb_len -= 2;
  74         *ptype = ph->sb_type;
  75         *plen = ph->sb_len;
  76
  77         if (buflen > ph->sb_len)
  78                 buflen = ph->sb_len;
  79         data = skb_header_pointer(skb, 2, buflen, buf);
  80         __skb_pull(skb, 2 + ph->sb_len);
  81         return data;
  82 }
  83
  84 static int pep_reply(struct sock *sk, struct sk_buff *oskb,
  85                         u8 code, const void *data, int len, gfp_t priority)
  86 {
  87         const struct pnpipehdr *oph = pnp_hdr(oskb);
  88         struct pnpipehdr *ph;
  89         struct sk_buff *skb;
  90
  91         skb = alloc_skb(MAX_PNPIPE_HEADER + len, priority);
  92         if (!skb)
  93                 return -ENOMEM;
  94         skb_set_owner_w(skb, sk);
  95
  96         skb_reserve(skb, MAX_PNPIPE_HEADER);
  97         __skb_put(skb, len);
  98         skb_copy_to_linear_data(skb, data, len);
  99         __skb_push(skb, sizeof(*ph));
 100         skb_reset_transport_header(skb);
 101         ph = pnp_hdr(skb);
 102         ph->utid = oph->utid;
 103         ph->message_id = oph->message_id + 1; /* REQ -> RESP */
 104         ph->pipe_handle = oph->pipe_handle;
 105         ph->error_code = code;
 106
 107         return pn_skb_send(sk, skb, &pipe_srv);
 108 }
 109
 110 #define PAD 0x00
 111 static int pep_accept_conn(struct sock *sk, struct sk_buff *skb)
 112 {
 113         static const u8 data[20] = {
 114                 PAD, PAD, PAD, 2 /* sub-blocks */,
 115                 PN_PIPE_SB_REQUIRED_FC_TX, pep_sb_size(5), 3, PAD,
 116                         PN_MULTI_CREDIT_FLOW_CONTROL,
 117                         PN_ONE_CREDIT_FLOW_CONTROL,
 118                         PN_LEGACY_FLOW_CONTROL,
 119                         PAD,
 120                 PN_PIPE_SB_PREFERRED_FC_RX, pep_sb_size(5), 3, PAD,
 121                         PN_MULTI_CREDIT_FLOW_CONTROL,
 122                         PN_ONE_CREDIT_FLOW_CONTROL,
 123                         PN_LEGACY_FLOW_CONTROL,
 124                         PAD,
 125         };
 126
 127         might_sleep();
 128         return pep_reply(sk, skb, PN_PIPE_NO_ERROR, data, sizeof(data),
 129                                 GFP_KERNEL);
 130 }
 131
 132 static int pep_reject_conn(struct sock *sk, struct sk_buff *skb, u8 code)
 133 {
 134         static const u8 data[4] = { PAD, PAD, PAD, 0 /* sub-blocks */ };
 135         WARN_ON(code == PN_PIPE_NO_ERROR);
 136         return pep_reply(sk, skb, code, data, sizeof(data), GFP_ATOMIC);
 137 }
 138
 139 /* Control requests are not sent by the pipe service and have a specific
 140  * message format. */
 141 static int pep_ctrlreq_error(struct sock *sk, struct sk_buff *oskb, u8 code,
 142                                 gfp_t priority)
 143 {
 144         const struct pnpipehdr *oph = pnp_hdr(oskb);
 145         struct sk_buff *skb;
 146         struct pnpipehdr *ph;
 147         struct sockaddr_pn dst;
 148
 149         skb = alloc_skb(MAX_PNPIPE_HEADER + 4, priority);
 150         if (!skb)
 151                 return -ENOMEM;
 152         skb_set_owner_w(skb, sk);
 153
 154         skb_reserve(skb, MAX_PHONET_HEADER);
 155         ph = (struct pnpipehdr *)skb_put(skb, sizeof(*ph) + 4);
 156
 157         ph->utid = oph->utid;
 158         ph->message_id = PNS_PEP_CTRL_RESP;
 159         ph->pipe_handle = oph->pipe_handle;
 160         ph->data[0] = oph->data[1]; /* CTRL id */
 161         ph->data[1] = oph->data[0]; /* PEP type */
 162         ph->data[2] = code; /* error code, at an usual offset */
 163         ph->data[3] = PAD;
 164         ph->data[4] = PAD;
 165
 166         pn_skb_get_src_sockaddr(oskb, &dst);
 167         return pn_skb_send(sk, skb, &dst);
 168 }
 169
 170 static int pipe_snd_status(struct sock *sk, u8 type, u8 status, gfp_t priority)
 171 {
 172         struct pep_sock *pn = pep_sk(sk);
 173         struct pnpipehdr *ph;
 174         struct sk_buff *skb;
 175
 176         skb = alloc_skb(MAX_PNPIPE_HEADER + 4, priority);
 177         if (!skb)
 178                 return -ENOMEM;
 179         skb_set_owner_w(skb, sk);
 180
 181         skb_reserve(skb, MAX_PNPIPE_HEADER + 4);
 182         __skb_push(skb, sizeof(*ph) + 4);
 183         skb_reset_transport_header(skb);
 184         ph = pnp_hdr(skb);
 185         ph->utid = 0;
 186         ph->message_id = PNS_PEP_STATUS_IND;
 187         ph->pipe_handle = pn->pipe_handle;
 188         ph->pep_type = PN_PEP_TYPE_COMMON;
 189         ph->data[1] = type;
 190         ph->data[2] = PAD;
 191         ph->data[3] = PAD;
 192         ph->data[4] = status;
 193
 194         return pn_skb_send(sk, skb, &pipe_srv);
 195 }
 196
 197 /* Send our RX flow control information to the sender.
 198  * Socket must be locked. */
 199 static void pipe_grant_credits(struct sock *sk)
 200 {
 201         struct pep_sock *pn = pep_sk(sk);
 202
 203         BUG_ON(sk->sk_state != TCP_ESTABLISHED);
 204
 205         switch (pn->rx_fc) {
 206         case PN_LEGACY_FLOW_CONTROL: /* TODO */
 207                 break;
 208         case PN_ONE_CREDIT_FLOW_CONTROL:
 209                 pipe_snd_status(sk, PN_PEP_IND_FLOW_CONTROL,
 210                                 PEP_IND_READY, GFP_ATOMIC);
 211                 pn->rx_credits = 1;
 212                 break;
 213         case PN_MULTI_CREDIT_FLOW_CONTROL:
 214                 if ((pn->rx_credits + CREDITS_THR) > CREDITS_MAX)
 215                         break;
 216                 if (pipe_snd_status(sk, PN_PEP_IND_ID_MCFC_GRANT_CREDITS,
 217                                         CREDITS_MAX - pn->rx_credits,
 218                                         GFP_ATOMIC) == 0)
 219                         pn->rx_credits = CREDITS_MAX;
 220                 break;
 221         }
 222 }
 223
 224 static int pipe_rcv_status(struct sock *sk, struct sk_buff *skb)
 225 {
 226         struct pep_sock *pn = pep_sk(sk);
 227         struct pnpipehdr *hdr = pnp_hdr(skb);
 228         int wake = 0;
 229
 230         if (!pskb_may_pull(skb, sizeof(*hdr) + 4))
 231                 return -EINVAL;
 232
 233         if (hdr->data[0] != PN_PEP_TYPE_COMMON) {
 234                 LIMIT_NETDEBUG(KERN_DEBUG"Phonet unknown PEP type: %u\n",
 235                                 (unsigned)hdr->data[0]);
 236                 return -EOPNOTSUPP;
 237         }
 238
 239         switch (hdr->data[1]) {
 240         case PN_PEP_IND_FLOW_CONTROL:
 241                 switch (pn->tx_fc) {
 242                 case PN_LEGACY_FLOW_CONTROL:
 243                         switch (hdr->data[4]) {
 244                         case PEP_IND_BUSY:
 245                                 atomic_set(&pn->tx_credits, 0);
 246                                 break;
 247                         case PEP_IND_READY:
 248                                 atomic_set(&pn->tx_credits, wake = 1);
 249                                 break;
 250                         }
 251                         break;
 252                 case PN_ONE_CREDIT_FLOW_CONTROL:
 253                         if (hdr->data[4] == PEP_IND_READY)
 254                                 atomic_set(&pn->tx_credits, wake = 1);
 255                         break;
 256                 }
 257                 break;
 258
 259         case PN_PEP_IND_ID_MCFC_GRANT_CREDITS:
 260                 if (pn->tx_fc != PN_MULTI_CREDIT_FLOW_CONTROL)
 261                         break;
 262                 atomic_add(wake = hdr->data[4], &pn->tx_credits);
 263                 break;
 264
 265         default:
 266                 LIMIT_NETDEBUG(KERN_DEBUG"Phonet unknown PEP indication: %u\n",
 267                                 (unsigned)hdr->data[1]);
 268                 return -EOPNOTSUPP;
 269         }
 270         if (wake)
 271                 sk->sk_write_space(sk);
 272         return 0;
 273 }
 274
 275 static int pipe_rcv_created(struct sock *sk, struct sk_buff *skb)
 276 {
 277         struct pep_sock *pn = pep_sk(sk);
 278         struct pnpipehdr *hdr = pnp_hdr(skb);
 279         u8 n_sb = hdr->data[0];
 280
 281         pn->rx_fc = pn->tx_fc = PN_LEGACY_FLOW_CONTROL;
 282         __skb_pull(skb, sizeof(*hdr));
 283         while (n_sb > 0) {
 284                 u8 type, buf[2], len = sizeof(buf);
 285                 u8 *data = pep_get_sb(skb, &type, &len, buf);
 286
 287                 if (data == NULL)
 288                         return -EINVAL;
 289                 switch (type) {
 290                 case PN_PIPE_SB_NEGOTIATED_FC:
 291                         if (len < 2 || (data[0] | data[1]) > 3)
 292                                 break;
 293                         pn->tx_fc = data[0] & 3;
 294                         pn->rx_fc = data[1] & 3;
 295                         break;
 296                 }
 297                 n_sb--;
 298         }
 299         return 0;
 300 }
 301
 302 /* Queue an skb to a connected sock.
 303  * Socket lock must be held. */
 304 static int pipe_do_rcv(struct sock *sk, struct sk_buff *skb)
 305 {
 306         struct pep_sock *pn = pep_sk(sk);
 307         struct pnpipehdr *hdr = pnp_hdr(skb);
 308         struct sk_buff_head *queue;
 309         int err = 0;
 310
 311         BUG_ON(sk->sk_state == TCP_CLOSE_WAIT);
 312
 313         switch (hdr->message_id) {
 314         case PNS_PEP_CONNECT_REQ:
 315                 pep_reject_conn(sk, skb, PN_PIPE_ERR_PEP_IN_USE);
 316                 break;
 317
 318         case PNS_PEP_DISCONNECT_REQ:
 319                 pep_reply(sk, skb, PN_PIPE_NO_ERROR, NULL, 0, GFP_ATOMIC);
 320                 sk->sk_state = TCP_CLOSE_WAIT;
 321                 if (!sock_flag(sk, SOCK_DEAD))
 322                         sk->sk_state_change(sk);
 323                 break;
 324
 325         case PNS_PEP_ENABLE_REQ:
 326                 /* Wait for PNS_PIPE_(ENABLED|REDIRECTED)_IND */
 327                 pep_reply(sk, skb, PN_PIPE_NO_ERROR, NULL, 0, GFP_ATOMIC);
 328                 break;
 329
 330         case PNS_PEP_RESET_REQ:
 331                 switch (hdr->state_after_reset) {
 332                 case PN_PIPE_DISABLE:
 333                         pn->init_enable = 0;
 334                         break;
 335                 case PN_PIPE_ENABLE:
 336                         pn->init_enable = 1;
 337                         break;
 338                 default: /* not allowed to send an error here!? */
 339                         err = -EINVAL;
 340                         goto out;
 341                 }
 342                 /* fall through */
 343         case PNS_PEP_DISABLE_REQ:
 344                 atomic_set(&pn->tx_credits, 0);
 345                 pep_reply(sk, skb, PN_PIPE_NO_ERROR, NULL, 0, GFP_ATOMIC);
 346                 break;
 347
 348         case PNS_PEP_CTRL_REQ:
 349                 if (skb_queue_len(&pn->ctrlreq_queue) >= PNPIPE_CTRLREQ_MAX) {
 350                         atomic_inc(&sk->sk_drops);
 351                         break;
 352                 }
 353                 __skb_pull(skb, 4);
 354                 queue = &pn->ctrlreq_queue;
 355                 goto queue;
 356
 357         case PNS_PIPE_DATA:
 358                 __skb_pull(skb, 3); /* Pipe data header */
 359                 if (!pn_flow_safe(pn->rx_fc)) {
 360                         err = sock_queue_rcv_skb(sk, skb);
 361                         if (!err)
 362                                 return 0;
 363                         if (err == -ENOMEM)
 364                                 atomic_inc(&sk->sk_drops);
 365                         break;
 366                 }
 367
 368                 if (pn->rx_credits == 0) {
 369                         atomic_inc(&sk->sk_drops);
 370                         err = -ENOBUFS;
 371                         break;
 372                 }
 373                 pn->rx_credits--;
 374                 queue = &sk->sk_receive_queue;
 375                 goto queue;
 376
 377         case PNS_PEP_STATUS_IND:
 378                 pipe_rcv_status(sk, skb);
 379                 break;
 380
 381         case PNS_PIPE_REDIRECTED_IND:
 382                 err = pipe_rcv_created(sk, skb);
 383                 break;
 384
 385         case PNS_PIPE_CREATED_IND:
 386                 err = pipe_rcv_created(sk, skb);
 387                 if (err)
 388                         break;
 389                 /* fall through */
 390         case PNS_PIPE_RESET_IND:
 391                 if (!pn->init_enable)
 392                         break;
 393                 /* fall through */
 394         case PNS_PIPE_ENABLED_IND:
 395                 if (!pn_flow_safe(pn->tx_fc)) {
 396                         atomic_set(&pn->tx_credits, 1);
 397                         sk->sk_write_space(sk);
 398                 }
 399                 if (sk->sk_state == TCP_ESTABLISHED)
 400                         break; /* Nothing to do */
 401                 sk->sk_state = TCP_ESTABLISHED;
 402                 pipe_grant_credits(sk);
 403                 break;
 404
 405         case PNS_PIPE_DISABLED_IND:
 406                 sk->sk_state = TCP_SYN_RECV;
 407                 pn->rx_credits = 0;
 408                 break;
 409
 410         default:
 411                 LIMIT_NETDEBUG(KERN_DEBUG"Phonet unknown PEP message: %u\n",
 412                                 hdr->message_id);
 413                 err = -EINVAL;
 414         }
 415 out:
 416         kfree_skb(skb);
 417         return err;
 418
 419 queue:
 420         skb->dev = NULL;
 421         skb_set_owner_r(skb, sk);
 422         err = skb->len;
 423         skb_queue_tail(queue, skb);
 424         if (!sock_flag(sk, SOCK_DEAD))
 425                 sk->sk_data_ready(sk, err);
 426         return 0;
 427 }
 428
 429 /* Destroy connected sock. */
 430 static void pipe_destruct(struct sock *sk)
 431 {
 432         struct pep_sock *pn = pep_sk(sk);
 433
 434         skb_queue_purge(&sk->sk_receive_queue);
 435         skb_queue_purge(&pn->ctrlreq_queue);
 436 }
 437
 438 static int pep_connreq_rcv(struct sock *sk, struct sk_buff *skb)
 439 {
 440         struct sock *newsk;
 441         struct pep_sock *newpn, *pn = pep_sk(sk);
 442         struct pnpipehdr *hdr;
 443         struct sockaddr_pn dst;
 444         u16 peer_type;
 445         u8 pipe_handle, enabled, n_sb;
 446
 447         if (!pskb_pull(skb, sizeof(*hdr) + 4))
 448                 return -EINVAL;
 449
 450         hdr = pnp_hdr(skb);
 451         pipe_handle = hdr->pipe_handle;
 452         switch (hdr->state_after_connect) {
 453         case PN_PIPE_DISABLE:
 454                 enabled = 0;
 455                 break;
 456         case PN_PIPE_ENABLE:
 457                 enabled = 1;
 458                 break;
 459         default:
 460                 pep_reject_conn(sk, skb, PN_PIPE_ERR_INVALID_PARAM);
 461                 return -EINVAL;
 462         }
 463         peer_type = hdr->other_pep_type << 8;
 464
 465         if (unlikely(sk->sk_state != TCP_LISTEN) || sk_acceptq_is_full(sk)) {
 466                 pep_reject_conn(sk, skb, PN_PIPE_ERR_PEP_IN_USE);
 467                 return -ENOBUFS;
 468         }
 469
 470         /* Parse sub-blocks (options) */
 471         n_sb = hdr->data[4];
 472         while (n_sb > 0) {
 473                 u8 type, buf[1], len = sizeof(buf);
 474                 const u8 *data = pep_get_sb(skb, &type, &len, buf);
 475
 476                 if (data == NULL)
 477                         return -EINVAL;
 478                 switch (type) {
 479                 case PN_PIPE_SB_CONNECT_REQ_PEP_SUB_TYPE:
 480                         if (len < 1)
 481                                 return -EINVAL;
 482                         peer_type = (peer_type & 0xff00) | data[0];
 483                         break;
 484                 }
 485                 n_sb--;
 486         }
 487
 488         skb = skb_clone(skb, GFP_ATOMIC);
 489         if (!skb)
 490                 return -ENOMEM;
 491
 492         /* Create a new to-be-accepted sock */
 493         newsk = sk_alloc(sock_net(sk), PF_PHONET, GFP_ATOMIC, sk->sk_prot);
 494         if (!newsk) {
 495                 kfree_skb(skb);
 496                 return -ENOMEM;
 497         }
 498         sock_init_data(NULL, newsk);
 499         newsk->sk_state = TCP_SYN_RECV;
 500         newsk->sk_backlog_rcv = pipe_do_rcv;
 501         newsk->sk_protocol = sk->sk_protocol;
 502         newsk->sk_destruct = pipe_destruct;
 503
 504         newpn = pep_sk(newsk);
 505         pn_skb_get_dst_sockaddr(skb, &dst);
 506         newpn->pn_sk.sobject = pn_sockaddr_get_object(&dst);
 507         newpn->pn_sk.resource = pn->pn_sk.resource;
 508         skb_queue_head_init(&newpn->ctrlreq_queue);
 509         newpn->pipe_handle = pipe_handle;
 510         atomic_set(&newpn->tx_credits, 0);
 511         newpn->peer_type = peer_type;
 512         newpn->rx_credits = 0;
 513         newpn->rx_fc = newpn->tx_fc = PN_LEGACY_FLOW_CONTROL;
 514         newpn->init_enable = enabled;
 515
 516         BUG_ON(!skb_queue_empty(&newsk->sk_receive_queue));
 517         skb_queue_head(&newsk->sk_receive_queue, skb);
 518         if (!sock_flag(sk, SOCK_DEAD))
 519                 sk->sk_data_ready(sk, 0);
 520
 521         sk_acceptq_added(sk);
 522         sk_add_node(newsk, &pn->ackq);
 523         return 0;
 524 }
 525
 526 /* Listening sock must be locked */
 527 static struct sock *pep_find_pipe(const struct hlist_head *hlist,
 528                                         const struct sockaddr_pn *dst,
 529                                         u8 pipe_handle)
 530 {
 531         struct hlist_node *node;
 532         struct sock *sknode;
 533         u16 dobj = pn_sockaddr_get_object(dst);
 534
 535         sk_for_each(sknode, node, hlist) {
 536                 struct pep_sock *pnnode = pep_sk(sknode);
 537
 538                 /* Ports match, but addresses might not: */
 539                 if (pnnode->pn_sk.sobject != dobj)
 540                         continue;
 541                 if (pnnode->pipe_handle != pipe_handle)
 542                         continue;
 543                 if (sknode->sk_state == TCP_CLOSE_WAIT)
 544                         continue;
 545
 546                 sock_hold(sknode);
 547                 return sknode;
 548         }
 549         return NULL;
 550 }
 551
 552 /*
 553  * Deliver an skb to a listening sock.
 554  * Socket lock must be held.
 555  * We then queue the skb to the right connected sock (if any).
 556  */
 557 static int pep_do_rcv(struct sock *sk, struct sk_buff *skb)
 558 {
 559         struct pep_sock *pn = pep_sk(sk);
 560         struct sock *sknode;
 561         struct pnpipehdr *hdr;
 562         struct sockaddr_pn dst;
 563         int err = NET_RX_SUCCESS;
 564         u8 pipe_handle;
 565
 566         if (!pskb_may_pull(skb, sizeof(*hdr)))
 567                 goto drop;
 568
 569         hdr = pnp_hdr(skb);
 570         pipe_handle = hdr->pipe_handle;
 571         if (pipe_handle == PN_PIPE_INVALID_HANDLE)
 572                 goto drop;
 573
 574         pn_skb_get_dst_sockaddr(skb, &dst);
 575
 576         /* Look for an existing pipe handle */
 577         sknode = pep_find_pipe(&pn->hlist, &dst, pipe_handle);
 578         if (sknode)
 579                 return sk_receive_skb(sknode, skb, 1);
 580
 581         /* Look for a pipe handle pending accept */
 582         sknode = pep_find_pipe(&pn->ackq, &dst, pipe_handle);
 583         if (sknode) {
 584                 sock_put(sknode);
 585                 if (net_ratelimit())
 586                         printk(KERN_WARNING"Phonet unconnected PEP ignored");
 587                 err = NET_RX_DROP;
 588                 goto drop;
 589         }
 590
 591         switch (hdr->message_id) {
 592         case PNS_PEP_CONNECT_REQ:
 593                 err = pep_connreq_rcv(sk, skb);
 594                 break;
 595
 596         case PNS_PEP_DISCONNECT_REQ:
 597                 pep_reply(sk, skb, PN_PIPE_NO_ERROR, NULL, 0, GFP_ATOMIC);
 598                 break;
 599
 600         case PNS_PEP_CTRL_REQ:
 601                 pep_ctrlreq_error(sk, skb, PN_PIPE_INVALID_HANDLE, GFP_ATOMIC);
 602                 break;
 603
 604         case PNS_PEP_RESET_REQ:
 605         case PNS_PEP_ENABLE_REQ:
 606         case PNS_PEP_DISABLE_REQ:
 607                 /* invalid handle is not even allowed here! */
 608         default:
 609                 err = NET_RX_DROP;
 610         }
 611 drop:
 612         kfree_skb(skb);
 613         return err;
 614 }
 615
 616 /* associated socket ceases to exist */
 617 static void pep_sock_close(struct sock *sk, long timeout)
 618 {
 619         struct pep_sock *pn = pep_sk(sk);
 620         int ifindex = 0;
 621
 622         sk_common_release(sk);
 623
 624         lock_sock(sk);
 625         if (sk->sk_state == TCP_LISTEN) {
 626                 /* Destroy the listen queue */
 627                 struct sock *sknode;
 628                 struct hlist_node *p, *n;
 629
 630                 sk_for_each_safe(sknode, p, n, &pn->ackq)
 631                         sk_del_node_init(sknode);
 632                 sk->sk_state = TCP_CLOSE;
 633         }
 634         ifindex = pn->ifindex;
 635         pn->ifindex = 0;
 636         release_sock(sk);
 637
 638         if (ifindex)
 639                 gprs_detach(sk);
 640 }
 641
 642 static int pep_wait_connreq(struct sock *sk, int noblock)
 643 {
 644         struct task_struct *tsk = current;
 645         struct pep_sock *pn = pep_sk(sk);
 646         long timeo = sock_rcvtimeo(sk, noblock);
 647
 648         for (;;) {
 649                 DEFINE_WAIT(wait);
 650
 651                 if (sk->sk_state != TCP_LISTEN)
 652                         return -EINVAL;
 653                 if (!hlist_empty(&pn->ackq))
 654                         break;
 655                 if (!timeo)
 656                         return -EWOULDBLOCK;
 657                 if (signal_pending(tsk))
 658                         return sock_intr_errno(timeo);
 659
 660                 prepare_to_wait_exclusive(&sk->sk_socket->wait, &wait,
 661                                                 TASK_INTERRUPTIBLE);
 662                 release_sock(sk);
 663                 timeo = schedule_timeout(timeo);
 664                 lock_sock(sk);
 665                 finish_wait(&sk->sk_socket->wait, &wait);
 666         }
 667
 668         return 0;
 669 }
 670
 671 static struct sock *pep_sock_accept(struct sock *sk, int flags, int *errp)
 672 {
 673         struct pep_sock *pn = pep_sk(sk);
 674         struct sock *newsk = NULL;
 675         struct sk_buff *oskb;
 676         int err;
 677
 678         lock_sock(sk);
 679         err = pep_wait_connreq(sk, flags & O_NONBLOCK);
 680         if (err)
 681                 goto out;
 682
 683         newsk = __sk_head(&pn->ackq);
 684
 685         oskb = skb_dequeue(&newsk->sk_receive_queue);
 686         err = pep_accept_conn(newsk, oskb);
 687         if (err) {
 688                 skb_queue_head(&newsk->sk_receive_queue, oskb);
 689                 newsk = NULL;
 690                 goto out;
 691         }
 692
 693         sock_hold(sk);
 694         pep_sk(newsk)->listener = sk;
 695
 696         sock_hold(newsk);
 697         sk_del_node_init(newsk);
 698         sk_acceptq_removed(sk);
 699         sk_add_node(newsk, &pn->hlist);
 700         __sock_put(newsk);
 701
 702 out:
 703         release_sock(sk);
 704         *errp = err;
 705         return newsk;
 706 }
 707
 708 static int pep_ioctl(struct sock *sk, int cmd, unsigned long arg)
 709 {
 710         struct pep_sock *pn = pep_sk(sk);
 711         int answ;
 712
 713         switch (cmd) {
 714         case SIOCINQ:
 715                 if (sk->sk_state == TCP_LISTEN)
 716                         return -EINVAL;
 717
 718                 lock_sock(sk);
 719                 if (sock_flag(sk, SOCK_URGINLINE)
 720                  && !skb_queue_empty(&pn->ctrlreq_queue))
 721                         answ = skb_peek(&pn->ctrlreq_queue)->len;
 722                 else if (!skb_queue_empty(&sk->sk_receive_queue))
 723                         answ = skb_peek(&sk->sk_receive_queue)->len;
 724                 else
 725                         answ = 0;
 726                 release_sock(sk);
 727                 return put_user(answ, (int __user *)arg);
 728         }
 729
 730         return -ENOIOCTLCMD;
 731 }
 732
 733 static int pep_init(struct sock *sk)
 734 {
 735         struct pep_sock *pn = pep_sk(sk);
 736
 737         INIT_HLIST_HEAD(&pn->ackq);
 738         INIT_HLIST_HEAD(&pn->hlist);
 739         skb_queue_head_init(&pn->ctrlreq_queue);
 740         pn->pipe_handle = PN_PIPE_INVALID_HANDLE;
 741         return 0;
 742 }
 743
 744 static int pep_setsockopt(struct sock *sk, int level, int optname,
 745                                 char __user *optval, unsigned int optlen)
 746 {
 747         struct pep_sock *pn = pep_sk(sk);
 748         int val = 0, err = 0;
 749
 750         if (level != SOL_PNPIPE)
 751                 return -ENOPROTOOPT;
 752         if (optlen >= sizeof(int)) {
 753                 if (get_user(val, (int __user *) optval))
 754                         return -EFAULT;
 755         }
 756
 757         lock_sock(sk);
 758         switch (optname) {
 759         case PNPIPE_ENCAP:
 760                 if (val && val != PNPIPE_ENCAP_IP) {
 761                         err = -EINVAL;
 762                         break;
 763                 }
 764                 if (!pn->ifindex == !val)
 765                         break; /* Nothing to do! */
 766                 if (!capable(CAP_NET_ADMIN)) {
 767                         err = -EPERM;
 768                         break;
 769                 }
 770                 if (val) {
 771                         release_sock(sk);
 772                         err = gprs_attach(sk);
 773                         if (err > 0) {
 774                                 pn->ifindex = err;
 775                                 err = 0;
 776                         }
 777                 } else {
 778                         pn->ifindex = 0;
 779                         release_sock(sk);
 780                         gprs_detach(sk);
 781                         err = 0;
 782                 }
 783                 goto out_norel;
 784         default:
 785                 err = -ENOPROTOOPT;
 786         }
 787         release_sock(sk);
 788
 789 out_norel:
 790         return err;
 791 }
 792
 793 static int pep_getsockopt(struct sock *sk, int level, int optname,
 794                                 char __user *optval, int __user *optlen)
 795 {
 796         struct pep_sock *pn = pep_sk(sk);
 797         int len, val;
 798
 799         if (level != SOL_PNPIPE)
 800                 return -ENOPROTOOPT;
 801         if (get_user(len, optlen))
 802                 return -EFAULT;
 803
 804         switch (optname) {
 805         case PNPIPE_ENCAP:
 806                 val = pn->ifindex ? PNPIPE_ENCAP_IP : PNPIPE_ENCAP_NONE;
 807                 break;
 808         case PNPIPE_IFINDEX:
 809                 val = pn->ifindex;
 810                 break;
 811         default:
 812                 return -ENOPROTOOPT;
 813         }
 814
 815         len = min_t(unsigned int, sizeof(int), len);
 816         if (put_user(len, optlen))
 817                 return -EFAULT;
 818         if (put_user(val, (int __user *) optval))
 819                 return -EFAULT;
 820         return 0;
 821 }
 822
 823 static int pipe_skb_send(struct sock *sk, struct sk_buff *skb)
 824 {
 825         struct pep_sock *pn = pep_sk(sk);
 826         struct pnpipehdr *ph;
 827
 828         if (pn_flow_safe(pn->tx_fc) &&
 829             !atomic_add_unless(&pn->tx_credits, -1, 0)) {
 830                 kfree_skb(skb);
 831                 return -ENOBUFS;
 832         }
 833
 834         skb_push(skb, 3);
 835         skb_reset_transport_header(skb);
 836         ph = pnp_hdr(skb);
 837         ph->utid = 0;
 838         ph->message_id = PNS_PIPE_DATA;
 839         ph->pipe_handle = pn->pipe_handle;
 840
 841         return pn_skb_send(sk, skb, &pipe_srv);
 842 }
 843
 844 static int pep_sendmsg(struct kiocb *iocb, struct sock *sk,
 845                         struct msghdr *msg, size_t len)
 846 {
 847         struct pep_sock *pn = pep_sk(sk);
 848         struct sk_buff *skb = NULL;
 849         long timeo;
 850         int flags = msg->msg_flags;
 851         int err, done;
 852
 853         if (msg->msg_flags & MSG_OOB || !(msg->msg_flags & MSG_EOR))
 854                 return -EOPNOTSUPP;
 855
 856         lock_sock(sk);
 857         timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT);
 858         if ((1 << sk->sk_state) & (TCPF_LISTEN|TCPF_CLOSE)) {
 859                 err = -ENOTCONN;
 860                 goto out;
 861         }
 862         if (sk->sk_state != TCP_ESTABLISHED) {
 863                 /* Wait until the pipe gets to enabled state */
 864 disabled:
 865                 err = sk_stream_wait_connect(sk, &timeo);
 866                 if (err)
 867                         goto out;
 868
 869                 if (sk->sk_state == TCP_CLOSE_WAIT) {
 870                         err = -ECONNRESET;
 871                         goto out;
 872                 }
 873         }
 874         BUG_ON(sk->sk_state != TCP_ESTABLISHED);
 875
 876         /* Wait until flow control allows TX */
 877         done = atomic_read(&pn->tx_credits);
 878         while (!done) {
 879                 DEFINE_WAIT(wait);
 880
 881                 if (!timeo) {
 882                         err = -EAGAIN;
 883                         goto out;
 884                 }
 885                 if (signal_pending(current)) {
 886                         err = sock_intr_errno(timeo);
 887                         goto out;
 888                 }
 889
 890                 prepare_to_wait(&sk->sk_socket->wait, &wait,
 891                                 TASK_INTERRUPTIBLE);
 892                 done = sk_wait_event(sk, &timeo, atomic_read(&pn->tx_credits));
 893                 finish_wait(&sk->sk_socket->wait, &wait);
 894
 895                 if (sk->sk_state != TCP_ESTABLISHED)
 896                         goto disabled;
 897         }
 898
 899         if (!skb) {
 900                 skb = sock_alloc_send_skb(sk, MAX_PNPIPE_HEADER + len,
 901                                                 flags & MSG_DONTWAIT, &err);
 902                 if (skb == NULL)
 903                         goto out;
 904                 skb_reserve(skb, MAX_PHONET_HEADER + 3);
 905
 906                 if (sk->sk_state != TCP_ESTABLISHED ||
 907                     !atomic_read(&pn->tx_credits))
 908                         goto disabled; /* sock_alloc_send_skb might sleep */
 909         }
 910
 911         err = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len);
 912         if (err < 0)
 913                 goto out;
 914
 915         err = pipe_skb_send(sk, skb);
 916         if (err >= 0)
 917                 err = len; /* success! */
 918         skb = NULL;
 919 out:
 920         release_sock(sk);
 921         kfree_skb(skb);
 922         return err;
 923 }
 924
 925 int pep_writeable(struct sock *sk)
 926 {
 927         struct pep_sock *pn = pep_sk(sk);
 928
 929         return atomic_read(&pn->tx_credits);
 930 }
 931
 932 int pep_write(struct sock *sk, struct sk_buff *skb)
 933 {
 934         struct sk_buff *rskb, *fs;
 935         int flen = 0;
 936
 937         rskb = alloc_skb(MAX_PNPIPE_HEADER, GFP_ATOMIC);
 938         if (!rskb) {
 939                 kfree_skb(skb);
 940                 return -ENOMEM;
 941         }
 942         skb_shinfo(rskb)->frag_list = skb;
 943         rskb->len += skb->len;
 944         rskb->data_len += rskb->len;
 945         rskb->truesize += rskb->len;
 946
 947         /* Avoid nested fragments */
 948         skb_walk_frags(skb, fs)
 949                 flen += fs->len;
 950         skb->next = skb_shinfo(skb)->frag_list;
 951         skb_frag_list_init(skb);
 952         skb->len -= flen;
 953         skb->data_len -= flen;
 954         skb->truesize -= flen;
 955
 956         skb_reserve(rskb, MAX_PHONET_HEADER + 3);
 957         return pipe_skb_send(sk, rskb);
 958 }
 959
 960 struct sk_buff *pep_read(struct sock *sk)
 961 {
 962         struct sk_buff *skb = skb_dequeue(&sk->sk_receive_queue);
 963
 964         if (sk->sk_state == TCP_ESTABLISHED)
 965                 pipe_grant_credits(sk);
 966         return skb;
 967 }
 968
 969 static int pep_recvmsg(struct kiocb *iocb, struct sock *sk,
 970                         struct msghdr *msg, size_t len, int noblock,
 971                         int flags, int *addr_len)
 972 {
 973         struct sk_buff *skb;
 974         int err;
 975
 976         if (unlikely(1 << sk->sk_state & (TCPF_LISTEN | TCPF_CLOSE)))
 977                 return -ENOTCONN;
 978
 979         if ((flags & MSG_OOB) || sock_flag(sk, SOCK_URGINLINE)) {
 980                 /* Dequeue and acknowledge control request */
 981                 struct pep_sock *pn = pep_sk(sk);
 982
 983                 skb = skb_dequeue(&pn->ctrlreq_queue);
 984                 if (skb) {
 985                         pep_ctrlreq_error(sk, skb, PN_PIPE_NO_ERROR,
 986                                                 GFP_KERNEL);
 987                         msg->msg_flags |= MSG_OOB;
 988                         goto copy;
 989                 }
 990                 if (flags & MSG_OOB)
 991                         return -EINVAL;
 992         }
 993
 994         skb = skb_recv_datagram(sk, flags, noblock, &err);
 995         lock_sock(sk);
 996         if (skb == NULL) {
 997                 if (err == -ENOTCONN && sk->sk_state == TCP_CLOSE_WAIT)
 998                         err = -ECONNRESET;
 999                 release_sock(sk);
1000                 return err;
1001         }
1002
1003         if (sk->sk_state == TCP_ESTABLISHED)
1004                 pipe_grant_credits(sk);
1005         release_sock(sk);
1006 copy:
1007         msg->msg_flags |= MSG_EOR;
1008         if (skb->len > len)
1009                 msg->msg_flags |= MSG_TRUNC;
1010         else
1011                 len = skb->len;
1012
1013         err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, len);
1014         if (!err)
1015                 err = (flags & MSG_TRUNC) ? skb->len : len;
1016
1017         skb_free_datagram(sk, skb);
1018         return err;
1019 }
1020
1021 static void pep_sock_unhash(struct sock *sk)
1022 {
1023         struct pep_sock *pn = pep_sk(sk);
1024         struct sock *skparent = NULL;
1025
1026         lock_sock(sk);
1027         if ((1 << sk->sk_state) & ~(TCPF_CLOSE|TCPF_LISTEN)) {
1028                 skparent = pn->listener;
1029                 sk_del_node_init(sk);
1030                 release_sock(sk);
1031
1032                 sk = skparent;
1033                 pn = pep_sk(skparent);
1034                 lock_sock(sk);
1035         }
1036         /* Unhash a listening sock only when it is closed
1037          * and all of its active connected pipes are closed. */
1038         if (hlist_empty(&pn->hlist))
1039                 pn_sock_unhash(&pn->pn_sk.sk);
1040         release_sock(sk);
1041
1042         if (skparent)
1043                 sock_put(skparent);
1044 }
1045
1046 static struct proto pep_proto = {
1047         .close          = pep_sock_close,
1048         .accept         = pep_sock_accept,
1049         .ioctl          = pep_ioctl,
1050         .init           = pep_init,
1051         .setsockopt     = pep_setsockopt,
1052         .getsockopt     = pep_getsockopt,
1053         .sendmsg        = pep_sendmsg,
1054         .recvmsg        = pep_recvmsg,
1055         .backlog_rcv    = pep_do_rcv,
1056         .hash           = pn_sock_hash,
1057         .unhash         = pep_sock_unhash,
1058         .get_port       = pn_sock_get_port,
1059         .obj_size       = sizeof(struct pep_sock),
1060         .owner          = THIS_MODULE,
1061         .name           = "PNPIPE",
1062 };
1063
1064 static struct phonet_protocol pep_pn_proto = {
1065         .ops            = &phonet_stream_ops,
1066         .prot           = &pep_proto,
1067         .sock_type      = SOCK_SEQPACKET,
1068 };
1069
1070 static int __init pep_register(void)
1071 {
1072         return phonet_proto_register(PN_PROTO_PIPE, &pep_pn_proto);
1073 }
1074
1075 static void __exit pep_unregister(void)
1076 {
1077         phonet_proto_unregister(PN_PROTO_PIPE, &pep_pn_proto);
1078 }
1079
1080 module_init(pep_register);
1081 module_exit(pep_unregister);
1082 MODULE_AUTHOR("Remi Denis-Courmont, Nokia");
1083 MODULE_DESCRIPTION("Phonet pipe protocol");
1084 MODULE_LICENSE("GPL");
1085 MODULE_ALIAS_NET_PF_PROTO(PF_PHONET, PN_PROTO_PIPE);